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freebsd-dev/sys/netinet/tcp_stacks/rack.c
Randall Stewart 95ef69c63c iSo in doing final checks on OCA firmware with all the latest tweaks the dup-ack checking 
packet drill script was failing with a number of unexpected acks. So it turns
out if you have the default recvwin set up to 1Meg (like OCA's do) and you
have no window scaling (like the dupack checking code) then we have another
case where we are always trying to update the rwnd and sending an
ack when we should not.

Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D25298
2020-06-16 18:16:45 +00:00

15147 lines
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/*-
* Copyright (c) 2016-2020 Netflix, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
#include "opt_ratelimit.h"
#include "opt_kern_tls.h"
#include <sys/param.h>
#include <sys/arb.h>
#include <sys/module.h>
#include <sys/kernel.h>
#ifdef TCP_HHOOK
#include <sys/hhook.h>
#endif
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/mbuf.h>
#include <sys/proc.h> /* for proc0 declaration */
#include <sys/socket.h>
#include <sys/socketvar.h>
#ifdef KERN_TLS
#include <sys/ktls.h>
#endif
#include <sys/sysctl.h>
#include <sys/systm.h>
#ifdef STATS
#include <sys/qmath.h>
#include <sys/tree.h>
#include <sys/stats.h> /* Must come after qmath.h and tree.h */
#else
#include <sys/tree.h>
#endif
#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/tim_filter.h>
#include <sys/smp.h>
#include <sys/kthread.h>
#include <sys/kern_prefetch.h>
#include <sys/protosw.h>
#include <vm/uma.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/vnet.h>
#define TCPSTATES /* for logging */
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_pcb.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h> /* required for icmp_var.h */
#include <netinet/icmp_var.h> /* for ICMP_BANDLIM */
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet/tcp.h>
#define TCPOUTFLAGS
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_log_buf.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_hpts.h>
#include <netinet/tcp_ratelimit.h>
#include <netinet/tcpip.h>
#include <netinet/cc/cc.h>
#include <netinet/tcp_fastopen.h>
#include <netinet/tcp_lro.h>
#ifdef NETFLIX_SHARED_CWND
#include <netinet/tcp_shared_cwnd.h>
#endif
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif /* TCPDEBUG */
#ifdef TCP_OFFLOAD
#include <netinet/tcp_offload.h>
#endif
#ifdef INET6
#include <netinet6/tcp6_var.h>
#endif
#include <netipsec/ipsec_support.h>
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#endif /* IPSEC */
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <machine/in_cksum.h>
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
#include "sack_filter.h"
#include "tcp_rack.h"
#include "rack_bbr_common.h"
uma_zone_t rack_zone;
uma_zone_t rack_pcb_zone;
#ifndef TICKS2SBT
#define TICKS2SBT(__t) (tick_sbt * ((sbintime_t)(__t)))
#endif
struct sysctl_ctx_list rack_sysctl_ctx;
struct sysctl_oid *rack_sysctl_root;
#define CUM_ACKED 1
#define SACKED 2
/*
* The RACK module incorporates a number of
* TCP ideas that have been put out into the IETF
* over the last few years:
* - Matt Mathis's Rate Halving which slowly drops
* the congestion window so that the ack clock can
* be maintained during a recovery.
* - Yuchung Cheng's RACK TCP (for which its named) that
* will stop us using the number of dup acks and instead
* use time as the gage of when we retransmit.
* - Reorder Detection of RFC4737 and the Tail-Loss probe draft
* of Dukkipati et.al.
* RACK depends on SACK, so if an endpoint arrives that
* cannot do SACK the state machine below will shuttle the
* connection back to using the "default" TCP stack that is
* in FreeBSD.
*
* To implement RACK the original TCP stack was first decomposed
* into a functional state machine with individual states
* for each of the possible TCP connection states. The do_segement
* functions role in life is to mandate the connection supports SACK
* initially and then assure that the RACK state matches the conenction
* state before calling the states do_segment function. Each
* state is simplified due to the fact that the original do_segment
* has been decomposed and we *know* what state we are in (no
* switches on the state) and all tests for SACK are gone. This
* greatly simplifies what each state does.
*
* TCP output is also over-written with a new version since it
* must maintain the new rack scoreboard.
*
*/
static int32_t rack_tlp_thresh = 1;
static int32_t rack_tlp_limit = 2; /* No more than 2 TLPs w-out new data */
static int32_t rack_tlp_use_greater = 1;
static int32_t rack_reorder_thresh = 2;
static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000
* - 60 seconds */
/* Attack threshold detections */
static uint32_t rack_highest_sack_thresh_seen = 0;
static uint32_t rack_highest_move_thresh_seen = 0;
static int32_t rack_pkt_delay = 1;
static int32_t rack_early_recovery = 1;
static int32_t rack_send_a_lot_in_prr = 1;
static int32_t rack_min_to = 1; /* Number of ms minimum timeout */
static int32_t rack_verbose_logging = 0;
static int32_t rack_ignore_data_after_close = 1;
static int32_t rack_enable_shared_cwnd = 0;
static int32_t rack_limits_scwnd = 1;
static int32_t rack_enable_mqueue_for_nonpaced = 0;
static int32_t rack_disable_prr = 0;
static int32_t use_rack_rr = 1;
static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
static int32_t rack_persist_min = 250; /* 250ms */
static int32_t rack_persist_max = 2000; /* 2 Second */
static int32_t rack_sack_not_required = 0; /* set to one to allow non-sack to use rack */
static int32_t rack_hw_tls_max_seg = 3; /* 3 means use hw-tls single segment */
static int32_t rack_default_init_window = 0; /* Use system default */
static int32_t rack_limit_time_with_srtt = 0;
static int32_t rack_hw_pace_adjust = 0;
/*
* Currently regular tcp has a rto_min of 30ms
* the backoff goes 12 times so that ends up
* being a total of 122.850 seconds before a
* connection is killed.
*/
static uint32_t rack_def_data_window = 20;
static uint32_t rack_goal_bdp = 2;
static uint32_t rack_min_srtts = 1;
static uint32_t rack_min_measure_usec = 0;
static int32_t rack_tlp_min = 10;
static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */
static int32_t rack_rto_max = 4000; /* 4 seconds */
static const int32_t rack_free_cache = 2;
static int32_t rack_hptsi_segments = 40;
static int32_t rack_rate_sample_method = USE_RTT_LOW;
static int32_t rack_pace_every_seg = 0;
static int32_t rack_delayed_ack_time = 200; /* 200ms */
static int32_t rack_slot_reduction = 4;
static int32_t rack_wma_divisor = 8; /* For WMA calculation */
static int32_t rack_cwnd_block_ends_measure = 0;
static int32_t rack_rwnd_block_ends_measure = 0;
static int32_t rack_lower_cwnd_at_tlp = 0;
static int32_t rack_use_proportional_reduce = 0;
static int32_t rack_proportional_rate = 10;
static int32_t rack_tlp_max_resend = 2;
static int32_t rack_limited_retran = 0;
static int32_t rack_always_send_oldest = 0;
static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
static uint16_t rack_per_of_gp_ss = 250; /* 250 % slow-start */
static uint16_t rack_per_of_gp_ca = 200; /* 200 % congestion-avoidance */
static uint16_t rack_per_of_gp_rec = 200; /* 200 % of bw */
/* Probertt */
static uint16_t rack_per_of_gp_probertt = 60; /* 60% of bw */
static uint16_t rack_per_of_gp_lowthresh = 40; /* 40% is bottom */
static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
static uint16_t rack_atexit_prtt_hbp = 130; /* Clamp to 130% on exit prtt if highly buffered path */
static uint16_t rack_atexit_prtt = 130; /* Clamp to 100% on exit prtt if non highly buffered path */
static uint32_t rack_max_drain_wait = 2; /* How man gp srtt's before we give up draining */
static uint32_t rack_must_drain = 1; /* How many GP srtt's we *must* wait */
static uint32_t rack_probertt_use_min_rtt_entry = 1; /* Use the min to calculate the goal else gp_srtt */
static uint32_t rack_probertt_use_min_rtt_exit = 0;
static uint32_t rack_probe_rtt_sets_cwnd = 0;
static uint32_t rack_probe_rtt_safety_val = 2000000; /* No more than 2 sec in probe-rtt */
static uint32_t rack_time_between_probertt = 9600000; /* 9.6 sec in us */
static uint32_t rack_probertt_gpsrtt_cnt_mul = 0; /* How many srtt periods does probe-rtt last top fraction */
static uint32_t rack_probertt_gpsrtt_cnt_div = 0; /* How many srtt periods does probe-rtt last bottom fraction */
static uint32_t rack_min_probertt_hold = 200000; /* Equal to delayed ack time */
static uint32_t rack_probertt_filter_life = 10000000;
static uint32_t rack_probertt_lower_within = 10;
static uint32_t rack_min_rtt_movement = 250; /* Must move at least 250 useconds to count as a lowering */
static int32_t rack_pace_one_seg = 0; /* Shall we pace for less than 1.4Meg 1MSS at a time */
static int32_t rack_probertt_clear_is = 1;
static int32_t rack_max_drain_hbp = 1; /* Extra drain times gpsrtt for highly buffered paths */
static int32_t rack_hbp_thresh = 3; /* what is the divisor max_rtt/min_rtt to decided a hbp */
/* Part of pacing */
static int32_t rack_max_per_above = 30; /* When we go to increment stop if above 100+this% */
/* Timely information */
/* Combine these two gives the range of 'no change' to bw */
/* ie the up/down provide the upper and lower bound */
static int32_t rack_gp_per_bw_mul_up = 2; /* 2% */
static int32_t rack_gp_per_bw_mul_down = 4; /* 4% */
static int32_t rack_gp_rtt_maxmul = 3; /* 3 x maxmin */
static int32_t rack_gp_rtt_minmul = 1; /* minrtt + (minrtt/mindiv) is lower rtt */
static int32_t rack_gp_rtt_mindiv = 4; /* minrtt + (minrtt * minmul/mindiv) is lower rtt */
static int32_t rack_gp_decrease_per = 20; /* 20% decrease in multipler */
static int32_t rack_gp_increase_per = 2; /* 2% increase in multipler */
static int32_t rack_per_lower_bound = 50; /* Don't allow to drop below this multiplier */
static int32_t rack_per_upper_bound_ss = 0; /* Don't allow SS to grow above this */
static int32_t rack_per_upper_bound_ca = 0; /* Don't allow CA to grow above this */
static int32_t rack_do_dyn_mul = 0; /* Are the rack gp multipliers dynamic */
static int32_t rack_gp_no_rec_chg = 1; /* Prohibit recovery from reducing it's multiplier */
static int32_t rack_timely_dec_clear = 6; /* Do we clear decrement count at a value (6)? */
static int32_t rack_timely_max_push_rise = 3; /* One round of pushing */
static int32_t rack_timely_max_push_drop = 3; /* Three round of pushing */
static int32_t rack_timely_min_segs = 4; /* 4 segment minimum */
static int32_t rack_use_max_for_nobackoff = 0;
static int32_t rack_timely_int_timely_only = 0; /* do interim timely's only use the timely algo (no b/w changes)? */
static int32_t rack_timely_no_stopping = 0;
static int32_t rack_down_raise_thresh = 100;
static int32_t rack_req_segs = 1;
/* Weird delayed ack mode */
static int32_t rack_use_imac_dack = 0;
/* Rack specific counters */
counter_u64_t rack_badfr;
counter_u64_t rack_badfr_bytes;
counter_u64_t rack_rtm_prr_retran;
counter_u64_t rack_rtm_prr_newdata;
counter_u64_t rack_timestamp_mismatch;
counter_u64_t rack_reorder_seen;
counter_u64_t rack_paced_segments;
counter_u64_t rack_unpaced_segments;
counter_u64_t rack_calc_zero;
counter_u64_t rack_calc_nonzero;
counter_u64_t rack_saw_enobuf;
counter_u64_t rack_saw_enetunreach;
counter_u64_t rack_per_timer_hole;
/* Tail loss probe counters */
counter_u64_t rack_tlp_tot;
counter_u64_t rack_tlp_newdata;
counter_u64_t rack_tlp_retran;
counter_u64_t rack_tlp_retran_bytes;
counter_u64_t rack_tlp_retran_fail;
counter_u64_t rack_to_tot;
counter_u64_t rack_to_arm_rack;
counter_u64_t rack_to_arm_tlp;
counter_u64_t rack_to_alloc;
counter_u64_t rack_to_alloc_hard;
counter_u64_t rack_to_alloc_emerg;
counter_u64_t rack_to_alloc_limited;
counter_u64_t rack_alloc_limited_conns;
counter_u64_t rack_split_limited;
counter_u64_t rack_sack_proc_all;
counter_u64_t rack_sack_proc_short;
counter_u64_t rack_sack_proc_restart;
counter_u64_t rack_sack_attacks_detected;
counter_u64_t rack_sack_attacks_reversed;
counter_u64_t rack_sack_used_next_merge;
counter_u64_t rack_sack_splits;
counter_u64_t rack_sack_used_prev_merge;
counter_u64_t rack_sack_skipped_acked;
counter_u64_t rack_ack_total;
counter_u64_t rack_express_sack;
counter_u64_t rack_sack_total;
counter_u64_t rack_move_none;
counter_u64_t rack_move_some;
counter_u64_t rack_used_tlpmethod;
counter_u64_t rack_used_tlpmethod2;
counter_u64_t rack_enter_tlp_calc;
counter_u64_t rack_input_idle_reduces;
counter_u64_t rack_collapsed_win;
counter_u64_t rack_tlp_does_nada;
counter_u64_t rack_try_scwnd;
/* Counters for HW TLS */
counter_u64_t rack_tls_rwnd;
counter_u64_t rack_tls_cwnd;
counter_u64_t rack_tls_app;
counter_u64_t rack_tls_other;
counter_u64_t rack_tls_filled;
counter_u64_t rack_tls_rxt;
counter_u64_t rack_tls_tlp;
/* Temp CPU counters */
counter_u64_t rack_find_high;
counter_u64_t rack_progress_drops;
counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
static void
rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line);
static int
rack_process_ack(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to,
uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
static int
rack_process_data(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
static void
rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
struct tcphdr *th, uint16_t nsegs, uint16_t type, int32_t recovery);
static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
uint8_t limit_type);
static struct rack_sendmap *
rack_check_recovery_mode(struct tcpcb *tp,
uint32_t tsused);
static void
rack_cong_signal(struct tcpcb *tp, struct tcphdr *th,
uint32_t type);
static void rack_counter_destroy(void);
static int
rack_ctloutput(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp);
static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
static void
rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line);
static void
rack_do_segment(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint8_t iptos);
static void rack_dtor(void *mem, int32_t size, void *arg);
static void
rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
uint32_t t, uint32_t cts);
static void
rack_log_alt_to_to_cancel(struct tcp_rack *rack,
uint32_t flex1, uint32_t flex2,
uint32_t flex3, uint32_t flex4,
uint32_t flex5, uint32_t flex6,
uint16_t flex7, uint8_t mod);
static void
rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line, struct rack_sendmap *rsm);
static struct rack_sendmap *
rack_find_high_nonack(struct tcp_rack *rack,
struct rack_sendmap *rsm);
static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
static int
rack_get_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
static void
rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq th_ack, int line);
static uint32_t
rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
static int32_t rack_handoff_ok(struct tcpcb *tp);
static int32_t rack_init(struct tcpcb *tp);
static void rack_init_sysctls(void);
static void
rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
struct tcphdr *th);
static void
rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
uint8_t pass, struct rack_sendmap *hintrsm, uint32_t us_cts);
static void
rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm);
static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
static int32_t rack_output(struct tcpcb *tp);
static uint32_t
rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
uint32_t cts, int *moved_two);
static void rack_post_recovery(struct tcpcb *tp, struct tcphdr *th);
static void rack_remxt_tmr(struct tcpcb *tp);
static int
rack_set_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
static int32_t rack_stopall(struct tcpcb *tp);
static void
rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
uint32_t delta);
static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
static uint32_t
rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp);
static void
rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts);
static int
rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
static int
rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_closing(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_established(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_lastack(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
struct rack_sendmap *
tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
uint32_t tsused);
static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
static void
tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th);
int32_t rack_clear_counter=0;
static int
sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
{
uint32_t stat;
int32_t error;
error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
if (error || req->newptr == NULL)
return error;
error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
if (error)
return (error);
if (stat == 1) {
#ifdef INVARIANTS
printf("Clearing RACK counters\n");
#endif
counter_u64_zero(rack_badfr);
counter_u64_zero(rack_badfr_bytes);
counter_u64_zero(rack_rtm_prr_retran);
counter_u64_zero(rack_rtm_prr_newdata);
counter_u64_zero(rack_timestamp_mismatch);
counter_u64_zero(rack_reorder_seen);
counter_u64_zero(rack_tlp_tot);
counter_u64_zero(rack_tlp_newdata);
counter_u64_zero(rack_tlp_retran);
counter_u64_zero(rack_tlp_retran_bytes);
counter_u64_zero(rack_tlp_retran_fail);
counter_u64_zero(rack_to_tot);
counter_u64_zero(rack_to_arm_rack);
counter_u64_zero(rack_to_arm_tlp);
counter_u64_zero(rack_paced_segments);
counter_u64_zero(rack_calc_zero);
counter_u64_zero(rack_calc_nonzero);
counter_u64_zero(rack_unpaced_segments);
counter_u64_zero(rack_saw_enobuf);
counter_u64_zero(rack_saw_enetunreach);
counter_u64_zero(rack_per_timer_hole);
counter_u64_zero(rack_to_alloc_hard);
counter_u64_zero(rack_to_alloc_emerg);
counter_u64_zero(rack_sack_proc_all);
counter_u64_zero(rack_sack_proc_short);
counter_u64_zero(rack_sack_proc_restart);
counter_u64_zero(rack_to_alloc);
counter_u64_zero(rack_to_alloc_limited);
counter_u64_zero(rack_alloc_limited_conns);
counter_u64_zero(rack_split_limited);
counter_u64_zero(rack_find_high);
counter_u64_zero(rack_tls_rwnd);
counter_u64_zero(rack_tls_cwnd);
counter_u64_zero(rack_tls_app);
counter_u64_zero(rack_tls_other);
counter_u64_zero(rack_tls_filled);
counter_u64_zero(rack_tls_rxt);
counter_u64_zero(rack_tls_tlp);
counter_u64_zero(rack_sack_attacks_detected);
counter_u64_zero(rack_sack_attacks_reversed);
counter_u64_zero(rack_sack_used_next_merge);
counter_u64_zero(rack_sack_used_prev_merge);
counter_u64_zero(rack_sack_splits);
counter_u64_zero(rack_sack_skipped_acked);
counter_u64_zero(rack_ack_total);
counter_u64_zero(rack_express_sack);
counter_u64_zero(rack_sack_total);
counter_u64_zero(rack_move_none);
counter_u64_zero(rack_move_some);
counter_u64_zero(rack_used_tlpmethod);
counter_u64_zero(rack_used_tlpmethod2);
counter_u64_zero(rack_enter_tlp_calc);
counter_u64_zero(rack_progress_drops);
counter_u64_zero(rack_tlp_does_nada);
counter_u64_zero(rack_try_scwnd);
counter_u64_zero(rack_collapsed_win);
}
rack_clear_counter = 0;
return (0);
}
static void
rack_init_sysctls(void)
{
struct sysctl_oid *rack_counters;
struct sysctl_oid *rack_attack;
struct sysctl_oid *rack_pacing;
struct sysctl_oid *rack_timely;
struct sysctl_oid *rack_timers;
struct sysctl_oid *rack_tlp;
struct sysctl_oid *rack_misc;
struct sysctl_oid *rack_measure;
struct sysctl_oid *rack_probertt;
rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"sack_attack",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Sack Attack Counters and Controls");
rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"stats",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Counters");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "rate_sample_method", CTLFLAG_RW,
&rack_rate_sample_method , USE_RTT_LOW,
"What method should we use for rate sampling 0=high, 1=low ");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "hw_tlsmax", CTLFLAG_RW,
&rack_hw_tls_max_seg , 3,
"What is the maximum number of full TLS records that will be sent at once");
/* Probe rtt related controls */
rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"probertt",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"ProbeRTT related Controls");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
&rack_atexit_prtt_hbp, 130,
"What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
&rack_atexit_prtt, 130,
"What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_mul", CTLFLAG_RW,
&rack_per_of_gp_probertt, 60,
"What percentage of goodput do we pace at in probertt");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
&rack_per_of_gp_probertt_reduce, 10,
"What percentage of goodput do we reduce every gp_srtt");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_low", CTLFLAG_RW,
&rack_per_of_gp_lowthresh, 40,
"What percentage of goodput do we allow the multiplier to fall to");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "time_between", CTLFLAG_RW,
& rack_time_between_probertt, 96000000,
"How many useconds between the lowest rtt falling must past before we enter probertt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "safety", CTLFLAG_RW,
&rack_probe_rtt_safety_val, 2000000,
"If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "sets_cwnd", CTLFLAG_RW,
&rack_probe_rtt_sets_cwnd, 0,
"Do we set the cwnd too (if always_lower is on)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
&rack_max_drain_wait, 2,
"Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
&rack_must_drain, 1,
"We must drain this many gp_srtt's waiting for flight to reach goal");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
&rack_probertt_use_min_rtt_entry, 1,
"Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
&rack_probertt_use_min_rtt_exit, 0,
"How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "length_div", CTLFLAG_RW,
&rack_probertt_gpsrtt_cnt_div, 0,
"How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "length_mul", CTLFLAG_RW,
&rack_probertt_gpsrtt_cnt_mul, 0,
"How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
&rack_min_probertt_hold, 200000,
"What is the minimum time we hold probertt at target");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "filter_life", CTLFLAG_RW,
&rack_probertt_filter_life, 10000000,
"What is the time for the filters life in useconds");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "lower_within", CTLFLAG_RW,
&rack_probertt_lower_within, 10,
"If the rtt goes lower within this percentage of the time, go into probe-rtt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "must_move", CTLFLAG_RW,
&rack_min_rtt_movement, 250,
"How much is the minimum movement in rtt to count as a drop for probertt purposes");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
&rack_probertt_clear_is, 1,
"Do we clear I/S counts on exiting probe-rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
&rack_max_drain_hbp, 1,
"How many extra drain gpsrtt's do we get in highly buffered paths");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "hbp_threshold", CTLFLAG_RW,
&rack_hbp_thresh, 3,
"We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
/* Pacing related sysctls */
rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"pacing",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Pacing related Controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "max_pace_over", CTLFLAG_RW,
&rack_max_per_above, 30,
"What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "pace_to_one", CTLFLAG_RW,
&rack_pace_one_seg, 0,
"Do we allow low b/w pacing of 1MSS instead of two");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
&rack_limit_time_with_srtt, 0,
"Do we limit pacing time based on srtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "init_win", CTLFLAG_RW,
&rack_default_init_window, 0,
"Do we have a rack initial window 0 = system default");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "hw_pacing_adjust", CTLFLAG_RW,
&rack_hw_pace_adjust, 0,
"What percentage do we raise the MSS by (11 = 1.1%)");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_ss", CTLFLAG_RW,
&rack_per_of_gp_ss, 250,
"If non zero, what percentage of goodput to pace at in slow start");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_ca", CTLFLAG_RW,
&rack_per_of_gp_ca, 150,
"If non zero, what percentage of goodput to pace at in congestion avoidance");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_rec", CTLFLAG_RW,
&rack_per_of_gp_rec, 200,
"If non zero, what percentage of goodput to pace at in recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "pace_max_seg", CTLFLAG_RW,
&rack_hptsi_segments, 40,
"What size is the max for TSO segments in pacing and burst mitigation");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "burst_reduces", CTLFLAG_RW,
&rack_slot_reduction, 4,
"When doing only burst mitigation what is the reduce divisor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "use_pacing", CTLFLAG_RW,
&rack_pace_every_seg, 0,
"If set we use pacing, if clear we use only the original burst mitigation");
rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"timely",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Timely RTT Controls");
/* Timely based GP dynmics */
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upper", CTLFLAG_RW,
&rack_gp_per_bw_mul_up, 2,
"Rack timely upper range for equal b/w (in percentage)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "lower", CTLFLAG_RW,
&rack_gp_per_bw_mul_down, 4,
"Rack timely lower range for equal b/w (in percentage)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
&rack_gp_rtt_maxmul, 3,
"Rack timely multipler of lowest rtt for rtt_max");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_min_div", CTLFLAG_RW,
&rack_gp_rtt_mindiv, 4,
"Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
&rack_gp_rtt_minmul, 1,
"Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "decrease", CTLFLAG_RW,
&rack_gp_decrease_per, 20,
"Rack timely decrease percentage of our GP multiplication factor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "increase", CTLFLAG_RW,
&rack_gp_increase_per, 2,
"Rack timely increase perentage of our GP multiplication factor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "lowerbound", CTLFLAG_RW,
&rack_per_lower_bound, 50,
"Rack timely lowest percentage we allow GP multiplier to fall to");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upperboundss", CTLFLAG_RW,
&rack_per_upper_bound_ss, 0,
"Rack timely higest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upperboundca", CTLFLAG_RW,
&rack_per_upper_bound_ca, 0,
"Rack timely higest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "dynamicgp", CTLFLAG_RW,
&rack_do_dyn_mul, 0,
"Rack timely do we enable dynmaic timely goodput by default");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "no_rec_red", CTLFLAG_RW,
&rack_gp_no_rec_chg, 1,
"Rack timely do we prohibit the recovery multiplier from being lowered");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
&rack_timely_dec_clear, 6,
"Rack timely what threshold do we count to before another boost during b/w decent");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "max_push_rise", CTLFLAG_RW,
&rack_timely_max_push_rise, 3,
"Rack timely how many times do we push up with b/w increase");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "max_push_drop", CTLFLAG_RW,
&rack_timely_max_push_drop, 3,
"Rack timely how many times do we push back on b/w decent");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "min_segs", CTLFLAG_RW,
&rack_timely_min_segs, 4,
"Rack timely when setting the cwnd what is the min num segments");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "noback_max", CTLFLAG_RW,
&rack_use_max_for_nobackoff, 0,
"Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "interim_timely_only", CTLFLAG_RW,
&rack_timely_int_timely_only, 0,
"Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "nonstop", CTLFLAG_RW,
&rack_timely_no_stopping, 0,
"Rack timely don't stop increase");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
&rack_down_raise_thresh, 100,
"If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
&rack_req_segs, 1,
"Bottom dragging if not these many segments outstanding and room");
/* TLP and Rack related parameters */
rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"tlp",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TLP and Rack related Controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "use_rrr", CTLFLAG_RW,
&use_rack_rr, 1,
"Do we use Rack Rapid Recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
&rack_non_rxt_use_cr, 0,
"Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlpmethod", CTLFLAG_RW,
&rack_tlp_threshold_use, TLP_USE_TWO_ONE,
"What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "limit", CTLFLAG_RW,
&rack_tlp_limit, 2,
"How many TLP's can be sent without sending new data");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "use_greater", CTLFLAG_RW,
&rack_tlp_use_greater, 1,
"Should we use the rack_rtt time if its greater than srtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlpminto", CTLFLAG_RW,
&rack_tlp_min, 10,
"TLP minimum timeout per the specification (10ms)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "send_oldest", CTLFLAG_RW,
&rack_always_send_oldest, 0,
"Should we always send the oldest TLP and RACK-TLP");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "rack_tlimit", CTLFLAG_RW,
&rack_limited_retran, 0,
"How many times can a rack timeout drive out sends");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlp_retry", CTLFLAG_RW,
&rack_tlp_max_resend, 2,
"How many times does TLP retry a single segment or multiple with no ACK");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
&rack_lower_cwnd_at_tlp, 0,
"When a TLP completes a retran should we enter recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "reorder_thresh", CTLFLAG_RW,
&rack_reorder_thresh, 2,
"What factor for rack will be added when seeing reordering (shift right)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
&rack_tlp_thresh, 1,
"What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "reorder_fade", CTLFLAG_RW,
&rack_reorder_fade, 0,
"Does reorder detection fade, if so how many ms (0 means never)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "pktdelay", CTLFLAG_RW,
&rack_pkt_delay, 1,
"Extra RACK time (in ms) besides reordering thresh");
/* Timer related controls */
rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"timers",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Timer related controls");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "persmin", CTLFLAG_RW,
&rack_persist_min, 250,
"What is the minimum time in milliseconds between persists");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "persmax", CTLFLAG_RW,
&rack_persist_max, 2000,
"What is the largest delay in milliseconds between persists");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "delayed_ack", CTLFLAG_RW,
&rack_delayed_ack_time, 200,
"Delayed ack time (200ms)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "minrto", CTLFLAG_RW,
&rack_rto_min, 0,
"Minimum RTO in ms -- set with caution below 1000 due to TLP");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "maxrto", CTLFLAG_RW,
&rack_rto_max, 0,
"Maxiumum RTO in ms -- should be at least as large as min_rto");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "minto", CTLFLAG_RW,
&rack_min_to, 1,
"Minimum rack timeout in milliseconds");
/* Measure controls */
rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"measure",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Measure related controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "wma_divisor", CTLFLAG_RW,
&rack_wma_divisor, 8,
"When doing b/w calculation what is the divisor for the WMA");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "end_cwnd", CTLFLAG_RW,
&rack_cwnd_block_ends_measure, 0,
"Does a cwnd just-return end the measurement window (app limited)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "end_rwnd", CTLFLAG_RW,
&rack_rwnd_block_ends_measure, 0,
"Does an rwnd just-return end the measurement window (app limited -- not persists)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_target", CTLFLAG_RW,
&rack_def_data_window, 20,
"What is the minimum target window (in mss) for a GP measurements");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "goal_bdp", CTLFLAG_RW,
&rack_goal_bdp, 2,
"What is the goal BDP to measure");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_srtts", CTLFLAG_RW,
&rack_min_srtts, 1,
"What is the goal BDP to measure");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_measure_tim", CTLFLAG_RW,
&rack_min_measure_usec, 0,
"What is the Minimum time time for a measurement if 0, this is off");
/* Misc rack controls */
rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"misc",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Misc related controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "shared_cwnd", CTLFLAG_RW,
&rack_enable_shared_cwnd, 0,
"Should RACK try to use the shared cwnd on connections where allowed");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
&rack_limits_scwnd, 1,
"Should RACK place low end time limits on the shared cwnd feature");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
&rack_enable_mqueue_for_nonpaced, 0,
"Should RACK use mbuf queuing for non-paced connections");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "iMac_dack", CTLFLAG_RW,
&rack_use_imac_dack, 0,
"Should RACK try to emulate iMac delayed ack");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "no_prr", CTLFLAG_RW,
&rack_disable_prr, 0,
"Should RACK not use prr and only pace (must have pacing on)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "bb_verbose", CTLFLAG_RW,
&rack_verbose_logging, 0,
"Should RACK black box logging be verbose");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "data_after_close", CTLFLAG_RW,
&rack_ignore_data_after_close, 1,
"Do we hold off sending a RST until all pending data is ack'd");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "no_sack_needed", CTLFLAG_RW,
&rack_sack_not_required, 0,
"Do we allow rack to run on connections not supporting SACK");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "recovery_loss_prop", CTLFLAG_RW,
&rack_use_proportional_reduce, 0,
"Should we proportionaly reduce cwnd based on the number of losses ");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "recovery_prop", CTLFLAG_RW,
&rack_proportional_rate, 10,
"What percent reduction per loss");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "prr_sendalot", CTLFLAG_RW,
&rack_send_a_lot_in_prr, 1,
"Send a lot in prr");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "earlyrecovery", CTLFLAG_RW,
&rack_early_recovery, 1,
"Do we do early recovery with rack");
/* Sack Attacker detection stuff */
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
&rack_highest_sack_thresh_seen, 0,
"Highest sack to ack ratio seen");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
&rack_highest_move_thresh_seen, 0,
"Highest move to non-move ratio seen");
rack_ack_total = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "acktotal", CTLFLAG_RD,
&rack_ack_total,
"Total number of Ack's");
rack_express_sack = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
&rack_express_sack,
"Total expresss number of Sack's");
rack_sack_total = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "sacktotal", CTLFLAG_RD,
&rack_sack_total,
"Total number of SACKs");
rack_move_none = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "move_none", CTLFLAG_RD,
&rack_move_none,
"Total number of SACK index reuse of postions under threshold");
rack_move_some = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "move_some", CTLFLAG_RD,
&rack_move_some,
"Total number of SACK index reuse of postions over threshold");
rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "attacks", CTLFLAG_RD,
&rack_sack_attacks_detected,
"Total number of SACK attackers that had sack disabled");
rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "reversed", CTLFLAG_RD,
&rack_sack_attacks_reversed,
"Total number of SACK attackers that were later determined false positive");
rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "nextmerge", CTLFLAG_RD,
&rack_sack_used_next_merge,
"Total number of times we used the next merge");
rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "prevmerge", CTLFLAG_RD,
&rack_sack_used_prev_merge,
"Total number of times we used the prev merge");
/* Counters */
rack_badfr = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "badfr", CTLFLAG_RD,
&rack_badfr, "Total number of bad FRs");
rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "badfr_bytes", CTLFLAG_RD,
&rack_badfr_bytes, "Total number of bad FRs");
rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prrsndret", CTLFLAG_RD,
&rack_rtm_prr_retran,
"Total number of prr based retransmits");
rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prrsndnew", CTLFLAG_RD,
&rack_rtm_prr_newdata,
"Total number of prr based new transmits");
rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tsnf", CTLFLAG_RD,
&rack_timestamp_mismatch,
"Total number of timestamps that we could not find the reported ts");
rack_find_high = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "findhigh", CTLFLAG_RD,
&rack_find_high,
"Total number of FIN causing find-high");
rack_reorder_seen = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "reordering", CTLFLAG_RD,
&rack_reorder_seen,
"Total number of times we added delay due to reordering");
rack_tlp_tot = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_to_total", CTLFLAG_RD,
&rack_tlp_tot,
"Total number of tail loss probe expirations");
rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_new", CTLFLAG_RD,
&rack_tlp_newdata,
"Total number of tail loss probe sending new data");
rack_tlp_retran = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran", CTLFLAG_RD,
&rack_tlp_retran,
"Total number of tail loss probe sending retransmitted data");
rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
&rack_tlp_retran_bytes,
"Total bytes of tail loss probe sending retransmitted data");
rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
&rack_tlp_retran_fail,
"Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
rack_to_tot = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "rack_to_tot", CTLFLAG_RD,
&rack_to_tot,
"Total number of times the rack to expired");
rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "arm_rack", CTLFLAG_RD,
&rack_to_arm_rack,
"Total number of times the rack timer armed");
rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "arm_tlp", CTLFLAG_RD,
&rack_to_arm_tlp,
"Total number of times the tlp timer armed");
rack_calc_zero = counter_u64_alloc(M_WAITOK);
rack_calc_nonzero = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "calc_zero", CTLFLAG_RD,
&rack_calc_zero,
"Total number of times pacing time worked out to zero");
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "calc_nonzero", CTLFLAG_RD,
&rack_calc_nonzero,
"Total number of times pacing time worked out to non-zero");
rack_paced_segments = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "paced", CTLFLAG_RD,
&rack_paced_segments,
"Total number of times a segment send caused hptsi");
rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "unpaced", CTLFLAG_RD,
&rack_unpaced_segments,
"Total number of times a segment did not cause hptsi");
rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "saw_enobufs", CTLFLAG_RD,
&rack_saw_enobuf,
"Total number of times a segment did not cause hptsi");
rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
&rack_saw_enetunreach,
"Total number of times a segment did not cause hptsi");
rack_to_alloc = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allocs", CTLFLAG_RD,
&rack_to_alloc,
"Total allocations of tracking structures");
rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allochard", CTLFLAG_RD,
&rack_to_alloc_hard,
"Total allocations done with sleeping the hard way");
rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allocemerg", CTLFLAG_RD,
&rack_to_alloc_emerg,
"Total allocations done from emergency cache");
rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "alloc_limited", CTLFLAG_RD,
&rack_to_alloc_limited,
"Total allocations dropped due to limit");
rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
&rack_alloc_limited_conns,
"Connections with allocations dropped due to limit");
rack_split_limited = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "split_limited", CTLFLAG_RD,
&rack_split_limited,
"Split allocations dropped due to limit");
rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_long", CTLFLAG_RD,
&rack_sack_proc_all,
"Total times we had to walk whole list for sack processing");
rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_restart", CTLFLAG_RD,
&rack_sack_proc_restart,
"Total times we had to walk whole list due to a restart");
rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_short", CTLFLAG_RD,
&rack_sack_proc_short,
"Total times we took shortcut for sack processing");
rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
&rack_enter_tlp_calc,
"Total times we called calc-tlp");
rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
&rack_used_tlpmethod,
"Total number of runt sacks");
rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
&rack_used_tlpmethod2,
"Total number of times we hit TLP method 2");
rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "skipacked", CTLFLAG_RD,
&rack_sack_skipped_acked,
"Total number of times we skipped previously sacked");
rack_sack_splits = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "ofsplit", CTLFLAG_RD,
&rack_sack_splits,
"Total number of times we did the old fashion tree split");
rack_progress_drops = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prog_drops", CTLFLAG_RD,
&rack_progress_drops,
"Total number of progress drops");
rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
&rack_input_idle_reduces,
"Total number of idle reductions on input");
rack_collapsed_win = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "collapsed_win", CTLFLAG_RD,
&rack_collapsed_win,
"Total number of collapsed windows");
rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_nada", CTLFLAG_RD,
&rack_tlp_does_nada,
"Total number of nada tlp calls");
rack_try_scwnd = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tried_scwnd", CTLFLAG_RD,
&rack_try_scwnd,
"Total number of scwnd attempts");
rack_tls_rwnd = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_rwnd", CTLFLAG_RD,
&rack_tls_rwnd,
"Total hdwr tls rwnd limited");
rack_tls_cwnd = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_cwnd", CTLFLAG_RD,
&rack_tls_cwnd,
"Total hdwr tls cwnd limited");
rack_tls_app = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_app", CTLFLAG_RD,
&rack_tls_app,
"Total hdwr tls app limited");
rack_tls_other = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_other", CTLFLAG_RD,
&rack_tls_other,
"Total hdwr tls other limited");
rack_tls_filled = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_filled", CTLFLAG_RD,
&rack_tls_filled,
"Total hdwr tls filled");
rack_tls_rxt = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_rxt", CTLFLAG_RD,
&rack_tls_rxt,
"Total hdwr rxt");
rack_tls_tlp = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tls_tlp", CTLFLAG_RD,
&rack_tls_tlp,
"Total hdwr tls tlp");
rack_per_timer_hole = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "timer_hole", CTLFLAG_RD,
&rack_per_timer_hole,
"Total persists start in timer hole");
COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "outsize", CTLFLAG_RD,
rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "opts", CTLFLAG_RD,
rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
SYSCTL_ADD_PROC(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
&rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
}
static __inline int
rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
{
if (SEQ_GEQ(b->r_start, a->r_start) &&
SEQ_LT(b->r_start, a->r_end)) {
/*
* The entry b is within the
* block a. i.e.:
* a -- |-------------|
* b -- |----|
* <or>
* b -- |------|
* <or>
* b -- |-----------|
*/
return (0);
} else if (SEQ_GEQ(b->r_start, a->r_end)) {
/*
* b falls as either the next
* sequence block after a so a
* is said to be smaller than b.
* i.e:
* a -- |------|
* b -- |--------|
* or
* b -- |-----|
*/
return (1);
}
/*
* Whats left is where a is
* larger than b. i.e:
* a -- |-------|
* b -- |---|
* or even possibly
* b -- |--------------|
*/
return (-1);
}
RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
static uint32_t
rc_init_window(struct tcp_rack *rack)
{
uint32_t win;
if (rack->rc_init_win == 0) {
/*
* Nothing set by the user, use the system stack
* default.
*/
return(tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
}
win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
return(win);
}
static uint64_t
rack_get_fixed_pacing_bw(struct tcp_rack *rack)
{
if (IN_RECOVERY(rack->rc_tp->t_flags))
return (rack->r_ctl.rc_fixed_pacing_rate_rec);
else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
return (rack->r_ctl.rc_fixed_pacing_rate_ss);
else
return (rack->r_ctl.rc_fixed_pacing_rate_ca);
}
static uint64_t
rack_get_bw(struct tcp_rack *rack)
{
if (rack->use_fixed_rate) {
/* Return the fixed pacing rate */
return (rack_get_fixed_pacing_bw(rack));
}
if (rack->r_ctl.gp_bw == 0) {
/*
* We have yet no b/w measurement,
* if we have a user set initial bw
* return it. If we don't have that and
* we have an srtt, use the tcp IW (10) to
* calculate a fictional b/w over the SRTT
* which is more or less a guess. Note
* we don't use our IW from rack on purpose
* so if we have like IW=30, we are not
* calculating a "huge" b/w.
*/
uint64_t bw, srtt;
if (rack->r_ctl.init_rate)
return (rack->r_ctl.init_rate);
/* Has the user set a max peak rate? */
#ifdef NETFLIX_PEAKRATE
if (rack->rc_tp->t_maxpeakrate)
return (rack->rc_tp->t_maxpeakrate);
#endif
/* Ok lets come up with the IW guess, if we have a srtt */
if (rack->rc_tp->t_srtt == 0) {
/*
* Go with old pacing method
* i.e. burst mitigation only.
*/
return (0);
}
/* Ok lets get the initial TCP win (not racks) */
bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
srtt = ((uint64_t)TICKS_2_USEC(rack->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
bw *= (uint64_t)USECS_IN_SECOND;
bw /= srtt;
return (bw);
} else {
uint64_t bw;
if(rack->r_ctl.num_avg >= RACK_REQ_AVG) {
/* Averaging is done, we can return the value */
bw = rack->r_ctl.gp_bw;
} else {
/* Still doing initial average must calculate */
bw = rack->r_ctl.gp_bw / rack->r_ctl.num_avg;
}
#ifdef NETFLIX_PEAKRATE
if ((rack->rc_tp->t_maxpeakrate) &&
(bw > rack->rc_tp->t_maxpeakrate)) {
/* The user has set a peak rate to pace at
* don't allow us to pace faster than that.
*/
return (rack->rc_tp->t_maxpeakrate);
}
#endif
return (bw);
}
}
static uint16_t
rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
if (rack->use_fixed_rate) {
return (100);
} else if (rack->in_probe_rtt && (rsm == NULL))
return(rack->r_ctl.rack_per_of_gp_probertt);
else if ((IN_RECOVERY(rack->rc_tp->t_flags) &&
rack->r_ctl.rack_per_of_gp_rec)) {
if (rsm) {
/* a retransmission always use the recovery rate */
return(rack->r_ctl.rack_per_of_gp_rec);
} else if (rack->rack_rec_nonrxt_use_cr) {
/* Directed to use the configured rate */
goto configured_rate;
} else if (rack->rack_no_prr &&
(rack->r_ctl.rack_per_of_gp_rec > 100)) {
/* No PRR, lets just use the b/w estimate only */
return(100);
} else {
/*
* Here we may have a non-retransmit but we
* have no overrides, so just use the recovery
* rate (prr is in effect).
*/
return(rack->r_ctl.rack_per_of_gp_rec);
}
}
configured_rate:
/* For the configured rate we look at our cwnd vs the ssthresh */
if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
return (rack->r_ctl.rack_per_of_gp_ss);
else
return(rack->r_ctl.rack_per_of_gp_ca);
}
static uint64_t
rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm)
{
/*
* We allow rack_per_of_gp_xx to dictate our bw rate we want.
*/
uint64_t bw_est;
uint64_t gain;
gain = (uint64_t)rack_get_output_gain(rack, rsm);
bw_est = bw * gain;
bw_est /= (uint64_t)100;
/* Never fall below the minimum (def 64kbps) */
if (bw_est < RACK_MIN_BW)
bw_est = RACK_MIN_BW;
return (bw_est);
}
static void
rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
if ((mod != 1) && (rack_verbose_logging == 0)) {
/*
* We get 3 values currently for mod
* 1 - We are retransmitting and this tells the reason.
* 2 - We are clearing a dup-ack count.
* 3 - We are incrementing a dup-ack count.
*
* The clear/increment are only logged
* if you have BBverbose on.
*/
return;
}
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = tsused;
log.u_bbr.flex2 = thresh;
log.u_bbr.flex3 = rsm->r_flags;
log.u_bbr.flex4 = rsm->r_dupack;
log.u_bbr.flex5 = rsm->r_start;
log.u_bbr.flex6 = rsm->r_end;
log.u_bbr.flex8 = mod;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_SETTINGS_CHG, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = TICKS_2_MSEC(rack->rc_tp->t_srtt >> TCP_RTT_SHIFT);
log.u_bbr.flex2 = to * 1000;
log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = slot;
log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
log.u_bbr.flex7 = rack->rc_in_persist;
log.u_bbr.flex8 = which;
if (rack->rack_no_prr)
log.u_bbr.pkts_out = 0;
else
log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERSTAR, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex8 = to_num;
log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
log.u_bbr.flex2 = rack->rc_rack_rtt;
if (rsm == NULL)
log.u_bbr.flex3 = 0;
else
log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_RTO, 0,
0, &log, false, &tv);
}
}
static void
rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
struct rack_sendmap *rsm, int conf)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = t;
log.u_bbr.flex2 = len;
log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt * HPTS_USEC_IN_MSEC;
log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest * HPTS_USEC_IN_MSEC;
log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest * HPTS_USEC_IN_MSEC;
log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt;
log.u_bbr.flex7 = conf;
log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot * (uint64_t)HPTS_USEC_IN_MSEC;
log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
if (rack->rack_no_prr)
log.u_bbr.pkts_out = 0;
else
log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtt;
log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
if (rsm) {
log.u_bbr.pkt_epoch = rsm->r_start;
log.u_bbr.lost = rsm->r_end;
log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
} else {
/* Its a SYN */
log.u_bbr.pkt_epoch = rack->rc_tp->iss;
log.u_bbr.lost = 0;
log.u_bbr.cwnd_gain = 0;
}
/* Write out general bits of interest rrs here */
log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->forced_ack;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
TCP_LOG_EVENTP(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRRTT, 0,
0, &log, false, &tv);
}
}
static void
rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
{
/*
* Log the rtt sample we are
* applying to the srtt algorithm in
* useconds.
*/
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
/* Convert our ms to a microsecond */
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = rtt * 1000;
log.u_bbr.flex2 = rack->r_ctl.ack_count;
log.u_bbr.flex3 = rack->r_ctl.sack_count;
log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
log.u_bbr.flex8 = rack->sack_attack_disable;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_LOG_RTT, 0,
0, &log, false, &tv);
}
}
static inline void
rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line)
{
if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = tick;
log.u_bbr.flex3 = tp->t_maxunacktime;
log.u_bbr.flex4 = tp->t_acktime;
log.u_bbr.flex8 = event;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_PROGRESS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = slot;
if (rack->rack_no_prr)
log.u_bbr.flex2 = 0;
else
log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.timeStamp = cts;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRSND, 0,
0, &log, false, tv);
}
}
static void
rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = did_out;
log.u_bbr.flex2 = nxt_pkt;
log.u_bbr.flex3 = way_out;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex7 = rack->r_wanted_output;
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_DOSEG_DONE, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_hrdwtso(struct tcpcb *tp, struct tcp_rack *rack, int len, int mod, int32_t orig_len, int frm)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
uint32_t cts;
memset(&log, 0, sizeof(log));
cts = tcp_get_usecs(&tv);
log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex4 = len;
log.u_bbr.flex5 = orig_len;
log.u_bbr.flex6 = rack->r_ctl.rc_sacked;
log.u_bbr.flex7 = mod;
log.u_bbr.flex8 = frm;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(tp, NULL,
&tp->t_inpcb->inp_socket->so_rcv,
&tp->t_inpcb->inp_socket->so_snd,
TCP_HDWR_TLS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = slot;
log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = reason;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex7 = hpts_calling;
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.lt_epoch = cwnd_to_use;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_JUSTRET, 0,
tlen, &log, false, &tv);
}
}
static void
rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
struct timeval *tv, uint32_t flags_on_entry)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
log.u_bbr.flex3 = flags_on_entry;
log.u_bbr.flex4 = us_cts;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
log.u_bbr.flex7 = hpts_removed;
log.u_bbr.flex8 = 1;
log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
log.u_bbr.timeStamp = us_cts;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERCANC, 0,
0, &log, false, tv);
}
}
static void
rack_log_alt_to_to_cancel(struct tcp_rack *rack,
uint32_t flex1, uint32_t flex2,
uint32_t flex3, uint32_t flex4,
uint32_t flex5, uint32_t flex6,
uint16_t flex7, uint8_t mod)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
if (mod == 1) {
/* No you can't use 1, its for the real to cancel */
return;
}
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.flex1 = flex1;
log.u_bbr.flex2 = flex2;
log.u_bbr.flex3 = flex3;
log.u_bbr.flex4 = flex4;
log.u_bbr.flex5 = flex5;
log.u_bbr.flex6 = flex6;
log.u_bbr.flex7 = flex7;
log.u_bbr.flex8 = mod;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERCANC, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = timers;
log.u_bbr.flex2 = ret;
log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex5 = cts;
if (rack->rack_no_prr)
log.u_bbr.flex6 = 0;
else
log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TO_PROCESS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
if (rack->rack_no_prr)
log.u_bbr.flex3 = 0;
else
log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
log.u_bbr.flex8 = frm;
log.u_bbr.pkts_out = orig_cwnd;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRUPD, 0,
0, &log, false, &tv);
}
}
#ifdef NETFLIX_EXP_DETECTION
static void
rack_log_sad(struct tcp_rack *rack, int event)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = rack->r_ctl.sack_count;
log.u_bbr.flex2 = rack->r_ctl.ack_count;
log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
log.u_bbr.lt_epoch = (tcp_force_detection << 8);
log.u_bbr.lt_epoch |= rack->do_detection;
log.u_bbr.applimited = tcp_map_minimum;
log.u_bbr.flex7 = rack->sack_attack_disable;
log.u_bbr.flex8 = event;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.delivered = tcp_sad_decay_val;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_SAD_DETECTION, 0,
0, &log, false, &tv);
}
}
#endif
static void
rack_counter_destroy(void)
{
counter_u64_free(rack_ack_total);
counter_u64_free(rack_express_sack);
counter_u64_free(rack_sack_total);
counter_u64_free(rack_move_none);
counter_u64_free(rack_move_some);
counter_u64_free(rack_sack_attacks_detected);
counter_u64_free(rack_sack_attacks_reversed);
counter_u64_free(rack_sack_used_next_merge);
counter_u64_free(rack_sack_used_prev_merge);
counter_u64_free(rack_badfr);
counter_u64_free(rack_badfr_bytes);
counter_u64_free(rack_rtm_prr_retran);
counter_u64_free(rack_rtm_prr_newdata);
counter_u64_free(rack_timestamp_mismatch);
counter_u64_free(rack_find_high);
counter_u64_free(rack_reorder_seen);
counter_u64_free(rack_tlp_tot);
counter_u64_free(rack_tlp_newdata);
counter_u64_free(rack_tlp_retran);
counter_u64_free(rack_tlp_retran_bytes);
counter_u64_free(rack_tlp_retran_fail);
counter_u64_free(rack_to_tot);
counter_u64_free(rack_to_arm_rack);
counter_u64_free(rack_to_arm_tlp);
counter_u64_free(rack_calc_zero);
counter_u64_free(rack_calc_nonzero);
counter_u64_free(rack_paced_segments);
counter_u64_free(rack_unpaced_segments);
counter_u64_free(rack_saw_enobuf);
counter_u64_free(rack_saw_enetunreach);
counter_u64_free(rack_to_alloc);
counter_u64_free(rack_to_alloc_hard);
counter_u64_free(rack_to_alloc_emerg);
counter_u64_free(rack_to_alloc_limited);
counter_u64_free(rack_alloc_limited_conns);
counter_u64_free(rack_split_limited);
counter_u64_free(rack_sack_proc_all);
counter_u64_free(rack_sack_proc_restart);
counter_u64_free(rack_sack_proc_short);
counter_u64_free(rack_enter_tlp_calc);
counter_u64_free(rack_used_tlpmethod);
counter_u64_free(rack_used_tlpmethod2);
counter_u64_free(rack_sack_skipped_acked);
counter_u64_free(rack_sack_splits);
counter_u64_free(rack_progress_drops);
counter_u64_free(rack_input_idle_reduces);
counter_u64_free(rack_collapsed_win);
counter_u64_free(rack_tlp_does_nada);
counter_u64_free(rack_try_scwnd);
counter_u64_free(rack_tls_rwnd);
counter_u64_free(rack_tls_cwnd);
counter_u64_free(rack_tls_app);
counter_u64_free(rack_tls_other);
counter_u64_free(rack_tls_filled);
counter_u64_free(rack_tls_rxt);
counter_u64_free(rack_tls_tlp);
counter_u64_free(rack_per_timer_hole);
COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
}
static struct rack_sendmap *
rack_alloc(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
rsm = uma_zalloc(rack_zone, M_NOWAIT);
if (rsm) {
rack->r_ctl.rc_num_maps_alloced++;
counter_u64_add(rack_to_alloc, 1);
return (rsm);
}
if (rack->rc_free_cnt) {
counter_u64_add(rack_to_alloc_emerg, 1);
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
rack->rc_free_cnt--;
return (rsm);
}
return (NULL);
}
static struct rack_sendmap *
rack_alloc_full_limit(struct tcp_rack *rack)
{
if ((V_tcp_map_entries_limit > 0) &&
(rack->do_detection == 0) &&
(rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
counter_u64_add(rack_to_alloc_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
return (NULL);
}
return (rack_alloc(rack));
}
/* wrapper to allocate a sendmap entry, subject to a specific limit */
static struct rack_sendmap *
rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
{
struct rack_sendmap *rsm;
if (limit_type) {
/* currently there is only one limit type */
if (V_tcp_map_split_limit > 0 &&
(rack->do_detection == 0) &&
rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
counter_u64_add(rack_split_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
return (NULL);
}
}
/* allocate and mark in the limit type, if set */
rsm = rack_alloc(rack);
if (rsm != NULL && limit_type) {
rsm->r_limit_type = limit_type;
rack->r_ctl.rc_num_split_allocs++;
}
return (rsm);
}
static void
rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
if (rsm->r_flags & RACK_APP_LIMITED) {
if (rack->r_ctl.rc_app_limited_cnt > 0) {
rack->r_ctl.rc_app_limited_cnt--;
}
}
if (rsm->r_limit_type) {
/* currently there is only one limit type */
rack->r_ctl.rc_num_split_allocs--;
}
if (rsm == rack->r_ctl.rc_first_appl) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_first_appl = NULL;
else {
/* Follow the next one out */
struct rack_sendmap fe;
fe.r_start = rsm->r_nseq_appl;
rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
}
}
if (rsm == rack->r_ctl.rc_resend)
rack->r_ctl.rc_resend = NULL;
if (rsm == rack->r_ctl.rc_rsm_at_retran)
rack->r_ctl.rc_rsm_at_retran = NULL;
if (rsm == rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl = NULL;
if (rack->r_ctl.rc_tlpsend == rsm)
rack->r_ctl.rc_tlpsend = NULL;
if (rack->r_ctl.rc_sacklast == rsm)
rack->r_ctl.rc_sacklast = NULL;
if (rack->rc_free_cnt < rack_free_cache) {
memset(rsm, 0, sizeof(struct rack_sendmap));
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
rsm->r_limit_type = 0;
rack->rc_free_cnt++;
return;
}
rack->r_ctl.rc_num_maps_alloced--;
uma_zfree(rack_zone, rsm);
}
static uint32_t
rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
{
uint64_t srtt, bw, len, tim;
uint32_t segsiz, def_len, minl;
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
def_len = rack_def_data_window * segsiz;
if (rack->rc_gp_filled == 0) {
/*
* We have no measurement (IW is in flight?) so
* we can only guess using our data_window sysctl
* value (usually 100MSS).
*/
return (def_len);
}
/*
* Now we have a number of factors to consider.
*
* 1) We have a desired BDP which is usually
* at least 2.
* 2) We have a minimum number of rtt's usually 1 SRTT
* but we allow it too to be more.
* 3) We want to make sure a measurement last N useconds (if
* we have set rack_min_measure_usec.
*
* We handle the first concern here by trying to create a data
* window of max(rack_def_data_window, DesiredBDP). The
* second concern we handle in not letting the measurement
* window end normally until at least the required SRTT's
* have gone by which is done further below in
* rack_enough_for_measurement(). Finally the third concern
* we also handle here by calculating how long that time
* would take at the current BW and then return the
* max of our first calculation and that length. Note
* that if rack_min_measure_usec is 0, we don't deal
* with concern 3. Also for both Concern 1 and 3 an
* application limited period could end the measurement
* earlier.
*
* So lets calculate the BDP with the "known" b/w using
* the SRTT has our rtt and then multiply it by the
* goal.
*/
bw = rack_get_bw(rack);
srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
len = bw * srtt;
len /= (uint64_t)HPTS_USEC_IN_SEC;
len *= max(1, rack_goal_bdp);
/* Now we need to round up to the nearest MSS */
len = roundup(len, segsiz);
if (rack_min_measure_usec) {
/* Now calculate our min length for this b/w */
tim = rack_min_measure_usec;
minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
if (minl == 0)
minl = 1;
minl = roundup(minl, segsiz);
if (len < minl)
len = minl;
}
/*
* Now if we have a very small window we want
* to attempt to get the window that is
* as small as possible. This happens on
* low b/w connections and we don't want to
* span huge numbers of rtt's between measurements.
*
* We basically include 2 over our "MIN window" so
* that the measurement can be shortened (possibly) by
* an ack'ed packet.
*/
if (len < def_len)
return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
else
return (max((uint32_t)len, def_len));
}
static int
rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack)
{
uint32_t tim, srtts, segsiz;
/*
* Has enough time passed for the GP measurement to be valid?
*/
if ((tp->snd_max == tp->snd_una) ||
(th_ack == tp->snd_max)){
/* All is acked */
return (1);
}
if (SEQ_LT(th_ack, tp->gput_seq)) {
/* Not enough bytes yet */
return (0);
}
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
if (SEQ_LT(th_ack, tp->gput_ack) &&
((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
/* Not enough bytes yet */
return (0);
}
if (rack->r_ctl.rc_first_appl &&
(rack->r_ctl.rc_first_appl->r_start == th_ack)) {
/*
* We are up to the app limited point
* we have to measure irrespective of the time..
*/
return (1);
}
/* Now what about time? */
srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
if (tim >= srtts) {
return (1);
}
/* Nope not even a full SRTT has passed */
return (0);
}
static void
rack_log_timely(struct tcp_rack *rack,
uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
uint64_t up_bnd, int line, uint8_t method)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = logged;
log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_incr;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_bwred;
log.u_bbr.flex3 = rack->rc_gp_incr;
log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.flex7 = rack->rc_gp_bwred;
log.u_bbr.flex8 = method;
log.u_bbr.cur_del_rate = cur_bw;
log.u_bbr.delRate = low_bnd;
log.u_bbr.bw_inuse = up_bnd;
log.u_bbr.rttProp = rack_get_bw(rack);
log.u_bbr.pkt_epoch = line;
log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
log.u_bbr.lost = rack->r_ctl.rc_loss_count;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_TIMELY_WORK, 0,
0, &log, false, &tv);
}
}
static int
rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
{
/*
* Before we increase we need to know if
* the estimate just made was less than
* our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
*
* If we already are pacing at a fast enough
* rate to push us faster there is no sense of
* increasing.
*
* We first caculate our actual pacing rate (ss or ca multipler
* times our cur_bw).
*
* Then we take the last measured rate and multipy by our
* maximum pacing overage to give us a max allowable rate.
*
* If our act_rate is smaller than our max_allowable rate
* then we should increase. Else we should hold steady.
*
*/
uint64_t act_rate, max_allow_rate;
if (rack_timely_no_stopping)
return (1);
if ((cur_bw == 0) || (last_bw_est == 0)) {
/*
* Initial startup case or
* everything is acked case.
*/
rack_log_timely(rack, mult, cur_bw, 0, 0,
__LINE__, 9);
return (1);
}
if (mult <= 100) {
/*
* We can always pace at or slightly above our rate.
*/
rack_log_timely(rack, mult, cur_bw, 0, 0,
__LINE__, 9);
return (1);
}
act_rate = cur_bw * (uint64_t)mult;
act_rate /= 100;
max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
max_allow_rate /= 100;
if (act_rate < max_allow_rate) {
/*
* Here the rate we are actually pacing at
* is smaller than 10% above our last measurement.
* This means we are pacing below what we would
* like to try to achieve (plus some wiggle room).
*/
rack_log_timely(rack, mult, cur_bw, act_rate, max_allow_rate,
__LINE__, 9);
return (1);
} else {
/*
* Here we are already pacing at least rack_max_per_above(10%)
* what we are getting back. This indicates most likely
* that we are being limited (cwnd/rwnd/app) and can't
* get any more b/w. There is no sense of trying to
* raise up the pacing rate its not speeding us up
* and we already are pacing faster than we are getting.
*/
rack_log_timely(rack, mult, cur_bw, act_rate, max_allow_rate,
__LINE__, 8);
return (0);
}
}
static void
rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
{
/*
* When we drag bottom, we want to assure
* that no multiplier is below 1.0, if so
* we want to restore it to at least that.
*/
if (rack->r_ctl.rack_per_of_gp_rec < 100) {
/* This is unlikely we usually do not touch recovery */
rack->r_ctl.rack_per_of_gp_rec = 100;
}
if (rack->r_ctl.rack_per_of_gp_ca < 100) {
rack->r_ctl.rack_per_of_gp_ca = 100;
}
if (rack->r_ctl.rack_per_of_gp_ss < 100) {
rack->r_ctl.rack_per_of_gp_ss = 100;
}
}
static void
rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
{
if (rack->r_ctl.rack_per_of_gp_ca > 100) {
rack->r_ctl.rack_per_of_gp_ca = 100;
}
if (rack->r_ctl.rack_per_of_gp_ss > 100) {
rack->r_ctl.rack_per_of_gp_ss = 100;
}
}
static void
rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
{
int32_t calc, logged, plus;
logged = 0;
if (override) {
/*
* override is passed when we are
* loosing b/w and making one last
* gasp at trying to not loose out
* to a new-reno flow.
*/
goto extra_boost;
}
/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
if (rack->rc_gp_incr &&
((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
/*
* Reset and get 5 strokes more before the boost. Note
* that the count is 0 based so we have to add one.
*/
extra_boost:
plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
rack->rc_gp_timely_inc_cnt = 0;
} else
plus = (uint32_t)rack_gp_increase_per;
/* Must be at least 1% increase for true timely increases */
if ((plus < 1) &&
((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
plus = 1;
if (rack->rc_gp_saw_rec &&
(rack->rc_gp_no_rec_chg == 0) &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_rec)) {
/* We have been in recovery ding it too */
calc = rack->r_ctl.rack_per_of_gp_rec + plus;
if (calc > 0xffff)
calc = 0xffff;
logged |= 1;
rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
if (rack_per_upper_bound_ss &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
}
if (rack->rc_gp_saw_ca &&
(rack->rc_gp_saw_ss == 0) &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_ca)) {
/* In CA */
calc = rack->r_ctl.rack_per_of_gp_ca + plus;
if (calc > 0xffff)
calc = 0xffff;
logged |= 2;
rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
if (rack_per_upper_bound_ca &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
}
if (rack->rc_gp_saw_ss &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_ss)) {
/* In SS */
calc = rack->r_ctl.rack_per_of_gp_ss + plus;
if (calc > 0xffff)
calc = 0xffff;
rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
if (rack_per_upper_bound_ss &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
logged |= 4;
}
if (logged &&
(rack->rc_gp_incr == 0)){
/* Go into increment mode */
rack->rc_gp_incr = 1;
rack->rc_gp_timely_inc_cnt = 0;
}
if (rack->rc_gp_incr &&
logged &&
(rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
rack->rc_gp_timely_inc_cnt++;
}
rack_log_timely(rack, logged, plus, 0, 0,
__LINE__, 1);
}
static uint32_t
rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
{
/*
* norm_grad = rtt_diff / minrtt;
* new_per = curper * (1 - B * norm_grad)
*
* B = rack_gp_decrease_per (default 10%)
* rtt_dif = input var current rtt-diff
* curper = input var current percentage
* minrtt = from rack filter
*
*/
uint64_t perf;
perf = (((uint64_t)curper * ((uint64_t)1000000 -
((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
(((uint64_t)rtt_diff * (uint64_t)1000000)/
(uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
(uint64_t)1000000)) /
(uint64_t)1000000);
if (perf > curper) {
/* TSNH */
perf = curper - 1;
}
return ((uint32_t)perf);
}
static uint32_t
rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
{
/*
* highrttthresh
* result = curper * (1 - (B * ( 1 - ------ ))
* gp_srtt
*
* B = rack_gp_decrease_per (default 10%)
* highrttthresh = filter_min * rack_gp_rtt_maxmul
*/
uint64_t perf;
uint32_t highrttthresh;
highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
perf = (((uint64_t)curper * ((uint64_t)1000000 -
((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
((uint64_t)highrttthresh * (uint64_t)1000000) /
(uint64_t)rtt)) / 100)) /(uint64_t)1000000);
return (perf);
}
static void
rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
{
uint64_t logvar, logvar2, logvar3;
uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
if (rack->rc_gp_incr) {
/* Turn off increment counting */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
}
ss_red = ca_red = rec_red = 0;
logged = 0;
/* Calculate the reduction value */
if (rtt_diff < 0) {
rtt_diff *= -1;
}
/* Must be at least 1% reduction */
if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
/* We have been in recovery ding it too */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_rec > val) {
rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
} else {
rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
rec_red = 0;
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
logged |= 1;
}
if (rack->rc_gp_saw_ss) {
/* Sent in SS */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
} else {
ss_red = new_per;
rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
logvar = new_per;
logvar <<= 32;
logvar |= alt;
logvar2 = (uint32_t)rtt;
logvar2 <<= 32;
logvar2 |= (uint32_t)rtt_diff;
logvar3 = rack_gp_rtt_maxmul;
logvar3 <<= 32;
logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
rack_log_timely(rack, timely_says,
logvar2, logvar3,
logvar, __LINE__, 10);
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
logged |= 4;
} else if (rack->rc_gp_saw_ca) {
/* Sent in CA */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_ca > val) {
ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
} else {
rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
ca_red = 0;
logvar = new_per;
logvar <<= 32;
logvar |= alt;
logvar2 = (uint32_t)rtt;
logvar2 <<= 32;
logvar2 |= (uint32_t)rtt_diff;
logvar3 = rack_gp_rtt_maxmul;
logvar3 <<= 32;
logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
rack_log_timely(rack, timely_says,
logvar2, logvar3,
logvar, __LINE__, 10);
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
logged |= 2;
}
if (rack->rc_gp_timely_dec_cnt < 0x7) {
rack->rc_gp_timely_dec_cnt++;
if (rack_timely_dec_clear &&
(rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
rack->rc_gp_timely_dec_cnt = 0;
}
logvar = ss_red;
logvar <<= 32;
logvar |= ca_red;
rack_log_timely(rack, logged, rec_red, rack_per_lower_bound, logvar,
__LINE__, 2);
}
static void
rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
uint32_t rtt, uint32_t line, uint8_t reas)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex5 = rtt;
log.u_bbr.flex6 = rack->rc_highly_buffered;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->forced_ack;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->in_probe_rtt;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.flex8 = reas;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.delRate = rack_get_bw(rack);
log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
log.u_bbr.cur_del_rate <<= 32;
log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
log.u_bbr.rttProp = us_cts;
log.u_bbr.rttProp <<= 32;
log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_RTT_SHRINKS, 0,
0, &log, false, &rack->r_ctl.act_rcv_time);
}
}
static void
rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
{
uint64_t bwdp;
bwdp = rack_get_bw(rack);
bwdp *= (uint64_t)rtt;
bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
/*
* A window protocol must be able to have 4 packets
* outstanding as the floor in order to function
* (especially considering delayed ack :D).
*/
rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
}
}
static void
rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
{
/**
* ProbeRTT is a bit different in rack_pacing than in
* BBR. It is like BBR in that it uses the lowering of
* the RTT as a signal that we saw something new and
* counts from there for how long between. But it is
* different in that its quite simple. It does not
* play with the cwnd and wait until we get down
* to N segments outstanding and hold that for
* 200ms. Instead it just sets the pacing reduction
* rate to a set percentage (70 by default) and hold
* that for a number of recent GP Srtt's.
*/
uint32_t segsiz;
if (rack->rc_gp_dyn_mul == 0)
return;
if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
/* We are idle */
return;
}
if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
/*
* Stop the goodput now, the idea here is
* that future measurements with in_probe_rtt
* won't register if they are not greater so
* we want to get what info (if any) is available
* now.
*/
rack_do_goodput_measurement(rack->rc_tp, rack,
rack->rc_tp->snd_una, __LINE__);
}
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
rack->r_ctl.rc_time_probertt_entered = us_cts;
segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
rack->r_ctl.rc_pace_min_segs);
rack->in_probe_rtt = 1;
rack->measure_saw_probe_rtt = 1;
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_starts = 0;
rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
if (rack_probertt_use_min_rtt_entry)
rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
else
rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
rack_log_rtt_shrinks(rack, us_cts, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_ENTERPROBE);
}
static void
rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
{
struct rack_sendmap *rsm;
uint32_t segsiz;
segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
rack->r_ctl.rc_pace_min_segs);
rack->in_probe_rtt = 0;
if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
/*
* Stop the goodput now, the idea here is
* that future measurements with in_probe_rtt
* won't register if they are not greater so
* we want to get what info (if any) is available
* now.
*/
rack_do_goodput_measurement(rack->rc_tp, rack,
rack->rc_tp->snd_una, __LINE__);
} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
/*
* We don't have enough data to make a measurement.
* So lets just stop and start here after exiting
* probe-rtt. We probably are not interested in
* the results anyway.
*/
rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
}
/*
* Measurements through the current snd_max are going
* to be limited by the slower pacing rate.
*
* We need to mark these as app-limited so we
* don't collapse the b/w.
*/
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
else {
/*
* Go out to the end app limited and mark
* this new one as next and move the end_appl up
* to this guy.
*/
if (rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
rack->r_ctl.rc_end_appl = rsm;
}
rsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
/*
* Now, we need to examine our pacing rate multipliers.
* If its under 100%, we need to kick it back up to
* 100%. We also don't let it be over our "max" above
* the actual rate i.e. 100% + rack_clamp_atexit_prtt.
* Note setting clamp_atexit_prtt to 0 has the effect
* of setting CA/SS to 100% always at exit (which is
* the default behavior).
*/
if (rack_probertt_clear_is) {
rack->rc_gp_incr = 0;
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_inc_cnt = 0;
rack->rc_gp_timely_dec_cnt = 0;
}
/* Do we do any clamping at exit? */
if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
}
if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
}
/*
* Lets set rtt_diff to 0, so that we will get a "boost"
* after exiting.
*/
rack->r_ctl.rc_rtt_diff = 0;
/* Clear all flags so we start fresh */
rack->rc_tp->t_bytes_acked = 0;
rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
/*
* If configured to, set the cwnd and ssthresh to
* our targets.
*/
if (rack_probe_rtt_sets_cwnd) {
uint64_t ebdp;
uint32_t setto;
/* Set ssthresh so we get into CA once we hit our target */
if (rack_probertt_use_min_rtt_exit == 1) {
/* Set to min rtt */
rack_set_prtt_target(rack, segsiz,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
} else if (rack_probertt_use_min_rtt_exit == 2) {
/* Set to current gp rtt */
rack_set_prtt_target(rack, segsiz,
rack->r_ctl.rc_gp_srtt);
} else if (rack_probertt_use_min_rtt_exit == 3) {
/* Set to entry gp rtt */
rack_set_prtt_target(rack, segsiz,
rack->r_ctl.rc_entry_gp_rtt);
} else {
uint64_t sum;
uint32_t setval;
sum = rack->r_ctl.rc_entry_gp_rtt;
sum *= 10;
sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
if (sum >= 20) {
/*
* A highly buffered path needs
* cwnd space for timely to work.
* Lets set things up as if
* we are heading back here again.
*/
setval = rack->r_ctl.rc_entry_gp_rtt;
} else if (sum >= 15) {
/*
* Lets take the smaller of the
* two since we are just somewhat
* buffered.
*/
setval = rack->r_ctl.rc_gp_srtt;
if (setval > rack->r_ctl.rc_entry_gp_rtt)
setval = rack->r_ctl.rc_entry_gp_rtt;
} else {
/*
* Here we are not highly buffered
* and should pick the min we can to
* keep from causing loss.
*/
setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
}
rack_set_prtt_target(rack, segsiz,
setval);
}
if (rack_probe_rtt_sets_cwnd > 1) {
/* There is a percentage here to boost */
ebdp = rack->r_ctl.rc_target_probertt_flight;
ebdp *= rack_probe_rtt_sets_cwnd;
ebdp /= 100;
setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
} else
setto = rack->r_ctl.rc_target_probertt_flight;
rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
/* Enforce a min */
rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
}
/* If we set in the cwnd also set the ssthresh point so we are in CA */
rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
}
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_EXITPROBE);
/* Clear times last so log has all the info */
rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
rack->r_ctl.rc_time_probertt_entered = us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_of_last_probertt = us_cts;
}
static void
rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
{
/* Check in on probe-rtt */
if (rack->rc_gp_filled == 0) {
/* We do not do p-rtt unless we have gp measurements */
return;
}
if (rack->in_probe_rtt) {
uint64_t no_overflow;
uint32_t endtime, must_stay;
if (rack->r_ctl.rc_went_idle_time &&
((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
/*
* We went idle during prtt, just exit now.
*/
rack_exit_probertt(rack, us_cts);
} else if (rack_probe_rtt_safety_val &&
TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
/*
* Probe RTT safety value triggered!
*/
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_SAFETY);
rack_exit_probertt(rack, us_cts);
}
/* Calculate the max we will wait */
endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
if (rack->rc_highly_buffered)
endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
/* Calculate the min we must wait */
must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
TSTMP_LT(us_cts, endtime)) {
uint32_t calc;
/* Do we lower more? */
no_exit:
if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
else
calc = 0;
calc /= max(rack->r_ctl.rc_gp_srtt, 1);
if (calc) {
/* Maybe */
calc *= rack_per_of_gp_probertt_reduce;
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
/* Limit it too */
if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
}
/* We must reach target or the time set */
return;
}
if (rack->r_ctl.rc_time_probertt_starts == 0) {
if ((TSTMP_LT(us_cts, must_stay) &&
rack->rc_highly_buffered) ||
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
rack->r_ctl.rc_target_probertt_flight)) {
/* We are not past the must_stay time */
goto no_exit;
}
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_REACHTARGET);
rack->r_ctl.rc_time_probertt_starts = us_cts;
if (rack->r_ctl.rc_time_probertt_starts == 0)
rack->r_ctl.rc_time_probertt_starts = 1;
/* Restore back to our rate we want to pace at in prtt */
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
}
/*
* Setup our end time, some number of gp_srtts plus 200ms.
*/
no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
(uint64_t)rack_probertt_gpsrtt_cnt_mul);
if (rack_probertt_gpsrtt_cnt_div)
endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
else
endtime = 0;
endtime += rack_min_probertt_hold;
endtime += rack->r_ctl.rc_time_probertt_starts;
if (TSTMP_GEQ(us_cts, endtime)) {
/* yes, exit probertt */
rack_exit_probertt(rack, us_cts);
}
} else if((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
/* Go into probertt, its been too long since we went lower */
rack_enter_probertt(rack, us_cts);
}
}
static void
rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
uint32_t rtt, int32_t rtt_diff)
{
uint64_t cur_bw, up_bnd, low_bnd, subfr;
uint32_t losses;
if ((rack->rc_gp_dyn_mul == 0) ||
(rack->use_fixed_rate) ||
(rack->in_probe_rtt) ||
(rack->rc_always_pace == 0)) {
/* No dynamic GP multipler in play */
return;
}
losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
cur_bw = rack_get_bw(rack);
/* Calculate our up and down range */
up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
up_bnd /= 100;
up_bnd += rack->r_ctl.last_gp_comp_bw;
subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
subfr /= 100;
low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
/*
* This is the case where our RTT is above
* the max target and we have been configured
* to just do timely no bonus up stuff in that case.
*
* There are two configurations, set to 1, and we
* just do timely if we are over our max. If its
* set above 1 then we slam the multipliers down
* to 100 and then decrement per timely.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
if (rack->r_ctl.rc_no_push_at_mrtt > 1)
rack_validate_multipliers_at_or_below_100(rack);
rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
} else if ((last_bw_est < low_bnd) && !losses) {
/*
* We are decreasing this is a bit complicated this
* means we are loosing ground. This could be
* because another flow entered and we are competing
* for b/w with it. This will push the RTT up which
* makes timely unusable unless we want to get shoved
* into a corner and just be backed off (the age
* old problem with delay based CC).
*
* On the other hand if it was a route change we
* would like to stay somewhat contained and not
* blow out the buffers.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
rack->r_ctl.last_gp_comp_bw = cur_bw;
if (rack->rc_gp_bwred == 0) {
/* Go into reduction counting */
rack->rc_gp_bwred = 1;
rack->rc_gp_timely_dec_cnt = 0;
}
if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
(timely_says == 0)) {
/*
* Push another time with a faster pacing
* to try to gain back (we include override to
* get a full raise factor).
*/
if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
(rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
(timely_says == 0) ||
(rack_down_raise_thresh == 0)) {
/*
* Do an override up in b/w if we were
* below the threshold or if the threshold
* is zero we always do the raise.
*/
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
} else {
/* Log it stays the same */
rack_log_timely(rack, 0, last_bw_est, low_bnd, 0,
__LINE__, 11);
}
rack->rc_gp_timely_dec_cnt++;
/* We are not incrementing really no-count */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
} else {
/*
* Lets just use the RTT
* information and give up
* pushing.
*/
goto use_timely;
}
} else if ((timely_says != 2) &&
!losses &&
(last_bw_est > up_bnd)) {
/*
* We are increasing b/w lets keep going, updating
* our b/w and ignoring any timely input, unless
* of course we are at our max raise (if there is one).
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
rack->r_ctl.last_gp_comp_bw = cur_bw;
if (rack->rc_gp_saw_ss &&
rack_per_upper_bound_ss &&
(rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
/*
* In cases where we can't go higher
* we should just use timely.
*/
goto use_timely;
}
if (rack->rc_gp_saw_ca &&
rack_per_upper_bound_ca &&
(rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
/*
* In cases where we can't go higher
* we should just use timely.
*/
goto use_timely;
}
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_dec_cnt = 0;
/* You get a set number of pushes if timely is trying to reduce */
if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
} else {
/* Log it stays the same */
rack_log_timely(rack, 0, last_bw_est, up_bnd, 0,
__LINE__, 12);
}
return;
} else {
/*
* We are staying between the lower and upper range bounds
* so use timely to decide.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
use_timely:
if (timely_says) {
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
!losses &&
(last_bw_est < low_bnd)) {
/* We are loosing ground */
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
rack->rc_gp_timely_dec_cnt++;
/* We are not incrementing really no-count */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
} else
rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
} else {
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_dec_cnt = 0;
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
}
}
}
static int32_t
rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
{
int32_t timely_says;
uint64_t log_mult, log_rtt_a_diff;
log_rtt_a_diff = rtt;
log_rtt_a_diff <<= 32;
log_rtt_a_diff |= (uint32_t)rtt_diff;
if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
rack_gp_rtt_maxmul)) {
/* Reduce the b/w multipler */
timely_says = 2;
log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
log_mult <<= 32;
log_mult |= prev_rtt;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
log_rtt_a_diff, __LINE__, 4);
} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
max(rack_gp_rtt_mindiv , 1)))) {
/* Increase the b/w multipler */
log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
max(rack_gp_rtt_mindiv , 1));
log_mult <<= 32;
log_mult |= prev_rtt;
timely_says = 0;
rack_log_timely(rack, timely_says, log_mult ,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
log_rtt_a_diff, __LINE__, 5);
} else {
/*
* Use a gradient to find it the timely gradient
* is:
* grad = rc_rtt_diff / min_rtt;
*
* anything below or equal to 0 will be
* a increase indication. Anything above
* zero is a decrease. Note we take care
* of the actual gradient calculation
* in the reduction (its not needed for
* increase).
*/
log_mult = prev_rtt;
if (rtt_diff <= 0) {
/*
* Rttdiff is less than zero, increase the
* b/w multipler (its 0 or negative)
*/
timely_says = 0;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
} else {
/* Reduce the b/w multipler */
timely_says = 1;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
}
}
return (timely_says);
}
static void
rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq th_ack, int line)
{
uint64_t tim, bytes_ps, ltim, stim, utim;
uint32_t segsiz, bytes, reqbytes, us_cts;
int32_t gput, new_rtt_diff, timely_says;
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
if (TSTMP_GEQ(us_cts, tp->gput_ts))
tim = us_cts - tp->gput_ts;
else
tim = 0;
if (TSTMP_GT(rack->r_ctl.rc_gp_cumack_ts, rack->r_ctl.rc_gp_output_ts))
stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
else
stim = 0;
/*
* Use the larger of the send time or ack time. This prevents us
* from being influenced by ack artifacts to come up with too
* high of measurement. Note that since we are spanning over many more
* bytes in most of our measurements hopefully that is less likely to
* occur.
*/
if (tim > stim)
utim = max(tim, 1);
else
utim = max(stim, 1);
/* Lets validate utim */
ltim = max(1, (utim/HPTS_USEC_IN_MSEC));
gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
if ((tim == 0) && (stim == 0)) {
/*
* Invalid measurement time, maybe
* all on one ack/one send?
*/
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
/* We never made a us_rtt measurement? */
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
/*
* Calculate the maximum possible b/w this connection
* could have. We base our calculation on the lowest
* rtt we have seen during the measurement and the
* largest rwnd the client has given us in that time. This
* forms a BDP that is the maximum that we could ever
* get to the client. Anything larger is not valid.
*
* I originally had code here that rejected measurements
* where the time was less than 1/2 the latest us_rtt.
* But after thinking on that I realized its wrong since
* say you had a 150Mbps or even 1Gbps link, and you
* were a long way away.. example I am in Europe (100ms rtt)
* talking to my 1Gbps link in S.C. Now measuring say 150,000
* bytes my time would be 1.2ms, and yet my rtt would say
* the measurement was invalid the time was < 50ms. The
* same thing is true for 150Mb (8ms of time).
*
* A better way I realized is to look at what the maximum
* the connection could possibly do. This is gated on
* the lowest RTT we have seen and the highest rwnd.
* We should in theory never exceed that, if we are
* then something on the path is storing up packets
* and then feeding them all at once to our endpoint
* messing up our measurement.
*/
rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
if (SEQ_LT(th_ack, tp->gput_seq)) {
/* No measurement can be made */
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
} else
bytes = (th_ack - tp->gput_seq);
bytes_ps = (uint64_t)bytes;
/*
* Don't measure a b/w for pacing unless we have gotten at least
* an initial windows worth of data in this measurement interval.
*
* Small numbers of bytes get badly influenced by delayed ack and
* other artifacts. Note we take the initial window or our
* defined minimum GP (defaulting to 10 which hopefully is the
* IW).
*/
if (rack->rc_gp_filled == 0) {
/*
* The initial estimate is special. We
* have blasted out an IW worth of packets
* without a real valid ack ts results. We
* then setup the app_limited_needs_set flag,
* this should get the first ack in (probably 2
* MSS worth) to be recorded as the timestamp.
* We thus allow a smaller number of bytes i.e.
* IW - 2MSS.
*/
reqbytes -= (2 * segsiz);
/* Also lets fill previous for our first measurement to be neutral */
rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
}
if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
rack->r_ctl.rc_app_limited_cnt,
0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
/*
* We now need to calculate the Timely like status so
* we can update (possibly) the b/w multipliers.
*/
new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
if (rack->rc_gp_filled == 0) {
/* No previous reading */
rack->r_ctl.rc_rtt_diff = new_rtt_diff;
} else {
if (rack->measure_saw_probe_rtt == 0) {
/*
* We don't want a probertt to be counted
* since it will be negative incorrectly. We
* expect to be reducing the RTT when we
* pace at a slower rate.
*/
rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
}
}
timely_says = rack_make_timely_judgement(rack,
rack->r_ctl.rc_gp_srtt,
rack->r_ctl.rc_rtt_diff,
rack->r_ctl.rc_prev_gp_srtt
);
bytes_ps *= HPTS_USEC_IN_SEC;
bytes_ps /= utim;
if (bytes_ps > rack->r_ctl.last_max_bw) {
/*
* Something is on path playing
* since this b/w is not possible based
* on our BDP (highest rwnd and lowest rtt
* we saw in the measurement window).
*
* Another option here would be to
* instead skip the measurement.
*/
rack_log_pacing_delay_calc(rack, bytes, reqbytes,
bytes_ps, rack->r_ctl.last_max_bw, 0,
11, __LINE__, NULL);
bytes_ps = rack->r_ctl.last_max_bw;
}
/* We store gp for b/w in bytes per second */
if (rack->rc_gp_filled == 0) {
/* Initial measurment */
if (bytes_ps) {
rack->r_ctl.gp_bw = bytes_ps;
rack->rc_gp_filled = 1;
rack->r_ctl.num_avg = 1;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else {
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
rack->r_ctl.rc_app_limited_cnt,
0, 0, 10, __LINE__, NULL);
}
if (rack->rc_inp->inp_in_hpts &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/*
* Ok we can't trust the pacer in this case
* where we transition from un-paced to paced.
* Or for that matter when the burst mitigation
* was making a wild guess and got it wrong.
* Stop the pacer and clear up all the aggregate
* delays etc.
*/
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack->r_ctl.rc_hpts_flags = 0;
rack->r_ctl.rc_last_output_to = 0;
}
} else if (rack->r_ctl.num_avg < RACK_REQ_AVG) {
/* Still a small number run an average */
rack->r_ctl.gp_bw += bytes_ps;
rack->r_ctl.num_avg++;
if (rack->r_ctl.num_avg >= RACK_REQ_AVG) {
/* We have collected enought to move forward */
rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_avg;
}
} else {
/*
* We want to take 1/wma of the goodput and add in to 7/8th
* of the old value weighted by the srtt. So if your measurement
* period is say 2 SRTT's long you would get 1/4 as the
* value, if it was like 1/2 SRTT then you would get 1/16th.
*
* But we must be careful not to take too much i.e. if the
* srtt is say 20ms and the measurement is taken over
* 400ms our weight would be 400/20 i.e. 20. On the
* other hand if we get a measurement over 1ms with a
* 10ms rtt we only want to take a much smaller portion.
*/
uint64_t resid_bw, subpart, addpart, srtt;
srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
if (srtt == 0) {
/*
* Strange why did t_srtt go back to zero?
*/
if (rack->r_ctl.rc_rack_min_rtt)
srtt = (rack->r_ctl.rc_rack_min_rtt * HPTS_USEC_IN_MSEC);
else
srtt = HPTS_USEC_IN_MSEC;
}
/*
* XXXrrs: Note for reviewers, in playing with
* dynamic pacing I discovered this GP calculation
* as done originally leads to some undesired results.
* Basically you can get longer measurements contributing
* too much to the WMA. Thus I changed it if you are doing
* dynamic adjustments to only do the aportioned adjustment
* if we have a very small (time wise) measurement. Longer
* measurements just get there weight (defaulting to 1/8)
* add to the WMA. We may want to think about changing
* this to always do that for both sides i.e. dynamic
* and non-dynamic... but considering lots of folks
* were playing with this I did not want to change the
* calculation per.se. without your thoughts.. Lawerence?
* Peter??
*/
if (rack->rc_gp_dyn_mul == 0) {
subpart = rack->r_ctl.gp_bw * utim;
subpart /= (srtt * 8);
if (subpart < (rack->r_ctl.gp_bw / 2)) {
/*
* The b/w update takes no more
* away then 1/2 our running total
* so factor it in.
*/
addpart = bytes_ps * utim;
addpart /= (srtt * 8);
} else {
/*
* Don't allow a single measurement
* to account for more than 1/2 of the
* WMA. This could happen on a retransmission
* where utim becomes huge compared to
* srtt (multiple retransmissions when using
* the sending rate which factors in all the
* transmissions from the first one).
*/
subpart = rack->r_ctl.gp_bw / 2;
addpart = bytes_ps / 2;
}
resid_bw = rack->r_ctl.gp_bw - subpart;
rack->r_ctl.gp_bw = resid_bw + addpart;
} else {
if ((utim / srtt) <= 1) {
/*
* The b/w update was over a small period
* of time. The idea here is to prevent a small
* measurement time period from counting
* too much. So we scale it based on the
* time so it attributes less than 1/rack_wma_divisor
* of its measurement.
*/
subpart = rack->r_ctl.gp_bw * utim;
subpart /= (srtt * rack_wma_divisor);
addpart = bytes_ps * utim;
addpart /= (srtt * rack_wma_divisor);
} else {
/*
* The scaled measurement was long
* enough so lets just add in the
* portion of the measurment i.e. 1/rack_wma_divisor
*/
subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
addpart = bytes_ps / rack_wma_divisor;
}
if ((rack->measure_saw_probe_rtt == 0) ||
(bytes_ps > rack->r_ctl.gp_bw)) {
/*
* For probe-rtt we only add it in
* if its larger, all others we just
* add in.
*/
resid_bw = rack->r_ctl.gp_bw - subpart;
rack->r_ctl.gp_bw = resid_bw + addpart;
}
}
}
/* We do not update any multipliers if we are in or have seen a probe-rtt */
if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
rack_update_multiplier(rack, timely_says, bytes_ps,
rack->r_ctl.rc_gp_srtt,
rack->r_ctl.rc_rtt_diff);
rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
rack_get_bw(rack), 3, line, NULL);
/* reset the gp srtt and setup the new prev */
rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
/* Record the lost count for the next measurement */
rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
/*
* We restart our diffs based on the gpsrtt in the
* measurement window.
*/
rack->rc_gp_rtt_set = 0;
rack->rc_gp_saw_rec = 0;
rack->rc_gp_saw_ca = 0;
rack->rc_gp_saw_ss = 0;
rack->rc_dragged_bottom = 0;
skip_measurement:
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
gput);
/*
* XXXLAS: This is a temporary hack, and should be
* chained off VOI_TCP_GPUT when stats(9) grows an
* API to deal with chained VOIs.
*/
if (tp->t_stats_gput_prev > 0)
stats_voi_update_abs_s32(tp->t_stats,
VOI_TCP_GPUT_ND,
((gput - tp->t_stats_gput_prev) * 100) /
tp->t_stats_gput_prev);
#endif
tp->t_flags &= ~TF_GPUTINPROG;
tp->t_stats_gput_prev = gput;
/*
* Now are we app limited now and there is space from where we
* were to where we want to go?
*
* We don't do the other case i.e. non-applimited here since
* the next send will trigger us picking up the missing data.
*/
if (rack->r_ctl.rc_first_appl &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
rack->r_ctl.rc_app_limited_cnt &&
(SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
((rack->r_ctl.rc_first_appl->r_start - th_ack) >
max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
/*
* Yep there is enough outstanding to make a measurement here.
*/
struct rack_sendmap *rsm, fe;
tp->t_flags |= TF_GPUTINPROG;
rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rack->app_limited_needs_set = 0;
tp->gput_seq = th_ack;
if (rack->in_probe_rtt)
rack->measure_saw_probe_rtt = 1;
else if ((rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
if ((rack->r_ctl.rc_first_appl->r_start - th_ack) >= rack_get_measure_window(tp, rack)) {
/* There is a full window to gain info from */
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
} else {
/* We can only measure up to the applimited point */
tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_start - th_ack);
}
/*
* Now we need to find the timestamp of the send at tp->gput_seq
* for the send based measurement.
*/
fe.r_start = tp->gput_seq;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm) {
/* Ok send-based limit is set */
if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
/*
* Move back to include the earlier part
* so our ack time lines up right (this may
* make an overlapping measurement but thats
* ok).
*/
tp->gput_seq = rsm->r_start;
}
if (rsm->r_flags & RACK_ACKED)
tp->gput_ts = rsm->r_ack_arrival;
else
rack->app_limited_needs_set = 1;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
} else {
/*
* If we don't find the rsm due to some
* send-limit set the current time, which
* basically disables the send-limit.
*/
rack->r_ctl.rc_gp_output_ts = tcp_get_usecs(NULL);
}
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
}
}
/*
* CC wrapper hook functions
*/
static void
rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, struct tcphdr *th, uint16_t nsegs,
uint16_t type, int32_t recovery)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
tp->ccv->nsegs = nsegs;
tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);
if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
uint32_t max;
max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
if (tp->ccv->bytes_this_ack > max) {
tp->ccv->bytes_this_ack = max;
}
}
if (rack->r_ctl.cwnd_to_use <= tp->snd_wnd)
tp->ccv->flags |= CCF_CWND_LIMITED;
else
tp->ccv->flags &= ~CCF_CWND_LIMITED;
#ifdef STATS
stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
#endif
if ((tp->t_flags & TF_GPUTINPROG) &&
rack_enough_for_measurement(tp, rack, th->th_ack)) {
/* Measure the Goodput */
rack_do_goodput_measurement(tp, rack, th->th_ack, __LINE__);
#ifdef NETFLIX_PEAKRATE
if ((type == CC_ACK) &&
(tp->t_maxpeakrate)) {
/*
* We update t_peakrate_thr. This gives us roughly
* one update per round trip time. Note
* it will only be used if pace_always is off i.e
* we don't do this for paced flows.
*/
tcp_update_peakrate_thr(tp);
}
#endif
}
if (rack->r_ctl.cwnd_to_use > tp->snd_ssthresh) {
tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
tp->ccv->flags |= CCF_ABC_SENTAWND;
}
} else {
tp->ccv->flags &= ~CCF_ABC_SENTAWND;
tp->t_bytes_acked = 0;
}
if (CC_ALGO(tp)->ack_received != NULL) {
/* XXXLAS: Find a way to live without this */
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->ack_received(tp->ccv, type);
}
#ifdef STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
#endif
if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
}
#ifdef NETFLIX_PEAKRATE
/* we enforce max peak rate if it is set and we are not pacing */
if ((rack->rc_always_pace == 0) &&
tp->t_peakrate_thr &&
(tp->snd_cwnd > tp->t_peakrate_thr)) {
tp->snd_cwnd = tp->t_peakrate_thr;
}
#endif
}
static void
tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* If we are doing PRR and have enough
* room to send <or> we are pacing and prr
* is disabled we will want to see if we
* can send data (by setting r_wanted_output to
* true).
*/
if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
rack->rack_no_prr)
rack->r_wanted_output = 1;
}
static void
rack_post_recovery(struct tcpcb *tp, struct tcphdr *th)
{
struct tcp_rack *rack;
uint32_t orig_cwnd;
orig_cwnd = tp->snd_cwnd;
INP_WLOCK_ASSERT(tp->t_inpcb);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_not_backing_off == 0) {
/* only alert CC if we alerted when we entered */
if (CC_ALGO(tp)->post_recovery != NULL) {
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->post_recovery(tp->ccv);
}
if (tp->snd_cwnd > tp->snd_ssthresh) {
/* Drop us down to the ssthresh (1/2 cwnd at loss) */
tp->snd_cwnd = tp->snd_ssthresh;
}
}
if ((rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt > 0)) {
/* Suck the next prr cnt back into cwnd */
tp->snd_cwnd += rack->r_ctl.rc_prr_sndcnt;
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 1, 0);
}
rack_log_to_prr(rack, 14, orig_cwnd);
tp->snd_recover = tp->snd_una;
EXIT_RECOVERY(tp->t_flags);
}
static void
rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
{
struct tcp_rack *rack;
INP_WLOCK_ASSERT(tp->t_inpcb);
rack = (struct tcp_rack *)tp->t_fb_ptr;
switch (type) {
case CC_NDUPACK:
tp->t_flags &= ~TF_WASFRECOVERY;
tp->t_flags &= ~TF_WASCRECOVERY;
if (!IN_FASTRECOVERY(tp->t_flags)) {
rack->r_ctl.rc_prr_delivered = 0;
rack->r_ctl.rc_prr_out = 0;
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 2, 0);
}
rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
tp->snd_recover = tp->snd_max;
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
}
break;
case CC_ECN:
if (!IN_CONGRECOVERY(tp->t_flags) ||
/*
* Allow ECN reaction on ACK to CWR, if
* that data segment was also CE marked.
*/
SEQ_GEQ(th->th_ack, tp->snd_recover)) {
EXIT_CONGRECOVERY(tp->t_flags);
KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
tp->snd_recover = tp->snd_max + 1;
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
}
break;
case CC_RTO:
tp->t_dupacks = 0;
tp->t_bytes_acked = 0;
EXIT_RECOVERY(tp->t_flags);
tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
tp->snd_cwnd = ctf_fixed_maxseg(tp);
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
break;
case CC_RTO_ERR:
KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
/* RTO was unnecessary, so reset everything. */
tp->snd_cwnd = tp->snd_cwnd_prev;
tp->snd_ssthresh = tp->snd_ssthresh_prev;
tp->snd_recover = tp->snd_recover_prev;
if (tp->t_flags & TF_WASFRECOVERY) {
ENTER_FASTRECOVERY(tp->t_flags);
tp->t_flags &= ~TF_WASFRECOVERY;
}
if (tp->t_flags & TF_WASCRECOVERY) {
ENTER_CONGRECOVERY(tp->t_flags);
tp->t_flags &= ~TF_WASCRECOVERY;
}
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
break;
}
/*
* If we are below our max rtt, don't
* signal the CC control to change things.
* instead set it up so that we are in
* recovery but not going to back off.
*/
if (rack->rc_highly_buffered) {
/*
* Do we use the higher rtt for
* our threshold to not backoff (like CDG)?
*/
uint32_t rtt_mul, rtt_div;
if (rack_use_max_for_nobackoff) {
rtt_mul = (rack_gp_rtt_maxmul - 1);
rtt_div = 1;
} else {
rtt_mul = rack_gp_rtt_minmul;
rtt_div = max(rack_gp_rtt_mindiv , 1);
}
if (rack->r_ctl.rc_gp_srtt <= (rack->r_ctl.rc_lowest_us_rtt +
((rack->r_ctl.rc_lowest_us_rtt * rtt_mul) /
rtt_div))) {
/* below our min threshold */
rack->rc_not_backing_off = 1;
ENTER_RECOVERY(rack->rc_tp->t_flags);
rack_log_rtt_shrinks(rack, 0,
rtt_mul,
rtt_div,
RACK_RTTS_NOBACKOFF);
return;
}
}
rack->rc_not_backing_off = 0;
if (CC_ALGO(tp)->cong_signal != NULL) {
if (th != NULL)
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->cong_signal(tp->ccv, type);
}
}
static inline void
rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
{
uint32_t i_cwnd;
INP_WLOCK_ASSERT(tp->t_inpcb);
#ifdef NETFLIX_STATS
KMOD_TCPSTAT_INC(tcps_idle_restarts);
if (tp->t_state == TCPS_ESTABLISHED)
KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
#endif
if (CC_ALGO(tp)->after_idle != NULL)
CC_ALGO(tp)->after_idle(tp->ccv);
if (tp->snd_cwnd == 1)
i_cwnd = tp->t_maxseg; /* SYN(-ACK) lost */
else
i_cwnd = rc_init_window(rack);
/*
* Being idle is no differnt than the initial window. If the cc
* clamps it down below the initial window raise it to the initial
* window.
*/
if (tp->snd_cwnd < i_cwnd) {
tp->snd_cwnd = i_cwnd;
}
}
/*
* Indicate whether this ack should be delayed. We can delay the ack if
* following conditions are met:
* - There is no delayed ack timer in progress.
* - Our last ack wasn't a 0-sized window. We never want to delay
* the ack that opens up a 0-sized window.
* - LRO wasn't used for this segment. We make sure by checking that the
* segment size is not larger than the MSS.
* - Delayed acks are enabled or this is a half-synchronized T/TCP
* connection.
*/
#define DELAY_ACK(tp, tlen) \
(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
((tp->t_flags & TF_DELACK) == 0) && \
(tlen <= tp->t_maxseg) && \
(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
static struct rack_sendmap *
rack_find_lowest_rsm(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
/*
* Walk the time-order transmitted list looking for an rsm that is
* not acked. This will be the one that was sent the longest time
* ago that is still outstanding.
*/
TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
if (rsm->r_flags & RACK_ACKED) {
continue;
}
goto finish;
}
finish:
return (rsm);
}
static struct rack_sendmap *
rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
struct rack_sendmap *prsm;
/*
* Walk the sequence order list backward until we hit and arrive at
* the highest seq not acked. In theory when this is called it
* should be the last segment (which it was not).
*/
counter_u64_add(rack_find_high, 1);
prsm = rsm;
RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
continue;
}
return (prsm);
}
return (NULL);
}
static uint32_t
rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
{
int32_t lro;
uint32_t thresh;
/*
* lro is the flag we use to determine if we have seen reordering.
* If it gets set we have seen reordering. The reorder logic either
* works in one of two ways:
*
* If reorder-fade is configured, then we track the last time we saw
* re-ordering occur. If we reach the point where enough time as
* passed we no longer consider reordering has occuring.
*
* Or if reorder-face is 0, then once we see reordering we consider
* the connection to alway be subject to reordering and just set lro
* to 1.
*
* In the end if lro is non-zero we add the extra time for
* reordering in.
*/
if (srtt == 0)
srtt = 1;
if (rack->r_ctl.rc_reorder_ts) {
if (rack->r_ctl.rc_reorder_fade) {
if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
lro = cts - rack->r_ctl.rc_reorder_ts;
if (lro == 0) {
/*
* No time as passed since the last
* reorder, mark it as reordering.
*/
lro = 1;
}
} else {
/* Negative time? */
lro = 0;
}
if (lro > rack->r_ctl.rc_reorder_fade) {
/* Turn off reordering seen too */
rack->r_ctl.rc_reorder_ts = 0;
lro = 0;
}
} else {
/* Reodering does not fade */
lro = 1;
}
} else {
lro = 0;
}
thresh = srtt + rack->r_ctl.rc_pkt_delay;
if (lro) {
/* It must be set, if not you get 1/4 rtt */
if (rack->r_ctl.rc_reorder_shift)
thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
else
thresh += (srtt >> 2);
} else {
thresh += 1;
}
/* We don't let the rack timeout be above a RTO */
if (thresh > TICKS_2_MSEC(rack->rc_tp->t_rxtcur)) {
thresh = TICKS_2_MSEC(rack->rc_tp->t_rxtcur);
}
/* And we don't want it above the RTO max either */
if (thresh > rack_rto_max) {
thresh = rack_rto_max;
}
return (thresh);
}
static uint32_t
rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t srtt)
{
struct rack_sendmap *prsm;
uint32_t thresh, len;
int segsiz;
if (srtt == 0)
srtt = 1;
if (rack->r_ctl.rc_tlp_threshold)
thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
else
thresh = (srtt * 2);
/* Get the previous sent packet, if any */
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
counter_u64_add(rack_enter_tlp_calc, 1);
len = rsm->r_end - rsm->r_start;
if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
/* Exactly like the ID */
if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
uint32_t alt_thresh;
/*
* Compensate for delayed-ack with the d-ack time.
*/
counter_u64_add(rack_used_tlpmethod, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
/* 2.1 behavior */
prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
if (prsm && (len <= segsiz)) {
/*
* Two packets outstanding, thresh should be (2*srtt) +
* possible inter-packet delay (if any).
*/
uint32_t inter_gap = 0;
int idx, nidx;
counter_u64_add(rack_used_tlpmethod, 1);
idx = rsm->r_rtr_cnt - 1;
nidx = prsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
/* Yes it was sent later (or at the same time) */
inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
}
thresh += inter_gap;
} else if (len <= segsiz) {
/*
* Possibly compensate for delayed-ack.
*/
uint32_t alt_thresh;
counter_u64_add(rack_used_tlpmethod2, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
/* 2.2 behavior */
if (len <= segsiz) {
uint32_t alt_thresh;
/*
* Compensate for delayed-ack with the d-ack time.
*/
counter_u64_add(rack_used_tlpmethod, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
}
/* Not above an RTO */
if (thresh > TICKS_2_MSEC(tp->t_rxtcur)) {
thresh = TICKS_2_MSEC(tp->t_rxtcur);
}
/* Not above a RTO max */
if (thresh > rack_rto_max) {
thresh = rack_rto_max;
}
/* Apply user supplied min TLP */
if (thresh < rack_tlp_min) {
thresh = rack_tlp_min;
}
return (thresh);
}
static uint32_t
rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
{
/*
* We want the rack_rtt which is the
* last rtt we measured. However if that
* does not exist we fallback to the srtt (which
* we probably will never do) and then as a last
* resort we use RACK_INITIAL_RTO if no srtt is
* yet set.
*/
if (rack->rc_rack_rtt)
return(rack->rc_rack_rtt);
else if (tp->t_srtt == 0)
return(RACK_INITIAL_RTO);
return (TICKS_2_MSEC(tp->t_srtt >> TCP_RTT_SHIFT));
}
static struct rack_sendmap *
rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
{
/*
* Check to see that we don't need to fall into recovery. We will
* need to do so if our oldest transmit is past the time we should
* have had an ack.
*/
struct tcp_rack *rack;
struct rack_sendmap *rsm;
int32_t idx;
uint32_t srtt, thresh;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
return (NULL);
}
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm == NULL)
return (NULL);
if (rsm->r_flags & RACK_ACKED) {
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL)
return (NULL);
}
idx = rsm->r_rtr_cnt - 1;
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_rack(rack, srtt, tsused);
if (TSTMP_LT(tsused, rsm->r_tim_lastsent[idx])) {
return (NULL);
}
if ((tsused - rsm->r_tim_lastsent[idx]) < thresh) {
return (NULL);
}
/* Ok if we reach here we are over-due and this guy can be sent */
if (IN_RECOVERY(tp->t_flags) == 0) {
/*
* For the one that enters us into recovery record undo
* info.
*/
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
}
rack_cong_signal(tp, NULL, CC_NDUPACK);
return (rsm);
}
static uint32_t
rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
{
int32_t t;
int32_t tt;
uint32_t ret_val;
t = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT) + ((tp->t_rttvar * 4) >> TCP_RTT_SHIFT));
TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
rack_persist_min, rack_persist_max);
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
ret_val = (uint32_t)tt;
return (ret_val);
}
static uint32_t
rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
{
/*
* Start the FR timer, we do this based on getting the first one in
* the rc_tmap. Note that if its NULL we must stop the timer. in all
* events we need to stop the running timer (if its running) before
* starting the new one.
*/
uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
uint32_t srtt_cur;
int32_t idx;
int32_t is_tlp_timer = 0;
struct rack_sendmap *rsm;
if (rack->t_timers_stopped) {
/* All timers have been stopped none are to run */
return (0);
}
if (rack->rc_in_persist) {
/* We can't start any timer in persists */
return (rack_get_persists_timer_val(tp, rack));
}
rack->rc_on_min_to = 0;
if ((tp->t_state < TCPS_ESTABLISHED) ||
((tp->t_flags & TF_SACK_PERMIT) == 0))
goto activate_rxt;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if ((rsm == NULL) || sup_rack) {
/* Nothing on the send map */
activate_rxt:
time_since_sent = 0;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm) {
idx = rsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(cts, tstmp_touse))
time_since_sent = cts - tstmp_touse;
}
if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
to = TICKS_2_MSEC(tp->t_rxtcur);
if (to > time_since_sent)
to -= time_since_sent;
else
to = rack->r_ctl.rc_min_to;
if (to == 0)
to = 1;
return (to);
}
return (0);
}
if (rsm->r_flags & RACK_ACKED) {
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL) {
/* No lowest? */
goto activate_rxt;
}
}
if (rack->sack_attack_disable) {
/*
* We don't want to do
* any TLP's if you are an attacker.
* Though if you are doing what
* is expected you may still have
* SACK-PASSED marks.
*/
goto activate_rxt;
}
/* Convert from ms to usecs */
if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
if ((tp->t_flags & TF_SENTFIN) &&
((tp->snd_max - tp->snd_una) == 1) &&
(rsm->r_flags & RACK_HAS_FIN)) {
/*
* We don't start a rack timer if all we have is a
* FIN outstanding.
*/
goto activate_rxt;
}
if ((rack->use_rack_rr == 0) &&
(IN_RECOVERY(tp->t_flags)) &&
(rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) {
/*
* We are not cheating, in recovery and
* not enough ack's to yet get our next
* retransmission out.
*
* Note that classified attackers do not
* get to use the rack-cheat.
*/
goto activate_tlp;
}
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_rack(rack, srtt, cts);
idx = rsm->r_rtr_cnt - 1;
exp = rsm->r_tim_lastsent[idx] + thresh;
if (SEQ_GEQ(exp, cts)) {
to = exp - cts;
if (to < rack->r_ctl.rc_min_to) {
to = rack->r_ctl.rc_min_to;
if (rack->r_rr_config == 3)
rack->rc_on_min_to = 1;
}
} else {
to = rack->r_ctl.rc_min_to;
if (rack->r_rr_config == 3)
rack->rc_on_min_to = 1;
}
} else {
/* Ok we need to do a TLP not RACK */
activate_tlp:
if ((rack->rc_tlp_in_progress != 0) &&
(rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
/*
* The previous send was a TLP and we have sent
* N TLP's without sending new data.
*/
goto activate_rxt;
}
rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
if (rsm == NULL) {
/* We found no rsm to TLP with. */
goto activate_rxt;
}
if (rsm->r_flags & RACK_HAS_FIN) {
/* If its a FIN we dont do TLP */
rsm = NULL;
goto activate_rxt;
}
idx = rsm->r_rtr_cnt - 1;
time_since_sent = 0;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(cts, tstmp_touse))
time_since_sent = cts - tstmp_touse;
is_tlp_timer = 1;
if (tp->t_srtt) {
srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT);
srtt = TICKS_2_MSEC(srtt_cur);
} else
srtt = RACK_INITIAL_RTO;
/*
* If the SRTT is not keeping up and the
* rack RTT has spiked we want to use
* the last RTT not the smoothed one.
*/
if (rack_tlp_use_greater && (srtt < rack_grab_rtt(tp, rack)))
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
if (thresh > time_since_sent)
to = thresh - time_since_sent;
else {
to = rack->r_ctl.rc_min_to;
rack_log_alt_to_to_cancel(rack,
thresh, /* flex1 */
time_since_sent, /* flex2 */
tstmp_touse, /* flex3 */
rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
rsm->r_tim_lastsent[idx],
srtt,
idx, 99);
}
if (to > TCPTV_REXMTMAX) {
/*
* If the TLP time works out to larger than the max
* RTO lets not do TLP.. just RTO.
*/
goto activate_rxt;
}
}
if (is_tlp_timer == 0) {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
} else {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
}
if (to == 0)
to = 1;
return (to);
}
static void
rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (rack->rc_in_persist == 0) {
if (tp->t_flags & TF_GPUTINPROG) {
/*
* Stop the goodput now, the calling of the
* measurement function clears the flag.
*/
rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__);
}
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 1;
}
#endif
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_timer_cancel(tp, rack, cts, __LINE__);
tp->t_rxtshift = 0;
rack->rc_in_persist = 1;
}
}
static void
rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (rack->rc_inp->inp_in_hpts) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack->r_ctl.rc_hpts_flags = 0;
}
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 0;
}
#endif
if (rack->rc_gp_dyn_mul &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/*
* Do we count this as if a probe-rtt just
* finished?
*/
uint32_t time_idle, idle_min;
time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
idle_min = rack_min_probertt_hold;
if (rack_probertt_gpsrtt_cnt_div) {
uint64_t extra;
extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
(uint64_t)rack_probertt_gpsrtt_cnt_mul;
extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
idle_min += (uint32_t)extra;
}
if (time_idle >= idle_min) {
/* Yes, we count it as a probe-rtt. */
uint32_t us_cts;
us_cts = tcp_get_usecs(NULL);
if (rack->in_probe_rtt == 0) {
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
} else {
rack_exit_probertt(rack, us_cts);
}
}
}
rack->rc_in_persist = 0;
rack->r_ctl.rc_went_idle_time = 0;
tp->t_rxtshift = 0;
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
}
static void
rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
struct hpts_diag *diag, struct timeval *tv)
{
if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = diag->p_nxt_slot;
log.u_bbr.flex2 = diag->p_cur_slot;
log.u_bbr.flex3 = diag->slot_req;
log.u_bbr.flex4 = diag->inp_hptsslot;
log.u_bbr.flex5 = diag->slot_remaining;
log.u_bbr.flex6 = diag->need_new_to;
log.u_bbr.flex7 = diag->p_hpts_active;
log.u_bbr.flex8 = diag->p_on_min_sleep;
/* Hijack other fields as needed */
log.u_bbr.epoch = diag->have_slept;
log.u_bbr.lt_epoch = diag->yet_to_sleep;
log.u_bbr.pkts_out = diag->co_ret;
log.u_bbr.applimited = diag->hpts_sleep_time;
log.u_bbr.delivered = diag->p_prev_slot;
log.u_bbr.inflight = diag->p_runningtick;
log.u_bbr.bw_inuse = diag->wheel_tick;
log.u_bbr.rttProp = diag->wheel_cts;
log.u_bbr.timeStamp = cts;
log.u_bbr.delRate = diag->maxticks;
log.u_bbr.cur_del_rate = diag->p_curtick;
log.u_bbr.cur_del_rate <<= 32;
log.u_bbr.cur_del_rate |= diag->p_lasttick;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSDIAG, 0,
0, &log, false, tv);
}
}
static void
rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
int32_t slot, uint32_t tot_len_this_send, int sup_rack)
{
struct hpts_diag diag;
struct inpcb *inp;
struct timeval tv;
uint32_t delayed_ack = 0;
uint32_t hpts_timeout;
uint8_t stopped;
uint32_t left = 0;
uint32_t us_cts;
inp = tp->t_inpcb;
if ((tp->t_state == TCPS_CLOSED) ||
(tp->t_state == TCPS_LISTEN)) {
return;
}
if (inp->inp_in_hpts) {
/* Already on the pacer */
return;
}
stopped = rack->rc_tmr_stopped;
if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
left = rack->r_ctl.rc_timer_exp - cts;
}
rack->r_ctl.rc_timer_exp = 0;
rack->r_ctl.rc_hpts_flags = 0;
us_cts = tcp_get_usecs(&tv);
/* Now early/late accounting */
if (rack->r_early) {
/*
* We have a early carry over set,
* we can always add more time so we
* can always make this compensation.
*/
slot += rack->r_ctl.rc_agg_early;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
}
if (rack->r_late) {
/*
* This is harder, we can
* compensate some but it
* really depends on what
* the current pacing time is.
*/
if (rack->r_ctl.rc_agg_delayed >= slot) {
/*
* We can't compensate for it all.
* And we have to have some time
* on the clock. We always have a min
* 10 slots (10 x 10 i.e. 100 usecs).
*/
if (slot <= HPTS_TICKS_PER_USEC) {
/* We gain delay */
rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_USEC - slot);
slot = HPTS_TICKS_PER_USEC;
} else {
/* We take off some */
rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_USEC);
slot = HPTS_TICKS_PER_USEC;
}
} else {
slot -= rack->r_ctl.rc_agg_delayed;
rack->r_ctl.rc_agg_delayed = 0;
/* Make sure we have 100 useconds at minimum */
if (slot < HPTS_TICKS_PER_USEC) {
rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_USEC - slot;
slot = HPTS_TICKS_PER_USEC;
}
if (rack->r_ctl.rc_agg_delayed == 0)
rack->r_late = 0;
}
}
if (slot) {
/* We are pacing too */
rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
}
hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
#ifdef NETFLIX_EXP_DETECTION
if (rack->sack_attack_disable &&
(slot < tcp_sad_pacing_interval)) {
/*
* We have a potential attacker on
* the line. We have possibly some
* (or now) pacing time set. We want to
* slow down the processing of sacks by some
* amount (if it is an attacker). Set the default
* slot for attackers in place (unless the orginal
* interval is longer). Its stored in
* micro-seconds, so lets convert to msecs.
*/
slot = tcp_sad_pacing_interval;
}
#endif
if (tp->t_flags & TF_DELACK) {
delayed_ack = TICKS_2_MSEC(tcp_delacktime);
rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
}
if (delayed_ack && ((hpts_timeout == 0) ||
(delayed_ack < hpts_timeout)))
hpts_timeout = delayed_ack;
else
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
/*
* If no timers are going to run and we will fall off the hptsi
* wheel, we resort to a keep-alive timer if its configured.
*/
if ((hpts_timeout == 0) &&
(slot == 0)) {
if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)) {
/*
* Ok we have no timer (persists, rack, tlp, rxt or
* del-ack), we don't have segments being paced. So
* all that is left is the keepalive timer.
*/
if (TCPS_HAVEESTABLISHED(tp->t_state)) {
/* Get the established keep-alive time */
hpts_timeout = TP_KEEPIDLE(tp);
} else {
/* Get the initial setup keep-alive time */
hpts_timeout = TP_KEEPINIT(tp);
}
rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
if (rack->in_probe_rtt) {
/*
* We want to instead not wake up a long time from
* now but to wake up about the time we would
* exit probe-rtt and initiate a keep-alive ack.
* This will get us out of probe-rtt and update
* our min-rtt.
*/
hpts_timeout = (rack_min_probertt_hold / HPTS_USEC_IN_MSEC);
}
}
}
if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
(rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
/*
* RACK, TLP, persists and RXT timers all are restartable
* based on actions input .. i.e we received a packet (ack
* or sack) and that changes things (rw, or snd_una etc).
* Thus we can restart them with a new value. For
* keep-alive, delayed_ack we keep track of what was left
* and restart the timer with a smaller value.
*/
if (left < hpts_timeout)
hpts_timeout = left;
}
if (hpts_timeout) {
/*
* Hack alert for now we can't time-out over 2,147,483
* seconds (a bit more than 596 hours), which is probably ok
* :).
*/
if (hpts_timeout > 0x7ffffffe)
hpts_timeout = 0x7ffffffe;
rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
}
if ((rack->rc_gp_filled == 0) &&
(hpts_timeout < slot) &&
(rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
/*
* We have no good estimate yet for the
* old clunky burst mitigation or the
* real pacing. And the tlp or rxt is smaller
* than the pacing calculation. Lets not
* pace that long since we know the calculation
* so far is not accurate.
*/
slot = hpts_timeout;
}
rack->r_ctl.last_pacing_time = slot;
if (slot) {
rack->r_ctl.rc_last_output_to = us_cts + slot;
if (rack->rc_always_pace || rack->r_mbuf_queue) {
if ((rack->rc_gp_filled == 0) ||
rack->pacing_longer_than_rtt) {
inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
} else {
inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
(rack->r_rr_config != 3))
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
else
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
}
if ((rack->use_rack_rr) &&
(rack->r_rr_config < 2) &&
((hpts_timeout) && ((hpts_timeout * HPTS_USEC_IN_MSEC) < slot))) {
/*
* Arrange for the hpts to kick back in after the
* t-o if the t-o does not cause a send.
*/
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
} else {
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
}
} else if (hpts_timeout) {
if (rack->rc_always_pace || rack->r_mbuf_queue) {
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) {
/* For a rack timer, don't wake us */
inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
if (rack->r_rr_config != 3)
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
else
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
} else {
/* All other timers wake us up */
inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
}
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
} else {
/* No timer starting */
#ifdef INVARIANTS
if (SEQ_GT(tp->snd_max, tp->snd_una)) {
panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
}
#endif
}
rack->rc_tmr_stopped = 0;
if (slot)
rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
}
/*
* RACK Timer, here we simply do logging and house keeping.
* the normal rack_output() function will call the
* appropriate thing to check if we need to do a RACK retransmit.
* We return 1, saying don't proceed with rack_output only
* when all timers have been stopped (destroyed PCB?).
*/
static int
rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
/*
* This timer simply provides an internal trigger to send out data.
* The check_recovery_mode call will see if there are needed
* retransmissions, if so we will enter fast-recovery. The output
* call may or may not do the same thing depending on sysctl
* settings.
*/
struct rack_sendmap *rsm;
int32_t recovery;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
recovery = IN_RECOVERY(tp->t_flags);
counter_u64_add(rack_to_tot, 1);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
rack->rc_on_min_to = 0;
rsm = rack_check_recovery_mode(tp, cts);
rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
if (rsm) {
uint32_t rtt;
rack->r_ctl.rc_resend = rsm;
if (rack->use_rack_rr) {
/*
* Don't accumulate extra pacing delay
* we are allowing the rack timer to
* over-ride pacing i.e. rrr takes precedence
* if the pacing interval is longer than the rrr
* time (in other words we get the min pacing
* time versus rrr pacing time).
*/
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
rtt = rack->rc_rack_rtt;
if (rtt == 0)
rtt = 1;
if (rack->rack_no_prr == 0) {
if ((recovery == 0) &&
(rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) {
/*
* The rack-timeout that enter's us into recovery
* will force out one MSS and set us up so that we
* can do one more send in 2*rtt (transitioning the
* rack timeout into a rack-tlp).
*/
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack->r_timer_override = 1;
rack_log_to_prr(rack, 3, 0);
} else if ((rack->r_ctl.rc_prr_sndcnt < (rsm->r_end - rsm->r_start)) &&
rack->use_rack_rr) {
/*
* When a rack timer goes, if the rack rr is
* on, arrange it so we can send a full segment
* overriding prr (though we pay a price for this
* for future new sends).
*/
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 4, 0);
}
}
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
if (rsm == NULL) {
/* restart a timer and return 1 */
rack_start_hpts_timer(rack, tp, cts,
0, 0, 0);
return (1);
}
return (0);
}
static __inline void
rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
struct rack_sendmap *rsm, uint32_t start)
{
int idx;
nrsm->r_start = start;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_dupack = rsm->r_dupack;
nrsm->usec_orig_send = rsm->usec_orig_send;
nrsm->r_rtr_bytes = 0;
rsm->r_end = nrsm->r_start;
nrsm->r_just_ret = rsm->r_just_ret;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
}
static struct rack_sendmap *
rack_merge_rsm(struct tcp_rack *rack,
struct rack_sendmap *l_rsm,
struct rack_sendmap *r_rsm)
{
/*
* We are merging two ack'd RSM's,
* the l_rsm is on the left (lower seq
* values) and the r_rsm is on the right
* (higher seq value). The simplest way
* to merge these is to move the right
* one into the left. I don't think there
* is any reason we need to try to find
* the oldest (or last oldest retransmitted).
*/
struct rack_sendmap *rm;
l_rsm->r_end = r_rsm->r_end;
if (l_rsm->r_dupack < r_rsm->r_dupack)
l_rsm->r_dupack = r_rsm->r_dupack;
if (r_rsm->r_rtr_bytes)
l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
if (r_rsm->r_in_tmap) {
/* This really should not happen */
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
r_rsm->r_in_tmap = 0;
}
/* Now the flags */
if (r_rsm->r_flags & RACK_HAS_FIN)
l_rsm->r_flags |= RACK_HAS_FIN;
if (r_rsm->r_flags & RACK_TLP)
l_rsm->r_flags |= RACK_TLP;
if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
l_rsm->r_flags |= RACK_RWND_COLLAPSED;
if ((r_rsm->r_flags & RACK_APP_LIMITED) &&
((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
/*
* If both are app-limited then let the
* free lower the count. If right is app
* limited and left is not, transfer.
*/
l_rsm->r_flags |= RACK_APP_LIMITED;
r_rsm->r_flags &= ~RACK_APP_LIMITED;
if (r_rsm == rack->r_ctl.rc_first_appl)
rack->r_ctl.rc_first_appl = l_rsm;
}
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
#ifdef INVARIANTS
if (rm != r_rsm) {
panic("removing head in rack:%p rsm:%p rm:%p",
rack, r_rsm, rm);
}
#endif
if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
/* Transfer the split limit to the map we free */
r_rsm->r_limit_type = l_rsm->r_limit_type;
l_rsm->r_limit_type = 0;
}
rack_free(rack, r_rsm);
return(l_rsm);
}
/*
* TLP Timer, here we simply setup what segment we want to
* have the TLP expire on, the normal rack_output() will then
* send it out.
*
* We return 1, saying don't proceed with rack_output only
* when all timers have been stopped (destroyed PCB?).
*/
static int
rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
/*
* Tail Loss Probe.
*/
struct rack_sendmap *rsm = NULL;
struct rack_sendmap *insret;
struct socket *so;
uint32_t amm, old_prr_snd = 0;
uint32_t out, avail;
int collapsed_win = 0;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
/* Its not time yet */
return (0);
}
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
return (1);
}
/*
* A TLP timer has expired. We have been idle for 2 rtts. So we now
* need to figure out how to force a full MSS segment out.
*/
rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
counter_u64_add(rack_tlp_tot, 1);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
so = tp->t_inpcb->inp_socket;
#ifdef KERN_TLS
if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
/*
* For hardware TLS we do *not* want to send
* new data, lets instead just do a retransmission.
*/
goto need_retran;
}
#endif
avail = sbavail(&so->so_snd);
out = tp->snd_max - tp->snd_una;
if (out > tp->snd_wnd) {
/* special case, we need a retransmission */
collapsed_win = 1;
goto need_retran;
}
/*
* Check our send oldest always settings, and if
* there is an oldest to send jump to the need_retran.
*/
if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
goto need_retran;
if (avail > out) {
/* New data is available */
amm = avail - out;
if (amm > ctf_fixed_maxseg(tp)) {
amm = ctf_fixed_maxseg(tp);
if ((amm + out) > tp->snd_wnd) {
/* We are rwnd limited */
goto need_retran;
}
} else if (amm < ctf_fixed_maxseg(tp)) {
/* not enough to fill a MTU */
goto need_retran;
}
if (IN_RECOVERY(tp->t_flags)) {
/* Unlikely */
if (rack->rack_no_prr == 0) {
old_prr_snd = rack->r_ctl.rc_prr_sndcnt;
if (out + amm <= tp->snd_wnd) {
rack->r_ctl.rc_prr_sndcnt = amm;
rack_log_to_prr(rack, 4, 0);
}
} else
goto need_retran;
} else {
/* Set the send-new override */
if (out + amm <= tp->snd_wnd)
rack->r_ctl.rc_tlp_new_data = amm;
else
goto need_retran;
}
rack->r_ctl.rc_tlpsend = NULL;
counter_u64_add(rack_tlp_newdata, 1);
goto send;
}
need_retran:
/*
* Ok we need to arrange the last un-acked segment to be re-sent, or
* optionally the first un-acked segment.
*/
if (collapsed_win == 0) {
if (rack_always_send_oldest)
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
else {
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
rsm = rack_find_high_nonack(rack, rsm);
}
}
if (rsm == NULL) {
counter_u64_add(rack_tlp_does_nada, 1);
#ifdef TCP_BLACKBOX
tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
#endif
goto out;
}
} else {
/*
* We must find the last segment
* that was acceptable by the client.
*/
RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
/* Found one */
break;
}
}
if (rsm == NULL) {
/* None? if so send the first */
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm == NULL) {
counter_u64_add(rack_tlp_does_nada, 1);
#ifdef TCP_BLACKBOX
tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
#endif
goto out;
}
}
}
if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
/*
* We need to split this the last segment in two.
*/
struct rack_sendmap *nrsm;
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
/*
* No memory to split, we will just exit and punt
* off to the RXT timer.
*/
counter_u64_add(rack_tlp_does_nada, 1);
goto out;
}
rack_clone_rsm(rack, nrsm, rsm,
(rsm->r_end - ctf_fixed_maxseg(tp)));
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
rsm = nrsm;
}
rack->r_ctl.rc_tlpsend = rsm;
send:
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
return (0);
out:
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
return (0);
}
/*
* Delayed ack Timer, here we simply need to setup the
* ACK_NOW flag and remove the DELACK flag. From there
* the output routine will send the ack out.
*
* We only return 1, saying don't proceed, if all timers
* are stopped (destroyed PCB?).
*/
static int
rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
KMOD_TCPSTAT_INC(tcps_delack);
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
return (0);
}
/*
* Persists timer, here we simply send the
* same thing as a keepalive will.
* the one byte send.
*
* We only return 1, saying don't proceed, if all timers
* are stopped (destroyed PCB?).
*/
static int
rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
struct tcptemp *t_template;
struct inpcb *inp;
int32_t retval = 1;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (rack->rc_in_persist == 0)
return (0);
if (ctf_progress_timeout_check(tp, false)) {
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(inp, ETIMEDOUT);
return (1);
}
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
/*
* Persistence timer into zero window. Force a byte to be output, if
* possible.
*/
KMOD_TCPSTAT_INC(tcps_persisttimeo);
/*
* Hack: if the peer is dead/unreachable, we do not time out if the
* window is closed. After a full backoff, drop the connection if
* the idle time (no responses to probes) reaches the maximum
* backoff that we would use if retransmitting.
*/
if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
(ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
KMOD_TCPSTAT_INC(tcps_persistdrop);
retval = 1;
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
goto out;
}
if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
tp->snd_una == tp->snd_max)
rack_exit_persist(tp, rack, cts);
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
/*
* If the user has closed the socket then drop a persisting
* connection after a much reduced timeout.
*/
if (tp->t_state > TCPS_CLOSE_WAIT &&
(ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
retval = 1;
KMOD_TCPSTAT_INC(tcps_persistdrop);
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
goto out;
}
t_template = tcpip_maketemplate(rack->rc_inp);
if (t_template) {
/* only set it if we were answered */
if (rack->forced_ack == 0) {
rack->forced_ack = 1;
rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
}
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
tp->rcv_nxt, tp->snd_una - 1, 0);
/* This sends an ack */
if (tp->t_flags & TF_DELACK)
tp->t_flags &= ~TF_DELACK;
free(t_template, M_TEMP);
}
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
out:
rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
rack_start_hpts_timer(rack, tp, cts,
0, 0, 0);
return (retval);
}
/*
* If a keepalive goes off, we had no other timers
* happening. We always return 1 here since this
* routine either drops the connection or sends
* out a segment with respond.
*/
static int
rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
struct tcptemp *t_template;
struct inpcb *inp;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
inp = tp->t_inpcb;
rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
/*
* Keep-alive timer went off; send something or drop connection if
* idle for too long.
*/
KMOD_TCPSTAT_INC(tcps_keeptimeo);
if (tp->t_state < TCPS_ESTABLISHED)
goto dropit;
if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
tp->t_state <= TCPS_CLOSING) {
if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
goto dropit;
/*
* Send a packet designed to force a response if the peer is
* up and reachable: either an ACK if the connection is
* still alive, or an RST if the peer has closed the
* connection due to timeout or reboot. Using sequence
* number tp->snd_una-1 causes the transmitted zero-length
* segment to lie outside the receive window; by the
* protocol spec, this requires the correspondent TCP to
* respond.
*/
KMOD_TCPSTAT_INC(tcps_keepprobe);
t_template = tcpip_maketemplate(inp);
if (t_template) {
if (rack->forced_ack == 0) {
rack->forced_ack = 1;
rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
}
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
tp->rcv_nxt, tp->snd_una - 1, 0);
free(t_template, M_TEMP);
}
}
rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
return (1);
dropit:
KMOD_TCPSTAT_INC(tcps_keepdrops);
tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
return (1);
}
/*
* Retransmit helper function, clear up all the ack
* flags and take care of important book keeping.
*/
static void
rack_remxt_tmr(struct tcpcb *tp)
{
/*
* The retransmit timer went off, all sack'd blocks must be
* un-acked.
*/
struct rack_sendmap *rsm, *trsm = NULL;
struct tcp_rack *rack;
int32_t cnt = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack_timer_cancel(tp, rack, tcp_ts_getticks(), __LINE__);
rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
/*
* Ideally we would like to be able to
* mark SACK-PASS on anything not acked here.
* However, if we do that we would burst out
* all that data 1ms apart. This would be unwise,
* so for now we will just let the normal rxt timer
* and tlp timer take care of it.
*/
RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if (rsm->r_flags & RACK_ACKED) {
cnt++;
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
if (rsm->r_in_tmap == 0) {
/* We must re-add it back to the tlist */
if (trsm == NULL) {
TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
} else {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
}
rsm->r_in_tmap = 1;
}
}
trsm = rsm;
if (rsm->r_flags & RACK_ACKED)
rsm->r_flags |= RACK_WAS_ACKED;
rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
}
/* Clear the count (we just un-acked them) */
rack->r_ctl.rc_sacked = 0;
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
rack->r_late = 0;
/* Clear the tlp rtx mark */
rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 6, 0);
rack->r_timer_override = 1;
}
static void
rack_cc_conn_init(struct tcpcb *tp)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
cc_conn_init(tp);
/*
* We want a chance to stay in slowstart as
* we create a connection. TCP spec says that
* initially ssthresh is infinite. For our
* purposes that is the snd_wnd.
*/
if (tp->snd_ssthresh < tp->snd_wnd) {
tp->snd_ssthresh = tp->snd_wnd;
}
/*
* We also want to assure a IW worth of
* data can get inflight.
*/
if (rc_init_window(rack) < tp->snd_cwnd)
tp->snd_cwnd = rc_init_window(rack);
}
/*
* Re-transmit timeout! If we drop the PCB we will return 1, otherwise
* we will setup to retransmit the lowest seq number outstanding.
*/
static int
rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
int32_t rexmt;
struct inpcb *inp;
int32_t retval = 0;
bool isipv6;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (ctf_progress_timeout_check(tp, false)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(inp, ETIMEDOUT);
return (1);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_una == tp->snd_max)) {
/* Nothing outstanding .. nothing to do */
return (0);
}
/*
* Retransmission timer went off. Message has not been acked within
* retransmit interval. Back off to a longer retransmit interval
* and retransmit one segment.
*/
rack_remxt_tmr(tp);
if ((rack->r_ctl.rc_resend == NULL) ||
((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
/*
* If the rwnd collapsed on
* the one we are retransmitting
* it does not count against the
* rxt count.
*/
tp->t_rxtshift++;
}
if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
KMOD_TCPSTAT_INC(tcps_timeoutdrop);
retval = 1;
tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
tcp_set_inp_to_drop(rack->rc_inp,
(tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
goto out;
}
if (tp->t_state == TCPS_SYN_SENT) {
/*
* If the SYN was retransmitted, indicate CWND to be limited
* to 1 segment in cc_conn_init().
*/
tp->snd_cwnd = 1;
} else if (tp->t_rxtshift == 1) {
/*
* first retransmit; record ssthresh and cwnd so they can be
* recovered if this turns out to be a "bad" retransmit. A
* retransmit is considered "bad" if an ACK for this segment
* is received within RTT/2 interval; the assumption here is
* that the ACK was already in flight. See "On Estimating
* End-to-End Network Path Properties" by Allman and Paxson
* for more details.
*/
tp->snd_cwnd_prev = tp->snd_cwnd;
tp->snd_ssthresh_prev = tp->snd_ssthresh;
tp->snd_recover_prev = tp->snd_recover;
if (IN_FASTRECOVERY(tp->t_flags))
tp->t_flags |= TF_WASFRECOVERY;
else
tp->t_flags &= ~TF_WASFRECOVERY;
if (IN_CONGRECOVERY(tp->t_flags))
tp->t_flags |= TF_WASCRECOVERY;
else
tp->t_flags &= ~TF_WASCRECOVERY;
tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
tp->t_flags |= TF_PREVVALID;
} else
tp->t_flags &= ~TF_PREVVALID;
KMOD_TCPSTAT_INC(tcps_rexmttimeo);
if ((tp->t_state == TCPS_SYN_SENT) ||
(tp->t_state == TCPS_SYN_RECEIVED))
rexmt = MSEC_2_TICKS(RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift]);
else
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
TCPT_RANGESET(tp->t_rxtcur, rexmt,
max(MSEC_2_TICKS(rack_rto_min), rexmt),
MSEC_2_TICKS(rack_rto_max));
/*
* We enter the path for PLMTUD if connection is established or, if
* connection is FIN_WAIT_1 status, reason for the last is that if
* amount of data we send is very small, we could send it in couple
* of packets and process straight to FIN. In that case we won't
* catch ESTABLISHED state.
*/
#ifdef INET6
isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
#else
isipv6 = false;
#endif
if (((V_tcp_pmtud_blackhole_detect == 1) ||
(V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
(V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
((tp->t_state == TCPS_ESTABLISHED) ||
(tp->t_state == TCPS_FIN_WAIT_1))) {
/*
* Idea here is that at each stage of mtu probe (usually,
* 1448 -> 1188 -> 524) should be given 2 chances to recover
* before further clamping down. 'tp->t_rxtshift % 2 == 0'
* should take care of that.
*/
if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
(TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
(tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
tp->t_rxtshift % 2 == 0)) {
/*
* Enter Path MTU Black-hole Detection mechanism: -
* Disable Path MTU Discovery (IP "DF" bit). -
* Reduce MTU to lower value than what we negotiated
* with peer.
*/
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
/* Record that we may have found a black hole. */
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
/* Keep track of previous MSS. */
tp->t_pmtud_saved_maxseg = tp->t_maxseg;
}
/*
* Reduce the MSS to blackhole value or to the
* default in an attempt to retransmit.
*/
#ifdef INET6
if (isipv6 &&
tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
/* Use the sysctl tuneable blackhole MSS. */
tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
} else if (isipv6) {
/* Use the default MSS. */
tp->t_maxseg = V_tcp_v6mssdflt;
/*
* Disable Path MTU Discovery when we switch
* to minmss.
*/
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
/* Use the sysctl tuneable blackhole MSS. */
tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
} else {
/* Use the default MSS. */
tp->t_maxseg = V_tcp_mssdflt;
/*
* Disable Path MTU Discovery when we switch
* to minmss.
*/
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
}
#endif
} else {
/*
* If further retransmissions are still unsuccessful
* with a lowered MTU, maybe this isn't a blackhole
* and we restore the previous MSS and blackhole
* detection flags. The limit '6' is determined by
* giving each probe stage (1448, 1188, 524) 2
* chances to recover.
*/
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
(tp->t_rxtshift >= 6)) {
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
tp->t_maxseg = tp->t_pmtud_saved_maxseg;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
}
}
}
/*
* If we backed off this far, our srtt estimate is probably bogus.
* Clobber it so we'll take the next rtt measurement as our srtt;
* move the current srtt into rttvar to keep the current retransmit
* times until then.
*/
if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
#ifdef INET6
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
in6_losing(tp->t_inpcb);
else
#endif
in_losing(tp->t_inpcb);
tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
tp->t_srtt = 0;
}
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
tp->snd_recover = tp->snd_max;
tp->t_flags |= TF_ACKNOW;
tp->t_rtttime = 0;
rack_cong_signal(tp, NULL, CC_RTO);
out:
return (retval);
}
static int
rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling)
{
int32_t ret = 0;
int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
if (timers == 0) {
return (0);
}
if (tp->t_state == TCPS_LISTEN) {
/* no timers on listen sockets */
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
return (0);
return (1);
}
if ((timers & PACE_TMR_RACK) &&
rack->rc_on_min_to) {
/*
* For the rack timer when we
* are on a min-timeout (which means rrr_conf = 3)
* we don't want to check the timer. It may
* be going off for a pace and thats ok we
* want to send the retransmit (if its ready).
*
* If its on a normal rack timer (non-min) then
* we will check if its expired.
*/
goto skip_time_check;
}
if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
uint32_t left;
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
ret = -1;
rack_log_to_processing(rack, cts, ret, 0);
return (0);
}
if (hpts_calling == 0) {
/*
* A user send or queued mbuf (sack) has called us? We
* return 0 and let the pacing guards
* deal with it if they should or
* should not cause a send.
*/
ret = -2;
rack_log_to_processing(rack, cts, ret, 0);
return (0);
}
/*
* Ok our timer went off early and we are not paced false
* alarm, go back to sleep.
*/
ret = -3;
left = rack->r_ctl.rc_timer_exp - cts;
tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
rack_log_to_processing(rack, cts, ret, left);
return (1);
}
skip_time_check:
rack->rc_tmr_stopped = 0;
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
if (timers & PACE_TMR_DELACK) {
ret = rack_timeout_delack(tp, rack, cts);
} else if (timers & PACE_TMR_RACK) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_rack(tp, rack, cts);
} else if (timers & PACE_TMR_TLP) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_tlp(tp, rack, cts);
} else if (timers & PACE_TMR_RXT) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_rxt(tp, rack, cts);
} else if (timers & PACE_TMR_PERSIT) {
ret = rack_timeout_persist(tp, rack, cts);
} else if (timers & PACE_TMR_KEEP) {
ret = rack_timeout_keepalive(tp, rack, cts);
}
rack_log_to_processing(rack, cts, ret, timers);
return (ret);
}
static void
rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
{
struct timeval tv;
uint32_t us_cts, flags_on_entry;
uint8_t hpts_removed = 0;
flags_on_entry = rack->r_ctl.rc_hpts_flags;
us_cts = tcp_get_usecs(&tv);
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
((tp->snd_max - tp->snd_una) == 0))) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
hpts_removed = 1;
/* If we were not delayed cancel out the flag. */
if ((tp->snd_max - tp->snd_una) == 0)
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
}
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
if (rack->rc_inp->inp_in_hpts &&
((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
/*
* Canceling timer's when we have no output being
* paced. We also must remove ourselves from the
* hpts.
*/
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
hpts_removed = 1;
}
rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
}
if (hpts_removed == 0)
rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
}
static void
rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
{
return;
}
static int
rack_stopall(struct tcpcb *tp)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack->t_timers_stopped = 1;
return (0);
}
static void
rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
{
return;
}
static int
rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
{
return (0);
}
static void
rack_stop_all_timers(struct tcpcb *tp)
{
struct tcp_rack *rack;
/*
* Assure no timers are running.
*/
if (tcp_timer_active(tp, TT_PERSIST)) {
/* We enter in persists, set the flag appropriately */
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack->rc_in_persist = 1;
}
tcp_timer_suspend(tp, TT_PERSIST);
tcp_timer_suspend(tp, TT_REXMT);
tcp_timer_suspend(tp, TT_KEEP);
tcp_timer_suspend(tp, TT_DELACK);
}
static void
rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts)
{
int32_t idx;
rsm->r_rtr_cnt++;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
rsm->r_dupack = 0;
if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
rsm->r_flags |= RACK_OVERMAX;
}
if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
}
idx = rsm->r_rtr_cnt - 1;
rsm->r_tim_lastsent[idx] = ts;
if (rsm->r_flags & RACK_ACKED) {
/* Problably MTU discovery messing with us */
rsm->r_flags &= ~RACK_ACKED;
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
}
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
if (rsm->r_flags & RACK_SACK_PASSED) {
/* We have retransmitted due to the SACK pass */
rsm->r_flags &= ~RACK_SACK_PASSED;
rsm->r_flags |= RACK_WAS_SACKPASS;
}
}
static uint32_t
rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts, int32_t *lenp)
{
/*
* We (re-)transmitted starting at rsm->r_start for some length
* (possibly less than r_end.
*/
struct rack_sendmap *nrsm, *insret;
uint32_t c_end;
int32_t len;
len = *lenp;
c_end = rsm->r_start + len;
if (SEQ_GEQ(c_end, rsm->r_end)) {
/*
* We retransmitted the whole piece or more than the whole
* slopping into the next rsm.
*/
rack_update_rsm(tp, rack, rsm, ts);
if (c_end == rsm->r_end) {
*lenp = 0;
return (0);
} else {
int32_t act_len;
/* Hangs over the end return whats left */
act_len = rsm->r_end - rsm->r_start;
*lenp = (len - act_len);
return (rsm->r_end);
}
/* We don't get out of this block. */
}
/*
* Here we retransmitted less than the whole thing which means we
* have to split this into what was transmitted and what was not.
*/
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
/*
* We can't get memory, so lets not proceed.
*/
*lenp = 0;
return (0);
}
/*
* So here we are going to take the original rsm and make it what we
* retransmitted. nrsm will be the tail portion we did not
* retransmit. For example say the chunk was 1, 11 (10 bytes). And
* we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
* 1, 6 and the new piece will be 6, 11.
*/
rack_clone_rsm(rack, nrsm, rsm, c_end);
nrsm->r_dupack = 0;
rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
rack_update_rsm(tp, rack, rsm, ts);
*lenp = 0;
return (0);
}
static void
rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
uint8_t pass, struct rack_sendmap *hintrsm, uint32_t us_cts)
{
struct tcp_rack *rack;
struct rack_sendmap *rsm, *nrsm, *insret, fe;
register uint32_t snd_max, snd_una;
/*
* Add to the RACK log of packets in flight or retransmitted. If
* there is a TS option we will use the TS echoed, if not we will
* grab a TS.
*
* Retransmissions will increment the count and move the ts to its
* proper place. Note that if options do not include TS's then we
* won't be able to effectively use the ACK for an RTT on a retran.
*
* Notes about r_start and r_end. Lets consider a send starting at
* sequence 1 for 10 bytes. In such an example the r_start would be
* 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
* This means that r_end is actually the first sequence for the next
* slot (11).
*
*/
/*
* If err is set what do we do XXXrrs? should we not add the thing?
* -- i.e. return if err != 0 or should we pretend we sent it? --
* i.e. proceed with add ** do this for now.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
if (err)
/*
* We don't log errors -- we could but snd_max does not
* advance in this case either.
*/
return;
if (th_flags & TH_RST) {
/*
* We don't log resets and we return immediately from
* sending
*/
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
snd_una = tp->snd_una;
if (SEQ_LEQ((seq_out + len), snd_una)) {
/* Are sending an old segment to induce an ack (keep-alive)? */
return;
}
if (SEQ_LT(seq_out, snd_una)) {
/* huh? should we panic? */
uint32_t end;
end = seq_out + len;
seq_out = snd_una;
if (SEQ_GEQ(end, seq_out))
len = end - seq_out;
else
len = 0;
}
snd_max = tp->snd_max;
if (th_flags & (TH_SYN | TH_FIN)) {
/*
* The call to rack_log_output is made before bumping
* snd_max. This means we can record one extra byte on a SYN
* or FIN if seq_out is adding more on and a FIN is present
* (and we are not resending).
*/
if ((th_flags & TH_SYN) && (seq_out == tp->iss))
len++;
if (th_flags & TH_FIN)
len++;
if (SEQ_LT(snd_max, tp->snd_nxt)) {
/*
* The add/update as not been done for the FIN/SYN
* yet.
*/
snd_max = tp->snd_nxt;
}
}
if (len == 0) {
/* We don't log zero window probes */
return;
}
rack->r_ctl.rc_time_last_sent = ts;
if (IN_RECOVERY(tp->t_flags)) {
rack->r_ctl.rc_prr_out += len;
}
/* First question is it a retransmission or new? */
if (seq_out == snd_max) {
/* Its new */
again:
rsm = rack_alloc(rack);
if (rsm == NULL) {
/*
* Hmm out of memory and the tcb got destroyed while
* we tried to wait.
*/
return;
}
if (th_flags & TH_FIN) {
rsm->r_flags = RACK_HAS_FIN;
} else {
rsm->r_flags = 0;
}
rsm->r_tim_lastsent[0] = ts;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->usec_orig_send = us_cts;
if (th_flags & TH_SYN) {
/* The data space is one beyond snd_una */
rsm->r_flags |= RACK_HAS_SIN;
rsm->r_start = seq_out + 1;
rsm->r_end = rsm->r_start + (len - 1);
} else {
/* Normal case */
rsm->r_start = seq_out;
rsm->r_end = rsm->r_start + len;
}
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
/*
* Special case detection, is there just a single
* packet outstanding when we are not in recovery?
*
* If this is true mark it so.
*/
if ((IN_RECOVERY(tp->t_flags) == 0) &&
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
struct rack_sendmap *prsm;
prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (prsm)
prsm->r_one_out_nr = 1;
}
return;
}
/*
* If we reach here its a retransmission and we need to find it.
*/
memset(&fe, 0, sizeof(fe));
more:
if (hintrsm && (hintrsm->r_start == seq_out)) {
rsm = hintrsm;
hintrsm = NULL;
} else {
/* No hints sorry */
rsm = NULL;
}
if ((rsm) && (rsm->r_start == seq_out)) {
seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
if (len == 0) {
return;
} else {
goto more;
}
}
/* Ok it was not the last pointer go through it the hard way. */
refind:
fe.r_start = seq_out;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm) {
if (rsm->r_start == seq_out) {
seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
if (len == 0) {
return;
} else {
goto refind;
}
}
if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
/* Transmitted within this piece */
/*
* Ok we must split off the front and then let the
* update do the rest
*/
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
rack_update_rsm(tp, rack, rsm, ts);
return;
}
/*
* copy rsm to nrsm and then trim the front of rsm
* to not include this part.
*/
rack_clone_rsm(rack, nrsm, rsm, seq_out);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
seq_out = rack_update_entry(tp, rack, nrsm, ts, &len);
if (len == 0) {
return;
} else if (len > 0)
goto refind;
}
}
/*
* Hmm not found in map did they retransmit both old and on into the
* new?
*/
if (seq_out == tp->snd_max) {
goto again;
} else if (SEQ_LT(seq_out, tp->snd_max)) {
#ifdef INVARIANTS
printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
seq_out, len, tp->snd_una, tp->snd_max);
printf("Starting Dump of all rack entries\n");
RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
printf("rsm:%p start:%u end:%u\n",
rsm, rsm->r_start, rsm->r_end);
}
printf("Dump complete\n");
panic("seq_out not found rack:%p tp:%p",
rack, tp);
#endif
} else {
#ifdef INVARIANTS
/*
* Hmm beyond sndmax? (only if we are using the new rtt-pack
* flag)
*/
panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
seq_out, len, tp->snd_max, tp);
#endif
}
}
/*
* Record one of the RTT updates from an ack into
* our sample structure.
*/
static void
tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
{
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
}
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
}
if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
rack->r_ctl.rc_gp_lowrtt = us_rtt;
if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
}
if ((confidence == 1) &&
((rsm == NULL) ||
(rsm->r_just_ret) ||
(rsm->r_one_out_nr &&
len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
/*
* If the rsm had a just return
* hit it then we can't trust the
* rtt measurement for buffer deterimination
* Note that a confidence of 2, indicates
* SACK'd which overrides the r_just_ret or
* the r_one_out_nr. If it was a CUM-ACK and
* we had only two outstanding, but get an
* ack for only 1. Then that also lowers our
* confidence.
*/
confidence = 0;
}
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
if (rack->r_ctl.rack_rs.confidence == 0) {
/*
* We take anything with no current confidence
* saved.
*/
rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
rack->r_ctl.rack_rs.confidence = confidence;
rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
} else if (confidence || rack->r_ctl.rack_rs.confidence) {
/*
* Once we have a confident number,
* we can update it with a smaller
* value since this confident number
* may include the DSACK time until
* the next segment (the second one) arrived.
*/
rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
rack->r_ctl.rack_rs.confidence = confidence;
rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
}
}
rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
rack->r_ctl.rack_rs.rs_rtt_cnt++;
}
/*
* Collect new round-trip time estimate
* and update averages and current timeout.
*/
static void
tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
{
int32_t delta;
uint32_t o_srtt, o_var;
int32_t hrtt_up = 0;
int32_t rtt;
if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
/* No valid sample */
return;
if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
/* We are to use the lowest RTT seen in a single ack */
rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
/* We are to use the highest RTT seen in a single ack */
rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
/* We are to use the average RTT seen in a single ack */
rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
} else {
#ifdef INVARIANTS
panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
#endif
return;
}
if (rtt == 0)
rtt = 1;
if (rack->rc_gp_rtt_set == 0) {
/*
* With no RTT we have to accept
* even one we are not confident of.
*/
rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
rack->rc_gp_rtt_set = 1;
} else if (rack->r_ctl.rack_rs.confidence) {
/* update the running gp srtt */
rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
}
if (rack->r_ctl.rack_rs.confidence) {
/*
* record the low and high for highly buffered path computation,
* we only do this if we are confident (not a retransmission).
*/
if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
hrtt_up = 1;
}
if (rack->rc_highly_buffered == 0) {
/*
* Currently once we declare a path has
* highly buffered there is no going
* back, which may be a problem...
*/
if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
rack->r_ctl.rc_highest_us_rtt,
rack->r_ctl.rc_lowest_us_rtt,
RACK_RTTS_SEEHBP);
rack->rc_highly_buffered = 1;
}
}
}
if ((rack->r_ctl.rack_rs.confidence) ||
(rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
/*
* If we are highly confident of it <or> it was
* never retransmitted we accept it as the last us_rtt.
*/
rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
/* The lowest rtt can be set if its was not retransmited */
if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
if (rack->r_ctl.rc_lowest_us_rtt == 0)
rack->r_ctl.rc_lowest_us_rtt = 1;
}
}
rack_log_rtt_sample(rack, rtt);
o_srtt = tp->t_srtt;
o_var = tp->t_rttvar;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (tp->t_srtt != 0) {
/*
* srtt is stored as fixed point with 5 bits after the
* binary point (i.e., scaled by 8). The following magic is
* equivalent to the smoothing algorithm in rfc793 with an
* alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
* Adjust rtt to origin 0.
*/
delta = ((rtt - 1) << TCP_DELTA_SHIFT)
- (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
tp->t_srtt += delta;
if (tp->t_srtt <= 0)
tp->t_srtt = 1;
/*
* We accumulate a smoothed rtt variance (actually, a
* smoothed mean difference), then set the retransmit timer
* to smoothed rtt + 4 times the smoothed variance. rttvar
* is stored as fixed point with 4 bits after the binary
* point (scaled by 16). The following is equivalent to
* rfc793 smoothing with an alpha of .75 (rttvar =
* rttvar*3/4 + |delta| / 4). This replaces rfc793's
* wired-in beta.
*/
if (delta < 0)
delta = -delta;
delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
tp->t_rttvar += delta;
if (tp->t_rttvar <= 0)
tp->t_rttvar = 1;
if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
} else {
/*
* No rtt measurement yet - use the unsmoothed rtt. Set the
* variance to half the rtt (so our first retransmit happens
* at 3*rtt).
*/
tp->t_srtt = rtt << TCP_RTT_SHIFT;
tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
}
KMOD_TCPSTAT_INC(tcps_rttupdated);
tp->t_rttupdated++;
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
#endif
tp->t_rxtshift = 0;
/*
* the retransmit should happen at rtt + 4 * rttvar. Because of the
* way we do the smoothing, srtt and rttvar will each average +1/2
* tick of bias. When we compute the retransmit timer, we want 1/2
* tick of rounding and 1 extra tick because of +-1/2 tick
* uncertainty in the firing of the timer. The bias will give us
* exactly the 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below the minimum
* feasible timer (which is 2 ticks).
*/
TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
max(MSEC_2_TICKS(rack_rto_min), rtt + 2), MSEC_2_TICKS(rack_rto_max));
tp->t_softerror = 0;
}
static void
rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
uint32_t t, uint32_t cts)
{
/*
* For this RSM, we acknowledged the data from a previous
* transmission, not the last one we made. This means we did a false
* retransmit.
*/
struct tcp_rack *rack;
if (rsm->r_flags & RACK_HAS_FIN) {
/*
* The sending of the FIN often is multiple sent when we
* have everything outstanding ack'd. We ignore this case
* since its over now.
*/
return;
}
if (rsm->r_flags & RACK_TLP) {
/*
* We expect TLP's to have this occur.
*/
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
/* should we undo cc changes and exit recovery? */
if (IN_RECOVERY(tp->t_flags)) {
if (rack->r_ctl.rc_rsm_start == rsm->r_start) {
/*
* Undo what we ratched down and exit recovery if
* possible
*/
EXIT_RECOVERY(tp->t_flags);
tp->snd_recover = tp->snd_una;
if (rack->r_ctl.rc_cwnd_at > tp->snd_cwnd)
tp->snd_cwnd = rack->r_ctl.rc_cwnd_at;
if (rack->r_ctl.rc_ssthresh_at > tp->snd_ssthresh)
tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at;
}
}
if (rsm->r_flags & RACK_WAS_SACKPASS) {
/*
* We retransmitted based on a sack and the earlier
* retransmission ack'd it - re-ordering is occuring.
*/
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
counter_u64_add(rack_badfr, 1);
counter_u64_add(rack_badfr_bytes, (rsm->r_end - rsm->r_start));
}
static void
rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
{
/*
* Apply to filter the inbound us-rtt at us_cts.
*/
uint32_t old_rtt;
old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
us_rtt, us_cts);
if (rack->r_ctl.last_pacing_time &&
rack->rc_gp_dyn_mul &&
(rack->r_ctl.last_pacing_time > us_rtt))
rack->pacing_longer_than_rtt = 1;
else
rack->pacing_longer_than_rtt = 0;
if (old_rtt > us_rtt) {
/* We just hit a new lower rtt time */
rack_log_rtt_shrinks(rack, us_cts, old_rtt,
__LINE__, RACK_RTTS_NEWRTT);
/*
* Only count it if its lower than what we saw within our
* calculated range.
*/
if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
if (rack_probertt_lower_within &&
rack->rc_gp_dyn_mul &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/*
* We are seeing a new lower rtt very close
* to the time that we would have entered probe-rtt.
* This is probably due to the fact that a peer flow
* has entered probe-rtt. Lets go in now too.
*/
uint32_t val;
val = rack_probertt_lower_within * rack_time_between_probertt;
val /= 100;
if ((rack->in_probe_rtt == 0) &&
((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val))) {
rack_enter_probertt(rack, us_cts);
}
}
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
}
}
}
static int
rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
{
int32_t i;
uint32_t t, len_acked;
if ((rsm->r_flags & RACK_ACKED) ||
(rsm->r_flags & RACK_WAS_ACKED))
/* Already done */
return (0);
if (ack_type == CUM_ACKED) {
if (SEQ_GT(th_ack, rsm->r_end))
len_acked = rsm->r_end - rsm->r_start;
else
len_acked = th_ack - rsm->r_start;
} else
len_acked = rsm->r_end - rsm->r_start;
if (rsm->r_rtr_cnt == 1) {
uint32_t us_rtt;
t = cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
if ((int)t <= 0)
t = 1;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
if (!rack->r_ctl.rc_rack_min_rtt ||
SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - rsm->usec_orig_send;
if (us_rtt == 0)
us_rtt = 1;
rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
if (ack_type == SACKED)
tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
else {
/*
* For cum-ack we are only confident if what
* is being acked is included in a measurement.
* Otherwise it could be an idle period that
* includes Delayed-ack time.
*/
tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
(rack->app_limited_needs_set ? 0 : 1), rsm, rsm->r_rtr_cnt);
}
if ((rsm->r_flags & RACK_TLP) &&
(!IN_RECOVERY(tp->t_flags))) {
/* Segment was a TLP and our retrans matched */
if (rack->r_ctl.rc_tlp_cwnd_reduce) {
rack->r_ctl.rc_rsm_start = tp->snd_max;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure
* we send one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 7, 0);
}
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
rack->rc_rack_rtt = t;
}
return (1);
}
/*
* We clear the soft/rxtshift since we got an ack.
* There is no assurance we will call the commit() function
* so we need to clear these to avoid incorrect handling.
*/
tp->t_rxtshift = 0;
tp->t_softerror = 0;
if ((to->to_flags & TOF_TS) &&
(ack_type == CUM_ACKED) &&
(to->to_tsecr) &&
((rsm->r_flags & RACK_OVERMAX) == 0)) {
/*
* Now which timestamp does it match? In this block the ACK
* must be coming from a previous transmission.
*/
for (i = 0; i < rsm->r_rtr_cnt; i++) {
if (rsm->r_tim_lastsent[i] == to->to_tsecr) {
t = cts - rsm->r_tim_lastsent[i];
if ((int)t <= 0)
t = 1;
if ((i + 1) < rsm->r_rtr_cnt) {
/* Likely */
rack_earlier_retran(tp, rsm, t, cts);
}
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
rack->rc_rack_rtt = t;
}
tcp_rack_xmit_timer(rack, t + 1, len_acked, (t * HPTS_USEC_IN_MSEC), 0, rsm,
rsm->r_rtr_cnt);
return (1);
}
}
goto ts_not_found;
} else {
/*
* Ok its a SACK block that we retransmitted. or a windows
* machine without timestamps. We can tell nothing from the
* time-stamp since its not there or the time the peer last
* recieved a segment that moved forward its cum-ack point.
*/
ts_not_found:
i = rsm->r_rtr_cnt - 1;
t = cts - rsm->r_tim_lastsent[i];
if ((int)t <= 0)
t = 1;
if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
/*
* We retransmitted and the ack came back in less
* than the smallest rtt we have observed. We most
* likey did an improper retransmit as outlined in
* 4.2 Step 3 point 2 in the rack-draft.
*/
i = rsm->r_rtr_cnt - 2;
t = cts - rsm->r_tim_lastsent[i];
rack_earlier_retran(tp, rsm, t, cts);
} else if (rack->r_ctl.rc_rack_min_rtt) {
/*
* We retransmitted it and the retransmit did the
* job.
*/
if (!rack->r_ctl.rc_rack_min_rtt ||
SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[i])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[i];
rack->rc_rack_rtt = t;
}
return (1);
}
}
return (0);
}
/*
* Mark the SACK_PASSED flag on all entries prior to rsm send wise.
*/
static void
rack_log_sack_passed(struct tcpcb *tp,
struct tcp_rack *rack, struct rack_sendmap *rsm)
{
struct rack_sendmap *nrsm;
nrsm = rsm;
TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
rack_head, r_tnext) {
if (nrsm == rsm) {
/* Skip orginal segment he is acked */
continue;
}
if (nrsm->r_flags & RACK_ACKED) {
/*
* Skip ack'd segments, though we
* should not see these, since tmap
* should not have ack'd segments.
*/
continue;
}
if (nrsm->r_flags & RACK_SACK_PASSED) {
/*
* We found one that is already marked
* passed, we have been here before and
* so all others below this are marked.
*/
break;
}
nrsm->r_flags |= RACK_SACK_PASSED;
nrsm->r_flags &= ~RACK_WAS_SACKPASS;
}
}
static void
rack_need_set_test(struct tcpcb *tp,
struct tcp_rack *rack,
struct rack_sendmap *rsm,
tcp_seq th_ack,
int line,
int use_which)
{
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
/*
* We were app limited, and this ack
* butts up or goes beyond the point where we want
* to start our next measurement. We need
* to record the new gput_ts as here and
* possibly update the start sequence.
*/
uint32_t seq, ts;
if (rsm->r_rtr_cnt > 1) {
/*
* This is a retransmit, can we
* really make any assessment at this
* point? We are not really sure of
* the timestamp, is it this or the
* previous transmission?
*
* Lets wait for something better that
* is not retransmitted.
*/
return;
}
seq = tp->gput_seq;
ts = tp->gput_ts;
rack->app_limited_needs_set = 0;
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
/* Do we start at a new end? */
if ((use_which == RACK_USE_BEG) &&
SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
/*
* When we get an ACK that just eats
* up some of the rsm, we set RACK_USE_BEG
* since whats at r_start (i.e. th_ack)
* is left unacked and thats where the
* measurement not starts.
*/
tp->gput_seq = rsm->r_start;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if ((use_which == RACK_USE_END) &&
SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
/*
* We use the end when the cumack
* is moving forward and completely
* deleting the rsm passed so basically
* r_end holds th_ack.
*
* For SACK's we also want to use the end
* since this piece just got sacked and
* we want to target anything after that
* in our measurement.
*/
tp->gput_seq = rsm->r_end;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if (use_which == RACK_USE_END_OR_THACK) {
/*
* special case for ack moving forward,
* not a sack, we need to move all the
* way up to where this ack cum-ack moves
* to.
*/
if (SEQ_GT(th_ack, rsm->r_end))
tp->gput_seq = th_ack;
else
tp->gput_seq = rsm->r_end;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
/*
* We moved beyond this guy's range, re-calculate
* the new end point.
*/
if (rack->rc_gp_filled == 0) {
tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
} else {
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
}
}
/*
* We are moving the goal post, we may be able to clear the
* measure_saw_probe_rtt flag.
*/
if ((rack->in_probe_rtt == 0) &&
(rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
seq, tp->gput_seq, 0, 5, line, NULL);
if (rack->rc_gp_filled &&
((tp->gput_ack - tp->gput_seq) <
max(rc_init_window(rack), (MIN_GP_WIN *
ctf_fixed_maxseg(tp))))) {
/*
* There is no sense of continuing this measurement
* because its too small to gain us anything we
* trust. Skip it and that way we can start a new
* measurement quicker.
*/
rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
0, 0, 0, 6, __LINE__, NULL);
tp->t_flags &= ~TF_GPUTINPROG;
}
}
}
static uint32_t
rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
{
uint32_t start, end, changed = 0;
struct rack_sendmap stack_map;
struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next;
int32_t used_ref = 1;
int moved = 0;
start = sack->start;
end = sack->end;
rsm = *prsm;
memset(&fe, 0, sizeof(fe));
do_rest_ofb:
if ((rsm == NULL) ||
(SEQ_LT(end, rsm->r_start)) ||
(SEQ_GEQ(start, rsm->r_end)) ||
(SEQ_LT(start, rsm->r_start))) {
/*
* We are not in the right spot,
* find the correct spot in the tree.
*/
used_ref = 0;
fe.r_start = start;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
moved++;
}
if (rsm == NULL) {
/* TSNH */
goto out;
}
/* Ok we have an ACK for some piece of this rsm */
if (rsm->r_start != start) {
if ((rsm->r_flags & RACK_ACKED) == 0) {
/**
* Need to split this in two pieces the before and after,
* the before remains in the map, the after must be
* added. In other words we have:
* rsm |--------------|
* sackblk |------->
* rsm will become
* rsm |---|
* and nrsm will be the sacked piece
* nrsm |----------|
*
* But before we start down that path lets
* see if the sack spans over on top of
* the next guy and it is already sacked.
*/
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (next && (next->r_flags & RACK_ACKED) &&
SEQ_GEQ(end, next->r_start)) {
/**
* So the next one is already acked, and
* we can thus by hookery use our stack_map
* to reflect the piece being sacked and
* then adjust the two tree entries moving
* the start and ends around. So we start like:
* rsm |------------| (not-acked)
* next |-----------| (acked)
* sackblk |-------->
* We want to end like so:
* rsm |------| (not-acked)
* next |-----------------| (acked)
* nrsm |-----|
* Where nrsm is a temporary stack piece we
* use to update all the gizmos.
*/
/* Copy up our fudge block */
nrsm = &stack_map;
memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
/* Now adjust our tree blocks */
rsm->r_end = start;
next->r_start = start;
/* Clear out the dup ack count of the remainder */
rsm->r_dupack = 0;
rsm->r_just_ret = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
/* Now lets make sure our fudge block is right */
nrsm->r_start = start;
/* Now lets update all the stats and such */
rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
changed += (nrsm->r_end - nrsm->r_start);
rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
if (nrsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
/*
* Now we want to go up from rsm (the
* one left un-acked) to the next one
* in the tmap. We do this so when
* we walk backwards we include marking
* sack-passed on rsm (The one passed in
* is skipped since it is generally called
* on something sacked before removing it
* from the tmap).
*/
if (rsm->r_in_tmap) {
nrsm = TAILQ_NEXT(rsm, r_tnext);
/*
* Now that we have the next
* one walk backwards from there.
*/
if (nrsm && nrsm->r_in_tmap)
rack_log_sack_passed(tp, rack, nrsm);
}
/* Now are we done? */
if (SEQ_LT(end, next->r_end) ||
(end == next->r_end)) {
/* Done with block */
goto out;
}
counter_u64_add(rack_sack_used_next_merge, 1);
/* Postion for the next block */
start = next->r_end;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
if (rsm == NULL)
goto out;
} else {
/**
* We can't use any hookery here, so we
* need to split the map. We enter like
* so:
* rsm |--------|
* sackblk |----->
* We will add the new block nrsm and
* that will be the new portion, and then
* fall through after reseting rsm. So we
* split and look like this:
* rsm |----|
* sackblk |----->
* nrsm |---|
* We then fall through reseting
* rsm to nrsm, so the next block
* picks it up.
*/
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/*
* failed XXXrrs what can we do but loose the sack
* info?
*/
goto out;
}
counter_u64_add(rack_sack_splits, 1);
rack_clone_rsm(rack, nrsm, rsm, start);
rsm->r_just_ret = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
/* Position us to point to the new nrsm that starts the sack blk */
rsm = nrsm;
}
} else {
/* Already sacked this piece */
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
if (end == rsm->r_end) {
/* Done with block */
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
goto out;
} else if (SEQ_LT(end, rsm->r_end)) {
/* A partial sack to a already sacked block */
moved++;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
goto out;
} else {
/*
* The end goes beyond this guy
* repostion the start to the
* next block.
*/
start = rsm->r_end;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (rsm == NULL)
goto out;
}
}
}
if (SEQ_GEQ(end, rsm->r_end)) {
/**
* The end of this block is either beyond this guy or right
* at this guy. I.e.:
* rsm --- |-----|
* end |-----|
* <or>
* end |---------|
*/
if ((rsm->r_flags & RACK_ACKED) == 0) {
rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
if (rsm->r_in_tmap) /* should be true */
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rsm->r_flags &= ~RACK_TLP;
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
} else {
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
}
if (end == rsm->r_end) {
/* This block only - done, setup for next */
goto out;
}
/*
* There is more not coverend by this rsm move on
* to the next block in the RB tree.
*/
nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
start = rsm->r_end;
rsm = nrsm;
if (rsm == NULL)
goto out;
goto do_rest_ofb;
}
/**
* The end of this sack block is smaller than
* our rsm i.e.:
* rsm --- |-----|
* end |--|
*/
if ((rsm->r_flags & RACK_ACKED) == 0) {
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (prev && (prev->r_flags & RACK_ACKED)) {
/**
* Goal, we want the right remainder of rsm to shrink
* in place and span from (rsm->r_start = end) to rsm->r_end.
* We want to expand prev to go all the way
* to prev->r_end <- end.
* so in the tree we have before:
* prev |--------| (acked)
* rsm |-------| (non-acked)
* sackblk |-|
* We churn it so we end up with
* prev |----------| (acked)
* rsm |-----| (non-acked)
* nrsm |-| (temporary)
*/
nrsm = &stack_map;
memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
prev->r_end = end;
rsm->r_start = end;
/* Now adjust nrsm (stack copy) to be
* the one that is the small
* piece that was "sacked".
*/
nrsm->r_end = end;
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
/*
* Now nrsm is our new little piece
* that is acked (which was merged
* to prev). Update the rtt and changed
* based on that. Also check for reordering.
*/
rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
changed += (nrsm->r_end - nrsm->r_start);
rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
if (nrsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
rsm = prev;
counter_u64_add(rack_sack_used_prev_merge, 1);
} else {
/**
* This is the case where our previous
* block is not acked either, so we must
* split the block in two.
*/
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* failed rrs what can we do but loose the sack info? */
goto out;
}
/**
* In this case nrsm becomes
* nrsm->r_start = end;
* nrsm->r_end = rsm->r_end;
* which is un-acked.
* <and>
* rsm->r_end = nrsm->r_start;
* i.e. the remaining un-acked
* piece is left on the left
* hand side.
*
* So we start like this
* rsm |----------| (not acked)
* sackblk |---|
* build it so we have
* rsm |---| (acked)
* nrsm |------| (not acked)
*/
counter_u64_add(rack_sack_splits, 1);
rack_clone_rsm(rack, nrsm, rsm, end);
rsm->r_flags &= (~RACK_HAS_FIN);
rsm->r_just_ret = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
nrsm->r_dupack = 0;
rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
if (rsm->r_in_tmap) /* should be true */
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rsm->r_flags &= ~RACK_TLP;
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
}
} else if (start != end){
/*
* The block was already acked.
*/
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
}
out:
if (rsm && (rsm->r_flags & RACK_ACKED)) {
/*
* Now can we merge where we worked
* with either the previous or
* next block?
*/
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
while (next) {
if (next->r_flags & RACK_ACKED) {
/* yep this and next can be merged */
rsm = rack_merge_rsm(rack, rsm, next);
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
} else
break;
}
/* Now what about the previous? */
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
while (prev) {
if (prev->r_flags & RACK_ACKED) {
/* yep the previous and this can be merged */
rsm = rack_merge_rsm(rack, prev, rsm);
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
} else
break;
}
}
if (used_ref == 0) {
counter_u64_add(rack_sack_proc_all, 1);
} else {
counter_u64_add(rack_sack_proc_short, 1);
}
/* Save off the next one for quick reference. */
if (rsm)
nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
else
nrsm = NULL;
*prsm = rack->r_ctl.rc_sacklast = nrsm;
/* Pass back the moved. */
*moved_two = moved;
return (changed);
}
static void inline
rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
{
struct rack_sendmap *tmap;
tmap = NULL;
while (rsm && (rsm->r_flags & RACK_ACKED)) {
/* Its no longer sacked, mark it so */
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
#ifdef INVARIANTS
if (rsm->r_in_tmap) {
panic("rack:%p rsm:%p flags:0x%x in tmap?",
rack, rsm, rsm->r_flags);
}
#endif
rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
/* Rebuild it into our tmap */
if (tmap == NULL) {
TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
tmap = rsm;
} else {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
tmap = rsm;
}
tmap->r_in_tmap = 1;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
}
/*
* Now lets possibly clear the sack filter so we start
* recognizing sacks that cover this area.
*/
sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
}
static void
rack_do_decay(struct tcp_rack *rack)
{
struct timeval res;
#define timersub(tvp, uvp, vvp) \
do { \
(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \
(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \
if ((vvp)->tv_usec < 0) { \
(vvp)->tv_sec--; \
(vvp)->tv_usec += 1000000; \
} \
} while (0)
timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
#undef timersub
rack->r_ctl.input_pkt++;
if ((rack->rc_in_persist) ||
(res.tv_sec >= 1) ||
(rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
/*
* Check for decay of non-SAD,
* we want all SAD detection metrics to
* decay 1/4 per second (or more) passed.
*/
uint32_t pkt_delta;
pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
/* Update our saved tracking values */
rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
/* Now do we escape without decay? */
#ifdef NETFLIX_EXP_DETECTION
if (rack->rc_in_persist ||
(rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
(pkt_delta < tcp_sad_low_pps)){
/*
* We don't decay idle connections
* or ones that have a low input pps.
*/
return;
}
/* Decay the counters */
rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
tcp_sad_decay_val);
rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
tcp_sad_decay_val);
rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
tcp_sad_decay_val);
rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
tcp_sad_decay_val);
#endif
}
}
static void
rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th)
{
uint32_t changed, entered_recovery = 0;
struct tcp_rack *rack;
struct rack_sendmap *rsm, *rm;
struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
register uint32_t th_ack;
int32_t i, j, k, num_sack_blks = 0;
uint32_t cts, acked, ack_point, sack_changed = 0;
int loop_start = 0, moved_two = 0;
uint32_t tsused;
INP_WLOCK_ASSERT(tp->t_inpcb);
if (th->th_flags & TH_RST) {
/* We don't log resets */
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
cts = tcp_ts_getticks();
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
changed = 0;
th_ack = th->th_ack;
if (rack->sack_attack_disable == 0)
rack_do_decay(rack);
if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
/*
* You only get credit for
* MSS and greater (and you get extra
* credit for larger cum-ack moves).
*/
int ac;
ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
rack->r_ctl.ack_count += ac;
counter_u64_add(rack_ack_total, ac);
}
if (rack->r_ctl.ack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
if (SEQ_GT(th_ack, tp->snd_una)) {
rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
tp->t_acktime = ticks;
}
if (rsm && SEQ_GT(th_ack, rsm->r_start))
changed = th_ack - rsm->r_start;
if (changed) {
/*
* The ACK point is advancing to th_ack, we must drop off
* the packets in the rack log and calculate any eligble
* RTT's.
*/
rack->r_wanted_output = 1;
more:
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm == NULL) {
if ((th_ack - 1) == tp->iss) {
/*
* For the SYN incoming case we will not
* have called tcp_output for the sending of
* the SYN, so there will be no map. All
* other cases should probably be a panic.
*/
goto proc_sack;
}
if (tp->t_flags & TF_SENTFIN) {
/* if we send a FIN we will not hav a map */
goto proc_sack;
}
#ifdef INVARIANTS
panic("No rack map tp:%p for th:%p state:%d rack:%p snd_una:%u snd_max:%u snd_nxt:%u chg:%d\n",
tp,
th, tp->t_state, rack,
tp->snd_una, tp->snd_max, tp->snd_nxt, changed);
#endif
goto proc_sack;
}
if (SEQ_LT(th_ack, rsm->r_start)) {
/* Huh map is missing this */
#ifdef INVARIANTS
printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
rsm->r_start,
th_ack, tp->t_state, rack->r_state);
#endif
goto proc_sack;
}
rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
/* Now do we consume the whole thing? */
if (SEQ_GEQ(th_ack, rsm->r_end)) {
/* Its all consumed. */
uint32_t left;
uint8_t newly_acked;
rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
/* Record the time of highest cumack sent */
rack->r_ctl.rc_gp_cumack_ts = rsm->usec_orig_send;
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (rm != rsm) {
panic("removing head in rack:%p rsm:%p rm:%p",
rack, rsm, rm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
newly_acked = 1;
if (rsm->r_flags & RACK_ACKED) {
/*
* It was acked on the scoreboard -- remove
* it from total
*/
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
newly_acked = 0;
} else if (rsm->r_flags & RACK_SACK_PASSED) {
/*
* There are segments ACKED on the
* scoreboard further up. We are seeing
* reordering.
*/
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rack->r_ctl.rc_reorder_ts = cts;
}
left = th_ack - rsm->r_end;
if (rack->app_limited_needs_set && newly_acked)
rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
/* Free back to zone */
rack_free(rack, rsm);
if (left) {
goto more;
}
goto proc_sack;
}
if (rsm->r_flags & RACK_ACKED) {
/*
* It was acked on the scoreboard -- remove it from
* total for the part being cum-acked.
*/
rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
}
/*
* Clear the dup ack count for
* the piece that remains.
*/
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
if (rsm->r_rtr_bytes) {
/*
* It was retransmitted adjust the
* sack holes for what was acked.
*/
int ack_am;
ack_am = (th_ack - rsm->r_start);
if (ack_am >= rsm->r_rtr_bytes) {
rack->r_ctl.rc_holes_rxt -= ack_am;
rsm->r_rtr_bytes -= ack_am;
}
}
/*
* Update where the piece starts and record
* the time of send of highest cumack sent.
*/
rack->r_ctl.rc_gp_cumack_ts = rsm->usec_orig_send;
rsm->r_start = th_ack;
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
}
proc_sack:
/* Check for reneging */
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
/*
* The peer has moved snd_una up to
* the edge of this send, i.e. one
* that it had previously acked. The only
* way that can be true if the peer threw
* away data (space issues) that it had
* previously sacked (else it would have
* given us snd_una up to (rsm->r_end).
* We need to undo the acked markings here.
*
* Note we have to look to make sure th_ack is
* our rsm->r_start in case we get an old ack
* where th_ack is behind snd_una.
*/
rack_peer_reneges(rack, rsm, th->th_ack);
}
if ((to->to_flags & TOF_SACK) == 0) {
/* We are done nothing left */
goto out;
}
/* Sack block processing */
if (SEQ_GT(th_ack, tp->snd_una))
ack_point = th_ack;
else
ack_point = tp->snd_una;
for (i = 0; i < to->to_nsacks; i++) {
bcopy((to->to_sacks + i * TCPOLEN_SACK),
&sack, sizeof(sack));
sack.start = ntohl(sack.start);
sack.end = ntohl(sack.end);
if (SEQ_GT(sack.end, sack.start) &&
SEQ_GT(sack.start, ack_point) &&
SEQ_LT(sack.start, tp->snd_max) &&
SEQ_GT(sack.end, ack_point) &&
SEQ_LEQ(sack.end, tp->snd_max)) {
sack_blocks[num_sack_blks] = sack;
num_sack_blks++;
#ifdef NETFLIX_STATS
} else if (SEQ_LEQ(sack.start, th_ack) &&
SEQ_LEQ(sack.end, th_ack)) {
/*
* Its a D-SACK block.
*/
tcp_record_dsack(sack.start, sack.end);
#endif
}
}
/*
* Sort the SACK blocks so we can update the rack scoreboard with
* just one pass.
*/
num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
num_sack_blks, th->th_ack);
ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
if (num_sack_blks == 0) {
/* Nothing to sack (DSACKs?) */
goto out_with_totals;
}
if (num_sack_blks < 2) {
/* Only one, we don't need to sort */
goto do_sack_work;
}
/* Sort the sacks */
for (i = 0; i < num_sack_blks; i++) {
for (j = i + 1; j < num_sack_blks; j++) {
if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
sack = sack_blocks[i];
sack_blocks[i] = sack_blocks[j];
sack_blocks[j] = sack;
}
}
}
/*
* Now are any of the sack block ends the same (yes some
* implementations send these)?
*/
again:
if (num_sack_blks == 0)
goto out_with_totals;
if (num_sack_blks > 1) {
for (i = 0; i < num_sack_blks; i++) {
for (j = i + 1; j < num_sack_blks; j++) {
if (sack_blocks[i].end == sack_blocks[j].end) {
/*
* Ok these two have the same end we
* want the smallest end and then
* throw away the larger and start
* again.
*/
if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
/*
* The second block covers
* more area use that
*/
sack_blocks[i].start = sack_blocks[j].start;
}
/*
* Now collapse out the dup-sack and
* lower the count
*/
for (k = (j + 1); k < num_sack_blks; k++) {
sack_blocks[j].start = sack_blocks[k].start;
sack_blocks[j].end = sack_blocks[k].end;
j++;
}
num_sack_blks--;
goto again;
}
}
}
}
do_sack_work:
/*
* First lets look to see if
* we have retransmitted and
* can use the transmit next?
*/
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm &&
SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
/*
* We probably did the FR and the next
* SACK in continues as we would expect.
*/
acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
if (acked) {
rack->r_wanted_output = 1;
changed += acked;
sack_changed += acked;
}
if (num_sack_blks == 1) {
/*
* This is what we would expect from
* a normal implementation to happen
* after we have retransmitted the FR,
* i.e the sack-filter pushes down
* to 1 block and the next to be retransmitted
* is the sequence in the sack block (has more
* are acked). Count this as ACK'd data to boost
* up the chances of recovering any false positives.
*/
rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
counter_u64_add(rack_express_sack, 1);
if (rack->r_ctl.ack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
goto out_with_totals;
} else {
/*
* Start the loop through the
* rest of blocks, past the first block.
*/
moved_two = 0;
loop_start = 1;
}
}
/* Its a sack of some sort */
rack->r_ctl.sack_count++;
if (rack->r_ctl.sack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
counter_u64_add(rack_sack_total, 1);
if (rack->sack_attack_disable) {
/* An attacker disablement is in place */
if (num_sack_blks > 1) {
rack->r_ctl.sack_count += (num_sack_blks - 1);
rack->r_ctl.sack_moved_extra++;
counter_u64_add(rack_move_some, 1);
if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
rack->r_ctl.sack_moved_extra /= 2;
rack->r_ctl.sack_noextra_move /= 2;
}
}
goto out;
}
rsm = rack->r_ctl.rc_sacklast;
for (i = loop_start; i < num_sack_blks; i++) {
acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
if (acked) {
rack->r_wanted_output = 1;
changed += acked;
sack_changed += acked;
}
if (moved_two) {
/*
* If we did not get a SACK for at least a MSS and
* had to move at all, or if we moved more than our
* threshold, it counts against the "extra" move.
*/
rack->r_ctl.sack_moved_extra += moved_two;
counter_u64_add(rack_move_some, 1);
} else {
/*
* else we did not have to move
* any more than we would expect.
*/
rack->r_ctl.sack_noextra_move++;
counter_u64_add(rack_move_none, 1);
}
if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
/*
* If the SACK was not a full MSS then
* we add to sack_count the number of
* MSS's (or possibly more than
* a MSS if its a TSO send) we had to skip by.
*/
rack->r_ctl.sack_count += moved_two;
counter_u64_add(rack_sack_total, moved_two);
}
/*
* Now we need to setup for the next
* round. First we make sure we won't
* exceed the size of our uint32_t on
* the various counts, and then clear out
* moved_two.
*/
if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
(rack->r_ctl.sack_noextra_move > 0xfff00000)) {
rack->r_ctl.sack_moved_extra /= 2;
rack->r_ctl.sack_noextra_move /= 2;
}
if (rack->r_ctl.sack_count > 0xfff00000) {
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
moved_two = 0;
}
out_with_totals:
if (num_sack_blks > 1) {
/*
* You get an extra stroke if
* you have more than one sack-blk, this
* could be where we are skipping forward
* and the sack-filter is still working, or
* it could be an attacker constantly
* moving us.
*/
rack->r_ctl.sack_moved_extra++;
counter_u64_add(rack_move_some, 1);
}
out:
#ifdef NETFLIX_EXP_DETECTION
if ((rack->do_detection || tcp_force_detection) &&
tcp_sack_to_ack_thresh &&
tcp_sack_to_move_thresh &&
((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
/*
* We have thresholds set to find
* possible attackers and disable sack.
* Check them.
*/
uint64_t ackratio, moveratio, movetotal;
/* Log detecting */
rack_log_sad(rack, 1);
ackratio = (uint64_t)(rack->r_ctl.sack_count);
ackratio *= (uint64_t)(1000);
if (rack->r_ctl.ack_count)
ackratio /= (uint64_t)(rack->r_ctl.ack_count);
else {
/* We really should not hit here */
ackratio = 1000;
}
if ((rack->sack_attack_disable == 0) &&
(ackratio > rack_highest_sack_thresh_seen))
rack_highest_sack_thresh_seen = (uint32_t)ackratio;
movetotal = rack->r_ctl.sack_moved_extra;
movetotal += rack->r_ctl.sack_noextra_move;
moveratio = rack->r_ctl.sack_moved_extra;
moveratio *= (uint64_t)1000;
if (movetotal)
moveratio /= movetotal;
else {
/* No moves, thats pretty good */
moveratio = 0;
}
if ((rack->sack_attack_disable == 0) &&
(moveratio > rack_highest_move_thresh_seen))
rack_highest_move_thresh_seen = (uint32_t)moveratio;
if (rack->sack_attack_disable == 0) {
if ((ackratio > tcp_sack_to_ack_thresh) &&
(moveratio > tcp_sack_to_move_thresh)) {
/* Disable sack processing */
rack->sack_attack_disable = 1;
if (rack->r_rep_attack == 0) {
rack->r_rep_attack = 1;
counter_u64_add(rack_sack_attacks_detected, 1);
}
if (tcp_attack_on_turns_on_logging) {
/*
* Turn on logging, used for debugging
* false positives.
*/
rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
}
/* Clamp the cwnd at flight size */
rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
rack_log_sad(rack, 2);
}
} else {
/* We are sack-disabled check for false positives */
if ((ackratio <= tcp_restoral_thresh) ||
(rack->r_ctl.rc_num_maps_alloced < tcp_map_minimum)) {
rack->sack_attack_disable = 0;
rack_log_sad(rack, 3);
/* Restart counting */
rack->r_ctl.sack_count = 0;
rack->r_ctl.sack_moved_extra = 0;
rack->r_ctl.sack_noextra_move = 1;
rack->r_ctl.ack_count = max(1,
(BYTES_THIS_ACK(tp, th)/ctf_fixed_maxseg(rack->rc_tp)));
if (rack->r_rep_reverse == 0) {
rack->r_rep_reverse = 1;
counter_u64_add(rack_sack_attacks_reversed, 1);
}
/* Restore the cwnd */
if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
}
}
}
#endif
if (changed) {
/* Something changed cancel the rack timer */
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
}
tsused = tcp_ts_getticks();
rsm = tcp_rack_output(tp, rack, tsused);
if ((!IN_RECOVERY(tp->t_flags)) &&
rsm) {
/* Enter recovery */
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
entered_recovery = 1;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure we send
* one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 8, 0);
}
rack->r_timer_override = 1;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
} else if (IN_RECOVERY(tp->t_flags) &&
rsm &&
(rack->r_rr_config == 3)) {
/*
* Assure we can output and we get no
* remembered pace time except the retransmit.
*/
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack->r_ctl.rc_resend = rsm;
}
if (IN_RECOVERY(tp->t_flags) &&
(rack->rack_no_prr == 0) &&
(entered_recovery == 0)) {
/* Deal with PRR here (in recovery only) */
uint32_t pipe, snd_una;
rack->r_ctl.rc_prr_delivered += changed;
/* Compute prr_sndcnt */
if (SEQ_GT(tp->snd_una, th_ack)) {
snd_una = tp->snd_una;
} else {
snd_una = th_ack;
}
pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
if (pipe > tp->snd_ssthresh) {
long sndcnt;
sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
if (rack->r_ctl.rc_prr_recovery_fs > 0)
sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
else {
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 9, 0);
sndcnt = 0;
}
sndcnt++;
if (sndcnt > (long)rack->r_ctl.rc_prr_out)
sndcnt -= rack->r_ctl.rc_prr_out;
else
sndcnt = 0;
rack->r_ctl.rc_prr_sndcnt = sndcnt;
rack_log_to_prr(rack, 10, 0);
} else {
uint32_t limit;
if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
else
limit = 0;
if (changed > limit)
limit = changed;
limit += ctf_fixed_maxseg(tp);
if (tp->snd_ssthresh > pipe) {
rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
rack_log_to_prr(rack, 11, 0);
} else {
rack->r_ctl.rc_prr_sndcnt = min(0, limit);
rack_log_to_prr(rack, 12, 0);
}
}
if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
((rack->rc_inp->inp_in_hpts == 0) &&
((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
/*
* If you are pacing output you don't want
* to override.
*/
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
rack->r_timer_override = 1;
}
}
}
static void
rack_strike_dupack(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm && (rsm->r_dupack < 0xff)) {
rsm->r_dupack++;
if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
rack->r_wanted_output = 1;
rack->r_timer_override = 1;
rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
} else {
rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
}
}
}
static void
rack_check_bottom_drag(struct tcpcb *tp,
struct tcp_rack *rack,
struct socket *so, int32_t acked)
{
uint32_t segsiz, minseg;
segsiz = ctf_fixed_maxseg(tp);
if (so->so_snd.sb_flags & SB_TLS_IFNET) {
minseg = rack->r_ctl.rc_pace_min_segs;
} else {
minseg = segsiz;
}
if (tp->snd_max == tp->snd_una) {
/*
* We are doing dynamic pacing and we are way
* under. Basically everything got acked while
* we were still waiting on the pacer to expire.
*
* This means we need to boost the b/w in
* addition to any earlier boosting of
* the multipler.
*/
rack->rc_dragged_bottom = 1;
rack_validate_multipliers_at_or_above100(rack);
/*
* Lets use the segment bytes acked plus
* the lowest RTT seen as the basis to
* form a b/w estimate. This will be off
* due to the fact that the true estimate
* should be around 1/2 the time of the RTT
* but we can settle for that.
*/
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
acked) {
uint64_t bw, calc_bw, rtt;
rtt = rack->r_ctl.rack_rs.rs_us_rtt;
bw = acked;
calc_bw = bw * 1000000;
calc_bw /= rtt;
if (rack->r_ctl.last_max_bw &&
(rack->r_ctl.last_max_bw < calc_bw)) {
/*
* If we have a last calculated max bw
* enforce it.
*/
calc_bw = rack->r_ctl.last_max_bw;
}
/* now plop it in */
if (rack->rc_gp_filled == 0) {
if (calc_bw > ONE_POINT_TWO_MEG) {
/*
* If we have no measurement
* don't let us set in more than
* 1.2Mbps. If we are still too
* low after pacing with this we
* will hopefully have a max b/w
* available to sanity check things.
*/
calc_bw = ONE_POINT_TWO_MEG;
}
rack->r_ctl.rc_rtt_diff = 0;
rack->r_ctl.gp_bw = calc_bw;
rack->rc_gp_filled = 1;
rack->r_ctl.num_avg = RACK_REQ_AVG;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else if (calc_bw > rack->r_ctl.gp_bw) {
rack->r_ctl.rc_rtt_diff = 0;
rack->r_ctl.num_avg = RACK_REQ_AVG;
rack->r_ctl.gp_bw = calc_bw;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else
rack_increase_bw_mul(rack, -1, 0, 0, 1);
/*
* For acks over 1mss we do a extra boost to simulate
* where we would get 2 acks (we want 110 for the mul).
*/
if (acked > segsiz)
rack_increase_bw_mul(rack, -1, 0, 0, 1);
} else {
/*
* Huh, this should not be, settle
* for just an old increase.
*/
rack_increase_bw_mul(rack, -1, 0, 0, 1);
}
} else if ((IN_RECOVERY(tp->t_flags) == 0) &&
(sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
minseg)) &&
(rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
(tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
(segsiz * rack_req_segs))) {
/*
* We are doing dynamic GP pacing and
* we have everything except 1MSS or less
* bytes left out. We are still pacing away.
* And there is data that could be sent, This
* means we are inserting delayed ack time in
* our measurements because we are pacing too slow.
*/
rack_validate_multipliers_at_or_above100(rack);
rack->rc_dragged_bottom = 1;
rack_increase_bw_mul(rack, -1, 0, 0, 1);
}
}
/*
* Return value of 1, we do not need to call rack_process_data().
* return value of 0, rack_process_data can be called.
* For ret_val if its 0 the TCP is locked, if its non-zero
* its unlocked and probably unsafe to touch the TCB.
*/
static int
rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to,
uint32_t tiwin, int32_t tlen,
int32_t * ofia, int32_t thflags, int32_t * ret_val)
{
int32_t ourfinisacked = 0;
int32_t nsegs, acked_amount;
int32_t acked;
struct mbuf *mfree;
struct tcp_rack *rack;
int32_t under_pacing = 0;
int32_t recovery = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (SEQ_GT(th->th_ack, tp->snd_max)) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
rack->r_wanted_output = 1;
return (1);
}
if (rack->rc_gp_filled &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
under_pacing = 1;
}
if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
if (rack->rc_in_persist)
tp->t_rxtshift = 0;
if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
rack_strike_dupack(rack);
rack_log_ack(tp, to, th);
}
if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
/*
* Old ack, behind (or duplicate to) the last one rcv'd
* Note: Should mark reordering is occuring! We should also
* look for sack blocks arriving e.g. ack 1, 4-4 then ack 1,
* 3-3, 4-4 would be reording. As well as ack 1, 3-3 <no
* retran and> ack 3
*/
return (0);
}
/*
* If we reach this point, ACK is not a duplicate, i.e., it ACKs
* something we sent.
*/
if (tp->t_flags & TF_NEEDSYN) {
/*
* T/TCP: Connection was half-synchronized, and our SYN has
* been ACK'd (so connection is now fully synchronized). Go
* to non-starred state, increment snd_una for ACK of SYN,
* and check if we can do window scaling.
*/
tp->t_flags &= ~TF_NEEDSYN;
tp->snd_una++;
/* Do window scaling? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
/* Send window already scaled. */
}
}
nsegs = max(1, m->m_pkthdr.lro_nsegs);
INP_WLOCK_ASSERT(tp->t_inpcb);
acked = BYTES_THIS_ACK(tp, th);
KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
/*
* If we just performed our first retransmit, and the ACK arrives
* within our recovery window, then it was a mistake to do the
* retransmit in the first place. Recover our original cwnd and
* ssthresh, and proceed to transmit where we left off.
*/
if (tp->t_flags & TF_PREVVALID) {
tp->t_flags &= ~TF_PREVVALID;
if (tp->t_rxtshift == 1 &&
(int)(ticks - tp->t_badrxtwin) < 0)
rack_cong_signal(tp, th, CC_RTO_ERR);
}
if (acked) {
/* assure we are not backed off */
tp->t_rxtshift = 0;
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
/*
* If it is the RXT timer we want to
* stop it, so we can restart a TLP.
*/
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
#ifdef NETFLIX_HTTP_LOGGING
tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
#endif
}
/*
* If we have a timestamp reply, update smoothed round trip time. If
* no timestamp is present but transmit timer is running and timed
* sequence number was acked, update smoothed round trip time. Since
* we now have an rtt measurement, cancel the timer backoff (cf.,
* Phil Karn's retransmit alg.). Recompute the initial retransmit
* timer.
*
* Some boxes send broken timestamp replies during the SYN+ACK
* phase, ignore timestamps of 0 or we could calculate a huge RTT
* and blow up the retransmit timer.
*/
/*
* If all outstanding data is acked, stop retransmit timer and
* remember to restart (more output or persist). If there is more
* data to be acked, restart retransmit timer, using current
* (possibly backed-off) value.
*/
if (acked == 0) {
if (ofia)
*ofia = ourfinisacked;
return (0);
}
if (rack->r_ctl.rc_early_recovery) {
if (IN_RECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover) &&
(SEQ_LT(th->th_ack, tp->snd_max))) {
tcp_rack_partialack(tp, th);
} else {
rack_post_recovery(tp, th);
recovery = 1;
}
}
}
/*
* Let the congestion control algorithm update congestion control
* related information. This typically means increasing the
* congestion window.
*/
rack_ack_received(tp, rack, th, nsegs, CC_ACK, recovery);
SOCKBUF_LOCK(&so->so_snd);
acked_amount = min(acked, (int)sbavail(&so->so_snd));
tp->snd_wnd -= acked_amount;
mfree = sbcut_locked(&so->so_snd, acked_amount);
if ((sbused(&so->so_snd) == 0) &&
(acked > acked_amount) &&
(tp->t_state >= TCPS_FIN_WAIT_1) &&
(tp->t_flags & TF_SENTFIN)) {
/*
* We must be sure our fin
* was sent and acked (we can be
* in FIN_WAIT_1 without having
* sent the fin).
*/
ourfinisacked = 1;
}
/* NB: sowwakeup_locked() does an implicit unlock. */
sowwakeup_locked(so);
m_freem(mfree);
if (rack->r_ctl.rc_early_recovery == 0) {
if (IN_RECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover) &&
(SEQ_LT(th->th_ack, tp->snd_max))) {
tcp_rack_partialack(tp, th);
} else {
rack_post_recovery(tp, th);
}
}
}
tp->snd_una = th->th_ack;
if (SEQ_GT(tp->snd_una, tp->snd_recover))
tp->snd_recover = tp->snd_una;
if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
tp->snd_nxt = tp->snd_una;
}
if (under_pacing &&
(rack->use_fixed_rate == 0) &&
(rack->in_probe_rtt == 0) &&
rack->rc_gp_dyn_mul &&
rack->rc_always_pace) {
/* Check if we are dragging bottom */
rack_check_bottom_drag(tp, rack, so, acked);
}
if (tp->snd_una == tp->snd_max) {
/* Nothing left outstanding */
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
tp->t_acktime = 0;
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
/* Set need output so persist might get set */
rack->r_wanted_output = 1;
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
(sbavail(&so->so_snd) == 0) &&
(tp->t_flags2 & TF2_DROP_AF_DATA)) {
/*
* The socket was gone and the
* peer sent data, time to
* reset him.
*/
*ret_val = 1;
/* tcp_close will kill the inp pre-log the Reset */
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
tp = tcp_close(tp);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
return (1);
}
}
if (ofia)
*ofia = ourfinisacked;
return (0);
}
static void
rack_collapsed_window(struct tcp_rack *rack)
{
/*
* Now we must walk the
* send map and divide the
* ones left stranded. These
* guys can't cause us to abort
* the connection and are really
* "unsent". However if a buggy
* client actually did keep some
* of the data i.e. collapsed the win
* and refused to ack and then opened
* the win and acked that data. We would
* get into an ack war, the simplier
* method then of just pretending we
* did not send those segments something
* won't work.
*/
struct rack_sendmap *rsm, *nrsm, fe, *insret;
tcp_seq max_seq;
max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
memset(&fe, 0, sizeof(fe));
fe.r_start = max_seq;
/* Find the first seq past or at maxseq */
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm == NULL) {
/* Nothing to do strange */
rack->rc_has_collapsed = 0;
return;
}
/*
* Now do we need to split at
* the collapse point?
*/
if (SEQ_GT(max_seq, rsm->r_start)) {
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* We can't get a rsm, mark all? */
nrsm = rsm;
goto no_split;
}
/* Clone it */
rack_clone_rsm(rack, nrsm, rsm, max_seq);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
/*
* Set in the new RSM as the
* collapsed starting point
*/
rsm = nrsm;
}
no_split:
counter_u64_add(rack_collapsed_win, 1);
RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
nrsm->r_flags |= RACK_RWND_COLLAPSED;
rack->rc_has_collapsed = 1;
}
}
static void
rack_un_collapse_window(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if (rsm->r_flags & RACK_RWND_COLLAPSED)
rsm->r_flags &= ~RACK_RWND_COLLAPSED;
else
break;
}
rack->rc_has_collapsed = 0;
}
static void
rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
int32_t tlen, int32_t tfo_syn)
{
if (DELAY_ACK(tp, tlen) || tfo_syn) {
if (rack->rc_dack_mode &&
(tlen > 500) &&
(rack->rc_dack_toggle == 1)) {
goto no_delayed_ack;
}
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
no_delayed_ack:
rack->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
if (rack->rc_dack_mode) {
if (tp->t_flags & TF_DELACK)
rack->rc_dack_toggle = 1;
else
rack->rc_dack_toggle = 0;
}
}
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
{
/*
* Update window information. Don't look at window if no ACK: TAC's
* send garbage on first SYN.
*/
int32_t nsegs;
int32_t tfo_syn;
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
nsegs = max(1, m->m_pkthdr.lro_nsegs);
if ((thflags & TH_ACK) &&
(SEQ_LT(tp->snd_wl1, th->th_seq) ||
(tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
(tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
/* keep track of pure window updates */
if (tlen == 0 &&
tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
KMOD_TCPSTAT_INC(tcps_rcvwinupd);
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
tp->snd_wl2 = th->th_ack;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
rack->r_wanted_output = 1;
} else if (thflags & TH_ACK) {
if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
tp->snd_wl2 = th->th_ack;
}
}
if (tp->snd_wnd < ctf_outstanding(tp))
/* The peer collapsed the window */
rack_collapsed_window(rack);
else if (rack->rc_has_collapsed)
rack_un_collapse_window(rack);
/* Was persist timer active and now we have window space? */
if ((rack->rc_in_persist != 0) &&
(tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
rack->r_ctl.rc_pace_min_segs))) {
rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
tp->snd_nxt = tp->snd_max;
/* Make sure we output to start the timer */
rack->r_wanted_output = 1;
}
/* Do we enter persists? */
if ((rack->rc_in_persist == 0) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/*
* Here the rwnd is less than
* the pacing size, we are established,
* nothing is outstanding, and there is
* data to send. Enter persists.
*/
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
if (tp->t_flags2 & TF2_DROP_AF_DATA) {
m_freem(m);
return (0);
}
/*
* don't process the URG bit, ignore them drag
* along the up.
*/
tp->rcv_up = tp->rcv_nxt;
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* Process the segment text, merging it into the TCP sequencing
* queue, and arranging for acknowledgment of receipt if necessary.
* This process logically involves adjusting tp->rcv_wnd as data is
* presented to the user (this happens in tcp_usrreq.c, case
* PRU_RCVD). If a FIN has already been received on this connection
* then we just ignore the text.
*/
tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
IS_FASTOPEN(tp->t_flags));
if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tcp_seq save_start = th->th_seq;
tcp_seq save_rnxt = tp->rcv_nxt;
int save_tlen = tlen;
m_adj(m, drop_hdrlen); /* delayed header drop */
/*
* Insert segment which includes th into TCP reassembly
* queue with control block tp. Set thflags to whether
* reassembly now includes a segment with FIN. This handles
* the common case inline (segment is the next to be
* received on an established connection, and the queue is
* empty), avoiding linkage into and removal from the queue
* and repetition of various conversions. Set DELACK for
* segments received in order, but ack immediately when
* segments are out of order (so fast retransmit can work).
*/
if (th->th_seq == tp->rcv_nxt &&
SEGQ_EMPTY(tp) &&
(TCPS_HAVEESTABLISHED(tp->t_state) ||
tfo_syn)) {
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (0);
}
}
#endif
rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
tp->rcv_nxt += tlen;
if (tlen &&
((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
(tp->t_fbyte_in == 0)) {
tp->t_fbyte_in = ticks;
if (tp->t_fbyte_in == 0)
tp->t_fbyte_in = 1;
if (tp->t_fbyte_out && tp->t_fbyte_in)
tp->t_flags2 |= TF2_FBYTES_COMPLETE;
}
thflags = th->th_flags & TH_FIN;
KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && appended != mcnt)
counter_fo_release(so->so_rcv.sb_shlim,
mcnt - appended);
#endif
} else {
/*
* XXX: Due to the header drop above "th" is
* theoretically invalid by now. Fortunately
* m_adj() doesn't actually frees any mbufs when
* trimming from the head.
*/
tcp_seq temp = save_start;
thflags = tcp_reass(tp, th, &temp, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) {
if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
/*
* DSACK actually handled in the fastpath
* above.
*/
RACK_OPTS_INC(tcp_sack_path_1);
tcp_update_sack_list(tp, save_start,
save_start + save_tlen);
} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
if ((tp->rcv_numsacks >= 1) &&
(tp->sackblks[0].end == save_start)) {
/*
* Partial overlap, recorded at todrop
* above.
*/
RACK_OPTS_INC(tcp_sack_path_2a);
tcp_update_sack_list(tp,
tp->sackblks[0].start,
tp->sackblks[0].end);
} else {
RACK_OPTS_INC(tcp_sack_path_2b);
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
}
} else if (tlen >= save_tlen) {
/* Update of sackblks. */
RACK_OPTS_INC(tcp_sack_path_3);
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
} else if (tlen > 0) {
RACK_OPTS_INC(tcp_sack_path_4);
tcp_update_dsack_list(tp, save_start,
save_start + tlen);
}
}
} else {
m_freem(m);
thflags &= ~TH_FIN;
}
/*
* If FIN is received ACK the FIN and let the user know that the
* connection is closing.
*/
if (thflags & TH_FIN) {
if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
socantrcvmore(so);
/*
* If connection is half-synchronized (ie NEEDSYN
* flag on) then delay ACK, so it may be piggybacked
* when SYN is sent. Otherwise, since we received a
* FIN then no more input can be expected, send ACK
* now.
*/
if (tp->t_flags & TF_NEEDSYN) {
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
tp->t_flags |= TF_ACKNOW;
}
tp->rcv_nxt++;
}
switch (tp->t_state) {
/*
* In SYN_RECEIVED and ESTABLISHED STATES enter the
* CLOSE_WAIT state.
*/
case TCPS_SYN_RECEIVED:
tp->t_starttime = ticks;
/* FALLTHROUGH */
case TCPS_ESTABLISHED:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_state_change(tp, TCPS_CLOSE_WAIT);
break;
/*
* If still in FIN_WAIT_1 STATE FIN has not been
* acked so enter the CLOSING state.
*/
case TCPS_FIN_WAIT_1:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_state_change(tp, TCPS_CLOSING);
break;
/*
* In FIN_WAIT_2 state enter the TIME_WAIT state,
* starting the time-wait timer, turning off the
* other standard timers.
*/
case TCPS_FIN_WAIT_2:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_twstart(tp);
return (1);
}
}
/*
* Return any desired output.
*/
if ((tp->t_flags & TF_ACKNOW) ||
(sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
rack->r_wanted_output = 1;
}
INP_WLOCK_ASSERT(tp->t_inpcb);
return (0);
}
/*
* Here nothing is really faster, its just that we
* have broken out the fast-data path also just like
* the fast-ack.
*/
static int
rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
{
int32_t nsegs;
int32_t newsize = 0; /* automatic sockbuf scaling */
struct tcp_rack *rack;
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
#endif
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.
*/
u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;
short ostate = 0;
#endif
/*
* If last ACK falls within this segment's sequence numbers, record
* the timestamp. NOTE that the test is modified according to the
* latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
*/
if (__predict_false(th->th_seq != tp->rcv_nxt)) {
return (0);
}
if (__predict_false(tp->snd_nxt != tp->snd_max)) {
return (0);
}
if (tiwin && tiwin != tp->snd_wnd) {
return (0);
}
if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
return (0);
}
if (__predict_false((to->to_flags & TOF_TS) &&
(TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
return (0);
}
if (__predict_false((th->th_ack != tp->snd_una))) {
return (0);
}
if (__predict_false(tlen > sbspace(&so->so_rcv))) {
return (0);
}
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
/*
* This is a pure, in-sequence data packet with nothing on the
* reassembly queue and we have enough buffer space to take it.
*/
nsegs = max(1, m->m_pkthdr.lro_nsegs);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (1);
}
}
#endif
/* Clean receiver SACK report if present */
if (tp->rcv_numsacks)
tcp_clean_sackreport(tp);
KMOD_TCPSTAT_INC(tcps_preddat);
tp->rcv_nxt += tlen;
if (tlen &&
((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
(tp->t_fbyte_in == 0)) {
tp->t_fbyte_in = ticks;
if (tp->t_fbyte_in == 0)
tp->t_fbyte_in = 1;
if (tp->t_fbyte_out && tp->t_fbyte_in)
tp->t_flags2 |= TF2_FBYTES_COMPLETE;
}
/*
* Pull snd_wl1 up to prevent seq wrap relative to th_seq.
*/
tp->snd_wl1 = th->th_seq;
/*
* Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
*/
tp->rcv_up = tp->rcv_nxt;
KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp,
(void *)tcp_saveipgen, &tcp_savetcp, 0);
#endif
newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
/* Add data to socket buffer. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else {
/*
* Set new socket buffer size. Give up when limit is
* reached.
*/
if (newsize)
if (!sbreserve_locked(&so->so_rcv,
newsize, so, NULL))
so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
m_adj(m, drop_hdrlen); /* delayed header drop */
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
ctf_calc_rwin(so, tp);
}
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && mcnt != appended)
counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
#endif
rack_handle_delayed_ack(tp, rack, tlen, 0);
if (tp->snd_una == tp->snd_max)
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
return (1);
}
/*
* This subfunction is used to try to highly optimize the
* fast path. We again allow window updates that are
* in sequence to remain in the fast-path. We also add
* in the __predict's to attempt to help the compiler.
* Note that if we return a 0, then we can *not* process
* it and the caller should push the packet into the
* slow-path.
*/
static int
rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
{
int32_t acked;
int32_t nsegs;
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.
*/
u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;
short ostate = 0;
#endif
int32_t under_pacing = 0;
struct tcp_rack *rack;
if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
/* Old ack, behind (or duplicate to) the last one rcv'd */
return (0);
}
if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
/* Above what we have sent? */
return (0);
}
if (__predict_false(tp->snd_nxt != tp->snd_max)) {
/* We are retransmitting */
return (0);
}
if (__predict_false(tiwin == 0)) {
/* zero window */
return (0);
}
if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
/* We need a SYN or a FIN, unlikely.. */
return (0);
}
if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
/* Timestamp is behind .. old ack with seq wrap? */
return (0);
}
if (__predict_false(IN_RECOVERY(tp->t_flags))) {
/* Still recovering */
return (0);
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->r_ctl.rc_sacked) {
/* We have sack holes on our scoreboard */
return (0);
}
/* Ok if we reach here, we can process a fast-ack */
if (rack->rc_gp_filled &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
under_pacing = 1;
}
nsegs = max(1, m->m_pkthdr.lro_nsegs);
rack_log_ack(tp, to, th);
/* Did the window get updated? */
if (tiwin != tp->snd_wnd) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
}
/* Do we exit persists? */
if ((rack->rc_in_persist != 0) &&
(tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
rack->r_ctl.rc_pace_min_segs))) {
rack_exit_persist(tp, rack, cts);
}
/* Do we enter persists? */
if ((rack->rc_in_persist == 0) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/*
* Here the rwnd is less than
* the pacing size, we are established,
* nothing is outstanding, and there is
* data to send. Enter persists.
*/
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* the timestamp. NOTE that the test is modified according to the
* latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* This is a pure ack for outstanding data.
*/
KMOD_TCPSTAT_INC(tcps_predack);
/*
* "bad retransmit" recovery.
*/
if (tp->t_flags & TF_PREVVALID) {
tp->t_flags &= ~TF_PREVVALID;
if (tp->t_rxtshift == 1 &&
(int)(ticks - tp->t_badrxtwin) < 0)
rack_cong_signal(tp, th, CC_RTO_ERR);
}
/*
* Recalculate the transmit timer / rtt.
*
* Some boxes send broken timestamp replies during the SYN+ACK
* phase, ignore timestamps of 0 or we could calculate a huge RTT
* and blow up the retransmit timer.
*/
acked = BYTES_THIS_ACK(tp, th);
#ifdef TCP_HHOOK
/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
hhook_run_tcp_est_in(tp, th, to);
#endif
KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
sbdrop(&so->so_snd, acked);
if (acked) {
/* assure we are not backed off */
tp->t_rxtshift = 0;
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
/*
* If it is the RXT timer we want to
* stop it, so we can restart a TLP.
*/
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
#ifdef NETFLIX_HTTP_LOGGING
tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
#endif
}
/*
* Let the congestion control algorithm update congestion control
* related information. This typically means increasing the
* congestion window.
*/
rack_ack_received(tp, rack, th, nsegs, CC_ACK, 0);
tp->snd_una = th->th_ack;
if (tp->snd_wnd < ctf_outstanding(tp)) {
/* The peer collapsed the window */
rack_collapsed_window(rack);
} else if (rack->rc_has_collapsed)
rack_un_collapse_window(rack);
/*
* Pull snd_wl2 up to prevent seq wrap relative to th_ack.
*/
tp->snd_wl2 = th->th_ack;
tp->t_dupacks = 0;
m_freem(m);
/* ND6_HINT(tp); *//* Some progress has been made. */
/*
* If all outstanding data are acked, stop retransmit timer,
* otherwise restart timer using current (possibly backed-off)
* value. If process is waiting for space, wakeup/selwakeup/signal.
* If data are ready to send, let tcp_output decide between more
* output or persist.
*/
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp,
(void *)tcp_saveipgen,
&tcp_savetcp, 0);
#endif
if (under_pacing &&
(rack->use_fixed_rate == 0) &&
(rack->in_probe_rtt == 0) &&
rack->rc_gp_dyn_mul &&
rack->rc_always_pace) {
/* Check if we are dragging bottom */
rack_check_bottom_drag(tp, rack, so, acked);
}
if (tp->snd_una == tp->snd_max) {
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
tp->t_acktime = 0;
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
}
/* Wake up the socket if we have room to write more */
sowwakeup(so);
if (sbavail(&so->so_snd)) {
rack->r_wanted_output = 1;
}
return (1);
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t todrop;
int32_t ourfinisacked = 0;
struct tcp_rack *rack;
ctf_calc_rwin(so, tp);
/*
* If the state is SYN_SENT: if seg contains an ACK, but not for our
* SYN, drop the input. if seg contains a RST, then drop the
* connection. if seg does not contain SYN, then drop it. Otherwise
* this is an acceptable SYN segment initialize tp->rcv_nxt and
* tp->irs if seg contains ack then advance tp->snd_una if seg
* contains an ECE and ECN support is enabled, the stream is ECN
* capable. if SYN has been acked change to ESTABLISHED else
* SYN_RCVD state arrange for segment to be acked (eventually)
* continue processing rest of data/controls.
*/
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
TCP_PROBE5(connect__refused, NULL, tp,
mtod(m, const char *), tp, th);
tp = tcp_drop(tp, ECONNREFUSED);
ctf_do_drop(m, tp);
return (1);
}
if (thflags & TH_RST) {
ctf_do_drop(m, tp);
return (1);
}
if (!(thflags & TH_SYN)) {
ctf_do_drop(m, tp);
return (1);
}
tp->irs = th->th_seq;
tcp_rcvseqinit(tp);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (thflags & TH_ACK) {
int tfo_partial = 0;
KMOD_TCPSTAT_INC(tcps_connects);
soisconnected(so);
#ifdef MAC
mac_socketpeer_set_from_mbuf(m, so);
#endif
/* Do window scaling on this connection? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
}
tp->rcv_adv += min(tp->rcv_wnd,
TCP_MAXWIN << tp->rcv_scale);
/*
* If not all the data that was sent in the TFO SYN
* has been acked, resend the remainder right away.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->snd_una != tp->snd_max)) {
tp->snd_nxt = th->th_ack;
tfo_partial = 1;
}
/*
* If there's data, delay ACK; if there's also a FIN ACKNOW
* will be turned on later.
*/
if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
rack->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
rack->rc_dack_toggle = 0;
}
if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
(V_tcp_do_ecn == 1)) {
tp->t_flags2 |= TF2_ECN_PERMIT;
KMOD_TCPSTAT_INC(tcps_ecn_shs);
}
if (SEQ_GT(th->th_ack, tp->snd_una)) {
/*
* We advance snd_una for the
* fast open case. If th_ack is
* acknowledging data beyond
* snd_una we can't just call
* ack-processing since the
* data stream in our send-map
* will start at snd_una + 1 (one
* beyond the SYN). If its just
* equal we don't need to do that
* and there is no send_map.
*/
tp->snd_una++;
}
/*
* Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
* SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
*/
tp->t_starttime = ticks;
if (tp->t_flags & TF_NEEDFIN) {
tcp_state_change(tp, TCPS_FIN_WAIT_1);
tp->t_flags &= ~TF_NEEDFIN;
thflags &= ~TH_SYN;
} else {
tcp_state_change(tp, TCPS_ESTABLISHED);
TCP_PROBE5(connect__established, NULL, tp,
mtod(m, const char *), tp, th);
rack_cc_conn_init(tp);
}
} else {
/*
* Received initial SYN in SYN-SENT[*] state => simultaneous
* open. If segment contains CC option and there is a
* cached CC, apply TAO test. If it succeeds, connection is *
* half-synchronized. Otherwise, do 3-way handshake:
* SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
* there was no CC option, clear cached CC value.
*/
tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
tcp_state_change(tp, TCPS_SYN_RECEIVED);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* Advance th->th_seq to correspond to first data byte. If data,
* trim to stay within window, dropping FIN if necessary.
*/
th->th_seq++;
if (tlen > tp->rcv_wnd) {
todrop = tlen - tp->rcv_wnd;
m_adj(m, -todrop);
tlen = tp->rcv_wnd;
thflags &= ~TH_FIN;
KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
}
tp->snd_wl1 = th->th_seq - 1;
tp->rcv_up = th->th_seq;
/*
* Client side of transaction: already sent SYN and data. If the
* remote host used T/TCP to validate the SYN, our data will be
* ACK'd; if so, enter normal data segment processing in the middle
* of step 5, ack processing. Otherwise, goto step 6.
*/
if (thflags & TH_ACK) {
/* For syn-sent we need to possibly update the rtt */
if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
uint32_t t;
t = tcp_ts_getticks() - to->to_tsecr;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
tcp_rack_xmit_timer(rack, t + 1, 1, (t * HPTS_USEC_IN_MSEC), 0, NULL, 2);
tcp_rack_xmit_timer_commit(rack, tp);
}
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
return (ret_val);
/* We may have changed to FIN_WAIT_1 above */
if (tp->t_state == TCPS_FIN_WAIT_1) {
/*
* In FIN_WAIT_1 STATE in addition to the processing
* for the ESTABLISHED state if our FIN is now
* acknowledged then enter FIN_WAIT_2.
*/
if (ourfinisacked) {
/*
* If we can't receive any more data, then
* closing user can proceed. Starting the
* timer is contrary to the specification,
* but if we don't get a FIN we'll hang
* forever.
*
* XXXjl: we should release the tp also, and
* use a compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
struct tcp_rack *rack;
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->snd_una) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (IS_FASTOPEN(tp->t_flags)) {
/*
* When a TFO connection is in SYN_RECEIVED, the
* only valid packets are the initial SYN, a
* retransmit/copy of the initial SYN (possibly with
* a subset of the original data), a valid ACK, a
* FIN, or a RST.
*/
if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
} else if (thflags & TH_SYN) {
/* non-initial SYN is ignored */
if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
(rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
(rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
ctf_do_drop(m, NULL);
return (0);
}
} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
ctf_do_drop(m, NULL);
return (0);
}
}
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
/*
* In the SYN-RECEIVED state, validate that the packet belongs to
* this connection before trimming the data to fit the receive
* window. Check the sequence number versus IRS since we know the
* sequence numbers haven't wrapped. This is a partial fix for the
* "LAND" DoS attack.
*/
if (SEQ_LT(th->th_seq, tp->irs)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
tp->snd_wnd = tiwin;
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (IS_FASTOPEN(tp->t_flags)) {
rack_cc_conn_init(tp);
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
KMOD_TCPSTAT_INC(tcps_connects);
soisconnected(so);
/* Do window scaling? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
}
/*
* Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* ->
* FIN-WAIT-1
*/
tp->t_starttime = ticks;
if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
tcp_fastopen_decrement_counter(tp->t_tfo_pending);
tp->t_tfo_pending = NULL;
}
if (tp->t_flags & TF_NEEDFIN) {
tcp_state_change(tp, TCPS_FIN_WAIT_1);
tp->t_flags &= ~TF_NEEDFIN;
} else {
tcp_state_change(tp, TCPS_ESTABLISHED);
TCP_PROBE5(accept__established, NULL, tp,
mtod(m, const char *), tp, th);
/*
* TFO connections call cc_conn_init() during SYN
* processing. Calling it again here for such connections
* is not harmless as it would undo the snd_cwnd reduction
* that occurs when a TFO SYN|ACK is retransmitted.
*/
if (!IS_FASTOPEN(tp->t_flags))
rack_cc_conn_init(tp);
}
/*
* Account for the ACK of our SYN prior to
* regular ACK processing below, except for
* simultaneous SYN, which is handled later.
*/
if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
tp->snd_una++;
/*
* If segment contains data or ACK, will call tcp_reass() later; if
* not, do so now to pass queued data to user.
*/
if (tlen == 0 && (thflags & TH_FIN) == 0)
(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
/* For syn-recv we need to possibly update the rtt */
if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
uint32_t t;
t = tcp_ts_getticks() - to->to_tsecr;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
tcp_rack_xmit_timer(rack, t + 1, 1, (t * HPTS_USEC_IN_MSEC), 0, NULL, 2);
tcp_rack_xmit_timer_commit(rack, tp);
}
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (tp->t_state == TCPS_FIN_WAIT_1) {
/* We could have went to FIN_WAIT_1 (or EST) above */
/*
* In FIN_WAIT_1 STATE in addition to the processing for the
* ESTABLISHED state if our FIN is now acknowledged then
* enter FIN_WAIT_2.
*/
if (ourfinisacked) {
/*
* If we can't receive any more data, then closing
* user can proceed. Starting the timer is contrary
* to the specification, but if we don't get a FIN
* we'll hang forever.
*
* XXXjl: we should release the tp also, and use a
* compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
struct tcp_rack *rack;
/*
* Header prediction: check for the two common cases of a
* uni-directional data xfer. If the packet has no control flags,
* is in-sequence, the window didn't change and we're not
* retransmitting, it's a candidate. If the length is zero and the
* ack moved forward, we're the sender side of the xfer. Just free
* the data acked & wake any higher level process that was blocked
* waiting for space. If the length is non-zero and the ack didn't
* move, we're the receiver side. If we're getting packets in-order
* (the reassembly queue is empty), add the data toc The socket
* buffer and note that we need a delayed ack. Make sure that the
* hidden state-flags are also off. Since we check for
* TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
*/
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
__predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
__predict_true(SEGQ_EMPTY(tp)) &&
__predict_true(th->th_seq == tp->rcv_nxt)) {
if (tlen == 0) {
if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
return (0);
}
} else {
if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt, iptos)) {
return (0);
}
}
}
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output= 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
/* State changes only happen in rack_process_data() */
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static int
rack_check_data_after_close(struct mbuf *m,
struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_allow_data_af_clo == 0) {
close_now:
tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
/* tcp_close will kill the inp pre-log the Reset */
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
tp = tcp_close(tp);
KMOD_TCPSTAT_INC(tcps_rcvafterclose);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
return (1);
}
if (sbavail(&so->so_snd) == 0)
goto close_now;
/* Ok we allow data that is ignored and a followup reset */
tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
tp->rcv_nxt = th->th_seq + *tlen;
tp->t_flags2 |= TF2_DROP_AF_DATA;
rack->r_wanted_output = 1;
*tlen = 0;
return (0);
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
/*
* If we can't receive any more data, then closing user can
* proceed. Starting the timer is contrary to the
* specification, but if we don't get a FIN we'll hang
* forever.
*
* XXXjl: we should release the tp also, and use a
* compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output= 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
tcp_twstart(tp);
m_freem(m);
return (1);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* case TCPS_LAST_ACK: Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
tp = tcp_close(tp);
ctf_do_drop(m, tp);
return (1);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
/* Reset receive buffer auto scaling when not in bulk receive mode. */
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) &&
tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static void inline
rack_clear_rate_sample(struct tcp_rack *rack)
{
rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
rack->r_ctl.rack_rs.rs_rtt_tot = 0;
}
static void
rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line)
{
uint64_t bw_est, rate_wanted;
uint32_t tls_seg = 0;
int chged = 0;
uint32_t user_max;
user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
#ifdef KERN_TLS
if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
tls_seg = ctf_get_opt_tls_size(rack->rc_inp->inp_socket, rack->rc_tp->snd_wnd);
if (tls_seg != rack->r_ctl.rc_pace_min_segs)
chged = 1;
rack->r_ctl.rc_pace_min_segs = tls_seg;
} else
#endif
{
if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
chged = 1;
rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
}
if (rack->use_fixed_rate || rack->rc_force_max_seg) {
if (user_max != rack->r_ctl.rc_pace_max_segs)
chged = 1;
}
if (rack->rc_force_max_seg) {
rack->r_ctl.rc_pace_max_segs = user_max;
} else if (rack->use_fixed_rate) {
bw_est = rack_get_bw(rack);
if ((rack->r_ctl.crte == NULL) ||
(bw_est != rack->r_ctl.crte->rate)) {
rack->r_ctl.rc_pace_max_segs = user_max;
} else {
/* We are pacing right at the hardware rate */
uint32_t segsiz;
segsiz = min(ctf_fixed_maxseg(tp),
rack->r_ctl.rc_pace_min_segs);
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
bw_est, segsiz, 0,
rack->r_ctl.crte, NULL);
}
} else if (rack->rc_always_pace) {
if (rack->r_ctl.gp_bw ||
#ifdef NETFLIX_PEAKRATE
rack->rc_tp->t_maxpeakrate ||
#endif
rack->r_ctl.init_rate) {
/* We have a rate of some sort set */
uint32_t orig;
bw_est = rack_get_bw(rack);
orig = rack->r_ctl.rc_pace_max_segs;
rate_wanted = rack_get_output_bw(rack, bw_est, NULL);
if (rate_wanted) {
/* We have something */
rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
rate_wanted,
ctf_fixed_maxseg(rack->rc_tp));
} else
rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
if (orig != rack->r_ctl.rc_pace_max_segs)
chged = 1;
} else if ((rack->r_ctl.gp_bw == 0) &&
(rack->r_ctl.rc_pace_max_segs == 0)) {
/*
* If we have nothing limit us to bursting
* out IW sized pieces.
*/
chged = 1;
rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
}
}
if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
chged = 1;
rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
}
#ifdef KERN_TLS
uint32_t orig;
if (tls_seg != 0) {
orig = rack->r_ctl.rc_pace_max_segs;
if (rack_hw_tls_max_seg > 1) {
rack->r_ctl.rc_pace_max_segs /= tls_seg;
if (rack_hw_tls_max_seg > rack->r_ctl.rc_pace_max_segs)
rack->r_ctl.rc_pace_max_segs = rack_hw_tls_max_seg;
} else {
rack->r_ctl.rc_pace_max_segs = 1;
}
if (rack->r_ctl.rc_pace_max_segs == 0)
rack->r_ctl.rc_pace_max_segs = 1;
rack->r_ctl.rc_pace_max_segs *= tls_seg;
if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
/* We can't go over the max bytes (usually 64k) */
rack->r_ctl.rc_pace_max_segs = ((PACE_MAX_IP_BYTES / tls_seg) * tls_seg);
}
if (orig != rack->r_ctl.rc_pace_max_segs)
chged = 1;
}
#endif
if (chged)
rack_log_type_hrdwtso(tp, rack, tls_seg, rack->rc_inp->inp_socket->so_snd.sb_flags, line, 2);
}
static int
rack_init(struct tcpcb *tp)
{
struct tcp_rack *rack = NULL;
struct rack_sendmap *insret;
uint32_t iwin, snt, us_cts;
tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
if (tp->t_fb_ptr == NULL) {
/*
* We need to allocate memory but cant. The INP and INP_INFO
* locks and they are recusive (happens during setup. So a
* scheme to drop the locks fails :(
*
*/
return (ENOMEM);
}
memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
rack = (struct tcp_rack *)tp->t_fb_ptr;
RB_INIT(&rack->r_ctl.rc_mtree);
TAILQ_INIT(&rack->r_ctl.rc_free);
TAILQ_INIT(&rack->r_ctl.rc_tmap);
rack->rc_tp = tp;
if (tp->t_inpcb) {
rack->rc_inp = tp->t_inpcb;
}
/* Probably not needed but lets be sure */
rack_clear_rate_sample(rack);
rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
if (use_rack_rr)
rack->use_rack_rr = 1;
if (V_tcp_delack_enabled)
tp->t_delayed_ack = 1;
else
tp->t_delayed_ack = 0;
if (rack_enable_shared_cwnd)
rack->rack_enable_scwnd = 1;
rack->rc_user_set_max_segs = rack_hptsi_segments;
rack->rc_force_max_seg = 0;
if (rack_use_imac_dack)
rack->rc_dack_mode = 1;
rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
rack->r_ctl.rc_prop_reduce = rack_use_proportional_reduce;
rack->r_ctl.rc_prop_rate = rack_proportional_rate;
rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
rack->r_ctl.rc_early_recovery = rack_early_recovery;
rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
rack->r_ctl.rc_highest_us_rtt = 0;
if (rack_disable_prr)
rack->rack_no_prr = 1;
if (rack_gp_no_rec_chg)
rack->rc_gp_no_rec_chg = 1;
rack->rc_always_pace = rack_pace_every_seg;
if (rack_enable_mqueue_for_nonpaced)
rack->r_mbuf_queue = 1;
else
rack->r_mbuf_queue = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
rack_set_pace_segments(tp, rack, __LINE__);
if (rack_limits_scwnd)
rack->r_limit_scw = 1;
else
rack->r_limit_scw = 0;
rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
rack->r_ctl.rc_min_to = rack_min_to;
microuptime(&rack->r_ctl.act_rcv_time);
rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
rack->r_running_late = 0;
rack->r_running_early = 0;
rack->rc_init_win = rack_default_init_window;
rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
if (rack_do_dyn_mul) {
/* When dynamic adjustment is on CA needs to start at 100% */
rack->rc_gp_dyn_mul = 1;
if (rack_do_dyn_mul >= 100)
rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
} else
rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
rack_probertt_filter_life);
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_of_last_probertt = us_cts;
rack->r_ctl.rc_time_probertt_starts = 0;
/* Do we force on detection? */
#ifdef NETFLIX_EXP_DETECTION
if (tcp_force_detection)
rack->do_detection = 1;
else
#endif
rack->do_detection = 0;
if (rack_non_rxt_use_cr)
rack->rack_rec_nonrxt_use_cr = 1;
if (tp->snd_una != tp->snd_max) {
/* Create a send map for the current outstanding data */
struct rack_sendmap *rsm;
rsm = rack_alloc(rack);
if (rsm == NULL) {
uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
return (ENOMEM);
}
rsm->r_flags = RACK_OVERMAX;
rsm->r_tim_lastsent[0] = rack->r_ctl.rc_tlp_rxt_last_time;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->r_start = tp->snd_una;
rsm->r_end = tp->snd_max;
rsm->usec_orig_send = us_cts;
rsm->r_dupack = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
insret, rack, rsm);
}
#endif
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
}
/* Cancel the GP measurement in progress */
tp->t_flags &= ~TF_GPUTINPROG;
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
iwin = rc_init_window(rack);
if (snt < iwin) {
/* We are not past the initial window
* so we need to make sure cwnd is
* correct.
*/
if (tp->snd_cwnd < iwin)
tp->snd_cwnd = iwin;
/*
* If we are within the initial window
* we want ssthresh to be unlimited. Setting
* it to the rwnd (which the default stack does
* and older racks) is not really a good idea
* since we want to be in SS and grow both the
* cwnd and the rwnd (via dynamic rwnd growth). If
* we set it to the rwnd then as the peer grows its
* rwnd we will be stuck in CA and never hit SS.
*
* Its far better to raise it up high (this takes the
* risk that there as been a loss already, probably
* we should have an indicator in all stacks of loss
* but we don't), but considering the normal use this
* is a risk worth taking. The consequences of not
* hitting SS are far worse than going one more time
* into it early on (before we have sent even a IW).
* It is highly unlikely that we will have had a loss
* before getting the IW out.
*/
tp->snd_ssthresh = 0xffffffff;
}
rack_stop_all_timers(tp);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
rack_log_rtt_shrinks(rack, us_cts, 0,
__LINE__, RACK_RTTS_INIT);
return (0);
}
static int
rack_handoff_ok(struct tcpcb *tp)
{
if ((tp->t_state == TCPS_CLOSED) ||
(tp->t_state == TCPS_LISTEN)) {
/* Sure no problem though it may not stick */
return (0);
}
if ((tp->t_state == TCPS_SYN_SENT) ||
(tp->t_state == TCPS_SYN_RECEIVED)) {
/*
* We really don't know you have to get to ESTAB or beyond
* to tell.
*/
return (EAGAIN);
}
if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
return (0);
}
/*
* If we reach here we don't do SACK on this connection so we can
* never do rack.
*/
return (EINVAL);
}
static void
rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
{
if (tp->t_fb_ptr) {
struct tcp_rack *rack;
struct rack_sendmap *rsm, *nrsm, *rm;
rack = (struct tcp_rack *)tp->t_fb_ptr;
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
uint32_t limit;
if (rack->r_limit_scw)
limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
else
limit = 0;
tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
rack->r_ctl.rc_scw_index,
limit);
rack->r_ctl.rc_scw = NULL;
}
#endif
/* rack does not use force data but other stacks may clear it */
tp->t_flags &= ~TF_FORCEDATA;
if (tp->t_inpcb) {
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
#ifdef TCP_BLACKBOX
tcp_log_flowend(tp);
#endif
RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (rm != rsm) {
panic("At fini, rack:%p rsm:%p rm:%p",
rack, rsm, rm);
}
#endif
uma_zfree(rack_zone, rsm);
}
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
while (rsm) {
TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
uma_zfree(rack_zone, rsm);
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
}
rack->rc_free_cnt = 0;
uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
}
/* Cancel the GP measurement in progress */
tp->t_flags &= ~TF_GPUTINPROG;
/* Make sure snd_nxt is correctly set */
tp->snd_nxt = tp->snd_max;
}
static void
rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
{
switch (tp->t_state) {
case TCPS_SYN_SENT:
rack->r_state = TCPS_SYN_SENT;
rack->r_substate = rack_do_syn_sent;
break;
case TCPS_SYN_RECEIVED:
rack->r_state = TCPS_SYN_RECEIVED;
rack->r_substate = rack_do_syn_recv;
break;
case TCPS_ESTABLISHED:
rack_set_pace_segments(tp, rack, __LINE__);
rack->r_state = TCPS_ESTABLISHED;
rack->r_substate = rack_do_established;
break;
case TCPS_CLOSE_WAIT:
rack->r_state = TCPS_CLOSE_WAIT;
rack->r_substate = rack_do_close_wait;
break;
case TCPS_FIN_WAIT_1:
rack->r_state = TCPS_FIN_WAIT_1;
rack->r_substate = rack_do_fin_wait_1;
break;
case TCPS_CLOSING:
rack->r_state = TCPS_CLOSING;
rack->r_substate = rack_do_closing;
break;
case TCPS_LAST_ACK:
rack->r_state = TCPS_LAST_ACK;
rack->r_substate = rack_do_lastack;
break;
case TCPS_FIN_WAIT_2:
rack->r_state = TCPS_FIN_WAIT_2;
rack->r_substate = rack_do_fin_wait_2;
break;
case TCPS_LISTEN:
case TCPS_CLOSED:
case TCPS_TIME_WAIT:
default:
break;
};
}
static void
rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
{
/*
* We received an ack, and then did not
* call send or were bounced out due to the
* hpts was running. Now a timer is up as well, is
* it the right timer?
*/
struct rack_sendmap *rsm;
int tmr_up;
tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
return;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
(tmr_up == PACE_TMR_RXT)) {
/* Should be an RXT */
return;
}
if (rsm == NULL) {
/* Nothing outstanding? */
if (tp->t_flags & TF_DELACK) {
if (tmr_up == PACE_TMR_DELACK)
/* We are supposed to have delayed ack up and we do */
return;
} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
/*
* if we hit enobufs then we would expect the possiblity
* of nothing outstanding and the RXT up (and the hptsi timer).
*/
return;
} else if (((V_tcp_always_keepalive ||
rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)) &&
(tmr_up == PACE_TMR_KEEP) &&
(tp->snd_max == tp->snd_una)) {
/* We should have keep alive up and we do */
return;
}
}
if (SEQ_GT(tp->snd_max, tp->snd_una) &&
((tmr_up == PACE_TMR_TLP) ||
(tmr_up == PACE_TMR_RACK) ||
(tmr_up == PACE_TMR_RXT))) {
/*
* Either a Rack, TLP or RXT is fine if we
* have outstanding data.
*/
return;
} else if (tmr_up == PACE_TMR_DELACK) {
/*
* If the delayed ack was going to go off
* before the rtx/tlp/rack timer were going to
* expire, then that would be the timer in control.
* Note we don't check the time here trusting the
* code is correct.
*/
return;
}
/*
* Ok the timer originally started is not what we want now.
* We will force the hpts to be stopped if any, and restart
* with the slot set to what was in the saved slot.
*/
if (rack->rc_inp->inp_in_hpts) {
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
uint32_t us_cts;
us_cts = tcp_get_usecs(NULL);
if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
rack->r_early = 1;
rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
}
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
}
static int
rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
int32_t nxt_pkt, struct timeval *tv)
{
int32_t thflags, retval, did_out = 0;
int32_t way_out = 0;
uint32_t cts;
uint32_t tiwin;
struct timespec ts;
struct tcpopt to;
struct tcp_rack *rack;
struct rack_sendmap *rsm;
int32_t prev_state = 0;
uint32_t us_cts;
/*
* tv passed from common code is from either M_TSTMP_LRO or
* tcp_get_usecs() if no LRO m_pkthdr timestamp is present. The
* rack_pacing stack assumes tv always refers to 'now', so we overwrite
* tv here to guarantee that.
*/
if (m->m_flags & M_TSTMP_LRO)
tcp_get_usecs(tv);
cts = tcp_tv_to_mssectick(tv);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if ((m->m_flags & M_TSTMP) ||
(m->m_flags & M_TSTMP_LRO)) {
mbuf_tstmp2timespec(m, &ts);
rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
} else
rack->r_ctl.act_rcv_time = *tv;
kern_prefetch(rack, &prev_state);
prev_state = 0;
thflags = th->th_flags;
NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(tp->t_inpcb);
KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
__func__));
KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
__func__));
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval ltv;
#ifdef NETFLIX_HTTP_LOGGING
struct http_sendfile_track *http_req;
if (SEQ_GT(th->th_ack, tp->snd_una)) {
http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
} else {
http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
}
#endif
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
if (rack->rack_no_prr == 0)
log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
else
log.u_bbr.flex1 = 0;
log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
log.u_bbr.flex3 = m->m_flags;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
if (m->m_flags & M_TSTMP) {
/* Record the hardware timestamp if present */
mbuf_tstmp2timespec(m, &ts);
ltv.tv_sec = ts.tv_sec;
ltv.tv_usec = ts.tv_nsec / 1000;
log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
} else if (m->m_flags & M_TSTMP_LRO) {
/* Record the LRO the arrival timestamp */
mbuf_tstmp2timespec(m, &ts);
ltv.tv_sec = ts.tv_sec;
ltv.tv_usec = ts.tv_nsec / 1000;
log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
}
log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
/* Log the rcv time */
log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
#ifdef NETFLIX_HTTP_LOGGING
log.u_bbr.applimited = tp->t_http_closed;
log.u_bbr.applimited <<= 8;
log.u_bbr.applimited |= tp->t_http_open;
log.u_bbr.applimited <<= 8;
log.u_bbr.applimited |= tp->t_http_req;
if (http_req) {
/* Copy out any client req info */
/* seconds */
log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
/* useconds */
log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
log.u_bbr.rttProp = http_req->timestamp;
log.u_bbr.cur_del_rate = http_req->start;
if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
log.u_bbr.flex8 |= 1;
} else {
log.u_bbr.flex8 |= 2;
log.u_bbr.bw_inuse = http_req->end;
}
log.u_bbr.flex6 = http_req->start_seq;
if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
log.u_bbr.flex8 |= 4;
log.u_bbr.epoch = http_req->end_seq;
}
}
#endif
TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
tlen, &log, true, &ltv);
}
if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
way_out = 4;
retval = 0;
goto done_with_input;
}
/*
* If a segment with the ACK-bit set arrives in the SYN-SENT state
* check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
*/
if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return(1);
}
/*
* Segment received on connection. Reset idle time and keep-alive
* timer. XXX: This should be done after segment validation to
* ignore broken/spoofed segs.
*/
if (tp->t_idle_reduce &&
(tp->snd_max == tp->snd_una) &&
((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
counter_u64_add(rack_input_idle_reduces, 1);
rack_cc_after_idle(rack, tp);
}
tp->t_rcvtime = ticks;
/*
* Unscale the window into a 32-bit value. For the SYN_SENT state
* the scale is zero.
*/
tiwin = th->th_win << tp->snd_scale;
#ifdef STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
#endif
if (tiwin > rack->r_ctl.rc_high_rwnd)
rack->r_ctl.rc_high_rwnd = tiwin;
/*
* TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
* this to occur after we've validated the segment.
*/
if (tp->t_flags2 & TF2_ECN_PERMIT) {
if (thflags & TH_CWR) {
tp->t_flags2 &= ~TF2_ECN_SND_ECE;
tp->t_flags |= TF_ACKNOW;
}
switch (iptos & IPTOS_ECN_MASK) {
case IPTOS_ECN_CE:
tp->t_flags2 |= TF2_ECN_SND_ECE;
KMOD_TCPSTAT_INC(tcps_ecn_ce);
break;
case IPTOS_ECN_ECT0:
KMOD_TCPSTAT_INC(tcps_ecn_ect0);
break;
case IPTOS_ECN_ECT1:
KMOD_TCPSTAT_INC(tcps_ecn_ect1);
break;
}
/* Process a packet differently from RFC3168. */
cc_ecnpkt_handler(tp, th, iptos);
/* Congestion experienced. */
if (thflags & TH_ECE) {
rack_cong_signal(tp, th, CC_ECN);
}
}
/*
* Parse options on any incoming segment.
*/
tcp_dooptions(&to, (u_char *)(th + 1),
(th->th_off << 2) - sizeof(struct tcphdr),
(thflags & TH_SYN) ? TO_SYN : 0);
/*
* If echoed timestamp is later than the current time, fall back to
* non RFC1323 RTT calculation. Normalize timestamp if syncookies
* were used when this connection was established.
*/
if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
to.to_tsecr -= tp->ts_offset;
if (TSTMP_GT(to.to_tsecr, cts))
to.to_tsecr = 0;
}
/*
* If its the first time in we need to take care of options and
* verify we can do SACK for rack!
*/
if (rack->r_state == 0) {
/* Should be init'd by rack_init() */
KASSERT(rack->rc_inp != NULL,
("%s: rack->rc_inp unexpectedly NULL", __func__));
if (rack->rc_inp == NULL) {
rack->rc_inp = tp->t_inpcb;
}
/*
* Process options only when we get SYN/ACK back. The SYN
* case for incoming connections is handled in tcp_syncache.
* According to RFC1323 the window field in a SYN (i.e., a
* <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
* this is traditional behavior, may need to be cleaned up.
*/
if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
/* Handle parallel SYN for ECN */
if (!(thflags & TH_ACK) &&
((thflags & (TH_CWR | TH_ECE)) == (TH_CWR | TH_ECE)) &&
((V_tcp_do_ecn == 1) || (V_tcp_do_ecn == 2))) {
tp->t_flags2 |= TF2_ECN_PERMIT;
tp->t_flags2 |= TF2_ECN_SND_ECE;
TCPSTAT_INC(tcps_ecn_shs);
}
if ((to.to_flags & TOF_SCALE) &&
(tp->t_flags & TF_REQ_SCALE)) {
tp->t_flags |= TF_RCVD_SCALE;
tp->snd_scale = to.to_wscale;
} else
tp->t_flags &= ~TF_REQ_SCALE;
/*
* Initial send window. It will be updated with the
* next incoming segment to the scaled value.
*/
tp->snd_wnd = th->th_win;
if ((to.to_flags & TOF_TS) &&
(tp->t_flags & TF_REQ_TSTMP)) {
tp->t_flags |= TF_RCVD_TSTMP;
tp->ts_recent = to.to_tsval;
tp->ts_recent_age = cts;
} else
tp->t_flags &= ~TF_REQ_TSTMP;
if (to.to_flags & TOF_MSS)
tcp_mss(tp, to.to_mss);
if ((tp->t_flags & TF_SACK_PERMIT) &&
(to.to_flags & TOF_SACKPERM) == 0)
tp->t_flags &= ~TF_SACK_PERMIT;
if (IS_FASTOPEN(tp->t_flags)) {
if (to.to_flags & TOF_FASTOPEN) {
uint16_t mss;
if (to.to_flags & TOF_MSS)
mss = to.to_mss;
else
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
mss = TCP6_MSS;
else
mss = TCP_MSS;
tcp_fastopen_update_cache(tp, mss,
to.to_tfo_len, to.to_tfo_cookie);
} else
tcp_fastopen_disable_path(tp);
}
}
/*
* At this point we are at the initial call. Here we decide
* if we are doing RACK or not. We do this by seeing if
* TF_SACK_PERMIT is set and the sack-not-required is clear.
* The code now does do dup-ack counting so if you don't
* switch back you won't get rack & TLP, but you will still
* get this stack.
*/
if ((rack_sack_not_required == 0) &&
((tp->t_flags & TF_SACK_PERMIT) == 0)) {
tcp_switch_back_to_default(tp);
(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
tlen, iptos);
return (1);
}
/* Set the flag */
rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
tcp_set_hpts(tp->t_inpcb);
sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
}
if (thflags & TH_FIN)
tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
if ((rack->rc_gp_dyn_mul) &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/* Check in on probertt */
rack_check_probe_rtt(rack, us_cts);
}
if (rack->forced_ack) {
uint32_t us_rtt;
/*
* A persist or keep-alive was forced out, update our
* min rtt time. Note we do not worry about lost
* retransmissions since KEEP-ALIVES and persists
* are usually way long on times of sending (though
* if we were really paranoid or worried we could
* at least use timestamps if available to validate).
*/
rack->forced_ack = 0;
us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
if (us_rtt == 0)
us_rtt = 1;
rack_log_rtt_upd(tp, rack, us_rtt, 0, NULL, 3);
rack_apply_updated_usrtt(rack, us_rtt, us_cts);
}
/*
* This is the one exception case where we set the rack state
* always. All other times (timers etc) we must have a rack-state
* set (so we assure we have done the checks above for SACK).
*/
rack->r_ctl.rc_rcvtime = cts;
if (rack->r_state != tp->t_state)
rack_set_state(tp, rack);
if (SEQ_GT(th->th_ack, tp->snd_una) &&
(rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
kern_prefetch(rsm, &prev_state);
prev_state = rack->r_state;
rack_clear_rate_sample(rack);
retval = (*rack->r_substate) (m, th, so,
tp, &to, drop_hdrlen,
tlen, tiwin, thflags, nxt_pkt, iptos);
#ifdef INVARIANTS
if ((retval == 0) &&
(tp->t_inpcb == NULL)) {
panic("retval:%d tp:%p t_inpcb:NULL state:%d",
retval, tp, prev_state);
}
#endif
if (retval == 0) {
/*
* If retval is 1 the tcb is unlocked and most likely the tp
* is gone.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
if ((rack->rc_gp_dyn_mul) &&
(rack->rc_always_pace) &&
(rack->use_fixed_rate == 0) &&
rack->in_probe_rtt &&
(rack->r_ctl.rc_time_probertt_starts == 0)) {
/*
* If we are going for target, lets recheck before
* we output.
*/
rack_check_probe_rtt(rack, us_cts);
}
if (rack->set_pacing_done_a_iw == 0) {
/* How much has been acked? */
if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
/* We have enough to set in the pacing segment size */
rack->set_pacing_done_a_iw = 1;
rack_set_pace_segments(tp, rack, __LINE__);
}
}
tcp_rack_xmit_timer_commit(rack, tp);
if (nxt_pkt == 0) {
if (rack->r_wanted_output != 0) {
do_output_now:
did_out = 1;
(void)tp->t_fb->tfb_tcp_output(tp);
}
rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
}
if ((nxt_pkt == 0) &&
((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
(SEQ_GT(tp->snd_max, tp->snd_una) ||
(tp->t_flags & TF_DELACK) ||
((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)))) {
/* We could not send (probably in the hpts but stopped the timer earlier)? */
if ((tp->snd_max == tp->snd_una) &&
((tp->t_flags & TF_DELACK) == 0) &&
(rack->rc_inp->inp_in_hpts) &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/* keep alive not needed if we are hptsi output yet */
;
} else {
int late = 0;
if (rack->rc_inp->inp_in_hpts) {
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
us_cts = tcp_get_usecs(NULL);
if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
rack->r_early = 1;
rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
} else
late = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
}
if (late && (did_out == 0)) {
/*
* We are late in the sending
* and we did not call the output
* (this probably should not happen).
*/
goto do_output_now;
}
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
}
way_out = 1;
} else if (nxt_pkt == 0) {
/* Do we have the correct timer running? */
rack_timer_audit(tp, rack, &so->so_snd);
way_out = 2;
}
done_with_input:
rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out);
if (did_out)
rack->r_wanted_output = 0;
#ifdef INVARIANTS
if (tp->t_inpcb == NULL) {
panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
did_out,
retval, tp, prev_state);
}
#endif
}
return (retval);
}
void
rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
{
struct timeval tv;
/* First lets see if we have old packets */
if (tp->t_in_pkt) {
if (ctf_do_queued_segments(so, tp, 1)) {
m_freem(m);
return;
}
}
if (m->m_flags & M_TSTMP_LRO) {
tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
} else {
/* Should not be should we kassert instead? */
tcp_get_usecs(&tv);
}
if(rack_do_segment_nounlock(m, th, so, tp,
drop_hdrlen, tlen, iptos, 0, &tv) == 0)
INP_WUNLOCK(tp->t_inpcb);
}
struct rack_sendmap *
tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
{
struct rack_sendmap *rsm = NULL;
int32_t idx;
uint32_t srtt = 0, thresh = 0, ts_low = 0;
/* Return the next guy to be re-transmitted */
if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
return (NULL);
}
if (tp->t_flags & TF_SENTFIN) {
/* retran the end FIN? */
return (NULL);
}
/* ok lets look at this one */
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
goto check_it;
}
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL) {
return (NULL);
}
check_it:
if (rsm->r_flags & RACK_ACKED) {
return (NULL);
}
if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
(rsm->r_dupack < DUP_ACK_THRESHOLD)) {
/* Its not yet ready */
return (NULL);
}
srtt = rack_grab_rtt(tp, rack);
idx = rsm->r_rtr_cnt - 1;
ts_low = rsm->r_tim_lastsent[idx];
thresh = rack_calc_thresh_rack(rack, srtt, tsused);
if ((tsused == ts_low) ||
(TSTMP_LT(tsused, ts_low))) {
/* No time since sending */
return (NULL);
}
if ((tsused - ts_low) < thresh) {
/* It has not been long enough yet */
return (NULL);
}
if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
((rsm->r_flags & RACK_SACK_PASSED) &&
(rack->sack_attack_disable == 0))) {
/*
* We have passed the dup-ack threshold <or>
* a SACK has indicated this is missing.
* Note that if you are a declared attacker
* it is only the dup-ack threshold that
* will cause retransmits.
*/
/* log retransmit reason */
rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
return (rsm);
}
return (NULL);
}
static void
rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
int line, struct rack_sendmap *rsm)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = slot;
log.u_bbr.flex2 = len;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.use_lt_bw = rack->app_limited_needs_set;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw = rack->rc_gp_filled;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
log.u_bbr.pkt_epoch = line;
log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.bw_inuse = bw_est;
log.u_bbr.delRate = bw;
if (rack->r_ctl.gp_bw == 0)
log.u_bbr.cur_del_rate = 0;
else
log.u_bbr.cur_del_rate = rack_get_bw(rack);
log.u_bbr.rttProp = len_time;
log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
/* We are in slow start */
log.u_bbr.flex7 = 1;
} else {
/* we are on congestion avoidance */
log.u_bbr.flex7 = 0;
}
log.u_bbr.flex8 = method;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSI_CALC, 0,
0, &log, false, &tv);
}
}
static uint32_t
rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
{
uint32_t new_tso, user_max;
user_max = rack->rc_user_set_max_segs * mss;
if (rack->rc_force_max_seg) {
return (user_max);
}
if (rack->use_fixed_rate &&
((rack->r_ctl.crte == NULL) ||
(bw != rack->r_ctl.crte->rate))) {
/* Use the user mss since we are not exactly matched */
return (user_max);
}
new_tso = tcp_get_pacing_burst_size(bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
if (new_tso > user_max)
new_tso = user_max;
return(new_tso);
}
static void
rack_log_hdwr_pacing(struct tcp_rack *rack, const struct ifnet *ifp,
uint64_t rate, uint64_t hw_rate, int line,
int error)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
log.u_bbr.flex3 = (((uint64_t)ifp >> 32) & 0x00000000ffffffff);
log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.bw_inuse = rate;
log.u_bbr.flex5 = line;
log.u_bbr.flex6 = error;
log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex8 = rack->use_fixed_rate;
log.u_bbr.flex8 <<= 1;
log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HDWR_PACE, 0,
0, &log, false, &tv);
}
}
static int32_t
pace_to_fill_cwnd(struct tcp_rack *rack, int32_t slot, uint32_t len, uint32_t segsiz)
{
uint64_t lentim, fill_bw;
/* Lets first see if we are full, if so continue with normal rate */
if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
return (slot);
if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
return (slot);
if (rack->r_ctl.rc_last_us_rtt == 0)
return (slot);
if (rack->rc_pace_fill_if_rttin_range &&
(rack->r_ctl.rc_last_us_rtt >=
(get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
/* The rtt is huge, N * smallest, lets not fill */
return (slot);
}
/*
* first lets calculate the b/w based on the last us-rtt
* and the sndwnd.
*/
fill_bw = rack->r_ctl.cwnd_to_use;
/* Take the rwnd if its smaller */
if (fill_bw > rack->rc_tp->snd_wnd)
fill_bw = rack->rc_tp->snd_wnd;
fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
/* We are below the min b/w */
if (fill_bw < RACK_MIN_BW)
return (slot);
/*
* Ok fill_bw holds our mythical b/w to fill the cwnd
* in a rtt, what does that time wise equate too?
*/
lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
lentim /= fill_bw;
if (lentim < slot) {
rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
0, lentim, 12, __LINE__, NULL);
return ((int32_t)lentim);
} else
return (slot);
}
static int32_t
rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
{
struct rack_sendmap *lrsm;
int32_t slot = 0;
int err;
if (rack->rc_always_pace == 0) {
/*
* We use the most optimistic possible cwnd/srtt for
* sending calculations. This will make our
* calculation anticipate getting more through
* quicker then possible. But thats ok we don't want
* the peer to have a gap in data sending.
*/
uint32_t srtt, cwnd, tr_perms = 0;
int32_t reduce = 0;
old_method:
/*
* We keep no precise pacing with the old method
* instead we use the pacer to mitigate bursts.
*/
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
if (rack->r_ctl.rc_rack_min_rtt)
srtt = rack->r_ctl.rc_rack_min_rtt;
else
srtt = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT));
if (rack->r_ctl.rc_rack_largest_cwnd)
cwnd = rack->r_ctl.rc_rack_largest_cwnd;
else
cwnd = rack->r_ctl.cwnd_to_use;
tr_perms = cwnd / srtt;
if (tr_perms == 0) {
tr_perms = ctf_fixed_maxseg(tp);
}
/*
* Calculate how long this will take to drain, if
* the calculation comes out to zero, thats ok we
* will use send_a_lot to possibly spin around for
* more increasing tot_len_this_send to the point
* that its going to require a pace, or we hit the
* cwnd. Which in that case we are just waiting for
* a ACK.
*/
slot = len / tr_perms;
/* Now do we reduce the time so we don't run dry? */
if (slot && rack_slot_reduction) {
reduce = (slot / rack_slot_reduction);
if (reduce < slot) {
slot -= reduce;
} else
slot = 0;
}
slot *= HPTS_USEC_IN_MSEC;
if (rsm == NULL) {
/*
* We always consider ourselves app limited with old style
* that are not retransmits. This could be the initial
* measurement, but thats ok its all setup and specially
* handled. If another send leaks out, then that too will
* be mark app-limited.
*/
lrsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (lrsm && ((lrsm->r_flags & RACK_APP_LIMITED) == 0)) {
rack->r_ctl.rc_first_appl = lrsm;
lrsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
}
rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL);
} else {
uint64_t bw_est, res, lentim, rate_wanted;
uint32_t orig_val, srtt, segs, oh;
if ((rack->r_rr_config == 1) && rsm) {
return (rack->r_ctl.rc_min_to * HPTS_USEC_IN_MSEC);
}
if (rack->use_fixed_rate) {
rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
} else if ((rack->r_ctl.init_rate == 0) &&
#ifdef NETFLIX_PEAKRATE
(rack->rc_tp->t_maxpeakrate == 0) &&
#endif
(rack->r_ctl.gp_bw == 0)) {
/* no way to yet do an estimate */
bw_est = rate_wanted = 0;
} else {
bw_est = rack_get_bw(rack);
rate_wanted = rack_get_output_bw(rack, bw_est, rsm);
}
if ((bw_est == 0) || (rate_wanted == 0)) {
/*
* No way yet to make a b/w estimate or
* our raise is set incorrectly.
*/
goto old_method;
}
/* We need to account for all the overheads */
segs = (len + segsiz - 1) / segsiz;
/*
* We need the diff between 1514 bytes (e-mtu with e-hdr)
* and how much data we put in each packet. Yes this
* means we may be off if we are larger than 1500 bytes
* or smaller. But this just makes us more conservative.
*/
if (ETHERNET_SEGMENT_SIZE > segsiz)
oh = ETHERNET_SEGMENT_SIZE - segsiz;
else
oh = 0;
segs *= oh;
lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
res = lentim / rate_wanted;
slot = (uint32_t)res;
orig_val = rack->r_ctl.rc_pace_max_segs;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
#ifdef KERN_TLS
/* For TLS we need to override this, possibly */
if (rack->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
}
#endif
/* Did we change the TSO size, if so log it */
if (rack->r_ctl.rc_pace_max_segs != orig_val)
rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL);
if ((rack->rc_pace_to_cwnd) &&
(rack->in_probe_rtt == 0) &&
(IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
/*
* We want to pace at our rate *or* faster to
* fill the cwnd to the max if its not full.
*/
slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz);
}
if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
(rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
if ((rack->rack_hdw_pace_ena) &&
(rack->rack_hdrw_pacing == 0) &&
(rack->rack_attempt_hdwr_pace == 0)) {
/*
* Lets attempt to turn on hardware pacing
* if we can.
*/
rack->rack_attempt_hdwr_pace = 1;
rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted,
RS_PACING_GEQ,
&err);
if (rack->r_ctl.crte) {
rack->rack_hdrw_pacing = 1;
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(rate_wanted, segsiz,
0, rack->r_ctl.crte,
NULL);
rack_log_hdwr_pacing(rack, rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted, rack->r_ctl.crte->rate, __LINE__,
err);
}
} else if (rack->rack_hdrw_pacing &&
(rack->r_ctl.crte->rate != rate_wanted)) {
/* Do we need to adjust our rate? */
const struct tcp_hwrate_limit_table *nrte;
nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
rack->rc_tp,
rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted,
RS_PACING_GEQ,
&err);
if (nrte == NULL) {
/* Lost the rate */
rack->rack_hdrw_pacing = 0;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else if (nrte != rack->r_ctl.crte) {
rack->r_ctl.crte = nrte;
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(rate_wanted,
segsiz, 0,
rack->r_ctl.crte,
NULL);
rack_log_hdwr_pacing(rack, rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted, rack->r_ctl.crte->rate, __LINE__,
err);
}
}
}
if (rack_limit_time_with_srtt &&
(rack->use_fixed_rate == 0) &&
#ifdef NETFLIX_PEAKRATE
(rack->rc_tp->t_maxpeakrate == 0) &&
#endif
(rack->rack_hdrw_pacing == 0)) {
/*
* Sanity check, we do not allow the pacing delay
* to be longer than the SRTT of the path. If it is
* a slow path, then adding a packet should increase
* the RTT and compensate for this i.e. the srtt will
* be greater so the allowed pacing time will be greater.
*
* Note this restriction is not for where a peak rate
* is set, we are doing fixed pacing or hardware pacing.
*/
if (rack->rc_tp->t_srtt)
srtt = (TICKS_2_USEC(rack->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
else
srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC; /* its in ms convert */
if (srtt < slot) {
rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL);
slot = srtt;
}
}
rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm);
}
if (slot)
counter_u64_add(rack_calc_nonzero, 1);
else
counter_u64_add(rack_calc_zero, 1);
return (slot);
}
static void
rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq startseq, uint32_t sb_offset)
{
struct rack_sendmap *my_rsm = NULL;
struct rack_sendmap fe;
if (tp->t_state < TCPS_ESTABLISHED) {
/*
* We don't start any measurements if we are
* not at least established.
*/
return;
}
tp->t_flags |= TF_GPUTINPROG;
rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
tp->gput_seq = startseq;
rack->app_limited_needs_set = 0;
if (rack->in_probe_rtt)
rack->measure_saw_probe_rtt = 1;
else if ((rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
if (rack->rc_gp_filled)
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
else {
/* Special case initial measurement */
rack->r_ctl.rc_gp_output_ts = tp->gput_ts = tcp_get_usecs(NULL);
}
/*
* We take a guess out into the future,
* if we have no measurement and no
* initial rate, we measure the first
* initial-windows worth of data to
* speed up getting some GP measurement and
* thus start pacing.
*/
if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
rack->app_limited_needs_set = 1;
tp->gput_ack = startseq + max(rc_init_window(rack),
(MIN_GP_WIN * ctf_fixed_maxseg(tp)));
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
0,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
return;
}
if (sb_offset) {
/*
* We are out somewhere in the sb
* can we use the already outstanding data?
*/
if (rack->r_ctl.rc_app_limited_cnt == 0) {
/*
* Yes first one is good and in this case
* the tp->gput_ts is correctly set based on
* the last ack that arrived (no need to
* set things up when an ack comes in).
*/
my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if ((my_rsm == NULL) ||
(my_rsm->r_rtr_cnt != 1)) {
/* retransmission? */
goto use_latest;
}
} else {
if (rack->r_ctl.rc_first_appl == NULL) {
/*
* If rc_first_appl is NULL
* then the cnt should be 0.
* This is probably an error, maybe
* a KASSERT would be approprate.
*/
goto use_latest;
}
/*
* If we have a marker pointer to the last one that is
* app limited we can use that, but we need to set
* things up so that when it gets ack'ed we record
* the ack time (if its not already acked).
*/
rack->app_limited_needs_set = 1;
/*
* We want to get to the rsm that is either
* next with space i.e. over 1 MSS or the one
* after that (after the app-limited).
*/
my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
rack->r_ctl.rc_first_appl);
if (my_rsm) {
if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
/* Have to use the next one */
my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
my_rsm);
else {
/* Use after the first MSS of it is acked */
tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
goto start_set;
}
}
if ((my_rsm == NULL) ||
(my_rsm->r_rtr_cnt != 1)) {
/*
* Either its a retransmit or
* the last is the app-limited one.
*/
goto use_latest;
}
}
tp->gput_seq = my_rsm->r_start;
start_set:
if (my_rsm->r_flags & RACK_ACKED) {
/*
* This one has been acked use the arrival ack time
*/
tp->gput_ts = my_rsm->r_ack_arrival;
rack->app_limited_needs_set = 0;
}
rack->r_ctl.rc_gp_output_ts = my_rsm->usec_orig_send;
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)my_rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
return;
}
use_latest:
/*
* We don't know how long we may have been
* idle or if this is the first-send. Lets
* setup the flag so we will trim off
* the first ack'd data so we get a true
* measurement.
*/
rack->app_limited_needs_set = 1;
tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
/* Find this guy so we can pull the send time */
fe.r_start = startseq;
my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (my_rsm) {
rack->r_ctl.rc_gp_output_ts = my_rsm->usec_orig_send;
if (my_rsm->r_flags & RACK_ACKED) {
/*
* Unlikely since its probably what was
* just transmitted (but I am paranoid).
*/
tp->gput_ts = my_rsm->r_ack_arrival;
rack->app_limited_needs_set = 0;
}
if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
/* This also is unlikely */
tp->gput_seq = my_rsm->r_start;
}
} else {
/*
* TSNH unless we have some send-map limit,
* and even at that it should not be hitting
* that limit (we should have stopped sending).
*/
rack->r_ctl.rc_gp_output_ts = tcp_get_usecs(NULL);
}
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)my_rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9, __LINE__, NULL);
}
static inline uint32_t
rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cwnd_to_use,
uint32_t avail, int32_t sb_offset)
{
uint32_t len;
uint32_t sendwin;
if (tp->snd_wnd > cwnd_to_use)
sendwin = cwnd_to_use;
else
sendwin = tp->snd_wnd;
if (ctf_outstanding(tp) >= tp->snd_wnd) {
/* We never want to go over our peers rcv-window */
len = 0;
} else {
uint32_t flight;
flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
if (flight >= sendwin) {
/*
* We have in flight what we are allowed by cwnd (if
* it was rwnd blocking it would have hit above out
* >= tp->snd_wnd).
*/
return (0);
}
len = sendwin - flight;
if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
/* We would send too much (beyond the rwnd) */
len = tp->snd_wnd - ctf_outstanding(tp);
}
if ((len + sb_offset) > avail) {
/*
* We don't have that much in the SB, how much is
* there?
*/
len = avail - sb_offset;
}
}
return (len);
}
static int
rack_output(struct tcpcb *tp)
{
struct socket *so;
uint32_t recwin;
uint32_t sb_offset;
int32_t len, flags, error = 0;
struct mbuf *m;
struct mbuf *mb;
uint32_t if_hw_tsomaxsegcount = 0;
uint32_t if_hw_tsomaxsegsize;
int32_t segsiz, minseg;
long tot_len_this_send = 0;
struct ip *ip = NULL;
#ifdef TCPDEBUG
struct ipovly *ipov = NULL;
#endif
struct udphdr *udp = NULL;
struct tcp_rack *rack;
struct tcphdr *th;
uint8_t pass = 0;
uint8_t mark = 0;
uint8_t wanted_cookie = 0;
u_char opt[TCP_MAXOLEN];
unsigned ipoptlen, optlen, hdrlen, ulen=0;
uint32_t rack_seq;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
unsigned ipsec_optlen = 0;
#endif
int32_t idle, sendalot;
int32_t sub_from_prr = 0;
volatile int32_t sack_rxmit;
struct rack_sendmap *rsm = NULL;
int32_t tso, mtu;
struct tcpopt to;
int32_t slot = 0;
int32_t sup_rack = 0;
uint32_t cts, us_cts, delayed, early;
uint8_t hpts_calling, new_data_tlp = 0, doing_tlp = 0;
uint32_t cwnd_to_use;
int32_t do_a_prefetch;
int32_t prefetch_rsm = 0;
int force_tso = 0;
int32_t orig_len;
struct timeval tv;
int32_t prefetch_so_done = 0;
struct tcp_log_buffer *lgb = NULL;
struct inpcb *inp;
struct sockbuf *sb;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
int32_t isipv6;
#endif
uint8_t filled_all = 0;
bool hw_tls = false;
/* setup and take the cache hits here */
rack = (struct tcp_rack *)tp->t_fb_ptr;
inp = rack->rc_inp;
so = inp->inp_socket;
sb = &so->so_snd;
kern_prefetch(sb, &do_a_prefetch);
do_a_prefetch = 1;
hpts_calling = inp->inp_hpts_calls;
#ifdef KERN_TLS
hw_tls = (so->so_snd.sb_flags & SB_TLS_IFNET) != 0;
#endif
NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(inp);
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
return (tcp_offload_output(tp));
#endif
/*
* For TFO connections in SYN_RECEIVED, only allow the initial
* SYN|ACK and those sent by the retransmit timer.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */
(rack->r_ctl.rc_resend == NULL)) /* not a retransmit */
return (0);
#ifdef INET6
if (rack->r_state) {
/* Use the cache line loaded if possible */
isipv6 = rack->r_is_v6;
} else {
isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
}
#endif
early = 0;
us_cts = tcp_get_usecs(&tv);
cts = tcp_tv_to_mssectick(&tv);
if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
inp->inp_in_hpts) {
/*
* We are on the hpts for some timer but not hptsi output.
* Remove from the hpts unconditionally.
*/
rack_timer_cancel(tp, rack, cts, __LINE__);
}
/* Are we pacing and late? */
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) {
/* We are delayed */
delayed = us_cts - rack->r_ctl.rc_last_output_to;
} else {
delayed = 0;
}
/* Do the timers, which may override the pacer */
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
if (rack_process_timers(tp, rack, cts, hpts_calling)) {
counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
return (0);
}
}
if ((rack->r_timer_override) ||
(delayed) ||
(tp->t_state < TCPS_ESTABLISHED)) {
if (tp->t_inpcb->inp_in_hpts)
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
} else if (tp->t_inpcb->inp_in_hpts) {
/*
* On the hpts you can't pass even if ACKNOW is on, we will
* when the hpts fires.
*/
counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
return (0);
}
inp->inp_hpts_calls = 0;
/* Finish out both pacing early and late accounting */
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
early = rack->r_ctl.rc_last_output_to - us_cts;
} else
early = 0;
if (delayed) {
rack->r_ctl.rc_agg_delayed += delayed;
rack->r_late = 1;
} else if (early) {
rack->r_ctl.rc_agg_early += early;
rack->r_early = 1;
}
/* Now that early/late accounting is done turn off the flag */
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack->r_wanted_output = 0;
rack->r_timer_override = 0;
/*
* For TFO connections in SYN_SENT or SYN_RECEIVED,
* only allow the initial SYN or SYN|ACK and those sent
* by the retransmit timer.
*/
if (IS_FASTOPEN(tp->t_flags) &&
((tp->t_state == TCPS_SYN_RECEIVED) ||
(tp->t_state == TCPS_SYN_SENT)) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
(tp->t_rxtshift == 0)) { /* not a retransmit */
cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
goto just_return_nolock;
}
/*
* Determine length of data that should be transmitted, and flags
* that will be used. If there is some data or critical controls
* (SYN, RST) to send, then transmit; otherwise, investigate
* further.
*/
idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
if (tp->t_idle_reduce) {
if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
rack_cc_after_idle(rack, tp);
}
tp->t_flags &= ~TF_LASTIDLE;
if (idle) {
if (tp->t_flags & TF_MORETOCOME) {
tp->t_flags |= TF_LASTIDLE;
idle = 0;
}
}
if ((tp->snd_una == tp->snd_max) &&
rack->r_ctl.rc_went_idle_time &&
TSTMP_GT(us_cts, rack->r_ctl.rc_went_idle_time)) {
idle = us_cts - rack->r_ctl.rc_went_idle_time;
if (idle > rack_min_probertt_hold) {
/* Count as a probe rtt */
if (rack->in_probe_rtt == 0) {
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
} else {
rack_exit_probertt(rack, us_cts);
}
}
idle = 0;
}
again:
/*
* If we've recently taken a timeout, snd_max will be greater than
* snd_nxt. There may be SACK information that allows us to avoid
* resending already delivered data. Adjust snd_nxt accordingly.
*/
sendalot = 0;
us_cts = tcp_get_usecs(&tv);
cts = tcp_tv_to_mssectick(&tv);
tso = 0;
mtu = 0;
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
if (so->so_snd.sb_flags & SB_TLS_IFNET) {
minseg = rack->r_ctl.rc_pace_min_segs;
} else {
minseg = segsiz;
}
sb_offset = tp->snd_max - tp->snd_una;
cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
#ifdef NETFLIX_SHARED_CWND
if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
rack->rack_enable_scwnd) {
/* We are doing cwnd sharing */
if (rack->rc_gp_filled &&
(rack->rack_attempted_scwnd == 0) &&
(rack->r_ctl.rc_scw == NULL) &&
tp->t_lib) {
/* The pcbid is in, lets make an attempt */
counter_u64_add(rack_try_scwnd, 1);
rack->rack_attempted_scwnd = 1;
rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
&rack->r_ctl.rc_scw_index,
segsiz);
}
if (rack->r_ctl.rc_scw &&
(rack->rack_scwnd_is_idle == 1) &&
(rack->rc_in_persist == 0) &&
sbavail(sb)) {
/* we are no longer out of data */
tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 0;
}
if (rack->r_ctl.rc_scw) {
/* First lets update and get the cwnd */
rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
rack->r_ctl.rc_scw_index,
tp->snd_cwnd, tp->snd_wnd, segsiz);
}
}
#endif
flags = tcp_outflags[tp->t_state];
while (rack->rc_free_cnt < rack_free_cache) {
rsm = rack_alloc(rack);
if (rsm == NULL) {
if (inp->inp_hpts_calls)
/* Retry in a ms */
slot = (1 * HPTS_USEC_IN_MSEC);
goto just_return_nolock;
}
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
rack->rc_free_cnt++;
rsm = NULL;
}
if (inp->inp_hpts_calls)
inp->inp_hpts_calls = 0;
sack_rxmit = 0;
len = 0;
rsm = NULL;
if (flags & TH_RST) {
SOCKBUF_LOCK(sb);
goto send;
}
if (rack->r_ctl.rc_resend) {
/* Retransmit timer */
rsm = rack->r_ctl.rc_resend;
rack->r_ctl.rc_resend = NULL;
rsm->r_flags &= ~RACK_TLP;
len = rsm->r_end - rsm->r_start;
sack_rxmit = 1;
sendalot = 0;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
if (len >= segsiz)
len = segsiz;
} else if ((rack->rc_in_persist == 0) &&
((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) {
/* We have a retransmit that takes precedence */
rsm->r_flags &= ~RACK_TLP;
if ((!IN_RECOVERY(tp->t_flags)) &&
((tp->t_flags & (TF_WASFRECOVERY | TF_WASCRECOVERY)) == 0)) {
/* Enter recovery if not induced by a time-out */
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure we send
* one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = segsiz;
rack_log_to_prr(rack, 13, 0);
}
}
#ifdef INVARIANTS
if (SEQ_LT(rsm->r_start, tp->snd_una)) {
panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
tp, rack, rsm, rsm->r_start, tp->snd_una);
}
#endif
len = rsm->r_end - rsm->r_start;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
/* Can we send it within the PRR boundary? */
if (rack->rack_no_prr == 0) {
if ((rack->use_rack_rr == 0) && (len > rack->r_ctl.rc_prr_sndcnt)) {
/* It does not fit */
if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) > len) &&
(rack->r_ctl.rc_prr_sndcnt < segsiz)) {
/*
* prr is less than a segment, we
* have more acks due in besides
* what we need to resend. Lets not send
* to avoid sending small pieces of
* what we need to retransmit.
*/
len = 0;
goto just_return_nolock;
}
len = rack->r_ctl.rc_prr_sndcnt;
}
}
sendalot = 0;
if (len >= segsiz)
len = segsiz;
if (len > 0) {
sub_from_prr = 1;
sack_rxmit = 1;
KMOD_TCPSTAT_INC(tcps_sack_rexmits);
KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
min(len, segsiz));
counter_u64_add(rack_rtm_prr_retran, 1);
}
} else if (rack->r_ctl.rc_tlpsend) {
/* Tail loss probe */
long cwin;
long tlen;
doing_tlp = 1;
/*
* Check if we can do a TLP with a RACK'd packet
* this can happen if we are not doing the rack
* cheat and we skipped to a TLP and it
* went off.
*/
rsm = rack->r_ctl.rc_tlpsend;
rsm->r_flags |= RACK_TLP;
rack->r_ctl.rc_tlpsend = NULL;
sack_rxmit = 1;
tlen = rsm->r_end - rsm->r_start;
if (tlen > segsiz)
tlen = segsiz;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
cwin = min(tp->snd_wnd, tlen);
len = cwin;
}
/*
* Enforce a connection sendmap count limit if set
* as long as we are not retransmiting.
*/
if ((rsm == NULL) &&
(rack->do_detection == 0) &&
(V_tcp_map_entries_limit > 0) &&
(rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
counter_u64_add(rack_to_alloc_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
goto just_return_nolock;
}
if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
/* we are retransmitting the fin */
len--;
if (len) {
/*
* When retransmitting data do *not* include the
* FIN. This could happen from a TLP probe.
*/
flags &= ~TH_FIN;
}
}
#ifdef INVARIANTS
/* For debugging */
rack->r_ctl.rc_rsm_at_retran = rsm;
#endif
/*
* Get standard flags, and add SYN or FIN if requested by 'hidden'
* state flags.
*/
if (tp->t_flags & TF_NEEDFIN)
flags |= TH_FIN;
if (tp->t_flags & TF_NEEDSYN)
flags |= TH_SYN;
if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
void *end_rsm;
end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
if (end_rsm)
kern_prefetch(end_rsm, &prefetch_rsm);
prefetch_rsm = 1;
}
SOCKBUF_LOCK(sb);
/*
* If snd_nxt == snd_max and we have transmitted a FIN, the
* sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
* negative length. This can also occur when TCP opens up its
* congestion window while receiving additional duplicate acks after
* fast-retransmit because TCP will reset snd_nxt to snd_max after
* the fast-retransmit.
*
* In the normal retransmit-FIN-only case, however, snd_nxt will be
* set to snd_una, the sb_offset will be 0, and the length may wind
* up 0.
*
* If sack_rxmit is true we are retransmitting from the scoreboard
* in which case len is already set.
*/
if ((sack_rxmit == 0) && TCPS_HAVEESTABLISHED(tp->t_state)) {
uint32_t avail;
avail = sbavail(sb);
if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
sb_offset = tp->snd_nxt - tp->snd_una;
else
sb_offset = 0;
if ((IN_RECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
if (rack->r_ctl.rc_tlp_new_data) {
/* TLP is forcing out new data */
if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
}
if (rack->r_ctl.rc_tlp_new_data > tp->snd_wnd)
len = tp->snd_wnd;
else
len = rack->r_ctl.rc_tlp_new_data;
rack->r_ctl.rc_tlp_new_data = 0;
new_data_tlp = doing_tlp = 1;
} else
len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
if (IN_RECOVERY(tp->t_flags) && (len > segsiz)) {
/*
* For prr=off, we need to send only 1 MSS
* at a time. We do this because another sack could
* be arriving that causes us to send retransmits and
* we don't want to be on a long pace due to a larger send
* that keeps us from sending out the retransmit.
*/
len = segsiz;
}
} else {
uint32_t outstanding;
/*
* We are inside of a SACK recovery episode and are
* sending new data, having retransmitted all the
* data possible so far in the scoreboard.
*/
outstanding = tp->snd_max - tp->snd_una;
if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
if (tp->snd_wnd > outstanding) {
len = tp->snd_wnd - outstanding;
/* Check to see if we have the data */
if ((sb_offset + len) > avail) {
/* It does not all fit */
if (avail > sb_offset)
len = avail - sb_offset;
else
len = 0;
}
} else
len = 0;
} else if (avail > sb_offset)
len = avail - sb_offset;
else
len = 0;
if (len > 0) {
if (len > rack->r_ctl.rc_prr_sndcnt)
len = rack->r_ctl.rc_prr_sndcnt;
if (len > 0) {
sub_from_prr = 1;
counter_u64_add(rack_rtm_prr_newdata, 1);
}
}
if (len > segsiz) {
/*
* We should never send more than a MSS when
* retransmitting or sending new data in prr
* mode unless the override flag is on. Most
* likely the PRR algorithm is not going to
* let us send a lot as well :-)
*/
if (rack->r_ctl.rc_prr_sendalot == 0)
len = segsiz;
} else if (len < segsiz) {
/*
* Do we send any? The idea here is if the
* send empty's the socket buffer we want to
* do it. However if not then lets just wait
* for our prr_sndcnt to get bigger.
*/
long leftinsb;
leftinsb = sbavail(sb) - sb_offset;
if (leftinsb > len) {
/* This send does not empty the sb */
len = 0;
}
}
}
} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
/*
* If you have not established
* and are not doing FAST OPEN
* no data please.
*/
if ((sack_rxmit == 0) &&
(!IS_FASTOPEN(tp->t_flags))){
len = 0;
sb_offset = 0;
}
}
if (prefetch_so_done == 0) {
kern_prefetch(so, &prefetch_so_done);
prefetch_so_done = 1;
}
/*
* Lop off SYN bit if it has already been sent. However, if this is
* SYN-SENT state and if segment contains data and if we don't know
* that foreign host supports TAO, suppress sending segment.
*/
if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
/*
* When sending additional segments following a TFO SYN|ACK,
* do not include the SYN bit.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED))
flags &= ~TH_SYN;
}
/*
* Be careful not to send data and/or FIN on SYN segments. This
* measure is needed to prevent interoperability problems with not
* fully conformant TCP implementations.
*/
if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
len = 0;
flags &= ~TH_FIN;
}
/*
* On TFO sockets, ensure no data is sent in the following cases:
*
* - When retransmitting SYN|ACK on a passively-created socket
*
* - When retransmitting SYN on an actively created socket
*
* - When sending a zero-length cookie (cookie request) on an
* actively created socket
*
* - When the socket is in the CLOSED state (RST is being sent)
*/
if (IS_FASTOPEN(tp->t_flags) &&
(((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
((tp->t_state == TCPS_SYN_SENT) &&
(tp->t_tfo_client_cookie_len == 0)) ||
(flags & TH_RST))) {
sack_rxmit = 0;
len = 0;
}
/* Without fast-open there should never be data sent on a SYN */
if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
tp->snd_nxt = tp->iss;
len = 0;
}
orig_len = len;
if (len <= 0) {
/*
* If FIN has been sent but not acked, but we haven't been
* called to retransmit, len will be < 0. Otherwise, window
* shrank after we sent into it. If window shrank to 0,
* cancel pending retransmit, pull snd_nxt back to (closed)
* window, and set the persist timer if it isn't already
* going. If the window didn't close completely, just wait
* for an ACK.
*
* We also do a general check here to ensure that we will
* set the persist timer when we have data to send, but a
* 0-byte window. This makes sure the persist timer is set
* even if the packet hits one of the "goto send" lines
* below.
*/
len = 0;
if ((tp->snd_wnd == 0) &&
(TCPS_HAVEESTABLISHED(tp->t_state)) &&
(tp->snd_una == tp->snd_max) &&
(sb_offset < (int)sbavail(sb))) {
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, cts);
}
} else if ((rsm == NULL) &&
((doing_tlp == 0) || (new_data_tlp == 1)) &&
(len < rack->r_ctl.rc_pace_max_segs)) {
/*
* We are not sending a maximum sized segment for
* some reason. Should we not send anything (think
* sws or persists)?
*/
if ((tp->snd_wnd < min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)), minseg)) &&
(TCPS_HAVEESTABLISHED(tp->t_state)) &&
(len < minseg) &&
(len < (int)(sbavail(sb) - sb_offset))) {
/*
* Here the rwnd is less than
* the minimum pacing size, this is not a retransmit,
* we are established and
* the send is not the last in the socket buffer
* we send nothing, and we may enter persists
* if nothing is outstanding.
*/
len = 0;
if (tp->snd_max == tp->snd_una) {
/*
* Nothing out we can
* go into persists.
*/
rack_enter_persist(tp, rack, cts);
tp->snd_nxt = tp->snd_una;
}
} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
(ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(len < minseg)) {
/*
* Here we are not retransmitting, and
* the cwnd is not so small that we could
* not send at least a min size (rxt timer
* not having gone off), We have 2 segments or
* more already in flight, its not the tail end
* of the socket buffer and the cwnd is blocking
* us from sending out a minimum pacing segment size.
* Lets not send anything.
*/
len = 0;
} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
(ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(TCPS_HAVEESTABLISHED(tp->t_state))) {
/*
* Here we have a send window but we have
* filled it up and we can't send another pacing segment.
* We also have in flight more than 2 segments
* and we are not completing the sb i.e. we allow
* the last bytes of the sb to go out even if
* its not a full pacing segment.
*/
len = 0;
}
}
/* len will be >= 0 after this point. */
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
tcp_sndbuf_autoscale(tp, so, min(tp->snd_wnd, cwnd_to_use));
/*
* Decide if we can use TCP Segmentation Offloading (if supported by
* hardware).
*
* TSO may only be used if we are in a pure bulk sending state. The
* presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
* options prevent using TSO. With TSO the TCP header is the same
* (except for the sequence number) for all generated packets. This
* makes it impossible to transmit any options which vary per
* generated segment or packet.
*
* IPv4 handling has a clear separation of ip options and ip header
* flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
* the right thing below to provide length of just ip options and thus
* checking for ipoptlen is enough to decide if ip options are present.
*/
#ifdef INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
if (tp->t_inpcb->inp_options)
ipoptlen = tp->t_inpcb->inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
else
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
/*
* Pre-calculate here as we save another lookup into the darknesses
* of IPsec that way and can actually decide if TSO is ok.
*/
#ifdef INET6
if (isipv6 && IPSEC_ENABLED(ipv6))
ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
#ifdef INET
else
#endif
#endif /* INET6 */
#ifdef INET
if (IPSEC_ENABLED(ipv4))
ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
#endif /* INET */
#endif
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
(tp->t_port == 0) &&
((tp->t_flags & TF_SIGNATURE) == 0) &&
tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
ipoptlen == 0)
tso = 1;
{
uint32_t outstanding;
outstanding = tp->snd_max - tp->snd_una;
if (tp->t_flags & TF_SENTFIN) {
/*
* If we sent a fin, snd_max is 1 higher than
* snd_una
*/
outstanding--;
}
if (sack_rxmit) {
if ((rsm->r_flags & RACK_HAS_FIN) == 0)
flags &= ~TH_FIN;
} else {
if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
sbused(sb)))
flags &= ~TH_FIN;
}
}
recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
(long)TCP_MAXWIN << tp->rcv_scale);
/*
* Sender silly window avoidance. We transmit under the following
* conditions when len is non-zero:
*
* - We have a full segment (or more with TSO) - This is the last
* buffer in a write()/send() and we are either idle or running
* NODELAY - we've timed out (e.g. persist timer) - we have more
* then 1/2 the maximum send window's worth of data (receiver may be
* limited the window size) - we need to retransmit
*/
if (len) {
if (len >= segsiz) {
goto send;
}
/*
* NOTE! on localhost connections an 'ack' from the remote
* end may occur synchronously with the output and cause us
* to flush a buffer queued with moretocome. XXX
*
*/
if (!(tp->t_flags & TF_MORETOCOME) && /* normal case */
(idle || (tp->t_flags & TF_NODELAY)) &&
((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
(tp->t_flags & TF_NOPUSH) == 0) {
pass = 2;
goto send;
}
if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
pass = 22;
goto send;
}
if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
pass = 4;
goto send;
}
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { /* retransmit case */
pass = 5;
goto send;
}
if (sack_rxmit) {
pass = 6;
goto send;
}
if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
(ctf_outstanding(tp) < (segsiz * 2))) {
/*
* We have less than two MSS outstanding (delayed ack)
* and our rwnd will not let us send a full sized
* MSS. Lets go ahead and let this small segment
* out because we want to try to have at least two
* packets inflight to not be caught by delayed ack.
*/
pass = 12;
goto send;
}
}
/*
* Sending of standalone window updates.
*
* Window updates are important when we close our window due to a
* full socket buffer and are opening it again after the application
* reads data from it. Once the window has opened again and the
* remote end starts to send again the ACK clock takes over and
* provides the most current window information.
*
* We must avoid the silly window syndrome whereas every read from
* the receive buffer, no matter how small, causes a window update
* to be sent. We also should avoid sending a flurry of window
* updates when the socket buffer had queued a lot of data and the
* application is doing small reads.
*
* Prevent a flurry of pointless window updates by only sending an
* update when we can increase the advertized window by more than
* 1/4th of the socket buffer capacity. When the buffer is getting
* full or is very small be more aggressive and send an update
* whenever we can increase by two mss sized segments. In all other
* situations the ACK's to new incoming data will carry further
* window increases.
*
* Don't send an independent window update if a delayed ACK is
* pending (it will get piggy-backed on it) or the remote side
* already has done a half-close and won't send more data. Skip
* this if the connection is in T/TCP half-open state.
*/
if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
!(tp->t_flags & TF_DELACK) &&
!TCPS_HAVERCVDFIN(tp->t_state)) {
/*
* "adv" is the amount we could increase the window, taking
* into account that we are limited by TCP_MAXWIN <<
* tp->rcv_scale.
*/
int32_t adv;
int oldwin;
adv = recwin;
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
oldwin = (tp->rcv_adv - tp->rcv_nxt);
if (adv > oldwin)
adv -= oldwin;
else {
/* We can't increase the window */
adv = 0;
}
} else
oldwin = 0;
/*
* If the new window size ends up being the same as or less
* than the old size when it is scaled, then don't force
* a window update.
*/
if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
goto dontupdate;
if (adv >= (int32_t)(2 * segsiz) &&
(adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
so->so_rcv.sb_hiwat <= 8 * segsiz)) {
pass = 7;
goto send;
}
if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
pass = 23;
goto send;
}
}
dontupdate:
/*
* Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW
* is also a catch-all for the retransmit timer timeout case.
*/
if (tp->t_flags & TF_ACKNOW) {
pass = 8;
goto send;
}
if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
pass = 9;
goto send;
}
/*
* If our state indicates that FIN should be sent and we have not
* yet done so, then we need to send.
*/
if ((flags & TH_FIN) &&
(tp->snd_nxt == tp->snd_una)) {
pass = 11;
goto send;
}
/*
* No reason to send a segment, just return.
*/
just_return:
SOCKBUF_UNLOCK(sb);
just_return_nolock:
{
int app_limited = CTF_JR_SENT_DATA;
if (tot_len_this_send > 0) {
/* Make sure snd_nxt is up to max */
if (SEQ_GT(tp->snd_max, tp->snd_nxt))
tp->snd_nxt = tp->snd_max;
slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
} else {
int end_window = 0;
uint32_t seq = tp->gput_ack;
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm) {
/*
* Mark the last sent that we just-returned (hinting
* that delayed ack may play a role in any rtt measurement).
*/
rsm->r_just_ret = 1;
}
counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
if ((ctf_outstanding(tp) +
min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
minseg)) >= tp->snd_wnd) {
/* We are limited by the rwnd */
app_limited = CTF_JR_RWND_LIMITED;
} else if (ctf_outstanding(tp) >= sbavail(sb)) {
/* We are limited by whats available -- app limited */
app_limited = CTF_JR_APP_LIMITED;
} else if ((idle == 0) &&
((tp->t_flags & TF_NODELAY) == 0) &&
((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
(len < segsiz)) {
/*
* No delay is not on and the
* user is sending less than 1MSS. This
* brings out SWS avoidance so we
* don't send. Another app-limited case.
*/
app_limited = CTF_JR_APP_LIMITED;
} else if (tp->t_flags & TF_NOPUSH) {
/*
* The user has requested no push of
* the last segment and we are
* at the last segment. Another app
* limited case.
*/
app_limited = CTF_JR_APP_LIMITED;
} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
/* Its the cwnd */
app_limited = CTF_JR_CWND_LIMITED;
} else if (rack->rc_in_persist == 1) {
/* We are in persists */
app_limited = CTF_JR_PERSISTS;
} else if (IN_RECOVERY(tp->t_flags) &&
(rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt < segsiz)) {
app_limited = CTF_JR_PRR;
} else {
/* Now why here are we not sending? */
#ifdef NOW
#ifdef INVARIANTS
panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
#endif
#endif
app_limited = CTF_JR_ASSESSING;
}
/*
* App limited in some fashion, for our pacing GP
* measurements we don't want any gap (even cwnd).
* Close down the measurement window.
*/
if (rack_cwnd_block_ends_measure &&
((app_limited == CTF_JR_CWND_LIMITED) ||
(app_limited == CTF_JR_PRR))) {
/*
* The reason we are not sending is
* the cwnd (or prr). We have been configured
* to end the measurement window in
* this case.
*/
end_window = 1;
} else if (app_limited == CTF_JR_PERSISTS) {
/*
* We never end the measurement window
* in persists, though in theory we
* should be only entering after everything
* is acknowledged (so we will probably
* never come here).
*/
end_window = 0;
} else if (rack_rwnd_block_ends_measure &&
(app_limited == CTF_JR_RWND_LIMITED)) {
/*
* We are rwnd limited and have been
* configured to end the measurement
* window in this case.
*/
end_window = 1;
} else if (app_limited == CTF_JR_APP_LIMITED) {
/*
* A true application limited period, we have
* ran out of data.
*/
end_window = 1;
} else if (app_limited == CTF_JR_ASSESSING) {
/*
* In the assessing case we hit the end of
* the if/else and had no known reason
* This will panic us under invariants..
*
* If we get this out in logs we need to
* investagate which reason we missed.
*/
end_window = 1;
}
if (end_window) {
uint8_t log = 0;
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(tp->gput_ack, tp->snd_max)) {
/* Mark the last packet has app limited */
tp->gput_ack = tp->snd_max;
log = 1;
}
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
else {
/*
* Go out to the end app limited and mark
* this new one as next and move the end_appl up
* to this guy.
*/
if (rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
rack->r_ctl.rc_end_appl = rsm;
}
rsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
if (log)
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_app_limited_cnt, seq,
tp->gput_ack, 0, 0, 4, __LINE__, NULL);
}
}
if (slot) {
/* set the rack tcb into the slot N */
counter_u64_add(rack_paced_segments, 1);
} else if (tot_len_this_send) {
counter_u64_add(rack_unpaced_segments, 1);
}
/* Check if we need to go into persists or not */
if ((rack->rc_in_persist == 0) &&
(tp->snd_max == tp->snd_una) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
sbavail(sb) &&
(sbavail(sb) > tp->snd_wnd) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
/* Yes lets make sure to move to persist before timer-start */
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
}
#ifdef NETFLIX_SHARED_CWND
if ((sbavail(sb) == 0) &&
rack->r_ctl.rc_scw) {
tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 1;
}
#endif
return (0);
send:
if ((flags & TH_FIN) &&
sbavail(sb)) {
/*
* We do not transmit a FIN
* with data outstanding. We
* need to make it so all data
* is acked first.
*/
flags &= ~TH_FIN;
}
/* Enforce stack imposed max seg size if we have one */
if (rack->r_ctl.rc_pace_max_segs &&
(len > rack->r_ctl.rc_pace_max_segs)) {
mark = 1;
len = rack->r_ctl.rc_pace_max_segs;
}
SOCKBUF_LOCK_ASSERT(sb);
if (len > 0) {
if (len >= segsiz)
tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
else
tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
}
/*
* Before ESTABLISHED, force sending of initial options unless TCP
* set not to do any options. NOTE: we assume that the IP/TCP header
* plus TCP options always fit in a single mbuf, leaving room for a
* maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
* + optlen <= MCLBYTES
*/
optlen = 0;
#ifdef INET6
if (isipv6)
hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
else
#endif
hdrlen = sizeof(struct tcpiphdr);
/*
* Compute options for segment. We only have to care about SYN and
* established connection segments. Options for SYN-ACK segments
* are handled in TCP syncache.
*/
to.to_flags = 0;
if ((tp->t_flags & TF_NOOPT) == 0) {
/* Maximum segment size. */
if (flags & TH_SYN) {
tp->snd_nxt = tp->iss;
to.to_mss = tcp_mssopt(&inp->inp_inc);
#ifdef NETFLIX_TCPOUDP
if (tp->t_port)
to.to_mss -= V_tcp_udp_tunneling_overhead;
#endif
to.to_flags |= TOF_MSS;
/*
* On SYN or SYN|ACK transmits on TFO connections,
* only include the TFO option if it is not a
* retransmit, as the presence of the TFO option may
* have caused the original SYN or SYN|ACK to have
* been dropped by a middlebox.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_rxtshift == 0)) {
if (tp->t_state == TCPS_SYN_RECEIVED) {
to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
to.to_tfo_cookie =
(u_int8_t *)&tp->t_tfo_cookie.server;
to.to_flags |= TOF_FASTOPEN;
wanted_cookie = 1;
} else if (tp->t_state == TCPS_SYN_SENT) {
to.to_tfo_len =
tp->t_tfo_client_cookie_len;
to.to_tfo_cookie =
tp->t_tfo_cookie.client;
to.to_flags |= TOF_FASTOPEN;
wanted_cookie = 1;
/*
* If we wind up having more data to
* send with the SYN than can fit in
* one segment, don't send any more
* until the SYN|ACK comes back from
* the other end.
*/
sendalot = 0;
}
}
}
/* Window scaling. */
if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
to.to_wscale = tp->request_r_scale;
to.to_flags |= TOF_SCALE;
}
/* Timestamps. */
if ((tp->t_flags & TF_RCVD_TSTMP) ||
((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
to.to_tsval = cts + tp->ts_offset;
to.to_tsecr = tp->ts_recent;
to.to_flags |= TOF_TS;
}
/* Set receive buffer autosizing timestamp. */
if (tp->rfbuf_ts == 0 &&
(so->so_rcv.sb_flags & SB_AUTOSIZE))
tp->rfbuf_ts = tcp_ts_getticks();
/* Selective ACK's. */
if (flags & TH_SYN)
to.to_flags |= TOF_SACKPERM;
else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
tp->rcv_numsacks > 0) {
to.to_flags |= TOF_SACK;
to.to_nsacks = tp->rcv_numsacks;
to.to_sacks = (u_char *)tp->sackblks;
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/* TCP-MD5 (RFC2385). */
if (tp->t_flags & TF_SIGNATURE)
to.to_flags |= TOF_SIGNATURE;
#endif /* TCP_SIGNATURE */
/* Processing the options. */
hdrlen += optlen = tcp_addoptions(&to, opt);
/*
* If we wanted a TFO option to be added, but it was unable
* to fit, ensure no data is sent.
*/
if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
!(to.to_flags & TOF_FASTOPEN))
len = 0;
}
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
if (V_tcp_udp_tunneling_port == 0) {
/* The port was removed?? */
SOCKBUF_UNLOCK(&so->so_snd);
return (EHOSTUNREACH);
}
hdrlen += sizeof(struct udphdr);
}
#endif
#ifdef INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
if (tp->t_inpcb->inp_options)
ipoptlen = tp->t_inpcb->inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
else
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
#ifdef KERN_TLS
/* force TSO for so TLS offload can get mss */
if (sb->sb_flags & SB_TLS_IFNET) {
force_tso = 1;
}
#endif
/*
* Adjust data length if insertion of options will bump the packet
* length beyond the t_maxseg length. Clear the FIN bit because we
* cut off the tail of the segment.
*/
if (len + optlen + ipoptlen > tp->t_maxseg) {
if (tso) {
uint32_t if_hw_tsomax;
uint32_t moff;
int32_t max_len;
/* extract TSO information */
if_hw_tsomax = tp->t_tsomax;
if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
KASSERT(ipoptlen == 0,
("%s: TSO can't do IP options", __func__));
/*
* Check if we should limit by maximum payload
* length:
*/
if (if_hw_tsomax != 0) {
/* compute maximum TSO length */
max_len = (if_hw_tsomax - hdrlen -
max_linkhdr);
if (max_len <= 0) {
len = 0;
} else if (len > max_len) {
sendalot = 1;
len = max_len;
mark = 2;
}
}
/*
* Prevent the last segment from being fractional
* unless the send sockbuf can be emptied:
*/
max_len = (tp->t_maxseg - optlen);
if (((sb_offset + len) < sbavail(sb)) &&
(hw_tls == 0)) {
moff = len % (u_int)max_len;
if (moff != 0) {
mark = 3;
len -= moff;
}
}
/*
* In case there are too many small fragments don't
* use TSO:
*/
if (len <= segsiz) {
mark = 4;
tso = 0;
}
/*
* Send the FIN in a separate segment after the bulk
* sending is done. We don't trust the TSO
* implementations to clear the FIN flag on all but
* the last segment.
*/
if (tp->t_flags & TF_NEEDFIN) {
sendalot = 4;
}
} else {
mark = 5;
if (optlen + ipoptlen >= tp->t_maxseg) {
/*
* Since we don't have enough space to put
* the IP header chain and the TCP header in
* one packet as required by RFC 7112, don't
* send it. Also ensure that at least one
* byte of the payload can be put into the
* TCP segment.
*/
SOCKBUF_UNLOCK(&so->so_snd);
error = EMSGSIZE;
sack_rxmit = 0;
goto out;
}
len = tp->t_maxseg - optlen - ipoptlen;
sendalot = 5;
}
} else {
tso = 0;
mark = 6;
}
KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
("%s: len > IP_MAXPACKET", __func__));
#ifdef DIAGNOSTIC
#ifdef INET6
if (max_linkhdr + hdrlen > MCLBYTES)
#else
if (max_linkhdr + hdrlen > MHLEN)
#endif
panic("tcphdr too big");
#endif
/*
* This KASSERT is here to catch edge cases at a well defined place.
* Before, those had triggered (random) panic conditions further
* down.
*/
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
if ((len == 0) &&
(flags & TH_FIN) &&
(sbused(sb))) {
/*
* We have outstanding data, don't send a fin by itself!.
*/
goto just_return;
}
/*
* Grab a header mbuf, attaching a copy of data to be transmitted,
* and initialize the header from the template for sends on this
* connection.
*/
if (len) {
uint32_t max_val;
uint32_t moff;
if (rack->r_ctl.rc_pace_max_segs)
max_val = rack->r_ctl.rc_pace_max_segs;
else if (rack->rc_user_set_max_segs)
max_val = rack->rc_user_set_max_segs * segsiz;
else
max_val = len;
/*
* We allow a limit on sending with hptsi.
*/
if (len > max_val) {
mark = 7;
len = max_val;
}
#ifdef INET6
if (MHLEN < hdrlen + max_linkhdr)
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
else
#endif
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
SOCKBUF_UNLOCK(sb);
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
m->m_data += max_linkhdr;
m->m_len = hdrlen;
/*
* Start the m_copy functions from the closest mbuf to the
* sb_offset in the socket buffer chain.
*/
mb = sbsndptr_noadv(sb, sb_offset, &moff);
if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
m_copydata(mb, moff, (int)len,
mtod(m, caddr_t)+hdrlen);
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
sbsndptr_adv(sb, mb, len);
m->m_len += len;
} else {
struct sockbuf *msb;
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
msb = NULL;
else
msb = sb;
m->m_next = tcp_m_copym(
mb, moff, &len,
if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
((rsm == NULL) ? hw_tls : 0)
#ifdef NETFLIX_COPY_ARGS
, &filled_all
#endif
);
if (len <= (tp->t_maxseg - optlen)) {
/*
* Must have ran out of mbufs for the copy
* shorten it to no longer need tso. Lets
* not put on sendalot since we are low on
* mbufs.
*/
tso = 0;
}
if (m->m_next == NULL) {
SOCKBUF_UNLOCK(sb);
(void)m_free(m);
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
}
if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
if (rsm && (rsm->r_flags & RACK_TLP)) {
/*
* TLP should not count in retran count, but
* in its own bin
*/
counter_u64_add(rack_tlp_retran, 1);
counter_u64_add(rack_tlp_retran_bytes, len);
} else {
tp->t_sndrexmitpack++;
KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
}
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
len);
#endif
} else {
KMOD_TCPSTAT_INC(tcps_sndpack);
KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
#ifdef STATS
stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
len);
#endif
}
/*
* If we're sending everything we've got, set PUSH. (This
* will keep happy those implementations which only give
* data to the user when a buffer fills or a PUSH comes in.)
*/
if (sb_offset + len == sbused(sb) &&
sbused(sb) &&
!(flags & TH_SYN))
flags |= TH_PUSH;
SOCKBUF_UNLOCK(sb);
} else {
SOCKBUF_UNLOCK(sb);
if (tp->t_flags & TF_ACKNOW)
KMOD_TCPSTAT_INC(tcps_sndacks);
else if (flags & (TH_SYN | TH_FIN | TH_RST))
KMOD_TCPSTAT_INC(tcps_sndctrl);
else
KMOD_TCPSTAT_INC(tcps_sndwinup);
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
#ifdef INET6
if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
MHLEN >= hdrlen) {
M_ALIGN(m, hdrlen);
} else
#endif
m->m_data += max_linkhdr;
m->m_len = hdrlen;
}
SOCKBUF_UNLOCK_ASSERT(sb);
m->m_pkthdr.rcvif = (struct ifnet *)0;
#ifdef MAC
mac_inpcb_create_mbuf(inp, m);
#endif
#ifdef INET6
if (isipv6) {
ip6 = mtod(m, struct ip6_hdr *);
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = tp->t_port;
ulen = hdrlen + len - sizeof(struct ip6_hdr);
udp->uh_ulen = htons(ulen);
th = (struct tcphdr *)(udp + 1);
} else
#endif
th = (struct tcphdr *)(ip6 + 1);
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip6, th);
} else
#endif /* INET6 */
{
ip = mtod(m, struct ip *);
#ifdef TCPDEBUG
ipov = (struct ipovly *)ip;
#endif
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = tp->t_port;
ulen = hdrlen + len - sizeof(struct ip);
udp->uh_ulen = htons(ulen);
th = (struct tcphdr *)(udp + 1);
} else
#endif
th = (struct tcphdr *)(ip + 1);
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip, th);
}
/*
* Fill in fields, remembering maximum advertised window for use in
* delaying messages about window sizes. If resending a FIN, be sure
* not to use a new sequence number.
*/
if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
tp->snd_nxt == tp->snd_max)
tp->snd_nxt--;
/*
* If we are starting a connection, send ECN setup SYN packet. If we
* are on a retransmit, we may resend those bits a number of times
* as per RFC 3168.
*/
if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
if (tp->t_rxtshift >= 1) {
if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
flags |= TH_ECE | TH_CWR;
} else
flags |= TH_ECE | TH_CWR;
}
/* Handle parallel SYN for ECN */
if ((tp->t_state == TCPS_SYN_RECEIVED) &&
(tp->t_flags2 & TF2_ECN_SND_ECE)) {
flags |= TH_ECE;
tp->t_flags2 &= ~TF2_ECN_SND_ECE;
}
if (tp->t_state == TCPS_ESTABLISHED &&
(tp->t_flags2 & TF2_ECN_PERMIT)) {
/*
* If the peer has ECN, mark data packets with ECN capable
* transmission (ECT). Ignore pure ack packets,
* retransmissions.
*/
if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
(sack_rxmit == 0)) {
#ifdef INET6
if (isipv6)
ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
else
#endif
ip->ip_tos |= IPTOS_ECN_ECT0;
KMOD_TCPSTAT_INC(tcps_ecn_ect0);
/*
* Reply with proper ECN notifications.
* Only set CWR on new data segments.
*/
if (tp->t_flags2 & TF2_ECN_SND_CWR) {
flags |= TH_CWR;
tp->t_flags2 &= ~TF2_ECN_SND_CWR;
}
}
if (tp->t_flags2 & TF2_ECN_SND_ECE)
flags |= TH_ECE;
}
/*
* If we are doing retransmissions, then snd_nxt will not reflect
* the first unsent octet. For ACK only packets, we do not want the
* sequence number of the retransmitted packet, we want the sequence
* number of the next unsent octet. So, if there is no data (and no
* SYN or FIN), use snd_max instead of snd_nxt when filling in
* ti_seq. But if we are in persist state, snd_max might reflect
* one byte beyond the right edge of the window, so use snd_nxt in
* that case, since we know we aren't doing a retransmission.
* (retransmit and persist are mutually exclusive...)
*/
if (sack_rxmit == 0) {
if (len || (flags & (TH_SYN | TH_FIN)) ||
rack->rc_in_persist) {
th->th_seq = htonl(tp->snd_nxt);
rack_seq = tp->snd_nxt;
} else if (flags & TH_RST) {
/*
* For a Reset send the last cum ack in sequence
* (this like any other choice may still generate a
* challenge ack, if a ack-update packet is in
* flight).
*/
th->th_seq = htonl(tp->snd_una);
rack_seq = tp->snd_una;
} else {
th->th_seq = htonl(tp->snd_max);
rack_seq = tp->snd_max;
}
} else {
th->th_seq = htonl(rsm->r_start);
rack_seq = rsm->r_start;
}
th->th_ack = htonl(tp->rcv_nxt);
if (optlen) {
bcopy(opt, th + 1, optlen);
th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
}
th->th_flags = flags;
/*
* Calculate receive window. Don't shrink window, but avoid silly
* window syndrome.
* If a RST segment is sent, advertise a window of zero.
*/
if (flags & TH_RST) {
recwin = 0;
} else {
if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
recwin < (long)segsiz)
recwin = 0;
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
}
/*
* According to RFC1323 the window field in a SYN (i.e., a <SYN> or
* <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is
* handled in syncache.
*/
if (flags & TH_SYN)
th->th_win = htons((u_short)
(min(sbspace(&so->so_rcv), TCP_MAXWIN)));
else {
/* Avoid shrinking window with window scaling. */
recwin = roundup2(recwin, 1 << tp->rcv_scale);
th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
}
/*
* Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
* window. This may cause the remote transmitter to stall. This
* flag tells soreceive() to disable delayed acknowledgements when
* draining the buffer. This can occur if the receiver is
* attempting to read more data than can be buffered prior to
* transmitting on the connection.
*/
if (th->th_win == 0) {
tp->t_sndzerowin++;
tp->t_flags |= TF_RXWIN0SENT;
} else
tp->t_flags &= ~TF_RXWIN0SENT;
tp->snd_up = tp->snd_una; /* drag it along, its deprecated */
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
if (to.to_flags & TOF_SIGNATURE) {
/*
* Calculate MD5 signature and put it into the place
* determined before.
* NOTE: since TCP options buffer doesn't point into
* mbuf's data, calculate offset and use it.
*/
if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
(u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
/*
* Do not send segment if the calculation of MD5
* digest has failed.
*/
goto out;
}
}
#endif
/*
* Put TCP length in extended header, and then checksum extended
* header and data.
*/
m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
#ifdef INET6
if (isipv6) {
/*
* ip6_plen is not need to be filled now, and will be filled
* in ip6_output.
*/
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in6_cksum_pseudo(ip6,
sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
0);
}
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
IPPROTO_TCP + len + optlen));
}
/* IP version must be set here for ipv4/ipv6 checking later */
KASSERT(ip->ip_v == IPVERSION,
("%s: IP version incorrect: %d", __func__, ip->ip_v));
}
#endif
/*
* Enable TSO and specify the size of the segments. The TCP pseudo
* header checksum is always provided. XXX: Fixme: This is currently
* not the case for IPv6.
*/
if (tso || force_tso) {
KASSERT(force_tso || len > tp->t_maxseg - optlen,
("%s: len <= tso_segsz", __func__));
m->m_pkthdr.csum_flags |= CSUM_TSO;
m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
}
KASSERT(len + hdrlen == m_length(m, NULL),
("%s: mbuf chain different than expected: %d + %u != %u",
__func__, len, hdrlen, m_length(m, NULL)));
#ifdef TCP_HHOOK
/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
hhook_run_tcp_est_out(tp, th, &to, len, tso);
#endif
#ifdef TCPDEBUG
/*
* Trace.
*/
if (so->so_options & SO_DEBUG) {
u_short save = 0;
#ifdef INET6
if (!isipv6)
#endif
{
save = ipov->ih_len;
ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen +
* (th->th_off << 2) */ );
}
tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0);
#ifdef INET6
if (!isipv6)
#endif
ipov->ih_len = save;
}
#endif /* TCPDEBUG */
/* We're getting ready to send; log now. */
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
if (rack->rack_no_prr)
log.u_bbr.flex1 = 0;
else
log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex4 = orig_len;
if (filled_all)
log.u_bbr.flex5 = 0x80000000;
else
log.u_bbr.flex5 = 0;
/* Save off the early/late values */
log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
log.u_bbr.bw_inuse = rack_get_bw(rack);
if (rsm || sack_rxmit) {
if (doing_tlp)
log.u_bbr.flex8 = 2;
else
log.u_bbr.flex8 = 1;
} else {
log.u_bbr.flex8 = 0;
}
log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
log.u_bbr.flex7 = mark;
log.u_bbr.pkts_out = tp->t_maxseg;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.lt_epoch = cwnd_to_use;
log.u_bbr.delivered = sendalot;
lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
len, &log, false, NULL, NULL, 0, &tv);
} else
lgb = NULL;
/*
* Fill in IP length and desired time to live and send to IP level.
* There should be a better way to handle ttl and tos; we could keep
* them in the template, but need a way to checksum without them.
*/
/*
* m->m_pkthdr.len should have been set before cksum calcuration,
* because in6_cksum() need it.
*/
#ifdef INET6
if (isipv6) {
/*
* we separately set hoplimit for every segment, since the
* user might want to change the value via setsockopt. Also,
* desired default hop limit might be changed via Neighbor
* Discovery.
*/
ip6->ip6_hlim = in6_selecthlim(inp, NULL);
/*
* Set the packet size here for the benefit of DTrace
* probes. ip6_output() will set it properly; it's supposed
* to include the option header lengths as well.
*/
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
else
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
TCP_PROBE5(send, NULL, tp, ip6, tp, th);
/* TODO: IPv6 IP6TOS_ECT bit on */
error = ip6_output(m, inp->in6p_outputopts,
&inp->inp_route6,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
NULL, NULL, inp);
if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
mtu = inp->inp_route6.ro_nh->nh_mtu;
}
#endif /* INET6 */
#if defined(INET) && defined(INET6)
else
#endif
#ifdef INET
{
ip->ip_len = htons(m->m_pkthdr.len);
#ifdef INET6
if (inp->inp_vflag & INP_IPV6PROTO)
ip->ip_ttl = in6_selecthlim(inp, NULL);
#endif /* INET6 */
/*
* If we do path MTU discovery, then we set DF on every
* packet. This might not be the best thing to do according
* to RFC3390 Section 2. However the tcp hostcache migitates
* the problem so it affects only the first tcp connection
* with a host.
*
* NB: Don't set DF on small MTU/MSS to have a safe
* fallback.
*/
if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
if (tp->t_port == 0 || len < V_tcp_minmss) {
ip->ip_off |= htons(IP_DF);
}
} else {
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
}
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
TCP_PROBE5(send, NULL, tp, ip, tp, th);
error = ip_output(m, inp->inp_options, &inp->inp_route,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
inp);
if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
mtu = inp->inp_route.ro_nh->nh_mtu;
}
#endif /* INET */
out:
if (lgb) {
lgb->tlb_errno = error;
lgb = NULL;
}
/*
* In transmit state, time the transmission and arrange for the
* retransmit. In persist state, just set snd_max.
*/
if (error == 0) {
rack->forced_ack = 0; /* If we send something zap the FA flag */
if (rsm && (doing_tlp == 0)) {
/* Set we retransmitted */
rack->rc_gp_saw_rec = 1;
} else {
if (cwnd_to_use > tp->snd_ssthresh) {
/* Set we sent in CA */
rack->rc_gp_saw_ca = 1;
} else {
/* Set we sent in SS */
rack->rc_gp_saw_ss = 1;
}
}
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->t_flags & TF_SACK_PERMIT) &&
tp->rcv_numsacks > 0)
tcp_clean_dsack_blocks(tp);
tot_len_this_send += len;
if (len == 0)
counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
else if (len == 1) {
counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
} else if (len > 1) {
int idx;
idx = (len / segsiz) + 3;
if (idx >= TCP_MSS_ACCT_ATIMER)
counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
else
counter_u64_add(rack_out_size[idx], 1);
}
if (hw_tls && len > 0) {
if (filled_all) {
counter_u64_add(rack_tls_filled, 1);
rack_log_type_hrdwtso(tp, rack, len, 0, orig_len, 1);
} else {
if (rsm) {
counter_u64_add(rack_tls_rxt, 1);
rack_log_type_hrdwtso(tp, rack, len, 2, orig_len, 1);
} else if (doing_tlp) {
counter_u64_add(rack_tls_tlp, 1);
rack_log_type_hrdwtso(tp, rack, len, 3, orig_len, 1);
} else if ( (ctf_outstanding(tp) + minseg) > sbavail(sb)) {
counter_u64_add(rack_tls_app, 1);
rack_log_type_hrdwtso(tp, rack, len, 4, orig_len, 1);
} else if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) + minseg) > cwnd_to_use) {
counter_u64_add(rack_tls_cwnd, 1);
rack_log_type_hrdwtso(tp, rack, len, 5, orig_len, 1);
} else if ((ctf_outstanding(tp) + minseg) > tp->snd_wnd) {
counter_u64_add(rack_tls_rwnd, 1);
rack_log_type_hrdwtso(tp, rack, len, 6, orig_len, 1);
} else {
rack_log_type_hrdwtso(tp, rack, len, 7, orig_len, 1);
counter_u64_add(rack_tls_other, 1);
}
}
}
}
if (rack->rack_no_prr == 0) {
if (sub_from_prr && (error == 0)) {
if (rack->r_ctl.rc_prr_sndcnt >= len)
rack->r_ctl.rc_prr_sndcnt -= len;
else
rack->r_ctl.rc_prr_sndcnt = 0;
}
}
sub_from_prr = 0;
rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts,
pass, rsm, us_cts);
if ((error == 0) &&
(len > 0) &&
(tp->snd_una == tp->snd_max))
rack->r_ctl.rc_tlp_rxt_last_time = cts;
/* Now are we in persists? */
if (rack->rc_in_persist == 0) {
tcp_seq startseq = tp->snd_nxt;
/* Track our lost count */
if (rsm && (doing_tlp == 0))
rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
/*
* Advance snd_nxt over sequence space of this segment.
*/
if (error)
/* We don't log or do anything with errors */
goto nomore;
if (doing_tlp == 0) {
if (rsm == NULL) {
/*
* Not a retransmission of some
* sort, new data is going out so
* clear our TLP count and flag.
*/
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
}
} else {
/*
* We have just sent a TLP, mark that it is true
* and make sure our in progress is set so we
* continue to check the count.
*/
rack->rc_tlp_in_progress = 1;
rack->r_ctl.rc_tlp_cnt_out++;
}
if (flags & (TH_SYN | TH_FIN)) {
if (flags & TH_SYN)
tp->snd_nxt++;
if (flags & TH_FIN) {
tp->snd_nxt++;
tp->t_flags |= TF_SENTFIN;
}
}
/* In the ENOBUFS case we do *not* update snd_max */
if (sack_rxmit)
goto nomore;
tp->snd_nxt += len;
if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
if (tp->snd_una == tp->snd_max) {
/*
* Update the time we just added data since
* none was outstanding.
*/
rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
tp->t_acktime = ticks;
}
tp->snd_max = tp->snd_nxt;
/*
* Time this transmission if not a retransmission and
* not currently timing anything.
* This is only relevant in case of switching back to
* the base stack.
*/
if (tp->t_rtttime == 0) {
tp->t_rtttime = ticks;
tp->t_rtseq = startseq;
KMOD_TCPSTAT_INC(tcps_segstimed);
}
if (len &&
((tp->t_flags & TF_GPUTINPROG) == 0))
rack_start_gp_measurement(tp, rack, startseq, sb_offset);
}
} else {
/*
* Persist case, update snd_max but since we are in persist
* mode (no window) we do not update snd_nxt.
*/
int32_t xlen = len;
if (error)
goto nomore;
if (flags & TH_SYN)
++xlen;
if (flags & TH_FIN) {
++xlen;
tp->t_flags |= TF_SENTFIN;
}
/* In the ENOBUFS case we do *not* update snd_max */
if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max)) {
if (tp->snd_una == tp->snd_max) {
/*
* Update the time we just added data since
* none was outstanding.
*/
rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
tp->t_acktime = ticks;
}
tp->snd_max = tp->snd_nxt + len;
}
}
nomore:
if (error) {
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
SOCKBUF_UNLOCK_ASSERT(sb); /* Check gotos. */
/*
* Failures do not advance the seq counter above. For the
* case of ENOBUFS we will fall out and retry in 1ms with
* the hpts. Everything else will just have to retransmit
* with the timer.
*
* In any case, we do not want to loop around for another
* send without a good reason.
*/
sendalot = 0;
switch (error) {
case EPERM:
tp->t_softerror = error;
return (error);
case ENOBUFS:
if (slot == 0) {
/*
* Pace us right away to retry in a some
* time
*/
slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
if (rack->rc_enobuf < 126)
rack->rc_enobuf++;
if (slot > ((rack->rc_rack_rtt / 2) * HPTS_USEC_IN_MSEC)) {
slot = (rack->rc_rack_rtt / 2) * HPTS_USEC_IN_MSEC;
}
if (slot < (10 * HPTS_USEC_IN_MSEC))
slot = 10 * HPTS_USEC_IN_MSEC;
}
counter_u64_add(rack_saw_enobuf, 1);
error = 0;
goto enobufs;
case EMSGSIZE:
/*
* For some reason the interface we used initially
* to send segments changed to another or lowered
* its MTU. If TSO was active we either got an
* interface without TSO capabilits or TSO was
* turned off. If we obtained mtu from ip_output()
* then update it and try again.
*/
if (tso)
tp->t_flags &= ~TF_TSO;
if (mtu != 0) {
tcp_mss_update(tp, -1, mtu, NULL, NULL);
goto again;
}
slot = 10 * HPTS_USEC_IN_MSEC;
rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
return (error);
case ENETUNREACH:
counter_u64_add(rack_saw_enetunreach, 1);
case EHOSTDOWN:
case EHOSTUNREACH:
case ENETDOWN:
if (TCPS_HAVERCVDSYN(tp->t_state)) {
tp->t_softerror = error;
}
/* FALLTHROUGH */
default:
slot = 10 * HPTS_USEC_IN_MSEC;
rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
return (error);
}
} else {
rack->rc_enobuf = 0;
}
KMOD_TCPSTAT_INC(tcps_sndtotal);
/*
* Data sent (as far as we can tell). If this advertises a larger
* window than any other segment, then remember the size of the
* advertised window. Any pending ACK has now been sent.
*/
if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
tp->rcv_adv = tp->rcv_nxt + recwin;
tp->last_ack_sent = tp->rcv_nxt;
tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
enobufs:
/* Assure when we leave that snd_nxt will point to top */
if (SEQ_GT(tp->snd_max, tp->snd_nxt))
tp->snd_nxt = tp->snd_max;
if (sendalot) {
/* Do we need to turn off sendalot? */
if (rack->r_ctl.rc_pace_max_segs &&
(tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
/* We hit our max. */
sendalot = 0;
} else if ((rack->rc_user_set_max_segs) &&
(tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
/* We hit the user defined max */
sendalot = 0;
}
}
if ((error == 0) && (flags & TH_FIN))
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
if (flags & TH_RST) {
/*
* We don't send again after sending a RST.
*/
slot = 0;
sendalot = 0;
if (error == 0)
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
/*
* Get our pacing rate, if an error
* occured in sending (ENOBUF) we would
* hit the else if with slot preset. Other
* errors return.
*/
slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
}
if (rsm &&
rack->use_rack_rr) {
/* Its a retransmit and we use the rack cheat? */
if ((slot == 0) ||
(rack->rc_always_pace == 0) ||
(rack->r_rr_config == 1)) {
/*
* We have no pacing set or we
* are using old-style rack or
* we are overriden to use the old 1ms pacing.
*/
slot = rack->r_ctl.rc_min_to * HPTS_USEC_IN_MSEC;
}
}
if (slot) {
/* set the rack tcb into the slot N */
counter_u64_add(rack_paced_segments, 1);
} else if (sendalot) {
if (len)
counter_u64_add(rack_unpaced_segments, 1);
sack_rxmit = 0;
goto again;
} else if (len) {
counter_u64_add(rack_unpaced_segments, 1);
}
rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
return (error);
}
static void
rack_update_seg(struct tcp_rack *rack)
{
uint32_t orig_val;
orig_val = rack->r_ctl.rc_pace_max_segs;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
if (orig_val != rack->r_ctl.rc_pace_max_segs)
rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL);
}
/*
* rack_ctloutput() must drop the inpcb lock before performing copyin on
* socket option arguments. When it re-acquires the lock after the copy, it
* has to revalidate that the connection is still valid for the socket
* option.
*/
static int
rack_set_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
{
struct epoch_tracker et;
uint64_t val;
int32_t error = 0, optval;
uint16_t ca, ss;
switch (sopt->sopt_name) {
case TCP_RACK_PROP_RATE: /* URL:prop_rate */
case TCP_RACK_PROP : /* URL:prop */
case TCP_RACK_TLP_REDUCE: /* URL:tlp_reduce */
case TCP_RACK_EARLY_RECOV: /* URL:early_recov */
case TCP_RACK_PACE_REDUCE: /* Not used */
/* Pacing related ones */
case TCP_RACK_PACE_ALWAYS: /* URL:pace_always */
case TCP_BBR_RACK_INIT_RATE: /* URL:irate */
case TCP_BBR_IWINTSO: /* URL:tso_iwin */
case TCP_RACK_PACE_MAX_SEG: /* URL:pace_max_seg */
case TCP_RACK_FORCE_MSEG: /* URL:force_max_seg */
case TCP_RACK_PACE_RATE_CA: /* URL:pr_ca */
case TCP_RACK_PACE_RATE_SS: /* URL:pr_ss*/
case TCP_RACK_PACE_RATE_REC: /* URL:pr_rec */
case TCP_RACK_GP_INCREASE_CA: /* URL:gp_inc_ca */
case TCP_RACK_GP_INCREASE_SS: /* URL:gp_inc_ss */
case TCP_RACK_GP_INCREASE_REC: /* URL:gp_inc_rec */
case TCP_RACK_RR_CONF: /* URL:rrr_conf */
case TCP_BBR_HDWR_PACE: /* URL:hdwrpace */
/* End pacing related */
case TCP_DELACK:
case TCP_RACK_PRR_SENDALOT: /* URL:prr_sendalot */
case TCP_RACK_MIN_TO: /* URL:min_to */
case TCP_RACK_EARLY_SEG: /* URL:early_seg */
case TCP_RACK_REORD_THRESH: /* URL:reord_thresh */
case TCP_RACK_REORD_FADE: /* URL:reord_fade */
case TCP_RACK_TLP_THRESH: /* URL:tlp_thresh */
case TCP_RACK_PKT_DELAY: /* URL:pkt_delay */
case TCP_RACK_TLP_USE: /* URL:tlp_use */
case TCP_RACK_TLP_INC_VAR: /* URL:tlp_inc_var */
case TCP_RACK_IDLE_REDUCE_HIGH: /* URL:idle_reduce_high */
case TCP_BBR_RACK_RTT_USE: /* URL:rttuse */
case TCP_BBR_USE_RACK_RR: /* URL:rackrr */
case TCP_RACK_DO_DETECTION: /* URL:detect */
case TCP_NO_PRR: /* URL:noprr */
case TCP_TIMELY_DYN_ADJ: /* URL:dynamic */
case TCP_DATA_AFTER_CLOSE:
case TCP_RACK_NONRXT_CFG_RATE: /* URL:nonrxtcr */
case TCP_SHARED_CWND_ENABLE: /* URL:scwnd */
case TCP_RACK_MBUF_QUEUE: /* URL:mqueue */
case TCP_RACK_NO_PUSH_AT_MAX: /* URL:npush */
case TCP_RACK_PACE_TO_FILL: /* URL:fillcw */
case TCP_SHARED_CWND_TIME_LIMIT: /* URL:lscwnd */
case TCP_RACK_PROFILE: /* URL:profile */
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
if (error)
return (error);
INP_WLOCK(inp);
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
INP_WUNLOCK(inp);
return (ECONNRESET);
}
tp = intotcpcb(inp);
rack = (struct tcp_rack *)tp->t_fb_ptr;
switch (sopt->sopt_name) {
case TCP_RACK_PROFILE:
RACK_OPTS_INC(tcp_profile);
if (optval == 1) {
/* pace_always=1 */
rack->rc_always_pace = 1;
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
/* scwnd=1 */
rack->rack_enable_scwnd = 1;
/* dynamic=100 */
rack->rc_gp_dyn_mul = 1;
rack->r_ctl.rack_per_of_gp_ca = 100;
/* rrr_conf=3 */
rack->r_rr_config = 3;
/* npush=2 */
rack->r_ctl.rc_no_push_at_mrtt = 2;
/* fillcw=1 */
rack->rc_pace_to_cwnd = 1;
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
/* noprr=1 */
rack->rack_no_prr = 1;
/* lscwnd=1 */
rack->r_limit_scw = 1;
} else if (optval == 2) {
/* pace_always=1 */
rack->rc_always_pace = 1;
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
/* scwnd=1 */
rack->rack_enable_scwnd = 1;
/* dynamic=100 */
rack->rc_gp_dyn_mul = 1;
rack->r_ctl.rack_per_of_gp_ca = 100;
/* rrr_conf=3 */
rack->r_rr_config = 3;
/* npush=2 */
rack->r_ctl.rc_no_push_at_mrtt = 2;
/* fillcw=1 */
rack->rc_pace_to_cwnd = 1;
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
/* noprr=1 */
rack->rack_no_prr = 1;
/* lscwnd=0 */
rack->r_limit_scw = 0;
}
break;
case TCP_SHARED_CWND_TIME_LIMIT:
RACK_OPTS_INC(tcp_lscwnd);
if (optval)
rack->r_limit_scw = 1;
else
rack->r_limit_scw = 0;
break;
case TCP_RACK_PACE_TO_FILL:
RACK_OPTS_INC(tcp_fillcw);
if (optval == 0)
rack->rc_pace_to_cwnd = 0;
else
rack->rc_pace_to_cwnd = 1;
if ((optval >= rack_gp_rtt_maxmul) &&
rack_gp_rtt_maxmul &&
(optval < 0xf)) {
rack->rc_pace_fill_if_rttin_range = 1;
rack->rtt_limit_mul = optval;
} else {
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
}
break;
case TCP_RACK_NO_PUSH_AT_MAX:
RACK_OPTS_INC(tcp_npush);
if (optval == 0)
rack->r_ctl.rc_no_push_at_mrtt = 0;
else if (optval < 0xff)
rack->r_ctl.rc_no_push_at_mrtt = optval;
else
error = EINVAL;
break;
case TCP_SHARED_CWND_ENABLE:
RACK_OPTS_INC(tcp_rack_scwnd);
if (optval == 0)
rack->rack_enable_scwnd = 0;
else
rack->rack_enable_scwnd = 1;
break;
case TCP_RACK_MBUF_QUEUE:
/* Now do we use the LRO mbuf-queue feature */
RACK_OPTS_INC(tcp_rack_mbufq);
if (optval)
rack->r_mbuf_queue = 1;
else
rack->r_mbuf_queue = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
break;
case TCP_RACK_NONRXT_CFG_RATE:
RACK_OPTS_INC(tcp_rack_cfg_rate);
if (optval == 0)
rack->rack_rec_nonrxt_use_cr = 0;
else
rack->rack_rec_nonrxt_use_cr = 1;
break;
case TCP_NO_PRR:
RACK_OPTS_INC(tcp_rack_noprr);
if (optval == 0)
rack->rack_no_prr = 0;
else
rack->rack_no_prr = 1;
break;
case TCP_TIMELY_DYN_ADJ:
RACK_OPTS_INC(tcp_timely_dyn);
if (optval == 0)
rack->rc_gp_dyn_mul = 0;
else {
rack->rc_gp_dyn_mul = 1;
if (optval >= 100) {
/*
* If the user sets something 100 or more
* its the gp_ca value.
*/
rack->r_ctl.rack_per_of_gp_ca = optval;
}
}
break;
case TCP_RACK_DO_DETECTION:
RACK_OPTS_INC(tcp_rack_do_detection);
if (optval == 0)
rack->do_detection = 0;
else
rack->do_detection = 1;
break;
case TCP_RACK_PROP_RATE:
if ((optval <= 0) || (optval >= 100)) {
error = EINVAL;
break;
}
RACK_OPTS_INC(tcp_rack_prop_rate);
rack->r_ctl.rc_prop_rate = optval;
break;
case TCP_RACK_TLP_USE:
if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
error = EINVAL;
break;
}
RACK_OPTS_INC(tcp_tlp_use);
rack->rack_tlp_threshold_use = optval;
break;
case TCP_RACK_PROP:
/* RACK proportional rate reduction (bool) */
RACK_OPTS_INC(tcp_rack_prop);
rack->r_ctl.rc_prop_reduce = optval;
break;
case TCP_RACK_TLP_REDUCE:
/* RACK TLP cwnd reduction (bool) */
RACK_OPTS_INC(tcp_rack_tlp_reduce);
rack->r_ctl.rc_tlp_cwnd_reduce = optval;
break;
case TCP_RACK_EARLY_RECOV:
/* Should recovery happen early (bool) */
RACK_OPTS_INC(tcp_rack_early_recov);
rack->r_ctl.rc_early_recovery = optval;
break;
/* Pacing related ones */
case TCP_RACK_PACE_ALWAYS:
/*
* zero is old rack method, 1 is new
* method using a pacing rate.
*/
RACK_OPTS_INC(tcp_rack_pace_always);
if (optval > 0)
rack->rc_always_pace = 1;
else
rack->rc_always_pace = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
/* A rate may be set irate or other, if so set seg size */
rack_update_seg(rack);
break;
case TCP_BBR_RACK_INIT_RATE:
RACK_OPTS_INC(tcp_initial_rate);
val = optval;
/* Change from kbits per second to bytes per second */
val *= 1000;
val /= 8;
rack->r_ctl.init_rate = val;
if (rack->rc_init_win != rack_default_init_window) {
uint32_t win, snt;
/*
* Options don't always get applied
* in the order you think. So in order
* to assure we update a cwnd we need
* to check and see if we are still
* where we should raise the cwnd.
*/
win = rc_init_window(rack);
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
if ((snt < win) &&
(tp->snd_cwnd < win))
tp->snd_cwnd = win;
}
if (rack->rc_always_pace)
rack_update_seg(rack);
break;
case TCP_BBR_IWINTSO:
RACK_OPTS_INC(tcp_initial_win);
if (optval && (optval <= 0xff)) {
uint32_t win, snt;
rack->rc_init_win = optval;
win = rc_init_window(rack);
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
if ((snt < win) &&
(tp->t_srtt |
#ifdef NETFLIX_PEAKRATE
tp->t_maxpeakrate |
#endif
rack->r_ctl.init_rate)) {
/*
* We are not past the initial window
* and we have some bases for pacing,
* so we need to possibly adjust up
* the cwnd. Note even if we don't set
* the cwnd, its still ok to raise the rc_init_win
* which can be used coming out of idle when we
* would have a rate.
*/
if (tp->snd_cwnd < win)
tp->snd_cwnd = win;
}
if (rack->rc_always_pace)
rack_update_seg(rack);
} else
error = EINVAL;
break;
case TCP_RACK_FORCE_MSEG:
RACK_OPTS_INC(tcp_rack_force_max_seg);
if (optval)
rack->rc_force_max_seg = 1;
else
rack->rc_force_max_seg = 0;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments size in a pace in bytes */
RACK_OPTS_INC(tcp_rack_max_seg);
rack->rc_user_set_max_segs = optval;
rack_set_pace_segments(tp, rack, __LINE__);
break;
case TCP_RACK_PACE_RATE_REC:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_rec);
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_PACE_RATE_SS:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_ss);
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_PACE_RATE_CA:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_ca);
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_REC:
RACK_OPTS_INC(tcp_gp_inc_rec);
rack->r_ctl.rack_per_of_gp_rec = optval;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_CA:
RACK_OPTS_INC(tcp_gp_inc_ca);
ca = optval;
if (ca < 100) {
/*
* We don't allow any reduction
* over the GP b/w.
*/
error = EINVAL;
break;
}
rack->r_ctl.rack_per_of_gp_ca = ca;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_SS:
RACK_OPTS_INC(tcp_gp_inc_ss);
ss = optval;
if (ss < 100) {
/*
* We don't allow any reduction
* over the GP b/w.
*/
error = EINVAL;
break;
}
rack->r_ctl.rack_per_of_gp_ss = ss;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_RR_CONF:
RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
if (optval && optval <= 3)
rack->r_rr_config = optval;
else
rack->r_rr_config = 0;
break;
case TCP_BBR_HDWR_PACE:
RACK_OPTS_INC(tcp_hdwr_pacing);
if (optval){
if (rack->rack_hdrw_pacing == 0) {
rack->rack_hdw_pace_ena = 1;
rack->rack_attempt_hdwr_pace = 0;
} else
error = EALREADY;
} else {
rack->rack_hdw_pace_ena = 0;
#ifdef RATELIMIT
if (rack->rack_hdrw_pacing) {
rack->rack_hdrw_pacing = 0;
in_pcbdetach_txrtlmt(rack->rc_inp);
}
#endif
}
break;
/* End Pacing related ones */
case TCP_RACK_PRR_SENDALOT:
/* Allow PRR to send more than one seg */
RACK_OPTS_INC(tcp_rack_prr_sendalot);
rack->r_ctl.rc_prr_sendalot = optval;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
RACK_OPTS_INC(tcp_rack_min_to);
rack->r_ctl.rc_min_to = optval;
break;
case TCP_RACK_EARLY_SEG:
/* If early recovery max segments */
RACK_OPTS_INC(tcp_rack_early_seg);
rack->r_ctl.rc_early_recovery_segs = optval;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
RACK_OPTS_INC(tcp_rack_reord_thresh);
if ((optval > 0) && (optval < 31))
rack->r_ctl.rc_reorder_shift = optval;
else
error = EINVAL;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
RACK_OPTS_INC(tcp_rack_reord_fade);
rack->r_ctl.rc_reorder_fade = optval;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
RACK_OPTS_INC(tcp_rack_tlp_thresh);
if (optval)
rack->r_ctl.rc_tlp_threshold = optval;
else
error = EINVAL;
break;
case TCP_BBR_USE_RACK_RR:
RACK_OPTS_INC(tcp_rack_rr);
if (optval)
rack->use_rack_rr = 1;
else
rack->use_rack_rr = 0;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
RACK_OPTS_INC(tcp_rack_pkt_delay);
rack->r_ctl.rc_pkt_delay = optval;
break;
case TCP_RACK_TLP_INC_VAR:
/* Does TLP include rtt variance in t-o */
error = EINVAL;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
error = EINVAL;
break;
case TCP_DELACK:
if (optval == 0)
tp->t_delayed_ack = 0;
else
tp->t_delayed_ack = 1;
if (tp->t_flags & TF_DELACK) {
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
NET_EPOCH_ENTER(et);
rack_output(tp);
NET_EPOCH_EXIT(et);
}
break;
case TCP_BBR_RACK_RTT_USE:
if ((optval != USE_RTT_HIGH) &&
(optval != USE_RTT_LOW) &&
(optval != USE_RTT_AVG))
error = EINVAL;
else
rack->r_ctl.rc_rate_sample_method = optval;
break;
case TCP_DATA_AFTER_CLOSE:
if (optval)
rack->rc_allow_data_af_clo = 1;
else
rack->rc_allow_data_af_clo = 0;
break;
case TCP_RACK_PACE_REDUCE:
/* sysctl only now */
error = EINVAL;
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
#ifdef NETFLIX_STATS
tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
#endif
INP_WUNLOCK(inp);
return (error);
}
static int
rack_get_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
{
int32_t error, optval;
uint64_t val;
/*
* Because all our options are either boolean or an int, we can just
* pull everything into optval and then unlock and copy. If we ever
* add a option that is not a int, then this will have quite an
* impact to this routine.
*/
error = 0;
switch (sopt->sopt_name) {
case TCP_RACK_PROFILE:
/* You cannot retrieve a profile, its write only */
error = EINVAL;
break;
case TCP_RACK_PACE_TO_FILL:
optval = rack->rc_pace_to_cwnd;
break;
case TCP_RACK_NO_PUSH_AT_MAX:
optval = rack->r_ctl.rc_no_push_at_mrtt;
break;
case TCP_SHARED_CWND_ENABLE:
optval = rack->rack_enable_scwnd;
break;
case TCP_RACK_NONRXT_CFG_RATE:
optval = rack->rack_rec_nonrxt_use_cr;
break;
case TCP_NO_PRR:
optval = rack->rack_no_prr;
break;
case TCP_RACK_DO_DETECTION:
optval = rack->do_detection;
break;
case TCP_RACK_MBUF_QUEUE:
/* Now do we use the LRO mbuf-queue feature */
optval = rack->r_mbuf_queue;
break;
case TCP_TIMELY_DYN_ADJ:
optval = rack->rc_gp_dyn_mul;
break;
case TCP_BBR_IWINTSO:
optval = rack->rc_init_win;
break;
case TCP_RACK_PROP_RATE:
optval = rack->r_ctl.rc_prop_rate;
break;
case TCP_RACK_PROP:
/* RACK proportional rate reduction (bool) */
optval = rack->r_ctl.rc_prop_reduce;
break;
case TCP_RACK_TLP_REDUCE:
/* RACK TLP cwnd reduction (bool) */
optval = rack->r_ctl.rc_tlp_cwnd_reduce;
break;
case TCP_RACK_EARLY_RECOV:
/* Should recovery happen early (bool) */
optval = rack->r_ctl.rc_early_recovery;
break;
case TCP_RACK_PACE_REDUCE:
/* RACK Hptsi reduction factor (divisor) */
error = EINVAL;
break;
case TCP_BBR_RACK_INIT_RATE:
val = rack->r_ctl.init_rate;
/* convert to kbits per sec */
val *= 8;
val /= 1000;
optval = (uint32_t)val;
break;
case TCP_RACK_FORCE_MSEG:
optval = rack->rc_force_max_seg;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments in a pace */
optval = rack->rc_user_set_max_segs;
break;
case TCP_RACK_PACE_ALWAYS:
/* Use the always pace method */
optval = rack->rc_always_pace;
break;
case TCP_RACK_PRR_SENDALOT:
/* Allow PRR to send more than one seg */
optval = rack->r_ctl.rc_prr_sendalot;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
optval = rack->r_ctl.rc_min_to;
break;
case TCP_RACK_EARLY_SEG:
/* If early recovery max segments */
optval = rack->r_ctl.rc_early_recovery_segs;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
optval = rack->r_ctl.rc_reorder_shift;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
optval = rack->r_ctl.rc_reorder_fade;
break;
case TCP_BBR_USE_RACK_RR:
/* Do we use the rack cheat for rxt */
optval = rack->use_rack_rr;
break;
case TCP_RACK_RR_CONF:
optval = rack->r_rr_config;
break;
case TCP_BBR_HDWR_PACE:
optval = rack->rack_hdw_pace_ena;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
optval = rack->r_ctl.rc_tlp_threshold;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
optval = rack->r_ctl.rc_pkt_delay;
break;
case TCP_RACK_TLP_USE:
optval = rack->rack_tlp_threshold_use;
break;
case TCP_RACK_TLP_INC_VAR:
/* Does TLP include rtt variance in t-o */
error = EINVAL;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
error = EINVAL;
break;
case TCP_RACK_PACE_RATE_CA:
optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
break;
case TCP_RACK_PACE_RATE_SS:
optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
break;
case TCP_RACK_PACE_RATE_REC:
optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
break;
case TCP_RACK_GP_INCREASE_SS:
optval = rack->r_ctl.rack_per_of_gp_ca;
break;
case TCP_RACK_GP_INCREASE_CA:
optval = rack->r_ctl.rack_per_of_gp_ss;
break;
case TCP_BBR_RACK_RTT_USE:
optval = rack->r_ctl.rc_rate_sample_method;
break;
case TCP_DELACK:
optval = tp->t_delayed_ack;
break;
case TCP_DATA_AFTER_CLOSE:
optval = rack->rc_allow_data_af_clo;
break;
case TCP_SHARED_CWND_TIME_LIMIT:
optval = rack->r_limit_scw;
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
if (error == 0) {
error = sooptcopyout(sopt, &optval, sizeof optval);
}
return (error);
}
static int
rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
{
int32_t error = EINVAL;
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack == NULL) {
/* Huh? */
goto out;
}
if (sopt->sopt_dir == SOPT_SET) {
return (rack_set_sockopt(so, sopt, inp, tp, rack));
} else if (sopt->sopt_dir == SOPT_GET) {
return (rack_get_sockopt(so, sopt, inp, tp, rack));
}
out:
INP_WUNLOCK(inp);
return (error);
}
static int
rack_pru_options(struct tcpcb *tp, int flags)
{
if (flags & PRUS_OOB)
return (EOPNOTSUPP);
return (0);
}
static struct tcp_function_block __tcp_rack = {
.tfb_tcp_block_name = __XSTRING(STACKNAME),
.tfb_tcp_output = rack_output,
.tfb_do_queued_segments = ctf_do_queued_segments,
.tfb_do_segment_nounlock = rack_do_segment_nounlock,
.tfb_tcp_do_segment = rack_do_segment,
.tfb_tcp_ctloutput = rack_ctloutput,
.tfb_tcp_fb_init = rack_init,
.tfb_tcp_fb_fini = rack_fini,
.tfb_tcp_timer_stop_all = rack_stopall,
.tfb_tcp_timer_activate = rack_timer_activate,
.tfb_tcp_timer_active = rack_timer_active,
.tfb_tcp_timer_stop = rack_timer_stop,
.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
.tfb_tcp_handoff_ok = rack_handoff_ok,
.tfb_pru_options = rack_pru_options,
};
static const char *rack_stack_names[] = {
__XSTRING(STACKNAME),
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#endif
};
static int
rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
{
memset(mem, 0, size);
return (0);
}
static void
rack_dtor(void *mem, int32_t size, void *arg)
{
}
static bool rack_mod_inited = false;
static int
tcp_addrack(module_t mod, int32_t type, void *data)
{
int32_t err = 0;
int num_stacks;
switch (type) {
case MOD_LOAD:
rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
sizeof(struct rack_sendmap),
rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
sizeof(struct tcp_rack),
rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
sysctl_ctx_init(&rack_sysctl_ctx);
rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
OID_AUTO,
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#else
__XSTRING(STACKNAME),
#endif
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
if (rack_sysctl_root == NULL) {
printf("Failed to add sysctl node\n");
err = EFAULT;
goto free_uma;
}
rack_init_sysctls();
num_stacks = nitems(rack_stack_names);
err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
rack_stack_names, &num_stacks);
if (err) {
printf("Failed to register %s stack name for "
"%s module\n", rack_stack_names[num_stacks],
__XSTRING(MODNAME));
sysctl_ctx_free(&rack_sysctl_ctx);
free_uma:
uma_zdestroy(rack_zone);
uma_zdestroy(rack_pcb_zone);
rack_counter_destroy();
printf("Failed to register rack module -- err:%d\n", err);
return (err);
}
tcp_lro_reg_mbufq();
rack_mod_inited = true;
break;
case MOD_QUIESCE:
err = deregister_tcp_functions(&__tcp_rack, true, false);
break;
case MOD_UNLOAD:
err = deregister_tcp_functions(&__tcp_rack, false, true);
if (err == EBUSY)
break;
if (rack_mod_inited) {
uma_zdestroy(rack_zone);
uma_zdestroy(rack_pcb_zone);
sysctl_ctx_free(&rack_sysctl_ctx);
rack_counter_destroy();
rack_mod_inited = false;
}
tcp_lro_dereg_mbufq();
err = 0;
break;
default:
return (EOPNOTSUPP);
}
return (err);
}
static moduledata_t tcp_rack = {
.name = __XSTRING(MODNAME),
.evhand = tcp_addrack,
.priv = 0
};
MODULE_VERSION(MODNAME, 1);
DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
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