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freebsd-dev/sys/netinet/tcp_stacks/rack.c
Michael Tuexen c6dcb64b18 Use exponential backoff for retransmitting SYN segments as specified 
in the TCP RFCs.

Reviewed by:		rrs@, Richard Scheffenegger
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18974
2019-02-20 17:56:38 +00:00

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/*-
* Copyright (c) 2016-2018 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 <sys/param.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>
#include <sys/sysctl.h>
#include <sys/systm.h>
#ifdef NETFLIX_STATS
#include <sys/stats.h>
#endif
#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/smp.h>
#include <sys/kthread.h>
#include <sys/kern_prefetch.h>
#include <vm/uma.h>
#include <net/route.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/tcpip.h>
#include <netinet/cc/cc.h>
#ifdef NETFLIX_CWV
#include <netinet/tcp_newcwv.h>
#endif
#include <netinet/tcp_fastopen.h>
#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_precache = 1;
static int32_t rack_tlp_thresh = 1;
static int32_t rack_reorder_thresh = 2;
static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000
* - 60 seconds */
static int32_t rack_pkt_delay = 1;
static int32_t rack_inc_var = 0;/* For TLP */
static int32_t rack_reduce_largest_on_idle = 0;
static int32_t rack_min_pace_time = 0;
static int32_t rack_min_pace_time_seg_req=6;
static int32_t rack_early_recovery = 1;
static int32_t rack_early_recovery_max_seg = 6;
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_tlp_in_recovery = 1; /* Can we do TLP in recovery? */
static int32_t rack_verbose_logging = 0;
static int32_t rack_ignore_data_after_close = 1;
/*
* 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 int32_t rack_tlp_min = 10;
static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */
static int32_t rack_rto_max = 30000; /* 30 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 = 1;
static int32_t rack_delayed_ack_time = 200; /* 200ms */
static int32_t rack_slot_reduction = 4;
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_sack_block_limit = 128;
static int32_t rack_use_sack_filter = 1;
static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
/* 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_saw_enobuf;
counter_u64_t rack_saw_enetunreach;
/* 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_sack_proc_all;
counter_u64_t rack_sack_proc_short;
counter_u64_t rack_sack_proc_restart;
counter_u64_t rack_runt_sacks;
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_tlp_does_nada;
/* 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_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_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 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 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);
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);
static int32_t rack_output(struct tcpcb *tp);
static void
rack_hpts_do_segment(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);
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);
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);
static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
static void
rack_challenge_ack(struct mbuf *m, struct tcphdr *th,
struct tcpcb *tp, int32_t * ret_val);
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);
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);
static void
rack_do_drop(struct mbuf *m, struct tcpcb *tp);
static void
rack_do_dropafterack(struct mbuf *m, struct tcpcb *tp,
struct tcphdr *th, int32_t thflags, int32_t tlen, int32_t * ret_val);
static void
rack_do_dropwithreset(struct mbuf *m, struct tcpcb *tp,
struct tcphdr *th, int32_t rstreason, int32_t tlen);
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);
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);
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);
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);
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);
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);
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);
static int
rack_drop_checks(struct tcpopt *to, struct mbuf *m,
struct tcphdr *th, struct tcpcb *tp, int32_t * tlenp, int32_t * thf,
int32_t * drop_hdrlen, int32_t * ret_val);
static int
rack_process_rst(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp);
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);
static void
tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th);
static int
rack_ts_check(struct mbuf *m, struct tcphdr *th,
struct tcpcb *tp, int32_t tlen, int32_t thflags, int32_t * ret_val);
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_unpaced_segments);
counter_u64_zero(rack_saw_enobuf);
counter_u64_zero(rack_saw_enetunreach);
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_find_high);
counter_u64_zero(rack_runt_sacks);
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);
}
rack_clear_counter = 0;
return (0);
}
static void
rack_init_sysctls()
{
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, "data_after_close", CTLFLAG_RW,
&rack_ignore_data_after_close, 0,
"Do we hold off sending a RST until all pending data is ack'd");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "min_pace_time", CTLFLAG_RW,
&rack_min_pace_time, 0,
"Should we enforce a minimum pace time of 1ms");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "min_pace_segs", CTLFLAG_RW,
&rack_min_pace_time_seg_req, 6,
"How many segments have to be in the len to enforce min-pace-time");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "idle_reduce_high", CTLFLAG_RW,
&rack_reduce_largest_on_idle, 0,
"Should we reduce the largest cwnd seen to IW on idle reduction");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "sackfiltering", CTLFLAG_RW,
&rack_use_sack_filter, 1,
"Do we use sack filtering?");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "delayed_ack", CTLFLAG_RW,
&rack_delayed_ack_time, 200,
"Delayed ack time (200ms)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "precache", CTLFLAG_RW,
&rack_precache, 0,
"Where should we precache the mcopy (0 is not at all)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "sblklimit", CTLFLAG_RW,
&rack_sack_block_limit, 128,
"When do we start paying attention to small sack blocks");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "send_oldest", CTLFLAG_RW,
&rack_always_send_oldest, 1,
"Should we always send the oldest TLP and RACK-TLP");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "rack_tlp_in_recovery", CTLFLAG_RW,
&rack_tlp_in_recovery, 1,
"Can we do a TLP during recovery?");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
OID_AUTO, "recovery_prop", CTLFLAG_RW,
&rack_proportional_rate, 10,
"What percent reduction per loss");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "hptsi_reduces", CTLFLAG_RW,
&rack_slot_reduction, 4,
"When setting a slot should we reduce by divisor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "hptsi_every_seg", CTLFLAG_RW,
&rack_pace_every_seg, 1,
"Should we pace out every segment hptsi");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "hptsi_seg_max", CTLFLAG_RW,
&rack_hptsi_segments, 6,
"Should we pace out only a limited size of segments");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "minto", CTLFLAG_RW,
&rack_min_to, 1,
"Minimum rack timeout in milliseconds");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "earlyrecoveryseg", CTLFLAG_RW,
&rack_early_recovery_max_seg, 6,
"Max segments in early recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "earlyrecovery", CTLFLAG_RW,
&rack_early_recovery, 1,
"Do we do early recovery with rack");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
OID_AUTO, "pktdelay", CTLFLAG_RW,
&rack_pkt_delay, 1,
"Extra RACK time (in ms) besides reordering thresh");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "inc_var", CTLFLAG_RW,
&rack_inc_var, 0,
"Should rack add to the TLP timer the variance in rtt calculation");
rack_badfr = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
OID_AUTO, "arm_tlp", CTLFLAG_RD,
&rack_to_arm_tlp,
"Total number of times the tlp timer armed?");
rack_paced_segments = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
OID_AUTO, "allocemerg", CTLFLAG_RD,
&rack_to_alloc_emerg,
"Total alocations done from emergency cache");
rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
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_sysctl_root),
OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
&rack_used_tlpmethod2,
"Total number of runt sacks 2");
rack_runt_sacks = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "runtsacks", CTLFLAG_RD,
&rack_runt_sacks,
"Total number of runt sacks");
rack_progress_drops = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
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_sysctl_root),
OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
&rack_input_idle_reduces,
"Total number of idle reductions on input");
rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "tlp_nada", CTLFLAG_RD,
&rack_tlp_does_nada,
"Total number of nada tlp calls");
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 int32_t
rack_progress_timeout_check(struct tcpcb *tp)
{
if (tp->t_maxunacktime && tp->t_acktime && TSTMP_GT(ticks, tp->t_acktime)) {
if ((ticks - tp->t_acktime) >= tp->t_maxunacktime) {
/*
* There is an assumption that the caller
* will drop the connection so we will
* increment the counters here.
*/
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
counter_u64_add(rack_progress_drops, 1);
#ifdef NETFLIX_STATS
TCPSTAT_INC(tcps_progdrops);
#endif
rack_log_progress_event(rack, tp, ticks, PROGRESS_DROP, __LINE__);
return (1);
}
}
return (0);
}
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;
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;
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.flex8 = which;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
TCP_LOG_EVENT(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);
}
}
static void
rack_log_to_event(struct tcp_rack *rack, int32_t to_num)
{
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.flex8 = to_num;
log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
log.u_bbr.flex2 = rack->rc_rack_rtt;
TCP_LOG_EVENT(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);
}
}
static void
rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, int32_t t,
uint32_t o_srtt, uint32_t o_var)
{
if (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 = t;
log.u_bbr.flex2 = o_srtt;
log.u_bbr.flex3 = o_var;
log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt;
log.u_bbr.rttProp = rack->r_ctl.rack_rs.rs_rtt_tot;
log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
TCP_LOG_EVENT(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRRTT, 0,
0, &log, false);
}
}
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 */
log.u_bbr.flex1 = rtt * 1000;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
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;
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;
TCP_LOG_EVENT(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_PROGRESS, 0,
0, &log, false);
}
}
static void
rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts)
{
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;
log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
log.u_bbr.flex8 = rack->rc_in_persist;
TCP_LOG_EVENT(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);
}
}
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;
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;
log.u_bbr.flex7 = rack->r_wanted_output;
log.u_bbr.flex8 = rack->rc_in_persist;
TCP_LOG_EVENT(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);
}
}
static void
rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot, uint8_t hpts_calling)
{
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;
log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex7 = hpts_calling;
log.u_bbr.flex8 = rack->rc_in_persist;
TCP_LOG_EVENT(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);
}
}
static void
rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line)
{
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 = 0;
log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = 0;
log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
log.u_bbr.flex8 = hpts_removed;
TCP_LOG_EVENT(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);
}
}
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;
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;
TCP_LOG_EVENT(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);
}
}
static void
rack_counter_destroy()
{
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_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_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_hard);
counter_u64_free(rack_to_alloc_emerg);
counter_u64_free(rack_sack_proc_all);
counter_u64_free(rack_sack_proc_short);
counter_u64_free(rack_sack_proc_restart);
counter_u64_free(rack_to_alloc);
counter_u64_free(rack_find_high);
counter_u64_free(rack_runt_sacks);
counter_u64_free(rack_enter_tlp_calc);
counter_u64_free(rack_used_tlpmethod);
counter_u64_free(rack_used_tlpmethod2);
counter_u64_free(rack_progress_drops);
counter_u64_free(rack_input_idle_reduces);
counter_u64_free(rack_tlp_does_nada);
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;
counter_u64_add(rack_to_alloc, 1);
rack->r_ctl.rc_num_maps_alloced++;
rsm = uma_zalloc(rack_zone, M_NOWAIT);
if (rsm) {
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_next);
rack->rc_free_cnt--;
return (rsm);
}
return (NULL);
}
static void
rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
rack->r_ctl.rc_num_maps_alloced--;
if (rack->r_ctl.rc_tlpsend == rsm)
rack->r_ctl.rc_tlpsend = NULL;
if (rack->r_ctl.rc_next == rsm)
rack->r_ctl.rc_next = 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_next);
rack->rc_free_cnt++;
return;
}
uma_zfree(rack_zone, rsm);
}
/*
* 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)
{
#ifdef NETFLIX_STATS
int32_t gput;
#endif
#ifdef NETFLIX_CWV
u_long old_cwnd = tp->snd_cwnd;
#endif
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 * tp->t_maxseg;
if (tp->ccv->bytes_this_ack > max) {
tp->ccv->bytes_this_ack = max;
}
}
if (tp->snd_cwnd <= tp->snd_wnd)
tp->ccv->flags |= CCF_CWND_LIMITED;
else
tp->ccv->flags &= ~CCF_CWND_LIMITED;
if (type == CC_ACK) {
#ifdef NETFLIX_STATS
stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
((int32_t) tp->snd_cwnd) - tp->snd_wnd);
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GEQ(th->th_ack, tp->gput_ack)) {
gput = (((int64_t) (th->th_ack - tp->gput_seq)) << 3) /
max(1, tcp_ts_getticks() - tp->gput_ts);
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);
tp->t_flags &= ~TF_GPUTINPROG;
tp->t_stats_gput_prev = gput;
#ifdef NETFLIX_CWV
if (tp->t_maxpeakrate) {
/*
* We update t_peakrate_thr. This gives us roughly
* one update per round trip time.
*/
tcp_update_peakrate_thr(tp);
}
#endif
}
#endif
if (tp->snd_cwnd > tp->snd_ssthresh) {
tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
nsegs * V_tcp_abc_l_var * tp->t_maxseg);
if (tp->t_bytes_acked >= tp->snd_cwnd) {
tp->t_bytes_acked -= tp->snd_cwnd;
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 NETFLIX_STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, tp->snd_cwnd);
#endif
if (rack->r_ctl.rc_rack_largest_cwnd < tp->snd_cwnd) {
rack->r_ctl.rc_rack_largest_cwnd = tp->snd_cwnd;
}
#ifdef NETFLIX_CWV
if (tp->cwv_enabled) {
/*
* Per RFC 7661: The behaviour in the non-validated phase is
* specified as: o A sender determines whether to increase
* the cwnd based upon whether it is cwnd-limited (see
* Section 4.5.3): * A sender that is cwnd-limited MAY use
* the standard TCP method to increase cwnd (i.e., the
* standard method permits a TCP sender that fully utilises
* the cwnd to increase the cwnd each time it receives an
* ACK). * A sender that is not cwnd-limited MUST NOT
* increase the cwnd when ACK packets are received in this
* phase (i.e., needs to avoid growing the cwnd when it has
* not recently sent using the current size of cwnd).
*/
if ((tp->snd_cwnd > old_cwnd) &&
(tp->cwv_cwnd_valid == 0) &&
(!(tp->ccv->flags & CCF_CWND_LIMITED))) {
tp->snd_cwnd = old_cwnd;
}
/* Try to update pipeAck and NCWV state */
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
!IN_RECOVERY(tp->t_flags)) {
uint32_t data = sbavail(&(tp->t_inpcb->inp_socket->so_snd));
tcp_newcwv_update_pipeack(tp, data);
}
}
/* we enforce max peak rate if it is set. */
if (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 (rack->r_ctl.rc_prr_sndcnt > 0)
rack->r_wanted_output++;
}
static void
rack_post_recovery(struct tcpcb *tp, struct tcphdr *th)
{
struct tcp_rack *rack;
INP_WLOCK_ASSERT(tp->t_inpcb);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (CC_ALGO(tp)->post_recovery != NULL) {
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->post_recovery(tp->ccv);
}
/*
* Here we can in theory adjust cwnd to be based on the number of
* losses in the window (rack->r_ctl.rc_loss_count). This is done
* based on the rack_use_proportional flag.
*/
if (rack->r_ctl.rc_prop_reduce && rack->r_ctl.rc_prop_rate) {
int32_t reduce;
reduce = (rack->r_ctl.rc_loss_count * rack->r_ctl.rc_prop_rate);
if (reduce > 50) {
reduce = 50;
}
tp->snd_cwnd -= ((reduce * tp->snd_cwnd) / 100);
} else {
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->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;
}
EXIT_RECOVERY(tp->t_flags);
#ifdef NETFLIX_CWV
if (tp->cwv_enabled) {
if ((tp->cwv_cwnd_valid == 0) &&
(tp->snd_cwv.in_recovery))
tcp_newcwv_end_recovery(tp);
}
#endif
}
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:
/* rack->r_ctl.rc_ssthresh_set = 1;*/
if (!IN_FASTRECOVERY(tp->t_flags)) {
rack->r_ctl.rc_tlp_rtx_out = 0;
rack->r_ctl.rc_prr_delivered = 0;
rack->r_ctl.rc_prr_out = 0;
rack->r_ctl.rc_loss_count = 0;
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
tp->snd_recover = tp->snd_max;
if (tp->t_flags & TF_ECN_PERMIT)
tp->t_flags |= TF_ECN_SND_CWR;
}
break;
case CC_ECN:
if (!IN_CONGRECOVERY(tp->t_flags)) {
TCPSTAT_INC(tcps_ecn_rcwnd);
tp->snd_recover = tp->snd_max;
if (tp->t_flags & TF_ECN_PERMIT)
tp->t_flags |= TF_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, tp->snd_cwnd) / 2 /
tp->t_maxseg) * tp->t_maxseg;
tp->snd_cwnd = tp->t_maxseg;
break;
case CC_RTO_ERR:
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);
if (tp->t_flags & TF_WASCRECOVERY)
ENTER_CONGRECOVERY(tp->t_flags);
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
break;
}
if (CC_ALGO(tp)->cong_signal != NULL) {
if (th != NULL)
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->cong_signal(tp->ccv, type);
}
#ifdef NETFLIX_CWV
if (tp->cwv_enabled) {
if (tp->snd_cwv.in_recovery == 0 && IN_RECOVERY(tp->t_flags)) {
tcp_newcwv_enter_recovery(tp);
}
if (type == CC_RTO) {
tcp_newcwv_reset(tp);
}
}
#endif
}
static inline void
rack_cc_after_idle(struct tcpcb *tp, int reduce_largest)
{
uint32_t i_cwnd;
INP_WLOCK_ASSERT(tp->t_inpcb);
#ifdef NETFLIX_STATS
TCPSTAT_INC(tcps_idle_restarts);
if (tp->t_state == TCPS_ESTABLISHED)
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 = tcp_compute_initwnd(tcp_maxseg(tp));
if (reduce_largest) {
/*
* Do we reduce the largest cwnd to make
* rack play nice on restart hptsi wise?
*/
if (((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rack_largest_cwnd > i_cwnd)
((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rack_largest_cwnd = i_cwnd;
}
/*
* 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 inline void
rack_calc_rwin(struct socket *so, struct tcpcb *tp)
{
int32_t win;
/*
* Calculate amount of space in receive window, and then do TCP
* input processing. Receive window is amount of space in rcv queue,
* but not less than advertised window.
*/
win = sbspace(&so->so_rcv);
if (win < 0)
win = 0;
tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));
}
static void
rack_do_drop(struct mbuf *m, struct tcpcb *tp)
{
/*
* Drop space held by incoming segment and return.
*/
if (tp != NULL)
INP_WUNLOCK(tp->t_inpcb);
if (m)
m_freem(m);
}
static void
rack_do_dropwithreset(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th,
int32_t rstreason, int32_t tlen)
{
if (tp != NULL) {
tcp_dropwithreset(m, th, tp, tlen, rstreason);
INP_WUNLOCK(tp->t_inpcb);
} else
tcp_dropwithreset(m, th, NULL, tlen, rstreason);
}
/*
* The value in ret_val informs the caller
* if we dropped the tcb (and lock) or not.
* 1 = we dropped it, 0 = the TCB is still locked
* and valid.
*/
static void
rack_do_dropafterack(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th, int32_t thflags, int32_t tlen, int32_t * ret_val)
{
/*
* Generate an ACK dropping incoming segment if it occupies sequence
* space, where the ACK reflects our state.
*
* We can now skip the test for the RST flag since all paths to this
* code happen after packets containing RST have been dropped.
*
* In the SYN-RECEIVED state, don't send an ACK unless the segment
* we received passes the SYN-RECEIVED ACK test. If it fails send a
* RST. This breaks the loop in the "LAND" DoS attack, and also
* prevents an ACK storm between two listening ports that have been
* sent forged SYN segments, each with the source address of the
* other.
*/
struct tcp_rack *rack;
if (tp->t_state == TCPS_SYN_RECEIVED && (thflags & TH_ACK) &&
(SEQ_GT(tp->snd_una, th->th_ack) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
*ret_val = 1;
rack_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return;
} else
*ret_val = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack->r_wanted_output++;
tp->t_flags |= TF_ACKNOW;
if (m)
m_freem(m);
}
static int
rack_process_rst(struct mbuf *m, struct tcphdr *th, struct socket *so, struct tcpcb *tp)
{
/*
* RFC5961 Section 3.2
*
* - RST drops connection only if SEG.SEQ == RCV.NXT. - If RST is in
* window, we send challenge ACK.
*
* Note: to take into account delayed ACKs, we should test against
* last_ack_sent instead of rcv_nxt. Note 2: we handle special case
* of closed window, not covered by the RFC.
*/
int dropped = 0;
if ((SEQ_GEQ(th->th_seq, (tp->last_ack_sent - 1)) &&
SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
(tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) {
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
KASSERT(tp->t_state != TCPS_SYN_SENT,
("%s: TH_RST for TCPS_SYN_SENT th %p tp %p",
__func__, th, tp));
if (V_tcp_insecure_rst ||
(tp->last_ack_sent == th->th_seq) ||
(tp->rcv_nxt == th->th_seq) ||
((tp->last_ack_sent - 1) == th->th_seq)) {
TCPSTAT_INC(tcps_drops);
/* Drop the connection. */
switch (tp->t_state) {
case TCPS_SYN_RECEIVED:
so->so_error = ECONNREFUSED;
goto close;
case TCPS_ESTABLISHED:
case TCPS_FIN_WAIT_1:
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
case TCPS_CLOSING:
case TCPS_LAST_ACK:
so->so_error = ECONNRESET;
close:
tcp_state_change(tp, TCPS_CLOSED);
/* FALLTHROUGH */
default:
tp = tcp_close(tp);
}
dropped = 1;
rack_do_drop(m, tp);
} else {
TCPSTAT_INC(tcps_badrst);
/* Send challenge ACK. */
tcp_respond(tp, mtod(m, void *), th, m,
tp->rcv_nxt, tp->snd_nxt, TH_ACK);
tp->last_ack_sent = tp->rcv_nxt;
}
} else {
m_freem(m);
}
return (dropped);
}
/*
* The value in ret_val informs the caller
* if we dropped the tcb (and lock) or not.
* 1 = we dropped it, 0 = the TCB is still locked
* and valid.
*/
static void
rack_challenge_ack(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t * ret_val)
{
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
TCPSTAT_INC(tcps_badsyn);
if (V_tcp_insecure_syn &&
SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) {
tp = tcp_drop(tp, ECONNRESET);
*ret_val = 1;
rack_do_drop(m, tp);
} else {
/* Send challenge ACK. */
tcp_respond(tp, mtod(m, void *), th, m, tp->rcv_nxt,
tp->snd_nxt, TH_ACK);
tp->last_ack_sent = tp->rcv_nxt;
m = NULL;
*ret_val = 0;
rack_do_drop(m, NULL);
}
}
/*
* rack_ts_check returns 1 for you should not proceed. It places
* in ret_val what should be returned 1/0 by the caller. The 1 indicates
* that the TCB is unlocked and probably dropped. The 0 indicates the
* TCB is still valid and locked.
*/
static int
rack_ts_check(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t tlen, int32_t thflags, int32_t * ret_val)
{
/* Check to see if ts_recent is over 24 days old. */
if (tcp_ts_getticks() - tp->ts_recent_age > TCP_PAWS_IDLE) {
/*
* Invalidate ts_recent. If this segment updates ts_recent,
* the age will be reset later and ts_recent will get a
* valid value. If it does not, setting ts_recent to zero
* will at least satisfy the requirement that zero be placed
* in the timestamp echo reply when ts_recent isn't valid.
* The age isn't reset until we get a valid ts_recent
* because we don't want out-of-order segments to be dropped
* when ts_recent is old.
*/
tp->ts_recent = 0;
} else {
TCPSTAT_INC(tcps_rcvduppack);
TCPSTAT_ADD(tcps_rcvdupbyte, tlen);
TCPSTAT_INC(tcps_pawsdrop);
*ret_val = 0;
if (tlen) {
rack_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
} else {
rack_do_drop(m, NULL);
}
return (1);
}
return (0);
}
/*
* rack_drop_checks returns 1 for you should not proceed. It places
* in ret_val what should be returned 1/0 by the caller. The 1 indicates
* that the TCB is unlocked and probably dropped. The 0 indicates the
* TCB is still valid and locked.
*/
static int
rack_drop_checks(struct tcpopt *to, struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t * tlenp, int32_t * thf, int32_t * drop_hdrlen, int32_t * ret_val)
{
int32_t todrop;
int32_t thflags;
int32_t tlen;
thflags = *thf;
tlen = *tlenp;
todrop = tp->rcv_nxt - th->th_seq;
if (todrop > 0) {
if (thflags & TH_SYN) {
thflags &= ~TH_SYN;
th->th_seq++;
if (th->th_urp > 1)
th->th_urp--;
else
thflags &= ~TH_URG;
todrop--;
}
/*
* Following if statement from Stevens, vol. 2, p. 960.
*/
if (todrop > tlen
|| (todrop == tlen && (thflags & TH_FIN) == 0)) {
/*
* Any valid FIN must be to the left of the window.
* At this point the FIN must be a duplicate or out
* of sequence; drop it.
*/
thflags &= ~TH_FIN;
/*
* Send an ACK to resynchronize and drop any data.
* But keep on processing for RST or ACK.
*/
tp->t_flags |= TF_ACKNOW;
todrop = tlen;
TCPSTAT_INC(tcps_rcvduppack);
TCPSTAT_ADD(tcps_rcvdupbyte, todrop);
} else {
TCPSTAT_INC(tcps_rcvpartduppack);
TCPSTAT_ADD(tcps_rcvpartdupbyte, todrop);
}
*drop_hdrlen += todrop; /* drop from the top afterwards */
th->th_seq += todrop;
tlen -= todrop;
if (th->th_urp > todrop)
th->th_urp -= todrop;
else {
thflags &= ~TH_URG;
th->th_urp = 0;
}
}
/*
* If segment ends after window, drop trailing data (and PUSH and
* FIN); if nothing left, just ACK.
*/
todrop = (th->th_seq + tlen) - (tp->rcv_nxt + tp->rcv_wnd);
if (todrop > 0) {
TCPSTAT_INC(tcps_rcvpackafterwin);
if (todrop >= tlen) {
TCPSTAT_ADD(tcps_rcvbyteafterwin, tlen);
/*
* If window is closed can only take segments at
* window edge, and have to drop data and PUSH from
* incoming segments. Continue processing, but
* remember to ack. Otherwise, drop segment and
* ack.
*/
if (tp->rcv_wnd == 0 && th->th_seq == tp->rcv_nxt) {
tp->t_flags |= TF_ACKNOW;
TCPSTAT_INC(tcps_rcvwinprobe);
} else {
rack_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
return (1);
}
} else
TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
m_adj(m, -todrop);
tlen -= todrop;
thflags &= ~(TH_PUSH | TH_FIN);
}
*thf = thflags;
*tlenp = tlen;
return (0);
}
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;
TAILQ_FOREACH_REVERSE_FROM(prsm, &rack->r_ctl.rc_map, rack_head, r_next) {
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 maxseg;
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 */
maxseg = tcp_maxseg(tp);
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) <= maxseg) {
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 <= maxseg)) {
/*
* 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 <= maxseg) {
/*
* 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 <= maxseg) {
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 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_cur, srtt, thresh;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (TAILQ_EMPTY(&rack->r_ctl.rc_map)) {
return (NULL);
}
srtt_cur = tp->t_srtt >> TCP_RTT_SHIFT;
srtt = TICKS_2_MSEC(srtt_cur);
if (rack->rc_rack_rtt && (srtt > rack->rc_rack_rtt))
srtt = rack->rc_rack_rtt;
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;
thresh = rack_calc_thresh_rack(rack, srtt, tsused);
if (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 */
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],
tcp_persmin, tcp_persmax);
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)
{
/*
* 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;
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));
}
if (tp->t_state < TCPS_ESTABLISHED)
goto activate_rxt;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm == NULL) {
/* Nothing on the send map */
activate_rxt:
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 == 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;
}
}
/* Convert from ms to usecs */
if (rsm->r_flags & RACK_SACK_PASSED) {
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 (tp->t_srtt) {
srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT);
srtt = TICKS_2_MSEC(srtt_cur);
} else
srtt = RACK_INITIAL_RTO;
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;
}
} else {
to = rack->r_ctl.rc_min_to;
}
} else {
/* Ok we need to do a TLP not RACK */
if ((rack->rc_tlp_in_progress != 0) ||
(rack->r_ctl.rc_tlp_rtx_out != 0)) {
/*
* The previous send was a TLP or a tlp_rtx is in
* process.
*/
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;
if (TSTMP_GT(cts, rsm->r_tim_lastsent[idx]))
time_since_sent = cts - rsm->r_tim_lastsent[idx];
else
time_since_sent = 0;
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;
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;
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 (rsm->r_start != rack->r_ctl.rc_last_tlp_seq) {
/*
* The tail is no longer the last one I did a probe
* on
*/
rack->r_ctl.rc_tlp_seg_send_cnt = 0;
rack->r_ctl.rc_last_tlp_seq = rsm->r_start;
}
}
if (is_tlp_timer == 0) {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
} else {
if ((rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) ||
(rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) {
/*
* We have exceeded how many times we can retran the
* current TLP timer, switch to the RTO timer.
*/
goto activate_rxt;
} 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_SENTFIN) == 0) &&
(tp->snd_max - tp->snd_una) >= sbavail(&rack->rc_inp->inp_socket->so_snd))
/* Must need to send more data to enter persist */
return;
rack->r_ctl.rc_went_idle_time = cts;
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)
{
if (rack->rc_inp->inp_in_hpts) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack->r_ctl.rc_hpts_flags = 0;
}
rack->rc_in_persist = 0;
rack->r_ctl.rc_went_idle_time = 0;
tp->t_flags &= ~TF_FORCEDATA;
tp->t_rxtshift = 0;
}
static void
rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts, int32_t line,
int32_t slot, uint32_t tot_len_this_send, int32_t frm_out_sbavail)
{
struct inpcb *inp;
uint32_t delayed_ack = 0;
uint32_t hpts_timeout;
uint8_t stopped;
uint32_t left = 0;
inp = tp->t_inpcb;
if (inp->inp_in_hpts) {
/* A previous call is already set up */
return;
}
if (tp->t_state == TCPS_CLOSED) {
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;
if (rack->rc_inp->inp_in_hpts == 0) {
rack->r_ctl.rc_hpts_flags = 0;
}
if (slot) {
/* We are hptsi too */
rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
} else if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
/*
* We are still left on the hpts when the to goes
* it will be for output.
*/
if (TSTMP_GT(cts, rack->r_ctl.rc_last_output_to))
slot = cts - rack->r_ctl.rc_last_output_to;
else
slot = 1;
}
if ((tp->snd_wnd == 0) && TCPS_HAVEESTABLISHED(tp->t_state)) {
/* No send window.. we must enter persist */
rack_enter_persist(tp, rack, cts);
} else if ((frm_out_sbavail &&
(frm_out_sbavail > (tp->snd_max - tp->snd_una)) &&
(tp->snd_wnd < tp->t_maxseg)) &&
TCPS_HAVEESTABLISHED(tp->t_state)) {
/*
* If we have no window or we can't send a segment (and have
* data to send.. we cheat here and frm_out_sbavail is
* passed in with the sbavail(sb) only from bbr_output) and
* we are established, then we must enter persits (if not
* already in persits).
*/
rack_enter_persist(tp, rack, cts);
}
hpts_timeout = rack_timer_start(tp, rack, cts);
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 ((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 (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 (slot) {
rack->r_ctl.rc_last_output_to = cts + slot;
if ((hpts_timeout == 0) || (hpts_timeout > slot)) {
if (rack->rc_inp->inp_in_hpts == 0)
tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(slot));
rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
} else {
/*
* Arrange for the hpts to kick back in after the
* t-o if the t-o does not cause a send.
*/
if (rack->rc_inp->inp_in_hpts == 0)
tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout));
rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
}
} else if (hpts_timeout) {
if (rack->rc_inp->inp_in_hpts == 0)
tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout));
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, cts);
}
/*
* 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);
}
if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
/* Its not time yet */
return (0);
}
rack_log_to_event(rack, RACK_TO_FRM_RACK);
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);
rsm = rack_check_recovery_mode(tp, cts);
if (rsm) {
uint32_t rtt;
rtt = rack->rc_rack_rtt;
if (rtt == 0)
rtt = 1;
if ((recovery == 0) &&
(rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg)) {
/*
* 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 = tp->t_maxseg;
} else if ((rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg) &&
((rsm->r_end - rsm->r_start) > rack->r_ctl.rc_prr_sndcnt)) {
/*
* When a rack timer goes, we have to send at
* least one segment. They will be paced a min of 1ms
* apart via the next rack timer (or further
* if the rack timer dictates it).
*/
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
}
} else {
/* This is a case that should happen rarely if ever */
counter_u64_add(rack_tlp_does_nada, 1);
#ifdef TCP_BLACKBOX
tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
#endif
rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
return (0);
}
/*
* 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 socket *so;
uint32_t amm, old_prr_snd = 0;
uint32_t out, avail;
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 (rack_progress_timeout_check(tp)) {
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);
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;
avail = sbavail(&so->so_snd);
out = tp->snd_max - tp->snd_una;
rack->rc_timer_up = 1;
/*
* If we are in recovery we can jazz out a segment if new data is
* present simply by setting rc_prr_sndcnt to a segment.
*/
if ((avail > out) &&
((rack_always_send_oldest == 0) || (TAILQ_EMPTY(&rack->r_ctl.rc_tmap)))) {
/* New data is available */
amm = avail - out;
if (amm > tp->t_maxseg) {
amm = tp->t_maxseg;
} else if ((amm < tp->t_maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
/* not enough to fill a MTU and no-delay is off */
goto need_retran;
}
if (IN_RECOVERY(tp->t_flags)) {
/* Unlikely */
old_prr_snd = rack->r_ctl.rc_prr_sndcnt;
if (out + amm <= tp->snd_wnd)
rack->r_ctl.rc_prr_sndcnt = amm;
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_tlp_seg_send_cnt = 0;
rack->r_ctl.rc_last_tlp_seq = tp->snd_max;
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 (rack_always_send_oldest)
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
else {
rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
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;
}
if ((rsm->r_end - rsm->r_start) > tp->t_maxseg) {
/*
* We need to split this the last segment in two.
*/
int32_t idx;
struct rack_sendmap *nrsm;
nrsm = rack_alloc(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;
}
nrsm->r_start = (rsm->r_end - tp->t_maxseg);
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_sndcnt = rsm->r_sndcnt;
nrsm->r_rtr_bytes = 0;
rsm->r_end = nrsm->r_start;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
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;
rack->r_ctl.rc_tlp_rtx_out = 1;
if (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) {
rack->r_ctl.rc_tlp_seg_send_cnt++;
tp->t_rxtshift++;
} else {
rack->r_ctl.rc_last_tlp_seq = rsm->r_start;
rack->r_ctl.rc_tlp_seg_send_cnt = 1;
}
send:
rack->r_ctl.rc_tlp_send_cnt++;
if (rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) {
/*
* Can't [re]/transmit a segment we have not heard from the
* peer in max times. We need the retransmit timer to take
* over.
*/
restore:
rack->r_ctl.rc_tlpsend = NULL;
if (rsm)
rsm->r_flags &= ~RACK_TLP;
rack->r_ctl.rc_prr_sndcnt = old_prr_snd;
counter_u64_add(rack_tlp_retran_fail, 1);
goto out;
} else if (rsm) {
rsm->r_flags |= RACK_TLP;
}
if (rsm && (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) &&
(rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) {
/*
* We don't want to send a single segment more than the max
* either.
*/
goto restore;
}
rack->r_timer_override = 1;
rack->r_tlp_running = 1;
rack->rc_tlp_in_progress = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
return (0);
out:
rack->rc_timer_up = 0;
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);
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
TCPSTAT_INC(tcps_delack);
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
return (0);
}
/*
* Persists timer, here we simply need to setup the
* FORCE-DATA flag the output routine will send
* 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 inpcb *inp;
int32_t retval = 0;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (rack->rc_in_persist == 0)
return (0);
if (rack_progress_timeout_check(tp)) {
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.
*/
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)) {
TCPSTAT_INC(tcps_persistdrop);
retval = 1;
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);
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;
TCPSTAT_INC(tcps_persistdrop);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
goto out;
}
tp->t_flags |= TF_FORCEDATA;
out:
rack_log_to_event(rack, RACK_TO_FRM_PERSIST);
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);
/*
* Keep-alive timer went off; send something or drop connection if
* idle for too long.
*/
TCPSTAT_INC(tcps_keeptimeo);
if (tp->t_state < TCPS_ESTABLISHED)
goto dropit;
if ((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.
*/
TCPSTAT_INC(tcps_keepprobe);
t_template = tcpip_maketemplate(inp);
if (t_template) {
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, __LINE__, 0, 0, 0);
return (1);
dropit:
TCPSTAT_INC(tcps_keepdrops);
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);
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.
*/
TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
if (rsm->r_flags & RACK_ACKED) {
cnt++;
rsm->r_sndcnt = 0;
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;
}
}
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;
/* Clear the tlp rtx mark */
rack->r_ctl.rc_tlp_rtx_out = 0;
rack->r_ctl.rc_tlp_seg_send_cnt = 0;
rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_map);
/* Setup so we send one segment */
if (rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg)
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
rack->r_timer_override = 1;
}
/*
* 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;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (rack_progress_timeout_check(tp)) {
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.
*/
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
TCPSTAT_INC(tcps_timeoutdrop);
retval = 1;
tcp_set_inp_to_drop(rack->rc_inp,
(tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
goto out;
}
rack_remxt_tmr(tp);
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;
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.
*/
if (V_tcp_pmtud_blackhole_detect && (((tp->t_state == TCPS_ESTABLISHED))
|| (tp->t_state == TCPS_FIN_WAIT_1))) {
#ifdef INET6
int32_t isipv6;
#endif
/*
* 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
isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? 1 : 0;
if (isipv6 &&
tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
/* Use the sysctl tuneable blackhole MSS. */
tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
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;
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;
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;
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;
TCPSTAT_INC(tcps_pmtud_blackhole_failed);
}
}
}
/*
* Disable RFC1323 and SACK if we haven't got any response to our
* third SYN to work-around some broken terminal servers (most of
* which have hopefully been retired) that have bad VJ header
* compression code which trashes TCP segments containing
* unknown-to-them TCP options.
*/
if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
(tp->t_rxtshift == 3))
tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
/*
* 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;
}
if (rack_use_sack_filter)
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 (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) {
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);
rack->rc_last_pto_set = 0;
return (1);
}
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) {
ret = rack_timeout_rack(tp, rack, cts);
} else if (timers & PACE_TMR_TLP) {
ret = rack_timeout_tlp(tp, rack, cts);
} else if (timers & PACE_TMR_RXT) {
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)
{
uint8_t hpts_removed = 0;
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
hpts_removed = 1;
}
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_log_to_cancel(rack, hpts_removed, line);
rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
}
}
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++;
rsm->r_sndcnt++;
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) && (rack->r_tlp_running == 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);
}
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;
}
/* Update memory for next rtr */
rack->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
}
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;
uint32_t c_end;
int32_t len;
int32_t idx;
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(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.
*/
nrsm->r_start = c_end;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_sndcnt = rsm->r_sndcnt;
nrsm->r_rtr_bytes = 0;
rsm->r_end = c_end;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
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)
{
struct tcp_rack *rack;
struct rack_sendmap *rsm, *nrsm;
register uint32_t snd_max, snd_una;
int32_t idx;
/*
* 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;
len = end - seq_out;
}
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)
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? */
if (seq_out == snd_max) {
again:
rsm = rack_alloc(rack);
if (rsm == NULL) {
/*
* Hmm out of memory and the tcb got destroyed while
* we tried to wait.
*/
#ifdef INVARIANTS
panic("Out of memory when we should not be rack:%p", rack);
#endif
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;
if (th_flags & TH_SYN) {
/* The data space is one beyond snd_una */
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_sndcnt = 0;
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_map, rsm, r_next);
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
return;
}
/*
* If we reach here its a retransmission and we need to find it.
*/
more:
if (hintrsm && (hintrsm->r_start == seq_out)) {
rsm = hintrsm;
hintrsm = NULL;
} else if (rack->r_ctl.rc_next) {
/* We have a hint from a previous run */
rsm = rack->r_ctl.rc_next;
} else {
/* No hints sorry */
rsm = NULL;
}
if ((rsm) && (rsm->r_start == seq_out)) {
/*
* We used rc_next or hintrsm to retransmit, hopefully the
* likely case.
*/
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. */
TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
if (rsm->r_start == seq_out) {
seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
rack->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
if (len == 0) {
return;
} else {
continue;
}
}
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(rack);
if (nrsm == NULL) {
#ifdef INVARIANTS
panic("Ran out of memory that was preallocated? rack:%p", rack);
#endif
rack_update_rsm(tp, rack, rsm, ts);
return;
}
/*
* copy rsm to nrsm and then trim the front of rsm
* to not include this part.
*/
nrsm->r_start = seq_out;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_sndcnt = rsm->r_sndcnt;
nrsm->r_rtr_bytes = 0;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
rsm->r_end = nrsm->r_start;
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
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;
}
}
}
/*
* 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");
TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
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)
{
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;
}
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 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;
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;
}
TCPSTAT_INC(tcps_rttupdated);
rack_log_rtt_upd(tp, rack, rtt, o_srtt, o_var);
tp->t_rttupdated++;
#ifdef NETFLIX_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 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)
{
int32_t i;
uint32_t t;
if (rsm->r_flags & RACK_ACKED)
/* Already done */
return (0);
if ((rsm->r_rtr_cnt == 1) ||
((ack_type == CUM_ACKED) &&
(to->to_flags & TOF_TS) &&
(to->to_tsecr) &&
(rsm->r_tim_lastsent[rsm->r_rtr_cnt - 1] == to->to_tsecr))
) {
/*
* We will only find a matching timestamp if its cum-acked.
* But if its only one retransmission its for-sure matching
* :-)
*/
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;
}
}
tcp_rack_xmit_timer(rack, TCP_TS_TO_TICKS(t) + 1);
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.
*/
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
} else
rack->r_ctl.rc_tlp_rtx_out = 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_DEFERRED | 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;
}
}
/*
* Note the following calls to
* tcp_rack_xmit_timer() are being commented
* out for now. They give us no more accuracy
* and often lead to a wrong choice. We have
* enough samples that have not been
* retransmitted. I leave the commented out
* code in here in case in the future we
* decide to add it back (though I can't forsee
* doing that). That way we will easily see
* where they need to be placed.
*/
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);
}
}
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;
uint32_t ts;
int32_t idx;
idx = rsm->r_rtr_cnt - 1;
ts = rsm->r_tim_lastsent[idx];
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 */
continue;
}
idx = nrsm->r_rtr_cnt - 1;
if (ts == nrsm->r_tim_lastsent[idx]) {
/*
* For this case lets use seq no, if we sent in a
* big block (TSO) we would have a bunch of segments
* sent at the same time.
*
* We would only get a report if its SEQ is earlier.
* If we have done multiple retransmits the times
* would not be equal.
*/
if (SEQ_LT(nrsm->r_start, rsm->r_start)) {
nrsm->r_flags |= RACK_SACK_PASSED;
nrsm->r_flags &= ~RACK_WAS_SACKPASS;
}
} else {
/*
* Here they were sent at different times, not a big
* block. Since we transmitted this one later and
* see it sack'd then this must also be missing (or
* we would have gotten a sack block for it)
*/
nrsm->r_flags |= RACK_SACK_PASSED;
nrsm->r_flags &= ~RACK_WAS_SACKPASS;
}
}
}
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)
{
int32_t idx;
int32_t times = 0;
uint32_t start, end, changed = 0;
struct rack_sendmap *rsm, *nrsm;
int32_t used_ref = 1;
start = sack->start;
end = sack->end;
rsm = *prsm;
if (rsm && SEQ_LT(start, rsm->r_start)) {
TAILQ_FOREACH_REVERSE_FROM(rsm, &rack->r_ctl.rc_map, rack_head, r_next) {
if (SEQ_GEQ(start, rsm->r_start) &&
SEQ_LT(start, rsm->r_end)) {
goto do_rest_ofb;
}
}
}
if (rsm == NULL) {
start_at_beginning:
rsm = NULL;
used_ref = 0;
}
/* First lets locate the block where this guy is */
TAILQ_FOREACH_FROM(rsm, &rack->r_ctl.rc_map, r_next) {
if (SEQ_GEQ(start, rsm->r_start) &&
SEQ_LT(start, rsm->r_end)) {
break;
}
}
do_rest_ofb:
if (rsm == NULL) {
/*
* This happens when we get duplicate sack blocks with the
* same end. For example SACK 4: 100 SACK 3: 100 The sort
* will not change there location so we would just start at
* the end of the first one and get lost.
*/
if (tp->t_flags & TF_SENTFIN) {
/*
* Check to see if we have not logged the FIN that
* went out.
*/
nrsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
/*
* Ok we did not get the FIN logged.
*/
nrsm->r_end++;
rsm = nrsm;
goto do_rest_ofb;
}
}
if (times == 1) {
#ifdef INVARIANTS
panic("tp:%p rack:%p sack:%p to:%p prsm:%p",
tp, rack, sack, to, prsm);
#else
goto out;
#endif
}
times++;
counter_u64_add(rack_sack_proc_restart, 1);
goto start_at_beginning;
}
/* Ok we have an ACK for some piece of rsm */
if (rsm->r_start != start) {
/*
* Need to split this in two pieces the before and after.
*/
nrsm = rack_alloc(rack);
if (nrsm == NULL) {
/*
* failed XXXrrs what can we do but loose the sack
* info?
*/
goto out;
}
nrsm->r_start = start;
nrsm->r_rtr_bytes = 0;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_sndcnt = rsm->r_sndcnt;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
rsm->r_end = nrsm->r_start;
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
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;
}
if (SEQ_GEQ(end, rsm->r_end)) {
/*
* The end of this block is either beyond this guy or right
* at this guy.
*/
if ((rsm->r_flags & RACK_ACKED) == 0) {
rack_update_rtt(tp, rack, rsm, to, cts, SACKED);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
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;
}
}
if (end == rsm->r_end) {
/* This block only - done */
goto out;
}
/* There is more not coverend by this rsm move on */
start = rsm->r_end;
nrsm = TAILQ_NEXT(rsm, r_next);
rsm = nrsm;
times = 0;
goto do_rest_ofb;
}
/* Ok we need to split off this one at the tail */
nrsm = rack_alloc(rack);
if (nrsm == NULL) {
/* failed rrs what can we do but loose the sack info? */
goto out;
}
/* Clone it */
nrsm->r_start = end;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_bytes = 0;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_sndcnt = rsm->r_sndcnt;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
/* The sack block does not cover this guy fully */
rsm->r_flags &= (~RACK_HAS_FIN);
rsm->r_end = end;
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
if (rsm->r_flags & RACK_ACKED) {
/* Been here done that */
goto out;
}
rack_update_rtt(tp, rack, rsm, to, cts, SACKED);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
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;
}
out:
if (used_ref == 0) {
counter_u64_add(rack_sack_proc_all, 1);
} else {
counter_u64_add(rack_sack_proc_short, 1);
}
/* Save off where we last were */
if (rsm)
rack->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
else
rack->r_ctl.rc_sacklast = NULL;
*prsm = rsm;
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 = TAILQ_NEXT(rsm, r_next);
}
/*
* Now lets possibly clear the sack filter so we start
* recognizing sacks that cover this area.
*/
if (rack_use_sack_filter)
sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
}
static void
rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th)
{
uint32_t changed, last_seq, entered_recovery = 0;
struct tcp_rack *rack;
struct rack_sendmap *rsm;
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;
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 = TAILQ_FIRST(&rack->r_ctl.rc_map);
changed = 0;
th_ack = th->th_ack;
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++;
more:
rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
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);
/* Now do we consume the whole thing? */
if (SEQ_GEQ(th_ack, rsm->r_end)) {
/* Its all consumed. */
uint32_t left;
rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
TAILQ_REMOVE(&rack->r_ctl.rc_map, rsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
if (rack->r_ctl.rc_next == rsm) {
/* scoot along the marker */
rack->r_ctl.rc_next = TAILQ_FIRST(&rack->r_ctl.rc_map);
}
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);
} else if (rsm->r_flags & RACK_SACK_PASSED) {
/*
* There are acked segments ACKED on the
* scoreboard further up. We are seeing
* reordering.
*/
counter_u64_add(rack_reorder_seen, 1);
rsm->r_flags |= RACK_ACKED;
rack->r_ctl.rc_reorder_ts = cts;
}
left = th_ack - rsm->r_end;
if (rsm->r_rtr_cnt > 1) {
/*
* Technically we should make r_rtr_cnt be
* monotonicly increasing and just mod it to
* the timestamp it is replacing.. that way
* we would have the last 3 retransmits. Now
* rc_loss_count will be wrong if we
* retransmit something more than 2 times in
* recovery :(
*/
rack->r_ctl.rc_loss_count += (rsm->r_rtr_cnt - 1);
}
/* 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);
}
rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
rsm->r_start = th_ack;
}
proc_sack:
/* Check for reneging */
rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
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 to log */
goto out;
}
rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
if (rsm) {
last_seq = rsm->r_end;
} else {
last_seq = tp->snd_max;
}
/* 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)) {
if ((rack->r_ctl.rc_num_maps_alloced > rack_sack_block_limit) &&
(SEQ_LT(sack.end, last_seq)) &&
((sack.end - sack.start) < (tp->t_maxseg / 8))) {
/*
* Not the last piece and its smaller than
* 1/8th of a MSS. We ignore this.
*/
counter_u64_add(rack_runt_sacks, 1);
continue;
}
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
}
}
if (num_sack_blks == 0)
goto out;
/*
* Sort the SACK blocks so we can update the rack scoreboard with
* just one pass.
*/
if (rack_use_sack_filter) {
num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks, num_sack_blks, th->th_ack);
}
if (num_sack_blks < 2) {
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
* implememtations send these)?
*/
again:
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:
rsm = rack->r_ctl.rc_sacklast;
for (i = 0; i < num_sack_blks; i++) {
acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts);
if (acked) {
rack->r_wanted_output++;
changed += acked;
sack_changed += acked;
}
}
out:
if (changed) {
/* Something changed cancel the rack timer */
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
}
if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
/*
* Ok we have a high probability that we need to go in to
* recovery since we have data sack'd
*/
struct rack_sendmap *rsm;
uint32_t tsused;
tsused = tcp_ts_getticks();
rsm = tcp_rack_output(tp, rack, tsused);
if (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.
*/
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
rack->r_timer_override = 1;
}
}
if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
/* Deal with changed an 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;
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;
} 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 += tp->t_maxseg;
if (tp->snd_ssthresh > pipe) {
rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
} else {
rack->r_ctl.rc_prr_sndcnt = min(0, limit);
}
}
if (rack->r_ctl.rc_prr_sndcnt >= tp->t_maxseg) {
rack->r_timer_override = 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 recovery = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (SEQ_GT(th->th_ack, tp->snd_max)) {
rack_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
return (1);
}
if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
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);
TCPSTAT_ADD(tcps_rcvackpack, nsegs);
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 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 (th->th_ack == tp->snd_max) {
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
rack->r_wanted_output++;
}
/*
* If no data (only SYN) was ACK'd, skip rest of ACK processing.
*/
if (acked == 0) {
if (ofia)
*ofia = ourfinisacked;
return (0);
}
if (rack->r_ctl.rc_early_recovery) {
if (IN_FASTRECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover)) {
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)) {
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_FASTRECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover)) {
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 (tp->snd_una == tp->snd_max) {
/* Nothing left outstanding */
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
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++;
if (rack_use_sack_filter)
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;
tp = tcp_close(tp);
rack_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
return (1);
}
}
if (ofia)
*ofia = ourfinisacked;
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_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)
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++;
} 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;
}
}
/* Was persist timer active and now we have window space? */
if ((rack->rc_in_persist != 0) && tp->snd_wnd) {
rack_exit_persist(tp, rack);
tp->snd_nxt = tp->snd_max;
/* Make sure we output to start the timer */
rack->r_wanted_output++;
}
if (tp->t_flags2 & TF2_DROP_AF_DATA) {
m_freem(m);
return (0);
}
/*
* Process segments with URG.
*/
if ((thflags & TH_URG) && th->th_urp &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
/*
* This is a kludge, but if we receive and accept random
* urgent pointers, we'll crash in soreceive. It's hard to
* imagine someone actually wanting to send this much urgent
* data.
*/
SOCKBUF_LOCK(&so->so_rcv);
if (th->th_urp + sbavail(&so->so_rcv) > sb_max) {
th->th_urp = 0; /* XXX */
thflags &= ~TH_URG; /* XXX */
SOCKBUF_UNLOCK(&so->so_rcv); /* XXX */
goto dodata; /* XXX */
}
/*
* If this segment advances the known urgent pointer, then
* mark the data stream. This should not happen in
* CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since a
* FIN has been received from the remote side. In these
* states we ignore the URG.
*
* According to RFC961 (Assigned Protocols), the urgent
* pointer points to the last octet of urgent data. We
* continue, however, to consider it to indicate the first
* octet of data past the urgent section as the original
* spec states (in one of two places).
*/
if (SEQ_GT(th->th_seq + th->th_urp, tp->rcv_up)) {
tp->rcv_up = th->th_seq + th->th_urp;
so->so_oobmark = sbavail(&so->so_rcv) +
(tp->rcv_up - tp->rcv_nxt) - 1;
if (so->so_oobmark == 0)
so->so_rcv.sb_state |= SBS_RCVATMARK;
sohasoutofband(so);
tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA);
}
SOCKBUF_UNLOCK(&so->so_rcv);
/*
* Remove out of band data so doesn't get presented to user.
* This can happen independent of advancing the URG pointer,
* but if two URG's are pending at once, some out-of-band
* data may creep in... ick.
*/
if (th->th_urp <= (uint32_t) tlen &&
!(so->so_options & SO_OOBINLINE)) {
/* hdr drop is delayed */
tcp_pulloutofband(so, th, m, drop_hdrlen);
}
} else {
/*
* If no out of band data is expected, pull receive urgent
* pointer along with the receive window.
*/
if (SEQ_GT(tp->rcv_nxt, tp->rcv_up))
tp->rcv_up = tp->rcv_nxt;
}
dodata: /* XXX */
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) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tcp_seq save_start = th->th_seq;
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)) {
if (DELAY_ACK(tp, tlen) || tfo_syn) {
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
rack->r_wanted_output++;
tp->t_flags |= TF_ACKNOW;
}
tp->rcv_nxt += tlen;
thflags = th->th_flags & TH_FIN;
TCPSTAT_ADD(tcps_rcvpack, nsegs);
TCPSTAT_ADD(tcps_rcvbyte, tlen);
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(m);
else
sbappendstream_locked(&so->so_rcv, m, 0);
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
} 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.
*/
thflags = tcp_reass(tp, th, &save_start, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if (tlen > 0)
tcp_update_sack_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__);
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
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++;
}
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)
{
int32_t nsegs;
int32_t newsize = 0; /* automatic sockbuf scaling */
struct tcp_rack *rack;
#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);
/* Clean receiver SACK report if present */
if (tp->rcv_numsacks)
tcp_clean_sackreport(tp);
TCPSTAT_INC(tcps_preddat);
tp->rcv_nxt += tlen;
/*
* 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;
TCPSTAT_ADD(tcps_rcvpack, nsegs);
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 */
sbappendstream_locked(&so->so_rcv, m, 0);
rack_calc_rwin(so, tp);
}
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
if (DELAY_ACK(tp, tlen)) {
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
tp->t_flags |= TF_ACKNOW;
rack->r_wanted_output++;
}
if ((tp->snd_una == tp->snd_max) && rack_use_sack_filter)
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
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 */
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;
}
if ((rack->rc_in_persist != 0) && (tp->snd_wnd >= tp->t_maxseg)) {
rack_exit_persist(tp, rack);
}
/*
* 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.
*/
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
TCPSTAT_ADD(tcps_rcvackpack, nsegs);
TCPSTAT_ADD(tcps_rcvackbyte, acked);
sbdrop(&so->so_snd, acked);
/*
* 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;
/*
* 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 (tp->snd_una == tp->snd_max) {
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
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++;
}
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)
{
int32_t ret_val = 0;
int32_t todrop;
int32_t ourfinisacked = 0;
rack_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, beginning with URG
*/
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
rack_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);
rack_do_drop(m, tp);
return (1);
}
if (thflags & TH_RST) {
rack_do_drop(m, tp);
return (1);
}
if (!(thflags & TH_SYN)) {
rack_do_drop(m, tp);
return (1);
}
tp->irs = th->th_seq;
tcp_rcvseqinit(tp);
if (thflags & TH_ACK) {
int tfo_partial = 0;
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 == 0)) {
rack_timer_cancel(tp, (struct tcp_rack *)tp->t_fb_ptr,
((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++;
tp->t_flags |= TF_ACKNOW;
}
if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
V_tcp_do_ecn) {
tp->t_flags |= TF_ECN_PERMIT;
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);
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_INFO_RLOCK_ASSERT(&V_tcbinfo);
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;
TCPSTAT_INC(tcps_rcvpackafterwin);
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) {
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)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
rack_calc_rwin(so, tp);
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->snd_una) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
rack_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
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)) {
rack_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
} else if (thflags & TH_SYN) {
/* non-initial SYN is ignored */
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
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)) {
rack_do_drop(m, NULL);
return (0);
}
} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
rack_do_drop(m, NULL);
return (0);
}
}
if (thflags & TH_RST)
return (rack_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 (rack_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)) {
rack_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if (rack_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)) {
cc_conn_init(tp);
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
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;
/*
* Account for the ACK of our SYN prior to
* regular ACK processing below.
*/
tp->snd_una++;
}
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))
cc_conn_init(tp);
}
/*
* 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;
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)
{
int32_t ret_val = 0;
/*
* 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.
*/
if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
__predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
__predict_true(SEGQ_EMPTY(tp)) &&
__predict_true(th->th_seq == tp->rcv_nxt)) {
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
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)) {
return (0);
}
}
}
rack_calc_rwin(so, tp);
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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 (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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)
{
int32_t ret_val = 0;
rack_calc_rwin(so, tp);
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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 (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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;
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_allow_data_af_clo == 0) {
close_now:
tp = tcp_close(tp);
TCPSTAT_INC(tcps_rcvafterclose);
rack_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 */
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)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
rack_calc_rwin(so, tp);
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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 (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
rack_calc_rwin(so, tp);
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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) {
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tcp_twstart(tp);
m_freem(m);
return (1);
}
if (sbavail(&so->so_snd)) {
if (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
rack_calc_rwin(so, tp);
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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) {
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
tp = tcp_close(tp);
rack_do_drop(m, tp);
return (1);
}
if (sbavail(&so->so_snd)) {
if (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
rack_calc_rwin(so, tp);
/* Reset receive buffer auto scaling when not in bulk receive mode. */
if (thflags & TH_RST)
return (rack_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
rack_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 (rack_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (rack_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) {
rack_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
return (ret_val);
} else {
rack_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 (rack_progress_timeout_check(tp)) {
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
rack_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 int
rack_init(struct tcpcb *tp)
{
struct tcp_rack *rack = NULL;
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;
TAILQ_INIT(&rack->r_ctl.rc_map);
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_cpu = 0;
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;
rack->rc_pace_reduce = rack_slot_reduction;
if (V_tcp_delack_enabled)
tp->t_delayed_ack = 1;
else
tp->t_delayed_ack = 0;
rack->rc_pace_max_segs = rack_hptsi_segments;
rack->r_ctl.rc_early_recovery_segs = rack_early_recovery_max_seg;
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_idle_reduce_largest = rack_reduce_largest_on_idle;
rack->r_enforce_min_pace = rack_min_pace_time;
rack->r_min_pace_seg_thresh = rack_min_pace_time_seg_req;
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->rc_always_pace = rack_pace_every_seg;
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;
rack->r_ctl.rc_prr_inc_var = rack_inc_var;
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
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] = tcp_ts_getticks();
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->r_start = tp->snd_una;
rsm->r_end = tp->snd_max;
rsm->r_sndcnt = 0;
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_map, rsm, r_next);
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
}
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) {
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;
rack = (struct tcp_rack *)tp->t_fb_ptr;
#ifdef TCP_BLACKBOX
tcp_log_flowend(tp);
#endif
rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
while (rsm) {
TAILQ_REMOVE(&rack->r_ctl.rc_map, rsm, r_next);
uma_zfree(rack_zone, rsm);
rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
}
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
while (rsm) {
TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_next);
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;
}
}
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->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:
#ifdef INVARIANTS
panic("tcp tp:%p state:%d sees impossible state?", tp, tp->t_state);
#endif
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 (((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 (rsm && (rsm->r_flags & RACK_SACK_PASSED)) {
if ((tp->t_flags & TF_SENTFIN) &&
((tp->snd_max - tp->snd_una) == 1) &&
(rsm->r_flags & RACK_HAS_FIN)) {
/* needs to be a RXT */
if (tmr_up == PACE_TMR_RXT)
return;
} else if (tmr_up == PACE_TMR_RACK)
return;
} else if (SEQ_GT(tp->snd_max,tp->snd_una) &&
((tmr_up == PACE_TMR_TLP) ||
(tmr_up == PACE_TMR_RXT))) {
/*
* Either a TLP or RXT is fine if no sack-passed
* is in place and data is outstanding.
*/
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.
*/
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
}
static void
rack_hpts_do_segment(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 tcpopt to;
struct tcp_rack *rack;
struct rack_sendmap *rsm;
int32_t prev_state = 0;
cts = tcp_tv_to_mssectick(tv);
rack = (struct tcp_rack *)tp->t_fb_ptr;
kern_prefetch(rack, &prev_state);
prev_state = 0;
thflags = th->th_flags;
/*
* If this is either a state-changing packet or current state isn't
* established, we require a read lock on tcbinfo. Otherwise, we
* allow the tcbinfo to be in either locked or unlocked, as the
* caller may have unnecessarily acquired a lock due to a race.
*/
if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
tp->t_state != TCPS_ESTABLISHED) {
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
}
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__));
{
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;
TCP_LOG_EVENT(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
tlen, &log, true);
}
if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
way_out = 4;
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))) {
rack_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return;
}
/*
* 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)) {
#ifdef NETFLIX_CWV
if ((tp->cwv_enabled) &&
((tp->cwv_cwnd_valid == 0) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_cwnd > tp->snd_cwv.init_cwnd))) {
tcp_newcwv_nvp_closedown(tp);
} else
#endif
if ((ticks - tp->t_rcvtime) >= tp->t_rxtcur) {
counter_u64_add(rack_input_idle_reduces, 1);
rack_cc_after_idle(tp,
(rack->r_idle_reduce_largest ? 1 :0));
}
}
rack->r_ctl.rc_rcvtime = cts;
tp->t_rcvtime = ticks;
#ifdef NETFLIX_CWV
if (tp->cwv_enabled) {
if ((tp->cwv_cwnd_valid == 0) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_cwnd > tp->snd_cwv.init_cwnd))
tcp_newcwv_nvp_closedown(tp);
}
#endif
/*
* 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 NETFLIX_STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
#endif
/*
* 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_flags & TF_ECN_PERMIT) {
if (thflags & TH_CWR)
tp->t_flags &= ~TF_ECN_SND_ECE;
switch (iptos & IPTOS_ECN_MASK) {
case IPTOS_ECN_CE:
tp->t_flags |= TF_ECN_SND_ECE;
TCPSTAT_INC(tcps_ecn_ce);
break;
case IPTOS_ECN_ECT0:
TCPSTAT_INC(tcps_ecn_ect0);
break;
case IPTOS_ECN_ECT1:
TCPSTAT_INC(tcps_ecn_ect1);
break;
}
/* 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.
*/
rack->r_cpu = inp_to_cpuid(tp->t_inpcb);
if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
if ((to.to_flags & TOF_SCALE) &&
(tp->t_flags & TF_REQ_SCALE)) {
tp->t_flags |= TF_RCVD_SCALE;
tp->snd_scale = to.to_wscale;
}
/*
* 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_RCVD_TSTMP;
tp->ts_recent = to.to_tsval;
tp->ts_recent_age = cts;
}
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, if not rack is *not* possible and
* we switch to the default code.
*/
if ((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;
}
/* Set the flag */
rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
tcp_set_hpts(tp->t_inpcb);
rack_stop_all_timers(tp);
sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
}
/*
* 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).
*/
if (rack->r_state != tp->t_state)
rack_set_state(tp, rack);
if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&rack->r_ctl.rc_map)) != NULL)
kern_prefetch(rsm, &prev_state);
prev_state = rack->r_state;
rack->r_ctl.rc_tlp_send_cnt = 0;
rack_clear_rate_sample(rack);
retval = (*rack->r_substate) (m, th, so,
tp, &to, drop_hdrlen,
tlen, tiwin, thflags, nxt_pkt);
#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);
tcp_rack_xmit_timer_commit(rack, tp);
if (((tp->snd_max - tp->snd_una) > tp->snd_wnd) &&
(rack->rc_in_persist == 0)){
/*
* The peer shrunk its window on us to the point
* where we have sent too much. The only thing
* we can do here is stop any timers and
* enter persist. We most likely lost the last
* bytes we sent but oh well, we will have to
* retransmit them after the peer is caught up.
*/
if (rack->rc_inp->inp_in_hpts)
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack_timer_cancel(tp, rack, cts, __LINE__);
rack_enter_persist(tp, rack, cts);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
way_out = 3;
goto done_with_input;
}
if (nxt_pkt == 0) {
if (rack->r_wanted_output != 0) {
did_out = 1;
(void)tp->t_fb->tfb_tcp_output(tp);
}
rack_start_hpts_timer(rack, tp, cts, __LINE__, 0, 0, 0);
}
if (((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
(SEQ_GT(tp->snd_max, tp->snd_una) ||
(tp->t_flags & TF_DELACK) ||
((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->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/* keep alive not needed if we are hptsi output yet */
;
} else {
if (rack->rc_inp->inp_in_hpts)
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
}
way_out = 1;
} else {
/* 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
INP_WUNLOCK(tp->t_inpcb);
}
}
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;
#ifdef RSS
struct tcp_function_block *tfb;
struct tcp_rack *rack;
struct epoch_tracker et;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->r_state == 0) {
/*
* Initial input (ACK to SYN-ACK etc)lets go ahead and get
* it processed
*/
INP_INFO_RLOCK_ET(&V_tcbinfo, et);
tcp_get_usecs(&tv);
rack_hpts_do_segment(m, th, so, tp, drop_hdrlen,
tlen, iptos, 0, &tv);
INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
return;
}
tcp_queue_to_input(tp, m, th, tlen, drop_hdrlen, iptos);
INP_WUNLOCK(tp->t_inpcb);
#else
tcp_get_usecs(&tv);
rack_hpts_do_segment(m, th, so, tp, drop_hdrlen,
tlen, iptos, 0, &tv);
#endif
}
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_cur, srtt = 0, thresh = 0, ts_low = 0;
/* Return the next guy to be re-transmitted */
if (TAILQ_EMPTY(&rack->r_ctl.rc_map)) {
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:
srtt_cur = tp->t_srtt >> TCP_RTT_SHIFT;
srtt = TICKS_2_MSEC(srtt_cur);
if (rack->rc_rack_rtt && (srtt > rack->rc_rack_rtt))
srtt = rack->rc_rack_rtt;
if (rsm->r_flags & RACK_ACKED) {
return (NULL);
}
if ((rsm->r_flags & RACK_SACK_PASSED) == 0) {
/* Its not yet ready */
return (NULL);
}
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) {
return (NULL);
}
if ((tsused - ts_low) >= thresh) {
return (rsm);
}
return (NULL);
}
static int
rack_output(struct tcpcb *tp)
{
struct socket *so;
uint32_t recwin, sendwin;
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;
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 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, would_have_fin = 0;
struct tcpopt to;
int32_t slot = 0;
uint32_t cts;
uint8_t hpts_calling, doing_tlp = 0;
int32_t do_a_prefetch;
int32_t prefetch_rsm = 0;
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
/* 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;
INP_WLOCK_ASSERT(inp);
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
return (tcp_offload_output(tp));
#endif
#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
cts = tcp_ts_getticks();
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__);
}
/* Mark that we have called rack_output(). */
if ((rack->r_timer_override) ||
(tp->t_flags & TF_FORCEDATA) ||
(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);
}
hpts_calling = inp->inp_hpts_calls;
inp->inp_hpts_calls = 0;
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);
}
}
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 */
return (0);
/*
* 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);
#ifdef NETFLIX_CWV
if (tp->cwv_enabled) {
if ((tp->cwv_cwnd_valid == 0) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_cwnd > tp->snd_cwv.init_cwnd))
tcp_newcwv_nvp_closedown(tp);
} else
#endif
if (tp->t_idle_reduce) {
if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
rack_cc_after_idle(tp,
(rack->r_idle_reduce_largest ? 1 :0));
}
tp->t_flags &= ~TF_LASTIDLE;
if (idle) {
if (tp->t_flags & TF_MORETOCOME) {
tp->t_flags |= TF_LASTIDLE;
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;
cts = tcp_ts_getticks();
tso = 0;
mtu = 0;
sb_offset = tp->snd_max - tp->snd_una;
sendwin = min(tp->snd_wnd, tp->snd_cwnd);
flags = tcp_outflags[tp->t_state];
/*
* Send any SACK-generated retransmissions. If we're explicitly
* trying to send out new data (when sendalot is 1), bypass this
* function. If we retransmit in fast recovery mode, decrement
* snd_cwnd, since we're replacing a (future) new transmission with
* a retransmission now, and we previously incremented snd_cwnd in
* tcp_input().
*/
/*
* Still in sack recovery , reset rxmit flag to zero.
*/
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;
goto just_return_nolock;
}
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_next);
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_tlpsend) {
/* Tail loss probe */
long cwin;
long tlen;
doing_tlp = 1;
rsm = rack->r_ctl.rc_tlpsend;
rack->r_ctl.rc_tlpsend = NULL;
sack_rxmit = 1;
tlen = rsm->r_end - rsm->r_start;
if (tlen > tp->t_maxseg)
tlen = tp->t_maxseg;
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;
} else if (rack->r_ctl.rc_resend) {
/* Retransmit timer */
rsm = rack->r_ctl.rc_resend;
rack->r_ctl.rc_resend = NULL;
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 >= tp->t_maxseg) {
len = tp->t_maxseg;
}
} else if ((rack->rc_in_persist == 0) &&
((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) {
long tlen;
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.
*/
rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
}
#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
tlen = 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;
if (tlen > rack->r_ctl.rc_prr_sndcnt) {
len = rack->r_ctl.rc_prr_sndcnt;
} else {
len = tlen;
}
if (len >= tp->t_maxseg) {
sendalot = 1;
len = tp->t_maxseg;
} else {
sendalot = 0;
if ((rack->rc_timer_up == 0) &&
(len < tlen)) {
/*
* If its not a timer don't send a partial
* segment.
*/
len = 0;
goto just_return_nolock;
}
}
if (len > 0) {
sub_from_prr = 1;
sack_rxmit = 1;
TCPSTAT_INC(tcps_sack_rexmits);
TCPSTAT_ADD(tcps_sack_rexmit_bytes,
min(len, tp->t_maxseg));
counter_u64_add(rack_rtm_prr_retran, 1);
}
}
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 in persist timeout with window of 0, send 1 byte. Otherwise,
* if window is small but nonzero and time TF_SENTFIN expired, we
* will send what we can and go to transmit state.
*/
if (tp->t_flags & TF_FORCEDATA) {
if (sendwin == 0) {
/*
* If we still have some data to send, then clear
* the FIN bit. Usually this would happen below
* when it realizes that we aren't sending all the
* data. However, if we have exactly 1 byte of
* unsent data, then it won't clear the FIN bit
* below, and if we are in persist state, we wind up
* sending the packet without recording that we sent
* the FIN bit.
*
* We can't just blindly clear the FIN bit, because
* if we don't have any more data to send then the
* probe will be the FIN itself.
*/
if (sb_offset < sbused(sb))
flags &= ~TH_FIN;
sendwin = 1;
} else {
if (rack->rc_in_persist)
rack_exit_persist(tp, rack);
/*
* If we are dropping persist mode then we need to
* correct snd_nxt/snd_max and off.
*/
tp->snd_nxt = tp->snd_max;
sb_offset = tp->snd_nxt - tp->snd_una;
}
}
/*
* 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) {
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) {
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;
doing_tlp = 1;
} else {
if (sendwin > avail) {
/* use the available */
if (avail > sb_offset) {
len = (int32_t)(avail - sb_offset);
} else {
len = 0;
}
} else {
if (sendwin > sb_offset) {
len = (int32_t)(sendwin - sb_offset);
} else {
len = 0;
}
}
}
} 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)
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 > tp->t_maxseg) {
/*
* 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 = tp->t_maxseg;
} else if (len < tp->t_maxseg) {
/*
* 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;
}
}
}
}
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))) {
if (tp->t_state != TCPS_SYN_RECEIVED)
flags &= ~TH_SYN;
/*
* 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;
sb_offset--, len++;
}
/*
* 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)))
len = 0;
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)) &&
(sb_offset < (int)sbavail(sb))) {
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, cts);
}
}
/* len will be >= 0 after this point. */
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
tcp_sndbuf_autoscale(tp, so, sendwin);
/*
* 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 > tp->t_maxseg &&
(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 (outstanding > 0) {
/*
* This is sub-optimal. We only send a stand alone
* FIN on its own segment.
*/
if (flags & TH_FIN) {
flags &= ~TH_FIN;
would_have_fin = 1;
}
} else 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 = sbspace(&so->so_rcv);
/*
* 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 >= tp->t_maxseg) {
pass = 1;
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(&so->so_snd)) &&
(tp->t_flags & TF_NOPUSH) == 0) {
pass = 2;
goto send;
}
if (tp->t_flags & TF_FORCEDATA) { /* typ. timeout case */
pass = 3;
goto send;
}
if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
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;
}
}
/*
* 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 = min(recwin, (long)TCP_MAXWIN << tp->rcv_scale);
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
oldwin = (tp->rcv_adv - tp->rcv_nxt);
adv -= oldwin;
} else
oldwin = 0;
/*
* If the new window size ends up being the same as 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 * tp->t_maxseg) &&
(adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
so->so_rcv.sb_hiwat <= 8 * tp->t_maxseg)) {
pass = 7;
goto send;
}
if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
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 (SEQ_GT(tp->snd_up, tp->snd_una)) {
pass = 10;
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:
if (tot_len_this_send == 0)
counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, tot_len_this_send, 1);
rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling);
tp->t_flags &= ~TF_FORCEDATA;
return (0);
send:
if (doing_tlp == 0) {
/*
* Data not a TLP, and its not the rxt firing. If it is the
* rxt firing, we want to leave the tlp_in_progress flag on
* so we don't send another TLP. It has to be a rack timer
* or normal send (response to acked data) to clear the tlp
* in progress flag.
*/
rack->rc_tlp_in_progress = 0;
}
SOCKBUF_LOCK_ASSERT(sb);
if (len > 0) {
if (len >= tp->t_maxseg)
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
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#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 (flags & TH_FIN) {
would_have_fin = 1;
flags &= ~TH_FIN;
}
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;
}
}
/*
* 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)) {
moff = len % (u_int)max_len;
if (moff != 0) {
len -= moff;
sendalot = 1;
}
}
/*
* In case there are too many small fragments don't
* use TSO:
*/
if (len <= max_len) {
len = max_len;
sendalot = 1;
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 = 1;
} else {
len = tp->t_maxseg - optlen - ipoptlen;
sendalot = 1;
}
} else
tso = 0;
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->rc_pace_max_segs)
max_val = rack->rc_pace_max_segs * tp->t_maxseg;
else
max_val = len;
/*
* We allow a limit on sending with hptsi.
*/
if (len > max_val) {
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) {
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);
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 ((tp->t_flags & TF_FORCEDATA) && len == 1) {
TCPSTAT_INC(tcps_sndprobe);
#ifdef NETFLIX_STATS
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
stats_voi_update_abs_u32(tp->t_stats,
VOI_TCP_RETXPB, len);
else
stats_voi_update_abs_u64(tp->t_stats,
VOI_TCP_TXPB, len);
#endif
} else 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++;
TCPSTAT_INC(tcps_sndrexmitpack);
TCPSTAT_ADD(tcps_sndrexmitbyte, len);
}
#ifdef NETFLIX_STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
len);
#endif
} else {
TCPSTAT_INC(tcps_sndpack);
TCPSTAT_ADD(tcps_sndbyte, len);
#ifdef NETFLIX_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;
/*
* Are we doing hptsi, if so we must calculate the slot. We
* only do hptsi in ESTABLISHED and with no RESET being
* sent where we have data to send.
*/
if (((tp->t_state == TCPS_ESTABLISHED) ||
(tp->t_state == TCPS_CLOSE_WAIT) ||
((tp->t_state == TCPS_FIN_WAIT_1) &&
((tp->t_flags & TF_SENTFIN) == 0) &&
((flags & TH_FIN) == 0))) &&
((flags & TH_RST) == 0) &&
(rack->rc_always_pace)) {
/*
* 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;
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 = tp->snd_cwnd;
tr_perms = cwnd / srtt;
if (tr_perms == 0) {
tr_perms = tp->t_maxseg;
}
tot_len_this_send += len;
/*
* 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 = tot_len_this_send / tr_perms;
/* Now do we reduce the time so we don't run dry? */
if (slot && rack->rc_pace_reduce) {
int32_t reduce;
reduce = (slot / rack->rc_pace_reduce);
if (reduce < slot) {
slot -= reduce;
} else
slot = 0;
}
if (rack->r_enforce_min_pace &&
(slot == 0) &&
(tot_len_this_send >= (rack->r_min_pace_seg_thresh * tp->t_maxseg))) {
/* We are enforcing a minimum pace time of 1ms */
slot = rack->r_enforce_min_pace;
}
}
SOCKBUF_UNLOCK(sb);
} else {
SOCKBUF_UNLOCK(sb);
if (tp->t_flags & TF_ACKNOW)
TCPSTAT_INC(tcps_sndacks);
else if (flags & (TH_SYN | TH_FIN | TH_RST))
TCPSTAT_INC(tcps_sndctrl);
else if (SEQ_GT(tp->snd_up, tp->snd_una))
TCPSTAT_INC(tcps_sndurg);
else
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, 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, 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;
}
if (tp->t_state == TCPS_ESTABLISHED &&
(tp->t_flags & TF_ECN_PERMIT)) {
/*
* If the peer has ECN, mark data packets with ECN capable
* transmission (ECT). Ignore pure ack packets,
* retransmissions and window probes.
*/
if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
!((tp->t_flags & TF_FORCEDATA) && len == 1)) {
#ifdef INET6
if (isipv6)
ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
else
#endif
ip->ip_tos |= IPTOS_ECN_ECT0;
TCPSTAT_INC(tcps_ecn_ect0);
}
/*
* Reply with proper ECN notifications.
*/
if (tp->t_flags & TF_ECN_SND_CWR) {
flags |= TH_CWR;
tp->t_flags &= ~TF_ECN_SND_CWR;
}
if (tp->t_flags & TF_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)tp->t_maxseg)
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);
if (recwin > (long)TCP_MAXWIN << tp->rcv_scale)
recwin = (long)TCP_MAXWIN << tp->rcv_scale;
}
/*
* 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
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;
if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
th->th_flags |= TH_URG;
} else
/*
* If no urgent pointer to send, then we pull the urgent
* pointer to the left edge of the send window so that it
* doesn't drift into the send window on sequence number
* wraparound.
*/
tp->snd_up = tp->snd_una; /* drag it along */
#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);
} 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);
} 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) {
KASSERT(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;
}
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
KASSERT(len + hdrlen + ipoptlen - ipsec_optlen == m_length(m, NULL),
("%s: mbuf chain shorter than expected: %d + %u + %u - %u != %u",
__func__, len, hdrlen, ipoptlen, ipsec_optlen, m_length(m, NULL)));
#else
KASSERT(len + hdrlen + ipoptlen == m_length(m, NULL),
("%s: mbuf chain shorter than expected: %d + %u + %u != %u",
__func__, len, hdrlen, ipoptlen, m_length(m, NULL)));
#endif
#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;
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 = rack->r_ctl.rc_prr_sndcnt;
if (rsm || sack_rxmit) {
log.u_bbr.flex8 = 1;
} else {
log.u_bbr.flex8 = 0;
}
lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
len, &log, false, NULL, NULL, 0, NULL);
} 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, tp->t_inpcb->in6p_outputopts,
&inp->inp_route6,
((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0),
NULL, NULL, inp);
if (error == EMSGSIZE && inp->inp_route6.ro_rt != NULL)
mtu = inp->inp_route6.ro_rt->rt_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, tp->t_inpcb->inp_options, &inp->inp_route,
((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 0,
inp);
if (error == EMSGSIZE && inp->inp_route.ro_rt != NULL)
mtu = inp->inp_route.ro_rt->rt_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) {
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 / tp->t_maxseg) + 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 (sub_from_prr && (error == 0)) {
rack->r_ctl.rc_prr_sndcnt -= len;
}
sub_from_prr = 0;
rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts,
pass, rsm);
if ((tp->t_flags & TF_FORCEDATA) == 0 ||
(rack->rc_in_persist == 0)) {
tcp_seq startseq = tp->snd_nxt;
/*
* Advance snd_nxt over sequence space of this segment.
*/
if (error)
/* We don't log or do anything with errors */
goto timer;
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 timer;
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;
TCPSTAT_INC(tcps_segstimed);
}
#ifdef NETFLIX_STATS
if (!(tp->t_flags & TF_GPUTINPROG) && len) {
tp->t_flags |= TF_GPUTINPROG;
tp->gput_seq = startseq;
tp->gput_ack = startseq +
ulmin(sbavail(sb) - sb_offset, sendwin);
tp->gput_ts = tcp_ts_getticks();
}
#endif
}
/*
* Set retransmit timer if not currently set, and not doing
* a pure ack or a keep-alive probe. Initial value for
* retransmit timer is smoothed round-trip time + 2 *
* round-trip time variance. Initialize shift counter which
* is used for backoff of retransmit time.
*/
timer:
if ((tp->snd_wnd == 0) &&
TCPS_HAVEESTABLISHED(tp->t_state)) {
/*
* If the persists timer was set above (right before
* the goto send), and still needs to be on. Lets
* make sure all is canceled. If the persist timer
* is not running, we want to get it up.
*/
if (rack->rc_in_persist == 0) {
rack_enter_persist(tp, rack, cts);
}
}
} 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) {
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_flags &= ~TF_FORCEDATA;
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;
if (rack->rc_enobuf < 255)
rack->rc_enobuf++;
if (slot > (rack->rc_rack_rtt / 2)) {
slot = rack->rc_rack_rtt / 2;
}
if (slot < 10)
slot = 10;
}
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;
rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, 0, 1);
tp->t_flags &= ~TF_FORCEDATA;
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;
rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, 0, 1);
tp->t_flags &= ~TF_FORCEDATA;
return (error);
}
} else {
rack->rc_enobuf = 0;
}
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:
rack->r_tlp_running = 0;
if ((flags & TH_RST) || (would_have_fin == 1)) {
/*
* We don't send again after a RST. We also do *not* send
* again if we would have had a find, but now have
* outstanding data.
*/
slot = 0;
sendalot = 0;
}
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;
tp->t_flags &= ~TF_FORCEDATA;
goto again;
} else if (len) {
counter_u64_add(rack_unpaced_segments, 1);
}
tp->t_flags &= ~TF_FORCEDATA;
rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, tot_len_this_send, 1);
return (error);
}
/*
* 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)
{
int32_t error = 0, optval;
switch (sopt->sopt_name) {
case TCP_RACK_PROP_RATE:
case TCP_RACK_PROP:
case TCP_RACK_TLP_REDUCE:
case TCP_RACK_EARLY_RECOV:
case TCP_RACK_PACE_ALWAYS:
case TCP_DELACK:
case TCP_RACK_PACE_REDUCE:
case TCP_RACK_PACE_MAX_SEG:
case TCP_RACK_PRR_SENDALOT:
case TCP_RACK_MIN_TO:
case TCP_RACK_EARLY_SEG:
case TCP_RACK_REORD_THRESH:
case TCP_RACK_REORD_FADE:
case TCP_RACK_TLP_THRESH:
case TCP_RACK_PKT_DELAY:
case TCP_RACK_TLP_USE:
case TCP_RACK_TLP_INC_VAR:
case TCP_RACK_IDLE_REDUCE_HIGH:
case TCP_RACK_MIN_PACE:
case TCP_RACK_MIN_PACE_SEG:
case TCP_BBR_RACK_RTT_USE:
case TCP_DATA_AFTER_CLOSE:
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_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;
case TCP_RACK_PACE_ALWAYS:
/* Use the always pace method (bool) */
RACK_OPTS_INC(tcp_rack_pace_always);
if (optval > 0)
rack->rc_always_pace = 1;
else
rack->rc_always_pace = 0;
break;
case TCP_RACK_PACE_REDUCE:
/* RACK Hptsi reduction factor (divisor) */
RACK_OPTS_INC(tcp_rack_pace_reduce);
if (optval)
/* Must be non-zero */
rack->rc_pace_reduce = optval;
else
error = EINVAL;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments in a pace */
RACK_OPTS_INC(tcp_rack_max_seg);
rack->rc_pace_max_segs = optval;
break;
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_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 */
RACK_OPTS_INC(tcp_rack_tlp_inc_var);
rack->r_ctl.rc_prr_inc_var = optval;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
RACK_OPTS_INC(tcp_rack_idle_reduce_high);
if (optval)
rack->r_idle_reduce_largest = 1;
else
rack->r_idle_reduce_largest = 0;
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;
rack_output(tp);
}
break;
case TCP_RACK_MIN_PACE:
RACK_OPTS_INC(tcp_rack_min_pace);
if (optval > 3)
rack->r_enforce_min_pace = 3;
else
rack->r_enforce_min_pace = optval;
break;
case TCP_RACK_MIN_PACE_SEG:
RACK_OPTS_INC(tcp_rack_min_pace_seg);
if (optval >= 16)
rack->r_min_pace_seg_thresh = 15;
else
rack->r_min_pace_seg_thresh = optval;
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;
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;
/*
* 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.
*/
switch (sopt->sopt_name) {
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) */
optval = rack->rc_pace_reduce;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments in a pace */
optval = rack->rc_pace_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_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 */
optval = rack->r_ctl.rc_prr_inc_var;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
optval = rack->r_idle_reduce_largest;
break;
case TCP_RACK_MIN_PACE:
optval = rack->r_enforce_min_pace;
break;
case TCP_RACK_MIN_PACE_SEG:
optval = rack->r_min_pace_seg_thresh;
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;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
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);
}
struct tcp_function_block __tcp_rack = {
.tfb_tcp_block_name = __XSTRING(STACKNAME),
.tfb_tcp_output = rack_output,
.tfb_tcp_do_segment = rack_do_segment,
.tfb_tcp_hpts_do_segment = rack_hpts_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
};
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,
__XSTRING(STACKNAME),
CTLFLAG_RW, 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);
}
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;
}
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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