d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
516dc824d9
freebsd-dev/sys/netinet/tcp_stacks/bbr.c
Michael Tuexen 12a43d0d5d RFC 7112 requires a host to put the complete IP header chain 
including the TCP header in the first IP packet.
Enforce this in tcp_output(). In addition make sure that at least
one byte payload fits in the TCP segement to allow making progress.
Without this check, a kernel with INVARIANTS will panic.
This issue was found by running an instance of syzkaller.

Reviewed by:		jtl@
MFC after:		3 days
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D21665
2019-09-29 10:45:13 +00:00

15194 lines
454 KiB
C
Raw Blame History

/*-
* Copyright (c) 2016-2019
* Netflix Inc.
* All rights reserved.
*
* 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.
*
*/
/**
* Author: Randall Stewart <rrs@netflix.com>
* This work is based on the ACM Queue paper
* BBR - Congestion Based Congestion Control
* and also numerous discussions with Neal, Yuchung and Van.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
#include "opt_ratelimit.h"
#include "opt_kern_tls.h"
#include <sys/param.h>
#include <sys/module.h>
#include <sys/kernel.h>
#ifdef TCP_HHOOK
#include <sys/hhook.h>
#endif
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#ifdef KERN_TLS
#include <sys/ktls.h>
#endif
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/qmath.h>
#include <sys/tree.h>
#ifdef NETFLIX_STATS
#include <sys/stats.h> /* Must come after qmath.h and tree.h */
#endif
#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/eventhandler.h>
#include <sys/smp.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/tim_filter.h>
#include <sys/time.h>
#include <vm/uma.h>
#include <sys/kern_prefetch.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>
#define TCPOUTFLAGS
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_hpts.h>
#include <netinet/cc/cc.h>
#include <netinet/tcp_log_buf.h>
#include <netinet/tcp_ratelimit.h>
#include <netinet/tcp_lro.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 <netinet/tcp_fastopen.h>
#include <netipsec/ipsec_support.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/ethernet.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_bbr.h"
#include "rack_bbr_common.h"
uma_zone_t bbr_zone;
uma_zone_t bbr_pcb_zone;
struct sysctl_ctx_list bbr_sysctl_ctx;
struct sysctl_oid *bbr_sysctl_root;
#define TCPT_RANGESET_NOSLOP(tv, value, tvmin, tvmax) do { \
(tv) = (value); \
if ((u_long)(tv) < (u_long)(tvmin)) \
(tv) = (tvmin); \
if ((u_long)(tv) > (u_long)(tvmax)) \
(tv) = (tvmax); \
} while(0)
/*#define BBR_INVARIANT 1*/
/*
* initial window
*/
static uint32_t bbr_def_init_win = 10;
static int32_t bbr_persist_min = 250000; /* 250ms */
static int32_t bbr_persist_max = 1000000; /* 1 Second */
static int32_t bbr_cwnd_may_shrink = 0;
static int32_t bbr_cwndtarget_rtt_touse = BBR_RTT_PROP;
static int32_t bbr_num_pktepo_for_del_limit = BBR_NUM_RTTS_FOR_DEL_LIMIT;
static int32_t bbr_hardware_pacing_limit = 8000;
static int32_t bbr_quanta = 3; /* How much extra quanta do we get? */
static int32_t bbr_no_retran = 0;
static int32_t bbr_tcp_map_entries_limit = 1500;
static int32_t bbr_tcp_map_split_limit = 256;
static int32_t bbr_error_base_paceout = 10000; /* usec to pace */
static int32_t bbr_max_net_error_cnt = 10;
/* Should the following be dynamic too -- loss wise */
static int32_t bbr_rtt_gain_thresh = 0;
/* Measurement controls */
static int32_t bbr_use_google_algo = 1;
static int32_t bbr_ts_limiting = 1;
static int32_t bbr_ts_can_raise = 0;
static int32_t bbr_do_red = 600;
static int32_t bbr_red_scale = 20000;
static int32_t bbr_red_mul = 1;
static int32_t bbr_red_div = 2;
static int32_t bbr_red_growth_restrict = 1;
static int32_t bbr_target_is_bbunit = 0;
static int32_t bbr_drop_limit = 0;
/*
* How much gain do we need to see to
* stay in startup?
*/
static int32_t bbr_marks_rxt_sack_passed = 0;
static int32_t bbr_start_exit = 25;
static int32_t bbr_low_start_exit = 25; /* When we are in reduced gain */
static int32_t bbr_startup_loss_thresh = 2000; /* 20.00% loss */
static int32_t bbr_hptsi_max_mul = 1; /* These two mul/div assure a min pacing */
static int32_t bbr_hptsi_max_div = 2; /* time, 0 means turned off. We need this
* if we go back ever to where the pacer
* has priority over timers.
*/
static int32_t bbr_policer_call_from_rack_to = 0;
static int32_t bbr_policer_detection_enabled = 1;
static int32_t bbr_min_measurements_req = 1; /* We need at least 2
* measurments before we are
* "good" note that 2 == 1.
* This is because we use a >
* comparison. This means if
* min_measure was 0, it takes
* num-measures > min(0) and
* you get 1 measurement and
* you are good. Set to 1, you
* have to have two
* measurements (this is done
* to prevent it from being ok
* to have no measurements). */
static int32_t bbr_no_pacing_until = 4;
static int32_t bbr_min_usec_delta = 20000; /* 20,000 usecs */
static int32_t bbr_min_peer_delta = 20; /* 20 units */
static int32_t bbr_delta_percent = 150; /* 15.0 % */
static int32_t bbr_target_cwnd_mult_limit = 8;
/*
* bbr_cwnd_min_val is the number of
* segments we hold to in the RTT probe
* state typically 4.
*/
static int32_t bbr_cwnd_min_val = BBR_PROBERTT_NUM_MSS;
static int32_t bbr_cwnd_min_val_hs = BBR_HIGHSPEED_NUM_MSS;
static int32_t bbr_gain_to_target = 1;
static int32_t bbr_gain_gets_extra_too = 1;
/*
* bbr_high_gain is the 2/ln(2) value we need
* to double the sending rate in startup. This
* is used for both cwnd and hptsi gain's.
*/
static int32_t bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1;
static int32_t bbr_startup_lower = BBR_UNIT * 1500 / 1000 + 1;
static int32_t bbr_use_lower_gain_in_startup = 1;
/* thresholds for reduction on drain in sub-states/drain */
static int32_t bbr_drain_rtt = BBR_SRTT;
static int32_t bbr_drain_floor = 88;
static int32_t google_allow_early_out = 1;
static int32_t google_consider_lost = 1;
static int32_t bbr_drain_drop_mul = 4;
static int32_t bbr_drain_drop_div = 5;
static int32_t bbr_rand_ot = 50;
static int32_t bbr_can_force_probertt = 0;
static int32_t bbr_can_adjust_probertt = 1;
static int32_t bbr_probertt_sets_rtt = 0;
static int32_t bbr_can_use_ts_for_rtt = 1;
static int32_t bbr_is_ratio = 0;
static int32_t bbr_sub_drain_app_limit = 1;
static int32_t bbr_prtt_slam_cwnd = 1;
static int32_t bbr_sub_drain_slam_cwnd = 1;
static int32_t bbr_slam_cwnd_in_main_drain = 1;
static int32_t bbr_filter_len_sec = 6; /* How long does the rttProp filter
* hold */
static uint32_t bbr_rtt_probe_limit = (USECS_IN_SECOND * 4);
/*
* bbr_drain_gain is the reverse of the high_gain
* designed to drain back out the standing queue
* that is formed in startup by causing a larger
* hptsi gain and thus drainging the packets
* in flight.
*/
static int32_t bbr_drain_gain = BBR_UNIT * 1000 / 2885;
static int32_t bbr_rttprobe_gain = 192;
/*
* The cwnd_gain is the default cwnd gain applied when
* calculating a target cwnd. Note that the cwnd is
* a secondary factor in the way BBR works (see the
* paper and think about it, it will take some time).
* Basically the hptsi_gain spreads the packets out
* so you never get more than BDP to the peer even
* if the cwnd is high. In our implemenation that
* means in non-recovery/retransmission scenarios
* cwnd will never be reached by the flight-size.
*/
static int32_t bbr_cwnd_gain = BBR_UNIT * 2;
static int32_t bbr_tlp_type_to_use = BBR_SRTT;
static int32_t bbr_delack_time = 100000; /* 100ms in useconds */
static int32_t bbr_sack_not_required = 0; /* set to one to allow non-sack to use bbr */
static int32_t bbr_initial_bw_bps = 62500; /* 500kbps in bytes ps */
static int32_t bbr_ignore_data_after_close = 1;
static int16_t bbr_hptsi_gain[] = {
(BBR_UNIT *5 / 4),
(BBR_UNIT * 3 / 4),
BBR_UNIT,
BBR_UNIT,
BBR_UNIT,
BBR_UNIT,
BBR_UNIT,
BBR_UNIT
};
int32_t bbr_use_rack_resend_cheat = 1;
int32_t bbr_sends_full_iwnd = 1;
#define BBR_HPTSI_GAIN_MAX 8
/*
* The BBR module incorporates a number of
* TCP ideas that have been put out into the IETF
* over the last few years:
* - 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.
* - Van Jacobson's et.al BBR.
*
* 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 BBR and 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. Data processing
* of inbound segments also now happens in the hpts_do_segment in general
* with only one exception. This is so we can keep the connection on
* a single CPU.
*
* 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 and has had hptsi
* integrated as a requirment. Still todo is to eliminate the
* use of the callout_() system and use the hpts for all
* timers as well.
*/
static uint32_t bbr_rtt_probe_time = 200000; /* 200ms in micro seconds */
static uint32_t bbr_rtt_probe_cwndtarg = 4; /* How many mss's outstanding */
static const int32_t bbr_min_req_free = 2; /* The min we must have on the
* free list */
static int32_t bbr_tlp_thresh = 1;
static int32_t bbr_reorder_thresh = 2;
static int32_t bbr_reorder_fade = 60000000; /* 0 - never fade, def
* 60,000,000 - 60 seconds */
static int32_t bbr_pkt_delay = 1000;
static int32_t bbr_min_to = 1000; /* Number of usec's minimum timeout */
static int32_t bbr_incr_timers = 1;
static int32_t bbr_tlp_min = 10000; /* 10ms in usecs */
static int32_t bbr_delayed_ack_time = 200000; /* 200ms in usecs */
static int32_t bbr_exit_startup_at_loss = 1;
/*
* bbr_lt_bw_ratio is 1/8th
* bbr_lt_bw_diff is < 4 Kbit/sec
*/
static uint64_t bbr_lt_bw_diff = 4000 / 8; /* In bytes per second */
static uint64_t bbr_lt_bw_ratio = 8; /* For 1/8th */
static uint32_t bbr_lt_bw_max_rtts = 48; /* How many rtt's do we use
* the lt_bw for */
static uint32_t bbr_lt_intvl_min_rtts = 4; /* Min num of RTT's to measure
* lt_bw */
static int32_t bbr_lt_intvl_fp = 0; /* False positive epoch diff */
static int32_t bbr_lt_loss_thresh = 196; /* Lost vs delivered % */
static int32_t bbr_lt_fd_thresh = 100; /* false detection % */
static int32_t bbr_verbose_logging = 0;
/*
* Currently regular tcp has a rto_min of 30ms
* the backoff goes 12 times so that ends up
* being a total of 122.850 seconds before a
* connection is killed.
*/
static int32_t bbr_rto_min_ms = 30; /* 30ms same as main freebsd */
static int32_t bbr_rto_max_sec = 4; /* 4 seconds */
/****************************************************/
/* DEFAULT TSO SIZING (cpu performance impacting) */
/****************************************************/
/* What amount is our formula using to get TSO size */
static int32_t bbr_hptsi_per_second = 1000;
/*
* For hptsi under bbr_cross_over connections what is delay
* target 7ms (in usec) combined with a seg_max of 2
* gets us close to identical google behavior in
* TSO size selection (possibly more 1MSS sends).
*/
static int32_t bbr_hptsi_segments_delay_tar = 7000;
/* Does pacing delay include overhead's in its time calculations? */
static int32_t bbr_include_enet_oh = 0;
static int32_t bbr_include_ip_oh = 1;
static int32_t bbr_include_tcp_oh = 1;
static int32_t bbr_google_discount = 10;
/* Do we use (nf mode) pkt-epoch to drive us or rttProp? */
static int32_t bbr_state_is_pkt_epoch = 0;
static int32_t bbr_state_drain_2_tar = 1;
/* What is the max the 0 - bbr_cross_over MBPS TSO target
* can reach using our delay target. Note that this
* value becomes the floor for the cross over
* algorithm.
*/
static int32_t bbr_hptsi_segments_max = 2;
static int32_t bbr_hptsi_segments_floor = 1;
static int32_t bbr_hptsi_utter_max = 0;
/* What is the min the 0 - bbr_cross-over MBPS TSO target can be */
static int32_t bbr_hptsi_bytes_min = 1460;
static int32_t bbr_all_get_min = 0;
/* Cross over point from algo-a to algo-b */
static uint32_t bbr_cross_over = TWENTY_THREE_MBPS;
/* Do we deal with our restart state? */
static int32_t bbr_uses_idle_restart = 0;
static int32_t bbr_idle_restart_threshold = 100000; /* 100ms in useconds */
/* Do we allow hardware pacing? */
static int32_t bbr_allow_hdwr_pacing = 0;
static int32_t bbr_hdwr_pace_adjust = 2; /* multipler when we calc the tso size */
static int32_t bbr_hdwr_pace_floor = 1;
static int32_t bbr_hdwr_pacing_delay_cnt = 10;
/****************************************************/
static int32_t bbr_resends_use_tso = 0;
static int32_t bbr_tlp_max_resend = 2;
static int32_t bbr_sack_block_limit = 128;
#define BBR_MAX_STAT 19
counter_u64_t bbr_state_time[BBR_MAX_STAT];
counter_u64_t bbr_state_lost[BBR_MAX_STAT];
counter_u64_t bbr_state_resend[BBR_MAX_STAT];
counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
counter_u64_t bbr_out_size[TCP_MSS_ACCT_SIZE];
counter_u64_t bbr_flows_whdwr_pacing;
counter_u64_t bbr_flows_nohdwr_pacing;
counter_u64_t bbr_nohdwr_pacing_enobuf;
counter_u64_t bbr_hdwr_pacing_enobuf;
static inline uint64_t bbr_get_bw(struct tcp_bbr *bbr);
/*
* Static defintions we need for forward declarations.
*/
static uint32_t
bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain,
uint32_t useconds_time, uint64_t bw);
static uint32_t
bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain);
static void
bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win);
static void
bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses);
static void
bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int line,
int dolog);
static uint32_t
bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain);
static void
bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch,
int32_t pkt_epoch, uint32_t losses);
static uint32_t
bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm);
static uint32_t bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp);
static uint32_t
bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
struct bbr_sendmap *rsm, uint32_t srtt,
uint32_t cts);
static void
bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
int32_t line);
static void
bbr_set_state_target(struct tcp_bbr *bbr, int line);
static void
bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line);
static void
bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line);
static void
tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts);
static void
bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts);
static void
bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied, uint32_t rtt,
uint32_t line, uint8_t is_start, uint16_t set);
static struct bbr_sendmap *
bbr_find_lowest_rsm(struct tcp_bbr *bbr);
static __inline uint32_t
bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type);
static void
bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which);
static void
bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
uint32_t thresh, uint32_t to);
static void
bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag);
static void
bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot,
uint32_t del_by, uint32_t cts, uint32_t sloton, uint32_t prev_delay);
static void
bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr,
uint32_t cts, int32_t line);
static void
bbr_stop_all_timers(struct tcpcb *tp);
static void
bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts);
static void
bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts);
static void
bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts);
static void
bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod);
static inline uint8_t
bbr_state_val(struct tcp_bbr *bbr)
{
return(bbr->rc_bbr_substate);
}
static inline uint32_t
get_min_cwnd(struct tcp_bbr *bbr)
{
int mss;
mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
if (bbr_get_rtt(bbr, BBR_RTT_PROP) < BBR_HIGH_SPEED)
return (bbr_cwnd_min_val_hs * mss);
else
return (bbr_cwnd_min_val * mss);
}
static uint32_t
bbr_get_persists_timer_val(struct tcpcb *tp, struct tcp_bbr *bbr)
{
uint64_t srtt, var;
uint64_t ret_val;
bbr->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
if (tp->t_srtt == 0) {
srtt = (uint64_t)BBR_INITIAL_RTO;
var = 0;
} else {
srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
var = ((uint64_t)TICKS_2_USEC(tp->t_rttvar) >> TCP_RTT_SHIFT);
}
TCPT_RANGESET_NOSLOP(ret_val, ((srtt + var) * tcp_backoff[tp->t_rxtshift]),
bbr_persist_min, bbr_persist_max);
return ((uint32_t)ret_val);
}
static uint32_t
bbr_timer_start(struct tcpcb *tp, struct tcp_bbr *bbr, 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, tstmp_touse;
int32_t idx;
int32_t is_tlp_timer = 0;
struct bbr_sendmap *rsm;
if (bbr->rc_all_timers_stopped) {
/* All timers have been stopped none are to run */
return (0);
}
if (bbr->rc_in_persist) {
/* We can't start any timer in persists */
return (bbr_get_persists_timer_val(tp, bbr));
}
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if ((rsm == NULL) ||
((tp->t_flags & TF_SACK_PERMIT) == 0) ||
(tp->t_state < TCPS_ESTABLISHED)) {
/* Nothing on the send map */
activate_rxt:
if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
uint64_t tov;
time_since_sent = 0;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if (rsm) {
idx = rsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(tstmp_touse, cts))
time_since_sent = cts - tstmp_touse;
}
bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
if (tp->t_srtt == 0)
tov = BBR_INITIAL_RTO;
else
tov = ((uint64_t)(TICKS_2_USEC(tp->t_srtt) +
((uint64_t)TICKS_2_USEC(tp->t_rttvar) * (uint64_t)4)) >> TCP_RTT_SHIFT);
if (tp->t_rxtshift)
tov *= tcp_backoff[tp->t_rxtshift];
if (tov > time_since_sent)
tov -= time_since_sent;
else
tov = bbr->r_ctl.rc_min_to;
TCPT_RANGESET_NOSLOP(to, tov,
(bbr->r_ctl.rc_min_rto_ms * MS_IN_USEC),
(bbr->rc_max_rto_sec * USECS_IN_SECOND));
bbr_log_timer_var(bbr, 2, cts, 0, srtt, 0, to);
return (to);
}
return (0);
}
if (rsm->r_flags & BBR_ACKED) {
rsm = bbr_find_lowest_rsm(bbr);
if (rsm == NULL) {
/* No lowest? */
goto activate_rxt;
}
}
/* Convert from ms to usecs */
if (rsm->r_flags & BBR_SACK_PASSED) {
if ((tp->t_flags & TF_SENTFIN) &&
((tp->snd_max - tp->snd_una) == 1) &&
(rsm->r_flags & BBR_HAS_FIN)) {
/*
* We don't start a bbr rack timer if all we have is
* a FIN outstanding.
*/
goto activate_rxt;
}
srtt = bbr_get_rtt(bbr, BBR_RTT_RACK);
thresh = bbr_calc_thresh_rack(bbr, srtt, cts, rsm);
idx = rsm->r_rtr_cnt - 1;
exp = rsm->r_tim_lastsent[idx] + thresh;
if (SEQ_GEQ(exp, cts)) {
to = exp - cts;
if (to < bbr->r_ctl.rc_min_to) {
to = bbr->r_ctl.rc_min_to;
}
} else {
to = bbr->r_ctl.rc_min_to;
}
} else {
/* Ok we need to do a TLP not RACK */
if (bbr->rc_tlp_in_progress != 0) {
/*
* The previous send was a TLP.
*/
goto activate_rxt;
}
rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
if (rsm == NULL) {
/* We found no rsm to TLP with. */
goto activate_rxt;
}
if (rsm->r_flags & BBR_HAS_FIN) {
/* If its a FIN we don't do TLP */
rsm = NULL;
goto activate_rxt;
}
time_since_sent = 0;
idx = rsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(tstmp_touse, cts))
time_since_sent = cts - tstmp_touse;
is_tlp_timer = 1;
srtt = bbr_get_rtt(bbr, bbr_tlp_type_to_use);
thresh = bbr_calc_thresh_tlp(tp, bbr, rsm, srtt, cts);
if (thresh > time_since_sent)
to = thresh - time_since_sent;
else
to = bbr->r_ctl.rc_min_to;
if (to > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
/*
* If the TLP time works out to larger than the max
* RTO lets not do TLP.. just RTO.
*/
goto activate_rxt;
}
if ((bbr->rc_tlp_rtx_out == 1) &&
(rsm->r_start == bbr->r_ctl.rc_last_tlp_seq)) {
/*
* Second retransmit of the same TLP
* lets not.
*/
bbr->rc_tlp_rtx_out = 0;
goto activate_rxt;
}
if (rsm->r_start != bbr->r_ctl.rc_last_tlp_seq) {
/*
* The tail is no longer the last one I did a probe
* on
*/
bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
}
}
if (is_tlp_timer == 0) {
BBR_STAT_INC(bbr_to_arm_rack);
bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
} else {
bbr_log_timer_var(bbr, 1, cts, time_since_sent, srtt, thresh, to);
if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_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 {
BBR_STAT_INC(bbr_to_arm_tlp);
bbr->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
}
}
return (to);
}
static inline int32_t
bbr_minseg(struct tcp_bbr *bbr)
{
return (bbr->r_ctl.rc_pace_min_segs - bbr->rc_last_options);
}
static void
bbr_start_hpts_timer(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts, int32_t frm, int32_t slot, uint32_t tot_len)
{
struct inpcb *inp;
struct hpts_diag diag;
uint32_t delayed_ack = 0;
uint32_t left = 0;
uint32_t hpts_timeout;
uint8_t stopped;
int32_t delay_calc = 0;
uint32_t prev_delay = 0;
inp = tp->t_inpcb;
if (inp->inp_in_hpts) {
/* A previous call is already set up */
return;
}
if ((tp->t_state == TCPS_CLOSED) ||
(tp->t_state == TCPS_LISTEN)) {
return;
}
stopped = bbr->rc_tmr_stopped;
if (stopped && TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
left = bbr->r_ctl.rc_timer_exp - cts;
}
bbr->r_ctl.rc_hpts_flags = 0;
bbr->r_ctl.rc_timer_exp = 0;
prev_delay = bbr->r_ctl.rc_last_delay_val;
if (bbr->r_ctl.rc_last_delay_val &&
(slot == 0)) {
/*
* If a previous pacer delay was in place we
* are not coming from the output side (where
* we calculate a delay, more likely a timer).
*/
slot = bbr->r_ctl.rc_last_delay_val;
if (TSTMP_GT(cts, bbr->rc_pacer_started)) {
/* Compensate for time passed */
delay_calc = cts - bbr->rc_pacer_started;
if (delay_calc <= slot)
slot -= delay_calc;
}
}
/* Do we have early to make up for by pushing out the pacing time? */
if (bbr->r_agg_early_set) {
bbr_log_pacing_delay_calc(bbr, 0, bbr->r_ctl.rc_agg_early, cts, slot, 0, bbr->r_agg_early_set, 2);
slot += bbr->r_ctl.rc_agg_early;
bbr->r_ctl.rc_agg_early = 0;
bbr->r_agg_early_set = 0;
}
/* Are we running a total debt that needs to be compensated for? */
if (bbr->r_ctl.rc_hptsi_agg_delay) {
if (slot > bbr->r_ctl.rc_hptsi_agg_delay) {
/* We nuke the delay */
slot -= bbr->r_ctl.rc_hptsi_agg_delay;
bbr->r_ctl.rc_hptsi_agg_delay = 0;
} else {
/* We nuke some of the delay, put in a minimal 100usecs */
bbr->r_ctl.rc_hptsi_agg_delay -= slot;
bbr->r_ctl.rc_last_delay_val = slot = 100;
}
}
bbr->r_ctl.rc_last_delay_val = slot;
hpts_timeout = bbr_timer_start(tp, bbr, cts);
if (tp->t_flags & TF_DELACK) {
if (bbr->rc_in_persist == 0) {
delayed_ack = bbr_delack_time;
} else {
/*
* We are in persists and have
* gotten a new data element.
*/
if (hpts_timeout > bbr_delack_time) {
/*
* Lets make the persists timer (which acks)
* be the smaller of hpts_timeout and bbr_delack_time.
*/
hpts_timeout = bbr_delack_time;
}
}
}
if (delayed_ack &&
((hpts_timeout == 0) ||
(delayed_ack < hpts_timeout))) {
/* We need a Delayed ack timer */
bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
hpts_timeout = delayed_ack;
}
if (slot) {
/* Mark that we have a pacing timer up */
BBR_STAT_INC(bbr_paced_segments);
bbr->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
}
/*
* If no timers are going to run and we will fall off thfe 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)) {
hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
} else {
hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
}
bbr->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
}
}
if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
(bbr->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 (bbr->r_ctl.rc_incr_tmrs && slot &&
(bbr->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
/*
* If configured to do so, and the timer is either
* the TLP or RXT timer, we need to increase the timeout
* by the pacing time. Consider the bottleneck at my
* machine as an example, we are sending something
* to start a TLP on. The last packet won't be emitted
* fully until the pacing time (the bottleneck will hold
* the data in place). Once the packet is emitted that
* is when we want to start waiting for the TLP. This
* is most evident with hardware pacing (where the nic
* is holding the packet(s) before emitting). But it
* can also show up in the network so we do it for all
* cases. Technically we would take off one packet from
* this extra delay but this is easier and being more
* conservative is probably better.
*/
hpts_timeout += slot;
}
if (hpts_timeout) {
/*
* Hack alert for now we can't time-out over 2147 seconds (a
* bit more than 35min)
*/
if (hpts_timeout > 0x7ffffffe)
hpts_timeout = 0x7ffffffe;
bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
} else
bbr->r_ctl.rc_timer_exp = 0;
if ((slot) &&
(bbr->rc_use_google ||
bbr->output_error_seen ||
(slot <= hpts_timeout)) ) {
/*
* Tell LRO that it can queue packets while
* we pace.
*/
bbr->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
(bbr->rc_cwnd_limited == 0)) {
/*
* If we are not cwnd limited and we
* are running a rack timer we put on
* the do not disturbe even for sack.
*/
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
} else
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
bbr->rc_pacer_started = cts;
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
__LINE__, &diag);
bbr->rc_timer_first = 0;
bbr->bbr_timer_src = frm;
bbr_log_to_start(bbr, cts, hpts_timeout, slot, 1);
bbr_log_hpts_diag(bbr, cts, &diag);
} else if (hpts_timeout) {
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
__LINE__, &diag);
/*
* We add the flag here as well if the slot is set,
* since hpts will call in to clear the queue first before
* calling the output routine (which does our timers).
* We don't want to set the flag if its just a timer
* else the arrival of data might (that causes us
* to send more) might get delayed. Imagine being
* on a keep-alive timer and a request comes in for
* more data.
*/
if (slot)
bbr->rc_pacer_started = cts;
if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
(bbr->rc_cwnd_limited == 0)) {
/*
* For a rack timer, don't wake us even
* if a sack arrives as long as we are
* not cwnd limited.
*/
bbr->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
} else {
/* All other timers wake us up */
bbr->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
bbr->bbr_timer_src = frm;
bbr_log_to_start(bbr, cts, hpts_timeout, slot, 0);
bbr_log_hpts_diag(bbr, cts, &diag);
bbr->rc_timer_first = 1;
}
bbr->rc_tmr_stopped = 0;
bbr_log_type_bbrsnd(bbr, tot_len, slot, delay_calc, cts, frm, prev_delay);
}
static void
bbr_timer_audit(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, 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 inpcb *inp;
struct bbr_sendmap *rsm;
uint32_t hpts_timeout;
int tmr_up;
tmr_up = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
if (bbr->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
return;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
(tmr_up == PACE_TMR_RXT)) {
/* Should be an RXT */
return;
}
inp = bbr->rc_inp;
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(&inp->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 ||
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 & BBR_SACK_PASSED)) {
if ((tp->t_flags & TF_SENTFIN) &&
((tp->snd_max - tp->snd_una) == 1) &&
(rsm->r_flags & BBR_HAS_FIN)) {
/* needs to be a RXT */
if (tmr_up == PACE_TMR_RXT)
return;
else
goto wrong_timer;
} else if (tmr_up == PACE_TMR_RACK)
return;
else
goto wrong_timer;
} else if (rsm && (tmr_up == PACE_TMR_RACK)) {
/* Rack timer has priority if we have data out */
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;
}
if (SEQ_GT(tp->snd_max, tp->snd_una) &&
((tmr_up == PACE_TMR_RXT) ||
(tmr_up == PACE_TMR_TLP) ||
(tmr_up == PACE_TMR_RACK))) {
/*
* We have outstanding data and
* we *do* have a RACK, TLP or RXT
* timer running. We won't restart
* anything here since thats probably ok we
* will get called with some timer here shortly.
*/
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.
*/
wrong_timer:
if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) {
if (inp->inp_in_hpts)
tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
bbr_timer_cancel(bbr, __LINE__, cts);
bbr_start_hpts_timer(bbr, tp, cts, 1, bbr->r_ctl.rc_last_delay_val,
0);
} else {
/*
* Output is hptsi so we just need to switch the type of
* timer. We don't bother with keep-alive, since when we
* jump through the output, it will start the keep-alive if
* nothing is sent.
*
* We only need a delayed-ack added and or the hpts_timeout.
*/
hpts_timeout = bbr_timer_start(tp, bbr, cts);
if (tp->t_flags & TF_DELACK) {
if (hpts_timeout == 0) {
hpts_timeout = bbr_delack_time;
bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
}
else if (hpts_timeout > bbr_delack_time) {
hpts_timeout = bbr_delack_time;
bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
}
}
if (hpts_timeout) {
if (hpts_timeout > 0x7ffffffe)
hpts_timeout = 0x7ffffffe;
bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
}
}
}
int32_t bbr_clear_lost = 0;
/*
* Considers the two time values now (cts) and earlier.
* If cts is smaller than earlier, we could have
* had a sequence wrap (our counter wraps every
* 70 min or so) or it could be just clock skew
* getting us two differnt time values. Clock skew
* will show up within 10ms or so. So in such
* a case (where cts is behind earlier time by
* less than 10ms) we return 0. Otherwise we
* return the true difference between them.
*/
static inline uint32_t
bbr_calc_time(uint32_t cts, uint32_t earlier_time) {
/*
* Given two timestamps, the current time stamp cts, and some other
* time-stamp taken in theory earlier return the difference. The
* trick is here sometimes locking will get the other timestamp
* after the cts. If this occurs we need to return 0.
*/
if (TSTMP_GEQ(cts, earlier_time))
return (cts - earlier_time);
/*
* cts is behind earlier_time if its less than 10ms consider it 0.
* If its more than 10ms difference then we had a time wrap. Else
* its just the normal locking foo. I wonder if we should not go to
* 64bit TS and get rid of this issue.
*/
if (TSTMP_GEQ((cts + 10000), earlier_time))
return (0);
/*
* Ok the time must have wrapped. So we need to answer a large
* amount of time, which the normal subtraction should do.
*/
return (cts - earlier_time);
}
static int
sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)
{
uint32_t stat;
int32_t error;
error = SYSCTL_OUT(req, &bbr_clear_lost, 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 BBR_INVARIANTS
printf("Clearing BBR lost counters\n");
#endif
COUNTER_ARRAY_ZERO(bbr_state_lost, BBR_MAX_STAT);
COUNTER_ARRAY_ZERO(bbr_state_time, BBR_MAX_STAT);
COUNTER_ARRAY_ZERO(bbr_state_resend, BBR_MAX_STAT);
} else if (stat == 2) {
#ifdef BBR_INVARIANTS
printf("Clearing BBR option counters\n");
#endif
COUNTER_ARRAY_ZERO(bbr_opts_arry, BBR_OPTS_SIZE);
} else if (stat == 3) {
#ifdef BBR_INVARIANTS
printf("Clearing BBR stats counters\n");
#endif
COUNTER_ARRAY_ZERO(bbr_stat_arry, BBR_STAT_SIZE);
} else if (stat == 4) {
#ifdef BBR_INVARIANTS
printf("Clearing BBR out-size counters\n");
#endif
COUNTER_ARRAY_ZERO(bbr_out_size, TCP_MSS_ACCT_SIZE);
}
bbr_clear_lost = 0;
return (0);
}
static void
bbr_init_sysctls(void)
{
struct sysctl_oid *bbr_probertt;
struct sysctl_oid *bbr_hptsi;
struct sysctl_oid *bbr_measure;
struct sysctl_oid *bbr_cwnd;
struct sysctl_oid *bbr_timeout;
struct sysctl_oid *bbr_states;
struct sysctl_oid *bbr_startup;
struct sysctl_oid *bbr_policer;
/* Probe rtt controls */
bbr_probertt = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"probertt",
CTLFLAG_RW, 0,
"");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "gain", CTLFLAG_RW,
&bbr_rttprobe_gain, 192,
"What is the filter gain drop in probe_rtt (0=disable)?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "cwnd", CTLFLAG_RW,
&bbr_rtt_probe_cwndtarg, 4,
"How many mss's are outstanding during probe-rtt");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "int", CTLFLAG_RW,
&bbr_rtt_probe_limit, 4000000,
"If RTT has not shrank in this many micro-seconds enter probe-rtt");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "mintime", CTLFLAG_RW,
&bbr_rtt_probe_time, 200000,
"How many microseconds in probe-rtt");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "filter_len_sec", CTLFLAG_RW,
&bbr_filter_len_sec, 6,
"How long in seconds does the rttProp filter run?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "drain_rtt", CTLFLAG_RW,
&bbr_drain_rtt, BBR_SRTT,
"What is the drain rtt to use in probeRTT (rtt_prop=0, rtt_rack=1, rtt_pkt=2, rtt_srtt=3?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "can_force", CTLFLAG_RW,
&bbr_can_force_probertt, 0,
"If we keep setting new low rtt's but delay going in probe-rtt can we force in??");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "enter_sets_force", CTLFLAG_RW,
&bbr_probertt_sets_rtt, 0,
"In NF mode, do we imitate google_mode and set the rttProp on entry to probe-rtt?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "can_adjust", CTLFLAG_RW,
&bbr_can_adjust_probertt, 1,
"Can we dynamically adjust the probe-rtt limits and times?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "is_ratio", CTLFLAG_RW,
&bbr_is_ratio, 0,
"is the limit to filter a ratio?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "use_cwnd", CTLFLAG_RW,
&bbr_prtt_slam_cwnd, 0,
"Should we set/recover cwnd?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_probertt),
OID_AUTO, "can_use_ts", CTLFLAG_RW,
&bbr_can_use_ts_for_rtt, 1,
"Can we use the ms timestamp if available for retransmistted rtt calculations?");
/* Pacing controls */
bbr_hptsi = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"pacing",
CTLFLAG_RW, 0,
"");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "hw_pacing", CTLFLAG_RW,
&bbr_allow_hdwr_pacing, 1,
"Do we allow hardware pacing?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "hw_pacing_limit", CTLFLAG_RW,
&bbr_hardware_pacing_limit, 4000,
"Do we have a limited number of connections for pacing chelsio (0=no limit)?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "hw_pacing_adj", CTLFLAG_RW,
&bbr_hdwr_pace_adjust, 2,
"Multiplier to calculated tso size?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "hw_pacing_floor", CTLFLAG_RW,
&bbr_hdwr_pace_floor, 1,
"Do we invoke the hardware pacing floor?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "hw_pacing_delay_cnt", CTLFLAG_RW,
&bbr_hdwr_pacing_delay_cnt, 10,
"How many packets must be sent after hdwr pacing is enabled");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "bw_cross", CTLFLAG_RW,
&bbr_cross_over, 3000000,
"What is the point where we cross over to linux like TSO size set");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "seg_deltarg", CTLFLAG_RW,
&bbr_hptsi_segments_delay_tar, 7000,
"What is the worse case delay target for hptsi < 48Mbp connections");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "enet_oh", CTLFLAG_RW,
&bbr_include_enet_oh, 0,
"Do we include the ethernet overhead in calculating pacing delay?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "ip_oh", CTLFLAG_RW,
&bbr_include_ip_oh, 1,
"Do we include the IP overhead in calculating pacing delay?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "tcp_oh", CTLFLAG_RW,
&bbr_include_tcp_oh, 0,
"Do we include the TCP overhead in calculating pacing delay?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "google_discount", CTLFLAG_RW,
&bbr_google_discount, 10,
"What is the default google discount percentage wise for pacing (11 = 1.1%%)?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "all_get_min", CTLFLAG_RW,
&bbr_all_get_min, 0,
"If you are less than a MSS do you just get the min?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "tso_min", CTLFLAG_RW,
&bbr_hptsi_bytes_min, 1460,
"For 0 -> 24Mbps what is floor number of segments for TSO");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "seg_tso_max", CTLFLAG_RW,
&bbr_hptsi_segments_max, 6,
"For 0 -> 24Mbps what is top number of segments for TSO");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "seg_floor", CTLFLAG_RW,
&bbr_hptsi_segments_floor, 1,
"Minimum TSO size we will fall too in segments");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "utter_max", CTLFLAG_RW,
&bbr_hptsi_utter_max, 0,
"The absolute maximum that any pacing (outside of hardware) can be");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "seg_divisor", CTLFLAG_RW,
&bbr_hptsi_per_second, 100,
"What is the divisor in our hptsi TSO calculation 512Mbps < X > 24Mbps ");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "srtt_mul", CTLFLAG_RW,
&bbr_hptsi_max_mul, 1,
"The multiplier for pace len max");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_hptsi),
OID_AUTO, "srtt_div", CTLFLAG_RW,
&bbr_hptsi_max_div, 2,
"The divisor for pace len max");
/* Measurement controls */
bbr_measure = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"measure",
CTLFLAG_RW, 0,
"Measurement controls");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "min_i_bw", CTLFLAG_RW,
&bbr_initial_bw_bps, 62500,
"Minimum initial b/w in bytes per second");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "no_sack_needed", CTLFLAG_RW,
&bbr_sack_not_required, 0,
"Do we allow bbr to run on connections not supporting SACK?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "use_google", CTLFLAG_RW,
&bbr_use_google_algo, 0,
"Use has close to google V1.0 has possible?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "ts_limiting", CTLFLAG_RW,
&bbr_ts_limiting, 1,
"Do we attempt to use the peers timestamp to limit b/w caculations?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "ts_can_raise", CTLFLAG_RW,
&bbr_ts_can_raise, 0,
"Can we raise the b/w via timestamp b/w calculation?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "ts_delta", CTLFLAG_RW,
&bbr_min_usec_delta, 20000,
"How long in usec between ts of our sends in ts validation code?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "ts_peer_delta", CTLFLAG_RW,
&bbr_min_peer_delta, 20,
"What min numerical value should be between the peer deltas?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "ts_delta_percent", CTLFLAG_RW,
&bbr_delta_percent, 150,
"What percentage (150 = 15.0) do we allow variance for?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "min_measure_good_bw", CTLFLAG_RW,
&bbr_min_measurements_req, 1,
"What is the minimum measurment count we need before we switch to our b/w estimate");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "min_measure_before_pace", CTLFLAG_RW,
&bbr_no_pacing_until, 4,
"How many pkt-epoch's (0 is off) do we need before pacing is on?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "quanta", CTLFLAG_RW,
&bbr_quanta, 2,
"Extra quanta to add when calculating the target (ID section 4.2.3.2).");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_measure),
OID_AUTO, "noretran", CTLFLAG_RW,
&bbr_no_retran, 0,
"Should google mode not use retransmission measurements for the b/w estimation?");
/* State controls */
bbr_states = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"states",
CTLFLAG_RW, 0,
"State controls");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "idle_restart", CTLFLAG_RW,
&bbr_uses_idle_restart, 0,
"Do we use a new special idle_restart state to ramp back up quickly?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "idle_restart_threshold", CTLFLAG_RW,
&bbr_idle_restart_threshold, 100000,
"How long must we be idle before we restart??");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "use_pkt_epoch", CTLFLAG_RW,
&bbr_state_is_pkt_epoch, 0,
"Do we use a pkt-epoch for substate if 0 rttProp?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "startup_rtt_gain", CTLFLAG_RW,
&bbr_rtt_gain_thresh, 0,
"What increase in RTT triggers us to stop ignoring no-loss and possibly exit startup?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "drain_floor", CTLFLAG_RW,
&bbr_drain_floor, 88,
"What is the lowest we can drain (pg) too?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "drain_2_target", CTLFLAG_RW,
&bbr_state_drain_2_tar, 1,
"Do we drain to target in drain substate?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "gain_2_target", CTLFLAG_RW,
&bbr_gain_to_target, 1,
"Does probe bw gain to target??");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "gain_extra_time", CTLFLAG_RW,
&bbr_gain_gets_extra_too, 1,
"Does probe bw gain get the extra time too?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "ld_div", CTLFLAG_RW,
&bbr_drain_drop_div, 5,
"Long drain drop divider?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "ld_mul", CTLFLAG_RW,
&bbr_drain_drop_mul, 4,
"Long drain drop multiplier?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "rand_ot_disc", CTLFLAG_RW,
&bbr_rand_ot, 50,
"Random discount of the ot?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "dr_filter_life", CTLFLAG_RW,
&bbr_num_pktepo_for_del_limit, BBR_NUM_RTTS_FOR_DEL_LIMIT,
"How many packet-epochs does the b/w delivery rate last?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "subdrain_applimited", CTLFLAG_RW,
&bbr_sub_drain_app_limit, 0,
"Does our sub-state drain invoke app limited if its long?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "use_cwnd_subdrain", CTLFLAG_RW,
&bbr_sub_drain_slam_cwnd, 0,
"Should we set/recover cwnd for sub-state drain?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "use_cwnd_maindrain", CTLFLAG_RW,
&bbr_slam_cwnd_in_main_drain, 0,
"Should we set/recover cwnd for main-state drain?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "google_gets_earlyout", CTLFLAG_RW,
&google_allow_early_out, 1,
"Should we allow google probe-bw/drain to exit early at flight target?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_states),
OID_AUTO, "google_exit_loss", CTLFLAG_RW,
&google_consider_lost, 1,
"Should we have losses exit gain of probebw in google mode??");
/* Startup controls */
bbr_startup = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"startup",
CTLFLAG_RW, 0,
"Startup controls");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "cheat_iwnd", CTLFLAG_RW,
&bbr_sends_full_iwnd, 1,
"Do we not pace but burst out initial windows has our TSO size?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "loss_threshold", CTLFLAG_RW,
&bbr_startup_loss_thresh, 2000,
"In startup what is the loss threshold in a pe that will exit us from startup?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "use_lowerpg", CTLFLAG_RW,
&bbr_use_lower_gain_in_startup, 1,
"Should we use a lower hptsi gain if we see loss in startup?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "gain", CTLFLAG_RW,
&bbr_start_exit, 25,
"What gain percent do we need to see to stay in startup??");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "low_gain", CTLFLAG_RW,
&bbr_low_start_exit, 15,
"What gain percent do we need to see to stay in the lower gain startup??");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_startup),
OID_AUTO, "loss_exit", CTLFLAG_RW,
&bbr_exit_startup_at_loss, 1,
"Should we exit startup at loss in an epoch if we are not gaining?");
/* CWND controls */
bbr_cwnd = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"cwnd",
CTLFLAG_RW, 0,
"Cwnd controls");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "tar_rtt", CTLFLAG_RW,
&bbr_cwndtarget_rtt_touse, 0,
"Target cwnd rtt measurment to use (0=rtt_prop, 1=rtt_rack, 2=pkt_rtt, 3=srtt)?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "may_shrink", CTLFLAG_RW,
&bbr_cwnd_may_shrink, 0,
"Can the cwnd shrink if it would grow to more than the target?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "max_target_limit", CTLFLAG_RW,
&bbr_target_cwnd_mult_limit, 8,
"Do we limit the cwnd to some multiple of the cwnd target if cwnd can't shrink 0=no?");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "highspeed_min", CTLFLAG_RW,
&bbr_cwnd_min_val_hs, BBR_HIGHSPEED_NUM_MSS,
"What is the high-speed min cwnd (rttProp under 1ms)");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "lowspeed_min", CTLFLAG_RW,
&bbr_cwnd_min_val, BBR_PROBERTT_NUM_MSS,
"What is the min cwnd (rttProp > 1ms)");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "initwin", CTLFLAG_RW,
&bbr_def_init_win, 10,
"What is the BBR initial window, if 0 use tcp version");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "do_loss_red", CTLFLAG_RW,
&bbr_do_red, 600,
"Do we reduce the b/w at exit from recovery based on ratio of prop/srtt (800=80.0, 0=off)?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "red_scale", CTLFLAG_RW,
&bbr_red_scale, 20000,
"What RTT do we scale with?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "red_growslow", CTLFLAG_RW,
&bbr_red_growth_restrict, 1,
"Do we restrict cwnd growth for whats in flight?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "red_div", CTLFLAG_RW,
&bbr_red_div, 2,
"If we reduce whats the divisor?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "red_mul", CTLFLAG_RW,
&bbr_red_mul, 1,
"If we reduce whats the mulitiplier?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "target_is_unit", CTLFLAG_RW,
&bbr_target_is_bbunit, 0,
"Is the state target the pacing_gain or BBR_UNIT?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_cwnd),
OID_AUTO, "drop_limit", CTLFLAG_RW,
&bbr_drop_limit, 0,
"Number of segments limit for drop (0=use min_cwnd w/flight)?");
/* Timeout controls */
bbr_timeout = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"timeout",
CTLFLAG_RW, 0,
"Time out controls");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "delack", CTLFLAG_RW,
&bbr_delack_time, 100000,
"BBR's delayed ack time");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "tlp_uses", CTLFLAG_RW,
&bbr_tlp_type_to_use, 3,
"RTT that TLP uses in its calculations, 0=rttProp, 1=Rack_rtt, 2=pkt_rtt and 3=srtt");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "persmin", CTLFLAG_RW,
&bbr_persist_min, 250000,
"What is the minimum time in microseconds between persists");
SYSCTL_ADD_U32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "persmax", CTLFLAG_RW,
&bbr_persist_max, 1000000,
"What is the largest delay in microseconds between persists");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "tlp_minto", CTLFLAG_RW,
&bbr_tlp_min, 10000,
"TLP Min timeout in usecs");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "tlp_dack_time", CTLFLAG_RW,
&bbr_delayed_ack_time, 200000,
"TLP delayed ack compensation value");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "minrto", CTLFLAG_RW,
&bbr_rto_min_ms, 30,
"Minimum RTO in ms");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "maxrto", CTLFLAG_RW,
&bbr_rto_max_sec, 4,
"Maxiumum RTO in seconds -- should be at least as large as min_rto");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "tlp_retry", CTLFLAG_RW,
&bbr_tlp_max_resend, 2,
"How many times does TLP retry a single segment or multiple with no ACK");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "minto", CTLFLAG_RW,
&bbr_min_to, 1000,
"Minimum rack timeout in useconds");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "pktdelay", CTLFLAG_RW,
&bbr_pkt_delay, 1000,
"Extra RACK time (in useconds) besides reordering thresh");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "incr_tmrs", CTLFLAG_RW,
&bbr_incr_timers, 1,
"Increase the RXT/TLP timer by the pacing time used?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_timeout),
OID_AUTO, "rxtmark_sackpassed", CTLFLAG_RW,
&bbr_marks_rxt_sack_passed, 0,
"Mark sack passed on all those not ack'd when a RXT hits?");
/* Policer controls */
bbr_policer = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO,
"policer",
CTLFLAG_RW, 0,
"Policer controls");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "detect_enable", CTLFLAG_RW,
&bbr_policer_detection_enabled, 1,
"Is policer detection enabled??");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "min_pes", CTLFLAG_RW,
&bbr_lt_intvl_min_rtts, 4,
"Minimum number of PE's?");
SYSCTL_ADD_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "bwdiff", CTLFLAG_RW,
&bbr_lt_bw_diff, (4000/8),
"Minimal bw diff?");
SYSCTL_ADD_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "bwratio", CTLFLAG_RW,
&bbr_lt_bw_ratio, 8,
"Minimal bw diff?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "from_rack_rxt", CTLFLAG_RW,
&bbr_policer_call_from_rack_to, 0,
"Do we call the policer detection code from a rack-timeout?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "false_postive", CTLFLAG_RW,
&bbr_lt_intvl_fp, 0,
"What packet epoch do we do false-postive detection at (0=no)?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "loss_thresh", CTLFLAG_RW,
&bbr_lt_loss_thresh, 196,
"Loss threshold 196 = 19.6%?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_policer),
OID_AUTO, "false_postive_thresh", CTLFLAG_RW,
&bbr_lt_fd_thresh, 100,
"What percentage is the false detection threshold (150=15.0)?");
/* All the rest */
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "cheat_rxt", CTLFLAG_RW,
&bbr_use_rack_resend_cheat, 0,
"Do we burst 1ms between sends on retransmissions (like rack)?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "error_paceout", CTLFLAG_RW,
&bbr_error_base_paceout, 10000,
"When we hit an error what is the min to pace out in usec's?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "kill_paceout", CTLFLAG_RW,
&bbr_max_net_error_cnt, 10,
"When we hit this many errors in a row, kill the session?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "data_after_close", CTLFLAG_RW,
&bbr_ignore_data_after_close, 1,
"Do we hold off sending a RST until all pending data is ack'd");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "resend_use_tso", CTLFLAG_RW,
&bbr_resends_use_tso, 0,
"Can resends use TSO?");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "sblklimit", CTLFLAG_RW,
&bbr_sack_block_limit, 128,
"When do we start ignoring small sack blocks");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "bb_verbose", CTLFLAG_RW,
&bbr_verbose_logging, 0,
"Should BBR black box logging be verbose");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "reorder_thresh", CTLFLAG_RW,
&bbr_reorder_thresh, 2,
"What factor for rack will be added when seeing reordering (shift right)");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "reorder_fade", CTLFLAG_RW,
&bbr_reorder_fade, 0,
"Does reorder detection fade, if so how many ms (0 means never)");
SYSCTL_ADD_S32(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
&bbr_tlp_thresh, 1,
"what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
/* Stats and counters */
/* The pacing counters for hdwr/software can't be in the array */
bbr_nohdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
bbr_hdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "enob_hdwr_pacing", CTLFLAG_RD,
&bbr_hdwr_pacing_enobuf,
"Total number of enobufs for hardware paced flows");
SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "enob_no_hdwr_pacing", CTLFLAG_RD,
&bbr_nohdwr_pacing_enobuf,
"Total number of enobufs for non-hardware paced flows");
bbr_flows_whdwr_pacing = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "hdwr_pacing", CTLFLAG_RD,
&bbr_flows_whdwr_pacing,
"Total number of hardware paced flows");
bbr_flows_nohdwr_pacing = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "software_pacing", CTLFLAG_RD,
&bbr_flows_nohdwr_pacing,
"Total number of software paced flows");
COUNTER_ARRAY_ALLOC(bbr_stat_arry, BBR_STAT_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "stats", CTLFLAG_RD,
bbr_stat_arry, BBR_STAT_SIZE, "BBR Stats");
COUNTER_ARRAY_ALLOC(bbr_opts_arry, BBR_OPTS_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "opts", CTLFLAG_RD,
bbr_opts_arry, BBR_OPTS_SIZE, "BBR Option Stats");
COUNTER_ARRAY_ALLOC(bbr_state_lost, BBR_MAX_STAT, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "lost", CTLFLAG_RD,
bbr_state_lost, BBR_MAX_STAT, "Stats of when losses occur");
COUNTER_ARRAY_ALLOC(bbr_state_resend, BBR_MAX_STAT, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "stateresend", CTLFLAG_RD,
bbr_state_resend, BBR_MAX_STAT, "Stats of what states resend");
COUNTER_ARRAY_ALLOC(bbr_state_time, BBR_MAX_STAT, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "statetime", CTLFLAG_RD,
bbr_state_time, BBR_MAX_STAT, "Stats of time spent in the states");
COUNTER_ARRAY_ALLOC(bbr_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "outsize", CTLFLAG_RD,
bbr_out_size, TCP_MSS_ACCT_SIZE, "Size of output calls");
SYSCTL_ADD_PROC(&bbr_sysctl_ctx,
SYSCTL_CHILDREN(bbr_sysctl_root),
OID_AUTO, "clrlost", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
&bbr_clear_lost, 0, sysctl_bbr_clear_lost, "IU", "Clear lost counters");
}
static inline int32_t
bbr_progress_timeout_check(struct tcp_bbr *bbr)
{
if (bbr->rc_tp->t_maxunacktime && bbr->rc_tp->t_acktime &&
TSTMP_GT(ticks, bbr->rc_tp->t_acktime)) {
if ((((uint32_t)ticks - bbr->rc_tp->t_acktime)) >= bbr->rc_tp->t_maxunacktime) {
/*
* There is an assumption here that the caller will
* drop the connection, so we increment the
* statistics.
*/
bbr_log_progress_event(bbr, bbr->rc_tp, ticks, PROGRESS_DROP, __LINE__);
BBR_STAT_INC(bbr_progress_drops);
#ifdef NETFLIX_STATS
TCPSTAT_INC(tcps_progdrops);
#endif
return (1);
}
}
return (0);
}
static void
bbr_counter_destroy(void)
{
COUNTER_ARRAY_FREE(bbr_stat_arry, BBR_STAT_SIZE);
COUNTER_ARRAY_FREE(bbr_opts_arry, BBR_OPTS_SIZE);
COUNTER_ARRAY_FREE(bbr_out_size, TCP_MSS_ACCT_SIZE);
COUNTER_ARRAY_FREE(bbr_state_lost, BBR_MAX_STAT);
COUNTER_ARRAY_FREE(bbr_state_time, BBR_MAX_STAT);
COUNTER_ARRAY_FREE(bbr_state_resend, BBR_MAX_STAT);
counter_u64_free(bbr_flows_whdwr_pacing);
counter_u64_free(bbr_flows_nohdwr_pacing);
}
static __inline void
bbr_fill_in_logging_data(struct tcp_bbr *bbr, struct tcp_log_bbr *l, uint32_t cts)
{
memset(l, 0, sizeof(union tcp_log_stackspecific));
l->cur_del_rate = bbr->r_ctl.rc_bbr_cur_del_rate;
l->delRate = get_filter_value(&bbr->r_ctl.rc_delrate);
l->rttProp = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
l->bw_inuse = bbr_get_bw(bbr);
l->inflight = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
l->applimited = bbr->r_ctl.r_app_limited_until;
l->delivered = bbr->r_ctl.rc_delivered;
l->timeStamp = cts;
l->lost = bbr->r_ctl.rc_lost;
l->bbr_state = bbr->rc_bbr_state;
l->bbr_substate = bbr_state_val(bbr);
l->epoch = bbr->r_ctl.rc_rtt_epoch;
l->lt_epoch = bbr->r_ctl.rc_lt_epoch;
l->pacing_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
l->cwnd_gain = bbr->r_ctl.rc_bbr_cwnd_gain;
l->inhpts = bbr->rc_inp->inp_in_hpts;
l->ininput = bbr->rc_inp->inp_in_input;
l->use_lt_bw = bbr->rc_lt_use_bw;
l->pkts_out = bbr->r_ctl.rc_flight_at_input;
l->pkt_epoch = bbr->r_ctl.rc_pkt_epoch;
}
static void
bbr_log_type_bw_reduce(struct tcp_bbr *bbr, int reason)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = 0;
log.u_bbr.flex2 = 0;
log.u_bbr.flex5 = 0;
log.u_bbr.flex3 = 0;
log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_loss_rate;
log.u_bbr.flex7 = reason;
log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_enters_probertt;
log.u_bbr.flex8 = 0;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BW_RED_EV, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_rwnd_collapse(struct tcp_bbr *bbr, int seq, int mode, uint32_t count)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = seq;
log.u_bbr.flex2 = count;
log.u_bbr.flex8 = mode;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_LOWGAIN, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_just_return(struct tcp_bbr *bbr, uint32_t cts, uint32_t tlen, uint8_t hpts_calling,
uint8_t reason, uint32_t p_maxseg, int len)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = p_maxseg;
log.u_bbr.flex2 = bbr->r_ctl.rc_hpts_flags;
log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
log.u_bbr.flex4 = reason;
log.u_bbr.flex5 = bbr->rc_in_persist;
log.u_bbr.flex6 = bbr->r_ctl.rc_last_delay_val;
log.u_bbr.flex7 = p_maxseg;
log.u_bbr.flex8 = bbr->rc_in_persist;
log.u_bbr.pkts_out = 0;
log.u_bbr.applimited = len;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_JUSTRET, 0,
tlen, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_enter_rec(struct tcp_bbr *bbr, uint32_t seq)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = seq;
log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
log.u_bbr.flex3 = bbr->r_ctl.rc_recovery_start;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_ENTREC, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_msgsize_fail(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t len, uint32_t maxseg, uint32_t mtu, int32_t csum_flags, int32_t tso, uint32_t cts)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = tso;
log.u_bbr.flex2 = maxseg;
log.u_bbr.flex3 = mtu;
log.u_bbr.flex4 = csum_flags;
TCP_LOG_EVENTP(tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_MSGSIZE, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_flowend(struct tcp_bbr *bbr)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct sockbuf *r, *s;
struct timeval tv;
if (bbr->rc_inp->inp_socket) {
r = &bbr->rc_inp->inp_socket->so_rcv;
s = &bbr->rc_inp->inp_socket->so_snd;
} else {
r = s = NULL;
}
bbr_fill_in_logging_data(bbr, &log.u_bbr, tcp_get_usecs(&tv));
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
r, s,
TCP_LOG_FLOWEND, 0,
0, &log, false, &tv);
}
}
static void
bbr_log_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line,
uint32_t lost, uint32_t del)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = lost;
log.u_bbr.flex2 = del;
log.u_bbr.flex3 = bbr->r_ctl.rc_bbr_lastbtlbw;
log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_rtt;
log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
log.u_bbr.flex7 = line;
log.u_bbr.flex8 = 0;
log.u_bbr.inflight = bbr->r_ctl.r_measurement_count;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_PKT_EPOCH, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_time_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line, uint32_t epoch_time)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->r_ctl.rc_lost;
log.u_bbr.flex2 = bbr->rc_inp->inp_socket->so_snd.sb_lowat;
log.u_bbr.flex3 = bbr->rc_inp->inp_socket->so_snd.sb_hiwat;
log.u_bbr.flex7 = line;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TIME_EPOCH, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_set_of_state_target(struct tcp_bbr *bbr, uint32_t new_tar, int line, int meth)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex2 = new_tar;
log.u_bbr.flex3 = line;
log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
log.u_bbr.flex5 = bbr_quanta;
log.u_bbr.flex6 = bbr->r_ctl.rc_pace_min_segs;
log.u_bbr.flex7 = bbr->rc_last_options;
log.u_bbr.flex8 = meth;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_STATE_TARGET, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_statechange(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
if (bbr_state_is_pkt_epoch)
log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
else
log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PROP);
log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
log.u_bbr.flex7 = (bbr->r_ctl.rc_target_at_state/1000);
log.u_bbr.lt_epoch = bbr->r_ctl.rc_level_state_extra;
log.u_bbr.pkts_out = bbr->r_ctl.rc_target_at_state;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_STATE, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
uint32_t rtt, uint32_t line, uint8_t reas, uint16_t cond)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
log.u_bbr.flex3 = bbr->r_ctl.last_in_probertt;
log.u_bbr.flex4 = applied;
log.u_bbr.flex5 = rtt;
log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex7 = cond;
log.u_bbr.flex8 = reas;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_RTT_SHRINKS, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_exit_rec(struct tcp_bbr *bbr)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = bbr->r_ctl.rc_recovery_start;
log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_EXITREC, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_cwndupd(struct tcp_bbr *bbr, uint32_t bytes_this_ack, uint32_t chg,
uint32_t prev_acked, int32_t meth, uint32_t target, uint32_t th_ack, int32_t line)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = prev_acked;
log.u_bbr.flex3 = bytes_this_ack;
log.u_bbr.flex4 = chg;
log.u_bbr.flex5 = th_ack;
log.u_bbr.flex6 = target;
log.u_bbr.flex8 = meth;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_CWND, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_rtt_sample(struct tcp_bbr *bbr, uint32_t rtt, uint32_t tsin)
{
/*
* Log the rtt sample we are applying to the srtt algorithm in
* useconds.
*/
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = rtt;
log.u_bbr.flex2 = bbr->r_ctl.rc_bbr_state_time;
log.u_bbr.flex3 = bbr->r_ctl.rc_ack_hdwr_delay;
log.u_bbr.flex4 = bbr->rc_tp->ts_offset;
log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.pkts_out = tcp_tv_to_mssectick(&bbr->rc_tv);
log.u_bbr.flex6 = tsin;
log.u_bbr.flex7 = 0;
log.u_bbr.flex8 = bbr->rc_ack_was_delayed;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
TCP_LOG_RTT, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_pesist(struct tcp_bbr *bbr, uint32_t cts, uint32_t time_in, int32_t line, uint8_t enter_exit)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = time_in;
log.u_bbr.flex2 = line;
log.u_bbr.flex8 = enter_exit;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_PERSIST, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_ack_clear(struct tcp_bbr *bbr, uint32_t cts)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->rc_tp->ts_recent_age;
log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
log.u_bbr.flex4 = bbr->r_ctl.rc_went_idle_time;
log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_ACKCLEAR, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_ack_event(struct tcp_bbr *bbr, struct tcphdr *th, struct tcpopt *to, uint32_t tlen,
uint16_t nsegs, uint32_t cts, int32_t nxt_pkt, struct mbuf *m)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = nsegs;
log.u_bbr.flex2 = bbr->r_ctl.rc_lost_bytes;
if (m) {
struct timespec ts;
log.u_bbr.flex3 = m->m_flags;
if (m->m_flags & M_TSTMP) {
mbuf_tstmp2timespec(m, &ts);
tv.tv_sec = ts.tv_sec;
tv.tv_usec = ts.tv_nsec / 1000;
log.u_bbr.lt_epoch = tcp_tv_to_usectick(&tv);
} else {
log.u_bbr.lt_epoch = 0;
}
if (m->m_flags & M_TSTMP_LRO) {
tv.tv_sec = m->m_pkthdr.rcv_tstmp / 1000000000;
tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000) / 1000;
log.u_bbr.flex5 = tcp_tv_to_usectick(&tv);
} else {
/* No arrival timestamp */
log.u_bbr.flex5 = 0;
}
log.u_bbr.pkts_out = tcp_get_usecs(&tv);
} else {
log.u_bbr.flex3 = 0;
log.u_bbr.flex5 = 0;
log.u_bbr.flex6 = 0;
log.u_bbr.pkts_out = 0;
}
log.u_bbr.flex4 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex7 = bbr->r_wanted_output;
log.u_bbr.flex8 = bbr->rc_in_persist;
TCP_LOG_EVENTP(bbr->rc_tp, th,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
TCP_LOG_IN, 0,
tlen, &log, true, &bbr->rc_tv);
}
}
static void
bbr_log_doseg_done(struct tcp_bbr *bbr, uint32_t cts, int32_t nxt_pkt, int32_t did_out)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = did_out;
log.u_bbr.flex2 = nxt_pkt;
log.u_bbr.flex3 = bbr->r_ctl.rc_last_delay_val;
log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
log.u_bbr.flex5 = bbr->r_ctl.rc_timer_exp;
log.u_bbr.flex6 = bbr->r_ctl.rc_lost_bytes;
log.u_bbr.flex7 = bbr->r_wanted_output;
log.u_bbr.flex8 = bbr->rc_in_persist;
log.u_bbr.pkts_out = bbr->r_ctl.highest_hdwr_delay;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_DOSEG_DONE, 0,
0, &log, true, &bbr->rc_tv);
}
}
static void
bbr_log_enobuf_jmp(struct tcp_bbr *bbr, uint32_t len, uint32_t cts,
int32_t line, uint32_t o_len, uint32_t segcnt, uint32_t segsiz)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = o_len;
log.u_bbr.flex3 = segcnt;
log.u_bbr.flex4 = segsiz;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_ENOBUF_JMP, ENOBUFS,
len, &log, true, &bbr->rc_tv);
}
}
static void
bbr_log_to_processing(struct tcp_bbr *bbr, uint32_t cts, int32_t ret, int32_t timers, uint8_t hpts_calling)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = timers;
log.u_bbr.flex2 = ret;
log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
log.u_bbr.flex5 = cts;
log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex8 = hpts_calling;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TO_PROCESS, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_to_event(struct tcp_bbr *bbr, uint32_t cts, int32_t to_num)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
uint64_t ar;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->bbr_timer_src;
log.u_bbr.flex2 = 0;
log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
ar = (uint64_t)(bbr->r_ctl.rc_resend);
ar >>= 32;
ar &= 0x00000000ffffffff;
log.u_bbr.flex4 = (uint32_t)ar;
ar = (uint64_t)bbr->r_ctl.rc_resend;
ar &= 0x00000000ffffffff;
log.u_bbr.flex5 = (uint32_t)ar;
log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
log.u_bbr.flex8 = to_num;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_RTO, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_startup_event(struct tcp_bbr *bbr, uint32_t cts, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint8_t reason)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = flex1;
log.u_bbr.flex2 = flex2;
log.u_bbr.flex3 = flex3;
log.u_bbr.flex4 = 0;
log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
log.u_bbr.flex8 = reason;
log.u_bbr.cur_del_rate = bbr->r_ctl.rc_bbr_lastbtlbw;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_REDUCE, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = diag->p_nxt_slot;
log.u_bbr.flex2 = diag->p_cur_slot;
log.u_bbr.flex3 = diag->slot_req;
log.u_bbr.flex4 = diag->inp_hptsslot;
log.u_bbr.flex5 = diag->slot_remaining;
log.u_bbr.flex6 = diag->need_new_to;
log.u_bbr.flex7 = diag->p_hpts_active;
log.u_bbr.flex8 = diag->p_on_min_sleep;
/* Hijack other fields as needed */
log.u_bbr.epoch = diag->have_slept;
log.u_bbr.lt_epoch = diag->yet_to_sleep;
log.u_bbr.pkts_out = diag->co_ret;
log.u_bbr.applimited = diag->hpts_sleep_time;
log.u_bbr.delivered = diag->p_prev_slot;
log.u_bbr.inflight = diag->p_runningtick;
log.u_bbr.bw_inuse = diag->wheel_tick;
log.u_bbr.rttProp = diag->wheel_cts;
log.u_bbr.delRate = diag->maxticks;
log.u_bbr.cur_del_rate = diag->p_curtick;
log.u_bbr.cur_del_rate <<= 32;
log.u_bbr.cur_del_rate |= diag->p_lasttick;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSDIAG, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
uint32_t thresh, uint32_t to)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->rc_tp->t_rttvar;
log.u_bbr.flex2 = time_since_sent;
log.u_bbr.flex3 = srtt;
log.u_bbr.flex4 = thresh;
log.u_bbr.flex5 = to;
log.u_bbr.flex6 = bbr->rc_tp->t_srtt;
log.u_bbr.flex8 = mode;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERPREP, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = usecs;
log.u_bbr.flex2 = len;
log.u_bbr.flex3 = (uint32_t)((bw >> 32) & 0x00000000ffffffff);
log.u_bbr.flex4 = (uint32_t)(bw & 0x00000000ffffffff);
if (override)
log.u_bbr.flex5 = (1 << 2);
else
log.u_bbr.flex5 = 0;
log.u_bbr.flex6 = override;
log.u_bbr.flex7 = gain;
log.u_bbr.flex8 = mod;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSI_CALC, 0,
len, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->bbr_timer_src;
log.u_bbr.flex2 = to;
log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = slot;
log.u_bbr.flex5 = bbr->rc_inp->inp_hptsslot;
log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
log.u_bbr.pkts_out = bbr->rc_inp->inp_flags2;
log.u_bbr.flex8 = which;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERSTAR, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_thresh_choice(struct tcp_bbr *bbr, uint32_t cts, uint32_t thresh, uint32_t lro, uint32_t srtt, struct bbr_sendmap *rsm, uint8_t frm)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = thresh;
log.u_bbr.flex2 = lro;
log.u_bbr.flex3 = bbr->r_ctl.rc_reorder_ts;
log.u_bbr.flex4 = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
log.u_bbr.flex5 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
log.u_bbr.flex6 = srtt;
log.u_bbr.flex7 = bbr->r_ctl.rc_reorder_shift;
log.u_bbr.flex8 = frm;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_THRESH_CALC, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_to_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts, uint8_t hpts_removed)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = bbr->bbr_timer_src;
log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = bbr->rc_in_persist;
log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
log.u_bbr.flex8 = hpts_removed;
log.u_bbr.pkts_out = bbr->rc_pacer_started;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERCANC, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_tstmp_validation(struct tcp_bbr *bbr, uint64_t peer_delta, uint64_t delta)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
log.u_bbr.flex1 = bbr->r_ctl.bbr_peer_tsratio;
log.u_bbr.flex2 = (peer_delta >> 32);
log.u_bbr.flex3 = (peer_delta & 0x00000000ffffffff);
log.u_bbr.flex4 = (delta >> 32);
log.u_bbr.flex5 = (delta & 0x00000000ffffffff);
log.u_bbr.flex7 = bbr->rc_ts_clock_set;
log.u_bbr.flex8 = bbr->rc_ts_cant_be_used;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_TSTMP_VAL, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_tsosize(struct tcp_bbr *bbr, uint32_t cts, uint32_t tsosz, uint32_t tls, uint32_t old_val, uint32_t maxseg, int hdwr)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = tsosz;
log.u_bbr.flex2 = tls;
log.u_bbr.flex3 = tcp_min_hptsi_time;
log.u_bbr.flex4 = bbr->r_ctl.bbr_hptsi_bytes_min;
log.u_bbr.flex5 = old_val;
log.u_bbr.flex6 = maxseg;
log.u_bbr.flex7 = bbr->rc_no_pacing;
log.u_bbr.flex7 <<= 1;
log.u_bbr.flex7 |= bbr->rc_past_init_win;
if (hdwr)
log.u_bbr.flex8 = 0x80 | bbr->rc_use_google;
else
log.u_bbr.flex8 = bbr->rc_use_google;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRTSO, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_rsmclear(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm,
uint32_t flags, uint32_t line)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = rsm->r_start;
log.u_bbr.flex3 = rsm->r_end;
log.u_bbr.flex4 = rsm->r_delivered;
log.u_bbr.flex5 = rsm->r_rtr_cnt;
log.u_bbr.flex6 = rsm->r_dupack;
log.u_bbr.flex7 = rsm->r_tim_lastsent[0];
log.u_bbr.flex8 = rsm->r_flags;
/* Hijack the pkts_out fids */
log.u_bbr.applimited = flags;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_RSM_CLEARED, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_bbrupd(struct tcp_bbr *bbr, uint8_t flex8, uint32_t cts,
uint32_t flex3, uint32_t flex2, uint32_t flex5,
uint32_t flex6, uint32_t pkts_out, int flex7,
uint32_t flex4, uint32_t flex1)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = flex1;
log.u_bbr.flex2 = flex2;
log.u_bbr.flex3 = flex3;
log.u_bbr.flex4 = flex4;
log.u_bbr.flex5 = flex5;
log.u_bbr.flex6 = flex6;
log.u_bbr.flex7 = flex7;
/* Hijack the pkts_out fids */
log.u_bbr.pkts_out = pkts_out;
log.u_bbr.flex8 = flex8;
if (bbr->rc_ack_was_delayed)
log.u_bbr.epoch = bbr->r_ctl.rc_ack_hdwr_delay;
else
log.u_bbr.epoch = 0;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRUPD, 0,
flex2, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_ltbw(struct tcp_bbr *bbr, uint32_t cts, int32_t reason,
uint32_t newbw, uint32_t obw, uint32_t diff,
uint32_t tim)
{
if (/*bbr_verbose_logging && */(bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = reason;
log.u_bbr.flex2 = newbw;
log.u_bbr.flex3 = obw;
log.u_bbr.flex4 = diff;
log.u_bbr.flex5 = bbr->r_ctl.rc_lt_lost;
log.u_bbr.flex6 = bbr->r_ctl.rc_lt_del;
log.u_bbr.flex7 = bbr->rc_lt_is_sampling;
log.u_bbr.pkts_out = tim;
log.u_bbr.bw_inuse = bbr->r_ctl.rc_lt_bw;
if (bbr->rc_lt_use_bw == 0)
log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
else
log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BWSAMP, 0,
0, &log, false, &bbr->rc_tv);
}
}
static inline void
bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
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_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_PROGRESS, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_type_log_hdwr_pacing(struct tcp_bbr *bbr, const struct ifnet *ifp,
uint64_t rate, uint64_t hw_rate, int line, uint32_t cts,
int error)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
log.u_bbr.flex3 = (((uint64_t)ifp >> 32) & 0x00000000ffffffff);
log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
log.u_bbr.bw_inuse = rate;
log.u_bbr.flex5 = line;
log.u_bbr.flex6 = error;
log.u_bbr.flex8 = bbr->skip_gain;
log.u_bbr.flex8 <<= 1;
log.u_bbr.flex8 |= bbr->gain_is_limited;
log.u_bbr.flex8 <<= 1;
log.u_bbr.flex8 |= bbr->bbr_hdrw_pacing;
log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_HDWR_PACE, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot, uint32_t del_by, uint32_t cts, uint32_t line, uint32_t prev_delay)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = slot;
log.u_bbr.flex2 = del_by;
log.u_bbr.flex3 = prev_delay;
log.u_bbr.flex4 = line;
log.u_bbr.flex5 = bbr->r_ctl.rc_last_delay_val;
log.u_bbr.flex6 = bbr->r_ctl.rc_hptsi_agg_delay;
log.u_bbr.flex7 = (0x0000ffff & bbr->r_ctl.rc_hpts_flags);
log.u_bbr.flex8 = bbr->rc_in_persist;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRSND, 0,
len, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_type_bbrrttprop(struct tcp_bbr *bbr, uint32_t t, uint32_t end, uint32_t tsconv, uint32_t cts, int32_t match, uint32_t seq, uint8_t flags)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->r_ctl.rc_delivered;
log.u_bbr.flex2 = 0;
log.u_bbr.flex3 = bbr->r_ctl.rc_lowest_rtt;
log.u_bbr.flex4 = end;
log.u_bbr.flex5 = seq;
log.u_bbr.flex6 = t;
log.u_bbr.flex7 = match;
log.u_bbr.flex8 = flags;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRRTT, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_exit_gain(struct tcp_bbr *bbr, uint32_t cts, int32_t entry_method)
{
if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
log.u_bbr.flex2 = (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
log.u_bbr.flex3 = bbr->r_ctl.gain_epoch;
log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
log.u_bbr.flex5 = bbr->r_ctl.rc_pace_min_segs;
log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_state_atflight;
log.u_bbr.flex7 = 0;
log.u_bbr.flex8 = entry_method;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_EXIT_GAIN, 0,
0, &log, false, &bbr->rc_tv);
}
}
static void
bbr_log_settings_change(struct tcp_bbr *bbr, int settings_desired)
{
if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
/* R-HU */
log.u_bbr.flex1 = 0;
log.u_bbr.flex2 = 0;
log.u_bbr.flex3 = 0;
log.u_bbr.flex4 = 0;
log.u_bbr.flex7 = 0;
log.u_bbr.flex8 = settings_desired;
TCP_LOG_EVENTP(bbr->rc_tp, NULL,
&bbr->rc_inp->inp_socket->so_rcv,
&bbr->rc_inp->inp_socket->so_snd,
BBR_LOG_SETTINGS_CHG, 0,
0, &log, false, &bbr->rc_tv);
}
}
/*
* Returns the bw from the our filter.
*/
static inline uint64_t
bbr_get_full_bw(struct tcp_bbr *bbr)
{
uint64_t bw;
bw = get_filter_value(&bbr->r_ctl.rc_delrate);
return (bw);
}
static inline void
bbr_set_pktepoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
uint64_t calclr;
uint32_t lost, del;
if (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_pktepoch)
lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lost_at_pktepoch;
else
lost = 0;
del = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_pkt_epoch_del;
if (lost == 0) {
calclr = 0;
} else if (del) {
calclr = lost;
calclr *= (uint64_t)1000;
calclr /= (uint64_t)del;
} else {
/* Nothing delivered? 100.0% loss */
calclr = 1000;
}
bbr->r_ctl.rc_pkt_epoch_loss_rate = (uint32_t)calclr;
if (IN_RECOVERY(bbr->rc_tp->t_flags))
bbr->r_ctl.recovery_lr += (uint32_t)calclr;
bbr->r_ctl.rc_pkt_epoch++;
if (bbr->rc_no_pacing &&
(bbr->r_ctl.rc_pkt_epoch >= bbr->no_pacing_until)) {
bbr->rc_no_pacing = 0;
tcp_bbr_tso_size_check(bbr, cts);
}
bbr->r_ctl.rc_pkt_epoch_rtt = bbr_calc_time(cts, bbr->r_ctl.rc_pkt_epoch_time);
bbr->r_ctl.rc_pkt_epoch_time = cts;
/* What was our loss rate */
bbr_log_pkt_epoch(bbr, cts, line, lost, del);
bbr->r_ctl.rc_pkt_epoch_del = bbr->r_ctl.rc_delivered;
bbr->r_ctl.rc_lost_at_pktepoch = bbr->r_ctl.rc_lost;
}
static inline void
bbr_set_epoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
uint32_t epoch_time;
/* Tick the RTT clock */
bbr->r_ctl.rc_rtt_epoch++;
epoch_time = cts - bbr->r_ctl.rc_rcv_epoch_start;
bbr_log_time_epoch(bbr, cts, line, epoch_time);
bbr->r_ctl.rc_rcv_epoch_start = cts;
}
static inline void
bbr_isit_a_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm, int32_t line, int32_t cum_acked)
{
if (SEQ_GEQ(rsm->r_delivered, bbr->r_ctl.rc_pkt_epoch_del)) {
bbr->rc_is_pkt_epoch_now = 1;
}
}
/*
* Returns the bw from either the b/w filter
* or from the lt_bw (if the connection is being
* policed).
*/
static inline uint64_t
__bbr_get_bw(struct tcp_bbr *bbr)
{
uint64_t bw, min_bw;
uint64_t rtt;
int gm_measure_cnt = 1;
/*
* For startup we make, like google, a
* minimum b/w. This is generated from the
* IW and the rttProp. We do fall back to srtt
* if for some reason (initial handshake) we don't
* have a rttProp. We, in the worst case, fall back
* to the configured min_bw (rc_initial_hptsi_bw).
*/
if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
/* Attempt first to use rttProp */
rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
if (rtt && (rtt < 0xffffffff)) {
measure:
min_bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
((uint64_t)1000000);
min_bw /= rtt;
if (min_bw < bbr->r_ctl.rc_initial_hptsi_bw) {
min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
}
} else if (bbr->rc_tp->t_srtt != 0) {
/* No rttProp, use srtt? */
rtt = bbr_get_rtt(bbr, BBR_SRTT);
goto measure;
} else {
min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
}
} else
min_bw = 0;
if ((bbr->rc_past_init_win == 0) &&
(bbr->r_ctl.rc_delivered > bbr_initial_cwnd(bbr, bbr->rc_tp)))
bbr->rc_past_init_win = 1;
if ((bbr->rc_use_google) && (bbr->r_ctl.r_measurement_count >= 1))
gm_measure_cnt = 0;
if (gm_measure_cnt &&
((bbr->r_ctl.r_measurement_count < bbr_min_measurements_req) ||
(bbr->rc_past_init_win == 0))) {
/* For google we use our guess rate until we get 1 measurement */
use_initial_window:
rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
if (rtt && (rtt < 0xffffffff)) {
/*
* We have an RTT measurment. Use that in
* combination with our initial window to calculate
* a b/w.
*/
bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
((uint64_t)1000000);
bw /= rtt;
if (bw < bbr->r_ctl.rc_initial_hptsi_bw) {
bw = bbr->r_ctl.rc_initial_hptsi_bw;
}
} else {
/* Drop back to the 40 and punt to a default */
bw = bbr->r_ctl.rc_initial_hptsi_bw;
}
if (bw < 1)
/* Probably should panic */
bw = 1;
if (bw > min_bw)
return (bw);
else
return (min_bw);
}
if (bbr->rc_lt_use_bw)
bw = bbr->r_ctl.rc_lt_bw;
else if (bbr->r_recovery_bw && (bbr->rc_use_google == 0))
bw = bbr->r_ctl.red_bw;
else
bw = get_filter_value(&bbr->r_ctl.rc_delrate);
if (bbr->rc_tp->t_peakrate_thr && (bbr->rc_use_google == 0)) {
/*
* Enforce user set rate limit, keep in mind that
* t_peakrate_thr is in B/s already
*/
bw = uqmin((uint64_t)bbr->rc_tp->t_peakrate_thr, bw);
}
if (bw == 0) {
/* We should not be at 0, go to the initial window then */
goto use_initial_window;
}
if (bw < 1)
/* Probably should panic */
bw = 1;
if (bw < min_bw)
bw = min_bw;
return (bw);
}
static inline uint64_t
bbr_get_bw(struct tcp_bbr *bbr)
{
uint64_t bw;
bw = __bbr_get_bw(bbr);
return (bw);
}
static inline void
bbr_reset_lt_bw_interval(struct tcp_bbr *bbr, uint32_t cts)
{
bbr->r_ctl.rc_lt_epoch = bbr->r_ctl.rc_pkt_epoch;
bbr->r_ctl.rc_lt_time = bbr->r_ctl.rc_del_time;
bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
static inline void
bbr_reset_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts)
{
bbr->rc_lt_is_sampling = 0;
bbr->rc_lt_use_bw = 0;
bbr->r_ctl.rc_lt_bw = 0;
bbr_reset_lt_bw_interval(bbr, cts);
}
static inline void
bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t timin)
{
uint64_t diff;
/* Do we have a previous sample? */
if (bbr->r_ctl.rc_lt_bw) {
/* Get the diff in bytes per second */
if (bbr->r_ctl.rc_lt_bw > bw)
diff = bbr->r_ctl.rc_lt_bw - bw;
else
diff = bw - bbr->r_ctl.rc_lt_bw;
if ((diff <= bbr_lt_bw_diff) ||
(diff <= (bbr->r_ctl.rc_lt_bw / bbr_lt_bw_ratio))) {
/* Consider us policed */
uint32_t saved_bw;
saved_bw = (uint32_t)bbr->r_ctl.rc_lt_bw;
bbr->r_ctl.rc_lt_bw = (bw + bbr->r_ctl.rc_lt_bw) / 2; /* average of two */
bbr->rc_lt_use_bw = 1;
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
/*
* Use pkt based epoch for measuring length of
* policer up
*/
bbr->r_ctl.rc_lt_epoch_use = bbr->r_ctl.rc_pkt_epoch;
/*
* reason 4 is we need to start consider being
* policed
*/
bbr_log_type_ltbw(bbr, cts, 4, (uint32_t)bw, saved_bw, (uint32_t)diff, timin);
return;
}
}
bbr->r_ctl.rc_lt_bw = bw;
bbr_reset_lt_bw_interval(bbr, cts);
bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
}
/*
* RRS: Copied from user space!
* Calculate a uniformly distributed random number less than upper_bound
* avoiding "modulo bias".
*
* Uniformity is achieved by generating new random numbers until the one
* returned is outside the range [0, 2**32 % upper_bound). This
* guarantees the selected random number will be inside
* [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
* after reduction modulo upper_bound.
*/
static uint32_t
arc4random_uniform(uint32_t upper_bound)
{
uint32_t r, min;
if (upper_bound < 2)
return 0;
/* 2**32 % x == (2**32 - x) % x */
min = -upper_bound % upper_bound;
/*
* This could theoretically loop forever but each retry has
* p > 0.5 (worst case, usually far better) of selecting a
* number inside the range we need, so it should rarely need
* to re-roll.
*/
for (;;) {
r = arc4random();
if (r >= min)
break;
}
return r % upper_bound;
}
static void
bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
{
uint32_t ran, deduct;
ran = arc4random_uniform(bbr_rand_ot);
if (ran) {
deduct = bbr->r_ctl.rc_level_state_extra / ran;
bbr->r_ctl.rc_level_state_extra -= deduct;
}
}
/*
* Return randomly the starting state
* to use in probebw.
*/
static uint8_t
bbr_pick_probebw_substate(struct tcp_bbr *bbr, uint32_t cts)
{
uint32_t ran;
uint8_t ret_val;
/* Initialize the offset to 0 */
bbr->r_ctl.rc_exta_time_gd = 0;
bbr->rc_hit_state_1 = 0;
bbr->r_ctl.rc_level_state_extra = 0;
ran = arc4random_uniform((BBR_SUBSTATE_COUNT-1));
/*
* The math works funny here :) the return value is used to set the
* substate and then the state change is called which increments by
* one. So if we return 1 (DRAIN) we will increment to 2 (LEVEL1) when
* we fully enter the state. Note that the (8 - 1 - ran) assures that
* we return 1 - 7, so we dont return 0 and end up starting in
* state 1 (DRAIN).
*/
ret_val = BBR_SUBSTATE_COUNT - 1 - ran;
/* Set an epoch */
if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP))
bbr_set_epoch(bbr, cts, __LINE__);
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
return (ret_val);
}
static void
bbr_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts, int32_t loss_detected)
{
uint32_t diff, d_time;
uint64_t del_time, bw, lost, delivered;
if (bbr->r_use_policer == 0)
return;
if (bbr->rc_lt_use_bw) {
/* We are using lt bw do we stop yet? */
diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
if (diff > bbr_lt_bw_max_rtts) {
/* Reset it all */
reset_all:
bbr_reset_lt_bw_sampling(bbr, cts);
if (bbr->rc_filled_pipe) {
bbr_set_epoch(bbr, cts, __LINE__);
bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
bbr_substate_change(bbr, cts, __LINE__, 0);
bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
bbr_log_type_statechange(bbr, cts, __LINE__);
} else {
/*
* This should not happen really
* unless we remove the startup/drain
* restrictions above.
*/
bbr->rc_bbr_state = BBR_STATE_STARTUP;
bbr_set_epoch(bbr, cts, __LINE__);
bbr->r_ctl.rc_bbr_state_time = cts;
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
bbr_set_state_target(bbr, __LINE__);
bbr_log_type_statechange(bbr, cts, __LINE__);
}
/* reason 0 is to stop using lt-bw */
bbr_log_type_ltbw(bbr, cts, 0, 0, 0, 0, 0);
return;
}
if (bbr_lt_intvl_fp == 0) {
/* Not doing false-postive detection */
return;
}
/* False positive detection */
if (diff == bbr_lt_intvl_fp) {
/* At bbr_lt_intvl_fp we record the lost */
bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
} else if (diff > (bbr_lt_intvl_min_rtts + bbr_lt_intvl_fp)) {
/* Now is our loss rate still high? */
lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
if ((delivered == 0) ||
(((lost * 1000)/delivered) < bbr_lt_fd_thresh)) {
/* No still below our threshold */
bbr_log_type_ltbw(bbr, cts, 7, lost, delivered, 0, 0);
} else {
/* Yikes its still high, it must be a false positive */
bbr_log_type_ltbw(bbr, cts, 8, lost, delivered, 0, 0);
goto reset_all;
}
}
return;
}
/*
* Wait for the first loss before sampling, to let the policer
* exhaust its tokens and estimate the steady-state rate allowed by
* the policer. Starting samples earlier includes bursts that
* over-estimate the bw.
*/
if (bbr->rc_lt_is_sampling == 0) {
/* reason 1 is to begin doing the sampling */
if (loss_detected == 0)
return;
bbr_reset_lt_bw_interval(bbr, cts);
bbr->rc_lt_is_sampling = 1;
bbr_log_type_ltbw(bbr, cts, 1, 0, 0, 0, 0);
return;
}
/* Now how long were we delivering long term last> */
if (TSTMP_GEQ(bbr->r_ctl.rc_del_time, bbr->r_ctl.rc_lt_time))
d_time = bbr->r_ctl.rc_del_time - bbr->r_ctl.rc_lt_time;
else
d_time = 0;
/* To avoid underestimates, reset sampling if we run out of data. */
if (bbr->r_ctl.r_app_limited_until) {
/* Can not measure in app-limited state */
bbr_reset_lt_bw_sampling(bbr, cts);
/* reason 2 is to reset sampling due to app limits */
bbr_log_type_ltbw(bbr, cts, 2, 0, 0, 0, d_time);
return;
}
diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
if (diff < bbr_lt_intvl_min_rtts) {
/*
* need more samples (we don't
* start on a round like linux so
* we need 1 more).
*/
/* 6 is not_enough time or no-loss */
bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
return;
}
if (diff > (4 * bbr_lt_intvl_min_rtts)) {
/*
* For now if we wait too long, reset all sampling. We need
* to do some research here, its possible that we should
* base this on how much loss as occurred.. something like
* if its under 10% (or some thresh) reset all otherwise
* don't. Thats for phase II I guess.
*/
bbr_reset_lt_bw_sampling(bbr, cts);
/* reason 3 is to reset sampling due too long of sampling */
bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
return;
}
/*
* End sampling interval when a packet is lost, so we estimate the
* policer tokens were exhausted. Stopping the sampling before the
* tokens are exhausted under-estimates the policed rate.
*/
if (loss_detected == 0) {
/* 6 is not_enough time or no-loss */
bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
return;
}
/* Calculate packets lost and delivered in sampling interval. */
lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
if ((delivered == 0) ||
(((lost * 1000)/delivered) < bbr_lt_loss_thresh)) {
bbr_log_type_ltbw(bbr, cts, 6, lost, delivered, 0, d_time);
return;
}
if (d_time < 1000) {
/* Not enough time. wait */
/* 6 is not_enough time or no-loss */
bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
return;
}
if (d_time >= (0xffffffff / USECS_IN_MSEC)) {
/* Too long */
bbr_reset_lt_bw_sampling(bbr, cts);
/* reason 3 is to reset sampling due too long of sampling */
bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
return;
}
del_time = d_time;
bw = delivered;
bw *= (uint64_t)USECS_IN_SECOND;
bw /= del_time;
bbr_lt_bw_samp_done(bbr, bw, cts, d_time);
}
/*
* Allocate a sendmap from our zone.
*/
static struct bbr_sendmap *
bbr_alloc(struct tcp_bbr *bbr)
{
struct bbr_sendmap *rsm;
BBR_STAT_INC(bbr_to_alloc);
rsm = uma_zalloc(bbr_zone, (M_NOWAIT | M_ZERO));
if (rsm) {
bbr->r_ctl.rc_num_maps_alloced++;
return (rsm);
}
if (bbr->r_ctl.rc_free_cnt) {
BBR_STAT_INC(bbr_to_alloc_emerg);
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
bbr->r_ctl.rc_free_cnt--;
return (rsm);
}
BBR_STAT_INC(bbr_to_alloc_failed);
return (NULL);
}
static struct bbr_sendmap *
bbr_alloc_full_limit(struct tcp_bbr *bbr)
{
if ((bbr_tcp_map_entries_limit > 0) &&
(bbr->r_ctl.rc_num_maps_alloced >= bbr_tcp_map_entries_limit)) {
BBR_STAT_INC(bbr_alloc_limited);
if (!bbr->alloc_limit_reported) {
bbr->alloc_limit_reported = 1;
BBR_STAT_INC(bbr_alloc_limited_conns);
}
return (NULL);
}
return (bbr_alloc(bbr));
}
/* wrapper to allocate a sendmap entry, subject to a specific limit */
static struct bbr_sendmap *
bbr_alloc_limit(struct tcp_bbr *bbr, uint8_t limit_type)
{
struct bbr_sendmap *rsm;
if (limit_type) {
/* currently there is only one limit type */
if (bbr_tcp_map_split_limit > 0 &&
bbr->r_ctl.rc_num_split_allocs >= bbr_tcp_map_split_limit) {
BBR_STAT_INC(bbr_split_limited);
if (!bbr->alloc_limit_reported) {
bbr->alloc_limit_reported = 1;
BBR_STAT_INC(bbr_alloc_limited_conns);
}
return (NULL);
}
}
/* allocate and mark in the limit type, if set */
rsm = bbr_alloc(bbr);
if (rsm != NULL && limit_type) {
rsm->r_limit_type = limit_type;
bbr->r_ctl.rc_num_split_allocs++;
}
return (rsm);
}
static void
bbr_free(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
{
if (rsm->r_limit_type) {
/* currently there is only one limit type */
bbr->r_ctl.rc_num_split_allocs--;
}
if (rsm->r_is_smallmap)
bbr->r_ctl.rc_num_small_maps_alloced--;
if (bbr->r_ctl.rc_tlp_send == rsm)
bbr->r_ctl.rc_tlp_send = NULL;
if (bbr->r_ctl.rc_resend == rsm) {
bbr->r_ctl.rc_resend = NULL;
}
if (bbr->r_ctl.rc_next == rsm)
bbr->r_ctl.rc_next = NULL;
if (bbr->r_ctl.rc_sacklast == rsm)
bbr->r_ctl.rc_sacklast = NULL;
if (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
memset(rsm, 0, sizeof(struct bbr_sendmap));
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
rsm->r_limit_type = 0;
bbr->r_ctl.rc_free_cnt++;
return;
}
bbr->r_ctl.rc_num_maps_alloced--;
uma_zfree(bbr_zone, rsm);
}
/*
* Returns the BDP.
*/
static uint64_t
bbr_get_bw_delay_prod(uint64_t rtt, uint64_t bw) {
/*
* Calculate the bytes in flight needed given the bw (in bytes per
* second) and the specifyed rtt in useconds. We need to put out the
* returned value per RTT to match that rate. Gain will normaly
* raise it up from there.
*
* This should not overflow as long as the bandwidth is below 1
* TByte per second (bw < 10**12 = 2**40) and the rtt is smaller
* than 1000 seconds (rtt < 10**3 * 10**6 = 10**9 = 2**30).
*/
uint64_t usec_per_sec;
usec_per_sec = USECS_IN_SECOND;
return ((rtt * bw) / usec_per_sec);
}
/*
* Return the initial cwnd.
*/
static uint32_t
bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp)
{
uint32_t i_cwnd;
if (bbr->rc_init_win) {
i_cwnd = bbr->rc_init_win * tp->t_maxseg;
} else if (V_tcp_initcwnd_segments)
i_cwnd = min((V_tcp_initcwnd_segments * tp->t_maxseg),
max(2 * tp->t_maxseg, 14600));
else if (V_tcp_do_rfc3390)
i_cwnd = min(4 * tp->t_maxseg,
max(2 * tp->t_maxseg, 4380));
else {
/* Per RFC5681 Section 3.1 */
if (tp->t_maxseg > 2190)
i_cwnd = 2 * tp->t_maxseg;
else if (tp->t_maxseg > 1095)
i_cwnd = 3 * tp->t_maxseg;
else
i_cwnd = 4 * tp->t_maxseg;
}
return (i_cwnd);
}
/*
* Given a specified gain, return the target
* cwnd based on that gain.
*/
static uint32_t
bbr_get_raw_target_cwnd(struct tcp_bbr *bbr, uint32_t gain, uint64_t bw)
{
uint64_t bdp, rtt;
uint32_t cwnd;
if ((get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) ||
(bbr_get_full_bw(bbr) == 0)) {
/* No measurements yet */
return (bbr_initial_cwnd(bbr, bbr->rc_tp));
}
/*
* Get bytes per RTT needed (rttProp is normally in
* bbr_cwndtarget_rtt_touse)
*/
rtt = bbr_get_rtt(bbr, bbr_cwndtarget_rtt_touse);
/* Get the bdp from the two values */
bdp = bbr_get_bw_delay_prod(rtt, bw);
/* Now apply the gain */
cwnd = (uint32_t)(((bdp * ((uint64_t)gain)) + (uint64_t)(BBR_UNIT - 1)) / ((uint64_t)BBR_UNIT));
return (cwnd);
}
static uint32_t
bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain)
{
uint32_t cwnd, mss;
mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
/* Get the base cwnd with gain rounded to a mss */
cwnd = roundup(bbr_get_raw_target_cwnd(bbr, bw, gain), mss);
/*
* Add in N (2 default since we do not have a
* fq layer to trap packets in) quanta's per the I-D
* section 4.2.3.2 quanta adjust.
*/
cwnd += (bbr_quanta * bbr->r_ctl.rc_pace_max_segs);
if (bbr->rc_use_google) {
if((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
(bbr_state_val(bbr) == BBR_SUB_GAIN)) {
/*
* The linux implementation adds
* an extra 2 x mss in gain cycle which
* is documented no-where except in the code.
* so we add more for Neal undocumented feature
*/
cwnd += 2 * mss;
}
if ((cwnd / mss) & 0x1) {
/* Round up for odd num mss */
cwnd += mss;
}
}
/* Are we below the min cwnd? */
if (cwnd < get_min_cwnd(bbr))
return (get_min_cwnd(bbr));
return (cwnd);
}
static uint16_t
bbr_gain_adjust(struct tcp_bbr *bbr, uint16_t gain)
{
if (gain < 1)
gain = 1;
return (gain);
}
static uint32_t
bbr_get_header_oh(struct tcp_bbr *bbr)
{
int seg_oh;
seg_oh = 0;
if (bbr->r_ctl.rc_inc_tcp_oh) {
/* Do we include TCP overhead? */
seg_oh = (bbr->rc_last_options + sizeof(struct tcphdr));
}
if (bbr->r_ctl.rc_inc_ip_oh) {
/* Do we include IP overhead? */
#ifdef INET6
if (bbr->r_is_v6)
seg_oh += sizeof(struct ip6_hdr);
else
#endif
#ifdef INET
seg_oh += sizeof(struct ip);
#endif
}
if (bbr->r_ctl.rc_inc_enet_oh) {
/* Do we include the ethernet overhead? */
seg_oh += sizeof(struct ether_header);
}
return(seg_oh);
}
static uint32_t
bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain, uint32_t useconds_time, uint64_t bw)
{
uint64_t divor, res, tim;
if (useconds_time == 0)
return (0);
gain = bbr_gain_adjust(bbr, gain);
divor = (uint64_t)USECS_IN_SECOND * (uint64_t)BBR_UNIT;
tim = useconds_time;
res = (tim * bw * gain) / divor;
if (res == 0)
res = 1;
return ((uint32_t)res);
}
/*
* Given a gain and a length return the delay in useconds that
* should be used to evenly space out packets
* on the connection (based on the gain factor).
*/
static uint32_t
bbr_get_pacing_delay(struct tcp_bbr *bbr, uint16_t gain, int32_t len, uint32_t cts, int nolog)
{
uint64_t bw, lentim, res;
uint32_t usecs, srtt, over = 0;
uint32_t seg_oh, num_segs, maxseg;
if (len == 0)
return (0);
maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
num_segs = (len + maxseg - 1) / maxseg;
if (bbr->rc_use_google == 0) {
seg_oh = bbr_get_header_oh(bbr);
len += (num_segs * seg_oh);
}
gain = bbr_gain_adjust(bbr, gain);
bw = bbr_get_bw(bbr);
if (bbr->rc_use_google) {
uint64_t cbw;
/*
* Reduce the b/w by the google discount
* factor 10 = 1%.
*/
cbw = bw * (uint64_t)(1000 - bbr->r_ctl.bbr_google_discount);
cbw /= (uint64_t)1000;
/* We don't apply a discount if it results in 0 */
if (cbw > 0)
bw = cbw;
}
lentim = ((uint64_t)len *
(uint64_t)USECS_IN_SECOND *
(uint64_t)BBR_UNIT);
res = lentim / ((uint64_t)gain * bw);
if (res == 0)
res = 1;
usecs = (uint32_t)res;
srtt = bbr_get_rtt(bbr, BBR_SRTT);
if (bbr_hptsi_max_mul && bbr_hptsi_max_div &&
(bbr->rc_use_google == 0) &&
(usecs > ((srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div))) {
/*
* We cannot let the delay be more than 1/2 the srtt time.
* Otherwise we cannot pace out or send properly.
*/
over = usecs = (srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div;
BBR_STAT_INC(bbr_hpts_min_time);
}
if (!nolog)
bbr_log_pacing_delay_calc(bbr, gain, len, cts, usecs, bw, over, 1);
return (usecs);
}
static void
bbr_ack_received(struct tcpcb *tp, struct tcp_bbr *bbr, struct tcphdr *th, uint32_t bytes_this_ack,
uint32_t sack_changed, uint32_t prev_acked, int32_t line, uint32_t losses)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
uint64_t bw;
uint32_t cwnd, target_cwnd, saved_bytes, maxseg;
int32_t meth;
#ifdef NETFLIX_STATS
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GEQ(th->th_ack, tp->gput_ack)) {
/*
* Strech acks and compressed acks will cause this to
* oscillate but we are doing it the same way as the main
* stack so it will be compariable (though possibly not
* ideal).
*/
int32_t cgput;
int64_t gput, time_stamp;
gput = (int64_t) (th->th_ack - tp->gput_seq) * 8;
time_stamp = max(1, ((bbr->r_ctl.rc_rcvtime - tp->gput_ts) / 1000));
cgput = gput / time_stamp;
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
cgput);
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 = cgput;
}
#endif
if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
/* We don't change anything in probe-rtt */
return;
}
maxseg = tp->t_maxseg - bbr->rc_last_options;
saved_bytes = bytes_this_ack;
bytes_this_ack += sack_changed;
if (bytes_this_ack > prev_acked) {
bytes_this_ack -= prev_acked;
/*
* A byte ack'd gives us a full mss
* to be like linux i.e. they count packets.
*/
if ((bytes_this_ack < maxseg) && bbr->rc_use_google)
bytes_this_ack = maxseg;
} else {
/* Unlikely */
bytes_this_ack = 0;
}
cwnd = tp->snd_cwnd;
bw = get_filter_value(&bbr->r_ctl.rc_delrate);
if (bw)
target_cwnd = bbr_get_target_cwnd(bbr,
bw,
(uint32_t)bbr->r_ctl.rc_bbr_cwnd_gain);
else
target_cwnd = bbr_initial_cwnd(bbr, bbr->rc_tp);
if (IN_RECOVERY(tp->t_flags) &&
(bbr->bbr_prev_in_rec == 0)) {
/*
* We are entering recovery and
* thus packet conservation.
*/
bbr->pkt_conservation = 1;
bbr->r_ctl.rc_recovery_start = bbr->r_ctl.rc_rcvtime;
cwnd = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
bytes_this_ack;
}
if (IN_RECOVERY(tp->t_flags)) {
uint32_t flight;
bbr->bbr_prev_in_rec = 1;
if (cwnd > losses) {
cwnd -= losses;
if (cwnd < maxseg)
cwnd = maxseg;
} else
cwnd = maxseg;
flight = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
bbr_log_type_cwndupd(bbr, flight, 0,
losses, 10, 0, 0, line);
if (bbr->pkt_conservation) {
uint32_t time_in;
if (TSTMP_GEQ(bbr->r_ctl.rc_rcvtime, bbr->r_ctl.rc_recovery_start))
time_in = bbr->r_ctl.rc_rcvtime - bbr->r_ctl.rc_recovery_start;
else
time_in = 0;
if (time_in >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
/* Clear packet conservation after an rttProp */
bbr->pkt_conservation = 0;
} else {
if ((flight + bytes_this_ack) > cwnd)
cwnd = flight + bytes_this_ack;
if (cwnd < get_min_cwnd(bbr))
cwnd = get_min_cwnd(bbr);
tp->snd_cwnd = cwnd;
bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed,
prev_acked, 1, target_cwnd, th->th_ack, line);
return;
}
}
} else
bbr->bbr_prev_in_rec = 0;
if ((bbr->rc_use_google == 0) && bbr->r_ctl.restrict_growth) {
bbr->r_ctl.restrict_growth--;
if (bytes_this_ack > maxseg)
bytes_this_ack = maxseg;
}
if (bbr->rc_filled_pipe) {
/*
* Here we have exited startup and filled the pipe. We will
* thus allow the cwnd to shrink to the target. We hit here
* mostly.
*/
uint32_t s_cwnd;
meth = 2;
s_cwnd = min((cwnd + bytes_this_ack), target_cwnd);
if (s_cwnd > cwnd)
cwnd = s_cwnd;
else if (bbr_cwnd_may_shrink || bbr->rc_use_google || bbr->rc_no_pacing)
cwnd = s_cwnd;
} else {
/*
* Here we are still in startup, we increase cwnd by what
* has been acked.
*/
if ((cwnd < target_cwnd) ||
(bbr->rc_past_init_win == 0)) {
meth = 3;
cwnd += bytes_this_ack;
} else {
/*
* Method 4 means we are at target so no gain in
* startup and past the initial window.
*/
meth = 4;
}
}
tp->snd_cwnd = max(cwnd, get_min_cwnd(bbr));
bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed, prev_acked, meth, target_cwnd, th->th_ack, line);
}
static void
tcp_bbr_partialack(struct tcpcb *tp)
{
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
tp->snd_cwnd) {
bbr->r_wanted_output = 1;
}
}
static void
bbr_post_recovery(struct tcpcb *tp)
{
struct tcp_bbr *bbr;
uint32_t flight;
INP_WLOCK_ASSERT(tp->t_inpcb);
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
/*
* Here we just exit recovery.
*/
EXIT_RECOVERY(tp->t_flags);
/* Lock in our b/w reduction for the specified number of pkt-epochs */
bbr->r_recovery_bw = 0;
tp->snd_recover = tp->snd_una;
tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
bbr->pkt_conservation = 0;
if (bbr->rc_use_google == 0) {
/*
* For non-google mode lets
* go ahead and make sure we clear
* the recovery state so if we
* bounce back in to recovery we
* will do PC.
*/
bbr->bbr_prev_in_rec = 0;
}
bbr_log_type_exit_rec(bbr);
if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
bbr_log_type_cwndupd(bbr, 0, 0, 0, 15, 0, 0, __LINE__);
} else {
/* For probe-rtt case lets fix up its saved_cwnd */
if (bbr->r_ctl.rc_saved_cwnd < bbr->r_ctl.rc_cwnd_on_ent) {
bbr->r_ctl.rc_saved_cwnd = bbr->r_ctl.rc_cwnd_on_ent;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 16, 0, 0, __LINE__);
}
}
flight = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if ((bbr->rc_use_google == 0) &&
bbr_do_red) {
uint64_t val, lr2use;
uint32_t maxseg, newcwnd, acks_inflight, ratio, cwnd;
uint32_t *cwnd_p;
if (bbr_get_rtt(bbr, BBR_SRTT)) {
val = ((uint64_t)bbr_get_rtt(bbr, BBR_RTT_PROP) * (uint64_t)1000);
val /= bbr_get_rtt(bbr, BBR_SRTT);
ratio = (uint32_t)val;
} else
ratio = 1000;
bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div,
bbr->r_ctl.recovery_lr, 21,
ratio,
bbr->r_ctl.rc_red_cwnd_pe,
__LINE__);
if ((ratio < bbr_do_red) || (bbr_do_red == 0))
goto done;
if (((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
bbr_prtt_slam_cwnd) ||
(bbr_sub_drain_slam_cwnd &&
(bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
bbr->rc_hit_state_1 &&
(bbr_state_val(bbr) == BBR_SUB_DRAIN)) ||
((bbr->rc_bbr_state == BBR_STATE_DRAIN) &&
bbr_slam_cwnd_in_main_drain)) {
/*
* Here we must poke at the saved cwnd
* as well as the cwnd.
*/
cwnd = bbr->r_ctl.rc_saved_cwnd;
cwnd_p = &bbr->r_ctl.rc_saved_cwnd;
} else {
cwnd = tp->snd_cwnd;
cwnd_p = &tp->snd_cwnd;
}
maxseg = tp->t_maxseg - bbr->rc_last_options;
/* Add the overall lr with the recovery lr */
if (bbr->r_ctl.rc_lost == 0)
lr2use = 0;
else if (bbr->r_ctl.rc_delivered == 0)
lr2use = 1000;
else {
lr2use = bbr->r_ctl.rc_lost * 1000;
lr2use /= bbr->r_ctl.rc_delivered;
}
lr2use += bbr->r_ctl.recovery_lr;
acks_inflight = (flight / (maxseg * 2));
if (bbr_red_scale) {
lr2use *= bbr_get_rtt(bbr, BBR_SRTT);
lr2use /= bbr_red_scale;
if ((bbr_red_growth_restrict) &&
((bbr_get_rtt(bbr, BBR_SRTT)/bbr_red_scale) > 1))
bbr->r_ctl.restrict_growth += acks_inflight;
}
if (lr2use) {
val = (uint64_t)cwnd * lr2use;
val /= 1000;
if (cwnd > val)
newcwnd = roundup((cwnd - val), maxseg);
else
newcwnd = maxseg;
} else {
val = (uint64_t)cwnd * (uint64_t)bbr_red_mul;
val /= (uint64_t)bbr_red_div;
newcwnd = roundup((uint32_t)val, maxseg);
}
/* with standard delayed acks how many acks can I expect? */
if (bbr_drop_limit == 0) {
/*
* Anticpate how much we will
* raise the cwnd based on the acks.
*/
if ((newcwnd + (acks_inflight * maxseg)) < get_min_cwnd(bbr)) {
/* We do enforce the min (with the acks) */
newcwnd = (get_min_cwnd(bbr) - acks_inflight);
}
} else {
/*
* A strict drop limit of N is is inplace
*/
if (newcwnd < (bbr_drop_limit * maxseg)) {
newcwnd = bbr_drop_limit * maxseg;
}
}
/* For the next N acks do we restrict the growth */
*cwnd_p = newcwnd;
if (tp->snd_cwnd > newcwnd)
tp->snd_cwnd = newcwnd;
bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div, val, 22,
(uint32_t)lr2use,
bbr_get_rtt(bbr, BBR_SRTT), __LINE__);
bbr->r_ctl.rc_red_cwnd_pe = bbr->r_ctl.rc_pkt_epoch;
}
done:
bbr->r_ctl.recovery_lr = 0;
if (flight <= tp->snd_cwnd) {
bbr->r_wanted_output = 1;
}
tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
}
static void
bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts)
{
bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
/* Limit the drop in b/w to 1/2 our current filter. */
if (bbr->r_ctl.red_bw > bbr->r_ctl.rc_bbr_cur_del_rate)
bbr->r_ctl.red_bw = bbr->r_ctl.rc_bbr_cur_del_rate;
if (bbr->r_ctl.red_bw < (get_filter_value(&bbr->r_ctl.rc_delrate) / 2))
bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate) / 2;
tcp_bbr_tso_size_check(bbr, cts);
}
static void
bbr_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type, struct bbr_sendmap *rsm)
{
struct tcp_bbr *bbr;
INP_WLOCK_ASSERT(tp->t_inpcb);
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
switch (type) {
case CC_NDUPACK:
if (!IN_RECOVERY(tp->t_flags)) {
tp->snd_recover = tp->snd_max;
/* Start a new epoch */
bbr_set_pktepoch(bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
if (bbr->rc_lt_is_sampling || bbr->rc_lt_use_bw) {
/*
* Move forward the lt epoch
* so it won't count the truncated
* epoch.
*/
bbr->r_ctl.rc_lt_epoch++;
}
if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
/*
* Just like the policer detection code
* if we are in startup we must push
* forward the last startup epoch
* to hide the truncated PE.
*/
bbr->r_ctl.rc_bbr_last_startup_epoch++;
}
bbr->r_ctl.rc_cwnd_on_ent = tp->snd_cwnd;
ENTER_RECOVERY(tp->t_flags);
bbr->rc_tlp_rtx_out = 0;
bbr->r_ctl.recovery_lr = bbr->r_ctl.rc_pkt_epoch_loss_rate;
tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
if (bbr->rc_inp->inp_in_hpts &&
((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) == 0)) {
/*
* When we enter recovery, we need to restart
* any timers. This may mean we gain an agg
* early, which will be made up for at the last
* rxt out.
*/
bbr->rc_timer_first = 1;
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
}
/*
* Calculate a new cwnd based on to the current
* delivery rate with no gain. We get the bdp
* without gaining it up like we normally would and
* we use the last cur_del_rate.
*/
if ((bbr->rc_use_google == 0) &&
(bbr->r_ctl.bbr_rttprobe_gain_val ||
(bbr->rc_bbr_state != BBR_STATE_PROBE_RTT))) {
tp->snd_cwnd = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
(tp->t_maxseg - bbr->rc_last_options);
if (tp->snd_cwnd < get_min_cwnd(bbr)) {
/* We always gate to min cwnd */
tp->snd_cwnd = get_min_cwnd(bbr);
}
bbr_log_type_cwndupd(bbr, 0, 0, 0, 14, 0, 0, __LINE__);
}
bbr_log_type_enter_rec(bbr, rsm->r_start);
}
break;
case CC_RTO_ERR:
TCPSTAT_INC(tcps_sndrexmitbad);
/* RTO was unnecessary, so reset everything. */
bbr_reset_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime);
if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
tp->snd_cwnd = tp->snd_cwnd_prev;
tp->snd_ssthresh = tp->snd_ssthresh_prev;
tp->snd_recover = tp->snd_recover_prev;
tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
bbr_log_type_cwndupd(bbr, 0, 0, 0, 13, 0, 0, __LINE__);
}
tp->t_badrxtwin = 0;
break;
}
}
/*
* 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.
* - The data being acked is less than a full segment (a stretch ack
* of more than a segment we should ack.
* - nsegs is 1 (if its more than that we received more than 1 ack).
*/
#define DELAY_ACK(tp, bbr, nsegs) \
(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
((bbr->bbr_segs_rcvd + nsegs) < tp->t_delayed_ack) && \
(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
/*
* Return the lowest RSM in the map of
* packets still in flight that is not acked.
* This should normally find on the first one
* since we remove packets from the send
* map after they are marked ACKED.
*/
static struct bbr_sendmap *
bbr_find_lowest_rsm(struct tcp_bbr *bbr)
{
struct bbr_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, &bbr->r_ctl.rc_tmap, r_tnext) {
if (rsm->r_flags & BBR_ACKED) {
continue;
}
goto finish;
}
finish:
return (rsm);
}
static struct bbr_sendmap *
bbr_find_high_nonack(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
{
struct bbr_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).
*/
prsm = rsm;
TAILQ_FOREACH_REVERSE_FROM(prsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
if (prsm->r_flags & (BBR_ACKED | BBR_HAS_FIN)) {
continue;
}
return (prsm);
}
return (NULL);
}
/*
* Returns to the caller the number of microseconds that
* the packet can be outstanding before we think we
* should have had an ack returned.
*/
static uint32_t
bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm)
{
/*
* 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.
*/
int32_t lro;
uint32_t thresh, t_rxtcur;
if (srtt == 0)
srtt = 1;
if (bbr->r_ctl.rc_reorder_ts) {
if (bbr->r_ctl.rc_reorder_fade) {
if (SEQ_GEQ(cts, bbr->r_ctl.rc_reorder_ts)) {
lro = cts - bbr->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 > bbr->r_ctl.rc_reorder_fade) {
/* Turn off reordering seen too */
bbr->r_ctl.rc_reorder_ts = 0;
lro = 0;
}
} else {
/* Reodering does not fade */
lro = 1;
}
} else {
lro = 0;
}
thresh = srtt + bbr->r_ctl.rc_pkt_delay;
if (lro) {
/* It must be set, if not you get 1/4 rtt */
if (bbr->r_ctl.rc_reorder_shift)
thresh += (srtt >> bbr->r_ctl.rc_reorder_shift);
else
thresh += (srtt >> 2);
} else {
thresh += 1000;
}
/* We don't let the rack timeout be above a RTO */
if ((bbr->rc_tp)->t_srtt == 0)
t_rxtcur = BBR_INITIAL_RTO;
else
t_rxtcur = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
if (thresh > t_rxtcur) {
thresh = t_rxtcur;
}
/* And we don't want it above the RTO max either */
if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
}
bbr_log_thresh_choice(bbr, cts, thresh, lro, srtt, rsm, BBR_TO_FRM_RACK);
return (thresh);
}
/*
* Return to the caller the amount of time in mico-seconds
* that should be used for the TLP timer from the last
* send time of this packet.
*/
static uint32_t
bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
struct bbr_sendmap *rsm, uint32_t srtt,
uint32_t cts)
{
uint32_t thresh, len, maxseg, t_rxtcur;
struct bbr_sendmap *prsm;
if (srtt == 0)
srtt = 1;
if (bbr->rc_tlp_threshold)
thresh = srtt + (srtt / bbr->rc_tlp_threshold);
else
thresh = (srtt * 2);
maxseg = tp->t_maxseg - bbr->rc_last_options;
/* Get the previous sent packet, if any */
len = rsm->r_end - rsm->r_start;
/* 2.1 behavior */
prsm = TAILQ_PREV(rsm, bbr_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;
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;
alt_thresh = srtt + (srtt / 2) + bbr_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
/* Not above the current RTO */
if (tp->t_srtt == 0)
t_rxtcur = BBR_INITIAL_RTO;
else
t_rxtcur = TICKS_2_USEC(tp->t_rxtcur);
bbr_log_thresh_choice(bbr, cts, thresh, t_rxtcur, srtt, rsm, BBR_TO_FRM_TLP);
/* Not above an RTO */
if (thresh > t_rxtcur) {
thresh = t_rxtcur;
}
/* Not above a RTO max */
if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
}
/* And now apply the user TLP min */
if (thresh < bbr_tlp_min) {
thresh = bbr_tlp_min;
}
return (thresh);
}
/*
* Return one of three RTTs to use (in microseconds).
*/
static __inline uint32_t
bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type)
{
uint32_t f_rtt;
uint32_t srtt;
f_rtt = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
if (get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) {
/* We have no rtt at all */
if (bbr->rc_tp->t_srtt == 0)
f_rtt = BBR_INITIAL_RTO;
else
f_rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
/*
* Since we don't know how good the rtt is apply a
* delayed-ack min
*/
if (f_rtt < bbr_delayed_ack_time) {
f_rtt = bbr_delayed_ack_time;
}
}
/* Take the filter version or last measured pkt-rtt */
if (rtt_type == BBR_RTT_PROP) {
srtt = f_rtt;
} else if (rtt_type == BBR_RTT_PKTRTT) {
if (bbr->r_ctl.rc_pkt_epoch_rtt) {
srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
} else {
/* No pkt rtt yet */
srtt = f_rtt;
}
} else if (rtt_type == BBR_RTT_RACK) {
srtt = bbr->r_ctl.rc_last_rtt;
/* We need to add in any internal delay for our timer */
if (bbr->rc_ack_was_delayed)
srtt += bbr->r_ctl.rc_ack_hdwr_delay;
} else if (rtt_type == BBR_SRTT) {
srtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
} else {
/* TSNH */
srtt = f_rtt;
#ifdef BBR_INVARIANTS
panic("Unknown rtt request type %d", rtt_type);
#endif
}
return (srtt);
}
static int
bbr_is_lost(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t cts)
{
uint32_t thresh;
thresh = bbr_calc_thresh_rack(bbr, bbr_get_rtt(bbr, BBR_RTT_RACK),
cts, rsm);
if ((cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) >= thresh) {
/* It is lost (past time) */
return (1);
}
return (0);
}
/*
* Return a sendmap if we need to retransmit something.
*/
static struct bbr_sendmap *
bbr_check_recovery_mode(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
/*
* 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 bbr_sendmap *rsm;
int32_t idx;
if (TAILQ_EMPTY(&bbr->r_ctl.rc_map)) {
/* Nothing outstanding that we know of */
return (NULL);
}
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if (rsm == NULL) {
/* Nothing in the transmit map */
return (NULL);
}
if (tp->t_flags & TF_SENTFIN) {
/* Fin restricted, don't find anything once a fin is sent */
return (NULL);
}
if (rsm->r_flags & BBR_ACKED) {
/*
* Ok the first one is acked (this really should not happen
* since we remove the from the tmap once they are acked)
*/
rsm = bbr_find_lowest_rsm(bbr);
if (rsm == NULL)
return (NULL);
}
idx = rsm->r_rtr_cnt - 1;
if (SEQ_LEQ(cts, rsm->r_tim_lastsent[idx])) {
/* Send timestamp is the same or less? can't be ready */
return (NULL);
}
/* Get our RTT time */
if (bbr_is_lost(bbr, rsm, cts) &&
((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
(rsm->r_flags & BBR_SACK_PASSED))) {
if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
rsm->r_flags |= BBR_MARKED_LOST;
bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
}
bbr_cong_signal(tp, NULL, CC_NDUPACK, rsm);
#ifdef BBR_INVARIANTS
if ((rsm->r_end - rsm->r_start) == 0)
panic("tp:%p bbr:%p rsm:%p length is 0?", tp, bbr, rsm);
#endif
return (rsm);
}
return (NULL);
}
/*
* RACK Timer, here we simply do logging and house keeping.
* the normal bbr_output_wtime() function will call the
* appropriate thing to check if we need to do a RACK retransmit.
* We return 1, saying don't proceed with bbr_output_wtime only
* when all timers have been stopped (destroyed PCB?).
*/
static int
bbr_timeout_rack(struct tcpcb *tp, struct tcp_bbr *bbr, 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.
*/
uint32_t lost;
if (bbr->rc_all_timers_stopped) {
return (1);
}
if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
/* Its not time yet */
return (0);
}
BBR_STAT_INC(bbr_to_tot);
lost = bbr->r_ctl.rc_lost;
if (bbr->r_state && (bbr->r_state != tp->t_state))
bbr_set_state(tp, bbr, 0);
bbr_log_to_event(bbr, cts, BBR_TO_FRM_RACK);
if (bbr->r_ctl.rc_resend == NULL) {
/* Lets do the check here */
bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
}
if (bbr_policer_call_from_rack_to)
bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
return (0);
}
static __inline void
bbr_clone_rsm(struct tcp_bbr *bbr, struct bbr_sendmap *nrsm, struct bbr_sendmap *rsm, uint32_t start)
{
int idx;
nrsm->r_start = start;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
/* We don't transfer forward the SYN flag */
nrsm->r_flags &= ~BBR_HAS_SYN;
/* We move forward the FIN flag, not that this should happen */
rsm->r_flags &= ~BBR_HAS_FIN;
nrsm->r_dupack = rsm->r_dupack;
nrsm->r_rtr_bytes = 0;
nrsm->r_is_gain = rsm->r_is_gain;
nrsm->r_is_drain = rsm->r_is_drain;
nrsm->r_delivered = rsm->r_delivered;
nrsm->r_ts_valid = rsm->r_ts_valid;
nrsm->r_del_ack_ts = rsm->r_del_ack_ts;
nrsm->r_del_time = rsm->r_del_time;
nrsm->r_app_limited = rsm->r_app_limited;
nrsm->r_first_sent_time = rsm->r_first_sent_time;
nrsm->r_flight_at_send = rsm->r_flight_at_send;
/* We split a piece the lower section looses any just_ret flag. */
nrsm->r_bbr_state = rsm->r_bbr_state;
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;
idx = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
idx /= 8;
/* Check if we got too small */
if ((rsm->r_is_smallmap == 0) &&
((rsm->r_end - rsm->r_start) <= idx)) {
bbr->r_ctl.rc_num_small_maps_alloced++;
rsm->r_is_smallmap = 1;
}
/* Check the new one as well */
if ((nrsm->r_end - nrsm->r_start) <= idx) {
bbr->r_ctl.rc_num_small_maps_alloced++;
nrsm->r_is_smallmap = 1;
}
}
static int
bbr_sack_mergable(struct bbr_sendmap *at,
uint32_t start, uint32_t end)
{
/*
* Given a sack block defined by
* start and end, and a current postion
* at. Return 1 if either side of at
* would show that the block is mergable
* to that side. A block to be mergable
* must have overlap with the start/end
* and be in the SACK'd state.
*/
struct bbr_sendmap *l_rsm;
struct bbr_sendmap *r_rsm;
/* first get the either side blocks */
l_rsm = TAILQ_PREV(at, bbr_head, r_next);
r_rsm = TAILQ_NEXT(at, r_next);
if (l_rsm && (l_rsm->r_flags & BBR_ACKED)) {
/* Potentially mergeable */
if ((l_rsm->r_end == start) ||
(SEQ_LT(start, l_rsm->r_end) &&
SEQ_GT(end, l_rsm->r_end))) {
/*
* map blk |------|
* sack blk |------|
* <or>
* map blk |------|
* sack blk |------|
*/
return (1);
}
}
if (r_rsm && (r_rsm->r_flags & BBR_ACKED)) {
/* Potentially mergeable */
if ((r_rsm->r_start == end) ||
(SEQ_LT(start, r_rsm->r_start) &&
SEQ_GT(end, r_rsm->r_start))) {
/*
* map blk |---------|
* sack blk |----|
* <or>
* map blk |---------|
* sack blk |-------|
*/
return (1);
}
}
return (0);
}
static struct bbr_sendmap *
bbr_merge_rsm(struct tcp_bbr *bbr,
struct bbr_sendmap *l_rsm,
struct bbr_sendmap *r_rsm)
{
/*
* We are merging two ack'd RSM's,
* the l_rsm is on the left (lower seq
* values) and the r_rsm is on the right
* (higher seq value). The simplest way
* to merge these is to move the right
* one into the left. I don't think there
* is any reason we need to try to find
* the oldest (or last oldest retransmitted).
*/
l_rsm->r_end = r_rsm->r_end;
if (l_rsm->r_dupack < r_rsm->r_dupack)
l_rsm->r_dupack = r_rsm->r_dupack;
if (r_rsm->r_rtr_bytes)
l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
if (r_rsm->r_in_tmap) {
/* This really should not happen */
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, r_rsm, r_tnext);
}
if (r_rsm->r_app_limited)
l_rsm->r_app_limited = r_rsm->r_app_limited;
/* Now the flags */
if (r_rsm->r_flags & BBR_HAS_FIN)
l_rsm->r_flags |= BBR_HAS_FIN;
if (r_rsm->r_flags & BBR_TLP)
l_rsm->r_flags |= BBR_TLP;
if (r_rsm->r_flags & BBR_RWND_COLLAPSED)
l_rsm->r_flags |= BBR_RWND_COLLAPSED;
if (r_rsm->r_flags & BBR_MARKED_LOST) {
/* This really should not happen */
bbr->r_ctl.rc_lost_bytes -= r_rsm->r_end - r_rsm->r_start;
}
TAILQ_REMOVE(&bbr->r_ctl.rc_map, r_rsm, r_next);
if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
/* Transfer the split limit to the map we free */
r_rsm->r_limit_type = l_rsm->r_limit_type;
l_rsm->r_limit_type = 0;
}
bbr_free(bbr, r_rsm);
return(l_rsm);
}
/*
* TLP Timer, here we simply setup what segment we want to
* have the TLP expire on, the normal bbr_output_wtime() will then
* send it out.
*
* We return 1, saying don't proceed with bbr_output_wtime only
* when all timers have been stopped (destroyed PCB?).
*/
static int
bbr_timeout_tlp(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
/*
* Tail Loss Probe.
*/
struct bbr_sendmap *rsm = NULL;
struct socket *so;
uint32_t amm;
uint32_t out, avail;
uint32_t maxseg;
int collapsed_win = 0;
if (bbr->rc_all_timers_stopped) {
return (1);
}
if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
/* Its not time yet */
return (0);
}
if (bbr_progress_timeout_check(bbr)) {
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
return (1);
}
/* Did we somehow get into persists? */
if (bbr->rc_in_persist) {
return (0);
}
if (bbr->r_state && (bbr->r_state != tp->t_state))
bbr_set_state(tp, bbr, 0);
BBR_STAT_INC(bbr_tlp_tot);
maxseg = tp->t_maxseg - bbr->rc_last_options;
#ifdef KERN_TLS
if (bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
/*
* For hardware TLS we do *not* want to send
* new data.
*/
goto need_retran;
}
#endif
/*
* 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.
*/
so = tp->t_inpcb->inp_socket;
avail = sbavail(&so->so_snd);
out = ctf_outstanding(tp);
if (out > tp->snd_wnd) {
/* special case, we need a retransmission */
collapsed_win = 1;
goto need_retran;
}
if (avail > out) {
/* New data is available */
amm = avail - out;
if (amm > maxseg) {
amm = maxseg;
} else if ((amm < maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
/* not enough to fill a MTU and no-delay is off */
goto need_retran;
}
/* Set the send-new override */
if ((out + amm) <= tp->snd_wnd) {
bbr->rc_tlp_new_data = 1;
} else {
goto need_retran;
}
bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
bbr->r_ctl.rc_last_tlp_seq = tp->snd_max;
bbr->r_ctl.rc_tlp_send = NULL;
/* cap any slots */
BBR_STAT_INC(bbr_tlp_newdata);
goto send;
}
need_retran:
/*
* Ok we need to arrange the last un-acked segment to be re-sent, or
* optionally the first un-acked segment.
*/
if (collapsed_win == 0) {
rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
if (rsm && (BBR_ACKED | BBR_HAS_FIN)) {
rsm = bbr_find_high_nonack(bbr, rsm);
}
if (rsm == NULL) {
goto restore;
}
} else {
/*
* We must find the last segment
* that was acceptable by the client.
*/
TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
if ((rsm->r_flags & BBR_RWND_COLLAPSED) == 0) {
/* Found one */
break;
}
}
if (rsm == NULL) {
/* None? if so send the first */
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
if (rsm == NULL)
goto restore;
}
}
if ((rsm->r_end - rsm->r_start) > maxseg) {
/*
* We need to split this the last segment in two.
*/
struct bbr_sendmap *nrsm;
nrsm = bbr_alloc_full_limit(bbr);
if (nrsm == NULL) {
/*
* We can't get memory to split, we can either just
* not split it. Or retransmit the whole piece, lets
* do the large send (BTLP :-) ).
*/
goto go_for_it;
}
bbr_clone_rsm(bbr, nrsm, rsm, (rsm->r_end - maxseg));
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~BBR_HAS_FIN);
rsm = nrsm;
}
go_for_it:
bbr->r_ctl.rc_tlp_send = rsm;
bbr->rc_tlp_rtx_out = 1;
if (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) {
bbr->r_ctl.rc_tlp_seg_send_cnt++;
tp->t_rxtshift++;
} else {
bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
bbr->r_ctl.rc_tlp_seg_send_cnt = 1;
}
send:
if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
/*
* Can't [re]/transmit a segment we have retranmitted the
* max times. We need the retransmit timer to take over.
*/
restore:
bbr->rc_tlp_new_data = 0;
bbr->r_ctl.rc_tlp_send = NULL;
if (rsm)
rsm->r_flags &= ~BBR_TLP;
BBR_STAT_INC(bbr_tlp_retran_fail);
return (0);
} else if (rsm) {
rsm->r_flags |= BBR_TLP;
}
if (rsm && (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) &&
(bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend)) {
/*
* We have retransmitted to many times for TLP. Switch to
* the regular RTO timer
*/
goto restore;
}
bbr_log_to_event(bbr, cts, BBR_TO_FRM_TLP);
bbr->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
bbr_timeout_delack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
if (bbr->rc_all_timers_stopped) {
return (1);
}
bbr_log_to_event(bbr, cts, BBR_TO_FRM_DELACK);
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
TCPSTAT_INC(tcps_delack);
bbr->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
bbr_timeout_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
struct tcptemp *t_template;
int32_t retval = 1;
if (bbr->rc_all_timers_stopped) {
return (1);
}
if (bbr->rc_in_persist == 0)
return (0);
KASSERT(tp->t_inpcb != NULL,
("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
/*
* Persistence timer into zero window. Force a byte to be output, if
* possible.
*/
bbr_log_to_event(bbr, cts, BBR_TO_FRM_PERSIST);
bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
TCPSTAT_INC(tcps_persisttimeo);
/*
* Have we exceeded the user specified progress time?
*/
if (bbr_progress_timeout_check(bbr)) {
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
goto out;
}
/*
* 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);
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
goto out;
}
if ((sbavail(&bbr->rc_inp->inp_socket->so_snd) == 0) &&
tp->snd_una == tp->snd_max) {
bbr_exit_persist(tp, bbr, cts, __LINE__);
retval = 0;
goto out;
}
/*
* 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) {
TCPSTAT_INC(tcps_persistdrop);
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
goto out;
}
t_template = tcpip_maketemplate(bbr->rc_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);
/* This sends an ack */
if (tp->t_flags & TF_DELACK)
tp->t_flags &= ~TF_DELACK;
free(t_template, M_TEMP);
}
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
bbr_start_hpts_timer(bbr, tp, cts, 3, 0, 0);
out:
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
bbr_timeout_keepalive(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
struct tcptemp *t_template;
struct inpcb *inp;
if (bbr->rc_all_timers_stopped) {
return (1);
}
bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
inp = tp->t_inpcb;
bbr_log_to_event(bbr, cts, BBR_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);
}
}
bbr_start_hpts_timer(bbr, tp, cts, 4, 0, 0);
return (1);
dropit:
TCPSTAT_INC(tcps_keepdrops);
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
return (1);
}
/*
* Retransmit helper function, clear up all the ack
* flags and take care of important book keeping.
*/
static void
bbr_remxt_tmr(struct tcpcb *tp)
{
/*
* The retransmit timer went off, all sack'd blocks must be
* un-acked.
*/
struct bbr_sendmap *rsm, *trsm = NULL;
struct tcp_bbr *bbr;
uint32_t cts, lost;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
cts = tcp_get_usecs(&bbr->rc_tv);
lost = bbr->r_ctl.rc_lost;
if (bbr->r_state && (bbr->r_state != tp->t_state))
bbr_set_state(tp, bbr, 0);
TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
if (rsm->r_flags & BBR_ACKED) {
uint32_t old_flags;
rsm->r_dupack = 0;
if (rsm->r_in_tmap == 0) {
/* We must re-add it back to the tlist */
if (trsm == NULL) {
TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
} else {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, trsm, rsm, r_tnext);
}
rsm->r_in_tmap = 1;
}
old_flags = rsm->r_flags;
rsm->r_flags |= BBR_RXT_CLEARED;
rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS);
bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
} else {
if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
}
if (bbr_marks_rxt_sack_passed) {
/*
* With this option, we will rack out
* in 1ms increments the rest of the packets.
*/
rsm->r_flags |= BBR_SACK_PASSED | BBR_MARKED_LOST;
rsm->r_flags &= ~BBR_WAS_SACKPASS;
} else {
/*
* With this option we only mark them lost
* and remove all sack'd markings. We will run
* another RXT or a TLP. This will cause
* us to eventually send more based on what
* ack's come in.
*/
rsm->r_flags |= BBR_MARKED_LOST;
rsm->r_flags &= ~BBR_WAS_SACKPASS;
rsm->r_flags &= ~BBR_SACK_PASSED;
}
}
trsm = rsm;
}
bbr->r_ctl.rc_resend = TAILQ_FIRST(&bbr->r_ctl.rc_map);
/* Clear the count (we just un-acked them) */
bbr_log_to_event(bbr, cts, BBR_TO_FRM_TMR);
bbr->rc_tlp_new_data = 0;
bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
/* zap the behindness on a rxt */
bbr->r_ctl.rc_hptsi_agg_delay = 0;
bbr->r_agg_early_set = 0;
bbr->r_ctl.rc_agg_early = 0;
bbr->rc_tlp_rtx_out = 0;
bbr->r_ctl.rc_sacked = 0;
bbr->r_ctl.rc_sacklast = NULL;
bbr->r_timer_override = 1;
bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
}
/*
* 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
bbr_timeout_rxt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
int32_t rexmt;
int32_t retval = 0;
bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
if (bbr->rc_all_timers_stopped) {
return (1);
}
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 (bbr_progress_timeout_check(bbr)) {
retval = 1;
tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
goto out;
}
bbr_remxt_tmr(tp);
if ((bbr->r_ctl.rc_resend == NULL) ||
((bbr->r_ctl.rc_resend->r_flags & BBR_RWND_COLLAPSED) == 0)) {
/*
* If the rwnd collapsed on
* the one we are retransmitting
* it does not count against the
* rxt count.
*/
tp->t_rxtshift++;
}
if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
TCPSTAT_INC(tcps_timeoutdrop);
retval = 1;
tcp_set_inp_to_drop(bbr->rc_inp,
(tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
goto out;
}
if (tp->t_state == TCPS_SYN_SENT) {
/*
* If the SYN was retransmitted, indicate CWND to be limited
* to 1 segment in cc_conn_init().
*/
tp->snd_cwnd = 1;
} else if (tp->t_rxtshift == 1) {
/*
* first retransmit; record ssthresh and cwnd so they can be
* recovered if this turns out to be a "bad" retransmit. A
* retransmit is considered "bad" if an ACK for this segment
* is received within RTT/2 interval; the assumption here is
* that the ACK was already in flight. See "On Estimating
* End-to-End Network Path Properties" by Allman and Paxson
* for more details.
*/
tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
if (!IN_RECOVERY(tp->t_flags)) {
tp->snd_cwnd_prev = tp->snd_cwnd;
tp->snd_ssthresh_prev = tp->snd_ssthresh;
tp->snd_recover_prev = tp->snd_recover;
tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
tp->t_flags |= TF_PREVVALID;
} else {
tp->t_flags &= ~TF_PREVVALID;
}
tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
} else {
tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
tp->t_flags &= ~TF_PREVVALID;
}
TCPSTAT_INC(tcps_rexmttimeo);
if ((tp->t_state == TCPS_SYN_SENT) ||
(tp->t_state == TCPS_SYN_RECEIVED))
rexmt = USEC_2_TICKS(BBR_INITIAL_RTO) * tcp_backoff[tp->t_rxtshift];
else
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
TCPT_RANGESET(tp->t_rxtcur, rexmt,
MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms),
MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
/*
* 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 = bbr->r_is_v6;
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 (bbr->r_is_v6)
in6_losing(tp->t_inpcb);
else
#endif
in_losing(tp->t_inpcb);
tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
tp->t_srtt = 0;
}
sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
tp->snd_recover = tp->snd_max;
tp->t_flags |= TF_ACKNOW;
tp->t_rtttime = 0;
out:
return (retval);
}
static int
bbr_process_timers(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, uint8_t hpts_calling)
{
int32_t ret = 0;
int32_t timers = (bbr->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 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
return (0);
return (1);
}
if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
uint32_t left;
if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
ret = -1;
bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
return (0);
}
if (hpts_calling == 0) {
ret = -2;
bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
return (0);
}
/*
* Ok our timer went off early and we are not paced false
* alarm, go back to sleep.
*/
left = bbr->r_ctl.rc_timer_exp - cts;
ret = -3;
bbr_log_to_processing(bbr, cts, ret, left, hpts_calling);
tcp_hpts_insert(tp->t_inpcb, HPTS_USEC_TO_SLOTS(left));
return (1);
}
bbr->rc_tmr_stopped = 0;
bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
if (timers & PACE_TMR_DELACK) {
ret = bbr_timeout_delack(tp, bbr, cts);
} else if (timers & PACE_TMR_PERSIT) {
ret = bbr_timeout_persist(tp, bbr, cts);
} else if (timers & PACE_TMR_RACK) {
bbr->r_ctl.rc_tlp_rxt_last_time = cts;
ret = bbr_timeout_rack(tp, bbr, cts);
} else if (timers & PACE_TMR_TLP) {
bbr->r_ctl.rc_tlp_rxt_last_time = cts;
ret = bbr_timeout_tlp(tp, bbr, cts);
} else if (timers & PACE_TMR_RXT) {
bbr->r_ctl.rc_tlp_rxt_last_time = cts;
ret = bbr_timeout_rxt(tp, bbr, cts);
} else if (timers & PACE_TMR_KEEP) {
ret = bbr_timeout_keepalive(tp, bbr, cts);
}
bbr_log_to_processing(bbr, cts, ret, timers, hpts_calling);
return (ret);
}
static void
bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts)
{
if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
uint8_t hpts_removed = 0;
if (bbr->rc_inp->inp_in_hpts &&
(bbr->rc_timer_first == 1)) {
/*
* If we are canceling timer's when we have the
* timer ahead of the output being paced. We also
* must remove ourselves from the hpts.
*/
hpts_removed = 1;
tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
if (bbr->r_ctl.rc_last_delay_val) {
/* Update the last hptsi delay too */
uint32_t time_since_send;
if (TSTMP_GT(cts, bbr->rc_pacer_started))
time_since_send = cts - bbr->rc_pacer_started;
else
time_since_send = 0;
if (bbr->r_ctl.rc_last_delay_val > time_since_send) {
/* Cut down our slot time */
bbr->r_ctl.rc_last_delay_val -= time_since_send;
} else {
bbr->r_ctl.rc_last_delay_val = 0;
}
bbr->rc_pacer_started = cts;
}
}
bbr->rc_timer_first = 0;
bbr_log_to_cancel(bbr, line, cts, hpts_removed);
bbr->rc_tmr_stopped = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
bbr->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
}
}
static void
bbr_timer_stop(struct tcpcb *tp, uint32_t timer_type)
{
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
bbr->rc_all_timers_stopped = 1;
return;
}
/*
* stop all timers always returning 0.
*/
static int
bbr_stopall(struct tcpcb *tp)
{
return (0);
}
static void
bbr_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
{
return;
}
/*
* return true if a bbr timer (rack or tlp) is active.
*/
static int
bbr_timer_active(struct tcpcb *tp, uint32_t timer_type)
{
return (0);
}
static uint32_t
bbr_get_earliest_send_outstanding(struct tcp_bbr *bbr, struct bbr_sendmap *u_rsm, uint32_t cts)
{
struct bbr_sendmap *rsm;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if ((rsm == NULL) || (u_rsm == rsm))
return (cts);
return(rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
}
static void
bbr_update_rsm(struct tcpcb *tp, struct tcp_bbr *bbr,
struct bbr_sendmap *rsm, uint32_t cts, uint32_t pacing_time)
{
int32_t idx;
rsm->r_rtr_cnt++;
rsm->r_dupack = 0;
if (rsm->r_rtr_cnt > BBR_NUM_OF_RETRANS) {
rsm->r_rtr_cnt = BBR_NUM_OF_RETRANS;
rsm->r_flags |= BBR_OVERMAX;
}
if (rsm->r_flags & BBR_RWND_COLLAPSED) {
/* Take off the collapsed flag at rxt */
rsm->r_flags &= ~BBR_RWND_COLLAPSED;
}
if (rsm->r_flags & BBR_MARKED_LOST) {
/* We have retransmitted, its no longer lost */
rsm->r_flags &= ~BBR_MARKED_LOST;
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
}
if (rsm->r_flags & BBR_RXT_CLEARED) {
/*
* We hit a RXT timer on it and
* we cleared the "acked" flag.
* We now have it going back into
* flight, we can remove the cleared
* flag and possibly do accounting on
* this piece.
*/
rsm->r_flags &= ~BBR_RXT_CLEARED;
}
if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & BBR_TLP) == 0)) {
bbr->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] = cts;
rsm->r_pacing_delay = pacing_time;
rsm->r_delivered = bbr->r_ctl.rc_delivered;
rsm->r_ts_valid = bbr->rc_ts_valid;
if (bbr->rc_ts_valid)
rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
if (bbr->r_ctl.r_app_limited_until)
rsm->r_app_limited = 1;
else
rsm->r_app_limited = 0;
if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
rsm->r_bbr_state = bbr_state_val(bbr);
else
rsm->r_bbr_state = 8;
if (rsm->r_flags & BBR_ACKED) {
/* Problably MTU discovery messing with us */
uint32_t old_flags;
old_flags = rsm->r_flags;
rsm->r_flags &= ~BBR_ACKED;
bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
if (bbr->r_ctl.rc_sacked == 0)
bbr->r_ctl.rc_sacklast = NULL;
}
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
}
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
if (rsm->r_flags & BBR_SACK_PASSED) {
/* We have retransmitted due to the SACK pass */
rsm->r_flags &= ~BBR_SACK_PASSED;
rsm->r_flags |= BBR_WAS_SACKPASS;
}
rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
rsm->r_is_gain = 1;
rsm->r_is_drain = 0;
} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
rsm->r_is_drain = 1;
rsm->r_is_gain = 0;
} else {
rsm->r_is_drain = 0;
rsm->r_is_gain = 0;
}
rsm->r_del_time = bbr->r_ctl.rc_del_time; /* TEMP GOOGLE CODE */
}
/*
* Returns 0, or the sequence where we stopped
* updating. We also update the lenp to be the amount
* of data left.
*/
static uint32_t
bbr_update_entry(struct tcpcb *tp, struct tcp_bbr *bbr,
struct bbr_sendmap *rsm, uint32_t cts, int32_t *lenp, uint32_t pacing_time)
{
/*
* We (re-)transmitted starting at rsm->r_start for some length
* (possibly less than r_end.
*/
struct bbr_sendmap *nrsm;
uint32_t c_end;
int32_t len;
len = *lenp;
c_end = rsm->r_start + len;
if (SEQ_GEQ(c_end, rsm->r_end)) {
/*
* We retransmitted the whole piece or more than the whole
* slopping into the next rsm.
*/
bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
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 = bbr_alloc_full_limit(bbr);
if (nrsm == NULL) {
*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.
*/
bbr_clone_rsm(bbr, nrsm, rsm, c_end);
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
nrsm->r_dupack = 0;
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~BBR_HAS_FIN);
bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
*lenp = 0;
return (0);
}
static uint64_t
bbr_get_hardware_rate(struct tcp_bbr *bbr)
{
uint64_t bw;
bw = bbr_get_bw(bbr);
bw *= (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN];
bw /= (uint64_t)BBR_UNIT;
return(bw);
}
static void
bbr_setup_less_of_rate(struct tcp_bbr *bbr, uint32_t cts,
uint64_t act_rate, uint64_t rate_wanted)
{
/*
* We could not get a full gains worth
* of rate.
*/
if (get_filter_value(&bbr->r_ctl.rc_delrate) >= act_rate) {
/* we can't even get the real rate */
uint64_t red;
bbr->skip_gain = 1;
bbr->gain_is_limited = 0;
red = get_filter_value(&bbr->r_ctl.rc_delrate) - act_rate;
if (red)
filter_reduce_by(&bbr->r_ctl.rc_delrate, red, cts);
} else {
/* We can use a lower gain */
bbr->skip_gain = 0;
bbr->gain_is_limited = 1;
}
}
static void
bbr_update_hardware_pacing_rate(struct tcp_bbr *bbr, uint32_t cts)
{
const struct tcp_hwrate_limit_table *nrte;
int error, rate = -1;
if (bbr->r_ctl.crte == NULL)
return;
if ((bbr->rc_inp->inp_route.ro_rt == NULL) ||
(bbr->rc_inp->inp_route.ro_rt->rt_ifp == NULL)) {
/* Lost our routes? */
/* Clear the way for a re-attempt */
bbr->bbr_attempt_hdwr_pace = 0;
lost_rate:
bbr->gain_is_limited = 0;
bbr->skip_gain = 0;
bbr->bbr_hdrw_pacing = 0;
counter_u64_add(bbr_flows_whdwr_pacing, -1);
counter_u64_add(bbr_flows_nohdwr_pacing, 1);
tcp_bbr_tso_size_check(bbr, cts);
return;
}
rate = bbr_get_hardware_rate(bbr);
nrte = tcp_chg_pacing_rate(bbr->r_ctl.crte,
bbr->rc_tp,
bbr->rc_inp->inp_route.ro_rt->rt_ifp,
rate,
(RS_PACING_GEQ|RS_PACING_SUB_OK),
&error);
if (nrte == NULL) {
goto lost_rate;
}
if (nrte != bbr->r_ctl.crte) {
bbr->r_ctl.crte = nrte;
if (error == 0) {
BBR_STAT_INC(bbr_hdwr_rl_mod_ok);
if (bbr->r_ctl.crte->rate < rate) {
/* We have a problem */
bbr_setup_less_of_rate(bbr, cts,
bbr->r_ctl.crte->rate, rate);
} else {
/* We are good */
bbr->gain_is_limited = 0;
bbr->skip_gain = 0;
}
} else {
/* A failure should release the tag */
BBR_STAT_INC(bbr_hdwr_rl_mod_fail);
bbr->gain_is_limited = 0;
bbr->skip_gain = 0;
bbr->bbr_hdrw_pacing = 0;
}
bbr_type_log_hdwr_pacing(bbr,
bbr->r_ctl.crte->ptbl->rs_ifp,
rate,
((bbr->r_ctl.crte == NULL) ? 0 : bbr->r_ctl.crte->rate),
__LINE__,
cts,
error);
}
}
static void
bbr_adjust_for_hw_pacing(struct tcp_bbr *bbr, uint32_t cts)
{
/*
* If we have hardware pacing support
* we need to factor that in for our
* TSO size.
*/
const struct tcp_hwrate_limit_table *rlp;
uint32_t cur_delay, seg_sz, maxseg, new_tso, delta, hdwr_delay;
if ((bbr->bbr_hdrw_pacing == 0) ||
(IN_RECOVERY(bbr->rc_tp->t_flags)) ||
(bbr->r_ctl.crte == NULL))
return;
if (bbr->hw_pacing_set == 0) {
/* Not yet by the hdwr pacing count delay */
return;
}
if (bbr_hdwr_pace_adjust == 0) {
/* No adjustment */
return;
}
rlp = bbr->r_ctl.crte;
if (bbr->rc_tp->t_maxseg > bbr->rc_last_options)
maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
else
maxseg = BBR_MIN_SEG - bbr->rc_last_options;
/*
* So lets first get the
* time we will take between
* TSO sized sends currently without
* hardware help.
*/
cur_delay = bbr_get_pacing_delay(bbr, BBR_UNIT,
bbr->r_ctl.rc_pace_max_segs, cts, 1);
hdwr_delay = bbr->r_ctl.rc_pace_max_segs / maxseg;
hdwr_delay *= rlp->time_between;
if (cur_delay > hdwr_delay)
delta = cur_delay - hdwr_delay;
else
delta = 0;
bbr_log_type_tsosize(bbr, cts, delta, cur_delay, hdwr_delay,
(bbr->r_ctl.rc_pace_max_segs / maxseg),
1);
if (delta &&
(delta < (max(rlp->time_between,
bbr->r_ctl.bbr_hptsi_segments_delay_tar)))) {
/*
* Now lets divide by the pacing
* time between each segment the
* hardware sends rounding up and
* derive a bytes from that. We multiply
* that by bbr_hdwr_pace_adjust to get
* more bang for our buck.
*
* The goal is to have the software pacer
* waiting no more than an additional
* pacing delay if we can (without the
* compensation i.e. x bbr_hdwr_pace_adjust).
*/
seg_sz = max(((cur_delay + rlp->time_between)/rlp->time_between),
(bbr->r_ctl.rc_pace_max_segs/maxseg));
seg_sz *= bbr_hdwr_pace_adjust;
if (bbr_hdwr_pace_floor &&
(seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
/* Currently hardware paces
* out rs_min_seg segments at a time.
* We need to make sure we always send at least
* a full burst of bbr_hdwr_pace_floor down.
*/
seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
}
seg_sz *= maxseg;
} else if (delta == 0) {
/*
* The highest pacing rate is
* above our b/w gained. This means
* we probably are going quite fast at
* the hardware highest rate. Lets just multiply
* the calculated TSO size by the
* multiplier factor (its probably
* 4 segments in the default config for
* mlx).
*/
seg_sz = bbr->r_ctl.rc_pace_max_segs * bbr_hdwr_pace_adjust;
if (bbr_hdwr_pace_floor &&
(seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
/* Currently hardware paces
* out rs_min_seg segments at a time.
* We need to make sure we always send at least
* a full burst of bbr_hdwr_pace_floor down.
*/
seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
}
} else {
/*
* The pacing time difference is so
* big that the hardware will
* pace out more rapidly then we
* really want and then we
* will have a long delay. Lets just keep
* the same TSO size so its as if
* we were not using hdwr pacing (we
* just gain a bit of spacing from the
* hardware if seg_sz > 1).
*/
seg_sz = bbr->r_ctl.rc_pace_max_segs;
}
if (seg_sz > bbr->r_ctl.rc_pace_max_segs)
new_tso = seg_sz;
else
new_tso = bbr->r_ctl.rc_pace_max_segs;
if (new_tso >= (PACE_MAX_IP_BYTES-maxseg))
new_tso = PACE_MAX_IP_BYTES - maxseg;
if (new_tso != bbr->r_ctl.rc_pace_max_segs) {
bbr_log_type_tsosize(bbr, cts, new_tso, 0, bbr->r_ctl.rc_pace_max_segs, maxseg, 0);
bbr->r_ctl.rc_pace_max_segs = new_tso;
}
}
static void
tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts)
{
uint64_t bw;
uint32_t old_tso = 0, new_tso;
uint32_t maxseg, bytes;
uint32_t tls_seg=0;
/*
* Google/linux uses the following algorithm to determine
* the TSO size based on the b/w of the link (from Neal Cardwell email 9/27/18):
*
* bytes = bw_in_bytes_per_second / 1000
* bytes = min(bytes, 64k)
* tso_segs = bytes / MSS
* if (bw < 1.2Mbs)
* min_tso_segs = 1
* else
* min_tso_segs = 2
* tso_segs = max(tso_segs, min_tso_segs)
*
* * Note apply a device specific limit (we apply this in the
* tcp_m_copym).
* Note that before the initial measurement is made google bursts out
* a full iwnd just like new-reno/cubic.
*
* We do not use this algorithm. Instead we
* use a two phased approach:
*
* if ( bw <= per-tcb-cross-over)
* goal_tso = calculate how much with this bw we
* can send in goal-time seconds.
* if (goal_tso > mss)
* seg = goal_tso / mss
* tso = seg * mss
* else
* tso = mss
* if (tso > per-tcb-max)
* tso = per-tcb-max
* else if ( bw > 512Mbps)
* tso = max-tso (64k/mss)
* else
* goal_tso = bw / per-tcb-divsor
* seg = (goal_tso + mss-1)/mss
* tso = seg * mss
*
* if (tso < per-tcb-floor)
* tso = per-tcb-floor
* if (tso > per-tcb-utter_max)
* tso = per-tcb-utter_max
*
* Note the default per-tcb-divisor is 1000 (same as google).
* the goal cross over is 30Mbps however. To recreate googles
* algorithm you need to set:
*
* cross-over = 23,168,000 bps
* goal-time = 18000
* per-tcb-max = 2
* per-tcb-divisor = 1000
* per-tcb-floor = 1
*
* This will get you "google bbr" behavior with respect to tso size.
*
* Note we do set anything TSO size until we are past the initial
* window. Before that we gnerally use either a single MSS
* or we use the full IW size (so we burst a IW at a time)
* Also note that Hardware-TLS is special and does alternate
* things to minimize PCI Bus Bandwidth use.
*/
if (bbr->rc_tp->t_maxseg > bbr->rc_last_options) {
maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
} else {
maxseg = BBR_MIN_SEG - bbr->rc_last_options;
}
#ifdef KERN_TLS
if (bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
tls_seg = ctf_get_opt_tls_size(bbr->rc_inp->inp_socket, bbr->rc_tp->snd_wnd);
bbr->r_ctl.rc_pace_min_segs = (tls_seg + bbr->rc_last_options);
}
#endif
old_tso = bbr->r_ctl.rc_pace_max_segs;
if (bbr->rc_past_init_win == 0) {
/*
* Not enough data has been acknowledged to make a
* judgement unless we are hardware TLS. Set up
* the inital TSO based on if we are sending a
* full IW at once or not.
*/
if (bbr->rc_use_google)
bbr->r_ctl.rc_pace_max_segs = ((bbr->rc_tp->t_maxseg - bbr->rc_last_options) * 2);
else if (bbr->bbr_init_win_cheat)
bbr->r_ctl.rc_pace_max_segs = bbr_initial_cwnd(bbr, bbr->rc_tp);
else
bbr->r_ctl.rc_pace_max_segs = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
if (bbr->r_ctl.rc_pace_min_segs != bbr->rc_tp->t_maxseg)
bbr->r_ctl.rc_pace_min_segs = bbr->rc_tp->t_maxseg;
#ifdef KERN_TLS
if ((bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) && tls_seg) {
/*
* For hardware TLS we set our min to the tls_seg size.
*/
bbr->r_ctl.rc_pace_max_segs = tls_seg;
bbr->r_ctl.rc_pace_min_segs = tls_seg + bbr->rc_last_options;
}
#endif
if (bbr->r_ctl.rc_pace_max_segs == 0) {
bbr->r_ctl.rc_pace_max_segs = maxseg;
}
bbr_log_type_tsosize(bbr, cts, bbr->r_ctl.rc_pace_max_segs, tls_seg, old_tso, maxseg, 0);
#ifdef KERN_TLS
if ((bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) == 0)
#endif
bbr_adjust_for_hw_pacing(bbr, cts);
return;
}
/**
* Now lets set the TSO goal based on our delivery rate in
* bytes per second. Note we only do this if
* we have acked at least the initial cwnd worth of data.
*/
bw = bbr_get_bw(bbr);
if (IN_RECOVERY(bbr->rc_tp->t_flags) &&
(bbr->rc_use_google == 0)) {
/* We clamp to one MSS in recovery */
new_tso = maxseg;
} else if (bbr->rc_use_google) {
int min_tso_segs;
/* Google considers the gain too */
if (bbr->r_ctl.rc_bbr_hptsi_gain != BBR_UNIT) {
bw *= bbr->r_ctl.rc_bbr_hptsi_gain;
bw /= BBR_UNIT;
}
bytes = bw / 1024;
if (bytes > (64 * 1024))
bytes = 64 * 1024;
new_tso = bytes / maxseg;
if (bw < ONE_POINT_TWO_MEG)
min_tso_segs = 1;
else
min_tso_segs = 2;
if (new_tso < min_tso_segs)
new_tso = min_tso_segs;
new_tso *= maxseg;
} else if (bbr->rc_no_pacing) {
new_tso = (PACE_MAX_IP_BYTES / maxseg) * maxseg;
} else if (bw <= bbr->r_ctl.bbr_cross_over) {
/*
* Calculate the worse case b/w TSO if we are inserting no
* more than a delay_target number of TSO's.
*/
uint32_t tso_len, min_tso;
tso_len = bbr_get_pacing_length(bbr, BBR_UNIT, bbr->r_ctl.bbr_hptsi_segments_delay_tar, bw);
if (tso_len > maxseg) {
new_tso = tso_len / maxseg;
if (new_tso > bbr->r_ctl.bbr_hptsi_segments_max)
new_tso = bbr->r_ctl.bbr_hptsi_segments_max;
new_tso *= maxseg;
} else {
/*
* less than a full sized frame yikes.. long rtt or
* low bw?
*/
min_tso = bbr_minseg(bbr);
if ((tso_len > min_tso) && (bbr_all_get_min == 0))
new_tso = rounddown(tso_len, min_tso);
else
new_tso = min_tso;
}
} else if (bw > FIVETWELVE_MBPS) {
/*
* This guy is so fast b/w wise that we can TSO as large as
* possible of segments that the NIC will allow.
*/
new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
} else {
/*
* This formula is based on attempting to send a segment or
* more every bbr_hptsi_per_second. The default is 1000
* which means you are targeting what you can send every 1ms
* based on the peers bw.
*
* If the number drops to say 500, then you are looking more
* at 2ms and you will raise how much we send in a single
* TSO thus saving CPU (less bbr_output_wtime() calls). The
* trade off of course is you will send more at once and
* thus tend to clump up the sends into larger "bursts"
* building a queue.
*/
bw /= bbr->r_ctl.bbr_hptsi_per_second;
new_tso = roundup(bw, (uint64_t)maxseg);
/*
* Gate the floor to match what our lower than 48Mbps
* algorithm does. The ceiling (bbr_hptsi_segments_max) thus
* becomes the floor for this calculation.
*/
if (new_tso < (bbr->r_ctl.bbr_hptsi_segments_max * maxseg))
new_tso = (bbr->r_ctl.bbr_hptsi_segments_max * maxseg);
}
if (bbr->r_ctl.bbr_hptsi_segments_floor && (new_tso < (maxseg * bbr->r_ctl.bbr_hptsi_segments_floor)))
new_tso = maxseg * bbr->r_ctl.bbr_hptsi_segments_floor;
if (new_tso > PACE_MAX_IP_BYTES)
new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
/* Enforce an utter maximum if we are not HW-TLS */
#ifdef KERN_TLS
if ((bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) == 0)
#endif
if (bbr->r_ctl.bbr_utter_max && (new_tso > (bbr->r_ctl.bbr_utter_max * maxseg))) {
new_tso = bbr->r_ctl.bbr_utter_max * maxseg;
}
#ifdef KERN_TLS
if (tls_seg) {
/*
* Lets move the output size
* up to 1 or more TLS record sizes.
*/
uint32_t temp;
temp = roundup(new_tso, tls_seg);
new_tso = temp;
/* Back down if needed to under a full frame */
while (new_tso > PACE_MAX_IP_BYTES)
new_tso -= tls_seg;
}
#endif
if (old_tso != new_tso) {
/* Only log changes */
bbr_log_type_tsosize(bbr, cts, new_tso, tls_seg, old_tso, maxseg, 0);
bbr->r_ctl.rc_pace_max_segs = new_tso;
}
#ifdef KERN_TLS
if ((bbr->rc_inp->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) &&
tls_seg) {
bbr->r_ctl.rc_pace_min_segs = tls_seg + bbr->rc_last_options;
} else
#endif
/* We have hardware pacing and not hardware TLS! */
bbr_adjust_for_hw_pacing(bbr, cts);
}
static void
bbr_log_output(struct tcp_bbr *bbr, struct tcpcb *tp, struct tcpopt *to, int32_t len,
uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t cts,
struct mbuf *mb, int32_t * abandon, struct bbr_sendmap *hintrsm, uint32_t delay_calc,
struct sockbuf *sb)
{
struct bbr_sendmap *rsm, *nrsm;
register uint32_t snd_max, snd_una;
uint32_t pacing_time;
/*
* 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).
*
*/
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
*/
*abandon = 1;
return;
}
snd_una = tp->snd_una;
if (th_flags & (TH_SYN | TH_FIN) && (hintrsm == NULL)) {
/*
* The call to bbr_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_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 (len == 0) {
/* We don't log zero window probes */
return;
}
pacing_time = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, len, cts, 1);
/* First question is it a retransmission? */
if (seq_out == snd_max) {
again:
rsm = bbr_alloc(bbr);
if (rsm == NULL) {
return;
}
rsm->r_flags = 0;
if (th_flags & TH_SYN)
rsm->r_flags |= BBR_HAS_SYN;
if (th_flags & TH_FIN)
rsm->r_flags |= BBR_HAS_FIN;
rsm->r_tim_lastsent[0] = cts;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->r_start = seq_out;
rsm->r_end = rsm->r_start + len;
rsm->r_dupack = 0;
rsm->r_delivered = bbr->r_ctl.rc_delivered;
rsm->r_pacing_delay = pacing_time;
rsm->r_ts_valid = bbr->rc_ts_valid;
if (bbr->rc_ts_valid)
rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
rsm->r_del_time = bbr->r_ctl.rc_del_time;
if (bbr->r_ctl.r_app_limited_until)
rsm->r_app_limited = 1;
else
rsm->r_app_limited = 0;
rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
/*
* Here we must also add in this rsm since snd_max
* is updated after we return from a new send.
*/
rsm->r_flight_at_send += len;
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
rsm->r_bbr_state = bbr_state_val(bbr);
else
rsm->r_bbr_state = 8;
if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
rsm->r_is_gain = 1;
rsm->r_is_drain = 0;
} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
rsm->r_is_drain = 1;
rsm->r_is_gain = 0;
} else {
rsm->r_is_drain = 0;
rsm->r_is_gain = 0;
}
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 (bbr->r_ctl.rc_next) {
/* We have a hint from a previous run */
rsm = bbr->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 = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
if (len == 0) {
return;
} else {
goto more;
}
}
/* Ok it was not the last pointer go through it the hard way. */
TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
if (rsm->r_start == seq_out) {
seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
bbr->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 = bbr_alloc_full_limit(bbr);
if (nrsm == NULL) {
bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
return;
}
/*
* copy rsm to nrsm and then trim the front of rsm
* to not include this part.
*/
bbr_clone_rsm(bbr, nrsm, rsm, seq_out);
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~BBR_HAS_FIN);
seq_out = bbr_update_entry(tp, bbr, nrsm, cts, &len, pacing_time);
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 BBR_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, &bbr->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",
bbr, tp);
#endif
} else {
#ifdef BBR_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
}
}
static void
bbr_collapse_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, int32_t rtt)
{
/*
* Collapse timeout back the cum-ack moved.
*/
tp->t_rxtshift = 0;
tp->t_softerror = 0;
}
static void
tcp_bbr_xmit_timer(struct tcp_bbr *bbr, uint32_t rtt_usecs, uint32_t rsm_send_time, uint32_t r_start, uint32_t tsin)
{
bbr->rtt_valid = 1;
bbr->r_ctl.cur_rtt = rtt_usecs;
bbr->r_ctl.ts_in = tsin;
if (rsm_send_time)
bbr->r_ctl.cur_rtt_send_time = rsm_send_time;
}
static void
bbr_make_timestamp_determination(struct tcp_bbr *bbr)
{
/**
* We have in our bbr control:
* 1) The timestamp we started observing cum-acks (bbr->r_ctl.bbr_ts_check_tstmp).
* 2) Our timestamp indicating when we sent that packet (bbr->r_ctl.rsm->bbr_ts_check_our_cts).
* 3) The current timestamp that just came in (bbr->r_ctl.last_inbound_ts)
* 4) The time that the packet that generated that ack was sent (bbr->r_ctl.cur_rtt_send_time)
*
* Now we can calculate the time between the sends by doing:
*
* delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts
*
* And the peer's time between receiving them by doing:
*
* peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp
*
* We want to figure out if the timestamp values are in msec, 10msec or usec.
* We also may find that we can't use the timestamps if say we see
* that the peer_delta indicates that though we may have taken 10ms to
* pace out the data, it only saw 1ms between the two packets. This would
* indicate that somewhere on the path is a batching entity that is giving
* out time-slices of the actual b/w. This would mean we could not use
* reliably the peers timestamps.
*
* We expect delta > peer_delta initially. Until we figure out the
* timestamp difference which we will store in bbr->r_ctl.bbr_peer_tsratio.
* If we place 1000 there then its a ms vs our usec. If we place 10000 there
* then its 10ms vs our usec. If the peer is running a usec clock we would
* put a 1 there. If the value is faster then ours, we will disable the
* use of timestamps (though we could revist this later if we find it to be not
* just an isolated one or two flows)).
*
* To detect the batching middle boxes we will come up with our compensation and
* if with it in place, we find the peer is drastically off (by some margin) in
* the smaller direction, then we will assume the worst case and disable use of timestamps.
*
*/
uint64_t delta, peer_delta, delta_up;
delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts;
if (delta < bbr_min_usec_delta) {
/*
* Have not seen a min amount of time
* between our send times so we can
* make a determination of the timestamp
* yet.
*/
return;
}
peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp;
if (peer_delta < bbr_min_peer_delta) {
/*
* We may have enough in the form of
* our delta but the peers number
* has not changed that much. It could
* be its clock ratio is such that
* we need more data (10ms tick) or
* there may be other compression scenarios
* going on. In any event we need the
* spread to be larger.
*/
return;
}
/* Ok lets first see which way our delta is going */
if (peer_delta > delta) {
/* Very unlikely, the peer without
* compensation shows that it saw
* the two sends arrive further apart
* then we saw then in micro-seconds.
*/
if (peer_delta < (delta + ((delta * (uint64_t)1000)/ (uint64_t)bbr_delta_percent))) {
/* well it looks like the peer is a micro-second clock. */
bbr->rc_ts_clock_set = 1;
bbr->r_ctl.bbr_peer_tsratio = 1;
} else {
bbr->rc_ts_cant_be_used = 1;
bbr->rc_ts_clock_set = 1;
}
return;
}
/* Ok we know that the peer_delta is smaller than our send distance */
bbr->rc_ts_clock_set = 1;
/* First question is it within the percentage that they are using usec time? */
delta_up = (peer_delta * 1000) / (uint64_t)bbr_delta_percent;
if ((peer_delta + delta_up) >= delta) {
/* Its a usec clock */
bbr->r_ctl.bbr_peer_tsratio = 1;
bbr_log_tstmp_validation(bbr, peer_delta, delta);
return;
}
/* Ok if not usec, what about 10usec (though unlikely)? */
delta_up = (peer_delta * 1000 * 10) / (uint64_t)bbr_delta_percent;
if (((peer_delta * 10) + delta_up) >= delta) {
bbr->r_ctl.bbr_peer_tsratio = 10;
bbr_log_tstmp_validation(bbr, peer_delta, delta);
return;
}
/* And what about 100usec (though again unlikely)? */
delta_up = (peer_delta * 1000 * 100) / (uint64_t)bbr_delta_percent;
if (((peer_delta * 100) + delta_up) >= delta) {
bbr->r_ctl.bbr_peer_tsratio = 100;
bbr_log_tstmp_validation(bbr, peer_delta, delta);
return;
}
/* And how about 1 msec (the most likely one)? */
delta_up = (peer_delta * 1000 * 1000) / (uint64_t)bbr_delta_percent;
if (((peer_delta * 1000) + delta_up) >= delta) {
bbr->r_ctl.bbr_peer_tsratio = 1000;
bbr_log_tstmp_validation(bbr, peer_delta, delta);
return;
}
/* Ok if not msec could it be 10 msec? */
delta_up = (peer_delta * 1000 * 10000) / (uint64_t)bbr_delta_percent;
if (((peer_delta * 10000) + delta_up) >= delta) {
bbr->r_ctl.bbr_peer_tsratio = 10000;
return;
}
/* If we fall down here the clock tick so slowly we can't use it */
bbr->rc_ts_cant_be_used = 1;
bbr->r_ctl.bbr_peer_tsratio = 0;
bbr_log_tstmp_validation(bbr, peer_delta, delta);
}
/*
* Collect new round-trip time estimate
* and update averages and current timeout.
*/
static void
tcp_bbr_xmit_timer_commit(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts)
{
int32_t delta;
uint32_t rtt, tsin;
int32_t rtt_ticks;
if (bbr->rtt_valid == 0)
/* No valid sample */
return;
rtt = bbr->r_ctl.cur_rtt;
tsin = bbr->r_ctl.ts_in;
if (bbr->rc_prtt_set_ts) {
/*
* We are to force feed the rttProp filter due
* to an entry into PROBE_RTT. This assures
* that the times are sync'd between when we
* go into PROBE_RTT and the filter expiration.
*
* Google does not use a true filter, so they do
* this implicitly since they only keep one value
* and when they enter probe-rtt they update the
* value to the newest rtt.
*/
uint32_t rtt_prop;
bbr->rc_prtt_set_ts = 0;
rtt_prop = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
if (rtt > rtt_prop)
filter_increase_by_small(&bbr->r_ctl.rc_rttprop, (rtt - rtt_prop), cts);
else
apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
}
if (bbr->rc_ack_was_delayed)
rtt += bbr->r_ctl.rc_ack_hdwr_delay;
if (rtt < bbr->r_ctl.rc_lowest_rtt)
bbr->r_ctl.rc_lowest_rtt = rtt;
bbr_log_rtt_sample(bbr, rtt, tsin);
if (bbr->r_init_rtt) {
/*
* The initial rtt is not-trusted, nuke it and lets get
* our first valid measurement in.
*/
bbr->r_init_rtt = 0;
tp->t_srtt = 0;
}
if ((bbr->rc_ts_clock_set == 0) && bbr->rc_ts_valid) {
/*
* So we have not yet figured out
* what the peers TSTMP value is
* in (most likely ms). We need a
* series of cum-ack's to determine
* this reliably.
*/
if (bbr->rc_ack_is_cumack) {
if (bbr->rc_ts_data_set) {
/* Lets attempt to determine the timestamp granularity. */
bbr_make_timestamp_determination(bbr);
} else {
bbr->rc_ts_data_set = 1;
bbr->r_ctl.bbr_ts_check_tstmp = bbr->r_ctl.last_inbound_ts;
bbr->r_ctl.bbr_ts_check_our_cts = bbr->r_ctl.cur_rtt_send_time;
}
} else {
/*
* We have to have consecutive acks
* reset any "filled" state to none.
*/
bbr->rc_ts_data_set = 0;
}
}
/* Round it up */
rtt_ticks = USEC_2_TICKS((rtt + (USECS_IN_MSEC - 1)));
if (rtt_ticks == 0)
rtt_ticks = 1;
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_ticks - 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_ticks << TCP_RTT_SHIFT;
tp->t_rttvar = rtt_ticks << (TCP_RTTVAR_SHIFT - 1);
tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
}
TCPSTAT_INC(tcps_rttupdated);
tp->t_rttupdated++;
#ifdef NETFLIX_STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt_ticks));
#endif
/*
* 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(bbr->r_ctl.rc_min_rto_ms), rtt_ticks + 2),
MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
/*
* We received an ack for a packet that wasn't retransmitted; it is
* probably safe to discard any error indications we've received
* recently. This isn't quite right, but close enough for now (a
* route might have failed after we sent a segment, and the return
* path might not be symmetrical).
*/
tp->t_softerror = 0;
rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
if (bbr->r_ctl.bbr_smallest_srtt_this_state > rtt)
bbr->r_ctl.bbr_smallest_srtt_this_state = rtt;
}
static void
bbr_earlier_retran(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm,
uint32_t t, uint32_t cts, int ack_type)
{
/*
* For this RSM, we acknowledged the data from a previous
* transmission, not the last one we made. This means we did a false
* retransmit.
*/
if (rsm->r_flags & BBR_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 & BBR_TLP) {
/*
* We expect TLP's to have this occur often
*/
bbr->rc_tlp_rtx_out = 0;
return;
}
if (ack_type != BBR_CUM_ACKED) {
/*
* If it was not a cum-ack we
* don't really know for sure since
* the timestamp could be from some
* other transmission.
*/
return;
}
if (rsm->r_flags & BBR_WAS_SACKPASS) {
/*
* We retransmitted based on a sack and the earlier
* retransmission ack'd it - re-ordering is occuring.
*/
BBR_STAT_INC(bbr_reorder_seen);
bbr->r_ctl.rc_reorder_ts = cts;
}
/* Back down the loss count */
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
rsm->r_flags &= ~BBR_MARKED_LOST;
if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
/* LT sampling also needs adjustment */
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
/***** RRS HERE ************************/
/* Do we need to do this??? */
/* bbr_reset_lt_bw_sampling(bbr, cts); */
/***** RRS HERE ************************/
BBR_STAT_INC(bbr_badfr);
BBR_STAT_ADD(bbr_badfr_bytes, (rsm->r_end - rsm->r_start));
}
static void
bbr_set_reduced_rtt(struct tcp_bbr *bbr, uint32_t cts, uint32_t line)
{
bbr->r_ctl.rc_rtt_shrinks = cts;
if (bbr_can_force_probertt &&
(TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
/*
* We should enter probe-rtt its been too long
* since we have been there.
*/
bbr_enter_probe_rtt(bbr, cts, __LINE__);
} else
bbr_check_probe_rtt_limits(bbr, cts);
}
static void
tcp_bbr_commit_bw(struct tcp_bbr *bbr, uint32_t cts)
{
uint64_t orig_bw;
if (bbr->r_ctl.rc_bbr_cur_del_rate == 0) {
/* We never apply a zero measurment */
bbr_log_type_bbrupd(bbr, 20, cts, 0, 0,
0, 0, 0, 0, 0, 0);
return;
}
if (bbr->r_ctl.r_measurement_count < 0xffffffff)
bbr->r_ctl.r_measurement_count++;
orig_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
apply_filter_max(&bbr->r_ctl.rc_delrate, bbr->r_ctl.rc_bbr_cur_del_rate, bbr->r_ctl.rc_pkt_epoch);
bbr_log_type_bbrupd(bbr, 21, cts, (uint32_t)orig_bw,
(uint32_t)get_filter_value(&bbr->r_ctl.rc_delrate),
0, 0, 0, 0, 0, 0);
if (orig_bw &&
(orig_bw != get_filter_value(&bbr->r_ctl.rc_delrate))) {
if (bbr->bbr_hdrw_pacing) {
/*
* Apply a new rate to the hardware
* possibly.
*/
bbr_update_hardware_pacing_rate(bbr, cts);
}
bbr_set_state_target(bbr, __LINE__);
tcp_bbr_tso_size_check(bbr, cts);
if (bbr->r_recovery_bw) {
bbr_setup_red_bw(bbr, cts);
bbr_log_type_bw_reduce(bbr, BBR_RED_BW_USELRBW);
}
} else if ((orig_bw == 0) && get_filter_value(&bbr->r_ctl.rc_delrate))
tcp_bbr_tso_size_check(bbr, cts);
}
static void
bbr_nf_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
{
if (bbr->rc_in_persist == 0) {
/* We log only when not in persist */
/* Translate to a Bytes Per Second */
uint64_t tim, bw, ts_diff, ts_bw;
uint32_t upper, lower, delivered;
if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
else
tim = 1;
/*
* Now that we have processed the tim (skipping the sample
* or possibly updating the time, go ahead and
* calculate the cdr.
*/
delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
bw = (uint64_t)delivered;
bw *= (uint64_t)USECS_IN_SECOND;
bw /= tim;
if (bw == 0) {
/* We must have a calculatable amount */
return;
}
upper = (bw >> 32) & 0x00000000ffffffff;
lower = bw & 0x00000000ffffffff;
/*
* If we are using this b/w shove it in now so we
* can see in the trace viewer if it gets over-ridden.
*/
if (rsm->r_ts_valid &&
bbr->rc_ts_valid &&
bbr->rc_ts_clock_set &&
(bbr->rc_ts_cant_be_used == 0) &&
bbr->rc_use_ts_limit) {
ts_diff = max((bbr->r_ctl.last_inbound_ts - rsm->r_del_ack_ts), 1);
ts_diff *= bbr->r_ctl.bbr_peer_tsratio;
if ((delivered == 0) ||
(rtt < 1000)) {
/* Can't use the ts */
bbr_log_type_bbrupd(bbr, 61, cts,
ts_diff,
bbr->r_ctl.last_inbound_ts,
rsm->r_del_ack_ts, 0,
0, 0, 0, delivered);
} else {
ts_bw = (uint64_t)delivered;
ts_bw *= (uint64_t)USECS_IN_SECOND;
ts_bw /= ts_diff;
bbr_log_type_bbrupd(bbr, 62, cts,
(ts_bw >> 32),
(ts_bw & 0xffffffff), 0, 0,
0, 0, ts_diff, delivered);
if ((bbr->ts_can_raise) &&
(ts_bw > bw)) {
bbr_log_type_bbrupd(bbr, 8, cts,
delivered,
ts_diff,
(bw >> 32),
(bw & 0x00000000ffffffff),
0, 0, 0, 0);
bw = ts_bw;
} else if (ts_bw && (ts_bw < bw)) {
bbr_log_type_bbrupd(bbr, 7, cts,
delivered,
ts_diff,
(bw >> 32),
(bw & 0x00000000ffffffff),
0, 0, 0, 0);
bw = ts_bw;
}
}
}
if (rsm->r_first_sent_time &&
TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
uint64_t sbw, sti;
/*
* We use what was in flight at the time of our
* send and the size of this send to figure
* out what we have been sending at (amount).
* For the time we take from the time of
* the send of the first send outstanding
* until this send plus this sends pacing
* time. This gives us a good calculation
* as to the rate we have been sending at.
*/
sbw = (uint64_t)(rsm->r_flight_at_send);
sbw *= (uint64_t)USECS_IN_SECOND;
sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
sti += rsm->r_pacing_delay;
sbw /= sti;
if (sbw < bw) {
bbr_log_type_bbrupd(bbr, 6, cts,
delivered,
(uint32_t)sti,
(bw >> 32),
(uint32_t)bw,
rsm->r_first_sent_time, 0, (sbw >> 32),
(uint32_t)sbw);
bw = sbw;
}
}
/* Use the google algorithm for b/w measurements */
bbr->r_ctl.rc_bbr_cur_del_rate = bw;
if ((rsm->r_app_limited == 0) ||
(bw > get_filter_value(&bbr->r_ctl.rc_delrate))) {
tcp_bbr_commit_bw(bbr, cts);
bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
}
}
}
static void
bbr_google_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
{
if (bbr->rc_in_persist == 0) {
/* We log only when not in persist */
/* Translate to a Bytes Per Second */
uint64_t tim, bw;
uint32_t upper, lower, delivered;
int no_apply = 0;
if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
else
tim = 1;
/*
* Now that we have processed the tim (skipping the sample
* or possibly updating the time, go ahead and
* calculate the cdr.
*/
delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
bw = (uint64_t)delivered;
bw *= (uint64_t)USECS_IN_SECOND;
bw /= tim;
if (tim < bbr->r_ctl.rc_lowest_rtt) {
bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
tim, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
no_apply = 1;
}
upper = (bw >> 32) & 0x00000000ffffffff;
lower = bw & 0x00000000ffffffff;
/*
* If we are using this b/w shove it in now so we
* can see in the trace viewer if it gets over-ridden.
*/
bbr->r_ctl.rc_bbr_cur_del_rate = bw;
/* Gate by the sending rate */
if (rsm->r_first_sent_time &&
TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
uint64_t sbw, sti;
/*
* We use what was in flight at the time of our
* send and the size of this send to figure
* out what we have been sending at (amount).
* For the time we take from the time of
* the send of the first send outstanding
* until this send plus this sends pacing
* time. This gives us a good calculation
* as to the rate we have been sending at.
*/
sbw = (uint64_t)(rsm->r_flight_at_send);
sbw *= (uint64_t)USECS_IN_SECOND;
sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
sti += rsm->r_pacing_delay;
sbw /= sti;
if (sbw < bw) {
bbr_log_type_bbrupd(bbr, 6, cts,
delivered,
(uint32_t)sti,
(bw >> 32),
(uint32_t)bw,
rsm->r_first_sent_time, 0, (sbw >> 32),
(uint32_t)sbw);
bw = sbw;
}
if ((sti > tim) &&
(sti < bbr->r_ctl.rc_lowest_rtt)) {
bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
(uint32_t)sti, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
no_apply = 1;
} else
no_apply = 0;
}
bbr->r_ctl.rc_bbr_cur_del_rate = bw;
if ((no_apply == 0) &&
((rsm->r_app_limited == 0) ||
(bw > get_filter_value(&bbr->r_ctl.rc_delrate)))) {
tcp_bbr_commit_bw(bbr, cts);
bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
}
}
}
static void
bbr_update_bbr_info(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts, uint32_t tsin,
uint32_t uts, int32_t match, uint32_t rsm_send_time, int32_t ack_type, struct tcpopt *to)
{
uint64_t old_rttprop;
/* Update our delivery time and amount */
bbr->r_ctl.rc_delivered += (rsm->r_end - rsm->r_start);
bbr->r_ctl.rc_del_time = cts;
if (rtt == 0) {
/*
* 0 means its a retransmit, for now we don't use these for
* the rest of BBR.
*/
return;
}
if ((bbr->rc_use_google == 0) &&
(match != BBR_RTT_BY_EXACTMATCH) &&
(match != BBR_RTT_BY_TIMESTAMP)){
/*
* We get a lot of rtt updates, lets not pay attention to
* any that are not an exact match. That way we don't have
* to worry about timestamps and the whole nonsense of
* unsure if its a retransmission etc (if we ever had the
* timestamp fixed to always have the last thing sent this
* would not be a issue).
*/
return;
}
if ((bbr_no_retran && bbr->rc_use_google) &&
(match != BBR_RTT_BY_EXACTMATCH) &&
(match != BBR_RTT_BY_TIMESTAMP)){
/*
* We only do measurements in google mode
* with bbr_no_retran on for sure things.
*/
return;
}
/* Only update srtt if we know by exact match */
tcp_bbr_xmit_timer(bbr, rtt, rsm_send_time, rsm->r_start, tsin);
if (ack_type == BBR_CUM_ACKED)
bbr->rc_ack_is_cumack = 1;
else
bbr->rc_ack_is_cumack = 0;
old_rttprop = bbr_get_rtt(bbr, BBR_RTT_PROP);
/*
* Note the following code differs to the original
* BBR spec. It calls for <= not <. However after a
* long discussion in email with Neal, he acknowledged
* that it should be < than so that we will have flows
* going into probe-rtt (we were seeing cases where that
* did not happen and caused ugly things to occur). We
* have added this agreed upon fix to our code base.
*/
if (rtt < old_rttprop) {
/* Update when we last saw a rtt drop */
bbr_log_rtt_shrinks(bbr, cts, 0, rtt, __LINE__, BBR_RTTS_NEWRTT, 0);
bbr_set_reduced_rtt(bbr, cts, __LINE__);
}
bbr_log_type_bbrrttprop(bbr, rtt, (rsm ? rsm->r_end : 0), uts, cts,
match, rsm->r_start, rsm->r_flags);
apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
if (old_rttprop != bbr_get_rtt(bbr, BBR_RTT_PROP)) {
/*
* The RTT-prop moved, reset the target (may be a
* nop for some states).
*/
bbr_set_state_target(bbr, __LINE__);
if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)
bbr_log_rtt_shrinks(bbr, cts, 0, 0,
__LINE__, BBR_RTTS_NEW_TARGET, 0);
else if (old_rttprop < bbr_get_rtt(bbr, BBR_RTT_PROP))
/* It went up */
bbr_check_probe_rtt_limits(bbr, cts);
}
if ((bbr->rc_use_google == 0) &&
(match == BBR_RTT_BY_TIMESTAMP)) {
/*
* We don't do b/w update with
* these since they are not really
* reliable.
*/
return;
}
if (bbr->r_ctl.r_app_limited_until &&
(bbr->r_ctl.rc_delivered >= bbr->r_ctl.r_app_limited_until)) {
/* We are no longer app-limited */
bbr->r_ctl.r_app_limited_until = 0;
}
if (bbr->rc_use_google) {
bbr_google_measurement(bbr, rsm, rtt, cts);
} else {
bbr_nf_measurement(bbr, rsm, rtt, cts);
}
}
/*
* Convert a timestamp that the main stack
* uses (milliseconds) into one that bbr uses
* (microseconds). Return that converted timestamp.
*/
static uint32_t
bbr_ts_convert(uint32_t cts) {
uint32_t sec, msec;
sec = cts / MS_IN_USEC;
msec = cts - (MS_IN_USEC * sec);
return ((sec * USECS_IN_SECOND) + (msec * MS_IN_USEC));
}
/*
* Return 0 if we did not update the RTT time, return
* 1 if we did.
*/
static int
bbr_update_rtt(struct tcpcb *tp, struct tcp_bbr *bbr,
struct bbr_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, uint32_t th_ack)
{
int32_t i;
uint32_t t, uts = 0;
if ((rsm->r_flags & BBR_ACKED) ||
(rsm->r_flags & BBR_WAS_RENEGED) ||
(rsm->r_flags & BBR_RXT_CLEARED)) {
/* Already done */
return (0);
}
if (rsm->r_rtr_cnt == 1) {
/*
* Only one transmit. Hopefully the normal case.
*/
if (TSTMP_GT(cts, rsm->r_tim_lastsent[0]))
t = cts - rsm->r_tim_lastsent[0];
else
t = 1;
if ((int)t <= 0)
t = 1;
bbr->r_ctl.rc_last_rtt = t;
bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
BBR_RTT_BY_EXACTMATCH, rsm->r_tim_lastsent[0], ack_type, to);
return (1);
}
/* Convert to usecs */
if ((bbr_can_use_ts_for_rtt == 1) &&
(bbr->rc_use_google == 1) &&
(ack_type == BBR_CUM_ACKED) &&
(to->to_flags & TOF_TS) &&
(to->to_tsecr != 0)) {
t = tcp_tv_to_mssectick(&bbr->rc_tv) - to->to_tsecr;
if (t < 1)
t = 1;
t *= MS_IN_USEC;
bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
BBR_RTT_BY_TIMESTAMP,
rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)],
ack_type, to);
return (1);
}
uts = bbr_ts_convert(to->to_tsecr);
if ((to->to_flags & TOF_TS) &&
(to->to_tsecr != 0) &&
(ack_type == BBR_CUM_ACKED) &&
((rsm->r_flags & BBR_OVERMAX) == 0)) {
/*
* Now which timestamp does it match? In this block the ACK
* may be coming from a previous transmission.
*/
uint32_t fudge;
fudge = BBR_TIMER_FUDGE;
for (i = 0; i < rsm->r_rtr_cnt; i++) {
if ((SEQ_GEQ(uts, (rsm->r_tim_lastsent[i] - fudge))) &&
(SEQ_LEQ(uts, (rsm->r_tim_lastsent[i] + fudge)))) {
if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
t = cts - rsm->r_tim_lastsent[i];
else
t = 1;
if ((int)t <= 0)
t = 1;
bbr->r_ctl.rc_last_rtt = t;
bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_TSMATCHING,
rsm->r_tim_lastsent[i], ack_type, to);
if ((i + 1) < rsm->r_rtr_cnt) {
/* Likely */
bbr_earlier_retran(tp, bbr, rsm, t, cts, ack_type);
} else if (rsm->r_flags & BBR_TLP) {
bbr->rc_tlp_rtx_out = 0;
}
return (1);
}
}
/* Fall through if we can't find a matching timestamp */
}
/*
* 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.
*
* Lets look at the last retransmit and see what we can tell
* (with BBR for space we only keep 2 note we have to keep
* at least 2 so the map can not be condensed more).
*/
i = rsm->r_rtr_cnt - 1;
if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
t = cts - rsm->r_tim_lastsent[i];
else
goto not_sure;
if (t < bbr->r_ctl.rc_lowest_rtt) {
/*
* We retransmitted and the ack came back in less
* than the smallest rtt we have observed in the
* windowed rtt. We most likey did an improper
* retransmit as outlined in 4.2 Step 3 point 2 in
* the rack-draft.
*
* Use the prior transmission to update all the
* information as long as there is only one prior
* transmission.
*/
if ((rsm->r_flags & BBR_OVERMAX) == 0) {
#ifdef BBR_INVARIANTS
if (rsm->r_rtr_cnt == 1)
panic("rsm:%p bbr:%p rsm has overmax and only 1 retranmit flags:%x?", rsm, bbr, rsm->r_flags);
#endif
i = rsm->r_rtr_cnt - 2;
if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
t = cts - rsm->r_tim_lastsent[i];
else
t = 1;
bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_EARLIER_RET,
rsm->r_tim_lastsent[i], ack_type, to);
bbr_earlier_retran(tp, bbr, rsm, t, cts, ack_type);
} else {
/*
* Too many prior transmissions, just
* updated BBR delivered
*/
not_sure:
bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
}
} else {
/*
* We retransmitted it and the retransmit did the
* job.
*/
if (rsm->r_flags & BBR_TLP)
bbr->rc_tlp_rtx_out = 0;
if ((rsm->r_flags & BBR_OVERMAX) == 0)
bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts,
BBR_RTT_BY_THIS_RETRAN, 0, ack_type, to);
else
bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
return (1);
}
return (0);
}
/*
* Mark the SACK_PASSED flag on all entries prior to rsm send wise.
*/
static void
bbr_log_sack_passed(struct tcpcb *tp,
struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
{
struct bbr_sendmap *nrsm;
nrsm = rsm;
TAILQ_FOREACH_REVERSE_FROM(nrsm, &bbr->r_ctl.rc_tmap,
bbr_head, r_tnext) {
if (nrsm == rsm) {
/* Skip orginal segment he is acked */
continue;
}
if (nrsm->r_flags & BBR_ACKED) {
/* Skip ack'd segments */
continue;
}
if (nrsm->r_flags & BBR_SACK_PASSED) {
/*
* We found one that is already marked
* passed, we have been here before and
* so all others below this are marked.
*/
break;
}
BBR_STAT_INC(bbr_sack_passed);
nrsm->r_flags |= BBR_SACK_PASSED;
if (((nrsm->r_flags & BBR_MARKED_LOST) == 0) &&
bbr_is_lost(bbr, nrsm, bbr->r_ctl.rc_rcvtime)) {
bbr->r_ctl.rc_lost += nrsm->r_end - nrsm->r_start;
bbr->r_ctl.rc_lost_bytes += nrsm->r_end - nrsm->r_start;
nrsm->r_flags |= BBR_MARKED_LOST;
}
nrsm->r_flags &= ~BBR_WAS_SACKPASS;
}
}
/*
* Returns the number of bytes that were
* newly ack'd by sack blocks.
*/
static uint32_t
bbr_proc_sack_blk(struct tcpcb *tp, struct tcp_bbr *bbr, struct sackblk *sack,
struct tcpopt *to, struct bbr_sendmap **prsm, uint32_t cts)
{
int32_t times = 0;
uint32_t start, end, maxseg, changed = 0;
struct bbr_sendmap *rsm, *nrsm;
int32_t used_ref = 1;
uint8_t went_back = 0, went_fwd = 0;
maxseg = tp->t_maxseg - bbr->rc_last_options;
start = sack->start;
end = sack->end;
rsm = *prsm;
if (rsm == NULL)
used_ref = 0;
/* Do we locate the block behind where we last were? */
if (rsm && SEQ_LT(start, rsm->r_start)) {
went_back = 1;
TAILQ_FOREACH_REVERSE_FROM(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
if (SEQ_GEQ(start, rsm->r_start) &&
SEQ_LT(start, rsm->r_end)) {
goto do_rest_ofb;
}
}
}
start_at_beginning:
went_fwd = 1;
/*
* Ok lets locate the block where this guy is fwd from rsm (if its
* set)
*/
TAILQ_FOREACH_FROM(rsm, &bbr->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(&bbr->r_ctl.rc_map, bbr_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 BBR_INVARIANTS
panic("tp:%p bbr:%p sack:%p to:%p prsm:%p",
tp, bbr, sack, to, prsm);
#else
goto out;
#endif
}
times++;
BBR_STAT_INC(bbr_sack_proc_restart);
rsm = NULL;
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.
*/
if (bbr_sack_mergable(rsm, start, end))
nrsm = bbr_alloc_full_limit(bbr);
else
nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* We could not allocate ignore the sack */
struct sackblk blk;
blk.start = start;
blk.end = end;
sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
goto out;
}
bbr_clone_rsm(bbr, nrsm, rsm, start);
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~BBR_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 & BBR_ACKED) == 0) {
bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
changed += (rsm->r_end - rsm->r_start);
bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
bbr_log_sack_passed(tp, bbr, rsm);
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
}
/* Is Reordering occuring? */
if (rsm->r_flags & BBR_SACK_PASSED) {
BBR_STAT_INC(bbr_reorder_seen);
bbr->r_ctl.rc_reorder_ts = cts;
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
/* LT sampling also needs adjustment */
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
}
rsm->r_flags |= BBR_ACKED;
rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
}
bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
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;
}
if (rsm->r_flags & BBR_ACKED) {
/* Been here done that */
goto out;
}
/* Ok we need to split off this one at the tail */
if (bbr_sack_mergable(rsm, start, end))
nrsm = bbr_alloc_full_limit(bbr);
else
nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* failed XXXrrs what can we do but loose the sack info? */
struct sackblk blk;
blk.start = start;
blk.end = end;
sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
goto out;
}
/* Clone it */
bbr_clone_rsm(bbr, nrsm, rsm, end);
/* The sack block does not cover this guy fully */
rsm->r_flags &= (~BBR_HAS_FIN);
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
nrsm->r_dupack = 0;
bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
changed += (rsm->r_end - rsm->r_start);
bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
bbr_log_sack_passed(tp, bbr, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
}
if (rsm->r_flags & BBR_SACK_PASSED) {
BBR_STAT_INC(bbr_reorder_seen);
bbr->r_ctl.rc_reorder_ts = cts;
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
/* LT sampling also needs adjustment */
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
}
rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
rsm->r_flags |= BBR_ACKED;
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
out:
if (rsm && (rsm->r_flags & BBR_ACKED)) {
/*
* Now can we merge this newly acked
* block with either the previous or
* next block?
*/
nrsm = TAILQ_NEXT(rsm, r_next);
if (nrsm &&
(nrsm->r_flags & BBR_ACKED)) {
/* yep this and next can be merged */
rsm = bbr_merge_rsm(bbr, rsm, nrsm);
}
/* Now what about the previous? */
nrsm = TAILQ_PREV(rsm, bbr_head, r_next);
if (nrsm &&
(nrsm->r_flags & BBR_ACKED)) {
/* yep the previous and this can be merged */
rsm = bbr_merge_rsm(bbr, nrsm, rsm);
}
}
if (used_ref == 0) {
BBR_STAT_INC(bbr_sack_proc_all);
} else {
BBR_STAT_INC(bbr_sack_proc_short);
}
if (went_fwd && went_back) {
BBR_STAT_INC(bbr_sack_search_both);
} else if (went_fwd) {
BBR_STAT_INC(bbr_sack_search_fwd);
} else if (went_back) {
BBR_STAT_INC(bbr_sack_search_back);
}
/* Save off where the next seq is */
if (rsm)
bbr->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
else
bbr->r_ctl.rc_sacklast = NULL;
*prsm = rsm;
return (changed);
}
static void inline
bbr_peer_reneges(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, tcp_seq th_ack)
{
struct bbr_sendmap *tmap;
BBR_STAT_INC(bbr_reneges_seen);
tmap = NULL;
while (rsm && (rsm->r_flags & BBR_ACKED)) {
/* Its no longer sacked, mark it so */
uint32_t oflags;
bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
#ifdef BBR_INVARIANTS
if (rsm->r_in_tmap) {
panic("bbr:%p rsm:%p flags:0x%x in tmap?",
bbr, rsm, rsm->r_flags);
}
#endif
oflags = rsm->r_flags;
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
/* LT sampling also needs adjustment */
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS | BBR_MARKED_LOST);
rsm->r_flags |= BBR_WAS_RENEGED;
rsm->r_flags |= BBR_RXT_CLEARED;
bbr_log_type_rsmclear(bbr, bbr->r_ctl.rc_rcvtime, rsm, oflags, __LINE__);
/* Rebuild it into our tmap */
if (tmap == NULL) {
TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
tmap = rsm;
} else {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, tmap, rsm, r_tnext);
tmap = rsm;
}
tmap->r_in_tmap = 1;
/*
* XXXrrs Delivered? Should we do anything here?
*
* Of course we don't on a rxt timeout so maybe its ok that
* we don't?
*
* For now lets not.
*/
rsm = TAILQ_NEXT(rsm, r_next);
}
/*
* Now lets possibly clear the sack filter so we start recognizing
* sacks that cover this area.
*/
sack_filter_clear(&bbr->r_ctl.bbr_sf, th_ack);
}
static void
bbr_log_syn(struct tcpcb *tp, struct tcpopt *to)
{
struct tcp_bbr *bbr;
struct bbr_sendmap *rsm;
uint32_t cts;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
cts = bbr->r_ctl.rc_rcvtime;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
if (rsm && (rsm->r_flags & BBR_HAS_SYN)) {
if ((rsm->r_end - rsm->r_start) <= 1) {
/* Log out the SYN completely */
bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
if (bbr->r_ctl.rc_next == rsm) {
/* scoot along the marker */
bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
}
if (to != NULL)
bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, 0);
bbr_free(bbr, rsm);
} else {
/* There is more (Fast open)? strip out SYN. */
rsm->r_flags &= ~BBR_HAS_SYN;
rsm->r_start++;
}
}
}
/*
* Returns the number of bytes that were
* acknowledged by SACK blocks.
*/
static uint32_t
bbr_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
uint32_t *prev_acked)
{
uint32_t changed, last_seq, entered_recovery = 0;
struct tcp_bbr *bbr;
struct bbr_sendmap *rsm;
struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
register uint32_t th_ack;
int32_t i, j, k, new_sb, num_sack_blks = 0;
uint32_t cts, acked, ack_point, sack_changed = 0;
uint32_t p_maxseg, maxseg, p_acked = 0;
INP_WLOCK_ASSERT(tp->t_inpcb);
if (th->th_flags & TH_RST) {
/* We don't log resets */
return (0);
}
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
cts = bbr->r_ctl.rc_rcvtime;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
changed = 0;
maxseg = tp->t_maxseg - bbr->rc_last_options;
p_maxseg = min(bbr->r_ctl.rc_pace_max_segs, maxseg);
th_ack = th->th_ack;
if (SEQ_GT(th_ack, tp->snd_una)) {
acked = th_ack - tp->snd_una;
bbr_log_progress_event(bbr, tp, ticks, PROGRESS_UPDATE, __LINE__);
bbr->rc_tp->t_acktime = ticks;
} else
acked = 0;
if (SEQ_LEQ(th_ack, tp->snd_una)) {
/* Only sent here for sack processing */
goto proc_sack;
}
if (rsm && SEQ_GT(th_ack, rsm->r_start)) {
changed = th_ack - rsm->r_start;
} else if ((rsm == NULL) && ((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.
*/
if ((to->to_flags & TOF_TS) && (to->to_tsecr != 0)) {
/*
* We have a timestamp that can be used to generate
* an initial RTT.
*/
uint32_t ts, now, rtt;
ts = bbr_ts_convert(to->to_tsecr);
now = bbr_ts_convert(tcp_tv_to_mssectick(&bbr->rc_tv));
rtt = now - ts;
if (rtt < 1)
rtt = 1;
bbr_log_type_bbrrttprop(bbr, rtt,
tp->iss, 0, cts,
BBR_RTT_BY_TIMESTAMP, tp->iss, 0);
apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
changed = 1;
bbr->r_wanted_output = 1;
goto out;
}
goto proc_sack;
} else if (rsm == NULL) {
goto out;
}
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.
*/
bbr->r_wanted_output = 1;
more:
if (rsm == NULL) {
if (tp->t_flags & TF_SENTFIN) {
/* if we send a FIN we will not hav a map */
goto proc_sack;
}
#ifdef BBR_INVARIANTS
panic("No rack map tp:%p for th:%p state:%d bbr:%p snd_una:%u snd_max:%u chg:%d\n",
tp,
th, tp->t_state, bbr,
tp->snd_una, tp->snd_max, changed);
#endif
goto proc_sack;
}
}
if (SEQ_LT(th_ack, rsm->r_start)) {
/* Huh map is missing this */
#ifdef BBR_INVARIANTS
printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d bbr:%p\n",
rsm->r_start,
th_ack, tp->t_state,
bbr->r_state, bbr);
panic("th-ack is bad bbr:%p tp:%p", bbr, tp);
#endif
goto proc_sack;
} else if (th_ack == rsm->r_start) {
/* None here to ack */
goto proc_sack;
}
/*
* Clear the dup ack counter, it will
* either be freed or if there is some
* remaining we need to start it at zero.
*/
rsm->r_dupack = 0;
/* Now do we consume the whole thing? */
if (SEQ_GEQ(th_ack, rsm->r_end)) {
/* Its all consumed. */
uint32_t left;
if (rsm->r_flags & BBR_ACKED) {
/*
* It was acked on the scoreboard -- remove it from
* total
*/
p_acked += (rsm->r_end - rsm->r_start);
bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
if (bbr->r_ctl.rc_sacked == 0)
bbr->r_ctl.rc_sacklast = NULL;
} else {
bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, th_ack);
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
}
if (rsm->r_flags & BBR_SACK_PASSED) {
/*
* There are acked segments ACKED on the
* scoreboard further up. We are seeing
* reordering.
*/
BBR_STAT_INC(bbr_reorder_seen);
bbr->r_ctl.rc_reorder_ts = cts;
if (rsm->r_flags & BBR_MARKED_LOST) {
bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
/* LT sampling also needs adjustment */
bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
}
}
rsm->r_flags &= ~BBR_MARKED_LOST;
}
bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
if (bbr->r_ctl.rc_next == rsm) {
/* scoot along the marker */
bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
}
bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
/* Adjust the packet counts */
left = th_ack - rsm->r_end;
/* Free back to zone */
bbr_free(bbr, rsm);
if (left) {
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
goto more;
}
goto proc_sack;
}
if (rsm->r_flags & BBR_ACKED) {
/*
* It was acked on the scoreboard -- remove it from total
* for the part being cum-acked.
*/
p_acked += (rsm->r_end - rsm->r_start);
bbr->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
if (bbr->r_ctl.rc_sacked == 0)
bbr->r_ctl.rc_sacklast = NULL;
} else {
/*
* It was acked up to th_ack point for the first time
*/
struct bbr_sendmap lrsm;
memcpy(&lrsm, rsm, sizeof(struct bbr_sendmap));
lrsm.r_end = th_ack;
bbr_update_rtt(tp, bbr, &lrsm, to, cts, BBR_CUM_ACKED, th_ack);
}
if ((rsm->r_flags & BBR_MARKED_LOST) &&
((rsm->r_flags & BBR_ACKED) == 0)) {
/*
* It was marked lost and partly ack'd now
* for the first time. We lower the rc_lost_bytes
* and still leave it MARKED.
*/
bbr->r_ctl.rc_lost_bytes -= th_ack - rsm->r_start;
}
bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
/* adjust packet count */
rsm->r_start = th_ack;
proc_sack:
/* Check for reneging */
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
if (rsm && (rsm->r_flags & BBR_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.
*/
bbr_peer_reneges(bbr, rsm, th->th_ack);
}
if ((to->to_flags & TOF_SACK) == 0) {
/* We are done nothing left to log */
goto out;
}
rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_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 ((bbr->r_ctl.rc_num_small_maps_alloced > bbr_sack_block_limit) &&
(SEQ_LT(sack.end, last_seq)) &&
((sack.end - sack.start) < (p_maxseg / 8))) {
/*
* Not the last piece and its smaller than
* 1/8th of a p_maxseg. We ignore this.
*/
BBR_STAT_INC(bbr_runt_sacks);
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.
*/
new_sb = sack_filter_blks(&bbr->r_ctl.bbr_sf, sack_blocks,
num_sack_blks, th->th_ack);
ctf_log_sack_filter(bbr->rc_tp, new_sb, sack_blocks);
BBR_STAT_ADD(bbr_sack_blocks, num_sack_blks);
BBR_STAT_ADD(bbr_sack_blocks_skip, (num_sack_blks - new_sb));
num_sack_blks = new_sb;
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 = bbr->r_ctl.rc_sacklast;
for (i = 0; i < num_sack_blks; i++) {
acked = bbr_proc_sack_blk(tp, bbr, &sack_blocks[i], to, &rsm, cts);
if (acked) {
bbr->r_wanted_output = 1;
changed += acked;
sack_changed += acked;
}
}
out:
*prev_acked = p_acked;
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 bbr_sendmap *rsm;
rsm = bbr_check_recovery_mode(tp, bbr, cts);
if (rsm) {
/* Enter recovery */
entered_recovery = 1;
bbr->r_wanted_output = 1;
/*
* When we enter recovery we need to assure we send
* one packet.
*/
if (bbr->r_ctl.rc_resend == NULL) {
bbr->r_ctl.rc_resend = rsm;
}
}
}
if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
/*
* See if we need to rack-retransmit anything if so set it
* up as the thing to resend assuming something else is not
* already in that position.
*/
if (bbr->r_ctl.rc_resend == NULL) {
bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
}
}
/*
* We return the amount that changed via sack, this is used by the
* ack-received code to augment what was changed between th_ack <->
* snd_una.
*/
return (sack_changed);
}
static void
bbr_strike_dupack(struct tcp_bbr *bbr)
{
struct bbr_sendmap *rsm;
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
if (rsm && (rsm->r_dupack < 0xff)) {
rsm->r_dupack++;
if (rsm->r_dupack >= DUP_ACK_THRESHOLD)
bbr->r_wanted_output = 1;
}
}
/*
* Return value of 1, we do not need to call bbr_process_data().
* return value of 0, bbr_process_data can be called.
* For ret_val if its 0 the TCB is locked and valid, if its non-zero
* its unlocked and probably unsafe to touch the TCB.
*/
static int
bbr_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 acked_amount;
uint16_t nsegs;
int32_t acked;
uint32_t lost, sack_changed = 0;
struct mbuf *mfree;
struct tcp_bbr *bbr;
uint32_t prev_acked = 0;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
lost = bbr->r_ctl.rc_lost;
nsegs = max(1, m->m_pkthdr.lro_nsegs);
if (SEQ_GT(th->th_ack, tp->snd_max)) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
bbr->r_wanted_output = 1;
return (1);
}
if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
/* Process the ack */
if (bbr->rc_in_persist)
tp->t_rxtshift = 0;
if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
bbr_strike_dupack(bbr);
sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
}
bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, (bbr->r_ctl.rc_lost > lost));
if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
/*
* Old ack, behind the last one rcv'd or a duplicate ack
* with SACK info.
*/
if (th->th_ack == tp->snd_una) {
bbr_ack_received(tp, bbr, th, 0, sack_changed, prev_acked, __LINE__, 0);
if (bbr->r_state == TCPS_SYN_SENT) {
/*
* Special case on where we sent SYN. When
* the SYN-ACK is processed in syn_sent
* state it bumps the snd_una. This causes
* us to hit here even though we did ack 1
* byte.
*
* Go through the nothing left case so we
* send data.
*/
goto nothing_left;
}
}
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. */
}
}
INP_WLOCK_ASSERT(tp->t_inpcb);
acked = BYTES_THIS_ACK(tp, th);
TCPSTAT_ADD(tcps_rcvackpack, (int)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)
bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
}
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);
/* NB: sowwakeup_locked() does an implicit unlock. */
sowwakeup_locked(so);
m_freem(mfree);
if (SEQ_GT(th->th_ack, tp->snd_una)) {
bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
}
tp->snd_una = th->th_ack;
bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, (bbr->r_ctl.rc_lost - lost));
if (IN_RECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover) &&
(SEQ_LT(th->th_ack, tp->snd_max))) {
tcp_bbr_partialack(tp);
} else {
bbr_post_recovery(tp);
}
}
if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
tp->snd_recover = tp->snd_una;
}
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
tp->snd_nxt = tp->snd_max;
}
if (tp->snd_una == tp->snd_max) {
/* Nothing left outstanding */
nothing_left:
bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
bbr->rc_tp->t_acktime = 0;
if ((sbused(&so->so_snd) == 0) &&
(tp->t_flags & TF_SENTFIN)) {
ourfinisacked = 1;
}
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
if (bbr->rc_in_persist == 0) {
bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
}
sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
/*
* We invalidate the last ack here since we
* don't want to transfer forward the time
* for our sum's calculations.
*/
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);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
BBR_STAT_INC(bbr_dropped_af_data);
return (1);
}
/* Set need output so persist might get set */
bbr->r_wanted_output = 1;
}
if (ofia)
*ofia = ourfinisacked;
return (0);
}
static void
bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
if (bbr->rc_in_persist == 0) {
bbr_timer_cancel(bbr, __LINE__, cts);
bbr->r_ctl.rc_last_delay_val = 0;
tp->t_rxtshift = 0;
bbr->rc_in_persist = 1;
bbr->r_ctl.rc_went_idle_time = cts;
/* We should be capped when rw went to 0 but just in case */
bbr_log_type_pesist(bbr, cts, 0, line, 1);
/* Time freezes for the state, so do the accounting now */
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
uint32_t time_in;
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
int32_t idx;
idx = bbr_state_val(bbr);
counter_u64_add(bbr_state_time[(idx + 5)], time_in);
} else {
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
}
}
bbr->r_ctl.rc_bbr_state_time = cts;
}
}
static void
bbr_restart_after_idle(struct tcp_bbr *bbr, uint32_t cts, uint32_t idle_time)
{
/*
* Note that if idle time does not exceed our
* threshold, we do nothing continuing the state
* transitions we were last walking through.
*/
if (idle_time >= bbr_idle_restart_threshold) {
if (bbr->rc_use_idle_restart) {
bbr->rc_bbr_state = BBR_STATE_IDLE_EXIT;
/*
* Set our target using BBR_UNIT, so
* we increase at a dramatic rate but
* we stop when we get the pipe
* full again for our current b/w estimate.
*/
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
bbr_set_state_target(bbr, __LINE__);
/* Now setup our gains to ramp up */
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
bbr_log_type_statechange(bbr, cts, __LINE__);
} else {
bbr_substate_change(bbr, cts, __LINE__, 1);
}
}
}
static void
bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
uint32_t idle_time;
if (bbr->rc_in_persist == 0)
return;
idle_time = bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time);
bbr->rc_in_persist = 0;
bbr->rc_hit_state_1 = 0;
tp->t_flags &= ~TF_FORCEDATA;
bbr->r_ctl.rc_del_time = cts;
/*
* We invalidate the last ack here since we
* don't want to transfer forward the time
* for our sum's calculations.
*/
if (bbr->rc_inp->inp_in_hpts) {
tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
bbr->rc_timer_first = 0;
bbr->r_ctl.rc_hpts_flags = 0;
bbr->r_ctl.rc_last_delay_val = 0;
bbr->r_ctl.rc_hptsi_agg_delay = 0;
bbr->r_agg_early_set = 0;
bbr->r_ctl.rc_agg_early = 0;
}
bbr_log_type_pesist(bbr, cts, idle_time, line, 0);
if (idle_time >= bbr_rtt_probe_time) {
/*
* This qualifies as a RTT_PROBE session since we drop the
* data outstanding to nothing and waited more than
* bbr_rtt_probe_time.
*/
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_PERSIST, 0);
bbr->r_ctl.last_in_probertt = bbr->r_ctl.rc_rtt_shrinks = cts;
}
tp->t_rxtshift = 0;
/*
* If in probeBW and we have persisted more than an RTT lets do
* special handling.
*/
/* Force a time based epoch */
bbr_set_epoch(bbr, cts, __LINE__);
/*
* Setup the lost so we don't count anything against the guy
* we have been stuck with during persists.
*/
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
/* Time un-freezes for the state */
bbr->r_ctl.rc_bbr_state_time = cts;
if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) ||
(bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)) {
/*
* If we are going back to probe-bw
* or probe_rtt, we may need to possibly
* do a fast restart.
*/
bbr_restart_after_idle(bbr, cts, idle_time);
}
}
static void
bbr_collapsed_window(struct tcp_bbr *bbr)
{
/*
* Now we must walk the
* send map and divide the
* ones left stranded. These
* guys can't cause us to abort
* the connection and are really
* "unsent". However if a buggy
* client actually did keep some
* of the data i.e. collapsed the win
* and refused to ack and then opened
* the win and acked that data. We would
* get into an ack war, the simplier
* method then of just pretending we
* did not send those segments something
* won't work.
*/
struct bbr_sendmap *rsm, *nrsm;
tcp_seq max_seq;
uint32_t maxseg;
int can_split = 0;
int fnd = 0;
maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
max_seq = bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd;
bbr_log_type_rwnd_collapse(bbr, max_seq, 1, 0);
TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
/* Find the first seq past or at maxseq */
if (rsm->r_flags & BBR_RWND_COLLAPSED)
rsm->r_flags &= ~BBR_RWND_COLLAPSED;
if (SEQ_GEQ(max_seq, rsm->r_start) &&
SEQ_GEQ(rsm->r_end, max_seq)) {
fnd = 1;
break;
}
}
bbr->rc_has_collapsed = 0;
if (!fnd) {
/* Nothing to do strange */
return;
}
/*
* Now can we split?
*
* We don't want to split if splitting
* would generate too many small segments
* less we let an attacker fragment our
* send_map and leave us out of memory.
*/
if ((max_seq != rsm->r_start) &&
(max_seq != rsm->r_end)){
/* can we split? */
int res1, res2;
res1 = max_seq - rsm->r_start;
res2 = rsm->r_end - max_seq;
if ((res1 >= (maxseg/8)) &&
(res2 >= (maxseg/8))) {
/* No small pieces here */
can_split = 1;
} else if (bbr->r_ctl.rc_num_small_maps_alloced < bbr_sack_block_limit) {
/* We are under the limit */
can_split = 1;
}
}
/* Ok do we need to split this rsm? */
if (max_seq == rsm->r_start) {
/* It's this guy no split required */
nrsm = rsm;
} else if (max_seq == rsm->r_end) {
/* It's the next one no split required. */
nrsm = TAILQ_NEXT(rsm, r_next);
if (nrsm == NULL) {
/* Huh? */
return;
}
} else if (can_split && SEQ_LT(max_seq, rsm->r_end)) {
/* yep we need to split it */
nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* failed XXXrrs what can we do mark the whole? */
nrsm = rsm;
goto no_split;
}
/* Clone it */
bbr_log_type_rwnd_collapse(bbr, max_seq, 3, 0);
bbr_clone_rsm(bbr, nrsm, rsm, max_seq);
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
} else {
/*
* Split not allowed just start here just
* use this guy.
*/
nrsm = rsm;
}
no_split:
BBR_STAT_INC(bbr_collapsed_win);
/* reuse fnd as a count */
fnd = 0;
TAILQ_FOREACH_FROM(nrsm, &bbr->r_ctl.rc_map, r_next) {
nrsm->r_flags |= BBR_RWND_COLLAPSED;
fnd++;
bbr->rc_has_collapsed = 1;
}
bbr_log_type_rwnd_collapse(bbr, max_seq, 4, fnd);
}
static void
bbr_un_collapse_window(struct tcp_bbr *bbr)
{
struct bbr_sendmap *rsm;
int cleared = 0;
TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
if (rsm->r_flags & BBR_RWND_COLLAPSED) {
/* Clear the flag */
rsm->r_flags &= ~BBR_RWND_COLLAPSED;
cleared++;
} else
break;
}
bbr_log_type_rwnd_collapse(bbr,
(bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd), 0, cleared);
bbr->rc_has_collapsed = 0;
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCB is still
* locked.
*/
static int
bbr_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.
*/
uint16_t nsegs;
int32_t tfo_syn;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)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;
bbr->r_wanted_output = 1;
} else if (thflags & TH_ACK) {
if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
tp->snd_wl2 = th->th_ack;
}
}
if (tp->snd_wnd < ctf_outstanding(tp))
/* The peer collapsed its window on us */
bbr_collapsed_window(bbr);
else if (bbr->rc_has_collapsed)
bbr_un_collapse_window(bbr);
/* Was persist timer active and now we have window space? */
if ((bbr->rc_in_persist != 0) &&
(tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
bbr_minseg(bbr)))) {
/*
* Make the rate persist at end of persist mode if idle long
* enough
*/
bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
/* Make sure we output to start the timer */
bbr->r_wanted_output = 1;
}
/* Do we need to enter persist? */
if ((bbr->rc_in_persist == 0) &&
(tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/* No send window.. we must enter persist */
bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
}
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;
tcp_seq save_rnxt = tp->rcv_nxt;
int save_tlen = tlen;
m_adj(m, drop_hdrlen); /* delayed header drop */
/*
* Insert segment which includes th into TCP reassembly
* queue with control block tp. Set thflags to whether
* reassembly now includes a segment with FIN. This handles
* the common case inline (segment is the next to be
* received on an established connection, and the queue is
* empty), avoiding linkage into and removal from the queue
* and repetition of various conversions. Set DELACK for
* segments received in order, but ack immediately when
* segments are out of order (so fast retransmit can work).
*/
if (th->th_seq == tp->rcv_nxt &&
SEGQ_EMPTY(tp) &&
(TCPS_HAVEESTABLISHED(tp->t_state) ||
tfo_syn)) {
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (0);
}
}
#endif
if (DELAY_ACK(tp, bbr, nsegs) || tfo_syn) {
bbr->bbr_segs_rcvd += max(1, nsegs);
tp->t_flags |= TF_DELACK;
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
} else {
bbr->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
}
tp->rcv_nxt += tlen;
thflags = th->th_flags & TH_FIN;
TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
TCPSTAT_ADD(tcps_rcvbyte, tlen);
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
m_freem(m);
else
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && appended != mcnt)
counter_fo_release(so->so_rcv.sb_shlim,
mcnt - appended);
#endif
} else {
/*
* XXX: Due to the header drop above "th" is
* theoretically invalid by now. Fortunately
* m_adj() doesn't actually frees any mbufs when
* trimming from the head.
*/
tcp_seq temp = save_start;
thflags = tcp_reass(tp, th, &temp, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) {
if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
/*
* DSACK actually handled in the fastpath
* above.
*/
tcp_update_sack_list(tp, save_start,
save_start + save_tlen);
} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
if ((tp->rcv_numsacks >= 1) &&
(tp->sackblks[0].end == save_start)) {
/*
* Partial overlap, recorded at todrop
* above.
*/
tcp_update_sack_list(tp,
tp->sackblks[0].start,
tp->sackblks[0].end);
} else {
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
}
} else if (tlen >= save_tlen) {
/* Update of sackblks. */
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
} else if (tlen > 0) {
tcp_update_dsack_list(tp, save_start,
save_start + tlen);
}
}
} else {
m_freem(m);
thflags &= ~TH_FIN;
}
/*
* If FIN is received ACK the FIN and let the user know that the
* connection is closing.
*/
if (thflags & TH_FIN) {
if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
socantrcvmore(so);
/*
* If connection is half-synchronized (ie NEEDSYN
* flag on) then delay ACK, so it may be piggybacked
* when SYN is sent. Otherwise, since we received a
* FIN then no more input can be expected, send ACK
* now.
*/
if (tp->t_flags & TF_NEEDSYN) {
tp->t_flags |= TF_DELACK;
bbr_timer_cancel(bbr,
__LINE__, bbr->r_ctl.rc_rcvtime);
} 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:
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:
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:
bbr->rc_timer_first = 1;
bbr_timer_cancel(bbr,
__LINE__, bbr->r_ctl.rc_rcvtime);
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(tp->t_inpcb);
tcp_twstart(tp);
return (1);
}
}
/*
* Return any desired output.
*/
if ((tp->t_flags & TF_ACKNOW) ||
(sbavail(&so->so_snd) > ctf_outstanding(tp))) {
bbr->r_wanted_output = 1;
}
INP_WLOCK_ASSERT(tp->t_inpcb);
return (0);
}
/*
* Here nothing is really faster, its just that we
* have broken out the fast-data path also just like
* the fast-ack. Return 1 if we processed the packet
* return 0 if you need to take the "slow-path".
*/
static int
bbr_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)
{
uint16_t nsegs;
int32_t newsize = 0; /* automatic sockbuf scaling */
struct tcp_bbr *bbr;
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
#endif
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.
*/
u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;
short ostate = 0;
#endif
/* On the hpts and we would have called output */
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
/*
* 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 (bbr->r_ctl.rc_resend != NULL) {
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_tv_to_mssectick(&bbr->rc_tv);
tp->ts_recent = to->to_tsval;
}
/*
* This is a pure, in-sequence data packet with nothing on the
* reassembly queue and we have enough buffer space to take it.
*/
nsegs = max(1, m->m_pkthdr.lro_nsegs);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (1);
}
}
#endif
/* Clean receiver SACK report if present */
if (tp->rcv_numsacks)
tcp_clean_sackreport(tp);
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, (int)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 */
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
ctf_calc_rwin(so, tp);
}
/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && mcnt != appended)
counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
#endif
if (DELAY_ACK(tp, bbr, nsegs)) {
bbr->bbr_segs_rcvd += max(1, nsegs);
tp->t_flags |= TF_DELACK;
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
} else {
bbr->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
}
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. If we return 1, then all is well and
* the packet is fully processed.
*/
static int
bbr_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)
{
int32_t acked;
uint16_t nsegs;
uint32_t sack_changed;
#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
uint32_t prev_acked = 0;
struct tcp_bbr *bbr;
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(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);
}
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
if (__predict_false(bbr->r_ctl.rc_resend != NULL)) {
/* We are retransmitting */
return (0);
}
if (__predict_false(bbr->rc_in_persist != 0)) {
/* In persist mode */
return (0);
}
if (bbr->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);
sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
/*
* We never detect loss in fast ack [we can't
* have a sack and can't be in recovery so
* we always pass 0 (nothing detected)].
*/
bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, 0);
/* Did the window get updated? */
if (tiwin != tp->snd_wnd) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
}
/* Do we need to exit persists? */
if ((bbr->rc_in_persist != 0) &&
(tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
bbr_minseg(bbr)))) {
bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
bbr->r_wanted_output = 1;
}
/* Do we need to enter persists? */
if ((bbr->rc_in_persist == 0) &&
(tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/* No send window.. we must enter persist */
bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
}
/*
* 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 = bbr->r_ctl.rc_rcvtime;
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)
bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
}
/*
* 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, (int)nsegs);
TCPSTAT_ADD(tcps_rcvackbyte, acked);
sbdrop(&so->so_snd, acked);
if (SEQ_GT(th->th_ack, tp->snd_una))
bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
tp->snd_una = th->th_ack;
if (tp->snd_wnd < ctf_outstanding(tp))
/* The peer collapsed its window on us */
bbr_collapsed_window(bbr);
else if (bbr->rc_has_collapsed)
bbr_un_collapse_window(bbr);
if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
tp->snd_recover = tp->snd_una;
}
bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, 0);
/*
* Pull snd_wl2 up to prevent seq wrap relative to th_ack.
*/
tp->snd_wl2 = th->th_ack;
m_freem(m);
/*
* 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
/* Wake up the socket if we have room to write more */
sowwakeup(so);
if (tp->snd_una == tp->snd_max) {
/* Nothing left outstanding */
bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
bbr->rc_tp->t_acktime = 0;
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
if (bbr->rc_in_persist == 0) {
bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
}
sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
/*
* We invalidate the last ack here since we
* don't want to transfer forward the time
* for our sum's calculations.
*/
bbr->r_wanted_output = 1;
}
if (sbavail(&so->so_snd)) {
bbr->r_wanted_output = 1;
}
return (1);
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCB is still
* locked.
*/
static int
bbr_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 todrop;
int32_t ourfinisacked = 0;
struct tcp_bbr *bbr;
int32_t ret_val = 0;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
/*
* If the state is SYN_SENT: if seg contains an ACK, but not for our
* SYN, drop the input. if seg contains a RST, then drop the
* connection. if seg does not contain SYN, then drop it. Otherwise
* this is an acceptable SYN segment initialize tp->rcv_nxt and
* tp->irs if seg contains ack then advance tp->snd_una. BRR does
* not support ECN so we will not say we are 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))) {
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
TCP_PROBE5(connect__refused, NULL, tp,
mtod(m, const char *), tp, th);
tp = tcp_drop(tp, ECONNREFUSED);
ctf_do_drop(m, tp);
return (1);
}
if (thflags & TH_RST) {
ctf_do_drop(m, tp);
return (1);
}
if (!(thflags & TH_SYN)) {
ctf_do_drop(m, tp);
return (1);
}
tp->irs = th->th_seq;
tcp_rcvseqinit(tp);
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, bbr, 1) && tlen != 0 && (tfo_partial == 0)) {
bbr->bbr_segs_rcvd += 1;
tp->t_flags |= TF_DELACK;
bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
} else {
bbr->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
}
if (SEQ_GT(th->th_ack, tp->iss)) {
/*
* The SYN is acked
* handle it specially.
*/
bbr_log_syn(tp, to);
}
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_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 ((to->to_flags & TOF_TS) != 0) {
uint32_t t, rtt;
t = tcp_tv_to_mssectick(&bbr->rc_tv);
if (TSTMP_GEQ(t, to->to_tsecr)) {
rtt = t - to->to_tsecr;
if (rtt == 0) {
rtt = 1;
}
rtt *= MS_IN_USEC;
tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
apply_filter_min_small(&bbr->r_ctl.rc_rttprop,
rtt, bbr->r_ctl.rc_rcvtime);
}
}
if (bbr_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 (bbr_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 TCB is still
* locked.
*/
static int
bbr_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 ourfinisacked = 0;
int32_t ret_val;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->snd_una) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
ctf_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)) {
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
} else if (thflags & TH_SYN) {
/* non-initial SYN is ignored */
if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
(bbr->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
(bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
ctf_do_drop(m, NULL);
return (0);
}
} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
ctf_do_drop(m, NULL);
return (0);
}
}
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
/*
* In the SYN-RECEIVED state, validate that the packet belongs to
* this connection before trimming the data to fit the receive
* window. Check the sequence number versus IRS since we know the
* sequence numbers haven't wrapped. This is a partial fix for the
* "LAND" DoS attack.
*/
if (SEQ_LT(th->th_seq, tp->irs)) {
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_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;
}
/*
* ok for the first time in lets see if we can use the ts to figure
* out what the initial RTT was.
*/
if ((to->to_flags & TOF_TS) != 0) {
uint32_t t, rtt;
t = tcp_tv_to_mssectick(&bbr->rc_tv);
if (TSTMP_GEQ(t, to->to_tsecr)) {
rtt = t - to->to_tsecr;
if (rtt == 0) {
rtt = 1;
}
rtt *= MS_IN_USEC;
tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, bbr->r_ctl.rc_rcvtime);
}
}
/* Drop off any SYN in the send map (probably not there) */
if (thflags & TH_ACK)
bbr_log_syn(tp, to);
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++;
}
/*
* Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* ->
* 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;
} 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 (bbr_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 (bbr_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 TCB is still
* locked.
*/
static int
bbr_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)
{
struct tcp_bbr *bbr;
int32_t ret_val;
/*
* 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.
*/
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
if (bbr->r_ctl.rc_delivered < (4 * tp->t_maxseg)) {
/*
* If we have delived under 4 segments increase the initial
* window if raised by the peer. We use this to determine
* dynamic and static rwnd's at the end of a connection.
*/
bbr->r_ctl.rc_init_rwnd = max(tiwin, tp->snd_wnd);
}
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)) {
if (tlen == 0) {
if (bbr_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt)) {
return (0);
}
} else {
if (bbr_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt)) {
return (0);
}
}
}
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
/* State changes only happen in bbr_process_data() */
return (bbr_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 TCB is still
* locked.
*/
static int
bbr_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)
{
struct tcp_bbr *bbr;
int32_t ret_val;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static int
bbr_check_data_after_close(struct mbuf *m, struct tcp_bbr *bbr,
struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
{
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
if (bbr->rc_allow_data_af_clo == 0) {
close_now:
tp = tcp_close(tp);
TCPSTAT_INC(tcps_rcvafterclose);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
return (1);
}
if (sbavail(&so->so_snd) == 0)
goto close_now;
/* Ok we allow data that is ignored and a followup reset */
tp->rcv_nxt = th->th_seq + *tlen;
tp->t_flags2 |= TF2_DROP_AF_DATA;
bbr->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 TCB is still
* locked.
*/
static int
bbr_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 ourfinisacked = 0;
int32_t ret_val;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
/*
* We call a new function now so we might continue and setup
* to reset at all data being ack'd.
*/
if (bbr_check_data_after_close(m, bbr, 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_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (bbr_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 (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (bbr_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 TCB is still
* locked.
*/
static int
bbr_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 ourfinisacked = 0;
int32_t ret_val;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
/*
* We call a new function now so we might continue and setup
* to reset at all data being ack'd.
*/
if (bbr_check_data_after_close(m, bbr, 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_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (bbr_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 (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (bbr_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 TCB is still
* locked.
*/
static int
bbr_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 ourfinisacked = 0;
int32_t ret_val;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
/*
* We call a new function now so we might continue and setup
* to reset at all data being ack'd.
*/
if (bbr_check_data_after_close(m, bbr, 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_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* case TCPS_LAST_ACK: Ack processing.
*/
if (bbr_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);
ctf_do_drop(m, tp);
return (1);
}
if (sbavail(&so->so_snd)) {
if (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (bbr_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 TCB is still
* locked.
*/
static int
bbr_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 ourfinisacked = 0;
int32_t ret_val;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
ctf_calc_rwin(so, tp);
/* Reset receive buffer auto scaling when not in bulk receive mode. */
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then we may RST the other end depending on the outcome
* of bbr_check_data_after_close.
*/
if ((so->so_state & SS_NOFDREF) &&
tlen) {
/*
* We call a new function now so we might continue and setup
* to reset at all data being ack'd.
*/
if (bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
return (1);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* 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.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
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_tv_to_mssectick(&bbr->rc_tv);
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 (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
bbr->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (bbr_progress_timeout_check(bbr)) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
INP_WLOCK_ASSERT(tp->t_inpcb);
return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static void
bbr_stop_all_timers(struct tcpcb *tp)
{
struct tcp_bbr *bbr;
/*
* Assure no timers are running.
*/
if (tcp_timer_active(tp, TT_PERSIST)) {
/* We enter in persists, set the flag appropriately */
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
bbr->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
bbr_google_mode_on(struct tcp_bbr *bbr)
{
bbr->rc_use_google = 1;
bbr->rc_no_pacing = 0;
bbr->r_ctl.bbr_google_discount = bbr_google_discount;
bbr->r_use_policer = bbr_policer_detection_enabled;
bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
bbr->bbr_use_rack_cheat = 0;
bbr->r_ctl.rc_incr_tmrs = 0;
bbr->r_ctl.rc_inc_tcp_oh = 0;
bbr->r_ctl.rc_inc_ip_oh = 0;
bbr->r_ctl.rc_inc_enet_oh = 0;
reset_time(&bbr->r_ctl.rc_delrate,
BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
reset_time_small(&bbr->r_ctl.rc_rttprop,
(11 * USECS_IN_SECOND));
tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
}
static void
bbr_google_mode_off(struct tcp_bbr *bbr)
{
bbr->rc_use_google = 0;
bbr->r_ctl.bbr_google_discount = 0;
bbr->no_pacing_until = bbr_no_pacing_until;
bbr->r_use_policer = 0;
if (bbr->no_pacing_until)
bbr->rc_no_pacing = 1;
else
bbr->rc_no_pacing = 0;
if (bbr_use_rack_resend_cheat)
bbr->bbr_use_rack_cheat = 1;
else
bbr->bbr_use_rack_cheat = 0;
if (bbr_incr_timers)
bbr->r_ctl.rc_incr_tmrs = 1;
else
bbr->r_ctl.rc_incr_tmrs = 0;
if (bbr_include_tcp_oh)
bbr->r_ctl.rc_inc_tcp_oh = 1;
else
bbr->r_ctl.rc_inc_tcp_oh = 0;
if (bbr_include_ip_oh)
bbr->r_ctl.rc_inc_ip_oh = 1;
else
bbr->r_ctl.rc_inc_ip_oh = 0;
if (bbr_include_enet_oh)
bbr->r_ctl.rc_inc_enet_oh = 1;
else
bbr->r_ctl.rc_inc_enet_oh = 0;
bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
reset_time(&bbr->r_ctl.rc_delrate,
bbr_num_pktepo_for_del_limit);
reset_time_small(&bbr->r_ctl.rc_rttprop,
(bbr_filter_len_sec * USECS_IN_SECOND));
tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
}
/*
* Return 0 on success, non-zero on failure
* which indicates the error (usually no memory).
*/
static int
bbr_init(struct tcpcb *tp)
{
struct tcp_bbr *bbr = NULL;
struct inpcb *inp;
uint32_t cts;
tp->t_fb_ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
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);
}
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
bbr->rtt_valid = 0;
inp = tp->t_inpcb;
inp->inp_flags2 |= INP_CANNOT_DO_ECN;
inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
TAILQ_INIT(&bbr->r_ctl.rc_map);
TAILQ_INIT(&bbr->r_ctl.rc_free);
TAILQ_INIT(&bbr->r_ctl.rc_tmap);
bbr->rc_tp = tp;
if (tp->t_inpcb) {
bbr->rc_inp = tp->t_inpcb;
}
cts = tcp_get_usecs(&bbr->rc_tv);
tp->t_acktime = 0;
bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
bbr->rc_tlp_threshold = bbr_tlp_thresh;
bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
bbr->r_ctl.rc_min_to = bbr_min_to;
bbr->rc_bbr_state = BBR_STATE_STARTUP;
bbr->r_ctl.bbr_lost_at_state = 0;
bbr->r_ctl.rc_lost_at_startup = 0;
bbr->rc_all_timers_stopped = 0;
bbr->r_ctl.rc_bbr_lastbtlbw = 0;
bbr->r_ctl.rc_pkt_epoch_del = 0;
bbr->r_ctl.rc_pkt_epoch = 0;
bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
bbr->r_ctl.rc_went_idle_time = cts;
bbr->rc_pacer_started = cts;
bbr->r_ctl.rc_pkt_epoch_time = cts;
bbr->r_ctl.rc_rcvtime = cts;
bbr->r_ctl.rc_bbr_state_time = cts;
bbr->r_ctl.rc_del_time = cts;
bbr->r_ctl.rc_tlp_rxt_last_time = cts;
bbr->r_ctl.last_in_probertt = cts;
bbr->skip_gain = 0;
bbr->gain_is_limited = 0;
bbr->no_pacing_until = bbr_no_pacing_until;
if (bbr->no_pacing_until)
bbr->rc_no_pacing = 1;
if (bbr_use_google_algo) {
bbr->rc_no_pacing = 0;
bbr->rc_use_google = 1;
bbr->r_ctl.bbr_google_discount = bbr_google_discount;
bbr->r_use_policer = bbr_policer_detection_enabled;
} else {
bbr->rc_use_google = 0;
bbr->r_ctl.bbr_google_discount = 0;
bbr->r_use_policer = 0;
}
if (bbr_ts_limiting)
bbr->rc_use_ts_limit = 1;
else
bbr->rc_use_ts_limit = 0;
if (bbr_ts_can_raise)
bbr->ts_can_raise = 1;
else
bbr->ts_can_raise = 0;
if (V_tcp_delack_enabled == 1)
tp->t_delayed_ack = 2;
else if (V_tcp_delack_enabled == 0)
tp->t_delayed_ack = 0;
else if (V_tcp_delack_enabled < 100)
tp->t_delayed_ack = V_tcp_delack_enabled;
else
tp->t_delayed_ack = 2;
if (bbr->rc_use_google == 0)
bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
else
bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
bbr->r_ctl.rc_min_rto_ms = bbr_rto_min_ms;
bbr->rc_max_rto_sec = bbr_rto_max_sec;
bbr->rc_init_win = bbr_def_init_win;
if (tp->t_flags & TF_REQ_TSTMP)
bbr->rc_last_options = TCP_TS_OVERHEAD;
bbr->r_ctl.rc_pace_max_segs = tp->t_maxseg - bbr->rc_last_options;
bbr->r_ctl.rc_high_rwnd = tp->snd_wnd;
bbr->r_init_rtt = 1;
counter_u64_add(bbr_flows_nohdwr_pacing, 1);
if (bbr_allow_hdwr_pacing)
bbr->bbr_hdw_pace_ena = 1;
else
bbr->bbr_hdw_pace_ena = 0;
if (bbr_sends_full_iwnd)
bbr->bbr_init_win_cheat = 1;
else
bbr->bbr_init_win_cheat = 0;
bbr->r_ctl.bbr_utter_max = bbr_hptsi_utter_max;
bbr->r_ctl.rc_drain_pg = bbr_drain_gain;
bbr->r_ctl.rc_startup_pg = bbr_high_gain;
bbr->rc_loss_exit = bbr_exit_startup_at_loss;
bbr->r_ctl.bbr_rttprobe_gain_val = bbr_rttprobe_gain;
bbr->r_ctl.bbr_hptsi_per_second = bbr_hptsi_per_second;
bbr->r_ctl.bbr_hptsi_segments_delay_tar = bbr_hptsi_segments_delay_tar;
bbr->r_ctl.bbr_hptsi_segments_max = bbr_hptsi_segments_max;
bbr->r_ctl.bbr_hptsi_segments_floor = bbr_hptsi_segments_floor;
bbr->r_ctl.bbr_hptsi_bytes_min = bbr_hptsi_bytes_min;
bbr->r_ctl.bbr_cross_over = bbr_cross_over;
bbr->r_ctl.rc_rtt_shrinks = cts;
if (bbr->rc_use_google) {
setup_time_filter(&bbr->r_ctl.rc_delrate,
FILTER_TYPE_MAX,
BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
FILTER_TYPE_MIN, (11 * USECS_IN_SECOND));
} else {
setup_time_filter(&bbr->r_ctl.rc_delrate,
FILTER_TYPE_MAX,
bbr_num_pktepo_for_del_limit);
setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
FILTER_TYPE_MIN, (bbr_filter_len_sec * USECS_IN_SECOND));
}
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_INIT, 0);
if (bbr_uses_idle_restart)
bbr->rc_use_idle_restart = 1;
else
bbr->rc_use_idle_restart = 0;
bbr->r_ctl.rc_bbr_cur_del_rate = 0;
bbr->r_ctl.rc_initial_hptsi_bw = bbr_initial_bw_bps;
if (bbr_resends_use_tso)
bbr->rc_resends_use_tso = 1;
#ifdef NETFLIX_PEAKRATE
tp->t_peakrate_thr = tp->t_maxpeakrate;
#endif
if (tp->snd_una != tp->snd_max) {
/* Create a send map for the current outstanding data */
struct bbr_sendmap *rsm;
rsm = bbr_alloc(bbr);
if (rsm == NULL) {
uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
return (ENOMEM);
}
rsm->r_flags = BBR_OVERMAX;
rsm->r_tim_lastsent[0] = cts;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->r_start = tp->snd_una;
rsm->r_end = tp->snd_max;
rsm->r_dupack = 0;
rsm->r_delivered = bbr->r_ctl.rc_delivered;
rsm->r_ts_valid = 0;
rsm->r_del_ack_ts = tp->ts_recent;
rsm->r_del_time = cts;
if (bbr->r_ctl.r_app_limited_until)
rsm->r_app_limited = 1;
else
rsm->r_app_limited = 0;
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
rsm->r_bbr_state = bbr_state_val(bbr);
else
rsm->r_bbr_state = 8;
}
if (bbr_use_rack_resend_cheat && (bbr->rc_use_google == 0))
bbr->bbr_use_rack_cheat = 1;
if (bbr_incr_timers && (bbr->rc_use_google == 0))
bbr->r_ctl.rc_incr_tmrs = 1;
if (bbr_include_tcp_oh && (bbr->rc_use_google == 0))
bbr->r_ctl.rc_inc_tcp_oh = 1;
if (bbr_include_ip_oh && (bbr->rc_use_google == 0))
bbr->r_ctl.rc_inc_ip_oh = 1;
if (bbr_include_enet_oh && (bbr->rc_use_google == 0))
bbr->r_ctl.rc_inc_enet_oh = 1;
bbr_log_type_statechange(bbr, cts, __LINE__);
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->t_srtt)) {
uint32_t rtt;
rtt = (TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
}
/* announce the settings and state */
bbr_log_settings_change(bbr, BBR_RECOVERY_LOWRTT);
tcp_bbr_tso_size_check(bbr, cts);
/*
* Now call the generic function to start a timer. This will place
* the TCB on the hptsi wheel if a timer is needed with appropriate
* flags.
*/
bbr_stop_all_timers(tp);
bbr_start_hpts_timer(bbr, tp, cts, 5, 0, 0);
return (0);
}
/*
* Return 0 if we can accept the connection. Return
* non-zero if we can't handle the connection. A EAGAIN
* means you need to wait until the connection is up.
* a EADDRNOTAVAIL means we can never handle the connection
* (no SACK).
*/
static int
bbr_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) || bbr_sack_not_required) {
return (0);
}
/*
* If we reach here we don't do SACK on this connection so we can
* never do rack.
*/
return (EINVAL);
}
static void
bbr_fini(struct tcpcb *tp, int32_t tcb_is_purged)
{
if (tp->t_fb_ptr) {
uint32_t calc;
struct tcp_bbr *bbr;
struct bbr_sendmap *rsm;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
if (bbr->r_ctl.crte)
tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
bbr_log_flowend(bbr);
bbr->rc_tp = NULL;
if (tp->t_inpcb) {
/* Backout any flags2 we applied */
tp->t_inpcb->inp_flags2 &= ~INP_CANNOT_DO_ECN;
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
}
if (bbr->bbr_hdrw_pacing)
counter_u64_add(bbr_flows_whdwr_pacing, -1);
else
counter_u64_add(bbr_flows_nohdwr_pacing, -1);
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
while (rsm) {
TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
uma_zfree(bbr_zone, rsm);
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
}
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
while (rsm) {
TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
uma_zfree(bbr_zone, rsm);
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
}
calc = bbr->r_ctl.rc_high_rwnd - bbr->r_ctl.rc_init_rwnd;
if (calc > (bbr->r_ctl.rc_init_rwnd / 10))
BBR_STAT_INC(bbr_dynamic_rwnd);
else
BBR_STAT_INC(bbr_static_rwnd);
bbr->r_ctl.rc_free_cnt = 0;
uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
}
/* Make sure snd_nxt is correctly set */
tp->snd_nxt = tp->snd_max;
}
static void
bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win)
{
switch (tp->t_state) {
case TCPS_SYN_SENT:
bbr->r_state = TCPS_SYN_SENT;
bbr->r_substate = bbr_do_syn_sent;
break;
case TCPS_SYN_RECEIVED:
bbr->r_state = TCPS_SYN_RECEIVED;
bbr->r_substate = bbr_do_syn_recv;
break;
case TCPS_ESTABLISHED:
bbr->r_ctl.rc_init_rwnd = max(win, bbr->rc_tp->snd_wnd);
bbr->r_state = TCPS_ESTABLISHED;
bbr->r_substate = bbr_do_established;
break;
case TCPS_CLOSE_WAIT:
bbr->r_state = TCPS_CLOSE_WAIT;
bbr->r_substate = bbr_do_close_wait;
break;
case TCPS_FIN_WAIT_1:
bbr->r_state = TCPS_FIN_WAIT_1;
bbr->r_substate = bbr_do_fin_wait_1;
break;
case TCPS_CLOSING:
bbr->r_state = TCPS_CLOSING;
bbr->r_substate = bbr_do_closing;
break;
case TCPS_LAST_ACK:
bbr->r_state = TCPS_LAST_ACK;
bbr->r_substate = bbr_do_lastack;
break;
case TCPS_FIN_WAIT_2:
bbr->r_state = TCPS_FIN_WAIT_2;
bbr->r_substate = bbr_do_fin_wait_2;
break;
case TCPS_LISTEN:
case TCPS_CLOSED:
case TCPS_TIME_WAIT:
default:
break;
};
}
static void
bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int32_t line, int dolog)
{
/*
* Now what state are we going into now? Is there adjustments
* needed?
*/
int32_t old_state, old_gain;
old_state = bbr_state_val(bbr);
old_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
if (bbr_state_val(bbr) == BBR_SUB_LEVEL1) {
/* Save the lowest srtt we saw in our end of the sub-state */
bbr->rc_hit_state_1 = 0;
if (bbr->r_ctl.bbr_smallest_srtt_this_state != 0xffffffff)
bbr->r_ctl.bbr_smallest_srtt_state2 = bbr->r_ctl.bbr_smallest_srtt_this_state;
}
bbr->rc_bbr_substate++;
if (bbr->rc_bbr_substate >= BBR_SUBSTATE_COUNT) {
/* Cycle back to first state-> gain */
bbr->rc_bbr_substate = 0;
}
if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
/*
* We enter the gain(5/4) cycle (possibly less if
* shallow buffer detection is enabled)
*/
if (bbr->skip_gain) {
/*
* Hardware pacing has set our rate to
* the max and limited our b/w just
* do level i.e. no gain.
*/
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_LEVEL1];
} else if (bbr->gain_is_limited &&
bbr->bbr_hdrw_pacing &&
bbr->r_ctl.crte) {
/*
* We can't gain above the hardware pacing
* rate which is less than our rate + the gain
* calculate the gain needed to reach the hardware
* pacing rate..
*/
uint64_t bw, rate, gain_calc;
bw = bbr_get_bw(bbr);
rate = bbr->r_ctl.crte->rate;
if ((rate > bw) &&
(((bw * (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN]) / (uint64_t)BBR_UNIT) > rate)) {
gain_calc = (rate * BBR_UNIT) / bw;
if (gain_calc < BBR_UNIT)
gain_calc = BBR_UNIT;
bbr->r_ctl.rc_bbr_hptsi_gain = (uint16_t)gain_calc;
} else {
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
}
} else
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
if ((bbr->rc_use_google == 0) && (bbr_gain_to_target == 0)) {
bbr->r_ctl.rc_bbr_state_atflight = cts;
} else
bbr->r_ctl.rc_bbr_state_atflight = 0;
} else if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
bbr->rc_hit_state_1 = 1;
bbr->r_ctl.rc_exta_time_gd = 0;
bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if (bbr_state_drain_2_tar) {
bbr->r_ctl.rc_bbr_state_atflight = 0;
} else
bbr->r_ctl.rc_bbr_state_atflight = cts;
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_DRAIN];
} else {
/* All other cycles hit here 2-7 */
if ((old_state == BBR_SUB_DRAIN) && bbr->rc_hit_state_1) {
if (bbr_sub_drain_slam_cwnd &&
(bbr->rc_use_google == 0) &&
(bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
if ((cts - bbr->r_ctl.rc_bbr_state_time) > bbr_get_rtt(bbr, BBR_RTT_PROP))
bbr->r_ctl.rc_exta_time_gd += ((cts - bbr->r_ctl.rc_bbr_state_time) -
bbr_get_rtt(bbr, BBR_RTT_PROP));
else
bbr->r_ctl.rc_exta_time_gd = 0;
if (bbr->r_ctl.rc_exta_time_gd) {
bbr->r_ctl.rc_level_state_extra = bbr->r_ctl.rc_exta_time_gd;
/* Now chop up the time for each state (div by 7) */
bbr->r_ctl.rc_level_state_extra /= 7;
if (bbr_rand_ot && bbr->r_ctl.rc_level_state_extra) {
/* Add a randomization */
bbr_randomize_extra_state_time(bbr);
}
}
}
bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[bbr_state_val(bbr)];
}
if (bbr->rc_use_google) {
bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
}
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
if (dolog)
bbr_log_type_statechange(bbr, cts, line);
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
uint32_t time_in;
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
counter_u64_add(bbr_state_time[(old_state + 5)], time_in);
} else {
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
}
}
bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
bbr_set_state_target(bbr, __LINE__);
if (bbr_sub_drain_slam_cwnd &&
(bbr->rc_use_google == 0) &&
(bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
/* Slam down the cwnd */
bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
if (bbr_sub_drain_app_limit) {
/* Go app limited if we are on a long drain */
bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered +
ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)));
}
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
if (bbr->rc_lt_use_bw) {
/* In policed mode we clamp pacing_gain to BBR_UNIT */
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
}
/* Google changes TSO size every cycle */
if (bbr->rc_use_google)
tcp_bbr_tso_size_check(bbr, cts);
bbr->r_ctl.gain_epoch = cts;
bbr->r_ctl.rc_bbr_state_time = cts;
bbr->r_ctl.substate_pe = bbr->r_ctl.rc_pkt_epoch;
}
static void
bbr_set_probebw_google_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
{
if ((bbr_state_val(bbr) == BBR_SUB_DRAIN) &&
(google_allow_early_out == 1) &&
(bbr->r_ctl.rc_flight_at_input <= bbr->r_ctl.rc_target_at_state)) {
/* We have reached out target flight size possibly early */
goto change_state;
}
if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time)) {
return;
}
if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_get_rtt(bbr, BBR_RTT_PROP)) {
/*
* Must be a rttProp movement forward before
* we can change states.
*/
return;
}
if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
/*
* The needed time has passed but for
* the gain cycle extra rules apply:
* 1) If we have seen loss, we exit
* 2) If we have not reached the target
* we stay in GAIN (gain-to-target).
*/
if (google_consider_lost && losses)
goto change_state;
if (bbr->r_ctl.rc_target_at_state > bbr->r_ctl.rc_flight_at_input) {
return;
}
}
change_state:
/* For gain we must reach our target, all others last 1 rttProp */
bbr_substate_change(bbr, cts, __LINE__, 1);
}
static void
bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
{
uint32_t flight, bbr_cur_cycle_time;
if (bbr->rc_use_google) {
bbr_set_probebw_google_gains(bbr, cts, losses);
return;
}
if (cts == 0) {
/*
* Never alow cts to be 0 we
* do this so we can judge if
* we have set a timestamp.
*/
cts = 1;
}
if (bbr_state_is_pkt_epoch)
bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
else
bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PROP);
if (bbr->r_ctl.rc_bbr_state_atflight == 0) {
if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
flight = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if (bbr_sub_drain_slam_cwnd && bbr->rc_hit_state_1) {
/* Keep it slam down */
if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state) {
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
if (bbr_sub_drain_app_limit) {
/* Go app limited if we are on a long drain */
bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered + flight);
}
}
if (TSTMP_GT(cts, bbr->r_ctl.gain_epoch) &&
(((cts - bbr->r_ctl.gain_epoch) > bbr_get_rtt(bbr, BBR_RTT_PROP)) ||
(flight >= bbr->r_ctl.flightsize_at_drain))) {
/*
* Still here after the same time as
* the gain. We need to drain harder
* for the next srtt. Reduce by a set amount
* the gain drop is capped at DRAIN states
* value (88).
*/
bbr->r_ctl.flightsize_at_drain = flight;
if (bbr_drain_drop_mul &&
bbr_drain_drop_div &&
(bbr_drain_drop_mul < bbr_drain_drop_div)) {
/* Use your specific drop value (def 4/5 = 20%) */
bbr->r_ctl.rc_bbr_hptsi_gain *= bbr_drain_drop_mul;
bbr->r_ctl.rc_bbr_hptsi_gain /= bbr_drain_drop_div;
} else {
/* You get drop of 20% */
bbr->r_ctl.rc_bbr_hptsi_gain *= 4;
bbr->r_ctl.rc_bbr_hptsi_gain /= 5;
}
if (bbr->r_ctl.rc_bbr_hptsi_gain <= bbr_drain_floor) {
/* Reduce our gain again to the bottom */
bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
}
bbr_log_exit_gain(bbr, cts, 4);
/*
* Extend out so we wait another
* epoch before dropping again.
*/
bbr->r_ctl.gain_epoch = cts;
}
if (flight <= bbr->r_ctl.rc_target_at_state) {
if (bbr_sub_drain_slam_cwnd &&
(bbr->rc_use_google == 0) &&
(bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
bbr_log_exit_gain(bbr, cts, 3);
}
} else {
/* Its a gain */
if (bbr->r_ctl.rc_lost > bbr->r_ctl.bbr_lost_at_state) {
bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
goto change_state;
}
if ((ctf_outstanding(bbr->rc_tp) >= bbr->r_ctl.rc_target_at_state) ||
((ctf_outstanding(bbr->rc_tp) + bbr->rc_tp->t_maxseg - 1) >=
bbr->rc_tp->snd_wnd)) {
bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
bbr_log_exit_gain(bbr, cts, 2);
}
}
/**
* We fall through and return always one of two things has
* occured.
* 1) We are still not at target
* <or>
* 2) We reached the target and set rc_bbr_state_atflight
* which means we no longer hit this block
* next time we are called.
*/
return;
}
change_state:
if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time))
return;
if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_cur_cycle_time) {
/* Less than a full time-period has passed */
return;
}
if (bbr->r_ctl.rc_level_state_extra &&
(bbr_state_val(bbr) > BBR_SUB_DRAIN) &&
((cts - bbr->r_ctl.rc_bbr_state_time) <
(bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
/* Less than a full time-period + extra has passed */
return;
}
if (bbr_gain_gets_extra_too &&
bbr->r_ctl.rc_level_state_extra &&
(bbr_state_val(bbr) == BBR_SUB_GAIN) &&
((cts - bbr->r_ctl.rc_bbr_state_time) <
(bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
/* Less than a full time-period + extra has passed */
return;
}
bbr_substate_change(bbr, cts, __LINE__, 1);
}
static uint32_t
bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain)
{
uint32_t mss, tar;
if (bbr->rc_use_google) {
/* Google just uses the cwnd target */
tar = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), gain);
} else {
mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
bbr->r_ctl.rc_pace_max_segs);
/* Get the base cwnd with gain rounded to a mss */
tar = roundup(bbr_get_raw_target_cwnd(bbr, bbr_get_bw(bbr),
gain), mss);
/* Make sure it is within our min */
if (tar < get_min_cwnd(bbr))
return (get_min_cwnd(bbr));
}
return (tar);
}
static void
bbr_set_state_target(struct tcp_bbr *bbr, int line)
{
uint32_t tar, meth;
if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
/* Special case using old probe-rtt method */
tar = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
meth = 1;
} else {
/* Non-probe-rtt case and reduced probe-rtt */
if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
(bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT)) {
/* For gain cycle we use the hptsi gain */
tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
meth = 2;
} else if ((bbr_target_is_bbunit) || bbr->rc_use_google) {
/*
* If configured, or for google all other states
* get BBR_UNIT.
*/
tar = bbr_get_a_state_target(bbr, BBR_UNIT);
meth = 3;
} else {
/*
* Or we set a target based on the pacing gain
* for non-google mode and default (non-configured).
* Note we don't set a target goal below drain (192).
*/
if (bbr->r_ctl.rc_bbr_hptsi_gain < bbr_hptsi_gain[BBR_SUB_DRAIN]) {
tar = bbr_get_a_state_target(bbr, bbr_hptsi_gain[BBR_SUB_DRAIN]);
meth = 4;
} else {
tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
meth = 5;
}
}
}
bbr_log_set_of_state_target(bbr, tar, line, meth);
bbr->r_ctl.rc_target_at_state = tar;
}
static void
bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
{
/* Change to probe_rtt */
uint32_t time_in;
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.flightsize_at_drain
+ bbr->r_ctl.rc_delivered);
/* Setup so we force feed the filter */
if (bbr->rc_use_google || bbr_probertt_sets_rtt)
bbr->rc_prtt_set_ts = 1;
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
}
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_ENTERPROBE, 0);
bbr->r_ctl.rc_rtt_shrinks = cts;
bbr->r_ctl.last_in_probertt = cts;
bbr->r_ctl.rc_probertt_srttchktim = cts;
bbr->r_ctl.rc_bbr_state_time = cts;
bbr->rc_bbr_state = BBR_STATE_PROBE_RTT;
/* We need to force the filter to update */
if ((bbr_sub_drain_slam_cwnd) &&
bbr->rc_hit_state_1 &&
(bbr->rc_use_google == 0) &&
(bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_saved_cwnd)
bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
} else
bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
/* Update the lost */
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
if ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google){
/* Set to the non-configurable default of 4 (PROBE_RTT_MIN) */
bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
bbr_log_set_of_state_target(bbr, bbr->rc_tp->snd_cwnd, __LINE__, 6);
bbr->r_ctl.rc_target_at_state = bbr->rc_tp->snd_cwnd;
} else {
/*
* We bring it down slowly by using a hptsi gain that is
* probably 75%. This will slowly float down our outstanding
* without tampering with the cwnd.
*/
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
bbr_set_state_target(bbr, __LINE__);
if (bbr_prtt_slam_cwnd &&
(bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
}
if (ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
bbr->r_ctl.rc_target_at_state) {
/* We are at target */
bbr->r_ctl.rc_bbr_enters_probertt = cts;
} else {
/* We need to come down to reach target before our time begins */
bbr->r_ctl.rc_bbr_enters_probertt = 0;
}
bbr->r_ctl.rc_pe_of_prtt = bbr->r_ctl.rc_pkt_epoch;
BBR_STAT_INC(bbr_enter_probertt);
bbr_log_exit_gain(bbr, cts, 0);
bbr_log_type_statechange(bbr, cts, line);
}
static void
bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts)
{
/*
* Sanity check on probe-rtt intervals.
* In crazy situations where we are competing
* against new-reno flows with huge buffers
* our rtt-prop interval could come to dominate
* things if we can't get through a full set
* of cycles, we need to adjust it.
*/
if (bbr_can_adjust_probertt &&
(bbr->rc_use_google == 0)) {
uint16_t val = 0;
uint32_t cur_rttp, fval, newval, baseval;
/* Are we to small and go into probe-rtt to often? */
baseval = (bbr_get_rtt(bbr, BBR_RTT_PROP) * (BBR_SUBSTATE_COUNT + 1));
cur_rttp = roundup(baseval, USECS_IN_SECOND);
fval = bbr_filter_len_sec * USECS_IN_SECOND;
if (bbr_is_ratio == 0) {
if (fval > bbr_rtt_probe_limit)
newval = cur_rttp + (fval - bbr_rtt_probe_limit);
else
newval = cur_rttp;
} else {
int mul;
mul = fval / bbr_rtt_probe_limit;
newval = cur_rttp * mul;
}
if (cur_rttp > bbr->r_ctl.rc_probertt_int) {
bbr->r_ctl.rc_probertt_int = cur_rttp;
reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
val = 1;
} else {
/*
* No adjustments were made
* do we need to shrink it?
*/
if (bbr->r_ctl.rc_probertt_int > bbr_rtt_probe_limit) {
if (cur_rttp <= bbr_rtt_probe_limit) {
/*
* Things have calmed down lets
* shrink all the way to default
*/
bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
reset_time_small(&bbr->r_ctl.rc_rttprop,
(bbr_filter_len_sec * USECS_IN_SECOND));
cur_rttp = bbr_rtt_probe_limit;
newval = (bbr_filter_len_sec * USECS_IN_SECOND);
val = 2;
} else {
/*
* Well does some adjustment make sense?
*/
if (cur_rttp < bbr->r_ctl.rc_probertt_int) {
/* We can reduce interval time some */
bbr->r_ctl.rc_probertt_int = cur_rttp;
reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
val = 3;
}
}
}
}
if (val)
bbr_log_rtt_shrinks(bbr, cts, cur_rttp, newval, __LINE__, BBR_RTTS_RESETS_VALUES, val);
}
}
static void
bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
{
/* Exit probe-rtt */
if (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd) {
tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
bbr_log_exit_gain(bbr, cts, 1);
bbr->rc_hit_state_1 = 0;
bbr->r_ctl.rc_rtt_shrinks = cts;
bbr->r_ctl.last_in_probertt = cts;
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_RTTPROBE, 0);
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
bbr->r_ctl.rc_delivered);
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
uint32_t time_in;
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
}
if (bbr->rc_filled_pipe) {
/* Switch to probe_bw */
bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
bbr_substate_change(bbr, cts, __LINE__, 0);
bbr_log_type_statechange(bbr, cts, __LINE__);
} else {
/* Back to startup */
bbr->rc_bbr_state = BBR_STATE_STARTUP;
bbr->r_ctl.rc_bbr_state_time = cts;
/*
* We don't want to give a complete free 3
* measurements until we exit, so we use
* the number of pe's we were in probe-rtt
* to add to the startup_epoch. That way
* we will still retain the old state.
*/
bbr->r_ctl.rc_bbr_last_startup_epoch += (bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_pe_of_prtt);
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
/* Make sure to use the lower pg when shifting back in */
if (bbr->r_ctl.rc_lost &&
bbr_use_lower_gain_in_startup &&
(bbr->rc_use_google == 0))
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
else
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
/* Probably not needed but set it anyway */
bbr_set_state_target(bbr, __LINE__);
bbr_log_type_statechange(bbr, cts, __LINE__);
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 0);
}
bbr_check_probe_rtt_limits(bbr, cts);
}
static int32_t inline
bbr_should_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts)
{
if ((bbr->rc_past_init_win == 1) &&
(bbr->rc_in_persist == 0) &&
(bbr_calc_time(cts, bbr->r_ctl.rc_rtt_shrinks) >= bbr->r_ctl.rc_probertt_int)) {
return (1);
}
if (bbr_can_force_probertt &&
(bbr->rc_in_persist == 0) &&
(TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
return (1);
}
return (0);
}
static int32_t
bbr_google_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t pkt_epoch)
{
uint64_t btlbw, gain;
if (pkt_epoch == 0) {
/*
* Need to be on a pkt-epoch to continue.
*/
return (0);
}
btlbw = bbr_get_full_bw(bbr);
gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
(uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
if (btlbw >= gain) {
bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
}
if ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)
return (1);
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
return(0);
}
static int32_t inline
bbr_state_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch)
{
/* Have we gained 25% in the last 3 packet based epoch's? */
uint64_t btlbw, gain;
int do_exit;
int delta, rtt_gain;
if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
(bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
/*
* This qualifies as a RTT_PROBE session since we drop the
* data outstanding to nothing and waited more than
* bbr_rtt_probe_time.
*/
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
bbr_set_reduced_rtt(bbr, cts, __LINE__);
}
if (bbr_should_enter_probe_rtt(bbr, cts)) {
bbr_enter_probe_rtt(bbr, cts, __LINE__);
return (0);
}
if (bbr->rc_use_google)
return (bbr_google_startup(bbr, cts, pkt_epoch));
if ((bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
(bbr_use_lower_gain_in_startup)) {
/* Drop to a lower gain 1.5 x since we saw loss */
bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
}
if (pkt_epoch == 0) {
/*
* Need to be on a pkt-epoch to continue.
*/
return (0);
}
if (bbr_rtt_gain_thresh) {
/*
* Do we allow a flow to stay
* in startup with no loss and no
* gain in rtt over a set threshold?
*/
if (bbr->r_ctl.rc_pkt_epoch_rtt &&
bbr->r_ctl.startup_last_srtt &&
(bbr->r_ctl.rc_pkt_epoch_rtt > bbr->r_ctl.startup_last_srtt)) {
delta = bbr->r_ctl.rc_pkt_epoch_rtt - bbr->r_ctl.startup_last_srtt;
rtt_gain = (delta * 100) / bbr->r_ctl.startup_last_srtt;
} else
rtt_gain = 0;
if ((bbr->r_ctl.startup_last_srtt == 0) ||
(bbr->r_ctl.rc_pkt_epoch_rtt < bbr->r_ctl.startup_last_srtt))
/* First time or new lower value */
bbr->r_ctl.startup_last_srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
if ((bbr->r_ctl.rc_lost == 0) &&
(rtt_gain < bbr_rtt_gain_thresh)) {
/*
* No loss, and we are under
* our gain threhold for
* increasing RTT.
*/
if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
bbr->r_ctl.rc_bbr_last_startup_epoch++;
bbr_log_startup_event(bbr, cts, rtt_gain,
delta, bbr->r_ctl.startup_last_srtt, 10);
return (0);
}
}
if ((bbr->r_ctl.r_measurement_count == bbr->r_ctl.last_startup_measure) &&
(bbr->r_ctl.rc_lost_at_startup == bbr->r_ctl.rc_lost) &&
(!IN_RECOVERY(bbr->rc_tp->t_flags))) {
/*
* We only assess if we have a new measurment when
* we have no loss and are not in recovery.
* Drag up by one our last_startup epoch so we will hold
* the number of non-gain we have already accumulated.
*/
if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
bbr->r_ctl.rc_bbr_last_startup_epoch++;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 9);
return (0);
}
/* Case where we reduced the lost (bad retransmit) */
if (bbr->r_ctl.rc_lost_at_startup > bbr->r_ctl.rc_lost)
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
bbr->r_ctl.last_startup_measure = bbr->r_ctl.r_measurement_count;
btlbw = bbr_get_full_bw(bbr);
if (bbr->r_ctl.rc_bbr_hptsi_gain == bbr_startup_lower)
gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
(uint64_t)bbr_low_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
else
gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
(uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
do_exit = 0;
if (btlbw > bbr->r_ctl.rc_bbr_lastbtlbw)
bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
if (btlbw >= gain) {
bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
/* Update the lost so we won't exit in next set of tests */
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
}
if ((bbr->rc_loss_exit &&
(bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
(bbr->r_ctl.rc_pkt_epoch_loss_rate > bbr_startup_loss_thresh)) &&
((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)) {
/*
* If we had no gain, we had loss and that loss was above
* our threshould, the rwnd is not constrained, and we have
* had at least 3 packet epochs exit. Note that this is
* switched off by sysctl. Google does not do this by the
* way.
*/
if ((ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
(2 * max(bbr->r_ctl.rc_pace_max_segs, bbr->rc_tp->t_maxseg))) <= bbr->rc_tp->snd_wnd) {
do_exit = 1;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 4);
} else {
/* Just record an updated loss value */
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 5);
}
} else
bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
if (((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS) ||
do_exit) {
/* Return 1 to exit the startup state. */
return (1);
}
/* Stay in startup */
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
return (0);
}
static void
bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch, uint32_t losses)
{
/*
* A tick occured in the rtt epoch do we need to do anything?
*/
#ifdef BBR_INVARIANTS
if ((bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
(bbr->rc_bbr_state != BBR_STATE_DRAIN) &&
(bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) &&
(bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
(bbr->rc_bbr_state != BBR_STATE_PROBE_BW)) {
/* Debug code? */
panic("Unknown BBR state %d?\n", bbr->rc_bbr_state);
}
#endif
if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
/* Do we exit the startup state? */
if (bbr_state_startup(bbr, cts, epoch, pkt_epoch)) {
uint32_t time_in;
bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 6);
bbr->rc_filled_pipe = 1;
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
} else
time_in = 0;
if (bbr->rc_no_pacing)
bbr->rc_no_pacing = 0;
bbr->r_ctl.rc_bbr_state_time = cts;
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_drain_pg;
bbr->rc_bbr_state = BBR_STATE_DRAIN;
bbr_set_state_target(bbr, __LINE__);
if ((bbr->rc_use_google == 0) &&
bbr_slam_cwnd_in_main_drain) {
/* Here we don't have to worry about probe-rtt */
bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
bbr_log_type_statechange(bbr, cts, __LINE__);
if (ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
bbr->r_ctl.rc_target_at_state) {
/*
* Switch to probe_bw if we are already
* there
*/
bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
bbr_substate_change(bbr, cts, __LINE__, 0);
bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
bbr_log_type_statechange(bbr, cts, __LINE__);
}
}
} else if (bbr->rc_bbr_state == BBR_STATE_IDLE_EXIT) {
uint32_t inflight;
struct tcpcb *tp;
tp = bbr->rc_tp;
inflight = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if (inflight >= bbr->r_ctl.rc_target_at_state) {
/* We have reached a flight of the cwnd target */
bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
bbr_set_state_target(bbr, __LINE__);
/*
* Rig it so we don't do anything crazy and
* start fresh with a new randomization.
*/
bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
bbr->rc_bbr_substate = BBR_SUB_LEVEL6;
bbr_substate_change(bbr, cts, __LINE__, 1);
}
} else if (bbr->rc_bbr_state == BBR_STATE_DRAIN) {
/* Has in-flight reached the bdp (or less)? */
uint32_t inflight;
struct tcpcb *tp;
tp = bbr->rc_tp;
inflight = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if ((bbr->rc_use_google == 0) &&
bbr_slam_cwnd_in_main_drain &&
(bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
/*
* Here we don't have to worry about probe-rtt
* re-slam it, but keep it slammed down.
*/
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
if (inflight <= bbr->r_ctl.rc_target_at_state) {
/* We have drained */
bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
uint32_t time_in;
time_in = cts - bbr->r_ctl.rc_bbr_state_time;
counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
}
if ((bbr->rc_use_google == 0) &&
bbr_slam_cwnd_in_main_drain &&
(tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
/* Restore the cwnd */
tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
/* Setup probe-rtt has being done now RRS-HERE */
bbr->r_ctl.rc_rtt_shrinks = cts;
bbr->r_ctl.last_in_probertt = cts;
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_LEAVE_DRAIN, 0);
/* Randomly pick a sub-state */
bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
bbr_substate_change(bbr, cts, __LINE__, 0);
bbr_log_type_statechange(bbr, cts, __LINE__);
}
} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) {
uint32_t flight;
flight = ctf_flight_size(bbr->rc_tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
bbr->r_ctl.r_app_limited_until = (flight + bbr->r_ctl.rc_delivered);
if (((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google) &&
(bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
/*
* We must keep cwnd at the desired MSS.
*/
bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
} else if ((bbr_prtt_slam_cwnd) &&
(bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
/* Re-slam it */
bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
}
if (bbr->r_ctl.rc_bbr_enters_probertt == 0) {
/* Has outstanding reached our target? */
if (flight <= bbr->r_ctl.rc_target_at_state) {
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_REACHTAR, 0);
bbr->r_ctl.rc_bbr_enters_probertt = cts;
/* If time is exactly 0, be 1usec off */
if (bbr->r_ctl.rc_bbr_enters_probertt == 0)
bbr->r_ctl.rc_bbr_enters_probertt = 1;
if (bbr->rc_use_google == 0) {
/*
* Restore any lowering that as occured to
* reach here
*/
if (bbr->r_ctl.bbr_rttprobe_gain_val)
bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
else
bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
}
}
if ((bbr->r_ctl.rc_bbr_enters_probertt == 0) &&
(bbr->rc_use_google == 0) &&
bbr->r_ctl.bbr_rttprobe_gain_val &&
(((cts - bbr->r_ctl.rc_probertt_srttchktim) > bbr_get_rtt(bbr, bbr_drain_rtt)) ||
(flight >= bbr->r_ctl.flightsize_at_drain))) {
/*
* We have doddled with our current hptsi
* gain an srtt and have still not made it
* to target, or we have increased our flight.
* Lets reduce the gain by xx%
* flooring the reduce at DRAIN (based on
* mul/div)
*/
int red;
bbr->r_ctl.flightsize_at_drain = flight;
bbr->r_ctl.rc_probertt_srttchktim = cts;
red = max((bbr->r_ctl.bbr_rttprobe_gain_val / 10), 1);
if ((bbr->r_ctl.rc_bbr_hptsi_gain - red) > max(bbr_drain_floor, 1)) {
/* Reduce our gain again */
bbr->r_ctl.rc_bbr_hptsi_gain -= red;
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG, 0);
} else if (bbr->r_ctl.rc_bbr_hptsi_gain > max(bbr_drain_floor, 1)) {
/* one more chance before we give up */
bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG_FINAL, 0);
} else {
/* At the very bottom */
bbr->r_ctl.rc_bbr_hptsi_gain = max((bbr_drain_floor-1), 1);
}
}
}
if (bbr->r_ctl.rc_bbr_enters_probertt &&
(TSTMP_GT(cts, bbr->r_ctl.rc_bbr_enters_probertt)) &&
((cts - bbr->r_ctl.rc_bbr_enters_probertt) >= bbr_rtt_probe_time)) {
/* Time to exit probe RTT normally */
bbr_exit_probe_rtt(bbr->rc_tp, bbr, cts);
}
} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
(bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
/*
* This qualifies as a RTT_PROBE session since we
* drop the data outstanding to nothing and waited
* more than bbr_rtt_probe_time.
*/
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
bbr_set_reduced_rtt(bbr, cts, __LINE__);
}
if (bbr_should_enter_probe_rtt(bbr, cts)) {
bbr_enter_probe_rtt(bbr, cts, __LINE__);
} else {
bbr_set_probebw_gains(bbr, cts, losses);
}
}
}
static void
bbr_check_bbr_for_state(struct tcp_bbr *bbr, uint32_t cts, int32_t line, uint32_t losses)
{
int32_t epoch = 0;
if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
bbr_set_epoch(bbr, cts, line);
/* At each epoch doe lt bw sampling */
epoch = 1;
}
bbr_state_change(bbr, cts, epoch, bbr->rc_is_pkt_epoch_now, losses);
}
static int
bbr_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
int32_t nxt_pkt, struct timeval *tv)
{
int32_t thflags, retval;
uint32_t cts, lcts;
uint32_t tiwin;
struct tcpopt to;
struct tcp_bbr *bbr;
struct bbr_sendmap *rsm;
struct timeval ltv;
int32_t did_out = 0;
int32_t in_recovery;
uint16_t nsegs;
int32_t prev_state;
uint32_t lost;
nsegs = max(1, m->m_pkthdr.lro_nsegs);
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
/* add in our stats */
kern_prefetch(bbr, &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 write lock on tcbinfo. Otherwise, we
* allow the tcbinfo to be in either alocked or unlocked, as the
* caller may have unnecessarily acquired a write lock due to a
* race.
*/
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__));
tp->t_rcvtime = ticks;
/*
* Unscale the window into a 32-bit value. For the SYN_SENT state
* the scale is zero.
*/
tiwin = th->th_win << tp->snd_scale;
#ifdef NETFLIX_STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
#endif
/*
* 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 (m->m_flags & M_TSTMP) {
/* Prefer the hardware timestamp if present */
struct timespec ts;
mbuf_tstmp2timespec(m, &ts);
bbr->rc_tv.tv_sec = ts.tv_sec;
bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
} else if (m->m_flags & M_TSTMP_LRO) {
/* Next the arrival timestamp */
struct timespec ts;
mbuf_tstmp2timespec(m, &ts);
bbr->rc_tv.tv_sec = ts.tv_sec;
bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
} else {
/*
* Ok just get the current time.
*/
bbr->r_ctl.rc_rcvtime = lcts = cts = tcp_get_usecs(&bbr->rc_tv);
}
/*
* 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, tcp_tv_to_mssectick(&bbr->rc_tv)))
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 (bbr->r_state == 0) {
/*
* Process options only when we get SYN/ACK back. The SYN
* case for incoming connections is handled in tcp_syncache.
* According to RFC1323 the window field in a SYN (i.e., a
* <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
* this is traditional behavior, may need to be cleaned up.
*/
if (bbr->rc_inp == NULL) {
bbr->rc_inp = tp->t_inpcb;
}
/*
* We need to init rc_inp here since its not init'd when
* bbr_init is called
*/
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 = tcp_tv_to_mssectick(&bbr->rc_tv);
}
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) {
/* Bail */
tcp_switch_back_to_default(tp);
(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
tlen, iptos);
return (1);
}
/* Set the flag */
bbr->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
tcp_set_hpts(tp->t_inpcb);
sack_filter_clear(&bbr->r_ctl.bbr_sf, th->th_ack);
}
if (thflags & TH_ACK) {
/* Track ack types */
if (to.to_flags & TOF_SACK)
BBR_STAT_INC(bbr_acks_with_sacks);
else
BBR_STAT_INC(bbr_plain_acks);
}
/*
* 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 (bbr->r_state != tp->t_state)
bbr_set_state(tp, bbr, tiwin);
if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map)) != NULL)
kern_prefetch(rsm, &prev_state);
prev_state = bbr->r_state;
bbr->rc_ack_was_delayed = 0;
lost = bbr->r_ctl.rc_lost;
bbr->rc_is_pkt_epoch_now = 0;
if (m->m_flags & (M_TSTMP|M_TSTMP_LRO)) {
/* Get the real time into lcts and figure the real delay */
lcts = tcp_get_usecs(&ltv);
if (TSTMP_GT(lcts, cts)) {
bbr->r_ctl.rc_ack_hdwr_delay = lcts - cts;
bbr->rc_ack_was_delayed = 1;
if (TSTMP_GT(bbr->r_ctl.rc_ack_hdwr_delay,
bbr->r_ctl.highest_hdwr_delay))
bbr->r_ctl.highest_hdwr_delay = bbr->r_ctl.rc_ack_hdwr_delay;
} else {
bbr->r_ctl.rc_ack_hdwr_delay = 0;
bbr->rc_ack_was_delayed = 0;
}
} else {
bbr->r_ctl.rc_ack_hdwr_delay = 0;
bbr->rc_ack_was_delayed = 0;
}
bbr_log_ack_event(bbr, th, &to, tlen, nsegs, cts, nxt_pkt, m);
if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
retval = 0;
m_freem(m);
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))) {
ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
in_recovery = IN_RECOVERY(tp->t_flags);
if (tiwin > bbr->r_ctl.rc_high_rwnd)
bbr->r_ctl.rc_high_rwnd = tiwin;
#ifdef BBR_INVARIANTS
if ((tp->t_inpcb->inp_flags & INP_DROPPED) ||
(tp->t_inpcb->inp_flags2 & INP_FREED)) {
panic("tp:%p bbr:%p given a dropped inp:%p",
tp, bbr, tp->t_inpcb);
}
#endif
bbr->r_ctl.rc_flight_at_input = ctf_flight_size(tp,
(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
bbr->rtt_valid = 0;
if (to.to_flags & TOF_TS) {
bbr->rc_ts_valid = 1;
bbr->r_ctl.last_inbound_ts = to.to_tsval;
} else {
bbr->rc_ts_valid = 0;
bbr->r_ctl.last_inbound_ts = 0;
}
retval = (*bbr->r_substate) (m, th, so,
tp, &to, drop_hdrlen,
tlen, tiwin, thflags, nxt_pkt);
#ifdef BBR_INVARIANTS
if ((retval == 0) &&
(tp->t_inpcb == NULL)) {
panic("retval:%d tp:%p t_inpcb:NULL state:%d",
retval, tp, prev_state);
}
#endif
if (nxt_pkt == 0)
BBR_STAT_INC(bbr_rlock_left_ret0);
else
BBR_STAT_INC(bbr_rlock_left_ret1);
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_bbr_xmit_timer_commit(bbr, tp, cts);
if (bbr->rc_is_pkt_epoch_now)
bbr_set_pktepoch(bbr, cts, __LINE__);
bbr_check_bbr_for_state(bbr, cts, __LINE__, (bbr->r_ctl.rc_lost - lost));
if (nxt_pkt == 0) {
if (bbr->r_wanted_output != 0) {
bbr->rc_output_starts_timer = 0;
did_out = 1;
(void)tp->t_fb->tfb_tcp_output(tp);
} else
bbr_start_hpts_timer(bbr, tp, cts, 6, 0, 0);
}
if ((nxt_pkt == 0) &&
((bbr->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 || bbr->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)?
*/
if ((tp->snd_max == tp->snd_una) &&
((tp->t_flags & TF_DELACK) == 0) &&
(bbr->rc_inp->inp_in_hpts) &&
(bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/*
* keep alive not needed if we are hptsi
* output yet
*/
;
} else {
if (bbr->rc_inp->inp_in_hpts) {
tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
(TSTMP_GT(lcts, bbr->rc_pacer_started))) {
uint32_t del;
del = lcts - bbr->rc_pacer_started;
if (del > bbr->r_ctl.rc_last_delay_val) {
BBR_STAT_INC(bbr_force_timer_start);
bbr->r_ctl.rc_last_delay_val -= del;
bbr->rc_pacer_started = lcts;
} else {
/* We are late */
BBR_STAT_INC(bbr_force_output);
(void)tp->t_fb->tfb_tcp_output(tp);
}
}
}
bbr_start_hpts_timer(bbr, tp, cts, 8, bbr->r_ctl.rc_last_delay_val,
0);
}
} else if ((bbr->rc_output_starts_timer == 0) && (nxt_pkt == 0)) {
/* Do we have the correct timer running? */
bbr_timer_audit(tp, bbr, lcts, &so->so_snd);
}
/* Do we have a new state */
if (bbr->r_state != tp->t_state)
bbr_set_state(tp, bbr, tiwin);
done_with_input:
bbr_log_doseg_done(bbr, cts, nxt_pkt, did_out);
if (did_out)
bbr->r_wanted_output = 0;
#ifdef BBR_INVARIANTS
if (tp->t_inpcb == NULL) {
panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
did_out,
retval, tp, prev_state);
}
#endif
}
return (retval);
}
static void
bbr_log_type_hrdwtso(struct tcpcb *tp, struct tcp_bbr *bbr, int len, int mod, int what_we_can_send)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
uint32_t cts;
cts = tcp_get_usecs(&tv);
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
log.u_bbr.flex1 = bbr->r_ctl.rc_pace_min_segs;
log.u_bbr.flex2 = what_we_can_send;
log.u_bbr.flex3 = bbr->r_ctl.rc_pace_max_segs;
log.u_bbr.flex4 = len;
log.u_bbr.flex5 = 0;
log.u_bbr.flex7 = mod;
log.u_bbr.flex8 = 1;
TCP_LOG_EVENTP(tp, NULL,
&tp->t_inpcb->inp_socket->so_rcv,
&tp->t_inpcb->inp_socket->so_snd,
TCP_HDWR_TLS, 0,
0, &log, false, &tv);
}
}
static void
bbr_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;
int retval;
/* First lets see if we have old packets */
if (tp->t_in_pkt) {
if (ctf_do_queued_segments(so, tp, 1)) {
m_freem(m);
return;
}
}
if (m->m_flags & M_TSTMP_LRO) {
tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
} else {
/* Should not be should we kassert instead? */
tcp_get_usecs(&tv);
}
retval = bbr_do_segment_nounlock(m, th, so, tp,
drop_hdrlen, tlen, iptos, 0, &tv);
if (retval == 0)
INP_WUNLOCK(tp->t_inpcb);
}
/*
* Return how much data can be sent without violating the
* cwnd or rwnd.
*/
static inline uint32_t
bbr_what_can_we_send(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t sendwin,
uint32_t avail, int32_t sb_offset, uint32_t cts)
{
uint32_t len;
if (ctf_outstanding(tp) >= tp->snd_wnd) {
/* We never want to go over our peers rcv-window */
len = 0;
} else {
uint32_t flight;
flight = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
if (flight >= sendwin) {
/*
* We have in flight what we are allowed by cwnd (if
* it was rwnd blocking it would have hit above out
* >= tp->snd_wnd).
*/
return (0);
}
len = sendwin - flight;
if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
/* We would send too much (beyond the rwnd) */
len = tp->snd_wnd - ctf_outstanding(tp);
}
if ((len + sb_offset) > avail) {
/*
* We don't have that much in the SB, how much is
* there?
*/
len = avail - sb_offset;
}
}
return (len);
}
static inline void
bbr_do_error_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
{
#ifdef NETFLIX_STATS
TCPSTAT_INC(tcps_sndpack_error);
TCPSTAT_ADD(tcps_sndbyte_error, len);
#endif
}
static inline void
bbr_do_send_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
{
if (error) {
bbr_do_error_accounting(tp, bbr, rsm, len, error);
return;
}
if ((tp->t_flags & TF_FORCEDATA) && len == 1) {
/* Window probe */
TCPSTAT_INC(tcps_sndprobe);
#ifdef NETFLIX_STATS
stats_voi_update_abs_u32(tp->t_stats,
VOI_TCP_RETXPB, len);
#endif
} else if (rsm) {
if (rsm->r_flags & BBR_TLP) {
/*
* TLP should not count in retran count, but in its
* own bin
*/
#ifdef NETFLIX_STATS
tp->t_sndtlppack++;
tp->t_sndtlpbyte += len;
TCPSTAT_INC(tcps_tlpresends);
TCPSTAT_ADD(tcps_tlpresend_bytes, len);
#endif
} else {
/* Retransmit */
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
}
/*
* Logs in 0 - 8, 8 is all non probe_bw states 0-7 is
* sub-state
*/
counter_u64_add(bbr_state_lost[rsm->r_bbr_state], len);
if (bbr->rc_bbr_state != BBR_STATE_PROBE_BW) {
/* Non probe_bw log in 1, 2, or 4. */
counter_u64_add(bbr_state_resend[bbr->rc_bbr_state], len);
} else {
/*
* Log our probe state 3, and log also 5-13 to show
* us the recovery sub-state for the send. This
* means that 3 == (5+6+7+8+9+10+11+12+13)
*/
counter_u64_add(bbr_state_resend[BBR_STATE_PROBE_BW], len);
counter_u64_add(bbr_state_resend[(bbr_state_val(bbr) + 5)], len);
}
/* Place in both 16's the totals of retransmitted */
counter_u64_add(bbr_state_lost[16], len);
counter_u64_add(bbr_state_resend[16], len);
/* Place in 17's the total sent */
counter_u64_add(bbr_state_resend[17], len);
counter_u64_add(bbr_state_lost[17], len);
} else {
/* New sends */
TCPSTAT_INC(tcps_sndpack);
TCPSTAT_ADD(tcps_sndbyte, len);
/* Place in 17's the total sent */
counter_u64_add(bbr_state_resend[17], len);
counter_u64_add(bbr_state_lost[17], len);
#ifdef NETFLIX_STATS
stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
len);
#endif
}
}
static void
bbr_cwnd_limiting(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t in_level)
{
if (bbr->rc_filled_pipe && bbr_target_cwnd_mult_limit && (bbr->rc_use_google == 0)) {
/*
* Limit the cwnd to not be above N x the target plus whats
* is outstanding. The target is based on the current b/w
* estimate.
*/
uint32_t target;
target = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), BBR_UNIT);
target += ctf_outstanding(tp);
target *= bbr_target_cwnd_mult_limit;
if (tp->snd_cwnd > target)
tp->snd_cwnd = target;
bbr_log_type_cwndupd(bbr, 0, 0, 0, 10, 0, 0, __LINE__);
}
}
static int
bbr_window_update_needed(struct tcpcb *tp, struct socket *so, uint32_t recwin, int32_t maxseg)
{
/*
* "adv" is the amount we could increase the window, taking into
* account that we are limited by TCP_MAXWIN << tp->rcv_scale.
*/
uint32_t adv;
int32_t oldwin;
adv = min(recwin, 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)
return (0);
if (adv >= (2 * maxseg) &&
(adv >= (so->so_rcv.sb_hiwat / 4) ||
recwin <= (so->so_rcv.sb_hiwat / 8) ||
so->so_rcv.sb_hiwat <= 8 * maxseg)) {
return (1);
}
if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
return (1);
return (0);
}
/*
* Return 0 on success and a errno on failure to send.
* Note that a 0 return may not mean we sent anything
* if the TCB was on the hpts. A non-zero return
* does indicate the error we got from ip[6]_output.
*/
static int
bbr_output_wtime(struct tcpcb *tp, const struct timeval *tv)
{
struct socket *so;
int32_t len;
uint32_t cts;
uint32_t recwin, sendwin;
int32_t sb_offset;
int32_t flags, abandon, error = 0;
struct tcp_log_buffer *lgb = NULL;
struct mbuf *m;
struct mbuf *mb;
uint32_t if_hw_tsomaxsegcount = 0;
uint32_t if_hw_tsomaxsegsize = 0;
uint32_t if_hw_tsomax = 0;
struct ip *ip = NULL;
#ifdef TCPDEBUG
struct ipovly *ipov = NULL;
#endif
struct tcp_bbr *bbr;
struct tcphdr *th;
#ifdef NETFLIX_TCPOUDP
struct udphdr *udp = NULL;
#endif
u_char opt[TCP_MAXOLEN];
unsigned ipoptlen, optlen, hdrlen;
#ifdef NETFLIX_TCPOUDP
unsigned ulen;
#endif
uint32_t bbr_seq;
uint32_t delay_calc=0;
uint8_t doing_tlp = 0;
uint8_t local_options;
#ifdef BBR_INVARIANTS
uint8_t doing_retran_from = 0;
uint8_t picked_up_retran = 0;
#endif
uint8_t wanted_cookie = 0;
uint8_t more_to_rxt=0;
int32_t prefetch_so_done = 0;
int32_t prefetch_rsm = 0;
uint32_t what_we_can = 0;
uint32_t tot_len = 0;
uint32_t rtr_cnt = 0;
uint32_t maxseg, pace_max_segs, p_maxseg;
int32_t csum_flags;
int32_t hw_tls;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
unsigned ipsec_optlen = 0;
#endif
volatile int32_t sack_rxmit;
struct bbr_sendmap *rsm = NULL;
int32_t tso, mtu;
int force_tso = 0;
struct tcpopt to;
int32_t slot = 0;
struct inpcb *inp;
struct sockbuf *sb;
uint32_t hpts_calling;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
int32_t isipv6;
#endif
uint8_t app_limited = BBR_JR_SENT_DATA;
uint8_t filled_all = 0;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
/* We take a cache hit here */
memcpy(&bbr->rc_tv, tv, sizeof(struct timeval));
cts = tcp_tv_to_usectick(&bbr->rc_tv);
inp = bbr->rc_inp;
so = inp->inp_socket;
sb = &so->so_snd;
#ifdef KERN_TLS
if (sb->sb_flags & SB_TLS_IFNET)
hw_tls = 1;
else
#endif
hw_tls = 0;
kern_prefetch(sb, &maxseg);
maxseg = tp->t_maxseg - bbr->rc_last_options;
if (bbr_minseg(bbr) < maxseg) {
tcp_bbr_tso_size_check(bbr, cts);
}
/* Remove any flags that indicate we are pacing on the inp */
pace_max_segs = bbr->r_ctl.rc_pace_max_segs;
p_maxseg = min(maxseg, pace_max_segs);
INP_WLOCK_ASSERT(inp);
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
return (tcp_offload_output(tp));
#endif
#ifdef INET6
if (bbr->r_state) {
/* Use the cache line loaded if possible */
isipv6 = bbr->r_is_v6;
} else {
isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
}
#endif
if (((bbr->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.
* Possibly remove from the hpts so we can send/recv etc.
*/
if ((tp->t_flags & TF_ACKNOW) == 0) {
/*
* No immediate demand right now to send an ack, but
* the user may have read, making room for new data
* (a window update). If so we may want to cancel
* whatever timer is running (KEEP/DEL-ACK?) and
* continue to send out a window update. Or we may
* have gotten more data into the socket buffer to
* send.
*/
recwin = min(max(sbspace(&so->so_rcv), 0),
TCP_MAXWIN << tp->rcv_scale);
if ((bbr_window_update_needed(tp, so, recwin, maxseg) == 0) &&
((sbavail(sb) + ((tcp_outflags[tp->t_state] & TH_FIN) ? 1 : 0)) <=
(tp->snd_max - tp->snd_una))) {
/*
* Nothing new to send and no window update
* is needed to send. Lets just return and
* let the timer-run off.
*/
return (0);
}
}
tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
bbr_timer_cancel(bbr, __LINE__, cts);
}
if (bbr->r_ctl.rc_last_delay_val) {
/* Calculate a rough delay for early escape to sending */
if (SEQ_GT(cts, bbr->rc_pacer_started))
delay_calc = cts - bbr->rc_pacer_started;
if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
delay_calc -= bbr->r_ctl.rc_last_delay_val;
else
delay_calc = 0;
}
/* Mark that we have called bbr_output(). */
if ((bbr->r_timer_override) ||
(tp->t_flags & TF_FORCEDATA) ||
(tp->t_state < TCPS_ESTABLISHED)) {
/* Timeouts or early states are exempt */
if (inp->inp_in_hpts)
tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
} else if (inp->inp_in_hpts) {
if ((bbr->r_ctl.rc_last_delay_val) &&
(bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
delay_calc) {
/*
* We were being paced for output and the delay has
* already exceeded when we were supposed to be
* called, lets go ahead and pull out of the hpts
* and call output.
*/
counter_u64_add(bbr_out_size[TCP_MSS_ACCT_LATE], 1);
bbr->r_ctl.rc_last_delay_val = 0;
tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
} else if (tp->t_state == TCPS_CLOSED) {
bbr->r_ctl.rc_last_delay_val = 0;
tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
} else {
/*
* On the hpts, you shall not pass! even if ACKNOW
* is on, we will when the hpts fires, unless of
* course we are overdue.
*/
counter_u64_add(bbr_out_size[TCP_MSS_ACCT_INPACE], 1);
return (0);
}
}
bbr->rc_cwnd_limited = 0;
if (bbr->r_ctl.rc_last_delay_val) {
/* recalculate the real delay and deal with over/under */
if (SEQ_GT(cts, bbr->rc_pacer_started))
delay_calc = cts - bbr->rc_pacer_started;
else
delay_calc = 0;
if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
/* Setup the delay which will be added in */
delay_calc -= bbr->r_ctl.rc_last_delay_val;
else {
/*
* We are early setup to adjust
* our slot time.
*/
bbr->r_ctl.rc_agg_early += (bbr->r_ctl.rc_last_delay_val - delay_calc);
bbr->r_ctl.rc_last_delay_val = 0;
bbr->r_agg_early_set = 1;
if (bbr->r_ctl.rc_hptsi_agg_delay) {
if (bbr->r_ctl.rc_hptsi_agg_delay >= bbr->r_ctl.rc_agg_early) {
/* Nope our previous late cancels out the early */
bbr->r_ctl.rc_hptsi_agg_delay -= bbr->r_ctl.rc_agg_early;
bbr->r_agg_early_set = 0;
bbr->r_ctl.rc_agg_early = 0;
} else {
bbr->r_ctl.rc_agg_early -= bbr->r_ctl.rc_hptsi_agg_delay;
bbr->r_ctl.rc_hptsi_agg_delay = 0;
}
}
bbr_log_pacing_delay_calc(bbr, inp->inp_hpts_calls,
bbr->r_ctl.rc_agg_early, cts, 3, 0,
bbr->r_agg_early_set, 3);
BBR_STAT_INC(bbr_early);
delay_calc = 0;
}
} else {
/* We were not delayed due to hptsi */
if (bbr->r_agg_early_set)
bbr->r_ctl.rc_agg_early = 0;
bbr->r_agg_early_set = 0;
delay_calc = 0;
}
if (delay_calc) {
/*
* We had a hptsi delay which means we are falling behind on
* sending at the expected rate. Calculate an extra amount
* of data we can send, if any, to put us back on track.
*/
if ((bbr->r_ctl.rc_hptsi_agg_delay + delay_calc) < bbr->r_ctl.rc_hptsi_agg_delay)
bbr->r_ctl.rc_hptsi_agg_delay = 0xffffffff;
else
bbr->r_ctl.rc_hptsi_agg_delay += delay_calc;
}
sendwin = min(tp->snd_wnd, tp->snd_cwnd);
if ((tp->snd_una == tp->snd_max) &&
(bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
(sbavail(sb))) {
/*
* Ok we have been idle with nothing outstanding
* we possibly need to start fresh with either a new
* suite of states or a fast-ramp up.
*/
bbr_restart_after_idle(bbr,
cts, bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time));
}
/*
* Now was there a hptsi delay where we are behind? We only count
* being behind if: a) We are not in recovery. b) There was a delay.
* <and> c) We had room to send something.
*
*/
hpts_calling = inp->inp_hpts_calls;
inp->inp_hpts_calls = 0;
if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
if (bbr_process_timers(tp, bbr, cts, hpts_calling)) {
counter_u64_add(bbr_out_size[TCP_MSS_ACCT_ATIMER], 1);
return (0);
}
}
bbr->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
if (hpts_calling &&
(bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
bbr->r_ctl.rc_last_delay_val = 0;
}
bbr->r_timer_override = 0;
bbr->r_wanted_output = 0;
/*
* For TFO connections in SYN_RECEIVED, only allow the initial
* SYN|ACK and those sent by the retransmit timer.
*/
if (IS_FASTOPEN(tp->t_flags) &&
((tp->t_state == TCPS_SYN_RECEIVED) ||
(tp->t_state == TCPS_SYN_SENT)) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* inital SYN or SYN|ACK sent */
(tp->t_rxtshift == 0)) { /* not a retransmit */
return (0);
}
/*
* Before sending anything check for a state update. For hpts
* calling without input this is important. If its input calling
* then this was already done.
*/
if (bbr->rc_use_google == 0)
bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
again:
/*
* If we've recently taken a timeout, snd_max will be greater than
* snd_max. BBR in general does not pay much attention to snd_nxt
* for historic reasons the persist timer still uses it. This means
* we have to look at it. All retransmissions that are not persits
* use the rsm that needs to be sent so snd_nxt is ignored. At the
* end of this routine we pull snd_nxt always up to snd_max.
*/
doing_tlp = 0;
#ifdef BBR_INVARIANTS
doing_retran_from = picked_up_retran = 0;
#endif
error = 0;
tso = 0;
slot = 0;
mtu = 0;
sendwin = min(tp->snd_wnd, tp->snd_cwnd);
sb_offset = tp->snd_max - tp->snd_una;
flags = tcp_outflags[tp->t_state];
sack_rxmit = 0;
len = 0;
rsm = NULL;
if (flags & TH_RST) {
SOCKBUF_LOCK(sb);
goto send;
}
recheck_resend:
while (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
/* We need to always have one in reserve */
rsm = bbr_alloc(bbr);
if (rsm == NULL) {
error = ENOMEM;
/* Lie to get on the hpts */
tot_len = tp->t_maxseg;
if (hpts_calling)
/* Retry in a ms */
slot = 1001;
goto just_return_nolock;
}
TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
bbr->r_ctl.rc_free_cnt++;
rsm = NULL;
}
/* What do we send, a resend? */
if (bbr->r_ctl.rc_resend == NULL) {
/* Check for rack timeout */
bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
if (bbr->r_ctl.rc_resend) {
#ifdef BBR_INVARIANTS
picked_up_retran = 1;
#endif
bbr_cong_signal(tp, NULL, CC_NDUPACK, bbr->r_ctl.rc_resend);
}
}
if (bbr->r_ctl.rc_resend) {
rsm = bbr->r_ctl.rc_resend;
#ifdef BBR_INVARIANTS
doing_retran_from = 1;
#endif
/* Remove any TLP flags its a RACK or T-O */
rsm->r_flags &= ~BBR_TLP;
bbr->r_ctl.rc_resend = NULL;
if (SEQ_LT(rsm->r_start, tp->snd_una)) {
#ifdef BBR_INVARIANTS
panic("Huh, tp:%p bbr:%p rsm:%p start:%u < snd_una:%u\n",
tp, bbr, rsm, rsm->r_start, tp->snd_una);
goto recheck_resend;
#else
/* TSNH */
rsm = NULL;
goto recheck_resend;
#endif
}
rtr_cnt++;
if (rsm->r_flags & BBR_HAS_SYN) {
/* Only retransmit a SYN by itself */
len = 0;
if ((flags & TH_SYN) == 0) {
/* Huh something is wrong */
rsm->r_start++;
if (rsm->r_start == rsm->r_end) {
/* Clean it up, somehow we missed the ack? */
bbr_log_syn(tp, NULL);
} else {
/* TFO with data? */
rsm->r_flags &= ~BBR_HAS_SYN;
len = rsm->r_end - rsm->r_start;
}
} else {
/* Retransmitting SYN */
rsm = NULL;
SOCKBUF_LOCK(sb);
goto send;
}
} else
len = rsm->r_end - rsm->r_start;
if ((bbr->rc_resends_use_tso == 0) &&
#ifdef KERN_TLS
((sb->sb_flags & SB_TLS_IFNET) == 0) &&
#endif
(len > maxseg)) {
len = maxseg;
more_to_rxt = 1;
}
sb_offset = rsm->r_start - tp->snd_una;
if (len > 0) {
sack_rxmit = 1;
TCPSTAT_INC(tcps_sack_rexmits);
TCPSTAT_ADD(tcps_sack_rexmit_bytes,
min(len, maxseg));
} else {
/* I dont think this can happen */
rsm = NULL;
goto recheck_resend;
}
BBR_STAT_INC(bbr_resends_set);
} else if (bbr->r_ctl.rc_tlp_send) {
/*
* Tail loss probe
*/
doing_tlp = 1;
rsm = bbr->r_ctl.rc_tlp_send;
bbr->r_ctl.rc_tlp_send = NULL;
sack_rxmit = 1;
len = rsm->r_end - rsm->r_start;
rtr_cnt++;
if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
len = maxseg;
if (SEQ_GT(tp->snd_una, rsm->r_start)) {
#ifdef BBR_INVARIANTS
panic("tp:%p bbc:%p snd_una:%u rsm:%p r_start:%u",
tp, bbr, tp->snd_una, rsm, rsm->r_start);
#else
/* TSNH */
rsm = NULL;
goto recheck_resend;
#endif
}
sb_offset = rsm->r_start - tp->snd_una;
BBR_STAT_INC(bbr_tlp_set);
}
/*
* Enforce a connection sendmap count limit if set
* as long as we are not retransmiting.
*/
if ((rsm == NULL) &&
(bbr_tcp_map_entries_limit > 0) &&
(bbr->r_ctl.rc_num_maps_alloced >= bbr_tcp_map_entries_limit)) {
BBR_STAT_INC(bbr_alloc_limited);
if (!bbr->alloc_limit_reported) {
bbr->alloc_limit_reported = 1;
BBR_STAT_INC(bbr_alloc_limited_conns);
}
goto just_return_nolock;
}
#ifdef BBR_INVARIANTS
if (rsm && SEQ_LT(rsm->r_start, tp->snd_una)) {
panic("tp:%p bbr:%p rsm:%p sb_offset:%u len:%u",
tp, bbr, rsm, sb_offset, len);
}
#endif
/*
* Get standard flags, and add SYN or FIN if requested by 'hidden'
* state flags.
*/
if (tp->t_flags & TF_NEEDFIN && (rsm == NULL))
flags |= TH_FIN;
if (tp->t_flags & TF_NEEDSYN)
flags |= TH_SYN;
if (rsm && (rsm->r_flags & BBR_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 if we
* allowed data with a FIN.
*/
flags &= ~TH_FIN;
}
} else if (rsm) {
if (flags & TH_FIN)
flags &= ~TH_FIN;
}
if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
void *end_rsm;
end_rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_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) || (sendwin <= (tp->snd_max - tp->snd_una))) {
/*
* 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 ((bbr->rc_in_persist != 0) &&
(tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
bbr_minseg(bbr)))) {
/* Exit persists if there is space */
bbr_exit_persist(tp, bbr, cts, __LINE__);
}
if (rsm == NULL) {
/*
* If we are dropping persist mode then we
* need to correct sb_offset if not a
* retransmit.
*/
sb_offset = tp->snd_max - 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_max, tp->snd_una))
sb_offset = tp->snd_max - tp->snd_una;
else
sb_offset = 0;
if (bbr->rc_tlp_new_data) {
/* TLP is forcing out new data */
uint32_t tlplen;
doing_tlp = 1;
tlplen = maxseg;
if (tlplen > (uint32_t)(avail - sb_offset)) {
tlplen = (uint32_t)(avail - sb_offset);
}
if (tlplen > tp->snd_wnd) {
len = tp->snd_wnd;
} else {
len = tlplen;
}
bbr->rc_tlp_new_data = 0;
} else {
what_we_can = len = bbr_what_can_we_send(tp, bbr, sendwin, avail, sb_offset, cts);
if ((len < p_maxseg) &&
(bbr->rc_in_persist == 0) &&
(ctf_outstanding(tp) >= (2 * p_maxseg)) &&
((avail - sb_offset) >= p_maxseg)) {
/*
* We are not completing whats in the socket
* buffer (i.e. there is at least a segment
* waiting to send) and we have 2 or more
* segments outstanding. There is no sense
* of sending a little piece. Lets defer and
* and wait until we can send a whole
* segment.
*/
len = 0;
}
if ((tp->t_flags & TF_FORCEDATA) && (bbr->rc_in_persist)) {
/*
* We are in persists, figure out if
* a retransmit is available (maybe the previous
* persists we sent) or if we have to send new
* data.
*/
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
if (rsm) {
len = rsm->r_end - rsm->r_start;
if (rsm->r_flags & BBR_HAS_FIN)
len--;
if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
len = maxseg;
if (len > 1)
BBR_STAT_INC(bbr_persist_reneg);
/*
* XXXrrs we could force the len to
* 1 byte here to cause the chunk to
* split apart.. but that would then
* mean we always retransmit it as
* one byte even after the window
* opens.
*/
sack_rxmit = 1;
sb_offset = rsm->r_start - tp->snd_una;
} else {
/*
* First time through in persists or peer
* acked our one byte. Though we do have
* to have something in the sb.
*/
len = 1;
sb_offset = 0;
if (avail == 0)
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) && (rsm == NULL) &&
SEQ_GT(tp->snd_max, tp->snd_una)) {
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++;
if (sbavail(sb) == 0)
len = 0;
} else if ((flags & TH_SYN) && rsm) {
/*
* Subtract one from the len for the SYN being
* retransmitted.
*/
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))) {
len = 0;
sack_rxmit = 0;
rsm = NULL;
}
/* 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)) &&
(tp->snd_una == tp->snd_max) &&
(sb_offset < (int)sbavail(sb))) {
/*
* Not enough room in the rwnd to send
* a paced segment out.
*/
bbr_enter_persist(tp, bbr, cts, __LINE__);
}
} else if ((rsm == NULL) &&
(doing_tlp == 0) &&
(len < bbr->r_ctl.rc_pace_max_segs)) {
/*
* We are not sending a full segment for
* some reason. Should we not send anything (think
* sws or persists)?
*/
if ((tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
(TCPS_HAVEESTABLISHED(tp->t_state)) &&
(len < (int)(sbavail(sb) - sb_offset))) {
/*
* Here the rwnd is less than
* the pacing size, this is not a retransmit,
* we are established and
* the send is not the last in the socket buffer
* lets not send, and possibly enter persists.
*/
len = 0;
if (tp->snd_max == tp->snd_una)
bbr_enter_persist(tp, bbr, cts, __LINE__);
} else if ((tp->snd_cwnd >= bbr->r_ctl.rc_pace_max_segs) &&
(ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(len < bbr_minseg(bbr))) {
/*
* Here we are not retransmitting, and
* the cwnd is not so small that we could
* not send at least a min size (rxt timer
* not having gone off), We have 2 segments or
* more already in flight, its not the tail end
* of the socket buffer and the cwnd is blocking
* us from sending out minimum pacing segment size.
* Lets not send anything.
*/
bbr->rc_cwnd_limited = 1;
len = 0;
} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
(ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(TCPS_HAVEESTABLISHED(tp->t_state))) {
/*
* Here we have a send window but we have
* filled it up and we can't send another pacing segment.
* We also have in flight more than 2 segments
* and we are not completing the sb i.e. we allow
* the last bytes of the sb to go out even if
* its not a full pacing segment.
*/
len = 0;
}
}
/* len will be >= 0 after this point. */
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
tcp_sndbuf_autoscale(tp, so, sendwin);
/*
*
*/
if (bbr->rc_in_persist &&
len &&
(rsm == NULL) &&
(len < min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs))) {
/*
* We are in persist, not doing a retransmit and don't have enough space
* yet to send a full TSO. So is it at the end of the sb
* if so we need to send else nuke to 0 and don't send.
*/
int sbleft;
if (sbavail(sb) > sb_offset)
sbleft = sbavail(sb) - sb_offset;
else
sbleft = 0;
if (sbleft >= min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs)) {
/* not at end of sb lets not send */
len = 0;
}
}
/*
* 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(inp);
else
#endif
if (inp->inp_options)
ipoptlen = inp->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, inp);
#ifdef INET
else
#endif
#endif /* INET6 */
#ifdef INET
if (IPSEC_ENABLED(ipv4))
ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
#endif /* INET */
#endif /* IPSEC */
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
if ((tp->t_flags & TF_TSO) && V_tcp_do_tso &&
(len > maxseg) &&
(tp->t_port == 0) &&
((tp->t_flags & TF_SIGNATURE) == 0) &&
tp->rcv_numsacks == 0 &&
ipoptlen == 0)
tso = 1;
recwin = min(max(sbspace(&so->so_rcv), 0),
TCP_MAXWIN << tp->rcv_scale);
/*
* Sender silly window avoidance. We transmit under the following
* conditions when len is non-zero:
*
* - We have a full segment (or more with TSO) - This is the last
* buffer in a write()/send() and we are either idle or running
* NODELAY - we've timed out (e.g. persist timer) - we have more
* then 1/2 the maximum send window's worth of data (receiver may be
* limited the window size) - we need to retransmit
*/
if (rsm)
goto send;
if (len) {
if (sack_rxmit)
goto send;
if (len >= p_maxseg)
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) == 0) && /* normal case */
((tp->t_flags & TF_NODELAY) ||
((uint32_t)len + (uint32_t)sb_offset) >= sbavail(&so->so_snd)) &&
(tp->t_flags & TF_NOPUSH) == 0) {
goto send;
}
if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
goto send;
}
if (tp->t_flags & TF_FORCEDATA) { /* typ. timeout case */
goto send;
}
if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
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)) {
/* Check to see if we should do a window update */
if (bbr_window_update_needed(tp, so, recwin, maxseg))
goto send;
}
/*
* 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) {
goto send;
}
if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
goto send;
}
if (SEQ_GT(tp->snd_up, tp->snd_una)) {
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->t_flags & TF_SENTFIN) == 0)) {
goto send;
}
/*
* No reason to send a segment, just return.
*/
just_return:
SOCKBUF_UNLOCK(sb);
just_return_nolock:
if (tot_len)
slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
if (bbr->rc_no_pacing)
slot = 0;
if (tot_len == 0) {
if ((ctf_outstanding(tp) + min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) >=
tp->snd_wnd) {
BBR_STAT_INC(bbr_rwnd_limited);
app_limited = BBR_JR_RWND_LIMITED;
bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
if ((bbr->rc_in_persist == 0) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
/* No send window.. we must enter persist */
bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
}
} else if (ctf_outstanding(tp) >= sbavail(sb)) {
BBR_STAT_INC(bbr_app_limited);
app_limited = BBR_JR_APP_LIMITED;
bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
} else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) + p_maxseg) >= tp->snd_cwnd) {
BBR_STAT_INC(bbr_cwnd_limited);
app_limited = BBR_JR_CWND_LIMITED;
bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)));
bbr->rc_cwnd_limited = 1;
} else {
BBR_STAT_INC(bbr_app_limited);
app_limited = BBR_JR_APP_LIMITED;
bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
}
bbr->r_ctl.rc_hptsi_agg_delay = 0;
bbr->r_agg_early_set = 0;
bbr->r_ctl.rc_agg_early = 0;
bbr->r_ctl.rc_last_delay_val = 0;
} else if (bbr->rc_use_google == 0)
bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
/* Are we app limited? */
if ((app_limited == BBR_JR_APP_LIMITED) ||
(app_limited == BBR_JR_RWND_LIMITED)) {
/**
* We are application limited.
*/
bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_delivered);
}
if (tot_len == 0)
counter_u64_add(bbr_out_size[TCP_MSS_ACCT_JUSTRET], 1);
tp->t_flags &= ~TF_FORCEDATA;
/* Dont update the time if we did not send */
bbr->r_ctl.rc_last_delay_val = 0;
bbr->rc_output_starts_timer = 1;
bbr_start_hpts_timer(bbr, tp, cts, 9, slot, tot_len);
bbr_log_type_just_return(bbr, cts, tot_len, hpts_calling, app_limited, p_maxseg, len);
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
/* Make sure snd_nxt is drug up */
tp->snd_nxt = tp->snd_max;
}
return (error);
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.
*/
bbr->rc_tlp_in_progress = 0;
bbr->rc_tlp_rtx_out = 0;
} else {
/*
* Its a TLP.
*/
bbr->rc_tlp_in_progress = 1;
}
bbr_timer_cancel(bbr, __LINE__, cts);
if (rsm == NULL) {
if (sbused(sb) > 0) {
/*
* This is sub-optimal. We only send a stand alone
* FIN on its own segment.
*/
if (flags & TH_FIN) {
flags &= ~TH_FIN;
if ((len == 0) && ((tp->t_flags & TF_ACKNOW) == 0)) {
/* Lets not send this */
slot = 0;
goto just_return;
}
}
}
} else {
/*
* We do *not* send a FIN on a retransmit if it has data.
* The if clause here where len > 1 should never come true.
*/
if ((len > 0) &&
(((rsm->r_flags & BBR_HAS_FIN) == 0) &&
(flags & TH_FIN))) {
flags &= ~TH_FIN;
len--;
}
}
SOCKBUF_LOCK_ASSERT(sb);
if (len > 0) {
if ((tp->snd_una == tp->snd_max) &&
(bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
/*
* This qualifies as a RTT_PROBE session since we
* drop the data outstanding to nothing and waited
* more than bbr_rtt_probe_time.
*/
bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
bbr_set_reduced_rtt(bbr, cts, __LINE__);
}
if (len >= 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;
local_options = 0;
if ((tp->t_flags & TF_NOOPT) == 0) {
/* Maximum segment size. */
if (flags & TH_SYN) {
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;
}
}
}
/* 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 = tcp_tv_to_mssectick(&bbr->rc_tv) + tp->ts_offset;
to.to_tsecr = tp->ts_recent;
to.to_flags |= TOF_TS;
local_options += TCPOLEN_TIMESTAMP + 2;
}
/* Set receive buffer autosizing timestamp. */
if (tp->rfbuf_ts == 0 &&
(so->so_rcv.sb_flags & SB_AUTOSIZE))
tp->rfbuf_ts = tcp_tv_to_mssectick(&bbr->rc_tv);
/* Selective ACK's. */
if (flags & TH_SYN)
to.to_flags |= TOF_SACKPERM;
else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
tp->rcv_numsacks > 0) {
to.to_flags |= TOF_SACK;
to.to_nsacks = tp->rcv_numsacks;
to.to_sacks = (u_char *)tp->sackblks;
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/* TCP-MD5 (RFC2385). */
if (tp->t_flags & TF_SIGNATURE)
to.to_flags |= TOF_SIGNATURE;
#endif /* TCP_SIGNATURE */
/* Processing the options. */
hdrlen += (optlen = tcp_addoptions(&to, opt));
/*
* If we wanted a TFO option to be added, but it was unable
* to fit, ensure no data is sent.
*/
if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
!(to.to_flags & TOF_FASTOPEN))
len = 0;
}
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
if (V_tcp_udp_tunneling_port == 0) {
/* The port was removed?? */
SOCKBUF_UNLOCK(&so->so_snd);
return (EHOSTUNREACH);
}
hdrlen += sizeof(struct udphdr);
}
#endif
#ifdef INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
if (tp->t_inpcb->inp_options)
ipoptlen = tp->t_inpcb->inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
else
ipoptlen = 0;
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
if (bbr->rc_last_options != local_options) {
/*
* Cache the options length this generally does not change
* on a connection. We use this to calculate TSO.
*/
bbr->rc_last_options = local_options;
}
maxseg = tp->t_maxseg - (ipoptlen + optlen);
p_maxseg = min(maxseg, pace_max_segs);
/*
* 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.
*/
#ifdef KERN_TLS
/* force TSO for so TLS offload can get mss */
if (sb->sb_flags & SB_TLS_IFNET) {
force_tso = 1;
}
#endif
if (len > maxseg) {
if (len != 0 && (flags & TH_FIN)) {
flags &= ~TH_FIN;
}
if (tso) {
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) {
len = max_len;
}
}
/*
* Prevent the last segment from being fractional
* unless the send sockbuf can be emptied:
*/
if (((sb_offset + len) < sbavail(sb)) &&
(hw_tls == 0)) {
moff = len % (uint32_t)maxseg;
if (moff != 0) {
len -= moff;
}
}
/*
* In case there are too many small fragments don't
* use TSO:
*/
if (len <= maxseg) {
len = maxseg;
tso = 0;
}
} else {
/* Not doing TSO */
if (optlen + ipoptlen >= tp->t_maxseg) {
/*
* Since we don't have enough space to put
* the IP header chain and the TCP header in
* one packet as required by RFC 7112, don't
* send it. Also ensure that at least one
* byte of the payload can be put into the
* TCP segment.
*/
SOCKBUF_UNLOCK(&so->so_snd);
error = EMSGSIZE;
sack_rxmit = 0;
goto out;
}
len = maxseg;
}
} else {
/* Not doing TSO */
if_hw_tsomaxsegcount = 0;
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.
*/
#ifdef BBR_INVARIANTS
if (sack_rxmit) {
if (SEQ_LT(rsm->r_start, tp->snd_una)) {
panic("RSM:%p TP:%p bbr:%p start:%u is < snd_una:%u",
rsm, tp, bbr, rsm->r_start, tp->snd_una);
}
}
#endif
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!.
*/
slot = 0;
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 moff;
uint32_t orig_len;
/*
* We place a limit on sending with hptsi.
*/
if ((rsm == NULL) && len > pace_max_segs)
len = pace_max_segs;
if (len <= maxseg)
tso = 0;
#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) {
BBR_STAT_INC(bbr_failed_mbuf_aloc);
bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
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.
*/
if ((sb_offset > sbavail(sb)) || ((len + sb_offset) > sbavail(sb))) {
#ifdef BBR_INVARIANTS
if ((len + sb_offset) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0)))
panic("tp:%p bbr:%p len:%u sb_offset:%u sbavail:%u rsm:%p %u:%u:%u",
tp, bbr, len, sb_offset, sbavail(sb), rsm,
doing_retran_from,
picked_up_retran,
doing_tlp);
#endif
/*
* In this messed up situation we have two choices,
* a) pretend the send worked, and just start timers
* and what not (not good since that may lead us
* back here a lot). <or> b) Send the lowest segment
* in the map. <or> c) Drop the connection. Lets do
* <b> which if it continues to happen will lead to
* <c> via timeouts.
*/
BBR_STAT_INC(bbr_offset_recovery);
rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
sb_offset = 0;
if (rsm == NULL) {
sack_rxmit = 0;
len = sbavail(sb);
} else {
sack_rxmit = 1;
if (rsm->r_start != tp->snd_una) {
/*
* Things are really messed up, <c>
* is the only thing to do.
*/
BBR_STAT_INC(bbr_offset_drop);
tcp_set_inp_to_drop(inp, EFAULT);
return (0);
}
len = rsm->r_end - rsm->r_start;
}
if (len > sbavail(sb))
len = sbavail(sb);
if (len > maxseg)
len = maxseg;
}
mb = sbsndptr_noadv(sb, sb_offset, &moff);
if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
m_copydata(mb, moff, (int)len,
mtod(m, caddr_t)+hdrlen);
if (rsm == NULL)
sbsndptr_adv(sb, mb, len);
m->m_len += len;
} else {
struct sockbuf *msb;
if (rsm)
msb = NULL;
else
msb = sb;
#ifdef BBR_INVARIANTS
if ((len + moff) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0))) {
if (rsm) {
panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u rsm:%p snd_una:%u rsm_start:%u flg:%x %u:%u:%u sr:%d ",
tp, bbr, len, moff,
sbavail(sb), rsm,
tp->snd_una, rsm->r_flags, rsm->r_start,
doing_retran_from,
picked_up_retran,
doing_tlp, sack_rxmit);
} else {
panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u sb_offset:%u snd_una:%u",
tp, bbr, len, moff, sbavail(sb), sb_offset, tp->snd_una);
}
}
#endif
orig_len = len;
m->m_next = tcp_m_copym(
#ifdef NETFLIX_COPY_ARGS
tp,
#endif
mb, moff, &len,
if_hw_tsomaxsegcount,
if_hw_tsomaxsegsize, msb,
((rsm == NULL) ? hw_tls : 0)
#ifdef NETFLIX_COPY_ARGS
, &filled_all
#endif
);
if (len <= maxseg && !force_tso) {
/*
* 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;
}
}
#ifdef BBR_INVARIANTS
if (tso && len < maxseg) {
panic("tp:%p tso on, but len:%d < maxseg:%d",
tp, len, maxseg);
}
if (tso && if_hw_tsomaxsegcount) {
int32_t seg_cnt = 0;
struct mbuf *foo;
foo = m;
while (foo) {
seg_cnt++;
foo = foo->m_next;
}
if (seg_cnt > if_hw_tsomaxsegcount) {
panic("seg_cnt:%d > max:%d", seg_cnt, if_hw_tsomaxsegcount);
}
}
#endif
/*
* If we're sending everything we've got, set PUSH. (This
* will keep happy those implementations which only give
* data to the user when a buffer fills or a PUSH comes in.)
*/
if (sb_offset + len == sbused(sb) &&
sbused(sb) &&
!(flags & TH_SYN)) {
flags |= TH_PUSH;
}
SOCKBUF_UNLOCK(sb);
} else {
SOCKBUF_UNLOCK(sb);
if (tp->t_flags & TF_ACKNOW)
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) {
BBR_STAT_INC(bbr_failed_mbuf_aloc);
bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
error = ENOBUFS;
/* Fudge the send time since we could not send */
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);
#ifdef NETFLIX_TCPOUDP
}
#endif
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip6, th);
} else
#endif /* INET6 */
{
ip = mtod(m, struct ip *);
#ifdef TCPDEBUG
ipov = (struct ipovly *)ip;
#endif
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = tp->t_port;
ulen = hdrlen + len - sizeof(struct ip);
udp->uh_ulen = htons(ulen);
th = (struct tcphdr *)(udp + 1);
} else
#endif
th = (struct tcphdr *)(ip + 1);
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip, th);
}
/*
* 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_FIN | TH_SYN | TH_RST)) == 0)) {
/* New data (including new persists) */
th->th_seq = htonl(tp->snd_max);
bbr_seq = tp->snd_max;
} else if (flags & TH_SYN) {
/* Syn's always send from iss */
th->th_seq = htonl(tp->iss);
bbr_seq = tp->iss;
} else if (flags & TH_FIN) {
if (flags & TH_FIN && tp->t_flags & TF_SENTFIN) {
/*
* If we sent the fin already its 1 minus
* snd_max
*/
th->th_seq = (htonl(tp->snd_max - 1));
bbr_seq = (tp->snd_max - 1);
} else {
/* First time FIN use snd_max */
th->th_seq = htonl(tp->snd_max);
bbr_seq = tp->snd_max;
}
} 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);
bbr_seq = tp->snd_una;
} else {
/*
* len == 0 and not persist we use snd_max, sending
* an ack unless we have sent the fin then its 1
* minus.
*/
/*
* XXXRRS Question if we are in persists and we have
* nothing outstanding to send and we have not sent
* a FIN, we will send an ACK. In such a case it
* might be better to send (tp->snd_una - 1) which
* would force the peer to ack.
*/
if (tp->t_flags & TF_SENTFIN) {
th->th_seq = htonl(tp->snd_max - 1);
bbr_seq = (tp->snd_max - 1);
} else {
th->th_seq = htonl(tp->snd_max);
bbr_seq = tp->snd_max;
}
}
} else {
/* All retransmits use the rsm to guide the send */
th->th_seq = htonl(rsm->r_start);
bbr_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 ((flags & TH_RST) || ((recwin < (so->so_rcv.sb_hiwat / 4) &&
recwin < maxseg)))
recwin = 0;
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
recwin < (tp->rcv_adv - tp->rcv_nxt))
recwin = (tp->rcv_adv - tp->rcv_nxt);
if (recwin > TCP_MAXWIN << tp->rcv_scale)
recwin = 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_max)) {
th->th_urp = htons((u_short)(tp->snd_up - tp->snd_max));
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.
*/
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
#endif
csum_flags = 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);
#ifdef NETFLIX_TCPOUDP
}
#endif
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
#endif
csum_flags = 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));
#ifdef NETFLIX_TCPOUDP
}
#endif
/* IP version must be set here for ipv4/ipv6 checking later */
KASSERT(ip->ip_v == IPVERSION,
("%s: IP version incorrect: %d", __func__, ip->ip_v));
}
#endif
/*
* Enable TSO and specify the size of the segments. The TCP pseudo
* header checksum is always provided. XXX: Fixme: This is currently
* not the case for IPv6.
*/
if (tso || force_tso) {
KASSERT(force_tso || len > maxseg,
("%s: len:%d <= tso_segsz:%d", __func__, len, maxseg));
m->m_pkthdr.csum_flags |= CSUM_TSO;
csum_flags |= CSUM_TSO;
m->m_pkthdr.tso_segsz = maxseg;
}
KASSERT(len + hdrlen == m_length(m, NULL),
("%s: mbuf chain different than expected: %d + %u != %u",
__func__, len, hdrlen, m_length(m, NULL)));
#ifdef TCP_HHOOK
/* Run HHOOK_TC_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 */
/* Log to the black box */
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
/* Record info on type of transmission */
log.u_bbr.flex1 = bbr->r_ctl.rc_hptsi_agg_delay;
log.u_bbr.flex2 = (bbr->r_recovery_bw << 3);
log.u_bbr.flex3 = maxseg;
log.u_bbr.flex4 = delay_calc;
/* Encode filled_all into the upper flex5 bit */
log.u_bbr.flex5 = bbr->rc_past_init_win;
log.u_bbr.flex5 <<= 1;
log.u_bbr.flex5 |= bbr->rc_no_pacing;
log.u_bbr.flex5 <<= 29;
if (filled_all)
log.u_bbr.flex5 |= 0x80000000;
log.u_bbr.flex5 |= tp->t_maxseg;
log.u_bbr.flex6 = bbr->r_ctl.rc_pace_max_segs;
log.u_bbr.flex7 = (bbr->rc_bbr_state << 8) | bbr_state_val(bbr);
/* lets poke in the low and the high here for debugging */
log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
if (rsm || sack_rxmit) {
if (doing_tlp)
log.u_bbr.flex8 = 2;
else
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, tv);
} else {
lgb = NULL;
}
/*
* Fill in IP length and desired time to live and send to IP level.
* There should be a better way to handle ttl and tos; we could keep
* them in the template, but need a way to checksum without them.
*/
/*
* m->m_pkthdr.len should have been set before cksum calcuration,
* because in6_cksum() need it.
*/
#ifdef INET6
if (isipv6) {
/*
* we separately set hoplimit for every segment, since the
* user might want to change the value via setsockopt. Also,
* desired default hop limit might be changed via Neighbor
* Discovery.
*/
ip6->ip6_hlim = in6_selecthlim(inp, NULL);
/*
* Set the packet size here for the benefit of DTrace
* probes. ip6_output() will set it properly; it's supposed
* to include the option header lengths as well.
*/
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
if (V_path_mtu_discovery && maxseg > V_tcp_minmss)
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
else
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
TCP_PROBE5(send, NULL, tp, ip6, tp, th);
/* TODO: IPv6 IP6TOS_ECT bit on */
error = ip6_output(m, inp->in6p_outputopts,
&inp->inp_route6,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
NULL, NULL, inp);
if (error == EMSGSIZE && inp->inp_route6.ro_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 (isipv6)
ip->ip_ttl = in6_selecthlim(inp, NULL);
#endif /* INET6 */
/*
* If we do path MTU discovery, then we set DF on every
* packet. This might not be the best thing to do according
* to RFC3390 Section 2. However the tcp hostcache migitates
* the problem so it affects only the first tcp connection
* with a host.
*
* NB: Don't set DF on small MTU/MSS to have a safe
* fallback.
*/
if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
if (tp->t_port == 0 || len < V_tcp_minmss) {
ip->ip_off |= htons(IP_DF);
}
} else {
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
}
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
TCP_PROBE5(send, NULL, tp, ip, tp, th);
error = ip_output(m, inp->inp_options, &inp->inp_route,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
inp);
if (error == EMSGSIZE && inp->inp_route.ro_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 (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->t_flags & TF_SACK_PERMIT) &&
tp->rcv_numsacks > 0)
tcp_clean_dsack_blocks(tp);
/* We sent an ack clear the bbr_segs_rcvd count */
bbr->output_error_seen = 0;
bbr->oerror_cnt = 0;
bbr->bbr_segs_rcvd = 0;
if (len == 0)
counter_u64_add(bbr_out_size[TCP_MSS_ACCT_SNDACK], 1);
else if (hw_tls) {
if (filled_all ||
(len >= bbr->r_ctl.rc_pace_max_segs))
BBR_STAT_INC(bbr_meets_tso_thresh);
else {
if (doing_tlp) {
BBR_STAT_INC(bbr_miss_tlp);
bbr_log_type_hrdwtso(tp, bbr, len, 1, what_we_can);
} else if (rsm) {
BBR_STAT_INC(bbr_miss_retran);
bbr_log_type_hrdwtso(tp, bbr, len, 2, what_we_can);
} else if ((ctf_outstanding(tp) + bbr->r_ctl.rc_pace_max_segs) > sbavail(sb)) {
BBR_STAT_INC(bbr_miss_tso_app);
bbr_log_type_hrdwtso(tp, bbr, len, 3, what_we_can);
} else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_pace_max_segs) > tp->snd_cwnd) {
BBR_STAT_INC(bbr_miss_tso_cwnd);
bbr_log_type_hrdwtso(tp, bbr, len, 4, what_we_can);
} else if ((ctf_outstanding(tp) + bbr->r_ctl.rc_pace_max_segs) > tp->snd_wnd) {
BBR_STAT_INC(bbr_miss_tso_rwnd);
bbr_log_type_hrdwtso(tp, bbr, len, 5, what_we_can);
} else {
BBR_STAT_INC(bbr_miss_unknown);
bbr_log_type_hrdwtso(tp, bbr, len, 6, what_we_can);
}
}
}
/* Do accounting for new sends */
if ((len > 0) && (rsm == NULL)) {
int idx;
if (tp->snd_una == tp->snd_max) {
/*
* Special case to match google, when
* nothing is in flight the delivered
* time does get updated to the current
* time (see tcp_rate_bsd.c).
*/
bbr->r_ctl.rc_del_time = cts;
}
if (len >= maxseg) {
idx = (len / maxseg) + 3;
if (idx >= TCP_MSS_ACCT_ATIMER)
counter_u64_add(bbr_out_size[(TCP_MSS_ACCT_ATIMER - 1)], 1);
else
counter_u64_add(bbr_out_size[idx], 1);
} else {
/* smaller than a MSS */
idx = len / (bbr_hptsi_bytes_min - bbr->rc_last_options);
if (idx >= TCP_MSS_SMALL_MAX_SIZE_DIV)
idx = (TCP_MSS_SMALL_MAX_SIZE_DIV - 1);
counter_u64_add(bbr_out_size[(idx + TCP_MSS_SMALL_SIZE_OFF)], 1);
}
}
}
abandon = 0;
/*
* We must do the send accounting before we log the output,
* otherwise the state of the rsm could change and we account to the
* wrong bucket.
*/
if (len > 0) {
bbr_do_send_accounting(tp, bbr, rsm, len, error);
if (error == 0) {
if (tp->snd_una == tp->snd_max)
bbr->r_ctl.rc_tlp_rxt_last_time = cts;
}
}
bbr_log_output(bbr, tp, &to, len, bbr_seq, (uint8_t) flags, error,
cts, mb, &abandon, rsm, 0, sb);
if (abandon) {
/*
* If bbr_log_output destroys the TCB or sees a TH_RST being
* sent we should hit this condition.
*/
return (0);
}
if (((tp->t_flags & TF_FORCEDATA) == 0) ||
(bbr->rc_in_persist == 0)) {
/*
* Advance snd_nxt over sequence space of this segment.
*/
if (error)
/* We don't log or do anything with errors */
goto skip_upd;
if (tp->snd_una == tp->snd_max &&
(len || (flags & (TH_SYN | TH_FIN)))) {
/*
* Update the time we just added data since none was
* outstanding.
*/
bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
bbr->rc_tp->t_acktime = ticks;
}
if (flags & (TH_SYN | TH_FIN) && (rsm == NULL)) {
if (flags & TH_SYN) {
tp->snd_max++;
}
if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
tp->snd_max++;
tp->t_flags |= TF_SENTFIN;
}
}
if (sack_rxmit == 0)
tp->snd_max += len;
skip_upd:
if ((error == 0) && len)
tot_len += len;
} else {
/* Persists case */
int32_t xlen = len;
if (error)
goto nomore;
if (flags & TH_SYN)
++xlen;
if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
++xlen;
tp->t_flags |= TF_SENTFIN;
}
if (xlen && (tp->snd_una == tp->snd_max)) {
/*
* Update the time we just added data since none was
* outstanding.
*/
bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
bbr->rc_tp->t_acktime = ticks;
}
if (sack_rxmit == 0)
tp->snd_max += xlen;
tot_len += (len + optlen + ipoptlen);
}
nomore:
if (error) {
/*
* Failures do not advance the seq counter above. For the
* case of ENOBUFS we will fall out and become ack-clocked.
* capping the cwnd at the current flight.
* Everything else will just have to retransmit with the timer
* (no pacer).
*/
SOCKBUF_UNLOCK_ASSERT(sb);
BBR_STAT_INC(bbr_saw_oerr);
/* Clear all delay/early tracks */
bbr->r_ctl.rc_hptsi_agg_delay = 0;
bbr->r_ctl.rc_agg_early = 0;
bbr->r_agg_early_set = 0;
bbr->output_error_seen = 1;
if (bbr->oerror_cnt < 0xf)
bbr->oerror_cnt++;
if (bbr_max_net_error_cnt && (bbr->oerror_cnt >= bbr_max_net_error_cnt)) {
/* drop the session */
tcp_set_inp_to_drop(inp, ENETDOWN);
}
switch (error) {
case ENOBUFS:
/*
* Make this guy have to get ack's to send
* more but lets make sure we don't
* slam him below a T-O (1MSS).
*/
if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
tp->snd_cwnd = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)) - maxseg;
if (tp->snd_cwnd < maxseg)
tp->snd_cwnd = maxseg;
}
slot = (bbr_error_base_paceout + 1) << bbr->oerror_cnt;
BBR_STAT_INC(bbr_saw_enobuf);
if (bbr->bbr_hdrw_pacing)
counter_u64_add(bbr_hdwr_pacing_enobuf, 1);
else
counter_u64_add(bbr_nohdwr_pacing_enobuf, 1);
/*
* Here even in the enobuf's case we want to do our
* state update. The reason being we may have been
* called by the input function. If so we have had
* things change.
*/
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.
*/
/* Turn on tracing (or try to) */
{
int old_maxseg;
old_maxseg = tp->t_maxseg;
BBR_STAT_INC(bbr_saw_emsgsiz);
bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, csum_flags, tso, cts);
if (mtu != 0)
tcp_mss_update(tp, -1, mtu, NULL, NULL);
if (old_maxseg <= tp->t_maxseg) {
/* Huh it did not shrink? */
tp->t_maxseg = old_maxseg - 40;
bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, 0, tso, cts);
}
tp->t_flags &= ~TF_FORCEDATA;
/*
* Nuke all other things that can interfere
* with slot
*/
if ((tot_len + len) && (len >= tp->t_maxseg)) {
slot = bbr_get_pacing_delay(bbr,
bbr->r_ctl.rc_bbr_hptsi_gain,
(tot_len + len), cts, 0);
if (slot < bbr_error_base_paceout)
slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
} else
slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
bbr->rc_output_starts_timer = 1;
bbr_start_hpts_timer(bbr, tp, cts, 10, slot,
tot_len);
return (error);
}
case EPERM:
tp->t_softerror = error;
/* Fall through */
case EHOSTDOWN:
case EHOSTUNREACH:
case ENETDOWN:
case ENETUNREACH:
if (TCPS_HAVERCVDSYN(tp->t_state)) {
tp->t_softerror = error;
}
/* FALLTHROUGH */
default:
tp->t_flags &= ~TF_FORCEDATA;
slot = (bbr_error_base_paceout + 3) << bbr->oerror_cnt;
bbr->rc_output_starts_timer = 1;
bbr_start_hpts_timer(bbr, tp, cts, 11, slot, 0);
return (error);
}
#ifdef NETFLIX_STATS
} else if (((tp->t_flags & TF_GPUTINPROG) == 0) &&
len &&
(rsm == NULL) &&
(bbr->rc_in_persist == 0)) {
tp->gput_seq = bbr_seq;
tp->gput_ack = bbr_seq +
min(sbavail(&so->so_snd) - sb_offset, sendwin);
tp->gput_ts = cts;
tp->t_flags |= TF_GPUTINPROG;
#endif
}
TCPSTAT_INC(tcps_sndtotal);
if ((bbr->bbr_hdw_pace_ena) &&
(bbr->bbr_attempt_hdwr_pace == 0) &&
(bbr->rc_past_init_win) &&
(bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
(get_filter_value(&bbr->r_ctl.rc_delrate)) &&
(inp->inp_route.ro_rt &&
inp->inp_route.ro_rt->rt_ifp)) {
/*
* We are past the initial window and
* have at least one measurement so we
* could use hardware pacing if its available.
* We have an interface and we have not attempted
* to setup hardware pacing, lets try to now.
*/
uint64_t rate_wanted;
int err = 0;
rate_wanted = bbr_get_hardware_rate(bbr);
bbr->bbr_attempt_hdwr_pace = 1;
bbr->r_ctl.crte = tcp_set_pacing_rate(bbr->rc_tp,
inp->inp_route.ro_rt->rt_ifp,
rate_wanted,
(RS_PACING_GEQ|RS_PACING_SUB_OK),
&err);
if (bbr->r_ctl.crte) {
bbr_type_log_hdwr_pacing(bbr,
bbr->r_ctl.crte->ptbl->rs_ifp,
rate_wanted,
bbr->r_ctl.crte->rate,
__LINE__, cts, err);
BBR_STAT_INC(bbr_hdwr_rl_add_ok);
counter_u64_add(bbr_flows_nohdwr_pacing, -1);
counter_u64_add(bbr_flows_whdwr_pacing, 1);
bbr->bbr_hdrw_pacing = 1;
/* Now what is our gain status? */
if (bbr->r_ctl.crte->rate < rate_wanted) {
/* We have a problem */
bbr_setup_less_of_rate(bbr, cts,
bbr->r_ctl.crte->rate, rate_wanted);
} else {
/* We are good */
bbr->gain_is_limited = 0;
bbr->skip_gain = 0;
}
tcp_bbr_tso_size_check(bbr, cts);
} else {
bbr_type_log_hdwr_pacing(bbr,
inp->inp_route.ro_rt->rt_ifp,
rate_wanted,
0,
__LINE__, cts, err);
BBR_STAT_INC(bbr_hdwr_rl_add_fail);
}
}
if (bbr->bbr_hdrw_pacing) {
/*
* Worry about cases where the route
* changes or something happened that we
* lost our hardware pacing possibly during
* the last ip_output call.
*/
if (inp->inp_snd_tag == NULL) {
/* A change during ip output disabled hw pacing? */
bbr->bbr_hdrw_pacing = 0;
} else if ((inp->inp_route.ro_rt == NULL) ||
(inp->inp_route.ro_rt->rt_ifp != inp->inp_snd_tag->ifp)) {
/*
* We had an interface or route change,
* detach from the current hdwr pacing
* and setup to re-attempt next go
* round.
*/
bbr->bbr_hdrw_pacing = 0;
bbr->bbr_attempt_hdwr_pace = 0;
tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
tcp_bbr_tso_size_check(bbr, cts);
}
}
/*
* 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 (SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
tp->rcv_adv = tp->rcv_nxt + recwin;
tp->last_ack_sent = tp->rcv_nxt;
if ((error == 0) &&
(bbr->r_ctl.rc_pace_max_segs > tp->t_maxseg) &&
(doing_tlp == 0) &&
(tso == 0) &&
(hw_tls == 0) &&
(len > 0) &&
((flags & TH_RST) == 0) &&
(IN_RECOVERY(tp->t_flags) == 0) &&
(bbr->rc_in_persist == 0) &&
((tp->t_flags & TF_FORCEDATA) == 0) &&
(tot_len < bbr->r_ctl.rc_pace_max_segs)) {
/*
* For non-tso we need to goto again until we have sent out
* enough data to match what we are hptsi out every hptsi
* interval.
*/
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
/* Make sure snd_nxt is drug up */
tp->snd_nxt = tp->snd_max;
}
if (rsm != NULL) {
rsm = NULL;
goto skip_again;
}
rsm = NULL;
sack_rxmit = 0;
tp->t_flags &= ~(TF_ACKNOW | TF_DELACK | TF_FORCEDATA);
goto again;
}
skip_again:
if (((flags & (TH_RST | TH_SYN | TH_FIN)) == 0) && tot_len) {
/*
* Calculate/Re-Calculate the hptsi slot in usecs based on
* what we have sent so far
*/
slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
if (bbr->rc_no_pacing)
slot = 0;
}
tp->t_flags &= ~(TF_ACKNOW | TF_DELACK | TF_FORCEDATA);
enobufs:
if (bbr->rc_use_google == 0)
bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
bbr->r_ctl.rc_lost_bytes)));
bbr->rc_output_starts_timer = 1;
if (bbr->bbr_use_rack_cheat &&
(more_to_rxt ||
((bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts)) != NULL))) {
/* Rack cheats and shotguns out all rxt's 1ms apart */
if (slot > 1000)
slot = 1000;
}
if (bbr->bbr_hdrw_pacing && (bbr->hw_pacing_set == 0)) {
/*
* We don't change the tso size until some number of sends
* to give the hardware commands time to get down
* to the interface.
*/
bbr->r_ctl.bbr_hdwr_cnt_noset_snt++;
if (bbr->r_ctl.bbr_hdwr_cnt_noset_snt >= bbr_hdwr_pacing_delay_cnt) {
bbr->hw_pacing_set = 1;
tcp_bbr_tso_size_check(bbr, cts);
}
}
bbr_start_hpts_timer(bbr, tp, cts, 12, slot, tot_len);
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
/* Make sure snd_nxt is drug up */
tp->snd_nxt = tp->snd_max;
}
return (error);
}
/*
* See bbr_output_wtime() for return values.
*/
static int
bbr_output(struct tcpcb *tp)
{
int32_t ret;
struct timeval tv;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
(void)tcp_get_usecs(&tv);
ret = bbr_output_wtime(tp, &tv);
return (ret);
}
static void
bbr_mtu_chg(struct tcpcb *tp)
{
struct tcp_bbr *bbr;
struct bbr_sendmap *rsm, *frsm = NULL;
uint32_t maxseg;
/*
* The MTU has changed. a) Clear the sack filter. b) Mark everything
* over the current size as SACK_PASS so a retransmit will occur.
*/
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
maxseg = tp->t_maxseg - bbr->rc_last_options;
sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
/* Don't mess with ones acked (by sack?) */
if (rsm->r_flags & BBR_ACKED)
continue;
if ((rsm->r_end - rsm->r_start) > maxseg) {
/*
* We mark sack-passed on all the previous large
* sends we did. This will force them to retransmit.
*/
rsm->r_flags |= BBR_SACK_PASSED;
if (((rsm->r_flags & BBR_MARKED_LOST) == 0) &&
bbr_is_lost(bbr, rsm, bbr->r_ctl.rc_rcvtime)) {
bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
rsm->r_flags |= BBR_MARKED_LOST;
}
if (frsm == NULL)
frsm = rsm;
}
}
if (frsm) {
bbr->r_ctl.rc_resend = frsm;
}
}
/*
* bbr_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
bbr_set_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_bbr *bbr)
{
int32_t error = 0, optval;
switch (sopt->sopt_name) {
case TCP_RACK_PACE_MAX_SEG:
case TCP_RACK_MIN_TO:
case TCP_RACK_REORD_THRESH:
case TCP_RACK_REORD_FADE:
case TCP_RACK_TLP_THRESH:
case TCP_RACK_PKT_DELAY:
case TCP_BBR_ALGORITHM:
case TCP_BBR_TSLIMITS:
case TCP_BBR_IWINTSO:
case TCP_BBR_RECFORCE:
case TCP_BBR_STARTUP_PG:
case TCP_BBR_DRAIN_PG:
case TCP_BBR_RWND_IS_APP:
case TCP_BBR_PROBE_RTT_INT:
case TCP_BBR_PROBE_RTT_GAIN:
case TCP_BBR_PROBE_RTT_LEN:
case TCP_BBR_STARTUP_LOSS_EXIT:
case TCP_BBR_USEDEL_RATE:
case TCP_BBR_MIN_RTO:
case TCP_BBR_MAX_RTO:
case TCP_BBR_PACE_PER_SEC:
case TCP_DELACK:
case TCP_BBR_PACE_DEL_TAR:
case TCP_BBR_SEND_IWND_IN_TSO:
case TCP_BBR_EXTRA_STATE:
case TCP_BBR_UTTER_MAX_TSO:
case TCP_BBR_MIN_TOPACEOUT:
case TCP_BBR_FLOOR_MIN_TSO:
case TCP_BBR_TSTMP_RAISES:
case TCP_BBR_POLICER_DETECT:
case TCP_BBR_USE_RACK_CHEAT:
case TCP_DATA_AFTER_CLOSE:
case TCP_BBR_HDWR_PACE:
case TCP_BBR_PACE_SEG_MAX:
case TCP_BBR_PACE_SEG_MIN:
case TCP_BBR_PACE_CROSS:
case TCP_BBR_PACE_OH:
#ifdef NETFLIX_PEAKRATE
case TCP_MAXPEAKRATE:
#endif
case TCP_BBR_TMR_PACE_OH:
case TCP_BBR_RACK_RTT_USE:
case TCP_BBR_RETRAN_WTSO:
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);
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
switch (sopt->sopt_name) {
case TCP_BBR_PACE_PER_SEC:
BBR_OPTS_INC(tcp_bbr_pace_per_sec);
bbr->r_ctl.bbr_hptsi_per_second = optval;
break;
case TCP_BBR_PACE_DEL_TAR:
BBR_OPTS_INC(tcp_bbr_pace_del_tar);
bbr->r_ctl.bbr_hptsi_segments_delay_tar = optval;
break;
case TCP_BBR_PACE_SEG_MAX:
BBR_OPTS_INC(tcp_bbr_pace_seg_max);
bbr->r_ctl.bbr_hptsi_segments_max = optval;
break;
case TCP_BBR_PACE_SEG_MIN:
BBR_OPTS_INC(tcp_bbr_pace_seg_min);
bbr->r_ctl.bbr_hptsi_bytes_min = optval;
break;
case TCP_BBR_PACE_CROSS:
BBR_OPTS_INC(tcp_bbr_pace_cross);
bbr->r_ctl.bbr_cross_over = optval;
break;
case TCP_BBR_ALGORITHM:
BBR_OPTS_INC(tcp_bbr_algorithm);
if (optval && (bbr->rc_use_google == 0)) {
/* Turn on the google mode */
bbr_google_mode_on(bbr);
if ((optval > 3) && (optval < 500)) {
/*
* Must be at least greater than .3%
* and must be less than 50.0%.
*/
bbr->r_ctl.bbr_google_discount = optval;
}
} else if ((optval == 0) && (bbr->rc_use_google == 1)) {
/* Turn off the google mode */
bbr_google_mode_off(bbr);
}
break;
case TCP_BBR_TSLIMITS:
BBR_OPTS_INC(tcp_bbr_tslimits);
if (optval == 1)
bbr->rc_use_ts_limit = 1;
else if (optval == 0)
bbr->rc_use_ts_limit = 0;
else
error = EINVAL;
break;
case TCP_BBR_IWINTSO:
BBR_OPTS_INC(tcp_bbr_iwintso);
if ((optval >= 0) && (optval < 128)) {
uint32_t twin;
bbr->rc_init_win = optval;
twin = bbr_initial_cwnd(bbr, tp);
if ((bbr->rc_past_init_win == 0) && (twin > tp->snd_cwnd))
tp->snd_cwnd = twin;
else
error = EBUSY;
} else
error = EINVAL;
break;
case TCP_BBR_STARTUP_PG:
BBR_OPTS_INC(tcp_bbr_startup_pg);
if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE)) {
bbr->r_ctl.rc_startup_pg = optval;
if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
bbr->r_ctl.rc_bbr_hptsi_gain = optval;
}
} else
error = EINVAL;
break;
case TCP_BBR_DRAIN_PG:
BBR_OPTS_INC(tcp_bbr_drain_pg);
if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE))
bbr->r_ctl.rc_drain_pg = optval;
else
error = EINVAL;
break;
case TCP_BBR_PROBE_RTT_LEN:
BBR_OPTS_INC(tcp_bbr_probertt_len);
if (optval <= 1)
reset_time_small(&bbr->r_ctl.rc_rttprop, (optval * USECS_IN_SECOND));
else
error = EINVAL;
break;
case TCP_BBR_PROBE_RTT_GAIN:
BBR_OPTS_INC(tcp_bbr_probertt_gain);
if (optval <= BBR_UNIT)
bbr->r_ctl.bbr_rttprobe_gain_val = optval;
else
error = EINVAL;
break;
case TCP_BBR_PROBE_RTT_INT:
BBR_OPTS_INC(tcp_bbr_probe_rtt_int);
if (optval > 1000)
bbr->r_ctl.rc_probertt_int = optval;
else
error = EINVAL;
break;
case TCP_BBR_MIN_TOPACEOUT:
BBR_OPTS_INC(tcp_bbr_topaceout);
if (optval == 0) {
bbr->no_pacing_until = 0;
bbr->rc_no_pacing = 0;
} else if (optval <= 0x00ff) {
bbr->no_pacing_until = optval;
if ((bbr->r_ctl.rc_pkt_epoch < bbr->no_pacing_until) &&
(bbr->rc_bbr_state == BBR_STATE_STARTUP)){
/* Turn on no pacing */
bbr->rc_no_pacing = 1;
}
} else
error = EINVAL;
break;
case TCP_BBR_STARTUP_LOSS_EXIT:
BBR_OPTS_INC(tcp_bbr_startup_loss_exit);
bbr->rc_loss_exit = optval;
break;
case TCP_BBR_USEDEL_RATE:
error = EINVAL;
break;
case TCP_BBR_MIN_RTO:
BBR_OPTS_INC(tcp_bbr_min_rto);
bbr->r_ctl.rc_min_rto_ms = optval;
break;
case TCP_BBR_MAX_RTO:
BBR_OPTS_INC(tcp_bbr_max_rto);
bbr->rc_max_rto_sec = optval;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
BBR_OPTS_INC(tcp_rack_min_to);
bbr->r_ctl.rc_min_to = optval;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
BBR_OPTS_INC(tcp_rack_reord_thresh);
if ((optval > 0) && (optval < 31))
bbr->r_ctl.rc_reorder_shift = optval;
else
error = EINVAL;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
BBR_OPTS_INC(tcp_rack_reord_fade);
bbr->r_ctl.rc_reorder_fade = optval;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
BBR_OPTS_INC(tcp_rack_tlp_thresh);
if (optval)
bbr->rc_tlp_threshold = optval;
else
error = EINVAL;
break;
case TCP_BBR_USE_RACK_CHEAT:
BBR_OPTS_INC(tcp_use_rackcheat);
if (bbr->rc_use_google) {
error = EINVAL;
break;
}
BBR_OPTS_INC(tcp_rack_cheat);
if (optval)
bbr->bbr_use_rack_cheat = 1;
else
bbr->bbr_use_rack_cheat = 0;
break;
case TCP_BBR_FLOOR_MIN_TSO:
BBR_OPTS_INC(tcp_utter_max_tso);
if ((optval >= 0) && (optval < 40))
bbr->r_ctl.bbr_hptsi_segments_floor = optval;
else
error = EINVAL;
break;
case TCP_BBR_UTTER_MAX_TSO:
BBR_OPTS_INC(tcp_utter_max_tso);
if ((optval >= 0) && (optval < 0xffff))
bbr->r_ctl.bbr_utter_max = optval;
else
error = EINVAL;
break;
case TCP_BBR_EXTRA_STATE:
BBR_OPTS_INC(tcp_extra_state);
if (optval)
bbr->rc_use_idle_restart = 1;
else
bbr->rc_use_idle_restart = 0;
break;
case TCP_BBR_SEND_IWND_IN_TSO:
BBR_OPTS_INC(tcp_iwnd_tso);
if (optval) {
bbr->bbr_init_win_cheat = 1;
if (bbr->rc_past_init_win == 0) {
uint32_t cts;
cts = tcp_get_usecs(&bbr->rc_tv);
tcp_bbr_tso_size_check(bbr, cts);
}
} else
bbr->bbr_init_win_cheat = 0;
break;
case TCP_BBR_HDWR_PACE:
BBR_OPTS_INC(tcp_hdwr_pacing);
if (optval){
bbr->bbr_hdw_pace_ena = 1;
bbr->bbr_attempt_hdwr_pace = 0;
} else {
bbr->bbr_hdw_pace_ena = 0;
#ifdef RATELIMIT
if (bbr->bbr_hdrw_pacing) {
bbr->bbr_hdrw_pacing = 0;
in_pcbdetach_txrtlmt(bbr->rc_inp);
}
#endif
}
break;
case TCP_DELACK:
BBR_OPTS_INC(tcp_delack);
if (optval < 100) {
if (optval == 0) /* off */
tp->t_delayed_ack = 0;
else if (optval == 1) /* on which is 2 */
tp->t_delayed_ack = 2;
else /* higher than 2 and less than 100 */
tp->t_delayed_ack = optval;
if (tp->t_flags & TF_DELACK) {
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
bbr_output(tp);
}
} else
error = EINVAL;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
BBR_OPTS_INC(tcp_rack_pkt_delay);
bbr->r_ctl.rc_pkt_delay = optval;
break;
#ifdef NETFLIX_PEAKRATE
case TCP_MAXPEAKRATE:
BBR_OPTS_INC(tcp_maxpeak);
error = tcp_set_maxpeakrate(tp, optval);
if (!error)
tp->t_peakrate_thr = tp->t_maxpeakrate;
break;
#endif
case TCP_BBR_RETRAN_WTSO:
BBR_OPTS_INC(tcp_retran_wtso);
if (optval)
bbr->rc_resends_use_tso = 1;
else
bbr->rc_resends_use_tso = 0;
break;
case TCP_DATA_AFTER_CLOSE:
BBR_OPTS_INC(tcp_data_ac);
if (optval)
bbr->rc_allow_data_af_clo = 1;
else
bbr->rc_allow_data_af_clo = 0;
break;
case TCP_BBR_POLICER_DETECT:
BBR_OPTS_INC(tcp_policer_det);
if (bbr->rc_use_google == 0)
error = EINVAL;
else if (optval)
bbr->r_use_policer = 1;
else
bbr->r_use_policer = 0;
break;
case TCP_BBR_TSTMP_RAISES:
BBR_OPTS_INC(tcp_ts_raises);
if (optval)
bbr->ts_can_raise = 1;
else
bbr->ts_can_raise = 0;
break;
case TCP_BBR_TMR_PACE_OH:
BBR_OPTS_INC(tcp_pacing_oh_tmr);
if (bbr->rc_use_google) {
error = EINVAL;
} else {
if (optval)
bbr->r_ctl.rc_incr_tmrs = 1;
else
bbr->r_ctl.rc_incr_tmrs = 0;
}
break;
case TCP_BBR_PACE_OH:
BBR_OPTS_INC(tcp_pacing_oh);
if (bbr->rc_use_google) {
error = EINVAL;
} else {
if (optval > (BBR_INCL_TCP_OH|
BBR_INCL_IP_OH|
BBR_INCL_ENET_OH)) {
error = EINVAL;
break;
}
if (optval & BBR_INCL_TCP_OH)
bbr->r_ctl.rc_inc_tcp_oh = 1;
else
bbr->r_ctl.rc_inc_tcp_oh = 0;
if (optval & BBR_INCL_IP_OH)
bbr->r_ctl.rc_inc_ip_oh = 1;
else
bbr->r_ctl.rc_inc_ip_oh = 0;
if (optval & BBR_INCL_ENET_OH)
bbr->r_ctl.rc_inc_enet_oh = 1;
else
bbr->r_ctl.rc_inc_enet_oh = 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);
}
/*
* return 0 on success, error-num on failure
*/
static int
bbr_get_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_bbr *bbr)
{
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_BBR_PACE_PER_SEC:
optval = bbr->r_ctl.bbr_hptsi_per_second;
break;
case TCP_BBR_PACE_DEL_TAR:
optval = bbr->r_ctl.bbr_hptsi_segments_delay_tar;
break;
case TCP_BBR_PACE_SEG_MAX:
optval = bbr->r_ctl.bbr_hptsi_segments_max;
break;
case TCP_BBR_MIN_TOPACEOUT:
optval = bbr->no_pacing_until;
break;
case TCP_BBR_PACE_SEG_MIN:
optval = bbr->r_ctl.bbr_hptsi_bytes_min;
break;
case TCP_BBR_PACE_CROSS:
optval = bbr->r_ctl.bbr_cross_over;
break;
case TCP_BBR_ALGORITHM:
optval = bbr->rc_use_google;
break;
case TCP_BBR_TSLIMITS:
optval = bbr->rc_use_ts_limit;
break;
case TCP_BBR_IWINTSO:
optval = bbr->rc_init_win;
break;
case TCP_BBR_STARTUP_PG:
optval = bbr->r_ctl.rc_startup_pg;
break;
case TCP_BBR_DRAIN_PG:
optval = bbr->r_ctl.rc_drain_pg;
break;
case TCP_BBR_PROBE_RTT_INT:
optval = bbr->r_ctl.rc_probertt_int;
break;
case TCP_BBR_PROBE_RTT_LEN:
optval = (bbr->r_ctl.rc_rttprop.cur_time_limit / USECS_IN_SECOND);
break;
case TCP_BBR_PROBE_RTT_GAIN:
optval = bbr->r_ctl.bbr_rttprobe_gain_val;
break;
case TCP_BBR_STARTUP_LOSS_EXIT:
optval = bbr->rc_loss_exit;
break;
case TCP_BBR_USEDEL_RATE:
error = EINVAL;
break;
case TCP_BBR_MIN_RTO:
optval = bbr->r_ctl.rc_min_rto_ms;
break;
case TCP_BBR_MAX_RTO:
optval = bbr->rc_max_rto_sec;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments in a pace */
optval = bbr->r_ctl.rc_pace_max_segs;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
optval = bbr->r_ctl.rc_min_to;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
optval = bbr->r_ctl.rc_reorder_shift;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
optval = bbr->r_ctl.rc_reorder_fade;
break;
case TCP_BBR_USE_RACK_CHEAT:
/* Do we use the rack cheat for rxt */
optval = bbr->bbr_use_rack_cheat;
break;
case TCP_BBR_FLOOR_MIN_TSO:
optval = bbr->r_ctl.bbr_hptsi_segments_floor;
break;
case TCP_BBR_UTTER_MAX_TSO:
optval = bbr->r_ctl.bbr_utter_max;
break;
case TCP_BBR_SEND_IWND_IN_TSO:
/* Do we send TSO size segments initially */
optval = bbr->bbr_init_win_cheat;
break;
case TCP_BBR_EXTRA_STATE:
optval = bbr->rc_use_idle_restart;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
optval = bbr->rc_tlp_threshold;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
optval = bbr->r_ctl.rc_pkt_delay;
break;
case TCP_BBR_RETRAN_WTSO:
optval = bbr->rc_resends_use_tso;
break;
case TCP_DATA_AFTER_CLOSE:
optval = bbr->rc_allow_data_af_clo;
break;
case TCP_DELACK:
optval = tp->t_delayed_ack;
break;
case TCP_BBR_HDWR_PACE:
optval = bbr->bbr_hdw_pace_ena;
break;
case TCP_BBR_POLICER_DETECT:
optval = bbr->r_use_policer;
break;
case TCP_BBR_TSTMP_RAISES:
optval = bbr->ts_can_raise;
break;
case TCP_BBR_TMR_PACE_OH:
optval = bbr->r_ctl.rc_incr_tmrs;
break;
case TCP_BBR_PACE_OH:
optval = 0;
if (bbr->r_ctl.rc_inc_tcp_oh)
optval |= BBR_INCL_TCP_OH;
if (bbr->r_ctl.rc_inc_ip_oh)
optval |= BBR_INCL_IP_OH;
if (bbr->r_ctl.rc_inc_enet_oh)
optval |= BBR_INCL_ENET_OH;
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
return (error);
}
/*
* return 0 on success, error-num on failure
*/
static int
bbr_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
{
int32_t error = EINVAL;
struct tcp_bbr *bbr;
bbr = (struct tcp_bbr *)tp->t_fb_ptr;
if (bbr == NULL) {
/* Huh? */
goto out;
}
if (sopt->sopt_dir == SOPT_SET) {
return (bbr_set_sockopt(so, sopt, inp, tp, bbr));
} else if (sopt->sopt_dir == SOPT_GET) {
return (bbr_get_sockopt(so, sopt, inp, tp, bbr));
}
out:
INP_WUNLOCK(inp);
return (error);
}
struct tcp_function_block __tcp_bbr = {
.tfb_tcp_block_name = __XSTRING(STACKNAME),
.tfb_tcp_output = bbr_output,
.tfb_do_queued_segments = ctf_do_queued_segments,
.tfb_do_segment_nounlock = bbr_do_segment_nounlock,
.tfb_tcp_do_segment = bbr_do_segment,
.tfb_tcp_ctloutput = bbr_ctloutput,
.tfb_tcp_fb_init = bbr_init,
.tfb_tcp_fb_fini = bbr_fini,
.tfb_tcp_timer_stop_all = bbr_stopall,
.tfb_tcp_timer_activate = bbr_timer_activate,
.tfb_tcp_timer_active = bbr_timer_active,
.tfb_tcp_timer_stop = bbr_timer_stop,
.tfb_tcp_rexmit_tmr = bbr_remxt_tmr,
.tfb_tcp_handoff_ok = bbr_handoff_ok,
.tfb_tcp_mtu_chg = bbr_mtu_chg
};
static const char *bbr_stack_names[] = {
__XSTRING(STACKNAME),
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#endif
};
static bool bbr_mod_inited = false;
static int
tcp_addbbr(module_t mod, int32_t type, void *data)
{
int32_t err = 0;
int num_stacks;
switch (type) {
case MOD_LOAD:
printf("Attempting to load " __XSTRING(MODNAME) "\n");
bbr_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
sizeof(struct bbr_sendmap),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
bbr_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
sizeof(struct tcp_bbr),
NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
sysctl_ctx_init(&bbr_sysctl_ctx);
bbr_sysctl_root = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
OID_AUTO,
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#else
__XSTRING(STACKNAME),
#endif
CTLFLAG_RW, 0,
"");
if (bbr_sysctl_root == NULL) {
printf("Failed to add sysctl node\n");
err = EFAULT;
goto free_uma;
}
bbr_init_sysctls();
num_stacks = nitems(bbr_stack_names);
err = register_tcp_functions_as_names(&__tcp_bbr, M_WAITOK,
bbr_stack_names, &num_stacks);
if (err) {
printf("Failed to register %s stack name for "
"%s module\n", bbr_stack_names[num_stacks],
__XSTRING(MODNAME));
sysctl_ctx_free(&bbr_sysctl_ctx);
free_uma:
uma_zdestroy(bbr_zone);
uma_zdestroy(bbr_pcb_zone);
bbr_counter_destroy();
printf("Failed to register " __XSTRING(MODNAME)
" module err:%d\n", err);
return (err);
}
tcp_lro_reg_mbufq();
bbr_mod_inited = true;
printf(__XSTRING(MODNAME) " is now available\n");
break;
case MOD_QUIESCE:
err = deregister_tcp_functions(&__tcp_bbr, true, false);
break;
case MOD_UNLOAD:
err = deregister_tcp_functions(&__tcp_bbr, false, true);
if (err == EBUSY)
break;
if (bbr_mod_inited) {
uma_zdestroy(bbr_zone);
uma_zdestroy(bbr_pcb_zone);
sysctl_ctx_free(&bbr_sysctl_ctx);
bbr_counter_destroy();
printf(__XSTRING(MODNAME)
" is now no longer available\n");
bbr_mod_inited = false;
}
tcp_lro_dereg_mbufq();
err = 0;
break;
default:
return (EOPNOTSUPP);
}
return (err);
}
static moduledata_t tcp_bbr = {
.name = __XSTRING(MODNAME),
.evhand = tcp_addbbr,
.priv = 0
};
MODULE_VERSION(MODNAME, 1);
DECLARE_MODULE(MODNAME, tcp_bbr, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
Reference in New Issue View Git Blame Copy Permalink