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Index: sys/kern/uipc_sockbuf.c
===================================================================
--- sys/kern/uipc_sockbuf.c
+++ sys/kern/uipc_sockbuf.c
@@ -1283,6 +1283,55 @@
return (ret);
}
+struct mbuf *
+sbsndptr_noadv(struct sockbuf *sb, uint32_t off, uint32_t *moff)
+{
+ struct mbuf *m;
+
+ KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__));
+ if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) {
+ *moff = off;
+ if (sb->sb_sndptr == NULL) {
+ sb->sb_sndptr = sb->sb_mb;
+ sb->sb_sndptroff = 0;
+ }
+ return (sb->sb_mb);
+ } else {
+ m = sb->sb_sndptr;
+ off -= sb->sb_sndptroff;
+ }
+ *moff = off;
+ return (m);
+}
+
+void
+sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, uint32_t len)
+{
+ /*
+ * A small copy was done, advance forward the sb_sbsndptr to cover
+ * it.
+ */
+ struct mbuf *m;
+
+ if (mb != sb->sb_sndptr) {
+ /* Did not copyout at the same mbuf */
+ return;
+ }
+ m = mb;
+ while (m && (len > 0)) {
+ if (len >= m->m_len) {
+ len -= m->m_len;
+ if (m->m_next) {
+ sb->sb_sndptroff += m->m_len;
+ sb->sb_sndptr = m->m_next;
+ }
+ m = m->m_next;
+ } else {
+ len = 0;
+ }
+ }
+}
+
/*
* Return the first mbuf and the mbuf data offset for the provided
* send offset without changing the "sb_sndptroff" field.
Index: sys/modules/tcp/Makefile
===================================================================
--- sys/modules/tcp/Makefile
+++ sys/modules/tcp/Makefile
@@ -7,10 +7,12 @@
SUBDIR= \
${_tcp_fastpath} \
+ ${_tcp_rack} \
${_tcpmd5} \
.if ${MK_EXTRA_TCP_STACKS} != "no" || defined(ALL_MODULES)
_tcp_fastpath= fastpath
+_tcp_rack= rack
.endif
.if (${MK_INET_SUPPORT} != "no" || ${MK_INET6_SUPPORT} != "no") || \
Index: sys/modules/tcp/rack/Makefile
===================================================================
--- sys/modules/tcp/rack/Makefile
+++ sys/modules/tcp/rack/Makefile
@@ -0,0 +1,24 @@
+#
+# $FreeBSD$
+#
+
+.PATH: ${.CURDIR}/../../../netinet/tcp_stacks
+
+STACKNAME= rack
+KMOD= tcp_${STACKNAME}
+SRCS= rack.c sack_filter.c
+
+SRCS+= opt_inet.h opt_inet6.h opt_ipsec.h
+SRCS+= opt_tcpdebug.h
+SRCS+= opt_kern_tls.h
+
+#
+# Enable full debugging
+#
+#CFLAGS += -g
+
+CFLAGS+= -DMODNAME=${KMOD}
+CFLAGS+= -DSTACKNAME=${STACKNAME}
+CFLAGS+= -DSTACKALIAS=rack_18q21
+
+.include <bsd.kmod.mk>
Index: sys/netinet/tcp.h
===================================================================
--- sys/netinet/tcp.h
+++ sys/netinet/tcp.h
@@ -176,6 +176,7 @@
device */
#define TCP_CONGESTION 64 /* get/set congestion control algorithm */
#define TCP_CCALGOOPT 65 /* get/set cc algorithm specific options */
+#define TCP_DELACK 72 /* socket option for delayed ack */
#define TCP_KEEPINIT 128 /* N, time to establish connection */
#define TCP_KEEPIDLE 256 /* L,N,X start keeplives after this period */
#define TCP_KEEPINTVL 512 /* L,N interval between keepalives */
@@ -184,6 +185,61 @@
#define TCP_PCAP_OUT 2048 /* number of output packets to keep */
#define TCP_PCAP_IN 4096 /* number of input packets to keep */
#define TCP_FUNCTION_BLK 8192 /* Set the tcp function pointers to the specified stack */
+/* Options for Rack and BBR */
+#define TCP_RACK_PROP 1051 /* RACK proportional rate reduction (bool) */
+#define TCP_RACK_TLP_REDUCE 1052 /* RACK TLP cwnd reduction (bool) */
+#define TCP_RACK_PACE_REDUCE 1053 /* RACK Pacing reduction factor (divisor) */
+#define TCP_RACK_PACE_MAX_SEG 1054 /* Max segments in a pace */
+#define TCP_RACK_PACE_ALWAYS 1055 /* Use the always pace method */
+#define TCP_RACK_PROP_RATE 1056 /* The proportional reduction rate */
+#define TCP_RACK_PRR_SENDALOT 1057 /* Allow PRR to send more than one seg */
+#define TCP_RACK_MIN_TO 1058 /* Minimum time between rack t-o's in ms */
+#define TCP_RACK_EARLY_RECOV 1059 /* Should recovery happen early (bool) */
+#define TCP_RACK_EARLY_SEG 1060 /* If early recovery max segments */
+#define TCP_RACK_REORD_THRESH 1061 /* RACK reorder threshold (shift amount) */
+#define TCP_RACK_REORD_FADE 1062 /* Does reordering fade after ms time */
+#define TCP_RACK_TLP_THRESH 1063 /* RACK TLP theshold i.e. srtt+(srtt/N) */
+#define TCP_RACK_PKT_DELAY 1064 /* RACK added ms i.e. rack-rtt + reord + N */
+#define TCP_RACK_TLP_INC_VAR 1065 /* Does TLP include rtt variance in t-o */
+#define TCP_RACK_SESS_CWV 1066 /* Enable RFC7611 cwnd validation on sess */
+#define TCP_BBR_IWINTSO 1067 /* Initial TSO window for BBRs first sends */
+#define TCP_BBR_RECFORCE 1068 /* Enter recovery force out a segment disregard pacer */
+#define TCP_BBR_STARTUP_PG 1069 /* Startup pacing gain */
+#define TCP_BBR_DRAIN_PG 1070 /* Drain pacing gain */
+#define TCP_BBR_RWND_IS_APP 1071 /* Rwnd limited is considered app limited */
+#define TCP_BBR_PROBE_RTT_INT 1072 /* How long in useconds between probe-rtt */
+#define TCP_BBR_ONE_RETRAN 1073 /* Is only one segment allowed out during retran */
+#define TCP_BBR_STARTUP_LOSS_EXIT 1074 /* Do we exit a loss during startup if not 20% incr */
+#define TCP_BBR_USE_LOWGAIN 1075 /* lower the gain in PROBE_BW enable */
+#define TCP_BBR_LOWGAIN_THRESH 1076 /* How many cycles do we stay in lowgain */
+#define TCP_BBR_LOWGAIN_HALF 1077 /* Do we halfstep lowgain down */
+#define TCP_BBR_LOWGAIN_FD 1078 /* Do we force a drain when lowgain in place */
+#define TCP_BBR_USEDEL_RATE 1079 /* Enable use of delivery rate for loss recovery */
+#define TCP_BBR_MIN_RTO 1080 /* Min RTO in milliseconds */
+#define TCP_BBR_MAX_RTO 1081 /* Max RTO in milliseconds */
+#define TCP_BBR_REC_OVER_HPTS 1082 /* Recovery override htps settings 0/1/3 */
+#define TCP_BBR_UNLIMITED 1083 /* Does BBR, in non-recovery not use cwnd */
+#define TCP_BBR_DRAIN_INC_EXTRA 1084 /* Does the 3/4 drain target include the extra gain */
+#define TCP_BBR_STARTUP_EXIT_EPOCH 1085 /* what epoch gets us out of startup */
+#define TCP_BBR_PACE_PER_SEC 1086
+#define TCP_BBR_PACE_DEL_TAR 1087
+#define TCP_BBR_PACE_SEG_MAX 1088
+#define TCP_BBR_PACE_SEG_MIN 1089
+#define TCP_BBR_PACE_CROSS 1090
+#define TCP_RACK_IDLE_REDUCE_HIGH 1092 /* Reduce the highest cwnd seen to IW on idle */
+#define TCP_RACK_IDLE_REDUCE_HIGH 1092 /* Reduce the highest cwnd seen to IW on idle */
+#define TCP_RACK_MIN_PACE 1093 /* Do we enforce rack min pace time */
+#define TCP_RACK_MIN_PACE_SEG 1094 /* If so what is the seg threshould */
+#define TCP_RACK_TLP_USE 1095
+#define TCP_BBR_ACK_COMP_ALG 1096 /* Not used */
+#define TCP_BBR_EXTRA_GAIN 1097
+#define TCP_BBR_RACK_RTT_USE 1098 /* what RTT should we use 0, 1, or 2? */
+#define TCP_BBR_RETRAN_WTSO 1099
+#define TCP_DATA_AFTER_CLOSE 1100
+#define TCP_BBR_PROBE_RTT_GAIN 1101
+#define TCP_BBR_PROBE_RTT_LEN 1102
+
+
/* Start of reserved space for third-party user-settable options. */
#define TCP_VENDOR SO_VENDOR
Index: sys/netinet/tcp_log_buf.h
===================================================================
--- sys/netinet/tcp_log_buf.h
+++ sys/netinet/tcp_log_buf.h
@@ -94,7 +94,7 @@
uint16_t flex7;
uint8_t bbr_state;
uint8_t bbr_substate;
- uint8_t inpacer;
+ uint8_t inhpts;
uint8_t ininput;
uint8_t use_lt_bw;
uint8_t flex8;
Index: sys/netinet/tcp_output.c
===================================================================
--- sys/netinet/tcp_output.c
+++ sys/netinet/tcp_output.c
@@ -143,11 +143,6 @@
tcp_timer_active((tp), TT_PERSIST), \
("neither rexmt nor persist timer is set"))
-#ifdef TCP_HHOOK
-static void inline hhook_run_tcp_est_out(struct tcpcb *tp,
- struct tcphdr *th, struct tcpopt *to,
- uint32_t len, int tso);
-#endif
static void inline cc_after_idle(struct tcpcb *tp);
#ifdef TCP_HHOOK
@@ -154,7 +149,7 @@
/*
* Wrapper for the TCP established output helper hook.
*/
-static void inline
+void
hhook_run_tcp_est_out(struct tcpcb *tp, struct tcphdr *th,
struct tcpopt *to, uint32_t len, int tso)
{
@@ -1851,6 +1846,144 @@
return (optlen);
}
+/*
+ * This is a copy of m_copym(), taking the TSO segment size/limit
+ * constraints into account, and advancing the sndptr as it goes.
+ */
+struct mbuf *
+tcp_m_copym(struct mbuf *m, int32_t off0, int32_t *plen,
+ int32_t seglimit, int32_t segsize, struct sockbuf *sb)
+{
+ struct mbuf *n, **np;
+ struct mbuf *top;
+ int32_t off = off0;
+ int32_t len = *plen;
+ int32_t fragsize;
+ int32_t len_cp = 0;
+ int32_t *pkthdrlen;
+ uint32_t mlen, frags;
+ bool copyhdr;
+
+
+ KASSERT(off >= 0, ("tcp_m_copym, negative off %d", off));
+ KASSERT(len >= 0, ("tcp_m_copym, negative len %d", len));
+ if (off == 0 && m->m_flags & M_PKTHDR)
+ copyhdr = true;
+ else
+ copyhdr = false;
+ while (off > 0) {
+ KASSERT(m != NULL, ("tcp_m_copym, offset > size of mbuf chain"));
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ if ((sb) && (m == sb->sb_sndptr)) {
+ sb->sb_sndptroff += m->m_len;
+ sb->sb_sndptr = m->m_next;
+ }
+ m = m->m_next;
+ }
+ np = &top;
+ top = NULL;
+ pkthdrlen = NULL;
+ while (len > 0) {
+ if (m == NULL) {
+ KASSERT(len == M_COPYALL,
+ ("tcp_m_copym, length > size of mbuf chain"));
+ *plen = len_cp;
+ if (pkthdrlen != NULL)
+ *pkthdrlen = len_cp;
+ break;
+ }
+ mlen = min(len, m->m_len - off);
+ if (seglimit) {
+ /*
+ * For M_NOMAP mbufs, add 3 segments
+ * + 1 in case we are crossing page boundaries
+ * + 2 in case the TLS hdr/trailer are used
+ * It is cheaper to just add the segments
+ * than it is to take the cache miss to look
+ * at the mbuf ext_pgs state in detail.
+ */
+ if (m->m_flags & M_NOMAP) {
+ fragsize = min(segsize, PAGE_SIZE);
+ frags = 3;
+ } else {
+ fragsize = segsize;
+ frags = 0;
+ }
+
+ /* Break if we really can't fit anymore. */
+ if ((frags + 1) >= seglimit) {
+ *plen = len_cp;
+ if (pkthdrlen != NULL)
+ *pkthdrlen = len_cp;
+ break;
+ }
+
+ /*
+ * Reduce size if you can't copy the whole
+ * mbuf. If we can't copy the whole mbuf, also
+ * adjust len so the loop will end after this
+ * mbuf.
+ */
+ if ((frags + howmany(mlen, fragsize)) >= seglimit) {
+ mlen = (seglimit - frags - 1) * fragsize;
+ len = mlen;
+ *plen = len_cp + len;
+ if (pkthdrlen != NULL)
+ *pkthdrlen = *plen;
+ }
+ frags += howmany(mlen, fragsize);
+ if (frags == 0)
+ frags++;
+ seglimit -= frags;
+ KASSERT(seglimit > 0,
+ ("%s: seglimit went too low", __func__));
+ }
+ if (copyhdr)
+ n = m_gethdr(M_NOWAIT, m->m_type);
+ else
+ n = m_get(M_NOWAIT, m->m_type);
+ *np = n;
+ if (n == NULL)
+ goto nospace;
+ if (copyhdr) {
+ if (!m_dup_pkthdr(n, m, M_NOWAIT))
+ goto nospace;
+ if (len == M_COPYALL)
+ n->m_pkthdr.len -= off0;
+ else
+ n->m_pkthdr.len = len;
+ pkthdrlen = &n->m_pkthdr.len;
+ copyhdr = false;
+ }
+ n->m_len = mlen;
+ len_cp += n->m_len;
+ if (m->m_flags & M_EXT) {
+ n->m_data = m->m_data + off;
+ mb_dupcl(n, m);
+ } else
+ bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
+ (u_int)n->m_len);
+
+ if (sb && (sb->sb_sndptr == m) &&
+ ((n->m_len + off) >= m->m_len) && m->m_next) {
+ sb->sb_sndptroff += m->m_len;
+ sb->sb_sndptr = m->m_next;
+ }
+ off = 0;
+ if (len != M_COPYALL) {
+ len -= n->m_len;
+ }
+ m = m->m_next;
+ np = &n->m_next;
+ }
+ return (top);
+nospace:
+ m_freem(top);
+ return (NULL);
+}
+
void
tcp_sndbuf_autoscale(struct tcpcb *tp, struct socket *so, uint32_t sendwin)
{
Index: sys/netinet/tcp_stacks/fastpath.c
===================================================================
--- sys/netinet/tcp_stacks/fastpath.c
+++ sys/netinet/tcp_stacks/fastpath.c
@@ -2392,7 +2392,7 @@
static int
tcp_addfastpaths(module_t mod, int type, void *data)
{
- int err=0;
+ int err = 0;
switch (type) {
case MOD_LOAD:
Index: sys/netinet/tcp_stacks/rack.c
===================================================================
--- sys/netinet/tcp_stacks/rack.c
+++ sys/netinet/tcp_stacks/rack.c
@@ -0,0 +1,9162 @@
+/*-
+ * Copyright (c) 2016-2018
+ * 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.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_inet.h"
+#include "opt_inet6.h"
+#include "opt_ipsec.h"
+#include "opt_tcpdebug.h"
+
+#include <sys/param.h>
+#include <sys/module.h>
+#include <sys/kernel.h>
+#ifdef TCP_HHOOK
+#include <sys/hhook.h>
+#endif
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/mbuf.h>
+#include <sys/proc.h> /* for proc0 declaration */
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+#ifdef NETFLIX_STATS
+#include <sys/stats.h>
+#endif
+#include <sys/refcount.h>
+#include <sys/queue.h>
+#include <sys/smp.h>
+#include <sys/kthread.h>
+#include <sys/kern_prefetch.h>
+
+#include <vm/uma.h>
+
+#include <net/route.h>
+#include <net/vnet.h>
+
+#define TCPSTATES /* for logging */
+
+#include <netinet/in.h>
+#include <netinet/in_kdtrace.h>
+#include <netinet/in_pcb.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h> /* required for icmp_var.h */
+#include <netinet/icmp_var.h> /* for ICMP_BANDLIM */
+#include <netinet/ip_var.h>
+#include <netinet/ip6.h>
+#include <netinet6/in6_pcb.h>
+#include <netinet6/ip6_var.h>
+#define TCPOUTFLAGS
+#include <netinet/tcp.h>
+#include <netinet/tcp_fsm.h>
+#include <netinet/tcp_log_buf.h>
+#include <netinet/tcp_seq.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
+#include <netinet/tcp_hpts.h>
+#include <netinet/tcpip.h>
+#include <netinet/cc/cc.h>
+#ifdef NETFLIX_CWV
+#include <netinet/tcp_newcwv.h>
+#endif
+#include <netinet/tcp_fastopen.h>
+#ifdef TCPDEBUG
+#include <netinet/tcp_debug.h>
+#endif /* TCPDEBUG */
+#ifdef TCP_OFFLOAD
+#include <netinet/tcp_offload.h>
+#endif
+#ifdef INET6
+#include <netinet6/tcp6_var.h>
+#endif
+
+#include <netipsec/ipsec_support.h>
+
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+#include <netipsec/ipsec.h>
+#include <netipsec/ipsec6.h>
+#endif /* IPSEC */
+
+#include <netinet/udp.h>
+#include <netinet/udp_var.h>
+#include <machine/in_cksum.h>
+
+#ifdef MAC
+#include <security/mac/mac_framework.h>
+#endif
+#include "sack_filter.h"
+#include "tcp_rack.h"
+#include "rack_bbr_common.h"
+
+uma_zone_t rack_zone;
+uma_zone_t rack_pcb_zone;
+
+#ifndef TICKS2SBT
+#define TICKS2SBT(__t) (tick_sbt * ((sbintime_t)(__t)))
+#endif
+
+struct sysctl_ctx_list rack_sysctl_ctx;
+struct sysctl_oid *rack_sysctl_root;
+
+#ifndef TCPHPTS
+fatal error missing option TCPHSTS in the build;
+#endif
+
+#define CUM_ACKED 1
+#define SACKED 2
+
+/*
+ * The RACK module incorporates a number of
+ * TCP ideas that have been put out into the IETF
+ * over the last few years:
+ * - Matt Mathis's Rate Halving which slowly drops
+ * the congestion window so that the ack clock can
+ * be maintained during a recovery.
+ * - Yuchung Cheng's RACK TCP (for which its named) that
+ * will stop us using the number of dup acks and instead
+ * use time as the gage of when we retransmit.
+ * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
+ * of Dukkipati et.al.
+ * RACK depends on SACK, so if an endpoint arrives that
+ * cannot do SACK the state machine below will shuttle the
+ * connection back to using the "default" TCP stack that is
+ * in FreeBSD.
+ *
+ * To implement RACK the original TCP stack was first decomposed
+ * into a functional state machine with individual states
+ * for each of the possible TCP connection states. The do_segement
+ * functions role in life is to mandate the connection supports SACK
+ * initially and then assure that the RACK state matches the conenction
+ * state before calling the states do_segment function. Each
+ * state is simplified due to the fact that the original do_segment
+ * has been decomposed and we *know* what state we are in (no
+ * switches on the state) and all tests for SACK are gone. This
+ * greatly simplifies what each state does.
+ *
+ * TCP output is also over-written with a new version since it
+ * must maintain the new rack scoreboard.
+ *
+ */
+static int32_t rack_precache = 1;
+static int32_t rack_tlp_thresh = 1;
+static int32_t rack_reorder_thresh = 2;
+static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000
+ * - 60 seconds */
+static int32_t rack_pkt_delay = 1;
+static int32_t rack_inc_var = 0;/* For TLP */
+static int32_t rack_reduce_largest_on_idle = 0;
+static int32_t rack_min_pace_time = 0;
+static int32_t rack_min_pace_time_seg_req=6;
+static int32_t rack_early_recovery = 1;
+static int32_t rack_early_recovery_max_seg = 6;
+static int32_t rack_send_a_lot_in_prr = 1;
+static int32_t rack_min_to = 1; /* Number of ms minimum timeout */
+static int32_t rack_tlp_in_recovery = 1; /* Can we do TLP in recovery? */
+static int32_t rack_verbose_logging = 0;
+static int32_t rack_ignore_data_after_close = 1;
+/*
+ * Currently regular tcp has a rto_min of 30ms
+ * the backoff goes 12 times so that ends up
+ * being a total of 122.850 seconds before a
+ * connection is killed.
+ */
+static int32_t rack_tlp_min = 10;
+static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */
+static int32_t rack_rto_max = 30000; /* 30 seconds */
+static const int32_t rack_free_cache = 2;
+static int32_t rack_hptsi_segments = 40;
+static int32_t rack_rate_sample_method = USE_RTT_LOW;
+static int32_t rack_pace_every_seg = 1;
+static int32_t rack_delayed_ack_time = 200; /* 200ms */
+static int32_t rack_slot_reduction = 4;
+static int32_t rack_lower_cwnd_at_tlp = 0;
+static int32_t rack_use_proportional_reduce = 0;
+static int32_t rack_proportional_rate = 10;
+static int32_t rack_tlp_max_resend = 2;
+static int32_t rack_limited_retran = 0;
+static int32_t rack_always_send_oldest = 0;
+static int32_t rack_sack_block_limit = 128;
+static int32_t rack_use_sack_filter = 1;
+static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
+
+/* Rack specific counters */
+counter_u64_t rack_badfr;
+counter_u64_t rack_badfr_bytes;
+counter_u64_t rack_rtm_prr_retran;
+counter_u64_t rack_rtm_prr_newdata;
+counter_u64_t rack_timestamp_mismatch;
+counter_u64_t rack_reorder_seen;
+counter_u64_t rack_paced_segments;
+counter_u64_t rack_unpaced_segments;
+counter_u64_t rack_saw_enobuf;
+counter_u64_t rack_saw_enetunreach;
+
+/* Tail loss probe counters */
+counter_u64_t rack_tlp_tot;
+counter_u64_t rack_tlp_newdata;
+counter_u64_t rack_tlp_retran;
+counter_u64_t rack_tlp_retran_bytes;
+counter_u64_t rack_tlp_retran_fail;
+counter_u64_t rack_to_tot;
+counter_u64_t rack_to_arm_rack;
+counter_u64_t rack_to_arm_tlp;
+counter_u64_t rack_to_alloc;
+counter_u64_t rack_to_alloc_hard;
+counter_u64_t rack_to_alloc_emerg;
+
+counter_u64_t rack_sack_proc_all;
+counter_u64_t rack_sack_proc_short;
+counter_u64_t rack_sack_proc_restart;
+counter_u64_t rack_runt_sacks;
+counter_u64_t rack_used_tlpmethod;
+counter_u64_t rack_used_tlpmethod2;
+counter_u64_t rack_enter_tlp_calc;
+counter_u64_t rack_input_idle_reduces;
+counter_u64_t rack_tlp_does_nada;
+
+/* Temp CPU counters */
+counter_u64_t rack_find_high;
+
+counter_u64_t rack_progress_drops;
+counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
+counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
+
+static void
+rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line);
+
+static int
+rack_process_ack(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t * ti_locked,
+ uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
+static int
+rack_process_data(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static void
+rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
+ struct tcphdr *th, uint16_t nsegs, uint16_t type, int32_t recovery);
+static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
+static struct rack_sendmap *
+rack_check_recovery_mode(struct tcpcb *tp,
+ uint32_t tsused);
+static void
+rack_cong_signal(struct tcpcb *tp, struct tcphdr *th,
+ uint32_t type);
+static void rack_counter_destroy(void);
+static int
+rack_ctloutput(struct socket *so, struct sockopt *sopt,
+ struct inpcb *inp, struct tcpcb *tp);
+static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
+static void
+rack_do_segment(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
+ uint8_t iptos, int32_t ti_locked);
+static void rack_dtor(void *mem, int32_t size, void *arg);
+static void
+rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
+ uint32_t t, uint32_t cts);
+static struct rack_sendmap *
+rack_find_high_nonack(struct tcp_rack *rack,
+ struct rack_sendmap *rsm);
+static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
+static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
+static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
+static int
+rack_get_sockopt(struct socket *so, struct sockopt *sopt,
+ struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
+static int32_t rack_handoff_ok(struct tcpcb *tp);
+static int32_t rack_init(struct tcpcb *tp);
+static void rack_init_sysctls(void);
+static void
+rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
+ struct tcphdr *th);
+static void
+rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
+ uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
+ uint8_t pass, struct rack_sendmap *hintrsm);
+static void
+rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm);
+static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num);
+static int32_t rack_output(struct tcpcb *tp);
+static void
+rack_hpts_do_segment(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
+ uint8_t iptos, int32_t ti_locked, int32_t nxt_pkt, struct timeval *tv);
+
+static uint32_t
+rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
+ struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
+ uint32_t cts);
+static void rack_post_recovery(struct tcpcb *tp, struct tcphdr *th);
+static void rack_remxt_tmr(struct tcpcb *tp);
+static int
+rack_set_sockopt(struct socket *so, struct sockopt *sopt,
+ struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
+static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
+static int32_t rack_stopall(struct tcpcb *tp);
+static void
+rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
+ uint32_t delta);
+static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
+static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
+static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
+static uint32_t
+rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp);
+static void
+rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, uint32_t ts);
+static int
+rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type);
+static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
+static void
+rack_challenge_ack(struct mbuf *m, struct tcphdr *th,
+ struct tcpcb *tp, int32_t * ti_locked, int32_t * ret_val);
+static int
+rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_closing(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static void rack_do_drop(struct mbuf *m, struct tcpcb *tp, int32_t * ti_locked);
+static void
+rack_do_dropafterack(struct mbuf *m, struct tcpcb *tp,
+ struct tcphdr *th, int32_t * ti_locked, int32_t thflags, int32_t tlen, int32_t * ret_val);
+static void
+rack_do_dropwithreset(struct mbuf *m, struct tcpcb *tp,
+ struct tcphdr *th, int32_t * ti_locked, int32_t rstreason, int32_t tlen);
+static int
+rack_do_established(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t nxt_pkt);
+static int
+rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_lastack(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
+ int32_t tlen, int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
+static int
+rack_drop_checks(struct tcpopt *to, struct mbuf *m,
+ struct tcphdr *th, struct tcpcb *tp, int32_t * tlenp, int32_t * ti_locked, int32_t * thf,
+ int32_t * drop_hdrlen, int32_t * ret_val);
+static int
+rack_process_rst(struct mbuf *m, struct tcphdr *th,
+ struct socket *so, struct tcpcb *tp, int32_t * ti_locked);
+struct rack_sendmap *
+tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
+ uint32_t tsused);
+static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt);
+static void
+ tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th);
+
+static int
+rack_ts_check(struct mbuf *m, struct tcphdr *th,
+ struct tcpcb *tp, int32_t * ti_locked, int32_t tlen, int32_t thflags, int32_t * ret_val);
+
+int32_t rack_clear_counter=0;
+
+
+static int
+sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
+{
+ uint32_t stat;
+ int32_t error;
+
+ error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
+ if (error || req->newptr == NULL)
+ return error;
+
+ error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
+ if (error)
+ return (error);
+ if (stat == 1) {
+#ifdef INVARIANTS
+ printf("Clearing RACK counters\n");
+#endif
+ counter_u64_zero(rack_badfr);
+ counter_u64_zero(rack_badfr_bytes);
+ counter_u64_zero(rack_rtm_prr_retran);
+ counter_u64_zero(rack_rtm_prr_newdata);
+ counter_u64_zero(rack_timestamp_mismatch);
+ counter_u64_zero(rack_reorder_seen);
+ counter_u64_zero(rack_tlp_tot);
+ counter_u64_zero(rack_tlp_newdata);
+ counter_u64_zero(rack_tlp_retran);
+ counter_u64_zero(rack_tlp_retran_bytes);
+ counter_u64_zero(rack_tlp_retran_fail);
+ counter_u64_zero(rack_to_tot);
+ counter_u64_zero(rack_to_arm_rack);
+ counter_u64_zero(rack_to_arm_tlp);
+ counter_u64_zero(rack_paced_segments);
+ counter_u64_zero(rack_unpaced_segments);
+ counter_u64_zero(rack_saw_enobuf);
+ counter_u64_zero(rack_saw_enetunreach);
+ counter_u64_zero(rack_to_alloc_hard);
+ counter_u64_zero(rack_to_alloc_emerg);
+ counter_u64_zero(rack_sack_proc_all);
+ counter_u64_zero(rack_sack_proc_short);
+ counter_u64_zero(rack_sack_proc_restart);
+ counter_u64_zero(rack_to_alloc);
+ counter_u64_zero(rack_find_high);
+ counter_u64_zero(rack_runt_sacks);
+ counter_u64_zero(rack_used_tlpmethod);
+ counter_u64_zero(rack_used_tlpmethod2);
+ counter_u64_zero(rack_enter_tlp_calc);
+ counter_u64_zero(rack_progress_drops);
+ counter_u64_zero(rack_tlp_does_nada);
+ }
+ rack_clear_counter = 0;
+ return (0);
+}
+
+
+
+static void
+rack_init_sysctls()
+{
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "rate_sample_method", CTLFLAG_RW,
+ &rack_rate_sample_method , USE_RTT_LOW,
+ "What method should we use for rate sampling 0=high, 1=low ");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "data_after_close", CTLFLAG_RW,
+ &rack_ignore_data_after_close, 0,
+ "Do we hold off sending a RST until all pending data is ack'd");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlpmethod", CTLFLAG_RW,
+ &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
+ "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "min_pace_time", CTLFLAG_RW,
+ &rack_min_pace_time, 0,
+ "Should we enforce a minimum pace time of 1ms");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "min_pace_segs", CTLFLAG_RW,
+ &rack_min_pace_time_seg_req, 6,
+ "How many segments have to be in the len to enforce min-pace-time");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "idle_reduce_high", CTLFLAG_RW,
+ &rack_reduce_largest_on_idle, 0,
+ "Should we reduce the largest cwnd seen to IW on idle reduction");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "bb_verbose", CTLFLAG_RW,
+ &rack_verbose_logging, 0,
+ "Should RACK black box logging be verbose");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "sackfiltering", CTLFLAG_RW,
+ &rack_use_sack_filter, 1,
+ "Do we use sack filtering?");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "delayed_ack", CTLFLAG_RW,
+ &rack_delayed_ack_time, 200,
+ "Delayed ack time (200ms)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlpminto", CTLFLAG_RW,
+ &rack_tlp_min, 10,
+ "TLP minimum timeout per the specification (10ms)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "precache", CTLFLAG_RW,
+ &rack_precache, 0,
+ "Where should we precache the mcopy (0 is not at all)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "sblklimit", CTLFLAG_RW,
+ &rack_sack_block_limit, 128,
+ "When do we start paying attention to small sack blocks");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "send_oldest", CTLFLAG_RW,
+ &rack_always_send_oldest, 1,
+ "Should we always send the oldest TLP and RACK-TLP");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "rack_tlp_in_recovery", CTLFLAG_RW,
+ &rack_tlp_in_recovery, 1,
+ "Can we do a TLP during recovery?");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "rack_tlimit", CTLFLAG_RW,
+ &rack_limited_retran, 0,
+ "How many times can a rack timeout drive out sends");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "minrto", CTLFLAG_RW,
+ &rack_rto_min, 0,
+ "Minimum RTO in ms -- set with caution below 1000 due to TLP");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "maxrto", CTLFLAG_RW,
+ &rack_rto_max, 0,
+ "Maxiumum RTO in ms -- should be at least as large as min_rto");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_retry", CTLFLAG_RW,
+ &rack_tlp_max_resend, 2,
+ "How many times does TLP retry a single segment or multiple with no ACK");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "recovery_loss_prop", CTLFLAG_RW,
+ &rack_use_proportional_reduce, 0,
+ "Should we proportionaly reduce cwnd based on the number of losses ");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "recovery_prop", CTLFLAG_RW,
+ &rack_proportional_rate, 10,
+ "What percent reduction per loss");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
+ &rack_lower_cwnd_at_tlp, 0,
+ "When a TLP completes a retran should we enter recovery?");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "hptsi_reduces", CTLFLAG_RW,
+ &rack_slot_reduction, 4,
+ "When setting a slot should we reduce by divisor");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "hptsi_every_seg", CTLFLAG_RW,
+ &rack_pace_every_seg, 1,
+ "Should we pace out every segment hptsi");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "hptsi_seg_max", CTLFLAG_RW,
+ &rack_hptsi_segments, 6,
+ "Should we pace out only a limited size of segments");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "prr_sendalot", CTLFLAG_RW,
+ &rack_send_a_lot_in_prr, 1,
+ "Send a lot in prr");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "minto", CTLFLAG_RW,
+ &rack_min_to, 1,
+ "Minimum rack timeout in milliseconds");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "earlyrecoveryseg", CTLFLAG_RW,
+ &rack_early_recovery_max_seg, 6,
+ "Max segments in early recovery");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "earlyrecovery", CTLFLAG_RW,
+ &rack_early_recovery, 1,
+ "Do we do early recovery with rack");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "reorder_thresh", CTLFLAG_RW,
+ &rack_reorder_thresh, 2,
+ "What factor for rack will be added when seeing reordering (shift right)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
+ &rack_tlp_thresh, 1,
+ "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "reorder_fade", CTLFLAG_RW,
+ &rack_reorder_fade, 0,
+ "Does reorder detection fade, if so how many ms (0 means never)");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "pktdelay", CTLFLAG_RW,
+ &rack_pkt_delay, 1,
+ "Extra RACK time (in ms) besides reordering thresh");
+ SYSCTL_ADD_S32(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "inc_var", CTLFLAG_RW,
+ &rack_inc_var, 0,
+ "Should rack add to the TLP timer the variance in rtt calculation");
+ rack_badfr = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "badfr", CTLFLAG_RD,
+ &rack_badfr, "Total number of bad FRs");
+ rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "badfr_bytes", CTLFLAG_RD,
+ &rack_badfr_bytes, "Total number of bad FRs");
+ rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "prrsndret", CTLFLAG_RD,
+ &rack_rtm_prr_retran,
+ "Total number of prr based retransmits");
+ rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "prrsndnew", CTLFLAG_RD,
+ &rack_rtm_prr_newdata,
+ "Total number of prr based new transmits");
+ rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tsnf", CTLFLAG_RD,
+ &rack_timestamp_mismatch,
+ "Total number of timestamps that we could not find the reported ts");
+ rack_find_high = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "findhigh", CTLFLAG_RD,
+ &rack_find_high,
+ "Total number of FIN causing find-high");
+ rack_reorder_seen = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "reordering", CTLFLAG_RD,
+ &rack_reorder_seen,
+ "Total number of times we added delay due to reordering");
+ rack_tlp_tot = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_to_total", CTLFLAG_RD,
+ &rack_tlp_tot,
+ "Total number of tail loss probe expirations");
+ rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_new", CTLFLAG_RD,
+ &rack_tlp_newdata,
+ "Total number of tail loss probe sending new data");
+
+ rack_tlp_retran = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_retran", CTLFLAG_RD,
+ &rack_tlp_retran,
+ "Total number of tail loss probe sending retransmitted data");
+ rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
+ &rack_tlp_retran_bytes,
+ "Total bytes of tail loss probe sending retransmitted data");
+ rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
+ &rack_tlp_retran_fail,
+ "Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
+ rack_to_tot = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "rack_to_tot", CTLFLAG_RD,
+ &rack_to_tot,
+ "Total number of times the rack to expired?");
+ rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "arm_rack", CTLFLAG_RD,
+ &rack_to_arm_rack,
+ "Total number of times the rack timer armed?");
+ rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "arm_tlp", CTLFLAG_RD,
+ &rack_to_arm_tlp,
+ "Total number of times the tlp timer armed?");
+ rack_paced_segments = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "paced", CTLFLAG_RD,
+ &rack_paced_segments,
+ "Total number of times a segment send caused hptsi");
+ rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "unpaced", CTLFLAG_RD,
+ &rack_unpaced_segments,
+ "Total number of times a segment did not cause hptsi");
+ rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "saw_enobufs", CTLFLAG_RD,
+ &rack_saw_enobuf,
+ "Total number of times a segment did not cause hptsi");
+ rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
+ &rack_saw_enetunreach,
+ "Total number of times a segment did not cause hptsi");
+ rack_to_alloc = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "allocs", CTLFLAG_RD,
+ &rack_to_alloc,
+ "Total allocations of tracking structures");
+ rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "allochard", CTLFLAG_RD,
+ &rack_to_alloc_hard,
+ "Total allocations done with sleeping the hard way");
+ rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "allocemerg", CTLFLAG_RD,
+ &rack_to_alloc_emerg,
+ "Total alocations done from emergency cache");
+ rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "sack_long", CTLFLAG_RD,
+ &rack_sack_proc_all,
+ "Total times we had to walk whole list for sack processing");
+
+ rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "sack_restart", CTLFLAG_RD,
+ &rack_sack_proc_restart,
+ "Total times we had to walk whole list due to a restart");
+ rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "sack_short", CTLFLAG_RD,
+ &rack_sack_proc_short,
+ "Total times we took shortcut for sack processing");
+ rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
+ &rack_enter_tlp_calc,
+ "Total times we called calc-tlp");
+ rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
+ &rack_used_tlpmethod,
+ "Total number of runt sacks");
+ rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
+ &rack_used_tlpmethod2,
+ "Total number of runt sacks 2");
+ rack_runt_sacks = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "runtsacks", CTLFLAG_RD,
+ &rack_runt_sacks,
+ "Total number of runt sacks");
+ rack_progress_drops = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "prog_drops", CTLFLAG_RD,
+ &rack_progress_drops,
+ "Total number of progress drops");
+ rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
+ &rack_input_idle_reduces,
+ "Total number of idle reductions on input");
+ rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "tlp_nada", CTLFLAG_RD,
+ &rack_tlp_does_nada,
+ "Total number of nada tlp calls");
+ COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "outsize", CTLFLAG_RD,
+ rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
+ COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
+ SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "opts", CTLFLAG_RD,
+ rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
+ SYSCTL_ADD_PROC(&rack_sysctl_ctx,
+ SYSCTL_CHILDREN(rack_sysctl_root),
+ OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
+ &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
+}
+
+static inline int32_t
+rack_progress_timeout_check(struct tcpcb *tp)
+{
+ if (tp->t_maxunacktime && tp->t_acktime && TSTMP_GT(ticks, tp->t_acktime)) {
+ if ((ticks - tp->t_acktime) >= tp->t_maxunacktime) {
+ /*
+ * There is an assumption that the caller
+ * will drop the connection so we will
+ * increment the counters here.
+ */
+ struct tcp_rack *rack;
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ counter_u64_add(rack_progress_drops, 1);
+#ifdef NETFLIX_STATS
+ TCPSTAT_INC(tcps_progdrops);
+#endif
+ rack_log_progress_event(rack, tp, ticks, PROGRESS_DROP, __LINE__);
+ return (1);
+ }
+ }
+ return (0);
+}
+
+
+static void
+rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.flex1 = TICKS_2_MSEC(rack->rc_tp->t_srtt >> TCP_RTT_SHIFT);
+ log.u_bbr.flex2 = to;
+ log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
+ log.u_bbr.flex4 = slot;
+ log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
+ log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
+ log.u_bbr.flex8 = which;
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_TIMERSTAR, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_to_event(struct tcp_rack *rack, int32_t to_num)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex8 = to_num;
+ log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
+ log.u_bbr.flex2 = rack->rc_rack_rtt;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_RTO, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, int32_t t,
+ uint32_t o_srtt, uint32_t o_var)
+{
+ if (tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = t;
+ log.u_bbr.flex2 = o_srtt;
+ log.u_bbr.flex3 = o_var;
+ log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
+ log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
+ log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt;
+ log.u_bbr.rttProp = rack->r_ctl.rack_rs.rs_rtt_tot;
+ log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
+ TCP_LOG_EVENT(tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_BBRRTT, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
+{
+ /*
+ * Log the rtt sample we are
+ * applying to the srtt algorithm in
+ * useconds.
+ */
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+ struct timeval tv;
+
+ /* Convert our ms to a microsecond */
+ log.u_bbr.flex1 = rtt * 1000;
+ log.u_bbr.timeStamp = tcp_get_usecs(&tv);
+ TCP_LOG_EVENTP(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ TCP_LOG_RTT, 0,
+ 0, &log, false, &tv);
+ }
+}
+
+
+static inline void
+rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line)
+{
+ if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = line;
+ log.u_bbr.flex2 = tick;
+ log.u_bbr.flex3 = tp->t_maxunacktime;
+ log.u_bbr.flex4 = tp->t_acktime;
+ log.u_bbr.flex8 = event;
+ TCP_LOG_EVENT(tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_PROGRESS, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = slot;
+ log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
+ log.u_bbr.flex8 = rack->rc_in_persist;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_BBRSND, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+ log.u_bbr.flex1 = did_out;
+ log.u_bbr.flex2 = nxt_pkt;
+ log.u_bbr.flex3 = way_out;
+ log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
+ log.u_bbr.flex7 = rack->r_wanted_output;
+ log.u_bbr.flex8 = rack->rc_in_persist;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_DOSEG_DONE, 0,
+ 0, &log, false);
+ }
+}
+
+
+static void
+rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot, uint8_t hpts_calling)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = slot;
+ log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
+ log.u_bbr.flex7 = hpts_calling;
+ log.u_bbr.flex8 = rack->rc_in_persist;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_JUSTRET, 0,
+ tlen, &log, false);
+ }
+}
+
+static void
+rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = line;
+ log.u_bbr.flex2 = 0;
+ log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
+ log.u_bbr.flex4 = 0;
+ log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
+ log.u_bbr.flex8 = hpts_removed;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_TIMERCANC, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
+{
+ if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.flex1 = timers;
+ log.u_bbr.flex2 = ret;
+ log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
+ log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
+ log.u_bbr.flex5 = cts;
+ TCP_LOG_EVENT(rack->rc_tp, NULL,
+ &rack->rc_inp->inp_socket->so_rcv,
+ &rack->rc_inp->inp_socket->so_snd,
+ BBR_LOG_TO_PROCESS, 0,
+ 0, &log, false);
+ }
+}
+
+static void
+rack_counter_destroy()
+{
+ counter_u64_free(rack_badfr);
+ counter_u64_free(rack_badfr_bytes);
+ counter_u64_free(rack_rtm_prr_retran);
+ counter_u64_free(rack_rtm_prr_newdata);
+ counter_u64_free(rack_timestamp_mismatch);
+ counter_u64_free(rack_reorder_seen);
+ counter_u64_free(rack_tlp_tot);
+ counter_u64_free(rack_tlp_newdata);
+ counter_u64_free(rack_tlp_retran);
+ counter_u64_free(rack_tlp_retran_bytes);
+ counter_u64_free(rack_tlp_retran_fail);
+ counter_u64_free(rack_to_tot);
+ counter_u64_free(rack_to_arm_rack);
+ counter_u64_free(rack_to_arm_tlp);
+ counter_u64_free(rack_paced_segments);
+ counter_u64_free(rack_unpaced_segments);
+ counter_u64_free(rack_saw_enobuf);
+ counter_u64_free(rack_saw_enetunreach);
+ counter_u64_free(rack_to_alloc_hard);
+ counter_u64_free(rack_to_alloc_emerg);
+ counter_u64_free(rack_sack_proc_all);
+ counter_u64_free(rack_sack_proc_short);
+ counter_u64_free(rack_sack_proc_restart);
+ counter_u64_free(rack_to_alloc);
+ counter_u64_free(rack_find_high);
+ counter_u64_free(rack_runt_sacks);
+ counter_u64_free(rack_enter_tlp_calc);
+ counter_u64_free(rack_used_tlpmethod);
+ counter_u64_free(rack_used_tlpmethod2);
+ counter_u64_free(rack_progress_drops);
+ counter_u64_free(rack_input_idle_reduces);
+ counter_u64_free(rack_tlp_does_nada);
+ COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
+ COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
+}
+
+static struct rack_sendmap *
+rack_alloc(struct tcp_rack *rack)
+{
+ struct rack_sendmap *rsm;
+
+ counter_u64_add(rack_to_alloc, 1);
+ rack->r_ctl.rc_num_maps_alloced++;
+ rsm = uma_zalloc(rack_zone, M_NOWAIT);
+ if (rsm) {
+ return (rsm);
+ }
+ if (rack->rc_free_cnt) {
+ counter_u64_add(rack_to_alloc_emerg, 1);
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
+ TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_next);
+ rack->rc_free_cnt--;
+ return (rsm);
+ }
+ return (NULL);
+}
+
+static void
+rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
+{
+ rack->r_ctl.rc_num_maps_alloced--;
+ if (rack->r_ctl.rc_tlpsend == rsm)
+ rack->r_ctl.rc_tlpsend = NULL;
+ if (rack->r_ctl.rc_next == rsm)
+ rack->r_ctl.rc_next = NULL;
+ if (rack->r_ctl.rc_sacklast == rsm)
+ rack->r_ctl.rc_sacklast = NULL;
+ if (rack->rc_free_cnt < rack_free_cache) {
+ memset(rsm, 0, sizeof(struct rack_sendmap));
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_next);
+ rack->rc_free_cnt++;
+ return;
+ }
+ uma_zfree(rack_zone, rsm);
+}
+
+/*
+ * CC wrapper hook functions
+ */
+static void
+rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, struct tcphdr *th, uint16_t nsegs,
+ uint16_t type, int32_t recovery)
+{
+#ifdef NETFLIX_STATS
+ int32_t gput;
+#endif
+#ifdef NETFLIX_CWV
+ u_long old_cwnd = tp->snd_cwnd;
+#endif
+
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ tp->ccv->nsegs = nsegs;
+ tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);
+ if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
+ uint32_t max;
+
+ max = rack->r_ctl.rc_early_recovery_segs * tp->t_maxseg;
+ if (tp->ccv->bytes_this_ack > max) {
+ tp->ccv->bytes_this_ack = max;
+ }
+ }
+ if (tp->snd_cwnd <= tp->snd_wnd)
+ tp->ccv->flags |= CCF_CWND_LIMITED;
+ else
+ tp->ccv->flags &= ~CCF_CWND_LIMITED;
+
+ if (type == CC_ACK) {
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
+ ((int32_t) tp->snd_cwnd) - tp->snd_wnd);
+ if ((tp->t_flags & TF_GPUTINPROG) &&
+ SEQ_GEQ(th->th_ack, tp->gput_ack)) {
+ gput = (((int64_t) (th->th_ack - tp->gput_seq)) << 3) /
+ max(1, tcp_ts_getticks() - tp->gput_ts);
+ stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
+ gput);
+ /*
+ * XXXLAS: This is a temporary hack, and should be
+ * chained off VOI_TCP_GPUT when stats(9) grows an
+ * API to deal with chained VOIs.
+ */
+ if (tp->t_stats_gput_prev > 0)
+ stats_voi_update_abs_s32(tp->t_stats,
+ VOI_TCP_GPUT_ND,
+ ((gput - tp->t_stats_gput_prev) * 100) /
+ tp->t_stats_gput_prev);
+ tp->t_flags &= ~TF_GPUTINPROG;
+ tp->t_stats_gput_prev = gput;
+
+ if (tp->t_maxpeakrate) {
+ /*
+ * We update t_peakrate_thr. This gives us roughly
+ * one update per round trip time.
+ */
+ tcp_update_peakrate_thr(tp);
+ }
+ }
+#endif
+ if (tp->snd_cwnd > tp->snd_ssthresh) {
+ tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
+ nsegs * V_tcp_abc_l_var * tp->t_maxseg);
+ if (tp->t_bytes_acked >= tp->snd_cwnd) {
+ tp->t_bytes_acked -= tp->snd_cwnd;
+ tp->ccv->flags |= CCF_ABC_SENTAWND;
+ }
+ } else {
+ tp->ccv->flags &= ~CCF_ABC_SENTAWND;
+ tp->t_bytes_acked = 0;
+ }
+ }
+ if (CC_ALGO(tp)->ack_received != NULL) {
+ /* XXXLAS: Find a way to live without this */
+ tp->ccv->curack = th->th_ack;
+ CC_ALGO(tp)->ack_received(tp->ccv, type);
+ }
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, tp->snd_cwnd);
+#endif
+ if (rack->r_ctl.rc_rack_largest_cwnd < tp->snd_cwnd) {
+ rack->r_ctl.rc_rack_largest_cwnd = tp->snd_cwnd;
+ }
+#ifdef NETFLIX_CWV
+ if (tp->cwv_enabled) {
+ /*
+ * Per RFC 7661: The behaviour in the non-validated phase is
+ * specified as: o A sender determines whether to increase
+ * the cwnd based upon whether it is cwnd-limited (see
+ * Section 4.5.3): * A sender that is cwnd-limited MAY use
+ * the standard TCP method to increase cwnd (i.e., the
+ * standard method permits a TCP sender that fully utilises
+ * the cwnd to increase the cwnd each time it receives an
+ * ACK). * A sender that is not cwnd-limited MUST NOT
+ * increase the cwnd when ACK packets are received in this
+ * phase (i.e., needs to avoid growing the cwnd when it has
+ * not recently sent using the current size of cwnd).
+ */
+ if ((tp->snd_cwnd > old_cwnd) &&
+ (tp->cwv_cwnd_valid == 0) &&
+ (!(tp->ccv->flags & CCF_CWND_LIMITED))) {
+ tp->snd_cwnd = old_cwnd;
+ }
+ /* Try to update pipeAck and NCWV state */
+ if (TCPS_HAVEESTABLISHED(tp->t_state) &&
+ !IN_RECOVERY(tp->t_flags)) {
+ uint32_t data = sbavail(&(tp->t_inpcb->inp_socket->so_snd));
+
+ tcp_newcwv_update_pipeack(tp, data);
+ }
+ }
+#endif
+ /* we enforce max peak rate if it is set. */
+ if (tp->t_peakrate_thr && tp->snd_cwnd > tp->t_peakrate_thr) {
+ tp->snd_cwnd = tp->t_peakrate_thr;
+ }
+}
+
+static void
+tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th)
+{
+ struct tcp_rack *rack;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ if (rack->r_ctl.rc_prr_sndcnt > 0)
+ rack->r_wanted_output++;
+}
+
+static void
+rack_post_recovery(struct tcpcb *tp, struct tcphdr *th)
+{
+ struct tcp_rack *rack;
+
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (CC_ALGO(tp)->post_recovery != NULL) {
+ tp->ccv->curack = th->th_ack;
+ CC_ALGO(tp)->post_recovery(tp->ccv);
+ }
+ /*
+ * Here we can in theory adjust cwnd to be based on the number of
+ * losses in the window (rack->r_ctl.rc_loss_count). This is done
+ * based on the rack_use_proportional flag.
+ */
+ if (rack->r_ctl.rc_prop_reduce && rack->r_ctl.rc_prop_rate) {
+ int32_t reduce;
+
+ reduce = (rack->r_ctl.rc_loss_count * rack->r_ctl.rc_prop_rate);
+ if (reduce > 50) {
+ reduce = 50;
+ }
+ tp->snd_cwnd -= ((reduce * tp->snd_cwnd) / 100);
+ } else {
+ if (tp->snd_cwnd > tp->snd_ssthresh) {
+ /* Drop us down to the ssthresh (1/2 cwnd at loss) */
+ tp->snd_cwnd = tp->snd_ssthresh;
+ }
+ }
+ if (rack->r_ctl.rc_prr_sndcnt > 0) {
+ /* Suck the next prr cnt back into cwnd */
+ tp->snd_cwnd += rack->r_ctl.rc_prr_sndcnt;
+ rack->r_ctl.rc_prr_sndcnt = 0;
+ }
+ EXIT_RECOVERY(tp->t_flags);
+
+
+#ifdef NETFLIX_CWV
+ if (tp->cwv_enabled) {
+ if ((tp->cwv_cwnd_valid == 0) &&
+ (tp->snd_cwv.in_recovery))
+ tcp_newcwv_end_recovery(tp);
+ }
+#endif
+}
+
+static void
+rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
+{
+ struct tcp_rack *rack;
+
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ switch (type) {
+ case CC_NDUPACK:
+/* rack->r_ctl.rc_ssthresh_set = 1;*/
+ if (!IN_FASTRECOVERY(tp->t_flags)) {
+ rack->r_ctl.rc_tlp_rtx_out = 0;
+ rack->r_ctl.rc_prr_delivered = 0;
+ rack->r_ctl.rc_prr_out = 0;
+ rack->r_ctl.rc_loss_count = 0;
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
+ tp->snd_recover = tp->snd_max;
+ if (tp->t_flags & TF_ECN_PERMIT)
+ tp->t_flags |= TF_ECN_SND_CWR;
+ }
+ break;
+ case CC_ECN:
+ if (!IN_CONGRECOVERY(tp->t_flags)) {
+ TCPSTAT_INC(tcps_ecn_rcwnd);
+ tp->snd_recover = tp->snd_max;
+ if (tp->t_flags & TF_ECN_PERMIT)
+ tp->t_flags |= TF_ECN_SND_CWR;
+ }
+ break;
+ case CC_RTO:
+ tp->t_dupacks = 0;
+ tp->t_bytes_acked = 0;
+ EXIT_RECOVERY(tp->t_flags);
+ tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 /
+ tp->t_maxseg) * tp->t_maxseg;
+ tp->snd_cwnd = tp->t_maxseg;
+ break;
+ case CC_RTO_ERR:
+ TCPSTAT_INC(tcps_sndrexmitbad);
+ /* RTO was unnecessary, so reset everything. */
+ tp->snd_cwnd = tp->snd_cwnd_prev;
+ tp->snd_ssthresh = tp->snd_ssthresh_prev;
+ tp->snd_recover = tp->snd_recover_prev;
+ if (tp->t_flags & TF_WASFRECOVERY)
+ ENTER_FASTRECOVERY(tp->t_flags);
+ if (tp->t_flags & TF_WASCRECOVERY)
+ ENTER_CONGRECOVERY(tp->t_flags);
+ tp->snd_nxt = tp->snd_max;
+ tp->t_badrxtwin = 0;
+ break;
+ }
+
+ if (CC_ALGO(tp)->cong_signal != NULL) {
+ if (th != NULL)
+ tp->ccv->curack = th->th_ack;
+ CC_ALGO(tp)->cong_signal(tp->ccv, type);
+ }
+#ifdef NETFLIX_CWV
+ if (tp->cwv_enabled) {
+ if (tp->snd_cwv.in_recovery == 0 && IN_RECOVERY(tp->t_flags)) {
+ tcp_newcwv_enter_recovery(tp);
+ }
+ if (type == CC_RTO) {
+ tcp_newcwv_reset(tp);
+ }
+ }
+#endif
+}
+
+
+
+static inline void
+rack_cc_after_idle(struct tcpcb *tp, int reduce_largest)
+{
+ uint32_t i_cwnd;
+
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+
+#ifdef NETFLIX_STATS
+ TCPSTAT_INC(tcps_idle_restarts);
+ if (tp->t_state == TCPS_ESTABLISHED)
+ TCPSTAT_INC(tcps_idle_estrestarts);
+#endif
+ if (CC_ALGO(tp)->after_idle != NULL)
+ CC_ALGO(tp)->after_idle(tp->ccv);
+
+ if (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;
+ }
+ if (reduce_largest) {
+ /*
+ * Do we reduce the largest cwnd to make
+ * rack play nice on restart hptsi wise?
+ */
+ if (((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rack_largest_cwnd > i_cwnd)
+ ((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rack_largest_cwnd = i_cwnd;
+ }
+ /*
+ * Being idle is no differnt than the initial window. If the cc
+ * clamps it down below the initial window raise it to the initial
+ * window.
+ */
+ if (tp->snd_cwnd < i_cwnd) {
+ tp->snd_cwnd = i_cwnd;
+ }
+}
+
+
+/*
+ * Indicate whether this ack should be delayed. We can delay the ack if
+ * following conditions are met:
+ * - There is no delayed ack timer in progress.
+ * - Our last ack wasn't a 0-sized window. We never want to delay
+ * the ack that opens up a 0-sized window.
+ * - LRO wasn't used for this segment. We make sure by checking that the
+ * segment size is not larger than the MSS.
+ * - Delayed acks are enabled or this is a half-synchronized T/TCP
+ * connection.
+ */
+#define DELAY_ACK(tp, tlen) \
+ (((tp->t_flags & TF_RXWIN0SENT) == 0) && \
+ ((tp->t_flags & TF_DELACK) == 0) && \
+ (tlen <= tp->t_maxseg) && \
+ (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
+
+static inline void
+rack_calc_rwin(struct socket *so, struct tcpcb *tp)
+{
+ int32_t win;
+
+ /*
+ * Calculate amount of space in receive window, and then do TCP
+ * input processing. Receive window is amount of space in rcv queue,
+ * but not less than advertised window.
+ */
+ win = sbspace(&so->so_rcv);
+ if (win < 0)
+ win = 0;
+ tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));
+}
+
+static void
+rack_do_drop(struct mbuf *m, struct tcpcb *tp, int32_t * ti_locked)
+{
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ /*
+ * Drop space held by incoming segment and return.
+ */
+ if (tp != NULL)
+ INP_WUNLOCK(tp->t_inpcb);
+ if (m)
+ m_freem(m);
+}
+
+static void
+rack_do_dropwithreset(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th, int32_t * ti_locked, int32_t rstreason, int32_t tlen)
+{
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ if (tp != NULL) {
+ tcp_dropwithreset(m, th, tp, tlen, rstreason);
+ INP_WUNLOCK(tp->t_inpcb);
+ } else
+ tcp_dropwithreset(m, th, NULL, tlen, rstreason);
+}
+
+/*
+ * The value in ret_val informs the caller
+ * if we dropped the tcb (and lock) or not.
+ * 1 = we dropped it, 0 = the TCB is still locked
+ * and valid.
+ */
+static void
+rack_do_dropafterack(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th, int32_t * ti_locked, int32_t thflags, int32_t tlen, int32_t * ret_val)
+{
+ /*
+ * Generate an ACK dropping incoming segment if it occupies sequence
+ * space, where the ACK reflects our state.
+ *
+ * We can now skip the test for the RST flag since all paths to this
+ * code happen after packets containing RST have been dropped.
+ *
+ * In the SYN-RECEIVED state, don't send an ACK unless the segment
+ * we received passes the SYN-RECEIVED ACK test. If it fails send a
+ * RST. This breaks the loop in the "LAND" DoS attack, and also
+ * prevents an ACK storm between two listening ports that have been
+ * sent forged SYN segments, each with the source address of the
+ * other.
+ */
+ struct tcp_rack *rack;
+
+ if (tp->t_state == TCPS_SYN_RECEIVED && (thflags & TH_ACK) &&
+ (SEQ_GT(tp->snd_una, th->th_ack) ||
+ SEQ_GT(th->th_ack, tp->snd_max))) {
+ *ret_val = 1;
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return;
+ } else
+ *ret_val = 0;
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ rack->r_wanted_output++;
+ tp->t_flags |= TF_ACKNOW;
+ if (m)
+ m_freem(m);
+}
+
+
+static int
+rack_process_rst(struct mbuf *m, struct tcphdr *th, struct socket *so, struct tcpcb *tp, int32_t * ti_locked)
+{
+ /*
+ * RFC5961 Section 3.2
+ *
+ * - RST drops connection only if SEG.SEQ == RCV.NXT. - If RST is in
+ * window, we send challenge ACK.
+ *
+ * Note: to take into account delayed ACKs, we should test against
+ * last_ack_sent instead of rcv_nxt. Note 2: we handle special case
+ * of closed window, not covered by the RFC.
+ */
+ int dropped = 0;
+
+ if ((SEQ_GEQ(th->th_seq, (tp->last_ack_sent - 1)) &&
+ SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
+ (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) {
+
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ KASSERT(*ti_locked == TI_RLOCKED,
+ ("%s: TH_RST ti_locked %d, th %p tp %p",
+ __func__, *ti_locked, th, tp));
+ KASSERT(tp->t_state != TCPS_SYN_SENT,
+ ("%s: TH_RST for TCPS_SYN_SENT th %p tp %p",
+ __func__, th, tp));
+
+ if (V_tcp_insecure_rst ||
+ (tp->last_ack_sent == th->th_seq) ||
+ (tp->rcv_nxt == th->th_seq) ||
+ ((tp->last_ack_sent - 1) == th->th_seq)) {
+ TCPSTAT_INC(tcps_drops);
+ /* Drop the connection. */
+ switch (tp->t_state) {
+ case TCPS_SYN_RECEIVED:
+ so->so_error = ECONNREFUSED;
+ goto close;
+ case TCPS_ESTABLISHED:
+ case TCPS_FIN_WAIT_1:
+ case TCPS_FIN_WAIT_2:
+ case TCPS_CLOSE_WAIT:
+ case TCPS_CLOSING:
+ case TCPS_LAST_ACK:
+ so->so_error = ECONNRESET;
+ close:
+ tcp_state_change(tp, TCPS_CLOSED);
+ /* FALLTHROUGH */
+ default:
+ tp = tcp_close(tp);
+ }
+ dropped = 1;
+ rack_do_drop(m, tp, ti_locked);
+ } else {
+ TCPSTAT_INC(tcps_badrst);
+ /* Send challenge ACK. */
+ tcp_respond(tp, mtod(m, void *), th, m,
+ tp->rcv_nxt, tp->snd_nxt, TH_ACK);
+ tp->last_ack_sent = tp->rcv_nxt;
+ }
+ } else {
+ m_freem(m);
+ }
+ return (dropped);
+}
+
+/*
+ * The value in ret_val informs the caller
+ * if we dropped the tcb (and lock) or not.
+ * 1 = we dropped it, 0 = the TCB is still locked
+ * and valid.
+ */
+static void
+rack_challenge_ack(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t * ti_locked, int32_t * ret_val)
+{
+ KASSERT(*ti_locked == TI_RLOCKED,
+ ("tcp_do_segment: TH_SYN ti_locked %d", *ti_locked));
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+
+ TCPSTAT_INC(tcps_badsyn);
+ if (V_tcp_insecure_syn &&
+ SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) {
+ tp = tcp_drop(tp, ECONNRESET);
+ *ret_val = 1;
+ rack_do_drop(m, tp, ti_locked);
+ } else {
+ /* Send challenge ACK. */
+ tcp_respond(tp, mtod(m, void *), th, m, tp->rcv_nxt,
+ tp->snd_nxt, TH_ACK);
+ tp->last_ack_sent = tp->rcv_nxt;
+ m = NULL;
+ *ret_val = 0;
+ rack_do_drop(m, NULL, ti_locked);
+ }
+}
+
+/*
+ * rack_ts_check returns 1 for you should not proceed. It places
+ * in ret_val what should be returned 1/0 by the caller. The 1 indicates
+ * that the TCB is unlocked and probably dropped. The 0 indicates the
+ * TCB is still valid and locked.
+ */
+static int
+rack_ts_check(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t * ti_locked, int32_t tlen, int32_t thflags, int32_t * ret_val)
+{
+
+ /* Check to see if ts_recent is over 24 days old. */
+ if (tcp_ts_getticks() - tp->ts_recent_age > TCP_PAWS_IDLE) {
+ /*
+ * Invalidate ts_recent. If this segment updates ts_recent,
+ * the age will be reset later and ts_recent will get a
+ * valid value. If it does not, setting ts_recent to zero
+ * will at least satisfy the requirement that zero be placed
+ * in the timestamp echo reply when ts_recent isn't valid.
+ * The age isn't reset until we get a valid ts_recent
+ * because we don't want out-of-order segments to be dropped
+ * when ts_recent is old.
+ */
+ tp->ts_recent = 0;
+ } else {
+ TCPSTAT_INC(tcps_rcvduppack);
+ TCPSTAT_ADD(tcps_rcvdupbyte, tlen);
+ TCPSTAT_INC(tcps_pawsdrop);
+ *ret_val = 0;
+ if (tlen) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ }
+ return (1);
+ }
+ return (0);
+}
+
+/*
+ * rack_drop_checks returns 1 for you should not proceed. It places
+ * in ret_val what should be returned 1/0 by the caller. The 1 indicates
+ * that the TCB is unlocked and probably dropped. The 0 indicates the
+ * TCB is still valid and locked.
+ */
+static int
+rack_drop_checks(struct tcpopt *to, struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int32_t * tlenp, int32_t * ti_locked, int32_t * thf, int32_t * drop_hdrlen, int32_t * ret_val)
+{
+ int32_t todrop;
+ int32_t thflags;
+ int32_t tlen;
+
+ thflags = *thf;
+ tlen = *tlenp;
+ todrop = tp->rcv_nxt - th->th_seq;
+ if (todrop > 0) {
+ if (thflags & TH_SYN) {
+ thflags &= ~TH_SYN;
+ th->th_seq++;
+ if (th->th_urp > 1)
+ th->th_urp--;
+ else
+ thflags &= ~TH_URG;
+ todrop--;
+ }
+ /*
+ * Following if statement from Stevens, vol. 2, p. 960.
+ */
+ if (todrop > tlen
+ || (todrop == tlen && (thflags & TH_FIN) == 0)) {
+ /*
+ * Any valid FIN must be to the left of the window.
+ * At this point the FIN must be a duplicate or out
+ * of sequence; drop it.
+ */
+ thflags &= ~TH_FIN;
+ /*
+ * Send an ACK to resynchronize and drop any data.
+ * But keep on processing for RST or ACK.
+ */
+ tp->t_flags |= TF_ACKNOW;
+ todrop = tlen;
+ TCPSTAT_INC(tcps_rcvduppack);
+ TCPSTAT_ADD(tcps_rcvdupbyte, todrop);
+ } else {
+ TCPSTAT_INC(tcps_rcvpartduppack);
+ TCPSTAT_ADD(tcps_rcvpartdupbyte, todrop);
+ }
+ *drop_hdrlen += todrop; /* drop from the top afterwards */
+ th->th_seq += todrop;
+ tlen -= todrop;
+ if (th->th_urp > todrop)
+ th->th_urp -= todrop;
+ else {
+ thflags &= ~TH_URG;
+ th->th_urp = 0;
+ }
+ }
+ /*
+ * If segment ends after window, drop trailing data (and PUSH and
+ * FIN); if nothing left, just ACK.
+ */
+ todrop = (th->th_seq + tlen) - (tp->rcv_nxt + tp->rcv_wnd);
+ if (todrop > 0) {
+ TCPSTAT_INC(tcps_rcvpackafterwin);
+ if (todrop >= tlen) {
+ TCPSTAT_ADD(tcps_rcvbyteafterwin, tlen);
+ /*
+ * If window is closed can only take segments at
+ * window edge, and have to drop data and PUSH from
+ * incoming segments. Continue processing, but
+ * remember to ack. Otherwise, drop segment and
+ * ack.
+ */
+ if (tp->rcv_wnd == 0 && th->th_seq == tp->rcv_nxt) {
+ tp->t_flags |= TF_ACKNOW;
+ TCPSTAT_INC(tcps_rcvwinprobe);
+ } else {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, ret_val);
+ return (1);
+ }
+ } else
+ TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
+ m_adj(m, -todrop);
+ tlen -= todrop;
+ thflags &= ~(TH_PUSH | TH_FIN);
+ }
+ *thf = thflags;
+ *tlenp = tlen;
+ return (0);
+}
+
+static struct rack_sendmap *
+rack_find_lowest_rsm(struct tcp_rack *rack)
+{
+ struct rack_sendmap *rsm;
+
+ /*
+ * Walk the time-order transmitted list looking for an rsm that is
+ * not acked. This will be the one that was sent the longest time
+ * ago that is still outstanding.
+ */
+ TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
+ if (rsm->r_flags & RACK_ACKED) {
+ continue;
+ }
+ goto finish;
+ }
+finish:
+ return (rsm);
+}
+
+static struct rack_sendmap *
+rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
+{
+ struct rack_sendmap *prsm;
+
+ /*
+ * Walk the sequence order list backward until we hit and arrive at
+ * the highest seq not acked. In theory when this is called it
+ * should be the last segment (which it was not).
+ */
+ counter_u64_add(rack_find_high, 1);
+ prsm = rsm;
+ TAILQ_FOREACH_REVERSE_FROM(prsm, &rack->r_ctl.rc_map, rack_head, r_next) {
+ if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
+ continue;
+ }
+ return (prsm);
+ }
+ return (NULL);
+}
+
+
+static uint32_t
+rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
+{
+ int32_t lro;
+ uint32_t thresh;
+
+ /*
+ * lro is the flag we use to determine if we have seen reordering.
+ * If it gets set we have seen reordering. The reorder logic either
+ * works in one of two ways:
+ *
+ * If reorder-fade is configured, then we track the last time we saw
+ * re-ordering occur. If we reach the point where enough time as
+ * passed we no longer consider reordering has occuring.
+ *
+ * Or if reorder-face is 0, then once we see reordering we consider
+ * the connection to alway be subject to reordering and just set lro
+ * to 1.
+ *
+ * In the end if lro is non-zero we add the extra time for
+ * reordering in.
+ */
+ if (srtt == 0)
+ srtt = 1;
+ if (rack->r_ctl.rc_reorder_ts) {
+ if (rack->r_ctl.rc_reorder_fade) {
+ if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
+ lro = cts - rack->r_ctl.rc_reorder_ts;
+ if (lro == 0) {
+ /*
+ * No time as passed since the last
+ * reorder, mark it as reordering.
+ */
+ lro = 1;
+ }
+ } else {
+ /* Negative time? */
+ lro = 0;
+ }
+ if (lro > rack->r_ctl.rc_reorder_fade) {
+ /* Turn off reordering seen too */
+ rack->r_ctl.rc_reorder_ts = 0;
+ lro = 0;
+ }
+ } else {
+ /* Reodering does not fade */
+ lro = 1;
+ }
+ } else {
+ lro = 0;
+ }
+ thresh = srtt + rack->r_ctl.rc_pkt_delay;
+ if (lro) {
+ /* It must be set, if not you get 1/4 rtt */
+ if (rack->r_ctl.rc_reorder_shift)
+ thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
+ else
+ thresh += (srtt >> 2);
+ } else {
+ thresh += 1;
+ }
+ /* We don't let the rack timeout be above a RTO */
+
+ if (thresh > TICKS_2_MSEC(rack->rc_tp->t_rxtcur)) {
+ thresh = TICKS_2_MSEC(rack->rc_tp->t_rxtcur);
+ }
+ /* And we don't want it above the RTO max either */
+ if (thresh > rack_rto_max) {
+ thresh = rack_rto_max;
+ }
+ return (thresh);
+}
+
+static uint32_t
+rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, uint32_t srtt)
+{
+ struct rack_sendmap *prsm;
+ uint32_t thresh, len;
+ int maxseg;
+
+ if (srtt == 0)
+ srtt = 1;
+ if (rack->r_ctl.rc_tlp_threshold)
+ thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
+ else
+ thresh = (srtt * 2);
+
+ /* Get the previous sent packet, if any */
+ maxseg = tcp_maxseg(tp);
+ counter_u64_add(rack_enter_tlp_calc, 1);
+ len = rsm->r_end - rsm->r_start;
+ if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
+ /* Exactly like the ID */
+ if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= maxseg) {
+ uint32_t alt_thresh;
+ /*
+ * Compensate for delayed-ack with the d-ack time.
+ */
+ counter_u64_add(rack_used_tlpmethod, 1);
+ alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
+ if (alt_thresh > thresh)
+ thresh = alt_thresh;
+ }
+ } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
+ /* 2.1 behavior */
+ prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
+ if (prsm && (len <= maxseg)) {
+ /*
+ * Two packets outstanding, thresh should be (2*srtt) +
+ * possible inter-packet delay (if any).
+ */
+ uint32_t inter_gap = 0;
+ int idx, nidx;
+
+ counter_u64_add(rack_used_tlpmethod, 1);
+ idx = rsm->r_rtr_cnt - 1;
+ nidx = prsm->r_rtr_cnt - 1;
+ if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
+ /* Yes it was sent later (or at the same time) */
+ inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
+ }
+ thresh += inter_gap;
+ } else if (len <= maxseg) {
+ /*
+ * Possibly compensate for delayed-ack.
+ */
+ uint32_t alt_thresh;
+
+ counter_u64_add(rack_used_tlpmethod2, 1);
+ alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
+ if (alt_thresh > thresh)
+ thresh = alt_thresh;
+ }
+ } else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
+ /* 2.2 behavior */
+ if (len <= maxseg) {
+ uint32_t alt_thresh;
+ /*
+ * Compensate for delayed-ack with the d-ack time.
+ */
+ counter_u64_add(rack_used_tlpmethod, 1);
+ alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
+ if (alt_thresh > thresh)
+ thresh = alt_thresh;
+ }
+ }
+ /* Not above an RTO */
+ if (thresh > TICKS_2_MSEC(tp->t_rxtcur)) {
+ thresh = TICKS_2_MSEC(tp->t_rxtcur);
+ }
+ /* Not above a RTO max */
+ if (thresh > rack_rto_max) {
+ thresh = rack_rto_max;
+ }
+ /* Apply user supplied min TLP */
+ if (thresh < rack_tlp_min) {
+ thresh = rack_tlp_min;
+ }
+ return (thresh);
+}
+
+static struct rack_sendmap *
+rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
+{
+ /*
+ * Check to see that we don't need to fall into recovery. We will
+ * need to do so if our oldest transmit is past the time we should
+ * have had an ack.
+ */
+ struct tcp_rack *rack;
+ struct rack_sendmap *rsm;
+ int32_t idx;
+ uint32_t srtt_cur, srtt, thresh;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (TAILQ_EMPTY(&rack->r_ctl.rc_map)) {
+ return (NULL);
+ }
+ srtt_cur = tp->t_srtt >> TCP_RTT_SHIFT;
+ srtt = TICKS_2_MSEC(srtt_cur);
+ if (rack->rc_rack_rtt && (srtt > rack->rc_rack_rtt))
+ srtt = rack->rc_rack_rtt;
+
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ if (rsm == NULL)
+ return (NULL);
+
+ if (rsm->r_flags & RACK_ACKED) {
+ rsm = rack_find_lowest_rsm(rack);
+ if (rsm == NULL)
+ return (NULL);
+ }
+ idx = rsm->r_rtr_cnt - 1;
+ thresh = rack_calc_thresh_rack(rack, srtt, tsused);
+ if (tsused < rsm->r_tim_lastsent[idx]) {
+ return (NULL);
+ }
+ if ((tsused - rsm->r_tim_lastsent[idx]) < thresh) {
+ return (NULL);
+ }
+ /* Ok if we reach here we are over-due */
+ rack->r_ctl.rc_rsm_start = rsm->r_start;
+ rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
+ rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
+ rack_cong_signal(tp, NULL, CC_NDUPACK);
+ return (rsm);
+}
+
+static uint32_t
+rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
+{
+ int32_t t;
+ int32_t tt;
+ uint32_t ret_val;
+
+ t = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT) + ((tp->t_rttvar * 4) >> TCP_RTT_SHIFT));
+ TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
+ tcp_persmin, tcp_persmax);
+ if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
+ tp->t_rxtshift++;
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
+ ret_val = (uint32_t)tt;
+ return (ret_val);
+}
+
+static uint32_t
+rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ /*
+ * Start the FR timer, we do this based on getting the first one in
+ * the rc_tmap. Note that if its NULL we must stop the timer. in all
+ * events we need to stop the running timer (if its running) before
+ * starting the new one.
+ */
+ uint32_t thresh, exp, to, srtt, time_since_sent;
+ uint32_t srtt_cur;
+ int32_t idx;
+ int32_t is_tlp_timer = 0;
+ struct rack_sendmap *rsm;
+
+ if (rack->t_timers_stopped) {
+ /* All timers have been stopped none are to run */
+ return (0);
+ }
+ if (rack->rc_in_persist) {
+ /* We can't start any timer in persists */
+ return (rack_get_persists_timer_val(tp, rack));
+ }
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ if (rsm == NULL) {
+ /* Nothing on the send map */
+activate_rxt:
+ if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
+ to = TICKS_2_MSEC(tp->t_rxtcur);
+ if (to == 0)
+ to = 1;
+ return (to);
+ }
+ return (0);
+ }
+ if (rsm->r_flags & RACK_ACKED) {
+ rsm = rack_find_lowest_rsm(rack);
+ if (rsm == NULL) {
+ /* No lowest? */
+ goto activate_rxt;
+ }
+ }
+ /* Convert from ms to usecs */
+ if (rsm->r_flags & RACK_SACK_PASSED) {
+ if ((tp->t_flags & TF_SENTFIN) &&
+ ((tp->snd_max - tp->snd_una) == 1) &&
+ (rsm->r_flags & RACK_HAS_FIN)) {
+ /*
+ * We don't start a rack timer if all we have is a
+ * FIN outstanding.
+ */
+ goto activate_rxt;
+ }
+ if (tp->t_srtt) {
+ srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT);
+ srtt = TICKS_2_MSEC(srtt_cur);
+ } else
+ srtt = RACK_INITIAL_RTO;
+
+ thresh = rack_calc_thresh_rack(rack, srtt, cts);
+ idx = rsm->r_rtr_cnt - 1;
+ exp = rsm->r_tim_lastsent[idx] + thresh;
+ if (SEQ_GEQ(exp, cts)) {
+ to = exp - cts;
+ if (to < rack->r_ctl.rc_min_to) {
+ to = rack->r_ctl.rc_min_to;
+ }
+ } else {
+ to = rack->r_ctl.rc_min_to;
+ }
+ } else {
+ /* Ok we need to do a TLP not RACK */
+ if ((rack->rc_tlp_in_progress != 0) ||
+ (rack->r_ctl.rc_tlp_rtx_out != 0)) {
+ /*
+ * The previous send was a TLP or a tlp_rtx is in
+ * process.
+ */
+ goto activate_rxt;
+ }
+ rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
+ if (rsm == NULL) {
+ /* We found no rsm to TLP with. */
+ goto activate_rxt;
+ }
+ if (rsm->r_flags & RACK_HAS_FIN) {
+ /* If its a FIN we dont do TLP */
+ rsm = NULL;
+ goto activate_rxt;
+ }
+ idx = rsm->r_rtr_cnt - 1;
+ if (TSTMP_GT(cts, rsm->r_tim_lastsent[idx]))
+ time_since_sent = cts - rsm->r_tim_lastsent[idx];
+ else
+ time_since_sent = 0;
+ is_tlp_timer = 1;
+ if (tp->t_srtt) {
+ srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT);
+ srtt = TICKS_2_MSEC(srtt_cur);
+ } else
+ srtt = RACK_INITIAL_RTO;
+ thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
+ if (thresh > time_since_sent)
+ to = thresh - time_since_sent;
+ else
+ to = rack->r_ctl.rc_min_to;
+ if (to > TCPTV_REXMTMAX) {
+ /*
+ * If the TLP time works out to larger than the max
+ * RTO lets not do TLP.. just RTO.
+ */
+ goto activate_rxt;
+ }
+ if (rsm->r_start != rack->r_ctl.rc_last_tlp_seq) {
+ /*
+ * The tail is no longer the last one I did a probe
+ * on
+ */
+ rack->r_ctl.rc_tlp_seg_send_cnt = 0;
+ rack->r_ctl.rc_last_tlp_seq = rsm->r_start;
+ }
+ }
+ if (is_tlp_timer == 0) {
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
+ } else {
+ if ((rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) ||
+ (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) {
+ /*
+ * We have exceeded how many times we can retran the
+ * current TLP timer, switch to the RTO timer.
+ */
+ goto activate_rxt;
+ } else {
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
+ }
+ }
+ if (to == 0)
+ to = 1;
+ return (to);
+}
+
+static void
+rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ if (rack->rc_in_persist == 0) {
+ if (((tp->t_flags & TF_SENTFIN) == 0) &&
+ (tp->snd_max - tp->snd_una) >= sbavail(&rack->rc_inp->inp_socket->so_snd))
+ /* Must need to send more data to enter persist */
+ return;
+ rack->r_ctl.rc_went_idle_time = cts;
+ rack_timer_cancel(tp, rack, cts, __LINE__);
+ tp->t_rxtshift = 0;
+ rack->rc_in_persist = 1;
+ }
+}
+
+static void
+rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack)
+{
+ if (rack->rc_inp->inp_in_hpts) {
+ tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
+ rack->r_ctl.rc_hpts_flags = 0;
+ }
+ rack->rc_in_persist = 0;
+ rack->r_ctl.rc_went_idle_time = 0;
+ tp->t_flags &= ~TF_FORCEDATA;
+ tp->t_rxtshift = 0;
+}
+
+static void
+rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts, int32_t line,
+ int32_t slot, uint32_t tot_len_this_send, int32_t frm_out_sbavail)
+{
+ struct inpcb *inp;
+ uint32_t delayed_ack = 0;
+ uint32_t hpts_timeout;
+ uint8_t stopped;
+ uint32_t left = 0;
+
+ inp = tp->t_inpcb;
+ if (inp->inp_in_hpts) {
+ /* A previous call is already set up */
+ return;
+ }
+ if (tp->t_state == TCPS_CLOSED) {
+ return;
+ }
+ stopped = rack->rc_tmr_stopped;
+ if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
+ left = rack->r_ctl.rc_timer_exp - cts;
+ }
+ rack->r_ctl.rc_timer_exp = 0;
+ if (rack->rc_inp->inp_in_hpts == 0) {
+ rack->r_ctl.rc_hpts_flags = 0;
+ }
+ if (slot) {
+ /* We are hptsi too */
+ rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
+ } else if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
+ /*
+ * We are still left on the hpts when the to goes
+ * it will be for output.
+ */
+ if (TSTMP_GT(cts, rack->r_ctl.rc_last_output_to))
+ slot = cts - rack->r_ctl.rc_last_output_to;
+ else
+ slot = 1;
+ }
+ if ((tp->snd_wnd == 0) && TCPS_HAVEESTABLISHED(tp->t_state)) {
+ /* No send window.. we must enter persist */
+ rack_enter_persist(tp, rack, cts);
+ } else if ((frm_out_sbavail &&
+ (frm_out_sbavail > (tp->snd_max - tp->snd_una)) &&
+ (tp->snd_wnd < tp->t_maxseg)) &&
+ TCPS_HAVEESTABLISHED(tp->t_state)) {
+ /*
+ * If we have no window or we can't send a segment (and have
+ * data to send.. we cheat here and frm_out_sbavail is
+ * passed in with the sbavail(sb) only from bbr_output) and
+ * we are established, then we must enter persits (if not
+ * already in persits).
+ */
+ rack_enter_persist(tp, rack, cts);
+ }
+ hpts_timeout = rack_timer_start(tp, rack, cts);
+ if (tp->t_flags & TF_DELACK) {
+ delayed_ack = tcp_delacktime;
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
+ }
+ if (delayed_ack && ((hpts_timeout == 0) ||
+ (delayed_ack < hpts_timeout)))
+ hpts_timeout = delayed_ack;
+ else
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
+ /*
+ * If no timers are going to run and we will fall off the hptsi
+ * wheel, we resort to a keep-alive timer if its configured.
+ */
+ if ((hpts_timeout == 0) &&
+ (slot == 0)) {
+ if ((tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
+ (tp->t_state <= TCPS_CLOSING)) {
+ /*
+ * Ok we have no timer (persists, rack, tlp, rxt or
+ * del-ack), we don't have segments being paced. So
+ * all that is left is the keepalive timer.
+ */
+ if (TCPS_HAVEESTABLISHED(tp->t_state)) {
+ /* Get the established keep-alive time */
+ hpts_timeout = TP_KEEPIDLE(tp);
+ } else {
+ /* Get the initial setup keep-alive time */
+ hpts_timeout = TP_KEEPINIT(tp);
+ }
+ rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
+ }
+ }
+ if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
+ (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
+ /*
+ * RACK, TLP, persists and RXT timers all are restartable
+ * based on actions input .. i.e we received a packet (ack
+ * or sack) and that changes things (rw, or snd_una etc).
+ * Thus we can restart them with a new value. For
+ * keep-alive, delayed_ack we keep track of what was left
+ * and restart the timer with a smaller value.
+ */
+ if (left < hpts_timeout)
+ hpts_timeout = left;
+ }
+ if (hpts_timeout) {
+ /*
+ * Hack alert for now we can't time-out over 2,147,483
+ * seconds (a bit more than 596 hours), which is probably ok
+ * :).
+ */
+ if (hpts_timeout > 0x7ffffffe)
+ hpts_timeout = 0x7ffffffe;
+ rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
+ }
+ if (slot) {
+ rack->r_ctl.rc_last_output_to = cts + slot;
+ if ((hpts_timeout == 0) || (hpts_timeout > slot)) {
+ if (rack->rc_inp->inp_in_hpts == 0)
+ tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(slot));
+ rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
+ } else {
+ /*
+ * Arrange for the hpts to kick back in after the
+ * t-o if the t-o does not cause a send.
+ */
+ if (rack->rc_inp->inp_in_hpts == 0)
+ tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout));
+ rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
+ }
+ } else if (hpts_timeout) {
+ if (rack->rc_inp->inp_in_hpts == 0)
+ tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout));
+ rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
+ } else {
+ /* No timer starting */
+#ifdef INVARIANTS
+ if (SEQ_GT(tp->snd_max, tp->snd_una)) {
+ panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
+ tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
+ }
+#endif
+ }
+ rack->rc_tmr_stopped = 0;
+ if (slot)
+ rack_log_type_bbrsnd(rack, tot_len_this_send, slot, cts);
+}
+
+/*
+ * RACK Timer, here we simply do logging and house keeping.
+ * the normal rack_output() function will call the
+ * appropriate thing to check if we need to do a RACK retransmit.
+ * We return 1, saying don't proceed with rack_output only
+ * when all timers have been stopped (destroyed PCB?).
+ */
+static int
+rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ /*
+ * This timer simply provides an internal trigger to send out data.
+ * The check_recovery_mode call will see if there are needed
+ * retransmissions, if so we will enter fast-recovery. The output
+ * call may or may not do the same thing depending on sysctl
+ * settings.
+ */
+ struct rack_sendmap *rsm;
+ int32_t recovery;
+
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
+ /* Its not time yet */
+ return (0);
+ }
+ rack_log_to_event(rack, RACK_TO_FRM_RACK);
+ recovery = IN_RECOVERY(tp->t_flags);
+ counter_u64_add(rack_to_tot, 1);
+ if (rack->r_state && (rack->r_state != tp->t_state))
+ rack_set_state(tp, rack);
+ rsm = rack_check_recovery_mode(tp, cts);
+ if (rsm) {
+ uint32_t rtt;
+
+ rtt = rack->rc_rack_rtt;
+ if (rtt == 0)
+ rtt = 1;
+ if ((recovery == 0) &&
+ (rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg)) {
+ /*
+ * The rack-timeout that enter's us into recovery
+ * will force out one MSS and set us up so that we
+ * can do one more send in 2*rtt (transitioning the
+ * rack timeout into a rack-tlp).
+ */
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ } else if ((rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg) &&
+ ((rsm->r_end - rsm->r_start) > rack->r_ctl.rc_prr_sndcnt)) {
+ /*
+ * When a rack timer goes, we have to send at
+ * least one segment. They will be paced a min of 1ms
+ * apart via the next rack timer (or further
+ * if the rack timer dictates it).
+ */
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ }
+ } else {
+ /* This is a case that should happen rarely if ever */
+ counter_u64_add(rack_tlp_does_nada, 1);
+#ifdef TCP_BLACKBOX
+ tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
+#endif
+ rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ }
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
+ return (0);
+}
+
+/*
+ * TLP Timer, here we simply setup what segment we want to
+ * have the TLP expire on, the normal rack_output() will then
+ * send it out.
+ *
+ * We return 1, saying don't proceed with rack_output only
+ * when all timers have been stopped (destroyed PCB?).
+ */
+static int
+rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ /*
+ * Tail Loss Probe.
+ */
+ struct rack_sendmap *rsm = NULL;
+ struct socket *so;
+ uint32_t amm, old_prr_snd = 0;
+ uint32_t out, avail;
+
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
+ /* Its not time yet */
+ return (0);
+ }
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ return (1);
+ }
+ /*
+ * A TLP timer has expired. We have been idle for 2 rtts. So we now
+ * need to figure out how to force a full MSS segment out.
+ */
+ rack_log_to_event(rack, RACK_TO_FRM_TLP);
+ counter_u64_add(rack_tlp_tot, 1);
+ if (rack->r_state && (rack->r_state != tp->t_state))
+ rack_set_state(tp, rack);
+ so = tp->t_inpcb->inp_socket;
+ avail = sbavail(&so->so_snd);
+ out = tp->snd_max - tp->snd_una;
+ rack->rc_timer_up = 1;
+ /*
+ * If we are in recovery we can jazz out a segment if new data is
+ * present simply by setting rc_prr_sndcnt to a segment.
+ */
+ if ((avail > out) &&
+ ((rack_always_send_oldest == 0) || (TAILQ_EMPTY(&rack->r_ctl.rc_tmap)))) {
+ /* New data is available */
+ amm = avail - out;
+ if (amm > tp->t_maxseg) {
+ amm = tp->t_maxseg;
+ } else if ((amm < tp->t_maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
+ /* not enough to fill a MTU and no-delay is off */
+ goto need_retran;
+ }
+ if (IN_RECOVERY(tp->t_flags)) {
+ /* Unlikely */
+ old_prr_snd = rack->r_ctl.rc_prr_sndcnt;
+ if (out + amm <= tp->snd_wnd)
+ rack->r_ctl.rc_prr_sndcnt = amm;
+ else
+ goto need_retran;
+ } else {
+ /* Set the send-new override */
+ if (out + amm <= tp->snd_wnd)
+ rack->r_ctl.rc_tlp_new_data = amm;
+ else
+ goto need_retran;
+ }
+ rack->r_ctl.rc_tlp_seg_send_cnt = 0;
+ rack->r_ctl.rc_last_tlp_seq = tp->snd_max;
+ rack->r_ctl.rc_tlpsend = NULL;
+ counter_u64_add(rack_tlp_newdata, 1);
+ goto send;
+ }
+need_retran:
+ /*
+ * Ok we need to arrange the last un-acked segment to be re-sent, or
+ * optionally the first un-acked segment.
+ */
+ if (rack_always_send_oldest)
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ else {
+ rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
+ if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
+ rsm = rack_find_high_nonack(rack, rsm);
+ }
+ }
+ if (rsm == NULL) {
+ counter_u64_add(rack_tlp_does_nada, 1);
+#ifdef TCP_BLACKBOX
+ tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
+#endif
+ goto out;
+ }
+ if ((rsm->r_end - rsm->r_start) > tp->t_maxseg) {
+ /*
+ * We need to split this the last segment in two.
+ */
+ int32_t idx;
+ struct rack_sendmap *nrsm;
+
+ nrsm = rack_alloc(rack);
+ if (nrsm == NULL) {
+ /*
+ * No memory to split, we will just exit and punt
+ * off to the RXT timer.
+ */
+ counter_u64_add(rack_tlp_does_nada, 1);
+ goto out;
+ }
+ nrsm->r_start = (rsm->r_end - tp->t_maxseg);
+ nrsm->r_end = rsm->r_end;
+ nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
+ nrsm->r_flags = rsm->r_flags;
+ nrsm->r_sndcnt = rsm->r_sndcnt;
+ nrsm->r_rtr_bytes = 0;
+ rsm->r_end = nrsm->r_start;
+ for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
+ nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
+ }
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
+ nrsm->r_in_tmap = 1;
+ }
+ rsm->r_flags &= (~RACK_HAS_FIN);
+ rsm = nrsm;
+ }
+ rack->r_ctl.rc_tlpsend = rsm;
+ rack->r_ctl.rc_tlp_rtx_out = 1;
+ if (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) {
+ rack->r_ctl.rc_tlp_seg_send_cnt++;
+ tp->t_rxtshift++;
+ } else {
+ rack->r_ctl.rc_last_tlp_seq = rsm->r_start;
+ rack->r_ctl.rc_tlp_seg_send_cnt = 1;
+ }
+send:
+ rack->r_ctl.rc_tlp_send_cnt++;
+ if (rack->r_ctl.rc_tlp_send_cnt > rack_tlp_max_resend) {
+ /*
+ * Can't [re]/transmit a segment we have not heard from the
+ * peer in max times. We need the retransmit timer to take
+ * over.
+ */
+restore:
+ rack->r_ctl.rc_tlpsend = NULL;
+ if (rsm)
+ rsm->r_flags &= ~RACK_TLP;
+ rack->r_ctl.rc_prr_sndcnt = old_prr_snd;
+ counter_u64_add(rack_tlp_retran_fail, 1);
+ goto out;
+ } else if (rsm) {
+ rsm->r_flags |= RACK_TLP;
+ }
+ if (rsm && (rsm->r_start == rack->r_ctl.rc_last_tlp_seq) &&
+ (rack->r_ctl.rc_tlp_seg_send_cnt > rack_tlp_max_resend)) {
+ /*
+ * We don't want to send a single segment more than the max
+ * either.
+ */
+ goto restore;
+ }
+ rack->r_timer_override = 1;
+ rack->r_tlp_running = 1;
+ rack->rc_tlp_in_progress = 1;
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
+ return (0);
+out:
+ rack->rc_timer_up = 0;
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
+ return (0);
+}
+
+/*
+ * Delayed ack Timer, here we simply need to setup the
+ * ACK_NOW flag and remove the DELACK flag. From there
+ * the output routine will send the ack out.
+ *
+ * We only return 1, saying don't proceed, if all timers
+ * are stopped (destroyed PCB?).
+ */
+static int
+rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ rack_log_to_event(rack, RACK_TO_FRM_DELACK);
+ tp->t_flags &= ~TF_DELACK;
+ tp->t_flags |= TF_ACKNOW;
+ TCPSTAT_INC(tcps_delack);
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
+ return (0);
+}
+
+/*
+ * Persists timer, here we simply need to setup the
+ * FORCE-DATA flag the output routine will send
+ * the one byte send.
+ *
+ * We only return 1, saying don't proceed, if all timers
+ * are stopped (destroyed PCB?).
+ */
+static int
+rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ struct inpcb *inp;
+ int32_t retval = 0;
+
+ inp = tp->t_inpcb;
+
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ if (rack->rc_in_persist == 0)
+ return (0);
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(inp, ETIMEDOUT);
+ return (1);
+ }
+ KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
+ /*
+ * Persistence timer into zero window. Force a byte to be output, if
+ * possible.
+ */
+ TCPSTAT_INC(tcps_persisttimeo);
+ /*
+ * Hack: if the peer is dead/unreachable, we do not time out if the
+ * window is closed. After a full backoff, drop the connection if
+ * the idle time (no responses to probes) reaches the maximum
+ * backoff that we would use if retransmitting.
+ */
+ if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
+ (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
+ ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
+ TCPSTAT_INC(tcps_persistdrop);
+ retval = 1;
+ tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
+ goto out;
+ }
+ if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
+ tp->snd_una == tp->snd_max)
+ rack_exit_persist(tp, rack);
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
+ /*
+ * If the user has closed the socket then drop a persisting
+ * connection after a much reduced timeout.
+ */
+ if (tp->t_state > TCPS_CLOSE_WAIT &&
+ (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
+ retval = 1;
+ TCPSTAT_INC(tcps_persistdrop);
+ tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
+ goto out;
+ }
+ tp->t_flags |= TF_FORCEDATA;
+out:
+ rack_log_to_event(rack, RACK_TO_FRM_PERSIST);
+ return (retval);
+}
+
+/*
+ * If a keepalive goes off, we had no other timers
+ * happening. We always return 1 here since this
+ * routine either drops the connection or sends
+ * out a segment with respond.
+ */
+static int
+rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ struct tcptemp *t_template;
+ struct inpcb *inp;
+
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
+ inp = tp->t_inpcb;
+ rack_log_to_event(rack, RACK_TO_FRM_KEEP);
+ /*
+ * Keep-alive timer went off; send something or drop connection if
+ * idle for too long.
+ */
+ TCPSTAT_INC(tcps_keeptimeo);
+ if (tp->t_state < TCPS_ESTABLISHED)
+ goto dropit;
+ if ((tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
+ tp->t_state <= TCPS_CLOSING) {
+ if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
+ goto dropit;
+ /*
+ * Send a packet designed to force a response if the peer is
+ * up and reachable: either an ACK if the connection is
+ * still alive, or an RST if the peer has closed the
+ * connection due to timeout or reboot. Using sequence
+ * number tp->snd_una-1 causes the transmitted zero-length
+ * segment to lie outside the receive window; by the
+ * protocol spec, this requires the correspondent TCP to
+ * respond.
+ */
+ TCPSTAT_INC(tcps_keepprobe);
+ t_template = tcpip_maketemplate(inp);
+ if (t_template) {
+ tcp_respond(tp, t_template->tt_ipgen,
+ &t_template->tt_t, (struct mbuf *)NULL,
+ tp->rcv_nxt, tp->snd_una - 1, 0);
+ free(t_template, M_TEMP);
+ }
+ }
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, 0, 0, 0);
+ return (1);
+dropit:
+ TCPSTAT_INC(tcps_keepdrops);
+ tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
+ return (1);
+}
+
+/*
+ * Retransmit helper function, clear up all the ack
+ * flags and take care of important book keeping.
+ */
+static void
+rack_remxt_tmr(struct tcpcb *tp)
+{
+ /*
+ * The retransmit timer went off, all sack'd blocks must be
+ * un-acked.
+ */
+ struct rack_sendmap *rsm, *trsm = NULL;
+ struct tcp_rack *rack;
+ int32_t cnt = 0;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ rack_timer_cancel(tp, rack, tcp_ts_getticks(), __LINE__);
+ rack_log_to_event(rack, RACK_TO_FRM_TMR);
+ if (rack->r_state && (rack->r_state != tp->t_state))
+ rack_set_state(tp, rack);
+ /*
+ * Ideally we would like to be able to
+ * mark SACK-PASS on anything not acked here.
+ * However, if we do that we would burst out
+ * all that data 1ms apart. This would be unwise,
+ * so for now we will just let the normal rxt timer
+ * and tlp timer take care of it.
+ */
+ TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
+ if (rsm->r_flags & RACK_ACKED) {
+ cnt++;
+ rsm->r_sndcnt = 0;
+ if (rsm->r_in_tmap == 0) {
+ /* We must re-add it back to the tlist */
+ if (trsm == NULL) {
+ TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ } else {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
+ }
+ rsm->r_in_tmap = 1;
+ trsm = rsm;
+ }
+ }
+ rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
+ }
+ /* Clear the count (we just un-acked them) */
+ rack->r_ctl.rc_sacked = 0;
+ /* Clear the tlp rtx mark */
+ rack->r_ctl.rc_tlp_rtx_out = 0;
+ rack->r_ctl.rc_tlp_seg_send_cnt = 0;
+ rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ /* Setup so we send one segment */
+ if (rack->r_ctl.rc_prr_sndcnt < tp->t_maxseg)
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ rack->r_timer_override = 1;
+}
+
+/*
+ * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
+ * we will setup to retransmit the lowest seq number outstanding.
+ */
+static int
+rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
+{
+ int32_t rexmt;
+ struct inpcb *inp;
+ int32_t retval = 0;
+
+ inp = tp->t_inpcb;
+ if (tp->t_timers->tt_flags & TT_STOPPED) {
+ return (1);
+ }
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(inp, ETIMEDOUT);
+ return (1);
+ }
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
+ if (TCPS_HAVEESTABLISHED(tp->t_state) &&
+ (tp->snd_una == tp->snd_max)) {
+ /* Nothing outstanding .. nothing to do */
+ return (0);
+ }
+ /*
+ * Retransmission timer went off. Message has not been acked within
+ * retransmit interval. Back off to a longer retransmit interval
+ * and retransmit one segment.
+ */
+ if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
+ tp->t_rxtshift = TCP_MAXRXTSHIFT;
+ TCPSTAT_INC(tcps_timeoutdrop);
+ retval = 1;
+ tcp_set_inp_to_drop(rack->rc_inp,
+ (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
+ goto out;
+ }
+ rack_remxt_tmr(tp);
+ if (tp->t_state == TCPS_SYN_SENT) {
+ /*
+ * If the SYN was retransmitted, indicate CWND to be limited
+ * to 1 segment in cc_conn_init().
+ */
+ tp->snd_cwnd = 1;
+ } else if (tp->t_rxtshift == 1) {
+ /*
+ * first retransmit; record ssthresh and cwnd so they can be
+ * recovered if this turns out to be a "bad" retransmit. A
+ * retransmit is considered "bad" if an ACK for this segment
+ * is received within RTT/2 interval; the assumption here is
+ * that the ACK was already in flight. See "On Estimating
+ * End-to-End Network Path Properties" by Allman and Paxson
+ * for more details.
+ */
+ tp->snd_cwnd_prev = tp->snd_cwnd;
+ tp->snd_ssthresh_prev = tp->snd_ssthresh;
+ tp->snd_recover_prev = tp->snd_recover;
+ if (IN_FASTRECOVERY(tp->t_flags))
+ tp->t_flags |= TF_WASFRECOVERY;
+ else
+ tp->t_flags &= ~TF_WASFRECOVERY;
+ if (IN_CONGRECOVERY(tp->t_flags))
+ tp->t_flags |= TF_WASCRECOVERY;
+ else
+ tp->t_flags &= ~TF_WASCRECOVERY;
+ tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
+ tp->t_flags |= TF_PREVVALID;
+ } else
+ tp->t_flags &= ~TF_PREVVALID;
+ TCPSTAT_INC(tcps_rexmttimeo);
+ if ((tp->t_state == TCPS_SYN_SENT) ||
+ (tp->t_state == TCPS_SYN_RECEIVED))
+ rexmt = MSEC_2_TICKS(RACK_INITIAL_RTO * tcp_syn_backoff[tp->t_rxtshift]);
+ else
+ rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
+ TCPT_RANGESET(tp->t_rxtcur, rexmt,
+ max(MSEC_2_TICKS(rack_rto_min), rexmt),
+ MSEC_2_TICKS(rack_rto_max));
+ /*
+ * We enter the path for PLMTUD if connection is established or, if
+ * connection is FIN_WAIT_1 status, reason for the last is that if
+ * amount of data we send is very small, we could send it in couple
+ * of packets and process straight to FIN. In that case we won't
+ * catch ESTABLISHED state.
+ */
+ if (V_tcp_pmtud_blackhole_detect && (((tp->t_state == TCPS_ESTABLISHED))
+ || (tp->t_state == TCPS_FIN_WAIT_1))) {
+#ifdef INET6
+ int32_t isipv6;
+#endif
+
+ /*
+ * Idea here is that at each stage of mtu probe (usually,
+ * 1448 -> 1188 -> 524) should be given 2 chances to recover
+ * before further clamping down. 'tp->t_rxtshift % 2 == 0'
+ * should take care of that.
+ */
+ if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
+ (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
+ (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
+ tp->t_rxtshift % 2 == 0)) {
+ /*
+ * Enter Path MTU Black-hole Detection mechanism: -
+ * Disable Path MTU Discovery (IP "DF" bit). -
+ * Reduce MTU to lower value than what we negotiated
+ * with peer.
+ */
+ if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
+ /* Record that we may have found a black hole. */
+ tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
+ /* Keep track of previous MSS. */
+ tp->t_pmtud_saved_maxseg = tp->t_maxseg;
+ }
+
+ /*
+ * Reduce the MSS to blackhole value or to the
+ * default in an attempt to retransmit.
+ */
+#ifdef INET6
+ isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? 1 : 0;
+ if (isipv6 &&
+ tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
+ /* Use the sysctl tuneable blackhole MSS. */
+ tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
+ TCPSTAT_INC(tcps_pmtud_blackhole_activated);
+ } else if (isipv6) {
+ /* Use the default MSS. */
+ tp->t_maxseg = V_tcp_v6mssdflt;
+ /*
+ * Disable Path MTU Discovery when we switch
+ * to minmss.
+ */
+ tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
+ TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
+ }
+#endif
+#if defined(INET6) && defined(INET)
+ else
+#endif
+#ifdef INET
+ if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
+ /* Use the sysctl tuneable blackhole MSS. */
+ tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
+ TCPSTAT_INC(tcps_pmtud_blackhole_activated);
+ } else {
+ /* Use the default MSS. */
+ tp->t_maxseg = V_tcp_mssdflt;
+ /*
+ * Disable Path MTU Discovery when we switch
+ * to minmss.
+ */
+ tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
+ TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
+ }
+#endif
+ } else {
+ /*
+ * If further retransmissions are still unsuccessful
+ * with a lowered MTU, maybe this isn't a blackhole
+ * and we restore the previous MSS and blackhole
+ * detection flags. The limit '6' is determined by
+ * giving each probe stage (1448, 1188, 524) 2
+ * chances to recover.
+ */
+ if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
+ (tp->t_rxtshift >= 6)) {
+ tp->t_flags2 |= TF2_PLPMTU_PMTUD;
+ tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
+ tp->t_maxseg = tp->t_pmtud_saved_maxseg;
+ TCPSTAT_INC(tcps_pmtud_blackhole_failed);
+ }
+ }
+ }
+ /*
+ * Disable RFC1323 and SACK if we haven't got any response to our
+ * third SYN to work-around some broken terminal servers (most of
+ * which have hopefully been retired) that have bad VJ header
+ * compression code which trashes TCP segments containing
+ * unknown-to-them TCP options.
+ */
+ if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
+ (tp->t_rxtshift == 3))
+ tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
+ /*
+ * If we backed off this far, our srtt estimate is probably bogus.
+ * Clobber it so we'll take the next rtt measurement as our srtt;
+ * move the current srtt into rttvar to keep the current retransmit
+ * times until then.
+ */
+ if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
+#ifdef INET6
+ if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
+ in6_losing(tp->t_inpcb);
+ else
+#endif
+ in_losing(tp->t_inpcb);
+ tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
+ tp->t_srtt = 0;
+ }
+ if (rack_use_sack_filter)
+ sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
+ tp->snd_recover = tp->snd_max;
+ tp->t_flags |= TF_ACKNOW;
+ tp->t_rtttime = 0;
+ rack_cong_signal(tp, NULL, CC_RTO);
+out:
+ return (retval);
+}
+
+static int
+rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling)
+{
+ int32_t ret = 0;
+ int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
+
+ if (timers == 0) {
+ return (0);
+ }
+ if (tp->t_state == TCPS_LISTEN) {
+ /* no timers on listen sockets */
+ if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
+ return (0);
+ return (1);
+ }
+ if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
+ uint32_t left;
+
+ if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
+ ret = -1;
+ rack_log_to_processing(rack, cts, ret, 0);
+ return (0);
+ }
+ if (hpts_calling == 0) {
+ ret = -2;
+ rack_log_to_processing(rack, cts, ret, 0);
+ return (0);
+ }
+ /*
+ * Ok our timer went off early and we are not paced false
+ * alarm, go back to sleep.
+ */
+ ret = -3;
+ left = rack->r_ctl.rc_timer_exp - cts;
+ tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
+ rack_log_to_processing(rack, cts, ret, left);
+ rack->rc_last_pto_set = 0;
+ return (1);
+ }
+ rack->rc_tmr_stopped = 0;
+ rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
+ if (timers & PACE_TMR_DELACK) {
+ ret = rack_timeout_delack(tp, rack, cts);
+ } else if (timers & PACE_TMR_RACK) {
+ ret = rack_timeout_rack(tp, rack, cts);
+ } else if (timers & PACE_TMR_TLP) {
+ ret = rack_timeout_tlp(tp, rack, cts);
+ } else if (timers & PACE_TMR_RXT) {
+ ret = rack_timeout_rxt(tp, rack, cts);
+ } else if (timers & PACE_TMR_PERSIT) {
+ ret = rack_timeout_persist(tp, rack, cts);
+ } else if (timers & PACE_TMR_KEEP) {
+ ret = rack_timeout_keepalive(tp, rack, cts);
+ }
+ rack_log_to_processing(rack, cts, ret, timers);
+ return (ret);
+}
+
+static void
+rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
+{
+ uint8_t hpts_removed = 0;
+
+ if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
+ TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
+ tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
+ hpts_removed = 1;
+ }
+ if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
+ rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
+ if (rack->rc_inp->inp_in_hpts &&
+ ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
+ /*
+ * Canceling timer's when we have no output being
+ * paced. We also must remove ourselves from the
+ * hpts.
+ */
+ tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
+ hpts_removed = 1;
+ }
+ rack_log_to_cancel(rack, hpts_removed, line);
+ rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
+ }
+}
+
+static void
+rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
+{
+ return;
+}
+
+static int
+rack_stopall(struct tcpcb *tp)
+{
+ struct tcp_rack *rack;
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ rack->t_timers_stopped = 1;
+ return (0);
+}
+
+static void
+rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
+{
+ return;
+}
+
+static int
+rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
+{
+ return (0);
+}
+
+static void
+rack_stop_all_timers(struct tcpcb *tp)
+{
+ struct tcp_rack *rack;
+
+ /*
+ * Assure no timers are running.
+ */
+ if (tcp_timer_active(tp, TT_PERSIST)) {
+ /* We enter in persists, set the flag appropriately */
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ rack->rc_in_persist = 1;
+ }
+ tcp_timer_suspend(tp, TT_PERSIST);
+ tcp_timer_suspend(tp, TT_REXMT);
+ tcp_timer_suspend(tp, TT_KEEP);
+ tcp_timer_suspend(tp, TT_DELACK);
+}
+
+static void
+rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, uint32_t ts)
+{
+ int32_t idx;
+
+ rsm->r_rtr_cnt++;
+ rsm->r_sndcnt++;
+ if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
+ rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
+ rsm->r_flags |= RACK_OVERMAX;
+ }
+ if ((rsm->r_rtr_cnt > 1) && (rack->r_tlp_running == 0)) {
+ rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
+ rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
+ }
+ idx = rsm->r_rtr_cnt - 1;
+ rsm->r_tim_lastsent[idx] = ts;
+ if (rsm->r_flags & RACK_ACKED) {
+ /* Problably MTU discovery messing with us */
+ rsm->r_flags &= ~RACK_ACKED;
+ rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
+ }
+ if (rsm->r_in_tmap) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ }
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 1;
+ if (rsm->r_flags & RACK_SACK_PASSED) {
+ /* We have retransmitted due to the SACK pass */
+ rsm->r_flags &= ~RACK_SACK_PASSED;
+ rsm->r_flags |= RACK_WAS_SACKPASS;
+ }
+ /* Update memory for next rtr */
+ rack->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
+}
+
+
+static uint32_t
+rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp)
+{
+ /*
+ * We (re-)transmitted starting at rsm->r_start for some length
+ * (possibly less than r_end.
+ */
+ struct rack_sendmap *nrsm;
+ uint32_t c_end;
+ int32_t len;
+ int32_t idx;
+
+ len = *lenp;
+ c_end = rsm->r_start + len;
+ if (SEQ_GEQ(c_end, rsm->r_end)) {
+ /*
+ * We retransmitted the whole piece or more than the whole
+ * slopping into the next rsm.
+ */
+ rack_update_rsm(tp, rack, rsm, ts);
+ if (c_end == rsm->r_end) {
+ *lenp = 0;
+ return (0);
+ } else {
+ int32_t act_len;
+
+ /* Hangs over the end return whats left */
+ act_len = rsm->r_end - rsm->r_start;
+ *lenp = (len - act_len);
+ return (rsm->r_end);
+ }
+ /* We don't get out of this block. */
+ }
+ /*
+ * Here we retransmitted less than the whole thing which means we
+ * have to split this into what was transmitted and what was not.
+ */
+ nrsm = rack_alloc(rack);
+ if (nrsm == NULL) {
+ /*
+ * We can't get memory, so lets not proceed.
+ */
+ *lenp = 0;
+ return (0);
+ }
+ /*
+ * So here we are going to take the original rsm and make it what we
+ * retransmitted. nrsm will be the tail portion we did not
+ * retransmit. For example say the chunk was 1, 11 (10 bytes). And
+ * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
+ * 1, 6 and the new piece will be 6, 11.
+ */
+ nrsm->r_start = c_end;
+ nrsm->r_end = rsm->r_end;
+ nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
+ nrsm->r_flags = rsm->r_flags;
+ nrsm->r_sndcnt = rsm->r_sndcnt;
+ nrsm->r_rtr_bytes = 0;
+ rsm->r_end = c_end;
+ for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
+ nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
+ }
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
+ nrsm->r_in_tmap = 1;
+ }
+ rsm->r_flags &= (~RACK_HAS_FIN);
+ rack_update_rsm(tp, rack, rsm, ts);
+ *lenp = 0;
+ return (0);
+}
+
+
+static void
+rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
+ uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
+ uint8_t pass, struct rack_sendmap *hintrsm)
+{
+ struct tcp_rack *rack;
+ struct rack_sendmap *rsm, *nrsm;
+ register uint32_t snd_max, snd_una;
+ int32_t idx;
+
+ /*
+ * Add to the RACK log of packets in flight or retransmitted. If
+ * there is a TS option we will use the TS echoed, if not we will
+ * grab a TS.
+ *
+ * Retransmissions will increment the count and move the ts to its
+ * proper place. Note that if options do not include TS's then we
+ * won't be able to effectively use the ACK for an RTT on a retran.
+ *
+ * Notes about r_start and r_end. Lets consider a send starting at
+ * sequence 1 for 10 bytes. In such an example the r_start would be
+ * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
+ * This means that r_end is actually the first sequence for the next
+ * slot (11).
+ *
+ */
+ /*
+ * If err is set what do we do XXXrrs? should we not add the thing?
+ * -- i.e. return if err != 0 or should we pretend we sent it? --
+ * i.e. proceed with add ** do this for now.
+ */
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ if (err)
+ /*
+ * We don't log errors -- we could but snd_max does not
+ * advance in this case either.
+ */
+ return;
+
+ if (th_flags & TH_RST) {
+ /*
+ * We don't log resets and we return immediately from
+ * sending
+ */
+ return;
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ snd_una = tp->snd_una;
+ if (SEQ_LEQ((seq_out + len), snd_una)) {
+ /* Are sending an old segment to induce an ack (keep-alive)? */
+ return;
+ }
+ if (SEQ_LT(seq_out, snd_una)) {
+ /* huh? should we panic? */
+ uint32_t end;
+
+ end = seq_out + len;
+ seq_out = snd_una;
+ len = end - seq_out;
+ }
+ snd_max = tp->snd_max;
+ if (th_flags & (TH_SYN | TH_FIN)) {
+ /*
+ * The call to rack_log_output is made before bumping
+ * snd_max. This means we can record one extra byte on a SYN
+ * or FIN if seq_out is adding more on and a FIN is present
+ * (and we are not resending).
+ */
+ if (th_flags & TH_SYN)
+ len++;
+ if (th_flags & TH_FIN)
+ len++;
+ if (SEQ_LT(snd_max, tp->snd_nxt)) {
+ /*
+ * The add/update as not been done for the FIN/SYN
+ * yet.
+ */
+ snd_max = tp->snd_nxt;
+ }
+ }
+ if (len == 0) {
+ /* We don't log zero window probes */
+ return;
+ }
+ rack->r_ctl.rc_time_last_sent = ts;
+ if (IN_RECOVERY(tp->t_flags)) {
+ rack->r_ctl.rc_prr_out += len;
+ }
+ /* First question is it a retransmission? */
+ if (seq_out == snd_max) {
+again:
+ rsm = rack_alloc(rack);
+ if (rsm == NULL) {
+ /*
+ * Hmm out of memory and the tcb got destroyed while
+ * we tried to wait.
+ */
+#ifdef INVARIANTS
+ panic("Out of memory when we should not be rack:%p", rack);
+#endif
+ return;
+ }
+ if (th_flags & TH_FIN) {
+ rsm->r_flags = RACK_HAS_FIN;
+ } else {
+ rsm->r_flags = 0;
+ }
+ rsm->r_tim_lastsent[0] = ts;
+ rsm->r_rtr_cnt = 1;
+ rsm->r_rtr_bytes = 0;
+ rsm->r_start = seq_out;
+ rsm->r_end = rsm->r_start + len;
+ rsm->r_sndcnt = 0;
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_map, rsm, r_next);
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 1;
+ return;
+ }
+ /*
+ * If we reach here its a retransmission and we need to find it.
+ */
+more:
+ if (hintrsm && (hintrsm->r_start == seq_out)) {
+ rsm = hintrsm;
+ hintrsm = NULL;
+ } else if (rack->r_ctl.rc_next) {
+ /* We have a hint from a previous run */
+ rsm = rack->r_ctl.rc_next;
+ } else {
+ /* No hints sorry */
+ rsm = NULL;
+ }
+ if ((rsm) && (rsm->r_start == seq_out)) {
+ /*
+ * We used rc_next or hintrsm to retransmit, hopefully the
+ * likely case.
+ */
+ seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
+ if (len == 0) {
+ return;
+ } else {
+ goto more;
+ }
+ }
+ /* Ok it was not the last pointer go through it the hard way. */
+ TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
+ if (rsm->r_start == seq_out) {
+ seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
+ rack->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
+ if (len == 0) {
+ return;
+ } else {
+ continue;
+ }
+ }
+ if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
+ /* Transmitted within this piece */
+ /*
+ * Ok we must split off the front and then let the
+ * update do the rest
+ */
+ nrsm = rack_alloc(rack);
+ if (nrsm == NULL) {
+#ifdef INVARIANTS
+ panic("Ran out of memory that was preallocated? rack:%p", rack);
+#endif
+ rack_update_rsm(tp, rack, rsm, ts);
+ return;
+ }
+ /*
+ * copy rsm to nrsm and then trim the front of rsm
+ * to not include this part.
+ */
+ nrsm->r_start = seq_out;
+ nrsm->r_end = rsm->r_end;
+ nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
+ nrsm->r_flags = rsm->r_flags;
+ nrsm->r_sndcnt = rsm->r_sndcnt;
+ nrsm->r_rtr_bytes = 0;
+ for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
+ nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
+ }
+ rsm->r_end = nrsm->r_start;
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
+ nrsm->r_in_tmap = 1;
+ }
+ rsm->r_flags &= (~RACK_HAS_FIN);
+ seq_out = rack_update_entry(tp, rack, nrsm, ts, &len);
+ if (len == 0) {
+ return;
+ }
+ }
+ }
+ /*
+ * Hmm not found in map did they retransmit both old and on into the
+ * new?
+ */
+ if (seq_out == tp->snd_max) {
+ goto again;
+ } else if (SEQ_LT(seq_out, tp->snd_max)) {
+#ifdef INVARIANTS
+ printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
+ seq_out, len, tp->snd_una, tp->snd_max);
+ printf("Starting Dump of all rack entries\n");
+ TAILQ_FOREACH(rsm, &rack->r_ctl.rc_map, r_next) {
+ printf("rsm:%p start:%u end:%u\n",
+ rsm, rsm->r_start, rsm->r_end);
+ }
+ printf("Dump complete\n");
+ panic("seq_out not found rack:%p tp:%p",
+ rack, tp);
+#endif
+ } else {
+#ifdef INVARIANTS
+ /*
+ * Hmm beyond sndmax? (only if we are using the new rtt-pack
+ * flag)
+ */
+ panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
+ seq_out, len, tp->snd_max, tp);
+#endif
+ }
+}
+
+/*
+ * Record one of the RTT updates from an ack into
+ * our sample structure.
+ */
+static void
+tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt)
+{
+ if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
+ (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
+ rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
+ }
+ if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
+ (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
+ rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
+ }
+ rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
+ rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
+ rack->r_ctl.rack_rs.rs_rtt_cnt++;
+}
+
+/*
+ * Collect new round-trip time estimate
+ * and update averages and current timeout.
+ */
+static void
+tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
+{
+ int32_t delta;
+ uint32_t o_srtt, o_var;
+ int32_t rtt;
+
+ if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
+ /* No valid sample */
+ return;
+ if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
+ /* We are to use the lowest RTT seen in a single ack */
+ rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
+ } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
+ /* We are to use the highest RTT seen in a single ack */
+ rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
+ } else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
+ /* We are to use the average RTT seen in a single ack */
+ rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
+ (uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
+ } else {
+#ifdef INVARIANTS
+ panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
+#endif
+ return;
+ }
+ if (rtt == 0)
+ rtt = 1;
+ rack_log_rtt_sample(rack, rtt);
+ o_srtt = tp->t_srtt;
+ o_var = tp->t_rttvar;
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (tp->t_srtt != 0) {
+ /*
+ * srtt is stored as fixed point with 5 bits after the
+ * binary point (i.e., scaled by 8). The following magic is
+ * equivalent to the smoothing algorithm in rfc793 with an
+ * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
+ * Adjust rtt to origin 0.
+ */
+ delta = ((rtt - 1) << TCP_DELTA_SHIFT)
+ - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
+
+ tp->t_srtt += delta;
+ if (tp->t_srtt <= 0)
+ tp->t_srtt = 1;
+
+ /*
+ * We accumulate a smoothed rtt variance (actually, a
+ * smoothed mean difference), then set the retransmit timer
+ * to smoothed rtt + 4 times the smoothed variance. rttvar
+ * is stored as fixed point with 4 bits after the binary
+ * point (scaled by 16). The following is equivalent to
+ * rfc793 smoothing with an alpha of .75 (rttvar =
+ * rttvar*3/4 + |delta| / 4). This replaces rfc793's
+ * wired-in beta.
+ */
+ if (delta < 0)
+ delta = -delta;
+ delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
+ tp->t_rttvar += delta;
+ if (tp->t_rttvar <= 0)
+ tp->t_rttvar = 1;
+ if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
+ tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
+ } else {
+ /*
+ * No rtt measurement yet - use the unsmoothed rtt. Set the
+ * variance to half the rtt (so our first retransmit happens
+ * at 3*rtt).
+ */
+ tp->t_srtt = rtt << TCP_RTT_SHIFT;
+ tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
+ tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
+ }
+ TCPSTAT_INC(tcps_rttupdated);
+ rack_log_rtt_upd(tp, rack, rtt, o_srtt, o_var);
+ tp->t_rttupdated++;
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
+#endif
+ tp->t_rxtshift = 0;
+
+ /*
+ * the retransmit should happen at rtt + 4 * rttvar. Because of the
+ * way we do the smoothing, srtt and rttvar will each average +1/2
+ * tick of bias. When we compute the retransmit timer, we want 1/2
+ * tick of rounding and 1 extra tick because of +-1/2 tick
+ * uncertainty in the firing of the timer. The bias will give us
+ * exactly the 1.5 tick we need. But, because the bias is
+ * statistical, we have to test that we don't drop below the minimum
+ * feasible timer (which is 2 ticks).
+ */
+ TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
+ max(MSEC_2_TICKS(rack_rto_min), rtt + 2), MSEC_2_TICKS(rack_rto_max));
+ tp->t_softerror = 0;
+}
+
+static void
+rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
+ uint32_t t, uint32_t cts)
+{
+ /*
+ * For this RSM, we acknowledged the data from a previous
+ * transmission, not the last one we made. This means we did a false
+ * retransmit.
+ */
+ struct tcp_rack *rack;
+
+ if (rsm->r_flags & RACK_HAS_FIN) {
+ /*
+ * The sending of the FIN often is multiple sent when we
+ * have everything outstanding ack'd. We ignore this case
+ * since its over now.
+ */
+ return;
+ }
+ if (rsm->r_flags & RACK_TLP) {
+ /*
+ * We expect TLP's to have this occur.
+ */
+ return;
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ /* should we undo cc changes and exit recovery? */
+ if (IN_RECOVERY(tp->t_flags)) {
+ if (rack->r_ctl.rc_rsm_start == rsm->r_start) {
+ /*
+ * Undo what we ratched down and exit recovery if
+ * possible
+ */
+ EXIT_RECOVERY(tp->t_flags);
+ tp->snd_recover = tp->snd_una;
+ if (rack->r_ctl.rc_cwnd_at > tp->snd_cwnd)
+ tp->snd_cwnd = rack->r_ctl.rc_cwnd_at;
+ if (rack->r_ctl.rc_ssthresh_at > tp->snd_ssthresh)
+ tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at;
+ }
+ }
+ if (rsm->r_flags & RACK_WAS_SACKPASS) {
+ /*
+ * We retransmitted based on a sack and the earlier
+ * retransmission ack'd it - re-ordering is occuring.
+ */
+ counter_u64_add(rack_reorder_seen, 1);
+ rack->r_ctl.rc_reorder_ts = cts;
+ }
+ counter_u64_add(rack_badfr, 1);
+ counter_u64_add(rack_badfr_bytes, (rsm->r_end - rsm->r_start));
+}
+
+
+static int
+rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
+ struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type)
+{
+ int32_t i;
+ uint32_t t;
+
+ if (rsm->r_flags & RACK_ACKED)
+ /* Already done */
+ return (0);
+
+
+ if ((rsm->r_rtr_cnt == 1) ||
+ ((ack_type == CUM_ACKED) &&
+ (to->to_flags & TOF_TS) &&
+ (to->to_tsecr) &&
+ (rsm->r_tim_lastsent[rsm->r_rtr_cnt - 1] == to->to_tsecr))
+ ) {
+ /*
+ * We will only find a matching timestamp if its cum-acked.
+ * But if its only one retransmission its for-sure matching
+ * :-)
+ */
+ t = cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
+ if ((int)t <= 0)
+ t = 1;
+ if (!tp->t_rttlow || tp->t_rttlow > t)
+ tp->t_rttlow = t;
+ if (!rack->r_ctl.rc_rack_min_rtt ||
+ SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
+ rack->r_ctl.rc_rack_min_rtt = t;
+ if (rack->r_ctl.rc_rack_min_rtt == 0) {
+ rack->r_ctl.rc_rack_min_rtt = 1;
+ }
+ }
+ tcp_rack_xmit_timer(rack, TCP_TS_TO_TICKS(t) + 1);
+ if ((rsm->r_flags & RACK_TLP) &&
+ (!IN_RECOVERY(tp->t_flags))) {
+ /* Segment was a TLP and our retrans matched */
+ if (rack->r_ctl.rc_tlp_cwnd_reduce) {
+ rack->r_ctl.rc_rsm_start = tp->snd_max;
+ rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
+ rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
+ rack_cong_signal(tp, NULL, CC_NDUPACK);
+ /*
+ * When we enter recovery we need to assure
+ * we send one packet.
+ */
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ } else
+ rack->r_ctl.rc_tlp_rtx_out = 0;
+ }
+ if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
+ /* New more recent rack_tmit_time */
+ rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
+ rack->rc_rack_rtt = t;
+ }
+ return (1);
+ }
+ /*
+ * We clear the soft/rxtshift since we got an ack.
+ * There is no assurance we will call the commit() function
+ * so we need to clear these to avoid incorrect handling.
+ */
+ tp->t_rxtshift = 0;
+ tp->t_softerror = 0;
+ if ((to->to_flags & TOF_TS) &&
+ (ack_type == CUM_ACKED) &&
+ (to->to_tsecr) &&
+ ((rsm->r_flags & (RACK_DEFERRED | RACK_OVERMAX)) == 0)) {
+ /*
+ * Now which timestamp does it match? In this block the ACK
+ * must be coming from a previous transmission.
+ */
+ for (i = 0; i < rsm->r_rtr_cnt; i++) {
+ if (rsm->r_tim_lastsent[i] == to->to_tsecr) {
+ t = cts - rsm->r_tim_lastsent[i];
+ if ((int)t <= 0)
+ t = 1;
+ if ((i + 1) < rsm->r_rtr_cnt) {
+ /* Likely */
+ rack_earlier_retran(tp, rsm, t, cts);
+ }
+ if (!tp->t_rttlow || tp->t_rttlow > t)
+ tp->t_rttlow = t;
+ if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
+ rack->r_ctl.rc_rack_min_rtt = t;
+ if (rack->r_ctl.rc_rack_min_rtt == 0) {
+ rack->r_ctl.rc_rack_min_rtt = 1;
+ }
+ }
+ /*
+ * Note the following calls to
+ * tcp_rack_xmit_timer() are being commented
+ * out for now. They give us no more accuracy
+ * and often lead to a wrong choice. We have
+ * enough samples that have not been
+ * retransmitted. I leave the commented out
+ * code in here in case in the future we
+ * decide to add it back (though I can't forsee
+ * doing that). That way we will easily see
+ * where they need to be placed.
+ */
+ if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
+ rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
+ /* New more recent rack_tmit_time */
+ rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
+ rack->rc_rack_rtt = t;
+ }
+ return (1);
+ }
+ }
+ goto ts_not_found;
+ } else {
+ /*
+ * Ok its a SACK block that we retransmitted. or a windows
+ * machine without timestamps. We can tell nothing from the
+ * time-stamp since its not there or the time the peer last
+ * recieved a segment that moved forward its cum-ack point.
+ */
+ts_not_found:
+ i = rsm->r_rtr_cnt - 1;
+ t = cts - rsm->r_tim_lastsent[i];
+ if ((int)t <= 0)
+ t = 1;
+ if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
+ /*
+ * We retransmitted and the ack came back in less
+ * than the smallest rtt we have observed. We most
+ * likey did an improper retransmit as outlined in
+ * 4.2 Step 3 point 2 in the rack-draft.
+ */
+ i = rsm->r_rtr_cnt - 2;
+ t = cts - rsm->r_tim_lastsent[i];
+ rack_earlier_retran(tp, rsm, t, cts);
+ } else if (rack->r_ctl.rc_rack_min_rtt) {
+ /*
+ * We retransmitted it and the retransmit did the
+ * job.
+ */
+ if (!rack->r_ctl.rc_rack_min_rtt ||
+ SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
+ rack->r_ctl.rc_rack_min_rtt = t;
+ if (rack->r_ctl.rc_rack_min_rtt == 0) {
+ rack->r_ctl.rc_rack_min_rtt = 1;
+ }
+ }
+ if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[i])) {
+ /* New more recent rack_tmit_time */
+ rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[i];
+ rack->rc_rack_rtt = t;
+ }
+ return (1);
+ }
+ }
+ return (0);
+}
+
+/*
+ * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
+ */
+static void
+rack_log_sack_passed(struct tcpcb *tp,
+ struct tcp_rack *rack, struct rack_sendmap *rsm)
+{
+ struct rack_sendmap *nrsm;
+ uint32_t ts;
+ int32_t idx;
+
+ idx = rsm->r_rtr_cnt - 1;
+ ts = rsm->r_tim_lastsent[idx];
+ nrsm = rsm;
+ TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
+ rack_head, r_tnext) {
+ if (nrsm == rsm) {
+ /* Skip orginal segment he is acked */
+ continue;
+ }
+ if (nrsm->r_flags & RACK_ACKED) {
+ /* Skip ack'd segments */
+ continue;
+ }
+ idx = nrsm->r_rtr_cnt - 1;
+ if (ts == nrsm->r_tim_lastsent[idx]) {
+ /*
+ * For this case lets use seq no, if we sent in a
+ * big block (TSO) we would have a bunch of segments
+ * sent at the same time.
+ *
+ * We would only get a report if its SEQ is earlier.
+ * If we have done multiple retransmits the times
+ * would not be equal.
+ */
+ if (SEQ_LT(nrsm->r_start, rsm->r_start)) {
+ nrsm->r_flags |= RACK_SACK_PASSED;
+ nrsm->r_flags &= ~RACK_WAS_SACKPASS;
+ }
+ } else {
+ /*
+ * Here they were sent at different times, not a big
+ * block. Since we transmitted this one later and
+ * see it sack'd then this must also be missing (or
+ * we would have gotten a sack block for it)
+ */
+ nrsm->r_flags |= RACK_SACK_PASSED;
+ nrsm->r_flags &= ~RACK_WAS_SACKPASS;
+ }
+ }
+}
+
+static uint32_t
+rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
+ struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts)
+{
+ int32_t idx;
+ int32_t times = 0;
+ uint32_t start, end, changed = 0;
+ struct rack_sendmap *rsm, *nrsm;
+ int32_t used_ref = 1;
+
+ start = sack->start;
+ end = sack->end;
+ rsm = *prsm;
+ if (rsm && SEQ_LT(start, rsm->r_start)) {
+ TAILQ_FOREACH_REVERSE_FROM(rsm, &rack->r_ctl.rc_map, rack_head, r_next) {
+ if (SEQ_GEQ(start, rsm->r_start) &&
+ SEQ_LT(start, rsm->r_end)) {
+ goto do_rest_ofb;
+ }
+ }
+ }
+ if (rsm == NULL) {
+start_at_beginning:
+ rsm = NULL;
+ used_ref = 0;
+ }
+ /* First lets locate the block where this guy is */
+ TAILQ_FOREACH_FROM(rsm, &rack->r_ctl.rc_map, r_next) {
+ if (SEQ_GEQ(start, rsm->r_start) &&
+ SEQ_LT(start, rsm->r_end)) {
+ break;
+ }
+ }
+do_rest_ofb:
+ if (rsm == NULL) {
+ /*
+ * This happens when we get duplicate sack blocks with the
+ * same end. For example SACK 4: 100 SACK 3: 100 The sort
+ * will not change there location so we would just start at
+ * the end of the first one and get lost.
+ */
+ if (tp->t_flags & TF_SENTFIN) {
+ /*
+ * Check to see if we have not logged the FIN that
+ * went out.
+ */
+ nrsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
+ if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
+ /*
+ * Ok we did not get the FIN logged.
+ */
+ nrsm->r_end++;
+ rsm = nrsm;
+ goto do_rest_ofb;
+ }
+ }
+ if (times == 1) {
+#ifdef INVARIANTS
+ panic("tp:%p rack:%p sack:%p to:%p prsm:%p",
+ tp, rack, sack, to, prsm);
+#else
+ goto out;
+#endif
+ }
+ times++;
+ counter_u64_add(rack_sack_proc_restart, 1);
+ goto start_at_beginning;
+ }
+ /* Ok we have an ACK for some piece of rsm */
+ if (rsm->r_start != start) {
+ /*
+ * Need to split this in two pieces the before and after.
+ */
+ nrsm = rack_alloc(rack);
+ if (nrsm == NULL) {
+ /*
+ * failed XXXrrs what can we do but loose the sack
+ * info?
+ */
+ goto out;
+ }
+ nrsm->r_start = start;
+ nrsm->r_rtr_bytes = 0;
+ nrsm->r_end = rsm->r_end;
+ nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
+ nrsm->r_flags = rsm->r_flags;
+ nrsm->r_sndcnt = rsm->r_sndcnt;
+ for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
+ nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
+ }
+ rsm->r_end = nrsm->r_start;
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
+ nrsm->r_in_tmap = 1;
+ }
+ rsm->r_flags &= (~RACK_HAS_FIN);
+ rsm = nrsm;
+ }
+ if (SEQ_GEQ(end, rsm->r_end)) {
+ /*
+ * The end of this block is either beyond this guy or right
+ * at this guy.
+ */
+
+ if ((rsm->r_flags & RACK_ACKED) == 0) {
+ rack_update_rtt(tp, rack, rsm, to, cts, SACKED);
+ changed += (rsm->r_end - rsm->r_start);
+ rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
+ rack_log_sack_passed(tp, rack, rsm);
+ /* Is Reordering occuring? */
+ if (rsm->r_flags & RACK_SACK_PASSED) {
+ counter_u64_add(rack_reorder_seen, 1);
+ rack->r_ctl.rc_reorder_ts = cts;
+ }
+ rsm->r_flags |= RACK_ACKED;
+ rsm->r_flags &= ~RACK_TLP;
+ if (rsm->r_in_tmap) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 0;
+ }
+ }
+ if (end == rsm->r_end) {
+ /* This block only - done */
+ goto out;
+ }
+ /* There is more not coverend by this rsm move on */
+ start = rsm->r_end;
+ nrsm = TAILQ_NEXT(rsm, r_next);
+ rsm = nrsm;
+ times = 0;
+ goto do_rest_ofb;
+ }
+ /* Ok we need to split off this one at the tail */
+ nrsm = rack_alloc(rack);
+ if (nrsm == NULL) {
+ /* failed rrs what can we do but loose the sack info? */
+ goto out;
+ }
+ /* Clone it */
+ nrsm->r_start = end;
+ nrsm->r_end = rsm->r_end;
+ nrsm->r_rtr_bytes = 0;
+ nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
+ nrsm->r_flags = rsm->r_flags;
+ nrsm->r_sndcnt = rsm->r_sndcnt;
+ for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
+ nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
+ }
+ /* The sack block does not cover this guy fully */
+ rsm->r_flags &= (~RACK_HAS_FIN);
+ rsm->r_end = end;
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_map, rsm, nrsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
+ nrsm->r_in_tmap = 1;
+ }
+ if (rsm->r_flags & RACK_ACKED) {
+ /* Been here done that */
+ goto out;
+ }
+ rack_update_rtt(tp, rack, rsm, to, cts, SACKED);
+ changed += (rsm->r_end - rsm->r_start);
+ rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
+ rack_log_sack_passed(tp, rack, rsm);
+ /* Is Reordering occuring? */
+ if (rsm->r_flags & RACK_SACK_PASSED) {
+ counter_u64_add(rack_reorder_seen, 1);
+ rack->r_ctl.rc_reorder_ts = cts;
+ }
+ rsm->r_flags |= RACK_ACKED;
+ rsm->r_flags &= ~RACK_TLP;
+ if (rsm->r_in_tmap) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 0;
+ }
+out:
+ if (used_ref == 0) {
+ counter_u64_add(rack_sack_proc_all, 1);
+ } else {
+ counter_u64_add(rack_sack_proc_short, 1);
+ }
+ /* Save off where we last were */
+ if (rsm)
+ rack->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
+ else
+ rack->r_ctl.rc_sacklast = NULL;
+ *prsm = rsm;
+ return (changed);
+}
+
+static void inline
+rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
+{
+ struct rack_sendmap *tmap;
+
+ tmap = NULL;
+ while (rsm && (rsm->r_flags & RACK_ACKED)) {
+ /* Its no longer sacked, mark it so */
+ rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
+#ifdef INVARIANTS
+ if (rsm->r_in_tmap) {
+ panic("rack:%p rsm:%p flags:0x%x in tmap?",
+ rack, rsm, rsm->r_flags);
+ }
+#endif
+ rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
+ /* Rebuild it into our tmap */
+ if (tmap == NULL) {
+ TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ tmap = rsm;
+ } else {
+ TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
+ tmap = rsm;
+ }
+ tmap->r_in_tmap = 1;
+ rsm = TAILQ_NEXT(rsm, r_next);
+ }
+ /*
+ * Now lets possibly clear the sack filter so we start
+ * recognizing sacks that cover this area.
+ */
+ if (rack_use_sack_filter)
+ sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
+
+}
+
+static void
+rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th)
+{
+ uint32_t changed, last_seq, entered_recovery = 0;
+ struct tcp_rack *rack;
+ struct rack_sendmap *rsm;
+ struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
+ register uint32_t th_ack;
+ int32_t i, j, k, num_sack_blks = 0;
+ uint32_t cts, acked, ack_point, sack_changed = 0;
+
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ if (th->th_flags & TH_RST) {
+ /* We don't log resets */
+ return;
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ cts = tcp_ts_getticks();
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ changed = 0;
+ th_ack = th->th_ack;
+
+ if (SEQ_GT(th_ack, tp->snd_una)) {
+ rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
+ tp->t_acktime = ticks;
+ }
+ if (rsm && SEQ_GT(th_ack, rsm->r_start))
+ changed = th_ack - rsm->r_start;
+ if (changed) {
+ /*
+ * The ACK point is advancing to th_ack, we must drop off
+ * the packets in the rack log and calculate any eligble
+ * RTT's.
+ */
+ rack->r_wanted_output++;
+more:
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ if (rsm == NULL) {
+ if ((th_ack - 1) == tp->iss) {
+ /*
+ * For the SYN incoming case we will not
+ * have called tcp_output for the sending of
+ * the SYN, so there will be no map. All
+ * other cases should probably be a panic.
+ */
+ goto proc_sack;
+ }
+ if (tp->t_flags & TF_SENTFIN) {
+ /* if we send a FIN we will not hav a map */
+ goto proc_sack;
+ }
+#ifdef INVARIANTS
+ panic("No rack map tp:%p for th:%p state:%d rack:%p snd_una:%u snd_max:%u snd_nxt:%u chg:%d\n",
+ tp,
+ th, tp->t_state, rack,
+ tp->snd_una, tp->snd_max, tp->snd_nxt, changed);
+#endif
+ goto proc_sack;
+ }
+ if (SEQ_LT(th_ack, rsm->r_start)) {
+ /* Huh map is missing this */
+#ifdef INVARIANTS
+ printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
+ rsm->r_start,
+ th_ack, tp->t_state, rack->r_state);
+#endif
+ goto proc_sack;
+ }
+ rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED);
+ /* Now do we consume the whole thing? */
+ if (SEQ_GEQ(th_ack, rsm->r_end)) {
+ /* Its all consumed. */
+ uint32_t left;
+
+ rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
+ rsm->r_rtr_bytes = 0;
+ TAILQ_REMOVE(&rack->r_ctl.rc_map, rsm, r_next);
+ if (rsm->r_in_tmap) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 0;
+ }
+ if (rack->r_ctl.rc_next == rsm) {
+ /* scoot along the marker */
+ rack->r_ctl.rc_next = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ }
+ if (rsm->r_flags & RACK_ACKED) {
+ /*
+ * It was acked on the scoreboard -- remove
+ * it from total
+ */
+ rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
+ } else if (rsm->r_flags & RACK_SACK_PASSED) {
+ /*
+ * There are acked segments ACKED on the
+ * scoreboard further up. We are seeing
+ * reordering.
+ */
+ counter_u64_add(rack_reorder_seen, 1);
+ rsm->r_flags |= RACK_ACKED;
+ rack->r_ctl.rc_reorder_ts = cts;
+ }
+ left = th_ack - rsm->r_end;
+ if (rsm->r_rtr_cnt > 1) {
+ /*
+ * Technically we should make r_rtr_cnt be
+ * monotonicly increasing and just mod it to
+ * the timestamp it is replacing.. that way
+ * we would have the last 3 retransmits. Now
+ * rc_loss_count will be wrong if we
+ * retransmit something more than 2 times in
+ * recovery :(
+ */
+ rack->r_ctl.rc_loss_count += (rsm->r_rtr_cnt - 1);
+ }
+ /* Free back to zone */
+ rack_free(rack, rsm);
+ if (left) {
+ goto more;
+ }
+ goto proc_sack;
+ }
+ if (rsm->r_flags & RACK_ACKED) {
+ /*
+ * It was acked on the scoreboard -- remove it from
+ * total for the part being cum-acked.
+ */
+ rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
+ }
+ rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
+ rsm->r_rtr_bytes = 0;
+ rsm->r_start = th_ack;
+ }
+proc_sack:
+ /* Check for reneging */
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
+ /*
+ * The peer has moved snd_una up to
+ * the edge of this send, i.e. one
+ * that it had previously acked. The only
+ * way that can be true if the peer threw
+ * away data (space issues) that it had
+ * previously sacked (else it would have
+ * given us snd_una up to (rsm->r_end).
+ * We need to undo the acked markings here.
+ *
+ * Note we have to look to make sure th_ack is
+ * our rsm->r_start in case we get an old ack
+ * where th_ack is behind snd_una.
+ */
+ rack_peer_reneges(rack, rsm, th->th_ack);
+ }
+ if ((to->to_flags & TOF_SACK) == 0) {
+ /* We are done nothing left to log */
+ goto out;
+ }
+ rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_map, rack_sendmap, r_next);
+ if (rsm) {
+ last_seq = rsm->r_end;
+ } else {
+ last_seq = tp->snd_max;
+ }
+ /* Sack block processing */
+ if (SEQ_GT(th_ack, tp->snd_una))
+ ack_point = th_ack;
+ else
+ ack_point = tp->snd_una;
+ for (i = 0; i < to->to_nsacks; i++) {
+ bcopy((to->to_sacks + i * TCPOLEN_SACK),
+ &sack, sizeof(sack));
+ sack.start = ntohl(sack.start);
+ sack.end = ntohl(sack.end);
+ if (SEQ_GT(sack.end, sack.start) &&
+ SEQ_GT(sack.start, ack_point) &&
+ SEQ_LT(sack.start, tp->snd_max) &&
+ SEQ_GT(sack.end, ack_point) &&
+ SEQ_LEQ(sack.end, tp->snd_max)) {
+ if ((rack->r_ctl.rc_num_maps_alloced > rack_sack_block_limit) &&
+ (SEQ_LT(sack.end, last_seq)) &&
+ ((sack.end - sack.start) < (tp->t_maxseg / 8))) {
+ /*
+ * Not the last piece and its smaller than
+ * 1/8th of a MSS. We ignore this.
+ */
+ counter_u64_add(rack_runt_sacks, 1);
+ continue;
+ }
+ sack_blocks[num_sack_blks] = sack;
+ num_sack_blks++;
+#ifdef NETFLIX_STATS
+ } else if (SEQ_LEQ(sack.start, th_ack) &&
+ SEQ_LEQ(sack.end, th_ack)) {
+ /*
+ * Its a D-SACK block.
+ */
+ tcp_record_dsack(sack.start, sack.end);
+#endif
+ }
+
+ }
+ if (num_sack_blks == 0)
+ goto out;
+ /*
+ * Sort the SACK blocks so we can update the rack scoreboard with
+ * just one pass.
+ */
+ if (rack_use_sack_filter) {
+ num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks, num_sack_blks, th->th_ack);
+ }
+ if (num_sack_blks < 2) {
+ goto do_sack_work;
+ }
+ /* Sort the sacks */
+ for (i = 0; i < num_sack_blks; i++) {
+ for (j = i + 1; j < num_sack_blks; j++) {
+ if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
+ sack = sack_blocks[i];
+ sack_blocks[i] = sack_blocks[j];
+ sack_blocks[j] = sack;
+ }
+ }
+ }
+ /*
+ * Now are any of the sack block ends the same (yes some
+ * implememtations send these)?
+ */
+again:
+ if (num_sack_blks > 1) {
+ for (i = 0; i < num_sack_blks; i++) {
+ for (j = i + 1; j < num_sack_blks; j++) {
+ if (sack_blocks[i].end == sack_blocks[j].end) {
+ /*
+ * Ok these two have the same end we
+ * want the smallest end and then
+ * throw away the larger and start
+ * again.
+ */
+ if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
+ /*
+ * The second block covers
+ * more area use that
+ */
+ sack_blocks[i].start = sack_blocks[j].start;
+ }
+ /*
+ * Now collapse out the dup-sack and
+ * lower the count
+ */
+ for (k = (j + 1); k < num_sack_blks; k++) {
+ sack_blocks[j].start = sack_blocks[k].start;
+ sack_blocks[j].end = sack_blocks[k].end;
+ j++;
+ }
+ num_sack_blks--;
+ goto again;
+ }
+ }
+ }
+ }
+do_sack_work:
+ rsm = rack->r_ctl.rc_sacklast;
+ for (i = 0; i < num_sack_blks; i++) {
+ acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts);
+ if (acked) {
+ rack->r_wanted_output++;
+ changed += acked;
+ sack_changed += acked;
+ }
+ }
+out:
+ if (changed) {
+ /* Something changed cancel the rack timer */
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ }
+ if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
+ /*
+ * Ok we have a high probability that we need to go in to
+ * recovery since we have data sack'd
+ */
+ struct rack_sendmap *rsm;
+ uint32_t tsused;
+
+ tsused = tcp_ts_getticks();
+ rsm = tcp_rack_output(tp, rack, tsused);
+ if (rsm) {
+ /* Enter recovery */
+ rack->r_ctl.rc_rsm_start = rsm->r_start;
+ rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
+ rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
+ entered_recovery = 1;
+ rack_cong_signal(tp, NULL, CC_NDUPACK);
+ /*
+ * When we enter recovery we need to assure we send
+ * one packet.
+ */
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ rack->r_timer_override = 1;
+ }
+ }
+ if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
+ /* Deal with changed an PRR here (in recovery only) */
+ uint32_t pipe, snd_una;
+
+ rack->r_ctl.rc_prr_delivered += changed;
+ /* Compute prr_sndcnt */
+ if (SEQ_GT(tp->snd_una, th_ack)) {
+ snd_una = tp->snd_una;
+ } else {
+ snd_una = th_ack;
+ }
+ pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
+ if (pipe > tp->snd_ssthresh) {
+ long sndcnt;
+
+ sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
+ if (rack->r_ctl.rc_prr_recovery_fs > 0)
+ sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
+ else {
+ rack->r_ctl.rc_prr_sndcnt = 0;
+ sndcnt = 0;
+ }
+ sndcnt++;
+ if (sndcnt > (long)rack->r_ctl.rc_prr_out)
+ sndcnt -= rack->r_ctl.rc_prr_out;
+ else
+ sndcnt = 0;
+ rack->r_ctl.rc_prr_sndcnt = sndcnt;
+ } else {
+ uint32_t limit;
+
+ if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
+ limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
+ else
+ limit = 0;
+ if (changed > limit)
+ limit = changed;
+ limit += tp->t_maxseg;
+ if (tp->snd_ssthresh > pipe) {
+ rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
+ } else {
+ rack->r_ctl.rc_prr_sndcnt = min(0, limit);
+ }
+ }
+ if (rack->r_ctl.rc_prr_sndcnt >= tp->t_maxseg) {
+ rack->r_timer_override = 1;
+ }
+ }
+}
+
+/*
+ * Return value of 1, we do not need to call rack_process_data().
+ * return value of 0, rack_process_data can be called.
+ * For ret_val if its 0 the TCP is locked, if its non-zero
+ * its unlocked and probably unsafe to touch the TCB.
+ */
+static int
+rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to,
+ int32_t * ti_locked, uint32_t tiwin, int32_t tlen,
+ int32_t * ofia, int32_t thflags, int32_t * ret_val)
+{
+ int32_t ourfinisacked = 0;
+ int32_t nsegs, acked_amount;
+ int32_t acked;
+ struct mbuf *mfree;
+ struct tcp_rack *rack;
+ int32_t recovery = 0;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (SEQ_GT(th->th_ack, tp->snd_max)) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, ret_val);
+ return (1);
+ }
+ if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
+ rack_log_ack(tp, to, th);
+ }
+ if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
+ /*
+ * Old ack, behind (or duplicate to) the last one rcv'd
+ * Note: Should mark reordering is occuring! We should also
+ * look for sack blocks arriving e.g. ack 1, 4-4 then ack 1,
+ * 3-3, 4-4 would be reording. As well as ack 1, 3-3 <no
+ * retran and> ack 3
+ */
+ return (0);
+ }
+ /*
+ * If we reach this point, ACK is not a duplicate, i.e., it ACKs
+ * something we sent.
+ */
+ if (tp->t_flags & TF_NEEDSYN) {
+ /*
+ * T/TCP: Connection was half-synchronized, and our SYN has
+ * been ACK'd (so connection is now fully synchronized). Go
+ * to non-starred state, increment snd_una for ACK of SYN,
+ * and check if we can do window scaling.
+ */
+ tp->t_flags &= ~TF_NEEDSYN;
+ tp->snd_una++;
+ /* Do window scaling? */
+ if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
+ (TF_RCVD_SCALE | TF_REQ_SCALE)) {
+ tp->rcv_scale = tp->request_r_scale;
+ /* Send window already scaled. */
+ }
+ }
+ nsegs = max(1, m->m_pkthdr.lro_nsegs);
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+
+ acked = BYTES_THIS_ACK(tp, th);
+ TCPSTAT_ADD(tcps_rcvackpack, nsegs);
+ TCPSTAT_ADD(tcps_rcvackbyte, acked);
+
+ /*
+ * If we just performed our first retransmit, and the ACK arrives
+ * within our recovery window, then it was a mistake to do the
+ * retransmit in the first place. Recover our original cwnd and
+ * ssthresh, and proceed to transmit where we left off.
+ */
+ if (tp->t_flags & TF_PREVVALID) {
+ tp->t_flags &= ~TF_PREVVALID;
+ if (tp->t_rxtshift == 1 &&
+ (int)(ticks - tp->t_badrxtwin) < 0)
+ rack_cong_signal(tp, th, CC_RTO_ERR);
+ }
+ /*
+ * If we have a timestamp reply, update smoothed round trip time. If
+ * no timestamp is present but transmit timer is running and timed
+ * sequence number was acked, update smoothed round trip time. Since
+ * we now have an rtt measurement, cancel the timer backoff (cf.,
+ * Phil Karn's retransmit alg.). Recompute the initial retransmit
+ * timer.
+ *
+ * Some boxes send broken timestamp replies during the SYN+ACK
+ * phase, ignore timestamps of 0 or we could calculate a huge RTT
+ * and blow up the retransmit timer.
+ */
+ /*
+ * If all outstanding data is acked, stop retransmit timer and
+ * remember to restart (more output or persist). If there is more
+ * data to be acked, restart retransmit timer, using current
+ * (possibly backed-off) value.
+ */
+ if (th->th_ack == tp->snd_max) {
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ rack->r_wanted_output++;
+ }
+ /*
+ * If no data (only SYN) was ACK'd, skip rest of ACK processing.
+ */
+ if (acked == 0) {
+ if (ofia)
+ *ofia = ourfinisacked;
+ return (0);
+ }
+ if (rack->r_ctl.rc_early_recovery) {
+ if (IN_FASTRECOVERY(tp->t_flags)) {
+ if (SEQ_LT(th->th_ack, tp->snd_recover)) {
+ tcp_rack_partialack(tp, th);
+ } else {
+ rack_post_recovery(tp, th);
+ recovery = 1;
+ }
+ }
+ }
+ /*
+ * Let the congestion control algorithm update congestion control
+ * related information. This typically means increasing the
+ * congestion window.
+ */
+ rack_ack_received(tp, rack, th, nsegs, CC_ACK, recovery);
+ SOCKBUF_LOCK(&so->so_snd);
+ acked_amount = min(acked, (int)sbavail(&so->so_snd));
+ tp->snd_wnd -= acked_amount;
+ mfree = sbcut_locked(&so->so_snd, acked_amount);
+ if ((sbused(&so->so_snd) == 0) &&
+ (acked > acked_amount) &&
+ (tp->t_state >= TCPS_FIN_WAIT_1)) {
+ ourfinisacked = 1;
+ }
+ /* NB: sowwakeup_locked() does an implicit unlock. */
+ sowwakeup_locked(so);
+ m_freem(mfree);
+ if (rack->r_ctl.rc_early_recovery == 0) {
+ if (IN_FASTRECOVERY(tp->t_flags)) {
+ if (SEQ_LT(th->th_ack, tp->snd_recover)) {
+ tcp_rack_partialack(tp, th);
+ } else {
+ rack_post_recovery(tp, th);
+ }
+ }
+ }
+ tp->snd_una = th->th_ack;
+ if (SEQ_GT(tp->snd_una, tp->snd_recover))
+ tp->snd_recover = tp->snd_una;
+
+ if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
+ tp->snd_nxt = tp->snd_una;
+ }
+ if (tp->snd_una == tp->snd_max) {
+ /* Nothing left outstanding */
+ rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
+ tp->t_acktime = 0;
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ /* Set need output so persist might get set */
+ rack->r_wanted_output++;
+ if (rack_use_sack_filter)
+ sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
+ if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
+ (sbavail(&so->so_snd) == 0) &&
+ (tp->t_flags2 & TF2_DROP_AF_DATA)) {
+ /*
+ * The socket was gone and the
+ * peer sent data, time to
+ * reset him.
+ */
+ *ret_val = 1;
+ tp = tcp_close(tp);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_UNLIMITED, tlen);
+ return (1);
+ }
+ }
+ if (ofia)
+ *ofia = ourfinisacked;
+ return (0);
+}
+
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ /*
+ * Update window information. Don't look at window if no ACK: TAC's
+ * send garbage on first SYN.
+ */
+ int32_t nsegs;
+#ifdef TCP_RFC7413
+ int32_t tfo_syn;
+#else
+#define tfo_syn (FALSE)
+#endif
+ struct tcp_rack *rack;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+
+ nsegs = max(1, m->m_pkthdr.lro_nsegs);
+ if ((thflags & TH_ACK) &&
+ (SEQ_LT(tp->snd_wl1, th->th_seq) ||
+ (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
+ (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
+ /* keep track of pure window updates */
+ if (tlen == 0 &&
+ tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
+ TCPSTAT_INC(tcps_rcvwinupd);
+ tp->snd_wnd = tiwin;
+ tp->snd_wl1 = th->th_seq;
+ tp->snd_wl2 = th->th_ack;
+ if (tp->snd_wnd > tp->max_sndwnd)
+ tp->max_sndwnd = tp->snd_wnd;
+ rack->r_wanted_output++;
+ } else if (thflags & TH_ACK) {
+ if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
+ tp->snd_wnd = tiwin;
+ tp->snd_wl1 = th->th_seq;
+ tp->snd_wl2 = th->th_ack;
+ }
+ }
+ /* Was persist timer active and now we have window space? */
+ if ((rack->rc_in_persist != 0) && tp->snd_wnd) {
+ rack_exit_persist(tp, rack);
+ tp->snd_nxt = tp->snd_max;
+ /* Make sure we output to start the timer */
+ rack->r_wanted_output++;
+ }
+ /*
+ * 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.
+ */
+#ifdef TCP_RFC7413
+ tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
+ (tp->t_flags & TF_FASTOPEN));
+#endif
+ if ((tlen || (thflags & TH_FIN) || tfo_syn) &&
+ TCPS_HAVERCVDFIN(tp->t_state) == 0) {
+ tcp_seq save_start = th->th_seq;
+
+ m_adj(m, drop_hdrlen); /* delayed header drop */
+ /*
+ * Insert segment which includes th into TCP reassembly
+ * queue with control block tp. Set thflags to whether
+ * reassembly now includes a segment with FIN. This handles
+ * the common case inline (segment is the next to be
+ * received on an established connection, and the queue is
+ * empty), avoiding linkage into and removal from the queue
+ * and repetition of various conversions. Set DELACK for
+ * segments received in order, but ack immediately when
+ * segments are out of order (so fast retransmit can work).
+ */
+ if (th->th_seq == tp->rcv_nxt &&
+ LIST_EMPTY(&tp->t_segq) &&
+ (TCPS_HAVEESTABLISHED(tp->t_state) ||
+ tfo_syn)) {
+ if (DELAY_ACK(tp, tlen) || tfo_syn) {
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ tp->t_flags |= TF_DELACK;
+ } else {
+ rack->r_wanted_output++;
+ tp->t_flags |= TF_ACKNOW;
+ }
+ tp->rcv_nxt += tlen;
+ thflags = th->th_flags & TH_FIN;
+ TCPSTAT_ADD(tcps_rcvpack, nsegs);
+ TCPSTAT_ADD(tcps_rcvbyte, tlen);
+ SOCKBUF_LOCK(&so->so_rcv);
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
+ m_freem(m);
+ else
+ sbappendstream_locked(&so->so_rcv, m, 0);
+ /* NB: sorwakeup_locked() does an implicit unlock. */
+ sorwakeup_locked(so);
+ } else {
+ /*
+ * XXX: Due to the header drop above "th" is
+ * theoretically invalid by now. Fortunately
+ * m_adj() doesn't actually frees any mbufs when
+ * trimming from the head.
+ */
+ thflags = tcp_reass(tp, th, &tlen, m);
+ tp->t_flags |= TF_ACKNOW;
+ }
+ if (tlen > 0)
+ tcp_update_sack_list(tp, save_start, save_start + tlen);
+ } else {
+ m_freem(m);
+ thflags &= ~TH_FIN;
+ }
+
+ /*
+ * If FIN is received ACK the FIN and let the user know that the
+ * connection is closing.
+ */
+ if (thflags & TH_FIN) {
+ if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
+ socantrcvmore(so);
+ /*
+ * If connection is half-synchronized (ie NEEDSYN
+ * flag on) then delay ACK, so it may be piggybacked
+ * when SYN is sent. Otherwise, since we received a
+ * FIN then no more input can be expected, send ACK
+ * now.
+ */
+ if (tp->t_flags & TF_NEEDSYN) {
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ tp->t_flags |= TF_DELACK;
+ } else {
+ tp->t_flags |= TF_ACKNOW;
+ }
+ tp->rcv_nxt++;
+ }
+ switch (tp->t_state) {
+
+ /*
+ * In SYN_RECEIVED and ESTABLISHED STATES enter the
+ * CLOSE_WAIT state.
+ */
+ case TCPS_SYN_RECEIVED:
+ tp->t_starttime = ticks;
+ /* FALLTHROUGH */
+ case TCPS_ESTABLISHED:
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ tcp_state_change(tp, TCPS_CLOSE_WAIT);
+ break;
+
+ /*
+ * If still in FIN_WAIT_1 STATE FIN has not been
+ * acked so enter the CLOSING state.
+ */
+ case TCPS_FIN_WAIT_1:
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ tcp_state_change(tp, TCPS_CLOSING);
+ break;
+
+ /*
+ * In FIN_WAIT_2 state enter the TIME_WAIT state,
+ * starting the time-wait timer, turning off the
+ * other standard timers.
+ */
+ case TCPS_FIN_WAIT_2:
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ KASSERT(*ti_locked == TI_RLOCKED, ("%s: dodata "
+ "TCP_FIN_WAIT_2 ti_locked: %d", __func__,
+ *ti_locked));
+ tcp_twstart(tp);
+ *ti_locked = TI_UNLOCKED;
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ return (1);
+ }
+ }
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ /*
+ * Return any desired output.
+ */
+ if ((tp->t_flags & TF_ACKNOW) || (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
+ rack->r_wanted_output++;
+ }
+ KASSERT(*ti_locked == TI_UNLOCKED, ("%s: check_delack ti_locked %d",
+ __func__, *ti_locked));
+ INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ return (0);
+}
+
+/*
+ * Here nothing is really faster, its just that we
+ * have broken out the fast-data path also just like
+ * the fast-ack.
+ */
+static int
+rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t nxt_pkt)
+{
+ int32_t nsegs;
+ int32_t newsize = 0; /* automatic sockbuf scaling */
+ struct tcp_rack *rack;
+#ifdef TCPDEBUG
+ /*
+ * The size of tcp_saveipgen must be the size of the max ip header,
+ * now IPv6.
+ */
+ u_char tcp_saveipgen[IP6_HDR_LEN];
+ struct tcphdr tcp_savetcp;
+ short ostate = 0;
+
+#endif
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * the timestamp. NOTE that the test is modified according to the
+ * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
+ */
+ if (__predict_false(th->th_seq != tp->rcv_nxt)) {
+ return (0);
+ }
+ if (__predict_false(tp->snd_nxt != tp->snd_max)) {
+ return (0);
+ }
+ if (tiwin && tiwin != tp->snd_wnd) {
+ return (0);
+ }
+ if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
+ return (0);
+ }
+ if (__predict_false((to->to_flags & TOF_TS) &&
+ (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
+ return (0);
+ }
+ if (__predict_false((th->th_ack != tp->snd_una))) {
+ return (0);
+ }
+ if (__predict_false(tlen > sbspace(&so->so_rcv))) {
+ return (0);
+ }
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ /*
+ * This is a pure, in-sequence data packet with nothing on the
+ * reassembly queue and we have enough buffer space to take it.
+ */
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ nsegs = max(1, m->m_pkthdr.lro_nsegs);
+
+
+ /* Clean receiver SACK report if present */
+ if (tp->rcv_numsacks)
+ tcp_clean_sackreport(tp);
+ TCPSTAT_INC(tcps_preddat);
+ tp->rcv_nxt += tlen;
+ /*
+ * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
+ */
+ tp->snd_wl1 = th->th_seq;
+ /*
+ * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
+ */
+ tp->rcv_up = tp->rcv_nxt;
+ TCPSTAT_ADD(tcps_rcvpack, nsegs);
+ TCPSTAT_ADD(tcps_rcvbyte, tlen);
+#ifdef TCPDEBUG
+ if (so->so_options & SO_DEBUG)
+ tcp_trace(TA_INPUT, ostate, tp,
+ (void *)tcp_saveipgen, &tcp_savetcp, 0);
+#endif
+ newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
+
+ /* Add data to socket buffer. */
+ SOCKBUF_LOCK(&so->so_rcv);
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
+ m_freem(m);
+ } else {
+ /*
+ * Set new socket buffer size. Give up when limit is
+ * reached.
+ */
+ if (newsize)
+ if (!sbreserve_locked(&so->so_rcv,
+ newsize, so, NULL))
+ so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
+ m_adj(m, drop_hdrlen); /* delayed header drop */
+ sbappendstream_locked(&so->so_rcv, m, 0);
+ rack_calc_rwin(so, tp);
+ }
+ /* NB: sorwakeup_locked() does an implicit unlock. */
+ sorwakeup_locked(so);
+ if (DELAY_ACK(tp, tlen)) {
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ tp->t_flags |= TF_DELACK;
+ } else {
+ tp->t_flags |= TF_ACKNOW;
+ rack->r_wanted_output++;
+ }
+ if ((tp->snd_una == tp->snd_max) && rack_use_sack_filter)
+ sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
+ return (1);
+}
+
+/*
+ * This subfunction is used to try to highly optimize the
+ * fast path. We again allow window updates that are
+ * in sequence to remain in the fast-path. We also add
+ * in the __predict's to attempt to help the compiler.
+ * Note that if we return a 0, then we can *not* process
+ * it and the caller should push the packet into the
+ * slow-path.
+ */
+static int
+rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
+{
+ int32_t acked;
+ int32_t nsegs;
+
+#ifdef TCPDEBUG
+ /*
+ * The size of tcp_saveipgen must be the size of the max ip header,
+ * now IPv6.
+ */
+ u_char tcp_saveipgen[IP6_HDR_LEN];
+ struct tcphdr tcp_savetcp;
+ short ostate = 0;
+
+#endif
+ struct tcp_rack *rack;
+
+ if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
+ /* Old ack, behind (or duplicate to) the last one rcv'd */
+ return (0);
+ }
+ if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
+ /* Above what we have sent? */
+ return (0);
+ }
+ if (__predict_false(tp->snd_nxt != tp->snd_max)) {
+ /* We are retransmitting */
+ return (0);
+ }
+ if (__predict_false(tiwin == 0)) {
+ /* zero window */
+ return (0);
+ }
+ if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
+ /* We need a SYN or a FIN, unlikely.. */
+ return (0);
+ }
+ if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
+ /* Timestamp is behind .. old ack with seq wrap? */
+ return (0);
+ }
+ if (__predict_false(IN_RECOVERY(tp->t_flags))) {
+ /* Still recovering */
+ return (0);
+ }
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (rack->r_ctl.rc_sacked) {
+ /* We have sack holes on our scoreboard */
+ return (0);
+ }
+ /* Ok if we reach here, we can process a fast-ack */
+ nsegs = max(1, m->m_pkthdr.lro_nsegs);
+ rack_log_ack(tp, to, th);
+ /* Did the window get updated? */
+ if (tiwin != tp->snd_wnd) {
+ tp->snd_wnd = tiwin;
+ tp->snd_wl1 = th->th_seq;
+ if (tp->snd_wnd > tp->max_sndwnd)
+ tp->max_sndwnd = tp->snd_wnd;
+ }
+ if ((rack->rc_in_persist != 0) && (tp->snd_wnd >= tp->t_maxseg)) {
+ rack_exit_persist(tp, rack);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * the timestamp. NOTE that the test is modified according to the
+ * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * This is a pure ack for outstanding data.
+ */
+ if (*ti_locked == TI_RLOCKED) {
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ }
+ TCPSTAT_INC(tcps_predack);
+
+ /*
+ * "bad retransmit" recovery.
+ */
+ if (tp->t_flags & TF_PREVVALID) {
+ tp->t_flags &= ~TF_PREVVALID;
+ if (tp->t_rxtshift == 1 &&
+ (int)(ticks - tp->t_badrxtwin) < 0)
+ rack_cong_signal(tp, th, CC_RTO_ERR);
+ }
+ /*
+ * Recalculate the transmit timer / rtt.
+ *
+ * Some boxes send broken timestamp replies during the SYN+ACK
+ * phase, ignore timestamps of 0 or we could calculate a huge RTT
+ * and blow up the retransmit timer.
+ */
+ acked = BYTES_THIS_ACK(tp, th);
+
+#ifdef TCP_HHOOK
+ /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
+ hhook_run_tcp_est_in(tp, th, to);
+#endif
+
+ TCPSTAT_ADD(tcps_rcvackpack, nsegs);
+ TCPSTAT_ADD(tcps_rcvackbyte, acked);
+ sbdrop(&so->so_snd, acked);
+ /*
+ * Let the congestion control algorithm update congestion control
+ * related information. This typically means increasing the
+ * congestion window.
+ */
+ rack_ack_received(tp, rack, th, nsegs, CC_ACK, 0);
+
+ tp->snd_una = th->th_ack;
+ /*
+ * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
+ */
+ tp->snd_wl2 = th->th_ack;
+ tp->t_dupacks = 0;
+ m_freem(m);
+ /* ND6_HINT(tp); *//* Some progress has been made. */
+
+ /*
+ * If all outstanding data are acked, stop retransmit timer,
+ * otherwise restart timer using current (possibly backed-off)
+ * value. If process is waiting for space, wakeup/selwakeup/signal.
+ * If data are ready to send, let tcp_output decide between more
+ * output or persist.
+ */
+#ifdef TCPDEBUG
+ if (so->so_options & SO_DEBUG)
+ tcp_trace(TA_INPUT, ostate, tp,
+ (void *)tcp_saveipgen,
+ &tcp_savetcp, 0);
+#endif
+ if (tp->snd_una == tp->snd_max) {
+ rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
+ tp->t_acktime = 0;
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ }
+ /* Wake up the socket if we have room to write more */
+ sowwakeup(so);
+ if (sbavail(&so->so_snd)) {
+ rack->r_wanted_output++;
+ }
+ return (1);
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t todrop;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+ /*
+ * If the state is SYN_SENT: if seg contains an ACK, but not for our
+ * SYN, drop the input. if seg contains a RST, then drop the
+ * connection. if seg does not contain SYN, then drop it. Otherwise
+ * this is an acceptable SYN segment initialize tp->rcv_nxt and
+ * tp->irs if seg contains ack then advance tp->snd_una if seg
+ * contains an ECE and ECN support is enabled, the stream is ECN
+ * capable. if SYN has been acked change to ESTABLISHED else
+ * SYN_RCVD state arrange for segment to be acked (eventually)
+ * continue processing rest of data/controls, beginning with URG
+ */
+ if ((thflags & TH_ACK) &&
+ (SEQ_LEQ(th->th_ack, tp->iss) ||
+ SEQ_GT(th->th_ack, tp->snd_max))) {
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
+ TCP_PROBE5(connect__refused, NULL, tp,
+ mtod(m, const char *), tp, th);
+ tp = tcp_drop(tp, ECONNREFUSED);
+ rack_do_drop(m, tp, ti_locked);
+ return (1);
+ }
+ if (thflags & TH_RST) {
+ rack_do_drop(m, tp, ti_locked);
+ return (1);
+ }
+ if (!(thflags & TH_SYN)) {
+ rack_do_drop(m, tp, ti_locked);
+ return (1);
+ }
+ tp->irs = th->th_seq;
+ tcp_rcvseqinit(tp);
+ if (thflags & TH_ACK) {
+ 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 there's data, delay ACK; if there's also a FIN ACKNOW
+ * will be turned on later.
+ */
+ if (DELAY_ACK(tp, tlen) && tlen != 0) {
+ rack_timer_cancel(tp, (struct tcp_rack *)tp->t_fb_ptr,
+ ((struct tcp_rack *)tp->t_fb_ptr)->r_ctl.rc_rcvtime, __LINE__);
+ tp->t_flags |= TF_DELACK;
+ } else {
+ ((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output++;
+ tp->t_flags |= TF_ACKNOW;
+ }
+
+ if ((thflags & TH_ECE) && V_tcp_do_ecn) {
+ tp->t_flags |= TF_ECN_PERMIT;
+ TCPSTAT_INC(tcps_ecn_shs);
+ }
+ /*
+ * 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);
+ }
+ KASSERT(*ti_locked == TI_RLOCKED, ("%s: trimthenstep6: "
+ "ti_locked %d", __func__, *ti_locked));
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ /*
+ * Advance th->th_seq to correspond to first data byte. If data,
+ * trim to stay within window, dropping FIN if necessary.
+ */
+ th->th_seq++;
+ if (tlen > tp->rcv_wnd) {
+ todrop = tlen - tp->rcv_wnd;
+ m_adj(m, -todrop);
+ tlen = tp->rcv_wnd;
+ thflags &= ~TH_FIN;
+ TCPSTAT_INC(tcps_rcvpackafterwin);
+ TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
+ }
+ tp->snd_wl1 = th->th_seq - 1;
+ tp->rcv_up = th->th_seq;
+ /*
+ * Client side of transaction: already sent SYN and data. If the
+ * remote host used T/TCP to validate the SYN, our data will be
+ * ACK'd; if so, enter normal data segment processing in the middle
+ * of step 5, ack processing. Otherwise, goto step 6.
+ */
+ if (thflags & TH_ACK) {
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
+ return (ret_val);
+ /* We may have changed to FIN_WAIT_1 above */
+ if (tp->t_state == TCPS_FIN_WAIT_1) {
+ /*
+ * In FIN_WAIT_1 STATE in addition to the processing
+ * for the ESTABLISHED state if our FIN is now
+ * acknowledged then enter FIN_WAIT_2.
+ */
+ if (ourfinisacked) {
+ /*
+ * If we can't receive any more data, then
+ * closing user can proceed. Starting the
+ * timer is contrary to the specification,
+ * but if we don't get a FIN we'll hang
+ * forever.
+ *
+ * XXXjl: we should release the tp also, and
+ * use a compressed state.
+ */
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
+ soisdisconnected(so);
+ tcp_timer_activate(tp, TT_2MSL,
+ (tcp_fast_finwait2_recycle ?
+ tcp_finwait2_timeout :
+ TP_MAXIDLE(tp)));
+ }
+ tcp_state_change(tp, TCPS_FIN_WAIT_2);
+ }
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+
+ if ((thflags & TH_ACK) &&
+ (SEQ_LEQ(th->th_ack, tp->snd_una) ||
+ SEQ_GT(th->th_ack, tp->snd_max))) {
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+#ifdef TCP_RFC7413
+ if (tp->t_flags & TF_FASTOPEN) {
+ /*
+ * When a TFO connection is in SYN_RECEIVED, the only valid
+ * packets are the initial SYN, a retransmit/copy of the
+ * initial SYN (possibly with a subset of the original
+ * data), a valid ACK, a FIN, or a RST.
+ */
+ if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ } else if (thflags & TH_SYN) {
+ /* non-initial SYN is ignored */
+ struct tcp_rack *rack;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
+ (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
+ (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ } else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+#endif
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ /*
+ * In the SYN-RECEIVED state, validate that the packet belongs to
+ * this connection before trimming the data to fit the receive
+ * window. Check the sequence number versus IRS since we know the
+ * sequence numbers haven't wrapped. This is a partial fix for the
+ * "LAND" DoS attack.
+ */
+ if (SEQ_LT(th->th_seq, tp->irs)) {
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+#ifdef TCP_RFC7413
+ if (tp->t_flags & TF_FASTOPEN) {
+ tp->snd_wnd = tiwin;
+ cc_conn_init(tp);
+ }
+#endif
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, 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;
+ tp->snd_wnd = tiwin;
+ }
+ /*
+ * 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);
+#ifdef TCP_RFC7413
+ if (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++;
+ }
+ /*
+ * 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 (!(tp->t_flags & TF_FASTOPEN))
+#endif
+ 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, 0,
+ (struct mbuf *)0);
+ tp->snd_wl1 = th->th_seq - 1;
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (tp->t_state == TCPS_FIN_WAIT_1) {
+ /* We could have went to FIN_WAIT_1 (or EST) above */
+ /*
+ * In FIN_WAIT_1 STATE in addition to the processing for the
+ * ESTABLISHED state if our FIN is now acknowledged then
+ * enter FIN_WAIT_2.
+ */
+ if (ourfinisacked) {
+ /*
+ * If we can't receive any more data, then closing
+ * user can proceed. Starting the timer is contrary
+ * to the specification, but if we don't get a FIN
+ * we'll hang forever.
+ *
+ * XXXjl: we should release the tp also, and use a
+ * compressed state.
+ */
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
+ soisdisconnected(so);
+ tcp_timer_activate(tp, TT_2MSL,
+ (tcp_fast_finwait2_recycle ?
+ tcp_finwait2_timeout :
+ TP_MAXIDLE(tp)));
+ }
+ tcp_state_change(tp, TCPS_FIN_WAIT_2);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+
+ /*
+ * Header prediction: check for the two common cases of a
+ * uni-directional data xfer. If the packet has no control flags,
+ * is in-sequence, the window didn't change and we're not
+ * retransmitting, it's a candidate. If the length is zero and the
+ * ack moved forward, we're the sender side of the xfer. Just free
+ * the data acked & wake any higher level process that was blocked
+ * waiting for space. If the length is non-zero and the ack didn't
+ * move, we're the receiver side. If we're getting packets in-order
+ * (the reassembly queue is empty), add the data toc The socket
+ * buffer and note that we need a delayed ack. Make sure that the
+ * hidden state-flags are also off. Since we check for
+ * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
+ */
+ if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
+ __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
+ __predict_true(LIST_EMPTY(&tp->t_segq)) &&
+ __predict_true(th->th_seq == tp->rcv_nxt)) {
+ struct tcp_rack *rack;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (tlen == 0) {
+ if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
+ ti_locked, tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
+ return (0);
+ }
+ } else {
+ if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
+ ti_locked, tiwin, nxt_pkt)) {
+ return (0);
+ }
+ }
+ }
+ rack_calc_rwin(so, tp);
+
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, NULL, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ /* State changes only happen in rack_process_data() */
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+
+ rack_calc_rwin(so, tp);
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, NULL, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+static int
+rack_check_data_after_close(struct mbuf *m,
+ struct tcpcb *tp, int32_t *ti_locked, int32_t *tlen, struct tcphdr *th, struct socket *so)
+{
+ struct tcp_rack *rack;
+
+ KASSERT(*ti_locked == TI_RLOCKED, ("%s: SS_NOFDEREF && "
+ "CLOSE_WAIT && tlen ti_locked %d", __func__, *ti_locked));
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (rack->rc_allow_data_af_clo == 0) {
+ close_now:
+ tp = tcp_close(tp);
+ TCPSTAT_INC(tcps_rcvafterclose);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_UNLIMITED, (*tlen));
+ return (1);
+ }
+ if (sbavail(&so->so_snd) == 0)
+ goto close_now;
+ /* Ok we allow data that is ignored and a followup reset */
+ tp->rcv_nxt = th->th_seq + *tlen;
+ tp->t_flags2 |= TF2_DROP_AF_DATA;
+ rack->r_wanted_output = 1;
+ *tlen = 0;
+ return (0);
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If new data are received on a connection after the user processes
+ * are gone, then RST the other end.
+ */
+ if ((so->so_state & SS_NOFDREF) && tlen) {
+ if (rack_check_data_after_close(m, tp, ti_locked, &tlen, th, so))
+ return (1);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (ourfinisacked) {
+ /*
+ * If we can't receive any more data, then closing user can
+ * proceed. Starting the timer is contrary to the
+ * specification, but if we don't get a FIN we'll hang
+ * forever.
+ *
+ * XXXjl: we should release the tp also, and use a
+ * compressed state.
+ */
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
+ soisdisconnected(so);
+ tcp_timer_activate(tp, TT_2MSL,
+ (tcp_fast_finwait2_recycle ?
+ tcp_finwait2_timeout :
+ TP_MAXIDLE(tp)));
+ }
+ tcp_state_change(tp, TCPS_FIN_WAIT_2);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If new data are received on a connection after the user processes
+ * are gone, then RST the other end.
+ */
+ if ((so->so_state & SS_NOFDREF) && tlen) {
+ if (rack_check_data_after_close(m, tp, ti_locked, &tlen, th, so))
+ return (1);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (ourfinisacked) {
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ tcp_twstart(tp);
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ *ti_locked = TI_UNLOCKED;
+ m_freem(m);
+ return (1);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If new data are received on a connection after the user processes
+ * are gone, then RST the other end.
+ */
+ if ((so->so_state & SS_NOFDREF) && tlen) {
+ if (rack_check_data_after_close(m, tp, ti_locked, &tlen, th, so))
+ return (1);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * case TCPS_LAST_ACK: Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (ourfinisacked) {
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ tp = tcp_close(tp);
+ rack_do_drop(m, tp, ti_locked);
+ return (1);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+
+/*
+ * Return value of 1, the TCB is unlocked and most
+ * likely gone, return value of 0, the TCP is still
+ * locked.
+ */
+static int
+rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
+ int32_t * ti_locked, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
+{
+ int32_t ret_val = 0;
+ int32_t ourfinisacked = 0;
+
+ rack_calc_rwin(so, tp);
+
+ /* Reset receive buffer auto scaling when not in bulk receive mode. */
+ if (thflags & TH_RST)
+ return (rack_process_rst(m, th, so, tp, ti_locked));
+ /*
+ * RFC5961 Section 4.2 Send challenge ACK for any SYN in
+ * synchronized state.
+ */
+ if (thflags & TH_SYN) {
+ rack_challenge_ack(m, th, tp, ti_locked, &ret_val);
+ return (ret_val);
+ }
+ /*
+ * RFC 1323 PAWS: If we have a timestamp reply on this segment and
+ * it's less than ts_recent, drop it.
+ */
+ if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
+ TSTMP_LT(to->to_tsval, tp->ts_recent)) {
+ if (rack_ts_check(m, th, tp, ti_locked, tlen, thflags, &ret_val))
+ return (ret_val);
+ }
+ if (rack_drop_checks(to, m, th, tp, &tlen, ti_locked, &thflags, &drop_hdrlen, &ret_val)) {
+ return (ret_val);
+ }
+ /*
+ * If new data are received on a connection after the user processes
+ * are gone, then RST the other end.
+ */
+ if ((so->so_state & SS_NOFDREF) &&
+ tlen) {
+ if (rack_check_data_after_close(m, tp, ti_locked, &tlen, th, so))
+ return (1);
+ }
+ /*
+ * If last ACK falls within this segment's sequence numbers, record
+ * its timestamp. NOTE: 1) That the test incorporates suggestions
+ * from the latest proposal of the tcplw@cray.com list (Braden
+ * 1993/04/26). 2) That updating only on newer timestamps interferes
+ * with our earlier PAWS tests, so this check should be solely
+ * predicated on the sequence space of this segment. 3) That we
+ * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
+ * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
+ * SEG.Len, This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated Vol. 2
+ * p.869. In such cases, we can still calculate the RTT correctly
+ * when RCV.NXT == Last.ACK.Sent.
+ */
+ if ((to->to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN | TH_FIN)) != 0))) {
+ tp->ts_recent_age = tcp_ts_getticks();
+ tp->ts_recent = to->to_tsval;
+ }
+ /*
+ * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
+ * is on (half-synchronized state), then queue data for later
+ * processing; else drop segment and return.
+ */
+ if ((thflags & TH_ACK) == 0) {
+ if (tp->t_flags & TF_NEEDSYN) {
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+ } else if (tp->t_flags & TF_ACKNOW) {
+ rack_do_dropafterack(m, tp, th, ti_locked, thflags, tlen, &ret_val);
+ return (ret_val);
+ } else {
+ rack_do_drop(m, NULL, ti_locked);
+ return (0);
+ }
+ }
+ /*
+ * Ack processing.
+ */
+ if (rack_process_ack(m, th, so, tp, to, ti_locked, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
+ return (ret_val);
+ }
+ if (sbavail(&so->so_snd)) {
+ if (rack_progress_timeout_check(tp)) {
+ tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
+ rack_do_dropwithreset(m, tp, th, ti_locked, BANDLIM_RST_OPENPORT, tlen);
+ return (1);
+ }
+ }
+ return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
+ ti_locked, tiwin, thflags, nxt_pkt));
+}
+
+
+static void inline
+rack_clear_rate_sample(struct tcp_rack *rack)
+{
+ rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
+ rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
+ rack->r_ctl.rack_rs.rs_rtt_tot = 0;
+}
+
+static int
+rack_init(struct tcpcb *tp)
+{
+ struct tcp_rack *rack = NULL;
+
+ tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
+ if (tp->t_fb_ptr == NULL) {
+ /*
+ * We need to allocate memory but cant. The INP and INP_INFO
+ * locks and they are recusive (happens during setup. So a
+ * scheme to drop the locks fails :(
+ *
+ */
+ return (ENOMEM);
+ }
+ memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ TAILQ_INIT(&rack->r_ctl.rc_map);
+ TAILQ_INIT(&rack->r_ctl.rc_free);
+ TAILQ_INIT(&rack->r_ctl.rc_tmap);
+ rack->rc_tp = tp;
+ if (tp->t_inpcb) {
+ rack->rc_inp = tp->t_inpcb;
+ }
+ /* Probably not needed but lets be sure */
+ rack_clear_rate_sample(rack);
+ rack->r_cpu = 0;
+ rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
+ rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
+ rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
+ rack->rc_pace_reduce = rack_slot_reduction;
+ if (V_tcp_delack_enabled)
+ tp->t_delayed_ack = 1;
+ else
+ tp->t_delayed_ack = 0;
+ rack->rc_pace_max_segs = rack_hptsi_segments;
+ rack->r_ctl.rc_early_recovery_segs = rack_early_recovery_max_seg;
+ rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
+ rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
+ rack->r_ctl.rc_prop_reduce = rack_use_proportional_reduce;
+ rack->r_idle_reduce_largest = rack_reduce_largest_on_idle;
+ rack->r_enforce_min_pace = rack_min_pace_time;
+ rack->r_min_pace_seg_thresh = rack_min_pace_time_seg_req;
+ rack->r_ctl.rc_prop_rate = rack_proportional_rate;
+ rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
+ rack->r_ctl.rc_early_recovery = rack_early_recovery;
+ rack->rc_always_pace = rack_pace_every_seg;
+ rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
+ rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
+ rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
+ rack->r_ctl.rc_min_to = rack_min_to;
+ rack->r_ctl.rc_prr_inc_var = rack_inc_var;
+ rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
+ if (tp->snd_una != tp->snd_max) {
+ /* Create a send map for the current outstanding data */
+ struct rack_sendmap *rsm;
+
+ rsm = rack_alloc(rack);
+ if (rsm == NULL) {
+ uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
+ tp->t_fb_ptr = NULL;
+ return (ENOMEM);
+ }
+ rsm->r_flags = RACK_OVERMAX;
+ rsm->r_tim_lastsent[0] = tcp_ts_getticks();
+ rsm->r_rtr_cnt = 1;
+ rsm->r_rtr_bytes = 0;
+ rsm->r_start = tp->snd_una;
+ rsm->r_end = tp->snd_max;
+ rsm->r_sndcnt = 0;
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_map, rsm, r_next);
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
+ rsm->r_in_tmap = 1;
+ }
+ return (0);
+}
+
+static int
+rack_handoff_ok(struct tcpcb *tp)
+{
+ if ((tp->t_state == TCPS_CLOSED) ||
+ (tp->t_state == TCPS_LISTEN)) {
+ /* Sure no problem though it may not stick */
+ return (0);
+ }
+ if ((tp->t_state == TCPS_SYN_SENT) ||
+ (tp->t_state == TCPS_SYN_RECEIVED)) {
+ /*
+ * We really don't know you have to get to ESTAB or beyond
+ * to tell.
+ */
+ return (EAGAIN);
+ }
+ if (tp->t_flags & TF_SACK_PERMIT) {
+ return (0);
+ }
+ /*
+ * If we reach here we don't do SACK on this connection so we can
+ * never do rack.
+ */
+ return (EINVAL);
+}
+
+static void
+rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
+{
+ if (tp->t_fb_ptr) {
+ struct tcp_rack *rack;
+ struct rack_sendmap *rsm;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+#ifdef TCP_BLACKBOX
+ tcp_log_flowend(tp);
+#endif
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ while (rsm) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_map, rsm, r_next);
+ uma_zfree(rack_zone, rsm);
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_map);
+ }
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
+ while (rsm) {
+ TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_next);
+ uma_zfree(rack_zone, rsm);
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
+ }
+ rack->rc_free_cnt = 0;
+ uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
+ tp->t_fb_ptr = NULL;
+ }
+}
+
+static void
+rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
+{
+ switch (tp->t_state) {
+ case TCPS_SYN_SENT:
+ rack->r_state = TCPS_SYN_SENT;
+ rack->r_substate = rack_do_syn_sent;
+ break;
+ case TCPS_SYN_RECEIVED:
+ rack->r_state = TCPS_SYN_RECEIVED;
+ rack->r_substate = rack_do_syn_recv;
+ break;
+ case TCPS_ESTABLISHED:
+ rack->r_state = TCPS_ESTABLISHED;
+ rack->r_substate = rack_do_established;
+ break;
+ case TCPS_CLOSE_WAIT:
+ rack->r_state = TCPS_CLOSE_WAIT;
+ rack->r_substate = rack_do_close_wait;
+ break;
+ case TCPS_FIN_WAIT_1:
+ rack->r_state = TCPS_FIN_WAIT_1;
+ rack->r_substate = rack_do_fin_wait_1;
+ break;
+ case TCPS_CLOSING:
+ rack->r_state = TCPS_CLOSING;
+ rack->r_substate = rack_do_closing;
+ break;
+ case TCPS_LAST_ACK:
+ rack->r_state = TCPS_LAST_ACK;
+ rack->r_substate = rack_do_lastack;
+ break;
+ case TCPS_FIN_WAIT_2:
+ rack->r_state = TCPS_FIN_WAIT_2;
+ rack->r_substate = rack_do_fin_wait_2;
+ break;
+ case TCPS_LISTEN:
+ case TCPS_CLOSED:
+ case TCPS_TIME_WAIT:
+ default:
+#ifdef INVARIANTS
+ panic("tcp tp:%p state:%d sees impossible state?", tp, tp->t_state);
+#endif
+ break;
+ };
+}
+
+
+static void
+rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
+{
+ /*
+ * We received an ack, and then did not
+ * call send or were bounced out due to the
+ * hpts was running. Now a timer is up as well, is
+ * it the right timer?
+ */
+ struct rack_sendmap *rsm;
+ int tmr_up;
+
+ tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
+ if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
+ return;
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
+ (tmr_up == PACE_TMR_RXT)) {
+ /* Should be an RXT */
+ return;
+ }
+ if (rsm == NULL) {
+ /* Nothing outstanding? */
+ if (tp->t_flags & TF_DELACK) {
+ if (tmr_up == PACE_TMR_DELACK)
+ /* We are supposed to have delayed ack up and we do */
+ return;
+ } else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
+ /*
+ * if we hit enobufs then we would expect the possiblity
+ * of nothing outstanding and the RXT up (and the hptsi timer).
+ */
+ return;
+ } else if (((tcp_always_keepalive ||
+ rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
+ (tp->t_state <= TCPS_CLOSING)) &&
+ (tmr_up == PACE_TMR_KEEP) &&
+ (tp->snd_max == tp->snd_una)) {
+ /* We should have keep alive up and we do */
+ return;
+ }
+ }
+ if (rsm && (rsm->r_flags & RACK_SACK_PASSED)) {
+ if ((tp->t_flags & TF_SENTFIN) &&
+ ((tp->snd_max - tp->snd_una) == 1) &&
+ (rsm->r_flags & RACK_HAS_FIN)) {
+ /* needs to be a RXT */
+ if (tmr_up == PACE_TMR_RXT)
+ return;
+ } else if (tmr_up == PACE_TMR_RACK)
+ return;
+ } else if (SEQ_GT(tp->snd_max,tp->snd_una) &&
+ ((tmr_up == PACE_TMR_TLP) ||
+ (tmr_up == PACE_TMR_RXT))) {
+ /*
+ * Either a TLP or RXT is fine if no sack-passed
+ * is in place and data is outstanding.
+ */
+ return;
+ } else if (tmr_up == PACE_TMR_DELACK) {
+ /*
+ * If the delayed ack was going to go off
+ * before the rtx/tlp/rack timer were going to
+ * expire, then that would be the timer in control.
+ * Note we don't check the time here trusting the
+ * code is correct.
+ */
+ return;
+ }
+ /*
+ * Ok the timer originally started is not what we want now.
+ * We will force the hpts to be stopped if any, and restart
+ * with the slot set to what was in the saved slot.
+ */
+ rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
+ rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
+}
+
+static void
+rack_hpts_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
+ int32_t ti_locked, int32_t nxt_pkt, struct timeval *tv)
+{
+ int32_t thflags, retval, did_out = 0;
+ int32_t way_out = 0;
+ uint32_t cts;
+ uint32_t tiwin;
+ struct tcpopt to;
+ struct tcp_rack *rack;
+ struct rack_sendmap *rsm;
+ int32_t prev_state = 0;
+
+ cts = tcp_tv_to_mssectick(tv);
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+
+ kern_prefetch(rack, &prev_state);
+ prev_state = 0;
+ thflags = th->th_flags;
+ /*
+ * If this is either a state-changing packet or current state isn't
+ * established, we require a read lock on tcbinfo. Otherwise, we
+ * allow the tcbinfo to be in either locked or unlocked, as the
+ * caller may have unnecessarily acquired a lock due to a race.
+ */
+ if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
+ tp->t_state != TCPS_ESTABLISHED) {
+ KASSERT(ti_locked == TI_RLOCKED, ("%s ti_locked %d for "
+ "SYN/FIN/RST/!EST", __func__, ti_locked));
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ } else {
+#ifdef INVARIANTS
+ if (ti_locked == TI_RLOCKED) {
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ } else {
+ KASSERT(ti_locked == TI_UNLOCKED, ("%s: EST "
+ "ti_locked: %d", __func__, ti_locked));
+ INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
+ }
+#endif
+ }
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
+ __func__));
+ KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
+ __func__));
+ {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ TCP_LOG_EVENT(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
+ tlen, &log, true);
+ }
+ /*
+ * Segment received on connection. Reset idle time and keep-alive
+ * timer. XXX: This should be done after segment validation to
+ * ignore broken/spoofed segs.
+ */
+ if (tp->t_idle_reduce && (tp->snd_max == tp->snd_una)) {
+#ifdef NETFLIX_CWV
+ if ((tp->cwv_enabled) &&
+ ((tp->cwv_cwnd_valid == 0) &&
+ TCPS_HAVEESTABLISHED(tp->t_state) &&
+ (tp->snd_cwnd > tp->snd_cwv.init_cwnd))) {
+ tcp_newcwv_nvp_closedown(tp);
+ } else
+#endif
+ if ((ticks - tp->t_rcvtime) >= tp->t_rxtcur) {
+ counter_u64_add(rack_input_idle_reduces, 1);
+ rack_cc_after_idle(tp,
+ (rack->r_idle_reduce_largest ? 1 :0));
+ }
+ }
+ rack->r_ctl.rc_rcvtime = cts;
+ tp->t_rcvtime = ticks;
+
+#ifdef NETFLIX_CWV
+ if (tp->cwv_enabled) {
+ if ((tp->cwv_cwnd_valid == 0) &&
+ TCPS_HAVEESTABLISHED(tp->t_state) &&
+ (tp->snd_cwnd > tp->snd_cwv.init_cwnd))
+ tcp_newcwv_nvp_closedown(tp);
+ }
+#endif
+ /*
+ * Unscale the window into a 32-bit value. For the SYN_SENT state
+ * the scale is zero.
+ */
+ tiwin = th->th_win << tp->snd_scale;
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
+#endif
+ /*
+ * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
+ * this to occur after we've validated the segment.
+ */
+ if (tp->t_flags & TF_ECN_PERMIT) {
+ if (thflags & TH_CWR)
+ tp->t_flags &= ~TF_ECN_SND_ECE;
+ switch (iptos & IPTOS_ECN_MASK) {
+ case IPTOS_ECN_CE:
+ tp->t_flags |= TF_ECN_SND_ECE;
+ TCPSTAT_INC(tcps_ecn_ce);
+ break;
+ case IPTOS_ECN_ECT0:
+ TCPSTAT_INC(tcps_ecn_ect0);
+ break;
+ case IPTOS_ECN_ECT1:
+ TCPSTAT_INC(tcps_ecn_ect1);
+ break;
+ }
+ /* Congestion experienced. */
+ if (thflags & TH_ECE) {
+ rack_cong_signal(tp, th, CC_ECN);
+ }
+ }
+ /*
+ * Parse options on any incoming segment.
+ */
+ tcp_dooptions(&to, (u_char *)(th + 1),
+ (th->th_off << 2) - sizeof(struct tcphdr),
+ (thflags & TH_SYN) ? TO_SYN : 0);
+
+ /*
+ * If echoed timestamp is later than the current time, fall back to
+ * non RFC1323 RTT calculation. Normalize timestamp if syncookies
+ * were used when this connection was established.
+ */
+ if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
+ to.to_tsecr -= tp->ts_offset;
+ if (TSTMP_GT(to.to_tsecr, cts))
+ to.to_tsecr = 0;
+ }
+ /*
+ * If its the first time in we need to take care of options and
+ * verify we can do SACK for rack!
+ */
+ if (rack->r_state == 0) {
+ /* Should be init'd by rack_init() */
+ KASSERT(rack->rc_inp != NULL,
+ ("%s: rack->rc_inp unexpectedly NULL", __func__));
+ if (rack->rc_inp == NULL) {
+ rack->rc_inp = tp->t_inpcb;
+ }
+
+ /*
+ * Process options only when we get SYN/ACK back. The SYN
+ * case for incoming connections is handled in tcp_syncache.
+ * According to RFC1323 the window field in a SYN (i.e., a
+ * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
+ * this is traditional behavior, may need to be cleaned up.
+ */
+ rack->r_cpu = inp_to_cpuid(tp->t_inpcb);
+ if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
+ if ((to.to_flags & TOF_SCALE) &&
+ (tp->t_flags & TF_REQ_SCALE)) {
+ tp->t_flags |= TF_RCVD_SCALE;
+ tp->snd_scale = to.to_wscale;
+ }
+ /*
+ * Initial send window. It will be updated with the
+ * next incoming segment to the scaled value.
+ */
+ tp->snd_wnd = th->th_win;
+ if (to.to_flags & TOF_TS) {
+ tp->t_flags |= TF_RCVD_TSTMP;
+ tp->ts_recent = to.to_tsval;
+ tp->ts_recent_age = cts;
+ }
+ if (to.to_flags & TOF_MSS)
+ tcp_mss(tp, to.to_mss);
+ if ((tp->t_flags & TF_SACK_PERMIT) &&
+ (to.to_flags & TOF_SACKPERM) == 0)
+ tp->t_flags &= ~TF_SACK_PERMIT;
+ }
+ /*
+ * At this point we are at the initial call. Here we decide
+ * if we are doing RACK or not. We do this by seeing if
+ * TF_SACK_PERMIT is set, if not rack is *not* possible and
+ * we switch to the default code.
+ */
+ if ((tp->t_flags & TF_SACK_PERMIT) == 0) {
+ tcp_switch_back_to_default(tp);
+ (*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
+ tlen, iptos, ti_locked);
+ return;
+ }
+ /* Set the flag */
+ rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
+ tcp_set_hpts(tp->t_inpcb);
+ rack_stop_all_timers(tp);
+ sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
+ }
+ /*
+ * This is the one exception case where we set the rack state
+ * always. All other times (timers etc) we must have a rack-state
+ * set (so we assure we have done the checks above for SACK).
+ */
+ if (rack->r_state != tp->t_state)
+ rack_set_state(tp, rack);
+ if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&rack->r_ctl.rc_map)) != NULL)
+ kern_prefetch(rsm, &prev_state);
+ prev_state = rack->r_state;
+ rack->r_ctl.rc_tlp_send_cnt = 0;
+ rack_clear_rate_sample(rack);
+ retval = (*rack->r_substate) (m, th, so,
+ tp, &to, drop_hdrlen,
+ tlen, &ti_locked, tiwin, thflags, nxt_pkt);
+#ifdef INVARIANTS
+ if ((retval == 0) &&
+ (tp->t_inpcb == NULL)) {
+ panic("retval:%d tp:%p t_inpcb:NULL state:%d",
+ retval, tp, prev_state);
+ }
+#endif
+ if (ti_locked != TI_UNLOCKED) {
+ INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ ti_locked = TI_UNLOCKED;
+ }
+ if (retval == 0) {
+ /*
+ * If retval is 1 the tcb is unlocked and most likely the tp
+ * is gone.
+ */
+ INP_WLOCK_ASSERT(tp->t_inpcb);
+ tcp_rack_xmit_timer_commit(rack, tp);
+ if (((tp->snd_max - tp->snd_una) > tp->snd_wnd) &&
+ (rack->rc_in_persist == 0)){
+ /*
+ * The peer shrunk its window on us to the point
+ * where we have sent too much. The only thing
+ * we can do here is stop any timers and
+ * enter persist. We most likely lost the last
+ * bytes we sent but oh well, we will have to
+ * retransmit them after the peer is caught up.
+ */
+ if (rack->rc_inp->inp_in_hpts)
+ tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
+ rack_timer_cancel(tp, rack, cts, __LINE__);
+ rack_enter_persist(tp, rack, cts);
+ rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
+ way_out = 3;
+ goto done_with_input;
+ }
+ if (nxt_pkt == 0) {
+ if (rack->r_wanted_output != 0) {
+ did_out = 1;
+ (void)tp->t_fb->tfb_tcp_output(tp);
+ }
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, 0, 0, 0);
+ }
+ if (((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
+ (SEQ_GT(tp->snd_max, tp->snd_una) ||
+ (tp->t_flags & TF_DELACK) ||
+ ((tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
+ (tp->t_state <= TCPS_CLOSING)))) {
+ /* We could not send (probably in the hpts but stopped the timer earlier)? */
+ if ((tp->snd_max == tp->snd_una) &&
+ ((tp->t_flags & TF_DELACK) == 0) &&
+ (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
+ /* keep alive not needed if we are hptsi output yet */
+ ;
+ } else {
+ if (rack->rc_inp->inp_in_hpts)
+ tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
+ rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), __LINE__, 0, 0, 0);
+ }
+ way_out = 1;
+ } else {
+ /* Do we have the correct timer running? */
+ rack_timer_audit(tp, rack, &so->so_snd);
+ way_out = 2;
+ }
+ done_with_input:
+ rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out);
+ if (did_out)
+ rack->r_wanted_output = 0;
+#ifdef INVARIANTS
+ if (tp->t_inpcb == NULL) {
+ panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
+ did_out,
+ retval, tp, prev_state);
+ }
+#endif
+ INP_WUNLOCK(tp->t_inpcb);
+ }
+}
+
+void
+rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
+ struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
+ int32_t ti_locked)
+{
+ struct timeval tv;
+#ifdef RSS
+ struct tcp_function_block *tfb;
+ struct tcp_rack *rack;
+ struct inpcb *inp;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (rack->r_state == 0) {
+ /*
+ * Initial input (ACK to SYN-ACK etc)lets go ahead and get
+ * it processed
+ */
+ if (ti_locked != TI_RLOCKED && INP_INFO_TRY_RLOCK(&V_tcbinfo))
+ ti_locked = TI_RLOCKED;
+ if (ti_locked != TI_RLOCKED) {
+ inp = tp->t_inpcb;
+ tfb = tp->t_fb;
+ in_pcbref(inp);
+ INP_WUNLOCK(inp);
+ INP_INFO_RLOCK(&V_tcbinfo);
+ ti_locked = TI_RLOCKED;
+ INP_WLOCK(inp);
+ if (in_pcbrele_wlocked(inp))
+ inp = NULL;
+ if (inp == NULL || (inp->inp_flags2 & INP_FREED) ||
+ (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED))) {
+ /* The TCPCB went away. Free the packet. */
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ if (inp)
+ INP_WUNLOCK(inp);
+ m_freem(m);
+ return;
+ }
+ /* If the stack changed, call the correct stack. */
+ if (tp->t_fb != tfb) {
+ tp->t_fb->tfb_tcp_do_segment(m, th, so, tp,
+ drop_hdrlen, tlen, iptos, ti_locked);
+ return;
+ }
+ }
+ tcp_get_usecs(&tv);
+ rack_hpts_do_segment(m, th, so, tp, drop_hdrlen,
+ tlen, iptos, ti_locked, 0, &tv);
+ return;
+ }
+ if (ti_locked == TI_RLOCKED)
+ INP_INFO_RUNLOCK(&V_tcbinfo);
+ tcp_queue_to_input(tp, m, th, tlen, drop_hdrlen, iptos, (uint8_t) ti_locked);
+ INP_WUNLOCK(tp->t_inpcb);
+#else
+ tcp_get_usecs(&tv);
+ rack_hpts_do_segment(m, th, so, tp, drop_hdrlen,
+ tlen, iptos, ti_locked, 0, &tv);
+#endif
+}
+
+struct rack_sendmap *
+tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
+{
+ struct rack_sendmap *rsm = NULL;
+ int32_t idx;
+ uint32_t srtt_cur, srtt = 0, thresh = 0, ts_low = 0;
+
+ /* Return the next guy to be re-transmitted */
+ if (TAILQ_EMPTY(&rack->r_ctl.rc_map)) {
+ return (NULL);
+ }
+ if (tp->t_flags & TF_SENTFIN) {
+ /* retran the end FIN? */
+ return (NULL);
+ }
+ /* ok lets look at this one */
+ rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
+ if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
+ goto check_it;
+ }
+ rsm = rack_find_lowest_rsm(rack);
+ if (rsm == NULL) {
+ return (NULL);
+ }
+check_it:
+ srtt_cur = tp->t_srtt >> TCP_RTT_SHIFT;
+ srtt = TICKS_2_MSEC(srtt_cur);
+ if (rack->rc_rack_rtt && (srtt > rack->rc_rack_rtt))
+ srtt = rack->rc_rack_rtt;
+ if (rsm->r_flags & RACK_ACKED) {
+ return (NULL);
+ }
+ if ((rsm->r_flags & RACK_SACK_PASSED) == 0) {
+ /* Its not yet ready */
+ return (NULL);
+ }
+ idx = rsm->r_rtr_cnt - 1;
+ ts_low = rsm->r_tim_lastsent[idx];
+ thresh = rack_calc_thresh_rack(rack, srtt, tsused);
+ if (tsused <= ts_low) {
+ return (NULL);
+ }
+ if ((tsused - ts_low) >= thresh) {
+ return (rsm);
+ }
+ return (NULL);
+}
+
+static int
+rack_output(struct tcpcb *tp)
+{
+ struct socket *so;
+ uint32_t recwin, sendwin;
+ uint32_t sb_offset;
+ int32_t len, flags, error = 0;
+ struct mbuf *m;
+ struct mbuf *mb;
+ uint32_t if_hw_tsomaxsegcount = 0;
+ uint32_t if_hw_tsomaxsegsize;
+ long tot_len_this_send = 0;
+ struct ip *ip = NULL;
+#ifdef TCPDEBUG
+ struct ipovly *ipov = NULL;
+#endif
+ struct udphdr *udp = NULL;
+ struct tcp_rack *rack;
+ struct tcphdr *th;
+ uint8_t pass = 0;
+ u_char opt[TCP_MAXOLEN];
+ unsigned ipoptlen, optlen, hdrlen, ulen=0;
+ uint32_t rack_seq;
+
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+ unsigned ipsec_optlen = 0;
+
+#endif
+ int32_t idle, sendalot;
+ int32_t sub_from_prr = 0;
+ volatile int32_t sack_rxmit;
+ struct rack_sendmap *rsm = NULL;
+ int32_t tso, mtu, would_have_fin = 0;
+ struct tcpopt to;
+ int32_t slot = 0;
+ uint32_t cts;
+ uint8_t hpts_calling, doing_tlp = 0;
+ int32_t do_a_prefetch;
+ int32_t prefetch_rsm = 0;
+ int32_t prefetch_so_done = 0;
+ struct tcp_log_buffer *lgb = NULL;
+ struct inpcb *inp;
+ struct sockbuf *sb;
+#ifdef INET6
+ struct ip6_hdr *ip6 = NULL;
+ int32_t isipv6;
+#endif
+ /* setup and take the cache hits here */
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ inp = rack->rc_inp;
+ so = inp->inp_socket;
+ sb = &so->so_snd;
+ kern_prefetch(sb, &do_a_prefetch);
+ do_a_prefetch = 1;
+
+ INP_WLOCK_ASSERT(inp);
+#ifdef TCP_OFFLOAD
+ if (tp->t_flags & TF_TOE)
+ return (tcp_offload_output(tp));
+#endif
+
+#ifdef TCP_RFC7413
+ /*
+ * For TFO connections in SYN_RECEIVED, only allow the initial
+ * SYN|ACK and those sent by the retransmit timer.
+ */
+ if ((tp->t_flags & TF_FASTOPEN) &&
+ (tp->t_state == TCPS_SYN_RECEIVED) &&
+ SEQ_GT(tp->snd_max, tp->snd_una) && /* inital SYN|ACK sent */
+ (tp->snd_nxt != tp->snd_una)) /* not a retransmit */
+ return (0);
+#endif
+#ifdef INET6
+ if (rack->r_state) {
+ /* Use the cache line loaded if possible */
+ isipv6 = rack->r_is_v6;
+ } else {
+ isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
+ }
+#endif
+ cts = tcp_ts_getticks();
+ if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
+ inp->inp_in_hpts) {
+ /*
+ * We are on the hpts for some timer but not hptsi output.
+ * Remove from the hpts unconditionally.
+ */
+ rack_timer_cancel(tp, rack, cts, __LINE__);
+ }
+ /* Mark that we have called rack_output(). */
+ if ((rack->r_timer_override) ||
+ (tp->t_flags & TF_FORCEDATA) ||
+ (tp->t_state < TCPS_ESTABLISHED)) {
+ if (tp->t_inpcb->inp_in_hpts)
+ tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
+ } else if (tp->t_inpcb->inp_in_hpts) {
+ /*
+ * On the hpts you can't pass even if ACKNOW is on, we will
+ * when the hpts fires.
+ */
+ counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
+ return (0);
+ }
+ hpts_calling = inp->inp_hpts_calls;
+ inp->inp_hpts_calls = 0;
+ if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
+ if (rack_process_timers(tp, rack, cts, hpts_calling)) {
+ counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
+ return (0);
+ }
+ }
+ rack->r_wanted_output = 0;
+ rack->r_timer_override = 0;
+ /*
+ * Determine length of data that should be transmitted, and flags
+ * that will be used. If there is some data or critical controls
+ * (SYN, RST) to send, then transmit; otherwise, investigate
+ * further.
+ */
+ idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
+#ifdef NETFLIX_CWV
+ if (tp->cwv_enabled) {
+ if ((tp->cwv_cwnd_valid == 0) &&
+ TCPS_HAVEESTABLISHED(tp->t_state) &&
+ (tp->snd_cwnd > tp->snd_cwv.init_cwnd))
+ tcp_newcwv_nvp_closedown(tp);
+ } else
+#endif
+ if (tp->t_idle_reduce) {
+ if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
+ rack_cc_after_idle(tp,
+ (rack->r_idle_reduce_largest ? 1 :0));
+ }
+ tp->t_flags &= ~TF_LASTIDLE;
+ if (idle) {
+ if (tp->t_flags & TF_MORETOCOME) {
+ tp->t_flags |= TF_LASTIDLE;
+ idle = 0;
+ }
+ }
+again:
+ /*
+ * If we've recently taken a timeout, snd_max will be greater than
+ * snd_nxt. There may be SACK information that allows us to avoid
+ * resending already delivered data. Adjust snd_nxt accordingly.
+ */
+ sendalot = 0;
+ cts = tcp_ts_getticks();
+ tso = 0;
+ mtu = 0;
+ sb_offset = tp->snd_max - tp->snd_una;
+ sendwin = min(tp->snd_wnd, tp->snd_cwnd);
+
+ flags = tcp_outflags[tp->t_state];
+ /*
+ * Send any SACK-generated retransmissions. If we're explicitly
+ * trying to send out new data (when sendalot is 1), bypass this
+ * function. If we retransmit in fast recovery mode, decrement
+ * snd_cwnd, since we're replacing a (future) new transmission with
+ * a retransmission now, and we previously incremented snd_cwnd in
+ * tcp_input().
+ */
+ /*
+ * Still in sack recovery , reset rxmit flag to zero.
+ */
+ while (rack->rc_free_cnt < rack_free_cache) {
+ rsm = rack_alloc(rack);
+ if (rsm == NULL) {
+ if (inp->inp_hpts_calls)
+ /* Retry in a ms */
+ slot = 1;
+ goto just_return_nolock;
+ }
+ TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_next);
+ rack->rc_free_cnt++;
+ rsm = NULL;
+ }
+ if (inp->inp_hpts_calls)
+ inp->inp_hpts_calls = 0;
+ sack_rxmit = 0;
+ len = 0;
+ rsm = NULL;
+ if (flags & TH_RST) {
+ SOCKBUF_LOCK(sb);
+ goto send;
+ }
+ if (rack->r_ctl.rc_tlpsend) {
+ /* Tail loss probe */
+ long cwin;
+ long tlen;
+
+ doing_tlp = 1;
+ rsm = rack->r_ctl.rc_tlpsend;
+ rack->r_ctl.rc_tlpsend = NULL;
+ sack_rxmit = 1;
+ tlen = rsm->r_end - rsm->r_start;
+ if (tlen > tp->t_maxseg)
+ tlen = tp->t_maxseg;
+#ifdef INVARIANTS
+ if (SEQ_GT(tp->snd_una, rsm->r_start)) {
+ panic("tp:%p rack:%p snd_una:%u rsm:%p r_start:%u",
+ tp, rack, tp->snd_una, rsm, rsm->r_start);
+ }
+#endif
+ sb_offset = rsm->r_start - tp->snd_una;
+ cwin = min(tp->snd_wnd, tlen);
+ len = cwin;
+ } else if (rack->r_ctl.rc_resend) {
+ /* Retransmit timer */
+ rsm = rack->r_ctl.rc_resend;
+ rack->r_ctl.rc_resend = NULL;
+ len = rsm->r_end - rsm->r_start;
+ sack_rxmit = 1;
+ sendalot = 0;
+ sb_offset = rsm->r_start - tp->snd_una;
+ if (len >= tp->t_maxseg) {
+ len = tp->t_maxseg;
+ }
+ KASSERT(sb_offset >= 0, ("%s: sack block to the left of una : %d",
+ __func__, sb_offset));
+ } else if ((rack->rc_in_persist == 0) &&
+ ((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) {
+ long tlen;
+
+ if ((!IN_RECOVERY(tp->t_flags)) &&
+ ((tp->t_flags & (TF_WASFRECOVERY | TF_WASCRECOVERY)) == 0)) {
+ /* Enter recovery if not induced by a time-out */
+ rack->r_ctl.rc_rsm_start = rsm->r_start;
+ rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
+ rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
+ rack_cong_signal(tp, NULL, CC_NDUPACK);
+ /*
+ * When we enter recovery we need to assure we send
+ * one packet.
+ */
+ rack->r_ctl.rc_prr_sndcnt = tp->t_maxseg;
+ }
+#ifdef INVARIANTS
+ if (SEQ_LT(rsm->r_start, tp->snd_una)) {
+ panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
+ tp, rack, rsm, rsm->r_start, tp->snd_una);
+ }
+#endif
+ tlen = rsm->r_end - rsm->r_start;
+ sb_offset = rsm->r_start - tp->snd_una;
+ if (tlen > rack->r_ctl.rc_prr_sndcnt) {
+ len = rack->r_ctl.rc_prr_sndcnt;
+ } else {
+ len = tlen;
+ }
+ if (len >= tp->t_maxseg) {
+ sendalot = 1;
+ len = tp->t_maxseg;
+ } else {
+ sendalot = 0;
+ if ((rack->rc_timer_up == 0) &&
+ (len < tlen)) {
+ /*
+ * If its not a timer don't send a partial
+ * segment.
+ */
+ len = 0;
+ goto just_return_nolock;
+ }
+ }
+ KASSERT(sb_offset >= 0, ("%s: sack block to the left of una : %d",
+ __func__, sb_offset));
+ if (len > 0) {
+ sub_from_prr = 1;
+ sack_rxmit = 1;
+ TCPSTAT_INC(tcps_sack_rexmits);
+ TCPSTAT_ADD(tcps_sack_rexmit_bytes,
+ min(len, tp->t_maxseg));
+ counter_u64_add(rack_rtm_prr_retran, 1);
+ }
+ }
+ if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
+ /* we are retransmitting the fin */
+ len--;
+ if (len) {
+ /*
+ * When retransmitting data do *not* include the
+ * FIN. This could happen from a TLP probe.
+ */
+ flags &= ~TH_FIN;
+ }
+ }
+#ifdef INVARIANTS
+ /* For debugging */
+ rack->r_ctl.rc_rsm_at_retran = rsm;
+#endif
+ /*
+ * Get standard flags, and add SYN or FIN if requested by 'hidden'
+ * state flags.
+ */
+ if (tp->t_flags & TF_NEEDFIN)
+ flags |= TH_FIN;
+ if (tp->t_flags & TF_NEEDSYN)
+ flags |= TH_SYN;
+ if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
+ void *end_rsm;
+ end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
+ if (end_rsm)
+ kern_prefetch(end_rsm, &prefetch_rsm);
+ prefetch_rsm = 1;
+ }
+ SOCKBUF_LOCK(sb);
+ /*
+ * If in persist timeout with window of 0, send 1 byte. Otherwise,
+ * if window is small but nonzero and time TF_SENTFIN expired, we
+ * will send what we can and go to transmit state.
+ */
+ if (tp->t_flags & TF_FORCEDATA) {
+ if (sendwin == 0) {
+ /*
+ * If we still have some data to send, then clear
+ * the FIN bit. Usually this would happen below
+ * when it realizes that we aren't sending all the
+ * data. However, if we have exactly 1 byte of
+ * unsent data, then it won't clear the FIN bit
+ * below, and if we are in persist state, we wind up
+ * sending the packet without recording that we sent
+ * the FIN bit.
+ *
+ * We can't just blindly clear the FIN bit, because
+ * if we don't have any more data to send then the
+ * probe will be the FIN itself.
+ */
+ if (sb_offset < sbused(sb))
+ flags &= ~TH_FIN;
+ sendwin = 1;
+ } else {
+ if (rack->rc_in_persist)
+ rack_exit_persist(tp, rack);
+ /*
+ * If we are dropping persist mode then we need to
+ * correct snd_nxt/snd_max and off.
+ */
+ tp->snd_nxt = tp->snd_max;
+ sb_offset = tp->snd_nxt - tp->snd_una;
+ }
+ }
+ /*
+ * If snd_nxt == snd_max and we have transmitted a FIN, the
+ * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
+ * negative length. This can also occur when TCP opens up its
+ * congestion window while receiving additional duplicate acks after
+ * fast-retransmit because TCP will reset snd_nxt to snd_max after
+ * the fast-retransmit.
+ *
+ * In the normal retransmit-FIN-only case, however, snd_nxt will be
+ * set to snd_una, the sb_offset will be 0, and the length may wind
+ * up 0.
+ *
+ * If sack_rxmit is true we are retransmitting from the scoreboard
+ * in which case len is already set.
+ */
+ if (sack_rxmit == 0) {
+ uint32_t avail;
+
+ avail = sbavail(sb);
+ if (SEQ_GT(tp->snd_nxt, tp->snd_una))
+ sb_offset = tp->snd_nxt - tp->snd_una;
+ else
+ sb_offset = 0;
+ if (IN_RECOVERY(tp->t_flags) == 0) {
+ if (rack->r_ctl.rc_tlp_new_data) {
+ /* TLP is forcing out new data */
+ if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
+ rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
+ }
+ if (rack->r_ctl.rc_tlp_new_data > tp->snd_wnd)
+ len = tp->snd_wnd;
+ else
+ len = rack->r_ctl.rc_tlp_new_data;
+ rack->r_ctl.rc_tlp_new_data = 0;
+ doing_tlp = 1;
+ } else {
+ if (sendwin > avail) {
+ /* use the available */
+ if (avail > sb_offset) {
+ len = (int32_t)(avail - sb_offset);
+ } else {
+ len = 0;
+ }
+ } else {
+ if (sendwin > sb_offset) {
+ len = (int32_t)(sendwin - sb_offset);
+ } else {
+ len = 0;
+ }
+ }
+ }
+ } else {
+ uint32_t outstanding;
+
+ /*
+ * We are inside of a SACK recovery episode and are
+ * sending new data, having retransmitted all the
+ * data possible so far in the scoreboard.
+ */
+ outstanding = tp->snd_max - tp->snd_una;
+ if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd)
+ len = 0;
+ else if (avail > sb_offset)
+ len = avail - sb_offset;
+ else
+ len = 0;
+ if (len > 0) {
+ if (len > rack->r_ctl.rc_prr_sndcnt)
+ len = rack->r_ctl.rc_prr_sndcnt;
+
+ if (len > 0) {
+ sub_from_prr = 1;
+ counter_u64_add(rack_rtm_prr_newdata, 1);
+ }
+ }
+ if (len > tp->t_maxseg) {
+ /*
+ * We should never send more than a MSS when
+ * retransmitting or sending new data in prr
+ * mode unless the override flag is on. Most
+ * likely the PRR algorithm is not going to
+ * let us send a lot as well :-)
+ */
+ if (rack->r_ctl.rc_prr_sendalot == 0)
+ len = tp->t_maxseg;
+ } else if (len < tp->t_maxseg) {
+ /*
+ * Do we send any? The idea here is if the
+ * send empty's the socket buffer we want to
+ * do it. However if not then lets just wait
+ * for our prr_sndcnt to get bigger.
+ */
+ long leftinsb;
+
+ leftinsb = sbavail(sb) - sb_offset;
+ if (leftinsb > len) {
+ /* This send does not empty the sb */
+ len = 0;
+ }
+ }
+ }
+ }
+ if (prefetch_so_done == 0) {
+ kern_prefetch(so, &prefetch_so_done);
+ prefetch_so_done = 1;
+ }
+ /*
+ * Lop off SYN bit if it has already been sent. However, if this is
+ * SYN-SENT state and if segment contains data and if we don't know
+ * that foreign host supports TAO, suppress sending segment.
+ */
+ if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una)) {
+ if ((tp->t_state != TCPS_SYN_RECEIVED) &&
+ (tp->t_state != TCPS_SYN_SENT))
+ flags &= ~TH_SYN;
+#ifdef TCP_RFC7413
+ /*
+ * When sending additional segments following a TFO SYN|ACK,
+ * do not include the SYN bit.
+ */
+ if ((tp->t_flags & TF_FASTOPEN) &&
+ (tp->t_state == TCPS_SYN_RECEIVED))
+ flags &= ~TH_SYN;
+#endif
+ sb_offset--, len++;
+ if (sbavail(sb) == 0)
+ len = 0;
+ }
+ /*
+ * 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;
+ }
+#ifdef TCP_RFC7413
+ /*
+ * When retransmitting SYN|ACK on a passively-created TFO socket,
+ * don't include data, as the presence of data may have caused the
+ * original SYN|ACK to have been dropped by a middlebox.
+ */
+ if ((tp->t_flags & TF_FASTOPEN) &&
+ ((tp->t_state == TCPS_SYN_RECEIVED) && (tp->t_rxtshift > 0)))
+ len = 0;
+#endif
+ if (len <= 0) {
+ /*
+ * If FIN has been sent but not acked, but we haven't been
+ * called to retransmit, len will be < 0. Otherwise, window
+ * shrank after we sent into it. If window shrank to 0,
+ * cancel pending retransmit, pull snd_nxt back to (closed)
+ * window, and set the persist timer if it isn't already
+ * going. If the window didn't close completely, just wait
+ * for an ACK.
+ *
+ * We also do a general check here to ensure that we will
+ * set the persist timer when we have data to send, but a
+ * 0-byte window. This makes sure the persist timer is set
+ * even if the packet hits one of the "goto send" lines
+ * below.
+ */
+ len = 0;
+ if ((tp->snd_wnd == 0) &&
+ (TCPS_HAVEESTABLISHED(tp->t_state)) &&
+ (sb_offset < (int)sbavail(sb))) {
+ tp->snd_nxt = tp->snd_una;
+ rack_enter_persist(tp, rack, cts);
+ }
+ }
+ /* len will be >= 0 after this point. */
+ KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
+ tcp_sndbuf_autoscale(tp, so, sendwin);
+ /*
+ * Decide if we can use TCP Segmentation Offloading (if supported by
+ * hardware).
+ *
+ * TSO may only be used if we are in a pure bulk sending state. The
+ * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
+ * options prevent using TSO. With TSO the TCP header is the same
+ * (except for the sequence number) for all generated packets. This
+ * makes it impossible to transmit any options which vary per
+ * generated segment or packet.
+ *
+ * IPv4 handling has a clear separation of ip options and ip header
+ * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
+ * the right thing below to provide length of just ip options and thus
+ * checking for ipoptlen is enough to decide if ip options are present.
+ */
+
+#ifdef INET6
+ if (isipv6)
+ ipoptlen = ip6_optlen(tp->t_inpcb);
+ else
+#endif
+ if (tp->t_inpcb->inp_options)
+ ipoptlen = tp->t_inpcb->inp_options->m_len -
+ offsetof(struct ipoption, ipopt_list);
+ else
+ ipoptlen = 0;
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+ /*
+ * Pre-calculate here as we save another lookup into the darknesses
+ * of IPsec that way and can actually decide if TSO is ok.
+ */
+#ifdef INET6
+ if (isipv6 && IPSEC_ENABLED(ipv6))
+ ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
+#ifdef INET
+ else
+#endif
+#endif /* INET6 */
+#ifdef INET
+ if (IPSEC_ENABLED(ipv4))
+ ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
+#endif /* INET */
+#endif
+
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+ ipoptlen += ipsec_optlen;
+#endif
+ if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > tp->t_maxseg &&
+ (tp->t_port == 0) &&
+ ((tp->t_flags & TF_SIGNATURE) == 0) &&
+ tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
+ ipoptlen == 0)
+ tso = 1;
+ {
+ uint32_t outstanding;
+
+ outstanding = tp->snd_max - tp->snd_una;
+ if (tp->t_flags & TF_SENTFIN) {
+ /*
+ * If we sent a fin, snd_max is 1 higher than
+ * snd_una
+ */
+ outstanding--;
+ }
+ if (outstanding > 0) {
+ /*
+ * This is sub-optimal. We only send a stand alone
+ * FIN on its own segment.
+ */
+ if (flags & TH_FIN) {
+ flags &= ~TH_FIN;
+ would_have_fin = 1;
+ }
+ } else if (sack_rxmit) {
+ if ((rsm->r_flags & RACK_HAS_FIN) == 0)
+ flags &= ~TH_FIN;
+ } else {
+ if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
+ sbused(sb)))
+ flags &= ~TH_FIN;
+ }
+ }
+ recwin = sbspace(&so->so_rcv);
+
+ /*
+ * Sender silly window avoidance. We transmit under the following
+ * conditions when len is non-zero:
+ *
+ * - We have a full segment (or more with TSO) - This is the last
+ * buffer in a write()/send() and we are either idle or running
+ * NODELAY - we've timed out (e.g. persist timer) - we have more
+ * then 1/2 the maximum send window's worth of data (receiver may be
+ * limited the window size) - we need to retransmit
+ */
+ if (len) {
+ if (len >= tp->t_maxseg) {
+ pass = 1;
+ goto send;
+ }
+ /*
+ * NOTE! on localhost connections an 'ack' from the remote
+ * end may occur synchronously with the output and cause us
+ * to flush a buffer queued with moretocome. XXX
+ *
+ */
+ if (!(tp->t_flags & TF_MORETOCOME) && /* normal case */
+ (idle || (tp->t_flags & TF_NODELAY)) &&
+ ((uint32_t)len + (uint32_t)sb_offset >= sbavail(&so->so_snd)) &&
+ (tp->t_flags & TF_NOPUSH) == 0) {
+ pass = 2;
+ goto send;
+ }
+ if (tp->t_flags & TF_FORCEDATA) { /* typ. timeout case */
+ pass = 3;
+ goto send;
+ }
+ if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
+ goto send;
+ }
+ if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
+ pass = 4;
+ goto send;
+ }
+ if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { /* retransmit case */
+ pass = 5;
+ goto send;
+ }
+ if (sack_rxmit) {
+ pass = 6;
+ goto send;
+ }
+ }
+ /*
+ * Sending of standalone window updates.
+ *
+ * Window updates are important when we close our window due to a
+ * full socket buffer and are opening it again after the application
+ * reads data from it. Once the window has opened again and the
+ * remote end starts to send again the ACK clock takes over and
+ * provides the most current window information.
+ *
+ * We must avoid the silly window syndrome whereas every read from
+ * the receive buffer, no matter how small, causes a window update
+ * to be sent. We also should avoid sending a flurry of window
+ * updates when the socket buffer had queued a lot of data and the
+ * application is doing small reads.
+ *
+ * Prevent a flurry of pointless window updates by only sending an
+ * update when we can increase the advertized window by more than
+ * 1/4th of the socket buffer capacity. When the buffer is getting
+ * full or is very small be more aggressive and send an update
+ * whenever we can increase by two mss sized segments. In all other
+ * situations the ACK's to new incoming data will carry further
+ * window increases.
+ *
+ * Don't send an independent window update if a delayed ACK is
+ * pending (it will get piggy-backed on it) or the remote side
+ * already has done a half-close and won't send more data. Skip
+ * this if the connection is in T/TCP half-open state.
+ */
+ if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
+ !(tp->t_flags & TF_DELACK) &&
+ !TCPS_HAVERCVDFIN(tp->t_state)) {
+ /*
+ * "adv" is the amount we could increase the window, taking
+ * into account that we are limited by TCP_MAXWIN <<
+ * tp->rcv_scale.
+ */
+ int32_t adv;
+ int oldwin;
+
+ adv = min(recwin, (long)TCP_MAXWIN << tp->rcv_scale);
+ if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
+ oldwin = (tp->rcv_adv - tp->rcv_nxt);
+ adv -= oldwin;
+ } else
+ oldwin = 0;
+
+ /*
+ * If the new window size ends up being the same as the old
+ * size when it is scaled, then don't force a window update.
+ */
+ if (oldwin >> tp->rcv_scale == (adv + oldwin) >> tp->rcv_scale)
+ goto dontupdate;
+
+ if (adv >= (int32_t)(2 * tp->t_maxseg) &&
+ (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
+ recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
+ so->so_rcv.sb_hiwat <= 8 * tp->t_maxseg)) {
+ pass = 7;
+ goto send;
+ }
+ if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
+ goto send;
+ }
+dontupdate:
+
+ /*
+ * Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW
+ * is also a catch-all for the retransmit timer timeout case.
+ */
+ if (tp->t_flags & TF_ACKNOW) {
+ pass = 8;
+ goto send;
+ }
+ if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
+ pass = 9;
+ goto send;
+ }
+ if (SEQ_GT(tp->snd_up, tp->snd_una)) {
+ pass = 10;
+ goto send;
+ }
+ /*
+ * If our state indicates that FIN should be sent and we have not
+ * yet done so, then we need to send.
+ */
+ if (flags & TH_FIN) {
+ if ((tp->t_flags & TF_SENTFIN) ||
+ (((tp->t_flags & TF_SENTFIN) == 0) &&
+ (tp->snd_nxt == tp->snd_una))) {
+ pass = 11;
+ goto send;
+ }
+ }
+ /*
+ * No reason to send a segment, just return.
+ */
+just_return:
+ SOCKBUF_UNLOCK(sb);
+just_return_nolock:
+ if (tot_len_this_send == 0)
+ counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, tot_len_this_send, 1);
+ rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling);
+ tp->t_flags &= ~TF_FORCEDATA;
+ return (0);
+
+send:
+ if (doing_tlp == 0) {
+ /*
+ * Data not a TLP, and its not the rxt firing. If it is the
+ * rxt firing, we want to leave the tlp_in_progress flag on
+ * so we don't send another TLP. It has to be a rack timer
+ * or normal send (response to acked data) to clear the tlp
+ * in progress flag.
+ */
+ rack->rc_tlp_in_progress = 0;
+ }
+ SOCKBUF_LOCK_ASSERT(sb);
+ if (len > 0) {
+ if (len >= tp->t_maxseg)
+ tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
+ else
+ tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
+ }
+ /*
+ * Before ESTABLISHED, force sending of initial options unless TCP
+ * set not to do any options. NOTE: we assume that the IP/TCP header
+ * plus TCP options always fit in a single mbuf, leaving room for a
+ * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
+ * + optlen <= MCLBYTES
+ */
+ optlen = 0;
+#ifdef INET6
+ if (isipv6)
+ hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
+ else
+#endif
+ hdrlen = sizeof(struct tcpiphdr);
+
+ /*
+ * Compute options for segment. We only have to care about SYN and
+ * established connection segments. Options for SYN-ACK segments
+ * are handled in TCP syncache.
+ */
+ to.to_flags = 0;
+ if ((tp->t_flags & TF_NOOPT) == 0) {
+ /* Maximum segment size. */
+ if (flags & TH_SYN) {
+ tp->snd_nxt = tp->iss;
+ to.to_mss = tcp_mssopt(&inp->inp_inc);
+#ifdef NETFLIX_TCPOUDP
+ if (tp->t_port)
+ to.to_mss -= V_tcp_udp_tunneling_overhead;
+#endif
+ to.to_flags |= TOF_MSS;
+#ifdef TCP_RFC7413
+ /*
+ * Only include the TFO option on the first
+ * transmission of the SYN|ACK on a
+ * passively-created TFO socket, as the presence of
+ * the TFO option may have caused the original
+ * SYN|ACK to have been dropped by a middlebox.
+ */
+ if ((tp->t_flags & TF_FASTOPEN) &&
+ (tp->t_state == TCPS_SYN_RECEIVED) &&
+ (tp->t_rxtshift == 0)) {
+ to.to_tfo_len = TCP_FASTOPEN_MAX_COOKIE_LEN;
+ to.to_tfo_cookie = (u_char *)&tp->t_tfo_cookie;
+ to.to_flags |= TOF_FASTOPEN;
+ }
+#endif
+ }
+ /* Window scaling. */
+ if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
+ to.to_wscale = tp->request_r_scale;
+ to.to_flags |= TOF_SCALE;
+ }
+ /* Timestamps. */
+ if ((tp->t_flags & TF_RCVD_TSTMP) ||
+ ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
+ to.to_tsval = cts + tp->ts_offset;
+ to.to_tsecr = tp->ts_recent;
+ to.to_flags |= TOF_TS;
+ }
+ /* Set receive buffer autosizing timestamp. */
+ if (tp->rfbuf_ts == 0 &&
+ (so->so_rcv.sb_flags & SB_AUTOSIZE))
+ tp->rfbuf_ts = tcp_ts_getticks();
+ /* Selective ACK's. */
+ if (flags & TH_SYN)
+ to.to_flags |= TOF_SACKPERM;
+ else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
+ tp->rcv_numsacks > 0) {
+ to.to_flags |= TOF_SACK;
+ to.to_nsacks = tp->rcv_numsacks;
+ to.to_sacks = (u_char *)tp->sackblks;
+ }
+#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
+ /* TCP-MD5 (RFC2385). */
+ if (tp->t_flags & TF_SIGNATURE)
+ to.to_flags |= TOF_SIGNATURE;
+#endif /* TCP_SIGNATURE */
+
+ /* Processing the options. */
+ hdrlen += optlen = tcp_addoptions(&to, opt);
+ }
+#ifdef NETFLIX_TCPOUDP
+ if (tp->t_port) {
+ if (V_tcp_udp_tunneling_port == 0) {
+ /* The port was removed?? */
+ SOCKBUF_UNLOCK(&so->so_snd);
+ return (EHOSTUNREACH);
+ }
+ hdrlen += sizeof(struct udphdr);
+ }
+#endif
+ ipoptlen = 0;
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+ ipoptlen += ipsec_optlen;
+#endif
+
+ /*
+ * Adjust data length if insertion of options will bump the packet
+ * length beyond the t_maxseg length. Clear the FIN bit because we
+ * cut off the tail of the segment.
+ */
+ if (len + optlen + ipoptlen > tp->t_maxseg) {
+ if (flags & TH_FIN) {
+ would_have_fin = 1;
+ flags &= ~TH_FIN;
+ }
+ if (tso) {
+ uint32_t if_hw_tsomax;
+ uint32_t moff;
+ int32_t max_len;
+
+ /* extract TSO information */
+ if_hw_tsomax = tp->t_tsomax;
+ if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
+ if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
+ KASSERT(ipoptlen == 0,
+ ("%s: TSO can't do IP options", __func__));
+
+ /*
+ * Check if we should limit by maximum payload
+ * length:
+ */
+ if (if_hw_tsomax != 0) {
+ /* compute maximum TSO length */
+ max_len = (if_hw_tsomax - hdrlen -
+ max_linkhdr);
+ if (max_len <= 0) {
+ len = 0;
+ } else if (len > max_len) {
+ sendalot = 1;
+ len = max_len;
+ }
+ }
+ /*
+ * Prevent the last segment from being fractional
+ * unless the send sockbuf can be emptied:
+ */
+ max_len = (tp->t_maxseg - optlen);
+ if ((sb_offset + len) < sbavail(sb)) {
+ moff = len % (u_int)max_len;
+ if (moff != 0) {
+ len -= moff;
+ sendalot = 1;
+ }
+ }
+ /*
+ * In case there are too many small fragments don't
+ * use TSO:
+ */
+ if (len <= max_len) {
+ len = max_len;
+ sendalot = 1;
+ tso = 0;
+ }
+ /*
+ * Send the FIN in a separate segment after the bulk
+ * sending is done. We don't trust the TSO
+ * implementations to clear the FIN flag on all but
+ * the last segment.
+ */
+ if (tp->t_flags & TF_NEEDFIN)
+ sendalot = 1;
+
+ } else {
+ len = tp->t_maxseg - optlen - ipoptlen;
+ sendalot = 1;
+ }
+ } else
+ tso = 0;
+ KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
+ ("%s: len > IP_MAXPACKET", __func__));
+#ifdef DIAGNOSTIC
+#ifdef INET6
+ if (max_linkhdr + hdrlen > MCLBYTES)
+#else
+ if (max_linkhdr + hdrlen > MHLEN)
+#endif
+ panic("tcphdr too big");
+#endif
+
+ /*
+ * This KASSERT is here to catch edge cases at a well defined place.
+ * Before, those had triggered (random) panic conditions further
+ * down.
+ */
+ KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
+ if ((len == 0) &&
+ (flags & TH_FIN) &&
+ (sbused(sb))) {
+ /*
+ * We have outstanding data, don't send a fin by itself!.
+ */
+ goto just_return;
+ }
+ /*
+ * Grab a header mbuf, attaching a copy of data to be transmitted,
+ * and initialize the header from the template for sends on this
+ * connection.
+ */
+ if (len) {
+ uint32_t max_val;
+ uint32_t moff;
+
+ if (rack->rc_pace_max_segs)
+ max_val = rack->rc_pace_max_segs * tp->t_maxseg;
+ else
+ max_val = len;
+ /*
+ * We allow a limit on sending with hptsi.
+ */
+ if (len > max_val) {
+ len = max_val;
+ }
+#ifdef INET6
+ if (MHLEN < hdrlen + max_linkhdr)
+ m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
+ else
+#endif
+ m = m_gethdr(M_NOWAIT, MT_DATA);
+
+ if (m == NULL) {
+ SOCKBUF_UNLOCK(sb);
+ error = ENOBUFS;
+ sack_rxmit = 0;
+ goto out;
+ }
+ m->m_data += max_linkhdr;
+ m->m_len = hdrlen;
+
+ /*
+ * Start the m_copy functions from the closest mbuf to the
+ * sb_offset in the socket buffer chain.
+ */
+ mb = sbsndptr_noadv(sb, sb_offset, &moff);
+ if (len <= MHLEN - hdrlen - max_linkhdr) {
+ m_copydata(mb, moff, (int)len,
+ mtod(m, caddr_t)+hdrlen);
+ if (SEQ_LT(tp->snd_nxt, tp->snd_max))
+ sbsndptr_adv(sb, mb, len);
+ m->m_len += len;
+ } else {
+ struct sockbuf *msb;
+
+ if (SEQ_LT(tp->snd_nxt, tp->snd_max))
+ msb = NULL;
+ else
+ msb = sb;
+ m->m_next = tcp_m_copym(mb, moff, &len,
+ if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb);
+ if (len <= (tp->t_maxseg - optlen)) {
+ /*
+ * Must have ran out of mbufs for the copy
+ * shorten it to no longer need tso. Lets
+ * not put on sendalot since we are low on
+ * mbufs.
+ */
+ tso = 0;
+ }
+ if (m->m_next == NULL) {
+ SOCKBUF_UNLOCK(sb);
+ (void)m_free(m);
+ error = ENOBUFS;
+ sack_rxmit = 0;
+ goto out;
+ }
+ }
+ if ((tp->t_flags & TF_FORCEDATA) && len == 1) {
+ TCPSTAT_INC(tcps_sndprobe);
+#ifdef NETFLIX_STATS
+ if (SEQ_LT(tp->snd_nxt, tp->snd_max))
+ stats_voi_update_abs_u32(tp->t_stats,
+ VOI_TCP_RETXPB, len);
+ else
+ stats_voi_update_abs_u64(tp->t_stats,
+ VOI_TCP_TXPB, len);
+#endif
+ } else if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
+ if (rsm && (rsm->r_flags & RACK_TLP)) {
+ /*
+ * TLP should not count in retran count, but
+ * in its own bin
+ */
+ counter_u64_add(rack_tlp_retran, 1);
+ counter_u64_add(rack_tlp_retran_bytes, len);
+ } else {
+ tp->t_sndrexmitpack++;
+ TCPSTAT_INC(tcps_sndrexmitpack);
+ TCPSTAT_ADD(tcps_sndrexmitbyte, len);
+ }
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
+ len);
+#endif
+ } else {
+ TCPSTAT_INC(tcps_sndpack);
+ TCPSTAT_ADD(tcps_sndbyte, len);
+#ifdef NETFLIX_STATS
+ stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
+ len);
+#endif
+ }
+ /*
+ * If we're sending everything we've got, set PUSH. (This
+ * will keep happy those implementations which only give
+ * data to the user when a buffer fills or a PUSH comes in.)
+ */
+ if (sb_offset + len == sbused(sb) &&
+ sbused(sb) &&
+ !(flags & TH_SYN))
+ flags |= TH_PUSH;
+
+ /*
+ * Are we doing hptsi, if so we must calculate the slot. We
+ * only do hptsi in ESTABLISHED and with no RESET being
+ * sent where we have data to send.
+ */
+ if (((tp->t_state == TCPS_ESTABLISHED) ||
+ (tp->t_state == TCPS_CLOSE_WAIT) ||
+ ((tp->t_state == TCPS_FIN_WAIT_1) &&
+ ((tp->t_flags & TF_SENTFIN) == 0) &&
+ ((flags & TH_FIN) == 0))) &&
+ ((flags & TH_RST) == 0) &&
+ (rack->rc_always_pace)) {
+ /*
+ * We use the most optimistic possible cwnd/srtt for
+ * sending calculations. This will make our
+ * calculation anticipate getting more through
+ * quicker then possible. But thats ok we don't want
+ * the peer to have a gap in data sending.
+ */
+ uint32_t srtt, cwnd, tr_perms = 0;
+
+ if (rack->r_ctl.rc_rack_min_rtt)
+ srtt = rack->r_ctl.rc_rack_min_rtt;
+ else
+ srtt = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT));
+ if (rack->r_ctl.rc_rack_largest_cwnd)
+ cwnd = rack->r_ctl.rc_rack_largest_cwnd;
+ else
+ cwnd = tp->snd_cwnd;
+ tr_perms = cwnd / srtt;
+ if (tr_perms == 0) {
+ tr_perms = tp->t_maxseg;
+ }
+ tot_len_this_send += len;
+ /*
+ * Calculate how long this will take to drain, if
+ * the calculation comes out to zero, thats ok we
+ * will use send_a_lot to possibly spin around for
+ * more increasing tot_len_this_send to the point
+ * that its going to require a pace, or we hit the
+ * cwnd. Which in that case we are just waiting for
+ * a ACK.
+ */
+ slot = tot_len_this_send / tr_perms;
+ /* Now do we reduce the time so we don't run dry? */
+ if (slot && rack->rc_pace_reduce) {
+ int32_t reduce;
+
+ reduce = (slot / rack->rc_pace_reduce);
+ if (reduce < slot) {
+ slot -= reduce;
+ } else
+ slot = 0;
+ }
+ if (rack->r_enforce_min_pace &&
+ (slot == 0) &&
+ (tot_len_this_send >= (rack->r_min_pace_seg_thresh * tp->t_maxseg))) {
+ /* We are enforcing a minimum pace time of 1ms */
+ slot = rack->r_enforce_min_pace;
+ }
+ }
+ SOCKBUF_UNLOCK(sb);
+ } else {
+ SOCKBUF_UNLOCK(sb);
+ if (tp->t_flags & TF_ACKNOW)
+ TCPSTAT_INC(tcps_sndacks);
+ else if (flags & (TH_SYN | TH_FIN | TH_RST))
+ TCPSTAT_INC(tcps_sndctrl);
+ else if (SEQ_GT(tp->snd_up, tp->snd_una))
+ TCPSTAT_INC(tcps_sndurg);
+ else
+ TCPSTAT_INC(tcps_sndwinup);
+
+ m = m_gethdr(M_NOWAIT, MT_DATA);
+ if (m == NULL) {
+ error = ENOBUFS;
+ sack_rxmit = 0;
+ goto out;
+ }
+#ifdef INET6
+ if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
+ MHLEN >= hdrlen) {
+ M_ALIGN(m, hdrlen);
+ } else
+#endif
+ m->m_data += max_linkhdr;
+ m->m_len = hdrlen;
+ }
+ SOCKBUF_UNLOCK_ASSERT(sb);
+ m->m_pkthdr.rcvif = (struct ifnet *)0;
+#ifdef MAC
+ mac_inpcb_create_mbuf(inp, m);
+#endif
+#ifdef INET6
+ if (isipv6) {
+ ip6 = mtod(m, struct ip6_hdr *);
+#ifdef NETFLIX_TCPOUDP
+ if (tp->t_port) {
+ udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
+ udp->uh_sport = htons(V_tcp_udp_tunneling_port);
+ udp->uh_dport = tp->t_port;
+ ulen = hdrlen + len - sizeof(struct ip6_hdr);
+ udp->uh_ulen = htons(ulen);
+ th = (struct tcphdr *)(udp + 1);
+ } else
+#endif
+ th = (struct tcphdr *)(ip6 + 1);
+ tcpip_fillheaders(inp, ip6, th);
+ } else
+#endif /* INET6 */
+ {
+ ip = mtod(m, struct ip *);
+#ifdef TCPDEBUG
+ ipov = (struct ipovly *)ip;
+#endif
+#ifdef NETFLIX_TCPOUDP
+ if (tp->t_port) {
+ udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
+ udp->uh_sport = htons(V_tcp_udp_tunneling_port);
+ udp->uh_dport = tp->t_port;
+ ulen = hdrlen + len - sizeof(struct ip);
+ udp->uh_ulen = htons(ulen);
+ th = (struct tcphdr *)(udp + 1);
+ } else
+#endif
+ th = (struct tcphdr *)(ip + 1);
+ tcpip_fillheaders(inp, ip, th);
+ }
+ /*
+ * Fill in fields, remembering maximum advertised window for use in
+ * delaying messages about window sizes. If resending a FIN, be sure
+ * not to use a new sequence number.
+ */
+ if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
+ tp->snd_nxt == tp->snd_max)
+ tp->snd_nxt--;
+ /*
+ * If we are starting a connection, send ECN setup SYN packet. If we
+ * are on a retransmit, we may resend those bits a number of times
+ * as per RFC 3168.
+ */
+ if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
+ if (tp->t_rxtshift >= 1) {
+ if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
+ flags |= TH_ECE | TH_CWR;
+ } else
+ flags |= TH_ECE | TH_CWR;
+ }
+ if (tp->t_state == TCPS_ESTABLISHED &&
+ (tp->t_flags & TF_ECN_PERMIT)) {
+ /*
+ * If the peer has ECN, mark data packets with ECN capable
+ * transmission (ECT). Ignore pure ack packets,
+ * retransmissions and window probes.
+ */
+ if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
+ !((tp->t_flags & TF_FORCEDATA) && len == 1)) {
+#ifdef INET6
+ if (isipv6)
+ ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
+ else
+#endif
+ ip->ip_tos |= IPTOS_ECN_ECT0;
+ TCPSTAT_INC(tcps_ecn_ect0);
+ }
+ /*
+ * Reply with proper ECN notifications.
+ */
+ if (tp->t_flags & TF_ECN_SND_CWR) {
+ flags |= TH_CWR;
+ tp->t_flags &= ~TF_ECN_SND_CWR;
+ }
+ if (tp->t_flags & TF_ECN_SND_ECE)
+ flags |= TH_ECE;
+ }
+ /*
+ * If we are doing retransmissions, then snd_nxt will not reflect
+ * the first unsent octet. For ACK only packets, we do not want the
+ * sequence number of the retransmitted packet, we want the sequence
+ * number of the next unsent octet. So, if there is no data (and no
+ * SYN or FIN), use snd_max instead of snd_nxt when filling in
+ * ti_seq. But if we are in persist state, snd_max might reflect
+ * one byte beyond the right edge of the window, so use snd_nxt in
+ * that case, since we know we aren't doing a retransmission.
+ * (retransmit and persist are mutually exclusive...)
+ */
+ if (sack_rxmit == 0) {
+ if (len || (flags & (TH_SYN | TH_FIN)) ||
+ rack->rc_in_persist) {
+ th->th_seq = htonl(tp->snd_nxt);
+ rack_seq = tp->snd_nxt;
+ } else if (flags & TH_RST) {
+ /*
+ * For a Reset send the last cum ack in sequence
+ * (this like any other choice may still generate a
+ * challenge ack, if a ack-update packet is in
+ * flight).
+ */
+ th->th_seq = htonl(tp->snd_una);
+ rack_seq = tp->snd_una;
+ } else {
+ th->th_seq = htonl(tp->snd_max);
+ rack_seq = tp->snd_max;
+ }
+ } else {
+ th->th_seq = htonl(rsm->r_start);
+ rack_seq = rsm->r_start;
+ }
+ th->th_ack = htonl(tp->rcv_nxt);
+ if (optlen) {
+ bcopy(opt, th + 1, optlen);
+ th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
+ }
+ th->th_flags = flags;
+ /*
+ * Calculate receive window. Don't shrink window, but avoid silly
+ * window syndrome.
+ */
+ if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
+ recwin < (long)tp->t_maxseg)
+ recwin = 0;
+ if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
+ recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
+ recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
+ if (recwin > (long)TCP_MAXWIN << tp->rcv_scale)
+ recwin = (long)TCP_MAXWIN << tp->rcv_scale;
+
+ /*
+ * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
+ * <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is
+ * handled in syncache.
+ */
+ if (flags & TH_SYN)
+ th->th_win = htons((u_short)
+ (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
+ else
+ th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
+ /*
+ * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
+ * window. This may cause the remote transmitter to stall. This
+ * flag tells soreceive() to disable delayed acknowledgements when
+ * draining the buffer. This can occur if the receiver is
+ * attempting to read more data than can be buffered prior to
+ * transmitting on the connection.
+ */
+ if (th->th_win == 0) {
+ tp->t_sndzerowin++;
+ tp->t_flags |= TF_RXWIN0SENT;
+ } else
+ tp->t_flags &= ~TF_RXWIN0SENT;
+ if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
+ th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
+ th->th_flags |= TH_URG;
+ } else
+ /*
+ * If no urgent pointer to send, then we pull the urgent
+ * pointer to the left edge of the send window so that it
+ * doesn't drift into the send window on sequence number
+ * wraparound.
+ */
+ tp->snd_up = tp->snd_una; /* drag it along */
+
+#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
+ if (to.to_flags & TOF_SIGNATURE) {
+ /*
+ * Calculate MD5 signature and put it into the place
+ * determined before.
+ * NOTE: since TCP options buffer doesn't point into
+ * mbuf's data, calculate offset and use it.
+ */
+ if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
+ (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
+ /*
+ * Do not send segment if the calculation of MD5
+ * digest has failed.
+ */
+ goto out;
+ }
+ }
+#endif
+
+ /*
+ * Put TCP length in extended header, and then checksum extended
+ * header and data.
+ */
+ m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
+#ifdef INET6
+ if (isipv6) {
+ /*
+ * ip6_plen is not need to be filled now, and will be filled
+ * in ip6_output.
+ */
+ if (tp->t_port) {
+ m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
+ m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
+ udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
+ th->th_sum = htons(0);
+ } else {
+ m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
+ m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
+ th->th_sum = in6_cksum_pseudo(ip6,
+ sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
+ 0);
+ }
+ }
+#endif
+#if defined(INET6) && defined(INET)
+ else
+#endif
+#ifdef INET
+ {
+ if (tp->t_port) {
+ m->m_pkthdr.csum_flags = CSUM_UDP;
+ m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
+ udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
+ ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
+ th->th_sum = htons(0);
+ } else {
+ m->m_pkthdr.csum_flags = CSUM_TCP;
+ m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
+ th->th_sum = in_pseudo(ip->ip_src.s_addr,
+ ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
+ IPPROTO_TCP + len + optlen));
+ }
+ /* IP version must be set here for ipv4/ipv6 checking later */
+ KASSERT(ip->ip_v == IPVERSION,
+ ("%s: IP version incorrect: %d", __func__, ip->ip_v));
+ }
+#endif
+
+ /*
+ * Enable TSO and specify the size of the segments. The TCP pseudo
+ * header checksum is always provided. XXX: Fixme: This is currently
+ * not the case for IPv6.
+ */
+ if (tso) {
+ KASSERT(len > tp->t_maxseg - optlen,
+ ("%s: len <= tso_segsz", __func__));
+ m->m_pkthdr.csum_flags |= CSUM_TSO;
+ m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
+ }
+#if defined(IPSEC) || defined(IPSEC_SUPPORT)
+ KASSERT(len + hdrlen + ipoptlen - ipsec_optlen == m_length(m, NULL),
+ ("%s: mbuf chain shorter than expected: %d + %u + %u - %u != %u",
+ __func__, len, hdrlen, ipoptlen, ipsec_optlen, m_length(m, NULL)));
+#else
+ KASSERT(len + hdrlen + ipoptlen == m_length(m, NULL),
+ ("%s: mbuf chain shorter than expected: %d + %u + %u != %u",
+ __func__, len, hdrlen, ipoptlen, m_length(m, NULL)));
+#endif
+
+#ifdef TCP_HHOOK
+ /* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
+ hhook_run_tcp_est_out(tp, th, &to, len, tso);
+#endif
+
+#ifdef TCPDEBUG
+ /*
+ * Trace.
+ */
+ if (so->so_options & SO_DEBUG) {
+ u_short save = 0;
+
+#ifdef INET6
+ if (!isipv6)
+#endif
+ {
+ save = ipov->ih_len;
+ ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen +
+ * (th->th_off << 2) */ );
+ }
+ tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0);
+#ifdef INET6
+ if (!isipv6)
+#endif
+ ipov->ih_len = save;
+ }
+#endif /* TCPDEBUG */
+
+ /* We're getting ready to send; log now. */
+ if (tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ memset(&log.u_bbr, 0, sizeof(log.u_bbr));
+ log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
+ log.u_bbr.ininput = rack->rc_inp->inp_in_input;
+ log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
+ if (rsm || sack_rxmit) {
+ log.u_bbr.flex8 = 1;
+ } else {
+ log.u_bbr.flex8 = 0;
+ }
+ lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
+ len, &log, false, NULL, NULL, 0, NULL);
+ } else
+ lgb = NULL;
+
+ /*
+ * Fill in IP length and desired time to live and send to IP level.
+ * There should be a better way to handle ttl and tos; we could keep
+ * them in the template, but need a way to checksum without them.
+ */
+ /*
+ * m->m_pkthdr.len should have been set before cksum calcuration,
+ * because in6_cksum() need it.
+ */
+#ifdef INET6
+ if (isipv6) {
+ /*
+ * we separately set hoplimit for every segment, since the
+ * user might want to change the value via setsockopt. Also,
+ * desired default hop limit might be changed via Neighbor
+ * Discovery.
+ */
+ ip6->ip6_hlim = in6_selecthlim(inp, NULL);
+
+ /*
+ * Set the packet size here for the benefit of DTrace
+ * probes. ip6_output() will set it properly; it's supposed
+ * to include the option header lengths as well.
+ */
+ ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
+
+ if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
+ tp->t_flags2 |= TF2_PLPMTU_PMTUD;
+ else
+ tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
+
+ if (tp->t_state == TCPS_SYN_SENT)
+ TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
+
+ TCP_PROBE5(send, NULL, tp, ip6, tp, th);
+ /* TODO: IPv6 IP6TOS_ECT bit on */
+ error = ip6_output(m, tp->t_inpcb->in6p_outputopts,
+ &inp->inp_route6,
+ ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0),
+ NULL, NULL, inp);
+
+ if (error == EMSGSIZE && inp->inp_route6.ro_rt != NULL)
+ mtu = inp->inp_route6.ro_rt->rt_mtu;
+ }
+#endif /* INET6 */
+#if defined(INET) && defined(INET6)
+ else
+#endif
+#ifdef INET
+ {
+ ip->ip_len = htons(m->m_pkthdr.len);
+#ifdef INET6
+ if (inp->inp_vflag & INP_IPV6PROTO)
+ ip->ip_ttl = in6_selecthlim(inp, NULL);
+#endif /* INET6 */
+ /*
+ * If we do path MTU discovery, then we set DF on every
+ * packet. This might not be the best thing to do according
+ * to RFC3390 Section 2. However the tcp hostcache migitates
+ * the problem so it affects only the first tcp connection
+ * with a host.
+ *
+ * NB: Don't set DF on small MTU/MSS to have a safe
+ * fallback.
+ */
+ if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
+ tp->t_flags2 |= TF2_PLPMTU_PMTUD;
+ if (tp->t_port == 0 || len < V_tcp_minmss) {
+ ip->ip_off |= htons(IP_DF);
+ }
+ } else {
+ tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
+ }
+
+ if (tp->t_state == TCPS_SYN_SENT)
+ TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
+
+ TCP_PROBE5(send, NULL, tp, ip, tp, th);
+
+ error = ip_output(m, tp->t_inpcb->inp_options, &inp->inp_route,
+ ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 0,
+ inp);
+ if (error == EMSGSIZE && inp->inp_route.ro_rt != NULL)
+ mtu = inp->inp_route.ro_rt->rt_mtu;
+ }
+#endif /* INET */
+
+out:
+ if (lgb) {
+ lgb->tlb_errno = error;
+ lgb = NULL;
+ }
+ /*
+ * In transmit state, time the transmission and arrange for the
+ * retransmit. In persist state, just set snd_max.
+ */
+ if (error == 0) {
+ if (len == 0)
+ counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
+ else if (len == 1) {
+ counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
+ } else if (len > 1) {
+ int idx;
+
+ idx = (len / tp->t_maxseg) + 3;
+ if (idx >= TCP_MSS_ACCT_ATIMER)
+ counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
+ else
+ counter_u64_add(rack_out_size[idx], 1);
+ }
+ }
+ if (sub_from_prr && (error == 0)) {
+ rack->r_ctl.rc_prr_sndcnt -= len;
+ }
+ sub_from_prr = 0;
+ rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts,
+ pass, rsm);
+ if ((tp->t_flags & TF_FORCEDATA) == 0 ||
+ (rack->rc_in_persist == 0)) {
+#ifdef NETFLIX_STATS
+ tcp_seq startseq = tp->snd_nxt;
+#endif
+
+ /*
+ * Advance snd_nxt over sequence space of this segment.
+ */
+ if (error)
+ /* We don't log or do anything with errors */
+ goto timer;
+
+ if (flags & (TH_SYN | TH_FIN)) {
+ if (flags & TH_SYN)
+ tp->snd_nxt++;
+ if (flags & TH_FIN) {
+ tp->snd_nxt++;
+ tp->t_flags |= TF_SENTFIN;
+ }
+ }
+ /* In the ENOBUFS case we do *not* update snd_max */
+ if (sack_rxmit)
+ goto timer;
+
+ tp->snd_nxt += len;
+ if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
+ if (tp->snd_una == tp->snd_max) {
+ /*
+ * Update the time we just added data since
+ * none was outstanding.
+ */
+ rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
+ tp->t_acktime = ticks;
+ }
+ tp->snd_max = tp->snd_nxt;
+#ifdef NETFLIX_STATS
+ if (!(tp->t_flags & TF_GPUTINPROG) && len) {
+ tp->t_flags |= TF_GPUTINPROG;
+ tp->gput_seq = startseq;
+ tp->gput_ack = startseq +
+ ulmin(sbavail(sb) - sb_offset, sendwin);
+ tp->gput_ts = tcp_ts_getticks();
+ }
+#endif
+ }
+ /*
+ * Set retransmit timer if not currently set, and not doing
+ * a pure ack or a keep-alive probe. Initial value for
+ * retransmit timer is smoothed round-trip time + 2 *
+ * round-trip time variance. Initialize shift counter which
+ * is used for backoff of retransmit time.
+ */
+timer:
+ if ((tp->snd_wnd == 0) &&
+ TCPS_HAVEESTABLISHED(tp->t_state)) {
+ /*
+ * If the persists timer was set above (right before
+ * the goto send), and still needs to be on. Lets
+ * make sure all is canceled. If the persist timer
+ * is not running, we want to get it up.
+ */
+ if (rack->rc_in_persist == 0) {
+ rack_enter_persist(tp, rack, cts);
+ }
+ }
+ } else {
+ /*
+ * Persist case, update snd_max but since we are in persist
+ * mode (no window) we do not update snd_nxt.
+ */
+ int32_t xlen = len;
+
+ if (error)
+ goto nomore;
+
+ if (flags & TH_SYN)
+ ++xlen;
+ if (flags & TH_FIN) {
+ ++xlen;
+ tp->t_flags |= TF_SENTFIN;
+ }
+ /* In the ENOBUFS case we do *not* update snd_max */
+ if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max)) {
+ if (tp->snd_una == tp->snd_max) {
+ /*
+ * Update the time we just added data since
+ * none was outstanding.
+ */
+ rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
+ tp->t_acktime = ticks;
+ }
+ tp->snd_max = tp->snd_nxt + len;
+ }
+ }
+nomore:
+ if (error) {
+ SOCKBUF_UNLOCK_ASSERT(sb); /* Check gotos. */
+ /*
+ * Failures do not advance the seq counter above. For the
+ * case of ENOBUFS we will fall out and retry in 1ms with
+ * the hpts. Everything else will just have to retransmit
+ * with the timer.
+ *
+ * In any case, we do not want to loop around for another
+ * send without a good reason.
+ */
+ sendalot = 0;
+ switch (error) {
+ case EPERM:
+ tp->t_flags &= ~TF_FORCEDATA;
+ tp->t_softerror = error;
+ return (error);
+ case ENOBUFS:
+ if (slot == 0) {
+ /*
+ * Pace us right away to retry in a some
+ * time
+ */
+ slot = 1 + rack->rc_enobuf;
+ if (rack->rc_enobuf < 255)
+ rack->rc_enobuf++;
+ if (slot > (rack->rc_rack_rtt / 2)) {
+ slot = rack->rc_rack_rtt / 2;
+ }
+ if (slot < 10)
+ slot = 10;
+ }
+ counter_u64_add(rack_saw_enobuf, 1);
+ error = 0;
+ goto enobufs;
+ case EMSGSIZE:
+ /*
+ * For some reason the interface we used initially
+ * to send segments changed to another or lowered
+ * its MTU. If TSO was active we either got an
+ * interface without TSO capabilits or TSO was
+ * turned off. If we obtained mtu from ip_output()
+ * then update it and try again.
+ */
+ if (tso)
+ tp->t_flags &= ~TF_TSO;
+ if (mtu != 0) {
+ tcp_mss_update(tp, -1, mtu, NULL, NULL);
+ goto again;
+ }
+ slot = 10;
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, 0, 1);
+ tp->t_flags &= ~TF_FORCEDATA;
+ return (error);
+ case ENETUNREACH:
+ counter_u64_add(rack_saw_enetunreach, 1);
+ case EHOSTDOWN:
+ case EHOSTUNREACH:
+ case ENETDOWN:
+ if (TCPS_HAVERCVDSYN(tp->t_state)) {
+ tp->t_softerror = error;
+ }
+ /* FALLTHROUGH */
+ default:
+ slot = 10;
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, 0, 1);
+ tp->t_flags &= ~TF_FORCEDATA;
+ return (error);
+ }
+ } else {
+ rack->rc_enobuf = 0;
+ }
+ TCPSTAT_INC(tcps_sndtotal);
+
+ /*
+ * Data sent (as far as we can tell). If this advertises a larger
+ * window than any other segment, then remember the size of the
+ * advertised window. Any pending ACK has now been sent.
+ */
+ if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
+ tp->rcv_adv = tp->rcv_nxt + recwin;
+ tp->last_ack_sent = tp->rcv_nxt;
+ tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
+enobufs:
+ rack->r_tlp_running = 0;
+ if ((flags & TH_RST) || (would_have_fin == 1)) {
+ /*
+ * We don't send again after a RST. We also do *not* send
+ * again if we would have had a find, but now have
+ * outstanding data.
+ */
+ slot = 0;
+ sendalot = 0;
+ }
+ if (slot) {
+ /* set the rack tcb into the slot N */
+ counter_u64_add(rack_paced_segments, 1);
+ } else if (sendalot) {
+ if (len)
+ counter_u64_add(rack_unpaced_segments, 1);
+ sack_rxmit = 0;
+ tp->t_flags &= ~TF_FORCEDATA;
+ goto again;
+ } else if (len) {
+ counter_u64_add(rack_unpaced_segments, 1);
+ }
+ tp->t_flags &= ~TF_FORCEDATA;
+ rack_start_hpts_timer(rack, tp, cts, __LINE__, slot, tot_len_this_send, 1);
+ return (error);
+}
+
+/*
+ * rack_ctloutput() must drop the inpcb lock before performing copyin on
+ * socket option arguments. When it re-acquires the lock after the copy, it
+ * has to revalidate that the connection is still valid for the socket
+ * option.
+ */
+static int
+rack_set_sockopt(struct socket *so, struct sockopt *sopt,
+ struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
+{
+ int32_t error = 0, optval;
+
+ switch (sopt->sopt_name) {
+ case TCP_RACK_PROP_RATE:
+ case TCP_RACK_PROP:
+ case TCP_RACK_TLP_REDUCE:
+ case TCP_RACK_EARLY_RECOV:
+ case TCP_RACK_PACE_ALWAYS:
+ case TCP_DELACK:
+ case TCP_RACK_PACE_REDUCE:
+ case TCP_RACK_PACE_MAX_SEG:
+ case TCP_RACK_PRR_SENDALOT:
+ case TCP_RACK_MIN_TO:
+ case TCP_RACK_EARLY_SEG:
+ case TCP_RACK_REORD_THRESH:
+ case TCP_RACK_REORD_FADE:
+ case TCP_RACK_TLP_THRESH:
+ case TCP_RACK_PKT_DELAY:
+ case TCP_RACK_TLP_USE:
+ case TCP_RACK_TLP_INC_VAR:
+ case TCP_RACK_IDLE_REDUCE_HIGH:
+ case TCP_RACK_MIN_PACE:
+ case TCP_RACK_MIN_PACE_SEG:
+ case TCP_BBR_RACK_RTT_USE:
+ case TCP_DATA_AFTER_CLOSE:
+ break;
+ default:
+ return (tcp_default_ctloutput(so, sopt, inp, tp));
+ break;
+ }
+ INP_WUNLOCK(inp);
+ error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
+ if (error)
+ return (error);
+ INP_WLOCK(inp);
+ if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
+ INP_WUNLOCK(inp);
+ return (ECONNRESET);
+ }
+ tp = intotcpcb(inp);
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ switch (sopt->sopt_name) {
+ case TCP_RACK_PROP_RATE:
+ if ((optval <= 0) || (optval >= 100)) {
+ error = EINVAL;
+ break;
+ }
+ RACK_OPTS_INC(tcp_rack_prop_rate);
+ rack->r_ctl.rc_prop_rate = optval;
+ break;
+ case TCP_RACK_TLP_USE:
+ if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
+ error = EINVAL;
+ break;
+ }
+ RACK_OPTS_INC(tcp_tlp_use);
+ rack->rack_tlp_threshold_use = optval;
+ break;
+ case TCP_RACK_PROP:
+ /* RACK proportional rate reduction (bool) */
+ RACK_OPTS_INC(tcp_rack_prop);
+ rack->r_ctl.rc_prop_reduce = optval;
+ break;
+ case TCP_RACK_TLP_REDUCE:
+ /* RACK TLP cwnd reduction (bool) */
+ RACK_OPTS_INC(tcp_rack_tlp_reduce);
+ rack->r_ctl.rc_tlp_cwnd_reduce = optval;
+ break;
+ case TCP_RACK_EARLY_RECOV:
+ /* Should recovery happen early (bool) */
+ RACK_OPTS_INC(tcp_rack_early_recov);
+ rack->r_ctl.rc_early_recovery = optval;
+ break;
+ case TCP_RACK_PACE_ALWAYS:
+ /* Use the always pace method (bool) */
+ RACK_OPTS_INC(tcp_rack_pace_always);
+ if (optval > 0)
+ rack->rc_always_pace = 1;
+ else
+ rack->rc_always_pace = 0;
+ break;
+ case TCP_RACK_PACE_REDUCE:
+ /* RACK Hptsi reduction factor (divisor) */
+ RACK_OPTS_INC(tcp_rack_pace_reduce);
+ if (optval)
+ /* Must be non-zero */
+ rack->rc_pace_reduce = optval;
+ else
+ error = EINVAL;
+ break;
+ case TCP_RACK_PACE_MAX_SEG:
+ /* Max segments in a pace */
+ RACK_OPTS_INC(tcp_rack_max_seg);
+ rack->rc_pace_max_segs = optval;
+ break;
+ case TCP_RACK_PRR_SENDALOT:
+ /* Allow PRR to send more than one seg */
+ RACK_OPTS_INC(tcp_rack_prr_sendalot);
+ rack->r_ctl.rc_prr_sendalot = optval;
+ break;
+ case TCP_RACK_MIN_TO:
+ /* Minimum time between rack t-o's in ms */
+ RACK_OPTS_INC(tcp_rack_min_to);
+ rack->r_ctl.rc_min_to = optval;
+ break;
+ case TCP_RACK_EARLY_SEG:
+ /* If early recovery max segments */
+ RACK_OPTS_INC(tcp_rack_early_seg);
+ rack->r_ctl.rc_early_recovery_segs = optval;
+ break;
+ case TCP_RACK_REORD_THRESH:
+ /* RACK reorder threshold (shift amount) */
+ RACK_OPTS_INC(tcp_rack_reord_thresh);
+ if ((optval > 0) && (optval < 31))
+ rack->r_ctl.rc_reorder_shift = optval;
+ else
+ error = EINVAL;
+ break;
+ case TCP_RACK_REORD_FADE:
+ /* Does reordering fade after ms time */
+ RACK_OPTS_INC(tcp_rack_reord_fade);
+ rack->r_ctl.rc_reorder_fade = optval;
+ break;
+ case TCP_RACK_TLP_THRESH:
+ /* RACK TLP theshold i.e. srtt+(srtt/N) */
+ RACK_OPTS_INC(tcp_rack_tlp_thresh);
+ if (optval)
+ rack->r_ctl.rc_tlp_threshold = optval;
+ else
+ error = EINVAL;
+ break;
+ case TCP_RACK_PKT_DELAY:
+ /* RACK added ms i.e. rack-rtt + reord + N */
+ RACK_OPTS_INC(tcp_rack_pkt_delay);
+ rack->r_ctl.rc_pkt_delay = optval;
+ break;
+ case TCP_RACK_TLP_INC_VAR:
+ /* Does TLP include rtt variance in t-o */
+ RACK_OPTS_INC(tcp_rack_tlp_inc_var);
+ rack->r_ctl.rc_prr_inc_var = optval;
+ break;
+ case TCP_RACK_IDLE_REDUCE_HIGH:
+ RACK_OPTS_INC(tcp_rack_idle_reduce_high);
+ if (optval)
+ rack->r_idle_reduce_largest = 1;
+ else
+ rack->r_idle_reduce_largest = 0;
+ break;
+ case TCP_DELACK:
+ if (optval == 0)
+ tp->t_delayed_ack = 0;
+ else
+ tp->t_delayed_ack = 1;
+ if (tp->t_flags & TF_DELACK) {
+ tp->t_flags &= ~TF_DELACK;
+ tp->t_flags |= TF_ACKNOW;
+ rack_output(tp);
+ }
+ break;
+ case TCP_RACK_MIN_PACE:
+ RACK_OPTS_INC(tcp_rack_min_pace);
+ if (optval > 3)
+ rack->r_enforce_min_pace = 3;
+ else
+ rack->r_enforce_min_pace = optval;
+ break;
+ case TCP_RACK_MIN_PACE_SEG:
+ RACK_OPTS_INC(tcp_rack_min_pace_seg);
+ if (optval >= 16)
+ rack->r_min_pace_seg_thresh = 15;
+ else
+ rack->r_min_pace_seg_thresh = optval;
+ break;
+ case TCP_BBR_RACK_RTT_USE:
+ if ((optval != USE_RTT_HIGH) &&
+ (optval != USE_RTT_LOW) &&
+ (optval != USE_RTT_AVG))
+ error = EINVAL;
+ else
+ rack->r_ctl.rc_rate_sample_method = optval;
+ break;
+ case TCP_DATA_AFTER_CLOSE:
+ if (optval)
+ rack->rc_allow_data_af_clo = 1;
+ else
+ rack->rc_allow_data_af_clo = 0;
+ break;
+ default:
+ return (tcp_default_ctloutput(so, sopt, inp, tp));
+ break;
+ }
+#ifdef NETFLIX_STATS
+ tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
+#endif
+ INP_WUNLOCK(inp);
+ return (error);
+}
+
+static int
+rack_get_sockopt(struct socket *so, struct sockopt *sopt,
+ struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
+{
+ int32_t error, optval;
+
+ /*
+ * Because all our options are either boolean or an int, we can just
+ * pull everything into optval and then unlock and copy. If we ever
+ * add a option that is not a int, then this will have quite an
+ * impact to this routine.
+ */
+ switch (sopt->sopt_name) {
+ case TCP_RACK_PROP_RATE:
+ optval = rack->r_ctl.rc_prop_rate;
+ break;
+ case TCP_RACK_PROP:
+ /* RACK proportional rate reduction (bool) */
+ optval = rack->r_ctl.rc_prop_reduce;
+ break;
+ case TCP_RACK_TLP_REDUCE:
+ /* RACK TLP cwnd reduction (bool) */
+ optval = rack->r_ctl.rc_tlp_cwnd_reduce;
+ break;
+ case TCP_RACK_EARLY_RECOV:
+ /* Should recovery happen early (bool) */
+ optval = rack->r_ctl.rc_early_recovery;
+ break;
+ case TCP_RACK_PACE_REDUCE:
+ /* RACK Hptsi reduction factor (divisor) */
+ optval = rack->rc_pace_reduce;
+ break;
+ case TCP_RACK_PACE_MAX_SEG:
+ /* Max segments in a pace */
+ optval = rack->rc_pace_max_segs;
+ break;
+ case TCP_RACK_PACE_ALWAYS:
+ /* Use the always pace method */
+ optval = rack->rc_always_pace;
+ break;
+ case TCP_RACK_PRR_SENDALOT:
+ /* Allow PRR to send more than one seg */
+ optval = rack->r_ctl.rc_prr_sendalot;
+ break;
+ case TCP_RACK_MIN_TO:
+ /* Minimum time between rack t-o's in ms */
+ optval = rack->r_ctl.rc_min_to;
+ break;
+ case TCP_RACK_EARLY_SEG:
+ /* If early recovery max segments */
+ optval = rack->r_ctl.rc_early_recovery_segs;
+ break;
+ case TCP_RACK_REORD_THRESH:
+ /* RACK reorder threshold (shift amount) */
+ optval = rack->r_ctl.rc_reorder_shift;
+ break;
+ case TCP_RACK_REORD_FADE:
+ /* Does reordering fade after ms time */
+ optval = rack->r_ctl.rc_reorder_fade;
+ break;
+ case TCP_RACK_TLP_THRESH:
+ /* RACK TLP theshold i.e. srtt+(srtt/N) */
+ optval = rack->r_ctl.rc_tlp_threshold;
+ break;
+ case TCP_RACK_PKT_DELAY:
+ /* RACK added ms i.e. rack-rtt + reord + N */
+ optval = rack->r_ctl.rc_pkt_delay;
+ break;
+ case TCP_RACK_TLP_USE:
+ optval = rack->rack_tlp_threshold_use;
+ break;
+ case TCP_RACK_TLP_INC_VAR:
+ /* Does TLP include rtt variance in t-o */
+ optval = rack->r_ctl.rc_prr_inc_var;
+ break;
+ case TCP_RACK_IDLE_REDUCE_HIGH:
+ optval = rack->r_idle_reduce_largest;
+ break;
+ case TCP_RACK_MIN_PACE:
+ optval = rack->r_enforce_min_pace;
+ break;
+ case TCP_RACK_MIN_PACE_SEG:
+ optval = rack->r_min_pace_seg_thresh;
+ break;
+ case TCP_BBR_RACK_RTT_USE:
+ optval = rack->r_ctl.rc_rate_sample_method;
+ break;
+ case TCP_DELACK:
+ optval = tp->t_delayed_ack;
+ break;
+ case TCP_DATA_AFTER_CLOSE:
+ optval = rack->rc_allow_data_af_clo;
+ break;
+ default:
+ return (tcp_default_ctloutput(so, sopt, inp, tp));
+ break;
+ }
+ INP_WUNLOCK(inp);
+ error = sooptcopyout(sopt, &optval, sizeof optval);
+ return (error);
+}
+
+static int
+rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
+{
+ int32_t error = EINVAL;
+ struct tcp_rack *rack;
+
+ rack = (struct tcp_rack *)tp->t_fb_ptr;
+ if (rack == NULL) {
+ /* Huh? */
+ goto out;
+ }
+ if (sopt->sopt_dir == SOPT_SET) {
+ return (rack_set_sockopt(so, sopt, inp, tp, rack));
+ } else if (sopt->sopt_dir == SOPT_GET) {
+ return (rack_get_sockopt(so, sopt, inp, tp, rack));
+ }
+out:
+ INP_WUNLOCK(inp);
+ return (error);
+}
+
+
+struct tcp_function_block __tcp_rack = {
+ .tfb_tcp_block_name = __XSTRING(STACKNAME),
+ .tfb_tcp_output = rack_output,
+ .tfb_tcp_do_segment = rack_do_segment,
+ .tfb_tcp_hpts_do_segment = rack_hpts_do_segment,
+ .tfb_tcp_ctloutput = rack_ctloutput,
+ .tfb_tcp_fb_init = rack_init,
+ .tfb_tcp_fb_fini = rack_fini,
+ .tfb_tcp_timer_stop_all = rack_stopall,
+ .tfb_tcp_timer_activate = rack_timer_activate,
+ .tfb_tcp_timer_active = rack_timer_active,
+ .tfb_tcp_timer_stop = rack_timer_stop,
+ .tfb_tcp_rexmit_tmr = rack_remxt_tmr,
+ .tfb_tcp_handoff_ok = rack_handoff_ok
+};
+
+static const char *rack_stack_names[] = {
+ __XSTRING(STACKNAME),
+#ifdef STACKALIAS
+ __XSTRING(STACKALIAS),
+#endif
+};
+
+static int
+rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
+{
+ memset(mem, 0, size);
+ return (0);
+}
+
+static void
+rack_dtor(void *mem, int32_t size, void *arg)
+{
+
+}
+
+static bool rack_mod_inited = false;
+
+static int
+tcp_addrack(module_t mod, int32_t type, void *data)
+{
+ int32_t err = 0;
+ int num_stacks;
+
+ switch (type) {
+ case MOD_LOAD:
+ rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
+ sizeof(struct rack_sendmap),
+ rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
+
+ rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
+ sizeof(struct tcp_rack),
+ rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
+
+ sysctl_ctx_init(&rack_sysctl_ctx);
+ rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
+ SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
+ OID_AUTO,
+ __XSTRING(STACKNAME),
+ CTLFLAG_RW, 0,
+ "");
+ if (rack_sysctl_root == NULL) {
+ printf("Failed to add sysctl node\n");
+ err = EFAULT;
+ goto free_uma;
+ }
+ rack_init_sysctls();
+ num_stacks = nitems(rack_stack_names);
+ err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
+ rack_stack_names, &num_stacks);
+ if (err) {
+ printf("Failed to register %s stack name for "
+ "%s module\n", rack_stack_names[num_stacks],
+ __XSTRING(MODNAME));
+ sysctl_ctx_free(&rack_sysctl_ctx);
+free_uma:
+ uma_zdestroy(rack_zone);
+ uma_zdestroy(rack_pcb_zone);
+ rack_counter_destroy();
+ printf("Failed to register rack module -- err:%d\n", err);
+ return (err);
+ }
+ rack_mod_inited = true;
+ break;
+ case MOD_QUIESCE:
+ err = deregister_tcp_functions(&__tcp_rack, true, false);
+ break;
+ case MOD_UNLOAD:
+ err = deregister_tcp_functions(&__tcp_rack, false, true);
+ if (err == EBUSY)
+ break;
+ if (rack_mod_inited) {
+ uma_zdestroy(rack_zone);
+ uma_zdestroy(rack_pcb_zone);
+ sysctl_ctx_free(&rack_sysctl_ctx);
+ rack_counter_destroy();
+ rack_mod_inited = false;
+ }
+ err = 0;
+ break;
+ default:
+ return (EOPNOTSUPP);
+ }
+ return (err);
+}
+
+static moduledata_t tcp_rack = {
+ .name = __XSTRING(MODNAME),
+ .evhand = tcp_addrack,
+ .priv = 0
+};
+
+MODULE_VERSION(MODNAME, 1);
+DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
Index: sys/netinet/tcp_stacks/rack_bbr_common.h
===================================================================
--- sys/netinet/tcp_stacks/rack_bbr_common.h
+++ sys/netinet/tcp_stacks/rack_bbr_common.h
@@ -0,0 +1,70 @@
+#ifndef __pacer_timer_h__
+#define __pacer_timer_h__
+/*-
+ * Copyright (c) 2017
+ * 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.
+ *
+ * __FBSDID("$FreeBSD$");
+ */
+/* Common defines and such used by both RACK and BBR */
+/* Special values for mss accounting array */
+#define TCP_MSS_ACCT_JUSTRET 0
+#define TCP_MSS_ACCT_SNDACK 1
+#define TCP_MSS_ACCT_PERSIST 2
+#define TCP_MSS_ACCT_ATIMER 60
+#define TCP_MSS_ACCT_INPACE 61
+#define TCP_MSS_ACCT_LATE 62
+#define TCP_MSS_SMALL_SIZE_OFF 63 /* Point where small sizes enter */
+#define TCP_MSS_ACCT_SIZE 70
+#define TCP_MSS_SMALL_MAX_SIZE_DIV (TCP_MSS_ACCT_SIZE - TCP_MSS_SMALL_SIZE_OFF)
+
+
+/* Magic flags to tell whats cooking on the pacing wheel */
+#define PACE_PKT_OUTPUT 0x01 /* Output Packets being paced */
+#define PACE_TMR_RACK 0x02 /* RACK timer running */
+#define PACE_TMR_TLP 0x04 /* TLP timer running */
+#define PACE_TMR_RXT 0x08 /* Retransmit timer running */
+#define PACE_TMR_PERSIT 0x10 /* Persists timer running */
+#define PACE_TMR_KEEP 0x20 /* Keep alive timer running */
+#define PACE_TMR_DELACK 0x40 /* Delayed ack timer running */
+#define PACE_TMR_MASK (PACE_TMR_KEEP|PACE_TMR_PERSIT|PACE_TMR_RXT|PACE_TMR_TLP|PACE_TMR_RACK|PACE_TMR_DELACK)
+
+/* Magic flags for tracing progress events */
+#define PROGRESS_DROP 1
+#define PROGRESS_UPDATE 2
+#define PROGRESS_CLEAR 3
+#define PROGRESS_START 4
+
+
+/* RTT sample methods */
+#define USE_RTT_HIGH 0
+#define USE_RTT_LOW 1
+#define USE_RTT_AVG 2
+
+#ifdef _KERNEL
+/* We have only 7 bits in rack so assert its true */
+CTASSERT((PACE_TMR_MASK & 0x80) == 0);
+#endif
+#endif
Index: sys/netinet/tcp_stacks/sack_filter.h
===================================================================
--- sys/netinet/tcp_stacks/sack_filter.h
+++ sys/netinet/tcp_stacks/sack_filter.h
@@ -0,0 +1,58 @@
+#ifndef __sack_filter_h__
+#define __sack_filter_h__
+/*-
+ * Copyright (c) 2017
+ * 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.
+ *
+ * __FBSDID("$FreeBSD$");
+ */
+
+/*
+ * Seven entry's is carefully choosen to
+ * fit in one cache line. We can easily
+ * change this to 15 (but it gets very
+ * little extra filtering). To change it
+ * to be larger than 15 would require either
+ * sf_bits becoming a uint32_t and then you
+ * could go to 31.. or change it to a full
+ * bitstring.. It is really doubtful you
+ * will get much benefit beyond 7, in testing
+ * there was a small amount but very very small.
+ */
+#define SACK_FILTER_BLOCKS 7
+
+struct sack_filter {
+ tcp_seq sf_ack;
+ uint16_t sf_bits;
+ uint8_t sf_cur;
+ uint8_t sf_used;
+ struct sackblk sf_blks[SACK_FILTER_BLOCKS];
+};
+#ifdef _KERNEL
+void sack_filter_clear(struct sack_filter *sf, tcp_seq seq);
+int sack_filter_blks(struct sack_filter *sf, struct sackblk *in, int numblks, tcp_seq th_ack);
+
+#endif
+#endif
Index: sys/netinet/tcp_stacks/sack_filter.c
===================================================================
--- sys/netinet/tcp_stacks/sack_filter.c
+++ sys/netinet/tcp_stacks/sack_filter.c
@@ -0,0 +1,706 @@
+/*-
+ * Copyright (c) 2017
+ * 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.
+ *
+ */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/socket.h>
+#include <sys/mbuf.h>
+#include <sys/sockopt.h>
+#include <netinet/tcp.h>
+#include <netinet/tcp_var.h>
+#include <netinet/tcp_seq.h>
+#ifndef _KERNEL
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <strings.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <getopt.h>
+#endif
+#include "sack_filter.h"
+
+/*
+ * Sack filter is used to filter out sacks
+ * that have already been processed. The idea
+ * is pretty simple really, consider two sacks
+ *
+ * SACK 1
+ * cum-ack A
+ * sack B - C
+ * SACK 2
+ * cum-ack A
+ * sack D - E
+ * sack B - C
+ *
+ * The previous sack information (B-C) is repeated
+ * in SACK 2. If the receiver gets SACK 1 and then
+ * SACK 2 then any work associated with B-C as already
+ * been completed. This only effects where we may have
+ * (as in bbr or rack) cases where we walk a linked list.
+ *
+ * Now the utility trys to keep everything in a single
+ * cache line. This means that its not perfect and
+ * it could be that so big of sack's come that a
+ * "remembered" processed sack falls off the list and
+ * so gets re-processed. Thats ok, it just means we
+ * did some extra work. We could of course take more
+ * cache line hits by expanding the size of this
+ * structure, but then that would cost more.
+ */
+
+#ifndef _KERNEL
+int detailed_dump = 0;
+uint64_t cnt_skipped_oldsack = 0;
+uint64_t cnt_used_oldsack = 0;
+int highest_used=0;
+int over_written=0;
+int empty_avail=0;
+int no_collapse = 0;
+FILE *out = NULL;
+FILE *in = NULL;
+#endif
+
+#define sack_blk_used(sf, i) ((1 << i) & sf->sf_bits)
+#define sack_blk_set(sf, i) ((1 << i) | sf->sf_bits)
+#define sack_blk_clr(sf, i) (~(1 << i) & sf->sf_bits)
+
+#ifndef _KERNEL
+static
+#endif
+void
+sack_filter_clear(struct sack_filter *sf, tcp_seq seq)
+{
+ sf->sf_ack = seq;
+ sf->sf_bits = 0;
+ sf->sf_cur = 0;
+ sf->sf_used = 0;
+}
+/*
+ * Given a previous sack filter block, filter out
+ * any entries where the cum-ack moves over them
+ * fully or partially.
+ */
+static void
+sack_filter_prune(struct sack_filter *sf, tcp_seq th_ack)
+{
+ int32_t i;
+ /* start with the oldest */
+ for (i = 0; i < SACK_FILTER_BLOCKS; i++) {
+ if (sack_blk_used(sf, i)) {
+ if (SEQ_GT(th_ack, sf->sf_blks[i].end)) {
+ /* This block is consumed */
+ sf->sf_bits = sack_blk_clr(sf, i);
+ sf->sf_used--;
+ } else if (SEQ_GT(th_ack, sf->sf_blks[i].start)) {
+ /* Some of it is acked */
+ sf->sf_blks[i].start = th_ack;
+ /* We could in theory break here, but
+ * there are some broken implementations
+ * that send multiple blocks. We want
+ * to catch them all with similar seq's.
+ */
+ }
+ }
+ }
+ sf->sf_ack = th_ack;
+}
+
+/*
+ * Return true if you find that
+ * the sackblock b is on the score
+ * board. Update it along the way
+ * if part of it is on the board.
+ */
+static int32_t
+is_sack_on_board(struct sack_filter *sf, struct sackblk *b)
+{
+ int32_t i, cnt;
+ for (i = sf->sf_cur, cnt=0; cnt < SACK_FILTER_BLOCKS; cnt++) {
+ if (sack_blk_used(sf, i)) {
+ if (SEQ_LT(b->start, sf->sf_ack)) {
+ /* Behind cum-ack update */
+ b->start = sf->sf_ack;
+ }
+ if (SEQ_LT(b->end, sf->sf_ack)) {
+ /* End back behind too */
+ b->end = sf->sf_ack;
+ }
+ if (b->start == b->end)
+ return(1);
+ /* Jonathans Rule 1 */
+ if (SEQ_LEQ(sf->sf_blks[i].start, b->start) &&
+ SEQ_GEQ(sf->sf_blks[i].end, b->end)) {
+ /**
+ * Our board has this entirely in
+ * whole or in part:
+ *
+ * board |-------------|
+ * sack |-------------|
+ * <or>
+ * board |-------------|
+ * sack |----|
+ *
+ */
+ return(1);
+ }
+ /* Jonathans Rule 2 */
+ if(SEQ_LT(sf->sf_blks[i].end, b->start)) {
+ /**
+ * Not near each other:
+ *
+ * board |---|
+ * sack |---|
+ */
+ goto nxt_blk;
+ }
+ /* Jonathans Rule 3 */
+ if (SEQ_GT(sf->sf_blks[i].start, b->end)) {
+ /**
+ * Not near each other:
+ *
+ * board |---|
+ * sack |---|
+ */
+ goto nxt_blk;
+ }
+ if (SEQ_LEQ(sf->sf_blks[i].start, b->start)) {
+ /**
+ * The board block partial meets:
+ *
+ * board |--------|
+ * sack |----------|
+ * <or>
+ * board |--------|
+ * sack |--------------|
+ *
+ * up with this one (we have part of it).
+ * 1) Update the board block to the new end
+ * and
+ * 2) Update the start of this block to my end.
+ */
+ b->start = sf->sf_blks[i].end;
+ sf->sf_blks[i].end = b->end;
+ goto nxt_blk;
+ }
+ if (SEQ_GEQ(sf->sf_blks[i].end, b->end)) {
+ /**
+ * The board block partial meets:
+ *
+ * board |--------|
+ * sack |----------|
+ * <or>
+ * board |----|
+ * sack |----------|
+ * 1) Update the board block to the new start
+ * and
+ * 2) Update the start of this block to my end.
+ */
+ b->end = sf->sf_blks[i].start;
+ sf->sf_blks[i].start = b->start;
+ goto nxt_blk;
+ }
+ }
+ nxt_blk:
+ i++;
+ i %= SACK_FILTER_BLOCKS;
+ }
+ /* Did we totally consume it in pieces? */
+ if (b->start != b->end)
+ return(0);
+ else
+ return(1);
+}
+
+static int32_t
+sack_filter_old(struct sack_filter *sf, struct sackblk *in, int numblks)
+{
+ int32_t num, i;
+ struct sackblk blkboard[TCP_MAX_SACK];
+ /*
+ * An old sack has arrived. It may contain data
+ * we do not have. We might not have it since
+ * we could have had a lost ack <or> we might have the
+ * entire thing on our current board. We want to prune
+ * off anything we have. With this function though we
+ * won't add to the board.
+ */
+ for( i = 0, num = 0; i<numblks; i++ ) {
+ if (is_sack_on_board(sf, &in[i])) {
+#ifndef _KERNEL
+ cnt_skipped_oldsack++;
+#endif
+ continue;
+ }
+ /* Did not find it (or found only
+ * a piece of it). Copy it to
+ * our outgoing board.
+ */
+ memcpy(&blkboard[num], &in[i], sizeof(struct sackblk));
+#ifndef _KERNEL
+ cnt_used_oldsack++;
+#endif
+ num++;
+ }
+ if (num) {
+ memcpy(in, blkboard, (num * sizeof(struct sackblk)));
+ }
+ return (num);
+}
+
+/*
+ * Given idx its used but there is space available
+ * move the entry to the next free slot
+ */
+static void
+sack_move_to_empty(struct sack_filter *sf, uint32_t idx)
+{
+ int32_t i, cnt;
+
+ i = (idx + 1) % SACK_FILTER_BLOCKS;
+ for (cnt=0; cnt <(SACK_FILTER_BLOCKS-1); cnt++) {
+ if (sack_blk_used(sf, i) == 0) {
+ memcpy(&sf->sf_blks[i], &sf->sf_blks[idx], sizeof(struct sackblk));
+ sf->sf_bits = sack_blk_clr(sf, idx);
+ sf->sf_bits = sack_blk_set(sf, i);
+ return;
+ }
+ i++;
+ i %= SACK_FILTER_BLOCKS;
+ }
+}
+
+static int32_t
+sack_filter_new(struct sack_filter *sf, struct sackblk *in, int numblks, tcp_seq th_ack)
+{
+ struct sackblk blkboard[TCP_MAX_SACK];
+ int32_t num, i;
+ /*
+ * First lets trim the old and possibly
+ * throw any away we have.
+ */
+ for(i=0, num=0; i<numblks; i++) {
+ if (is_sack_on_board(sf, &in[i]))
+ continue;
+ memcpy(&blkboard[num], &in[i], sizeof(struct sackblk));
+ num++;
+ }
+ if (num == 0)
+ return(num);
+
+ /* Now what we are left is either
+ * completely merged on to the board
+ * from the above steps, or are new
+ * and need to be added to the board
+ * with the last one updated to current.
+ *
+ * First copy it out we want to return that
+ * to our caller for processing.
+ */
+ memcpy(in, blkboard, (num * sizeof(struct sackblk)));
+ numblks = num;
+ /* Now go through and add to our board as needed */
+ for(i=(num-1); i>=0; i--) {
+ if (is_sack_on_board(sf, &blkboard[i]))
+ continue;
+ /* Add this guy its not listed */
+ sf->sf_cur++;
+ sf->sf_cur %= SACK_FILTER_BLOCKS;
+ if ((sack_blk_used(sf, sf->sf_cur)) &&
+ (sf->sf_used < SACK_FILTER_BLOCKS)) {
+ sack_move_to_empty(sf, sf->sf_cur);
+ }
+#ifndef _KERNEL
+ if (sack_blk_used(sf, sf->sf_cur)) {
+ over_written++;
+ if (sf->sf_used < SACK_FILTER_BLOCKS)
+ empty_avail++;
+ }
+#endif
+ memcpy(&sf->sf_blks[sf->sf_cur], &in[i], sizeof(struct sackblk));
+ if (sack_blk_used(sf, sf->sf_cur) == 0) {
+ sf->sf_used++;
+#ifndef _KERNEL
+ if (sf->sf_used > highest_used)
+ highest_used = sf->sf_used;
+#endif
+ sf->sf_bits = sack_blk_set(sf, sf->sf_cur);
+ }
+ }
+ return(numblks);
+}
+
+/*
+ * Given a sack block on the board (the skip index) see if
+ * any other used entries overlap or meet, if so return the index.
+ */
+static int32_t
+sack_blocks_overlap_or_meet(struct sack_filter *sf, struct sackblk *sb, uint32_t skip)
+{
+ int32_t i;
+
+ for(i=0; i<SACK_FILTER_BLOCKS; i++) {
+ if (sack_blk_used(sf, i) == 0)
+ continue;
+ if (i == skip)
+ continue;
+ if (SEQ_GEQ(sf->sf_blks[i].end, sb->start) &&
+ SEQ_LEQ(sf->sf_blks[i].end, sb->end) &&
+ SEQ_LEQ(sf->sf_blks[i].start, sb->start)) {
+ /**
+ * The two board blocks meet:
+ *
+ * board1 |--------|
+ * board2 |----------|
+ * <or>
+ * board1 |--------|
+ * board2 |--------------|
+ * <or>
+ * board1 |--------|
+ * board2 |--------|
+ */
+ return(i);
+ }
+ if (SEQ_LEQ(sf->sf_blks[i].start, sb->end) &&
+ SEQ_GEQ(sf->sf_blks[i].start, sb->start) &&
+ SEQ_GEQ(sf->sf_blks[i].end, sb->end)) {
+ /**
+ * The board block partial meets:
+ *
+ * board |--------|
+ * sack |----------|
+ * <or>
+ * board |----|
+ * sack |----------|
+ * 1) Update the board block to the new start
+ * and
+ * 2) Update the start of this block to my end.
+ */
+ return(i);
+ }
+ }
+ return (-1);
+}
+
+/*
+ * Collapse entry src into entry into
+ * and free up the src entry afterwards.
+ */
+static void
+sack_collapse(struct sack_filter *sf, int32_t src, int32_t into)
+{
+ if (SEQ_LT(sf->sf_blks[src].start, sf->sf_blks[into].start)) {
+ /* src has a lower starting point */
+ sf->sf_blks[into].start = sf->sf_blks[src].start;
+ }
+ if (SEQ_GT(sf->sf_blks[src].end, sf->sf_blks[into].end)) {
+ /* src has a higher ending point */
+ sf->sf_blks[into].end = sf->sf_blks[src].end;
+ }
+ sf->sf_bits = sack_blk_clr(sf, src);
+ sf->sf_used--;
+}
+
+static void
+sack_board_collapse(struct sack_filter *sf)
+{
+ int32_t i, j, i_d, j_d;
+
+ for(i=0; i<SACK_FILTER_BLOCKS; i++) {
+ if (sack_blk_used(sf, i) == 0)
+ continue;
+ /*
+ * Look at all other blocks but this guy
+ * to see if they overlap. If so we collapse
+ * the two blocks together.
+ */
+ j = sack_blocks_overlap_or_meet(sf, &sf->sf_blks[i], i);
+ if (j == -1) {
+ /* No overlap */
+ continue;
+ }
+ /*
+ * Ok j and i overlap with each other, collapse the
+ * one out furthest away from the current position.
+ */
+ if (sf->sf_cur > i)
+ i_d = sf->sf_cur - i;
+ else
+ i_d = i - sf->sf_cur;
+ if (sf->sf_cur > j)
+ j_d = sf->sf_cur - j;
+ else
+ j_d = j - sf->sf_cur;
+ if (j_d > i_d) {
+ sack_collapse(sf, j, i);
+ } else
+ sack_collapse(sf, i, j);
+ }
+}
+
+#ifndef _KERNEL
+static
+#endif
+int
+sack_filter_blks(struct sack_filter *sf, struct sackblk *in, int numblks, tcp_seq th_ack)
+{
+ int32_t i, ret;
+
+ if (numblks > TCP_MAX_SACK) {
+ panic("sf:%p sb:%p Impossible number of sack blocks %d > 4\n",
+ sf, in,
+ numblks);
+ return(numblks);
+ }
+ if ((sf->sf_used == 0) && numblks) {
+ /*
+ * We are brand new add the blocks in
+ * reverse order. Note we can see more
+ * than one in new, since ack's could be lost.
+ */
+ sf->sf_ack = th_ack;
+ for(i=(numblks-1), sf->sf_cur=0; i >= 0; i--) {
+ memcpy(&sf->sf_blks[sf->sf_cur], &in[i], sizeof(struct sackblk));
+ sf->sf_bits = sack_blk_set(sf, sf->sf_cur);
+ sf->sf_cur++;
+ sf->sf_cur %= SACK_FILTER_BLOCKS;
+ sf->sf_used++;
+#ifndef _KERNEL
+ if (sf->sf_used > highest_used)
+ highest_used = sf->sf_used;
+#endif
+ }
+ if (sf->sf_cur)
+ sf->sf_cur--;
+ return(numblks);
+ }
+ if (SEQ_GT(th_ack, sf->sf_ack)) {
+ sack_filter_prune(sf, th_ack);
+ }
+ if (numblks) {
+ if (SEQ_GEQ(th_ack, sf->sf_ack)) {
+ ret = sack_filter_new(sf, in, numblks, th_ack);
+ } else {
+ ret = sack_filter_old(sf, in, numblks);
+ }
+ } else
+ ret = 0;
+#ifndef _KERNEL
+ if ((sf->sf_used > 1) && (no_collapse == 0))
+ sack_board_collapse(sf);
+
+#else
+ if (sf->sf_used > 1)
+ sack_board_collapse(sf);
+
+#endif
+ return (ret);
+}
+
+#ifndef _KERNEL
+uint64_t saved=0;
+uint64_t tot_sack_blks=0;
+
+static void
+sack_filter_dump(FILE *out, struct sack_filter *sf)
+{
+ int i;
+ fprintf(out, " sf_ack:%u sf_bits:0x%x c:%d used:%d\n",
+ sf->sf_ack, sf->sf_bits,
+ sf->sf_cur, sf->sf_used);
+
+ for(i=0; i<SACK_FILTER_BLOCKS; i++) {
+ if (sack_blk_used(sf, i)) {
+ fprintf(out, "Entry:%d start:%u end:%u\n", i,
+ sf->sf_blks[i].start,
+ sf->sf_blks[i].end);
+ }
+ }
+}
+
+int
+main(int argc, char **argv)
+{
+ char buffer[512];
+ struct sackblk blks[TCP_MAX_SACK];
+ FILE *err;
+ tcp_seq th_ack, snd_una;
+ struct sack_filter sf;
+ int32_t numblks,i;
+ int snd_una_set=0;
+ double a, b, c;
+ int invalid_sack_print = 0;
+ uint32_t chg_remembered=0;
+ uint32_t sack_chg=0;
+ char line_buf[10][256];
+ int line_buf_at=0;
+
+ in = stdin;
+ out = stdout;
+ while ((i = getopt(argc, argv, "ndIi:o:?h")) != -1) {
+ switch (i) {
+ case 'n':
+ no_collapse = 1;
+ break;
+ case 'd':
+ detailed_dump = 1;
+ break;
+ case'I':
+ invalid_sack_print = 1;
+ break;
+ case 'i':
+ in = fopen(optarg, "r");
+ if (in == NULL) {
+ fprintf(stderr, "Fatal error can't open %s for input\n", optarg);
+ exit(-1);
+ }
+ break;
+ case 'o':
+ out = fopen(optarg, "w");
+ if (out == NULL) {
+ fprintf(stderr, "Fatal error can't open %s for output\n", optarg);
+ exit(-1);
+ }
+ break;
+ default:
+ case '?':
+ case 'h':
+ fprintf(stderr, "Use %s [ -i infile -o outfile -I]\n", argv[0]);
+ return(0);
+ break;
+ };
+ }
+ sack_filter_clear(&sf, 0);
+ memset(buffer, 0, sizeof(buffer));
+ memset(blks, 0, sizeof(blks));
+ numblks = 0;
+ fprintf(out, "************************************\n");
+ while (fgets(buffer, sizeof(buffer), in) != NULL) {
+ sprintf(line_buf[line_buf_at], "%s", buffer);
+ line_buf_at++;
+ if (strncmp(buffer, "QUIT", 4) == 0) {
+ break;
+ } else if (strncmp(buffer, "DONE", 4) == 0) {
+ int nn, ii;
+ if (numblks) {
+ uint32_t szof, tot_chg;
+ for(ii=0; ii<line_buf_at; ii++) {
+ fprintf(out, "%s", line_buf[ii]);
+ }
+ fprintf(out, "------------------------------------\n");
+ nn = sack_filter_blks(&sf, blks, numblks, th_ack);
+ saved += numblks - nn;
+ tot_sack_blks += numblks;
+ fprintf(out, "ACK:%u\n", sf.sf_ack);
+ for(ii=0, tot_chg=0; ii<nn; ii++) {
+ szof = blks[ii].end - blks[ii].start;
+ tot_chg += szof;
+ fprintf(out, "SACK:%u:%u [%u]\n",
+ blks[ii].start,
+ blks[ii].end, szof);
+ }
+ fprintf(out,"************************************\n");
+ chg_remembered = tot_chg;
+ if (detailed_dump) {
+ sack_filter_dump(out, &sf);
+ fprintf(out,"************************************\n");
+ }
+ }
+ memset(blks, 0, sizeof(blks));
+ memset(line_buf, 0, sizeof(line_buf));
+ line_buf_at=0;
+ numblks = 0;
+ } else if (strncmp(buffer, "CHG:", 4) == 0) {
+ sack_chg = strtoul(&buffer[4], NULL, 0);
+ if ((sack_chg != chg_remembered) &&
+ (sack_chg > chg_remembered)){
+ fprintf(out,"***WARNING WILL RODGERS DANGER!! sack_chg:%u last:%u\n",
+ sack_chg, chg_remembered
+ );
+ }
+ sack_chg = chg_remembered = 0;
+ } else if (strncmp(buffer, "RXT", 3) == 0) {
+ sack_filter_clear(&sf, snd_una);
+ } else if (strncmp(buffer, "ACK:", 4) == 0) {
+ th_ack = strtoul(&buffer[4], NULL, 0);
+ if (snd_una_set == 0) {
+ snd_una = th_ack;
+ snd_una_set = 1;
+ } else if (SEQ_GT(th_ack, snd_una)) {
+ snd_una = th_ack;
+ }
+ } else if (strncmp(buffer, "EXIT", 4) == 0) {
+ sack_filter_clear(&sf, snd_una);
+ sack_chg = chg_remembered = 0;
+ } else if (strncmp(buffer, "SACK:", 5) == 0) {
+ char *end=NULL;
+ uint32_t start;
+ uint32_t endv;
+ start = strtoul(&buffer[5], &end, 0);
+ if (end) {
+ endv = strtoul(&end[1], NULL, 0);
+ } else {
+ fprintf(out, "--Sack invalid skip 0 start:%u : ??\n", start);
+ continue;
+ }
+ if (SEQ_LT(endv, start)) {
+ fprintf(out, "--Sack invalid skip 1 endv:%u < start:%u\n", endv, start);
+ continue;
+ }
+ if (numblks == TCP_MAX_SACK) {
+ fprintf(out, "--Exceeded max %d\n", numblks);
+ exit(0);
+ }
+ blks[numblks].start = start;
+ blks[numblks].end = endv;
+ numblks++;
+ }
+ memset(buffer, 0, sizeof(buffer));
+ }
+ if (in != stdin) {
+ fclose(in);
+ }
+ if (out != stdout) {
+ fclose(out);
+ }
+ a = saved * 100.0;
+ b = tot_sack_blks * 1.0;
+ if (b > 0.0)
+ c = a/b;
+ else
+ c = 0.0;
+ if (out != stdout)
+ err = stdout;
+ else
+ err = stderr;
+ fprintf(err, "Saved %lu sack blocks out of %lu (%2.3f%%) old_skip:%lu old_usd:%lu high_cnt:%d ow:%d ea:%d\n",
+ saved, tot_sack_blks, c, cnt_skipped_oldsack, cnt_used_oldsack, highest_used, over_written, empty_avail);
+ return(0);
+}
+#endif
Index: sys/netinet/tcp_stacks/tcp_rack.h
===================================================================
--- sys/netinet/tcp_stacks/tcp_rack.h
+++ sys/netinet/tcp_stacks/tcp_rack.h
@@ -0,0 +1,321 @@
+/*-
+ * Copyright (c) 2016
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _NETINET_TCP_RACK_H_
+#define _NETINET_TCP_RACK_H_
+
+#define RACK_ACKED 0x0001/* The remote endpoint acked this */
+#define RACK_TO_MIXED 0x0002/* A timeout occured that mixed the send order */
+#define RACK_DEFERRED 0x0004/* We can't use this for RTT calc */
+#define RACK_OVERMAX 0x0008/* We have more retran's then we can fit */
+#define RACK_SACK_PASSED 0x0010/* A sack was done above this block */
+#define RACK_WAS_SACKPASS 0x0020/* We retransmitted due to SACK pass */
+#define RACK_HAS_FIN 0x0040/* segment is sent with fin */
+#define RACK_TLP 0x0080/* segment sent as tail-loss-probe */
+
+#define RACK_NUM_OF_RETRANS 3
+
+#define RACK_INITIAL_RTO 1000 /* 1 second in milli seconds */
+
+struct rack_sendmap {
+ TAILQ_ENTRY(rack_sendmap) r_next; /* seq number arrayed next */
+ TAILQ_ENTRY(rack_sendmap) r_tnext; /* Time of transmit based next */
+ uint32_t r_tim_lastsent[RACK_NUM_OF_RETRANS];
+ uint32_t r_start; /* Sequence number of the segment */
+ uint32_t r_end; /* End seq, this is 1 beyond actually */
+ uint32_t r_rtr_bytes; /* How many bytes have been retransmitted */
+ uint16_t r_rtr_cnt; /* Retran count, index this -1 to get time
+ * sent */
+ uint8_t r_flags; /* Flags as defined above */
+ uint8_t r_sndcnt; /* Retran count, not limited by
+ * RACK_NUM_OF_RETRANS */
+ uint8_t r_in_tmap; /* Flag to see if its in the r_tnext array */
+ uint8_t r_resv[3];
+};
+
+TAILQ_HEAD(rack_head, rack_sendmap);
+
+
+/*
+ * We use the rate sample structure to
+ * assist in single sack/ack rate and rtt
+ * calculation. In the future we will expand
+ * this in BBR to do forward rate sample
+ * b/w estimation.
+ */
+#define RACK_RTT_EMPTY 0x00000001 /* Nothing yet stored in RTT's */
+#define RACK_RTT_VALID 0x00000002 /* We have at least one valid RTT */
+struct rack_rtt_sample {
+ uint32_t rs_flags;
+ uint32_t rs_rtt_lowest;
+ uint32_t rs_rtt_highest;
+ uint32_t rs_rtt_cnt;
+ uint64_t rs_rtt_tot;
+};
+
+#define RACK_LOG_TYPE_ACK 0x01
+#define RACK_LOG_TYPE_OUT 0x02
+#define RACK_LOG_TYPE_TO 0x03
+#define RACK_LOG_TYPE_ALLOC 0x04
+#define RACK_LOG_TYPE_FREE 0x05
+
+
+struct rack_log {
+ union {
+ struct rack_sendmap *rsm; /* For alloc/free */
+ uint64_t sb_acc;/* For out/ack or t-o */
+ };
+ uint32_t th_seq;
+ uint32_t th_ack;
+ uint32_t snd_una;
+ uint32_t snd_nxt; /* th_win for TYPE_ACK */
+ uint32_t snd_max;
+ uint32_t blk_start[4];
+ uint32_t blk_end[4];
+ uint8_t type;
+ uint8_t n_sackblks;
+ uint16_t len; /* Timeout T3=1, TLP=2, RACK=3 */
+};
+
+/*
+ * Magic numbers for logging timeout events if the
+ * logging is enabled.
+ */
+#define RACK_TO_FRM_TMR 1
+#define RACK_TO_FRM_TLP 2
+#define RACK_TO_FRM_RACK 3
+#define RACK_TO_FRM_KEEP 4
+#define RACK_TO_FRM_PERSIST 5
+#define RACK_TO_FRM_DELACK 6
+
+struct rack_opts_stats {
+ uint64_t tcp_rack_prop_rate;
+ uint64_t tcp_rack_prop;
+ uint64_t tcp_rack_tlp_reduce;
+ uint64_t tcp_rack_early_recov;
+ uint64_t tcp_rack_pace_always;
+ uint64_t tcp_rack_pace_reduce;
+ uint64_t tcp_rack_max_seg;
+ uint64_t tcp_rack_prr_sendalot;
+ uint64_t tcp_rack_min_to;
+ uint64_t tcp_rack_early_seg;
+ uint64_t tcp_rack_reord_thresh;
+ uint64_t tcp_rack_reord_fade;
+ uint64_t tcp_rack_tlp_thresh;
+ uint64_t tcp_rack_pkt_delay;
+ uint64_t tcp_rack_tlp_inc_var;
+ uint64_t tcp_tlp_use;
+ uint64_t tcp_rack_idle_reduce;
+ uint64_t tcp_rack_idle_reduce_high;
+ uint64_t rack_no_timer_in_hpts;
+ uint64_t tcp_rack_min_pace_seg;
+ uint64_t tcp_rack_min_pace;
+};
+
+#define TLP_USE_ID 1 /* Internet draft behavior */
+#define TLP_USE_TWO_ONE 2 /* Use 2.1 behavior */
+#define TLP_USE_TWO_TWO 3 /* Use 2.2 behavior */
+
+#ifdef _KERNEL
+#define RACK_OPTS_SIZE (sizeof(struct rack_opts_stats)/sizeof(uint64_t))
+extern counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
+#define RACK_OPTS_ADD(name, amm) counter_u64_add(rack_opts_arry[(offsetof(struct rack_opts_stats, name)/sizeof(uint64_t))], (amm))
+#define RACK_OPTS_INC(name) RACK_OPTS_ADD(name, 1)
+#endif
+/*
+ * As we get each SACK we wade through the
+ * rc_map and mark off what is acked.
+ * We also increment rc_sacked as well.
+ *
+ * We also pay attention to missing entries
+ * based on the time and possibly mark them
+ * for retransmit. If we do and we are not already
+ * in recovery we enter recovery. In doing
+ * so we claer prr_delivered/holes_rxt and prr_sent_dur_rec.
+ * We also setup rc_next/rc_snd_nxt/rc_send_end so
+ * we will know where to send from. When not in
+ * recovery rc_next will be NULL and rc_snd_nxt should
+ * equal snd_max.
+ *
+ * Whenever we retransmit from recovery we increment
+ * rc_holes_rxt as we retran a block and mark it as retransmitted
+ * with the time it was sent. During non-recovery sending we
+ * add to our map and note the time down of any send expanding
+ * the rc_map at the tail and moving rc_snd_nxt up with snd_max.
+ *
+ * In recovery during SACK/ACK processing if a chunk has
+ * been retransmitted and it is now acked, we decrement rc_holes_rxt.
+ * When we retransmit from the scoreboard we use
+ * rc_next and rc_snd_nxt/rc_send_end to help us
+ * find what needs to be retran.
+ *
+ * To calculate pipe we simply take (snd_max - snd_una) + rc_holes_rxt
+ * This gets us the effect of RFC6675 pipe, counting twice for
+ * bytes retransmitted.
+ */
+
+#define TT_RACK_FR_TMR 0x2000
+
+/*
+ * Locking for the rack control block.
+ * a) Locked by INP_WLOCK
+ * b) Locked by the hpts-mutex
+ *
+ */
+
+struct rack_control {
+ /* Second cache line 0x40 from tcp_rack */
+ struct rack_head rc_map;/* List of all segments Lock(a) */
+ struct rack_head rc_tmap; /* List in transmit order Lock(a) */
+ struct rack_sendmap *rc_tlpsend; /* Remembered place for
+ * tlp_sending Lock(a) */
+ struct rack_sendmap *rc_resend; /* something we have been asked to
+ * resend */
+ uint32_t rc_hpts_flags;
+ uint32_t rc_timer_exp; /* If a timer ticks of expiry */
+ uint32_t rc_rack_min_rtt; /* lowest RTT seen Lock(a) */
+ uint32_t rc_rack_largest_cwnd; /* Largest CWND we have seen Lock(a) */
+
+ /* Third Cache line 0x80 */
+ struct rack_head rc_free; /* Allocation array */
+ uint32_t rc_time_last_sent; /* Time we last sent some data and
+ * logged it Lock(a). */
+ uint32_t rc_reorder_ts; /* Last time we saw reordering Lock(a) */
+
+ uint32_t rc_tlp_new_data; /* we need to send new-data on a TLP
+ * Lock(a) */
+ uint32_t rc_prr_out; /* bytes sent during recovery Lock(a) */
+
+ uint32_t rc_prr_recovery_fs; /* recovery fs point Lock(a) */
+
+ uint32_t rc_prr_sndcnt; /* Prr sndcnt Lock(a) */
+
+ uint32_t rc_sacked; /* Tot sacked on scoreboard Lock(a) */
+ uint32_t rc_last_tlp_seq; /* Last tlp sequence Lock(a) */
+
+ uint32_t rc_prr_delivered; /* during recovery prr var Lock(a) */
+ uint16_t rc_tlp_send_cnt; /* Number of TLP sends we have done
+ * since peer spoke to us Lock(a) */
+ uint16_t rc_tlp_seg_send_cnt; /* Number of times we have TLP sent
+ * rc_last_tlp_seq Lock(a) */
+
+ uint32_t rc_loss_count; /* During recovery how many segments were lost
+ * Lock(a) */
+ uint32_t rc_reorder_fade; /* Socket option value Lock(a) */
+
+ /* Forth cache line 0xc0 */
+ /* Times */
+
+ uint32_t rc_rack_tmit_time; /* Rack transmit time Lock(a) */
+ uint32_t rc_holes_rxt; /* Tot retraned from scoreboard Lock(a) */
+
+ /* Variables to track bad retransmits and recover */
+ uint32_t rc_rsm_start; /* RSM seq number we retransmitted Lock(a) */
+ uint32_t rc_cwnd_at; /* cwnd at the retransmit Lock(a) */
+
+ uint32_t rc_ssthresh_at;/* ssthresh at the retransmit Lock(a) */
+ uint32_t rc_num_maps_alloced; /* Number of map blocks (sacks) we
+ * have allocated */
+ uint32_t rc_rcvtime; /* When we last received data */
+ uint32_t rc_notused;
+ uint32_t rc_last_output_to;
+ uint32_t rc_went_idle_time;
+
+ struct rack_sendmap *rc_sacklast; /* sack remembered place
+ * Lock(a) */
+
+ struct rack_sendmap *rc_next; /* remembered place where we next
+ * retransmit at Lock(a) */
+ struct rack_sendmap *rc_rsm_at_retran; /* Debug variable kept for
+ * cache line alignment
+ * Lock(a) */
+ /* Cache line split 0x100 */
+ struct sack_filter rack_sf;
+ /* Cache line split 0x140 */
+ /* Flags for various things */
+ struct rack_rtt_sample rack_rs;
+ uint32_t rc_tlp_threshold; /* Socket option value Lock(a) */
+ uint16_t rc_early_recovery_segs; /* Socket option value Lock(a) */
+ uint16_t rc_reorder_shift; /* Socket option value Lock(a) */
+ uint16_t rc_pkt_delay; /* Socket option value Lock(a) */
+ uint8_t rc_prop_rate; /* Socket option value Lock(a) */
+ uint8_t rc_prop_reduce; /* Socket option value Lock(a) */
+ uint8_t rc_tlp_cwnd_reduce; /* Socket option value Lock(a) */
+ uint8_t rc_early_recovery; /* Socket option value Lock(a) */
+ uint8_t rc_prr_sendalot;/* Socket option value Lock(a) */
+ uint8_t rc_min_to; /* Socket option value Lock(a) */
+ uint8_t rc_prr_inc_var; /* Socket option value Lock(a) */
+ uint8_t rc_tlp_rtx_out; /* This is TLPRtxOut in the draft */
+ uint8_t rc_rate_sample_method;
+};
+
+#ifdef _KERNEL
+
+struct tcp_rack {
+ /* First cache line 0x00 */
+ TAILQ_ENTRY(tcp_rack) r_hpts; /* hptsi queue next Lock(b) */
+ int32_t(*r_substate) (struct mbuf *, struct tcphdr *,
+ struct socket *, struct tcpcb *, struct tcpopt *,
+ int32_t, int32_t, int32_t *, uint32_t, int, int); /* Lock(a) */
+ struct tcpcb *rc_tp; /* The tcpcb Lock(a) */
+ struct inpcb *rc_inp; /* The inpcb Lock(a) */
+ uint32_t rc_free_cnt; /* Number of free entries on the rc_free list
+ * Lock(a) */
+ uint32_t rc_rack_rtt; /* RACK-RTT Lock(a) */
+ uint16_t r_wanted_output; /* Output routine wanted to be called */
+ uint16_t r_cpu; /* CPU that the INP is running on Lock(a) */
+ uint16_t rc_pace_max_segs; /* Socket option value Lock(a) */
+ uint16_t rc_pace_reduce;/* Socket option value Lock(a) */
+
+ uint8_t r_state; /* Current rack state Lock(a) */
+ uint8_t rc_tmr_stopped : 7,
+ t_timers_stopped : 1;
+ uint8_t rc_enobuf; /* count of enobufs on connection provides
+ * backoff Lock(a) */
+ uint8_t r_timer_override : 1, /* hpts override Lock(a) */
+ r_tlp_running : 1, /* Running from a TLP timeout Lock(a) */
+ r_is_v6 : 1, /* V6 pcb Lock(a) */
+ rc_in_persist : 1,
+ rc_last_pto_set : 1, /* XXX not used */
+ rc_tlp_in_progress : 1,
+ rc_always_pace : 1, /* Socket option value Lock(a) */
+ rc_timer_up : 1; /* The rack timer is up flag Lock(a) */
+ uint8_t r_idle_reduce_largest : 1,
+ r_enforce_min_pace : 2,
+ r_min_pace_seg_thresh : 5;
+ uint8_t rack_tlp_threshold_use;
+ uint8_t rc_allow_data_af_clo: 1,
+ delayed_ack : 1,
+ rc_avail : 6;
+ uint8_t r_resv[2]; /* Fill to cache line boundary */
+ /* Cache line 2 0x40 */
+ struct rack_control r_ctl;
+} __aligned(CACHE_LINE_SIZE);
+
+#endif
+#endif
Index: sys/netinet/tcp_timer.h
===================================================================
--- sys/netinet/tcp_timer.h
+++ sys/netinet/tcp_timer.h
@@ -168,11 +168,15 @@
#define TT_2MSL 0x0010
#define TT_MASK (TT_DELACK|TT_REXMT|TT_PERSIST|TT_KEEP|TT_2MSL)
-#define TT_DELACK_RST 0x0100
-#define TT_REXMT_RST 0x0200
-#define TT_PERSIST_RST 0x0400
-#define TT_KEEP_RST 0x0800
-#define TT_2MSL_RST 0x1000
+/*
+ * Suspend flags - used when suspending a timer
+ * from ever running again.
+ */
+#define TT_DELACK_SUS 0x0100
+#define TT_REXMT_SUS 0x0200
+#define TT_PERSIST_SUS 0x0400
+#define TT_KEEP_SUS 0x0800
+#define TT_2MSL_SUS 0x1000
#define TT_STOPPED 0x00010000
@@ -196,6 +200,8 @@
extern int tcp_ttl; /* time to live for TCP segs */
extern int tcp_backoff[];
extern int tcp_syn_backoff[];
+extern int tcp_totbackoff;
+extern int tcp_rexmit_drop_options;
extern int tcp_always_keepalive;
extern int tcp_finwait2_timeout;
Index: sys/netinet/tcp_timer.c
===================================================================
--- sys/netinet/tcp_timer.c
+++ sys/netinet/tcp_timer.c
@@ -71,6 +71,7 @@
#include <netinet/tcp_log_buf.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
+#include <netinet/tcp_seq.h>
#include <netinet/cc/cc.h>
#ifdef INET6
#include <netinet6/tcp6_var.h>
@@ -139,7 +140,7 @@
/* max idle probes */
int tcp_maxpersistidle;
-static int tcp_rexmit_drop_options = 0;
+int tcp_rexmit_drop_options = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, rexmit_drop_options, CTLFLAG_RW,
&tcp_rexmit_drop_options, 0,
"Drop TCP options from 3rd and later retransmitted SYN");
@@ -174,11 +175,6 @@
SYSCTL_INT(_net_inet_tcp, OID_AUTO, per_cpu_timers, CTLFLAG_RW,
&per_cpu_timers , 0, "run tcp timers on all cpus");
-#if 0
-#define INP_CPU(inp) (per_cpu_timers ? (!CPU_ABSENT(((inp)->inp_flowid % (mp_maxid+1))) ? \
- ((inp)->inp_flowid % (mp_maxid+1)) : curcpu) : 0)
-#endif
-
/*
* Map the given inp to a CPU id.
*
@@ -185,7 +181,7 @@
* This queries RSS if it's compiled in, else it defaults to the current
* CPU ID.
*/
-static inline int
+inline int
inp_to_cpuid(struct inpcb *inp)
{
u_int cpuid;
@@ -243,7 +239,7 @@
int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
{ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 512, 512, 512 };
-static int tcp_totbackoff = 2559; /* sum of tcp_backoff[] */
+int tcp_totbackoff = 2559; /* sum of tcp_backoff[] */
/*
* TCP timer processing.
@@ -948,7 +944,112 @@
return callout_active(t_callout);
}
+/*
+ * Stop the timer from running, and apply a flag
+ * against the timer_flags that will force the
+ * timer never to run. The flag is needed to assure
+ * a race does not leave it running and cause
+ * the timer to possibly restart itself (keep and persist
+ * especially do this).
+ */
+int
+tcp_timer_suspend(struct tcpcb *tp, uint32_t timer_type)
+{
+ struct callout *t_callout;
+ uint32_t t_flags;
+
+ switch (timer_type) {
+ case TT_DELACK:
+ t_flags = TT_DELACK_SUS;
+ t_callout = &tp->t_timers->tt_delack;
+ break;
+ case TT_REXMT:
+ t_flags = TT_REXMT_SUS;
+ t_callout = &tp->t_timers->tt_rexmt;
+ break;
+ case TT_PERSIST:
+ t_flags = TT_PERSIST_SUS;
+ t_callout = &tp->t_timers->tt_persist;
+ break;
+ case TT_KEEP:
+ t_flags = TT_KEEP_SUS;
+ t_callout = &tp->t_timers->tt_keep;
+ break;
+ case TT_2MSL:
+ t_flags = TT_2MSL_SUS;
+ t_callout = &tp->t_timers->tt_2msl;
+ break;
+ default:
+ panic("tp:%p bad timer_type 0x%x", tp, timer_type);
+ }
+ tp->t_timers->tt_flags |= t_flags;
+ return (callout_stop(t_callout));
+}
+
void
+tcp_timers_unsuspend(struct tcpcb *tp, uint32_t timer_type)
+{
+ switch (timer_type) {
+ case TT_DELACK:
+ if (tp->t_timers->tt_flags & TT_DELACK_SUS) {
+ tp->t_timers->tt_flags &= ~TT_DELACK_SUS;
+ if (tp->t_flags & TF_DELACK) {
+ /* Delayed ack timer should be up activate a timer */
+ tp->t_flags &= ~TF_DELACK;
+ tcp_timer_activate(tp, TT_DELACK,
+ tcp_delacktime);
+ }
+ }
+ break;
+ case TT_REXMT:
+ if (tp->t_timers->tt_flags & TT_REXMT_SUS) {
+ tp->t_timers->tt_flags &= ~TT_REXMT_SUS;
+ if (SEQ_GT(tp->snd_max, tp->snd_una) &&
+ (tcp_timer_active((tp), TT_PERSIST) == 0) &&
+ tp->snd_wnd) {
+ /* We have outstanding data activate a timer */
+ tcp_timer_activate(tp, TT_REXMT,
+ tp->t_rxtcur);
+ }
+ }
+ break;
+ case TT_PERSIST:
+ if (tp->t_timers->tt_flags & TT_PERSIST_SUS) {
+ tp->t_timers->tt_flags &= ~TT_PERSIST_SUS;
+ if (tp->snd_wnd == 0) {
+ /* Activate the persists timer */
+ tp->t_rxtshift = 0;
+ tcp_setpersist(tp);
+ }
+ }
+ break;
+ case TT_KEEP:
+ if (tp->t_timers->tt_flags & TT_KEEP_SUS) {
+ tp->t_timers->tt_flags &= ~TT_KEEP_SUS;
+ tcp_timer_activate(tp, TT_KEEP,
+ TCPS_HAVEESTABLISHED(tp->t_state) ?
+ TP_KEEPIDLE(tp) : TP_KEEPINIT(tp));
+ }
+ break;
+ case TT_2MSL:
+ if (tp->t_timers->tt_flags &= TT_2MSL_SUS) {
+ tp->t_timers->tt_flags &= ~TT_2MSL_SUS;
+ if ((tp->t_state == TCPS_FIN_WAIT_2) &&
+ ((tp->t_inpcb->inp_socket == NULL) ||
+ (tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE))) {
+ /* Star the 2MSL timer */
+ tcp_timer_activate(tp, TT_2MSL,
+ (tcp_fast_finwait2_recycle) ?
+ tcp_finwait2_timeout : TP_MAXIDLE(tp));
+ }
+ }
+ break;
+ default:
+ panic("tp:%p bad timer_type 0x%x", tp, timer_type);
+ }
+}
+
+void
tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
{
struct callout *t_callout;
Index: sys/netinet/tcp_var.h
===================================================================
--- sys/netinet/tcp_var.h
+++ sys/netinet/tcp_var.h
@@ -93,8 +93,11 @@
void *t_fb_ptr; /* Pointer to t_fb specific data */
uint32_t t_maxseg:24, /* maximum segment size */
t_logstate:8; /* State of "black box" logging */
- uint32_t t_state:4, /* state of this connection */
- bits_spare : 24;
+ uint32_t t_port:16, /* Tunneling (over udp) port */
+ t_state:4, /* state of this connection */
+ t_idle_reduce : 1,
+ t_delayed_ack: 7, /* Delayed ack variable */
+ bits_spare : 4;
u_int t_flags;
tcp_seq snd_una; /* sent but unacknowledged */
tcp_seq snd_max; /* highest sequence number sent;
@@ -104,7 +107,7 @@
tcp_seq snd_up; /* send urgent pointer */
uint32_t snd_wnd; /* send window */
uint32_t snd_cwnd; /* congestion-controlled window */
- uint32_t cl1_spare; /* Spare to round out CL 1 */
+ uint32_t t_peakrate_thr; /* pre-calculated peak rate threshold */
/* Cache line 2 */
u_int32_t ts_offset; /* our timestamp offset */
u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
@@ -189,6 +192,7 @@
struct cc_var *ccv; /* congestion control specific vars */
struct osd *osd; /* storage for Khelp module data */
int t_bytes_acked; /* # bytes acked during current RTT */
+ u_int t_maxunacktime;
u_int t_keepinit; /* time to establish connection */
u_int t_keepidle; /* time before keepalive probes begin */
u_int t_keepintvl; /* interval between keepalives */
@@ -361,6 +365,7 @@
#define TF2_PLPMTU_PMTUD 0x00000002 /* Allowed to attempt PLPMTUD. */
#define TF2_PLPMTU_MAXSEGSNT 0x00000004 /* Last seg sent was full seg. */
#define TF2_LOG_AUTO 0x00000008 /* Session is auto-logging. */
+#define TF2_DROP_AF_DATA 0x00000010 /* Drop after all data ack'd */
/*
* Structure to hold TCP options that are only used during segment
@@ -649,7 +654,12 @@
int tso;
tcp_seq curack;
};
+#ifdef TCP_HHOOK
+void hhook_run_tcp_est_out(struct tcpcb *tp,
+ struct tcphdr *th, struct tcpopt *to,
+ uint32_t len, int tso);
#endif
+#endif
/*
* TCB structure exported to user-land via sysctl(3).
@@ -801,7 +811,10 @@
#define V_tcp_sack_maxholes VNET(tcp_sack_maxholes)
#define V_tcp_sc_rst_sock_fail VNET(tcp_sc_rst_sock_fail)
#define V_tcp_sendspace VNET(tcp_sendspace)
+#define V_tcp_udp_tunneling_overhead VNET(tcp_udp_tunneling_overhead)
+#define V_tcp_udp_tunneling_port VNET(tcp_udp_tunneling_port)
+
#ifdef TCP_HHOOK
VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
#define V_tcp_hhh VNET(tcp_hhh)
@@ -893,9 +906,12 @@
tcpip_maketemplate(struct inpcb *);
void tcpip_fillheaders(struct inpcb *, void *, void *);
void tcp_timer_activate(struct tcpcb *, uint32_t, u_int);
+int tcp_timer_suspend(struct tcpcb *, uint32_t);
+void tcp_timers_unsuspend(struct tcpcb *, uint32_t);
int tcp_timer_active(struct tcpcb *, uint32_t);
void tcp_timer_stop(struct tcpcb *, uint32_t);
void tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
+int inp_to_cpuid(struct inpcb *inp);
/*
* All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
*/
@@ -921,7 +937,11 @@
int tcp_newreno(struct tcpcb *, struct tcphdr *);
int tcp_compute_pipe(struct tcpcb *);
void tcp_sndbuf_autoscale(struct tcpcb *, struct socket *, uint32_t);
+struct mbuf *
+ tcp_m_copym(struct mbuf *m, int32_t off0, int32_t *plen,
+ int32_t seglimit, int32_t segsize, struct sockbuf *sb);
+
static inline void
tcp_fields_to_host(struct tcphdr *th)
{
Index: sys/sys/mbuf.h
===================================================================
--- sys/sys/mbuf.h
+++ sys/sys/mbuf.h
@@ -304,7 +304,7 @@
#define M_MCAST 0x00000020 /* send/received as link-level multicast */
#define M_PROMISC 0x00000040 /* packet was not for us */
#define M_VLANTAG 0x00000080 /* ether_vtag is valid */
-#define M_UNUSED_8 0x00000100 /* --available-- */
+#define M_NOMAP 0x00000100 /* mbuf data is unmapped (soon from Drew) */
#define M_NOFREE 0x00000200 /* do not free mbuf, embedded in cluster */
#define M_TSTMP 0x00000400 /* rcv_tstmp field is valid */
#define M_TSTMP_HPREC 0x00000800 /* rcv_tstmp is high-prec, typically
Index: sys/sys/queue.h
===================================================================
--- sys/sys/queue.h
+++ sys/sys/queue.h
@@ -95,6 +95,7 @@
* _NEXT + + + +
* _PREV - + - +
* _LAST - - + +
+ * _LAST_FAST - - - +
* _FOREACH + + + +
* _FOREACH_FROM + + + +
* _FOREACH_SAFE + + + +
@@ -817,6 +818,16 @@
#define TAILQ_LAST(head, headname) \
(*(((struct headname *)((head)->tqh_last))->tqh_last))
+/*
+ * The FAST function is fast in that it causes no data access other
+ * then the access to the head. The standard LAST function above
+ * will cause a data access of both the element you want and
+ * the previous element. FAST is very useful for instances when
+ * you may want to prefetch the last data element.
+ */
+#define TAILQ_LAST_FAST(head, type, field) \
+ (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next))
+
#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
#define TAILQ_PREV(elm, headname, field) \
Index: sys/sys/sockbuf.h
===================================================================
--- sys/sys/sockbuf.h
+++ sys/sys/sockbuf.h
@@ -166,6 +166,10 @@
struct mbuf *
sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff);
struct mbuf *
+ sbsndptr_noadv(struct sockbuf *sb, u_int off, u_int *moff);
+void
+ sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, u_int len);
+struct mbuf *
sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff);
int sbwait(struct sockbuf *sb);
int sblock(struct sockbuf *sb, int flags);
Index: sys/sys/time.h
===================================================================
--- sys/sys/time.h
+++ sys/sys/time.h
@@ -289,6 +289,22 @@
#endif /* __BSD_VISIBLE */
#ifdef _KERNEL
+/*
+ * Simple macros to convert ticks to milliseconds
+ * or microseconds and vice-versa. The answer
+ * will always be at least 1. Note the return
+ * value is a uint32_t however we step up the
+ * operations to 64 bit to avoid any overflow/underflow
+ * problems.
+ */
+#define TICKS_2_MSEC(t) max(1, (uint32_t)(hz == 1000) ? \
+ (t) : (((uint64_t)(t) * (uint64_t)1000)/(uint64_t)hz))
+#define TICKS_2_USEC(t) max(1, (uint32_t)(hz == 1000) ? \
+ ((t) * 1000) : (((uint64_t)(t) * (uint64_t)1000000)/(uint64_t)hz))
+#define MSEC_2_TICKS(m) max(1, (uint32_t)((hz == 1000) ? \
+ (m) : ((uint64_t)(m) * (uint64_t)hz)/(uint64_t)1000))
+#define USEC_2_TICKS(u) max(1, (uint32_t)((hz == 1000) ? \
+ ((u) / 1000) : ((uint64_t)(u) * (uint64_t)hz)/(uint64_t)1000000))
/* Operations on timespecs */
#define timespecclear(tvp) ((tvp)->tv_sec = (tvp)->tv_nsec = 0)

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