2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40 #include "opt_kern_tls.h"
41 #include "opt_tcpdebug.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
46 #include <sys/callout.h>
47 #include <sys/eventhandler.h>
49 #include <sys/hhook.h>
51 #include <sys/kernel.h>
53 #include <sys/khelp.h>
58 #include <sys/qmath.h>
59 #include <sys/stats.h>
60 #include <sys/sysctl.h>
62 #include <sys/malloc.h>
63 #include <sys/refcount.h>
66 #include <sys/domain.h>
71 #include <sys/socket.h>
72 #include <sys/socketvar.h>
73 #include <sys/protosw.h>
74 #include <sys/random.h>
78 #include <net/route.h>
79 #include <net/route/nhop.h>
81 #include <net/if_var.h>
84 #include <netinet/in.h>
85 #include <netinet/in_fib.h>
86 #include <netinet/in_kdtrace.h>
87 #include <netinet/in_pcb.h>
88 #include <netinet/in_systm.h>
89 #include <netinet/in_var.h>
90 #include <netinet/ip.h>
91 #include <netinet/ip_icmp.h>
92 #include <netinet/ip_var.h>
94 #include <netinet/icmp6.h>
95 #include <netinet/ip6.h>
96 #include <netinet6/in6_fib.h>
97 #include <netinet6/in6_pcb.h>
98 #include <netinet6/ip6_var.h>
99 #include <netinet6/scope6_var.h>
100 #include <netinet6/nd6.h>
103 #include <netinet/tcp.h>
104 #include <netinet/tcp_fsm.h>
105 #include <netinet/tcp_seq.h>
106 #include <netinet/tcp_timer.h>
107 #include <netinet/tcp_var.h>
108 #include <netinet/tcp_log_buf.h>
109 #include <netinet/tcp_syncache.h>
110 #include <netinet/tcp_hpts.h>
111 #include <netinet/cc/cc.h>
113 #include <netinet6/tcp6_var.h>
115 #include <netinet/tcpip.h>
116 #include <netinet/tcp_fastopen.h>
118 #include <netinet/tcp_pcap.h>
121 #include <netinet/tcp_debug.h>
124 #include <netinet6/ip6protosw.h>
127 #include <netinet/tcp_offload.h>
130 #include <netipsec/ipsec_support.h>
132 #include <machine/in_cksum.h>
133 #include <crypto/siphash/siphash.h>
135 #include <security/mac/mac_framework.h>
137 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
139 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
142 #ifdef NETFLIX_EXP_DETECTION
143 /* Sack attack detection thresholds and such */
144 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack,
145 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
146 "Sack Attack detection thresholds");
147 int32_t tcp_force_detection = 0;
148 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection,
150 &tcp_force_detection, 0,
151 "Do we force detection even if the INP has it off?");
152 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */
153 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh,
155 &tcp_sack_to_ack_thresh, 700,
156 "Percentage of sacks to acks we must see above (10.1 percent is 101)?");
157 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */
158 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh,
160 &tcp_sack_to_move_thresh, 600,
161 "Percentage of sack moves we must see above (10.1 percent is 101)");
162 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */
163 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh,
165 &tcp_restoral_thresh, 550,
166 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)");
167 int32_t tcp_sad_decay_val = 800;
168 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per,
170 &tcp_sad_decay_val, 800,
171 "The decay percentage (10.1 percent equals 101 )");
172 int32_t tcp_map_minimum = 500;
173 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps,
175 &tcp_map_minimum, 500,
176 "Number of Map enteries before we start detection");
177 int32_t tcp_attack_on_turns_on_logging = 0;
178 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged,
180 &tcp_attack_on_turns_on_logging, 0,
181 "When we have a positive hit on attack, do we turn on logging?");
182 int32_t tcp_sad_pacing_interval = 2000;
183 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int,
185 &tcp_sad_pacing_interval, 2000,
186 "What is the minimum pacing interval for a classified attacker?");
188 int32_t tcp_sad_low_pps = 100;
189 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps,
191 &tcp_sad_low_pps, 100,
192 "What is the input pps that below which we do not decay?");
195 struct rwlock tcp_function_lock;
198 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
203 error = sysctl_handle_int(oidp, &new, 0, req);
204 if (error == 0 && req->newptr) {
205 if (new < TCP_MINMSS)
213 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
214 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
215 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I",
216 "Default TCP Maximum Segment Size");
220 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
224 new = V_tcp_v6mssdflt;
225 error = sysctl_handle_int(oidp, &new, 0, req);
226 if (error == 0 && req->newptr) {
227 if (new < TCP_MINMSS)
230 V_tcp_v6mssdflt = new;
235 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
236 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
237 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I",
238 "Default TCP Maximum Segment Size for IPv6");
242 * Minimum MSS we accept and use. This prevents DoS attacks where
243 * we are forced to a ridiculous low MSS like 20 and send hundreds
244 * of packets instead of one. The effect scales with the available
245 * bandwidth and quickly saturates the CPU and network interface
246 * with packet generation and sending. Set to zero to disable MINMSS
247 * checking. This setting prevents us from sending too small packets.
249 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
250 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW,
251 &VNET_NAME(tcp_minmss), 0,
252 "Minimum TCP Maximum Segment Size");
254 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
255 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW,
256 &VNET_NAME(tcp_do_rfc1323), 0,
257 "Enable rfc1323 (high performance TCP) extensions");
259 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 0;
260 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW,
261 &VNET_NAME(tcp_tolerate_missing_ts), 0,
262 "Tolerate missing TCP timestamps");
264 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1;
265 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW,
266 &VNET_NAME(tcp_ts_offset_per_conn), 0,
267 "Initialize TCP timestamps per connection instead of per host pair");
269 static int tcp_log_debug = 0;
270 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
271 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
273 static int tcp_tcbhashsize;
274 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
275 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
277 static int do_tcpdrain = 1;
278 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
279 "Enable tcp_drain routine for extra help when low on mbufs");
281 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD,
282 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
284 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1;
285 #define V_icmp_may_rst VNET(icmp_may_rst)
286 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW,
287 &VNET_NAME(icmp_may_rst), 0,
288 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
290 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0;
291 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
292 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW,
293 &VNET_NAME(tcp_isn_reseed_interval), 0,
294 "Seconds between reseeding of ISN secret");
296 static int tcp_soreceive_stream;
297 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
298 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
300 VNET_DEFINE(uma_zone_t, sack_hole_zone);
301 #define V_sack_hole_zone VNET(sack_hole_zone)
302 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */
304 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS)
309 new = V_tcp_map_entries_limit;
310 error = sysctl_handle_int(oidp, &new, 0, req);
311 if (error == 0 && req->newptr) {
312 /* only allow "0" and value > minimum */
313 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT)
316 V_tcp_map_entries_limit = new;
320 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit,
321 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
322 &VNET_NAME(tcp_map_entries_limit), 0,
323 &sysctl_net_inet_tcp_map_limit_check, "IU",
324 "Total sendmap entries limit");
326 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */
327 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW,
328 &VNET_NAME(tcp_map_split_limit), 0,
329 "Total sendmap split entries limit");
332 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
335 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH
336 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]);
337 #define V_ts_offset_secret VNET(ts_offset_secret)
339 static int tcp_default_fb_init(struct tcpcb *tp);
340 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged);
341 static int tcp_default_handoff_ok(struct tcpcb *tp);
342 static struct inpcb *tcp_notify(struct inpcb *, int);
343 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
344 static void tcp_mtudisc(struct inpcb *, int);
345 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
346 void *ip4hdr, const void *ip6hdr);
348 static struct tcp_function_block tcp_def_funcblk = {
349 .tfb_tcp_block_name = "freebsd",
350 .tfb_tcp_output = tcp_output,
351 .tfb_tcp_do_segment = tcp_do_segment,
352 .tfb_tcp_ctloutput = tcp_default_ctloutput,
353 .tfb_tcp_handoff_ok = tcp_default_handoff_ok,
354 .tfb_tcp_fb_init = tcp_default_fb_init,
355 .tfb_tcp_fb_fini = tcp_default_fb_fini,
358 static int tcp_fb_cnt = 0;
359 struct tcp_funchead t_functions;
360 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk;
362 static struct tcp_function_block *
363 find_tcp_functions_locked(struct tcp_function_set *fs)
365 struct tcp_function *f;
366 struct tcp_function_block *blk=NULL;
368 TAILQ_FOREACH(f, &t_functions, tf_next) {
369 if (strcmp(f->tf_name, fs->function_set_name) == 0) {
377 static struct tcp_function_block *
378 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s)
380 struct tcp_function_block *rblk=NULL;
381 struct tcp_function *f;
383 TAILQ_FOREACH(f, &t_functions, tf_next) {
384 if (f->tf_fb == blk) {
395 struct tcp_function_block *
396 find_and_ref_tcp_functions(struct tcp_function_set *fs)
398 struct tcp_function_block *blk;
400 rw_rlock(&tcp_function_lock);
401 blk = find_tcp_functions_locked(fs);
403 refcount_acquire(&blk->tfb_refcnt);
404 rw_runlock(&tcp_function_lock);
408 struct tcp_function_block *
409 find_and_ref_tcp_fb(struct tcp_function_block *blk)
411 struct tcp_function_block *rblk;
413 rw_rlock(&tcp_function_lock);
414 rblk = find_tcp_fb_locked(blk, NULL);
416 refcount_acquire(&rblk->tfb_refcnt);
417 rw_runlock(&tcp_function_lock);
421 static struct tcp_function_block *
422 find_and_ref_tcp_default_fb(void)
424 struct tcp_function_block *rblk;
426 rw_rlock(&tcp_function_lock);
427 rblk = tcp_func_set_ptr;
428 refcount_acquire(&rblk->tfb_refcnt);
429 rw_runlock(&tcp_function_lock);
434 tcp_switch_back_to_default(struct tcpcb *tp)
436 struct tcp_function_block *tfb;
438 KASSERT(tp->t_fb != &tcp_def_funcblk,
439 ("%s: called by the built-in default stack", __func__));
442 * Release the old stack. This function will either find a new one
445 if (tp->t_fb->tfb_tcp_fb_fini != NULL)
446 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0);
447 refcount_release(&tp->t_fb->tfb_refcnt);
450 * Now, we'll find a new function block to use.
451 * Start by trying the current user-selected
452 * default, unless this stack is the user-selected
455 tfb = find_and_ref_tcp_default_fb();
456 if (tfb == tp->t_fb) {
457 refcount_release(&tfb->tfb_refcnt);
460 /* Does the stack accept this connection? */
461 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL &&
462 (*tfb->tfb_tcp_handoff_ok)(tp)) {
463 refcount_release(&tfb->tfb_refcnt);
466 /* Try to use that stack. */
468 /* Initialize the new stack. If it succeeds, we are done. */
470 if (tp->t_fb->tfb_tcp_fb_init == NULL ||
471 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0)
475 * Initialization failed. Release the reference count on
478 refcount_release(&tfb->tfb_refcnt);
482 * If that wasn't feasible, use the built-in default
483 * stack which is not allowed to reject anyone.
485 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk);
487 /* there always should be a default */
488 panic("Can't refer to tcp_def_funcblk");
490 if (tfb->tfb_tcp_handoff_ok != NULL) {
491 if ((*tfb->tfb_tcp_handoff_ok) (tp)) {
492 /* The default stack cannot say no */
493 panic("Default stack rejects a new session?");
497 if (tp->t_fb->tfb_tcp_fb_init != NULL &&
498 (*tp->t_fb->tfb_tcp_fb_init)(tp)) {
499 /* The default stack cannot fail */
500 panic("Default stack initialization failed");
505 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)
508 struct tcp_function_set fs;
509 struct tcp_function_block *blk;
511 memset(&fs, 0, sizeof(fs));
512 rw_rlock(&tcp_function_lock);
513 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL);
516 strcpy(fs.function_set_name, blk->tfb_tcp_block_name);
517 fs.pcbcnt = blk->tfb_refcnt;
519 rw_runlock(&tcp_function_lock);
520 error = sysctl_handle_string(oidp, fs.function_set_name,
521 sizeof(fs.function_set_name), req);
523 /* Check for error or no change */
524 if (error != 0 || req->newptr == NULL)
527 rw_wlock(&tcp_function_lock);
528 blk = find_tcp_functions_locked(&fs);
530 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) {
534 tcp_func_set_ptr = blk;
536 rw_wunlock(&tcp_function_lock);
540 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default,
541 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
542 NULL, 0, sysctl_net_inet_default_tcp_functions, "A",
543 "Set/get the default TCP functions");
546 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS)
548 int error, cnt, linesz;
549 struct tcp_function *f;
555 rw_rlock(&tcp_function_lock);
556 TAILQ_FOREACH(f, &t_functions, tf_next) {
559 rw_runlock(&tcp_function_lock);
561 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1;
562 buffer = malloc(bufsz, M_TEMP, M_WAITOK);
567 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D',
568 "Alias", "PCB count");
573 rw_rlock(&tcp_function_lock);
574 TAILQ_FOREACH(f, &t_functions, tf_next) {
575 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name);
576 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n",
577 f->tf_fb->tfb_tcp_block_name,
578 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ',
579 alias ? f->tf_name : "-",
580 f->tf_fb->tfb_refcnt);
581 if (linesz >= bufsz) {
589 rw_runlock(&tcp_function_lock);
591 error = sysctl_handle_string(oidp, buffer, outsz + 1, req);
592 free(buffer, M_TEMP);
596 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available,
597 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
598 NULL, 0, sysctl_net_inet_list_available, "A",
599 "list available TCP Function sets");
602 * Exports one (struct tcp_function_info) for each alias/name.
605 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS)
608 struct tcp_function *f;
609 struct tcp_function_info tfi;
612 * We don't allow writes.
614 if (req->newptr != NULL)
618 * Wire the old buffer so we can directly copy the functions to
619 * user space without dropping the lock.
621 if (req->oldptr != NULL) {
622 error = sysctl_wire_old_buffer(req, 0);
628 * Walk the list and copy out matching entries. If INVARIANTS
629 * is compiled in, also walk the list to verify the length of
630 * the list matches what we have recorded.
632 rw_rlock(&tcp_function_lock);
636 if (req->oldptr == NULL) {
641 TAILQ_FOREACH(f, &t_functions, tf_next) {
645 if (req->oldptr != NULL) {
646 bzero(&tfi, sizeof(tfi));
647 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt;
648 tfi.tfi_id = f->tf_fb->tfb_id;
649 (void)strlcpy(tfi.tfi_alias, f->tf_name,
650 sizeof(tfi.tfi_alias));
651 (void)strlcpy(tfi.tfi_name,
652 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name));
653 error = SYSCTL_OUT(req, &tfi, sizeof(tfi));
655 * Don't stop on error, as that is the
656 * mechanism we use to accumulate length
657 * information if the buffer was too short.
661 KASSERT(cnt == tcp_fb_cnt,
662 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt));
666 rw_runlock(&tcp_function_lock);
667 if (req->oldptr == NULL)
668 error = SYSCTL_OUT(req, NULL,
669 (cnt + 1) * sizeof(struct tcp_function_info));
674 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info,
675 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE,
676 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info",
677 "List TCP function block name-to-ID mappings");
680 * tfb_tcp_handoff_ok() function for the default stack.
681 * Note that we'll basically try to take all comers.
684 tcp_default_handoff_ok(struct tcpcb *tp)
691 * tfb_tcp_fb_init() function for the default stack.
693 * This handles making sure we have appropriate timers set if you are
694 * transitioning a socket that has some amount of setup done.
696 * The init() fuction from the default can *never* return non-zero i.e.
697 * it is required to always succeed since it is the stack of last resort!
700 tcp_default_fb_init(struct tcpcb *tp)
705 INP_WLOCK_ASSERT(tp->t_inpcb);
707 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT,
708 ("%s: connection %p in unexpected state %d", __func__, tp,
712 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't
713 * know what to do for unexpected states (which includes TIME_WAIT).
715 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT)
719 * Make sure some kind of transmission timer is set if there is
722 so = tp->t_inpcb->inp_socket;
723 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) ||
724 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) ||
725 tcp_timer_active(tp, TT_PERSIST))) {
727 * If the session has established and it looks like it should
728 * be in the persist state, set the persist timer. Otherwise,
729 * set the retransmit timer.
731 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 &&
732 (int32_t)(tp->snd_nxt - tp->snd_una) <
733 (int32_t)sbavail(&so->so_snd))
736 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur);
739 /* All non-embryonic sessions get a keepalive timer. */
740 if (!tcp_timer_active(tp, TT_KEEP))
741 tcp_timer_activate(tp, TT_KEEP,
742 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) :
746 * Make sure critical variables are initialized
747 * if transitioning while in Recovery.
749 if IN_FASTRECOVERY(tp->t_flags) {
750 if (tp->sackhint.recover_fs == 0)
751 tp->sackhint.recover_fs = max(1,
752 tp->snd_nxt - tp->snd_una);
759 * tfb_tcp_fb_fini() function for the default stack.
761 * This changes state as necessary (or prudent) to prepare for another stack
762 * to assume responsibility for the connection.
765 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged)
768 INP_WLOCK_ASSERT(tp->t_inpcb);
773 * Target size of TCP PCB hash tables. Must be a power of two.
775 * Note that this can be overridden by the kernel environment
776 * variable net.inet.tcp.tcbhashsize
779 #define TCBHASHSIZE 0
784 * Callouts should be moved into struct tcp directly. They are currently
785 * separate because the tcpcb structure is exported to userland for sysctl
786 * parsing purposes, which do not know about callouts.
797 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone);
798 #define V_tcpcb_zone VNET(tcpcb_zone)
800 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
801 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory");
803 static struct mtx isn_mtx;
805 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
806 #define ISN_LOCK() mtx_lock(&isn_mtx)
807 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
810 * TCP initialization.
813 tcp_zone_change(void *tag)
816 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
817 uma_zone_set_max(V_tcpcb_zone, maxsockets);
818 tcp_tw_zone_change();
822 tcp_inpcb_init(void *mem, int size, int flags)
824 struct inpcb *inp = mem;
826 INP_LOCK_INIT(inp, "inp", "tcpinp");
831 * Take a value and get the next power of 2 that doesn't overflow.
832 * Used to size the tcp_inpcb hash buckets.
835 maketcp_hashsize(int size)
841 * get the next power of 2 higher than maxsockets.
843 hashsize = 1 << fls(size);
844 /* catch overflow, and just go one power of 2 smaller */
845 if (hashsize < size) {
846 hashsize = 1 << (fls(size) - 1);
851 static volatile int next_tcp_stack_id = 1;
854 * Register a TCP function block with the name provided in the names
855 * array. (Note that this function does NOT automatically register
856 * blk->tfb_tcp_block_name as a stack name. Therefore, you should
857 * explicitly include blk->tfb_tcp_block_name in the list of names if
858 * you wish to register the stack with that name.)
860 * Either all name registrations will succeed or all will fail. If
861 * a name registration fails, the function will update the num_names
862 * argument to point to the array index of the name that encountered
865 * Returns 0 on success, or an error code on failure.
868 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait,
869 const char *names[], int *num_names)
871 struct tcp_function *n;
872 struct tcp_function_set fs;
875 KASSERT(names != NULL && *num_names > 0,
876 ("%s: Called with 0-length name list", __func__));
877 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__));
878 KASSERT(rw_initialized(&tcp_function_lock),
879 ("%s: called too early", __func__));
881 if ((blk->tfb_tcp_output == NULL) ||
882 (blk->tfb_tcp_do_segment == NULL) ||
883 (blk->tfb_tcp_ctloutput == NULL) ||
884 (strlen(blk->tfb_tcp_block_name) == 0)) {
886 * These functions are required and you
892 if (blk->tfb_tcp_timer_stop_all ||
893 blk->tfb_tcp_timer_activate ||
894 blk->tfb_tcp_timer_active ||
895 blk->tfb_tcp_timer_stop) {
897 * If you define one timer function you
898 * must have them all.
900 if ((blk->tfb_tcp_timer_stop_all == NULL) ||
901 (blk->tfb_tcp_timer_activate == NULL) ||
902 (blk->tfb_tcp_timer_active == NULL) ||
903 (blk->tfb_tcp_timer_stop == NULL)) {
909 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
914 refcount_init(&blk->tfb_refcnt, 0);
915 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1);
916 for (i = 0; i < *num_names; i++) {
917 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait);
924 (void)strlcpy(fs.function_set_name, names[i],
925 sizeof(fs.function_set_name));
926 rw_wlock(&tcp_function_lock);
927 if (find_tcp_functions_locked(&fs) != NULL) {
928 /* Duplicate name space not allowed */
929 rw_wunlock(&tcp_function_lock);
930 free(n, M_TCPFUNCTIONS);
934 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name));
935 TAILQ_INSERT_TAIL(&t_functions, n, tf_next);
937 rw_wunlock(&tcp_function_lock);
943 * Deregister the names we just added. Because registration failed
944 * for names[i], we don't need to deregister that name.
947 rw_wlock(&tcp_function_lock);
949 TAILQ_FOREACH(n, &t_functions, tf_next) {
950 if (!strncmp(n->tf_name, names[i],
951 TCP_FUNCTION_NAME_LEN_MAX)) {
952 TAILQ_REMOVE(&t_functions, n, tf_next);
955 free(n, M_TCPFUNCTIONS);
960 rw_wunlock(&tcp_function_lock);
965 * Register a TCP function block using the name provided in the name
968 * Returns 0 on success, or an error code on failure.
971 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name,
974 const char *name_list[1];
981 name_list[0] = blk->tfb_tcp_block_name;
982 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names);
987 * Register a TCP function block using the name defined in
988 * blk->tfb_tcp_block_name.
990 * Returns 0 on success, or an error code on failure.
993 register_tcp_functions(struct tcp_function_block *blk, int wait)
996 return (register_tcp_functions_as_name(blk, NULL, wait));
1000 * Deregister all names associated with a function block. This
1001 * functionally removes the function block from use within the system.
1003 * When called with a true quiesce argument, mark the function block
1004 * as being removed so no more stacks will use it and determine
1005 * whether the removal would succeed.
1007 * When called with a false quiesce argument, actually attempt the
1010 * When called with a force argument, attempt to switch all TCBs to
1011 * use the default stack instead of returning EBUSY.
1013 * Returns 0 on success (or if the removal would succeed, or an error
1017 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce,
1020 struct tcp_function *f;
1022 if (blk == &tcp_def_funcblk) {
1023 /* You can't un-register the default */
1026 rw_wlock(&tcp_function_lock);
1027 if (blk == tcp_func_set_ptr) {
1028 /* You can't free the current default */
1029 rw_wunlock(&tcp_function_lock);
1032 /* Mark the block so no more stacks can use it. */
1033 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED;
1035 * If TCBs are still attached to the stack, attempt to switch them
1036 * to the default stack.
1038 if (force && blk->tfb_refcnt) {
1041 VNET_ITERATOR_DECL(vnet_iter);
1043 rw_wunlock(&tcp_function_lock);
1046 VNET_FOREACH(vnet_iter) {
1047 CURVNET_SET(vnet_iter);
1048 INP_INFO_WLOCK(&V_tcbinfo);
1049 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) {
1051 if (inp->inp_flags & INP_TIMEWAIT) {
1055 tp = intotcpcb(inp);
1056 if (tp == NULL || tp->t_fb != blk) {
1060 tcp_switch_back_to_default(tp);
1063 INP_INFO_WUNLOCK(&V_tcbinfo);
1066 VNET_LIST_RUNLOCK();
1068 rw_wlock(&tcp_function_lock);
1070 if (blk->tfb_refcnt) {
1071 /* TCBs still attached. */
1072 rw_wunlock(&tcp_function_lock);
1077 rw_wunlock(&tcp_function_lock);
1080 /* Remove any function names that map to this function block. */
1081 while (find_tcp_fb_locked(blk, &f) != NULL) {
1082 TAILQ_REMOVE(&t_functions, f, tf_next);
1085 free(f, M_TCPFUNCTIONS);
1087 rw_wunlock(&tcp_function_lock);
1094 const char *tcbhash_tuneable;
1097 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
1100 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
1101 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
1102 printf("%s: WARNING: unable to register helper hook\n", __func__);
1103 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
1104 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
1105 printf("%s: WARNING: unable to register helper hook\n", __func__);
1108 if (tcp_stats_init())
1109 printf("%s: WARNING: unable to initialise TCP stats\n",
1112 hashsize = TCBHASHSIZE;
1113 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
1114 if (hashsize == 0) {
1116 * Auto tune the hash size based on maxsockets.
1117 * A perfect hash would have a 1:1 mapping
1118 * (hashsize = maxsockets) however it's been
1119 * suggested that O(2) average is better.
1121 hashsize = maketcp_hashsize(maxsockets / 4);
1123 * Our historical default is 512,
1124 * do not autotune lower than this.
1128 if (bootverbose && IS_DEFAULT_VNET(curvnet))
1129 printf("%s: %s auto tuned to %d\n", __func__,
1130 tcbhash_tuneable, hashsize);
1133 * We require a hashsize to be a power of two.
1134 * Previously if it was not a power of two we would just reset it
1135 * back to 512, which could be a nasty surprise if you did not notice
1136 * the error message.
1137 * Instead what we do is clip it to the closest power of two lower
1138 * than the specified hash value.
1140 if (!powerof2(hashsize)) {
1141 int oldhashsize = hashsize;
1143 hashsize = maketcp_hashsize(hashsize);
1144 /* prevent absurdly low value */
1147 printf("%s: WARNING: TCB hash size not a power of 2, "
1148 "clipped from %d to %d.\n", __func__, oldhashsize,
1151 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
1152 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE);
1155 * These have to be type stable for the benefit of the timers.
1157 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
1158 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1159 uma_zone_set_max(V_tcpcb_zone, maxsockets);
1160 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
1166 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
1167 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
1168 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1170 tcp_fastopen_init();
1172 /* Skip initialization of globals for non-default instances. */
1173 if (!IS_DEFAULT_VNET(curvnet))
1176 tcp_reass_global_init();
1178 /* XXX virtualize those bellow? */
1179 tcp_delacktime = TCPTV_DELACK;
1180 tcp_keepinit = TCPTV_KEEP_INIT;
1181 tcp_keepidle = TCPTV_KEEP_IDLE;
1182 tcp_keepintvl = TCPTV_KEEPINTVL;
1183 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
1184 tcp_msl = TCPTV_MSL;
1185 tcp_rexmit_initial = TCPTV_RTOBASE;
1186 if (tcp_rexmit_initial < 1)
1187 tcp_rexmit_initial = 1;
1188 tcp_rexmit_min = TCPTV_MIN;
1189 if (tcp_rexmit_min < 1)
1191 tcp_persmin = TCPTV_PERSMIN;
1192 tcp_persmax = TCPTV_PERSMAX;
1193 tcp_rexmit_slop = TCPTV_CPU_VAR;
1194 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
1195 tcp_tcbhashsize = hashsize;
1197 /* Setup the tcp function block list */
1198 TAILQ_INIT(&t_functions);
1199 rw_init(&tcp_function_lock, "tcp_func_lock");
1200 register_tcp_functions(&tcp_def_funcblk, M_WAITOK);
1202 /* Initialize the TCP logging data. */
1205 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0);
1207 if (tcp_soreceive_stream) {
1209 tcp_usrreqs.pru_soreceive = soreceive_stream;
1212 tcp6_usrreqs.pru_soreceive = soreceive_stream;
1217 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
1219 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
1221 if (max_protohdr < TCP_MINPROTOHDR)
1222 max_protohdr = TCP_MINPROTOHDR;
1223 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
1225 #undef TCP_MINPROTOHDR
1228 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
1229 SHUTDOWN_PRI_DEFAULT);
1230 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
1231 EVENTHANDLER_PRI_ANY);
1233 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK);
1234 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK);
1235 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK);
1236 tcp_inp_lro_single_push = counter_u64_alloc(M_WAITOK);
1237 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK);
1238 tcp_inp_lro_sack_wake = counter_u64_alloc(M_WAITOK);
1239 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK);
1240 tcp_would_have_but = counter_u64_alloc(M_WAITOK);
1241 tcp_comp_total = counter_u64_alloc(M_WAITOK);
1242 tcp_uncomp_total = counter_u64_alloc(M_WAITOK);
1243 tcp_csum_hardware = counter_u64_alloc(M_WAITOK);
1244 tcp_csum_hardware_w_ph = counter_u64_alloc(M_WAITOK);
1245 tcp_csum_software = counter_u64_alloc(M_WAITOK);
1253 tcp_destroy(void *unused __unused)
1261 * All our processes are gone, all our sockets should be cleaned
1262 * up, which means, we should be past the tcp_discardcb() calls.
1263 * Sleep to let all tcpcb timers really disappear and cleanup.
1266 INP_LIST_RLOCK(&V_tcbinfo);
1267 n = V_tcbinfo.ipi_count;
1268 INP_LIST_RUNLOCK(&V_tcbinfo);
1271 pause("tcpdes", hz / 10);
1276 in_pcbinfo_destroy(&V_tcbinfo);
1277 /* tcp_discardcb() clears the sack_holes up. */
1278 uma_zdestroy(V_sack_hole_zone);
1279 uma_zdestroy(V_tcpcb_zone);
1282 * Cannot free the zone until all tcpcbs are released as we attach
1283 * the allocations to them.
1285 tcp_fastopen_destroy();
1288 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
1290 printf("%s: WARNING: unable to deregister helper hook "
1291 "type=%d, id=%d: error %d returned\n", __func__,
1292 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
1294 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
1296 printf("%s: WARNING: unable to deregister helper hook "
1297 "type=%d, id=%d: error %d returned\n", __func__,
1298 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
1302 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL);
1312 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
1313 * tcp_template used to store this data in mbufs, but we now recopy it out
1314 * of the tcpcb each time to conserve mbufs.
1317 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
1319 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
1321 INP_WLOCK_ASSERT(inp);
1324 if ((inp->inp_vflag & INP_IPV6) != 0) {
1325 struct ip6_hdr *ip6;
1327 ip6 = (struct ip6_hdr *)ip_ptr;
1328 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
1329 (inp->inp_flow & IPV6_FLOWINFO_MASK);
1330 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
1331 (IPV6_VERSION & IPV6_VERSION_MASK);
1332 ip6->ip6_nxt = IPPROTO_TCP;
1333 ip6->ip6_plen = htons(sizeof(struct tcphdr));
1334 ip6->ip6_src = inp->in6p_laddr;
1335 ip6->ip6_dst = inp->in6p_faddr;
1338 #if defined(INET6) && defined(INET)
1345 ip = (struct ip *)ip_ptr;
1346 ip->ip_v = IPVERSION;
1348 ip->ip_tos = inp->inp_ip_tos;
1352 ip->ip_ttl = inp->inp_ip_ttl;
1354 ip->ip_p = IPPROTO_TCP;
1355 ip->ip_src = inp->inp_laddr;
1356 ip->ip_dst = inp->inp_faddr;
1359 th->th_sport = inp->inp_lport;
1360 th->th_dport = inp->inp_fport;
1368 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
1372 * Create template to be used to send tcp packets on a connection.
1373 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
1374 * use for this function is in keepalives, which use tcp_respond.
1377 tcpip_maketemplate(struct inpcb *inp)
1381 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
1384 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
1389 * Send a single message to the TCP at address specified by
1390 * the given TCP/IP header. If m == NULL, then we make a copy
1391 * of the tcpiphdr at th and send directly to the addressed host.
1392 * This is used to force keep alive messages out using the TCP
1393 * template for a connection. If flags are given then we send
1394 * a message back to the TCP which originated the segment th,
1395 * and discard the mbuf containing it and any other attached mbufs.
1397 * In any case the ack and sequence number of the transmitted
1398 * segment are as specified by the parameters.
1400 * NOTE: If m != NULL, then th must point to *inside* the mbuf.
1403 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
1404 tcp_seq ack, tcp_seq seq, int flags)
1413 struct ip6_hdr *ip6;
1416 int optlen, tlen, win;
1419 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
1423 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
1430 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
1431 INP_WLOCK_ASSERT(inp);
1438 if (!(flags & TH_RST)) {
1439 win = sbspace(&inp->inp_socket->so_rcv);
1440 if (win > TCP_MAXWIN << tp->rcv_scale)
1441 win = TCP_MAXWIN << tp->rcv_scale;
1443 if ((tp->t_flags & TF_NOOPT) == 0)
1447 m = m_gethdr(M_NOWAIT, MT_DATA);
1450 m->m_data += max_linkhdr;
1453 bcopy((caddr_t)ip6, mtod(m, caddr_t),
1454 sizeof(struct ip6_hdr));
1455 ip6 = mtod(m, struct ip6_hdr *);
1456 nth = (struct tcphdr *)(ip6 + 1);
1460 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
1461 ip = mtod(m, struct ip *);
1462 nth = (struct tcphdr *)(ip + 1);
1464 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1466 } else if (!M_WRITABLE(m)) {
1469 /* Can't reuse 'm', allocate a new mbuf. */
1470 n = m_gethdr(M_NOWAIT, MT_DATA);
1476 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
1482 n->m_data += max_linkhdr;
1483 /* m_len is set later */
1484 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
1487 bcopy((caddr_t)ip6, mtod(n, caddr_t),
1488 sizeof(struct ip6_hdr));
1489 ip6 = mtod(n, struct ip6_hdr *);
1490 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1491 nth = (struct tcphdr *)(ip6 + 1);
1495 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip));
1496 ip = mtod(n, struct ip *);
1497 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1498 nth = (struct tcphdr *)(ip + 1);
1500 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1501 xchg(nth->th_dport, nth->th_sport, uint16_t);
1508 * XXX MRT We inherit the FIB, which is lucky.
1512 m->m_data = (caddr_t)ipgen;
1513 /* m_len is set later */
1516 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1517 nth = (struct tcphdr *)(ip6 + 1);
1521 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1522 nth = (struct tcphdr *)(ip + 1);
1526 * this is usually a case when an extension header
1527 * exists between the IPv6 header and the
1530 nth->th_sport = th->th_sport;
1531 nth->th_dport = th->th_dport;
1533 xchg(nth->th_dport, nth->th_sport, uint16_t);
1539 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
1541 #if defined(INET) && defined(INET6)
1545 tlen = sizeof (struct tcpiphdr);
1549 KASSERT(M_TRAILINGSPACE(m) >= tlen,
1550 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)",
1551 m, tlen, (long)M_TRAILINGSPACE(m)));
1556 /* Make sure we have room. */
1557 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) {
1558 m->m_next = m_get(M_NOWAIT, MT_DATA);
1560 optp = mtod(m->m_next, u_char *);
1565 optp = (u_char *) (nth + 1);
1571 if (tp->t_flags & TF_RCVD_TSTMP) {
1572 to.to_tsval = tcp_ts_getticks() + tp->ts_offset;
1573 to.to_tsecr = tp->ts_recent;
1574 to.to_flags |= TOF_TS;
1576 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1577 /* TCP-MD5 (RFC2385). */
1578 if (tp->t_flags & TF_SIGNATURE)
1579 to.to_flags |= TOF_SIGNATURE;
1581 /* Add the options. */
1582 tlen += optlen = tcp_addoptions(&to, optp);
1584 /* Update m_len in the correct mbuf. */
1585 optm->m_len += optlen;
1591 ip6->ip6_vfc = IPV6_VERSION;
1592 ip6->ip6_nxt = IPPROTO_TCP;
1593 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
1596 #if defined(INET) && defined(INET6)
1601 ip->ip_len = htons(tlen);
1602 ip->ip_ttl = V_ip_defttl;
1603 if (V_path_mtu_discovery)
1604 ip->ip_off |= htons(IP_DF);
1607 m->m_pkthdr.len = tlen;
1608 m->m_pkthdr.rcvif = NULL;
1612 * Packet is associated with a socket, so allow the
1613 * label of the response to reflect the socket label.
1615 INP_WLOCK_ASSERT(inp);
1616 mac_inpcb_create_mbuf(inp, m);
1619 * Packet is not associated with a socket, so possibly
1620 * update the label in place.
1622 mac_netinet_tcp_reply(m);
1625 nth->th_seq = htonl(seq);
1626 nth->th_ack = htonl(ack);
1628 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
1629 nth->th_flags = flags;
1631 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
1633 nth->th_win = htons((u_short)win);
1636 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1637 if (to.to_flags & TOF_SIGNATURE) {
1638 if (!TCPMD5_ENABLED() ||
1639 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) {
1646 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
1649 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
1650 nth->th_sum = in6_cksum_pseudo(ip6,
1651 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
1652 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
1656 #if defined(INET6) && defined(INET)
1661 m->m_pkthdr.csum_flags = CSUM_TCP;
1662 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
1663 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
1667 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
1668 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
1670 TCP_PROBE3(debug__output, tp, th, m);
1672 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth);
1676 TCP_PROBE5(send, NULL, tp, ip6, tp, nth);
1677 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp);
1680 #if defined(INET) && defined(INET6)
1685 TCP_PROBE5(send, NULL, tp, ip, tp, nth);
1686 (void)ip_output(m, NULL, NULL, 0, NULL, inp);
1692 * Create a new TCP control block, making an
1693 * empty reassembly queue and hooking it to the argument
1694 * protocol control block. The `inp' parameter must have
1695 * come from the zone allocator set up in tcp_init().
1698 tcp_newtcpcb(struct inpcb *inp)
1700 struct tcpcb_mem *tm;
1703 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
1706 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
1711 /* Initialise cc_var struct for this tcpcb. */
1713 tp->ccv->type = IPPROTO_TCP;
1714 tp->ccv->ccvc.tcp = tp;
1715 rw_rlock(&tcp_function_lock);
1716 tp->t_fb = tcp_func_set_ptr;
1717 refcount_acquire(&tp->t_fb->tfb_refcnt);
1718 rw_runlock(&tcp_function_lock);
1720 * Use the current system default CC algorithm.
1723 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
1724 CC_ALGO(tp) = CC_DEFAULT();
1727 * The tcpcb will hold a reference on its inpcb until tcp_discardcb()
1730 in_pcbref(inp); /* Reference for tcpcb */
1733 if (CC_ALGO(tp)->cb_init != NULL)
1734 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
1735 if (tp->t_fb->tfb_tcp_fb_fini)
1736 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1737 in_pcbrele_wlocked(inp);
1738 refcount_release(&tp->t_fb->tfb_refcnt);
1739 uma_zfree(V_tcpcb_zone, tm);
1745 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
1746 if (tp->t_fb->tfb_tcp_fb_fini)
1747 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1748 in_pcbrele_wlocked(inp);
1749 refcount_release(&tp->t_fb->tfb_refcnt);
1750 uma_zfree(V_tcpcb_zone, tm);
1756 tp->t_vnet = inp->inp_vnet;
1758 tp->t_timers = &tm->tt;
1759 TAILQ_INIT(&tp->t_segq);
1762 isipv6 ? V_tcp_v6mssdflt :
1766 /* Set up our timeouts. */
1767 callout_init(&tp->t_timers->tt_rexmt, 1);
1768 callout_init(&tp->t_timers->tt_persist, 1);
1769 callout_init(&tp->t_timers->tt_keep, 1);
1770 callout_init(&tp->t_timers->tt_2msl, 1);
1771 callout_init(&tp->t_timers->tt_delack, 1);
1773 if (V_tcp_do_rfc1323)
1774 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
1776 tp->t_flags |= TF_SACK_PERMIT;
1777 TAILQ_INIT(&tp->snd_holes);
1780 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
1781 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
1782 * reasonable initial retransmit time.
1784 tp->t_srtt = TCPTV_SRTTBASE;
1785 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
1786 tp->t_rttmin = tcp_rexmit_min;
1787 tp->t_rxtcur = tcp_rexmit_initial;
1788 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1789 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1790 tp->t_rcvtime = ticks;
1792 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1793 * because the socket may be bound to an IPv6 wildcard address,
1794 * which may match an IPv4-mapped IPv6 address.
1796 inp->inp_ip_ttl = V_ip_defttl;
1800 * Init the TCP PCAP queues.
1802 tcp_pcap_tcpcb_init(tp);
1805 /* Initialize the per-TCPCB log data. */
1806 tcp_log_tcpcbinit(tp);
1808 tp->t_pacing_rate = -1;
1809 if (tp->t_fb->tfb_tcp_fb_init) {
1810 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) {
1811 refcount_release(&tp->t_fb->tfb_refcnt);
1812 in_pcbrele_wlocked(inp);
1813 uma_zfree(V_tcpcb_zone, tm);
1818 if (V_tcp_perconn_stats_enable == 1)
1819 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0);
1821 return (tp); /* XXX */
1825 * Switch the congestion control algorithm back to NewReno for any active
1826 * control blocks using an algorithm which is about to go away.
1827 * This ensures the CC framework can allow the unload to proceed without leaving
1828 * any dangling pointers which would trigger a panic.
1829 * Returning non-zero would inform the CC framework that something went wrong
1830 * and it would be unsafe to allow the unload to proceed. However, there is no
1831 * way for this to occur with this implementation so we always return zero.
1834 tcp_ccalgounload(struct cc_algo *unload_algo)
1836 struct cc_algo *tmpalgo;
1839 VNET_ITERATOR_DECL(vnet_iter);
1842 * Check all active control blocks across all network stacks and change
1843 * any that are using "unload_algo" back to NewReno. If "unload_algo"
1844 * requires cleanup code to be run, call it.
1847 VNET_FOREACH(vnet_iter) {
1848 CURVNET_SET(vnet_iter);
1849 INP_INFO_WLOCK(&V_tcbinfo);
1851 * New connections already part way through being initialised
1852 * with the CC algo we're removing will not race with this code
1853 * because the INP_INFO_WLOCK is held during initialisation. We
1854 * therefore don't enter the loop below until the connection
1855 * list has stabilised.
1857 CK_LIST_FOREACH(inp, &V_tcb, inp_list) {
1859 /* Important to skip tcptw structs. */
1860 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1861 (tp = intotcpcb(inp)) != NULL) {
1863 * By holding INP_WLOCK here, we are assured
1864 * that the connection is not currently
1865 * executing inside the CC module's functions
1866 * i.e. it is safe to make the switch back to
1869 if (CC_ALGO(tp) == unload_algo) {
1870 tmpalgo = CC_ALGO(tp);
1871 if (tmpalgo->cb_destroy != NULL)
1872 tmpalgo->cb_destroy(tp->ccv);
1875 * NewReno may allocate memory on
1876 * demand for certain stateful
1877 * configuration as needed, but is
1878 * coded to never fail on memory
1879 * allocation failure so it is a safe
1882 CC_ALGO(tp) = &newreno_cc_algo;
1887 INP_INFO_WUNLOCK(&V_tcbinfo);
1890 VNET_LIST_RUNLOCK();
1896 * Drop a TCP connection, reporting
1897 * the specified error. If connection is synchronized,
1898 * then send a RST to peer.
1901 tcp_drop(struct tcpcb *tp, int errno)
1903 struct socket *so = tp->t_inpcb->inp_socket;
1906 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1907 INP_WLOCK_ASSERT(tp->t_inpcb);
1909 if (TCPS_HAVERCVDSYN(tp->t_state)) {
1910 tcp_state_change(tp, TCPS_CLOSED);
1911 (void) tp->t_fb->tfb_tcp_output(tp);
1912 TCPSTAT_INC(tcps_drops);
1914 TCPSTAT_INC(tcps_conndrops);
1915 if (errno == ETIMEDOUT && tp->t_softerror)
1916 errno = tp->t_softerror;
1917 so->so_error = errno;
1918 return (tcp_close(tp));
1922 tcp_discardcb(struct tcpcb *tp)
1924 struct inpcb *inp = tp->t_inpcb;
1925 struct socket *so = inp->inp_socket;
1927 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
1929 int released __unused;
1931 INP_WLOCK_ASSERT(inp);
1934 * Make sure that all of our timers are stopped before we delete the
1937 * If stopping a timer fails, we schedule a discard function in same
1938 * callout, and the last discard function called will take care of
1939 * deleting the tcpcb.
1941 tp->t_timers->tt_draincnt = 0;
1942 tcp_timer_stop(tp, TT_REXMT);
1943 tcp_timer_stop(tp, TT_PERSIST);
1944 tcp_timer_stop(tp, TT_KEEP);
1945 tcp_timer_stop(tp, TT_2MSL);
1946 tcp_timer_stop(tp, TT_DELACK);
1947 if (tp->t_fb->tfb_tcp_timer_stop_all) {
1949 * Call the stop-all function of the methods,
1950 * this function should call the tcp_timer_stop()
1951 * method with each of the function specific timeouts.
1952 * That stop will be called via the tfb_tcp_timer_stop()
1953 * which should use the async drain function of the
1954 * callout system (see tcp_var.h).
1956 tp->t_fb->tfb_tcp_timer_stop_all(tp);
1960 * If we got enough samples through the srtt filter,
1961 * save the rtt and rttvar in the routing entry.
1962 * 'Enough' is arbitrarily defined as 4 rtt samples.
1963 * 4 samples is enough for the srtt filter to converge
1964 * to within enough % of the correct value; fewer samples
1965 * and we could save a bogus rtt. The danger is not high
1966 * as tcp quickly recovers from everything.
1967 * XXX: Works very well but needs some more statistics!
1969 if (tp->t_rttupdated >= 4) {
1970 struct hc_metrics_lite metrics;
1973 bzero(&metrics, sizeof(metrics));
1975 * Update the ssthresh always when the conditions below
1976 * are satisfied. This gives us better new start value
1977 * for the congestion avoidance for new connections.
1978 * ssthresh is only set if packet loss occurred on a session.
1980 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
1981 * being torn down. Ideally this code would not use 'so'.
1983 ssthresh = tp->snd_ssthresh;
1984 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
1986 * convert the limit from user data bytes to
1987 * packets then to packet data bytes.
1989 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
1992 ssthresh *= (tp->t_maxseg +
1994 (isipv6 ? sizeof (struct ip6_hdr) +
1995 sizeof (struct tcphdr) :
1997 sizeof (struct tcpiphdr)
2004 metrics.rmx_ssthresh = ssthresh;
2006 metrics.rmx_rtt = tp->t_srtt;
2007 metrics.rmx_rttvar = tp->t_rttvar;
2008 metrics.rmx_cwnd = tp->snd_cwnd;
2009 metrics.rmx_sendpipe = 0;
2010 metrics.rmx_recvpipe = 0;
2012 tcp_hc_update(&inp->inp_inc, &metrics);
2015 /* free the reassembly queue, if any */
2016 tcp_reass_flush(tp);
2019 /* Disconnect offload device, if any. */
2020 if (tp->t_flags & TF_TOE)
2021 tcp_offload_detach(tp);
2024 tcp_free_sackholes(tp);
2027 /* Free the TCP PCAP queues. */
2028 tcp_pcap_drain(&(tp->t_inpkts));
2029 tcp_pcap_drain(&(tp->t_outpkts));
2032 /* Allow the CC algorithm to clean up after itself. */
2033 if (CC_ALGO(tp)->cb_destroy != NULL)
2034 CC_ALGO(tp)->cb_destroy(tp->ccv);
2038 khelp_destroy_osd(tp->osd);
2041 stats_blob_destroy(tp->t_stats);
2045 inp->inp_ppcb = NULL;
2046 if (tp->t_timers->tt_draincnt == 0) {
2047 /* We own the last reference on tcpcb, let's free it. */
2049 tcp_log_tcpcbfini(tp);
2051 TCPSTATES_DEC(tp->t_state);
2052 if (tp->t_fb->tfb_tcp_fb_fini)
2053 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2054 refcount_release(&tp->t_fb->tfb_refcnt);
2056 uma_zfree(V_tcpcb_zone, tp);
2057 released = in_pcbrele_wlocked(inp);
2058 KASSERT(!released, ("%s: inp %p should not have been released "
2059 "here", __func__, inp));
2064 tcp_timer_discard(void *ptp)
2068 struct epoch_tracker et;
2070 tp = (struct tcpcb *)ptp;
2071 CURVNET_SET(tp->t_vnet);
2072 NET_EPOCH_ENTER(et);
2074 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL",
2077 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0,
2078 ("%s: tcpcb has to be stopped here", __func__));
2079 tp->t_timers->tt_draincnt--;
2080 if (tp->t_timers->tt_draincnt == 0) {
2081 /* We own the last reference on this tcpcb, let's free it. */
2083 tcp_log_tcpcbfini(tp);
2085 TCPSTATES_DEC(tp->t_state);
2086 if (tp->t_fb->tfb_tcp_fb_fini)
2087 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2088 refcount_release(&tp->t_fb->tfb_refcnt);
2090 uma_zfree(V_tcpcb_zone, tp);
2091 if (in_pcbrele_wlocked(inp)) {
2103 * Attempt to close a TCP control block, marking it as dropped, and freeing
2104 * the socket if we hold the only reference.
2107 tcp_close(struct tcpcb *tp)
2109 struct inpcb *inp = tp->t_inpcb;
2112 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
2113 INP_WLOCK_ASSERT(inp);
2116 if (tp->t_state == TCPS_LISTEN)
2117 tcp_offload_listen_stop(tp);
2120 * This releases the TFO pending counter resource for TFO listen
2121 * sockets as well as passively-created TFO sockets that transition
2122 * from SYN_RECEIVED to CLOSED.
2124 if (tp->t_tfo_pending) {
2125 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
2126 tp->t_tfo_pending = NULL;
2129 TCPSTAT_INC(tcps_closed);
2130 if (tp->t_state != TCPS_CLOSED)
2131 tcp_state_change(tp, TCPS_CLOSED);
2132 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
2133 so = inp->inp_socket;
2134 soisdisconnected(so);
2135 if (inp->inp_flags & INP_SOCKREF) {
2136 KASSERT(so->so_state & SS_PROTOREF,
2137 ("tcp_close: !SS_PROTOREF"));
2138 inp->inp_flags &= ~INP_SOCKREF;
2141 so->so_state &= ~SS_PROTOREF;
2151 VNET_ITERATOR_DECL(vnet_iter);
2156 VNET_LIST_RLOCK_NOSLEEP();
2157 VNET_FOREACH(vnet_iter) {
2158 CURVNET_SET(vnet_iter);
2163 * Walk the tcpbs, if existing, and flush the reassembly queue,
2164 * if there is one...
2165 * XXX: The "Net/3" implementation doesn't imply that the TCP
2166 * reassembly queue should be flushed, but in a situation
2167 * where we're really low on mbufs, this is potentially
2170 INP_INFO_WLOCK(&V_tcbinfo);
2171 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
2173 if (inpb->inp_flags & INP_TIMEWAIT) {
2177 if ((tcpb = intotcpcb(inpb)) != NULL) {
2178 tcp_reass_flush(tcpb);
2179 tcp_clean_sackreport(tcpb);
2181 tcp_log_drain(tcpb);
2184 if (tcp_pcap_aggressive_free) {
2185 /* Free the TCP PCAP queues. */
2186 tcp_pcap_drain(&(tcpb->t_inpkts));
2187 tcp_pcap_drain(&(tcpb->t_outpkts));
2193 INP_INFO_WUNLOCK(&V_tcbinfo);
2196 VNET_LIST_RUNLOCK_NOSLEEP();
2200 * Notify a tcp user of an asynchronous error;
2201 * store error as soft error, but wake up user
2202 * (for now, won't do anything until can select for soft error).
2204 * Do not wake up user since there currently is no mechanism for
2205 * reporting soft errors (yet - a kqueue filter may be added).
2207 static struct inpcb *
2208 tcp_notify(struct inpcb *inp, int error)
2212 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
2213 INP_WLOCK_ASSERT(inp);
2215 if ((inp->inp_flags & INP_TIMEWAIT) ||
2216 (inp->inp_flags & INP_DROPPED))
2219 tp = intotcpcb(inp);
2220 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
2223 * Ignore some errors if we are hooked up.
2224 * If connection hasn't completed, has retransmitted several times,
2225 * and receives a second error, give up now. This is better
2226 * than waiting a long time to establish a connection that
2227 * can never complete.
2229 if (tp->t_state == TCPS_ESTABLISHED &&
2230 (error == EHOSTUNREACH || error == ENETUNREACH ||
2231 error == EHOSTDOWN)) {
2232 if (inp->inp_route.ro_nh) {
2233 NH_FREE(inp->inp_route.ro_nh);
2234 inp->inp_route.ro_nh = (struct nhop_object *)NULL;
2237 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
2239 tp = tcp_drop(tp, error);
2245 tp->t_softerror = error;
2249 wakeup( &so->so_timeo);
2256 tcp_pcblist(SYSCTL_HANDLER_ARGS)
2258 struct epoch_tracker et;
2263 if (req->newptr != NULL)
2266 if (req->oldptr == NULL) {
2269 n = V_tcbinfo.ipi_count +
2270 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2271 n += imax(n / 8, 10);
2272 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
2276 if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
2279 bzero(&xig, sizeof(xig));
2280 xig.xig_len = sizeof xig;
2281 xig.xig_count = V_tcbinfo.ipi_count +
2282 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2283 xig.xig_gen = V_tcbinfo.ipi_gencnt;
2284 xig.xig_sogen = so_gencnt;
2285 error = SYSCTL_OUT(req, &xig, sizeof xig);
2289 error = syncache_pcblist(req);
2293 NET_EPOCH_ENTER(et);
2294 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead);
2296 inp = CK_LIST_NEXT(inp, inp_list)) {
2298 if (inp->inp_gencnt <= xig.xig_gen) {
2302 * XXX: This use of cr_cansee(), introduced with
2303 * TCP state changes, is not quite right, but for
2304 * now, better than nothing.
2306 if (inp->inp_flags & INP_TIMEWAIT) {
2307 if (intotw(inp) != NULL)
2308 crerr = cr_cansee(req->td->td_ucred,
2309 intotw(inp)->tw_cred);
2311 crerr = EINVAL; /* Skip this inp. */
2313 crerr = cr_canseeinpcb(req->td->td_ucred, inp);
2317 tcp_inptoxtp(inp, &xt);
2319 error = SYSCTL_OUT(req, &xt, sizeof xt);
2332 * Give the user an updated idea of our state.
2333 * If the generation differs from what we told
2334 * her before, she knows that something happened
2335 * while we were processing this request, and it
2336 * might be necessary to retry.
2338 xig.xig_gen = V_tcbinfo.ipi_gencnt;
2339 xig.xig_sogen = so_gencnt;
2340 xig.xig_count = V_tcbinfo.ipi_count +
2341 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2342 error = SYSCTL_OUT(req, &xig, sizeof xig);
2348 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
2349 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
2350 NULL, 0, tcp_pcblist, "S,xtcpcb",
2351 "List of active TCP connections");
2355 tcp_getcred(SYSCTL_HANDLER_ARGS)
2358 struct sockaddr_in addrs[2];
2359 struct epoch_tracker et;
2363 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2366 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2369 NET_EPOCH_ENTER(et);
2370 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
2371 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
2374 if (inp->inp_socket == NULL)
2377 error = cr_canseeinpcb(req->td->td_ucred, inp);
2379 cru2x(inp->inp_cred, &xuc);
2384 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2388 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
2389 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT,
2390 0, 0, tcp_getcred, "S,xucred",
2391 "Get the xucred of a TCP connection");
2396 tcp6_getcred(SYSCTL_HANDLER_ARGS)
2398 struct epoch_tracker et;
2400 struct sockaddr_in6 addrs[2];
2407 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2410 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2413 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
2414 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
2417 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
2419 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
2426 NET_EPOCH_ENTER(et);
2429 inp = in_pcblookup(&V_tcbinfo,
2430 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
2432 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
2433 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
2436 inp = in6_pcblookup(&V_tcbinfo,
2437 &addrs[1].sin6_addr, addrs[1].sin6_port,
2438 &addrs[0].sin6_addr, addrs[0].sin6_port,
2439 INPLOOKUP_RLOCKPCB, NULL);
2442 if (inp->inp_socket == NULL)
2445 error = cr_canseeinpcb(req->td->td_ucred, inp);
2447 cru2x(inp->inp_cred, &xuc);
2452 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2456 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
2457 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT,
2458 0, 0, tcp6_getcred, "S,xucred",
2459 "Get the xucred of a TCP6 connection");
2464 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
2466 struct ip *ip = vip;
2468 struct in_addr faddr;
2471 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
2473 struct in_conninfo inc;
2474 tcp_seq icmp_tcp_seq;
2477 faddr = ((struct sockaddr_in *)sa)->sin_addr;
2478 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
2481 if (cmd == PRC_MSGSIZE)
2482 notify = tcp_mtudisc_notify;
2483 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
2484 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL ||
2485 cmd == PRC_TIMXCEED_INTRANS) && ip)
2486 notify = tcp_drop_syn_sent;
2489 * Hostdead is ugly because it goes linearly through all PCBs.
2490 * XXX: We never get this from ICMP, otherwise it makes an
2491 * excellent DoS attack on machines with many connections.
2493 else if (cmd == PRC_HOSTDEAD)
2495 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
2499 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
2503 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip));
2504 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2));
2505 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src,
2506 th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
2507 if (inp != NULL && PRC_IS_REDIRECT(cmd)) {
2508 /* signal EHOSTDOWN, as it flushes the cached route */
2509 inp = (*notify)(inp, EHOSTDOWN);
2512 icmp_tcp_seq = th->th_seq;
2514 if (!(inp->inp_flags & INP_TIMEWAIT) &&
2515 !(inp->inp_flags & INP_DROPPED) &&
2516 !(inp->inp_socket == NULL)) {
2517 tp = intotcpcb(inp);
2518 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
2519 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
2520 if (cmd == PRC_MSGSIZE) {
2523 * If we got a needfrag set the MTU
2524 * in the route to the suggested new
2525 * value (if given) and then notify.
2527 mtu = ntohs(icp->icmp_nextmtu);
2529 * If no alternative MTU was
2530 * proposed, try the next smaller
2535 ntohs(ip->ip_len), 1);
2536 if (mtu < V_tcp_minmss +
2537 sizeof(struct tcpiphdr))
2538 mtu = V_tcp_minmss +
2539 sizeof(struct tcpiphdr);
2541 * Only process the offered MTU if it
2542 * is smaller than the current one.
2544 if (mtu < tp->t_maxseg +
2545 sizeof(struct tcpiphdr)) {
2546 bzero(&inc, sizeof(inc));
2547 inc.inc_faddr = faddr;
2549 inp->inp_inc.inc_fibnum;
2550 tcp_hc_updatemtu(&inc, mtu);
2551 tcp_mtudisc(inp, mtu);
2554 inp = (*notify)(inp,
2555 inetctlerrmap[cmd]);
2559 bzero(&inc, sizeof(inc));
2560 inc.inc_fport = th->th_dport;
2561 inc.inc_lport = th->th_sport;
2562 inc.inc_faddr = faddr;
2563 inc.inc_laddr = ip->ip_src;
2564 syncache_unreach(&inc, icmp_tcp_seq);
2574 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
2576 struct in6_addr *dst;
2577 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
2578 struct ip6_hdr *ip6;
2582 struct icmp6_hdr *icmp6;
2583 struct ip6ctlparam *ip6cp = NULL;
2584 const struct sockaddr_in6 *sa6_src = NULL;
2585 struct in_conninfo inc;
2590 tcp_seq icmp_tcp_seq;
2594 if (sa->sa_family != AF_INET6 ||
2595 sa->sa_len != sizeof(struct sockaddr_in6))
2598 /* if the parameter is from icmp6, decode it. */
2600 ip6cp = (struct ip6ctlparam *)d;
2601 icmp6 = ip6cp->ip6c_icmp6;
2603 ip6 = ip6cp->ip6c_ip6;
2604 off = ip6cp->ip6c_off;
2605 sa6_src = ip6cp->ip6c_src;
2606 dst = ip6cp->ip6c_finaldst;
2610 off = 0; /* fool gcc */
2615 if (cmd == PRC_MSGSIZE)
2616 notify = tcp_mtudisc_notify;
2617 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
2618 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL ||
2619 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL)
2620 notify = tcp_drop_syn_sent;
2623 * Hostdead is ugly because it goes linearly through all PCBs.
2624 * XXX: We never get this from ICMP, otherwise it makes an
2625 * excellent DoS attack on machines with many connections.
2627 else if (cmd == PRC_HOSTDEAD)
2629 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)
2633 in6_pcbnotify(&V_tcbinfo, sa, 0,
2634 (const struct sockaddr *)sa6_src,
2635 0, cmd, NULL, notify);
2639 /* Check if we can safely get the ports from the tcp hdr */
2642 (int32_t) (off + sizeof(struct tcp_ports)))) {
2645 bzero(&t_ports, sizeof(struct tcp_ports));
2646 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports);
2647 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport,
2648 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL);
2649 if (inp != NULL && PRC_IS_REDIRECT(cmd)) {
2650 /* signal EHOSTDOWN, as it flushes the cached route */
2651 inp = (*notify)(inp, EHOSTDOWN);
2654 off += sizeof(struct tcp_ports);
2655 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) {
2658 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq);
2660 if (!(inp->inp_flags & INP_TIMEWAIT) &&
2661 !(inp->inp_flags & INP_DROPPED) &&
2662 !(inp->inp_socket == NULL)) {
2663 tp = intotcpcb(inp);
2664 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
2665 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
2666 if (cmd == PRC_MSGSIZE) {
2669 * If we got a needfrag set the MTU
2670 * in the route to the suggested new
2671 * value (if given) and then notify.
2673 mtu = ntohl(icmp6->icmp6_mtu);
2675 * If no alternative MTU was
2676 * proposed, or the proposed
2677 * MTU was too small, set to
2680 if (mtu < IPV6_MMTU)
2681 mtu = IPV6_MMTU - 8;
2682 bzero(&inc, sizeof(inc));
2683 inc.inc_fibnum = M_GETFIB(m);
2684 inc.inc_flags |= INC_ISIPV6;
2685 inc.inc6_faddr = *dst;
2686 if (in6_setscope(&inc.inc6_faddr,
2687 m->m_pkthdr.rcvif, NULL))
2690 * Only process the offered MTU if it
2691 * is smaller than the current one.
2693 if (mtu < tp->t_maxseg +
2694 sizeof (struct tcphdr) +
2695 sizeof (struct ip6_hdr)) {
2696 tcp_hc_updatemtu(&inc, mtu);
2697 tcp_mtudisc(inp, mtu);
2698 ICMP6STAT_INC(icp6s_pmtuchg);
2701 inp = (*notify)(inp,
2702 inet6ctlerrmap[cmd]);
2706 bzero(&inc, sizeof(inc));
2707 inc.inc_fibnum = M_GETFIB(m);
2708 inc.inc_flags |= INC_ISIPV6;
2709 inc.inc_fport = t_ports.th_dport;
2710 inc.inc_lport = t_ports.th_sport;
2711 inc.inc6_faddr = *dst;
2712 inc.inc6_laddr = ip6->ip6_src;
2713 syncache_unreach(&inc, icmp_tcp_seq);
2722 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len)
2727 KASSERT(len >= SIPHASH_KEY_LENGTH,
2728 ("%s: keylen %u too short ", __func__, len));
2729 SipHash24_Init(&ctx);
2730 SipHash_SetKey(&ctx, (uint8_t *)key);
2731 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t));
2732 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t));
2733 switch (inc->inc_flags & INC_ISIPV6) {
2736 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr));
2737 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr));
2742 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr));
2743 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr));
2747 SipHash_Final((uint8_t *)hash, &ctx);
2749 return (hash[0] ^ hash[1]);
2753 tcp_new_ts_offset(struct in_conninfo *inc)
2755 struct in_conninfo inc_store, *local_inc;
2757 if (!V_tcp_ts_offset_per_conn) {
2758 memcpy(&inc_store, inc, sizeof(struct in_conninfo));
2759 inc_store.inc_lport = 0;
2760 inc_store.inc_fport = 0;
2761 local_inc = &inc_store;
2765 return (tcp_keyed_hash(local_inc, V_ts_offset_secret,
2766 sizeof(V_ts_offset_secret)));
2770 * Following is where TCP initial sequence number generation occurs.
2772 * There are two places where we must use initial sequence numbers:
2773 * 1. In SYN-ACK packets.
2774 * 2. In SYN packets.
2776 * All ISNs for SYN-ACK packets are generated by the syncache. See
2777 * tcp_syncache.c for details.
2779 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
2780 * depends on this property. In addition, these ISNs should be
2781 * unguessable so as to prevent connection hijacking. To satisfy
2782 * the requirements of this situation, the algorithm outlined in
2783 * RFC 1948 is used, with only small modifications.
2785 * Implementation details:
2787 * Time is based off the system timer, and is corrected so that it
2788 * increases by one megabyte per second. This allows for proper
2789 * recycling on high speed LANs while still leaving over an hour
2792 * As reading the *exact* system time is too expensive to be done
2793 * whenever setting up a TCP connection, we increment the time
2794 * offset in two ways. First, a small random positive increment
2795 * is added to isn_offset for each connection that is set up.
2796 * Second, the function tcp_isn_tick fires once per clock tick
2797 * and increments isn_offset as necessary so that sequence numbers
2798 * are incremented at approximately ISN_BYTES_PER_SECOND. The
2799 * random positive increments serve only to ensure that the same
2800 * exact sequence number is never sent out twice (as could otherwise
2801 * happen when a port is recycled in less than the system tick
2804 * net.inet.tcp.isn_reseed_interval controls the number of seconds
2805 * between seeding of isn_secret. This is normally set to zero,
2806 * as reseeding should not be necessary.
2808 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
2809 * isn_offset_old, and isn_ctx is performed using the ISN lock. In
2810 * general, this means holding an exclusive (write) lock.
2813 #define ISN_BYTES_PER_SECOND 1048576
2814 #define ISN_STATIC_INCREMENT 4096
2815 #define ISN_RANDOM_INCREMENT (4096 - 1)
2816 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH
2818 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]);
2819 VNET_DEFINE_STATIC(int, isn_last);
2820 VNET_DEFINE_STATIC(int, isn_last_reseed);
2821 VNET_DEFINE_STATIC(u_int32_t, isn_offset);
2822 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old);
2824 #define V_isn_secret VNET(isn_secret)
2825 #define V_isn_last VNET(isn_last)
2826 #define V_isn_last_reseed VNET(isn_last_reseed)
2827 #define V_isn_offset VNET(isn_offset)
2828 #define V_isn_offset_old VNET(isn_offset_old)
2831 tcp_new_isn(struct in_conninfo *inc)
2834 u_int32_t projected_offset;
2837 /* Seed if this is the first use, reseed if requested. */
2838 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
2839 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
2841 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0);
2842 V_isn_last_reseed = ticks;
2845 /* Compute the hash and return the ISN. */
2846 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret,
2847 sizeof(V_isn_secret));
2848 V_isn_offset += ISN_STATIC_INCREMENT +
2849 (arc4random() & ISN_RANDOM_INCREMENT);
2850 if (ticks != V_isn_last) {
2851 projected_offset = V_isn_offset_old +
2852 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
2853 if (SEQ_GT(projected_offset, V_isn_offset))
2854 V_isn_offset = projected_offset;
2855 V_isn_offset_old = V_isn_offset;
2858 new_isn += V_isn_offset;
2864 * When a specific ICMP unreachable message is received and the
2865 * connection state is SYN-SENT, drop the connection. This behavior
2866 * is controlled by the icmp_may_rst sysctl.
2869 tcp_drop_syn_sent(struct inpcb *inp, int errno)
2874 INP_WLOCK_ASSERT(inp);
2876 if ((inp->inp_flags & INP_TIMEWAIT) ||
2877 (inp->inp_flags & INP_DROPPED))
2880 tp = intotcpcb(inp);
2881 if (tp->t_state != TCPS_SYN_SENT)
2884 if (IS_FASTOPEN(tp->t_flags))
2885 tcp_fastopen_disable_path(tp);
2887 tp = tcp_drop(tp, errno);
2895 * When `need fragmentation' ICMP is received, update our idea of the MSS
2896 * based on the new value. Also nudge TCP to send something, since we
2897 * know the packet we just sent was dropped.
2898 * This duplicates some code in the tcp_mss() function in tcp_input.c.
2900 static struct inpcb *
2901 tcp_mtudisc_notify(struct inpcb *inp, int error)
2904 tcp_mtudisc(inp, -1);
2909 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
2914 INP_WLOCK_ASSERT(inp);
2915 if ((inp->inp_flags & INP_TIMEWAIT) ||
2916 (inp->inp_flags & INP_DROPPED))
2919 tp = intotcpcb(inp);
2920 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
2922 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
2924 so = inp->inp_socket;
2925 SOCKBUF_LOCK(&so->so_snd);
2926 /* If the mss is larger than the socket buffer, decrease the mss. */
2927 if (so->so_snd.sb_hiwat < tp->t_maxseg)
2928 tp->t_maxseg = so->so_snd.sb_hiwat;
2929 SOCKBUF_UNLOCK(&so->so_snd);
2931 TCPSTAT_INC(tcps_mturesent);
2933 tp->snd_nxt = tp->snd_una;
2934 tcp_free_sackholes(tp);
2935 tp->snd_recover = tp->snd_max;
2936 if (tp->t_flags & TF_SACK_PERMIT)
2937 EXIT_FASTRECOVERY(tp->t_flags);
2938 tp->t_fb->tfb_tcp_output(tp);
2943 * Look-up the routing entry to the peer of this inpcb. If no route
2944 * is found and it cannot be allocated, then return 0. This routine
2945 * is called by TCP routines that access the rmx structure and by
2946 * tcp_mss_update to get the peer/interface MTU.
2949 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
2951 struct nhop_object *nh;
2953 uint32_t maxmtu = 0;
2955 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
2957 if (inc->inc_faddr.s_addr != INADDR_ANY) {
2958 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0);
2963 maxmtu = nh->nh_mtu;
2965 /* Report additional interface capabilities. */
2967 if (ifp->if_capenable & IFCAP_TSO4 &&
2968 ifp->if_hwassist & CSUM_TSO) {
2969 cap->ifcap |= CSUM_TSO;
2970 cap->tsomax = ifp->if_hw_tsomax;
2971 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
2972 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
2982 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
2984 struct nhop_object *nh;
2985 struct in6_addr dst6;
2988 uint32_t maxmtu = 0;
2990 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
2992 if (inc->inc_flags & INC_IPV6MINMTU)
2995 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
2996 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid);
2997 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0);
3002 maxmtu = nh->nh_mtu;
3004 /* Report additional interface capabilities. */
3006 if (ifp->if_capenable & IFCAP_TSO6 &&
3007 ifp->if_hwassist & CSUM_TSO) {
3008 cap->ifcap |= CSUM_TSO;
3009 cap->tsomax = ifp->if_hw_tsomax;
3010 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
3011 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
3021 * Calculate effective SMSS per RFC5681 definition for a given TCP
3022 * connection at its current state, taking into account SACK and etc.
3025 tcp_maxseg(const struct tcpcb *tp)
3029 if (tp->t_flags & TF_NOOPT)
3030 return (tp->t_maxseg);
3033 * Here we have a simplified code from tcp_addoptions(),
3034 * without a proper loop, and having most of paddings hardcoded.
3035 * We might make mistakes with padding here in some edge cases,
3036 * but this is harmless, since result of tcp_maxseg() is used
3037 * only in cwnd and ssthresh estimations.
3039 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
3040 if (tp->t_flags & TF_RCVD_TSTMP)
3041 optlen = TCPOLEN_TSTAMP_APPA;
3044 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3045 if (tp->t_flags & TF_SIGNATURE)
3046 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3048 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) {
3049 optlen += TCPOLEN_SACKHDR;
3050 optlen += tp->rcv_numsacks * TCPOLEN_SACK;
3051 optlen = PADTCPOLEN(optlen);
3054 if (tp->t_flags & TF_REQ_TSTMP)
3055 optlen = TCPOLEN_TSTAMP_APPA;
3057 optlen = PADTCPOLEN(TCPOLEN_MAXSEG);
3058 if (tp->t_flags & TF_REQ_SCALE)
3059 optlen += PADTCPOLEN(TCPOLEN_WINDOW);
3060 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3061 if (tp->t_flags & TF_SIGNATURE)
3062 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3064 if (tp->t_flags & TF_SACK_PERMIT)
3065 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED);
3068 optlen = min(optlen, TCP_MAXOLEN);
3069 return (tp->t_maxseg - optlen);
3073 sysctl_drop(SYSCTL_HANDLER_ARGS)
3075 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
3076 struct sockaddr_storage addrs[2];
3080 struct sockaddr_in *fin, *lin;
3081 struct epoch_tracker et;
3083 struct sockaddr_in6 *fin6, *lin6;
3094 if (req->oldptr != NULL || req->oldlen != 0)
3096 if (req->newptr == NULL)
3098 if (req->newlen < sizeof(addrs))
3100 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
3104 switch (addrs[0].ss_family) {
3107 fin6 = (struct sockaddr_in6 *)&addrs[0];
3108 lin6 = (struct sockaddr_in6 *)&addrs[1];
3109 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
3110 lin6->sin6_len != sizeof(struct sockaddr_in6))
3112 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
3113 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
3115 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
3116 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
3117 fin = (struct sockaddr_in *)&addrs[0];
3118 lin = (struct sockaddr_in *)&addrs[1];
3121 error = sa6_embedscope(fin6, V_ip6_use_defzone);
3124 error = sa6_embedscope(lin6, V_ip6_use_defzone);
3131 fin = (struct sockaddr_in *)&addrs[0];
3132 lin = (struct sockaddr_in *)&addrs[1];
3133 if (fin->sin_len != sizeof(struct sockaddr_in) ||
3134 lin->sin_len != sizeof(struct sockaddr_in))
3141 NET_EPOCH_ENTER(et);
3142 switch (addrs[0].ss_family) {
3145 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
3146 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
3147 INPLOOKUP_WLOCKPCB, NULL);
3152 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
3153 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
3158 if (inp->inp_flags & INP_TIMEWAIT) {
3160 * XXXRW: There currently exists a state where an
3161 * inpcb is present, but its timewait state has been
3162 * discarded. For now, don't allow dropping of this
3170 } else if (!(inp->inp_flags & INP_DROPPED) &&
3171 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
3172 tp = intotcpcb(inp);
3173 tp = tcp_drop(tp, ECONNABORTED);
3184 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
3185 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3186 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "",
3187 "Drop TCP connection");
3191 sysctl_switch_tls(SYSCTL_HANDLER_ARGS)
3193 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
3194 struct sockaddr_storage addrs[2];
3196 struct sockaddr_in *fin, *lin;
3197 struct epoch_tracker et;
3199 struct sockaddr_in6 *fin6, *lin6;
3210 if (req->oldptr != NULL || req->oldlen != 0)
3212 if (req->newptr == NULL)
3214 if (req->newlen < sizeof(addrs))
3216 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
3220 switch (addrs[0].ss_family) {
3223 fin6 = (struct sockaddr_in6 *)&addrs[0];
3224 lin6 = (struct sockaddr_in6 *)&addrs[1];
3225 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
3226 lin6->sin6_len != sizeof(struct sockaddr_in6))
3228 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
3229 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
3231 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
3232 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
3233 fin = (struct sockaddr_in *)&addrs[0];
3234 lin = (struct sockaddr_in *)&addrs[1];
3237 error = sa6_embedscope(fin6, V_ip6_use_defzone);
3240 error = sa6_embedscope(lin6, V_ip6_use_defzone);
3247 fin = (struct sockaddr_in *)&addrs[0];
3248 lin = (struct sockaddr_in *)&addrs[1];
3249 if (fin->sin_len != sizeof(struct sockaddr_in) ||
3250 lin->sin_len != sizeof(struct sockaddr_in))
3257 NET_EPOCH_ENTER(et);
3258 switch (addrs[0].ss_family) {
3261 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
3262 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
3263 INPLOOKUP_WLOCKPCB, NULL);
3268 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
3269 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
3275 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 ||
3276 inp->inp_socket == NULL) {
3282 so = inp->inp_socket;
3284 error = ktls_set_tx_mode(so,
3285 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET);
3295 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls,
3296 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3297 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "",
3298 "Switch TCP connection to SW TLS");
3299 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls,
3300 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3301 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "",
3302 "Switch TCP connection to ifnet TLS");
3306 * Generate a standardized TCP log line for use throughout the
3307 * tcp subsystem. Memory allocation is done with M_NOWAIT to
3308 * allow use in the interrupt context.
3310 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
3311 * NB: The function may return NULL if memory allocation failed.
3313 * Due to header inclusion and ordering limitations the struct ip
3314 * and ip6_hdr pointers have to be passed as void pointers.
3317 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3321 /* Is logging enabled? */
3322 if (V_tcp_log_in_vain == 0)
3325 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3329 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3333 /* Is logging enabled? */
3334 if (tcp_log_debug == 0)
3337 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3341 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3348 const struct ip6_hdr *ip6;
3350 ip6 = (const struct ip6_hdr *)ip6hdr;
3352 ip = (struct ip *)ip4hdr;
3355 * The log line looks like this:
3356 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
3358 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
3359 sizeof(PRINT_TH_FLAGS) + 1 +
3361 2 * INET6_ADDRSTRLEN;
3363 2 * INET_ADDRSTRLEN;
3366 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
3370 strcat(s, "TCP: [");
3373 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
3374 inet_ntoa_r(inc->inc_faddr, sp);
3376 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3378 inet_ntoa_r(inc->inc_laddr, sp);
3380 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3383 ip6_sprintf(sp, &inc->inc6_faddr);
3385 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3387 ip6_sprintf(sp, &inc->inc6_laddr);
3389 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3390 } else if (ip6 && th) {
3391 ip6_sprintf(sp, &ip6->ip6_src);
3393 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3395 ip6_sprintf(sp, &ip6->ip6_dst);
3397 sprintf(sp, "]:%i", ntohs(th->th_dport));
3400 } else if (ip && th) {
3401 inet_ntoa_r(ip->ip_src, sp);
3403 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3405 inet_ntoa_r(ip->ip_dst, sp);
3407 sprintf(sp, "]:%i", ntohs(th->th_dport));
3415 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
3416 if (*(s + size - 1) != '\0')
3417 panic("%s: string too long", __func__);
3422 * A subroutine which makes it easy to track TCP state changes with DTrace.
3423 * This function shouldn't be called for t_state initializations that don't
3424 * correspond to actual TCP state transitions.
3427 tcp_state_change(struct tcpcb *tp, int newstate)
3429 #if defined(KDTRACE_HOOKS)
3430 int pstate = tp->t_state;
3433 TCPSTATES_DEC(tp->t_state);
3434 TCPSTATES_INC(newstate);
3435 tp->t_state = newstate;
3436 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);
3440 * Create an external-format (``xtcpcb'') structure using the information in
3441 * the kernel-format tcpcb structure pointed to by tp. This is done to
3442 * reduce the spew of irrelevant information over this interface, to isolate
3443 * user code from changes in the kernel structure, and potentially to provide
3444 * information-hiding if we decide that some of this information should be
3445 * hidden from users.
3448 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt)
3450 struct tcpcb *tp = intotcpcb(inp);
3453 bzero(xt, sizeof(*xt));
3454 if (inp->inp_flags & INP_TIMEWAIT) {
3455 xt->t_state = TCPS_TIME_WAIT;
3457 xt->t_state = tp->t_state;
3458 xt->t_logstate = tp->t_logstate;
3459 xt->t_flags = tp->t_flags;
3460 xt->t_sndzerowin = tp->t_sndzerowin;
3461 xt->t_sndrexmitpack = tp->t_sndrexmitpack;
3462 xt->t_rcvoopack = tp->t_rcvoopack;
3463 xt->t_rcv_wnd = tp->rcv_wnd;
3464 xt->t_snd_wnd = tp->snd_wnd;
3465 xt->t_snd_cwnd = tp->snd_cwnd;
3466 xt->t_snd_ssthresh = tp->snd_ssthresh;
3467 xt->t_maxseg = tp->t_maxseg;
3468 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 +
3469 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0;
3471 now = getsbinuptime();
3472 #define COPYTIMER(ttt) do { \
3473 if (callout_active(&tp->t_timers->ttt)) \
3474 xt->ttt = (tp->t_timers->ttt.c_time - now) / \
3479 COPYTIMER(tt_delack);
3480 COPYTIMER(tt_rexmt);
3481 COPYTIMER(tt_persist);
3485 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz;
3487 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack,
3488 TCP_FUNCTION_NAME_LEN_MAX);
3489 bcopy(CC_ALGO(tp)->name, xt->xt_cc,
3492 (void)tcp_log_get_id(tp, xt->xt_logid);
3496 xt->xt_len = sizeof(struct xtcpcb);
3497 in_pcbtoxinpcb(inp, &xt->xt_inp);
3498 if (inp->inp_socket == NULL)
3499 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP;
3503 tcp_log_end_status(struct tcpcb *tp, uint8_t status)
3508 (status > TCP_EI_STATUS_MAX_VALUE) ||
3513 if (status > (sizeof(uint32_t) * 8)) {
3514 /* Should this be a KASSERT? */
3517 bit = 1U << (status - 1);
3518 if (bit & tp->t_end_info_status) {
3519 /* already logged */
3522 for (i = 0; i < TCP_END_BYTE_INFO; i++) {
3523 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) {
3524 tp->t_end_info_bytes[i] = status;
3525 tp->t_end_info_status |= bit;