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)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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_tcpdebug.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/callout.h>
45 #include <sys/eventhandler.h>
47 #include <sys/hhook.h>
49 #include <sys/kernel.h>
51 #include <sys/khelp.h>
53 #include <sys/sysctl.h>
55 #include <sys/malloc.h>
56 #include <sys/refcount.h>
59 #include <sys/domain.h>
64 #include <sys/socket.h>
65 #include <sys/socketvar.h>
66 #include <sys/protosw.h>
67 #include <sys/random.h>
71 #include <net/route.h>
73 #include <net/if_var.h>
76 #include <netinet/in.h>
77 #include <netinet/in_fib.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/in_systm.h>
81 #include <netinet/in_var.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>
84 #include <netinet/ip_var.h>
86 #include <netinet/icmp6.h>
87 #include <netinet/ip6.h>
88 #include <netinet6/in6_fib.h>
89 #include <netinet6/in6_pcb.h>
90 #include <netinet6/ip6_var.h>
91 #include <netinet6/scope6_var.h>
92 #include <netinet6/nd6.h>
95 #include <netinet/tcp.h>
96 #include <netinet/tcp_fsm.h>
97 #include <netinet/tcp_seq.h>
98 #include <netinet/tcp_timer.h>
99 #include <netinet/tcp_var.h>
100 #include <netinet/tcp_log_buf.h>
101 #include <netinet/tcp_syncache.h>
102 #include <netinet/tcp_hpts.h>
103 #include <netinet/cc/cc.h>
105 #include <netinet6/tcp6_var.h>
107 #include <netinet/tcpip.h>
108 #include <netinet/tcp_fastopen.h>
110 #include <netinet/tcp_pcap.h>
113 #include <netinet/tcp_debug.h>
116 #include <netinet6/ip6protosw.h>
119 #include <netinet/tcp_offload.h>
122 #include <netipsec/ipsec_support.h>
124 #include <machine/in_cksum.h>
127 #include <security/mac/mac_framework.h>
129 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
131 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
134 struct rwlock tcp_function_lock;
137 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
142 error = sysctl_handle_int(oidp, &new, 0, req);
143 if (error == 0 && req->newptr) {
144 if (new < TCP_MINMSS)
152 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
153 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
154 &sysctl_net_inet_tcp_mss_check, "I",
155 "Default TCP Maximum Segment Size");
159 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
163 new = V_tcp_v6mssdflt;
164 error = sysctl_handle_int(oidp, &new, 0, req);
165 if (error == 0 && req->newptr) {
166 if (new < TCP_MINMSS)
169 V_tcp_v6mssdflt = new;
174 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
175 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
176 &sysctl_net_inet_tcp_mss_v6_check, "I",
177 "Default TCP Maximum Segment Size for IPv6");
181 * Minimum MSS we accept and use. This prevents DoS attacks where
182 * we are forced to a ridiculous low MSS like 20 and send hundreds
183 * of packets instead of one. The effect scales with the available
184 * bandwidth and quickly saturates the CPU and network interface
185 * with packet generation and sending. Set to zero to disable MINMSS
186 * checking. This setting prevents us from sending too small packets.
188 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW,
190 &VNET_NAME(tcp_minmss), 0,
191 "Minimum TCP Maximum Segment Size");
193 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
194 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW,
195 &VNET_NAME(tcp_do_rfc1323), 0,
196 "Enable rfc1323 (high performance TCP) extensions");
198 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1;
199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW,
200 &VNET_NAME(tcp_ts_offset_per_conn), 0,
201 "Initialize TCP timestamps per connection instead of per host pair");
203 static int tcp_log_debug = 0;
204 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
205 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
207 static int tcp_tcbhashsize;
208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
209 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
211 static int do_tcpdrain = 1;
212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
213 "Enable tcp_drain routine for extra help when low on mbufs");
215 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD,
216 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
218 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1;
219 #define V_icmp_may_rst VNET(icmp_may_rst)
220 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW,
221 &VNET_NAME(icmp_may_rst), 0,
222 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
224 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0;
225 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW,
227 &VNET_NAME(tcp_isn_reseed_interval), 0,
228 "Seconds between reseeding of ISN secret");
230 static int tcp_soreceive_stream;
231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
232 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
234 VNET_DEFINE(uma_zone_t, sack_hole_zone);
235 #define V_sack_hole_zone VNET(sack_hole_zone)
238 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
241 #define TS_OFFSET_SECRET_LENGTH 32
242 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]);
243 #define V_ts_offset_secret VNET(ts_offset_secret)
245 static int tcp_default_fb_init(struct tcpcb *tp);
246 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged);
247 static int tcp_default_handoff_ok(struct tcpcb *tp);
248 static struct inpcb *tcp_notify(struct inpcb *, int);
249 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
250 static void tcp_mtudisc(struct inpcb *, int);
251 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
252 void *ip4hdr, const void *ip6hdr);
255 static struct tcp_function_block tcp_def_funcblk = {
256 .tfb_tcp_block_name = "freebsd",
257 .tfb_tcp_output = tcp_output,
258 .tfb_tcp_do_segment = tcp_do_segment,
259 .tfb_tcp_ctloutput = tcp_default_ctloutput,
260 .tfb_tcp_handoff_ok = tcp_default_handoff_ok,
261 .tfb_tcp_fb_init = tcp_default_fb_init,
262 .tfb_tcp_fb_fini = tcp_default_fb_fini,
265 static int tcp_fb_cnt = 0;
266 struct tcp_funchead t_functions;
267 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk;
269 static struct tcp_function_block *
270 find_tcp_functions_locked(struct tcp_function_set *fs)
272 struct tcp_function *f;
273 struct tcp_function_block *blk=NULL;
275 TAILQ_FOREACH(f, &t_functions, tf_next) {
276 if (strcmp(f->tf_name, fs->function_set_name) == 0) {
284 static struct tcp_function_block *
285 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s)
287 struct tcp_function_block *rblk=NULL;
288 struct tcp_function *f;
290 TAILQ_FOREACH(f, &t_functions, tf_next) {
291 if (f->tf_fb == blk) {
302 struct tcp_function_block *
303 find_and_ref_tcp_functions(struct tcp_function_set *fs)
305 struct tcp_function_block *blk;
307 rw_rlock(&tcp_function_lock);
308 blk = find_tcp_functions_locked(fs);
310 refcount_acquire(&blk->tfb_refcnt);
311 rw_runlock(&tcp_function_lock);
315 struct tcp_function_block *
316 find_and_ref_tcp_fb(struct tcp_function_block *blk)
318 struct tcp_function_block *rblk;
320 rw_rlock(&tcp_function_lock);
321 rblk = find_tcp_fb_locked(blk, NULL);
323 refcount_acquire(&rblk->tfb_refcnt);
324 rw_runlock(&tcp_function_lock);
328 static struct tcp_function_block *
329 find_and_ref_tcp_default_fb(void)
331 struct tcp_function_block *rblk;
333 rw_rlock(&tcp_function_lock);
334 rblk = tcp_func_set_ptr;
335 refcount_acquire(&rblk->tfb_refcnt);
336 rw_runlock(&tcp_function_lock);
341 tcp_switch_back_to_default(struct tcpcb *tp)
343 struct tcp_function_block *tfb;
345 KASSERT(tp->t_fb != &tcp_def_funcblk,
346 ("%s: called by the built-in default stack", __func__));
349 * Release the old stack. This function will either find a new one
352 if (tp->t_fb->tfb_tcp_fb_fini != NULL)
353 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0);
354 refcount_release(&tp->t_fb->tfb_refcnt);
357 * Now, we'll find a new function block to use.
358 * Start by trying the current user-selected
359 * default, unless this stack is the user-selected
362 tfb = find_and_ref_tcp_default_fb();
363 if (tfb == tp->t_fb) {
364 refcount_release(&tfb->tfb_refcnt);
367 /* Does the stack accept this connection? */
368 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL &&
369 (*tfb->tfb_tcp_handoff_ok)(tp)) {
370 refcount_release(&tfb->tfb_refcnt);
373 /* Try to use that stack. */
375 /* Initialize the new stack. If it succeeds, we are done. */
377 if (tp->t_fb->tfb_tcp_fb_init == NULL ||
378 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0)
382 * Initialization failed. Release the reference count on
385 refcount_release(&tfb->tfb_refcnt);
389 * If that wasn't feasible, use the built-in default
390 * stack which is not allowed to reject anyone.
392 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk);
394 /* there always should be a default */
395 panic("Can't refer to tcp_def_funcblk");
397 if (tfb->tfb_tcp_handoff_ok != NULL) {
398 if ((*tfb->tfb_tcp_handoff_ok) (tp)) {
399 /* The default stack cannot say no */
400 panic("Default stack rejects a new session?");
404 if (tp->t_fb->tfb_tcp_fb_init != NULL &&
405 (*tp->t_fb->tfb_tcp_fb_init)(tp)) {
406 /* The default stack cannot fail */
407 panic("Default stack initialization failed");
412 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)
415 struct tcp_function_set fs;
416 struct tcp_function_block *blk;
418 memset(&fs, 0, sizeof(fs));
419 rw_rlock(&tcp_function_lock);
420 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL);
423 strcpy(fs.function_set_name, blk->tfb_tcp_block_name);
424 fs.pcbcnt = blk->tfb_refcnt;
426 rw_runlock(&tcp_function_lock);
427 error = sysctl_handle_string(oidp, fs.function_set_name,
428 sizeof(fs.function_set_name), req);
430 /* Check for error or no change */
431 if (error != 0 || req->newptr == NULL)
434 rw_wlock(&tcp_function_lock);
435 blk = find_tcp_functions_locked(&fs);
437 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) {
441 tcp_func_set_ptr = blk;
443 rw_wunlock(&tcp_function_lock);
447 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default,
448 CTLTYPE_STRING | CTLFLAG_RW,
449 NULL, 0, sysctl_net_inet_default_tcp_functions, "A",
450 "Set/get the default TCP functions");
453 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS)
455 int error, cnt, linesz;
456 struct tcp_function *f;
462 rw_rlock(&tcp_function_lock);
463 TAILQ_FOREACH(f, &t_functions, tf_next) {
466 rw_runlock(&tcp_function_lock);
468 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1;
469 buffer = malloc(bufsz, M_TEMP, M_WAITOK);
474 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D',
475 "Alias", "PCB count");
480 rw_rlock(&tcp_function_lock);
481 TAILQ_FOREACH(f, &t_functions, tf_next) {
482 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name);
483 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n",
484 f->tf_fb->tfb_tcp_block_name,
485 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ',
486 alias ? f->tf_name : "-",
487 f->tf_fb->tfb_refcnt);
488 if (linesz >= bufsz) {
496 rw_runlock(&tcp_function_lock);
498 error = sysctl_handle_string(oidp, buffer, outsz + 1, req);
499 free(buffer, M_TEMP);
503 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available,
504 CTLTYPE_STRING|CTLFLAG_RD,
505 NULL, 0, sysctl_net_inet_list_available, "A",
506 "list available TCP Function sets");
509 * Exports one (struct tcp_function_info) for each alias/name.
512 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS)
515 struct tcp_function *f;
516 struct tcp_function_info tfi;
519 * We don't allow writes.
521 if (req->newptr != NULL)
525 * Wire the old buffer so we can directly copy the functions to
526 * user space without dropping the lock.
528 if (req->oldptr != NULL) {
529 error = sysctl_wire_old_buffer(req, 0);
535 * Walk the list and copy out matching entries. If INVARIANTS
536 * is compiled in, also walk the list to verify the length of
537 * the list matches what we have recorded.
539 rw_rlock(&tcp_function_lock);
543 if (req->oldptr == NULL) {
548 TAILQ_FOREACH(f, &t_functions, tf_next) {
552 if (req->oldptr != NULL) {
553 bzero(&tfi, sizeof(tfi));
554 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt;
555 tfi.tfi_id = f->tf_fb->tfb_id;
556 (void)strlcpy(tfi.tfi_alias, f->tf_name,
557 sizeof(tfi.tfi_alias));
558 (void)strlcpy(tfi.tfi_name,
559 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name));
560 error = SYSCTL_OUT(req, &tfi, sizeof(tfi));
562 * Don't stop on error, as that is the
563 * mechanism we use to accumulate length
564 * information if the buffer was too short.
568 KASSERT(cnt == tcp_fb_cnt,
569 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt));
573 rw_runlock(&tcp_function_lock);
574 if (req->oldptr == NULL)
575 error = SYSCTL_OUT(req, NULL,
576 (cnt + 1) * sizeof(struct tcp_function_info));
581 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info,
582 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE,
583 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info",
584 "List TCP function block name-to-ID mappings");
587 * tfb_tcp_handoff_ok() function for the default stack.
588 * Note that we'll basically try to take all comers.
591 tcp_default_handoff_ok(struct tcpcb *tp)
598 * tfb_tcp_fb_init() function for the default stack.
600 * This handles making sure we have appropriate timers set if you are
601 * transitioning a socket that has some amount of setup done.
603 * The init() fuction from the default can *never* return non-zero i.e.
604 * it is required to always succeed since it is the stack of last resort!
607 tcp_default_fb_init(struct tcpcb *tp)
612 INP_WLOCK_ASSERT(tp->t_inpcb);
614 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT,
615 ("%s: connection %p in unexpected state %d", __func__, tp,
619 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't
620 * know what to do for unexpected states (which includes TIME_WAIT).
622 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT)
626 * Make sure some kind of transmission timer is set if there is
629 so = tp->t_inpcb->inp_socket;
630 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) ||
631 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) ||
632 tcp_timer_active(tp, TT_PERSIST))) {
634 * If the session has established and it looks like it should
635 * be in the persist state, set the persist timer. Otherwise,
636 * set the retransmit timer.
638 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 &&
639 (int32_t)(tp->snd_nxt - tp->snd_una) <
640 (int32_t)sbavail(&so->so_snd))
643 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur);
646 /* All non-embryonic sessions get a keepalive timer. */
647 if (!tcp_timer_active(tp, TT_KEEP))
648 tcp_timer_activate(tp, TT_KEEP,
649 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) :
656 * tfb_tcp_fb_fini() function for the default stack.
658 * This changes state as necessary (or prudent) to prepare for another stack
659 * to assume responsibility for the connection.
662 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged)
665 INP_WLOCK_ASSERT(tp->t_inpcb);
670 * Target size of TCP PCB hash tables. Must be a power of two.
672 * Note that this can be overridden by the kernel environment
673 * variable net.inet.tcp.tcbhashsize
676 #define TCBHASHSIZE 0
681 * Callouts should be moved into struct tcp directly. They are currently
682 * separate because the tcpcb structure is exported to userland for sysctl
683 * parsing purposes, which do not know about callouts.
694 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone);
695 #define V_tcpcb_zone VNET(tcpcb_zone)
697 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
698 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory");
700 static struct mtx isn_mtx;
702 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
703 #define ISN_LOCK() mtx_lock(&isn_mtx)
704 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
707 * TCP initialization.
710 tcp_zone_change(void *tag)
713 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
714 uma_zone_set_max(V_tcpcb_zone, maxsockets);
715 tcp_tw_zone_change();
719 tcp_inpcb_init(void *mem, int size, int flags)
721 struct inpcb *inp = mem;
723 INP_LOCK_INIT(inp, "inp", "tcpinp");
728 * Take a value and get the next power of 2 that doesn't overflow.
729 * Used to size the tcp_inpcb hash buckets.
732 maketcp_hashsize(int size)
738 * get the next power of 2 higher than maxsockets.
740 hashsize = 1 << fls(size);
741 /* catch overflow, and just go one power of 2 smaller */
742 if (hashsize < size) {
743 hashsize = 1 << (fls(size) - 1);
748 static volatile int next_tcp_stack_id = 1;
751 * Register a TCP function block with the name provided in the names
752 * array. (Note that this function does NOT automatically register
753 * blk->tfb_tcp_block_name as a stack name. Therefore, you should
754 * explicitly include blk->tfb_tcp_block_name in the list of names if
755 * you wish to register the stack with that name.)
757 * Either all name registrations will succeed or all will fail. If
758 * a name registration fails, the function will update the num_names
759 * argument to point to the array index of the name that encountered
762 * Returns 0 on success, or an error code on failure.
765 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait,
766 const char *names[], int *num_names)
768 struct tcp_function *n;
769 struct tcp_function_set fs;
772 KASSERT(names != NULL && *num_names > 0,
773 ("%s: Called with 0-length name list", __func__));
774 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__));
775 KASSERT(rw_initialized(&tcp_function_lock),
776 ("%s: called too early", __func__));
778 if ((blk->tfb_tcp_output == NULL) ||
779 (blk->tfb_tcp_do_segment == NULL) ||
780 (blk->tfb_tcp_ctloutput == NULL) ||
781 (strlen(blk->tfb_tcp_block_name) == 0)) {
783 * These functions are required and you
789 if (blk->tfb_tcp_timer_stop_all ||
790 blk->tfb_tcp_timer_activate ||
791 blk->tfb_tcp_timer_active ||
792 blk->tfb_tcp_timer_stop) {
794 * If you define one timer function you
795 * must have them all.
797 if ((blk->tfb_tcp_timer_stop_all == NULL) ||
798 (blk->tfb_tcp_timer_activate == NULL) ||
799 (blk->tfb_tcp_timer_active == NULL) ||
800 (blk->tfb_tcp_timer_stop == NULL)) {
806 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
811 refcount_init(&blk->tfb_refcnt, 0);
812 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1);
813 for (i = 0; i < *num_names; i++) {
814 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait);
821 (void)strlcpy(fs.function_set_name, names[i],
822 sizeof(fs.function_set_name));
823 rw_wlock(&tcp_function_lock);
824 if (find_tcp_functions_locked(&fs) != NULL) {
825 /* Duplicate name space not allowed */
826 rw_wunlock(&tcp_function_lock);
827 free(n, M_TCPFUNCTIONS);
831 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name));
832 TAILQ_INSERT_TAIL(&t_functions, n, tf_next);
834 rw_wunlock(&tcp_function_lock);
840 * Deregister the names we just added. Because registration failed
841 * for names[i], we don't need to deregister that name.
844 rw_wlock(&tcp_function_lock);
846 TAILQ_FOREACH(n, &t_functions, tf_next) {
847 if (!strncmp(n->tf_name, names[i],
848 TCP_FUNCTION_NAME_LEN_MAX)) {
849 TAILQ_REMOVE(&t_functions, n, tf_next);
852 free(n, M_TCPFUNCTIONS);
857 rw_wunlock(&tcp_function_lock);
862 * Register a TCP function block using the name provided in the name
865 * Returns 0 on success, or an error code on failure.
868 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name,
871 const char *name_list[1];
878 name_list[0] = blk->tfb_tcp_block_name;
879 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names);
884 * Register a TCP function block using the name defined in
885 * blk->tfb_tcp_block_name.
887 * Returns 0 on success, or an error code on failure.
890 register_tcp_functions(struct tcp_function_block *blk, int wait)
893 return (register_tcp_functions_as_name(blk, NULL, wait));
897 * Deregister all names associated with a function block. This
898 * functionally removes the function block from use within the system.
900 * When called with a true quiesce argument, mark the function block
901 * as being removed so no more stacks will use it and determine
902 * whether the removal would succeed.
904 * When called with a false quiesce argument, actually attempt the
907 * When called with a force argument, attempt to switch all TCBs to
908 * use the default stack instead of returning EBUSY.
910 * Returns 0 on success (or if the removal would succeed, or an error
914 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce,
917 struct tcp_function *f;
919 if (blk == &tcp_def_funcblk) {
920 /* You can't un-register the default */
923 rw_wlock(&tcp_function_lock);
924 if (blk == tcp_func_set_ptr) {
925 /* You can't free the current default */
926 rw_wunlock(&tcp_function_lock);
929 /* Mark the block so no more stacks can use it. */
930 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED;
932 * If TCBs are still attached to the stack, attempt to switch them
933 * to the default stack.
935 if (force && blk->tfb_refcnt) {
938 VNET_ITERATOR_DECL(vnet_iter);
940 rw_wunlock(&tcp_function_lock);
943 VNET_FOREACH(vnet_iter) {
944 CURVNET_SET(vnet_iter);
945 INP_INFO_WLOCK(&V_tcbinfo);
946 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) {
948 if (inp->inp_flags & INP_TIMEWAIT) {
953 if (tp == NULL || tp->t_fb != blk) {
957 tcp_switch_back_to_default(tp);
960 INP_INFO_WUNLOCK(&V_tcbinfo);
965 rw_wlock(&tcp_function_lock);
967 if (blk->tfb_refcnt) {
968 /* TCBs still attached. */
969 rw_wunlock(&tcp_function_lock);
974 rw_wunlock(&tcp_function_lock);
977 /* Remove any function names that map to this function block. */
978 while (find_tcp_fb_locked(blk, &f) != NULL) {
979 TAILQ_REMOVE(&t_functions, f, tf_next);
982 free(f, M_TCPFUNCTIONS);
984 rw_wunlock(&tcp_function_lock);
991 const char *tcbhash_tuneable;
994 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
997 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
998 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
999 printf("%s: WARNING: unable to register helper hook\n", __func__);
1000 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
1001 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
1002 printf("%s: WARNING: unable to register helper hook\n", __func__);
1004 hashsize = TCBHASHSIZE;
1005 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
1006 if (hashsize == 0) {
1008 * Auto tune the hash size based on maxsockets.
1009 * A perfect hash would have a 1:1 mapping
1010 * (hashsize = maxsockets) however it's been
1011 * suggested that O(2) average is better.
1013 hashsize = maketcp_hashsize(maxsockets / 4);
1015 * Our historical default is 512,
1016 * do not autotune lower than this.
1020 if (bootverbose && IS_DEFAULT_VNET(curvnet))
1021 printf("%s: %s auto tuned to %d\n", __func__,
1022 tcbhash_tuneable, hashsize);
1025 * We require a hashsize to be a power of two.
1026 * Previously if it was not a power of two we would just reset it
1027 * back to 512, which could be a nasty surprise if you did not notice
1028 * the error message.
1029 * Instead what we do is clip it to the closest power of two lower
1030 * than the specified hash value.
1032 if (!powerof2(hashsize)) {
1033 int oldhashsize = hashsize;
1035 hashsize = maketcp_hashsize(hashsize);
1036 /* prevent absurdly low value */
1039 printf("%s: WARNING: TCB hash size not a power of 2, "
1040 "clipped from %d to %d.\n", __func__, oldhashsize,
1043 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
1044 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE);
1047 * These have to be type stable for the benefit of the timers.
1049 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
1050 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1051 uma_zone_set_max(V_tcpcb_zone, maxsockets);
1052 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
1058 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
1059 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
1060 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1062 tcp_fastopen_init();
1064 /* Skip initialization of globals for non-default instances. */
1065 if (!IS_DEFAULT_VNET(curvnet))
1068 tcp_reass_global_init();
1070 /* XXX virtualize those bellow? */
1071 tcp_delacktime = TCPTV_DELACK;
1072 tcp_keepinit = TCPTV_KEEP_INIT;
1073 tcp_keepidle = TCPTV_KEEP_IDLE;
1074 tcp_keepintvl = TCPTV_KEEPINTVL;
1075 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
1076 tcp_msl = TCPTV_MSL;
1077 tcp_rexmit_initial = TCPTV_RTOBASE;
1078 if (tcp_rexmit_initial < 1)
1079 tcp_rexmit_initial = 1;
1080 tcp_rexmit_min = TCPTV_MIN;
1081 if (tcp_rexmit_min < 1)
1083 tcp_persmin = TCPTV_PERSMIN;
1084 tcp_persmax = TCPTV_PERSMAX;
1085 tcp_rexmit_slop = TCPTV_CPU_VAR;
1086 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
1087 tcp_tcbhashsize = hashsize;
1089 /* Setup the tcp function block list */
1090 TAILQ_INIT(&t_functions);
1091 rw_init(&tcp_function_lock, "tcp_func_lock");
1092 register_tcp_functions(&tcp_def_funcblk, M_WAITOK);
1094 /* Initialize the TCP logging data. */
1097 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0);
1099 if (tcp_soreceive_stream) {
1101 tcp_usrreqs.pru_soreceive = soreceive_stream;
1104 tcp6_usrreqs.pru_soreceive = soreceive_stream;
1109 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
1111 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
1113 if (max_protohdr < TCP_MINPROTOHDR)
1114 max_protohdr = TCP_MINPROTOHDR;
1115 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
1117 #undef TCP_MINPROTOHDR
1120 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
1121 SHUTDOWN_PRI_DEFAULT);
1122 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
1123 EVENTHANDLER_PRI_ANY);
1131 tcp_destroy(void *unused __unused)
1139 * All our processes are gone, all our sockets should be cleaned
1140 * up, which means, we should be past the tcp_discardcb() calls.
1141 * Sleep to let all tcpcb timers really disappear and cleanup.
1144 INP_LIST_RLOCK(&V_tcbinfo);
1145 n = V_tcbinfo.ipi_count;
1146 INP_LIST_RUNLOCK(&V_tcbinfo);
1149 pause("tcpdes", hz / 10);
1154 in_pcbinfo_destroy(&V_tcbinfo);
1155 /* tcp_discardcb() clears the sack_holes up. */
1156 uma_zdestroy(V_sack_hole_zone);
1157 uma_zdestroy(V_tcpcb_zone);
1160 * Cannot free the zone until all tcpcbs are released as we attach
1161 * the allocations to them.
1163 tcp_fastopen_destroy();
1166 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
1168 printf("%s: WARNING: unable to deregister helper hook "
1169 "type=%d, id=%d: error %d returned\n", __func__,
1170 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
1172 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
1174 printf("%s: WARNING: unable to deregister helper hook "
1175 "type=%d, id=%d: error %d returned\n", __func__,
1176 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
1180 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL);
1190 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
1191 * tcp_template used to store this data in mbufs, but we now recopy it out
1192 * of the tcpcb each time to conserve mbufs.
1195 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
1197 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
1199 INP_WLOCK_ASSERT(inp);
1202 if ((inp->inp_vflag & INP_IPV6) != 0) {
1203 struct ip6_hdr *ip6;
1205 ip6 = (struct ip6_hdr *)ip_ptr;
1206 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
1207 (inp->inp_flow & IPV6_FLOWINFO_MASK);
1208 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
1209 (IPV6_VERSION & IPV6_VERSION_MASK);
1210 ip6->ip6_nxt = IPPROTO_TCP;
1211 ip6->ip6_plen = htons(sizeof(struct tcphdr));
1212 ip6->ip6_src = inp->in6p_laddr;
1213 ip6->ip6_dst = inp->in6p_faddr;
1216 #if defined(INET6) && defined(INET)
1223 ip = (struct ip *)ip_ptr;
1224 ip->ip_v = IPVERSION;
1226 ip->ip_tos = inp->inp_ip_tos;
1230 ip->ip_ttl = inp->inp_ip_ttl;
1232 ip->ip_p = IPPROTO_TCP;
1233 ip->ip_src = inp->inp_laddr;
1234 ip->ip_dst = inp->inp_faddr;
1237 th->th_sport = inp->inp_lport;
1238 th->th_dport = inp->inp_fport;
1246 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
1250 * Create template to be used to send tcp packets on a connection.
1251 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
1252 * use for this function is in keepalives, which use tcp_respond.
1255 tcpip_maketemplate(struct inpcb *inp)
1259 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
1262 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
1267 * Send a single message to the TCP at address specified by
1268 * the given TCP/IP header. If m == NULL, then we make a copy
1269 * of the tcpiphdr at th and send directly to the addressed host.
1270 * This is used to force keep alive messages out using the TCP
1271 * template for a connection. If flags are given then we send
1272 * a message back to the TCP which originated the segment th,
1273 * and discard the mbuf containing it and any other attached mbufs.
1275 * In any case the ack and sequence number of the transmitted
1276 * segment are as specified by the parameters.
1278 * NOTE: If m != NULL, then th must point to *inside* the mbuf.
1281 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
1282 tcp_seq ack, tcp_seq seq, int flags)
1291 struct ip6_hdr *ip6;
1294 int optlen, tlen, win;
1297 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
1300 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
1307 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
1308 INP_WLOCK_ASSERT(inp);
1315 if (!(flags & TH_RST)) {
1316 win = sbspace(&inp->inp_socket->so_rcv);
1317 if (win > TCP_MAXWIN << tp->rcv_scale)
1318 win = TCP_MAXWIN << tp->rcv_scale;
1320 if ((tp->t_flags & TF_NOOPT) == 0)
1324 m = m_gethdr(M_NOWAIT, MT_DATA);
1327 m->m_data += max_linkhdr;
1330 bcopy((caddr_t)ip6, mtod(m, caddr_t),
1331 sizeof(struct ip6_hdr));
1332 ip6 = mtod(m, struct ip6_hdr *);
1333 nth = (struct tcphdr *)(ip6 + 1);
1337 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
1338 ip = mtod(m, struct ip *);
1339 nth = (struct tcphdr *)(ip + 1);
1341 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1343 } else if (!M_WRITABLE(m)) {
1346 /* Can't reuse 'm', allocate a new mbuf. */
1347 n = m_gethdr(M_NOWAIT, MT_DATA);
1353 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
1359 n->m_data += max_linkhdr;
1360 /* m_len is set later */
1361 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
1364 bcopy((caddr_t)ip6, mtod(n, caddr_t),
1365 sizeof(struct ip6_hdr));
1366 ip6 = mtod(n, struct ip6_hdr *);
1367 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1368 nth = (struct tcphdr *)(ip6 + 1);
1372 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip));
1373 ip = mtod(n, struct ip *);
1374 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1375 nth = (struct tcphdr *)(ip + 1);
1377 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1378 xchg(nth->th_dport, nth->th_sport, uint16_t);
1385 * XXX MRT We inherit the FIB, which is lucky.
1389 m->m_data = (caddr_t)ipgen;
1390 /* m_len is set later */
1393 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1394 nth = (struct tcphdr *)(ip6 + 1);
1398 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1399 nth = (struct tcphdr *)(ip + 1);
1403 * this is usually a case when an extension header
1404 * exists between the IPv6 header and the
1407 nth->th_sport = th->th_sport;
1408 nth->th_dport = th->th_dport;
1410 xchg(nth->th_dport, nth->th_sport, uint16_t);
1416 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
1418 #if defined(INET) && defined(INET6)
1422 tlen = sizeof (struct tcpiphdr);
1426 KASSERT(M_TRAILINGSPACE(m) >= tlen,
1427 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)",
1428 m, tlen, (long)M_TRAILINGSPACE(m)));
1433 /* Make sure we have room. */
1434 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) {
1435 m->m_next = m_get(M_NOWAIT, MT_DATA);
1437 optp = mtod(m->m_next, u_char *);
1442 optp = (u_char *) (nth + 1);
1448 if (tp->t_flags & TF_RCVD_TSTMP) {
1449 to.to_tsval = tcp_ts_getticks() + tp->ts_offset;
1450 to.to_tsecr = tp->ts_recent;
1451 to.to_flags |= TOF_TS;
1453 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1454 /* TCP-MD5 (RFC2385). */
1455 if (tp->t_flags & TF_SIGNATURE)
1456 to.to_flags |= TOF_SIGNATURE;
1458 /* Add the options. */
1459 tlen += optlen = tcp_addoptions(&to, optp);
1461 /* Update m_len in the correct mbuf. */
1462 optm->m_len += optlen;
1468 ip6->ip6_vfc = IPV6_VERSION;
1469 ip6->ip6_nxt = IPPROTO_TCP;
1470 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
1473 #if defined(INET) && defined(INET6)
1478 ip->ip_len = htons(tlen);
1479 ip->ip_ttl = V_ip_defttl;
1480 if (V_path_mtu_discovery)
1481 ip->ip_off |= htons(IP_DF);
1484 m->m_pkthdr.len = tlen;
1485 m->m_pkthdr.rcvif = NULL;
1489 * Packet is associated with a socket, so allow the
1490 * label of the response to reflect the socket label.
1492 INP_WLOCK_ASSERT(inp);
1493 mac_inpcb_create_mbuf(inp, m);
1496 * Packet is not associated with a socket, so possibly
1497 * update the label in place.
1499 mac_netinet_tcp_reply(m);
1502 nth->th_seq = htonl(seq);
1503 nth->th_ack = htonl(ack);
1505 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
1506 nth->th_flags = flags;
1508 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
1510 nth->th_win = htons((u_short)win);
1513 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1514 if (to.to_flags & TOF_SIGNATURE) {
1515 if (!TCPMD5_ENABLED() ||
1516 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) {
1523 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
1526 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
1527 nth->th_sum = in6_cksum_pseudo(ip6,
1528 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
1529 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
1533 #if defined(INET6) && defined(INET)
1538 m->m_pkthdr.csum_flags = CSUM_TCP;
1539 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
1540 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
1544 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
1545 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
1547 TCP_PROBE3(debug__output, tp, th, m);
1549 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth);
1553 TCP_PROBE5(send, NULL, tp, ip6, tp, nth);
1554 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp);
1557 #if defined(INET) && defined(INET6)
1562 TCP_PROBE5(send, NULL, tp, ip, tp, nth);
1563 (void)ip_output(m, NULL, NULL, 0, NULL, inp);
1569 * Create a new TCP control block, making an
1570 * empty reassembly queue and hooking it to the argument
1571 * protocol control block. The `inp' parameter must have
1572 * come from the zone allocator set up in tcp_init().
1575 tcp_newtcpcb(struct inpcb *inp)
1577 struct tcpcb_mem *tm;
1580 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
1583 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
1588 /* Initialise cc_var struct for this tcpcb. */
1590 tp->ccv->type = IPPROTO_TCP;
1591 tp->ccv->ccvc.tcp = tp;
1592 rw_rlock(&tcp_function_lock);
1593 tp->t_fb = tcp_func_set_ptr;
1594 refcount_acquire(&tp->t_fb->tfb_refcnt);
1595 rw_runlock(&tcp_function_lock);
1597 * Use the current system default CC algorithm.
1600 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
1601 CC_ALGO(tp) = CC_DEFAULT();
1604 if (CC_ALGO(tp)->cb_init != NULL)
1605 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
1606 if (tp->t_fb->tfb_tcp_fb_fini)
1607 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1608 refcount_release(&tp->t_fb->tfb_refcnt);
1609 uma_zfree(V_tcpcb_zone, tm);
1615 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
1616 if (tp->t_fb->tfb_tcp_fb_fini)
1617 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1618 refcount_release(&tp->t_fb->tfb_refcnt);
1619 uma_zfree(V_tcpcb_zone, tm);
1625 tp->t_vnet = inp->inp_vnet;
1627 tp->t_timers = &tm->tt;
1628 TAILQ_INIT(&tp->t_segq);
1631 isipv6 ? V_tcp_v6mssdflt :
1635 /* Set up our timeouts. */
1636 callout_init(&tp->t_timers->tt_rexmt, 1);
1637 callout_init(&tp->t_timers->tt_persist, 1);
1638 callout_init(&tp->t_timers->tt_keep, 1);
1639 callout_init(&tp->t_timers->tt_2msl, 1);
1640 callout_init(&tp->t_timers->tt_delack, 1);
1642 if (V_tcp_do_rfc1323)
1643 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
1645 tp->t_flags |= TF_SACK_PERMIT;
1646 TAILQ_INIT(&tp->snd_holes);
1648 * The tcpcb will hold a reference on its inpcb until tcp_discardcb()
1651 in_pcbref(inp); /* Reference for tcpcb */
1655 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
1656 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
1657 * reasonable initial retransmit time.
1659 tp->t_srtt = TCPTV_SRTTBASE;
1660 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
1661 tp->t_rttmin = tcp_rexmit_min;
1662 tp->t_rxtcur = tcp_rexmit_initial;
1663 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1664 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1665 tp->t_rcvtime = ticks;
1667 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1668 * because the socket may be bound to an IPv6 wildcard address,
1669 * which may match an IPv4-mapped IPv6 address.
1671 inp->inp_ip_ttl = V_ip_defttl;
1675 * Init the TCP PCAP queues.
1677 tcp_pcap_tcpcb_init(tp);
1680 /* Initialize the per-TCPCB log data. */
1681 tcp_log_tcpcbinit(tp);
1683 if (tp->t_fb->tfb_tcp_fb_init) {
1684 (*tp->t_fb->tfb_tcp_fb_init)(tp);
1686 return (tp); /* XXX */
1690 * Switch the congestion control algorithm back to NewReno for any active
1691 * control blocks using an algorithm which is about to go away.
1692 * This ensures the CC framework can allow the unload to proceed without leaving
1693 * any dangling pointers which would trigger a panic.
1694 * Returning non-zero would inform the CC framework that something went wrong
1695 * and it would be unsafe to allow the unload to proceed. However, there is no
1696 * way for this to occur with this implementation so we always return zero.
1699 tcp_ccalgounload(struct cc_algo *unload_algo)
1701 struct cc_algo *tmpalgo;
1704 VNET_ITERATOR_DECL(vnet_iter);
1707 * Check all active control blocks across all network stacks and change
1708 * any that are using "unload_algo" back to NewReno. If "unload_algo"
1709 * requires cleanup code to be run, call it.
1712 VNET_FOREACH(vnet_iter) {
1713 CURVNET_SET(vnet_iter);
1714 INP_INFO_WLOCK(&V_tcbinfo);
1716 * New connections already part way through being initialised
1717 * with the CC algo we're removing will not race with this code
1718 * because the INP_INFO_WLOCK is held during initialisation. We
1719 * therefore don't enter the loop below until the connection
1720 * list has stabilised.
1722 CK_LIST_FOREACH(inp, &V_tcb, inp_list) {
1724 /* Important to skip tcptw structs. */
1725 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1726 (tp = intotcpcb(inp)) != NULL) {
1728 * By holding INP_WLOCK here, we are assured
1729 * that the connection is not currently
1730 * executing inside the CC module's functions
1731 * i.e. it is safe to make the switch back to
1734 if (CC_ALGO(tp) == unload_algo) {
1735 tmpalgo = CC_ALGO(tp);
1736 if (tmpalgo->cb_destroy != NULL)
1737 tmpalgo->cb_destroy(tp->ccv);
1740 * NewReno may allocate memory on
1741 * demand for certain stateful
1742 * configuration as needed, but is
1743 * coded to never fail on memory
1744 * allocation failure so it is a safe
1747 CC_ALGO(tp) = &newreno_cc_algo;
1752 INP_INFO_WUNLOCK(&V_tcbinfo);
1755 VNET_LIST_RUNLOCK();
1761 * Drop a TCP connection, reporting
1762 * the specified error. If connection is synchronized,
1763 * then send a RST to peer.
1766 tcp_drop(struct tcpcb *tp, int errno)
1768 struct socket *so = tp->t_inpcb->inp_socket;
1770 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1771 INP_WLOCK_ASSERT(tp->t_inpcb);
1773 if (TCPS_HAVERCVDSYN(tp->t_state)) {
1774 tcp_state_change(tp, TCPS_CLOSED);
1775 (void) tp->t_fb->tfb_tcp_output(tp);
1776 TCPSTAT_INC(tcps_drops);
1778 TCPSTAT_INC(tcps_conndrops);
1779 if (errno == ETIMEDOUT && tp->t_softerror)
1780 errno = tp->t_softerror;
1781 so->so_error = errno;
1782 return (tcp_close(tp));
1786 tcp_discardcb(struct tcpcb *tp)
1788 struct inpcb *inp = tp->t_inpcb;
1789 struct socket *so = inp->inp_socket;
1791 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
1793 int released __unused;
1795 INP_WLOCK_ASSERT(inp);
1798 * Make sure that all of our timers are stopped before we delete the
1801 * If stopping a timer fails, we schedule a discard function in same
1802 * callout, and the last discard function called will take care of
1803 * deleting the tcpcb.
1805 tp->t_timers->tt_draincnt = 0;
1806 tcp_timer_stop(tp, TT_REXMT);
1807 tcp_timer_stop(tp, TT_PERSIST);
1808 tcp_timer_stop(tp, TT_KEEP);
1809 tcp_timer_stop(tp, TT_2MSL);
1810 tcp_timer_stop(tp, TT_DELACK);
1811 if (tp->t_fb->tfb_tcp_timer_stop_all) {
1813 * Call the stop-all function of the methods,
1814 * this function should call the tcp_timer_stop()
1815 * method with each of the function specific timeouts.
1816 * That stop will be called via the tfb_tcp_timer_stop()
1817 * which should use the async drain function of the
1818 * callout system (see tcp_var.h).
1820 tp->t_fb->tfb_tcp_timer_stop_all(tp);
1824 * If we got enough samples through the srtt filter,
1825 * save the rtt and rttvar in the routing entry.
1826 * 'Enough' is arbitrarily defined as 4 rtt samples.
1827 * 4 samples is enough for the srtt filter to converge
1828 * to within enough % of the correct value; fewer samples
1829 * and we could save a bogus rtt. The danger is not high
1830 * as tcp quickly recovers from everything.
1831 * XXX: Works very well but needs some more statistics!
1833 if (tp->t_rttupdated >= 4) {
1834 struct hc_metrics_lite metrics;
1837 bzero(&metrics, sizeof(metrics));
1839 * Update the ssthresh always when the conditions below
1840 * are satisfied. This gives us better new start value
1841 * for the congestion avoidance for new connections.
1842 * ssthresh is only set if packet loss occurred on a session.
1844 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
1845 * being torn down. Ideally this code would not use 'so'.
1847 ssthresh = tp->snd_ssthresh;
1848 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
1850 * convert the limit from user data bytes to
1851 * packets then to packet data bytes.
1853 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
1856 ssthresh *= (tp->t_maxseg +
1858 (isipv6 ? sizeof (struct ip6_hdr) +
1859 sizeof (struct tcphdr) :
1861 sizeof (struct tcpiphdr)
1868 metrics.rmx_ssthresh = ssthresh;
1870 metrics.rmx_rtt = tp->t_srtt;
1871 metrics.rmx_rttvar = tp->t_rttvar;
1872 metrics.rmx_cwnd = tp->snd_cwnd;
1873 metrics.rmx_sendpipe = 0;
1874 metrics.rmx_recvpipe = 0;
1876 tcp_hc_update(&inp->inp_inc, &metrics);
1879 /* free the reassembly queue, if any */
1880 tcp_reass_flush(tp);
1883 /* Disconnect offload device, if any. */
1884 if (tp->t_flags & TF_TOE)
1885 tcp_offload_detach(tp);
1888 tcp_free_sackholes(tp);
1891 /* Free the TCP PCAP queues. */
1892 tcp_pcap_drain(&(tp->t_inpkts));
1893 tcp_pcap_drain(&(tp->t_outpkts));
1896 /* Allow the CC algorithm to clean up after itself. */
1897 if (CC_ALGO(tp)->cb_destroy != NULL)
1898 CC_ALGO(tp)->cb_destroy(tp->ccv);
1902 khelp_destroy_osd(tp->osd);
1906 inp->inp_ppcb = NULL;
1907 if (tp->t_timers->tt_draincnt == 0) {
1908 /* We own the last reference on tcpcb, let's free it. */
1910 tcp_log_tcpcbfini(tp);
1912 TCPSTATES_DEC(tp->t_state);
1913 if (tp->t_fb->tfb_tcp_fb_fini)
1914 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1915 refcount_release(&tp->t_fb->tfb_refcnt);
1917 uma_zfree(V_tcpcb_zone, tp);
1918 released = in_pcbrele_wlocked(inp);
1919 KASSERT(!released, ("%s: inp %p should not have been released "
1920 "here", __func__, inp));
1925 tcp_timer_discard(void *ptp)
1929 struct epoch_tracker et;
1931 tp = (struct tcpcb *)ptp;
1932 CURVNET_SET(tp->t_vnet);
1933 INP_INFO_RLOCK_ET(&V_tcbinfo, et);
1935 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL",
1938 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0,
1939 ("%s: tcpcb has to be stopped here", __func__));
1940 tp->t_timers->tt_draincnt--;
1941 if (tp->t_timers->tt_draincnt == 0) {
1942 /* We own the last reference on this tcpcb, let's free it. */
1944 tcp_log_tcpcbfini(tp);
1946 TCPSTATES_DEC(tp->t_state);
1947 if (tp->t_fb->tfb_tcp_fb_fini)
1948 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
1949 refcount_release(&tp->t_fb->tfb_refcnt);
1951 uma_zfree(V_tcpcb_zone, tp);
1952 if (in_pcbrele_wlocked(inp)) {
1953 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
1959 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
1964 * Attempt to close a TCP control block, marking it as dropped, and freeing
1965 * the socket if we hold the only reference.
1968 tcp_close(struct tcpcb *tp)
1970 struct inpcb *inp = tp->t_inpcb;
1973 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1974 INP_WLOCK_ASSERT(inp);
1977 if (tp->t_state == TCPS_LISTEN)
1978 tcp_offload_listen_stop(tp);
1981 * This releases the TFO pending counter resource for TFO listen
1982 * sockets as well as passively-created TFO sockets that transition
1983 * from SYN_RECEIVED to CLOSED.
1985 if (tp->t_tfo_pending) {
1986 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
1987 tp->t_tfo_pending = NULL;
1990 TCPSTAT_INC(tcps_closed);
1991 if (tp->t_state != TCPS_CLOSED)
1992 tcp_state_change(tp, TCPS_CLOSED);
1993 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1994 so = inp->inp_socket;
1995 soisdisconnected(so);
1996 if (inp->inp_flags & INP_SOCKREF) {
1997 KASSERT(so->so_state & SS_PROTOREF,
1998 ("tcp_close: !SS_PROTOREF"));
1999 inp->inp_flags &= ~INP_SOCKREF;
2002 so->so_state &= ~SS_PROTOREF;
2012 VNET_ITERATOR_DECL(vnet_iter);
2017 VNET_LIST_RLOCK_NOSLEEP();
2018 VNET_FOREACH(vnet_iter) {
2019 CURVNET_SET(vnet_iter);
2024 * Walk the tcpbs, if existing, and flush the reassembly queue,
2025 * if there is one...
2026 * XXX: The "Net/3" implementation doesn't imply that the TCP
2027 * reassembly queue should be flushed, but in a situation
2028 * where we're really low on mbufs, this is potentially
2031 INP_INFO_WLOCK(&V_tcbinfo);
2032 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
2034 if (inpb->inp_flags & INP_TIMEWAIT) {
2038 if ((tcpb = intotcpcb(inpb)) != NULL) {
2039 tcp_reass_flush(tcpb);
2040 tcp_clean_sackreport(tcpb);
2042 tcp_log_drain(tcpb);
2045 if (tcp_pcap_aggressive_free) {
2046 /* Free the TCP PCAP queues. */
2047 tcp_pcap_drain(&(tcpb->t_inpkts));
2048 tcp_pcap_drain(&(tcpb->t_outpkts));
2054 INP_INFO_WUNLOCK(&V_tcbinfo);
2057 VNET_LIST_RUNLOCK_NOSLEEP();
2061 * Notify a tcp user of an asynchronous error;
2062 * store error as soft error, but wake up user
2063 * (for now, won't do anything until can select for soft error).
2065 * Do not wake up user since there currently is no mechanism for
2066 * reporting soft errors (yet - a kqueue filter may be added).
2068 static struct inpcb *
2069 tcp_notify(struct inpcb *inp, int error)
2073 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
2074 INP_WLOCK_ASSERT(inp);
2076 if ((inp->inp_flags & INP_TIMEWAIT) ||
2077 (inp->inp_flags & INP_DROPPED))
2080 tp = intotcpcb(inp);
2081 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
2084 * Ignore some errors if we are hooked up.
2085 * If connection hasn't completed, has retransmitted several times,
2086 * and receives a second error, give up now. This is better
2087 * than waiting a long time to establish a connection that
2088 * can never complete.
2090 if (tp->t_state == TCPS_ESTABLISHED &&
2091 (error == EHOSTUNREACH || error == ENETUNREACH ||
2092 error == EHOSTDOWN)) {
2093 if (inp->inp_route.ro_rt) {
2094 RTFREE(inp->inp_route.ro_rt);
2095 inp->inp_route.ro_rt = (struct rtentry *)NULL;
2098 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
2100 tp = tcp_drop(tp, error);
2106 tp->t_softerror = error;
2110 wakeup( &so->so_timeo);
2117 tcp_pcblist(SYSCTL_HANDLER_ARGS)
2119 int error, i, m, n, pcb_count;
2120 struct inpcb *inp, **inp_list;
2123 struct epoch_tracker et;
2126 * The process of preparing the TCB list is too time-consuming and
2127 * resource-intensive to repeat twice on every request.
2129 if (req->oldptr == NULL) {
2130 n = V_tcbinfo.ipi_count +
2131 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2132 n += imax(n / 8, 10);
2133 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
2137 if (req->newptr != NULL)
2141 * OK, now we're committed to doing something.
2143 INP_LIST_RLOCK(&V_tcbinfo);
2144 gencnt = V_tcbinfo.ipi_gencnt;
2145 n = V_tcbinfo.ipi_count;
2146 INP_LIST_RUNLOCK(&V_tcbinfo);
2148 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2150 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
2151 + (n + m) * sizeof(struct xtcpcb));
2155 bzero(&xig, sizeof(xig));
2156 xig.xig_len = sizeof xig;
2157 xig.xig_count = n + m;
2158 xig.xig_gen = gencnt;
2159 xig.xig_sogen = so_gencnt;
2160 error = SYSCTL_OUT(req, &xig, sizeof xig);
2164 error = syncache_pcblist(req, m, &pcb_count);
2168 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
2170 INP_INFO_WLOCK(&V_tcbinfo);
2171 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
2172 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) {
2174 if (inp->inp_gencnt <= gencnt) {
2176 * XXX: This use of cr_cansee(), introduced with
2177 * TCP state changes, is not quite right, but for
2178 * now, better than nothing.
2180 if (inp->inp_flags & INP_TIMEWAIT) {
2181 if (intotw(inp) != NULL)
2182 error = cr_cansee(req->td->td_ucred,
2183 intotw(inp)->tw_cred);
2185 error = EINVAL; /* Skip this inp. */
2187 error = cr_canseeinpcb(req->td->td_ucred, inp);
2190 inp_list[i++] = inp;
2195 INP_INFO_WUNLOCK(&V_tcbinfo);
2199 for (i = 0; i < n; i++) {
2202 if (inp->inp_gencnt <= gencnt) {
2205 tcp_inptoxtp(inp, &xt);
2207 error = SYSCTL_OUT(req, &xt, sizeof xt);
2211 INP_INFO_RLOCK_ET(&V_tcbinfo, et);
2212 for (i = 0; i < n; i++) {
2215 if (!in_pcbrele_rlocked(inp))
2218 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
2222 * Give the user an updated idea of our state.
2223 * If the generation differs from what we told
2224 * her before, she knows that something happened
2225 * while we were processing this request, and it
2226 * might be necessary to retry.
2228 INP_LIST_RLOCK(&V_tcbinfo);
2229 xig.xig_gen = V_tcbinfo.ipi_gencnt;
2230 xig.xig_sogen = so_gencnt;
2231 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
2232 INP_LIST_RUNLOCK(&V_tcbinfo);
2233 error = SYSCTL_OUT(req, &xig, sizeof xig);
2235 free(inp_list, M_TEMP);
2239 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
2240 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
2241 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
2245 tcp_getcred(SYSCTL_HANDLER_ARGS)
2248 struct sockaddr_in addrs[2];
2252 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2255 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2258 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
2259 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
2261 if (inp->inp_socket == NULL)
2264 error = cr_canseeinpcb(req->td->td_ucred, inp);
2266 cru2x(inp->inp_cred, &xuc);
2271 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2275 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
2276 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
2277 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
2282 tcp6_getcred(SYSCTL_HANDLER_ARGS)
2285 struct sockaddr_in6 addrs[2];
2292 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2295 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2298 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
2299 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
2302 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
2304 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
2313 inp = in_pcblookup(&V_tcbinfo,
2314 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
2316 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
2317 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
2320 inp = in6_pcblookup(&V_tcbinfo,
2321 &addrs[1].sin6_addr, addrs[1].sin6_port,
2322 &addrs[0].sin6_addr, addrs[0].sin6_port,
2323 INPLOOKUP_RLOCKPCB, NULL);
2325 if (inp->inp_socket == NULL)
2328 error = cr_canseeinpcb(req->td->td_ucred, inp);
2330 cru2x(inp->inp_cred, &xuc);
2335 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2339 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
2340 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
2341 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
2347 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
2349 struct ip *ip = vip;
2351 struct in_addr faddr;
2354 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
2356 struct in_conninfo inc;
2357 struct epoch_tracker et;
2358 tcp_seq icmp_tcp_seq;
2361 faddr = ((struct sockaddr_in *)sa)->sin_addr;
2362 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
2365 if (cmd == PRC_MSGSIZE)
2366 notify = tcp_mtudisc_notify;
2367 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
2368 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL ||
2369 cmd == PRC_TIMXCEED_INTRANS) && ip)
2370 notify = tcp_drop_syn_sent;
2373 * Hostdead is ugly because it goes linearly through all PCBs.
2374 * XXX: We never get this from ICMP, otherwise it makes an
2375 * excellent DoS attack on machines with many connections.
2377 else if (cmd == PRC_HOSTDEAD)
2379 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
2383 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
2387 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip));
2388 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2));
2389 INP_INFO_RLOCK_ET(&V_tcbinfo, et);
2390 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src,
2391 th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
2392 if (inp != NULL && PRC_IS_REDIRECT(cmd)) {
2393 /* signal EHOSTDOWN, as it flushes the cached route */
2394 inp = (*notify)(inp, EHOSTDOWN);
2397 icmp_tcp_seq = th->th_seq;
2399 if (!(inp->inp_flags & INP_TIMEWAIT) &&
2400 !(inp->inp_flags & INP_DROPPED) &&
2401 !(inp->inp_socket == NULL)) {
2402 tp = intotcpcb(inp);
2403 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
2404 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
2405 if (cmd == PRC_MSGSIZE) {
2408 * If we got a needfrag set the MTU
2409 * in the route to the suggested new
2410 * value (if given) and then notify.
2412 mtu = ntohs(icp->icmp_nextmtu);
2414 * If no alternative MTU was
2415 * proposed, try the next smaller
2420 ntohs(ip->ip_len), 1);
2421 if (mtu < V_tcp_minmss +
2422 sizeof(struct tcpiphdr))
2423 mtu = V_tcp_minmss +
2424 sizeof(struct tcpiphdr);
2426 * Only process the offered MTU if it
2427 * is smaller than the current one.
2429 if (mtu < tp->t_maxseg +
2430 sizeof(struct tcpiphdr)) {
2431 bzero(&inc, sizeof(inc));
2432 inc.inc_faddr = faddr;
2434 inp->inp_inc.inc_fibnum;
2435 tcp_hc_updatemtu(&inc, mtu);
2436 tcp_mtudisc(inp, mtu);
2439 inp = (*notify)(inp,
2440 inetctlerrmap[cmd]);
2444 bzero(&inc, sizeof(inc));
2445 inc.inc_fport = th->th_dport;
2446 inc.inc_lport = th->th_sport;
2447 inc.inc_faddr = faddr;
2448 inc.inc_laddr = ip->ip_src;
2449 syncache_unreach(&inc, icmp_tcp_seq);
2454 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
2460 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
2462 struct in6_addr *dst;
2463 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
2464 struct ip6_hdr *ip6;
2468 struct icmp6_hdr *icmp6;
2469 struct ip6ctlparam *ip6cp = NULL;
2470 const struct sockaddr_in6 *sa6_src = NULL;
2471 struct in_conninfo inc;
2472 struct epoch_tracker et;
2477 tcp_seq icmp_tcp_seq;
2481 if (sa->sa_family != AF_INET6 ||
2482 sa->sa_len != sizeof(struct sockaddr_in6))
2485 /* if the parameter is from icmp6, decode it. */
2487 ip6cp = (struct ip6ctlparam *)d;
2488 icmp6 = ip6cp->ip6c_icmp6;
2490 ip6 = ip6cp->ip6c_ip6;
2491 off = ip6cp->ip6c_off;
2492 sa6_src = ip6cp->ip6c_src;
2493 dst = ip6cp->ip6c_finaldst;
2497 off = 0; /* fool gcc */
2502 if (cmd == PRC_MSGSIZE)
2503 notify = tcp_mtudisc_notify;
2504 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
2505 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL ||
2506 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL)
2507 notify = tcp_drop_syn_sent;
2510 * Hostdead is ugly because it goes linearly through all PCBs.
2511 * XXX: We never get this from ICMP, otherwise it makes an
2512 * excellent DoS attack on machines with many connections.
2514 else if (cmd == PRC_HOSTDEAD)
2516 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)
2520 in6_pcbnotify(&V_tcbinfo, sa, 0,
2521 (const struct sockaddr *)sa6_src,
2522 0, cmd, NULL, notify);
2526 /* Check if we can safely get the ports from the tcp hdr */
2529 (int32_t) (off + sizeof(struct tcp_ports)))) {
2532 bzero(&t_ports, sizeof(struct tcp_ports));
2533 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports);
2534 INP_INFO_RLOCK_ET(&V_tcbinfo, et);
2535 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport,
2536 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL);
2537 if (inp != NULL && PRC_IS_REDIRECT(cmd)) {
2538 /* signal EHOSTDOWN, as it flushes the cached route */
2539 inp = (*notify)(inp, EHOSTDOWN);
2542 off += sizeof(struct tcp_ports);
2543 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) {
2546 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq);
2548 if (!(inp->inp_flags & INP_TIMEWAIT) &&
2549 !(inp->inp_flags & INP_DROPPED) &&
2550 !(inp->inp_socket == NULL)) {
2551 tp = intotcpcb(inp);
2552 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
2553 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
2554 if (cmd == PRC_MSGSIZE) {
2557 * If we got a needfrag set the MTU
2558 * in the route to the suggested new
2559 * value (if given) and then notify.
2561 mtu = ntohl(icmp6->icmp6_mtu);
2563 * If no alternative MTU was
2564 * proposed, or the proposed
2565 * MTU was too small, set to
2568 if (mtu < IPV6_MMTU)
2569 mtu = IPV6_MMTU - 8;
2570 bzero(&inc, sizeof(inc));
2571 inc.inc_fibnum = M_GETFIB(m);
2572 inc.inc_flags |= INC_ISIPV6;
2573 inc.inc6_faddr = *dst;
2574 if (in6_setscope(&inc.inc6_faddr,
2575 m->m_pkthdr.rcvif, NULL))
2578 * Only process the offered MTU if it
2579 * is smaller than the current one.
2581 if (mtu < tp->t_maxseg +
2582 sizeof (struct tcphdr) +
2583 sizeof (struct ip6_hdr)) {
2584 tcp_hc_updatemtu(&inc, mtu);
2585 tcp_mtudisc(inp, mtu);
2586 ICMP6STAT_INC(icp6s_pmtuchg);
2589 inp = (*notify)(inp,
2590 inet6ctlerrmap[cmd]);
2594 bzero(&inc, sizeof(inc));
2595 inc.inc_fibnum = M_GETFIB(m);
2596 inc.inc_flags |= INC_ISIPV6;
2597 inc.inc_fport = t_ports.th_dport;
2598 inc.inc_lport = t_ports.th_sport;
2599 inc.inc6_faddr = *dst;
2600 inc.inc6_laddr = ip6->ip6_src;
2601 syncache_unreach(&inc, icmp_tcp_seq);
2606 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
2611 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len)
2617 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t));
2618 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t));
2619 switch (inc->inc_flags & INC_ISIPV6) {
2622 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr));
2623 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr));
2628 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr));
2629 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr));
2633 MD5Update(&ctx, key, len);
2634 MD5Final((unsigned char *)hash, &ctx);
2640 tcp_new_ts_offset(struct in_conninfo *inc)
2642 struct in_conninfo inc_store, *local_inc;
2644 if (!V_tcp_ts_offset_per_conn) {
2645 memcpy(&inc_store, inc, sizeof(struct in_conninfo));
2646 inc_store.inc_lport = 0;
2647 inc_store.inc_fport = 0;
2648 local_inc = &inc_store;
2652 return (tcp_keyed_hash(local_inc, V_ts_offset_secret,
2653 sizeof(V_ts_offset_secret)));
2657 * Following is where TCP initial sequence number generation occurs.
2659 * There are two places where we must use initial sequence numbers:
2660 * 1. In SYN-ACK packets.
2661 * 2. In SYN packets.
2663 * All ISNs for SYN-ACK packets are generated by the syncache. See
2664 * tcp_syncache.c for details.
2666 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
2667 * depends on this property. In addition, these ISNs should be
2668 * unguessable so as to prevent connection hijacking. To satisfy
2669 * the requirements of this situation, the algorithm outlined in
2670 * RFC 1948 is used, with only small modifications.
2672 * Implementation details:
2674 * Time is based off the system timer, and is corrected so that it
2675 * increases by one megabyte per second. This allows for proper
2676 * recycling on high speed LANs while still leaving over an hour
2679 * As reading the *exact* system time is too expensive to be done
2680 * whenever setting up a TCP connection, we increment the time
2681 * offset in two ways. First, a small random positive increment
2682 * is added to isn_offset for each connection that is set up.
2683 * Second, the function tcp_isn_tick fires once per clock tick
2684 * and increments isn_offset as necessary so that sequence numbers
2685 * are incremented at approximately ISN_BYTES_PER_SECOND. The
2686 * random positive increments serve only to ensure that the same
2687 * exact sequence number is never sent out twice (as could otherwise
2688 * happen when a port is recycled in less than the system tick
2691 * net.inet.tcp.isn_reseed_interval controls the number of seconds
2692 * between seeding of isn_secret. This is normally set to zero,
2693 * as reseeding should not be necessary.
2695 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
2696 * isn_offset_old, and isn_ctx is performed using the ISN lock. In
2697 * general, this means holding an exclusive (write) lock.
2700 #define ISN_BYTES_PER_SECOND 1048576
2701 #define ISN_STATIC_INCREMENT 4096
2702 #define ISN_RANDOM_INCREMENT (4096 - 1)
2703 #define ISN_SECRET_LENGTH 32
2705 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]);
2706 VNET_DEFINE_STATIC(int, isn_last);
2707 VNET_DEFINE_STATIC(int, isn_last_reseed);
2708 VNET_DEFINE_STATIC(u_int32_t, isn_offset);
2709 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old);
2711 #define V_isn_secret VNET(isn_secret)
2712 #define V_isn_last VNET(isn_last)
2713 #define V_isn_last_reseed VNET(isn_last_reseed)
2714 #define V_isn_offset VNET(isn_offset)
2715 #define V_isn_offset_old VNET(isn_offset_old)
2718 tcp_new_isn(struct in_conninfo *inc)
2721 u_int32_t projected_offset;
2724 /* Seed if this is the first use, reseed if requested. */
2725 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
2726 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
2728 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0);
2729 V_isn_last_reseed = ticks;
2732 /* Compute the md5 hash and return the ISN. */
2733 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret,
2734 sizeof(V_isn_secret));
2735 V_isn_offset += ISN_STATIC_INCREMENT +
2736 (arc4random() & ISN_RANDOM_INCREMENT);
2737 if (ticks != V_isn_last) {
2738 projected_offset = V_isn_offset_old +
2739 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
2740 if (SEQ_GT(projected_offset, V_isn_offset))
2741 V_isn_offset = projected_offset;
2742 V_isn_offset_old = V_isn_offset;
2745 new_isn += V_isn_offset;
2751 * When a specific ICMP unreachable message is received and the
2752 * connection state is SYN-SENT, drop the connection. This behavior
2753 * is controlled by the icmp_may_rst sysctl.
2756 tcp_drop_syn_sent(struct inpcb *inp, int errno)
2760 INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2761 INP_WLOCK_ASSERT(inp);
2763 if ((inp->inp_flags & INP_TIMEWAIT) ||
2764 (inp->inp_flags & INP_DROPPED))
2767 tp = intotcpcb(inp);
2768 if (tp->t_state != TCPS_SYN_SENT)
2771 if (IS_FASTOPEN(tp->t_flags))
2772 tcp_fastopen_disable_path(tp);
2774 tp = tcp_drop(tp, errno);
2782 * When `need fragmentation' ICMP is received, update our idea of the MSS
2783 * based on the new value. Also nudge TCP to send something, since we
2784 * know the packet we just sent was dropped.
2785 * This duplicates some code in the tcp_mss() function in tcp_input.c.
2787 static struct inpcb *
2788 tcp_mtudisc_notify(struct inpcb *inp, int error)
2791 tcp_mtudisc(inp, -1);
2796 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
2801 INP_WLOCK_ASSERT(inp);
2802 if ((inp->inp_flags & INP_TIMEWAIT) ||
2803 (inp->inp_flags & INP_DROPPED))
2806 tp = intotcpcb(inp);
2807 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
2809 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
2811 so = inp->inp_socket;
2812 SOCKBUF_LOCK(&so->so_snd);
2813 /* If the mss is larger than the socket buffer, decrease the mss. */
2814 if (so->so_snd.sb_hiwat < tp->t_maxseg)
2815 tp->t_maxseg = so->so_snd.sb_hiwat;
2816 SOCKBUF_UNLOCK(&so->so_snd);
2818 TCPSTAT_INC(tcps_mturesent);
2820 tp->snd_nxt = tp->snd_una;
2821 tcp_free_sackholes(tp);
2822 tp->snd_recover = tp->snd_max;
2823 if (tp->t_flags & TF_SACK_PERMIT)
2824 EXIT_FASTRECOVERY(tp->t_flags);
2825 tp->t_fb->tfb_tcp_output(tp);
2830 * Look-up the routing entry to the peer of this inpcb. If no route
2831 * is found and it cannot be allocated, then return 0. This routine
2832 * is called by TCP routines that access the rmx structure and by
2833 * tcp_mss_update to get the peer/interface MTU.
2836 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
2838 struct nhop4_extended nh4;
2840 uint32_t maxmtu = 0;
2842 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
2844 if (inc->inc_faddr.s_addr != INADDR_ANY) {
2846 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr,
2847 NHR_REF, 0, &nh4) != 0)
2851 maxmtu = nh4.nh_mtu;
2853 /* Report additional interface capabilities. */
2855 if (ifp->if_capenable & IFCAP_TSO4 &&
2856 ifp->if_hwassist & CSUM_TSO) {
2857 cap->ifcap |= CSUM_TSO;
2858 cap->tsomax = ifp->if_hw_tsomax;
2859 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
2860 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
2863 fib4_free_nh_ext(inc->inc_fibnum, &nh4);
2871 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
2873 struct nhop6_extended nh6;
2874 struct in6_addr dst6;
2877 uint32_t maxmtu = 0;
2879 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
2881 if (inc->inc_flags & INC_IPV6MINMTU)
2884 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
2885 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid);
2886 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0,
2891 maxmtu = nh6.nh_mtu;
2893 /* Report additional interface capabilities. */
2895 if (ifp->if_capenable & IFCAP_TSO6 &&
2896 ifp->if_hwassist & CSUM_TSO) {
2897 cap->ifcap |= CSUM_TSO;
2898 cap->tsomax = ifp->if_hw_tsomax;
2899 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
2900 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
2903 fib6_free_nh_ext(inc->inc_fibnum, &nh6);
2911 * Calculate effective SMSS per RFC5681 definition for a given TCP
2912 * connection at its current state, taking into account SACK and etc.
2915 tcp_maxseg(const struct tcpcb *tp)
2919 if (tp->t_flags & TF_NOOPT)
2920 return (tp->t_maxseg);
2923 * Here we have a simplified code from tcp_addoptions(),
2924 * without a proper loop, and having most of paddings hardcoded.
2925 * We might make mistakes with padding here in some edge cases,
2926 * but this is harmless, since result of tcp_maxseg() is used
2927 * only in cwnd and ssthresh estimations.
2929 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4)
2930 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
2931 if (tp->t_flags & TF_RCVD_TSTMP)
2932 optlen = TCPOLEN_TSTAMP_APPA;
2935 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
2936 if (tp->t_flags & TF_SIGNATURE)
2937 optlen += PAD(TCPOLEN_SIGNATURE);
2939 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) {
2940 optlen += TCPOLEN_SACKHDR;
2941 optlen += tp->rcv_numsacks * TCPOLEN_SACK;
2942 optlen = PAD(optlen);
2945 if (tp->t_flags & TF_REQ_TSTMP)
2946 optlen = TCPOLEN_TSTAMP_APPA;
2948 optlen = PAD(TCPOLEN_MAXSEG);
2949 if (tp->t_flags & TF_REQ_SCALE)
2950 optlen += PAD(TCPOLEN_WINDOW);
2951 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
2952 if (tp->t_flags & TF_SIGNATURE)
2953 optlen += PAD(TCPOLEN_SIGNATURE);
2955 if (tp->t_flags & TF_SACK_PERMIT)
2956 optlen += PAD(TCPOLEN_SACK_PERMITTED);
2959 optlen = min(optlen, TCP_MAXOLEN);
2960 return (tp->t_maxseg - optlen);
2964 sysctl_drop(SYSCTL_HANDLER_ARGS)
2966 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2967 struct sockaddr_storage addrs[2];
2971 struct sockaddr_in *fin, *lin;
2972 struct epoch_tracker et;
2974 struct sockaddr_in6 *fin6, *lin6;
2985 if (req->oldptr != NULL || req->oldlen != 0)
2987 if (req->newptr == NULL)
2989 if (req->newlen < sizeof(addrs))
2991 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2995 switch (addrs[0].ss_family) {
2998 fin6 = (struct sockaddr_in6 *)&addrs[0];
2999 lin6 = (struct sockaddr_in6 *)&addrs[1];
3000 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
3001 lin6->sin6_len != sizeof(struct sockaddr_in6))
3003 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
3004 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
3006 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
3007 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
3008 fin = (struct sockaddr_in *)&addrs[0];
3009 lin = (struct sockaddr_in *)&addrs[1];
3012 error = sa6_embedscope(fin6, V_ip6_use_defzone);
3015 error = sa6_embedscope(lin6, V_ip6_use_defzone);
3022 fin = (struct sockaddr_in *)&addrs[0];
3023 lin = (struct sockaddr_in *)&addrs[1];
3024 if (fin->sin_len != sizeof(struct sockaddr_in) ||
3025 lin->sin_len != sizeof(struct sockaddr_in))
3032 INP_INFO_RLOCK_ET(&V_tcbinfo, et);
3033 switch (addrs[0].ss_family) {
3036 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
3037 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
3038 INPLOOKUP_WLOCKPCB, NULL);
3043 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
3044 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
3049 if (inp->inp_flags & INP_TIMEWAIT) {
3051 * XXXRW: There currently exists a state where an
3052 * inpcb is present, but its timewait state has been
3053 * discarded. For now, don't allow dropping of this
3061 } else if (!(inp->inp_flags & INP_DROPPED) &&
3062 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
3063 tp = intotcpcb(inp);
3064 tp = tcp_drop(tp, ECONNABORTED);
3071 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
3075 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
3076 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL,
3077 0, sysctl_drop, "", "Drop TCP connection");
3080 * Generate a standardized TCP log line for use throughout the
3081 * tcp subsystem. Memory allocation is done with M_NOWAIT to
3082 * allow use in the interrupt context.
3084 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
3085 * NB: The function may return NULL if memory allocation failed.
3087 * Due to header inclusion and ordering limitations the struct ip
3088 * and ip6_hdr pointers have to be passed as void pointers.
3091 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3095 /* Is logging enabled? */
3096 if (tcp_log_in_vain == 0)
3099 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3103 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3107 /* Is logging enabled? */
3108 if (tcp_log_debug == 0)
3111 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3115 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
3122 const struct ip6_hdr *ip6;
3124 ip6 = (const struct ip6_hdr *)ip6hdr;
3126 ip = (struct ip *)ip4hdr;
3129 * The log line looks like this:
3130 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
3132 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
3133 sizeof(PRINT_TH_FLAGS) + 1 +
3135 2 * INET6_ADDRSTRLEN;
3137 2 * INET_ADDRSTRLEN;
3140 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
3144 strcat(s, "TCP: [");
3147 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
3148 inet_ntoa_r(inc->inc_faddr, sp);
3150 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3152 inet_ntoa_r(inc->inc_laddr, sp);
3154 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3157 ip6_sprintf(sp, &inc->inc6_faddr);
3159 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3161 ip6_sprintf(sp, &inc->inc6_laddr);
3163 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3164 } else if (ip6 && th) {
3165 ip6_sprintf(sp, &ip6->ip6_src);
3167 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3169 ip6_sprintf(sp, &ip6->ip6_dst);
3171 sprintf(sp, "]:%i", ntohs(th->th_dport));
3174 } else if (ip && th) {
3175 inet_ntoa_r(ip->ip_src, sp);
3177 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3179 inet_ntoa_r(ip->ip_dst, sp);
3181 sprintf(sp, "]:%i", ntohs(th->th_dport));
3189 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
3190 if (*(s + size - 1) != '\0')
3191 panic("%s: string too long", __func__);
3196 * A subroutine which makes it easy to track TCP state changes with DTrace.
3197 * This function shouldn't be called for t_state initializations that don't
3198 * correspond to actual TCP state transitions.
3201 tcp_state_change(struct tcpcb *tp, int newstate)
3203 #if defined(KDTRACE_HOOKS)
3204 int pstate = tp->t_state;
3207 TCPSTATES_DEC(tp->t_state);
3208 TCPSTATES_INC(newstate);
3209 tp->t_state = newstate;
3210 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);
3214 * Create an external-format (``xtcpcb'') structure using the information in
3215 * the kernel-format tcpcb structure pointed to by tp. This is done to
3216 * reduce the spew of irrelevant information over this interface, to isolate
3217 * user code from changes in the kernel structure, and potentially to provide
3218 * information-hiding if we decide that some of this information should be
3219 * hidden from users.
3222 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt)
3224 struct tcpcb *tp = intotcpcb(inp);
3227 bzero(xt, sizeof(*xt));
3228 if (inp->inp_flags & INP_TIMEWAIT) {
3229 xt->t_state = TCPS_TIME_WAIT;
3231 xt->t_state = tp->t_state;
3232 xt->t_logstate = tp->t_logstate;
3233 xt->t_flags = tp->t_flags;
3234 xt->t_sndzerowin = tp->t_sndzerowin;
3235 xt->t_sndrexmitpack = tp->t_sndrexmitpack;
3236 xt->t_rcvoopack = tp->t_rcvoopack;
3238 now = getsbinuptime();
3239 #define COPYTIMER(ttt) do { \
3240 if (callout_active(&tp->t_timers->ttt)) \
3241 xt->ttt = (tp->t_timers->ttt.c_time - now) / \
3246 COPYTIMER(tt_delack);
3247 COPYTIMER(tt_rexmt);
3248 COPYTIMER(tt_persist);
3252 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz;
3254 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack,
3255 TCP_FUNCTION_NAME_LEN_MAX);
3257 (void)tcp_log_get_id(tp, xt->xt_logid);
3261 xt->xt_len = sizeof(struct xtcpcb);
3262 in_pcbtoxinpcb(inp, &xt->xt_inp);
3263 if (inp->inp_socket == NULL)
3264 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP;