2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include "opt_compat.h"
37 #include "opt_inet6.h"
38 #include "opt_ipsec.h"
39 #include "opt_tcpdebug.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/callout.h>
44 #include <sys/hhook.h>
45 #include <sys/kernel.h>
46 #include <sys/khelp.h>
47 #include <sys/sysctl.h>
49 #include <sys/malloc.h>
52 #include <sys/domain.h>
56 #include <sys/socket.h>
57 #include <sys/socketvar.h>
58 #include <sys/protosw.h>
59 #include <sys/random.h>
63 #include <net/route.h>
67 #include <netinet/cc.h>
68 #include <netinet/in.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/in_var.h>
72 #include <netinet/ip.h>
73 #include <netinet/ip_icmp.h>
74 #include <netinet/ip_var.h>
76 #include <netinet/ip6.h>
77 #include <netinet6/in6_pcb.h>
78 #include <netinet6/ip6_var.h>
79 #include <netinet6/scope6_var.h>
80 #include <netinet6/nd6.h>
83 #include <netinet/tcp_fsm.h>
84 #include <netinet/tcp_seq.h>
85 #include <netinet/tcp_timer.h>
86 #include <netinet/tcp_var.h>
87 #include <netinet/tcp_syncache.h>
89 #include <netinet6/tcp6_var.h>
91 #include <netinet/tcpip.h>
93 #include <netinet/tcp_debug.h>
96 #include <netinet6/ip6protosw.h>
99 #include <netinet/tcp_offload.h>
103 #include <netipsec/ipsec.h>
104 #include <netipsec/xform.h>
106 #include <netipsec/ipsec6.h>
108 #include <netipsec/key.h>
109 #include <sys/syslog.h>
112 #include <machine/in_cksum.h>
115 #include <security/mac/mac_framework.h>
117 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
119 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
123 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
128 error = sysctl_handle_int(oidp, &new, 0, req);
129 if (error == 0 && req->newptr) {
130 if (new < TCP_MINMSS)
138 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
139 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
140 &sysctl_net_inet_tcp_mss_check, "I",
141 "Default TCP Maximum Segment Size");
145 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
149 new = V_tcp_v6mssdflt;
150 error = sysctl_handle_int(oidp, &new, 0, req);
151 if (error == 0 && req->newptr) {
152 if (new < TCP_MINMSS)
155 V_tcp_v6mssdflt = new;
160 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
161 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
162 &sysctl_net_inet_tcp_mss_v6_check, "I",
163 "Default TCP Maximum Segment Size for IPv6");
167 * Minimum MSS we accept and use. This prevents DoS attacks where
168 * we are forced to a ridiculous low MSS like 20 and send hundreds
169 * of packets instead of one. The effect scales with the available
170 * bandwidth and quickly saturates the CPU and network interface
171 * with packet generation and sending. Set to zero to disable MINMSS
172 * checking. This setting prevents us from sending too small packets.
174 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
175 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
176 &VNET_NAME(tcp_minmss), 0,
177 "Minimum TCP Maximum Segment Size");
179 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
180 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
181 &VNET_NAME(tcp_do_rfc1323), 0,
182 "Enable rfc1323 (high performance TCP) extensions");
184 static int tcp_log_debug = 0;
185 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
186 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
188 static int tcp_tcbhashsize = 0;
189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
190 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
192 static int do_tcpdrain = 1;
193 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
194 "Enable tcp_drain routine for extra help when low on mbufs");
196 SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
197 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
199 static VNET_DEFINE(int, icmp_may_rst) = 1;
200 #define V_icmp_may_rst VNET(icmp_may_rst)
201 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
202 &VNET_NAME(icmp_may_rst), 0,
203 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
205 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
206 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
207 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
208 &VNET_NAME(tcp_isn_reseed_interval), 0,
209 "Seconds between reseeding of ISN secret");
211 static int tcp_soreceive_stream = 0;
212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
213 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
216 static int tcp_sig_checksigs = 1;
217 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW,
218 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic");
221 VNET_DEFINE(uma_zone_t, sack_hole_zone);
222 #define V_sack_hole_zone VNET(sack_hole_zone)
224 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
226 static struct inpcb *tcp_notify(struct inpcb *, int);
227 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
228 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
229 void *ip4hdr, const void *ip6hdr);
232 * Target size of TCP PCB hash tables. Must be a power of two.
234 * Note that this can be overridden by the kernel environment
235 * variable net.inet.tcp.tcbhashsize
238 #define TCBHASHSIZE 512
243 * Callouts should be moved into struct tcp directly. They are currently
244 * separate because the tcpcb structure is exported to userland for sysctl
245 * parsing purposes, which do not know about callouts.
254 static VNET_DEFINE(uma_zone_t, tcpcb_zone);
255 #define V_tcpcb_zone VNET(tcpcb_zone)
257 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
258 static struct mtx isn_mtx;
260 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
261 #define ISN_LOCK() mtx_lock(&isn_mtx)
262 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
265 * TCP initialization.
268 tcp_zone_change(void *tag)
271 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
272 uma_zone_set_max(V_tcpcb_zone, maxsockets);
273 tcp_tw_zone_change();
277 tcp_inpcb_init(void *mem, int size, int flags)
279 struct inpcb *inp = mem;
281 INP_LOCK_INIT(inp, "inp", "tcpinp");
290 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
291 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
292 printf("%s: WARNING: unable to register helper hook\n", __func__);
293 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
294 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
295 printf("%s: WARNING: unable to register helper hook\n", __func__);
297 hashsize = TCBHASHSIZE;
298 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
299 if (!powerof2(hashsize)) {
300 printf("WARNING: TCB hash size not a power of 2\n");
301 hashsize = 512; /* safe default */
303 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
304 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
305 IPI_HASHFIELDS_4TUPLE);
308 * These have to be type stable for the benefit of the timers.
310 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
311 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
312 uma_zone_set_max(V_tcpcb_zone, maxsockets);
319 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
320 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
321 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
323 /* Skip initialization of globals for non-default instances. */
324 if (!IS_DEFAULT_VNET(curvnet))
327 /* XXX virtualize those bellow? */
328 tcp_delacktime = TCPTV_DELACK;
329 tcp_keepinit = TCPTV_KEEP_INIT;
330 tcp_keepidle = TCPTV_KEEP_IDLE;
331 tcp_keepintvl = TCPTV_KEEPINTVL;
332 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
334 tcp_rexmit_min = TCPTV_MIN;
335 if (tcp_rexmit_min < 1)
337 tcp_rexmit_slop = TCPTV_CPU_VAR;
338 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
339 tcp_tcbhashsize = hashsize;
341 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
342 if (tcp_soreceive_stream) {
344 tcp_usrreqs.pru_soreceive = soreceive_stream;
347 tcp6_usrreqs.pru_soreceive = soreceive_stream;
352 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
354 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
356 if (max_protohdr < TCP_MINPROTOHDR)
357 max_protohdr = TCP_MINPROTOHDR;
358 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
360 #undef TCP_MINPROTOHDR
363 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
364 SHUTDOWN_PRI_DEFAULT);
365 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
366 EVENTHANDLER_PRI_ANY);
378 in_pcbinfo_destroy(&V_tcbinfo);
379 uma_zdestroy(V_sack_hole_zone);
380 uma_zdestroy(V_tcpcb_zone);
391 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
392 * tcp_template used to store this data in mbufs, but we now recopy it out
393 * of the tcpcb each time to conserve mbufs.
396 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
398 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
400 INP_WLOCK_ASSERT(inp);
403 if ((inp->inp_vflag & INP_IPV6) != 0) {
406 ip6 = (struct ip6_hdr *)ip_ptr;
407 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
408 (inp->inp_flow & IPV6_FLOWINFO_MASK);
409 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
410 (IPV6_VERSION & IPV6_VERSION_MASK);
411 ip6->ip6_nxt = IPPROTO_TCP;
412 ip6->ip6_plen = htons(sizeof(struct tcphdr));
413 ip6->ip6_src = inp->in6p_laddr;
414 ip6->ip6_dst = inp->in6p_faddr;
417 #if defined(INET6) && defined(INET)
424 ip = (struct ip *)ip_ptr;
425 ip->ip_v = IPVERSION;
427 ip->ip_tos = inp->inp_ip_tos;
431 ip->ip_ttl = inp->inp_ip_ttl;
433 ip->ip_p = IPPROTO_TCP;
434 ip->ip_src = inp->inp_laddr;
435 ip->ip_dst = inp->inp_faddr;
438 th->th_sport = inp->inp_lport;
439 th->th_dport = inp->inp_fport;
447 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
451 * Create template to be used to send tcp packets on a connection.
452 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
453 * use for this function is in keepalives, which use tcp_respond.
456 tcpip_maketemplate(struct inpcb *inp)
460 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
463 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
468 * Send a single message to the TCP at address specified by
469 * the given TCP/IP header. If m == NULL, then we make a copy
470 * of the tcpiphdr at ti and send directly to the addressed host.
471 * This is used to force keep alive messages out using the TCP
472 * template for a connection. If flags are given then we send
473 * a message back to the TCP which originated the * segment ti,
474 * and discard the mbuf containing it and any other attached mbufs.
476 * In any case the ack and sequence number of the transmitted
477 * segment are as specified by the parameters.
479 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
482 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
483 tcp_seq ack, tcp_seq seq, int flags)
496 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
499 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
506 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
507 INP_WLOCK_ASSERT(inp);
512 if (!(flags & TH_RST)) {
513 win = sbspace(&inp->inp_socket->so_rcv);
514 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
515 win = (long)TCP_MAXWIN << tp->rcv_scale;
519 m = m_gethdr(M_DONTWAIT, MT_DATA);
523 m->m_data += max_linkhdr;
526 bcopy((caddr_t)ip6, mtod(m, caddr_t),
527 sizeof(struct ip6_hdr));
528 ip6 = mtod(m, struct ip6_hdr *);
529 nth = (struct tcphdr *)(ip6 + 1);
533 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
534 ip = mtod(m, struct ip *);
535 nth = (struct tcphdr *)(ip + 1);
537 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
542 * XXX MRT We inherrit the FIB, which is lucky.
546 m->m_data = (caddr_t)ipgen;
548 /* m_len is set later */
550 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
553 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
554 nth = (struct tcphdr *)(ip6 + 1);
558 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
559 nth = (struct tcphdr *)(ip + 1);
563 * this is usually a case when an extension header
564 * exists between the IPv6 header and the
567 nth->th_sport = th->th_sport;
568 nth->th_dport = th->th_dport;
570 xchg(nth->th_dport, nth->th_sport, uint16_t);
576 ip6->ip6_vfc = IPV6_VERSION;
577 ip6->ip6_nxt = IPPROTO_TCP;
578 ip6->ip6_plen = 0; /* Set in ip6_output(). */
579 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
582 #if defined(INET) && defined(INET6)
587 tlen += sizeof (struct tcpiphdr);
589 ip->ip_ttl = V_ip_defttl;
590 if (V_path_mtu_discovery)
595 m->m_pkthdr.len = tlen;
596 m->m_pkthdr.rcvif = NULL;
600 * Packet is associated with a socket, so allow the
601 * label of the response to reflect the socket label.
603 INP_WLOCK_ASSERT(inp);
604 mac_inpcb_create_mbuf(inp, m);
607 * Packet is not associated with a socket, so possibly
608 * update the label in place.
610 mac_netinet_tcp_reply(m);
613 nth->th_seq = htonl(seq);
614 nth->th_ack = htonl(ack);
616 nth->th_off = sizeof (struct tcphdr) >> 2;
617 nth->th_flags = flags;
619 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
621 nth->th_win = htons((u_short)win);
624 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
627 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
628 nth->th_sum = in6_cksum_pseudo(ip6,
629 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
630 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
634 #if defined(INET6) && defined(INET)
639 m->m_pkthdr.csum_flags = CSUM_TCP;
640 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
641 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
645 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
646 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
650 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
652 #if defined(INET) && defined(INET6)
656 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
661 * Create a new TCP control block, making an
662 * empty reassembly queue and hooking it to the argument
663 * protocol control block. The `inp' parameter must have
664 * come from the zone allocator set up in tcp_init().
667 tcp_newtcpcb(struct inpcb *inp)
669 struct tcpcb_mem *tm;
672 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
675 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
680 /* Initialise cc_var struct for this tcpcb. */
682 tp->ccv->type = IPPROTO_TCP;
683 tp->ccv->ccvc.tcp = tp;
686 * Use the current system default CC algorithm.
689 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
690 CC_ALGO(tp) = CC_DEFAULT();
693 if (CC_ALGO(tp)->cb_init != NULL)
694 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
695 uma_zfree(V_tcpcb_zone, tm);
700 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
701 uma_zfree(V_tcpcb_zone, tm);
706 tp->t_vnet = inp->inp_vnet;
708 tp->t_timers = &tm->tt;
709 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
710 tp->t_maxseg = tp->t_maxopd =
712 isipv6 ? V_tcp_v6mssdflt :
716 /* Set up our timeouts. */
717 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
718 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
719 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
720 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
721 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
723 if (V_tcp_do_rfc1323)
724 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
726 tp->t_flags |= TF_SACK_PERMIT;
727 TAILQ_INIT(&tp->snd_holes);
728 tp->t_inpcb = inp; /* XXX */
730 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
731 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
732 * reasonable initial retransmit time.
734 tp->t_srtt = TCPTV_SRTTBASE;
735 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
736 tp->t_rttmin = tcp_rexmit_min;
737 tp->t_rxtcur = TCPTV_RTOBASE;
738 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
739 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
740 tp->t_rcvtime = ticks;
742 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
743 * because the socket may be bound to an IPv6 wildcard address,
744 * which may match an IPv4-mapped IPv6 address.
746 inp->inp_ip_ttl = V_ip_defttl;
748 return (tp); /* XXX */
752 * Switch the congestion control algorithm back to NewReno for any active
753 * control blocks using an algorithm which is about to go away.
754 * This ensures the CC framework can allow the unload to proceed without leaving
755 * any dangling pointers which would trigger a panic.
756 * Returning non-zero would inform the CC framework that something went wrong
757 * and it would be unsafe to allow the unload to proceed. However, there is no
758 * way for this to occur with this implementation so we always return zero.
761 tcp_ccalgounload(struct cc_algo *unload_algo)
763 struct cc_algo *tmpalgo;
766 VNET_ITERATOR_DECL(vnet_iter);
769 * Check all active control blocks across all network stacks and change
770 * any that are using "unload_algo" back to NewReno. If "unload_algo"
771 * requires cleanup code to be run, call it.
774 VNET_FOREACH(vnet_iter) {
775 CURVNET_SET(vnet_iter);
776 INP_INFO_RLOCK(&V_tcbinfo);
778 * New connections already part way through being initialised
779 * with the CC algo we're removing will not race with this code
780 * because the INP_INFO_WLOCK is held during initialisation. We
781 * therefore don't enter the loop below until the connection
782 * list has stabilised.
784 LIST_FOREACH(inp, &V_tcb, inp_list) {
786 /* Important to skip tcptw structs. */
787 if (!(inp->inp_flags & INP_TIMEWAIT) &&
788 (tp = intotcpcb(inp)) != NULL) {
790 * By holding INP_WLOCK here, we are assured
791 * that the connection is not currently
792 * executing inside the CC module's functions
793 * i.e. it is safe to make the switch back to
796 if (CC_ALGO(tp) == unload_algo) {
797 tmpalgo = CC_ALGO(tp);
798 /* NewReno does not require any init. */
799 CC_ALGO(tp) = &newreno_cc_algo;
800 if (tmpalgo->cb_destroy != NULL)
801 tmpalgo->cb_destroy(tp->ccv);
806 INP_INFO_RUNLOCK(&V_tcbinfo);
815 * Drop a TCP connection, reporting
816 * the specified error. If connection is synchronized,
817 * then send a RST to peer.
820 tcp_drop(struct tcpcb *tp, int errno)
822 struct socket *so = tp->t_inpcb->inp_socket;
824 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
825 INP_WLOCK_ASSERT(tp->t_inpcb);
827 if (TCPS_HAVERCVDSYN(tp->t_state)) {
828 tp->t_state = TCPS_CLOSED;
829 (void) tcp_output(tp);
830 TCPSTAT_INC(tcps_drops);
832 TCPSTAT_INC(tcps_conndrops);
833 if (errno == ETIMEDOUT && tp->t_softerror)
834 errno = tp->t_softerror;
835 so->so_error = errno;
836 return (tcp_close(tp));
840 tcp_discardcb(struct tcpcb *tp)
842 struct inpcb *inp = tp->t_inpcb;
843 struct socket *so = inp->inp_socket;
845 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
848 INP_WLOCK_ASSERT(inp);
851 * Make sure that all of our timers are stopped before we delete the
854 * XXXRW: Really, we would like to use callout_drain() here in order
855 * to avoid races experienced in tcp_timer.c where a timer is already
856 * executing at this point. However, we can't, both because we're
857 * running in a context where we can't sleep, and also because we
858 * hold locks required by the timers. What we instead need to do is
859 * test to see if callout_drain() is required, and if so, defer some
860 * portion of the remainder of tcp_discardcb() to an asynchronous
861 * context that can callout_drain() and then continue. Some care
862 * will be required to ensure that no further processing takes place
863 * on the tcpcb, even though it hasn't been freed (a flag?).
865 callout_stop(&tp->t_timers->tt_rexmt);
866 callout_stop(&tp->t_timers->tt_persist);
867 callout_stop(&tp->t_timers->tt_keep);
868 callout_stop(&tp->t_timers->tt_2msl);
869 callout_stop(&tp->t_timers->tt_delack);
872 * If we got enough samples through the srtt filter,
873 * save the rtt and rttvar in the routing entry.
874 * 'Enough' is arbitrarily defined as 4 rtt samples.
875 * 4 samples is enough for the srtt filter to converge
876 * to within enough % of the correct value; fewer samples
877 * and we could save a bogus rtt. The danger is not high
878 * as tcp quickly recovers from everything.
879 * XXX: Works very well but needs some more statistics!
881 if (tp->t_rttupdated >= 4) {
882 struct hc_metrics_lite metrics;
885 bzero(&metrics, sizeof(metrics));
887 * Update the ssthresh always when the conditions below
888 * are satisfied. This gives us better new start value
889 * for the congestion avoidance for new connections.
890 * ssthresh is only set if packet loss occured on a session.
892 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
893 * being torn down. Ideally this code would not use 'so'.
895 ssthresh = tp->snd_ssthresh;
896 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
898 * convert the limit from user data bytes to
899 * packets then to packet data bytes.
901 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
904 ssthresh *= (u_long)(tp->t_maxseg +
906 (isipv6 ? sizeof (struct ip6_hdr) +
907 sizeof (struct tcphdr) :
909 sizeof (struct tcpiphdr)
916 metrics.rmx_ssthresh = ssthresh;
918 metrics.rmx_rtt = tp->t_srtt;
919 metrics.rmx_rttvar = tp->t_rttvar;
920 metrics.rmx_cwnd = tp->snd_cwnd;
921 metrics.rmx_sendpipe = 0;
922 metrics.rmx_recvpipe = 0;
924 tcp_hc_update(&inp->inp_inc, &metrics);
927 /* free the reassembly queue, if any */
931 /* Disconnect offload device, if any. */
932 if (tp->t_flags & TF_TOE)
933 tcp_offload_detach(tp);
936 tcp_free_sackholes(tp);
938 /* Allow the CC algorithm to clean up after itself. */
939 if (CC_ALGO(tp)->cb_destroy != NULL)
940 CC_ALGO(tp)->cb_destroy(tp->ccv);
942 khelp_destroy_osd(tp->osd);
945 inp->inp_ppcb = NULL;
947 uma_zfree(V_tcpcb_zone, tp);
951 * Attempt to close a TCP control block, marking it as dropped, and freeing
952 * the socket if we hold the only reference.
955 tcp_close(struct tcpcb *tp)
957 struct inpcb *inp = tp->t_inpcb;
960 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
961 INP_WLOCK_ASSERT(inp);
964 if (tp->t_state == TCPS_LISTEN)
965 tcp_offload_listen_stop(tp);
968 TCPSTAT_INC(tcps_closed);
969 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
970 so = inp->inp_socket;
971 soisdisconnected(so);
972 if (inp->inp_flags & INP_SOCKREF) {
973 KASSERT(so->so_state & SS_PROTOREF,
974 ("tcp_close: !SS_PROTOREF"));
975 inp->inp_flags &= ~INP_SOCKREF;
979 so->so_state &= ~SS_PROTOREF;
989 VNET_ITERATOR_DECL(vnet_iter);
994 VNET_LIST_RLOCK_NOSLEEP();
995 VNET_FOREACH(vnet_iter) {
996 CURVNET_SET(vnet_iter);
1001 * Walk the tcpbs, if existing, and flush the reassembly queue,
1002 * if there is one...
1003 * XXX: The "Net/3" implementation doesn't imply that the TCP
1004 * reassembly queue should be flushed, but in a situation
1005 * where we're really low on mbufs, this is potentially
1008 INP_INFO_RLOCK(&V_tcbinfo);
1009 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1010 if (inpb->inp_flags & INP_TIMEWAIT)
1013 if ((tcpb = intotcpcb(inpb)) != NULL) {
1014 tcp_reass_flush(tcpb);
1015 tcp_clean_sackreport(tcpb);
1019 INP_INFO_RUNLOCK(&V_tcbinfo);
1022 VNET_LIST_RUNLOCK_NOSLEEP();
1026 * Notify a tcp user of an asynchronous error;
1027 * store error as soft error, but wake up user
1028 * (for now, won't do anything until can select for soft error).
1030 * Do not wake up user since there currently is no mechanism for
1031 * reporting soft errors (yet - a kqueue filter may be added).
1033 static struct inpcb *
1034 tcp_notify(struct inpcb *inp, int error)
1038 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1039 INP_WLOCK_ASSERT(inp);
1041 if ((inp->inp_flags & INP_TIMEWAIT) ||
1042 (inp->inp_flags & INP_DROPPED))
1045 tp = intotcpcb(inp);
1046 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1049 * Ignore some errors if we are hooked up.
1050 * If connection hasn't completed, has retransmitted several times,
1051 * and receives a second error, give up now. This is better
1052 * than waiting a long time to establish a connection that
1053 * can never complete.
1055 if (tp->t_state == TCPS_ESTABLISHED &&
1056 (error == EHOSTUNREACH || error == ENETUNREACH ||
1057 error == EHOSTDOWN)) {
1059 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1061 tp = tcp_drop(tp, error);
1067 tp->t_softerror = error;
1071 wakeup( &so->so_timeo);
1078 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1080 int error, i, m, n, pcb_count;
1081 struct inpcb *inp, **inp_list;
1086 * The process of preparing the TCB list is too time-consuming and
1087 * resource-intensive to repeat twice on every request.
1089 if (req->oldptr == NULL) {
1090 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1091 n += imax(n / 8, 10);
1092 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1096 if (req->newptr != NULL)
1100 * OK, now we're committed to doing something.
1102 INP_INFO_RLOCK(&V_tcbinfo);
1103 gencnt = V_tcbinfo.ipi_gencnt;
1104 n = V_tcbinfo.ipi_count;
1105 INP_INFO_RUNLOCK(&V_tcbinfo);
1107 m = syncache_pcbcount();
1109 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1110 + (n + m) * sizeof(struct xtcpcb));
1114 xig.xig_len = sizeof xig;
1115 xig.xig_count = n + m;
1116 xig.xig_gen = gencnt;
1117 xig.xig_sogen = so_gencnt;
1118 error = SYSCTL_OUT(req, &xig, sizeof xig);
1122 error = syncache_pcblist(req, m, &pcb_count);
1126 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1127 if (inp_list == NULL)
1130 INP_INFO_RLOCK(&V_tcbinfo);
1131 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1132 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1134 if (inp->inp_gencnt <= gencnt) {
1136 * XXX: This use of cr_cansee(), introduced with
1137 * TCP state changes, is not quite right, but for
1138 * now, better than nothing.
1140 if (inp->inp_flags & INP_TIMEWAIT) {
1141 if (intotw(inp) != NULL)
1142 error = cr_cansee(req->td->td_ucred,
1143 intotw(inp)->tw_cred);
1145 error = EINVAL; /* Skip this inp. */
1147 error = cr_canseeinpcb(req->td->td_ucred, inp);
1150 inp_list[i++] = inp;
1155 INP_INFO_RUNLOCK(&V_tcbinfo);
1159 for (i = 0; i < n; i++) {
1162 if (inp->inp_gencnt <= gencnt) {
1166 bzero(&xt, sizeof(xt));
1167 xt.xt_len = sizeof xt;
1168 /* XXX should avoid extra copy */
1169 bcopy(inp, &xt.xt_inp, sizeof *inp);
1170 inp_ppcb = inp->inp_ppcb;
1171 if (inp_ppcb == NULL)
1172 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1173 else if (inp->inp_flags & INP_TIMEWAIT) {
1174 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1175 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1177 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1178 if (xt.xt_tp.t_timers)
1179 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1181 if (inp->inp_socket != NULL)
1182 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1184 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1185 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1187 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1189 error = SYSCTL_OUT(req, &xt, sizeof xt);
1193 INP_INFO_WLOCK(&V_tcbinfo);
1194 for (i = 0; i < n; i++) {
1197 if (!in_pcbrele_rlocked(inp))
1200 INP_INFO_WUNLOCK(&V_tcbinfo);
1204 * Give the user an updated idea of our state.
1205 * If the generation differs from what we told
1206 * her before, she knows that something happened
1207 * while we were processing this request, and it
1208 * might be necessary to retry.
1210 INP_INFO_RLOCK(&V_tcbinfo);
1211 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1212 xig.xig_sogen = so_gencnt;
1213 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1214 INP_INFO_RUNLOCK(&V_tcbinfo);
1215 error = SYSCTL_OUT(req, &xig, sizeof xig);
1217 free(inp_list, M_TEMP);
1221 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1222 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1223 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1227 tcp_getcred(SYSCTL_HANDLER_ARGS)
1230 struct sockaddr_in addrs[2];
1234 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1237 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1240 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1241 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1243 if (inp->inp_socket == NULL)
1246 error = cr_canseeinpcb(req->td->td_ucred, inp);
1248 cru2x(inp->inp_cred, &xuc);
1253 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1257 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1258 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1259 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1264 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1267 struct sockaddr_in6 addrs[2];
1274 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1277 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1280 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1281 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1284 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1286 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1295 inp = in_pcblookup(&V_tcbinfo,
1296 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1298 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1299 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1302 inp = in6_pcblookup(&V_tcbinfo,
1303 &addrs[1].sin6_addr, addrs[1].sin6_port,
1304 &addrs[0].sin6_addr, addrs[0].sin6_port,
1305 INPLOOKUP_RLOCKPCB, NULL);
1307 if (inp->inp_socket == NULL)
1310 error = cr_canseeinpcb(req->td->td_ucred, inp);
1312 cru2x(inp->inp_cred, &xuc);
1317 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1321 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1322 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1323 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1329 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1331 struct ip *ip = vip;
1333 struct in_addr faddr;
1336 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1338 struct in_conninfo inc;
1339 tcp_seq icmp_tcp_seq;
1342 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1343 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1346 if (cmd == PRC_MSGSIZE)
1347 notify = tcp_mtudisc_notify;
1348 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1349 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1350 notify = tcp_drop_syn_sent;
1352 * Redirects don't need to be handled up here.
1354 else if (PRC_IS_REDIRECT(cmd))
1357 * Source quench is depreciated.
1359 else if (cmd == PRC_QUENCH)
1362 * Hostdead is ugly because it goes linearly through all PCBs.
1363 * XXX: We never get this from ICMP, otherwise it makes an
1364 * excellent DoS attack on machines with many connections.
1366 else if (cmd == PRC_HOSTDEAD)
1368 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1371 icp = (struct icmp *)((caddr_t)ip
1372 - offsetof(struct icmp, icmp_ip));
1373 th = (struct tcphdr *)((caddr_t)ip
1374 + (ip->ip_hl << 2));
1375 INP_INFO_WLOCK(&V_tcbinfo);
1376 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1377 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1379 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1380 !(inp->inp_flags & INP_DROPPED) &&
1381 !(inp->inp_socket == NULL)) {
1382 icmp_tcp_seq = htonl(th->th_seq);
1383 tp = intotcpcb(inp);
1384 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1385 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1386 if (cmd == PRC_MSGSIZE) {
1389 * If we got a needfrag set the MTU
1390 * in the route to the suggested new
1391 * value (if given) and then notify.
1393 bzero(&inc, sizeof(inc));
1394 inc.inc_faddr = faddr;
1396 inp->inp_inc.inc_fibnum;
1398 mtu = ntohs(icp->icmp_nextmtu);
1400 * If no alternative MTU was
1401 * proposed, try the next smaller
1402 * one. ip->ip_len has already
1403 * been swapped in icmp_input().
1406 mtu = ip_next_mtu(ip->ip_len,
1408 if (mtu < V_tcp_minmss
1409 + sizeof(struct tcpiphdr))
1411 + sizeof(struct tcpiphdr);
1413 * Only cache the MTU if it
1414 * is smaller than the interface
1415 * or route MTU. tcp_mtudisc()
1416 * will do right thing by itself.
1418 if (mtu <= tcp_maxmtu(&inc, NULL))
1419 tcp_hc_updatemtu(&inc, mtu);
1420 tcp_mtudisc(inp, mtu);
1422 inp = (*notify)(inp,
1423 inetctlerrmap[cmd]);
1429 bzero(&inc, sizeof(inc));
1430 inc.inc_fport = th->th_dport;
1431 inc.inc_lport = th->th_sport;
1432 inc.inc_faddr = faddr;
1433 inc.inc_laddr = ip->ip_src;
1434 syncache_unreach(&inc, th);
1436 INP_INFO_WUNLOCK(&V_tcbinfo);
1438 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1444 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1447 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1448 struct ip6_hdr *ip6;
1450 struct ip6ctlparam *ip6cp = NULL;
1451 const struct sockaddr_in6 *sa6_src = NULL;
1453 struct tcp_portonly {
1458 if (sa->sa_family != AF_INET6 ||
1459 sa->sa_len != sizeof(struct sockaddr_in6))
1462 if (cmd == PRC_MSGSIZE)
1463 notify = tcp_mtudisc_notify;
1464 else if (!PRC_IS_REDIRECT(cmd) &&
1465 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1467 /* Source quench is depreciated. */
1468 else if (cmd == PRC_QUENCH)
1471 /* if the parameter is from icmp6, decode it. */
1473 ip6cp = (struct ip6ctlparam *)d;
1475 ip6 = ip6cp->ip6c_ip6;
1476 off = ip6cp->ip6c_off;
1477 sa6_src = ip6cp->ip6c_src;
1481 off = 0; /* fool gcc */
1486 struct in_conninfo inc;
1488 * XXX: We assume that when IPV6 is non NULL,
1489 * M and OFF are valid.
1492 /* check if we can safely examine src and dst ports */
1493 if (m->m_pkthdr.len < off + sizeof(*thp))
1496 bzero(&th, sizeof(th));
1497 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1499 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1500 (struct sockaddr *)ip6cp->ip6c_src,
1501 th.th_sport, cmd, NULL, notify);
1503 bzero(&inc, sizeof(inc));
1504 inc.inc_fport = th.th_dport;
1505 inc.inc_lport = th.th_sport;
1506 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1507 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1508 inc.inc_flags |= INC_ISIPV6;
1509 INP_INFO_WLOCK(&V_tcbinfo);
1510 syncache_unreach(&inc, &th);
1511 INP_INFO_WUNLOCK(&V_tcbinfo);
1513 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1514 0, cmd, NULL, notify);
1520 * Following is where TCP initial sequence number generation occurs.
1522 * There are two places where we must use initial sequence numbers:
1523 * 1. In SYN-ACK packets.
1524 * 2. In SYN packets.
1526 * All ISNs for SYN-ACK packets are generated by the syncache. See
1527 * tcp_syncache.c for details.
1529 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1530 * depends on this property. In addition, these ISNs should be
1531 * unguessable so as to prevent connection hijacking. To satisfy
1532 * the requirements of this situation, the algorithm outlined in
1533 * RFC 1948 is used, with only small modifications.
1535 * Implementation details:
1537 * Time is based off the system timer, and is corrected so that it
1538 * increases by one megabyte per second. This allows for proper
1539 * recycling on high speed LANs while still leaving over an hour
1542 * As reading the *exact* system time is too expensive to be done
1543 * whenever setting up a TCP connection, we increment the time
1544 * offset in two ways. First, a small random positive increment
1545 * is added to isn_offset for each connection that is set up.
1546 * Second, the function tcp_isn_tick fires once per clock tick
1547 * and increments isn_offset as necessary so that sequence numbers
1548 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1549 * random positive increments serve only to ensure that the same
1550 * exact sequence number is never sent out twice (as could otherwise
1551 * happen when a port is recycled in less than the system tick
1554 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1555 * between seeding of isn_secret. This is normally set to zero,
1556 * as reseeding should not be necessary.
1558 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1559 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1560 * general, this means holding an exclusive (write) lock.
1563 #define ISN_BYTES_PER_SECOND 1048576
1564 #define ISN_STATIC_INCREMENT 4096
1565 #define ISN_RANDOM_INCREMENT (4096 - 1)
1567 static VNET_DEFINE(u_char, isn_secret[32]);
1568 static VNET_DEFINE(int, isn_last);
1569 static VNET_DEFINE(int, isn_last_reseed);
1570 static VNET_DEFINE(u_int32_t, isn_offset);
1571 static VNET_DEFINE(u_int32_t, isn_offset_old);
1573 #define V_isn_secret VNET(isn_secret)
1574 #define V_isn_last VNET(isn_last)
1575 #define V_isn_last_reseed VNET(isn_last_reseed)
1576 #define V_isn_offset VNET(isn_offset)
1577 #define V_isn_offset_old VNET(isn_offset_old)
1580 tcp_new_isn(struct tcpcb *tp)
1583 u_int32_t md5_buffer[4];
1585 u_int32_t projected_offset;
1587 INP_WLOCK_ASSERT(tp->t_inpcb);
1590 /* Seed if this is the first use, reseed if requested. */
1591 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1592 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1594 read_random(&V_isn_secret, sizeof(V_isn_secret));
1595 V_isn_last_reseed = ticks;
1598 /* Compute the md5 hash and return the ISN. */
1600 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1601 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1603 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1604 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1605 sizeof(struct in6_addr));
1606 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1607 sizeof(struct in6_addr));
1611 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1612 sizeof(struct in_addr));
1613 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1614 sizeof(struct in_addr));
1616 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1617 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1618 new_isn = (tcp_seq) md5_buffer[0];
1619 V_isn_offset += ISN_STATIC_INCREMENT +
1620 (arc4random() & ISN_RANDOM_INCREMENT);
1621 if (ticks != V_isn_last) {
1622 projected_offset = V_isn_offset_old +
1623 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1624 if (SEQ_GT(projected_offset, V_isn_offset))
1625 V_isn_offset = projected_offset;
1626 V_isn_offset_old = V_isn_offset;
1629 new_isn += V_isn_offset;
1635 * When a specific ICMP unreachable message is received and the
1636 * connection state is SYN-SENT, drop the connection. This behavior
1637 * is controlled by the icmp_may_rst sysctl.
1640 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1644 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1645 INP_WLOCK_ASSERT(inp);
1647 if ((inp->inp_flags & INP_TIMEWAIT) ||
1648 (inp->inp_flags & INP_DROPPED))
1651 tp = intotcpcb(inp);
1652 if (tp->t_state != TCPS_SYN_SENT)
1655 tp = tcp_drop(tp, errno);
1663 * When `need fragmentation' ICMP is received, update our idea of the MSS
1664 * based on the new value. Also nudge TCP to send something, since we
1665 * know the packet we just sent was dropped.
1666 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1668 static struct inpcb *
1669 tcp_mtudisc_notify(struct inpcb *inp, int error)
1672 return (tcp_mtudisc(inp, -1));
1676 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1681 INP_WLOCK_ASSERT(inp);
1682 if ((inp->inp_flags & INP_TIMEWAIT) ||
1683 (inp->inp_flags & INP_DROPPED))
1686 tp = intotcpcb(inp);
1687 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1689 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1691 so = inp->inp_socket;
1692 SOCKBUF_LOCK(&so->so_snd);
1693 /* If the mss is larger than the socket buffer, decrease the mss. */
1694 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1695 tp->t_maxseg = so->so_snd.sb_hiwat;
1696 SOCKBUF_UNLOCK(&so->so_snd);
1698 TCPSTAT_INC(tcps_mturesent);
1700 tp->snd_nxt = tp->snd_una;
1701 tcp_free_sackholes(tp);
1702 tp->snd_recover = tp->snd_max;
1703 if (tp->t_flags & TF_SACK_PERMIT)
1704 EXIT_FASTRECOVERY(tp->t_flags);
1711 * Look-up the routing entry to the peer of this inpcb. If no route
1712 * is found and it cannot be allocated, then return 0. This routine
1713 * is called by TCP routines that access the rmx structure and by
1714 * tcp_mss_update to get the peer/interface MTU.
1717 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1720 struct sockaddr_in *dst;
1724 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1726 bzero(&sro, sizeof(sro));
1727 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1728 dst = (struct sockaddr_in *)&sro.ro_dst;
1729 dst->sin_family = AF_INET;
1730 dst->sin_len = sizeof(*dst);
1731 dst->sin_addr = inc->inc_faddr;
1732 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1734 if (sro.ro_rt != NULL) {
1735 ifp = sro.ro_rt->rt_ifp;
1736 if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
1737 maxmtu = ifp->if_mtu;
1739 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
1741 /* Report additional interface capabilities. */
1743 if (ifp->if_capenable & IFCAP_TSO4 &&
1744 ifp->if_hwassist & CSUM_TSO) {
1745 cap->ifcap |= CSUM_TSO;
1746 cap->tsomax = ifp->if_hw_tsomax;
1757 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1759 struct route_in6 sro6;
1763 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1765 bzero(&sro6, sizeof(sro6));
1766 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1767 sro6.ro_dst.sin6_family = AF_INET6;
1768 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1769 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1770 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1772 if (sro6.ro_rt != NULL) {
1773 ifp = sro6.ro_rt->rt_ifp;
1774 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
1775 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1777 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
1778 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1780 /* Report additional interface capabilities. */
1782 if (ifp->if_capenable & IFCAP_TSO6 &&
1783 ifp->if_hwassist & CSUM_TSO) {
1784 cap->ifcap |= CSUM_TSO;
1785 cap->tsomax = ifp->if_hw_tsomax;
1796 /* compute ESP/AH header size for TCP, including outer IP header. */
1798 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1805 struct ip6_hdr *ip6;
1809 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1811 MGETHDR(m, M_DONTWAIT, MT_DATA);
1816 if ((inp->inp_vflag & INP_IPV6) != 0) {
1817 ip6 = mtod(m, struct ip6_hdr *);
1818 th = (struct tcphdr *)(ip6 + 1);
1819 m->m_pkthdr.len = m->m_len =
1820 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1821 tcpip_fillheaders(inp, ip6, th);
1822 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1826 ip = mtod(m, struct ip *);
1827 th = (struct tcphdr *)(ip + 1);
1828 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1829 tcpip_fillheaders(inp, ip, th);
1830 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1838 #ifdef TCP_SIGNATURE
1840 * Callback function invoked by m_apply() to digest TCP segment data
1841 * contained within an mbuf chain.
1844 tcp_signature_apply(void *fstate, void *data, u_int len)
1847 MD5Update(fstate, (u_char *)data, len);
1852 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1855 * m pointer to head of mbuf chain
1857 * len length of TCP segment data, excluding options
1858 * optlen length of TCP segment options
1859 * buf pointer to storage for computed MD5 digest
1860 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1862 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1863 * When called from tcp_input(), we can be sure that th_sum has been
1864 * zeroed out and verified already.
1866 * Return 0 if successful, otherwise return -1.
1868 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1869 * search with the destination IP address, and a 'magic SPI' to be
1870 * determined by the application. This is hardcoded elsewhere to 1179
1871 * right now. Another branch of this code exists which uses the SPD to
1872 * specify per-application flows but it is unstable.
1875 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1876 u_char *buf, u_int direction)
1878 union sockaddr_union dst;
1880 struct ippseudo ippseudo;
1886 struct ipovly *ipovly;
1888 struct secasvar *sav;
1891 struct ip6_hdr *ip6;
1892 struct in6_addr in6;
1893 char ip6buf[INET6_ADDRSTRLEN];
1899 KASSERT(m != NULL, ("NULL mbuf chain"));
1900 KASSERT(buf != NULL, ("NULL signature pointer"));
1902 /* Extract the destination from the IP header in the mbuf. */
1903 bzero(&dst, sizeof(union sockaddr_union));
1904 ip = mtod(m, struct ip *);
1906 ip6 = NULL; /* Make the compiler happy. */
1911 dst.sa.sa_len = sizeof(struct sockaddr_in);
1912 dst.sa.sa_family = AF_INET;
1913 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1914 ip->ip_src : ip->ip_dst;
1918 case (IPV6_VERSION >> 4):
1919 ip6 = mtod(m, struct ip6_hdr *);
1920 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1921 dst.sa.sa_family = AF_INET6;
1922 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1923 ip6->ip6_src : ip6->ip6_dst;
1932 /* Look up an SADB entry which matches the address of the peer. */
1933 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1935 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
1936 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
1938 (ip->ip_v == (IPV6_VERSION >> 4)) ?
1939 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
1947 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
1949 * XXX The ippseudo header MUST be digested in network byte order,
1950 * or else we'll fail the regression test. Assume all fields we've
1951 * been doing arithmetic on have been in host byte order.
1952 * XXX One cannot depend on ipovly->ih_len here. When called from
1953 * tcp_output(), the underlying ip_len member has not yet been set.
1958 ipovly = (struct ipovly *)ip;
1959 ippseudo.ippseudo_src = ipovly->ih_src;
1960 ippseudo.ippseudo_dst = ipovly->ih_dst;
1961 ippseudo.ippseudo_pad = 0;
1962 ippseudo.ippseudo_p = IPPROTO_TCP;
1963 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
1965 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
1967 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
1968 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
1973 * RFC 2385, 2.0 Proposal
1974 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
1975 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
1976 * extended next header value (to form 32 bits), and 32-bit segment
1978 * Note: Upper-Layer Packet Length comes before Next Header.
1980 case (IPV6_VERSION >> 4):
1982 in6_clearscope(&in6);
1983 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1985 in6_clearscope(&in6);
1986 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1987 plen = htonl(len + sizeof(struct tcphdr) + optlen);
1988 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
1990 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1991 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1992 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1994 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1996 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
1997 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2008 * Step 2: Update MD5 hash with TCP header, excluding options.
2009 * The TCP checksum must be set to zero.
2011 savecsum = th->th_sum;
2013 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2014 th->th_sum = savecsum;
2017 * Step 3: Update MD5 hash with TCP segment data.
2018 * Use m_apply() to avoid an early m_pullup().
2021 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2024 * Step 4: Update MD5 hash with shared secret.
2026 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2027 MD5Final(buf, &ctx);
2029 key_sa_recordxfer(sav, m);
2035 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2038 * m pointer to head of mbuf chain
2039 * len length of TCP segment data, excluding options
2040 * optlen length of TCP segment options
2041 * buf pointer to storage for computed MD5 digest
2042 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2044 * Return 1 if successful, otherwise return 0.
2047 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2048 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2050 char tmpdigest[TCP_SIGLEN];
2052 if (tcp_sig_checksigs == 0)
2054 if ((tcpbflag & TF_SIGNATURE) == 0) {
2055 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2058 * If this socket is not expecting signature but
2059 * the segment contains signature just fail.
2061 TCPSTAT_INC(tcps_sig_err_sigopt);
2062 TCPSTAT_INC(tcps_sig_rcvbadsig);
2066 /* Signature is not expected, and not present in segment. */
2071 * If this socket is expecting signature but the segment does not
2072 * contain any just fail.
2074 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2075 TCPSTAT_INC(tcps_sig_err_nosigopt);
2076 TCPSTAT_INC(tcps_sig_rcvbadsig);
2079 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2080 IPSEC_DIR_INBOUND) == -1) {
2081 TCPSTAT_INC(tcps_sig_err_buildsig);
2082 TCPSTAT_INC(tcps_sig_rcvbadsig);
2086 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2087 TCPSTAT_INC(tcps_sig_rcvbadsig);
2090 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2093 #endif /* TCP_SIGNATURE */
2096 sysctl_drop(SYSCTL_HANDLER_ARGS)
2098 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2099 struct sockaddr_storage addrs[2];
2103 struct sockaddr_in *fin, *lin;
2105 struct sockaddr_in6 *fin6, *lin6;
2116 if (req->oldptr != NULL || req->oldlen != 0)
2118 if (req->newptr == NULL)
2120 if (req->newlen < sizeof(addrs))
2122 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2126 switch (addrs[0].ss_family) {
2129 fin6 = (struct sockaddr_in6 *)&addrs[0];
2130 lin6 = (struct sockaddr_in6 *)&addrs[1];
2131 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2132 lin6->sin6_len != sizeof(struct sockaddr_in6))
2134 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2135 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2137 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2138 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2139 fin = (struct sockaddr_in *)&addrs[0];
2140 lin = (struct sockaddr_in *)&addrs[1];
2143 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2146 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2153 fin = (struct sockaddr_in *)&addrs[0];
2154 lin = (struct sockaddr_in *)&addrs[1];
2155 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2156 lin->sin_len != sizeof(struct sockaddr_in))
2163 INP_INFO_WLOCK(&V_tcbinfo);
2164 switch (addrs[0].ss_family) {
2167 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2168 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2169 INPLOOKUP_WLOCKPCB, NULL);
2174 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2175 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2180 if (inp->inp_flags & INP_TIMEWAIT) {
2182 * XXXRW: There currently exists a state where an
2183 * inpcb is present, but its timewait state has been
2184 * discarded. For now, don't allow dropping of this
2192 } else if (!(inp->inp_flags & INP_DROPPED) &&
2193 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2194 tp = intotcpcb(inp);
2195 tp = tcp_drop(tp, ECONNABORTED);
2202 INP_INFO_WUNLOCK(&V_tcbinfo);
2206 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2207 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2208 0, sysctl_drop, "", "Drop TCP connection");
2211 * Generate a standardized TCP log line for use throughout the
2212 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2213 * allow use in the interrupt context.
2215 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2216 * NB: The function may return NULL if memory allocation failed.
2218 * Due to header inclusion and ordering limitations the struct ip
2219 * and ip6_hdr pointers have to be passed as void pointers.
2222 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2226 /* Is logging enabled? */
2227 if (tcp_log_in_vain == 0)
2230 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2234 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2238 /* Is logging enabled? */
2239 if (tcp_log_debug == 0)
2242 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2246 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2253 const struct ip6_hdr *ip6;
2255 ip6 = (const struct ip6_hdr *)ip6hdr;
2257 ip = (struct ip *)ip4hdr;
2260 * The log line looks like this:
2261 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2263 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2264 sizeof(PRINT_TH_FLAGS) + 1 +
2266 2 * INET6_ADDRSTRLEN;
2268 2 * INET_ADDRSTRLEN;
2271 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2275 strcat(s, "TCP: [");
2278 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2279 inet_ntoa_r(inc->inc_faddr, sp);
2281 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2283 inet_ntoa_r(inc->inc_laddr, sp);
2285 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2288 ip6_sprintf(sp, &inc->inc6_faddr);
2290 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2292 ip6_sprintf(sp, &inc->inc6_laddr);
2294 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2295 } else if (ip6 && th) {
2296 ip6_sprintf(sp, &ip6->ip6_src);
2298 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2300 ip6_sprintf(sp, &ip6->ip6_dst);
2302 sprintf(sp, "]:%i", ntohs(th->th_dport));
2305 } else if (ip && th) {
2306 inet_ntoa_r(ip->ip_src, sp);
2308 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2310 inet_ntoa_r(ip->ip_dst, sp);
2312 sprintf(sp, "]:%i", ntohs(th->th_dport));
2320 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2321 if (*(s + size - 1) != '\0')
2322 panic("%s: string too long", __func__);