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 "Minmum 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 0
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");
286 * Take a value and get the next power of 2 that doesn't overflow.
287 * Used to size the tcp_inpcb hash buckets.
290 maketcp_hashsize(int size)
296 * get the next power of 2 higher than maxsockets.
298 hashsize = 1 << fls(size);
299 /* catch overflow, and just go one power of 2 smaller */
300 if (hashsize < size) {
301 hashsize = 1 << (fls(size) - 1);
309 const char *tcbhash_tuneable;
312 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
314 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
315 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
316 printf("%s: WARNING: unable to register helper hook\n", __func__);
317 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
318 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
319 printf("%s: WARNING: unable to register helper hook\n", __func__);
321 hashsize = TCBHASHSIZE;
322 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
325 * Auto tune the hash size based on maxsockets.
326 * A perfect hash would have a 1:1 mapping
327 * (hashsize = maxsockets) however it's been
328 * suggested that O(2) average is better.
330 hashsize = maketcp_hashsize(maxsockets / 4);
332 * Our historical default is 512,
333 * do not autotune lower than this.
338 printf("%s: %s auto tuned to %d\n", __func__,
339 tcbhash_tuneable, hashsize);
342 * We require a hashsize to be a power of two.
343 * Previously if it was not a power of two we would just reset it
344 * back to 512, which could be a nasty surprise if you did not notice
346 * Instead what we do is clip it to the closest power of two lower
347 * than the specified hash value.
349 if (!powerof2(hashsize)) {
350 int oldhashsize = hashsize;
352 hashsize = maketcp_hashsize(hashsize);
353 /* prevent absurdly low value */
356 printf("%s: WARNING: TCB hash size not a power of 2, "
357 "clipped from %d to %d.\n", __func__, oldhashsize,
360 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
361 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
362 IPI_HASHFIELDS_4TUPLE);
365 * These have to be type stable for the benefit of the timers.
367 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
368 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
369 uma_zone_set_max(V_tcpcb_zone, maxsockets);
376 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
377 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
378 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
380 /* Skip initialization of globals for non-default instances. */
381 if (!IS_DEFAULT_VNET(curvnet))
384 /* XXX virtualize those bellow? */
385 tcp_delacktime = TCPTV_DELACK;
386 tcp_keepinit = TCPTV_KEEP_INIT;
387 tcp_keepidle = TCPTV_KEEP_IDLE;
388 tcp_keepintvl = TCPTV_KEEPINTVL;
389 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
391 tcp_rexmit_min = TCPTV_MIN;
392 if (tcp_rexmit_min < 1)
394 tcp_rexmit_slop = TCPTV_CPU_VAR;
395 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
396 tcp_tcbhashsize = hashsize;
398 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
399 if (tcp_soreceive_stream) {
401 tcp_usrreqs.pru_soreceive = soreceive_stream;
404 tcp6_usrreqs.pru_soreceive = soreceive_stream;
409 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
411 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
413 if (max_protohdr < TCP_MINPROTOHDR)
414 max_protohdr = TCP_MINPROTOHDR;
415 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
417 #undef TCP_MINPROTOHDR
420 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
421 SHUTDOWN_PRI_DEFAULT);
422 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
423 EVENTHANDLER_PRI_ANY);
435 in_pcbinfo_destroy(&V_tcbinfo);
436 uma_zdestroy(V_sack_hole_zone);
437 uma_zdestroy(V_tcpcb_zone);
448 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
449 * tcp_template used to store this data in mbufs, but we now recopy it out
450 * of the tcpcb each time to conserve mbufs.
453 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
455 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
457 INP_WLOCK_ASSERT(inp);
460 if ((inp->inp_vflag & INP_IPV6) != 0) {
463 ip6 = (struct ip6_hdr *)ip_ptr;
464 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
465 (inp->inp_flow & IPV6_FLOWINFO_MASK);
466 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
467 (IPV6_VERSION & IPV6_VERSION_MASK);
468 ip6->ip6_nxt = IPPROTO_TCP;
469 ip6->ip6_plen = htons(sizeof(struct tcphdr));
470 ip6->ip6_src = inp->in6p_laddr;
471 ip6->ip6_dst = inp->in6p_faddr;
474 #if defined(INET6) && defined(INET)
481 ip = (struct ip *)ip_ptr;
482 ip->ip_v = IPVERSION;
484 ip->ip_tos = inp->inp_ip_tos;
488 ip->ip_ttl = inp->inp_ip_ttl;
490 ip->ip_p = IPPROTO_TCP;
491 ip->ip_src = inp->inp_laddr;
492 ip->ip_dst = inp->inp_faddr;
495 th->th_sport = inp->inp_lport;
496 th->th_dport = inp->inp_fport;
504 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
508 * Create template to be used to send tcp packets on a connection.
509 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
510 * use for this function is in keepalives, which use tcp_respond.
513 tcpip_maketemplate(struct inpcb *inp)
517 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
520 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
525 * Send a single message to the TCP at address specified by
526 * the given TCP/IP header. If m == NULL, then we make a copy
527 * of the tcpiphdr at ti and send directly to the addressed host.
528 * This is used to force keep alive messages out using the TCP
529 * template for a connection. If flags are given then we send
530 * a message back to the TCP which originated the * segment ti,
531 * and discard the mbuf containing it and any other attached mbufs.
533 * In any case the ack and sequence number of the transmitted
534 * segment are as specified by the parameters.
536 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
539 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
540 tcp_seq ack, tcp_seq seq, int flags)
553 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
556 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
563 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
564 INP_WLOCK_ASSERT(inp);
569 if (!(flags & TH_RST)) {
570 win = sbspace(&inp->inp_socket->so_rcv);
571 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
572 win = (long)TCP_MAXWIN << tp->rcv_scale;
576 m = m_gethdr(M_DONTWAIT, MT_DATA);
580 m->m_data += max_linkhdr;
583 bcopy((caddr_t)ip6, mtod(m, caddr_t),
584 sizeof(struct ip6_hdr));
585 ip6 = mtod(m, struct ip6_hdr *);
586 nth = (struct tcphdr *)(ip6 + 1);
590 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
591 ip = mtod(m, struct ip *);
592 nth = (struct tcphdr *)(ip + 1);
594 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
599 * XXX MRT We inherrit the FIB, which is lucky.
603 m->m_data = (caddr_t)ipgen;
604 /* m_len is set later */
606 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
609 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
610 nth = (struct tcphdr *)(ip6 + 1);
614 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
615 nth = (struct tcphdr *)(ip + 1);
619 * this is usually a case when an extension header
620 * exists between the IPv6 header and the
623 nth->th_sport = th->th_sport;
624 nth->th_dport = th->th_dport;
626 xchg(nth->th_dport, nth->th_sport, uint16_t);
632 ip6->ip6_vfc = IPV6_VERSION;
633 ip6->ip6_nxt = IPPROTO_TCP;
634 ip6->ip6_plen = 0; /* Set in ip6_output(). */
635 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
638 #if defined(INET) && defined(INET6)
643 tlen += sizeof (struct tcpiphdr);
644 ip->ip_len = htons(tlen);
645 ip->ip_ttl = V_ip_defttl;
646 if (V_path_mtu_discovery)
647 ip->ip_off |= htons(IP_DF);
651 m->m_pkthdr.len = tlen;
652 m->m_pkthdr.rcvif = NULL;
656 * Packet is associated with a socket, so allow the
657 * label of the response to reflect the socket label.
659 INP_WLOCK_ASSERT(inp);
660 mac_inpcb_create_mbuf(inp, m);
663 * Packet is not associated with a socket, so possibly
664 * update the label in place.
666 mac_netinet_tcp_reply(m);
669 nth->th_seq = htonl(seq);
670 nth->th_ack = htonl(ack);
672 nth->th_off = sizeof (struct tcphdr) >> 2;
673 nth->th_flags = flags;
675 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
677 nth->th_win = htons((u_short)win);
680 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
683 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
684 nth->th_sum = in6_cksum_pseudo(ip6,
685 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
686 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
690 #if defined(INET6) && defined(INET)
695 m->m_pkthdr.csum_flags = CSUM_TCP;
696 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
697 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
701 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
702 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
706 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
708 #if defined(INET) && defined(INET6)
712 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
717 * Create a new TCP control block, making an
718 * empty reassembly queue and hooking it to the argument
719 * protocol control block. The `inp' parameter must have
720 * come from the zone allocator set up in tcp_init().
723 tcp_newtcpcb(struct inpcb *inp)
725 struct tcpcb_mem *tm;
728 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
731 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
736 /* Initialise cc_var struct for this tcpcb. */
738 tp->ccv->type = IPPROTO_TCP;
739 tp->ccv->ccvc.tcp = tp;
742 * Use the current system default CC algorithm.
745 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
746 CC_ALGO(tp) = CC_DEFAULT();
749 if (CC_ALGO(tp)->cb_init != NULL)
750 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
751 uma_zfree(V_tcpcb_zone, tm);
756 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
757 uma_zfree(V_tcpcb_zone, tm);
762 tp->t_vnet = inp->inp_vnet;
764 tp->t_timers = &tm->tt;
765 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
766 tp->t_maxseg = tp->t_maxopd =
768 isipv6 ? V_tcp_v6mssdflt :
772 /* Set up our timeouts. */
773 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
774 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
775 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
776 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
777 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
779 if (V_tcp_do_rfc1323)
780 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
782 tp->t_flags |= TF_SACK_PERMIT;
783 TAILQ_INIT(&tp->snd_holes);
784 tp->t_inpcb = inp; /* XXX */
786 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
787 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
788 * reasonable initial retransmit time.
790 tp->t_srtt = TCPTV_SRTTBASE;
791 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
792 tp->t_rttmin = tcp_rexmit_min;
793 tp->t_rxtcur = TCPTV_RTOBASE;
794 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
795 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
796 tp->t_rcvtime = ticks;
798 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
799 * because the socket may be bound to an IPv6 wildcard address,
800 * which may match an IPv4-mapped IPv6 address.
802 inp->inp_ip_ttl = V_ip_defttl;
804 return (tp); /* XXX */
808 * Switch the congestion control algorithm back to NewReno for any active
809 * control blocks using an algorithm which is about to go away.
810 * This ensures the CC framework can allow the unload to proceed without leaving
811 * any dangling pointers which would trigger a panic.
812 * Returning non-zero would inform the CC framework that something went wrong
813 * and it would be unsafe to allow the unload to proceed. However, there is no
814 * way for this to occur with this implementation so we always return zero.
817 tcp_ccalgounload(struct cc_algo *unload_algo)
819 struct cc_algo *tmpalgo;
822 VNET_ITERATOR_DECL(vnet_iter);
825 * Check all active control blocks across all network stacks and change
826 * any that are using "unload_algo" back to NewReno. If "unload_algo"
827 * requires cleanup code to be run, call it.
830 VNET_FOREACH(vnet_iter) {
831 CURVNET_SET(vnet_iter);
832 INP_INFO_RLOCK(&V_tcbinfo);
834 * New connections already part way through being initialised
835 * with the CC algo we're removing will not race with this code
836 * because the INP_INFO_WLOCK is held during initialisation. We
837 * therefore don't enter the loop below until the connection
838 * list has stabilised.
840 LIST_FOREACH(inp, &V_tcb, inp_list) {
842 /* Important to skip tcptw structs. */
843 if (!(inp->inp_flags & INP_TIMEWAIT) &&
844 (tp = intotcpcb(inp)) != NULL) {
846 * By holding INP_WLOCK here, we are assured
847 * that the connection is not currently
848 * executing inside the CC module's functions
849 * i.e. it is safe to make the switch back to
852 if (CC_ALGO(tp) == unload_algo) {
853 tmpalgo = CC_ALGO(tp);
854 /* NewReno does not require any init. */
855 CC_ALGO(tp) = &newreno_cc_algo;
856 if (tmpalgo->cb_destroy != NULL)
857 tmpalgo->cb_destroy(tp->ccv);
862 INP_INFO_RUNLOCK(&V_tcbinfo);
871 * Drop a TCP connection, reporting
872 * the specified error. If connection is synchronized,
873 * then send a RST to peer.
876 tcp_drop(struct tcpcb *tp, int errno)
878 struct socket *so = tp->t_inpcb->inp_socket;
880 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
881 INP_WLOCK_ASSERT(tp->t_inpcb);
883 if (TCPS_HAVERCVDSYN(tp->t_state)) {
884 tp->t_state = TCPS_CLOSED;
885 (void) tcp_output(tp);
886 TCPSTAT_INC(tcps_drops);
888 TCPSTAT_INC(tcps_conndrops);
889 if (errno == ETIMEDOUT && tp->t_softerror)
890 errno = tp->t_softerror;
891 so->so_error = errno;
892 return (tcp_close(tp));
896 tcp_discardcb(struct tcpcb *tp)
898 struct inpcb *inp = tp->t_inpcb;
899 struct socket *so = inp->inp_socket;
901 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
904 INP_WLOCK_ASSERT(inp);
907 * Make sure that all of our timers are stopped before we delete the
910 * XXXRW: Really, we would like to use callout_drain() here in order
911 * to avoid races experienced in tcp_timer.c where a timer is already
912 * executing at this point. However, we can't, both because we're
913 * running in a context where we can't sleep, and also because we
914 * hold locks required by the timers. What we instead need to do is
915 * test to see if callout_drain() is required, and if so, defer some
916 * portion of the remainder of tcp_discardcb() to an asynchronous
917 * context that can callout_drain() and then continue. Some care
918 * will be required to ensure that no further processing takes place
919 * on the tcpcb, even though it hasn't been freed (a flag?).
921 callout_stop(&tp->t_timers->tt_rexmt);
922 callout_stop(&tp->t_timers->tt_persist);
923 callout_stop(&tp->t_timers->tt_keep);
924 callout_stop(&tp->t_timers->tt_2msl);
925 callout_stop(&tp->t_timers->tt_delack);
928 * If we got enough samples through the srtt filter,
929 * save the rtt and rttvar in the routing entry.
930 * 'Enough' is arbitrarily defined as 4 rtt samples.
931 * 4 samples is enough for the srtt filter to converge
932 * to within enough % of the correct value; fewer samples
933 * and we could save a bogus rtt. The danger is not high
934 * as tcp quickly recovers from everything.
935 * XXX: Works very well but needs some more statistics!
937 if (tp->t_rttupdated >= 4) {
938 struct hc_metrics_lite metrics;
941 bzero(&metrics, sizeof(metrics));
943 * Update the ssthresh always when the conditions below
944 * are satisfied. This gives us better new start value
945 * for the congestion avoidance for new connections.
946 * ssthresh is only set if packet loss occured on a session.
948 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
949 * being torn down. Ideally this code would not use 'so'.
951 ssthresh = tp->snd_ssthresh;
952 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
954 * convert the limit from user data bytes to
955 * packets then to packet data bytes.
957 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
960 ssthresh *= (u_long)(tp->t_maxseg +
962 (isipv6 ? sizeof (struct ip6_hdr) +
963 sizeof (struct tcphdr) :
965 sizeof (struct tcpiphdr)
972 metrics.rmx_ssthresh = ssthresh;
974 metrics.rmx_rtt = tp->t_srtt;
975 metrics.rmx_rttvar = tp->t_rttvar;
976 metrics.rmx_cwnd = tp->snd_cwnd;
977 metrics.rmx_sendpipe = 0;
978 metrics.rmx_recvpipe = 0;
980 tcp_hc_update(&inp->inp_inc, &metrics);
983 /* free the reassembly queue, if any */
987 /* Disconnect offload device, if any. */
988 if (tp->t_flags & TF_TOE)
989 tcp_offload_detach(tp);
992 tcp_free_sackholes(tp);
994 /* Allow the CC algorithm to clean up after itself. */
995 if (CC_ALGO(tp)->cb_destroy != NULL)
996 CC_ALGO(tp)->cb_destroy(tp->ccv);
998 khelp_destroy_osd(tp->osd);
1001 inp->inp_ppcb = NULL;
1003 uma_zfree(V_tcpcb_zone, tp);
1007 * Attempt to close a TCP control block, marking it as dropped, and freeing
1008 * the socket if we hold the only reference.
1011 tcp_close(struct tcpcb *tp)
1013 struct inpcb *inp = tp->t_inpcb;
1016 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1017 INP_WLOCK_ASSERT(inp);
1020 if (tp->t_state == TCPS_LISTEN)
1021 tcp_offload_listen_stop(tp);
1024 TCPSTAT_INC(tcps_closed);
1025 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1026 so = inp->inp_socket;
1027 soisdisconnected(so);
1028 if (inp->inp_flags & INP_SOCKREF) {
1029 KASSERT(so->so_state & SS_PROTOREF,
1030 ("tcp_close: !SS_PROTOREF"));
1031 inp->inp_flags &= ~INP_SOCKREF;
1035 so->so_state &= ~SS_PROTOREF;
1045 VNET_ITERATOR_DECL(vnet_iter);
1050 VNET_LIST_RLOCK_NOSLEEP();
1051 VNET_FOREACH(vnet_iter) {
1052 CURVNET_SET(vnet_iter);
1057 * Walk the tcpbs, if existing, and flush the reassembly queue,
1058 * if there is one...
1059 * XXX: The "Net/3" implementation doesn't imply that the TCP
1060 * reassembly queue should be flushed, but in a situation
1061 * where we're really low on mbufs, this is potentially
1064 INP_INFO_RLOCK(&V_tcbinfo);
1065 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1066 if (inpb->inp_flags & INP_TIMEWAIT)
1069 if ((tcpb = intotcpcb(inpb)) != NULL) {
1070 tcp_reass_flush(tcpb);
1071 tcp_clean_sackreport(tcpb);
1075 INP_INFO_RUNLOCK(&V_tcbinfo);
1078 VNET_LIST_RUNLOCK_NOSLEEP();
1082 * Notify a tcp user of an asynchronous error;
1083 * store error as soft error, but wake up user
1084 * (for now, won't do anything until can select for soft error).
1086 * Do not wake up user since there currently is no mechanism for
1087 * reporting soft errors (yet - a kqueue filter may be added).
1089 static struct inpcb *
1090 tcp_notify(struct inpcb *inp, int error)
1094 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1095 INP_WLOCK_ASSERT(inp);
1097 if ((inp->inp_flags & INP_TIMEWAIT) ||
1098 (inp->inp_flags & INP_DROPPED))
1101 tp = intotcpcb(inp);
1102 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1105 * Ignore some errors if we are hooked up.
1106 * If connection hasn't completed, has retransmitted several times,
1107 * and receives a second error, give up now. This is better
1108 * than waiting a long time to establish a connection that
1109 * can never complete.
1111 if (tp->t_state == TCPS_ESTABLISHED &&
1112 (error == EHOSTUNREACH || error == ENETUNREACH ||
1113 error == EHOSTDOWN)) {
1115 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1117 tp = tcp_drop(tp, error);
1123 tp->t_softerror = error;
1127 wakeup( &so->so_timeo);
1134 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1136 int error, i, m, n, pcb_count;
1137 struct inpcb *inp, **inp_list;
1142 * The process of preparing the TCB list is too time-consuming and
1143 * resource-intensive to repeat twice on every request.
1145 if (req->oldptr == NULL) {
1146 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1147 n += imax(n / 8, 10);
1148 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1152 if (req->newptr != NULL)
1156 * OK, now we're committed to doing something.
1158 INP_INFO_RLOCK(&V_tcbinfo);
1159 gencnt = V_tcbinfo.ipi_gencnt;
1160 n = V_tcbinfo.ipi_count;
1161 INP_INFO_RUNLOCK(&V_tcbinfo);
1163 m = syncache_pcbcount();
1165 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1166 + (n + m) * sizeof(struct xtcpcb));
1170 xig.xig_len = sizeof xig;
1171 xig.xig_count = n + m;
1172 xig.xig_gen = gencnt;
1173 xig.xig_sogen = so_gencnt;
1174 error = SYSCTL_OUT(req, &xig, sizeof xig);
1178 error = syncache_pcblist(req, m, &pcb_count);
1182 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1183 if (inp_list == NULL)
1186 INP_INFO_RLOCK(&V_tcbinfo);
1187 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1188 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1190 if (inp->inp_gencnt <= gencnt) {
1192 * XXX: This use of cr_cansee(), introduced with
1193 * TCP state changes, is not quite right, but for
1194 * now, better than nothing.
1196 if (inp->inp_flags & INP_TIMEWAIT) {
1197 if (intotw(inp) != NULL)
1198 error = cr_cansee(req->td->td_ucred,
1199 intotw(inp)->tw_cred);
1201 error = EINVAL; /* Skip this inp. */
1203 error = cr_canseeinpcb(req->td->td_ucred, inp);
1206 inp_list[i++] = inp;
1211 INP_INFO_RUNLOCK(&V_tcbinfo);
1215 for (i = 0; i < n; i++) {
1218 if (inp->inp_gencnt <= gencnt) {
1222 bzero(&xt, sizeof(xt));
1223 xt.xt_len = sizeof xt;
1224 /* XXX should avoid extra copy */
1225 bcopy(inp, &xt.xt_inp, sizeof *inp);
1226 inp_ppcb = inp->inp_ppcb;
1227 if (inp_ppcb == NULL)
1228 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1229 else if (inp->inp_flags & INP_TIMEWAIT) {
1230 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1231 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1233 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1234 if (xt.xt_tp.t_timers)
1235 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1237 if (inp->inp_socket != NULL)
1238 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1240 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1241 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1243 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1245 error = SYSCTL_OUT(req, &xt, sizeof xt);
1249 INP_INFO_WLOCK(&V_tcbinfo);
1250 for (i = 0; i < n; i++) {
1253 if (!in_pcbrele_rlocked(inp))
1256 INP_INFO_WUNLOCK(&V_tcbinfo);
1260 * Give the user an updated idea of our state.
1261 * If the generation differs from what we told
1262 * her before, she knows that something happened
1263 * while we were processing this request, and it
1264 * might be necessary to retry.
1266 INP_INFO_RLOCK(&V_tcbinfo);
1267 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1268 xig.xig_sogen = so_gencnt;
1269 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1270 INP_INFO_RUNLOCK(&V_tcbinfo);
1271 error = SYSCTL_OUT(req, &xig, sizeof xig);
1273 free(inp_list, M_TEMP);
1277 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1278 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1279 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1283 tcp_getcred(SYSCTL_HANDLER_ARGS)
1286 struct sockaddr_in addrs[2];
1290 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1293 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1296 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1297 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1299 if (inp->inp_socket == NULL)
1302 error = cr_canseeinpcb(req->td->td_ucred, inp);
1304 cru2x(inp->inp_cred, &xuc);
1309 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1313 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1314 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1315 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1320 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1323 struct sockaddr_in6 addrs[2];
1330 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1333 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1336 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1337 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1340 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1342 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1351 inp = in_pcblookup(&V_tcbinfo,
1352 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1354 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1355 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1358 inp = in6_pcblookup(&V_tcbinfo,
1359 &addrs[1].sin6_addr, addrs[1].sin6_port,
1360 &addrs[0].sin6_addr, addrs[0].sin6_port,
1361 INPLOOKUP_RLOCKPCB, NULL);
1363 if (inp->inp_socket == NULL)
1366 error = cr_canseeinpcb(req->td->td_ucred, inp);
1368 cru2x(inp->inp_cred, &xuc);
1373 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1377 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1378 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1379 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1385 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1387 struct ip *ip = vip;
1389 struct in_addr faddr;
1392 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1394 struct in_conninfo inc;
1395 tcp_seq icmp_tcp_seq;
1398 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1399 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1402 if (cmd == PRC_MSGSIZE)
1403 notify = tcp_mtudisc_notify;
1404 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1405 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1406 notify = tcp_drop_syn_sent;
1408 * Redirects don't need to be handled up here.
1410 else if (PRC_IS_REDIRECT(cmd))
1413 * Source quench is depreciated.
1415 else if (cmd == PRC_QUENCH)
1418 * Hostdead is ugly because it goes linearly through all PCBs.
1419 * XXX: We never get this from ICMP, otherwise it makes an
1420 * excellent DoS attack on machines with many connections.
1422 else if (cmd == PRC_HOSTDEAD)
1424 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1427 icp = (struct icmp *)((caddr_t)ip
1428 - offsetof(struct icmp, icmp_ip));
1429 th = (struct tcphdr *)((caddr_t)ip
1430 + (ip->ip_hl << 2));
1431 INP_INFO_WLOCK(&V_tcbinfo);
1432 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1433 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1435 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1436 !(inp->inp_flags & INP_DROPPED) &&
1437 !(inp->inp_socket == NULL)) {
1438 icmp_tcp_seq = htonl(th->th_seq);
1439 tp = intotcpcb(inp);
1440 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1441 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1442 if (cmd == PRC_MSGSIZE) {
1445 * If we got a needfrag set the MTU
1446 * in the route to the suggested new
1447 * value (if given) and then notify.
1449 bzero(&inc, sizeof(inc));
1450 inc.inc_faddr = faddr;
1452 inp->inp_inc.inc_fibnum;
1454 mtu = ntohs(icp->icmp_nextmtu);
1456 * If no alternative MTU was
1457 * proposed, try the next smaller
1462 ntohs(ip->ip_len), 1);
1463 if (mtu < V_tcp_minmss
1464 + sizeof(struct tcpiphdr))
1466 + sizeof(struct tcpiphdr);
1468 * Only cache the MTU if it
1469 * is smaller than the interface
1470 * or route MTU. tcp_mtudisc()
1471 * will do right thing by itself.
1473 if (mtu <= tcp_maxmtu(&inc, NULL))
1474 tcp_hc_updatemtu(&inc, mtu);
1475 tcp_mtudisc(inp, mtu);
1477 inp = (*notify)(inp,
1478 inetctlerrmap[cmd]);
1484 bzero(&inc, sizeof(inc));
1485 inc.inc_fport = th->th_dport;
1486 inc.inc_lport = th->th_sport;
1487 inc.inc_faddr = faddr;
1488 inc.inc_laddr = ip->ip_src;
1489 syncache_unreach(&inc, th);
1491 INP_INFO_WUNLOCK(&V_tcbinfo);
1493 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1499 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1502 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1503 struct ip6_hdr *ip6;
1505 struct ip6ctlparam *ip6cp = NULL;
1506 const struct sockaddr_in6 *sa6_src = NULL;
1508 struct tcp_portonly {
1513 if (sa->sa_family != AF_INET6 ||
1514 sa->sa_len != sizeof(struct sockaddr_in6))
1517 if (cmd == PRC_MSGSIZE)
1518 notify = tcp_mtudisc_notify;
1519 else if (!PRC_IS_REDIRECT(cmd) &&
1520 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1522 /* Source quench is depreciated. */
1523 else if (cmd == PRC_QUENCH)
1526 /* if the parameter is from icmp6, decode it. */
1528 ip6cp = (struct ip6ctlparam *)d;
1530 ip6 = ip6cp->ip6c_ip6;
1531 off = ip6cp->ip6c_off;
1532 sa6_src = ip6cp->ip6c_src;
1536 off = 0; /* fool gcc */
1541 struct in_conninfo inc;
1543 * XXX: We assume that when IPV6 is non NULL,
1544 * M and OFF are valid.
1547 /* check if we can safely examine src and dst ports */
1548 if (m->m_pkthdr.len < off + sizeof(*thp))
1551 bzero(&th, sizeof(th));
1552 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1554 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1555 (struct sockaddr *)ip6cp->ip6c_src,
1556 th.th_sport, cmd, NULL, notify);
1558 bzero(&inc, sizeof(inc));
1559 inc.inc_fport = th.th_dport;
1560 inc.inc_lport = th.th_sport;
1561 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1562 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1563 inc.inc_flags |= INC_ISIPV6;
1564 INP_INFO_WLOCK(&V_tcbinfo);
1565 syncache_unreach(&inc, &th);
1566 INP_INFO_WUNLOCK(&V_tcbinfo);
1568 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1569 0, cmd, NULL, notify);
1575 * Following is where TCP initial sequence number generation occurs.
1577 * There are two places where we must use initial sequence numbers:
1578 * 1. In SYN-ACK packets.
1579 * 2. In SYN packets.
1581 * All ISNs for SYN-ACK packets are generated by the syncache. See
1582 * tcp_syncache.c for details.
1584 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1585 * depends on this property. In addition, these ISNs should be
1586 * unguessable so as to prevent connection hijacking. To satisfy
1587 * the requirements of this situation, the algorithm outlined in
1588 * RFC 1948 is used, with only small modifications.
1590 * Implementation details:
1592 * Time is based off the system timer, and is corrected so that it
1593 * increases by one megabyte per second. This allows for proper
1594 * recycling on high speed LANs while still leaving over an hour
1597 * As reading the *exact* system time is too expensive to be done
1598 * whenever setting up a TCP connection, we increment the time
1599 * offset in two ways. First, a small random positive increment
1600 * is added to isn_offset for each connection that is set up.
1601 * Second, the function tcp_isn_tick fires once per clock tick
1602 * and increments isn_offset as necessary so that sequence numbers
1603 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1604 * random positive increments serve only to ensure that the same
1605 * exact sequence number is never sent out twice (as could otherwise
1606 * happen when a port is recycled in less than the system tick
1609 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1610 * between seeding of isn_secret. This is normally set to zero,
1611 * as reseeding should not be necessary.
1613 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1614 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1615 * general, this means holding an exclusive (write) lock.
1618 #define ISN_BYTES_PER_SECOND 1048576
1619 #define ISN_STATIC_INCREMENT 4096
1620 #define ISN_RANDOM_INCREMENT (4096 - 1)
1622 static VNET_DEFINE(u_char, isn_secret[32]);
1623 static VNET_DEFINE(int, isn_last);
1624 static VNET_DEFINE(int, isn_last_reseed);
1625 static VNET_DEFINE(u_int32_t, isn_offset);
1626 static VNET_DEFINE(u_int32_t, isn_offset_old);
1628 #define V_isn_secret VNET(isn_secret)
1629 #define V_isn_last VNET(isn_last)
1630 #define V_isn_last_reseed VNET(isn_last_reseed)
1631 #define V_isn_offset VNET(isn_offset)
1632 #define V_isn_offset_old VNET(isn_offset_old)
1635 tcp_new_isn(struct tcpcb *tp)
1638 u_int32_t md5_buffer[4];
1640 u_int32_t projected_offset;
1642 INP_WLOCK_ASSERT(tp->t_inpcb);
1645 /* Seed if this is the first use, reseed if requested. */
1646 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1647 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1649 read_random(&V_isn_secret, sizeof(V_isn_secret));
1650 V_isn_last_reseed = ticks;
1653 /* Compute the md5 hash and return the ISN. */
1655 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1656 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1658 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1659 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1660 sizeof(struct in6_addr));
1661 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1662 sizeof(struct in6_addr));
1666 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1667 sizeof(struct in_addr));
1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1669 sizeof(struct in_addr));
1671 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1672 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1673 new_isn = (tcp_seq) md5_buffer[0];
1674 V_isn_offset += ISN_STATIC_INCREMENT +
1675 (arc4random() & ISN_RANDOM_INCREMENT);
1676 if (ticks != V_isn_last) {
1677 projected_offset = V_isn_offset_old +
1678 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1679 if (SEQ_GT(projected_offset, V_isn_offset))
1680 V_isn_offset = projected_offset;
1681 V_isn_offset_old = V_isn_offset;
1684 new_isn += V_isn_offset;
1690 * When a specific ICMP unreachable message is received and the
1691 * connection state is SYN-SENT, drop the connection. This behavior
1692 * is controlled by the icmp_may_rst sysctl.
1695 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1699 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1700 INP_WLOCK_ASSERT(inp);
1702 if ((inp->inp_flags & INP_TIMEWAIT) ||
1703 (inp->inp_flags & INP_DROPPED))
1706 tp = intotcpcb(inp);
1707 if (tp->t_state != TCPS_SYN_SENT)
1710 tp = tcp_drop(tp, errno);
1718 * When `need fragmentation' ICMP is received, update our idea of the MSS
1719 * based on the new value. Also nudge TCP to send something, since we
1720 * know the packet we just sent was dropped.
1721 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1723 static struct inpcb *
1724 tcp_mtudisc_notify(struct inpcb *inp, int error)
1727 return (tcp_mtudisc(inp, -1));
1731 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1736 INP_WLOCK_ASSERT(inp);
1737 if ((inp->inp_flags & INP_TIMEWAIT) ||
1738 (inp->inp_flags & INP_DROPPED))
1741 tp = intotcpcb(inp);
1742 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1744 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1746 so = inp->inp_socket;
1747 SOCKBUF_LOCK(&so->so_snd);
1748 /* If the mss is larger than the socket buffer, decrease the mss. */
1749 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1750 tp->t_maxseg = so->so_snd.sb_hiwat;
1751 SOCKBUF_UNLOCK(&so->so_snd);
1753 TCPSTAT_INC(tcps_mturesent);
1755 tp->snd_nxt = tp->snd_una;
1756 tcp_free_sackholes(tp);
1757 tp->snd_recover = tp->snd_max;
1758 if (tp->t_flags & TF_SACK_PERMIT)
1759 EXIT_FASTRECOVERY(tp->t_flags);
1766 * Look-up the routing entry to the peer of this inpcb. If no route
1767 * is found and it cannot be allocated, then return 0. This routine
1768 * is called by TCP routines that access the rmx structure and by
1769 * tcp_mss_update to get the peer/interface MTU.
1772 tcp_maxmtu(struct in_conninfo *inc, int *flags)
1775 struct sockaddr_in *dst;
1779 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1781 bzero(&sro, sizeof(sro));
1782 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1783 dst = (struct sockaddr_in *)&sro.ro_dst;
1784 dst->sin_family = AF_INET;
1785 dst->sin_len = sizeof(*dst);
1786 dst->sin_addr = inc->inc_faddr;
1787 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1789 if (sro.ro_rt != NULL) {
1790 ifp = sro.ro_rt->rt_ifp;
1791 if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
1792 maxmtu = ifp->if_mtu;
1794 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
1796 /* Report additional interface capabilities. */
1797 if (flags != NULL) {
1798 if (ifp->if_capenable & IFCAP_TSO4 &&
1799 ifp->if_hwassist & CSUM_TSO)
1810 tcp_maxmtu6(struct in_conninfo *inc, int *flags)
1812 struct route_in6 sro6;
1816 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1818 bzero(&sro6, sizeof(sro6));
1819 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1820 sro6.ro_dst.sin6_family = AF_INET6;
1821 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1822 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1823 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1825 if (sro6.ro_rt != NULL) {
1826 ifp = sro6.ro_rt->rt_ifp;
1827 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
1828 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1830 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
1831 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1833 /* Report additional interface capabilities. */
1834 if (flags != NULL) {
1835 if (ifp->if_capenable & IFCAP_TSO6 &&
1836 ifp->if_hwassist & CSUM_TSO)
1847 /* compute ESP/AH header size for TCP, including outer IP header. */
1849 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1856 struct ip6_hdr *ip6;
1860 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1862 MGETHDR(m, M_DONTWAIT, MT_DATA);
1867 if ((inp->inp_vflag & INP_IPV6) != 0) {
1868 ip6 = mtod(m, struct ip6_hdr *);
1869 th = (struct tcphdr *)(ip6 + 1);
1870 m->m_pkthdr.len = m->m_len =
1871 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1872 tcpip_fillheaders(inp, ip6, th);
1873 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1877 ip = mtod(m, struct ip *);
1878 th = (struct tcphdr *)(ip + 1);
1879 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1880 tcpip_fillheaders(inp, ip, th);
1881 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1889 #ifdef TCP_SIGNATURE
1891 * Callback function invoked by m_apply() to digest TCP segment data
1892 * contained within an mbuf chain.
1895 tcp_signature_apply(void *fstate, void *data, u_int len)
1898 MD5Update(fstate, (u_char *)data, len);
1903 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1906 * m pointer to head of mbuf chain
1908 * len length of TCP segment data, excluding options
1909 * optlen length of TCP segment options
1910 * buf pointer to storage for computed MD5 digest
1911 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1913 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1914 * When called from tcp_input(), we can be sure that th_sum has been
1915 * zeroed out and verified already.
1917 * Return 0 if successful, otherwise return -1.
1919 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1920 * search with the destination IP address, and a 'magic SPI' to be
1921 * determined by the application. This is hardcoded elsewhere to 1179
1922 * right now. Another branch of this code exists which uses the SPD to
1923 * specify per-application flows but it is unstable.
1926 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1927 u_char *buf, u_int direction)
1929 union sockaddr_union dst;
1931 struct ippseudo ippseudo;
1937 struct ipovly *ipovly;
1939 struct secasvar *sav;
1942 struct ip6_hdr *ip6;
1943 struct in6_addr in6;
1944 char ip6buf[INET6_ADDRSTRLEN];
1950 KASSERT(m != NULL, ("NULL mbuf chain"));
1951 KASSERT(buf != NULL, ("NULL signature pointer"));
1953 /* Extract the destination from the IP header in the mbuf. */
1954 bzero(&dst, sizeof(union sockaddr_union));
1955 ip = mtod(m, struct ip *);
1957 ip6 = NULL; /* Make the compiler happy. */
1962 dst.sa.sa_len = sizeof(struct sockaddr_in);
1963 dst.sa.sa_family = AF_INET;
1964 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1965 ip->ip_src : ip->ip_dst;
1969 case (IPV6_VERSION >> 4):
1970 ip6 = mtod(m, struct ip6_hdr *);
1971 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1972 dst.sa.sa_family = AF_INET6;
1973 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1974 ip6->ip6_src : ip6->ip6_dst;
1983 /* Look up an SADB entry which matches the address of the peer. */
1984 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1986 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
1987 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
1989 (ip->ip_v == (IPV6_VERSION >> 4)) ?
1990 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
1998 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2000 * XXX The ippseudo header MUST be digested in network byte order,
2001 * or else we'll fail the regression test. Assume all fields we've
2002 * been doing arithmetic on have been in host byte order.
2003 * XXX One cannot depend on ipovly->ih_len here. When called from
2004 * tcp_output(), the underlying ip_len member has not yet been set.
2009 ipovly = (struct ipovly *)ip;
2010 ippseudo.ippseudo_src = ipovly->ih_src;
2011 ippseudo.ippseudo_dst = ipovly->ih_dst;
2012 ippseudo.ippseudo_pad = 0;
2013 ippseudo.ippseudo_p = IPPROTO_TCP;
2014 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2016 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2018 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2019 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2024 * RFC 2385, 2.0 Proposal
2025 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2026 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2027 * extended next header value (to form 32 bits), and 32-bit segment
2029 * Note: Upper-Layer Packet Length comes before Next Header.
2031 case (IPV6_VERSION >> 4):
2033 in6_clearscope(&in6);
2034 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2036 in6_clearscope(&in6);
2037 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2038 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2039 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2041 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2042 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2043 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2045 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2047 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2048 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2059 * Step 2: Update MD5 hash with TCP header, excluding options.
2060 * The TCP checksum must be set to zero.
2062 savecsum = th->th_sum;
2064 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2065 th->th_sum = savecsum;
2068 * Step 3: Update MD5 hash with TCP segment data.
2069 * Use m_apply() to avoid an early m_pullup().
2072 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2075 * Step 4: Update MD5 hash with shared secret.
2077 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2078 MD5Final(buf, &ctx);
2080 key_sa_recordxfer(sav, m);
2086 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2089 * m pointer to head of mbuf chain
2090 * len length of TCP segment data, excluding options
2091 * optlen length of TCP segment options
2092 * buf pointer to storage for computed MD5 digest
2093 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2095 * Return 1 if successful, otherwise return 0.
2098 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2099 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2101 char tmpdigest[TCP_SIGLEN];
2103 if (tcp_sig_checksigs == 0)
2105 if ((tcpbflag & TF_SIGNATURE) == 0) {
2106 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2109 * If this socket is not expecting signature but
2110 * the segment contains signature just fail.
2112 TCPSTAT_INC(tcps_sig_err_sigopt);
2113 TCPSTAT_INC(tcps_sig_rcvbadsig);
2117 /* Signature is not expected, and not present in segment. */
2122 * If this socket is expecting signature but the segment does not
2123 * contain any just fail.
2125 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2126 TCPSTAT_INC(tcps_sig_err_nosigopt);
2127 TCPSTAT_INC(tcps_sig_rcvbadsig);
2130 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2131 IPSEC_DIR_INBOUND) == -1) {
2132 TCPSTAT_INC(tcps_sig_err_buildsig);
2133 TCPSTAT_INC(tcps_sig_rcvbadsig);
2137 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2138 TCPSTAT_INC(tcps_sig_rcvbadsig);
2141 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2144 #endif /* TCP_SIGNATURE */
2147 sysctl_drop(SYSCTL_HANDLER_ARGS)
2149 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2150 struct sockaddr_storage addrs[2];
2154 struct sockaddr_in *fin, *lin;
2156 struct sockaddr_in6 *fin6, *lin6;
2167 if (req->oldptr != NULL || req->oldlen != 0)
2169 if (req->newptr == NULL)
2171 if (req->newlen < sizeof(addrs))
2173 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2177 switch (addrs[0].ss_family) {
2180 fin6 = (struct sockaddr_in6 *)&addrs[0];
2181 lin6 = (struct sockaddr_in6 *)&addrs[1];
2182 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2183 lin6->sin6_len != sizeof(struct sockaddr_in6))
2185 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2186 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2188 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2189 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2190 fin = (struct sockaddr_in *)&addrs[0];
2191 lin = (struct sockaddr_in *)&addrs[1];
2194 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2197 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2204 fin = (struct sockaddr_in *)&addrs[0];
2205 lin = (struct sockaddr_in *)&addrs[1];
2206 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2207 lin->sin_len != sizeof(struct sockaddr_in))
2214 INP_INFO_WLOCK(&V_tcbinfo);
2215 switch (addrs[0].ss_family) {
2218 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2219 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2220 INPLOOKUP_WLOCKPCB, NULL);
2225 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2226 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2231 if (inp->inp_flags & INP_TIMEWAIT) {
2233 * XXXRW: There currently exists a state where an
2234 * inpcb is present, but its timewait state has been
2235 * discarded. For now, don't allow dropping of this
2243 } else if (!(inp->inp_flags & INP_DROPPED) &&
2244 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2245 tp = intotcpcb(inp);
2246 tp = tcp_drop(tp, ECONNABORTED);
2253 INP_INFO_WUNLOCK(&V_tcbinfo);
2257 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2258 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2259 0, sysctl_drop, "", "Drop TCP connection");
2262 * Generate a standardized TCP log line for use throughout the
2263 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2264 * allow use in the interrupt context.
2266 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2267 * NB: The function may return NULL if memory allocation failed.
2269 * Due to header inclusion and ordering limitations the struct ip
2270 * and ip6_hdr pointers have to be passed as void pointers.
2273 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2277 /* Is logging enabled? */
2278 if (tcp_log_in_vain == 0)
2281 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2285 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2289 /* Is logging enabled? */
2290 if (tcp_log_debug == 0)
2293 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2297 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2304 const struct ip6_hdr *ip6;
2306 ip6 = (const struct ip6_hdr *)ip6hdr;
2308 ip = (struct ip *)ip4hdr;
2311 * The log line looks like this:
2312 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2314 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2315 sizeof(PRINT_TH_FLAGS) + 1 +
2317 2 * INET6_ADDRSTRLEN;
2319 2 * INET_ADDRSTRLEN;
2322 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2326 strcat(s, "TCP: [");
2329 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2330 inet_ntoa_r(inc->inc_faddr, sp);
2332 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2334 inet_ntoa_r(inc->inc_laddr, sp);
2336 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2339 ip6_sprintf(sp, &inc->inc6_faddr);
2341 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2343 ip6_sprintf(sp, &inc->inc6_laddr);
2345 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2346 } else if (ip6 && th) {
2347 ip6_sprintf(sp, &ip6->ip6_src);
2349 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2351 ip6_sprintf(sp, &ip6->ip6_dst);
2353 sprintf(sp, "]:%i", ntohs(th->th_dport));
2356 } else if (ip && th) {
2357 inet_ntoa_r(ip->ip_src, sp);
2359 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2361 inet_ntoa_r(ip->ip_dst, sp);
2363 sprintf(sp, "]:%i", ntohs(th->th_dport));
2371 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2372 if (*(s + size - 1) != '\0')
2373 panic("%s: string too long", __func__);