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_kdtrace.h"
40 #include "opt_tcpdebug.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/callout.h>
45 #include <sys/hhook.h>
46 #include <sys/kernel.h>
47 #include <sys/khelp.h>
48 #include <sys/sysctl.h>
50 #include <sys/malloc.h>
53 #include <sys/domain.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/protosw.h>
61 #include <sys/random.h>
65 #include <net/route.h>
69 #include <netinet/cc.h>
70 #include <netinet/in.h>
71 #include <netinet/in_kdtrace.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_systm.h>
74 #include <netinet/in_var.h>
75 #include <netinet/ip.h>
76 #include <netinet/ip_icmp.h>
77 #include <netinet/ip_var.h>
79 #include <netinet/ip6.h>
80 #include <netinet6/in6_pcb.h>
81 #include <netinet6/ip6_var.h>
82 #include <netinet6/scope6_var.h>
83 #include <netinet6/nd6.h>
86 #include <netinet/tcp_fsm.h>
87 #include <netinet/tcp_seq.h>
88 #include <netinet/tcp_timer.h>
89 #include <netinet/tcp_var.h>
90 #include <netinet/tcp_syncache.h>
92 #include <netinet6/tcp6_var.h>
94 #include <netinet/tcpip.h>
96 #include <netinet/tcp_debug.h>
99 #include <netinet6/ip6protosw.h>
102 #include <netinet/tcp_offload.h>
106 #include <netipsec/ipsec.h>
107 #include <netipsec/xform.h>
109 #include <netipsec/ipsec6.h>
111 #include <netipsec/key.h>
112 #include <sys/syslog.h>
115 #include <machine/in_cksum.h>
118 #include <security/mac/mac_framework.h>
120 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
122 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
126 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
131 error = sysctl_handle_int(oidp, &new, 0, req);
132 if (error == 0 && req->newptr) {
133 if (new < TCP_MINMSS)
141 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
142 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
143 &sysctl_net_inet_tcp_mss_check, "I",
144 "Default TCP Maximum Segment Size");
148 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
152 new = V_tcp_v6mssdflt;
153 error = sysctl_handle_int(oidp, &new, 0, req);
154 if (error == 0 && req->newptr) {
155 if (new < TCP_MINMSS)
158 V_tcp_v6mssdflt = new;
163 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
164 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
165 &sysctl_net_inet_tcp_mss_v6_check, "I",
166 "Default TCP Maximum Segment Size for IPv6");
170 * Minimum MSS we accept and use. This prevents DoS attacks where
171 * we are forced to a ridiculous low MSS like 20 and send hundreds
172 * of packets instead of one. The effect scales with the available
173 * bandwidth and quickly saturates the CPU and network interface
174 * with packet generation and sending. Set to zero to disable MINMSS
175 * checking. This setting prevents us from sending too small packets.
177 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
178 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
179 &VNET_NAME(tcp_minmss), 0,
180 "Minimum TCP Maximum Segment Size");
182 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
183 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
184 &VNET_NAME(tcp_do_rfc1323), 0,
185 "Enable rfc1323 (high performance TCP) extensions");
187 static int tcp_log_debug = 0;
188 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
189 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
191 static int tcp_tcbhashsize = 0;
192 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
193 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
195 static int do_tcpdrain = 1;
196 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
197 "Enable tcp_drain routine for extra help when low on mbufs");
199 SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
200 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
202 static VNET_DEFINE(int, icmp_may_rst) = 1;
203 #define V_icmp_may_rst VNET(icmp_may_rst)
204 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
205 &VNET_NAME(icmp_may_rst), 0,
206 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
208 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
209 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
210 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
211 &VNET_NAME(tcp_isn_reseed_interval), 0,
212 "Seconds between reseeding of ISN secret");
214 static int tcp_soreceive_stream = 0;
215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
216 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
219 static int tcp_sig_checksigs = 1;
220 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW,
221 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic");
224 VNET_DEFINE(uma_zone_t, sack_hole_zone);
225 #define V_sack_hole_zone VNET(sack_hole_zone)
227 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
229 static struct inpcb *tcp_notify(struct inpcb *, int);
230 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
231 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
232 void *ip4hdr, const void *ip6hdr);
235 * Target size of TCP PCB hash tables. Must be a power of two.
237 * Note that this can be overridden by the kernel environment
238 * variable net.inet.tcp.tcbhashsize
241 #define TCBHASHSIZE 0
246 * Callouts should be moved into struct tcp directly. They are currently
247 * separate because the tcpcb structure is exported to userland for sysctl
248 * parsing purposes, which do not know about callouts.
257 static VNET_DEFINE(uma_zone_t, tcpcb_zone);
258 #define V_tcpcb_zone VNET(tcpcb_zone)
260 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
261 static struct mtx isn_mtx;
263 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
264 #define ISN_LOCK() mtx_lock(&isn_mtx)
265 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
268 * TCP initialization.
271 tcp_zone_change(void *tag)
274 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
275 uma_zone_set_max(V_tcpcb_zone, maxsockets);
276 tcp_tw_zone_change();
280 tcp_inpcb_init(void *mem, int size, int flags)
282 struct inpcb *inp = mem;
284 INP_LOCK_INIT(inp, "inp", "tcpinp");
289 * Take a value and get the next power of 2 that doesn't overflow.
290 * Used to size the tcp_inpcb hash buckets.
293 maketcp_hashsize(int size)
299 * get the next power of 2 higher than maxsockets.
301 hashsize = 1 << fls(size);
302 /* catch overflow, and just go one power of 2 smaller */
303 if (hashsize < size) {
304 hashsize = 1 << (fls(size) - 1);
312 const char *tcbhash_tuneable;
315 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
317 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
318 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
319 printf("%s: WARNING: unable to register helper hook\n", __func__);
320 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
321 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
322 printf("%s: WARNING: unable to register helper hook\n", __func__);
324 hashsize = TCBHASHSIZE;
325 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
328 * Auto tune the hash size based on maxsockets.
329 * A perfect hash would have a 1:1 mapping
330 * (hashsize = maxsockets) however it's been
331 * suggested that O(2) average is better.
333 hashsize = maketcp_hashsize(maxsockets / 4);
335 * Our historical default is 512,
336 * do not autotune lower than this.
341 printf("%s: %s auto tuned to %d\n", __func__,
342 tcbhash_tuneable, hashsize);
345 * We require a hashsize to be a power of two.
346 * Previously if it was not a power of two we would just reset it
347 * back to 512, which could be a nasty surprise if you did not notice
349 * Instead what we do is clip it to the closest power of two lower
350 * than the specified hash value.
352 if (!powerof2(hashsize)) {
353 int oldhashsize = hashsize;
355 hashsize = maketcp_hashsize(hashsize);
356 /* prevent absurdly low value */
359 printf("%s: WARNING: TCB hash size not a power of 2, "
360 "clipped from %d to %d.\n", __func__, oldhashsize,
363 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
364 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
365 IPI_HASHFIELDS_4TUPLE);
368 * These have to be type stable for the benefit of the timers.
370 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
371 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
372 uma_zone_set_max(V_tcpcb_zone, maxsockets);
373 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
380 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
381 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
382 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
384 /* Skip initialization of globals for non-default instances. */
385 if (!IS_DEFAULT_VNET(curvnet))
388 /* XXX virtualize those bellow? */
389 tcp_delacktime = TCPTV_DELACK;
390 tcp_keepinit = TCPTV_KEEP_INIT;
391 tcp_keepidle = TCPTV_KEEP_IDLE;
392 tcp_keepintvl = TCPTV_KEEPINTVL;
393 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
395 tcp_rexmit_min = TCPTV_MIN;
396 if (tcp_rexmit_min < 1)
398 tcp_rexmit_slop = TCPTV_CPU_VAR;
399 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
400 tcp_tcbhashsize = hashsize;
402 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
403 if (tcp_soreceive_stream) {
405 tcp_usrreqs.pru_soreceive = soreceive_stream;
408 tcp6_usrreqs.pru_soreceive = soreceive_stream;
413 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
415 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
417 if (max_protohdr < TCP_MINPROTOHDR)
418 max_protohdr = TCP_MINPROTOHDR;
419 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
421 #undef TCP_MINPROTOHDR
424 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
425 SHUTDOWN_PRI_DEFAULT);
426 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
427 EVENTHANDLER_PRI_ANY);
439 in_pcbinfo_destroy(&V_tcbinfo);
440 uma_zdestroy(V_sack_hole_zone);
441 uma_zdestroy(V_tcpcb_zone);
452 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
453 * tcp_template used to store this data in mbufs, but we now recopy it out
454 * of the tcpcb each time to conserve mbufs.
457 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
459 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
461 INP_WLOCK_ASSERT(inp);
464 if ((inp->inp_vflag & INP_IPV6) != 0) {
467 ip6 = (struct ip6_hdr *)ip_ptr;
468 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
469 (inp->inp_flow & IPV6_FLOWINFO_MASK);
470 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
471 (IPV6_VERSION & IPV6_VERSION_MASK);
472 ip6->ip6_nxt = IPPROTO_TCP;
473 ip6->ip6_plen = htons(sizeof(struct tcphdr));
474 ip6->ip6_src = inp->in6p_laddr;
475 ip6->ip6_dst = inp->in6p_faddr;
478 #if defined(INET6) && defined(INET)
485 ip = (struct ip *)ip_ptr;
486 ip->ip_v = IPVERSION;
488 ip->ip_tos = inp->inp_ip_tos;
492 ip->ip_ttl = inp->inp_ip_ttl;
494 ip->ip_p = IPPROTO_TCP;
495 ip->ip_src = inp->inp_laddr;
496 ip->ip_dst = inp->inp_faddr;
499 th->th_sport = inp->inp_lport;
500 th->th_dport = inp->inp_fport;
508 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
512 * Create template to be used to send tcp packets on a connection.
513 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
514 * use for this function is in keepalives, which use tcp_respond.
517 tcpip_maketemplate(struct inpcb *inp)
521 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
524 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
529 * Send a single message to the TCP at address specified by
530 * the given TCP/IP header. If m == NULL, then we make a copy
531 * of the tcpiphdr at ti and send directly to the addressed host.
532 * This is used to force keep alive messages out using the TCP
533 * template for a connection. If flags are given then we send
534 * a message back to the TCP which originated the * segment ti,
535 * and discard the mbuf containing it and any other attached mbufs.
537 * In any case the ack and sequence number of the transmitted
538 * segment are as specified by the parameters.
540 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
543 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
544 tcp_seq ack, tcp_seq seq, int flags)
557 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
560 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
567 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
568 INP_WLOCK_ASSERT(inp);
573 if (!(flags & TH_RST)) {
574 win = sbspace(&inp->inp_socket->so_rcv);
575 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
576 win = (long)TCP_MAXWIN << tp->rcv_scale;
580 m = m_gethdr(M_NOWAIT, MT_DATA);
584 m->m_data += max_linkhdr;
587 bcopy((caddr_t)ip6, mtod(m, caddr_t),
588 sizeof(struct ip6_hdr));
589 ip6 = mtod(m, struct ip6_hdr *);
590 nth = (struct tcphdr *)(ip6 + 1);
594 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
595 ip = mtod(m, struct ip *);
596 nth = (struct tcphdr *)(ip + 1);
598 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
603 * XXX MRT We inherrit the FIB, which is lucky.
607 m->m_data = (caddr_t)ipgen;
608 /* m_len is set later */
610 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
613 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
614 nth = (struct tcphdr *)(ip6 + 1);
618 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
619 nth = (struct tcphdr *)(ip + 1);
623 * this is usually a case when an extension header
624 * exists between the IPv6 header and the
627 nth->th_sport = th->th_sport;
628 nth->th_dport = th->th_dport;
630 xchg(nth->th_dport, nth->th_sport, uint16_t);
636 ip6->ip6_vfc = IPV6_VERSION;
637 ip6->ip6_nxt = IPPROTO_TCP;
638 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
639 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
642 #if defined(INET) && defined(INET6)
647 tlen += sizeof (struct tcpiphdr);
648 ip->ip_len = htons(tlen);
649 ip->ip_ttl = V_ip_defttl;
650 if (V_path_mtu_discovery)
651 ip->ip_off |= htons(IP_DF);
655 m->m_pkthdr.len = tlen;
656 m->m_pkthdr.rcvif = NULL;
660 * Packet is associated with a socket, so allow the
661 * label of the response to reflect the socket label.
663 INP_WLOCK_ASSERT(inp);
664 mac_inpcb_create_mbuf(inp, m);
667 * Packet is not associated with a socket, so possibly
668 * update the label in place.
670 mac_netinet_tcp_reply(m);
673 nth->th_seq = htonl(seq);
674 nth->th_ack = htonl(ack);
676 nth->th_off = sizeof (struct tcphdr) >> 2;
677 nth->th_flags = flags;
679 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
681 nth->th_win = htons((u_short)win);
684 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
687 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
688 nth->th_sum = in6_cksum_pseudo(ip6,
689 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
690 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
694 #if defined(INET6) && defined(INET)
699 m->m_pkthdr.csum_flags = CSUM_TCP;
700 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
701 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
705 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
706 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
709 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *),
712 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth);
715 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
717 #if defined(INET) && defined(INET6)
721 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
726 * Create a new TCP control block, making an
727 * empty reassembly queue and hooking it to the argument
728 * protocol control block. The `inp' parameter must have
729 * come from the zone allocator set up in tcp_init().
732 tcp_newtcpcb(struct inpcb *inp)
734 struct tcpcb_mem *tm;
737 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
740 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
745 /* Initialise cc_var struct for this tcpcb. */
747 tp->ccv->type = IPPROTO_TCP;
748 tp->ccv->ccvc.tcp = tp;
751 * Use the current system default CC algorithm.
754 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
755 CC_ALGO(tp) = CC_DEFAULT();
758 if (CC_ALGO(tp)->cb_init != NULL)
759 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
760 uma_zfree(V_tcpcb_zone, tm);
765 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
766 uma_zfree(V_tcpcb_zone, tm);
771 tp->t_vnet = inp->inp_vnet;
773 tp->t_timers = &tm->tt;
774 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
775 tp->t_maxseg = tp->t_maxopd =
777 isipv6 ? V_tcp_v6mssdflt :
781 /* Set up our timeouts. */
782 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
783 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
784 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
785 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
786 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
788 if (V_tcp_do_rfc1323)
789 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
791 tp->t_flags |= TF_SACK_PERMIT;
792 TAILQ_INIT(&tp->snd_holes);
793 tp->t_inpcb = inp; /* XXX */
795 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
796 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
797 * reasonable initial retransmit time.
799 tp->t_srtt = TCPTV_SRTTBASE;
800 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
801 tp->t_rttmin = tcp_rexmit_min;
802 tp->t_rxtcur = TCPTV_RTOBASE;
803 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
804 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
805 tp->t_rcvtime = ticks;
807 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
808 * because the socket may be bound to an IPv6 wildcard address,
809 * which may match an IPv4-mapped IPv6 address.
811 inp->inp_ip_ttl = V_ip_defttl;
813 return (tp); /* XXX */
817 * Switch the congestion control algorithm back to NewReno for any active
818 * control blocks using an algorithm which is about to go away.
819 * This ensures the CC framework can allow the unload to proceed without leaving
820 * any dangling pointers which would trigger a panic.
821 * Returning non-zero would inform the CC framework that something went wrong
822 * and it would be unsafe to allow the unload to proceed. However, there is no
823 * way for this to occur with this implementation so we always return zero.
826 tcp_ccalgounload(struct cc_algo *unload_algo)
828 struct cc_algo *tmpalgo;
831 VNET_ITERATOR_DECL(vnet_iter);
834 * Check all active control blocks across all network stacks and change
835 * any that are using "unload_algo" back to NewReno. If "unload_algo"
836 * requires cleanup code to be run, call it.
839 VNET_FOREACH(vnet_iter) {
840 CURVNET_SET(vnet_iter);
841 INP_INFO_RLOCK(&V_tcbinfo);
843 * New connections already part way through being initialised
844 * with the CC algo we're removing will not race with this code
845 * because the INP_INFO_WLOCK is held during initialisation. We
846 * therefore don't enter the loop below until the connection
847 * list has stabilised.
849 LIST_FOREACH(inp, &V_tcb, inp_list) {
851 /* Important to skip tcptw structs. */
852 if (!(inp->inp_flags & INP_TIMEWAIT) &&
853 (tp = intotcpcb(inp)) != NULL) {
855 * By holding INP_WLOCK here, we are assured
856 * that the connection is not currently
857 * executing inside the CC module's functions
858 * i.e. it is safe to make the switch back to
861 if (CC_ALGO(tp) == unload_algo) {
862 tmpalgo = CC_ALGO(tp);
863 /* NewReno does not require any init. */
864 CC_ALGO(tp) = &newreno_cc_algo;
865 if (tmpalgo->cb_destroy != NULL)
866 tmpalgo->cb_destroy(tp->ccv);
871 INP_INFO_RUNLOCK(&V_tcbinfo);
880 * Drop a TCP connection, reporting
881 * the specified error. If connection is synchronized,
882 * then send a RST to peer.
885 tcp_drop(struct tcpcb *tp, int errno)
887 struct socket *so = tp->t_inpcb->inp_socket;
889 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
890 INP_WLOCK_ASSERT(tp->t_inpcb);
892 if (TCPS_HAVERCVDSYN(tp->t_state)) {
893 tcp_state_change(tp, TCPS_CLOSED);
894 (void) tcp_output(tp);
895 TCPSTAT_INC(tcps_drops);
897 TCPSTAT_INC(tcps_conndrops);
898 if (errno == ETIMEDOUT && tp->t_softerror)
899 errno = tp->t_softerror;
900 so->so_error = errno;
901 return (tcp_close(tp));
905 tcp_discardcb(struct tcpcb *tp)
907 struct inpcb *inp = tp->t_inpcb;
908 struct socket *so = inp->inp_socket;
910 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
913 INP_WLOCK_ASSERT(inp);
916 * Make sure that all of our timers are stopped before we delete the
919 * XXXRW: Really, we would like to use callout_drain() here in order
920 * to avoid races experienced in tcp_timer.c where a timer is already
921 * executing at this point. However, we can't, both because we're
922 * running in a context where we can't sleep, and also because we
923 * hold locks required by the timers. What we instead need to do is
924 * test to see if callout_drain() is required, and if so, defer some
925 * portion of the remainder of tcp_discardcb() to an asynchronous
926 * context that can callout_drain() and then continue. Some care
927 * will be required to ensure that no further processing takes place
928 * on the tcpcb, even though it hasn't been freed (a flag?).
930 callout_stop(&tp->t_timers->tt_rexmt);
931 callout_stop(&tp->t_timers->tt_persist);
932 callout_stop(&tp->t_timers->tt_keep);
933 callout_stop(&tp->t_timers->tt_2msl);
934 callout_stop(&tp->t_timers->tt_delack);
937 * If we got enough samples through the srtt filter,
938 * save the rtt and rttvar in the routing entry.
939 * 'Enough' is arbitrarily defined as 4 rtt samples.
940 * 4 samples is enough for the srtt filter to converge
941 * to within enough % of the correct value; fewer samples
942 * and we could save a bogus rtt. The danger is not high
943 * as tcp quickly recovers from everything.
944 * XXX: Works very well but needs some more statistics!
946 if (tp->t_rttupdated >= 4) {
947 struct hc_metrics_lite metrics;
950 bzero(&metrics, sizeof(metrics));
952 * Update the ssthresh always when the conditions below
953 * are satisfied. This gives us better new start value
954 * for the congestion avoidance for new connections.
955 * ssthresh is only set if packet loss occured on a session.
957 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
958 * being torn down. Ideally this code would not use 'so'.
960 ssthresh = tp->snd_ssthresh;
961 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
963 * convert the limit from user data bytes to
964 * packets then to packet data bytes.
966 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
969 ssthresh *= (u_long)(tp->t_maxseg +
971 (isipv6 ? sizeof (struct ip6_hdr) +
972 sizeof (struct tcphdr) :
974 sizeof (struct tcpiphdr)
981 metrics.rmx_ssthresh = ssthresh;
983 metrics.rmx_rtt = tp->t_srtt;
984 metrics.rmx_rttvar = tp->t_rttvar;
985 metrics.rmx_cwnd = tp->snd_cwnd;
986 metrics.rmx_sendpipe = 0;
987 metrics.rmx_recvpipe = 0;
989 tcp_hc_update(&inp->inp_inc, &metrics);
992 /* free the reassembly queue, if any */
996 /* Disconnect offload device, if any. */
997 if (tp->t_flags & TF_TOE)
998 tcp_offload_detach(tp);
1001 tcp_free_sackholes(tp);
1003 /* Allow the CC algorithm to clean up after itself. */
1004 if (CC_ALGO(tp)->cb_destroy != NULL)
1005 CC_ALGO(tp)->cb_destroy(tp->ccv);
1007 khelp_destroy_osd(tp->osd);
1010 inp->inp_ppcb = NULL;
1012 uma_zfree(V_tcpcb_zone, tp);
1016 * Attempt to close a TCP control block, marking it as dropped, and freeing
1017 * the socket if we hold the only reference.
1020 tcp_close(struct tcpcb *tp)
1022 struct inpcb *inp = tp->t_inpcb;
1025 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1026 INP_WLOCK_ASSERT(inp);
1029 if (tp->t_state == TCPS_LISTEN)
1030 tcp_offload_listen_stop(tp);
1033 TCPSTAT_INC(tcps_closed);
1034 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1035 so = inp->inp_socket;
1036 soisdisconnected(so);
1037 if (inp->inp_flags & INP_SOCKREF) {
1038 KASSERT(so->so_state & SS_PROTOREF,
1039 ("tcp_close: !SS_PROTOREF"));
1040 inp->inp_flags &= ~INP_SOCKREF;
1044 so->so_state &= ~SS_PROTOREF;
1054 VNET_ITERATOR_DECL(vnet_iter);
1059 VNET_LIST_RLOCK_NOSLEEP();
1060 VNET_FOREACH(vnet_iter) {
1061 CURVNET_SET(vnet_iter);
1066 * Walk the tcpbs, if existing, and flush the reassembly queue,
1067 * if there is one...
1068 * XXX: The "Net/3" implementation doesn't imply that the TCP
1069 * reassembly queue should be flushed, but in a situation
1070 * where we're really low on mbufs, this is potentially
1073 INP_INFO_RLOCK(&V_tcbinfo);
1074 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1075 if (inpb->inp_flags & INP_TIMEWAIT)
1078 if ((tcpb = intotcpcb(inpb)) != NULL) {
1079 tcp_reass_flush(tcpb);
1080 tcp_clean_sackreport(tcpb);
1084 INP_INFO_RUNLOCK(&V_tcbinfo);
1087 VNET_LIST_RUNLOCK_NOSLEEP();
1091 * Notify a tcp user of an asynchronous error;
1092 * store error as soft error, but wake up user
1093 * (for now, won't do anything until can select for soft error).
1095 * Do not wake up user since there currently is no mechanism for
1096 * reporting soft errors (yet - a kqueue filter may be added).
1098 static struct inpcb *
1099 tcp_notify(struct inpcb *inp, int error)
1103 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1104 INP_WLOCK_ASSERT(inp);
1106 if ((inp->inp_flags & INP_TIMEWAIT) ||
1107 (inp->inp_flags & INP_DROPPED))
1110 tp = intotcpcb(inp);
1111 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1114 * Ignore some errors if we are hooked up.
1115 * If connection hasn't completed, has retransmitted several times,
1116 * and receives a second error, give up now. This is better
1117 * than waiting a long time to establish a connection that
1118 * can never complete.
1120 if (tp->t_state == TCPS_ESTABLISHED &&
1121 (error == EHOSTUNREACH || error == ENETUNREACH ||
1122 error == EHOSTDOWN)) {
1124 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1126 tp = tcp_drop(tp, error);
1132 tp->t_softerror = error;
1136 wakeup( &so->so_timeo);
1143 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1145 int error, i, m, n, pcb_count;
1146 struct inpcb *inp, **inp_list;
1151 * The process of preparing the TCB list is too time-consuming and
1152 * resource-intensive to repeat twice on every request.
1154 if (req->oldptr == NULL) {
1155 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1156 n += imax(n / 8, 10);
1157 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1161 if (req->newptr != NULL)
1165 * OK, now we're committed to doing something.
1167 INP_INFO_RLOCK(&V_tcbinfo);
1168 gencnt = V_tcbinfo.ipi_gencnt;
1169 n = V_tcbinfo.ipi_count;
1170 INP_INFO_RUNLOCK(&V_tcbinfo);
1172 m = syncache_pcbcount();
1174 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1175 + (n + m) * sizeof(struct xtcpcb));
1179 xig.xig_len = sizeof xig;
1180 xig.xig_count = n + m;
1181 xig.xig_gen = gencnt;
1182 xig.xig_sogen = so_gencnt;
1183 error = SYSCTL_OUT(req, &xig, sizeof xig);
1187 error = syncache_pcblist(req, m, &pcb_count);
1191 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1192 if (inp_list == NULL)
1195 INP_INFO_RLOCK(&V_tcbinfo);
1196 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1197 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1199 if (inp->inp_gencnt <= gencnt) {
1201 * XXX: This use of cr_cansee(), introduced with
1202 * TCP state changes, is not quite right, but for
1203 * now, better than nothing.
1205 if (inp->inp_flags & INP_TIMEWAIT) {
1206 if (intotw(inp) != NULL)
1207 error = cr_cansee(req->td->td_ucred,
1208 intotw(inp)->tw_cred);
1210 error = EINVAL; /* Skip this inp. */
1212 error = cr_canseeinpcb(req->td->td_ucred, inp);
1215 inp_list[i++] = inp;
1220 INP_INFO_RUNLOCK(&V_tcbinfo);
1224 for (i = 0; i < n; i++) {
1227 if (inp->inp_gencnt <= gencnt) {
1231 bzero(&xt, sizeof(xt));
1232 xt.xt_len = sizeof xt;
1233 /* XXX should avoid extra copy */
1234 bcopy(inp, &xt.xt_inp, sizeof *inp);
1235 inp_ppcb = inp->inp_ppcb;
1236 if (inp_ppcb == NULL)
1237 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1238 else if (inp->inp_flags & INP_TIMEWAIT) {
1239 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1240 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1242 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1243 if (xt.xt_tp.t_timers)
1244 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1246 if (inp->inp_socket != NULL)
1247 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1249 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1250 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1252 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1254 error = SYSCTL_OUT(req, &xt, sizeof xt);
1258 INP_INFO_WLOCK(&V_tcbinfo);
1259 for (i = 0; i < n; i++) {
1262 if (!in_pcbrele_rlocked(inp))
1265 INP_INFO_WUNLOCK(&V_tcbinfo);
1269 * Give the user an updated idea of our state.
1270 * If the generation differs from what we told
1271 * her before, she knows that something happened
1272 * while we were processing this request, and it
1273 * might be necessary to retry.
1275 INP_INFO_RLOCK(&V_tcbinfo);
1276 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1277 xig.xig_sogen = so_gencnt;
1278 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1279 INP_INFO_RUNLOCK(&V_tcbinfo);
1280 error = SYSCTL_OUT(req, &xig, sizeof xig);
1282 free(inp_list, M_TEMP);
1286 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1287 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1288 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1292 tcp_getcred(SYSCTL_HANDLER_ARGS)
1295 struct sockaddr_in addrs[2];
1299 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1302 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1305 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1306 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1308 if (inp->inp_socket == NULL)
1311 error = cr_canseeinpcb(req->td->td_ucred, inp);
1313 cru2x(inp->inp_cred, &xuc);
1318 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1322 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1323 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1324 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1329 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1332 struct sockaddr_in6 addrs[2];
1339 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1342 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1345 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1346 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1349 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1351 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1360 inp = in_pcblookup(&V_tcbinfo,
1361 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1363 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1364 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1367 inp = in6_pcblookup(&V_tcbinfo,
1368 &addrs[1].sin6_addr, addrs[1].sin6_port,
1369 &addrs[0].sin6_addr, addrs[0].sin6_port,
1370 INPLOOKUP_RLOCKPCB, NULL);
1372 if (inp->inp_socket == NULL)
1375 error = cr_canseeinpcb(req->td->td_ucred, inp);
1377 cru2x(inp->inp_cred, &xuc);
1382 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1386 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1387 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1388 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1394 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1396 struct ip *ip = vip;
1398 struct in_addr faddr;
1401 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1403 struct in_conninfo inc;
1404 tcp_seq icmp_tcp_seq;
1407 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1408 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1411 if (cmd == PRC_MSGSIZE)
1412 notify = tcp_mtudisc_notify;
1413 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1414 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1415 notify = tcp_drop_syn_sent;
1417 * Redirects don't need to be handled up here.
1419 else if (PRC_IS_REDIRECT(cmd))
1422 * Source quench is depreciated.
1424 else if (cmd == PRC_QUENCH)
1427 * Hostdead is ugly because it goes linearly through all PCBs.
1428 * XXX: We never get this from ICMP, otherwise it makes an
1429 * excellent DoS attack on machines with many connections.
1431 else if (cmd == PRC_HOSTDEAD)
1433 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1436 icp = (struct icmp *)((caddr_t)ip
1437 - offsetof(struct icmp, icmp_ip));
1438 th = (struct tcphdr *)((caddr_t)ip
1439 + (ip->ip_hl << 2));
1440 INP_INFO_WLOCK(&V_tcbinfo);
1441 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1442 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1444 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1445 !(inp->inp_flags & INP_DROPPED) &&
1446 !(inp->inp_socket == NULL)) {
1447 icmp_tcp_seq = htonl(th->th_seq);
1448 tp = intotcpcb(inp);
1449 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1450 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1451 if (cmd == PRC_MSGSIZE) {
1454 * If we got a needfrag set the MTU
1455 * in the route to the suggested new
1456 * value (if given) and then notify.
1458 bzero(&inc, sizeof(inc));
1459 inc.inc_faddr = faddr;
1461 inp->inp_inc.inc_fibnum;
1463 mtu = ntohs(icp->icmp_nextmtu);
1465 * If no alternative MTU was
1466 * proposed, try the next smaller
1471 ntohs(ip->ip_len), 1);
1472 if (mtu < V_tcp_minmss
1473 + sizeof(struct tcpiphdr))
1475 + sizeof(struct tcpiphdr);
1477 * Only cache the MTU if it
1478 * is smaller than the interface
1479 * or route MTU. tcp_mtudisc()
1480 * will do right thing by itself.
1482 if (mtu <= tcp_maxmtu(&inc, NULL))
1483 tcp_hc_updatemtu(&inc, mtu);
1484 tcp_mtudisc(inp, mtu);
1486 inp = (*notify)(inp,
1487 inetctlerrmap[cmd]);
1493 bzero(&inc, sizeof(inc));
1494 inc.inc_fport = th->th_dport;
1495 inc.inc_lport = th->th_sport;
1496 inc.inc_faddr = faddr;
1497 inc.inc_laddr = ip->ip_src;
1498 syncache_unreach(&inc, th);
1500 INP_INFO_WUNLOCK(&V_tcbinfo);
1502 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1508 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1511 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1512 struct ip6_hdr *ip6;
1514 struct ip6ctlparam *ip6cp = NULL;
1515 const struct sockaddr_in6 *sa6_src = NULL;
1517 struct tcp_portonly {
1522 if (sa->sa_family != AF_INET6 ||
1523 sa->sa_len != sizeof(struct sockaddr_in6))
1526 if (cmd == PRC_MSGSIZE)
1527 notify = tcp_mtudisc_notify;
1528 else if (!PRC_IS_REDIRECT(cmd) &&
1529 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1531 /* Source quench is depreciated. */
1532 else if (cmd == PRC_QUENCH)
1535 /* if the parameter is from icmp6, decode it. */
1537 ip6cp = (struct ip6ctlparam *)d;
1539 ip6 = ip6cp->ip6c_ip6;
1540 off = ip6cp->ip6c_off;
1541 sa6_src = ip6cp->ip6c_src;
1545 off = 0; /* fool gcc */
1550 struct in_conninfo inc;
1552 * XXX: We assume that when IPV6 is non NULL,
1553 * M and OFF are valid.
1556 /* check if we can safely examine src and dst ports */
1557 if (m->m_pkthdr.len < off + sizeof(*thp))
1560 bzero(&th, sizeof(th));
1561 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1563 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1564 (struct sockaddr *)ip6cp->ip6c_src,
1565 th.th_sport, cmd, NULL, notify);
1567 bzero(&inc, sizeof(inc));
1568 inc.inc_fport = th.th_dport;
1569 inc.inc_lport = th.th_sport;
1570 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1571 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1572 inc.inc_flags |= INC_ISIPV6;
1573 INP_INFO_WLOCK(&V_tcbinfo);
1574 syncache_unreach(&inc, &th);
1575 INP_INFO_WUNLOCK(&V_tcbinfo);
1577 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1578 0, cmd, NULL, notify);
1584 * Following is where TCP initial sequence number generation occurs.
1586 * There are two places where we must use initial sequence numbers:
1587 * 1. In SYN-ACK packets.
1588 * 2. In SYN packets.
1590 * All ISNs for SYN-ACK packets are generated by the syncache. See
1591 * tcp_syncache.c for details.
1593 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1594 * depends on this property. In addition, these ISNs should be
1595 * unguessable so as to prevent connection hijacking. To satisfy
1596 * the requirements of this situation, the algorithm outlined in
1597 * RFC 1948 is used, with only small modifications.
1599 * Implementation details:
1601 * Time is based off the system timer, and is corrected so that it
1602 * increases by one megabyte per second. This allows for proper
1603 * recycling on high speed LANs while still leaving over an hour
1606 * As reading the *exact* system time is too expensive to be done
1607 * whenever setting up a TCP connection, we increment the time
1608 * offset in two ways. First, a small random positive increment
1609 * is added to isn_offset for each connection that is set up.
1610 * Second, the function tcp_isn_tick fires once per clock tick
1611 * and increments isn_offset as necessary so that sequence numbers
1612 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1613 * random positive increments serve only to ensure that the same
1614 * exact sequence number is never sent out twice (as could otherwise
1615 * happen when a port is recycled in less than the system tick
1618 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1619 * between seeding of isn_secret. This is normally set to zero,
1620 * as reseeding should not be necessary.
1622 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1623 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1624 * general, this means holding an exclusive (write) lock.
1627 #define ISN_BYTES_PER_SECOND 1048576
1628 #define ISN_STATIC_INCREMENT 4096
1629 #define ISN_RANDOM_INCREMENT (4096 - 1)
1631 static VNET_DEFINE(u_char, isn_secret[32]);
1632 static VNET_DEFINE(int, isn_last);
1633 static VNET_DEFINE(int, isn_last_reseed);
1634 static VNET_DEFINE(u_int32_t, isn_offset);
1635 static VNET_DEFINE(u_int32_t, isn_offset_old);
1637 #define V_isn_secret VNET(isn_secret)
1638 #define V_isn_last VNET(isn_last)
1639 #define V_isn_last_reseed VNET(isn_last_reseed)
1640 #define V_isn_offset VNET(isn_offset)
1641 #define V_isn_offset_old VNET(isn_offset_old)
1644 tcp_new_isn(struct tcpcb *tp)
1647 u_int32_t md5_buffer[4];
1649 u_int32_t projected_offset;
1651 INP_WLOCK_ASSERT(tp->t_inpcb);
1654 /* Seed if this is the first use, reseed if requested. */
1655 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1656 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1658 read_random(&V_isn_secret, sizeof(V_isn_secret));
1659 V_isn_last_reseed = ticks;
1662 /* Compute the md5 hash and return the ISN. */
1664 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1665 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1667 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1669 sizeof(struct in6_addr));
1670 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1671 sizeof(struct in6_addr));
1675 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1676 sizeof(struct in_addr));
1677 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1678 sizeof(struct in_addr));
1680 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1681 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1682 new_isn = (tcp_seq) md5_buffer[0];
1683 V_isn_offset += ISN_STATIC_INCREMENT +
1684 (arc4random() & ISN_RANDOM_INCREMENT);
1685 if (ticks != V_isn_last) {
1686 projected_offset = V_isn_offset_old +
1687 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1688 if (SEQ_GT(projected_offset, V_isn_offset))
1689 V_isn_offset = projected_offset;
1690 V_isn_offset_old = V_isn_offset;
1693 new_isn += V_isn_offset;
1699 * When a specific ICMP unreachable message is received and the
1700 * connection state is SYN-SENT, drop the connection. This behavior
1701 * is controlled by the icmp_may_rst sysctl.
1704 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1708 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1709 INP_WLOCK_ASSERT(inp);
1711 if ((inp->inp_flags & INP_TIMEWAIT) ||
1712 (inp->inp_flags & INP_DROPPED))
1715 tp = intotcpcb(inp);
1716 if (tp->t_state != TCPS_SYN_SENT)
1719 tp = tcp_drop(tp, errno);
1727 * When `need fragmentation' ICMP is received, update our idea of the MSS
1728 * based on the new value. Also nudge TCP to send something, since we
1729 * know the packet we just sent was dropped.
1730 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1732 static struct inpcb *
1733 tcp_mtudisc_notify(struct inpcb *inp, int error)
1736 return (tcp_mtudisc(inp, -1));
1740 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1745 INP_WLOCK_ASSERT(inp);
1746 if ((inp->inp_flags & INP_TIMEWAIT) ||
1747 (inp->inp_flags & INP_DROPPED))
1750 tp = intotcpcb(inp);
1751 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1753 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1755 so = inp->inp_socket;
1756 SOCKBUF_LOCK(&so->so_snd);
1757 /* If the mss is larger than the socket buffer, decrease the mss. */
1758 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1759 tp->t_maxseg = so->so_snd.sb_hiwat;
1760 SOCKBUF_UNLOCK(&so->so_snd);
1762 TCPSTAT_INC(tcps_mturesent);
1764 tp->snd_nxt = tp->snd_una;
1765 tcp_free_sackholes(tp);
1766 tp->snd_recover = tp->snd_max;
1767 if (tp->t_flags & TF_SACK_PERMIT)
1768 EXIT_FASTRECOVERY(tp->t_flags);
1775 * Look-up the routing entry to the peer of this inpcb. If no route
1776 * is found and it cannot be allocated, then return 0. This routine
1777 * is called by TCP routines that access the rmx structure and by
1778 * tcp_mss_update to get the peer/interface MTU.
1781 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1784 struct sockaddr_in *dst;
1788 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1790 bzero(&sro, sizeof(sro));
1791 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1792 dst = (struct sockaddr_in *)&sro.ro_dst;
1793 dst->sin_family = AF_INET;
1794 dst->sin_len = sizeof(*dst);
1795 dst->sin_addr = inc->inc_faddr;
1796 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1798 if (sro.ro_rt != NULL) {
1799 ifp = sro.ro_rt->rt_ifp;
1800 if (sro.ro_rt->rt_mtu == 0)
1801 maxmtu = ifp->if_mtu;
1803 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu);
1805 /* Report additional interface capabilities. */
1807 if (ifp->if_capenable & IFCAP_TSO4 &&
1808 ifp->if_hwassist & CSUM_TSO) {
1809 cap->ifcap |= CSUM_TSO;
1810 cap->tsomax = ifp->if_hw_tsomax;
1821 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1823 struct route_in6 sro6;
1827 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1829 bzero(&sro6, sizeof(sro6));
1830 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1831 sro6.ro_dst.sin6_family = AF_INET6;
1832 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1833 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1834 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1836 if (sro6.ro_rt != NULL) {
1837 ifp = sro6.ro_rt->rt_ifp;
1838 if (sro6.ro_rt->rt_mtu == 0)
1839 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1841 maxmtu = min(sro6.ro_rt->rt_mtu,
1842 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1844 /* Report additional interface capabilities. */
1846 if (ifp->if_capenable & IFCAP_TSO6 &&
1847 ifp->if_hwassist & CSUM_TSO) {
1848 cap->ifcap |= CSUM_TSO;
1849 cap->tsomax = ifp->if_hw_tsomax;
1860 /* compute ESP/AH header size for TCP, including outer IP header. */
1862 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1869 struct ip6_hdr *ip6;
1873 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1875 m = m_gethdr(M_NOWAIT, MT_DATA);
1880 if ((inp->inp_vflag & INP_IPV6) != 0) {
1881 ip6 = mtod(m, struct ip6_hdr *);
1882 th = (struct tcphdr *)(ip6 + 1);
1883 m->m_pkthdr.len = m->m_len =
1884 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1885 tcpip_fillheaders(inp, ip6, th);
1886 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1890 ip = mtod(m, struct ip *);
1891 th = (struct tcphdr *)(ip + 1);
1892 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1893 tcpip_fillheaders(inp, ip, th);
1894 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1902 #ifdef TCP_SIGNATURE
1904 * Callback function invoked by m_apply() to digest TCP segment data
1905 * contained within an mbuf chain.
1908 tcp_signature_apply(void *fstate, void *data, u_int len)
1911 MD5Update(fstate, (u_char *)data, len);
1916 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1919 * m pointer to head of mbuf chain
1921 * len length of TCP segment data, excluding options
1922 * optlen length of TCP segment options
1923 * buf pointer to storage for computed MD5 digest
1924 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1926 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1927 * When called from tcp_input(), we can be sure that th_sum has been
1928 * zeroed out and verified already.
1930 * Return 0 if successful, otherwise return -1.
1932 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1933 * search with the destination IP address, and a 'magic SPI' to be
1934 * determined by the application. This is hardcoded elsewhere to 1179
1935 * right now. Another branch of this code exists which uses the SPD to
1936 * specify per-application flows but it is unstable.
1939 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1940 u_char *buf, u_int direction)
1942 union sockaddr_union dst;
1944 struct ippseudo ippseudo;
1950 struct ipovly *ipovly;
1952 struct secasvar *sav;
1955 struct ip6_hdr *ip6;
1956 struct in6_addr in6;
1957 char ip6buf[INET6_ADDRSTRLEN];
1963 KASSERT(m != NULL, ("NULL mbuf chain"));
1964 KASSERT(buf != NULL, ("NULL signature pointer"));
1966 /* Extract the destination from the IP header in the mbuf. */
1967 bzero(&dst, sizeof(union sockaddr_union));
1968 ip = mtod(m, struct ip *);
1970 ip6 = NULL; /* Make the compiler happy. */
1975 dst.sa.sa_len = sizeof(struct sockaddr_in);
1976 dst.sa.sa_family = AF_INET;
1977 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1978 ip->ip_src : ip->ip_dst;
1982 case (IPV6_VERSION >> 4):
1983 ip6 = mtod(m, struct ip6_hdr *);
1984 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1985 dst.sa.sa_family = AF_INET6;
1986 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1987 ip6->ip6_src : ip6->ip6_dst;
1996 /* Look up an SADB entry which matches the address of the peer. */
1997 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1999 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
2000 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
2002 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2003 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2011 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2013 * XXX The ippseudo header MUST be digested in network byte order,
2014 * or else we'll fail the regression test. Assume all fields we've
2015 * been doing arithmetic on have been in host byte order.
2016 * XXX One cannot depend on ipovly->ih_len here. When called from
2017 * tcp_output(), the underlying ip_len member has not yet been set.
2022 ipovly = (struct ipovly *)ip;
2023 ippseudo.ippseudo_src = ipovly->ih_src;
2024 ippseudo.ippseudo_dst = ipovly->ih_dst;
2025 ippseudo.ippseudo_pad = 0;
2026 ippseudo.ippseudo_p = IPPROTO_TCP;
2027 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2029 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2031 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2032 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2037 * RFC 2385, 2.0 Proposal
2038 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2039 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2040 * extended next header value (to form 32 bits), and 32-bit segment
2042 * Note: Upper-Layer Packet Length comes before Next Header.
2044 case (IPV6_VERSION >> 4):
2046 in6_clearscope(&in6);
2047 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2049 in6_clearscope(&in6);
2050 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2051 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2052 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2054 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2055 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2056 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2058 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2060 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2061 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2072 * Step 2: Update MD5 hash with TCP header, excluding options.
2073 * The TCP checksum must be set to zero.
2075 savecsum = th->th_sum;
2077 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2078 th->th_sum = savecsum;
2081 * Step 3: Update MD5 hash with TCP segment data.
2082 * Use m_apply() to avoid an early m_pullup().
2085 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2088 * Step 4: Update MD5 hash with shared secret.
2090 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2091 MD5Final(buf, &ctx);
2093 key_sa_recordxfer(sav, m);
2099 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2102 * m pointer to head of mbuf chain
2103 * len length of TCP segment data, excluding options
2104 * optlen length of TCP segment options
2105 * buf pointer to storage for computed MD5 digest
2106 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2108 * Return 1 if successful, otherwise return 0.
2111 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2112 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2114 char tmpdigest[TCP_SIGLEN];
2116 if (tcp_sig_checksigs == 0)
2118 if ((tcpbflag & TF_SIGNATURE) == 0) {
2119 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2122 * If this socket is not expecting signature but
2123 * the segment contains signature just fail.
2125 TCPSTAT_INC(tcps_sig_err_sigopt);
2126 TCPSTAT_INC(tcps_sig_rcvbadsig);
2130 /* Signature is not expected, and not present in segment. */
2135 * If this socket is expecting signature but the segment does not
2136 * contain any just fail.
2138 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2139 TCPSTAT_INC(tcps_sig_err_nosigopt);
2140 TCPSTAT_INC(tcps_sig_rcvbadsig);
2143 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2144 IPSEC_DIR_INBOUND) == -1) {
2145 TCPSTAT_INC(tcps_sig_err_buildsig);
2146 TCPSTAT_INC(tcps_sig_rcvbadsig);
2150 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2151 TCPSTAT_INC(tcps_sig_rcvbadsig);
2154 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2157 #endif /* TCP_SIGNATURE */
2160 sysctl_drop(SYSCTL_HANDLER_ARGS)
2162 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2163 struct sockaddr_storage addrs[2];
2167 struct sockaddr_in *fin, *lin;
2169 struct sockaddr_in6 *fin6, *lin6;
2180 if (req->oldptr != NULL || req->oldlen != 0)
2182 if (req->newptr == NULL)
2184 if (req->newlen < sizeof(addrs))
2186 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2190 switch (addrs[0].ss_family) {
2193 fin6 = (struct sockaddr_in6 *)&addrs[0];
2194 lin6 = (struct sockaddr_in6 *)&addrs[1];
2195 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2196 lin6->sin6_len != sizeof(struct sockaddr_in6))
2198 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2199 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2201 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2202 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2203 fin = (struct sockaddr_in *)&addrs[0];
2204 lin = (struct sockaddr_in *)&addrs[1];
2207 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2210 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2217 fin = (struct sockaddr_in *)&addrs[0];
2218 lin = (struct sockaddr_in *)&addrs[1];
2219 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2220 lin->sin_len != sizeof(struct sockaddr_in))
2227 INP_INFO_WLOCK(&V_tcbinfo);
2228 switch (addrs[0].ss_family) {
2231 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2232 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2233 INPLOOKUP_WLOCKPCB, NULL);
2238 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2239 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2244 if (inp->inp_flags & INP_TIMEWAIT) {
2246 * XXXRW: There currently exists a state where an
2247 * inpcb is present, but its timewait state has been
2248 * discarded. For now, don't allow dropping of this
2256 } else if (!(inp->inp_flags & INP_DROPPED) &&
2257 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2258 tp = intotcpcb(inp);
2259 tp = tcp_drop(tp, ECONNABORTED);
2266 INP_INFO_WUNLOCK(&V_tcbinfo);
2270 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2271 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2272 0, sysctl_drop, "", "Drop TCP connection");
2275 * Generate a standardized TCP log line for use throughout the
2276 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2277 * allow use in the interrupt context.
2279 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2280 * NB: The function may return NULL if memory allocation failed.
2282 * Due to header inclusion and ordering limitations the struct ip
2283 * and ip6_hdr pointers have to be passed as void pointers.
2286 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2290 /* Is logging enabled? */
2291 if (tcp_log_in_vain == 0)
2294 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2298 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2302 /* Is logging enabled? */
2303 if (tcp_log_debug == 0)
2306 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2310 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2317 const struct ip6_hdr *ip6;
2319 ip6 = (const struct ip6_hdr *)ip6hdr;
2321 ip = (struct ip *)ip4hdr;
2324 * The log line looks like this:
2325 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2327 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2328 sizeof(PRINT_TH_FLAGS) + 1 +
2330 2 * INET6_ADDRSTRLEN;
2332 2 * INET_ADDRSTRLEN;
2335 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2339 strcat(s, "TCP: [");
2342 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2343 inet_ntoa_r(inc->inc_faddr, sp);
2345 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2347 inet_ntoa_r(inc->inc_laddr, sp);
2349 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2352 ip6_sprintf(sp, &inc->inc6_faddr);
2354 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2356 ip6_sprintf(sp, &inc->inc6_laddr);
2358 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2359 } else if (ip6 && th) {
2360 ip6_sprintf(sp, &ip6->ip6_src);
2362 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2364 ip6_sprintf(sp, &ip6->ip6_dst);
2366 sprintf(sp, "]:%i", ntohs(th->th_dport));
2369 } else if (ip && th) {
2370 inet_ntoa_r(ip->ip_src, sp);
2372 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2374 inet_ntoa_r(ip->ip_dst, sp);
2376 sprintf(sp, "]:%i", ntohs(th->th_dport));
2384 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2385 if (*(s + size - 1) != '\0')
2386 panic("%s: string too long", __func__);
2391 * A subroutine which makes it easy to track TCP state changes with DTrace.
2392 * This function shouldn't be called for t_state initializations that don't
2393 * correspond to actual TCP state transitions.
2396 tcp_state_change(struct tcpcb *tp, int newstate)
2398 #if defined(KDTRACE_HOOKS)
2399 int pstate = tp->t_state;
2402 tp->t_state = newstate;
2403 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);