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>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/protosw.h>
60 #include <sys/random.h>
64 #include <net/route.h>
66 #include <net/if_var.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");
379 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
380 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
381 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
383 /* Skip initialization of globals for non-default instances. */
384 if (!IS_DEFAULT_VNET(curvnet))
387 /* XXX virtualize those bellow? */
388 tcp_delacktime = TCPTV_DELACK;
389 tcp_keepinit = TCPTV_KEEP_INIT;
390 tcp_keepidle = TCPTV_KEEP_IDLE;
391 tcp_keepintvl = TCPTV_KEEPINTVL;
392 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
394 tcp_rexmit_min = TCPTV_MIN;
395 if (tcp_rexmit_min < 1)
397 tcp_rexmit_slop = TCPTV_CPU_VAR;
398 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
399 tcp_tcbhashsize = hashsize;
401 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
402 if (tcp_soreceive_stream) {
404 tcp_usrreqs.pru_soreceive = soreceive_stream;
407 tcp6_usrreqs.pru_soreceive = soreceive_stream;
412 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
414 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
416 if (max_protohdr < TCP_MINPROTOHDR)
417 max_protohdr = TCP_MINPROTOHDR;
418 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
420 #undef TCP_MINPROTOHDR
423 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
424 SHUTDOWN_PRI_DEFAULT);
425 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
426 EVENTHANDLER_PRI_ANY);
438 in_pcbinfo_destroy(&V_tcbinfo);
439 uma_zdestroy(V_sack_hole_zone);
440 uma_zdestroy(V_tcpcb_zone);
442 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
444 printf("%s: WARNING: unable to deregister helper hook "
445 "type=%d, id=%d: error %d returned\n", __func__,
446 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
448 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
450 printf("%s: WARNING: unable to deregister helper hook "
451 "type=%d, id=%d: error %d returned\n", __func__,
452 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
464 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
465 * tcp_template used to store this data in mbufs, but we now recopy it out
466 * of the tcpcb each time to conserve mbufs.
469 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
471 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
473 INP_WLOCK_ASSERT(inp);
476 if ((inp->inp_vflag & INP_IPV6) != 0) {
479 ip6 = (struct ip6_hdr *)ip_ptr;
480 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
481 (inp->inp_flow & IPV6_FLOWINFO_MASK);
482 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
483 (IPV6_VERSION & IPV6_VERSION_MASK);
484 ip6->ip6_nxt = IPPROTO_TCP;
485 ip6->ip6_plen = htons(sizeof(struct tcphdr));
486 ip6->ip6_src = inp->in6p_laddr;
487 ip6->ip6_dst = inp->in6p_faddr;
490 #if defined(INET6) && defined(INET)
497 ip = (struct ip *)ip_ptr;
498 ip->ip_v = IPVERSION;
500 ip->ip_tos = inp->inp_ip_tos;
504 ip->ip_ttl = inp->inp_ip_ttl;
506 ip->ip_p = IPPROTO_TCP;
507 ip->ip_src = inp->inp_laddr;
508 ip->ip_dst = inp->inp_faddr;
511 th->th_sport = inp->inp_lport;
512 th->th_dport = inp->inp_fport;
520 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
524 * Create template to be used to send tcp packets on a connection.
525 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
526 * use for this function is in keepalives, which use tcp_respond.
529 tcpip_maketemplate(struct inpcb *inp)
533 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
536 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
541 * Send a single message to the TCP at address specified by
542 * the given TCP/IP header. If m == NULL, then we make a copy
543 * of the tcpiphdr at ti and send directly to the addressed host.
544 * This is used to force keep alive messages out using the TCP
545 * template for a connection. If flags are given then we send
546 * a message back to the TCP which originated the * segment ti,
547 * and discard the mbuf containing it and any other attached mbufs.
549 * In any case the ack and sequence number of the transmitted
550 * segment are as specified by the parameters.
552 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
555 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
556 tcp_seq ack, tcp_seq seq, int flags)
569 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
572 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
579 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
580 INP_WLOCK_ASSERT(inp);
585 if (!(flags & TH_RST)) {
586 win = sbspace(&inp->inp_socket->so_rcv);
587 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
588 win = (long)TCP_MAXWIN << tp->rcv_scale;
592 m = m_gethdr(M_NOWAIT, MT_DATA);
596 m->m_data += max_linkhdr;
599 bcopy((caddr_t)ip6, mtod(m, caddr_t),
600 sizeof(struct ip6_hdr));
601 ip6 = mtod(m, struct ip6_hdr *);
602 nth = (struct tcphdr *)(ip6 + 1);
606 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
607 ip = mtod(m, struct ip *);
608 nth = (struct tcphdr *)(ip + 1);
610 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
615 * XXX MRT We inherrit the FIB, which is lucky.
619 m->m_data = (caddr_t)ipgen;
620 /* m_len is set later */
622 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
625 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
626 nth = (struct tcphdr *)(ip6 + 1);
630 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
631 nth = (struct tcphdr *)(ip + 1);
635 * this is usually a case when an extension header
636 * exists between the IPv6 header and the
639 nth->th_sport = th->th_sport;
640 nth->th_dport = th->th_dport;
642 xchg(nth->th_dport, nth->th_sport, uint16_t);
648 ip6->ip6_vfc = IPV6_VERSION;
649 ip6->ip6_nxt = IPPROTO_TCP;
650 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
651 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
654 #if defined(INET) && defined(INET6)
659 tlen += sizeof (struct tcpiphdr);
660 ip->ip_len = htons(tlen);
661 ip->ip_ttl = V_ip_defttl;
662 if (V_path_mtu_discovery)
663 ip->ip_off |= htons(IP_DF);
667 m->m_pkthdr.len = tlen;
668 m->m_pkthdr.rcvif = NULL;
672 * Packet is associated with a socket, so allow the
673 * label of the response to reflect the socket label.
675 INP_WLOCK_ASSERT(inp);
676 mac_inpcb_create_mbuf(inp, m);
679 * Packet is not associated with a socket, so possibly
680 * update the label in place.
682 mac_netinet_tcp_reply(m);
685 nth->th_seq = htonl(seq);
686 nth->th_ack = htonl(ack);
688 nth->th_off = sizeof (struct tcphdr) >> 2;
689 nth->th_flags = flags;
691 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
693 nth->th_win = htons((u_short)win);
696 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
699 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
700 nth->th_sum = in6_cksum_pseudo(ip6,
701 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
702 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
706 #if defined(INET6) && defined(INET)
711 m->m_pkthdr.csum_flags = CSUM_TCP;
712 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
713 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
717 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
718 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
721 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *),
724 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth);
727 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
729 #if defined(INET) && defined(INET6)
733 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
738 * Create a new TCP control block, making an
739 * empty reassembly queue and hooking it to the argument
740 * protocol control block. The `inp' parameter must have
741 * come from the zone allocator set up in tcp_init().
744 tcp_newtcpcb(struct inpcb *inp)
746 struct tcpcb_mem *tm;
749 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
752 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
757 /* Initialise cc_var struct for this tcpcb. */
759 tp->ccv->type = IPPROTO_TCP;
760 tp->ccv->ccvc.tcp = tp;
763 * Use the current system default CC algorithm.
766 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
767 CC_ALGO(tp) = CC_DEFAULT();
770 if (CC_ALGO(tp)->cb_init != NULL)
771 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
772 uma_zfree(V_tcpcb_zone, tm);
777 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
778 uma_zfree(V_tcpcb_zone, tm);
783 tp->t_vnet = inp->inp_vnet;
785 tp->t_timers = &tm->tt;
786 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
787 tp->t_maxseg = tp->t_maxopd =
789 isipv6 ? V_tcp_v6mssdflt :
793 /* Set up our timeouts. */
794 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
795 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
796 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
797 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
798 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
800 if (V_tcp_do_rfc1323)
801 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
803 tp->t_flags |= TF_SACK_PERMIT;
804 TAILQ_INIT(&tp->snd_holes);
805 tp->t_inpcb = inp; /* XXX */
807 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
808 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
809 * reasonable initial retransmit time.
811 tp->t_srtt = TCPTV_SRTTBASE;
812 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
813 tp->t_rttmin = tcp_rexmit_min;
814 tp->t_rxtcur = TCPTV_RTOBASE;
815 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
816 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
817 tp->t_rcvtime = ticks;
819 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
820 * because the socket may be bound to an IPv6 wildcard address,
821 * which may match an IPv4-mapped IPv6 address.
823 inp->inp_ip_ttl = V_ip_defttl;
825 return (tp); /* XXX */
829 * Switch the congestion control algorithm back to NewReno for any active
830 * control blocks using an algorithm which is about to go away.
831 * This ensures the CC framework can allow the unload to proceed without leaving
832 * any dangling pointers which would trigger a panic.
833 * Returning non-zero would inform the CC framework that something went wrong
834 * and it would be unsafe to allow the unload to proceed. However, there is no
835 * way for this to occur with this implementation so we always return zero.
838 tcp_ccalgounload(struct cc_algo *unload_algo)
840 struct cc_algo *tmpalgo;
843 VNET_ITERATOR_DECL(vnet_iter);
846 * Check all active control blocks across all network stacks and change
847 * any that are using "unload_algo" back to NewReno. If "unload_algo"
848 * requires cleanup code to be run, call it.
851 VNET_FOREACH(vnet_iter) {
852 CURVNET_SET(vnet_iter);
853 INP_INFO_RLOCK(&V_tcbinfo);
855 * New connections already part way through being initialised
856 * with the CC algo we're removing will not race with this code
857 * because the INP_INFO_WLOCK is held during initialisation. We
858 * therefore don't enter the loop below until the connection
859 * list has stabilised.
861 LIST_FOREACH(inp, &V_tcb, inp_list) {
863 /* Important to skip tcptw structs. */
864 if (!(inp->inp_flags & INP_TIMEWAIT) &&
865 (tp = intotcpcb(inp)) != NULL) {
867 * By holding INP_WLOCK here, we are assured
868 * that the connection is not currently
869 * executing inside the CC module's functions
870 * i.e. it is safe to make the switch back to
873 if (CC_ALGO(tp) == unload_algo) {
874 tmpalgo = CC_ALGO(tp);
875 /* NewReno does not require any init. */
876 CC_ALGO(tp) = &newreno_cc_algo;
877 if (tmpalgo->cb_destroy != NULL)
878 tmpalgo->cb_destroy(tp->ccv);
883 INP_INFO_RUNLOCK(&V_tcbinfo);
892 * Drop a TCP connection, reporting
893 * the specified error. If connection is synchronized,
894 * then send a RST to peer.
897 tcp_drop(struct tcpcb *tp, int errno)
899 struct socket *so = tp->t_inpcb->inp_socket;
901 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
902 INP_WLOCK_ASSERT(tp->t_inpcb);
904 if (TCPS_HAVERCVDSYN(tp->t_state)) {
905 tcp_state_change(tp, TCPS_CLOSED);
906 (void) tcp_output(tp);
907 TCPSTAT_INC(tcps_drops);
909 TCPSTAT_INC(tcps_conndrops);
910 if (errno == ETIMEDOUT && tp->t_softerror)
911 errno = tp->t_softerror;
912 so->so_error = errno;
913 return (tcp_close(tp));
917 tcp_discardcb(struct tcpcb *tp)
919 struct inpcb *inp = tp->t_inpcb;
920 struct socket *so = inp->inp_socket;
922 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
925 INP_WLOCK_ASSERT(inp);
928 * Make sure that all of our timers are stopped before we delete the
931 * XXXRW: Really, we would like to use callout_drain() here in order
932 * to avoid races experienced in tcp_timer.c where a timer is already
933 * executing at this point. However, we can't, both because we're
934 * running in a context where we can't sleep, and also because we
935 * hold locks required by the timers. What we instead need to do is
936 * test to see if callout_drain() is required, and if so, defer some
937 * portion of the remainder of tcp_discardcb() to an asynchronous
938 * context that can callout_drain() and then continue. Some care
939 * will be required to ensure that no further processing takes place
940 * on the tcpcb, even though it hasn't been freed (a flag?).
942 callout_stop(&tp->t_timers->tt_rexmt);
943 callout_stop(&tp->t_timers->tt_persist);
944 callout_stop(&tp->t_timers->tt_keep);
945 callout_stop(&tp->t_timers->tt_2msl);
946 callout_stop(&tp->t_timers->tt_delack);
949 * If we got enough samples through the srtt filter,
950 * save the rtt and rttvar in the routing entry.
951 * 'Enough' is arbitrarily defined as 4 rtt samples.
952 * 4 samples is enough for the srtt filter to converge
953 * to within enough % of the correct value; fewer samples
954 * and we could save a bogus rtt. The danger is not high
955 * as tcp quickly recovers from everything.
956 * XXX: Works very well but needs some more statistics!
958 if (tp->t_rttupdated >= 4) {
959 struct hc_metrics_lite metrics;
962 bzero(&metrics, sizeof(metrics));
964 * Update the ssthresh always when the conditions below
965 * are satisfied. This gives us better new start value
966 * for the congestion avoidance for new connections.
967 * ssthresh is only set if packet loss occured on a session.
969 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
970 * being torn down. Ideally this code would not use 'so'.
972 ssthresh = tp->snd_ssthresh;
973 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
975 * convert the limit from user data bytes to
976 * packets then to packet data bytes.
978 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
981 ssthresh *= (u_long)(tp->t_maxseg +
983 (isipv6 ? sizeof (struct ip6_hdr) +
984 sizeof (struct tcphdr) :
986 sizeof (struct tcpiphdr)
993 metrics.rmx_ssthresh = ssthresh;
995 metrics.rmx_rtt = tp->t_srtt;
996 metrics.rmx_rttvar = tp->t_rttvar;
997 metrics.rmx_cwnd = tp->snd_cwnd;
998 metrics.rmx_sendpipe = 0;
999 metrics.rmx_recvpipe = 0;
1001 tcp_hc_update(&inp->inp_inc, &metrics);
1004 /* free the reassembly queue, if any */
1005 tcp_reass_flush(tp);
1008 /* Disconnect offload device, if any. */
1009 if (tp->t_flags & TF_TOE)
1010 tcp_offload_detach(tp);
1013 tcp_free_sackholes(tp);
1015 /* Allow the CC algorithm to clean up after itself. */
1016 if (CC_ALGO(tp)->cb_destroy != NULL)
1017 CC_ALGO(tp)->cb_destroy(tp->ccv);
1019 khelp_destroy_osd(tp->osd);
1022 inp->inp_ppcb = NULL;
1024 uma_zfree(V_tcpcb_zone, tp);
1028 * Attempt to close a TCP control block, marking it as dropped, and freeing
1029 * the socket if we hold the only reference.
1032 tcp_close(struct tcpcb *tp)
1034 struct inpcb *inp = tp->t_inpcb;
1037 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1038 INP_WLOCK_ASSERT(inp);
1041 if (tp->t_state == TCPS_LISTEN)
1042 tcp_offload_listen_stop(tp);
1045 TCPSTAT_INC(tcps_closed);
1046 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1047 so = inp->inp_socket;
1048 soisdisconnected(so);
1049 if (inp->inp_flags & INP_SOCKREF) {
1050 KASSERT(so->so_state & SS_PROTOREF,
1051 ("tcp_close: !SS_PROTOREF"));
1052 inp->inp_flags &= ~INP_SOCKREF;
1056 so->so_state &= ~SS_PROTOREF;
1066 VNET_ITERATOR_DECL(vnet_iter);
1071 VNET_LIST_RLOCK_NOSLEEP();
1072 VNET_FOREACH(vnet_iter) {
1073 CURVNET_SET(vnet_iter);
1078 * Walk the tcpbs, if existing, and flush the reassembly queue,
1079 * if there is one...
1080 * XXX: The "Net/3" implementation doesn't imply that the TCP
1081 * reassembly queue should be flushed, but in a situation
1082 * where we're really low on mbufs, this is potentially
1085 INP_INFO_RLOCK(&V_tcbinfo);
1086 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1087 if (inpb->inp_flags & INP_TIMEWAIT)
1090 if ((tcpb = intotcpcb(inpb)) != NULL) {
1091 tcp_reass_flush(tcpb);
1092 tcp_clean_sackreport(tcpb);
1096 INP_INFO_RUNLOCK(&V_tcbinfo);
1099 VNET_LIST_RUNLOCK_NOSLEEP();
1103 * Notify a tcp user of an asynchronous error;
1104 * store error as soft error, but wake up user
1105 * (for now, won't do anything until can select for soft error).
1107 * Do not wake up user since there currently is no mechanism for
1108 * reporting soft errors (yet - a kqueue filter may be added).
1110 static struct inpcb *
1111 tcp_notify(struct inpcb *inp, int error)
1115 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1116 INP_WLOCK_ASSERT(inp);
1118 if ((inp->inp_flags & INP_TIMEWAIT) ||
1119 (inp->inp_flags & INP_DROPPED))
1122 tp = intotcpcb(inp);
1123 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1126 * Ignore some errors if we are hooked up.
1127 * If connection hasn't completed, has retransmitted several times,
1128 * and receives a second error, give up now. This is better
1129 * than waiting a long time to establish a connection that
1130 * can never complete.
1132 if (tp->t_state == TCPS_ESTABLISHED &&
1133 (error == EHOSTUNREACH || error == ENETUNREACH ||
1134 error == EHOSTDOWN)) {
1136 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1138 tp = tcp_drop(tp, error);
1144 tp->t_softerror = error;
1148 wakeup( &so->so_timeo);
1155 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1157 int error, i, m, n, pcb_count;
1158 struct inpcb *inp, **inp_list;
1163 * The process of preparing the TCB list is too time-consuming and
1164 * resource-intensive to repeat twice on every request.
1166 if (req->oldptr == NULL) {
1167 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1168 n += imax(n / 8, 10);
1169 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1173 if (req->newptr != NULL)
1177 * OK, now we're committed to doing something.
1179 INP_INFO_RLOCK(&V_tcbinfo);
1180 gencnt = V_tcbinfo.ipi_gencnt;
1181 n = V_tcbinfo.ipi_count;
1182 INP_INFO_RUNLOCK(&V_tcbinfo);
1184 m = syncache_pcbcount();
1186 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1187 + (n + m) * sizeof(struct xtcpcb));
1191 xig.xig_len = sizeof xig;
1192 xig.xig_count = n + m;
1193 xig.xig_gen = gencnt;
1194 xig.xig_sogen = so_gencnt;
1195 error = SYSCTL_OUT(req, &xig, sizeof xig);
1199 error = syncache_pcblist(req, m, &pcb_count);
1203 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1204 if (inp_list == NULL)
1207 INP_INFO_RLOCK(&V_tcbinfo);
1208 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1209 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1211 if (inp->inp_gencnt <= gencnt) {
1213 * XXX: This use of cr_cansee(), introduced with
1214 * TCP state changes, is not quite right, but for
1215 * now, better than nothing.
1217 if (inp->inp_flags & INP_TIMEWAIT) {
1218 if (intotw(inp) != NULL)
1219 error = cr_cansee(req->td->td_ucred,
1220 intotw(inp)->tw_cred);
1222 error = EINVAL; /* Skip this inp. */
1224 error = cr_canseeinpcb(req->td->td_ucred, inp);
1227 inp_list[i++] = inp;
1232 INP_INFO_RUNLOCK(&V_tcbinfo);
1236 for (i = 0; i < n; i++) {
1239 if (inp->inp_gencnt <= gencnt) {
1243 bzero(&xt, sizeof(xt));
1244 xt.xt_len = sizeof xt;
1245 /* XXX should avoid extra copy */
1246 bcopy(inp, &xt.xt_inp, sizeof *inp);
1247 inp_ppcb = inp->inp_ppcb;
1248 if (inp_ppcb == NULL)
1249 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1250 else if (inp->inp_flags & INP_TIMEWAIT) {
1251 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1252 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1254 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1255 if (xt.xt_tp.t_timers)
1256 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1258 if (inp->inp_socket != NULL)
1259 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1261 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1262 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1264 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1266 error = SYSCTL_OUT(req, &xt, sizeof xt);
1270 INP_INFO_WLOCK(&V_tcbinfo);
1271 for (i = 0; i < n; i++) {
1274 if (!in_pcbrele_rlocked(inp))
1277 INP_INFO_WUNLOCK(&V_tcbinfo);
1281 * Give the user an updated idea of our state.
1282 * If the generation differs from what we told
1283 * her before, she knows that something happened
1284 * while we were processing this request, and it
1285 * might be necessary to retry.
1287 INP_INFO_RLOCK(&V_tcbinfo);
1288 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1289 xig.xig_sogen = so_gencnt;
1290 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1291 INP_INFO_RUNLOCK(&V_tcbinfo);
1292 error = SYSCTL_OUT(req, &xig, sizeof xig);
1294 free(inp_list, M_TEMP);
1298 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1299 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1300 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1304 tcp_getcred(SYSCTL_HANDLER_ARGS)
1307 struct sockaddr_in addrs[2];
1311 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1314 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1317 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1318 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1320 if (inp->inp_socket == NULL)
1323 error = cr_canseeinpcb(req->td->td_ucred, inp);
1325 cru2x(inp->inp_cred, &xuc);
1330 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1334 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1335 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1336 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1341 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1344 struct sockaddr_in6 addrs[2];
1351 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1354 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1357 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1358 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1361 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1363 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1372 inp = in_pcblookup(&V_tcbinfo,
1373 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1375 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1376 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1379 inp = in6_pcblookup(&V_tcbinfo,
1380 &addrs[1].sin6_addr, addrs[1].sin6_port,
1381 &addrs[0].sin6_addr, addrs[0].sin6_port,
1382 INPLOOKUP_RLOCKPCB, NULL);
1384 if (inp->inp_socket == NULL)
1387 error = cr_canseeinpcb(req->td->td_ucred, inp);
1389 cru2x(inp->inp_cred, &xuc);
1394 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1398 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1399 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1400 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1406 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1408 struct ip *ip = vip;
1410 struct in_addr faddr;
1413 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1415 struct in_conninfo inc;
1416 tcp_seq icmp_tcp_seq;
1419 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1420 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1423 if (cmd == PRC_MSGSIZE)
1424 notify = tcp_mtudisc_notify;
1425 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1426 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1427 notify = tcp_drop_syn_sent;
1429 * Redirects don't need to be handled up here.
1431 else if (PRC_IS_REDIRECT(cmd))
1434 * Source quench is depreciated.
1436 else if (cmd == PRC_QUENCH)
1439 * Hostdead is ugly because it goes linearly through all PCBs.
1440 * XXX: We never get this from ICMP, otherwise it makes an
1441 * excellent DoS attack on machines with many connections.
1443 else if (cmd == PRC_HOSTDEAD)
1445 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1448 icp = (struct icmp *)((caddr_t)ip
1449 - offsetof(struct icmp, icmp_ip));
1450 th = (struct tcphdr *)((caddr_t)ip
1451 + (ip->ip_hl << 2));
1452 INP_INFO_WLOCK(&V_tcbinfo);
1453 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1454 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1456 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1457 !(inp->inp_flags & INP_DROPPED) &&
1458 !(inp->inp_socket == NULL)) {
1459 icmp_tcp_seq = htonl(th->th_seq);
1460 tp = intotcpcb(inp);
1461 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1462 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1463 if (cmd == PRC_MSGSIZE) {
1466 * If we got a needfrag set the MTU
1467 * in the route to the suggested new
1468 * value (if given) and then notify.
1470 bzero(&inc, sizeof(inc));
1471 inc.inc_faddr = faddr;
1473 inp->inp_inc.inc_fibnum;
1475 mtu = ntohs(icp->icmp_nextmtu);
1477 * If no alternative MTU was
1478 * proposed, try the next smaller
1483 ntohs(ip->ip_len), 1);
1484 if (mtu < V_tcp_minmss
1485 + sizeof(struct tcpiphdr))
1487 + sizeof(struct tcpiphdr);
1489 * Only cache the MTU if it
1490 * is smaller than the interface
1491 * or route MTU. tcp_mtudisc()
1492 * will do right thing by itself.
1494 if (mtu <= tcp_maxmtu(&inc, NULL))
1495 tcp_hc_updatemtu(&inc, mtu);
1496 tcp_mtudisc(inp, mtu);
1498 inp = (*notify)(inp,
1499 inetctlerrmap[cmd]);
1505 bzero(&inc, sizeof(inc));
1506 inc.inc_fport = th->th_dport;
1507 inc.inc_lport = th->th_sport;
1508 inc.inc_faddr = faddr;
1509 inc.inc_laddr = ip->ip_src;
1510 syncache_unreach(&inc, th);
1512 INP_INFO_WUNLOCK(&V_tcbinfo);
1514 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1520 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1523 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1524 struct ip6_hdr *ip6;
1526 struct ip6ctlparam *ip6cp = NULL;
1527 const struct sockaddr_in6 *sa6_src = NULL;
1529 struct tcp_portonly {
1534 if (sa->sa_family != AF_INET6 ||
1535 sa->sa_len != sizeof(struct sockaddr_in6))
1538 if (cmd == PRC_MSGSIZE)
1539 notify = tcp_mtudisc_notify;
1540 else if (!PRC_IS_REDIRECT(cmd) &&
1541 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1543 /* Source quench is depreciated. */
1544 else if (cmd == PRC_QUENCH)
1547 /* if the parameter is from icmp6, decode it. */
1549 ip6cp = (struct ip6ctlparam *)d;
1551 ip6 = ip6cp->ip6c_ip6;
1552 off = ip6cp->ip6c_off;
1553 sa6_src = ip6cp->ip6c_src;
1557 off = 0; /* fool gcc */
1562 struct in_conninfo inc;
1564 * XXX: We assume that when IPV6 is non NULL,
1565 * M and OFF are valid.
1568 /* check if we can safely examine src and dst ports */
1569 if (m->m_pkthdr.len < off + sizeof(*thp))
1572 bzero(&th, sizeof(th));
1573 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1575 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1576 (struct sockaddr *)ip6cp->ip6c_src,
1577 th.th_sport, cmd, NULL, notify);
1579 bzero(&inc, sizeof(inc));
1580 inc.inc_fport = th.th_dport;
1581 inc.inc_lport = th.th_sport;
1582 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1583 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1584 inc.inc_flags |= INC_ISIPV6;
1585 INP_INFO_WLOCK(&V_tcbinfo);
1586 syncache_unreach(&inc, &th);
1587 INP_INFO_WUNLOCK(&V_tcbinfo);
1589 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1590 0, cmd, NULL, notify);
1596 * Following is where TCP initial sequence number generation occurs.
1598 * There are two places where we must use initial sequence numbers:
1599 * 1. In SYN-ACK packets.
1600 * 2. In SYN packets.
1602 * All ISNs for SYN-ACK packets are generated by the syncache. See
1603 * tcp_syncache.c for details.
1605 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1606 * depends on this property. In addition, these ISNs should be
1607 * unguessable so as to prevent connection hijacking. To satisfy
1608 * the requirements of this situation, the algorithm outlined in
1609 * RFC 1948 is used, with only small modifications.
1611 * Implementation details:
1613 * Time is based off the system timer, and is corrected so that it
1614 * increases by one megabyte per second. This allows for proper
1615 * recycling on high speed LANs while still leaving over an hour
1618 * As reading the *exact* system time is too expensive to be done
1619 * whenever setting up a TCP connection, we increment the time
1620 * offset in two ways. First, a small random positive increment
1621 * is added to isn_offset for each connection that is set up.
1622 * Second, the function tcp_isn_tick fires once per clock tick
1623 * and increments isn_offset as necessary so that sequence numbers
1624 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1625 * random positive increments serve only to ensure that the same
1626 * exact sequence number is never sent out twice (as could otherwise
1627 * happen when a port is recycled in less than the system tick
1630 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1631 * between seeding of isn_secret. This is normally set to zero,
1632 * as reseeding should not be necessary.
1634 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1635 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1636 * general, this means holding an exclusive (write) lock.
1639 #define ISN_BYTES_PER_SECOND 1048576
1640 #define ISN_STATIC_INCREMENT 4096
1641 #define ISN_RANDOM_INCREMENT (4096 - 1)
1643 static VNET_DEFINE(u_char, isn_secret[32]);
1644 static VNET_DEFINE(int, isn_last);
1645 static VNET_DEFINE(int, isn_last_reseed);
1646 static VNET_DEFINE(u_int32_t, isn_offset);
1647 static VNET_DEFINE(u_int32_t, isn_offset_old);
1649 #define V_isn_secret VNET(isn_secret)
1650 #define V_isn_last VNET(isn_last)
1651 #define V_isn_last_reseed VNET(isn_last_reseed)
1652 #define V_isn_offset VNET(isn_offset)
1653 #define V_isn_offset_old VNET(isn_offset_old)
1656 tcp_new_isn(struct tcpcb *tp)
1659 u_int32_t md5_buffer[4];
1661 u_int32_t projected_offset;
1663 INP_WLOCK_ASSERT(tp->t_inpcb);
1666 /* Seed if this is the first use, reseed if requested. */
1667 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1668 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1670 read_random(&V_isn_secret, sizeof(V_isn_secret));
1671 V_isn_last_reseed = ticks;
1674 /* Compute the md5 hash and return the ISN. */
1676 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1677 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1679 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1680 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1681 sizeof(struct in6_addr));
1682 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1683 sizeof(struct in6_addr));
1687 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1688 sizeof(struct in_addr));
1689 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1690 sizeof(struct in_addr));
1692 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1693 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1694 new_isn = (tcp_seq) md5_buffer[0];
1695 V_isn_offset += ISN_STATIC_INCREMENT +
1696 (arc4random() & ISN_RANDOM_INCREMENT);
1697 if (ticks != V_isn_last) {
1698 projected_offset = V_isn_offset_old +
1699 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1700 if (SEQ_GT(projected_offset, V_isn_offset))
1701 V_isn_offset = projected_offset;
1702 V_isn_offset_old = V_isn_offset;
1705 new_isn += V_isn_offset;
1711 * When a specific ICMP unreachable message is received and the
1712 * connection state is SYN-SENT, drop the connection. This behavior
1713 * is controlled by the icmp_may_rst sysctl.
1716 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1720 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1721 INP_WLOCK_ASSERT(inp);
1723 if ((inp->inp_flags & INP_TIMEWAIT) ||
1724 (inp->inp_flags & INP_DROPPED))
1727 tp = intotcpcb(inp);
1728 if (tp->t_state != TCPS_SYN_SENT)
1731 tp = tcp_drop(tp, errno);
1739 * When `need fragmentation' ICMP is received, update our idea of the MSS
1740 * based on the new value. Also nudge TCP to send something, since we
1741 * know the packet we just sent was dropped.
1742 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1744 static struct inpcb *
1745 tcp_mtudisc_notify(struct inpcb *inp, int error)
1748 return (tcp_mtudisc(inp, -1));
1752 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1757 INP_WLOCK_ASSERT(inp);
1758 if ((inp->inp_flags & INP_TIMEWAIT) ||
1759 (inp->inp_flags & INP_DROPPED))
1762 tp = intotcpcb(inp);
1763 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1765 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1767 so = inp->inp_socket;
1768 SOCKBUF_LOCK(&so->so_snd);
1769 /* If the mss is larger than the socket buffer, decrease the mss. */
1770 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1771 tp->t_maxseg = so->so_snd.sb_hiwat;
1772 SOCKBUF_UNLOCK(&so->so_snd);
1774 TCPSTAT_INC(tcps_mturesent);
1776 tp->snd_nxt = tp->snd_una;
1777 tcp_free_sackholes(tp);
1778 tp->snd_recover = tp->snd_max;
1779 if (tp->t_flags & TF_SACK_PERMIT)
1780 EXIT_FASTRECOVERY(tp->t_flags);
1787 * Look-up the routing entry to the peer of this inpcb. If no route
1788 * is found and it cannot be allocated, then return 0. This routine
1789 * is called by TCP routines that access the rmx structure and by
1790 * tcp_mss_update to get the peer/interface MTU.
1793 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1796 struct sockaddr_in *dst;
1800 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1802 bzero(&sro, sizeof(sro));
1803 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1804 dst = (struct sockaddr_in *)&sro.ro_dst;
1805 dst->sin_family = AF_INET;
1806 dst->sin_len = sizeof(*dst);
1807 dst->sin_addr = inc->inc_faddr;
1808 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1810 if (sro.ro_rt != NULL) {
1811 ifp = sro.ro_rt->rt_ifp;
1812 if (sro.ro_rt->rt_mtu == 0)
1813 maxmtu = ifp->if_mtu;
1815 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu);
1817 /* Report additional interface capabilities. */
1819 if (ifp->if_capenable & IFCAP_TSO4 &&
1820 ifp->if_hwassist & CSUM_TSO) {
1821 cap->ifcap |= CSUM_TSO;
1822 cap->tsomax = ifp->if_hw_tsomax;
1833 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1835 struct route_in6 sro6;
1839 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1841 bzero(&sro6, sizeof(sro6));
1842 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1843 sro6.ro_dst.sin6_family = AF_INET6;
1844 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1845 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1846 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1848 if (sro6.ro_rt != NULL) {
1849 ifp = sro6.ro_rt->rt_ifp;
1850 if (sro6.ro_rt->rt_mtu == 0)
1851 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1853 maxmtu = min(sro6.ro_rt->rt_mtu,
1854 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1856 /* Report additional interface capabilities. */
1858 if (ifp->if_capenable & IFCAP_TSO6 &&
1859 ifp->if_hwassist & CSUM_TSO) {
1860 cap->ifcap |= CSUM_TSO;
1861 cap->tsomax = ifp->if_hw_tsomax;
1872 /* compute ESP/AH header size for TCP, including outer IP header. */
1874 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1881 struct ip6_hdr *ip6;
1885 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1887 m = m_gethdr(M_NOWAIT, MT_DATA);
1892 if ((inp->inp_vflag & INP_IPV6) != 0) {
1893 ip6 = mtod(m, struct ip6_hdr *);
1894 th = (struct tcphdr *)(ip6 + 1);
1895 m->m_pkthdr.len = m->m_len =
1896 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1897 tcpip_fillheaders(inp, ip6, th);
1898 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1902 ip = mtod(m, struct ip *);
1903 th = (struct tcphdr *)(ip + 1);
1904 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1905 tcpip_fillheaders(inp, ip, th);
1906 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1914 #ifdef TCP_SIGNATURE
1916 * Callback function invoked by m_apply() to digest TCP segment data
1917 * contained within an mbuf chain.
1920 tcp_signature_apply(void *fstate, void *data, u_int len)
1923 MD5Update(fstate, (u_char *)data, len);
1928 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1931 * m pointer to head of mbuf chain
1933 * len length of TCP segment data, excluding options
1934 * optlen length of TCP segment options
1935 * buf pointer to storage for computed MD5 digest
1936 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1938 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1939 * When called from tcp_input(), we can be sure that th_sum has been
1940 * zeroed out and verified already.
1942 * Return 0 if successful, otherwise return -1.
1944 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1945 * search with the destination IP address, and a 'magic SPI' to be
1946 * determined by the application. This is hardcoded elsewhere to 1179
1947 * right now. Another branch of this code exists which uses the SPD to
1948 * specify per-application flows but it is unstable.
1951 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1952 u_char *buf, u_int direction)
1954 union sockaddr_union dst;
1956 struct ippseudo ippseudo;
1962 struct ipovly *ipovly;
1964 struct secasvar *sav;
1967 struct ip6_hdr *ip6;
1968 struct in6_addr in6;
1969 char ip6buf[INET6_ADDRSTRLEN];
1975 KASSERT(m != NULL, ("NULL mbuf chain"));
1976 KASSERT(buf != NULL, ("NULL signature pointer"));
1978 /* Extract the destination from the IP header in the mbuf. */
1979 bzero(&dst, sizeof(union sockaddr_union));
1980 ip = mtod(m, struct ip *);
1982 ip6 = NULL; /* Make the compiler happy. */
1987 dst.sa.sa_len = sizeof(struct sockaddr_in);
1988 dst.sa.sa_family = AF_INET;
1989 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1990 ip->ip_src : ip->ip_dst;
1994 case (IPV6_VERSION >> 4):
1995 ip6 = mtod(m, struct ip6_hdr *);
1996 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1997 dst.sa.sa_family = AF_INET6;
1998 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1999 ip6->ip6_src : ip6->ip6_dst;
2008 /* Look up an SADB entry which matches the address of the peer. */
2009 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
2011 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
2012 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
2014 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2015 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2023 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2025 * XXX The ippseudo header MUST be digested in network byte order,
2026 * or else we'll fail the regression test. Assume all fields we've
2027 * been doing arithmetic on have been in host byte order.
2028 * XXX One cannot depend on ipovly->ih_len here. When called from
2029 * tcp_output(), the underlying ip_len member has not yet been set.
2034 ipovly = (struct ipovly *)ip;
2035 ippseudo.ippseudo_src = ipovly->ih_src;
2036 ippseudo.ippseudo_dst = ipovly->ih_dst;
2037 ippseudo.ippseudo_pad = 0;
2038 ippseudo.ippseudo_p = IPPROTO_TCP;
2039 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2041 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2043 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2044 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2049 * RFC 2385, 2.0 Proposal
2050 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2051 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2052 * extended next header value (to form 32 bits), and 32-bit segment
2054 * Note: Upper-Layer Packet Length comes before Next Header.
2056 case (IPV6_VERSION >> 4):
2058 in6_clearscope(&in6);
2059 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2061 in6_clearscope(&in6);
2062 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2063 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2064 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2066 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2067 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2068 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2070 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2072 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2073 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2084 * Step 2: Update MD5 hash with TCP header, excluding options.
2085 * The TCP checksum must be set to zero.
2087 savecsum = th->th_sum;
2089 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2090 th->th_sum = savecsum;
2093 * Step 3: Update MD5 hash with TCP segment data.
2094 * Use m_apply() to avoid an early m_pullup().
2097 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2100 * Step 4: Update MD5 hash with shared secret.
2102 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2103 MD5Final(buf, &ctx);
2105 key_sa_recordxfer(sav, m);
2111 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2114 * m pointer to head of mbuf chain
2115 * len length of TCP segment data, excluding options
2116 * optlen length of TCP segment options
2117 * buf pointer to storage for computed MD5 digest
2118 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2120 * Return 1 if successful, otherwise return 0.
2123 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2124 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2126 char tmpdigest[TCP_SIGLEN];
2128 if (tcp_sig_checksigs == 0)
2130 if ((tcpbflag & TF_SIGNATURE) == 0) {
2131 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2134 * If this socket is not expecting signature but
2135 * the segment contains signature just fail.
2137 TCPSTAT_INC(tcps_sig_err_sigopt);
2138 TCPSTAT_INC(tcps_sig_rcvbadsig);
2142 /* Signature is not expected, and not present in segment. */
2147 * If this socket is expecting signature but the segment does not
2148 * contain any just fail.
2150 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2151 TCPSTAT_INC(tcps_sig_err_nosigopt);
2152 TCPSTAT_INC(tcps_sig_rcvbadsig);
2155 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2156 IPSEC_DIR_INBOUND) == -1) {
2157 TCPSTAT_INC(tcps_sig_err_buildsig);
2158 TCPSTAT_INC(tcps_sig_rcvbadsig);
2162 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2163 TCPSTAT_INC(tcps_sig_rcvbadsig);
2166 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2169 #endif /* TCP_SIGNATURE */
2172 sysctl_drop(SYSCTL_HANDLER_ARGS)
2174 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2175 struct sockaddr_storage addrs[2];
2179 struct sockaddr_in *fin, *lin;
2181 struct sockaddr_in6 *fin6, *lin6;
2192 if (req->oldptr != NULL || req->oldlen != 0)
2194 if (req->newptr == NULL)
2196 if (req->newlen < sizeof(addrs))
2198 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2202 switch (addrs[0].ss_family) {
2205 fin6 = (struct sockaddr_in6 *)&addrs[0];
2206 lin6 = (struct sockaddr_in6 *)&addrs[1];
2207 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2208 lin6->sin6_len != sizeof(struct sockaddr_in6))
2210 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2211 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2213 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2214 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2215 fin = (struct sockaddr_in *)&addrs[0];
2216 lin = (struct sockaddr_in *)&addrs[1];
2219 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2222 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2229 fin = (struct sockaddr_in *)&addrs[0];
2230 lin = (struct sockaddr_in *)&addrs[1];
2231 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2232 lin->sin_len != sizeof(struct sockaddr_in))
2239 INP_INFO_WLOCK(&V_tcbinfo);
2240 switch (addrs[0].ss_family) {
2243 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2244 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2245 INPLOOKUP_WLOCKPCB, NULL);
2250 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2251 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2256 if (inp->inp_flags & INP_TIMEWAIT) {
2258 * XXXRW: There currently exists a state where an
2259 * inpcb is present, but its timewait state has been
2260 * discarded. For now, don't allow dropping of this
2268 } else if (!(inp->inp_flags & INP_DROPPED) &&
2269 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2270 tp = intotcpcb(inp);
2271 tp = tcp_drop(tp, ECONNABORTED);
2278 INP_INFO_WUNLOCK(&V_tcbinfo);
2282 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2283 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2284 0, sysctl_drop, "", "Drop TCP connection");
2287 * Generate a standardized TCP log line for use throughout the
2288 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2289 * allow use in the interrupt context.
2291 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2292 * NB: The function may return NULL if memory allocation failed.
2294 * Due to header inclusion and ordering limitations the struct ip
2295 * and ip6_hdr pointers have to be passed as void pointers.
2298 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2302 /* Is logging enabled? */
2303 if (tcp_log_in_vain == 0)
2306 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2310 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2314 /* Is logging enabled? */
2315 if (tcp_log_debug == 0)
2318 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2322 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2329 const struct ip6_hdr *ip6;
2331 ip6 = (const struct ip6_hdr *)ip6hdr;
2333 ip = (struct ip *)ip4hdr;
2336 * The log line looks like this:
2337 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2339 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2340 sizeof(PRINT_TH_FLAGS) + 1 +
2342 2 * INET6_ADDRSTRLEN;
2344 2 * INET_ADDRSTRLEN;
2347 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2351 strcat(s, "TCP: [");
2354 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2355 inet_ntoa_r(inc->inc_faddr, sp);
2357 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2359 inet_ntoa_r(inc->inc_laddr, sp);
2361 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2364 ip6_sprintf(sp, &inc->inc6_faddr);
2366 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2368 ip6_sprintf(sp, &inc->inc6_laddr);
2370 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2371 } else if (ip6 && th) {
2372 ip6_sprintf(sp, &ip6->ip6_src);
2374 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2376 ip6_sprintf(sp, &ip6->ip6_dst);
2378 sprintf(sp, "]:%i", ntohs(th->th_dport));
2381 } else if (ip && th) {
2382 inet_ntoa_r(ip->ip_src, sp);
2384 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2386 inet_ntoa_r(ip->ip_dst, sp);
2388 sprintf(sp, "]:%i", ntohs(th->th_dport));
2396 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2397 if (*(s + size - 1) != '\0')
2398 panic("%s: string too long", __func__);
2403 * A subroutine which makes it easy to track TCP state changes with DTrace.
2404 * This function shouldn't be called for t_state initializations that don't
2405 * correspond to actual TCP state transitions.
2408 tcp_state_change(struct tcpcb *tp, int newstate)
2410 #if defined(KDTRACE_HOOKS)
2411 int pstate = tp->t_state;
2414 tp->t_state = newstate;
2415 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);