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>
87 #include <netinet/tcp_fastopen.h>
89 #include <netinet/tcp_fsm.h>
90 #include <netinet/tcp_seq.h>
91 #include <netinet/tcp_timer.h>
92 #include <netinet/tcp_var.h>
93 #include <netinet/tcp_syncache.h>
95 #include <netinet6/tcp6_var.h>
97 #include <netinet/tcpip.h>
99 #include <netinet/tcp_debug.h>
102 #include <netinet6/ip6protosw.h>
105 #include <netinet/tcp_offload.h>
109 #include <netipsec/ipsec.h>
110 #include <netipsec/xform.h>
112 #include <netipsec/ipsec6.h>
114 #include <netipsec/key.h>
115 #include <sys/syslog.h>
118 #include <machine/in_cksum.h>
121 #include <security/mac/mac_framework.h>
123 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
125 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
129 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
134 error = sysctl_handle_int(oidp, &new, 0, req);
135 if (error == 0 && req->newptr) {
136 if (new < TCP_MINMSS)
144 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
145 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
146 &sysctl_net_inet_tcp_mss_check, "I",
147 "Default TCP Maximum Segment Size");
151 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
155 new = V_tcp_v6mssdflt;
156 error = sysctl_handle_int(oidp, &new, 0, req);
157 if (error == 0 && req->newptr) {
158 if (new < TCP_MINMSS)
161 V_tcp_v6mssdflt = new;
166 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
167 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
168 &sysctl_net_inet_tcp_mss_v6_check, "I",
169 "Default TCP Maximum Segment Size for IPv6");
173 * Minimum MSS we accept and use. This prevents DoS attacks where
174 * we are forced to a ridiculous low MSS like 20 and send hundreds
175 * of packets instead of one. The effect scales with the available
176 * bandwidth and quickly saturates the CPU and network interface
177 * with packet generation and sending. Set to zero to disable MINMSS
178 * checking. This setting prevents us from sending too small packets.
180 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
181 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
182 &VNET_NAME(tcp_minmss), 0,
183 "Minimum TCP Maximum Segment Size");
185 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
186 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
187 &VNET_NAME(tcp_do_rfc1323), 0,
188 "Enable rfc1323 (high performance TCP) extensions");
190 static int tcp_log_debug = 0;
191 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
192 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
194 static int tcp_tcbhashsize = 0;
195 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
196 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
198 static int do_tcpdrain = 1;
199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
200 "Enable tcp_drain routine for extra help when low on mbufs");
202 SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
203 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
205 static VNET_DEFINE(int, icmp_may_rst) = 1;
206 #define V_icmp_may_rst VNET(icmp_may_rst)
207 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
208 &VNET_NAME(icmp_may_rst), 0,
209 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
211 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
212 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
213 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
214 &VNET_NAME(tcp_isn_reseed_interval), 0,
215 "Seconds between reseeding of ISN secret");
217 static int tcp_soreceive_stream = 0;
218 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
219 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
222 static int tcp_sig_checksigs = 1;
223 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW,
224 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic");
227 VNET_DEFINE(uma_zone_t, sack_hole_zone);
228 #define V_sack_hole_zone VNET(sack_hole_zone)
230 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
232 static struct inpcb *tcp_notify(struct inpcb *, int);
233 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
234 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
235 void *ip4hdr, const void *ip6hdr);
236 static void tcp_timer_discard(struct tcpcb *, uint32_t);
239 * Target size of TCP PCB hash tables. Must be a power of two.
241 * Note that this can be overridden by the kernel environment
242 * variable net.inet.tcp.tcbhashsize
245 #define TCBHASHSIZE 0
250 * Callouts should be moved into struct tcp directly. They are currently
251 * separate because the tcpcb structure is exported to userland for sysctl
252 * parsing purposes, which do not know about callouts.
261 static VNET_DEFINE(uma_zone_t, tcpcb_zone);
262 #define V_tcpcb_zone VNET(tcpcb_zone)
264 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
265 static struct mtx isn_mtx;
267 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
268 #define ISN_LOCK() mtx_lock(&isn_mtx)
269 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
272 * TCP initialization.
275 tcp_zone_change(void *tag)
278 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
279 uma_zone_set_max(V_tcpcb_zone, maxsockets);
280 tcp_tw_zone_change();
284 tcp_inpcb_init(void *mem, int size, int flags)
286 struct inpcb *inp = mem;
288 INP_LOCK_INIT(inp, "inp", "tcpinp");
293 * Take a value and get the next power of 2 that doesn't overflow.
294 * Used to size the tcp_inpcb hash buckets.
297 maketcp_hashsize(int size)
303 * get the next power of 2 higher than maxsockets.
305 hashsize = 1 << fls(size);
306 /* catch overflow, and just go one power of 2 smaller */
307 if (hashsize < size) {
308 hashsize = 1 << (fls(size) - 1);
316 const char *tcbhash_tuneable;
319 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
321 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
322 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
323 printf("%s: WARNING: unable to register helper hook\n", __func__);
324 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
325 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
326 printf("%s: WARNING: unable to register helper hook\n", __func__);
328 hashsize = TCBHASHSIZE;
329 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
332 * Auto tune the hash size based on maxsockets.
333 * A perfect hash would have a 1:1 mapping
334 * (hashsize = maxsockets) however it's been
335 * suggested that O(2) average is better.
337 hashsize = maketcp_hashsize(maxsockets / 4);
339 * Our historical default is 512,
340 * do not autotune lower than this.
344 if (bootverbose && IS_DEFAULT_VNET(curvnet))
345 printf("%s: %s auto tuned to %d\n", __func__,
346 tcbhash_tuneable, hashsize);
349 * We require a hashsize to be a power of two.
350 * Previously if it was not a power of two we would just reset it
351 * back to 512, which could be a nasty surprise if you did not notice
353 * Instead what we do is clip it to the closest power of two lower
354 * than the specified hash value.
356 if (!powerof2(hashsize)) {
357 int oldhashsize = hashsize;
359 hashsize = maketcp_hashsize(hashsize);
360 /* prevent absurdly low value */
363 printf("%s: WARNING: TCB hash size not a power of 2, "
364 "clipped from %d to %d.\n", __func__, oldhashsize,
367 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
368 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
369 IPI_HASHFIELDS_4TUPLE);
372 * These have to be type stable for the benefit of the timers.
374 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
375 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
376 uma_zone_set_max(V_tcpcb_zone, maxsockets);
377 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
383 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
384 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
385 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
387 /* Skip initialization of globals for non-default instances. */
388 if (!IS_DEFAULT_VNET(curvnet))
391 tcp_reass_global_init();
393 /* XXX virtualize those bellow? */
394 tcp_delacktime = TCPTV_DELACK;
395 tcp_keepinit = TCPTV_KEEP_INIT;
396 tcp_keepidle = TCPTV_KEEP_IDLE;
397 tcp_keepintvl = TCPTV_KEEPINTVL;
398 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
400 tcp_rexmit_min = TCPTV_MIN;
401 if (tcp_rexmit_min < 1)
403 tcp_persmin = TCPTV_PERSMIN;
404 tcp_persmax = TCPTV_PERSMAX;
405 tcp_rexmit_slop = TCPTV_CPU_VAR;
406 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
407 tcp_tcbhashsize = hashsize;
409 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
410 if (tcp_soreceive_stream) {
412 tcp_usrreqs.pru_soreceive = soreceive_stream;
415 tcp6_usrreqs.pru_soreceive = soreceive_stream;
420 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
422 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
424 if (max_protohdr < TCP_MINPROTOHDR)
425 max_protohdr = TCP_MINPROTOHDR;
426 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
428 #undef TCP_MINPROTOHDR
431 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
432 SHUTDOWN_PRI_DEFAULT);
433 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
434 EVENTHANDLER_PRI_ANY);
447 tcp_fastopen_destroy();
452 in_pcbinfo_destroy(&V_tcbinfo);
453 uma_zdestroy(V_sack_hole_zone);
454 uma_zdestroy(V_tcpcb_zone);
465 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
466 * tcp_template used to store this data in mbufs, but we now recopy it out
467 * of the tcpcb each time to conserve mbufs.
470 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
472 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
474 INP_WLOCK_ASSERT(inp);
477 if ((inp->inp_vflag & INP_IPV6) != 0) {
480 ip6 = (struct ip6_hdr *)ip_ptr;
481 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
482 (inp->inp_flow & IPV6_FLOWINFO_MASK);
483 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
484 (IPV6_VERSION & IPV6_VERSION_MASK);
485 ip6->ip6_nxt = IPPROTO_TCP;
486 ip6->ip6_plen = htons(sizeof(struct tcphdr));
487 ip6->ip6_src = inp->in6p_laddr;
488 ip6->ip6_dst = inp->in6p_faddr;
491 #if defined(INET6) && defined(INET)
498 ip = (struct ip *)ip_ptr;
499 ip->ip_v = IPVERSION;
501 ip->ip_tos = inp->inp_ip_tos;
505 ip->ip_ttl = inp->inp_ip_ttl;
507 ip->ip_p = IPPROTO_TCP;
508 ip->ip_src = inp->inp_laddr;
509 ip->ip_dst = inp->inp_faddr;
512 th->th_sport = inp->inp_lport;
513 th->th_dport = inp->inp_fport;
521 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
525 * Create template to be used to send tcp packets on a connection.
526 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
527 * use for this function is in keepalives, which use tcp_respond.
530 tcpip_maketemplate(struct inpcb *inp)
534 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
537 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
542 * Send a single message to the TCP at address specified by
543 * the given TCP/IP header. If m == NULL, then we make a copy
544 * of the tcpiphdr at ti and send directly to the addressed host.
545 * This is used to force keep alive messages out using the TCP
546 * template for a connection. If flags are given then we send
547 * a message back to the TCP which originated the * segment ti,
548 * and discard the mbuf containing it and any other attached mbufs.
550 * In any case the ack and sequence number of the transmitted
551 * segment are as specified by the parameters.
553 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
556 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
557 tcp_seq ack, tcp_seq seq, int flags)
569 int optlen, tlen, win;
572 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
575 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
582 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
583 INP_WLOCK_ASSERT(inp);
590 if (!(flags & TH_RST)) {
591 win = sbspace(&inp->inp_socket->so_rcv);
592 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
593 win = (long)TCP_MAXWIN << tp->rcv_scale;
595 if ((tp->t_flags & TF_NOOPT) == 0)
599 m = m_gethdr(M_NOWAIT, MT_DATA);
602 m->m_data += max_linkhdr;
605 bcopy((caddr_t)ip6, mtod(m, caddr_t),
606 sizeof(struct ip6_hdr));
607 ip6 = mtod(m, struct ip6_hdr *);
608 nth = (struct tcphdr *)(ip6 + 1);
612 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
613 ip = mtod(m, struct ip *);
614 nth = (struct tcphdr *)(ip + 1);
616 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
618 } else if (!M_WRITABLE(m)) {
621 /* Can't reuse 'm', allocate a new mbuf. */
622 n = m_gethdr(M_NOWAIT, MT_DATA);
628 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
634 n->m_data += max_linkhdr;
635 /* m_len is set later */
636 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
639 bcopy((caddr_t)ip6, mtod(n, caddr_t),
640 sizeof(struct ip6_hdr));
641 ip6 = mtod(n, struct ip6_hdr *);
642 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
643 nth = (struct tcphdr *)(ip6 + 1);
647 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip));
648 ip = mtod(n, struct ip *);
649 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
650 nth = (struct tcphdr *)(ip + 1);
652 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
653 xchg(nth->th_dport, nth->th_sport, uint16_t);
660 * XXX MRT We inherit the FIB, which is lucky.
664 m->m_data = (caddr_t)ipgen;
665 /* m_len is set later */
668 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
669 nth = (struct tcphdr *)(ip6 + 1);
673 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
674 nth = (struct tcphdr *)(ip + 1);
678 * this is usually a case when an extension header
679 * exists between the IPv6 header and the
682 nth->th_sport = th->th_sport;
683 nth->th_dport = th->th_dport;
685 xchg(nth->th_dport, nth->th_sport, uint16_t);
691 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
693 #if defined(INET) && defined(INET6)
697 tlen = sizeof (struct tcpiphdr);
701 KASSERT(M_TRAILINGSPACE(m) >= tlen,
702 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)",
703 m, tlen, (long)M_TRAILINGSPACE(m)));
708 /* Make sure we have room. */
709 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) {
710 m->m_next = m_get(M_NOWAIT, MT_DATA);
712 optp = mtod(m->m_next, u_char *);
717 optp = (u_char *) (nth + 1);
723 if (tp->t_flags & TF_RCVD_TSTMP) {
724 to.to_tsval = tcp_ts_getticks() + tp->ts_offset;
725 to.to_tsecr = tp->ts_recent;
726 to.to_flags |= TOF_TS;
729 /* TCP-MD5 (RFC2385). */
730 if (tp->t_flags & TF_SIGNATURE)
731 to.to_flags |= TOF_SIGNATURE;
734 /* Add the options. */
735 tlen += optlen = tcp_addoptions(&to, optp);
737 /* Update m_len in the correct mbuf. */
738 optm->m_len += optlen;
744 ip6->ip6_vfc = IPV6_VERSION;
745 ip6->ip6_nxt = IPPROTO_TCP;
746 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
749 #if defined(INET) && defined(INET6)
754 ip->ip_len = htons(tlen);
755 ip->ip_ttl = V_ip_defttl;
756 if (V_path_mtu_discovery)
757 ip->ip_off |= htons(IP_DF);
760 m->m_pkthdr.len = tlen;
761 m->m_pkthdr.rcvif = NULL;
765 * Packet is associated with a socket, so allow the
766 * label of the response to reflect the socket label.
768 INP_WLOCK_ASSERT(inp);
769 mac_inpcb_create_mbuf(inp, m);
772 * Packet is not associated with a socket, so possibly
773 * update the label in place.
775 mac_netinet_tcp_reply(m);
778 nth->th_seq = htonl(seq);
779 nth->th_ack = htonl(ack);
781 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
782 nth->th_flags = flags;
784 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
786 nth->th_win = htons((u_short)win);
790 if (to.to_flags & TOF_SIGNATURE) {
791 tcp_signature_compute(m, 0, 0, optlen, to.to_signature,
796 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
799 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
800 nth->th_sum = in6_cksum_pseudo(ip6,
801 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
802 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
806 #if defined(INET6) && defined(INET)
811 m->m_pkthdr.csum_flags = CSUM_TCP;
812 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
813 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
817 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
818 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
821 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *),
824 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth);
827 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp);
829 #if defined(INET) && defined(INET6)
833 (void) ip_output(m, NULL, NULL, 0, NULL, inp);
838 * Create a new TCP control block, making an
839 * empty reassembly queue and hooking it to the argument
840 * protocol control block. The `inp' parameter must have
841 * come from the zone allocator set up in tcp_init().
844 tcp_newtcpcb(struct inpcb *inp)
846 struct tcpcb_mem *tm;
849 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
852 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
857 /* Initialise cc_var struct for this tcpcb. */
859 tp->ccv->type = IPPROTO_TCP;
860 tp->ccv->ccvc.tcp = tp;
863 * Use the current system default CC algorithm.
866 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
867 CC_ALGO(tp) = CC_DEFAULT();
870 if (CC_ALGO(tp)->cb_init != NULL)
871 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
872 uma_zfree(V_tcpcb_zone, tm);
877 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
878 uma_zfree(V_tcpcb_zone, tm);
883 tp->t_vnet = inp->inp_vnet;
885 tp->t_timers = &tm->tt;
886 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
887 tp->t_maxseg = tp->t_maxopd =
889 isipv6 ? V_tcp_v6mssdflt :
893 /* Set up our timeouts. */
894 callout_init(&tp->t_timers->tt_rexmt, 1);
895 callout_init(&tp->t_timers->tt_persist, 1);
896 callout_init(&tp->t_timers->tt_keep, 1);
897 callout_init(&tp->t_timers->tt_2msl, 1);
898 callout_init(&tp->t_timers->tt_delack, 1);
900 if (V_tcp_do_rfc1323)
901 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
903 tp->t_flags |= TF_SACK_PERMIT;
904 TAILQ_INIT(&tp->snd_holes);
906 * The tcpcb will hold a reference on its inpcb until tcp_discardcb()
909 in_pcbref(inp); /* Reference for tcpcb */
913 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
914 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
915 * reasonable initial retransmit time.
917 tp->t_srtt = TCPTV_SRTTBASE;
918 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
919 tp->t_rttmin = tcp_rexmit_min;
920 tp->t_rxtcur = TCPTV_RTOBASE;
921 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
922 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
923 tp->t_rcvtime = ticks;
925 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
926 * because the socket may be bound to an IPv6 wildcard address,
927 * which may match an IPv4-mapped IPv6 address.
929 inp->inp_ip_ttl = V_ip_defttl;
931 return (tp); /* XXX */
935 * Switch the congestion control algorithm back to NewReno for any active
936 * control blocks using an algorithm which is about to go away.
937 * This ensures the CC framework can allow the unload to proceed without leaving
938 * any dangling pointers which would trigger a panic.
939 * Returning non-zero would inform the CC framework that something went wrong
940 * and it would be unsafe to allow the unload to proceed. However, there is no
941 * way for this to occur with this implementation so we always return zero.
944 tcp_ccalgounload(struct cc_algo *unload_algo)
946 struct cc_algo *tmpalgo;
949 VNET_ITERATOR_DECL(vnet_iter);
952 * Check all active control blocks across all network stacks and change
953 * any that are using "unload_algo" back to NewReno. If "unload_algo"
954 * requires cleanup code to be run, call it.
957 VNET_FOREACH(vnet_iter) {
958 CURVNET_SET(vnet_iter);
959 INP_INFO_WLOCK(&V_tcbinfo);
961 * New connections already part way through being initialised
962 * with the CC algo we're removing will not race with this code
963 * because the INP_INFO_WLOCK is held during initialisation. We
964 * therefore don't enter the loop below until the connection
965 * list has stabilised.
967 LIST_FOREACH(inp, &V_tcb, inp_list) {
969 /* Important to skip tcptw structs. */
970 if (!(inp->inp_flags & INP_TIMEWAIT) &&
971 (tp = intotcpcb(inp)) != NULL) {
973 * By holding INP_WLOCK here, we are assured
974 * that the connection is not currently
975 * executing inside the CC module's functions
976 * i.e. it is safe to make the switch back to
979 if (CC_ALGO(tp) == unload_algo) {
980 tmpalgo = CC_ALGO(tp);
981 /* NewReno does not require any init. */
982 CC_ALGO(tp) = &newreno_cc_algo;
983 if (tmpalgo->cb_destroy != NULL)
984 tmpalgo->cb_destroy(tp->ccv);
989 INP_INFO_WUNLOCK(&V_tcbinfo);
998 * Drop a TCP connection, reporting
999 * the specified error. If connection is synchronized,
1000 * then send a RST to peer.
1003 tcp_drop(struct tcpcb *tp, int errno)
1005 struct socket *so = tp->t_inpcb->inp_socket;
1007 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1008 INP_WLOCK_ASSERT(tp->t_inpcb);
1010 if (TCPS_HAVERCVDSYN(tp->t_state)) {
1011 tcp_state_change(tp, TCPS_CLOSED);
1012 (void) tcp_output(tp);
1013 TCPSTAT_INC(tcps_drops);
1015 TCPSTAT_INC(tcps_conndrops);
1016 if (errno == ETIMEDOUT && tp->t_softerror)
1017 errno = tp->t_softerror;
1018 so->so_error = errno;
1019 return (tcp_close(tp));
1023 tcp_discardcb(struct tcpcb *tp)
1025 struct inpcb *inp = tp->t_inpcb;
1026 struct socket *so = inp->inp_socket;
1028 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
1032 INP_WLOCK_ASSERT(inp);
1035 * Make sure that all of our timers are stopped before we delete the
1038 * If stopping a timer fails, we schedule a discard function in same
1039 * callout, and the last discard function called will take care of
1040 * deleting the tcpcb.
1042 tcp_timer_stop(tp, TT_REXMT);
1043 tcp_timer_stop(tp, TT_PERSIST);
1044 tcp_timer_stop(tp, TT_KEEP);
1045 tcp_timer_stop(tp, TT_2MSL);
1046 tcp_timer_stop(tp, TT_DELACK);
1049 * If we got enough samples through the srtt filter,
1050 * save the rtt and rttvar in the routing entry.
1051 * 'Enough' is arbitrarily defined as 4 rtt samples.
1052 * 4 samples is enough for the srtt filter to converge
1053 * to within enough % of the correct value; fewer samples
1054 * and we could save a bogus rtt. The danger is not high
1055 * as tcp quickly recovers from everything.
1056 * XXX: Works very well but needs some more statistics!
1058 if (tp->t_rttupdated >= 4) {
1059 struct hc_metrics_lite metrics;
1062 bzero(&metrics, sizeof(metrics));
1064 * Update the ssthresh always when the conditions below
1065 * are satisfied. This gives us better new start value
1066 * for the congestion avoidance for new connections.
1067 * ssthresh is only set if packet loss occured on a session.
1069 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
1070 * being torn down. Ideally this code would not use 'so'.
1072 ssthresh = tp->snd_ssthresh;
1073 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
1075 * convert the limit from user data bytes to
1076 * packets then to packet data bytes.
1078 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
1081 ssthresh *= (u_long)(tp->t_maxseg +
1083 (isipv6 ? sizeof (struct ip6_hdr) +
1084 sizeof (struct tcphdr) :
1086 sizeof (struct tcpiphdr)
1093 metrics.rmx_ssthresh = ssthresh;
1095 metrics.rmx_rtt = tp->t_srtt;
1096 metrics.rmx_rttvar = tp->t_rttvar;
1097 metrics.rmx_cwnd = tp->snd_cwnd;
1098 metrics.rmx_sendpipe = 0;
1099 metrics.rmx_recvpipe = 0;
1101 tcp_hc_update(&inp->inp_inc, &metrics);
1104 /* free the reassembly queue, if any */
1105 tcp_reass_flush(tp);
1108 /* Disconnect offload device, if any. */
1109 if (tp->t_flags & TF_TOE)
1110 tcp_offload_detach(tp);
1113 tcp_free_sackholes(tp);
1115 /* Allow the CC algorithm to clean up after itself. */
1116 if (CC_ALGO(tp)->cb_destroy != NULL)
1117 CC_ALGO(tp)->cb_destroy(tp->ccv);
1119 khelp_destroy_osd(tp->osd);
1122 inp->inp_ppcb = NULL;
1123 if ((tp->t_timers->tt_flags & TT_MASK) == 0) {
1124 /* We own the last reference on tcpcb, let's free it. */
1126 uma_zfree(V_tcpcb_zone, tp);
1127 released = in_pcbrele_wlocked(inp);
1128 KASSERT(!released, ("%s: inp %p should not have been released "
1129 "here", __func__, inp));
1134 tcp_timer_2msl_discard(void *xtp)
1137 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL);
1141 tcp_timer_keep_discard(void *xtp)
1144 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP);
1148 tcp_timer_persist_discard(void *xtp)
1151 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST);
1155 tcp_timer_rexmt_discard(void *xtp)
1158 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT);
1162 tcp_timer_delack_discard(void *xtp)
1165 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK);
1169 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type)
1173 CURVNET_SET(tp->t_vnet);
1174 INP_INFO_RLOCK(&V_tcbinfo);
1176 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL",
1179 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0,
1180 ("%s: tcpcb has to be stopped here", __func__));
1181 KASSERT((tp->t_timers->tt_flags & timer_type) != 0,
1182 ("%s: discard callout should be running", __func__));
1183 tp->t_timers->tt_flags &= ~timer_type;
1184 if ((tp->t_timers->tt_flags & TT_MASK) == 0) {
1185 /* We own the last reference on this tcpcb, let's free it. */
1187 uma_zfree(V_tcpcb_zone, tp);
1188 if (in_pcbrele_wlocked(inp)) {
1189 INP_INFO_RUNLOCK(&V_tcbinfo);
1195 INP_INFO_RUNLOCK(&V_tcbinfo);
1200 * Attempt to close a TCP control block, marking it as dropped, and freeing
1201 * the socket if we hold the only reference.
1204 tcp_close(struct tcpcb *tp)
1206 struct inpcb *inp = tp->t_inpcb;
1209 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1210 INP_WLOCK_ASSERT(inp);
1213 if (tp->t_state == TCPS_LISTEN)
1214 tcp_offload_listen_stop(tp);
1218 * This releases the TFO pending counter resource for TFO listen
1219 * sockets as well as passively-created TFO sockets that transition
1220 * from SYN_RECEIVED to CLOSED.
1222 if (tp->t_tfo_pending) {
1223 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
1224 tp->t_tfo_pending = NULL;
1228 TCPSTAT_INC(tcps_closed);
1229 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1230 so = inp->inp_socket;
1231 soisdisconnected(so);
1232 if (inp->inp_flags & INP_SOCKREF) {
1233 KASSERT(so->so_state & SS_PROTOREF,
1234 ("tcp_close: !SS_PROTOREF"));
1235 inp->inp_flags &= ~INP_SOCKREF;
1239 so->so_state &= ~SS_PROTOREF;
1249 VNET_ITERATOR_DECL(vnet_iter);
1254 VNET_LIST_RLOCK_NOSLEEP();
1255 VNET_FOREACH(vnet_iter) {
1256 CURVNET_SET(vnet_iter);
1261 * Walk the tcpbs, if existing, and flush the reassembly queue,
1262 * if there is one...
1263 * XXX: The "Net/3" implementation doesn't imply that the TCP
1264 * reassembly queue should be flushed, but in a situation
1265 * where we're really low on mbufs, this is potentially
1268 INP_INFO_WLOCK(&V_tcbinfo);
1269 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1270 if (inpb->inp_flags & INP_TIMEWAIT)
1273 if ((tcpb = intotcpcb(inpb)) != NULL) {
1274 tcp_reass_flush(tcpb);
1275 tcp_clean_sackreport(tcpb);
1279 INP_INFO_WUNLOCK(&V_tcbinfo);
1282 VNET_LIST_RUNLOCK_NOSLEEP();
1286 * Notify a tcp user of an asynchronous error;
1287 * store error as soft error, but wake up user
1288 * (for now, won't do anything until can select for soft error).
1290 * Do not wake up user since there currently is no mechanism for
1291 * reporting soft errors (yet - a kqueue filter may be added).
1293 static struct inpcb *
1294 tcp_notify(struct inpcb *inp, int error)
1298 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1299 INP_WLOCK_ASSERT(inp);
1301 if ((inp->inp_flags & INP_TIMEWAIT) ||
1302 (inp->inp_flags & INP_DROPPED))
1305 tp = intotcpcb(inp);
1306 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1309 * Ignore some errors if we are hooked up.
1310 * If connection hasn't completed, has retransmitted several times,
1311 * and receives a second error, give up now. This is better
1312 * than waiting a long time to establish a connection that
1313 * can never complete.
1315 if (tp->t_state == TCPS_ESTABLISHED &&
1316 (error == EHOSTUNREACH || error == ENETUNREACH ||
1317 error == EHOSTDOWN)) {
1319 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1321 tp = tcp_drop(tp, error);
1327 tp->t_softerror = error;
1331 wakeup( &so->so_timeo);
1338 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1340 int error, i, m, n, pcb_count;
1341 struct inpcb *inp, **inp_list;
1346 * The process of preparing the TCB list is too time-consuming and
1347 * resource-intensive to repeat twice on every request.
1349 if (req->oldptr == NULL) {
1350 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1351 n += imax(n / 8, 10);
1352 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1356 if (req->newptr != NULL)
1360 * OK, now we're committed to doing something.
1362 INP_LIST_RLOCK(&V_tcbinfo);
1363 gencnt = V_tcbinfo.ipi_gencnt;
1364 n = V_tcbinfo.ipi_count;
1365 INP_LIST_RUNLOCK(&V_tcbinfo);
1367 m = syncache_pcbcount();
1369 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1370 + (n + m) * sizeof(struct xtcpcb));
1374 xig.xig_len = sizeof xig;
1375 xig.xig_count = n + m;
1376 xig.xig_gen = gencnt;
1377 xig.xig_sogen = so_gencnt;
1378 error = SYSCTL_OUT(req, &xig, sizeof xig);
1382 error = syncache_pcblist(req, m, &pcb_count);
1386 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1388 INP_INFO_WLOCK(&V_tcbinfo);
1389 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1390 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1392 if (inp->inp_gencnt <= gencnt) {
1394 * XXX: This use of cr_cansee(), introduced with
1395 * TCP state changes, is not quite right, but for
1396 * now, better than nothing.
1398 if (inp->inp_flags & INP_TIMEWAIT) {
1399 if (intotw(inp) != NULL)
1400 error = cr_cansee(req->td->td_ucred,
1401 intotw(inp)->tw_cred);
1403 error = EINVAL; /* Skip this inp. */
1405 error = cr_canseeinpcb(req->td->td_ucred, inp);
1408 inp_list[i++] = inp;
1413 INP_INFO_WUNLOCK(&V_tcbinfo);
1417 for (i = 0; i < n; i++) {
1420 if (inp->inp_gencnt <= gencnt) {
1424 bzero(&xt, sizeof(xt));
1425 xt.xt_len = sizeof xt;
1426 /* XXX should avoid extra copy */
1427 bcopy(inp, &xt.xt_inp, sizeof *inp);
1428 inp_ppcb = inp->inp_ppcb;
1429 if (inp_ppcb == NULL)
1430 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1431 else if (inp->inp_flags & INP_TIMEWAIT) {
1432 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1433 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1435 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1436 if (xt.xt_tp.t_timers)
1437 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1439 if (inp->inp_socket != NULL)
1440 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1442 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1443 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1445 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1447 error = SYSCTL_OUT(req, &xt, sizeof xt);
1451 INP_INFO_RLOCK(&V_tcbinfo);
1452 for (i = 0; i < n; i++) {
1455 if (!in_pcbrele_rlocked(inp))
1458 INP_INFO_RUNLOCK(&V_tcbinfo);
1462 * Give the user an updated idea of our state.
1463 * If the generation differs from what we told
1464 * her before, she knows that something happened
1465 * while we were processing this request, and it
1466 * might be necessary to retry.
1468 INP_LIST_RLOCK(&V_tcbinfo);
1469 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1470 xig.xig_sogen = so_gencnt;
1471 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1472 INP_LIST_RUNLOCK(&V_tcbinfo);
1473 error = SYSCTL_OUT(req, &xig, sizeof xig);
1475 free(inp_list, M_TEMP);
1479 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1480 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1481 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1485 tcp_getcred(SYSCTL_HANDLER_ARGS)
1488 struct sockaddr_in addrs[2];
1492 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1495 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1498 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1499 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1501 if (inp->inp_socket == NULL)
1504 error = cr_canseeinpcb(req->td->td_ucred, inp);
1506 cru2x(inp->inp_cred, &xuc);
1511 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1515 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1516 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1517 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1522 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1525 struct sockaddr_in6 addrs[2];
1532 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1535 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1538 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1539 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1542 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1544 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1553 inp = in_pcblookup(&V_tcbinfo,
1554 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1556 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1557 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1560 inp = in6_pcblookup(&V_tcbinfo,
1561 &addrs[1].sin6_addr, addrs[1].sin6_port,
1562 &addrs[0].sin6_addr, addrs[0].sin6_port,
1563 INPLOOKUP_RLOCKPCB, NULL);
1565 if (inp->inp_socket == NULL)
1568 error = cr_canseeinpcb(req->td->td_ucred, inp);
1570 cru2x(inp->inp_cred, &xuc);
1575 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1579 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1580 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1581 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1587 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1589 struct ip *ip = vip;
1591 struct in_addr faddr;
1594 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1596 struct in_conninfo inc;
1597 tcp_seq icmp_tcp_seq;
1600 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1601 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1604 if (cmd == PRC_MSGSIZE)
1605 notify = tcp_mtudisc_notify;
1606 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1607 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1608 notify = tcp_drop_syn_sent;
1610 * Redirects don't need to be handled up here.
1612 else if (PRC_IS_REDIRECT(cmd))
1615 * Source quench is depreciated.
1617 else if (cmd == PRC_QUENCH)
1620 * Hostdead is ugly because it goes linearly through all PCBs.
1621 * XXX: We never get this from ICMP, otherwise it makes an
1622 * excellent DoS attack on machines with many connections.
1624 else if (cmd == PRC_HOSTDEAD)
1626 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1629 icp = (struct icmp *)((caddr_t)ip
1630 - offsetof(struct icmp, icmp_ip));
1631 th = (struct tcphdr *)((caddr_t)ip
1632 + (ip->ip_hl << 2));
1633 INP_INFO_RLOCK(&V_tcbinfo);
1634 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1635 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1637 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1638 !(inp->inp_flags & INP_DROPPED) &&
1639 !(inp->inp_socket == NULL)) {
1640 icmp_tcp_seq = htonl(th->th_seq);
1641 tp = intotcpcb(inp);
1642 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1643 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1644 if (cmd == PRC_MSGSIZE) {
1647 * If we got a needfrag set the MTU
1648 * in the route to the suggested new
1649 * value (if given) and then notify.
1651 bzero(&inc, sizeof(inc));
1652 inc.inc_faddr = faddr;
1654 inp->inp_inc.inc_fibnum;
1656 mtu = ntohs(icp->icmp_nextmtu);
1658 * If no alternative MTU was
1659 * proposed, try the next smaller
1664 ntohs(ip->ip_len), 1);
1665 if (mtu < V_tcp_minmss
1666 + sizeof(struct tcpiphdr))
1668 + sizeof(struct tcpiphdr);
1670 * Only cache the MTU if it
1671 * is smaller than the interface
1672 * or route MTU. tcp_mtudisc()
1673 * will do right thing by itself.
1675 if (mtu <= tcp_maxmtu(&inc, NULL))
1676 tcp_hc_updatemtu(&inc, mtu);
1677 tcp_mtudisc(inp, mtu);
1679 inp = (*notify)(inp,
1680 inetctlerrmap[cmd]);
1686 bzero(&inc, sizeof(inc));
1687 inc.inc_fport = th->th_dport;
1688 inc.inc_lport = th->th_sport;
1689 inc.inc_faddr = faddr;
1690 inc.inc_laddr = ip->ip_src;
1691 syncache_unreach(&inc, th);
1693 INP_INFO_RUNLOCK(&V_tcbinfo);
1695 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1701 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1704 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1705 struct ip6_hdr *ip6;
1707 struct ip6ctlparam *ip6cp = NULL;
1708 const struct sockaddr_in6 *sa6_src = NULL;
1710 struct tcp_portonly {
1715 if (sa->sa_family != AF_INET6 ||
1716 sa->sa_len != sizeof(struct sockaddr_in6))
1719 if (cmd == PRC_MSGSIZE)
1720 notify = tcp_mtudisc_notify;
1721 else if (!PRC_IS_REDIRECT(cmd) &&
1722 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1724 /* Source quench is depreciated. */
1725 else if (cmd == PRC_QUENCH)
1728 /* if the parameter is from icmp6, decode it. */
1730 ip6cp = (struct ip6ctlparam *)d;
1732 ip6 = ip6cp->ip6c_ip6;
1733 off = ip6cp->ip6c_off;
1734 sa6_src = ip6cp->ip6c_src;
1738 off = 0; /* fool gcc */
1743 struct in_conninfo inc;
1745 * XXX: We assume that when IPV6 is non NULL,
1746 * M and OFF are valid.
1749 /* check if we can safely examine src and dst ports */
1750 if (m->m_pkthdr.len < off + sizeof(*thp))
1753 bzero(&th, sizeof(th));
1754 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1756 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1757 (struct sockaddr *)ip6cp->ip6c_src,
1758 th.th_sport, cmd, NULL, notify);
1760 bzero(&inc, sizeof(inc));
1761 inc.inc_fport = th.th_dport;
1762 inc.inc_lport = th.th_sport;
1763 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1764 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1765 inc.inc_flags |= INC_ISIPV6;
1766 INP_INFO_RLOCK(&V_tcbinfo);
1767 syncache_unreach(&inc, &th);
1768 INP_INFO_RUNLOCK(&V_tcbinfo);
1770 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1771 0, cmd, NULL, notify);
1777 * Following is where TCP initial sequence number generation occurs.
1779 * There are two places where we must use initial sequence numbers:
1780 * 1. In SYN-ACK packets.
1781 * 2. In SYN packets.
1783 * All ISNs for SYN-ACK packets are generated by the syncache. See
1784 * tcp_syncache.c for details.
1786 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1787 * depends on this property. In addition, these ISNs should be
1788 * unguessable so as to prevent connection hijacking. To satisfy
1789 * the requirements of this situation, the algorithm outlined in
1790 * RFC 1948 is used, with only small modifications.
1792 * Implementation details:
1794 * Time is based off the system timer, and is corrected so that it
1795 * increases by one megabyte per second. This allows for proper
1796 * recycling on high speed LANs while still leaving over an hour
1799 * As reading the *exact* system time is too expensive to be done
1800 * whenever setting up a TCP connection, we increment the time
1801 * offset in two ways. First, a small random positive increment
1802 * is added to isn_offset for each connection that is set up.
1803 * Second, the function tcp_isn_tick fires once per clock tick
1804 * and increments isn_offset as necessary so that sequence numbers
1805 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1806 * random positive increments serve only to ensure that the same
1807 * exact sequence number is never sent out twice (as could otherwise
1808 * happen when a port is recycled in less than the system tick
1811 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1812 * between seeding of isn_secret. This is normally set to zero,
1813 * as reseeding should not be necessary.
1815 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1816 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1817 * general, this means holding an exclusive (write) lock.
1820 #define ISN_BYTES_PER_SECOND 1048576
1821 #define ISN_STATIC_INCREMENT 4096
1822 #define ISN_RANDOM_INCREMENT (4096 - 1)
1824 static VNET_DEFINE(u_char, isn_secret[32]);
1825 static VNET_DEFINE(int, isn_last);
1826 static VNET_DEFINE(int, isn_last_reseed);
1827 static VNET_DEFINE(u_int32_t, isn_offset);
1828 static VNET_DEFINE(u_int32_t, isn_offset_old);
1830 #define V_isn_secret VNET(isn_secret)
1831 #define V_isn_last VNET(isn_last)
1832 #define V_isn_last_reseed VNET(isn_last_reseed)
1833 #define V_isn_offset VNET(isn_offset)
1834 #define V_isn_offset_old VNET(isn_offset_old)
1837 tcp_new_isn(struct tcpcb *tp)
1840 u_int32_t md5_buffer[4];
1842 u_int32_t projected_offset;
1844 INP_WLOCK_ASSERT(tp->t_inpcb);
1847 /* Seed if this is the first use, reseed if requested. */
1848 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1849 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1851 read_random(&V_isn_secret, sizeof(V_isn_secret));
1852 V_isn_last_reseed = ticks;
1855 /* Compute the md5 hash and return the ISN. */
1857 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1858 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1860 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1861 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1862 sizeof(struct in6_addr));
1863 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1864 sizeof(struct in6_addr));
1868 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1869 sizeof(struct in_addr));
1870 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1871 sizeof(struct in_addr));
1873 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1874 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1875 new_isn = (tcp_seq) md5_buffer[0];
1876 V_isn_offset += ISN_STATIC_INCREMENT +
1877 (arc4random() & ISN_RANDOM_INCREMENT);
1878 if (ticks != V_isn_last) {
1879 projected_offset = V_isn_offset_old +
1880 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1881 if (SEQ_GT(projected_offset, V_isn_offset))
1882 V_isn_offset = projected_offset;
1883 V_isn_offset_old = V_isn_offset;
1886 new_isn += V_isn_offset;
1892 * When a specific ICMP unreachable message is received and the
1893 * connection state is SYN-SENT, drop the connection. This behavior
1894 * is controlled by the icmp_may_rst sysctl.
1897 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1901 INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1902 INP_WLOCK_ASSERT(inp);
1904 if ((inp->inp_flags & INP_TIMEWAIT) ||
1905 (inp->inp_flags & INP_DROPPED))
1908 tp = intotcpcb(inp);
1909 if (tp->t_state != TCPS_SYN_SENT)
1912 tp = tcp_drop(tp, errno);
1920 * When `need fragmentation' ICMP is received, update our idea of the MSS
1921 * based on the new value. Also nudge TCP to send something, since we
1922 * know the packet we just sent was dropped.
1923 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1925 static struct inpcb *
1926 tcp_mtudisc_notify(struct inpcb *inp, int error)
1929 return (tcp_mtudisc(inp, -1));
1933 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1938 INP_WLOCK_ASSERT(inp);
1939 if ((inp->inp_flags & INP_TIMEWAIT) ||
1940 (inp->inp_flags & INP_DROPPED))
1943 tp = intotcpcb(inp);
1944 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1946 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1948 so = inp->inp_socket;
1949 SOCKBUF_LOCK(&so->so_snd);
1950 /* If the mss is larger than the socket buffer, decrease the mss. */
1951 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1952 tp->t_maxseg = so->so_snd.sb_hiwat;
1953 SOCKBUF_UNLOCK(&so->so_snd);
1955 TCPSTAT_INC(tcps_mturesent);
1957 tp->snd_nxt = tp->snd_una;
1958 tcp_free_sackholes(tp);
1959 tp->snd_recover = tp->snd_max;
1960 if (tp->t_flags & TF_SACK_PERMIT)
1961 EXIT_FASTRECOVERY(tp->t_flags);
1968 * Look-up the routing entry to the peer of this inpcb. If no route
1969 * is found and it cannot be allocated, then return 0. This routine
1970 * is called by TCP routines that access the rmx structure and by
1971 * tcp_mss_update to get the peer/interface MTU.
1974 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1977 struct sockaddr_in *dst;
1981 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1983 bzero(&sro, sizeof(sro));
1984 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1985 dst = (struct sockaddr_in *)&sro.ro_dst;
1986 dst->sin_family = AF_INET;
1987 dst->sin_len = sizeof(*dst);
1988 dst->sin_addr = inc->inc_faddr;
1989 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1991 if (sro.ro_rt != NULL) {
1992 ifp = sro.ro_rt->rt_ifp;
1993 if (sro.ro_rt->rt_mtu == 0)
1994 maxmtu = ifp->if_mtu;
1996 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu);
1998 /* Report additional interface capabilities. */
2000 if (ifp->if_capenable & IFCAP_TSO4 &&
2001 ifp->if_hwassist & CSUM_TSO) {
2002 cap->ifcap |= CSUM_TSO;
2003 cap->tsomax = ifp->if_hw_tsomax;
2004 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
2005 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
2016 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
2018 struct route_in6 sro6;
2022 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
2024 bzero(&sro6, sizeof(sro6));
2025 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
2026 sro6.ro_dst.sin6_family = AF_INET6;
2027 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
2028 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
2029 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
2031 if (sro6.ro_rt != NULL) {
2032 ifp = sro6.ro_rt->rt_ifp;
2033 if (sro6.ro_rt->rt_mtu == 0)
2034 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
2036 maxmtu = min(sro6.ro_rt->rt_mtu,
2037 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
2039 /* Report additional interface capabilities. */
2041 if (ifp->if_capenable & IFCAP_TSO6 &&
2042 ifp->if_hwassist & CSUM_TSO) {
2043 cap->ifcap |= CSUM_TSO;
2044 cap->tsomax = ifp->if_hw_tsomax;
2045 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
2046 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
2057 /* compute ESP/AH header size for TCP, including outer IP header. */
2059 ipsec_hdrsiz_tcp(struct tcpcb *tp)
2066 struct ip6_hdr *ip6;
2070 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) ||
2071 (!key_havesp(IPSEC_DIR_OUTBOUND)))
2073 m = m_gethdr(M_NOWAIT, MT_DATA);
2078 if ((inp->inp_vflag & INP_IPV6) != 0) {
2079 ip6 = mtod(m, struct ip6_hdr *);
2080 th = (struct tcphdr *)(ip6 + 1);
2081 m->m_pkthdr.len = m->m_len =
2082 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
2083 tcpip_fillheaders(inp, ip6, th);
2084 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
2088 ip = mtod(m, struct ip *);
2089 th = (struct tcphdr *)(ip + 1);
2090 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
2091 tcpip_fillheaders(inp, ip, th);
2092 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
2100 #ifdef TCP_SIGNATURE
2102 * Callback function invoked by m_apply() to digest TCP segment data
2103 * contained within an mbuf chain.
2106 tcp_signature_apply(void *fstate, void *data, u_int len)
2109 MD5Update(fstate, (u_char *)data, len);
2114 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2117 * m pointer to head of mbuf chain
2119 * len length of TCP segment data, excluding options
2120 * optlen length of TCP segment options
2121 * buf pointer to storage for computed MD5 digest
2122 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2124 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2125 * When called from tcp_input(), we can be sure that th_sum has been
2126 * zeroed out and verified already.
2128 * Return 0 if successful, otherwise return -1.
2130 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2131 * search with the destination IP address, and a 'magic SPI' to be
2132 * determined by the application. This is hardcoded elsewhere to 1179
2133 * right now. Another branch of this code exists which uses the SPD to
2134 * specify per-application flows but it is unstable.
2137 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
2138 u_char *buf, u_int direction)
2140 union sockaddr_union dst;
2142 struct ippseudo ippseudo;
2148 struct ipovly *ipovly;
2150 struct secasvar *sav;
2153 struct ip6_hdr *ip6;
2154 struct in6_addr in6;
2155 char ip6buf[INET6_ADDRSTRLEN];
2161 KASSERT(m != NULL, ("NULL mbuf chain"));
2162 KASSERT(buf != NULL, ("NULL signature pointer"));
2164 /* Extract the destination from the IP header in the mbuf. */
2165 bzero(&dst, sizeof(union sockaddr_union));
2166 ip = mtod(m, struct ip *);
2168 ip6 = NULL; /* Make the compiler happy. */
2173 dst.sa.sa_len = sizeof(struct sockaddr_in);
2174 dst.sa.sa_family = AF_INET;
2175 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
2176 ip->ip_src : ip->ip_dst;
2180 case (IPV6_VERSION >> 4):
2181 ip6 = mtod(m, struct ip6_hdr *);
2182 dst.sa.sa_len = sizeof(struct sockaddr_in6);
2183 dst.sa.sa_family = AF_INET6;
2184 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
2185 ip6->ip6_src : ip6->ip6_dst;
2194 /* Look up an SADB entry which matches the address of the peer. */
2195 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
2197 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
2198 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
2200 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2201 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2209 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2211 * XXX The ippseudo header MUST be digested in network byte order,
2212 * or else we'll fail the regression test. Assume all fields we've
2213 * been doing arithmetic on have been in host byte order.
2214 * XXX One cannot depend on ipovly->ih_len here. When called from
2215 * tcp_output(), the underlying ip_len member has not yet been set.
2220 ipovly = (struct ipovly *)ip;
2221 ippseudo.ippseudo_src = ipovly->ih_src;
2222 ippseudo.ippseudo_dst = ipovly->ih_dst;
2223 ippseudo.ippseudo_pad = 0;
2224 ippseudo.ippseudo_p = IPPROTO_TCP;
2225 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2227 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2229 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2230 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2235 * RFC 2385, 2.0 Proposal
2236 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2237 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2238 * extended next header value (to form 32 bits), and 32-bit segment
2240 * Note: Upper-Layer Packet Length comes before Next Header.
2242 case (IPV6_VERSION >> 4):
2244 in6_clearscope(&in6);
2245 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2247 in6_clearscope(&in6);
2248 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2249 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2250 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2252 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2253 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2254 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2256 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2258 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2259 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2270 * Step 2: Update MD5 hash with TCP header, excluding options.
2271 * The TCP checksum must be set to zero.
2273 savecsum = th->th_sum;
2275 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2276 th->th_sum = savecsum;
2279 * Step 3: Update MD5 hash with TCP segment data.
2280 * Use m_apply() to avoid an early m_pullup().
2283 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2286 * Step 4: Update MD5 hash with shared secret.
2288 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2289 MD5Final(buf, &ctx);
2291 key_sa_recordxfer(sav, m);
2297 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2300 * m pointer to head of mbuf chain
2301 * len length of TCP segment data, excluding options
2302 * optlen length of TCP segment options
2303 * buf pointer to storage for computed MD5 digest
2304 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2306 * Return 1 if successful, otherwise return 0.
2309 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2310 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2312 char tmpdigest[TCP_SIGLEN];
2314 if (tcp_sig_checksigs == 0)
2316 if ((tcpbflag & TF_SIGNATURE) == 0) {
2317 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2320 * If this socket is not expecting signature but
2321 * the segment contains signature just fail.
2323 TCPSTAT_INC(tcps_sig_err_sigopt);
2324 TCPSTAT_INC(tcps_sig_rcvbadsig);
2328 /* Signature is not expected, and not present in segment. */
2333 * If this socket is expecting signature but the segment does not
2334 * contain any just fail.
2336 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2337 TCPSTAT_INC(tcps_sig_err_nosigopt);
2338 TCPSTAT_INC(tcps_sig_rcvbadsig);
2341 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2342 IPSEC_DIR_INBOUND) == -1) {
2343 TCPSTAT_INC(tcps_sig_err_buildsig);
2344 TCPSTAT_INC(tcps_sig_rcvbadsig);
2348 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2349 TCPSTAT_INC(tcps_sig_rcvbadsig);
2352 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2355 #endif /* TCP_SIGNATURE */
2358 sysctl_drop(SYSCTL_HANDLER_ARGS)
2360 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2361 struct sockaddr_storage addrs[2];
2365 struct sockaddr_in *fin, *lin;
2367 struct sockaddr_in6 *fin6, *lin6;
2378 if (req->oldptr != NULL || req->oldlen != 0)
2380 if (req->newptr == NULL)
2382 if (req->newlen < sizeof(addrs))
2384 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2388 switch (addrs[0].ss_family) {
2391 fin6 = (struct sockaddr_in6 *)&addrs[0];
2392 lin6 = (struct sockaddr_in6 *)&addrs[1];
2393 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2394 lin6->sin6_len != sizeof(struct sockaddr_in6))
2396 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2397 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2399 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2400 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2401 fin = (struct sockaddr_in *)&addrs[0];
2402 lin = (struct sockaddr_in *)&addrs[1];
2405 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2408 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2415 fin = (struct sockaddr_in *)&addrs[0];
2416 lin = (struct sockaddr_in *)&addrs[1];
2417 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2418 lin->sin_len != sizeof(struct sockaddr_in))
2425 INP_INFO_RLOCK(&V_tcbinfo);
2426 switch (addrs[0].ss_family) {
2429 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2430 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2431 INPLOOKUP_WLOCKPCB, NULL);
2436 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2437 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2442 if (inp->inp_flags & INP_TIMEWAIT) {
2444 * XXXRW: There currently exists a state where an
2445 * inpcb is present, but its timewait state has been
2446 * discarded. For now, don't allow dropping of this
2454 } else if (!(inp->inp_flags & INP_DROPPED) &&
2455 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2456 tp = intotcpcb(inp);
2457 tp = tcp_drop(tp, ECONNABORTED);
2464 INP_INFO_RUNLOCK(&V_tcbinfo);
2468 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2469 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2470 0, sysctl_drop, "", "Drop TCP connection");
2473 * Generate a standardized TCP log line for use throughout the
2474 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2475 * allow use in the interrupt context.
2477 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2478 * NB: The function may return NULL if memory allocation failed.
2480 * Due to header inclusion and ordering limitations the struct ip
2481 * and ip6_hdr pointers have to be passed as void pointers.
2484 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2488 /* Is logging enabled? */
2489 if (tcp_log_in_vain == 0)
2492 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2496 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2500 /* Is logging enabled? */
2501 if (tcp_log_debug == 0)
2504 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2508 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2515 const struct ip6_hdr *ip6;
2517 ip6 = (const struct ip6_hdr *)ip6hdr;
2519 ip = (struct ip *)ip4hdr;
2522 * The log line looks like this:
2523 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2525 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2526 sizeof(PRINT_TH_FLAGS) + 1 +
2528 2 * INET6_ADDRSTRLEN;
2530 2 * INET_ADDRSTRLEN;
2533 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2537 strcat(s, "TCP: [");
2540 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2541 inet_ntoa_r(inc->inc_faddr, sp);
2543 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2545 inet_ntoa_r(inc->inc_laddr, sp);
2547 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2550 ip6_sprintf(sp, &inc->inc6_faddr);
2552 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2554 ip6_sprintf(sp, &inc->inc6_laddr);
2556 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2557 } else if (ip6 && th) {
2558 ip6_sprintf(sp, &ip6->ip6_src);
2560 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2562 ip6_sprintf(sp, &ip6->ip6_dst);
2564 sprintf(sp, "]:%i", ntohs(th->th_dport));
2567 } else if (ip && th) {
2568 inet_ntoa_r(ip->ip_src, sp);
2570 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2572 inet_ntoa_r(ip->ip_dst, sp);
2574 sprintf(sp, "]:%i", ntohs(th->th_dport));
2582 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2583 if (*(s + size - 1) != '\0')
2584 panic("%s: string too long", __func__);
2589 * A subroutine which makes it easy to track TCP state changes with DTrace.
2590 * This function shouldn't be called for t_state initializations that don't
2591 * correspond to actual TCP state transitions.
2594 tcp_state_change(struct tcpcb *tp, int newstate)
2596 #if defined(KDTRACE_HOOKS)
2597 int pstate = tp->t_state;
2600 tp->t_state = newstate;
2601 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);