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_pcap.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_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
145 CTLFLAG_VNET | 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_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
167 CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW,
182 &VNET_NAME(tcp_minmss), 0,
183 "Minimum TCP Maximum Segment Size");
185 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
186 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | 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;
195 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
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_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW,
214 &VNET_NAME(tcp_isn_reseed_interval), 0,
215 "Seconds between reseeding of ISN secret");
217 static int tcp_soreceive_stream;
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 void tcp_mtudisc(struct inpcb *, int);
235 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
236 void *ip4hdr, const void *ip6hdr);
237 static void tcp_timer_discard(struct tcpcb *, uint32_t);
240 * Target size of TCP PCB hash tables. Must be a power of two.
242 * Note that this can be overridden by the kernel environment
243 * variable net.inet.tcp.tcbhashsize
246 #define TCBHASHSIZE 0
251 * Callouts should be moved into struct tcp directly. They are currently
252 * separate because the tcpcb structure is exported to userland for sysctl
253 * parsing purposes, which do not know about callouts.
262 static VNET_DEFINE(uma_zone_t, tcpcb_zone);
263 #define V_tcpcb_zone VNET(tcpcb_zone)
265 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
266 static struct mtx isn_mtx;
268 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
269 #define ISN_LOCK() mtx_lock(&isn_mtx)
270 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
273 * TCP initialization.
276 tcp_zone_change(void *tag)
279 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
280 uma_zone_set_max(V_tcpcb_zone, maxsockets);
281 tcp_tw_zone_change();
285 tcp_inpcb_init(void *mem, int size, int flags)
287 struct inpcb *inp = mem;
289 INP_LOCK_INIT(inp, "inp", "tcpinp");
294 * Take a value and get the next power of 2 that doesn't overflow.
295 * Used to size the tcp_inpcb hash buckets.
298 maketcp_hashsize(int size)
304 * get the next power of 2 higher than maxsockets.
306 hashsize = 1 << fls(size);
307 /* catch overflow, and just go one power of 2 smaller */
308 if (hashsize < size) {
309 hashsize = 1 << (fls(size) - 1);
317 const char *tcbhash_tuneable;
320 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
322 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
323 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
324 printf("%s: WARNING: unable to register helper hook\n", __func__);
325 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
326 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
327 printf("%s: WARNING: unable to register helper hook\n", __func__);
329 hashsize = TCBHASHSIZE;
330 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
333 * Auto tune the hash size based on maxsockets.
334 * A perfect hash would have a 1:1 mapping
335 * (hashsize = maxsockets) however it's been
336 * suggested that O(2) average is better.
338 hashsize = maketcp_hashsize(maxsockets / 4);
340 * Our historical default is 512,
341 * do not autotune lower than this.
346 printf("%s: %s auto tuned to %d\n", __func__,
347 tcbhash_tuneable, hashsize);
350 * We require a hashsize to be a power of two.
351 * Previously if it was not a power of two we would just reset it
352 * back to 512, which could be a nasty surprise if you did not notice
354 * Instead what we do is clip it to the closest power of two lower
355 * than the specified hash value.
357 if (!powerof2(hashsize)) {
358 int oldhashsize = hashsize;
360 hashsize = maketcp_hashsize(hashsize);
361 /* prevent absurdly low value */
364 printf("%s: WARNING: TCB hash size not a power of 2, "
365 "clipped from %d to %d.\n", __func__, oldhashsize,
368 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
369 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
370 IPI_HASHFIELDS_4TUPLE);
373 * These have to be type stable for the benefit of the timers.
375 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
376 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
377 uma_zone_set_max(V_tcpcb_zone, maxsockets);
378 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
384 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
385 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
386 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
388 /* Skip initialization of globals for non-default instances. */
389 if (!IS_DEFAULT_VNET(curvnet))
392 tcp_reass_global_init();
394 /* XXX virtualize those bellow? */
395 tcp_delacktime = TCPTV_DELACK;
396 tcp_keepinit = TCPTV_KEEP_INIT;
397 tcp_keepidle = TCPTV_KEEP_IDLE;
398 tcp_keepintvl = TCPTV_KEEPINTVL;
399 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
401 tcp_rexmit_min = TCPTV_MIN;
402 if (tcp_rexmit_min < 1)
404 tcp_rexmit_slop = TCPTV_CPU_VAR;
405 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
406 tcp_tcbhashsize = hashsize;
408 if (tcp_soreceive_stream) {
410 tcp_usrreqs.pru_soreceive = soreceive_stream;
413 tcp6_usrreqs.pru_soreceive = soreceive_stream;
418 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
420 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
422 if (max_protohdr < TCP_MINPROTOHDR)
423 max_protohdr = TCP_MINPROTOHDR;
424 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
426 #undef TCP_MINPROTOHDR
429 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
430 SHUTDOWN_PRI_DEFAULT);
431 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
432 EVENTHANDLER_PRI_ANY);
447 in_pcbinfo_destroy(&V_tcbinfo);
448 uma_zdestroy(V_sack_hole_zone);
449 uma_zdestroy(V_tcpcb_zone);
451 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
453 printf("%s: WARNING: unable to deregister helper hook "
454 "type=%d, id=%d: error %d returned\n", __func__,
455 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
457 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
459 printf("%s: WARNING: unable to deregister helper hook "
460 "type=%d, id=%d: error %d returned\n", __func__,
461 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
473 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
474 * tcp_template used to store this data in mbufs, but we now recopy it out
475 * of the tcpcb each time to conserve mbufs.
478 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
480 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
482 INP_WLOCK_ASSERT(inp);
485 if ((inp->inp_vflag & INP_IPV6) != 0) {
488 ip6 = (struct ip6_hdr *)ip_ptr;
489 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
490 (inp->inp_flow & IPV6_FLOWINFO_MASK);
491 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
492 (IPV6_VERSION & IPV6_VERSION_MASK);
493 ip6->ip6_nxt = IPPROTO_TCP;
494 ip6->ip6_plen = htons(sizeof(struct tcphdr));
495 ip6->ip6_src = inp->in6p_laddr;
496 ip6->ip6_dst = inp->in6p_faddr;
499 #if defined(INET6) && defined(INET)
506 ip = (struct ip *)ip_ptr;
507 ip->ip_v = IPVERSION;
509 ip->ip_tos = inp->inp_ip_tos;
513 ip->ip_ttl = inp->inp_ip_ttl;
515 ip->ip_p = IPPROTO_TCP;
516 ip->ip_src = inp->inp_laddr;
517 ip->ip_dst = inp->inp_faddr;
520 th->th_sport = inp->inp_lport;
521 th->th_dport = inp->inp_fport;
529 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
533 * Create template to be used to send tcp packets on a connection.
534 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
535 * use for this function is in keepalives, which use tcp_respond.
538 tcpip_maketemplate(struct inpcb *inp)
542 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
545 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
550 * Send a single message to the TCP at address specified by
551 * the given TCP/IP header. If m == NULL, then we make a copy
552 * of the tcpiphdr at th and send directly to the addressed host.
553 * This is used to force keep alive messages out using the TCP
554 * template for a connection. If flags are given then we send
555 * a message back to the TCP which originated the segment th,
556 * and discard the mbuf containing it and any other attached mbufs.
558 * In any case the ack and sequence number of the transmitted
559 * segment are as specified by the parameters.
561 * NOTE: If m != NULL, then th must point to *inside* the mbuf.
564 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
565 tcp_seq ack, tcp_seq seq, int flags)
578 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
581 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
588 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
589 INP_WLOCK_ASSERT(inp);
594 if (!(flags & TH_RST)) {
595 win = sbspace(&inp->inp_socket->so_rcv);
596 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
597 win = (long)TCP_MAXWIN << tp->rcv_scale;
601 m = m_gethdr(M_NOWAIT, MT_DATA);
605 m->m_data += max_linkhdr;
608 bcopy((caddr_t)ip6, mtod(m, caddr_t),
609 sizeof(struct ip6_hdr));
610 ip6 = mtod(m, struct ip6_hdr *);
611 nth = (struct tcphdr *)(ip6 + 1);
615 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
616 ip = mtod(m, struct ip *);
617 nth = (struct tcphdr *)(ip + 1);
619 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
624 * XXX MRT We inherrit the FIB, which is lucky.
628 m->m_data = (caddr_t)ipgen;
629 /* m_len is set later */
631 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
634 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
635 nth = (struct tcphdr *)(ip6 + 1);
639 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
640 nth = (struct tcphdr *)(ip + 1);
644 * this is usually a case when an extension header
645 * exists between the IPv6 header and the
648 nth->th_sport = th->th_sport;
649 nth->th_dport = th->th_dport;
651 xchg(nth->th_dport, nth->th_sport, uint16_t);
657 ip6->ip6_vfc = IPV6_VERSION;
658 ip6->ip6_nxt = IPPROTO_TCP;
659 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
660 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
663 #if defined(INET) && defined(INET6)
668 tlen += sizeof (struct tcpiphdr);
669 ip->ip_len = htons(tlen);
670 ip->ip_ttl = V_ip_defttl;
671 if (V_path_mtu_discovery)
672 ip->ip_off |= htons(IP_DF);
676 m->m_pkthdr.len = tlen;
677 m->m_pkthdr.rcvif = NULL;
681 * Packet is associated with a socket, so allow the
682 * label of the response to reflect the socket label.
684 INP_WLOCK_ASSERT(inp);
685 mac_inpcb_create_mbuf(inp, m);
688 * Packet is not associated with a socket, so possibly
689 * update the label in place.
691 mac_netinet_tcp_reply(m);
694 nth->th_seq = htonl(seq);
695 nth->th_ack = htonl(ack);
697 nth->th_off = sizeof (struct tcphdr) >> 2;
698 nth->th_flags = flags;
700 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
702 nth->th_win = htons((u_short)win);
705 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
708 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
709 nth->th_sum = in6_cksum_pseudo(ip6,
710 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
711 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
715 #if defined(INET6) && defined(INET)
720 m->m_pkthdr.csum_flags = CSUM_TCP;
721 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
722 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
726 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
727 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
729 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
731 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *),
734 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth);
737 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
739 #if defined(INET) && defined(INET6)
743 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
748 * Create a new TCP control block, making an
749 * empty reassembly queue and hooking it to the argument
750 * protocol control block. The `inp' parameter must have
751 * come from the zone allocator set up in tcp_init().
754 tcp_newtcpcb(struct inpcb *inp)
756 struct tcpcb_mem *tm;
759 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
762 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
767 /* Initialise cc_var struct for this tcpcb. */
769 tp->ccv->type = IPPROTO_TCP;
770 tp->ccv->ccvc.tcp = tp;
773 * Use the current system default CC algorithm.
776 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
777 CC_ALGO(tp) = CC_DEFAULT();
780 if (CC_ALGO(tp)->cb_init != NULL)
781 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
782 uma_zfree(V_tcpcb_zone, tm);
787 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
788 uma_zfree(V_tcpcb_zone, tm);
793 tp->t_vnet = inp->inp_vnet;
795 tp->t_timers = &tm->tt;
796 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
797 tp->t_maxseg = tp->t_maxopd =
799 isipv6 ? V_tcp_v6mssdflt :
803 /* Set up our timeouts. */
804 callout_init(&tp->t_timers->tt_rexmt, 1);
805 callout_init(&tp->t_timers->tt_persist, 1);
806 callout_init(&tp->t_timers->tt_keep, 1);
807 callout_init(&tp->t_timers->tt_2msl, 1);
808 callout_init(&tp->t_timers->tt_delack, 1);
810 if (V_tcp_do_rfc1323)
811 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
813 tp->t_flags |= TF_SACK_PERMIT;
814 TAILQ_INIT(&tp->snd_holes);
816 * The tcpcb will hold a reference on its inpcb until tcp_discardcb()
819 in_pcbref(inp); /* Reference for tcpcb */
823 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
824 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
825 * reasonable initial retransmit time.
827 tp->t_srtt = TCPTV_SRTTBASE;
828 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
829 tp->t_rttmin = tcp_rexmit_min;
830 tp->t_rxtcur = TCPTV_RTOBASE;
831 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
832 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
833 tp->t_rcvtime = ticks;
835 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
836 * because the socket may be bound to an IPv6 wildcard address,
837 * which may match an IPv4-mapped IPv6 address.
839 inp->inp_ip_ttl = V_ip_defttl;
843 * Init the TCP PCAP queues.
845 tcp_pcap_tcpcb_init(tp);
847 return (tp); /* XXX */
851 * Switch the congestion control algorithm back to NewReno for any active
852 * control blocks using an algorithm which is about to go away.
853 * This ensures the CC framework can allow the unload to proceed without leaving
854 * any dangling pointers which would trigger a panic.
855 * Returning non-zero would inform the CC framework that something went wrong
856 * and it would be unsafe to allow the unload to proceed. However, there is no
857 * way for this to occur with this implementation so we always return zero.
860 tcp_ccalgounload(struct cc_algo *unload_algo)
862 struct cc_algo *tmpalgo;
865 VNET_ITERATOR_DECL(vnet_iter);
868 * Check all active control blocks across all network stacks and change
869 * any that are using "unload_algo" back to NewReno. If "unload_algo"
870 * requires cleanup code to be run, call it.
873 VNET_FOREACH(vnet_iter) {
874 CURVNET_SET(vnet_iter);
875 INP_INFO_WLOCK(&V_tcbinfo);
877 * New connections already part way through being initialised
878 * with the CC algo we're removing will not race with this code
879 * because the INP_INFO_WLOCK is held during initialisation. We
880 * therefore don't enter the loop below until the connection
881 * list has stabilised.
883 LIST_FOREACH(inp, &V_tcb, inp_list) {
885 /* Important to skip tcptw structs. */
886 if (!(inp->inp_flags & INP_TIMEWAIT) &&
887 (tp = intotcpcb(inp)) != NULL) {
889 * By holding INP_WLOCK here, we are assured
890 * that the connection is not currently
891 * executing inside the CC module's functions
892 * i.e. it is safe to make the switch back to
895 if (CC_ALGO(tp) == unload_algo) {
896 tmpalgo = CC_ALGO(tp);
897 /* NewReno does not require any init. */
898 CC_ALGO(tp) = &newreno_cc_algo;
899 if (tmpalgo->cb_destroy != NULL)
900 tmpalgo->cb_destroy(tp->ccv);
905 INP_INFO_WUNLOCK(&V_tcbinfo);
914 * Drop a TCP connection, reporting
915 * the specified error. If connection is synchronized,
916 * then send a RST to peer.
919 tcp_drop(struct tcpcb *tp, int errno)
921 struct socket *so = tp->t_inpcb->inp_socket;
923 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
924 INP_WLOCK_ASSERT(tp->t_inpcb);
926 if (TCPS_HAVERCVDSYN(tp->t_state)) {
927 tcp_state_change(tp, TCPS_CLOSED);
928 (void) tcp_output(tp);
929 TCPSTAT_INC(tcps_drops);
931 TCPSTAT_INC(tcps_conndrops);
932 if (errno == ETIMEDOUT && tp->t_softerror)
933 errno = tp->t_softerror;
934 so->so_error = errno;
935 return (tcp_close(tp));
939 tcp_discardcb(struct tcpcb *tp)
941 struct inpcb *inp = tp->t_inpcb;
942 struct socket *so = inp->inp_socket;
944 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
948 INP_WLOCK_ASSERT(inp);
951 * Make sure that all of our timers are stopped before we delete the
954 * If stopping a timer fails, we schedule a discard function in same
955 * callout, and the last discard function called will take care of
956 * deleting the tcpcb.
958 tcp_timer_stop(tp, TT_REXMT);
959 tcp_timer_stop(tp, TT_PERSIST);
960 tcp_timer_stop(tp, TT_KEEP);
961 tcp_timer_stop(tp, TT_2MSL);
962 tcp_timer_stop(tp, TT_DELACK);
965 * If we got enough samples through the srtt filter,
966 * save the rtt and rttvar in the routing entry.
967 * 'Enough' is arbitrarily defined as 4 rtt samples.
968 * 4 samples is enough for the srtt filter to converge
969 * to within enough % of the correct value; fewer samples
970 * and we could save a bogus rtt. The danger is not high
971 * as tcp quickly recovers from everything.
972 * XXX: Works very well but needs some more statistics!
974 if (tp->t_rttupdated >= 4) {
975 struct hc_metrics_lite metrics;
978 bzero(&metrics, sizeof(metrics));
980 * Update the ssthresh always when the conditions below
981 * are satisfied. This gives us better new start value
982 * for the congestion avoidance for new connections.
983 * ssthresh is only set if packet loss occured on a session.
985 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
986 * being torn down. Ideally this code would not use 'so'.
988 ssthresh = tp->snd_ssthresh;
989 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
991 * convert the limit from user data bytes to
992 * packets then to packet data bytes.
994 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
997 ssthresh *= (u_long)(tp->t_maxseg +
999 (isipv6 ? sizeof (struct ip6_hdr) +
1000 sizeof (struct tcphdr) :
1002 sizeof (struct tcpiphdr)
1009 metrics.rmx_ssthresh = ssthresh;
1011 metrics.rmx_rtt = tp->t_srtt;
1012 metrics.rmx_rttvar = tp->t_rttvar;
1013 metrics.rmx_cwnd = tp->snd_cwnd;
1014 metrics.rmx_sendpipe = 0;
1015 metrics.rmx_recvpipe = 0;
1017 tcp_hc_update(&inp->inp_inc, &metrics);
1020 /* free the reassembly queue, if any */
1021 tcp_reass_flush(tp);
1024 /* Disconnect offload device, if any. */
1025 if (tp->t_flags & TF_TOE)
1026 tcp_offload_detach(tp);
1029 tcp_free_sackholes(tp);
1032 /* Free the TCP PCAP queues. */
1033 tcp_pcap_drain(&(tp->t_inpkts));
1034 tcp_pcap_drain(&(tp->t_outpkts));
1037 /* Allow the CC algorithm to clean up after itself. */
1038 if (CC_ALGO(tp)->cb_destroy != NULL)
1039 CC_ALGO(tp)->cb_destroy(tp->ccv);
1041 khelp_destroy_osd(tp->osd);
1044 inp->inp_ppcb = NULL;
1045 if ((tp->t_timers->tt_flags & TT_MASK) == 0) {
1046 /* We own the last reference on tcpcb, let's free it. */
1048 uma_zfree(V_tcpcb_zone, tp);
1049 released = in_pcbrele_wlocked(inp);
1050 KASSERT(!released, ("%s: inp %p should not have been released "
1051 "here", __func__, inp));
1056 tcp_timer_2msl_discard(void *xtp)
1059 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL);
1063 tcp_timer_keep_discard(void *xtp)
1066 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP);
1070 tcp_timer_persist_discard(void *xtp)
1073 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST);
1077 tcp_timer_rexmt_discard(void *xtp)
1080 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT);
1084 tcp_timer_delack_discard(void *xtp)
1087 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK);
1091 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type)
1095 CURVNET_SET(tp->t_vnet);
1096 INP_INFO_RLOCK(&V_tcbinfo);
1098 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL",
1101 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0,
1102 ("%s: tcpcb has to be stopped here", __func__));
1103 KASSERT((tp->t_timers->tt_flags & timer_type) != 0,
1104 ("%s: discard callout should be running", __func__));
1105 tp->t_timers->tt_flags &= ~timer_type;
1106 if ((tp->t_timers->tt_flags & TT_MASK) == 0) {
1107 /* We own the last reference on this tcpcb, let's free it. */
1109 uma_zfree(V_tcpcb_zone, tp);
1110 if (in_pcbrele_wlocked(inp)) {
1111 INP_INFO_RUNLOCK(&V_tcbinfo);
1117 INP_INFO_RUNLOCK(&V_tcbinfo);
1122 * Attempt to close a TCP control block, marking it as dropped, and freeing
1123 * the socket if we hold the only reference.
1126 tcp_close(struct tcpcb *tp)
1128 struct inpcb *inp = tp->t_inpcb;
1131 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1132 INP_WLOCK_ASSERT(inp);
1135 if (tp->t_state == TCPS_LISTEN)
1136 tcp_offload_listen_stop(tp);
1139 TCPSTAT_INC(tcps_closed);
1140 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1141 so = inp->inp_socket;
1142 soisdisconnected(so);
1143 if (inp->inp_flags & INP_SOCKREF) {
1144 KASSERT(so->so_state & SS_PROTOREF,
1145 ("tcp_close: !SS_PROTOREF"));
1146 inp->inp_flags &= ~INP_SOCKREF;
1150 so->so_state &= ~SS_PROTOREF;
1160 VNET_ITERATOR_DECL(vnet_iter);
1165 VNET_LIST_RLOCK_NOSLEEP();
1166 VNET_FOREACH(vnet_iter) {
1167 CURVNET_SET(vnet_iter);
1172 * Walk the tcpbs, if existing, and flush the reassembly queue,
1173 * if there is one...
1174 * XXX: The "Net/3" implementation doesn't imply that the TCP
1175 * reassembly queue should be flushed, but in a situation
1176 * where we're really low on mbufs, this is potentially
1179 INP_INFO_WLOCK(&V_tcbinfo);
1180 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1181 if (inpb->inp_flags & INP_TIMEWAIT)
1184 if ((tcpb = intotcpcb(inpb)) != NULL) {
1185 tcp_reass_flush(tcpb);
1186 tcp_clean_sackreport(tcpb);
1190 INP_INFO_WUNLOCK(&V_tcbinfo);
1193 VNET_LIST_RUNLOCK_NOSLEEP();
1197 * Notify a tcp user of an asynchronous error;
1198 * store error as soft error, but wake up user
1199 * (for now, won't do anything until can select for soft error).
1201 * Do not wake up user since there currently is no mechanism for
1202 * reporting soft errors (yet - a kqueue filter may be added).
1204 static struct inpcb *
1205 tcp_notify(struct inpcb *inp, int error)
1209 INP_INFO_LOCK_ASSERT(&V_tcbinfo);
1210 INP_WLOCK_ASSERT(inp);
1212 if ((inp->inp_flags & INP_TIMEWAIT) ||
1213 (inp->inp_flags & INP_DROPPED))
1216 tp = intotcpcb(inp);
1217 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1220 * Ignore some errors if we are hooked up.
1221 * If connection hasn't completed, has retransmitted several times,
1222 * and receives a second error, give up now. This is better
1223 * than waiting a long time to establish a connection that
1224 * can never complete.
1226 if (tp->t_state == TCPS_ESTABLISHED &&
1227 (error == EHOSTUNREACH || error == ENETUNREACH ||
1228 error == EHOSTDOWN)) {
1230 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1232 tp = tcp_drop(tp, error);
1238 tp->t_softerror = error;
1242 wakeup( &so->so_timeo);
1249 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1251 int error, i, m, n, pcb_count;
1252 struct inpcb *inp, **inp_list;
1257 * The process of preparing the TCB list is too time-consuming and
1258 * resource-intensive to repeat twice on every request.
1260 if (req->oldptr == NULL) {
1261 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1262 n += imax(n / 8, 10);
1263 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1267 if (req->newptr != NULL)
1271 * OK, now we're committed to doing something.
1273 INP_LIST_RLOCK(&V_tcbinfo);
1274 gencnt = V_tcbinfo.ipi_gencnt;
1275 n = V_tcbinfo.ipi_count;
1276 INP_LIST_RUNLOCK(&V_tcbinfo);
1278 m = syncache_pcbcount();
1280 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1281 + (n + m) * sizeof(struct xtcpcb));
1285 xig.xig_len = sizeof xig;
1286 xig.xig_count = n + m;
1287 xig.xig_gen = gencnt;
1288 xig.xig_sogen = so_gencnt;
1289 error = SYSCTL_OUT(req, &xig, sizeof xig);
1293 error = syncache_pcblist(req, m, &pcb_count);
1297 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1298 if (inp_list == NULL)
1301 INP_INFO_WLOCK(&V_tcbinfo);
1302 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1303 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1305 if (inp->inp_gencnt <= gencnt) {
1307 * XXX: This use of cr_cansee(), introduced with
1308 * TCP state changes, is not quite right, but for
1309 * now, better than nothing.
1311 if (inp->inp_flags & INP_TIMEWAIT) {
1312 if (intotw(inp) != NULL)
1313 error = cr_cansee(req->td->td_ucred,
1314 intotw(inp)->tw_cred);
1316 error = EINVAL; /* Skip this inp. */
1318 error = cr_canseeinpcb(req->td->td_ucred, inp);
1321 inp_list[i++] = inp;
1326 INP_INFO_WUNLOCK(&V_tcbinfo);
1330 for (i = 0; i < n; i++) {
1333 if (inp->inp_gencnt <= gencnt) {
1337 bzero(&xt, sizeof(xt));
1338 xt.xt_len = sizeof xt;
1339 /* XXX should avoid extra copy */
1340 bcopy(inp, &xt.xt_inp, sizeof *inp);
1341 inp_ppcb = inp->inp_ppcb;
1342 if (inp_ppcb == NULL)
1343 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1344 else if (inp->inp_flags & INP_TIMEWAIT) {
1345 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1346 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1348 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1349 if (xt.xt_tp.t_timers)
1350 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1352 if (inp->inp_socket != NULL)
1353 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1355 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1356 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1358 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1360 error = SYSCTL_OUT(req, &xt, sizeof xt);
1364 INP_INFO_RLOCK(&V_tcbinfo);
1365 for (i = 0; i < n; i++) {
1368 if (!in_pcbrele_rlocked(inp))
1371 INP_INFO_RUNLOCK(&V_tcbinfo);
1375 * Give the user an updated idea of our state.
1376 * If the generation differs from what we told
1377 * her before, she knows that something happened
1378 * while we were processing this request, and it
1379 * might be necessary to retry.
1381 INP_LIST_RLOCK(&V_tcbinfo);
1382 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1383 xig.xig_sogen = so_gencnt;
1384 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1385 INP_LIST_RUNLOCK(&V_tcbinfo);
1386 error = SYSCTL_OUT(req, &xig, sizeof xig);
1388 free(inp_list, M_TEMP);
1392 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1393 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1394 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1398 tcp_getcred(SYSCTL_HANDLER_ARGS)
1401 struct sockaddr_in addrs[2];
1405 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1408 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1411 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1412 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1414 if (inp->inp_socket == NULL)
1417 error = cr_canseeinpcb(req->td->td_ucred, inp);
1419 cru2x(inp->inp_cred, &xuc);
1424 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1428 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1429 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1430 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1435 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1438 struct sockaddr_in6 addrs[2];
1445 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1448 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1451 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1452 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1455 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1457 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1466 inp = in_pcblookup(&V_tcbinfo,
1467 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1469 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1470 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1473 inp = in6_pcblookup(&V_tcbinfo,
1474 &addrs[1].sin6_addr, addrs[1].sin6_port,
1475 &addrs[0].sin6_addr, addrs[0].sin6_port,
1476 INPLOOKUP_RLOCKPCB, NULL);
1478 if (inp->inp_socket == NULL)
1481 error = cr_canseeinpcb(req->td->td_ucred, inp);
1483 cru2x(inp->inp_cred, &xuc);
1488 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1492 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1493 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1494 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1500 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1502 struct ip *ip = vip;
1504 struct in_addr faddr;
1507 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1509 struct in_conninfo inc;
1510 tcp_seq icmp_tcp_seq;
1513 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1514 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1517 if (cmd == PRC_MSGSIZE)
1518 notify = tcp_mtudisc_notify;
1519 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1520 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1521 notify = tcp_drop_syn_sent;
1523 * Redirects don't need to be handled up here.
1525 else if (PRC_IS_REDIRECT(cmd))
1528 * Hostdead is ugly because it goes linearly through all PCBs.
1529 * XXX: We never get this from ICMP, otherwise it makes an
1530 * excellent DoS attack on machines with many connections.
1532 else if (cmd == PRC_HOSTDEAD)
1534 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1538 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1542 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1543 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2));
1544 INP_INFO_RLOCK(&V_tcbinfo);
1545 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src,
1546 th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1548 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1549 !(inp->inp_flags & INP_DROPPED) &&
1550 !(inp->inp_socket == NULL)) {
1551 icmp_tcp_seq = ntohl(th->th_seq);
1552 tp = intotcpcb(inp);
1553 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1554 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1555 if (cmd == PRC_MSGSIZE) {
1558 * If we got a needfrag set the MTU
1559 * in the route to the suggested new
1560 * value (if given) and then notify.
1562 mtu = ntohs(icp->icmp_nextmtu);
1564 * If no alternative MTU was
1565 * proposed, try the next smaller
1570 ntohs(ip->ip_len), 1);
1571 if (mtu < V_tcp_minmss +
1572 sizeof(struct tcpiphdr))
1573 mtu = V_tcp_minmss +
1574 sizeof(struct tcpiphdr);
1576 * Only process the offered MTU if it
1577 * is smaller than the current one.
1579 if (mtu < tp->t_maxopd +
1580 sizeof(struct tcpiphdr)) {
1581 bzero(&inc, sizeof(inc));
1582 inc.inc_faddr = faddr;
1584 inp->inp_inc.inc_fibnum;
1585 tcp_hc_updatemtu(&inc, mtu);
1586 tcp_mtudisc(inp, mtu);
1589 inp = (*notify)(inp,
1590 inetctlerrmap[cmd]);
1596 bzero(&inc, sizeof(inc));
1597 inc.inc_fport = th->th_dport;
1598 inc.inc_lport = th->th_sport;
1599 inc.inc_faddr = faddr;
1600 inc.inc_laddr = ip->ip_src;
1601 syncache_unreach(&inc, th);
1603 INP_INFO_RUNLOCK(&V_tcbinfo);
1609 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1612 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1613 struct ip6_hdr *ip6;
1615 struct ip6ctlparam *ip6cp = NULL;
1616 const struct sockaddr_in6 *sa6_src = NULL;
1618 struct tcp_portonly {
1623 if (sa->sa_family != AF_INET6 ||
1624 sa->sa_len != sizeof(struct sockaddr_in6))
1627 if (cmd == PRC_MSGSIZE)
1628 notify = tcp_mtudisc_notify;
1629 else if (!PRC_IS_REDIRECT(cmd) &&
1630 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1633 /* if the parameter is from icmp6, decode it. */
1635 ip6cp = (struct ip6ctlparam *)d;
1637 ip6 = ip6cp->ip6c_ip6;
1638 off = ip6cp->ip6c_off;
1639 sa6_src = ip6cp->ip6c_src;
1643 off = 0; /* fool gcc */
1648 struct in_conninfo inc;
1650 * XXX: We assume that when IPV6 is non NULL,
1651 * M and OFF are valid.
1654 /* check if we can safely examine src and dst ports */
1655 if (m->m_pkthdr.len < off + sizeof(*thp))
1658 bzero(&th, sizeof(th));
1659 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1661 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1662 (struct sockaddr *)ip6cp->ip6c_src,
1663 th.th_sport, cmd, NULL, notify);
1665 bzero(&inc, sizeof(inc));
1666 inc.inc_fport = th.th_dport;
1667 inc.inc_lport = th.th_sport;
1668 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1669 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1670 inc.inc_flags |= INC_ISIPV6;
1671 INP_INFO_RLOCK(&V_tcbinfo);
1672 syncache_unreach(&inc, &th);
1673 INP_INFO_RUNLOCK(&V_tcbinfo);
1675 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1676 0, cmd, NULL, notify);
1682 * Following is where TCP initial sequence number generation occurs.
1684 * There are two places where we must use initial sequence numbers:
1685 * 1. In SYN-ACK packets.
1686 * 2. In SYN packets.
1688 * All ISNs for SYN-ACK packets are generated by the syncache. See
1689 * tcp_syncache.c for details.
1691 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1692 * depends on this property. In addition, these ISNs should be
1693 * unguessable so as to prevent connection hijacking. To satisfy
1694 * the requirements of this situation, the algorithm outlined in
1695 * RFC 1948 is used, with only small modifications.
1697 * Implementation details:
1699 * Time is based off the system timer, and is corrected so that it
1700 * increases by one megabyte per second. This allows for proper
1701 * recycling on high speed LANs while still leaving over an hour
1704 * As reading the *exact* system time is too expensive to be done
1705 * whenever setting up a TCP connection, we increment the time
1706 * offset in two ways. First, a small random positive increment
1707 * is added to isn_offset for each connection that is set up.
1708 * Second, the function tcp_isn_tick fires once per clock tick
1709 * and increments isn_offset as necessary so that sequence numbers
1710 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1711 * random positive increments serve only to ensure that the same
1712 * exact sequence number is never sent out twice (as could otherwise
1713 * happen when a port is recycled in less than the system tick
1716 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1717 * between seeding of isn_secret. This is normally set to zero,
1718 * as reseeding should not be necessary.
1720 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1721 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1722 * general, this means holding an exclusive (write) lock.
1725 #define ISN_BYTES_PER_SECOND 1048576
1726 #define ISN_STATIC_INCREMENT 4096
1727 #define ISN_RANDOM_INCREMENT (4096 - 1)
1729 static VNET_DEFINE(u_char, isn_secret[32]);
1730 static VNET_DEFINE(int, isn_last);
1731 static VNET_DEFINE(int, isn_last_reseed);
1732 static VNET_DEFINE(u_int32_t, isn_offset);
1733 static VNET_DEFINE(u_int32_t, isn_offset_old);
1735 #define V_isn_secret VNET(isn_secret)
1736 #define V_isn_last VNET(isn_last)
1737 #define V_isn_last_reseed VNET(isn_last_reseed)
1738 #define V_isn_offset VNET(isn_offset)
1739 #define V_isn_offset_old VNET(isn_offset_old)
1742 tcp_new_isn(struct tcpcb *tp)
1745 u_int32_t md5_buffer[4];
1747 u_int32_t projected_offset;
1749 INP_WLOCK_ASSERT(tp->t_inpcb);
1752 /* Seed if this is the first use, reseed if requested. */
1753 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1754 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1756 read_random(&V_isn_secret, sizeof(V_isn_secret));
1757 V_isn_last_reseed = ticks;
1760 /* Compute the md5 hash and return the ISN. */
1762 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1763 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1765 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1766 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1767 sizeof(struct in6_addr));
1768 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1769 sizeof(struct in6_addr));
1773 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1774 sizeof(struct in_addr));
1775 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1776 sizeof(struct in_addr));
1778 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1779 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1780 new_isn = (tcp_seq) md5_buffer[0];
1781 V_isn_offset += ISN_STATIC_INCREMENT +
1782 (arc4random() & ISN_RANDOM_INCREMENT);
1783 if (ticks != V_isn_last) {
1784 projected_offset = V_isn_offset_old +
1785 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1786 if (SEQ_GT(projected_offset, V_isn_offset))
1787 V_isn_offset = projected_offset;
1788 V_isn_offset_old = V_isn_offset;
1791 new_isn += V_isn_offset;
1797 * When a specific ICMP unreachable message is received and the
1798 * connection state is SYN-SENT, drop the connection. This behavior
1799 * is controlled by the icmp_may_rst sysctl.
1802 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1806 INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1807 INP_WLOCK_ASSERT(inp);
1809 if ((inp->inp_flags & INP_TIMEWAIT) ||
1810 (inp->inp_flags & INP_DROPPED))
1813 tp = intotcpcb(inp);
1814 if (tp->t_state != TCPS_SYN_SENT)
1817 tp = tcp_drop(tp, errno);
1825 * When `need fragmentation' ICMP is received, update our idea of the MSS
1826 * based on the new value. Also nudge TCP to send something, since we
1827 * know the packet we just sent was dropped.
1828 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1830 static struct inpcb *
1831 tcp_mtudisc_notify(struct inpcb *inp, int error)
1834 tcp_mtudisc(inp, -1);
1839 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1844 INP_WLOCK_ASSERT(inp);
1845 if ((inp->inp_flags & INP_TIMEWAIT) ||
1846 (inp->inp_flags & INP_DROPPED))
1849 tp = intotcpcb(inp);
1850 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1852 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1854 so = inp->inp_socket;
1855 SOCKBUF_LOCK(&so->so_snd);
1856 /* If the mss is larger than the socket buffer, decrease the mss. */
1857 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1858 tp->t_maxseg = so->so_snd.sb_hiwat;
1859 SOCKBUF_UNLOCK(&so->so_snd);
1861 TCPSTAT_INC(tcps_mturesent);
1863 tp->snd_nxt = tp->snd_una;
1864 tcp_free_sackholes(tp);
1865 tp->snd_recover = tp->snd_max;
1866 if (tp->t_flags & TF_SACK_PERMIT)
1867 EXIT_FASTRECOVERY(tp->t_flags);
1873 * Look-up the routing entry to the peer of this inpcb. If no route
1874 * is found and it cannot be allocated, then return 0. This routine
1875 * is called by TCP routines that access the rmx structure and by
1876 * tcp_mss_update to get the peer/interface MTU.
1879 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1882 struct sockaddr_in *dst;
1886 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1888 bzero(&sro, sizeof(sro));
1889 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1890 dst = (struct sockaddr_in *)&sro.ro_dst;
1891 dst->sin_family = AF_INET;
1892 dst->sin_len = sizeof(*dst);
1893 dst->sin_addr = inc->inc_faddr;
1894 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1896 if (sro.ro_rt != NULL) {
1897 ifp = sro.ro_rt->rt_ifp;
1898 if (sro.ro_rt->rt_mtu == 0)
1899 maxmtu = ifp->if_mtu;
1901 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu);
1903 /* Report additional interface capabilities. */
1905 if (ifp->if_capenable & IFCAP_TSO4 &&
1906 ifp->if_hwassist & CSUM_TSO) {
1907 cap->ifcap |= CSUM_TSO;
1908 cap->tsomax = ifp->if_hw_tsomax;
1909 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
1910 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
1921 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1923 struct route_in6 sro6;
1927 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1929 bzero(&sro6, sizeof(sro6));
1930 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1931 sro6.ro_dst.sin6_family = AF_INET6;
1932 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1933 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1934 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1936 if (sro6.ro_rt != NULL) {
1937 ifp = sro6.ro_rt->rt_ifp;
1938 if (sro6.ro_rt->rt_mtu == 0)
1939 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1941 maxmtu = min(sro6.ro_rt->rt_mtu,
1942 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1944 /* Report additional interface capabilities. */
1946 if (ifp->if_capenable & IFCAP_TSO6 &&
1947 ifp->if_hwassist & CSUM_TSO) {
1948 cap->ifcap |= CSUM_TSO;
1949 cap->tsomax = ifp->if_hw_tsomax;
1950 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
1951 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
1962 /* compute ESP/AH header size for TCP, including outer IP header. */
1964 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1971 struct ip6_hdr *ip6;
1975 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) ||
1976 (!key_havesp(IPSEC_DIR_OUTBOUND)))
1978 m = m_gethdr(M_NOWAIT, MT_DATA);
1983 if ((inp->inp_vflag & INP_IPV6) != 0) {
1984 ip6 = mtod(m, struct ip6_hdr *);
1985 th = (struct tcphdr *)(ip6 + 1);
1986 m->m_pkthdr.len = m->m_len =
1987 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1988 tcpip_fillheaders(inp, ip6, th);
1989 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1993 ip = mtod(m, struct ip *);
1994 th = (struct tcphdr *)(ip + 1);
1995 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1996 tcpip_fillheaders(inp, ip, th);
1997 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
2005 #ifdef TCP_SIGNATURE
2007 * Callback function invoked by m_apply() to digest TCP segment data
2008 * contained within an mbuf chain.
2011 tcp_signature_apply(void *fstate, void *data, u_int len)
2014 MD5Update(fstate, (u_char *)data, len);
2019 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2020 * search with the destination IP address, and a 'magic SPI' to be
2021 * determined by the application. This is hardcoded elsewhere to 1179
2024 tcp_get_sav(struct mbuf *m, u_int direction)
2026 union sockaddr_union dst;
2027 struct secasvar *sav;
2030 struct ip6_hdr *ip6;
2031 char ip6buf[INET6_ADDRSTRLEN];
2034 /* Extract the destination from the IP header in the mbuf. */
2035 bzero(&dst, sizeof(union sockaddr_union));
2036 ip = mtod(m, struct ip *);
2038 ip6 = NULL; /* Make the compiler happy. */
2043 dst.sa.sa_len = sizeof(struct sockaddr_in);
2044 dst.sa.sa_family = AF_INET;
2045 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
2046 ip->ip_src : ip->ip_dst;
2050 case (IPV6_VERSION >> 4):
2051 ip6 = mtod(m, struct ip6_hdr *);
2052 dst.sa.sa_len = sizeof(struct sockaddr_in6);
2053 dst.sa.sa_family = AF_INET6;
2054 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
2055 ip6->ip6_src : ip6->ip6_dst;
2064 /* Look up an SADB entry which matches the address of the peer. */
2065 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
2067 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
2068 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
2070 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2071 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2080 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2083 * m pointer to head of mbuf chain
2084 * len length of TCP segment data, excluding options
2085 * optlen length of TCP segment options
2086 * buf pointer to storage for computed MD5 digest
2087 * sav pointer to security assosiation
2089 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2090 * When called from tcp_input(), we can be sure that th_sum has been
2091 * zeroed out and verified already.
2093 * Releases reference to SADB key before return.
2095 * Return 0 if successful, otherwise return -1.
2099 tcp_signature_do_compute(struct mbuf *m, int len, int optlen,
2100 u_char *buf, struct secasvar *sav)
2103 struct ippseudo ippseudo;
2109 struct ipovly *ipovly;
2113 struct ip6_hdr *ip6;
2114 struct in6_addr in6;
2120 KASSERT(m != NULL, ("NULL mbuf chain"));
2121 KASSERT(buf != NULL, ("NULL signature pointer"));
2123 /* Extract the destination from the IP header in the mbuf. */
2124 ip = mtod(m, struct ip *);
2126 ip6 = NULL; /* Make the compiler happy. */
2131 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2133 * XXX The ippseudo header MUST be digested in network byte order,
2134 * or else we'll fail the regression test. Assume all fields we've
2135 * been doing arithmetic on have been in host byte order.
2136 * XXX One cannot depend on ipovly->ih_len here. When called from
2137 * tcp_output(), the underlying ip_len member has not yet been set.
2142 ipovly = (struct ipovly *)ip;
2143 ippseudo.ippseudo_src = ipovly->ih_src;
2144 ippseudo.ippseudo_dst = ipovly->ih_dst;
2145 ippseudo.ippseudo_pad = 0;
2146 ippseudo.ippseudo_p = IPPROTO_TCP;
2147 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2149 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2151 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2152 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2157 * RFC 2385, 2.0 Proposal
2158 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2159 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2160 * extended next header value (to form 32 bits), and 32-bit segment
2162 * Note: Upper-Layer Packet Length comes before Next Header.
2164 case (IPV6_VERSION >> 4):
2166 in6_clearscope(&in6);
2167 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2169 in6_clearscope(&in6);
2170 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2171 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2172 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2174 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2175 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2176 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2178 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2180 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2181 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2193 * Step 2: Update MD5 hash with TCP header, excluding options.
2194 * The TCP checksum must be set to zero.
2196 savecsum = th->th_sum;
2198 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2199 th->th_sum = savecsum;
2202 * Step 3: Update MD5 hash with TCP segment data.
2203 * Use m_apply() to avoid an early m_pullup().
2206 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2209 * Step 4: Update MD5 hash with shared secret.
2211 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2212 MD5Final(buf, &ctx);
2214 key_sa_recordxfer(sav, m);
2220 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2222 * Return 0 if successful, otherwise return -1.
2225 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
2226 u_char *buf, u_int direction)
2228 struct secasvar *sav;
2230 if ((sav = tcp_get_sav(m, direction)) == NULL)
2233 return (tcp_signature_do_compute(m, len, optlen, buf, sav));
2237 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2240 * m pointer to head of mbuf chain
2241 * len length of TCP segment data, excluding options
2242 * optlen length of TCP segment options
2243 * buf pointer to storage for computed MD5 digest
2244 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2246 * Return 1 if successful, otherwise return 0.
2249 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2250 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2252 char tmpdigest[TCP_SIGLEN];
2254 if (tcp_sig_checksigs == 0)
2256 if ((tcpbflag & TF_SIGNATURE) == 0) {
2257 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2260 * If this socket is not expecting signature but
2261 * the segment contains signature just fail.
2263 TCPSTAT_INC(tcps_sig_err_sigopt);
2264 TCPSTAT_INC(tcps_sig_rcvbadsig);
2268 /* Signature is not expected, and not present in segment. */
2273 * If this socket is expecting signature but the segment does not
2274 * contain any just fail.
2276 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2277 TCPSTAT_INC(tcps_sig_err_nosigopt);
2278 TCPSTAT_INC(tcps_sig_rcvbadsig);
2281 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2282 IPSEC_DIR_INBOUND) == -1) {
2283 TCPSTAT_INC(tcps_sig_err_buildsig);
2284 TCPSTAT_INC(tcps_sig_rcvbadsig);
2288 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2289 TCPSTAT_INC(tcps_sig_rcvbadsig);
2292 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2295 #endif /* TCP_SIGNATURE */
2298 sysctl_drop(SYSCTL_HANDLER_ARGS)
2300 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2301 struct sockaddr_storage addrs[2];
2305 struct sockaddr_in *fin, *lin;
2307 struct sockaddr_in6 *fin6, *lin6;
2318 if (req->oldptr != NULL || req->oldlen != 0)
2320 if (req->newptr == NULL)
2322 if (req->newlen < sizeof(addrs))
2324 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2328 switch (addrs[0].ss_family) {
2331 fin6 = (struct sockaddr_in6 *)&addrs[0];
2332 lin6 = (struct sockaddr_in6 *)&addrs[1];
2333 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2334 lin6->sin6_len != sizeof(struct sockaddr_in6))
2336 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2337 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2339 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2340 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2341 fin = (struct sockaddr_in *)&addrs[0];
2342 lin = (struct sockaddr_in *)&addrs[1];
2345 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2348 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2355 fin = (struct sockaddr_in *)&addrs[0];
2356 lin = (struct sockaddr_in *)&addrs[1];
2357 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2358 lin->sin_len != sizeof(struct sockaddr_in))
2365 INP_INFO_RLOCK(&V_tcbinfo);
2366 switch (addrs[0].ss_family) {
2369 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2370 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2371 INPLOOKUP_WLOCKPCB, NULL);
2376 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2377 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2382 if (inp->inp_flags & INP_TIMEWAIT) {
2384 * XXXRW: There currently exists a state where an
2385 * inpcb is present, but its timewait state has been
2386 * discarded. For now, don't allow dropping of this
2394 } else if (!(inp->inp_flags & INP_DROPPED) &&
2395 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2396 tp = intotcpcb(inp);
2397 tp = tcp_drop(tp, ECONNABORTED);
2404 INP_INFO_RUNLOCK(&V_tcbinfo);
2408 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2409 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL,
2410 0, sysctl_drop, "", "Drop TCP connection");
2413 * Generate a standardized TCP log line for use throughout the
2414 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2415 * allow use in the interrupt context.
2417 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2418 * NB: The function may return NULL if memory allocation failed.
2420 * Due to header inclusion and ordering limitations the struct ip
2421 * and ip6_hdr pointers have to be passed as void pointers.
2424 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2428 /* Is logging enabled? */
2429 if (tcp_log_in_vain == 0)
2432 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2436 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2440 /* Is logging enabled? */
2441 if (tcp_log_debug == 0)
2444 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2448 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2455 const struct ip6_hdr *ip6;
2457 ip6 = (const struct ip6_hdr *)ip6hdr;
2459 ip = (struct ip *)ip4hdr;
2462 * The log line looks like this:
2463 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2465 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2466 sizeof(PRINT_TH_FLAGS) + 1 +
2468 2 * INET6_ADDRSTRLEN;
2470 2 * INET_ADDRSTRLEN;
2473 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2477 strcat(s, "TCP: [");
2480 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2481 inet_ntoa_r(inc->inc_faddr, sp);
2483 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2485 inet_ntoa_r(inc->inc_laddr, sp);
2487 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2490 ip6_sprintf(sp, &inc->inc6_faddr);
2492 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2494 ip6_sprintf(sp, &inc->inc6_laddr);
2496 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2497 } else if (ip6 && th) {
2498 ip6_sprintf(sp, &ip6->ip6_src);
2500 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2502 ip6_sprintf(sp, &ip6->ip6_dst);
2504 sprintf(sp, "]:%i", ntohs(th->th_dport));
2507 } else if (ip && th) {
2508 inet_ntoa_r(ip->ip_src, sp);
2510 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2512 inet_ntoa_r(ip->ip_dst, sp);
2514 sprintf(sp, "]:%i", ntohs(th->th_dport));
2522 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2523 if (*(s + size - 1) != '\0')
2524 panic("%s: string too long", __func__);
2529 * A subroutine which makes it easy to track TCP state changes with DTrace.
2530 * This function shouldn't be called for t_state initializations that don't
2531 * correspond to actual TCP state transitions.
2534 tcp_state_change(struct tcpcb *tp, int newstate)
2536 #if defined(KDTRACE_HOOKS)
2537 int pstate = tp->t_state;
2540 tp->t_state = newstate;
2541 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);