2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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62 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
63 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $
66 #include "opt_compat.h"
68 #include "opt_inet6.h"
69 #include "opt_ipsec.h"
70 #include "opt_tcpdebug.h"
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/callout.h>
75 #include <sys/kernel.h>
76 #include <sys/sysctl.h>
77 #include <sys/malloc.h>
78 #include <sys/mpipe.h>
81 #include <sys/domain.h>
85 #include <sys/socket.h>
86 #include <sys/socketops.h>
87 #include <sys/socketvar.h>
88 #include <sys/protosw.h>
89 #include <sys/random.h>
90 #include <sys/in_cksum.h>
93 #include <net/route.h>
95 #include <net/netisr2.h>
98 #include <netinet/in.h>
99 #include <netinet/in_systm.h>
100 #include <netinet/ip.h>
101 #include <netinet/ip6.h>
102 #include <netinet/in_pcb.h>
103 #include <netinet6/in6_pcb.h>
104 #include <netinet/in_var.h>
105 #include <netinet/ip_var.h>
106 #include <netinet6/ip6_var.h>
107 #include <netinet/ip_icmp.h>
109 #include <netinet/icmp6.h>
111 #include <netinet/tcp.h>
112 #include <netinet/tcp_fsm.h>
113 #include <netinet/tcp_seq.h>
114 #include <netinet/tcp_timer.h>
115 #include <netinet/tcp_timer2.h>
116 #include <netinet/tcp_var.h>
117 #include <netinet6/tcp6_var.h>
118 #include <netinet/tcpip.h>
120 #include <netinet/tcp_debug.h>
122 #include <netinet6/ip6protosw.h>
125 #include <netinet6/ipsec.h>
126 #include <netproto/key/key.h>
128 #include <netinet6/ipsec6.h>
133 #include <netproto/ipsec/ipsec.h>
135 #include <netproto/ipsec/ipsec6.h>
141 #include <machine/smp.h>
143 #include <sys/msgport2.h>
144 #include <sys/mplock2.h>
145 #include <net/netmsg2.h>
147 #if !defined(KTR_TCP)
148 #define KTR_TCP KTR_ALL
151 KTR_INFO_MASTER(tcp);
152 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0);
153 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0);
154 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
155 #define logtcp(name) KTR_LOG(tcp_ ## name)
158 #define TCP_IW_MAXSEGS_DFLT 4
159 #define TCP_IW_CAPSEGS_DFLT 3
161 struct inpcbinfo tcbinfo[MAXCPU];
162 struct tcpcbackqhead tcpcbackq[MAXCPU];
164 static struct lwkt_token tcp_port_token =
165 LWKT_TOKEN_INITIALIZER(tcp_port_token);
167 int tcp_mssdflt = TCP_MSS;
168 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
169 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size");
172 int tcp_v6mssdflt = TCP6_MSS;
173 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW,
174 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6");
178 * Minimum MSS we accept and use. This prevents DoS attacks where
179 * we are forced to a ridiculous low MSS like 20 and send hundreds
180 * of packets instead of one. The effect scales with the available
181 * bandwidth and quickly saturates the CPU and network interface
182 * with packet generation and sending. Set to zero to disable MINMSS
183 * checking. This setting prevents us from sending too small packets.
185 int tcp_minmss = TCP_MINMSS;
186 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
187 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
190 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
191 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
192 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time");
195 int tcp_do_rfc1323 = 1;
196 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
197 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
199 static int tcp_tcbhashsize = 0;
200 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
201 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable");
203 static int do_tcpdrain = 1;
204 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
205 "Enable tcp_drain routine for extra help when low on mbufs");
207 static int icmp_may_rst = 1;
208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
209 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
211 static int tcp_isn_reseed_interval = 0;
212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
213 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
216 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on
217 * by default, but with generous values which should allow maximal
218 * bandwidth. In particular, the slop defaults to 50 (5 packets).
220 * The reason for doing this is that the limiter is the only mechanism we
221 * have which seems to do a really good job preventing receiver RX rings
222 * on network interfaces from getting blown out. Even though GigE/10GigE
223 * is supposed to flow control it looks like either it doesn't actually
224 * do it or Open Source drivers do not properly enable it.
226 * People using the limiter to reduce bottlenecks on slower WAN connections
227 * should set the slop to 20 (2 packets).
229 static int tcp_inflight_enable = 1;
230 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
231 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
233 static int tcp_inflight_debug = 0;
234 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
235 &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
237 static int tcp_inflight_min = 6144;
238 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
239 &tcp_inflight_min, 0, "Lower bound for TCP inflight window");
241 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
242 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
243 &tcp_inflight_max, 0, "Upper bound for TCP inflight window");
245 static int tcp_inflight_stab = 50;
246 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
247 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)");
249 static int tcp_do_rfc3390 = 1;
250 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
252 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
254 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
255 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
256 &tcp_iw_maxsegs, 0, "TCP IW segments max");
258 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
259 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
260 &tcp_iw_capsegs, 0, "TCP IW segments");
262 int tcp_low_rtobase = 1;
263 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW,
264 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)");
266 static int tcp_do_ncr = 1;
267 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW,
268 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)");
270 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
271 static struct malloc_pipe tcptemp_mpipe;
273 static void tcp_willblock(void);
274 static void tcp_notify (struct inpcb *, int);
276 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign;
279 sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
283 for (cpu = 0; cpu < ncpus; ++cpu) {
284 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
285 sizeof(struct tcp_stats))))
287 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
288 sizeof(struct tcp_stats))))
294 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
295 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
298 * Target size of TCP PCB hash tables. Must be a power of two.
300 * Note that this can be overridden by the kernel environment
301 * variable net.inet.tcp.tcbhashsize
304 #define TCBHASHSIZE 512
308 * This is the actual shape of what we allocate using the zone
309 * allocator. Doing it this way allows us to protect both structures
310 * using the same generation count, and also eliminates the overhead
311 * of allocating tcpcbs separately. By hiding the structure here,
312 * we avoid changing most of the rest of the code (although it needs
313 * to be changed, eventually, for greater efficiency).
316 #define ALIGNM1 (ALIGNMENT - 1)
320 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
323 struct tcp_callout inp_tp_rexmt;
324 struct tcp_callout inp_tp_persist;
325 struct tcp_callout inp_tp_keep;
326 struct tcp_callout inp_tp_2msl;
327 struct tcp_callout inp_tp_delack;
328 struct netmsg_tcp_timer inp_tp_timermsg;
329 struct netmsg_base inp_tp_sndmore;
340 struct inpcbporthead *porthashbase;
341 struct inpcbinfo *ticb;
343 int hashsize = TCBHASHSIZE;
347 * note: tcptemp is used for keepalives, and it is ok for an
348 * allocation to fail so do not specify MPF_INT.
350 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
351 25, -1, 0, NULL, NULL, NULL);
353 tcp_delacktime = TCPTV_DELACK;
354 tcp_keepinit = TCPTV_KEEP_INIT;
355 tcp_keepidle = TCPTV_KEEP_IDLE;
356 tcp_keepintvl = TCPTV_KEEPINTVL;
357 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
359 tcp_rexmit_min = TCPTV_MIN;
360 tcp_rexmit_slop = TCPTV_CPU_VAR;
362 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
363 if (!powerof2(hashsize)) {
364 kprintf("WARNING: TCB hash size not a power of 2\n");
365 hashsize = 512; /* safe default */
367 tcp_tcbhashsize = hashsize;
368 porthashbase = hashinit(hashsize, M_PCB, &porthashmask);
370 for (cpu = 0; cpu < ncpus2; cpu++) {
371 ticb = &tcbinfo[cpu];
372 in_pcbinfo_init(ticb);
374 ticb->hashbase = hashinit(hashsize, M_PCB,
376 ticb->porthashbase = porthashbase;
377 ticb->porthashmask = porthashmask;
378 ticb->porttoken = &tcp_port_token;
380 ticb->porthashbase = hashinit(hashsize, M_PCB,
381 &ticb->porthashmask);
383 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
384 &ticb->wildcardhashmask);
385 ticb->localgrphashbase = hashinit(hashsize, M_PCB,
386 &ticb->localgrphashmask);
387 ticb->ipi_size = sizeof(struct inp_tp);
388 TAILQ_INIT(&tcpcbackq[cpu]);
391 tcp_reass_maxseg = nmbclusters / 16;
392 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg);
395 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
397 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
399 if (max_protohdr < TCP_MINPROTOHDR)
400 max_protohdr = TCP_MINPROTOHDR;
401 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
403 #undef TCP_MINPROTOHDR
406 * Initialize TCP statistics counters for each CPU.
408 for (cpu = 0; cpu < ncpus; ++cpu) {
409 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
413 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP);
420 int cpu = mycpu->gd_cpuid;
422 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) {
423 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
424 tp->t_flags &= ~TF_ONOUTPUTQ;
425 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq);
431 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
432 * tcp_template used to store this data in mbufs, but we now recopy it out
433 * of the tcpcb each time to conserve mbufs.
436 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso)
438 struct inpcb *inp = tp->t_inpcb;
439 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
442 if (inp->inp_vflag & INP_IPV6) {
445 ip6 = (struct ip6_hdr *)ip_ptr;
446 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
447 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
448 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
449 (IPV6_VERSION & IPV6_VERSION_MASK);
450 ip6->ip6_nxt = IPPROTO_TCP;
451 ip6->ip6_plen = sizeof(struct tcphdr);
452 ip6->ip6_src = inp->in6p_laddr;
453 ip6->ip6_dst = inp->in6p_faddr;
458 struct ip *ip = (struct ip *) ip_ptr;
461 ip->ip_vhl = IP_VHL_BORING;
468 ip->ip_p = IPPROTO_TCP;
469 ip->ip_src = inp->inp_laddr;
470 ip->ip_dst = inp->inp_faddr;
473 plen = htons(IPPROTO_TCP);
475 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP);
476 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
477 ip->ip_dst.s_addr, plen);
480 tcp_hdr->th_sport = inp->inp_lport;
481 tcp_hdr->th_dport = inp->inp_fport;
486 tcp_hdr->th_flags = 0;
492 * Create template to be used to send tcp packets on a connection.
493 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
494 * use for this function is in keepalives, which use tcp_respond.
497 tcp_maketemplate(struct tcpcb *tp)
501 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
503 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE);
508 tcp_freetemplate(struct tcptemp *tmp)
510 mpipe_free(&tcptemp_mpipe, tmp);
514 * Send a single message to the TCP at address specified by
515 * the given TCP/IP header. If m == NULL, then we make a copy
516 * of the tcpiphdr at ti and send directly to the addressed host.
517 * This is used to force keep alive messages out using the TCP
518 * template for a connection. If flags are given then we send
519 * a message back to the TCP which originated the * segment ti,
520 * and discard the mbuf containing it and any other attached mbufs.
522 * In any case the ack and sequence number of the transmitted
523 * segment are as specified by the parameters.
525 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
528 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
529 tcp_seq ack, tcp_seq seq, int flags)
533 struct route *ro = NULL;
535 struct ip *ip = ipgen;
538 struct route_in6 *ro6 = NULL;
539 struct route_in6 sro6;
540 struct ip6_hdr *ip6 = ipgen;
541 boolean_t use_tmpro = TRUE;
543 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
545 const boolean_t isipv6 = FALSE;
549 if (!(flags & TH_RST)) {
550 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv);
553 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
554 win = (long)TCP_MAXWIN << tp->rcv_scale;
557 * Don't use the route cache of a listen socket,
558 * it is not MPSAFE; use temporary route cache.
560 if (tp->t_state != TCPS_LISTEN) {
562 ro6 = &tp->t_inpcb->in6p_route;
564 ro = &tp->t_inpcb->inp_route;
571 bzero(ro6, sizeof *ro6);
574 bzero(ro, sizeof *ro);
578 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
582 m->m_data += max_linkhdr;
584 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
585 ip6 = mtod(m, struct ip6_hdr *);
586 nth = (struct tcphdr *)(ip6 + 1);
588 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
589 ip = mtod(m, struct ip *);
590 nth = (struct tcphdr *)(ip + 1);
592 bcopy(th, nth, sizeof(struct tcphdr));
597 m->m_data = (caddr_t)ipgen;
598 /* m_len is set later */
600 #define xchg(a, b, type) { type t; t = a; a = b; b = t; }
602 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
603 nth = (struct tcphdr *)(ip6 + 1);
605 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
606 nth = (struct tcphdr *)(ip + 1);
610 * this is usually a case when an extension header
611 * exists between the IPv6 header and the
614 nth->th_sport = th->th_sport;
615 nth->th_dport = th->th_dport;
617 xchg(nth->th_dport, nth->th_sport, n_short);
622 ip6->ip6_vfc = IPV6_VERSION;
623 ip6->ip6_nxt = IPPROTO_TCP;
624 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
625 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
627 tlen += sizeof(struct tcpiphdr);
629 ip->ip_ttl = ip_defttl;
632 m->m_pkthdr.len = tlen;
633 m->m_pkthdr.rcvif = NULL;
634 nth->th_seq = htonl(seq);
635 nth->th_ack = htonl(ack);
637 nth->th_off = sizeof(struct tcphdr) >> 2;
638 nth->th_flags = flags;
640 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
642 nth->th_win = htons((u_short)win);
646 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
647 sizeof(struct ip6_hdr),
648 tlen - sizeof(struct ip6_hdr));
649 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
650 (ro6 && ro6->ro_rt) ?
651 ro6->ro_rt->rt_ifp : NULL);
653 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
654 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
655 m->m_pkthdr.csum_flags = CSUM_TCP;
656 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
657 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr);
660 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
661 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
664 ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
665 tp ? tp->t_inpcb : NULL);
666 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
671 ipflags |= IP_DEBUGROUTE;
672 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
673 if ((ro == &sro) && (ro->ro_rt != NULL)) {
681 * Create a new TCP control block, making an
682 * empty reassembly queue and hooking it to the argument
683 * protocol control block. The `inp' parameter must have
684 * come from the zone allocator set up in tcp_init().
687 tcp_newtcpcb(struct inpcb *inp)
692 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
694 const boolean_t isipv6 = FALSE;
697 it = (struct inp_tp *)inp;
699 bzero(tp, sizeof(struct tcpcb));
700 TAILQ_INIT(&tp->t_segq);
701 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
702 tp->t_rxtthresh = tcprexmtthresh;
704 /* Set up our timeouts. */
705 tp->tt_rexmt = &it->inp_tp_rexmt;
706 tp->tt_persist = &it->inp_tp_persist;
707 tp->tt_keep = &it->inp_tp_keep;
708 tp->tt_2msl = &it->inp_tp_2msl;
709 tp->tt_delack = &it->inp_tp_delack;
713 * Zero out timer message. We don't create it here,
714 * since the current CPU may not be the owner of this
717 tp->tt_msg = &it->inp_tp_timermsg;
718 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
720 tp->t_keepinit = tcp_keepinit;
721 tp->t_keepidle = tcp_keepidle;
722 tp->t_keepintvl = tcp_keepintvl;
723 tp->t_keepcnt = tcp_keepcnt;
724 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
727 tp->t_flags |= TF_NCR;
729 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP);
731 tp->t_inpcb = inp; /* XXX */
732 tp->t_state = TCPS_CLOSED;
734 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
735 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
736 * reasonable initial retransmit time.
738 tp->t_srtt = TCPTV_SRTTBASE;
740 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
741 tp->t_rttmin = tcp_rexmit_min;
742 tp->t_rxtcur = TCPTV_RTOBASE;
743 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
744 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
745 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
746 tp->snd_last = ticks;
747 tp->t_rcvtime = ticks;
749 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
750 * because the socket may be bound to an IPv6 wildcard address,
751 * which may match an IPv4-mapped IPv6 address.
753 inp->inp_ip_ttl = ip_defttl;
755 tcp_sack_tcpcb_init(tp);
757 tp->tt_sndmore = &it->inp_tp_sndmore;
760 return (tp); /* XXX */
764 * Drop a TCP connection, reporting the specified error.
765 * If connection is synchronized, then send a RST to peer.
768 tcp_drop(struct tcpcb *tp, int error)
770 struct socket *so = tp->t_inpcb->inp_socket;
772 if (TCPS_HAVERCVDSYN(tp->t_state)) {
773 tp->t_state = TCPS_CLOSED;
775 tcpstat.tcps_drops++;
777 tcpstat.tcps_conndrops++;
778 if (error == ETIMEDOUT && tp->t_softerror)
779 error = tp->t_softerror;
780 so->so_error = error;
781 return (tcp_close(tp));
784 struct netmsg_listen_detach {
785 struct netmsg_base base;
787 struct tcpcb *nm_tp_inh;
791 tcp_listen_detach_handler(netmsg_t msg)
793 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
794 struct tcpcb *tp = nmsg->nm_tp;
795 int cpu = mycpuid, nextcpu;
797 if (tp->t_flags & TF_LISTEN)
798 syncache_destroy(tp, nmsg->nm_tp_inh);
800 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
803 if (nextcpu < ncpus2)
804 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg);
806 lwkt_replymsg(&nmsg->base.lmsg, 0);
810 * Close a TCP control block:
811 * discard all space held by the tcp
812 * discard internet protocol block
813 * wake up any sleepers
816 tcp_close(struct tcpcb *tp)
819 struct inpcb *inp = tp->t_inpcb;
820 struct inpcb *inp_inh = NULL;
821 struct tcpcb *tp_inh = NULL;
822 struct socket *so = inp->inp_socket;
824 boolean_t dosavessthresh;
826 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
827 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
829 const boolean_t isipv6 = FALSE;
832 if (tp->t_flags & TF_LISTEN) {
834 * Pending socket/syncache inheritance
836 * If this is a listen(2) socket, find another listen(2)
837 * socket in the same local group, which could inherit
838 * the syncache and sockets pending on the completion
839 * and incompletion queues.
842 * Currently the inheritance could only happen on the
843 * listen(2) sockets w/ SO_REUSEPORT set.
845 KASSERT(&curthread->td_msgport == netisr_cpuport(0),
846 ("listen socket close not in netisr0"));
847 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp);
849 tp_inh = intotcpcb(inp_inh);
853 * INP_WILDCARD_MP indicates that listen(2) has been called on
854 * this socket. This implies:
855 * - A wildcard inp's hash is replicated for each protocol thread.
856 * - Syncache for this inp grows independently in each protocol
858 * - There is more than one cpu
860 * We have to chain a message to the rest of the protocol threads
861 * to cleanup the wildcard hash and the syncache. The cleanup
862 * in the current protocol thread is defered till the end of this
866 * After cleanup the inp's hash and syncache entries, this inp will
867 * no longer be available to the rest of the protocol threads, so we
868 * are safe to whack the inp in the following code.
870 if (inp->inp_flags & INP_WILDCARD_MP) {
871 struct netmsg_listen_detach nmsg;
873 KKASSERT(so->so_port == netisr_cpuport(0));
874 KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
875 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
877 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
878 MSGF_PRIORITY, tcp_listen_detach_handler);
880 nmsg.nm_tp_inh = tp_inh;
881 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0);
883 inp->inp_flags &= ~INP_WILDCARD_MP;
886 KKASSERT(tp->t_state != TCPS_TERMINATING);
887 tp->t_state = TCPS_TERMINATING;
890 * Make sure that all of our timers are stopped before we
891 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
892 * timers are never used. If timer message is never created
893 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
895 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
896 tcp_callout_stop(tp, tp->tt_rexmt);
897 tcp_callout_stop(tp, tp->tt_persist);
898 tcp_callout_stop(tp, tp->tt_keep);
899 tcp_callout_stop(tp, tp->tt_2msl);
900 tcp_callout_stop(tp, tp->tt_delack);
903 if (tp->t_flags & TF_ONOUTPUTQ) {
904 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
905 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
906 tp->t_flags &= ~TF_ONOUTPUTQ;
910 * If we got enough samples through the srtt filter,
911 * save the rtt and rttvar in the routing entry.
912 * 'Enough' is arbitrarily defined as the 16 samples.
913 * 16 samples is enough for the srtt filter to converge
914 * to within 5% of the correct value; fewer samples and
915 * we could save a very bogus rtt.
917 * Don't update the default route's characteristics and don't
918 * update anything that the user "locked".
920 if (tp->t_rttupdated >= 16) {
924 struct sockaddr_in6 *sin6;
926 if ((rt = inp->in6p_route.ro_rt) == NULL)
928 sin6 = (struct sockaddr_in6 *)rt_key(rt);
929 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
932 if ((rt = inp->inp_route.ro_rt) == NULL ||
933 ((struct sockaddr_in *)rt_key(rt))->
934 sin_addr.s_addr == INADDR_ANY)
937 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
938 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
939 if (rt->rt_rmx.rmx_rtt && i)
941 * filter this update to half the old & half
942 * the new values, converting scale.
943 * See route.h and tcp_var.h for a
944 * description of the scaling constants.
947 (rt->rt_rmx.rmx_rtt + i) / 2;
949 rt->rt_rmx.rmx_rtt = i;
950 tcpstat.tcps_cachedrtt++;
952 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
954 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
955 if (rt->rt_rmx.rmx_rttvar && i)
956 rt->rt_rmx.rmx_rttvar =
957 (rt->rt_rmx.rmx_rttvar + i) / 2;
959 rt->rt_rmx.rmx_rttvar = i;
960 tcpstat.tcps_cachedrttvar++;
963 * The old comment here said:
964 * update the pipelimit (ssthresh) if it has been updated
965 * already or if a pipesize was specified & the threshhold
966 * got below half the pipesize. I.e., wait for bad news
967 * before we start updating, then update on both good
970 * But we want to save the ssthresh even if no pipesize is
971 * specified explicitly in the route, because such
972 * connections still have an implicit pipesize specified
973 * by the global tcp_sendspace. In the absence of a reliable
974 * way to calculate the pipesize, it will have to do.
976 i = tp->snd_ssthresh;
977 if (rt->rt_rmx.rmx_sendpipe != 0)
978 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
980 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
981 if (dosavessthresh ||
982 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
983 (rt->rt_rmx.rmx_ssthresh != 0))) {
985 * convert the limit from user data bytes to
986 * packets then to packet data bytes.
988 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
993 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
994 sizeof(struct tcpiphdr));
995 if (rt->rt_rmx.rmx_ssthresh)
996 rt->rt_rmx.rmx_ssthresh =
997 (rt->rt_rmx.rmx_ssthresh + i) / 2;
999 rt->rt_rmx.rmx_ssthresh = i;
1000 tcpstat.tcps_cachedssthresh++;
1005 /* free the reassembly queue, if any */
1006 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) {
1007 TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
1010 atomic_add_int(&tcp_reass_qsize, -1);
1012 /* throw away SACK blocks in scoreboard*/
1013 if (TCP_DO_SACK(tp))
1014 tcp_sack_destroy(&tp->scb);
1016 inp->inp_ppcb = NULL;
1017 soisdisconnected(so);
1018 /* note: pcb detached later on */
1020 tcp_destroy_timermsg(tp);
1021 tcp_output_cancel(tp);
1023 if (tp->t_flags & TF_LISTEN) {
1024 syncache_destroy(tp, tp_inh);
1025 if (inp_inh != NULL && inp_inh->inp_socket != NULL) {
1027 * Pending sockets inheritance only needs
1028 * to be done once in the current thread,
1031 soinherit(so, inp_inh->inp_socket);
1035 so_async_rcvd_drop(so);
1036 /* Drop the reference for the asynchronized pru_rcvd */
1041 * pcbdetach removes any wildcard hash entry on the current CPU.
1050 tcpstat.tcps_closed++;
1054 static __inline void
1055 tcp_drain_oncpu(struct inpcbhead *head)
1057 struct inpcb *marker;
1060 struct tseg_qent *te;
1063 * Allows us to block while running the list
1065 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1066 marker->inp_flags |= INP_PLACEMARKER;
1067 LIST_INSERT_HEAD(head, marker, inp_list);
1069 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) {
1070 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1071 (tcpb = intotcpcb(inpb)) != NULL &&
1072 (te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) {
1073 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q);
1074 if (te->tqe_th->th_flags & TH_FIN)
1075 tcpb->t_flags &= ~TF_QUEDFIN;
1078 atomic_add_int(&tcp_reass_qsize, -1);
1081 LIST_REMOVE(marker, inp_list);
1082 LIST_INSERT_AFTER(inpb, marker, inp_list);
1085 LIST_REMOVE(marker, inp_list);
1086 kfree(marker, M_TEMP);
1089 struct netmsg_tcp_drain {
1090 struct netmsg_base base;
1091 struct inpcbhead *nm_head;
1095 tcp_drain_handler(netmsg_t msg)
1097 struct netmsg_tcp_drain *nm = (void *)msg;
1099 tcp_drain_oncpu(nm->nm_head);
1100 lwkt_replymsg(&nm->base.lmsg, 0);
1112 * Walk the tcpbs, if existing, and flush the reassembly queue,
1113 * if there is one...
1114 * XXX: The "Net/3" implementation doesn't imply that the TCP
1115 * reassembly queue should be flushed, but in a situation
1116 * where we're really low on mbufs, this is potentially
1119 for (cpu = 0; cpu < ncpus2; cpu++) {
1120 struct netmsg_tcp_drain *nm;
1122 if (cpu == mycpu->gd_cpuid) {
1123 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead);
1125 nm = kmalloc(sizeof(struct netmsg_tcp_drain),
1126 M_LWKTMSG, M_NOWAIT);
1129 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1130 0, tcp_drain_handler);
1131 nm->nm_head = &tcbinfo[cpu].pcblisthead;
1132 lwkt_sendmsg(netisr_cpuport(cpu), &nm->base.lmsg);
1138 * Notify a tcp user of an asynchronous error;
1139 * store error as soft error, but wake up user
1140 * (for now, won't do anything until can select for soft error).
1142 * Do not wake up user since there currently is no mechanism for
1143 * reporting soft errors (yet - a kqueue filter may be added).
1146 tcp_notify(struct inpcb *inp, int error)
1148 struct tcpcb *tp = intotcpcb(inp);
1151 * Ignore some errors if we are hooked up.
1152 * If connection hasn't completed, has retransmitted several times,
1153 * and receives a second error, give up now. This is better
1154 * than waiting a long time to establish a connection that
1155 * can never complete.
1157 if (tp->t_state == TCPS_ESTABLISHED &&
1158 (error == EHOSTUNREACH || error == ENETUNREACH ||
1159 error == EHOSTDOWN)) {
1161 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1163 tcp_drop(tp, error);
1165 tp->t_softerror = error;
1167 wakeup(&so->so_timeo);
1174 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1177 struct inpcb *marker;
1186 * The process of preparing the TCB list is too time-consuming and
1187 * resource-intensive to repeat twice on every request.
1189 if (req->oldptr == NULL) {
1190 for (ccpu = 0; ccpu < ncpus; ++ccpu) {
1191 gd = globaldata_find(ccpu);
1192 n += tcbinfo[gd->gd_cpuid].ipi_count;
1194 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1198 if (req->newptr != NULL)
1201 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1202 marker->inp_flags |= INP_PLACEMARKER;
1205 * OK, now we're committed to doing something. Run the inpcb list
1206 * for each cpu in the system and construct the output. Use a
1207 * list placemarker to deal with list changes occuring during
1208 * copyout blockages (but otherwise depend on being on the correct
1209 * cpu to avoid races).
1211 origcpu = mycpu->gd_cpuid;
1212 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) {
1218 cpu_id = (origcpu + ccpu) % ncpus;
1219 if ((smp_active_mask & CPUMASK(cpu_id)) == 0)
1221 rgd = globaldata_find(cpu_id);
1222 lwkt_setcpu_self(rgd);
1224 n = tcbinfo[cpu_id].ipi_count;
1226 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list);
1228 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1230 * process a snapshot of pcbs, ignoring placemarkers
1231 * and using our own to allow SYSCTL_OUT to block.
1233 LIST_REMOVE(marker, inp_list);
1234 LIST_INSERT_AFTER(inp, marker, inp_list);
1236 if (inp->inp_flags & INP_PLACEMARKER)
1238 if (prison_xinpcb(req->td, inp))
1241 xt.xt_len = sizeof xt;
1242 bcopy(inp, &xt.xt_inp, sizeof *inp);
1243 inp_ppcb = inp->inp_ppcb;
1244 if (inp_ppcb != NULL)
1245 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1247 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1248 if (inp->inp_socket)
1249 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1250 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1254 LIST_REMOVE(marker, inp_list);
1255 if (error == 0 && i < n) {
1256 bzero(&xt, sizeof xt);
1257 xt.xt_len = sizeof xt;
1259 error = SYSCTL_OUT(req, &xt, sizeof xt);
1268 * Make sure we are on the same cpu we were on originally, since
1269 * higher level callers expect this. Also don't pollute caches with
1270 * migrated userland data by (eventually) returning to userland
1271 * on a different cpu.
1273 lwkt_setcpu_self(globaldata_find(origcpu));
1274 kfree(marker, M_TEMP);
1278 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1279 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1282 tcp_getcred(SYSCTL_HANDLER_ARGS)
1284 struct sockaddr_in addrs[2];
1289 error = priv_check(req->td, PRIV_ROOT);
1292 error = SYSCTL_IN(req, addrs, sizeof addrs);
1296 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1297 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1298 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1299 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1300 if (inp == NULL || inp->inp_socket == NULL) {
1304 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1310 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1311 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1315 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1317 struct sockaddr_in6 addrs[2];
1320 boolean_t mapped = FALSE;
1322 error = priv_check(req->td, PRIV_ROOT);
1325 error = SYSCTL_IN(req, addrs, sizeof addrs);
1328 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1329 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1336 inp = in_pcblookup_hash(&tcbinfo[0],
1337 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1339 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1343 inp = in6_pcblookup_hash(&tcbinfo[0],
1344 &addrs[1].sin6_addr, addrs[1].sin6_port,
1345 &addrs[0].sin6_addr, addrs[0].sin6_port,
1348 if (inp == NULL || inp->inp_socket == NULL) {
1352 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1358 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1360 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1363 struct netmsg_tcp_notify {
1364 struct netmsg_base base;
1365 void (*nm_notify)(struct inpcb *, int);
1366 struct in_addr nm_faddr;
1371 tcp_notifyall_oncpu(netmsg_t msg)
1373 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1376 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr,
1377 nm->nm_arg, nm->nm_notify);
1379 nextcpu = mycpuid + 1;
1380 if (nextcpu < ncpus2)
1381 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg);
1383 lwkt_replymsg(&nm->base.lmsg, 0);
1387 tcp_ctlinput(netmsg_t msg)
1389 int cmd = msg->ctlinput.nm_cmd;
1390 struct sockaddr *sa = msg->ctlinput.nm_arg;
1391 struct ip *ip = msg->ctlinput.nm_extra;
1393 struct in_addr faddr;
1396 void (*notify)(struct inpcb *, int) = tcp_notify;
1400 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1404 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1405 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1408 arg = inetctlerrmap[cmd];
1409 if (cmd == PRC_QUENCH) {
1410 notify = tcp_quench;
1411 } else if (icmp_may_rst &&
1412 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1413 cmd == PRC_UNREACH_PORT ||
1414 cmd == PRC_TIMXCEED_INTRANS) &&
1416 notify = tcp_drop_syn_sent;
1417 } else if (cmd == PRC_MSGSIZE) {
1418 struct icmp *icmp = (struct icmp *)
1419 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1421 arg = ntohs(icmp->icmp_nextmtu);
1422 notify = tcp_mtudisc;
1423 } else if (PRC_IS_REDIRECT(cmd)) {
1425 notify = in_rtchange;
1426 } else if (cmd == PRC_HOSTDEAD) {
1432 th = (struct tcphdr *)((caddr_t)ip +
1433 (IP_VHL_HL(ip->ip_vhl) << 2));
1434 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
1435 ip->ip_src.s_addr, th->th_sport);
1436 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
1437 ip->ip_src, th->th_sport, 0, NULL);
1438 if ((inp != NULL) && (inp->inp_socket != NULL)) {
1439 icmpseq = htonl(th->th_seq);
1440 tp = intotcpcb(inp);
1441 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1442 SEQ_LT(icmpseq, tp->snd_max))
1443 (*notify)(inp, arg);
1445 struct in_conninfo inc;
1447 inc.inc_fport = th->th_dport;
1448 inc.inc_lport = th->th_sport;
1449 inc.inc_faddr = faddr;
1450 inc.inc_laddr = ip->ip_src;
1454 syncache_unreach(&inc, th);
1458 struct netmsg_tcp_notify *nm;
1460 KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
1461 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1462 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1463 0, tcp_notifyall_oncpu);
1464 nm->nm_faddr = faddr;
1466 nm->nm_notify = notify;
1468 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg);
1471 lwkt_replymsg(&msg->lmsg, 0);
1477 tcp6_ctlinput(netmsg_t msg)
1479 int cmd = msg->ctlinput.nm_cmd;
1480 struct sockaddr *sa = msg->ctlinput.nm_arg;
1481 void *d = msg->ctlinput.nm_extra;
1483 void (*notify) (struct inpcb *, int) = tcp_notify;
1484 struct ip6_hdr *ip6;
1486 struct ip6ctlparam *ip6cp = NULL;
1487 const struct sockaddr_in6 *sa6_src = NULL;
1489 struct tcp_portonly {
1495 if (sa->sa_family != AF_INET6 ||
1496 sa->sa_len != sizeof(struct sockaddr_in6)) {
1501 if (cmd == PRC_QUENCH)
1502 notify = tcp_quench;
1503 else if (cmd == PRC_MSGSIZE) {
1504 struct ip6ctlparam *ip6cp = d;
1505 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1507 arg = ntohl(icmp6->icmp6_mtu);
1508 notify = tcp_mtudisc;
1509 } else if (!PRC_IS_REDIRECT(cmd) &&
1510 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1514 /* if the parameter is from icmp6, decode it. */
1516 ip6cp = (struct ip6ctlparam *)d;
1518 ip6 = ip6cp->ip6c_ip6;
1519 off = ip6cp->ip6c_off;
1520 sa6_src = ip6cp->ip6c_src;
1524 off = 0; /* fool gcc */
1529 struct in_conninfo inc;
1531 * XXX: We assume that when IPV6 is non NULL,
1532 * M and OFF are valid.
1535 /* check if we can safely examine src and dst ports */
1536 if (m->m_pkthdr.len < off + sizeof *thp)
1539 bzero(&th, sizeof th);
1540 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
1542 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport,
1543 (struct sockaddr *)ip6cp->ip6c_src,
1544 th.th_sport, cmd, arg, notify);
1546 inc.inc_fport = th.th_dport;
1547 inc.inc_lport = th.th_sport;
1548 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1549 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1551 syncache_unreach(&inc, &th);
1553 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0,
1554 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1557 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1563 * Following is where TCP initial sequence number generation occurs.
1565 * There are two places where we must use initial sequence numbers:
1566 * 1. In SYN-ACK packets.
1567 * 2. In SYN packets.
1569 * All ISNs for SYN-ACK packets are generated by the syncache. See
1570 * tcp_syncache.c for details.
1572 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1573 * depends on this property. In addition, these ISNs should be
1574 * unguessable so as to prevent connection hijacking. To satisfy
1575 * the requirements of this situation, the algorithm outlined in
1576 * RFC 1948 is used to generate sequence numbers.
1578 * Implementation details:
1580 * Time is based off the system timer, and is corrected so that it
1581 * increases by one megabyte per second. This allows for proper
1582 * recycling on high speed LANs while still leaving over an hour
1585 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1586 * between seeding of isn_secret. This is normally set to zero,
1587 * as reseeding should not be necessary.
1591 #define ISN_BYTES_PER_SECOND 1048576
1593 u_char isn_secret[32];
1594 int isn_last_reseed;
1598 tcp_new_isn(struct tcpcb *tp)
1600 u_int32_t md5_buffer[4];
1603 /* Seed if this is the first use, reseed if requested. */
1604 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1605 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1607 read_random_unlimited(&isn_secret, sizeof isn_secret);
1608 isn_last_reseed = ticks;
1611 /* Compute the md5 hash and return the ISN. */
1613 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1614 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
1616 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
1617 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1618 sizeof(struct in6_addr));
1619 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1620 sizeof(struct in6_addr));
1624 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1625 sizeof(struct in_addr));
1626 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1627 sizeof(struct in_addr));
1629 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1630 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1631 new_isn = (tcp_seq) md5_buffer[0];
1632 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
1637 * When a source quench is received, close congestion window
1638 * to one segment. We will gradually open it again as we proceed.
1641 tcp_quench(struct inpcb *inp, int error)
1643 struct tcpcb *tp = intotcpcb(inp);
1646 tp->snd_cwnd = tp->t_maxseg;
1652 * When a specific ICMP unreachable message is received and the
1653 * connection state is SYN-SENT, drop the connection. This behavior
1654 * is controlled by the icmp_may_rst sysctl.
1657 tcp_drop_syn_sent(struct inpcb *inp, int error)
1659 struct tcpcb *tp = intotcpcb(inp);
1661 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
1662 tcp_drop(tp, error);
1666 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1667 * based on the new value in the route. Also nudge TCP to send something,
1668 * since we know the packet we just sent was dropped.
1669 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1672 tcp_mtudisc(struct inpcb *inp, int mtu)
1674 struct tcpcb *tp = intotcpcb(inp);
1676 struct socket *so = inp->inp_socket;
1679 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1681 const boolean_t isipv6 = FALSE;
1688 * If no MTU is provided in the ICMP message, use the
1689 * next lower likely value, as specified in RFC 1191.
1694 oldmtu = tp->t_maxopd +
1696 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1697 sizeof(struct tcpiphdr));
1698 mtu = ip_next_mtu(oldmtu, 0);
1702 rt = tcp_rtlookup6(&inp->inp_inc);
1704 rt = tcp_rtlookup(&inp->inp_inc);
1706 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1707 mtu = rt->rt_rmx.rmx_mtu;
1711 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1712 sizeof(struct tcpiphdr));
1715 * XXX - The following conditional probably violates the TCP
1716 * spec. The problem is that, since we don't know the
1717 * other end's MSS, we are supposed to use a conservative
1718 * default. But, if we do that, then MTU discovery will
1719 * never actually take place, because the conservative
1720 * default is much less than the MTUs typically seen
1721 * on the Internet today. For the moment, we'll sweep
1722 * this under the carpet.
1724 * The conservative default might not actually be a problem
1725 * if the only case this occurs is when sending an initial
1726 * SYN with options and data to a host we've never talked
1727 * to before. Then, they will reply with an MSS value which
1728 * will get recorded and the new parameters should get
1729 * recomputed. For Further Study.
1731 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1732 maxopd = rt->rt_rmx.rmx_mssopt;
1736 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1737 sizeof(struct tcpiphdr));
1739 if (tp->t_maxopd <= maxopd)
1741 tp->t_maxopd = maxopd;
1744 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1745 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1746 mss -= TCPOLEN_TSTAMP_APPA;
1748 /* round down to multiple of MCLBYTES */
1749 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1751 mss &= ~(MCLBYTES - 1);
1754 mss = (mss / MCLBYTES) * MCLBYTES;
1757 if (so->so_snd.ssb_hiwat < mss)
1758 mss = so->so_snd.ssb_hiwat;
1762 tp->snd_nxt = tp->snd_una;
1764 tcpstat.tcps_mturesent++;
1768 * Look-up the routing entry to the peer of this inpcb. If no route
1769 * is found and it cannot be allocated the return NULL. This routine
1770 * is called by TCP routines that access the rmx structure and by tcp_mss
1771 * to get the interface MTU.
1774 tcp_rtlookup(struct in_conninfo *inc)
1776 struct route *ro = &inc->inc_route;
1778 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1779 /* No route yet, so try to acquire one */
1780 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1782 * unused portions of the structure MUST be zero'd
1783 * out because rtalloc() treats it as opaque data
1785 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1786 ro->ro_dst.sa_family = AF_INET;
1787 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1788 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1798 tcp_rtlookup6(struct in_conninfo *inc)
1800 struct route_in6 *ro6 = &inc->inc6_route;
1802 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1803 /* No route yet, so try to acquire one */
1804 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1806 * unused portions of the structure MUST be zero'd
1807 * out because rtalloc() treats it as opaque data
1809 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1810 ro6->ro_dst.sin6_family = AF_INET6;
1811 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1812 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1813 rtalloc((struct route *)ro6);
1816 return (ro6->ro_rt);
1821 /* compute ESP/AH header size for TCP, including outer IP header. */
1823 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1831 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1833 MGETHDR(m, MB_DONTWAIT, MT_DATA);
1838 if (inp->inp_vflag & INP_IPV6) {
1839 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1841 th = (struct tcphdr *)(ip6 + 1);
1842 m->m_pkthdr.len = m->m_len =
1843 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1844 tcp_fillheaders(tp, ip6, th, FALSE);
1845 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1849 ip = mtod(m, struct ip *);
1850 th = (struct tcphdr *)(ip + 1);
1851 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1852 tcp_fillheaders(tp, ip, th, FALSE);
1853 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1862 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1864 * This code attempts to calculate the bandwidth-delay product as a
1865 * means of determining the optimal window size to maximize bandwidth,
1866 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1867 * routers. This code also does a fairly good job keeping RTTs in check
1868 * across slow links like modems. We implement an algorithm which is very
1869 * similar (but not meant to be) TCP/Vegas. The code operates on the
1870 * transmitter side of a TCP connection and so only effects the transmit
1871 * side of the connection.
1873 * BACKGROUND: TCP makes no provision for the management of buffer space
1874 * at the end points or at the intermediate routers and switches. A TCP
1875 * stream, whether using NewReno or not, will eventually buffer as
1876 * many packets as it is able and the only reason this typically works is
1877 * due to the fairly small default buffers made available for a connection
1878 * (typicaly 16K or 32K). As machines use larger windows and/or window
1879 * scaling it is now fairly easy for even a single TCP connection to blow-out
1880 * all available buffer space not only on the local interface, but on
1881 * intermediate routers and switches as well. NewReno makes a misguided
1882 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1883 * then backing off, then steadily increasing the window again until another
1884 * failure occurs, ad-infinitum. This results in terrible oscillation that
1885 * is only made worse as network loads increase and the idea of intentionally
1886 * blowing out network buffers is, frankly, a terrible way to manage network
1889 * It is far better to limit the transmit window prior to the failure
1890 * condition being achieved. There are two general ways to do this: First
1891 * you can 'scan' through different transmit window sizes and locate the
1892 * point where the RTT stops increasing, indicating that you have filled the
1893 * pipe, then scan backwards until you note that RTT stops decreasing, then
1894 * repeat ad-infinitum. This method works in principle but has severe
1895 * implementation issues due to RTT variances, timer granularity, and
1896 * instability in the algorithm which can lead to many false positives and
1897 * create oscillations as well as interact badly with other TCP streams
1898 * implementing the same algorithm.
1900 * The second method is to limit the window to the bandwidth delay product
1901 * of the link. This is the method we implement. RTT variances and our
1902 * own manipulation of the congestion window, bwnd, can potentially
1903 * destabilize the algorithm. For this reason we have to stabilize the
1904 * elements used to calculate the window. We do this by using the minimum
1905 * observed RTT, the long term average of the observed bandwidth, and
1906 * by adding two segments worth of slop. It isn't perfect but it is able
1907 * to react to changing conditions and gives us a very stable basis on
1908 * which to extend the algorithm.
1911 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1919 * If inflight_enable is disabled in the middle of a tcp connection,
1920 * make sure snd_bwnd is effectively disabled.
1922 if (!tcp_inflight_enable) {
1923 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1924 tp->snd_bandwidth = 0;
1929 * Validate the delta time. If a connection is new or has been idle
1930 * a long time we have to reset the bandwidth calculator.
1933 delta_ticks = save_ticks - tp->t_bw_rtttime;
1934 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1935 tp->t_bw_rtttime = ticks;
1936 tp->t_bw_rtseq = ack_seq;
1937 if (tp->snd_bandwidth == 0)
1938 tp->snd_bandwidth = tcp_inflight_min;
1941 if (delta_ticks == 0)
1945 * Sanity check, plus ignore pure window update acks.
1947 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1951 * Figure out the bandwidth. Due to the tick granularity this
1952 * is a very rough number and it MUST be averaged over a fairly
1953 * long period of time. XXX we need to take into account a link
1954 * that is not using all available bandwidth, but for now our
1955 * slop will ramp us up if this case occurs and the bandwidth later
1958 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
1959 tp->t_bw_rtttime = save_ticks;
1960 tp->t_bw_rtseq = ack_seq;
1961 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
1963 tp->snd_bandwidth = bw;
1966 * Calculate the semi-static bandwidth delay product, plus two maximal
1967 * segments. The additional slop puts us squarely in the sweet
1968 * spot and also handles the bandwidth run-up case. Without the
1969 * slop we could be locking ourselves into a lower bandwidth.
1971 * Situations Handled:
1972 * (1) Prevents over-queueing of packets on LANs, especially on
1973 * high speed LANs, allowing larger TCP buffers to be
1974 * specified, and also does a good job preventing
1975 * over-queueing of packets over choke points like modems
1976 * (at least for the transmit side).
1978 * (2) Is able to handle changing network loads (bandwidth
1979 * drops so bwnd drops, bandwidth increases so bwnd
1982 * (3) Theoretically should stabilize in the face of multiple
1983 * connections implementing the same algorithm (this may need
1986 * (4) Stability value (defaults to 20 = 2 maximal packets) can
1987 * be adjusted with a sysctl but typically only needs to be on
1988 * very slow connections. A value no smaller then 5 should
1989 * be used, but only reduce this default if you have no other
1993 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
1994 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
1995 tcp_inflight_stab * (int)tp->t_maxseg / 10;
1998 if (tcp_inflight_debug > 0) {
2000 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
2002 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
2003 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd);
2006 if ((long)bwnd < tcp_inflight_min)
2007 bwnd = tcp_inflight_min;
2008 if (bwnd > tcp_inflight_max)
2009 bwnd = tcp_inflight_max;
2010 if ((long)bwnd < tp->t_maxseg * 2)
2011 bwnd = tp->t_maxseg * 2;
2012 tp->snd_bwnd = bwnd;
2016 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
2019 struct inpcb *inp = tp->t_inpcb;
2021 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
2023 const boolean_t isipv6 = FALSE;
2027 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
2028 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
2029 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
2030 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
2033 rt = tcp_rtlookup6(&inp->inp_inc);
2035 rt = tcp_rtlookup(&inp->inp_inc);
2037 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2038 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2039 *maxsegs = tcp_iw_maxsegs;
2040 *capsegs = tcp_iw_capsegs;
2043 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2044 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2048 tcp_initial_window(struct tcpcb *tp)
2050 if (tcp_do_rfc3390) {
2053 * "If the SYN or SYN/ACK is lost, the initial window
2054 * used by a sender after a correctly transmitted SYN
2055 * MUST be one segment consisting of MSS bytes."
2057 * However, we do something a little bit more aggressive
2058 * then RFC3390 here:
2059 * - Only if time spent in the SYN or SYN|ACK retransmition
2060 * >= 3 seconds, the IW is reduced. We do this mainly
2061 * because when RFC3390 is published, the initial RTO is
2062 * still 3 seconds (the threshold we test here), while
2063 * after RFC6298, the initial RTO is 1 second. This
2064 * behaviour probably still falls within the spirit of
2066 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2067 * Mainly to avoid sender and receiver deadlock until
2068 * delayed ACK timer expires. And even RFC2581 does not
2069 * try to reduce IW upon SYN or SYN|ACK retransmition
2073 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2075 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2076 return (2 * tp->t_maxseg);
2078 u_long maxsegs, capsegs;
2080 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2081 return min(maxsegs * tp->t_maxseg,
2082 max(2 * tp->t_maxseg, capsegs * 1460));
2086 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2088 * Mainly to avoid sender and receiver deadlock
2089 * until delayed ACK timer expires.
2091 return (2 * tp->t_maxseg);
2095 #ifdef TCP_SIGNATURE
2097 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2099 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2100 * When called from tcp_input(), we can be sure that th_sum has been
2101 * zeroed out and verified already.
2103 * Return 0 if successful, otherwise return -1.
2105 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2106 * search with the destination IP address, and a 'magic SPI' to be
2107 * determined by the application. This is hardcoded elsewhere to 1179
2108 * right now. Another branch of this code exists which uses the SPD to
2109 * specify per-application flows but it is unstable.
2112 tcpsignature_compute(
2113 struct mbuf *m, /* mbuf chain */
2114 int len, /* length of TCP data */
2115 int optlen, /* length of TCP options */
2116 u_char *buf, /* storage for MD5 digest */
2117 u_int direction) /* direction of flow */
2119 struct ippseudo ippseudo;
2123 struct ipovly *ipovly;
2124 struct secasvar *sav;
2127 struct ip6_hdr *ip6;
2128 struct in6_addr in6;
2134 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2135 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2137 * Extract the destination from the IP header in the mbuf.
2139 ip = mtod(m, struct ip *);
2141 ip6 = NULL; /* Make the compiler happy. */
2144 * Look up an SADB entry which matches the address found in
2147 switch (IP_VHL_V(ip->ip_vhl)) {
2149 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2150 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2153 case (IPV6_VERSION >> 4):
2154 ip6 = mtod(m, struct ip6_hdr *);
2155 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2156 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2165 kprintf("%s: SADB lookup failed\n", __func__);
2171 * Step 1: Update MD5 hash with IP pseudo-header.
2173 * XXX The ippseudo header MUST be digested in network byte order,
2174 * or else we'll fail the regression test. Assume all fields we've
2175 * been doing arithmetic on have been in host byte order.
2176 * XXX One cannot depend on ipovly->ih_len here. When called from
2177 * tcp_output(), the underlying ip_len member has not yet been set.
2179 switch (IP_VHL_V(ip->ip_vhl)) {
2181 ipovly = (struct ipovly *)ip;
2182 ippseudo.ippseudo_src = ipovly->ih_src;
2183 ippseudo.ippseudo_dst = ipovly->ih_dst;
2184 ippseudo.ippseudo_pad = 0;
2185 ippseudo.ippseudo_p = IPPROTO_TCP;
2186 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2187 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2188 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2189 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2193 * RFC 2385, 2.0 Proposal
2194 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2195 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2196 * extended next header value (to form 32 bits), and 32-bit segment
2198 * Note: Upper-Layer Packet Length comes before Next Header.
2200 case (IPV6_VERSION >> 4):
2202 in6_clearscope(&in6);
2203 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2205 in6_clearscope(&in6);
2206 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2207 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2208 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2210 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2211 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2212 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2214 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2215 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2216 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2225 * Step 2: Update MD5 hash with TCP header, excluding options.
2226 * The TCP checksum must be set to zero.
2228 savecsum = th->th_sum;
2230 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2231 th->th_sum = savecsum;
2233 * Step 3: Update MD5 hash with TCP segment data.
2234 * Use m_apply() to avoid an early m_pullup().
2237 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2239 * Step 4: Update MD5 hash with shared secret.
2241 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2242 MD5Final(buf, &ctx);
2243 key_sa_recordxfer(sav, m);
2249 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2252 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2255 #endif /* TCP_SIGNATURE */