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
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
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15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
36 * The Regents of the University of California. All rights reserved.
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39 * modification, are permitted provided that the following conditions
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63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
67 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $
70 #include "opt_compat.h"
72 #include "opt_inet6.h"
73 #include "opt_ipsec.h"
74 #include "opt_tcpdebug.h"
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/callout.h>
79 #include <sys/kernel.h>
80 #include <sys/sysctl.h>
81 #include <sys/malloc.h>
82 #include <sys/mpipe.h>
85 #include <sys/domain.h>
89 #include <sys/socket.h>
90 #include <sys/socketvar.h>
91 #include <sys/protosw.h>
92 #include <sys/random.h>
93 #include <sys/in_cksum.h>
96 #include <net/route.h>
98 #include <net/netisr.h>
101 #include <netinet/in.h>
102 #include <netinet/in_systm.h>
103 #include <netinet/ip.h>
104 #include <netinet/ip6.h>
105 #include <netinet/in_pcb.h>
106 #include <netinet6/in6_pcb.h>
107 #include <netinet/in_var.h>
108 #include <netinet/ip_var.h>
109 #include <netinet6/ip6_var.h>
110 #include <netinet/ip_icmp.h>
112 #include <netinet/icmp6.h>
114 #include <netinet/tcp.h>
115 #include <netinet/tcp_fsm.h>
116 #include <netinet/tcp_seq.h>
117 #include <netinet/tcp_timer.h>
118 #include <netinet/tcp_timer2.h>
119 #include <netinet/tcp_var.h>
120 #include <netinet6/tcp6_var.h>
121 #include <netinet/tcpip.h>
123 #include <netinet/tcp_debug.h>
125 #include <netinet6/ip6protosw.h>
128 #include <netinet6/ipsec.h>
129 #include <netproto/key/key.h>
131 #include <netinet6/ipsec6.h>
136 #include <netproto/ipsec/ipsec.h>
138 #include <netproto/ipsec/ipsec6.h>
144 #include <machine/smp.h>
146 #include <sys/msgport2.h>
147 #include <sys/mplock2.h>
148 #include <net/netmsg2.h>
150 #if !defined(KTR_TCP)
151 #define KTR_TCP KTR_ALL
154 KTR_INFO_MASTER(tcp);
155 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0);
156 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0);
157 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
158 #define logtcp(name) KTR_LOG(tcp_ ## name)
161 #define TCP_IW_MAXSEGS_DFLT 4
162 #define TCP_IW_CAPSEGS_DFLT 3
164 struct inpcbinfo tcbinfo[MAXCPU];
165 struct tcpcbackqhead tcpcbackq[MAXCPU];
167 static struct lwkt_token tcp_port_token =
168 LWKT_TOKEN_INITIALIZER(tcp_port_token);
170 int tcp_mssdflt = TCP_MSS;
171 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
172 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size");
175 int tcp_v6mssdflt = TCP6_MSS;
176 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW,
177 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6");
181 * Minimum MSS we accept and use. This prevents DoS attacks where
182 * we are forced to a ridiculous low MSS like 20 and send hundreds
183 * of packets instead of one. The effect scales with the available
184 * bandwidth and quickly saturates the CPU and network interface
185 * with packet generation and sending. Set to zero to disable MINMSS
186 * checking. This setting prevents us from sending too small packets.
188 int tcp_minmss = TCP_MINMSS;
189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
190 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
193 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
194 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
195 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time");
198 int tcp_do_rfc1323 = 1;
199 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
200 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
202 static int tcp_tcbhashsize = 0;
203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
204 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable");
206 static int do_tcpdrain = 1;
207 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
208 "Enable tcp_drain routine for extra help when low on mbufs");
210 static int icmp_may_rst = 1;
211 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
212 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
214 static int tcp_isn_reseed_interval = 0;
215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
216 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
219 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on
220 * by default, but with generous values which should allow maximal
221 * bandwidth. In particular, the slop defaults to 50 (5 packets).
223 * The reason for doing this is that the limiter is the only mechanism we
224 * have which seems to do a really good job preventing receiver RX rings
225 * on network interfaces from getting blown out. Even though GigE/10GigE
226 * is supposed to flow control it looks like either it doesn't actually
227 * do it or Open Source drivers do not properly enable it.
229 * People using the limiter to reduce bottlenecks on slower WAN connections
230 * should set the slop to 20 (2 packets).
232 static int tcp_inflight_enable = 1;
233 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
234 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
236 static int tcp_inflight_debug = 0;
237 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
238 &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
240 static int tcp_inflight_min = 6144;
241 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
242 &tcp_inflight_min, 0, "Lower bound for TCP inflight window");
244 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
245 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
246 &tcp_inflight_max, 0, "Upper bound for TCP inflight window");
248 static int tcp_inflight_stab = 50;
249 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
250 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)");
252 static int tcp_do_rfc3390 = 1;
253 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
255 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
257 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
258 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
259 &tcp_iw_maxsegs, 0, "TCP IW segments max");
261 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
262 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
263 &tcp_iw_capsegs, 0, "TCP IW segments");
265 int tcp_low_rtobase = 1;
266 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW,
267 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)");
269 static int tcp_do_ncr = 1;
270 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW,
271 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)");
273 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
274 static struct malloc_pipe tcptemp_mpipe;
276 static void tcp_willblock(void);
277 static void tcp_notify (struct inpcb *, int);
279 struct tcp_stats tcpstats_percpu[MAXCPU];
282 sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
286 for (cpu = 0; cpu < ncpus; ++cpu) {
287 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
288 sizeof(struct tcp_stats))))
290 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
291 sizeof(struct tcp_stats))))
297 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
298 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
300 SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW,
301 &tcpstat, tcp_stats, "TCP statistics");
305 * Target size of TCP PCB hash tables. Must be a power of two.
307 * Note that this can be overridden by the kernel environment
308 * variable net.inet.tcp.tcbhashsize
311 #define TCBHASHSIZE 512
315 * This is the actual shape of what we allocate using the zone
316 * allocator. Doing it this way allows us to protect both structures
317 * using the same generation count, and also eliminates the overhead
318 * of allocating tcpcbs separately. By hiding the structure here,
319 * we avoid changing most of the rest of the code (although it needs
320 * to be changed, eventually, for greater efficiency).
323 #define ALIGNM1 (ALIGNMENT - 1)
327 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
330 struct tcp_callout inp_tp_rexmt;
331 struct tcp_callout inp_tp_persist;
332 struct tcp_callout inp_tp_keep;
333 struct tcp_callout inp_tp_2msl;
334 struct tcp_callout inp_tp_delack;
335 struct netmsg_tcp_timer inp_tp_timermsg;
346 struct inpcbporthead *porthashbase;
347 struct inpcbinfo *ticb;
349 int hashsize = TCBHASHSIZE;
353 * note: tcptemp is used for keepalives, and it is ok for an
354 * allocation to fail so do not specify MPF_INT.
356 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
357 25, -1, 0, NULL, NULL, NULL);
359 tcp_delacktime = TCPTV_DELACK;
360 tcp_keepinit = TCPTV_KEEP_INIT;
361 tcp_keepidle = TCPTV_KEEP_IDLE;
362 tcp_keepintvl = TCPTV_KEEPINTVL;
363 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
365 tcp_rexmit_min = TCPTV_MIN;
366 tcp_rexmit_slop = TCPTV_CPU_VAR;
368 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
369 if (!powerof2(hashsize)) {
370 kprintf("WARNING: TCB hash size not a power of 2\n");
371 hashsize = 512; /* safe default */
373 tcp_tcbhashsize = hashsize;
374 porthashbase = hashinit(hashsize, M_PCB, &porthashmask);
376 for (cpu = 0; cpu < ncpus2; cpu++) {
377 ticb = &tcbinfo[cpu];
378 in_pcbinfo_init(ticb);
380 ticb->hashbase = hashinit(hashsize, M_PCB,
382 ticb->porthashbase = porthashbase;
383 ticb->porthashmask = porthashmask;
384 ticb->porttoken = &tcp_port_token;
386 ticb->porthashbase = hashinit(hashsize, M_PCB,
387 &ticb->porthashmask);
389 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
390 &ticb->wildcardhashmask);
391 ticb->ipi_size = sizeof(struct inp_tp);
392 TAILQ_INIT(&tcpcbackq[cpu]);
395 tcp_reass_maxseg = nmbclusters / 16;
396 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg);
399 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
401 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
403 if (max_protohdr < TCP_MINPROTOHDR)
404 max_protohdr = TCP_MINPROTOHDR;
405 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
407 #undef TCP_MINPROTOHDR
410 * Initialize TCP statistics counters for each CPU.
413 for (cpu = 0; cpu < ncpus; ++cpu) {
414 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
417 bzero(&tcpstat, sizeof(struct tcp_stats));
421 netisr_register_rollup(tcp_willblock);
428 int cpu = mycpu->gd_cpuid;
430 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) {
431 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
432 tp->t_flags &= ~TF_ONOUTPUTQ;
433 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq);
439 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
440 * tcp_template used to store this data in mbufs, but we now recopy it out
441 * of the tcpcb each time to conserve mbufs.
444 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr)
446 struct inpcb *inp = tp->t_inpcb;
447 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
450 if (inp->inp_vflag & INP_IPV6) {
453 ip6 = (struct ip6_hdr *)ip_ptr;
454 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
455 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
456 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
457 (IPV6_VERSION & IPV6_VERSION_MASK);
458 ip6->ip6_nxt = IPPROTO_TCP;
459 ip6->ip6_plen = sizeof(struct tcphdr);
460 ip6->ip6_src = inp->in6p_laddr;
461 ip6->ip6_dst = inp->in6p_faddr;
466 struct ip *ip = (struct ip *) ip_ptr;
468 ip->ip_vhl = IP_VHL_BORING;
475 ip->ip_p = IPPROTO_TCP;
476 ip->ip_src = inp->inp_laddr;
477 ip->ip_dst = inp->inp_faddr;
478 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
480 htons(sizeof(struct tcphdr) + IPPROTO_TCP));
483 tcp_hdr->th_sport = inp->inp_lport;
484 tcp_hdr->th_dport = inp->inp_fport;
489 tcp_hdr->th_flags = 0;
495 * Create template to be used to send tcp packets on a connection.
496 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
497 * use for this function is in keepalives, which use tcp_respond.
500 tcp_maketemplate(struct tcpcb *tp)
504 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
506 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t);
511 tcp_freetemplate(struct tcptemp *tmp)
513 mpipe_free(&tcptemp_mpipe, tmp);
517 * Send a single message to the TCP at address specified by
518 * the given TCP/IP header. If m == NULL, then we make a copy
519 * of the tcpiphdr at ti and send directly to the addressed host.
520 * This is used to force keep alive messages out using the TCP
521 * template for a connection. If flags are given then we send
522 * a message back to the TCP which originated the * segment ti,
523 * and discard the mbuf containing it and any other attached mbufs.
525 * In any case the ack and sequence number of the transmitted
526 * segment are as specified by the parameters.
528 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
531 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
532 tcp_seq ack, tcp_seq seq, int flags)
536 struct route *ro = NULL;
538 struct ip *ip = ipgen;
541 struct route_in6 *ro6 = NULL;
542 struct route_in6 sro6;
543 struct ip6_hdr *ip6 = ipgen;
544 boolean_t use_tmpro = TRUE;
546 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
548 const boolean_t isipv6 = FALSE;
552 if (!(flags & TH_RST)) {
553 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv);
556 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
557 win = (long)TCP_MAXWIN << tp->rcv_scale;
560 * Don't use the route cache of a listen socket,
561 * it is not MPSAFE; use temporary route cache.
563 if (tp->t_state != TCPS_LISTEN) {
565 ro6 = &tp->t_inpcb->in6p_route;
567 ro = &tp->t_inpcb->inp_route;
574 bzero(ro6, sizeof *ro6);
577 bzero(ro, sizeof *ro);
581 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
585 m->m_data += max_linkhdr;
587 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
588 ip6 = mtod(m, struct ip6_hdr *);
589 nth = (struct tcphdr *)(ip6 + 1);
591 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
592 ip = mtod(m, struct ip *);
593 nth = (struct tcphdr *)(ip + 1);
595 bcopy(th, nth, sizeof(struct tcphdr));
600 m->m_data = (caddr_t)ipgen;
601 /* m_len is set later */
603 #define xchg(a, b, type) { type t; t = a; a = b; b = t; }
605 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
606 nth = (struct tcphdr *)(ip6 + 1);
608 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
609 nth = (struct tcphdr *)(ip + 1);
613 * this is usually a case when an extension header
614 * exists between the IPv6 header and the
617 nth->th_sport = th->th_sport;
618 nth->th_dport = th->th_dport;
620 xchg(nth->th_dport, nth->th_sport, n_short);
625 ip6->ip6_vfc = IPV6_VERSION;
626 ip6->ip6_nxt = IPPROTO_TCP;
627 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
628 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
630 tlen += sizeof(struct tcpiphdr);
632 ip->ip_ttl = ip_defttl;
635 m->m_pkthdr.len = tlen;
636 m->m_pkthdr.rcvif = NULL;
637 nth->th_seq = htonl(seq);
638 nth->th_ack = htonl(ack);
640 nth->th_off = sizeof(struct tcphdr) >> 2;
641 nth->th_flags = flags;
643 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
645 nth->th_win = htons((u_short)win);
649 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
650 sizeof(struct ip6_hdr),
651 tlen - sizeof(struct ip6_hdr));
652 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
653 (ro6 && ro6->ro_rt) ?
654 ro6->ro_rt->rt_ifp : NULL);
656 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
657 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
658 m->m_pkthdr.csum_flags = CSUM_TCP;
659 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
662 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
663 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
666 ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
667 tp ? tp->t_inpcb : NULL);
668 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
673 ipflags |= IP_DEBUGROUTE;
674 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
675 if ((ro == &sro) && (ro->ro_rt != NULL)) {
683 * Create a new TCP control block, making an
684 * empty reassembly queue and hooking it to the argument
685 * protocol control block. The `inp' parameter must have
686 * come from the zone allocator set up in tcp_init().
689 tcp_newtcpcb(struct inpcb *inp)
694 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
696 const boolean_t isipv6 = FALSE;
699 it = (struct inp_tp *)inp;
701 bzero(tp, sizeof(struct tcpcb));
702 TAILQ_INIT(&tp->t_segq);
703 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
704 tp->t_rxtthresh = tcprexmtthresh;
706 /* Set up our timeouts. */
707 tp->tt_rexmt = &it->inp_tp_rexmt;
708 tp->tt_persist = &it->inp_tp_persist;
709 tp->tt_keep = &it->inp_tp_keep;
710 tp->tt_2msl = &it->inp_tp_2msl;
711 tp->tt_delack = &it->inp_tp_delack;
715 * Zero out timer message. We don't create it here,
716 * since the current CPU may not be the owner of this
719 tp->tt_msg = &it->inp_tp_timermsg;
720 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
722 tp->t_keepinit = tcp_keepinit;
723 tp->t_keepidle = tcp_keepidle;
724 tp->t_keepintvl = tcp_keepintvl;
725 tp->t_keepcnt = tcp_keepcnt;
726 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
729 tp->t_flags |= TF_NCR;
731 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP);
733 tp->t_inpcb = inp; /* XXX */
734 tp->t_state = TCPS_CLOSED;
736 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
737 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
738 * reasonable initial retransmit time.
740 tp->t_srtt = TCPTV_SRTTBASE;
742 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
743 tp->t_rttmin = tcp_rexmit_min;
744 tp->t_rxtcur = TCPTV_RTOBASE;
745 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
746 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
747 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
748 tp->snd_last = ticks;
749 tp->t_rcvtime = ticks;
751 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
752 * because the socket may be bound to an IPv6 wildcard address,
753 * which may match an IPv4-mapped IPv6 address.
755 inp->inp_ip_ttl = ip_defttl;
757 tcp_sack_tcpcb_init(tp);
758 return (tp); /* XXX */
762 * Drop a TCP connection, reporting the specified error.
763 * If connection is synchronized, then send a RST to peer.
766 tcp_drop(struct tcpcb *tp, int error)
768 struct socket *so = tp->t_inpcb->inp_socket;
770 if (TCPS_HAVERCVDSYN(tp->t_state)) {
771 tp->t_state = TCPS_CLOSED;
773 tcpstat.tcps_drops++;
775 tcpstat.tcps_conndrops++;
776 if (error == ETIMEDOUT && tp->t_softerror)
777 error = tp->t_softerror;
778 so->so_error = error;
779 return (tcp_close(tp));
784 struct netmsg_listen_detach {
785 struct netmsg_base base;
790 tcp_listen_detach_handler(netmsg_t msg)
792 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
793 struct tcpcb *tp = nmsg->nm_tp;
794 int cpu = mycpuid, nextcpu;
796 if (tp->t_flags & TF_LISTEN)
797 syncache_destroy(tp);
799 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
802 if (nextcpu < ncpus2)
803 lwkt_forwardmsg(cpu_portfn(nextcpu), &nmsg->base.lmsg);
805 lwkt_replymsg(&nmsg->base.lmsg, 0);
811 * Close a TCP control block:
812 * discard all space held by the tcp
813 * discard internet protocol block
814 * wake up any sleepers
817 tcp_close(struct tcpcb *tp)
820 struct inpcb *inp = tp->t_inpcb;
821 struct socket *so = inp->inp_socket;
823 boolean_t dosavessthresh;
825 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
826 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
828 const boolean_t isipv6 = FALSE;
833 * INP_WILDCARD_MP indicates that listen(2) has been called on
834 * this socket. This implies:
835 * - A wildcard inp's hash is replicated for each protocol thread.
836 * - Syncache for this inp grows independently in each protocol
838 * - There is more than one cpu
840 * We have to chain a message to the rest of the protocol threads
841 * to cleanup the wildcard hash and the syncache. The cleanup
842 * in the current protocol thread is defered till the end of this
846 * After cleanup the inp's hash and syncache entries, this inp will
847 * no longer be available to the rest of the protocol threads, so we
848 * are safe to whack the inp in the following code.
850 if (inp->inp_flags & INP_WILDCARD_MP) {
851 struct netmsg_listen_detach nmsg;
853 KKASSERT(so->so_port == cpu_portfn(0));
854 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
855 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
857 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
858 MSGF_PRIORITY, tcp_listen_detach_handler);
860 lwkt_domsg(cpu_portfn(1), &nmsg.base.lmsg, 0);
862 inp->inp_flags &= ~INP_WILDCARD_MP;
866 KKASSERT(tp->t_state != TCPS_TERMINATING);
867 tp->t_state = TCPS_TERMINATING;
870 * Make sure that all of our timers are stopped before we
871 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
872 * timers are never used. If timer message is never created
873 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
875 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
876 tcp_callout_stop(tp, tp->tt_rexmt);
877 tcp_callout_stop(tp, tp->tt_persist);
878 tcp_callout_stop(tp, tp->tt_keep);
879 tcp_callout_stop(tp, tp->tt_2msl);
880 tcp_callout_stop(tp, tp->tt_delack);
883 if (tp->t_flags & TF_ONOUTPUTQ) {
884 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
885 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
886 tp->t_flags &= ~TF_ONOUTPUTQ;
890 * If we got enough samples through the srtt filter,
891 * save the rtt and rttvar in the routing entry.
892 * 'Enough' is arbitrarily defined as the 16 samples.
893 * 16 samples is enough for the srtt filter to converge
894 * to within 5% of the correct value; fewer samples and
895 * we could save a very bogus rtt.
897 * Don't update the default route's characteristics and don't
898 * update anything that the user "locked".
900 if (tp->t_rttupdated >= 16) {
904 struct sockaddr_in6 *sin6;
906 if ((rt = inp->in6p_route.ro_rt) == NULL)
908 sin6 = (struct sockaddr_in6 *)rt_key(rt);
909 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
912 if ((rt = inp->inp_route.ro_rt) == NULL ||
913 ((struct sockaddr_in *)rt_key(rt))->
914 sin_addr.s_addr == INADDR_ANY)
917 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
918 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
919 if (rt->rt_rmx.rmx_rtt && i)
921 * filter this update to half the old & half
922 * the new values, converting scale.
923 * See route.h and tcp_var.h for a
924 * description of the scaling constants.
927 (rt->rt_rmx.rmx_rtt + i) / 2;
929 rt->rt_rmx.rmx_rtt = i;
930 tcpstat.tcps_cachedrtt++;
932 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
934 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
935 if (rt->rt_rmx.rmx_rttvar && i)
936 rt->rt_rmx.rmx_rttvar =
937 (rt->rt_rmx.rmx_rttvar + i) / 2;
939 rt->rt_rmx.rmx_rttvar = i;
940 tcpstat.tcps_cachedrttvar++;
943 * The old comment here said:
944 * update the pipelimit (ssthresh) if it has been updated
945 * already or if a pipesize was specified & the threshhold
946 * got below half the pipesize. I.e., wait for bad news
947 * before we start updating, then update on both good
950 * But we want to save the ssthresh even if no pipesize is
951 * specified explicitly in the route, because such
952 * connections still have an implicit pipesize specified
953 * by the global tcp_sendspace. In the absence of a reliable
954 * way to calculate the pipesize, it will have to do.
956 i = tp->snd_ssthresh;
957 if (rt->rt_rmx.rmx_sendpipe != 0)
958 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
960 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
961 if (dosavessthresh ||
962 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
963 (rt->rt_rmx.rmx_ssthresh != 0))) {
965 * convert the limit from user data bytes to
966 * packets then to packet data bytes.
968 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
973 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
974 sizeof(struct tcpiphdr));
975 if (rt->rt_rmx.rmx_ssthresh)
976 rt->rt_rmx.rmx_ssthresh =
977 (rt->rt_rmx.rmx_ssthresh + i) / 2;
979 rt->rt_rmx.rmx_ssthresh = i;
980 tcpstat.tcps_cachedssthresh++;
985 /* free the reassembly queue, if any */
986 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) {
987 TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
990 atomic_add_int(&tcp_reass_qsize, -1);
992 /* throw away SACK blocks in scoreboard*/
994 tcp_sack_destroy(&tp->scb);
996 inp->inp_ppcb = NULL;
997 soisdisconnected(so);
998 /* note: pcb detached later on */
1000 tcp_destroy_timermsg(tp);
1002 if (tp->t_flags & TF_LISTEN)
1003 syncache_destroy(tp);
1007 * pcbdetach removes any wildcard hash entry on the current CPU.
1016 tcpstat.tcps_closed++;
1020 static __inline void
1021 tcp_drain_oncpu(struct inpcbhead *head)
1023 struct inpcb *marker;
1026 struct tseg_qent *te;
1029 * Allows us to block while running the list
1031 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1032 marker->inp_flags |= INP_PLACEMARKER;
1033 LIST_INSERT_HEAD(head, marker, inp_list);
1035 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) {
1036 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1037 (tcpb = intotcpcb(inpb)) != NULL &&
1038 (te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) {
1039 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q);
1042 atomic_add_int(&tcp_reass_qsize, -1);
1045 LIST_REMOVE(marker, inp_list);
1046 LIST_INSERT_AFTER(inpb, marker, inp_list);
1049 LIST_REMOVE(marker, inp_list);
1050 kfree(marker, M_TEMP);
1054 struct netmsg_tcp_drain {
1055 struct netmsg_base base;
1056 struct inpcbhead *nm_head;
1060 tcp_drain_handler(netmsg_t msg)
1062 struct netmsg_tcp_drain *nm = (void *)msg;
1064 tcp_drain_oncpu(nm->nm_head);
1065 lwkt_replymsg(&nm->base.lmsg, 0);
1080 * Walk the tcpbs, if existing, and flush the reassembly queue,
1081 * if there is one...
1082 * XXX: The "Net/3" implementation doesn't imply that the TCP
1083 * reassembly queue should be flushed, but in a situation
1084 * where we're really low on mbufs, this is potentially
1088 for (cpu = 0; cpu < ncpus2; cpu++) {
1089 struct netmsg_tcp_drain *nm;
1091 if (cpu == mycpu->gd_cpuid) {
1092 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead);
1094 nm = kmalloc(sizeof(struct netmsg_tcp_drain),
1095 M_LWKTMSG, M_NOWAIT);
1098 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1099 0, tcp_drain_handler);
1100 nm->nm_head = &tcbinfo[cpu].pcblisthead;
1101 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg);
1105 tcp_drain_oncpu(&tcbinfo[0].pcblisthead);
1110 * Notify a tcp user of an asynchronous error;
1111 * store error as soft error, but wake up user
1112 * (for now, won't do anything until can select for soft error).
1114 * Do not wake up user since there currently is no mechanism for
1115 * reporting soft errors (yet - a kqueue filter may be added).
1118 tcp_notify(struct inpcb *inp, int error)
1120 struct tcpcb *tp = intotcpcb(inp);
1123 * Ignore some errors if we are hooked up.
1124 * If connection hasn't completed, has retransmitted several times,
1125 * and receives a second error, give up now. This is better
1126 * than waiting a long time to establish a connection that
1127 * can never complete.
1129 if (tp->t_state == TCPS_ESTABLISHED &&
1130 (error == EHOSTUNREACH || error == ENETUNREACH ||
1131 error == EHOSTDOWN)) {
1133 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1135 tcp_drop(tp, error);
1137 tp->t_softerror = error;
1139 wakeup(&so->so_timeo);
1146 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1149 struct inpcb *marker;
1158 * The process of preparing the TCB list is too time-consuming and
1159 * resource-intensive to repeat twice on every request.
1161 if (req->oldptr == NULL) {
1162 for (ccpu = 0; ccpu < ncpus; ++ccpu) {
1163 gd = globaldata_find(ccpu);
1164 n += tcbinfo[gd->gd_cpuid].ipi_count;
1166 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1170 if (req->newptr != NULL)
1173 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1174 marker->inp_flags |= INP_PLACEMARKER;
1177 * OK, now we're committed to doing something. Run the inpcb list
1178 * for each cpu in the system and construct the output. Use a
1179 * list placemarker to deal with list changes occuring during
1180 * copyout blockages (but otherwise depend on being on the correct
1181 * cpu to avoid races).
1183 origcpu = mycpu->gd_cpuid;
1184 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) {
1190 cpu_id = (origcpu + ccpu) % ncpus;
1191 if ((smp_active_mask & CPUMASK(cpu_id)) == 0)
1193 rgd = globaldata_find(cpu_id);
1194 lwkt_setcpu_self(rgd);
1196 n = tcbinfo[cpu_id].ipi_count;
1198 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list);
1200 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1202 * process a snapshot of pcbs, ignoring placemarkers
1203 * and using our own to allow SYSCTL_OUT to block.
1205 LIST_REMOVE(marker, inp_list);
1206 LIST_INSERT_AFTER(inp, marker, inp_list);
1208 if (inp->inp_flags & INP_PLACEMARKER)
1210 if (prison_xinpcb(req->td, inp))
1213 xt.xt_len = sizeof xt;
1214 bcopy(inp, &xt.xt_inp, sizeof *inp);
1215 inp_ppcb = inp->inp_ppcb;
1216 if (inp_ppcb != NULL)
1217 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1219 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1220 if (inp->inp_socket)
1221 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1222 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1226 LIST_REMOVE(marker, inp_list);
1227 if (error == 0 && i < n) {
1228 bzero(&xt, sizeof xt);
1229 xt.xt_len = sizeof xt;
1231 error = SYSCTL_OUT(req, &xt, sizeof xt);
1240 * Make sure we are on the same cpu we were on originally, since
1241 * higher level callers expect this. Also don't pollute caches with
1242 * migrated userland data by (eventually) returning to userland
1243 * on a different cpu.
1245 lwkt_setcpu_self(globaldata_find(origcpu));
1246 kfree(marker, M_TEMP);
1250 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1251 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1254 tcp_getcred(SYSCTL_HANDLER_ARGS)
1256 struct sockaddr_in addrs[2];
1261 error = priv_check(req->td, PRIV_ROOT);
1264 error = SYSCTL_IN(req, addrs, sizeof addrs);
1268 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1269 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1270 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1271 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1272 if (inp == NULL || inp->inp_socket == NULL) {
1276 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1282 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1283 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1287 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1289 struct sockaddr_in6 addrs[2];
1292 boolean_t mapped = FALSE;
1294 error = priv_check(req->td, PRIV_ROOT);
1297 error = SYSCTL_IN(req, addrs, sizeof addrs);
1300 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1301 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1308 inp = in_pcblookup_hash(&tcbinfo[0],
1309 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1311 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1315 inp = in6_pcblookup_hash(&tcbinfo[0],
1316 &addrs[1].sin6_addr, addrs[1].sin6_port,
1317 &addrs[0].sin6_addr, addrs[0].sin6_port,
1320 if (inp == NULL || inp->inp_socket == NULL) {
1324 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1330 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1332 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1335 struct netmsg_tcp_notify {
1336 struct netmsg_base base;
1337 void (*nm_notify)(struct inpcb *, int);
1338 struct in_addr nm_faddr;
1343 tcp_notifyall_oncpu(netmsg_t msg)
1345 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1348 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr,
1349 nm->nm_arg, nm->nm_notify);
1351 nextcpu = mycpuid + 1;
1352 if (nextcpu < ncpus2)
1353 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
1355 lwkt_replymsg(&nm->base.lmsg, 0);
1359 tcp_ctlinput(netmsg_t msg)
1361 int cmd = msg->ctlinput.nm_cmd;
1362 struct sockaddr *sa = msg->ctlinput.nm_arg;
1363 struct ip *ip = msg->ctlinput.nm_extra;
1365 struct in_addr faddr;
1368 void (*notify)(struct inpcb *, int) = tcp_notify;
1372 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1376 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1377 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1380 arg = inetctlerrmap[cmd];
1381 if (cmd == PRC_QUENCH) {
1382 notify = tcp_quench;
1383 } else if (icmp_may_rst &&
1384 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1385 cmd == PRC_UNREACH_PORT ||
1386 cmd == PRC_TIMXCEED_INTRANS) &&
1388 notify = tcp_drop_syn_sent;
1389 } else if (cmd == PRC_MSGSIZE) {
1390 struct icmp *icmp = (struct icmp *)
1391 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1393 arg = ntohs(icmp->icmp_nextmtu);
1394 notify = tcp_mtudisc;
1395 } else if (PRC_IS_REDIRECT(cmd)) {
1397 notify = in_rtchange;
1398 } else if (cmd == PRC_HOSTDEAD) {
1404 th = (struct tcphdr *)((caddr_t)ip +
1405 (IP_VHL_HL(ip->ip_vhl) << 2));
1406 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
1407 ip->ip_src.s_addr, th->th_sport);
1408 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
1409 ip->ip_src, th->th_sport, 0, NULL);
1410 if ((inp != NULL) && (inp->inp_socket != NULL)) {
1411 icmpseq = htonl(th->th_seq);
1412 tp = intotcpcb(inp);
1413 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1414 SEQ_LT(icmpseq, tp->snd_max))
1415 (*notify)(inp, arg);
1417 struct in_conninfo inc;
1419 inc.inc_fport = th->th_dport;
1420 inc.inc_lport = th->th_sport;
1421 inc.inc_faddr = faddr;
1422 inc.inc_laddr = ip->ip_src;
1426 syncache_unreach(&inc, th);
1430 struct netmsg_tcp_notify *nm;
1432 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
1433 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1434 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1435 0, tcp_notifyall_oncpu);
1436 nm->nm_faddr = faddr;
1438 nm->nm_notify = notify;
1440 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg);
1443 lwkt_replymsg(&msg->lmsg, 0);
1449 tcp6_ctlinput(netmsg_t msg)
1451 int cmd = msg->ctlinput.nm_cmd;
1452 struct sockaddr *sa = msg->ctlinput.nm_arg;
1453 void *d = msg->ctlinput.nm_extra;
1455 void (*notify) (struct inpcb *, int) = tcp_notify;
1456 struct ip6_hdr *ip6;
1458 struct ip6ctlparam *ip6cp = NULL;
1459 const struct sockaddr_in6 *sa6_src = NULL;
1461 struct tcp_portonly {
1467 if (sa->sa_family != AF_INET6 ||
1468 sa->sa_len != sizeof(struct sockaddr_in6)) {
1473 if (cmd == PRC_QUENCH)
1474 notify = tcp_quench;
1475 else if (cmd == PRC_MSGSIZE) {
1476 struct ip6ctlparam *ip6cp = d;
1477 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1479 arg = ntohl(icmp6->icmp6_mtu);
1480 notify = tcp_mtudisc;
1481 } else if (!PRC_IS_REDIRECT(cmd) &&
1482 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1486 /* if the parameter is from icmp6, decode it. */
1488 ip6cp = (struct ip6ctlparam *)d;
1490 ip6 = ip6cp->ip6c_ip6;
1491 off = ip6cp->ip6c_off;
1492 sa6_src = ip6cp->ip6c_src;
1496 off = 0; /* fool gcc */
1501 struct in_conninfo inc;
1503 * XXX: We assume that when IPV6 is non NULL,
1504 * M and OFF are valid.
1507 /* check if we can safely examine src and dst ports */
1508 if (m->m_pkthdr.len < off + sizeof *thp)
1511 bzero(&th, sizeof th);
1512 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
1514 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport,
1515 (struct sockaddr *)ip6cp->ip6c_src,
1516 th.th_sport, cmd, arg, notify);
1518 inc.inc_fport = th.th_dport;
1519 inc.inc_lport = th.th_sport;
1520 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1521 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1523 syncache_unreach(&inc, &th);
1525 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0,
1526 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1529 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1535 * Following is where TCP initial sequence number generation occurs.
1537 * There are two places where we must use initial sequence numbers:
1538 * 1. In SYN-ACK packets.
1539 * 2. In SYN packets.
1541 * All ISNs for SYN-ACK packets are generated by the syncache. See
1542 * tcp_syncache.c for details.
1544 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1545 * depends on this property. In addition, these ISNs should be
1546 * unguessable so as to prevent connection hijacking. To satisfy
1547 * the requirements of this situation, the algorithm outlined in
1548 * RFC 1948 is used to generate sequence numbers.
1550 * Implementation details:
1552 * Time is based off the system timer, and is corrected so that it
1553 * increases by one megabyte per second. This allows for proper
1554 * recycling on high speed LANs while still leaving over an hour
1557 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1558 * between seeding of isn_secret. This is normally set to zero,
1559 * as reseeding should not be necessary.
1563 #define ISN_BYTES_PER_SECOND 1048576
1565 u_char isn_secret[32];
1566 int isn_last_reseed;
1570 tcp_new_isn(struct tcpcb *tp)
1572 u_int32_t md5_buffer[4];
1575 /* Seed if this is the first use, reseed if requested. */
1576 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1577 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1579 read_random_unlimited(&isn_secret, sizeof isn_secret);
1580 isn_last_reseed = ticks;
1583 /* Compute the md5 hash and return the ISN. */
1585 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1586 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
1588 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
1589 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1590 sizeof(struct in6_addr));
1591 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1592 sizeof(struct in6_addr));
1596 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1597 sizeof(struct in_addr));
1598 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1599 sizeof(struct in_addr));
1601 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1602 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1603 new_isn = (tcp_seq) md5_buffer[0];
1604 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
1609 * When a source quench is received, close congestion window
1610 * to one segment. We will gradually open it again as we proceed.
1613 tcp_quench(struct inpcb *inp, int error)
1615 struct tcpcb *tp = intotcpcb(inp);
1618 tp->snd_cwnd = tp->t_maxseg;
1624 * When a specific ICMP unreachable message is received and the
1625 * connection state is SYN-SENT, drop the connection. This behavior
1626 * is controlled by the icmp_may_rst sysctl.
1629 tcp_drop_syn_sent(struct inpcb *inp, int error)
1631 struct tcpcb *tp = intotcpcb(inp);
1633 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
1634 tcp_drop(tp, error);
1638 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1639 * based on the new value in the route. Also nudge TCP to send something,
1640 * since we know the packet we just sent was dropped.
1641 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1644 tcp_mtudisc(struct inpcb *inp, int mtu)
1646 struct tcpcb *tp = intotcpcb(inp);
1648 struct socket *so = inp->inp_socket;
1651 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1653 const boolean_t isipv6 = FALSE;
1660 * If no MTU is provided in the ICMP message, use the
1661 * next lower likely value, as specified in RFC 1191.
1666 oldmtu = tp->t_maxopd +
1668 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1669 sizeof(struct tcpiphdr));
1670 mtu = ip_next_mtu(oldmtu, 0);
1674 rt = tcp_rtlookup6(&inp->inp_inc);
1676 rt = tcp_rtlookup(&inp->inp_inc);
1678 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1679 mtu = rt->rt_rmx.rmx_mtu;
1683 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1684 sizeof(struct tcpiphdr));
1687 * XXX - The following conditional probably violates the TCP
1688 * spec. The problem is that, since we don't know the
1689 * other end's MSS, we are supposed to use a conservative
1690 * default. But, if we do that, then MTU discovery will
1691 * never actually take place, because the conservative
1692 * default is much less than the MTUs typically seen
1693 * on the Internet today. For the moment, we'll sweep
1694 * this under the carpet.
1696 * The conservative default might not actually be a problem
1697 * if the only case this occurs is when sending an initial
1698 * SYN with options and data to a host we've never talked
1699 * to before. Then, they will reply with an MSS value which
1700 * will get recorded and the new parameters should get
1701 * recomputed. For Further Study.
1703 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1704 maxopd = rt->rt_rmx.rmx_mssopt;
1708 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1709 sizeof(struct tcpiphdr));
1711 if (tp->t_maxopd <= maxopd)
1713 tp->t_maxopd = maxopd;
1716 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1717 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1718 mss -= TCPOLEN_TSTAMP_APPA;
1720 /* round down to multiple of MCLBYTES */
1721 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1723 mss &= ~(MCLBYTES - 1);
1726 mss = (mss / MCLBYTES) * MCLBYTES;
1729 if (so->so_snd.ssb_hiwat < mss)
1730 mss = so->so_snd.ssb_hiwat;
1734 tp->snd_nxt = tp->snd_una;
1736 tcpstat.tcps_mturesent++;
1740 * Look-up the routing entry to the peer of this inpcb. If no route
1741 * is found and it cannot be allocated the return NULL. This routine
1742 * is called by TCP routines that access the rmx structure and by tcp_mss
1743 * to get the interface MTU.
1746 tcp_rtlookup(struct in_conninfo *inc)
1748 struct route *ro = &inc->inc_route;
1750 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1751 /* No route yet, so try to acquire one */
1752 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1754 * unused portions of the structure MUST be zero'd
1755 * out because rtalloc() treats it as opaque data
1757 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1758 ro->ro_dst.sa_family = AF_INET;
1759 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1760 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1770 tcp_rtlookup6(struct in_conninfo *inc)
1772 struct route_in6 *ro6 = &inc->inc6_route;
1774 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1775 /* No route yet, so try to acquire one */
1776 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1778 * unused portions of the structure MUST be zero'd
1779 * out because rtalloc() treats it as opaque data
1781 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1782 ro6->ro_dst.sin6_family = AF_INET6;
1783 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1784 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1785 rtalloc((struct route *)ro6);
1788 return (ro6->ro_rt);
1793 /* compute ESP/AH header size for TCP, including outer IP header. */
1795 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1803 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1805 MGETHDR(m, MB_DONTWAIT, MT_DATA);
1810 if (inp->inp_vflag & INP_IPV6) {
1811 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1813 th = (struct tcphdr *)(ip6 + 1);
1814 m->m_pkthdr.len = m->m_len =
1815 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1816 tcp_fillheaders(tp, ip6, th);
1817 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1821 ip = mtod(m, struct ip *);
1822 th = (struct tcphdr *)(ip + 1);
1823 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1824 tcp_fillheaders(tp, ip, th);
1825 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1834 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1836 * This code attempts to calculate the bandwidth-delay product as a
1837 * means of determining the optimal window size to maximize bandwidth,
1838 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1839 * routers. This code also does a fairly good job keeping RTTs in check
1840 * across slow links like modems. We implement an algorithm which is very
1841 * similar (but not meant to be) TCP/Vegas. The code operates on the
1842 * transmitter side of a TCP connection and so only effects the transmit
1843 * side of the connection.
1845 * BACKGROUND: TCP makes no provision for the management of buffer space
1846 * at the end points or at the intermediate routers and switches. A TCP
1847 * stream, whether using NewReno or not, will eventually buffer as
1848 * many packets as it is able and the only reason this typically works is
1849 * due to the fairly small default buffers made available for a connection
1850 * (typicaly 16K or 32K). As machines use larger windows and/or window
1851 * scaling it is now fairly easy for even a single TCP connection to blow-out
1852 * all available buffer space not only on the local interface, but on
1853 * intermediate routers and switches as well. NewReno makes a misguided
1854 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1855 * then backing off, then steadily increasing the window again until another
1856 * failure occurs, ad-infinitum. This results in terrible oscillation that
1857 * is only made worse as network loads increase and the idea of intentionally
1858 * blowing out network buffers is, frankly, a terrible way to manage network
1861 * It is far better to limit the transmit window prior to the failure
1862 * condition being achieved. There are two general ways to do this: First
1863 * you can 'scan' through different transmit window sizes and locate the
1864 * point where the RTT stops increasing, indicating that you have filled the
1865 * pipe, then scan backwards until you note that RTT stops decreasing, then
1866 * repeat ad-infinitum. This method works in principle but has severe
1867 * implementation issues due to RTT variances, timer granularity, and
1868 * instability in the algorithm which can lead to many false positives and
1869 * create oscillations as well as interact badly with other TCP streams
1870 * implementing the same algorithm.
1872 * The second method is to limit the window to the bandwidth delay product
1873 * of the link. This is the method we implement. RTT variances and our
1874 * own manipulation of the congestion window, bwnd, can potentially
1875 * destabilize the algorithm. For this reason we have to stabilize the
1876 * elements used to calculate the window. We do this by using the minimum
1877 * observed RTT, the long term average of the observed bandwidth, and
1878 * by adding two segments worth of slop. It isn't perfect but it is able
1879 * to react to changing conditions and gives us a very stable basis on
1880 * which to extend the algorithm.
1883 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1891 * If inflight_enable is disabled in the middle of a tcp connection,
1892 * make sure snd_bwnd is effectively disabled.
1894 if (!tcp_inflight_enable) {
1895 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1896 tp->snd_bandwidth = 0;
1901 * Validate the delta time. If a connection is new or has been idle
1902 * a long time we have to reset the bandwidth calculator.
1905 delta_ticks = save_ticks - tp->t_bw_rtttime;
1906 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1907 tp->t_bw_rtttime = ticks;
1908 tp->t_bw_rtseq = ack_seq;
1909 if (tp->snd_bandwidth == 0)
1910 tp->snd_bandwidth = tcp_inflight_min;
1913 if (delta_ticks == 0)
1917 * Sanity check, plus ignore pure window update acks.
1919 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1923 * Figure out the bandwidth. Due to the tick granularity this
1924 * is a very rough number and it MUST be averaged over a fairly
1925 * long period of time. XXX we need to take into account a link
1926 * that is not using all available bandwidth, but for now our
1927 * slop will ramp us up if this case occurs and the bandwidth later
1930 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
1931 tp->t_bw_rtttime = save_ticks;
1932 tp->t_bw_rtseq = ack_seq;
1933 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
1935 tp->snd_bandwidth = bw;
1938 * Calculate the semi-static bandwidth delay product, plus two maximal
1939 * segments. The additional slop puts us squarely in the sweet
1940 * spot and also handles the bandwidth run-up case. Without the
1941 * slop we could be locking ourselves into a lower bandwidth.
1943 * Situations Handled:
1944 * (1) Prevents over-queueing of packets on LANs, especially on
1945 * high speed LANs, allowing larger TCP buffers to be
1946 * specified, and also does a good job preventing
1947 * over-queueing of packets over choke points like modems
1948 * (at least for the transmit side).
1950 * (2) Is able to handle changing network loads (bandwidth
1951 * drops so bwnd drops, bandwidth increases so bwnd
1954 * (3) Theoretically should stabilize in the face of multiple
1955 * connections implementing the same algorithm (this may need
1958 * (4) Stability value (defaults to 20 = 2 maximal packets) can
1959 * be adjusted with a sysctl but typically only needs to be on
1960 * very slow connections. A value no smaller then 5 should
1961 * be used, but only reduce this default if you have no other
1965 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
1966 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
1967 tcp_inflight_stab * (int)tp->t_maxseg / 10;
1970 if (tcp_inflight_debug > 0) {
1972 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
1974 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
1975 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd);
1978 if ((long)bwnd < tcp_inflight_min)
1979 bwnd = tcp_inflight_min;
1980 if (bwnd > tcp_inflight_max)
1981 bwnd = tcp_inflight_max;
1982 if ((long)bwnd < tp->t_maxseg * 2)
1983 bwnd = tp->t_maxseg * 2;
1984 tp->snd_bwnd = bwnd;
1988 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
1991 struct inpcb *inp = tp->t_inpcb;
1993 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
1995 const boolean_t isipv6 = FALSE;
1999 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
2000 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
2001 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
2002 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
2005 rt = tcp_rtlookup6(&inp->inp_inc);
2007 rt = tcp_rtlookup(&inp->inp_inc);
2009 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2010 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2011 *maxsegs = tcp_iw_maxsegs;
2012 *capsegs = tcp_iw_capsegs;
2015 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2016 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2020 tcp_initial_window(struct tcpcb *tp)
2022 if (tcp_do_rfc3390) {
2025 * "If the SYN or SYN/ACK is lost, the initial window
2026 * used by a sender after a correctly transmitted SYN
2027 * MUST be one segment consisting of MSS bytes."
2029 * However, we do something a little bit more aggressive
2030 * then RFC3390 here:
2031 * - Only if time spent in the SYN or SYN|ACK retransmition
2032 * >= 3 seconds, the IW is reduced. We do this mainly
2033 * because when RFC3390 is published, the initial RTO is
2034 * still 3 seconds (the threshold we test here), while
2035 * after RFC6298, the initial RTO is 1 second. This
2036 * behaviour probably still falls within the spirit of
2038 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2039 * Mainly to avoid sender and receiver deadlock until
2040 * delayed ACK timer expires. And even RFC2581 does not
2041 * try to reduce IW upon SYN or SYN|ACK retransmition
2045 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2047 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2048 return (2 * tp->t_maxseg);
2050 u_long maxsegs, capsegs;
2052 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2053 return min(maxsegs * tp->t_maxseg,
2054 max(2 * tp->t_maxseg, capsegs * 1460));
2058 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2060 * Mainly to avoid sender and receiver deadlock
2061 * until delayed ACK timer expires.
2063 return (2 * tp->t_maxseg);
2067 #ifdef TCP_SIGNATURE
2069 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2071 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2072 * When called from tcp_input(), we can be sure that th_sum has been
2073 * zeroed out and verified already.
2075 * Return 0 if successful, otherwise return -1.
2077 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2078 * search with the destination IP address, and a 'magic SPI' to be
2079 * determined by the application. This is hardcoded elsewhere to 1179
2080 * right now. Another branch of this code exists which uses the SPD to
2081 * specify per-application flows but it is unstable.
2084 tcpsignature_compute(
2085 struct mbuf *m, /* mbuf chain */
2086 int len, /* length of TCP data */
2087 int optlen, /* length of TCP options */
2088 u_char *buf, /* storage for MD5 digest */
2089 u_int direction) /* direction of flow */
2091 struct ippseudo ippseudo;
2095 struct ipovly *ipovly;
2096 struct secasvar *sav;
2099 struct ip6_hdr *ip6;
2100 struct in6_addr in6;
2106 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2107 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2109 * Extract the destination from the IP header in the mbuf.
2111 ip = mtod(m, struct ip *);
2113 ip6 = NULL; /* Make the compiler happy. */
2116 * Look up an SADB entry which matches the address found in
2119 switch (IP_VHL_V(ip->ip_vhl)) {
2121 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2122 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2125 case (IPV6_VERSION >> 4):
2126 ip6 = mtod(m, struct ip6_hdr *);
2127 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2128 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2137 kprintf("%s: SADB lookup failed\n", __func__);
2143 * Step 1: Update MD5 hash with IP pseudo-header.
2145 * XXX The ippseudo header MUST be digested in network byte order,
2146 * or else we'll fail the regression test. Assume all fields we've
2147 * been doing arithmetic on have been in host byte order.
2148 * XXX One cannot depend on ipovly->ih_len here. When called from
2149 * tcp_output(), the underlying ip_len member has not yet been set.
2151 switch (IP_VHL_V(ip->ip_vhl)) {
2153 ipovly = (struct ipovly *)ip;
2154 ippseudo.ippseudo_src = ipovly->ih_src;
2155 ippseudo.ippseudo_dst = ipovly->ih_dst;
2156 ippseudo.ippseudo_pad = 0;
2157 ippseudo.ippseudo_p = IPPROTO_TCP;
2158 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2159 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2160 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2161 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2165 * RFC 2385, 2.0 Proposal
2166 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2167 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2168 * extended next header value (to form 32 bits), and 32-bit segment
2170 * Note: Upper-Layer Packet Length comes before Next Header.
2172 case (IPV6_VERSION >> 4):
2174 in6_clearscope(&in6);
2175 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2177 in6_clearscope(&in6);
2178 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2179 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2180 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2182 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2183 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2184 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2186 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2187 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2188 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2197 * Step 2: Update MD5 hash with TCP header, excluding options.
2198 * The TCP checksum must be set to zero.
2200 savecsum = th->th_sum;
2202 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2203 th->th_sum = savecsum;
2205 * Step 3: Update MD5 hash with TCP segment data.
2206 * Use m_apply() to avoid an early m_pullup().
2209 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2211 * Step 4: Update MD5 hash with shared secret.
2213 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2214 MD5Final(buf, &ctx);
2215 key_sa_recordxfer(sav, m);
2221 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2224 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2227 #endif /* TCP_SIGNATURE */