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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12 * notice, this list of conditions and the following disclaimer.
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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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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 MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
270 static struct malloc_pipe tcptemp_mpipe;
272 static void tcp_willblock(void);
273 static void tcp_notify (struct inpcb *, int);
275 struct tcp_stats tcpstats_percpu[MAXCPU];
278 sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
282 for (cpu = 0; cpu < ncpus; ++cpu) {
283 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
284 sizeof(struct tcp_stats))))
286 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
287 sizeof(struct tcp_stats))))
293 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
294 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
296 SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW,
297 &tcpstat, tcp_stats, "TCP statistics");
301 * Target size of TCP PCB hash tables. Must be a power of two.
303 * Note that this can be overridden by the kernel environment
304 * variable net.inet.tcp.tcbhashsize
307 #define TCBHASHSIZE 512
311 * This is the actual shape of what we allocate using the zone
312 * allocator. Doing it this way allows us to protect both structures
313 * using the same generation count, and also eliminates the overhead
314 * of allocating tcpcbs separately. By hiding the structure here,
315 * we avoid changing most of the rest of the code (although it needs
316 * to be changed, eventually, for greater efficiency).
319 #define ALIGNM1 (ALIGNMENT - 1)
323 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
326 struct tcp_callout inp_tp_rexmt;
327 struct tcp_callout inp_tp_persist;
328 struct tcp_callout inp_tp_keep;
329 struct tcp_callout inp_tp_2msl;
330 struct tcp_callout inp_tp_delack;
331 struct netmsg_tcp_timer inp_tp_timermsg;
342 struct inpcbporthead *porthashbase;
343 struct inpcbinfo *ticb;
345 int hashsize = TCBHASHSIZE;
349 * note: tcptemp is used for keepalives, and it is ok for an
350 * allocation to fail so do not specify MPF_INT.
352 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
353 25, -1, 0, NULL, NULL, NULL);
355 tcp_delacktime = TCPTV_DELACK;
356 tcp_keepinit = TCPTV_KEEP_INIT;
357 tcp_keepidle = TCPTV_KEEP_IDLE;
358 tcp_keepintvl = TCPTV_KEEPINTVL;
359 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
361 tcp_rexmit_min = TCPTV_MIN;
362 tcp_rexmit_slop = TCPTV_CPU_VAR;
364 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
365 if (!powerof2(hashsize)) {
366 kprintf("WARNING: TCB hash size not a power of 2\n");
367 hashsize = 512; /* safe default */
369 tcp_tcbhashsize = hashsize;
370 porthashbase = hashinit(hashsize, M_PCB, &porthashmask);
372 for (cpu = 0; cpu < ncpus2; cpu++) {
373 ticb = &tcbinfo[cpu];
374 in_pcbinfo_init(ticb);
376 ticb->hashbase = hashinit(hashsize, M_PCB,
378 ticb->porthashbase = porthashbase;
379 ticb->porthashmask = porthashmask;
380 ticb->porttoken = &tcp_port_token;
382 ticb->porthashbase = hashinit(hashsize, M_PCB,
383 &ticb->porthashmask);
385 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
386 &ticb->wildcardhashmask);
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.
409 for (cpu = 0; cpu < ncpus; ++cpu) {
410 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
413 bzero(&tcpstat, sizeof(struct tcp_stats));
417 netisr_register_rollup(tcp_willblock);
424 int cpu = mycpu->gd_cpuid;
426 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) {
427 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
428 tp->t_flags &= ~TF_ONOUTPUTQ;
429 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq);
435 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
436 * tcp_template used to store this data in mbufs, but we now recopy it out
437 * of the tcpcb each time to conserve mbufs.
440 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr)
442 struct inpcb *inp = tp->t_inpcb;
443 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
446 if (inp->inp_vflag & INP_IPV6) {
449 ip6 = (struct ip6_hdr *)ip_ptr;
450 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
451 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
452 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
453 (IPV6_VERSION & IPV6_VERSION_MASK);
454 ip6->ip6_nxt = IPPROTO_TCP;
455 ip6->ip6_plen = sizeof(struct tcphdr);
456 ip6->ip6_src = inp->in6p_laddr;
457 ip6->ip6_dst = inp->in6p_faddr;
462 struct ip *ip = (struct ip *) ip_ptr;
464 ip->ip_vhl = IP_VHL_BORING;
471 ip->ip_p = IPPROTO_TCP;
472 ip->ip_src = inp->inp_laddr;
473 ip->ip_dst = inp->inp_faddr;
474 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
476 htons(sizeof(struct tcphdr) + IPPROTO_TCP));
479 tcp_hdr->th_sport = inp->inp_lport;
480 tcp_hdr->th_dport = inp->inp_fport;
485 tcp_hdr->th_flags = 0;
491 * Create template to be used to send tcp packets on a connection.
492 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
493 * use for this function is in keepalives, which use tcp_respond.
496 tcp_maketemplate(struct tcpcb *tp)
500 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
502 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t);
507 tcp_freetemplate(struct tcptemp *tmp)
509 mpipe_free(&tcptemp_mpipe, tmp);
513 * Send a single message to the TCP at address specified by
514 * the given TCP/IP header. If m == NULL, then we make a copy
515 * of the tcpiphdr at ti and send directly to the addressed host.
516 * This is used to force keep alive messages out using the TCP
517 * template for a connection. If flags are given then we send
518 * a message back to the TCP which originated the * segment ti,
519 * and discard the mbuf containing it and any other attached mbufs.
521 * In any case the ack and sequence number of the transmitted
522 * segment are as specified by the parameters.
524 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
527 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
528 tcp_seq ack, tcp_seq seq, int flags)
532 struct route *ro = NULL;
534 struct ip *ip = ipgen;
537 struct route_in6 *ro6 = NULL;
538 struct route_in6 sro6;
539 struct ip6_hdr *ip6 = ipgen;
540 boolean_t use_tmpro = TRUE;
542 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
544 const boolean_t isipv6 = FALSE;
548 if (!(flags & TH_RST)) {
549 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv);
552 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
553 win = (long)TCP_MAXWIN << tp->rcv_scale;
556 * Don't use the route cache of a listen socket,
557 * it is not MPSAFE; use temporary route cache.
559 if (tp->t_state != TCPS_LISTEN) {
561 ro6 = &tp->t_inpcb->in6p_route;
563 ro = &tp->t_inpcb->inp_route;
570 bzero(ro6, sizeof *ro6);
573 bzero(ro, sizeof *ro);
577 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
581 m->m_data += max_linkhdr;
583 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
584 ip6 = mtod(m, struct ip6_hdr *);
585 nth = (struct tcphdr *)(ip6 + 1);
587 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
588 ip = mtod(m, struct ip *);
589 nth = (struct tcphdr *)(ip + 1);
591 bcopy(th, nth, sizeof(struct tcphdr));
596 m->m_data = (caddr_t)ipgen;
597 /* m_len is set later */
599 #define xchg(a, b, type) { type t; t = a; a = b; b = t; }
601 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
602 nth = (struct tcphdr *)(ip6 + 1);
604 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
605 nth = (struct tcphdr *)(ip + 1);
609 * this is usually a case when an extension header
610 * exists between the IPv6 header and the
613 nth->th_sport = th->th_sport;
614 nth->th_dport = th->th_dport;
616 xchg(nth->th_dport, nth->th_sport, n_short);
621 ip6->ip6_vfc = IPV6_VERSION;
622 ip6->ip6_nxt = IPPROTO_TCP;
623 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
624 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
626 tlen += sizeof(struct tcpiphdr);
628 ip->ip_ttl = ip_defttl;
631 m->m_pkthdr.len = tlen;
632 m->m_pkthdr.rcvif = NULL;
633 nth->th_seq = htonl(seq);
634 nth->th_ack = htonl(ack);
636 nth->th_off = sizeof(struct tcphdr) >> 2;
637 nth->th_flags = flags;
639 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
641 nth->th_win = htons((u_short)win);
645 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
646 sizeof(struct ip6_hdr),
647 tlen - sizeof(struct ip6_hdr));
648 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
649 (ro6 && ro6->ro_rt) ?
650 ro6->ro_rt->rt_ifp : NULL);
652 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
653 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
654 m->m_pkthdr.csum_flags = CSUM_TCP;
655 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
658 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
659 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
662 ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
663 tp ? tp->t_inpcb : NULL);
664 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
669 ipflags |= IP_DEBUGROUTE;
670 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
671 if ((ro == &sro) && (ro->ro_rt != NULL)) {
679 * Create a new TCP control block, making an
680 * empty reassembly queue and hooking it to the argument
681 * protocol control block. The `inp' parameter must have
682 * come from the zone allocator set up in tcp_init().
685 tcp_newtcpcb(struct inpcb *inp)
690 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
692 const boolean_t isipv6 = FALSE;
695 it = (struct inp_tp *)inp;
697 bzero(tp, sizeof(struct tcpcb));
698 LIST_INIT(&tp->t_segq);
699 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
701 /* Set up our timeouts. */
702 tp->tt_rexmt = &it->inp_tp_rexmt;
703 tp->tt_persist = &it->inp_tp_persist;
704 tp->tt_keep = &it->inp_tp_keep;
705 tp->tt_2msl = &it->inp_tp_2msl;
706 tp->tt_delack = &it->inp_tp_delack;
710 * Zero out timer message. We don't create it here,
711 * since the current CPU may not be the owner of this
714 tp->tt_msg = &it->inp_tp_timermsg;
715 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
717 tp->t_keepinit = tcp_keepinit;
718 tp->t_keepidle = tcp_keepidle;
719 tp->t_keepintvl = tcp_keepintvl;
720 tp->t_keepcnt = tcp_keepcnt;
721 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
724 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP);
725 tp->t_inpcb = inp; /* XXX */
726 tp->t_state = TCPS_CLOSED;
728 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
729 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
730 * reasonable initial retransmit time.
732 tp->t_srtt = TCPTV_SRTTBASE;
734 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
735 tp->t_rttmin = tcp_rexmit_min;
736 tp->t_rxtcur = TCPTV_RTOBASE;
737 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
738 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
739 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
740 tp->snd_last = ticks;
741 tp->t_rcvtime = ticks;
743 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
744 * because the socket may be bound to an IPv6 wildcard address,
745 * which may match an IPv4-mapped IPv6 address.
747 inp->inp_ip_ttl = ip_defttl;
749 tcp_sack_tcpcb_init(tp);
750 return (tp); /* XXX */
754 * Drop a TCP connection, reporting the specified error.
755 * If connection is synchronized, then send a RST to peer.
758 tcp_drop(struct tcpcb *tp, int error)
760 struct socket *so = tp->t_inpcb->inp_socket;
762 if (TCPS_HAVERCVDSYN(tp->t_state)) {
763 tp->t_state = TCPS_CLOSED;
765 tcpstat.tcps_drops++;
767 tcpstat.tcps_conndrops++;
768 if (error == ETIMEDOUT && tp->t_softerror)
769 error = tp->t_softerror;
770 so->so_error = error;
771 return (tcp_close(tp));
776 struct netmsg_listen_detach {
777 struct netmsg_base base;
782 tcp_listen_detach_handler(netmsg_t msg)
784 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
785 struct tcpcb *tp = nmsg->nm_tp;
786 int cpu = mycpuid, nextcpu;
788 if (tp->t_flags & TF_LISTEN)
789 syncache_destroy(tp);
791 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
794 if (nextcpu < ncpus2)
795 lwkt_forwardmsg(cpu_portfn(nextcpu), &nmsg->base.lmsg);
797 lwkt_replymsg(&nmsg->base.lmsg, 0);
803 * Close a TCP control block:
804 * discard all space held by the tcp
805 * discard internet protocol block
806 * wake up any sleepers
809 tcp_close(struct tcpcb *tp)
812 struct inpcb *inp = tp->t_inpcb;
813 struct socket *so = inp->inp_socket;
815 boolean_t dosavessthresh;
817 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
818 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
820 const boolean_t isipv6 = FALSE;
825 * INP_WILDCARD_MP indicates that listen(2) has been called on
826 * this socket. This implies:
827 * - A wildcard inp's hash is replicated for each protocol thread.
828 * - Syncache for this inp grows independently in each protocol
830 * - There is more than one cpu
832 * We have to chain a message to the rest of the protocol threads
833 * to cleanup the wildcard hash and the syncache. The cleanup
834 * in the current protocol thread is defered till the end of this
838 * After cleanup the inp's hash and syncache entries, this inp will
839 * no longer be available to the rest of the protocol threads, so we
840 * are safe to whack the inp in the following code.
842 if (inp->inp_flags & INP_WILDCARD_MP) {
843 struct netmsg_listen_detach nmsg;
845 KKASSERT(so->so_port == cpu_portfn(0));
846 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
847 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
849 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
850 MSGF_PRIORITY, tcp_listen_detach_handler);
852 lwkt_domsg(cpu_portfn(1), &nmsg.base.lmsg, 0);
854 inp->inp_flags &= ~INP_WILDCARD_MP;
858 KKASSERT(tp->t_state != TCPS_TERMINATING);
859 tp->t_state = TCPS_TERMINATING;
862 * Make sure that all of our timers are stopped before we
863 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
864 * timers are never used. If timer message is never created
865 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
867 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
868 tcp_callout_stop(tp, tp->tt_rexmt);
869 tcp_callout_stop(tp, tp->tt_persist);
870 tcp_callout_stop(tp, tp->tt_keep);
871 tcp_callout_stop(tp, tp->tt_2msl);
872 tcp_callout_stop(tp, tp->tt_delack);
875 if (tp->t_flags & TF_ONOUTPUTQ) {
876 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
877 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
878 tp->t_flags &= ~TF_ONOUTPUTQ;
882 * If we got enough samples through the srtt filter,
883 * save the rtt and rttvar in the routing entry.
884 * 'Enough' is arbitrarily defined as the 16 samples.
885 * 16 samples is enough for the srtt filter to converge
886 * to within 5% of the correct value; fewer samples and
887 * we could save a very bogus rtt.
889 * Don't update the default route's characteristics and don't
890 * update anything that the user "locked".
892 if (tp->t_rttupdated >= 16) {
896 struct sockaddr_in6 *sin6;
898 if ((rt = inp->in6p_route.ro_rt) == NULL)
900 sin6 = (struct sockaddr_in6 *)rt_key(rt);
901 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
904 if ((rt = inp->inp_route.ro_rt) == NULL ||
905 ((struct sockaddr_in *)rt_key(rt))->
906 sin_addr.s_addr == INADDR_ANY)
909 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
910 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
911 if (rt->rt_rmx.rmx_rtt && i)
913 * filter this update to half the old & half
914 * the new values, converting scale.
915 * See route.h and tcp_var.h for a
916 * description of the scaling constants.
919 (rt->rt_rmx.rmx_rtt + i) / 2;
921 rt->rt_rmx.rmx_rtt = i;
922 tcpstat.tcps_cachedrtt++;
924 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
926 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
927 if (rt->rt_rmx.rmx_rttvar && i)
928 rt->rt_rmx.rmx_rttvar =
929 (rt->rt_rmx.rmx_rttvar + i) / 2;
931 rt->rt_rmx.rmx_rttvar = i;
932 tcpstat.tcps_cachedrttvar++;
935 * The old comment here said:
936 * update the pipelimit (ssthresh) if it has been updated
937 * already or if a pipesize was specified & the threshhold
938 * got below half the pipesize. I.e., wait for bad news
939 * before we start updating, then update on both good
942 * But we want to save the ssthresh even if no pipesize is
943 * specified explicitly in the route, because such
944 * connections still have an implicit pipesize specified
945 * by the global tcp_sendspace. In the absence of a reliable
946 * way to calculate the pipesize, it will have to do.
948 i = tp->snd_ssthresh;
949 if (rt->rt_rmx.rmx_sendpipe != 0)
950 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
952 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
953 if (dosavessthresh ||
954 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
955 (rt->rt_rmx.rmx_ssthresh != 0))) {
957 * convert the limit from user data bytes to
958 * packets then to packet data bytes.
960 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
965 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
966 sizeof(struct tcpiphdr));
967 if (rt->rt_rmx.rmx_ssthresh)
968 rt->rt_rmx.rmx_ssthresh =
969 (rt->rt_rmx.rmx_ssthresh + i) / 2;
971 rt->rt_rmx.rmx_ssthresh = i;
972 tcpstat.tcps_cachedssthresh++;
977 /* free the reassembly queue, if any */
978 while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
979 LIST_REMOVE(q, tqe_q);
982 atomic_add_int(&tcp_reass_qsize, -1);
984 /* throw away SACK blocks in scoreboard*/
986 tcp_sack_destroy(&tp->scb);
988 inp->inp_ppcb = NULL;
989 soisdisconnected(so);
990 /* note: pcb detached later on */
992 tcp_destroy_timermsg(tp);
994 if (tp->t_flags & TF_LISTEN)
995 syncache_destroy(tp);
999 * pcbdetach removes any wildcard hash entry on the current CPU.
1008 tcpstat.tcps_closed++;
1012 static __inline void
1013 tcp_drain_oncpu(struct inpcbhead *head)
1015 struct inpcb *marker;
1018 struct tseg_qent *te;
1021 * Allows us to block while running the list
1023 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1024 marker->inp_flags |= INP_PLACEMARKER;
1025 LIST_INSERT_HEAD(head, marker, inp_list);
1027 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) {
1028 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1029 (tcpb = intotcpcb(inpb)) != NULL &&
1030 (te = LIST_FIRST(&tcpb->t_segq)) != NULL) {
1031 LIST_REMOVE(te, tqe_q);
1034 atomic_add_int(&tcp_reass_qsize, -1);
1037 LIST_REMOVE(marker, inp_list);
1038 LIST_INSERT_AFTER(inpb, marker, inp_list);
1041 LIST_REMOVE(marker, inp_list);
1042 kfree(marker, M_TEMP);
1046 struct netmsg_tcp_drain {
1047 struct netmsg_base base;
1048 struct inpcbhead *nm_head;
1052 tcp_drain_handler(netmsg_t msg)
1054 struct netmsg_tcp_drain *nm = (void *)msg;
1056 tcp_drain_oncpu(nm->nm_head);
1057 lwkt_replymsg(&nm->base.lmsg, 0);
1072 * Walk the tcpbs, if existing, and flush the reassembly queue,
1073 * if there is one...
1074 * XXX: The "Net/3" implementation doesn't imply that the TCP
1075 * reassembly queue should be flushed, but in a situation
1076 * where we're really low on mbufs, this is potentially
1080 for (cpu = 0; cpu < ncpus2; cpu++) {
1081 struct netmsg_tcp_drain *nm;
1083 if (cpu == mycpu->gd_cpuid) {
1084 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead);
1086 nm = kmalloc(sizeof(struct netmsg_tcp_drain),
1087 M_LWKTMSG, M_NOWAIT);
1090 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1091 0, tcp_drain_handler);
1092 nm->nm_head = &tcbinfo[cpu].pcblisthead;
1093 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg);
1097 tcp_drain_oncpu(&tcbinfo[0].pcblisthead);
1102 * Notify a tcp user of an asynchronous error;
1103 * store error as soft error, but wake up user
1104 * (for now, won't do anything until can select for soft error).
1106 * Do not wake up user since there currently is no mechanism for
1107 * reporting soft errors (yet - a kqueue filter may be added).
1110 tcp_notify(struct inpcb *inp, int error)
1112 struct tcpcb *tp = intotcpcb(inp);
1115 * Ignore some errors if we are hooked up.
1116 * If connection hasn't completed, has retransmitted several times,
1117 * and receives a second error, give up now. This is better
1118 * than waiting a long time to establish a connection that
1119 * can never complete.
1121 if (tp->t_state == TCPS_ESTABLISHED &&
1122 (error == EHOSTUNREACH || error == ENETUNREACH ||
1123 error == EHOSTDOWN)) {
1125 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1127 tcp_drop(tp, error);
1129 tp->t_softerror = error;
1131 wakeup(&so->so_timeo);
1138 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1141 struct inpcb *marker;
1150 * The process of preparing the TCB list is too time-consuming and
1151 * resource-intensive to repeat twice on every request.
1153 if (req->oldptr == NULL) {
1154 for (ccpu = 0; ccpu < ncpus; ++ccpu) {
1155 gd = globaldata_find(ccpu);
1156 n += tcbinfo[gd->gd_cpuid].ipi_count;
1158 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1162 if (req->newptr != NULL)
1165 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1166 marker->inp_flags |= INP_PLACEMARKER;
1169 * OK, now we're committed to doing something. Run the inpcb list
1170 * for each cpu in the system and construct the output. Use a
1171 * list placemarker to deal with list changes occuring during
1172 * copyout blockages (but otherwise depend on being on the correct
1173 * cpu to avoid races).
1175 origcpu = mycpu->gd_cpuid;
1176 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) {
1182 cpu_id = (origcpu + ccpu) % ncpus;
1183 if ((smp_active_mask & CPUMASK(cpu_id)) == 0)
1185 rgd = globaldata_find(cpu_id);
1186 lwkt_setcpu_self(rgd);
1188 n = tcbinfo[cpu_id].ipi_count;
1190 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list);
1192 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1194 * process a snapshot of pcbs, ignoring placemarkers
1195 * and using our own to allow SYSCTL_OUT to block.
1197 LIST_REMOVE(marker, inp_list);
1198 LIST_INSERT_AFTER(inp, marker, inp_list);
1200 if (inp->inp_flags & INP_PLACEMARKER)
1202 if (prison_xinpcb(req->td, inp))
1205 xt.xt_len = sizeof xt;
1206 bcopy(inp, &xt.xt_inp, sizeof *inp);
1207 inp_ppcb = inp->inp_ppcb;
1208 if (inp_ppcb != NULL)
1209 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1211 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1212 if (inp->inp_socket)
1213 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1214 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1218 LIST_REMOVE(marker, inp_list);
1219 if (error == 0 && i < n) {
1220 bzero(&xt, sizeof xt);
1221 xt.xt_len = sizeof xt;
1223 error = SYSCTL_OUT(req, &xt, sizeof xt);
1232 * Make sure we are on the same cpu we were on originally, since
1233 * higher level callers expect this. Also don't pollute caches with
1234 * migrated userland data by (eventually) returning to userland
1235 * on a different cpu.
1237 lwkt_setcpu_self(globaldata_find(origcpu));
1238 kfree(marker, M_TEMP);
1242 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1243 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1246 tcp_getcred(SYSCTL_HANDLER_ARGS)
1248 struct sockaddr_in addrs[2];
1253 error = priv_check(req->td, PRIV_ROOT);
1256 error = SYSCTL_IN(req, addrs, sizeof addrs);
1260 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1261 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1262 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1263 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1264 if (inp == NULL || inp->inp_socket == NULL) {
1268 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1274 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1275 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1279 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1281 struct sockaddr_in6 addrs[2];
1284 boolean_t mapped = FALSE;
1286 error = priv_check(req->td, PRIV_ROOT);
1289 error = SYSCTL_IN(req, addrs, sizeof addrs);
1292 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1293 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1300 inp = in_pcblookup_hash(&tcbinfo[0],
1301 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1303 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1307 inp = in6_pcblookup_hash(&tcbinfo[0],
1308 &addrs[1].sin6_addr, addrs[1].sin6_port,
1309 &addrs[0].sin6_addr, addrs[0].sin6_port,
1312 if (inp == NULL || inp->inp_socket == NULL) {
1316 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1322 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1324 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1327 struct netmsg_tcp_notify {
1328 struct netmsg_base base;
1329 void (*nm_notify)(struct inpcb *, int);
1330 struct in_addr nm_faddr;
1335 tcp_notifyall_oncpu(netmsg_t msg)
1337 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1340 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr,
1341 nm->nm_arg, nm->nm_notify);
1343 nextcpu = mycpuid + 1;
1344 if (nextcpu < ncpus2)
1345 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
1347 lwkt_replymsg(&nm->base.lmsg, 0);
1351 tcp_ctlinput(netmsg_t msg)
1353 int cmd = msg->ctlinput.nm_cmd;
1354 struct sockaddr *sa = msg->ctlinput.nm_arg;
1355 struct ip *ip = msg->ctlinput.nm_extra;
1357 struct in_addr faddr;
1360 void (*notify)(struct inpcb *, int) = tcp_notify;
1364 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1368 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1369 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1372 arg = inetctlerrmap[cmd];
1373 if (cmd == PRC_QUENCH) {
1374 notify = tcp_quench;
1375 } else if (icmp_may_rst &&
1376 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1377 cmd == PRC_UNREACH_PORT ||
1378 cmd == PRC_TIMXCEED_INTRANS) &&
1380 notify = tcp_drop_syn_sent;
1381 } else if (cmd == PRC_MSGSIZE) {
1382 struct icmp *icmp = (struct icmp *)
1383 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1385 arg = ntohs(icmp->icmp_nextmtu);
1386 notify = tcp_mtudisc;
1387 } else if (PRC_IS_REDIRECT(cmd)) {
1389 notify = in_rtchange;
1390 } else if (cmd == PRC_HOSTDEAD) {
1396 th = (struct tcphdr *)((caddr_t)ip +
1397 (IP_VHL_HL(ip->ip_vhl) << 2));
1398 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
1399 ip->ip_src.s_addr, th->th_sport);
1400 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
1401 ip->ip_src, th->th_sport, 0, NULL);
1402 if ((inp != NULL) && (inp->inp_socket != NULL)) {
1403 icmpseq = htonl(th->th_seq);
1404 tp = intotcpcb(inp);
1405 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1406 SEQ_LT(icmpseq, tp->snd_max))
1407 (*notify)(inp, arg);
1409 struct in_conninfo inc;
1411 inc.inc_fport = th->th_dport;
1412 inc.inc_lport = th->th_sport;
1413 inc.inc_faddr = faddr;
1414 inc.inc_laddr = ip->ip_src;
1418 syncache_unreach(&inc, th);
1422 struct netmsg_tcp_notify *nm;
1424 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
1425 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1426 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1427 0, tcp_notifyall_oncpu);
1428 nm->nm_faddr = faddr;
1430 nm->nm_notify = notify;
1432 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg);
1435 lwkt_replymsg(&msg->lmsg, 0);
1441 tcp6_ctlinput(netmsg_t msg)
1443 int cmd = msg->ctlinput.nm_cmd;
1444 struct sockaddr *sa = msg->ctlinput.nm_arg;
1445 void *d = msg->ctlinput.nm_extra;
1447 void (*notify) (struct inpcb *, int) = tcp_notify;
1448 struct ip6_hdr *ip6;
1450 struct ip6ctlparam *ip6cp = NULL;
1451 const struct sockaddr_in6 *sa6_src = NULL;
1453 struct tcp_portonly {
1459 if (sa->sa_family != AF_INET6 ||
1460 sa->sa_len != sizeof(struct sockaddr_in6)) {
1465 if (cmd == PRC_QUENCH)
1466 notify = tcp_quench;
1467 else if (cmd == PRC_MSGSIZE) {
1468 struct ip6ctlparam *ip6cp = d;
1469 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1471 arg = ntohl(icmp6->icmp6_mtu);
1472 notify = tcp_mtudisc;
1473 } else if (!PRC_IS_REDIRECT(cmd) &&
1474 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1478 /* if the parameter is from icmp6, decode it. */
1480 ip6cp = (struct ip6ctlparam *)d;
1482 ip6 = ip6cp->ip6c_ip6;
1483 off = ip6cp->ip6c_off;
1484 sa6_src = ip6cp->ip6c_src;
1488 off = 0; /* fool gcc */
1493 struct in_conninfo inc;
1495 * XXX: We assume that when IPV6 is non NULL,
1496 * M and OFF are valid.
1499 /* check if we can safely examine src and dst ports */
1500 if (m->m_pkthdr.len < off + sizeof *thp)
1503 bzero(&th, sizeof th);
1504 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
1506 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport,
1507 (struct sockaddr *)ip6cp->ip6c_src,
1508 th.th_sport, cmd, arg, notify);
1510 inc.inc_fport = th.th_dport;
1511 inc.inc_lport = th.th_sport;
1512 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1513 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1515 syncache_unreach(&inc, &th);
1517 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0,
1518 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1521 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1527 * Following is where TCP initial sequence number generation occurs.
1529 * There are two places where we must use initial sequence numbers:
1530 * 1. In SYN-ACK packets.
1531 * 2. In SYN packets.
1533 * All ISNs for SYN-ACK packets are generated by the syncache. See
1534 * tcp_syncache.c for details.
1536 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1537 * depends on this property. In addition, these ISNs should be
1538 * unguessable so as to prevent connection hijacking. To satisfy
1539 * the requirements of this situation, the algorithm outlined in
1540 * RFC 1948 is used to generate sequence numbers.
1542 * Implementation details:
1544 * Time is based off the system timer, and is corrected so that it
1545 * increases by one megabyte per second. This allows for proper
1546 * recycling on high speed LANs while still leaving over an hour
1549 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1550 * between seeding of isn_secret. This is normally set to zero,
1551 * as reseeding should not be necessary.
1555 #define ISN_BYTES_PER_SECOND 1048576
1557 u_char isn_secret[32];
1558 int isn_last_reseed;
1562 tcp_new_isn(struct tcpcb *tp)
1564 u_int32_t md5_buffer[4];
1567 /* Seed if this is the first use, reseed if requested. */
1568 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1569 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1571 read_random_unlimited(&isn_secret, sizeof isn_secret);
1572 isn_last_reseed = ticks;
1575 /* Compute the md5 hash and return the ISN. */
1577 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1578 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
1580 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
1581 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1582 sizeof(struct in6_addr));
1583 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1584 sizeof(struct in6_addr));
1588 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1589 sizeof(struct in_addr));
1590 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1591 sizeof(struct in_addr));
1593 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1594 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1595 new_isn = (tcp_seq) md5_buffer[0];
1596 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
1601 * When a source quench is received, close congestion window
1602 * to one segment. We will gradually open it again as we proceed.
1605 tcp_quench(struct inpcb *inp, int error)
1607 struct tcpcb *tp = intotcpcb(inp);
1610 tp->snd_cwnd = tp->t_maxseg;
1616 * When a specific ICMP unreachable message is received and the
1617 * connection state is SYN-SENT, drop the connection. This behavior
1618 * is controlled by the icmp_may_rst sysctl.
1621 tcp_drop_syn_sent(struct inpcb *inp, int error)
1623 struct tcpcb *tp = intotcpcb(inp);
1625 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
1626 tcp_drop(tp, error);
1630 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1631 * based on the new value in the route. Also nudge TCP to send something,
1632 * since we know the packet we just sent was dropped.
1633 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1636 tcp_mtudisc(struct inpcb *inp, int mtu)
1638 struct tcpcb *tp = intotcpcb(inp);
1640 struct socket *so = inp->inp_socket;
1643 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1645 const boolean_t isipv6 = FALSE;
1652 * If no MTU is provided in the ICMP message, use the
1653 * next lower likely value, as specified in RFC 1191.
1658 oldmtu = tp->t_maxopd +
1660 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1661 sizeof(struct tcpiphdr));
1662 mtu = ip_next_mtu(oldmtu, 0);
1666 rt = tcp_rtlookup6(&inp->inp_inc);
1668 rt = tcp_rtlookup(&inp->inp_inc);
1670 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1671 mtu = rt->rt_rmx.rmx_mtu;
1675 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1676 sizeof(struct tcpiphdr));
1679 * XXX - The following conditional probably violates the TCP
1680 * spec. The problem is that, since we don't know the
1681 * other end's MSS, we are supposed to use a conservative
1682 * default. But, if we do that, then MTU discovery will
1683 * never actually take place, because the conservative
1684 * default is much less than the MTUs typically seen
1685 * on the Internet today. For the moment, we'll sweep
1686 * this under the carpet.
1688 * The conservative default might not actually be a problem
1689 * if the only case this occurs is when sending an initial
1690 * SYN with options and data to a host we've never talked
1691 * to before. Then, they will reply with an MSS value which
1692 * will get recorded and the new parameters should get
1693 * recomputed. For Further Study.
1695 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1696 maxopd = rt->rt_rmx.rmx_mssopt;
1700 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1701 sizeof(struct tcpiphdr));
1703 if (tp->t_maxopd <= maxopd)
1705 tp->t_maxopd = maxopd;
1708 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1709 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1710 mss -= TCPOLEN_TSTAMP_APPA;
1712 /* round down to multiple of MCLBYTES */
1713 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1715 mss &= ~(MCLBYTES - 1);
1718 mss = (mss / MCLBYTES) * MCLBYTES;
1721 if (so->so_snd.ssb_hiwat < mss)
1722 mss = so->so_snd.ssb_hiwat;
1726 tp->snd_nxt = tp->snd_una;
1728 tcpstat.tcps_mturesent++;
1732 * Look-up the routing entry to the peer of this inpcb. If no route
1733 * is found and it cannot be allocated the return NULL. This routine
1734 * is called by TCP routines that access the rmx structure and by tcp_mss
1735 * to get the interface MTU.
1738 tcp_rtlookup(struct in_conninfo *inc)
1740 struct route *ro = &inc->inc_route;
1742 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1743 /* No route yet, so try to acquire one */
1744 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1746 * unused portions of the structure MUST be zero'd
1747 * out because rtalloc() treats it as opaque data
1749 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1750 ro->ro_dst.sa_family = AF_INET;
1751 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1752 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1762 tcp_rtlookup6(struct in_conninfo *inc)
1764 struct route_in6 *ro6 = &inc->inc6_route;
1766 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1767 /* No route yet, so try to acquire one */
1768 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1770 * unused portions of the structure MUST be zero'd
1771 * out because rtalloc() treats it as opaque data
1773 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1774 ro6->ro_dst.sin6_family = AF_INET6;
1775 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1776 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1777 rtalloc((struct route *)ro6);
1780 return (ro6->ro_rt);
1785 /* compute ESP/AH header size for TCP, including outer IP header. */
1787 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1795 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1797 MGETHDR(m, MB_DONTWAIT, MT_DATA);
1802 if (inp->inp_vflag & INP_IPV6) {
1803 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1805 th = (struct tcphdr *)(ip6 + 1);
1806 m->m_pkthdr.len = m->m_len =
1807 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1808 tcp_fillheaders(tp, ip6, th);
1809 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1813 ip = mtod(m, struct ip *);
1814 th = (struct tcphdr *)(ip + 1);
1815 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1816 tcp_fillheaders(tp, ip, th);
1817 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1826 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1828 * This code attempts to calculate the bandwidth-delay product as a
1829 * means of determining the optimal window size to maximize bandwidth,
1830 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1831 * routers. This code also does a fairly good job keeping RTTs in check
1832 * across slow links like modems. We implement an algorithm which is very
1833 * similar (but not meant to be) TCP/Vegas. The code operates on the
1834 * transmitter side of a TCP connection and so only effects the transmit
1835 * side of the connection.
1837 * BACKGROUND: TCP makes no provision for the management of buffer space
1838 * at the end points or at the intermediate routers and switches. A TCP
1839 * stream, whether using NewReno or not, will eventually buffer as
1840 * many packets as it is able and the only reason this typically works is
1841 * due to the fairly small default buffers made available for a connection
1842 * (typicaly 16K or 32K). As machines use larger windows and/or window
1843 * scaling it is now fairly easy for even a single TCP connection to blow-out
1844 * all available buffer space not only on the local interface, but on
1845 * intermediate routers and switches as well. NewReno makes a misguided
1846 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1847 * then backing off, then steadily increasing the window again until another
1848 * failure occurs, ad-infinitum. This results in terrible oscillation that
1849 * is only made worse as network loads increase and the idea of intentionally
1850 * blowing out network buffers is, frankly, a terrible way to manage network
1853 * It is far better to limit the transmit window prior to the failure
1854 * condition being achieved. There are two general ways to do this: First
1855 * you can 'scan' through different transmit window sizes and locate the
1856 * point where the RTT stops increasing, indicating that you have filled the
1857 * pipe, then scan backwards until you note that RTT stops decreasing, then
1858 * repeat ad-infinitum. This method works in principle but has severe
1859 * implementation issues due to RTT variances, timer granularity, and
1860 * instability in the algorithm which can lead to many false positives and
1861 * create oscillations as well as interact badly with other TCP streams
1862 * implementing the same algorithm.
1864 * The second method is to limit the window to the bandwidth delay product
1865 * of the link. This is the method we implement. RTT variances and our
1866 * own manipulation of the congestion window, bwnd, can potentially
1867 * destabilize the algorithm. For this reason we have to stabilize the
1868 * elements used to calculate the window. We do this by using the minimum
1869 * observed RTT, the long term average of the observed bandwidth, and
1870 * by adding two segments worth of slop. It isn't perfect but it is able
1871 * to react to changing conditions and gives us a very stable basis on
1872 * which to extend the algorithm.
1875 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1883 * If inflight_enable is disabled in the middle of a tcp connection,
1884 * make sure snd_bwnd is effectively disabled.
1886 if (!tcp_inflight_enable) {
1887 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1888 tp->snd_bandwidth = 0;
1893 * Validate the delta time. If a connection is new or has been idle
1894 * a long time we have to reset the bandwidth calculator.
1897 delta_ticks = save_ticks - tp->t_bw_rtttime;
1898 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1899 tp->t_bw_rtttime = ticks;
1900 tp->t_bw_rtseq = ack_seq;
1901 if (tp->snd_bandwidth == 0)
1902 tp->snd_bandwidth = tcp_inflight_min;
1905 if (delta_ticks == 0)
1909 * Sanity check, plus ignore pure window update acks.
1911 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1915 * Figure out the bandwidth. Due to the tick granularity this
1916 * is a very rough number and it MUST be averaged over a fairly
1917 * long period of time. XXX we need to take into account a link
1918 * that is not using all available bandwidth, but for now our
1919 * slop will ramp us up if this case occurs and the bandwidth later
1922 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
1923 tp->t_bw_rtttime = save_ticks;
1924 tp->t_bw_rtseq = ack_seq;
1925 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
1927 tp->snd_bandwidth = bw;
1930 * Calculate the semi-static bandwidth delay product, plus two maximal
1931 * segments. The additional slop puts us squarely in the sweet
1932 * spot and also handles the bandwidth run-up case. Without the
1933 * slop we could be locking ourselves into a lower bandwidth.
1935 * Situations Handled:
1936 * (1) Prevents over-queueing of packets on LANs, especially on
1937 * high speed LANs, allowing larger TCP buffers to be
1938 * specified, and also does a good job preventing
1939 * over-queueing of packets over choke points like modems
1940 * (at least for the transmit side).
1942 * (2) Is able to handle changing network loads (bandwidth
1943 * drops so bwnd drops, bandwidth increases so bwnd
1946 * (3) Theoretically should stabilize in the face of multiple
1947 * connections implementing the same algorithm (this may need
1950 * (4) Stability value (defaults to 20 = 2 maximal packets) can
1951 * be adjusted with a sysctl but typically only needs to be on
1952 * very slow connections. A value no smaller then 5 should
1953 * be used, but only reduce this default if you have no other
1957 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
1958 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
1959 tcp_inflight_stab * (int)tp->t_maxseg / 10;
1962 if (tcp_inflight_debug > 0) {
1964 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
1966 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
1967 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd);
1970 if ((long)bwnd < tcp_inflight_min)
1971 bwnd = tcp_inflight_min;
1972 if (bwnd > tcp_inflight_max)
1973 bwnd = tcp_inflight_max;
1974 if ((long)bwnd < tp->t_maxseg * 2)
1975 bwnd = tp->t_maxseg * 2;
1976 tp->snd_bwnd = bwnd;
1980 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
1983 struct inpcb *inp = tp->t_inpcb;
1985 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
1987 const boolean_t isipv6 = FALSE;
1991 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
1992 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
1993 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
1994 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
1997 rt = tcp_rtlookup6(&inp->inp_inc);
1999 rt = tcp_rtlookup(&inp->inp_inc);
2001 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2002 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2003 *maxsegs = tcp_iw_maxsegs;
2004 *capsegs = tcp_iw_capsegs;
2007 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2008 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2012 tcp_initial_window(struct tcpcb *tp)
2014 if (tcp_do_rfc3390) {
2017 * "If the SYN or SYN/ACK is lost, the initial window
2018 * used by a sender after a correctly transmitted SYN
2019 * MUST be one segment consisting of MSS bytes."
2021 * However, we do something a little bit more aggressive
2022 * then RFC3390 here:
2023 * - Only if time spent in the SYN or SYN|ACK retransmition
2024 * >= 3 seconds, the IW is reduced. We do this mainly
2025 * because when RFC3390 is published, the initial RTO is
2026 * still 3 seconds (the threshold we test here), while
2027 * after RFC6298, the initial RTO is 1 second. This
2028 * behaviour probably still falls within the spirit of
2030 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2031 * Mainly to avoid sender and receiver deadlock until
2032 * delayed ACK timer expires. And even RFC2581 does not
2033 * try to reduce IW upon SYN or SYN|ACK retransmition
2037 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2039 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2040 return (2 * tp->t_maxseg);
2042 u_long maxsegs, capsegs;
2044 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2045 return min(maxsegs * tp->t_maxseg,
2046 max(2 * tp->t_maxseg, capsegs * 1460));
2050 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2052 * Mainly to avoid sender and receiver deadlock
2053 * until delayed ACK timer expires.
2055 return (2 * tp->t_maxseg);
2059 #ifdef TCP_SIGNATURE
2061 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2063 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2064 * When called from tcp_input(), we can be sure that th_sum has been
2065 * zeroed out and verified already.
2067 * Return 0 if successful, otherwise return -1.
2069 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2070 * search with the destination IP address, and a 'magic SPI' to be
2071 * determined by the application. This is hardcoded elsewhere to 1179
2072 * right now. Another branch of this code exists which uses the SPD to
2073 * specify per-application flows but it is unstable.
2076 tcpsignature_compute(
2077 struct mbuf *m, /* mbuf chain */
2078 int len, /* length of TCP data */
2079 int optlen, /* length of TCP options */
2080 u_char *buf, /* storage for MD5 digest */
2081 u_int direction) /* direction of flow */
2083 struct ippseudo ippseudo;
2087 struct ipovly *ipovly;
2088 struct secasvar *sav;
2091 struct ip6_hdr *ip6;
2092 struct in6_addr in6;
2098 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2099 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2101 * Extract the destination from the IP header in the mbuf.
2103 ip = mtod(m, struct ip *);
2105 ip6 = NULL; /* Make the compiler happy. */
2108 * Look up an SADB entry which matches the address found in
2111 switch (IP_VHL_V(ip->ip_vhl)) {
2113 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2114 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2117 case (IPV6_VERSION >> 4):
2118 ip6 = mtod(m, struct ip6_hdr *);
2119 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2120 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2129 kprintf("%s: SADB lookup failed\n", __func__);
2135 * Step 1: Update MD5 hash with IP pseudo-header.
2137 * XXX The ippseudo header MUST be digested in network byte order,
2138 * or else we'll fail the regression test. Assume all fields we've
2139 * been doing arithmetic on have been in host byte order.
2140 * XXX One cannot depend on ipovly->ih_len here. When called from
2141 * tcp_output(), the underlying ip_len member has not yet been set.
2143 switch (IP_VHL_V(ip->ip_vhl)) {
2145 ipovly = (struct ipovly *)ip;
2146 ippseudo.ippseudo_src = ipovly->ih_src;
2147 ippseudo.ippseudo_dst = ipovly->ih_dst;
2148 ippseudo.ippseudo_pad = 0;
2149 ippseudo.ippseudo_p = IPPROTO_TCP;
2150 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2151 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2152 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2153 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2157 * RFC 2385, 2.0 Proposal
2158 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2159 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2160 * extended next header value (to form 32 bits), and 32-bit segment
2162 * Note: Upper-Layer Packet Length comes before Next Header.
2164 case (IPV6_VERSION >> 4):
2166 in6_clearscope(&in6);
2167 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2169 in6_clearscope(&in6);
2170 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2171 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2172 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2174 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2175 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2176 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2178 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2179 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2180 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2189 * Step 2: Update MD5 hash with TCP header, excluding options.
2190 * The TCP checksum must be set to zero.
2192 savecsum = th->th_sum;
2194 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2195 th->th_sum = savecsum;
2197 * Step 3: Update MD5 hash with TCP segment data.
2198 * Use m_apply() to avoid an early m_pullup().
2201 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2203 * Step 4: Update MD5 hash with shared secret.
2205 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2206 MD5Final(buf, &ctx);
2207 key_sa_recordxfer(sav, m);
2213 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2216 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2219 #endif /* TCP_SIGNATURE */