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->t_rcvtime = ticks;
742 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
743 * because the socket may be bound to an IPv6 wildcard address,
744 * which may match an IPv4-mapped IPv6 address.
746 inp->inp_ip_ttl = ip_defttl;
748 tcp_sack_tcpcb_init(tp);
749 return (tp); /* XXX */
753 * Drop a TCP connection, reporting the specified error.
754 * If connection is synchronized, then send a RST to peer.
757 tcp_drop(struct tcpcb *tp, int error)
759 struct socket *so = tp->t_inpcb->inp_socket;
761 if (TCPS_HAVERCVDSYN(tp->t_state)) {
762 tp->t_state = TCPS_CLOSED;
764 tcpstat.tcps_drops++;
766 tcpstat.tcps_conndrops++;
767 if (error == ETIMEDOUT && tp->t_softerror)
768 error = tp->t_softerror;
769 so->so_error = error;
770 return (tcp_close(tp));
775 struct netmsg_listen_detach {
776 struct netmsg_base base;
781 tcp_listen_detach_handler(netmsg_t msg)
783 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
784 struct tcpcb *tp = nmsg->nm_tp;
785 int cpu = mycpuid, nextcpu;
787 if (tp->t_flags & TF_LISTEN)
788 syncache_destroy(tp);
790 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
793 if (nextcpu < ncpus2)
794 lwkt_forwardmsg(cpu_portfn(nextcpu), &nmsg->base.lmsg);
796 lwkt_replymsg(&nmsg->base.lmsg, 0);
802 * Close a TCP control block:
803 * discard all space held by the tcp
804 * discard internet protocol block
805 * wake up any sleepers
808 tcp_close(struct tcpcb *tp)
811 struct inpcb *inp = tp->t_inpcb;
812 struct socket *so = inp->inp_socket;
814 boolean_t dosavessthresh;
816 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
817 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
819 const boolean_t isipv6 = FALSE;
824 * INP_WILDCARD_MP indicates that listen(2) has been called on
825 * this socket. This implies:
826 * - A wildcard inp's hash is replicated for each protocol thread.
827 * - Syncache for this inp grows independently in each protocol
829 * - There is more than one cpu
831 * We have to chain a message to the rest of the protocol threads
832 * to cleanup the wildcard hash and the syncache. The cleanup
833 * in the current protocol thread is defered till the end of this
837 * After cleanup the inp's hash and syncache entries, this inp will
838 * no longer be available to the rest of the protocol threads, so we
839 * are safe to whack the inp in the following code.
841 if (inp->inp_flags & INP_WILDCARD_MP) {
842 struct netmsg_listen_detach nmsg;
844 KKASSERT(so->so_port == cpu_portfn(0));
845 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
846 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
848 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
849 MSGF_PRIORITY, tcp_listen_detach_handler);
851 lwkt_domsg(cpu_portfn(1), &nmsg.base.lmsg, 0);
853 inp->inp_flags &= ~INP_WILDCARD_MP;
857 KKASSERT(tp->t_state != TCPS_TERMINATING);
858 tp->t_state = TCPS_TERMINATING;
861 * Make sure that all of our timers are stopped before we
862 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
863 * timers are never used. If timer message is never created
864 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
866 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
867 tcp_callout_stop(tp, tp->tt_rexmt);
868 tcp_callout_stop(tp, tp->tt_persist);
869 tcp_callout_stop(tp, tp->tt_keep);
870 tcp_callout_stop(tp, tp->tt_2msl);
871 tcp_callout_stop(tp, tp->tt_delack);
874 if (tp->t_flags & TF_ONOUTPUTQ) {
875 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
876 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
877 tp->t_flags &= ~TF_ONOUTPUTQ;
881 * If we got enough samples through the srtt filter,
882 * save the rtt and rttvar in the routing entry.
883 * 'Enough' is arbitrarily defined as the 16 samples.
884 * 16 samples is enough for the srtt filter to converge
885 * to within 5% of the correct value; fewer samples and
886 * we could save a very bogus rtt.
888 * Don't update the default route's characteristics and don't
889 * update anything that the user "locked".
891 if (tp->t_rttupdated >= 16) {
895 struct sockaddr_in6 *sin6;
897 if ((rt = inp->in6p_route.ro_rt) == NULL)
899 sin6 = (struct sockaddr_in6 *)rt_key(rt);
900 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
903 if ((rt = inp->inp_route.ro_rt) == NULL ||
904 ((struct sockaddr_in *)rt_key(rt))->
905 sin_addr.s_addr == INADDR_ANY)
908 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
909 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
910 if (rt->rt_rmx.rmx_rtt && i)
912 * filter this update to half the old & half
913 * the new values, converting scale.
914 * See route.h and tcp_var.h for a
915 * description of the scaling constants.
918 (rt->rt_rmx.rmx_rtt + i) / 2;
920 rt->rt_rmx.rmx_rtt = i;
921 tcpstat.tcps_cachedrtt++;
923 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
925 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
926 if (rt->rt_rmx.rmx_rttvar && i)
927 rt->rt_rmx.rmx_rttvar =
928 (rt->rt_rmx.rmx_rttvar + i) / 2;
930 rt->rt_rmx.rmx_rttvar = i;
931 tcpstat.tcps_cachedrttvar++;
934 * The old comment here said:
935 * update the pipelimit (ssthresh) if it has been updated
936 * already or if a pipesize was specified & the threshhold
937 * got below half the pipesize. I.e., wait for bad news
938 * before we start updating, then update on both good
941 * But we want to save the ssthresh even if no pipesize is
942 * specified explicitly in the route, because such
943 * connections still have an implicit pipesize specified
944 * by the global tcp_sendspace. In the absence of a reliable
945 * way to calculate the pipesize, it will have to do.
947 i = tp->snd_ssthresh;
948 if (rt->rt_rmx.rmx_sendpipe != 0)
949 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
951 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
952 if (dosavessthresh ||
953 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
954 (rt->rt_rmx.rmx_ssthresh != 0))) {
956 * convert the limit from user data bytes to
957 * packets then to packet data bytes.
959 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
964 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
965 sizeof(struct tcpiphdr));
966 if (rt->rt_rmx.rmx_ssthresh)
967 rt->rt_rmx.rmx_ssthresh =
968 (rt->rt_rmx.rmx_ssthresh + i) / 2;
970 rt->rt_rmx.rmx_ssthresh = i;
971 tcpstat.tcps_cachedssthresh++;
976 /* free the reassembly queue, if any */
977 while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
978 LIST_REMOVE(q, tqe_q);
981 atomic_add_int(&tcp_reass_qsize, -1);
983 /* throw away SACK blocks in scoreboard*/
985 tcp_sack_cleanup(&tp->scb);
987 inp->inp_ppcb = NULL;
988 soisdisconnected(so);
989 /* note: pcb detached later on */
991 tcp_destroy_timermsg(tp);
993 if (tp->t_flags & TF_LISTEN)
994 syncache_destroy(tp);
998 * pcbdetach removes any wildcard hash entry on the current CPU.
1007 tcpstat.tcps_closed++;
1011 static __inline void
1012 tcp_drain_oncpu(struct inpcbhead *head)
1014 struct inpcb *marker;
1017 struct tseg_qent *te;
1020 * Allows us to block while running the list
1022 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1023 marker->inp_flags |= INP_PLACEMARKER;
1024 LIST_INSERT_HEAD(head, marker, inp_list);
1026 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) {
1027 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1028 (tcpb = intotcpcb(inpb)) != NULL &&
1029 (te = LIST_FIRST(&tcpb->t_segq)) != NULL) {
1030 LIST_REMOVE(te, tqe_q);
1033 atomic_add_int(&tcp_reass_qsize, -1);
1036 LIST_REMOVE(marker, inp_list);
1037 LIST_INSERT_AFTER(inpb, marker, inp_list);
1040 LIST_REMOVE(marker, inp_list);
1041 kfree(marker, M_TEMP);
1045 struct netmsg_tcp_drain {
1046 struct netmsg_base base;
1047 struct inpcbhead *nm_head;
1051 tcp_drain_handler(netmsg_t msg)
1053 struct netmsg_tcp_drain *nm = (void *)msg;
1055 tcp_drain_oncpu(nm->nm_head);
1056 lwkt_replymsg(&nm->base.lmsg, 0);
1071 * Walk the tcpbs, if existing, and flush the reassembly queue,
1072 * if there is one...
1073 * XXX: The "Net/3" implementation doesn't imply that the TCP
1074 * reassembly queue should be flushed, but in a situation
1075 * where we're really low on mbufs, this is potentially
1079 for (cpu = 0; cpu < ncpus2; cpu++) {
1080 struct netmsg_tcp_drain *nm;
1082 if (cpu == mycpu->gd_cpuid) {
1083 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead);
1085 nm = kmalloc(sizeof(struct netmsg_tcp_drain),
1086 M_LWKTMSG, M_NOWAIT);
1089 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1090 0, tcp_drain_handler);
1091 nm->nm_head = &tcbinfo[cpu].pcblisthead;
1092 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg);
1096 tcp_drain_oncpu(&tcbinfo[0].pcblisthead);
1101 * Notify a tcp user of an asynchronous error;
1102 * store error as soft error, but wake up user
1103 * (for now, won't do anything until can select for soft error).
1105 * Do not wake up user since there currently is no mechanism for
1106 * reporting soft errors (yet - a kqueue filter may be added).
1109 tcp_notify(struct inpcb *inp, int error)
1111 struct tcpcb *tp = intotcpcb(inp);
1114 * Ignore some errors if we are hooked up.
1115 * If connection hasn't completed, has retransmitted several times,
1116 * and receives a second error, give up now. This is better
1117 * than waiting a long time to establish a connection that
1118 * can never complete.
1120 if (tp->t_state == TCPS_ESTABLISHED &&
1121 (error == EHOSTUNREACH || error == ENETUNREACH ||
1122 error == EHOSTDOWN)) {
1124 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1126 tcp_drop(tp, error);
1128 tp->t_softerror = error;
1130 wakeup(&so->so_timeo);
1137 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1140 struct inpcb *marker;
1149 * The process of preparing the TCB list is too time-consuming and
1150 * resource-intensive to repeat twice on every request.
1152 if (req->oldptr == NULL) {
1153 for (ccpu = 0; ccpu < ncpus; ++ccpu) {
1154 gd = globaldata_find(ccpu);
1155 n += tcbinfo[gd->gd_cpuid].ipi_count;
1157 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1161 if (req->newptr != NULL)
1164 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1165 marker->inp_flags |= INP_PLACEMARKER;
1168 * OK, now we're committed to doing something. Run the inpcb list
1169 * for each cpu in the system and construct the output. Use a
1170 * list placemarker to deal with list changes occuring during
1171 * copyout blockages (but otherwise depend on being on the correct
1172 * cpu to avoid races).
1174 origcpu = mycpu->gd_cpuid;
1175 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) {
1181 cpu_id = (origcpu + ccpu) % ncpus;
1182 if ((smp_active_mask & CPUMASK(cpu_id)) == 0)
1184 rgd = globaldata_find(cpu_id);
1185 lwkt_setcpu_self(rgd);
1187 n = tcbinfo[cpu_id].ipi_count;
1189 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list);
1191 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1193 * process a snapshot of pcbs, ignoring placemarkers
1194 * and using our own to allow SYSCTL_OUT to block.
1196 LIST_REMOVE(marker, inp_list);
1197 LIST_INSERT_AFTER(inp, marker, inp_list);
1199 if (inp->inp_flags & INP_PLACEMARKER)
1201 if (prison_xinpcb(req->td, inp))
1204 xt.xt_len = sizeof xt;
1205 bcopy(inp, &xt.xt_inp, sizeof *inp);
1206 inp_ppcb = inp->inp_ppcb;
1207 if (inp_ppcb != NULL)
1208 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1210 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1211 if (inp->inp_socket)
1212 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1213 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1217 LIST_REMOVE(marker, inp_list);
1218 if (error == 0 && i < n) {
1219 bzero(&xt, sizeof xt);
1220 xt.xt_len = sizeof xt;
1222 error = SYSCTL_OUT(req, &xt, sizeof xt);
1231 * Make sure we are on the same cpu we were on originally, since
1232 * higher level callers expect this. Also don't pollute caches with
1233 * migrated userland data by (eventually) returning to userland
1234 * on a different cpu.
1236 lwkt_setcpu_self(globaldata_find(origcpu));
1237 kfree(marker, M_TEMP);
1241 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1242 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1245 tcp_getcred(SYSCTL_HANDLER_ARGS)
1247 struct sockaddr_in addrs[2];
1252 error = priv_check(req->td, PRIV_ROOT);
1255 error = SYSCTL_IN(req, addrs, sizeof addrs);
1259 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1260 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1261 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1262 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1263 if (inp == NULL || inp->inp_socket == NULL) {
1267 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1273 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1274 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1278 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1280 struct sockaddr_in6 addrs[2];
1283 boolean_t mapped = FALSE;
1285 error = priv_check(req->td, PRIV_ROOT);
1288 error = SYSCTL_IN(req, addrs, sizeof addrs);
1291 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1292 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1299 inp = in_pcblookup_hash(&tcbinfo[0],
1300 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1302 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1306 inp = in6_pcblookup_hash(&tcbinfo[0],
1307 &addrs[1].sin6_addr, addrs[1].sin6_port,
1308 &addrs[0].sin6_addr, addrs[0].sin6_port,
1311 if (inp == NULL || inp->inp_socket == NULL) {
1315 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1321 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1323 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1326 struct netmsg_tcp_notify {
1327 struct netmsg_base base;
1328 void (*nm_notify)(struct inpcb *, int);
1329 struct in_addr nm_faddr;
1334 tcp_notifyall_oncpu(netmsg_t msg)
1336 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1339 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr,
1340 nm->nm_arg, nm->nm_notify);
1342 nextcpu = mycpuid + 1;
1343 if (nextcpu < ncpus2)
1344 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
1346 lwkt_replymsg(&nm->base.lmsg, 0);
1350 tcp_ctlinput(netmsg_t msg)
1352 int cmd = msg->ctlinput.nm_cmd;
1353 struct sockaddr *sa = msg->ctlinput.nm_arg;
1354 struct ip *ip = msg->ctlinput.nm_extra;
1356 struct in_addr faddr;
1359 void (*notify)(struct inpcb *, int) = tcp_notify;
1363 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1367 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1368 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1371 arg = inetctlerrmap[cmd];
1372 if (cmd == PRC_QUENCH) {
1373 notify = tcp_quench;
1374 } else if (icmp_may_rst &&
1375 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1376 cmd == PRC_UNREACH_PORT ||
1377 cmd == PRC_TIMXCEED_INTRANS) &&
1379 notify = tcp_drop_syn_sent;
1380 } else if (cmd == PRC_MSGSIZE) {
1381 struct icmp *icmp = (struct icmp *)
1382 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1384 arg = ntohs(icmp->icmp_nextmtu);
1385 notify = tcp_mtudisc;
1386 } else if (PRC_IS_REDIRECT(cmd)) {
1388 notify = in_rtchange;
1389 } else if (cmd == PRC_HOSTDEAD) {
1395 th = (struct tcphdr *)((caddr_t)ip +
1396 (IP_VHL_HL(ip->ip_vhl) << 2));
1397 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
1398 ip->ip_src.s_addr, th->th_sport);
1399 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
1400 ip->ip_src, th->th_sport, 0, NULL);
1401 if ((inp != NULL) && (inp->inp_socket != NULL)) {
1402 icmpseq = htonl(th->th_seq);
1403 tp = intotcpcb(inp);
1404 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1405 SEQ_LT(icmpseq, tp->snd_max))
1406 (*notify)(inp, arg);
1408 struct in_conninfo inc;
1410 inc.inc_fport = th->th_dport;
1411 inc.inc_lport = th->th_sport;
1412 inc.inc_faddr = faddr;
1413 inc.inc_laddr = ip->ip_src;
1417 syncache_unreach(&inc, th);
1421 struct netmsg_tcp_notify *nm;
1423 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
1424 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1425 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1426 0, tcp_notifyall_oncpu);
1427 nm->nm_faddr = faddr;
1429 nm->nm_notify = notify;
1431 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg);
1434 lwkt_replymsg(&msg->lmsg, 0);
1440 tcp6_ctlinput(netmsg_t msg)
1442 int cmd = msg->ctlinput.nm_cmd;
1443 struct sockaddr *sa = msg->ctlinput.nm_arg;
1444 void *d = msg->ctlinput.nm_extra;
1446 void (*notify) (struct inpcb *, int) = tcp_notify;
1447 struct ip6_hdr *ip6;
1449 struct ip6ctlparam *ip6cp = NULL;
1450 const struct sockaddr_in6 *sa6_src = NULL;
1452 struct tcp_portonly {
1458 if (sa->sa_family != AF_INET6 ||
1459 sa->sa_len != sizeof(struct sockaddr_in6)) {
1464 if (cmd == PRC_QUENCH)
1465 notify = tcp_quench;
1466 else if (cmd == PRC_MSGSIZE) {
1467 struct ip6ctlparam *ip6cp = d;
1468 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1470 arg = ntohl(icmp6->icmp6_mtu);
1471 notify = tcp_mtudisc;
1472 } else if (!PRC_IS_REDIRECT(cmd) &&
1473 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1477 /* if the parameter is from icmp6, decode it. */
1479 ip6cp = (struct ip6ctlparam *)d;
1481 ip6 = ip6cp->ip6c_ip6;
1482 off = ip6cp->ip6c_off;
1483 sa6_src = ip6cp->ip6c_src;
1487 off = 0; /* fool gcc */
1492 struct in_conninfo inc;
1494 * XXX: We assume that when IPV6 is non NULL,
1495 * M and OFF are valid.
1498 /* check if we can safely examine src and dst ports */
1499 if (m->m_pkthdr.len < off + sizeof *thp)
1502 bzero(&th, sizeof th);
1503 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
1505 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport,
1506 (struct sockaddr *)ip6cp->ip6c_src,
1507 th.th_sport, cmd, arg, notify);
1509 inc.inc_fport = th.th_dport;
1510 inc.inc_lport = th.th_sport;
1511 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1512 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1514 syncache_unreach(&inc, &th);
1516 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0,
1517 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1520 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1526 * Following is where TCP initial sequence number generation occurs.
1528 * There are two places where we must use initial sequence numbers:
1529 * 1. In SYN-ACK packets.
1530 * 2. In SYN packets.
1532 * All ISNs for SYN-ACK packets are generated by the syncache. See
1533 * tcp_syncache.c for details.
1535 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1536 * depends on this property. In addition, these ISNs should be
1537 * unguessable so as to prevent connection hijacking. To satisfy
1538 * the requirements of this situation, the algorithm outlined in
1539 * RFC 1948 is used to generate sequence numbers.
1541 * Implementation details:
1543 * Time is based off the system timer, and is corrected so that it
1544 * increases by one megabyte per second. This allows for proper
1545 * recycling on high speed LANs while still leaving over an hour
1548 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1549 * between seeding of isn_secret. This is normally set to zero,
1550 * as reseeding should not be necessary.
1554 #define ISN_BYTES_PER_SECOND 1048576
1556 u_char isn_secret[32];
1557 int isn_last_reseed;
1561 tcp_new_isn(struct tcpcb *tp)
1563 u_int32_t md5_buffer[4];
1566 /* Seed if this is the first use, reseed if requested. */
1567 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1568 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1570 read_random_unlimited(&isn_secret, sizeof isn_secret);
1571 isn_last_reseed = ticks;
1574 /* Compute the md5 hash and return the ISN. */
1576 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1577 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
1579 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
1580 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1581 sizeof(struct in6_addr));
1582 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1583 sizeof(struct in6_addr));
1587 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1588 sizeof(struct in_addr));
1589 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1590 sizeof(struct in_addr));
1592 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1593 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1594 new_isn = (tcp_seq) md5_buffer[0];
1595 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
1600 * When a source quench is received, close congestion window
1601 * to one segment. We will gradually open it again as we proceed.
1604 tcp_quench(struct inpcb *inp, int error)
1606 struct tcpcb *tp = intotcpcb(inp);
1609 tp->snd_cwnd = tp->t_maxseg;
1615 * When a specific ICMP unreachable message is received and the
1616 * connection state is SYN-SENT, drop the connection. This behavior
1617 * is controlled by the icmp_may_rst sysctl.
1620 tcp_drop_syn_sent(struct inpcb *inp, int error)
1622 struct tcpcb *tp = intotcpcb(inp);
1624 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
1625 tcp_drop(tp, error);
1629 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1630 * based on the new value in the route. Also nudge TCP to send something,
1631 * since we know the packet we just sent was dropped.
1632 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1635 tcp_mtudisc(struct inpcb *inp, int mtu)
1637 struct tcpcb *tp = intotcpcb(inp);
1639 struct socket *so = inp->inp_socket;
1642 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1644 const boolean_t isipv6 = FALSE;
1651 * If no MTU is provided in the ICMP message, use the
1652 * next lower likely value, as specified in RFC 1191.
1657 oldmtu = tp->t_maxopd +
1659 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1660 sizeof(struct tcpiphdr));
1661 mtu = ip_next_mtu(oldmtu, 0);
1665 rt = tcp_rtlookup6(&inp->inp_inc);
1667 rt = tcp_rtlookup(&inp->inp_inc);
1669 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1670 mtu = rt->rt_rmx.rmx_mtu;
1674 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1675 sizeof(struct tcpiphdr));
1678 * XXX - The following conditional probably violates the TCP
1679 * spec. The problem is that, since we don't know the
1680 * other end's MSS, we are supposed to use a conservative
1681 * default. But, if we do that, then MTU discovery will
1682 * never actually take place, because the conservative
1683 * default is much less than the MTUs typically seen
1684 * on the Internet today. For the moment, we'll sweep
1685 * this under the carpet.
1687 * The conservative default might not actually be a problem
1688 * if the only case this occurs is when sending an initial
1689 * SYN with options and data to a host we've never talked
1690 * to before. Then, they will reply with an MSS value which
1691 * will get recorded and the new parameters should get
1692 * recomputed. For Further Study.
1694 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1695 maxopd = rt->rt_rmx.rmx_mssopt;
1699 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1700 sizeof(struct tcpiphdr));
1702 if (tp->t_maxopd <= maxopd)
1704 tp->t_maxopd = maxopd;
1707 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1708 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1709 mss -= TCPOLEN_TSTAMP_APPA;
1711 /* round down to multiple of MCLBYTES */
1712 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1714 mss &= ~(MCLBYTES - 1);
1717 mss = (mss / MCLBYTES) * MCLBYTES;
1720 if (so->so_snd.ssb_hiwat < mss)
1721 mss = so->so_snd.ssb_hiwat;
1725 tp->snd_nxt = tp->snd_una;
1727 tcpstat.tcps_mturesent++;
1731 * Look-up the routing entry to the peer of this inpcb. If no route
1732 * is found and it cannot be allocated the return NULL. This routine
1733 * is called by TCP routines that access the rmx structure and by tcp_mss
1734 * to get the interface MTU.
1737 tcp_rtlookup(struct in_conninfo *inc)
1739 struct route *ro = &inc->inc_route;
1741 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1742 /* No route yet, so try to acquire one */
1743 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1745 * unused portions of the structure MUST be zero'd
1746 * out because rtalloc() treats it as opaque data
1748 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1749 ro->ro_dst.sa_family = AF_INET;
1750 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1751 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1761 tcp_rtlookup6(struct in_conninfo *inc)
1763 struct route_in6 *ro6 = &inc->inc6_route;
1765 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1766 /* No route yet, so try to acquire one */
1767 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1769 * unused portions of the structure MUST be zero'd
1770 * out because rtalloc() treats it as opaque data
1772 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1773 ro6->ro_dst.sin6_family = AF_INET6;
1774 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1775 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1776 rtalloc((struct route *)ro6);
1779 return (ro6->ro_rt);
1784 /* compute ESP/AH header size for TCP, including outer IP header. */
1786 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1794 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1796 MGETHDR(m, MB_DONTWAIT, MT_DATA);
1801 if (inp->inp_vflag & INP_IPV6) {
1802 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1804 th = (struct tcphdr *)(ip6 + 1);
1805 m->m_pkthdr.len = m->m_len =
1806 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1807 tcp_fillheaders(tp, ip6, th);
1808 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1812 ip = mtod(m, struct ip *);
1813 th = (struct tcphdr *)(ip + 1);
1814 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1815 tcp_fillheaders(tp, ip, th);
1816 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1825 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1827 * This code attempts to calculate the bandwidth-delay product as a
1828 * means of determining the optimal window size to maximize bandwidth,
1829 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1830 * routers. This code also does a fairly good job keeping RTTs in check
1831 * across slow links like modems. We implement an algorithm which is very
1832 * similar (but not meant to be) TCP/Vegas. The code operates on the
1833 * transmitter side of a TCP connection and so only effects the transmit
1834 * side of the connection.
1836 * BACKGROUND: TCP makes no provision for the management of buffer space
1837 * at the end points or at the intermediate routers and switches. A TCP
1838 * stream, whether using NewReno or not, will eventually buffer as
1839 * many packets as it is able and the only reason this typically works is
1840 * due to the fairly small default buffers made available for a connection
1841 * (typicaly 16K or 32K). As machines use larger windows and/or window
1842 * scaling it is now fairly easy for even a single TCP connection to blow-out
1843 * all available buffer space not only on the local interface, but on
1844 * intermediate routers and switches as well. NewReno makes a misguided
1845 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1846 * then backing off, then steadily increasing the window again until another
1847 * failure occurs, ad-infinitum. This results in terrible oscillation that
1848 * is only made worse as network loads increase and the idea of intentionally
1849 * blowing out network buffers is, frankly, a terrible way to manage network
1852 * It is far better to limit the transmit window prior to the failure
1853 * condition being achieved. There are two general ways to do this: First
1854 * you can 'scan' through different transmit window sizes and locate the
1855 * point where the RTT stops increasing, indicating that you have filled the
1856 * pipe, then scan backwards until you note that RTT stops decreasing, then
1857 * repeat ad-infinitum. This method works in principle but has severe
1858 * implementation issues due to RTT variances, timer granularity, and
1859 * instability in the algorithm which can lead to many false positives and
1860 * create oscillations as well as interact badly with other TCP streams
1861 * implementing the same algorithm.
1863 * The second method is to limit the window to the bandwidth delay product
1864 * of the link. This is the method we implement. RTT variances and our
1865 * own manipulation of the congestion window, bwnd, can potentially
1866 * destabilize the algorithm. For this reason we have to stabilize the
1867 * elements used to calculate the window. We do this by using the minimum
1868 * observed RTT, the long term average of the observed bandwidth, and
1869 * by adding two segments worth of slop. It isn't perfect but it is able
1870 * to react to changing conditions and gives us a very stable basis on
1871 * which to extend the algorithm.
1874 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1882 * If inflight_enable is disabled in the middle of a tcp connection,
1883 * make sure snd_bwnd is effectively disabled.
1885 if (!tcp_inflight_enable) {
1886 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1887 tp->snd_bandwidth = 0;
1892 * Validate the delta time. If a connection is new or has been idle
1893 * a long time we have to reset the bandwidth calculator.
1896 delta_ticks = save_ticks - tp->t_bw_rtttime;
1897 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1898 tp->t_bw_rtttime = ticks;
1899 tp->t_bw_rtseq = ack_seq;
1900 if (tp->snd_bandwidth == 0)
1901 tp->snd_bandwidth = tcp_inflight_min;
1904 if (delta_ticks == 0)
1908 * Sanity check, plus ignore pure window update acks.
1910 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1914 * Figure out the bandwidth. Due to the tick granularity this
1915 * is a very rough number and it MUST be averaged over a fairly
1916 * long period of time. XXX we need to take into account a link
1917 * that is not using all available bandwidth, but for now our
1918 * slop will ramp us up if this case occurs and the bandwidth later
1921 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
1922 tp->t_bw_rtttime = save_ticks;
1923 tp->t_bw_rtseq = ack_seq;
1924 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
1926 tp->snd_bandwidth = bw;
1929 * Calculate the semi-static bandwidth delay product, plus two maximal
1930 * segments. The additional slop puts us squarely in the sweet
1931 * spot and also handles the bandwidth run-up case. Without the
1932 * slop we could be locking ourselves into a lower bandwidth.
1934 * Situations Handled:
1935 * (1) Prevents over-queueing of packets on LANs, especially on
1936 * high speed LANs, allowing larger TCP buffers to be
1937 * specified, and also does a good job preventing
1938 * over-queueing of packets over choke points like modems
1939 * (at least for the transmit side).
1941 * (2) Is able to handle changing network loads (bandwidth
1942 * drops so bwnd drops, bandwidth increases so bwnd
1945 * (3) Theoretically should stabilize in the face of multiple
1946 * connections implementing the same algorithm (this may need
1949 * (4) Stability value (defaults to 20 = 2 maximal packets) can
1950 * be adjusted with a sysctl but typically only needs to be on
1951 * very slow connections. A value no smaller then 5 should
1952 * be used, but only reduce this default if you have no other
1956 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
1957 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
1958 tcp_inflight_stab * (int)tp->t_maxseg / 10;
1961 if (tcp_inflight_debug > 0) {
1963 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
1965 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
1966 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd);
1969 if ((long)bwnd < tcp_inflight_min)
1970 bwnd = tcp_inflight_min;
1971 if (bwnd > tcp_inflight_max)
1972 bwnd = tcp_inflight_max;
1973 if ((long)bwnd < tp->t_maxseg * 2)
1974 bwnd = tp->t_maxseg * 2;
1975 tp->snd_bwnd = bwnd;
1979 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
1982 struct inpcb *inp = tp->t_inpcb;
1984 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
1986 const boolean_t isipv6 = FALSE;
1990 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
1991 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
1992 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
1993 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
1996 rt = tcp_rtlookup6(&inp->inp_inc);
1998 rt = tcp_rtlookup(&inp->inp_inc);
2000 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2001 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2002 *maxsegs = tcp_iw_maxsegs;
2003 *capsegs = tcp_iw_capsegs;
2006 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2007 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2011 tcp_initial_window(struct tcpcb *tp)
2013 if (tcp_do_rfc3390) {
2016 * "If the SYN or SYN/ACK is lost, the initial window
2017 * used by a sender after a correctly transmitted SYN
2018 * MUST be one segment consisting of MSS bytes."
2020 * However, we do something a little bit more aggressive
2021 * then RFC3390 here:
2022 * - Only if time spent in the SYN or SYN|ACK retransmition
2023 * >= 3 seconds, the IW is reduced. We do this mainly
2024 * because when RFC3390 is published, the initial RTO is
2025 * still 3 seconds (the threshold we test here), while
2026 * after RFC6298, the initial RTO is 1 second. This
2027 * behaviour probably still falls within the spirit of
2029 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2030 * Mainly to avoid sender and receiver deadlock until
2031 * delayed ACK timer expires. And even RFC2581 does not
2032 * try to reduce IW upon SYN or SYN|ACK retransmition
2036 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2038 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2039 return (2 * tp->t_maxseg);
2041 u_long maxsegs, capsegs;
2043 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2044 return min(maxsegs * tp->t_maxseg,
2045 max(2 * tp->t_maxseg, capsegs * 1460));
2049 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2051 * Mainly to avoid sender and receiver deadlock
2052 * until delayed ACK timer expires.
2054 return (2 * tp->t_maxseg);
2058 #ifdef TCP_SIGNATURE
2060 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2062 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2063 * When called from tcp_input(), we can be sure that th_sum has been
2064 * zeroed out and verified already.
2066 * Return 0 if successful, otherwise return -1.
2068 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2069 * search with the destination IP address, and a 'magic SPI' to be
2070 * determined by the application. This is hardcoded elsewhere to 1179
2071 * right now. Another branch of this code exists which uses the SPD to
2072 * specify per-application flows but it is unstable.
2075 tcpsignature_compute(
2076 struct mbuf *m, /* mbuf chain */
2077 int len, /* length of TCP data */
2078 int optlen, /* length of TCP options */
2079 u_char *buf, /* storage for MD5 digest */
2080 u_int direction) /* direction of flow */
2082 struct ippseudo ippseudo;
2086 struct ipovly *ipovly;
2087 struct secasvar *sav;
2090 struct ip6_hdr *ip6;
2091 struct in6_addr in6;
2097 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2098 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2100 * Extract the destination from the IP header in the mbuf.
2102 ip = mtod(m, struct ip *);
2104 ip6 = NULL; /* Make the compiler happy. */
2107 * Look up an SADB entry which matches the address found in
2110 switch (IP_VHL_V(ip->ip_vhl)) {
2112 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2113 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2116 case (IPV6_VERSION >> 4):
2117 ip6 = mtod(m, struct ip6_hdr *);
2118 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2119 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2128 kprintf("%s: SADB lookup failed\n", __func__);
2134 * Step 1: Update MD5 hash with IP pseudo-header.
2136 * XXX The ippseudo header MUST be digested in network byte order,
2137 * or else we'll fail the regression test. Assume all fields we've
2138 * been doing arithmetic on have been in host byte order.
2139 * XXX One cannot depend on ipovly->ih_len here. When called from
2140 * tcp_output(), the underlying ip_len member has not yet been set.
2142 switch (IP_VHL_V(ip->ip_vhl)) {
2144 ipovly = (struct ipovly *)ip;
2145 ippseudo.ippseudo_src = ipovly->ih_src;
2146 ippseudo.ippseudo_dst = ipovly->ih_dst;
2147 ippseudo.ippseudo_pad = 0;
2148 ippseudo.ippseudo_p = IPPROTO_TCP;
2149 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2150 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2151 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2152 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2156 * RFC 2385, 2.0 Proposal
2157 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2158 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2159 * extended next header value (to form 32 bits), and 32-bit segment
2161 * Note: Upper-Layer Packet Length comes before Next Header.
2163 case (IPV6_VERSION >> 4):
2165 in6_clearscope(&in6);
2166 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2168 in6_clearscope(&in6);
2169 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2170 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2171 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2173 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2174 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2175 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2177 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2178 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2179 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2188 * Step 2: Update MD5 hash with TCP header, excluding options.
2189 * The TCP checksum must be set to zero.
2191 savecsum = th->th_sum;
2193 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2194 th->th_sum = savecsum;
2196 * Step 3: Update MD5 hash with TCP segment data.
2197 * Use m_apply() to avoid an early m_pullup().
2200 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2202 * Step 4: Update MD5 hash with shared secret.
2204 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2205 MD5Final(buf, &ctx);
2206 key_sa_recordxfer(sav, m);
2212 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2215 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2218 #endif /* TCP_SIGNATURE */