2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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62 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
63 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $
66 #include "opt_compat.h"
68 #include "opt_inet6.h"
69 #include "opt_ipsec.h"
70 #include "opt_tcpdebug.h"
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/callout.h>
75 #include <sys/kernel.h>
76 #include <sys/sysctl.h>
77 #include <sys/malloc.h>
78 #include <sys/mpipe.h>
81 #include <sys/domain.h>
85 #include <sys/socket.h>
86 #include <sys/socketops.h>
87 #include <sys/socketvar.h>
88 #include <sys/protosw.h>
89 #include <sys/random.h>
90 #include <sys/in_cksum.h>
93 #include <net/route.h>
95 #include <net/netisr2.h>
98 #include <netinet/in.h>
99 #include <netinet/in_systm.h>
100 #include <netinet/ip.h>
101 #include <netinet/ip6.h>
102 #include <netinet/in_pcb.h>
103 #include <netinet6/in6_pcb.h>
104 #include <netinet/in_var.h>
105 #include <netinet/ip_var.h>
106 #include <netinet6/ip6_var.h>
107 #include <netinet/ip_icmp.h>
109 #include <netinet/icmp6.h>
111 #include <netinet/tcp.h>
112 #include <netinet/tcp_fsm.h>
113 #include <netinet/tcp_seq.h>
114 #include <netinet/tcp_timer.h>
115 #include <netinet/tcp_timer2.h>
116 #include <netinet/tcp_var.h>
117 #include <netinet6/tcp6_var.h>
118 #include <netinet/tcpip.h>
120 #include <netinet/tcp_debug.h>
122 #include <netinet6/ip6protosw.h>
125 #include <netinet6/ipsec.h>
126 #include <netproto/key/key.h>
128 #include <netinet6/ipsec6.h>
133 #include <netproto/ipsec/ipsec.h>
135 #include <netproto/ipsec/ipsec6.h>
141 #include <machine/smp.h>
143 #include <sys/msgport2.h>
144 #include <sys/mplock2.h>
145 #include <net/netmsg2.h>
147 #if !defined(KTR_TCP)
148 #define KTR_TCP KTR_ALL
151 KTR_INFO_MASTER(tcp);
152 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0);
153 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0);
154 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
155 #define logtcp(name) KTR_LOG(tcp_ ## name)
158 #define TCP_IW_MAXSEGS_DFLT 4
159 #define TCP_IW_CAPSEGS_DFLT 3
161 struct inpcbinfo tcbinfo[MAXCPU];
162 struct tcpcbackqhead tcpcbackq[MAXCPU];
164 int tcp_mssdflt = TCP_MSS;
165 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
166 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size");
169 int tcp_v6mssdflt = TCP6_MSS;
170 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW,
171 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6");
175 * Minimum MSS we accept and use. This prevents DoS attacks where
176 * we are forced to a ridiculous low MSS like 20 and send hundreds
177 * of packets instead of one. The effect scales with the available
178 * bandwidth and quickly saturates the CPU and network interface
179 * with packet generation and sending. Set to zero to disable MINMSS
180 * checking. This setting prevents us from sending too small packets.
182 int tcp_minmss = TCP_MINMSS;
183 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
184 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
187 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
188 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
189 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time");
192 int tcp_do_rfc1323 = 1;
193 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
194 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
196 static int tcp_tcbhashsize = 0;
197 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
198 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable");
200 static int do_tcpdrain = 1;
201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
202 "Enable tcp_drain routine for extra help when low on mbufs");
204 static int icmp_may_rst = 1;
205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
206 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
208 static int tcp_isn_reseed_interval = 0;
209 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
210 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
213 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on
214 * by default, but with generous values which should allow maximal
215 * bandwidth. In particular, the slop defaults to 50 (5 packets).
217 * The reason for doing this is that the limiter is the only mechanism we
218 * have which seems to do a really good job preventing receiver RX rings
219 * on network interfaces from getting blown out. Even though GigE/10GigE
220 * is supposed to flow control it looks like either it doesn't actually
221 * do it or Open Source drivers do not properly enable it.
223 * People using the limiter to reduce bottlenecks on slower WAN connections
224 * should set the slop to 20 (2 packets).
226 static int tcp_inflight_enable = 1;
227 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
228 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
230 static int tcp_inflight_debug = 0;
231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
232 &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
234 static int tcp_inflight_min = 6144;
235 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
236 &tcp_inflight_min, 0, "Lower bound for TCP inflight window");
238 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
239 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
240 &tcp_inflight_max, 0, "Upper bound for TCP inflight window");
242 static int tcp_inflight_stab = 50;
243 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
244 &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)");
246 static int tcp_inflight_adjrtt = 2;
247 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW,
248 &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)");
250 static int tcp_do_rfc3390 = 1;
251 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
253 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
255 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
256 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
257 &tcp_iw_maxsegs, 0, "TCP IW segments max");
259 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
260 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
261 &tcp_iw_capsegs, 0, "TCP IW segments");
263 int tcp_low_rtobase = 1;
264 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW,
265 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)");
267 static int tcp_do_ncr = 1;
268 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW,
269 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)");
271 int tcp_ncr_rxtthresh_max = 16;
272 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW,
273 &tcp_ncr_rxtthresh_max, 0,
274 "Non-Congestion Robustness (RFC 4653), DupThresh upper limit");
276 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
277 static struct malloc_pipe tcptemp_mpipe;
279 static void tcp_willblock(void);
280 static void tcp_notify (struct inpcb *, int);
282 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign;
284 static struct netmsg_base tcp_drain_netmsg[MAXCPU];
285 static void tcp_drain_dispatch(netmsg_t nmsg);
288 sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
292 for (cpu = 0; cpu < ncpus2; ++cpu) {
293 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
294 sizeof(struct tcp_stats))))
296 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
297 sizeof(struct tcp_stats))))
303 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
304 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
307 * Target size of TCP PCB hash tables. Must be a power of two.
309 * Note that this can be overridden by the kernel environment
310 * variable net.inet.tcp.tcbhashsize
313 #define TCBHASHSIZE 512
317 * This is the actual shape of what we allocate using the zone
318 * allocator. Doing it this way allows us to protect both structures
319 * using the same generation count, and also eliminates the overhead
320 * of allocating tcpcbs separately. By hiding the structure here,
321 * we avoid changing most of the rest of the code (although it needs
322 * to be changed, eventually, for greater efficiency).
325 #define ALIGNM1 (ALIGNMENT - 1)
329 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
332 struct tcp_callout inp_tp_rexmt;
333 struct tcp_callout inp_tp_persist;
334 struct tcp_callout inp_tp_keep;
335 struct tcp_callout inp_tp_2msl;
336 struct tcp_callout inp_tp_delack;
337 struct netmsg_tcp_timer inp_tp_timermsg;
338 struct netmsg_base inp_tp_sndmore;
349 struct inpcbportinfo *portinfo;
350 struct inpcbinfo *ticb;
351 int hashsize = TCBHASHSIZE;
355 * note: tcptemp is used for keepalives, and it is ok for an
356 * allocation to fail so do not specify MPF_INT.
358 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
359 25, -1, 0, NULL, NULL, NULL);
361 tcp_delacktime = TCPTV_DELACK;
362 tcp_keepinit = TCPTV_KEEP_INIT;
363 tcp_keepidle = TCPTV_KEEP_IDLE;
364 tcp_keepintvl = TCPTV_KEEPINTVL;
365 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
367 tcp_rexmit_min = TCPTV_MIN;
368 tcp_rexmit_slop = TCPTV_CPU_VAR;
370 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
371 if (!powerof2(hashsize)) {
372 kprintf("WARNING: TCB hash size not a power of 2\n");
373 hashsize = 512; /* safe default */
375 tcp_tcbhashsize = hashsize;
377 portinfo = kmalloc_cachealign(sizeof(*portinfo) * ncpus2, M_PCB,
380 for (cpu = 0; cpu < ncpus2; cpu++) {
381 ticb = &tcbinfo[cpu];
382 in_pcbinfo_init(ticb, cpu, FALSE);
383 ticb->hashbase = hashinit(hashsize, M_PCB,
385 in_pcbportinfo_init(&portinfo[cpu], hashsize, TRUE, cpu);
386 ticb->portinfo = portinfo;
387 ticb->portinfo_mask = ncpus2_mask;
388 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
389 &ticb->wildcardhashmask);
390 ticb->localgrphashbase = hashinit(hashsize, M_PCB,
391 &ticb->localgrphashmask);
392 ticb->ipi_size = sizeof(struct inp_tp);
393 TAILQ_INIT(&tcpcbackq[cpu]);
396 tcp_reass_maxseg = nmbclusters / 16;
397 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg);
400 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
402 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
404 if (max_protohdr < TCP_MINPROTOHDR)
405 max_protohdr = TCP_MINPROTOHDR;
406 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
408 #undef TCP_MINPROTOHDR
411 * Initialize TCP statistics counters for each CPU.
413 for (cpu = 0; cpu < ncpus2; ++cpu)
414 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
417 * Initialize netmsgs for TCP drain
419 for (cpu = 0; cpu < ncpus2; ++cpu) {
420 netmsg_init(&tcp_drain_netmsg[cpu], NULL, &netisr_adone_rport,
421 MSGF_PRIORITY, tcp_drain_dispatch);
425 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP);
432 int cpu = mycpu->gd_cpuid;
434 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) {
435 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
436 tp->t_flags &= ~TF_ONOUTPUTQ;
437 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq);
443 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
444 * tcp_template used to store this data in mbufs, but we now recopy it out
445 * of the tcpcb each time to conserve mbufs.
448 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso)
450 struct inpcb *inp = tp->t_inpcb;
451 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
454 if (inp->inp_vflag & INP_IPV6) {
457 ip6 = (struct ip6_hdr *)ip_ptr;
458 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
459 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
460 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
461 (IPV6_VERSION & IPV6_VERSION_MASK);
462 ip6->ip6_nxt = IPPROTO_TCP;
463 ip6->ip6_plen = sizeof(struct tcphdr);
464 ip6->ip6_src = inp->in6p_laddr;
465 ip6->ip6_dst = inp->in6p_faddr;
470 struct ip *ip = (struct ip *) ip_ptr;
473 ip->ip_vhl = IP_VHL_BORING;
480 ip->ip_p = IPPROTO_TCP;
481 ip->ip_src = inp->inp_laddr;
482 ip->ip_dst = inp->inp_faddr;
485 plen = htons(IPPROTO_TCP);
487 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP);
488 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
489 ip->ip_dst.s_addr, plen);
492 tcp_hdr->th_sport = inp->inp_lport;
493 tcp_hdr->th_dport = inp->inp_fport;
498 tcp_hdr->th_flags = 0;
504 * Create template to be used to send tcp packets on a connection.
505 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
506 * use for this function is in keepalives, which use tcp_respond.
509 tcp_maketemplate(struct tcpcb *tp)
513 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
515 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE);
520 tcp_freetemplate(struct tcptemp *tmp)
522 mpipe_free(&tcptemp_mpipe, tmp);
526 * Send a single message to the TCP at address specified by
527 * the given TCP/IP header. If m == NULL, then we make a copy
528 * of the tcpiphdr at ti and send directly to the addressed host.
529 * This is used to force keep alive messages out using the TCP
530 * template for a connection. If flags are given then we send
531 * a message back to the TCP which originated the * segment ti,
532 * and discard the mbuf containing it and any other attached mbufs.
534 * In any case the ack and sequence number of the transmitted
535 * segment are as specified by the parameters.
537 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
540 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
541 tcp_seq ack, tcp_seq seq, int flags)
545 struct route *ro = NULL;
547 struct ip *ip = ipgen;
550 struct route_in6 *ro6 = NULL;
551 struct route_in6 sro6;
552 struct ip6_hdr *ip6 = ipgen;
553 boolean_t use_tmpro = TRUE;
555 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
557 const boolean_t isipv6 = FALSE;
561 if (!(flags & TH_RST)) {
562 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv);
565 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
566 win = (long)TCP_MAXWIN << tp->rcv_scale;
569 * Don't use the route cache of a listen socket,
570 * it is not MPSAFE; use temporary route cache.
572 if (tp->t_state != TCPS_LISTEN) {
574 ro6 = &tp->t_inpcb->in6p_route;
576 ro = &tp->t_inpcb->inp_route;
583 bzero(ro6, sizeof *ro6);
586 bzero(ro, sizeof *ro);
590 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
594 m->m_data += max_linkhdr;
596 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
597 ip6 = mtod(m, struct ip6_hdr *);
598 nth = (struct tcphdr *)(ip6 + 1);
600 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
601 ip = mtod(m, struct ip *);
602 nth = (struct tcphdr *)(ip + 1);
604 bcopy(th, nth, sizeof(struct tcphdr));
609 m->m_data = (caddr_t)ipgen;
610 /* m_len is set later */
612 #define xchg(a, b, type) { type t; t = a; a = b; b = t; }
614 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
615 nth = (struct tcphdr *)(ip6 + 1);
617 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
618 nth = (struct tcphdr *)(ip + 1);
622 * this is usually a case when an extension header
623 * exists between the IPv6 header and the
626 nth->th_sport = th->th_sport;
627 nth->th_dport = th->th_dport;
629 xchg(nth->th_dport, nth->th_sport, n_short);
634 ip6->ip6_vfc = IPV6_VERSION;
635 ip6->ip6_nxt = IPPROTO_TCP;
636 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
637 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
639 tlen += sizeof(struct tcpiphdr);
641 ip->ip_ttl = ip_defttl;
644 m->m_pkthdr.len = tlen;
645 m->m_pkthdr.rcvif = NULL;
646 nth->th_seq = htonl(seq);
647 nth->th_ack = htonl(ack);
649 nth->th_off = sizeof(struct tcphdr) >> 2;
650 nth->th_flags = flags;
652 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
654 nth->th_win = htons((u_short)win);
658 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
659 sizeof(struct ip6_hdr),
660 tlen - sizeof(struct ip6_hdr));
661 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
662 (ro6 && ro6->ro_rt) ?
663 ro6->ro_rt->rt_ifp : NULL);
665 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
666 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
667 m->m_pkthdr.csum_flags = CSUM_TCP;
668 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
669 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr);
672 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
673 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
676 ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
677 tp ? tp->t_inpcb : NULL);
678 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
683 ipflags |= IP_DEBUGROUTE;
684 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
685 if ((ro == &sro) && (ro->ro_rt != NULL)) {
693 * Create a new TCP control block, making an
694 * empty reassembly queue and hooking it to the argument
695 * protocol control block. The `inp' parameter must have
696 * come from the zone allocator set up in tcp_init().
699 tcp_newtcpcb(struct inpcb *inp)
704 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
706 const boolean_t isipv6 = FALSE;
709 it = (struct inp_tp *)inp;
711 bzero(tp, sizeof(struct tcpcb));
712 TAILQ_INIT(&tp->t_segq);
713 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
714 tp->t_rxtthresh = tcprexmtthresh;
716 /* Set up our timeouts. */
717 tp->tt_rexmt = &it->inp_tp_rexmt;
718 tp->tt_persist = &it->inp_tp_persist;
719 tp->tt_keep = &it->inp_tp_keep;
720 tp->tt_2msl = &it->inp_tp_2msl;
721 tp->tt_delack = &it->inp_tp_delack;
725 * Zero out timer message. We don't create it here,
726 * since the current CPU may not be the owner of this
729 tp->tt_msg = &it->inp_tp_timermsg;
730 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
732 tp->t_keepinit = tcp_keepinit;
733 tp->t_keepidle = tcp_keepidle;
734 tp->t_keepintvl = tcp_keepintvl;
735 tp->t_keepcnt = tcp_keepcnt;
736 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
739 tp->t_flags |= TF_NCR;
741 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP);
743 tp->t_inpcb = inp; /* XXX */
744 tp->t_state = TCPS_CLOSED;
746 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
747 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
748 * reasonable initial retransmit time.
750 tp->t_srtt = TCPTV_SRTTBASE;
752 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
753 tp->t_rttmin = tcp_rexmit_min;
754 tp->t_rxtcur = TCPTV_RTOBASE;
755 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
756 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
757 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
758 tp->snd_last = ticks;
759 tp->t_rcvtime = ticks;
761 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
762 * because the socket may be bound to an IPv6 wildcard address,
763 * which may match an IPv4-mapped IPv6 address.
765 inp->inp_ip_ttl = ip_defttl;
767 tcp_sack_tcpcb_init(tp);
769 tp->tt_sndmore = &it->inp_tp_sndmore;
772 return (tp); /* XXX */
776 * Drop a TCP connection, reporting the specified error.
777 * If connection is synchronized, then send a RST to peer.
780 tcp_drop(struct tcpcb *tp, int error)
782 struct socket *so = tp->t_inpcb->inp_socket;
784 if (TCPS_HAVERCVDSYN(tp->t_state)) {
785 tp->t_state = TCPS_CLOSED;
787 tcpstat.tcps_drops++;
789 tcpstat.tcps_conndrops++;
790 if (error == ETIMEDOUT && tp->t_softerror)
791 error = tp->t_softerror;
792 so->so_error = error;
793 return (tcp_close(tp));
796 struct netmsg_listen_detach {
797 struct netmsg_base base;
799 struct tcpcb *nm_tp_inh;
803 tcp_listen_detach_handler(netmsg_t msg)
805 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
806 struct tcpcb *tp = nmsg->nm_tp;
807 int cpu = mycpuid, nextcpu;
809 if (tp->t_flags & TF_LISTEN)
810 syncache_destroy(tp, nmsg->nm_tp_inh);
812 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
815 if (nextcpu < ncpus2)
816 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg);
818 lwkt_replymsg(&nmsg->base.lmsg, 0);
822 * Close a TCP control block:
823 * discard all space held by the tcp
824 * discard internet protocol block
825 * wake up any sleepers
828 tcp_close(struct tcpcb *tp)
831 struct inpcb *inp = tp->t_inpcb;
832 struct inpcb *inp_inh = NULL;
833 struct tcpcb *tp_inh = NULL;
834 struct socket *so = inp->inp_socket;
836 boolean_t dosavessthresh;
838 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
839 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
841 const boolean_t isipv6 = FALSE;
844 if (tp->t_flags & TF_LISTEN) {
846 * Pending socket/syncache inheritance
848 * If this is a listen(2) socket, find another listen(2)
849 * socket in the same local group, which could inherit
850 * the syncache and sockets pending on the completion
851 * and incompletion queues.
854 * Currently the inheritance could only happen on the
855 * listen(2) sockets w/ SO_REUSEPORT set.
857 KASSERT(&curthread->td_msgport == netisr_cpuport(0),
858 ("listen socket close not in netisr0"));
859 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp);
861 tp_inh = intotcpcb(inp_inh);
865 * INP_WILDCARD indicates that listen(2) has been called on
866 * this socket. This implies:
867 * - A wildcard inp's hash is replicated for each protocol thread.
868 * - Syncache for this inp grows independently in each protocol
870 * - There is more than one cpu
872 * We have to chain a message to the rest of the protocol threads
873 * to cleanup the wildcard hash and the syncache. The cleanup
874 * in the current protocol thread is defered till the end of this
875 * function (syncache_destroy and in_pcbdetach).
878 * After cleanup the inp's hash and syncache entries, this inp will
879 * no longer be available to the rest of the protocol threads, so we
880 * are safe to whack the inp in the following code.
882 if ((inp->inp_flags & INP_WILDCARD) && ncpus2 > 1) {
883 struct netmsg_listen_detach nmsg;
885 KKASSERT(so->so_port == netisr_cpuport(0));
886 KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
887 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
889 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
890 MSGF_PRIORITY, tcp_listen_detach_handler);
892 nmsg.nm_tp_inh = tp_inh;
893 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0);
896 KKASSERT(tp->t_state != TCPS_TERMINATING);
897 tp->t_state = TCPS_TERMINATING;
900 * Make sure that all of our timers are stopped before we
901 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
902 * timers are never used. If timer message is never created
903 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
905 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
906 tcp_callout_stop(tp, tp->tt_rexmt);
907 tcp_callout_stop(tp, tp->tt_persist);
908 tcp_callout_stop(tp, tp->tt_keep);
909 tcp_callout_stop(tp, tp->tt_2msl);
910 tcp_callout_stop(tp, tp->tt_delack);
913 if (tp->t_flags & TF_ONOUTPUTQ) {
914 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
915 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
916 tp->t_flags &= ~TF_ONOUTPUTQ;
920 * If we got enough samples through the srtt filter,
921 * save the rtt and rttvar in the routing entry.
922 * 'Enough' is arbitrarily defined as the 16 samples.
923 * 16 samples is enough for the srtt filter to converge
924 * to within 5% of the correct value; fewer samples and
925 * we could save a very bogus rtt.
927 * Don't update the default route's characteristics and don't
928 * update anything that the user "locked".
930 if (tp->t_rttupdated >= 16) {
934 struct sockaddr_in6 *sin6;
936 if ((rt = inp->in6p_route.ro_rt) == NULL)
938 sin6 = (struct sockaddr_in6 *)rt_key(rt);
939 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
942 if ((rt = inp->inp_route.ro_rt) == NULL ||
943 ((struct sockaddr_in *)rt_key(rt))->
944 sin_addr.s_addr == INADDR_ANY)
947 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
948 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
949 if (rt->rt_rmx.rmx_rtt && i)
951 * filter this update to half the old & half
952 * the new values, converting scale.
953 * See route.h and tcp_var.h for a
954 * description of the scaling constants.
957 (rt->rt_rmx.rmx_rtt + i) / 2;
959 rt->rt_rmx.rmx_rtt = i;
960 tcpstat.tcps_cachedrtt++;
962 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
964 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
965 if (rt->rt_rmx.rmx_rttvar && i)
966 rt->rt_rmx.rmx_rttvar =
967 (rt->rt_rmx.rmx_rttvar + i) / 2;
969 rt->rt_rmx.rmx_rttvar = i;
970 tcpstat.tcps_cachedrttvar++;
973 * The old comment here said:
974 * update the pipelimit (ssthresh) if it has been updated
975 * already or if a pipesize was specified & the threshhold
976 * got below half the pipesize. I.e., wait for bad news
977 * before we start updating, then update on both good
980 * But we want to save the ssthresh even if no pipesize is
981 * specified explicitly in the route, because such
982 * connections still have an implicit pipesize specified
983 * by the global tcp_sendspace. In the absence of a reliable
984 * way to calculate the pipesize, it will have to do.
986 i = tp->snd_ssthresh;
987 if (rt->rt_rmx.rmx_sendpipe != 0)
988 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
990 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
991 if (dosavessthresh ||
992 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
993 (rt->rt_rmx.rmx_ssthresh != 0))) {
995 * convert the limit from user data bytes to
996 * packets then to packet data bytes.
998 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
1003 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1004 sizeof(struct tcpiphdr));
1005 if (rt->rt_rmx.rmx_ssthresh)
1006 rt->rt_rmx.rmx_ssthresh =
1007 (rt->rt_rmx.rmx_ssthresh + i) / 2;
1009 rt->rt_rmx.rmx_ssthresh = i;
1010 tcpstat.tcps_cachedssthresh++;
1015 /* free the reassembly queue, if any */
1016 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) {
1017 TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
1020 atomic_add_int(&tcp_reass_qsize, -1);
1022 /* throw away SACK blocks in scoreboard*/
1023 if (TCP_DO_SACK(tp))
1024 tcp_sack_destroy(&tp->scb);
1026 inp->inp_ppcb = NULL;
1027 soisdisconnected(so);
1028 /* note: pcb detached later on */
1030 tcp_destroy_timermsg(tp);
1031 tcp_output_cancel(tp);
1033 if (tp->t_flags & TF_LISTEN) {
1034 syncache_destroy(tp, tp_inh);
1035 if (inp_inh != NULL && inp_inh->inp_socket != NULL) {
1037 * Pending sockets inheritance only needs
1038 * to be done once in the current thread,
1041 soinherit(so, inp_inh->inp_socket);
1045 so_async_rcvd_drop(so);
1046 /* Drop the reference for the asynchronized pru_rcvd */
1051 * pcbdetach removes any wildcard hash entry on the current CPU.
1060 tcpstat.tcps_closed++;
1064 static __inline void
1065 tcp_drain_oncpu(struct inpcbinfo *pcbinfo)
1067 struct inpcbhead *head = &pcbinfo->pcblisthead;
1071 * Since we run in netisr, it is MP safe, even if
1072 * we block during the inpcb list iteration, i.e.
1073 * we don't need to use inpcb marker here.
1075 KASSERT(&curthread->td_msgport == netisr_cpuport(pcbinfo->cpu),
1076 ("not in correct netisr"));
1078 LIST_FOREACH(inpb, head, inp_list) {
1080 struct tseg_qent *te;
1082 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1083 (tcpb = intotcpcb(inpb)) != NULL &&
1084 (te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) {
1085 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q);
1086 if (te->tqe_th->th_flags & TH_FIN)
1087 tcpb->t_flags &= ~TF_QUEDFIN;
1090 atomic_add_int(&tcp_reass_qsize, -1);
1097 tcp_drain_dispatch(netmsg_t nmsg)
1100 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */
1103 tcp_drain_oncpu(&tcbinfo[mycpuid]);
1107 tcp_drain_ipi(void *arg __unused)
1110 struct lwkt_msg *msg = &tcp_drain_netmsg[cpu].lmsg;
1113 if (msg->ms_flags & MSGF_DONE)
1114 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg);
1127 * Walk the tcpbs, if existing, and flush the reassembly queue,
1128 * if there is one...
1129 * XXX: The "Net/3" implementation doesn't imply that the TCP
1130 * reassembly queue should be flushed, but in a situation
1131 * where we're really low on mbufs, this is potentially
1133 * YYY: We may consider run tcp_drain_oncpu directly here,
1134 * however, that will require M_WAITOK memory allocation
1135 * for the inpcb marker.
1137 CPUMASK_ASSBMASK(mask, ncpus2);
1138 CPUMASK_ANDMASK(mask, smp_active_mask);
1139 if (CPUMASK_TESTNZERO(mask))
1140 lwkt_send_ipiq_mask(mask, tcp_drain_ipi, NULL);
1144 * Notify a tcp user of an asynchronous error;
1145 * store error as soft error, but wake up user
1146 * (for now, won't do anything until can select for soft error).
1148 * Do not wake up user since there currently is no mechanism for
1149 * reporting soft errors (yet - a kqueue filter may be added).
1152 tcp_notify(struct inpcb *inp, int error)
1154 struct tcpcb *tp = intotcpcb(inp);
1157 * Ignore some errors if we are hooked up.
1158 * If connection hasn't completed, has retransmitted several times,
1159 * and receives a second error, give up now. This is better
1160 * than waiting a long time to establish a connection that
1161 * can never complete.
1163 if (tp->t_state == TCPS_ESTABLISHED &&
1164 (error == EHOSTUNREACH || error == ENETUNREACH ||
1165 error == EHOSTDOWN)) {
1167 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1169 tcp_drop(tp, error);
1171 tp->t_softerror = error;
1173 wakeup(&so->so_timeo);
1180 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1183 struct inpcb *marker;
1191 * The process of preparing the TCB list is too time-consuming and
1192 * resource-intensive to repeat twice on every request.
1194 if (req->oldptr == NULL) {
1195 for (ccpu = 0; ccpu < ncpus2; ++ccpu)
1196 n += tcbinfo[ccpu].ipi_count;
1197 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1201 if (req->newptr != NULL)
1204 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1205 marker->inp_flags |= INP_PLACEMARKER;
1208 * OK, now we're committed to doing something. Run the inpcb list
1209 * for each cpu in the system and construct the output. Use a
1210 * list placemarker to deal with list changes occuring during
1211 * copyout blockages (but otherwise depend on being on the correct
1212 * cpu to avoid races).
1214 origcpu = mycpu->gd_cpuid;
1215 for (ccpu = 0; ccpu < ncpus2 && error == 0; ++ccpu) {
1219 lwkt_migratecpu(ccpu);
1221 n = tcbinfo[ccpu].ipi_count;
1223 LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list);
1225 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1227 * process a snapshot of pcbs, ignoring placemarkers
1228 * and using our own to allow SYSCTL_OUT to block.
1230 LIST_REMOVE(marker, inp_list);
1231 LIST_INSERT_AFTER(inp, marker, inp_list);
1233 if (inp->inp_flags & INP_PLACEMARKER)
1235 if (prison_xinpcb(req->td, inp))
1238 xt.xt_len = sizeof xt;
1239 bcopy(inp, &xt.xt_inp, sizeof *inp);
1240 inp_ppcb = inp->inp_ppcb;
1241 if (inp_ppcb != NULL)
1242 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1244 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1245 if (inp->inp_socket)
1246 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1247 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1251 LIST_REMOVE(marker, inp_list);
1252 if (error == 0 && i < n) {
1253 bzero(&xt, sizeof xt);
1254 xt.xt_len = sizeof xt;
1256 error = SYSCTL_OUT(req, &xt, sizeof xt);
1265 * Make sure we are on the same cpu we were on originally, since
1266 * higher level callers expect this. Also don't pollute caches with
1267 * migrated userland data by (eventually) returning to userland
1268 * on a different cpu.
1270 lwkt_migratecpu(origcpu);
1271 kfree(marker, M_TEMP);
1275 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1276 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1279 tcp_getcred(SYSCTL_HANDLER_ARGS)
1281 struct sockaddr_in addrs[2];
1282 struct ucred cred0, *cred = NULL;
1284 int cpu, origcpu, error;
1286 error = priv_check(req->td, PRIV_ROOT);
1289 error = SYSCTL_IN(req, addrs, sizeof addrs);
1294 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1295 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1297 lwkt_migratecpu(cpu);
1299 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1300 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1301 if (inp == NULL || inp->inp_socket == NULL) {
1303 } else if (inp->inp_socket->so_cred != NULL) {
1304 cred0 = *(inp->inp_socket->so_cred);
1308 lwkt_migratecpu(origcpu);
1313 return SYSCTL_OUT(req, cred, sizeof(struct ucred));
1316 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1317 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1321 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1323 struct sockaddr_in6 addrs[2];
1326 boolean_t mapped = FALSE;
1328 error = priv_check(req->td, PRIV_ROOT);
1331 error = SYSCTL_IN(req, addrs, sizeof addrs);
1334 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1335 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1342 inp = in_pcblookup_hash(&tcbinfo[0],
1343 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1345 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1349 inp = in6_pcblookup_hash(&tcbinfo[0],
1350 &addrs[1].sin6_addr, addrs[1].sin6_port,
1351 &addrs[0].sin6_addr, addrs[0].sin6_port,
1354 if (inp == NULL || inp->inp_socket == NULL) {
1358 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1364 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1366 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1369 struct netmsg_tcp_notify {
1370 struct netmsg_base base;
1371 void (*nm_notify)(struct inpcb *, int);
1372 struct in_addr nm_faddr;
1377 tcp_notifyall_oncpu(netmsg_t msg)
1379 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1382 in_pcbnotifyall(&tcbinfo[mycpuid], nm->nm_faddr,
1383 nm->nm_arg, nm->nm_notify);
1385 nextcpu = mycpuid + 1;
1386 if (nextcpu < ncpus2)
1387 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg);
1389 lwkt_replymsg(&nm->base.lmsg, 0);
1393 tcp_ctlinput(netmsg_t msg)
1395 int cmd = msg->ctlinput.nm_cmd;
1396 struct sockaddr *sa = msg->ctlinput.nm_arg;
1397 struct ip *ip = msg->ctlinput.nm_extra;
1399 struct in_addr faddr;
1402 void (*notify)(struct inpcb *, int) = tcp_notify;
1406 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1410 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1411 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1414 arg = inetctlerrmap[cmd];
1415 if (cmd == PRC_QUENCH) {
1416 notify = tcp_quench;
1417 } else if (icmp_may_rst &&
1418 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1419 cmd == PRC_UNREACH_PORT ||
1420 cmd == PRC_TIMXCEED_INTRANS) &&
1422 notify = tcp_drop_syn_sent;
1423 } else if (cmd == PRC_MSGSIZE) {
1424 struct icmp *icmp = (struct icmp *)
1425 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1427 arg = ntohs(icmp->icmp_nextmtu);
1428 notify = tcp_mtudisc;
1429 } else if (PRC_IS_REDIRECT(cmd)) {
1431 notify = in_rtchange;
1432 } else if (cmd == PRC_HOSTDEAD) {
1438 th = (struct tcphdr *)((caddr_t)ip +
1439 (IP_VHL_HL(ip->ip_vhl) << 2));
1440 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
1441 ip->ip_src.s_addr, th->th_sport);
1442 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
1443 ip->ip_src, th->th_sport, 0, NULL);
1444 if ((inp != NULL) && (inp->inp_socket != NULL)) {
1445 icmpseq = htonl(th->th_seq);
1446 tp = intotcpcb(inp);
1447 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1448 SEQ_LT(icmpseq, tp->snd_max))
1449 (*notify)(inp, arg);
1451 struct in_conninfo inc;
1453 inc.inc_fport = th->th_dport;
1454 inc.inc_lport = th->th_sport;
1455 inc.inc_faddr = faddr;
1456 inc.inc_laddr = ip->ip_src;
1460 syncache_unreach(&inc, th);
1464 struct netmsg_tcp_notify *nm;
1466 KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
1467 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1468 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1469 0, tcp_notifyall_oncpu);
1470 nm->nm_faddr = faddr;
1472 nm->nm_notify = notify;
1474 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg);
1477 lwkt_replymsg(&msg->lmsg, 0);
1483 tcp6_ctlinput(netmsg_t msg)
1485 int cmd = msg->ctlinput.nm_cmd;
1486 struct sockaddr *sa = msg->ctlinput.nm_arg;
1487 void *d = msg->ctlinput.nm_extra;
1489 void (*notify) (struct inpcb *, int) = tcp_notify;
1490 struct ip6_hdr *ip6;
1492 struct ip6ctlparam *ip6cp = NULL;
1493 const struct sockaddr_in6 *sa6_src = NULL;
1495 struct tcp_portonly {
1501 if (sa->sa_family != AF_INET6 ||
1502 sa->sa_len != sizeof(struct sockaddr_in6)) {
1507 if (cmd == PRC_QUENCH)
1508 notify = tcp_quench;
1509 else if (cmd == PRC_MSGSIZE) {
1510 struct ip6ctlparam *ip6cp = d;
1511 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1513 arg = ntohl(icmp6->icmp6_mtu);
1514 notify = tcp_mtudisc;
1515 } else if (!PRC_IS_REDIRECT(cmd) &&
1516 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1520 /* if the parameter is from icmp6, decode it. */
1522 ip6cp = (struct ip6ctlparam *)d;
1524 ip6 = ip6cp->ip6c_ip6;
1525 off = ip6cp->ip6c_off;
1526 sa6_src = ip6cp->ip6c_src;
1530 off = 0; /* fool gcc */
1535 struct in_conninfo inc;
1537 * XXX: We assume that when IPV6 is non NULL,
1538 * M and OFF are valid.
1541 /* check if we can safely examine src and dst ports */
1542 if (m->m_pkthdr.len < off + sizeof *thp)
1545 bzero(&th, sizeof th);
1546 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
1548 in6_pcbnotify(&tcbinfo[0], sa, th.th_dport,
1549 (struct sockaddr *)ip6cp->ip6c_src,
1550 th.th_sport, cmd, arg, notify);
1552 inc.inc_fport = th.th_dport;
1553 inc.inc_lport = th.th_sport;
1554 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1555 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1557 syncache_unreach(&inc, &th);
1559 in6_pcbnotify(&tcbinfo[0], sa, 0,
1560 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1563 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1569 * Following is where TCP initial sequence number generation occurs.
1571 * There are two places where we must use initial sequence numbers:
1572 * 1. In SYN-ACK packets.
1573 * 2. In SYN packets.
1575 * All ISNs for SYN-ACK packets are generated by the syncache. See
1576 * tcp_syncache.c for details.
1578 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1579 * depends on this property. In addition, these ISNs should be
1580 * unguessable so as to prevent connection hijacking. To satisfy
1581 * the requirements of this situation, the algorithm outlined in
1582 * RFC 1948 is used to generate sequence numbers.
1584 * Implementation details:
1586 * Time is based off the system timer, and is corrected so that it
1587 * increases by one megabyte per second. This allows for proper
1588 * recycling on high speed LANs while still leaving over an hour
1591 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1592 * between seeding of isn_secret. This is normally set to zero,
1593 * as reseeding should not be necessary.
1597 #define ISN_BYTES_PER_SECOND 1048576
1599 u_char isn_secret[32];
1600 int isn_last_reseed;
1604 tcp_new_isn(struct tcpcb *tp)
1606 u_int32_t md5_buffer[4];
1609 /* Seed if this is the first use, reseed if requested. */
1610 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1611 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1613 read_random_unlimited(&isn_secret, sizeof isn_secret);
1614 isn_last_reseed = ticks;
1617 /* Compute the md5 hash and return the ISN. */
1619 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1620 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
1622 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
1623 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1624 sizeof(struct in6_addr));
1625 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1626 sizeof(struct in6_addr));
1630 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1631 sizeof(struct in_addr));
1632 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1633 sizeof(struct in_addr));
1635 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1636 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1637 new_isn = (tcp_seq) md5_buffer[0];
1638 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
1643 * When a source quench is received, close congestion window
1644 * to one segment. We will gradually open it again as we proceed.
1647 tcp_quench(struct inpcb *inp, int error)
1649 struct tcpcb *tp = intotcpcb(inp);
1652 tp->snd_cwnd = tp->t_maxseg;
1658 * When a specific ICMP unreachable message is received and the
1659 * connection state is SYN-SENT, drop the connection. This behavior
1660 * is controlled by the icmp_may_rst sysctl.
1663 tcp_drop_syn_sent(struct inpcb *inp, int error)
1665 struct tcpcb *tp = intotcpcb(inp);
1667 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
1668 tcp_drop(tp, error);
1672 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1673 * based on the new value in the route. Also nudge TCP to send something,
1674 * since we know the packet we just sent was dropped.
1675 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1678 tcp_mtudisc(struct inpcb *inp, int mtu)
1680 struct tcpcb *tp = intotcpcb(inp);
1682 struct socket *so = inp->inp_socket;
1685 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1687 const boolean_t isipv6 = FALSE;
1694 * If no MTU is provided in the ICMP message, use the
1695 * next lower likely value, as specified in RFC 1191.
1700 oldmtu = tp->t_maxopd +
1702 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1703 sizeof(struct tcpiphdr));
1704 mtu = ip_next_mtu(oldmtu, 0);
1708 rt = tcp_rtlookup6(&inp->inp_inc);
1710 rt = tcp_rtlookup(&inp->inp_inc);
1712 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1713 mtu = rt->rt_rmx.rmx_mtu;
1717 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1718 sizeof(struct tcpiphdr));
1721 * XXX - The following conditional probably violates the TCP
1722 * spec. The problem is that, since we don't know the
1723 * other end's MSS, we are supposed to use a conservative
1724 * default. But, if we do that, then MTU discovery will
1725 * never actually take place, because the conservative
1726 * default is much less than the MTUs typically seen
1727 * on the Internet today. For the moment, we'll sweep
1728 * this under the carpet.
1730 * The conservative default might not actually be a problem
1731 * if the only case this occurs is when sending an initial
1732 * SYN with options and data to a host we've never talked
1733 * to before. Then, they will reply with an MSS value which
1734 * will get recorded and the new parameters should get
1735 * recomputed. For Further Study.
1737 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1738 maxopd = rt->rt_rmx.rmx_mssopt;
1742 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1743 sizeof(struct tcpiphdr));
1745 if (tp->t_maxopd <= maxopd)
1747 tp->t_maxopd = maxopd;
1750 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1751 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1752 mss -= TCPOLEN_TSTAMP_APPA;
1754 /* round down to multiple of MCLBYTES */
1755 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1757 mss &= ~(MCLBYTES - 1);
1760 mss = (mss / MCLBYTES) * MCLBYTES;
1763 if (so->so_snd.ssb_hiwat < mss)
1764 mss = so->so_snd.ssb_hiwat;
1768 tp->snd_nxt = tp->snd_una;
1770 tcpstat.tcps_mturesent++;
1774 * Look-up the routing entry to the peer of this inpcb. If no route
1775 * is found and it cannot be allocated the return NULL. This routine
1776 * is called by TCP routines that access the rmx structure and by tcp_mss
1777 * to get the interface MTU.
1780 tcp_rtlookup(struct in_conninfo *inc)
1782 struct route *ro = &inc->inc_route;
1784 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1785 /* No route yet, so try to acquire one */
1786 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1788 * unused portions of the structure MUST be zero'd
1789 * out because rtalloc() treats it as opaque data
1791 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1792 ro->ro_dst.sa_family = AF_INET;
1793 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1794 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1804 tcp_rtlookup6(struct in_conninfo *inc)
1806 struct route_in6 *ro6 = &inc->inc6_route;
1808 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1809 /* No route yet, so try to acquire one */
1810 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1812 * unused portions of the structure MUST be zero'd
1813 * out because rtalloc() treats it as opaque data
1815 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1816 ro6->ro_dst.sin6_family = AF_INET6;
1817 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1818 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1819 rtalloc((struct route *)ro6);
1822 return (ro6->ro_rt);
1827 /* compute ESP/AH header size for TCP, including outer IP header. */
1829 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1837 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1839 MGETHDR(m, MB_DONTWAIT, MT_DATA);
1844 if (inp->inp_vflag & INP_IPV6) {
1845 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1847 th = (struct tcphdr *)(ip6 + 1);
1848 m->m_pkthdr.len = m->m_len =
1849 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1850 tcp_fillheaders(tp, ip6, th, FALSE);
1851 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1855 ip = mtod(m, struct ip *);
1856 th = (struct tcphdr *)(ip + 1);
1857 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1858 tcp_fillheaders(tp, ip, th, FALSE);
1859 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1868 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1870 * This code attempts to calculate the bandwidth-delay product as a
1871 * means of determining the optimal window size to maximize bandwidth,
1872 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1873 * routers. This code also does a fairly good job keeping RTTs in check
1874 * across slow links like modems. We implement an algorithm which is very
1875 * similar (but not meant to be) TCP/Vegas. The code operates on the
1876 * transmitter side of a TCP connection and so only effects the transmit
1877 * side of the connection.
1879 * BACKGROUND: TCP makes no provision for the management of buffer space
1880 * at the end points or at the intermediate routers and switches. A TCP
1881 * stream, whether using NewReno or not, will eventually buffer as
1882 * many packets as it is able and the only reason this typically works is
1883 * due to the fairly small default buffers made available for a connection
1884 * (typicaly 16K or 32K). As machines use larger windows and/or window
1885 * scaling it is now fairly easy for even a single TCP connection to blow-out
1886 * all available buffer space not only on the local interface, but on
1887 * intermediate routers and switches as well. NewReno makes a misguided
1888 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1889 * then backing off, then steadily increasing the window again until another
1890 * failure occurs, ad-infinitum. This results in terrible oscillation that
1891 * is only made worse as network loads increase and the idea of intentionally
1892 * blowing out network buffers is, frankly, a terrible way to manage network
1895 * It is far better to limit the transmit window prior to the failure
1896 * condition being achieved. There are two general ways to do this: First
1897 * you can 'scan' through different transmit window sizes and locate the
1898 * point where the RTT stops increasing, indicating that you have filled the
1899 * pipe, then scan backwards until you note that RTT stops decreasing, then
1900 * repeat ad-infinitum. This method works in principle but has severe
1901 * implementation issues due to RTT variances, timer granularity, and
1902 * instability in the algorithm which can lead to many false positives and
1903 * create oscillations as well as interact badly with other TCP streams
1904 * implementing the same algorithm.
1906 * The second method is to limit the window to the bandwidth delay product
1907 * of the link. This is the method we implement. RTT variances and our
1908 * own manipulation of the congestion window, bwnd, can potentially
1909 * destabilize the algorithm. For this reason we have to stabilize the
1910 * elements used to calculate the window. We do this by using the minimum
1911 * observed RTT, the long term average of the observed bandwidth, and
1912 * by adding two segments worth of slop. It isn't perfect but it is able
1913 * to react to changing conditions and gives us a very stable basis on
1914 * which to extend the algorithm.
1917 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1926 * If inflight_enable is disabled in the middle of a tcp connection,
1927 * make sure snd_bwnd is effectively disabled.
1929 if (!tcp_inflight_enable) {
1930 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1931 tp->snd_bandwidth = 0;
1936 * Validate the delta time. If a connection is new or has been idle
1937 * a long time we have to reset the bandwidth calculator.
1941 delta_ticks = save_ticks - tp->t_bw_rtttime;
1942 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1943 tp->t_bw_rtttime = save_ticks;
1944 tp->t_bw_rtseq = ack_seq;
1945 if (tp->snd_bandwidth == 0)
1946 tp->snd_bandwidth = tcp_inflight_min;
1951 * A delta of at least 1 tick is required. Waiting 2 ticks will
1952 * result in better (bw) accuracy. More than that and the ramp-up
1955 if (delta_ticks == 0 || delta_ticks == 1)
1959 * Sanity check, plus ignore pure window update acks.
1961 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1965 * Figure out the bandwidth. Due to the tick granularity this
1966 * is a very rough number and it MUST be averaged over a fairly
1967 * long period of time. XXX we need to take into account a link
1968 * that is not using all available bandwidth, but for now our
1969 * slop will ramp us up if this case occurs and the bandwidth later
1972 ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
1973 tp->t_bw_rtttime = save_ticks;
1974 tp->t_bw_rtseq = ack_seq;
1975 bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4;
1977 tp->snd_bandwidth = bw;
1980 * Calculate the semi-static bandwidth delay product, plus two maximal
1981 * segments. The additional slop puts us squarely in the sweet
1982 * spot and also handles the bandwidth run-up case. Without the
1983 * slop we could be locking ourselves into a lower bandwidth.
1985 * At very high speeds the bw calculation can become overly sensitive
1986 * and error prone when delta_ticks is low (e.g. usually 1). To deal
1987 * with the problem the stab must be scaled to the bw. A stab of 50
1988 * (the default) increases the bw for the purposes of the bwnd
1989 * calculation by 5%.
1991 * Situations Handled:
1992 * (1) Prevents over-queueing of packets on LANs, especially on
1993 * high speed LANs, allowing larger TCP buffers to be
1994 * specified, and also does a good job preventing
1995 * over-queueing of packets over choke points like modems
1996 * (at least for the transmit side).
1998 * (2) Is able to handle changing network loads (bandwidth
1999 * drops so bwnd drops, bandwidth increases so bwnd
2002 * (3) Theoretically should stabilize in the face of multiple
2003 * connections implementing the same algorithm (this may need
2006 * (4) Stability value (defaults to 20 = 2 maximal packets) can
2007 * be adjusted with a sysctl but typically only needs to be on
2008 * very slow connections. A value no smaller then 5 should
2009 * be used, but only reduce this default if you have no other
2013 #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt)
2014 bw += bw * tcp_inflight_stab / 1000;
2015 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
2016 (int)tp->t_maxseg * 2;
2019 if (tcp_inflight_debug > 0) {
2021 if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) {
2023 kprintf("%p ibw %ld bw %ld rttvar %d srtt %d "
2024 "bwnd %ld delta %d snd_win %ld\n",
2025 tp, ibw, bw, tp->t_rttvar, tp->t_srtt,
2026 bwnd, delta_ticks, tp->snd_wnd);
2029 if ((long)bwnd < tcp_inflight_min)
2030 bwnd = tcp_inflight_min;
2031 if (bwnd > tcp_inflight_max)
2032 bwnd = tcp_inflight_max;
2033 if ((long)bwnd < tp->t_maxseg * 2)
2034 bwnd = tp->t_maxseg * 2;
2035 tp->snd_bwnd = bwnd;
2039 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
2042 struct inpcb *inp = tp->t_inpcb;
2044 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE);
2046 const boolean_t isipv6 = FALSE;
2050 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
2051 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
2052 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
2053 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
2056 rt = tcp_rtlookup6(&inp->inp_inc);
2058 rt = tcp_rtlookup(&inp->inp_inc);
2060 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2061 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2062 *maxsegs = tcp_iw_maxsegs;
2063 *capsegs = tcp_iw_capsegs;
2066 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2067 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2071 tcp_initial_window(struct tcpcb *tp)
2073 if (tcp_do_rfc3390) {
2076 * "If the SYN or SYN/ACK is lost, the initial window
2077 * used by a sender after a correctly transmitted SYN
2078 * MUST be one segment consisting of MSS bytes."
2080 * However, we do something a little bit more aggressive
2081 * then RFC3390 here:
2082 * - Only if time spent in the SYN or SYN|ACK retransmition
2083 * >= 3 seconds, the IW is reduced. We do this mainly
2084 * because when RFC3390 is published, the initial RTO is
2085 * still 3 seconds (the threshold we test here), while
2086 * after RFC6298, the initial RTO is 1 second. This
2087 * behaviour probably still falls within the spirit of
2089 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2090 * Mainly to avoid sender and receiver deadlock until
2091 * delayed ACK timer expires. And even RFC2581 does not
2092 * try to reduce IW upon SYN or SYN|ACK retransmition
2096 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2098 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2099 return (2 * tp->t_maxseg);
2101 u_long maxsegs, capsegs;
2103 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2104 return min(maxsegs * tp->t_maxseg,
2105 max(2 * tp->t_maxseg, capsegs * 1460));
2109 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2111 * Mainly to avoid sender and receiver deadlock
2112 * until delayed ACK timer expires.
2114 return (2 * tp->t_maxseg);
2118 #ifdef TCP_SIGNATURE
2120 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2122 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2123 * When called from tcp_input(), we can be sure that th_sum has been
2124 * zeroed out and verified already.
2126 * Return 0 if successful, otherwise return -1.
2128 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2129 * search with the destination IP address, and a 'magic SPI' to be
2130 * determined by the application. This is hardcoded elsewhere to 1179
2131 * right now. Another branch of this code exists which uses the SPD to
2132 * specify per-application flows but it is unstable.
2135 tcpsignature_compute(
2136 struct mbuf *m, /* mbuf chain */
2137 int len, /* length of TCP data */
2138 int optlen, /* length of TCP options */
2139 u_char *buf, /* storage for MD5 digest */
2140 u_int direction) /* direction of flow */
2142 struct ippseudo ippseudo;
2146 struct ipovly *ipovly;
2147 struct secasvar *sav;
2150 struct ip6_hdr *ip6;
2151 struct in6_addr in6;
2157 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2158 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2160 * Extract the destination from the IP header in the mbuf.
2162 ip = mtod(m, struct ip *);
2164 ip6 = NULL; /* Make the compiler happy. */
2167 * Look up an SADB entry which matches the address found in
2170 switch (IP_VHL_V(ip->ip_vhl)) {
2172 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2173 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2176 case (IPV6_VERSION >> 4):
2177 ip6 = mtod(m, struct ip6_hdr *);
2178 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2179 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2188 kprintf("%s: SADB lookup failed\n", __func__);
2194 * Step 1: Update MD5 hash with IP pseudo-header.
2196 * XXX The ippseudo header MUST be digested in network byte order,
2197 * or else we'll fail the regression test. Assume all fields we've
2198 * been doing arithmetic on have been in host byte order.
2199 * XXX One cannot depend on ipovly->ih_len here. When called from
2200 * tcp_output(), the underlying ip_len member has not yet been set.
2202 switch (IP_VHL_V(ip->ip_vhl)) {
2204 ipovly = (struct ipovly *)ip;
2205 ippseudo.ippseudo_src = ipovly->ih_src;
2206 ippseudo.ippseudo_dst = ipovly->ih_dst;
2207 ippseudo.ippseudo_pad = 0;
2208 ippseudo.ippseudo_p = IPPROTO_TCP;
2209 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2210 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2211 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2212 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2216 * RFC 2385, 2.0 Proposal
2217 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2218 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2219 * extended next header value (to form 32 bits), and 32-bit segment
2221 * Note: Upper-Layer Packet Length comes before Next Header.
2223 case (IPV6_VERSION >> 4):
2225 in6_clearscope(&in6);
2226 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2228 in6_clearscope(&in6);
2229 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2230 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2231 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2233 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2234 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2235 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2237 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2238 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2239 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2248 * Step 2: Update MD5 hash with TCP header, excluding options.
2249 * The TCP checksum must be set to zero.
2251 savecsum = th->th_sum;
2253 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2254 th->th_sum = savecsum;
2256 * Step 3: Update MD5 hash with TCP segment data.
2257 * Use m_apply() to avoid an early m_pullup().
2260 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2262 * Step 4: Update MD5 hash with shared secret.
2264 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2265 MD5Final(buf, &ctx);
2266 key_sa_recordxfer(sav, m);
2272 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2275 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2278 #endif /* TCP_SIGNATURE */