tcp: Support settable IW parameters
[dragonfly.git] / sys / netinet / tcp_subr.c
CommitLineData
984263bc 1/*
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2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
f23061d4 4 *
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5 * This code is derived from software contributed to The DragonFly Project
6 * by Jeffrey M. Hsu.
f23061d4 7 *
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8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
f23061d4 19 *
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20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
66d6c637 34/*
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35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
36 * The Regents of the University of California. All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 * must display the following acknowledgement:
48 * This product includes software developed by the University of
49 * California, Berkeley and its contributors.
50 * 4. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 *
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 $
68 */
69
70#include "opt_compat.h"
b1992928 71#include "opt_inet.h"
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72#include "opt_inet6.h"
73#include "opt_ipsec.h"
74#include "opt_tcpdebug.h"
75
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>
dd2b0fb4 82#include <sys/mpipe.h>
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83#include <sys/mbuf.h>
84#ifdef INET6
85#include <sys/domain.h>
86#endif
87#include <sys/proc.h>
895c1f85 88#include <sys/priv.h>
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89#include <sys/socket.h>
90#include <sys/socketvar.h>
91#include <sys/protosw.h>
92#include <sys/random.h>
3f9db7f8 93#include <sys/in_cksum.h>
c7afbe76 94#include <sys/ktr.h>
984263bc 95
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96#include <net/route.h>
97#include <net/if.h>
0ddb6032 98#include <net/netisr.h>
984263bc 99
707ad4ed 100#define _IP_VHL
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101#include <netinet/in.h>
102#include <netinet/in_systm.h>
103#include <netinet/ip.h>
984263bc 104#include <netinet/ip6.h>
984263bc 105#include <netinet/in_pcb.h>
984263bc 106#include <netinet6/in6_pcb.h>
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107#include <netinet/in_var.h>
108#include <netinet/ip_var.h>
984263bc 109#include <netinet6/ip6_var.h>
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110#include <netinet/ip_icmp.h>
111#ifdef INET6
112#include <netinet/icmp6.h>
113#endif
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114#include <netinet/tcp.h>
115#include <netinet/tcp_fsm.h>
116#include <netinet/tcp_seq.h>
117#include <netinet/tcp_timer.h>
a48c5dd5 118#include <netinet/tcp_timer2.h>
984263bc 119#include <netinet/tcp_var.h>
984263bc 120#include <netinet6/tcp6_var.h>
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121#include <netinet/tcpip.h>
122#ifdef TCPDEBUG
123#include <netinet/tcp_debug.h>
124#endif
125#include <netinet6/ip6protosw.h>
126
127#ifdef IPSEC
128#include <netinet6/ipsec.h>
b1992928 129#include <netproto/key/key.h>
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130#ifdef INET6
131#include <netinet6/ipsec6.h>
132#endif
707ad4ed 133#endif
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134
135#ifdef FAST_IPSEC
bf844ffa 136#include <netproto/ipsec/ipsec.h>
984263bc 137#ifdef INET6
bf844ffa 138#include <netproto/ipsec/ipsec6.h>
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139#endif
140#define IPSEC
707ad4ed 141#endif
984263bc 142
984263bc 143#include <sys/md5.h>
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144#include <machine/smp.h>
145
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146#include <sys/msgport2.h>
147#include <sys/mplock2.h>
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148#include <net/netmsg2.h>
149
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150#if !defined(KTR_TCP)
151#define KTR_TCP KTR_ALL
152#endif
c3c96e44 153/*
879a1b60 154KTR_INFO_MASTER(tcp);
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155KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0);
156KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0);
157KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
158#define logtcp(name) KTR_LOG(tcp_ ## name)
879a1b60 159*/
c7afbe76 160
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161struct inpcbinfo tcbinfo[MAXCPU];
162struct tcpcbackqhead tcpcbackq[MAXCPU];
163
0ce0603e 164static struct lwkt_token tcp_port_token =
a3c18566 165 LWKT_TOKEN_INITIALIZER(tcp_port_token);
0ce0603e 166
707ad4ed 167int tcp_mssdflt = TCP_MSS;
f23061d4 168SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
707ad4ed 169 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size");
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170
171#ifdef INET6
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172int tcp_v6mssdflt = TCP6_MSS;
173SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW,
174 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6");
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175#endif
176
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177/*
178 * Minimum MSS we accept and use. This prevents DoS attacks where
179 * we are forced to a ridiculous low MSS like 20 and send hundreds
180 * of packets instead of one. The effect scales with the available
181 * bandwidth and quickly saturates the CPU and network interface
182 * with packet generation and sending. Set to zero to disable MINMSS
183 * checking. This setting prevents us from sending too small packets.
184 */
185int tcp_minmss = TCP_MINMSS;
186SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
187 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
5b0b9fa5 188
984263bc 189#if 0
707ad4ed 190static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
f23061d4 191SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
707ad4ed 192 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time");
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193#endif
194
707ad4ed 195int tcp_do_rfc1323 = 1;
f23061d4 196SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
707ad4ed 197 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
984263bc 198
707ad4ed 199static int tcp_tcbhashsize = 0;
984263bc 200SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
707ad4ed 201 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable");
984263bc 202
707ad4ed 203static int do_tcpdrain = 1;
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204SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
205 "Enable tcp_drain routine for extra help when low on mbufs");
206
707ad4ed 207static int icmp_may_rst = 1;
f23061d4 208SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
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209 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
210
707ad4ed 211static int tcp_isn_reseed_interval = 0;
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212SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
213 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
214
215/*
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216 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on
217 * by default, but with generous values which should allow maximal
218 * bandwidth. In particular, the slop defaults to 50 (5 packets).
219 *
220 * The reason for doing this is that the limiter is the only mechanism we
221 * have which seems to do a really good job preventing receiver RX rings
222 * on network interfaces from getting blown out. Even though GigE/10GigE
223 * is supposed to flow control it looks like either it doesn't actually
224 * do it or Open Source drivers do not properly enable it.
225 *
226 * People using the limiter to reduce bottlenecks on slower WAN connections
227 * should set the slop to 20 (2 packets).
984263bc 228 */
d66b98eb 229static int tcp_inflight_enable = 1;
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230SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
231 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
232
707ad4ed 233static int tcp_inflight_debug = 0;
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234SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
235 &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
236
707ad4ed 237static int tcp_inflight_min = 6144;
984263bc 238SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
707ad4ed 239 &tcp_inflight_min, 0, "Lower bound for TCP inflight window");
984263bc 240
707ad4ed 241static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
984263bc 242SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
707ad4ed 243 &tcp_inflight_max, 0, "Upper bound for TCP inflight window");
984263bc 244
d66b98eb 245static int tcp_inflight_stab = 50;
984263bc 246SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
d66b98eb 247 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)");
984263bc 248
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249static int tcp_do_rfc3390 = 1;
250SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
251 &tcp_do_rfc3390, 0,
252 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
253
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254static u_long tcp_iw_maxsegs = 4;
255SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
256 &tcp_iw_maxsegs, 0, "TCP IW segments max");
257
258static u_long tcp_iw_capsegs = 3;
259SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
260 &tcp_iw_capsegs, 0, "TCP IW segments");
261
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262int tcp_low_rtobase = 1;
263SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW,
264 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)");
265
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266static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
267static struct malloc_pipe tcptemp_mpipe;
268
c3c96e44 269static void tcp_willblock(void);
707ad4ed 270static void tcp_notify (struct inpcb *, int);
984263bc 271
5f7ab76b 272struct tcp_stats tcpstats_percpu[MAXCPU];
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273#ifdef SMP
274static int
275sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
276{
707ad4ed 277 int cpu, error = 0;
2b57d013 278
707ad4ed 279 for (cpu = 0; cpu < ncpus; ++cpu) {
5f7ab76b 280 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
707ad4ed 281 sizeof(struct tcp_stats))))
2b57d013 282 break;
5f7ab76b 283 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
707ad4ed 284 sizeof(struct tcp_stats))))
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285 break;
286 }
287
288 return (error);
289}
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290SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
291 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
292#else
2b57d013 293SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW,
707ad4ed 294 &tcpstat, tcp_stats, "TCP statistics");
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295#endif
296
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297/*
298 * Target size of TCP PCB hash tables. Must be a power of two.
299 *
300 * Note that this can be overridden by the kernel environment
301 * variable net.inet.tcp.tcbhashsize
302 */
303#ifndef TCBHASHSIZE
707ad4ed 304#define TCBHASHSIZE 512
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305#endif
306
307/*
308 * This is the actual shape of what we allocate using the zone
309 * allocator. Doing it this way allows us to protect both structures
310 * using the same generation count, and also eliminates the overhead
311 * of allocating tcpcbs separately. By hiding the structure here,
312 * we avoid changing most of the rest of the code (although it needs
313 * to be changed, eventually, for greater efficiency).
314 */
315#define ALIGNMENT 32
316#define ALIGNM1 (ALIGNMENT - 1)
317struct inp_tp {
318 union {
319 struct inpcb inp;
320 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
321 } inp_tp_u;
322 struct tcpcb tcb;
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323 struct tcp_callout inp_tp_rexmt;
324 struct tcp_callout inp_tp_persist;
325 struct tcp_callout inp_tp_keep;
326 struct tcp_callout inp_tp_2msl;
327 struct tcp_callout inp_tp_delack;
0f758523 328 struct netmsg_tcp_timer inp_tp_timermsg;
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329};
330#undef ALIGNMENT
331#undef ALIGNM1
332
333/*
334 * Tcp initialization
335 */
336void
f3f70f0d 337tcp_init(void)
984263bc 338{
0ce0603e 339 struct inpcbporthead *porthashbase;
85095f20 340 struct inpcbinfo *ticb;
0ce0603e 341 u_long porthashmask;
984263bc 342 int hashsize = TCBHASHSIZE;
d371a63a 343 int cpu;
bf82f9b7 344
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345 /*
346 * note: tcptemp is used for keepalives, and it is ok for an
347 * allocation to fail so do not specify MPF_INT.
348 */
dd2b0fb4 349 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
fdec03d6 350 25, -1, 0, NULL, NULL, NULL);
dd2b0fb4 351
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352 tcp_delacktime = TCPTV_DELACK;
353 tcp_keepinit = TCPTV_KEEP_INIT;
354 tcp_keepidle = TCPTV_KEEP_IDLE;
355 tcp_keepintvl = TCPTV_KEEPINTVL;
356 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
357 tcp_msl = TCPTV_MSL;
358 tcp_rexmit_min = TCPTV_MIN;
359 tcp_rexmit_slop = TCPTV_CPU_VAR;
360
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361 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
362 if (!powerof2(hashsize)) {
a6ec04bc 363 kprintf("WARNING: TCB hash size not a power of 2\n");
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364 hashsize = 512; /* safe default */
365 }
366 tcp_tcbhashsize = hashsize;
0ce0603e 367 porthashbase = hashinit(hashsize, M_PCB, &porthashmask);
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368
369 for (cpu = 0; cpu < ncpus2; cpu++) {
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370 ticb = &tcbinfo[cpu];
371 in_pcbinfo_init(ticb);
372 ticb->cpu = cpu;
373 ticb->hashbase = hashinit(hashsize, M_PCB,
374 &ticb->hashmask);
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375 ticb->porthashbase = porthashbase;
376 ticb->porthashmask = porthashmask;
377 ticb->porttoken = &tcp_port_token;
378#if 0
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379 ticb->porthashbase = hashinit(hashsize, M_PCB,
380 &ticb->porthashmask);
0ce0603e 381#endif
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382 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
383 &ticb->wildcardhashmask);
384 ticb->ipi_size = sizeof(struct inp_tp);
2b1ce38a 385 TAILQ_INIT(&tcpcbackq[cpu]);
d371a63a 386 }
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387
388 tcp_reass_maxseg = nmbclusters / 16;
707ad4ed 389 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg);
3edf7c37 390
984263bc 391#ifdef INET6
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392#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
393#else
394#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
395#endif
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396 if (max_protohdr < TCP_MINPROTOHDR)
397 max_protohdr = TCP_MINPROTOHDR;
398 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
399 panic("tcp_init");
400#undef TCP_MINPROTOHDR
401
2b57d013 402 /*
5f7ab76b 403 * Initialize TCP statistics counters for each CPU.
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404 */
405#ifdef SMP
406 for (cpu = 0; cpu < ncpus; ++cpu) {
5f7ab76b 407 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
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408 }
409#else
410 bzero(&tcpstat, sizeof(struct tcp_stats));
411#endif
412
984263bc 413 syncache_init();
c3c96e44 414 netisr_register_rollup(tcp_willblock);
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415}
416
417static void
c3c96e44 418tcp_willblock(void)
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419{
420 struct tcpcb *tp;
421 int cpu = mycpu->gd_cpuid;
422
423 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) {
424 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
425 tp->t_flags &= ~TF_ONOUTPUTQ;
426 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq);
427 tcp_output(tp);
428 }
429}
430
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431/*
432 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
433 * tcp_template used to store this data in mbufs, but we now recopy it out
434 * of the tcpcb each time to conserve mbufs.
435 */
436void
707ad4ed 437tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr)
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438{
439 struct inpcb *inp = tp->t_inpcb;
440 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
441
442#ifdef INET6
707ad4ed 443 if (inp->inp_vflag & INP_IPV6) {
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444 struct ip6_hdr *ip6;
445
446 ip6 = (struct ip6_hdr *)ip_ptr;
447 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
448 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
449 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
450 (IPV6_VERSION & IPV6_VERSION_MASK);
451 ip6->ip6_nxt = IPPROTO_TCP;
452 ip6->ip6_plen = sizeof(struct tcphdr);
453 ip6->ip6_src = inp->in6p_laddr;
454 ip6->ip6_dst = inp->in6p_faddr;
455 tcp_hdr->th_sum = 0;
456 } else
457#endif
458 {
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JH
459 struct ip *ip = (struct ip *) ip_ptr;
460
461 ip->ip_vhl = IP_VHL_BORING;
462 ip->ip_tos = 0;
463 ip->ip_len = 0;
464 ip->ip_id = 0;
465 ip->ip_off = 0;
466 ip->ip_ttl = 0;
467 ip->ip_sum = 0;
468 ip->ip_p = IPPROTO_TCP;
469 ip->ip_src = inp->inp_laddr;
470 ip->ip_dst = inp->inp_faddr;
471 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
472 ip->ip_dst.s_addr,
473 htons(sizeof(struct tcphdr) + IPPROTO_TCP));
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474 }
475
476 tcp_hdr->th_sport = inp->inp_lport;
477 tcp_hdr->th_dport = inp->inp_fport;
478 tcp_hdr->th_seq = 0;
479 tcp_hdr->th_ack = 0;
480 tcp_hdr->th_x2 = 0;
481 tcp_hdr->th_off = 5;
482 tcp_hdr->th_flags = 0;
483 tcp_hdr->th_win = 0;
484 tcp_hdr->th_urp = 0;
485}
486
487/*
488 * Create template to be used to send tcp packets on a connection.
489 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
490 * use for this function is in keepalives, which use tcp_respond.
491 */
492struct tcptemp *
707ad4ed 493tcp_maketemplate(struct tcpcb *tp)
984263bc 494{
dd2b0fb4 495 struct tcptemp *tmp;
984263bc 496
dd2b0fb4 497 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
707ad4ed 498 return (NULL);
f23061d4 499 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t);
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500 return (tmp);
501}
984263bc 502
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503void
504tcp_freetemplate(struct tcptemp *tmp)
505{
506 mpipe_free(&tcptemp_mpipe, tmp);
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507}
508
509/*
510 * Send a single message to the TCP at address specified by
707ad4ed 511 * the given TCP/IP header. If m == NULL, then we make a copy
984263bc
MD
512 * of the tcpiphdr at ti and send directly to the addressed host.
513 * This is used to force keep alive messages out using the TCP
514 * template for a connection. If flags are given then we send
515 * a message back to the TCP which originated the * segment ti,
516 * and discard the mbuf containing it and any other attached mbufs.
517 *
518 * In any case the ack and sequence number of the transmitted
519 * segment are as specified by the parameters.
520 *
521 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
522 */
523void
707ad4ed
JH
524tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
525 tcp_seq ack, tcp_seq seq, int flags)
984263bc 526{
2256ba69 527 int tlen;
984263bc 528 int win = 0;
707ad4ed 529 struct route *ro = NULL;
984263bc 530 struct route sro;
707ad4ed 531 struct ip *ip = ipgen;
984263bc 532 struct tcphdr *nth;
984263bc 533 int ipflags = 0;
707ad4ed
JH
534 struct route_in6 *ro6 = NULL;
535 struct route_in6 sro6;
536 struct ip6_hdr *ip6 = ipgen;
5a0e5b43 537 boolean_t use_tmpro = TRUE;
984263bc 538#ifdef INET6
707ad4ed
JH
539 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
540#else
541 const boolean_t isipv6 = FALSE;
542#endif
984263bc 543
707ad4ed 544 if (tp != NULL) {
984263bc 545 if (!(flags & TH_RST)) {
6d49aa6f 546 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv);
46e92930
MD
547 if (win < 0)
548 win = 0;
984263bc
MD
549 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
550 win = (long)TCP_MAXWIN << tp->rcv_scale;
551 }
5a0e5b43
SZ
552 /*
553 * Don't use the route cache of a listen socket,
554 * it is not MPSAFE; use temporary route cache.
555 */
556 if (tp->t_state != TCPS_LISTEN) {
557 if (isipv6)
558 ro6 = &tp->t_inpcb->in6p_route;
559 else
560 ro = &tp->t_inpcb->inp_route;
561 use_tmpro = FALSE;
562 }
563 }
564 if (use_tmpro) {
984263bc
MD
565 if (isipv6) {
566 ro6 = &sro6;
567 bzero(ro6, sizeof *ro6);
707ad4ed
JH
568 } else {
569 ro = &sro;
570 bzero(ro, sizeof *ro);
571 }
984263bc 572 }
707ad4ed 573 if (m == NULL) {
74f1caca 574 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
984263bc
MD
575 if (m == NULL)
576 return;
577 tlen = 0;
578 m->m_data += max_linkhdr;
984263bc 579 if (isipv6) {
707ad4ed 580 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
984263bc
MD
581 ip6 = mtod(m, struct ip6_hdr *);
582 nth = (struct tcphdr *)(ip6 + 1);
707ad4ed
JH
583 } else {
584 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
585 ip = mtod(m, struct ip *);
586 nth = (struct tcphdr *)(ip + 1);
587 }
588 bcopy(th, nth, sizeof(struct tcphdr));
984263bc
MD
589 flags = TH_ACK;
590 } else {
591 m_freem(m->m_next);
707ad4ed 592 m->m_next = NULL;
984263bc
MD
593 m->m_data = (caddr_t)ipgen;
594 /* m_len is set later */
595 tlen = 0;
707ad4ed 596#define xchg(a, b, type) { type t; t = a; a = b; b = t; }
984263bc
MD
597 if (isipv6) {
598 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
599 nth = (struct tcphdr *)(ip6 + 1);
707ad4ed
JH
600 } else {
601 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
602 nth = (struct tcphdr *)(ip + 1);
603 }
984263bc
MD
604 if (th != nth) {
605 /*
606 * this is usually a case when an extension header
607 * exists between the IPv6 header and the
608 * TCP header.
609 */
610 nth->th_sport = th->th_sport;
611 nth->th_dport = th->th_dport;
612 }
613 xchg(nth->th_dport, nth->th_sport, n_short);
614#undef xchg
615 }
984263bc
MD
616 if (isipv6) {
617 ip6->ip6_flow = 0;
618 ip6->ip6_vfc = IPV6_VERSION;
619 ip6->ip6_nxt = IPPROTO_TCP;
707ad4ed
JH
620 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
621 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
622 } else {
623 tlen += sizeof(struct tcpiphdr);
624 ip->ip_len = tlen;
625 ip->ip_ttl = ip_defttl;
626 }
984263bc
MD
627 m->m_len = tlen;
628 m->m_pkthdr.len = tlen;
2038fb68 629 m->m_pkthdr.rcvif = NULL;
984263bc
MD
630 nth->th_seq = htonl(seq);
631 nth->th_ack = htonl(ack);
632 nth->th_x2 = 0;
707ad4ed 633 nth->th_off = sizeof(struct tcphdr) >> 2;
984263bc 634 nth->th_flags = flags;
707ad4ed 635 if (tp != NULL)
984263bc
MD
636 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
637 else
638 nth->th_win = htons((u_short)win);
639 nth->th_urp = 0;
984263bc
MD
640 if (isipv6) {
641 nth->th_sum = 0;
642 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
643 sizeof(struct ip6_hdr),
644 tlen - sizeof(struct ip6_hdr));
645 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
707ad4ed 646 (ro6 && ro6->ro_rt) ?
f23061d4 647 ro6->ro_rt->rt_ifp : NULL);
707ad4ed
JH
648 } else {
649 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
650 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
651 m->m_pkthdr.csum_flags = CSUM_TCP;
652 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
653 }
984263bc
MD
654#ifdef TCPDEBUG
655 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
656 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
657#endif
984263bc 658 if (isipv6) {
f23061d4
JH
659 ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
660 tp ? tp->t_inpcb : NULL);
707ad4ed 661 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
984263bc
MD
662 RTFREE(ro6->ro_rt);
663 ro6->ro_rt = NULL;
664 }
707ad4ed 665 } else {
1dbb3516 666 ipflags |= IP_DEBUGROUTE;
f23061d4 667 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
707ad4ed
JH
668 if ((ro == &sro) && (ro->ro_rt != NULL)) {
669 RTFREE(ro->ro_rt);
670 ro->ro_rt = NULL;
671 }
984263bc 672 }
984263bc
MD
673}
674
675/*
676 * Create a new TCP control block, making an
677 * empty reassembly queue and hooking it to the argument
678 * protocol control block. The `inp' parameter must have
679 * come from the zone allocator set up in tcp_init().
680 */
681struct tcpcb *
707ad4ed 682tcp_newtcpcb(struct inpcb *inp)
984263bc
MD
683{
684 struct inp_tp *it;
2256ba69 685 struct tcpcb *tp;
984263bc 686#ifdef INET6
707ad4ed
JH
687 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
688#else
689 const boolean_t isipv6 = FALSE;
690#endif
984263bc
MD
691
692 it = (struct inp_tp *)inp;
693 tp = &it->tcb;
707ad4ed 694 bzero(tp, sizeof(struct tcpcb));
984263bc 695 LIST_INIT(&tp->t_segq);
707ad4ed 696 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
984263bc
MD
697
698 /* Set up our timeouts. */
a48c5dd5
SZ
699 tp->tt_rexmt = &it->inp_tp_rexmt;
700 tp->tt_persist = &it->inp_tp_persist;
701 tp->tt_keep = &it->inp_tp_keep;
702 tp->tt_2msl = &it->inp_tp_2msl;
703 tp->tt_delack = &it->inp_tp_delack;
704 tcp_inittimers(tp);
984263bc 705
3db1c8a3
SZ
706 /*
707 * Zero out timer message. We don't create it here,
708 * since the current CPU may not be the owner of this
709 * inpcb.
710 */
0f758523 711 tp->tt_msg = &it->inp_tp_timermsg;
3db1c8a3 712 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
0f758523 713
2ce132be 714 tp->t_keepinit = tcp_keepinit;
7ea3a353 715 tp->t_keepidle = tcp_keepidle;
5d61ded3
SZ
716 tp->t_keepintvl = tcp_keepintvl;
717 tp->t_keepcnt = tcp_keepcnt;
718 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
2ce132be 719
984263bc 720 if (tcp_do_rfc1323)
707ad4ed 721 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP);
984263bc 722 tp->t_inpcb = inp; /* XXX */
eb594563 723 tp->t_state = TCPS_CLOSED;
984263bc
MD
724 /*
725 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
726 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
727 * reasonable initial retransmit time.
728 */
729 tp->t_srtt = TCPTV_SRTTBASE;
707ad4ed
JH
730 tp->t_rttvar =
731 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
984263bc
MD
732 tp->t_rttmin = tcp_rexmit_min;
733 tp->t_rxtcur = TCPTV_RTOBASE;
734 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
735 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
736 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
737 tp->t_rcvtime = ticks;
707ad4ed 738 /*
984263bc
MD
739 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
740 * because the socket may be bound to an IPv6 wildcard address,
741 * which may match an IPv4-mapped IPv6 address.
742 */
743 inp->inp_ip_ttl = ip_defttl;
f23061d4 744 inp->inp_ppcb = tp;
91489f6b 745 tcp_sack_tcpcb_init(tp);
984263bc
MD
746 return (tp); /* XXX */
747}
748
749/*
707ad4ed
JH
750 * Drop a TCP connection, reporting the specified error.
751 * If connection is synchronized, then send a RST to peer.
984263bc
MD
752 */
753struct tcpcb *
71f385dc 754tcp_drop(struct tcpcb *tp, int error)
984263bc
MD
755{
756 struct socket *so = tp->t_inpcb->inp_socket;
757
758 if (TCPS_HAVERCVDSYN(tp->t_state)) {
759 tp->t_state = TCPS_CLOSED;
f23061d4 760 tcp_output(tp);
984263bc
MD
761 tcpstat.tcps_drops++;
762 } else
763 tcpstat.tcps_conndrops++;
71f385dc
MD
764 if (error == ETIMEDOUT && tp->t_softerror)
765 error = tp->t_softerror;
766 so->so_error = error;
984263bc
MD
767 return (tcp_close(tp));
768}
769
8affadf8 770#ifdef SMP
eb594563 771
ce6f0462 772struct netmsg_listen_detach {
002c1265 773 struct netmsg_base base;
ce6f0462 774 struct tcpcb *nm_tp;
8affadf8
JH
775};
776
4599cf19 777static void
ce6f0462 778tcp_listen_detach_handler(netmsg_t msg)
8affadf8 779{
ce6f0462
SZ
780 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
781 struct tcpcb *tp = nmsg->nm_tp;
782 int cpu = mycpuid, nextcpu;
8affadf8 783
f7b29de5 784 if (tp->t_flags & TF_LISTEN)
ce6f0462 785 syncache_destroy(tp);
eb594563 786
ce6f0462
SZ
787 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
788
789 nextcpu = cpu + 1;
790 if (nextcpu < ncpus2)
791 lwkt_forwardmsg(cpu_portfn(nextcpu), &nmsg->base.lmsg);
792 else
002c1265 793 lwkt_replymsg(&nmsg->base.lmsg, 0);
8affadf8 794}
eb594563 795
8affadf8
JH
796#endif
797
984263bc
MD
798/*
799 * Close a TCP control block:
800 * discard all space held by the tcp
801 * discard internet protocol block
802 * wake up any sleepers
803 */
804struct tcpcb *
707ad4ed 805tcp_close(struct tcpcb *tp)
984263bc 806{
2256ba69 807 struct tseg_qent *q;
984263bc
MD
808 struct inpcb *inp = tp->t_inpcb;
809 struct socket *so = inp->inp_socket;
2256ba69 810 struct rtentry *rt;
707ad4ed
JH
811 boolean_t dosavessthresh;
812#ifdef INET6
813 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0);
eb594563 814 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0);
707ad4ed
JH
815#else
816 const boolean_t isipv6 = FALSE;
817#endif
984263bc 818
ce6f0462 819#ifdef SMP
eb594563 820 /*
ce6f0462
SZ
821 * INP_WILDCARD_MP indicates that listen(2) has been called on
822 * this socket. This implies:
823 * - A wildcard inp's hash is replicated for each protocol thread.
824 * - Syncache for this inp grows independently in each protocol
825 * thread.
985b2cb0 826 * - There is more than one cpu
eb594563 827 *
ce6f0462
SZ
828 * We have to chain a message to the rest of the protocol threads
829 * to cleanup the wildcard hash and the syncache. The cleanup
830 * in the current protocol thread is defered till the end of this
831 * function.
832 *
833 * NOTE:
834 * After cleanup the inp's hash and syncache entries, this inp will
835 * no longer be available to the rest of the protocol threads, so we
836 * are safe to whack the inp in the following code.
eb594563 837 */
ce6f0462
SZ
838 if (inp->inp_flags & INP_WILDCARD_MP) {
839 struct netmsg_listen_detach nmsg;
840
841 KKASSERT(so->so_port == cpu_portfn(0));
842 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
843 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
844
845 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
846 MSGF_PRIORITY, tcp_listen_detach_handler);
847 nmsg.nm_tp = tp;
848 lwkt_domsg(cpu_portfn(1), &nmsg.base.lmsg, 0);
849
850 inp->inp_flags &= ~INP_WILDCARD_MP;
851 }
852#endif
853
eb594563
MD
854 KKASSERT(tp->t_state != TCPS_TERMINATING);
855 tp->t_state = TCPS_TERMINATING;
856
984263bc
MD
857 /*
858 * Make sure that all of our timers are stopped before we
2d42d2b0 859 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
697aadcd
SZ
860 * timers are never used. If timer message is never created
861 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
984263bc 862 */
697aadcd 863 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
2d42d2b0
SZ
864 tcp_callout_stop(tp, tp->tt_rexmt);
865 tcp_callout_stop(tp, tp->tt_persist);
866 tcp_callout_stop(tp, tp->tt_keep);
867 tcp_callout_stop(tp, tp->tt_2msl);
868 tcp_callout_stop(tp, tp->tt_delack);
869 }
984263bc 870
2b1ce38a
MD
871 if (tp->t_flags & TF_ONOUTPUTQ) {
872 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
873 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq);
874 tp->t_flags &= ~TF_ONOUTPUTQ;
875 }
876
984263bc
MD
877 /*
878 * If we got enough samples through the srtt filter,
879 * save the rtt and rttvar in the routing entry.
880 * 'Enough' is arbitrarily defined as the 16 samples.
881 * 16 samples is enough for the srtt filter to converge
882 * to within 5% of the correct value; fewer samples and
883 * we could save a very bogus rtt.
884 *
885 * Don't update the default route's characteristics and don't
886 * update anything that the user "locked".
887 */
888 if (tp->t_rttupdated >= 16) {
2256ba69 889 u_long i = 0;
707ad4ed 890
984263bc
MD
891 if (isipv6) {
892 struct sockaddr_in6 *sin6;
893
894 if ((rt = inp->in6p_route.ro_rt) == NULL)
895 goto no_valid_rt;
896 sin6 = (struct sockaddr_in6 *)rt_key(rt);
897 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
898 goto no_valid_rt;
707ad4ed
JH
899 } else
900 if ((rt = inp->inp_route.ro_rt) == NULL ||
901 ((struct sockaddr_in *)rt_key(rt))->
902 sin_addr.s_addr == INADDR_ANY)
903 goto no_valid_rt;
904
905 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
906 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
984263bc
MD
907 if (rt->rt_rmx.rmx_rtt && i)
908 /*
909 * filter this update to half the old & half
910 * the new values, converting scale.
911 * See route.h and tcp_var.h for a
912 * description of the scaling constants.
913 */
914 rt->rt_rmx.rmx_rtt =
915 (rt->rt_rmx.rmx_rtt + i) / 2;
916 else
917 rt->rt_rmx.rmx_rtt = i;
918 tcpstat.tcps_cachedrtt++;
919 }
707ad4ed 920 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
984263bc
MD
921 i = tp->t_rttvar *
922 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
923 if (rt->rt_rmx.rmx_rttvar && i)
924 rt->rt_rmx.rmx_rttvar =
925 (rt->rt_rmx.rmx_rttvar + i) / 2;
926 else
927 rt->rt_rmx.rmx_rttvar = i;
928 tcpstat.tcps_cachedrttvar++;
929 }
930 /*
931 * The old comment here said:
932 * update the pipelimit (ssthresh) if it has been updated
933 * already or if a pipesize was specified & the threshhold
934 * got below half the pipesize. I.e., wait for bad news
935 * before we start updating, then update on both good
936 * and bad news.
937 *
938 * But we want to save the ssthresh even if no pipesize is
939 * specified explicitly in the route, because such
940 * connections still have an implicit pipesize specified
941 * by the global tcp_sendspace. In the absence of a reliable
942 * way to calculate the pipesize, it will have to do.
943 */
944 i = tp->snd_ssthresh;
945 if (rt->rt_rmx.rmx_sendpipe != 0)
707ad4ed 946 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
984263bc 947 else
6d49aa6f 948 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
707ad4ed
JH
949 if (dosavessthresh ||
950 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
951 (rt->rt_rmx.rmx_ssthresh != 0))) {
984263bc
MD
952 /*
953 * convert the limit from user data bytes to
954 * packets then to packet data bytes.
955 */
956 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
957 if (i < 2)
958 i = 2;
707ad4ed
JH
959 i *= tp->t_maxseg +
960 (isipv6 ?
961 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
962 sizeof(struct tcpiphdr));
984263bc
MD
963 if (rt->rt_rmx.rmx_ssthresh)
964 rt->rt_rmx.rmx_ssthresh =
965 (rt->rt_rmx.rmx_ssthresh + i) / 2;
966 else
967 rt->rt_rmx.rmx_ssthresh = i;
968 tcpstat.tcps_cachedssthresh++;
969 }
970 }
707ad4ed
JH
971
972no_valid_rt:
984263bc
MD
973 /* free the reassembly queue, if any */
974 while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
975 LIST_REMOVE(q, tqe_q);
976 m_freem(q->tqe_m);
884717e1 977 kfree(q, M_TSEGQ);
2d23a8be 978 atomic_add_int(&tcp_reass_qsize, -1);
984263bc 979 }
4617a559 980 /* throw away SACK blocks in scoreboard*/
91489f6b
JH
981 if (TCP_DO_SACK(tp))
982 tcp_sack_cleanup(&tp->scb);
eb594563 983
4617a559 984 inp->inp_ppcb = NULL;
984263bc 985 soisdisconnected(so);
4617a559
MD
986 /* note: pcb detached later on */
987
0f758523 988 tcp_destroy_timermsg(tp);
ce6f0462 989
f7b29de5 990 if (tp->t_flags & TF_LISTEN)
e5fe3477 991 syncache_destroy(tp);
0f758523 992
eb594563 993 /*
ce6f0462
SZ
994 * NOTE:
995 * pcbdetach removes any wildcard hash entry on the current CPU.
eb594563 996 */
984263bc 997#ifdef INET6
ce6f0462
SZ
998 if (isafinet6)
999 in6_pcbdetach(inp);
1000 else
707ad4ed 1001#endif
ce6f0462
SZ
1002 in_pcbdetach(inp);
1003
984263bc 1004 tcpstat.tcps_closed++;
707ad4ed 1005 return (NULL);
984263bc
MD
1006}
1007
3f48f9c5
JH
1008static __inline void
1009tcp_drain_oncpu(struct inpcbhead *head)
984263bc 1010{
2d23a8be 1011 struct inpcb *marker;
d371a63a
JH
1012 struct inpcb *inpb;
1013 struct tcpcb *tcpb;
1014 struct tseg_qent *te;
3f48f9c5 1015
2d23a8be
MD
1016 /*
1017 * Allows us to block while running the list
1018 */
1019 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1020 marker->inp_flags |= INP_PLACEMARKER;
1021 LIST_INSERT_HEAD(head, marker, inp_list);
1022
1023 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) {
1024 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 &&
1025 (tcpb = intotcpcb(inpb)) != NULL &&
1026 (te = LIST_FIRST(&tcpb->t_segq)) != NULL) {
1027 LIST_REMOVE(te, tqe_q);
1028 m_freem(te->tqe_m);
884717e1 1029 kfree(te, M_TSEGQ);
2d23a8be
MD
1030 atomic_add_int(&tcp_reass_qsize, -1);
1031 /* retry */
1032 } else {
1033 LIST_REMOVE(marker, inp_list);
1034 LIST_INSERT_AFTER(inpb, marker, inp_list);
3f48f9c5
JH
1035 }
1036 }
2d23a8be
MD
1037 LIST_REMOVE(marker, inp_list);
1038 kfree(marker, M_TEMP);
3f48f9c5
JH
1039}
1040
0ddb6032
JH
1041#ifdef SMP
1042struct netmsg_tcp_drain {
002c1265 1043 struct netmsg_base base;
0ddb6032
JH
1044 struct inpcbhead *nm_head;
1045};
1046
4599cf19 1047static void
002c1265 1048tcp_drain_handler(netmsg_t msg)
0ddb6032 1049{
002c1265 1050 struct netmsg_tcp_drain *nm = (void *)msg;
0ddb6032
JH
1051
1052 tcp_drain_oncpu(nm->nm_head);
002c1265 1053 lwkt_replymsg(&nm->base.lmsg, 0);
0ddb6032
JH
1054}
1055#endif
1056
3f48f9c5 1057void
f3f70f0d 1058tcp_drain(void)
3f48f9c5 1059{
93c8e032 1060#ifdef SMP
d371a63a 1061 int cpu;
93c8e032 1062#endif
d371a63a
JH
1063
1064 if (!do_tcpdrain)
1065 return;
984263bc
MD
1066
1067 /*
1068 * Walk the tcpbs, if existing, and flush the reassembly queue,
1069 * if there is one...
1070 * XXX: The "Net/3" implementation doesn't imply that the TCP
707ad4ed
JH
1071 * reassembly queue should be flushed, but in a situation
1072 * where we're really low on mbufs, this is potentially
1073 * useful.
984263bc 1074 */
3f48f9c5 1075#ifdef SMP
d371a63a 1076 for (cpu = 0; cpu < ncpus2; cpu++) {
002c1265 1077 struct netmsg_tcp_drain *nm;
3f48f9c5 1078
0ddb6032 1079 if (cpu == mycpu->gd_cpuid) {
d2e9e54c 1080 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead);
3f48f9c5 1081 } else {
002c1265
MD
1082 nm = kmalloc(sizeof(struct netmsg_tcp_drain),
1083 M_LWKTMSG, M_NOWAIT);
1084 if (nm == NULL)
3f48f9c5 1085 continue;
002c1265 1086 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
48e7b118 1087 0, tcp_drain_handler);
002c1265
MD
1088 nm->nm_head = &tcbinfo[cpu].pcblisthead;
1089 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg);
984263bc 1090 }
984263bc 1091 }
3f48f9c5 1092#else
d2e9e54c 1093 tcp_drain_oncpu(&tcbinfo[0].pcblisthead);
3f48f9c5 1094#endif
984263bc
MD
1095}
1096
1097/*
1098 * Notify a tcp user of an asynchronous error;
1099 * store error as soft error, but wake up user
1100 * (for now, won't do anything until can select for soft error).
1101 *
1102 * Do not wake up user since there currently is no mechanism for
1103 * reporting soft errors (yet - a kqueue filter may be added).
1104 */
1105static void
707ad4ed 1106tcp_notify(struct inpcb *inp, int error)
984263bc 1107{
707ad4ed 1108 struct tcpcb *tp = intotcpcb(inp);
984263bc
MD
1109
1110 /*
1111 * Ignore some errors if we are hooked up.
1112 * If connection hasn't completed, has retransmitted several times,
1113 * and receives a second error, give up now. This is better
1114 * than waiting a long time to establish a connection that
1115 * can never complete.
1116 */
1117 if (tp->t_state == TCPS_ESTABLISHED &&
1118 (error == EHOSTUNREACH || error == ENETUNREACH ||
1119 error == EHOSTDOWN)) {
1120 return;
1121 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1122 tp->t_softerror)
1123 tcp_drop(tp, error);
1124 else
1125 tp->t_softerror = error;
1126#if 0
f23061d4 1127 wakeup(&so->so_timeo);
984263bc
MD
1128 sorwakeup(so);
1129 sowwakeup(so);
1130#endif
1131}
1132
1133static int
1134tcp_pcblist(SYSCTL_HANDLER_ARGS)
1135{
d2e9e54c
MD
1136 int error, i, n;
1137 struct inpcb *marker;
1138 struct inpcb *inp;
d2e9e54c
MD
1139 globaldata_t gd;
1140 int origcpu, ccpu;
1141
1142 error = 0;
1143 n = 0;
984263bc
MD
1144
1145 /*
1146 * The process of preparing the TCB list is too time-consuming and
1147 * resource-intensive to repeat twice on every request.
1148 */
707ad4ed 1149 if (req->oldptr == NULL) {
d2e9e54c
MD
1150 for (ccpu = 0; ccpu < ncpus; ++ccpu) {
1151 gd = globaldata_find(ccpu);
1152 n += tcbinfo[gd->gd_cpuid].ipi_count;
1153 }
8d7c364e 1154 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
707ad4ed 1155 return (0);
984263bc
MD
1156 }
1157
707ad4ed
JH
1158 if (req->newptr != NULL)
1159 return (EPERM);
984263bc 1160
efda3bd0 1161 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
d2e9e54c
MD
1162 marker->inp_flags |= INP_PLACEMARKER;
1163
984263bc 1164 /*
d2e9e54c 1165 * OK, now we're committed to doing something. Run the inpcb list
f23061d4 1166 * for each cpu in the system and construct the output. Use a
d2e9e54c
MD
1167 * list placemarker to deal with list changes occuring during
1168 * copyout blockages (but otherwise depend on being on the correct
1169 * cpu to avoid races).
984263bc 1170 */
d2e9e54c
MD
1171 origcpu = mycpu->gd_cpuid;
1172 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) {
1173 globaldata_t rgd;
1174 caddr_t inp_ppcb;
1175 struct xtcpcb xt;
1176 int cpu_id;
1177
1178 cpu_id = (origcpu + ccpu) % ncpus;
da23a592 1179 if ((smp_active_mask & CPUMASK(cpu_id)) == 0)
d2e9e54c
MD
1180 continue;
1181 rgd = globaldata_find(cpu_id);
1182 lwkt_setcpu_self(rgd);
1183
d2e9e54c
MD
1184 n = tcbinfo[cpu_id].ipi_count;
1185
d2e9e54c
MD
1186 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list);
1187 i = 0;
1188 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1189 /*
1190 * process a snapshot of pcbs, ignoring placemarkers
1191 * and using our own to allow SYSCTL_OUT to block.
1192 */
1193 LIST_REMOVE(marker, inp_list);
1194 LIST_INSERT_AFTER(inp, marker, inp_list);
707ad4ed 1195
d2e9e54c
MD
1196 if (inp->inp_flags & INP_PLACEMARKER)
1197 continue;
d2e9e54c
MD
1198 if (prison_xinpcb(req->td, inp))
1199 continue;
984263bc 1200
984263bc 1201 xt.xt_len = sizeof xt;
984263bc
MD
1202 bcopy(inp, &xt.xt_inp, sizeof *inp);
1203 inp_ppcb = inp->inp_ppcb;
1204 if (inp_ppcb != NULL)
1205 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1206 else
707ad4ed 1207 bzero(&xt.xt_tp, sizeof xt.xt_tp);
984263bc
MD
1208 if (inp->inp_socket)
1209 sotoxsocket(inp->inp_socket, &xt.xt_socket);
d2e9e54c
MD
1210 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1211 break;
1212 ++i;
1213 }
1214 LIST_REMOVE(marker, inp_list);
1215 if (error == 0 && i < n) {
0c3c561c
JH
1216 bzero(&xt, sizeof xt);
1217 xt.xt_len = sizeof xt;
d2e9e54c 1218 while (i < n) {
f23061d4 1219 error = SYSCTL_OUT(req, &xt, sizeof xt);
d2e9e54c
MD
1220 if (error)
1221 break;
1222 ++i;
1223 }
1224 }
984263bc 1225 }
d2e9e54c
MD
1226
1227 /*
1228 * Make sure we are on the same cpu we were on originally, since
1229 * higher level callers expect this. Also don't pollute caches with
1230 * migrated userland data by (eventually) returning to userland
1231 * on a different cpu.
1232 */
1233 lwkt_setcpu_self(globaldata_find(origcpu));
efda3bd0 1234 kfree(marker, M_TEMP);
707ad4ed 1235 return (error);
984263bc
MD
1236}
1237
1238SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1239 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1240
1241static int
1242tcp_getcred(SYSCTL_HANDLER_ARGS)
1243{
1244 struct sockaddr_in addrs[2];
1245 struct inpcb *inp;
d371a63a 1246 int cpu;
1cae611f 1247 int error;
984263bc 1248
895c1f85 1249 error = priv_check(req->td, PRIV_ROOT);
707ad4ed 1250 if (error != 0)
984263bc 1251 return (error);
707ad4ed
JH
1252 error = SYSCTL_IN(req, addrs, sizeof addrs);
1253 if (error != 0)
984263bc 1254 return (error);
1cae611f 1255 crit_enter();
d371a63a
JH
1256 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1257 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1258 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1259 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
984263bc
MD
1260 if (inp == NULL || inp->inp_socket == NULL) {
1261 error = ENOENT;
1262 goto out;
1263 }
1264 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1265out:
1cae611f 1266 crit_exit();
984263bc
MD
1267 return (error);
1268}
1269
707ad4ed 1270SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
984263bc
MD
1271 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1272
1273#ifdef INET6
1274static int
1275tcp6_getcred(SYSCTL_HANDLER_ARGS)
1276{
1277 struct sockaddr_in6 addrs[2];
1278 struct inpcb *inp;
1cae611f 1279 int error;
707ad4ed 1280 boolean_t mapped = FALSE;
984263bc 1281
895c1f85 1282 error = priv_check(req->td, PRIV_ROOT);
707ad4ed 1283 if (error != 0)
984263bc 1284 return (error);
707ad4ed
JH
1285 error = SYSCTL_IN(req, addrs, sizeof addrs);
1286 if (error != 0)
984263bc
MD
1287 return (error);
1288 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1289 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
707ad4ed 1290 mapped = TRUE;
984263bc
MD
1291 else
1292 return (EINVAL);
1293 }
1cae611f 1294 crit_enter();
707ad4ed 1295 if (mapped) {
d371a63a
JH
1296 inp = in_pcblookup_hash(&tcbinfo[0],
1297 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1298 addrs[1].sin6_port,
1299 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1300 addrs[0].sin6_port,
1301 0, NULL);
1302 } else {
1303 inp = in6_pcblookup_hash(&tcbinfo[0],
1304 &addrs[1].sin6_addr, addrs[1].sin6_port,
1305 &addrs[0].sin6_addr, addrs[0].sin6_port,
1306 0, NULL);
1307 }
984263bc
MD
1308 if (inp == NULL || inp->inp_socket == NULL) {
1309 error = ENOENT;
1310 goto out;
1311 }
707ad4ed 1312 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
984263bc 1313out:
1cae611f 1314 crit_exit();
984263bc
MD
1315 return (error);
1316}
1317
707ad4ed 1318SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
984263bc
MD
1319 0, 0,
1320 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1321#endif
1322
14572273 1323struct netmsg_tcp_notify {
002c1265 1324 struct netmsg_base base;
14572273
SZ
1325 void (*nm_notify)(struct inpcb *, int);
1326 struct in_addr nm_faddr;
1327 int nm_arg;
1328};
1329
1330static void
002c1265 1331tcp_notifyall_oncpu(netmsg_t msg)
14572273 1332{
002c1265 1333 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
14572273
SZ
1334 int nextcpu;
1335
002c1265
MD
1336 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr,
1337 nm->nm_arg, nm->nm_notify);
14572273
SZ
1338
1339 nextcpu = mycpuid + 1;
1340 if (nextcpu < ncpus2)
002c1265 1341 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
14572273 1342 else
002c1265 1343 lwkt_replymsg(&nm->base.lmsg, 0);
14572273
SZ
1344}
1345
984263bc 1346void
002c1265 1347tcp_ctlinput(netmsg_t msg)
984263bc 1348{
002c1265
MD
1349 int cmd = msg->ctlinput.nm_cmd;
1350 struct sockaddr *sa = msg->ctlinput.nm_arg;
1351 struct ip *ip = msg->ctlinput.nm_extra;
984263bc
MD
1352 struct tcphdr *th;
1353 struct in_addr faddr;
1354 struct inpcb *inp;
1355 struct tcpcb *tp;
707ad4ed 1356 void (*notify)(struct inpcb *, int) = tcp_notify;
7d448528 1357 tcp_seq icmpseq;
1cae611f 1358 int arg, cpu;
7d448528
JH
1359
1360 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
002c1265 1361 goto done;
7d448528 1362 }
984263bc
MD
1363
1364 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1365 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
002c1265 1366 goto done;
984263bc 1367
7d448528
JH
1368 arg = inetctlerrmap[cmd];
1369 if (cmd == PRC_QUENCH) {
984263bc 1370 notify = tcp_quench;
7d448528
JH
1371 } else if (icmp_may_rst &&
1372 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1373 cmd == PRC_UNREACH_PORT ||
1374 cmd == PRC_TIMXCEED_INTRANS) &&
1375 ip != NULL) {
984263bc 1376 notify = tcp_drop_syn_sent;
7d448528
JH
1377 } else if (cmd == PRC_MSGSIZE) {
1378 struct icmp *icmp = (struct icmp *)
1379 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1380
1381 arg = ntohs(icmp->icmp_nextmtu);
984263bc 1382 notify = tcp_mtudisc;
7d448528 1383 } else if (PRC_IS_REDIRECT(cmd)) {
707ad4ed 1384 ip = NULL;
984263bc 1385 notify = in_rtchange;
7d448528 1386 } else if (cmd == PRC_HOSTDEAD) {
707ad4ed 1387 ip = NULL;
7d448528
JH
1388 }
1389
707ad4ed 1390 if (ip != NULL) {
1cae611f 1391 crit_enter();
707ad4ed
JH
1392 th = (struct tcphdr *)((caddr_t)ip +
1393 (IP_VHL_HL(ip->ip_vhl) << 2));
d371a63a 1394 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport,
707ad4ed 1395 ip->ip_src.s_addr, th->th_sport);
d371a63a 1396 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport,
707ad4ed
JH
1397 ip->ip_src, th->th_sport, 0, NULL);
1398 if ((inp != NULL) && (inp->inp_socket != NULL)) {
7d448528 1399 icmpseq = htonl(th->th_seq);
984263bc 1400 tp = intotcpcb(inp);
7d448528
JH
1401 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1402 SEQ_LT(icmpseq, tp->snd_max))
1403 (*notify)(inp, arg);
984263bc
MD
1404 } else {
1405 struct in_conninfo inc;
1406
1407 inc.inc_fport = th->th_dport;
1408 inc.inc_lport = th->th_sport;
1409 inc.inc_faddr = faddr;
1410 inc.inc_laddr = ip->ip_src;
1411#ifdef INET6
1412 inc.inc_isipv6 = 0;
1413#endif
1414 syncache_unreach(&inc, th);
1415 }
1cae611f 1416 crit_exit();
d371a63a 1417 } else {
002c1265 1418 struct netmsg_tcp_notify *nm;
14572273
SZ
1419
1420 KKASSERT(&curthread->td_msgport == cpu_portfn(0));
002c1265
MD
1421 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1422 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
48e7b118 1423 0, tcp_notifyall_oncpu);
002c1265
MD
1424 nm->nm_faddr = faddr;
1425 nm->nm_arg = arg;
1426 nm->nm_notify = notify;
14572273 1427
002c1265 1428 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg);
d371a63a 1429 }
002c1265
MD
1430done:
1431 lwkt_replymsg(&msg->lmsg, 0);
984263bc
MD
1432}
1433
1434#ifdef INET6
002c1265 1435
984263bc 1436void
002c1265 1437tcp6_ctlinput(netmsg_t msg)
984263bc 1438{
002c1265
MD
1439 int cmd = msg->ctlinput.nm_cmd;
1440 struct sockaddr *sa = msg->ctlinput.nm_arg;
1441 void *d = msg->ctlinput.nm_extra;
984263bc 1442 struct tcphdr th;
42a7fc75 1443 void (*notify) (struct inpcb *, int) = tcp_notify;
984263bc
MD
1444 struct ip6_hdr *ip6;
1445 struct mbuf *m;
1446 struct ip6ctlparam *ip6cp = NULL;
1447 const struct sockaddr_in6 *sa6_src = NULL;
1448 int off;
1449 struct tcp_portonly {
1450 u_int16_t th_sport;
1451 u_int16_t th_dport;
1452 } *thp;
7d448528 1453 int arg;
984263bc
MD
1454
1455 if (sa->sa_family != AF_INET6 ||
002c1265
MD
1456 sa->sa_len != sizeof(struct sockaddr_in6)) {
1457 goto out;
1458 }
984263bc 1459
7d448528 1460 arg = 0;
984263bc
MD
1461 if (cmd == PRC_QUENCH)
1462 notify = tcp_quench;
7d448528
JH
1463 else if (cmd == PRC_MSGSIZE) {
1464 struct ip6ctlparam *ip6cp = d;
1465 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1466
1467 arg = ntohl(icmp6->icmp6_mtu);
984263bc 1468 notify = tcp_mtudisc;
7d448528
JH
1469 } else if (!PRC_IS_REDIRECT(cmd) &&
1470 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
002c1265 1471 goto out;
7d448528 1472 }
984263bc
MD
1473
1474 /* if the parameter is from icmp6, decode it. */
1475 if (d != NULL) {
1476 ip6cp = (struct ip6ctlparam *)d;
1477 m = ip6cp->ip6c_m;
1478 ip6 = ip6cp->ip6c_ip6;
1479 off = ip6cp->ip6c_off;
1480 sa6_src = ip6cp->ip6c_src;
1481 } else {
1482 m = NULL;
1483 ip6 = NULL;
1484 off = 0; /* fool gcc */
1485 sa6_src = &sa6_any;
1486 }
1487
707ad4ed 1488 if (ip6 != NULL) {
984263bc
MD
1489 struct in_conninfo inc;
1490 /*
1491 * XXX: We assume that when IPV6 is non NULL,
1492 * M and OFF are valid.
1493 */
1494
1495 /* check if we can safely examine src and dst ports */
707ad4ed 1496 if (m->m_pkthdr.len < off + sizeof *thp)
002c1265 1497 goto out;
984263bc 1498
707ad4ed
JH
1499 bzero(&th, sizeof th);
1500 m_copydata(m, off, sizeof *thp, (caddr_t)&th);
984263bc 1501
d2e9e54c 1502 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport,
984263bc 1503 (struct sockaddr *)ip6cp->ip6c_src,
7d448528 1504 th.th_sport, cmd, arg, notify);
984263bc
MD
1505
1506 inc.inc_fport = th.th_dport;
1507 inc.inc_lport = th.th_sport;
1508 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1509 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1510 inc.inc_isipv6 = 1;
1511 syncache_unreach(&inc, &th);
002c1265 1512 } else {
d2e9e54c 1513 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0,
7d448528 1514 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
002c1265
MD
1515 }
1516out:
1517 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
984263bc 1518}
002c1265 1519
707ad4ed 1520#endif
984263bc
MD
1521
1522/*
1523 * Following is where TCP initial sequence number generation occurs.
1524 *
1525 * There are two places where we must use initial sequence numbers:
1526 * 1. In SYN-ACK packets.
1527 * 2. In SYN packets.
1528 *
1529 * All ISNs for SYN-ACK packets are generated by the syncache. See
1530 * tcp_syncache.c for details.
1531 *
1532 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1533 * depends on this property. In addition, these ISNs should be
1534 * unguessable so as to prevent connection hijacking. To satisfy
1535 * the requirements of this situation, the algorithm outlined in
1536 * RFC 1948 is used to generate sequence numbers.
1537 *
1538 * Implementation details:
1539 *
1540 * Time is based off the system timer, and is corrected so that it
1541 * increases by one megabyte per second. This allows for proper
1542 * recycling on high speed LANs while still leaving over an hour
1543 * before rollover.
1544 *
1545 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1546 * between seeding of isn_secret. This is normally set to zero,
1547 * as reseeding should not be necessary.
1548 *
1549 */
1550
707ad4ed 1551#define ISN_BYTES_PER_SECOND 1048576
984263bc
MD
1552
1553u_char isn_secret[32];
1554int isn_last_reseed;
1555MD5_CTX isn_ctx;
1556
1557tcp_seq
707ad4ed 1558tcp_new_isn(struct tcpcb *tp)
984263bc
MD
1559{
1560 u_int32_t md5_buffer[4];
1561 tcp_seq new_isn;
1562
1563 /* Seed if this is the first use, reseed if requested. */
1564 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
1565 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
1566 < (u_int)ticks))) {
707ad4ed 1567 read_random_unlimited(&isn_secret, sizeof isn_secret);
984263bc
MD
1568 isn_last_reseed = ticks;
1569 }
707ad4ed 1570
984263bc
MD
1571 /* Compute the md5 hash and return the ISN. */
1572 MD5Init(&isn_ctx);
707ad4ed
JH
1573 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short));
1574 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short));
984263bc 1575#ifdef INET6
707ad4ed 1576 if (tp->t_inpcb->inp_vflag & INP_IPV6) {
984263bc
MD
1577 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1578 sizeof(struct in6_addr));
1579 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1580 sizeof(struct in6_addr));
1581 } else
1582#endif
1583 {
1584 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1585 sizeof(struct in_addr));
1586 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1587 sizeof(struct in_addr));
1588 }
1589 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
1590 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1591 new_isn = (tcp_seq) md5_buffer[0];
1592 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
707ad4ed 1593 return (new_isn);
984263bc
MD
1594}
1595
1596/*
1597 * When a source quench is received, close congestion window
1598 * to one segment. We will gradually open it again as we proceed.
1599 */
1600void
71f385dc 1601tcp_quench(struct inpcb *inp, int error)
984263bc
MD
1602{
1603 struct tcpcb *tp = intotcpcb(inp);
1604
8acdb67c 1605 if (tp != NULL) {
984263bc 1606 tp->snd_cwnd = tp->t_maxseg;
8acdb67c
JH
1607 tp->snd_wacked = 0;
1608 }
984263bc
MD
1609}
1610
1611/*
1612 * When a specific ICMP unreachable message is received and the
1613 * connection state is SYN-SENT, drop the connection. This behavior
1614 * is controlled by the icmp_may_rst sysctl.
1615 */
1616void
71f385dc 1617tcp_drop_syn_sent(struct inpcb *inp, int error)
984263bc
MD
1618{
1619 struct tcpcb *tp = intotcpcb(inp);
1620
707ad4ed 1621 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT))
71f385dc 1622 tcp_drop(tp, error);
984263bc
MD
1623}
1624
1625/*
7d448528 1626 * When a `need fragmentation' ICMP is received, update our idea of the MSS
984263bc
MD
1627 * based on the new value in the route. Also nudge TCP to send something,
1628 * since we know the packet we just sent was dropped.
1629 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1630 */
1631void
7d448528 1632tcp_mtudisc(struct inpcb *inp, int mtu)
984263bc
MD
1633{
1634 struct tcpcb *tp = intotcpcb(inp);
1635 struct rtentry *rt;
984263bc 1636 struct socket *so = inp->inp_socket;
7d448528 1637 int maxopd, mss;
984263bc 1638#ifdef INET6
707ad4ed
JH
1639 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0);
1640#else
1641 const boolean_t isipv6 = FALSE;
1642#endif
984263bc 1643
7d448528
JH
1644 if (tp == NULL)
1645 return;
1646
1647 /*
1648 * If no MTU is provided in the ICMP message, use the
1649 * next lower likely value, as specified in RFC 1191.
1650 */
1651 if (mtu == 0) {
1652 int oldmtu;
1653
1654 oldmtu = tp->t_maxopd +
1655 (isipv6 ?
1656 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1657 sizeof(struct tcpiphdr));
1658 mtu = ip_next_mtu(oldmtu, 0);
1659 }
1660
1661 if (isipv6)
1662 rt = tcp_rtlookup6(&inp->inp_inc);
1663 else
1664 rt = tcp_rtlookup(&inp->inp_inc);
1665 if (rt != NULL) {
7d448528
JH
1666 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1667 mtu = rt->rt_rmx.rmx_mtu;
1668
1669 maxopd = mtu -
1670 (isipv6 ?
1671 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1672 sizeof(struct tcpiphdr));
1673
984263bc 1674 /*
7d448528 1675 * XXX - The following conditional probably violates the TCP
984263bc
MD
1676 * spec. The problem is that, since we don't know the
1677 * other end's MSS, we are supposed to use a conservative
1678 * default. But, if we do that, then MTU discovery will
1679 * never actually take place, because the conservative
1680 * default is much less than the MTUs typically seen
1681 * on the Internet today. For the moment, we'll sweep
1682 * this under the carpet.
1683 *
1684 * The conservative default might not actually be a problem
1685 * if the only case this occurs is when sending an initial
1686 * SYN with options and data to a host we've never talked
1687 * to before. Then, they will reply with an MSS value which
1688 * will get recorded and the new parameters should get
1689 * recomputed. For Further Study.
1690 */
27b8aee3
AE
1691 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1692 maxopd = rt->rt_rmx.rmx_mssopt;
7d448528
JH
1693 } else
1694 maxopd = mtu -
1695 (isipv6 ?
1696 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1697 sizeof(struct tcpiphdr));
1698
1699 if (tp->t_maxopd <= maxopd)
1700 return;
1701 tp->t_maxopd = maxopd;
1702
1703 mss = maxopd;
1704 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1705 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1706 mss -= TCPOLEN_TSTAMP_APPA;
1707
7d448528
JH
1708 /* round down to multiple of MCLBYTES */
1709#if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1710 if (mss > MCLBYTES)
1711 mss &= ~(MCLBYTES - 1);
984263bc 1712#else
7d448528
JH
1713 if (mss > MCLBYTES)
1714 mss = (mss / MCLBYTES) * MCLBYTES;
984263bc 1715#endif
984263bc 1716
6d49aa6f
MD
1717 if (so->so_snd.ssb_hiwat < mss)
1718 mss = so->so_snd.ssb_hiwat;
984263bc 1719
7d448528
JH
1720 tp->t_maxseg = mss;
1721 tp->t_rtttime = 0;
1722 tp->snd_nxt = tp->snd_una;
1723 tcp_output(tp);
1724 tcpstat.tcps_mturesent++;
984263bc
MD
1725}
1726
1727/*
1728 * Look-up the routing entry to the peer of this inpcb. If no route
1729 * is found and it cannot be allocated the return NULL. This routine
1730 * is called by TCP routines that access the rmx structure and by tcp_mss
1731 * to get the interface MTU.
1732 */
1733struct rtentry *
707ad4ed 1734tcp_rtlookup(struct in_conninfo *inc)
984263bc 1735{
f23061d4 1736 struct route *ro = &inc->inc_route;
984263bc 1737
f23061d4 1738 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
984263bc
MD
1739 /* No route yet, so try to acquire one */
1740 if (inc->inc_faddr.s_addr != INADDR_ANY) {
88fcebeb
MD
1741 /*
1742 * unused portions of the structure MUST be zero'd
1743 * out because rtalloc() treats it as opaque data
1744 */
1745 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
984263bc
MD
1746 ro->ro_dst.sa_family = AF_INET;
1747 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1748 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1749 inc->inc_faddr;
1750 rtalloc(ro);
984263bc
MD
1751 }
1752 }
f23061d4 1753 return (ro->ro_rt);
984263bc
MD
1754}
1755
1756#ifdef INET6
1757struct rtentry *
707ad4ed 1758tcp_rtlookup6(struct in_conninfo *inc)
984263bc 1759{
f23061d4 1760 struct route_in6 *ro6 = &inc->inc6_route;
984263bc 1761
f23061d4 1762 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
984263bc
MD
1763 /* No route yet, so try to acquire one */
1764 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
88fcebeb
MD
1765 /*
1766 * unused portions of the structure MUST be zero'd
1767 * out because rtalloc() treats it as opaque data
1768 */
1769 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
984263bc
MD
1770 ro6->ro_dst.sin6_family = AF_INET6;
1771 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1772 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1773 rtalloc((struct route *)ro6);
984263bc
MD
1774 }
1775 }
f23061d4 1776 return (ro6->ro_rt);
984263bc 1777}
707ad4ed 1778#endif
984263bc
MD
1779
1780#ifdef IPSEC
1781/* compute ESP/AH header size for TCP, including outer IP header. */
1782size_t
707ad4ed 1783ipsec_hdrsiz_tcp(struct tcpcb *tp)
984263bc
MD
1784{
1785 struct inpcb *inp;
1786 struct mbuf *m;
1787 size_t hdrsiz;
1788 struct ip *ip;
984263bc
MD
1789 struct tcphdr *th;
1790
1791 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
707ad4ed 1792 return (0);
74f1caca 1793 MGETHDR(m, MB_DONTWAIT, MT_DATA);
984263bc 1794 if (!m)
707ad4ed 1795 return (0);
984263bc
MD
1796
1797#ifdef INET6
707ad4ed
JH
1798 if (inp->inp_vflag & INP_IPV6) {
1799 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1800
984263bc
MD
1801 th = (struct tcphdr *)(ip6 + 1);
1802 m->m_pkthdr.len = m->m_len =
707ad4ed 1803 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
984263bc
MD
1804 tcp_fillheaders(tp, ip6, th);
1805 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1806 } else
707ad4ed
JH
1807#endif
1808 {
1809 ip = mtod(m, struct ip *);
1810 th = (struct tcphdr *)(ip + 1);
1811 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1812 tcp_fillheaders(tp, ip, th);
1813 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1814 }
984263bc
MD
1815
1816 m_free(m);
707ad4ed 1817 return (hdrsiz);
984263bc 1818}
707ad4ed 1819#endif
984263bc 1820
984263bc
MD
1821/*
1822 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1823 *
1824 * This code attempts to calculate the bandwidth-delay product as a
1825 * means of determining the optimal window size to maximize bandwidth,
1826 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1827 * routers. This code also does a fairly good job keeping RTTs in check
1828 * across slow links like modems. We implement an algorithm which is very
1829 * similar (but not meant to be) TCP/Vegas. The code operates on the
1830 * transmitter side of a TCP connection and so only effects the transmit
1831 * side of the connection.
1832 *
1833 * BACKGROUND: TCP makes no provision for the management of buffer space
f23061d4 1834 * at the end points or at the intermediate routers and switches. A TCP
984263bc
MD
1835 * stream, whether using NewReno or not, will eventually buffer as
1836 * many packets as it is able and the only reason this typically works is
1837 * due to the fairly small default buffers made available for a connection
1838 * (typicaly 16K or 32K). As machines use larger windows and/or window
1839 * scaling it is now fairly easy for even a single TCP connection to blow-out
f23061d4 1840 * all available buffer space not only on the local interface, but on
984263bc
MD
1841 * intermediate routers and switches as well. NewReno makes a misguided
1842 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1843 * then backing off, then steadily increasing the window again until another
1844 * failure occurs, ad-infinitum. This results in terrible oscillation that
1845 * is only made worse as network loads increase and the idea of intentionally
1846 * blowing out network buffers is, frankly, a terrible way to manage network
1847 * resources.
1848 *
1849 * It is far better to limit the transmit window prior to the failure
1850 * condition being achieved. There are two general ways to do this: First
1851 * you can 'scan' through different transmit window sizes and locate the
1852 * point where the RTT stops increasing, indicating that you have filled the
1853 * pipe, then scan backwards until you note that RTT stops decreasing, then
1854 * repeat ad-infinitum. This method works in principle but has severe
1855 * implementation issues due to RTT variances, timer granularity, and
1856 * instability in the algorithm which can lead to many false positives and
1857 * create oscillations as well as interact badly with other TCP streams
1858 * implementing the same algorithm.
1859 *
1860 * The second method is to limit the window to the bandwidth delay product
1861 * of the link. This is the method we implement. RTT variances and our
f23061d4 1862 * own manipulation of the congestion window, bwnd, can potentially
984263bc
MD
1863 * destabilize the algorithm. For this reason we have to stabilize the
1864 * elements used to calculate the window. We do this by using the minimum
1865 * observed RTT, the long term average of the observed bandwidth, and
1866 * by adding two segments worth of slop. It isn't perfect but it is able
1867 * to react to changing conditions and gives us a very stable basis on
1868 * which to extend the algorithm.
1869 */
1870void
1871tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1872{
1873 u_long bw;
1874 u_long bwnd;
1875 int save_ticks;
421de19e 1876 int delta_ticks;
984263bc
MD
1877
1878 /*
1879 * If inflight_enable is disabled in the middle of a tcp connection,
1880 * make sure snd_bwnd is effectively disabled.
1881 */
707ad4ed 1882 if (!tcp_inflight_enable) {
984263bc
MD
1883 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1884 tp->snd_bandwidth = 0;
1885 return;
1886 }
1887
421de19e
MD
1888 /*
1889 * Validate the delta time. If a connection is new or has been idle
1890 * a long time we have to reset the bandwidth calculator.
1891 */
1892 save_ticks = ticks;
1893 delta_ticks = save_ticks - tp->t_bw_rtttime;
1894 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
1895 tp->t_bw_rtttime = ticks;
1896 tp->t_bw_rtseq = ack_seq;
1897 if (tp->snd_bandwidth == 0)
1898 tp->snd_bandwidth = tcp_inflight_min;
1899 return;
1900 }
1901 if (delta_ticks == 0)
1902 return;
1903
1904 /*
1905 * Sanity check, plus ignore pure window update acks.
1906 */
1907 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
1908 return;
1909
984263bc
MD
1910 /*
1911 * Figure out the bandwidth. Due to the tick granularity this
1912 * is a very rough number and it MUST be averaged over a fairly
1913 * long period of time. XXX we need to take into account a link
1914 * that is not using all available bandwidth, but for now our
1915 * slop will ramp us up if this case occurs and the bandwidth later
1916 * increases.
984263bc 1917 */
421de19e 1918 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
984263bc
MD
1919 tp->t_bw_rtttime = save_ticks;
1920 tp->t_bw_rtseq = ack_seq;
984263bc
MD
1921 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
1922
1923 tp->snd_bandwidth = bw;
1924
1925 /*
1926 * Calculate the semi-static bandwidth delay product, plus two maximal
1927 * segments. The additional slop puts us squarely in the sweet
1928 * spot and also handles the bandwidth run-up case. Without the
1929 * slop we could be locking ourselves into a lower bandwidth.
1930 *
1931 * Situations Handled:
1932 * (1) Prevents over-queueing of packets on LANs, especially on
1933 * high speed LANs, allowing larger TCP buffers to be
f23061d4 1934 * specified, and also does a good job preventing
984263bc
MD
1935 * over-queueing of packets over choke points like modems
1936 * (at least for the transmit side).
1937 *
1938 * (2) Is able to handle changing network loads (bandwidth
1939 * drops so bwnd drops, bandwidth increases so bwnd
1940 * increases).
1941 *
1942 * (3) Theoretically should stabilize in the face of multiple
1943 * connections implementing the same algorithm (this may need
1944 * a little work).
1945 *
f23061d4 1946 * (4) Stability value (defaults to 20 = 2 maximal packets) can
984263bc
MD
1947 * be adjusted with a sysctl but typically only needs to be on
1948 * very slow connections. A value no smaller then 5 should
1949 * be used, but only reduce this default if you have no other
1950 * choice.
1951 */
707ad4ed
JH
1952
1953#define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
1954 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
1955 tcp_inflight_stab * (int)tp->t_maxseg / 10;
984263bc
MD
1956#undef USERTT
1957
1958 if (tcp_inflight_debug > 0) {
1959 static int ltime;
1960 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
1961 ltime = ticks;
a6ec04bc 1962 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
707ad4ed 1963 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd);
984263bc
MD
1964 }
1965 }
1966 if ((long)bwnd < tcp_inflight_min)
1967 bwnd = tcp_inflight_min;
1968 if (bwnd > tcp_inflight_max)
1969 bwnd = tcp_inflight_max;
1970 if ((long)bwnd < tp->t_maxseg * 2)
1971 bwnd = tp->t_maxseg * 2;
1972 tp->snd_bwnd = bwnd;
1973}
b1992928 1974
697020f5
SZ
1975u_long
1976tcp_initial_window(const struct tcpcb *tp)
1977{
fa1b6ee4 1978 if (tcp_do_rfc3390) {
d5082e3d
SZ
1979 /*
1980 * RFC3390:
1981 * "If the SYN or SYN/ACK is lost, the initial window
1982 * used by a sender after a correctly transmitted SYN
1983 * MUST be one segment consisting of MSS bytes."
1984 *
1985 * However, we do something a little bit more aggressive
1986 * then RFC3390 here:
1987 * - Only if time spent in the SYN or SYN|ACK retransmition
1988 * >= 3 seconds, the IW is reduced. We do this mainly
1989 * because when RFC3390 is published, the initial RTO is
1990 * still 3 seconds (the threshold we test here), while
1991 * after RFC6298, the initial RTO is 1 second. This
1992 * behaviour probably still falls within the spirit of
1993 * RFC3390.
1994 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
1995 * Mainly to avoid sender and receiver deadlock until
1996 * delayed ACK timer expires. And even RFC2581 does not
1997 * try to reduce IW upon SYN or SYN|ACK retransmition
1998 * timeout.
1999 *
2000 * See also:
2001 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2002 */
2003 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2004 return (2 * tp->t_maxseg);
2005 } else {
c78a42c9
SZ
2006 return min(tcp_iw_maxsegs * tp->t_maxseg,
2007 max(2 * tp->t_maxseg,
2008 tcp_iw_capsegs * 1460));
d5082e3d 2009 }
fa1b6ee4
SZ
2010 } else {
2011 /*
2012 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2013 *
2014 * Mainly to avoid sender and receiver deadlock
2015 * until delayed ACK timer expires.
2016 */
2017 return (2 * tp->t_maxseg);
2018 }
697020f5
SZ
2019}
2020
b1992928
MD
2021#ifdef TCP_SIGNATURE
2022/*
2023 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2024 *
2025 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2026 * When called from tcp_input(), we can be sure that th_sum has been
2027 * zeroed out and verified already.
2028 *
2029 * Return 0 if successful, otherwise return -1.
2030 *
2031 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2032 * search with the destination IP address, and a 'magic SPI' to be
2033 * determined by the application. This is hardcoded elsewhere to 1179
2034 * right now. Another branch of this code exists which uses the SPD to
2035 * specify per-application flows but it is unstable.
2036 */
2037int
2038tcpsignature_compute(
2039 struct mbuf *m, /* mbuf chain */
2040 int len, /* length of TCP data */
2041 int optlen, /* length of TCP options */
2042 u_char *buf, /* storage for MD5 digest */
2043 u_int direction) /* direction of flow */
2044{
2045 struct ippseudo ippseudo;
2046 MD5_CTX ctx;
2047 int doff;
2048 struct ip *ip;
2049 struct ipovly *ipovly;
2050 struct secasvar *sav;
2051 struct tcphdr *th;
2052#ifdef INET6
2053 struct ip6_hdr *ip6;
2054 struct in6_addr in6;
2055 uint32_t plen;
2056 uint16_t nhdr;
2057#endif /* INET6 */
2058 u_short savecsum;
2059
2060 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2061 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2062 /*
2063 * Extract the destination from the IP header in the mbuf.
2064 */
2065 ip = mtod(m, struct ip *);
2066#ifdef INET6
2067 ip6 = NULL; /* Make the compiler happy. */
2068#endif /* INET6 */
2069 /*
2070 * Look up an SADB entry which matches the address found in
2071 * the segment.
2072 */
2073 switch (IP_VHL_V(ip->ip_vhl)) {
2074 case IPVERSION:
2075 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2076 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2077 break;
2078#ifdef INET6
2079 case (IPV6_VERSION >> 4):
2080 ip6 = mtod(m, struct ip6_hdr *);
2081 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2082 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2083 break;
2084#endif /* INET6 */
2085 default:
2086 return (EINVAL);
2087 /* NOTREACHED */
2088 break;
2089 }
2090 if (sav == NULL) {
2091 kprintf("%s: SADB lookup failed\n", __func__);
2092 return (EINVAL);
2093 }
2094 MD5Init(&ctx);
2095
2096 /*
2097 * Step 1: Update MD5 hash with IP pseudo-header.
2098 *
2099 * XXX The ippseudo header MUST be digested in network byte order,
2100 * or else we'll fail the regression test. Assume all fields we've
2101 * been doing arithmetic on have been in host byte order.
2102 * XXX One cannot depend on ipovly->ih_len here. When called from
2103 * tcp_output(), the underlying ip_len member has not yet been set.
2104 */
2105 switch (IP_VHL_V(ip->ip_vhl)) {
2106 case IPVERSION:
2107 ipovly = (struct ipovly *)ip;
2108 ippseudo.ippseudo_src = ipovly->ih_src;
2109 ippseudo.ippseudo_dst = ipovly->ih_dst;
2110 ippseudo.ippseudo_pad = 0;
2111 ippseudo.ippseudo_p = IPPROTO_TCP;
2112 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2113 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2114 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2115 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2116 break;
2117#ifdef INET6
2118 /*
2119 * RFC 2385, 2.0 Proposal
2120 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2121 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2122 * extended next header value (to form 32 bits), and 32-bit segment
2123 * length.
2124 * Note: Upper-Layer Packet Length comes before Next Header.
2125 */
2126 case (IPV6_VERSION >> 4):
2127 in6 = ip6->ip6_src;
2128 in6_clearscope(&in6);
2129 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2130 in6 = ip6->ip6_dst;
2131 in6_clearscope(&in6);
2132 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2133 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2134 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2135 nhdr = 0;
2136 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2137 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2138 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2139 nhdr = IPPROTO_TCP;
2140 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2141 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2142 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2143 break;
2144#endif /* INET6 */
2145 default:
2146 return (EINVAL);
2147 /* NOTREACHED */
2148 break;
2149 }
2150 /*
2151 * Step 2: Update MD5 hash with TCP header, excluding options.
2152 * The TCP checksum must be set to zero.
2153 */
2154 savecsum = th->th_sum;
2155 th->th_sum = 0;
2156 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2157 th->th_sum = savecsum;
2158 /*
2159 * Step 3: Update MD5 hash with TCP segment data.
2160 * Use m_apply() to avoid an early m_pullup().
2161 */
2162 if (len > 0)
2163 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2164 /*
2165 * Step 4: Update MD5 hash with shared secret.
2166 */
2167 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2168 MD5Final(buf, &ctx);
2169 key_sa_recordxfer(sav, m);
2170 key_freesav(sav);
2171 return (0);
2172}
2173
2174int
2175tcpsignature_apply(void *fstate, void *data, unsigned int len)
2176{
2177
2178 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2179 return (0);
2180}
2181#endif /* TCP_SIGNATURE */