1 /* $NetBSD: tcp_subr.c,v 1.264 2015/09/07 01:56:50 ozaki-r Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c) 1997, 1998, 2000, 2001, 2008 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation 38 * Facility, NASA Ames Research Center. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 /* 63 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 64 * The Regents of the University of California. All rights reserved. 65 * 66 * Redistribution and use in source and binary forms, with or without 67 * modification, are permitted provided that the following conditions 68 * are met: 69 * 1. Redistributions of source code must retain the above copyright 70 * notice, this list of conditions and the following disclaimer. 71 * 2. Redistributions in binary form must reproduce the above copyright 72 * notice, this list of conditions and the following disclaimer in the 73 * documentation and/or other materials provided with the distribution. 74 * 3. Neither the name of the University nor the names of its contributors 75 * may be used to endorse or promote products derived from this software 76 * without specific prior written permission. 77 * 78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 88 * SUCH DAMAGE. 89 * 90 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 91 */ 92 93 #include <sys/cdefs.h> 94 __KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.264 2015/09/07 01:56:50 ozaki-r Exp $"); 95 96 #ifdef _KERNEL_OPT 97 #include "opt_inet.h" 98 #include "opt_ipsec.h" 99 #include "opt_tcp_compat_42.h" 100 #include "opt_inet_csum.h" 101 #include "opt_mbuftrace.h" 102 #endif 103 104 #include <sys/param.h> 105 #include <sys/atomic.h> 106 #include <sys/proc.h> 107 #include <sys/systm.h> 108 #include <sys/mbuf.h> 109 #include <sys/once.h> 110 #include <sys/socket.h> 111 #include <sys/socketvar.h> 112 #include <sys/protosw.h> 113 #include <sys/errno.h> 114 #include <sys/kernel.h> 115 #include <sys/pool.h> 116 #include <sys/md5.h> 117 #include <sys/cprng.h> 118 119 #include <net/route.h> 120 #include <net/if.h> 121 122 #include <netinet/in.h> 123 #include <netinet/in_systm.h> 124 #include <netinet/ip.h> 125 #include <netinet/in_pcb.h> 126 #include <netinet/ip_var.h> 127 #include <netinet/ip_icmp.h> 128 129 #ifdef INET6 130 #ifndef INET 131 #include <netinet/in.h> 132 #endif 133 #include <netinet/ip6.h> 134 #include <netinet6/in6_pcb.h> 135 #include <netinet6/ip6_var.h> 136 #include <netinet6/in6_var.h> 137 #include <netinet6/ip6protosw.h> 138 #include <netinet/icmp6.h> 139 #include <netinet6/nd6.h> 140 #endif 141 142 #include <netinet/tcp.h> 143 #include <netinet/tcp_fsm.h> 144 #include <netinet/tcp_seq.h> 145 #include <netinet/tcp_timer.h> 146 #include <netinet/tcp_var.h> 147 #include <netinet/tcp_vtw.h> 148 #include <netinet/tcp_private.h> 149 #include <netinet/tcp_congctl.h> 150 #include <netinet/tcpip.h> 151 152 #ifdef IPSEC 153 #include <netipsec/ipsec.h> 154 #include <netipsec/xform.h> 155 #ifdef INET6 156 #include <netipsec/ipsec6.h> 157 #endif 158 #include <netipsec/key.h> 159 #endif /* IPSEC*/ 160 161 162 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 163 u_int32_t tcp_now; /* slow ticks, for RFC 1323 timestamps */ 164 165 percpu_t *tcpstat_percpu; 166 167 /* patchable/settable parameters for tcp */ 168 int tcp_mssdflt = TCP_MSS; 169 int tcp_minmss = TCP_MINMSS; 170 int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 171 int tcp_do_rfc1323 = 1; /* window scaling / timestamps (obsolete) */ 172 int tcp_do_rfc1948 = 0; /* ISS by cryptographic hash */ 173 int tcp_do_sack = 1; /* selective acknowledgement */ 174 int tcp_do_win_scale = 1; /* RFC1323 window scaling */ 175 int tcp_do_timestamps = 1; /* RFC1323 timestamps */ 176 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */ 177 int tcp_do_ecn = 0; /* Explicit Congestion Notification */ 178 #ifndef TCP_INIT_WIN 179 #define TCP_INIT_WIN 4 /* initial slow start window */ 180 #endif 181 #ifndef TCP_INIT_WIN_LOCAL 182 #define TCP_INIT_WIN_LOCAL 4 /* initial slow start window for local nets */ 183 #endif 184 /* 185 * Up to 5 we scale linearly, to reach 3 * 1460; then (iw) * 1460. 186 * This is to simulate current behavior for iw == 4 187 */ 188 int tcp_init_win_max[] = { 189 1 * 1460, 190 1 * 1460, 191 2 * 1460, 192 2 * 1460, 193 3 * 1460, 194 5 * 1460, 195 6 * 1460, 196 7 * 1460, 197 8 * 1460, 198 9 * 1460, 199 10 * 1460 200 }; 201 int tcp_init_win = TCP_INIT_WIN; 202 int tcp_init_win_local = TCP_INIT_WIN_LOCAL; 203 int tcp_mss_ifmtu = 0; 204 #ifdef TCP_COMPAT_42 205 int tcp_compat_42 = 1; 206 #else 207 int tcp_compat_42 = 0; 208 #endif 209 int tcp_rst_ppslim = 100; /* 100pps */ 210 int tcp_ackdrop_ppslim = 100; /* 100pps */ 211 int tcp_do_loopback_cksum = 0; 212 int tcp_do_abc = 1; /* RFC3465 Appropriate byte counting. */ 213 int tcp_abc_aggressive = 1; /* 1: L=2*SMSS 0: L=1*SMSS */ 214 int tcp_sack_tp_maxholes = 32; 215 int tcp_sack_globalmaxholes = 1024; 216 int tcp_sack_globalholes = 0; 217 int tcp_ecn_maxretries = 1; 218 int tcp_msl_enable = 1; /* enable TIME_WAIT truncation */ 219 int tcp_msl_loop = PR_SLOWHZ; /* MSL for loopback */ 220 int tcp_msl_local = 5 * PR_SLOWHZ; /* MSL for 'local' */ 221 int tcp_msl_remote = TCPTV_MSL; /* MSL otherwise */ 222 int tcp_msl_remote_threshold = TCPTV_SRTTDFLT; /* RTT threshold */ 223 int tcp_rttlocal = 0; /* Use RTT to decide who's 'local' */ 224 225 int tcp4_vtw_enable = 0; /* 1 to enable */ 226 int tcp6_vtw_enable = 0; /* 1 to enable */ 227 int tcp_vtw_was_enabled = 0; 228 int tcp_vtw_entries = 1 << 4; /* 16 vestigial TIME_WAIT entries */ 229 230 /* tcb hash */ 231 #ifndef TCBHASHSIZE 232 #define TCBHASHSIZE 128 233 #endif 234 int tcbhashsize = TCBHASHSIZE; 235 236 /* syn hash parameters */ 237 #define TCP_SYN_HASH_SIZE 293 238 #define TCP_SYN_BUCKET_SIZE 35 239 int tcp_syn_cache_size = TCP_SYN_HASH_SIZE; 240 int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE; 241 int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE; 242 struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE]; 243 244 int tcp_freeq(struct tcpcb *); 245 static int tcp_iss_secret_init(void); 246 247 #ifdef INET 248 static void tcp_mtudisc_callback(struct in_addr); 249 #endif 250 251 #ifdef INET6 252 void tcp6_mtudisc(struct in6pcb *, int); 253 #endif 254 255 static struct pool tcpcb_pool; 256 257 static int tcp_drainwanted; 258 259 #ifdef TCP_CSUM_COUNTERS 260 #include <sys/device.h> 261 262 #if defined(INET) 263 struct evcnt tcp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 264 NULL, "tcp", "hwcsum bad"); 265 struct evcnt tcp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 266 NULL, "tcp", "hwcsum ok"); 267 struct evcnt tcp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 268 NULL, "tcp", "hwcsum data"); 269 struct evcnt tcp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 270 NULL, "tcp", "swcsum"); 271 272 EVCNT_ATTACH_STATIC(tcp_hwcsum_bad); 273 EVCNT_ATTACH_STATIC(tcp_hwcsum_ok); 274 EVCNT_ATTACH_STATIC(tcp_hwcsum_data); 275 EVCNT_ATTACH_STATIC(tcp_swcsum); 276 #endif /* defined(INET) */ 277 278 #if defined(INET6) 279 struct evcnt tcp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 280 NULL, "tcp6", "hwcsum bad"); 281 struct evcnt tcp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 282 NULL, "tcp6", "hwcsum ok"); 283 struct evcnt tcp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 284 NULL, "tcp6", "hwcsum data"); 285 struct evcnt tcp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 286 NULL, "tcp6", "swcsum"); 287 288 EVCNT_ATTACH_STATIC(tcp6_hwcsum_bad); 289 EVCNT_ATTACH_STATIC(tcp6_hwcsum_ok); 290 EVCNT_ATTACH_STATIC(tcp6_hwcsum_data); 291 EVCNT_ATTACH_STATIC(tcp6_swcsum); 292 #endif /* defined(INET6) */ 293 #endif /* TCP_CSUM_COUNTERS */ 294 295 296 #ifdef TCP_OUTPUT_COUNTERS 297 #include <sys/device.h> 298 299 struct evcnt tcp_output_bigheader = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 300 NULL, "tcp", "output big header"); 301 struct evcnt tcp_output_predict_hit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 302 NULL, "tcp", "output predict hit"); 303 struct evcnt tcp_output_predict_miss = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 304 NULL, "tcp", "output predict miss"); 305 struct evcnt tcp_output_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 306 NULL, "tcp", "output copy small"); 307 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 308 NULL, "tcp", "output copy big"); 309 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 310 NULL, "tcp", "output reference big"); 311 312 EVCNT_ATTACH_STATIC(tcp_output_bigheader); 313 EVCNT_ATTACH_STATIC(tcp_output_predict_hit); 314 EVCNT_ATTACH_STATIC(tcp_output_predict_miss); 315 EVCNT_ATTACH_STATIC(tcp_output_copysmall); 316 EVCNT_ATTACH_STATIC(tcp_output_copybig); 317 EVCNT_ATTACH_STATIC(tcp_output_refbig); 318 319 #endif /* TCP_OUTPUT_COUNTERS */ 320 321 #ifdef TCP_REASS_COUNTERS 322 #include <sys/device.h> 323 324 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 325 NULL, "tcp_reass", "calls"); 326 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 327 &tcp_reass_, "tcp_reass", "insert into empty queue"); 328 struct evcnt tcp_reass_iteration[8] = { 329 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"), 330 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"), 331 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"), 332 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"), 333 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"), 334 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"), 335 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"), 336 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"), 337 }; 338 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 339 &tcp_reass_, "tcp_reass", "prepend to first"); 340 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 341 &tcp_reass_, "tcp_reass", "prepend"); 342 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 343 &tcp_reass_, "tcp_reass", "insert"); 344 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 345 &tcp_reass_, "tcp_reass", "insert at tail"); 346 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 347 &tcp_reass_, "tcp_reass", "append"); 348 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 349 &tcp_reass_, "tcp_reass", "append to tail fragment"); 350 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 351 &tcp_reass_, "tcp_reass", "overlap at end"); 352 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 353 &tcp_reass_, "tcp_reass", "overlap at start"); 354 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 355 &tcp_reass_, "tcp_reass", "duplicate segment"); 356 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 357 &tcp_reass_, "tcp_reass", "duplicate fragment"); 358 359 EVCNT_ATTACH_STATIC(tcp_reass_); 360 EVCNT_ATTACH_STATIC(tcp_reass_empty); 361 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 0); 362 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 1); 363 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 2); 364 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 3); 365 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 4); 366 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 5); 367 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 6); 368 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 7); 369 EVCNT_ATTACH_STATIC(tcp_reass_prependfirst); 370 EVCNT_ATTACH_STATIC(tcp_reass_prepend); 371 EVCNT_ATTACH_STATIC(tcp_reass_insert); 372 EVCNT_ATTACH_STATIC(tcp_reass_inserttail); 373 EVCNT_ATTACH_STATIC(tcp_reass_append); 374 EVCNT_ATTACH_STATIC(tcp_reass_appendtail); 375 EVCNT_ATTACH_STATIC(tcp_reass_overlaptail); 376 EVCNT_ATTACH_STATIC(tcp_reass_overlapfront); 377 EVCNT_ATTACH_STATIC(tcp_reass_segdup); 378 EVCNT_ATTACH_STATIC(tcp_reass_fragdup); 379 380 #endif /* TCP_REASS_COUNTERS */ 381 382 #ifdef MBUFTRACE 383 struct mowner tcp_mowner = MOWNER_INIT("tcp", ""); 384 struct mowner tcp_rx_mowner = MOWNER_INIT("tcp", "rx"); 385 struct mowner tcp_tx_mowner = MOWNER_INIT("tcp", "tx"); 386 struct mowner tcp_sock_mowner = MOWNER_INIT("tcp", "sock"); 387 struct mowner tcp_sock_rx_mowner = MOWNER_INIT("tcp", "sock rx"); 388 struct mowner tcp_sock_tx_mowner = MOWNER_INIT("tcp", "sock tx"); 389 #endif 390 391 callout_t tcp_slowtimo_ch; 392 393 static int 394 do_tcpinit(void) 395 { 396 397 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize); 398 pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl", 399 NULL, IPL_SOFTNET); 400 401 tcp_usrreq_init(); 402 403 /* Initialize timer state. */ 404 tcp_timer_init(); 405 406 /* Initialize the compressed state engine. */ 407 syn_cache_init(); 408 409 /* Initialize the congestion control algorithms. */ 410 tcp_congctl_init(); 411 412 /* Initialize the TCPCB template. */ 413 tcp_tcpcb_template(); 414 415 /* Initialize reassembly queue */ 416 tcpipqent_init(); 417 418 /* SACK */ 419 tcp_sack_init(); 420 421 MOWNER_ATTACH(&tcp_tx_mowner); 422 MOWNER_ATTACH(&tcp_rx_mowner); 423 MOWNER_ATTACH(&tcp_reass_mowner); 424 MOWNER_ATTACH(&tcp_sock_mowner); 425 MOWNER_ATTACH(&tcp_sock_tx_mowner); 426 MOWNER_ATTACH(&tcp_sock_rx_mowner); 427 MOWNER_ATTACH(&tcp_mowner); 428 429 tcpstat_percpu = percpu_alloc(sizeof(uint64_t) * TCP_NSTATS); 430 431 vtw_earlyinit(); 432 433 callout_init(&tcp_slowtimo_ch, CALLOUT_MPSAFE); 434 callout_reset(&tcp_slowtimo_ch, 1, tcp_slowtimo, NULL); 435 436 return 0; 437 } 438 439 void 440 tcp_init_common(unsigned basehlen) 441 { 442 static ONCE_DECL(dotcpinit); 443 unsigned hlen = basehlen + sizeof(struct tcphdr); 444 unsigned oldhlen; 445 446 if (max_linkhdr + hlen > MHLEN) 447 panic("tcp_init"); 448 while ((oldhlen = max_protohdr) < hlen) 449 atomic_cas_uint(&max_protohdr, oldhlen, hlen); 450 451 RUN_ONCE(&dotcpinit, do_tcpinit); 452 } 453 454 /* 455 * Tcp initialization 456 */ 457 void 458 tcp_init(void) 459 { 460 461 icmp_mtudisc_callback_register(tcp_mtudisc_callback); 462 463 tcp_init_common(sizeof(struct ip)); 464 } 465 466 /* 467 * Create template to be used to send tcp packets on a connection. 468 * Call after host entry created, allocates an mbuf and fills 469 * in a skeletal tcp/ip header, minimizing the amount of work 470 * necessary when the connection is used. 471 */ 472 struct mbuf * 473 tcp_template(struct tcpcb *tp) 474 { 475 struct inpcb *inp = tp->t_inpcb; 476 #ifdef INET6 477 struct in6pcb *in6p = tp->t_in6pcb; 478 #endif 479 struct tcphdr *n; 480 struct mbuf *m; 481 int hlen; 482 483 switch (tp->t_family) { 484 case AF_INET: 485 hlen = sizeof(struct ip); 486 if (inp) 487 break; 488 #ifdef INET6 489 if (in6p) { 490 /* mapped addr case */ 491 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) 492 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) 493 break; 494 } 495 #endif 496 return NULL; /*EINVAL*/ 497 #ifdef INET6 498 case AF_INET6: 499 hlen = sizeof(struct ip6_hdr); 500 if (in6p) { 501 /* more sainty check? */ 502 break; 503 } 504 return NULL; /*EINVAL*/ 505 #endif 506 default: 507 hlen = 0; /*pacify gcc*/ 508 return NULL; /*EAFNOSUPPORT*/ 509 } 510 #ifdef DIAGNOSTIC 511 if (hlen + sizeof(struct tcphdr) > MCLBYTES) 512 panic("mclbytes too small for t_template"); 513 #endif 514 m = tp->t_template; 515 if (m && m->m_len == hlen + sizeof(struct tcphdr)) 516 ; 517 else { 518 if (m) 519 m_freem(m); 520 m = tp->t_template = NULL; 521 MGETHDR(m, M_DONTWAIT, MT_HEADER); 522 if (m && hlen + sizeof(struct tcphdr) > MHLEN) { 523 MCLGET(m, M_DONTWAIT); 524 if ((m->m_flags & M_EXT) == 0) { 525 m_free(m); 526 m = NULL; 527 } 528 } 529 if (m == NULL) 530 return NULL; 531 MCLAIM(m, &tcp_mowner); 532 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr); 533 } 534 535 memset(mtod(m, void *), 0, m->m_len); 536 537 n = (struct tcphdr *)(mtod(m, char *) + hlen); 538 539 switch (tp->t_family) { 540 case AF_INET: 541 { 542 struct ipovly *ipov; 543 mtod(m, struct ip *)->ip_v = 4; 544 mtod(m, struct ip *)->ip_hl = hlen >> 2; 545 ipov = mtod(m, struct ipovly *); 546 ipov->ih_pr = IPPROTO_TCP; 547 ipov->ih_len = htons(sizeof(struct tcphdr)); 548 if (inp) { 549 ipov->ih_src = inp->inp_laddr; 550 ipov->ih_dst = inp->inp_faddr; 551 } 552 #ifdef INET6 553 else if (in6p) { 554 /* mapped addr case */ 555 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src, 556 sizeof(ipov->ih_src)); 557 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst, 558 sizeof(ipov->ih_dst)); 559 } 560 #endif 561 /* 562 * Compute the pseudo-header portion of the checksum 563 * now. We incrementally add in the TCP option and 564 * payload lengths later, and then compute the TCP 565 * checksum right before the packet is sent off onto 566 * the wire. 567 */ 568 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr, 569 ipov->ih_dst.s_addr, 570 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 571 break; 572 } 573 #ifdef INET6 574 case AF_INET6: 575 { 576 struct ip6_hdr *ip6; 577 mtod(m, struct ip *)->ip_v = 6; 578 ip6 = mtod(m, struct ip6_hdr *); 579 ip6->ip6_nxt = IPPROTO_TCP; 580 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 581 ip6->ip6_src = in6p->in6p_laddr; 582 ip6->ip6_dst = in6p->in6p_faddr; 583 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK; 584 if (ip6_auto_flowlabel) { 585 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK; 586 ip6->ip6_flow |= 587 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 588 } 589 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 590 ip6->ip6_vfc |= IPV6_VERSION; 591 592 /* 593 * Compute the pseudo-header portion of the checksum 594 * now. We incrementally add in the TCP option and 595 * payload lengths later, and then compute the TCP 596 * checksum right before the packet is sent off onto 597 * the wire. 598 */ 599 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr, 600 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)), 601 htonl(IPPROTO_TCP)); 602 break; 603 } 604 #endif 605 } 606 if (inp) { 607 n->th_sport = inp->inp_lport; 608 n->th_dport = inp->inp_fport; 609 } 610 #ifdef INET6 611 else if (in6p) { 612 n->th_sport = in6p->in6p_lport; 613 n->th_dport = in6p->in6p_fport; 614 } 615 #endif 616 n->th_seq = 0; 617 n->th_ack = 0; 618 n->th_x2 = 0; 619 n->th_off = 5; 620 n->th_flags = 0; 621 n->th_win = 0; 622 n->th_urp = 0; 623 return (m); 624 } 625 626 /* 627 * Send a single message to the TCP at address specified by 628 * the given TCP/IP header. If m == 0, then we make a copy 629 * of the tcpiphdr at ti and send directly to the addressed host. 630 * This is used to force keep alive messages out using the TCP 631 * template for a connection tp->t_template. If flags are given 632 * then we send a message back to the TCP which originated the 633 * segment ti, and discard the mbuf containing it and any other 634 * attached mbufs. 635 * 636 * In any case the ack and sequence number of the transmitted 637 * segment are as specified by the parameters. 638 */ 639 int 640 tcp_respond(struct tcpcb *tp, struct mbuf *mtemplate, struct mbuf *m, 641 struct tcphdr *th0, tcp_seq ack, tcp_seq seq, int flags) 642 { 643 struct route *ro; 644 int error, tlen, win = 0; 645 int hlen; 646 struct ip *ip; 647 #ifdef INET6 648 struct ip6_hdr *ip6; 649 #endif 650 int family; /* family on packet, not inpcb/in6pcb! */ 651 struct tcphdr *th; 652 struct socket *so; 653 654 if (tp != NULL && (flags & TH_RST) == 0) { 655 #ifdef DIAGNOSTIC 656 if (tp->t_inpcb && tp->t_in6pcb) 657 panic("tcp_respond: both t_inpcb and t_in6pcb are set"); 658 #endif 659 #ifdef INET 660 if (tp->t_inpcb) 661 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 662 #endif 663 #ifdef INET6 664 if (tp->t_in6pcb) 665 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv); 666 #endif 667 } 668 669 th = NULL; /* Quell uninitialized warning */ 670 ip = NULL; 671 #ifdef INET6 672 ip6 = NULL; 673 #endif 674 if (m == 0) { 675 if (!mtemplate) 676 return EINVAL; 677 678 /* get family information from template */ 679 switch (mtod(mtemplate, struct ip *)->ip_v) { 680 case 4: 681 family = AF_INET; 682 hlen = sizeof(struct ip); 683 break; 684 #ifdef INET6 685 case 6: 686 family = AF_INET6; 687 hlen = sizeof(struct ip6_hdr); 688 break; 689 #endif 690 default: 691 return EAFNOSUPPORT; 692 } 693 694 MGETHDR(m, M_DONTWAIT, MT_HEADER); 695 if (m) { 696 MCLAIM(m, &tcp_tx_mowner); 697 MCLGET(m, M_DONTWAIT); 698 if ((m->m_flags & M_EXT) == 0) { 699 m_free(m); 700 m = NULL; 701 } 702 } 703 if (m == NULL) 704 return (ENOBUFS); 705 706 if (tcp_compat_42) 707 tlen = 1; 708 else 709 tlen = 0; 710 711 m->m_data += max_linkhdr; 712 bcopy(mtod(mtemplate, void *), mtod(m, void *), 713 mtemplate->m_len); 714 switch (family) { 715 case AF_INET: 716 ip = mtod(m, struct ip *); 717 th = (struct tcphdr *)(ip + 1); 718 break; 719 #ifdef INET6 720 case AF_INET6: 721 ip6 = mtod(m, struct ip6_hdr *); 722 th = (struct tcphdr *)(ip6 + 1); 723 break; 724 #endif 725 #if 0 726 default: 727 /* noone will visit here */ 728 m_freem(m); 729 return EAFNOSUPPORT; 730 #endif 731 } 732 flags = TH_ACK; 733 } else { 734 735 if ((m->m_flags & M_PKTHDR) == 0) { 736 #if 0 737 printf("non PKTHDR to tcp_respond\n"); 738 #endif 739 m_freem(m); 740 return EINVAL; 741 } 742 #ifdef DIAGNOSTIC 743 if (!th0) 744 panic("th0 == NULL in tcp_respond"); 745 #endif 746 747 /* get family information from m */ 748 switch (mtod(m, struct ip *)->ip_v) { 749 case 4: 750 family = AF_INET; 751 hlen = sizeof(struct ip); 752 ip = mtod(m, struct ip *); 753 break; 754 #ifdef INET6 755 case 6: 756 family = AF_INET6; 757 hlen = sizeof(struct ip6_hdr); 758 ip6 = mtod(m, struct ip6_hdr *); 759 break; 760 #endif 761 default: 762 m_freem(m); 763 return EAFNOSUPPORT; 764 } 765 /* clear h/w csum flags inherited from rx packet */ 766 m->m_pkthdr.csum_flags = 0; 767 768 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2)) 769 tlen = sizeof(*th0); 770 else 771 tlen = th0->th_off << 2; 772 773 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 && 774 mtod(m, char *) + hlen == (char *)th0) { 775 m->m_len = hlen + tlen; 776 m_freem(m->m_next); 777 m->m_next = NULL; 778 } else { 779 struct mbuf *n; 780 781 #ifdef DIAGNOSTIC 782 if (max_linkhdr + hlen + tlen > MCLBYTES) { 783 m_freem(m); 784 return EMSGSIZE; 785 } 786 #endif 787 MGETHDR(n, M_DONTWAIT, MT_HEADER); 788 if (n && max_linkhdr + hlen + tlen > MHLEN) { 789 MCLGET(n, M_DONTWAIT); 790 if ((n->m_flags & M_EXT) == 0) { 791 m_freem(n); 792 n = NULL; 793 } 794 } 795 if (!n) { 796 m_freem(m); 797 return ENOBUFS; 798 } 799 800 MCLAIM(n, &tcp_tx_mowner); 801 n->m_data += max_linkhdr; 802 n->m_len = hlen + tlen; 803 m_copyback(n, 0, hlen, mtod(m, void *)); 804 m_copyback(n, hlen, tlen, (void *)th0); 805 806 m_freem(m); 807 m = n; 808 n = NULL; 809 } 810 811 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 812 switch (family) { 813 case AF_INET: 814 ip = mtod(m, struct ip *); 815 th = (struct tcphdr *)(ip + 1); 816 ip->ip_p = IPPROTO_TCP; 817 xchg(ip->ip_dst, ip->ip_src, struct in_addr); 818 ip->ip_p = IPPROTO_TCP; 819 break; 820 #ifdef INET6 821 case AF_INET6: 822 ip6 = mtod(m, struct ip6_hdr *); 823 th = (struct tcphdr *)(ip6 + 1); 824 ip6->ip6_nxt = IPPROTO_TCP; 825 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 826 ip6->ip6_nxt = IPPROTO_TCP; 827 break; 828 #endif 829 #if 0 830 default: 831 /* noone will visit here */ 832 m_freem(m); 833 return EAFNOSUPPORT; 834 #endif 835 } 836 xchg(th->th_dport, th->th_sport, u_int16_t); 837 #undef xchg 838 tlen = 0; /*be friendly with the following code*/ 839 } 840 th->th_seq = htonl(seq); 841 th->th_ack = htonl(ack); 842 th->th_x2 = 0; 843 if ((flags & TH_SYN) == 0) { 844 if (tp) 845 win >>= tp->rcv_scale; 846 if (win > TCP_MAXWIN) 847 win = TCP_MAXWIN; 848 th->th_win = htons((u_int16_t)win); 849 th->th_off = sizeof (struct tcphdr) >> 2; 850 tlen += sizeof(*th); 851 } else 852 tlen += th->th_off << 2; 853 m->m_len = hlen + tlen; 854 m->m_pkthdr.len = hlen + tlen; 855 m->m_pkthdr.rcvif = NULL; 856 th->th_flags = flags; 857 th->th_urp = 0; 858 859 switch (family) { 860 #ifdef INET 861 case AF_INET: 862 { 863 struct ipovly *ipov = (struct ipovly *)ip; 864 memset(ipov->ih_x1, 0, sizeof ipov->ih_x1); 865 ipov->ih_len = htons((u_int16_t)tlen); 866 867 th->th_sum = 0; 868 th->th_sum = in_cksum(m, hlen + tlen); 869 ip->ip_len = htons(hlen + tlen); 870 ip->ip_ttl = ip_defttl; 871 break; 872 } 873 #endif 874 #ifdef INET6 875 case AF_INET6: 876 { 877 th->th_sum = 0; 878 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), 879 tlen); 880 ip6->ip6_plen = htons(tlen); 881 if (tp && tp->t_in6pcb) 882 ip6->ip6_hlim = in6_selecthlim_rt(tp->t_in6pcb); 883 else 884 ip6->ip6_hlim = ip6_defhlim; 885 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK; 886 if (ip6_auto_flowlabel) { 887 ip6->ip6_flow |= 888 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK); 889 } 890 break; 891 } 892 #endif 893 } 894 895 if (tp && tp->t_inpcb) 896 so = tp->t_inpcb->inp_socket; 897 #ifdef INET6 898 else if (tp && tp->t_in6pcb) 899 so = tp->t_in6pcb->in6p_socket; 900 #endif 901 else 902 so = NULL; 903 904 if (tp != NULL && tp->t_inpcb != NULL) { 905 ro = &tp->t_inpcb->inp_route; 906 #ifdef DIAGNOSTIC 907 if (family != AF_INET) 908 panic("tcp_respond: address family mismatch"); 909 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) { 910 panic("tcp_respond: ip_dst %x != inp_faddr %x", 911 ntohl(ip->ip_dst.s_addr), 912 ntohl(tp->t_inpcb->inp_faddr.s_addr)); 913 } 914 #endif 915 } 916 #ifdef INET6 917 else if (tp != NULL && tp->t_in6pcb != NULL) { 918 ro = (struct route *)&tp->t_in6pcb->in6p_route; 919 #ifdef DIAGNOSTIC 920 if (family == AF_INET) { 921 if (!IN6_IS_ADDR_V4MAPPED(&tp->t_in6pcb->in6p_faddr)) 922 panic("tcp_respond: not mapped addr"); 923 if (memcmp(&ip->ip_dst, 924 &tp->t_in6pcb->in6p_faddr.s6_addr32[3], 925 sizeof(ip->ip_dst)) != 0) { 926 panic("tcp_respond: ip_dst != in6p_faddr"); 927 } 928 } else if (family == AF_INET6) { 929 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 930 &tp->t_in6pcb->in6p_faddr)) 931 panic("tcp_respond: ip6_dst != in6p_faddr"); 932 } else 933 panic("tcp_respond: address family mismatch"); 934 #endif 935 } 936 #endif 937 else 938 ro = NULL; 939 940 switch (family) { 941 #ifdef INET 942 case AF_INET: 943 error = ip_output(m, NULL, ro, 944 (tp && tp->t_mtudisc ? IP_MTUDISC : 0), NULL, so); 945 break; 946 #endif 947 #ifdef INET6 948 case AF_INET6: 949 error = ip6_output(m, NULL, ro, 0, NULL, so, NULL); 950 break; 951 #endif 952 default: 953 error = EAFNOSUPPORT; 954 break; 955 } 956 957 return (error); 958 } 959 960 /* 961 * Template TCPCB. Rather than zeroing a new TCPCB and initializing 962 * a bunch of members individually, we maintain this template for the 963 * static and mostly-static components of the TCPCB, and copy it into 964 * the new TCPCB instead. 965 */ 966 static struct tcpcb tcpcb_template = { 967 .t_srtt = TCPTV_SRTTBASE, 968 .t_rttmin = TCPTV_MIN, 969 970 .snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT, 971 .snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT, 972 .snd_numholes = 0, 973 .snd_cubic_wmax = 0, 974 .snd_cubic_wmax_last = 0, 975 .snd_cubic_ctime = 0, 976 977 .t_partialacks = -1, 978 .t_bytes_acked = 0, 979 .t_sndrexmitpack = 0, 980 .t_rcvoopack = 0, 981 .t_sndzerowin = 0, 982 }; 983 984 /* 985 * Updates the TCPCB template whenever a parameter that would affect 986 * the template is changed. 987 */ 988 void 989 tcp_tcpcb_template(void) 990 { 991 struct tcpcb *tp = &tcpcb_template; 992 int flags; 993 994 tp->t_peermss = tcp_mssdflt; 995 tp->t_ourmss = tcp_mssdflt; 996 tp->t_segsz = tcp_mssdflt; 997 998 flags = 0; 999 if (tcp_do_rfc1323 && tcp_do_win_scale) 1000 flags |= TF_REQ_SCALE; 1001 if (tcp_do_rfc1323 && tcp_do_timestamps) 1002 flags |= TF_REQ_TSTMP; 1003 tp->t_flags = flags; 1004 1005 /* 1006 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1007 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 1008 * reasonable initial retransmit time. 1009 */ 1010 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1); 1011 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), 1012 TCPTV_MIN, TCPTV_REXMTMAX); 1013 1014 /* Keep Alive */ 1015 tp->t_keepinit = tcp_keepinit; 1016 tp->t_keepidle = tcp_keepidle; 1017 tp->t_keepintvl = tcp_keepintvl; 1018 tp->t_keepcnt = tcp_keepcnt; 1019 tp->t_maxidle = tp->t_keepcnt * tp->t_keepintvl; 1020 1021 /* MSL */ 1022 tp->t_msl = TCPTV_MSL; 1023 } 1024 1025 /* 1026 * Create a new TCP control block, making an 1027 * empty reassembly queue and hooking it to the argument 1028 * protocol control block. 1029 */ 1030 /* family selects inpcb, or in6pcb */ 1031 struct tcpcb * 1032 tcp_newtcpcb(int family, void *aux) 1033 { 1034 struct tcpcb *tp; 1035 int i; 1036 1037 /* XXX Consider using a pool_cache for speed. */ 1038 tp = pool_get(&tcpcb_pool, PR_NOWAIT); /* splsoftnet via tcp_usrreq */ 1039 if (tp == NULL) 1040 return (NULL); 1041 memcpy(tp, &tcpcb_template, sizeof(*tp)); 1042 TAILQ_INIT(&tp->segq); 1043 TAILQ_INIT(&tp->timeq); 1044 tp->t_family = family; /* may be overridden later on */ 1045 TAILQ_INIT(&tp->snd_holes); 1046 LIST_INIT(&tp->t_sc); /* XXX can template this */ 1047 1048 /* Don't sweat this loop; hopefully the compiler will unroll it. */ 1049 for (i = 0; i < TCPT_NTIMERS; i++) { 1050 callout_init(&tp->t_timer[i], CALLOUT_MPSAFE); 1051 TCP_TIMER_INIT(tp, i); 1052 } 1053 callout_init(&tp->t_delack_ch, CALLOUT_MPSAFE); 1054 1055 switch (family) { 1056 case AF_INET: 1057 { 1058 struct inpcb *inp = (struct inpcb *)aux; 1059 1060 inp->inp_ip.ip_ttl = ip_defttl; 1061 inp->inp_ppcb = (void *)tp; 1062 1063 tp->t_inpcb = inp; 1064 tp->t_mtudisc = ip_mtudisc; 1065 break; 1066 } 1067 #ifdef INET6 1068 case AF_INET6: 1069 { 1070 struct in6pcb *in6p = (struct in6pcb *)aux; 1071 1072 in6p->in6p_ip6.ip6_hlim = in6_selecthlim_rt(in6p); 1073 in6p->in6p_ppcb = (void *)tp; 1074 1075 tp->t_in6pcb = in6p; 1076 /* for IPv6, always try to run path MTU discovery */ 1077 tp->t_mtudisc = 1; 1078 break; 1079 } 1080 #endif /* INET6 */ 1081 default: 1082 for (i = 0; i < TCPT_NTIMERS; i++) 1083 callout_destroy(&tp->t_timer[i]); 1084 callout_destroy(&tp->t_delack_ch); 1085 pool_put(&tcpcb_pool, tp); /* splsoftnet via tcp_usrreq */ 1086 return (NULL); 1087 } 1088 1089 /* 1090 * Initialize our timebase. When we send timestamps, we take 1091 * the delta from tcp_now -- this means each connection always 1092 * gets a timebase of 1, which makes it, among other things, 1093 * more difficult to determine how long a system has been up, 1094 * and thus how many TCP sequence increments have occurred. 1095 * 1096 * We start with 1, because 0 doesn't work with linux, which 1097 * considers timestamp 0 in a SYN packet as a bug and disables 1098 * timestamps. 1099 */ 1100 tp->ts_timebase = tcp_now - 1; 1101 1102 tcp_congctl_select(tp, tcp_congctl_global_name); 1103 1104 return (tp); 1105 } 1106 1107 /* 1108 * Drop a TCP connection, reporting 1109 * the specified error. If connection is synchronized, 1110 * then send a RST to peer. 1111 */ 1112 struct tcpcb * 1113 tcp_drop(struct tcpcb *tp, int errno) 1114 { 1115 struct socket *so = NULL; 1116 1117 #ifdef DIAGNOSTIC 1118 if (tp->t_inpcb && tp->t_in6pcb) 1119 panic("tcp_drop: both t_inpcb and t_in6pcb are set"); 1120 #endif 1121 #ifdef INET 1122 if (tp->t_inpcb) 1123 so = tp->t_inpcb->inp_socket; 1124 #endif 1125 #ifdef INET6 1126 if (tp->t_in6pcb) 1127 so = tp->t_in6pcb->in6p_socket; 1128 #endif 1129 if (!so) 1130 return NULL; 1131 1132 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1133 tp->t_state = TCPS_CLOSED; 1134 (void) tcp_output(tp); 1135 TCP_STATINC(TCP_STAT_DROPS); 1136 } else 1137 TCP_STATINC(TCP_STAT_CONNDROPS); 1138 if (errno == ETIMEDOUT && tp->t_softerror) 1139 errno = tp->t_softerror; 1140 so->so_error = errno; 1141 return (tcp_close(tp)); 1142 } 1143 1144 /* 1145 * Close a TCP control block: 1146 * discard all space held by the tcp 1147 * discard internet protocol block 1148 * wake up any sleepers 1149 */ 1150 struct tcpcb * 1151 tcp_close(struct tcpcb *tp) 1152 { 1153 struct inpcb *inp; 1154 #ifdef INET6 1155 struct in6pcb *in6p; 1156 #endif 1157 struct socket *so; 1158 #ifdef RTV_RTT 1159 struct rtentry *rt; 1160 #endif 1161 struct route *ro; 1162 int j; 1163 1164 inp = tp->t_inpcb; 1165 #ifdef INET6 1166 in6p = tp->t_in6pcb; 1167 #endif 1168 so = NULL; 1169 ro = NULL; 1170 if (inp) { 1171 so = inp->inp_socket; 1172 ro = &inp->inp_route; 1173 } 1174 #ifdef INET6 1175 else if (in6p) { 1176 so = in6p->in6p_socket; 1177 ro = (struct route *)&in6p->in6p_route; 1178 } 1179 #endif 1180 1181 #ifdef RTV_RTT 1182 /* 1183 * If we sent enough data to get some meaningful characteristics, 1184 * save them in the routing entry. 'Enough' is arbitrarily 1185 * defined as the sendpipesize (default 4K) * 16. This would 1186 * give us 16 rtt samples assuming we only get one sample per 1187 * window (the usual case on a long haul net). 16 samples is 1188 * enough for the srtt filter to converge to within 5% of the correct 1189 * value; fewer samples and we could save a very bogus rtt. 1190 * 1191 * Don't update the default route's characteristics and don't 1192 * update anything that the user "locked". 1193 */ 1194 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 1195 ro && (rt = rtcache_validate(ro)) != NULL && 1196 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr)) { 1197 u_long i = 0; 1198 1199 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 1200 i = tp->t_srtt * 1201 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 1202 if (rt->rt_rmx.rmx_rtt && i) 1203 /* 1204 * filter this update to half the old & half 1205 * the new values, converting scale. 1206 * See route.h and tcp_var.h for a 1207 * description of the scaling constants. 1208 */ 1209 rt->rt_rmx.rmx_rtt = 1210 (rt->rt_rmx.rmx_rtt + i) / 2; 1211 else 1212 rt->rt_rmx.rmx_rtt = i; 1213 } 1214 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 1215 i = tp->t_rttvar * 1216 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2)); 1217 if (rt->rt_rmx.rmx_rttvar && i) 1218 rt->rt_rmx.rmx_rttvar = 1219 (rt->rt_rmx.rmx_rttvar + i) / 2; 1220 else 1221 rt->rt_rmx.rmx_rttvar = i; 1222 } 1223 /* 1224 * update the pipelimit (ssthresh) if it has been updated 1225 * already or if a pipesize was specified & the threshhold 1226 * got below half the pipesize. I.e., wait for bad news 1227 * before we start updating, then update on both good 1228 * and bad news. 1229 */ 1230 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 1231 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) || 1232 i < (rt->rt_rmx.rmx_sendpipe / 2)) { 1233 /* 1234 * convert the limit from user data bytes to 1235 * packets then to packet data bytes. 1236 */ 1237 i = (i + tp->t_segsz / 2) / tp->t_segsz; 1238 if (i < 2) 1239 i = 2; 1240 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr)); 1241 if (rt->rt_rmx.rmx_ssthresh) 1242 rt->rt_rmx.rmx_ssthresh = 1243 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1244 else 1245 rt->rt_rmx.rmx_ssthresh = i; 1246 } 1247 } 1248 #endif /* RTV_RTT */ 1249 /* free the reassembly queue, if any */ 1250 TCP_REASS_LOCK(tp); 1251 (void) tcp_freeq(tp); 1252 TCP_REASS_UNLOCK(tp); 1253 1254 /* free the SACK holes list. */ 1255 tcp_free_sackholes(tp); 1256 tcp_congctl_release(tp); 1257 syn_cache_cleanup(tp); 1258 1259 if (tp->t_template) { 1260 m_free(tp->t_template); 1261 tp->t_template = NULL; 1262 } 1263 1264 /* 1265 * Detaching the pcb will unlock the socket/tcpcb, and stopping 1266 * the timers can also drop the lock. We need to prevent access 1267 * to the tcpcb as it's half torn down. Flag the pcb as dead 1268 * (prevents access by timers) and only then detach it. 1269 */ 1270 tp->t_flags |= TF_DEAD; 1271 if (inp) { 1272 inp->inp_ppcb = 0; 1273 soisdisconnected(so); 1274 in_pcbdetach(inp); 1275 } 1276 #ifdef INET6 1277 else if (in6p) { 1278 in6p->in6p_ppcb = 0; 1279 soisdisconnected(so); 1280 in6_pcbdetach(in6p); 1281 } 1282 #endif 1283 /* 1284 * pcb is no longer visble elsewhere, so we can safely release 1285 * the lock in callout_halt() if needed. 1286 */ 1287 TCP_STATINC(TCP_STAT_CLOSED); 1288 for (j = 0; j < TCPT_NTIMERS; j++) { 1289 callout_halt(&tp->t_timer[j], softnet_lock); 1290 callout_destroy(&tp->t_timer[j]); 1291 } 1292 callout_halt(&tp->t_delack_ch, softnet_lock); 1293 callout_destroy(&tp->t_delack_ch); 1294 pool_put(&tcpcb_pool, tp); 1295 1296 return NULL; 1297 } 1298 1299 int 1300 tcp_freeq(struct tcpcb *tp) 1301 { 1302 struct ipqent *qe; 1303 int rv = 0; 1304 #ifdef TCPREASS_DEBUG 1305 int i = 0; 1306 #endif 1307 1308 TCP_REASS_LOCK_CHECK(tp); 1309 1310 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1311 #ifdef TCPREASS_DEBUG 1312 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1313 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1314 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1315 #endif 1316 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1317 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1318 m_freem(qe->ipqe_m); 1319 tcpipqent_free(qe); 1320 rv = 1; 1321 } 1322 tp->t_segqlen = 0; 1323 KASSERT(TAILQ_EMPTY(&tp->timeq)); 1324 return (rv); 1325 } 1326 1327 void 1328 tcp_fasttimo(void) 1329 { 1330 if (tcp_drainwanted) { 1331 tcp_drain(); 1332 tcp_drainwanted = 0; 1333 } 1334 } 1335 1336 void 1337 tcp_drainstub(void) 1338 { 1339 tcp_drainwanted = 1; 1340 } 1341 1342 /* 1343 * Protocol drain routine. Called when memory is in short supply. 1344 * Called from pr_fasttimo thus a callout context. 1345 */ 1346 void 1347 tcp_drain(void) 1348 { 1349 struct inpcb_hdr *inph; 1350 struct tcpcb *tp; 1351 1352 mutex_enter(softnet_lock); 1353 KERNEL_LOCK(1, NULL); 1354 1355 /* 1356 * Free the sequence queue of all TCP connections. 1357 */ 1358 TAILQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) { 1359 switch (inph->inph_af) { 1360 case AF_INET: 1361 tp = intotcpcb((struct inpcb *)inph); 1362 break; 1363 #ifdef INET6 1364 case AF_INET6: 1365 tp = in6totcpcb((struct in6pcb *)inph); 1366 break; 1367 #endif 1368 default: 1369 tp = NULL; 1370 break; 1371 } 1372 if (tp != NULL) { 1373 /* 1374 * We may be called from a device's interrupt 1375 * context. If the tcpcb is already busy, 1376 * just bail out now. 1377 */ 1378 if (tcp_reass_lock_try(tp) == 0) 1379 continue; 1380 if (tcp_freeq(tp)) 1381 TCP_STATINC(TCP_STAT_CONNSDRAINED); 1382 TCP_REASS_UNLOCK(tp); 1383 } 1384 } 1385 1386 KERNEL_UNLOCK_ONE(NULL); 1387 mutex_exit(softnet_lock); 1388 } 1389 1390 /* 1391 * Notify a tcp user of an asynchronous error; 1392 * store error as soft error, but wake up user 1393 * (for now, won't do anything until can select for soft error). 1394 */ 1395 void 1396 tcp_notify(struct inpcb *inp, int error) 1397 { 1398 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1399 struct socket *so = inp->inp_socket; 1400 1401 /* 1402 * Ignore some errors if we are hooked up. 1403 * If connection hasn't completed, has retransmitted several times, 1404 * and receives a second error, give up now. This is better 1405 * than waiting a long time to establish a connection that 1406 * can never complete. 1407 */ 1408 if (tp->t_state == TCPS_ESTABLISHED && 1409 (error == EHOSTUNREACH || error == ENETUNREACH || 1410 error == EHOSTDOWN)) { 1411 return; 1412 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1413 tp->t_rxtshift > 3 && tp->t_softerror) 1414 so->so_error = error; 1415 else 1416 tp->t_softerror = error; 1417 cv_broadcast(&so->so_cv); 1418 sorwakeup(so); 1419 sowwakeup(so); 1420 } 1421 1422 #ifdef INET6 1423 void 1424 tcp6_notify(struct in6pcb *in6p, int error) 1425 { 1426 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1427 struct socket *so = in6p->in6p_socket; 1428 1429 /* 1430 * Ignore some errors if we are hooked up. 1431 * If connection hasn't completed, has retransmitted several times, 1432 * and receives a second error, give up now. This is better 1433 * than waiting a long time to establish a connection that 1434 * can never complete. 1435 */ 1436 if (tp->t_state == TCPS_ESTABLISHED && 1437 (error == EHOSTUNREACH || error == ENETUNREACH || 1438 error == EHOSTDOWN)) { 1439 return; 1440 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1441 tp->t_rxtshift > 3 && tp->t_softerror) 1442 so->so_error = error; 1443 else 1444 tp->t_softerror = error; 1445 cv_broadcast(&so->so_cv); 1446 sorwakeup(so); 1447 sowwakeup(so); 1448 } 1449 #endif 1450 1451 #ifdef INET6 1452 void * 1453 tcp6_ctlinput(int cmd, const struct sockaddr *sa, void *d) 1454 { 1455 struct tcphdr th; 1456 void (*notify)(struct in6pcb *, int) = tcp6_notify; 1457 int nmatch; 1458 struct ip6_hdr *ip6; 1459 const struct sockaddr_in6 *sa6_src = NULL; 1460 const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa; 1461 struct mbuf *m; 1462 int off; 1463 1464 if (sa->sa_family != AF_INET6 || 1465 sa->sa_len != sizeof(struct sockaddr_in6)) 1466 return NULL; 1467 if ((unsigned)cmd >= PRC_NCMDS) 1468 return NULL; 1469 else if (cmd == PRC_QUENCH) { 1470 /* 1471 * Don't honor ICMP Source Quench messages meant for 1472 * TCP connections. 1473 */ 1474 return NULL; 1475 } else if (PRC_IS_REDIRECT(cmd)) 1476 notify = in6_rtchange, d = NULL; 1477 else if (cmd == PRC_MSGSIZE) 1478 ; /* special code is present, see below */ 1479 else if (cmd == PRC_HOSTDEAD) 1480 d = NULL; 1481 else if (inet6ctlerrmap[cmd] == 0) 1482 return NULL; 1483 1484 /* if the parameter is from icmp6, decode it. */ 1485 if (d != NULL) { 1486 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1487 m = ip6cp->ip6c_m; 1488 ip6 = ip6cp->ip6c_ip6; 1489 off = ip6cp->ip6c_off; 1490 sa6_src = ip6cp->ip6c_src; 1491 } else { 1492 m = NULL; 1493 ip6 = NULL; 1494 sa6_src = &sa6_any; 1495 off = 0; 1496 } 1497 1498 if (ip6) { 1499 /* 1500 * XXX: We assume that when ip6 is non NULL, 1501 * M and OFF are valid. 1502 */ 1503 1504 /* check if we can safely examine src and dst ports */ 1505 if (m->m_pkthdr.len < off + sizeof(th)) { 1506 if (cmd == PRC_MSGSIZE) 1507 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1508 return NULL; 1509 } 1510 1511 memset(&th, 0, sizeof(th)); 1512 m_copydata(m, off, sizeof(th), (void *)&th); 1513 1514 if (cmd == PRC_MSGSIZE) { 1515 int valid = 0; 1516 1517 /* 1518 * Check to see if we have a valid TCP connection 1519 * corresponding to the address in the ICMPv6 message 1520 * payload. 1521 */ 1522 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr, 1523 th.th_dport, 1524 (const struct in6_addr *)&sa6_src->sin6_addr, 1525 th.th_sport, 0, 0)) 1526 valid++; 1527 1528 /* 1529 * Depending on the value of "valid" and routing table 1530 * size (mtudisc_{hi,lo}wat), we will: 1531 * - recalcurate the new MTU and create the 1532 * corresponding routing entry, or 1533 * - ignore the MTU change notification. 1534 */ 1535 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1536 1537 /* 1538 * no need to call in6_pcbnotify, it should have been 1539 * called via callback if necessary 1540 */ 1541 return NULL; 1542 } 1543 1544 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport, 1545 (const struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1546 if (nmatch == 0 && syn_cache_count && 1547 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1548 inet6ctlerrmap[cmd] == ENETUNREACH || 1549 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1550 syn_cache_unreach((const struct sockaddr *)sa6_src, 1551 sa, &th); 1552 } else { 1553 (void) in6_pcbnotify(&tcbtable, sa, 0, 1554 (const struct sockaddr *)sa6_src, 0, cmd, NULL, notify); 1555 } 1556 1557 return NULL; 1558 } 1559 #endif 1560 1561 #ifdef INET 1562 /* assumes that ip header and tcp header are contiguous on mbuf */ 1563 void * 1564 tcp_ctlinput(int cmd, const struct sockaddr *sa, void *v) 1565 { 1566 struct ip *ip = v; 1567 struct tcphdr *th; 1568 struct icmp *icp; 1569 extern const int inetctlerrmap[]; 1570 void (*notify)(struct inpcb *, int) = tcp_notify; 1571 int errno; 1572 int nmatch; 1573 struct tcpcb *tp; 1574 u_int mtu; 1575 tcp_seq seq; 1576 struct inpcb *inp; 1577 #ifdef INET6 1578 struct in6pcb *in6p; 1579 struct in6_addr src6, dst6; 1580 #endif 1581 1582 if (sa->sa_family != AF_INET || 1583 sa->sa_len != sizeof(struct sockaddr_in)) 1584 return NULL; 1585 if ((unsigned)cmd >= PRC_NCMDS) 1586 return NULL; 1587 errno = inetctlerrmap[cmd]; 1588 if (cmd == PRC_QUENCH) 1589 /* 1590 * Don't honor ICMP Source Quench messages meant for 1591 * TCP connections. 1592 */ 1593 return NULL; 1594 else if (PRC_IS_REDIRECT(cmd)) 1595 notify = in_rtchange, ip = 0; 1596 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1597 /* 1598 * Check to see if we have a valid TCP connection 1599 * corresponding to the address in the ICMP message 1600 * payload. 1601 * 1602 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1603 */ 1604 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1605 #ifdef INET6 1606 memset(&src6, 0, sizeof(src6)); 1607 memset(&dst6, 0, sizeof(dst6)); 1608 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff; 1609 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr)); 1610 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr)); 1611 #endif 1612 if ((inp = in_pcblookup_connect(&tcbtable, ip->ip_dst, 1613 th->th_dport, ip->ip_src, th->th_sport, 0)) != NULL) 1614 #ifdef INET6 1615 in6p = NULL; 1616 #else 1617 ; 1618 #endif 1619 #ifdef INET6 1620 else if ((in6p = in6_pcblookup_connect(&tcbtable, &dst6, 1621 th->th_dport, &src6, th->th_sport, 0, 0)) != NULL) 1622 ; 1623 #endif 1624 else 1625 return NULL; 1626 1627 /* 1628 * Now that we've validated that we are actually communicating 1629 * with the host indicated in the ICMP message, locate the 1630 * ICMP header, recalculate the new MTU, and create the 1631 * corresponding routing entry. 1632 */ 1633 icp = (struct icmp *)((char *)ip - 1634 offsetof(struct icmp, icmp_ip)); 1635 if (inp) { 1636 if ((tp = intotcpcb(inp)) == NULL) 1637 return NULL; 1638 } 1639 #ifdef INET6 1640 else if (in6p) { 1641 if ((tp = in6totcpcb(in6p)) == NULL) 1642 return NULL; 1643 } 1644 #endif 1645 else 1646 return NULL; 1647 seq = ntohl(th->th_seq); 1648 if (SEQ_LT(seq, tp->snd_una) || SEQ_GT(seq, tp->snd_max)) 1649 return NULL; 1650 /* 1651 * If the ICMP message advertises a Next-Hop MTU 1652 * equal or larger than the maximum packet size we have 1653 * ever sent, drop the message. 1654 */ 1655 mtu = (u_int)ntohs(icp->icmp_nextmtu); 1656 if (mtu >= tp->t_pmtud_mtu_sent) 1657 return NULL; 1658 if (mtu >= tcp_hdrsz(tp) + tp->t_pmtud_mss_acked) { 1659 /* 1660 * Calculate new MTU, and create corresponding 1661 * route (traditional PMTUD). 1662 */ 1663 tp->t_flags &= ~TF_PMTUD_PEND; 1664 icmp_mtudisc(icp, ip->ip_dst); 1665 } else { 1666 /* 1667 * Record the information got in the ICMP 1668 * message; act on it later. 1669 * If we had already recorded an ICMP message, 1670 * replace the old one only if the new message 1671 * refers to an older TCP segment 1672 */ 1673 if (tp->t_flags & TF_PMTUD_PEND) { 1674 if (SEQ_LT(tp->t_pmtud_th_seq, seq)) 1675 return NULL; 1676 } else 1677 tp->t_flags |= TF_PMTUD_PEND; 1678 tp->t_pmtud_th_seq = seq; 1679 tp->t_pmtud_nextmtu = icp->icmp_nextmtu; 1680 tp->t_pmtud_ip_len = icp->icmp_ip.ip_len; 1681 tp->t_pmtud_ip_hl = icp->icmp_ip.ip_hl; 1682 } 1683 return NULL; 1684 } else if (cmd == PRC_HOSTDEAD) 1685 ip = 0; 1686 else if (errno == 0) 1687 return NULL; 1688 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1689 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1690 nmatch = in_pcbnotify(&tcbtable, satocsin(sa)->sin_addr, 1691 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1692 if (nmatch == 0 && syn_cache_count && 1693 (inetctlerrmap[cmd] == EHOSTUNREACH || 1694 inetctlerrmap[cmd] == ENETUNREACH || 1695 inetctlerrmap[cmd] == EHOSTDOWN)) { 1696 struct sockaddr_in sin; 1697 memset(&sin, 0, sizeof(sin)); 1698 sin.sin_len = sizeof(sin); 1699 sin.sin_family = AF_INET; 1700 sin.sin_port = th->th_sport; 1701 sin.sin_addr = ip->ip_src; 1702 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1703 } 1704 1705 /* XXX mapped address case */ 1706 } else 1707 in_pcbnotifyall(&tcbtable, satocsin(sa)->sin_addr, errno, 1708 notify); 1709 return NULL; 1710 } 1711 1712 /* 1713 * When a source quench is received, we are being notified of congestion. 1714 * Close the congestion window down to the Loss Window (one segment). 1715 * We will gradually open it again as we proceed. 1716 */ 1717 void 1718 tcp_quench(struct inpcb *inp, int errno) 1719 { 1720 struct tcpcb *tp = intotcpcb(inp); 1721 1722 if (tp) { 1723 tp->snd_cwnd = tp->t_segsz; 1724 tp->t_bytes_acked = 0; 1725 } 1726 } 1727 #endif 1728 1729 #ifdef INET6 1730 void 1731 tcp6_quench(struct in6pcb *in6p, int errno) 1732 { 1733 struct tcpcb *tp = in6totcpcb(in6p); 1734 1735 if (tp) { 1736 tp->snd_cwnd = tp->t_segsz; 1737 tp->t_bytes_acked = 0; 1738 } 1739 } 1740 #endif 1741 1742 #ifdef INET 1743 /* 1744 * Path MTU Discovery handlers. 1745 */ 1746 void 1747 tcp_mtudisc_callback(struct in_addr faddr) 1748 { 1749 #ifdef INET6 1750 struct in6_addr in6; 1751 #endif 1752 1753 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1754 #ifdef INET6 1755 memset(&in6, 0, sizeof(in6)); 1756 in6.s6_addr16[5] = 0xffff; 1757 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr)); 1758 tcp6_mtudisc_callback(&in6); 1759 #endif 1760 } 1761 1762 /* 1763 * On receipt of path MTU corrections, flush old route and replace it 1764 * with the new one. Retransmit all unacknowledged packets, to ensure 1765 * that all packets will be received. 1766 */ 1767 void 1768 tcp_mtudisc(struct inpcb *inp, int errno) 1769 { 1770 struct tcpcb *tp = intotcpcb(inp); 1771 struct rtentry *rt; 1772 1773 if (tp == NULL) 1774 return; 1775 1776 rt = in_pcbrtentry(inp); 1777 if (rt != NULL) { 1778 /* 1779 * If this was not a host route, remove and realloc. 1780 */ 1781 if ((rt->rt_flags & RTF_HOST) == 0) { 1782 in_rtchange(inp, errno); 1783 if ((rt = in_pcbrtentry(inp)) == NULL) 1784 return; 1785 } 1786 1787 /* 1788 * Slow start out of the error condition. We 1789 * use the MTU because we know it's smaller 1790 * than the previously transmitted segment. 1791 * 1792 * Note: This is more conservative than the 1793 * suggestion in draft-floyd-incr-init-win-03. 1794 */ 1795 if (rt->rt_rmx.rmx_mtu != 0) 1796 tp->snd_cwnd = 1797 TCP_INITIAL_WINDOW(tcp_init_win, 1798 rt->rt_rmx.rmx_mtu); 1799 } 1800 1801 /* 1802 * Resend unacknowledged packets. 1803 */ 1804 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1805 tcp_output(tp); 1806 } 1807 #endif /* INET */ 1808 1809 #ifdef INET6 1810 /* 1811 * Path MTU Discovery handlers. 1812 */ 1813 void 1814 tcp6_mtudisc_callback(struct in6_addr *faddr) 1815 { 1816 struct sockaddr_in6 sin6; 1817 1818 memset(&sin6, 0, sizeof(sin6)); 1819 sin6.sin6_family = AF_INET6; 1820 sin6.sin6_len = sizeof(struct sockaddr_in6); 1821 sin6.sin6_addr = *faddr; 1822 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0, 1823 (const struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1824 } 1825 1826 void 1827 tcp6_mtudisc(struct in6pcb *in6p, int errno) 1828 { 1829 struct tcpcb *tp = in6totcpcb(in6p); 1830 struct rtentry *rt = in6_pcbrtentry(in6p); 1831 1832 if (tp != 0) { 1833 if (rt != 0) { 1834 /* 1835 * If this was not a host route, remove and realloc. 1836 */ 1837 if ((rt->rt_flags & RTF_HOST) == 0) { 1838 in6_rtchange(in6p, errno); 1839 if ((rt = in6_pcbrtentry(in6p)) == 0) 1840 return; 1841 } 1842 1843 /* 1844 * Slow start out of the error condition. We 1845 * use the MTU because we know it's smaller 1846 * than the previously transmitted segment. 1847 * 1848 * Note: This is more conservative than the 1849 * suggestion in draft-floyd-incr-init-win-03. 1850 */ 1851 if (rt->rt_rmx.rmx_mtu != 0) 1852 tp->snd_cwnd = 1853 TCP_INITIAL_WINDOW(tcp_init_win, 1854 rt->rt_rmx.rmx_mtu); 1855 } 1856 1857 /* 1858 * Resend unacknowledged packets. 1859 */ 1860 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1861 tcp_output(tp); 1862 } 1863 } 1864 #endif /* INET6 */ 1865 1866 /* 1867 * Compute the MSS to advertise to the peer. Called only during 1868 * the 3-way handshake. If we are the server (peer initiated 1869 * connection), we are called with a pointer to the interface 1870 * on which the SYN packet arrived. If we are the client (we 1871 * initiated connection), we are called with a pointer to the 1872 * interface out which this connection should go. 1873 * 1874 * NOTE: Do not subtract IP option/extension header size nor IPsec 1875 * header size from MSS advertisement. MSS option must hold the maximum 1876 * segment size we can accept, so it must always be: 1877 * max(if mtu) - ip header - tcp header 1878 */ 1879 u_long 1880 tcp_mss_to_advertise(const struct ifnet *ifp, int af) 1881 { 1882 extern u_long in_maxmtu; 1883 u_long mss = 0; 1884 u_long hdrsiz; 1885 1886 /* 1887 * In order to avoid defeating path MTU discovery on the peer, 1888 * we advertise the max MTU of all attached networks as our MSS, 1889 * per RFC 1191, section 3.1. 1890 * 1891 * We provide the option to advertise just the MTU of 1892 * the interface on which we hope this connection will 1893 * be receiving. If we are responding to a SYN, we 1894 * will have a pretty good idea about this, but when 1895 * initiating a connection there is a bit more doubt. 1896 * 1897 * We also need to ensure that loopback has a large enough 1898 * MSS, as the loopback MTU is never included in in_maxmtu. 1899 */ 1900 1901 if (ifp != NULL) 1902 switch (af) { 1903 case AF_INET: 1904 mss = ifp->if_mtu; 1905 break; 1906 #ifdef INET6 1907 case AF_INET6: 1908 mss = IN6_LINKMTU(ifp); 1909 break; 1910 #endif 1911 } 1912 1913 if (tcp_mss_ifmtu == 0) 1914 switch (af) { 1915 case AF_INET: 1916 mss = max(in_maxmtu, mss); 1917 break; 1918 #ifdef INET6 1919 case AF_INET6: 1920 mss = max(in6_maxmtu, mss); 1921 break; 1922 #endif 1923 } 1924 1925 switch (af) { 1926 case AF_INET: 1927 hdrsiz = sizeof(struct ip); 1928 break; 1929 #ifdef INET6 1930 case AF_INET6: 1931 hdrsiz = sizeof(struct ip6_hdr); 1932 break; 1933 #endif 1934 default: 1935 hdrsiz = 0; 1936 break; 1937 } 1938 hdrsiz += sizeof(struct tcphdr); 1939 if (mss > hdrsiz) 1940 mss -= hdrsiz; 1941 1942 mss = max(tcp_mssdflt, mss); 1943 return (mss); 1944 } 1945 1946 /* 1947 * Set connection variables based on the peer's advertised MSS. 1948 * We are passed the TCPCB for the actual connection. If we 1949 * are the server, we are called by the compressed state engine 1950 * when the 3-way handshake is complete. If we are the client, 1951 * we are called when we receive the SYN,ACK from the server. 1952 * 1953 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1954 * before this routine is called! 1955 */ 1956 void 1957 tcp_mss_from_peer(struct tcpcb *tp, int offer) 1958 { 1959 struct socket *so; 1960 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1961 struct rtentry *rt; 1962 #endif 1963 u_long bufsize; 1964 int mss; 1965 1966 #ifdef DIAGNOSTIC 1967 if (tp->t_inpcb && tp->t_in6pcb) 1968 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1969 #endif 1970 so = NULL; 1971 rt = NULL; 1972 #ifdef INET 1973 if (tp->t_inpcb) { 1974 so = tp->t_inpcb->inp_socket; 1975 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1976 rt = in_pcbrtentry(tp->t_inpcb); 1977 #endif 1978 } 1979 #endif 1980 #ifdef INET6 1981 if (tp->t_in6pcb) { 1982 so = tp->t_in6pcb->in6p_socket; 1983 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1984 rt = in6_pcbrtentry(tp->t_in6pcb); 1985 #endif 1986 } 1987 #endif 1988 1989 /* 1990 * As per RFC1122, use the default MSS value, unless they 1991 * sent us an offer. Do not accept offers less than 256 bytes. 1992 */ 1993 mss = tcp_mssdflt; 1994 if (offer) 1995 mss = offer; 1996 mss = max(mss, 256); /* sanity */ 1997 tp->t_peermss = mss; 1998 mss -= tcp_optlen(tp); 1999 #ifdef INET 2000 if (tp->t_inpcb) 2001 mss -= ip_optlen(tp->t_inpcb); 2002 #endif 2003 #ifdef INET6 2004 if (tp->t_in6pcb) 2005 mss -= ip6_optlen(tp->t_in6pcb); 2006 #endif 2007 2008 /* 2009 * If there's a pipesize, change the socket buffer to that size. 2010 * Make the socket buffer an integral number of MSS units. If 2011 * the MSS is larger than the socket buffer, artificially decrease 2012 * the MSS. 2013 */ 2014 #ifdef RTV_SPIPE 2015 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 2016 bufsize = rt->rt_rmx.rmx_sendpipe; 2017 else 2018 #endif 2019 { 2020 KASSERT(so != NULL); 2021 bufsize = so->so_snd.sb_hiwat; 2022 } 2023 if (bufsize < mss) 2024 mss = bufsize; 2025 else { 2026 bufsize = roundup(bufsize, mss); 2027 if (bufsize > sb_max) 2028 bufsize = sb_max; 2029 (void) sbreserve(&so->so_snd, bufsize, so); 2030 } 2031 tp->t_segsz = mss; 2032 2033 #ifdef RTV_SSTHRESH 2034 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 2035 /* 2036 * There's some sort of gateway or interface buffer 2037 * limit on the path. Use this to set the slow 2038 * start threshold, but set the threshold to no less 2039 * than 2 * MSS. 2040 */ 2041 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 2042 } 2043 #endif 2044 } 2045 2046 /* 2047 * Processing necessary when a TCP connection is established. 2048 */ 2049 void 2050 tcp_established(struct tcpcb *tp) 2051 { 2052 struct socket *so; 2053 #ifdef RTV_RPIPE 2054 struct rtentry *rt; 2055 #endif 2056 u_long bufsize; 2057 2058 #ifdef DIAGNOSTIC 2059 if (tp->t_inpcb && tp->t_in6pcb) 2060 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 2061 #endif 2062 so = NULL; 2063 rt = NULL; 2064 #ifdef INET 2065 /* This is a while() to reduce the dreadful stairstepping below */ 2066 while (tp->t_inpcb) { 2067 so = tp->t_inpcb->inp_socket; 2068 #if defined(RTV_RPIPE) 2069 rt = in_pcbrtentry(tp->t_inpcb); 2070 #endif 2071 if (__predict_true(tcp_msl_enable)) { 2072 if (tp->t_inpcb->inp_laddr.s_addr == INADDR_LOOPBACK) { 2073 tp->t_msl = tcp_msl_loop ? tcp_msl_loop : (TCPTV_MSL >> 2); 2074 break; 2075 } 2076 2077 if (__predict_false(tcp_rttlocal)) { 2078 /* This may be adjusted by tcp_input */ 2079 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2080 break; 2081 } 2082 if (in_localaddr(tp->t_inpcb->inp_faddr)) { 2083 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2084 break; 2085 } 2086 } 2087 tp->t_msl = tcp_msl_remote ? tcp_msl_remote : TCPTV_MSL; 2088 break; 2089 } 2090 #endif 2091 #ifdef INET6 2092 /* The !tp->t_inpcb lets the compiler know it can't be v4 *and* v6 */ 2093 while (!tp->t_inpcb && tp->t_in6pcb) { 2094 so = tp->t_in6pcb->in6p_socket; 2095 #if defined(RTV_RPIPE) 2096 rt = in6_pcbrtentry(tp->t_in6pcb); 2097 #endif 2098 if (__predict_true(tcp_msl_enable)) { 2099 extern const struct in6_addr in6addr_loopback; 2100 2101 if (IN6_ARE_ADDR_EQUAL(&tp->t_in6pcb->in6p_laddr, 2102 &in6addr_loopback)) { 2103 tp->t_msl = tcp_msl_loop ? tcp_msl_loop : (TCPTV_MSL >> 2); 2104 break; 2105 } 2106 2107 if (__predict_false(tcp_rttlocal)) { 2108 /* This may be adjusted by tcp_input */ 2109 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2110 break; 2111 } 2112 if (in6_localaddr(&tp->t_in6pcb->in6p_faddr)) { 2113 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2114 break; 2115 } 2116 } 2117 tp->t_msl = tcp_msl_remote ? tcp_msl_remote : TCPTV_MSL; 2118 break; 2119 } 2120 #endif 2121 2122 tp->t_state = TCPS_ESTABLISHED; 2123 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle); 2124 2125 #ifdef RTV_RPIPE 2126 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 2127 bufsize = rt->rt_rmx.rmx_recvpipe; 2128 else 2129 #endif 2130 { 2131 KASSERT(so != NULL); 2132 bufsize = so->so_rcv.sb_hiwat; 2133 } 2134 if (bufsize > tp->t_ourmss) { 2135 bufsize = roundup(bufsize, tp->t_ourmss); 2136 if (bufsize > sb_max) 2137 bufsize = sb_max; 2138 (void) sbreserve(&so->so_rcv, bufsize, so); 2139 } 2140 } 2141 2142 /* 2143 * Check if there's an initial rtt or rttvar. Convert from the 2144 * route-table units to scaled multiples of the slow timeout timer. 2145 * Called only during the 3-way handshake. 2146 */ 2147 void 2148 tcp_rmx_rtt(struct tcpcb *tp) 2149 { 2150 #ifdef RTV_RTT 2151 struct rtentry *rt = NULL; 2152 int rtt; 2153 2154 #ifdef DIAGNOSTIC 2155 if (tp->t_inpcb && tp->t_in6pcb) 2156 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 2157 #endif 2158 #ifdef INET 2159 if (tp->t_inpcb) 2160 rt = in_pcbrtentry(tp->t_inpcb); 2161 #endif 2162 #ifdef INET6 2163 if (tp->t_in6pcb) 2164 rt = in6_pcbrtentry(tp->t_in6pcb); 2165 #endif 2166 if (rt == NULL) 2167 return; 2168 2169 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 2170 /* 2171 * XXX The lock bit for MTU indicates that the value 2172 * is also a minimum value; this is subject to time. 2173 */ 2174 if (rt->rt_rmx.rmx_locks & RTV_RTT) 2175 TCPT_RANGESET(tp->t_rttmin, 2176 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 2177 TCPTV_MIN, TCPTV_REXMTMAX); 2178 tp->t_srtt = rtt / 2179 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 2180 if (rt->rt_rmx.rmx_rttvar) { 2181 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 2182 ((RTM_RTTUNIT / PR_SLOWHZ) >> 2183 (TCP_RTTVAR_SHIFT + 2)); 2184 } else { 2185 /* Default variation is +- 1 rtt */ 2186 tp->t_rttvar = 2187 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 2188 } 2189 TCPT_RANGESET(tp->t_rxtcur, 2190 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 2191 tp->t_rttmin, TCPTV_REXMTMAX); 2192 } 2193 #endif 2194 } 2195 2196 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 2197 2198 /* 2199 * Get a new sequence value given a tcp control block 2200 */ 2201 tcp_seq 2202 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 2203 { 2204 2205 #ifdef INET 2206 if (tp->t_inpcb != NULL) { 2207 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 2208 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 2209 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 2210 addin)); 2211 } 2212 #endif 2213 #ifdef INET6 2214 if (tp->t_in6pcb != NULL) { 2215 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 2216 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 2217 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 2218 addin)); 2219 } 2220 #endif 2221 /* Not possible. */ 2222 panic("tcp_new_iss"); 2223 } 2224 2225 static u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 2226 2227 /* 2228 * Initialize RFC 1948 ISS Secret 2229 */ 2230 static int 2231 tcp_iss_secret_init(void) 2232 { 2233 cprng_strong(kern_cprng, 2234 tcp_iss_secret, sizeof(tcp_iss_secret), 0); 2235 2236 return 0; 2237 } 2238 2239 /* 2240 * This routine actually generates a new TCP initial sequence number. 2241 */ 2242 tcp_seq 2243 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2244 size_t addrsz, tcp_seq addin) 2245 { 2246 tcp_seq tcp_iss; 2247 2248 if (tcp_do_rfc1948) { 2249 MD5_CTX ctx; 2250 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2251 static ONCE_DECL(tcp_iss_secret_control); 2252 2253 /* 2254 * If we haven't been here before, initialize our cryptographic 2255 * hash secret. 2256 */ 2257 RUN_ONCE(&tcp_iss_secret_control, tcp_iss_secret_init); 2258 2259 /* 2260 * Compute the base value of the ISS. It is a hash 2261 * of (saddr, sport, daddr, dport, secret). 2262 */ 2263 MD5Init(&ctx); 2264 2265 MD5Update(&ctx, (u_char *) laddr, addrsz); 2266 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2267 2268 MD5Update(&ctx, (u_char *) faddr, addrsz); 2269 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2270 2271 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2272 2273 MD5Final(hash, &ctx); 2274 2275 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2276 2277 /* 2278 * Now increment our "timer", and add it in to 2279 * the computed value. 2280 * 2281 * XXX Use `addin'? 2282 * XXX TCP_ISSINCR too large to use? 2283 */ 2284 tcp_iss_seq += TCP_ISSINCR; 2285 #ifdef TCPISS_DEBUG 2286 printf("ISS hash 0x%08x, ", tcp_iss); 2287 #endif 2288 tcp_iss += tcp_iss_seq + addin; 2289 #ifdef TCPISS_DEBUG 2290 printf("new ISS 0x%08x\n", tcp_iss); 2291 #endif 2292 } else { 2293 /* 2294 * Randomize. 2295 */ 2296 tcp_iss = cprng_fast32(); 2297 2298 /* 2299 * If we were asked to add some amount to a known value, 2300 * we will take a random value obtained above, mask off 2301 * the upper bits, and add in the known value. We also 2302 * add in a constant to ensure that we are at least a 2303 * certain distance from the original value. 2304 * 2305 * This is used when an old connection is in timed wait 2306 * and we have a new one coming in, for instance. 2307 */ 2308 if (addin != 0) { 2309 #ifdef TCPISS_DEBUG 2310 printf("Random %08x, ", tcp_iss); 2311 #endif 2312 tcp_iss &= TCP_ISS_RANDOM_MASK; 2313 tcp_iss += addin + TCP_ISSINCR; 2314 #ifdef TCPISS_DEBUG 2315 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2316 #endif 2317 } else { 2318 tcp_iss &= TCP_ISS_RANDOM_MASK; 2319 tcp_iss += tcp_iss_seq; 2320 tcp_iss_seq += TCP_ISSINCR; 2321 #ifdef TCPISS_DEBUG 2322 printf("ISS %08x\n", tcp_iss); 2323 #endif 2324 } 2325 } 2326 2327 if (tcp_compat_42) { 2328 /* 2329 * Limit it to the positive range for really old TCP 2330 * implementations. 2331 * Just AND off the top bit instead of checking if 2332 * is set first - saves a branch 50% of the time. 2333 */ 2334 tcp_iss &= 0x7fffffff; /* XXX */ 2335 } 2336 2337 return (tcp_iss); 2338 } 2339 2340 #if defined(IPSEC) 2341 /* compute ESP/AH header size for TCP, including outer IP header. */ 2342 size_t 2343 ipsec4_hdrsiz_tcp(struct tcpcb *tp) 2344 { 2345 struct inpcb *inp; 2346 size_t hdrsiz; 2347 2348 /* XXX mapped addr case (tp->t_in6pcb) */ 2349 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2350 return 0; 2351 switch (tp->t_family) { 2352 case AF_INET: 2353 /* XXX: should use currect direction. */ 2354 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2355 break; 2356 default: 2357 hdrsiz = 0; 2358 break; 2359 } 2360 2361 return hdrsiz; 2362 } 2363 2364 #ifdef INET6 2365 size_t 2366 ipsec6_hdrsiz_tcp(struct tcpcb *tp) 2367 { 2368 struct in6pcb *in6p; 2369 size_t hdrsiz; 2370 2371 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2372 return 0; 2373 switch (tp->t_family) { 2374 case AF_INET6: 2375 /* XXX: should use currect direction. */ 2376 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2377 break; 2378 case AF_INET: 2379 /* mapped address case - tricky */ 2380 default: 2381 hdrsiz = 0; 2382 break; 2383 } 2384 2385 return hdrsiz; 2386 } 2387 #endif 2388 #endif /*IPSEC*/ 2389 2390 /* 2391 * Determine the length of the TCP options for this connection. 2392 * 2393 * XXX: What do we do for SACK, when we add that? Just reserve 2394 * all of the space? Otherwise we can't exactly be incrementing 2395 * cwnd by an amount that varies depending on the amount we last 2396 * had to SACK! 2397 */ 2398 2399 u_int 2400 tcp_optlen(struct tcpcb *tp) 2401 { 2402 u_int optlen; 2403 2404 optlen = 0; 2405 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2406 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2407 optlen += TCPOLEN_TSTAMP_APPA; 2408 2409 #ifdef TCP_SIGNATURE 2410 if (tp->t_flags & TF_SIGNATURE) 2411 optlen += TCPOLEN_SIGNATURE + 2; 2412 #endif /* TCP_SIGNATURE */ 2413 2414 return optlen; 2415 } 2416 2417 u_int 2418 tcp_hdrsz(struct tcpcb *tp) 2419 { 2420 u_int hlen; 2421 2422 switch (tp->t_family) { 2423 #ifdef INET6 2424 case AF_INET6: 2425 hlen = sizeof(struct ip6_hdr); 2426 break; 2427 #endif 2428 case AF_INET: 2429 hlen = sizeof(struct ip); 2430 break; 2431 default: 2432 hlen = 0; 2433 break; 2434 } 2435 hlen += sizeof(struct tcphdr); 2436 2437 if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && 2438 (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP) 2439 hlen += TCPOLEN_TSTAMP_APPA; 2440 #ifdef TCP_SIGNATURE 2441 if (tp->t_flags & TF_SIGNATURE) 2442 hlen += TCPOLEN_SIGLEN; 2443 #endif 2444 return hlen; 2445 } 2446 2447 void 2448 tcp_statinc(u_int stat) 2449 { 2450 2451 KASSERT(stat < TCP_NSTATS); 2452 TCP_STATINC(stat); 2453 } 2454 2455 void 2456 tcp_statadd(u_int stat, uint64_t val) 2457 { 2458 2459 KASSERT(stat < TCP_NSTATS); 2460 TCP_STATADD(stat, val); 2461 } 2462