tcp_subr.c revision 1.268
1 /* $NetBSD: tcp_subr.c,v 1.268 2016/12/08 05:16:33 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 1.268 2016/12/08 05:16:33 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_reset_rcvif(m); 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 = NULL; 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 rtcache_unref(rt, ro); 1249 #endif /* RTV_RTT */ 1250 /* free the reassembly queue, if any */ 1251 TCP_REASS_LOCK(tp); 1252 (void) tcp_freeq(tp); 1253 TCP_REASS_UNLOCK(tp); 1254 1255 /* free the SACK holes list. */ 1256 tcp_free_sackholes(tp); 1257 tcp_congctl_release(tp); 1258 syn_cache_cleanup(tp); 1259 1260 if (tp->t_template) { 1261 m_free(tp->t_template); 1262 tp->t_template = NULL; 1263 } 1264 1265 /* 1266 * Detaching the pcb will unlock the socket/tcpcb, and stopping 1267 * the timers can also drop the lock. We need to prevent access 1268 * to the tcpcb as it's half torn down. Flag the pcb as dead 1269 * (prevents access by timers) and only then detach it. 1270 */ 1271 tp->t_flags |= TF_DEAD; 1272 if (inp) { 1273 inp->inp_ppcb = 0; 1274 soisdisconnected(so); 1275 in_pcbdetach(inp); 1276 } 1277 #ifdef INET6 1278 else if (in6p) { 1279 in6p->in6p_ppcb = 0; 1280 soisdisconnected(so); 1281 in6_pcbdetach(in6p); 1282 } 1283 #endif 1284 /* 1285 * pcb is no longer visble elsewhere, so we can safely release 1286 * the lock in callout_halt() if needed. 1287 */ 1288 TCP_STATINC(TCP_STAT_CLOSED); 1289 for (j = 0; j < TCPT_NTIMERS; j++) { 1290 callout_halt(&tp->t_timer[j], softnet_lock); 1291 callout_destroy(&tp->t_timer[j]); 1292 } 1293 callout_halt(&tp->t_delack_ch, softnet_lock); 1294 callout_destroy(&tp->t_delack_ch); 1295 pool_put(&tcpcb_pool, tp); 1296 1297 return NULL; 1298 } 1299 1300 int 1301 tcp_freeq(struct tcpcb *tp) 1302 { 1303 struct ipqent *qe; 1304 int rv = 0; 1305 #ifdef TCPREASS_DEBUG 1306 int i = 0; 1307 #endif 1308 1309 TCP_REASS_LOCK_CHECK(tp); 1310 1311 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) { 1312 #ifdef TCPREASS_DEBUG 1313 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n", 1314 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len, 1315 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST)); 1316 #endif 1317 TAILQ_REMOVE(&tp->segq, qe, ipqe_q); 1318 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq); 1319 m_freem(qe->ipqe_m); 1320 tcpipqent_free(qe); 1321 rv = 1; 1322 } 1323 tp->t_segqlen = 0; 1324 KASSERT(TAILQ_EMPTY(&tp->timeq)); 1325 return (rv); 1326 } 1327 1328 void 1329 tcp_fasttimo(void) 1330 { 1331 if (tcp_drainwanted) { 1332 tcp_drain(); 1333 tcp_drainwanted = 0; 1334 } 1335 } 1336 1337 void 1338 tcp_drainstub(void) 1339 { 1340 tcp_drainwanted = 1; 1341 } 1342 1343 /* 1344 * Protocol drain routine. Called when memory is in short supply. 1345 * Called from pr_fasttimo thus a callout context. 1346 */ 1347 void 1348 tcp_drain(void) 1349 { 1350 struct inpcb_hdr *inph; 1351 struct tcpcb *tp; 1352 1353 mutex_enter(softnet_lock); 1354 KERNEL_LOCK(1, NULL); 1355 1356 /* 1357 * Free the sequence queue of all TCP connections. 1358 */ 1359 TAILQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) { 1360 switch (inph->inph_af) { 1361 case AF_INET: 1362 tp = intotcpcb((struct inpcb *)inph); 1363 break; 1364 #ifdef INET6 1365 case AF_INET6: 1366 tp = in6totcpcb((struct in6pcb *)inph); 1367 break; 1368 #endif 1369 default: 1370 tp = NULL; 1371 break; 1372 } 1373 if (tp != NULL) { 1374 /* 1375 * We may be called from a device's interrupt 1376 * context. If the tcpcb is already busy, 1377 * just bail out now. 1378 */ 1379 if (tcp_reass_lock_try(tp) == 0) 1380 continue; 1381 if (tcp_freeq(tp)) 1382 TCP_STATINC(TCP_STAT_CONNSDRAINED); 1383 TCP_REASS_UNLOCK(tp); 1384 } 1385 } 1386 1387 KERNEL_UNLOCK_ONE(NULL); 1388 mutex_exit(softnet_lock); 1389 } 1390 1391 /* 1392 * Notify a tcp user of an asynchronous error; 1393 * store error as soft error, but wake up user 1394 * (for now, won't do anything until can select for soft error). 1395 */ 1396 void 1397 tcp_notify(struct inpcb *inp, int error) 1398 { 1399 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 1400 struct socket *so = inp->inp_socket; 1401 1402 /* 1403 * Ignore some errors if we are hooked up. 1404 * If connection hasn't completed, has retransmitted several times, 1405 * and receives a second error, give up now. This is better 1406 * than waiting a long time to establish a connection that 1407 * can never complete. 1408 */ 1409 if (tp->t_state == TCPS_ESTABLISHED && 1410 (error == EHOSTUNREACH || error == ENETUNREACH || 1411 error == EHOSTDOWN)) { 1412 return; 1413 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1414 tp->t_rxtshift > 3 && tp->t_softerror) 1415 so->so_error = error; 1416 else 1417 tp->t_softerror = error; 1418 cv_broadcast(&so->so_cv); 1419 sorwakeup(so); 1420 sowwakeup(so); 1421 } 1422 1423 #ifdef INET6 1424 void 1425 tcp6_notify(struct in6pcb *in6p, int error) 1426 { 1427 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb; 1428 struct socket *so = in6p->in6p_socket; 1429 1430 /* 1431 * Ignore some errors if we are hooked up. 1432 * If connection hasn't completed, has retransmitted several times, 1433 * and receives a second error, give up now. This is better 1434 * than waiting a long time to establish a connection that 1435 * can never complete. 1436 */ 1437 if (tp->t_state == TCPS_ESTABLISHED && 1438 (error == EHOSTUNREACH || error == ENETUNREACH || 1439 error == EHOSTDOWN)) { 1440 return; 1441 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 && 1442 tp->t_rxtshift > 3 && tp->t_softerror) 1443 so->so_error = error; 1444 else 1445 tp->t_softerror = error; 1446 cv_broadcast(&so->so_cv); 1447 sorwakeup(so); 1448 sowwakeup(so); 1449 } 1450 #endif 1451 1452 #ifdef INET6 1453 void * 1454 tcp6_ctlinput(int cmd, const struct sockaddr *sa, void *d) 1455 { 1456 struct tcphdr th; 1457 void (*notify)(struct in6pcb *, int) = tcp6_notify; 1458 int nmatch; 1459 struct ip6_hdr *ip6; 1460 const struct sockaddr_in6 *sa6_src = NULL; 1461 const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa; 1462 struct mbuf *m; 1463 int off; 1464 1465 if (sa->sa_family != AF_INET6 || 1466 sa->sa_len != sizeof(struct sockaddr_in6)) 1467 return NULL; 1468 if ((unsigned)cmd >= PRC_NCMDS) 1469 return NULL; 1470 else if (cmd == PRC_QUENCH) { 1471 /* 1472 * Don't honor ICMP Source Quench messages meant for 1473 * TCP connections. 1474 */ 1475 return NULL; 1476 } else if (PRC_IS_REDIRECT(cmd)) 1477 notify = in6_rtchange, d = NULL; 1478 else if (cmd == PRC_MSGSIZE) 1479 ; /* special code is present, see below */ 1480 else if (cmd == PRC_HOSTDEAD) 1481 d = NULL; 1482 else if (inet6ctlerrmap[cmd] == 0) 1483 return NULL; 1484 1485 /* if the parameter is from icmp6, decode it. */ 1486 if (d != NULL) { 1487 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1488 m = ip6cp->ip6c_m; 1489 ip6 = ip6cp->ip6c_ip6; 1490 off = ip6cp->ip6c_off; 1491 sa6_src = ip6cp->ip6c_src; 1492 } else { 1493 m = NULL; 1494 ip6 = NULL; 1495 sa6_src = &sa6_any; 1496 off = 0; 1497 } 1498 1499 if (ip6) { 1500 /* 1501 * XXX: We assume that when ip6 is non NULL, 1502 * M and OFF are valid. 1503 */ 1504 1505 /* check if we can safely examine src and dst ports */ 1506 if (m->m_pkthdr.len < off + sizeof(th)) { 1507 if (cmd == PRC_MSGSIZE) 1508 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0); 1509 return NULL; 1510 } 1511 1512 memset(&th, 0, sizeof(th)); 1513 m_copydata(m, off, sizeof(th), (void *)&th); 1514 1515 if (cmd == PRC_MSGSIZE) { 1516 int valid = 0; 1517 1518 /* 1519 * Check to see if we have a valid TCP connection 1520 * corresponding to the address in the ICMPv6 message 1521 * payload. 1522 */ 1523 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr, 1524 th.th_dport, 1525 (const struct in6_addr *)&sa6_src->sin6_addr, 1526 th.th_sport, 0, 0)) 1527 valid++; 1528 1529 /* 1530 * Depending on the value of "valid" and routing table 1531 * size (mtudisc_{hi,lo}wat), we will: 1532 * - recalcurate the new MTU and create the 1533 * corresponding routing entry, or 1534 * - ignore the MTU change notification. 1535 */ 1536 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid); 1537 1538 /* 1539 * no need to call in6_pcbnotify, it should have been 1540 * called via callback if necessary 1541 */ 1542 return NULL; 1543 } 1544 1545 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport, 1546 (const struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify); 1547 if (nmatch == 0 && syn_cache_count && 1548 (inet6ctlerrmap[cmd] == EHOSTUNREACH || 1549 inet6ctlerrmap[cmd] == ENETUNREACH || 1550 inet6ctlerrmap[cmd] == EHOSTDOWN)) 1551 syn_cache_unreach((const struct sockaddr *)sa6_src, 1552 sa, &th); 1553 } else { 1554 (void) in6_pcbnotify(&tcbtable, sa, 0, 1555 (const struct sockaddr *)sa6_src, 0, cmd, NULL, notify); 1556 } 1557 1558 return NULL; 1559 } 1560 #endif 1561 1562 #ifdef INET 1563 /* assumes that ip header and tcp header are contiguous on mbuf */ 1564 void * 1565 tcp_ctlinput(int cmd, const struct sockaddr *sa, void *v) 1566 { 1567 struct ip *ip = v; 1568 struct tcphdr *th; 1569 struct icmp *icp; 1570 extern const int inetctlerrmap[]; 1571 void (*notify)(struct inpcb *, int) = tcp_notify; 1572 int errno; 1573 int nmatch; 1574 struct tcpcb *tp; 1575 u_int mtu; 1576 tcp_seq seq; 1577 struct inpcb *inp; 1578 #ifdef INET6 1579 struct in6pcb *in6p; 1580 struct in6_addr src6, dst6; 1581 #endif 1582 1583 if (sa->sa_family != AF_INET || 1584 sa->sa_len != sizeof(struct sockaddr_in)) 1585 return NULL; 1586 if ((unsigned)cmd >= PRC_NCMDS) 1587 return NULL; 1588 errno = inetctlerrmap[cmd]; 1589 if (cmd == PRC_QUENCH) 1590 /* 1591 * Don't honor ICMP Source Quench messages meant for 1592 * TCP connections. 1593 */ 1594 return NULL; 1595 else if (PRC_IS_REDIRECT(cmd)) 1596 notify = in_rtchange, ip = 0; 1597 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) { 1598 /* 1599 * Check to see if we have a valid TCP connection 1600 * corresponding to the address in the ICMP message 1601 * payload. 1602 * 1603 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN. 1604 */ 1605 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1606 #ifdef INET6 1607 in6_in_2_v4mapin6(&ip->ip_src, &src6); 1608 in6_in_2_v4mapin6(&ip->ip_dst, &dst6); 1609 #endif 1610 if ((inp = in_pcblookup_connect(&tcbtable, ip->ip_dst, 1611 th->th_dport, ip->ip_src, th->th_sport, 0)) != NULL) 1612 #ifdef INET6 1613 in6p = NULL; 1614 #else 1615 ; 1616 #endif 1617 #ifdef INET6 1618 else if ((in6p = in6_pcblookup_connect(&tcbtable, &dst6, 1619 th->th_dport, &src6, th->th_sport, 0, 0)) != NULL) 1620 ; 1621 #endif 1622 else 1623 return NULL; 1624 1625 /* 1626 * Now that we've validated that we are actually communicating 1627 * with the host indicated in the ICMP message, locate the 1628 * ICMP header, recalculate the new MTU, and create the 1629 * corresponding routing entry. 1630 */ 1631 icp = (struct icmp *)((char *)ip - 1632 offsetof(struct icmp, icmp_ip)); 1633 if (inp) { 1634 if ((tp = intotcpcb(inp)) == NULL) 1635 return NULL; 1636 } 1637 #ifdef INET6 1638 else if (in6p) { 1639 if ((tp = in6totcpcb(in6p)) == NULL) 1640 return NULL; 1641 } 1642 #endif 1643 else 1644 return NULL; 1645 seq = ntohl(th->th_seq); 1646 if (SEQ_LT(seq, tp->snd_una) || SEQ_GT(seq, tp->snd_max)) 1647 return NULL; 1648 /* 1649 * If the ICMP message advertises a Next-Hop MTU 1650 * equal or larger than the maximum packet size we have 1651 * ever sent, drop the message. 1652 */ 1653 mtu = (u_int)ntohs(icp->icmp_nextmtu); 1654 if (mtu >= tp->t_pmtud_mtu_sent) 1655 return NULL; 1656 if (mtu >= tcp_hdrsz(tp) + tp->t_pmtud_mss_acked) { 1657 /* 1658 * Calculate new MTU, and create corresponding 1659 * route (traditional PMTUD). 1660 */ 1661 tp->t_flags &= ~TF_PMTUD_PEND; 1662 icmp_mtudisc(icp, ip->ip_dst); 1663 } else { 1664 /* 1665 * Record the information got in the ICMP 1666 * message; act on it later. 1667 * If we had already recorded an ICMP message, 1668 * replace the old one only if the new message 1669 * refers to an older TCP segment 1670 */ 1671 if (tp->t_flags & TF_PMTUD_PEND) { 1672 if (SEQ_LT(tp->t_pmtud_th_seq, seq)) 1673 return NULL; 1674 } else 1675 tp->t_flags |= TF_PMTUD_PEND; 1676 tp->t_pmtud_th_seq = seq; 1677 tp->t_pmtud_nextmtu = icp->icmp_nextmtu; 1678 tp->t_pmtud_ip_len = icp->icmp_ip.ip_len; 1679 tp->t_pmtud_ip_hl = icp->icmp_ip.ip_hl; 1680 } 1681 return NULL; 1682 } else if (cmd == PRC_HOSTDEAD) 1683 ip = 0; 1684 else if (errno == 0) 1685 return NULL; 1686 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) { 1687 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2)); 1688 nmatch = in_pcbnotify(&tcbtable, satocsin(sa)->sin_addr, 1689 th->th_dport, ip->ip_src, th->th_sport, errno, notify); 1690 if (nmatch == 0 && syn_cache_count && 1691 (inetctlerrmap[cmd] == EHOSTUNREACH || 1692 inetctlerrmap[cmd] == ENETUNREACH || 1693 inetctlerrmap[cmd] == EHOSTDOWN)) { 1694 struct sockaddr_in sin; 1695 memset(&sin, 0, sizeof(sin)); 1696 sin.sin_len = sizeof(sin); 1697 sin.sin_family = AF_INET; 1698 sin.sin_port = th->th_sport; 1699 sin.sin_addr = ip->ip_src; 1700 syn_cache_unreach((struct sockaddr *)&sin, sa, th); 1701 } 1702 1703 /* XXX mapped address case */ 1704 } else 1705 in_pcbnotifyall(&tcbtable, satocsin(sa)->sin_addr, errno, 1706 notify); 1707 return NULL; 1708 } 1709 1710 /* 1711 * When a source quench is received, we are being notified of congestion. 1712 * Close the congestion window down to the Loss Window (one segment). 1713 * We will gradually open it again as we proceed. 1714 */ 1715 void 1716 tcp_quench(struct inpcb *inp, int errno) 1717 { 1718 struct tcpcb *tp = intotcpcb(inp); 1719 1720 if (tp) { 1721 tp->snd_cwnd = tp->t_segsz; 1722 tp->t_bytes_acked = 0; 1723 } 1724 } 1725 #endif 1726 1727 #ifdef INET6 1728 void 1729 tcp6_quench(struct in6pcb *in6p, int errno) 1730 { 1731 struct tcpcb *tp = in6totcpcb(in6p); 1732 1733 if (tp) { 1734 tp->snd_cwnd = tp->t_segsz; 1735 tp->t_bytes_acked = 0; 1736 } 1737 } 1738 #endif 1739 1740 #ifdef INET 1741 /* 1742 * Path MTU Discovery handlers. 1743 */ 1744 void 1745 tcp_mtudisc_callback(struct in_addr faddr) 1746 { 1747 #ifdef INET6 1748 struct in6_addr in6; 1749 #endif 1750 1751 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc); 1752 #ifdef INET6 1753 in6_in_2_v4mapin6(&faddr, &in6); 1754 tcp6_mtudisc_callback(&in6); 1755 #endif 1756 } 1757 1758 /* 1759 * On receipt of path MTU corrections, flush old route and replace it 1760 * with the new one. Retransmit all unacknowledged packets, to ensure 1761 * that all packets will be received. 1762 */ 1763 void 1764 tcp_mtudisc(struct inpcb *inp, int errno) 1765 { 1766 struct tcpcb *tp = intotcpcb(inp); 1767 struct rtentry *rt; 1768 1769 if (tp == NULL) 1770 return; 1771 1772 rt = in_pcbrtentry(inp); 1773 if (rt != NULL) { 1774 /* 1775 * If this was not a host route, remove and realloc. 1776 */ 1777 if ((rt->rt_flags & RTF_HOST) == 0) { 1778 in_pcbrtentry_unref(rt, inp); 1779 in_rtchange(inp, errno); 1780 if ((rt = in_pcbrtentry(inp)) == NULL) 1781 return; 1782 } 1783 1784 /* 1785 * Slow start out of the error condition. We 1786 * use the MTU because we know it's smaller 1787 * than the previously transmitted segment. 1788 * 1789 * Note: This is more conservative than the 1790 * suggestion in draft-floyd-incr-init-win-03. 1791 */ 1792 if (rt->rt_rmx.rmx_mtu != 0) 1793 tp->snd_cwnd = 1794 TCP_INITIAL_WINDOW(tcp_init_win, 1795 rt->rt_rmx.rmx_mtu); 1796 in_pcbrtentry_unref(rt, inp); 1797 } 1798 1799 /* 1800 * Resend unacknowledged packets. 1801 */ 1802 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1803 tcp_output(tp); 1804 } 1805 #endif /* INET */ 1806 1807 #ifdef INET6 1808 /* 1809 * Path MTU Discovery handlers. 1810 */ 1811 void 1812 tcp6_mtudisc_callback(struct in6_addr *faddr) 1813 { 1814 struct sockaddr_in6 sin6; 1815 1816 memset(&sin6, 0, sizeof(sin6)); 1817 sin6.sin6_family = AF_INET6; 1818 sin6.sin6_len = sizeof(struct sockaddr_in6); 1819 sin6.sin6_addr = *faddr; 1820 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0, 1821 (const struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc); 1822 } 1823 1824 void 1825 tcp6_mtudisc(struct in6pcb *in6p, int errno) 1826 { 1827 struct tcpcb *tp = in6totcpcb(in6p); 1828 struct rtentry *rt; 1829 1830 if (tp == NULL) 1831 return; 1832 1833 rt = in6_pcbrtentry(in6p); 1834 if (rt != NULL) { 1835 /* 1836 * If this was not a host route, remove and realloc. 1837 */ 1838 if ((rt->rt_flags & RTF_HOST) == 0) { 1839 in6_pcbrtentry_unref(rt, in6p); 1840 in6_rtchange(in6p, errno); 1841 rt = in6_pcbrtentry(in6p); 1842 if (rt == NULL) 1843 return; 1844 } 1845 1846 /* 1847 * Slow start out of the error condition. We 1848 * use the MTU because we know it's smaller 1849 * than the previously transmitted segment. 1850 * 1851 * Note: This is more conservative than the 1852 * suggestion in draft-floyd-incr-init-win-03. 1853 */ 1854 if (rt->rt_rmx.rmx_mtu != 0) { 1855 tp->snd_cwnd = TCP_INITIAL_WINDOW(tcp_init_win, 1856 rt->rt_rmx.rmx_mtu); 1857 } 1858 in6_pcbrtentry_unref(rt, in6p); 1859 } 1860 1861 /* 1862 * Resend unacknowledged packets. 1863 */ 1864 tp->snd_nxt = tp->sack_newdata = tp->snd_una; 1865 tcp_output(tp); 1866 } 1867 #endif /* INET6 */ 1868 1869 /* 1870 * Compute the MSS to advertise to the peer. Called only during 1871 * the 3-way handshake. If we are the server (peer initiated 1872 * connection), we are called with a pointer to the interface 1873 * on which the SYN packet arrived. If we are the client (we 1874 * initiated connection), we are called with a pointer to the 1875 * interface out which this connection should go. 1876 * 1877 * NOTE: Do not subtract IP option/extension header size nor IPsec 1878 * header size from MSS advertisement. MSS option must hold the maximum 1879 * segment size we can accept, so it must always be: 1880 * max(if mtu) - ip header - tcp header 1881 */ 1882 u_long 1883 tcp_mss_to_advertise(const struct ifnet *ifp, int af) 1884 { 1885 extern u_long in_maxmtu; 1886 u_long mss = 0; 1887 u_long hdrsiz; 1888 1889 /* 1890 * In order to avoid defeating path MTU discovery on the peer, 1891 * we advertise the max MTU of all attached networks as our MSS, 1892 * per RFC 1191, section 3.1. 1893 * 1894 * We provide the option to advertise just the MTU of 1895 * the interface on which we hope this connection will 1896 * be receiving. If we are responding to a SYN, we 1897 * will have a pretty good idea about this, but when 1898 * initiating a connection there is a bit more doubt. 1899 * 1900 * We also need to ensure that loopback has a large enough 1901 * MSS, as the loopback MTU is never included in in_maxmtu. 1902 */ 1903 1904 if (ifp != NULL) 1905 switch (af) { 1906 case AF_INET: 1907 mss = ifp->if_mtu; 1908 break; 1909 #ifdef INET6 1910 case AF_INET6: 1911 mss = IN6_LINKMTU(ifp); 1912 break; 1913 #endif 1914 } 1915 1916 if (tcp_mss_ifmtu == 0) 1917 switch (af) { 1918 case AF_INET: 1919 mss = max(in_maxmtu, mss); 1920 break; 1921 #ifdef INET6 1922 case AF_INET6: 1923 mss = max(in6_maxmtu, mss); 1924 break; 1925 #endif 1926 } 1927 1928 switch (af) { 1929 case AF_INET: 1930 hdrsiz = sizeof(struct ip); 1931 break; 1932 #ifdef INET6 1933 case AF_INET6: 1934 hdrsiz = sizeof(struct ip6_hdr); 1935 break; 1936 #endif 1937 default: 1938 hdrsiz = 0; 1939 break; 1940 } 1941 hdrsiz += sizeof(struct tcphdr); 1942 if (mss > hdrsiz) 1943 mss -= hdrsiz; 1944 1945 mss = max(tcp_mssdflt, mss); 1946 return (mss); 1947 } 1948 1949 /* 1950 * Set connection variables based on the peer's advertised MSS. 1951 * We are passed the TCPCB for the actual connection. If we 1952 * are the server, we are called by the compressed state engine 1953 * when the 3-way handshake is complete. If we are the client, 1954 * we are called when we receive the SYN,ACK from the server. 1955 * 1956 * NOTE: Our advertised MSS value must be initialized in the TCPCB 1957 * before this routine is called! 1958 */ 1959 void 1960 tcp_mss_from_peer(struct tcpcb *tp, int offer) 1961 { 1962 struct socket *so; 1963 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1964 struct rtentry *rt; 1965 #endif 1966 u_long bufsize; 1967 int mss; 1968 1969 #ifdef DIAGNOSTIC 1970 if (tp->t_inpcb && tp->t_in6pcb) 1971 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set"); 1972 #endif 1973 so = NULL; 1974 rt = NULL; 1975 #ifdef INET 1976 if (tp->t_inpcb) { 1977 so = tp->t_inpcb->inp_socket; 1978 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1979 rt = in_pcbrtentry(tp->t_inpcb); 1980 #endif 1981 } 1982 #endif 1983 #ifdef INET6 1984 if (tp->t_in6pcb) { 1985 so = tp->t_in6pcb->in6p_socket; 1986 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 1987 rt = in6_pcbrtentry(tp->t_in6pcb); 1988 #endif 1989 } 1990 #endif 1991 1992 /* 1993 * As per RFC1122, use the default MSS value, unless they 1994 * sent us an offer. Do not accept offers less than 256 bytes. 1995 */ 1996 mss = tcp_mssdflt; 1997 if (offer) 1998 mss = offer; 1999 mss = max(mss, 256); /* sanity */ 2000 tp->t_peermss = mss; 2001 mss -= tcp_optlen(tp); 2002 #ifdef INET 2003 if (tp->t_inpcb) 2004 mss -= ip_optlen(tp->t_inpcb); 2005 #endif 2006 #ifdef INET6 2007 if (tp->t_in6pcb) 2008 mss -= ip6_optlen(tp->t_in6pcb); 2009 #endif 2010 2011 /* 2012 * If there's a pipesize, change the socket buffer to that size. 2013 * Make the socket buffer an integral number of MSS units. If 2014 * the MSS is larger than the socket buffer, artificially decrease 2015 * the MSS. 2016 */ 2017 #ifdef RTV_SPIPE 2018 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0) 2019 bufsize = rt->rt_rmx.rmx_sendpipe; 2020 else 2021 #endif 2022 { 2023 KASSERT(so != NULL); 2024 bufsize = so->so_snd.sb_hiwat; 2025 } 2026 if (bufsize < mss) 2027 mss = bufsize; 2028 else { 2029 bufsize = roundup(bufsize, mss); 2030 if (bufsize > sb_max) 2031 bufsize = sb_max; 2032 (void) sbreserve(&so->so_snd, bufsize, so); 2033 } 2034 tp->t_segsz = mss; 2035 2036 #ifdef RTV_SSTHRESH 2037 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) { 2038 /* 2039 * There's some sort of gateway or interface buffer 2040 * limit on the path. Use this to set the slow 2041 * start threshold, but set the threshold to no less 2042 * than 2 * MSS. 2043 */ 2044 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); 2045 } 2046 #endif 2047 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH) 2048 #ifdef INET 2049 if (tp->t_inpcb) 2050 in_pcbrtentry_unref(rt, tp->t_inpcb); 2051 #endif 2052 #ifdef INET6 2053 if (tp->t_in6pcb) 2054 in6_pcbrtentry_unref(rt, tp->t_in6pcb); 2055 #endif 2056 #endif 2057 } 2058 2059 /* 2060 * Processing necessary when a TCP connection is established. 2061 */ 2062 void 2063 tcp_established(struct tcpcb *tp) 2064 { 2065 struct socket *so; 2066 #ifdef RTV_RPIPE 2067 struct rtentry *rt; 2068 #endif 2069 u_long bufsize; 2070 2071 #ifdef DIAGNOSTIC 2072 if (tp->t_inpcb && tp->t_in6pcb) 2073 panic("tcp_established: both t_inpcb and t_in6pcb are set"); 2074 #endif 2075 so = NULL; 2076 rt = NULL; 2077 #ifdef INET 2078 /* This is a while() to reduce the dreadful stairstepping below */ 2079 while (tp->t_inpcb) { 2080 so = tp->t_inpcb->inp_socket; 2081 #if defined(RTV_RPIPE) 2082 rt = in_pcbrtentry(tp->t_inpcb); 2083 #endif 2084 if (__predict_true(tcp_msl_enable)) { 2085 if (tp->t_inpcb->inp_laddr.s_addr == INADDR_LOOPBACK) { 2086 tp->t_msl = tcp_msl_loop ? tcp_msl_loop : (TCPTV_MSL >> 2); 2087 break; 2088 } 2089 2090 if (__predict_false(tcp_rttlocal)) { 2091 /* This may be adjusted by tcp_input */ 2092 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2093 break; 2094 } 2095 if (in_localaddr(tp->t_inpcb->inp_faddr)) { 2096 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2097 break; 2098 } 2099 } 2100 tp->t_msl = tcp_msl_remote ? tcp_msl_remote : TCPTV_MSL; 2101 break; 2102 } 2103 #endif 2104 #ifdef INET6 2105 /* The !tp->t_inpcb lets the compiler know it can't be v4 *and* v6 */ 2106 while (!tp->t_inpcb && tp->t_in6pcb) { 2107 so = tp->t_in6pcb->in6p_socket; 2108 #if defined(RTV_RPIPE) 2109 rt = in6_pcbrtentry(tp->t_in6pcb); 2110 #endif 2111 if (__predict_true(tcp_msl_enable)) { 2112 extern const struct in6_addr in6addr_loopback; 2113 2114 if (IN6_ARE_ADDR_EQUAL(&tp->t_in6pcb->in6p_laddr, 2115 &in6addr_loopback)) { 2116 tp->t_msl = tcp_msl_loop ? tcp_msl_loop : (TCPTV_MSL >> 2); 2117 break; 2118 } 2119 2120 if (__predict_false(tcp_rttlocal)) { 2121 /* This may be adjusted by tcp_input */ 2122 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2123 break; 2124 } 2125 if (in6_localaddr(&tp->t_in6pcb->in6p_faddr)) { 2126 tp->t_msl = tcp_msl_local ? tcp_msl_local : (TCPTV_MSL >> 1); 2127 break; 2128 } 2129 } 2130 tp->t_msl = tcp_msl_remote ? tcp_msl_remote : TCPTV_MSL; 2131 break; 2132 } 2133 #endif 2134 2135 tp->t_state = TCPS_ESTABLISHED; 2136 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle); 2137 2138 #ifdef RTV_RPIPE 2139 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0) 2140 bufsize = rt->rt_rmx.rmx_recvpipe; 2141 else 2142 #endif 2143 { 2144 KASSERT(so != NULL); 2145 bufsize = so->so_rcv.sb_hiwat; 2146 } 2147 if (bufsize > tp->t_ourmss) { 2148 bufsize = roundup(bufsize, tp->t_ourmss); 2149 if (bufsize > sb_max) 2150 bufsize = sb_max; 2151 (void) sbreserve(&so->so_rcv, bufsize, so); 2152 } 2153 #ifdef RTV_RPIPE 2154 #ifdef INET 2155 if (tp->t_inpcb) 2156 in_pcbrtentry_unref(rt, tp->t_inpcb); 2157 #endif 2158 #ifdef INET6 2159 if (tp->t_in6pcb) 2160 in6_pcbrtentry_unref(rt, tp->t_in6pcb); 2161 #endif 2162 #endif 2163 } 2164 2165 /* 2166 * Check if there's an initial rtt or rttvar. Convert from the 2167 * route-table units to scaled multiples of the slow timeout timer. 2168 * Called only during the 3-way handshake. 2169 */ 2170 void 2171 tcp_rmx_rtt(struct tcpcb *tp) 2172 { 2173 #ifdef RTV_RTT 2174 struct rtentry *rt = NULL; 2175 int rtt; 2176 2177 #ifdef DIAGNOSTIC 2178 if (tp->t_inpcb && tp->t_in6pcb) 2179 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set"); 2180 #endif 2181 #ifdef INET 2182 if (tp->t_inpcb) 2183 rt = in_pcbrtentry(tp->t_inpcb); 2184 #endif 2185 #ifdef INET6 2186 if (tp->t_in6pcb) 2187 rt = in6_pcbrtentry(tp->t_in6pcb); 2188 #endif 2189 if (rt == NULL) 2190 return; 2191 2192 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { 2193 /* 2194 * XXX The lock bit for MTU indicates that the value 2195 * is also a minimum value; this is subject to time. 2196 */ 2197 if (rt->rt_rmx.rmx_locks & RTV_RTT) 2198 TCPT_RANGESET(tp->t_rttmin, 2199 rtt / (RTM_RTTUNIT / PR_SLOWHZ), 2200 TCPTV_MIN, TCPTV_REXMTMAX); 2201 tp->t_srtt = rtt / 2202 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2)); 2203 if (rt->rt_rmx.rmx_rttvar) { 2204 tp->t_rttvar = rt->rt_rmx.rmx_rttvar / 2205 ((RTM_RTTUNIT / PR_SLOWHZ) >> 2206 (TCP_RTTVAR_SHIFT + 2)); 2207 } else { 2208 /* Default variation is +- 1 rtt */ 2209 tp->t_rttvar = 2210 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT); 2211 } 2212 TCPT_RANGESET(tp->t_rxtcur, 2213 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2), 2214 tp->t_rttmin, TCPTV_REXMTMAX); 2215 } 2216 #ifdef INET 2217 if (tp->t_inpcb) 2218 in_pcbrtentry_unref(rt, tp->t_inpcb); 2219 #endif 2220 #ifdef INET6 2221 if (tp->t_in6pcb) 2222 in6_pcbrtentry_unref(rt, tp->t_in6pcb); 2223 #endif 2224 #endif 2225 } 2226 2227 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */ 2228 2229 /* 2230 * Get a new sequence value given a tcp control block 2231 */ 2232 tcp_seq 2233 tcp_new_iss(struct tcpcb *tp, tcp_seq addin) 2234 { 2235 2236 #ifdef INET 2237 if (tp->t_inpcb != NULL) { 2238 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr, 2239 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport, 2240 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr), 2241 addin)); 2242 } 2243 #endif 2244 #ifdef INET6 2245 if (tp->t_in6pcb != NULL) { 2246 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr, 2247 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport, 2248 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr), 2249 addin)); 2250 } 2251 #endif 2252 /* Not possible. */ 2253 panic("tcp_new_iss"); 2254 } 2255 2256 static u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */ 2257 2258 /* 2259 * Initialize RFC 1948 ISS Secret 2260 */ 2261 static int 2262 tcp_iss_secret_init(void) 2263 { 2264 cprng_strong(kern_cprng, 2265 tcp_iss_secret, sizeof(tcp_iss_secret), 0); 2266 2267 return 0; 2268 } 2269 2270 /* 2271 * This routine actually generates a new TCP initial sequence number. 2272 */ 2273 tcp_seq 2274 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport, 2275 size_t addrsz, tcp_seq addin) 2276 { 2277 tcp_seq tcp_iss; 2278 2279 if (tcp_do_rfc1948) { 2280 MD5_CTX ctx; 2281 u_int8_t hash[16]; /* XXX MD5 knowledge */ 2282 static ONCE_DECL(tcp_iss_secret_control); 2283 2284 /* 2285 * If we haven't been here before, initialize our cryptographic 2286 * hash secret. 2287 */ 2288 RUN_ONCE(&tcp_iss_secret_control, tcp_iss_secret_init); 2289 2290 /* 2291 * Compute the base value of the ISS. It is a hash 2292 * of (saddr, sport, daddr, dport, secret). 2293 */ 2294 MD5Init(&ctx); 2295 2296 MD5Update(&ctx, (u_char *) laddr, addrsz); 2297 MD5Update(&ctx, (u_char *) &lport, sizeof(lport)); 2298 2299 MD5Update(&ctx, (u_char *) faddr, addrsz); 2300 MD5Update(&ctx, (u_char *) &fport, sizeof(fport)); 2301 2302 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret)); 2303 2304 MD5Final(hash, &ctx); 2305 2306 memcpy(&tcp_iss, hash, sizeof(tcp_iss)); 2307 2308 /* 2309 * Now increment our "timer", and add it in to 2310 * the computed value. 2311 * 2312 * XXX Use `addin'? 2313 * XXX TCP_ISSINCR too large to use? 2314 */ 2315 tcp_iss_seq += TCP_ISSINCR; 2316 #ifdef TCPISS_DEBUG 2317 printf("ISS hash 0x%08x, ", tcp_iss); 2318 #endif 2319 tcp_iss += tcp_iss_seq + addin; 2320 #ifdef TCPISS_DEBUG 2321 printf("new ISS 0x%08x\n", tcp_iss); 2322 #endif 2323 } else { 2324 /* 2325 * Randomize. 2326 */ 2327 tcp_iss = cprng_fast32(); 2328 2329 /* 2330 * If we were asked to add some amount to a known value, 2331 * we will take a random value obtained above, mask off 2332 * the upper bits, and add in the known value. We also 2333 * add in a constant to ensure that we are at least a 2334 * certain distance from the original value. 2335 * 2336 * This is used when an old connection is in timed wait 2337 * and we have a new one coming in, for instance. 2338 */ 2339 if (addin != 0) { 2340 #ifdef TCPISS_DEBUG 2341 printf("Random %08x, ", tcp_iss); 2342 #endif 2343 tcp_iss &= TCP_ISS_RANDOM_MASK; 2344 tcp_iss += addin + TCP_ISSINCR; 2345 #ifdef TCPISS_DEBUG 2346 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss); 2347 #endif 2348 } else { 2349 tcp_iss &= TCP_ISS_RANDOM_MASK; 2350 tcp_iss += tcp_iss_seq; 2351 tcp_iss_seq += TCP_ISSINCR; 2352 #ifdef TCPISS_DEBUG 2353 printf("ISS %08x\n", tcp_iss); 2354 #endif 2355 } 2356 } 2357 2358 if (tcp_compat_42) { 2359 /* 2360 * Limit it to the positive range for really old TCP 2361 * implementations. 2362 * Just AND off the top bit instead of checking if 2363 * is set first - saves a branch 50% of the time. 2364 */ 2365 tcp_iss &= 0x7fffffff; /* XXX */ 2366 } 2367 2368 return (tcp_iss); 2369 } 2370 2371 #if defined(IPSEC) 2372 /* compute ESP/AH header size for TCP, including outer IP header. */ 2373 size_t 2374 ipsec4_hdrsiz_tcp(struct tcpcb *tp) 2375 { 2376 struct inpcb *inp; 2377 size_t hdrsiz; 2378 2379 /* XXX mapped addr case (tp->t_in6pcb) */ 2380 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 2381 return 0; 2382 switch (tp->t_family) { 2383 case AF_INET: 2384 /* XXX: should use currect direction. */ 2385 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp); 2386 break; 2387 default: 2388 hdrsiz = 0; 2389 break; 2390 } 2391 2392 return hdrsiz; 2393 } 2394 2395 #ifdef INET6 2396 size_t 2397 ipsec6_hdrsiz_tcp(struct tcpcb *tp) 2398 { 2399 struct in6pcb *in6p; 2400 size_t hdrsiz; 2401 2402 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb)) 2403 return 0; 2404 switch (tp->t_family) { 2405 case AF_INET6: 2406 /* XXX: should use currect direction. */ 2407 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p); 2408 break; 2409 case AF_INET: 2410 /* mapped address case - tricky */ 2411 default: 2412 hdrsiz = 0; 2413 break; 2414 } 2415 2416 return hdrsiz; 2417 } 2418 #endif 2419 #endif /*IPSEC*/ 2420 2421 /* 2422 * Determine the length of the TCP options for this connection. 2423 * 2424 * XXX: What do we do for SACK, when we add that? Just reserve 2425 * all of the space? Otherwise we can't exactly be incrementing 2426 * cwnd by an amount that varies depending on the amount we last 2427 * had to SACK! 2428 */ 2429 2430 u_int 2431 tcp_optlen(struct tcpcb *tp) 2432 { 2433 u_int optlen; 2434 2435 optlen = 0; 2436 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) == 2437 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 2438 optlen += TCPOLEN_TSTAMP_APPA; 2439 2440 #ifdef TCP_SIGNATURE 2441 if (tp->t_flags & TF_SIGNATURE) 2442 optlen += TCPOLEN_SIGNATURE + 2; 2443 #endif /* TCP_SIGNATURE */ 2444 2445 return optlen; 2446 } 2447 2448 u_int 2449 tcp_hdrsz(struct tcpcb *tp) 2450 { 2451 u_int hlen; 2452 2453 switch (tp->t_family) { 2454 #ifdef INET6 2455 case AF_INET6: 2456 hlen = sizeof(struct ip6_hdr); 2457 break; 2458 #endif 2459 case AF_INET: 2460 hlen = sizeof(struct ip); 2461 break; 2462 default: 2463 hlen = 0; 2464 break; 2465 } 2466 hlen += sizeof(struct tcphdr); 2467 2468 if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && 2469 (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP) 2470 hlen += TCPOLEN_TSTAMP_APPA; 2471 #ifdef TCP_SIGNATURE 2472 if (tp->t_flags & TF_SIGNATURE) 2473 hlen += TCPOLEN_SIGLEN; 2474 #endif 2475 return hlen; 2476 } 2477 2478 void 2479 tcp_statinc(u_int stat) 2480 { 2481 2482 KASSERT(stat < TCP_NSTATS); 2483 TCP_STATINC(stat); 2484 } 2485 2486 void 2487 tcp_statadd(u_int stat, uint64_t val) 2488 { 2489 2490 KASSERT(stat < TCP_NSTATS); 2491 TCP_STATADD(stat, val); 2492 } 2493
Indexes created Sun Sep 21 20:09:37 GMT 2025