1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_compat.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 #include "opt_ipsec.h" 39 #include "opt_tcpdebug.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/callout.h> 44 #include <sys/eventhandler.h> 45 #include <sys/hhook.h> 46 #include <sys/kernel.h> 47 #include <sys/khelp.h> 48 #include <sys/sysctl.h> 49 #include <sys/jail.h> 50 #include <sys/malloc.h> 51 #include <sys/refcount.h> 52 #include <sys/mbuf.h> 53 #ifdef INET6 54 #include <sys/domain.h> 55 #endif 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/sdt.h> 59 #include <sys/socket.h> 60 #include <sys/socketvar.h> 61 #include <sys/protosw.h> 62 #include <sys/random.h> 63 64 #include <vm/uma.h> 65 66 #include <net/route.h> 67 #include <net/if.h> 68 #include <net/if_var.h> 69 #include <net/vnet.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_fib.h> 73 #include <netinet/in_kdtrace.h> 74 #include <netinet/in_pcb.h> 75 #include <netinet/in_systm.h> 76 #include <netinet/in_var.h> 77 #include <netinet/ip.h> 78 #include <netinet/ip_icmp.h> 79 #include <netinet/ip_var.h> 80 #ifdef INET6 81 #include <netinet/ip6.h> 82 #include <netinet6/in6_fib.h> 83 #include <netinet6/in6_pcb.h> 84 #include <netinet6/ip6_var.h> 85 #include <netinet6/scope6_var.h> 86 #include <netinet6/nd6.h> 87 #endif 88 89 #ifdef TCP_RFC7413 90 #include <netinet/tcp_fastopen.h> 91 #endif 92 #include <netinet/tcp.h> 93 #include <netinet/tcp_fsm.h> 94 #include <netinet/tcp_seq.h> 95 #include <netinet/tcp_timer.h> 96 #include <netinet/tcp_var.h> 97 #include <netinet/tcp_syncache.h> 98 #include <netinet/cc/cc.h> 99 #ifdef INET6 100 #include <netinet6/tcp6_var.h> 101 #endif 102 #include <netinet/tcpip.h> 103 #ifdef TCPPCAP 104 #include <netinet/tcp_pcap.h> 105 #endif 106 #ifdef TCPDEBUG 107 #include <netinet/tcp_debug.h> 108 #endif 109 #ifdef INET6 110 #include <netinet6/ip6protosw.h> 111 #endif 112 #ifdef TCP_OFFLOAD 113 #include <netinet/tcp_offload.h> 114 #endif 115 116 #ifdef IPSEC 117 #include <netipsec/ipsec.h> 118 #include <netipsec/xform.h> 119 #ifdef INET6 120 #include <netipsec/ipsec6.h> 121 #endif 122 #include <netipsec/key.h> 123 #include <sys/syslog.h> 124 #endif /*IPSEC*/ 125 126 #include <machine/in_cksum.h> 127 #include <sys/md5.h> 128 129 #include <security/mac/mac_framework.h> 130 131 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 132 #ifdef INET6 133 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 134 #endif 135 136 struct rwlock tcp_function_lock; 137 138 static int 139 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 140 { 141 int error, new; 142 143 new = V_tcp_mssdflt; 144 error = sysctl_handle_int(oidp, &new, 0, req); 145 if (error == 0 && req->newptr) { 146 if (new < TCP_MINMSS) 147 error = EINVAL; 148 else 149 V_tcp_mssdflt = new; 150 } 151 return (error); 152 } 153 154 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 155 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 156 &sysctl_net_inet_tcp_mss_check, "I", 157 "Default TCP Maximum Segment Size"); 158 159 #ifdef INET6 160 static int 161 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 162 { 163 int error, new; 164 165 new = V_tcp_v6mssdflt; 166 error = sysctl_handle_int(oidp, &new, 0, req); 167 if (error == 0 && req->newptr) { 168 if (new < TCP_MINMSS) 169 error = EINVAL; 170 else 171 V_tcp_v6mssdflt = new; 172 } 173 return (error); 174 } 175 176 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 177 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 178 &sysctl_net_inet_tcp_mss_v6_check, "I", 179 "Default TCP Maximum Segment Size for IPv6"); 180 #endif /* INET6 */ 181 182 /* 183 * Minimum MSS we accept and use. This prevents DoS attacks where 184 * we are forced to a ridiculous low MSS like 20 and send hundreds 185 * of packets instead of one. The effect scales with the available 186 * bandwidth and quickly saturates the CPU and network interface 187 * with packet generation and sending. Set to zero to disable MINMSS 188 * checking. This setting prevents us from sending too small packets. 189 */ 190 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 191 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 192 &VNET_NAME(tcp_minmss), 0, 193 "Minimum TCP Maximum Segment Size"); 194 195 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 196 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 197 &VNET_NAME(tcp_do_rfc1323), 0, 198 "Enable rfc1323 (high performance TCP) extensions"); 199 200 static int tcp_log_debug = 0; 201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 202 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 203 204 static int tcp_tcbhashsize; 205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 206 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 207 208 static int do_tcpdrain = 1; 209 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 210 "Enable tcp_drain routine for extra help when low on mbufs"); 211 212 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 213 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 214 215 static VNET_DEFINE(int, icmp_may_rst) = 1; 216 #define V_icmp_may_rst VNET(icmp_may_rst) 217 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 218 &VNET_NAME(icmp_may_rst), 0, 219 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 220 221 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 222 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 223 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 224 &VNET_NAME(tcp_isn_reseed_interval), 0, 225 "Seconds between reseeding of ISN secret"); 226 227 static int tcp_soreceive_stream; 228 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 229 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 230 231 #ifdef TCP_SIGNATURE 232 static int tcp_sig_checksigs = 1; 233 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 234 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 235 #endif 236 237 VNET_DEFINE(uma_zone_t, sack_hole_zone); 238 #define V_sack_hole_zone VNET(sack_hole_zone) 239 240 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 241 242 static struct inpcb *tcp_notify(struct inpcb *, int); 243 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 244 static void tcp_mtudisc(struct inpcb *, int); 245 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 246 void *ip4hdr, const void *ip6hdr); 247 static void tcp_timer_discard(struct tcpcb *, uint32_t); 248 249 250 static struct tcp_function_block tcp_def_funcblk = { 251 "default", 252 tcp_output, 253 tcp_do_segment, 254 tcp_default_ctloutput, 255 NULL, 256 NULL, 257 NULL, 258 NULL, 259 NULL, 260 NULL, 261 NULL, 262 0, 263 0 264 }; 265 266 int t_functions_inited = 0; 267 struct tcp_funchead t_functions; 268 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 269 270 static void 271 init_tcp_functions(void) 272 { 273 if (t_functions_inited == 0) { 274 TAILQ_INIT(&t_functions); 275 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 276 t_functions_inited = 1; 277 } 278 } 279 280 static struct tcp_function_block * 281 find_tcp_functions_locked(struct tcp_function_set *fs) 282 { 283 struct tcp_function *f; 284 struct tcp_function_block *blk=NULL; 285 286 TAILQ_FOREACH(f, &t_functions, tf_next) { 287 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 288 blk = f->tf_fb; 289 break; 290 } 291 } 292 return(blk); 293 } 294 295 static struct tcp_function_block * 296 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 297 { 298 struct tcp_function_block *rblk=NULL; 299 struct tcp_function *f; 300 301 TAILQ_FOREACH(f, &t_functions, tf_next) { 302 if (f->tf_fb == blk) { 303 rblk = blk; 304 if (s) { 305 *s = f; 306 } 307 break; 308 } 309 } 310 return (rblk); 311 } 312 313 struct tcp_function_block * 314 find_and_ref_tcp_functions(struct tcp_function_set *fs) 315 { 316 struct tcp_function_block *blk; 317 318 rw_rlock(&tcp_function_lock); 319 blk = find_tcp_functions_locked(fs); 320 if (blk) 321 refcount_acquire(&blk->tfb_refcnt); 322 rw_runlock(&tcp_function_lock); 323 return(blk); 324 } 325 326 struct tcp_function_block * 327 find_and_ref_tcp_fb(struct tcp_function_block *blk) 328 { 329 struct tcp_function_block *rblk; 330 331 rw_rlock(&tcp_function_lock); 332 rblk = find_tcp_fb_locked(blk, NULL); 333 if (rblk) 334 refcount_acquire(&rblk->tfb_refcnt); 335 rw_runlock(&tcp_function_lock); 336 return(rblk); 337 } 338 339 340 static int 341 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 342 { 343 int error=ENOENT; 344 struct tcp_function_set fs; 345 struct tcp_function_block *blk; 346 347 memset(&fs, 0, sizeof(fs)); 348 rw_rlock(&tcp_function_lock); 349 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 350 if (blk) { 351 /* Found him */ 352 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 353 fs.pcbcnt = blk->tfb_refcnt; 354 } 355 rw_runlock(&tcp_function_lock); 356 error = sysctl_handle_string(oidp, fs.function_set_name, 357 sizeof(fs.function_set_name), req); 358 359 /* Check for error or no change */ 360 if (error != 0 || req->newptr == NULL) 361 return(error); 362 363 rw_wlock(&tcp_function_lock); 364 blk = find_tcp_functions_locked(&fs); 365 if ((blk == NULL) || 366 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 367 error = ENOENT; 368 goto done; 369 } 370 tcp_func_set_ptr = blk; 371 done: 372 rw_wunlock(&tcp_function_lock); 373 return (error); 374 } 375 376 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 377 CTLTYPE_STRING | CTLFLAG_RW, 378 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 379 "Set/get the default TCP functions"); 380 381 static int 382 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 383 { 384 int error, cnt, linesz; 385 struct tcp_function *f; 386 char *buffer, *cp; 387 size_t bufsz, outsz; 388 389 cnt = 0; 390 rw_rlock(&tcp_function_lock); 391 TAILQ_FOREACH(f, &t_functions, tf_next) { 392 cnt++; 393 } 394 rw_runlock(&tcp_function_lock); 395 396 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 397 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 398 399 error = 0; 400 cp = buffer; 401 402 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 403 cp += linesz; 404 bufsz -= linesz; 405 outsz = linesz; 406 407 rw_rlock(&tcp_function_lock); 408 TAILQ_FOREACH(f, &t_functions, tf_next) { 409 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 410 f->tf_fb->tfb_tcp_block_name, 411 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 412 f->tf_fb->tfb_refcnt); 413 if (linesz >= bufsz) { 414 error = EOVERFLOW; 415 break; 416 } 417 cp += linesz; 418 bufsz -= linesz; 419 outsz += linesz; 420 } 421 rw_runlock(&tcp_function_lock); 422 if (error == 0) 423 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 424 free(buffer, M_TEMP); 425 return (error); 426 } 427 428 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 429 CTLTYPE_STRING|CTLFLAG_RD, 430 NULL, 0, sysctl_net_inet_list_available, "A", 431 "list available TCP Function sets"); 432 433 /* 434 * Target size of TCP PCB hash tables. Must be a power of two. 435 * 436 * Note that this can be overridden by the kernel environment 437 * variable net.inet.tcp.tcbhashsize 438 */ 439 #ifndef TCBHASHSIZE 440 #define TCBHASHSIZE 0 441 #endif 442 443 /* 444 * XXX 445 * Callouts should be moved into struct tcp directly. They are currently 446 * separate because the tcpcb structure is exported to userland for sysctl 447 * parsing purposes, which do not know about callouts. 448 */ 449 struct tcpcb_mem { 450 struct tcpcb tcb; 451 struct tcp_timer tt; 452 struct cc_var ccv; 453 struct osd osd; 454 }; 455 456 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 457 #define V_tcpcb_zone VNET(tcpcb_zone) 458 459 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 460 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 461 462 static struct mtx isn_mtx; 463 464 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 465 #define ISN_LOCK() mtx_lock(&isn_mtx) 466 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 467 468 /* 469 * TCP initialization. 470 */ 471 static void 472 tcp_zone_change(void *tag) 473 { 474 475 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 476 uma_zone_set_max(V_tcpcb_zone, maxsockets); 477 tcp_tw_zone_change(); 478 } 479 480 static int 481 tcp_inpcb_init(void *mem, int size, int flags) 482 { 483 struct inpcb *inp = mem; 484 485 INP_LOCK_INIT(inp, "inp", "tcpinp"); 486 return (0); 487 } 488 489 /* 490 * Take a value and get the next power of 2 that doesn't overflow. 491 * Used to size the tcp_inpcb hash buckets. 492 */ 493 static int 494 maketcp_hashsize(int size) 495 { 496 int hashsize; 497 498 /* 499 * auto tune. 500 * get the next power of 2 higher than maxsockets. 501 */ 502 hashsize = 1 << fls(size); 503 /* catch overflow, and just go one power of 2 smaller */ 504 if (hashsize < size) { 505 hashsize = 1 << (fls(size) - 1); 506 } 507 return (hashsize); 508 } 509 510 int 511 register_tcp_functions(struct tcp_function_block *blk, int wait) 512 { 513 struct tcp_function_block *lblk; 514 struct tcp_function *n; 515 struct tcp_function_set fs; 516 517 if (t_functions_inited == 0) { 518 init_tcp_functions(); 519 } 520 if ((blk->tfb_tcp_output == NULL) || 521 (blk->tfb_tcp_do_segment == NULL) || 522 (blk->tfb_tcp_ctloutput == NULL) || 523 (strlen(blk->tfb_tcp_block_name) == 0)) { 524 /* 525 * These functions are required and you 526 * need a name. 527 */ 528 return (EINVAL); 529 } 530 if (blk->tfb_tcp_timer_stop_all || 531 blk->tfb_tcp_timers_left || 532 blk->tfb_tcp_timer_activate || 533 blk->tfb_tcp_timer_active || 534 blk->tfb_tcp_timer_stop) { 535 /* 536 * If you define one timer function you 537 * must have them all. 538 */ 539 if ((blk->tfb_tcp_timer_stop_all == NULL) || 540 (blk->tfb_tcp_timers_left == NULL) || 541 (blk->tfb_tcp_timer_activate == NULL) || 542 (blk->tfb_tcp_timer_active == NULL) || 543 (blk->tfb_tcp_timer_stop == NULL)) { 544 return (EINVAL); 545 } 546 } 547 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 548 if (n == NULL) { 549 return (ENOMEM); 550 } 551 n->tf_fb = blk; 552 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 553 rw_wlock(&tcp_function_lock); 554 lblk = find_tcp_functions_locked(&fs); 555 if (lblk) { 556 /* Duplicate name space not allowed */ 557 rw_wunlock(&tcp_function_lock); 558 free(n, M_TCPFUNCTIONS); 559 return (EALREADY); 560 } 561 refcount_init(&blk->tfb_refcnt, 0); 562 blk->tfb_flags = 0; 563 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 564 rw_wunlock(&tcp_function_lock); 565 return(0); 566 } 567 568 int 569 deregister_tcp_functions(struct tcp_function_block *blk) 570 { 571 struct tcp_function_block *lblk; 572 struct tcp_function *f; 573 int error=ENOENT; 574 575 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 576 /* You can't un-register the default */ 577 return (EPERM); 578 } 579 rw_wlock(&tcp_function_lock); 580 if (blk == tcp_func_set_ptr) { 581 /* You can't free the current default */ 582 rw_wunlock(&tcp_function_lock); 583 return (EBUSY); 584 } 585 if (blk->tfb_refcnt) { 586 /* Still tcb attached, mark it. */ 587 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 588 rw_wunlock(&tcp_function_lock); 589 return (EBUSY); 590 } 591 lblk = find_tcp_fb_locked(blk, &f); 592 if (lblk) { 593 /* Found */ 594 TAILQ_REMOVE(&t_functions, f, tf_next); 595 f->tf_fb = NULL; 596 free(f, M_TCPFUNCTIONS); 597 error = 0; 598 } 599 rw_wunlock(&tcp_function_lock); 600 return (error); 601 } 602 603 void 604 tcp_init(void) 605 { 606 const char *tcbhash_tuneable; 607 int hashsize; 608 609 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 610 611 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 612 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 613 printf("%s: WARNING: unable to register helper hook\n", __func__); 614 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 615 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 616 printf("%s: WARNING: unable to register helper hook\n", __func__); 617 hashsize = TCBHASHSIZE; 618 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 619 if (hashsize == 0) { 620 /* 621 * Auto tune the hash size based on maxsockets. 622 * A perfect hash would have a 1:1 mapping 623 * (hashsize = maxsockets) however it's been 624 * suggested that O(2) average is better. 625 */ 626 hashsize = maketcp_hashsize(maxsockets / 4); 627 /* 628 * Our historical default is 512, 629 * do not autotune lower than this. 630 */ 631 if (hashsize < 512) 632 hashsize = 512; 633 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 634 printf("%s: %s auto tuned to %d\n", __func__, 635 tcbhash_tuneable, hashsize); 636 } 637 /* 638 * We require a hashsize to be a power of two. 639 * Previously if it was not a power of two we would just reset it 640 * back to 512, which could be a nasty surprise if you did not notice 641 * the error message. 642 * Instead what we do is clip it to the closest power of two lower 643 * than the specified hash value. 644 */ 645 if (!powerof2(hashsize)) { 646 int oldhashsize = hashsize; 647 648 hashsize = maketcp_hashsize(hashsize); 649 /* prevent absurdly low value */ 650 if (hashsize < 16) 651 hashsize = 16; 652 printf("%s: WARNING: TCB hash size not a power of 2, " 653 "clipped from %d to %d.\n", __func__, oldhashsize, 654 hashsize); 655 } 656 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 657 "tcp_inpcb", tcp_inpcb_init, NULL, 0, IPI_HASHFIELDS_4TUPLE); 658 659 /* 660 * These have to be type stable for the benefit of the timers. 661 */ 662 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 663 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 664 uma_zone_set_max(V_tcpcb_zone, maxsockets); 665 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 666 667 tcp_tw_init(); 668 syncache_init(); 669 tcp_hc_init(); 670 671 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 672 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 673 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 674 675 /* Skip initialization of globals for non-default instances. */ 676 if (!IS_DEFAULT_VNET(curvnet)) 677 return; 678 679 tcp_reass_global_init(); 680 681 /* XXX virtualize those bellow? */ 682 tcp_delacktime = TCPTV_DELACK; 683 tcp_keepinit = TCPTV_KEEP_INIT; 684 tcp_keepidle = TCPTV_KEEP_IDLE; 685 tcp_keepintvl = TCPTV_KEEPINTVL; 686 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 687 tcp_msl = TCPTV_MSL; 688 tcp_rexmit_min = TCPTV_MIN; 689 if (tcp_rexmit_min < 1) 690 tcp_rexmit_min = 1; 691 tcp_persmin = TCPTV_PERSMIN; 692 tcp_persmax = TCPTV_PERSMAX; 693 tcp_rexmit_slop = TCPTV_CPU_VAR; 694 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 695 tcp_tcbhashsize = hashsize; 696 /* Setup the tcp function block list */ 697 init_tcp_functions(); 698 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 699 700 if (tcp_soreceive_stream) { 701 #ifdef INET 702 tcp_usrreqs.pru_soreceive = soreceive_stream; 703 #endif 704 #ifdef INET6 705 tcp6_usrreqs.pru_soreceive = soreceive_stream; 706 #endif /* INET6 */ 707 } 708 709 #ifdef INET6 710 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 711 #else /* INET6 */ 712 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 713 #endif /* INET6 */ 714 if (max_protohdr < TCP_MINPROTOHDR) 715 max_protohdr = TCP_MINPROTOHDR; 716 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 717 panic("tcp_init"); 718 #undef TCP_MINPROTOHDR 719 720 ISN_LOCK_INIT(); 721 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 722 SHUTDOWN_PRI_DEFAULT); 723 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 724 EVENTHANDLER_PRI_ANY); 725 #ifdef TCPPCAP 726 tcp_pcap_init(); 727 #endif 728 729 #ifdef TCP_RFC7413 730 tcp_fastopen_init(); 731 #endif 732 } 733 734 #ifdef VIMAGE 735 void 736 tcp_destroy(void) 737 { 738 int error; 739 740 /* 741 * All our processes are gone, all our sockets should be cleaned 742 * up, which means, we should be past the tcp_discardcb() calls. 743 * Sleep to let all tcpcb timers really disappear and then cleanup. 744 * Timewait will cleanup its queue and will be ready to go. 745 * XXX-BZ In theory a few ticks should be good enough to make sure 746 * the timers are all really gone. We should see if we could use a 747 * better metric here and, e.g., check a tcbcb count as an optimization? 748 */ 749 DELAY(1000000 / hz); 750 tcp_hc_destroy(); 751 syncache_destroy(); 752 tcp_tw_destroy(); 753 in_pcbinfo_destroy(&V_tcbinfo); 754 /* tcp_discardcb() clears the sack_holes up. */ 755 uma_zdestroy(V_sack_hole_zone); 756 uma_zdestroy(V_tcpcb_zone); 757 758 #ifdef TCP_RFC7413 759 /* 760 * Cannot free the zone until all tcpcbs are released as we attach 761 * the allocations to them. 762 */ 763 tcp_fastopen_destroy(); 764 #endif 765 766 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 767 if (error != 0) { 768 printf("%s: WARNING: unable to deregister helper hook " 769 "type=%d, id=%d: error %d returned\n", __func__, 770 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 771 } 772 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 773 if (error != 0) { 774 printf("%s: WARNING: unable to deregister helper hook " 775 "type=%d, id=%d: error %d returned\n", __func__, 776 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 777 } 778 } 779 #endif 780 781 void 782 tcp_fini(void *xtp) 783 { 784 785 } 786 787 /* 788 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 789 * tcp_template used to store this data in mbufs, but we now recopy it out 790 * of the tcpcb each time to conserve mbufs. 791 */ 792 void 793 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 794 { 795 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 796 797 INP_WLOCK_ASSERT(inp); 798 799 #ifdef INET6 800 if ((inp->inp_vflag & INP_IPV6) != 0) { 801 struct ip6_hdr *ip6; 802 803 ip6 = (struct ip6_hdr *)ip_ptr; 804 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 805 (inp->inp_flow & IPV6_FLOWINFO_MASK); 806 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 807 (IPV6_VERSION & IPV6_VERSION_MASK); 808 ip6->ip6_nxt = IPPROTO_TCP; 809 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 810 ip6->ip6_src = inp->in6p_laddr; 811 ip6->ip6_dst = inp->in6p_faddr; 812 } 813 #endif /* INET6 */ 814 #if defined(INET6) && defined(INET) 815 else 816 #endif 817 #ifdef INET 818 { 819 struct ip *ip; 820 821 ip = (struct ip *)ip_ptr; 822 ip->ip_v = IPVERSION; 823 ip->ip_hl = 5; 824 ip->ip_tos = inp->inp_ip_tos; 825 ip->ip_len = 0; 826 ip->ip_id = 0; 827 ip->ip_off = 0; 828 ip->ip_ttl = inp->inp_ip_ttl; 829 ip->ip_sum = 0; 830 ip->ip_p = IPPROTO_TCP; 831 ip->ip_src = inp->inp_laddr; 832 ip->ip_dst = inp->inp_faddr; 833 } 834 #endif /* INET */ 835 th->th_sport = inp->inp_lport; 836 th->th_dport = inp->inp_fport; 837 th->th_seq = 0; 838 th->th_ack = 0; 839 th->th_x2 = 0; 840 th->th_off = 5; 841 th->th_flags = 0; 842 th->th_win = 0; 843 th->th_urp = 0; 844 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 845 } 846 847 /* 848 * Create template to be used to send tcp packets on a connection. 849 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 850 * use for this function is in keepalives, which use tcp_respond. 851 */ 852 struct tcptemp * 853 tcpip_maketemplate(struct inpcb *inp) 854 { 855 struct tcptemp *t; 856 857 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 858 if (t == NULL) 859 return (NULL); 860 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 861 return (t); 862 } 863 864 /* 865 * Send a single message to the TCP at address specified by 866 * the given TCP/IP header. If m == NULL, then we make a copy 867 * of the tcpiphdr at th and send directly to the addressed host. 868 * This is used to force keep alive messages out using the TCP 869 * template for a connection. If flags are given then we send 870 * a message back to the TCP which originated the segment th, 871 * and discard the mbuf containing it and any other attached mbufs. 872 * 873 * In any case the ack and sequence number of the transmitted 874 * segment are as specified by the parameters. 875 * 876 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 877 */ 878 void 879 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 880 tcp_seq ack, tcp_seq seq, int flags) 881 { 882 struct tcpopt to; 883 struct inpcb *inp; 884 struct ip *ip; 885 struct mbuf *optm; 886 struct tcphdr *nth; 887 u_char *optp; 888 #ifdef INET6 889 struct ip6_hdr *ip6; 890 int isipv6; 891 #endif /* INET6 */ 892 int optlen, tlen, win; 893 bool incl_opts; 894 895 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 896 897 #ifdef INET6 898 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 899 ip6 = ipgen; 900 #endif /* INET6 */ 901 ip = ipgen; 902 903 if (tp != NULL) { 904 inp = tp->t_inpcb; 905 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 906 INP_WLOCK_ASSERT(inp); 907 } else 908 inp = NULL; 909 910 incl_opts = false; 911 win = 0; 912 if (tp != NULL) { 913 if (!(flags & TH_RST)) { 914 win = sbspace(&inp->inp_socket->so_rcv); 915 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 916 win = (long)TCP_MAXWIN << tp->rcv_scale; 917 } 918 if ((tp->t_flags & TF_NOOPT) == 0) 919 incl_opts = true; 920 } 921 if (m == NULL) { 922 m = m_gethdr(M_NOWAIT, MT_DATA); 923 if (m == NULL) 924 return; 925 m->m_data += max_linkhdr; 926 #ifdef INET6 927 if (isipv6) { 928 bcopy((caddr_t)ip6, mtod(m, caddr_t), 929 sizeof(struct ip6_hdr)); 930 ip6 = mtod(m, struct ip6_hdr *); 931 nth = (struct tcphdr *)(ip6 + 1); 932 } else 933 #endif /* INET6 */ 934 { 935 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 936 ip = mtod(m, struct ip *); 937 nth = (struct tcphdr *)(ip + 1); 938 } 939 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 940 flags = TH_ACK; 941 } else { 942 /* 943 * reuse the mbuf. 944 * XXX MRT We inherrit the FIB, which is lucky. 945 */ 946 m_freem(m->m_next); 947 m->m_next = NULL; 948 m->m_data = (caddr_t)ipgen; 949 /* m_len is set later */ 950 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 951 #ifdef INET6 952 if (isipv6) { 953 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 954 nth = (struct tcphdr *)(ip6 + 1); 955 } else 956 #endif /* INET6 */ 957 { 958 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 959 nth = (struct tcphdr *)(ip + 1); 960 } 961 if (th != nth) { 962 /* 963 * this is usually a case when an extension header 964 * exists between the IPv6 header and the 965 * TCP header. 966 */ 967 nth->th_sport = th->th_sport; 968 nth->th_dport = th->th_dport; 969 } 970 xchg(nth->th_dport, nth->th_sport, uint16_t); 971 #undef xchg 972 } 973 tlen = 0; 974 #ifdef INET6 975 if (isipv6) 976 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 977 #endif 978 #if defined(INET) && defined(INET6) 979 else 980 #endif 981 #ifdef INET 982 tlen = sizeof (struct tcpiphdr); 983 #endif 984 #ifdef INVARIANTS 985 m->m_len = 0; 986 KASSERT(M_TRAILINGSPACE(m) >= tlen, 987 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 988 m, tlen, (long)M_TRAILINGSPACE(m))); 989 #endif 990 m->m_len = tlen; 991 to.to_flags = 0; 992 if (incl_opts) { 993 /* Make sure we have room. */ 994 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 995 m->m_next = m_get(M_NOWAIT, MT_DATA); 996 if (m->m_next) { 997 optp = mtod(m->m_next, u_char *); 998 optm = m->m_next; 999 } else 1000 incl_opts = false; 1001 } else { 1002 optp = (u_char *) (nth + 1); 1003 optm = m; 1004 } 1005 } 1006 if (incl_opts) { 1007 /* Timestamps. */ 1008 if (tp->t_flags & TF_RCVD_TSTMP) { 1009 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1010 to.to_tsecr = tp->ts_recent; 1011 to.to_flags |= TOF_TS; 1012 } 1013 #ifdef TCP_SIGNATURE 1014 /* TCP-MD5 (RFC2385). */ 1015 if (tp->t_flags & TF_SIGNATURE) 1016 to.to_flags |= TOF_SIGNATURE; 1017 #endif 1018 1019 /* Add the options. */ 1020 tlen += optlen = tcp_addoptions(&to, optp); 1021 1022 /* Update m_len in the correct mbuf. */ 1023 optm->m_len += optlen; 1024 } else 1025 optlen = 0; 1026 #ifdef INET6 1027 if (isipv6) { 1028 ip6->ip6_flow = 0; 1029 ip6->ip6_vfc = IPV6_VERSION; 1030 ip6->ip6_nxt = IPPROTO_TCP; 1031 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1032 } 1033 #endif 1034 #if defined(INET) && defined(INET6) 1035 else 1036 #endif 1037 #ifdef INET 1038 { 1039 ip->ip_len = htons(tlen); 1040 ip->ip_ttl = V_ip_defttl; 1041 if (V_path_mtu_discovery) 1042 ip->ip_off |= htons(IP_DF); 1043 } 1044 #endif 1045 m->m_pkthdr.len = tlen; 1046 m->m_pkthdr.rcvif = NULL; 1047 #ifdef MAC 1048 if (inp != NULL) { 1049 /* 1050 * Packet is associated with a socket, so allow the 1051 * label of the response to reflect the socket label. 1052 */ 1053 INP_WLOCK_ASSERT(inp); 1054 mac_inpcb_create_mbuf(inp, m); 1055 } else { 1056 /* 1057 * Packet is not associated with a socket, so possibly 1058 * update the label in place. 1059 */ 1060 mac_netinet_tcp_reply(m); 1061 } 1062 #endif 1063 nth->th_seq = htonl(seq); 1064 nth->th_ack = htonl(ack); 1065 nth->th_x2 = 0; 1066 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1067 nth->th_flags = flags; 1068 if (tp != NULL) 1069 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1070 else 1071 nth->th_win = htons((u_short)win); 1072 nth->th_urp = 0; 1073 1074 #ifdef TCP_SIGNATURE 1075 if (to.to_flags & TOF_SIGNATURE) { 1076 tcp_signature_compute(m, 0, 0, optlen, to.to_signature, 1077 IPSEC_DIR_OUTBOUND); 1078 } 1079 #endif 1080 1081 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1082 #ifdef INET6 1083 if (isipv6) { 1084 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1085 nth->th_sum = in6_cksum_pseudo(ip6, 1086 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1087 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1088 NULL, NULL); 1089 } 1090 #endif /* INET6 */ 1091 #if defined(INET6) && defined(INET) 1092 else 1093 #endif 1094 #ifdef INET 1095 { 1096 m->m_pkthdr.csum_flags = CSUM_TCP; 1097 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1098 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1099 } 1100 #endif /* INET */ 1101 #ifdef TCPDEBUG 1102 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1103 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1104 #endif 1105 TCP_PROBE3(debug__output, tp, th, mtod(m, const char *)); 1106 if (flags & TH_RST) 1107 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1108 tp, nth); 1109 1110 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1111 #ifdef INET6 1112 if (isipv6) 1113 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1114 #endif /* INET6 */ 1115 #if defined(INET) && defined(INET6) 1116 else 1117 #endif 1118 #ifdef INET 1119 (void) ip_output(m, NULL, NULL, 0, NULL, inp); 1120 #endif 1121 } 1122 1123 /* 1124 * Create a new TCP control block, making an 1125 * empty reassembly queue and hooking it to the argument 1126 * protocol control block. The `inp' parameter must have 1127 * come from the zone allocator set up in tcp_init(). 1128 */ 1129 struct tcpcb * 1130 tcp_newtcpcb(struct inpcb *inp) 1131 { 1132 struct tcpcb_mem *tm; 1133 struct tcpcb *tp; 1134 #ifdef INET6 1135 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1136 #endif /* INET6 */ 1137 1138 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1139 if (tm == NULL) 1140 return (NULL); 1141 tp = &tm->tcb; 1142 1143 /* Initialise cc_var struct for this tcpcb. */ 1144 tp->ccv = &tm->ccv; 1145 tp->ccv->type = IPPROTO_TCP; 1146 tp->ccv->ccvc.tcp = tp; 1147 rw_rlock(&tcp_function_lock); 1148 tp->t_fb = tcp_func_set_ptr; 1149 refcount_acquire(&tp->t_fb->tfb_refcnt); 1150 rw_runlock(&tcp_function_lock); 1151 if (tp->t_fb->tfb_tcp_fb_init) { 1152 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1153 } 1154 /* 1155 * Use the current system default CC algorithm. 1156 */ 1157 CC_LIST_RLOCK(); 1158 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1159 CC_ALGO(tp) = CC_DEFAULT(); 1160 CC_LIST_RUNLOCK(); 1161 1162 if (CC_ALGO(tp)->cb_init != NULL) 1163 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1164 if (tp->t_fb->tfb_tcp_fb_fini) 1165 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1166 refcount_release(&tp->t_fb->tfb_refcnt); 1167 uma_zfree(V_tcpcb_zone, tm); 1168 return (NULL); 1169 } 1170 1171 tp->osd = &tm->osd; 1172 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1173 if (tp->t_fb->tfb_tcp_fb_fini) 1174 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1175 refcount_release(&tp->t_fb->tfb_refcnt); 1176 uma_zfree(V_tcpcb_zone, tm); 1177 return (NULL); 1178 } 1179 1180 #ifdef VIMAGE 1181 tp->t_vnet = inp->inp_vnet; 1182 #endif 1183 tp->t_timers = &tm->tt; 1184 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1185 tp->t_maxseg = 1186 #ifdef INET6 1187 isipv6 ? V_tcp_v6mssdflt : 1188 #endif /* INET6 */ 1189 V_tcp_mssdflt; 1190 1191 /* Set up our timeouts. */ 1192 callout_init(&tp->t_timers->tt_rexmt, 1); 1193 callout_init(&tp->t_timers->tt_persist, 1); 1194 callout_init(&tp->t_timers->tt_keep, 1); 1195 callout_init(&tp->t_timers->tt_2msl, 1); 1196 callout_init(&tp->t_timers->tt_delack, 1); 1197 1198 if (V_tcp_do_rfc1323) 1199 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1200 if (V_tcp_do_sack) 1201 tp->t_flags |= TF_SACK_PERMIT; 1202 TAILQ_INIT(&tp->snd_holes); 1203 /* 1204 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1205 * is called. 1206 */ 1207 in_pcbref(inp); /* Reference for tcpcb */ 1208 tp->t_inpcb = inp; 1209 1210 /* 1211 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1212 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1213 * reasonable initial retransmit time. 1214 */ 1215 tp->t_srtt = TCPTV_SRTTBASE; 1216 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1217 tp->t_rttmin = tcp_rexmit_min; 1218 tp->t_rxtcur = TCPTV_RTOBASE; 1219 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1220 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1221 tp->t_rcvtime = ticks; 1222 /* 1223 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1224 * because the socket may be bound to an IPv6 wildcard address, 1225 * which may match an IPv4-mapped IPv6 address. 1226 */ 1227 inp->inp_ip_ttl = V_ip_defttl; 1228 inp->inp_ppcb = tp; 1229 #ifdef TCPPCAP 1230 /* 1231 * Init the TCP PCAP queues. 1232 */ 1233 tcp_pcap_tcpcb_init(tp); 1234 #endif 1235 return (tp); /* XXX */ 1236 } 1237 1238 /* 1239 * Switch the congestion control algorithm back to NewReno for any active 1240 * control blocks using an algorithm which is about to go away. 1241 * This ensures the CC framework can allow the unload to proceed without leaving 1242 * any dangling pointers which would trigger a panic. 1243 * Returning non-zero would inform the CC framework that something went wrong 1244 * and it would be unsafe to allow the unload to proceed. However, there is no 1245 * way for this to occur with this implementation so we always return zero. 1246 */ 1247 int 1248 tcp_ccalgounload(struct cc_algo *unload_algo) 1249 { 1250 struct cc_algo *tmpalgo; 1251 struct inpcb *inp; 1252 struct tcpcb *tp; 1253 VNET_ITERATOR_DECL(vnet_iter); 1254 1255 /* 1256 * Check all active control blocks across all network stacks and change 1257 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1258 * requires cleanup code to be run, call it. 1259 */ 1260 VNET_LIST_RLOCK(); 1261 VNET_FOREACH(vnet_iter) { 1262 CURVNET_SET(vnet_iter); 1263 INP_INFO_WLOCK(&V_tcbinfo); 1264 /* 1265 * New connections already part way through being initialised 1266 * with the CC algo we're removing will not race with this code 1267 * because the INP_INFO_WLOCK is held during initialisation. We 1268 * therefore don't enter the loop below until the connection 1269 * list has stabilised. 1270 */ 1271 LIST_FOREACH(inp, &V_tcb, inp_list) { 1272 INP_WLOCK(inp); 1273 /* Important to skip tcptw structs. */ 1274 if (!(inp->inp_flags & INP_TIMEWAIT) && 1275 (tp = intotcpcb(inp)) != NULL) { 1276 /* 1277 * By holding INP_WLOCK here, we are assured 1278 * that the connection is not currently 1279 * executing inside the CC module's functions 1280 * i.e. it is safe to make the switch back to 1281 * NewReno. 1282 */ 1283 if (CC_ALGO(tp) == unload_algo) { 1284 tmpalgo = CC_ALGO(tp); 1285 /* NewReno does not require any init. */ 1286 CC_ALGO(tp) = &newreno_cc_algo; 1287 if (tmpalgo->cb_destroy != NULL) 1288 tmpalgo->cb_destroy(tp->ccv); 1289 } 1290 } 1291 INP_WUNLOCK(inp); 1292 } 1293 INP_INFO_WUNLOCK(&V_tcbinfo); 1294 CURVNET_RESTORE(); 1295 } 1296 VNET_LIST_RUNLOCK(); 1297 1298 return (0); 1299 } 1300 1301 /* 1302 * Drop a TCP connection, reporting 1303 * the specified error. If connection is synchronized, 1304 * then send a RST to peer. 1305 */ 1306 struct tcpcb * 1307 tcp_drop(struct tcpcb *tp, int errno) 1308 { 1309 struct socket *so = tp->t_inpcb->inp_socket; 1310 1311 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1312 INP_WLOCK_ASSERT(tp->t_inpcb); 1313 1314 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1315 tcp_state_change(tp, TCPS_CLOSED); 1316 (void) tp->t_fb->tfb_tcp_output(tp); 1317 TCPSTAT_INC(tcps_drops); 1318 } else 1319 TCPSTAT_INC(tcps_conndrops); 1320 if (errno == ETIMEDOUT && tp->t_softerror) 1321 errno = tp->t_softerror; 1322 so->so_error = errno; 1323 return (tcp_close(tp)); 1324 } 1325 1326 void 1327 tcp_discardcb(struct tcpcb *tp) 1328 { 1329 struct inpcb *inp = tp->t_inpcb; 1330 struct socket *so = inp->inp_socket; 1331 #ifdef INET6 1332 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1333 #endif /* INET6 */ 1334 int released; 1335 1336 INP_WLOCK_ASSERT(inp); 1337 1338 /* 1339 * Make sure that all of our timers are stopped before we delete the 1340 * PCB. 1341 * 1342 * If stopping a timer fails, we schedule a discard function in same 1343 * callout, and the last discard function called will take care of 1344 * deleting the tcpcb. 1345 */ 1346 tcp_timer_stop(tp, TT_REXMT); 1347 tcp_timer_stop(tp, TT_PERSIST); 1348 tcp_timer_stop(tp, TT_KEEP); 1349 tcp_timer_stop(tp, TT_2MSL); 1350 tcp_timer_stop(tp, TT_DELACK); 1351 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1352 /* Call the stop-all function of the methods */ 1353 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1354 } 1355 1356 /* 1357 * If we got enough samples through the srtt filter, 1358 * save the rtt and rttvar in the routing entry. 1359 * 'Enough' is arbitrarily defined as 4 rtt samples. 1360 * 4 samples is enough for the srtt filter to converge 1361 * to within enough % of the correct value; fewer samples 1362 * and we could save a bogus rtt. The danger is not high 1363 * as tcp quickly recovers from everything. 1364 * XXX: Works very well but needs some more statistics! 1365 */ 1366 if (tp->t_rttupdated >= 4) { 1367 struct hc_metrics_lite metrics; 1368 u_long ssthresh; 1369 1370 bzero(&metrics, sizeof(metrics)); 1371 /* 1372 * Update the ssthresh always when the conditions below 1373 * are satisfied. This gives us better new start value 1374 * for the congestion avoidance for new connections. 1375 * ssthresh is only set if packet loss occured on a session. 1376 * 1377 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1378 * being torn down. Ideally this code would not use 'so'. 1379 */ 1380 ssthresh = tp->snd_ssthresh; 1381 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1382 /* 1383 * convert the limit from user data bytes to 1384 * packets then to packet data bytes. 1385 */ 1386 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1387 if (ssthresh < 2) 1388 ssthresh = 2; 1389 ssthresh *= (u_long)(tp->t_maxseg + 1390 #ifdef INET6 1391 (isipv6 ? sizeof (struct ip6_hdr) + 1392 sizeof (struct tcphdr) : 1393 #endif 1394 sizeof (struct tcpiphdr) 1395 #ifdef INET6 1396 ) 1397 #endif 1398 ); 1399 } else 1400 ssthresh = 0; 1401 metrics.rmx_ssthresh = ssthresh; 1402 1403 metrics.rmx_rtt = tp->t_srtt; 1404 metrics.rmx_rttvar = tp->t_rttvar; 1405 metrics.rmx_cwnd = tp->snd_cwnd; 1406 metrics.rmx_sendpipe = 0; 1407 metrics.rmx_recvpipe = 0; 1408 1409 tcp_hc_update(&inp->inp_inc, &metrics); 1410 } 1411 1412 /* free the reassembly queue, if any */ 1413 tcp_reass_flush(tp); 1414 1415 #ifdef TCP_OFFLOAD 1416 /* Disconnect offload device, if any. */ 1417 if (tp->t_flags & TF_TOE) 1418 tcp_offload_detach(tp); 1419 #endif 1420 1421 tcp_free_sackholes(tp); 1422 1423 #ifdef TCPPCAP 1424 /* Free the TCP PCAP queues. */ 1425 tcp_pcap_drain(&(tp->t_inpkts)); 1426 tcp_pcap_drain(&(tp->t_outpkts)); 1427 #endif 1428 1429 /* Allow the CC algorithm to clean up after itself. */ 1430 if (CC_ALGO(tp)->cb_destroy != NULL) 1431 CC_ALGO(tp)->cb_destroy(tp->ccv); 1432 1433 khelp_destroy_osd(tp->osd); 1434 1435 CC_ALGO(tp) = NULL; 1436 inp->inp_ppcb = NULL; 1437 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1438 /* We own the last reference on tcpcb, let's free it. */ 1439 if ((tp->t_fb->tfb_tcp_timers_left) && 1440 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1441 /* Some fb timers left running! */ 1442 return; 1443 } 1444 if (tp->t_fb->tfb_tcp_fb_fini) 1445 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1446 refcount_release(&tp->t_fb->tfb_refcnt); 1447 tp->t_inpcb = NULL; 1448 uma_zfree(V_tcpcb_zone, tp); 1449 released = in_pcbrele_wlocked(inp); 1450 KASSERT(!released, ("%s: inp %p should not have been released " 1451 "here", __func__, inp)); 1452 } 1453 } 1454 1455 void 1456 tcp_timer_2msl_discard(void *xtp) 1457 { 1458 1459 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1460 } 1461 1462 void 1463 tcp_timer_keep_discard(void *xtp) 1464 { 1465 1466 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1467 } 1468 1469 void 1470 tcp_timer_persist_discard(void *xtp) 1471 { 1472 1473 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1474 } 1475 1476 void 1477 tcp_timer_rexmt_discard(void *xtp) 1478 { 1479 1480 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1481 } 1482 1483 void 1484 tcp_timer_delack_discard(void *xtp) 1485 { 1486 1487 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1488 } 1489 1490 void 1491 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1492 { 1493 struct inpcb *inp; 1494 1495 CURVNET_SET(tp->t_vnet); 1496 INP_INFO_RLOCK(&V_tcbinfo); 1497 inp = tp->t_inpcb; 1498 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1499 __func__, tp)); 1500 INP_WLOCK(inp); 1501 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1502 ("%s: tcpcb has to be stopped here", __func__)); 1503 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1504 ("%s: discard callout should be running", __func__)); 1505 tp->t_timers->tt_flags &= ~timer_type; 1506 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1507 /* We own the last reference on this tcpcb, let's free it. */ 1508 if ((tp->t_fb->tfb_tcp_timers_left) && 1509 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1510 /* Some fb timers left running! */ 1511 goto leave; 1512 } 1513 if (tp->t_fb->tfb_tcp_fb_fini) 1514 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1515 refcount_release(&tp->t_fb->tfb_refcnt); 1516 tp->t_inpcb = NULL; 1517 uma_zfree(V_tcpcb_zone, tp); 1518 if (in_pcbrele_wlocked(inp)) { 1519 INP_INFO_RUNLOCK(&V_tcbinfo); 1520 CURVNET_RESTORE(); 1521 return; 1522 } 1523 } 1524 leave: 1525 INP_WUNLOCK(inp); 1526 INP_INFO_RUNLOCK(&V_tcbinfo); 1527 CURVNET_RESTORE(); 1528 } 1529 1530 /* 1531 * Attempt to close a TCP control block, marking it as dropped, and freeing 1532 * the socket if we hold the only reference. 1533 */ 1534 struct tcpcb * 1535 tcp_close(struct tcpcb *tp) 1536 { 1537 struct inpcb *inp = tp->t_inpcb; 1538 struct socket *so; 1539 1540 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1541 INP_WLOCK_ASSERT(inp); 1542 1543 #ifdef TCP_OFFLOAD 1544 if (tp->t_state == TCPS_LISTEN) 1545 tcp_offload_listen_stop(tp); 1546 #endif 1547 #ifdef TCP_RFC7413 1548 /* 1549 * This releases the TFO pending counter resource for TFO listen 1550 * sockets as well as passively-created TFO sockets that transition 1551 * from SYN_RECEIVED to CLOSED. 1552 */ 1553 if (tp->t_tfo_pending) { 1554 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1555 tp->t_tfo_pending = NULL; 1556 } 1557 #endif 1558 in_pcbdrop(inp); 1559 TCPSTAT_INC(tcps_closed); 1560 TCPSTATES_DEC(tp->t_state); 1561 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1562 so = inp->inp_socket; 1563 soisdisconnected(so); 1564 if (inp->inp_flags & INP_SOCKREF) { 1565 KASSERT(so->so_state & SS_PROTOREF, 1566 ("tcp_close: !SS_PROTOREF")); 1567 inp->inp_flags &= ~INP_SOCKREF; 1568 INP_WUNLOCK(inp); 1569 ACCEPT_LOCK(); 1570 SOCK_LOCK(so); 1571 so->so_state &= ~SS_PROTOREF; 1572 sofree(so); 1573 return (NULL); 1574 } 1575 return (tp); 1576 } 1577 1578 void 1579 tcp_drain(void) 1580 { 1581 VNET_ITERATOR_DECL(vnet_iter); 1582 1583 if (!do_tcpdrain) 1584 return; 1585 1586 VNET_LIST_RLOCK_NOSLEEP(); 1587 VNET_FOREACH(vnet_iter) { 1588 CURVNET_SET(vnet_iter); 1589 struct inpcb *inpb; 1590 struct tcpcb *tcpb; 1591 1592 /* 1593 * Walk the tcpbs, if existing, and flush the reassembly queue, 1594 * if there is one... 1595 * XXX: The "Net/3" implementation doesn't imply that the TCP 1596 * reassembly queue should be flushed, but in a situation 1597 * where we're really low on mbufs, this is potentially 1598 * useful. 1599 */ 1600 INP_INFO_WLOCK(&V_tcbinfo); 1601 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1602 if (inpb->inp_flags & INP_TIMEWAIT) 1603 continue; 1604 INP_WLOCK(inpb); 1605 if ((tcpb = intotcpcb(inpb)) != NULL) { 1606 tcp_reass_flush(tcpb); 1607 tcp_clean_sackreport(tcpb); 1608 } 1609 INP_WUNLOCK(inpb); 1610 } 1611 INP_INFO_WUNLOCK(&V_tcbinfo); 1612 CURVNET_RESTORE(); 1613 } 1614 VNET_LIST_RUNLOCK_NOSLEEP(); 1615 } 1616 1617 /* 1618 * Notify a tcp user of an asynchronous error; 1619 * store error as soft error, but wake up user 1620 * (for now, won't do anything until can select for soft error). 1621 * 1622 * Do not wake up user since there currently is no mechanism for 1623 * reporting soft errors (yet - a kqueue filter may be added). 1624 */ 1625 static struct inpcb * 1626 tcp_notify(struct inpcb *inp, int error) 1627 { 1628 struct tcpcb *tp; 1629 1630 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1631 INP_WLOCK_ASSERT(inp); 1632 1633 if ((inp->inp_flags & INP_TIMEWAIT) || 1634 (inp->inp_flags & INP_DROPPED)) 1635 return (inp); 1636 1637 tp = intotcpcb(inp); 1638 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1639 1640 /* 1641 * Ignore some errors if we are hooked up. 1642 * If connection hasn't completed, has retransmitted several times, 1643 * and receives a second error, give up now. This is better 1644 * than waiting a long time to establish a connection that 1645 * can never complete. 1646 */ 1647 if (tp->t_state == TCPS_ESTABLISHED && 1648 (error == EHOSTUNREACH || error == ENETUNREACH || 1649 error == EHOSTDOWN)) { 1650 if (inp->inp_route.ro_rt) { 1651 RTFREE(inp->inp_route.ro_rt); 1652 inp->inp_route.ro_rt = (struct rtentry *)NULL; 1653 } 1654 return (inp); 1655 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1656 tp->t_softerror) { 1657 tp = tcp_drop(tp, error); 1658 if (tp != NULL) 1659 return (inp); 1660 else 1661 return (NULL); 1662 } else { 1663 tp->t_softerror = error; 1664 return (inp); 1665 } 1666 #if 0 1667 wakeup( &so->so_timeo); 1668 sorwakeup(so); 1669 sowwakeup(so); 1670 #endif 1671 } 1672 1673 static int 1674 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1675 { 1676 int error, i, m, n, pcb_count; 1677 struct inpcb *inp, **inp_list; 1678 inp_gen_t gencnt; 1679 struct xinpgen xig; 1680 1681 /* 1682 * The process of preparing the TCB list is too time-consuming and 1683 * resource-intensive to repeat twice on every request. 1684 */ 1685 if (req->oldptr == NULL) { 1686 n = V_tcbinfo.ipi_count + 1687 counter_u64_fetch(VNET(tcps_states)[TCPS_SYN_RECEIVED]); 1688 n += imax(n / 8, 10); 1689 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1690 return (0); 1691 } 1692 1693 if (req->newptr != NULL) 1694 return (EPERM); 1695 1696 /* 1697 * OK, now we're committed to doing something. 1698 */ 1699 INP_LIST_RLOCK(&V_tcbinfo); 1700 gencnt = V_tcbinfo.ipi_gencnt; 1701 n = V_tcbinfo.ipi_count; 1702 INP_LIST_RUNLOCK(&V_tcbinfo); 1703 1704 m = counter_u64_fetch(VNET(tcps_states)[TCPS_SYN_RECEIVED]); 1705 1706 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1707 + (n + m) * sizeof(struct xtcpcb)); 1708 if (error != 0) 1709 return (error); 1710 1711 xig.xig_len = sizeof xig; 1712 xig.xig_count = n + m; 1713 xig.xig_gen = gencnt; 1714 xig.xig_sogen = so_gencnt; 1715 error = SYSCTL_OUT(req, &xig, sizeof xig); 1716 if (error) 1717 return (error); 1718 1719 error = syncache_pcblist(req, m, &pcb_count); 1720 if (error) 1721 return (error); 1722 1723 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1724 1725 INP_INFO_WLOCK(&V_tcbinfo); 1726 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1727 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1728 INP_WLOCK(inp); 1729 if (inp->inp_gencnt <= gencnt) { 1730 /* 1731 * XXX: This use of cr_cansee(), introduced with 1732 * TCP state changes, is not quite right, but for 1733 * now, better than nothing. 1734 */ 1735 if (inp->inp_flags & INP_TIMEWAIT) { 1736 if (intotw(inp) != NULL) 1737 error = cr_cansee(req->td->td_ucred, 1738 intotw(inp)->tw_cred); 1739 else 1740 error = EINVAL; /* Skip this inp. */ 1741 } else 1742 error = cr_canseeinpcb(req->td->td_ucred, inp); 1743 if (error == 0) { 1744 in_pcbref(inp); 1745 inp_list[i++] = inp; 1746 } 1747 } 1748 INP_WUNLOCK(inp); 1749 } 1750 INP_INFO_WUNLOCK(&V_tcbinfo); 1751 n = i; 1752 1753 error = 0; 1754 for (i = 0; i < n; i++) { 1755 inp = inp_list[i]; 1756 INP_RLOCK(inp); 1757 if (inp->inp_gencnt <= gencnt) { 1758 struct xtcpcb xt; 1759 void *inp_ppcb; 1760 1761 bzero(&xt, sizeof(xt)); 1762 xt.xt_len = sizeof xt; 1763 /* XXX should avoid extra copy */ 1764 bcopy(inp, &xt.xt_inp, sizeof *inp); 1765 inp_ppcb = inp->inp_ppcb; 1766 if (inp_ppcb == NULL) 1767 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1768 else if (inp->inp_flags & INP_TIMEWAIT) { 1769 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1770 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1771 } else { 1772 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1773 if (xt.xt_tp.t_timers) 1774 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1775 } 1776 if (inp->inp_socket != NULL) 1777 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1778 else { 1779 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1780 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1781 } 1782 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1783 INP_RUNLOCK(inp); 1784 error = SYSCTL_OUT(req, &xt, sizeof xt); 1785 } else 1786 INP_RUNLOCK(inp); 1787 } 1788 INP_INFO_RLOCK(&V_tcbinfo); 1789 for (i = 0; i < n; i++) { 1790 inp = inp_list[i]; 1791 INP_RLOCK(inp); 1792 if (!in_pcbrele_rlocked(inp)) 1793 INP_RUNLOCK(inp); 1794 } 1795 INP_INFO_RUNLOCK(&V_tcbinfo); 1796 1797 if (!error) { 1798 /* 1799 * Give the user an updated idea of our state. 1800 * If the generation differs from what we told 1801 * her before, she knows that something happened 1802 * while we were processing this request, and it 1803 * might be necessary to retry. 1804 */ 1805 INP_LIST_RLOCK(&V_tcbinfo); 1806 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1807 xig.xig_sogen = so_gencnt; 1808 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1809 INP_LIST_RUNLOCK(&V_tcbinfo); 1810 error = SYSCTL_OUT(req, &xig, sizeof xig); 1811 } 1812 free(inp_list, M_TEMP); 1813 return (error); 1814 } 1815 1816 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1817 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1818 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1819 1820 #ifdef INET 1821 static int 1822 tcp_getcred(SYSCTL_HANDLER_ARGS) 1823 { 1824 struct xucred xuc; 1825 struct sockaddr_in addrs[2]; 1826 struct inpcb *inp; 1827 int error; 1828 1829 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1830 if (error) 1831 return (error); 1832 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1833 if (error) 1834 return (error); 1835 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1836 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1837 if (inp != NULL) { 1838 if (inp->inp_socket == NULL) 1839 error = ENOENT; 1840 if (error == 0) 1841 error = cr_canseeinpcb(req->td->td_ucred, inp); 1842 if (error == 0) 1843 cru2x(inp->inp_cred, &xuc); 1844 INP_RUNLOCK(inp); 1845 } else 1846 error = ENOENT; 1847 if (error == 0) 1848 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1849 return (error); 1850 } 1851 1852 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1853 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1854 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1855 #endif /* INET */ 1856 1857 #ifdef INET6 1858 static int 1859 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1860 { 1861 struct xucred xuc; 1862 struct sockaddr_in6 addrs[2]; 1863 struct inpcb *inp; 1864 int error; 1865 #ifdef INET 1866 int mapped = 0; 1867 #endif 1868 1869 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1870 if (error) 1871 return (error); 1872 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1873 if (error) 1874 return (error); 1875 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1876 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1877 return (error); 1878 } 1879 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1880 #ifdef INET 1881 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1882 mapped = 1; 1883 else 1884 #endif 1885 return (EINVAL); 1886 } 1887 1888 #ifdef INET 1889 if (mapped == 1) 1890 inp = in_pcblookup(&V_tcbinfo, 1891 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1892 addrs[1].sin6_port, 1893 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1894 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1895 else 1896 #endif 1897 inp = in6_pcblookup(&V_tcbinfo, 1898 &addrs[1].sin6_addr, addrs[1].sin6_port, 1899 &addrs[0].sin6_addr, addrs[0].sin6_port, 1900 INPLOOKUP_RLOCKPCB, NULL); 1901 if (inp != NULL) { 1902 if (inp->inp_socket == NULL) 1903 error = ENOENT; 1904 if (error == 0) 1905 error = cr_canseeinpcb(req->td->td_ucred, inp); 1906 if (error == 0) 1907 cru2x(inp->inp_cred, &xuc); 1908 INP_RUNLOCK(inp); 1909 } else 1910 error = ENOENT; 1911 if (error == 0) 1912 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1913 return (error); 1914 } 1915 1916 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1917 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1918 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1919 #endif /* INET6 */ 1920 1921 1922 #ifdef INET 1923 void 1924 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1925 { 1926 struct ip *ip = vip; 1927 struct tcphdr *th; 1928 struct in_addr faddr; 1929 struct inpcb *inp; 1930 struct tcpcb *tp; 1931 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1932 struct icmp *icp; 1933 struct in_conninfo inc; 1934 tcp_seq icmp_tcp_seq; 1935 int mtu; 1936 1937 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1938 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1939 return; 1940 1941 if (cmd == PRC_MSGSIZE) 1942 notify = tcp_mtudisc_notify; 1943 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1944 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1945 notify = tcp_drop_syn_sent; 1946 else if (PRC_IS_REDIRECT(cmd)) { 1947 /* signal EHOSTDOWN, as it flushes the cached route */ 1948 in_pcbnotifyall(&V_tcbinfo, faddr, EHOSTDOWN, notify); 1949 return; 1950 } 1951 /* 1952 * Hostdead is ugly because it goes linearly through all PCBs. 1953 * XXX: We never get this from ICMP, otherwise it makes an 1954 * excellent DoS attack on machines with many connections. 1955 */ 1956 else if (cmd == PRC_HOSTDEAD) 1957 ip = NULL; 1958 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1959 return; 1960 1961 if (ip == NULL) { 1962 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1963 return; 1964 } 1965 1966 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1967 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1968 INP_INFO_RLOCK(&V_tcbinfo); 1969 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1970 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1971 if (inp != NULL) { 1972 if (!(inp->inp_flags & INP_TIMEWAIT) && 1973 !(inp->inp_flags & INP_DROPPED) && 1974 !(inp->inp_socket == NULL)) { 1975 icmp_tcp_seq = ntohl(th->th_seq); 1976 tp = intotcpcb(inp); 1977 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1978 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1979 if (cmd == PRC_MSGSIZE) { 1980 /* 1981 * MTU discovery: 1982 * If we got a needfrag set the MTU 1983 * in the route to the suggested new 1984 * value (if given) and then notify. 1985 */ 1986 mtu = ntohs(icp->icmp_nextmtu); 1987 /* 1988 * If no alternative MTU was 1989 * proposed, try the next smaller 1990 * one. 1991 */ 1992 if (!mtu) 1993 mtu = ip_next_mtu( 1994 ntohs(ip->ip_len), 1); 1995 if (mtu < V_tcp_minmss + 1996 sizeof(struct tcpiphdr)) 1997 mtu = V_tcp_minmss + 1998 sizeof(struct tcpiphdr); 1999 /* 2000 * Only process the offered MTU if it 2001 * is smaller than the current one. 2002 */ 2003 if (mtu < tp->t_maxseg + 2004 sizeof(struct tcpiphdr)) { 2005 bzero(&inc, sizeof(inc)); 2006 inc.inc_faddr = faddr; 2007 inc.inc_fibnum = 2008 inp->inp_inc.inc_fibnum; 2009 tcp_hc_updatemtu(&inc, mtu); 2010 tcp_mtudisc(inp, mtu); 2011 } 2012 } else 2013 inp = (*notify)(inp, 2014 inetctlerrmap[cmd]); 2015 } 2016 } 2017 if (inp != NULL) 2018 INP_WUNLOCK(inp); 2019 } else { 2020 bzero(&inc, sizeof(inc)); 2021 inc.inc_fport = th->th_dport; 2022 inc.inc_lport = th->th_sport; 2023 inc.inc_faddr = faddr; 2024 inc.inc_laddr = ip->ip_src; 2025 syncache_unreach(&inc, th); 2026 } 2027 INP_INFO_RUNLOCK(&V_tcbinfo); 2028 } 2029 #endif /* INET */ 2030 2031 #ifdef INET6 2032 void 2033 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2034 { 2035 struct tcphdr th; 2036 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2037 struct ip6_hdr *ip6; 2038 struct mbuf *m; 2039 struct ip6ctlparam *ip6cp = NULL; 2040 const struct sockaddr_in6 *sa6_src = NULL; 2041 int off; 2042 struct tcp_portonly { 2043 u_int16_t th_sport; 2044 u_int16_t th_dport; 2045 } *thp; 2046 2047 if (sa->sa_family != AF_INET6 || 2048 sa->sa_len != sizeof(struct sockaddr_in6)) 2049 return; 2050 2051 if (cmd == PRC_MSGSIZE) 2052 notify = tcp_mtudisc_notify; 2053 else if (!PRC_IS_REDIRECT(cmd) && 2054 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 2055 return; 2056 2057 /* if the parameter is from icmp6, decode it. */ 2058 if (d != NULL) { 2059 ip6cp = (struct ip6ctlparam *)d; 2060 m = ip6cp->ip6c_m; 2061 ip6 = ip6cp->ip6c_ip6; 2062 off = ip6cp->ip6c_off; 2063 sa6_src = ip6cp->ip6c_src; 2064 } else { 2065 m = NULL; 2066 ip6 = NULL; 2067 off = 0; /* fool gcc */ 2068 sa6_src = &sa6_any; 2069 } 2070 2071 if (ip6 != NULL) { 2072 struct in_conninfo inc; 2073 /* 2074 * XXX: We assume that when IPV6 is non NULL, 2075 * M and OFF are valid. 2076 */ 2077 2078 /* check if we can safely examine src and dst ports */ 2079 if (m->m_pkthdr.len < off + sizeof(*thp)) 2080 return; 2081 2082 bzero(&th, sizeof(th)); 2083 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 2084 2085 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 2086 (struct sockaddr *)ip6cp->ip6c_src, 2087 th.th_sport, cmd, NULL, notify); 2088 2089 bzero(&inc, sizeof(inc)); 2090 inc.inc_fport = th.th_dport; 2091 inc.inc_lport = th.th_sport; 2092 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 2093 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 2094 inc.inc_flags |= INC_ISIPV6; 2095 INP_INFO_RLOCK(&V_tcbinfo); 2096 syncache_unreach(&inc, &th); 2097 INP_INFO_RUNLOCK(&V_tcbinfo); 2098 } else 2099 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 2100 0, cmd, NULL, notify); 2101 } 2102 #endif /* INET6 */ 2103 2104 2105 /* 2106 * Following is where TCP initial sequence number generation occurs. 2107 * 2108 * There are two places where we must use initial sequence numbers: 2109 * 1. In SYN-ACK packets. 2110 * 2. In SYN packets. 2111 * 2112 * All ISNs for SYN-ACK packets are generated by the syncache. See 2113 * tcp_syncache.c for details. 2114 * 2115 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2116 * depends on this property. In addition, these ISNs should be 2117 * unguessable so as to prevent connection hijacking. To satisfy 2118 * the requirements of this situation, the algorithm outlined in 2119 * RFC 1948 is used, with only small modifications. 2120 * 2121 * Implementation details: 2122 * 2123 * Time is based off the system timer, and is corrected so that it 2124 * increases by one megabyte per second. This allows for proper 2125 * recycling on high speed LANs while still leaving over an hour 2126 * before rollover. 2127 * 2128 * As reading the *exact* system time is too expensive to be done 2129 * whenever setting up a TCP connection, we increment the time 2130 * offset in two ways. First, a small random positive increment 2131 * is added to isn_offset for each connection that is set up. 2132 * Second, the function tcp_isn_tick fires once per clock tick 2133 * and increments isn_offset as necessary so that sequence numbers 2134 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2135 * random positive increments serve only to ensure that the same 2136 * exact sequence number is never sent out twice (as could otherwise 2137 * happen when a port is recycled in less than the system tick 2138 * interval.) 2139 * 2140 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2141 * between seeding of isn_secret. This is normally set to zero, 2142 * as reseeding should not be necessary. 2143 * 2144 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2145 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2146 * general, this means holding an exclusive (write) lock. 2147 */ 2148 2149 #define ISN_BYTES_PER_SECOND 1048576 2150 #define ISN_STATIC_INCREMENT 4096 2151 #define ISN_RANDOM_INCREMENT (4096 - 1) 2152 2153 static VNET_DEFINE(u_char, isn_secret[32]); 2154 static VNET_DEFINE(int, isn_last); 2155 static VNET_DEFINE(int, isn_last_reseed); 2156 static VNET_DEFINE(u_int32_t, isn_offset); 2157 static VNET_DEFINE(u_int32_t, isn_offset_old); 2158 2159 #define V_isn_secret VNET(isn_secret) 2160 #define V_isn_last VNET(isn_last) 2161 #define V_isn_last_reseed VNET(isn_last_reseed) 2162 #define V_isn_offset VNET(isn_offset) 2163 #define V_isn_offset_old VNET(isn_offset_old) 2164 2165 tcp_seq 2166 tcp_new_isn(struct tcpcb *tp) 2167 { 2168 MD5_CTX isn_ctx; 2169 u_int32_t md5_buffer[4]; 2170 tcp_seq new_isn; 2171 u_int32_t projected_offset; 2172 2173 INP_WLOCK_ASSERT(tp->t_inpcb); 2174 2175 ISN_LOCK(); 2176 /* Seed if this is the first use, reseed if requested. */ 2177 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2178 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2179 < (u_int)ticks))) { 2180 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2181 V_isn_last_reseed = ticks; 2182 } 2183 2184 /* Compute the md5 hash and return the ISN. */ 2185 MD5Init(&isn_ctx); 2186 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2187 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2188 #ifdef INET6 2189 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2190 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2191 sizeof(struct in6_addr)); 2192 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2193 sizeof(struct in6_addr)); 2194 } else 2195 #endif 2196 { 2197 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2198 sizeof(struct in_addr)); 2199 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2200 sizeof(struct in_addr)); 2201 } 2202 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2203 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2204 new_isn = (tcp_seq) md5_buffer[0]; 2205 V_isn_offset += ISN_STATIC_INCREMENT + 2206 (arc4random() & ISN_RANDOM_INCREMENT); 2207 if (ticks != V_isn_last) { 2208 projected_offset = V_isn_offset_old + 2209 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2210 if (SEQ_GT(projected_offset, V_isn_offset)) 2211 V_isn_offset = projected_offset; 2212 V_isn_offset_old = V_isn_offset; 2213 V_isn_last = ticks; 2214 } 2215 new_isn += V_isn_offset; 2216 ISN_UNLOCK(); 2217 return (new_isn); 2218 } 2219 2220 /* 2221 * When a specific ICMP unreachable message is received and the 2222 * connection state is SYN-SENT, drop the connection. This behavior 2223 * is controlled by the icmp_may_rst sysctl. 2224 */ 2225 struct inpcb * 2226 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2227 { 2228 struct tcpcb *tp; 2229 2230 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2231 INP_WLOCK_ASSERT(inp); 2232 2233 if ((inp->inp_flags & INP_TIMEWAIT) || 2234 (inp->inp_flags & INP_DROPPED)) 2235 return (inp); 2236 2237 tp = intotcpcb(inp); 2238 if (tp->t_state != TCPS_SYN_SENT) 2239 return (inp); 2240 2241 tp = tcp_drop(tp, errno); 2242 if (tp != NULL) 2243 return (inp); 2244 else 2245 return (NULL); 2246 } 2247 2248 /* 2249 * When `need fragmentation' ICMP is received, update our idea of the MSS 2250 * based on the new value. Also nudge TCP to send something, since we 2251 * know the packet we just sent was dropped. 2252 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2253 */ 2254 static struct inpcb * 2255 tcp_mtudisc_notify(struct inpcb *inp, int error) 2256 { 2257 2258 tcp_mtudisc(inp, -1); 2259 return (inp); 2260 } 2261 2262 static void 2263 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2264 { 2265 struct tcpcb *tp; 2266 struct socket *so; 2267 2268 INP_WLOCK_ASSERT(inp); 2269 if ((inp->inp_flags & INP_TIMEWAIT) || 2270 (inp->inp_flags & INP_DROPPED)) 2271 return; 2272 2273 tp = intotcpcb(inp); 2274 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2275 2276 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2277 2278 so = inp->inp_socket; 2279 SOCKBUF_LOCK(&so->so_snd); 2280 /* If the mss is larger than the socket buffer, decrease the mss. */ 2281 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2282 tp->t_maxseg = so->so_snd.sb_hiwat; 2283 SOCKBUF_UNLOCK(&so->so_snd); 2284 2285 TCPSTAT_INC(tcps_mturesent); 2286 tp->t_rtttime = 0; 2287 tp->snd_nxt = tp->snd_una; 2288 tcp_free_sackholes(tp); 2289 tp->snd_recover = tp->snd_max; 2290 if (tp->t_flags & TF_SACK_PERMIT) 2291 EXIT_FASTRECOVERY(tp->t_flags); 2292 tp->t_fb->tfb_tcp_output(tp); 2293 } 2294 2295 #ifdef INET 2296 /* 2297 * Look-up the routing entry to the peer of this inpcb. If no route 2298 * is found and it cannot be allocated, then return 0. This routine 2299 * is called by TCP routines that access the rmx structure and by 2300 * tcp_mss_update to get the peer/interface MTU. 2301 */ 2302 u_long 2303 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2304 { 2305 struct nhop4_extended nh4; 2306 struct ifnet *ifp; 2307 u_long maxmtu = 0; 2308 2309 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2310 2311 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2312 2313 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2314 NHR_REF, 0, &nh4) != 0) 2315 return (0); 2316 2317 ifp = nh4.nh_ifp; 2318 maxmtu = nh4.nh_mtu; 2319 2320 /* Report additional interface capabilities. */ 2321 if (cap != NULL) { 2322 if (ifp->if_capenable & IFCAP_TSO4 && 2323 ifp->if_hwassist & CSUM_TSO) { 2324 cap->ifcap |= CSUM_TSO; 2325 cap->tsomax = ifp->if_hw_tsomax; 2326 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2327 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2328 } 2329 } 2330 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2331 } 2332 return (maxmtu); 2333 } 2334 #endif /* INET */ 2335 2336 #ifdef INET6 2337 u_long 2338 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2339 { 2340 struct nhop6_extended nh6; 2341 struct in6_addr dst6; 2342 uint32_t scopeid; 2343 struct ifnet *ifp; 2344 u_long maxmtu = 0; 2345 2346 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2347 2348 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2349 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2350 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2351 0, &nh6) != 0) 2352 return (0); 2353 2354 ifp = nh6.nh_ifp; 2355 maxmtu = nh6.nh_mtu; 2356 2357 /* Report additional interface capabilities. */ 2358 if (cap != NULL) { 2359 if (ifp->if_capenable & IFCAP_TSO6 && 2360 ifp->if_hwassist & CSUM_TSO) { 2361 cap->ifcap |= CSUM_TSO; 2362 cap->tsomax = ifp->if_hw_tsomax; 2363 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2364 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2365 } 2366 } 2367 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2368 } 2369 2370 return (maxmtu); 2371 } 2372 #endif /* INET6 */ 2373 2374 /* 2375 * Calculate effective SMSS per RFC5681 definition for a given TCP 2376 * connection at its current state, taking into account SACK and etc. 2377 */ 2378 u_int 2379 tcp_maxseg(const struct tcpcb *tp) 2380 { 2381 u_int optlen; 2382 2383 if (tp->t_flags & TF_NOOPT) 2384 return (tp->t_maxseg); 2385 2386 /* 2387 * Here we have a simplified code from tcp_addoptions(), 2388 * without a proper loop, and having most of paddings hardcoded. 2389 * We might make mistakes with padding here in some edge cases, 2390 * but this is harmless, since result of tcp_maxseg() is used 2391 * only in cwnd and ssthresh estimations. 2392 */ 2393 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2394 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2395 if (tp->t_flags & TF_RCVD_TSTMP) 2396 optlen = TCPOLEN_TSTAMP_APPA; 2397 else 2398 optlen = 0; 2399 #ifdef TCP_SIGNATURE 2400 if (tp->t_flags & TF_SIGNATURE) 2401 optlen += PAD(TCPOLEN_SIGNATURE); 2402 #endif 2403 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2404 optlen += TCPOLEN_SACKHDR; 2405 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2406 optlen = PAD(optlen); 2407 } 2408 } else { 2409 if (tp->t_flags & TF_REQ_TSTMP) 2410 optlen = TCPOLEN_TSTAMP_APPA; 2411 else 2412 optlen = PAD(TCPOLEN_MAXSEG); 2413 if (tp->t_flags & TF_REQ_SCALE) 2414 optlen += PAD(TCPOLEN_WINDOW); 2415 #ifdef TCP_SIGNATURE 2416 if (tp->t_flags & TF_SIGNATURE) 2417 optlen += PAD(TCPOLEN_SIGNATURE); 2418 #endif 2419 if (tp->t_flags & TF_SACK_PERMIT) 2420 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2421 } 2422 #undef PAD 2423 optlen = min(optlen, TCP_MAXOLEN); 2424 return (tp->t_maxseg - optlen); 2425 } 2426 2427 #ifdef IPSEC 2428 /* compute ESP/AH header size for TCP, including outer IP header. */ 2429 size_t 2430 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2431 { 2432 struct inpcb *inp; 2433 struct mbuf *m; 2434 size_t hdrsiz; 2435 struct ip *ip; 2436 #ifdef INET6 2437 struct ip6_hdr *ip6; 2438 #endif 2439 struct tcphdr *th; 2440 2441 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2442 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2443 return (0); 2444 m = m_gethdr(M_NOWAIT, MT_DATA); 2445 if (!m) 2446 return (0); 2447 2448 #ifdef INET6 2449 if ((inp->inp_vflag & INP_IPV6) != 0) { 2450 ip6 = mtod(m, struct ip6_hdr *); 2451 th = (struct tcphdr *)(ip6 + 1); 2452 m->m_pkthdr.len = m->m_len = 2453 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2454 tcpip_fillheaders(inp, ip6, th); 2455 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2456 } else 2457 #endif /* INET6 */ 2458 { 2459 ip = mtod(m, struct ip *); 2460 th = (struct tcphdr *)(ip + 1); 2461 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2462 tcpip_fillheaders(inp, ip, th); 2463 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2464 } 2465 2466 m_free(m); 2467 return (hdrsiz); 2468 } 2469 #endif /* IPSEC */ 2470 2471 #ifdef TCP_SIGNATURE 2472 /* 2473 * Callback function invoked by m_apply() to digest TCP segment data 2474 * contained within an mbuf chain. 2475 */ 2476 static int 2477 tcp_signature_apply(void *fstate, void *data, u_int len) 2478 { 2479 2480 MD5Update(fstate, (u_char *)data, len); 2481 return (0); 2482 } 2483 2484 /* 2485 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2486 * search with the destination IP address, and a 'magic SPI' to be 2487 * determined by the application. This is hardcoded elsewhere to 1179 2488 */ 2489 struct secasvar * 2490 tcp_get_sav(struct mbuf *m, u_int direction) 2491 { 2492 union sockaddr_union dst; 2493 struct secasvar *sav; 2494 struct ip *ip; 2495 #ifdef INET6 2496 struct ip6_hdr *ip6; 2497 char ip6buf[INET6_ADDRSTRLEN]; 2498 #endif 2499 2500 /* Extract the destination from the IP header in the mbuf. */ 2501 bzero(&dst, sizeof(union sockaddr_union)); 2502 ip = mtod(m, struct ip *); 2503 #ifdef INET6 2504 ip6 = NULL; /* Make the compiler happy. */ 2505 #endif 2506 switch (ip->ip_v) { 2507 #ifdef INET 2508 case IPVERSION: 2509 dst.sa.sa_len = sizeof(struct sockaddr_in); 2510 dst.sa.sa_family = AF_INET; 2511 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2512 ip->ip_src : ip->ip_dst; 2513 break; 2514 #endif 2515 #ifdef INET6 2516 case (IPV6_VERSION >> 4): 2517 ip6 = mtod(m, struct ip6_hdr *); 2518 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2519 dst.sa.sa_family = AF_INET6; 2520 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2521 ip6->ip6_src : ip6->ip6_dst; 2522 break; 2523 #endif 2524 default: 2525 return (NULL); 2526 /* NOTREACHED */ 2527 break; 2528 } 2529 2530 /* Look up an SADB entry which matches the address of the peer. */ 2531 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2532 if (sav == NULL) { 2533 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2534 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2535 #ifdef INET6 2536 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2537 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2538 #endif 2539 "(unsupported)")); 2540 } 2541 2542 return (sav); 2543 } 2544 2545 /* 2546 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2547 * 2548 * Parameters: 2549 * m pointer to head of mbuf chain 2550 * len length of TCP segment data, excluding options 2551 * optlen length of TCP segment options 2552 * buf pointer to storage for computed MD5 digest 2553 * sav pointer to security assosiation 2554 * 2555 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2556 * When called from tcp_input(), we can be sure that th_sum has been 2557 * zeroed out and verified already. 2558 * 2559 * Releases reference to SADB key before return. 2560 * 2561 * Return 0 if successful, otherwise return -1. 2562 * 2563 */ 2564 int 2565 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2566 u_char *buf, struct secasvar *sav) 2567 { 2568 #ifdef INET 2569 struct ippseudo ippseudo; 2570 #endif 2571 MD5_CTX ctx; 2572 int doff; 2573 struct ip *ip; 2574 #ifdef INET 2575 struct ipovly *ipovly; 2576 #endif 2577 struct tcphdr *th; 2578 #ifdef INET6 2579 struct ip6_hdr *ip6; 2580 struct in6_addr in6; 2581 uint32_t plen; 2582 uint16_t nhdr; 2583 #endif 2584 u_short savecsum; 2585 2586 KASSERT(m != NULL, ("NULL mbuf chain")); 2587 KASSERT(buf != NULL, ("NULL signature pointer")); 2588 2589 /* Extract the destination from the IP header in the mbuf. */ 2590 ip = mtod(m, struct ip *); 2591 #ifdef INET6 2592 ip6 = NULL; /* Make the compiler happy. */ 2593 #endif 2594 2595 MD5Init(&ctx); 2596 /* 2597 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2598 * 2599 * XXX The ippseudo header MUST be digested in network byte order, 2600 * or else we'll fail the regression test. Assume all fields we've 2601 * been doing arithmetic on have been in host byte order. 2602 * XXX One cannot depend on ipovly->ih_len here. When called from 2603 * tcp_output(), the underlying ip_len member has not yet been set. 2604 */ 2605 switch (ip->ip_v) { 2606 #ifdef INET 2607 case IPVERSION: 2608 ipovly = (struct ipovly *)ip; 2609 ippseudo.ippseudo_src = ipovly->ih_src; 2610 ippseudo.ippseudo_dst = ipovly->ih_dst; 2611 ippseudo.ippseudo_pad = 0; 2612 ippseudo.ippseudo_p = IPPROTO_TCP; 2613 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2614 optlen); 2615 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2616 2617 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2618 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2619 break; 2620 #endif 2621 #ifdef INET6 2622 /* 2623 * RFC 2385, 2.0 Proposal 2624 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2625 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2626 * extended next header value (to form 32 bits), and 32-bit segment 2627 * length. 2628 * Note: Upper-Layer Packet Length comes before Next Header. 2629 */ 2630 case (IPV6_VERSION >> 4): 2631 in6 = ip6->ip6_src; 2632 in6_clearscope(&in6); 2633 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2634 in6 = ip6->ip6_dst; 2635 in6_clearscope(&in6); 2636 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2637 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2638 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2639 nhdr = 0; 2640 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2641 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2642 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2643 nhdr = IPPROTO_TCP; 2644 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2645 2646 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2647 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2648 break; 2649 #endif 2650 default: 2651 KEY_FREESAV(&sav); 2652 return (-1); 2653 /* NOTREACHED */ 2654 break; 2655 } 2656 2657 2658 /* 2659 * Step 2: Update MD5 hash with TCP header, excluding options. 2660 * The TCP checksum must be set to zero. 2661 */ 2662 savecsum = th->th_sum; 2663 th->th_sum = 0; 2664 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2665 th->th_sum = savecsum; 2666 2667 /* 2668 * Step 3: Update MD5 hash with TCP segment data. 2669 * Use m_apply() to avoid an early m_pullup(). 2670 */ 2671 if (len > 0) 2672 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2673 2674 /* 2675 * Step 4: Update MD5 hash with shared secret. 2676 */ 2677 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2678 MD5Final(buf, &ctx); 2679 2680 key_sa_recordxfer(sav, m); 2681 KEY_FREESAV(&sav); 2682 return (0); 2683 } 2684 2685 /* 2686 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2687 * 2688 * Return 0 if successful, otherwise return -1. 2689 */ 2690 int 2691 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2692 u_char *buf, u_int direction) 2693 { 2694 struct secasvar *sav; 2695 2696 if ((sav = tcp_get_sav(m, direction)) == NULL) 2697 return (-1); 2698 2699 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2700 } 2701 2702 /* 2703 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2704 * 2705 * Parameters: 2706 * m pointer to head of mbuf chain 2707 * len length of TCP segment data, excluding options 2708 * optlen length of TCP segment options 2709 * buf pointer to storage for computed MD5 digest 2710 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2711 * 2712 * Return 1 if successful, otherwise return 0. 2713 */ 2714 int 2715 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2716 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2717 { 2718 char tmpdigest[TCP_SIGLEN]; 2719 2720 if (tcp_sig_checksigs == 0) 2721 return (1); 2722 if ((tcpbflag & TF_SIGNATURE) == 0) { 2723 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2724 2725 /* 2726 * If this socket is not expecting signature but 2727 * the segment contains signature just fail. 2728 */ 2729 TCPSTAT_INC(tcps_sig_err_sigopt); 2730 TCPSTAT_INC(tcps_sig_rcvbadsig); 2731 return (0); 2732 } 2733 2734 /* Signature is not expected, and not present in segment. */ 2735 return (1); 2736 } 2737 2738 /* 2739 * If this socket is expecting signature but the segment does not 2740 * contain any just fail. 2741 */ 2742 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2743 TCPSTAT_INC(tcps_sig_err_nosigopt); 2744 TCPSTAT_INC(tcps_sig_rcvbadsig); 2745 return (0); 2746 } 2747 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2748 IPSEC_DIR_INBOUND) == -1) { 2749 TCPSTAT_INC(tcps_sig_err_buildsig); 2750 TCPSTAT_INC(tcps_sig_rcvbadsig); 2751 return (0); 2752 } 2753 2754 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2755 TCPSTAT_INC(tcps_sig_rcvbadsig); 2756 return (0); 2757 } 2758 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2759 return (1); 2760 } 2761 #endif /* TCP_SIGNATURE */ 2762 2763 static int 2764 sysctl_drop(SYSCTL_HANDLER_ARGS) 2765 { 2766 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2767 struct sockaddr_storage addrs[2]; 2768 struct inpcb *inp; 2769 struct tcpcb *tp; 2770 struct tcptw *tw; 2771 struct sockaddr_in *fin, *lin; 2772 #ifdef INET6 2773 struct sockaddr_in6 *fin6, *lin6; 2774 #endif 2775 int error; 2776 2777 inp = NULL; 2778 fin = lin = NULL; 2779 #ifdef INET6 2780 fin6 = lin6 = NULL; 2781 #endif 2782 error = 0; 2783 2784 if (req->oldptr != NULL || req->oldlen != 0) 2785 return (EINVAL); 2786 if (req->newptr == NULL) 2787 return (EPERM); 2788 if (req->newlen < sizeof(addrs)) 2789 return (ENOMEM); 2790 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2791 if (error) 2792 return (error); 2793 2794 switch (addrs[0].ss_family) { 2795 #ifdef INET6 2796 case AF_INET6: 2797 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2798 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2799 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2800 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2801 return (EINVAL); 2802 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2803 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2804 return (EINVAL); 2805 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2806 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2807 fin = (struct sockaddr_in *)&addrs[0]; 2808 lin = (struct sockaddr_in *)&addrs[1]; 2809 break; 2810 } 2811 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2812 if (error) 2813 return (error); 2814 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2815 if (error) 2816 return (error); 2817 break; 2818 #endif 2819 #ifdef INET 2820 case AF_INET: 2821 fin = (struct sockaddr_in *)&addrs[0]; 2822 lin = (struct sockaddr_in *)&addrs[1]; 2823 if (fin->sin_len != sizeof(struct sockaddr_in) || 2824 lin->sin_len != sizeof(struct sockaddr_in)) 2825 return (EINVAL); 2826 break; 2827 #endif 2828 default: 2829 return (EINVAL); 2830 } 2831 INP_INFO_RLOCK(&V_tcbinfo); 2832 switch (addrs[0].ss_family) { 2833 #ifdef INET6 2834 case AF_INET6: 2835 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2836 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2837 INPLOOKUP_WLOCKPCB, NULL); 2838 break; 2839 #endif 2840 #ifdef INET 2841 case AF_INET: 2842 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2843 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2844 break; 2845 #endif 2846 } 2847 if (inp != NULL) { 2848 if (inp->inp_flags & INP_TIMEWAIT) { 2849 /* 2850 * XXXRW: There currently exists a state where an 2851 * inpcb is present, but its timewait state has been 2852 * discarded. For now, don't allow dropping of this 2853 * type of inpcb. 2854 */ 2855 tw = intotw(inp); 2856 if (tw != NULL) 2857 tcp_twclose(tw, 0); 2858 else 2859 INP_WUNLOCK(inp); 2860 } else if (!(inp->inp_flags & INP_DROPPED) && 2861 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2862 tp = intotcpcb(inp); 2863 tp = tcp_drop(tp, ECONNABORTED); 2864 if (tp != NULL) 2865 INP_WUNLOCK(inp); 2866 } else 2867 INP_WUNLOCK(inp); 2868 } else 2869 error = ESRCH; 2870 INP_INFO_RUNLOCK(&V_tcbinfo); 2871 return (error); 2872 } 2873 2874 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2875 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2876 0, sysctl_drop, "", "Drop TCP connection"); 2877 2878 /* 2879 * Generate a standardized TCP log line for use throughout the 2880 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2881 * allow use in the interrupt context. 2882 * 2883 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2884 * NB: The function may return NULL if memory allocation failed. 2885 * 2886 * Due to header inclusion and ordering limitations the struct ip 2887 * and ip6_hdr pointers have to be passed as void pointers. 2888 */ 2889 char * 2890 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2891 const void *ip6hdr) 2892 { 2893 2894 /* Is logging enabled? */ 2895 if (tcp_log_in_vain == 0) 2896 return (NULL); 2897 2898 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2899 } 2900 2901 char * 2902 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2903 const void *ip6hdr) 2904 { 2905 2906 /* Is logging enabled? */ 2907 if (tcp_log_debug == 0) 2908 return (NULL); 2909 2910 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2911 } 2912 2913 static char * 2914 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2915 const void *ip6hdr) 2916 { 2917 char *s, *sp; 2918 size_t size; 2919 struct ip *ip; 2920 #ifdef INET6 2921 const struct ip6_hdr *ip6; 2922 2923 ip6 = (const struct ip6_hdr *)ip6hdr; 2924 #endif /* INET6 */ 2925 ip = (struct ip *)ip4hdr; 2926 2927 /* 2928 * The log line looks like this: 2929 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2930 */ 2931 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2932 sizeof(PRINT_TH_FLAGS) + 1 + 2933 #ifdef INET6 2934 2 * INET6_ADDRSTRLEN; 2935 #else 2936 2 * INET_ADDRSTRLEN; 2937 #endif /* INET6 */ 2938 2939 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2940 if (s == NULL) 2941 return (NULL); 2942 2943 strcat(s, "TCP: ["); 2944 sp = s + strlen(s); 2945 2946 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2947 inet_ntoa_r(inc->inc_faddr, sp); 2948 sp = s + strlen(s); 2949 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2950 sp = s + strlen(s); 2951 inet_ntoa_r(inc->inc_laddr, sp); 2952 sp = s + strlen(s); 2953 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2954 #ifdef INET6 2955 } else if (inc) { 2956 ip6_sprintf(sp, &inc->inc6_faddr); 2957 sp = s + strlen(s); 2958 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2959 sp = s + strlen(s); 2960 ip6_sprintf(sp, &inc->inc6_laddr); 2961 sp = s + strlen(s); 2962 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2963 } else if (ip6 && th) { 2964 ip6_sprintf(sp, &ip6->ip6_src); 2965 sp = s + strlen(s); 2966 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2967 sp = s + strlen(s); 2968 ip6_sprintf(sp, &ip6->ip6_dst); 2969 sp = s + strlen(s); 2970 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2971 #endif /* INET6 */ 2972 #ifdef INET 2973 } else if (ip && th) { 2974 inet_ntoa_r(ip->ip_src, sp); 2975 sp = s + strlen(s); 2976 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2977 sp = s + strlen(s); 2978 inet_ntoa_r(ip->ip_dst, sp); 2979 sp = s + strlen(s); 2980 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2981 #endif /* INET */ 2982 } else { 2983 free(s, M_TCPLOG); 2984 return (NULL); 2985 } 2986 sp = s + strlen(s); 2987 if (th) 2988 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2989 if (*(s + size - 1) != '\0') 2990 panic("%s: string too long", __func__); 2991 return (s); 2992 } 2993 2994 /* 2995 * A subroutine which makes it easy to track TCP state changes with DTrace. 2996 * This function shouldn't be called for t_state initializations that don't 2997 * correspond to actual TCP state transitions. 2998 */ 2999 void 3000 tcp_state_change(struct tcpcb *tp, int newstate) 3001 { 3002 #if defined(KDTRACE_HOOKS) 3003 int pstate = tp->t_state; 3004 #endif 3005 3006 TCPSTATES_DEC(tp->t_state); 3007 TCPSTATES_INC(newstate); 3008 tp->t_state = newstate; 3009 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3010 } 3011