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/hhook.h> 45 #include <sys/kernel.h> 46 #include <sys/khelp.h> 47 #include <sys/sysctl.h> 48 #include <sys/jail.h> 49 #include <sys/malloc.h> 50 #include <sys/refcount.h> 51 #include <sys/mbuf.h> 52 #ifdef INET6 53 #include <sys/domain.h> 54 #endif 55 #include <sys/priv.h> 56 #include <sys/proc.h> 57 #include <sys/sdt.h> 58 #include <sys/socket.h> 59 #include <sys/socketvar.h> 60 #include <sys/protosw.h> 61 #include <sys/random.h> 62 63 #include <vm/uma.h> 64 65 #include <net/route.h> 66 #include <net/if.h> 67 #include <net/if_var.h> 68 #include <net/vnet.h> 69 70 #include <netinet/cc.h> 71 #include <netinet/in.h> 72 #include <netinet/in_kdtrace.h> 73 #include <netinet/in_pcb.h> 74 #include <netinet/in_systm.h> 75 #include <netinet/in_var.h> 76 #include <netinet/ip.h> 77 #include <netinet/ip_icmp.h> 78 #include <netinet/ip_var.h> 79 #ifdef INET6 80 #include <netinet/ip6.h> 81 #include <netinet6/in6_pcb.h> 82 #include <netinet6/ip6_var.h> 83 #include <netinet6/scope6_var.h> 84 #include <netinet6/nd6.h> 85 #endif 86 87 #include <netinet/tcp_fsm.h> 88 #include <netinet/tcp_seq.h> 89 #include <netinet/tcp_timer.h> 90 #include <netinet/tcp_var.h> 91 #include <netinet/tcp_syncache.h> 92 #ifdef INET6 93 #include <netinet6/tcp6_var.h> 94 #endif 95 #include <netinet/tcpip.h> 96 #ifdef TCPPCAP 97 #include <netinet/tcp_pcap.h> 98 #endif 99 #ifdef TCPDEBUG 100 #include <netinet/tcp_debug.h> 101 #endif 102 #ifdef INET6 103 #include <netinet6/ip6protosw.h> 104 #endif 105 #ifdef TCP_OFFLOAD 106 #include <netinet/tcp_offload.h> 107 #endif 108 109 #ifdef IPSEC 110 #include <netipsec/ipsec.h> 111 #include <netipsec/xform.h> 112 #ifdef INET6 113 #include <netipsec/ipsec6.h> 114 #endif 115 #include <netipsec/key.h> 116 #include <sys/syslog.h> 117 #endif /*IPSEC*/ 118 119 #include <machine/in_cksum.h> 120 #include <sys/md5.h> 121 122 #include <security/mac/mac_framework.h> 123 124 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 125 #ifdef INET6 126 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 127 #endif 128 129 struct rwlock tcp_function_lock; 130 131 static int 132 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 133 { 134 int error, new; 135 136 new = V_tcp_mssdflt; 137 error = sysctl_handle_int(oidp, &new, 0, req); 138 if (error == 0 && req->newptr) { 139 if (new < TCP_MINMSS) 140 error = EINVAL; 141 else 142 V_tcp_mssdflt = new; 143 } 144 return (error); 145 } 146 147 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 148 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 149 &sysctl_net_inet_tcp_mss_check, "I", 150 "Default TCP Maximum Segment Size"); 151 152 #ifdef INET6 153 static int 154 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 155 { 156 int error, new; 157 158 new = V_tcp_v6mssdflt; 159 error = sysctl_handle_int(oidp, &new, 0, req); 160 if (error == 0 && req->newptr) { 161 if (new < TCP_MINMSS) 162 error = EINVAL; 163 else 164 V_tcp_v6mssdflt = new; 165 } 166 return (error); 167 } 168 169 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 170 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 171 &sysctl_net_inet_tcp_mss_v6_check, "I", 172 "Default TCP Maximum Segment Size for IPv6"); 173 #endif /* INET6 */ 174 175 /* 176 * Minimum MSS we accept and use. This prevents DoS attacks where 177 * we are forced to a ridiculous low MSS like 20 and send hundreds 178 * of packets instead of one. The effect scales with the available 179 * bandwidth and quickly saturates the CPU and network interface 180 * with packet generation and sending. Set to zero to disable MINMSS 181 * checking. This setting prevents us from sending too small packets. 182 */ 183 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 184 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 185 &VNET_NAME(tcp_minmss), 0, 186 "Minimum TCP Maximum Segment Size"); 187 188 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 189 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 190 &VNET_NAME(tcp_do_rfc1323), 0, 191 "Enable rfc1323 (high performance TCP) extensions"); 192 193 static int tcp_log_debug = 0; 194 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 195 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 196 197 static int tcp_tcbhashsize; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 199 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 200 201 static int do_tcpdrain = 1; 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 203 "Enable tcp_drain routine for extra help when low on mbufs"); 204 205 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 206 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 207 208 static VNET_DEFINE(int, icmp_may_rst) = 1; 209 #define V_icmp_may_rst VNET(icmp_may_rst) 210 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 211 &VNET_NAME(icmp_may_rst), 0, 212 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 213 214 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 215 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 216 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 217 &VNET_NAME(tcp_isn_reseed_interval), 0, 218 "Seconds between reseeding of ISN secret"); 219 220 static int tcp_soreceive_stream; 221 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 222 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 223 224 #ifdef TCP_SIGNATURE 225 static int tcp_sig_checksigs = 1; 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 227 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 228 #endif 229 230 VNET_DEFINE(uma_zone_t, sack_hole_zone); 231 #define V_sack_hole_zone VNET(sack_hole_zone) 232 233 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 234 235 static struct inpcb *tcp_notify(struct inpcb *, int); 236 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 237 static void tcp_mtudisc(struct inpcb *, int); 238 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 239 void *ip4hdr, const void *ip6hdr); 240 static void tcp_timer_discard(struct tcpcb *, uint32_t); 241 242 243 static struct tcp_function_block tcp_def_funcblk = { 244 "default", 245 tcp_output, 246 tcp_do_segment, 247 tcp_default_ctloutput, 248 NULL, 249 NULL, 250 NULL, 251 NULL, 252 NULL, 253 NULL, 254 NULL, 255 0, 256 0 257 }; 258 259 struct tcp_funchead t_functions; 260 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 261 262 static struct tcp_function_block * 263 find_tcp_functions_locked(struct tcp_function_set *fs) 264 { 265 struct tcp_function *f; 266 struct tcp_function_block *blk=NULL; 267 268 TAILQ_FOREACH(f, &t_functions, tf_next) { 269 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 270 blk = f->tf_fb; 271 break; 272 } 273 } 274 return(blk); 275 } 276 277 static struct tcp_function_block * 278 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 279 { 280 struct tcp_function_block *rblk=NULL; 281 struct tcp_function *f; 282 283 TAILQ_FOREACH(f, &t_functions, tf_next) { 284 if (f->tf_fb == blk) { 285 rblk = blk; 286 if (s) { 287 *s = f; 288 } 289 break; 290 } 291 } 292 return (rblk); 293 } 294 295 struct tcp_function_block * 296 find_and_ref_tcp_functions(struct tcp_function_set *fs) 297 { 298 struct tcp_function_block *blk; 299 300 rw_rlock(&tcp_function_lock); 301 blk = find_tcp_functions_locked(fs); 302 if (blk) 303 refcount_acquire(&blk->tfb_refcnt); 304 rw_runlock(&tcp_function_lock); 305 return(blk); 306 } 307 308 struct tcp_function_block * 309 find_and_ref_tcp_fb(struct tcp_function_block *blk) 310 { 311 struct tcp_function_block *rblk; 312 313 rw_rlock(&tcp_function_lock); 314 rblk = find_tcp_fb_locked(blk, NULL); 315 if (rblk) 316 refcount_acquire(&rblk->tfb_refcnt); 317 rw_runlock(&tcp_function_lock); 318 return(rblk); 319 } 320 321 322 static int 323 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 324 { 325 int error=ENOENT; 326 struct tcp_function_set fs; 327 struct tcp_function_block *blk; 328 329 memset(&fs, 0, sizeof(fs)); 330 rw_rlock(&tcp_function_lock); 331 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 332 if (blk) { 333 /* Found him */ 334 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 335 fs.pcbcnt = blk->tfb_refcnt; 336 } 337 rw_runlock(&tcp_function_lock); 338 error = sysctl_handle_string(oidp, fs.function_set_name, 339 sizeof(fs.function_set_name), req); 340 341 /* Check for error or no change */ 342 if (error != 0 || req->newptr == NULL) 343 return(error); 344 345 rw_wlock(&tcp_function_lock); 346 blk = find_tcp_functions_locked(&fs); 347 if ((blk == NULL) || 348 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 349 error = ENOENT; 350 goto done; 351 } 352 tcp_func_set_ptr = blk; 353 done: 354 rw_wunlock(&tcp_function_lock); 355 return (error); 356 } 357 358 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 359 CTLTYPE_STRING | CTLFLAG_RW, 360 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 361 "Set/get the default TCP functions"); 362 363 static int 364 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 365 { 366 int error, cnt, linesz; 367 struct tcp_function *f; 368 char *buffer, *cp; 369 size_t bufsz, outsz; 370 371 cnt = 0; 372 rw_rlock(&tcp_function_lock); 373 TAILQ_FOREACH(f, &t_functions, tf_next) { 374 cnt++; 375 } 376 rw_runlock(&tcp_function_lock); 377 378 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 379 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 380 381 error = 0; 382 cp = buffer; 383 384 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 385 cp += linesz; 386 bufsz -= linesz; 387 outsz = linesz; 388 389 rw_rlock(&tcp_function_lock); 390 TAILQ_FOREACH(f, &t_functions, tf_next) { 391 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 392 f->tf_fb->tfb_tcp_block_name, 393 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 394 f->tf_fb->tfb_refcnt); 395 if (linesz >= bufsz) { 396 error = EOVERFLOW; 397 break; 398 } 399 cp += linesz; 400 bufsz -= linesz; 401 outsz += linesz; 402 } 403 rw_runlock(&tcp_function_lock); 404 if (error == 0) 405 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 406 free(buffer, M_TEMP); 407 return (error); 408 } 409 410 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 411 CTLTYPE_STRING|CTLFLAG_RD, 412 NULL, 0, sysctl_net_inet_list_available, "A", 413 "list available TCP Function sets"); 414 415 /* 416 * Target size of TCP PCB hash tables. Must be a power of two. 417 * 418 * Note that this can be overridden by the kernel environment 419 * variable net.inet.tcp.tcbhashsize 420 */ 421 #ifndef TCBHASHSIZE 422 #define TCBHASHSIZE 0 423 #endif 424 425 /* 426 * XXX 427 * Callouts should be moved into struct tcp directly. They are currently 428 * separate because the tcpcb structure is exported to userland for sysctl 429 * parsing purposes, which do not know about callouts. 430 */ 431 struct tcpcb_mem { 432 struct tcpcb tcb; 433 struct tcp_timer tt; 434 struct cc_var ccv; 435 struct osd osd; 436 }; 437 438 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 439 #define V_tcpcb_zone VNET(tcpcb_zone) 440 441 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 442 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 443 444 static struct mtx isn_mtx; 445 446 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 447 #define ISN_LOCK() mtx_lock(&isn_mtx) 448 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 449 450 /* 451 * TCP initialization. 452 */ 453 static void 454 tcp_zone_change(void *tag) 455 { 456 457 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 458 uma_zone_set_max(V_tcpcb_zone, maxsockets); 459 tcp_tw_zone_change(); 460 } 461 462 static int 463 tcp_inpcb_init(void *mem, int size, int flags) 464 { 465 struct inpcb *inp = mem; 466 467 INP_LOCK_INIT(inp, "inp", "tcpinp"); 468 return (0); 469 } 470 471 /* 472 * Take a value and get the next power of 2 that doesn't overflow. 473 * Used to size the tcp_inpcb hash buckets. 474 */ 475 static int 476 maketcp_hashsize(int size) 477 { 478 int hashsize; 479 480 /* 481 * auto tune. 482 * get the next power of 2 higher than maxsockets. 483 */ 484 hashsize = 1 << fls(size); 485 /* catch overflow, and just go one power of 2 smaller */ 486 if (hashsize < size) { 487 hashsize = 1 << (fls(size) - 1); 488 } 489 return (hashsize); 490 } 491 492 int 493 register_tcp_functions(struct tcp_function_block *blk, int wait) 494 { 495 struct tcp_function_block *lblk; 496 struct tcp_function *n; 497 struct tcp_function_set fs; 498 499 if ((blk->tfb_tcp_output == NULL) || 500 (blk->tfb_tcp_do_segment == NULL) || 501 (blk->tfb_tcp_ctloutput == NULL) || 502 (strlen(blk->tfb_tcp_block_name) == 0)) { 503 /* 504 * These functions are required and you 505 * need a name. 506 */ 507 return (EINVAL); 508 } 509 if (blk->tfb_tcp_timer_stop_all || 510 blk->tfb_tcp_timers_left || 511 blk->tfb_tcp_timer_activate || 512 blk->tfb_tcp_timer_active || 513 blk->tfb_tcp_timer_stop) { 514 /* 515 * If you define one timer function you 516 * must have them all. 517 */ 518 if ((blk->tfb_tcp_timer_stop_all == NULL) || 519 (blk->tfb_tcp_timers_left == NULL) || 520 (blk->tfb_tcp_timer_activate == NULL) || 521 (blk->tfb_tcp_timer_active == NULL) || 522 (blk->tfb_tcp_timer_stop == NULL)) { 523 return (EINVAL); 524 } 525 } 526 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 527 if (n == NULL) { 528 return (ENOMEM); 529 } 530 n->tf_fb = blk; 531 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 532 rw_wlock(&tcp_function_lock); 533 lblk = find_tcp_functions_locked(&fs); 534 if (lblk) { 535 /* Duplicate name space not allowed */ 536 rw_wunlock(&tcp_function_lock); 537 free(n, M_TCPFUNCTIONS); 538 return (EALREADY); 539 } 540 refcount_init(&blk->tfb_refcnt, 0); 541 blk->tfb_flags = 0; 542 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 543 rw_wunlock(&tcp_function_lock); 544 return(0); 545 } 546 547 int 548 deregister_tcp_functions(struct tcp_function_block *blk) 549 { 550 struct tcp_function_block *lblk; 551 struct tcp_function *f; 552 int error=ENOENT; 553 554 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 555 /* You can't un-register the default */ 556 return (EPERM); 557 } 558 rw_wlock(&tcp_function_lock); 559 if (blk == tcp_func_set_ptr) { 560 /* You can't free the current default */ 561 rw_wunlock(&tcp_function_lock); 562 return (EBUSY); 563 } 564 if (blk->tfb_refcnt) { 565 /* Still tcb attached, mark it. */ 566 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 567 rw_wunlock(&tcp_function_lock); 568 return (EBUSY); 569 } 570 lblk = find_tcp_fb_locked(blk, &f); 571 if (lblk) { 572 /* Found */ 573 TAILQ_REMOVE(&t_functions, f, tf_next); 574 f->tf_fb = NULL; 575 free(f, M_TCPFUNCTIONS); 576 error = 0; 577 } 578 rw_wunlock(&tcp_function_lock); 579 return (error); 580 } 581 582 void 583 tcp_init(void) 584 { 585 const char *tcbhash_tuneable; 586 int hashsize; 587 588 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 589 590 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 591 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 592 printf("%s: WARNING: unable to register helper hook\n", __func__); 593 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 594 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 595 printf("%s: WARNING: unable to register helper hook\n", __func__); 596 /* Setup the tcp function block list */ 597 TAILQ_INIT(&t_functions); 598 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 599 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 600 hashsize = TCBHASHSIZE; 601 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 602 if (hashsize == 0) { 603 /* 604 * Auto tune the hash size based on maxsockets. 605 * A perfect hash would have a 1:1 mapping 606 * (hashsize = maxsockets) however it's been 607 * suggested that O(2) average is better. 608 */ 609 hashsize = maketcp_hashsize(maxsockets / 4); 610 /* 611 * Our historical default is 512, 612 * do not autotune lower than this. 613 */ 614 if (hashsize < 512) 615 hashsize = 512; 616 if (bootverbose) 617 printf("%s: %s auto tuned to %d\n", __func__, 618 tcbhash_tuneable, hashsize); 619 } 620 /* 621 * We require a hashsize to be a power of two. 622 * Previously if it was not a power of two we would just reset it 623 * back to 512, which could be a nasty surprise if you did not notice 624 * the error message. 625 * Instead what we do is clip it to the closest power of two lower 626 * than the specified hash value. 627 */ 628 if (!powerof2(hashsize)) { 629 int oldhashsize = hashsize; 630 631 hashsize = maketcp_hashsize(hashsize); 632 /* prevent absurdly low value */ 633 if (hashsize < 16) 634 hashsize = 16; 635 printf("%s: WARNING: TCB hash size not a power of 2, " 636 "clipped from %d to %d.\n", __func__, oldhashsize, 637 hashsize); 638 } 639 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 640 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 641 IPI_HASHFIELDS_4TUPLE); 642 643 /* 644 * These have to be type stable for the benefit of the timers. 645 */ 646 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 647 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 648 uma_zone_set_max(V_tcpcb_zone, maxsockets); 649 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 650 651 tcp_tw_init(); 652 syncache_init(); 653 tcp_hc_init(); 654 655 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 656 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 657 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 658 659 /* Skip initialization of globals for non-default instances. */ 660 if (!IS_DEFAULT_VNET(curvnet)) 661 return; 662 663 tcp_reass_global_init(); 664 665 /* XXX virtualize those bellow? */ 666 tcp_delacktime = TCPTV_DELACK; 667 tcp_keepinit = TCPTV_KEEP_INIT; 668 tcp_keepidle = TCPTV_KEEP_IDLE; 669 tcp_keepintvl = TCPTV_KEEPINTVL; 670 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 671 tcp_msl = TCPTV_MSL; 672 tcp_rexmit_min = TCPTV_MIN; 673 if (tcp_rexmit_min < 1) 674 tcp_rexmit_min = 1; 675 tcp_rexmit_slop = TCPTV_CPU_VAR; 676 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 677 tcp_tcbhashsize = hashsize; 678 679 if (tcp_soreceive_stream) { 680 #ifdef INET 681 tcp_usrreqs.pru_soreceive = soreceive_stream; 682 #endif 683 #ifdef INET6 684 tcp6_usrreqs.pru_soreceive = soreceive_stream; 685 #endif /* INET6 */ 686 } 687 688 #ifdef INET6 689 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 690 #else /* INET6 */ 691 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 692 #endif /* INET6 */ 693 if (max_protohdr < TCP_MINPROTOHDR) 694 max_protohdr = TCP_MINPROTOHDR; 695 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 696 panic("tcp_init"); 697 #undef TCP_MINPROTOHDR 698 699 ISN_LOCK_INIT(); 700 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 701 SHUTDOWN_PRI_DEFAULT); 702 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 703 EVENTHANDLER_PRI_ANY); 704 #ifdef TCPPCAP 705 tcp_pcap_init(); 706 #endif 707 } 708 709 #ifdef VIMAGE 710 void 711 tcp_destroy(void) 712 { 713 int error; 714 715 tcp_hc_destroy(); 716 syncache_destroy(); 717 tcp_tw_destroy(); 718 in_pcbinfo_destroy(&V_tcbinfo); 719 uma_zdestroy(V_sack_hole_zone); 720 uma_zdestroy(V_tcpcb_zone); 721 722 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 723 if (error != 0) { 724 printf("%s: WARNING: unable to deregister helper hook " 725 "type=%d, id=%d: error %d returned\n", __func__, 726 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 727 } 728 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 729 if (error != 0) { 730 printf("%s: WARNING: unable to deregister helper hook " 731 "type=%d, id=%d: error %d returned\n", __func__, 732 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 733 } 734 } 735 #endif 736 737 void 738 tcp_fini(void *xtp) 739 { 740 741 } 742 743 /* 744 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 745 * tcp_template used to store this data in mbufs, but we now recopy it out 746 * of the tcpcb each time to conserve mbufs. 747 */ 748 void 749 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 750 { 751 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 752 753 INP_WLOCK_ASSERT(inp); 754 755 #ifdef INET6 756 if ((inp->inp_vflag & INP_IPV6) != 0) { 757 struct ip6_hdr *ip6; 758 759 ip6 = (struct ip6_hdr *)ip_ptr; 760 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 761 (inp->inp_flow & IPV6_FLOWINFO_MASK); 762 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 763 (IPV6_VERSION & IPV6_VERSION_MASK); 764 ip6->ip6_nxt = IPPROTO_TCP; 765 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 766 ip6->ip6_src = inp->in6p_laddr; 767 ip6->ip6_dst = inp->in6p_faddr; 768 } 769 #endif /* INET6 */ 770 #if defined(INET6) && defined(INET) 771 else 772 #endif 773 #ifdef INET 774 { 775 struct ip *ip; 776 777 ip = (struct ip *)ip_ptr; 778 ip->ip_v = IPVERSION; 779 ip->ip_hl = 5; 780 ip->ip_tos = inp->inp_ip_tos; 781 ip->ip_len = 0; 782 ip->ip_id = 0; 783 ip->ip_off = 0; 784 ip->ip_ttl = inp->inp_ip_ttl; 785 ip->ip_sum = 0; 786 ip->ip_p = IPPROTO_TCP; 787 ip->ip_src = inp->inp_laddr; 788 ip->ip_dst = inp->inp_faddr; 789 } 790 #endif /* INET */ 791 th->th_sport = inp->inp_lport; 792 th->th_dport = inp->inp_fport; 793 th->th_seq = 0; 794 th->th_ack = 0; 795 th->th_x2 = 0; 796 th->th_off = 5; 797 th->th_flags = 0; 798 th->th_win = 0; 799 th->th_urp = 0; 800 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 801 } 802 803 /* 804 * Create template to be used to send tcp packets on a connection. 805 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 806 * use for this function is in keepalives, which use tcp_respond. 807 */ 808 struct tcptemp * 809 tcpip_maketemplate(struct inpcb *inp) 810 { 811 struct tcptemp *t; 812 813 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 814 if (t == NULL) 815 return (NULL); 816 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 817 return (t); 818 } 819 820 /* 821 * Send a single message to the TCP at address specified by 822 * the given TCP/IP header. If m == NULL, then we make a copy 823 * of the tcpiphdr at th and send directly to the addressed host. 824 * This is used to force keep alive messages out using the TCP 825 * template for a connection. If flags are given then we send 826 * a message back to the TCP which originated the segment th, 827 * and discard the mbuf containing it and any other attached mbufs. 828 * 829 * In any case the ack and sequence number of the transmitted 830 * segment are as specified by the parameters. 831 * 832 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 833 */ 834 void 835 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 836 tcp_seq ack, tcp_seq seq, int flags) 837 { 838 int tlen; 839 int win = 0; 840 struct ip *ip; 841 struct tcphdr *nth; 842 #ifdef INET6 843 struct ip6_hdr *ip6; 844 int isipv6; 845 #endif /* INET6 */ 846 int ipflags = 0; 847 struct inpcb *inp; 848 849 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 850 851 #ifdef INET6 852 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 853 ip6 = ipgen; 854 #endif /* INET6 */ 855 ip = ipgen; 856 857 if (tp != NULL) { 858 inp = tp->t_inpcb; 859 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 860 INP_WLOCK_ASSERT(inp); 861 } else 862 inp = NULL; 863 864 if (tp != NULL) { 865 if (!(flags & TH_RST)) { 866 win = sbspace(&inp->inp_socket->so_rcv); 867 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 868 win = (long)TCP_MAXWIN << tp->rcv_scale; 869 } 870 } 871 if (m == NULL) { 872 m = m_gethdr(M_NOWAIT, MT_DATA); 873 if (m == NULL) 874 return; 875 tlen = 0; 876 m->m_data += max_linkhdr; 877 #ifdef INET6 878 if (isipv6) { 879 bcopy((caddr_t)ip6, mtod(m, caddr_t), 880 sizeof(struct ip6_hdr)); 881 ip6 = mtod(m, struct ip6_hdr *); 882 nth = (struct tcphdr *)(ip6 + 1); 883 } else 884 #endif /* INET6 */ 885 { 886 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 887 ip = mtod(m, struct ip *); 888 nth = (struct tcphdr *)(ip + 1); 889 } 890 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 891 flags = TH_ACK; 892 } else { 893 /* 894 * reuse the mbuf. 895 * XXX MRT We inherrit the FIB, which is lucky. 896 */ 897 m_freem(m->m_next); 898 m->m_next = NULL; 899 m->m_data = (caddr_t)ipgen; 900 /* m_len is set later */ 901 tlen = 0; 902 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 903 #ifdef INET6 904 if (isipv6) { 905 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 906 nth = (struct tcphdr *)(ip6 + 1); 907 } else 908 #endif /* INET6 */ 909 { 910 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 911 nth = (struct tcphdr *)(ip + 1); 912 } 913 if (th != nth) { 914 /* 915 * this is usually a case when an extension header 916 * exists between the IPv6 header and the 917 * TCP header. 918 */ 919 nth->th_sport = th->th_sport; 920 nth->th_dport = th->th_dport; 921 } 922 xchg(nth->th_dport, nth->th_sport, uint16_t); 923 #undef xchg 924 } 925 #ifdef INET6 926 if (isipv6) { 927 ip6->ip6_flow = 0; 928 ip6->ip6_vfc = IPV6_VERSION; 929 ip6->ip6_nxt = IPPROTO_TCP; 930 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 931 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 932 } 933 #endif 934 #if defined(INET) && defined(INET6) 935 else 936 #endif 937 #ifdef INET 938 { 939 tlen += sizeof (struct tcpiphdr); 940 ip->ip_len = htons(tlen); 941 ip->ip_ttl = V_ip_defttl; 942 if (V_path_mtu_discovery) 943 ip->ip_off |= htons(IP_DF); 944 } 945 #endif 946 m->m_len = tlen; 947 m->m_pkthdr.len = tlen; 948 m->m_pkthdr.rcvif = NULL; 949 #ifdef MAC 950 if (inp != NULL) { 951 /* 952 * Packet is associated with a socket, so allow the 953 * label of the response to reflect the socket label. 954 */ 955 INP_WLOCK_ASSERT(inp); 956 mac_inpcb_create_mbuf(inp, m); 957 } else { 958 /* 959 * Packet is not associated with a socket, so possibly 960 * update the label in place. 961 */ 962 mac_netinet_tcp_reply(m); 963 } 964 #endif 965 nth->th_seq = htonl(seq); 966 nth->th_ack = htonl(ack); 967 nth->th_x2 = 0; 968 nth->th_off = sizeof (struct tcphdr) >> 2; 969 nth->th_flags = flags; 970 if (tp != NULL) 971 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 972 else 973 nth->th_win = htons((u_short)win); 974 nth->th_urp = 0; 975 976 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 977 #ifdef INET6 978 if (isipv6) { 979 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 980 nth->th_sum = in6_cksum_pseudo(ip6, 981 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 982 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 983 NULL, NULL); 984 } 985 #endif /* INET6 */ 986 #if defined(INET6) && defined(INET) 987 else 988 #endif 989 #ifdef INET 990 { 991 m->m_pkthdr.csum_flags = CSUM_TCP; 992 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 993 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 994 } 995 #endif /* INET */ 996 #ifdef TCPDEBUG 997 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 998 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 999 #endif 1000 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *)); 1001 if (flags & TH_RST) 1002 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1003 tp, nth); 1004 1005 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1006 #ifdef INET6 1007 if (isipv6) 1008 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 1009 #endif /* INET6 */ 1010 #if defined(INET) && defined(INET6) 1011 else 1012 #endif 1013 #ifdef INET 1014 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 1015 #endif 1016 } 1017 1018 /* 1019 * Create a new TCP control block, making an 1020 * empty reassembly queue and hooking it to the argument 1021 * protocol control block. The `inp' parameter must have 1022 * come from the zone allocator set up in tcp_init(). 1023 */ 1024 struct tcpcb * 1025 tcp_newtcpcb(struct inpcb *inp) 1026 { 1027 struct tcpcb_mem *tm; 1028 struct tcpcb *tp; 1029 #ifdef INET6 1030 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1031 #endif /* INET6 */ 1032 1033 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1034 if (tm == NULL) 1035 return (NULL); 1036 tp = &tm->tcb; 1037 1038 /* Initialise cc_var struct for this tcpcb. */ 1039 tp->ccv = &tm->ccv; 1040 tp->ccv->type = IPPROTO_TCP; 1041 tp->ccv->ccvc.tcp = tp; 1042 rw_rlock(&tcp_function_lock); 1043 tp->t_fb = tcp_func_set_ptr; 1044 refcount_acquire(&tp->t_fb->tfb_refcnt); 1045 rw_runlock(&tcp_function_lock); 1046 if (tp->t_fb->tfb_tcp_fb_init) { 1047 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1048 } 1049 /* 1050 * Use the current system default CC algorithm. 1051 */ 1052 CC_LIST_RLOCK(); 1053 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1054 CC_ALGO(tp) = CC_DEFAULT(); 1055 CC_LIST_RUNLOCK(); 1056 1057 if (CC_ALGO(tp)->cb_init != NULL) 1058 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1059 if (tp->t_fb->tfb_tcp_fb_fini) 1060 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1061 refcount_release(&tp->t_fb->tfb_refcnt); 1062 uma_zfree(V_tcpcb_zone, tm); 1063 return (NULL); 1064 } 1065 1066 tp->osd = &tm->osd; 1067 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1068 if (tp->t_fb->tfb_tcp_fb_fini) 1069 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1070 refcount_release(&tp->t_fb->tfb_refcnt); 1071 uma_zfree(V_tcpcb_zone, tm); 1072 return (NULL); 1073 } 1074 1075 #ifdef VIMAGE 1076 tp->t_vnet = inp->inp_vnet; 1077 #endif 1078 tp->t_timers = &tm->tt; 1079 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1080 tp->t_maxseg = tp->t_maxopd = 1081 #ifdef INET6 1082 isipv6 ? V_tcp_v6mssdflt : 1083 #endif /* INET6 */ 1084 V_tcp_mssdflt; 1085 1086 /* Set up our timeouts. */ 1087 callout_init(&tp->t_timers->tt_rexmt, 1); 1088 callout_init(&tp->t_timers->tt_persist, 1); 1089 callout_init(&tp->t_timers->tt_keep, 1); 1090 callout_init(&tp->t_timers->tt_2msl, 1); 1091 callout_init(&tp->t_timers->tt_delack, 1); 1092 1093 if (V_tcp_do_rfc1323) 1094 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1095 if (V_tcp_do_sack) 1096 tp->t_flags |= TF_SACK_PERMIT; 1097 TAILQ_INIT(&tp->snd_holes); 1098 /* 1099 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1100 * is called. 1101 */ 1102 in_pcbref(inp); /* Reference for tcpcb */ 1103 tp->t_inpcb = inp; 1104 1105 /* 1106 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1107 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1108 * reasonable initial retransmit time. 1109 */ 1110 tp->t_srtt = TCPTV_SRTTBASE; 1111 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1112 tp->t_rttmin = tcp_rexmit_min; 1113 tp->t_rxtcur = TCPTV_RTOBASE; 1114 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1115 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1116 tp->t_rcvtime = ticks; 1117 /* 1118 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1119 * because the socket may be bound to an IPv6 wildcard address, 1120 * which may match an IPv4-mapped IPv6 address. 1121 */ 1122 inp->inp_ip_ttl = V_ip_defttl; 1123 inp->inp_ppcb = tp; 1124 #ifdef TCPPCAP 1125 /* 1126 * Init the TCP PCAP queues. 1127 */ 1128 tcp_pcap_tcpcb_init(tp); 1129 #endif 1130 return (tp); /* XXX */ 1131 } 1132 1133 /* 1134 * Switch the congestion control algorithm back to NewReno for any active 1135 * control blocks using an algorithm which is about to go away. 1136 * This ensures the CC framework can allow the unload to proceed without leaving 1137 * any dangling pointers which would trigger a panic. 1138 * Returning non-zero would inform the CC framework that something went wrong 1139 * and it would be unsafe to allow the unload to proceed. However, there is no 1140 * way for this to occur with this implementation so we always return zero. 1141 */ 1142 int 1143 tcp_ccalgounload(struct cc_algo *unload_algo) 1144 { 1145 struct cc_algo *tmpalgo; 1146 struct inpcb *inp; 1147 struct tcpcb *tp; 1148 VNET_ITERATOR_DECL(vnet_iter); 1149 1150 /* 1151 * Check all active control blocks across all network stacks and change 1152 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1153 * requires cleanup code to be run, call it. 1154 */ 1155 VNET_LIST_RLOCK(); 1156 VNET_FOREACH(vnet_iter) { 1157 CURVNET_SET(vnet_iter); 1158 INP_INFO_WLOCK(&V_tcbinfo); 1159 /* 1160 * New connections already part way through being initialised 1161 * with the CC algo we're removing will not race with this code 1162 * because the INP_INFO_WLOCK is held during initialisation. We 1163 * therefore don't enter the loop below until the connection 1164 * list has stabilised. 1165 */ 1166 LIST_FOREACH(inp, &V_tcb, inp_list) { 1167 INP_WLOCK(inp); 1168 /* Important to skip tcptw structs. */ 1169 if (!(inp->inp_flags & INP_TIMEWAIT) && 1170 (tp = intotcpcb(inp)) != NULL) { 1171 /* 1172 * By holding INP_WLOCK here, we are assured 1173 * that the connection is not currently 1174 * executing inside the CC module's functions 1175 * i.e. it is safe to make the switch back to 1176 * NewReno. 1177 */ 1178 if (CC_ALGO(tp) == unload_algo) { 1179 tmpalgo = CC_ALGO(tp); 1180 /* NewReno does not require any init. */ 1181 CC_ALGO(tp) = &newreno_cc_algo; 1182 if (tmpalgo->cb_destroy != NULL) 1183 tmpalgo->cb_destroy(tp->ccv); 1184 } 1185 } 1186 INP_WUNLOCK(inp); 1187 } 1188 INP_INFO_WUNLOCK(&V_tcbinfo); 1189 CURVNET_RESTORE(); 1190 } 1191 VNET_LIST_RUNLOCK(); 1192 1193 return (0); 1194 } 1195 1196 /* 1197 * Drop a TCP connection, reporting 1198 * the specified error. If connection is synchronized, 1199 * then send a RST to peer. 1200 */ 1201 struct tcpcb * 1202 tcp_drop(struct tcpcb *tp, int errno) 1203 { 1204 struct socket *so = tp->t_inpcb->inp_socket; 1205 1206 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1207 INP_WLOCK_ASSERT(tp->t_inpcb); 1208 1209 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1210 tcp_state_change(tp, TCPS_CLOSED); 1211 (void) tp->t_fb->tfb_tcp_output(tp); 1212 TCPSTAT_INC(tcps_drops); 1213 } else 1214 TCPSTAT_INC(tcps_conndrops); 1215 if (errno == ETIMEDOUT && tp->t_softerror) 1216 errno = tp->t_softerror; 1217 so->so_error = errno; 1218 return (tcp_close(tp)); 1219 } 1220 1221 void 1222 tcp_discardcb(struct tcpcb *tp) 1223 { 1224 struct inpcb *inp = tp->t_inpcb; 1225 struct socket *so = inp->inp_socket; 1226 #ifdef INET6 1227 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1228 #endif /* INET6 */ 1229 int released; 1230 1231 INP_WLOCK_ASSERT(inp); 1232 1233 /* 1234 * Make sure that all of our timers are stopped before we delete the 1235 * PCB. 1236 * 1237 * If stopping a timer fails, we schedule a discard function in same 1238 * callout, and the last discard function called will take care of 1239 * deleting the tcpcb. 1240 */ 1241 tcp_timer_stop(tp, TT_REXMT); 1242 tcp_timer_stop(tp, TT_PERSIST); 1243 tcp_timer_stop(tp, TT_KEEP); 1244 tcp_timer_stop(tp, TT_2MSL); 1245 tcp_timer_stop(tp, TT_DELACK); 1246 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1247 /* Call the stop-all function of the methods */ 1248 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1249 } 1250 1251 /* 1252 * If we got enough samples through the srtt filter, 1253 * save the rtt and rttvar in the routing entry. 1254 * 'Enough' is arbitrarily defined as 4 rtt samples. 1255 * 4 samples is enough for the srtt filter to converge 1256 * to within enough % of the correct value; fewer samples 1257 * and we could save a bogus rtt. The danger is not high 1258 * as tcp quickly recovers from everything. 1259 * XXX: Works very well but needs some more statistics! 1260 */ 1261 if (tp->t_rttupdated >= 4) { 1262 struct hc_metrics_lite metrics; 1263 u_long ssthresh; 1264 1265 bzero(&metrics, sizeof(metrics)); 1266 /* 1267 * Update the ssthresh always when the conditions below 1268 * are satisfied. This gives us better new start value 1269 * for the congestion avoidance for new connections. 1270 * ssthresh is only set if packet loss occured on a session. 1271 * 1272 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1273 * being torn down. Ideally this code would not use 'so'. 1274 */ 1275 ssthresh = tp->snd_ssthresh; 1276 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1277 /* 1278 * convert the limit from user data bytes to 1279 * packets then to packet data bytes. 1280 */ 1281 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1282 if (ssthresh < 2) 1283 ssthresh = 2; 1284 ssthresh *= (u_long)(tp->t_maxseg + 1285 #ifdef INET6 1286 (isipv6 ? sizeof (struct ip6_hdr) + 1287 sizeof (struct tcphdr) : 1288 #endif 1289 sizeof (struct tcpiphdr) 1290 #ifdef INET6 1291 ) 1292 #endif 1293 ); 1294 } else 1295 ssthresh = 0; 1296 metrics.rmx_ssthresh = ssthresh; 1297 1298 metrics.rmx_rtt = tp->t_srtt; 1299 metrics.rmx_rttvar = tp->t_rttvar; 1300 metrics.rmx_cwnd = tp->snd_cwnd; 1301 metrics.rmx_sendpipe = 0; 1302 metrics.rmx_recvpipe = 0; 1303 1304 tcp_hc_update(&inp->inp_inc, &metrics); 1305 } 1306 1307 /* free the reassembly queue, if any */ 1308 tcp_reass_flush(tp); 1309 1310 #ifdef TCP_OFFLOAD 1311 /* Disconnect offload device, if any. */ 1312 if (tp->t_flags & TF_TOE) 1313 tcp_offload_detach(tp); 1314 #endif 1315 1316 tcp_free_sackholes(tp); 1317 1318 #ifdef TCPPCAP 1319 /* Free the TCP PCAP queues. */ 1320 tcp_pcap_drain(&(tp->t_inpkts)); 1321 tcp_pcap_drain(&(tp->t_outpkts)); 1322 #endif 1323 1324 /* Allow the CC algorithm to clean up after itself. */ 1325 if (CC_ALGO(tp)->cb_destroy != NULL) 1326 CC_ALGO(tp)->cb_destroy(tp->ccv); 1327 1328 khelp_destroy_osd(tp->osd); 1329 1330 CC_ALGO(tp) = NULL; 1331 inp->inp_ppcb = NULL; 1332 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1333 /* We own the last reference on tcpcb, let's free it. */ 1334 if ((tp->t_fb->tfb_tcp_timers_left) && 1335 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1336 /* Some fb timers left running! */ 1337 return; 1338 } 1339 if (tp->t_fb->tfb_tcp_fb_fini) 1340 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1341 refcount_release(&tp->t_fb->tfb_refcnt); 1342 tp->t_inpcb = NULL; 1343 uma_zfree(V_tcpcb_zone, tp); 1344 released = in_pcbrele_wlocked(inp); 1345 KASSERT(!released, ("%s: inp %p should not have been released " 1346 "here", __func__, inp)); 1347 } 1348 } 1349 1350 void 1351 tcp_timer_2msl_discard(void *xtp) 1352 { 1353 1354 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1355 } 1356 1357 void 1358 tcp_timer_keep_discard(void *xtp) 1359 { 1360 1361 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1362 } 1363 1364 void 1365 tcp_timer_persist_discard(void *xtp) 1366 { 1367 1368 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1369 } 1370 1371 void 1372 tcp_timer_rexmt_discard(void *xtp) 1373 { 1374 1375 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1376 } 1377 1378 void 1379 tcp_timer_delack_discard(void *xtp) 1380 { 1381 1382 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1383 } 1384 1385 void 1386 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1387 { 1388 struct inpcb *inp; 1389 1390 CURVNET_SET(tp->t_vnet); 1391 INP_INFO_RLOCK(&V_tcbinfo); 1392 inp = tp->t_inpcb; 1393 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1394 __func__, tp)); 1395 INP_WLOCK(inp); 1396 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1397 ("%s: tcpcb has to be stopped here", __func__)); 1398 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1399 ("%s: discard callout should be running", __func__)); 1400 tp->t_timers->tt_flags &= ~timer_type; 1401 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1402 /* We own the last reference on this tcpcb, let's free it. */ 1403 if ((tp->t_fb->tfb_tcp_timers_left) && 1404 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1405 /* Some fb timers left running! */ 1406 goto leave; 1407 } 1408 if (tp->t_fb->tfb_tcp_fb_fini) 1409 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1410 refcount_release(&tp->t_fb->tfb_refcnt); 1411 tp->t_inpcb = NULL; 1412 uma_zfree(V_tcpcb_zone, tp); 1413 if (in_pcbrele_wlocked(inp)) { 1414 INP_INFO_RUNLOCK(&V_tcbinfo); 1415 CURVNET_RESTORE(); 1416 return; 1417 } 1418 } 1419 leave: 1420 INP_WUNLOCK(inp); 1421 INP_INFO_RUNLOCK(&V_tcbinfo); 1422 CURVNET_RESTORE(); 1423 } 1424 1425 /* 1426 * Attempt to close a TCP control block, marking it as dropped, and freeing 1427 * the socket if we hold the only reference. 1428 */ 1429 struct tcpcb * 1430 tcp_close(struct tcpcb *tp) 1431 { 1432 struct inpcb *inp = tp->t_inpcb; 1433 struct socket *so; 1434 1435 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1436 INP_WLOCK_ASSERT(inp); 1437 1438 #ifdef TCP_OFFLOAD 1439 if (tp->t_state == TCPS_LISTEN) 1440 tcp_offload_listen_stop(tp); 1441 #endif 1442 in_pcbdrop(inp); 1443 TCPSTAT_INC(tcps_closed); 1444 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1445 so = inp->inp_socket; 1446 soisdisconnected(so); 1447 if (inp->inp_flags & INP_SOCKREF) { 1448 KASSERT(so->so_state & SS_PROTOREF, 1449 ("tcp_close: !SS_PROTOREF")); 1450 inp->inp_flags &= ~INP_SOCKREF; 1451 INP_WUNLOCK(inp); 1452 ACCEPT_LOCK(); 1453 SOCK_LOCK(so); 1454 so->so_state &= ~SS_PROTOREF; 1455 sofree(so); 1456 return (NULL); 1457 } 1458 return (tp); 1459 } 1460 1461 void 1462 tcp_drain(void) 1463 { 1464 VNET_ITERATOR_DECL(vnet_iter); 1465 1466 if (!do_tcpdrain) 1467 return; 1468 1469 VNET_LIST_RLOCK_NOSLEEP(); 1470 VNET_FOREACH(vnet_iter) { 1471 CURVNET_SET(vnet_iter); 1472 struct inpcb *inpb; 1473 struct tcpcb *tcpb; 1474 1475 /* 1476 * Walk the tcpbs, if existing, and flush the reassembly queue, 1477 * if there is one... 1478 * XXX: The "Net/3" implementation doesn't imply that the TCP 1479 * reassembly queue should be flushed, but in a situation 1480 * where we're really low on mbufs, this is potentially 1481 * useful. 1482 */ 1483 INP_INFO_WLOCK(&V_tcbinfo); 1484 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1485 if (inpb->inp_flags & INP_TIMEWAIT) 1486 continue; 1487 INP_WLOCK(inpb); 1488 if ((tcpb = intotcpcb(inpb)) != NULL) { 1489 tcp_reass_flush(tcpb); 1490 tcp_clean_sackreport(tcpb); 1491 } 1492 INP_WUNLOCK(inpb); 1493 } 1494 INP_INFO_WUNLOCK(&V_tcbinfo); 1495 CURVNET_RESTORE(); 1496 } 1497 VNET_LIST_RUNLOCK_NOSLEEP(); 1498 } 1499 1500 /* 1501 * Notify a tcp user of an asynchronous error; 1502 * store error as soft error, but wake up user 1503 * (for now, won't do anything until can select for soft error). 1504 * 1505 * Do not wake up user since there currently is no mechanism for 1506 * reporting soft errors (yet - a kqueue filter may be added). 1507 */ 1508 static struct inpcb * 1509 tcp_notify(struct inpcb *inp, int error) 1510 { 1511 struct tcpcb *tp; 1512 1513 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1514 INP_WLOCK_ASSERT(inp); 1515 1516 if ((inp->inp_flags & INP_TIMEWAIT) || 1517 (inp->inp_flags & INP_DROPPED)) 1518 return (inp); 1519 1520 tp = intotcpcb(inp); 1521 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1522 1523 /* 1524 * Ignore some errors if we are hooked up. 1525 * If connection hasn't completed, has retransmitted several times, 1526 * and receives a second error, give up now. This is better 1527 * than waiting a long time to establish a connection that 1528 * can never complete. 1529 */ 1530 if (tp->t_state == TCPS_ESTABLISHED && 1531 (error == EHOSTUNREACH || error == ENETUNREACH || 1532 error == EHOSTDOWN)) { 1533 return (inp); 1534 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1535 tp->t_softerror) { 1536 tp = tcp_drop(tp, error); 1537 if (tp != NULL) 1538 return (inp); 1539 else 1540 return (NULL); 1541 } else { 1542 tp->t_softerror = error; 1543 return (inp); 1544 } 1545 #if 0 1546 wakeup( &so->so_timeo); 1547 sorwakeup(so); 1548 sowwakeup(so); 1549 #endif 1550 } 1551 1552 static int 1553 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1554 { 1555 int error, i, m, n, pcb_count; 1556 struct inpcb *inp, **inp_list; 1557 inp_gen_t gencnt; 1558 struct xinpgen xig; 1559 1560 /* 1561 * The process of preparing the TCB list is too time-consuming and 1562 * resource-intensive to repeat twice on every request. 1563 */ 1564 if (req->oldptr == NULL) { 1565 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1566 n += imax(n / 8, 10); 1567 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1568 return (0); 1569 } 1570 1571 if (req->newptr != NULL) 1572 return (EPERM); 1573 1574 /* 1575 * OK, now we're committed to doing something. 1576 */ 1577 INP_LIST_RLOCK(&V_tcbinfo); 1578 gencnt = V_tcbinfo.ipi_gencnt; 1579 n = V_tcbinfo.ipi_count; 1580 INP_LIST_RUNLOCK(&V_tcbinfo); 1581 1582 m = syncache_pcbcount(); 1583 1584 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1585 + (n + m) * sizeof(struct xtcpcb)); 1586 if (error != 0) 1587 return (error); 1588 1589 xig.xig_len = sizeof xig; 1590 xig.xig_count = n + m; 1591 xig.xig_gen = gencnt; 1592 xig.xig_sogen = so_gencnt; 1593 error = SYSCTL_OUT(req, &xig, sizeof xig); 1594 if (error) 1595 return (error); 1596 1597 error = syncache_pcblist(req, m, &pcb_count); 1598 if (error) 1599 return (error); 1600 1601 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1602 if (inp_list == NULL) 1603 return (ENOMEM); 1604 1605 INP_INFO_WLOCK(&V_tcbinfo); 1606 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1607 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1608 INP_WLOCK(inp); 1609 if (inp->inp_gencnt <= gencnt) { 1610 /* 1611 * XXX: This use of cr_cansee(), introduced with 1612 * TCP state changes, is not quite right, but for 1613 * now, better than nothing. 1614 */ 1615 if (inp->inp_flags & INP_TIMEWAIT) { 1616 if (intotw(inp) != NULL) 1617 error = cr_cansee(req->td->td_ucred, 1618 intotw(inp)->tw_cred); 1619 else 1620 error = EINVAL; /* Skip this inp. */ 1621 } else 1622 error = cr_canseeinpcb(req->td->td_ucred, inp); 1623 if (error == 0) { 1624 in_pcbref(inp); 1625 inp_list[i++] = inp; 1626 } 1627 } 1628 INP_WUNLOCK(inp); 1629 } 1630 INP_INFO_WUNLOCK(&V_tcbinfo); 1631 n = i; 1632 1633 error = 0; 1634 for (i = 0; i < n; i++) { 1635 inp = inp_list[i]; 1636 INP_RLOCK(inp); 1637 if (inp->inp_gencnt <= gencnt) { 1638 struct xtcpcb xt; 1639 void *inp_ppcb; 1640 1641 bzero(&xt, sizeof(xt)); 1642 xt.xt_len = sizeof xt; 1643 /* XXX should avoid extra copy */ 1644 bcopy(inp, &xt.xt_inp, sizeof *inp); 1645 inp_ppcb = inp->inp_ppcb; 1646 if (inp_ppcb == NULL) 1647 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1648 else if (inp->inp_flags & INP_TIMEWAIT) { 1649 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1650 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1651 } else { 1652 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1653 if (xt.xt_tp.t_timers) 1654 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1655 } 1656 if (inp->inp_socket != NULL) 1657 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1658 else { 1659 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1660 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1661 } 1662 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1663 INP_RUNLOCK(inp); 1664 error = SYSCTL_OUT(req, &xt, sizeof xt); 1665 } else 1666 INP_RUNLOCK(inp); 1667 } 1668 INP_INFO_RLOCK(&V_tcbinfo); 1669 for (i = 0; i < n; i++) { 1670 inp = inp_list[i]; 1671 INP_RLOCK(inp); 1672 if (!in_pcbrele_rlocked(inp)) 1673 INP_RUNLOCK(inp); 1674 } 1675 INP_INFO_RUNLOCK(&V_tcbinfo); 1676 1677 if (!error) { 1678 /* 1679 * Give the user an updated idea of our state. 1680 * If the generation differs from what we told 1681 * her before, she knows that something happened 1682 * while we were processing this request, and it 1683 * might be necessary to retry. 1684 */ 1685 INP_LIST_RLOCK(&V_tcbinfo); 1686 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1687 xig.xig_sogen = so_gencnt; 1688 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1689 INP_LIST_RUNLOCK(&V_tcbinfo); 1690 error = SYSCTL_OUT(req, &xig, sizeof xig); 1691 } 1692 free(inp_list, M_TEMP); 1693 return (error); 1694 } 1695 1696 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1697 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1698 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1699 1700 #ifdef INET 1701 static int 1702 tcp_getcred(SYSCTL_HANDLER_ARGS) 1703 { 1704 struct xucred xuc; 1705 struct sockaddr_in addrs[2]; 1706 struct inpcb *inp; 1707 int error; 1708 1709 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1710 if (error) 1711 return (error); 1712 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1713 if (error) 1714 return (error); 1715 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1716 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1717 if (inp != NULL) { 1718 if (inp->inp_socket == NULL) 1719 error = ENOENT; 1720 if (error == 0) 1721 error = cr_canseeinpcb(req->td->td_ucred, inp); 1722 if (error == 0) 1723 cru2x(inp->inp_cred, &xuc); 1724 INP_RUNLOCK(inp); 1725 } else 1726 error = ENOENT; 1727 if (error == 0) 1728 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1729 return (error); 1730 } 1731 1732 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1733 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1734 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1735 #endif /* INET */ 1736 1737 #ifdef INET6 1738 static int 1739 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1740 { 1741 struct xucred xuc; 1742 struct sockaddr_in6 addrs[2]; 1743 struct inpcb *inp; 1744 int error; 1745 #ifdef INET 1746 int mapped = 0; 1747 #endif 1748 1749 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1750 if (error) 1751 return (error); 1752 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1753 if (error) 1754 return (error); 1755 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1756 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1757 return (error); 1758 } 1759 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1760 #ifdef INET 1761 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1762 mapped = 1; 1763 else 1764 #endif 1765 return (EINVAL); 1766 } 1767 1768 #ifdef INET 1769 if (mapped == 1) 1770 inp = in_pcblookup(&V_tcbinfo, 1771 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1772 addrs[1].sin6_port, 1773 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1774 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1775 else 1776 #endif 1777 inp = in6_pcblookup(&V_tcbinfo, 1778 &addrs[1].sin6_addr, addrs[1].sin6_port, 1779 &addrs[0].sin6_addr, addrs[0].sin6_port, 1780 INPLOOKUP_RLOCKPCB, NULL); 1781 if (inp != NULL) { 1782 if (inp->inp_socket == NULL) 1783 error = ENOENT; 1784 if (error == 0) 1785 error = cr_canseeinpcb(req->td->td_ucred, inp); 1786 if (error == 0) 1787 cru2x(inp->inp_cred, &xuc); 1788 INP_RUNLOCK(inp); 1789 } else 1790 error = ENOENT; 1791 if (error == 0) 1792 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1793 return (error); 1794 } 1795 1796 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1797 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1798 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1799 #endif /* INET6 */ 1800 1801 1802 #ifdef INET 1803 void 1804 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1805 { 1806 struct ip *ip = vip; 1807 struct tcphdr *th; 1808 struct in_addr faddr; 1809 struct inpcb *inp; 1810 struct tcpcb *tp; 1811 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1812 struct icmp *icp; 1813 struct in_conninfo inc; 1814 tcp_seq icmp_tcp_seq; 1815 int mtu; 1816 1817 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1818 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1819 return; 1820 1821 if (cmd == PRC_MSGSIZE) 1822 notify = tcp_mtudisc_notify; 1823 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1824 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1825 notify = tcp_drop_syn_sent; 1826 /* 1827 * Redirects don't need to be handled up here. 1828 */ 1829 else if (PRC_IS_REDIRECT(cmd)) 1830 return; 1831 /* 1832 * Hostdead is ugly because it goes linearly through all PCBs. 1833 * XXX: We never get this from ICMP, otherwise it makes an 1834 * excellent DoS attack on machines with many connections. 1835 */ 1836 else if (cmd == PRC_HOSTDEAD) 1837 ip = NULL; 1838 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1839 return; 1840 1841 if (ip == NULL) { 1842 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1843 return; 1844 } 1845 1846 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1847 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1848 INP_INFO_RLOCK(&V_tcbinfo); 1849 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1850 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1851 if (inp != NULL) { 1852 if (!(inp->inp_flags & INP_TIMEWAIT) && 1853 !(inp->inp_flags & INP_DROPPED) && 1854 !(inp->inp_socket == NULL)) { 1855 icmp_tcp_seq = ntohl(th->th_seq); 1856 tp = intotcpcb(inp); 1857 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1858 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1859 if (cmd == PRC_MSGSIZE) { 1860 /* 1861 * MTU discovery: 1862 * If we got a needfrag set the MTU 1863 * in the route to the suggested new 1864 * value (if given) and then notify. 1865 */ 1866 mtu = ntohs(icp->icmp_nextmtu); 1867 /* 1868 * If no alternative MTU was 1869 * proposed, try the next smaller 1870 * one. 1871 */ 1872 if (!mtu) 1873 mtu = ip_next_mtu( 1874 ntohs(ip->ip_len), 1); 1875 if (mtu < V_tcp_minmss + 1876 sizeof(struct tcpiphdr)) 1877 mtu = V_tcp_minmss + 1878 sizeof(struct tcpiphdr); 1879 /* 1880 * Only process the offered MTU if it 1881 * is smaller than the current one. 1882 */ 1883 if (mtu < tp->t_maxopd + 1884 sizeof(struct tcpiphdr)) { 1885 bzero(&inc, sizeof(inc)); 1886 inc.inc_faddr = faddr; 1887 inc.inc_fibnum = 1888 inp->inp_inc.inc_fibnum; 1889 tcp_hc_updatemtu(&inc, mtu); 1890 tcp_mtudisc(inp, mtu); 1891 } 1892 } else 1893 inp = (*notify)(inp, 1894 inetctlerrmap[cmd]); 1895 } 1896 } 1897 if (inp != NULL) 1898 INP_WUNLOCK(inp); 1899 } else { 1900 bzero(&inc, sizeof(inc)); 1901 inc.inc_fport = th->th_dport; 1902 inc.inc_lport = th->th_sport; 1903 inc.inc_faddr = faddr; 1904 inc.inc_laddr = ip->ip_src; 1905 syncache_unreach(&inc, th); 1906 } 1907 INP_INFO_RUNLOCK(&V_tcbinfo); 1908 } 1909 #endif /* INET */ 1910 1911 #ifdef INET6 1912 void 1913 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1914 { 1915 struct tcphdr th; 1916 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1917 struct ip6_hdr *ip6; 1918 struct mbuf *m; 1919 struct ip6ctlparam *ip6cp = NULL; 1920 const struct sockaddr_in6 *sa6_src = NULL; 1921 int off; 1922 struct tcp_portonly { 1923 u_int16_t th_sport; 1924 u_int16_t th_dport; 1925 } *thp; 1926 1927 if (sa->sa_family != AF_INET6 || 1928 sa->sa_len != sizeof(struct sockaddr_in6)) 1929 return; 1930 1931 if (cmd == PRC_MSGSIZE) 1932 notify = tcp_mtudisc_notify; 1933 else if (!PRC_IS_REDIRECT(cmd) && 1934 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1935 return; 1936 1937 /* if the parameter is from icmp6, decode it. */ 1938 if (d != NULL) { 1939 ip6cp = (struct ip6ctlparam *)d; 1940 m = ip6cp->ip6c_m; 1941 ip6 = ip6cp->ip6c_ip6; 1942 off = ip6cp->ip6c_off; 1943 sa6_src = ip6cp->ip6c_src; 1944 } else { 1945 m = NULL; 1946 ip6 = NULL; 1947 off = 0; /* fool gcc */ 1948 sa6_src = &sa6_any; 1949 } 1950 1951 if (ip6 != NULL) { 1952 struct in_conninfo inc; 1953 /* 1954 * XXX: We assume that when IPV6 is non NULL, 1955 * M and OFF are valid. 1956 */ 1957 1958 /* check if we can safely examine src and dst ports */ 1959 if (m->m_pkthdr.len < off + sizeof(*thp)) 1960 return; 1961 1962 bzero(&th, sizeof(th)); 1963 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1964 1965 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1966 (struct sockaddr *)ip6cp->ip6c_src, 1967 th.th_sport, cmd, NULL, notify); 1968 1969 bzero(&inc, sizeof(inc)); 1970 inc.inc_fport = th.th_dport; 1971 inc.inc_lport = th.th_sport; 1972 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1973 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1974 inc.inc_flags |= INC_ISIPV6; 1975 INP_INFO_RLOCK(&V_tcbinfo); 1976 syncache_unreach(&inc, &th); 1977 INP_INFO_RUNLOCK(&V_tcbinfo); 1978 } else 1979 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1980 0, cmd, NULL, notify); 1981 } 1982 #endif /* INET6 */ 1983 1984 1985 /* 1986 * Following is where TCP initial sequence number generation occurs. 1987 * 1988 * There are two places where we must use initial sequence numbers: 1989 * 1. In SYN-ACK packets. 1990 * 2. In SYN packets. 1991 * 1992 * All ISNs for SYN-ACK packets are generated by the syncache. See 1993 * tcp_syncache.c for details. 1994 * 1995 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1996 * depends on this property. In addition, these ISNs should be 1997 * unguessable so as to prevent connection hijacking. To satisfy 1998 * the requirements of this situation, the algorithm outlined in 1999 * RFC 1948 is used, with only small modifications. 2000 * 2001 * Implementation details: 2002 * 2003 * Time is based off the system timer, and is corrected so that it 2004 * increases by one megabyte per second. This allows for proper 2005 * recycling on high speed LANs while still leaving over an hour 2006 * before rollover. 2007 * 2008 * As reading the *exact* system time is too expensive to be done 2009 * whenever setting up a TCP connection, we increment the time 2010 * offset in two ways. First, a small random positive increment 2011 * is added to isn_offset for each connection that is set up. 2012 * Second, the function tcp_isn_tick fires once per clock tick 2013 * and increments isn_offset as necessary so that sequence numbers 2014 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2015 * random positive increments serve only to ensure that the same 2016 * exact sequence number is never sent out twice (as could otherwise 2017 * happen when a port is recycled in less than the system tick 2018 * interval.) 2019 * 2020 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2021 * between seeding of isn_secret. This is normally set to zero, 2022 * as reseeding should not be necessary. 2023 * 2024 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2025 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2026 * general, this means holding an exclusive (write) lock. 2027 */ 2028 2029 #define ISN_BYTES_PER_SECOND 1048576 2030 #define ISN_STATIC_INCREMENT 4096 2031 #define ISN_RANDOM_INCREMENT (4096 - 1) 2032 2033 static VNET_DEFINE(u_char, isn_secret[32]); 2034 static VNET_DEFINE(int, isn_last); 2035 static VNET_DEFINE(int, isn_last_reseed); 2036 static VNET_DEFINE(u_int32_t, isn_offset); 2037 static VNET_DEFINE(u_int32_t, isn_offset_old); 2038 2039 #define V_isn_secret VNET(isn_secret) 2040 #define V_isn_last VNET(isn_last) 2041 #define V_isn_last_reseed VNET(isn_last_reseed) 2042 #define V_isn_offset VNET(isn_offset) 2043 #define V_isn_offset_old VNET(isn_offset_old) 2044 2045 tcp_seq 2046 tcp_new_isn(struct tcpcb *tp) 2047 { 2048 MD5_CTX isn_ctx; 2049 u_int32_t md5_buffer[4]; 2050 tcp_seq new_isn; 2051 u_int32_t projected_offset; 2052 2053 INP_WLOCK_ASSERT(tp->t_inpcb); 2054 2055 ISN_LOCK(); 2056 /* Seed if this is the first use, reseed if requested. */ 2057 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2058 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2059 < (u_int)ticks))) { 2060 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2061 V_isn_last_reseed = ticks; 2062 } 2063 2064 /* Compute the md5 hash and return the ISN. */ 2065 MD5Init(&isn_ctx); 2066 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2067 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2068 #ifdef INET6 2069 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2070 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2071 sizeof(struct in6_addr)); 2072 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2073 sizeof(struct in6_addr)); 2074 } else 2075 #endif 2076 { 2077 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2078 sizeof(struct in_addr)); 2079 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2080 sizeof(struct in_addr)); 2081 } 2082 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2083 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2084 new_isn = (tcp_seq) md5_buffer[0]; 2085 V_isn_offset += ISN_STATIC_INCREMENT + 2086 (arc4random() & ISN_RANDOM_INCREMENT); 2087 if (ticks != V_isn_last) { 2088 projected_offset = V_isn_offset_old + 2089 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2090 if (SEQ_GT(projected_offset, V_isn_offset)) 2091 V_isn_offset = projected_offset; 2092 V_isn_offset_old = V_isn_offset; 2093 V_isn_last = ticks; 2094 } 2095 new_isn += V_isn_offset; 2096 ISN_UNLOCK(); 2097 return (new_isn); 2098 } 2099 2100 /* 2101 * When a specific ICMP unreachable message is received and the 2102 * connection state is SYN-SENT, drop the connection. This behavior 2103 * is controlled by the icmp_may_rst sysctl. 2104 */ 2105 struct inpcb * 2106 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2107 { 2108 struct tcpcb *tp; 2109 2110 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2111 INP_WLOCK_ASSERT(inp); 2112 2113 if ((inp->inp_flags & INP_TIMEWAIT) || 2114 (inp->inp_flags & INP_DROPPED)) 2115 return (inp); 2116 2117 tp = intotcpcb(inp); 2118 if (tp->t_state != TCPS_SYN_SENT) 2119 return (inp); 2120 2121 tp = tcp_drop(tp, errno); 2122 if (tp != NULL) 2123 return (inp); 2124 else 2125 return (NULL); 2126 } 2127 2128 /* 2129 * When `need fragmentation' ICMP is received, update our idea of the MSS 2130 * based on the new value. Also nudge TCP to send something, since we 2131 * know the packet we just sent was dropped. 2132 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2133 */ 2134 static struct inpcb * 2135 tcp_mtudisc_notify(struct inpcb *inp, int error) 2136 { 2137 2138 tcp_mtudisc(inp, -1); 2139 return (inp); 2140 } 2141 2142 static void 2143 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2144 { 2145 struct tcpcb *tp; 2146 struct socket *so; 2147 2148 INP_WLOCK_ASSERT(inp); 2149 if ((inp->inp_flags & INP_TIMEWAIT) || 2150 (inp->inp_flags & INP_DROPPED)) 2151 return; 2152 2153 tp = intotcpcb(inp); 2154 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2155 2156 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2157 2158 so = inp->inp_socket; 2159 SOCKBUF_LOCK(&so->so_snd); 2160 /* If the mss is larger than the socket buffer, decrease the mss. */ 2161 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2162 tp->t_maxseg = so->so_snd.sb_hiwat; 2163 SOCKBUF_UNLOCK(&so->so_snd); 2164 2165 TCPSTAT_INC(tcps_mturesent); 2166 tp->t_rtttime = 0; 2167 tp->snd_nxt = tp->snd_una; 2168 tcp_free_sackholes(tp); 2169 tp->snd_recover = tp->snd_max; 2170 if (tp->t_flags & TF_SACK_PERMIT) 2171 EXIT_FASTRECOVERY(tp->t_flags); 2172 tp->t_fb->tfb_tcp_output(tp); 2173 } 2174 2175 #ifdef INET 2176 /* 2177 * Look-up the routing entry to the peer of this inpcb. If no route 2178 * is found and it cannot be allocated, then return 0. This routine 2179 * is called by TCP routines that access the rmx structure and by 2180 * tcp_mss_update to get the peer/interface MTU. 2181 */ 2182 u_long 2183 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2184 { 2185 struct route sro; 2186 struct sockaddr_in *dst; 2187 struct ifnet *ifp; 2188 u_long maxmtu = 0; 2189 2190 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2191 2192 bzero(&sro, sizeof(sro)); 2193 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2194 dst = (struct sockaddr_in *)&sro.ro_dst; 2195 dst->sin_family = AF_INET; 2196 dst->sin_len = sizeof(*dst); 2197 dst->sin_addr = inc->inc_faddr; 2198 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 2199 } 2200 if (sro.ro_rt != NULL) { 2201 ifp = sro.ro_rt->rt_ifp; 2202 if (sro.ro_rt->rt_mtu == 0) 2203 maxmtu = ifp->if_mtu; 2204 else 2205 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 2206 2207 /* Report additional interface capabilities. */ 2208 if (cap != NULL) { 2209 if (ifp->if_capenable & IFCAP_TSO4 && 2210 ifp->if_hwassist & CSUM_TSO) { 2211 cap->ifcap |= CSUM_TSO; 2212 cap->tsomax = ifp->if_hw_tsomax; 2213 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2214 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2215 } 2216 } 2217 RTFREE(sro.ro_rt); 2218 } 2219 return (maxmtu); 2220 } 2221 #endif /* INET */ 2222 2223 #ifdef INET6 2224 u_long 2225 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2226 { 2227 struct route_in6 sro6; 2228 struct ifnet *ifp; 2229 u_long maxmtu = 0; 2230 2231 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2232 2233 bzero(&sro6, sizeof(sro6)); 2234 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2235 sro6.ro_dst.sin6_family = AF_INET6; 2236 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 2237 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 2238 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 2239 } 2240 if (sro6.ro_rt != NULL) { 2241 ifp = sro6.ro_rt->rt_ifp; 2242 if (sro6.ro_rt->rt_mtu == 0) 2243 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 2244 else 2245 maxmtu = min(sro6.ro_rt->rt_mtu, 2246 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 2247 2248 /* Report additional interface capabilities. */ 2249 if (cap != NULL) { 2250 if (ifp->if_capenable & IFCAP_TSO6 && 2251 ifp->if_hwassist & CSUM_TSO) { 2252 cap->ifcap |= CSUM_TSO; 2253 cap->tsomax = ifp->if_hw_tsomax; 2254 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2255 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2256 } 2257 } 2258 RTFREE(sro6.ro_rt); 2259 } 2260 2261 return (maxmtu); 2262 } 2263 #endif /* INET6 */ 2264 2265 #ifdef IPSEC 2266 /* compute ESP/AH header size for TCP, including outer IP header. */ 2267 size_t 2268 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2269 { 2270 struct inpcb *inp; 2271 struct mbuf *m; 2272 size_t hdrsiz; 2273 struct ip *ip; 2274 #ifdef INET6 2275 struct ip6_hdr *ip6; 2276 #endif 2277 struct tcphdr *th; 2278 2279 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2280 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2281 return (0); 2282 m = m_gethdr(M_NOWAIT, MT_DATA); 2283 if (!m) 2284 return (0); 2285 2286 #ifdef INET6 2287 if ((inp->inp_vflag & INP_IPV6) != 0) { 2288 ip6 = mtod(m, struct ip6_hdr *); 2289 th = (struct tcphdr *)(ip6 + 1); 2290 m->m_pkthdr.len = m->m_len = 2291 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2292 tcpip_fillheaders(inp, ip6, th); 2293 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2294 } else 2295 #endif /* INET6 */ 2296 { 2297 ip = mtod(m, struct ip *); 2298 th = (struct tcphdr *)(ip + 1); 2299 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2300 tcpip_fillheaders(inp, ip, th); 2301 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2302 } 2303 2304 m_free(m); 2305 return (hdrsiz); 2306 } 2307 #endif /* IPSEC */ 2308 2309 #ifdef TCP_SIGNATURE 2310 /* 2311 * Callback function invoked by m_apply() to digest TCP segment data 2312 * contained within an mbuf chain. 2313 */ 2314 static int 2315 tcp_signature_apply(void *fstate, void *data, u_int len) 2316 { 2317 2318 MD5Update(fstate, (u_char *)data, len); 2319 return (0); 2320 } 2321 2322 /* 2323 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2324 * search with the destination IP address, and a 'magic SPI' to be 2325 * determined by the application. This is hardcoded elsewhere to 1179 2326 */ 2327 struct secasvar * 2328 tcp_get_sav(struct mbuf *m, u_int direction) 2329 { 2330 union sockaddr_union dst; 2331 struct secasvar *sav; 2332 struct ip *ip; 2333 #ifdef INET6 2334 struct ip6_hdr *ip6; 2335 char ip6buf[INET6_ADDRSTRLEN]; 2336 #endif 2337 2338 /* Extract the destination from the IP header in the mbuf. */ 2339 bzero(&dst, sizeof(union sockaddr_union)); 2340 ip = mtod(m, struct ip *); 2341 #ifdef INET6 2342 ip6 = NULL; /* Make the compiler happy. */ 2343 #endif 2344 switch (ip->ip_v) { 2345 #ifdef INET 2346 case IPVERSION: 2347 dst.sa.sa_len = sizeof(struct sockaddr_in); 2348 dst.sa.sa_family = AF_INET; 2349 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2350 ip->ip_src : ip->ip_dst; 2351 break; 2352 #endif 2353 #ifdef INET6 2354 case (IPV6_VERSION >> 4): 2355 ip6 = mtod(m, struct ip6_hdr *); 2356 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2357 dst.sa.sa_family = AF_INET6; 2358 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2359 ip6->ip6_src : ip6->ip6_dst; 2360 break; 2361 #endif 2362 default: 2363 return (NULL); 2364 /* NOTREACHED */ 2365 break; 2366 } 2367 2368 /* Look up an SADB entry which matches the address of the peer. */ 2369 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2370 if (sav == NULL) { 2371 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2372 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2373 #ifdef INET6 2374 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2375 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2376 #endif 2377 "(unsupported)")); 2378 } 2379 2380 return (sav); 2381 } 2382 2383 /* 2384 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2385 * 2386 * Parameters: 2387 * m pointer to head of mbuf chain 2388 * len length of TCP segment data, excluding options 2389 * optlen length of TCP segment options 2390 * buf pointer to storage for computed MD5 digest 2391 * sav pointer to security assosiation 2392 * 2393 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2394 * When called from tcp_input(), we can be sure that th_sum has been 2395 * zeroed out and verified already. 2396 * 2397 * Releases reference to SADB key before return. 2398 * 2399 * Return 0 if successful, otherwise return -1. 2400 * 2401 */ 2402 int 2403 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2404 u_char *buf, struct secasvar *sav) 2405 { 2406 #ifdef INET 2407 struct ippseudo ippseudo; 2408 #endif 2409 MD5_CTX ctx; 2410 int doff; 2411 struct ip *ip; 2412 #ifdef INET 2413 struct ipovly *ipovly; 2414 #endif 2415 struct tcphdr *th; 2416 #ifdef INET6 2417 struct ip6_hdr *ip6; 2418 struct in6_addr in6; 2419 uint32_t plen; 2420 uint16_t nhdr; 2421 #endif 2422 u_short savecsum; 2423 2424 KASSERT(m != NULL, ("NULL mbuf chain")); 2425 KASSERT(buf != NULL, ("NULL signature pointer")); 2426 2427 /* Extract the destination from the IP header in the mbuf. */ 2428 ip = mtod(m, struct ip *); 2429 #ifdef INET6 2430 ip6 = NULL; /* Make the compiler happy. */ 2431 #endif 2432 2433 MD5Init(&ctx); 2434 /* 2435 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2436 * 2437 * XXX The ippseudo header MUST be digested in network byte order, 2438 * or else we'll fail the regression test. Assume all fields we've 2439 * been doing arithmetic on have been in host byte order. 2440 * XXX One cannot depend on ipovly->ih_len here. When called from 2441 * tcp_output(), the underlying ip_len member has not yet been set. 2442 */ 2443 switch (ip->ip_v) { 2444 #ifdef INET 2445 case IPVERSION: 2446 ipovly = (struct ipovly *)ip; 2447 ippseudo.ippseudo_src = ipovly->ih_src; 2448 ippseudo.ippseudo_dst = ipovly->ih_dst; 2449 ippseudo.ippseudo_pad = 0; 2450 ippseudo.ippseudo_p = IPPROTO_TCP; 2451 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2452 optlen); 2453 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2454 2455 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2456 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2457 break; 2458 #endif 2459 #ifdef INET6 2460 /* 2461 * RFC 2385, 2.0 Proposal 2462 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2463 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2464 * extended next header value (to form 32 bits), and 32-bit segment 2465 * length. 2466 * Note: Upper-Layer Packet Length comes before Next Header. 2467 */ 2468 case (IPV6_VERSION >> 4): 2469 in6 = ip6->ip6_src; 2470 in6_clearscope(&in6); 2471 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2472 in6 = ip6->ip6_dst; 2473 in6_clearscope(&in6); 2474 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2475 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2476 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2477 nhdr = 0; 2478 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2479 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2480 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2481 nhdr = IPPROTO_TCP; 2482 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2483 2484 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2485 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2486 break; 2487 #endif 2488 default: 2489 KEY_FREESAV(&sav); 2490 return (-1); 2491 /* NOTREACHED */ 2492 break; 2493 } 2494 2495 2496 /* 2497 * Step 2: Update MD5 hash with TCP header, excluding options. 2498 * The TCP checksum must be set to zero. 2499 */ 2500 savecsum = th->th_sum; 2501 th->th_sum = 0; 2502 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2503 th->th_sum = savecsum; 2504 2505 /* 2506 * Step 3: Update MD5 hash with TCP segment data. 2507 * Use m_apply() to avoid an early m_pullup(). 2508 */ 2509 if (len > 0) 2510 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2511 2512 /* 2513 * Step 4: Update MD5 hash with shared secret. 2514 */ 2515 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2516 MD5Final(buf, &ctx); 2517 2518 key_sa_recordxfer(sav, m); 2519 KEY_FREESAV(&sav); 2520 return (0); 2521 } 2522 2523 /* 2524 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2525 * 2526 * Return 0 if successful, otherwise return -1. 2527 */ 2528 int 2529 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2530 u_char *buf, u_int direction) 2531 { 2532 struct secasvar *sav; 2533 2534 if ((sav = tcp_get_sav(m, direction)) == NULL) 2535 return (-1); 2536 2537 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2538 } 2539 2540 /* 2541 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2542 * 2543 * Parameters: 2544 * m pointer to head of mbuf chain 2545 * len length of TCP segment data, excluding options 2546 * optlen length of TCP segment options 2547 * buf pointer to storage for computed MD5 digest 2548 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2549 * 2550 * Return 1 if successful, otherwise return 0. 2551 */ 2552 int 2553 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2554 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2555 { 2556 char tmpdigest[TCP_SIGLEN]; 2557 2558 if (tcp_sig_checksigs == 0) 2559 return (1); 2560 if ((tcpbflag & TF_SIGNATURE) == 0) { 2561 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2562 2563 /* 2564 * If this socket is not expecting signature but 2565 * the segment contains signature just fail. 2566 */ 2567 TCPSTAT_INC(tcps_sig_err_sigopt); 2568 TCPSTAT_INC(tcps_sig_rcvbadsig); 2569 return (0); 2570 } 2571 2572 /* Signature is not expected, and not present in segment. */ 2573 return (1); 2574 } 2575 2576 /* 2577 * If this socket is expecting signature but the segment does not 2578 * contain any just fail. 2579 */ 2580 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2581 TCPSTAT_INC(tcps_sig_err_nosigopt); 2582 TCPSTAT_INC(tcps_sig_rcvbadsig); 2583 return (0); 2584 } 2585 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2586 IPSEC_DIR_INBOUND) == -1) { 2587 TCPSTAT_INC(tcps_sig_err_buildsig); 2588 TCPSTAT_INC(tcps_sig_rcvbadsig); 2589 return (0); 2590 } 2591 2592 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2593 TCPSTAT_INC(tcps_sig_rcvbadsig); 2594 return (0); 2595 } 2596 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2597 return (1); 2598 } 2599 #endif /* TCP_SIGNATURE */ 2600 2601 static int 2602 sysctl_drop(SYSCTL_HANDLER_ARGS) 2603 { 2604 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2605 struct sockaddr_storage addrs[2]; 2606 struct inpcb *inp; 2607 struct tcpcb *tp; 2608 struct tcptw *tw; 2609 struct sockaddr_in *fin, *lin; 2610 #ifdef INET6 2611 struct sockaddr_in6 *fin6, *lin6; 2612 #endif 2613 int error; 2614 2615 inp = NULL; 2616 fin = lin = NULL; 2617 #ifdef INET6 2618 fin6 = lin6 = NULL; 2619 #endif 2620 error = 0; 2621 2622 if (req->oldptr != NULL || req->oldlen != 0) 2623 return (EINVAL); 2624 if (req->newptr == NULL) 2625 return (EPERM); 2626 if (req->newlen < sizeof(addrs)) 2627 return (ENOMEM); 2628 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2629 if (error) 2630 return (error); 2631 2632 switch (addrs[0].ss_family) { 2633 #ifdef INET6 2634 case AF_INET6: 2635 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2636 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2637 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2638 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2639 return (EINVAL); 2640 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2641 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2642 return (EINVAL); 2643 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2644 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2645 fin = (struct sockaddr_in *)&addrs[0]; 2646 lin = (struct sockaddr_in *)&addrs[1]; 2647 break; 2648 } 2649 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2650 if (error) 2651 return (error); 2652 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2653 if (error) 2654 return (error); 2655 break; 2656 #endif 2657 #ifdef INET 2658 case AF_INET: 2659 fin = (struct sockaddr_in *)&addrs[0]; 2660 lin = (struct sockaddr_in *)&addrs[1]; 2661 if (fin->sin_len != sizeof(struct sockaddr_in) || 2662 lin->sin_len != sizeof(struct sockaddr_in)) 2663 return (EINVAL); 2664 break; 2665 #endif 2666 default: 2667 return (EINVAL); 2668 } 2669 INP_INFO_RLOCK(&V_tcbinfo); 2670 switch (addrs[0].ss_family) { 2671 #ifdef INET6 2672 case AF_INET6: 2673 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2674 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2675 INPLOOKUP_WLOCKPCB, NULL); 2676 break; 2677 #endif 2678 #ifdef INET 2679 case AF_INET: 2680 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2681 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2682 break; 2683 #endif 2684 } 2685 if (inp != NULL) { 2686 if (inp->inp_flags & INP_TIMEWAIT) { 2687 /* 2688 * XXXRW: There currently exists a state where an 2689 * inpcb is present, but its timewait state has been 2690 * discarded. For now, don't allow dropping of this 2691 * type of inpcb. 2692 */ 2693 tw = intotw(inp); 2694 if (tw != NULL) 2695 tcp_twclose(tw, 0); 2696 else 2697 INP_WUNLOCK(inp); 2698 } else if (!(inp->inp_flags & INP_DROPPED) && 2699 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2700 tp = intotcpcb(inp); 2701 tp = tcp_drop(tp, ECONNABORTED); 2702 if (tp != NULL) 2703 INP_WUNLOCK(inp); 2704 } else 2705 INP_WUNLOCK(inp); 2706 } else 2707 error = ESRCH; 2708 INP_INFO_RUNLOCK(&V_tcbinfo); 2709 return (error); 2710 } 2711 2712 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2713 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2714 0, sysctl_drop, "", "Drop TCP connection"); 2715 2716 /* 2717 * Generate a standardized TCP log line for use throughout the 2718 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2719 * allow use in the interrupt context. 2720 * 2721 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2722 * NB: The function may return NULL if memory allocation failed. 2723 * 2724 * Due to header inclusion and ordering limitations the struct ip 2725 * and ip6_hdr pointers have to be passed as void pointers. 2726 */ 2727 char * 2728 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2729 const void *ip6hdr) 2730 { 2731 2732 /* Is logging enabled? */ 2733 if (tcp_log_in_vain == 0) 2734 return (NULL); 2735 2736 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2737 } 2738 2739 char * 2740 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2741 const void *ip6hdr) 2742 { 2743 2744 /* Is logging enabled? */ 2745 if (tcp_log_debug == 0) 2746 return (NULL); 2747 2748 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2749 } 2750 2751 static char * 2752 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2753 const void *ip6hdr) 2754 { 2755 char *s, *sp; 2756 size_t size; 2757 struct ip *ip; 2758 #ifdef INET6 2759 const struct ip6_hdr *ip6; 2760 2761 ip6 = (const struct ip6_hdr *)ip6hdr; 2762 #endif /* INET6 */ 2763 ip = (struct ip *)ip4hdr; 2764 2765 /* 2766 * The log line looks like this: 2767 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2768 */ 2769 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2770 sizeof(PRINT_TH_FLAGS) + 1 + 2771 #ifdef INET6 2772 2 * INET6_ADDRSTRLEN; 2773 #else 2774 2 * INET_ADDRSTRLEN; 2775 #endif /* INET6 */ 2776 2777 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2778 if (s == NULL) 2779 return (NULL); 2780 2781 strcat(s, "TCP: ["); 2782 sp = s + strlen(s); 2783 2784 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2785 inet_ntoa_r(inc->inc_faddr, sp); 2786 sp = s + strlen(s); 2787 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2788 sp = s + strlen(s); 2789 inet_ntoa_r(inc->inc_laddr, sp); 2790 sp = s + strlen(s); 2791 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2792 #ifdef INET6 2793 } else if (inc) { 2794 ip6_sprintf(sp, &inc->inc6_faddr); 2795 sp = s + strlen(s); 2796 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2797 sp = s + strlen(s); 2798 ip6_sprintf(sp, &inc->inc6_laddr); 2799 sp = s + strlen(s); 2800 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2801 } else if (ip6 && th) { 2802 ip6_sprintf(sp, &ip6->ip6_src); 2803 sp = s + strlen(s); 2804 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2805 sp = s + strlen(s); 2806 ip6_sprintf(sp, &ip6->ip6_dst); 2807 sp = s + strlen(s); 2808 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2809 #endif /* INET6 */ 2810 #ifdef INET 2811 } else if (ip && th) { 2812 inet_ntoa_r(ip->ip_src, sp); 2813 sp = s + strlen(s); 2814 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2815 sp = s + strlen(s); 2816 inet_ntoa_r(ip->ip_dst, sp); 2817 sp = s + strlen(s); 2818 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2819 #endif /* INET */ 2820 } else { 2821 free(s, M_TCPLOG); 2822 return (NULL); 2823 } 2824 sp = s + strlen(s); 2825 if (th) 2826 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2827 if (*(s + size - 1) != '\0') 2828 panic("%s: string too long", __func__); 2829 return (s); 2830 } 2831 2832 /* 2833 * A subroutine which makes it easy to track TCP state changes with DTrace. 2834 * This function shouldn't be called for t_state initializations that don't 2835 * correspond to actual TCP state transitions. 2836 */ 2837 void 2838 tcp_state_change(struct tcpcb *tp, int newstate) 2839 { 2840 #if defined(KDTRACE_HOOKS) 2841 int pstate = tp->t_state; 2842 #endif 2843 2844 tp->t_state = newstate; 2845 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2846 } 2847