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 #ifdef TCP_RFC7413 88 #include <netinet/tcp_fastopen.h> 89 #endif 90 #include <netinet/tcp_fsm.h> 91 #include <netinet/tcp_seq.h> 92 #include <netinet/tcp_timer.h> 93 #include <netinet/tcp_var.h> 94 #include <netinet/tcp_syncache.h> 95 #ifdef INET6 96 #include <netinet6/tcp6_var.h> 97 #endif 98 #include <netinet/tcpip.h> 99 #ifdef TCPPCAP 100 #include <netinet/tcp_pcap.h> 101 #endif 102 #ifdef TCPDEBUG 103 #include <netinet/tcp_debug.h> 104 #endif 105 #ifdef INET6 106 #include <netinet6/ip6protosw.h> 107 #endif 108 #ifdef TCP_OFFLOAD 109 #include <netinet/tcp_offload.h> 110 #endif 111 112 #ifdef IPSEC 113 #include <netipsec/ipsec.h> 114 #include <netipsec/xform.h> 115 #ifdef INET6 116 #include <netipsec/ipsec6.h> 117 #endif 118 #include <netipsec/key.h> 119 #include <sys/syslog.h> 120 #endif /*IPSEC*/ 121 122 #include <machine/in_cksum.h> 123 #include <sys/md5.h> 124 125 #include <security/mac/mac_framework.h> 126 127 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 128 #ifdef INET6 129 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 130 #endif 131 132 struct rwlock tcp_function_lock; 133 134 static int 135 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 136 { 137 int error, new; 138 139 new = V_tcp_mssdflt; 140 error = sysctl_handle_int(oidp, &new, 0, req); 141 if (error == 0 && req->newptr) { 142 if (new < TCP_MINMSS) 143 error = EINVAL; 144 else 145 V_tcp_mssdflt = new; 146 } 147 return (error); 148 } 149 150 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 151 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 152 &sysctl_net_inet_tcp_mss_check, "I", 153 "Default TCP Maximum Segment Size"); 154 155 #ifdef INET6 156 static int 157 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 158 { 159 int error, new; 160 161 new = V_tcp_v6mssdflt; 162 error = sysctl_handle_int(oidp, &new, 0, req); 163 if (error == 0 && req->newptr) { 164 if (new < TCP_MINMSS) 165 error = EINVAL; 166 else 167 V_tcp_v6mssdflt = new; 168 } 169 return (error); 170 } 171 172 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 173 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 174 &sysctl_net_inet_tcp_mss_v6_check, "I", 175 "Default TCP Maximum Segment Size for IPv6"); 176 #endif /* INET6 */ 177 178 /* 179 * Minimum MSS we accept and use. This prevents DoS attacks where 180 * we are forced to a ridiculous low MSS like 20 and send hundreds 181 * of packets instead of one. The effect scales with the available 182 * bandwidth and quickly saturates the CPU and network interface 183 * with packet generation and sending. Set to zero to disable MINMSS 184 * checking. This setting prevents us from sending too small packets. 185 */ 186 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 187 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 188 &VNET_NAME(tcp_minmss), 0, 189 "Minimum TCP Maximum Segment Size"); 190 191 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 192 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 193 &VNET_NAME(tcp_do_rfc1323), 0, 194 "Enable rfc1323 (high performance TCP) extensions"); 195 196 static int tcp_log_debug = 0; 197 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 198 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 199 200 static int tcp_tcbhashsize; 201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 202 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 203 204 static int do_tcpdrain = 1; 205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 206 "Enable tcp_drain routine for extra help when low on mbufs"); 207 208 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 209 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 210 211 static VNET_DEFINE(int, icmp_may_rst) = 1; 212 #define V_icmp_may_rst VNET(icmp_may_rst) 213 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 214 &VNET_NAME(icmp_may_rst), 0, 215 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 216 217 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 218 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 219 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 220 &VNET_NAME(tcp_isn_reseed_interval), 0, 221 "Seconds between reseeding of ISN secret"); 222 223 static int tcp_soreceive_stream; 224 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 225 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 226 227 #ifdef TCP_SIGNATURE 228 static int tcp_sig_checksigs = 1; 229 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 230 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 231 #endif 232 233 VNET_DEFINE(uma_zone_t, sack_hole_zone); 234 #define V_sack_hole_zone VNET(sack_hole_zone) 235 236 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 237 238 static struct inpcb *tcp_notify(struct inpcb *, int); 239 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 240 static void tcp_mtudisc(struct inpcb *, int); 241 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 242 void *ip4hdr, const void *ip6hdr); 243 static void tcp_timer_discard(struct tcpcb *, uint32_t); 244 245 246 static struct tcp_function_block tcp_def_funcblk = { 247 "default", 248 tcp_output, 249 tcp_do_segment, 250 tcp_default_ctloutput, 251 NULL, 252 NULL, 253 NULL, 254 NULL, 255 NULL, 256 NULL, 257 NULL, 258 0, 259 0 260 }; 261 262 struct tcp_funchead t_functions; 263 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 264 265 static struct tcp_function_block * 266 find_tcp_functions_locked(struct tcp_function_set *fs) 267 { 268 struct tcp_function *f; 269 struct tcp_function_block *blk=NULL; 270 271 TAILQ_FOREACH(f, &t_functions, tf_next) { 272 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 273 blk = f->tf_fb; 274 break; 275 } 276 } 277 return(blk); 278 } 279 280 static struct tcp_function_block * 281 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 282 { 283 struct tcp_function_block *rblk=NULL; 284 struct tcp_function *f; 285 286 TAILQ_FOREACH(f, &t_functions, tf_next) { 287 if (f->tf_fb == blk) { 288 rblk = blk; 289 if (s) { 290 *s = f; 291 } 292 break; 293 } 294 } 295 return (rblk); 296 } 297 298 struct tcp_function_block * 299 find_and_ref_tcp_functions(struct tcp_function_set *fs) 300 { 301 struct tcp_function_block *blk; 302 303 rw_rlock(&tcp_function_lock); 304 blk = find_tcp_functions_locked(fs); 305 if (blk) 306 refcount_acquire(&blk->tfb_refcnt); 307 rw_runlock(&tcp_function_lock); 308 return(blk); 309 } 310 311 struct tcp_function_block * 312 find_and_ref_tcp_fb(struct tcp_function_block *blk) 313 { 314 struct tcp_function_block *rblk; 315 316 rw_rlock(&tcp_function_lock); 317 rblk = find_tcp_fb_locked(blk, NULL); 318 if (rblk) 319 refcount_acquire(&rblk->tfb_refcnt); 320 rw_runlock(&tcp_function_lock); 321 return(rblk); 322 } 323 324 325 static int 326 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 327 { 328 int error=ENOENT; 329 struct tcp_function_set fs; 330 struct tcp_function_block *blk; 331 332 memset(&fs, 0, sizeof(fs)); 333 rw_rlock(&tcp_function_lock); 334 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 335 if (blk) { 336 /* Found him */ 337 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 338 fs.pcbcnt = blk->tfb_refcnt; 339 } 340 rw_runlock(&tcp_function_lock); 341 error = sysctl_handle_string(oidp, fs.function_set_name, 342 sizeof(fs.function_set_name), req); 343 344 /* Check for error or no change */ 345 if (error != 0 || req->newptr == NULL) 346 return(error); 347 348 rw_wlock(&tcp_function_lock); 349 blk = find_tcp_functions_locked(&fs); 350 if ((blk == NULL) || 351 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 352 error = ENOENT; 353 goto done; 354 } 355 tcp_func_set_ptr = blk; 356 done: 357 rw_wunlock(&tcp_function_lock); 358 return (error); 359 } 360 361 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 362 CTLTYPE_STRING | CTLFLAG_RW, 363 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 364 "Set/get the default TCP functions"); 365 366 static int 367 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 368 { 369 int error, cnt, linesz; 370 struct tcp_function *f; 371 char *buffer, *cp; 372 size_t bufsz, outsz; 373 374 cnt = 0; 375 rw_rlock(&tcp_function_lock); 376 TAILQ_FOREACH(f, &t_functions, tf_next) { 377 cnt++; 378 } 379 rw_runlock(&tcp_function_lock); 380 381 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 382 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 383 384 error = 0; 385 cp = buffer; 386 387 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 388 cp += linesz; 389 bufsz -= linesz; 390 outsz = linesz; 391 392 rw_rlock(&tcp_function_lock); 393 TAILQ_FOREACH(f, &t_functions, tf_next) { 394 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 395 f->tf_fb->tfb_tcp_block_name, 396 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 397 f->tf_fb->tfb_refcnt); 398 if (linesz >= bufsz) { 399 error = EOVERFLOW; 400 break; 401 } 402 cp += linesz; 403 bufsz -= linesz; 404 outsz += linesz; 405 } 406 rw_runlock(&tcp_function_lock); 407 if (error == 0) 408 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 409 free(buffer, M_TEMP); 410 return (error); 411 } 412 413 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 414 CTLTYPE_STRING|CTLFLAG_RD, 415 NULL, 0, sysctl_net_inet_list_available, "A", 416 "list available TCP Function sets"); 417 418 /* 419 * Target size of TCP PCB hash tables. Must be a power of two. 420 * 421 * Note that this can be overridden by the kernel environment 422 * variable net.inet.tcp.tcbhashsize 423 */ 424 #ifndef TCBHASHSIZE 425 #define TCBHASHSIZE 0 426 #endif 427 428 /* 429 * XXX 430 * Callouts should be moved into struct tcp directly. They are currently 431 * separate because the tcpcb structure is exported to userland for sysctl 432 * parsing purposes, which do not know about callouts. 433 */ 434 struct tcpcb_mem { 435 struct tcpcb tcb; 436 struct tcp_timer tt; 437 struct cc_var ccv; 438 struct osd osd; 439 }; 440 441 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 442 #define V_tcpcb_zone VNET(tcpcb_zone) 443 444 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 445 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 446 447 static struct mtx isn_mtx; 448 449 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 450 #define ISN_LOCK() mtx_lock(&isn_mtx) 451 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 452 453 /* 454 * TCP initialization. 455 */ 456 static void 457 tcp_zone_change(void *tag) 458 { 459 460 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 461 uma_zone_set_max(V_tcpcb_zone, maxsockets); 462 tcp_tw_zone_change(); 463 } 464 465 static int 466 tcp_inpcb_init(void *mem, int size, int flags) 467 { 468 struct inpcb *inp = mem; 469 470 INP_LOCK_INIT(inp, "inp", "tcpinp"); 471 return (0); 472 } 473 474 /* 475 * Take a value and get the next power of 2 that doesn't overflow. 476 * Used to size the tcp_inpcb hash buckets. 477 */ 478 static int 479 maketcp_hashsize(int size) 480 { 481 int hashsize; 482 483 /* 484 * auto tune. 485 * get the next power of 2 higher than maxsockets. 486 */ 487 hashsize = 1 << fls(size); 488 /* catch overflow, and just go one power of 2 smaller */ 489 if (hashsize < size) { 490 hashsize = 1 << (fls(size) - 1); 491 } 492 return (hashsize); 493 } 494 495 int 496 register_tcp_functions(struct tcp_function_block *blk, int wait) 497 { 498 struct tcp_function_block *lblk; 499 struct tcp_function *n; 500 struct tcp_function_set fs; 501 502 if ((blk->tfb_tcp_output == NULL) || 503 (blk->tfb_tcp_do_segment == NULL) || 504 (blk->tfb_tcp_ctloutput == NULL) || 505 (strlen(blk->tfb_tcp_block_name) == 0)) { 506 /* 507 * These functions are required and you 508 * need a name. 509 */ 510 return (EINVAL); 511 } 512 if (blk->tfb_tcp_timer_stop_all || 513 blk->tfb_tcp_timers_left || 514 blk->tfb_tcp_timer_activate || 515 blk->tfb_tcp_timer_active || 516 blk->tfb_tcp_timer_stop) { 517 /* 518 * If you define one timer function you 519 * must have them all. 520 */ 521 if ((blk->tfb_tcp_timer_stop_all == NULL) || 522 (blk->tfb_tcp_timers_left == NULL) || 523 (blk->tfb_tcp_timer_activate == NULL) || 524 (blk->tfb_tcp_timer_active == NULL) || 525 (blk->tfb_tcp_timer_stop == NULL)) { 526 return (EINVAL); 527 } 528 } 529 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 530 if (n == NULL) { 531 return (ENOMEM); 532 } 533 n->tf_fb = blk; 534 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 535 rw_wlock(&tcp_function_lock); 536 lblk = find_tcp_functions_locked(&fs); 537 if (lblk) { 538 /* Duplicate name space not allowed */ 539 rw_wunlock(&tcp_function_lock); 540 free(n, M_TCPFUNCTIONS); 541 return (EALREADY); 542 } 543 refcount_init(&blk->tfb_refcnt, 0); 544 blk->tfb_flags = 0; 545 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 546 rw_wunlock(&tcp_function_lock); 547 return(0); 548 } 549 550 int 551 deregister_tcp_functions(struct tcp_function_block *blk) 552 { 553 struct tcp_function_block *lblk; 554 struct tcp_function *f; 555 int error=ENOENT; 556 557 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 558 /* You can't un-register the default */ 559 return (EPERM); 560 } 561 rw_wlock(&tcp_function_lock); 562 if (blk == tcp_func_set_ptr) { 563 /* You can't free the current default */ 564 rw_wunlock(&tcp_function_lock); 565 return (EBUSY); 566 } 567 if (blk->tfb_refcnt) { 568 /* Still tcb attached, mark it. */ 569 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 570 rw_wunlock(&tcp_function_lock); 571 return (EBUSY); 572 } 573 lblk = find_tcp_fb_locked(blk, &f); 574 if (lblk) { 575 /* Found */ 576 TAILQ_REMOVE(&t_functions, f, tf_next); 577 f->tf_fb = NULL; 578 free(f, M_TCPFUNCTIONS); 579 error = 0; 580 } 581 rw_wunlock(&tcp_function_lock); 582 return (error); 583 } 584 585 void 586 tcp_init(void) 587 { 588 const char *tcbhash_tuneable; 589 int hashsize; 590 591 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 592 593 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 594 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 595 printf("%s: WARNING: unable to register helper hook\n", __func__); 596 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 597 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 598 printf("%s: WARNING: unable to register helper hook\n", __func__); 599 hashsize = TCBHASHSIZE; 600 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 601 if (hashsize == 0) { 602 /* 603 * Auto tune the hash size based on maxsockets. 604 * A perfect hash would have a 1:1 mapping 605 * (hashsize = maxsockets) however it's been 606 * suggested that O(2) average is better. 607 */ 608 hashsize = maketcp_hashsize(maxsockets / 4); 609 /* 610 * Our historical default is 512, 611 * do not autotune lower than this. 612 */ 613 if (hashsize < 512) 614 hashsize = 512; 615 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 616 printf("%s: %s auto tuned to %d\n", __func__, 617 tcbhash_tuneable, hashsize); 618 } 619 /* 620 * We require a hashsize to be a power of two. 621 * Previously if it was not a power of two we would just reset it 622 * back to 512, which could be a nasty surprise if you did not notice 623 * the error message. 624 * Instead what we do is clip it to the closest power of two lower 625 * than the specified hash value. 626 */ 627 if (!powerof2(hashsize)) { 628 int oldhashsize = hashsize; 629 630 hashsize = maketcp_hashsize(hashsize); 631 /* prevent absurdly low value */ 632 if (hashsize < 16) 633 hashsize = 16; 634 printf("%s: WARNING: TCB hash size not a power of 2, " 635 "clipped from %d to %d.\n", __func__, oldhashsize, 636 hashsize); 637 } 638 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 639 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 640 IPI_HASHFIELDS_4TUPLE); 641 642 /* 643 * These have to be type stable for the benefit of the timers. 644 */ 645 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 646 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 647 uma_zone_set_max(V_tcpcb_zone, maxsockets); 648 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 649 650 tcp_tw_init(); 651 syncache_init(); 652 tcp_hc_init(); 653 654 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 655 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 656 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 657 658 /* Skip initialization of globals for non-default instances. */ 659 if (!IS_DEFAULT_VNET(curvnet)) 660 return; 661 662 tcp_reass_global_init(); 663 664 /* XXX virtualize those bellow? */ 665 tcp_delacktime = TCPTV_DELACK; 666 tcp_keepinit = TCPTV_KEEP_INIT; 667 tcp_keepidle = TCPTV_KEEP_IDLE; 668 tcp_keepintvl = TCPTV_KEEPINTVL; 669 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 670 tcp_msl = TCPTV_MSL; 671 tcp_rexmit_min = TCPTV_MIN; 672 if (tcp_rexmit_min < 1) 673 tcp_rexmit_min = 1; 674 tcp_rexmit_slop = TCPTV_CPU_VAR; 675 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 676 tcp_tcbhashsize = hashsize; 677 /* Setup the tcp function block list */ 678 TAILQ_INIT(&t_functions); 679 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 680 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 681 682 if (tcp_soreceive_stream) { 683 #ifdef INET 684 tcp_usrreqs.pru_soreceive = soreceive_stream; 685 #endif 686 #ifdef INET6 687 tcp6_usrreqs.pru_soreceive = soreceive_stream; 688 #endif /* INET6 */ 689 } 690 691 #ifdef INET6 692 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 693 #else /* INET6 */ 694 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 695 #endif /* INET6 */ 696 if (max_protohdr < TCP_MINPROTOHDR) 697 max_protohdr = TCP_MINPROTOHDR; 698 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 699 panic("tcp_init"); 700 #undef TCP_MINPROTOHDR 701 702 ISN_LOCK_INIT(); 703 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 704 SHUTDOWN_PRI_DEFAULT); 705 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 706 EVENTHANDLER_PRI_ANY); 707 #ifdef TCPPCAP 708 tcp_pcap_init(); 709 #endif 710 711 #ifdef TCP_RFC7413 712 tcp_fastopen_init(); 713 #endif 714 } 715 716 #ifdef VIMAGE 717 void 718 tcp_destroy(void) 719 { 720 int error; 721 722 #ifdef TCP_RFC7413 723 tcp_fastopen_destroy(); 724 #endif 725 tcp_hc_destroy(); 726 syncache_destroy(); 727 tcp_tw_destroy(); 728 in_pcbinfo_destroy(&V_tcbinfo); 729 uma_zdestroy(V_sack_hole_zone); 730 uma_zdestroy(V_tcpcb_zone); 731 732 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 733 if (error != 0) { 734 printf("%s: WARNING: unable to deregister helper hook " 735 "type=%d, id=%d: error %d returned\n", __func__, 736 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 737 } 738 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 739 if (error != 0) { 740 printf("%s: WARNING: unable to deregister helper hook " 741 "type=%d, id=%d: error %d returned\n", __func__, 742 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 743 } 744 } 745 #endif 746 747 void 748 tcp_fini(void *xtp) 749 { 750 751 } 752 753 /* 754 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 755 * tcp_template used to store this data in mbufs, but we now recopy it out 756 * of the tcpcb each time to conserve mbufs. 757 */ 758 void 759 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 760 { 761 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 762 763 INP_WLOCK_ASSERT(inp); 764 765 #ifdef INET6 766 if ((inp->inp_vflag & INP_IPV6) != 0) { 767 struct ip6_hdr *ip6; 768 769 ip6 = (struct ip6_hdr *)ip_ptr; 770 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 771 (inp->inp_flow & IPV6_FLOWINFO_MASK); 772 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 773 (IPV6_VERSION & IPV6_VERSION_MASK); 774 ip6->ip6_nxt = IPPROTO_TCP; 775 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 776 ip6->ip6_src = inp->in6p_laddr; 777 ip6->ip6_dst = inp->in6p_faddr; 778 } 779 #endif /* INET6 */ 780 #if defined(INET6) && defined(INET) 781 else 782 #endif 783 #ifdef INET 784 { 785 struct ip *ip; 786 787 ip = (struct ip *)ip_ptr; 788 ip->ip_v = IPVERSION; 789 ip->ip_hl = 5; 790 ip->ip_tos = inp->inp_ip_tos; 791 ip->ip_len = 0; 792 ip->ip_id = 0; 793 ip->ip_off = 0; 794 ip->ip_ttl = inp->inp_ip_ttl; 795 ip->ip_sum = 0; 796 ip->ip_p = IPPROTO_TCP; 797 ip->ip_src = inp->inp_laddr; 798 ip->ip_dst = inp->inp_faddr; 799 } 800 #endif /* INET */ 801 th->th_sport = inp->inp_lport; 802 th->th_dport = inp->inp_fport; 803 th->th_seq = 0; 804 th->th_ack = 0; 805 th->th_x2 = 0; 806 th->th_off = 5; 807 th->th_flags = 0; 808 th->th_win = 0; 809 th->th_urp = 0; 810 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 811 } 812 813 /* 814 * Create template to be used to send tcp packets on a connection. 815 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 816 * use for this function is in keepalives, which use tcp_respond. 817 */ 818 struct tcptemp * 819 tcpip_maketemplate(struct inpcb *inp) 820 { 821 struct tcptemp *t; 822 823 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 824 if (t == NULL) 825 return (NULL); 826 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 827 return (t); 828 } 829 830 /* 831 * Send a single message to the TCP at address specified by 832 * the given TCP/IP header. If m == NULL, then we make a copy 833 * of the tcpiphdr at th and send directly to the addressed host. 834 * This is used to force keep alive messages out using the TCP 835 * template for a connection. If flags are given then we send 836 * a message back to the TCP which originated the segment th, 837 * and discard the mbuf containing it and any other attached mbufs. 838 * 839 * In any case the ack and sequence number of the transmitted 840 * segment are as specified by the parameters. 841 * 842 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 843 */ 844 void 845 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 846 tcp_seq ack, tcp_seq seq, int flags) 847 { 848 int tlen; 849 int win = 0; 850 struct ip *ip; 851 struct tcphdr *nth; 852 #ifdef INET6 853 struct ip6_hdr *ip6; 854 int isipv6; 855 #endif /* INET6 */ 856 int ipflags = 0; 857 struct inpcb *inp; 858 859 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 860 861 #ifdef INET6 862 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 863 ip6 = ipgen; 864 #endif /* INET6 */ 865 ip = ipgen; 866 867 if (tp != NULL) { 868 inp = tp->t_inpcb; 869 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 870 INP_WLOCK_ASSERT(inp); 871 } else 872 inp = NULL; 873 874 if (tp != NULL) { 875 if (!(flags & TH_RST)) { 876 win = sbspace(&inp->inp_socket->so_rcv); 877 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 878 win = (long)TCP_MAXWIN << tp->rcv_scale; 879 } 880 } 881 if (m == NULL) { 882 m = m_gethdr(M_NOWAIT, MT_DATA); 883 if (m == NULL) 884 return; 885 tlen = 0; 886 m->m_data += max_linkhdr; 887 #ifdef INET6 888 if (isipv6) { 889 bcopy((caddr_t)ip6, mtod(m, caddr_t), 890 sizeof(struct ip6_hdr)); 891 ip6 = mtod(m, struct ip6_hdr *); 892 nth = (struct tcphdr *)(ip6 + 1); 893 } else 894 #endif /* INET6 */ 895 { 896 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 897 ip = mtod(m, struct ip *); 898 nth = (struct tcphdr *)(ip + 1); 899 } 900 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 901 flags = TH_ACK; 902 } else { 903 /* 904 * reuse the mbuf. 905 * XXX MRT We inherrit the FIB, which is lucky. 906 */ 907 m_freem(m->m_next); 908 m->m_next = NULL; 909 m->m_data = (caddr_t)ipgen; 910 /* m_len is set later */ 911 tlen = 0; 912 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 913 #ifdef INET6 914 if (isipv6) { 915 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 916 nth = (struct tcphdr *)(ip6 + 1); 917 } else 918 #endif /* INET6 */ 919 { 920 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 921 nth = (struct tcphdr *)(ip + 1); 922 } 923 if (th != nth) { 924 /* 925 * this is usually a case when an extension header 926 * exists between the IPv6 header and the 927 * TCP header. 928 */ 929 nth->th_sport = th->th_sport; 930 nth->th_dport = th->th_dport; 931 } 932 xchg(nth->th_dport, nth->th_sport, uint16_t); 933 #undef xchg 934 } 935 #ifdef INET6 936 if (isipv6) { 937 ip6->ip6_flow = 0; 938 ip6->ip6_vfc = IPV6_VERSION; 939 ip6->ip6_nxt = IPPROTO_TCP; 940 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 941 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 942 } 943 #endif 944 #if defined(INET) && defined(INET6) 945 else 946 #endif 947 #ifdef INET 948 { 949 tlen += sizeof (struct tcpiphdr); 950 ip->ip_len = htons(tlen); 951 ip->ip_ttl = V_ip_defttl; 952 if (V_path_mtu_discovery) 953 ip->ip_off |= htons(IP_DF); 954 } 955 #endif 956 m->m_len = tlen; 957 m->m_pkthdr.len = tlen; 958 m->m_pkthdr.rcvif = NULL; 959 #ifdef MAC 960 if (inp != NULL) { 961 /* 962 * Packet is associated with a socket, so allow the 963 * label of the response to reflect the socket label. 964 */ 965 INP_WLOCK_ASSERT(inp); 966 mac_inpcb_create_mbuf(inp, m); 967 } else { 968 /* 969 * Packet is not associated with a socket, so possibly 970 * update the label in place. 971 */ 972 mac_netinet_tcp_reply(m); 973 } 974 #endif 975 nth->th_seq = htonl(seq); 976 nth->th_ack = htonl(ack); 977 nth->th_x2 = 0; 978 nth->th_off = sizeof (struct tcphdr) >> 2; 979 nth->th_flags = flags; 980 if (tp != NULL) 981 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 982 else 983 nth->th_win = htons((u_short)win); 984 nth->th_urp = 0; 985 986 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 987 #ifdef INET6 988 if (isipv6) { 989 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 990 nth->th_sum = in6_cksum_pseudo(ip6, 991 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 992 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 993 NULL, NULL); 994 } 995 #endif /* INET6 */ 996 #if defined(INET6) && defined(INET) 997 else 998 #endif 999 #ifdef INET 1000 { 1001 m->m_pkthdr.csum_flags = CSUM_TCP; 1002 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1003 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1004 } 1005 #endif /* INET */ 1006 #ifdef TCPDEBUG 1007 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1008 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1009 #endif 1010 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *)); 1011 if (flags & TH_RST) 1012 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1013 tp, nth); 1014 1015 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1016 #ifdef INET6 1017 if (isipv6) 1018 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 1019 #endif /* INET6 */ 1020 #if defined(INET) && defined(INET6) 1021 else 1022 #endif 1023 #ifdef INET 1024 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 1025 #endif 1026 } 1027 1028 /* 1029 * Create a new TCP control block, making an 1030 * empty reassembly queue and hooking it to the argument 1031 * protocol control block. The `inp' parameter must have 1032 * come from the zone allocator set up in tcp_init(). 1033 */ 1034 struct tcpcb * 1035 tcp_newtcpcb(struct inpcb *inp) 1036 { 1037 struct tcpcb_mem *tm; 1038 struct tcpcb *tp; 1039 #ifdef INET6 1040 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1041 #endif /* INET6 */ 1042 1043 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1044 if (tm == NULL) 1045 return (NULL); 1046 tp = &tm->tcb; 1047 1048 /* Initialise cc_var struct for this tcpcb. */ 1049 tp->ccv = &tm->ccv; 1050 tp->ccv->type = IPPROTO_TCP; 1051 tp->ccv->ccvc.tcp = tp; 1052 rw_rlock(&tcp_function_lock); 1053 tp->t_fb = tcp_func_set_ptr; 1054 refcount_acquire(&tp->t_fb->tfb_refcnt); 1055 rw_runlock(&tcp_function_lock); 1056 if (tp->t_fb->tfb_tcp_fb_init) { 1057 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1058 } 1059 /* 1060 * Use the current system default CC algorithm. 1061 */ 1062 CC_LIST_RLOCK(); 1063 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1064 CC_ALGO(tp) = CC_DEFAULT(); 1065 CC_LIST_RUNLOCK(); 1066 1067 if (CC_ALGO(tp)->cb_init != NULL) 1068 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1069 if (tp->t_fb->tfb_tcp_fb_fini) 1070 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1071 refcount_release(&tp->t_fb->tfb_refcnt); 1072 uma_zfree(V_tcpcb_zone, tm); 1073 return (NULL); 1074 } 1075 1076 tp->osd = &tm->osd; 1077 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1078 if (tp->t_fb->tfb_tcp_fb_fini) 1079 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1080 refcount_release(&tp->t_fb->tfb_refcnt); 1081 uma_zfree(V_tcpcb_zone, tm); 1082 return (NULL); 1083 } 1084 1085 #ifdef VIMAGE 1086 tp->t_vnet = inp->inp_vnet; 1087 #endif 1088 tp->t_timers = &tm->tt; 1089 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1090 tp->t_maxseg = tp->t_maxopd = 1091 #ifdef INET6 1092 isipv6 ? V_tcp_v6mssdflt : 1093 #endif /* INET6 */ 1094 V_tcp_mssdflt; 1095 1096 /* Set up our timeouts. */ 1097 callout_init(&tp->t_timers->tt_rexmt, 1); 1098 callout_init(&tp->t_timers->tt_persist, 1); 1099 callout_init(&tp->t_timers->tt_keep, 1); 1100 callout_init(&tp->t_timers->tt_2msl, 1); 1101 callout_init(&tp->t_timers->tt_delack, 1); 1102 1103 if (V_tcp_do_rfc1323) 1104 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1105 if (V_tcp_do_sack) 1106 tp->t_flags |= TF_SACK_PERMIT; 1107 TAILQ_INIT(&tp->snd_holes); 1108 /* 1109 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1110 * is called. 1111 */ 1112 in_pcbref(inp); /* Reference for tcpcb */ 1113 tp->t_inpcb = inp; 1114 1115 /* 1116 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1117 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1118 * reasonable initial retransmit time. 1119 */ 1120 tp->t_srtt = TCPTV_SRTTBASE; 1121 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1122 tp->t_rttmin = tcp_rexmit_min; 1123 tp->t_rxtcur = TCPTV_RTOBASE; 1124 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1125 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1126 tp->t_rcvtime = ticks; 1127 /* 1128 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1129 * because the socket may be bound to an IPv6 wildcard address, 1130 * which may match an IPv4-mapped IPv6 address. 1131 */ 1132 inp->inp_ip_ttl = V_ip_defttl; 1133 inp->inp_ppcb = tp; 1134 #ifdef TCPPCAP 1135 /* 1136 * Init the TCP PCAP queues. 1137 */ 1138 tcp_pcap_tcpcb_init(tp); 1139 #endif 1140 return (tp); /* XXX */ 1141 } 1142 1143 /* 1144 * Switch the congestion control algorithm back to NewReno for any active 1145 * control blocks using an algorithm which is about to go away. 1146 * This ensures the CC framework can allow the unload to proceed without leaving 1147 * any dangling pointers which would trigger a panic. 1148 * Returning non-zero would inform the CC framework that something went wrong 1149 * and it would be unsafe to allow the unload to proceed. However, there is no 1150 * way for this to occur with this implementation so we always return zero. 1151 */ 1152 int 1153 tcp_ccalgounload(struct cc_algo *unload_algo) 1154 { 1155 struct cc_algo *tmpalgo; 1156 struct inpcb *inp; 1157 struct tcpcb *tp; 1158 VNET_ITERATOR_DECL(vnet_iter); 1159 1160 /* 1161 * Check all active control blocks across all network stacks and change 1162 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1163 * requires cleanup code to be run, call it. 1164 */ 1165 VNET_LIST_RLOCK(); 1166 VNET_FOREACH(vnet_iter) { 1167 CURVNET_SET(vnet_iter); 1168 INP_INFO_WLOCK(&V_tcbinfo); 1169 /* 1170 * New connections already part way through being initialised 1171 * with the CC algo we're removing will not race with this code 1172 * because the INP_INFO_WLOCK is held during initialisation. We 1173 * therefore don't enter the loop below until the connection 1174 * list has stabilised. 1175 */ 1176 LIST_FOREACH(inp, &V_tcb, inp_list) { 1177 INP_WLOCK(inp); 1178 /* Important to skip tcptw structs. */ 1179 if (!(inp->inp_flags & INP_TIMEWAIT) && 1180 (tp = intotcpcb(inp)) != NULL) { 1181 /* 1182 * By holding INP_WLOCK here, we are assured 1183 * that the connection is not currently 1184 * executing inside the CC module's functions 1185 * i.e. it is safe to make the switch back to 1186 * NewReno. 1187 */ 1188 if (CC_ALGO(tp) == unload_algo) { 1189 tmpalgo = CC_ALGO(tp); 1190 /* NewReno does not require any init. */ 1191 CC_ALGO(tp) = &newreno_cc_algo; 1192 if (tmpalgo->cb_destroy != NULL) 1193 tmpalgo->cb_destroy(tp->ccv); 1194 } 1195 } 1196 INP_WUNLOCK(inp); 1197 } 1198 INP_INFO_WUNLOCK(&V_tcbinfo); 1199 CURVNET_RESTORE(); 1200 } 1201 VNET_LIST_RUNLOCK(); 1202 1203 return (0); 1204 } 1205 1206 /* 1207 * Drop a TCP connection, reporting 1208 * the specified error. If connection is synchronized, 1209 * then send a RST to peer. 1210 */ 1211 struct tcpcb * 1212 tcp_drop(struct tcpcb *tp, int errno) 1213 { 1214 struct socket *so = tp->t_inpcb->inp_socket; 1215 1216 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1217 INP_WLOCK_ASSERT(tp->t_inpcb); 1218 1219 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1220 tcp_state_change(tp, TCPS_CLOSED); 1221 (void) tp->t_fb->tfb_tcp_output(tp); 1222 TCPSTAT_INC(tcps_drops); 1223 } else 1224 TCPSTAT_INC(tcps_conndrops); 1225 if (errno == ETIMEDOUT && tp->t_softerror) 1226 errno = tp->t_softerror; 1227 so->so_error = errno; 1228 return (tcp_close(tp)); 1229 } 1230 1231 void 1232 tcp_discardcb(struct tcpcb *tp) 1233 { 1234 struct inpcb *inp = tp->t_inpcb; 1235 struct socket *so = inp->inp_socket; 1236 #ifdef INET6 1237 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1238 #endif /* INET6 */ 1239 int released; 1240 1241 INP_WLOCK_ASSERT(inp); 1242 1243 /* 1244 * Make sure that all of our timers are stopped before we delete the 1245 * PCB. 1246 * 1247 * If stopping a timer fails, we schedule a discard function in same 1248 * callout, and the last discard function called will take care of 1249 * deleting the tcpcb. 1250 */ 1251 tcp_timer_stop(tp, TT_REXMT); 1252 tcp_timer_stop(tp, TT_PERSIST); 1253 tcp_timer_stop(tp, TT_KEEP); 1254 tcp_timer_stop(tp, TT_2MSL); 1255 tcp_timer_stop(tp, TT_DELACK); 1256 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1257 /* Call the stop-all function of the methods */ 1258 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1259 } 1260 1261 /* 1262 * If we got enough samples through the srtt filter, 1263 * save the rtt and rttvar in the routing entry. 1264 * 'Enough' is arbitrarily defined as 4 rtt samples. 1265 * 4 samples is enough for the srtt filter to converge 1266 * to within enough % of the correct value; fewer samples 1267 * and we could save a bogus rtt. The danger is not high 1268 * as tcp quickly recovers from everything. 1269 * XXX: Works very well but needs some more statistics! 1270 */ 1271 if (tp->t_rttupdated >= 4) { 1272 struct hc_metrics_lite metrics; 1273 u_long ssthresh; 1274 1275 bzero(&metrics, sizeof(metrics)); 1276 /* 1277 * Update the ssthresh always when the conditions below 1278 * are satisfied. This gives us better new start value 1279 * for the congestion avoidance for new connections. 1280 * ssthresh is only set if packet loss occured on a session. 1281 * 1282 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1283 * being torn down. Ideally this code would not use 'so'. 1284 */ 1285 ssthresh = tp->snd_ssthresh; 1286 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1287 /* 1288 * convert the limit from user data bytes to 1289 * packets then to packet data bytes. 1290 */ 1291 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1292 if (ssthresh < 2) 1293 ssthresh = 2; 1294 ssthresh *= (u_long)(tp->t_maxseg + 1295 #ifdef INET6 1296 (isipv6 ? sizeof (struct ip6_hdr) + 1297 sizeof (struct tcphdr) : 1298 #endif 1299 sizeof (struct tcpiphdr) 1300 #ifdef INET6 1301 ) 1302 #endif 1303 ); 1304 } else 1305 ssthresh = 0; 1306 metrics.rmx_ssthresh = ssthresh; 1307 1308 metrics.rmx_rtt = tp->t_srtt; 1309 metrics.rmx_rttvar = tp->t_rttvar; 1310 metrics.rmx_cwnd = tp->snd_cwnd; 1311 metrics.rmx_sendpipe = 0; 1312 metrics.rmx_recvpipe = 0; 1313 1314 tcp_hc_update(&inp->inp_inc, &metrics); 1315 } 1316 1317 /* free the reassembly queue, if any */ 1318 tcp_reass_flush(tp); 1319 1320 #ifdef TCP_OFFLOAD 1321 /* Disconnect offload device, if any. */ 1322 if (tp->t_flags & TF_TOE) 1323 tcp_offload_detach(tp); 1324 #endif 1325 1326 tcp_free_sackholes(tp); 1327 1328 #ifdef TCPPCAP 1329 /* Free the TCP PCAP queues. */ 1330 tcp_pcap_drain(&(tp->t_inpkts)); 1331 tcp_pcap_drain(&(tp->t_outpkts)); 1332 #endif 1333 1334 /* Allow the CC algorithm to clean up after itself. */ 1335 if (CC_ALGO(tp)->cb_destroy != NULL) 1336 CC_ALGO(tp)->cb_destroy(tp->ccv); 1337 1338 khelp_destroy_osd(tp->osd); 1339 1340 CC_ALGO(tp) = NULL; 1341 inp->inp_ppcb = NULL; 1342 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1343 /* We own the last reference on tcpcb, let's free it. */ 1344 if ((tp->t_fb->tfb_tcp_timers_left) && 1345 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1346 /* Some fb timers left running! */ 1347 return; 1348 } 1349 if (tp->t_fb->tfb_tcp_fb_fini) 1350 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1351 refcount_release(&tp->t_fb->tfb_refcnt); 1352 tp->t_inpcb = NULL; 1353 uma_zfree(V_tcpcb_zone, tp); 1354 released = in_pcbrele_wlocked(inp); 1355 KASSERT(!released, ("%s: inp %p should not have been released " 1356 "here", __func__, inp)); 1357 } 1358 } 1359 1360 void 1361 tcp_timer_2msl_discard(void *xtp) 1362 { 1363 1364 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1365 } 1366 1367 void 1368 tcp_timer_keep_discard(void *xtp) 1369 { 1370 1371 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1372 } 1373 1374 void 1375 tcp_timer_persist_discard(void *xtp) 1376 { 1377 1378 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1379 } 1380 1381 void 1382 tcp_timer_rexmt_discard(void *xtp) 1383 { 1384 1385 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1386 } 1387 1388 void 1389 tcp_timer_delack_discard(void *xtp) 1390 { 1391 1392 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1393 } 1394 1395 void 1396 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1397 { 1398 struct inpcb *inp; 1399 1400 CURVNET_SET(tp->t_vnet); 1401 INP_INFO_RLOCK(&V_tcbinfo); 1402 inp = tp->t_inpcb; 1403 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1404 __func__, tp)); 1405 INP_WLOCK(inp); 1406 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1407 ("%s: tcpcb has to be stopped here", __func__)); 1408 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1409 ("%s: discard callout should be running", __func__)); 1410 tp->t_timers->tt_flags &= ~timer_type; 1411 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1412 /* We own the last reference on this tcpcb, let's free it. */ 1413 if ((tp->t_fb->tfb_tcp_timers_left) && 1414 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1415 /* Some fb timers left running! */ 1416 goto leave; 1417 } 1418 if (tp->t_fb->tfb_tcp_fb_fini) 1419 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1420 refcount_release(&tp->t_fb->tfb_refcnt); 1421 tp->t_inpcb = NULL; 1422 uma_zfree(V_tcpcb_zone, tp); 1423 if (in_pcbrele_wlocked(inp)) { 1424 INP_INFO_RUNLOCK(&V_tcbinfo); 1425 CURVNET_RESTORE(); 1426 return; 1427 } 1428 } 1429 leave: 1430 INP_WUNLOCK(inp); 1431 INP_INFO_RUNLOCK(&V_tcbinfo); 1432 CURVNET_RESTORE(); 1433 } 1434 1435 /* 1436 * Attempt to close a TCP control block, marking it as dropped, and freeing 1437 * the socket if we hold the only reference. 1438 */ 1439 struct tcpcb * 1440 tcp_close(struct tcpcb *tp) 1441 { 1442 struct inpcb *inp = tp->t_inpcb; 1443 struct socket *so; 1444 1445 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1446 INP_WLOCK_ASSERT(inp); 1447 1448 #ifdef TCP_OFFLOAD 1449 if (tp->t_state == TCPS_LISTEN) 1450 tcp_offload_listen_stop(tp); 1451 #endif 1452 #ifdef TCP_RFC7413 1453 /* 1454 * This releases the TFO pending counter resource for TFO listen 1455 * sockets as well as passively-created TFO sockets that transition 1456 * from SYN_RECEIVED to CLOSED. 1457 */ 1458 if (tp->t_tfo_pending) { 1459 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1460 tp->t_tfo_pending = NULL; 1461 } 1462 #endif 1463 in_pcbdrop(inp); 1464 TCPSTAT_INC(tcps_closed); 1465 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1466 so = inp->inp_socket; 1467 soisdisconnected(so); 1468 if (inp->inp_flags & INP_SOCKREF) { 1469 KASSERT(so->so_state & SS_PROTOREF, 1470 ("tcp_close: !SS_PROTOREF")); 1471 inp->inp_flags &= ~INP_SOCKREF; 1472 INP_WUNLOCK(inp); 1473 ACCEPT_LOCK(); 1474 SOCK_LOCK(so); 1475 so->so_state &= ~SS_PROTOREF; 1476 sofree(so); 1477 return (NULL); 1478 } 1479 return (tp); 1480 } 1481 1482 void 1483 tcp_drain(void) 1484 { 1485 VNET_ITERATOR_DECL(vnet_iter); 1486 1487 if (!do_tcpdrain) 1488 return; 1489 1490 VNET_LIST_RLOCK_NOSLEEP(); 1491 VNET_FOREACH(vnet_iter) { 1492 CURVNET_SET(vnet_iter); 1493 struct inpcb *inpb; 1494 struct tcpcb *tcpb; 1495 1496 /* 1497 * Walk the tcpbs, if existing, and flush the reassembly queue, 1498 * if there is one... 1499 * XXX: The "Net/3" implementation doesn't imply that the TCP 1500 * reassembly queue should be flushed, but in a situation 1501 * where we're really low on mbufs, this is potentially 1502 * useful. 1503 */ 1504 INP_INFO_WLOCK(&V_tcbinfo); 1505 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1506 if (inpb->inp_flags & INP_TIMEWAIT) 1507 continue; 1508 INP_WLOCK(inpb); 1509 if ((tcpb = intotcpcb(inpb)) != NULL) { 1510 tcp_reass_flush(tcpb); 1511 tcp_clean_sackreport(tcpb); 1512 } 1513 INP_WUNLOCK(inpb); 1514 } 1515 INP_INFO_WUNLOCK(&V_tcbinfo); 1516 CURVNET_RESTORE(); 1517 } 1518 VNET_LIST_RUNLOCK_NOSLEEP(); 1519 } 1520 1521 /* 1522 * Notify a tcp user of an asynchronous error; 1523 * store error as soft error, but wake up user 1524 * (for now, won't do anything until can select for soft error). 1525 * 1526 * Do not wake up user since there currently is no mechanism for 1527 * reporting soft errors (yet - a kqueue filter may be added). 1528 */ 1529 static struct inpcb * 1530 tcp_notify(struct inpcb *inp, int error) 1531 { 1532 struct tcpcb *tp; 1533 1534 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1535 INP_WLOCK_ASSERT(inp); 1536 1537 if ((inp->inp_flags & INP_TIMEWAIT) || 1538 (inp->inp_flags & INP_DROPPED)) 1539 return (inp); 1540 1541 tp = intotcpcb(inp); 1542 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1543 1544 /* 1545 * Ignore some errors if we are hooked up. 1546 * If connection hasn't completed, has retransmitted several times, 1547 * and receives a second error, give up now. This is better 1548 * than waiting a long time to establish a connection that 1549 * can never complete. 1550 */ 1551 if (tp->t_state == TCPS_ESTABLISHED && 1552 (error == EHOSTUNREACH || error == ENETUNREACH || 1553 error == EHOSTDOWN)) { 1554 return (inp); 1555 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1556 tp->t_softerror) { 1557 tp = tcp_drop(tp, error); 1558 if (tp != NULL) 1559 return (inp); 1560 else 1561 return (NULL); 1562 } else { 1563 tp->t_softerror = error; 1564 return (inp); 1565 } 1566 #if 0 1567 wakeup( &so->so_timeo); 1568 sorwakeup(so); 1569 sowwakeup(so); 1570 #endif 1571 } 1572 1573 static int 1574 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1575 { 1576 int error, i, m, n, pcb_count; 1577 struct inpcb *inp, **inp_list; 1578 inp_gen_t gencnt; 1579 struct xinpgen xig; 1580 1581 /* 1582 * The process of preparing the TCB list is too time-consuming and 1583 * resource-intensive to repeat twice on every request. 1584 */ 1585 if (req->oldptr == NULL) { 1586 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1587 n += imax(n / 8, 10); 1588 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1589 return (0); 1590 } 1591 1592 if (req->newptr != NULL) 1593 return (EPERM); 1594 1595 /* 1596 * OK, now we're committed to doing something. 1597 */ 1598 INP_LIST_RLOCK(&V_tcbinfo); 1599 gencnt = V_tcbinfo.ipi_gencnt; 1600 n = V_tcbinfo.ipi_count; 1601 INP_LIST_RUNLOCK(&V_tcbinfo); 1602 1603 m = syncache_pcbcount(); 1604 1605 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1606 + (n + m) * sizeof(struct xtcpcb)); 1607 if (error != 0) 1608 return (error); 1609 1610 xig.xig_len = sizeof xig; 1611 xig.xig_count = n + m; 1612 xig.xig_gen = gencnt; 1613 xig.xig_sogen = so_gencnt; 1614 error = SYSCTL_OUT(req, &xig, sizeof xig); 1615 if (error) 1616 return (error); 1617 1618 error = syncache_pcblist(req, m, &pcb_count); 1619 if (error) 1620 return (error); 1621 1622 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1623 if (inp_list == NULL) 1624 return (ENOMEM); 1625 1626 INP_INFO_WLOCK(&V_tcbinfo); 1627 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1628 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1629 INP_WLOCK(inp); 1630 if (inp->inp_gencnt <= gencnt) { 1631 /* 1632 * XXX: This use of cr_cansee(), introduced with 1633 * TCP state changes, is not quite right, but for 1634 * now, better than nothing. 1635 */ 1636 if (inp->inp_flags & INP_TIMEWAIT) { 1637 if (intotw(inp) != NULL) 1638 error = cr_cansee(req->td->td_ucred, 1639 intotw(inp)->tw_cred); 1640 else 1641 error = EINVAL; /* Skip this inp. */ 1642 } else 1643 error = cr_canseeinpcb(req->td->td_ucred, inp); 1644 if (error == 0) { 1645 in_pcbref(inp); 1646 inp_list[i++] = inp; 1647 } 1648 } 1649 INP_WUNLOCK(inp); 1650 } 1651 INP_INFO_WUNLOCK(&V_tcbinfo); 1652 n = i; 1653 1654 error = 0; 1655 for (i = 0; i < n; i++) { 1656 inp = inp_list[i]; 1657 INP_RLOCK(inp); 1658 if (inp->inp_gencnt <= gencnt) { 1659 struct xtcpcb xt; 1660 void *inp_ppcb; 1661 1662 bzero(&xt, sizeof(xt)); 1663 xt.xt_len = sizeof xt; 1664 /* XXX should avoid extra copy */ 1665 bcopy(inp, &xt.xt_inp, sizeof *inp); 1666 inp_ppcb = inp->inp_ppcb; 1667 if (inp_ppcb == NULL) 1668 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1669 else if (inp->inp_flags & INP_TIMEWAIT) { 1670 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1671 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1672 } else { 1673 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1674 if (xt.xt_tp.t_timers) 1675 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1676 } 1677 if (inp->inp_socket != NULL) 1678 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1679 else { 1680 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1681 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1682 } 1683 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1684 INP_RUNLOCK(inp); 1685 error = SYSCTL_OUT(req, &xt, sizeof xt); 1686 } else 1687 INP_RUNLOCK(inp); 1688 } 1689 INP_INFO_RLOCK(&V_tcbinfo); 1690 for (i = 0; i < n; i++) { 1691 inp = inp_list[i]; 1692 INP_RLOCK(inp); 1693 if (!in_pcbrele_rlocked(inp)) 1694 INP_RUNLOCK(inp); 1695 } 1696 INP_INFO_RUNLOCK(&V_tcbinfo); 1697 1698 if (!error) { 1699 /* 1700 * Give the user an updated idea of our state. 1701 * If the generation differs from what we told 1702 * her before, she knows that something happened 1703 * while we were processing this request, and it 1704 * might be necessary to retry. 1705 */ 1706 INP_LIST_RLOCK(&V_tcbinfo); 1707 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1708 xig.xig_sogen = so_gencnt; 1709 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1710 INP_LIST_RUNLOCK(&V_tcbinfo); 1711 error = SYSCTL_OUT(req, &xig, sizeof xig); 1712 } 1713 free(inp_list, M_TEMP); 1714 return (error); 1715 } 1716 1717 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1718 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1719 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1720 1721 #ifdef INET 1722 static int 1723 tcp_getcred(SYSCTL_HANDLER_ARGS) 1724 { 1725 struct xucred xuc; 1726 struct sockaddr_in addrs[2]; 1727 struct inpcb *inp; 1728 int error; 1729 1730 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1731 if (error) 1732 return (error); 1733 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1734 if (error) 1735 return (error); 1736 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1737 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1738 if (inp != NULL) { 1739 if (inp->inp_socket == NULL) 1740 error = ENOENT; 1741 if (error == 0) 1742 error = cr_canseeinpcb(req->td->td_ucred, inp); 1743 if (error == 0) 1744 cru2x(inp->inp_cred, &xuc); 1745 INP_RUNLOCK(inp); 1746 } else 1747 error = ENOENT; 1748 if (error == 0) 1749 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1750 return (error); 1751 } 1752 1753 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1754 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1755 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1756 #endif /* INET */ 1757 1758 #ifdef INET6 1759 static int 1760 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1761 { 1762 struct xucred xuc; 1763 struct sockaddr_in6 addrs[2]; 1764 struct inpcb *inp; 1765 int error; 1766 #ifdef INET 1767 int mapped = 0; 1768 #endif 1769 1770 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1771 if (error) 1772 return (error); 1773 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1774 if (error) 1775 return (error); 1776 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1777 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1778 return (error); 1779 } 1780 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1781 #ifdef INET 1782 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1783 mapped = 1; 1784 else 1785 #endif 1786 return (EINVAL); 1787 } 1788 1789 #ifdef INET 1790 if (mapped == 1) 1791 inp = in_pcblookup(&V_tcbinfo, 1792 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1793 addrs[1].sin6_port, 1794 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1795 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1796 else 1797 #endif 1798 inp = in6_pcblookup(&V_tcbinfo, 1799 &addrs[1].sin6_addr, addrs[1].sin6_port, 1800 &addrs[0].sin6_addr, addrs[0].sin6_port, 1801 INPLOOKUP_RLOCKPCB, NULL); 1802 if (inp != NULL) { 1803 if (inp->inp_socket == NULL) 1804 error = ENOENT; 1805 if (error == 0) 1806 error = cr_canseeinpcb(req->td->td_ucred, inp); 1807 if (error == 0) 1808 cru2x(inp->inp_cred, &xuc); 1809 INP_RUNLOCK(inp); 1810 } else 1811 error = ENOENT; 1812 if (error == 0) 1813 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1814 return (error); 1815 } 1816 1817 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1818 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1819 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1820 #endif /* INET6 */ 1821 1822 1823 #ifdef INET 1824 void 1825 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1826 { 1827 struct ip *ip = vip; 1828 struct tcphdr *th; 1829 struct in_addr faddr; 1830 struct inpcb *inp; 1831 struct tcpcb *tp; 1832 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1833 struct icmp *icp; 1834 struct in_conninfo inc; 1835 tcp_seq icmp_tcp_seq; 1836 int mtu; 1837 1838 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1839 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1840 return; 1841 1842 if (cmd == PRC_MSGSIZE) 1843 notify = tcp_mtudisc_notify; 1844 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1845 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1846 notify = tcp_drop_syn_sent; 1847 /* 1848 * Redirects don't need to be handled up here. 1849 */ 1850 else if (PRC_IS_REDIRECT(cmd)) 1851 return; 1852 /* 1853 * Hostdead is ugly because it goes linearly through all PCBs. 1854 * XXX: We never get this from ICMP, otherwise it makes an 1855 * excellent DoS attack on machines with many connections. 1856 */ 1857 else if (cmd == PRC_HOSTDEAD) 1858 ip = NULL; 1859 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1860 return; 1861 1862 if (ip == NULL) { 1863 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1864 return; 1865 } 1866 1867 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1868 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1869 INP_INFO_RLOCK(&V_tcbinfo); 1870 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1871 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1872 if (inp != NULL) { 1873 if (!(inp->inp_flags & INP_TIMEWAIT) && 1874 !(inp->inp_flags & INP_DROPPED) && 1875 !(inp->inp_socket == NULL)) { 1876 icmp_tcp_seq = ntohl(th->th_seq); 1877 tp = intotcpcb(inp); 1878 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1879 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1880 if (cmd == PRC_MSGSIZE) { 1881 /* 1882 * MTU discovery: 1883 * If we got a needfrag set the MTU 1884 * in the route to the suggested new 1885 * value (if given) and then notify. 1886 */ 1887 mtu = ntohs(icp->icmp_nextmtu); 1888 /* 1889 * If no alternative MTU was 1890 * proposed, try the next smaller 1891 * one. 1892 */ 1893 if (!mtu) 1894 mtu = ip_next_mtu( 1895 ntohs(ip->ip_len), 1); 1896 if (mtu < V_tcp_minmss + 1897 sizeof(struct tcpiphdr)) 1898 mtu = V_tcp_minmss + 1899 sizeof(struct tcpiphdr); 1900 /* 1901 * Only process the offered MTU if it 1902 * is smaller than the current one. 1903 */ 1904 if (mtu < tp->t_maxopd + 1905 sizeof(struct tcpiphdr)) { 1906 bzero(&inc, sizeof(inc)); 1907 inc.inc_faddr = faddr; 1908 inc.inc_fibnum = 1909 inp->inp_inc.inc_fibnum; 1910 tcp_hc_updatemtu(&inc, mtu); 1911 tcp_mtudisc(inp, mtu); 1912 } 1913 } else 1914 inp = (*notify)(inp, 1915 inetctlerrmap[cmd]); 1916 } 1917 } 1918 if (inp != NULL) 1919 INP_WUNLOCK(inp); 1920 } else { 1921 bzero(&inc, sizeof(inc)); 1922 inc.inc_fport = th->th_dport; 1923 inc.inc_lport = th->th_sport; 1924 inc.inc_faddr = faddr; 1925 inc.inc_laddr = ip->ip_src; 1926 syncache_unreach(&inc, th); 1927 } 1928 INP_INFO_RUNLOCK(&V_tcbinfo); 1929 } 1930 #endif /* INET */ 1931 1932 #ifdef INET6 1933 void 1934 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1935 { 1936 struct tcphdr th; 1937 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1938 struct ip6_hdr *ip6; 1939 struct mbuf *m; 1940 struct ip6ctlparam *ip6cp = NULL; 1941 const struct sockaddr_in6 *sa6_src = NULL; 1942 int off; 1943 struct tcp_portonly { 1944 u_int16_t th_sport; 1945 u_int16_t th_dport; 1946 } *thp; 1947 1948 if (sa->sa_family != AF_INET6 || 1949 sa->sa_len != sizeof(struct sockaddr_in6)) 1950 return; 1951 1952 if (cmd == PRC_MSGSIZE) 1953 notify = tcp_mtudisc_notify; 1954 else if (!PRC_IS_REDIRECT(cmd) && 1955 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1956 return; 1957 1958 /* if the parameter is from icmp6, decode it. */ 1959 if (d != NULL) { 1960 ip6cp = (struct ip6ctlparam *)d; 1961 m = ip6cp->ip6c_m; 1962 ip6 = ip6cp->ip6c_ip6; 1963 off = ip6cp->ip6c_off; 1964 sa6_src = ip6cp->ip6c_src; 1965 } else { 1966 m = NULL; 1967 ip6 = NULL; 1968 off = 0; /* fool gcc */ 1969 sa6_src = &sa6_any; 1970 } 1971 1972 if (ip6 != NULL) { 1973 struct in_conninfo inc; 1974 /* 1975 * XXX: We assume that when IPV6 is non NULL, 1976 * M and OFF are valid. 1977 */ 1978 1979 /* check if we can safely examine src and dst ports */ 1980 if (m->m_pkthdr.len < off + sizeof(*thp)) 1981 return; 1982 1983 bzero(&th, sizeof(th)); 1984 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1985 1986 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1987 (struct sockaddr *)ip6cp->ip6c_src, 1988 th.th_sport, cmd, NULL, notify); 1989 1990 bzero(&inc, sizeof(inc)); 1991 inc.inc_fport = th.th_dport; 1992 inc.inc_lport = th.th_sport; 1993 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1994 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1995 inc.inc_flags |= INC_ISIPV6; 1996 INP_INFO_RLOCK(&V_tcbinfo); 1997 syncache_unreach(&inc, &th); 1998 INP_INFO_RUNLOCK(&V_tcbinfo); 1999 } else 2000 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 2001 0, cmd, NULL, notify); 2002 } 2003 #endif /* INET6 */ 2004 2005 2006 /* 2007 * Following is where TCP initial sequence number generation occurs. 2008 * 2009 * There are two places where we must use initial sequence numbers: 2010 * 1. In SYN-ACK packets. 2011 * 2. In SYN packets. 2012 * 2013 * All ISNs for SYN-ACK packets are generated by the syncache. See 2014 * tcp_syncache.c for details. 2015 * 2016 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2017 * depends on this property. In addition, these ISNs should be 2018 * unguessable so as to prevent connection hijacking. To satisfy 2019 * the requirements of this situation, the algorithm outlined in 2020 * RFC 1948 is used, with only small modifications. 2021 * 2022 * Implementation details: 2023 * 2024 * Time is based off the system timer, and is corrected so that it 2025 * increases by one megabyte per second. This allows for proper 2026 * recycling on high speed LANs while still leaving over an hour 2027 * before rollover. 2028 * 2029 * As reading the *exact* system time is too expensive to be done 2030 * whenever setting up a TCP connection, we increment the time 2031 * offset in two ways. First, a small random positive increment 2032 * is added to isn_offset for each connection that is set up. 2033 * Second, the function tcp_isn_tick fires once per clock tick 2034 * and increments isn_offset as necessary so that sequence numbers 2035 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2036 * random positive increments serve only to ensure that the same 2037 * exact sequence number is never sent out twice (as could otherwise 2038 * happen when a port is recycled in less than the system tick 2039 * interval.) 2040 * 2041 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2042 * between seeding of isn_secret. This is normally set to zero, 2043 * as reseeding should not be necessary. 2044 * 2045 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2046 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2047 * general, this means holding an exclusive (write) lock. 2048 */ 2049 2050 #define ISN_BYTES_PER_SECOND 1048576 2051 #define ISN_STATIC_INCREMENT 4096 2052 #define ISN_RANDOM_INCREMENT (4096 - 1) 2053 2054 static VNET_DEFINE(u_char, isn_secret[32]); 2055 static VNET_DEFINE(int, isn_last); 2056 static VNET_DEFINE(int, isn_last_reseed); 2057 static VNET_DEFINE(u_int32_t, isn_offset); 2058 static VNET_DEFINE(u_int32_t, isn_offset_old); 2059 2060 #define V_isn_secret VNET(isn_secret) 2061 #define V_isn_last VNET(isn_last) 2062 #define V_isn_last_reseed VNET(isn_last_reseed) 2063 #define V_isn_offset VNET(isn_offset) 2064 #define V_isn_offset_old VNET(isn_offset_old) 2065 2066 tcp_seq 2067 tcp_new_isn(struct tcpcb *tp) 2068 { 2069 MD5_CTX isn_ctx; 2070 u_int32_t md5_buffer[4]; 2071 tcp_seq new_isn; 2072 u_int32_t projected_offset; 2073 2074 INP_WLOCK_ASSERT(tp->t_inpcb); 2075 2076 ISN_LOCK(); 2077 /* Seed if this is the first use, reseed if requested. */ 2078 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2079 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2080 < (u_int)ticks))) { 2081 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2082 V_isn_last_reseed = ticks; 2083 } 2084 2085 /* Compute the md5 hash and return the ISN. */ 2086 MD5Init(&isn_ctx); 2087 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2088 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2089 #ifdef INET6 2090 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2091 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2092 sizeof(struct in6_addr)); 2093 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2094 sizeof(struct in6_addr)); 2095 } else 2096 #endif 2097 { 2098 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2099 sizeof(struct in_addr)); 2100 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2101 sizeof(struct in_addr)); 2102 } 2103 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2104 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2105 new_isn = (tcp_seq) md5_buffer[0]; 2106 V_isn_offset += ISN_STATIC_INCREMENT + 2107 (arc4random() & ISN_RANDOM_INCREMENT); 2108 if (ticks != V_isn_last) { 2109 projected_offset = V_isn_offset_old + 2110 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2111 if (SEQ_GT(projected_offset, V_isn_offset)) 2112 V_isn_offset = projected_offset; 2113 V_isn_offset_old = V_isn_offset; 2114 V_isn_last = ticks; 2115 } 2116 new_isn += V_isn_offset; 2117 ISN_UNLOCK(); 2118 return (new_isn); 2119 } 2120 2121 /* 2122 * When a specific ICMP unreachable message is received and the 2123 * connection state is SYN-SENT, drop the connection. This behavior 2124 * is controlled by the icmp_may_rst sysctl. 2125 */ 2126 struct inpcb * 2127 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2128 { 2129 struct tcpcb *tp; 2130 2131 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2132 INP_WLOCK_ASSERT(inp); 2133 2134 if ((inp->inp_flags & INP_TIMEWAIT) || 2135 (inp->inp_flags & INP_DROPPED)) 2136 return (inp); 2137 2138 tp = intotcpcb(inp); 2139 if (tp->t_state != TCPS_SYN_SENT) 2140 return (inp); 2141 2142 tp = tcp_drop(tp, errno); 2143 if (tp != NULL) 2144 return (inp); 2145 else 2146 return (NULL); 2147 } 2148 2149 /* 2150 * When `need fragmentation' ICMP is received, update our idea of the MSS 2151 * based on the new value. Also nudge TCP to send something, since we 2152 * know the packet we just sent was dropped. 2153 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2154 */ 2155 static struct inpcb * 2156 tcp_mtudisc_notify(struct inpcb *inp, int error) 2157 { 2158 2159 tcp_mtudisc(inp, -1); 2160 return (inp); 2161 } 2162 2163 static void 2164 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2165 { 2166 struct tcpcb *tp; 2167 struct socket *so; 2168 2169 INP_WLOCK_ASSERT(inp); 2170 if ((inp->inp_flags & INP_TIMEWAIT) || 2171 (inp->inp_flags & INP_DROPPED)) 2172 return; 2173 2174 tp = intotcpcb(inp); 2175 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2176 2177 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2178 2179 so = inp->inp_socket; 2180 SOCKBUF_LOCK(&so->so_snd); 2181 /* If the mss is larger than the socket buffer, decrease the mss. */ 2182 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2183 tp->t_maxseg = so->so_snd.sb_hiwat; 2184 SOCKBUF_UNLOCK(&so->so_snd); 2185 2186 TCPSTAT_INC(tcps_mturesent); 2187 tp->t_rtttime = 0; 2188 tp->snd_nxt = tp->snd_una; 2189 tcp_free_sackholes(tp); 2190 tp->snd_recover = tp->snd_max; 2191 if (tp->t_flags & TF_SACK_PERMIT) 2192 EXIT_FASTRECOVERY(tp->t_flags); 2193 tp->t_fb->tfb_tcp_output(tp); 2194 } 2195 2196 #ifdef INET 2197 /* 2198 * Look-up the routing entry to the peer of this inpcb. If no route 2199 * is found and it cannot be allocated, then return 0. This routine 2200 * is called by TCP routines that access the rmx structure and by 2201 * tcp_mss_update to get the peer/interface MTU. 2202 */ 2203 u_long 2204 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2205 { 2206 struct route sro; 2207 struct sockaddr_in *dst; 2208 struct ifnet *ifp; 2209 u_long maxmtu = 0; 2210 2211 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2212 2213 bzero(&sro, sizeof(sro)); 2214 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2215 dst = (struct sockaddr_in *)&sro.ro_dst; 2216 dst->sin_family = AF_INET; 2217 dst->sin_len = sizeof(*dst); 2218 dst->sin_addr = inc->inc_faddr; 2219 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 2220 } 2221 if (sro.ro_rt != NULL) { 2222 ifp = sro.ro_rt->rt_ifp; 2223 if (sro.ro_rt->rt_mtu == 0) 2224 maxmtu = ifp->if_mtu; 2225 else 2226 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 2227 2228 /* Report additional interface capabilities. */ 2229 if (cap != NULL) { 2230 if (ifp->if_capenable & IFCAP_TSO4 && 2231 ifp->if_hwassist & CSUM_TSO) { 2232 cap->ifcap |= CSUM_TSO; 2233 cap->tsomax = ifp->if_hw_tsomax; 2234 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2235 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2236 } 2237 } 2238 RTFREE(sro.ro_rt); 2239 } 2240 return (maxmtu); 2241 } 2242 #endif /* INET */ 2243 2244 #ifdef INET6 2245 u_long 2246 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2247 { 2248 struct route_in6 sro6; 2249 struct ifnet *ifp; 2250 u_long maxmtu = 0; 2251 2252 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2253 2254 bzero(&sro6, sizeof(sro6)); 2255 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2256 sro6.ro_dst.sin6_family = AF_INET6; 2257 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 2258 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 2259 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 2260 } 2261 if (sro6.ro_rt != NULL) { 2262 ifp = sro6.ro_rt->rt_ifp; 2263 if (sro6.ro_rt->rt_mtu == 0) 2264 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 2265 else 2266 maxmtu = min(sro6.ro_rt->rt_mtu, 2267 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 2268 2269 /* Report additional interface capabilities. */ 2270 if (cap != NULL) { 2271 if (ifp->if_capenable & IFCAP_TSO6 && 2272 ifp->if_hwassist & CSUM_TSO) { 2273 cap->ifcap |= CSUM_TSO; 2274 cap->tsomax = ifp->if_hw_tsomax; 2275 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2276 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2277 } 2278 } 2279 RTFREE(sro6.ro_rt); 2280 } 2281 2282 return (maxmtu); 2283 } 2284 #endif /* INET6 */ 2285 2286 #ifdef IPSEC 2287 /* compute ESP/AH header size for TCP, including outer IP header. */ 2288 size_t 2289 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2290 { 2291 struct inpcb *inp; 2292 struct mbuf *m; 2293 size_t hdrsiz; 2294 struct ip *ip; 2295 #ifdef INET6 2296 struct ip6_hdr *ip6; 2297 #endif 2298 struct tcphdr *th; 2299 2300 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2301 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2302 return (0); 2303 m = m_gethdr(M_NOWAIT, MT_DATA); 2304 if (!m) 2305 return (0); 2306 2307 #ifdef INET6 2308 if ((inp->inp_vflag & INP_IPV6) != 0) { 2309 ip6 = mtod(m, struct ip6_hdr *); 2310 th = (struct tcphdr *)(ip6 + 1); 2311 m->m_pkthdr.len = m->m_len = 2312 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2313 tcpip_fillheaders(inp, ip6, th); 2314 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2315 } else 2316 #endif /* INET6 */ 2317 { 2318 ip = mtod(m, struct ip *); 2319 th = (struct tcphdr *)(ip + 1); 2320 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2321 tcpip_fillheaders(inp, ip, th); 2322 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2323 } 2324 2325 m_free(m); 2326 return (hdrsiz); 2327 } 2328 #endif /* IPSEC */ 2329 2330 #ifdef TCP_SIGNATURE 2331 /* 2332 * Callback function invoked by m_apply() to digest TCP segment data 2333 * contained within an mbuf chain. 2334 */ 2335 static int 2336 tcp_signature_apply(void *fstate, void *data, u_int len) 2337 { 2338 2339 MD5Update(fstate, (u_char *)data, len); 2340 return (0); 2341 } 2342 2343 /* 2344 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2345 * search with the destination IP address, and a 'magic SPI' to be 2346 * determined by the application. This is hardcoded elsewhere to 1179 2347 */ 2348 struct secasvar * 2349 tcp_get_sav(struct mbuf *m, u_int direction) 2350 { 2351 union sockaddr_union dst; 2352 struct secasvar *sav; 2353 struct ip *ip; 2354 #ifdef INET6 2355 struct ip6_hdr *ip6; 2356 char ip6buf[INET6_ADDRSTRLEN]; 2357 #endif 2358 2359 /* Extract the destination from the IP header in the mbuf. */ 2360 bzero(&dst, sizeof(union sockaddr_union)); 2361 ip = mtod(m, struct ip *); 2362 #ifdef INET6 2363 ip6 = NULL; /* Make the compiler happy. */ 2364 #endif 2365 switch (ip->ip_v) { 2366 #ifdef INET 2367 case IPVERSION: 2368 dst.sa.sa_len = sizeof(struct sockaddr_in); 2369 dst.sa.sa_family = AF_INET; 2370 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2371 ip->ip_src : ip->ip_dst; 2372 break; 2373 #endif 2374 #ifdef INET6 2375 case (IPV6_VERSION >> 4): 2376 ip6 = mtod(m, struct ip6_hdr *); 2377 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2378 dst.sa.sa_family = AF_INET6; 2379 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2380 ip6->ip6_src : ip6->ip6_dst; 2381 break; 2382 #endif 2383 default: 2384 return (NULL); 2385 /* NOTREACHED */ 2386 break; 2387 } 2388 2389 /* Look up an SADB entry which matches the address of the peer. */ 2390 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2391 if (sav == NULL) { 2392 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2393 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2394 #ifdef INET6 2395 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2396 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2397 #endif 2398 "(unsupported)")); 2399 } 2400 2401 return (sav); 2402 } 2403 2404 /* 2405 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2406 * 2407 * Parameters: 2408 * m pointer to head of mbuf chain 2409 * len length of TCP segment data, excluding options 2410 * optlen length of TCP segment options 2411 * buf pointer to storage for computed MD5 digest 2412 * sav pointer to security assosiation 2413 * 2414 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2415 * When called from tcp_input(), we can be sure that th_sum has been 2416 * zeroed out and verified already. 2417 * 2418 * Releases reference to SADB key before return. 2419 * 2420 * Return 0 if successful, otherwise return -1. 2421 * 2422 */ 2423 int 2424 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2425 u_char *buf, struct secasvar *sav) 2426 { 2427 #ifdef INET 2428 struct ippseudo ippseudo; 2429 #endif 2430 MD5_CTX ctx; 2431 int doff; 2432 struct ip *ip; 2433 #ifdef INET 2434 struct ipovly *ipovly; 2435 #endif 2436 struct tcphdr *th; 2437 #ifdef INET6 2438 struct ip6_hdr *ip6; 2439 struct in6_addr in6; 2440 uint32_t plen; 2441 uint16_t nhdr; 2442 #endif 2443 u_short savecsum; 2444 2445 KASSERT(m != NULL, ("NULL mbuf chain")); 2446 KASSERT(buf != NULL, ("NULL signature pointer")); 2447 2448 /* Extract the destination from the IP header in the mbuf. */ 2449 ip = mtod(m, struct ip *); 2450 #ifdef INET6 2451 ip6 = NULL; /* Make the compiler happy. */ 2452 #endif 2453 2454 MD5Init(&ctx); 2455 /* 2456 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2457 * 2458 * XXX The ippseudo header MUST be digested in network byte order, 2459 * or else we'll fail the regression test. Assume all fields we've 2460 * been doing arithmetic on have been in host byte order. 2461 * XXX One cannot depend on ipovly->ih_len here. When called from 2462 * tcp_output(), the underlying ip_len member has not yet been set. 2463 */ 2464 switch (ip->ip_v) { 2465 #ifdef INET 2466 case IPVERSION: 2467 ipovly = (struct ipovly *)ip; 2468 ippseudo.ippseudo_src = ipovly->ih_src; 2469 ippseudo.ippseudo_dst = ipovly->ih_dst; 2470 ippseudo.ippseudo_pad = 0; 2471 ippseudo.ippseudo_p = IPPROTO_TCP; 2472 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2473 optlen); 2474 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2475 2476 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2477 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2478 break; 2479 #endif 2480 #ifdef INET6 2481 /* 2482 * RFC 2385, 2.0 Proposal 2483 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2484 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2485 * extended next header value (to form 32 bits), and 32-bit segment 2486 * length. 2487 * Note: Upper-Layer Packet Length comes before Next Header. 2488 */ 2489 case (IPV6_VERSION >> 4): 2490 in6 = ip6->ip6_src; 2491 in6_clearscope(&in6); 2492 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2493 in6 = ip6->ip6_dst; 2494 in6_clearscope(&in6); 2495 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2496 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2497 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2498 nhdr = 0; 2499 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2500 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2501 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2502 nhdr = IPPROTO_TCP; 2503 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2504 2505 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2506 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2507 break; 2508 #endif 2509 default: 2510 KEY_FREESAV(&sav); 2511 return (-1); 2512 /* NOTREACHED */ 2513 break; 2514 } 2515 2516 2517 /* 2518 * Step 2: Update MD5 hash with TCP header, excluding options. 2519 * The TCP checksum must be set to zero. 2520 */ 2521 savecsum = th->th_sum; 2522 th->th_sum = 0; 2523 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2524 th->th_sum = savecsum; 2525 2526 /* 2527 * Step 3: Update MD5 hash with TCP segment data. 2528 * Use m_apply() to avoid an early m_pullup(). 2529 */ 2530 if (len > 0) 2531 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2532 2533 /* 2534 * Step 4: Update MD5 hash with shared secret. 2535 */ 2536 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2537 MD5Final(buf, &ctx); 2538 2539 key_sa_recordxfer(sav, m); 2540 KEY_FREESAV(&sav); 2541 return (0); 2542 } 2543 2544 /* 2545 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2546 * 2547 * Return 0 if successful, otherwise return -1. 2548 */ 2549 int 2550 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2551 u_char *buf, u_int direction) 2552 { 2553 struct secasvar *sav; 2554 2555 if ((sav = tcp_get_sav(m, direction)) == NULL) 2556 return (-1); 2557 2558 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2559 } 2560 2561 /* 2562 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2563 * 2564 * Parameters: 2565 * m pointer to head of mbuf chain 2566 * len length of TCP segment data, excluding options 2567 * optlen length of TCP segment options 2568 * buf pointer to storage for computed MD5 digest 2569 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2570 * 2571 * Return 1 if successful, otherwise return 0. 2572 */ 2573 int 2574 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2575 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2576 { 2577 char tmpdigest[TCP_SIGLEN]; 2578 2579 if (tcp_sig_checksigs == 0) 2580 return (1); 2581 if ((tcpbflag & TF_SIGNATURE) == 0) { 2582 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2583 2584 /* 2585 * If this socket is not expecting signature but 2586 * the segment contains signature just fail. 2587 */ 2588 TCPSTAT_INC(tcps_sig_err_sigopt); 2589 TCPSTAT_INC(tcps_sig_rcvbadsig); 2590 return (0); 2591 } 2592 2593 /* Signature is not expected, and not present in segment. */ 2594 return (1); 2595 } 2596 2597 /* 2598 * If this socket is expecting signature but the segment does not 2599 * contain any just fail. 2600 */ 2601 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2602 TCPSTAT_INC(tcps_sig_err_nosigopt); 2603 TCPSTAT_INC(tcps_sig_rcvbadsig); 2604 return (0); 2605 } 2606 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2607 IPSEC_DIR_INBOUND) == -1) { 2608 TCPSTAT_INC(tcps_sig_err_buildsig); 2609 TCPSTAT_INC(tcps_sig_rcvbadsig); 2610 return (0); 2611 } 2612 2613 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2614 TCPSTAT_INC(tcps_sig_rcvbadsig); 2615 return (0); 2616 } 2617 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2618 return (1); 2619 } 2620 #endif /* TCP_SIGNATURE */ 2621 2622 static int 2623 sysctl_drop(SYSCTL_HANDLER_ARGS) 2624 { 2625 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2626 struct sockaddr_storage addrs[2]; 2627 struct inpcb *inp; 2628 struct tcpcb *tp; 2629 struct tcptw *tw; 2630 struct sockaddr_in *fin, *lin; 2631 #ifdef INET6 2632 struct sockaddr_in6 *fin6, *lin6; 2633 #endif 2634 int error; 2635 2636 inp = NULL; 2637 fin = lin = NULL; 2638 #ifdef INET6 2639 fin6 = lin6 = NULL; 2640 #endif 2641 error = 0; 2642 2643 if (req->oldptr != NULL || req->oldlen != 0) 2644 return (EINVAL); 2645 if (req->newptr == NULL) 2646 return (EPERM); 2647 if (req->newlen < sizeof(addrs)) 2648 return (ENOMEM); 2649 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2650 if (error) 2651 return (error); 2652 2653 switch (addrs[0].ss_family) { 2654 #ifdef INET6 2655 case AF_INET6: 2656 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2657 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2658 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2659 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2660 return (EINVAL); 2661 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2662 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2663 return (EINVAL); 2664 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2665 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2666 fin = (struct sockaddr_in *)&addrs[0]; 2667 lin = (struct sockaddr_in *)&addrs[1]; 2668 break; 2669 } 2670 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2671 if (error) 2672 return (error); 2673 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2674 if (error) 2675 return (error); 2676 break; 2677 #endif 2678 #ifdef INET 2679 case AF_INET: 2680 fin = (struct sockaddr_in *)&addrs[0]; 2681 lin = (struct sockaddr_in *)&addrs[1]; 2682 if (fin->sin_len != sizeof(struct sockaddr_in) || 2683 lin->sin_len != sizeof(struct sockaddr_in)) 2684 return (EINVAL); 2685 break; 2686 #endif 2687 default: 2688 return (EINVAL); 2689 } 2690 INP_INFO_RLOCK(&V_tcbinfo); 2691 switch (addrs[0].ss_family) { 2692 #ifdef INET6 2693 case AF_INET6: 2694 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2695 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2696 INPLOOKUP_WLOCKPCB, NULL); 2697 break; 2698 #endif 2699 #ifdef INET 2700 case AF_INET: 2701 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2702 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2703 break; 2704 #endif 2705 } 2706 if (inp != NULL) { 2707 if (inp->inp_flags & INP_TIMEWAIT) { 2708 /* 2709 * XXXRW: There currently exists a state where an 2710 * inpcb is present, but its timewait state has been 2711 * discarded. For now, don't allow dropping of this 2712 * type of inpcb. 2713 */ 2714 tw = intotw(inp); 2715 if (tw != NULL) 2716 tcp_twclose(tw, 0); 2717 else 2718 INP_WUNLOCK(inp); 2719 } else if (!(inp->inp_flags & INP_DROPPED) && 2720 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2721 tp = intotcpcb(inp); 2722 tp = tcp_drop(tp, ECONNABORTED); 2723 if (tp != NULL) 2724 INP_WUNLOCK(inp); 2725 } else 2726 INP_WUNLOCK(inp); 2727 } else 2728 error = ESRCH; 2729 INP_INFO_RUNLOCK(&V_tcbinfo); 2730 return (error); 2731 } 2732 2733 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2734 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2735 0, sysctl_drop, "", "Drop TCP connection"); 2736 2737 /* 2738 * Generate a standardized TCP log line for use throughout the 2739 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2740 * allow use in the interrupt context. 2741 * 2742 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2743 * NB: The function may return NULL if memory allocation failed. 2744 * 2745 * Due to header inclusion and ordering limitations the struct ip 2746 * and ip6_hdr pointers have to be passed as void pointers. 2747 */ 2748 char * 2749 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2750 const void *ip6hdr) 2751 { 2752 2753 /* Is logging enabled? */ 2754 if (tcp_log_in_vain == 0) 2755 return (NULL); 2756 2757 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2758 } 2759 2760 char * 2761 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2762 const void *ip6hdr) 2763 { 2764 2765 /* Is logging enabled? */ 2766 if (tcp_log_debug == 0) 2767 return (NULL); 2768 2769 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2770 } 2771 2772 static char * 2773 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2774 const void *ip6hdr) 2775 { 2776 char *s, *sp; 2777 size_t size; 2778 struct ip *ip; 2779 #ifdef INET6 2780 const struct ip6_hdr *ip6; 2781 2782 ip6 = (const struct ip6_hdr *)ip6hdr; 2783 #endif /* INET6 */ 2784 ip = (struct ip *)ip4hdr; 2785 2786 /* 2787 * The log line looks like this: 2788 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2789 */ 2790 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2791 sizeof(PRINT_TH_FLAGS) + 1 + 2792 #ifdef INET6 2793 2 * INET6_ADDRSTRLEN; 2794 #else 2795 2 * INET_ADDRSTRLEN; 2796 #endif /* INET6 */ 2797 2798 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2799 if (s == NULL) 2800 return (NULL); 2801 2802 strcat(s, "TCP: ["); 2803 sp = s + strlen(s); 2804 2805 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2806 inet_ntoa_r(inc->inc_faddr, sp); 2807 sp = s + strlen(s); 2808 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2809 sp = s + strlen(s); 2810 inet_ntoa_r(inc->inc_laddr, sp); 2811 sp = s + strlen(s); 2812 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2813 #ifdef INET6 2814 } else if (inc) { 2815 ip6_sprintf(sp, &inc->inc6_faddr); 2816 sp = s + strlen(s); 2817 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2818 sp = s + strlen(s); 2819 ip6_sprintf(sp, &inc->inc6_laddr); 2820 sp = s + strlen(s); 2821 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2822 } else if (ip6 && th) { 2823 ip6_sprintf(sp, &ip6->ip6_src); 2824 sp = s + strlen(s); 2825 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2826 sp = s + strlen(s); 2827 ip6_sprintf(sp, &ip6->ip6_dst); 2828 sp = s + strlen(s); 2829 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2830 #endif /* INET6 */ 2831 #ifdef INET 2832 } else if (ip && th) { 2833 inet_ntoa_r(ip->ip_src, sp); 2834 sp = s + strlen(s); 2835 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2836 sp = s + strlen(s); 2837 inet_ntoa_r(ip->ip_dst, sp); 2838 sp = s + strlen(s); 2839 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2840 #endif /* INET */ 2841 } else { 2842 free(s, M_TCPLOG); 2843 return (NULL); 2844 } 2845 sp = s + strlen(s); 2846 if (th) 2847 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2848 if (*(s + size - 1) != '\0') 2849 panic("%s: string too long", __func__); 2850 return (s); 2851 } 2852 2853 /* 2854 * A subroutine which makes it easy to track TCP state changes with DTrace. 2855 * This function shouldn't be called for t_state initializations that don't 2856 * correspond to actual TCP state transitions. 2857 */ 2858 void 2859 tcp_state_change(struct tcpcb *tp, int newstate) 2860 { 2861 #if defined(KDTRACE_HOOKS) 2862 int pstate = tp->t_state; 2863 #endif 2864 2865 tp->t_state = newstate; 2866 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2867 } 2868