1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_compat.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 #include "opt_ipsec.h" 39 #include "opt_tcpdebug.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/callout.h> 44 #include <sys/eventhandler.h> 45 #include <sys/hhook.h> 46 #include <sys/kernel.h> 47 #include <sys/khelp.h> 48 #include <sys/sysctl.h> 49 #include <sys/jail.h> 50 #include <sys/malloc.h> 51 #include <sys/refcount.h> 52 #include <sys/mbuf.h> 53 #ifdef INET6 54 #include <sys/domain.h> 55 #endif 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/sdt.h> 59 #include <sys/socket.h> 60 #include <sys/socketvar.h> 61 #include <sys/protosw.h> 62 #include <sys/random.h> 63 64 #include <vm/uma.h> 65 66 #include <net/route.h> 67 #include <net/if.h> 68 #include <net/if_var.h> 69 #include <net/vnet.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_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.h> 91 #include <netinet/tcp_fsm.h> 92 #include <netinet/tcp_seq.h> 93 #include <netinet/tcp_timer.h> 94 #include <netinet/tcp_var.h> 95 #include <netinet/tcp_syncache.h> 96 #include <netinet/tcp_cc.h> 97 #ifdef INET6 98 #include <netinet6/tcp6_var.h> 99 #endif 100 #include <netinet/tcpip.h> 101 #ifdef TCPPCAP 102 #include <netinet/tcp_pcap.h> 103 #endif 104 #ifdef TCPDEBUG 105 #include <netinet/tcp_debug.h> 106 #endif 107 #ifdef INET6 108 #include <netinet6/ip6protosw.h> 109 #endif 110 #ifdef TCP_OFFLOAD 111 #include <netinet/tcp_offload.h> 112 #endif 113 114 #ifdef IPSEC 115 #include <netipsec/ipsec.h> 116 #include <netipsec/xform.h> 117 #ifdef INET6 118 #include <netipsec/ipsec6.h> 119 #endif 120 #include <netipsec/key.h> 121 #include <sys/syslog.h> 122 #endif /*IPSEC*/ 123 124 #include <machine/in_cksum.h> 125 #include <sys/md5.h> 126 127 #include <security/mac/mac_framework.h> 128 129 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 130 #ifdef INET6 131 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 132 #endif 133 134 struct rwlock tcp_function_lock; 135 136 static int 137 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 138 { 139 int error, new; 140 141 new = V_tcp_mssdflt; 142 error = sysctl_handle_int(oidp, &new, 0, req); 143 if (error == 0 && req->newptr) { 144 if (new < TCP_MINMSS) 145 error = EINVAL; 146 else 147 V_tcp_mssdflt = new; 148 } 149 return (error); 150 } 151 152 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 153 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 154 &sysctl_net_inet_tcp_mss_check, "I", 155 "Default TCP Maximum Segment Size"); 156 157 #ifdef INET6 158 static int 159 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 160 { 161 int error, new; 162 163 new = V_tcp_v6mssdflt; 164 error = sysctl_handle_int(oidp, &new, 0, req); 165 if (error == 0 && req->newptr) { 166 if (new < TCP_MINMSS) 167 error = EINVAL; 168 else 169 V_tcp_v6mssdflt = new; 170 } 171 return (error); 172 } 173 174 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 175 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 176 &sysctl_net_inet_tcp_mss_v6_check, "I", 177 "Default TCP Maximum Segment Size for IPv6"); 178 #endif /* INET6 */ 179 180 /* 181 * Minimum MSS we accept and use. This prevents DoS attacks where 182 * we are forced to a ridiculous low MSS like 20 and send hundreds 183 * of packets instead of one. The effect scales with the available 184 * bandwidth and quickly saturates the CPU and network interface 185 * with packet generation and sending. Set to zero to disable MINMSS 186 * checking. This setting prevents us from sending too small packets. 187 */ 188 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 190 &VNET_NAME(tcp_minmss), 0, 191 "Minimum TCP Maximum Segment Size"); 192 193 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 194 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 195 &VNET_NAME(tcp_do_rfc1323), 0, 196 "Enable rfc1323 (high performance TCP) extensions"); 197 198 static int tcp_log_debug = 0; 199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 200 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 201 202 static int tcp_tcbhashsize; 203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 204 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 205 206 static int do_tcpdrain = 1; 207 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 208 "Enable tcp_drain routine for extra help when low on mbufs"); 209 210 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 211 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 212 213 static VNET_DEFINE(int, icmp_may_rst) = 1; 214 #define V_icmp_may_rst VNET(icmp_may_rst) 215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 216 &VNET_NAME(icmp_may_rst), 0, 217 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 218 219 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 220 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 221 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 222 &VNET_NAME(tcp_isn_reseed_interval), 0, 223 "Seconds between reseeding of ISN secret"); 224 225 static int tcp_soreceive_stream; 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 227 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 228 229 #ifdef TCP_SIGNATURE 230 static int tcp_sig_checksigs = 1; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 232 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 233 #endif 234 235 VNET_DEFINE(uma_zone_t, sack_hole_zone); 236 #define V_sack_hole_zone VNET(sack_hole_zone) 237 238 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 239 240 static struct inpcb *tcp_notify(struct inpcb *, int); 241 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 242 static void tcp_mtudisc(struct inpcb *, int); 243 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 244 void *ip4hdr, const void *ip6hdr); 245 static void tcp_timer_discard(struct tcpcb *, uint32_t); 246 247 248 static struct tcp_function_block tcp_def_funcblk = { 249 "default", 250 tcp_output, 251 tcp_do_segment, 252 tcp_default_ctloutput, 253 NULL, 254 NULL, 255 NULL, 256 NULL, 257 NULL, 258 NULL, 259 NULL, 260 0, 261 0 262 }; 263 264 struct tcp_funchead t_functions; 265 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 266 267 static struct tcp_function_block * 268 find_tcp_functions_locked(struct tcp_function_set *fs) 269 { 270 struct tcp_function *f; 271 struct tcp_function_block *blk=NULL; 272 273 TAILQ_FOREACH(f, &t_functions, tf_next) { 274 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 275 blk = f->tf_fb; 276 break; 277 } 278 } 279 return(blk); 280 } 281 282 static struct tcp_function_block * 283 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 284 { 285 struct tcp_function_block *rblk=NULL; 286 struct tcp_function *f; 287 288 TAILQ_FOREACH(f, &t_functions, tf_next) { 289 if (f->tf_fb == blk) { 290 rblk = blk; 291 if (s) { 292 *s = f; 293 } 294 break; 295 } 296 } 297 return (rblk); 298 } 299 300 struct tcp_function_block * 301 find_and_ref_tcp_functions(struct tcp_function_set *fs) 302 { 303 struct tcp_function_block *blk; 304 305 rw_rlock(&tcp_function_lock); 306 blk = find_tcp_functions_locked(fs); 307 if (blk) 308 refcount_acquire(&blk->tfb_refcnt); 309 rw_runlock(&tcp_function_lock); 310 return(blk); 311 } 312 313 struct tcp_function_block * 314 find_and_ref_tcp_fb(struct tcp_function_block *blk) 315 { 316 struct tcp_function_block *rblk; 317 318 rw_rlock(&tcp_function_lock); 319 rblk = find_tcp_fb_locked(blk, NULL); 320 if (rblk) 321 refcount_acquire(&rblk->tfb_refcnt); 322 rw_runlock(&tcp_function_lock); 323 return(rblk); 324 } 325 326 327 static int 328 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 329 { 330 int error=ENOENT; 331 struct tcp_function_set fs; 332 struct tcp_function_block *blk; 333 334 memset(&fs, 0, sizeof(fs)); 335 rw_rlock(&tcp_function_lock); 336 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 337 if (blk) { 338 /* Found him */ 339 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 340 fs.pcbcnt = blk->tfb_refcnt; 341 } 342 rw_runlock(&tcp_function_lock); 343 error = sysctl_handle_string(oidp, fs.function_set_name, 344 sizeof(fs.function_set_name), req); 345 346 /* Check for error or no change */ 347 if (error != 0 || req->newptr == NULL) 348 return(error); 349 350 rw_wlock(&tcp_function_lock); 351 blk = find_tcp_functions_locked(&fs); 352 if ((blk == NULL) || 353 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 354 error = ENOENT; 355 goto done; 356 } 357 tcp_func_set_ptr = blk; 358 done: 359 rw_wunlock(&tcp_function_lock); 360 return (error); 361 } 362 363 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 364 CTLTYPE_STRING | CTLFLAG_RW, 365 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 366 "Set/get the default TCP functions"); 367 368 static int 369 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 370 { 371 int error, cnt, linesz; 372 struct tcp_function *f; 373 char *buffer, *cp; 374 size_t bufsz, outsz; 375 376 cnt = 0; 377 rw_rlock(&tcp_function_lock); 378 TAILQ_FOREACH(f, &t_functions, tf_next) { 379 cnt++; 380 } 381 rw_runlock(&tcp_function_lock); 382 383 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 384 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 385 386 error = 0; 387 cp = buffer; 388 389 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 390 cp += linesz; 391 bufsz -= linesz; 392 outsz = linesz; 393 394 rw_rlock(&tcp_function_lock); 395 TAILQ_FOREACH(f, &t_functions, tf_next) { 396 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 397 f->tf_fb->tfb_tcp_block_name, 398 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 399 f->tf_fb->tfb_refcnt); 400 if (linesz >= bufsz) { 401 error = EOVERFLOW; 402 break; 403 } 404 cp += linesz; 405 bufsz -= linesz; 406 outsz += linesz; 407 } 408 rw_runlock(&tcp_function_lock); 409 if (error == 0) 410 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 411 free(buffer, M_TEMP); 412 return (error); 413 } 414 415 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 416 CTLTYPE_STRING|CTLFLAG_RD, 417 NULL, 0, sysctl_net_inet_list_available, "A", 418 "list available TCP Function sets"); 419 420 /* 421 * Target size of TCP PCB hash tables. Must be a power of two. 422 * 423 * Note that this can be overridden by the kernel environment 424 * variable net.inet.tcp.tcbhashsize 425 */ 426 #ifndef TCBHASHSIZE 427 #define TCBHASHSIZE 0 428 #endif 429 430 /* 431 * XXX 432 * Callouts should be moved into struct tcp directly. They are currently 433 * separate because the tcpcb structure is exported to userland for sysctl 434 * parsing purposes, which do not know about callouts. 435 */ 436 struct tcpcb_mem { 437 struct tcpcb tcb; 438 struct tcp_timer tt; 439 struct cc_var ccv; 440 struct osd osd; 441 }; 442 443 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 444 #define V_tcpcb_zone VNET(tcpcb_zone) 445 446 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 447 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 448 449 static struct mtx isn_mtx; 450 451 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 452 #define ISN_LOCK() mtx_lock(&isn_mtx) 453 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 454 455 /* 456 * TCP initialization. 457 */ 458 static void 459 tcp_zone_change(void *tag) 460 { 461 462 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 463 uma_zone_set_max(V_tcpcb_zone, maxsockets); 464 tcp_tw_zone_change(); 465 } 466 467 static int 468 tcp_inpcb_init(void *mem, int size, int flags) 469 { 470 struct inpcb *inp = mem; 471 472 INP_LOCK_INIT(inp, "inp", "tcpinp"); 473 return (0); 474 } 475 476 /* 477 * Take a value and get the next power of 2 that doesn't overflow. 478 * Used to size the tcp_inpcb hash buckets. 479 */ 480 static int 481 maketcp_hashsize(int size) 482 { 483 int hashsize; 484 485 /* 486 * auto tune. 487 * get the next power of 2 higher than maxsockets. 488 */ 489 hashsize = 1 << fls(size); 490 /* catch overflow, and just go one power of 2 smaller */ 491 if (hashsize < size) { 492 hashsize = 1 << (fls(size) - 1); 493 } 494 return (hashsize); 495 } 496 497 int 498 register_tcp_functions(struct tcp_function_block *blk, int wait) 499 { 500 struct tcp_function_block *lblk; 501 struct tcp_function *n; 502 struct tcp_function_set fs; 503 504 if ((blk->tfb_tcp_output == NULL) || 505 (blk->tfb_tcp_do_segment == NULL) || 506 (blk->tfb_tcp_ctloutput == NULL) || 507 (strlen(blk->tfb_tcp_block_name) == 0)) { 508 /* 509 * These functions are required and you 510 * need a name. 511 */ 512 return (EINVAL); 513 } 514 if (blk->tfb_tcp_timer_stop_all || 515 blk->tfb_tcp_timers_left || 516 blk->tfb_tcp_timer_activate || 517 blk->tfb_tcp_timer_active || 518 blk->tfb_tcp_timer_stop) { 519 /* 520 * If you define one timer function you 521 * must have them all. 522 */ 523 if ((blk->tfb_tcp_timer_stop_all == NULL) || 524 (blk->tfb_tcp_timers_left == NULL) || 525 (blk->tfb_tcp_timer_activate == NULL) || 526 (blk->tfb_tcp_timer_active == NULL) || 527 (blk->tfb_tcp_timer_stop == NULL)) { 528 return (EINVAL); 529 } 530 } 531 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 532 if (n == NULL) { 533 return (ENOMEM); 534 } 535 n->tf_fb = blk; 536 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 537 rw_wlock(&tcp_function_lock); 538 lblk = find_tcp_functions_locked(&fs); 539 if (lblk) { 540 /* Duplicate name space not allowed */ 541 rw_wunlock(&tcp_function_lock); 542 free(n, M_TCPFUNCTIONS); 543 return (EALREADY); 544 } 545 refcount_init(&blk->tfb_refcnt, 0); 546 blk->tfb_flags = 0; 547 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 548 rw_wunlock(&tcp_function_lock); 549 return(0); 550 } 551 552 int 553 deregister_tcp_functions(struct tcp_function_block *blk) 554 { 555 struct tcp_function_block *lblk; 556 struct tcp_function *f; 557 int error=ENOENT; 558 559 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 560 /* You can't un-register the default */ 561 return (EPERM); 562 } 563 rw_wlock(&tcp_function_lock); 564 if (blk == tcp_func_set_ptr) { 565 /* You can't free the current default */ 566 rw_wunlock(&tcp_function_lock); 567 return (EBUSY); 568 } 569 if (blk->tfb_refcnt) { 570 /* Still tcb attached, mark it. */ 571 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 572 rw_wunlock(&tcp_function_lock); 573 return (EBUSY); 574 } 575 lblk = find_tcp_fb_locked(blk, &f); 576 if (lblk) { 577 /* Found */ 578 TAILQ_REMOVE(&t_functions, f, tf_next); 579 f->tf_fb = NULL; 580 free(f, M_TCPFUNCTIONS); 581 error = 0; 582 } 583 rw_wunlock(&tcp_function_lock); 584 return (error); 585 } 586 587 void 588 tcp_init(void) 589 { 590 const char *tcbhash_tuneable; 591 int hashsize; 592 593 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 594 595 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 596 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 597 printf("%s: WARNING: unable to register helper hook\n", __func__); 598 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 599 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 600 printf("%s: WARNING: unable to register helper hook\n", __func__); 601 hashsize = TCBHASHSIZE; 602 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 603 if (hashsize == 0) { 604 /* 605 * Auto tune the hash size based on maxsockets. 606 * A perfect hash would have a 1:1 mapping 607 * (hashsize = maxsockets) however it's been 608 * suggested that O(2) average is better. 609 */ 610 hashsize = maketcp_hashsize(maxsockets / 4); 611 /* 612 * Our historical default is 512, 613 * do not autotune lower than this. 614 */ 615 if (hashsize < 512) 616 hashsize = 512; 617 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 618 printf("%s: %s auto tuned to %d\n", __func__, 619 tcbhash_tuneable, hashsize); 620 } 621 /* 622 * We require a hashsize to be a power of two. 623 * Previously if it was not a power of two we would just reset it 624 * back to 512, which could be a nasty surprise if you did not notice 625 * the error message. 626 * Instead what we do is clip it to the closest power of two lower 627 * than the specified hash value. 628 */ 629 if (!powerof2(hashsize)) { 630 int oldhashsize = hashsize; 631 632 hashsize = maketcp_hashsize(hashsize); 633 /* prevent absurdly low value */ 634 if (hashsize < 16) 635 hashsize = 16; 636 printf("%s: WARNING: TCB hash size not a power of 2, " 637 "clipped from %d to %d.\n", __func__, oldhashsize, 638 hashsize); 639 } 640 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 641 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 642 IPI_HASHFIELDS_4TUPLE); 643 644 /* 645 * These have to be type stable for the benefit of the timers. 646 */ 647 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 648 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 649 uma_zone_set_max(V_tcpcb_zone, maxsockets); 650 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 651 652 tcp_tw_init(); 653 syncache_init(); 654 tcp_hc_init(); 655 656 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 657 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 658 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 659 660 /* Skip initialization of globals for non-default instances. */ 661 if (!IS_DEFAULT_VNET(curvnet)) 662 return; 663 664 tcp_reass_global_init(); 665 666 /* XXX virtualize those bellow? */ 667 tcp_delacktime = TCPTV_DELACK; 668 tcp_keepinit = TCPTV_KEEP_INIT; 669 tcp_keepidle = TCPTV_KEEP_IDLE; 670 tcp_keepintvl = TCPTV_KEEPINTVL; 671 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 672 tcp_msl = TCPTV_MSL; 673 tcp_rexmit_min = TCPTV_MIN; 674 if (tcp_rexmit_min < 1) 675 tcp_rexmit_min = 1; 676 tcp_rexmit_slop = TCPTV_CPU_VAR; 677 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 678 tcp_tcbhashsize = hashsize; 679 /* Setup the tcp function block list */ 680 TAILQ_INIT(&t_functions); 681 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 682 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 683 684 if (tcp_soreceive_stream) { 685 #ifdef INET 686 tcp_usrreqs.pru_soreceive = soreceive_stream; 687 #endif 688 #ifdef INET6 689 tcp6_usrreqs.pru_soreceive = soreceive_stream; 690 #endif /* INET6 */ 691 } 692 693 #ifdef INET6 694 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 695 #else /* INET6 */ 696 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 697 #endif /* INET6 */ 698 if (max_protohdr < TCP_MINPROTOHDR) 699 max_protohdr = TCP_MINPROTOHDR; 700 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 701 panic("tcp_init"); 702 #undef TCP_MINPROTOHDR 703 704 ISN_LOCK_INIT(); 705 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 706 SHUTDOWN_PRI_DEFAULT); 707 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 708 EVENTHANDLER_PRI_ANY); 709 #ifdef TCPPCAP 710 tcp_pcap_init(); 711 #endif 712 713 #ifdef TCP_RFC7413 714 tcp_fastopen_init(); 715 #endif 716 } 717 718 #ifdef VIMAGE 719 void 720 tcp_destroy(void) 721 { 722 int error; 723 724 #ifdef TCP_RFC7413 725 tcp_fastopen_destroy(); 726 #endif 727 tcp_hc_destroy(); 728 syncache_destroy(); 729 tcp_tw_destroy(); 730 in_pcbinfo_destroy(&V_tcbinfo); 731 uma_zdestroy(V_sack_hole_zone); 732 uma_zdestroy(V_tcpcb_zone); 733 734 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 735 if (error != 0) { 736 printf("%s: WARNING: unable to deregister helper hook " 737 "type=%d, id=%d: error %d returned\n", __func__, 738 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 739 } 740 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 741 if (error != 0) { 742 printf("%s: WARNING: unable to deregister helper hook " 743 "type=%d, id=%d: error %d returned\n", __func__, 744 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 745 } 746 } 747 #endif 748 749 void 750 tcp_fini(void *xtp) 751 { 752 753 } 754 755 /* 756 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 757 * tcp_template used to store this data in mbufs, but we now recopy it out 758 * of the tcpcb each time to conserve mbufs. 759 */ 760 void 761 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 762 { 763 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 764 765 INP_WLOCK_ASSERT(inp); 766 767 #ifdef INET6 768 if ((inp->inp_vflag & INP_IPV6) != 0) { 769 struct ip6_hdr *ip6; 770 771 ip6 = (struct ip6_hdr *)ip_ptr; 772 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 773 (inp->inp_flow & IPV6_FLOWINFO_MASK); 774 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 775 (IPV6_VERSION & IPV6_VERSION_MASK); 776 ip6->ip6_nxt = IPPROTO_TCP; 777 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 778 ip6->ip6_src = inp->in6p_laddr; 779 ip6->ip6_dst = inp->in6p_faddr; 780 } 781 #endif /* INET6 */ 782 #if defined(INET6) && defined(INET) 783 else 784 #endif 785 #ifdef INET 786 { 787 struct ip *ip; 788 789 ip = (struct ip *)ip_ptr; 790 ip->ip_v = IPVERSION; 791 ip->ip_hl = 5; 792 ip->ip_tos = inp->inp_ip_tos; 793 ip->ip_len = 0; 794 ip->ip_id = 0; 795 ip->ip_off = 0; 796 ip->ip_ttl = inp->inp_ip_ttl; 797 ip->ip_sum = 0; 798 ip->ip_p = IPPROTO_TCP; 799 ip->ip_src = inp->inp_laddr; 800 ip->ip_dst = inp->inp_faddr; 801 } 802 #endif /* INET */ 803 th->th_sport = inp->inp_lport; 804 th->th_dport = inp->inp_fport; 805 th->th_seq = 0; 806 th->th_ack = 0; 807 th->th_x2 = 0; 808 th->th_off = 5; 809 th->th_flags = 0; 810 th->th_win = 0; 811 th->th_urp = 0; 812 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 813 } 814 815 /* 816 * Create template to be used to send tcp packets on a connection. 817 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 818 * use for this function is in keepalives, which use tcp_respond. 819 */ 820 struct tcptemp * 821 tcpip_maketemplate(struct inpcb *inp) 822 { 823 struct tcptemp *t; 824 825 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 826 if (t == NULL) 827 return (NULL); 828 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 829 return (t); 830 } 831 832 /* 833 * Send a single message to the TCP at address specified by 834 * the given TCP/IP header. If m == NULL, then we make a copy 835 * of the tcpiphdr at th and send directly to the addressed host. 836 * This is used to force keep alive messages out using the TCP 837 * template for a connection. If flags are given then we send 838 * a message back to the TCP which originated the segment th, 839 * and discard the mbuf containing it and any other attached mbufs. 840 * 841 * In any case the ack and sequence number of the transmitted 842 * segment are as specified by the parameters. 843 * 844 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 845 */ 846 void 847 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 848 tcp_seq ack, tcp_seq seq, int flags) 849 { 850 int tlen; 851 int win = 0; 852 struct ip *ip; 853 struct tcphdr *nth; 854 #ifdef INET6 855 struct ip6_hdr *ip6; 856 int isipv6; 857 #endif /* INET6 */ 858 int ipflags = 0; 859 struct inpcb *inp; 860 861 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 862 863 #ifdef INET6 864 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 865 ip6 = ipgen; 866 #endif /* INET6 */ 867 ip = ipgen; 868 869 if (tp != NULL) { 870 inp = tp->t_inpcb; 871 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 872 INP_WLOCK_ASSERT(inp); 873 } else 874 inp = NULL; 875 876 if (tp != NULL) { 877 if (!(flags & TH_RST)) { 878 win = sbspace(&inp->inp_socket->so_rcv); 879 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 880 win = (long)TCP_MAXWIN << tp->rcv_scale; 881 } 882 } 883 if (m == NULL) { 884 m = m_gethdr(M_NOWAIT, MT_DATA); 885 if (m == NULL) 886 return; 887 tlen = 0; 888 m->m_data += max_linkhdr; 889 #ifdef INET6 890 if (isipv6) { 891 bcopy((caddr_t)ip6, mtod(m, caddr_t), 892 sizeof(struct ip6_hdr)); 893 ip6 = mtod(m, struct ip6_hdr *); 894 nth = (struct tcphdr *)(ip6 + 1); 895 } else 896 #endif /* INET6 */ 897 { 898 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 899 ip = mtod(m, struct ip *); 900 nth = (struct tcphdr *)(ip + 1); 901 } 902 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 903 flags = TH_ACK; 904 } else { 905 /* 906 * reuse the mbuf. 907 * XXX MRT We inherrit the FIB, which is lucky. 908 */ 909 m_freem(m->m_next); 910 m->m_next = NULL; 911 m->m_data = (caddr_t)ipgen; 912 /* m_len is set later */ 913 tlen = 0; 914 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 915 #ifdef INET6 916 if (isipv6) { 917 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 918 nth = (struct tcphdr *)(ip6 + 1); 919 } else 920 #endif /* INET6 */ 921 { 922 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 923 nth = (struct tcphdr *)(ip + 1); 924 } 925 if (th != nth) { 926 /* 927 * this is usually a case when an extension header 928 * exists between the IPv6 header and the 929 * TCP header. 930 */ 931 nth->th_sport = th->th_sport; 932 nth->th_dport = th->th_dport; 933 } 934 xchg(nth->th_dport, nth->th_sport, uint16_t); 935 #undef xchg 936 } 937 #ifdef INET6 938 if (isipv6) { 939 ip6->ip6_flow = 0; 940 ip6->ip6_vfc = IPV6_VERSION; 941 ip6->ip6_nxt = IPPROTO_TCP; 942 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 943 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 944 } 945 #endif 946 #if defined(INET) && defined(INET6) 947 else 948 #endif 949 #ifdef INET 950 { 951 tlen += sizeof (struct tcpiphdr); 952 ip->ip_len = htons(tlen); 953 ip->ip_ttl = V_ip_defttl; 954 if (V_path_mtu_discovery) 955 ip->ip_off |= htons(IP_DF); 956 } 957 #endif 958 m->m_len = tlen; 959 m->m_pkthdr.len = tlen; 960 m->m_pkthdr.rcvif = NULL; 961 #ifdef MAC 962 if (inp != NULL) { 963 /* 964 * Packet is associated with a socket, so allow the 965 * label of the response to reflect the socket label. 966 */ 967 INP_WLOCK_ASSERT(inp); 968 mac_inpcb_create_mbuf(inp, m); 969 } else { 970 /* 971 * Packet is not associated with a socket, so possibly 972 * update the label in place. 973 */ 974 mac_netinet_tcp_reply(m); 975 } 976 #endif 977 nth->th_seq = htonl(seq); 978 nth->th_ack = htonl(ack); 979 nth->th_x2 = 0; 980 nth->th_off = sizeof (struct tcphdr) >> 2; 981 nth->th_flags = flags; 982 if (tp != NULL) 983 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 984 else 985 nth->th_win = htons((u_short)win); 986 nth->th_urp = 0; 987 988 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 989 #ifdef INET6 990 if (isipv6) { 991 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 992 nth->th_sum = in6_cksum_pseudo(ip6, 993 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 994 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 995 NULL, NULL); 996 } 997 #endif /* INET6 */ 998 #if defined(INET6) && defined(INET) 999 else 1000 #endif 1001 #ifdef INET 1002 { 1003 m->m_pkthdr.csum_flags = CSUM_TCP; 1004 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1005 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1006 } 1007 #endif /* INET */ 1008 #ifdef TCPDEBUG 1009 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1010 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1011 #endif 1012 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *)); 1013 if (flags & TH_RST) 1014 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1015 tp, nth); 1016 1017 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1018 #ifdef INET6 1019 if (isipv6) 1020 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 1021 #endif /* INET6 */ 1022 #if defined(INET) && defined(INET6) 1023 else 1024 #endif 1025 #ifdef INET 1026 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 1027 #endif 1028 } 1029 1030 /* 1031 * Create a new TCP control block, making an 1032 * empty reassembly queue and hooking it to the argument 1033 * protocol control block. The `inp' parameter must have 1034 * come from the zone allocator set up in tcp_init(). 1035 */ 1036 struct tcpcb * 1037 tcp_newtcpcb(struct inpcb *inp) 1038 { 1039 struct tcpcb_mem *tm; 1040 struct tcpcb *tp; 1041 #ifdef INET6 1042 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1043 #endif /* INET6 */ 1044 1045 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1046 if (tm == NULL) 1047 return (NULL); 1048 tp = &tm->tcb; 1049 1050 /* Initialise cc_var struct for this tcpcb. */ 1051 tp->ccv = &tm->ccv; 1052 tp->ccv->type = IPPROTO_TCP; 1053 tp->ccv->ccvc.tcp = tp; 1054 rw_rlock(&tcp_function_lock); 1055 tp->t_fb = tcp_func_set_ptr; 1056 refcount_acquire(&tp->t_fb->tfb_refcnt); 1057 rw_runlock(&tcp_function_lock); 1058 if (tp->t_fb->tfb_tcp_fb_init) { 1059 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1060 } 1061 /* 1062 * Use the current system default CC algorithm. 1063 */ 1064 CC_LIST_RLOCK(); 1065 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1066 CC_ALGO(tp) = CC_DEFAULT(); 1067 CC_LIST_RUNLOCK(); 1068 1069 if (CC_ALGO(tp)->cb_init != NULL) 1070 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1071 if (tp->t_fb->tfb_tcp_fb_fini) 1072 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1073 refcount_release(&tp->t_fb->tfb_refcnt); 1074 uma_zfree(V_tcpcb_zone, tm); 1075 return (NULL); 1076 } 1077 1078 tp->osd = &tm->osd; 1079 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1080 if (tp->t_fb->tfb_tcp_fb_fini) 1081 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1082 refcount_release(&tp->t_fb->tfb_refcnt); 1083 uma_zfree(V_tcpcb_zone, tm); 1084 return (NULL); 1085 } 1086 1087 #ifdef VIMAGE 1088 tp->t_vnet = inp->inp_vnet; 1089 #endif 1090 tp->t_timers = &tm->tt; 1091 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1092 tp->t_maxseg = 1093 #ifdef INET6 1094 isipv6 ? V_tcp_v6mssdflt : 1095 #endif /* INET6 */ 1096 V_tcp_mssdflt; 1097 1098 /* Set up our timeouts. */ 1099 callout_init(&tp->t_timers->tt_rexmt, 1); 1100 callout_init(&tp->t_timers->tt_persist, 1); 1101 callout_init(&tp->t_timers->tt_keep, 1); 1102 callout_init(&tp->t_timers->tt_2msl, 1); 1103 callout_init(&tp->t_timers->tt_delack, 1); 1104 1105 if (V_tcp_do_rfc1323) 1106 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1107 if (V_tcp_do_sack) 1108 tp->t_flags |= TF_SACK_PERMIT; 1109 TAILQ_INIT(&tp->snd_holes); 1110 /* 1111 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1112 * is called. 1113 */ 1114 in_pcbref(inp); /* Reference for tcpcb */ 1115 tp->t_inpcb = inp; 1116 1117 /* 1118 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1119 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1120 * reasonable initial retransmit time. 1121 */ 1122 tp->t_srtt = TCPTV_SRTTBASE; 1123 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1124 tp->t_rttmin = tcp_rexmit_min; 1125 tp->t_rxtcur = TCPTV_RTOBASE; 1126 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1127 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1128 tp->t_rcvtime = ticks; 1129 /* 1130 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1131 * because the socket may be bound to an IPv6 wildcard address, 1132 * which may match an IPv4-mapped IPv6 address. 1133 */ 1134 inp->inp_ip_ttl = V_ip_defttl; 1135 inp->inp_ppcb = tp; 1136 #ifdef TCPPCAP 1137 /* 1138 * Init the TCP PCAP queues. 1139 */ 1140 tcp_pcap_tcpcb_init(tp); 1141 #endif 1142 return (tp); /* XXX */ 1143 } 1144 1145 /* 1146 * Switch the congestion control algorithm back to NewReno for any active 1147 * control blocks using an algorithm which is about to go away. 1148 * This ensures the CC framework can allow the unload to proceed without leaving 1149 * any dangling pointers which would trigger a panic. 1150 * Returning non-zero would inform the CC framework that something went wrong 1151 * and it would be unsafe to allow the unload to proceed. However, there is no 1152 * way for this to occur with this implementation so we always return zero. 1153 */ 1154 int 1155 tcp_ccalgounload(struct cc_algo *unload_algo) 1156 { 1157 struct cc_algo *tmpalgo; 1158 struct inpcb *inp; 1159 struct tcpcb *tp; 1160 VNET_ITERATOR_DECL(vnet_iter); 1161 1162 /* 1163 * Check all active control blocks across all network stacks and change 1164 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1165 * requires cleanup code to be run, call it. 1166 */ 1167 VNET_LIST_RLOCK(); 1168 VNET_FOREACH(vnet_iter) { 1169 CURVNET_SET(vnet_iter); 1170 INP_INFO_WLOCK(&V_tcbinfo); 1171 /* 1172 * New connections already part way through being initialised 1173 * with the CC algo we're removing will not race with this code 1174 * because the INP_INFO_WLOCK is held during initialisation. We 1175 * therefore don't enter the loop below until the connection 1176 * list has stabilised. 1177 */ 1178 LIST_FOREACH(inp, &V_tcb, inp_list) { 1179 INP_WLOCK(inp); 1180 /* Important to skip tcptw structs. */ 1181 if (!(inp->inp_flags & INP_TIMEWAIT) && 1182 (tp = intotcpcb(inp)) != NULL) { 1183 /* 1184 * By holding INP_WLOCK here, we are assured 1185 * that the connection is not currently 1186 * executing inside the CC module's functions 1187 * i.e. it is safe to make the switch back to 1188 * NewReno. 1189 */ 1190 if (CC_ALGO(tp) == unload_algo) { 1191 tmpalgo = CC_ALGO(tp); 1192 /* NewReno does not require any init. */ 1193 CC_ALGO(tp) = &newreno_cc_algo; 1194 if (tmpalgo->cb_destroy != NULL) 1195 tmpalgo->cb_destroy(tp->ccv); 1196 } 1197 } 1198 INP_WUNLOCK(inp); 1199 } 1200 INP_INFO_WUNLOCK(&V_tcbinfo); 1201 CURVNET_RESTORE(); 1202 } 1203 VNET_LIST_RUNLOCK(); 1204 1205 return (0); 1206 } 1207 1208 /* 1209 * Drop a TCP connection, reporting 1210 * the specified error. If connection is synchronized, 1211 * then send a RST to peer. 1212 */ 1213 struct tcpcb * 1214 tcp_drop(struct tcpcb *tp, int errno) 1215 { 1216 struct socket *so = tp->t_inpcb->inp_socket; 1217 1218 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1219 INP_WLOCK_ASSERT(tp->t_inpcb); 1220 1221 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1222 tcp_state_change(tp, TCPS_CLOSED); 1223 (void) tp->t_fb->tfb_tcp_output(tp); 1224 TCPSTAT_INC(tcps_drops); 1225 } else 1226 TCPSTAT_INC(tcps_conndrops); 1227 if (errno == ETIMEDOUT && tp->t_softerror) 1228 errno = tp->t_softerror; 1229 so->so_error = errno; 1230 return (tcp_close(tp)); 1231 } 1232 1233 void 1234 tcp_discardcb(struct tcpcb *tp) 1235 { 1236 struct inpcb *inp = tp->t_inpcb; 1237 struct socket *so = inp->inp_socket; 1238 #ifdef INET6 1239 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1240 #endif /* INET6 */ 1241 int released; 1242 1243 INP_WLOCK_ASSERT(inp); 1244 1245 /* 1246 * Make sure that all of our timers are stopped before we delete the 1247 * PCB. 1248 * 1249 * If stopping a timer fails, we schedule a discard function in same 1250 * callout, and the last discard function called will take care of 1251 * deleting the tcpcb. 1252 */ 1253 tcp_timer_stop(tp, TT_REXMT); 1254 tcp_timer_stop(tp, TT_PERSIST); 1255 tcp_timer_stop(tp, TT_KEEP); 1256 tcp_timer_stop(tp, TT_2MSL); 1257 tcp_timer_stop(tp, TT_DELACK); 1258 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1259 /* Call the stop-all function of the methods */ 1260 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1261 } 1262 1263 /* 1264 * If we got enough samples through the srtt filter, 1265 * save the rtt and rttvar in the routing entry. 1266 * 'Enough' is arbitrarily defined as 4 rtt samples. 1267 * 4 samples is enough for the srtt filter to converge 1268 * to within enough % of the correct value; fewer samples 1269 * and we could save a bogus rtt. The danger is not high 1270 * as tcp quickly recovers from everything. 1271 * XXX: Works very well but needs some more statistics! 1272 */ 1273 if (tp->t_rttupdated >= 4) { 1274 struct hc_metrics_lite metrics; 1275 u_long ssthresh; 1276 1277 bzero(&metrics, sizeof(metrics)); 1278 /* 1279 * Update the ssthresh always when the conditions below 1280 * are satisfied. This gives us better new start value 1281 * for the congestion avoidance for new connections. 1282 * ssthresh is only set if packet loss occured on a session. 1283 * 1284 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1285 * being torn down. Ideally this code would not use 'so'. 1286 */ 1287 ssthresh = tp->snd_ssthresh; 1288 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1289 /* 1290 * convert the limit from user data bytes to 1291 * packets then to packet data bytes. 1292 */ 1293 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1294 if (ssthresh < 2) 1295 ssthresh = 2; 1296 ssthresh *= (u_long)(tp->t_maxseg + 1297 #ifdef INET6 1298 (isipv6 ? sizeof (struct ip6_hdr) + 1299 sizeof (struct tcphdr) : 1300 #endif 1301 sizeof (struct tcpiphdr) 1302 #ifdef INET6 1303 ) 1304 #endif 1305 ); 1306 } else 1307 ssthresh = 0; 1308 metrics.rmx_ssthresh = ssthresh; 1309 1310 metrics.rmx_rtt = tp->t_srtt; 1311 metrics.rmx_rttvar = tp->t_rttvar; 1312 metrics.rmx_cwnd = tp->snd_cwnd; 1313 metrics.rmx_sendpipe = 0; 1314 metrics.rmx_recvpipe = 0; 1315 1316 tcp_hc_update(&inp->inp_inc, &metrics); 1317 } 1318 1319 /* free the reassembly queue, if any */ 1320 tcp_reass_flush(tp); 1321 1322 #ifdef TCP_OFFLOAD 1323 /* Disconnect offload device, if any. */ 1324 if (tp->t_flags & TF_TOE) 1325 tcp_offload_detach(tp); 1326 #endif 1327 1328 tcp_free_sackholes(tp); 1329 1330 #ifdef TCPPCAP 1331 /* Free the TCP PCAP queues. */ 1332 tcp_pcap_drain(&(tp->t_inpkts)); 1333 tcp_pcap_drain(&(tp->t_outpkts)); 1334 #endif 1335 1336 /* Allow the CC algorithm to clean up after itself. */ 1337 if (CC_ALGO(tp)->cb_destroy != NULL) 1338 CC_ALGO(tp)->cb_destroy(tp->ccv); 1339 1340 khelp_destroy_osd(tp->osd); 1341 1342 CC_ALGO(tp) = NULL; 1343 inp->inp_ppcb = NULL; 1344 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1345 /* We own the last reference on tcpcb, let's free it. */ 1346 if ((tp->t_fb->tfb_tcp_timers_left) && 1347 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1348 /* Some fb timers left running! */ 1349 return; 1350 } 1351 if (tp->t_fb->tfb_tcp_fb_fini) 1352 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1353 refcount_release(&tp->t_fb->tfb_refcnt); 1354 tp->t_inpcb = NULL; 1355 uma_zfree(V_tcpcb_zone, tp); 1356 released = in_pcbrele_wlocked(inp); 1357 KASSERT(!released, ("%s: inp %p should not have been released " 1358 "here", __func__, inp)); 1359 } 1360 } 1361 1362 void 1363 tcp_timer_2msl_discard(void *xtp) 1364 { 1365 1366 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1367 } 1368 1369 void 1370 tcp_timer_keep_discard(void *xtp) 1371 { 1372 1373 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1374 } 1375 1376 void 1377 tcp_timer_persist_discard(void *xtp) 1378 { 1379 1380 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1381 } 1382 1383 void 1384 tcp_timer_rexmt_discard(void *xtp) 1385 { 1386 1387 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1388 } 1389 1390 void 1391 tcp_timer_delack_discard(void *xtp) 1392 { 1393 1394 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1395 } 1396 1397 void 1398 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1399 { 1400 struct inpcb *inp; 1401 1402 CURVNET_SET(tp->t_vnet); 1403 INP_INFO_RLOCK(&V_tcbinfo); 1404 inp = tp->t_inpcb; 1405 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1406 __func__, tp)); 1407 INP_WLOCK(inp); 1408 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1409 ("%s: tcpcb has to be stopped here", __func__)); 1410 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1411 ("%s: discard callout should be running", __func__)); 1412 tp->t_timers->tt_flags &= ~timer_type; 1413 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1414 /* We own the last reference on this tcpcb, let's free it. */ 1415 if ((tp->t_fb->tfb_tcp_timers_left) && 1416 (tp->t_fb->tfb_tcp_timers_left(tp))) { 1417 /* Some fb timers left running! */ 1418 goto leave; 1419 } 1420 if (tp->t_fb->tfb_tcp_fb_fini) 1421 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1422 refcount_release(&tp->t_fb->tfb_refcnt); 1423 tp->t_inpcb = NULL; 1424 uma_zfree(V_tcpcb_zone, tp); 1425 if (in_pcbrele_wlocked(inp)) { 1426 INP_INFO_RUNLOCK(&V_tcbinfo); 1427 CURVNET_RESTORE(); 1428 return; 1429 } 1430 } 1431 leave: 1432 INP_WUNLOCK(inp); 1433 INP_INFO_RUNLOCK(&V_tcbinfo); 1434 CURVNET_RESTORE(); 1435 } 1436 1437 /* 1438 * Attempt to close a TCP control block, marking it as dropped, and freeing 1439 * the socket if we hold the only reference. 1440 */ 1441 struct tcpcb * 1442 tcp_close(struct tcpcb *tp) 1443 { 1444 struct inpcb *inp = tp->t_inpcb; 1445 struct socket *so; 1446 1447 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1448 INP_WLOCK_ASSERT(inp); 1449 1450 #ifdef TCP_OFFLOAD 1451 if (tp->t_state == TCPS_LISTEN) 1452 tcp_offload_listen_stop(tp); 1453 #endif 1454 #ifdef TCP_RFC7413 1455 /* 1456 * This releases the TFO pending counter resource for TFO listen 1457 * sockets as well as passively-created TFO sockets that transition 1458 * from SYN_RECEIVED to CLOSED. 1459 */ 1460 if (tp->t_tfo_pending) { 1461 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1462 tp->t_tfo_pending = NULL; 1463 } 1464 #endif 1465 in_pcbdrop(inp); 1466 TCPSTAT_INC(tcps_closed); 1467 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1468 so = inp->inp_socket; 1469 soisdisconnected(so); 1470 if (inp->inp_flags & INP_SOCKREF) { 1471 KASSERT(so->so_state & SS_PROTOREF, 1472 ("tcp_close: !SS_PROTOREF")); 1473 inp->inp_flags &= ~INP_SOCKREF; 1474 INP_WUNLOCK(inp); 1475 ACCEPT_LOCK(); 1476 SOCK_LOCK(so); 1477 so->so_state &= ~SS_PROTOREF; 1478 sofree(so); 1479 return (NULL); 1480 } 1481 return (tp); 1482 } 1483 1484 void 1485 tcp_drain(void) 1486 { 1487 VNET_ITERATOR_DECL(vnet_iter); 1488 1489 if (!do_tcpdrain) 1490 return; 1491 1492 VNET_LIST_RLOCK_NOSLEEP(); 1493 VNET_FOREACH(vnet_iter) { 1494 CURVNET_SET(vnet_iter); 1495 struct inpcb *inpb; 1496 struct tcpcb *tcpb; 1497 1498 /* 1499 * Walk the tcpbs, if existing, and flush the reassembly queue, 1500 * if there is one... 1501 * XXX: The "Net/3" implementation doesn't imply that the TCP 1502 * reassembly queue should be flushed, but in a situation 1503 * where we're really low on mbufs, this is potentially 1504 * useful. 1505 */ 1506 INP_INFO_WLOCK(&V_tcbinfo); 1507 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1508 if (inpb->inp_flags & INP_TIMEWAIT) 1509 continue; 1510 INP_WLOCK(inpb); 1511 if ((tcpb = intotcpcb(inpb)) != NULL) { 1512 tcp_reass_flush(tcpb); 1513 tcp_clean_sackreport(tcpb); 1514 } 1515 INP_WUNLOCK(inpb); 1516 } 1517 INP_INFO_WUNLOCK(&V_tcbinfo); 1518 CURVNET_RESTORE(); 1519 } 1520 VNET_LIST_RUNLOCK_NOSLEEP(); 1521 } 1522 1523 /* 1524 * Notify a tcp user of an asynchronous error; 1525 * store error as soft error, but wake up user 1526 * (for now, won't do anything until can select for soft error). 1527 * 1528 * Do not wake up user since there currently is no mechanism for 1529 * reporting soft errors (yet - a kqueue filter may be added). 1530 */ 1531 static struct inpcb * 1532 tcp_notify(struct inpcb *inp, int error) 1533 { 1534 struct tcpcb *tp; 1535 1536 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1537 INP_WLOCK_ASSERT(inp); 1538 1539 if ((inp->inp_flags & INP_TIMEWAIT) || 1540 (inp->inp_flags & INP_DROPPED)) 1541 return (inp); 1542 1543 tp = intotcpcb(inp); 1544 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1545 1546 /* 1547 * Ignore some errors if we are hooked up. 1548 * If connection hasn't completed, has retransmitted several times, 1549 * and receives a second error, give up now. This is better 1550 * than waiting a long time to establish a connection that 1551 * can never complete. 1552 */ 1553 if (tp->t_state == TCPS_ESTABLISHED && 1554 (error == EHOSTUNREACH || error == ENETUNREACH || 1555 error == EHOSTDOWN)) { 1556 return (inp); 1557 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1558 tp->t_softerror) { 1559 tp = tcp_drop(tp, error); 1560 if (tp != NULL) 1561 return (inp); 1562 else 1563 return (NULL); 1564 } else { 1565 tp->t_softerror = error; 1566 return (inp); 1567 } 1568 #if 0 1569 wakeup( &so->so_timeo); 1570 sorwakeup(so); 1571 sowwakeup(so); 1572 #endif 1573 } 1574 1575 static int 1576 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1577 { 1578 int error, i, m, n, pcb_count; 1579 struct inpcb *inp, **inp_list; 1580 inp_gen_t gencnt; 1581 struct xinpgen xig; 1582 1583 /* 1584 * The process of preparing the TCB list is too time-consuming and 1585 * resource-intensive to repeat twice on every request. 1586 */ 1587 if (req->oldptr == NULL) { 1588 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1589 n += imax(n / 8, 10); 1590 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1591 return (0); 1592 } 1593 1594 if (req->newptr != NULL) 1595 return (EPERM); 1596 1597 /* 1598 * OK, now we're committed to doing something. 1599 */ 1600 INP_LIST_RLOCK(&V_tcbinfo); 1601 gencnt = V_tcbinfo.ipi_gencnt; 1602 n = V_tcbinfo.ipi_count; 1603 INP_LIST_RUNLOCK(&V_tcbinfo); 1604 1605 m = syncache_pcbcount(); 1606 1607 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1608 + (n + m) * sizeof(struct xtcpcb)); 1609 if (error != 0) 1610 return (error); 1611 1612 xig.xig_len = sizeof xig; 1613 xig.xig_count = n + m; 1614 xig.xig_gen = gencnt; 1615 xig.xig_sogen = so_gencnt; 1616 error = SYSCTL_OUT(req, &xig, sizeof xig); 1617 if (error) 1618 return (error); 1619 1620 error = syncache_pcblist(req, m, &pcb_count); 1621 if (error) 1622 return (error); 1623 1624 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1625 if (inp_list == NULL) 1626 return (ENOMEM); 1627 1628 INP_INFO_WLOCK(&V_tcbinfo); 1629 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1630 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1631 INP_WLOCK(inp); 1632 if (inp->inp_gencnt <= gencnt) { 1633 /* 1634 * XXX: This use of cr_cansee(), introduced with 1635 * TCP state changes, is not quite right, but for 1636 * now, better than nothing. 1637 */ 1638 if (inp->inp_flags & INP_TIMEWAIT) { 1639 if (intotw(inp) != NULL) 1640 error = cr_cansee(req->td->td_ucred, 1641 intotw(inp)->tw_cred); 1642 else 1643 error = EINVAL; /* Skip this inp. */ 1644 } else 1645 error = cr_canseeinpcb(req->td->td_ucred, inp); 1646 if (error == 0) { 1647 in_pcbref(inp); 1648 inp_list[i++] = inp; 1649 } 1650 } 1651 INP_WUNLOCK(inp); 1652 } 1653 INP_INFO_WUNLOCK(&V_tcbinfo); 1654 n = i; 1655 1656 error = 0; 1657 for (i = 0; i < n; i++) { 1658 inp = inp_list[i]; 1659 INP_RLOCK(inp); 1660 if (inp->inp_gencnt <= gencnt) { 1661 struct xtcpcb xt; 1662 void *inp_ppcb; 1663 1664 bzero(&xt, sizeof(xt)); 1665 xt.xt_len = sizeof xt; 1666 /* XXX should avoid extra copy */ 1667 bcopy(inp, &xt.xt_inp, sizeof *inp); 1668 inp_ppcb = inp->inp_ppcb; 1669 if (inp_ppcb == NULL) 1670 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1671 else if (inp->inp_flags & INP_TIMEWAIT) { 1672 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1673 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1674 } else { 1675 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1676 if (xt.xt_tp.t_timers) 1677 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1678 } 1679 if (inp->inp_socket != NULL) 1680 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1681 else { 1682 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1683 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1684 } 1685 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1686 INP_RUNLOCK(inp); 1687 error = SYSCTL_OUT(req, &xt, sizeof xt); 1688 } else 1689 INP_RUNLOCK(inp); 1690 } 1691 INP_INFO_RLOCK(&V_tcbinfo); 1692 for (i = 0; i < n; i++) { 1693 inp = inp_list[i]; 1694 INP_RLOCK(inp); 1695 if (!in_pcbrele_rlocked(inp)) 1696 INP_RUNLOCK(inp); 1697 } 1698 INP_INFO_RUNLOCK(&V_tcbinfo); 1699 1700 if (!error) { 1701 /* 1702 * Give the user an updated idea of our state. 1703 * If the generation differs from what we told 1704 * her before, she knows that something happened 1705 * while we were processing this request, and it 1706 * might be necessary to retry. 1707 */ 1708 INP_LIST_RLOCK(&V_tcbinfo); 1709 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1710 xig.xig_sogen = so_gencnt; 1711 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1712 INP_LIST_RUNLOCK(&V_tcbinfo); 1713 error = SYSCTL_OUT(req, &xig, sizeof xig); 1714 } 1715 free(inp_list, M_TEMP); 1716 return (error); 1717 } 1718 1719 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1720 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1721 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1722 1723 #ifdef INET 1724 static int 1725 tcp_getcred(SYSCTL_HANDLER_ARGS) 1726 { 1727 struct xucred xuc; 1728 struct sockaddr_in addrs[2]; 1729 struct inpcb *inp; 1730 int error; 1731 1732 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1733 if (error) 1734 return (error); 1735 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1736 if (error) 1737 return (error); 1738 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1739 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1740 if (inp != NULL) { 1741 if (inp->inp_socket == NULL) 1742 error = ENOENT; 1743 if (error == 0) 1744 error = cr_canseeinpcb(req->td->td_ucred, inp); 1745 if (error == 0) 1746 cru2x(inp->inp_cred, &xuc); 1747 INP_RUNLOCK(inp); 1748 } else 1749 error = ENOENT; 1750 if (error == 0) 1751 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1752 return (error); 1753 } 1754 1755 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1756 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1757 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1758 #endif /* INET */ 1759 1760 #ifdef INET6 1761 static int 1762 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1763 { 1764 struct xucred xuc; 1765 struct sockaddr_in6 addrs[2]; 1766 struct inpcb *inp; 1767 int error; 1768 #ifdef INET 1769 int mapped = 0; 1770 #endif 1771 1772 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1773 if (error) 1774 return (error); 1775 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1776 if (error) 1777 return (error); 1778 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1779 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1780 return (error); 1781 } 1782 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1783 #ifdef INET 1784 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1785 mapped = 1; 1786 else 1787 #endif 1788 return (EINVAL); 1789 } 1790 1791 #ifdef INET 1792 if (mapped == 1) 1793 inp = in_pcblookup(&V_tcbinfo, 1794 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1795 addrs[1].sin6_port, 1796 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1797 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1798 else 1799 #endif 1800 inp = in6_pcblookup(&V_tcbinfo, 1801 &addrs[1].sin6_addr, addrs[1].sin6_port, 1802 &addrs[0].sin6_addr, addrs[0].sin6_port, 1803 INPLOOKUP_RLOCKPCB, NULL); 1804 if (inp != NULL) { 1805 if (inp->inp_socket == NULL) 1806 error = ENOENT; 1807 if (error == 0) 1808 error = cr_canseeinpcb(req->td->td_ucred, inp); 1809 if (error == 0) 1810 cru2x(inp->inp_cred, &xuc); 1811 INP_RUNLOCK(inp); 1812 } else 1813 error = ENOENT; 1814 if (error == 0) 1815 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1816 return (error); 1817 } 1818 1819 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1820 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1821 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1822 #endif /* INET6 */ 1823 1824 1825 #ifdef INET 1826 void 1827 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1828 { 1829 struct ip *ip = vip; 1830 struct tcphdr *th; 1831 struct in_addr faddr; 1832 struct inpcb *inp; 1833 struct tcpcb *tp; 1834 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1835 struct icmp *icp; 1836 struct in_conninfo inc; 1837 tcp_seq icmp_tcp_seq; 1838 int mtu; 1839 1840 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1841 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1842 return; 1843 1844 if (cmd == PRC_MSGSIZE) 1845 notify = tcp_mtudisc_notify; 1846 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1847 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1848 notify = tcp_drop_syn_sent; 1849 /* 1850 * Redirects don't need to be handled up here. 1851 */ 1852 else if (PRC_IS_REDIRECT(cmd)) 1853 return; 1854 /* 1855 * Hostdead is ugly because it goes linearly through all PCBs. 1856 * XXX: We never get this from ICMP, otherwise it makes an 1857 * excellent DoS attack on machines with many connections. 1858 */ 1859 else if (cmd == PRC_HOSTDEAD) 1860 ip = NULL; 1861 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1862 return; 1863 1864 if (ip == NULL) { 1865 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1866 return; 1867 } 1868 1869 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1870 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1871 INP_INFO_RLOCK(&V_tcbinfo); 1872 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1873 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1874 if (inp != NULL) { 1875 if (!(inp->inp_flags & INP_TIMEWAIT) && 1876 !(inp->inp_flags & INP_DROPPED) && 1877 !(inp->inp_socket == NULL)) { 1878 icmp_tcp_seq = ntohl(th->th_seq); 1879 tp = intotcpcb(inp); 1880 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1881 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1882 if (cmd == PRC_MSGSIZE) { 1883 /* 1884 * MTU discovery: 1885 * If we got a needfrag set the MTU 1886 * in the route to the suggested new 1887 * value (if given) and then notify. 1888 */ 1889 mtu = ntohs(icp->icmp_nextmtu); 1890 /* 1891 * If no alternative MTU was 1892 * proposed, try the next smaller 1893 * one. 1894 */ 1895 if (!mtu) 1896 mtu = ip_next_mtu( 1897 ntohs(ip->ip_len), 1); 1898 if (mtu < V_tcp_minmss + 1899 sizeof(struct tcpiphdr)) 1900 mtu = V_tcp_minmss + 1901 sizeof(struct tcpiphdr); 1902 /* 1903 * Only process the offered MTU if it 1904 * is smaller than the current one. 1905 */ 1906 if (mtu < tp->t_maxseg + 1907 sizeof(struct tcpiphdr)) { 1908 bzero(&inc, sizeof(inc)); 1909 inc.inc_faddr = faddr; 1910 inc.inc_fibnum = 1911 inp->inp_inc.inc_fibnum; 1912 tcp_hc_updatemtu(&inc, mtu); 1913 tcp_mtudisc(inp, mtu); 1914 } 1915 } else 1916 inp = (*notify)(inp, 1917 inetctlerrmap[cmd]); 1918 } 1919 } 1920 if (inp != NULL) 1921 INP_WUNLOCK(inp); 1922 } else { 1923 bzero(&inc, sizeof(inc)); 1924 inc.inc_fport = th->th_dport; 1925 inc.inc_lport = th->th_sport; 1926 inc.inc_faddr = faddr; 1927 inc.inc_laddr = ip->ip_src; 1928 syncache_unreach(&inc, th); 1929 } 1930 INP_INFO_RUNLOCK(&V_tcbinfo); 1931 } 1932 #endif /* INET */ 1933 1934 #ifdef INET6 1935 void 1936 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1937 { 1938 struct tcphdr th; 1939 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1940 struct ip6_hdr *ip6; 1941 struct mbuf *m; 1942 struct ip6ctlparam *ip6cp = NULL; 1943 const struct sockaddr_in6 *sa6_src = NULL; 1944 int off; 1945 struct tcp_portonly { 1946 u_int16_t th_sport; 1947 u_int16_t th_dport; 1948 } *thp; 1949 1950 if (sa->sa_family != AF_INET6 || 1951 sa->sa_len != sizeof(struct sockaddr_in6)) 1952 return; 1953 1954 if (cmd == PRC_MSGSIZE) 1955 notify = tcp_mtudisc_notify; 1956 else if (!PRC_IS_REDIRECT(cmd) && 1957 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1958 return; 1959 1960 /* if the parameter is from icmp6, decode it. */ 1961 if (d != NULL) { 1962 ip6cp = (struct ip6ctlparam *)d; 1963 m = ip6cp->ip6c_m; 1964 ip6 = ip6cp->ip6c_ip6; 1965 off = ip6cp->ip6c_off; 1966 sa6_src = ip6cp->ip6c_src; 1967 } else { 1968 m = NULL; 1969 ip6 = NULL; 1970 off = 0; /* fool gcc */ 1971 sa6_src = &sa6_any; 1972 } 1973 1974 if (ip6 != NULL) { 1975 struct in_conninfo inc; 1976 /* 1977 * XXX: We assume that when IPV6 is non NULL, 1978 * M and OFF are valid. 1979 */ 1980 1981 /* check if we can safely examine src and dst ports */ 1982 if (m->m_pkthdr.len < off + sizeof(*thp)) 1983 return; 1984 1985 bzero(&th, sizeof(th)); 1986 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1987 1988 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1989 (struct sockaddr *)ip6cp->ip6c_src, 1990 th.th_sport, cmd, NULL, notify); 1991 1992 bzero(&inc, sizeof(inc)); 1993 inc.inc_fport = th.th_dport; 1994 inc.inc_lport = th.th_sport; 1995 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1996 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1997 inc.inc_flags |= INC_ISIPV6; 1998 INP_INFO_RLOCK(&V_tcbinfo); 1999 syncache_unreach(&inc, &th); 2000 INP_INFO_RUNLOCK(&V_tcbinfo); 2001 } else 2002 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 2003 0, cmd, NULL, notify); 2004 } 2005 #endif /* INET6 */ 2006 2007 2008 /* 2009 * Following is where TCP initial sequence number generation occurs. 2010 * 2011 * There are two places where we must use initial sequence numbers: 2012 * 1. In SYN-ACK packets. 2013 * 2. In SYN packets. 2014 * 2015 * All ISNs for SYN-ACK packets are generated by the syncache. See 2016 * tcp_syncache.c for details. 2017 * 2018 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2019 * depends on this property. In addition, these ISNs should be 2020 * unguessable so as to prevent connection hijacking. To satisfy 2021 * the requirements of this situation, the algorithm outlined in 2022 * RFC 1948 is used, with only small modifications. 2023 * 2024 * Implementation details: 2025 * 2026 * Time is based off the system timer, and is corrected so that it 2027 * increases by one megabyte per second. This allows for proper 2028 * recycling on high speed LANs while still leaving over an hour 2029 * before rollover. 2030 * 2031 * As reading the *exact* system time is too expensive to be done 2032 * whenever setting up a TCP connection, we increment the time 2033 * offset in two ways. First, a small random positive increment 2034 * is added to isn_offset for each connection that is set up. 2035 * Second, the function tcp_isn_tick fires once per clock tick 2036 * and increments isn_offset as necessary so that sequence numbers 2037 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2038 * random positive increments serve only to ensure that the same 2039 * exact sequence number is never sent out twice (as could otherwise 2040 * happen when a port is recycled in less than the system tick 2041 * interval.) 2042 * 2043 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2044 * between seeding of isn_secret. This is normally set to zero, 2045 * as reseeding should not be necessary. 2046 * 2047 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2048 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2049 * general, this means holding an exclusive (write) lock. 2050 */ 2051 2052 #define ISN_BYTES_PER_SECOND 1048576 2053 #define ISN_STATIC_INCREMENT 4096 2054 #define ISN_RANDOM_INCREMENT (4096 - 1) 2055 2056 static VNET_DEFINE(u_char, isn_secret[32]); 2057 static VNET_DEFINE(int, isn_last); 2058 static VNET_DEFINE(int, isn_last_reseed); 2059 static VNET_DEFINE(u_int32_t, isn_offset); 2060 static VNET_DEFINE(u_int32_t, isn_offset_old); 2061 2062 #define V_isn_secret VNET(isn_secret) 2063 #define V_isn_last VNET(isn_last) 2064 #define V_isn_last_reseed VNET(isn_last_reseed) 2065 #define V_isn_offset VNET(isn_offset) 2066 #define V_isn_offset_old VNET(isn_offset_old) 2067 2068 tcp_seq 2069 tcp_new_isn(struct tcpcb *tp) 2070 { 2071 MD5_CTX isn_ctx; 2072 u_int32_t md5_buffer[4]; 2073 tcp_seq new_isn; 2074 u_int32_t projected_offset; 2075 2076 INP_WLOCK_ASSERT(tp->t_inpcb); 2077 2078 ISN_LOCK(); 2079 /* Seed if this is the first use, reseed if requested. */ 2080 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2081 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2082 < (u_int)ticks))) { 2083 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2084 V_isn_last_reseed = ticks; 2085 } 2086 2087 /* Compute the md5 hash and return the ISN. */ 2088 MD5Init(&isn_ctx); 2089 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2090 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2091 #ifdef INET6 2092 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2093 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2094 sizeof(struct in6_addr)); 2095 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2096 sizeof(struct in6_addr)); 2097 } else 2098 #endif 2099 { 2100 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2101 sizeof(struct in_addr)); 2102 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2103 sizeof(struct in_addr)); 2104 } 2105 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2106 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2107 new_isn = (tcp_seq) md5_buffer[0]; 2108 V_isn_offset += ISN_STATIC_INCREMENT + 2109 (arc4random() & ISN_RANDOM_INCREMENT); 2110 if (ticks != V_isn_last) { 2111 projected_offset = V_isn_offset_old + 2112 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2113 if (SEQ_GT(projected_offset, V_isn_offset)) 2114 V_isn_offset = projected_offset; 2115 V_isn_offset_old = V_isn_offset; 2116 V_isn_last = ticks; 2117 } 2118 new_isn += V_isn_offset; 2119 ISN_UNLOCK(); 2120 return (new_isn); 2121 } 2122 2123 /* 2124 * When a specific ICMP unreachable message is received and the 2125 * connection state is SYN-SENT, drop the connection. This behavior 2126 * is controlled by the icmp_may_rst sysctl. 2127 */ 2128 struct inpcb * 2129 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2130 { 2131 struct tcpcb *tp; 2132 2133 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2134 INP_WLOCK_ASSERT(inp); 2135 2136 if ((inp->inp_flags & INP_TIMEWAIT) || 2137 (inp->inp_flags & INP_DROPPED)) 2138 return (inp); 2139 2140 tp = intotcpcb(inp); 2141 if (tp->t_state != TCPS_SYN_SENT) 2142 return (inp); 2143 2144 tp = tcp_drop(tp, errno); 2145 if (tp != NULL) 2146 return (inp); 2147 else 2148 return (NULL); 2149 } 2150 2151 /* 2152 * When `need fragmentation' ICMP is received, update our idea of the MSS 2153 * based on the new value. Also nudge TCP to send something, since we 2154 * know the packet we just sent was dropped. 2155 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2156 */ 2157 static struct inpcb * 2158 tcp_mtudisc_notify(struct inpcb *inp, int error) 2159 { 2160 2161 tcp_mtudisc(inp, -1); 2162 return (inp); 2163 } 2164 2165 static void 2166 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2167 { 2168 struct tcpcb *tp; 2169 struct socket *so; 2170 2171 INP_WLOCK_ASSERT(inp); 2172 if ((inp->inp_flags & INP_TIMEWAIT) || 2173 (inp->inp_flags & INP_DROPPED)) 2174 return; 2175 2176 tp = intotcpcb(inp); 2177 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2178 2179 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2180 2181 so = inp->inp_socket; 2182 SOCKBUF_LOCK(&so->so_snd); 2183 /* If the mss is larger than the socket buffer, decrease the mss. */ 2184 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2185 tp->t_maxseg = so->so_snd.sb_hiwat; 2186 SOCKBUF_UNLOCK(&so->so_snd); 2187 2188 TCPSTAT_INC(tcps_mturesent); 2189 tp->t_rtttime = 0; 2190 tp->snd_nxt = tp->snd_una; 2191 tcp_free_sackholes(tp); 2192 tp->snd_recover = tp->snd_max; 2193 if (tp->t_flags & TF_SACK_PERMIT) 2194 EXIT_FASTRECOVERY(tp->t_flags); 2195 tp->t_fb->tfb_tcp_output(tp); 2196 } 2197 2198 #ifdef INET 2199 /* 2200 * Look-up the routing entry to the peer of this inpcb. If no route 2201 * is found and it cannot be allocated, then return 0. This routine 2202 * is called by TCP routines that access the rmx structure and by 2203 * tcp_mss_update to get the peer/interface MTU. 2204 */ 2205 u_long 2206 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2207 { 2208 struct route sro; 2209 struct sockaddr_in *dst; 2210 struct ifnet *ifp; 2211 u_long maxmtu = 0; 2212 2213 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2214 2215 bzero(&sro, sizeof(sro)); 2216 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2217 dst = (struct sockaddr_in *)&sro.ro_dst; 2218 dst->sin_family = AF_INET; 2219 dst->sin_len = sizeof(*dst); 2220 dst->sin_addr = inc->inc_faddr; 2221 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 2222 } 2223 if (sro.ro_rt != NULL) { 2224 ifp = sro.ro_rt->rt_ifp; 2225 if (sro.ro_rt->rt_mtu == 0) 2226 maxmtu = ifp->if_mtu; 2227 else 2228 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 2229 2230 /* Report additional interface capabilities. */ 2231 if (cap != NULL) { 2232 if (ifp->if_capenable & IFCAP_TSO4 && 2233 ifp->if_hwassist & CSUM_TSO) { 2234 cap->ifcap |= CSUM_TSO; 2235 cap->tsomax = ifp->if_hw_tsomax; 2236 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2237 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2238 } 2239 } 2240 RTFREE(sro.ro_rt); 2241 } 2242 return (maxmtu); 2243 } 2244 #endif /* INET */ 2245 2246 #ifdef INET6 2247 u_long 2248 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2249 { 2250 struct route_in6 sro6; 2251 struct ifnet *ifp; 2252 u_long maxmtu = 0; 2253 2254 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2255 2256 bzero(&sro6, sizeof(sro6)); 2257 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2258 sro6.ro_dst.sin6_family = AF_INET6; 2259 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 2260 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 2261 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 2262 } 2263 if (sro6.ro_rt != NULL) { 2264 ifp = sro6.ro_rt->rt_ifp; 2265 if (sro6.ro_rt->rt_mtu == 0) 2266 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 2267 else 2268 maxmtu = min(sro6.ro_rt->rt_mtu, 2269 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 2270 2271 /* Report additional interface capabilities. */ 2272 if (cap != NULL) { 2273 if (ifp->if_capenable & IFCAP_TSO6 && 2274 ifp->if_hwassist & CSUM_TSO) { 2275 cap->ifcap |= CSUM_TSO; 2276 cap->tsomax = ifp->if_hw_tsomax; 2277 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2278 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2279 } 2280 } 2281 RTFREE(sro6.ro_rt); 2282 } 2283 2284 return (maxmtu); 2285 } 2286 #endif /* INET6 */ 2287 2288 /* 2289 * Calculate effective SMSS per RFC5681 definition for a given TCP 2290 * connection at its current state, taking into account SACK and etc. 2291 */ 2292 u_int 2293 tcp_maxseg(const struct tcpcb *tp) 2294 { 2295 u_int optlen; 2296 2297 if (tp->t_flags & TF_NOOPT) 2298 return (tp->t_maxseg); 2299 2300 /* 2301 * Here we have a simplified code from tcp_addoptions(), 2302 * without a proper loop, and having most of paddings hardcoded. 2303 * We might make mistakes with padding here in some edge cases, 2304 * but this is harmless, since result of tcp_maxseg() is used 2305 * only in cwnd and ssthresh estimations. 2306 */ 2307 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2308 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2309 if (tp->t_flags & TF_RCVD_TSTMP) 2310 optlen = TCPOLEN_TSTAMP_APPA; 2311 else 2312 optlen = 0; 2313 #ifdef TCP_SIGNATURE 2314 if (tp->t_flags & TF_SIGNATURE) 2315 optlen += PAD(TCPOLEN_SIGNATURE); 2316 #endif 2317 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2318 optlen += TCPOLEN_SACKHDR; 2319 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2320 optlen = PAD(optlen); 2321 } 2322 } else { 2323 if (tp->t_flags & TF_REQ_TSTMP) 2324 optlen = TCPOLEN_TSTAMP_APPA; 2325 else 2326 optlen = PAD(TCPOLEN_MAXSEG); 2327 if (tp->t_flags & TF_REQ_SCALE) 2328 optlen += PAD(TCPOLEN_WINDOW); 2329 #ifdef TCP_SIGNATURE 2330 if (tp->t_flags & TF_SIGNATURE) 2331 optlen += PAD(TCPOLEN_SIGNATURE); 2332 #endif 2333 if (tp->t_flags & TF_SACK_PERMIT) 2334 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2335 } 2336 #undef PAD 2337 optlen = min(optlen, TCP_MAXOLEN); 2338 return (tp->t_maxseg - optlen); 2339 } 2340 2341 #ifdef IPSEC 2342 /* compute ESP/AH header size for TCP, including outer IP header. */ 2343 size_t 2344 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2345 { 2346 struct inpcb *inp; 2347 struct mbuf *m; 2348 size_t hdrsiz; 2349 struct ip *ip; 2350 #ifdef INET6 2351 struct ip6_hdr *ip6; 2352 #endif 2353 struct tcphdr *th; 2354 2355 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2356 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2357 return (0); 2358 m = m_gethdr(M_NOWAIT, MT_DATA); 2359 if (!m) 2360 return (0); 2361 2362 #ifdef INET6 2363 if ((inp->inp_vflag & INP_IPV6) != 0) { 2364 ip6 = mtod(m, struct ip6_hdr *); 2365 th = (struct tcphdr *)(ip6 + 1); 2366 m->m_pkthdr.len = m->m_len = 2367 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2368 tcpip_fillheaders(inp, ip6, th); 2369 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2370 } else 2371 #endif /* INET6 */ 2372 { 2373 ip = mtod(m, struct ip *); 2374 th = (struct tcphdr *)(ip + 1); 2375 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2376 tcpip_fillheaders(inp, ip, th); 2377 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2378 } 2379 2380 m_free(m); 2381 return (hdrsiz); 2382 } 2383 #endif /* IPSEC */ 2384 2385 #ifdef TCP_SIGNATURE 2386 /* 2387 * Callback function invoked by m_apply() to digest TCP segment data 2388 * contained within an mbuf chain. 2389 */ 2390 static int 2391 tcp_signature_apply(void *fstate, void *data, u_int len) 2392 { 2393 2394 MD5Update(fstate, (u_char *)data, len); 2395 return (0); 2396 } 2397 2398 /* 2399 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2400 * search with the destination IP address, and a 'magic SPI' to be 2401 * determined by the application. This is hardcoded elsewhere to 1179 2402 */ 2403 struct secasvar * 2404 tcp_get_sav(struct mbuf *m, u_int direction) 2405 { 2406 union sockaddr_union dst; 2407 struct secasvar *sav; 2408 struct ip *ip; 2409 #ifdef INET6 2410 struct ip6_hdr *ip6; 2411 char ip6buf[INET6_ADDRSTRLEN]; 2412 #endif 2413 2414 /* Extract the destination from the IP header in the mbuf. */ 2415 bzero(&dst, sizeof(union sockaddr_union)); 2416 ip = mtod(m, struct ip *); 2417 #ifdef INET6 2418 ip6 = NULL; /* Make the compiler happy. */ 2419 #endif 2420 switch (ip->ip_v) { 2421 #ifdef INET 2422 case IPVERSION: 2423 dst.sa.sa_len = sizeof(struct sockaddr_in); 2424 dst.sa.sa_family = AF_INET; 2425 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2426 ip->ip_src : ip->ip_dst; 2427 break; 2428 #endif 2429 #ifdef INET6 2430 case (IPV6_VERSION >> 4): 2431 ip6 = mtod(m, struct ip6_hdr *); 2432 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2433 dst.sa.sa_family = AF_INET6; 2434 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2435 ip6->ip6_src : ip6->ip6_dst; 2436 break; 2437 #endif 2438 default: 2439 return (NULL); 2440 /* NOTREACHED */ 2441 break; 2442 } 2443 2444 /* Look up an SADB entry which matches the address of the peer. */ 2445 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2446 if (sav == NULL) { 2447 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2448 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2449 #ifdef INET6 2450 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2451 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2452 #endif 2453 "(unsupported)")); 2454 } 2455 2456 return (sav); 2457 } 2458 2459 /* 2460 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2461 * 2462 * Parameters: 2463 * m pointer to head of mbuf chain 2464 * len length of TCP segment data, excluding options 2465 * optlen length of TCP segment options 2466 * buf pointer to storage for computed MD5 digest 2467 * sav pointer to security assosiation 2468 * 2469 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2470 * When called from tcp_input(), we can be sure that th_sum has been 2471 * zeroed out and verified already. 2472 * 2473 * Releases reference to SADB key before return. 2474 * 2475 * Return 0 if successful, otherwise return -1. 2476 * 2477 */ 2478 int 2479 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2480 u_char *buf, struct secasvar *sav) 2481 { 2482 #ifdef INET 2483 struct ippseudo ippseudo; 2484 #endif 2485 MD5_CTX ctx; 2486 int doff; 2487 struct ip *ip; 2488 #ifdef INET 2489 struct ipovly *ipovly; 2490 #endif 2491 struct tcphdr *th; 2492 #ifdef INET6 2493 struct ip6_hdr *ip6; 2494 struct in6_addr in6; 2495 uint32_t plen; 2496 uint16_t nhdr; 2497 #endif 2498 u_short savecsum; 2499 2500 KASSERT(m != NULL, ("NULL mbuf chain")); 2501 KASSERT(buf != NULL, ("NULL signature pointer")); 2502 2503 /* Extract the destination from the IP header in the mbuf. */ 2504 ip = mtod(m, struct ip *); 2505 #ifdef INET6 2506 ip6 = NULL; /* Make the compiler happy. */ 2507 #endif 2508 2509 MD5Init(&ctx); 2510 /* 2511 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2512 * 2513 * XXX The ippseudo header MUST be digested in network byte order, 2514 * or else we'll fail the regression test. Assume all fields we've 2515 * been doing arithmetic on have been in host byte order. 2516 * XXX One cannot depend on ipovly->ih_len here. When called from 2517 * tcp_output(), the underlying ip_len member has not yet been set. 2518 */ 2519 switch (ip->ip_v) { 2520 #ifdef INET 2521 case IPVERSION: 2522 ipovly = (struct ipovly *)ip; 2523 ippseudo.ippseudo_src = ipovly->ih_src; 2524 ippseudo.ippseudo_dst = ipovly->ih_dst; 2525 ippseudo.ippseudo_pad = 0; 2526 ippseudo.ippseudo_p = IPPROTO_TCP; 2527 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2528 optlen); 2529 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2530 2531 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2532 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2533 break; 2534 #endif 2535 #ifdef INET6 2536 /* 2537 * RFC 2385, 2.0 Proposal 2538 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2539 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2540 * extended next header value (to form 32 bits), and 32-bit segment 2541 * length. 2542 * Note: Upper-Layer Packet Length comes before Next Header. 2543 */ 2544 case (IPV6_VERSION >> 4): 2545 in6 = ip6->ip6_src; 2546 in6_clearscope(&in6); 2547 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2548 in6 = ip6->ip6_dst; 2549 in6_clearscope(&in6); 2550 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2551 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2552 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2553 nhdr = 0; 2554 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2555 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2556 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2557 nhdr = IPPROTO_TCP; 2558 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2559 2560 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2561 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2562 break; 2563 #endif 2564 default: 2565 KEY_FREESAV(&sav); 2566 return (-1); 2567 /* NOTREACHED */ 2568 break; 2569 } 2570 2571 2572 /* 2573 * Step 2: Update MD5 hash with TCP header, excluding options. 2574 * The TCP checksum must be set to zero. 2575 */ 2576 savecsum = th->th_sum; 2577 th->th_sum = 0; 2578 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2579 th->th_sum = savecsum; 2580 2581 /* 2582 * Step 3: Update MD5 hash with TCP segment data. 2583 * Use m_apply() to avoid an early m_pullup(). 2584 */ 2585 if (len > 0) 2586 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2587 2588 /* 2589 * Step 4: Update MD5 hash with shared secret. 2590 */ 2591 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2592 MD5Final(buf, &ctx); 2593 2594 key_sa_recordxfer(sav, m); 2595 KEY_FREESAV(&sav); 2596 return (0); 2597 } 2598 2599 /* 2600 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2601 * 2602 * Return 0 if successful, otherwise return -1. 2603 */ 2604 int 2605 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2606 u_char *buf, u_int direction) 2607 { 2608 struct secasvar *sav; 2609 2610 if ((sav = tcp_get_sav(m, direction)) == NULL) 2611 return (-1); 2612 2613 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2614 } 2615 2616 /* 2617 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2618 * 2619 * Parameters: 2620 * m pointer to head of mbuf chain 2621 * len length of TCP segment data, excluding options 2622 * optlen length of TCP segment options 2623 * buf pointer to storage for computed MD5 digest 2624 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2625 * 2626 * Return 1 if successful, otherwise return 0. 2627 */ 2628 int 2629 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2630 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2631 { 2632 char tmpdigest[TCP_SIGLEN]; 2633 2634 if (tcp_sig_checksigs == 0) 2635 return (1); 2636 if ((tcpbflag & TF_SIGNATURE) == 0) { 2637 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2638 2639 /* 2640 * If this socket is not expecting signature but 2641 * the segment contains signature just fail. 2642 */ 2643 TCPSTAT_INC(tcps_sig_err_sigopt); 2644 TCPSTAT_INC(tcps_sig_rcvbadsig); 2645 return (0); 2646 } 2647 2648 /* Signature is not expected, and not present in segment. */ 2649 return (1); 2650 } 2651 2652 /* 2653 * If this socket is expecting signature but the segment does not 2654 * contain any just fail. 2655 */ 2656 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2657 TCPSTAT_INC(tcps_sig_err_nosigopt); 2658 TCPSTAT_INC(tcps_sig_rcvbadsig); 2659 return (0); 2660 } 2661 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2662 IPSEC_DIR_INBOUND) == -1) { 2663 TCPSTAT_INC(tcps_sig_err_buildsig); 2664 TCPSTAT_INC(tcps_sig_rcvbadsig); 2665 return (0); 2666 } 2667 2668 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2669 TCPSTAT_INC(tcps_sig_rcvbadsig); 2670 return (0); 2671 } 2672 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2673 return (1); 2674 } 2675 #endif /* TCP_SIGNATURE */ 2676 2677 static int 2678 sysctl_drop(SYSCTL_HANDLER_ARGS) 2679 { 2680 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2681 struct sockaddr_storage addrs[2]; 2682 struct inpcb *inp; 2683 struct tcpcb *tp; 2684 struct tcptw *tw; 2685 struct sockaddr_in *fin, *lin; 2686 #ifdef INET6 2687 struct sockaddr_in6 *fin6, *lin6; 2688 #endif 2689 int error; 2690 2691 inp = NULL; 2692 fin = lin = NULL; 2693 #ifdef INET6 2694 fin6 = lin6 = NULL; 2695 #endif 2696 error = 0; 2697 2698 if (req->oldptr != NULL || req->oldlen != 0) 2699 return (EINVAL); 2700 if (req->newptr == NULL) 2701 return (EPERM); 2702 if (req->newlen < sizeof(addrs)) 2703 return (ENOMEM); 2704 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2705 if (error) 2706 return (error); 2707 2708 switch (addrs[0].ss_family) { 2709 #ifdef INET6 2710 case AF_INET6: 2711 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2712 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2713 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2714 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2715 return (EINVAL); 2716 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2717 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2718 return (EINVAL); 2719 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2720 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2721 fin = (struct sockaddr_in *)&addrs[0]; 2722 lin = (struct sockaddr_in *)&addrs[1]; 2723 break; 2724 } 2725 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2726 if (error) 2727 return (error); 2728 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2729 if (error) 2730 return (error); 2731 break; 2732 #endif 2733 #ifdef INET 2734 case AF_INET: 2735 fin = (struct sockaddr_in *)&addrs[0]; 2736 lin = (struct sockaddr_in *)&addrs[1]; 2737 if (fin->sin_len != sizeof(struct sockaddr_in) || 2738 lin->sin_len != sizeof(struct sockaddr_in)) 2739 return (EINVAL); 2740 break; 2741 #endif 2742 default: 2743 return (EINVAL); 2744 } 2745 INP_INFO_RLOCK(&V_tcbinfo); 2746 switch (addrs[0].ss_family) { 2747 #ifdef INET6 2748 case AF_INET6: 2749 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2750 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2751 INPLOOKUP_WLOCKPCB, NULL); 2752 break; 2753 #endif 2754 #ifdef INET 2755 case AF_INET: 2756 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2757 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2758 break; 2759 #endif 2760 } 2761 if (inp != NULL) { 2762 if (inp->inp_flags & INP_TIMEWAIT) { 2763 /* 2764 * XXXRW: There currently exists a state where an 2765 * inpcb is present, but its timewait state has been 2766 * discarded. For now, don't allow dropping of this 2767 * type of inpcb. 2768 */ 2769 tw = intotw(inp); 2770 if (tw != NULL) 2771 tcp_twclose(tw, 0); 2772 else 2773 INP_WUNLOCK(inp); 2774 } else if (!(inp->inp_flags & INP_DROPPED) && 2775 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2776 tp = intotcpcb(inp); 2777 tp = tcp_drop(tp, ECONNABORTED); 2778 if (tp != NULL) 2779 INP_WUNLOCK(inp); 2780 } else 2781 INP_WUNLOCK(inp); 2782 } else 2783 error = ESRCH; 2784 INP_INFO_RUNLOCK(&V_tcbinfo); 2785 return (error); 2786 } 2787 2788 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2789 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2790 0, sysctl_drop, "", "Drop TCP connection"); 2791 2792 /* 2793 * Generate a standardized TCP log line for use throughout the 2794 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2795 * allow use in the interrupt context. 2796 * 2797 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2798 * NB: The function may return NULL if memory allocation failed. 2799 * 2800 * Due to header inclusion and ordering limitations the struct ip 2801 * and ip6_hdr pointers have to be passed as void pointers. 2802 */ 2803 char * 2804 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2805 const void *ip6hdr) 2806 { 2807 2808 /* Is logging enabled? */ 2809 if (tcp_log_in_vain == 0) 2810 return (NULL); 2811 2812 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2813 } 2814 2815 char * 2816 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2817 const void *ip6hdr) 2818 { 2819 2820 /* Is logging enabled? */ 2821 if (tcp_log_debug == 0) 2822 return (NULL); 2823 2824 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2825 } 2826 2827 static char * 2828 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2829 const void *ip6hdr) 2830 { 2831 char *s, *sp; 2832 size_t size; 2833 struct ip *ip; 2834 #ifdef INET6 2835 const struct ip6_hdr *ip6; 2836 2837 ip6 = (const struct ip6_hdr *)ip6hdr; 2838 #endif /* INET6 */ 2839 ip = (struct ip *)ip4hdr; 2840 2841 /* 2842 * The log line looks like this: 2843 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2844 */ 2845 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2846 sizeof(PRINT_TH_FLAGS) + 1 + 2847 #ifdef INET6 2848 2 * INET6_ADDRSTRLEN; 2849 #else 2850 2 * INET_ADDRSTRLEN; 2851 #endif /* INET6 */ 2852 2853 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2854 if (s == NULL) 2855 return (NULL); 2856 2857 strcat(s, "TCP: ["); 2858 sp = s + strlen(s); 2859 2860 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2861 inet_ntoa_r(inc->inc_faddr, sp); 2862 sp = s + strlen(s); 2863 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2864 sp = s + strlen(s); 2865 inet_ntoa_r(inc->inc_laddr, sp); 2866 sp = s + strlen(s); 2867 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2868 #ifdef INET6 2869 } else if (inc) { 2870 ip6_sprintf(sp, &inc->inc6_faddr); 2871 sp = s + strlen(s); 2872 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2873 sp = s + strlen(s); 2874 ip6_sprintf(sp, &inc->inc6_laddr); 2875 sp = s + strlen(s); 2876 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2877 } else if (ip6 && th) { 2878 ip6_sprintf(sp, &ip6->ip6_src); 2879 sp = s + strlen(s); 2880 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2881 sp = s + strlen(s); 2882 ip6_sprintf(sp, &ip6->ip6_dst); 2883 sp = s + strlen(s); 2884 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2885 #endif /* INET6 */ 2886 #ifdef INET 2887 } else if (ip && th) { 2888 inet_ntoa_r(ip->ip_src, sp); 2889 sp = s + strlen(s); 2890 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2891 sp = s + strlen(s); 2892 inet_ntoa_r(ip->ip_dst, sp); 2893 sp = s + strlen(s); 2894 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2895 #endif /* INET */ 2896 } else { 2897 free(s, M_TCPLOG); 2898 return (NULL); 2899 } 2900 sp = s + strlen(s); 2901 if (th) 2902 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2903 if (*(s + size - 1) != '\0') 2904 panic("%s: string too long", __func__); 2905 return (s); 2906 } 2907 2908 /* 2909 * A subroutine which makes it easy to track TCP state changes with DTrace. 2910 * This function shouldn't be called for t_state initializations that don't 2911 * correspond to actual TCP state transitions. 2912 */ 2913 void 2914 tcp_state_change(struct tcpcb *tp, int newstate) 2915 { 2916 #if defined(KDTRACE_HOOKS) 2917 int pstate = tp->t_state; 2918 #endif 2919 2920 tp->t_state = newstate; 2921 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2922 } 2923