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