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/icmp6.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/in6_fib.h> 84 #include <netinet6/in6_pcb.h> 85 #include <netinet6/ip6_var.h> 86 #include <netinet6/scope6_var.h> 87 #include <netinet6/nd6.h> 88 #endif 89 90 #ifdef TCP_RFC7413 91 #include <netinet/tcp_fastopen.h> 92 #endif 93 #include <netinet/tcp.h> 94 #include <netinet/tcp_fsm.h> 95 #include <netinet/tcp_seq.h> 96 #include <netinet/tcp_timer.h> 97 #include <netinet/tcp_var.h> 98 #include <netinet/tcp_syncache.h> 99 #include <netinet/cc/cc.h> 100 #ifdef INET6 101 #include <netinet6/tcp6_var.h> 102 #endif 103 #include <netinet/tcpip.h> 104 #ifdef TCPPCAP 105 #include <netinet/tcp_pcap.h> 106 #endif 107 #ifdef TCPDEBUG 108 #include <netinet/tcp_debug.h> 109 #endif 110 #ifdef INET6 111 #include <netinet6/ip6protosw.h> 112 #endif 113 #ifdef TCP_OFFLOAD 114 #include <netinet/tcp_offload.h> 115 #endif 116 117 #ifdef IPSEC 118 #include <netipsec/ipsec.h> 119 #include <netipsec/xform.h> 120 #ifdef INET6 121 #include <netipsec/ipsec6.h> 122 #endif 123 #include <netipsec/key.h> 124 #include <sys/syslog.h> 125 #endif /*IPSEC*/ 126 127 #include <machine/in_cksum.h> 128 #include <sys/md5.h> 129 130 #include <security/mac/mac_framework.h> 131 132 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 133 #ifdef INET6 134 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 135 #endif 136 137 struct rwlock tcp_function_lock; 138 139 static int 140 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 141 { 142 int error, new; 143 144 new = V_tcp_mssdflt; 145 error = sysctl_handle_int(oidp, &new, 0, req); 146 if (error == 0 && req->newptr) { 147 if (new < TCP_MINMSS) 148 error = EINVAL; 149 else 150 V_tcp_mssdflt = new; 151 } 152 return (error); 153 } 154 155 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 156 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 157 &sysctl_net_inet_tcp_mss_check, "I", 158 "Default TCP Maximum Segment Size"); 159 160 #ifdef INET6 161 static int 162 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 163 { 164 int error, new; 165 166 new = V_tcp_v6mssdflt; 167 error = sysctl_handle_int(oidp, &new, 0, req); 168 if (error == 0 && req->newptr) { 169 if (new < TCP_MINMSS) 170 error = EINVAL; 171 else 172 V_tcp_v6mssdflt = new; 173 } 174 return (error); 175 } 176 177 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 178 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 179 &sysctl_net_inet_tcp_mss_v6_check, "I", 180 "Default TCP Maximum Segment Size for IPv6"); 181 #endif /* INET6 */ 182 183 /* 184 * Minimum MSS we accept and use. This prevents DoS attacks where 185 * we are forced to a ridiculous low MSS like 20 and send hundreds 186 * of packets instead of one. The effect scales with the available 187 * bandwidth and quickly saturates the CPU and network interface 188 * with packet generation and sending. Set to zero to disable MINMSS 189 * checking. This setting prevents us from sending too small packets. 190 */ 191 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 192 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 193 &VNET_NAME(tcp_minmss), 0, 194 "Minimum TCP Maximum Segment Size"); 195 196 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 197 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 198 &VNET_NAME(tcp_do_rfc1323), 0, 199 "Enable rfc1323 (high performance TCP) extensions"); 200 201 static int tcp_log_debug = 0; 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 203 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 204 205 static int tcp_tcbhashsize; 206 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 207 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 208 209 static int do_tcpdrain = 1; 210 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 211 "Enable tcp_drain routine for extra help when low on mbufs"); 212 213 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 214 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 215 216 static VNET_DEFINE(int, icmp_may_rst) = 1; 217 #define V_icmp_may_rst VNET(icmp_may_rst) 218 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 219 &VNET_NAME(icmp_may_rst), 0, 220 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 221 222 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 223 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 224 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 225 &VNET_NAME(tcp_isn_reseed_interval), 0, 226 "Seconds between reseeding of ISN secret"); 227 228 static int tcp_soreceive_stream; 229 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 230 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 231 232 #ifdef TCP_SIGNATURE 233 static int tcp_sig_checksigs = 1; 234 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 235 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 236 #endif 237 238 VNET_DEFINE(uma_zone_t, sack_hole_zone); 239 #define V_sack_hole_zone VNET(sack_hole_zone) 240 241 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 242 243 static struct inpcb *tcp_notify(struct inpcb *, int); 244 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 245 static void tcp_mtudisc(struct inpcb *, int); 246 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 247 void *ip4hdr, const void *ip6hdr); 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 0, 262 0 263 }; 264 265 int t_functions_inited = 0; 266 struct tcp_funchead t_functions; 267 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 268 269 static void 270 init_tcp_functions(void) 271 { 272 if (t_functions_inited == 0) { 273 TAILQ_INIT(&t_functions); 274 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 275 t_functions_inited = 1; 276 } 277 } 278 279 static struct tcp_function_block * 280 find_tcp_functions_locked(struct tcp_function_set *fs) 281 { 282 struct tcp_function *f; 283 struct tcp_function_block *blk=NULL; 284 285 TAILQ_FOREACH(f, &t_functions, tf_next) { 286 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 287 blk = f->tf_fb; 288 break; 289 } 290 } 291 return(blk); 292 } 293 294 static struct tcp_function_block * 295 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 296 { 297 struct tcp_function_block *rblk=NULL; 298 struct tcp_function *f; 299 300 TAILQ_FOREACH(f, &t_functions, tf_next) { 301 if (f->tf_fb == blk) { 302 rblk = blk; 303 if (s) { 304 *s = f; 305 } 306 break; 307 } 308 } 309 return (rblk); 310 } 311 312 struct tcp_function_block * 313 find_and_ref_tcp_functions(struct tcp_function_set *fs) 314 { 315 struct tcp_function_block *blk; 316 317 rw_rlock(&tcp_function_lock); 318 blk = find_tcp_functions_locked(fs); 319 if (blk) 320 refcount_acquire(&blk->tfb_refcnt); 321 rw_runlock(&tcp_function_lock); 322 return(blk); 323 } 324 325 struct tcp_function_block * 326 find_and_ref_tcp_fb(struct tcp_function_block *blk) 327 { 328 struct tcp_function_block *rblk; 329 330 rw_rlock(&tcp_function_lock); 331 rblk = find_tcp_fb_locked(blk, NULL); 332 if (rblk) 333 refcount_acquire(&rblk->tfb_refcnt); 334 rw_runlock(&tcp_function_lock); 335 return(rblk); 336 } 337 338 339 static int 340 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 341 { 342 int error=ENOENT; 343 struct tcp_function_set fs; 344 struct tcp_function_block *blk; 345 346 memset(&fs, 0, sizeof(fs)); 347 rw_rlock(&tcp_function_lock); 348 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 349 if (blk) { 350 /* Found him */ 351 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 352 fs.pcbcnt = blk->tfb_refcnt; 353 } 354 rw_runlock(&tcp_function_lock); 355 error = sysctl_handle_string(oidp, fs.function_set_name, 356 sizeof(fs.function_set_name), req); 357 358 /* Check for error or no change */ 359 if (error != 0 || req->newptr == NULL) 360 return(error); 361 362 rw_wlock(&tcp_function_lock); 363 blk = find_tcp_functions_locked(&fs); 364 if ((blk == NULL) || 365 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 366 error = ENOENT; 367 goto done; 368 } 369 tcp_func_set_ptr = blk; 370 done: 371 rw_wunlock(&tcp_function_lock); 372 return (error); 373 } 374 375 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 376 CTLTYPE_STRING | CTLFLAG_RW, 377 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 378 "Set/get the default TCP functions"); 379 380 static int 381 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 382 { 383 int error, cnt, linesz; 384 struct tcp_function *f; 385 char *buffer, *cp; 386 size_t bufsz, outsz; 387 388 cnt = 0; 389 rw_rlock(&tcp_function_lock); 390 TAILQ_FOREACH(f, &t_functions, tf_next) { 391 cnt++; 392 } 393 rw_runlock(&tcp_function_lock); 394 395 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 396 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 397 398 error = 0; 399 cp = buffer; 400 401 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 402 cp += linesz; 403 bufsz -= linesz; 404 outsz = linesz; 405 406 rw_rlock(&tcp_function_lock); 407 TAILQ_FOREACH(f, &t_functions, tf_next) { 408 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 409 f->tf_fb->tfb_tcp_block_name, 410 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 411 f->tf_fb->tfb_refcnt); 412 if (linesz >= bufsz) { 413 error = EOVERFLOW; 414 break; 415 } 416 cp += linesz; 417 bufsz -= linesz; 418 outsz += linesz; 419 } 420 rw_runlock(&tcp_function_lock); 421 if (error == 0) 422 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 423 free(buffer, M_TEMP); 424 return (error); 425 } 426 427 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 428 CTLTYPE_STRING|CTLFLAG_RD, 429 NULL, 0, sysctl_net_inet_list_available, "A", 430 "list available TCP Function sets"); 431 432 /* 433 * Target size of TCP PCB hash tables. Must be a power of two. 434 * 435 * Note that this can be overridden by the kernel environment 436 * variable net.inet.tcp.tcbhashsize 437 */ 438 #ifndef TCBHASHSIZE 439 #define TCBHASHSIZE 0 440 #endif 441 442 /* 443 * XXX 444 * Callouts should be moved into struct tcp directly. They are currently 445 * separate because the tcpcb structure is exported to userland for sysctl 446 * parsing purposes, which do not know about callouts. 447 */ 448 struct tcpcb_mem { 449 struct tcpcb tcb; 450 struct tcp_timer tt; 451 struct cc_var ccv; 452 struct osd osd; 453 }; 454 455 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 456 #define V_tcpcb_zone VNET(tcpcb_zone) 457 458 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 459 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 460 461 static struct mtx isn_mtx; 462 463 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 464 #define ISN_LOCK() mtx_lock(&isn_mtx) 465 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 466 467 /* 468 * TCP initialization. 469 */ 470 static void 471 tcp_zone_change(void *tag) 472 { 473 474 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 475 uma_zone_set_max(V_tcpcb_zone, maxsockets); 476 tcp_tw_zone_change(); 477 } 478 479 static int 480 tcp_inpcb_init(void *mem, int size, int flags) 481 { 482 struct inpcb *inp = mem; 483 484 INP_LOCK_INIT(inp, "inp", "tcpinp"); 485 return (0); 486 } 487 488 /* 489 * Take a value and get the next power of 2 that doesn't overflow. 490 * Used to size the tcp_inpcb hash buckets. 491 */ 492 static int 493 maketcp_hashsize(int size) 494 { 495 int hashsize; 496 497 /* 498 * auto tune. 499 * get the next power of 2 higher than maxsockets. 500 */ 501 hashsize = 1 << fls(size); 502 /* catch overflow, and just go one power of 2 smaller */ 503 if (hashsize < size) { 504 hashsize = 1 << (fls(size) - 1); 505 } 506 return (hashsize); 507 } 508 509 int 510 register_tcp_functions(struct tcp_function_block *blk, int wait) 511 { 512 struct tcp_function_block *lblk; 513 struct tcp_function *n; 514 struct tcp_function_set fs; 515 516 if (t_functions_inited == 0) { 517 init_tcp_functions(); 518 } 519 if ((blk->tfb_tcp_output == NULL) || 520 (blk->tfb_tcp_do_segment == NULL) || 521 (blk->tfb_tcp_ctloutput == NULL) || 522 (strlen(blk->tfb_tcp_block_name) == 0)) { 523 /* 524 * These functions are required and you 525 * need a name. 526 */ 527 return (EINVAL); 528 } 529 if (blk->tfb_tcp_timer_stop_all || 530 blk->tfb_tcp_timer_activate || 531 blk->tfb_tcp_timer_active || 532 blk->tfb_tcp_timer_stop) { 533 /* 534 * If you define one timer function you 535 * must have them all. 536 */ 537 if ((blk->tfb_tcp_timer_stop_all == NULL) || 538 (blk->tfb_tcp_timer_activate == NULL) || 539 (blk->tfb_tcp_timer_active == NULL) || 540 (blk->tfb_tcp_timer_stop == NULL)) { 541 return (EINVAL); 542 } 543 } 544 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 545 if (n == NULL) { 546 return (ENOMEM); 547 } 548 n->tf_fb = blk; 549 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 550 rw_wlock(&tcp_function_lock); 551 lblk = find_tcp_functions_locked(&fs); 552 if (lblk) { 553 /* Duplicate name space not allowed */ 554 rw_wunlock(&tcp_function_lock); 555 free(n, M_TCPFUNCTIONS); 556 return (EALREADY); 557 } 558 refcount_init(&blk->tfb_refcnt, 0); 559 blk->tfb_flags = 0; 560 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 561 rw_wunlock(&tcp_function_lock); 562 return(0); 563 } 564 565 int 566 deregister_tcp_functions(struct tcp_function_block *blk) 567 { 568 struct tcp_function_block *lblk; 569 struct tcp_function *f; 570 int error=ENOENT; 571 572 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 573 /* You can't un-register the default */ 574 return (EPERM); 575 } 576 rw_wlock(&tcp_function_lock); 577 if (blk == tcp_func_set_ptr) { 578 /* You can't free the current default */ 579 rw_wunlock(&tcp_function_lock); 580 return (EBUSY); 581 } 582 if (blk->tfb_refcnt) { 583 /* Still tcb attached, mark it. */ 584 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 585 rw_wunlock(&tcp_function_lock); 586 return (EBUSY); 587 } 588 lblk = find_tcp_fb_locked(blk, &f); 589 if (lblk) { 590 /* Found */ 591 TAILQ_REMOVE(&t_functions, f, tf_next); 592 f->tf_fb = NULL; 593 free(f, M_TCPFUNCTIONS); 594 error = 0; 595 } 596 rw_wunlock(&tcp_function_lock); 597 return (error); 598 } 599 600 void 601 tcp_init(void) 602 { 603 const char *tcbhash_tuneable; 604 int hashsize; 605 606 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 607 608 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 609 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 610 printf("%s: WARNING: unable to register helper hook\n", __func__); 611 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 612 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 613 printf("%s: WARNING: unable to register helper hook\n", __func__); 614 hashsize = TCBHASHSIZE; 615 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 616 if (hashsize == 0) { 617 /* 618 * Auto tune the hash size based on maxsockets. 619 * A perfect hash would have a 1:1 mapping 620 * (hashsize = maxsockets) however it's been 621 * suggested that O(2) average is better. 622 */ 623 hashsize = maketcp_hashsize(maxsockets / 4); 624 /* 625 * Our historical default is 512, 626 * do not autotune lower than this. 627 */ 628 if (hashsize < 512) 629 hashsize = 512; 630 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 631 printf("%s: %s auto tuned to %d\n", __func__, 632 tcbhash_tuneable, hashsize); 633 } 634 /* 635 * We require a hashsize to be a power of two. 636 * Previously if it was not a power of two we would just reset it 637 * back to 512, which could be a nasty surprise if you did not notice 638 * the error message. 639 * Instead what we do is clip it to the closest power of two lower 640 * than the specified hash value. 641 */ 642 if (!powerof2(hashsize)) { 643 int oldhashsize = hashsize; 644 645 hashsize = maketcp_hashsize(hashsize); 646 /* prevent absurdly low value */ 647 if (hashsize < 16) 648 hashsize = 16; 649 printf("%s: WARNING: TCB hash size not a power of 2, " 650 "clipped from %d to %d.\n", __func__, oldhashsize, 651 hashsize); 652 } 653 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 654 "tcp_inpcb", tcp_inpcb_init, NULL, 0, IPI_HASHFIELDS_4TUPLE); 655 656 /* 657 * These have to be type stable for the benefit of the timers. 658 */ 659 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 660 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 661 uma_zone_set_max(V_tcpcb_zone, maxsockets); 662 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 663 664 tcp_tw_init(); 665 syncache_init(); 666 tcp_hc_init(); 667 668 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 669 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 670 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 671 672 /* Skip initialization of globals for non-default instances. */ 673 if (!IS_DEFAULT_VNET(curvnet)) 674 return; 675 676 tcp_reass_global_init(); 677 678 /* XXX virtualize those bellow? */ 679 tcp_delacktime = TCPTV_DELACK; 680 tcp_keepinit = TCPTV_KEEP_INIT; 681 tcp_keepidle = TCPTV_KEEP_IDLE; 682 tcp_keepintvl = TCPTV_KEEPINTVL; 683 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 684 tcp_msl = TCPTV_MSL; 685 tcp_rexmit_min = TCPTV_MIN; 686 if (tcp_rexmit_min < 1) 687 tcp_rexmit_min = 1; 688 tcp_persmin = TCPTV_PERSMIN; 689 tcp_persmax = TCPTV_PERSMAX; 690 tcp_rexmit_slop = TCPTV_CPU_VAR; 691 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 692 tcp_tcbhashsize = hashsize; 693 /* Setup the tcp function block list */ 694 init_tcp_functions(); 695 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 696 697 if (tcp_soreceive_stream) { 698 #ifdef INET 699 tcp_usrreqs.pru_soreceive = soreceive_stream; 700 #endif 701 #ifdef INET6 702 tcp6_usrreqs.pru_soreceive = soreceive_stream; 703 #endif /* INET6 */ 704 } 705 706 #ifdef INET6 707 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 708 #else /* INET6 */ 709 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 710 #endif /* INET6 */ 711 if (max_protohdr < TCP_MINPROTOHDR) 712 max_protohdr = TCP_MINPROTOHDR; 713 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 714 panic("tcp_init"); 715 #undef TCP_MINPROTOHDR 716 717 ISN_LOCK_INIT(); 718 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 719 SHUTDOWN_PRI_DEFAULT); 720 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 721 EVENTHANDLER_PRI_ANY); 722 #ifdef TCPPCAP 723 tcp_pcap_init(); 724 #endif 725 726 #ifdef TCP_RFC7413 727 tcp_fastopen_init(); 728 #endif 729 } 730 731 #ifdef VIMAGE 732 static void 733 tcp_destroy(void *unused __unused) 734 { 735 int error, n; 736 737 /* 738 * All our processes are gone, all our sockets should be cleaned 739 * up, which means, we should be past the tcp_discardcb() calls. 740 * Sleep to let all tcpcb timers really disappear and cleanup. 741 */ 742 for (;;) { 743 INP_LIST_RLOCK(&V_tcbinfo); 744 n = V_tcbinfo.ipi_count; 745 INP_LIST_RUNLOCK(&V_tcbinfo); 746 if (n == 0) 747 break; 748 pause("tcpdes", hz / 10); 749 } 750 tcp_hc_destroy(); 751 syncache_destroy(); 752 tcp_tw_destroy(); 753 in_pcbinfo_destroy(&V_tcbinfo); 754 /* tcp_discardcb() clears the sack_holes up. */ 755 uma_zdestroy(V_sack_hole_zone); 756 uma_zdestroy(V_tcpcb_zone); 757 758 #ifdef TCP_RFC7413 759 /* 760 * Cannot free the zone until all tcpcbs are released as we attach 761 * the allocations to them. 762 */ 763 tcp_fastopen_destroy(); 764 #endif 765 766 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 767 if (error != 0) { 768 printf("%s: WARNING: unable to deregister helper hook " 769 "type=%d, id=%d: error %d returned\n", __func__, 770 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 771 } 772 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 773 if (error != 0) { 774 printf("%s: WARNING: unable to deregister helper hook " 775 "type=%d, id=%d: error %d returned\n", __func__, 776 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 777 } 778 } 779 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 780 #endif 781 782 void 783 tcp_fini(void *xtp) 784 { 785 786 } 787 788 /* 789 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 790 * tcp_template used to store this data in mbufs, but we now recopy it out 791 * of the tcpcb each time to conserve mbufs. 792 */ 793 void 794 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 795 { 796 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 797 798 INP_WLOCK_ASSERT(inp); 799 800 #ifdef INET6 801 if ((inp->inp_vflag & INP_IPV6) != 0) { 802 struct ip6_hdr *ip6; 803 804 ip6 = (struct ip6_hdr *)ip_ptr; 805 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 806 (inp->inp_flow & IPV6_FLOWINFO_MASK); 807 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 808 (IPV6_VERSION & IPV6_VERSION_MASK); 809 ip6->ip6_nxt = IPPROTO_TCP; 810 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 811 ip6->ip6_src = inp->in6p_laddr; 812 ip6->ip6_dst = inp->in6p_faddr; 813 } 814 #endif /* INET6 */ 815 #if defined(INET6) && defined(INET) 816 else 817 #endif 818 #ifdef INET 819 { 820 struct ip *ip; 821 822 ip = (struct ip *)ip_ptr; 823 ip->ip_v = IPVERSION; 824 ip->ip_hl = 5; 825 ip->ip_tos = inp->inp_ip_tos; 826 ip->ip_len = 0; 827 ip->ip_id = 0; 828 ip->ip_off = 0; 829 ip->ip_ttl = inp->inp_ip_ttl; 830 ip->ip_sum = 0; 831 ip->ip_p = IPPROTO_TCP; 832 ip->ip_src = inp->inp_laddr; 833 ip->ip_dst = inp->inp_faddr; 834 } 835 #endif /* INET */ 836 th->th_sport = inp->inp_lport; 837 th->th_dport = inp->inp_fport; 838 th->th_seq = 0; 839 th->th_ack = 0; 840 th->th_x2 = 0; 841 th->th_off = 5; 842 th->th_flags = 0; 843 th->th_win = 0; 844 th->th_urp = 0; 845 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 846 } 847 848 /* 849 * Create template to be used to send tcp packets on a connection. 850 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 851 * use for this function is in keepalives, which use tcp_respond. 852 */ 853 struct tcptemp * 854 tcpip_maketemplate(struct inpcb *inp) 855 { 856 struct tcptemp *t; 857 858 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 859 if (t == NULL) 860 return (NULL); 861 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 862 return (t); 863 } 864 865 /* 866 * Send a single message to the TCP at address specified by 867 * the given TCP/IP header. If m == NULL, then we make a copy 868 * of the tcpiphdr at th and send directly to the addressed host. 869 * This is used to force keep alive messages out using the TCP 870 * template for a connection. If flags are given then we send 871 * a message back to the TCP which originated the segment th, 872 * and discard the mbuf containing it and any other attached mbufs. 873 * 874 * In any case the ack and sequence number of the transmitted 875 * segment are as specified by the parameters. 876 * 877 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 878 */ 879 void 880 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 881 tcp_seq ack, tcp_seq seq, int flags) 882 { 883 struct tcpopt to; 884 struct inpcb *inp; 885 struct ip *ip; 886 struct mbuf *optm; 887 struct tcphdr *nth; 888 u_char *optp; 889 #ifdef INET6 890 struct ip6_hdr *ip6; 891 int isipv6; 892 #endif /* INET6 */ 893 int optlen, tlen, win; 894 bool incl_opts; 895 896 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 897 898 #ifdef INET6 899 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 900 ip6 = ipgen; 901 #endif /* INET6 */ 902 ip = ipgen; 903 904 if (tp != NULL) { 905 inp = tp->t_inpcb; 906 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 907 INP_WLOCK_ASSERT(inp); 908 } else 909 inp = NULL; 910 911 incl_opts = false; 912 win = 0; 913 if (tp != NULL) { 914 if (!(flags & TH_RST)) { 915 win = sbspace(&inp->inp_socket->so_rcv); 916 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 917 win = (long)TCP_MAXWIN << tp->rcv_scale; 918 } 919 if ((tp->t_flags & TF_NOOPT) == 0) 920 incl_opts = true; 921 } 922 if (m == NULL) { 923 m = m_gethdr(M_NOWAIT, MT_DATA); 924 if (m == NULL) 925 return; 926 m->m_data += max_linkhdr; 927 #ifdef INET6 928 if (isipv6) { 929 bcopy((caddr_t)ip6, mtod(m, caddr_t), 930 sizeof(struct ip6_hdr)); 931 ip6 = mtod(m, struct ip6_hdr *); 932 nth = (struct tcphdr *)(ip6 + 1); 933 } else 934 #endif /* INET6 */ 935 { 936 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 937 ip = mtod(m, struct ip *); 938 nth = (struct tcphdr *)(ip + 1); 939 } 940 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 941 flags = TH_ACK; 942 } else if (!M_WRITABLE(m)) { 943 struct mbuf *n; 944 945 /* Can't reuse 'm', allocate a new mbuf. */ 946 n = m_gethdr(M_NOWAIT, MT_DATA); 947 if (n == NULL) { 948 m_freem(m); 949 return; 950 } 951 952 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 953 m_freem(m); 954 m_freem(n); 955 return; 956 } 957 958 n->m_data += max_linkhdr; 959 /* m_len is set later */ 960 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 961 #ifdef INET6 962 if (isipv6) { 963 bcopy((caddr_t)ip6, mtod(n, caddr_t), 964 sizeof(struct ip6_hdr)); 965 ip6 = mtod(n, struct ip6_hdr *); 966 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 967 nth = (struct tcphdr *)(ip6 + 1); 968 } else 969 #endif /* INET6 */ 970 { 971 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 972 ip = mtod(n, struct ip *); 973 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 974 nth = (struct tcphdr *)(ip + 1); 975 } 976 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 977 xchg(nth->th_dport, nth->th_sport, uint16_t); 978 th = nth; 979 m_freem(m); 980 m = n; 981 } else { 982 /* 983 * reuse the mbuf. 984 * XXX MRT We inherit the FIB, which is lucky. 985 */ 986 m_freem(m->m_next); 987 m->m_next = NULL; 988 m->m_data = (caddr_t)ipgen; 989 /* m_len is set later */ 990 #ifdef INET6 991 if (isipv6) { 992 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 993 nth = (struct tcphdr *)(ip6 + 1); 994 } else 995 #endif /* INET6 */ 996 { 997 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 998 nth = (struct tcphdr *)(ip + 1); 999 } 1000 if (th != nth) { 1001 /* 1002 * this is usually a case when an extension header 1003 * exists between the IPv6 header and the 1004 * TCP header. 1005 */ 1006 nth->th_sport = th->th_sport; 1007 nth->th_dport = th->th_dport; 1008 } 1009 xchg(nth->th_dport, nth->th_sport, uint16_t); 1010 #undef xchg 1011 } 1012 tlen = 0; 1013 #ifdef INET6 1014 if (isipv6) 1015 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1016 #endif 1017 #if defined(INET) && defined(INET6) 1018 else 1019 #endif 1020 #ifdef INET 1021 tlen = sizeof (struct tcpiphdr); 1022 #endif 1023 #ifdef INVARIANTS 1024 m->m_len = 0; 1025 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1026 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1027 m, tlen, (long)M_TRAILINGSPACE(m))); 1028 #endif 1029 m->m_len = tlen; 1030 to.to_flags = 0; 1031 if (incl_opts) { 1032 /* Make sure we have room. */ 1033 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1034 m->m_next = m_get(M_NOWAIT, MT_DATA); 1035 if (m->m_next) { 1036 optp = mtod(m->m_next, u_char *); 1037 optm = m->m_next; 1038 } else 1039 incl_opts = false; 1040 } else { 1041 optp = (u_char *) (nth + 1); 1042 optm = m; 1043 } 1044 } 1045 if (incl_opts) { 1046 /* Timestamps. */ 1047 if (tp->t_flags & TF_RCVD_TSTMP) { 1048 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1049 to.to_tsecr = tp->ts_recent; 1050 to.to_flags |= TOF_TS; 1051 } 1052 #ifdef TCP_SIGNATURE 1053 /* TCP-MD5 (RFC2385). */ 1054 if (tp->t_flags & TF_SIGNATURE) 1055 to.to_flags |= TOF_SIGNATURE; 1056 #endif 1057 1058 /* Add the options. */ 1059 tlen += optlen = tcp_addoptions(&to, optp); 1060 1061 /* Update m_len in the correct mbuf. */ 1062 optm->m_len += optlen; 1063 } else 1064 optlen = 0; 1065 #ifdef INET6 1066 if (isipv6) { 1067 ip6->ip6_flow = 0; 1068 ip6->ip6_vfc = IPV6_VERSION; 1069 ip6->ip6_nxt = IPPROTO_TCP; 1070 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1071 } 1072 #endif 1073 #if defined(INET) && defined(INET6) 1074 else 1075 #endif 1076 #ifdef INET 1077 { 1078 ip->ip_len = htons(tlen); 1079 ip->ip_ttl = V_ip_defttl; 1080 if (V_path_mtu_discovery) 1081 ip->ip_off |= htons(IP_DF); 1082 } 1083 #endif 1084 m->m_pkthdr.len = tlen; 1085 m->m_pkthdr.rcvif = NULL; 1086 #ifdef MAC 1087 if (inp != NULL) { 1088 /* 1089 * Packet is associated with a socket, so allow the 1090 * label of the response to reflect the socket label. 1091 */ 1092 INP_WLOCK_ASSERT(inp); 1093 mac_inpcb_create_mbuf(inp, m); 1094 } else { 1095 /* 1096 * Packet is not associated with a socket, so possibly 1097 * update the label in place. 1098 */ 1099 mac_netinet_tcp_reply(m); 1100 } 1101 #endif 1102 nth->th_seq = htonl(seq); 1103 nth->th_ack = htonl(ack); 1104 nth->th_x2 = 0; 1105 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1106 nth->th_flags = flags; 1107 if (tp != NULL) 1108 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1109 else 1110 nth->th_win = htons((u_short)win); 1111 nth->th_urp = 0; 1112 1113 #ifdef TCP_SIGNATURE 1114 if (to.to_flags & TOF_SIGNATURE) { 1115 tcp_signature_compute(m, 0, 0, optlen, to.to_signature, 1116 IPSEC_DIR_OUTBOUND); 1117 } 1118 #endif 1119 1120 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1121 #ifdef INET6 1122 if (isipv6) { 1123 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1124 nth->th_sum = in6_cksum_pseudo(ip6, 1125 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1126 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1127 NULL, NULL); 1128 } 1129 #endif /* INET6 */ 1130 #if defined(INET6) && defined(INET) 1131 else 1132 #endif 1133 #ifdef INET 1134 { 1135 m->m_pkthdr.csum_flags = CSUM_TCP; 1136 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1137 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1138 } 1139 #endif /* INET */ 1140 #ifdef TCPDEBUG 1141 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1142 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1143 #endif 1144 TCP_PROBE3(debug__output, tp, th, mtod(m, const char *)); 1145 if (flags & TH_RST) 1146 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1147 tp, nth); 1148 1149 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1150 #ifdef INET6 1151 if (isipv6) 1152 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1153 #endif /* INET6 */ 1154 #if defined(INET) && defined(INET6) 1155 else 1156 #endif 1157 #ifdef INET 1158 (void) ip_output(m, NULL, NULL, 0, NULL, inp); 1159 #endif 1160 } 1161 1162 /* 1163 * Create a new TCP control block, making an 1164 * empty reassembly queue and hooking it to the argument 1165 * protocol control block. The `inp' parameter must have 1166 * come from the zone allocator set up in tcp_init(). 1167 */ 1168 struct tcpcb * 1169 tcp_newtcpcb(struct inpcb *inp) 1170 { 1171 struct tcpcb_mem *tm; 1172 struct tcpcb *tp; 1173 #ifdef INET6 1174 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1175 #endif /* INET6 */ 1176 1177 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1178 if (tm == NULL) 1179 return (NULL); 1180 tp = &tm->tcb; 1181 1182 /* Initialise cc_var struct for this tcpcb. */ 1183 tp->ccv = &tm->ccv; 1184 tp->ccv->type = IPPROTO_TCP; 1185 tp->ccv->ccvc.tcp = tp; 1186 rw_rlock(&tcp_function_lock); 1187 tp->t_fb = tcp_func_set_ptr; 1188 refcount_acquire(&tp->t_fb->tfb_refcnt); 1189 rw_runlock(&tcp_function_lock); 1190 /* 1191 * Use the current system default CC algorithm. 1192 */ 1193 CC_LIST_RLOCK(); 1194 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1195 CC_ALGO(tp) = CC_DEFAULT(); 1196 CC_LIST_RUNLOCK(); 1197 1198 if (CC_ALGO(tp)->cb_init != NULL) 1199 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1200 if (tp->t_fb->tfb_tcp_fb_fini) 1201 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1202 refcount_release(&tp->t_fb->tfb_refcnt); 1203 uma_zfree(V_tcpcb_zone, tm); 1204 return (NULL); 1205 } 1206 1207 tp->osd = &tm->osd; 1208 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1209 if (tp->t_fb->tfb_tcp_fb_fini) 1210 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1211 refcount_release(&tp->t_fb->tfb_refcnt); 1212 uma_zfree(V_tcpcb_zone, tm); 1213 return (NULL); 1214 } 1215 1216 #ifdef VIMAGE 1217 tp->t_vnet = inp->inp_vnet; 1218 #endif 1219 tp->t_timers = &tm->tt; 1220 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1221 tp->t_maxseg = 1222 #ifdef INET6 1223 isipv6 ? V_tcp_v6mssdflt : 1224 #endif /* INET6 */ 1225 V_tcp_mssdflt; 1226 1227 /* Set up our timeouts. */ 1228 callout_init(&tp->t_timers->tt_rexmt, 1); 1229 callout_init(&tp->t_timers->tt_persist, 1); 1230 callout_init(&tp->t_timers->tt_keep, 1); 1231 callout_init(&tp->t_timers->tt_2msl, 1); 1232 callout_init(&tp->t_timers->tt_delack, 1); 1233 1234 if (V_tcp_do_rfc1323) 1235 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1236 if (V_tcp_do_sack) 1237 tp->t_flags |= TF_SACK_PERMIT; 1238 TAILQ_INIT(&tp->snd_holes); 1239 /* 1240 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1241 * is called. 1242 */ 1243 in_pcbref(inp); /* Reference for tcpcb */ 1244 tp->t_inpcb = inp; 1245 1246 /* 1247 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1248 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1249 * reasonable initial retransmit time. 1250 */ 1251 tp->t_srtt = TCPTV_SRTTBASE; 1252 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1253 tp->t_rttmin = tcp_rexmit_min; 1254 tp->t_rxtcur = TCPTV_RTOBASE; 1255 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1256 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1257 tp->t_rcvtime = ticks; 1258 /* 1259 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1260 * because the socket may be bound to an IPv6 wildcard address, 1261 * which may match an IPv4-mapped IPv6 address. 1262 */ 1263 inp->inp_ip_ttl = V_ip_defttl; 1264 inp->inp_ppcb = tp; 1265 #ifdef TCPPCAP 1266 /* 1267 * Init the TCP PCAP queues. 1268 */ 1269 tcp_pcap_tcpcb_init(tp); 1270 #endif 1271 if (tp->t_fb->tfb_tcp_fb_init) { 1272 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1273 } 1274 return (tp); /* XXX */ 1275 } 1276 1277 /* 1278 * Switch the congestion control algorithm back to NewReno for any active 1279 * control blocks using an algorithm which is about to go away. 1280 * This ensures the CC framework can allow the unload to proceed without leaving 1281 * any dangling pointers which would trigger a panic. 1282 * Returning non-zero would inform the CC framework that something went wrong 1283 * and it would be unsafe to allow the unload to proceed. However, there is no 1284 * way for this to occur with this implementation so we always return zero. 1285 */ 1286 int 1287 tcp_ccalgounload(struct cc_algo *unload_algo) 1288 { 1289 struct cc_algo *tmpalgo; 1290 struct inpcb *inp; 1291 struct tcpcb *tp; 1292 VNET_ITERATOR_DECL(vnet_iter); 1293 1294 /* 1295 * Check all active control blocks across all network stacks and change 1296 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1297 * requires cleanup code to be run, call it. 1298 */ 1299 VNET_LIST_RLOCK(); 1300 VNET_FOREACH(vnet_iter) { 1301 CURVNET_SET(vnet_iter); 1302 INP_INFO_WLOCK(&V_tcbinfo); 1303 /* 1304 * New connections already part way through being initialised 1305 * with the CC algo we're removing will not race with this code 1306 * because the INP_INFO_WLOCK is held during initialisation. We 1307 * therefore don't enter the loop below until the connection 1308 * list has stabilised. 1309 */ 1310 LIST_FOREACH(inp, &V_tcb, inp_list) { 1311 INP_WLOCK(inp); 1312 /* Important to skip tcptw structs. */ 1313 if (!(inp->inp_flags & INP_TIMEWAIT) && 1314 (tp = intotcpcb(inp)) != NULL) { 1315 /* 1316 * By holding INP_WLOCK here, we are assured 1317 * that the connection is not currently 1318 * executing inside the CC module's functions 1319 * i.e. it is safe to make the switch back to 1320 * NewReno. 1321 */ 1322 if (CC_ALGO(tp) == unload_algo) { 1323 tmpalgo = CC_ALGO(tp); 1324 /* NewReno does not require any init. */ 1325 CC_ALGO(tp) = &newreno_cc_algo; 1326 if (tmpalgo->cb_destroy != NULL) 1327 tmpalgo->cb_destroy(tp->ccv); 1328 } 1329 } 1330 INP_WUNLOCK(inp); 1331 } 1332 INP_INFO_WUNLOCK(&V_tcbinfo); 1333 CURVNET_RESTORE(); 1334 } 1335 VNET_LIST_RUNLOCK(); 1336 1337 return (0); 1338 } 1339 1340 /* 1341 * Drop a TCP connection, reporting 1342 * the specified error. If connection is synchronized, 1343 * then send a RST to peer. 1344 */ 1345 struct tcpcb * 1346 tcp_drop(struct tcpcb *tp, int errno) 1347 { 1348 struct socket *so = tp->t_inpcb->inp_socket; 1349 1350 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1351 INP_WLOCK_ASSERT(tp->t_inpcb); 1352 1353 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1354 tcp_state_change(tp, TCPS_CLOSED); 1355 (void) tp->t_fb->tfb_tcp_output(tp); 1356 TCPSTAT_INC(tcps_drops); 1357 } else 1358 TCPSTAT_INC(tcps_conndrops); 1359 if (errno == ETIMEDOUT && tp->t_softerror) 1360 errno = tp->t_softerror; 1361 so->so_error = errno; 1362 return (tcp_close(tp)); 1363 } 1364 1365 void 1366 tcp_discardcb(struct tcpcb *tp) 1367 { 1368 struct inpcb *inp = tp->t_inpcb; 1369 struct socket *so = inp->inp_socket; 1370 #ifdef INET6 1371 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1372 #endif /* INET6 */ 1373 int released; 1374 1375 INP_WLOCK_ASSERT(inp); 1376 1377 /* 1378 * Make sure that all of our timers are stopped before we delete the 1379 * PCB. 1380 * 1381 * If stopping a timer fails, we schedule a discard function in same 1382 * callout, and the last discard function called will take care of 1383 * deleting the tcpcb. 1384 */ 1385 tp->t_timers->tt_draincnt = 0; 1386 tcp_timer_stop(tp, TT_REXMT); 1387 tcp_timer_stop(tp, TT_PERSIST); 1388 tcp_timer_stop(tp, TT_KEEP); 1389 tcp_timer_stop(tp, TT_2MSL); 1390 tcp_timer_stop(tp, TT_DELACK); 1391 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1392 /* 1393 * Call the stop-all function of the methods, 1394 * this function should call the tcp_timer_stop() 1395 * method with each of the function specific timeouts. 1396 * That stop will be called via the tfb_tcp_timer_stop() 1397 * which should use the async drain function of the 1398 * callout system (see tcp_var.h). 1399 */ 1400 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1401 } 1402 1403 /* 1404 * If we got enough samples through the srtt filter, 1405 * save the rtt and rttvar in the routing entry. 1406 * 'Enough' is arbitrarily defined as 4 rtt samples. 1407 * 4 samples is enough for the srtt filter to converge 1408 * to within enough % of the correct value; fewer samples 1409 * and we could save a bogus rtt. The danger is not high 1410 * as tcp quickly recovers from everything. 1411 * XXX: Works very well but needs some more statistics! 1412 */ 1413 if (tp->t_rttupdated >= 4) { 1414 struct hc_metrics_lite metrics; 1415 u_long ssthresh; 1416 1417 bzero(&metrics, sizeof(metrics)); 1418 /* 1419 * Update the ssthresh always when the conditions below 1420 * are satisfied. This gives us better new start value 1421 * for the congestion avoidance for new connections. 1422 * ssthresh is only set if packet loss occurred on a session. 1423 * 1424 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1425 * being torn down. Ideally this code would not use 'so'. 1426 */ 1427 ssthresh = tp->snd_ssthresh; 1428 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1429 /* 1430 * convert the limit from user data bytes to 1431 * packets then to packet data bytes. 1432 */ 1433 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1434 if (ssthresh < 2) 1435 ssthresh = 2; 1436 ssthresh *= (u_long)(tp->t_maxseg + 1437 #ifdef INET6 1438 (isipv6 ? sizeof (struct ip6_hdr) + 1439 sizeof (struct tcphdr) : 1440 #endif 1441 sizeof (struct tcpiphdr) 1442 #ifdef INET6 1443 ) 1444 #endif 1445 ); 1446 } else 1447 ssthresh = 0; 1448 metrics.rmx_ssthresh = ssthresh; 1449 1450 metrics.rmx_rtt = tp->t_srtt; 1451 metrics.rmx_rttvar = tp->t_rttvar; 1452 metrics.rmx_cwnd = tp->snd_cwnd; 1453 metrics.rmx_sendpipe = 0; 1454 metrics.rmx_recvpipe = 0; 1455 1456 tcp_hc_update(&inp->inp_inc, &metrics); 1457 } 1458 1459 /* free the reassembly queue, if any */ 1460 tcp_reass_flush(tp); 1461 1462 #ifdef TCP_OFFLOAD 1463 /* Disconnect offload device, if any. */ 1464 if (tp->t_flags & TF_TOE) 1465 tcp_offload_detach(tp); 1466 #endif 1467 1468 tcp_free_sackholes(tp); 1469 1470 #ifdef TCPPCAP 1471 /* Free the TCP PCAP queues. */ 1472 tcp_pcap_drain(&(tp->t_inpkts)); 1473 tcp_pcap_drain(&(tp->t_outpkts)); 1474 #endif 1475 1476 /* Allow the CC algorithm to clean up after itself. */ 1477 if (CC_ALGO(tp)->cb_destroy != NULL) 1478 CC_ALGO(tp)->cb_destroy(tp->ccv); 1479 1480 khelp_destroy_osd(tp->osd); 1481 1482 CC_ALGO(tp) = NULL; 1483 inp->inp_ppcb = NULL; 1484 if (tp->t_timers->tt_draincnt == 0) { 1485 /* We own the last reference on tcpcb, let's free it. */ 1486 if (tp->t_fb->tfb_tcp_fb_fini) 1487 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1488 refcount_release(&tp->t_fb->tfb_refcnt); 1489 tp->t_inpcb = NULL; 1490 uma_zfree(V_tcpcb_zone, tp); 1491 released = in_pcbrele_wlocked(inp); 1492 KASSERT(!released, ("%s: inp %p should not have been released " 1493 "here", __func__, inp)); 1494 } 1495 } 1496 1497 void 1498 tcp_timer_discard(void *ptp) 1499 { 1500 struct inpcb *inp; 1501 struct tcpcb *tp; 1502 1503 tp = (struct tcpcb *)ptp; 1504 CURVNET_SET(tp->t_vnet); 1505 INP_INFO_RLOCK(&V_tcbinfo); 1506 inp = tp->t_inpcb; 1507 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1508 __func__, tp)); 1509 INP_WLOCK(inp); 1510 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1511 ("%s: tcpcb has to be stopped here", __func__)); 1512 tp->t_timers->tt_draincnt--; 1513 if (tp->t_timers->tt_draincnt == 0) { 1514 /* We own the last reference on this tcpcb, let's free it. */ 1515 if (tp->t_fb->tfb_tcp_fb_fini) 1516 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1517 refcount_release(&tp->t_fb->tfb_refcnt); 1518 tp->t_inpcb = NULL; 1519 uma_zfree(V_tcpcb_zone, tp); 1520 if (in_pcbrele_wlocked(inp)) { 1521 INP_INFO_RUNLOCK(&V_tcbinfo); 1522 CURVNET_RESTORE(); 1523 return; 1524 } 1525 } 1526 INP_WUNLOCK(inp); 1527 INP_INFO_RUNLOCK(&V_tcbinfo); 1528 CURVNET_RESTORE(); 1529 } 1530 1531 /* 1532 * Attempt to close a TCP control block, marking it as dropped, and freeing 1533 * the socket if we hold the only reference. 1534 */ 1535 struct tcpcb * 1536 tcp_close(struct tcpcb *tp) 1537 { 1538 struct inpcb *inp = tp->t_inpcb; 1539 struct socket *so; 1540 1541 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1542 INP_WLOCK_ASSERT(inp); 1543 1544 #ifdef TCP_OFFLOAD 1545 if (tp->t_state == TCPS_LISTEN) 1546 tcp_offload_listen_stop(tp); 1547 #endif 1548 #ifdef TCP_RFC7413 1549 /* 1550 * This releases the TFO pending counter resource for TFO listen 1551 * sockets as well as passively-created TFO sockets that transition 1552 * from SYN_RECEIVED to CLOSED. 1553 */ 1554 if (tp->t_tfo_pending) { 1555 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1556 tp->t_tfo_pending = NULL; 1557 } 1558 #endif 1559 in_pcbdrop(inp); 1560 TCPSTAT_INC(tcps_closed); 1561 TCPSTATES_DEC(tp->t_state); 1562 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1563 so = inp->inp_socket; 1564 soisdisconnected(so); 1565 if (inp->inp_flags & INP_SOCKREF) { 1566 KASSERT(so->so_state & SS_PROTOREF, 1567 ("tcp_close: !SS_PROTOREF")); 1568 inp->inp_flags &= ~INP_SOCKREF; 1569 INP_WUNLOCK(inp); 1570 ACCEPT_LOCK(); 1571 SOCK_LOCK(so); 1572 so->so_state &= ~SS_PROTOREF; 1573 sofree(so); 1574 return (NULL); 1575 } 1576 return (tp); 1577 } 1578 1579 void 1580 tcp_drain(void) 1581 { 1582 VNET_ITERATOR_DECL(vnet_iter); 1583 1584 if (!do_tcpdrain) 1585 return; 1586 1587 VNET_LIST_RLOCK_NOSLEEP(); 1588 VNET_FOREACH(vnet_iter) { 1589 CURVNET_SET(vnet_iter); 1590 struct inpcb *inpb; 1591 struct tcpcb *tcpb; 1592 1593 /* 1594 * Walk the tcpbs, if existing, and flush the reassembly queue, 1595 * if there is one... 1596 * XXX: The "Net/3" implementation doesn't imply that the TCP 1597 * reassembly queue should be flushed, but in a situation 1598 * where we're really low on mbufs, this is potentially 1599 * useful. 1600 */ 1601 INP_INFO_WLOCK(&V_tcbinfo); 1602 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1603 if (inpb->inp_flags & INP_TIMEWAIT) 1604 continue; 1605 INP_WLOCK(inpb); 1606 if ((tcpb = intotcpcb(inpb)) != NULL) { 1607 tcp_reass_flush(tcpb); 1608 tcp_clean_sackreport(tcpb); 1609 #ifdef TCPPCAP 1610 if (tcp_pcap_aggressive_free) { 1611 /* Free the TCP PCAP queues. */ 1612 tcp_pcap_drain(&(tcpb->t_inpkts)); 1613 tcp_pcap_drain(&(tcpb->t_outpkts)); 1614 } 1615 #endif 1616 } 1617 INP_WUNLOCK(inpb); 1618 } 1619 INP_INFO_WUNLOCK(&V_tcbinfo); 1620 CURVNET_RESTORE(); 1621 } 1622 VNET_LIST_RUNLOCK_NOSLEEP(); 1623 } 1624 1625 /* 1626 * Notify a tcp user of an asynchronous error; 1627 * store error as soft error, but wake up user 1628 * (for now, won't do anything until can select for soft error). 1629 * 1630 * Do not wake up user since there currently is no mechanism for 1631 * reporting soft errors (yet - a kqueue filter may be added). 1632 */ 1633 static struct inpcb * 1634 tcp_notify(struct inpcb *inp, int error) 1635 { 1636 struct tcpcb *tp; 1637 1638 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1639 INP_WLOCK_ASSERT(inp); 1640 1641 if ((inp->inp_flags & INP_TIMEWAIT) || 1642 (inp->inp_flags & INP_DROPPED)) 1643 return (inp); 1644 1645 tp = intotcpcb(inp); 1646 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1647 1648 /* 1649 * Ignore some errors if we are hooked up. 1650 * If connection hasn't completed, has retransmitted several times, 1651 * and receives a second error, give up now. This is better 1652 * than waiting a long time to establish a connection that 1653 * can never complete. 1654 */ 1655 if (tp->t_state == TCPS_ESTABLISHED && 1656 (error == EHOSTUNREACH || error == ENETUNREACH || 1657 error == EHOSTDOWN)) { 1658 if (inp->inp_route.ro_rt) { 1659 RTFREE(inp->inp_route.ro_rt); 1660 inp->inp_route.ro_rt = (struct rtentry *)NULL; 1661 } 1662 return (inp); 1663 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1664 tp->t_softerror) { 1665 tp = tcp_drop(tp, error); 1666 if (tp != NULL) 1667 return (inp); 1668 else 1669 return (NULL); 1670 } else { 1671 tp->t_softerror = error; 1672 return (inp); 1673 } 1674 #if 0 1675 wakeup( &so->so_timeo); 1676 sorwakeup(so); 1677 sowwakeup(so); 1678 #endif 1679 } 1680 1681 static int 1682 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1683 { 1684 int error, i, m, n, pcb_count; 1685 struct inpcb *inp, **inp_list; 1686 inp_gen_t gencnt; 1687 struct xinpgen xig; 1688 1689 /* 1690 * The process of preparing the TCB list is too time-consuming and 1691 * resource-intensive to repeat twice on every request. 1692 */ 1693 if (req->oldptr == NULL) { 1694 n = V_tcbinfo.ipi_count + 1695 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1696 n += imax(n / 8, 10); 1697 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1698 return (0); 1699 } 1700 1701 if (req->newptr != NULL) 1702 return (EPERM); 1703 1704 /* 1705 * OK, now we're committed to doing something. 1706 */ 1707 INP_LIST_RLOCK(&V_tcbinfo); 1708 gencnt = V_tcbinfo.ipi_gencnt; 1709 n = V_tcbinfo.ipi_count; 1710 INP_LIST_RUNLOCK(&V_tcbinfo); 1711 1712 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1713 1714 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1715 + (n + m) * sizeof(struct xtcpcb)); 1716 if (error != 0) 1717 return (error); 1718 1719 xig.xig_len = sizeof xig; 1720 xig.xig_count = n + m; 1721 xig.xig_gen = gencnt; 1722 xig.xig_sogen = so_gencnt; 1723 error = SYSCTL_OUT(req, &xig, sizeof xig); 1724 if (error) 1725 return (error); 1726 1727 error = syncache_pcblist(req, m, &pcb_count); 1728 if (error) 1729 return (error); 1730 1731 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1732 1733 INP_INFO_WLOCK(&V_tcbinfo); 1734 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1735 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1736 INP_WLOCK(inp); 1737 if (inp->inp_gencnt <= gencnt) { 1738 /* 1739 * XXX: This use of cr_cansee(), introduced with 1740 * TCP state changes, is not quite right, but for 1741 * now, better than nothing. 1742 */ 1743 if (inp->inp_flags & INP_TIMEWAIT) { 1744 if (intotw(inp) != NULL) 1745 error = cr_cansee(req->td->td_ucred, 1746 intotw(inp)->tw_cred); 1747 else 1748 error = EINVAL; /* Skip this inp. */ 1749 } else 1750 error = cr_canseeinpcb(req->td->td_ucred, inp); 1751 if (error == 0) { 1752 in_pcbref(inp); 1753 inp_list[i++] = inp; 1754 } 1755 } 1756 INP_WUNLOCK(inp); 1757 } 1758 INP_INFO_WUNLOCK(&V_tcbinfo); 1759 n = i; 1760 1761 error = 0; 1762 for (i = 0; i < n; i++) { 1763 inp = inp_list[i]; 1764 INP_RLOCK(inp); 1765 if (inp->inp_gencnt <= gencnt) { 1766 struct xtcpcb xt; 1767 void *inp_ppcb; 1768 1769 bzero(&xt, sizeof(xt)); 1770 xt.xt_len = sizeof xt; 1771 /* XXX should avoid extra copy */ 1772 bcopy(inp, &xt.xt_inp, sizeof *inp); 1773 inp_ppcb = inp->inp_ppcb; 1774 if (inp_ppcb == NULL) 1775 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1776 else if (inp->inp_flags & INP_TIMEWAIT) { 1777 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1778 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1779 } else { 1780 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1781 if (xt.xt_tp.t_timers) 1782 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1783 } 1784 if (inp->inp_socket != NULL) 1785 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1786 else { 1787 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1788 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1789 } 1790 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1791 INP_RUNLOCK(inp); 1792 error = SYSCTL_OUT(req, &xt, sizeof xt); 1793 } else 1794 INP_RUNLOCK(inp); 1795 } 1796 INP_INFO_RLOCK(&V_tcbinfo); 1797 for (i = 0; i < n; i++) { 1798 inp = inp_list[i]; 1799 INP_RLOCK(inp); 1800 if (!in_pcbrele_rlocked(inp)) 1801 INP_RUNLOCK(inp); 1802 } 1803 INP_INFO_RUNLOCK(&V_tcbinfo); 1804 1805 if (!error) { 1806 /* 1807 * Give the user an updated idea of our state. 1808 * If the generation differs from what we told 1809 * her before, she knows that something happened 1810 * while we were processing this request, and it 1811 * might be necessary to retry. 1812 */ 1813 INP_LIST_RLOCK(&V_tcbinfo); 1814 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1815 xig.xig_sogen = so_gencnt; 1816 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1817 INP_LIST_RUNLOCK(&V_tcbinfo); 1818 error = SYSCTL_OUT(req, &xig, sizeof xig); 1819 } 1820 free(inp_list, M_TEMP); 1821 return (error); 1822 } 1823 1824 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1825 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1826 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1827 1828 #ifdef INET 1829 static int 1830 tcp_getcred(SYSCTL_HANDLER_ARGS) 1831 { 1832 struct xucred xuc; 1833 struct sockaddr_in addrs[2]; 1834 struct inpcb *inp; 1835 int error; 1836 1837 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1838 if (error) 1839 return (error); 1840 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1841 if (error) 1842 return (error); 1843 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1844 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1845 if (inp != NULL) { 1846 if (inp->inp_socket == NULL) 1847 error = ENOENT; 1848 if (error == 0) 1849 error = cr_canseeinpcb(req->td->td_ucred, inp); 1850 if (error == 0) 1851 cru2x(inp->inp_cred, &xuc); 1852 INP_RUNLOCK(inp); 1853 } else 1854 error = ENOENT; 1855 if (error == 0) 1856 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1857 return (error); 1858 } 1859 1860 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1861 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1862 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1863 #endif /* INET */ 1864 1865 #ifdef INET6 1866 static int 1867 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1868 { 1869 struct xucred xuc; 1870 struct sockaddr_in6 addrs[2]; 1871 struct inpcb *inp; 1872 int error; 1873 #ifdef INET 1874 int mapped = 0; 1875 #endif 1876 1877 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1878 if (error) 1879 return (error); 1880 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1881 if (error) 1882 return (error); 1883 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1884 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1885 return (error); 1886 } 1887 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1888 #ifdef INET 1889 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1890 mapped = 1; 1891 else 1892 #endif 1893 return (EINVAL); 1894 } 1895 1896 #ifdef INET 1897 if (mapped == 1) 1898 inp = in_pcblookup(&V_tcbinfo, 1899 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1900 addrs[1].sin6_port, 1901 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1902 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1903 else 1904 #endif 1905 inp = in6_pcblookup(&V_tcbinfo, 1906 &addrs[1].sin6_addr, addrs[1].sin6_port, 1907 &addrs[0].sin6_addr, addrs[0].sin6_port, 1908 INPLOOKUP_RLOCKPCB, NULL); 1909 if (inp != NULL) { 1910 if (inp->inp_socket == NULL) 1911 error = ENOENT; 1912 if (error == 0) 1913 error = cr_canseeinpcb(req->td->td_ucred, inp); 1914 if (error == 0) 1915 cru2x(inp->inp_cred, &xuc); 1916 INP_RUNLOCK(inp); 1917 } else 1918 error = ENOENT; 1919 if (error == 0) 1920 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1921 return (error); 1922 } 1923 1924 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1925 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1926 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1927 #endif /* INET6 */ 1928 1929 1930 #ifdef INET 1931 void 1932 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1933 { 1934 struct ip *ip = vip; 1935 struct tcphdr *th; 1936 struct in_addr faddr; 1937 struct inpcb *inp; 1938 struct tcpcb *tp; 1939 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1940 struct icmp *icp; 1941 struct in_conninfo inc; 1942 tcp_seq icmp_tcp_seq; 1943 int mtu; 1944 1945 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1946 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1947 return; 1948 1949 if (cmd == PRC_MSGSIZE) 1950 notify = tcp_mtudisc_notify; 1951 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1952 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1953 notify = tcp_drop_syn_sent; 1954 1955 /* 1956 * Hostdead is ugly because it goes linearly through all PCBs. 1957 * XXX: We never get this from ICMP, otherwise it makes an 1958 * excellent DoS attack on machines with many connections. 1959 */ 1960 else if (cmd == PRC_HOSTDEAD) 1961 ip = NULL; 1962 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1963 return; 1964 1965 if (ip == NULL) { 1966 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1967 return; 1968 } 1969 1970 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1971 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1972 INP_INFO_RLOCK(&V_tcbinfo); 1973 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1974 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1975 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 1976 /* signal EHOSTDOWN, as it flushes the cached route */ 1977 inp = (*notify)(inp, EHOSTDOWN); 1978 if (inp != NULL) 1979 INP_WUNLOCK(inp); 1980 } else if (inp != NULL) { 1981 if (!(inp->inp_flags & INP_TIMEWAIT) && 1982 !(inp->inp_flags & INP_DROPPED) && 1983 !(inp->inp_socket == NULL)) { 1984 icmp_tcp_seq = ntohl(th->th_seq); 1985 tp = intotcpcb(inp); 1986 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1987 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1988 if (cmd == PRC_MSGSIZE) { 1989 /* 1990 * MTU discovery: 1991 * If we got a needfrag set the MTU 1992 * in the route to the suggested new 1993 * value (if given) and then notify. 1994 */ 1995 mtu = ntohs(icp->icmp_nextmtu); 1996 /* 1997 * If no alternative MTU was 1998 * proposed, try the next smaller 1999 * one. 2000 */ 2001 if (!mtu) 2002 mtu = ip_next_mtu( 2003 ntohs(ip->ip_len), 1); 2004 if (mtu < V_tcp_minmss + 2005 sizeof(struct tcpiphdr)) 2006 mtu = V_tcp_minmss + 2007 sizeof(struct tcpiphdr); 2008 /* 2009 * Only process the offered MTU if it 2010 * is smaller than the current one. 2011 */ 2012 if (mtu < tp->t_maxseg + 2013 sizeof(struct tcpiphdr)) { 2014 bzero(&inc, sizeof(inc)); 2015 inc.inc_faddr = faddr; 2016 inc.inc_fibnum = 2017 inp->inp_inc.inc_fibnum; 2018 tcp_hc_updatemtu(&inc, mtu); 2019 tcp_mtudisc(inp, mtu); 2020 } 2021 } else 2022 inp = (*notify)(inp, 2023 inetctlerrmap[cmd]); 2024 } 2025 } 2026 if (inp != NULL) 2027 INP_WUNLOCK(inp); 2028 } else { 2029 bzero(&inc, sizeof(inc)); 2030 inc.inc_fport = th->th_dport; 2031 inc.inc_lport = th->th_sport; 2032 inc.inc_faddr = faddr; 2033 inc.inc_laddr = ip->ip_src; 2034 syncache_unreach(&inc, th); 2035 } 2036 INP_INFO_RUNLOCK(&V_tcbinfo); 2037 } 2038 #endif /* INET */ 2039 2040 #ifdef INET6 2041 void 2042 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2043 { 2044 struct in6_addr *dst; 2045 struct tcphdr *th; 2046 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2047 struct ip6_hdr *ip6; 2048 struct mbuf *m; 2049 struct inpcb *inp; 2050 struct tcpcb *tp; 2051 struct icmp6_hdr *icmp6; 2052 struct ip6ctlparam *ip6cp = NULL; 2053 const struct sockaddr_in6 *sa6_src = NULL; 2054 struct in_conninfo inc; 2055 tcp_seq icmp_tcp_seq; 2056 unsigned int mtu; 2057 unsigned int off; 2058 2059 2060 if (sa->sa_family != AF_INET6 || 2061 sa->sa_len != sizeof(struct sockaddr_in6)) 2062 return; 2063 2064 /* if the parameter is from icmp6, decode it. */ 2065 if (d != NULL) { 2066 ip6cp = (struct ip6ctlparam *)d; 2067 icmp6 = ip6cp->ip6c_icmp6; 2068 m = ip6cp->ip6c_m; 2069 ip6 = ip6cp->ip6c_ip6; 2070 off = ip6cp->ip6c_off; 2071 sa6_src = ip6cp->ip6c_src; 2072 dst = ip6cp->ip6c_finaldst; 2073 } else { 2074 m = NULL; 2075 ip6 = NULL; 2076 off = 0; /* fool gcc */ 2077 sa6_src = &sa6_any; 2078 dst = NULL; 2079 } 2080 2081 if (cmd == PRC_MSGSIZE) 2082 notify = tcp_mtudisc_notify; 2083 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2084 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && 2085 ip6 != NULL) 2086 notify = tcp_drop_syn_sent; 2087 2088 /* 2089 * Hostdead is ugly because it goes linearly through all PCBs. 2090 * XXX: We never get this from ICMP, otherwise it makes an 2091 * excellent DoS attack on machines with many connections. 2092 */ 2093 else if (cmd == PRC_HOSTDEAD) 2094 ip6 = NULL; 2095 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2096 return; 2097 2098 if (ip6 == NULL) { 2099 in6_pcbnotify(&V_tcbinfo, sa, 0, 2100 (const struct sockaddr *)sa6_src, 2101 0, cmd, NULL, notify); 2102 return; 2103 } 2104 2105 /* Check if we can safely get the ports from the tcp hdr */ 2106 if (m == NULL || 2107 (m->m_pkthdr.len < 2108 (int32_t) (off + offsetof(struct tcphdr, th_seq)))) { 2109 return; 2110 } 2111 2112 th = (struct tcphdr *) mtodo(ip6cp->ip6c_m, ip6cp->ip6c_off); 2113 INP_INFO_RLOCK(&V_tcbinfo); 2114 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, th->th_dport, 2115 &ip6->ip6_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2116 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2117 /* signal EHOSTDOWN, as it flushes the cached route */ 2118 inp = (*notify)(inp, EHOSTDOWN); 2119 if (inp != NULL) 2120 INP_WUNLOCK(inp); 2121 } else if (inp != NULL) { 2122 if (!(inp->inp_flags & INP_TIMEWAIT) && 2123 !(inp->inp_flags & INP_DROPPED) && 2124 !(inp->inp_socket == NULL)) { 2125 icmp_tcp_seq = ntohl(th->th_seq); 2126 tp = intotcpcb(inp); 2127 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 2128 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 2129 if (cmd == PRC_MSGSIZE) { 2130 /* 2131 * MTU discovery: 2132 * If we got a needfrag set the MTU 2133 * in the route to the suggested new 2134 * value (if given) and then notify. 2135 */ 2136 mtu = ntohl(icmp6->icmp6_mtu); 2137 /* 2138 * If no alternative MTU was 2139 * proposed, or the proposed 2140 * MTU was too small, set to 2141 * the min. 2142 */ 2143 if (mtu < IPV6_MMTU) 2144 mtu = IPV6_MMTU - 8; 2145 2146 2147 bzero(&inc, sizeof(inc)); 2148 inc.inc_fibnum = M_GETFIB(m); 2149 inc.inc_flags |= INC_ISIPV6; 2150 inc.inc6_faddr = *dst; 2151 if (in6_setscope(&inc.inc6_faddr, 2152 m->m_pkthdr.rcvif, NULL)) 2153 goto unlock_inp; 2154 2155 /* 2156 * Only process the offered MTU if it 2157 * is smaller than the current one. 2158 */ 2159 if (mtu < tp->t_maxseg + 2160 (sizeof (*th) + sizeof (*ip6))) { 2161 tcp_hc_updatemtu(&inc, mtu); 2162 tcp_mtudisc(inp, mtu); 2163 ICMP6STAT_INC(icp6s_pmtuchg); 2164 } 2165 } else 2166 inp = (*notify)(inp, 2167 inet6ctlerrmap[cmd]); 2168 } 2169 } 2170 unlock_inp: 2171 if (inp != NULL) 2172 INP_WUNLOCK(inp); 2173 } else { 2174 bzero(&inc, sizeof(inc)); 2175 inc.inc_fibnum = M_GETFIB(m); 2176 inc.inc_flags |= INC_ISIPV6; 2177 inc.inc_fport = th->th_dport; 2178 inc.inc_lport = th->th_sport; 2179 inc.inc6_faddr = *dst; 2180 inc.inc6_laddr = ip6->ip6_src; 2181 syncache_unreach(&inc, th); 2182 } 2183 INP_INFO_RUNLOCK(&V_tcbinfo); 2184 } 2185 #endif /* INET6 */ 2186 2187 2188 /* 2189 * Following is where TCP initial sequence number generation occurs. 2190 * 2191 * There are two places where we must use initial sequence numbers: 2192 * 1. In SYN-ACK packets. 2193 * 2. In SYN packets. 2194 * 2195 * All ISNs for SYN-ACK packets are generated by the syncache. See 2196 * tcp_syncache.c for details. 2197 * 2198 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2199 * depends on this property. In addition, these ISNs should be 2200 * unguessable so as to prevent connection hijacking. To satisfy 2201 * the requirements of this situation, the algorithm outlined in 2202 * RFC 1948 is used, with only small modifications. 2203 * 2204 * Implementation details: 2205 * 2206 * Time is based off the system timer, and is corrected so that it 2207 * increases by one megabyte per second. This allows for proper 2208 * recycling on high speed LANs while still leaving over an hour 2209 * before rollover. 2210 * 2211 * As reading the *exact* system time is too expensive to be done 2212 * whenever setting up a TCP connection, we increment the time 2213 * offset in two ways. First, a small random positive increment 2214 * is added to isn_offset for each connection that is set up. 2215 * Second, the function tcp_isn_tick fires once per clock tick 2216 * and increments isn_offset as necessary so that sequence numbers 2217 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2218 * random positive increments serve only to ensure that the same 2219 * exact sequence number is never sent out twice (as could otherwise 2220 * happen when a port is recycled in less than the system tick 2221 * interval.) 2222 * 2223 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2224 * between seeding of isn_secret. This is normally set to zero, 2225 * as reseeding should not be necessary. 2226 * 2227 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2228 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2229 * general, this means holding an exclusive (write) lock. 2230 */ 2231 2232 #define ISN_BYTES_PER_SECOND 1048576 2233 #define ISN_STATIC_INCREMENT 4096 2234 #define ISN_RANDOM_INCREMENT (4096 - 1) 2235 2236 static VNET_DEFINE(u_char, isn_secret[32]); 2237 static VNET_DEFINE(int, isn_last); 2238 static VNET_DEFINE(int, isn_last_reseed); 2239 static VNET_DEFINE(u_int32_t, isn_offset); 2240 static VNET_DEFINE(u_int32_t, isn_offset_old); 2241 2242 #define V_isn_secret VNET(isn_secret) 2243 #define V_isn_last VNET(isn_last) 2244 #define V_isn_last_reseed VNET(isn_last_reseed) 2245 #define V_isn_offset VNET(isn_offset) 2246 #define V_isn_offset_old VNET(isn_offset_old) 2247 2248 tcp_seq 2249 tcp_new_isn(struct tcpcb *tp) 2250 { 2251 MD5_CTX isn_ctx; 2252 u_int32_t md5_buffer[4]; 2253 tcp_seq new_isn; 2254 u_int32_t projected_offset; 2255 2256 INP_WLOCK_ASSERT(tp->t_inpcb); 2257 2258 ISN_LOCK(); 2259 /* Seed if this is the first use, reseed if requested. */ 2260 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2261 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2262 < (u_int)ticks))) { 2263 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2264 V_isn_last_reseed = ticks; 2265 } 2266 2267 /* Compute the md5 hash and return the ISN. */ 2268 MD5Init(&isn_ctx); 2269 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2270 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2271 #ifdef INET6 2272 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2273 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2274 sizeof(struct in6_addr)); 2275 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2276 sizeof(struct in6_addr)); 2277 } else 2278 #endif 2279 { 2280 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2281 sizeof(struct in_addr)); 2282 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2283 sizeof(struct in_addr)); 2284 } 2285 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2286 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2287 new_isn = (tcp_seq) md5_buffer[0]; 2288 V_isn_offset += ISN_STATIC_INCREMENT + 2289 (arc4random() & ISN_RANDOM_INCREMENT); 2290 if (ticks != V_isn_last) { 2291 projected_offset = V_isn_offset_old + 2292 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2293 if (SEQ_GT(projected_offset, V_isn_offset)) 2294 V_isn_offset = projected_offset; 2295 V_isn_offset_old = V_isn_offset; 2296 V_isn_last = ticks; 2297 } 2298 new_isn += V_isn_offset; 2299 ISN_UNLOCK(); 2300 return (new_isn); 2301 } 2302 2303 /* 2304 * When a specific ICMP unreachable message is received and the 2305 * connection state is SYN-SENT, drop the connection. This behavior 2306 * is controlled by the icmp_may_rst sysctl. 2307 */ 2308 struct inpcb * 2309 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2310 { 2311 struct tcpcb *tp; 2312 2313 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2314 INP_WLOCK_ASSERT(inp); 2315 2316 if ((inp->inp_flags & INP_TIMEWAIT) || 2317 (inp->inp_flags & INP_DROPPED)) 2318 return (inp); 2319 2320 tp = intotcpcb(inp); 2321 if (tp->t_state != TCPS_SYN_SENT) 2322 return (inp); 2323 2324 tp = tcp_drop(tp, errno); 2325 if (tp != NULL) 2326 return (inp); 2327 else 2328 return (NULL); 2329 } 2330 2331 /* 2332 * When `need fragmentation' ICMP is received, update our idea of the MSS 2333 * based on the new value. Also nudge TCP to send something, since we 2334 * know the packet we just sent was dropped. 2335 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2336 */ 2337 static struct inpcb * 2338 tcp_mtudisc_notify(struct inpcb *inp, int error) 2339 { 2340 2341 tcp_mtudisc(inp, -1); 2342 return (inp); 2343 } 2344 2345 static void 2346 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2347 { 2348 struct tcpcb *tp; 2349 struct socket *so; 2350 2351 INP_WLOCK_ASSERT(inp); 2352 if ((inp->inp_flags & INP_TIMEWAIT) || 2353 (inp->inp_flags & INP_DROPPED)) 2354 return; 2355 2356 tp = intotcpcb(inp); 2357 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2358 2359 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2360 2361 so = inp->inp_socket; 2362 SOCKBUF_LOCK(&so->so_snd); 2363 /* If the mss is larger than the socket buffer, decrease the mss. */ 2364 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2365 tp->t_maxseg = so->so_snd.sb_hiwat; 2366 SOCKBUF_UNLOCK(&so->so_snd); 2367 2368 TCPSTAT_INC(tcps_mturesent); 2369 tp->t_rtttime = 0; 2370 tp->snd_nxt = tp->snd_una; 2371 tcp_free_sackholes(tp); 2372 tp->snd_recover = tp->snd_max; 2373 if (tp->t_flags & TF_SACK_PERMIT) 2374 EXIT_FASTRECOVERY(tp->t_flags); 2375 tp->t_fb->tfb_tcp_output(tp); 2376 } 2377 2378 #ifdef INET 2379 /* 2380 * Look-up the routing entry to the peer of this inpcb. If no route 2381 * is found and it cannot be allocated, then return 0. This routine 2382 * is called by TCP routines that access the rmx structure and by 2383 * tcp_mss_update to get the peer/interface MTU. 2384 */ 2385 u_long 2386 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2387 { 2388 struct nhop4_extended nh4; 2389 struct ifnet *ifp; 2390 u_long maxmtu = 0; 2391 2392 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2393 2394 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2395 2396 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2397 NHR_REF, 0, &nh4) != 0) 2398 return (0); 2399 2400 ifp = nh4.nh_ifp; 2401 maxmtu = nh4.nh_mtu; 2402 2403 /* Report additional interface capabilities. */ 2404 if (cap != NULL) { 2405 if (ifp->if_capenable & IFCAP_TSO4 && 2406 ifp->if_hwassist & CSUM_TSO) { 2407 cap->ifcap |= CSUM_TSO; 2408 cap->tsomax = ifp->if_hw_tsomax; 2409 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2410 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2411 } 2412 } 2413 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2414 } 2415 return (maxmtu); 2416 } 2417 #endif /* INET */ 2418 2419 #ifdef INET6 2420 u_long 2421 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2422 { 2423 struct nhop6_extended nh6; 2424 struct in6_addr dst6; 2425 uint32_t scopeid; 2426 struct ifnet *ifp; 2427 u_long maxmtu = 0; 2428 2429 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2430 2431 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2432 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2433 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2434 0, &nh6) != 0) 2435 return (0); 2436 2437 ifp = nh6.nh_ifp; 2438 maxmtu = nh6.nh_mtu; 2439 2440 /* Report additional interface capabilities. */ 2441 if (cap != NULL) { 2442 if (ifp->if_capenable & IFCAP_TSO6 && 2443 ifp->if_hwassist & CSUM_TSO) { 2444 cap->ifcap |= CSUM_TSO; 2445 cap->tsomax = ifp->if_hw_tsomax; 2446 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2447 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2448 } 2449 } 2450 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2451 } 2452 2453 return (maxmtu); 2454 } 2455 #endif /* INET6 */ 2456 2457 /* 2458 * Calculate effective SMSS per RFC5681 definition for a given TCP 2459 * connection at its current state, taking into account SACK and etc. 2460 */ 2461 u_int 2462 tcp_maxseg(const struct tcpcb *tp) 2463 { 2464 u_int optlen; 2465 2466 if (tp->t_flags & TF_NOOPT) 2467 return (tp->t_maxseg); 2468 2469 /* 2470 * Here we have a simplified code from tcp_addoptions(), 2471 * without a proper loop, and having most of paddings hardcoded. 2472 * We might make mistakes with padding here in some edge cases, 2473 * but this is harmless, since result of tcp_maxseg() is used 2474 * only in cwnd and ssthresh estimations. 2475 */ 2476 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2477 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2478 if (tp->t_flags & TF_RCVD_TSTMP) 2479 optlen = TCPOLEN_TSTAMP_APPA; 2480 else 2481 optlen = 0; 2482 #ifdef TCP_SIGNATURE 2483 if (tp->t_flags & TF_SIGNATURE) 2484 optlen += PAD(TCPOLEN_SIGNATURE); 2485 #endif 2486 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2487 optlen += TCPOLEN_SACKHDR; 2488 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2489 optlen = PAD(optlen); 2490 } 2491 } else { 2492 if (tp->t_flags & TF_REQ_TSTMP) 2493 optlen = TCPOLEN_TSTAMP_APPA; 2494 else 2495 optlen = PAD(TCPOLEN_MAXSEG); 2496 if (tp->t_flags & TF_REQ_SCALE) 2497 optlen += PAD(TCPOLEN_WINDOW); 2498 #ifdef TCP_SIGNATURE 2499 if (tp->t_flags & TF_SIGNATURE) 2500 optlen += PAD(TCPOLEN_SIGNATURE); 2501 #endif 2502 if (tp->t_flags & TF_SACK_PERMIT) 2503 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2504 } 2505 #undef PAD 2506 optlen = min(optlen, TCP_MAXOLEN); 2507 return (tp->t_maxseg - optlen); 2508 } 2509 2510 #ifdef IPSEC 2511 /* compute ESP/AH header size for TCP, including outer IP header. */ 2512 size_t 2513 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2514 { 2515 struct inpcb *inp; 2516 struct mbuf *m; 2517 size_t hdrsiz; 2518 struct ip *ip; 2519 #ifdef INET6 2520 struct ip6_hdr *ip6; 2521 #endif 2522 struct tcphdr *th; 2523 2524 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2525 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2526 return (0); 2527 m = m_gethdr(M_NOWAIT, MT_DATA); 2528 if (!m) 2529 return (0); 2530 2531 #ifdef INET6 2532 if ((inp->inp_vflag & INP_IPV6) != 0) { 2533 ip6 = mtod(m, struct ip6_hdr *); 2534 th = (struct tcphdr *)(ip6 + 1); 2535 m->m_pkthdr.len = m->m_len = 2536 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2537 tcpip_fillheaders(inp, ip6, th); 2538 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2539 } else 2540 #endif /* INET6 */ 2541 { 2542 ip = mtod(m, struct ip *); 2543 th = (struct tcphdr *)(ip + 1); 2544 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2545 tcpip_fillheaders(inp, ip, th); 2546 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2547 } 2548 2549 m_free(m); 2550 return (hdrsiz); 2551 } 2552 #endif /* IPSEC */ 2553 2554 #ifdef TCP_SIGNATURE 2555 /* 2556 * Callback function invoked by m_apply() to digest TCP segment data 2557 * contained within an mbuf chain. 2558 */ 2559 static int 2560 tcp_signature_apply(void *fstate, void *data, u_int len) 2561 { 2562 2563 MD5Update(fstate, (u_char *)data, len); 2564 return (0); 2565 } 2566 2567 /* 2568 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2569 * search with the destination IP address, and a 'magic SPI' to be 2570 * determined by the application. This is hardcoded elsewhere to 1179 2571 */ 2572 struct secasvar * 2573 tcp_get_sav(struct mbuf *m, u_int direction) 2574 { 2575 union sockaddr_union dst; 2576 struct secasvar *sav; 2577 struct ip *ip; 2578 #ifdef INET6 2579 struct ip6_hdr *ip6; 2580 char ip6buf[INET6_ADDRSTRLEN]; 2581 #endif 2582 2583 /* Extract the destination from the IP header in the mbuf. */ 2584 bzero(&dst, sizeof(union sockaddr_union)); 2585 ip = mtod(m, struct ip *); 2586 #ifdef INET6 2587 ip6 = NULL; /* Make the compiler happy. */ 2588 #endif 2589 switch (ip->ip_v) { 2590 #ifdef INET 2591 case IPVERSION: 2592 dst.sa.sa_len = sizeof(struct sockaddr_in); 2593 dst.sa.sa_family = AF_INET; 2594 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2595 ip->ip_src : ip->ip_dst; 2596 break; 2597 #endif 2598 #ifdef INET6 2599 case (IPV6_VERSION >> 4): 2600 ip6 = mtod(m, struct ip6_hdr *); 2601 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2602 dst.sa.sa_family = AF_INET6; 2603 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2604 ip6->ip6_src : ip6->ip6_dst; 2605 break; 2606 #endif 2607 default: 2608 return (NULL); 2609 /* NOTREACHED */ 2610 break; 2611 } 2612 2613 /* Look up an SADB entry which matches the address of the peer. */ 2614 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2615 if (sav == NULL) { 2616 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2617 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2618 #ifdef INET6 2619 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2620 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2621 #endif 2622 "(unsupported)")); 2623 } 2624 2625 return (sav); 2626 } 2627 2628 /* 2629 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2630 * 2631 * Parameters: 2632 * m pointer to head of mbuf chain 2633 * len length of TCP segment data, excluding options 2634 * optlen length of TCP segment options 2635 * buf pointer to storage for computed MD5 digest 2636 * sav pointer to security assosiation 2637 * 2638 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2639 * When called from tcp_input(), we can be sure that th_sum has been 2640 * zeroed out and verified already. 2641 * 2642 * Releases reference to SADB key before return. 2643 * 2644 * Return 0 if successful, otherwise return -1. 2645 * 2646 */ 2647 int 2648 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2649 u_char *buf, struct secasvar *sav) 2650 { 2651 #ifdef INET 2652 struct ippseudo ippseudo; 2653 #endif 2654 MD5_CTX ctx; 2655 int doff; 2656 struct ip *ip; 2657 #ifdef INET 2658 struct ipovly *ipovly; 2659 #endif 2660 struct tcphdr *th; 2661 #ifdef INET6 2662 struct ip6_hdr *ip6; 2663 struct in6_addr in6; 2664 uint32_t plen; 2665 uint16_t nhdr; 2666 #endif 2667 u_short savecsum; 2668 2669 KASSERT(m != NULL, ("NULL mbuf chain")); 2670 KASSERT(buf != NULL, ("NULL signature pointer")); 2671 2672 /* Extract the destination from the IP header in the mbuf. */ 2673 ip = mtod(m, struct ip *); 2674 #ifdef INET6 2675 ip6 = NULL; /* Make the compiler happy. */ 2676 #endif 2677 2678 MD5Init(&ctx); 2679 /* 2680 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2681 * 2682 * XXX The ippseudo header MUST be digested in network byte order, 2683 * or else we'll fail the regression test. Assume all fields we've 2684 * been doing arithmetic on have been in host byte order. 2685 * XXX One cannot depend on ipovly->ih_len here. When called from 2686 * tcp_output(), the underlying ip_len member has not yet been set. 2687 */ 2688 switch (ip->ip_v) { 2689 #ifdef INET 2690 case IPVERSION: 2691 ipovly = (struct ipovly *)ip; 2692 ippseudo.ippseudo_src = ipovly->ih_src; 2693 ippseudo.ippseudo_dst = ipovly->ih_dst; 2694 ippseudo.ippseudo_pad = 0; 2695 ippseudo.ippseudo_p = IPPROTO_TCP; 2696 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2697 optlen); 2698 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2699 2700 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2701 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2702 break; 2703 #endif 2704 #ifdef INET6 2705 /* 2706 * RFC 2385, 2.0 Proposal 2707 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2708 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2709 * extended next header value (to form 32 bits), and 32-bit segment 2710 * length. 2711 * Note: Upper-Layer Packet Length comes before Next Header. 2712 */ 2713 case (IPV6_VERSION >> 4): 2714 in6 = ip6->ip6_src; 2715 in6_clearscope(&in6); 2716 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2717 in6 = ip6->ip6_dst; 2718 in6_clearscope(&in6); 2719 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2720 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2721 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2722 nhdr = 0; 2723 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2724 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2725 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2726 nhdr = IPPROTO_TCP; 2727 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2728 2729 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2730 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2731 break; 2732 #endif 2733 default: 2734 KEY_FREESAV(&sav); 2735 return (-1); 2736 /* NOTREACHED */ 2737 break; 2738 } 2739 2740 2741 /* 2742 * Step 2: Update MD5 hash with TCP header, excluding options. 2743 * The TCP checksum must be set to zero. 2744 */ 2745 savecsum = th->th_sum; 2746 th->th_sum = 0; 2747 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2748 th->th_sum = savecsum; 2749 2750 /* 2751 * Step 3: Update MD5 hash with TCP segment data. 2752 * Use m_apply() to avoid an early m_pullup(). 2753 */ 2754 if (len > 0) 2755 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2756 2757 /* 2758 * Step 4: Update MD5 hash with shared secret. 2759 */ 2760 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2761 MD5Final(buf, &ctx); 2762 2763 key_sa_recordxfer(sav, m); 2764 KEY_FREESAV(&sav); 2765 return (0); 2766 } 2767 2768 /* 2769 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2770 * 2771 * Return 0 if successful, otherwise return -1. 2772 */ 2773 int 2774 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2775 u_char *buf, u_int direction) 2776 { 2777 struct secasvar *sav; 2778 2779 if ((sav = tcp_get_sav(m, direction)) == NULL) 2780 return (-1); 2781 2782 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2783 } 2784 2785 /* 2786 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2787 * 2788 * Parameters: 2789 * m pointer to head of mbuf chain 2790 * len length of TCP segment data, excluding options 2791 * optlen length of TCP segment options 2792 * buf pointer to storage for computed MD5 digest 2793 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2794 * 2795 * Return 1 if successful, otherwise return 0. 2796 */ 2797 int 2798 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2799 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2800 { 2801 char tmpdigest[TCP_SIGLEN]; 2802 2803 if (tcp_sig_checksigs == 0) 2804 return (1); 2805 if ((tcpbflag & TF_SIGNATURE) == 0) { 2806 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2807 2808 /* 2809 * If this socket is not expecting signature but 2810 * the segment contains signature just fail. 2811 */ 2812 TCPSTAT_INC(tcps_sig_err_sigopt); 2813 TCPSTAT_INC(tcps_sig_rcvbadsig); 2814 return (0); 2815 } 2816 2817 /* Signature is not expected, and not present in segment. */ 2818 return (1); 2819 } 2820 2821 /* 2822 * If this socket is expecting signature but the segment does not 2823 * contain any just fail. 2824 */ 2825 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2826 TCPSTAT_INC(tcps_sig_err_nosigopt); 2827 TCPSTAT_INC(tcps_sig_rcvbadsig); 2828 return (0); 2829 } 2830 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2831 IPSEC_DIR_INBOUND) == -1) { 2832 TCPSTAT_INC(tcps_sig_err_buildsig); 2833 TCPSTAT_INC(tcps_sig_rcvbadsig); 2834 return (0); 2835 } 2836 2837 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2838 TCPSTAT_INC(tcps_sig_rcvbadsig); 2839 return (0); 2840 } 2841 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2842 return (1); 2843 } 2844 #endif /* TCP_SIGNATURE */ 2845 2846 static int 2847 sysctl_drop(SYSCTL_HANDLER_ARGS) 2848 { 2849 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2850 struct sockaddr_storage addrs[2]; 2851 struct inpcb *inp; 2852 struct tcpcb *tp; 2853 struct tcptw *tw; 2854 struct sockaddr_in *fin, *lin; 2855 #ifdef INET6 2856 struct sockaddr_in6 *fin6, *lin6; 2857 #endif 2858 int error; 2859 2860 inp = NULL; 2861 fin = lin = NULL; 2862 #ifdef INET6 2863 fin6 = lin6 = NULL; 2864 #endif 2865 error = 0; 2866 2867 if (req->oldptr != NULL || req->oldlen != 0) 2868 return (EINVAL); 2869 if (req->newptr == NULL) 2870 return (EPERM); 2871 if (req->newlen < sizeof(addrs)) 2872 return (ENOMEM); 2873 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2874 if (error) 2875 return (error); 2876 2877 switch (addrs[0].ss_family) { 2878 #ifdef INET6 2879 case AF_INET6: 2880 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2881 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2882 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2883 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2884 return (EINVAL); 2885 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2886 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2887 return (EINVAL); 2888 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2889 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2890 fin = (struct sockaddr_in *)&addrs[0]; 2891 lin = (struct sockaddr_in *)&addrs[1]; 2892 break; 2893 } 2894 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2895 if (error) 2896 return (error); 2897 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2898 if (error) 2899 return (error); 2900 break; 2901 #endif 2902 #ifdef INET 2903 case AF_INET: 2904 fin = (struct sockaddr_in *)&addrs[0]; 2905 lin = (struct sockaddr_in *)&addrs[1]; 2906 if (fin->sin_len != sizeof(struct sockaddr_in) || 2907 lin->sin_len != sizeof(struct sockaddr_in)) 2908 return (EINVAL); 2909 break; 2910 #endif 2911 default: 2912 return (EINVAL); 2913 } 2914 INP_INFO_RLOCK(&V_tcbinfo); 2915 switch (addrs[0].ss_family) { 2916 #ifdef INET6 2917 case AF_INET6: 2918 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2919 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2920 INPLOOKUP_WLOCKPCB, NULL); 2921 break; 2922 #endif 2923 #ifdef INET 2924 case AF_INET: 2925 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2926 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2927 break; 2928 #endif 2929 } 2930 if (inp != NULL) { 2931 if (inp->inp_flags & INP_TIMEWAIT) { 2932 /* 2933 * XXXRW: There currently exists a state where an 2934 * inpcb is present, but its timewait state has been 2935 * discarded. For now, don't allow dropping of this 2936 * type of inpcb. 2937 */ 2938 tw = intotw(inp); 2939 if (tw != NULL) 2940 tcp_twclose(tw, 0); 2941 else 2942 INP_WUNLOCK(inp); 2943 } else if (!(inp->inp_flags & INP_DROPPED) && 2944 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2945 tp = intotcpcb(inp); 2946 tp = tcp_drop(tp, ECONNABORTED); 2947 if (tp != NULL) 2948 INP_WUNLOCK(inp); 2949 } else 2950 INP_WUNLOCK(inp); 2951 } else 2952 error = ESRCH; 2953 INP_INFO_RUNLOCK(&V_tcbinfo); 2954 return (error); 2955 } 2956 2957 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2958 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2959 0, sysctl_drop, "", "Drop TCP connection"); 2960 2961 /* 2962 * Generate a standardized TCP log line for use throughout the 2963 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2964 * allow use in the interrupt context. 2965 * 2966 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2967 * NB: The function may return NULL if memory allocation failed. 2968 * 2969 * Due to header inclusion and ordering limitations the struct ip 2970 * and ip6_hdr pointers have to be passed as void pointers. 2971 */ 2972 char * 2973 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2974 const void *ip6hdr) 2975 { 2976 2977 /* Is logging enabled? */ 2978 if (tcp_log_in_vain == 0) 2979 return (NULL); 2980 2981 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2982 } 2983 2984 char * 2985 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2986 const void *ip6hdr) 2987 { 2988 2989 /* Is logging enabled? */ 2990 if (tcp_log_debug == 0) 2991 return (NULL); 2992 2993 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2994 } 2995 2996 static char * 2997 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2998 const void *ip6hdr) 2999 { 3000 char *s, *sp; 3001 size_t size; 3002 struct ip *ip; 3003 #ifdef INET6 3004 const struct ip6_hdr *ip6; 3005 3006 ip6 = (const struct ip6_hdr *)ip6hdr; 3007 #endif /* INET6 */ 3008 ip = (struct ip *)ip4hdr; 3009 3010 /* 3011 * The log line looks like this: 3012 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3013 */ 3014 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3015 sizeof(PRINT_TH_FLAGS) + 1 + 3016 #ifdef INET6 3017 2 * INET6_ADDRSTRLEN; 3018 #else 3019 2 * INET_ADDRSTRLEN; 3020 #endif /* INET6 */ 3021 3022 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3023 if (s == NULL) 3024 return (NULL); 3025 3026 strcat(s, "TCP: ["); 3027 sp = s + strlen(s); 3028 3029 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3030 inet_ntoa_r(inc->inc_faddr, sp); 3031 sp = s + strlen(s); 3032 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3033 sp = s + strlen(s); 3034 inet_ntoa_r(inc->inc_laddr, sp); 3035 sp = s + strlen(s); 3036 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3037 #ifdef INET6 3038 } else if (inc) { 3039 ip6_sprintf(sp, &inc->inc6_faddr); 3040 sp = s + strlen(s); 3041 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3042 sp = s + strlen(s); 3043 ip6_sprintf(sp, &inc->inc6_laddr); 3044 sp = s + strlen(s); 3045 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3046 } else if (ip6 && th) { 3047 ip6_sprintf(sp, &ip6->ip6_src); 3048 sp = s + strlen(s); 3049 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3050 sp = s + strlen(s); 3051 ip6_sprintf(sp, &ip6->ip6_dst); 3052 sp = s + strlen(s); 3053 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3054 #endif /* INET6 */ 3055 #ifdef INET 3056 } else if (ip && th) { 3057 inet_ntoa_r(ip->ip_src, sp); 3058 sp = s + strlen(s); 3059 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3060 sp = s + strlen(s); 3061 inet_ntoa_r(ip->ip_dst, sp); 3062 sp = s + strlen(s); 3063 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3064 #endif /* INET */ 3065 } else { 3066 free(s, M_TCPLOG); 3067 return (NULL); 3068 } 3069 sp = s + strlen(s); 3070 if (th) 3071 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3072 if (*(s + size - 1) != '\0') 3073 panic("%s: string too long", __func__); 3074 return (s); 3075 } 3076 3077 /* 3078 * A subroutine which makes it easy to track TCP state changes with DTrace. 3079 * This function shouldn't be called for t_state initializations that don't 3080 * correspond to actual TCP state transitions. 3081 */ 3082 void 3083 tcp_state_change(struct tcpcb *tp, int newstate) 3084 { 3085 #if defined(KDTRACE_HOOKS) 3086 int pstate = tp->t_state; 3087 #endif 3088 3089 TCPSTATES_DEC(tp->t_state); 3090 TCPSTATES_INC(newstate); 3091 tp->t_state = newstate; 3092 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3093 } 3094