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 #ifdef TCP_HHOOK 46 #include <sys/hhook.h> 47 #endif 48 #include <sys/kernel.h> 49 #ifdef TCP_HHOOK 50 #include <sys/khelp.h> 51 #endif 52 #include <sys/sysctl.h> 53 #include <sys/jail.h> 54 #include <sys/malloc.h> 55 #include <sys/refcount.h> 56 #include <sys/mbuf.h> 57 #ifdef INET6 58 #include <sys/domain.h> 59 #endif 60 #include <sys/priv.h> 61 #include <sys/proc.h> 62 #include <sys/sdt.h> 63 #include <sys/socket.h> 64 #include <sys/socketvar.h> 65 #include <sys/protosw.h> 66 #include <sys/random.h> 67 68 #include <vm/uma.h> 69 70 #include <net/route.h> 71 #include <net/if.h> 72 #include <net/if_var.h> 73 #include <net/vnet.h> 74 75 #include <netinet/in.h> 76 #include <netinet/in_fib.h> 77 #include <netinet/in_kdtrace.h> 78 #include <netinet/in_pcb.h> 79 #include <netinet/in_systm.h> 80 #include <netinet/in_var.h> 81 #include <netinet/ip.h> 82 #include <netinet/ip_icmp.h> 83 #include <netinet/ip_var.h> 84 #ifdef INET6 85 #include <netinet/icmp6.h> 86 #include <netinet/ip6.h> 87 #include <netinet6/in6_fib.h> 88 #include <netinet6/in6_pcb.h> 89 #include <netinet6/ip6_var.h> 90 #include <netinet6/scope6_var.h> 91 #include <netinet6/nd6.h> 92 #endif 93 94 #ifdef TCP_RFC7413 95 #include <netinet/tcp_fastopen.h> 96 #endif 97 #include <netinet/tcp.h> 98 #include <netinet/tcp_fsm.h> 99 #include <netinet/tcp_seq.h> 100 #include <netinet/tcp_timer.h> 101 #include <netinet/tcp_var.h> 102 #include <netinet/tcp_syncache.h> 103 #include <netinet/cc/cc.h> 104 #ifdef INET6 105 #include <netinet6/tcp6_var.h> 106 #endif 107 #include <netinet/tcpip.h> 108 #ifdef TCPPCAP 109 #include <netinet/tcp_pcap.h> 110 #endif 111 #ifdef TCPDEBUG 112 #include <netinet/tcp_debug.h> 113 #endif 114 #ifdef INET6 115 #include <netinet6/ip6protosw.h> 116 #endif 117 #ifdef TCP_OFFLOAD 118 #include <netinet/tcp_offload.h> 119 #endif 120 121 #ifdef IPSEC 122 #include <netipsec/ipsec.h> 123 #include <netipsec/xform.h> 124 #ifdef INET6 125 #include <netipsec/ipsec6.h> 126 #endif 127 #include <netipsec/key.h> 128 #include <sys/syslog.h> 129 #endif /*IPSEC*/ 130 131 #include <machine/in_cksum.h> 132 #include <sys/md5.h> 133 134 #include <security/mac/mac_framework.h> 135 136 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 137 #ifdef INET6 138 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 139 #endif 140 141 struct rwlock tcp_function_lock; 142 143 static int 144 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 145 { 146 int error, new; 147 148 new = V_tcp_mssdflt; 149 error = sysctl_handle_int(oidp, &new, 0, req); 150 if (error == 0 && req->newptr) { 151 if (new < TCP_MINMSS) 152 error = EINVAL; 153 else 154 V_tcp_mssdflt = new; 155 } 156 return (error); 157 } 158 159 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 160 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 161 &sysctl_net_inet_tcp_mss_check, "I", 162 "Default TCP Maximum Segment Size"); 163 164 #ifdef INET6 165 static int 166 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 167 { 168 int error, new; 169 170 new = V_tcp_v6mssdflt; 171 error = sysctl_handle_int(oidp, &new, 0, req); 172 if (error == 0 && req->newptr) { 173 if (new < TCP_MINMSS) 174 error = EINVAL; 175 else 176 V_tcp_v6mssdflt = new; 177 } 178 return (error); 179 } 180 181 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 182 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 183 &sysctl_net_inet_tcp_mss_v6_check, "I", 184 "Default TCP Maximum Segment Size for IPv6"); 185 #endif /* INET6 */ 186 187 /* 188 * Minimum MSS we accept and use. This prevents DoS attacks where 189 * we are forced to a ridiculous low MSS like 20 and send hundreds 190 * of packets instead of one. The effect scales with the available 191 * bandwidth and quickly saturates the CPU and network interface 192 * with packet generation and sending. Set to zero to disable MINMSS 193 * checking. This setting prevents us from sending too small packets. 194 */ 195 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 196 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 197 &VNET_NAME(tcp_minmss), 0, 198 "Minimum TCP Maximum Segment Size"); 199 200 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 201 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 202 &VNET_NAME(tcp_do_rfc1323), 0, 203 "Enable rfc1323 (high performance TCP) extensions"); 204 205 static int tcp_log_debug = 0; 206 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 207 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 208 209 static int tcp_tcbhashsize; 210 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 211 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 212 213 static int do_tcpdrain = 1; 214 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 215 "Enable tcp_drain routine for extra help when low on mbufs"); 216 217 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 218 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 219 220 static VNET_DEFINE(int, icmp_may_rst) = 1; 221 #define V_icmp_may_rst VNET(icmp_may_rst) 222 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 223 &VNET_NAME(icmp_may_rst), 0, 224 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 225 226 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 227 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 228 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 229 &VNET_NAME(tcp_isn_reseed_interval), 0, 230 "Seconds between reseeding of ISN secret"); 231 232 static int tcp_soreceive_stream; 233 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 234 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 235 236 #ifdef TCP_SIGNATURE 237 static int tcp_sig_checksigs = 1; 238 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 239 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 240 #endif 241 242 VNET_DEFINE(uma_zone_t, sack_hole_zone); 243 #define V_sack_hole_zone VNET(sack_hole_zone) 244 245 #ifdef TCP_HHOOK 246 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 247 #endif 248 249 static struct inpcb *tcp_notify(struct inpcb *, int); 250 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 251 static void tcp_mtudisc(struct inpcb *, int); 252 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 253 void *ip4hdr, const void *ip6hdr); 254 255 256 static struct tcp_function_block tcp_def_funcblk = { 257 "default", 258 tcp_output, 259 tcp_do_segment, 260 tcp_default_ctloutput, 261 NULL, 262 NULL, 263 NULL, 264 NULL, 265 NULL, 266 NULL, 267 0, 268 0 269 }; 270 271 int t_functions_inited = 0; 272 struct tcp_funchead t_functions; 273 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 274 275 static void 276 init_tcp_functions(void) 277 { 278 if (t_functions_inited == 0) { 279 TAILQ_INIT(&t_functions); 280 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 281 t_functions_inited = 1; 282 } 283 } 284 285 static struct tcp_function_block * 286 find_tcp_functions_locked(struct tcp_function_set *fs) 287 { 288 struct tcp_function *f; 289 struct tcp_function_block *blk=NULL; 290 291 TAILQ_FOREACH(f, &t_functions, tf_next) { 292 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 293 blk = f->tf_fb; 294 break; 295 } 296 } 297 return(blk); 298 } 299 300 static struct tcp_function_block * 301 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 302 { 303 struct tcp_function_block *rblk=NULL; 304 struct tcp_function *f; 305 306 TAILQ_FOREACH(f, &t_functions, tf_next) { 307 if (f->tf_fb == blk) { 308 rblk = blk; 309 if (s) { 310 *s = f; 311 } 312 break; 313 } 314 } 315 return (rblk); 316 } 317 318 struct tcp_function_block * 319 find_and_ref_tcp_functions(struct tcp_function_set *fs) 320 { 321 struct tcp_function_block *blk; 322 323 rw_rlock(&tcp_function_lock); 324 blk = find_tcp_functions_locked(fs); 325 if (blk) 326 refcount_acquire(&blk->tfb_refcnt); 327 rw_runlock(&tcp_function_lock); 328 return(blk); 329 } 330 331 struct tcp_function_block * 332 find_and_ref_tcp_fb(struct tcp_function_block *blk) 333 { 334 struct tcp_function_block *rblk; 335 336 rw_rlock(&tcp_function_lock); 337 rblk = find_tcp_fb_locked(blk, NULL); 338 if (rblk) 339 refcount_acquire(&rblk->tfb_refcnt); 340 rw_runlock(&tcp_function_lock); 341 return(rblk); 342 } 343 344 345 static int 346 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 347 { 348 int error=ENOENT; 349 struct tcp_function_set fs; 350 struct tcp_function_block *blk; 351 352 memset(&fs, 0, sizeof(fs)); 353 rw_rlock(&tcp_function_lock); 354 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 355 if (blk) { 356 /* Found him */ 357 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 358 fs.pcbcnt = blk->tfb_refcnt; 359 } 360 rw_runlock(&tcp_function_lock); 361 error = sysctl_handle_string(oidp, fs.function_set_name, 362 sizeof(fs.function_set_name), req); 363 364 /* Check for error or no change */ 365 if (error != 0 || req->newptr == NULL) 366 return(error); 367 368 rw_wlock(&tcp_function_lock); 369 blk = find_tcp_functions_locked(&fs); 370 if ((blk == NULL) || 371 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 372 error = ENOENT; 373 goto done; 374 } 375 tcp_func_set_ptr = blk; 376 done: 377 rw_wunlock(&tcp_function_lock); 378 return (error); 379 } 380 381 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 382 CTLTYPE_STRING | CTLFLAG_RW, 383 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 384 "Set/get the default TCP functions"); 385 386 static int 387 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 388 { 389 int error, cnt, linesz; 390 struct tcp_function *f; 391 char *buffer, *cp; 392 size_t bufsz, outsz; 393 394 cnt = 0; 395 rw_rlock(&tcp_function_lock); 396 TAILQ_FOREACH(f, &t_functions, tf_next) { 397 cnt++; 398 } 399 rw_runlock(&tcp_function_lock); 400 401 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 402 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 403 404 error = 0; 405 cp = buffer; 406 407 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 408 cp += linesz; 409 bufsz -= linesz; 410 outsz = linesz; 411 412 rw_rlock(&tcp_function_lock); 413 TAILQ_FOREACH(f, &t_functions, tf_next) { 414 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 415 f->tf_fb->tfb_tcp_block_name, 416 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 417 f->tf_fb->tfb_refcnt); 418 if (linesz >= bufsz) { 419 error = EOVERFLOW; 420 break; 421 } 422 cp += linesz; 423 bufsz -= linesz; 424 outsz += linesz; 425 } 426 rw_runlock(&tcp_function_lock); 427 if (error == 0) 428 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 429 free(buffer, M_TEMP); 430 return (error); 431 } 432 433 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 434 CTLTYPE_STRING|CTLFLAG_RD, 435 NULL, 0, sysctl_net_inet_list_available, "A", 436 "list available TCP Function sets"); 437 438 /* 439 * Target size of TCP PCB hash tables. Must be a power of two. 440 * 441 * Note that this can be overridden by the kernel environment 442 * variable net.inet.tcp.tcbhashsize 443 */ 444 #ifndef TCBHASHSIZE 445 #define TCBHASHSIZE 0 446 #endif 447 448 /* 449 * XXX 450 * Callouts should be moved into struct tcp directly. They are currently 451 * separate because the tcpcb structure is exported to userland for sysctl 452 * parsing purposes, which do not know about callouts. 453 */ 454 struct tcpcb_mem { 455 struct tcpcb tcb; 456 struct tcp_timer tt; 457 struct cc_var ccv; 458 #ifdef TCP_HHOOK 459 struct osd osd; 460 #endif 461 }; 462 463 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 464 #define V_tcpcb_zone VNET(tcpcb_zone) 465 466 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 467 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 468 469 static struct mtx isn_mtx; 470 471 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 472 #define ISN_LOCK() mtx_lock(&isn_mtx) 473 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 474 475 /* 476 * TCP initialization. 477 */ 478 static void 479 tcp_zone_change(void *tag) 480 { 481 482 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 483 uma_zone_set_max(V_tcpcb_zone, maxsockets); 484 tcp_tw_zone_change(); 485 } 486 487 static int 488 tcp_inpcb_init(void *mem, int size, int flags) 489 { 490 struct inpcb *inp = mem; 491 492 INP_LOCK_INIT(inp, "inp", "tcpinp"); 493 return (0); 494 } 495 496 /* 497 * Take a value and get the next power of 2 that doesn't overflow. 498 * Used to size the tcp_inpcb hash buckets. 499 */ 500 static int 501 maketcp_hashsize(int size) 502 { 503 int hashsize; 504 505 /* 506 * auto tune. 507 * get the next power of 2 higher than maxsockets. 508 */ 509 hashsize = 1 << fls(size); 510 /* catch overflow, and just go one power of 2 smaller */ 511 if (hashsize < size) { 512 hashsize = 1 << (fls(size) - 1); 513 } 514 return (hashsize); 515 } 516 517 int 518 register_tcp_functions(struct tcp_function_block *blk, int wait) 519 { 520 struct tcp_function_block *lblk; 521 struct tcp_function *n; 522 struct tcp_function_set fs; 523 524 if (t_functions_inited == 0) { 525 init_tcp_functions(); 526 } 527 if ((blk->tfb_tcp_output == NULL) || 528 (blk->tfb_tcp_do_segment == NULL) || 529 (blk->tfb_tcp_ctloutput == NULL) || 530 (strlen(blk->tfb_tcp_block_name) == 0)) { 531 /* 532 * These functions are required and you 533 * need a name. 534 */ 535 return (EINVAL); 536 } 537 if (blk->tfb_tcp_timer_stop_all || 538 blk->tfb_tcp_timer_activate || 539 blk->tfb_tcp_timer_active || 540 blk->tfb_tcp_timer_stop) { 541 /* 542 * If you define one timer function you 543 * must have them all. 544 */ 545 if ((blk->tfb_tcp_timer_stop_all == NULL) || 546 (blk->tfb_tcp_timer_activate == NULL) || 547 (blk->tfb_tcp_timer_active == NULL) || 548 (blk->tfb_tcp_timer_stop == NULL)) { 549 return (EINVAL); 550 } 551 } 552 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 553 if (n == NULL) { 554 return (ENOMEM); 555 } 556 n->tf_fb = blk; 557 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 558 rw_wlock(&tcp_function_lock); 559 lblk = find_tcp_functions_locked(&fs); 560 if (lblk) { 561 /* Duplicate name space not allowed */ 562 rw_wunlock(&tcp_function_lock); 563 free(n, M_TCPFUNCTIONS); 564 return (EALREADY); 565 } 566 refcount_init(&blk->tfb_refcnt, 0); 567 blk->tfb_flags = 0; 568 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 569 rw_wunlock(&tcp_function_lock); 570 return(0); 571 } 572 573 int 574 deregister_tcp_functions(struct tcp_function_block *blk) 575 { 576 struct tcp_function_block *lblk; 577 struct tcp_function *f; 578 int error=ENOENT; 579 580 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 581 /* You can't un-register the default */ 582 return (EPERM); 583 } 584 rw_wlock(&tcp_function_lock); 585 if (blk == tcp_func_set_ptr) { 586 /* You can't free the current default */ 587 rw_wunlock(&tcp_function_lock); 588 return (EBUSY); 589 } 590 if (blk->tfb_refcnt) { 591 /* Still tcb attached, mark it. */ 592 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 593 rw_wunlock(&tcp_function_lock); 594 return (EBUSY); 595 } 596 lblk = find_tcp_fb_locked(blk, &f); 597 if (lblk) { 598 /* Found */ 599 TAILQ_REMOVE(&t_functions, f, tf_next); 600 f->tf_fb = NULL; 601 free(f, M_TCPFUNCTIONS); 602 error = 0; 603 } 604 rw_wunlock(&tcp_function_lock); 605 return (error); 606 } 607 608 void 609 tcp_init(void) 610 { 611 const char *tcbhash_tuneable; 612 int hashsize; 613 614 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 615 616 #ifdef TCP_HHOOK 617 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 618 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 619 printf("%s: WARNING: unable to register helper hook\n", __func__); 620 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 621 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 622 printf("%s: WARNING: unable to register helper hook\n", __func__); 623 #endif 624 hashsize = TCBHASHSIZE; 625 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 626 if (hashsize == 0) { 627 /* 628 * Auto tune the hash size based on maxsockets. 629 * A perfect hash would have a 1:1 mapping 630 * (hashsize = maxsockets) however it's been 631 * suggested that O(2) average is better. 632 */ 633 hashsize = maketcp_hashsize(maxsockets / 4); 634 /* 635 * Our historical default is 512, 636 * do not autotune lower than this. 637 */ 638 if (hashsize < 512) 639 hashsize = 512; 640 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 641 printf("%s: %s auto tuned to %d\n", __func__, 642 tcbhash_tuneable, hashsize); 643 } 644 /* 645 * We require a hashsize to be a power of two. 646 * Previously if it was not a power of two we would just reset it 647 * back to 512, which could be a nasty surprise if you did not notice 648 * the error message. 649 * Instead what we do is clip it to the closest power of two lower 650 * than the specified hash value. 651 */ 652 if (!powerof2(hashsize)) { 653 int oldhashsize = hashsize; 654 655 hashsize = maketcp_hashsize(hashsize); 656 /* prevent absurdly low value */ 657 if (hashsize < 16) 658 hashsize = 16; 659 printf("%s: WARNING: TCB hash size not a power of 2, " 660 "clipped from %d to %d.\n", __func__, oldhashsize, 661 hashsize); 662 } 663 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 664 "tcp_inpcb", tcp_inpcb_init, NULL, 0, IPI_HASHFIELDS_4TUPLE); 665 666 /* 667 * These have to be type stable for the benefit of the timers. 668 */ 669 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 670 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 671 uma_zone_set_max(V_tcpcb_zone, maxsockets); 672 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 673 674 tcp_tw_init(); 675 syncache_init(); 676 tcp_hc_init(); 677 678 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 679 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 680 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 681 682 /* Skip initialization of globals for non-default instances. */ 683 if (!IS_DEFAULT_VNET(curvnet)) 684 return; 685 686 tcp_reass_global_init(); 687 688 /* XXX virtualize those bellow? */ 689 tcp_delacktime = TCPTV_DELACK; 690 tcp_keepinit = TCPTV_KEEP_INIT; 691 tcp_keepidle = TCPTV_KEEP_IDLE; 692 tcp_keepintvl = TCPTV_KEEPINTVL; 693 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 694 tcp_msl = TCPTV_MSL; 695 tcp_rexmit_min = TCPTV_MIN; 696 if (tcp_rexmit_min < 1) 697 tcp_rexmit_min = 1; 698 tcp_persmin = TCPTV_PERSMIN; 699 tcp_persmax = TCPTV_PERSMAX; 700 tcp_rexmit_slop = TCPTV_CPU_VAR; 701 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 702 tcp_tcbhashsize = hashsize; 703 /* Setup the tcp function block list */ 704 init_tcp_functions(); 705 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 706 707 if (tcp_soreceive_stream) { 708 #ifdef INET 709 tcp_usrreqs.pru_soreceive = soreceive_stream; 710 #endif 711 #ifdef INET6 712 tcp6_usrreqs.pru_soreceive = soreceive_stream; 713 #endif /* INET6 */ 714 } 715 716 #ifdef INET6 717 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 718 #else /* INET6 */ 719 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 720 #endif /* INET6 */ 721 if (max_protohdr < TCP_MINPROTOHDR) 722 max_protohdr = TCP_MINPROTOHDR; 723 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 724 panic("tcp_init"); 725 #undef TCP_MINPROTOHDR 726 727 ISN_LOCK_INIT(); 728 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 729 SHUTDOWN_PRI_DEFAULT); 730 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 731 EVENTHANDLER_PRI_ANY); 732 #ifdef TCPPCAP 733 tcp_pcap_init(); 734 #endif 735 736 #ifdef TCP_RFC7413 737 tcp_fastopen_init(); 738 #endif 739 } 740 741 #ifdef VIMAGE 742 static void 743 tcp_destroy(void *unused __unused) 744 { 745 int n; 746 #ifdef TCP_HHOOK 747 int error; 748 #endif 749 750 /* 751 * All our processes are gone, all our sockets should be cleaned 752 * up, which means, we should be past the tcp_discardcb() calls. 753 * Sleep to let all tcpcb timers really disappear and cleanup. 754 */ 755 for (;;) { 756 INP_LIST_RLOCK(&V_tcbinfo); 757 n = V_tcbinfo.ipi_count; 758 INP_LIST_RUNLOCK(&V_tcbinfo); 759 if (n == 0) 760 break; 761 pause("tcpdes", hz / 10); 762 } 763 tcp_hc_destroy(); 764 syncache_destroy(); 765 tcp_tw_destroy(); 766 in_pcbinfo_destroy(&V_tcbinfo); 767 /* tcp_discardcb() clears the sack_holes up. */ 768 uma_zdestroy(V_sack_hole_zone); 769 uma_zdestroy(V_tcpcb_zone); 770 771 #ifdef TCP_RFC7413 772 /* 773 * Cannot free the zone until all tcpcbs are released as we attach 774 * the allocations to them. 775 */ 776 tcp_fastopen_destroy(); 777 #endif 778 779 #ifdef TCP_HHOOK 780 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 781 if (error != 0) { 782 printf("%s: WARNING: unable to deregister helper hook " 783 "type=%d, id=%d: error %d returned\n", __func__, 784 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 785 } 786 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 787 if (error != 0) { 788 printf("%s: WARNING: unable to deregister helper hook " 789 "type=%d, id=%d: error %d returned\n", __func__, 790 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 791 } 792 #endif 793 } 794 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 795 #endif 796 797 void 798 tcp_fini(void *xtp) 799 { 800 801 } 802 803 /* 804 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 805 * tcp_template used to store this data in mbufs, but we now recopy it out 806 * of the tcpcb each time to conserve mbufs. 807 */ 808 void 809 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 810 { 811 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 812 813 INP_WLOCK_ASSERT(inp); 814 815 #ifdef INET6 816 if ((inp->inp_vflag & INP_IPV6) != 0) { 817 struct ip6_hdr *ip6; 818 819 ip6 = (struct ip6_hdr *)ip_ptr; 820 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 821 (inp->inp_flow & IPV6_FLOWINFO_MASK); 822 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 823 (IPV6_VERSION & IPV6_VERSION_MASK); 824 ip6->ip6_nxt = IPPROTO_TCP; 825 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 826 ip6->ip6_src = inp->in6p_laddr; 827 ip6->ip6_dst = inp->in6p_faddr; 828 } 829 #endif /* INET6 */ 830 #if defined(INET6) && defined(INET) 831 else 832 #endif 833 #ifdef INET 834 { 835 struct ip *ip; 836 837 ip = (struct ip *)ip_ptr; 838 ip->ip_v = IPVERSION; 839 ip->ip_hl = 5; 840 ip->ip_tos = inp->inp_ip_tos; 841 ip->ip_len = 0; 842 ip->ip_id = 0; 843 ip->ip_off = 0; 844 ip->ip_ttl = inp->inp_ip_ttl; 845 ip->ip_sum = 0; 846 ip->ip_p = IPPROTO_TCP; 847 ip->ip_src = inp->inp_laddr; 848 ip->ip_dst = inp->inp_faddr; 849 } 850 #endif /* INET */ 851 th->th_sport = inp->inp_lport; 852 th->th_dport = inp->inp_fport; 853 th->th_seq = 0; 854 th->th_ack = 0; 855 th->th_x2 = 0; 856 th->th_off = 5; 857 th->th_flags = 0; 858 th->th_win = 0; 859 th->th_urp = 0; 860 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 861 } 862 863 /* 864 * Create template to be used to send tcp packets on a connection. 865 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 866 * use for this function is in keepalives, which use tcp_respond. 867 */ 868 struct tcptemp * 869 tcpip_maketemplate(struct inpcb *inp) 870 { 871 struct tcptemp *t; 872 873 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 874 if (t == NULL) 875 return (NULL); 876 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 877 return (t); 878 } 879 880 /* 881 * Send a single message to the TCP at address specified by 882 * the given TCP/IP header. If m == NULL, then we make a copy 883 * of the tcpiphdr at th and send directly to the addressed host. 884 * This is used to force keep alive messages out using the TCP 885 * template for a connection. If flags are given then we send 886 * a message back to the TCP which originated the segment th, 887 * and discard the mbuf containing it and any other attached mbufs. 888 * 889 * In any case the ack and sequence number of the transmitted 890 * segment are as specified by the parameters. 891 * 892 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 893 */ 894 void 895 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 896 tcp_seq ack, tcp_seq seq, int flags) 897 { 898 struct tcpopt to; 899 struct inpcb *inp; 900 struct ip *ip; 901 struct mbuf *optm; 902 struct tcphdr *nth; 903 u_char *optp; 904 #ifdef INET6 905 struct ip6_hdr *ip6; 906 int isipv6; 907 #endif /* INET6 */ 908 int optlen, tlen, win; 909 bool incl_opts; 910 911 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 912 913 #ifdef INET6 914 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 915 ip6 = ipgen; 916 #endif /* INET6 */ 917 ip = ipgen; 918 919 if (tp != NULL) { 920 inp = tp->t_inpcb; 921 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 922 INP_WLOCK_ASSERT(inp); 923 } else 924 inp = NULL; 925 926 incl_opts = false; 927 win = 0; 928 if (tp != NULL) { 929 if (!(flags & TH_RST)) { 930 win = sbspace(&inp->inp_socket->so_rcv); 931 if (win > TCP_MAXWIN << tp->rcv_scale) 932 win = TCP_MAXWIN << tp->rcv_scale; 933 } 934 if ((tp->t_flags & TF_NOOPT) == 0) 935 incl_opts = true; 936 } 937 if (m == NULL) { 938 m = m_gethdr(M_NOWAIT, MT_DATA); 939 if (m == NULL) 940 return; 941 m->m_data += max_linkhdr; 942 #ifdef INET6 943 if (isipv6) { 944 bcopy((caddr_t)ip6, mtod(m, caddr_t), 945 sizeof(struct ip6_hdr)); 946 ip6 = mtod(m, struct ip6_hdr *); 947 nth = (struct tcphdr *)(ip6 + 1); 948 } else 949 #endif /* INET6 */ 950 { 951 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 952 ip = mtod(m, struct ip *); 953 nth = (struct tcphdr *)(ip + 1); 954 } 955 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 956 flags = TH_ACK; 957 } else if (!M_WRITABLE(m)) { 958 struct mbuf *n; 959 960 /* Can't reuse 'm', allocate a new mbuf. */ 961 n = m_gethdr(M_NOWAIT, MT_DATA); 962 if (n == NULL) { 963 m_freem(m); 964 return; 965 } 966 967 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 968 m_freem(m); 969 m_freem(n); 970 return; 971 } 972 973 n->m_data += max_linkhdr; 974 /* m_len is set later */ 975 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 976 #ifdef INET6 977 if (isipv6) { 978 bcopy((caddr_t)ip6, mtod(n, caddr_t), 979 sizeof(struct ip6_hdr)); 980 ip6 = mtod(n, struct ip6_hdr *); 981 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 982 nth = (struct tcphdr *)(ip6 + 1); 983 } else 984 #endif /* INET6 */ 985 { 986 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 987 ip = mtod(n, struct ip *); 988 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 989 nth = (struct tcphdr *)(ip + 1); 990 } 991 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 992 xchg(nth->th_dport, nth->th_sport, uint16_t); 993 th = nth; 994 m_freem(m); 995 m = n; 996 } else { 997 /* 998 * reuse the mbuf. 999 * XXX MRT We inherit the FIB, which is lucky. 1000 */ 1001 m_freem(m->m_next); 1002 m->m_next = NULL; 1003 m->m_data = (caddr_t)ipgen; 1004 /* m_len is set later */ 1005 #ifdef INET6 1006 if (isipv6) { 1007 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1008 nth = (struct tcphdr *)(ip6 + 1); 1009 } else 1010 #endif /* INET6 */ 1011 { 1012 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1013 nth = (struct tcphdr *)(ip + 1); 1014 } 1015 if (th != nth) { 1016 /* 1017 * this is usually a case when an extension header 1018 * exists between the IPv6 header and the 1019 * TCP header. 1020 */ 1021 nth->th_sport = th->th_sport; 1022 nth->th_dport = th->th_dport; 1023 } 1024 xchg(nth->th_dport, nth->th_sport, uint16_t); 1025 #undef xchg 1026 } 1027 tlen = 0; 1028 #ifdef INET6 1029 if (isipv6) 1030 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1031 #endif 1032 #if defined(INET) && defined(INET6) 1033 else 1034 #endif 1035 #ifdef INET 1036 tlen = sizeof (struct tcpiphdr); 1037 #endif 1038 #ifdef INVARIANTS 1039 m->m_len = 0; 1040 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1041 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1042 m, tlen, (long)M_TRAILINGSPACE(m))); 1043 #endif 1044 m->m_len = tlen; 1045 to.to_flags = 0; 1046 if (incl_opts) { 1047 /* Make sure we have room. */ 1048 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1049 m->m_next = m_get(M_NOWAIT, MT_DATA); 1050 if (m->m_next) { 1051 optp = mtod(m->m_next, u_char *); 1052 optm = m->m_next; 1053 } else 1054 incl_opts = false; 1055 } else { 1056 optp = (u_char *) (nth + 1); 1057 optm = m; 1058 } 1059 } 1060 if (incl_opts) { 1061 /* Timestamps. */ 1062 if (tp->t_flags & TF_RCVD_TSTMP) { 1063 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1064 to.to_tsecr = tp->ts_recent; 1065 to.to_flags |= TOF_TS; 1066 } 1067 #ifdef TCP_SIGNATURE 1068 /* TCP-MD5 (RFC2385). */ 1069 if (tp->t_flags & TF_SIGNATURE) 1070 to.to_flags |= TOF_SIGNATURE; 1071 #endif 1072 1073 /* Add the options. */ 1074 tlen += optlen = tcp_addoptions(&to, optp); 1075 1076 /* Update m_len in the correct mbuf. */ 1077 optm->m_len += optlen; 1078 } else 1079 optlen = 0; 1080 #ifdef INET6 1081 if (isipv6) { 1082 ip6->ip6_flow = 0; 1083 ip6->ip6_vfc = IPV6_VERSION; 1084 ip6->ip6_nxt = IPPROTO_TCP; 1085 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1086 } 1087 #endif 1088 #if defined(INET) && defined(INET6) 1089 else 1090 #endif 1091 #ifdef INET 1092 { 1093 ip->ip_len = htons(tlen); 1094 ip->ip_ttl = V_ip_defttl; 1095 if (V_path_mtu_discovery) 1096 ip->ip_off |= htons(IP_DF); 1097 } 1098 #endif 1099 m->m_pkthdr.len = tlen; 1100 m->m_pkthdr.rcvif = NULL; 1101 #ifdef MAC 1102 if (inp != NULL) { 1103 /* 1104 * Packet is associated with a socket, so allow the 1105 * label of the response to reflect the socket label. 1106 */ 1107 INP_WLOCK_ASSERT(inp); 1108 mac_inpcb_create_mbuf(inp, m); 1109 } else { 1110 /* 1111 * Packet is not associated with a socket, so possibly 1112 * update the label in place. 1113 */ 1114 mac_netinet_tcp_reply(m); 1115 } 1116 #endif 1117 nth->th_seq = htonl(seq); 1118 nth->th_ack = htonl(ack); 1119 nth->th_x2 = 0; 1120 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1121 nth->th_flags = flags; 1122 if (tp != NULL) 1123 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1124 else 1125 nth->th_win = htons((u_short)win); 1126 nth->th_urp = 0; 1127 1128 #ifdef TCP_SIGNATURE 1129 if (to.to_flags & TOF_SIGNATURE) { 1130 tcp_signature_compute(m, 0, 0, optlen, to.to_signature, 1131 IPSEC_DIR_OUTBOUND); 1132 } 1133 #endif 1134 1135 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1136 #ifdef INET6 1137 if (isipv6) { 1138 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1139 nth->th_sum = in6_cksum_pseudo(ip6, 1140 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1141 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1142 NULL, NULL); 1143 } 1144 #endif /* INET6 */ 1145 #if defined(INET6) && defined(INET) 1146 else 1147 #endif 1148 #ifdef INET 1149 { 1150 m->m_pkthdr.csum_flags = CSUM_TCP; 1151 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1152 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1153 } 1154 #endif /* INET */ 1155 #ifdef TCPDEBUG 1156 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1157 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1158 #endif 1159 TCP_PROBE3(debug__output, tp, th, mtod(m, const char *)); 1160 if (flags & TH_RST) 1161 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 1162 tp, nth); 1163 1164 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 1165 #ifdef INET6 1166 if (isipv6) 1167 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1168 #endif /* INET6 */ 1169 #if defined(INET) && defined(INET6) 1170 else 1171 #endif 1172 #ifdef INET 1173 (void) ip_output(m, NULL, NULL, 0, NULL, inp); 1174 #endif 1175 } 1176 1177 /* 1178 * Create a new TCP control block, making an 1179 * empty reassembly queue and hooking it to the argument 1180 * protocol control block. The `inp' parameter must have 1181 * come from the zone allocator set up in tcp_init(). 1182 */ 1183 struct tcpcb * 1184 tcp_newtcpcb(struct inpcb *inp) 1185 { 1186 struct tcpcb_mem *tm; 1187 struct tcpcb *tp; 1188 #ifdef INET6 1189 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1190 #endif /* INET6 */ 1191 1192 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1193 if (tm == NULL) 1194 return (NULL); 1195 tp = &tm->tcb; 1196 1197 /* Initialise cc_var struct for this tcpcb. */ 1198 tp->ccv = &tm->ccv; 1199 tp->ccv->type = IPPROTO_TCP; 1200 tp->ccv->ccvc.tcp = tp; 1201 rw_rlock(&tcp_function_lock); 1202 tp->t_fb = tcp_func_set_ptr; 1203 refcount_acquire(&tp->t_fb->tfb_refcnt); 1204 rw_runlock(&tcp_function_lock); 1205 /* 1206 * Use the current system default CC algorithm. 1207 */ 1208 CC_LIST_RLOCK(); 1209 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1210 CC_ALGO(tp) = CC_DEFAULT(); 1211 CC_LIST_RUNLOCK(); 1212 1213 if (CC_ALGO(tp)->cb_init != NULL) 1214 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1215 if (tp->t_fb->tfb_tcp_fb_fini) 1216 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1217 refcount_release(&tp->t_fb->tfb_refcnt); 1218 uma_zfree(V_tcpcb_zone, tm); 1219 return (NULL); 1220 } 1221 1222 #ifdef TCP_HHOOK 1223 tp->osd = &tm->osd; 1224 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1225 if (tp->t_fb->tfb_tcp_fb_fini) 1226 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1227 refcount_release(&tp->t_fb->tfb_refcnt); 1228 uma_zfree(V_tcpcb_zone, tm); 1229 return (NULL); 1230 } 1231 #endif 1232 1233 #ifdef VIMAGE 1234 tp->t_vnet = inp->inp_vnet; 1235 #endif 1236 tp->t_timers = &tm->tt; 1237 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1238 tp->t_maxseg = 1239 #ifdef INET6 1240 isipv6 ? V_tcp_v6mssdflt : 1241 #endif /* INET6 */ 1242 V_tcp_mssdflt; 1243 1244 /* Set up our timeouts. */ 1245 callout_init(&tp->t_timers->tt_rexmt, 1); 1246 callout_init(&tp->t_timers->tt_persist, 1); 1247 callout_init(&tp->t_timers->tt_keep, 1); 1248 callout_init(&tp->t_timers->tt_2msl, 1); 1249 callout_init(&tp->t_timers->tt_delack, 1); 1250 1251 if (V_tcp_do_rfc1323) 1252 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1253 if (V_tcp_do_sack) 1254 tp->t_flags |= TF_SACK_PERMIT; 1255 TAILQ_INIT(&tp->snd_holes); 1256 /* 1257 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1258 * is called. 1259 */ 1260 in_pcbref(inp); /* Reference for tcpcb */ 1261 tp->t_inpcb = inp; 1262 1263 /* 1264 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1265 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1266 * reasonable initial retransmit time. 1267 */ 1268 tp->t_srtt = TCPTV_SRTTBASE; 1269 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1270 tp->t_rttmin = tcp_rexmit_min; 1271 tp->t_rxtcur = TCPTV_RTOBASE; 1272 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1273 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1274 tp->t_rcvtime = ticks; 1275 /* 1276 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1277 * because the socket may be bound to an IPv6 wildcard address, 1278 * which may match an IPv4-mapped IPv6 address. 1279 */ 1280 inp->inp_ip_ttl = V_ip_defttl; 1281 inp->inp_ppcb = tp; 1282 #ifdef TCPPCAP 1283 /* 1284 * Init the TCP PCAP queues. 1285 */ 1286 tcp_pcap_tcpcb_init(tp); 1287 #endif 1288 if (tp->t_fb->tfb_tcp_fb_init) { 1289 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1290 } 1291 return (tp); /* XXX */ 1292 } 1293 1294 /* 1295 * Switch the congestion control algorithm back to NewReno for any active 1296 * control blocks using an algorithm which is about to go away. 1297 * This ensures the CC framework can allow the unload to proceed without leaving 1298 * any dangling pointers which would trigger a panic. 1299 * Returning non-zero would inform the CC framework that something went wrong 1300 * and it would be unsafe to allow the unload to proceed. However, there is no 1301 * way for this to occur with this implementation so we always return zero. 1302 */ 1303 int 1304 tcp_ccalgounload(struct cc_algo *unload_algo) 1305 { 1306 struct cc_algo *tmpalgo; 1307 struct inpcb *inp; 1308 struct tcpcb *tp; 1309 VNET_ITERATOR_DECL(vnet_iter); 1310 1311 /* 1312 * Check all active control blocks across all network stacks and change 1313 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1314 * requires cleanup code to be run, call it. 1315 */ 1316 VNET_LIST_RLOCK(); 1317 VNET_FOREACH(vnet_iter) { 1318 CURVNET_SET(vnet_iter); 1319 INP_INFO_WLOCK(&V_tcbinfo); 1320 /* 1321 * New connections already part way through being initialised 1322 * with the CC algo we're removing will not race with this code 1323 * because the INP_INFO_WLOCK is held during initialisation. We 1324 * therefore don't enter the loop below until the connection 1325 * list has stabilised. 1326 */ 1327 LIST_FOREACH(inp, &V_tcb, inp_list) { 1328 INP_WLOCK(inp); 1329 /* Important to skip tcptw structs. */ 1330 if (!(inp->inp_flags & INP_TIMEWAIT) && 1331 (tp = intotcpcb(inp)) != NULL) { 1332 /* 1333 * By holding INP_WLOCK here, we are assured 1334 * that the connection is not currently 1335 * executing inside the CC module's functions 1336 * i.e. it is safe to make the switch back to 1337 * NewReno. 1338 */ 1339 if (CC_ALGO(tp) == unload_algo) { 1340 tmpalgo = CC_ALGO(tp); 1341 /* NewReno does not require any init. */ 1342 CC_ALGO(tp) = &newreno_cc_algo; 1343 if (tmpalgo->cb_destroy != NULL) 1344 tmpalgo->cb_destroy(tp->ccv); 1345 } 1346 } 1347 INP_WUNLOCK(inp); 1348 } 1349 INP_INFO_WUNLOCK(&V_tcbinfo); 1350 CURVNET_RESTORE(); 1351 } 1352 VNET_LIST_RUNLOCK(); 1353 1354 return (0); 1355 } 1356 1357 /* 1358 * Drop a TCP connection, reporting 1359 * the specified error. If connection is synchronized, 1360 * then send a RST to peer. 1361 */ 1362 struct tcpcb * 1363 tcp_drop(struct tcpcb *tp, int errno) 1364 { 1365 struct socket *so = tp->t_inpcb->inp_socket; 1366 1367 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1368 INP_WLOCK_ASSERT(tp->t_inpcb); 1369 1370 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1371 tcp_state_change(tp, TCPS_CLOSED); 1372 (void) tp->t_fb->tfb_tcp_output(tp); 1373 TCPSTAT_INC(tcps_drops); 1374 } else 1375 TCPSTAT_INC(tcps_conndrops); 1376 if (errno == ETIMEDOUT && tp->t_softerror) 1377 errno = tp->t_softerror; 1378 so->so_error = errno; 1379 return (tcp_close(tp)); 1380 } 1381 1382 void 1383 tcp_discardcb(struct tcpcb *tp) 1384 { 1385 struct inpcb *inp = tp->t_inpcb; 1386 struct socket *so = inp->inp_socket; 1387 #ifdef INET6 1388 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1389 #endif /* INET6 */ 1390 int released; 1391 1392 INP_WLOCK_ASSERT(inp); 1393 1394 /* 1395 * Make sure that all of our timers are stopped before we delete the 1396 * PCB. 1397 * 1398 * If stopping a timer fails, we schedule a discard function in same 1399 * callout, and the last discard function called will take care of 1400 * deleting the tcpcb. 1401 */ 1402 tp->t_timers->tt_draincnt = 0; 1403 tcp_timer_stop(tp, TT_REXMT); 1404 tcp_timer_stop(tp, TT_PERSIST); 1405 tcp_timer_stop(tp, TT_KEEP); 1406 tcp_timer_stop(tp, TT_2MSL); 1407 tcp_timer_stop(tp, TT_DELACK); 1408 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1409 /* 1410 * Call the stop-all function of the methods, 1411 * this function should call the tcp_timer_stop() 1412 * method with each of the function specific timeouts. 1413 * That stop will be called via the tfb_tcp_timer_stop() 1414 * which should use the async drain function of the 1415 * callout system (see tcp_var.h). 1416 */ 1417 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1418 } 1419 1420 /* 1421 * If we got enough samples through the srtt filter, 1422 * save the rtt and rttvar in the routing entry. 1423 * 'Enough' is arbitrarily defined as 4 rtt samples. 1424 * 4 samples is enough for the srtt filter to converge 1425 * to within enough % of the correct value; fewer samples 1426 * and we could save a bogus rtt. The danger is not high 1427 * as tcp quickly recovers from everything. 1428 * XXX: Works very well but needs some more statistics! 1429 */ 1430 if (tp->t_rttupdated >= 4) { 1431 struct hc_metrics_lite metrics; 1432 uint32_t ssthresh; 1433 1434 bzero(&metrics, sizeof(metrics)); 1435 /* 1436 * Update the ssthresh always when the conditions below 1437 * are satisfied. This gives us better new start value 1438 * for the congestion avoidance for new connections. 1439 * ssthresh is only set if packet loss occurred on a session. 1440 * 1441 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1442 * being torn down. Ideally this code would not use 'so'. 1443 */ 1444 ssthresh = tp->snd_ssthresh; 1445 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1446 /* 1447 * convert the limit from user data bytes to 1448 * packets then to packet data bytes. 1449 */ 1450 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1451 if (ssthresh < 2) 1452 ssthresh = 2; 1453 ssthresh *= (tp->t_maxseg + 1454 #ifdef INET6 1455 (isipv6 ? sizeof (struct ip6_hdr) + 1456 sizeof (struct tcphdr) : 1457 #endif 1458 sizeof (struct tcpiphdr) 1459 #ifdef INET6 1460 ) 1461 #endif 1462 ); 1463 } else 1464 ssthresh = 0; 1465 metrics.rmx_ssthresh = ssthresh; 1466 1467 metrics.rmx_rtt = tp->t_srtt; 1468 metrics.rmx_rttvar = tp->t_rttvar; 1469 metrics.rmx_cwnd = tp->snd_cwnd; 1470 metrics.rmx_sendpipe = 0; 1471 metrics.rmx_recvpipe = 0; 1472 1473 tcp_hc_update(&inp->inp_inc, &metrics); 1474 } 1475 1476 /* free the reassembly queue, if any */ 1477 tcp_reass_flush(tp); 1478 1479 #ifdef TCP_OFFLOAD 1480 /* Disconnect offload device, if any. */ 1481 if (tp->t_flags & TF_TOE) 1482 tcp_offload_detach(tp); 1483 #endif 1484 1485 tcp_free_sackholes(tp); 1486 1487 #ifdef TCPPCAP 1488 /* Free the TCP PCAP queues. */ 1489 tcp_pcap_drain(&(tp->t_inpkts)); 1490 tcp_pcap_drain(&(tp->t_outpkts)); 1491 #endif 1492 1493 /* Allow the CC algorithm to clean up after itself. */ 1494 if (CC_ALGO(tp)->cb_destroy != NULL) 1495 CC_ALGO(tp)->cb_destroy(tp->ccv); 1496 1497 #ifdef TCP_HHOOK 1498 khelp_destroy_osd(tp->osd); 1499 #endif 1500 1501 CC_ALGO(tp) = NULL; 1502 inp->inp_ppcb = NULL; 1503 if (tp->t_timers->tt_draincnt == 0) { 1504 /* We own the last reference on tcpcb, let's free it. */ 1505 TCPSTATES_DEC(tp->t_state); 1506 if (tp->t_fb->tfb_tcp_fb_fini) 1507 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1508 refcount_release(&tp->t_fb->tfb_refcnt); 1509 tp->t_inpcb = NULL; 1510 uma_zfree(V_tcpcb_zone, tp); 1511 released = in_pcbrele_wlocked(inp); 1512 KASSERT(!released, ("%s: inp %p should not have been released " 1513 "here", __func__, inp)); 1514 } 1515 } 1516 1517 void 1518 tcp_timer_discard(void *ptp) 1519 { 1520 struct inpcb *inp; 1521 struct tcpcb *tp; 1522 1523 tp = (struct tcpcb *)ptp; 1524 CURVNET_SET(tp->t_vnet); 1525 INP_INFO_RLOCK(&V_tcbinfo); 1526 inp = tp->t_inpcb; 1527 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1528 __func__, tp)); 1529 INP_WLOCK(inp); 1530 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1531 ("%s: tcpcb has to be stopped here", __func__)); 1532 tp->t_timers->tt_draincnt--; 1533 if (tp->t_timers->tt_draincnt == 0) { 1534 /* We own the last reference on this tcpcb, let's free it. */ 1535 TCPSTATES_DEC(tp->t_state); 1536 if (tp->t_fb->tfb_tcp_fb_fini) 1537 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1538 refcount_release(&tp->t_fb->tfb_refcnt); 1539 tp->t_inpcb = NULL; 1540 uma_zfree(V_tcpcb_zone, tp); 1541 if (in_pcbrele_wlocked(inp)) { 1542 INP_INFO_RUNLOCK(&V_tcbinfo); 1543 CURVNET_RESTORE(); 1544 return; 1545 } 1546 } 1547 INP_WUNLOCK(inp); 1548 INP_INFO_RUNLOCK(&V_tcbinfo); 1549 CURVNET_RESTORE(); 1550 } 1551 1552 /* 1553 * Attempt to close a TCP control block, marking it as dropped, and freeing 1554 * the socket if we hold the only reference. 1555 */ 1556 struct tcpcb * 1557 tcp_close(struct tcpcb *tp) 1558 { 1559 struct inpcb *inp = tp->t_inpcb; 1560 struct socket *so; 1561 1562 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1563 INP_WLOCK_ASSERT(inp); 1564 1565 #ifdef TCP_OFFLOAD 1566 if (tp->t_state == TCPS_LISTEN) 1567 tcp_offload_listen_stop(tp); 1568 #endif 1569 #ifdef TCP_RFC7413 1570 /* 1571 * This releases the TFO pending counter resource for TFO listen 1572 * sockets as well as passively-created TFO sockets that transition 1573 * from SYN_RECEIVED to CLOSED. 1574 */ 1575 if (tp->t_tfo_pending) { 1576 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1577 tp->t_tfo_pending = NULL; 1578 } 1579 #endif 1580 in_pcbdrop(inp); 1581 TCPSTAT_INC(tcps_closed); 1582 if (tp->t_state != TCPS_CLOSED) 1583 tcp_state_change(tp, TCPS_CLOSED); 1584 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1585 so = inp->inp_socket; 1586 soisdisconnected(so); 1587 if (inp->inp_flags & INP_SOCKREF) { 1588 KASSERT(so->so_state & SS_PROTOREF, 1589 ("tcp_close: !SS_PROTOREF")); 1590 inp->inp_flags &= ~INP_SOCKREF; 1591 INP_WUNLOCK(inp); 1592 ACCEPT_LOCK(); 1593 SOCK_LOCK(so); 1594 so->so_state &= ~SS_PROTOREF; 1595 sofree(so); 1596 return (NULL); 1597 } 1598 return (tp); 1599 } 1600 1601 void 1602 tcp_drain(void) 1603 { 1604 VNET_ITERATOR_DECL(vnet_iter); 1605 1606 if (!do_tcpdrain) 1607 return; 1608 1609 VNET_LIST_RLOCK_NOSLEEP(); 1610 VNET_FOREACH(vnet_iter) { 1611 CURVNET_SET(vnet_iter); 1612 struct inpcb *inpb; 1613 struct tcpcb *tcpb; 1614 1615 /* 1616 * Walk the tcpbs, if existing, and flush the reassembly queue, 1617 * if there is one... 1618 * XXX: The "Net/3" implementation doesn't imply that the TCP 1619 * reassembly queue should be flushed, but in a situation 1620 * where we're really low on mbufs, this is potentially 1621 * useful. 1622 */ 1623 INP_INFO_WLOCK(&V_tcbinfo); 1624 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1625 if (inpb->inp_flags & INP_TIMEWAIT) 1626 continue; 1627 INP_WLOCK(inpb); 1628 if ((tcpb = intotcpcb(inpb)) != NULL) { 1629 tcp_reass_flush(tcpb); 1630 tcp_clean_sackreport(tcpb); 1631 #ifdef TCPPCAP 1632 if (tcp_pcap_aggressive_free) { 1633 /* Free the TCP PCAP queues. */ 1634 tcp_pcap_drain(&(tcpb->t_inpkts)); 1635 tcp_pcap_drain(&(tcpb->t_outpkts)); 1636 } 1637 #endif 1638 } 1639 INP_WUNLOCK(inpb); 1640 } 1641 INP_INFO_WUNLOCK(&V_tcbinfo); 1642 CURVNET_RESTORE(); 1643 } 1644 VNET_LIST_RUNLOCK_NOSLEEP(); 1645 } 1646 1647 /* 1648 * Notify a tcp user of an asynchronous error; 1649 * store error as soft error, but wake up user 1650 * (for now, won't do anything until can select for soft error). 1651 * 1652 * Do not wake up user since there currently is no mechanism for 1653 * reporting soft errors (yet - a kqueue filter may be added). 1654 */ 1655 static struct inpcb * 1656 tcp_notify(struct inpcb *inp, int error) 1657 { 1658 struct tcpcb *tp; 1659 1660 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1661 INP_WLOCK_ASSERT(inp); 1662 1663 if ((inp->inp_flags & INP_TIMEWAIT) || 1664 (inp->inp_flags & INP_DROPPED)) 1665 return (inp); 1666 1667 tp = intotcpcb(inp); 1668 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1669 1670 /* 1671 * Ignore some errors if we are hooked up. 1672 * If connection hasn't completed, has retransmitted several times, 1673 * and receives a second error, give up now. This is better 1674 * than waiting a long time to establish a connection that 1675 * can never complete. 1676 */ 1677 if (tp->t_state == TCPS_ESTABLISHED && 1678 (error == EHOSTUNREACH || error == ENETUNREACH || 1679 error == EHOSTDOWN)) { 1680 if (inp->inp_route.ro_rt) { 1681 RTFREE(inp->inp_route.ro_rt); 1682 inp->inp_route.ro_rt = (struct rtentry *)NULL; 1683 } 1684 return (inp); 1685 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1686 tp->t_softerror) { 1687 tp = tcp_drop(tp, error); 1688 if (tp != NULL) 1689 return (inp); 1690 else 1691 return (NULL); 1692 } else { 1693 tp->t_softerror = error; 1694 return (inp); 1695 } 1696 #if 0 1697 wakeup( &so->so_timeo); 1698 sorwakeup(so); 1699 sowwakeup(so); 1700 #endif 1701 } 1702 1703 static int 1704 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1705 { 1706 int error, i, m, n, pcb_count; 1707 struct inpcb *inp, **inp_list; 1708 inp_gen_t gencnt; 1709 struct xinpgen xig; 1710 1711 /* 1712 * The process of preparing the TCB list is too time-consuming and 1713 * resource-intensive to repeat twice on every request. 1714 */ 1715 if (req->oldptr == NULL) { 1716 n = V_tcbinfo.ipi_count + 1717 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1718 n += imax(n / 8, 10); 1719 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1720 return (0); 1721 } 1722 1723 if (req->newptr != NULL) 1724 return (EPERM); 1725 1726 /* 1727 * OK, now we're committed to doing something. 1728 */ 1729 INP_LIST_RLOCK(&V_tcbinfo); 1730 gencnt = V_tcbinfo.ipi_gencnt; 1731 n = V_tcbinfo.ipi_count; 1732 INP_LIST_RUNLOCK(&V_tcbinfo); 1733 1734 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1735 1736 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1737 + (n + m) * sizeof(struct xtcpcb)); 1738 if (error != 0) 1739 return (error); 1740 1741 xig.xig_len = sizeof xig; 1742 xig.xig_count = n + m; 1743 xig.xig_gen = gencnt; 1744 xig.xig_sogen = so_gencnt; 1745 error = SYSCTL_OUT(req, &xig, sizeof xig); 1746 if (error) 1747 return (error); 1748 1749 error = syncache_pcblist(req, m, &pcb_count); 1750 if (error) 1751 return (error); 1752 1753 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1754 1755 INP_INFO_WLOCK(&V_tcbinfo); 1756 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1757 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1758 INP_WLOCK(inp); 1759 if (inp->inp_gencnt <= gencnt) { 1760 /* 1761 * XXX: This use of cr_cansee(), introduced with 1762 * TCP state changes, is not quite right, but for 1763 * now, better than nothing. 1764 */ 1765 if (inp->inp_flags & INP_TIMEWAIT) { 1766 if (intotw(inp) != NULL) 1767 error = cr_cansee(req->td->td_ucred, 1768 intotw(inp)->tw_cred); 1769 else 1770 error = EINVAL; /* Skip this inp. */ 1771 } else 1772 error = cr_canseeinpcb(req->td->td_ucred, inp); 1773 if (error == 0) { 1774 in_pcbref(inp); 1775 inp_list[i++] = inp; 1776 } 1777 } 1778 INP_WUNLOCK(inp); 1779 } 1780 INP_INFO_WUNLOCK(&V_tcbinfo); 1781 n = i; 1782 1783 error = 0; 1784 for (i = 0; i < n; i++) { 1785 inp = inp_list[i]; 1786 INP_RLOCK(inp); 1787 if (inp->inp_gencnt <= gencnt) { 1788 struct xtcpcb xt; 1789 void *inp_ppcb; 1790 1791 bzero(&xt, sizeof(xt)); 1792 xt.xt_len = sizeof xt; 1793 /* XXX should avoid extra copy */ 1794 bcopy(inp, &xt.xt_inp, sizeof *inp); 1795 inp_ppcb = inp->inp_ppcb; 1796 if (inp_ppcb == NULL) 1797 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1798 else if (inp->inp_flags & INP_TIMEWAIT) { 1799 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1800 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1801 } else { 1802 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1803 if (xt.xt_tp.t_timers) 1804 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1805 } 1806 if (inp->inp_socket != NULL) 1807 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1808 else { 1809 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1810 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1811 } 1812 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1813 INP_RUNLOCK(inp); 1814 error = SYSCTL_OUT(req, &xt, sizeof xt); 1815 } else 1816 INP_RUNLOCK(inp); 1817 } 1818 INP_INFO_RLOCK(&V_tcbinfo); 1819 for (i = 0; i < n; i++) { 1820 inp = inp_list[i]; 1821 INP_RLOCK(inp); 1822 if (!in_pcbrele_rlocked(inp)) 1823 INP_RUNLOCK(inp); 1824 } 1825 INP_INFO_RUNLOCK(&V_tcbinfo); 1826 1827 if (!error) { 1828 /* 1829 * Give the user an updated idea of our state. 1830 * If the generation differs from what we told 1831 * her before, she knows that something happened 1832 * while we were processing this request, and it 1833 * might be necessary to retry. 1834 */ 1835 INP_LIST_RLOCK(&V_tcbinfo); 1836 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1837 xig.xig_sogen = so_gencnt; 1838 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1839 INP_LIST_RUNLOCK(&V_tcbinfo); 1840 error = SYSCTL_OUT(req, &xig, sizeof xig); 1841 } 1842 free(inp_list, M_TEMP); 1843 return (error); 1844 } 1845 1846 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1847 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1848 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1849 1850 #ifdef INET 1851 static int 1852 tcp_getcred(SYSCTL_HANDLER_ARGS) 1853 { 1854 struct xucred xuc; 1855 struct sockaddr_in addrs[2]; 1856 struct inpcb *inp; 1857 int error; 1858 1859 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1860 if (error) 1861 return (error); 1862 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1863 if (error) 1864 return (error); 1865 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1866 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1867 if (inp != NULL) { 1868 if (inp->inp_socket == NULL) 1869 error = ENOENT; 1870 if (error == 0) 1871 error = cr_canseeinpcb(req->td->td_ucred, inp); 1872 if (error == 0) 1873 cru2x(inp->inp_cred, &xuc); 1874 INP_RUNLOCK(inp); 1875 } else 1876 error = ENOENT; 1877 if (error == 0) 1878 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1879 return (error); 1880 } 1881 1882 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1883 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1884 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1885 #endif /* INET */ 1886 1887 #ifdef INET6 1888 static int 1889 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1890 { 1891 struct xucred xuc; 1892 struct sockaddr_in6 addrs[2]; 1893 struct inpcb *inp; 1894 int error; 1895 #ifdef INET 1896 int mapped = 0; 1897 #endif 1898 1899 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1900 if (error) 1901 return (error); 1902 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1903 if (error) 1904 return (error); 1905 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1906 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1907 return (error); 1908 } 1909 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1910 #ifdef INET 1911 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1912 mapped = 1; 1913 else 1914 #endif 1915 return (EINVAL); 1916 } 1917 1918 #ifdef INET 1919 if (mapped == 1) 1920 inp = in_pcblookup(&V_tcbinfo, 1921 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1922 addrs[1].sin6_port, 1923 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1924 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1925 else 1926 #endif 1927 inp = in6_pcblookup(&V_tcbinfo, 1928 &addrs[1].sin6_addr, addrs[1].sin6_port, 1929 &addrs[0].sin6_addr, addrs[0].sin6_port, 1930 INPLOOKUP_RLOCKPCB, NULL); 1931 if (inp != NULL) { 1932 if (inp->inp_socket == NULL) 1933 error = ENOENT; 1934 if (error == 0) 1935 error = cr_canseeinpcb(req->td->td_ucred, inp); 1936 if (error == 0) 1937 cru2x(inp->inp_cred, &xuc); 1938 INP_RUNLOCK(inp); 1939 } else 1940 error = ENOENT; 1941 if (error == 0) 1942 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1943 return (error); 1944 } 1945 1946 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1947 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1948 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1949 #endif /* INET6 */ 1950 1951 1952 #ifdef INET 1953 void 1954 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1955 { 1956 struct ip *ip = vip; 1957 struct tcphdr *th; 1958 struct in_addr faddr; 1959 struct inpcb *inp; 1960 struct tcpcb *tp; 1961 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1962 struct icmp *icp; 1963 struct in_conninfo inc; 1964 tcp_seq icmp_tcp_seq; 1965 int mtu; 1966 1967 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1968 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1969 return; 1970 1971 if (cmd == PRC_MSGSIZE) 1972 notify = tcp_mtudisc_notify; 1973 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1974 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 1975 cmd == PRC_TIMXCEED_INTRANS) && ip) 1976 notify = tcp_drop_syn_sent; 1977 1978 /* 1979 * Hostdead is ugly because it goes linearly through all PCBs. 1980 * XXX: We never get this from ICMP, otherwise it makes an 1981 * excellent DoS attack on machines with many connections. 1982 */ 1983 else if (cmd == PRC_HOSTDEAD) 1984 ip = NULL; 1985 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1986 return; 1987 1988 if (ip == NULL) { 1989 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1990 return; 1991 } 1992 1993 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1994 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1995 INP_INFO_RLOCK(&V_tcbinfo); 1996 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1997 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1998 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 1999 /* signal EHOSTDOWN, as it flushes the cached route */ 2000 inp = (*notify)(inp, EHOSTDOWN); 2001 if (inp != NULL) 2002 INP_WUNLOCK(inp); 2003 } else if (inp != NULL) { 2004 if (!(inp->inp_flags & INP_TIMEWAIT) && 2005 !(inp->inp_flags & INP_DROPPED) && 2006 !(inp->inp_socket == NULL)) { 2007 icmp_tcp_seq = ntohl(th->th_seq); 2008 tp = intotcpcb(inp); 2009 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 2010 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 2011 if (cmd == PRC_MSGSIZE) { 2012 /* 2013 * MTU discovery: 2014 * If we got a needfrag set the MTU 2015 * in the route to the suggested new 2016 * value (if given) and then notify. 2017 */ 2018 mtu = ntohs(icp->icmp_nextmtu); 2019 /* 2020 * If no alternative MTU was 2021 * proposed, try the next smaller 2022 * one. 2023 */ 2024 if (!mtu) 2025 mtu = ip_next_mtu( 2026 ntohs(ip->ip_len), 1); 2027 if (mtu < V_tcp_minmss + 2028 sizeof(struct tcpiphdr)) 2029 mtu = V_tcp_minmss + 2030 sizeof(struct tcpiphdr); 2031 /* 2032 * Only process the offered MTU if it 2033 * is smaller than the current one. 2034 */ 2035 if (mtu < tp->t_maxseg + 2036 sizeof(struct tcpiphdr)) { 2037 bzero(&inc, sizeof(inc)); 2038 inc.inc_faddr = faddr; 2039 inc.inc_fibnum = 2040 inp->inp_inc.inc_fibnum; 2041 tcp_hc_updatemtu(&inc, mtu); 2042 tcp_mtudisc(inp, mtu); 2043 } 2044 } else 2045 inp = (*notify)(inp, 2046 inetctlerrmap[cmd]); 2047 } 2048 } 2049 if (inp != NULL) 2050 INP_WUNLOCK(inp); 2051 } else { 2052 bzero(&inc, sizeof(inc)); 2053 inc.inc_fport = th->th_dport; 2054 inc.inc_lport = th->th_sport; 2055 inc.inc_faddr = faddr; 2056 inc.inc_laddr = ip->ip_src; 2057 syncache_unreach(&inc, th); 2058 } 2059 INP_INFO_RUNLOCK(&V_tcbinfo); 2060 } 2061 #endif /* INET */ 2062 2063 #ifdef INET6 2064 void 2065 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2066 { 2067 struct in6_addr *dst; 2068 struct tcphdr *th; 2069 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2070 struct ip6_hdr *ip6; 2071 struct mbuf *m; 2072 struct inpcb *inp; 2073 struct tcpcb *tp; 2074 struct icmp6_hdr *icmp6; 2075 struct ip6ctlparam *ip6cp = NULL; 2076 const struct sockaddr_in6 *sa6_src = NULL; 2077 struct in_conninfo inc; 2078 tcp_seq icmp_tcp_seq; 2079 unsigned int mtu; 2080 unsigned int off; 2081 2082 2083 if (sa->sa_family != AF_INET6 || 2084 sa->sa_len != sizeof(struct sockaddr_in6)) 2085 return; 2086 2087 /* if the parameter is from icmp6, decode it. */ 2088 if (d != NULL) { 2089 ip6cp = (struct ip6ctlparam *)d; 2090 icmp6 = ip6cp->ip6c_icmp6; 2091 m = ip6cp->ip6c_m; 2092 ip6 = ip6cp->ip6c_ip6; 2093 off = ip6cp->ip6c_off; 2094 sa6_src = ip6cp->ip6c_src; 2095 dst = ip6cp->ip6c_finaldst; 2096 } else { 2097 m = NULL; 2098 ip6 = NULL; 2099 off = 0; /* fool gcc */ 2100 sa6_src = &sa6_any; 2101 dst = NULL; 2102 } 2103 2104 if (cmd == PRC_MSGSIZE) 2105 notify = tcp_mtudisc_notify; 2106 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2107 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2108 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2109 notify = tcp_drop_syn_sent; 2110 2111 /* 2112 * Hostdead is ugly because it goes linearly through all PCBs. 2113 * XXX: We never get this from ICMP, otherwise it makes an 2114 * excellent DoS attack on machines with many connections. 2115 */ 2116 else if (cmd == PRC_HOSTDEAD) 2117 ip6 = NULL; 2118 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2119 return; 2120 2121 if (ip6 == NULL) { 2122 in6_pcbnotify(&V_tcbinfo, sa, 0, 2123 (const struct sockaddr *)sa6_src, 2124 0, cmd, NULL, notify); 2125 return; 2126 } 2127 2128 /* Check if we can safely get the ports from the tcp hdr */ 2129 if (m == NULL || 2130 (m->m_pkthdr.len < 2131 (int32_t) (off + offsetof(struct tcphdr, th_seq)))) { 2132 return; 2133 } 2134 2135 th = (struct tcphdr *) mtodo(ip6cp->ip6c_m, ip6cp->ip6c_off); 2136 INP_INFO_RLOCK(&V_tcbinfo); 2137 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, th->th_dport, 2138 &ip6->ip6_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2139 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2140 /* signal EHOSTDOWN, as it flushes the cached route */ 2141 inp = (*notify)(inp, EHOSTDOWN); 2142 if (inp != NULL) 2143 INP_WUNLOCK(inp); 2144 } else if (inp != NULL) { 2145 if (!(inp->inp_flags & INP_TIMEWAIT) && 2146 !(inp->inp_flags & INP_DROPPED) && 2147 !(inp->inp_socket == NULL)) { 2148 icmp_tcp_seq = ntohl(th->th_seq); 2149 tp = intotcpcb(inp); 2150 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 2151 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 2152 if (cmd == PRC_MSGSIZE) { 2153 /* 2154 * MTU discovery: 2155 * If we got a needfrag set the MTU 2156 * in the route to the suggested new 2157 * value (if given) and then notify. 2158 */ 2159 mtu = ntohl(icmp6->icmp6_mtu); 2160 /* 2161 * If no alternative MTU was 2162 * proposed, or the proposed 2163 * MTU was too small, set to 2164 * the min. 2165 */ 2166 if (mtu < IPV6_MMTU) 2167 mtu = IPV6_MMTU - 8; 2168 2169 2170 bzero(&inc, sizeof(inc)); 2171 inc.inc_fibnum = M_GETFIB(m); 2172 inc.inc_flags |= INC_ISIPV6; 2173 inc.inc6_faddr = *dst; 2174 if (in6_setscope(&inc.inc6_faddr, 2175 m->m_pkthdr.rcvif, NULL)) 2176 goto unlock_inp; 2177 2178 /* 2179 * Only process the offered MTU if it 2180 * is smaller than the current one. 2181 */ 2182 if (mtu < tp->t_maxseg + 2183 (sizeof (*th) + sizeof (*ip6))) { 2184 tcp_hc_updatemtu(&inc, mtu); 2185 tcp_mtudisc(inp, mtu); 2186 ICMP6STAT_INC(icp6s_pmtuchg); 2187 } 2188 } else 2189 inp = (*notify)(inp, 2190 inet6ctlerrmap[cmd]); 2191 } 2192 } 2193 unlock_inp: 2194 if (inp != NULL) 2195 INP_WUNLOCK(inp); 2196 } else { 2197 bzero(&inc, sizeof(inc)); 2198 inc.inc_fibnum = M_GETFIB(m); 2199 inc.inc_flags |= INC_ISIPV6; 2200 inc.inc_fport = th->th_dport; 2201 inc.inc_lport = th->th_sport; 2202 inc.inc6_faddr = *dst; 2203 inc.inc6_laddr = ip6->ip6_src; 2204 syncache_unreach(&inc, th); 2205 } 2206 INP_INFO_RUNLOCK(&V_tcbinfo); 2207 } 2208 #endif /* INET6 */ 2209 2210 2211 /* 2212 * Following is where TCP initial sequence number generation occurs. 2213 * 2214 * There are two places where we must use initial sequence numbers: 2215 * 1. In SYN-ACK packets. 2216 * 2. In SYN packets. 2217 * 2218 * All ISNs for SYN-ACK packets are generated by the syncache. See 2219 * tcp_syncache.c for details. 2220 * 2221 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2222 * depends on this property. In addition, these ISNs should be 2223 * unguessable so as to prevent connection hijacking. To satisfy 2224 * the requirements of this situation, the algorithm outlined in 2225 * RFC 1948 is used, with only small modifications. 2226 * 2227 * Implementation details: 2228 * 2229 * Time is based off the system timer, and is corrected so that it 2230 * increases by one megabyte per second. This allows for proper 2231 * recycling on high speed LANs while still leaving over an hour 2232 * before rollover. 2233 * 2234 * As reading the *exact* system time is too expensive to be done 2235 * whenever setting up a TCP connection, we increment the time 2236 * offset in two ways. First, a small random positive increment 2237 * is added to isn_offset for each connection that is set up. 2238 * Second, the function tcp_isn_tick fires once per clock tick 2239 * and increments isn_offset as necessary so that sequence numbers 2240 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2241 * random positive increments serve only to ensure that the same 2242 * exact sequence number is never sent out twice (as could otherwise 2243 * happen when a port is recycled in less than the system tick 2244 * interval.) 2245 * 2246 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2247 * between seeding of isn_secret. This is normally set to zero, 2248 * as reseeding should not be necessary. 2249 * 2250 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2251 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2252 * general, this means holding an exclusive (write) lock. 2253 */ 2254 2255 #define ISN_BYTES_PER_SECOND 1048576 2256 #define ISN_STATIC_INCREMENT 4096 2257 #define ISN_RANDOM_INCREMENT (4096 - 1) 2258 2259 static VNET_DEFINE(u_char, isn_secret[32]); 2260 static VNET_DEFINE(int, isn_last); 2261 static VNET_DEFINE(int, isn_last_reseed); 2262 static VNET_DEFINE(u_int32_t, isn_offset); 2263 static VNET_DEFINE(u_int32_t, isn_offset_old); 2264 2265 #define V_isn_secret VNET(isn_secret) 2266 #define V_isn_last VNET(isn_last) 2267 #define V_isn_last_reseed VNET(isn_last_reseed) 2268 #define V_isn_offset VNET(isn_offset) 2269 #define V_isn_offset_old VNET(isn_offset_old) 2270 2271 tcp_seq 2272 tcp_new_isn(struct tcpcb *tp) 2273 { 2274 MD5_CTX isn_ctx; 2275 u_int32_t md5_buffer[4]; 2276 tcp_seq new_isn; 2277 u_int32_t projected_offset; 2278 2279 INP_WLOCK_ASSERT(tp->t_inpcb); 2280 2281 ISN_LOCK(); 2282 /* Seed if this is the first use, reseed if requested. */ 2283 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2284 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2285 < (u_int)ticks))) { 2286 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2287 V_isn_last_reseed = ticks; 2288 } 2289 2290 /* Compute the md5 hash and return the ISN. */ 2291 MD5Init(&isn_ctx); 2292 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2293 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2294 #ifdef INET6 2295 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2296 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2297 sizeof(struct in6_addr)); 2298 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2299 sizeof(struct in6_addr)); 2300 } else 2301 #endif 2302 { 2303 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2304 sizeof(struct in_addr)); 2305 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2306 sizeof(struct in_addr)); 2307 } 2308 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2309 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2310 new_isn = (tcp_seq) md5_buffer[0]; 2311 V_isn_offset += ISN_STATIC_INCREMENT + 2312 (arc4random() & ISN_RANDOM_INCREMENT); 2313 if (ticks != V_isn_last) { 2314 projected_offset = V_isn_offset_old + 2315 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2316 if (SEQ_GT(projected_offset, V_isn_offset)) 2317 V_isn_offset = projected_offset; 2318 V_isn_offset_old = V_isn_offset; 2319 V_isn_last = ticks; 2320 } 2321 new_isn += V_isn_offset; 2322 ISN_UNLOCK(); 2323 return (new_isn); 2324 } 2325 2326 /* 2327 * When a specific ICMP unreachable message is received and the 2328 * connection state is SYN-SENT, drop the connection. This behavior 2329 * is controlled by the icmp_may_rst sysctl. 2330 */ 2331 struct inpcb * 2332 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2333 { 2334 struct tcpcb *tp; 2335 2336 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2337 INP_WLOCK_ASSERT(inp); 2338 2339 if ((inp->inp_flags & INP_TIMEWAIT) || 2340 (inp->inp_flags & INP_DROPPED)) 2341 return (inp); 2342 2343 tp = intotcpcb(inp); 2344 if (tp->t_state != TCPS_SYN_SENT) 2345 return (inp); 2346 2347 tp = tcp_drop(tp, errno); 2348 if (tp != NULL) 2349 return (inp); 2350 else 2351 return (NULL); 2352 } 2353 2354 /* 2355 * When `need fragmentation' ICMP is received, update our idea of the MSS 2356 * based on the new value. Also nudge TCP to send something, since we 2357 * know the packet we just sent was dropped. 2358 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2359 */ 2360 static struct inpcb * 2361 tcp_mtudisc_notify(struct inpcb *inp, int error) 2362 { 2363 2364 tcp_mtudisc(inp, -1); 2365 return (inp); 2366 } 2367 2368 static void 2369 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2370 { 2371 struct tcpcb *tp; 2372 struct socket *so; 2373 2374 INP_WLOCK_ASSERT(inp); 2375 if ((inp->inp_flags & INP_TIMEWAIT) || 2376 (inp->inp_flags & INP_DROPPED)) 2377 return; 2378 2379 tp = intotcpcb(inp); 2380 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2381 2382 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2383 2384 so = inp->inp_socket; 2385 SOCKBUF_LOCK(&so->so_snd); 2386 /* If the mss is larger than the socket buffer, decrease the mss. */ 2387 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2388 tp->t_maxseg = so->so_snd.sb_hiwat; 2389 SOCKBUF_UNLOCK(&so->so_snd); 2390 2391 TCPSTAT_INC(tcps_mturesent); 2392 tp->t_rtttime = 0; 2393 tp->snd_nxt = tp->snd_una; 2394 tcp_free_sackholes(tp); 2395 tp->snd_recover = tp->snd_max; 2396 if (tp->t_flags & TF_SACK_PERMIT) 2397 EXIT_FASTRECOVERY(tp->t_flags); 2398 tp->t_fb->tfb_tcp_output(tp); 2399 } 2400 2401 #ifdef INET 2402 /* 2403 * Look-up the routing entry to the peer of this inpcb. If no route 2404 * is found and it cannot be allocated, then return 0. This routine 2405 * is called by TCP routines that access the rmx structure and by 2406 * tcp_mss_update to get the peer/interface MTU. 2407 */ 2408 uint32_t 2409 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2410 { 2411 struct nhop4_extended nh4; 2412 struct ifnet *ifp; 2413 uint32_t maxmtu = 0; 2414 2415 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2416 2417 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2418 2419 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2420 NHR_REF, 0, &nh4) != 0) 2421 return (0); 2422 2423 ifp = nh4.nh_ifp; 2424 maxmtu = nh4.nh_mtu; 2425 2426 /* Report additional interface capabilities. */ 2427 if (cap != NULL) { 2428 if (ifp->if_capenable & IFCAP_TSO4 && 2429 ifp->if_hwassist & CSUM_TSO) { 2430 cap->ifcap |= CSUM_TSO; 2431 cap->tsomax = ifp->if_hw_tsomax; 2432 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2433 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2434 } 2435 } 2436 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2437 } 2438 return (maxmtu); 2439 } 2440 #endif /* INET */ 2441 2442 #ifdef INET6 2443 uint32_t 2444 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2445 { 2446 struct nhop6_extended nh6; 2447 struct in6_addr dst6; 2448 uint32_t scopeid; 2449 struct ifnet *ifp; 2450 uint32_t maxmtu = 0; 2451 2452 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2453 2454 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2455 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2456 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2457 0, &nh6) != 0) 2458 return (0); 2459 2460 ifp = nh6.nh_ifp; 2461 maxmtu = nh6.nh_mtu; 2462 2463 /* Report additional interface capabilities. */ 2464 if (cap != NULL) { 2465 if (ifp->if_capenable & IFCAP_TSO6 && 2466 ifp->if_hwassist & CSUM_TSO) { 2467 cap->ifcap |= CSUM_TSO; 2468 cap->tsomax = ifp->if_hw_tsomax; 2469 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2470 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2471 } 2472 } 2473 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2474 } 2475 2476 return (maxmtu); 2477 } 2478 #endif /* INET6 */ 2479 2480 /* 2481 * Calculate effective SMSS per RFC5681 definition for a given TCP 2482 * connection at its current state, taking into account SACK and etc. 2483 */ 2484 u_int 2485 tcp_maxseg(const struct tcpcb *tp) 2486 { 2487 u_int optlen; 2488 2489 if (tp->t_flags & TF_NOOPT) 2490 return (tp->t_maxseg); 2491 2492 /* 2493 * Here we have a simplified code from tcp_addoptions(), 2494 * without a proper loop, and having most of paddings hardcoded. 2495 * We might make mistakes with padding here in some edge cases, 2496 * but this is harmless, since result of tcp_maxseg() is used 2497 * only in cwnd and ssthresh estimations. 2498 */ 2499 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2500 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2501 if (tp->t_flags & TF_RCVD_TSTMP) 2502 optlen = TCPOLEN_TSTAMP_APPA; 2503 else 2504 optlen = 0; 2505 #ifdef TCP_SIGNATURE 2506 if (tp->t_flags & TF_SIGNATURE) 2507 optlen += PAD(TCPOLEN_SIGNATURE); 2508 #endif 2509 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2510 optlen += TCPOLEN_SACKHDR; 2511 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2512 optlen = PAD(optlen); 2513 } 2514 } else { 2515 if (tp->t_flags & TF_REQ_TSTMP) 2516 optlen = TCPOLEN_TSTAMP_APPA; 2517 else 2518 optlen = PAD(TCPOLEN_MAXSEG); 2519 if (tp->t_flags & TF_REQ_SCALE) 2520 optlen += PAD(TCPOLEN_WINDOW); 2521 #ifdef TCP_SIGNATURE 2522 if (tp->t_flags & TF_SIGNATURE) 2523 optlen += PAD(TCPOLEN_SIGNATURE); 2524 #endif 2525 if (tp->t_flags & TF_SACK_PERMIT) 2526 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2527 } 2528 #undef PAD 2529 optlen = min(optlen, TCP_MAXOLEN); 2530 return (tp->t_maxseg - optlen); 2531 } 2532 2533 #ifdef IPSEC 2534 /* compute ESP/AH header size for TCP, including outer IP header. */ 2535 size_t 2536 ipsec_hdrsiz_tcp(struct tcpcb *tp) 2537 { 2538 struct inpcb *inp; 2539 struct mbuf *m; 2540 size_t hdrsiz; 2541 struct ip *ip; 2542 #ifdef INET6 2543 struct ip6_hdr *ip6; 2544 #endif 2545 struct tcphdr *th; 2546 2547 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2548 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2549 return (0); 2550 m = m_gethdr(M_NOWAIT, MT_DATA); 2551 if (!m) 2552 return (0); 2553 2554 #ifdef INET6 2555 if ((inp->inp_vflag & INP_IPV6) != 0) { 2556 ip6 = mtod(m, struct ip6_hdr *); 2557 th = (struct tcphdr *)(ip6 + 1); 2558 m->m_pkthdr.len = m->m_len = 2559 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2560 tcpip_fillheaders(inp, ip6, th); 2561 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2562 } else 2563 #endif /* INET6 */ 2564 { 2565 ip = mtod(m, struct ip *); 2566 th = (struct tcphdr *)(ip + 1); 2567 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2568 tcpip_fillheaders(inp, ip, th); 2569 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2570 } 2571 2572 m_free(m); 2573 return (hdrsiz); 2574 } 2575 #endif /* IPSEC */ 2576 2577 #ifdef TCP_SIGNATURE 2578 /* 2579 * Callback function invoked by m_apply() to digest TCP segment data 2580 * contained within an mbuf chain. 2581 */ 2582 static int 2583 tcp_signature_apply(void *fstate, void *data, u_int len) 2584 { 2585 2586 MD5Update(fstate, (u_char *)data, len); 2587 return (0); 2588 } 2589 2590 /* 2591 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2592 * search with the destination IP address, and a 'magic SPI' to be 2593 * determined by the application. This is hardcoded elsewhere to 1179 2594 */ 2595 struct secasvar * 2596 tcp_get_sav(struct mbuf *m, u_int direction) 2597 { 2598 union sockaddr_union dst; 2599 struct secasvar *sav; 2600 struct ip *ip; 2601 #ifdef INET6 2602 struct ip6_hdr *ip6; 2603 char ip6buf[INET6_ADDRSTRLEN]; 2604 #endif 2605 2606 /* Extract the destination from the IP header in the mbuf. */ 2607 bzero(&dst, sizeof(union sockaddr_union)); 2608 ip = mtod(m, struct ip *); 2609 #ifdef INET6 2610 ip6 = NULL; /* Make the compiler happy. */ 2611 #endif 2612 switch (ip->ip_v) { 2613 #ifdef INET 2614 case IPVERSION: 2615 dst.sa.sa_len = sizeof(struct sockaddr_in); 2616 dst.sa.sa_family = AF_INET; 2617 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2618 ip->ip_src : ip->ip_dst; 2619 break; 2620 #endif 2621 #ifdef INET6 2622 case (IPV6_VERSION >> 4): 2623 ip6 = mtod(m, struct ip6_hdr *); 2624 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2625 dst.sa.sa_family = AF_INET6; 2626 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2627 ip6->ip6_src : ip6->ip6_dst; 2628 break; 2629 #endif 2630 default: 2631 return (NULL); 2632 /* NOTREACHED */ 2633 break; 2634 } 2635 2636 /* Look up an SADB entry which matches the address of the peer. */ 2637 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2638 if (sav == NULL) { 2639 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2640 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2641 #ifdef INET6 2642 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2643 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2644 #endif 2645 "(unsupported)")); 2646 } 2647 2648 return (sav); 2649 } 2650 2651 /* 2652 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2653 * 2654 * Parameters: 2655 * m pointer to head of mbuf chain 2656 * len length of TCP segment data, excluding options 2657 * optlen length of TCP segment options 2658 * buf pointer to storage for computed MD5 digest 2659 * sav pointer to security assosiation 2660 * 2661 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2662 * When called from tcp_input(), we can be sure that th_sum has been 2663 * zeroed out and verified already. 2664 * 2665 * Releases reference to SADB key before return. 2666 * 2667 * Return 0 if successful, otherwise return -1. 2668 * 2669 */ 2670 int 2671 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2672 u_char *buf, struct secasvar *sav) 2673 { 2674 #ifdef INET 2675 struct ippseudo ippseudo; 2676 #endif 2677 MD5_CTX ctx; 2678 int doff; 2679 struct ip *ip; 2680 #ifdef INET 2681 struct ipovly *ipovly; 2682 #endif 2683 struct tcphdr *th; 2684 #ifdef INET6 2685 struct ip6_hdr *ip6; 2686 struct in6_addr in6; 2687 uint32_t plen; 2688 uint16_t nhdr; 2689 #endif 2690 u_short savecsum; 2691 2692 KASSERT(m != NULL, ("NULL mbuf chain")); 2693 KASSERT(buf != NULL, ("NULL signature pointer")); 2694 2695 /* Extract the destination from the IP header in the mbuf. */ 2696 ip = mtod(m, struct ip *); 2697 #ifdef INET6 2698 ip6 = NULL; /* Make the compiler happy. */ 2699 #endif 2700 2701 MD5Init(&ctx); 2702 /* 2703 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2704 * 2705 * XXX The ippseudo header MUST be digested in network byte order, 2706 * or else we'll fail the regression test. Assume all fields we've 2707 * been doing arithmetic on have been in host byte order. 2708 * XXX One cannot depend on ipovly->ih_len here. When called from 2709 * tcp_output(), the underlying ip_len member has not yet been set. 2710 */ 2711 switch (ip->ip_v) { 2712 #ifdef INET 2713 case IPVERSION: 2714 ipovly = (struct ipovly *)ip; 2715 ippseudo.ippseudo_src = ipovly->ih_src; 2716 ippseudo.ippseudo_dst = ipovly->ih_dst; 2717 ippseudo.ippseudo_pad = 0; 2718 ippseudo.ippseudo_p = IPPROTO_TCP; 2719 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2720 optlen); 2721 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2722 2723 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2724 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2725 break; 2726 #endif 2727 #ifdef INET6 2728 /* 2729 * RFC 2385, 2.0 Proposal 2730 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2731 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2732 * extended next header value (to form 32 bits), and 32-bit segment 2733 * length. 2734 * Note: Upper-Layer Packet Length comes before Next Header. 2735 */ 2736 case (IPV6_VERSION >> 4): 2737 ip6 = mtod(m, struct ip6_hdr *); 2738 in6 = ip6->ip6_src; 2739 in6_clearscope(&in6); 2740 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2741 in6 = ip6->ip6_dst; 2742 in6_clearscope(&in6); 2743 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2744 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2745 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2746 nhdr = 0; 2747 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2748 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2749 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2750 nhdr = IPPROTO_TCP; 2751 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2752 2753 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2754 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2755 break; 2756 #endif 2757 default: 2758 KEY_FREESAV(&sav); 2759 return (-1); 2760 /* NOTREACHED */ 2761 break; 2762 } 2763 2764 2765 /* 2766 * Step 2: Update MD5 hash with TCP header, excluding options. 2767 * The TCP checksum must be set to zero. 2768 */ 2769 savecsum = th->th_sum; 2770 th->th_sum = 0; 2771 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2772 th->th_sum = savecsum; 2773 2774 /* 2775 * Step 3: Update MD5 hash with TCP segment data. 2776 * Use m_apply() to avoid an early m_pullup(). 2777 */ 2778 if (len > 0) 2779 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2780 2781 /* 2782 * Step 4: Update MD5 hash with shared secret. 2783 */ 2784 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2785 MD5Final(buf, &ctx); 2786 2787 key_sa_recordxfer(sav, m); 2788 KEY_FREESAV(&sav); 2789 return (0); 2790 } 2791 2792 /* 2793 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2794 * 2795 * Return 0 if successful, otherwise return -1. 2796 */ 2797 int 2798 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2799 u_char *buf, u_int direction) 2800 { 2801 struct secasvar *sav; 2802 2803 if ((sav = tcp_get_sav(m, direction)) == NULL) 2804 return (-1); 2805 2806 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2807 } 2808 2809 /* 2810 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2811 * 2812 * Parameters: 2813 * m pointer to head of mbuf chain 2814 * len length of TCP segment data, excluding options 2815 * optlen length of TCP segment options 2816 * buf pointer to storage for computed MD5 digest 2817 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2818 * 2819 * Return 1 if successful, otherwise return 0. 2820 */ 2821 int 2822 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2823 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2824 { 2825 char tmpdigest[TCP_SIGLEN]; 2826 2827 if (tcp_sig_checksigs == 0) 2828 return (1); 2829 if ((tcpbflag & TF_SIGNATURE) == 0) { 2830 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2831 2832 /* 2833 * If this socket is not expecting signature but 2834 * the segment contains signature just fail. 2835 */ 2836 TCPSTAT_INC(tcps_sig_err_sigopt); 2837 TCPSTAT_INC(tcps_sig_rcvbadsig); 2838 return (0); 2839 } 2840 2841 /* Signature is not expected, and not present in segment. */ 2842 return (1); 2843 } 2844 2845 /* 2846 * If this socket is expecting signature but the segment does not 2847 * contain any just fail. 2848 */ 2849 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2850 TCPSTAT_INC(tcps_sig_err_nosigopt); 2851 TCPSTAT_INC(tcps_sig_rcvbadsig); 2852 return (0); 2853 } 2854 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2855 IPSEC_DIR_INBOUND) == -1) { 2856 TCPSTAT_INC(tcps_sig_err_buildsig); 2857 TCPSTAT_INC(tcps_sig_rcvbadsig); 2858 return (0); 2859 } 2860 2861 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2862 TCPSTAT_INC(tcps_sig_rcvbadsig); 2863 return (0); 2864 } 2865 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2866 return (1); 2867 } 2868 #endif /* TCP_SIGNATURE */ 2869 2870 static int 2871 sysctl_drop(SYSCTL_HANDLER_ARGS) 2872 { 2873 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2874 struct sockaddr_storage addrs[2]; 2875 struct inpcb *inp; 2876 struct tcpcb *tp; 2877 struct tcptw *tw; 2878 struct sockaddr_in *fin, *lin; 2879 #ifdef INET6 2880 struct sockaddr_in6 *fin6, *lin6; 2881 #endif 2882 int error; 2883 2884 inp = NULL; 2885 fin = lin = NULL; 2886 #ifdef INET6 2887 fin6 = lin6 = NULL; 2888 #endif 2889 error = 0; 2890 2891 if (req->oldptr != NULL || req->oldlen != 0) 2892 return (EINVAL); 2893 if (req->newptr == NULL) 2894 return (EPERM); 2895 if (req->newlen < sizeof(addrs)) 2896 return (ENOMEM); 2897 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2898 if (error) 2899 return (error); 2900 2901 switch (addrs[0].ss_family) { 2902 #ifdef INET6 2903 case AF_INET6: 2904 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2905 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2906 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2907 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2908 return (EINVAL); 2909 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2910 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2911 return (EINVAL); 2912 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2913 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2914 fin = (struct sockaddr_in *)&addrs[0]; 2915 lin = (struct sockaddr_in *)&addrs[1]; 2916 break; 2917 } 2918 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2919 if (error) 2920 return (error); 2921 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2922 if (error) 2923 return (error); 2924 break; 2925 #endif 2926 #ifdef INET 2927 case AF_INET: 2928 fin = (struct sockaddr_in *)&addrs[0]; 2929 lin = (struct sockaddr_in *)&addrs[1]; 2930 if (fin->sin_len != sizeof(struct sockaddr_in) || 2931 lin->sin_len != sizeof(struct sockaddr_in)) 2932 return (EINVAL); 2933 break; 2934 #endif 2935 default: 2936 return (EINVAL); 2937 } 2938 INP_INFO_RLOCK(&V_tcbinfo); 2939 switch (addrs[0].ss_family) { 2940 #ifdef INET6 2941 case AF_INET6: 2942 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2943 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2944 INPLOOKUP_WLOCKPCB, NULL); 2945 break; 2946 #endif 2947 #ifdef INET 2948 case AF_INET: 2949 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2950 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2951 break; 2952 #endif 2953 } 2954 if (inp != NULL) { 2955 if (inp->inp_flags & INP_TIMEWAIT) { 2956 /* 2957 * XXXRW: There currently exists a state where an 2958 * inpcb is present, but its timewait state has been 2959 * discarded. For now, don't allow dropping of this 2960 * type of inpcb. 2961 */ 2962 tw = intotw(inp); 2963 if (tw != NULL) 2964 tcp_twclose(tw, 0); 2965 else 2966 INP_WUNLOCK(inp); 2967 } else if (!(inp->inp_flags & INP_DROPPED) && 2968 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2969 tp = intotcpcb(inp); 2970 tp = tcp_drop(tp, ECONNABORTED); 2971 if (tp != NULL) 2972 INP_WUNLOCK(inp); 2973 } else 2974 INP_WUNLOCK(inp); 2975 } else 2976 error = ESRCH; 2977 INP_INFO_RUNLOCK(&V_tcbinfo); 2978 return (error); 2979 } 2980 2981 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2982 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2983 0, sysctl_drop, "", "Drop TCP connection"); 2984 2985 /* 2986 * Generate a standardized TCP log line for use throughout the 2987 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2988 * allow use in the interrupt context. 2989 * 2990 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2991 * NB: The function may return NULL if memory allocation failed. 2992 * 2993 * Due to header inclusion and ordering limitations the struct ip 2994 * and ip6_hdr pointers have to be passed as void pointers. 2995 */ 2996 char * 2997 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2998 const void *ip6hdr) 2999 { 3000 3001 /* Is logging enabled? */ 3002 if (tcp_log_in_vain == 0) 3003 return (NULL); 3004 3005 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3006 } 3007 3008 char * 3009 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3010 const void *ip6hdr) 3011 { 3012 3013 /* Is logging enabled? */ 3014 if (tcp_log_debug == 0) 3015 return (NULL); 3016 3017 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3018 } 3019 3020 static char * 3021 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3022 const void *ip6hdr) 3023 { 3024 char *s, *sp; 3025 size_t size; 3026 struct ip *ip; 3027 #ifdef INET6 3028 const struct ip6_hdr *ip6; 3029 3030 ip6 = (const struct ip6_hdr *)ip6hdr; 3031 #endif /* INET6 */ 3032 ip = (struct ip *)ip4hdr; 3033 3034 /* 3035 * The log line looks like this: 3036 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3037 */ 3038 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3039 sizeof(PRINT_TH_FLAGS) + 1 + 3040 #ifdef INET6 3041 2 * INET6_ADDRSTRLEN; 3042 #else 3043 2 * INET_ADDRSTRLEN; 3044 #endif /* INET6 */ 3045 3046 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3047 if (s == NULL) 3048 return (NULL); 3049 3050 strcat(s, "TCP: ["); 3051 sp = s + strlen(s); 3052 3053 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3054 inet_ntoa_r(inc->inc_faddr, sp); 3055 sp = s + strlen(s); 3056 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3057 sp = s + strlen(s); 3058 inet_ntoa_r(inc->inc_laddr, sp); 3059 sp = s + strlen(s); 3060 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3061 #ifdef INET6 3062 } else if (inc) { 3063 ip6_sprintf(sp, &inc->inc6_faddr); 3064 sp = s + strlen(s); 3065 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3066 sp = s + strlen(s); 3067 ip6_sprintf(sp, &inc->inc6_laddr); 3068 sp = s + strlen(s); 3069 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3070 } else if (ip6 && th) { 3071 ip6_sprintf(sp, &ip6->ip6_src); 3072 sp = s + strlen(s); 3073 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3074 sp = s + strlen(s); 3075 ip6_sprintf(sp, &ip6->ip6_dst); 3076 sp = s + strlen(s); 3077 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3078 #endif /* INET6 */ 3079 #ifdef INET 3080 } else if (ip && th) { 3081 inet_ntoa_r(ip->ip_src, sp); 3082 sp = s + strlen(s); 3083 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3084 sp = s + strlen(s); 3085 inet_ntoa_r(ip->ip_dst, sp); 3086 sp = s + strlen(s); 3087 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3088 #endif /* INET */ 3089 } else { 3090 free(s, M_TCPLOG); 3091 return (NULL); 3092 } 3093 sp = s + strlen(s); 3094 if (th) 3095 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3096 if (*(s + size - 1) != '\0') 3097 panic("%s: string too long", __func__); 3098 return (s); 3099 } 3100 3101 /* 3102 * A subroutine which makes it easy to track TCP state changes with DTrace. 3103 * This function shouldn't be called for t_state initializations that don't 3104 * correspond to actual TCP state transitions. 3105 */ 3106 void 3107 tcp_state_change(struct tcpcb *tp, int newstate) 3108 { 3109 #if defined(KDTRACE_HOOKS) 3110 int pstate = tp->t_state; 3111 #endif 3112 3113 TCPSTATES_DEC(tp->t_state); 3114 TCPSTATES_INC(newstate); 3115 tp->t_state = newstate; 3116 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3117 } 3118