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: stable/11/sys/netinet/tcp_subr.c 351523 2019-08-27 00:29:30Z jhb $"); 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#include <netipsec/ipsec_support.h> 118 119#include <machine/in_cksum.h> 120#include <sys/md5.h> 121 122#include <security/mac/mac_framework.h> 123 124VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 125#ifdef INET6 126VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 127#endif 128 129struct rwlock tcp_function_lock; 130 131static int 132sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 133{ 134 int error, new; 135 136 new = V_tcp_mssdflt; 137 error = sysctl_handle_int(oidp, &new, 0, req); 138 if (error == 0 && req->newptr) { 139 if (new < TCP_MINMSS) 140 error = EINVAL; 141 else 142 V_tcp_mssdflt = new; 143 } 144 return (error); 145} 146 147SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 148 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 149 &sysctl_net_inet_tcp_mss_check, "I", 150 "Default TCP Maximum Segment Size"); 151 152#ifdef INET6 153static int 154sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 155{ 156 int error, new; 157 158 new = V_tcp_v6mssdflt; 159 error = sysctl_handle_int(oidp, &new, 0, req); 160 if (error == 0 && req->newptr) { 161 if (new < TCP_MINMSS) 162 error = EINVAL; 163 else 164 V_tcp_v6mssdflt = new; 165 } 166 return (error); 167} 168 169SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 170 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 171 &sysctl_net_inet_tcp_mss_v6_check, "I", 172 "Default TCP Maximum Segment Size for IPv6"); 173#endif /* INET6 */ 174 175/* 176 * Minimum MSS we accept and use. This prevents DoS attacks where 177 * we are forced to a ridiculous low MSS like 20 and send hundreds 178 * of packets instead of one. The effect scales with the available 179 * bandwidth and quickly saturates the CPU and network interface 180 * with packet generation and sending. Set to zero to disable MINMSS 181 * checking. This setting prevents us from sending too small packets. 182 */ 183VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 184SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 185 &VNET_NAME(tcp_minmss), 0, 186 "Minimum TCP Maximum Segment Size"); 187 188VNET_DEFINE(int, tcp_do_rfc1323) = 1; 189SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 190 &VNET_NAME(tcp_do_rfc1323), 0, 191 "Enable rfc1323 (high performance TCP) extensions"); 192 193static int tcp_log_debug = 0; 194SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 195 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 196 197static int tcp_tcbhashsize; 198SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 199 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 200 201static int do_tcpdrain = 1; 202SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 203 "Enable tcp_drain routine for extra help when low on mbufs"); 204 205SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 206 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 207 208static VNET_DEFINE(int, icmp_may_rst) = 1; 209#define V_icmp_may_rst VNET(icmp_may_rst) 210SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 211 &VNET_NAME(icmp_may_rst), 0, 212 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 213 214static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 215#define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 216SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 217 &VNET_NAME(tcp_isn_reseed_interval), 0, 218 "Seconds between reseeding of ISN secret"); 219 220static int tcp_soreceive_stream; 221SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 222 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 223 224VNET_DEFINE(uma_zone_t, sack_hole_zone); 225#define V_sack_hole_zone VNET(sack_hole_zone) 226 227VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 228 229VNET_DEFINE(u_char, ts_offset_secret[32]); 230#define V_ts_offset_secret VNET(ts_offset_secret) 231 232static struct inpcb *tcp_notify(struct inpcb *, int); 233static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 234static void tcp_mtudisc(struct inpcb *, int); 235static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 236 void *ip4hdr, const void *ip6hdr); 237 238 239static struct tcp_function_block tcp_def_funcblk = { 240 "default", 241 tcp_output, 242 tcp_do_segment, 243 tcp_default_ctloutput, 244 NULL, 245 NULL, 246 NULL, 247 NULL, 248 NULL, 249 NULL, 250 0, 251 0 252}; 253 254int t_functions_inited = 0; 255struct tcp_funchead t_functions; 256static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 257 258static void 259init_tcp_functions(void) 260{ 261 if (t_functions_inited == 0) { 262 TAILQ_INIT(&t_functions); 263 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 264 t_functions_inited = 1; 265 } 266} 267 268static struct tcp_function_block * 269find_tcp_functions_locked(struct tcp_function_set *fs) 270{ 271 struct tcp_function *f; 272 struct tcp_function_block *blk=NULL; 273 274 TAILQ_FOREACH(f, &t_functions, tf_next) { 275 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 276 blk = f->tf_fb; 277 break; 278 } 279 } 280 return(blk); 281} 282 283static struct tcp_function_block * 284find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 285{ 286 struct tcp_function_block *rblk=NULL; 287 struct tcp_function *f; 288 289 TAILQ_FOREACH(f, &t_functions, tf_next) { 290 if (f->tf_fb == blk) { 291 rblk = blk; 292 if (s) { 293 *s = f; 294 } 295 break; 296 } 297 } 298 return (rblk); 299} 300 301struct tcp_function_block * 302find_and_ref_tcp_functions(struct tcp_function_set *fs) 303{ 304 struct tcp_function_block *blk; 305 306 rw_rlock(&tcp_function_lock); 307 blk = find_tcp_functions_locked(fs); 308 if (blk) 309 refcount_acquire(&blk->tfb_refcnt); 310 rw_runlock(&tcp_function_lock); 311 return(blk); 312} 313 314struct tcp_function_block * 315find_and_ref_tcp_fb(struct tcp_function_block *blk) 316{ 317 struct tcp_function_block *rblk; 318 319 rw_rlock(&tcp_function_lock); 320 rblk = find_tcp_fb_locked(blk, NULL); 321 if (rblk) 322 refcount_acquire(&rblk->tfb_refcnt); 323 rw_runlock(&tcp_function_lock); 324 return(rblk); 325} 326 327 328static int 329sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 330{ 331 int error=ENOENT; 332 struct tcp_function_set fs; 333 struct tcp_function_block *blk; 334 335 memset(&fs, 0, sizeof(fs)); 336 rw_rlock(&tcp_function_lock); 337 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 338 if (blk) { 339 /* Found him */ 340 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 341 fs.pcbcnt = blk->tfb_refcnt; 342 } 343 rw_runlock(&tcp_function_lock); 344 error = sysctl_handle_string(oidp, fs.function_set_name, 345 sizeof(fs.function_set_name), req); 346 347 /* Check for error or no change */ 348 if (error != 0 || req->newptr == NULL) 349 return(error); 350 351 rw_wlock(&tcp_function_lock); 352 blk = find_tcp_functions_locked(&fs); 353 if ((blk == NULL) || 354 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 355 error = ENOENT; 356 goto done; 357 } 358 tcp_func_set_ptr = blk; 359done: 360 rw_wunlock(&tcp_function_lock); 361 return (error); 362} 363 364SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 365 CTLTYPE_STRING | CTLFLAG_RW, 366 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 367 "Set/get the default TCP functions"); 368 369static int 370sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 371{ 372 int error, cnt, linesz; 373 struct tcp_function *f; 374 char *buffer, *cp; 375 size_t bufsz, outsz; 376 377 cnt = 0; 378 rw_rlock(&tcp_function_lock); 379 TAILQ_FOREACH(f, &t_functions, tf_next) { 380 cnt++; 381 } 382 rw_runlock(&tcp_function_lock); 383 384 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 385 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 386 387 error = 0; 388 cp = buffer; 389 390 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 391 cp += linesz; 392 bufsz -= linesz; 393 outsz = linesz; 394 395 rw_rlock(&tcp_function_lock); 396 TAILQ_FOREACH(f, &t_functions, tf_next) { 397 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 398 f->tf_fb->tfb_tcp_block_name, 399 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 400 f->tf_fb->tfb_refcnt); 401 if (linesz >= bufsz) { 402 error = EOVERFLOW; 403 break; 404 } 405 cp += linesz; 406 bufsz -= linesz; 407 outsz += linesz; 408 } 409 rw_runlock(&tcp_function_lock); 410 if (error == 0) 411 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 412 free(buffer, M_TEMP); 413 return (error); 414} 415 416SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 417 CTLTYPE_STRING|CTLFLAG_RD, 418 NULL, 0, sysctl_net_inet_list_available, "A", 419 "list available TCP Function sets"); 420 421/* 422 * Target size of TCP PCB hash tables. Must be a power of two. 423 * 424 * Note that this can be overridden by the kernel environment 425 * variable net.inet.tcp.tcbhashsize 426 */ 427#ifndef TCBHASHSIZE 428#define TCBHASHSIZE 0 429#endif 430 431/* 432 * XXX 433 * Callouts should be moved into struct tcp directly. They are currently 434 * separate because the tcpcb structure is exported to userland for sysctl 435 * parsing purposes, which do not know about callouts. 436 */ 437struct tcpcb_mem { 438 struct tcpcb tcb; 439 struct tcp_timer tt; 440 struct cc_var ccv; 441 struct osd osd; 442}; 443 444static VNET_DEFINE(uma_zone_t, tcpcb_zone); 445#define V_tcpcb_zone VNET(tcpcb_zone) 446 447MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 448MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 449 450static struct mtx isn_mtx; 451 452#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 453#define ISN_LOCK() mtx_lock(&isn_mtx) 454#define ISN_UNLOCK() mtx_unlock(&isn_mtx) 455 456/* 457 * TCP initialization. 458 */ 459static void 460tcp_zone_change(void *tag) 461{ 462 463 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 464 uma_zone_set_max(V_tcpcb_zone, maxsockets); 465 tcp_tw_zone_change(); 466} 467 468static int 469tcp_inpcb_init(void *mem, int size, int flags) 470{ 471 struct inpcb *inp = mem; 472 473 INP_LOCK_INIT(inp, "inp", "tcpinp"); 474 return (0); 475} 476 477/* 478 * Take a value and get the next power of 2 that doesn't overflow. 479 * Used to size the tcp_inpcb hash buckets. 480 */ 481static int 482maketcp_hashsize(int size) 483{ 484 int hashsize; 485 486 /* 487 * auto tune. 488 * get the next power of 2 higher than maxsockets. 489 */ 490 hashsize = 1 << fls(size); 491 /* catch overflow, and just go one power of 2 smaller */ 492 if (hashsize < size) { 493 hashsize = 1 << (fls(size) - 1); 494 } 495 return (hashsize); 496} 497 498int 499register_tcp_functions(struct tcp_function_block *blk, int wait) 500{ 501 struct tcp_function_block *lblk; 502 struct tcp_function *n; 503 struct tcp_function_set fs; 504 505 if (t_functions_inited == 0) { 506 init_tcp_functions(); 507 } 508 if ((blk->tfb_tcp_output == NULL) || 509 (blk->tfb_tcp_do_segment == NULL) || 510 (blk->tfb_tcp_ctloutput == NULL) || 511 (strlen(blk->tfb_tcp_block_name) == 0)) { 512 /* 513 * These functions are required and you 514 * need a name. 515 */ 516 return (EINVAL); 517 } 518 if (blk->tfb_tcp_timer_stop_all || 519 blk->tfb_tcp_timer_activate || 520 blk->tfb_tcp_timer_active || 521 blk->tfb_tcp_timer_stop) { 522 /* 523 * If you define one timer function you 524 * must have them all. 525 */ 526 if ((blk->tfb_tcp_timer_stop_all == NULL) || 527 (blk->tfb_tcp_timer_activate == NULL) || 528 (blk->tfb_tcp_timer_active == NULL) || 529 (blk->tfb_tcp_timer_stop == NULL)) { 530 return (EINVAL); 531 } 532 } 533 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 534 return (EINVAL); 535 } 536 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 537 if (n == NULL) { 538 return (ENOMEM); 539 } 540 n->tf_fb = blk; 541 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 542 rw_wlock(&tcp_function_lock); 543 lblk = find_tcp_functions_locked(&fs); 544 if (lblk) { 545 /* Duplicate name space not allowed */ 546 rw_wunlock(&tcp_function_lock); 547 free(n, M_TCPFUNCTIONS); 548 return (EALREADY); 549 } 550 refcount_init(&blk->tfb_refcnt, 0); 551 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 552 rw_wunlock(&tcp_function_lock); 553 return(0); 554} 555 556int 557deregister_tcp_functions(struct tcp_function_block *blk) 558{ 559 struct tcp_function_block *lblk; 560 struct tcp_function *f; 561 int error=ENOENT; 562 563 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 564 /* You can't un-register the default */ 565 return (EPERM); 566 } 567 rw_wlock(&tcp_function_lock); 568 if (blk == tcp_func_set_ptr) { 569 /* You can't free the current default */ 570 rw_wunlock(&tcp_function_lock); 571 return (EBUSY); 572 } 573 if (blk->tfb_refcnt) { 574 /* Still tcb attached, mark it. */ 575 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 576 rw_wunlock(&tcp_function_lock); 577 return (EBUSY); 578 } 579 lblk = find_tcp_fb_locked(blk, &f); 580 if (lblk) { 581 /* Found */ 582 TAILQ_REMOVE(&t_functions, f, tf_next); 583 f->tf_fb = NULL; 584 free(f, M_TCPFUNCTIONS); 585 error = 0; 586 } 587 rw_wunlock(&tcp_function_lock); 588 return (error); 589} 590 591void 592tcp_init(void) 593{ 594 const char *tcbhash_tuneable; 595 int hashsize; 596 597 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 598 599 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 600 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 601 printf("%s: WARNING: unable to register helper hook\n", __func__); 602 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 603 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 604 printf("%s: WARNING: unable to register helper hook\n", __func__); 605 hashsize = TCBHASHSIZE; 606 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 607 if (hashsize == 0) { 608 /* 609 * Auto tune the hash size based on maxsockets. 610 * A perfect hash would have a 1:1 mapping 611 * (hashsize = maxsockets) however it's been 612 * suggested that O(2) average is better. 613 */ 614 hashsize = maketcp_hashsize(maxsockets / 4); 615 /* 616 * Our historical default is 512, 617 * do not autotune lower than this. 618 */ 619 if (hashsize < 512) 620 hashsize = 512; 621 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 622 printf("%s: %s auto tuned to %d\n", __func__, 623 tcbhash_tuneable, hashsize); 624 } 625 /* 626 * We require a hashsize to be a power of two. 627 * Previously if it was not a power of two we would just reset it 628 * back to 512, which could be a nasty surprise if you did not notice 629 * the error message. 630 * Instead what we do is clip it to the closest power of two lower 631 * than the specified hash value. 632 */ 633 if (!powerof2(hashsize)) { 634 int oldhashsize = hashsize; 635 636 hashsize = maketcp_hashsize(hashsize); 637 /* prevent absurdly low value */ 638 if (hashsize < 16) 639 hashsize = 16; 640 printf("%s: WARNING: TCB hash size not a power of 2, " 641 "clipped from %d to %d.\n", __func__, oldhashsize, 642 hashsize); 643 } 644 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 645 "tcp_inpcb", tcp_inpcb_init, NULL, 0, IPI_HASHFIELDS_4TUPLE); 646 647 /* 648 * These have to be type stable for the benefit of the timers. 649 */ 650 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 651 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 652 uma_zone_set_max(V_tcpcb_zone, maxsockets); 653 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 654 655 tcp_tw_init(); 656 syncache_init(); 657 tcp_hc_init(); 658 659 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 660 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 661 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 662 663#ifdef TCP_RFC7413 664 tcp_fastopen_init(); 665#endif 666 667 /* Skip initialization of globals for non-default instances. */ 668 if (!IS_DEFAULT_VNET(curvnet)) 669 return; 670 671 tcp_reass_global_init(); 672 673 /* XXX virtualize those bellow? */ 674 tcp_delacktime = TCPTV_DELACK; 675 tcp_keepinit = TCPTV_KEEP_INIT; 676 tcp_keepidle = TCPTV_KEEP_IDLE; 677 tcp_keepintvl = TCPTV_KEEPINTVL; 678 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 679 tcp_msl = TCPTV_MSL; 680 tcp_rexmit_min = TCPTV_MIN; 681 if (tcp_rexmit_min < 1) 682 tcp_rexmit_min = 1; 683 tcp_persmin = TCPTV_PERSMIN; 684 tcp_persmax = TCPTV_PERSMAX; 685 tcp_rexmit_slop = TCPTV_CPU_VAR; 686 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 687 tcp_tcbhashsize = hashsize; 688 /* Setup the tcp function block list */ 689 init_tcp_functions(); 690 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 691 read_random(&V_ts_offset_secret, sizeof(V_ts_offset_secret)); 692 693 if (tcp_soreceive_stream) { 694#ifdef INET 695 tcp_usrreqs.pru_soreceive = soreceive_stream; 696#endif 697#ifdef INET6 698 tcp6_usrreqs.pru_soreceive = soreceive_stream; 699#endif /* INET6 */ 700 } 701 702#ifdef INET6 703#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 704#else /* INET6 */ 705#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 706#endif /* INET6 */ 707 if (max_protohdr < TCP_MINPROTOHDR) 708 max_protohdr = TCP_MINPROTOHDR; 709 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 710 panic("tcp_init"); 711#undef TCP_MINPROTOHDR 712 713 ISN_LOCK_INIT(); 714 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 715 SHUTDOWN_PRI_DEFAULT); 716 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 717 EVENTHANDLER_PRI_ANY); 718#ifdef TCPPCAP 719 tcp_pcap_init(); 720#endif 721} 722 723#ifdef VIMAGE 724static void 725tcp_destroy(void *unused __unused) 726{ 727 int error, n; 728 729 /* 730 * All our processes are gone, all our sockets should be cleaned 731 * up, which means, we should be past the tcp_discardcb() calls. 732 * Sleep to let all tcpcb timers really disappear and cleanup. 733 */ 734 for (;;) { 735 INP_LIST_RLOCK(&V_tcbinfo); 736 n = V_tcbinfo.ipi_count; 737 INP_LIST_RUNLOCK(&V_tcbinfo); 738 if (n == 0) 739 break; 740 pause("tcpdes", hz / 10); 741 } 742 tcp_hc_destroy(); 743 syncache_destroy(); 744 tcp_tw_destroy(); 745 in_pcbinfo_destroy(&V_tcbinfo); 746 /* tcp_discardcb() clears the sack_holes up. */ 747 uma_zdestroy(V_sack_hole_zone); 748 uma_zdestroy(V_tcpcb_zone); 749 750#ifdef TCP_RFC7413 751 /* 752 * Cannot free the zone until all tcpcbs are released as we attach 753 * the allocations to them. 754 */ 755 tcp_fastopen_destroy(); 756#endif 757 758 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 759 if (error != 0) { 760 printf("%s: WARNING: unable to deregister helper hook " 761 "type=%d, id=%d: error %d returned\n", __func__, 762 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 763 } 764 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 765 if (error != 0) { 766 printf("%s: WARNING: unable to deregister helper hook " 767 "type=%d, id=%d: error %d returned\n", __func__, 768 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 769 } 770} 771VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 772#endif 773 774void 775tcp_fini(void *xtp) 776{ 777 778} 779 780/* 781 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 782 * tcp_template used to store this data in mbufs, but we now recopy it out 783 * of the tcpcb each time to conserve mbufs. 784 */ 785void 786tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 787{ 788 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 789 790 INP_WLOCK_ASSERT(inp); 791 792#ifdef INET6 793 if ((inp->inp_vflag & INP_IPV6) != 0) { 794 struct ip6_hdr *ip6; 795 796 ip6 = (struct ip6_hdr *)ip_ptr; 797 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 798 (inp->inp_flow & IPV6_FLOWINFO_MASK); 799 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 800 (IPV6_VERSION & IPV6_VERSION_MASK); 801 ip6->ip6_nxt = IPPROTO_TCP; 802 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 803 ip6->ip6_src = inp->in6p_laddr; 804 ip6->ip6_dst = inp->in6p_faddr; 805 } 806#endif /* INET6 */ 807#if defined(INET6) && defined(INET) 808 else 809#endif 810#ifdef INET 811 { 812 struct ip *ip; 813 814 ip = (struct ip *)ip_ptr; 815 ip->ip_v = IPVERSION; 816 ip->ip_hl = 5; 817 ip->ip_tos = inp->inp_ip_tos; 818 ip->ip_len = 0; 819 ip->ip_id = 0; 820 ip->ip_off = 0; 821 ip->ip_ttl = inp->inp_ip_ttl; 822 ip->ip_sum = 0; 823 ip->ip_p = IPPROTO_TCP; 824 ip->ip_src = inp->inp_laddr; 825 ip->ip_dst = inp->inp_faddr; 826 } 827#endif /* INET */ 828 th->th_sport = inp->inp_lport; 829 th->th_dport = inp->inp_fport; 830 th->th_seq = 0; 831 th->th_ack = 0; 832 th->th_x2 = 0; 833 th->th_off = 5; 834 th->th_flags = 0; 835 th->th_win = 0; 836 th->th_urp = 0; 837 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 838} 839 840/* 841 * Create template to be used to send tcp packets on a connection. 842 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 843 * use for this function is in keepalives, which use tcp_respond. 844 */ 845struct tcptemp * 846tcpip_maketemplate(struct inpcb *inp) 847{ 848 struct tcptemp *t; 849 850 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 851 if (t == NULL) 852 return (NULL); 853 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 854 return (t); 855} 856 857/* 858 * Send a single message to the TCP at address specified by 859 * the given TCP/IP header. If m == NULL, then we make a copy 860 * of the tcpiphdr at th and send directly to the addressed host. 861 * This is used to force keep alive messages out using the TCP 862 * template for a connection. If flags are given then we send 863 * a message back to the TCP which originated the segment th, 864 * and discard the mbuf containing it and any other attached mbufs. 865 * 866 * In any case the ack and sequence number of the transmitted 867 * segment are as specified by the parameters. 868 * 869 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 870 */ 871void 872tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 873 tcp_seq ack, tcp_seq seq, int flags) 874{ 875 struct tcpopt to; 876 struct inpcb *inp; 877 struct ip *ip; 878 struct mbuf *optm; 879 struct tcphdr *nth; 880 u_char *optp; 881#ifdef INET6 882 struct ip6_hdr *ip6; 883 int isipv6; 884#endif /* INET6 */ 885 int optlen, tlen, win; 886 bool incl_opts; 887 888 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 889 890#ifdef INET6 891 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 892 ip6 = ipgen; 893#endif /* INET6 */ 894 ip = ipgen; 895 896 if (tp != NULL) { 897 inp = tp->t_inpcb; 898 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 899 INP_WLOCK_ASSERT(inp); 900 } else 901 inp = NULL; 902 903 incl_opts = false; 904 win = 0; 905 if (tp != NULL) { 906 if (!(flags & TH_RST)) { 907 win = sbspace(&inp->inp_socket->so_rcv); 908 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 909 win = (long)TCP_MAXWIN << tp->rcv_scale; 910 } 911 if ((tp->t_flags & TF_NOOPT) == 0) 912 incl_opts = true; 913 } 914 if (m == NULL) { 915 m = m_gethdr(M_NOWAIT, MT_DATA); 916 if (m == NULL) 917 return; 918 m->m_data += max_linkhdr; 919#ifdef INET6 920 if (isipv6) { 921 bcopy((caddr_t)ip6, mtod(m, caddr_t), 922 sizeof(struct ip6_hdr)); 923 ip6 = mtod(m, struct ip6_hdr *); 924 nth = (struct tcphdr *)(ip6 + 1); 925 } else 926#endif /* INET6 */ 927 { 928 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 929 ip = mtod(m, struct ip *); 930 nth = (struct tcphdr *)(ip + 1); 931 } 932 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 933 flags = TH_ACK; 934 } else if (!M_WRITABLE(m)) { 935 struct mbuf *n; 936 937 /* Can't reuse 'm', allocate a new mbuf. */ 938 n = m_gethdr(M_NOWAIT, MT_DATA); 939 if (n == NULL) { 940 m_freem(m); 941 return; 942 } 943 944 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 945 m_freem(m); 946 m_freem(n); 947 return; 948 } 949 950 n->m_data += max_linkhdr; 951 /* m_len is set later */ 952#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 953#ifdef INET6 954 if (isipv6) { 955 bcopy((caddr_t)ip6, mtod(n, caddr_t), 956 sizeof(struct ip6_hdr)); 957 ip6 = mtod(n, struct ip6_hdr *); 958 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 959 nth = (struct tcphdr *)(ip6 + 1); 960 } else 961#endif /* INET6 */ 962 { 963 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 964 ip = mtod(n, struct ip *); 965 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 966 nth = (struct tcphdr *)(ip + 1); 967 } 968 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 969 xchg(nth->th_dport, nth->th_sport, uint16_t); 970 th = nth; 971 m_freem(m); 972 m = n; 973 } else { 974 /* 975 * reuse the mbuf. 976 * XXX MRT We inherit the FIB, which is lucky. 977 */ 978 m_freem(m->m_next); 979 m->m_next = NULL; 980 m->m_data = (caddr_t)ipgen; 981 /* m_len is set later */ 982#ifdef INET6 983 if (isipv6) { 984 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 985 nth = (struct tcphdr *)(ip6 + 1); 986 } else 987#endif /* INET6 */ 988 { 989 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 990 nth = (struct tcphdr *)(ip + 1); 991 } 992 if (th != nth) { 993 /* 994 * this is usually a case when an extension header 995 * exists between the IPv6 header and the 996 * TCP header. 997 */ 998 nth->th_sport = th->th_sport; 999 nth->th_dport = th->th_dport; 1000 } 1001 xchg(nth->th_dport, nth->th_sport, uint16_t); 1002#undef xchg 1003 } 1004 tlen = 0; 1005#ifdef INET6 1006 if (isipv6) 1007 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1008#endif 1009#if defined(INET) && defined(INET6) 1010 else 1011#endif 1012#ifdef INET 1013 tlen = sizeof (struct tcpiphdr); 1014#endif 1015#ifdef INVARIANTS 1016 m->m_len = 0; 1017 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1018 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1019 m, tlen, (long)M_TRAILINGSPACE(m))); 1020#endif 1021 m->m_len = tlen; 1022 to.to_flags = 0; 1023 if (incl_opts) { 1024 /* Make sure we have room. */ 1025 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1026 m->m_next = m_get(M_NOWAIT, MT_DATA); 1027 if (m->m_next) { 1028 optp = mtod(m->m_next, u_char *); 1029 optm = m->m_next; 1030 } else 1031 incl_opts = false; 1032 } else { 1033 optp = (u_char *) (nth + 1); 1034 optm = m; 1035 } 1036 } 1037 if (incl_opts) { 1038 /* Timestamps. */ 1039 if (tp->t_flags & TF_RCVD_TSTMP) { 1040 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1041 to.to_tsecr = tp->ts_recent; 1042 to.to_flags |= TOF_TS; 1043 } 1044#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1045 /* TCP-MD5 (RFC2385). */ 1046 if (tp->t_flags & TF_SIGNATURE) 1047 to.to_flags |= TOF_SIGNATURE; 1048#endif 1049 /* Add the options. */ 1050 tlen += optlen = tcp_addoptions(&to, optp); 1051 1052 /* Update m_len in the correct mbuf. */ 1053 optm->m_len += optlen; 1054 } else 1055 optlen = 0; 1056#ifdef INET6 1057 if (isipv6) { 1058 ip6->ip6_flow = 0; 1059 ip6->ip6_vfc = IPV6_VERSION; 1060 ip6->ip6_nxt = IPPROTO_TCP; 1061 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1062 } 1063#endif 1064#if defined(INET) && defined(INET6) 1065 else 1066#endif 1067#ifdef INET 1068 { 1069 ip->ip_len = htons(tlen); 1070 ip->ip_ttl = V_ip_defttl; 1071 if (V_path_mtu_discovery) 1072 ip->ip_off |= htons(IP_DF); 1073 } 1074#endif 1075 m->m_pkthdr.len = tlen; 1076 m->m_pkthdr.rcvif = NULL; 1077#ifdef MAC 1078 if (inp != NULL) { 1079 /* 1080 * Packet is associated with a socket, so allow the 1081 * label of the response to reflect the socket label. 1082 */ 1083 INP_WLOCK_ASSERT(inp); 1084 mac_inpcb_create_mbuf(inp, m); 1085 } else { 1086 /* 1087 * Packet is not associated with a socket, so possibly 1088 * update the label in place. 1089 */ 1090 mac_netinet_tcp_reply(m); 1091 } 1092#endif 1093 nth->th_seq = htonl(seq); 1094 nth->th_ack = htonl(ack); 1095 nth->th_x2 = 0; 1096 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1097 nth->th_flags = flags; 1098 if (tp != NULL) 1099 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1100 else 1101 nth->th_win = htons((u_short)win); 1102 nth->th_urp = 0; 1103 1104#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1105 if (to.to_flags & TOF_SIGNATURE) { 1106 if (!TCPMD5_ENABLED() || 1107 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1108 m_freem(m); 1109 return; 1110 } 1111 } 1112#endif 1113 1114 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1115#ifdef INET6 1116 if (isipv6) { 1117 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1118 nth->th_sum = in6_cksum_pseudo(ip6, 1119 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1120 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1121 NULL, NULL); 1122 } 1123#endif /* INET6 */ 1124#if defined(INET6) && defined(INET) 1125 else 1126#endif 1127#ifdef INET 1128 { 1129 m->m_pkthdr.csum_flags = CSUM_TCP; 1130 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1131 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1132 } 1133#endif /* INET */ 1134#ifdef TCPDEBUG 1135 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1136 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1137#endif 1138 TCP_PROBE3(debug__output, tp, th, m); 1139 if (flags & TH_RST) 1140 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1141 1142#ifdef INET6 1143 if (isipv6) { 1144 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1145 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1146 } 1147#endif /* INET6 */ 1148#if defined(INET) && defined(INET6) 1149 else 1150#endif 1151#ifdef INET 1152 { 1153 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1154 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1155 } 1156#endif 1157} 1158 1159/* 1160 * Create a new TCP control block, making an 1161 * empty reassembly queue and hooking it to the argument 1162 * protocol control block. The `inp' parameter must have 1163 * come from the zone allocator set up in tcp_init(). 1164 */ 1165struct tcpcb * 1166tcp_newtcpcb(struct inpcb *inp) 1167{ 1168 struct tcpcb_mem *tm; 1169 struct tcpcb *tp; 1170#ifdef INET6 1171 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1172#endif /* INET6 */ 1173 1174 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1175 if (tm == NULL) 1176 return (NULL); 1177 tp = &tm->tcb; 1178 1179 /* Initialise cc_var struct for this tcpcb. */ 1180 tp->ccv = &tm->ccv; 1181 tp->ccv->type = IPPROTO_TCP; 1182 tp->ccv->ccvc.tcp = tp; 1183 rw_rlock(&tcp_function_lock); 1184 tp->t_fb = tcp_func_set_ptr; 1185 refcount_acquire(&tp->t_fb->tfb_refcnt); 1186 rw_runlock(&tcp_function_lock); 1187 if (tp->t_fb->tfb_tcp_fb_init) { 1188 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1189 } 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); 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); 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 TAILQ_INIT(&tp->t_segq); 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 return (tp); /* XXX */ 1272} 1273 1274/* 1275 * Switch the congestion control algorithm back to NewReno for any active 1276 * control blocks using an algorithm which is about to go away. 1277 * This ensures the CC framework can allow the unload to proceed without leaving 1278 * any dangling pointers which would trigger a panic. 1279 * Returning non-zero would inform the CC framework that something went wrong 1280 * and it would be unsafe to allow the unload to proceed. However, there is no 1281 * way for this to occur with this implementation so we always return zero. 1282 */ 1283int 1284tcp_ccalgounload(struct cc_algo *unload_algo) 1285{ 1286 struct cc_algo *tmpalgo; 1287 struct inpcb *inp; 1288 struct tcpcb *tp; 1289 VNET_ITERATOR_DECL(vnet_iter); 1290 1291 /* 1292 * Check all active control blocks across all network stacks and change 1293 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1294 * requires cleanup code to be run, call it. 1295 */ 1296 VNET_LIST_RLOCK(); 1297 VNET_FOREACH(vnet_iter) { 1298 CURVNET_SET(vnet_iter); 1299 INP_INFO_WLOCK(&V_tcbinfo); 1300 /* 1301 * New connections already part way through being initialised 1302 * with the CC algo we're removing will not race with this code 1303 * because the INP_INFO_WLOCK is held during initialisation. We 1304 * therefore don't enter the loop below until the connection 1305 * list has stabilised. 1306 */ 1307 LIST_FOREACH(inp, &V_tcb, inp_list) { 1308 INP_WLOCK(inp); 1309 /* Important to skip tcptw structs. */ 1310 if (!(inp->inp_flags & INP_TIMEWAIT) && 1311 (tp = intotcpcb(inp)) != NULL) { 1312 /* 1313 * By holding INP_WLOCK here, we are assured 1314 * that the connection is not currently 1315 * executing inside the CC module's functions 1316 * i.e. it is safe to make the switch back to 1317 * NewReno. 1318 */ 1319 if (CC_ALGO(tp) == unload_algo) { 1320 tmpalgo = CC_ALGO(tp); 1321 /* NewReno does not require any init. */ 1322 CC_ALGO(tp) = &newreno_cc_algo; 1323 if (tmpalgo->cb_destroy != NULL) 1324 tmpalgo->cb_destroy(tp->ccv); 1325 } 1326 } 1327 INP_WUNLOCK(inp); 1328 } 1329 INP_INFO_WUNLOCK(&V_tcbinfo); 1330 CURVNET_RESTORE(); 1331 } 1332 VNET_LIST_RUNLOCK(); 1333 1334 return (0); 1335} 1336 1337/* 1338 * Drop a TCP connection, reporting 1339 * the specified error. If connection is synchronized, 1340 * then send a RST to peer. 1341 */ 1342struct tcpcb * 1343tcp_drop(struct tcpcb *tp, int errno) 1344{ 1345 struct socket *so = tp->t_inpcb->inp_socket; 1346 1347 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1348 INP_WLOCK_ASSERT(tp->t_inpcb); 1349 1350 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1351 tcp_state_change(tp, TCPS_CLOSED); 1352 (void) tp->t_fb->tfb_tcp_output(tp); 1353 TCPSTAT_INC(tcps_drops); 1354 } else 1355 TCPSTAT_INC(tcps_conndrops); 1356 if (errno == ETIMEDOUT && tp->t_softerror) 1357 errno = tp->t_softerror; 1358 so->so_error = errno; 1359 return (tcp_close(tp)); 1360} 1361 1362void 1363tcp_discardcb(struct tcpcb *tp) 1364{ 1365 struct inpcb *inp = tp->t_inpcb; 1366 struct socket *so = inp->inp_socket; 1367#ifdef INET6 1368 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1369#endif /* INET6 */ 1370 int released; 1371 1372 INP_WLOCK_ASSERT(inp); 1373 1374 /* 1375 * Make sure that all of our timers are stopped before we delete the 1376 * PCB. 1377 * 1378 * If stopping a timer fails, we schedule a discard function in same 1379 * callout, and the last discard function called will take care of 1380 * deleting the tcpcb. 1381 */ 1382 tp->t_timers->tt_draincnt = 0; 1383 tcp_timer_stop(tp, TT_REXMT); 1384 tcp_timer_stop(tp, TT_PERSIST); 1385 tcp_timer_stop(tp, TT_KEEP); 1386 tcp_timer_stop(tp, TT_2MSL); 1387 tcp_timer_stop(tp, TT_DELACK); 1388 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1389 /* 1390 * Call the stop-all function of the methods, 1391 * this function should call the tcp_timer_stop() 1392 * method with each of the function specific timeouts. 1393 * That stop will be called via the tfb_tcp_timer_stop() 1394 * which should use the async drain function of the 1395 * callout system (see tcp_var.h). 1396 */ 1397 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1398 } 1399 1400 /* 1401 * If we got enough samples through the srtt filter, 1402 * save the rtt and rttvar in the routing entry. 1403 * 'Enough' is arbitrarily defined as 4 rtt samples. 1404 * 4 samples is enough for the srtt filter to converge 1405 * to within enough % of the correct value; fewer samples 1406 * and we could save a bogus rtt. The danger is not high 1407 * as tcp quickly recovers from everything. 1408 * XXX: Works very well but needs some more statistics! 1409 */ 1410 if (tp->t_rttupdated >= 4) { 1411 struct hc_metrics_lite metrics; 1412 u_long ssthresh; 1413 1414 bzero(&metrics, sizeof(metrics)); 1415 /* 1416 * Update the ssthresh always when the conditions below 1417 * are satisfied. This gives us better new start value 1418 * for the congestion avoidance for new connections. 1419 * ssthresh is only set if packet loss occurred on a session. 1420 * 1421 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1422 * being torn down. Ideally this code would not use 'so'. 1423 */ 1424 ssthresh = tp->snd_ssthresh; 1425 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1426 /* 1427 * convert the limit from user data bytes to 1428 * packets then to packet data bytes. 1429 */ 1430 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1431 if (ssthresh < 2) 1432 ssthresh = 2; 1433 ssthresh *= (u_long)(tp->t_maxseg + 1434#ifdef INET6 1435 (isipv6 ? sizeof (struct ip6_hdr) + 1436 sizeof (struct tcphdr) : 1437#endif 1438 sizeof (struct tcpiphdr) 1439#ifdef INET6 1440 ) 1441#endif 1442 ); 1443 } else 1444 ssthresh = 0; 1445 metrics.rmx_ssthresh = ssthresh; 1446 1447 metrics.rmx_rtt = tp->t_srtt; 1448 metrics.rmx_rttvar = tp->t_rttvar; 1449 metrics.rmx_cwnd = tp->snd_cwnd; 1450 metrics.rmx_sendpipe = 0; 1451 metrics.rmx_recvpipe = 0; 1452 1453 tcp_hc_update(&inp->inp_inc, &metrics); 1454 } 1455 1456 /* free the reassembly queue, if any */ 1457 tcp_reass_flush(tp); 1458 1459#ifdef TCP_OFFLOAD 1460 /* Disconnect offload device, if any. */ 1461 if (tp->t_flags & TF_TOE) 1462 tcp_offload_detach(tp); 1463#endif 1464 1465 tcp_free_sackholes(tp); 1466 1467#ifdef TCPPCAP 1468 /* Free the TCP PCAP queues. */ 1469 tcp_pcap_drain(&(tp->t_inpkts)); 1470 tcp_pcap_drain(&(tp->t_outpkts)); 1471#endif 1472 1473 /* Allow the CC algorithm to clean up after itself. */ 1474 if (CC_ALGO(tp)->cb_destroy != NULL) 1475 CC_ALGO(tp)->cb_destroy(tp->ccv); 1476 1477 khelp_destroy_osd(tp->osd); 1478 1479 CC_ALGO(tp) = NULL; 1480 inp->inp_ppcb = NULL; 1481 if (tp->t_timers->tt_draincnt == 0) { 1482 /* We own the last reference on tcpcb, let's free it. */ 1483 TCPSTATES_DEC(tp->t_state); 1484 if (tp->t_fb->tfb_tcp_fb_fini) 1485 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1486 refcount_release(&tp->t_fb->tfb_refcnt); 1487 tp->t_inpcb = NULL; 1488 uma_zfree(V_tcpcb_zone, tp); 1489 released = in_pcbrele_wlocked(inp); 1490 KASSERT(!released, ("%s: inp %p should not have been released " 1491 "here", __func__, inp)); 1492 } 1493} 1494 1495void 1496tcp_timer_discard(void *ptp) 1497{ 1498 struct inpcb *inp; 1499 struct tcpcb *tp; 1500 1501 tp = (struct tcpcb *)ptp; 1502 CURVNET_SET(tp->t_vnet); 1503 INP_INFO_RLOCK(&V_tcbinfo); 1504 inp = tp->t_inpcb; 1505 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1506 __func__, tp)); 1507 INP_WLOCK(inp); 1508 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1509 ("%s: tcpcb has to be stopped here", __func__)); 1510 tp->t_timers->tt_draincnt--; 1511 if (tp->t_timers->tt_draincnt == 0) { 1512 /* We own the last reference on this tcpcb, let's free it. */ 1513 TCPSTATES_DEC(tp->t_state); 1514 if (tp->t_fb->tfb_tcp_fb_fini) 1515 (*tp->t_fb->tfb_tcp_fb_fini)(tp); 1516 refcount_release(&tp->t_fb->tfb_refcnt); 1517 tp->t_inpcb = NULL; 1518 uma_zfree(V_tcpcb_zone, tp); 1519 if (in_pcbrele_wlocked(inp)) { 1520 INP_INFO_RUNLOCK(&V_tcbinfo); 1521 CURVNET_RESTORE(); 1522 return; 1523 } 1524 } 1525 INP_WUNLOCK(inp); 1526 INP_INFO_RUNLOCK(&V_tcbinfo); 1527 CURVNET_RESTORE(); 1528} 1529 1530/* 1531 * Attempt to close a TCP control block, marking it as dropped, and freeing 1532 * the socket if we hold the only reference. 1533 */ 1534struct tcpcb * 1535tcp_close(struct tcpcb *tp) 1536{ 1537 struct inpcb *inp = tp->t_inpcb; 1538 struct socket *so; 1539 1540 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1541 INP_WLOCK_ASSERT(inp); 1542 1543#ifdef TCP_OFFLOAD 1544 if (tp->t_state == TCPS_LISTEN) 1545 tcp_offload_listen_stop(tp); 1546#endif 1547#ifdef TCP_RFC7413 1548 /* 1549 * This releases the TFO pending counter resource for TFO listen 1550 * sockets as well as passively-created TFO sockets that transition 1551 * from SYN_RECEIVED to CLOSED. 1552 */ 1553 if (tp->t_tfo_pending) { 1554 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1555 tp->t_tfo_pending = NULL; 1556 } 1557#endif 1558 in_pcbdrop(inp); 1559 TCPSTAT_INC(tcps_closed); 1560 if (tp->t_state != TCPS_CLOSED) 1561 tcp_state_change(tp, TCPS_CLOSED); 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 1579void 1580tcp_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 */ 1633static struct inpcb * 1634tcp_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 1681static int 1682tcp_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 bzero(&xig, sizeof(xig)); 1720 xig.xig_len = sizeof xig; 1721 xig.xig_count = n + m; 1722 xig.xig_gen = gencnt; 1723 xig.xig_sogen = so_gencnt; 1724 error = SYSCTL_OUT(req, &xig, sizeof xig); 1725 if (error) 1726 return (error); 1727 1728 error = syncache_pcblist(req, m, &pcb_count); 1729 if (error) 1730 return (error); 1731 1732 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1733 1734 INP_INFO_WLOCK(&V_tcbinfo); 1735 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1736 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1737 INP_WLOCK(inp); 1738 if (inp->inp_gencnt <= gencnt) { 1739 /* 1740 * XXX: This use of cr_cansee(), introduced with 1741 * TCP state changes, is not quite right, but for 1742 * now, better than nothing. 1743 */ 1744 if (inp->inp_flags & INP_TIMEWAIT) { 1745 if (intotw(inp) != NULL) 1746 error = cr_cansee(req->td->td_ucred, 1747 intotw(inp)->tw_cred); 1748 else 1749 error = EINVAL; /* Skip this inp. */ 1750 } else 1751 error = cr_canseeinpcb(req->td->td_ucred, inp); 1752 if (error == 0) { 1753 in_pcbref(inp); 1754 inp_list[i++] = inp; 1755 } 1756 } 1757 INP_WUNLOCK(inp); 1758 } 1759 INP_INFO_WUNLOCK(&V_tcbinfo); 1760 n = i; 1761 1762 error = 0; 1763 for (i = 0; i < n; i++) { 1764 inp = inp_list[i]; 1765 INP_RLOCK(inp); 1766 if (inp->inp_gencnt <= gencnt) { 1767 struct xtcpcb xt; 1768 void *inp_ppcb; 1769 1770 bzero(&xt, sizeof(xt)); 1771 xt.xt_len = sizeof xt; 1772 /* XXX should avoid extra copy */ 1773 bcopy(inp, &xt.xt_inp, sizeof *inp); 1774 inp_ppcb = inp->inp_ppcb; 1775 if (inp_ppcb == NULL) 1776 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1777 else if (inp->inp_flags & INP_TIMEWAIT) { 1778 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1779 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1780 } else { 1781 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1782 if (xt.xt_tp.t_timers) 1783 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1784 } 1785 if (inp->inp_socket != NULL) 1786 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1787 else { 1788 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1789 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1790 } 1791 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1792 INP_RUNLOCK(inp); 1793 error = SYSCTL_OUT(req, &xt, sizeof xt); 1794 } else 1795 INP_RUNLOCK(inp); 1796 } 1797 INP_INFO_RLOCK(&V_tcbinfo); 1798 for (i = 0; i < n; i++) { 1799 inp = inp_list[i]; 1800 INP_RLOCK(inp); 1801 if (!in_pcbrele_rlocked(inp)) 1802 INP_RUNLOCK(inp); 1803 } 1804 INP_INFO_RUNLOCK(&V_tcbinfo); 1805 1806 if (!error) { 1807 /* 1808 * Give the user an updated idea of our state. 1809 * If the generation differs from what we told 1810 * her before, she knows that something happened 1811 * while we were processing this request, and it 1812 * might be necessary to retry. 1813 */ 1814 INP_LIST_RLOCK(&V_tcbinfo); 1815 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1816 xig.xig_sogen = so_gencnt; 1817 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1818 INP_LIST_RUNLOCK(&V_tcbinfo); 1819 error = SYSCTL_OUT(req, &xig, sizeof xig); 1820 } 1821 free(inp_list, M_TEMP); 1822 return (error); 1823} 1824 1825SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1826 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1827 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1828 1829#ifdef INET 1830static int 1831tcp_getcred(SYSCTL_HANDLER_ARGS) 1832{ 1833 struct xucred xuc; 1834 struct sockaddr_in addrs[2]; 1835 struct inpcb *inp; 1836 int error; 1837 1838 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1839 if (error) 1840 return (error); 1841 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1842 if (error) 1843 return (error); 1844 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1845 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1846 if (inp != NULL) { 1847 if (inp->inp_socket == NULL) 1848 error = ENOENT; 1849 if (error == 0) 1850 error = cr_canseeinpcb(req->td->td_ucred, inp); 1851 if (error == 0) 1852 cru2x(inp->inp_cred, &xuc); 1853 INP_RUNLOCK(inp); 1854 } else 1855 error = ENOENT; 1856 if (error == 0) 1857 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1858 return (error); 1859} 1860 1861SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1862 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1863 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1864#endif /* INET */ 1865 1866#ifdef INET6 1867static int 1868tcp6_getcred(SYSCTL_HANDLER_ARGS) 1869{ 1870 struct xucred xuc; 1871 struct sockaddr_in6 addrs[2]; 1872 struct inpcb *inp; 1873 int error; 1874#ifdef INET 1875 int mapped = 0; 1876#endif 1877 1878 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1879 if (error) 1880 return (error); 1881 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1882 if (error) 1883 return (error); 1884 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1885 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1886 return (error); 1887 } 1888 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1889#ifdef INET 1890 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1891 mapped = 1; 1892 else 1893#endif 1894 return (EINVAL); 1895 } 1896 1897#ifdef INET 1898 if (mapped == 1) 1899 inp = in_pcblookup(&V_tcbinfo, 1900 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1901 addrs[1].sin6_port, 1902 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1903 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1904 else 1905#endif 1906 inp = in6_pcblookup(&V_tcbinfo, 1907 &addrs[1].sin6_addr, addrs[1].sin6_port, 1908 &addrs[0].sin6_addr, addrs[0].sin6_port, 1909 INPLOOKUP_RLOCKPCB, NULL); 1910 if (inp != NULL) { 1911 if (inp->inp_socket == NULL) 1912 error = ENOENT; 1913 if (error == 0) 1914 error = cr_canseeinpcb(req->td->td_ucred, inp); 1915 if (error == 0) 1916 cru2x(inp->inp_cred, &xuc); 1917 INP_RUNLOCK(inp); 1918 } else 1919 error = ENOENT; 1920 if (error == 0) 1921 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1922 return (error); 1923} 1924 1925SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1926 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1927 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1928#endif /* INET6 */ 1929 1930 1931#ifdef INET 1932void 1933tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1934{ 1935 struct ip *ip = vip; 1936 struct tcphdr *th; 1937 struct in_addr faddr; 1938 struct inpcb *inp; 1939 struct tcpcb *tp; 1940 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1941 struct icmp *icp; 1942 struct in_conninfo inc; 1943 tcp_seq icmp_tcp_seq; 1944 int mtu; 1945 1946 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1947 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1948 return; 1949 1950 if (cmd == PRC_MSGSIZE) 1951 notify = tcp_mtudisc_notify; 1952 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1953 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 1954 cmd == PRC_TIMXCEED_INTRANS) && ip) 1955 notify = tcp_drop_syn_sent; 1956 1957 /* 1958 * Hostdead is ugly because it goes linearly through all PCBs. 1959 * XXX: We never get this from ICMP, otherwise it makes an 1960 * excellent DoS attack on machines with many connections. 1961 */ 1962 else if (cmd == PRC_HOSTDEAD) 1963 ip = NULL; 1964 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1965 return; 1966 1967 if (ip == NULL) { 1968 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1969 return; 1970 } 1971 1972 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1973 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1974 INP_INFO_RLOCK(&V_tcbinfo); 1975 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1976 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1977 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 1978 /* signal EHOSTDOWN, as it flushes the cached route */ 1979 inp = (*notify)(inp, EHOSTDOWN); 1980 goto out; 1981 } 1982 icmp_tcp_seq = th->th_seq; 1983 if (inp != NULL) { 1984 if (!(inp->inp_flags & INP_TIMEWAIT) && 1985 !(inp->inp_flags & INP_DROPPED) && 1986 !(inp->inp_socket == NULL)) { 1987 tp = intotcpcb(inp); 1988 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 1989 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 1990 if (cmd == PRC_MSGSIZE) { 1991 /* 1992 * MTU discovery: 1993 * If we got a needfrag set the MTU 1994 * in the route to the suggested new 1995 * value (if given) and then notify. 1996 */ 1997 mtu = ntohs(icp->icmp_nextmtu); 1998 /* 1999 * If no alternative MTU was 2000 * proposed, try the next smaller 2001 * one. 2002 */ 2003 if (!mtu) 2004 mtu = ip_next_mtu( 2005 ntohs(ip->ip_len), 1); 2006 if (mtu < V_tcp_minmss + 2007 sizeof(struct tcpiphdr)) 2008 mtu = V_tcp_minmss + 2009 sizeof(struct tcpiphdr); 2010 /* 2011 * Only process the offered MTU if it 2012 * is smaller than the current one. 2013 */ 2014 if (mtu < tp->t_maxseg + 2015 sizeof(struct tcpiphdr)) { 2016 bzero(&inc, sizeof(inc)); 2017 inc.inc_faddr = faddr; 2018 inc.inc_fibnum = 2019 inp->inp_inc.inc_fibnum; 2020 tcp_hc_updatemtu(&inc, mtu); 2021 tcp_mtudisc(inp, mtu); 2022 } 2023 } else 2024 inp = (*notify)(inp, 2025 inetctlerrmap[cmd]); 2026 } 2027 } 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, icmp_tcp_seq); 2035 } 2036out: 2037 if (inp != NULL) 2038 INP_WUNLOCK(inp); 2039 INP_INFO_RUNLOCK(&V_tcbinfo); 2040} 2041#endif /* INET */ 2042 2043#ifdef INET6 2044void 2045tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2046{ 2047 struct in6_addr *dst; 2048 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2049 struct ip6_hdr *ip6; 2050 struct mbuf *m; 2051 struct inpcb *inp; 2052 struct tcpcb *tp; 2053 struct icmp6_hdr *icmp6; 2054 struct ip6ctlparam *ip6cp = NULL; 2055 const struct sockaddr_in6 *sa6_src = NULL; 2056 struct in_conninfo inc; 2057 struct tcp_ports { 2058 uint16_t th_sport; 2059 uint16_t th_dport; 2060 } t_ports; 2061 tcp_seq icmp_tcp_seq; 2062 unsigned int mtu; 2063 unsigned int off; 2064 2065 if (sa->sa_family != AF_INET6 || 2066 sa->sa_len != sizeof(struct sockaddr_in6)) 2067 return; 2068 2069 /* if the parameter is from icmp6, decode it. */ 2070 if (d != NULL) { 2071 ip6cp = (struct ip6ctlparam *)d; 2072 icmp6 = ip6cp->ip6c_icmp6; 2073 m = ip6cp->ip6c_m; 2074 ip6 = ip6cp->ip6c_ip6; 2075 off = ip6cp->ip6c_off; 2076 sa6_src = ip6cp->ip6c_src; 2077 dst = ip6cp->ip6c_finaldst; 2078 } else { 2079 m = NULL; 2080 ip6 = NULL; 2081 off = 0; /* fool gcc */ 2082 sa6_src = &sa6_any; 2083 dst = NULL; 2084 } 2085 2086 if (cmd == PRC_MSGSIZE) 2087 notify = tcp_mtudisc_notify; 2088 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2089 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2090 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2091 notify = tcp_drop_syn_sent; 2092 2093 /* 2094 * Hostdead is ugly because it goes linearly through all PCBs. 2095 * XXX: We never get this from ICMP, otherwise it makes an 2096 * excellent DoS attack on machines with many connections. 2097 */ 2098 else if (cmd == PRC_HOSTDEAD) 2099 ip6 = NULL; 2100 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2101 return; 2102 2103 if (ip6 == NULL) { 2104 in6_pcbnotify(&V_tcbinfo, sa, 0, 2105 (const struct sockaddr *)sa6_src, 2106 0, cmd, NULL, notify); 2107 return; 2108 } 2109 2110 /* Check if we can safely get the ports from the tcp hdr */ 2111 if (m == NULL || 2112 (m->m_pkthdr.len < 2113 (int32_t) (off + sizeof(struct tcp_ports)))) { 2114 return; 2115 } 2116 bzero(&t_ports, sizeof(struct tcp_ports)); 2117 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2118 INP_INFO_RLOCK(&V_tcbinfo); 2119 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2120 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2121 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2122 /* signal EHOSTDOWN, as it flushes the cached route */ 2123 inp = (*notify)(inp, EHOSTDOWN); 2124 goto out; 2125 } 2126 off += sizeof(struct tcp_ports); 2127 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2128 goto out; 2129 } 2130 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2131 if (inp != NULL) { 2132 if (!(inp->inp_flags & INP_TIMEWAIT) && 2133 !(inp->inp_flags & INP_DROPPED) && 2134 !(inp->inp_socket == NULL)) { 2135 tp = intotcpcb(inp); 2136 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2137 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2138 if (cmd == PRC_MSGSIZE) { 2139 /* 2140 * MTU discovery: 2141 * If we got a needfrag set the MTU 2142 * in the route to the suggested new 2143 * value (if given) and then notify. 2144 */ 2145 mtu = ntohl(icmp6->icmp6_mtu); 2146 /* 2147 * If no alternative MTU was 2148 * proposed, or the proposed 2149 * MTU was too small, set to 2150 * the min. 2151 */ 2152 if (mtu < IPV6_MMTU) 2153 mtu = IPV6_MMTU - 8; 2154 bzero(&inc, sizeof(inc)); 2155 inc.inc_fibnum = M_GETFIB(m); 2156 inc.inc_flags |= INC_ISIPV6; 2157 inc.inc6_faddr = *dst; 2158 if (in6_setscope(&inc.inc6_faddr, 2159 m->m_pkthdr.rcvif, NULL)) 2160 goto out; 2161 /* 2162 * Only process the offered MTU if it 2163 * is smaller than the current one. 2164 */ 2165 if (mtu < tp->t_maxseg + 2166 sizeof (struct tcphdr) + 2167 sizeof (struct ip6_hdr)) { 2168 tcp_hc_updatemtu(&inc, mtu); 2169 tcp_mtudisc(inp, mtu); 2170 ICMP6STAT_INC(icp6s_pmtuchg); 2171 } 2172 } else 2173 inp = (*notify)(inp, 2174 inet6ctlerrmap[cmd]); 2175 } 2176 } 2177 } else { 2178 bzero(&inc, sizeof(inc)); 2179 inc.inc_fibnum = M_GETFIB(m); 2180 inc.inc_flags |= INC_ISIPV6; 2181 inc.inc_fport = t_ports.th_dport; 2182 inc.inc_lport = t_ports.th_sport; 2183 inc.inc6_faddr = *dst; 2184 inc.inc6_laddr = ip6->ip6_src; 2185 syncache_unreach(&inc, icmp_tcp_seq); 2186 } 2187out: 2188 if (inp != NULL) 2189 INP_WUNLOCK(inp); 2190 INP_INFO_RUNLOCK(&V_tcbinfo); 2191} 2192#endif /* INET6 */ 2193 2194static uint32_t 2195tcp_keyed_hash(struct in_conninfo *inc, u_char *key) 2196{ 2197 MD5_CTX ctx; 2198 uint32_t hash[4]; 2199 2200 MD5Init(&ctx); 2201 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2202 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2203 switch (inc->inc_flags & INC_ISIPV6) { 2204#ifdef INET 2205 case 0: 2206 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2207 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2208 break; 2209#endif 2210#ifdef INET6 2211 case INC_ISIPV6: 2212 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2213 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2214 break; 2215#endif 2216 } 2217 MD5Update(&ctx, key, 32); 2218 MD5Final((unsigned char *)hash, &ctx); 2219 2220 return (hash[0]); 2221} 2222 2223uint32_t 2224tcp_new_ts_offset(struct in_conninfo *inc) 2225{ 2226 return (tcp_keyed_hash(inc, V_ts_offset_secret)); 2227} 2228 2229/* 2230 * Following is where TCP initial sequence number generation occurs. 2231 * 2232 * There are two places where we must use initial sequence numbers: 2233 * 1. In SYN-ACK packets. 2234 * 2. In SYN packets. 2235 * 2236 * All ISNs for SYN-ACK packets are generated by the syncache. See 2237 * tcp_syncache.c for details. 2238 * 2239 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2240 * depends on this property. In addition, these ISNs should be 2241 * unguessable so as to prevent connection hijacking. To satisfy 2242 * the requirements of this situation, the algorithm outlined in 2243 * RFC 1948 is used, with only small modifications. 2244 * 2245 * Implementation details: 2246 * 2247 * Time is based off the system timer, and is corrected so that it 2248 * increases by one megabyte per second. This allows for proper 2249 * recycling on high speed LANs while still leaving over an hour 2250 * before rollover. 2251 * 2252 * As reading the *exact* system time is too expensive to be done 2253 * whenever setting up a TCP connection, we increment the time 2254 * offset in two ways. First, a small random positive increment 2255 * is added to isn_offset for each connection that is set up. 2256 * Second, the function tcp_isn_tick fires once per clock tick 2257 * and increments isn_offset as necessary so that sequence numbers 2258 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2259 * random positive increments serve only to ensure that the same 2260 * exact sequence number is never sent out twice (as could otherwise 2261 * happen when a port is recycled in less than the system tick 2262 * interval.) 2263 * 2264 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2265 * between seeding of isn_secret. This is normally set to zero, 2266 * as reseeding should not be necessary. 2267 * 2268 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2269 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2270 * general, this means holding an exclusive (write) lock. 2271 */ 2272 2273#define ISN_BYTES_PER_SECOND 1048576 2274#define ISN_STATIC_INCREMENT 4096 2275#define ISN_RANDOM_INCREMENT (4096 - 1) 2276 2277static VNET_DEFINE(u_char, isn_secret[32]); 2278static VNET_DEFINE(int, isn_last); 2279static VNET_DEFINE(int, isn_last_reseed); 2280static VNET_DEFINE(u_int32_t, isn_offset); 2281static VNET_DEFINE(u_int32_t, isn_offset_old); 2282 2283#define V_isn_secret VNET(isn_secret) 2284#define V_isn_last VNET(isn_last) 2285#define V_isn_last_reseed VNET(isn_last_reseed) 2286#define V_isn_offset VNET(isn_offset) 2287#define V_isn_offset_old VNET(isn_offset_old) 2288 2289tcp_seq 2290tcp_new_isn(struct in_conninfo *inc) 2291{ 2292 tcp_seq new_isn; 2293 u_int32_t projected_offset; 2294 2295 ISN_LOCK(); 2296 /* Seed if this is the first use, reseed if requested. */ 2297 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2298 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2299 < (u_int)ticks))) { 2300 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2301 V_isn_last_reseed = ticks; 2302 } 2303 2304 /* Compute the md5 hash and return the ISN. */ 2305 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret); 2306 V_isn_offset += ISN_STATIC_INCREMENT + 2307 (arc4random() & ISN_RANDOM_INCREMENT); 2308 if (ticks != V_isn_last) { 2309 projected_offset = V_isn_offset_old + 2310 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2311 if (SEQ_GT(projected_offset, V_isn_offset)) 2312 V_isn_offset = projected_offset; 2313 V_isn_offset_old = V_isn_offset; 2314 V_isn_last = ticks; 2315 } 2316 new_isn += V_isn_offset; 2317 ISN_UNLOCK(); 2318 return (new_isn); 2319} 2320 2321/* 2322 * When a specific ICMP unreachable message is received and the 2323 * connection state is SYN-SENT, drop the connection. This behavior 2324 * is controlled by the icmp_may_rst sysctl. 2325 */ 2326struct inpcb * 2327tcp_drop_syn_sent(struct inpcb *inp, int errno) 2328{ 2329 struct tcpcb *tp; 2330 2331 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2332 INP_WLOCK_ASSERT(inp); 2333 2334 if ((inp->inp_flags & INP_TIMEWAIT) || 2335 (inp->inp_flags & INP_DROPPED)) 2336 return (inp); 2337 2338 tp = intotcpcb(inp); 2339 if (tp->t_state != TCPS_SYN_SENT) 2340 return (inp); 2341 2342 tp = tcp_drop(tp, errno); 2343 if (tp != NULL) 2344 return (inp); 2345 else 2346 return (NULL); 2347} 2348 2349/* 2350 * When `need fragmentation' ICMP is received, update our idea of the MSS 2351 * based on the new value. Also nudge TCP to send something, since we 2352 * know the packet we just sent was dropped. 2353 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2354 */ 2355static struct inpcb * 2356tcp_mtudisc_notify(struct inpcb *inp, int error) 2357{ 2358 2359 tcp_mtudisc(inp, -1); 2360 return (inp); 2361} 2362 2363static void 2364tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2365{ 2366 struct tcpcb *tp; 2367 struct socket *so; 2368 2369 INP_WLOCK_ASSERT(inp); 2370 if ((inp->inp_flags & INP_TIMEWAIT) || 2371 (inp->inp_flags & INP_DROPPED)) 2372 return; 2373 2374 tp = intotcpcb(inp); 2375 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2376 2377 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2378 2379 so = inp->inp_socket; 2380 SOCKBUF_LOCK(&so->so_snd); 2381 /* If the mss is larger than the socket buffer, decrease the mss. */ 2382 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2383 tp->t_maxseg = so->so_snd.sb_hiwat; 2384 SOCKBUF_UNLOCK(&so->so_snd); 2385 2386 TCPSTAT_INC(tcps_mturesent); 2387 tp->t_rtttime = 0; 2388 tp->snd_nxt = tp->snd_una; 2389 tcp_free_sackholes(tp); 2390 tp->snd_recover = tp->snd_max; 2391 if (tp->t_flags & TF_SACK_PERMIT) 2392 EXIT_FASTRECOVERY(tp->t_flags); 2393 tp->t_fb->tfb_tcp_output(tp); 2394} 2395 2396#ifdef INET 2397/* 2398 * Look-up the routing entry to the peer of this inpcb. If no route 2399 * is found and it cannot be allocated, then return 0. This routine 2400 * is called by TCP routines that access the rmx structure and by 2401 * tcp_mss_update to get the peer/interface MTU. 2402 */ 2403u_long 2404tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2405{ 2406 struct nhop4_extended nh4; 2407 struct ifnet *ifp; 2408 u_long maxmtu = 0; 2409 2410 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2411 2412 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2413 2414 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2415 NHR_REF, 0, &nh4) != 0) 2416 return (0); 2417 2418 ifp = nh4.nh_ifp; 2419 maxmtu = nh4.nh_mtu; 2420 2421 /* Report additional interface capabilities. */ 2422 if (cap != NULL) { 2423 if (ifp->if_capenable & IFCAP_TSO4 && 2424 ifp->if_hwassist & CSUM_TSO) { 2425 cap->ifcap |= CSUM_TSO; 2426 cap->tsomax = ifp->if_hw_tsomax; 2427 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2428 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2429 } 2430 } 2431 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2432 } 2433 return (maxmtu); 2434} 2435#endif /* INET */ 2436 2437#ifdef INET6 2438u_long 2439tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2440{ 2441 struct nhop6_extended nh6; 2442 struct in6_addr dst6; 2443 uint32_t scopeid; 2444 struct ifnet *ifp; 2445 u_long maxmtu = 0; 2446 2447 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2448 2449 if (inc->inc_flags & INC_IPV6MINMTU) 2450 return (IPV6_MMTU); 2451 2452 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2453 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2454 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2455 0, &nh6) != 0) 2456 return (0); 2457 2458 ifp = nh6.nh_ifp; 2459 maxmtu = nh6.nh_mtu; 2460 2461 /* Report additional interface capabilities. */ 2462 if (cap != NULL) { 2463 if (ifp->if_capenable & IFCAP_TSO6 && 2464 ifp->if_hwassist & CSUM_TSO) { 2465 cap->ifcap |= CSUM_TSO; 2466 cap->tsomax = ifp->if_hw_tsomax; 2467 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2468 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2469 } 2470 } 2471 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2472 } 2473 2474 return (maxmtu); 2475} 2476#endif /* INET6 */ 2477 2478/* 2479 * Calculate effective SMSS per RFC5681 definition for a given TCP 2480 * connection at its current state, taking into account SACK and etc. 2481 */ 2482u_int 2483tcp_maxseg(const struct tcpcb *tp) 2484{ 2485 u_int optlen; 2486 2487 if (tp->t_flags & TF_NOOPT) 2488 return (tp->t_maxseg); 2489 2490 /* 2491 * Here we have a simplified code from tcp_addoptions(), 2492 * without a proper loop, and having most of paddings hardcoded. 2493 * We might make mistakes with padding here in some edge cases, 2494 * but this is harmless, since result of tcp_maxseg() is used 2495 * only in cwnd and ssthresh estimations. 2496 */ 2497#define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2498 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2499 if (tp->t_flags & TF_RCVD_TSTMP) 2500 optlen = TCPOLEN_TSTAMP_APPA; 2501 else 2502 optlen = 0; 2503#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2504 if (tp->t_flags & TF_SIGNATURE) 2505 optlen += PAD(TCPOLEN_SIGNATURE); 2506#endif 2507 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2508 optlen += TCPOLEN_SACKHDR; 2509 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2510 optlen = PAD(optlen); 2511 } 2512 } else { 2513 if (tp->t_flags & TF_REQ_TSTMP) 2514 optlen = TCPOLEN_TSTAMP_APPA; 2515 else 2516 optlen = PAD(TCPOLEN_MAXSEG); 2517 if (tp->t_flags & TF_REQ_SCALE) 2518 optlen += PAD(TCPOLEN_WINDOW); 2519#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2520 if (tp->t_flags & TF_SIGNATURE) 2521 optlen += PAD(TCPOLEN_SIGNATURE); 2522#endif 2523 if (tp->t_flags & TF_SACK_PERMIT) 2524 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2525 } 2526#undef PAD 2527 optlen = min(optlen, TCP_MAXOLEN); 2528 return (tp->t_maxseg - optlen); 2529} 2530 2531static int 2532sysctl_drop(SYSCTL_HANDLER_ARGS) 2533{ 2534 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2535 struct sockaddr_storage addrs[2]; 2536 struct inpcb *inp; 2537 struct tcpcb *tp; 2538 struct tcptw *tw; 2539 struct sockaddr_in *fin, *lin; 2540#ifdef INET6 2541 struct sockaddr_in6 *fin6, *lin6; 2542#endif 2543 int error; 2544 2545 inp = NULL; 2546 fin = lin = NULL; 2547#ifdef INET6 2548 fin6 = lin6 = NULL; 2549#endif 2550 error = 0; 2551 2552 if (req->oldptr != NULL || req->oldlen != 0) 2553 return (EINVAL); 2554 if (req->newptr == NULL) 2555 return (EPERM); 2556 if (req->newlen < sizeof(addrs)) 2557 return (ENOMEM); 2558 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2559 if (error) 2560 return (error); 2561 2562 switch (addrs[0].ss_family) { 2563#ifdef INET6 2564 case AF_INET6: 2565 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2566 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2567 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2568 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2569 return (EINVAL); 2570 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2571 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2572 return (EINVAL); 2573 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2574 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2575 fin = (struct sockaddr_in *)&addrs[0]; 2576 lin = (struct sockaddr_in *)&addrs[1]; 2577 break; 2578 } 2579 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2580 if (error) 2581 return (error); 2582 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2583 if (error) 2584 return (error); 2585 break; 2586#endif 2587#ifdef INET 2588 case AF_INET: 2589 fin = (struct sockaddr_in *)&addrs[0]; 2590 lin = (struct sockaddr_in *)&addrs[1]; 2591 if (fin->sin_len != sizeof(struct sockaddr_in) || 2592 lin->sin_len != sizeof(struct sockaddr_in)) 2593 return (EINVAL); 2594 break; 2595#endif 2596 default: 2597 return (EINVAL); 2598 } 2599 INP_INFO_RLOCK(&V_tcbinfo); 2600 switch (addrs[0].ss_family) { 2601#ifdef INET6 2602 case AF_INET6: 2603 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2604 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2605 INPLOOKUP_WLOCKPCB, NULL); 2606 break; 2607#endif 2608#ifdef INET 2609 case AF_INET: 2610 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2611 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2612 break; 2613#endif 2614 } 2615 if (inp != NULL) { 2616 if (inp->inp_flags & INP_TIMEWAIT) { 2617 /* 2618 * XXXRW: There currently exists a state where an 2619 * inpcb is present, but its timewait state has been 2620 * discarded. For now, don't allow dropping of this 2621 * type of inpcb. 2622 */ 2623 tw = intotw(inp); 2624 if (tw != NULL) 2625 tcp_twclose(tw, 0); 2626 else 2627 INP_WUNLOCK(inp); 2628 } else if (!(inp->inp_flags & INP_DROPPED) && 2629 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2630 tp = intotcpcb(inp); 2631 tp = tcp_drop(tp, ECONNABORTED); 2632 if (tp != NULL) 2633 INP_WUNLOCK(inp); 2634 } else 2635 INP_WUNLOCK(inp); 2636 } else 2637 error = ESRCH; 2638 INP_INFO_RUNLOCK(&V_tcbinfo); 2639 return (error); 2640} 2641 2642SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2643 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2644 0, sysctl_drop, "", "Drop TCP connection"); 2645 2646/* 2647 * Generate a standardized TCP log line for use throughout the 2648 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2649 * allow use in the interrupt context. 2650 * 2651 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2652 * NB: The function may return NULL if memory allocation failed. 2653 * 2654 * Due to header inclusion and ordering limitations the struct ip 2655 * and ip6_hdr pointers have to be passed as void pointers. 2656 */ 2657char * 2658tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2659 const void *ip6hdr) 2660{ 2661 2662 /* Is logging enabled? */ 2663 if (tcp_log_in_vain == 0) 2664 return (NULL); 2665 2666 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2667} 2668 2669char * 2670tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2671 const void *ip6hdr) 2672{ 2673 2674 /* Is logging enabled? */ 2675 if (tcp_log_debug == 0) 2676 return (NULL); 2677 2678 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2679} 2680 2681static char * 2682tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2683 const void *ip6hdr) 2684{ 2685 char *s, *sp; 2686 size_t size; 2687 struct ip *ip; 2688#ifdef INET6 2689 const struct ip6_hdr *ip6; 2690 2691 ip6 = (const struct ip6_hdr *)ip6hdr; 2692#endif /* INET6 */ 2693 ip = (struct ip *)ip4hdr; 2694 2695 /* 2696 * The log line looks like this: 2697 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2698 */ 2699 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2700 sizeof(PRINT_TH_FLAGS) + 1 + 2701#ifdef INET6 2702 2 * INET6_ADDRSTRLEN; 2703#else 2704 2 * INET_ADDRSTRLEN; 2705#endif /* INET6 */ 2706 2707 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2708 if (s == NULL) 2709 return (NULL); 2710 2711 strcat(s, "TCP: ["); 2712 sp = s + strlen(s); 2713 2714 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2715 inet_ntoa_r(inc->inc_faddr, sp); 2716 sp = s + strlen(s); 2717 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2718 sp = s + strlen(s); 2719 inet_ntoa_r(inc->inc_laddr, sp); 2720 sp = s + strlen(s); 2721 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2722#ifdef INET6 2723 } else if (inc) { 2724 ip6_sprintf(sp, &inc->inc6_faddr); 2725 sp = s + strlen(s); 2726 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2727 sp = s + strlen(s); 2728 ip6_sprintf(sp, &inc->inc6_laddr); 2729 sp = s + strlen(s); 2730 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2731 } else if (ip6 && th) { 2732 ip6_sprintf(sp, &ip6->ip6_src); 2733 sp = s + strlen(s); 2734 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2735 sp = s + strlen(s); 2736 ip6_sprintf(sp, &ip6->ip6_dst); 2737 sp = s + strlen(s); 2738 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2739#endif /* INET6 */ 2740#ifdef INET 2741 } else if (ip && th) { 2742 inet_ntoa_r(ip->ip_src, sp); 2743 sp = s + strlen(s); 2744 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2745 sp = s + strlen(s); 2746 inet_ntoa_r(ip->ip_dst, sp); 2747 sp = s + strlen(s); 2748 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2749#endif /* INET */ 2750 } else { 2751 free(s, M_TCPLOG); 2752 return (NULL); 2753 } 2754 sp = s + strlen(s); 2755 if (th) 2756 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2757 if (*(s + size - 1) != '\0') 2758 panic("%s: string too long", __func__); 2759 return (s); 2760} 2761 2762/* 2763 * A subroutine which makes it easy to track TCP state changes with DTrace. 2764 * This function shouldn't be called for t_state initializations that don't 2765 * correspond to actual TCP state transitions. 2766 */ 2767void 2768tcp_state_change(struct tcpcb *tp, int newstate) 2769{ 2770#if defined(KDTRACE_HOOKS) 2771 int pstate = tp->t_state; 2772#endif 2773 2774 TCPSTATES_DEC(tp->t_state); 2775 TCPSTATES_INC(newstate); 2776 tp->t_state = newstate; 2777 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2778} 2779