1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_tcpdebug.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/callout.h> 45 #include <sys/eventhandler.h> 46 #ifdef TCP_HHOOK 47 #include <sys/hhook.h> 48 #endif 49 #include <sys/kernel.h> 50 #ifdef TCP_HHOOK 51 #include <sys/khelp.h> 52 #endif 53 #include <sys/sysctl.h> 54 #include <sys/jail.h> 55 #include <sys/malloc.h> 56 #include <sys/refcount.h> 57 #include <sys/mbuf.h> 58 #ifdef INET6 59 #include <sys/domain.h> 60 #endif 61 #include <sys/priv.h> 62 #include <sys/proc.h> 63 #include <sys/sdt.h> 64 #include <sys/socket.h> 65 #include <sys/socketvar.h> 66 #include <sys/protosw.h> 67 #include <sys/random.h> 68 69 #include <vm/uma.h> 70 71 #include <net/route.h> 72 #include <net/if.h> 73 #include <net/if_var.h> 74 #include <net/vnet.h> 75 76 #include <netinet/in.h> 77 #include <netinet/in_fib.h> 78 #include <netinet/in_kdtrace.h> 79 #include <netinet/in_pcb.h> 80 #include <netinet/in_systm.h> 81 #include <netinet/in_var.h> 82 #include <netinet/ip.h> 83 #include <netinet/ip_icmp.h> 84 #include <netinet/ip_var.h> 85 #ifdef INET6 86 #include <netinet/icmp6.h> 87 #include <netinet/ip6.h> 88 #include <netinet6/in6_fib.h> 89 #include <netinet6/in6_pcb.h> 90 #include <netinet6/ip6_var.h> 91 #include <netinet6/scope6_var.h> 92 #include <netinet6/nd6.h> 93 #endif 94 95 #include <netinet/tcp.h> 96 #include <netinet/tcp_fsm.h> 97 #include <netinet/tcp_seq.h> 98 #include <netinet/tcp_timer.h> 99 #include <netinet/tcp_var.h> 100 #include <netinet/tcp_log_buf.h> 101 #include <netinet/tcp_syncache.h> 102 #include <netinet/tcp_hpts.h> 103 #include <netinet/cc/cc.h> 104 #ifdef INET6 105 #include <netinet6/tcp6_var.h> 106 #endif 107 #include <netinet/tcpip.h> 108 #include <netinet/tcp_fastopen.h> 109 #ifdef TCPPCAP 110 #include <netinet/tcp_pcap.h> 111 #endif 112 #ifdef TCPDEBUG 113 #include <netinet/tcp_debug.h> 114 #endif 115 #ifdef INET6 116 #include <netinet6/ip6protosw.h> 117 #endif 118 #ifdef TCP_OFFLOAD 119 #include <netinet/tcp_offload.h> 120 #endif 121 122 #include <netipsec/ipsec_support.h> 123 124 #include <machine/in_cksum.h> 125 #include <sys/md5.h> 126 127 #include <security/mac/mac_framework.h> 128 129 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 130 #ifdef INET6 131 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 132 #endif 133 134 struct rwlock tcp_function_lock; 135 136 static int 137 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 138 { 139 int error, new; 140 141 new = V_tcp_mssdflt; 142 error = sysctl_handle_int(oidp, &new, 0, req); 143 if (error == 0 && req->newptr) { 144 if (new < TCP_MINMSS) 145 error = EINVAL; 146 else 147 V_tcp_mssdflt = new; 148 } 149 return (error); 150 } 151 152 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 153 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 154 &sysctl_net_inet_tcp_mss_check, "I", 155 "Default TCP Maximum Segment Size"); 156 157 #ifdef INET6 158 static int 159 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 160 { 161 int error, new; 162 163 new = V_tcp_v6mssdflt; 164 error = sysctl_handle_int(oidp, &new, 0, req); 165 if (error == 0 && req->newptr) { 166 if (new < TCP_MINMSS) 167 error = EINVAL; 168 else 169 V_tcp_v6mssdflt = new; 170 } 171 return (error); 172 } 173 174 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 175 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 176 &sysctl_net_inet_tcp_mss_v6_check, "I", 177 "Default TCP Maximum Segment Size for IPv6"); 178 #endif /* INET6 */ 179 180 /* 181 * Minimum MSS we accept and use. This prevents DoS attacks where 182 * we are forced to a ridiculous low MSS like 20 and send hundreds 183 * of packets instead of one. The effect scales with the available 184 * bandwidth and quickly saturates the CPU and network interface 185 * with packet generation and sending. Set to zero to disable MINMSS 186 * checking. This setting prevents us from sending too small packets. 187 */ 188 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 190 &VNET_NAME(tcp_minmss), 0, 191 "Minimum TCP Maximum Segment Size"); 192 193 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 194 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 195 &VNET_NAME(tcp_do_rfc1323), 0, 196 "Enable rfc1323 (high performance TCP) extensions"); 197 198 static int tcp_log_debug = 0; 199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 200 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 201 202 static int tcp_tcbhashsize; 203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 204 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 205 206 static int do_tcpdrain = 1; 207 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 208 "Enable tcp_drain routine for extra help when low on mbufs"); 209 210 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 211 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 212 213 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 214 #define V_icmp_may_rst VNET(icmp_may_rst) 215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 216 &VNET_NAME(icmp_may_rst), 0, 217 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 218 219 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 220 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 221 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 222 &VNET_NAME(tcp_isn_reseed_interval), 0, 223 "Seconds between reseeding of ISN secret"); 224 225 static int tcp_soreceive_stream; 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 227 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 228 229 VNET_DEFINE(uma_zone_t, sack_hole_zone); 230 #define V_sack_hole_zone VNET(sack_hole_zone) 231 232 #ifdef TCP_HHOOK 233 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 234 #endif 235 236 #define TS_OFFSET_SECRET_LENGTH 32 237 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 238 #define V_ts_offset_secret VNET(ts_offset_secret) 239 240 static int tcp_default_fb_init(struct tcpcb *tp); 241 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 242 static int tcp_default_handoff_ok(struct tcpcb *tp); 243 static struct inpcb *tcp_notify(struct inpcb *, int); 244 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 245 static void tcp_mtudisc(struct inpcb *, int); 246 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 247 void *ip4hdr, const void *ip6hdr); 248 249 250 static struct tcp_function_block tcp_def_funcblk = { 251 .tfb_tcp_block_name = "freebsd", 252 .tfb_tcp_output = tcp_output, 253 .tfb_tcp_do_segment = tcp_do_segment, 254 .tfb_tcp_ctloutput = tcp_default_ctloutput, 255 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 256 .tfb_tcp_fb_init = tcp_default_fb_init, 257 .tfb_tcp_fb_fini = tcp_default_fb_fini, 258 }; 259 260 static int tcp_fb_cnt = 0; 261 struct tcp_funchead t_functions; 262 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 263 264 static struct tcp_function_block * 265 find_tcp_functions_locked(struct tcp_function_set *fs) 266 { 267 struct tcp_function *f; 268 struct tcp_function_block *blk=NULL; 269 270 TAILQ_FOREACH(f, &t_functions, tf_next) { 271 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 272 blk = f->tf_fb; 273 break; 274 } 275 } 276 return(blk); 277 } 278 279 static struct tcp_function_block * 280 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 281 { 282 struct tcp_function_block *rblk=NULL; 283 struct tcp_function *f; 284 285 TAILQ_FOREACH(f, &t_functions, tf_next) { 286 if (f->tf_fb == blk) { 287 rblk = blk; 288 if (s) { 289 *s = f; 290 } 291 break; 292 } 293 } 294 return (rblk); 295 } 296 297 struct tcp_function_block * 298 find_and_ref_tcp_functions(struct tcp_function_set *fs) 299 { 300 struct tcp_function_block *blk; 301 302 rw_rlock(&tcp_function_lock); 303 blk = find_tcp_functions_locked(fs); 304 if (blk) 305 refcount_acquire(&blk->tfb_refcnt); 306 rw_runlock(&tcp_function_lock); 307 return(blk); 308 } 309 310 struct tcp_function_block * 311 find_and_ref_tcp_fb(struct tcp_function_block *blk) 312 { 313 struct tcp_function_block *rblk; 314 315 rw_rlock(&tcp_function_lock); 316 rblk = find_tcp_fb_locked(blk, NULL); 317 if (rblk) 318 refcount_acquire(&rblk->tfb_refcnt); 319 rw_runlock(&tcp_function_lock); 320 return(rblk); 321 } 322 323 static struct tcp_function_block * 324 find_and_ref_tcp_default_fb(void) 325 { 326 struct tcp_function_block *rblk; 327 328 rw_rlock(&tcp_function_lock); 329 rblk = tcp_func_set_ptr; 330 refcount_acquire(&rblk->tfb_refcnt); 331 rw_runlock(&tcp_function_lock); 332 return (rblk); 333 } 334 335 void 336 tcp_switch_back_to_default(struct tcpcb *tp) 337 { 338 struct tcp_function_block *tfb; 339 340 KASSERT(tp->t_fb != &tcp_def_funcblk, 341 ("%s: called by the built-in default stack", __func__)); 342 343 /* 344 * Release the old stack. This function will either find a new one 345 * or panic. 346 */ 347 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 348 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 349 refcount_release(&tp->t_fb->tfb_refcnt); 350 351 /* 352 * Now, we'll find a new function block to use. 353 * Start by trying the current user-selected 354 * default, unless this stack is the user-selected 355 * default. 356 */ 357 tfb = find_and_ref_tcp_default_fb(); 358 if (tfb == tp->t_fb) { 359 refcount_release(&tfb->tfb_refcnt); 360 tfb = NULL; 361 } 362 /* Does the stack accept this connection? */ 363 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 364 (*tfb->tfb_tcp_handoff_ok)(tp)) { 365 refcount_release(&tfb->tfb_refcnt); 366 tfb = NULL; 367 } 368 /* Try to use that stack. */ 369 if (tfb != NULL) { 370 /* Initialize the new stack. If it succeeds, we are done. */ 371 tp->t_fb = tfb; 372 if (tp->t_fb->tfb_tcp_fb_init == NULL || 373 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 374 return; 375 376 /* 377 * Initialization failed. Release the reference count on 378 * the stack. 379 */ 380 refcount_release(&tfb->tfb_refcnt); 381 } 382 383 /* 384 * If that wasn't feasible, use the built-in default 385 * stack which is not allowed to reject anyone. 386 */ 387 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 388 if (tfb == NULL) { 389 /* there always should be a default */ 390 panic("Can't refer to tcp_def_funcblk"); 391 } 392 if (tfb->tfb_tcp_handoff_ok != NULL) { 393 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 394 /* The default stack cannot say no */ 395 panic("Default stack rejects a new session?"); 396 } 397 } 398 tp->t_fb = tfb; 399 if (tp->t_fb->tfb_tcp_fb_init != NULL && 400 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 401 /* The default stack cannot fail */ 402 panic("Default stack initialization failed"); 403 } 404 } 405 406 static int 407 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 408 { 409 int error=ENOENT; 410 struct tcp_function_set fs; 411 struct tcp_function_block *blk; 412 413 memset(&fs, 0, sizeof(fs)); 414 rw_rlock(&tcp_function_lock); 415 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 416 if (blk) { 417 /* Found him */ 418 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 419 fs.pcbcnt = blk->tfb_refcnt; 420 } 421 rw_runlock(&tcp_function_lock); 422 error = sysctl_handle_string(oidp, fs.function_set_name, 423 sizeof(fs.function_set_name), req); 424 425 /* Check for error or no change */ 426 if (error != 0 || req->newptr == NULL) 427 return(error); 428 429 rw_wlock(&tcp_function_lock); 430 blk = find_tcp_functions_locked(&fs); 431 if ((blk == NULL) || 432 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 433 error = ENOENT; 434 goto done; 435 } 436 tcp_func_set_ptr = blk; 437 done: 438 rw_wunlock(&tcp_function_lock); 439 return (error); 440 } 441 442 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 443 CTLTYPE_STRING | CTLFLAG_RW, 444 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 445 "Set/get the default TCP functions"); 446 447 static int 448 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 449 { 450 int error, cnt, linesz; 451 struct tcp_function *f; 452 char *buffer, *cp; 453 size_t bufsz, outsz; 454 bool alias; 455 456 cnt = 0; 457 rw_rlock(&tcp_function_lock); 458 TAILQ_FOREACH(f, &t_functions, tf_next) { 459 cnt++; 460 } 461 rw_runlock(&tcp_function_lock); 462 463 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 464 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 465 466 error = 0; 467 cp = buffer; 468 469 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 470 "Alias", "PCB count"); 471 cp += linesz; 472 bufsz -= linesz; 473 outsz = linesz; 474 475 rw_rlock(&tcp_function_lock); 476 TAILQ_FOREACH(f, &t_functions, tf_next) { 477 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 478 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 479 f->tf_fb->tfb_tcp_block_name, 480 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 481 alias ? f->tf_name : "-", 482 f->tf_fb->tfb_refcnt); 483 if (linesz >= bufsz) { 484 error = EOVERFLOW; 485 break; 486 } 487 cp += linesz; 488 bufsz -= linesz; 489 outsz += linesz; 490 } 491 rw_runlock(&tcp_function_lock); 492 if (error == 0) 493 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 494 free(buffer, M_TEMP); 495 return (error); 496 } 497 498 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 499 CTLTYPE_STRING|CTLFLAG_RD, 500 NULL, 0, sysctl_net_inet_list_available, "A", 501 "list available TCP Function sets"); 502 503 /* 504 * Exports one (struct tcp_function_info) for each alias/name. 505 */ 506 static int 507 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 508 { 509 int cnt, error; 510 struct tcp_function *f; 511 struct tcp_function_info tfi; 512 513 /* 514 * We don't allow writes. 515 */ 516 if (req->newptr != NULL) 517 return (EINVAL); 518 519 /* 520 * Wire the old buffer so we can directly copy the functions to 521 * user space without dropping the lock. 522 */ 523 if (req->oldptr != NULL) { 524 error = sysctl_wire_old_buffer(req, 0); 525 if (error) 526 return (error); 527 } 528 529 /* 530 * Walk the list and copy out matching entries. If INVARIANTS 531 * is compiled in, also walk the list to verify the length of 532 * the list matches what we have recorded. 533 */ 534 rw_rlock(&tcp_function_lock); 535 536 cnt = 0; 537 #ifndef INVARIANTS 538 if (req->oldptr == NULL) { 539 cnt = tcp_fb_cnt; 540 goto skip_loop; 541 } 542 #endif 543 TAILQ_FOREACH(f, &t_functions, tf_next) { 544 #ifdef INVARIANTS 545 cnt++; 546 #endif 547 if (req->oldptr != NULL) { 548 bzero(&tfi, sizeof(tfi)); 549 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 550 tfi.tfi_id = f->tf_fb->tfb_id; 551 (void)strlcpy(tfi.tfi_alias, f->tf_name, 552 sizeof(tfi.tfi_alias)); 553 (void)strlcpy(tfi.tfi_name, 554 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 555 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 556 /* 557 * Don't stop on error, as that is the 558 * mechanism we use to accumulate length 559 * information if the buffer was too short. 560 */ 561 } 562 } 563 KASSERT(cnt == tcp_fb_cnt, 564 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 565 #ifndef INVARIANTS 566 skip_loop: 567 #endif 568 rw_runlock(&tcp_function_lock); 569 if (req->oldptr == NULL) 570 error = SYSCTL_OUT(req, NULL, 571 (cnt + 1) * sizeof(struct tcp_function_info)); 572 573 return (error); 574 } 575 576 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 577 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 578 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 579 "List TCP function block name-to-ID mappings"); 580 581 /* 582 * tfb_tcp_handoff_ok() function for the default stack. 583 * Note that we'll basically try to take all comers. 584 */ 585 static int 586 tcp_default_handoff_ok(struct tcpcb *tp) 587 { 588 589 return (0); 590 } 591 592 /* 593 * tfb_tcp_fb_init() function for the default stack. 594 * 595 * This handles making sure we have appropriate timers set if you are 596 * transitioning a socket that has some amount of setup done. 597 * 598 * The init() fuction from the default can *never* return non-zero i.e. 599 * it is required to always succeed since it is the stack of last resort! 600 */ 601 static int 602 tcp_default_fb_init(struct tcpcb *tp) 603 { 604 605 struct socket *so; 606 607 INP_WLOCK_ASSERT(tp->t_inpcb); 608 609 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 610 ("%s: connection %p in unexpected state %d", __func__, tp, 611 tp->t_state)); 612 613 /* 614 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 615 * know what to do for unexpected states (which includes TIME_WAIT). 616 */ 617 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 618 return (0); 619 620 /* 621 * Make sure some kind of transmission timer is set if there is 622 * outstanding data. 623 */ 624 so = tp->t_inpcb->inp_socket; 625 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 626 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 627 tcp_timer_active(tp, TT_PERSIST))) { 628 /* 629 * If the session has established and it looks like it should 630 * be in the persist state, set the persist timer. Otherwise, 631 * set the retransmit timer. 632 */ 633 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 634 (int32_t)(tp->snd_nxt - tp->snd_una) < 635 (int32_t)sbavail(&so->so_snd)) 636 tcp_setpersist(tp); 637 else 638 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 639 } 640 641 /* All non-embryonic sessions get a keepalive timer. */ 642 if (!tcp_timer_active(tp, TT_KEEP)) 643 tcp_timer_activate(tp, TT_KEEP, 644 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 645 TP_KEEPINIT(tp)); 646 647 return (0); 648 } 649 650 /* 651 * tfb_tcp_fb_fini() function for the default stack. 652 * 653 * This changes state as necessary (or prudent) to prepare for another stack 654 * to assume responsibility for the connection. 655 */ 656 static void 657 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 658 { 659 660 INP_WLOCK_ASSERT(tp->t_inpcb); 661 return; 662 } 663 664 /* 665 * Target size of TCP PCB hash tables. Must be a power of two. 666 * 667 * Note that this can be overridden by the kernel environment 668 * variable net.inet.tcp.tcbhashsize 669 */ 670 #ifndef TCBHASHSIZE 671 #define TCBHASHSIZE 0 672 #endif 673 674 /* 675 * XXX 676 * Callouts should be moved into struct tcp directly. They are currently 677 * separate because the tcpcb structure is exported to userland for sysctl 678 * parsing purposes, which do not know about callouts. 679 */ 680 struct tcpcb_mem { 681 struct tcpcb tcb; 682 struct tcp_timer tt; 683 struct cc_var ccv; 684 #ifdef TCP_HHOOK 685 struct osd osd; 686 #endif 687 }; 688 689 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 690 #define V_tcpcb_zone VNET(tcpcb_zone) 691 692 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 693 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 694 695 static struct mtx isn_mtx; 696 697 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 698 #define ISN_LOCK() mtx_lock(&isn_mtx) 699 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 700 701 /* 702 * TCP initialization. 703 */ 704 static void 705 tcp_zone_change(void *tag) 706 { 707 708 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 709 uma_zone_set_max(V_tcpcb_zone, maxsockets); 710 tcp_tw_zone_change(); 711 } 712 713 static int 714 tcp_inpcb_init(void *mem, int size, int flags) 715 { 716 struct inpcb *inp = mem; 717 718 INP_LOCK_INIT(inp, "inp", "tcpinp"); 719 return (0); 720 } 721 722 /* 723 * Take a value and get the next power of 2 that doesn't overflow. 724 * Used to size the tcp_inpcb hash buckets. 725 */ 726 static int 727 maketcp_hashsize(int size) 728 { 729 int hashsize; 730 731 /* 732 * auto tune. 733 * get the next power of 2 higher than maxsockets. 734 */ 735 hashsize = 1 << fls(size); 736 /* catch overflow, and just go one power of 2 smaller */ 737 if (hashsize < size) { 738 hashsize = 1 << (fls(size) - 1); 739 } 740 return (hashsize); 741 } 742 743 static volatile int next_tcp_stack_id = 1; 744 745 /* 746 * Register a TCP function block with the name provided in the names 747 * array. (Note that this function does NOT automatically register 748 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 749 * explicitly include blk->tfb_tcp_block_name in the list of names if 750 * you wish to register the stack with that name.) 751 * 752 * Either all name registrations will succeed or all will fail. If 753 * a name registration fails, the function will update the num_names 754 * argument to point to the array index of the name that encountered 755 * the failure. 756 * 757 * Returns 0 on success, or an error code on failure. 758 */ 759 int 760 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 761 const char *names[], int *num_names) 762 { 763 struct tcp_function *n; 764 struct tcp_function_set fs; 765 int error, i; 766 767 KASSERT(names != NULL && *num_names > 0, 768 ("%s: Called with 0-length name list", __func__)); 769 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 770 KASSERT(rw_initialized(&tcp_function_lock), 771 ("%s: called too early", __func__)); 772 773 if ((blk->tfb_tcp_output == NULL) || 774 (blk->tfb_tcp_do_segment == NULL) || 775 (blk->tfb_tcp_ctloutput == NULL) || 776 (strlen(blk->tfb_tcp_block_name) == 0)) { 777 /* 778 * These functions are required and you 779 * need a name. 780 */ 781 *num_names = 0; 782 return (EINVAL); 783 } 784 if (blk->tfb_tcp_timer_stop_all || 785 blk->tfb_tcp_timer_activate || 786 blk->tfb_tcp_timer_active || 787 blk->tfb_tcp_timer_stop) { 788 /* 789 * If you define one timer function you 790 * must have them all. 791 */ 792 if ((blk->tfb_tcp_timer_stop_all == NULL) || 793 (blk->tfb_tcp_timer_activate == NULL) || 794 (blk->tfb_tcp_timer_active == NULL) || 795 (blk->tfb_tcp_timer_stop == NULL)) { 796 *num_names = 0; 797 return (EINVAL); 798 } 799 } 800 801 refcount_init(&blk->tfb_refcnt, 0); 802 blk->tfb_flags = 0; 803 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 804 for (i = 0; i < *num_names; i++) { 805 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 806 if (n == NULL) { 807 error = ENOMEM; 808 goto cleanup; 809 } 810 n->tf_fb = blk; 811 812 (void)strlcpy(fs.function_set_name, names[i], 813 sizeof(fs.function_set_name)); 814 rw_wlock(&tcp_function_lock); 815 if (find_tcp_functions_locked(&fs) != NULL) { 816 /* Duplicate name space not allowed */ 817 rw_wunlock(&tcp_function_lock); 818 free(n, M_TCPFUNCTIONS); 819 error = EALREADY; 820 goto cleanup; 821 } 822 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 823 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 824 tcp_fb_cnt++; 825 rw_wunlock(&tcp_function_lock); 826 } 827 return(0); 828 829 cleanup: 830 /* 831 * Deregister the names we just added. Because registration failed 832 * for names[i], we don't need to deregister that name. 833 */ 834 *num_names = i; 835 rw_wlock(&tcp_function_lock); 836 while (--i >= 0) { 837 TAILQ_FOREACH(n, &t_functions, tf_next) { 838 if (!strncmp(n->tf_name, names[i], 839 TCP_FUNCTION_NAME_LEN_MAX)) { 840 TAILQ_REMOVE(&t_functions, n, tf_next); 841 tcp_fb_cnt--; 842 n->tf_fb = NULL; 843 free(n, M_TCPFUNCTIONS); 844 break; 845 } 846 } 847 } 848 rw_wunlock(&tcp_function_lock); 849 return (error); 850 } 851 852 /* 853 * Register a TCP function block using the name provided in the name 854 * argument. 855 * 856 * Returns 0 on success, or an error code on failure. 857 */ 858 int 859 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 860 int wait) 861 { 862 const char *name_list[1]; 863 int num_names, rv; 864 865 num_names = 1; 866 if (name != NULL) 867 name_list[0] = name; 868 else 869 name_list[0] = blk->tfb_tcp_block_name; 870 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 871 return (rv); 872 } 873 874 /* 875 * Register a TCP function block using the name defined in 876 * blk->tfb_tcp_block_name. 877 * 878 * Returns 0 on success, or an error code on failure. 879 */ 880 int 881 register_tcp_functions(struct tcp_function_block *blk, int wait) 882 { 883 884 return (register_tcp_functions_as_name(blk, NULL, wait)); 885 } 886 887 /* 888 * Deregister all names associated with a function block. This 889 * functionally removes the function block from use within the system. 890 * 891 * When called with a true quiesce argument, mark the function block 892 * as being removed so no more stacks will use it and determine 893 * whether the removal would succeed. 894 * 895 * When called with a false quiesce argument, actually attempt the 896 * removal. 897 * 898 * When called with a force argument, attempt to switch all TCBs to 899 * use the default stack instead of returning EBUSY. 900 * 901 * Returns 0 on success (or if the removal would succeed, or an error 902 * code on failure. 903 */ 904 int 905 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 906 bool force) 907 { 908 struct tcp_function *f; 909 910 if (blk == &tcp_def_funcblk) { 911 /* You can't un-register the default */ 912 return (EPERM); 913 } 914 rw_wlock(&tcp_function_lock); 915 if (blk == tcp_func_set_ptr) { 916 /* You can't free the current default */ 917 rw_wunlock(&tcp_function_lock); 918 return (EBUSY); 919 } 920 /* Mark the block so no more stacks can use it. */ 921 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 922 /* 923 * If TCBs are still attached to the stack, attempt to switch them 924 * to the default stack. 925 */ 926 if (force && blk->tfb_refcnt) { 927 struct inpcb *inp; 928 struct tcpcb *tp; 929 VNET_ITERATOR_DECL(vnet_iter); 930 931 rw_wunlock(&tcp_function_lock); 932 933 VNET_LIST_RLOCK(); 934 VNET_FOREACH(vnet_iter) { 935 CURVNET_SET(vnet_iter); 936 INP_INFO_WLOCK(&V_tcbinfo); 937 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 938 INP_WLOCK(inp); 939 if (inp->inp_flags & INP_TIMEWAIT) { 940 INP_WUNLOCK(inp); 941 continue; 942 } 943 tp = intotcpcb(inp); 944 if (tp == NULL || tp->t_fb != blk) { 945 INP_WUNLOCK(inp); 946 continue; 947 } 948 tcp_switch_back_to_default(tp); 949 INP_WUNLOCK(inp); 950 } 951 INP_INFO_WUNLOCK(&V_tcbinfo); 952 CURVNET_RESTORE(); 953 } 954 VNET_LIST_RUNLOCK(); 955 956 rw_wlock(&tcp_function_lock); 957 } 958 if (blk->tfb_refcnt) { 959 /* TCBs still attached. */ 960 rw_wunlock(&tcp_function_lock); 961 return (EBUSY); 962 } 963 if (quiesce) { 964 /* Skip removal. */ 965 rw_wunlock(&tcp_function_lock); 966 return (0); 967 } 968 /* Remove any function names that map to this function block. */ 969 while (find_tcp_fb_locked(blk, &f) != NULL) { 970 TAILQ_REMOVE(&t_functions, f, tf_next); 971 tcp_fb_cnt--; 972 f->tf_fb = NULL; 973 free(f, M_TCPFUNCTIONS); 974 } 975 rw_wunlock(&tcp_function_lock); 976 return (0); 977 } 978 979 void 980 tcp_init(void) 981 { 982 const char *tcbhash_tuneable; 983 int hashsize; 984 985 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 986 987 #ifdef TCP_HHOOK 988 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 989 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 990 printf("%s: WARNING: unable to register helper hook\n", __func__); 991 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 992 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 993 printf("%s: WARNING: unable to register helper hook\n", __func__); 994 #endif 995 hashsize = TCBHASHSIZE; 996 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 997 if (hashsize == 0) { 998 /* 999 * Auto tune the hash size based on maxsockets. 1000 * A perfect hash would have a 1:1 mapping 1001 * (hashsize = maxsockets) however it's been 1002 * suggested that O(2) average is better. 1003 */ 1004 hashsize = maketcp_hashsize(maxsockets / 4); 1005 /* 1006 * Our historical default is 512, 1007 * do not autotune lower than this. 1008 */ 1009 if (hashsize < 512) 1010 hashsize = 512; 1011 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1012 printf("%s: %s auto tuned to %d\n", __func__, 1013 tcbhash_tuneable, hashsize); 1014 } 1015 /* 1016 * We require a hashsize to be a power of two. 1017 * Previously if it was not a power of two we would just reset it 1018 * back to 512, which could be a nasty surprise if you did not notice 1019 * the error message. 1020 * Instead what we do is clip it to the closest power of two lower 1021 * than the specified hash value. 1022 */ 1023 if (!powerof2(hashsize)) { 1024 int oldhashsize = hashsize; 1025 1026 hashsize = maketcp_hashsize(hashsize); 1027 /* prevent absurdly low value */ 1028 if (hashsize < 16) 1029 hashsize = 16; 1030 printf("%s: WARNING: TCB hash size not a power of 2, " 1031 "clipped from %d to %d.\n", __func__, oldhashsize, 1032 hashsize); 1033 } 1034 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1035 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1036 1037 /* 1038 * These have to be type stable for the benefit of the timers. 1039 */ 1040 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1041 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1042 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1043 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1044 1045 tcp_tw_init(); 1046 syncache_init(); 1047 tcp_hc_init(); 1048 1049 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1050 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1051 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1052 1053 tcp_fastopen_init(); 1054 1055 /* Skip initialization of globals for non-default instances. */ 1056 if (!IS_DEFAULT_VNET(curvnet)) 1057 return; 1058 1059 tcp_reass_global_init(); 1060 1061 /* XXX virtualize those bellow? */ 1062 tcp_delacktime = TCPTV_DELACK; 1063 tcp_keepinit = TCPTV_KEEP_INIT; 1064 tcp_keepidle = TCPTV_KEEP_IDLE; 1065 tcp_keepintvl = TCPTV_KEEPINTVL; 1066 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1067 tcp_msl = TCPTV_MSL; 1068 tcp_rexmit_min = TCPTV_MIN; 1069 if (tcp_rexmit_min < 1) 1070 tcp_rexmit_min = 1; 1071 tcp_persmin = TCPTV_PERSMIN; 1072 tcp_persmax = TCPTV_PERSMAX; 1073 tcp_rexmit_slop = TCPTV_CPU_VAR; 1074 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1075 tcp_tcbhashsize = hashsize; 1076 1077 /* Setup the tcp function block list */ 1078 TAILQ_INIT(&t_functions); 1079 rw_init(&tcp_function_lock, "tcp_func_lock"); 1080 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1081 #ifdef TCP_BLACKBOX 1082 /* Initialize the TCP logging data. */ 1083 tcp_log_init(); 1084 #endif 1085 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1086 1087 if (tcp_soreceive_stream) { 1088 #ifdef INET 1089 tcp_usrreqs.pru_soreceive = soreceive_stream; 1090 #endif 1091 #ifdef INET6 1092 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1093 #endif /* INET6 */ 1094 } 1095 1096 #ifdef INET6 1097 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1098 #else /* INET6 */ 1099 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1100 #endif /* INET6 */ 1101 if (max_protohdr < TCP_MINPROTOHDR) 1102 max_protohdr = TCP_MINPROTOHDR; 1103 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1104 panic("tcp_init"); 1105 #undef TCP_MINPROTOHDR 1106 1107 ISN_LOCK_INIT(); 1108 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1109 SHUTDOWN_PRI_DEFAULT); 1110 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1111 EVENTHANDLER_PRI_ANY); 1112 #ifdef TCPPCAP 1113 tcp_pcap_init(); 1114 #endif 1115 } 1116 1117 #ifdef VIMAGE 1118 static void 1119 tcp_destroy(void *unused __unused) 1120 { 1121 int n; 1122 #ifdef TCP_HHOOK 1123 int error; 1124 #endif 1125 1126 /* 1127 * All our processes are gone, all our sockets should be cleaned 1128 * up, which means, we should be past the tcp_discardcb() calls. 1129 * Sleep to let all tcpcb timers really disappear and cleanup. 1130 */ 1131 for (;;) { 1132 INP_LIST_RLOCK(&V_tcbinfo); 1133 n = V_tcbinfo.ipi_count; 1134 INP_LIST_RUNLOCK(&V_tcbinfo); 1135 if (n == 0) 1136 break; 1137 pause("tcpdes", hz / 10); 1138 } 1139 tcp_hc_destroy(); 1140 syncache_destroy(); 1141 tcp_tw_destroy(); 1142 in_pcbinfo_destroy(&V_tcbinfo); 1143 /* tcp_discardcb() clears the sack_holes up. */ 1144 uma_zdestroy(V_sack_hole_zone); 1145 uma_zdestroy(V_tcpcb_zone); 1146 1147 /* 1148 * Cannot free the zone until all tcpcbs are released as we attach 1149 * the allocations to them. 1150 */ 1151 tcp_fastopen_destroy(); 1152 1153 #ifdef TCP_HHOOK 1154 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1155 if (error != 0) { 1156 printf("%s: WARNING: unable to deregister helper hook " 1157 "type=%d, id=%d: error %d returned\n", __func__, 1158 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1159 } 1160 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1161 if (error != 0) { 1162 printf("%s: WARNING: unable to deregister helper hook " 1163 "type=%d, id=%d: error %d returned\n", __func__, 1164 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1165 } 1166 #endif 1167 } 1168 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1169 #endif 1170 1171 void 1172 tcp_fini(void *xtp) 1173 { 1174 1175 } 1176 1177 /* 1178 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1179 * tcp_template used to store this data in mbufs, but we now recopy it out 1180 * of the tcpcb each time to conserve mbufs. 1181 */ 1182 void 1183 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1184 { 1185 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1186 1187 INP_WLOCK_ASSERT(inp); 1188 1189 #ifdef INET6 1190 if ((inp->inp_vflag & INP_IPV6) != 0) { 1191 struct ip6_hdr *ip6; 1192 1193 ip6 = (struct ip6_hdr *)ip_ptr; 1194 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1195 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1196 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1197 (IPV6_VERSION & IPV6_VERSION_MASK); 1198 ip6->ip6_nxt = IPPROTO_TCP; 1199 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1200 ip6->ip6_src = inp->in6p_laddr; 1201 ip6->ip6_dst = inp->in6p_faddr; 1202 } 1203 #endif /* INET6 */ 1204 #if defined(INET6) && defined(INET) 1205 else 1206 #endif 1207 #ifdef INET 1208 { 1209 struct ip *ip; 1210 1211 ip = (struct ip *)ip_ptr; 1212 ip->ip_v = IPVERSION; 1213 ip->ip_hl = 5; 1214 ip->ip_tos = inp->inp_ip_tos; 1215 ip->ip_len = 0; 1216 ip->ip_id = 0; 1217 ip->ip_off = 0; 1218 ip->ip_ttl = inp->inp_ip_ttl; 1219 ip->ip_sum = 0; 1220 ip->ip_p = IPPROTO_TCP; 1221 ip->ip_src = inp->inp_laddr; 1222 ip->ip_dst = inp->inp_faddr; 1223 } 1224 #endif /* INET */ 1225 th->th_sport = inp->inp_lport; 1226 th->th_dport = inp->inp_fport; 1227 th->th_seq = 0; 1228 th->th_ack = 0; 1229 th->th_x2 = 0; 1230 th->th_off = 5; 1231 th->th_flags = 0; 1232 th->th_win = 0; 1233 th->th_urp = 0; 1234 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1235 } 1236 1237 /* 1238 * Create template to be used to send tcp packets on a connection. 1239 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1240 * use for this function is in keepalives, which use tcp_respond. 1241 */ 1242 struct tcptemp * 1243 tcpip_maketemplate(struct inpcb *inp) 1244 { 1245 struct tcptemp *t; 1246 1247 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1248 if (t == NULL) 1249 return (NULL); 1250 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1251 return (t); 1252 } 1253 1254 /* 1255 * Send a single message to the TCP at address specified by 1256 * the given TCP/IP header. If m == NULL, then we make a copy 1257 * of the tcpiphdr at th and send directly to the addressed host. 1258 * This is used to force keep alive messages out using the TCP 1259 * template for a connection. If flags are given then we send 1260 * a message back to the TCP which originated the segment th, 1261 * and discard the mbuf containing it and any other attached mbufs. 1262 * 1263 * In any case the ack and sequence number of the transmitted 1264 * segment are as specified by the parameters. 1265 * 1266 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1267 */ 1268 void 1269 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1270 tcp_seq ack, tcp_seq seq, int flags) 1271 { 1272 struct tcpopt to; 1273 struct inpcb *inp; 1274 struct ip *ip; 1275 struct mbuf *optm; 1276 struct tcphdr *nth; 1277 u_char *optp; 1278 #ifdef INET6 1279 struct ip6_hdr *ip6; 1280 int isipv6; 1281 #endif /* INET6 */ 1282 int optlen, tlen, win; 1283 bool incl_opts; 1284 1285 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1286 1287 #ifdef INET6 1288 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1289 ip6 = ipgen; 1290 #endif /* INET6 */ 1291 ip = ipgen; 1292 1293 if (tp != NULL) { 1294 inp = tp->t_inpcb; 1295 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1296 INP_WLOCK_ASSERT(inp); 1297 } else 1298 inp = NULL; 1299 1300 incl_opts = false; 1301 win = 0; 1302 if (tp != NULL) { 1303 if (!(flags & TH_RST)) { 1304 win = sbspace(&inp->inp_socket->so_rcv); 1305 if (win > TCP_MAXWIN << tp->rcv_scale) 1306 win = TCP_MAXWIN << tp->rcv_scale; 1307 } 1308 if ((tp->t_flags & TF_NOOPT) == 0) 1309 incl_opts = true; 1310 } 1311 if (m == NULL) { 1312 m = m_gethdr(M_NOWAIT, MT_DATA); 1313 if (m == NULL) 1314 return; 1315 m->m_data += max_linkhdr; 1316 #ifdef INET6 1317 if (isipv6) { 1318 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1319 sizeof(struct ip6_hdr)); 1320 ip6 = mtod(m, struct ip6_hdr *); 1321 nth = (struct tcphdr *)(ip6 + 1); 1322 } else 1323 #endif /* INET6 */ 1324 { 1325 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1326 ip = mtod(m, struct ip *); 1327 nth = (struct tcphdr *)(ip + 1); 1328 } 1329 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1330 flags = TH_ACK; 1331 } else if (!M_WRITABLE(m)) { 1332 struct mbuf *n; 1333 1334 /* Can't reuse 'm', allocate a new mbuf. */ 1335 n = m_gethdr(M_NOWAIT, MT_DATA); 1336 if (n == NULL) { 1337 m_freem(m); 1338 return; 1339 } 1340 1341 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1342 m_freem(m); 1343 m_freem(n); 1344 return; 1345 } 1346 1347 n->m_data += max_linkhdr; 1348 /* m_len is set later */ 1349 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1350 #ifdef INET6 1351 if (isipv6) { 1352 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1353 sizeof(struct ip6_hdr)); 1354 ip6 = mtod(n, struct ip6_hdr *); 1355 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1356 nth = (struct tcphdr *)(ip6 + 1); 1357 } else 1358 #endif /* INET6 */ 1359 { 1360 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1361 ip = mtod(n, struct ip *); 1362 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1363 nth = (struct tcphdr *)(ip + 1); 1364 } 1365 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1366 xchg(nth->th_dport, nth->th_sport, uint16_t); 1367 th = nth; 1368 m_freem(m); 1369 m = n; 1370 } else { 1371 /* 1372 * reuse the mbuf. 1373 * XXX MRT We inherit the FIB, which is lucky. 1374 */ 1375 m_freem(m->m_next); 1376 m->m_next = NULL; 1377 m->m_data = (caddr_t)ipgen; 1378 /* m_len is set later */ 1379 #ifdef INET6 1380 if (isipv6) { 1381 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1382 nth = (struct tcphdr *)(ip6 + 1); 1383 } else 1384 #endif /* INET6 */ 1385 { 1386 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1387 nth = (struct tcphdr *)(ip + 1); 1388 } 1389 if (th != nth) { 1390 /* 1391 * this is usually a case when an extension header 1392 * exists between the IPv6 header and the 1393 * TCP header. 1394 */ 1395 nth->th_sport = th->th_sport; 1396 nth->th_dport = th->th_dport; 1397 } 1398 xchg(nth->th_dport, nth->th_sport, uint16_t); 1399 #undef xchg 1400 } 1401 tlen = 0; 1402 #ifdef INET6 1403 if (isipv6) 1404 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1405 #endif 1406 #if defined(INET) && defined(INET6) 1407 else 1408 #endif 1409 #ifdef INET 1410 tlen = sizeof (struct tcpiphdr); 1411 #endif 1412 #ifdef INVARIANTS 1413 m->m_len = 0; 1414 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1415 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1416 m, tlen, (long)M_TRAILINGSPACE(m))); 1417 #endif 1418 m->m_len = tlen; 1419 to.to_flags = 0; 1420 if (incl_opts) { 1421 /* Make sure we have room. */ 1422 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1423 m->m_next = m_get(M_NOWAIT, MT_DATA); 1424 if (m->m_next) { 1425 optp = mtod(m->m_next, u_char *); 1426 optm = m->m_next; 1427 } else 1428 incl_opts = false; 1429 } else { 1430 optp = (u_char *) (nth + 1); 1431 optm = m; 1432 } 1433 } 1434 if (incl_opts) { 1435 /* Timestamps. */ 1436 if (tp->t_flags & TF_RCVD_TSTMP) { 1437 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1438 to.to_tsecr = tp->ts_recent; 1439 to.to_flags |= TOF_TS; 1440 } 1441 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1442 /* TCP-MD5 (RFC2385). */ 1443 if (tp->t_flags & TF_SIGNATURE) 1444 to.to_flags |= TOF_SIGNATURE; 1445 #endif 1446 /* Add the options. */ 1447 tlen += optlen = tcp_addoptions(&to, optp); 1448 1449 /* Update m_len in the correct mbuf. */ 1450 optm->m_len += optlen; 1451 } else 1452 optlen = 0; 1453 #ifdef INET6 1454 if (isipv6) { 1455 ip6->ip6_flow = 0; 1456 ip6->ip6_vfc = IPV6_VERSION; 1457 ip6->ip6_nxt = IPPROTO_TCP; 1458 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1459 } 1460 #endif 1461 #if defined(INET) && defined(INET6) 1462 else 1463 #endif 1464 #ifdef INET 1465 { 1466 ip->ip_len = htons(tlen); 1467 ip->ip_ttl = V_ip_defttl; 1468 if (V_path_mtu_discovery) 1469 ip->ip_off |= htons(IP_DF); 1470 } 1471 #endif 1472 m->m_pkthdr.len = tlen; 1473 m->m_pkthdr.rcvif = NULL; 1474 #ifdef MAC 1475 if (inp != NULL) { 1476 /* 1477 * Packet is associated with a socket, so allow the 1478 * label of the response to reflect the socket label. 1479 */ 1480 INP_WLOCK_ASSERT(inp); 1481 mac_inpcb_create_mbuf(inp, m); 1482 } else { 1483 /* 1484 * Packet is not associated with a socket, so possibly 1485 * update the label in place. 1486 */ 1487 mac_netinet_tcp_reply(m); 1488 } 1489 #endif 1490 nth->th_seq = htonl(seq); 1491 nth->th_ack = htonl(ack); 1492 nth->th_x2 = 0; 1493 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1494 nth->th_flags = flags; 1495 if (tp != NULL) 1496 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1497 else 1498 nth->th_win = htons((u_short)win); 1499 nth->th_urp = 0; 1500 1501 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1502 if (to.to_flags & TOF_SIGNATURE) { 1503 if (!TCPMD5_ENABLED() || 1504 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1505 m_freem(m); 1506 return; 1507 } 1508 } 1509 #endif 1510 1511 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1512 #ifdef INET6 1513 if (isipv6) { 1514 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1515 nth->th_sum = in6_cksum_pseudo(ip6, 1516 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1517 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1518 NULL, NULL); 1519 } 1520 #endif /* INET6 */ 1521 #if defined(INET6) && defined(INET) 1522 else 1523 #endif 1524 #ifdef INET 1525 { 1526 m->m_pkthdr.csum_flags = CSUM_TCP; 1527 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1528 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1529 } 1530 #endif /* INET */ 1531 #ifdef TCPDEBUG 1532 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1533 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1534 #endif 1535 TCP_PROBE3(debug__output, tp, th, m); 1536 if (flags & TH_RST) 1537 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1538 1539 #ifdef INET6 1540 if (isipv6) { 1541 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1542 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1543 } 1544 #endif /* INET6 */ 1545 #if defined(INET) && defined(INET6) 1546 else 1547 #endif 1548 #ifdef INET 1549 { 1550 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1551 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1552 } 1553 #endif 1554 } 1555 1556 /* 1557 * Create a new TCP control block, making an 1558 * empty reassembly queue and hooking it to the argument 1559 * protocol control block. The `inp' parameter must have 1560 * come from the zone allocator set up in tcp_init(). 1561 */ 1562 struct tcpcb * 1563 tcp_newtcpcb(struct inpcb *inp) 1564 { 1565 struct tcpcb_mem *tm; 1566 struct tcpcb *tp; 1567 #ifdef INET6 1568 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1569 #endif /* INET6 */ 1570 1571 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1572 if (tm == NULL) 1573 return (NULL); 1574 tp = &tm->tcb; 1575 1576 /* Initialise cc_var struct for this tcpcb. */ 1577 tp->ccv = &tm->ccv; 1578 tp->ccv->type = IPPROTO_TCP; 1579 tp->ccv->ccvc.tcp = tp; 1580 rw_rlock(&tcp_function_lock); 1581 tp->t_fb = tcp_func_set_ptr; 1582 refcount_acquire(&tp->t_fb->tfb_refcnt); 1583 rw_runlock(&tcp_function_lock); 1584 /* 1585 * Use the current system default CC algorithm. 1586 */ 1587 CC_LIST_RLOCK(); 1588 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1589 CC_ALGO(tp) = CC_DEFAULT(); 1590 CC_LIST_RUNLOCK(); 1591 1592 if (CC_ALGO(tp)->cb_init != NULL) 1593 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1594 if (tp->t_fb->tfb_tcp_fb_fini) 1595 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1596 refcount_release(&tp->t_fb->tfb_refcnt); 1597 uma_zfree(V_tcpcb_zone, tm); 1598 return (NULL); 1599 } 1600 1601 #ifdef TCP_HHOOK 1602 tp->osd = &tm->osd; 1603 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1604 if (tp->t_fb->tfb_tcp_fb_fini) 1605 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1606 refcount_release(&tp->t_fb->tfb_refcnt); 1607 uma_zfree(V_tcpcb_zone, tm); 1608 return (NULL); 1609 } 1610 #endif 1611 1612 #ifdef VIMAGE 1613 tp->t_vnet = inp->inp_vnet; 1614 #endif 1615 tp->t_timers = &tm->tt; 1616 TAILQ_INIT(&tp->t_segq); 1617 tp->t_maxseg = 1618 #ifdef INET6 1619 isipv6 ? V_tcp_v6mssdflt : 1620 #endif /* INET6 */ 1621 V_tcp_mssdflt; 1622 1623 /* Set up our timeouts. */ 1624 callout_init(&tp->t_timers->tt_rexmt, 1); 1625 callout_init(&tp->t_timers->tt_persist, 1); 1626 callout_init(&tp->t_timers->tt_keep, 1); 1627 callout_init(&tp->t_timers->tt_2msl, 1); 1628 callout_init(&tp->t_timers->tt_delack, 1); 1629 1630 if (V_tcp_do_rfc1323) 1631 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1632 if (V_tcp_do_sack) 1633 tp->t_flags |= TF_SACK_PERMIT; 1634 TAILQ_INIT(&tp->snd_holes); 1635 /* 1636 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1637 * is called. 1638 */ 1639 in_pcbref(inp); /* Reference for tcpcb */ 1640 tp->t_inpcb = inp; 1641 1642 /* 1643 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1644 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1645 * reasonable initial retransmit time. 1646 */ 1647 tp->t_srtt = TCPTV_SRTTBASE; 1648 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1649 tp->t_rttmin = tcp_rexmit_min; 1650 tp->t_rxtcur = TCPTV_RTOBASE; 1651 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1652 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1653 tp->t_rcvtime = ticks; 1654 /* 1655 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1656 * because the socket may be bound to an IPv6 wildcard address, 1657 * which may match an IPv4-mapped IPv6 address. 1658 */ 1659 inp->inp_ip_ttl = V_ip_defttl; 1660 inp->inp_ppcb = tp; 1661 #ifdef TCPPCAP 1662 /* 1663 * Init the TCP PCAP queues. 1664 */ 1665 tcp_pcap_tcpcb_init(tp); 1666 #endif 1667 #ifdef TCP_BLACKBOX 1668 /* Initialize the per-TCPCB log data. */ 1669 tcp_log_tcpcbinit(tp); 1670 #endif 1671 if (tp->t_fb->tfb_tcp_fb_init) { 1672 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1673 } 1674 return (tp); /* XXX */ 1675 } 1676 1677 /* 1678 * Switch the congestion control algorithm back to NewReno for any active 1679 * control blocks using an algorithm which is about to go away. 1680 * This ensures the CC framework can allow the unload to proceed without leaving 1681 * any dangling pointers which would trigger a panic. 1682 * Returning non-zero would inform the CC framework that something went wrong 1683 * and it would be unsafe to allow the unload to proceed. However, there is no 1684 * way for this to occur with this implementation so we always return zero. 1685 */ 1686 int 1687 tcp_ccalgounload(struct cc_algo *unload_algo) 1688 { 1689 struct cc_algo *tmpalgo; 1690 struct inpcb *inp; 1691 struct tcpcb *tp; 1692 VNET_ITERATOR_DECL(vnet_iter); 1693 1694 /* 1695 * Check all active control blocks across all network stacks and change 1696 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1697 * requires cleanup code to be run, call it. 1698 */ 1699 VNET_LIST_RLOCK(); 1700 VNET_FOREACH(vnet_iter) { 1701 CURVNET_SET(vnet_iter); 1702 INP_INFO_WLOCK(&V_tcbinfo); 1703 /* 1704 * New connections already part way through being initialised 1705 * with the CC algo we're removing will not race with this code 1706 * because the INP_INFO_WLOCK is held during initialisation. We 1707 * therefore don't enter the loop below until the connection 1708 * list has stabilised. 1709 */ 1710 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1711 INP_WLOCK(inp); 1712 /* Important to skip tcptw structs. */ 1713 if (!(inp->inp_flags & INP_TIMEWAIT) && 1714 (tp = intotcpcb(inp)) != NULL) { 1715 /* 1716 * By holding INP_WLOCK here, we are assured 1717 * that the connection is not currently 1718 * executing inside the CC module's functions 1719 * i.e. it is safe to make the switch back to 1720 * NewReno. 1721 */ 1722 if (CC_ALGO(tp) == unload_algo) { 1723 tmpalgo = CC_ALGO(tp); 1724 if (tmpalgo->cb_destroy != NULL) 1725 tmpalgo->cb_destroy(tp->ccv); 1726 CC_DATA(tp) = NULL; 1727 /* 1728 * NewReno may allocate memory on 1729 * demand for certain stateful 1730 * configuration as needed, but is 1731 * coded to never fail on memory 1732 * allocation failure so it is a safe 1733 * fallback. 1734 */ 1735 CC_ALGO(tp) = &newreno_cc_algo; 1736 } 1737 } 1738 INP_WUNLOCK(inp); 1739 } 1740 INP_INFO_WUNLOCK(&V_tcbinfo); 1741 CURVNET_RESTORE(); 1742 } 1743 VNET_LIST_RUNLOCK(); 1744 1745 return (0); 1746 } 1747 1748 /* 1749 * Drop a TCP connection, reporting 1750 * the specified error. If connection is synchronized, 1751 * then send a RST to peer. 1752 */ 1753 struct tcpcb * 1754 tcp_drop(struct tcpcb *tp, int errno) 1755 { 1756 struct socket *so = tp->t_inpcb->inp_socket; 1757 1758 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1759 INP_WLOCK_ASSERT(tp->t_inpcb); 1760 1761 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1762 tcp_state_change(tp, TCPS_CLOSED); 1763 (void) tp->t_fb->tfb_tcp_output(tp); 1764 TCPSTAT_INC(tcps_drops); 1765 } else 1766 TCPSTAT_INC(tcps_conndrops); 1767 if (errno == ETIMEDOUT && tp->t_softerror) 1768 errno = tp->t_softerror; 1769 so->so_error = errno; 1770 return (tcp_close(tp)); 1771 } 1772 1773 void 1774 tcp_discardcb(struct tcpcb *tp) 1775 { 1776 struct inpcb *inp = tp->t_inpcb; 1777 struct socket *so = inp->inp_socket; 1778 #ifdef INET6 1779 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1780 #endif /* INET6 */ 1781 int released __unused; 1782 1783 INP_WLOCK_ASSERT(inp); 1784 1785 /* 1786 * Make sure that all of our timers are stopped before we delete the 1787 * PCB. 1788 * 1789 * If stopping a timer fails, we schedule a discard function in same 1790 * callout, and the last discard function called will take care of 1791 * deleting the tcpcb. 1792 */ 1793 tp->t_timers->tt_draincnt = 0; 1794 tcp_timer_stop(tp, TT_REXMT); 1795 tcp_timer_stop(tp, TT_PERSIST); 1796 tcp_timer_stop(tp, TT_KEEP); 1797 tcp_timer_stop(tp, TT_2MSL); 1798 tcp_timer_stop(tp, TT_DELACK); 1799 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1800 /* 1801 * Call the stop-all function of the methods, 1802 * this function should call the tcp_timer_stop() 1803 * method with each of the function specific timeouts. 1804 * That stop will be called via the tfb_tcp_timer_stop() 1805 * which should use the async drain function of the 1806 * callout system (see tcp_var.h). 1807 */ 1808 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1809 } 1810 1811 /* 1812 * If we got enough samples through the srtt filter, 1813 * save the rtt and rttvar in the routing entry. 1814 * 'Enough' is arbitrarily defined as 4 rtt samples. 1815 * 4 samples is enough for the srtt filter to converge 1816 * to within enough % of the correct value; fewer samples 1817 * and we could save a bogus rtt. The danger is not high 1818 * as tcp quickly recovers from everything. 1819 * XXX: Works very well but needs some more statistics! 1820 */ 1821 if (tp->t_rttupdated >= 4) { 1822 struct hc_metrics_lite metrics; 1823 uint32_t ssthresh; 1824 1825 bzero(&metrics, sizeof(metrics)); 1826 /* 1827 * Update the ssthresh always when the conditions below 1828 * are satisfied. This gives us better new start value 1829 * for the congestion avoidance for new connections. 1830 * ssthresh is only set if packet loss occurred on a session. 1831 * 1832 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1833 * being torn down. Ideally this code would not use 'so'. 1834 */ 1835 ssthresh = tp->snd_ssthresh; 1836 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1837 /* 1838 * convert the limit from user data bytes to 1839 * packets then to packet data bytes. 1840 */ 1841 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1842 if (ssthresh < 2) 1843 ssthresh = 2; 1844 ssthresh *= (tp->t_maxseg + 1845 #ifdef INET6 1846 (isipv6 ? sizeof (struct ip6_hdr) + 1847 sizeof (struct tcphdr) : 1848 #endif 1849 sizeof (struct tcpiphdr) 1850 #ifdef INET6 1851 ) 1852 #endif 1853 ); 1854 } else 1855 ssthresh = 0; 1856 metrics.rmx_ssthresh = ssthresh; 1857 1858 metrics.rmx_rtt = tp->t_srtt; 1859 metrics.rmx_rttvar = tp->t_rttvar; 1860 metrics.rmx_cwnd = tp->snd_cwnd; 1861 metrics.rmx_sendpipe = 0; 1862 metrics.rmx_recvpipe = 0; 1863 1864 tcp_hc_update(&inp->inp_inc, &metrics); 1865 } 1866 1867 /* free the reassembly queue, if any */ 1868 tcp_reass_flush(tp); 1869 1870 #ifdef TCP_OFFLOAD 1871 /* Disconnect offload device, if any. */ 1872 if (tp->t_flags & TF_TOE) 1873 tcp_offload_detach(tp); 1874 #endif 1875 1876 tcp_free_sackholes(tp); 1877 1878 #ifdef TCPPCAP 1879 /* Free the TCP PCAP queues. */ 1880 tcp_pcap_drain(&(tp->t_inpkts)); 1881 tcp_pcap_drain(&(tp->t_outpkts)); 1882 #endif 1883 1884 /* Allow the CC algorithm to clean up after itself. */ 1885 if (CC_ALGO(tp)->cb_destroy != NULL) 1886 CC_ALGO(tp)->cb_destroy(tp->ccv); 1887 CC_DATA(tp) = NULL; 1888 1889 #ifdef TCP_HHOOK 1890 khelp_destroy_osd(tp->osd); 1891 #endif 1892 1893 CC_ALGO(tp) = NULL; 1894 inp->inp_ppcb = NULL; 1895 if (tp->t_timers->tt_draincnt == 0) { 1896 /* We own the last reference on tcpcb, let's free it. */ 1897 #ifdef TCP_BLACKBOX 1898 tcp_log_tcpcbfini(tp); 1899 #endif 1900 TCPSTATES_DEC(tp->t_state); 1901 if (tp->t_fb->tfb_tcp_fb_fini) 1902 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1903 refcount_release(&tp->t_fb->tfb_refcnt); 1904 tp->t_inpcb = NULL; 1905 uma_zfree(V_tcpcb_zone, tp); 1906 released = in_pcbrele_wlocked(inp); 1907 KASSERT(!released, ("%s: inp %p should not have been released " 1908 "here", __func__, inp)); 1909 } 1910 } 1911 1912 void 1913 tcp_timer_discard(void *ptp) 1914 { 1915 struct inpcb *inp; 1916 struct tcpcb *tp; 1917 struct epoch_tracker et; 1918 1919 tp = (struct tcpcb *)ptp; 1920 CURVNET_SET(tp->t_vnet); 1921 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 1922 inp = tp->t_inpcb; 1923 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1924 __func__, tp)); 1925 INP_WLOCK(inp); 1926 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1927 ("%s: tcpcb has to be stopped here", __func__)); 1928 tp->t_timers->tt_draincnt--; 1929 if (tp->t_timers->tt_draincnt == 0) { 1930 /* We own the last reference on this tcpcb, let's free it. */ 1931 #ifdef TCP_BLACKBOX 1932 tcp_log_tcpcbfini(tp); 1933 #endif 1934 TCPSTATES_DEC(tp->t_state); 1935 if (tp->t_fb->tfb_tcp_fb_fini) 1936 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1937 refcount_release(&tp->t_fb->tfb_refcnt); 1938 tp->t_inpcb = NULL; 1939 uma_zfree(V_tcpcb_zone, tp); 1940 if (in_pcbrele_wlocked(inp)) { 1941 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1942 CURVNET_RESTORE(); 1943 return; 1944 } 1945 } 1946 INP_WUNLOCK(inp); 1947 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1948 CURVNET_RESTORE(); 1949 } 1950 1951 /* 1952 * Attempt to close a TCP control block, marking it as dropped, and freeing 1953 * the socket if we hold the only reference. 1954 */ 1955 struct tcpcb * 1956 tcp_close(struct tcpcb *tp) 1957 { 1958 struct inpcb *inp = tp->t_inpcb; 1959 struct socket *so; 1960 1961 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1962 INP_WLOCK_ASSERT(inp); 1963 1964 #ifdef TCP_OFFLOAD 1965 if (tp->t_state == TCPS_LISTEN) 1966 tcp_offload_listen_stop(tp); 1967 #endif 1968 /* 1969 * This releases the TFO pending counter resource for TFO listen 1970 * sockets as well as passively-created TFO sockets that transition 1971 * from SYN_RECEIVED to CLOSED. 1972 */ 1973 if (tp->t_tfo_pending) { 1974 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1975 tp->t_tfo_pending = NULL; 1976 } 1977 in_pcbdrop(inp); 1978 TCPSTAT_INC(tcps_closed); 1979 if (tp->t_state != TCPS_CLOSED) 1980 tcp_state_change(tp, TCPS_CLOSED); 1981 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1982 so = inp->inp_socket; 1983 soisdisconnected(so); 1984 if (inp->inp_flags & INP_SOCKREF) { 1985 KASSERT(so->so_state & SS_PROTOREF, 1986 ("tcp_close: !SS_PROTOREF")); 1987 inp->inp_flags &= ~INP_SOCKREF; 1988 INP_WUNLOCK(inp); 1989 SOCK_LOCK(so); 1990 so->so_state &= ~SS_PROTOREF; 1991 sofree(so); 1992 return (NULL); 1993 } 1994 return (tp); 1995 } 1996 1997 void 1998 tcp_drain(void) 1999 { 2000 VNET_ITERATOR_DECL(vnet_iter); 2001 2002 if (!do_tcpdrain) 2003 return; 2004 2005 VNET_LIST_RLOCK_NOSLEEP(); 2006 VNET_FOREACH(vnet_iter) { 2007 CURVNET_SET(vnet_iter); 2008 struct inpcb *inpb; 2009 struct tcpcb *tcpb; 2010 2011 /* 2012 * Walk the tcpbs, if existing, and flush the reassembly queue, 2013 * if there is one... 2014 * XXX: The "Net/3" implementation doesn't imply that the TCP 2015 * reassembly queue should be flushed, but in a situation 2016 * where we're really low on mbufs, this is potentially 2017 * useful. 2018 */ 2019 INP_INFO_WLOCK(&V_tcbinfo); 2020 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2021 INP_WLOCK(inpb); 2022 if (inpb->inp_flags & INP_TIMEWAIT) { 2023 INP_WUNLOCK(inpb); 2024 continue; 2025 } 2026 if ((tcpb = intotcpcb(inpb)) != NULL) { 2027 tcp_reass_flush(tcpb); 2028 tcp_clean_sackreport(tcpb); 2029 #ifdef TCP_BLACKBOX 2030 tcp_log_drain(tcpb); 2031 #endif 2032 #ifdef TCPPCAP 2033 if (tcp_pcap_aggressive_free) { 2034 /* Free the TCP PCAP queues. */ 2035 tcp_pcap_drain(&(tcpb->t_inpkts)); 2036 tcp_pcap_drain(&(tcpb->t_outpkts)); 2037 } 2038 #endif 2039 } 2040 INP_WUNLOCK(inpb); 2041 } 2042 INP_INFO_WUNLOCK(&V_tcbinfo); 2043 CURVNET_RESTORE(); 2044 } 2045 VNET_LIST_RUNLOCK_NOSLEEP(); 2046 } 2047 2048 /* 2049 * Notify a tcp user of an asynchronous error; 2050 * store error as soft error, but wake up user 2051 * (for now, won't do anything until can select for soft error). 2052 * 2053 * Do not wake up user since there currently is no mechanism for 2054 * reporting soft errors (yet - a kqueue filter may be added). 2055 */ 2056 static struct inpcb * 2057 tcp_notify(struct inpcb *inp, int error) 2058 { 2059 struct tcpcb *tp; 2060 2061 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2062 INP_WLOCK_ASSERT(inp); 2063 2064 if ((inp->inp_flags & INP_TIMEWAIT) || 2065 (inp->inp_flags & INP_DROPPED)) 2066 return (inp); 2067 2068 tp = intotcpcb(inp); 2069 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2070 2071 /* 2072 * Ignore some errors if we are hooked up. 2073 * If connection hasn't completed, has retransmitted several times, 2074 * and receives a second error, give up now. This is better 2075 * than waiting a long time to establish a connection that 2076 * can never complete. 2077 */ 2078 if (tp->t_state == TCPS_ESTABLISHED && 2079 (error == EHOSTUNREACH || error == ENETUNREACH || 2080 error == EHOSTDOWN)) { 2081 if (inp->inp_route.ro_rt) { 2082 RTFREE(inp->inp_route.ro_rt); 2083 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2084 } 2085 return (inp); 2086 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2087 tp->t_softerror) { 2088 tp = tcp_drop(tp, error); 2089 if (tp != NULL) 2090 return (inp); 2091 else 2092 return (NULL); 2093 } else { 2094 tp->t_softerror = error; 2095 return (inp); 2096 } 2097 #if 0 2098 wakeup( &so->so_timeo); 2099 sorwakeup(so); 2100 sowwakeup(so); 2101 #endif 2102 } 2103 2104 static int 2105 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2106 { 2107 int error, i, m, n, pcb_count; 2108 struct inpcb *inp, **inp_list; 2109 inp_gen_t gencnt; 2110 struct xinpgen xig; 2111 struct epoch_tracker et; 2112 2113 /* 2114 * The process of preparing the TCB list is too time-consuming and 2115 * resource-intensive to repeat twice on every request. 2116 */ 2117 if (req->oldptr == NULL) { 2118 n = V_tcbinfo.ipi_count + 2119 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2120 n += imax(n / 8, 10); 2121 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2122 return (0); 2123 } 2124 2125 if (req->newptr != NULL) 2126 return (EPERM); 2127 2128 /* 2129 * OK, now we're committed to doing something. 2130 */ 2131 INP_LIST_RLOCK(&V_tcbinfo); 2132 gencnt = V_tcbinfo.ipi_gencnt; 2133 n = V_tcbinfo.ipi_count; 2134 INP_LIST_RUNLOCK(&V_tcbinfo); 2135 2136 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2137 2138 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2139 + (n + m) * sizeof(struct xtcpcb)); 2140 if (error != 0) 2141 return (error); 2142 2143 bzero(&xig, sizeof(xig)); 2144 xig.xig_len = sizeof xig; 2145 xig.xig_count = n + m; 2146 xig.xig_gen = gencnt; 2147 xig.xig_sogen = so_gencnt; 2148 error = SYSCTL_OUT(req, &xig, sizeof xig); 2149 if (error) 2150 return (error); 2151 2152 error = syncache_pcblist(req, m, &pcb_count); 2153 if (error) 2154 return (error); 2155 2156 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2157 2158 INP_INFO_WLOCK(&V_tcbinfo); 2159 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2160 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) { 2161 INP_WLOCK(inp); 2162 if (inp->inp_gencnt <= gencnt) { 2163 /* 2164 * XXX: This use of cr_cansee(), introduced with 2165 * TCP state changes, is not quite right, but for 2166 * now, better than nothing. 2167 */ 2168 if (inp->inp_flags & INP_TIMEWAIT) { 2169 if (intotw(inp) != NULL) 2170 error = cr_cansee(req->td->td_ucred, 2171 intotw(inp)->tw_cred); 2172 else 2173 error = EINVAL; /* Skip this inp. */ 2174 } else 2175 error = cr_canseeinpcb(req->td->td_ucred, inp); 2176 if (error == 0) { 2177 in_pcbref(inp); 2178 inp_list[i++] = inp; 2179 } 2180 } 2181 INP_WUNLOCK(inp); 2182 } 2183 INP_INFO_WUNLOCK(&V_tcbinfo); 2184 n = i; 2185 2186 error = 0; 2187 for (i = 0; i < n; i++) { 2188 inp = inp_list[i]; 2189 INP_RLOCK(inp); 2190 if (inp->inp_gencnt <= gencnt) { 2191 struct xtcpcb xt; 2192 2193 tcp_inptoxtp(inp, &xt); 2194 INP_RUNLOCK(inp); 2195 error = SYSCTL_OUT(req, &xt, sizeof xt); 2196 } else 2197 INP_RUNLOCK(inp); 2198 } 2199 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2200 for (i = 0; i < n; i++) { 2201 inp = inp_list[i]; 2202 INP_RLOCK(inp); 2203 if (!in_pcbrele_rlocked(inp)) 2204 INP_RUNLOCK(inp); 2205 } 2206 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2207 2208 if (!error) { 2209 /* 2210 * Give the user an updated idea of our state. 2211 * If the generation differs from what we told 2212 * her before, she knows that something happened 2213 * while we were processing this request, and it 2214 * might be necessary to retry. 2215 */ 2216 INP_LIST_RLOCK(&V_tcbinfo); 2217 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2218 xig.xig_sogen = so_gencnt; 2219 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2220 INP_LIST_RUNLOCK(&V_tcbinfo); 2221 error = SYSCTL_OUT(req, &xig, sizeof xig); 2222 } 2223 free(inp_list, M_TEMP); 2224 return (error); 2225 } 2226 2227 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2228 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2229 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2230 2231 #ifdef INET 2232 static int 2233 tcp_getcred(SYSCTL_HANDLER_ARGS) 2234 { 2235 struct xucred xuc; 2236 struct sockaddr_in addrs[2]; 2237 struct inpcb *inp; 2238 int error; 2239 2240 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2241 if (error) 2242 return (error); 2243 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2244 if (error) 2245 return (error); 2246 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2247 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2248 if (inp != NULL) { 2249 if (inp->inp_socket == NULL) 2250 error = ENOENT; 2251 if (error == 0) 2252 error = cr_canseeinpcb(req->td->td_ucred, inp); 2253 if (error == 0) 2254 cru2x(inp->inp_cred, &xuc); 2255 INP_RUNLOCK(inp); 2256 } else 2257 error = ENOENT; 2258 if (error == 0) 2259 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2260 return (error); 2261 } 2262 2263 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2264 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2265 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2266 #endif /* INET */ 2267 2268 #ifdef INET6 2269 static int 2270 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2271 { 2272 struct xucred xuc; 2273 struct sockaddr_in6 addrs[2]; 2274 struct inpcb *inp; 2275 int error; 2276 #ifdef INET 2277 int mapped = 0; 2278 #endif 2279 2280 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2281 if (error) 2282 return (error); 2283 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2284 if (error) 2285 return (error); 2286 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2287 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2288 return (error); 2289 } 2290 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2291 #ifdef INET 2292 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2293 mapped = 1; 2294 else 2295 #endif 2296 return (EINVAL); 2297 } 2298 2299 #ifdef INET 2300 if (mapped == 1) 2301 inp = in_pcblookup(&V_tcbinfo, 2302 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2303 addrs[1].sin6_port, 2304 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2305 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2306 else 2307 #endif 2308 inp = in6_pcblookup(&V_tcbinfo, 2309 &addrs[1].sin6_addr, addrs[1].sin6_port, 2310 &addrs[0].sin6_addr, addrs[0].sin6_port, 2311 INPLOOKUP_RLOCKPCB, NULL); 2312 if (inp != NULL) { 2313 if (inp->inp_socket == NULL) 2314 error = ENOENT; 2315 if (error == 0) 2316 error = cr_canseeinpcb(req->td->td_ucred, inp); 2317 if (error == 0) 2318 cru2x(inp->inp_cred, &xuc); 2319 INP_RUNLOCK(inp); 2320 } else 2321 error = ENOENT; 2322 if (error == 0) 2323 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2324 return (error); 2325 } 2326 2327 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2328 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2329 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2330 #endif /* INET6 */ 2331 2332 2333 #ifdef INET 2334 void 2335 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2336 { 2337 struct ip *ip = vip; 2338 struct tcphdr *th; 2339 struct in_addr faddr; 2340 struct inpcb *inp; 2341 struct tcpcb *tp; 2342 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2343 struct icmp *icp; 2344 struct in_conninfo inc; 2345 struct epoch_tracker et; 2346 tcp_seq icmp_tcp_seq; 2347 int mtu; 2348 2349 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2350 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2351 return; 2352 2353 if (cmd == PRC_MSGSIZE) 2354 notify = tcp_mtudisc_notify; 2355 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2356 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2357 cmd == PRC_TIMXCEED_INTRANS) && ip) 2358 notify = tcp_drop_syn_sent; 2359 2360 /* 2361 * Hostdead is ugly because it goes linearly through all PCBs. 2362 * XXX: We never get this from ICMP, otherwise it makes an 2363 * excellent DoS attack on machines with many connections. 2364 */ 2365 else if (cmd == PRC_HOSTDEAD) 2366 ip = NULL; 2367 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2368 return; 2369 2370 if (ip == NULL) { 2371 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2372 return; 2373 } 2374 2375 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2376 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2377 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2378 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2379 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2380 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2381 /* signal EHOSTDOWN, as it flushes the cached route */ 2382 inp = (*notify)(inp, EHOSTDOWN); 2383 goto out; 2384 } 2385 icmp_tcp_seq = th->th_seq; 2386 if (inp != NULL) { 2387 if (!(inp->inp_flags & INP_TIMEWAIT) && 2388 !(inp->inp_flags & INP_DROPPED) && 2389 !(inp->inp_socket == NULL)) { 2390 tp = intotcpcb(inp); 2391 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2392 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2393 if (cmd == PRC_MSGSIZE) { 2394 /* 2395 * MTU discovery: 2396 * If we got a needfrag set the MTU 2397 * in the route to the suggested new 2398 * value (if given) and then notify. 2399 */ 2400 mtu = ntohs(icp->icmp_nextmtu); 2401 /* 2402 * If no alternative MTU was 2403 * proposed, try the next smaller 2404 * one. 2405 */ 2406 if (!mtu) 2407 mtu = ip_next_mtu( 2408 ntohs(ip->ip_len), 1); 2409 if (mtu < V_tcp_minmss + 2410 sizeof(struct tcpiphdr)) 2411 mtu = V_tcp_minmss + 2412 sizeof(struct tcpiphdr); 2413 /* 2414 * Only process the offered MTU if it 2415 * is smaller than the current one. 2416 */ 2417 if (mtu < tp->t_maxseg + 2418 sizeof(struct tcpiphdr)) { 2419 bzero(&inc, sizeof(inc)); 2420 inc.inc_faddr = faddr; 2421 inc.inc_fibnum = 2422 inp->inp_inc.inc_fibnum; 2423 tcp_hc_updatemtu(&inc, mtu); 2424 tcp_mtudisc(inp, mtu); 2425 } 2426 } else 2427 inp = (*notify)(inp, 2428 inetctlerrmap[cmd]); 2429 } 2430 } 2431 } else { 2432 bzero(&inc, sizeof(inc)); 2433 inc.inc_fport = th->th_dport; 2434 inc.inc_lport = th->th_sport; 2435 inc.inc_faddr = faddr; 2436 inc.inc_laddr = ip->ip_src; 2437 syncache_unreach(&inc, icmp_tcp_seq); 2438 } 2439 out: 2440 if (inp != NULL) 2441 INP_WUNLOCK(inp); 2442 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2443 } 2444 #endif /* INET */ 2445 2446 #ifdef INET6 2447 void 2448 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2449 { 2450 struct in6_addr *dst; 2451 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2452 struct ip6_hdr *ip6; 2453 struct mbuf *m; 2454 struct inpcb *inp; 2455 struct tcpcb *tp; 2456 struct icmp6_hdr *icmp6; 2457 struct ip6ctlparam *ip6cp = NULL; 2458 const struct sockaddr_in6 *sa6_src = NULL; 2459 struct in_conninfo inc; 2460 struct epoch_tracker et; 2461 struct tcp_ports { 2462 uint16_t th_sport; 2463 uint16_t th_dport; 2464 } t_ports; 2465 tcp_seq icmp_tcp_seq; 2466 unsigned int mtu; 2467 unsigned int off; 2468 2469 if (sa->sa_family != AF_INET6 || 2470 sa->sa_len != sizeof(struct sockaddr_in6)) 2471 return; 2472 2473 /* if the parameter is from icmp6, decode it. */ 2474 if (d != NULL) { 2475 ip6cp = (struct ip6ctlparam *)d; 2476 icmp6 = ip6cp->ip6c_icmp6; 2477 m = ip6cp->ip6c_m; 2478 ip6 = ip6cp->ip6c_ip6; 2479 off = ip6cp->ip6c_off; 2480 sa6_src = ip6cp->ip6c_src; 2481 dst = ip6cp->ip6c_finaldst; 2482 } else { 2483 m = NULL; 2484 ip6 = NULL; 2485 off = 0; /* fool gcc */ 2486 sa6_src = &sa6_any; 2487 dst = NULL; 2488 } 2489 2490 if (cmd == PRC_MSGSIZE) 2491 notify = tcp_mtudisc_notify; 2492 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2493 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2494 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2495 notify = tcp_drop_syn_sent; 2496 2497 /* 2498 * Hostdead is ugly because it goes linearly through all PCBs. 2499 * XXX: We never get this from ICMP, otherwise it makes an 2500 * excellent DoS attack on machines with many connections. 2501 */ 2502 else if (cmd == PRC_HOSTDEAD) 2503 ip6 = NULL; 2504 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2505 return; 2506 2507 if (ip6 == NULL) { 2508 in6_pcbnotify(&V_tcbinfo, sa, 0, 2509 (const struct sockaddr *)sa6_src, 2510 0, cmd, NULL, notify); 2511 return; 2512 } 2513 2514 /* Check if we can safely get the ports from the tcp hdr */ 2515 if (m == NULL || 2516 (m->m_pkthdr.len < 2517 (int32_t) (off + sizeof(struct tcp_ports)))) { 2518 return; 2519 } 2520 bzero(&t_ports, sizeof(struct tcp_ports)); 2521 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2522 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2523 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2524 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2525 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2526 /* signal EHOSTDOWN, as it flushes the cached route */ 2527 inp = (*notify)(inp, EHOSTDOWN); 2528 goto out; 2529 } 2530 off += sizeof(struct tcp_ports); 2531 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2532 goto out; 2533 } 2534 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2535 if (inp != NULL) { 2536 if (!(inp->inp_flags & INP_TIMEWAIT) && 2537 !(inp->inp_flags & INP_DROPPED) && 2538 !(inp->inp_socket == NULL)) { 2539 tp = intotcpcb(inp); 2540 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2541 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2542 if (cmd == PRC_MSGSIZE) { 2543 /* 2544 * MTU discovery: 2545 * If we got a needfrag set the MTU 2546 * in the route to the suggested new 2547 * value (if given) and then notify. 2548 */ 2549 mtu = ntohl(icmp6->icmp6_mtu); 2550 /* 2551 * If no alternative MTU was 2552 * proposed, or the proposed 2553 * MTU was too small, set to 2554 * the min. 2555 */ 2556 if (mtu < IPV6_MMTU) 2557 mtu = IPV6_MMTU - 8; 2558 bzero(&inc, sizeof(inc)); 2559 inc.inc_fibnum = M_GETFIB(m); 2560 inc.inc_flags |= INC_ISIPV6; 2561 inc.inc6_faddr = *dst; 2562 if (in6_setscope(&inc.inc6_faddr, 2563 m->m_pkthdr.rcvif, NULL)) 2564 goto out; 2565 /* 2566 * Only process the offered MTU if it 2567 * is smaller than the current one. 2568 */ 2569 if (mtu < tp->t_maxseg + 2570 sizeof (struct tcphdr) + 2571 sizeof (struct ip6_hdr)) { 2572 tcp_hc_updatemtu(&inc, mtu); 2573 tcp_mtudisc(inp, mtu); 2574 ICMP6STAT_INC(icp6s_pmtuchg); 2575 } 2576 } else 2577 inp = (*notify)(inp, 2578 inet6ctlerrmap[cmd]); 2579 } 2580 } 2581 } else { 2582 bzero(&inc, sizeof(inc)); 2583 inc.inc_fibnum = M_GETFIB(m); 2584 inc.inc_flags |= INC_ISIPV6; 2585 inc.inc_fport = t_ports.th_dport; 2586 inc.inc_lport = t_ports.th_sport; 2587 inc.inc6_faddr = *dst; 2588 inc.inc6_laddr = ip6->ip6_src; 2589 syncache_unreach(&inc, icmp_tcp_seq); 2590 } 2591 out: 2592 if (inp != NULL) 2593 INP_WUNLOCK(inp); 2594 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2595 } 2596 #endif /* INET6 */ 2597 2598 static uint32_t 2599 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2600 { 2601 MD5_CTX ctx; 2602 uint32_t hash[4]; 2603 2604 MD5Init(&ctx); 2605 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2606 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2607 switch (inc->inc_flags & INC_ISIPV6) { 2608 #ifdef INET 2609 case 0: 2610 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2611 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2612 break; 2613 #endif 2614 #ifdef INET6 2615 case INC_ISIPV6: 2616 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2617 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2618 break; 2619 #endif 2620 } 2621 MD5Update(&ctx, key, len); 2622 MD5Final((unsigned char *)hash, &ctx); 2623 2624 return (hash[0]); 2625 } 2626 2627 uint32_t 2628 tcp_new_ts_offset(struct in_conninfo *inc) 2629 { 2630 return (tcp_keyed_hash(inc, V_ts_offset_secret, 2631 sizeof(V_ts_offset_secret))); 2632 } 2633 2634 /* 2635 * Following is where TCP initial sequence number generation occurs. 2636 * 2637 * There are two places where we must use initial sequence numbers: 2638 * 1. In SYN-ACK packets. 2639 * 2. In SYN packets. 2640 * 2641 * All ISNs for SYN-ACK packets are generated by the syncache. See 2642 * tcp_syncache.c for details. 2643 * 2644 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2645 * depends on this property. In addition, these ISNs should be 2646 * unguessable so as to prevent connection hijacking. To satisfy 2647 * the requirements of this situation, the algorithm outlined in 2648 * RFC 1948 is used, with only small modifications. 2649 * 2650 * Implementation details: 2651 * 2652 * Time is based off the system timer, and is corrected so that it 2653 * increases by one megabyte per second. This allows for proper 2654 * recycling on high speed LANs while still leaving over an hour 2655 * before rollover. 2656 * 2657 * As reading the *exact* system time is too expensive to be done 2658 * whenever setting up a TCP connection, we increment the time 2659 * offset in two ways. First, a small random positive increment 2660 * is added to isn_offset for each connection that is set up. 2661 * Second, the function tcp_isn_tick fires once per clock tick 2662 * and increments isn_offset as necessary so that sequence numbers 2663 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2664 * random positive increments serve only to ensure that the same 2665 * exact sequence number is never sent out twice (as could otherwise 2666 * happen when a port is recycled in less than the system tick 2667 * interval.) 2668 * 2669 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2670 * between seeding of isn_secret. This is normally set to zero, 2671 * as reseeding should not be necessary. 2672 * 2673 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2674 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2675 * general, this means holding an exclusive (write) lock. 2676 */ 2677 2678 #define ISN_BYTES_PER_SECOND 1048576 2679 #define ISN_STATIC_INCREMENT 4096 2680 #define ISN_RANDOM_INCREMENT (4096 - 1) 2681 #define ISN_SECRET_LENGTH 32 2682 2683 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2684 VNET_DEFINE_STATIC(int, isn_last); 2685 VNET_DEFINE_STATIC(int, isn_last_reseed); 2686 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2687 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2688 2689 #define V_isn_secret VNET(isn_secret) 2690 #define V_isn_last VNET(isn_last) 2691 #define V_isn_last_reseed VNET(isn_last_reseed) 2692 #define V_isn_offset VNET(isn_offset) 2693 #define V_isn_offset_old VNET(isn_offset_old) 2694 2695 tcp_seq 2696 tcp_new_isn(struct in_conninfo *inc) 2697 { 2698 tcp_seq new_isn; 2699 u_int32_t projected_offset; 2700 2701 ISN_LOCK(); 2702 /* Seed if this is the first use, reseed if requested. */ 2703 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2704 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2705 < (u_int)ticks))) { 2706 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2707 V_isn_last_reseed = ticks; 2708 } 2709 2710 /* Compute the md5 hash and return the ISN. */ 2711 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2712 sizeof(V_isn_secret)); 2713 V_isn_offset += ISN_STATIC_INCREMENT + 2714 (arc4random() & ISN_RANDOM_INCREMENT); 2715 if (ticks != V_isn_last) { 2716 projected_offset = V_isn_offset_old + 2717 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2718 if (SEQ_GT(projected_offset, V_isn_offset)) 2719 V_isn_offset = projected_offset; 2720 V_isn_offset_old = V_isn_offset; 2721 V_isn_last = ticks; 2722 } 2723 new_isn += V_isn_offset; 2724 ISN_UNLOCK(); 2725 return (new_isn); 2726 } 2727 2728 /* 2729 * When a specific ICMP unreachable message is received and the 2730 * connection state is SYN-SENT, drop the connection. This behavior 2731 * is controlled by the icmp_may_rst sysctl. 2732 */ 2733 struct inpcb * 2734 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2735 { 2736 struct tcpcb *tp; 2737 2738 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2739 INP_WLOCK_ASSERT(inp); 2740 2741 if ((inp->inp_flags & INP_TIMEWAIT) || 2742 (inp->inp_flags & INP_DROPPED)) 2743 return (inp); 2744 2745 tp = intotcpcb(inp); 2746 if (tp->t_state != TCPS_SYN_SENT) 2747 return (inp); 2748 2749 if (IS_FASTOPEN(tp->t_flags)) 2750 tcp_fastopen_disable_path(tp); 2751 2752 tp = tcp_drop(tp, errno); 2753 if (tp != NULL) 2754 return (inp); 2755 else 2756 return (NULL); 2757 } 2758 2759 /* 2760 * When `need fragmentation' ICMP is received, update our idea of the MSS 2761 * based on the new value. Also nudge TCP to send something, since we 2762 * know the packet we just sent was dropped. 2763 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2764 */ 2765 static struct inpcb * 2766 tcp_mtudisc_notify(struct inpcb *inp, int error) 2767 { 2768 2769 tcp_mtudisc(inp, -1); 2770 return (inp); 2771 } 2772 2773 static void 2774 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2775 { 2776 struct tcpcb *tp; 2777 struct socket *so; 2778 2779 INP_WLOCK_ASSERT(inp); 2780 if ((inp->inp_flags & INP_TIMEWAIT) || 2781 (inp->inp_flags & INP_DROPPED)) 2782 return; 2783 2784 tp = intotcpcb(inp); 2785 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2786 2787 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2788 2789 so = inp->inp_socket; 2790 SOCKBUF_LOCK(&so->so_snd); 2791 /* If the mss is larger than the socket buffer, decrease the mss. */ 2792 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2793 tp->t_maxseg = so->so_snd.sb_hiwat; 2794 SOCKBUF_UNLOCK(&so->so_snd); 2795 2796 TCPSTAT_INC(tcps_mturesent); 2797 tp->t_rtttime = 0; 2798 tp->snd_nxt = tp->snd_una; 2799 tcp_free_sackholes(tp); 2800 tp->snd_recover = tp->snd_max; 2801 if (tp->t_flags & TF_SACK_PERMIT) 2802 EXIT_FASTRECOVERY(tp->t_flags); 2803 tp->t_fb->tfb_tcp_output(tp); 2804 } 2805 2806 #ifdef INET 2807 /* 2808 * Look-up the routing entry to the peer of this inpcb. If no route 2809 * is found and it cannot be allocated, then return 0. This routine 2810 * is called by TCP routines that access the rmx structure and by 2811 * tcp_mss_update to get the peer/interface MTU. 2812 */ 2813 uint32_t 2814 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2815 { 2816 struct nhop4_extended nh4; 2817 struct ifnet *ifp; 2818 uint32_t maxmtu = 0; 2819 2820 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2821 2822 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2823 2824 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2825 NHR_REF, 0, &nh4) != 0) 2826 return (0); 2827 2828 ifp = nh4.nh_ifp; 2829 maxmtu = nh4.nh_mtu; 2830 2831 /* Report additional interface capabilities. */ 2832 if (cap != NULL) { 2833 if (ifp->if_capenable & IFCAP_TSO4 && 2834 ifp->if_hwassist & CSUM_TSO) { 2835 cap->ifcap |= CSUM_TSO; 2836 cap->tsomax = ifp->if_hw_tsomax; 2837 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2838 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2839 } 2840 } 2841 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2842 } 2843 return (maxmtu); 2844 } 2845 #endif /* INET */ 2846 2847 #ifdef INET6 2848 uint32_t 2849 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2850 { 2851 struct nhop6_extended nh6; 2852 struct in6_addr dst6; 2853 uint32_t scopeid; 2854 struct ifnet *ifp; 2855 uint32_t maxmtu = 0; 2856 2857 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2858 2859 if (inc->inc_flags & INC_IPV6MINMTU) 2860 return (IPV6_MMTU); 2861 2862 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2863 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2864 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2865 0, &nh6) != 0) 2866 return (0); 2867 2868 ifp = nh6.nh_ifp; 2869 maxmtu = nh6.nh_mtu; 2870 2871 /* Report additional interface capabilities. */ 2872 if (cap != NULL) { 2873 if (ifp->if_capenable & IFCAP_TSO6 && 2874 ifp->if_hwassist & CSUM_TSO) { 2875 cap->ifcap |= CSUM_TSO; 2876 cap->tsomax = ifp->if_hw_tsomax; 2877 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2878 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2879 } 2880 } 2881 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2882 } 2883 2884 return (maxmtu); 2885 } 2886 #endif /* INET6 */ 2887 2888 /* 2889 * Calculate effective SMSS per RFC5681 definition for a given TCP 2890 * connection at its current state, taking into account SACK and etc. 2891 */ 2892 u_int 2893 tcp_maxseg(const struct tcpcb *tp) 2894 { 2895 u_int optlen; 2896 2897 if (tp->t_flags & TF_NOOPT) 2898 return (tp->t_maxseg); 2899 2900 /* 2901 * Here we have a simplified code from tcp_addoptions(), 2902 * without a proper loop, and having most of paddings hardcoded. 2903 * We might make mistakes with padding here in some edge cases, 2904 * but this is harmless, since result of tcp_maxseg() is used 2905 * only in cwnd and ssthresh estimations. 2906 */ 2907 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2908 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2909 if (tp->t_flags & TF_RCVD_TSTMP) 2910 optlen = TCPOLEN_TSTAMP_APPA; 2911 else 2912 optlen = 0; 2913 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2914 if (tp->t_flags & TF_SIGNATURE) 2915 optlen += PAD(TCPOLEN_SIGNATURE); 2916 #endif 2917 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2918 optlen += TCPOLEN_SACKHDR; 2919 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2920 optlen = PAD(optlen); 2921 } 2922 } else { 2923 if (tp->t_flags & TF_REQ_TSTMP) 2924 optlen = TCPOLEN_TSTAMP_APPA; 2925 else 2926 optlen = PAD(TCPOLEN_MAXSEG); 2927 if (tp->t_flags & TF_REQ_SCALE) 2928 optlen += PAD(TCPOLEN_WINDOW); 2929 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2930 if (tp->t_flags & TF_SIGNATURE) 2931 optlen += PAD(TCPOLEN_SIGNATURE); 2932 #endif 2933 if (tp->t_flags & TF_SACK_PERMIT) 2934 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2935 } 2936 #undef PAD 2937 optlen = min(optlen, TCP_MAXOLEN); 2938 return (tp->t_maxseg - optlen); 2939 } 2940 2941 static int 2942 sysctl_drop(SYSCTL_HANDLER_ARGS) 2943 { 2944 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2945 struct sockaddr_storage addrs[2]; 2946 struct inpcb *inp; 2947 struct tcpcb *tp; 2948 struct tcptw *tw; 2949 struct sockaddr_in *fin, *lin; 2950 struct epoch_tracker et; 2951 #ifdef INET6 2952 struct sockaddr_in6 *fin6, *lin6; 2953 #endif 2954 int error; 2955 2956 inp = NULL; 2957 fin = lin = NULL; 2958 #ifdef INET6 2959 fin6 = lin6 = NULL; 2960 #endif 2961 error = 0; 2962 2963 if (req->oldptr != NULL || req->oldlen != 0) 2964 return (EINVAL); 2965 if (req->newptr == NULL) 2966 return (EPERM); 2967 if (req->newlen < sizeof(addrs)) 2968 return (ENOMEM); 2969 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2970 if (error) 2971 return (error); 2972 2973 switch (addrs[0].ss_family) { 2974 #ifdef INET6 2975 case AF_INET6: 2976 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2977 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2978 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2979 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2980 return (EINVAL); 2981 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2982 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2983 return (EINVAL); 2984 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2985 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2986 fin = (struct sockaddr_in *)&addrs[0]; 2987 lin = (struct sockaddr_in *)&addrs[1]; 2988 break; 2989 } 2990 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2991 if (error) 2992 return (error); 2993 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2994 if (error) 2995 return (error); 2996 break; 2997 #endif 2998 #ifdef INET 2999 case AF_INET: 3000 fin = (struct sockaddr_in *)&addrs[0]; 3001 lin = (struct sockaddr_in *)&addrs[1]; 3002 if (fin->sin_len != sizeof(struct sockaddr_in) || 3003 lin->sin_len != sizeof(struct sockaddr_in)) 3004 return (EINVAL); 3005 break; 3006 #endif 3007 default: 3008 return (EINVAL); 3009 } 3010 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3011 switch (addrs[0].ss_family) { 3012 #ifdef INET6 3013 case AF_INET6: 3014 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3015 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3016 INPLOOKUP_WLOCKPCB, NULL); 3017 break; 3018 #endif 3019 #ifdef INET 3020 case AF_INET: 3021 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3022 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3023 break; 3024 #endif 3025 } 3026 if (inp != NULL) { 3027 if (inp->inp_flags & INP_TIMEWAIT) { 3028 /* 3029 * XXXRW: There currently exists a state where an 3030 * inpcb is present, but its timewait state has been 3031 * discarded. For now, don't allow dropping of this 3032 * type of inpcb. 3033 */ 3034 tw = intotw(inp); 3035 if (tw != NULL) 3036 tcp_twclose(tw, 0); 3037 else 3038 INP_WUNLOCK(inp); 3039 } else if (!(inp->inp_flags & INP_DROPPED) && 3040 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3041 tp = intotcpcb(inp); 3042 tp = tcp_drop(tp, ECONNABORTED); 3043 if (tp != NULL) 3044 INP_WUNLOCK(inp); 3045 } else 3046 INP_WUNLOCK(inp); 3047 } else 3048 error = ESRCH; 3049 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3050 return (error); 3051 } 3052 3053 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3054 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3055 0, sysctl_drop, "", "Drop TCP connection"); 3056 3057 /* 3058 * Generate a standardized TCP log line for use throughout the 3059 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3060 * allow use in the interrupt context. 3061 * 3062 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3063 * NB: The function may return NULL if memory allocation failed. 3064 * 3065 * Due to header inclusion and ordering limitations the struct ip 3066 * and ip6_hdr pointers have to be passed as void pointers. 3067 */ 3068 char * 3069 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3070 const void *ip6hdr) 3071 { 3072 3073 /* Is logging enabled? */ 3074 if (tcp_log_in_vain == 0) 3075 return (NULL); 3076 3077 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3078 } 3079 3080 char * 3081 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3082 const void *ip6hdr) 3083 { 3084 3085 /* Is logging enabled? */ 3086 if (tcp_log_debug == 0) 3087 return (NULL); 3088 3089 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3090 } 3091 3092 static char * 3093 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3094 const void *ip6hdr) 3095 { 3096 char *s, *sp; 3097 size_t size; 3098 struct ip *ip; 3099 #ifdef INET6 3100 const struct ip6_hdr *ip6; 3101 3102 ip6 = (const struct ip6_hdr *)ip6hdr; 3103 #endif /* INET6 */ 3104 ip = (struct ip *)ip4hdr; 3105 3106 /* 3107 * The log line looks like this: 3108 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3109 */ 3110 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3111 sizeof(PRINT_TH_FLAGS) + 1 + 3112 #ifdef INET6 3113 2 * INET6_ADDRSTRLEN; 3114 #else 3115 2 * INET_ADDRSTRLEN; 3116 #endif /* INET6 */ 3117 3118 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3119 if (s == NULL) 3120 return (NULL); 3121 3122 strcat(s, "TCP: ["); 3123 sp = s + strlen(s); 3124 3125 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3126 inet_ntoa_r(inc->inc_faddr, sp); 3127 sp = s + strlen(s); 3128 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3129 sp = s + strlen(s); 3130 inet_ntoa_r(inc->inc_laddr, sp); 3131 sp = s + strlen(s); 3132 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3133 #ifdef INET6 3134 } else if (inc) { 3135 ip6_sprintf(sp, &inc->inc6_faddr); 3136 sp = s + strlen(s); 3137 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3138 sp = s + strlen(s); 3139 ip6_sprintf(sp, &inc->inc6_laddr); 3140 sp = s + strlen(s); 3141 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3142 } else if (ip6 && th) { 3143 ip6_sprintf(sp, &ip6->ip6_src); 3144 sp = s + strlen(s); 3145 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3146 sp = s + strlen(s); 3147 ip6_sprintf(sp, &ip6->ip6_dst); 3148 sp = s + strlen(s); 3149 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3150 #endif /* INET6 */ 3151 #ifdef INET 3152 } else if (ip && th) { 3153 inet_ntoa_r(ip->ip_src, sp); 3154 sp = s + strlen(s); 3155 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3156 sp = s + strlen(s); 3157 inet_ntoa_r(ip->ip_dst, sp); 3158 sp = s + strlen(s); 3159 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3160 #endif /* INET */ 3161 } else { 3162 free(s, M_TCPLOG); 3163 return (NULL); 3164 } 3165 sp = s + strlen(s); 3166 if (th) 3167 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3168 if (*(s + size - 1) != '\0') 3169 panic("%s: string too long", __func__); 3170 return (s); 3171 } 3172 3173 /* 3174 * A subroutine which makes it easy to track TCP state changes with DTrace. 3175 * This function shouldn't be called for t_state initializations that don't 3176 * correspond to actual TCP state transitions. 3177 */ 3178 void 3179 tcp_state_change(struct tcpcb *tp, int newstate) 3180 { 3181 #if defined(KDTRACE_HOOKS) 3182 int pstate = tp->t_state; 3183 #endif 3184 3185 TCPSTATES_DEC(tp->t_state); 3186 TCPSTATES_INC(newstate); 3187 tp->t_state = newstate; 3188 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3189 } 3190 3191 /* 3192 * Create an external-format (``xtcpcb'') structure using the information in 3193 * the kernel-format tcpcb structure pointed to by tp. This is done to 3194 * reduce the spew of irrelevant information over this interface, to isolate 3195 * user code from changes in the kernel structure, and potentially to provide 3196 * information-hiding if we decide that some of this information should be 3197 * hidden from users. 3198 */ 3199 void 3200 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3201 { 3202 struct tcpcb *tp = intotcpcb(inp); 3203 sbintime_t now; 3204 3205 bzero(xt, sizeof(*xt)); 3206 if (inp->inp_flags & INP_TIMEWAIT) { 3207 xt->t_state = TCPS_TIME_WAIT; 3208 } else { 3209 xt->t_state = tp->t_state; 3210 xt->t_logstate = tp->t_logstate; 3211 xt->t_flags = tp->t_flags; 3212 xt->t_sndzerowin = tp->t_sndzerowin; 3213 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3214 xt->t_rcvoopack = tp->t_rcvoopack; 3215 3216 now = getsbinuptime(); 3217 #define COPYTIMER(ttt) do { \ 3218 if (callout_active(&tp->t_timers->ttt)) \ 3219 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3220 SBT_1MS; \ 3221 else \ 3222 xt->ttt = 0; \ 3223 } while (0) 3224 COPYTIMER(tt_delack); 3225 COPYTIMER(tt_rexmt); 3226 COPYTIMER(tt_persist); 3227 COPYTIMER(tt_keep); 3228 COPYTIMER(tt_2msl); 3229 #undef COPYTIMER 3230 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3231 3232 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3233 TCP_FUNCTION_NAME_LEN_MAX); 3234 #ifdef TCP_BLACKBOX 3235 (void)tcp_log_get_id(tp, xt->xt_logid); 3236 #endif 3237 } 3238 3239 xt->xt_len = sizeof(struct xtcpcb); 3240 in_pcbtoxinpcb(inp, &xt->xt_inp); 3241 if (inp->inp_socket == NULL) 3242 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3243 } 3244