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 static VNET_DEFINE(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 static VNET_DEFINE(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 static int tcp_default_fb_init(struct tcpcb *tp); 237 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 238 static int tcp_default_handoff_ok(struct tcpcb *tp); 239 static struct inpcb *tcp_notify(struct inpcb *, int); 240 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 241 static void tcp_mtudisc(struct inpcb *, int); 242 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 243 void *ip4hdr, const void *ip6hdr); 244 245 246 static struct tcp_function_block tcp_def_funcblk = { 247 .tfb_tcp_block_name = "freebsd", 248 .tfb_tcp_output = tcp_output, 249 .tfb_tcp_do_segment = tcp_do_segment, 250 .tfb_tcp_ctloutput = tcp_default_ctloutput, 251 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 252 .tfb_tcp_fb_init = tcp_default_fb_init, 253 .tfb_tcp_fb_fini = tcp_default_fb_fini, 254 }; 255 256 int t_functions_inited = 0; 257 static int tcp_fb_cnt = 0; 258 struct tcp_funchead t_functions; 259 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 260 261 static void 262 init_tcp_functions(void) 263 { 264 if (t_functions_inited == 0) { 265 TAILQ_INIT(&t_functions); 266 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 267 t_functions_inited = 1; 268 } 269 } 270 271 static struct tcp_function_block * 272 find_tcp_functions_locked(struct tcp_function_set *fs) 273 { 274 struct tcp_function *f; 275 struct tcp_function_block *blk=NULL; 276 277 TAILQ_FOREACH(f, &t_functions, tf_next) { 278 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 279 blk = f->tf_fb; 280 break; 281 } 282 } 283 return(blk); 284 } 285 286 static struct tcp_function_block * 287 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 288 { 289 struct tcp_function_block *rblk=NULL; 290 struct tcp_function *f; 291 292 TAILQ_FOREACH(f, &t_functions, tf_next) { 293 if (f->tf_fb == blk) { 294 rblk = blk; 295 if (s) { 296 *s = f; 297 } 298 break; 299 } 300 } 301 return (rblk); 302 } 303 304 struct tcp_function_block * 305 find_and_ref_tcp_functions(struct tcp_function_set *fs) 306 { 307 struct tcp_function_block *blk; 308 309 rw_rlock(&tcp_function_lock); 310 blk = find_tcp_functions_locked(fs); 311 if (blk) 312 refcount_acquire(&blk->tfb_refcnt); 313 rw_runlock(&tcp_function_lock); 314 return(blk); 315 } 316 317 struct tcp_function_block * 318 find_and_ref_tcp_fb(struct tcp_function_block *blk) 319 { 320 struct tcp_function_block *rblk; 321 322 rw_rlock(&tcp_function_lock); 323 rblk = find_tcp_fb_locked(blk, NULL); 324 if (rblk) 325 refcount_acquire(&rblk->tfb_refcnt); 326 rw_runlock(&tcp_function_lock); 327 return(rblk); 328 } 329 330 static struct tcp_function_block * 331 find_and_ref_tcp_default_fb(void) 332 { 333 struct tcp_function_block *rblk; 334 335 rw_rlock(&tcp_function_lock); 336 rblk = tcp_func_set_ptr; 337 refcount_acquire(&rblk->tfb_refcnt); 338 rw_runlock(&tcp_function_lock); 339 return (rblk); 340 } 341 342 void 343 tcp_switch_back_to_default(struct tcpcb *tp) 344 { 345 struct tcp_function_block *tfb; 346 347 KASSERT(tp->t_fb != &tcp_def_funcblk, 348 ("%s: called by the built-in default stack", __func__)); 349 350 /* 351 * Release the old stack. This function will either find a new one 352 * or panic. 353 */ 354 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 355 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 356 refcount_release(&tp->t_fb->tfb_refcnt); 357 358 /* 359 * Now, we'll find a new function block to use. 360 * Start by trying the current user-selected 361 * default, unless this stack is the user-selected 362 * default. 363 */ 364 tfb = find_and_ref_tcp_default_fb(); 365 if (tfb == tp->t_fb) { 366 refcount_release(&tfb->tfb_refcnt); 367 tfb = NULL; 368 } 369 /* Does the stack accept this connection? */ 370 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 371 (*tfb->tfb_tcp_handoff_ok)(tp)) { 372 refcount_release(&tfb->tfb_refcnt); 373 tfb = NULL; 374 } 375 /* Try to use that stack. */ 376 if (tfb != NULL) { 377 /* Initialize the new stack. If it succeeds, we are done. */ 378 tp->t_fb = tfb; 379 if (tp->t_fb->tfb_tcp_fb_init == NULL || 380 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 381 return; 382 383 /* 384 * Initialization failed. Release the reference count on 385 * the stack. 386 */ 387 refcount_release(&tfb->tfb_refcnt); 388 } 389 390 /* 391 * If that wasn't feasible, use the built-in default 392 * stack which is not allowed to reject anyone. 393 */ 394 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 395 if (tfb == NULL) { 396 /* there always should be a default */ 397 panic("Can't refer to tcp_def_funcblk"); 398 } 399 if (tfb->tfb_tcp_handoff_ok != NULL) { 400 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 401 /* The default stack cannot say no */ 402 panic("Default stack rejects a new session?"); 403 } 404 } 405 tp->t_fb = tfb; 406 if (tp->t_fb->tfb_tcp_fb_init != NULL && 407 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 408 /* The default stack cannot fail */ 409 panic("Default stack initialization failed"); 410 } 411 } 412 413 static int 414 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 415 { 416 int error=ENOENT; 417 struct tcp_function_set fs; 418 struct tcp_function_block *blk; 419 420 memset(&fs, 0, sizeof(fs)); 421 rw_rlock(&tcp_function_lock); 422 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 423 if (blk) { 424 /* Found him */ 425 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 426 fs.pcbcnt = blk->tfb_refcnt; 427 } 428 rw_runlock(&tcp_function_lock); 429 error = sysctl_handle_string(oidp, fs.function_set_name, 430 sizeof(fs.function_set_name), req); 431 432 /* Check for error or no change */ 433 if (error != 0 || req->newptr == NULL) 434 return(error); 435 436 rw_wlock(&tcp_function_lock); 437 blk = find_tcp_functions_locked(&fs); 438 if ((blk == NULL) || 439 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 440 error = ENOENT; 441 goto done; 442 } 443 tcp_func_set_ptr = blk; 444 done: 445 rw_wunlock(&tcp_function_lock); 446 return (error); 447 } 448 449 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 450 CTLTYPE_STRING | CTLFLAG_RW, 451 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 452 "Set/get the default TCP functions"); 453 454 static int 455 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 456 { 457 int error, cnt, linesz; 458 struct tcp_function *f; 459 char *buffer, *cp; 460 size_t bufsz, outsz; 461 bool alias; 462 463 cnt = 0; 464 rw_rlock(&tcp_function_lock); 465 TAILQ_FOREACH(f, &t_functions, tf_next) { 466 cnt++; 467 } 468 rw_runlock(&tcp_function_lock); 469 470 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 471 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 472 473 error = 0; 474 cp = buffer; 475 476 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 477 "Alias", "PCB count"); 478 cp += linesz; 479 bufsz -= linesz; 480 outsz = linesz; 481 482 rw_rlock(&tcp_function_lock); 483 TAILQ_FOREACH(f, &t_functions, tf_next) { 484 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 485 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 486 f->tf_fb->tfb_tcp_block_name, 487 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 488 alias ? f->tf_name : "-", 489 f->tf_fb->tfb_refcnt); 490 if (linesz >= bufsz) { 491 error = EOVERFLOW; 492 break; 493 } 494 cp += linesz; 495 bufsz -= linesz; 496 outsz += linesz; 497 } 498 rw_runlock(&tcp_function_lock); 499 if (error == 0) 500 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 501 free(buffer, M_TEMP); 502 return (error); 503 } 504 505 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 506 CTLTYPE_STRING|CTLFLAG_RD, 507 NULL, 0, sysctl_net_inet_list_available, "A", 508 "list available TCP Function sets"); 509 510 /* 511 * Exports one (struct tcp_function_info) for each alias/name. 512 */ 513 static int 514 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 515 { 516 int cnt, error; 517 struct tcp_function *f; 518 struct tcp_function_info tfi; 519 520 /* 521 * We don't allow writes. 522 */ 523 if (req->newptr != NULL) 524 return (EINVAL); 525 526 /* 527 * Wire the old buffer so we can directly copy the functions to 528 * user space without dropping the lock. 529 */ 530 if (req->oldptr != NULL) { 531 error = sysctl_wire_old_buffer(req, 0); 532 if (error) 533 return (error); 534 } 535 536 /* 537 * Walk the list and copy out matching entries. If INVARIANTS 538 * is compiled in, also walk the list to verify the length of 539 * the list matches what we have recorded. 540 */ 541 rw_rlock(&tcp_function_lock); 542 543 cnt = 0; 544 #ifndef INVARIANTS 545 if (req->oldptr == NULL) { 546 cnt = tcp_fb_cnt; 547 goto skip_loop; 548 } 549 #endif 550 TAILQ_FOREACH(f, &t_functions, tf_next) { 551 #ifdef INVARIANTS 552 cnt++; 553 #endif 554 if (req->oldptr != NULL) { 555 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 556 tfi.tfi_id = f->tf_fb->tfb_id; 557 (void)strncpy(tfi.tfi_alias, f->tf_name, 558 TCP_FUNCTION_NAME_LEN_MAX); 559 tfi.tfi_alias[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 560 (void)strncpy(tfi.tfi_name, 561 f->tf_fb->tfb_tcp_block_name, 562 TCP_FUNCTION_NAME_LEN_MAX); 563 tfi.tfi_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 564 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 565 /* 566 * Don't stop on error, as that is the 567 * mechanism we use to accumulate length 568 * information if the buffer was too short. 569 */ 570 } 571 } 572 KASSERT(cnt == tcp_fb_cnt, 573 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 574 #ifndef INVARIANTS 575 skip_loop: 576 #endif 577 rw_runlock(&tcp_function_lock); 578 if (req->oldptr == NULL) 579 error = SYSCTL_OUT(req, NULL, 580 (cnt + 1) * sizeof(struct tcp_function_info)); 581 582 return (error); 583 } 584 585 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 586 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 587 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 588 "List TCP function block name-to-ID mappings"); 589 590 /* 591 * tfb_tcp_handoff_ok() function for the default stack. 592 * Note that we'll basically try to take all comers. 593 */ 594 static int 595 tcp_default_handoff_ok(struct tcpcb *tp) 596 { 597 598 return (0); 599 } 600 601 /* 602 * tfb_tcp_fb_init() function for the default stack. 603 * 604 * This handles making sure we have appropriate timers set if you are 605 * transitioning a socket that has some amount of setup done. 606 * 607 * The init() fuction from the default can *never* return non-zero i.e. 608 * it is required to always succeed since it is the stack of last resort! 609 */ 610 static int 611 tcp_default_fb_init(struct tcpcb *tp) 612 { 613 614 struct socket *so; 615 616 INP_WLOCK_ASSERT(tp->t_inpcb); 617 618 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 619 ("%s: connection %p in unexpected state %d", __func__, tp, 620 tp->t_state)); 621 622 /* 623 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 624 * know what to do for unexpected states (which includes TIME_WAIT). 625 */ 626 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 627 return (0); 628 629 /* 630 * Make sure some kind of transmission timer is set if there is 631 * outstanding data. 632 */ 633 so = tp->t_inpcb->inp_socket; 634 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 635 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 636 tcp_timer_active(tp, TT_PERSIST))) { 637 /* 638 * If the session has established and it looks like it should 639 * be in the persist state, set the persist timer. Otherwise, 640 * set the retransmit timer. 641 */ 642 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 643 (int32_t)(tp->snd_nxt - tp->snd_una) < 644 (int32_t)sbavail(&so->so_snd)) 645 tcp_setpersist(tp); 646 else 647 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 648 } 649 650 /* All non-embryonic sessions get a keepalive timer. */ 651 if (!tcp_timer_active(tp, TT_KEEP)) 652 tcp_timer_activate(tp, TT_KEEP, 653 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 654 TP_KEEPINIT(tp)); 655 656 return (0); 657 } 658 659 /* 660 * tfb_tcp_fb_fini() function for the default stack. 661 * 662 * This changes state as necessary (or prudent) to prepare for another stack 663 * to assume responsibility for the connection. 664 */ 665 static void 666 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 667 { 668 669 INP_WLOCK_ASSERT(tp->t_inpcb); 670 return; 671 } 672 673 /* 674 * Target size of TCP PCB hash tables. Must be a power of two. 675 * 676 * Note that this can be overridden by the kernel environment 677 * variable net.inet.tcp.tcbhashsize 678 */ 679 #ifndef TCBHASHSIZE 680 #define TCBHASHSIZE 0 681 #endif 682 683 /* 684 * XXX 685 * Callouts should be moved into struct tcp directly. They are currently 686 * separate because the tcpcb structure is exported to userland for sysctl 687 * parsing purposes, which do not know about callouts. 688 */ 689 struct tcpcb_mem { 690 struct tcpcb tcb; 691 struct tcp_timer tt; 692 struct cc_var ccv; 693 #ifdef TCP_HHOOK 694 struct osd osd; 695 #endif 696 }; 697 698 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 699 #define V_tcpcb_zone VNET(tcpcb_zone) 700 701 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 702 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 703 704 static struct mtx isn_mtx; 705 706 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 707 #define ISN_LOCK() mtx_lock(&isn_mtx) 708 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 709 710 /* 711 * TCP initialization. 712 */ 713 static void 714 tcp_zone_change(void *tag) 715 { 716 717 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 718 uma_zone_set_max(V_tcpcb_zone, maxsockets); 719 tcp_tw_zone_change(); 720 } 721 722 static int 723 tcp_inpcb_init(void *mem, int size, int flags) 724 { 725 struct inpcb *inp = mem; 726 727 INP_LOCK_INIT(inp, "inp", "tcpinp"); 728 return (0); 729 } 730 731 /* 732 * Take a value and get the next power of 2 that doesn't overflow. 733 * Used to size the tcp_inpcb hash buckets. 734 */ 735 static int 736 maketcp_hashsize(int size) 737 { 738 int hashsize; 739 740 /* 741 * auto tune. 742 * get the next power of 2 higher than maxsockets. 743 */ 744 hashsize = 1 << fls(size); 745 /* catch overflow, and just go one power of 2 smaller */ 746 if (hashsize < size) { 747 hashsize = 1 << (fls(size) - 1); 748 } 749 return (hashsize); 750 } 751 752 static volatile int next_tcp_stack_id = 1; 753 754 /* 755 * Register a TCP function block with the name provided in the names 756 * array. (Note that this function does NOT automatically register 757 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 758 * explicitly include blk->tfb_tcp_block_name in the list of names if 759 * you wish to register the stack with that name.) 760 * 761 * Either all name registrations will succeed or all will fail. If 762 * a name registration fails, the function will update the num_names 763 * argument to point to the array index of the name that encountered 764 * the failure. 765 * 766 * Returns 0 on success, or an error code on failure. 767 */ 768 int 769 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 770 const char *names[], int *num_names) 771 { 772 struct tcp_function *n; 773 struct tcp_function_set fs; 774 int error, i; 775 776 KASSERT(names != NULL && *num_names > 0, 777 ("%s: Called with 0-length name list", __func__)); 778 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 779 780 if (t_functions_inited == 0) { 781 init_tcp_functions(); 782 } 783 if ((blk->tfb_tcp_output == NULL) || 784 (blk->tfb_tcp_do_segment == NULL) || 785 (blk->tfb_tcp_ctloutput == NULL) || 786 (strlen(blk->tfb_tcp_block_name) == 0)) { 787 /* 788 * These functions are required and you 789 * need a name. 790 */ 791 *num_names = 0; 792 return (EINVAL); 793 } 794 if (blk->tfb_tcp_timer_stop_all || 795 blk->tfb_tcp_timer_activate || 796 blk->tfb_tcp_timer_active || 797 blk->tfb_tcp_timer_stop) { 798 /* 799 * If you define one timer function you 800 * must have them all. 801 */ 802 if ((blk->tfb_tcp_timer_stop_all == NULL) || 803 (blk->tfb_tcp_timer_activate == NULL) || 804 (blk->tfb_tcp_timer_active == NULL) || 805 (blk->tfb_tcp_timer_stop == NULL)) { 806 *num_names = 0; 807 return (EINVAL); 808 } 809 } 810 811 refcount_init(&blk->tfb_refcnt, 0); 812 blk->tfb_flags = 0; 813 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 814 for (i = 0; i < *num_names; i++) { 815 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 816 if (n == NULL) { 817 error = ENOMEM; 818 goto cleanup; 819 } 820 n->tf_fb = blk; 821 822 (void)strncpy(fs.function_set_name, names[i], 823 TCP_FUNCTION_NAME_LEN_MAX); 824 fs.function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 825 rw_wlock(&tcp_function_lock); 826 if (find_tcp_functions_locked(&fs) != NULL) { 827 /* Duplicate name space not allowed */ 828 rw_wunlock(&tcp_function_lock); 829 free(n, M_TCPFUNCTIONS); 830 error = EALREADY; 831 goto cleanup; 832 } 833 (void)strncpy(n->tf_name, names[i], TCP_FUNCTION_NAME_LEN_MAX); 834 n->tf_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 835 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 836 tcp_fb_cnt++; 837 rw_wunlock(&tcp_function_lock); 838 } 839 return(0); 840 841 cleanup: 842 /* 843 * Deregister the names we just added. Because registration failed 844 * for names[i], we don't need to deregister that name. 845 */ 846 *num_names = i; 847 rw_wlock(&tcp_function_lock); 848 while (--i >= 0) { 849 TAILQ_FOREACH(n, &t_functions, tf_next) { 850 if (!strncmp(n->tf_name, names[i], 851 TCP_FUNCTION_NAME_LEN_MAX)) { 852 TAILQ_REMOVE(&t_functions, n, tf_next); 853 tcp_fb_cnt--; 854 n->tf_fb = NULL; 855 free(n, M_TCPFUNCTIONS); 856 break; 857 } 858 } 859 } 860 rw_wunlock(&tcp_function_lock); 861 return (error); 862 } 863 864 /* 865 * Register a TCP function block using the name provided in the name 866 * argument. 867 * 868 * Returns 0 on success, or an error code on failure. 869 */ 870 int 871 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 872 int wait) 873 { 874 const char *name_list[1]; 875 int num_names, rv; 876 877 num_names = 1; 878 if (name != NULL) 879 name_list[0] = name; 880 else 881 name_list[0] = blk->tfb_tcp_block_name; 882 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 883 return (rv); 884 } 885 886 /* 887 * Register a TCP function block using the name defined in 888 * blk->tfb_tcp_block_name. 889 * 890 * Returns 0 on success, or an error code on failure. 891 */ 892 int 893 register_tcp_functions(struct tcp_function_block *blk, int wait) 894 { 895 896 return (register_tcp_functions_as_name(blk, NULL, wait)); 897 } 898 899 /* 900 * Deregister all names associated with a function block. This 901 * functionally removes the function block from use within the system. 902 * 903 * When called with a true quiesce argument, mark the function block 904 * as being removed so no more stacks will use it and determine 905 * whether the removal would succeed. 906 * 907 * When called with a false quiesce argument, actually attempt the 908 * removal. 909 * 910 * When called with a force argument, attempt to switch all TCBs to 911 * use the default stack instead of returning EBUSY. 912 * 913 * Returns 0 on success (or if the removal would succeed, or an error 914 * code on failure. 915 */ 916 int 917 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 918 bool force) 919 { 920 struct tcp_function *f; 921 922 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 923 /* You can't un-register the default */ 924 return (EPERM); 925 } 926 rw_wlock(&tcp_function_lock); 927 if (blk == tcp_func_set_ptr) { 928 /* You can't free the current default */ 929 rw_wunlock(&tcp_function_lock); 930 return (EBUSY); 931 } 932 /* Mark the block so no more stacks can use it. */ 933 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 934 /* 935 * If TCBs are still attached to the stack, attempt to switch them 936 * to the default stack. 937 */ 938 if (force && blk->tfb_refcnt) { 939 struct inpcb *inp; 940 struct tcpcb *tp; 941 VNET_ITERATOR_DECL(vnet_iter); 942 943 rw_wunlock(&tcp_function_lock); 944 945 VNET_LIST_RLOCK(); 946 VNET_FOREACH(vnet_iter) { 947 CURVNET_SET(vnet_iter); 948 INP_INFO_WLOCK(&V_tcbinfo); 949 LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 950 INP_WLOCK(inp); 951 if (inp->inp_flags & INP_TIMEWAIT) { 952 INP_WUNLOCK(inp); 953 continue; 954 } 955 tp = intotcpcb(inp); 956 if (tp == NULL || tp->t_fb != blk) { 957 INP_WUNLOCK(inp); 958 continue; 959 } 960 tcp_switch_back_to_default(tp); 961 INP_WUNLOCK(inp); 962 } 963 INP_INFO_WUNLOCK(&V_tcbinfo); 964 CURVNET_RESTORE(); 965 } 966 VNET_LIST_RUNLOCK(); 967 968 rw_wlock(&tcp_function_lock); 969 } 970 if (blk->tfb_refcnt) { 971 /* TCBs still attached. */ 972 rw_wunlock(&tcp_function_lock); 973 return (EBUSY); 974 } 975 if (quiesce) { 976 /* Skip removal. */ 977 rw_wunlock(&tcp_function_lock); 978 return (0); 979 } 980 /* Remove any function names that map to this function block. */ 981 while (find_tcp_fb_locked(blk, &f) != NULL) { 982 TAILQ_REMOVE(&t_functions, f, tf_next); 983 tcp_fb_cnt--; 984 f->tf_fb = NULL; 985 free(f, M_TCPFUNCTIONS); 986 } 987 rw_wunlock(&tcp_function_lock); 988 return (0); 989 } 990 991 void 992 tcp_init(void) 993 { 994 const char *tcbhash_tuneable; 995 int hashsize; 996 997 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 998 999 #ifdef TCP_HHOOK 1000 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1001 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1002 printf("%s: WARNING: unable to register helper hook\n", __func__); 1003 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1004 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1005 printf("%s: WARNING: unable to register helper hook\n", __func__); 1006 #endif 1007 hashsize = TCBHASHSIZE; 1008 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1009 if (hashsize == 0) { 1010 /* 1011 * Auto tune the hash size based on maxsockets. 1012 * A perfect hash would have a 1:1 mapping 1013 * (hashsize = maxsockets) however it's been 1014 * suggested that O(2) average is better. 1015 */ 1016 hashsize = maketcp_hashsize(maxsockets / 4); 1017 /* 1018 * Our historical default is 512, 1019 * do not autotune lower than this. 1020 */ 1021 if (hashsize < 512) 1022 hashsize = 512; 1023 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1024 printf("%s: %s auto tuned to %d\n", __func__, 1025 tcbhash_tuneable, hashsize); 1026 } 1027 /* 1028 * We require a hashsize to be a power of two. 1029 * Previously if it was not a power of two we would just reset it 1030 * back to 512, which could be a nasty surprise if you did not notice 1031 * the error message. 1032 * Instead what we do is clip it to the closest power of two lower 1033 * than the specified hash value. 1034 */ 1035 if (!powerof2(hashsize)) { 1036 int oldhashsize = hashsize; 1037 1038 hashsize = maketcp_hashsize(hashsize); 1039 /* prevent absurdly low value */ 1040 if (hashsize < 16) 1041 hashsize = 16; 1042 printf("%s: WARNING: TCB hash size not a power of 2, " 1043 "clipped from %d to %d.\n", __func__, oldhashsize, 1044 hashsize); 1045 } 1046 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1047 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1048 1049 /* 1050 * These have to be type stable for the benefit of the timers. 1051 */ 1052 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1053 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1054 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1055 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1056 1057 tcp_tw_init(); 1058 syncache_init(); 1059 tcp_hc_init(); 1060 1061 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1062 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1063 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1064 1065 tcp_fastopen_init(); 1066 1067 /* Skip initialization of globals for non-default instances. */ 1068 if (!IS_DEFAULT_VNET(curvnet)) 1069 return; 1070 1071 tcp_reass_global_init(); 1072 1073 /* XXX virtualize those bellow? */ 1074 tcp_delacktime = TCPTV_DELACK; 1075 tcp_keepinit = TCPTV_KEEP_INIT; 1076 tcp_keepidle = TCPTV_KEEP_IDLE; 1077 tcp_keepintvl = TCPTV_KEEPINTVL; 1078 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1079 tcp_msl = TCPTV_MSL; 1080 tcp_rexmit_min = TCPTV_MIN; 1081 if (tcp_rexmit_min < 1) 1082 tcp_rexmit_min = 1; 1083 tcp_persmin = TCPTV_PERSMIN; 1084 tcp_persmax = TCPTV_PERSMAX; 1085 tcp_rexmit_slop = TCPTV_CPU_VAR; 1086 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1087 tcp_tcbhashsize = hashsize; 1088 /* Setup the tcp function block list */ 1089 init_tcp_functions(); 1090 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1091 #ifdef TCP_BLACKBOX 1092 /* Initialize the TCP logging data. */ 1093 tcp_log_init(); 1094 #endif 1095 1096 if (tcp_soreceive_stream) { 1097 #ifdef INET 1098 tcp_usrreqs.pru_soreceive = soreceive_stream; 1099 #endif 1100 #ifdef INET6 1101 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1102 #endif /* INET6 */ 1103 } 1104 1105 #ifdef INET6 1106 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1107 #else /* INET6 */ 1108 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1109 #endif /* INET6 */ 1110 if (max_protohdr < TCP_MINPROTOHDR) 1111 max_protohdr = TCP_MINPROTOHDR; 1112 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1113 panic("tcp_init"); 1114 #undef TCP_MINPROTOHDR 1115 1116 ISN_LOCK_INIT(); 1117 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1118 SHUTDOWN_PRI_DEFAULT); 1119 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1120 EVENTHANDLER_PRI_ANY); 1121 #ifdef TCPPCAP 1122 tcp_pcap_init(); 1123 #endif 1124 } 1125 1126 #ifdef VIMAGE 1127 static void 1128 tcp_destroy(void *unused __unused) 1129 { 1130 int n; 1131 #ifdef TCP_HHOOK 1132 int error; 1133 #endif 1134 1135 /* 1136 * All our processes are gone, all our sockets should be cleaned 1137 * up, which means, we should be past the tcp_discardcb() calls. 1138 * Sleep to let all tcpcb timers really disappear and cleanup. 1139 */ 1140 for (;;) { 1141 INP_LIST_RLOCK(&V_tcbinfo); 1142 n = V_tcbinfo.ipi_count; 1143 INP_LIST_RUNLOCK(&V_tcbinfo); 1144 if (n == 0) 1145 break; 1146 pause("tcpdes", hz / 10); 1147 } 1148 tcp_hc_destroy(); 1149 syncache_destroy(); 1150 tcp_tw_destroy(); 1151 in_pcbinfo_destroy(&V_tcbinfo); 1152 /* tcp_discardcb() clears the sack_holes up. */ 1153 uma_zdestroy(V_sack_hole_zone); 1154 uma_zdestroy(V_tcpcb_zone); 1155 1156 /* 1157 * Cannot free the zone until all tcpcbs are released as we attach 1158 * the allocations to them. 1159 */ 1160 tcp_fastopen_destroy(); 1161 1162 #ifdef TCP_HHOOK 1163 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1164 if (error != 0) { 1165 printf("%s: WARNING: unable to deregister helper hook " 1166 "type=%d, id=%d: error %d returned\n", __func__, 1167 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1168 } 1169 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1170 if (error != 0) { 1171 printf("%s: WARNING: unable to deregister helper hook " 1172 "type=%d, id=%d: error %d returned\n", __func__, 1173 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1174 } 1175 #endif 1176 } 1177 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1178 #endif 1179 1180 void 1181 tcp_fini(void *xtp) 1182 { 1183 1184 } 1185 1186 /* 1187 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1188 * tcp_template used to store this data in mbufs, but we now recopy it out 1189 * of the tcpcb each time to conserve mbufs. 1190 */ 1191 void 1192 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1193 { 1194 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1195 1196 INP_WLOCK_ASSERT(inp); 1197 1198 #ifdef INET6 1199 if ((inp->inp_vflag & INP_IPV6) != 0) { 1200 struct ip6_hdr *ip6; 1201 1202 ip6 = (struct ip6_hdr *)ip_ptr; 1203 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1204 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1205 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1206 (IPV6_VERSION & IPV6_VERSION_MASK); 1207 ip6->ip6_nxt = IPPROTO_TCP; 1208 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1209 ip6->ip6_src = inp->in6p_laddr; 1210 ip6->ip6_dst = inp->in6p_faddr; 1211 } 1212 #endif /* INET6 */ 1213 #if defined(INET6) && defined(INET) 1214 else 1215 #endif 1216 #ifdef INET 1217 { 1218 struct ip *ip; 1219 1220 ip = (struct ip *)ip_ptr; 1221 ip->ip_v = IPVERSION; 1222 ip->ip_hl = 5; 1223 ip->ip_tos = inp->inp_ip_tos; 1224 ip->ip_len = 0; 1225 ip->ip_id = 0; 1226 ip->ip_off = 0; 1227 ip->ip_ttl = inp->inp_ip_ttl; 1228 ip->ip_sum = 0; 1229 ip->ip_p = IPPROTO_TCP; 1230 ip->ip_src = inp->inp_laddr; 1231 ip->ip_dst = inp->inp_faddr; 1232 } 1233 #endif /* INET */ 1234 th->th_sport = inp->inp_lport; 1235 th->th_dport = inp->inp_fport; 1236 th->th_seq = 0; 1237 th->th_ack = 0; 1238 th->th_x2 = 0; 1239 th->th_off = 5; 1240 th->th_flags = 0; 1241 th->th_win = 0; 1242 th->th_urp = 0; 1243 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1244 } 1245 1246 /* 1247 * Create template to be used to send tcp packets on a connection. 1248 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1249 * use for this function is in keepalives, which use tcp_respond. 1250 */ 1251 struct tcptemp * 1252 tcpip_maketemplate(struct inpcb *inp) 1253 { 1254 struct tcptemp *t; 1255 1256 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1257 if (t == NULL) 1258 return (NULL); 1259 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1260 return (t); 1261 } 1262 1263 /* 1264 * Send a single message to the TCP at address specified by 1265 * the given TCP/IP header. If m == NULL, then we make a copy 1266 * of the tcpiphdr at th and send directly to the addressed host. 1267 * This is used to force keep alive messages out using the TCP 1268 * template for a connection. If flags are given then we send 1269 * a message back to the TCP which originated the segment th, 1270 * and discard the mbuf containing it and any other attached mbufs. 1271 * 1272 * In any case the ack and sequence number of the transmitted 1273 * segment are as specified by the parameters. 1274 * 1275 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1276 */ 1277 void 1278 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1279 tcp_seq ack, tcp_seq seq, int flags) 1280 { 1281 struct tcpopt to; 1282 struct inpcb *inp; 1283 struct ip *ip; 1284 struct mbuf *optm; 1285 struct tcphdr *nth; 1286 u_char *optp; 1287 #ifdef INET6 1288 struct ip6_hdr *ip6; 1289 int isipv6; 1290 #endif /* INET6 */ 1291 int optlen, tlen, win; 1292 bool incl_opts; 1293 1294 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1295 1296 #ifdef INET6 1297 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1298 ip6 = ipgen; 1299 #endif /* INET6 */ 1300 ip = ipgen; 1301 1302 if (tp != NULL) { 1303 inp = tp->t_inpcb; 1304 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1305 INP_WLOCK_ASSERT(inp); 1306 } else 1307 inp = NULL; 1308 1309 incl_opts = false; 1310 win = 0; 1311 if (tp != NULL) { 1312 if (!(flags & TH_RST)) { 1313 win = sbspace(&inp->inp_socket->so_rcv); 1314 if (win > TCP_MAXWIN << tp->rcv_scale) 1315 win = TCP_MAXWIN << tp->rcv_scale; 1316 } 1317 if ((tp->t_flags & TF_NOOPT) == 0) 1318 incl_opts = true; 1319 } 1320 if (m == NULL) { 1321 m = m_gethdr(M_NOWAIT, MT_DATA); 1322 if (m == NULL) 1323 return; 1324 m->m_data += max_linkhdr; 1325 #ifdef INET6 1326 if (isipv6) { 1327 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1328 sizeof(struct ip6_hdr)); 1329 ip6 = mtod(m, struct ip6_hdr *); 1330 nth = (struct tcphdr *)(ip6 + 1); 1331 } else 1332 #endif /* INET6 */ 1333 { 1334 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1335 ip = mtod(m, struct ip *); 1336 nth = (struct tcphdr *)(ip + 1); 1337 } 1338 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1339 flags = TH_ACK; 1340 } else if (!M_WRITABLE(m)) { 1341 struct mbuf *n; 1342 1343 /* Can't reuse 'm', allocate a new mbuf. */ 1344 n = m_gethdr(M_NOWAIT, MT_DATA); 1345 if (n == NULL) { 1346 m_freem(m); 1347 return; 1348 } 1349 1350 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1351 m_freem(m); 1352 m_freem(n); 1353 return; 1354 } 1355 1356 n->m_data += max_linkhdr; 1357 /* m_len is set later */ 1358 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1359 #ifdef INET6 1360 if (isipv6) { 1361 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1362 sizeof(struct ip6_hdr)); 1363 ip6 = mtod(n, struct ip6_hdr *); 1364 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1365 nth = (struct tcphdr *)(ip6 + 1); 1366 } else 1367 #endif /* INET6 */ 1368 { 1369 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1370 ip = mtod(n, struct ip *); 1371 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1372 nth = (struct tcphdr *)(ip + 1); 1373 } 1374 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1375 xchg(nth->th_dport, nth->th_sport, uint16_t); 1376 th = nth; 1377 m_freem(m); 1378 m = n; 1379 } else { 1380 /* 1381 * reuse the mbuf. 1382 * XXX MRT We inherit the FIB, which is lucky. 1383 */ 1384 m_freem(m->m_next); 1385 m->m_next = NULL; 1386 m->m_data = (caddr_t)ipgen; 1387 /* m_len is set later */ 1388 #ifdef INET6 1389 if (isipv6) { 1390 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1391 nth = (struct tcphdr *)(ip6 + 1); 1392 } else 1393 #endif /* INET6 */ 1394 { 1395 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1396 nth = (struct tcphdr *)(ip + 1); 1397 } 1398 if (th != nth) { 1399 /* 1400 * this is usually a case when an extension header 1401 * exists between the IPv6 header and the 1402 * TCP header. 1403 */ 1404 nth->th_sport = th->th_sport; 1405 nth->th_dport = th->th_dport; 1406 } 1407 xchg(nth->th_dport, nth->th_sport, uint16_t); 1408 #undef xchg 1409 } 1410 tlen = 0; 1411 #ifdef INET6 1412 if (isipv6) 1413 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1414 #endif 1415 #if defined(INET) && defined(INET6) 1416 else 1417 #endif 1418 #ifdef INET 1419 tlen = sizeof (struct tcpiphdr); 1420 #endif 1421 #ifdef INVARIANTS 1422 m->m_len = 0; 1423 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1424 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1425 m, tlen, (long)M_TRAILINGSPACE(m))); 1426 #endif 1427 m->m_len = tlen; 1428 to.to_flags = 0; 1429 if (incl_opts) { 1430 /* Make sure we have room. */ 1431 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1432 m->m_next = m_get(M_NOWAIT, MT_DATA); 1433 if (m->m_next) { 1434 optp = mtod(m->m_next, u_char *); 1435 optm = m->m_next; 1436 } else 1437 incl_opts = false; 1438 } else { 1439 optp = (u_char *) (nth + 1); 1440 optm = m; 1441 } 1442 } 1443 if (incl_opts) { 1444 /* Timestamps. */ 1445 if (tp->t_flags & TF_RCVD_TSTMP) { 1446 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1447 to.to_tsecr = tp->ts_recent; 1448 to.to_flags |= TOF_TS; 1449 } 1450 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1451 /* TCP-MD5 (RFC2385). */ 1452 if (tp->t_flags & TF_SIGNATURE) 1453 to.to_flags |= TOF_SIGNATURE; 1454 #endif 1455 /* Add the options. */ 1456 tlen += optlen = tcp_addoptions(&to, optp); 1457 1458 /* Update m_len in the correct mbuf. */ 1459 optm->m_len += optlen; 1460 } else 1461 optlen = 0; 1462 #ifdef INET6 1463 if (isipv6) { 1464 ip6->ip6_flow = 0; 1465 ip6->ip6_vfc = IPV6_VERSION; 1466 ip6->ip6_nxt = IPPROTO_TCP; 1467 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1468 } 1469 #endif 1470 #if defined(INET) && defined(INET6) 1471 else 1472 #endif 1473 #ifdef INET 1474 { 1475 ip->ip_len = htons(tlen); 1476 ip->ip_ttl = V_ip_defttl; 1477 if (V_path_mtu_discovery) 1478 ip->ip_off |= htons(IP_DF); 1479 } 1480 #endif 1481 m->m_pkthdr.len = tlen; 1482 m->m_pkthdr.rcvif = NULL; 1483 #ifdef MAC 1484 if (inp != NULL) { 1485 /* 1486 * Packet is associated with a socket, so allow the 1487 * label of the response to reflect the socket label. 1488 */ 1489 INP_WLOCK_ASSERT(inp); 1490 mac_inpcb_create_mbuf(inp, m); 1491 } else { 1492 /* 1493 * Packet is not associated with a socket, so possibly 1494 * update the label in place. 1495 */ 1496 mac_netinet_tcp_reply(m); 1497 } 1498 #endif 1499 nth->th_seq = htonl(seq); 1500 nth->th_ack = htonl(ack); 1501 nth->th_x2 = 0; 1502 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1503 nth->th_flags = flags; 1504 if (tp != NULL) 1505 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1506 else 1507 nth->th_win = htons((u_short)win); 1508 nth->th_urp = 0; 1509 1510 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1511 if (to.to_flags & TOF_SIGNATURE) { 1512 if (!TCPMD5_ENABLED() || 1513 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1514 m_freem(m); 1515 return; 1516 } 1517 } 1518 #endif 1519 1520 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1521 #ifdef INET6 1522 if (isipv6) { 1523 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1524 nth->th_sum = in6_cksum_pseudo(ip6, 1525 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1526 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1527 NULL, NULL); 1528 } 1529 #endif /* INET6 */ 1530 #if defined(INET6) && defined(INET) 1531 else 1532 #endif 1533 #ifdef INET 1534 { 1535 m->m_pkthdr.csum_flags = CSUM_TCP; 1536 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1537 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1538 } 1539 #endif /* INET */ 1540 #ifdef TCPDEBUG 1541 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1542 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1543 #endif 1544 TCP_PROBE3(debug__output, tp, th, m); 1545 if (flags & TH_RST) 1546 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1547 1548 #ifdef INET6 1549 if (isipv6) { 1550 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1551 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1552 } 1553 #endif /* INET6 */ 1554 #if defined(INET) && defined(INET6) 1555 else 1556 #endif 1557 #ifdef INET 1558 { 1559 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1560 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1561 } 1562 #endif 1563 } 1564 1565 /* 1566 * Create a new TCP control block, making an 1567 * empty reassembly queue and hooking it to the argument 1568 * protocol control block. The `inp' parameter must have 1569 * come from the zone allocator set up in tcp_init(). 1570 */ 1571 struct tcpcb * 1572 tcp_newtcpcb(struct inpcb *inp) 1573 { 1574 struct tcpcb_mem *tm; 1575 struct tcpcb *tp; 1576 #ifdef INET6 1577 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1578 #endif /* INET6 */ 1579 1580 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1581 if (tm == NULL) 1582 return (NULL); 1583 tp = &tm->tcb; 1584 1585 /* Initialise cc_var struct for this tcpcb. */ 1586 tp->ccv = &tm->ccv; 1587 tp->ccv->type = IPPROTO_TCP; 1588 tp->ccv->ccvc.tcp = tp; 1589 rw_rlock(&tcp_function_lock); 1590 tp->t_fb = tcp_func_set_ptr; 1591 refcount_acquire(&tp->t_fb->tfb_refcnt); 1592 rw_runlock(&tcp_function_lock); 1593 /* 1594 * Use the current system default CC algorithm. 1595 */ 1596 CC_LIST_RLOCK(); 1597 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1598 CC_ALGO(tp) = CC_DEFAULT(); 1599 CC_LIST_RUNLOCK(); 1600 1601 if (CC_ALGO(tp)->cb_init != NULL) 1602 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1603 if (tp->t_fb->tfb_tcp_fb_fini) 1604 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1605 refcount_release(&tp->t_fb->tfb_refcnt); 1606 uma_zfree(V_tcpcb_zone, tm); 1607 return (NULL); 1608 } 1609 1610 #ifdef TCP_HHOOK 1611 tp->osd = &tm->osd; 1612 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1613 if (tp->t_fb->tfb_tcp_fb_fini) 1614 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1615 refcount_release(&tp->t_fb->tfb_refcnt); 1616 uma_zfree(V_tcpcb_zone, tm); 1617 return (NULL); 1618 } 1619 #endif 1620 1621 #ifdef VIMAGE 1622 tp->t_vnet = inp->inp_vnet; 1623 #endif 1624 tp->t_timers = &tm->tt; 1625 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1626 tp->t_maxseg = 1627 #ifdef INET6 1628 isipv6 ? V_tcp_v6mssdflt : 1629 #endif /* INET6 */ 1630 V_tcp_mssdflt; 1631 1632 /* Set up our timeouts. */ 1633 callout_init(&tp->t_timers->tt_rexmt, 1); 1634 callout_init(&tp->t_timers->tt_persist, 1); 1635 callout_init(&tp->t_timers->tt_keep, 1); 1636 callout_init(&tp->t_timers->tt_2msl, 1); 1637 callout_init(&tp->t_timers->tt_delack, 1); 1638 1639 if (V_tcp_do_rfc1323) 1640 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1641 if (V_tcp_do_sack) 1642 tp->t_flags |= TF_SACK_PERMIT; 1643 TAILQ_INIT(&tp->snd_holes); 1644 /* 1645 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1646 * is called. 1647 */ 1648 in_pcbref(inp); /* Reference for tcpcb */ 1649 tp->t_inpcb = inp; 1650 1651 /* 1652 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1653 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1654 * reasonable initial retransmit time. 1655 */ 1656 tp->t_srtt = TCPTV_SRTTBASE; 1657 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1658 tp->t_rttmin = tcp_rexmit_min; 1659 tp->t_rxtcur = TCPTV_RTOBASE; 1660 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1661 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1662 tp->t_rcvtime = ticks; 1663 /* 1664 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1665 * because the socket may be bound to an IPv6 wildcard address, 1666 * which may match an IPv4-mapped IPv6 address. 1667 */ 1668 inp->inp_ip_ttl = V_ip_defttl; 1669 inp->inp_ppcb = tp; 1670 #ifdef TCPPCAP 1671 /* 1672 * Init the TCP PCAP queues. 1673 */ 1674 tcp_pcap_tcpcb_init(tp); 1675 #endif 1676 #ifdef TCP_BLACKBOX 1677 /* Initialize the per-TCPCB log data. */ 1678 tcp_log_tcpcbinit(tp); 1679 #endif 1680 if (tp->t_fb->tfb_tcp_fb_init) { 1681 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1682 } 1683 return (tp); /* XXX */ 1684 } 1685 1686 /* 1687 * Switch the congestion control algorithm back to NewReno for any active 1688 * control blocks using an algorithm which is about to go away. 1689 * This ensures the CC framework can allow the unload to proceed without leaving 1690 * any dangling pointers which would trigger a panic. 1691 * Returning non-zero would inform the CC framework that something went wrong 1692 * and it would be unsafe to allow the unload to proceed. However, there is no 1693 * way for this to occur with this implementation so we always return zero. 1694 */ 1695 int 1696 tcp_ccalgounload(struct cc_algo *unload_algo) 1697 { 1698 struct cc_algo *tmpalgo; 1699 struct inpcb *inp; 1700 struct tcpcb *tp; 1701 VNET_ITERATOR_DECL(vnet_iter); 1702 1703 /* 1704 * Check all active control blocks across all network stacks and change 1705 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1706 * requires cleanup code to be run, call it. 1707 */ 1708 VNET_LIST_RLOCK(); 1709 VNET_FOREACH(vnet_iter) { 1710 CURVNET_SET(vnet_iter); 1711 INP_INFO_WLOCK(&V_tcbinfo); 1712 /* 1713 * New connections already part way through being initialised 1714 * with the CC algo we're removing will not race with this code 1715 * because the INP_INFO_WLOCK is held during initialisation. We 1716 * therefore don't enter the loop below until the connection 1717 * list has stabilised. 1718 */ 1719 LIST_FOREACH(inp, &V_tcb, inp_list) { 1720 INP_WLOCK(inp); 1721 /* Important to skip tcptw structs. */ 1722 if (!(inp->inp_flags & INP_TIMEWAIT) && 1723 (tp = intotcpcb(inp)) != NULL) { 1724 /* 1725 * By holding INP_WLOCK here, we are assured 1726 * that the connection is not currently 1727 * executing inside the CC module's functions 1728 * i.e. it is safe to make the switch back to 1729 * NewReno. 1730 */ 1731 if (CC_ALGO(tp) == unload_algo) { 1732 tmpalgo = CC_ALGO(tp); 1733 /* NewReno does not require any init. */ 1734 CC_ALGO(tp) = &newreno_cc_algo; 1735 if (tmpalgo->cb_destroy != NULL) 1736 tmpalgo->cb_destroy(tp->ccv); 1737 } 1738 } 1739 INP_WUNLOCK(inp); 1740 } 1741 INP_INFO_WUNLOCK(&V_tcbinfo); 1742 CURVNET_RESTORE(); 1743 } 1744 VNET_LIST_RUNLOCK(); 1745 1746 return (0); 1747 } 1748 1749 /* 1750 * Drop a TCP connection, reporting 1751 * the specified error. If connection is synchronized, 1752 * then send a RST to peer. 1753 */ 1754 struct tcpcb * 1755 tcp_drop(struct tcpcb *tp, int errno) 1756 { 1757 struct socket *so = tp->t_inpcb->inp_socket; 1758 1759 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1760 INP_WLOCK_ASSERT(tp->t_inpcb); 1761 1762 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1763 tcp_state_change(tp, TCPS_CLOSED); 1764 (void) tp->t_fb->tfb_tcp_output(tp); 1765 TCPSTAT_INC(tcps_drops); 1766 } else 1767 TCPSTAT_INC(tcps_conndrops); 1768 if (errno == ETIMEDOUT && tp->t_softerror) 1769 errno = tp->t_softerror; 1770 so->so_error = errno; 1771 return (tcp_close(tp)); 1772 } 1773 1774 void 1775 tcp_discardcb(struct tcpcb *tp) 1776 { 1777 struct inpcb *inp = tp->t_inpcb; 1778 struct socket *so = inp->inp_socket; 1779 #ifdef INET6 1780 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1781 #endif /* INET6 */ 1782 int released __unused; 1783 1784 INP_WLOCK_ASSERT(inp); 1785 1786 /* 1787 * Make sure that all of our timers are stopped before we delete the 1788 * PCB. 1789 * 1790 * If stopping a timer fails, we schedule a discard function in same 1791 * callout, and the last discard function called will take care of 1792 * deleting the tcpcb. 1793 */ 1794 tp->t_timers->tt_draincnt = 0; 1795 tcp_timer_stop(tp, TT_REXMT); 1796 tcp_timer_stop(tp, TT_PERSIST); 1797 tcp_timer_stop(tp, TT_KEEP); 1798 tcp_timer_stop(tp, TT_2MSL); 1799 tcp_timer_stop(tp, TT_DELACK); 1800 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1801 /* 1802 * Call the stop-all function of the methods, 1803 * this function should call the tcp_timer_stop() 1804 * method with each of the function specific timeouts. 1805 * That stop will be called via the tfb_tcp_timer_stop() 1806 * which should use the async drain function of the 1807 * callout system (see tcp_var.h). 1808 */ 1809 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1810 } 1811 1812 /* 1813 * If we got enough samples through the srtt filter, 1814 * save the rtt and rttvar in the routing entry. 1815 * 'Enough' is arbitrarily defined as 4 rtt samples. 1816 * 4 samples is enough for the srtt filter to converge 1817 * to within enough % of the correct value; fewer samples 1818 * and we could save a bogus rtt. The danger is not high 1819 * as tcp quickly recovers from everything. 1820 * XXX: Works very well but needs some more statistics! 1821 */ 1822 if (tp->t_rttupdated >= 4) { 1823 struct hc_metrics_lite metrics; 1824 uint32_t ssthresh; 1825 1826 bzero(&metrics, sizeof(metrics)); 1827 /* 1828 * Update the ssthresh always when the conditions below 1829 * are satisfied. This gives us better new start value 1830 * for the congestion avoidance for new connections. 1831 * ssthresh is only set if packet loss occurred on a session. 1832 * 1833 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1834 * being torn down. Ideally this code would not use 'so'. 1835 */ 1836 ssthresh = tp->snd_ssthresh; 1837 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1838 /* 1839 * convert the limit from user data bytes to 1840 * packets then to packet data bytes. 1841 */ 1842 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1843 if (ssthresh < 2) 1844 ssthresh = 2; 1845 ssthresh *= (tp->t_maxseg + 1846 #ifdef INET6 1847 (isipv6 ? sizeof (struct ip6_hdr) + 1848 sizeof (struct tcphdr) : 1849 #endif 1850 sizeof (struct tcpiphdr) 1851 #ifdef INET6 1852 ) 1853 #endif 1854 ); 1855 } else 1856 ssthresh = 0; 1857 metrics.rmx_ssthresh = ssthresh; 1858 1859 metrics.rmx_rtt = tp->t_srtt; 1860 metrics.rmx_rttvar = tp->t_rttvar; 1861 metrics.rmx_cwnd = tp->snd_cwnd; 1862 metrics.rmx_sendpipe = 0; 1863 metrics.rmx_recvpipe = 0; 1864 1865 tcp_hc_update(&inp->inp_inc, &metrics); 1866 } 1867 1868 /* free the reassembly queue, if any */ 1869 tcp_reass_flush(tp); 1870 1871 #ifdef TCP_OFFLOAD 1872 /* Disconnect offload device, if any. */ 1873 if (tp->t_flags & TF_TOE) 1874 tcp_offload_detach(tp); 1875 #endif 1876 1877 tcp_free_sackholes(tp); 1878 1879 #ifdef TCPPCAP 1880 /* Free the TCP PCAP queues. */ 1881 tcp_pcap_drain(&(tp->t_inpkts)); 1882 tcp_pcap_drain(&(tp->t_outpkts)); 1883 #endif 1884 1885 /* Allow the CC algorithm to clean up after itself. */ 1886 if (CC_ALGO(tp)->cb_destroy != NULL) 1887 CC_ALGO(tp)->cb_destroy(tp->ccv); 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 1918 tp = (struct tcpcb *)ptp; 1919 CURVNET_SET(tp->t_vnet); 1920 INP_INFO_RLOCK(&V_tcbinfo); 1921 inp = tp->t_inpcb; 1922 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1923 __func__, tp)); 1924 INP_WLOCK(inp); 1925 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1926 ("%s: tcpcb has to be stopped here", __func__)); 1927 tp->t_timers->tt_draincnt--; 1928 if (tp->t_timers->tt_draincnt == 0) { 1929 /* We own the last reference on this tcpcb, let's free it. */ 1930 #ifdef TCP_BLACKBOX 1931 tcp_log_tcpcbfini(tp); 1932 #endif 1933 TCPSTATES_DEC(tp->t_state); 1934 if (tp->t_fb->tfb_tcp_fb_fini) 1935 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1936 refcount_release(&tp->t_fb->tfb_refcnt); 1937 tp->t_inpcb = NULL; 1938 uma_zfree(V_tcpcb_zone, tp); 1939 if (in_pcbrele_wlocked(inp)) { 1940 INP_INFO_RUNLOCK(&V_tcbinfo); 1941 CURVNET_RESTORE(); 1942 return; 1943 } 1944 } 1945 INP_WUNLOCK(inp); 1946 INP_INFO_RUNLOCK(&V_tcbinfo); 1947 CURVNET_RESTORE(); 1948 } 1949 1950 /* 1951 * Attempt to close a TCP control block, marking it as dropped, and freeing 1952 * the socket if we hold the only reference. 1953 */ 1954 struct tcpcb * 1955 tcp_close(struct tcpcb *tp) 1956 { 1957 struct inpcb *inp = tp->t_inpcb; 1958 struct socket *so; 1959 1960 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1961 INP_WLOCK_ASSERT(inp); 1962 1963 #ifdef TCP_OFFLOAD 1964 if (tp->t_state == TCPS_LISTEN) 1965 tcp_offload_listen_stop(tp); 1966 #endif 1967 /* 1968 * This releases the TFO pending counter resource for TFO listen 1969 * sockets as well as passively-created TFO sockets that transition 1970 * from SYN_RECEIVED to CLOSED. 1971 */ 1972 if (tp->t_tfo_pending) { 1973 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1974 tp->t_tfo_pending = NULL; 1975 } 1976 in_pcbdrop(inp); 1977 TCPSTAT_INC(tcps_closed); 1978 if (tp->t_state != TCPS_CLOSED) 1979 tcp_state_change(tp, TCPS_CLOSED); 1980 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1981 so = inp->inp_socket; 1982 soisdisconnected(so); 1983 if (inp->inp_flags & INP_SOCKREF) { 1984 KASSERT(so->so_state & SS_PROTOREF, 1985 ("tcp_close: !SS_PROTOREF")); 1986 inp->inp_flags &= ~INP_SOCKREF; 1987 INP_WUNLOCK(inp); 1988 SOCK_LOCK(so); 1989 so->so_state &= ~SS_PROTOREF; 1990 sofree(so); 1991 return (NULL); 1992 } 1993 return (tp); 1994 } 1995 1996 void 1997 tcp_drain(void) 1998 { 1999 VNET_ITERATOR_DECL(vnet_iter); 2000 2001 if (!do_tcpdrain) 2002 return; 2003 2004 VNET_LIST_RLOCK_NOSLEEP(); 2005 VNET_FOREACH(vnet_iter) { 2006 CURVNET_SET(vnet_iter); 2007 struct inpcb *inpb; 2008 struct tcpcb *tcpb; 2009 2010 /* 2011 * Walk the tcpbs, if existing, and flush the reassembly queue, 2012 * if there is one... 2013 * XXX: The "Net/3" implementation doesn't imply that the TCP 2014 * reassembly queue should be flushed, but in a situation 2015 * where we're really low on mbufs, this is potentially 2016 * useful. 2017 */ 2018 INP_INFO_WLOCK(&V_tcbinfo); 2019 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2020 if (inpb->inp_flags & INP_TIMEWAIT) 2021 continue; 2022 INP_WLOCK(inpb); 2023 if ((tcpb = intotcpcb(inpb)) != NULL) { 2024 tcp_reass_flush(tcpb); 2025 tcp_clean_sackreport(tcpb); 2026 #ifdef TCP_BLACKBOX 2027 tcp_log_drain(tcpb); 2028 #endif 2029 #ifdef TCPPCAP 2030 if (tcp_pcap_aggressive_free) { 2031 /* Free the TCP PCAP queues. */ 2032 tcp_pcap_drain(&(tcpb->t_inpkts)); 2033 tcp_pcap_drain(&(tcpb->t_outpkts)); 2034 } 2035 #endif 2036 } 2037 INP_WUNLOCK(inpb); 2038 } 2039 INP_INFO_WUNLOCK(&V_tcbinfo); 2040 CURVNET_RESTORE(); 2041 } 2042 VNET_LIST_RUNLOCK_NOSLEEP(); 2043 } 2044 2045 /* 2046 * Notify a tcp user of an asynchronous error; 2047 * store error as soft error, but wake up user 2048 * (for now, won't do anything until can select for soft error). 2049 * 2050 * Do not wake up user since there currently is no mechanism for 2051 * reporting soft errors (yet - a kqueue filter may be added). 2052 */ 2053 static struct inpcb * 2054 tcp_notify(struct inpcb *inp, int error) 2055 { 2056 struct tcpcb *tp; 2057 2058 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2059 INP_WLOCK_ASSERT(inp); 2060 2061 if ((inp->inp_flags & INP_TIMEWAIT) || 2062 (inp->inp_flags & INP_DROPPED)) 2063 return (inp); 2064 2065 tp = intotcpcb(inp); 2066 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2067 2068 /* 2069 * Ignore some errors if we are hooked up. 2070 * If connection hasn't completed, has retransmitted several times, 2071 * and receives a second error, give up now. This is better 2072 * than waiting a long time to establish a connection that 2073 * can never complete. 2074 */ 2075 if (tp->t_state == TCPS_ESTABLISHED && 2076 (error == EHOSTUNREACH || error == ENETUNREACH || 2077 error == EHOSTDOWN)) { 2078 if (inp->inp_route.ro_rt) { 2079 RTFREE(inp->inp_route.ro_rt); 2080 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2081 } 2082 return (inp); 2083 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2084 tp->t_softerror) { 2085 tp = tcp_drop(tp, error); 2086 if (tp != NULL) 2087 return (inp); 2088 else 2089 return (NULL); 2090 } else { 2091 tp->t_softerror = error; 2092 return (inp); 2093 } 2094 #if 0 2095 wakeup( &so->so_timeo); 2096 sorwakeup(so); 2097 sowwakeup(so); 2098 #endif 2099 } 2100 2101 static int 2102 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2103 { 2104 int error, i, m, n, pcb_count; 2105 struct inpcb *inp, **inp_list; 2106 inp_gen_t gencnt; 2107 struct xinpgen xig; 2108 2109 /* 2110 * The process of preparing the TCB list is too time-consuming and 2111 * resource-intensive to repeat twice on every request. 2112 */ 2113 if (req->oldptr == NULL) { 2114 n = V_tcbinfo.ipi_count + 2115 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2116 n += imax(n / 8, 10); 2117 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2118 return (0); 2119 } 2120 2121 if (req->newptr != NULL) 2122 return (EPERM); 2123 2124 /* 2125 * OK, now we're committed to doing something. 2126 */ 2127 INP_LIST_RLOCK(&V_tcbinfo); 2128 gencnt = V_tcbinfo.ipi_gencnt; 2129 n = V_tcbinfo.ipi_count; 2130 INP_LIST_RUNLOCK(&V_tcbinfo); 2131 2132 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2133 2134 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2135 + (n + m) * sizeof(struct xtcpcb)); 2136 if (error != 0) 2137 return (error); 2138 2139 xig.xig_len = sizeof xig; 2140 xig.xig_count = n + m; 2141 xig.xig_gen = gencnt; 2142 xig.xig_sogen = so_gencnt; 2143 error = SYSCTL_OUT(req, &xig, sizeof xig); 2144 if (error) 2145 return (error); 2146 2147 error = syncache_pcblist(req, m, &pcb_count); 2148 if (error) 2149 return (error); 2150 2151 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2152 2153 INP_INFO_WLOCK(&V_tcbinfo); 2154 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2155 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 2156 INP_WLOCK(inp); 2157 if (inp->inp_gencnt <= gencnt) { 2158 /* 2159 * XXX: This use of cr_cansee(), introduced with 2160 * TCP state changes, is not quite right, but for 2161 * now, better than nothing. 2162 */ 2163 if (inp->inp_flags & INP_TIMEWAIT) { 2164 if (intotw(inp) != NULL) 2165 error = cr_cansee(req->td->td_ucred, 2166 intotw(inp)->tw_cred); 2167 else 2168 error = EINVAL; /* Skip this inp. */ 2169 } else 2170 error = cr_canseeinpcb(req->td->td_ucred, inp); 2171 if (error == 0) { 2172 in_pcbref(inp); 2173 inp_list[i++] = inp; 2174 } 2175 } 2176 INP_WUNLOCK(inp); 2177 } 2178 INP_INFO_WUNLOCK(&V_tcbinfo); 2179 n = i; 2180 2181 error = 0; 2182 for (i = 0; i < n; i++) { 2183 inp = inp_list[i]; 2184 INP_RLOCK(inp); 2185 if (inp->inp_gencnt <= gencnt) { 2186 struct xtcpcb xt; 2187 2188 tcp_inptoxtp(inp, &xt); 2189 INP_RUNLOCK(inp); 2190 error = SYSCTL_OUT(req, &xt, sizeof xt); 2191 } else 2192 INP_RUNLOCK(inp); 2193 } 2194 INP_INFO_RLOCK(&V_tcbinfo); 2195 for (i = 0; i < n; i++) { 2196 inp = inp_list[i]; 2197 INP_RLOCK(inp); 2198 if (!in_pcbrele_rlocked(inp)) 2199 INP_RUNLOCK(inp); 2200 } 2201 INP_INFO_RUNLOCK(&V_tcbinfo); 2202 2203 if (!error) { 2204 /* 2205 * Give the user an updated idea of our state. 2206 * If the generation differs from what we told 2207 * her before, she knows that something happened 2208 * while we were processing this request, and it 2209 * might be necessary to retry. 2210 */ 2211 INP_LIST_RLOCK(&V_tcbinfo); 2212 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2213 xig.xig_sogen = so_gencnt; 2214 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2215 INP_LIST_RUNLOCK(&V_tcbinfo); 2216 error = SYSCTL_OUT(req, &xig, sizeof xig); 2217 } 2218 free(inp_list, M_TEMP); 2219 return (error); 2220 } 2221 2222 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2223 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2224 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2225 2226 #ifdef INET 2227 static int 2228 tcp_getcred(SYSCTL_HANDLER_ARGS) 2229 { 2230 struct xucred xuc; 2231 struct sockaddr_in addrs[2]; 2232 struct inpcb *inp; 2233 int error; 2234 2235 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2236 if (error) 2237 return (error); 2238 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2239 if (error) 2240 return (error); 2241 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2242 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2243 if (inp != NULL) { 2244 if (inp->inp_socket == NULL) 2245 error = ENOENT; 2246 if (error == 0) 2247 error = cr_canseeinpcb(req->td->td_ucred, inp); 2248 if (error == 0) 2249 cru2x(inp->inp_cred, &xuc); 2250 INP_RUNLOCK(inp); 2251 } else 2252 error = ENOENT; 2253 if (error == 0) 2254 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2255 return (error); 2256 } 2257 2258 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2259 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2260 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2261 #endif /* INET */ 2262 2263 #ifdef INET6 2264 static int 2265 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2266 { 2267 struct xucred xuc; 2268 struct sockaddr_in6 addrs[2]; 2269 struct inpcb *inp; 2270 int error; 2271 #ifdef INET 2272 int mapped = 0; 2273 #endif 2274 2275 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2276 if (error) 2277 return (error); 2278 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2279 if (error) 2280 return (error); 2281 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2282 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2283 return (error); 2284 } 2285 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2286 #ifdef INET 2287 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2288 mapped = 1; 2289 else 2290 #endif 2291 return (EINVAL); 2292 } 2293 2294 #ifdef INET 2295 if (mapped == 1) 2296 inp = in_pcblookup(&V_tcbinfo, 2297 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2298 addrs[1].sin6_port, 2299 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2300 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2301 else 2302 #endif 2303 inp = in6_pcblookup(&V_tcbinfo, 2304 &addrs[1].sin6_addr, addrs[1].sin6_port, 2305 &addrs[0].sin6_addr, addrs[0].sin6_port, 2306 INPLOOKUP_RLOCKPCB, NULL); 2307 if (inp != NULL) { 2308 if (inp->inp_socket == NULL) 2309 error = ENOENT; 2310 if (error == 0) 2311 error = cr_canseeinpcb(req->td->td_ucred, inp); 2312 if (error == 0) 2313 cru2x(inp->inp_cred, &xuc); 2314 INP_RUNLOCK(inp); 2315 } else 2316 error = ENOENT; 2317 if (error == 0) 2318 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2319 return (error); 2320 } 2321 2322 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2323 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2324 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2325 #endif /* INET6 */ 2326 2327 2328 #ifdef INET 2329 void 2330 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2331 { 2332 struct ip *ip = vip; 2333 struct tcphdr *th; 2334 struct in_addr faddr; 2335 struct inpcb *inp; 2336 struct tcpcb *tp; 2337 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2338 struct icmp *icp; 2339 struct in_conninfo inc; 2340 tcp_seq icmp_tcp_seq; 2341 int mtu; 2342 2343 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2344 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2345 return; 2346 2347 if (cmd == PRC_MSGSIZE) 2348 notify = tcp_mtudisc_notify; 2349 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2350 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2351 cmd == PRC_TIMXCEED_INTRANS) && ip) 2352 notify = tcp_drop_syn_sent; 2353 2354 /* 2355 * Hostdead is ugly because it goes linearly through all PCBs. 2356 * XXX: We never get this from ICMP, otherwise it makes an 2357 * excellent DoS attack on machines with many connections. 2358 */ 2359 else if (cmd == PRC_HOSTDEAD) 2360 ip = NULL; 2361 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2362 return; 2363 2364 if (ip == NULL) { 2365 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2366 return; 2367 } 2368 2369 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2370 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2371 INP_INFO_RLOCK(&V_tcbinfo); 2372 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2373 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2374 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2375 /* signal EHOSTDOWN, as it flushes the cached route */ 2376 inp = (*notify)(inp, EHOSTDOWN); 2377 goto out; 2378 } 2379 icmp_tcp_seq = th->th_seq; 2380 if (inp != NULL) { 2381 if (!(inp->inp_flags & INP_TIMEWAIT) && 2382 !(inp->inp_flags & INP_DROPPED) && 2383 !(inp->inp_socket == NULL)) { 2384 tp = intotcpcb(inp); 2385 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2386 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2387 if (cmd == PRC_MSGSIZE) { 2388 /* 2389 * MTU discovery: 2390 * If we got a needfrag set the MTU 2391 * in the route to the suggested new 2392 * value (if given) and then notify. 2393 */ 2394 mtu = ntohs(icp->icmp_nextmtu); 2395 /* 2396 * If no alternative MTU was 2397 * proposed, try the next smaller 2398 * one. 2399 */ 2400 if (!mtu) 2401 mtu = ip_next_mtu( 2402 ntohs(ip->ip_len), 1); 2403 if (mtu < V_tcp_minmss + 2404 sizeof(struct tcpiphdr)) 2405 mtu = V_tcp_minmss + 2406 sizeof(struct tcpiphdr); 2407 /* 2408 * Only process the offered MTU if it 2409 * is smaller than the current one. 2410 */ 2411 if (mtu < tp->t_maxseg + 2412 sizeof(struct tcpiphdr)) { 2413 bzero(&inc, sizeof(inc)); 2414 inc.inc_faddr = faddr; 2415 inc.inc_fibnum = 2416 inp->inp_inc.inc_fibnum; 2417 tcp_hc_updatemtu(&inc, mtu); 2418 tcp_mtudisc(inp, mtu); 2419 } 2420 } else 2421 inp = (*notify)(inp, 2422 inetctlerrmap[cmd]); 2423 } 2424 } 2425 } else { 2426 bzero(&inc, sizeof(inc)); 2427 inc.inc_fport = th->th_dport; 2428 inc.inc_lport = th->th_sport; 2429 inc.inc_faddr = faddr; 2430 inc.inc_laddr = ip->ip_src; 2431 syncache_unreach(&inc, icmp_tcp_seq); 2432 } 2433 out: 2434 if (inp != NULL) 2435 INP_WUNLOCK(inp); 2436 INP_INFO_RUNLOCK(&V_tcbinfo); 2437 } 2438 #endif /* INET */ 2439 2440 #ifdef INET6 2441 void 2442 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2443 { 2444 struct in6_addr *dst; 2445 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2446 struct ip6_hdr *ip6; 2447 struct mbuf *m; 2448 struct inpcb *inp; 2449 struct tcpcb *tp; 2450 struct icmp6_hdr *icmp6; 2451 struct ip6ctlparam *ip6cp = NULL; 2452 const struct sockaddr_in6 *sa6_src = NULL; 2453 struct in_conninfo inc; 2454 struct tcp_ports { 2455 uint16_t th_sport; 2456 uint16_t th_dport; 2457 } t_ports; 2458 tcp_seq icmp_tcp_seq; 2459 unsigned int mtu; 2460 unsigned int off; 2461 2462 if (sa->sa_family != AF_INET6 || 2463 sa->sa_len != sizeof(struct sockaddr_in6)) 2464 return; 2465 2466 /* if the parameter is from icmp6, decode it. */ 2467 if (d != NULL) { 2468 ip6cp = (struct ip6ctlparam *)d; 2469 icmp6 = ip6cp->ip6c_icmp6; 2470 m = ip6cp->ip6c_m; 2471 ip6 = ip6cp->ip6c_ip6; 2472 off = ip6cp->ip6c_off; 2473 sa6_src = ip6cp->ip6c_src; 2474 dst = ip6cp->ip6c_finaldst; 2475 } else { 2476 m = NULL; 2477 ip6 = NULL; 2478 off = 0; /* fool gcc */ 2479 sa6_src = &sa6_any; 2480 dst = NULL; 2481 } 2482 2483 if (cmd == PRC_MSGSIZE) 2484 notify = tcp_mtudisc_notify; 2485 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2486 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2487 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2488 notify = tcp_drop_syn_sent; 2489 2490 /* 2491 * Hostdead is ugly because it goes linearly through all PCBs. 2492 * XXX: We never get this from ICMP, otherwise it makes an 2493 * excellent DoS attack on machines with many connections. 2494 */ 2495 else if (cmd == PRC_HOSTDEAD) 2496 ip6 = NULL; 2497 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2498 return; 2499 2500 if (ip6 == NULL) { 2501 in6_pcbnotify(&V_tcbinfo, sa, 0, 2502 (const struct sockaddr *)sa6_src, 2503 0, cmd, NULL, notify); 2504 return; 2505 } 2506 2507 /* Check if we can safely get the ports from the tcp hdr */ 2508 if (m == NULL || 2509 (m->m_pkthdr.len < 2510 (int32_t) (off + sizeof(struct tcp_ports)))) { 2511 return; 2512 } 2513 bzero(&t_ports, sizeof(struct tcp_ports)); 2514 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2515 INP_INFO_RLOCK(&V_tcbinfo); 2516 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2517 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2518 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2519 /* signal EHOSTDOWN, as it flushes the cached route */ 2520 inp = (*notify)(inp, EHOSTDOWN); 2521 goto out; 2522 } 2523 off += sizeof(struct tcp_ports); 2524 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2525 goto out; 2526 } 2527 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2528 if (inp != NULL) { 2529 if (!(inp->inp_flags & INP_TIMEWAIT) && 2530 !(inp->inp_flags & INP_DROPPED) && 2531 !(inp->inp_socket == NULL)) { 2532 tp = intotcpcb(inp); 2533 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2534 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2535 if (cmd == PRC_MSGSIZE) { 2536 /* 2537 * MTU discovery: 2538 * If we got a needfrag set the MTU 2539 * in the route to the suggested new 2540 * value (if given) and then notify. 2541 */ 2542 mtu = ntohl(icmp6->icmp6_mtu); 2543 /* 2544 * If no alternative MTU was 2545 * proposed, or the proposed 2546 * MTU was too small, set to 2547 * the min. 2548 */ 2549 if (mtu < IPV6_MMTU) 2550 mtu = IPV6_MMTU - 8; 2551 bzero(&inc, sizeof(inc)); 2552 inc.inc_fibnum = M_GETFIB(m); 2553 inc.inc_flags |= INC_ISIPV6; 2554 inc.inc6_faddr = *dst; 2555 if (in6_setscope(&inc.inc6_faddr, 2556 m->m_pkthdr.rcvif, NULL)) 2557 goto out; 2558 /* 2559 * Only process the offered MTU if it 2560 * is smaller than the current one. 2561 */ 2562 if (mtu < tp->t_maxseg + 2563 sizeof (struct tcphdr) + 2564 sizeof (struct ip6_hdr)) { 2565 tcp_hc_updatemtu(&inc, mtu); 2566 tcp_mtudisc(inp, mtu); 2567 ICMP6STAT_INC(icp6s_pmtuchg); 2568 } 2569 } else 2570 inp = (*notify)(inp, 2571 inet6ctlerrmap[cmd]); 2572 } 2573 } 2574 } else { 2575 bzero(&inc, sizeof(inc)); 2576 inc.inc_fibnum = M_GETFIB(m); 2577 inc.inc_flags |= INC_ISIPV6; 2578 inc.inc_fport = t_ports.th_dport; 2579 inc.inc_lport = t_ports.th_sport; 2580 inc.inc6_faddr = *dst; 2581 inc.inc6_laddr = ip6->ip6_src; 2582 syncache_unreach(&inc, icmp_tcp_seq); 2583 } 2584 out: 2585 if (inp != NULL) 2586 INP_WUNLOCK(inp); 2587 INP_INFO_RUNLOCK(&V_tcbinfo); 2588 } 2589 #endif /* INET6 */ 2590 2591 2592 /* 2593 * Following is where TCP initial sequence number generation occurs. 2594 * 2595 * There are two places where we must use initial sequence numbers: 2596 * 1. In SYN-ACK packets. 2597 * 2. In SYN packets. 2598 * 2599 * All ISNs for SYN-ACK packets are generated by the syncache. See 2600 * tcp_syncache.c for details. 2601 * 2602 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2603 * depends on this property. In addition, these ISNs should be 2604 * unguessable so as to prevent connection hijacking. To satisfy 2605 * the requirements of this situation, the algorithm outlined in 2606 * RFC 1948 is used, with only small modifications. 2607 * 2608 * Implementation details: 2609 * 2610 * Time is based off the system timer, and is corrected so that it 2611 * increases by one megabyte per second. This allows for proper 2612 * recycling on high speed LANs while still leaving over an hour 2613 * before rollover. 2614 * 2615 * As reading the *exact* system time is too expensive to be done 2616 * whenever setting up a TCP connection, we increment the time 2617 * offset in two ways. First, a small random positive increment 2618 * is added to isn_offset for each connection that is set up. 2619 * Second, the function tcp_isn_tick fires once per clock tick 2620 * and increments isn_offset as necessary so that sequence numbers 2621 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2622 * random positive increments serve only to ensure that the same 2623 * exact sequence number is never sent out twice (as could otherwise 2624 * happen when a port is recycled in less than the system tick 2625 * interval.) 2626 * 2627 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2628 * between seeding of isn_secret. This is normally set to zero, 2629 * as reseeding should not be necessary. 2630 * 2631 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2632 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2633 * general, this means holding an exclusive (write) lock. 2634 */ 2635 2636 #define ISN_BYTES_PER_SECOND 1048576 2637 #define ISN_STATIC_INCREMENT 4096 2638 #define ISN_RANDOM_INCREMENT (4096 - 1) 2639 2640 static VNET_DEFINE(u_char, isn_secret[32]); 2641 static VNET_DEFINE(int, isn_last); 2642 static VNET_DEFINE(int, isn_last_reseed); 2643 static VNET_DEFINE(u_int32_t, isn_offset); 2644 static VNET_DEFINE(u_int32_t, isn_offset_old); 2645 2646 #define V_isn_secret VNET(isn_secret) 2647 #define V_isn_last VNET(isn_last) 2648 #define V_isn_last_reseed VNET(isn_last_reseed) 2649 #define V_isn_offset VNET(isn_offset) 2650 #define V_isn_offset_old VNET(isn_offset_old) 2651 2652 tcp_seq 2653 tcp_new_isn(struct tcpcb *tp) 2654 { 2655 MD5_CTX isn_ctx; 2656 u_int32_t md5_buffer[4]; 2657 tcp_seq new_isn; 2658 u_int32_t projected_offset; 2659 2660 INP_WLOCK_ASSERT(tp->t_inpcb); 2661 2662 ISN_LOCK(); 2663 /* Seed if this is the first use, reseed if requested. */ 2664 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2665 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2666 < (u_int)ticks))) { 2667 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2668 V_isn_last_reseed = ticks; 2669 } 2670 2671 /* Compute the md5 hash and return the ISN. */ 2672 MD5Init(&isn_ctx); 2673 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2674 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2675 #ifdef INET6 2676 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2677 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2678 sizeof(struct in6_addr)); 2679 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2680 sizeof(struct in6_addr)); 2681 } else 2682 #endif 2683 { 2684 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2685 sizeof(struct in_addr)); 2686 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2687 sizeof(struct in_addr)); 2688 } 2689 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2690 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2691 new_isn = (tcp_seq) md5_buffer[0]; 2692 V_isn_offset += ISN_STATIC_INCREMENT + 2693 (arc4random() & ISN_RANDOM_INCREMENT); 2694 if (ticks != V_isn_last) { 2695 projected_offset = V_isn_offset_old + 2696 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2697 if (SEQ_GT(projected_offset, V_isn_offset)) 2698 V_isn_offset = projected_offset; 2699 V_isn_offset_old = V_isn_offset; 2700 V_isn_last = ticks; 2701 } 2702 new_isn += V_isn_offset; 2703 ISN_UNLOCK(); 2704 return (new_isn); 2705 } 2706 2707 /* 2708 * When a specific ICMP unreachable message is received and the 2709 * connection state is SYN-SENT, drop the connection. This behavior 2710 * is controlled by the icmp_may_rst sysctl. 2711 */ 2712 struct inpcb * 2713 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2714 { 2715 struct tcpcb *tp; 2716 2717 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2718 INP_WLOCK_ASSERT(inp); 2719 2720 if ((inp->inp_flags & INP_TIMEWAIT) || 2721 (inp->inp_flags & INP_DROPPED)) 2722 return (inp); 2723 2724 tp = intotcpcb(inp); 2725 if (tp->t_state != TCPS_SYN_SENT) 2726 return (inp); 2727 2728 if (IS_FASTOPEN(tp->t_flags)) 2729 tcp_fastopen_disable_path(tp); 2730 2731 tp = tcp_drop(tp, errno); 2732 if (tp != NULL) 2733 return (inp); 2734 else 2735 return (NULL); 2736 } 2737 2738 /* 2739 * When `need fragmentation' ICMP is received, update our idea of the MSS 2740 * based on the new value. Also nudge TCP to send something, since we 2741 * know the packet we just sent was dropped. 2742 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2743 */ 2744 static struct inpcb * 2745 tcp_mtudisc_notify(struct inpcb *inp, int error) 2746 { 2747 2748 tcp_mtudisc(inp, -1); 2749 return (inp); 2750 } 2751 2752 static void 2753 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2754 { 2755 struct tcpcb *tp; 2756 struct socket *so; 2757 2758 INP_WLOCK_ASSERT(inp); 2759 if ((inp->inp_flags & INP_TIMEWAIT) || 2760 (inp->inp_flags & INP_DROPPED)) 2761 return; 2762 2763 tp = intotcpcb(inp); 2764 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2765 2766 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2767 2768 so = inp->inp_socket; 2769 SOCKBUF_LOCK(&so->so_snd); 2770 /* If the mss is larger than the socket buffer, decrease the mss. */ 2771 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2772 tp->t_maxseg = so->so_snd.sb_hiwat; 2773 SOCKBUF_UNLOCK(&so->so_snd); 2774 2775 TCPSTAT_INC(tcps_mturesent); 2776 tp->t_rtttime = 0; 2777 tp->snd_nxt = tp->snd_una; 2778 tcp_free_sackholes(tp); 2779 tp->snd_recover = tp->snd_max; 2780 if (tp->t_flags & TF_SACK_PERMIT) 2781 EXIT_FASTRECOVERY(tp->t_flags); 2782 tp->t_fb->tfb_tcp_output(tp); 2783 } 2784 2785 #ifdef INET 2786 /* 2787 * Look-up the routing entry to the peer of this inpcb. If no route 2788 * is found and it cannot be allocated, then return 0. This routine 2789 * is called by TCP routines that access the rmx structure and by 2790 * tcp_mss_update to get the peer/interface MTU. 2791 */ 2792 uint32_t 2793 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2794 { 2795 struct nhop4_extended nh4; 2796 struct ifnet *ifp; 2797 uint32_t maxmtu = 0; 2798 2799 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2800 2801 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2802 2803 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2804 NHR_REF, 0, &nh4) != 0) 2805 return (0); 2806 2807 ifp = nh4.nh_ifp; 2808 maxmtu = nh4.nh_mtu; 2809 2810 /* Report additional interface capabilities. */ 2811 if (cap != NULL) { 2812 if (ifp->if_capenable & IFCAP_TSO4 && 2813 ifp->if_hwassist & CSUM_TSO) { 2814 cap->ifcap |= CSUM_TSO; 2815 cap->tsomax = ifp->if_hw_tsomax; 2816 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2817 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2818 } 2819 } 2820 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2821 } 2822 return (maxmtu); 2823 } 2824 #endif /* INET */ 2825 2826 #ifdef INET6 2827 uint32_t 2828 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2829 { 2830 struct nhop6_extended nh6; 2831 struct in6_addr dst6; 2832 uint32_t scopeid; 2833 struct ifnet *ifp; 2834 uint32_t maxmtu = 0; 2835 2836 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2837 2838 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2839 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2840 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2841 0, &nh6) != 0) 2842 return (0); 2843 2844 ifp = nh6.nh_ifp; 2845 maxmtu = nh6.nh_mtu; 2846 2847 /* Report additional interface capabilities. */ 2848 if (cap != NULL) { 2849 if (ifp->if_capenable & IFCAP_TSO6 && 2850 ifp->if_hwassist & CSUM_TSO) { 2851 cap->ifcap |= CSUM_TSO; 2852 cap->tsomax = ifp->if_hw_tsomax; 2853 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2854 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2855 } 2856 } 2857 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2858 } 2859 2860 return (maxmtu); 2861 } 2862 #endif /* INET6 */ 2863 2864 /* 2865 * Calculate effective SMSS per RFC5681 definition for a given TCP 2866 * connection at its current state, taking into account SACK and etc. 2867 */ 2868 u_int 2869 tcp_maxseg(const struct tcpcb *tp) 2870 { 2871 u_int optlen; 2872 2873 if (tp->t_flags & TF_NOOPT) 2874 return (tp->t_maxseg); 2875 2876 /* 2877 * Here we have a simplified code from tcp_addoptions(), 2878 * without a proper loop, and having most of paddings hardcoded. 2879 * We might make mistakes with padding here in some edge cases, 2880 * but this is harmless, since result of tcp_maxseg() is used 2881 * only in cwnd and ssthresh estimations. 2882 */ 2883 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2884 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2885 if (tp->t_flags & TF_RCVD_TSTMP) 2886 optlen = TCPOLEN_TSTAMP_APPA; 2887 else 2888 optlen = 0; 2889 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2890 if (tp->t_flags & TF_SIGNATURE) 2891 optlen += PAD(TCPOLEN_SIGNATURE); 2892 #endif 2893 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2894 optlen += TCPOLEN_SACKHDR; 2895 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2896 optlen = PAD(optlen); 2897 } 2898 } else { 2899 if (tp->t_flags & TF_REQ_TSTMP) 2900 optlen = TCPOLEN_TSTAMP_APPA; 2901 else 2902 optlen = PAD(TCPOLEN_MAXSEG); 2903 if (tp->t_flags & TF_REQ_SCALE) 2904 optlen += PAD(TCPOLEN_WINDOW); 2905 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2906 if (tp->t_flags & TF_SIGNATURE) 2907 optlen += PAD(TCPOLEN_SIGNATURE); 2908 #endif 2909 if (tp->t_flags & TF_SACK_PERMIT) 2910 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2911 } 2912 #undef PAD 2913 optlen = min(optlen, TCP_MAXOLEN); 2914 return (tp->t_maxseg - optlen); 2915 } 2916 2917 static int 2918 sysctl_drop(SYSCTL_HANDLER_ARGS) 2919 { 2920 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2921 struct sockaddr_storage addrs[2]; 2922 struct inpcb *inp; 2923 struct tcpcb *tp; 2924 struct tcptw *tw; 2925 struct sockaddr_in *fin, *lin; 2926 #ifdef INET6 2927 struct sockaddr_in6 *fin6, *lin6; 2928 #endif 2929 int error; 2930 2931 inp = NULL; 2932 fin = lin = NULL; 2933 #ifdef INET6 2934 fin6 = lin6 = NULL; 2935 #endif 2936 error = 0; 2937 2938 if (req->oldptr != NULL || req->oldlen != 0) 2939 return (EINVAL); 2940 if (req->newptr == NULL) 2941 return (EPERM); 2942 if (req->newlen < sizeof(addrs)) 2943 return (ENOMEM); 2944 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2945 if (error) 2946 return (error); 2947 2948 switch (addrs[0].ss_family) { 2949 #ifdef INET6 2950 case AF_INET6: 2951 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2952 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2953 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2954 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2955 return (EINVAL); 2956 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2957 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2958 return (EINVAL); 2959 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2960 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2961 fin = (struct sockaddr_in *)&addrs[0]; 2962 lin = (struct sockaddr_in *)&addrs[1]; 2963 break; 2964 } 2965 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2966 if (error) 2967 return (error); 2968 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2969 if (error) 2970 return (error); 2971 break; 2972 #endif 2973 #ifdef INET 2974 case AF_INET: 2975 fin = (struct sockaddr_in *)&addrs[0]; 2976 lin = (struct sockaddr_in *)&addrs[1]; 2977 if (fin->sin_len != sizeof(struct sockaddr_in) || 2978 lin->sin_len != sizeof(struct sockaddr_in)) 2979 return (EINVAL); 2980 break; 2981 #endif 2982 default: 2983 return (EINVAL); 2984 } 2985 INP_INFO_RLOCK(&V_tcbinfo); 2986 switch (addrs[0].ss_family) { 2987 #ifdef INET6 2988 case AF_INET6: 2989 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2990 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2991 INPLOOKUP_WLOCKPCB, NULL); 2992 break; 2993 #endif 2994 #ifdef INET 2995 case AF_INET: 2996 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2997 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2998 break; 2999 #endif 3000 } 3001 if (inp != NULL) { 3002 if (inp->inp_flags & INP_TIMEWAIT) { 3003 /* 3004 * XXXRW: There currently exists a state where an 3005 * inpcb is present, but its timewait state has been 3006 * discarded. For now, don't allow dropping of this 3007 * type of inpcb. 3008 */ 3009 tw = intotw(inp); 3010 if (tw != NULL) 3011 tcp_twclose(tw, 0); 3012 else 3013 INP_WUNLOCK(inp); 3014 } else if (!(inp->inp_flags & INP_DROPPED) && 3015 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3016 tp = intotcpcb(inp); 3017 tp = tcp_drop(tp, ECONNABORTED); 3018 if (tp != NULL) 3019 INP_WUNLOCK(inp); 3020 } else 3021 INP_WUNLOCK(inp); 3022 } else 3023 error = ESRCH; 3024 INP_INFO_RUNLOCK(&V_tcbinfo); 3025 return (error); 3026 } 3027 3028 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3029 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3030 0, sysctl_drop, "", "Drop TCP connection"); 3031 3032 /* 3033 * Generate a standardized TCP log line for use throughout the 3034 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3035 * allow use in the interrupt context. 3036 * 3037 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3038 * NB: The function may return NULL if memory allocation failed. 3039 * 3040 * Due to header inclusion and ordering limitations the struct ip 3041 * and ip6_hdr pointers have to be passed as void pointers. 3042 */ 3043 char * 3044 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3045 const void *ip6hdr) 3046 { 3047 3048 /* Is logging enabled? */ 3049 if (tcp_log_in_vain == 0) 3050 return (NULL); 3051 3052 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3053 } 3054 3055 char * 3056 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3057 const void *ip6hdr) 3058 { 3059 3060 /* Is logging enabled? */ 3061 if (tcp_log_debug == 0) 3062 return (NULL); 3063 3064 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3065 } 3066 3067 static char * 3068 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3069 const void *ip6hdr) 3070 { 3071 char *s, *sp; 3072 size_t size; 3073 struct ip *ip; 3074 #ifdef INET6 3075 const struct ip6_hdr *ip6; 3076 3077 ip6 = (const struct ip6_hdr *)ip6hdr; 3078 #endif /* INET6 */ 3079 ip = (struct ip *)ip4hdr; 3080 3081 /* 3082 * The log line looks like this: 3083 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3084 */ 3085 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3086 sizeof(PRINT_TH_FLAGS) + 1 + 3087 #ifdef INET6 3088 2 * INET6_ADDRSTRLEN; 3089 #else 3090 2 * INET_ADDRSTRLEN; 3091 #endif /* INET6 */ 3092 3093 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3094 if (s == NULL) 3095 return (NULL); 3096 3097 strcat(s, "TCP: ["); 3098 sp = s + strlen(s); 3099 3100 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3101 inet_ntoa_r(inc->inc_faddr, sp); 3102 sp = s + strlen(s); 3103 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3104 sp = s + strlen(s); 3105 inet_ntoa_r(inc->inc_laddr, sp); 3106 sp = s + strlen(s); 3107 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3108 #ifdef INET6 3109 } else if (inc) { 3110 ip6_sprintf(sp, &inc->inc6_faddr); 3111 sp = s + strlen(s); 3112 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3113 sp = s + strlen(s); 3114 ip6_sprintf(sp, &inc->inc6_laddr); 3115 sp = s + strlen(s); 3116 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3117 } else if (ip6 && th) { 3118 ip6_sprintf(sp, &ip6->ip6_src); 3119 sp = s + strlen(s); 3120 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3121 sp = s + strlen(s); 3122 ip6_sprintf(sp, &ip6->ip6_dst); 3123 sp = s + strlen(s); 3124 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3125 #endif /* INET6 */ 3126 #ifdef INET 3127 } else if (ip && th) { 3128 inet_ntoa_r(ip->ip_src, sp); 3129 sp = s + strlen(s); 3130 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3131 sp = s + strlen(s); 3132 inet_ntoa_r(ip->ip_dst, sp); 3133 sp = s + strlen(s); 3134 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3135 #endif /* INET */ 3136 } else { 3137 free(s, M_TCPLOG); 3138 return (NULL); 3139 } 3140 sp = s + strlen(s); 3141 if (th) 3142 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3143 if (*(s + size - 1) != '\0') 3144 panic("%s: string too long", __func__); 3145 return (s); 3146 } 3147 3148 /* 3149 * A subroutine which makes it easy to track TCP state changes with DTrace. 3150 * This function shouldn't be called for t_state initializations that don't 3151 * correspond to actual TCP state transitions. 3152 */ 3153 void 3154 tcp_state_change(struct tcpcb *tp, int newstate) 3155 { 3156 #if defined(KDTRACE_HOOKS) 3157 int pstate = tp->t_state; 3158 #endif 3159 3160 TCPSTATES_DEC(tp->t_state); 3161 TCPSTATES_INC(newstate); 3162 tp->t_state = newstate; 3163 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3164 } 3165 3166 /* 3167 * Create an external-format (``xtcpcb'') structure using the information in 3168 * the kernel-format tcpcb structure pointed to by tp. This is done to 3169 * reduce the spew of irrelevant information over this interface, to isolate 3170 * user code from changes in the kernel structure, and potentially to provide 3171 * information-hiding if we decide that some of this information should be 3172 * hidden from users. 3173 */ 3174 void 3175 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3176 { 3177 struct tcpcb *tp = intotcpcb(inp); 3178 sbintime_t now; 3179 3180 if (inp->inp_flags & INP_TIMEWAIT) { 3181 bzero(xt, sizeof(struct xtcpcb)); 3182 xt->t_state = TCPS_TIME_WAIT; 3183 } else { 3184 xt->t_state = tp->t_state; 3185 xt->t_logstate = tp->t_logstate; 3186 xt->t_flags = tp->t_flags; 3187 xt->t_sndzerowin = tp->t_sndzerowin; 3188 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3189 xt->t_rcvoopack = tp->t_rcvoopack; 3190 3191 now = getsbinuptime(); 3192 #define COPYTIMER(ttt) do { \ 3193 if (callout_active(&tp->t_timers->ttt)) \ 3194 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3195 SBT_1MS; \ 3196 else \ 3197 xt->ttt = 0; \ 3198 } while (0) 3199 COPYTIMER(tt_delack); 3200 COPYTIMER(tt_rexmt); 3201 COPYTIMER(tt_persist); 3202 COPYTIMER(tt_keep); 3203 COPYTIMER(tt_2msl); 3204 #undef COPYTIMER 3205 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3206 3207 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3208 TCP_FUNCTION_NAME_LEN_MAX); 3209 bzero(xt->xt_logid, TCP_LOG_ID_LEN); 3210 #ifdef TCP_BLACKBOX 3211 (void)tcp_log_get_id(tp, xt->xt_logid); 3212 #endif 3213 } 3214 3215 xt->xt_len = sizeof(struct xtcpcb); 3216 in_pcbtoxinpcb(inp, &xt->xt_inp); 3217 if (inp->inp_socket == NULL) 3218 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3219 } 3220