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 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 200 &VNET_NAME(tcp_ts_offset_per_conn), 0, 201 "Initialize TCP timestamps per connection instead of per host pair"); 202 203 static int tcp_log_debug = 0; 204 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 205 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 206 207 static int tcp_tcbhashsize; 208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 209 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 210 211 static int do_tcpdrain = 1; 212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 213 "Enable tcp_drain routine for extra help when low on mbufs"); 214 215 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 216 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 217 218 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 219 #define V_icmp_may_rst VNET(icmp_may_rst) 220 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 221 &VNET_NAME(icmp_may_rst), 0, 222 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 223 224 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 225 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 227 &VNET_NAME(tcp_isn_reseed_interval), 0, 228 "Seconds between reseeding of ISN secret"); 229 230 static int tcp_soreceive_stream; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 232 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 233 234 VNET_DEFINE(uma_zone_t, sack_hole_zone); 235 #define V_sack_hole_zone VNET(sack_hole_zone) 236 237 #ifdef TCP_HHOOK 238 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 239 #endif 240 241 #define TS_OFFSET_SECRET_LENGTH 32 242 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 243 #define V_ts_offset_secret VNET(ts_offset_secret) 244 245 static int tcp_default_fb_init(struct tcpcb *tp); 246 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 247 static int tcp_default_handoff_ok(struct tcpcb *tp); 248 static struct inpcb *tcp_notify(struct inpcb *, int); 249 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 250 static void tcp_mtudisc(struct inpcb *, int); 251 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 252 void *ip4hdr, const void *ip6hdr); 253 254 255 static struct tcp_function_block tcp_def_funcblk = { 256 .tfb_tcp_block_name = "freebsd", 257 .tfb_tcp_output = tcp_output, 258 .tfb_tcp_do_segment = tcp_do_segment, 259 .tfb_tcp_ctloutput = tcp_default_ctloutput, 260 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 261 .tfb_tcp_fb_init = tcp_default_fb_init, 262 .tfb_tcp_fb_fini = tcp_default_fb_fini, 263 }; 264 265 static int tcp_fb_cnt = 0; 266 struct tcp_funchead t_functions; 267 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 268 269 static struct tcp_function_block * 270 find_tcp_functions_locked(struct tcp_function_set *fs) 271 { 272 struct tcp_function *f; 273 struct tcp_function_block *blk=NULL; 274 275 TAILQ_FOREACH(f, &t_functions, tf_next) { 276 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 277 blk = f->tf_fb; 278 break; 279 } 280 } 281 return(blk); 282 } 283 284 static struct tcp_function_block * 285 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 286 { 287 struct tcp_function_block *rblk=NULL; 288 struct tcp_function *f; 289 290 TAILQ_FOREACH(f, &t_functions, tf_next) { 291 if (f->tf_fb == blk) { 292 rblk = blk; 293 if (s) { 294 *s = f; 295 } 296 break; 297 } 298 } 299 return (rblk); 300 } 301 302 struct tcp_function_block * 303 find_and_ref_tcp_functions(struct tcp_function_set *fs) 304 { 305 struct tcp_function_block *blk; 306 307 rw_rlock(&tcp_function_lock); 308 blk = find_tcp_functions_locked(fs); 309 if (blk) 310 refcount_acquire(&blk->tfb_refcnt); 311 rw_runlock(&tcp_function_lock); 312 return(blk); 313 } 314 315 struct tcp_function_block * 316 find_and_ref_tcp_fb(struct tcp_function_block *blk) 317 { 318 struct tcp_function_block *rblk; 319 320 rw_rlock(&tcp_function_lock); 321 rblk = find_tcp_fb_locked(blk, NULL); 322 if (rblk) 323 refcount_acquire(&rblk->tfb_refcnt); 324 rw_runlock(&tcp_function_lock); 325 return(rblk); 326 } 327 328 static struct tcp_function_block * 329 find_and_ref_tcp_default_fb(void) 330 { 331 struct tcp_function_block *rblk; 332 333 rw_rlock(&tcp_function_lock); 334 rblk = tcp_func_set_ptr; 335 refcount_acquire(&rblk->tfb_refcnt); 336 rw_runlock(&tcp_function_lock); 337 return (rblk); 338 } 339 340 void 341 tcp_switch_back_to_default(struct tcpcb *tp) 342 { 343 struct tcp_function_block *tfb; 344 345 KASSERT(tp->t_fb != &tcp_def_funcblk, 346 ("%s: called by the built-in default stack", __func__)); 347 348 /* 349 * Release the old stack. This function will either find a new one 350 * or panic. 351 */ 352 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 353 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 354 refcount_release(&tp->t_fb->tfb_refcnt); 355 356 /* 357 * Now, we'll find a new function block to use. 358 * Start by trying the current user-selected 359 * default, unless this stack is the user-selected 360 * default. 361 */ 362 tfb = find_and_ref_tcp_default_fb(); 363 if (tfb == tp->t_fb) { 364 refcount_release(&tfb->tfb_refcnt); 365 tfb = NULL; 366 } 367 /* Does the stack accept this connection? */ 368 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 369 (*tfb->tfb_tcp_handoff_ok)(tp)) { 370 refcount_release(&tfb->tfb_refcnt); 371 tfb = NULL; 372 } 373 /* Try to use that stack. */ 374 if (tfb != NULL) { 375 /* Initialize the new stack. If it succeeds, we are done. */ 376 tp->t_fb = tfb; 377 if (tp->t_fb->tfb_tcp_fb_init == NULL || 378 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 379 return; 380 381 /* 382 * Initialization failed. Release the reference count on 383 * the stack. 384 */ 385 refcount_release(&tfb->tfb_refcnt); 386 } 387 388 /* 389 * If that wasn't feasible, use the built-in default 390 * stack which is not allowed to reject anyone. 391 */ 392 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 393 if (tfb == NULL) { 394 /* there always should be a default */ 395 panic("Can't refer to tcp_def_funcblk"); 396 } 397 if (tfb->tfb_tcp_handoff_ok != NULL) { 398 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 399 /* The default stack cannot say no */ 400 panic("Default stack rejects a new session?"); 401 } 402 } 403 tp->t_fb = tfb; 404 if (tp->t_fb->tfb_tcp_fb_init != NULL && 405 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 406 /* The default stack cannot fail */ 407 panic("Default stack initialization failed"); 408 } 409 } 410 411 static int 412 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 413 { 414 int error=ENOENT; 415 struct tcp_function_set fs; 416 struct tcp_function_block *blk; 417 418 memset(&fs, 0, sizeof(fs)); 419 rw_rlock(&tcp_function_lock); 420 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 421 if (blk) { 422 /* Found him */ 423 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 424 fs.pcbcnt = blk->tfb_refcnt; 425 } 426 rw_runlock(&tcp_function_lock); 427 error = sysctl_handle_string(oidp, fs.function_set_name, 428 sizeof(fs.function_set_name), req); 429 430 /* Check for error or no change */ 431 if (error != 0 || req->newptr == NULL) 432 return(error); 433 434 rw_wlock(&tcp_function_lock); 435 blk = find_tcp_functions_locked(&fs); 436 if ((blk == NULL) || 437 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 438 error = ENOENT; 439 goto done; 440 } 441 tcp_func_set_ptr = blk; 442 done: 443 rw_wunlock(&tcp_function_lock); 444 return (error); 445 } 446 447 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 448 CTLTYPE_STRING | CTLFLAG_RW, 449 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 450 "Set/get the default TCP functions"); 451 452 static int 453 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 454 { 455 int error, cnt, linesz; 456 struct tcp_function *f; 457 char *buffer, *cp; 458 size_t bufsz, outsz; 459 bool alias; 460 461 cnt = 0; 462 rw_rlock(&tcp_function_lock); 463 TAILQ_FOREACH(f, &t_functions, tf_next) { 464 cnt++; 465 } 466 rw_runlock(&tcp_function_lock); 467 468 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 469 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 470 471 error = 0; 472 cp = buffer; 473 474 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 475 "Alias", "PCB count"); 476 cp += linesz; 477 bufsz -= linesz; 478 outsz = linesz; 479 480 rw_rlock(&tcp_function_lock); 481 TAILQ_FOREACH(f, &t_functions, tf_next) { 482 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 483 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 484 f->tf_fb->tfb_tcp_block_name, 485 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 486 alias ? f->tf_name : "-", 487 f->tf_fb->tfb_refcnt); 488 if (linesz >= bufsz) { 489 error = EOVERFLOW; 490 break; 491 } 492 cp += linesz; 493 bufsz -= linesz; 494 outsz += linesz; 495 } 496 rw_runlock(&tcp_function_lock); 497 if (error == 0) 498 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 499 free(buffer, M_TEMP); 500 return (error); 501 } 502 503 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 504 CTLTYPE_STRING|CTLFLAG_RD, 505 NULL, 0, sysctl_net_inet_list_available, "A", 506 "list available TCP Function sets"); 507 508 /* 509 * Exports one (struct tcp_function_info) for each alias/name. 510 */ 511 static int 512 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 513 { 514 int cnt, error; 515 struct tcp_function *f; 516 struct tcp_function_info tfi; 517 518 /* 519 * We don't allow writes. 520 */ 521 if (req->newptr != NULL) 522 return (EINVAL); 523 524 /* 525 * Wire the old buffer so we can directly copy the functions to 526 * user space without dropping the lock. 527 */ 528 if (req->oldptr != NULL) { 529 error = sysctl_wire_old_buffer(req, 0); 530 if (error) 531 return (error); 532 } 533 534 /* 535 * Walk the list and copy out matching entries. If INVARIANTS 536 * is compiled in, also walk the list to verify the length of 537 * the list matches what we have recorded. 538 */ 539 rw_rlock(&tcp_function_lock); 540 541 cnt = 0; 542 #ifndef INVARIANTS 543 if (req->oldptr == NULL) { 544 cnt = tcp_fb_cnt; 545 goto skip_loop; 546 } 547 #endif 548 TAILQ_FOREACH(f, &t_functions, tf_next) { 549 #ifdef INVARIANTS 550 cnt++; 551 #endif 552 if (req->oldptr != NULL) { 553 bzero(&tfi, sizeof(tfi)); 554 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 555 tfi.tfi_id = f->tf_fb->tfb_id; 556 (void)strlcpy(tfi.tfi_alias, f->tf_name, 557 sizeof(tfi.tfi_alias)); 558 (void)strlcpy(tfi.tfi_name, 559 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 560 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 561 /* 562 * Don't stop on error, as that is the 563 * mechanism we use to accumulate length 564 * information if the buffer was too short. 565 */ 566 } 567 } 568 KASSERT(cnt == tcp_fb_cnt, 569 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 570 #ifndef INVARIANTS 571 skip_loop: 572 #endif 573 rw_runlock(&tcp_function_lock); 574 if (req->oldptr == NULL) 575 error = SYSCTL_OUT(req, NULL, 576 (cnt + 1) * sizeof(struct tcp_function_info)); 577 578 return (error); 579 } 580 581 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 582 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 583 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 584 "List TCP function block name-to-ID mappings"); 585 586 /* 587 * tfb_tcp_handoff_ok() function for the default stack. 588 * Note that we'll basically try to take all comers. 589 */ 590 static int 591 tcp_default_handoff_ok(struct tcpcb *tp) 592 { 593 594 return (0); 595 } 596 597 /* 598 * tfb_tcp_fb_init() function for the default stack. 599 * 600 * This handles making sure we have appropriate timers set if you are 601 * transitioning a socket that has some amount of setup done. 602 * 603 * The init() fuction from the default can *never* return non-zero i.e. 604 * it is required to always succeed since it is the stack of last resort! 605 */ 606 static int 607 tcp_default_fb_init(struct tcpcb *tp) 608 { 609 610 struct socket *so; 611 612 INP_WLOCK_ASSERT(tp->t_inpcb); 613 614 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 615 ("%s: connection %p in unexpected state %d", __func__, tp, 616 tp->t_state)); 617 618 /* 619 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 620 * know what to do for unexpected states (which includes TIME_WAIT). 621 */ 622 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 623 return (0); 624 625 /* 626 * Make sure some kind of transmission timer is set if there is 627 * outstanding data. 628 */ 629 so = tp->t_inpcb->inp_socket; 630 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 631 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 632 tcp_timer_active(tp, TT_PERSIST))) { 633 /* 634 * If the session has established and it looks like it should 635 * be in the persist state, set the persist timer. Otherwise, 636 * set the retransmit timer. 637 */ 638 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 639 (int32_t)(tp->snd_nxt - tp->snd_una) < 640 (int32_t)sbavail(&so->so_snd)) 641 tcp_setpersist(tp); 642 else 643 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 644 } 645 646 /* All non-embryonic sessions get a keepalive timer. */ 647 if (!tcp_timer_active(tp, TT_KEEP)) 648 tcp_timer_activate(tp, TT_KEEP, 649 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 650 TP_KEEPINIT(tp)); 651 652 return (0); 653 } 654 655 /* 656 * tfb_tcp_fb_fini() function for the default stack. 657 * 658 * This changes state as necessary (or prudent) to prepare for another stack 659 * to assume responsibility for the connection. 660 */ 661 static void 662 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 663 { 664 665 INP_WLOCK_ASSERT(tp->t_inpcb); 666 return; 667 } 668 669 /* 670 * Target size of TCP PCB hash tables. Must be a power of two. 671 * 672 * Note that this can be overridden by the kernel environment 673 * variable net.inet.tcp.tcbhashsize 674 */ 675 #ifndef TCBHASHSIZE 676 #define TCBHASHSIZE 0 677 #endif 678 679 /* 680 * XXX 681 * Callouts should be moved into struct tcp directly. They are currently 682 * separate because the tcpcb structure is exported to userland for sysctl 683 * parsing purposes, which do not know about callouts. 684 */ 685 struct tcpcb_mem { 686 struct tcpcb tcb; 687 struct tcp_timer tt; 688 struct cc_var ccv; 689 #ifdef TCP_HHOOK 690 struct osd osd; 691 #endif 692 }; 693 694 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 695 #define V_tcpcb_zone VNET(tcpcb_zone) 696 697 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 698 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 699 700 static struct mtx isn_mtx; 701 702 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 703 #define ISN_LOCK() mtx_lock(&isn_mtx) 704 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 705 706 /* 707 * TCP initialization. 708 */ 709 static void 710 tcp_zone_change(void *tag) 711 { 712 713 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 714 uma_zone_set_max(V_tcpcb_zone, maxsockets); 715 tcp_tw_zone_change(); 716 } 717 718 static int 719 tcp_inpcb_init(void *mem, int size, int flags) 720 { 721 struct inpcb *inp = mem; 722 723 INP_LOCK_INIT(inp, "inp", "tcpinp"); 724 return (0); 725 } 726 727 /* 728 * Take a value and get the next power of 2 that doesn't overflow. 729 * Used to size the tcp_inpcb hash buckets. 730 */ 731 static int 732 maketcp_hashsize(int size) 733 { 734 int hashsize; 735 736 /* 737 * auto tune. 738 * get the next power of 2 higher than maxsockets. 739 */ 740 hashsize = 1 << fls(size); 741 /* catch overflow, and just go one power of 2 smaller */ 742 if (hashsize < size) { 743 hashsize = 1 << (fls(size) - 1); 744 } 745 return (hashsize); 746 } 747 748 static volatile int next_tcp_stack_id = 1; 749 750 /* 751 * Register a TCP function block with the name provided in the names 752 * array. (Note that this function does NOT automatically register 753 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 754 * explicitly include blk->tfb_tcp_block_name in the list of names if 755 * you wish to register the stack with that name.) 756 * 757 * Either all name registrations will succeed or all will fail. If 758 * a name registration fails, the function will update the num_names 759 * argument to point to the array index of the name that encountered 760 * the failure. 761 * 762 * Returns 0 on success, or an error code on failure. 763 */ 764 int 765 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 766 const char *names[], int *num_names) 767 { 768 struct tcp_function *n; 769 struct tcp_function_set fs; 770 int error, i; 771 772 KASSERT(names != NULL && *num_names > 0, 773 ("%s: Called with 0-length name list", __func__)); 774 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 775 KASSERT(rw_initialized(&tcp_function_lock), 776 ("%s: called too early", __func__)); 777 778 if ((blk->tfb_tcp_output == NULL) || 779 (blk->tfb_tcp_do_segment == NULL) || 780 (blk->tfb_tcp_ctloutput == NULL) || 781 (strlen(blk->tfb_tcp_block_name) == 0)) { 782 /* 783 * These functions are required and you 784 * need a name. 785 */ 786 *num_names = 0; 787 return (EINVAL); 788 } 789 if (blk->tfb_tcp_timer_stop_all || 790 blk->tfb_tcp_timer_activate || 791 blk->tfb_tcp_timer_active || 792 blk->tfb_tcp_timer_stop) { 793 /* 794 * If you define one timer function you 795 * must have them all. 796 */ 797 if ((blk->tfb_tcp_timer_stop_all == NULL) || 798 (blk->tfb_tcp_timer_activate == NULL) || 799 (blk->tfb_tcp_timer_active == NULL) || 800 (blk->tfb_tcp_timer_stop == NULL)) { 801 *num_names = 0; 802 return (EINVAL); 803 } 804 } 805 806 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 807 *num_names = 0; 808 return (EINVAL); 809 } 810 811 refcount_init(&blk->tfb_refcnt, 0); 812 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 813 for (i = 0; i < *num_names; i++) { 814 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 815 if (n == NULL) { 816 error = ENOMEM; 817 goto cleanup; 818 } 819 n->tf_fb = blk; 820 821 (void)strlcpy(fs.function_set_name, names[i], 822 sizeof(fs.function_set_name)); 823 rw_wlock(&tcp_function_lock); 824 if (find_tcp_functions_locked(&fs) != NULL) { 825 /* Duplicate name space not allowed */ 826 rw_wunlock(&tcp_function_lock); 827 free(n, M_TCPFUNCTIONS); 828 error = EALREADY; 829 goto cleanup; 830 } 831 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 832 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 833 tcp_fb_cnt++; 834 rw_wunlock(&tcp_function_lock); 835 } 836 return(0); 837 838 cleanup: 839 /* 840 * Deregister the names we just added. Because registration failed 841 * for names[i], we don't need to deregister that name. 842 */ 843 *num_names = i; 844 rw_wlock(&tcp_function_lock); 845 while (--i >= 0) { 846 TAILQ_FOREACH(n, &t_functions, tf_next) { 847 if (!strncmp(n->tf_name, names[i], 848 TCP_FUNCTION_NAME_LEN_MAX)) { 849 TAILQ_REMOVE(&t_functions, n, tf_next); 850 tcp_fb_cnt--; 851 n->tf_fb = NULL; 852 free(n, M_TCPFUNCTIONS); 853 break; 854 } 855 } 856 } 857 rw_wunlock(&tcp_function_lock); 858 return (error); 859 } 860 861 /* 862 * Register a TCP function block using the name provided in the name 863 * argument. 864 * 865 * Returns 0 on success, or an error code on failure. 866 */ 867 int 868 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 869 int wait) 870 { 871 const char *name_list[1]; 872 int num_names, rv; 873 874 num_names = 1; 875 if (name != NULL) 876 name_list[0] = name; 877 else 878 name_list[0] = blk->tfb_tcp_block_name; 879 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 880 return (rv); 881 } 882 883 /* 884 * Register a TCP function block using the name defined in 885 * blk->tfb_tcp_block_name. 886 * 887 * Returns 0 on success, or an error code on failure. 888 */ 889 int 890 register_tcp_functions(struct tcp_function_block *blk, int wait) 891 { 892 893 return (register_tcp_functions_as_name(blk, NULL, wait)); 894 } 895 896 /* 897 * Deregister all names associated with a function block. This 898 * functionally removes the function block from use within the system. 899 * 900 * When called with a true quiesce argument, mark the function block 901 * as being removed so no more stacks will use it and determine 902 * whether the removal would succeed. 903 * 904 * When called with a false quiesce argument, actually attempt the 905 * removal. 906 * 907 * When called with a force argument, attempt to switch all TCBs to 908 * use the default stack instead of returning EBUSY. 909 * 910 * Returns 0 on success (or if the removal would succeed, or an error 911 * code on failure. 912 */ 913 int 914 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 915 bool force) 916 { 917 struct tcp_function *f; 918 919 if (blk == &tcp_def_funcblk) { 920 /* You can't un-register the default */ 921 return (EPERM); 922 } 923 rw_wlock(&tcp_function_lock); 924 if (blk == tcp_func_set_ptr) { 925 /* You can't free the current default */ 926 rw_wunlock(&tcp_function_lock); 927 return (EBUSY); 928 } 929 /* Mark the block so no more stacks can use it. */ 930 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 931 /* 932 * If TCBs are still attached to the stack, attempt to switch them 933 * to the default stack. 934 */ 935 if (force && blk->tfb_refcnt) { 936 struct inpcb *inp; 937 struct tcpcb *tp; 938 VNET_ITERATOR_DECL(vnet_iter); 939 940 rw_wunlock(&tcp_function_lock); 941 942 VNET_LIST_RLOCK(); 943 VNET_FOREACH(vnet_iter) { 944 CURVNET_SET(vnet_iter); 945 INP_INFO_WLOCK(&V_tcbinfo); 946 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 947 INP_WLOCK(inp); 948 if (inp->inp_flags & INP_TIMEWAIT) { 949 INP_WUNLOCK(inp); 950 continue; 951 } 952 tp = intotcpcb(inp); 953 if (tp == NULL || tp->t_fb != blk) { 954 INP_WUNLOCK(inp); 955 continue; 956 } 957 tcp_switch_back_to_default(tp); 958 INP_WUNLOCK(inp); 959 } 960 INP_INFO_WUNLOCK(&V_tcbinfo); 961 CURVNET_RESTORE(); 962 } 963 VNET_LIST_RUNLOCK(); 964 965 rw_wlock(&tcp_function_lock); 966 } 967 if (blk->tfb_refcnt) { 968 /* TCBs still attached. */ 969 rw_wunlock(&tcp_function_lock); 970 return (EBUSY); 971 } 972 if (quiesce) { 973 /* Skip removal. */ 974 rw_wunlock(&tcp_function_lock); 975 return (0); 976 } 977 /* Remove any function names that map to this function block. */ 978 while (find_tcp_fb_locked(blk, &f) != NULL) { 979 TAILQ_REMOVE(&t_functions, f, tf_next); 980 tcp_fb_cnt--; 981 f->tf_fb = NULL; 982 free(f, M_TCPFUNCTIONS); 983 } 984 rw_wunlock(&tcp_function_lock); 985 return (0); 986 } 987 988 void 989 tcp_init(void) 990 { 991 const char *tcbhash_tuneable; 992 int hashsize; 993 994 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 995 996 #ifdef TCP_HHOOK 997 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 998 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 999 printf("%s: WARNING: unable to register helper hook\n", __func__); 1000 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1001 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1002 printf("%s: WARNING: unable to register helper hook\n", __func__); 1003 #endif 1004 hashsize = TCBHASHSIZE; 1005 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1006 if (hashsize == 0) { 1007 /* 1008 * Auto tune the hash size based on maxsockets. 1009 * A perfect hash would have a 1:1 mapping 1010 * (hashsize = maxsockets) however it's been 1011 * suggested that O(2) average is better. 1012 */ 1013 hashsize = maketcp_hashsize(maxsockets / 4); 1014 /* 1015 * Our historical default is 512, 1016 * do not autotune lower than this. 1017 */ 1018 if (hashsize < 512) 1019 hashsize = 512; 1020 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1021 printf("%s: %s auto tuned to %d\n", __func__, 1022 tcbhash_tuneable, hashsize); 1023 } 1024 /* 1025 * We require a hashsize to be a power of two. 1026 * Previously if it was not a power of two we would just reset it 1027 * back to 512, which could be a nasty surprise if you did not notice 1028 * the error message. 1029 * Instead what we do is clip it to the closest power of two lower 1030 * than the specified hash value. 1031 */ 1032 if (!powerof2(hashsize)) { 1033 int oldhashsize = hashsize; 1034 1035 hashsize = maketcp_hashsize(hashsize); 1036 /* prevent absurdly low value */ 1037 if (hashsize < 16) 1038 hashsize = 16; 1039 printf("%s: WARNING: TCB hash size not a power of 2, " 1040 "clipped from %d to %d.\n", __func__, oldhashsize, 1041 hashsize); 1042 } 1043 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1044 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1045 1046 /* 1047 * These have to be type stable for the benefit of the timers. 1048 */ 1049 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1050 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1051 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1052 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1053 1054 tcp_tw_init(); 1055 syncache_init(); 1056 tcp_hc_init(); 1057 1058 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1059 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1060 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1061 1062 tcp_fastopen_init(); 1063 1064 /* Skip initialization of globals for non-default instances. */ 1065 if (!IS_DEFAULT_VNET(curvnet)) 1066 return; 1067 1068 tcp_reass_global_init(); 1069 1070 /* XXX virtualize those bellow? */ 1071 tcp_delacktime = TCPTV_DELACK; 1072 tcp_keepinit = TCPTV_KEEP_INIT; 1073 tcp_keepidle = TCPTV_KEEP_IDLE; 1074 tcp_keepintvl = TCPTV_KEEPINTVL; 1075 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1076 tcp_msl = TCPTV_MSL; 1077 tcp_rexmit_initial = TCPTV_RTOBASE; 1078 if (tcp_rexmit_initial < 1) 1079 tcp_rexmit_initial = 1; 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 1089 /* Setup the tcp function block list */ 1090 TAILQ_INIT(&t_functions); 1091 rw_init(&tcp_function_lock, "tcp_func_lock"); 1092 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1093 #ifdef TCP_BLACKBOX 1094 /* Initialize the TCP logging data. */ 1095 tcp_log_init(); 1096 #endif 1097 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1098 1099 if (tcp_soreceive_stream) { 1100 #ifdef INET 1101 tcp_usrreqs.pru_soreceive = soreceive_stream; 1102 #endif 1103 #ifdef INET6 1104 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1105 #endif /* INET6 */ 1106 } 1107 1108 #ifdef INET6 1109 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1110 #else /* INET6 */ 1111 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1112 #endif /* INET6 */ 1113 if (max_protohdr < TCP_MINPROTOHDR) 1114 max_protohdr = TCP_MINPROTOHDR; 1115 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1116 panic("tcp_init"); 1117 #undef TCP_MINPROTOHDR 1118 1119 ISN_LOCK_INIT(); 1120 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1121 SHUTDOWN_PRI_DEFAULT); 1122 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1123 EVENTHANDLER_PRI_ANY); 1124 #ifdef TCPPCAP 1125 tcp_pcap_init(); 1126 #endif 1127 } 1128 1129 #ifdef VIMAGE 1130 static void 1131 tcp_destroy(void *unused __unused) 1132 { 1133 int n; 1134 #ifdef TCP_HHOOK 1135 int error; 1136 #endif 1137 1138 /* 1139 * All our processes are gone, all our sockets should be cleaned 1140 * up, which means, we should be past the tcp_discardcb() calls. 1141 * Sleep to let all tcpcb timers really disappear and cleanup. 1142 */ 1143 for (;;) { 1144 INP_LIST_RLOCK(&V_tcbinfo); 1145 n = V_tcbinfo.ipi_count; 1146 INP_LIST_RUNLOCK(&V_tcbinfo); 1147 if (n == 0) 1148 break; 1149 pause("tcpdes", hz / 10); 1150 } 1151 tcp_hc_destroy(); 1152 syncache_destroy(); 1153 tcp_tw_destroy(); 1154 in_pcbinfo_destroy(&V_tcbinfo); 1155 /* tcp_discardcb() clears the sack_holes up. */ 1156 uma_zdestroy(V_sack_hole_zone); 1157 uma_zdestroy(V_tcpcb_zone); 1158 1159 /* 1160 * Cannot free the zone until all tcpcbs are released as we attach 1161 * the allocations to them. 1162 */ 1163 tcp_fastopen_destroy(); 1164 1165 #ifdef TCP_HHOOK 1166 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1167 if (error != 0) { 1168 printf("%s: WARNING: unable to deregister helper hook " 1169 "type=%d, id=%d: error %d returned\n", __func__, 1170 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1171 } 1172 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1173 if (error != 0) { 1174 printf("%s: WARNING: unable to deregister helper hook " 1175 "type=%d, id=%d: error %d returned\n", __func__, 1176 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1177 } 1178 #endif 1179 } 1180 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1181 #endif 1182 1183 void 1184 tcp_fini(void *xtp) 1185 { 1186 1187 } 1188 1189 /* 1190 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1191 * tcp_template used to store this data in mbufs, but we now recopy it out 1192 * of the tcpcb each time to conserve mbufs. 1193 */ 1194 void 1195 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1196 { 1197 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1198 1199 INP_WLOCK_ASSERT(inp); 1200 1201 #ifdef INET6 1202 if ((inp->inp_vflag & INP_IPV6) != 0) { 1203 struct ip6_hdr *ip6; 1204 1205 ip6 = (struct ip6_hdr *)ip_ptr; 1206 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1207 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1208 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1209 (IPV6_VERSION & IPV6_VERSION_MASK); 1210 ip6->ip6_nxt = IPPROTO_TCP; 1211 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1212 ip6->ip6_src = inp->in6p_laddr; 1213 ip6->ip6_dst = inp->in6p_faddr; 1214 } 1215 #endif /* INET6 */ 1216 #if defined(INET6) && defined(INET) 1217 else 1218 #endif 1219 #ifdef INET 1220 { 1221 struct ip *ip; 1222 1223 ip = (struct ip *)ip_ptr; 1224 ip->ip_v = IPVERSION; 1225 ip->ip_hl = 5; 1226 ip->ip_tos = inp->inp_ip_tos; 1227 ip->ip_len = 0; 1228 ip->ip_id = 0; 1229 ip->ip_off = 0; 1230 ip->ip_ttl = inp->inp_ip_ttl; 1231 ip->ip_sum = 0; 1232 ip->ip_p = IPPROTO_TCP; 1233 ip->ip_src = inp->inp_laddr; 1234 ip->ip_dst = inp->inp_faddr; 1235 } 1236 #endif /* INET */ 1237 th->th_sport = inp->inp_lport; 1238 th->th_dport = inp->inp_fport; 1239 th->th_seq = 0; 1240 th->th_ack = 0; 1241 th->th_x2 = 0; 1242 th->th_off = 5; 1243 th->th_flags = 0; 1244 th->th_win = 0; 1245 th->th_urp = 0; 1246 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1247 } 1248 1249 /* 1250 * Create template to be used to send tcp packets on a connection. 1251 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1252 * use for this function is in keepalives, which use tcp_respond. 1253 */ 1254 struct tcptemp * 1255 tcpip_maketemplate(struct inpcb *inp) 1256 { 1257 struct tcptemp *t; 1258 1259 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1260 if (t == NULL) 1261 return (NULL); 1262 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1263 return (t); 1264 } 1265 1266 /* 1267 * Send a single message to the TCP at address specified by 1268 * the given TCP/IP header. If m == NULL, then we make a copy 1269 * of the tcpiphdr at th and send directly to the addressed host. 1270 * This is used to force keep alive messages out using the TCP 1271 * template for a connection. If flags are given then we send 1272 * a message back to the TCP which originated the segment th, 1273 * and discard the mbuf containing it and any other attached mbufs. 1274 * 1275 * In any case the ack and sequence number of the transmitted 1276 * segment are as specified by the parameters. 1277 * 1278 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1279 */ 1280 void 1281 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1282 tcp_seq ack, tcp_seq seq, int flags) 1283 { 1284 struct tcpopt to; 1285 struct inpcb *inp; 1286 struct ip *ip; 1287 struct mbuf *optm; 1288 struct tcphdr *nth; 1289 u_char *optp; 1290 #ifdef INET6 1291 struct ip6_hdr *ip6; 1292 int isipv6; 1293 #endif /* INET6 */ 1294 int optlen, tlen, win; 1295 bool incl_opts; 1296 1297 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1298 1299 #ifdef INET6 1300 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1301 ip6 = ipgen; 1302 #endif /* INET6 */ 1303 ip = ipgen; 1304 1305 if (tp != NULL) { 1306 inp = tp->t_inpcb; 1307 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1308 INP_WLOCK_ASSERT(inp); 1309 } else 1310 inp = NULL; 1311 1312 incl_opts = false; 1313 win = 0; 1314 if (tp != NULL) { 1315 if (!(flags & TH_RST)) { 1316 win = sbspace(&inp->inp_socket->so_rcv); 1317 if (win > TCP_MAXWIN << tp->rcv_scale) 1318 win = TCP_MAXWIN << tp->rcv_scale; 1319 } 1320 if ((tp->t_flags & TF_NOOPT) == 0) 1321 incl_opts = true; 1322 } 1323 if (m == NULL) { 1324 m = m_gethdr(M_NOWAIT, MT_DATA); 1325 if (m == NULL) 1326 return; 1327 m->m_data += max_linkhdr; 1328 #ifdef INET6 1329 if (isipv6) { 1330 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1331 sizeof(struct ip6_hdr)); 1332 ip6 = mtod(m, struct ip6_hdr *); 1333 nth = (struct tcphdr *)(ip6 + 1); 1334 } else 1335 #endif /* INET6 */ 1336 { 1337 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1338 ip = mtod(m, struct ip *); 1339 nth = (struct tcphdr *)(ip + 1); 1340 } 1341 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1342 flags = TH_ACK; 1343 } else if (!M_WRITABLE(m)) { 1344 struct mbuf *n; 1345 1346 /* Can't reuse 'm', allocate a new mbuf. */ 1347 n = m_gethdr(M_NOWAIT, MT_DATA); 1348 if (n == NULL) { 1349 m_freem(m); 1350 return; 1351 } 1352 1353 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1354 m_freem(m); 1355 m_freem(n); 1356 return; 1357 } 1358 1359 n->m_data += max_linkhdr; 1360 /* m_len is set later */ 1361 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1362 #ifdef INET6 1363 if (isipv6) { 1364 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1365 sizeof(struct ip6_hdr)); 1366 ip6 = mtod(n, struct ip6_hdr *); 1367 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1368 nth = (struct tcphdr *)(ip6 + 1); 1369 } else 1370 #endif /* INET6 */ 1371 { 1372 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1373 ip = mtod(n, struct ip *); 1374 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1375 nth = (struct tcphdr *)(ip + 1); 1376 } 1377 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1378 xchg(nth->th_dport, nth->th_sport, uint16_t); 1379 th = nth; 1380 m_freem(m); 1381 m = n; 1382 } else { 1383 /* 1384 * reuse the mbuf. 1385 * XXX MRT We inherit the FIB, which is lucky. 1386 */ 1387 m_freem(m->m_next); 1388 m->m_next = NULL; 1389 m->m_data = (caddr_t)ipgen; 1390 /* m_len is set later */ 1391 #ifdef INET6 1392 if (isipv6) { 1393 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1394 nth = (struct tcphdr *)(ip6 + 1); 1395 } else 1396 #endif /* INET6 */ 1397 { 1398 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1399 nth = (struct tcphdr *)(ip + 1); 1400 } 1401 if (th != nth) { 1402 /* 1403 * this is usually a case when an extension header 1404 * exists between the IPv6 header and the 1405 * TCP header. 1406 */ 1407 nth->th_sport = th->th_sport; 1408 nth->th_dport = th->th_dport; 1409 } 1410 xchg(nth->th_dport, nth->th_sport, uint16_t); 1411 #undef xchg 1412 } 1413 tlen = 0; 1414 #ifdef INET6 1415 if (isipv6) 1416 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1417 #endif 1418 #if defined(INET) && defined(INET6) 1419 else 1420 #endif 1421 #ifdef INET 1422 tlen = sizeof (struct tcpiphdr); 1423 #endif 1424 #ifdef INVARIANTS 1425 m->m_len = 0; 1426 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1427 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1428 m, tlen, (long)M_TRAILINGSPACE(m))); 1429 #endif 1430 m->m_len = tlen; 1431 to.to_flags = 0; 1432 if (incl_opts) { 1433 /* Make sure we have room. */ 1434 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1435 m->m_next = m_get(M_NOWAIT, MT_DATA); 1436 if (m->m_next) { 1437 optp = mtod(m->m_next, u_char *); 1438 optm = m->m_next; 1439 } else 1440 incl_opts = false; 1441 } else { 1442 optp = (u_char *) (nth + 1); 1443 optm = m; 1444 } 1445 } 1446 if (incl_opts) { 1447 /* Timestamps. */ 1448 if (tp->t_flags & TF_RCVD_TSTMP) { 1449 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1450 to.to_tsecr = tp->ts_recent; 1451 to.to_flags |= TOF_TS; 1452 } 1453 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1454 /* TCP-MD5 (RFC2385). */ 1455 if (tp->t_flags & TF_SIGNATURE) 1456 to.to_flags |= TOF_SIGNATURE; 1457 #endif 1458 /* Add the options. */ 1459 tlen += optlen = tcp_addoptions(&to, optp); 1460 1461 /* Update m_len in the correct mbuf. */ 1462 optm->m_len += optlen; 1463 } else 1464 optlen = 0; 1465 #ifdef INET6 1466 if (isipv6) { 1467 ip6->ip6_flow = 0; 1468 ip6->ip6_vfc = IPV6_VERSION; 1469 ip6->ip6_nxt = IPPROTO_TCP; 1470 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1471 } 1472 #endif 1473 #if defined(INET) && defined(INET6) 1474 else 1475 #endif 1476 #ifdef INET 1477 { 1478 ip->ip_len = htons(tlen); 1479 ip->ip_ttl = V_ip_defttl; 1480 if (V_path_mtu_discovery) 1481 ip->ip_off |= htons(IP_DF); 1482 } 1483 #endif 1484 m->m_pkthdr.len = tlen; 1485 m->m_pkthdr.rcvif = NULL; 1486 #ifdef MAC 1487 if (inp != NULL) { 1488 /* 1489 * Packet is associated with a socket, so allow the 1490 * label of the response to reflect the socket label. 1491 */ 1492 INP_WLOCK_ASSERT(inp); 1493 mac_inpcb_create_mbuf(inp, m); 1494 } else { 1495 /* 1496 * Packet is not associated with a socket, so possibly 1497 * update the label in place. 1498 */ 1499 mac_netinet_tcp_reply(m); 1500 } 1501 #endif 1502 nth->th_seq = htonl(seq); 1503 nth->th_ack = htonl(ack); 1504 nth->th_x2 = 0; 1505 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1506 nth->th_flags = flags; 1507 if (tp != NULL) 1508 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1509 else 1510 nth->th_win = htons((u_short)win); 1511 nth->th_urp = 0; 1512 1513 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1514 if (to.to_flags & TOF_SIGNATURE) { 1515 if (!TCPMD5_ENABLED() || 1516 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1517 m_freem(m); 1518 return; 1519 } 1520 } 1521 #endif 1522 1523 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1524 #ifdef INET6 1525 if (isipv6) { 1526 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1527 nth->th_sum = in6_cksum_pseudo(ip6, 1528 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1529 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1530 NULL, NULL); 1531 } 1532 #endif /* INET6 */ 1533 #if defined(INET6) && defined(INET) 1534 else 1535 #endif 1536 #ifdef INET 1537 { 1538 m->m_pkthdr.csum_flags = CSUM_TCP; 1539 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1540 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1541 } 1542 #endif /* INET */ 1543 #ifdef TCPDEBUG 1544 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1545 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1546 #endif 1547 TCP_PROBE3(debug__output, tp, th, m); 1548 if (flags & TH_RST) 1549 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1550 1551 #ifdef INET6 1552 if (isipv6) { 1553 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1554 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1555 } 1556 #endif /* INET6 */ 1557 #if defined(INET) && defined(INET6) 1558 else 1559 #endif 1560 #ifdef INET 1561 { 1562 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1563 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1564 } 1565 #endif 1566 } 1567 1568 /* 1569 * Create a new TCP control block, making an 1570 * empty reassembly queue and hooking it to the argument 1571 * protocol control block. The `inp' parameter must have 1572 * come from the zone allocator set up in tcp_init(). 1573 */ 1574 struct tcpcb * 1575 tcp_newtcpcb(struct inpcb *inp) 1576 { 1577 struct tcpcb_mem *tm; 1578 struct tcpcb *tp; 1579 #ifdef INET6 1580 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1581 #endif /* INET6 */ 1582 1583 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1584 if (tm == NULL) 1585 return (NULL); 1586 tp = &tm->tcb; 1587 1588 /* Initialise cc_var struct for this tcpcb. */ 1589 tp->ccv = &tm->ccv; 1590 tp->ccv->type = IPPROTO_TCP; 1591 tp->ccv->ccvc.tcp = tp; 1592 rw_rlock(&tcp_function_lock); 1593 tp->t_fb = tcp_func_set_ptr; 1594 refcount_acquire(&tp->t_fb->tfb_refcnt); 1595 rw_runlock(&tcp_function_lock); 1596 /* 1597 * Use the current system default CC algorithm. 1598 */ 1599 CC_LIST_RLOCK(); 1600 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1601 CC_ALGO(tp) = CC_DEFAULT(); 1602 CC_LIST_RUNLOCK(); 1603 1604 if (CC_ALGO(tp)->cb_init != NULL) 1605 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1606 if (tp->t_fb->tfb_tcp_fb_fini) 1607 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1608 refcount_release(&tp->t_fb->tfb_refcnt); 1609 uma_zfree(V_tcpcb_zone, tm); 1610 return (NULL); 1611 } 1612 1613 #ifdef TCP_HHOOK 1614 tp->osd = &tm->osd; 1615 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1616 if (tp->t_fb->tfb_tcp_fb_fini) 1617 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1618 refcount_release(&tp->t_fb->tfb_refcnt); 1619 uma_zfree(V_tcpcb_zone, tm); 1620 return (NULL); 1621 } 1622 #endif 1623 1624 #ifdef VIMAGE 1625 tp->t_vnet = inp->inp_vnet; 1626 #endif 1627 tp->t_timers = &tm->tt; 1628 TAILQ_INIT(&tp->t_segq); 1629 tp->t_maxseg = 1630 #ifdef INET6 1631 isipv6 ? V_tcp_v6mssdflt : 1632 #endif /* INET6 */ 1633 V_tcp_mssdflt; 1634 1635 /* Set up our timeouts. */ 1636 callout_init(&tp->t_timers->tt_rexmt, 1); 1637 callout_init(&tp->t_timers->tt_persist, 1); 1638 callout_init(&tp->t_timers->tt_keep, 1); 1639 callout_init(&tp->t_timers->tt_2msl, 1); 1640 callout_init(&tp->t_timers->tt_delack, 1); 1641 1642 if (V_tcp_do_rfc1323) 1643 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1644 if (V_tcp_do_sack) 1645 tp->t_flags |= TF_SACK_PERMIT; 1646 TAILQ_INIT(&tp->snd_holes); 1647 /* 1648 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1649 * is called. 1650 */ 1651 in_pcbref(inp); /* Reference for tcpcb */ 1652 tp->t_inpcb = inp; 1653 1654 /* 1655 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1656 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1657 * reasonable initial retransmit time. 1658 */ 1659 tp->t_srtt = TCPTV_SRTTBASE; 1660 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1661 tp->t_rttmin = tcp_rexmit_min; 1662 tp->t_rxtcur = tcp_rexmit_initial; 1663 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1664 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1665 tp->t_rcvtime = ticks; 1666 /* 1667 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1668 * because the socket may be bound to an IPv6 wildcard address, 1669 * which may match an IPv4-mapped IPv6 address. 1670 */ 1671 inp->inp_ip_ttl = V_ip_defttl; 1672 inp->inp_ppcb = tp; 1673 #ifdef TCPPCAP 1674 /* 1675 * Init the TCP PCAP queues. 1676 */ 1677 tcp_pcap_tcpcb_init(tp); 1678 #endif 1679 #ifdef TCP_BLACKBOX 1680 /* Initialize the per-TCPCB log data. */ 1681 tcp_log_tcpcbinit(tp); 1682 #endif 1683 if (tp->t_fb->tfb_tcp_fb_init) { 1684 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1685 } 1686 return (tp); /* XXX */ 1687 } 1688 1689 /* 1690 * Switch the congestion control algorithm back to NewReno for any active 1691 * control blocks using an algorithm which is about to go away. 1692 * This ensures the CC framework can allow the unload to proceed without leaving 1693 * any dangling pointers which would trigger a panic. 1694 * Returning non-zero would inform the CC framework that something went wrong 1695 * and it would be unsafe to allow the unload to proceed. However, there is no 1696 * way for this to occur with this implementation so we always return zero. 1697 */ 1698 int 1699 tcp_ccalgounload(struct cc_algo *unload_algo) 1700 { 1701 struct cc_algo *tmpalgo; 1702 struct inpcb *inp; 1703 struct tcpcb *tp; 1704 VNET_ITERATOR_DECL(vnet_iter); 1705 1706 /* 1707 * Check all active control blocks across all network stacks and change 1708 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1709 * requires cleanup code to be run, call it. 1710 */ 1711 VNET_LIST_RLOCK(); 1712 VNET_FOREACH(vnet_iter) { 1713 CURVNET_SET(vnet_iter); 1714 INP_INFO_WLOCK(&V_tcbinfo); 1715 /* 1716 * New connections already part way through being initialised 1717 * with the CC algo we're removing will not race with this code 1718 * because the INP_INFO_WLOCK is held during initialisation. We 1719 * therefore don't enter the loop below until the connection 1720 * list has stabilised. 1721 */ 1722 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1723 INP_WLOCK(inp); 1724 /* Important to skip tcptw structs. */ 1725 if (!(inp->inp_flags & INP_TIMEWAIT) && 1726 (tp = intotcpcb(inp)) != NULL) { 1727 /* 1728 * By holding INP_WLOCK here, we are assured 1729 * that the connection is not currently 1730 * executing inside the CC module's functions 1731 * i.e. it is safe to make the switch back to 1732 * NewReno. 1733 */ 1734 if (CC_ALGO(tp) == unload_algo) { 1735 tmpalgo = CC_ALGO(tp); 1736 if (tmpalgo->cb_destroy != NULL) 1737 tmpalgo->cb_destroy(tp->ccv); 1738 CC_DATA(tp) = NULL; 1739 /* 1740 * NewReno may allocate memory on 1741 * demand for certain stateful 1742 * configuration as needed, but is 1743 * coded to never fail on memory 1744 * allocation failure so it is a safe 1745 * fallback. 1746 */ 1747 CC_ALGO(tp) = &newreno_cc_algo; 1748 } 1749 } 1750 INP_WUNLOCK(inp); 1751 } 1752 INP_INFO_WUNLOCK(&V_tcbinfo); 1753 CURVNET_RESTORE(); 1754 } 1755 VNET_LIST_RUNLOCK(); 1756 1757 return (0); 1758 } 1759 1760 /* 1761 * Drop a TCP connection, reporting 1762 * the specified error. If connection is synchronized, 1763 * then send a RST to peer. 1764 */ 1765 struct tcpcb * 1766 tcp_drop(struct tcpcb *tp, int errno) 1767 { 1768 struct socket *so = tp->t_inpcb->inp_socket; 1769 1770 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1771 INP_WLOCK_ASSERT(tp->t_inpcb); 1772 1773 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1774 tcp_state_change(tp, TCPS_CLOSED); 1775 (void) tp->t_fb->tfb_tcp_output(tp); 1776 TCPSTAT_INC(tcps_drops); 1777 } else 1778 TCPSTAT_INC(tcps_conndrops); 1779 if (errno == ETIMEDOUT && tp->t_softerror) 1780 errno = tp->t_softerror; 1781 so->so_error = errno; 1782 return (tcp_close(tp)); 1783 } 1784 1785 void 1786 tcp_discardcb(struct tcpcb *tp) 1787 { 1788 struct inpcb *inp = tp->t_inpcb; 1789 struct socket *so = inp->inp_socket; 1790 #ifdef INET6 1791 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1792 #endif /* INET6 */ 1793 int released __unused; 1794 1795 INP_WLOCK_ASSERT(inp); 1796 1797 /* 1798 * Make sure that all of our timers are stopped before we delete the 1799 * PCB. 1800 * 1801 * If stopping a timer fails, we schedule a discard function in same 1802 * callout, and the last discard function called will take care of 1803 * deleting the tcpcb. 1804 */ 1805 tp->t_timers->tt_draincnt = 0; 1806 tcp_timer_stop(tp, TT_REXMT); 1807 tcp_timer_stop(tp, TT_PERSIST); 1808 tcp_timer_stop(tp, TT_KEEP); 1809 tcp_timer_stop(tp, TT_2MSL); 1810 tcp_timer_stop(tp, TT_DELACK); 1811 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1812 /* 1813 * Call the stop-all function of the methods, 1814 * this function should call the tcp_timer_stop() 1815 * method with each of the function specific timeouts. 1816 * That stop will be called via the tfb_tcp_timer_stop() 1817 * which should use the async drain function of the 1818 * callout system (see tcp_var.h). 1819 */ 1820 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1821 } 1822 1823 /* 1824 * If we got enough samples through the srtt filter, 1825 * save the rtt and rttvar in the routing entry. 1826 * 'Enough' is arbitrarily defined as 4 rtt samples. 1827 * 4 samples is enough for the srtt filter to converge 1828 * to within enough % of the correct value; fewer samples 1829 * and we could save a bogus rtt. The danger is not high 1830 * as tcp quickly recovers from everything. 1831 * XXX: Works very well but needs some more statistics! 1832 */ 1833 if (tp->t_rttupdated >= 4) { 1834 struct hc_metrics_lite metrics; 1835 uint32_t ssthresh; 1836 1837 bzero(&metrics, sizeof(metrics)); 1838 /* 1839 * Update the ssthresh always when the conditions below 1840 * are satisfied. This gives us better new start value 1841 * for the congestion avoidance for new connections. 1842 * ssthresh is only set if packet loss occurred on a session. 1843 * 1844 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1845 * being torn down. Ideally this code would not use 'so'. 1846 */ 1847 ssthresh = tp->snd_ssthresh; 1848 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1849 /* 1850 * convert the limit from user data bytes to 1851 * packets then to packet data bytes. 1852 */ 1853 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1854 if (ssthresh < 2) 1855 ssthresh = 2; 1856 ssthresh *= (tp->t_maxseg + 1857 #ifdef INET6 1858 (isipv6 ? sizeof (struct ip6_hdr) + 1859 sizeof (struct tcphdr) : 1860 #endif 1861 sizeof (struct tcpiphdr) 1862 #ifdef INET6 1863 ) 1864 #endif 1865 ); 1866 } else 1867 ssthresh = 0; 1868 metrics.rmx_ssthresh = ssthresh; 1869 1870 metrics.rmx_rtt = tp->t_srtt; 1871 metrics.rmx_rttvar = tp->t_rttvar; 1872 metrics.rmx_cwnd = tp->snd_cwnd; 1873 metrics.rmx_sendpipe = 0; 1874 metrics.rmx_recvpipe = 0; 1875 1876 tcp_hc_update(&inp->inp_inc, &metrics); 1877 } 1878 1879 /* free the reassembly queue, if any */ 1880 tcp_reass_flush(tp); 1881 1882 #ifdef TCP_OFFLOAD 1883 /* Disconnect offload device, if any. */ 1884 if (tp->t_flags & TF_TOE) 1885 tcp_offload_detach(tp); 1886 #endif 1887 1888 tcp_free_sackholes(tp); 1889 1890 #ifdef TCPPCAP 1891 /* Free the TCP PCAP queues. */ 1892 tcp_pcap_drain(&(tp->t_inpkts)); 1893 tcp_pcap_drain(&(tp->t_outpkts)); 1894 #endif 1895 1896 /* Allow the CC algorithm to clean up after itself. */ 1897 if (CC_ALGO(tp)->cb_destroy != NULL) 1898 CC_ALGO(tp)->cb_destroy(tp->ccv); 1899 CC_DATA(tp) = NULL; 1900 1901 #ifdef TCP_HHOOK 1902 khelp_destroy_osd(tp->osd); 1903 #endif 1904 1905 CC_ALGO(tp) = NULL; 1906 inp->inp_ppcb = NULL; 1907 if (tp->t_timers->tt_draincnt == 0) { 1908 /* We own the last reference on tcpcb, let's free it. */ 1909 #ifdef TCP_BLACKBOX 1910 tcp_log_tcpcbfini(tp); 1911 #endif 1912 TCPSTATES_DEC(tp->t_state); 1913 if (tp->t_fb->tfb_tcp_fb_fini) 1914 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1915 refcount_release(&tp->t_fb->tfb_refcnt); 1916 tp->t_inpcb = NULL; 1917 uma_zfree(V_tcpcb_zone, tp); 1918 released = in_pcbrele_wlocked(inp); 1919 KASSERT(!released, ("%s: inp %p should not have been released " 1920 "here", __func__, inp)); 1921 } 1922 } 1923 1924 void 1925 tcp_timer_discard(void *ptp) 1926 { 1927 struct inpcb *inp; 1928 struct tcpcb *tp; 1929 struct epoch_tracker et; 1930 1931 tp = (struct tcpcb *)ptp; 1932 CURVNET_SET(tp->t_vnet); 1933 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 1934 inp = tp->t_inpcb; 1935 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1936 __func__, tp)); 1937 INP_WLOCK(inp); 1938 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1939 ("%s: tcpcb has to be stopped here", __func__)); 1940 tp->t_timers->tt_draincnt--; 1941 if (tp->t_timers->tt_draincnt == 0) { 1942 /* We own the last reference on this tcpcb, let's free it. */ 1943 #ifdef TCP_BLACKBOX 1944 tcp_log_tcpcbfini(tp); 1945 #endif 1946 TCPSTATES_DEC(tp->t_state); 1947 if (tp->t_fb->tfb_tcp_fb_fini) 1948 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1949 refcount_release(&tp->t_fb->tfb_refcnt); 1950 tp->t_inpcb = NULL; 1951 uma_zfree(V_tcpcb_zone, tp); 1952 if (in_pcbrele_wlocked(inp)) { 1953 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1954 CURVNET_RESTORE(); 1955 return; 1956 } 1957 } 1958 INP_WUNLOCK(inp); 1959 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1960 CURVNET_RESTORE(); 1961 } 1962 1963 /* 1964 * Attempt to close a TCP control block, marking it as dropped, and freeing 1965 * the socket if we hold the only reference. 1966 */ 1967 struct tcpcb * 1968 tcp_close(struct tcpcb *tp) 1969 { 1970 struct inpcb *inp = tp->t_inpcb; 1971 struct socket *so; 1972 1973 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1974 INP_WLOCK_ASSERT(inp); 1975 1976 #ifdef TCP_OFFLOAD 1977 if (tp->t_state == TCPS_LISTEN) 1978 tcp_offload_listen_stop(tp); 1979 #endif 1980 /* 1981 * This releases the TFO pending counter resource for TFO listen 1982 * sockets as well as passively-created TFO sockets that transition 1983 * from SYN_RECEIVED to CLOSED. 1984 */ 1985 if (tp->t_tfo_pending) { 1986 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1987 tp->t_tfo_pending = NULL; 1988 } 1989 in_pcbdrop(inp); 1990 TCPSTAT_INC(tcps_closed); 1991 if (tp->t_state != TCPS_CLOSED) 1992 tcp_state_change(tp, TCPS_CLOSED); 1993 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1994 so = inp->inp_socket; 1995 soisdisconnected(so); 1996 if (inp->inp_flags & INP_SOCKREF) { 1997 KASSERT(so->so_state & SS_PROTOREF, 1998 ("tcp_close: !SS_PROTOREF")); 1999 inp->inp_flags &= ~INP_SOCKREF; 2000 INP_WUNLOCK(inp); 2001 SOCK_LOCK(so); 2002 so->so_state &= ~SS_PROTOREF; 2003 sofree(so); 2004 return (NULL); 2005 } 2006 return (tp); 2007 } 2008 2009 void 2010 tcp_drain(void) 2011 { 2012 VNET_ITERATOR_DECL(vnet_iter); 2013 2014 if (!do_tcpdrain) 2015 return; 2016 2017 VNET_LIST_RLOCK_NOSLEEP(); 2018 VNET_FOREACH(vnet_iter) { 2019 CURVNET_SET(vnet_iter); 2020 struct inpcb *inpb; 2021 struct tcpcb *tcpb; 2022 2023 /* 2024 * Walk the tcpbs, if existing, and flush the reassembly queue, 2025 * if there is one... 2026 * XXX: The "Net/3" implementation doesn't imply that the TCP 2027 * reassembly queue should be flushed, but in a situation 2028 * where we're really low on mbufs, this is potentially 2029 * useful. 2030 */ 2031 INP_INFO_WLOCK(&V_tcbinfo); 2032 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2033 INP_WLOCK(inpb); 2034 if (inpb->inp_flags & INP_TIMEWAIT) { 2035 INP_WUNLOCK(inpb); 2036 continue; 2037 } 2038 if ((tcpb = intotcpcb(inpb)) != NULL) { 2039 tcp_reass_flush(tcpb); 2040 tcp_clean_sackreport(tcpb); 2041 #ifdef TCP_BLACKBOX 2042 tcp_log_drain(tcpb); 2043 #endif 2044 #ifdef TCPPCAP 2045 if (tcp_pcap_aggressive_free) { 2046 /* Free the TCP PCAP queues. */ 2047 tcp_pcap_drain(&(tcpb->t_inpkts)); 2048 tcp_pcap_drain(&(tcpb->t_outpkts)); 2049 } 2050 #endif 2051 } 2052 INP_WUNLOCK(inpb); 2053 } 2054 INP_INFO_WUNLOCK(&V_tcbinfo); 2055 CURVNET_RESTORE(); 2056 } 2057 VNET_LIST_RUNLOCK_NOSLEEP(); 2058 } 2059 2060 /* 2061 * Notify a tcp user of an asynchronous error; 2062 * store error as soft error, but wake up user 2063 * (for now, won't do anything until can select for soft error). 2064 * 2065 * Do not wake up user since there currently is no mechanism for 2066 * reporting soft errors (yet - a kqueue filter may be added). 2067 */ 2068 static struct inpcb * 2069 tcp_notify(struct inpcb *inp, int error) 2070 { 2071 struct tcpcb *tp; 2072 2073 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2074 INP_WLOCK_ASSERT(inp); 2075 2076 if ((inp->inp_flags & INP_TIMEWAIT) || 2077 (inp->inp_flags & INP_DROPPED)) 2078 return (inp); 2079 2080 tp = intotcpcb(inp); 2081 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2082 2083 /* 2084 * Ignore some errors if we are hooked up. 2085 * If connection hasn't completed, has retransmitted several times, 2086 * and receives a second error, give up now. This is better 2087 * than waiting a long time to establish a connection that 2088 * can never complete. 2089 */ 2090 if (tp->t_state == TCPS_ESTABLISHED && 2091 (error == EHOSTUNREACH || error == ENETUNREACH || 2092 error == EHOSTDOWN)) { 2093 if (inp->inp_route.ro_rt) { 2094 RTFREE(inp->inp_route.ro_rt); 2095 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2096 } 2097 return (inp); 2098 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2099 tp->t_softerror) { 2100 tp = tcp_drop(tp, error); 2101 if (tp != NULL) 2102 return (inp); 2103 else 2104 return (NULL); 2105 } else { 2106 tp->t_softerror = error; 2107 return (inp); 2108 } 2109 #if 0 2110 wakeup( &so->so_timeo); 2111 sorwakeup(so); 2112 sowwakeup(so); 2113 #endif 2114 } 2115 2116 static int 2117 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2118 { 2119 int error, i, m, n, pcb_count; 2120 struct inpcb *inp, **inp_list; 2121 inp_gen_t gencnt; 2122 struct xinpgen xig; 2123 struct epoch_tracker et; 2124 2125 /* 2126 * The process of preparing the TCB list is too time-consuming and 2127 * resource-intensive to repeat twice on every request. 2128 */ 2129 if (req->oldptr == NULL) { 2130 n = V_tcbinfo.ipi_count + 2131 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2132 n += imax(n / 8, 10); 2133 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2134 return (0); 2135 } 2136 2137 if (req->newptr != NULL) 2138 return (EPERM); 2139 2140 /* 2141 * OK, now we're committed to doing something. 2142 */ 2143 INP_LIST_RLOCK(&V_tcbinfo); 2144 gencnt = V_tcbinfo.ipi_gencnt; 2145 n = V_tcbinfo.ipi_count; 2146 INP_LIST_RUNLOCK(&V_tcbinfo); 2147 2148 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2149 2150 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2151 + (n + m) * sizeof(struct xtcpcb)); 2152 if (error != 0) 2153 return (error); 2154 2155 bzero(&xig, sizeof(xig)); 2156 xig.xig_len = sizeof xig; 2157 xig.xig_count = n + m; 2158 xig.xig_gen = gencnt; 2159 xig.xig_sogen = so_gencnt; 2160 error = SYSCTL_OUT(req, &xig, sizeof xig); 2161 if (error) 2162 return (error); 2163 2164 error = syncache_pcblist(req, m, &pcb_count); 2165 if (error) 2166 return (error); 2167 2168 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2169 2170 INP_INFO_WLOCK(&V_tcbinfo); 2171 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2172 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) { 2173 INP_WLOCK(inp); 2174 if (inp->inp_gencnt <= gencnt) { 2175 /* 2176 * XXX: This use of cr_cansee(), introduced with 2177 * TCP state changes, is not quite right, but for 2178 * now, better than nothing. 2179 */ 2180 if (inp->inp_flags & INP_TIMEWAIT) { 2181 if (intotw(inp) != NULL) 2182 error = cr_cansee(req->td->td_ucred, 2183 intotw(inp)->tw_cred); 2184 else 2185 error = EINVAL; /* Skip this inp. */ 2186 } else 2187 error = cr_canseeinpcb(req->td->td_ucred, inp); 2188 if (error == 0) { 2189 in_pcbref(inp); 2190 inp_list[i++] = inp; 2191 } 2192 } 2193 INP_WUNLOCK(inp); 2194 } 2195 INP_INFO_WUNLOCK(&V_tcbinfo); 2196 n = i; 2197 2198 error = 0; 2199 for (i = 0; i < n; i++) { 2200 inp = inp_list[i]; 2201 INP_RLOCK(inp); 2202 if (inp->inp_gencnt <= gencnt) { 2203 struct xtcpcb xt; 2204 2205 tcp_inptoxtp(inp, &xt); 2206 INP_RUNLOCK(inp); 2207 error = SYSCTL_OUT(req, &xt, sizeof xt); 2208 } else 2209 INP_RUNLOCK(inp); 2210 } 2211 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2212 for (i = 0; i < n; i++) { 2213 inp = inp_list[i]; 2214 INP_RLOCK(inp); 2215 if (!in_pcbrele_rlocked(inp)) 2216 INP_RUNLOCK(inp); 2217 } 2218 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2219 2220 if (!error) { 2221 /* 2222 * Give the user an updated idea of our state. 2223 * If the generation differs from what we told 2224 * her before, she knows that something happened 2225 * while we were processing this request, and it 2226 * might be necessary to retry. 2227 */ 2228 INP_LIST_RLOCK(&V_tcbinfo); 2229 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2230 xig.xig_sogen = so_gencnt; 2231 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2232 INP_LIST_RUNLOCK(&V_tcbinfo); 2233 error = SYSCTL_OUT(req, &xig, sizeof xig); 2234 } 2235 free(inp_list, M_TEMP); 2236 return (error); 2237 } 2238 2239 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2240 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2241 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2242 2243 #ifdef INET 2244 static int 2245 tcp_getcred(SYSCTL_HANDLER_ARGS) 2246 { 2247 struct xucred xuc; 2248 struct sockaddr_in addrs[2]; 2249 struct inpcb *inp; 2250 int error; 2251 2252 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2253 if (error) 2254 return (error); 2255 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2256 if (error) 2257 return (error); 2258 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2259 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2260 if (inp != NULL) { 2261 if (inp->inp_socket == NULL) 2262 error = ENOENT; 2263 if (error == 0) 2264 error = cr_canseeinpcb(req->td->td_ucred, inp); 2265 if (error == 0) 2266 cru2x(inp->inp_cred, &xuc); 2267 INP_RUNLOCK(inp); 2268 } else 2269 error = ENOENT; 2270 if (error == 0) 2271 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2272 return (error); 2273 } 2274 2275 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2276 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2277 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2278 #endif /* INET */ 2279 2280 #ifdef INET6 2281 static int 2282 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2283 { 2284 struct xucred xuc; 2285 struct sockaddr_in6 addrs[2]; 2286 struct inpcb *inp; 2287 int error; 2288 #ifdef INET 2289 int mapped = 0; 2290 #endif 2291 2292 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2293 if (error) 2294 return (error); 2295 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2296 if (error) 2297 return (error); 2298 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2299 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2300 return (error); 2301 } 2302 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2303 #ifdef INET 2304 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2305 mapped = 1; 2306 else 2307 #endif 2308 return (EINVAL); 2309 } 2310 2311 #ifdef INET 2312 if (mapped == 1) 2313 inp = in_pcblookup(&V_tcbinfo, 2314 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2315 addrs[1].sin6_port, 2316 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2317 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2318 else 2319 #endif 2320 inp = in6_pcblookup(&V_tcbinfo, 2321 &addrs[1].sin6_addr, addrs[1].sin6_port, 2322 &addrs[0].sin6_addr, addrs[0].sin6_port, 2323 INPLOOKUP_RLOCKPCB, NULL); 2324 if (inp != NULL) { 2325 if (inp->inp_socket == NULL) 2326 error = ENOENT; 2327 if (error == 0) 2328 error = cr_canseeinpcb(req->td->td_ucred, inp); 2329 if (error == 0) 2330 cru2x(inp->inp_cred, &xuc); 2331 INP_RUNLOCK(inp); 2332 } else 2333 error = ENOENT; 2334 if (error == 0) 2335 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2336 return (error); 2337 } 2338 2339 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2340 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2341 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2342 #endif /* INET6 */ 2343 2344 2345 #ifdef INET 2346 void 2347 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2348 { 2349 struct ip *ip = vip; 2350 struct tcphdr *th; 2351 struct in_addr faddr; 2352 struct inpcb *inp; 2353 struct tcpcb *tp; 2354 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2355 struct icmp *icp; 2356 struct in_conninfo inc; 2357 struct epoch_tracker et; 2358 tcp_seq icmp_tcp_seq; 2359 int mtu; 2360 2361 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2362 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2363 return; 2364 2365 if (cmd == PRC_MSGSIZE) 2366 notify = tcp_mtudisc_notify; 2367 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2368 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2369 cmd == PRC_TIMXCEED_INTRANS) && ip) 2370 notify = tcp_drop_syn_sent; 2371 2372 /* 2373 * Hostdead is ugly because it goes linearly through all PCBs. 2374 * XXX: We never get this from ICMP, otherwise it makes an 2375 * excellent DoS attack on machines with many connections. 2376 */ 2377 else if (cmd == PRC_HOSTDEAD) 2378 ip = NULL; 2379 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2380 return; 2381 2382 if (ip == NULL) { 2383 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2384 return; 2385 } 2386 2387 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2388 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2389 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2390 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2391 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2392 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2393 /* signal EHOSTDOWN, as it flushes the cached route */ 2394 inp = (*notify)(inp, EHOSTDOWN); 2395 goto out; 2396 } 2397 icmp_tcp_seq = th->th_seq; 2398 if (inp != NULL) { 2399 if (!(inp->inp_flags & INP_TIMEWAIT) && 2400 !(inp->inp_flags & INP_DROPPED) && 2401 !(inp->inp_socket == NULL)) { 2402 tp = intotcpcb(inp); 2403 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2404 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2405 if (cmd == PRC_MSGSIZE) { 2406 /* 2407 * MTU discovery: 2408 * If we got a needfrag set the MTU 2409 * in the route to the suggested new 2410 * value (if given) and then notify. 2411 */ 2412 mtu = ntohs(icp->icmp_nextmtu); 2413 /* 2414 * If no alternative MTU was 2415 * proposed, try the next smaller 2416 * one. 2417 */ 2418 if (!mtu) 2419 mtu = ip_next_mtu( 2420 ntohs(ip->ip_len), 1); 2421 if (mtu < V_tcp_minmss + 2422 sizeof(struct tcpiphdr)) 2423 mtu = V_tcp_minmss + 2424 sizeof(struct tcpiphdr); 2425 /* 2426 * Only process the offered MTU if it 2427 * is smaller than the current one. 2428 */ 2429 if (mtu < tp->t_maxseg + 2430 sizeof(struct tcpiphdr)) { 2431 bzero(&inc, sizeof(inc)); 2432 inc.inc_faddr = faddr; 2433 inc.inc_fibnum = 2434 inp->inp_inc.inc_fibnum; 2435 tcp_hc_updatemtu(&inc, mtu); 2436 tcp_mtudisc(inp, mtu); 2437 } 2438 } else 2439 inp = (*notify)(inp, 2440 inetctlerrmap[cmd]); 2441 } 2442 } 2443 } else { 2444 bzero(&inc, sizeof(inc)); 2445 inc.inc_fport = th->th_dport; 2446 inc.inc_lport = th->th_sport; 2447 inc.inc_faddr = faddr; 2448 inc.inc_laddr = ip->ip_src; 2449 syncache_unreach(&inc, icmp_tcp_seq); 2450 } 2451 out: 2452 if (inp != NULL) 2453 INP_WUNLOCK(inp); 2454 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2455 } 2456 #endif /* INET */ 2457 2458 #ifdef INET6 2459 void 2460 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2461 { 2462 struct in6_addr *dst; 2463 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2464 struct ip6_hdr *ip6; 2465 struct mbuf *m; 2466 struct inpcb *inp; 2467 struct tcpcb *tp; 2468 struct icmp6_hdr *icmp6; 2469 struct ip6ctlparam *ip6cp = NULL; 2470 const struct sockaddr_in6 *sa6_src = NULL; 2471 struct in_conninfo inc; 2472 struct epoch_tracker et; 2473 struct tcp_ports { 2474 uint16_t th_sport; 2475 uint16_t th_dport; 2476 } t_ports; 2477 tcp_seq icmp_tcp_seq; 2478 unsigned int mtu; 2479 unsigned int off; 2480 2481 if (sa->sa_family != AF_INET6 || 2482 sa->sa_len != sizeof(struct sockaddr_in6)) 2483 return; 2484 2485 /* if the parameter is from icmp6, decode it. */ 2486 if (d != NULL) { 2487 ip6cp = (struct ip6ctlparam *)d; 2488 icmp6 = ip6cp->ip6c_icmp6; 2489 m = ip6cp->ip6c_m; 2490 ip6 = ip6cp->ip6c_ip6; 2491 off = ip6cp->ip6c_off; 2492 sa6_src = ip6cp->ip6c_src; 2493 dst = ip6cp->ip6c_finaldst; 2494 } else { 2495 m = NULL; 2496 ip6 = NULL; 2497 off = 0; /* fool gcc */ 2498 sa6_src = &sa6_any; 2499 dst = NULL; 2500 } 2501 2502 if (cmd == PRC_MSGSIZE) 2503 notify = tcp_mtudisc_notify; 2504 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2505 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2506 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2507 notify = tcp_drop_syn_sent; 2508 2509 /* 2510 * Hostdead is ugly because it goes linearly through all PCBs. 2511 * XXX: We never get this from ICMP, otherwise it makes an 2512 * excellent DoS attack on machines with many connections. 2513 */ 2514 else if (cmd == PRC_HOSTDEAD) 2515 ip6 = NULL; 2516 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2517 return; 2518 2519 if (ip6 == NULL) { 2520 in6_pcbnotify(&V_tcbinfo, sa, 0, 2521 (const struct sockaddr *)sa6_src, 2522 0, cmd, NULL, notify); 2523 return; 2524 } 2525 2526 /* Check if we can safely get the ports from the tcp hdr */ 2527 if (m == NULL || 2528 (m->m_pkthdr.len < 2529 (int32_t) (off + sizeof(struct tcp_ports)))) { 2530 return; 2531 } 2532 bzero(&t_ports, sizeof(struct tcp_ports)); 2533 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2534 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2535 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2536 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2537 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2538 /* signal EHOSTDOWN, as it flushes the cached route */ 2539 inp = (*notify)(inp, EHOSTDOWN); 2540 goto out; 2541 } 2542 off += sizeof(struct tcp_ports); 2543 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2544 goto out; 2545 } 2546 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2547 if (inp != NULL) { 2548 if (!(inp->inp_flags & INP_TIMEWAIT) && 2549 !(inp->inp_flags & INP_DROPPED) && 2550 !(inp->inp_socket == NULL)) { 2551 tp = intotcpcb(inp); 2552 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2553 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2554 if (cmd == PRC_MSGSIZE) { 2555 /* 2556 * MTU discovery: 2557 * If we got a needfrag set the MTU 2558 * in the route to the suggested new 2559 * value (if given) and then notify. 2560 */ 2561 mtu = ntohl(icmp6->icmp6_mtu); 2562 /* 2563 * If no alternative MTU was 2564 * proposed, or the proposed 2565 * MTU was too small, set to 2566 * the min. 2567 */ 2568 if (mtu < IPV6_MMTU) 2569 mtu = IPV6_MMTU - 8; 2570 bzero(&inc, sizeof(inc)); 2571 inc.inc_fibnum = M_GETFIB(m); 2572 inc.inc_flags |= INC_ISIPV6; 2573 inc.inc6_faddr = *dst; 2574 if (in6_setscope(&inc.inc6_faddr, 2575 m->m_pkthdr.rcvif, NULL)) 2576 goto out; 2577 /* 2578 * Only process the offered MTU if it 2579 * is smaller than the current one. 2580 */ 2581 if (mtu < tp->t_maxseg + 2582 sizeof (struct tcphdr) + 2583 sizeof (struct ip6_hdr)) { 2584 tcp_hc_updatemtu(&inc, mtu); 2585 tcp_mtudisc(inp, mtu); 2586 ICMP6STAT_INC(icp6s_pmtuchg); 2587 } 2588 } else 2589 inp = (*notify)(inp, 2590 inet6ctlerrmap[cmd]); 2591 } 2592 } 2593 } else { 2594 bzero(&inc, sizeof(inc)); 2595 inc.inc_fibnum = M_GETFIB(m); 2596 inc.inc_flags |= INC_ISIPV6; 2597 inc.inc_fport = t_ports.th_dport; 2598 inc.inc_lport = t_ports.th_sport; 2599 inc.inc6_faddr = *dst; 2600 inc.inc6_laddr = ip6->ip6_src; 2601 syncache_unreach(&inc, icmp_tcp_seq); 2602 } 2603 out: 2604 if (inp != NULL) 2605 INP_WUNLOCK(inp); 2606 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2607 } 2608 #endif /* INET6 */ 2609 2610 static uint32_t 2611 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2612 { 2613 MD5_CTX ctx; 2614 uint32_t hash[4]; 2615 2616 MD5Init(&ctx); 2617 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2618 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2619 switch (inc->inc_flags & INC_ISIPV6) { 2620 #ifdef INET 2621 case 0: 2622 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2623 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2624 break; 2625 #endif 2626 #ifdef INET6 2627 case INC_ISIPV6: 2628 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2629 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2630 break; 2631 #endif 2632 } 2633 MD5Update(&ctx, key, len); 2634 MD5Final((unsigned char *)hash, &ctx); 2635 2636 return (hash[0]); 2637 } 2638 2639 uint32_t 2640 tcp_new_ts_offset(struct in_conninfo *inc) 2641 { 2642 struct in_conninfo inc_store, *local_inc; 2643 2644 if (!V_tcp_ts_offset_per_conn) { 2645 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 2646 inc_store.inc_lport = 0; 2647 inc_store.inc_fport = 0; 2648 local_inc = &inc_store; 2649 } else { 2650 local_inc = inc; 2651 } 2652 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 2653 sizeof(V_ts_offset_secret))); 2654 } 2655 2656 /* 2657 * Following is where TCP initial sequence number generation occurs. 2658 * 2659 * There are two places where we must use initial sequence numbers: 2660 * 1. In SYN-ACK packets. 2661 * 2. In SYN packets. 2662 * 2663 * All ISNs for SYN-ACK packets are generated by the syncache. See 2664 * tcp_syncache.c for details. 2665 * 2666 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2667 * depends on this property. In addition, these ISNs should be 2668 * unguessable so as to prevent connection hijacking. To satisfy 2669 * the requirements of this situation, the algorithm outlined in 2670 * RFC 1948 is used, with only small modifications. 2671 * 2672 * Implementation details: 2673 * 2674 * Time is based off the system timer, and is corrected so that it 2675 * increases by one megabyte per second. This allows for proper 2676 * recycling on high speed LANs while still leaving over an hour 2677 * before rollover. 2678 * 2679 * As reading the *exact* system time is too expensive to be done 2680 * whenever setting up a TCP connection, we increment the time 2681 * offset in two ways. First, a small random positive increment 2682 * is added to isn_offset for each connection that is set up. 2683 * Second, the function tcp_isn_tick fires once per clock tick 2684 * and increments isn_offset as necessary so that sequence numbers 2685 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2686 * random positive increments serve only to ensure that the same 2687 * exact sequence number is never sent out twice (as could otherwise 2688 * happen when a port is recycled in less than the system tick 2689 * interval.) 2690 * 2691 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2692 * between seeding of isn_secret. This is normally set to zero, 2693 * as reseeding should not be necessary. 2694 * 2695 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2696 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2697 * general, this means holding an exclusive (write) lock. 2698 */ 2699 2700 #define ISN_BYTES_PER_SECOND 1048576 2701 #define ISN_STATIC_INCREMENT 4096 2702 #define ISN_RANDOM_INCREMENT (4096 - 1) 2703 #define ISN_SECRET_LENGTH 32 2704 2705 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2706 VNET_DEFINE_STATIC(int, isn_last); 2707 VNET_DEFINE_STATIC(int, isn_last_reseed); 2708 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2709 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2710 2711 #define V_isn_secret VNET(isn_secret) 2712 #define V_isn_last VNET(isn_last) 2713 #define V_isn_last_reseed VNET(isn_last_reseed) 2714 #define V_isn_offset VNET(isn_offset) 2715 #define V_isn_offset_old VNET(isn_offset_old) 2716 2717 tcp_seq 2718 tcp_new_isn(struct in_conninfo *inc) 2719 { 2720 tcp_seq new_isn; 2721 u_int32_t projected_offset; 2722 2723 ISN_LOCK(); 2724 /* Seed if this is the first use, reseed if requested. */ 2725 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2726 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2727 < (u_int)ticks))) { 2728 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2729 V_isn_last_reseed = ticks; 2730 } 2731 2732 /* Compute the md5 hash and return the ISN. */ 2733 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2734 sizeof(V_isn_secret)); 2735 V_isn_offset += ISN_STATIC_INCREMENT + 2736 (arc4random() & ISN_RANDOM_INCREMENT); 2737 if (ticks != V_isn_last) { 2738 projected_offset = V_isn_offset_old + 2739 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2740 if (SEQ_GT(projected_offset, V_isn_offset)) 2741 V_isn_offset = projected_offset; 2742 V_isn_offset_old = V_isn_offset; 2743 V_isn_last = ticks; 2744 } 2745 new_isn += V_isn_offset; 2746 ISN_UNLOCK(); 2747 return (new_isn); 2748 } 2749 2750 /* 2751 * When a specific ICMP unreachable message is received and the 2752 * connection state is SYN-SENT, drop the connection. This behavior 2753 * is controlled by the icmp_may_rst sysctl. 2754 */ 2755 struct inpcb * 2756 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2757 { 2758 struct tcpcb *tp; 2759 2760 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2761 INP_WLOCK_ASSERT(inp); 2762 2763 if ((inp->inp_flags & INP_TIMEWAIT) || 2764 (inp->inp_flags & INP_DROPPED)) 2765 return (inp); 2766 2767 tp = intotcpcb(inp); 2768 if (tp->t_state != TCPS_SYN_SENT) 2769 return (inp); 2770 2771 if (IS_FASTOPEN(tp->t_flags)) 2772 tcp_fastopen_disable_path(tp); 2773 2774 tp = tcp_drop(tp, errno); 2775 if (tp != NULL) 2776 return (inp); 2777 else 2778 return (NULL); 2779 } 2780 2781 /* 2782 * When `need fragmentation' ICMP is received, update our idea of the MSS 2783 * based on the new value. Also nudge TCP to send something, since we 2784 * know the packet we just sent was dropped. 2785 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2786 */ 2787 static struct inpcb * 2788 tcp_mtudisc_notify(struct inpcb *inp, int error) 2789 { 2790 2791 tcp_mtudisc(inp, -1); 2792 return (inp); 2793 } 2794 2795 static void 2796 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2797 { 2798 struct tcpcb *tp; 2799 struct socket *so; 2800 2801 INP_WLOCK_ASSERT(inp); 2802 if ((inp->inp_flags & INP_TIMEWAIT) || 2803 (inp->inp_flags & INP_DROPPED)) 2804 return; 2805 2806 tp = intotcpcb(inp); 2807 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2808 2809 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2810 2811 so = inp->inp_socket; 2812 SOCKBUF_LOCK(&so->so_snd); 2813 /* If the mss is larger than the socket buffer, decrease the mss. */ 2814 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2815 tp->t_maxseg = so->so_snd.sb_hiwat; 2816 SOCKBUF_UNLOCK(&so->so_snd); 2817 2818 TCPSTAT_INC(tcps_mturesent); 2819 tp->t_rtttime = 0; 2820 tp->snd_nxt = tp->snd_una; 2821 tcp_free_sackholes(tp); 2822 tp->snd_recover = tp->snd_max; 2823 if (tp->t_flags & TF_SACK_PERMIT) 2824 EXIT_FASTRECOVERY(tp->t_flags); 2825 tp->t_fb->tfb_tcp_output(tp); 2826 } 2827 2828 #ifdef INET 2829 /* 2830 * Look-up the routing entry to the peer of this inpcb. If no route 2831 * is found and it cannot be allocated, then return 0. This routine 2832 * is called by TCP routines that access the rmx structure and by 2833 * tcp_mss_update to get the peer/interface MTU. 2834 */ 2835 uint32_t 2836 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2837 { 2838 struct nhop4_extended nh4; 2839 struct ifnet *ifp; 2840 uint32_t maxmtu = 0; 2841 2842 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2843 2844 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2845 2846 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2847 NHR_REF, 0, &nh4) != 0) 2848 return (0); 2849 2850 ifp = nh4.nh_ifp; 2851 maxmtu = nh4.nh_mtu; 2852 2853 /* Report additional interface capabilities. */ 2854 if (cap != NULL) { 2855 if (ifp->if_capenable & IFCAP_TSO4 && 2856 ifp->if_hwassist & CSUM_TSO) { 2857 cap->ifcap |= CSUM_TSO; 2858 cap->tsomax = ifp->if_hw_tsomax; 2859 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2860 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2861 } 2862 } 2863 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2864 } 2865 return (maxmtu); 2866 } 2867 #endif /* INET */ 2868 2869 #ifdef INET6 2870 uint32_t 2871 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2872 { 2873 struct nhop6_extended nh6; 2874 struct in6_addr dst6; 2875 uint32_t scopeid; 2876 struct ifnet *ifp; 2877 uint32_t maxmtu = 0; 2878 2879 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2880 2881 if (inc->inc_flags & INC_IPV6MINMTU) 2882 return (IPV6_MMTU); 2883 2884 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2885 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2886 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2887 0, &nh6) != 0) 2888 return (0); 2889 2890 ifp = nh6.nh_ifp; 2891 maxmtu = nh6.nh_mtu; 2892 2893 /* Report additional interface capabilities. */ 2894 if (cap != NULL) { 2895 if (ifp->if_capenable & IFCAP_TSO6 && 2896 ifp->if_hwassist & CSUM_TSO) { 2897 cap->ifcap |= CSUM_TSO; 2898 cap->tsomax = ifp->if_hw_tsomax; 2899 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2900 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2901 } 2902 } 2903 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2904 } 2905 2906 return (maxmtu); 2907 } 2908 #endif /* INET6 */ 2909 2910 /* 2911 * Calculate effective SMSS per RFC5681 definition for a given TCP 2912 * connection at its current state, taking into account SACK and etc. 2913 */ 2914 u_int 2915 tcp_maxseg(const struct tcpcb *tp) 2916 { 2917 u_int optlen; 2918 2919 if (tp->t_flags & TF_NOOPT) 2920 return (tp->t_maxseg); 2921 2922 /* 2923 * Here we have a simplified code from tcp_addoptions(), 2924 * without a proper loop, and having most of paddings hardcoded. 2925 * We might make mistakes with padding here in some edge cases, 2926 * but this is harmless, since result of tcp_maxseg() is used 2927 * only in cwnd and ssthresh estimations. 2928 */ 2929 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2930 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2931 if (tp->t_flags & TF_RCVD_TSTMP) 2932 optlen = TCPOLEN_TSTAMP_APPA; 2933 else 2934 optlen = 0; 2935 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2936 if (tp->t_flags & TF_SIGNATURE) 2937 optlen += PAD(TCPOLEN_SIGNATURE); 2938 #endif 2939 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2940 optlen += TCPOLEN_SACKHDR; 2941 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2942 optlen = PAD(optlen); 2943 } 2944 } else { 2945 if (tp->t_flags & TF_REQ_TSTMP) 2946 optlen = TCPOLEN_TSTAMP_APPA; 2947 else 2948 optlen = PAD(TCPOLEN_MAXSEG); 2949 if (tp->t_flags & TF_REQ_SCALE) 2950 optlen += PAD(TCPOLEN_WINDOW); 2951 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2952 if (tp->t_flags & TF_SIGNATURE) 2953 optlen += PAD(TCPOLEN_SIGNATURE); 2954 #endif 2955 if (tp->t_flags & TF_SACK_PERMIT) 2956 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2957 } 2958 #undef PAD 2959 optlen = min(optlen, TCP_MAXOLEN); 2960 return (tp->t_maxseg - optlen); 2961 } 2962 2963 static int 2964 sysctl_drop(SYSCTL_HANDLER_ARGS) 2965 { 2966 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2967 struct sockaddr_storage addrs[2]; 2968 struct inpcb *inp; 2969 struct tcpcb *tp; 2970 struct tcptw *tw; 2971 struct sockaddr_in *fin, *lin; 2972 struct epoch_tracker et; 2973 #ifdef INET6 2974 struct sockaddr_in6 *fin6, *lin6; 2975 #endif 2976 int error; 2977 2978 inp = NULL; 2979 fin = lin = NULL; 2980 #ifdef INET6 2981 fin6 = lin6 = NULL; 2982 #endif 2983 error = 0; 2984 2985 if (req->oldptr != NULL || req->oldlen != 0) 2986 return (EINVAL); 2987 if (req->newptr == NULL) 2988 return (EPERM); 2989 if (req->newlen < sizeof(addrs)) 2990 return (ENOMEM); 2991 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2992 if (error) 2993 return (error); 2994 2995 switch (addrs[0].ss_family) { 2996 #ifdef INET6 2997 case AF_INET6: 2998 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2999 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3000 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3001 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3002 return (EINVAL); 3003 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3004 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3005 return (EINVAL); 3006 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3007 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3008 fin = (struct sockaddr_in *)&addrs[0]; 3009 lin = (struct sockaddr_in *)&addrs[1]; 3010 break; 3011 } 3012 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3013 if (error) 3014 return (error); 3015 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3016 if (error) 3017 return (error); 3018 break; 3019 #endif 3020 #ifdef INET 3021 case AF_INET: 3022 fin = (struct sockaddr_in *)&addrs[0]; 3023 lin = (struct sockaddr_in *)&addrs[1]; 3024 if (fin->sin_len != sizeof(struct sockaddr_in) || 3025 lin->sin_len != sizeof(struct sockaddr_in)) 3026 return (EINVAL); 3027 break; 3028 #endif 3029 default: 3030 return (EINVAL); 3031 } 3032 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3033 switch (addrs[0].ss_family) { 3034 #ifdef INET6 3035 case AF_INET6: 3036 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3037 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3038 INPLOOKUP_WLOCKPCB, NULL); 3039 break; 3040 #endif 3041 #ifdef INET 3042 case AF_INET: 3043 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3044 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3045 break; 3046 #endif 3047 } 3048 if (inp != NULL) { 3049 if (inp->inp_flags & INP_TIMEWAIT) { 3050 /* 3051 * XXXRW: There currently exists a state where an 3052 * inpcb is present, but its timewait state has been 3053 * discarded. For now, don't allow dropping of this 3054 * type of inpcb. 3055 */ 3056 tw = intotw(inp); 3057 if (tw != NULL) 3058 tcp_twclose(tw, 0); 3059 else 3060 INP_WUNLOCK(inp); 3061 } else if (!(inp->inp_flags & INP_DROPPED) && 3062 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3063 tp = intotcpcb(inp); 3064 tp = tcp_drop(tp, ECONNABORTED); 3065 if (tp != NULL) 3066 INP_WUNLOCK(inp); 3067 } else 3068 INP_WUNLOCK(inp); 3069 } else 3070 error = ESRCH; 3071 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3072 return (error); 3073 } 3074 3075 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3076 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3077 0, sysctl_drop, "", "Drop TCP connection"); 3078 3079 /* 3080 * Generate a standardized TCP log line for use throughout the 3081 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3082 * allow use in the interrupt context. 3083 * 3084 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3085 * NB: The function may return NULL if memory allocation failed. 3086 * 3087 * Due to header inclusion and ordering limitations the struct ip 3088 * and ip6_hdr pointers have to be passed as void pointers. 3089 */ 3090 char * 3091 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3092 const void *ip6hdr) 3093 { 3094 3095 /* Is logging enabled? */ 3096 if (tcp_log_in_vain == 0) 3097 return (NULL); 3098 3099 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3100 } 3101 3102 char * 3103 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3104 const void *ip6hdr) 3105 { 3106 3107 /* Is logging enabled? */ 3108 if (tcp_log_debug == 0) 3109 return (NULL); 3110 3111 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3112 } 3113 3114 static char * 3115 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3116 const void *ip6hdr) 3117 { 3118 char *s, *sp; 3119 size_t size; 3120 struct ip *ip; 3121 #ifdef INET6 3122 const struct ip6_hdr *ip6; 3123 3124 ip6 = (const struct ip6_hdr *)ip6hdr; 3125 #endif /* INET6 */ 3126 ip = (struct ip *)ip4hdr; 3127 3128 /* 3129 * The log line looks like this: 3130 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3131 */ 3132 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3133 sizeof(PRINT_TH_FLAGS) + 1 + 3134 #ifdef INET6 3135 2 * INET6_ADDRSTRLEN; 3136 #else 3137 2 * INET_ADDRSTRLEN; 3138 #endif /* INET6 */ 3139 3140 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3141 if (s == NULL) 3142 return (NULL); 3143 3144 strcat(s, "TCP: ["); 3145 sp = s + strlen(s); 3146 3147 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3148 inet_ntoa_r(inc->inc_faddr, sp); 3149 sp = s + strlen(s); 3150 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3151 sp = s + strlen(s); 3152 inet_ntoa_r(inc->inc_laddr, sp); 3153 sp = s + strlen(s); 3154 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3155 #ifdef INET6 3156 } else if (inc) { 3157 ip6_sprintf(sp, &inc->inc6_faddr); 3158 sp = s + strlen(s); 3159 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3160 sp = s + strlen(s); 3161 ip6_sprintf(sp, &inc->inc6_laddr); 3162 sp = s + strlen(s); 3163 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3164 } else if (ip6 && th) { 3165 ip6_sprintf(sp, &ip6->ip6_src); 3166 sp = s + strlen(s); 3167 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3168 sp = s + strlen(s); 3169 ip6_sprintf(sp, &ip6->ip6_dst); 3170 sp = s + strlen(s); 3171 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3172 #endif /* INET6 */ 3173 #ifdef INET 3174 } else if (ip && th) { 3175 inet_ntoa_r(ip->ip_src, sp); 3176 sp = s + strlen(s); 3177 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3178 sp = s + strlen(s); 3179 inet_ntoa_r(ip->ip_dst, sp); 3180 sp = s + strlen(s); 3181 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3182 #endif /* INET */ 3183 } else { 3184 free(s, M_TCPLOG); 3185 return (NULL); 3186 } 3187 sp = s + strlen(s); 3188 if (th) 3189 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3190 if (*(s + size - 1) != '\0') 3191 panic("%s: string too long", __func__); 3192 return (s); 3193 } 3194 3195 /* 3196 * A subroutine which makes it easy to track TCP state changes with DTrace. 3197 * This function shouldn't be called for t_state initializations that don't 3198 * correspond to actual TCP state transitions. 3199 */ 3200 void 3201 tcp_state_change(struct tcpcb *tp, int newstate) 3202 { 3203 #if defined(KDTRACE_HOOKS) 3204 int pstate = tp->t_state; 3205 #endif 3206 3207 TCPSTATES_DEC(tp->t_state); 3208 TCPSTATES_INC(newstate); 3209 tp->t_state = newstate; 3210 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3211 } 3212 3213 /* 3214 * Create an external-format (``xtcpcb'') structure using the information in 3215 * the kernel-format tcpcb structure pointed to by tp. This is done to 3216 * reduce the spew of irrelevant information over this interface, to isolate 3217 * user code from changes in the kernel structure, and potentially to provide 3218 * information-hiding if we decide that some of this information should be 3219 * hidden from users. 3220 */ 3221 void 3222 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3223 { 3224 struct tcpcb *tp = intotcpcb(inp); 3225 sbintime_t now; 3226 3227 bzero(xt, sizeof(*xt)); 3228 if (inp->inp_flags & INP_TIMEWAIT) { 3229 xt->t_state = TCPS_TIME_WAIT; 3230 } else { 3231 xt->t_state = tp->t_state; 3232 xt->t_logstate = tp->t_logstate; 3233 xt->t_flags = tp->t_flags; 3234 xt->t_sndzerowin = tp->t_sndzerowin; 3235 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3236 xt->t_rcvoopack = tp->t_rcvoopack; 3237 3238 now = getsbinuptime(); 3239 #define COPYTIMER(ttt) do { \ 3240 if (callout_active(&tp->t_timers->ttt)) \ 3241 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3242 SBT_1MS; \ 3243 else \ 3244 xt->ttt = 0; \ 3245 } while (0) 3246 COPYTIMER(tt_delack); 3247 COPYTIMER(tt_rexmt); 3248 COPYTIMER(tt_persist); 3249 COPYTIMER(tt_keep); 3250 COPYTIMER(tt_2msl); 3251 #undef COPYTIMER 3252 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3253 3254 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3255 TCP_FUNCTION_NAME_LEN_MAX); 3256 #ifdef TCP_BLACKBOX 3257 (void)tcp_log_get_id(tp, xt->xt_logid); 3258 #endif 3259 } 3260 3261 xt->xt_len = sizeof(struct xtcpcb); 3262 in_pcbtoxinpcb(inp, &xt->xt_inp); 3263 if (inp->inp_socket == NULL) 3264 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3265 } 3266