1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_tcpdebug.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/callout.h> 45 #include <sys/eventhandler.h> 46 #ifdef TCP_HHOOK 47 #include <sys/hhook.h> 48 #endif 49 #include <sys/kernel.h> 50 #ifdef TCP_HHOOK 51 #include <sys/khelp.h> 52 #endif 53 #include <sys/sysctl.h> 54 #include <sys/jail.h> 55 #include <sys/malloc.h> 56 #include <sys/refcount.h> 57 #include <sys/mbuf.h> 58 #ifdef INET6 59 #include <sys/domain.h> 60 #endif 61 #include <sys/priv.h> 62 #include <sys/proc.h> 63 #include <sys/sdt.h> 64 #include <sys/socket.h> 65 #include <sys/socketvar.h> 66 #include <sys/protosw.h> 67 #include <sys/random.h> 68 69 #include <vm/uma.h> 70 71 #include <net/route.h> 72 #include <net/if.h> 73 #include <net/if_var.h> 74 #include <net/vnet.h> 75 76 #include <netinet/in.h> 77 #include <netinet/in_fib.h> 78 #include <netinet/in_kdtrace.h> 79 #include <netinet/in_pcb.h> 80 #include <netinet/in_systm.h> 81 #include <netinet/in_var.h> 82 #include <netinet/ip.h> 83 #include <netinet/ip_icmp.h> 84 #include <netinet/ip_var.h> 85 #ifdef INET6 86 #include <netinet/icmp6.h> 87 #include <netinet/ip6.h> 88 #include <netinet6/in6_fib.h> 89 #include <netinet6/in6_pcb.h> 90 #include <netinet6/ip6_var.h> 91 #include <netinet6/scope6_var.h> 92 #include <netinet6/nd6.h> 93 #endif 94 95 #include <netinet/tcp.h> 96 #include <netinet/tcp_fsm.h> 97 #include <netinet/tcp_seq.h> 98 #include <netinet/tcp_timer.h> 99 #include <netinet/tcp_var.h> 100 #include <netinet/tcp_log_buf.h> 101 #include <netinet/tcp_syncache.h> 102 #include <netinet/tcp_hpts.h> 103 #include <netinet/cc/cc.h> 104 #ifdef INET6 105 #include <netinet6/tcp6_var.h> 106 #endif 107 #include <netinet/tcpip.h> 108 #include <netinet/tcp_fastopen.h> 109 #ifdef TCPPCAP 110 #include <netinet/tcp_pcap.h> 111 #endif 112 #ifdef TCPDEBUG 113 #include <netinet/tcp_debug.h> 114 #endif 115 #ifdef INET6 116 #include <netinet6/ip6protosw.h> 117 #endif 118 #ifdef TCP_OFFLOAD 119 #include <netinet/tcp_offload.h> 120 #endif 121 122 #include <netipsec/ipsec_support.h> 123 124 #include <machine/in_cksum.h> 125 #include <sys/md5.h> 126 127 #include <security/mac/mac_framework.h> 128 129 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 130 #ifdef INET6 131 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 132 #endif 133 134 struct rwlock tcp_function_lock; 135 136 static int 137 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 138 { 139 int error, new; 140 141 new = V_tcp_mssdflt; 142 error = sysctl_handle_int(oidp, &new, 0, req); 143 if (error == 0 && req->newptr) { 144 if (new < TCP_MINMSS) 145 error = EINVAL; 146 else 147 V_tcp_mssdflt = new; 148 } 149 return (error); 150 } 151 152 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 153 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 154 &sysctl_net_inet_tcp_mss_check, "I", 155 "Default TCP Maximum Segment Size"); 156 157 #ifdef INET6 158 static int 159 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 160 { 161 int error, new; 162 163 new = V_tcp_v6mssdflt; 164 error = sysctl_handle_int(oidp, &new, 0, req); 165 if (error == 0 && req->newptr) { 166 if (new < TCP_MINMSS) 167 error = EINVAL; 168 else 169 V_tcp_v6mssdflt = new; 170 } 171 return (error); 172 } 173 174 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 175 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 176 &sysctl_net_inet_tcp_mss_v6_check, "I", 177 "Default TCP Maximum Segment Size for IPv6"); 178 #endif /* INET6 */ 179 180 /* 181 * Minimum MSS we accept and use. This prevents DoS attacks where 182 * we are forced to a ridiculous low MSS like 20 and send hundreds 183 * of packets instead of one. The effect scales with the available 184 * bandwidth and quickly saturates the CPU and network interface 185 * with packet generation and sending. Set to zero to disable MINMSS 186 * checking. This setting prevents us from sending too small packets. 187 */ 188 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 190 &VNET_NAME(tcp_minmss), 0, 191 "Minimum TCP Maximum Segment Size"); 192 193 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 194 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 195 &VNET_NAME(tcp_do_rfc1323), 0, 196 "Enable rfc1323 (high performance TCP) extensions"); 197 198 static int tcp_log_debug = 0; 199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 200 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 201 202 static int tcp_tcbhashsize; 203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 204 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 205 206 static int do_tcpdrain = 1; 207 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 208 "Enable tcp_drain routine for extra help when low on mbufs"); 209 210 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 211 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 212 213 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 214 #define V_icmp_may_rst VNET(icmp_may_rst) 215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 216 &VNET_NAME(icmp_may_rst), 0, 217 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 218 219 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 220 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 221 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 222 &VNET_NAME(tcp_isn_reseed_interval), 0, 223 "Seconds between reseeding of ISN secret"); 224 225 static int tcp_soreceive_stream; 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 227 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 228 229 VNET_DEFINE(uma_zone_t, sack_hole_zone); 230 #define V_sack_hole_zone VNET(sack_hole_zone) 231 232 #ifdef TCP_HHOOK 233 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 234 #endif 235 236 #define TS_OFFSET_SECRET_LENGTH 32 237 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 238 #define V_ts_offset_secret VNET(ts_offset_secret) 239 240 static int tcp_default_fb_init(struct tcpcb *tp); 241 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 242 static int tcp_default_handoff_ok(struct tcpcb *tp); 243 static struct inpcb *tcp_notify(struct inpcb *, int); 244 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 245 static void tcp_mtudisc(struct inpcb *, int); 246 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 247 void *ip4hdr, const void *ip6hdr); 248 249 250 static struct tcp_function_block tcp_def_funcblk = { 251 .tfb_tcp_block_name = "freebsd", 252 .tfb_tcp_output = tcp_output, 253 .tfb_tcp_do_segment = tcp_do_segment, 254 .tfb_tcp_ctloutput = tcp_default_ctloutput, 255 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 256 .tfb_tcp_fb_init = tcp_default_fb_init, 257 .tfb_tcp_fb_fini = tcp_default_fb_fini, 258 }; 259 260 int t_functions_inited = 0; 261 static int tcp_fb_cnt = 0; 262 struct tcp_funchead t_functions; 263 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 264 265 static void 266 init_tcp_functions(void) 267 { 268 if (t_functions_inited == 0) { 269 TAILQ_INIT(&t_functions); 270 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 271 t_functions_inited = 1; 272 } 273 } 274 275 static struct tcp_function_block * 276 find_tcp_functions_locked(struct tcp_function_set *fs) 277 { 278 struct tcp_function *f; 279 struct tcp_function_block *blk=NULL; 280 281 TAILQ_FOREACH(f, &t_functions, tf_next) { 282 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 283 blk = f->tf_fb; 284 break; 285 } 286 } 287 return(blk); 288 } 289 290 static struct tcp_function_block * 291 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 292 { 293 struct tcp_function_block *rblk=NULL; 294 struct tcp_function *f; 295 296 TAILQ_FOREACH(f, &t_functions, tf_next) { 297 if (f->tf_fb == blk) { 298 rblk = blk; 299 if (s) { 300 *s = f; 301 } 302 break; 303 } 304 } 305 return (rblk); 306 } 307 308 struct tcp_function_block * 309 find_and_ref_tcp_functions(struct tcp_function_set *fs) 310 { 311 struct tcp_function_block *blk; 312 313 rw_rlock(&tcp_function_lock); 314 blk = find_tcp_functions_locked(fs); 315 if (blk) 316 refcount_acquire(&blk->tfb_refcnt); 317 rw_runlock(&tcp_function_lock); 318 return(blk); 319 } 320 321 struct tcp_function_block * 322 find_and_ref_tcp_fb(struct tcp_function_block *blk) 323 { 324 struct tcp_function_block *rblk; 325 326 rw_rlock(&tcp_function_lock); 327 rblk = find_tcp_fb_locked(blk, NULL); 328 if (rblk) 329 refcount_acquire(&rblk->tfb_refcnt); 330 rw_runlock(&tcp_function_lock); 331 return(rblk); 332 } 333 334 static struct tcp_function_block * 335 find_and_ref_tcp_default_fb(void) 336 { 337 struct tcp_function_block *rblk; 338 339 rw_rlock(&tcp_function_lock); 340 rblk = tcp_func_set_ptr; 341 refcount_acquire(&rblk->tfb_refcnt); 342 rw_runlock(&tcp_function_lock); 343 return (rblk); 344 } 345 346 void 347 tcp_switch_back_to_default(struct tcpcb *tp) 348 { 349 struct tcp_function_block *tfb; 350 351 KASSERT(tp->t_fb != &tcp_def_funcblk, 352 ("%s: called by the built-in default stack", __func__)); 353 354 /* 355 * Release the old stack. This function will either find a new one 356 * or panic. 357 */ 358 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 359 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 360 refcount_release(&tp->t_fb->tfb_refcnt); 361 362 /* 363 * Now, we'll find a new function block to use. 364 * Start by trying the current user-selected 365 * default, unless this stack is the user-selected 366 * default. 367 */ 368 tfb = find_and_ref_tcp_default_fb(); 369 if (tfb == tp->t_fb) { 370 refcount_release(&tfb->tfb_refcnt); 371 tfb = NULL; 372 } 373 /* Does the stack accept this connection? */ 374 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 375 (*tfb->tfb_tcp_handoff_ok)(tp)) { 376 refcount_release(&tfb->tfb_refcnt); 377 tfb = NULL; 378 } 379 /* Try to use that stack. */ 380 if (tfb != NULL) { 381 /* Initialize the new stack. If it succeeds, we are done. */ 382 tp->t_fb = tfb; 383 if (tp->t_fb->tfb_tcp_fb_init == NULL || 384 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 385 return; 386 387 /* 388 * Initialization failed. Release the reference count on 389 * the stack. 390 */ 391 refcount_release(&tfb->tfb_refcnt); 392 } 393 394 /* 395 * If that wasn't feasible, use the built-in default 396 * stack which is not allowed to reject anyone. 397 */ 398 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 399 if (tfb == NULL) { 400 /* there always should be a default */ 401 panic("Can't refer to tcp_def_funcblk"); 402 } 403 if (tfb->tfb_tcp_handoff_ok != NULL) { 404 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 405 /* The default stack cannot say no */ 406 panic("Default stack rejects a new session?"); 407 } 408 } 409 tp->t_fb = tfb; 410 if (tp->t_fb->tfb_tcp_fb_init != NULL && 411 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 412 /* The default stack cannot fail */ 413 panic("Default stack initialization failed"); 414 } 415 } 416 417 static int 418 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 419 { 420 int error=ENOENT; 421 struct tcp_function_set fs; 422 struct tcp_function_block *blk; 423 424 memset(&fs, 0, sizeof(fs)); 425 rw_rlock(&tcp_function_lock); 426 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 427 if (blk) { 428 /* Found him */ 429 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 430 fs.pcbcnt = blk->tfb_refcnt; 431 } 432 rw_runlock(&tcp_function_lock); 433 error = sysctl_handle_string(oidp, fs.function_set_name, 434 sizeof(fs.function_set_name), req); 435 436 /* Check for error or no change */ 437 if (error != 0 || req->newptr == NULL) 438 return(error); 439 440 rw_wlock(&tcp_function_lock); 441 blk = find_tcp_functions_locked(&fs); 442 if ((blk == NULL) || 443 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 444 error = ENOENT; 445 goto done; 446 } 447 tcp_func_set_ptr = blk; 448 done: 449 rw_wunlock(&tcp_function_lock); 450 return (error); 451 } 452 453 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 454 CTLTYPE_STRING | CTLFLAG_RW, 455 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 456 "Set/get the default TCP functions"); 457 458 static int 459 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 460 { 461 int error, cnt, linesz; 462 struct tcp_function *f; 463 char *buffer, *cp; 464 size_t bufsz, outsz; 465 bool alias; 466 467 cnt = 0; 468 rw_rlock(&tcp_function_lock); 469 TAILQ_FOREACH(f, &t_functions, tf_next) { 470 cnt++; 471 } 472 rw_runlock(&tcp_function_lock); 473 474 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 475 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 476 477 error = 0; 478 cp = buffer; 479 480 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 481 "Alias", "PCB count"); 482 cp += linesz; 483 bufsz -= linesz; 484 outsz = linesz; 485 486 rw_rlock(&tcp_function_lock); 487 TAILQ_FOREACH(f, &t_functions, tf_next) { 488 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 489 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 490 f->tf_fb->tfb_tcp_block_name, 491 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 492 alias ? f->tf_name : "-", 493 f->tf_fb->tfb_refcnt); 494 if (linesz >= bufsz) { 495 error = EOVERFLOW; 496 break; 497 } 498 cp += linesz; 499 bufsz -= linesz; 500 outsz += linesz; 501 } 502 rw_runlock(&tcp_function_lock); 503 if (error == 0) 504 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 505 free(buffer, M_TEMP); 506 return (error); 507 } 508 509 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 510 CTLTYPE_STRING|CTLFLAG_RD, 511 NULL, 0, sysctl_net_inet_list_available, "A", 512 "list available TCP Function sets"); 513 514 /* 515 * Exports one (struct tcp_function_info) for each alias/name. 516 */ 517 static int 518 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 519 { 520 int cnt, error; 521 struct tcp_function *f; 522 struct tcp_function_info tfi; 523 524 /* 525 * We don't allow writes. 526 */ 527 if (req->newptr != NULL) 528 return (EINVAL); 529 530 /* 531 * Wire the old buffer so we can directly copy the functions to 532 * user space without dropping the lock. 533 */ 534 if (req->oldptr != NULL) { 535 error = sysctl_wire_old_buffer(req, 0); 536 if (error) 537 return (error); 538 } 539 540 /* 541 * Walk the list and copy out matching entries. If INVARIANTS 542 * is compiled in, also walk the list to verify the length of 543 * the list matches what we have recorded. 544 */ 545 rw_rlock(&tcp_function_lock); 546 547 cnt = 0; 548 #ifndef INVARIANTS 549 if (req->oldptr == NULL) { 550 cnt = tcp_fb_cnt; 551 goto skip_loop; 552 } 553 #endif 554 TAILQ_FOREACH(f, &t_functions, tf_next) { 555 #ifdef INVARIANTS 556 cnt++; 557 #endif 558 if (req->oldptr != NULL) { 559 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 560 tfi.tfi_id = f->tf_fb->tfb_id; 561 (void)strncpy(tfi.tfi_alias, f->tf_name, 562 TCP_FUNCTION_NAME_LEN_MAX); 563 tfi.tfi_alias[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 564 (void)strncpy(tfi.tfi_name, 565 f->tf_fb->tfb_tcp_block_name, 566 TCP_FUNCTION_NAME_LEN_MAX); 567 tfi.tfi_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 568 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 569 /* 570 * Don't stop on error, as that is the 571 * mechanism we use to accumulate length 572 * information if the buffer was too short. 573 */ 574 } 575 } 576 KASSERT(cnt == tcp_fb_cnt, 577 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 578 #ifndef INVARIANTS 579 skip_loop: 580 #endif 581 rw_runlock(&tcp_function_lock); 582 if (req->oldptr == NULL) 583 error = SYSCTL_OUT(req, NULL, 584 (cnt + 1) * sizeof(struct tcp_function_info)); 585 586 return (error); 587 } 588 589 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 590 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 591 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 592 "List TCP function block name-to-ID mappings"); 593 594 /* 595 * tfb_tcp_handoff_ok() function for the default stack. 596 * Note that we'll basically try to take all comers. 597 */ 598 static int 599 tcp_default_handoff_ok(struct tcpcb *tp) 600 { 601 602 return (0); 603 } 604 605 /* 606 * tfb_tcp_fb_init() function for the default stack. 607 * 608 * This handles making sure we have appropriate timers set if you are 609 * transitioning a socket that has some amount of setup done. 610 * 611 * The init() fuction from the default can *never* return non-zero i.e. 612 * it is required to always succeed since it is the stack of last resort! 613 */ 614 static int 615 tcp_default_fb_init(struct tcpcb *tp) 616 { 617 618 struct socket *so; 619 620 INP_WLOCK_ASSERT(tp->t_inpcb); 621 622 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 623 ("%s: connection %p in unexpected state %d", __func__, tp, 624 tp->t_state)); 625 626 /* 627 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 628 * know what to do for unexpected states (which includes TIME_WAIT). 629 */ 630 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 631 return (0); 632 633 /* 634 * Make sure some kind of transmission timer is set if there is 635 * outstanding data. 636 */ 637 so = tp->t_inpcb->inp_socket; 638 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 639 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 640 tcp_timer_active(tp, TT_PERSIST))) { 641 /* 642 * If the session has established and it looks like it should 643 * be in the persist state, set the persist timer. Otherwise, 644 * set the retransmit timer. 645 */ 646 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 647 (int32_t)(tp->snd_nxt - tp->snd_una) < 648 (int32_t)sbavail(&so->so_snd)) 649 tcp_setpersist(tp); 650 else 651 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 652 } 653 654 /* All non-embryonic sessions get a keepalive timer. */ 655 if (!tcp_timer_active(tp, TT_KEEP)) 656 tcp_timer_activate(tp, TT_KEEP, 657 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 658 TP_KEEPINIT(tp)); 659 660 return (0); 661 } 662 663 /* 664 * tfb_tcp_fb_fini() function for the default stack. 665 * 666 * This changes state as necessary (or prudent) to prepare for another stack 667 * to assume responsibility for the connection. 668 */ 669 static void 670 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 671 { 672 673 INP_WLOCK_ASSERT(tp->t_inpcb); 674 return; 675 } 676 677 /* 678 * Target size of TCP PCB hash tables. Must be a power of two. 679 * 680 * Note that this can be overridden by the kernel environment 681 * variable net.inet.tcp.tcbhashsize 682 */ 683 #ifndef TCBHASHSIZE 684 #define TCBHASHSIZE 0 685 #endif 686 687 /* 688 * XXX 689 * Callouts should be moved into struct tcp directly. They are currently 690 * separate because the tcpcb structure is exported to userland for sysctl 691 * parsing purposes, which do not know about callouts. 692 */ 693 struct tcpcb_mem { 694 struct tcpcb tcb; 695 struct tcp_timer tt; 696 struct cc_var ccv; 697 #ifdef TCP_HHOOK 698 struct osd osd; 699 #endif 700 }; 701 702 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 703 #define V_tcpcb_zone VNET(tcpcb_zone) 704 705 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 706 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 707 708 static struct mtx isn_mtx; 709 710 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 711 #define ISN_LOCK() mtx_lock(&isn_mtx) 712 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 713 714 /* 715 * TCP initialization. 716 */ 717 static void 718 tcp_zone_change(void *tag) 719 { 720 721 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 722 uma_zone_set_max(V_tcpcb_zone, maxsockets); 723 tcp_tw_zone_change(); 724 } 725 726 static int 727 tcp_inpcb_init(void *mem, int size, int flags) 728 { 729 struct inpcb *inp = mem; 730 731 INP_LOCK_INIT(inp, "inp", "tcpinp"); 732 return (0); 733 } 734 735 /* 736 * Take a value and get the next power of 2 that doesn't overflow. 737 * Used to size the tcp_inpcb hash buckets. 738 */ 739 static int 740 maketcp_hashsize(int size) 741 { 742 int hashsize; 743 744 /* 745 * auto tune. 746 * get the next power of 2 higher than maxsockets. 747 */ 748 hashsize = 1 << fls(size); 749 /* catch overflow, and just go one power of 2 smaller */ 750 if (hashsize < size) { 751 hashsize = 1 << (fls(size) - 1); 752 } 753 return (hashsize); 754 } 755 756 static volatile int next_tcp_stack_id = 1; 757 758 /* 759 * Register a TCP function block with the name provided in the names 760 * array. (Note that this function does NOT automatically register 761 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 762 * explicitly include blk->tfb_tcp_block_name in the list of names if 763 * you wish to register the stack with that name.) 764 * 765 * Either all name registrations will succeed or all will fail. If 766 * a name registration fails, the function will update the num_names 767 * argument to point to the array index of the name that encountered 768 * the failure. 769 * 770 * Returns 0 on success, or an error code on failure. 771 */ 772 int 773 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 774 const char *names[], int *num_names) 775 { 776 struct tcp_function *n; 777 struct tcp_function_set fs; 778 int error, i; 779 780 KASSERT(names != NULL && *num_names > 0, 781 ("%s: Called with 0-length name list", __func__)); 782 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 783 784 if (t_functions_inited == 0) { 785 init_tcp_functions(); 786 } 787 if ((blk->tfb_tcp_output == NULL) || 788 (blk->tfb_tcp_do_segment == NULL) || 789 (blk->tfb_tcp_ctloutput == NULL) || 790 (strlen(blk->tfb_tcp_block_name) == 0)) { 791 /* 792 * These functions are required and you 793 * need a name. 794 */ 795 *num_names = 0; 796 return (EINVAL); 797 } 798 if (blk->tfb_tcp_timer_stop_all || 799 blk->tfb_tcp_timer_activate || 800 blk->tfb_tcp_timer_active || 801 blk->tfb_tcp_timer_stop) { 802 /* 803 * If you define one timer function you 804 * must have them all. 805 */ 806 if ((blk->tfb_tcp_timer_stop_all == NULL) || 807 (blk->tfb_tcp_timer_activate == NULL) || 808 (blk->tfb_tcp_timer_active == NULL) || 809 (blk->tfb_tcp_timer_stop == NULL)) { 810 *num_names = 0; 811 return (EINVAL); 812 } 813 } 814 815 refcount_init(&blk->tfb_refcnt, 0); 816 blk->tfb_flags = 0; 817 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 818 for (i = 0; i < *num_names; i++) { 819 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 820 if (n == NULL) { 821 error = ENOMEM; 822 goto cleanup; 823 } 824 n->tf_fb = blk; 825 826 (void)strncpy(fs.function_set_name, names[i], 827 TCP_FUNCTION_NAME_LEN_MAX); 828 fs.function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 829 rw_wlock(&tcp_function_lock); 830 if (find_tcp_functions_locked(&fs) != NULL) { 831 /* Duplicate name space not allowed */ 832 rw_wunlock(&tcp_function_lock); 833 free(n, M_TCPFUNCTIONS); 834 error = EALREADY; 835 goto cleanup; 836 } 837 (void)strncpy(n->tf_name, names[i], TCP_FUNCTION_NAME_LEN_MAX); 838 n->tf_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 839 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 840 tcp_fb_cnt++; 841 rw_wunlock(&tcp_function_lock); 842 } 843 return(0); 844 845 cleanup: 846 /* 847 * Deregister the names we just added. Because registration failed 848 * for names[i], we don't need to deregister that name. 849 */ 850 *num_names = i; 851 rw_wlock(&tcp_function_lock); 852 while (--i >= 0) { 853 TAILQ_FOREACH(n, &t_functions, tf_next) { 854 if (!strncmp(n->tf_name, names[i], 855 TCP_FUNCTION_NAME_LEN_MAX)) { 856 TAILQ_REMOVE(&t_functions, n, tf_next); 857 tcp_fb_cnt--; 858 n->tf_fb = NULL; 859 free(n, M_TCPFUNCTIONS); 860 break; 861 } 862 } 863 } 864 rw_wunlock(&tcp_function_lock); 865 return (error); 866 } 867 868 /* 869 * Register a TCP function block using the name provided in the name 870 * argument. 871 * 872 * Returns 0 on success, or an error code on failure. 873 */ 874 int 875 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 876 int wait) 877 { 878 const char *name_list[1]; 879 int num_names, rv; 880 881 num_names = 1; 882 if (name != NULL) 883 name_list[0] = name; 884 else 885 name_list[0] = blk->tfb_tcp_block_name; 886 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 887 return (rv); 888 } 889 890 /* 891 * Register a TCP function block using the name defined in 892 * blk->tfb_tcp_block_name. 893 * 894 * Returns 0 on success, or an error code on failure. 895 */ 896 int 897 register_tcp_functions(struct tcp_function_block *blk, int wait) 898 { 899 900 return (register_tcp_functions_as_name(blk, NULL, wait)); 901 } 902 903 /* 904 * Deregister all names associated with a function block. This 905 * functionally removes the function block from use within the system. 906 * 907 * When called with a true quiesce argument, mark the function block 908 * as being removed so no more stacks will use it and determine 909 * whether the removal would succeed. 910 * 911 * When called with a false quiesce argument, actually attempt the 912 * removal. 913 * 914 * When called with a force argument, attempt to switch all TCBs to 915 * use the default stack instead of returning EBUSY. 916 * 917 * Returns 0 on success (or if the removal would succeed, or an error 918 * code on failure. 919 */ 920 int 921 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 922 bool force) 923 { 924 struct tcp_function *f; 925 926 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 927 /* You can't un-register the default */ 928 return (EPERM); 929 } 930 rw_wlock(&tcp_function_lock); 931 if (blk == tcp_func_set_ptr) { 932 /* You can't free the current default */ 933 rw_wunlock(&tcp_function_lock); 934 return (EBUSY); 935 } 936 /* Mark the block so no more stacks can use it. */ 937 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 938 /* 939 * If TCBs are still attached to the stack, attempt to switch them 940 * to the default stack. 941 */ 942 if (force && blk->tfb_refcnt) { 943 struct inpcb *inp; 944 struct tcpcb *tp; 945 VNET_ITERATOR_DECL(vnet_iter); 946 947 rw_wunlock(&tcp_function_lock); 948 949 VNET_LIST_RLOCK(); 950 VNET_FOREACH(vnet_iter) { 951 CURVNET_SET(vnet_iter); 952 INP_INFO_WLOCK(&V_tcbinfo); 953 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 954 INP_WLOCK(inp); 955 if (inp->inp_flags & INP_TIMEWAIT) { 956 INP_WUNLOCK(inp); 957 continue; 958 } 959 tp = intotcpcb(inp); 960 if (tp == NULL || tp->t_fb != blk) { 961 INP_WUNLOCK(inp); 962 continue; 963 } 964 tcp_switch_back_to_default(tp); 965 INP_WUNLOCK(inp); 966 } 967 INP_INFO_WUNLOCK(&V_tcbinfo); 968 CURVNET_RESTORE(); 969 } 970 VNET_LIST_RUNLOCK(); 971 972 rw_wlock(&tcp_function_lock); 973 } 974 if (blk->tfb_refcnt) { 975 /* TCBs still attached. */ 976 rw_wunlock(&tcp_function_lock); 977 return (EBUSY); 978 } 979 if (quiesce) { 980 /* Skip removal. */ 981 rw_wunlock(&tcp_function_lock); 982 return (0); 983 } 984 /* Remove any function names that map to this function block. */ 985 while (find_tcp_fb_locked(blk, &f) != NULL) { 986 TAILQ_REMOVE(&t_functions, f, tf_next); 987 tcp_fb_cnt--; 988 f->tf_fb = NULL; 989 free(f, M_TCPFUNCTIONS); 990 } 991 rw_wunlock(&tcp_function_lock); 992 return (0); 993 } 994 995 void 996 tcp_init(void) 997 { 998 const char *tcbhash_tuneable; 999 int hashsize; 1000 1001 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1002 1003 #ifdef TCP_HHOOK 1004 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1005 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1006 printf("%s: WARNING: unable to register helper hook\n", __func__); 1007 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1008 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1009 printf("%s: WARNING: unable to register helper hook\n", __func__); 1010 #endif 1011 hashsize = TCBHASHSIZE; 1012 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1013 if (hashsize == 0) { 1014 /* 1015 * Auto tune the hash size based on maxsockets. 1016 * A perfect hash would have a 1:1 mapping 1017 * (hashsize = maxsockets) however it's been 1018 * suggested that O(2) average is better. 1019 */ 1020 hashsize = maketcp_hashsize(maxsockets / 4); 1021 /* 1022 * Our historical default is 512, 1023 * do not autotune lower than this. 1024 */ 1025 if (hashsize < 512) 1026 hashsize = 512; 1027 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1028 printf("%s: %s auto tuned to %d\n", __func__, 1029 tcbhash_tuneable, hashsize); 1030 } 1031 /* 1032 * We require a hashsize to be a power of two. 1033 * Previously if it was not a power of two we would just reset it 1034 * back to 512, which could be a nasty surprise if you did not notice 1035 * the error message. 1036 * Instead what we do is clip it to the closest power of two lower 1037 * than the specified hash value. 1038 */ 1039 if (!powerof2(hashsize)) { 1040 int oldhashsize = hashsize; 1041 1042 hashsize = maketcp_hashsize(hashsize); 1043 /* prevent absurdly low value */ 1044 if (hashsize < 16) 1045 hashsize = 16; 1046 printf("%s: WARNING: TCB hash size not a power of 2, " 1047 "clipped from %d to %d.\n", __func__, oldhashsize, 1048 hashsize); 1049 } 1050 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1051 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1052 1053 /* 1054 * These have to be type stable for the benefit of the timers. 1055 */ 1056 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1057 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1058 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1059 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1060 1061 tcp_tw_init(); 1062 syncache_init(); 1063 tcp_hc_init(); 1064 1065 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1066 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1067 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1068 1069 tcp_fastopen_init(); 1070 1071 /* Skip initialization of globals for non-default instances. */ 1072 if (!IS_DEFAULT_VNET(curvnet)) 1073 return; 1074 1075 tcp_reass_global_init(); 1076 1077 /* XXX virtualize those bellow? */ 1078 tcp_delacktime = TCPTV_DELACK; 1079 tcp_keepinit = TCPTV_KEEP_INIT; 1080 tcp_keepidle = TCPTV_KEEP_IDLE; 1081 tcp_keepintvl = TCPTV_KEEPINTVL; 1082 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1083 tcp_msl = TCPTV_MSL; 1084 tcp_rexmit_min = TCPTV_MIN; 1085 if (tcp_rexmit_min < 1) 1086 tcp_rexmit_min = 1; 1087 tcp_persmin = TCPTV_PERSMIN; 1088 tcp_persmax = TCPTV_PERSMAX; 1089 tcp_rexmit_slop = TCPTV_CPU_VAR; 1090 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1091 tcp_tcbhashsize = hashsize; 1092 /* Setup the tcp function block list */ 1093 init_tcp_functions(); 1094 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1095 #ifdef TCP_BLACKBOX 1096 /* Initialize the TCP logging data. */ 1097 tcp_log_init(); 1098 #endif 1099 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1100 1101 if (tcp_soreceive_stream) { 1102 #ifdef INET 1103 tcp_usrreqs.pru_soreceive = soreceive_stream; 1104 #endif 1105 #ifdef INET6 1106 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1107 #endif /* INET6 */ 1108 } 1109 1110 #ifdef INET6 1111 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1112 #else /* INET6 */ 1113 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1114 #endif /* INET6 */ 1115 if (max_protohdr < TCP_MINPROTOHDR) 1116 max_protohdr = TCP_MINPROTOHDR; 1117 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1118 panic("tcp_init"); 1119 #undef TCP_MINPROTOHDR 1120 1121 ISN_LOCK_INIT(); 1122 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1123 SHUTDOWN_PRI_DEFAULT); 1124 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1125 EVENTHANDLER_PRI_ANY); 1126 #ifdef TCPPCAP 1127 tcp_pcap_init(); 1128 #endif 1129 } 1130 1131 #ifdef VIMAGE 1132 static void 1133 tcp_destroy(void *unused __unused) 1134 { 1135 int n; 1136 #ifdef TCP_HHOOK 1137 int error; 1138 #endif 1139 1140 /* 1141 * All our processes are gone, all our sockets should be cleaned 1142 * up, which means, we should be past the tcp_discardcb() calls. 1143 * Sleep to let all tcpcb timers really disappear and cleanup. 1144 */ 1145 for (;;) { 1146 INP_LIST_RLOCK(&V_tcbinfo); 1147 n = V_tcbinfo.ipi_count; 1148 INP_LIST_RUNLOCK(&V_tcbinfo); 1149 if (n == 0) 1150 break; 1151 pause("tcpdes", hz / 10); 1152 } 1153 tcp_hc_destroy(); 1154 syncache_destroy(); 1155 tcp_tw_destroy(); 1156 in_pcbinfo_destroy(&V_tcbinfo); 1157 /* tcp_discardcb() clears the sack_holes up. */ 1158 uma_zdestroy(V_sack_hole_zone); 1159 uma_zdestroy(V_tcpcb_zone); 1160 1161 /* 1162 * Cannot free the zone until all tcpcbs are released as we attach 1163 * the allocations to them. 1164 */ 1165 tcp_fastopen_destroy(); 1166 1167 #ifdef TCP_HHOOK 1168 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1169 if (error != 0) { 1170 printf("%s: WARNING: unable to deregister helper hook " 1171 "type=%d, id=%d: error %d returned\n", __func__, 1172 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1173 } 1174 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1175 if (error != 0) { 1176 printf("%s: WARNING: unable to deregister helper hook " 1177 "type=%d, id=%d: error %d returned\n", __func__, 1178 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1179 } 1180 #endif 1181 } 1182 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1183 #endif 1184 1185 void 1186 tcp_fini(void *xtp) 1187 { 1188 1189 } 1190 1191 /* 1192 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1193 * tcp_template used to store this data in mbufs, but we now recopy it out 1194 * of the tcpcb each time to conserve mbufs. 1195 */ 1196 void 1197 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1198 { 1199 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1200 1201 INP_WLOCK_ASSERT(inp); 1202 1203 #ifdef INET6 1204 if ((inp->inp_vflag & INP_IPV6) != 0) { 1205 struct ip6_hdr *ip6; 1206 1207 ip6 = (struct ip6_hdr *)ip_ptr; 1208 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1209 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1210 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1211 (IPV6_VERSION & IPV6_VERSION_MASK); 1212 ip6->ip6_nxt = IPPROTO_TCP; 1213 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1214 ip6->ip6_src = inp->in6p_laddr; 1215 ip6->ip6_dst = inp->in6p_faddr; 1216 } 1217 #endif /* INET6 */ 1218 #if defined(INET6) && defined(INET) 1219 else 1220 #endif 1221 #ifdef INET 1222 { 1223 struct ip *ip; 1224 1225 ip = (struct ip *)ip_ptr; 1226 ip->ip_v = IPVERSION; 1227 ip->ip_hl = 5; 1228 ip->ip_tos = inp->inp_ip_tos; 1229 ip->ip_len = 0; 1230 ip->ip_id = 0; 1231 ip->ip_off = 0; 1232 ip->ip_ttl = inp->inp_ip_ttl; 1233 ip->ip_sum = 0; 1234 ip->ip_p = IPPROTO_TCP; 1235 ip->ip_src = inp->inp_laddr; 1236 ip->ip_dst = inp->inp_faddr; 1237 } 1238 #endif /* INET */ 1239 th->th_sport = inp->inp_lport; 1240 th->th_dport = inp->inp_fport; 1241 th->th_seq = 0; 1242 th->th_ack = 0; 1243 th->th_x2 = 0; 1244 th->th_off = 5; 1245 th->th_flags = 0; 1246 th->th_win = 0; 1247 th->th_urp = 0; 1248 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1249 } 1250 1251 /* 1252 * Create template to be used to send tcp packets on a connection. 1253 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1254 * use for this function is in keepalives, which use tcp_respond. 1255 */ 1256 struct tcptemp * 1257 tcpip_maketemplate(struct inpcb *inp) 1258 { 1259 struct tcptemp *t; 1260 1261 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1262 if (t == NULL) 1263 return (NULL); 1264 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1265 return (t); 1266 } 1267 1268 /* 1269 * Send a single message to the TCP at address specified by 1270 * the given TCP/IP header. If m == NULL, then we make a copy 1271 * of the tcpiphdr at th and send directly to the addressed host. 1272 * This is used to force keep alive messages out using the TCP 1273 * template for a connection. If flags are given then we send 1274 * a message back to the TCP which originated the segment th, 1275 * and discard the mbuf containing it and any other attached mbufs. 1276 * 1277 * In any case the ack and sequence number of the transmitted 1278 * segment are as specified by the parameters. 1279 * 1280 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1281 */ 1282 void 1283 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1284 tcp_seq ack, tcp_seq seq, int flags) 1285 { 1286 struct tcpopt to; 1287 struct inpcb *inp; 1288 struct ip *ip; 1289 struct mbuf *optm; 1290 struct tcphdr *nth; 1291 u_char *optp; 1292 #ifdef INET6 1293 struct ip6_hdr *ip6; 1294 int isipv6; 1295 #endif /* INET6 */ 1296 int optlen, tlen, win; 1297 bool incl_opts; 1298 1299 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1300 1301 #ifdef INET6 1302 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1303 ip6 = ipgen; 1304 #endif /* INET6 */ 1305 ip = ipgen; 1306 1307 if (tp != NULL) { 1308 inp = tp->t_inpcb; 1309 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1310 INP_WLOCK_ASSERT(inp); 1311 } else 1312 inp = NULL; 1313 1314 incl_opts = false; 1315 win = 0; 1316 if (tp != NULL) { 1317 if (!(flags & TH_RST)) { 1318 win = sbspace(&inp->inp_socket->so_rcv); 1319 if (win > TCP_MAXWIN << tp->rcv_scale) 1320 win = TCP_MAXWIN << tp->rcv_scale; 1321 } 1322 if ((tp->t_flags & TF_NOOPT) == 0) 1323 incl_opts = true; 1324 } 1325 if (m == NULL) { 1326 m = m_gethdr(M_NOWAIT, MT_DATA); 1327 if (m == NULL) 1328 return; 1329 m->m_data += max_linkhdr; 1330 #ifdef INET6 1331 if (isipv6) { 1332 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1333 sizeof(struct ip6_hdr)); 1334 ip6 = mtod(m, struct ip6_hdr *); 1335 nth = (struct tcphdr *)(ip6 + 1); 1336 } else 1337 #endif /* INET6 */ 1338 { 1339 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1340 ip = mtod(m, struct ip *); 1341 nth = (struct tcphdr *)(ip + 1); 1342 } 1343 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1344 flags = TH_ACK; 1345 } else if (!M_WRITABLE(m)) { 1346 struct mbuf *n; 1347 1348 /* Can't reuse 'm', allocate a new mbuf. */ 1349 n = m_gethdr(M_NOWAIT, MT_DATA); 1350 if (n == NULL) { 1351 m_freem(m); 1352 return; 1353 } 1354 1355 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1356 m_freem(m); 1357 m_freem(n); 1358 return; 1359 } 1360 1361 n->m_data += max_linkhdr; 1362 /* m_len is set later */ 1363 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1364 #ifdef INET6 1365 if (isipv6) { 1366 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1367 sizeof(struct ip6_hdr)); 1368 ip6 = mtod(n, struct ip6_hdr *); 1369 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1370 nth = (struct tcphdr *)(ip6 + 1); 1371 } else 1372 #endif /* INET6 */ 1373 { 1374 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1375 ip = mtod(n, struct ip *); 1376 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1377 nth = (struct tcphdr *)(ip + 1); 1378 } 1379 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1380 xchg(nth->th_dport, nth->th_sport, uint16_t); 1381 th = nth; 1382 m_freem(m); 1383 m = n; 1384 } else { 1385 /* 1386 * reuse the mbuf. 1387 * XXX MRT We inherit the FIB, which is lucky. 1388 */ 1389 m_freem(m->m_next); 1390 m->m_next = NULL; 1391 m->m_data = (caddr_t)ipgen; 1392 /* m_len is set later */ 1393 #ifdef INET6 1394 if (isipv6) { 1395 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1396 nth = (struct tcphdr *)(ip6 + 1); 1397 } else 1398 #endif /* INET6 */ 1399 { 1400 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1401 nth = (struct tcphdr *)(ip + 1); 1402 } 1403 if (th != nth) { 1404 /* 1405 * this is usually a case when an extension header 1406 * exists between the IPv6 header and the 1407 * TCP header. 1408 */ 1409 nth->th_sport = th->th_sport; 1410 nth->th_dport = th->th_dport; 1411 } 1412 xchg(nth->th_dport, nth->th_sport, uint16_t); 1413 #undef xchg 1414 } 1415 tlen = 0; 1416 #ifdef INET6 1417 if (isipv6) 1418 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1419 #endif 1420 #if defined(INET) && defined(INET6) 1421 else 1422 #endif 1423 #ifdef INET 1424 tlen = sizeof (struct tcpiphdr); 1425 #endif 1426 #ifdef INVARIANTS 1427 m->m_len = 0; 1428 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1429 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1430 m, tlen, (long)M_TRAILINGSPACE(m))); 1431 #endif 1432 m->m_len = tlen; 1433 to.to_flags = 0; 1434 if (incl_opts) { 1435 /* Make sure we have room. */ 1436 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1437 m->m_next = m_get(M_NOWAIT, MT_DATA); 1438 if (m->m_next) { 1439 optp = mtod(m->m_next, u_char *); 1440 optm = m->m_next; 1441 } else 1442 incl_opts = false; 1443 } else { 1444 optp = (u_char *) (nth + 1); 1445 optm = m; 1446 } 1447 } 1448 if (incl_opts) { 1449 /* Timestamps. */ 1450 if (tp->t_flags & TF_RCVD_TSTMP) { 1451 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1452 to.to_tsecr = tp->ts_recent; 1453 to.to_flags |= TOF_TS; 1454 } 1455 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1456 /* TCP-MD5 (RFC2385). */ 1457 if (tp->t_flags & TF_SIGNATURE) 1458 to.to_flags |= TOF_SIGNATURE; 1459 #endif 1460 /* Add the options. */ 1461 tlen += optlen = tcp_addoptions(&to, optp); 1462 1463 /* Update m_len in the correct mbuf. */ 1464 optm->m_len += optlen; 1465 } else 1466 optlen = 0; 1467 #ifdef INET6 1468 if (isipv6) { 1469 ip6->ip6_flow = 0; 1470 ip6->ip6_vfc = IPV6_VERSION; 1471 ip6->ip6_nxt = IPPROTO_TCP; 1472 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1473 } 1474 #endif 1475 #if defined(INET) && defined(INET6) 1476 else 1477 #endif 1478 #ifdef INET 1479 { 1480 ip->ip_len = htons(tlen); 1481 ip->ip_ttl = V_ip_defttl; 1482 if (V_path_mtu_discovery) 1483 ip->ip_off |= htons(IP_DF); 1484 } 1485 #endif 1486 m->m_pkthdr.len = tlen; 1487 m->m_pkthdr.rcvif = NULL; 1488 #ifdef MAC 1489 if (inp != NULL) { 1490 /* 1491 * Packet is associated with a socket, so allow the 1492 * label of the response to reflect the socket label. 1493 */ 1494 INP_WLOCK_ASSERT(inp); 1495 mac_inpcb_create_mbuf(inp, m); 1496 } else { 1497 /* 1498 * Packet is not associated with a socket, so possibly 1499 * update the label in place. 1500 */ 1501 mac_netinet_tcp_reply(m); 1502 } 1503 #endif 1504 nth->th_seq = htonl(seq); 1505 nth->th_ack = htonl(ack); 1506 nth->th_x2 = 0; 1507 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1508 nth->th_flags = flags; 1509 if (tp != NULL) 1510 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1511 else 1512 nth->th_win = htons((u_short)win); 1513 nth->th_urp = 0; 1514 1515 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1516 if (to.to_flags & TOF_SIGNATURE) { 1517 if (!TCPMD5_ENABLED() || 1518 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1519 m_freem(m); 1520 return; 1521 } 1522 } 1523 #endif 1524 1525 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1526 #ifdef INET6 1527 if (isipv6) { 1528 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1529 nth->th_sum = in6_cksum_pseudo(ip6, 1530 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1531 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1532 NULL, NULL); 1533 } 1534 #endif /* INET6 */ 1535 #if defined(INET6) && defined(INET) 1536 else 1537 #endif 1538 #ifdef INET 1539 { 1540 m->m_pkthdr.csum_flags = CSUM_TCP; 1541 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1542 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1543 } 1544 #endif /* INET */ 1545 #ifdef TCPDEBUG 1546 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1547 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1548 #endif 1549 TCP_PROBE3(debug__output, tp, th, m); 1550 if (flags & TH_RST) 1551 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1552 1553 #ifdef INET6 1554 if (isipv6) { 1555 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1556 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1557 } 1558 #endif /* INET6 */ 1559 #if defined(INET) && defined(INET6) 1560 else 1561 #endif 1562 #ifdef INET 1563 { 1564 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1565 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1566 } 1567 #endif 1568 } 1569 1570 /* 1571 * Create a new TCP control block, making an 1572 * empty reassembly queue and hooking it to the argument 1573 * protocol control block. The `inp' parameter must have 1574 * come from the zone allocator set up in tcp_init(). 1575 */ 1576 struct tcpcb * 1577 tcp_newtcpcb(struct inpcb *inp) 1578 { 1579 struct tcpcb_mem *tm; 1580 struct tcpcb *tp; 1581 #ifdef INET6 1582 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1583 #endif /* INET6 */ 1584 1585 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1586 if (tm == NULL) 1587 return (NULL); 1588 tp = &tm->tcb; 1589 1590 /* Initialise cc_var struct for this tcpcb. */ 1591 tp->ccv = &tm->ccv; 1592 tp->ccv->type = IPPROTO_TCP; 1593 tp->ccv->ccvc.tcp = tp; 1594 rw_rlock(&tcp_function_lock); 1595 tp->t_fb = tcp_func_set_ptr; 1596 refcount_acquire(&tp->t_fb->tfb_refcnt); 1597 rw_runlock(&tcp_function_lock); 1598 /* 1599 * Use the current system default CC algorithm. 1600 */ 1601 CC_LIST_RLOCK(); 1602 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1603 CC_ALGO(tp) = CC_DEFAULT(); 1604 CC_LIST_RUNLOCK(); 1605 1606 if (CC_ALGO(tp)->cb_init != NULL) 1607 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1608 if (tp->t_fb->tfb_tcp_fb_fini) 1609 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1610 refcount_release(&tp->t_fb->tfb_refcnt); 1611 uma_zfree(V_tcpcb_zone, tm); 1612 return (NULL); 1613 } 1614 1615 #ifdef TCP_HHOOK 1616 tp->osd = &tm->osd; 1617 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1618 if (tp->t_fb->tfb_tcp_fb_fini) 1619 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1620 refcount_release(&tp->t_fb->tfb_refcnt); 1621 uma_zfree(V_tcpcb_zone, tm); 1622 return (NULL); 1623 } 1624 #endif 1625 1626 #ifdef VIMAGE 1627 tp->t_vnet = inp->inp_vnet; 1628 #endif 1629 tp->t_timers = &tm->tt; 1630 TAILQ_INIT(&tp->t_segq); 1631 tp->t_maxseg = 1632 #ifdef INET6 1633 isipv6 ? V_tcp_v6mssdflt : 1634 #endif /* INET6 */ 1635 V_tcp_mssdflt; 1636 1637 /* Set up our timeouts. */ 1638 callout_init(&tp->t_timers->tt_rexmt, 1); 1639 callout_init(&tp->t_timers->tt_persist, 1); 1640 callout_init(&tp->t_timers->tt_keep, 1); 1641 callout_init(&tp->t_timers->tt_2msl, 1); 1642 callout_init(&tp->t_timers->tt_delack, 1); 1643 1644 if (V_tcp_do_rfc1323) 1645 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1646 if (V_tcp_do_sack) 1647 tp->t_flags |= TF_SACK_PERMIT; 1648 TAILQ_INIT(&tp->snd_holes); 1649 /* 1650 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1651 * is called. 1652 */ 1653 in_pcbref(inp); /* Reference for tcpcb */ 1654 tp->t_inpcb = inp; 1655 1656 /* 1657 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1658 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1659 * reasonable initial retransmit time. 1660 */ 1661 tp->t_srtt = TCPTV_SRTTBASE; 1662 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1663 tp->t_rttmin = tcp_rexmit_min; 1664 tp->t_rxtcur = TCPTV_RTOBASE; 1665 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1666 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1667 tp->t_rcvtime = ticks; 1668 /* 1669 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1670 * because the socket may be bound to an IPv6 wildcard address, 1671 * which may match an IPv4-mapped IPv6 address. 1672 */ 1673 inp->inp_ip_ttl = V_ip_defttl; 1674 inp->inp_ppcb = tp; 1675 #ifdef TCPPCAP 1676 /* 1677 * Init the TCP PCAP queues. 1678 */ 1679 tcp_pcap_tcpcb_init(tp); 1680 #endif 1681 #ifdef TCP_BLACKBOX 1682 /* Initialize the per-TCPCB log data. */ 1683 tcp_log_tcpcbinit(tp); 1684 #endif 1685 if (tp->t_fb->tfb_tcp_fb_init) { 1686 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1687 } 1688 return (tp); /* XXX */ 1689 } 1690 1691 /* 1692 * Switch the congestion control algorithm back to NewReno for any active 1693 * control blocks using an algorithm which is about to go away. 1694 * This ensures the CC framework can allow the unload to proceed without leaving 1695 * any dangling pointers which would trigger a panic. 1696 * Returning non-zero would inform the CC framework that something went wrong 1697 * and it would be unsafe to allow the unload to proceed. However, there is no 1698 * way for this to occur with this implementation so we always return zero. 1699 */ 1700 int 1701 tcp_ccalgounload(struct cc_algo *unload_algo) 1702 { 1703 struct cc_algo *tmpalgo; 1704 struct inpcb *inp; 1705 struct tcpcb *tp; 1706 VNET_ITERATOR_DECL(vnet_iter); 1707 1708 /* 1709 * Check all active control blocks across all network stacks and change 1710 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1711 * requires cleanup code to be run, call it. 1712 */ 1713 VNET_LIST_RLOCK(); 1714 VNET_FOREACH(vnet_iter) { 1715 CURVNET_SET(vnet_iter); 1716 INP_INFO_WLOCK(&V_tcbinfo); 1717 /* 1718 * New connections already part way through being initialised 1719 * with the CC algo we're removing will not race with this code 1720 * because the INP_INFO_WLOCK is held during initialisation. We 1721 * therefore don't enter the loop below until the connection 1722 * list has stabilised. 1723 */ 1724 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1725 INP_WLOCK(inp); 1726 /* Important to skip tcptw structs. */ 1727 if (!(inp->inp_flags & INP_TIMEWAIT) && 1728 (tp = intotcpcb(inp)) != NULL) { 1729 /* 1730 * By holding INP_WLOCK here, we are assured 1731 * that the connection is not currently 1732 * executing inside the CC module's functions 1733 * i.e. it is safe to make the switch back to 1734 * NewReno. 1735 */ 1736 if (CC_ALGO(tp) == unload_algo) { 1737 tmpalgo = CC_ALGO(tp); 1738 if (tmpalgo->cb_destroy != NULL) 1739 tmpalgo->cb_destroy(tp->ccv); 1740 CC_DATA(tp) = NULL; 1741 /* 1742 * NewReno may allocate memory on 1743 * demand for certain stateful 1744 * configuration as needed, but is 1745 * coded to never fail on memory 1746 * allocation failure so it is a safe 1747 * fallback. 1748 */ 1749 CC_ALGO(tp) = &newreno_cc_algo; 1750 } 1751 } 1752 INP_WUNLOCK(inp); 1753 } 1754 INP_INFO_WUNLOCK(&V_tcbinfo); 1755 CURVNET_RESTORE(); 1756 } 1757 VNET_LIST_RUNLOCK(); 1758 1759 return (0); 1760 } 1761 1762 /* 1763 * Drop a TCP connection, reporting 1764 * the specified error. If connection is synchronized, 1765 * then send a RST to peer. 1766 */ 1767 struct tcpcb * 1768 tcp_drop(struct tcpcb *tp, int errno) 1769 { 1770 struct socket *so = tp->t_inpcb->inp_socket; 1771 1772 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1773 INP_WLOCK_ASSERT(tp->t_inpcb); 1774 1775 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1776 tcp_state_change(tp, TCPS_CLOSED); 1777 (void) tp->t_fb->tfb_tcp_output(tp); 1778 TCPSTAT_INC(tcps_drops); 1779 } else 1780 TCPSTAT_INC(tcps_conndrops); 1781 if (errno == ETIMEDOUT && tp->t_softerror) 1782 errno = tp->t_softerror; 1783 so->so_error = errno; 1784 return (tcp_close(tp)); 1785 } 1786 1787 void 1788 tcp_discardcb(struct tcpcb *tp) 1789 { 1790 struct inpcb *inp = tp->t_inpcb; 1791 struct socket *so = inp->inp_socket; 1792 #ifdef INET6 1793 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1794 #endif /* INET6 */ 1795 int released __unused; 1796 1797 INP_WLOCK_ASSERT(inp); 1798 1799 /* 1800 * Make sure that all of our timers are stopped before we delete the 1801 * PCB. 1802 * 1803 * If stopping a timer fails, we schedule a discard function in same 1804 * callout, and the last discard function called will take care of 1805 * deleting the tcpcb. 1806 */ 1807 tp->t_timers->tt_draincnt = 0; 1808 tcp_timer_stop(tp, TT_REXMT); 1809 tcp_timer_stop(tp, TT_PERSIST); 1810 tcp_timer_stop(tp, TT_KEEP); 1811 tcp_timer_stop(tp, TT_2MSL); 1812 tcp_timer_stop(tp, TT_DELACK); 1813 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1814 /* 1815 * Call the stop-all function of the methods, 1816 * this function should call the tcp_timer_stop() 1817 * method with each of the function specific timeouts. 1818 * That stop will be called via the tfb_tcp_timer_stop() 1819 * which should use the async drain function of the 1820 * callout system (see tcp_var.h). 1821 */ 1822 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1823 } 1824 1825 /* 1826 * If we got enough samples through the srtt filter, 1827 * save the rtt and rttvar in the routing entry. 1828 * 'Enough' is arbitrarily defined as 4 rtt samples. 1829 * 4 samples is enough for the srtt filter to converge 1830 * to within enough % of the correct value; fewer samples 1831 * and we could save a bogus rtt. The danger is not high 1832 * as tcp quickly recovers from everything. 1833 * XXX: Works very well but needs some more statistics! 1834 */ 1835 if (tp->t_rttupdated >= 4) { 1836 struct hc_metrics_lite metrics; 1837 uint32_t ssthresh; 1838 1839 bzero(&metrics, sizeof(metrics)); 1840 /* 1841 * Update the ssthresh always when the conditions below 1842 * are satisfied. This gives us better new start value 1843 * for the congestion avoidance for new connections. 1844 * ssthresh is only set if packet loss occurred on a session. 1845 * 1846 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1847 * being torn down. Ideally this code would not use 'so'. 1848 */ 1849 ssthresh = tp->snd_ssthresh; 1850 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1851 /* 1852 * convert the limit from user data bytes to 1853 * packets then to packet data bytes. 1854 */ 1855 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1856 if (ssthresh < 2) 1857 ssthresh = 2; 1858 ssthresh *= (tp->t_maxseg + 1859 #ifdef INET6 1860 (isipv6 ? sizeof (struct ip6_hdr) + 1861 sizeof (struct tcphdr) : 1862 #endif 1863 sizeof (struct tcpiphdr) 1864 #ifdef INET6 1865 ) 1866 #endif 1867 ); 1868 } else 1869 ssthresh = 0; 1870 metrics.rmx_ssthresh = ssthresh; 1871 1872 metrics.rmx_rtt = tp->t_srtt; 1873 metrics.rmx_rttvar = tp->t_rttvar; 1874 metrics.rmx_cwnd = tp->snd_cwnd; 1875 metrics.rmx_sendpipe = 0; 1876 metrics.rmx_recvpipe = 0; 1877 1878 tcp_hc_update(&inp->inp_inc, &metrics); 1879 } 1880 1881 /* free the reassembly queue, if any */ 1882 tcp_reass_flush(tp); 1883 1884 #ifdef TCP_OFFLOAD 1885 /* Disconnect offload device, if any. */ 1886 if (tp->t_flags & TF_TOE) 1887 tcp_offload_detach(tp); 1888 #endif 1889 1890 tcp_free_sackholes(tp); 1891 1892 #ifdef TCPPCAP 1893 /* Free the TCP PCAP queues. */ 1894 tcp_pcap_drain(&(tp->t_inpkts)); 1895 tcp_pcap_drain(&(tp->t_outpkts)); 1896 #endif 1897 1898 /* Allow the CC algorithm to clean up after itself. */ 1899 if (CC_ALGO(tp)->cb_destroy != NULL) 1900 CC_ALGO(tp)->cb_destroy(tp->ccv); 1901 CC_DATA(tp) = NULL; 1902 1903 #ifdef TCP_HHOOK 1904 khelp_destroy_osd(tp->osd); 1905 #endif 1906 1907 CC_ALGO(tp) = NULL; 1908 inp->inp_ppcb = NULL; 1909 if (tp->t_timers->tt_draincnt == 0) { 1910 /* We own the last reference on tcpcb, let's free it. */ 1911 #ifdef TCP_BLACKBOX 1912 tcp_log_tcpcbfini(tp); 1913 #endif 1914 TCPSTATES_DEC(tp->t_state); 1915 if (tp->t_fb->tfb_tcp_fb_fini) 1916 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1917 refcount_release(&tp->t_fb->tfb_refcnt); 1918 tp->t_inpcb = NULL; 1919 uma_zfree(V_tcpcb_zone, tp); 1920 released = in_pcbrele_wlocked(inp); 1921 KASSERT(!released, ("%s: inp %p should not have been released " 1922 "here", __func__, inp)); 1923 } 1924 } 1925 1926 void 1927 tcp_timer_discard(void *ptp) 1928 { 1929 struct inpcb *inp; 1930 struct tcpcb *tp; 1931 struct epoch_tracker et; 1932 1933 tp = (struct tcpcb *)ptp; 1934 CURVNET_SET(tp->t_vnet); 1935 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 1936 inp = tp->t_inpcb; 1937 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1938 __func__, tp)); 1939 INP_WLOCK(inp); 1940 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1941 ("%s: tcpcb has to be stopped here", __func__)); 1942 tp->t_timers->tt_draincnt--; 1943 if (tp->t_timers->tt_draincnt == 0) { 1944 /* We own the last reference on this tcpcb, let's free it. */ 1945 #ifdef TCP_BLACKBOX 1946 tcp_log_tcpcbfini(tp); 1947 #endif 1948 TCPSTATES_DEC(tp->t_state); 1949 if (tp->t_fb->tfb_tcp_fb_fini) 1950 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1951 refcount_release(&tp->t_fb->tfb_refcnt); 1952 tp->t_inpcb = NULL; 1953 uma_zfree(V_tcpcb_zone, tp); 1954 if (in_pcbrele_wlocked(inp)) { 1955 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1956 CURVNET_RESTORE(); 1957 return; 1958 } 1959 } 1960 INP_WUNLOCK(inp); 1961 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1962 CURVNET_RESTORE(); 1963 } 1964 1965 /* 1966 * Attempt to close a TCP control block, marking it as dropped, and freeing 1967 * the socket if we hold the only reference. 1968 */ 1969 struct tcpcb * 1970 tcp_close(struct tcpcb *tp) 1971 { 1972 struct inpcb *inp = tp->t_inpcb; 1973 struct socket *so; 1974 1975 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1976 INP_WLOCK_ASSERT(inp); 1977 1978 #ifdef TCP_OFFLOAD 1979 if (tp->t_state == TCPS_LISTEN) 1980 tcp_offload_listen_stop(tp); 1981 #endif 1982 /* 1983 * This releases the TFO pending counter resource for TFO listen 1984 * sockets as well as passively-created TFO sockets that transition 1985 * from SYN_RECEIVED to CLOSED. 1986 */ 1987 if (tp->t_tfo_pending) { 1988 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1989 tp->t_tfo_pending = NULL; 1990 } 1991 in_pcbdrop(inp); 1992 TCPSTAT_INC(tcps_closed); 1993 if (tp->t_state != TCPS_CLOSED) 1994 tcp_state_change(tp, TCPS_CLOSED); 1995 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1996 so = inp->inp_socket; 1997 soisdisconnected(so); 1998 if (inp->inp_flags & INP_SOCKREF) { 1999 KASSERT(so->so_state & SS_PROTOREF, 2000 ("tcp_close: !SS_PROTOREF")); 2001 inp->inp_flags &= ~INP_SOCKREF; 2002 INP_WUNLOCK(inp); 2003 SOCK_LOCK(so); 2004 so->so_state &= ~SS_PROTOREF; 2005 sofree(so); 2006 return (NULL); 2007 } 2008 return (tp); 2009 } 2010 2011 void 2012 tcp_drain(void) 2013 { 2014 VNET_ITERATOR_DECL(vnet_iter); 2015 2016 if (!do_tcpdrain) 2017 return; 2018 2019 VNET_LIST_RLOCK_NOSLEEP(); 2020 VNET_FOREACH(vnet_iter) { 2021 CURVNET_SET(vnet_iter); 2022 struct inpcb *inpb; 2023 struct tcpcb *tcpb; 2024 2025 /* 2026 * Walk the tcpbs, if existing, and flush the reassembly queue, 2027 * if there is one... 2028 * XXX: The "Net/3" implementation doesn't imply that the TCP 2029 * reassembly queue should be flushed, but in a situation 2030 * where we're really low on mbufs, this is potentially 2031 * useful. 2032 */ 2033 INP_INFO_WLOCK(&V_tcbinfo); 2034 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2035 INP_WLOCK(inpb); 2036 if (inpb->inp_flags & INP_TIMEWAIT) { 2037 INP_WUNLOCK(inpb); 2038 continue; 2039 } 2040 if ((tcpb = intotcpcb(inpb)) != NULL) { 2041 tcp_reass_flush(tcpb); 2042 tcp_clean_sackreport(tcpb); 2043 #ifdef TCP_BLACKBOX 2044 tcp_log_drain(tcpb); 2045 #endif 2046 #ifdef TCPPCAP 2047 if (tcp_pcap_aggressive_free) { 2048 /* Free the TCP PCAP queues. */ 2049 tcp_pcap_drain(&(tcpb->t_inpkts)); 2050 tcp_pcap_drain(&(tcpb->t_outpkts)); 2051 } 2052 #endif 2053 } 2054 INP_WUNLOCK(inpb); 2055 } 2056 INP_INFO_WUNLOCK(&V_tcbinfo); 2057 CURVNET_RESTORE(); 2058 } 2059 VNET_LIST_RUNLOCK_NOSLEEP(); 2060 } 2061 2062 /* 2063 * Notify a tcp user of an asynchronous error; 2064 * store error as soft error, but wake up user 2065 * (for now, won't do anything until can select for soft error). 2066 * 2067 * Do not wake up user since there currently is no mechanism for 2068 * reporting soft errors (yet - a kqueue filter may be added). 2069 */ 2070 static struct inpcb * 2071 tcp_notify(struct inpcb *inp, int error) 2072 { 2073 struct tcpcb *tp; 2074 2075 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2076 INP_WLOCK_ASSERT(inp); 2077 2078 if ((inp->inp_flags & INP_TIMEWAIT) || 2079 (inp->inp_flags & INP_DROPPED)) 2080 return (inp); 2081 2082 tp = intotcpcb(inp); 2083 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2084 2085 /* 2086 * Ignore some errors if we are hooked up. 2087 * If connection hasn't completed, has retransmitted several times, 2088 * and receives a second error, give up now. This is better 2089 * than waiting a long time to establish a connection that 2090 * can never complete. 2091 */ 2092 if (tp->t_state == TCPS_ESTABLISHED && 2093 (error == EHOSTUNREACH || error == ENETUNREACH || 2094 error == EHOSTDOWN)) { 2095 if (inp->inp_route.ro_rt) { 2096 RTFREE(inp->inp_route.ro_rt); 2097 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2098 } 2099 return (inp); 2100 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2101 tp->t_softerror) { 2102 tp = tcp_drop(tp, error); 2103 if (tp != NULL) 2104 return (inp); 2105 else 2106 return (NULL); 2107 } else { 2108 tp->t_softerror = error; 2109 return (inp); 2110 } 2111 #if 0 2112 wakeup( &so->so_timeo); 2113 sorwakeup(so); 2114 sowwakeup(so); 2115 #endif 2116 } 2117 2118 static int 2119 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2120 { 2121 int error, i, m, n, pcb_count; 2122 struct inpcb *inp, **inp_list; 2123 inp_gen_t gencnt; 2124 struct xinpgen xig; 2125 struct epoch_tracker et; 2126 2127 /* 2128 * The process of preparing the TCB list is too time-consuming and 2129 * resource-intensive to repeat twice on every request. 2130 */ 2131 if (req->oldptr == NULL) { 2132 n = V_tcbinfo.ipi_count + 2133 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2134 n += imax(n / 8, 10); 2135 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2136 return (0); 2137 } 2138 2139 if (req->newptr != NULL) 2140 return (EPERM); 2141 2142 /* 2143 * OK, now we're committed to doing something. 2144 */ 2145 INP_LIST_RLOCK(&V_tcbinfo); 2146 gencnt = V_tcbinfo.ipi_gencnt; 2147 n = V_tcbinfo.ipi_count; 2148 INP_LIST_RUNLOCK(&V_tcbinfo); 2149 2150 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2151 2152 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2153 + (n + m) * sizeof(struct xtcpcb)); 2154 if (error != 0) 2155 return (error); 2156 2157 xig.xig_len = sizeof xig; 2158 xig.xig_count = n + m; 2159 xig.xig_gen = gencnt; 2160 xig.xig_sogen = so_gencnt; 2161 error = SYSCTL_OUT(req, &xig, sizeof xig); 2162 if (error) 2163 return (error); 2164 2165 error = syncache_pcblist(req, m, &pcb_count); 2166 if (error) 2167 return (error); 2168 2169 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2170 2171 INP_INFO_WLOCK(&V_tcbinfo); 2172 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2173 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) { 2174 INP_WLOCK(inp); 2175 if (inp->inp_gencnt <= gencnt) { 2176 /* 2177 * XXX: This use of cr_cansee(), introduced with 2178 * TCP state changes, is not quite right, but for 2179 * now, better than nothing. 2180 */ 2181 if (inp->inp_flags & INP_TIMEWAIT) { 2182 if (intotw(inp) != NULL) 2183 error = cr_cansee(req->td->td_ucred, 2184 intotw(inp)->tw_cred); 2185 else 2186 error = EINVAL; /* Skip this inp. */ 2187 } else 2188 error = cr_canseeinpcb(req->td->td_ucred, inp); 2189 if (error == 0) { 2190 in_pcbref(inp); 2191 inp_list[i++] = inp; 2192 } 2193 } 2194 INP_WUNLOCK(inp); 2195 } 2196 INP_INFO_WUNLOCK(&V_tcbinfo); 2197 n = i; 2198 2199 error = 0; 2200 for (i = 0; i < n; i++) { 2201 inp = inp_list[i]; 2202 INP_RLOCK(inp); 2203 if (inp->inp_gencnt <= gencnt) { 2204 struct xtcpcb xt; 2205 2206 tcp_inptoxtp(inp, &xt); 2207 INP_RUNLOCK(inp); 2208 error = SYSCTL_OUT(req, &xt, sizeof xt); 2209 } else 2210 INP_RUNLOCK(inp); 2211 } 2212 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2213 for (i = 0; i < n; i++) { 2214 inp = inp_list[i]; 2215 INP_RLOCK(inp); 2216 if (!in_pcbrele_rlocked(inp)) 2217 INP_RUNLOCK(inp); 2218 } 2219 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2220 2221 if (!error) { 2222 /* 2223 * Give the user an updated idea of our state. 2224 * If the generation differs from what we told 2225 * her before, she knows that something happened 2226 * while we were processing this request, and it 2227 * might be necessary to retry. 2228 */ 2229 INP_LIST_RLOCK(&V_tcbinfo); 2230 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2231 xig.xig_sogen = so_gencnt; 2232 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2233 INP_LIST_RUNLOCK(&V_tcbinfo); 2234 error = SYSCTL_OUT(req, &xig, sizeof xig); 2235 } 2236 free(inp_list, M_TEMP); 2237 return (error); 2238 } 2239 2240 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2241 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2242 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2243 2244 #ifdef INET 2245 static int 2246 tcp_getcred(SYSCTL_HANDLER_ARGS) 2247 { 2248 struct xucred xuc; 2249 struct sockaddr_in addrs[2]; 2250 struct inpcb *inp; 2251 int error; 2252 2253 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2254 if (error) 2255 return (error); 2256 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2257 if (error) 2258 return (error); 2259 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2260 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2261 if (inp != NULL) { 2262 if (inp->inp_socket == NULL) 2263 error = ENOENT; 2264 if (error == 0) 2265 error = cr_canseeinpcb(req->td->td_ucred, inp); 2266 if (error == 0) 2267 cru2x(inp->inp_cred, &xuc); 2268 INP_RUNLOCK(inp); 2269 } else 2270 error = ENOENT; 2271 if (error == 0) 2272 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2273 return (error); 2274 } 2275 2276 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2277 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2278 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2279 #endif /* INET */ 2280 2281 #ifdef INET6 2282 static int 2283 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2284 { 2285 struct xucred xuc; 2286 struct sockaddr_in6 addrs[2]; 2287 struct inpcb *inp; 2288 int error; 2289 #ifdef INET 2290 int mapped = 0; 2291 #endif 2292 2293 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2294 if (error) 2295 return (error); 2296 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2297 if (error) 2298 return (error); 2299 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2300 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2301 return (error); 2302 } 2303 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2304 #ifdef INET 2305 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2306 mapped = 1; 2307 else 2308 #endif 2309 return (EINVAL); 2310 } 2311 2312 #ifdef INET 2313 if (mapped == 1) 2314 inp = in_pcblookup(&V_tcbinfo, 2315 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2316 addrs[1].sin6_port, 2317 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2318 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2319 else 2320 #endif 2321 inp = in6_pcblookup(&V_tcbinfo, 2322 &addrs[1].sin6_addr, addrs[1].sin6_port, 2323 &addrs[0].sin6_addr, addrs[0].sin6_port, 2324 INPLOOKUP_RLOCKPCB, NULL); 2325 if (inp != NULL) { 2326 if (inp->inp_socket == NULL) 2327 error = ENOENT; 2328 if (error == 0) 2329 error = cr_canseeinpcb(req->td->td_ucred, inp); 2330 if (error == 0) 2331 cru2x(inp->inp_cred, &xuc); 2332 INP_RUNLOCK(inp); 2333 } else 2334 error = ENOENT; 2335 if (error == 0) 2336 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2337 return (error); 2338 } 2339 2340 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2341 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2342 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2343 #endif /* INET6 */ 2344 2345 2346 #ifdef INET 2347 void 2348 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2349 { 2350 struct ip *ip = vip; 2351 struct tcphdr *th; 2352 struct in_addr faddr; 2353 struct inpcb *inp; 2354 struct tcpcb *tp; 2355 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2356 struct icmp *icp; 2357 struct in_conninfo inc; 2358 struct epoch_tracker et; 2359 tcp_seq icmp_tcp_seq; 2360 int mtu; 2361 2362 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2363 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2364 return; 2365 2366 if (cmd == PRC_MSGSIZE) 2367 notify = tcp_mtudisc_notify; 2368 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2369 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2370 cmd == PRC_TIMXCEED_INTRANS) && ip) 2371 notify = tcp_drop_syn_sent; 2372 2373 /* 2374 * Hostdead is ugly because it goes linearly through all PCBs. 2375 * XXX: We never get this from ICMP, otherwise it makes an 2376 * excellent DoS attack on machines with many connections. 2377 */ 2378 else if (cmd == PRC_HOSTDEAD) 2379 ip = NULL; 2380 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2381 return; 2382 2383 if (ip == NULL) { 2384 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2385 return; 2386 } 2387 2388 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2389 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2390 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2391 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2392 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2393 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2394 /* signal EHOSTDOWN, as it flushes the cached route */ 2395 inp = (*notify)(inp, EHOSTDOWN); 2396 goto out; 2397 } 2398 icmp_tcp_seq = th->th_seq; 2399 if (inp != NULL) { 2400 if (!(inp->inp_flags & INP_TIMEWAIT) && 2401 !(inp->inp_flags & INP_DROPPED) && 2402 !(inp->inp_socket == NULL)) { 2403 tp = intotcpcb(inp); 2404 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2405 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2406 if (cmd == PRC_MSGSIZE) { 2407 /* 2408 * MTU discovery: 2409 * If we got a needfrag set the MTU 2410 * in the route to the suggested new 2411 * value (if given) and then notify. 2412 */ 2413 mtu = ntohs(icp->icmp_nextmtu); 2414 /* 2415 * If no alternative MTU was 2416 * proposed, try the next smaller 2417 * one. 2418 */ 2419 if (!mtu) 2420 mtu = ip_next_mtu( 2421 ntohs(ip->ip_len), 1); 2422 if (mtu < V_tcp_minmss + 2423 sizeof(struct tcpiphdr)) 2424 mtu = V_tcp_minmss + 2425 sizeof(struct tcpiphdr); 2426 /* 2427 * Only process the offered MTU if it 2428 * is smaller than the current one. 2429 */ 2430 if (mtu < tp->t_maxseg + 2431 sizeof(struct tcpiphdr)) { 2432 bzero(&inc, sizeof(inc)); 2433 inc.inc_faddr = faddr; 2434 inc.inc_fibnum = 2435 inp->inp_inc.inc_fibnum; 2436 tcp_hc_updatemtu(&inc, mtu); 2437 tcp_mtudisc(inp, mtu); 2438 } 2439 } else 2440 inp = (*notify)(inp, 2441 inetctlerrmap[cmd]); 2442 } 2443 } 2444 } else { 2445 bzero(&inc, sizeof(inc)); 2446 inc.inc_fport = th->th_dport; 2447 inc.inc_lport = th->th_sport; 2448 inc.inc_faddr = faddr; 2449 inc.inc_laddr = ip->ip_src; 2450 syncache_unreach(&inc, icmp_tcp_seq); 2451 } 2452 out: 2453 if (inp != NULL) 2454 INP_WUNLOCK(inp); 2455 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2456 } 2457 #endif /* INET */ 2458 2459 #ifdef INET6 2460 void 2461 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2462 { 2463 struct in6_addr *dst; 2464 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2465 struct ip6_hdr *ip6; 2466 struct mbuf *m; 2467 struct inpcb *inp; 2468 struct tcpcb *tp; 2469 struct icmp6_hdr *icmp6; 2470 struct ip6ctlparam *ip6cp = NULL; 2471 const struct sockaddr_in6 *sa6_src = NULL; 2472 struct in_conninfo inc; 2473 struct epoch_tracker et; 2474 struct tcp_ports { 2475 uint16_t th_sport; 2476 uint16_t th_dport; 2477 } t_ports; 2478 tcp_seq icmp_tcp_seq; 2479 unsigned int mtu; 2480 unsigned int off; 2481 2482 if (sa->sa_family != AF_INET6 || 2483 sa->sa_len != sizeof(struct sockaddr_in6)) 2484 return; 2485 2486 /* if the parameter is from icmp6, decode it. */ 2487 if (d != NULL) { 2488 ip6cp = (struct ip6ctlparam *)d; 2489 icmp6 = ip6cp->ip6c_icmp6; 2490 m = ip6cp->ip6c_m; 2491 ip6 = ip6cp->ip6c_ip6; 2492 off = ip6cp->ip6c_off; 2493 sa6_src = ip6cp->ip6c_src; 2494 dst = ip6cp->ip6c_finaldst; 2495 } else { 2496 m = NULL; 2497 ip6 = NULL; 2498 off = 0; /* fool gcc */ 2499 sa6_src = &sa6_any; 2500 dst = NULL; 2501 } 2502 2503 if (cmd == PRC_MSGSIZE) 2504 notify = tcp_mtudisc_notify; 2505 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2506 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2507 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2508 notify = tcp_drop_syn_sent; 2509 2510 /* 2511 * Hostdead is ugly because it goes linearly through all PCBs. 2512 * XXX: We never get this from ICMP, otherwise it makes an 2513 * excellent DoS attack on machines with many connections. 2514 */ 2515 else if (cmd == PRC_HOSTDEAD) 2516 ip6 = NULL; 2517 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2518 return; 2519 2520 if (ip6 == NULL) { 2521 in6_pcbnotify(&V_tcbinfo, sa, 0, 2522 (const struct sockaddr *)sa6_src, 2523 0, cmd, NULL, notify); 2524 return; 2525 } 2526 2527 /* Check if we can safely get the ports from the tcp hdr */ 2528 if (m == NULL || 2529 (m->m_pkthdr.len < 2530 (int32_t) (off + sizeof(struct tcp_ports)))) { 2531 return; 2532 } 2533 bzero(&t_ports, sizeof(struct tcp_ports)); 2534 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2535 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2536 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2537 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2538 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2539 /* signal EHOSTDOWN, as it flushes the cached route */ 2540 inp = (*notify)(inp, EHOSTDOWN); 2541 goto out; 2542 } 2543 off += sizeof(struct tcp_ports); 2544 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2545 goto out; 2546 } 2547 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2548 if (inp != NULL) { 2549 if (!(inp->inp_flags & INP_TIMEWAIT) && 2550 !(inp->inp_flags & INP_DROPPED) && 2551 !(inp->inp_socket == NULL)) { 2552 tp = intotcpcb(inp); 2553 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2554 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2555 if (cmd == PRC_MSGSIZE) { 2556 /* 2557 * MTU discovery: 2558 * If we got a needfrag set the MTU 2559 * in the route to the suggested new 2560 * value (if given) and then notify. 2561 */ 2562 mtu = ntohl(icmp6->icmp6_mtu); 2563 /* 2564 * If no alternative MTU was 2565 * proposed, or the proposed 2566 * MTU was too small, set to 2567 * the min. 2568 */ 2569 if (mtu < IPV6_MMTU) 2570 mtu = IPV6_MMTU - 8; 2571 bzero(&inc, sizeof(inc)); 2572 inc.inc_fibnum = M_GETFIB(m); 2573 inc.inc_flags |= INC_ISIPV6; 2574 inc.inc6_faddr = *dst; 2575 if (in6_setscope(&inc.inc6_faddr, 2576 m->m_pkthdr.rcvif, NULL)) 2577 goto out; 2578 /* 2579 * Only process the offered MTU if it 2580 * is smaller than the current one. 2581 */ 2582 if (mtu < tp->t_maxseg + 2583 sizeof (struct tcphdr) + 2584 sizeof (struct ip6_hdr)) { 2585 tcp_hc_updatemtu(&inc, mtu); 2586 tcp_mtudisc(inp, mtu); 2587 ICMP6STAT_INC(icp6s_pmtuchg); 2588 } 2589 } else 2590 inp = (*notify)(inp, 2591 inet6ctlerrmap[cmd]); 2592 } 2593 } 2594 } else { 2595 bzero(&inc, sizeof(inc)); 2596 inc.inc_fibnum = M_GETFIB(m); 2597 inc.inc_flags |= INC_ISIPV6; 2598 inc.inc_fport = t_ports.th_dport; 2599 inc.inc_lport = t_ports.th_sport; 2600 inc.inc6_faddr = *dst; 2601 inc.inc6_laddr = ip6->ip6_src; 2602 syncache_unreach(&inc, icmp_tcp_seq); 2603 } 2604 out: 2605 if (inp != NULL) 2606 INP_WUNLOCK(inp); 2607 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2608 } 2609 #endif /* INET6 */ 2610 2611 static uint32_t 2612 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2613 { 2614 MD5_CTX ctx; 2615 uint32_t hash[4]; 2616 2617 MD5Init(&ctx); 2618 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2619 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2620 switch (inc->inc_flags & INC_ISIPV6) { 2621 #ifdef INET 2622 case 0: 2623 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2624 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2625 break; 2626 #endif 2627 #ifdef INET6 2628 case INC_ISIPV6: 2629 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2630 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2631 break; 2632 #endif 2633 } 2634 MD5Update(&ctx, key, len); 2635 MD5Final((unsigned char *)hash, &ctx); 2636 2637 return (hash[0]); 2638 } 2639 2640 uint32_t 2641 tcp_new_ts_offset(struct in_conninfo *inc) 2642 { 2643 return (tcp_keyed_hash(inc, V_ts_offset_secret, 2644 sizeof(V_ts_offset_secret))); 2645 } 2646 2647 /* 2648 * Following is where TCP initial sequence number generation occurs. 2649 * 2650 * There are two places where we must use initial sequence numbers: 2651 * 1. In SYN-ACK packets. 2652 * 2. In SYN packets. 2653 * 2654 * All ISNs for SYN-ACK packets are generated by the syncache. See 2655 * tcp_syncache.c for details. 2656 * 2657 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2658 * depends on this property. In addition, these ISNs should be 2659 * unguessable so as to prevent connection hijacking. To satisfy 2660 * the requirements of this situation, the algorithm outlined in 2661 * RFC 1948 is used, with only small modifications. 2662 * 2663 * Implementation details: 2664 * 2665 * Time is based off the system timer, and is corrected so that it 2666 * increases by one megabyte per second. This allows for proper 2667 * recycling on high speed LANs while still leaving over an hour 2668 * before rollover. 2669 * 2670 * As reading the *exact* system time is too expensive to be done 2671 * whenever setting up a TCP connection, we increment the time 2672 * offset in two ways. First, a small random positive increment 2673 * is added to isn_offset for each connection that is set up. 2674 * Second, the function tcp_isn_tick fires once per clock tick 2675 * and increments isn_offset as necessary so that sequence numbers 2676 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2677 * random positive increments serve only to ensure that the same 2678 * exact sequence number is never sent out twice (as could otherwise 2679 * happen when a port is recycled in less than the system tick 2680 * interval.) 2681 * 2682 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2683 * between seeding of isn_secret. This is normally set to zero, 2684 * as reseeding should not be necessary. 2685 * 2686 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2687 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2688 * general, this means holding an exclusive (write) lock. 2689 */ 2690 2691 #define ISN_BYTES_PER_SECOND 1048576 2692 #define ISN_STATIC_INCREMENT 4096 2693 #define ISN_RANDOM_INCREMENT (4096 - 1) 2694 #define ISN_SECRET_LENGTH 32 2695 2696 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2697 VNET_DEFINE_STATIC(int, isn_last); 2698 VNET_DEFINE_STATIC(int, isn_last_reseed); 2699 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2700 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2701 2702 #define V_isn_secret VNET(isn_secret) 2703 #define V_isn_last VNET(isn_last) 2704 #define V_isn_last_reseed VNET(isn_last_reseed) 2705 #define V_isn_offset VNET(isn_offset) 2706 #define V_isn_offset_old VNET(isn_offset_old) 2707 2708 tcp_seq 2709 tcp_new_isn(struct in_conninfo *inc) 2710 { 2711 tcp_seq new_isn; 2712 u_int32_t projected_offset; 2713 2714 ISN_LOCK(); 2715 /* Seed if this is the first use, reseed if requested. */ 2716 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2717 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2718 < (u_int)ticks))) { 2719 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2720 V_isn_last_reseed = ticks; 2721 } 2722 2723 /* Compute the md5 hash and return the ISN. */ 2724 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2725 sizeof(V_isn_secret)); 2726 V_isn_offset += ISN_STATIC_INCREMENT + 2727 (arc4random() & ISN_RANDOM_INCREMENT); 2728 if (ticks != V_isn_last) { 2729 projected_offset = V_isn_offset_old + 2730 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2731 if (SEQ_GT(projected_offset, V_isn_offset)) 2732 V_isn_offset = projected_offset; 2733 V_isn_offset_old = V_isn_offset; 2734 V_isn_last = ticks; 2735 } 2736 new_isn += V_isn_offset; 2737 ISN_UNLOCK(); 2738 return (new_isn); 2739 } 2740 2741 /* 2742 * When a specific ICMP unreachable message is received and the 2743 * connection state is SYN-SENT, drop the connection. This behavior 2744 * is controlled by the icmp_may_rst sysctl. 2745 */ 2746 struct inpcb * 2747 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2748 { 2749 struct tcpcb *tp; 2750 2751 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2752 INP_WLOCK_ASSERT(inp); 2753 2754 if ((inp->inp_flags & INP_TIMEWAIT) || 2755 (inp->inp_flags & INP_DROPPED)) 2756 return (inp); 2757 2758 tp = intotcpcb(inp); 2759 if (tp->t_state != TCPS_SYN_SENT) 2760 return (inp); 2761 2762 if (IS_FASTOPEN(tp->t_flags)) 2763 tcp_fastopen_disable_path(tp); 2764 2765 tp = tcp_drop(tp, errno); 2766 if (tp != NULL) 2767 return (inp); 2768 else 2769 return (NULL); 2770 } 2771 2772 /* 2773 * When `need fragmentation' ICMP is received, update our idea of the MSS 2774 * based on the new value. Also nudge TCP to send something, since we 2775 * know the packet we just sent was dropped. 2776 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2777 */ 2778 static struct inpcb * 2779 tcp_mtudisc_notify(struct inpcb *inp, int error) 2780 { 2781 2782 tcp_mtudisc(inp, -1); 2783 return (inp); 2784 } 2785 2786 static void 2787 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2788 { 2789 struct tcpcb *tp; 2790 struct socket *so; 2791 2792 INP_WLOCK_ASSERT(inp); 2793 if ((inp->inp_flags & INP_TIMEWAIT) || 2794 (inp->inp_flags & INP_DROPPED)) 2795 return; 2796 2797 tp = intotcpcb(inp); 2798 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2799 2800 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2801 2802 so = inp->inp_socket; 2803 SOCKBUF_LOCK(&so->so_snd); 2804 /* If the mss is larger than the socket buffer, decrease the mss. */ 2805 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2806 tp->t_maxseg = so->so_snd.sb_hiwat; 2807 SOCKBUF_UNLOCK(&so->so_snd); 2808 2809 TCPSTAT_INC(tcps_mturesent); 2810 tp->t_rtttime = 0; 2811 tp->snd_nxt = tp->snd_una; 2812 tcp_free_sackholes(tp); 2813 tp->snd_recover = tp->snd_max; 2814 if (tp->t_flags & TF_SACK_PERMIT) 2815 EXIT_FASTRECOVERY(tp->t_flags); 2816 tp->t_fb->tfb_tcp_output(tp); 2817 } 2818 2819 #ifdef INET 2820 /* 2821 * Look-up the routing entry to the peer of this inpcb. If no route 2822 * is found and it cannot be allocated, then return 0. This routine 2823 * is called by TCP routines that access the rmx structure and by 2824 * tcp_mss_update to get the peer/interface MTU. 2825 */ 2826 uint32_t 2827 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2828 { 2829 struct nhop4_extended nh4; 2830 struct ifnet *ifp; 2831 uint32_t maxmtu = 0; 2832 2833 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2834 2835 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2836 2837 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2838 NHR_REF, 0, &nh4) != 0) 2839 return (0); 2840 2841 ifp = nh4.nh_ifp; 2842 maxmtu = nh4.nh_mtu; 2843 2844 /* Report additional interface capabilities. */ 2845 if (cap != NULL) { 2846 if (ifp->if_capenable & IFCAP_TSO4 && 2847 ifp->if_hwassist & CSUM_TSO) { 2848 cap->ifcap |= CSUM_TSO; 2849 cap->tsomax = ifp->if_hw_tsomax; 2850 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2851 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2852 } 2853 } 2854 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2855 } 2856 return (maxmtu); 2857 } 2858 #endif /* INET */ 2859 2860 #ifdef INET6 2861 uint32_t 2862 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2863 { 2864 struct nhop6_extended nh6; 2865 struct in6_addr dst6; 2866 uint32_t scopeid; 2867 struct ifnet *ifp; 2868 uint32_t maxmtu = 0; 2869 2870 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2871 2872 if (inc->inc_flags & INC_IPV6MINMTU) 2873 return (IPV6_MMTU); 2874 2875 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2876 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2877 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2878 0, &nh6) != 0) 2879 return (0); 2880 2881 ifp = nh6.nh_ifp; 2882 maxmtu = nh6.nh_mtu; 2883 2884 /* Report additional interface capabilities. */ 2885 if (cap != NULL) { 2886 if (ifp->if_capenable & IFCAP_TSO6 && 2887 ifp->if_hwassist & CSUM_TSO) { 2888 cap->ifcap |= CSUM_TSO; 2889 cap->tsomax = ifp->if_hw_tsomax; 2890 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2891 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2892 } 2893 } 2894 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2895 } 2896 2897 return (maxmtu); 2898 } 2899 #endif /* INET6 */ 2900 2901 /* 2902 * Calculate effective SMSS per RFC5681 definition for a given TCP 2903 * connection at its current state, taking into account SACK and etc. 2904 */ 2905 u_int 2906 tcp_maxseg(const struct tcpcb *tp) 2907 { 2908 u_int optlen; 2909 2910 if (tp->t_flags & TF_NOOPT) 2911 return (tp->t_maxseg); 2912 2913 /* 2914 * Here we have a simplified code from tcp_addoptions(), 2915 * without a proper loop, and having most of paddings hardcoded. 2916 * We might make mistakes with padding here in some edge cases, 2917 * but this is harmless, since result of tcp_maxseg() is used 2918 * only in cwnd and ssthresh estimations. 2919 */ 2920 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2921 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2922 if (tp->t_flags & TF_RCVD_TSTMP) 2923 optlen = TCPOLEN_TSTAMP_APPA; 2924 else 2925 optlen = 0; 2926 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2927 if (tp->t_flags & TF_SIGNATURE) 2928 optlen += PAD(TCPOLEN_SIGNATURE); 2929 #endif 2930 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2931 optlen += TCPOLEN_SACKHDR; 2932 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2933 optlen = PAD(optlen); 2934 } 2935 } else { 2936 if (tp->t_flags & TF_REQ_TSTMP) 2937 optlen = TCPOLEN_TSTAMP_APPA; 2938 else 2939 optlen = PAD(TCPOLEN_MAXSEG); 2940 if (tp->t_flags & TF_REQ_SCALE) 2941 optlen += PAD(TCPOLEN_WINDOW); 2942 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2943 if (tp->t_flags & TF_SIGNATURE) 2944 optlen += PAD(TCPOLEN_SIGNATURE); 2945 #endif 2946 if (tp->t_flags & TF_SACK_PERMIT) 2947 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2948 } 2949 #undef PAD 2950 optlen = min(optlen, TCP_MAXOLEN); 2951 return (tp->t_maxseg - optlen); 2952 } 2953 2954 static int 2955 sysctl_drop(SYSCTL_HANDLER_ARGS) 2956 { 2957 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2958 struct sockaddr_storage addrs[2]; 2959 struct inpcb *inp; 2960 struct tcpcb *tp; 2961 struct tcptw *tw; 2962 struct sockaddr_in *fin, *lin; 2963 struct epoch_tracker et; 2964 #ifdef INET6 2965 struct sockaddr_in6 *fin6, *lin6; 2966 #endif 2967 int error; 2968 2969 inp = NULL; 2970 fin = lin = NULL; 2971 #ifdef INET6 2972 fin6 = lin6 = NULL; 2973 #endif 2974 error = 0; 2975 2976 if (req->oldptr != NULL || req->oldlen != 0) 2977 return (EINVAL); 2978 if (req->newptr == NULL) 2979 return (EPERM); 2980 if (req->newlen < sizeof(addrs)) 2981 return (ENOMEM); 2982 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2983 if (error) 2984 return (error); 2985 2986 switch (addrs[0].ss_family) { 2987 #ifdef INET6 2988 case AF_INET6: 2989 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2990 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2991 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2992 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2993 return (EINVAL); 2994 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2995 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2996 return (EINVAL); 2997 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2998 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2999 fin = (struct sockaddr_in *)&addrs[0]; 3000 lin = (struct sockaddr_in *)&addrs[1]; 3001 break; 3002 } 3003 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3004 if (error) 3005 return (error); 3006 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3007 if (error) 3008 return (error); 3009 break; 3010 #endif 3011 #ifdef INET 3012 case AF_INET: 3013 fin = (struct sockaddr_in *)&addrs[0]; 3014 lin = (struct sockaddr_in *)&addrs[1]; 3015 if (fin->sin_len != sizeof(struct sockaddr_in) || 3016 lin->sin_len != sizeof(struct sockaddr_in)) 3017 return (EINVAL); 3018 break; 3019 #endif 3020 default: 3021 return (EINVAL); 3022 } 3023 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3024 switch (addrs[0].ss_family) { 3025 #ifdef INET6 3026 case AF_INET6: 3027 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3028 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3029 INPLOOKUP_WLOCKPCB, NULL); 3030 break; 3031 #endif 3032 #ifdef INET 3033 case AF_INET: 3034 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3035 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3036 break; 3037 #endif 3038 } 3039 if (inp != NULL) { 3040 if (inp->inp_flags & INP_TIMEWAIT) { 3041 /* 3042 * XXXRW: There currently exists a state where an 3043 * inpcb is present, but its timewait state has been 3044 * discarded. For now, don't allow dropping of this 3045 * type of inpcb. 3046 */ 3047 tw = intotw(inp); 3048 if (tw != NULL) 3049 tcp_twclose(tw, 0); 3050 else 3051 INP_WUNLOCK(inp); 3052 } else if (!(inp->inp_flags & INP_DROPPED) && 3053 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3054 tp = intotcpcb(inp); 3055 tp = tcp_drop(tp, ECONNABORTED); 3056 if (tp != NULL) 3057 INP_WUNLOCK(inp); 3058 } else 3059 INP_WUNLOCK(inp); 3060 } else 3061 error = ESRCH; 3062 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3063 return (error); 3064 } 3065 3066 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3067 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3068 0, sysctl_drop, "", "Drop TCP connection"); 3069 3070 /* 3071 * Generate a standardized TCP log line for use throughout the 3072 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3073 * allow use in the interrupt context. 3074 * 3075 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3076 * NB: The function may return NULL if memory allocation failed. 3077 * 3078 * Due to header inclusion and ordering limitations the struct ip 3079 * and ip6_hdr pointers have to be passed as void pointers. 3080 */ 3081 char * 3082 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3083 const void *ip6hdr) 3084 { 3085 3086 /* Is logging enabled? */ 3087 if (tcp_log_in_vain == 0) 3088 return (NULL); 3089 3090 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3091 } 3092 3093 char * 3094 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3095 const void *ip6hdr) 3096 { 3097 3098 /* Is logging enabled? */ 3099 if (tcp_log_debug == 0) 3100 return (NULL); 3101 3102 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3103 } 3104 3105 static char * 3106 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3107 const void *ip6hdr) 3108 { 3109 char *s, *sp; 3110 size_t size; 3111 struct ip *ip; 3112 #ifdef INET6 3113 const struct ip6_hdr *ip6; 3114 3115 ip6 = (const struct ip6_hdr *)ip6hdr; 3116 #endif /* INET6 */ 3117 ip = (struct ip *)ip4hdr; 3118 3119 /* 3120 * The log line looks like this: 3121 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3122 */ 3123 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3124 sizeof(PRINT_TH_FLAGS) + 1 + 3125 #ifdef INET6 3126 2 * INET6_ADDRSTRLEN; 3127 #else 3128 2 * INET_ADDRSTRLEN; 3129 #endif /* INET6 */ 3130 3131 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3132 if (s == NULL) 3133 return (NULL); 3134 3135 strcat(s, "TCP: ["); 3136 sp = s + strlen(s); 3137 3138 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3139 inet_ntoa_r(inc->inc_faddr, sp); 3140 sp = s + strlen(s); 3141 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3142 sp = s + strlen(s); 3143 inet_ntoa_r(inc->inc_laddr, sp); 3144 sp = s + strlen(s); 3145 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3146 #ifdef INET6 3147 } else if (inc) { 3148 ip6_sprintf(sp, &inc->inc6_faddr); 3149 sp = s + strlen(s); 3150 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3151 sp = s + strlen(s); 3152 ip6_sprintf(sp, &inc->inc6_laddr); 3153 sp = s + strlen(s); 3154 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3155 } else if (ip6 && th) { 3156 ip6_sprintf(sp, &ip6->ip6_src); 3157 sp = s + strlen(s); 3158 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3159 sp = s + strlen(s); 3160 ip6_sprintf(sp, &ip6->ip6_dst); 3161 sp = s + strlen(s); 3162 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3163 #endif /* INET6 */ 3164 #ifdef INET 3165 } else if (ip && th) { 3166 inet_ntoa_r(ip->ip_src, sp); 3167 sp = s + strlen(s); 3168 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3169 sp = s + strlen(s); 3170 inet_ntoa_r(ip->ip_dst, sp); 3171 sp = s + strlen(s); 3172 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3173 #endif /* INET */ 3174 } else { 3175 free(s, M_TCPLOG); 3176 return (NULL); 3177 } 3178 sp = s + strlen(s); 3179 if (th) 3180 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3181 if (*(s + size - 1) != '\0') 3182 panic("%s: string too long", __func__); 3183 return (s); 3184 } 3185 3186 /* 3187 * A subroutine which makes it easy to track TCP state changes with DTrace. 3188 * This function shouldn't be called for t_state initializations that don't 3189 * correspond to actual TCP state transitions. 3190 */ 3191 void 3192 tcp_state_change(struct tcpcb *tp, int newstate) 3193 { 3194 #if defined(KDTRACE_HOOKS) 3195 int pstate = tp->t_state; 3196 #endif 3197 3198 TCPSTATES_DEC(tp->t_state); 3199 TCPSTATES_INC(newstate); 3200 tp->t_state = newstate; 3201 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3202 } 3203 3204 /* 3205 * Create an external-format (``xtcpcb'') structure using the information in 3206 * the kernel-format tcpcb structure pointed to by tp. This is done to 3207 * reduce the spew of irrelevant information over this interface, to isolate 3208 * user code from changes in the kernel structure, and potentially to provide 3209 * information-hiding if we decide that some of this information should be 3210 * hidden from users. 3211 */ 3212 void 3213 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3214 { 3215 struct tcpcb *tp = intotcpcb(inp); 3216 sbintime_t now; 3217 3218 if (inp->inp_flags & INP_TIMEWAIT) { 3219 bzero(xt, sizeof(struct xtcpcb)); 3220 xt->t_state = TCPS_TIME_WAIT; 3221 } else { 3222 xt->t_state = tp->t_state; 3223 xt->t_logstate = tp->t_logstate; 3224 xt->t_flags = tp->t_flags; 3225 xt->t_sndzerowin = tp->t_sndzerowin; 3226 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3227 xt->t_rcvoopack = tp->t_rcvoopack; 3228 3229 now = getsbinuptime(); 3230 #define COPYTIMER(ttt) do { \ 3231 if (callout_active(&tp->t_timers->ttt)) \ 3232 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3233 SBT_1MS; \ 3234 else \ 3235 xt->ttt = 0; \ 3236 } while (0) 3237 COPYTIMER(tt_delack); 3238 COPYTIMER(tt_rexmt); 3239 COPYTIMER(tt_persist); 3240 COPYTIMER(tt_keep); 3241 COPYTIMER(tt_2msl); 3242 #undef COPYTIMER 3243 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3244 3245 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3246 TCP_FUNCTION_NAME_LEN_MAX); 3247 bzero(xt->xt_logid, TCP_LOG_ID_LEN); 3248 #ifdef TCP_BLACKBOX 3249 (void)tcp_log_get_id(tp, xt->xt_logid); 3250 #endif 3251 } 3252 3253 xt->xt_len = sizeof(struct xtcpcb); 3254 in_pcbtoxinpcb(inp, &xt->xt_inp); 3255 if (inp->inp_socket == NULL) 3256 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3257 } 3258