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 bzero(&tfi, sizeof(tfi)); 560 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 561 tfi.tfi_id = f->tf_fb->tfb_id; 562 (void)strncpy(tfi.tfi_alias, f->tf_name, 563 TCP_FUNCTION_NAME_LEN_MAX); 564 tfi.tfi_alias[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 565 (void)strncpy(tfi.tfi_name, 566 f->tf_fb->tfb_tcp_block_name, 567 TCP_FUNCTION_NAME_LEN_MAX); 568 tfi.tfi_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 569 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 570 /* 571 * Don't stop on error, as that is the 572 * mechanism we use to accumulate length 573 * information if the buffer was too short. 574 */ 575 } 576 } 577 KASSERT(cnt == tcp_fb_cnt, 578 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 579 #ifndef INVARIANTS 580 skip_loop: 581 #endif 582 rw_runlock(&tcp_function_lock); 583 if (req->oldptr == NULL) 584 error = SYSCTL_OUT(req, NULL, 585 (cnt + 1) * sizeof(struct tcp_function_info)); 586 587 return (error); 588 } 589 590 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 591 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 592 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 593 "List TCP function block name-to-ID mappings"); 594 595 /* 596 * tfb_tcp_handoff_ok() function for the default stack. 597 * Note that we'll basically try to take all comers. 598 */ 599 static int 600 tcp_default_handoff_ok(struct tcpcb *tp) 601 { 602 603 return (0); 604 } 605 606 /* 607 * tfb_tcp_fb_init() function for the default stack. 608 * 609 * This handles making sure we have appropriate timers set if you are 610 * transitioning a socket that has some amount of setup done. 611 * 612 * The init() fuction from the default can *never* return non-zero i.e. 613 * it is required to always succeed since it is the stack of last resort! 614 */ 615 static int 616 tcp_default_fb_init(struct tcpcb *tp) 617 { 618 619 struct socket *so; 620 621 INP_WLOCK_ASSERT(tp->t_inpcb); 622 623 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 624 ("%s: connection %p in unexpected state %d", __func__, tp, 625 tp->t_state)); 626 627 /* 628 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 629 * know what to do for unexpected states (which includes TIME_WAIT). 630 */ 631 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 632 return (0); 633 634 /* 635 * Make sure some kind of transmission timer is set if there is 636 * outstanding data. 637 */ 638 so = tp->t_inpcb->inp_socket; 639 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 640 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 641 tcp_timer_active(tp, TT_PERSIST))) { 642 /* 643 * If the session has established and it looks like it should 644 * be in the persist state, set the persist timer. Otherwise, 645 * set the retransmit timer. 646 */ 647 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 648 (int32_t)(tp->snd_nxt - tp->snd_una) < 649 (int32_t)sbavail(&so->so_snd)) 650 tcp_setpersist(tp); 651 else 652 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 653 } 654 655 /* All non-embryonic sessions get a keepalive timer. */ 656 if (!tcp_timer_active(tp, TT_KEEP)) 657 tcp_timer_activate(tp, TT_KEEP, 658 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 659 TP_KEEPINIT(tp)); 660 661 return (0); 662 } 663 664 /* 665 * tfb_tcp_fb_fini() function for the default stack. 666 * 667 * This changes state as necessary (or prudent) to prepare for another stack 668 * to assume responsibility for the connection. 669 */ 670 static void 671 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 672 { 673 674 INP_WLOCK_ASSERT(tp->t_inpcb); 675 return; 676 } 677 678 /* 679 * Target size of TCP PCB hash tables. Must be a power of two. 680 * 681 * Note that this can be overridden by the kernel environment 682 * variable net.inet.tcp.tcbhashsize 683 */ 684 #ifndef TCBHASHSIZE 685 #define TCBHASHSIZE 0 686 #endif 687 688 /* 689 * XXX 690 * Callouts should be moved into struct tcp directly. They are currently 691 * separate because the tcpcb structure is exported to userland for sysctl 692 * parsing purposes, which do not know about callouts. 693 */ 694 struct tcpcb_mem { 695 struct tcpcb tcb; 696 struct tcp_timer tt; 697 struct cc_var ccv; 698 #ifdef TCP_HHOOK 699 struct osd osd; 700 #endif 701 }; 702 703 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 704 #define V_tcpcb_zone VNET(tcpcb_zone) 705 706 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 707 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 708 709 static struct mtx isn_mtx; 710 711 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 712 #define ISN_LOCK() mtx_lock(&isn_mtx) 713 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 714 715 /* 716 * TCP initialization. 717 */ 718 static void 719 tcp_zone_change(void *tag) 720 { 721 722 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 723 uma_zone_set_max(V_tcpcb_zone, maxsockets); 724 tcp_tw_zone_change(); 725 } 726 727 static int 728 tcp_inpcb_init(void *mem, int size, int flags) 729 { 730 struct inpcb *inp = mem; 731 732 INP_LOCK_INIT(inp, "inp", "tcpinp"); 733 return (0); 734 } 735 736 /* 737 * Take a value and get the next power of 2 that doesn't overflow. 738 * Used to size the tcp_inpcb hash buckets. 739 */ 740 static int 741 maketcp_hashsize(int size) 742 { 743 int hashsize; 744 745 /* 746 * auto tune. 747 * get the next power of 2 higher than maxsockets. 748 */ 749 hashsize = 1 << fls(size); 750 /* catch overflow, and just go one power of 2 smaller */ 751 if (hashsize < size) { 752 hashsize = 1 << (fls(size) - 1); 753 } 754 return (hashsize); 755 } 756 757 static volatile int next_tcp_stack_id = 1; 758 759 /* 760 * Register a TCP function block with the name provided in the names 761 * array. (Note that this function does NOT automatically register 762 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 763 * explicitly include blk->tfb_tcp_block_name in the list of names if 764 * you wish to register the stack with that name.) 765 * 766 * Either all name registrations will succeed or all will fail. If 767 * a name registration fails, the function will update the num_names 768 * argument to point to the array index of the name that encountered 769 * the failure. 770 * 771 * Returns 0 on success, or an error code on failure. 772 */ 773 int 774 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 775 const char *names[], int *num_names) 776 { 777 struct tcp_function *n; 778 struct tcp_function_set fs; 779 int error, i; 780 781 KASSERT(names != NULL && *num_names > 0, 782 ("%s: Called with 0-length name list", __func__)); 783 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 784 785 if (t_functions_inited == 0) { 786 init_tcp_functions(); 787 } 788 if ((blk->tfb_tcp_output == NULL) || 789 (blk->tfb_tcp_do_segment == NULL) || 790 (blk->tfb_tcp_ctloutput == NULL) || 791 (strlen(blk->tfb_tcp_block_name) == 0)) { 792 /* 793 * These functions are required and you 794 * need a name. 795 */ 796 *num_names = 0; 797 return (EINVAL); 798 } 799 if (blk->tfb_tcp_timer_stop_all || 800 blk->tfb_tcp_timer_activate || 801 blk->tfb_tcp_timer_active || 802 blk->tfb_tcp_timer_stop) { 803 /* 804 * If you define one timer function you 805 * must have them all. 806 */ 807 if ((blk->tfb_tcp_timer_stop_all == NULL) || 808 (blk->tfb_tcp_timer_activate == NULL) || 809 (blk->tfb_tcp_timer_active == NULL) || 810 (blk->tfb_tcp_timer_stop == NULL)) { 811 *num_names = 0; 812 return (EINVAL); 813 } 814 } 815 816 refcount_init(&blk->tfb_refcnt, 0); 817 blk->tfb_flags = 0; 818 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 819 for (i = 0; i < *num_names; i++) { 820 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 821 if (n == NULL) { 822 error = ENOMEM; 823 goto cleanup; 824 } 825 n->tf_fb = blk; 826 827 (void)strncpy(fs.function_set_name, names[i], 828 TCP_FUNCTION_NAME_LEN_MAX); 829 fs.function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 830 rw_wlock(&tcp_function_lock); 831 if (find_tcp_functions_locked(&fs) != NULL) { 832 /* Duplicate name space not allowed */ 833 rw_wunlock(&tcp_function_lock); 834 free(n, M_TCPFUNCTIONS); 835 error = EALREADY; 836 goto cleanup; 837 } 838 (void)strncpy(n->tf_name, names[i], TCP_FUNCTION_NAME_LEN_MAX); 839 n->tf_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 840 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 841 tcp_fb_cnt++; 842 rw_wunlock(&tcp_function_lock); 843 } 844 return(0); 845 846 cleanup: 847 /* 848 * Deregister the names we just added. Because registration failed 849 * for names[i], we don't need to deregister that name. 850 */ 851 *num_names = i; 852 rw_wlock(&tcp_function_lock); 853 while (--i >= 0) { 854 TAILQ_FOREACH(n, &t_functions, tf_next) { 855 if (!strncmp(n->tf_name, names[i], 856 TCP_FUNCTION_NAME_LEN_MAX)) { 857 TAILQ_REMOVE(&t_functions, n, tf_next); 858 tcp_fb_cnt--; 859 n->tf_fb = NULL; 860 free(n, M_TCPFUNCTIONS); 861 break; 862 } 863 } 864 } 865 rw_wunlock(&tcp_function_lock); 866 return (error); 867 } 868 869 /* 870 * Register a TCP function block using the name provided in the name 871 * argument. 872 * 873 * Returns 0 on success, or an error code on failure. 874 */ 875 int 876 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 877 int wait) 878 { 879 const char *name_list[1]; 880 int num_names, rv; 881 882 num_names = 1; 883 if (name != NULL) 884 name_list[0] = name; 885 else 886 name_list[0] = blk->tfb_tcp_block_name; 887 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 888 return (rv); 889 } 890 891 /* 892 * Register a TCP function block using the name defined in 893 * blk->tfb_tcp_block_name. 894 * 895 * Returns 0 on success, or an error code on failure. 896 */ 897 int 898 register_tcp_functions(struct tcp_function_block *blk, int wait) 899 { 900 901 return (register_tcp_functions_as_name(blk, NULL, wait)); 902 } 903 904 /* 905 * Deregister all names associated with a function block. This 906 * functionally removes the function block from use within the system. 907 * 908 * When called with a true quiesce argument, mark the function block 909 * as being removed so no more stacks will use it and determine 910 * whether the removal would succeed. 911 * 912 * When called with a false quiesce argument, actually attempt the 913 * removal. 914 * 915 * When called with a force argument, attempt to switch all TCBs to 916 * use the default stack instead of returning EBUSY. 917 * 918 * Returns 0 on success (or if the removal would succeed, or an error 919 * code on failure. 920 */ 921 int 922 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 923 bool force) 924 { 925 struct tcp_function *f; 926 927 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 928 /* You can't un-register the default */ 929 return (EPERM); 930 } 931 rw_wlock(&tcp_function_lock); 932 if (blk == tcp_func_set_ptr) { 933 /* You can't free the current default */ 934 rw_wunlock(&tcp_function_lock); 935 return (EBUSY); 936 } 937 /* Mark the block so no more stacks can use it. */ 938 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 939 /* 940 * If TCBs are still attached to the stack, attempt to switch them 941 * to the default stack. 942 */ 943 if (force && blk->tfb_refcnt) { 944 struct inpcb *inp; 945 struct tcpcb *tp; 946 VNET_ITERATOR_DECL(vnet_iter); 947 948 rw_wunlock(&tcp_function_lock); 949 950 VNET_LIST_RLOCK(); 951 VNET_FOREACH(vnet_iter) { 952 CURVNET_SET(vnet_iter); 953 INP_INFO_WLOCK(&V_tcbinfo); 954 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 955 INP_WLOCK(inp); 956 if (inp->inp_flags & INP_TIMEWAIT) { 957 INP_WUNLOCK(inp); 958 continue; 959 } 960 tp = intotcpcb(inp); 961 if (tp == NULL || tp->t_fb != blk) { 962 INP_WUNLOCK(inp); 963 continue; 964 } 965 tcp_switch_back_to_default(tp); 966 INP_WUNLOCK(inp); 967 } 968 INP_INFO_WUNLOCK(&V_tcbinfo); 969 CURVNET_RESTORE(); 970 } 971 VNET_LIST_RUNLOCK(); 972 973 rw_wlock(&tcp_function_lock); 974 } 975 if (blk->tfb_refcnt) { 976 /* TCBs still attached. */ 977 rw_wunlock(&tcp_function_lock); 978 return (EBUSY); 979 } 980 if (quiesce) { 981 /* Skip removal. */ 982 rw_wunlock(&tcp_function_lock); 983 return (0); 984 } 985 /* Remove any function names that map to this function block. */ 986 while (find_tcp_fb_locked(blk, &f) != NULL) { 987 TAILQ_REMOVE(&t_functions, f, tf_next); 988 tcp_fb_cnt--; 989 f->tf_fb = NULL; 990 free(f, M_TCPFUNCTIONS); 991 } 992 rw_wunlock(&tcp_function_lock); 993 return (0); 994 } 995 996 void 997 tcp_init(void) 998 { 999 const char *tcbhash_tuneable; 1000 int hashsize; 1001 1002 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1003 1004 #ifdef TCP_HHOOK 1005 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1006 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1007 printf("%s: WARNING: unable to register helper hook\n", __func__); 1008 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1009 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1010 printf("%s: WARNING: unable to register helper hook\n", __func__); 1011 #endif 1012 hashsize = TCBHASHSIZE; 1013 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1014 if (hashsize == 0) { 1015 /* 1016 * Auto tune the hash size based on maxsockets. 1017 * A perfect hash would have a 1:1 mapping 1018 * (hashsize = maxsockets) however it's been 1019 * suggested that O(2) average is better. 1020 */ 1021 hashsize = maketcp_hashsize(maxsockets / 4); 1022 /* 1023 * Our historical default is 512, 1024 * do not autotune lower than this. 1025 */ 1026 if (hashsize < 512) 1027 hashsize = 512; 1028 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1029 printf("%s: %s auto tuned to %d\n", __func__, 1030 tcbhash_tuneable, hashsize); 1031 } 1032 /* 1033 * We require a hashsize to be a power of two. 1034 * Previously if it was not a power of two we would just reset it 1035 * back to 512, which could be a nasty surprise if you did not notice 1036 * the error message. 1037 * Instead what we do is clip it to the closest power of two lower 1038 * than the specified hash value. 1039 */ 1040 if (!powerof2(hashsize)) { 1041 int oldhashsize = hashsize; 1042 1043 hashsize = maketcp_hashsize(hashsize); 1044 /* prevent absurdly low value */ 1045 if (hashsize < 16) 1046 hashsize = 16; 1047 printf("%s: WARNING: TCB hash size not a power of 2, " 1048 "clipped from %d to %d.\n", __func__, oldhashsize, 1049 hashsize); 1050 } 1051 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1052 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1053 1054 /* 1055 * These have to be type stable for the benefit of the timers. 1056 */ 1057 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1058 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1059 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1060 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1061 1062 tcp_tw_init(); 1063 syncache_init(); 1064 tcp_hc_init(); 1065 1066 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1067 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1068 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1069 1070 tcp_fastopen_init(); 1071 1072 /* Skip initialization of globals for non-default instances. */ 1073 if (!IS_DEFAULT_VNET(curvnet)) 1074 return; 1075 1076 tcp_reass_global_init(); 1077 1078 /* XXX virtualize those bellow? */ 1079 tcp_delacktime = TCPTV_DELACK; 1080 tcp_keepinit = TCPTV_KEEP_INIT; 1081 tcp_keepidle = TCPTV_KEEP_IDLE; 1082 tcp_keepintvl = TCPTV_KEEPINTVL; 1083 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1084 tcp_msl = TCPTV_MSL; 1085 tcp_rexmit_min = TCPTV_MIN; 1086 if (tcp_rexmit_min < 1) 1087 tcp_rexmit_min = 1; 1088 tcp_persmin = TCPTV_PERSMIN; 1089 tcp_persmax = TCPTV_PERSMAX; 1090 tcp_rexmit_slop = TCPTV_CPU_VAR; 1091 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1092 tcp_tcbhashsize = hashsize; 1093 /* Setup the tcp function block list */ 1094 init_tcp_functions(); 1095 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1096 #ifdef TCP_BLACKBOX 1097 /* Initialize the TCP logging data. */ 1098 tcp_log_init(); 1099 #endif 1100 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1101 1102 if (tcp_soreceive_stream) { 1103 #ifdef INET 1104 tcp_usrreqs.pru_soreceive = soreceive_stream; 1105 #endif 1106 #ifdef INET6 1107 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1108 #endif /* INET6 */ 1109 } 1110 1111 #ifdef INET6 1112 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1113 #else /* INET6 */ 1114 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1115 #endif /* INET6 */ 1116 if (max_protohdr < TCP_MINPROTOHDR) 1117 max_protohdr = TCP_MINPROTOHDR; 1118 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1119 panic("tcp_init"); 1120 #undef TCP_MINPROTOHDR 1121 1122 ISN_LOCK_INIT(); 1123 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1124 SHUTDOWN_PRI_DEFAULT); 1125 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1126 EVENTHANDLER_PRI_ANY); 1127 #ifdef TCPPCAP 1128 tcp_pcap_init(); 1129 #endif 1130 } 1131 1132 #ifdef VIMAGE 1133 static void 1134 tcp_destroy(void *unused __unused) 1135 { 1136 int n; 1137 #ifdef TCP_HHOOK 1138 int error; 1139 #endif 1140 1141 /* 1142 * All our processes are gone, all our sockets should be cleaned 1143 * up, which means, we should be past the tcp_discardcb() calls. 1144 * Sleep to let all tcpcb timers really disappear and cleanup. 1145 */ 1146 for (;;) { 1147 INP_LIST_RLOCK(&V_tcbinfo); 1148 n = V_tcbinfo.ipi_count; 1149 INP_LIST_RUNLOCK(&V_tcbinfo); 1150 if (n == 0) 1151 break; 1152 pause("tcpdes", hz / 10); 1153 } 1154 tcp_hc_destroy(); 1155 syncache_destroy(); 1156 tcp_tw_destroy(); 1157 in_pcbinfo_destroy(&V_tcbinfo); 1158 /* tcp_discardcb() clears the sack_holes up. */ 1159 uma_zdestroy(V_sack_hole_zone); 1160 uma_zdestroy(V_tcpcb_zone); 1161 1162 /* 1163 * Cannot free the zone until all tcpcbs are released as we attach 1164 * the allocations to them. 1165 */ 1166 tcp_fastopen_destroy(); 1167 1168 #ifdef TCP_HHOOK 1169 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1170 if (error != 0) { 1171 printf("%s: WARNING: unable to deregister helper hook " 1172 "type=%d, id=%d: error %d returned\n", __func__, 1173 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1174 } 1175 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1176 if (error != 0) { 1177 printf("%s: WARNING: unable to deregister helper hook " 1178 "type=%d, id=%d: error %d returned\n", __func__, 1179 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1180 } 1181 #endif 1182 } 1183 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1184 #endif 1185 1186 void 1187 tcp_fini(void *xtp) 1188 { 1189 1190 } 1191 1192 /* 1193 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1194 * tcp_template used to store this data in mbufs, but we now recopy it out 1195 * of the tcpcb each time to conserve mbufs. 1196 */ 1197 void 1198 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1199 { 1200 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1201 1202 INP_WLOCK_ASSERT(inp); 1203 1204 #ifdef INET6 1205 if ((inp->inp_vflag & INP_IPV6) != 0) { 1206 struct ip6_hdr *ip6; 1207 1208 ip6 = (struct ip6_hdr *)ip_ptr; 1209 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1210 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1211 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1212 (IPV6_VERSION & IPV6_VERSION_MASK); 1213 ip6->ip6_nxt = IPPROTO_TCP; 1214 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1215 ip6->ip6_src = inp->in6p_laddr; 1216 ip6->ip6_dst = inp->in6p_faddr; 1217 } 1218 #endif /* INET6 */ 1219 #if defined(INET6) && defined(INET) 1220 else 1221 #endif 1222 #ifdef INET 1223 { 1224 struct ip *ip; 1225 1226 ip = (struct ip *)ip_ptr; 1227 ip->ip_v = IPVERSION; 1228 ip->ip_hl = 5; 1229 ip->ip_tos = inp->inp_ip_tos; 1230 ip->ip_len = 0; 1231 ip->ip_id = 0; 1232 ip->ip_off = 0; 1233 ip->ip_ttl = inp->inp_ip_ttl; 1234 ip->ip_sum = 0; 1235 ip->ip_p = IPPROTO_TCP; 1236 ip->ip_src = inp->inp_laddr; 1237 ip->ip_dst = inp->inp_faddr; 1238 } 1239 #endif /* INET */ 1240 th->th_sport = inp->inp_lport; 1241 th->th_dport = inp->inp_fport; 1242 th->th_seq = 0; 1243 th->th_ack = 0; 1244 th->th_x2 = 0; 1245 th->th_off = 5; 1246 th->th_flags = 0; 1247 th->th_win = 0; 1248 th->th_urp = 0; 1249 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1250 } 1251 1252 /* 1253 * Create template to be used to send tcp packets on a connection. 1254 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1255 * use for this function is in keepalives, which use tcp_respond. 1256 */ 1257 struct tcptemp * 1258 tcpip_maketemplate(struct inpcb *inp) 1259 { 1260 struct tcptemp *t; 1261 1262 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1263 if (t == NULL) 1264 return (NULL); 1265 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1266 return (t); 1267 } 1268 1269 /* 1270 * Send a single message to the TCP at address specified by 1271 * the given TCP/IP header. If m == NULL, then we make a copy 1272 * of the tcpiphdr at th and send directly to the addressed host. 1273 * This is used to force keep alive messages out using the TCP 1274 * template for a connection. If flags are given then we send 1275 * a message back to the TCP which originated the segment th, 1276 * and discard the mbuf containing it and any other attached mbufs. 1277 * 1278 * In any case the ack and sequence number of the transmitted 1279 * segment are as specified by the parameters. 1280 * 1281 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1282 */ 1283 void 1284 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1285 tcp_seq ack, tcp_seq seq, int flags) 1286 { 1287 struct tcpopt to; 1288 struct inpcb *inp; 1289 struct ip *ip; 1290 struct mbuf *optm; 1291 struct tcphdr *nth; 1292 u_char *optp; 1293 #ifdef INET6 1294 struct ip6_hdr *ip6; 1295 int isipv6; 1296 #endif /* INET6 */ 1297 int optlen, tlen, win; 1298 bool incl_opts; 1299 1300 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1301 1302 #ifdef INET6 1303 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1304 ip6 = ipgen; 1305 #endif /* INET6 */ 1306 ip = ipgen; 1307 1308 if (tp != NULL) { 1309 inp = tp->t_inpcb; 1310 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1311 INP_WLOCK_ASSERT(inp); 1312 } else 1313 inp = NULL; 1314 1315 incl_opts = false; 1316 win = 0; 1317 if (tp != NULL) { 1318 if (!(flags & TH_RST)) { 1319 win = sbspace(&inp->inp_socket->so_rcv); 1320 if (win > TCP_MAXWIN << tp->rcv_scale) 1321 win = TCP_MAXWIN << tp->rcv_scale; 1322 } 1323 if ((tp->t_flags & TF_NOOPT) == 0) 1324 incl_opts = true; 1325 } 1326 if (m == NULL) { 1327 m = m_gethdr(M_NOWAIT, MT_DATA); 1328 if (m == NULL) 1329 return; 1330 m->m_data += max_linkhdr; 1331 #ifdef INET6 1332 if (isipv6) { 1333 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1334 sizeof(struct ip6_hdr)); 1335 ip6 = mtod(m, struct ip6_hdr *); 1336 nth = (struct tcphdr *)(ip6 + 1); 1337 } else 1338 #endif /* INET6 */ 1339 { 1340 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1341 ip = mtod(m, struct ip *); 1342 nth = (struct tcphdr *)(ip + 1); 1343 } 1344 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1345 flags = TH_ACK; 1346 } else if (!M_WRITABLE(m)) { 1347 struct mbuf *n; 1348 1349 /* Can't reuse 'm', allocate a new mbuf. */ 1350 n = m_gethdr(M_NOWAIT, MT_DATA); 1351 if (n == NULL) { 1352 m_freem(m); 1353 return; 1354 } 1355 1356 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1357 m_freem(m); 1358 m_freem(n); 1359 return; 1360 } 1361 1362 n->m_data += max_linkhdr; 1363 /* m_len is set later */ 1364 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1365 #ifdef INET6 1366 if (isipv6) { 1367 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1368 sizeof(struct ip6_hdr)); 1369 ip6 = mtod(n, struct ip6_hdr *); 1370 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1371 nth = (struct tcphdr *)(ip6 + 1); 1372 } else 1373 #endif /* INET6 */ 1374 { 1375 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1376 ip = mtod(n, struct ip *); 1377 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1378 nth = (struct tcphdr *)(ip + 1); 1379 } 1380 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1381 xchg(nth->th_dport, nth->th_sport, uint16_t); 1382 th = nth; 1383 m_freem(m); 1384 m = n; 1385 } else { 1386 /* 1387 * reuse the mbuf. 1388 * XXX MRT We inherit the FIB, which is lucky. 1389 */ 1390 m_freem(m->m_next); 1391 m->m_next = NULL; 1392 m->m_data = (caddr_t)ipgen; 1393 /* m_len is set later */ 1394 #ifdef INET6 1395 if (isipv6) { 1396 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1397 nth = (struct tcphdr *)(ip6 + 1); 1398 } else 1399 #endif /* INET6 */ 1400 { 1401 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1402 nth = (struct tcphdr *)(ip + 1); 1403 } 1404 if (th != nth) { 1405 /* 1406 * this is usually a case when an extension header 1407 * exists between the IPv6 header and the 1408 * TCP header. 1409 */ 1410 nth->th_sport = th->th_sport; 1411 nth->th_dport = th->th_dport; 1412 } 1413 xchg(nth->th_dport, nth->th_sport, uint16_t); 1414 #undef xchg 1415 } 1416 tlen = 0; 1417 #ifdef INET6 1418 if (isipv6) 1419 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1420 #endif 1421 #if defined(INET) && defined(INET6) 1422 else 1423 #endif 1424 #ifdef INET 1425 tlen = sizeof (struct tcpiphdr); 1426 #endif 1427 #ifdef INVARIANTS 1428 m->m_len = 0; 1429 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1430 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1431 m, tlen, (long)M_TRAILINGSPACE(m))); 1432 #endif 1433 m->m_len = tlen; 1434 to.to_flags = 0; 1435 if (incl_opts) { 1436 /* Make sure we have room. */ 1437 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1438 m->m_next = m_get(M_NOWAIT, MT_DATA); 1439 if (m->m_next) { 1440 optp = mtod(m->m_next, u_char *); 1441 optm = m->m_next; 1442 } else 1443 incl_opts = false; 1444 } else { 1445 optp = (u_char *) (nth + 1); 1446 optm = m; 1447 } 1448 } 1449 if (incl_opts) { 1450 /* Timestamps. */ 1451 if (tp->t_flags & TF_RCVD_TSTMP) { 1452 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1453 to.to_tsecr = tp->ts_recent; 1454 to.to_flags |= TOF_TS; 1455 } 1456 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1457 /* TCP-MD5 (RFC2385). */ 1458 if (tp->t_flags & TF_SIGNATURE) 1459 to.to_flags |= TOF_SIGNATURE; 1460 #endif 1461 /* Add the options. */ 1462 tlen += optlen = tcp_addoptions(&to, optp); 1463 1464 /* Update m_len in the correct mbuf. */ 1465 optm->m_len += optlen; 1466 } else 1467 optlen = 0; 1468 #ifdef INET6 1469 if (isipv6) { 1470 ip6->ip6_flow = 0; 1471 ip6->ip6_vfc = IPV6_VERSION; 1472 ip6->ip6_nxt = IPPROTO_TCP; 1473 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1474 } 1475 #endif 1476 #if defined(INET) && defined(INET6) 1477 else 1478 #endif 1479 #ifdef INET 1480 { 1481 ip->ip_len = htons(tlen); 1482 ip->ip_ttl = V_ip_defttl; 1483 if (V_path_mtu_discovery) 1484 ip->ip_off |= htons(IP_DF); 1485 } 1486 #endif 1487 m->m_pkthdr.len = tlen; 1488 m->m_pkthdr.rcvif = NULL; 1489 #ifdef MAC 1490 if (inp != NULL) { 1491 /* 1492 * Packet is associated with a socket, so allow the 1493 * label of the response to reflect the socket label. 1494 */ 1495 INP_WLOCK_ASSERT(inp); 1496 mac_inpcb_create_mbuf(inp, m); 1497 } else { 1498 /* 1499 * Packet is not associated with a socket, so possibly 1500 * update the label in place. 1501 */ 1502 mac_netinet_tcp_reply(m); 1503 } 1504 #endif 1505 nth->th_seq = htonl(seq); 1506 nth->th_ack = htonl(ack); 1507 nth->th_x2 = 0; 1508 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1509 nth->th_flags = flags; 1510 if (tp != NULL) 1511 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1512 else 1513 nth->th_win = htons((u_short)win); 1514 nth->th_urp = 0; 1515 1516 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1517 if (to.to_flags & TOF_SIGNATURE) { 1518 if (!TCPMD5_ENABLED() || 1519 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1520 m_freem(m); 1521 return; 1522 } 1523 } 1524 #endif 1525 1526 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1527 #ifdef INET6 1528 if (isipv6) { 1529 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1530 nth->th_sum = in6_cksum_pseudo(ip6, 1531 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1532 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1533 NULL, NULL); 1534 } 1535 #endif /* INET6 */ 1536 #if defined(INET6) && defined(INET) 1537 else 1538 #endif 1539 #ifdef INET 1540 { 1541 m->m_pkthdr.csum_flags = CSUM_TCP; 1542 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1543 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1544 } 1545 #endif /* INET */ 1546 #ifdef TCPDEBUG 1547 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1548 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1549 #endif 1550 TCP_PROBE3(debug__output, tp, th, m); 1551 if (flags & TH_RST) 1552 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1553 1554 #ifdef INET6 1555 if (isipv6) { 1556 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1557 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1558 } 1559 #endif /* INET6 */ 1560 #if defined(INET) && defined(INET6) 1561 else 1562 #endif 1563 #ifdef INET 1564 { 1565 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1566 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1567 } 1568 #endif 1569 } 1570 1571 /* 1572 * Create a new TCP control block, making an 1573 * empty reassembly queue and hooking it to the argument 1574 * protocol control block. The `inp' parameter must have 1575 * come from the zone allocator set up in tcp_init(). 1576 */ 1577 struct tcpcb * 1578 tcp_newtcpcb(struct inpcb *inp) 1579 { 1580 struct tcpcb_mem *tm; 1581 struct tcpcb *tp; 1582 #ifdef INET6 1583 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1584 #endif /* INET6 */ 1585 1586 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1587 if (tm == NULL) 1588 return (NULL); 1589 tp = &tm->tcb; 1590 1591 /* Initialise cc_var struct for this tcpcb. */ 1592 tp->ccv = &tm->ccv; 1593 tp->ccv->type = IPPROTO_TCP; 1594 tp->ccv->ccvc.tcp = tp; 1595 rw_rlock(&tcp_function_lock); 1596 tp->t_fb = tcp_func_set_ptr; 1597 refcount_acquire(&tp->t_fb->tfb_refcnt); 1598 rw_runlock(&tcp_function_lock); 1599 /* 1600 * Use the current system default CC algorithm. 1601 */ 1602 CC_LIST_RLOCK(); 1603 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1604 CC_ALGO(tp) = CC_DEFAULT(); 1605 CC_LIST_RUNLOCK(); 1606 1607 if (CC_ALGO(tp)->cb_init != NULL) 1608 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1609 if (tp->t_fb->tfb_tcp_fb_fini) 1610 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1611 refcount_release(&tp->t_fb->tfb_refcnt); 1612 uma_zfree(V_tcpcb_zone, tm); 1613 return (NULL); 1614 } 1615 1616 #ifdef TCP_HHOOK 1617 tp->osd = &tm->osd; 1618 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1619 if (tp->t_fb->tfb_tcp_fb_fini) 1620 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1621 refcount_release(&tp->t_fb->tfb_refcnt); 1622 uma_zfree(V_tcpcb_zone, tm); 1623 return (NULL); 1624 } 1625 #endif 1626 1627 #ifdef VIMAGE 1628 tp->t_vnet = inp->inp_vnet; 1629 #endif 1630 tp->t_timers = &tm->tt; 1631 TAILQ_INIT(&tp->t_segq); 1632 tp->t_maxseg = 1633 #ifdef INET6 1634 isipv6 ? V_tcp_v6mssdflt : 1635 #endif /* INET6 */ 1636 V_tcp_mssdflt; 1637 1638 /* Set up our timeouts. */ 1639 callout_init(&tp->t_timers->tt_rexmt, 1); 1640 callout_init(&tp->t_timers->tt_persist, 1); 1641 callout_init(&tp->t_timers->tt_keep, 1); 1642 callout_init(&tp->t_timers->tt_2msl, 1); 1643 callout_init(&tp->t_timers->tt_delack, 1); 1644 1645 if (V_tcp_do_rfc1323) 1646 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1647 if (V_tcp_do_sack) 1648 tp->t_flags |= TF_SACK_PERMIT; 1649 TAILQ_INIT(&tp->snd_holes); 1650 /* 1651 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1652 * is called. 1653 */ 1654 in_pcbref(inp); /* Reference for tcpcb */ 1655 tp->t_inpcb = inp; 1656 1657 /* 1658 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1659 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1660 * reasonable initial retransmit time. 1661 */ 1662 tp->t_srtt = TCPTV_SRTTBASE; 1663 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1664 tp->t_rttmin = tcp_rexmit_min; 1665 tp->t_rxtcur = TCPTV_RTOBASE; 1666 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1667 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1668 tp->t_rcvtime = ticks; 1669 /* 1670 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1671 * because the socket may be bound to an IPv6 wildcard address, 1672 * which may match an IPv4-mapped IPv6 address. 1673 */ 1674 inp->inp_ip_ttl = V_ip_defttl; 1675 inp->inp_ppcb = tp; 1676 #ifdef TCPPCAP 1677 /* 1678 * Init the TCP PCAP queues. 1679 */ 1680 tcp_pcap_tcpcb_init(tp); 1681 #endif 1682 #ifdef TCP_BLACKBOX 1683 /* Initialize the per-TCPCB log data. */ 1684 tcp_log_tcpcbinit(tp); 1685 #endif 1686 if (tp->t_fb->tfb_tcp_fb_init) { 1687 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1688 } 1689 return (tp); /* XXX */ 1690 } 1691 1692 /* 1693 * Switch the congestion control algorithm back to NewReno for any active 1694 * control blocks using an algorithm which is about to go away. 1695 * This ensures the CC framework can allow the unload to proceed without leaving 1696 * any dangling pointers which would trigger a panic. 1697 * Returning non-zero would inform the CC framework that something went wrong 1698 * and it would be unsafe to allow the unload to proceed. However, there is no 1699 * way for this to occur with this implementation so we always return zero. 1700 */ 1701 int 1702 tcp_ccalgounload(struct cc_algo *unload_algo) 1703 { 1704 struct cc_algo *tmpalgo; 1705 struct inpcb *inp; 1706 struct tcpcb *tp; 1707 VNET_ITERATOR_DECL(vnet_iter); 1708 1709 /* 1710 * Check all active control blocks across all network stacks and change 1711 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1712 * requires cleanup code to be run, call it. 1713 */ 1714 VNET_LIST_RLOCK(); 1715 VNET_FOREACH(vnet_iter) { 1716 CURVNET_SET(vnet_iter); 1717 INP_INFO_WLOCK(&V_tcbinfo); 1718 /* 1719 * New connections already part way through being initialised 1720 * with the CC algo we're removing will not race with this code 1721 * because the INP_INFO_WLOCK is held during initialisation. We 1722 * therefore don't enter the loop below until the connection 1723 * list has stabilised. 1724 */ 1725 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1726 INP_WLOCK(inp); 1727 /* Important to skip tcptw structs. */ 1728 if (!(inp->inp_flags & INP_TIMEWAIT) && 1729 (tp = intotcpcb(inp)) != NULL) { 1730 /* 1731 * By holding INP_WLOCK here, we are assured 1732 * that the connection is not currently 1733 * executing inside the CC module's functions 1734 * i.e. it is safe to make the switch back to 1735 * NewReno. 1736 */ 1737 if (CC_ALGO(tp) == unload_algo) { 1738 tmpalgo = CC_ALGO(tp); 1739 if (tmpalgo->cb_destroy != NULL) 1740 tmpalgo->cb_destroy(tp->ccv); 1741 CC_DATA(tp) = NULL; 1742 /* 1743 * NewReno may allocate memory on 1744 * demand for certain stateful 1745 * configuration as needed, but is 1746 * coded to never fail on memory 1747 * allocation failure so it is a safe 1748 * fallback. 1749 */ 1750 CC_ALGO(tp) = &newreno_cc_algo; 1751 } 1752 } 1753 INP_WUNLOCK(inp); 1754 } 1755 INP_INFO_WUNLOCK(&V_tcbinfo); 1756 CURVNET_RESTORE(); 1757 } 1758 VNET_LIST_RUNLOCK(); 1759 1760 return (0); 1761 } 1762 1763 /* 1764 * Drop a TCP connection, reporting 1765 * the specified error. If connection is synchronized, 1766 * then send a RST to peer. 1767 */ 1768 struct tcpcb * 1769 tcp_drop(struct tcpcb *tp, int errno) 1770 { 1771 struct socket *so = tp->t_inpcb->inp_socket; 1772 1773 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1774 INP_WLOCK_ASSERT(tp->t_inpcb); 1775 1776 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1777 tcp_state_change(tp, TCPS_CLOSED); 1778 (void) tp->t_fb->tfb_tcp_output(tp); 1779 TCPSTAT_INC(tcps_drops); 1780 } else 1781 TCPSTAT_INC(tcps_conndrops); 1782 if (errno == ETIMEDOUT && tp->t_softerror) 1783 errno = tp->t_softerror; 1784 so->so_error = errno; 1785 return (tcp_close(tp)); 1786 } 1787 1788 void 1789 tcp_discardcb(struct tcpcb *tp) 1790 { 1791 struct inpcb *inp = tp->t_inpcb; 1792 struct socket *so = inp->inp_socket; 1793 #ifdef INET6 1794 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1795 #endif /* INET6 */ 1796 int released __unused; 1797 1798 INP_WLOCK_ASSERT(inp); 1799 1800 /* 1801 * Make sure that all of our timers are stopped before we delete the 1802 * PCB. 1803 * 1804 * If stopping a timer fails, we schedule a discard function in same 1805 * callout, and the last discard function called will take care of 1806 * deleting the tcpcb. 1807 */ 1808 tp->t_timers->tt_draincnt = 0; 1809 tcp_timer_stop(tp, TT_REXMT); 1810 tcp_timer_stop(tp, TT_PERSIST); 1811 tcp_timer_stop(tp, TT_KEEP); 1812 tcp_timer_stop(tp, TT_2MSL); 1813 tcp_timer_stop(tp, TT_DELACK); 1814 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1815 /* 1816 * Call the stop-all function of the methods, 1817 * this function should call the tcp_timer_stop() 1818 * method with each of the function specific timeouts. 1819 * That stop will be called via the tfb_tcp_timer_stop() 1820 * which should use the async drain function of the 1821 * callout system (see tcp_var.h). 1822 */ 1823 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1824 } 1825 1826 /* 1827 * If we got enough samples through the srtt filter, 1828 * save the rtt and rttvar in the routing entry. 1829 * 'Enough' is arbitrarily defined as 4 rtt samples. 1830 * 4 samples is enough for the srtt filter to converge 1831 * to within enough % of the correct value; fewer samples 1832 * and we could save a bogus rtt. The danger is not high 1833 * as tcp quickly recovers from everything. 1834 * XXX: Works very well but needs some more statistics! 1835 */ 1836 if (tp->t_rttupdated >= 4) { 1837 struct hc_metrics_lite metrics; 1838 uint32_t ssthresh; 1839 1840 bzero(&metrics, sizeof(metrics)); 1841 /* 1842 * Update the ssthresh always when the conditions below 1843 * are satisfied. This gives us better new start value 1844 * for the congestion avoidance for new connections. 1845 * ssthresh is only set if packet loss occurred on a session. 1846 * 1847 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1848 * being torn down. Ideally this code would not use 'so'. 1849 */ 1850 ssthresh = tp->snd_ssthresh; 1851 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1852 /* 1853 * convert the limit from user data bytes to 1854 * packets then to packet data bytes. 1855 */ 1856 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1857 if (ssthresh < 2) 1858 ssthresh = 2; 1859 ssthresh *= (tp->t_maxseg + 1860 #ifdef INET6 1861 (isipv6 ? sizeof (struct ip6_hdr) + 1862 sizeof (struct tcphdr) : 1863 #endif 1864 sizeof (struct tcpiphdr) 1865 #ifdef INET6 1866 ) 1867 #endif 1868 ); 1869 } else 1870 ssthresh = 0; 1871 metrics.rmx_ssthresh = ssthresh; 1872 1873 metrics.rmx_rtt = tp->t_srtt; 1874 metrics.rmx_rttvar = tp->t_rttvar; 1875 metrics.rmx_cwnd = tp->snd_cwnd; 1876 metrics.rmx_sendpipe = 0; 1877 metrics.rmx_recvpipe = 0; 1878 1879 tcp_hc_update(&inp->inp_inc, &metrics); 1880 } 1881 1882 /* free the reassembly queue, if any */ 1883 tcp_reass_flush(tp); 1884 1885 #ifdef TCP_OFFLOAD 1886 /* Disconnect offload device, if any. */ 1887 if (tp->t_flags & TF_TOE) 1888 tcp_offload_detach(tp); 1889 #endif 1890 1891 tcp_free_sackholes(tp); 1892 1893 #ifdef TCPPCAP 1894 /* Free the TCP PCAP queues. */ 1895 tcp_pcap_drain(&(tp->t_inpkts)); 1896 tcp_pcap_drain(&(tp->t_outpkts)); 1897 #endif 1898 1899 /* Allow the CC algorithm to clean up after itself. */ 1900 if (CC_ALGO(tp)->cb_destroy != NULL) 1901 CC_ALGO(tp)->cb_destroy(tp->ccv); 1902 CC_DATA(tp) = NULL; 1903 1904 #ifdef TCP_HHOOK 1905 khelp_destroy_osd(tp->osd); 1906 #endif 1907 1908 CC_ALGO(tp) = NULL; 1909 inp->inp_ppcb = NULL; 1910 if (tp->t_timers->tt_draincnt == 0) { 1911 /* We own the last reference on tcpcb, let's free it. */ 1912 #ifdef TCP_BLACKBOX 1913 tcp_log_tcpcbfini(tp); 1914 #endif 1915 TCPSTATES_DEC(tp->t_state); 1916 if (tp->t_fb->tfb_tcp_fb_fini) 1917 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1918 refcount_release(&tp->t_fb->tfb_refcnt); 1919 tp->t_inpcb = NULL; 1920 uma_zfree(V_tcpcb_zone, tp); 1921 released = in_pcbrele_wlocked(inp); 1922 KASSERT(!released, ("%s: inp %p should not have been released " 1923 "here", __func__, inp)); 1924 } 1925 } 1926 1927 void 1928 tcp_timer_discard(void *ptp) 1929 { 1930 struct inpcb *inp; 1931 struct tcpcb *tp; 1932 struct epoch_tracker et; 1933 1934 tp = (struct tcpcb *)ptp; 1935 CURVNET_SET(tp->t_vnet); 1936 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 1937 inp = tp->t_inpcb; 1938 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1939 __func__, tp)); 1940 INP_WLOCK(inp); 1941 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1942 ("%s: tcpcb has to be stopped here", __func__)); 1943 tp->t_timers->tt_draincnt--; 1944 if (tp->t_timers->tt_draincnt == 0) { 1945 /* We own the last reference on this tcpcb, let's free it. */ 1946 #ifdef TCP_BLACKBOX 1947 tcp_log_tcpcbfini(tp); 1948 #endif 1949 TCPSTATES_DEC(tp->t_state); 1950 if (tp->t_fb->tfb_tcp_fb_fini) 1951 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1952 refcount_release(&tp->t_fb->tfb_refcnt); 1953 tp->t_inpcb = NULL; 1954 uma_zfree(V_tcpcb_zone, tp); 1955 if (in_pcbrele_wlocked(inp)) { 1956 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1957 CURVNET_RESTORE(); 1958 return; 1959 } 1960 } 1961 INP_WUNLOCK(inp); 1962 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1963 CURVNET_RESTORE(); 1964 } 1965 1966 /* 1967 * Attempt to close a TCP control block, marking it as dropped, and freeing 1968 * the socket if we hold the only reference. 1969 */ 1970 struct tcpcb * 1971 tcp_close(struct tcpcb *tp) 1972 { 1973 struct inpcb *inp = tp->t_inpcb; 1974 struct socket *so; 1975 1976 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1977 INP_WLOCK_ASSERT(inp); 1978 1979 #ifdef TCP_OFFLOAD 1980 if (tp->t_state == TCPS_LISTEN) 1981 tcp_offload_listen_stop(tp); 1982 #endif 1983 /* 1984 * This releases the TFO pending counter resource for TFO listen 1985 * sockets as well as passively-created TFO sockets that transition 1986 * from SYN_RECEIVED to CLOSED. 1987 */ 1988 if (tp->t_tfo_pending) { 1989 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1990 tp->t_tfo_pending = NULL; 1991 } 1992 in_pcbdrop(inp); 1993 TCPSTAT_INC(tcps_closed); 1994 if (tp->t_state != TCPS_CLOSED) 1995 tcp_state_change(tp, TCPS_CLOSED); 1996 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1997 so = inp->inp_socket; 1998 soisdisconnected(so); 1999 if (inp->inp_flags & INP_SOCKREF) { 2000 KASSERT(so->so_state & SS_PROTOREF, 2001 ("tcp_close: !SS_PROTOREF")); 2002 inp->inp_flags &= ~INP_SOCKREF; 2003 INP_WUNLOCK(inp); 2004 SOCK_LOCK(so); 2005 so->so_state &= ~SS_PROTOREF; 2006 sofree(so); 2007 return (NULL); 2008 } 2009 return (tp); 2010 } 2011 2012 void 2013 tcp_drain(void) 2014 { 2015 VNET_ITERATOR_DECL(vnet_iter); 2016 2017 if (!do_tcpdrain) 2018 return; 2019 2020 VNET_LIST_RLOCK_NOSLEEP(); 2021 VNET_FOREACH(vnet_iter) { 2022 CURVNET_SET(vnet_iter); 2023 struct inpcb *inpb; 2024 struct tcpcb *tcpb; 2025 2026 /* 2027 * Walk the tcpbs, if existing, and flush the reassembly queue, 2028 * if there is one... 2029 * XXX: The "Net/3" implementation doesn't imply that the TCP 2030 * reassembly queue should be flushed, but in a situation 2031 * where we're really low on mbufs, this is potentially 2032 * useful. 2033 */ 2034 INP_INFO_WLOCK(&V_tcbinfo); 2035 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2036 INP_WLOCK(inpb); 2037 if (inpb->inp_flags & INP_TIMEWAIT) { 2038 INP_WUNLOCK(inpb); 2039 continue; 2040 } 2041 if ((tcpb = intotcpcb(inpb)) != NULL) { 2042 tcp_reass_flush(tcpb); 2043 tcp_clean_sackreport(tcpb); 2044 #ifdef TCP_BLACKBOX 2045 tcp_log_drain(tcpb); 2046 #endif 2047 #ifdef TCPPCAP 2048 if (tcp_pcap_aggressive_free) { 2049 /* Free the TCP PCAP queues. */ 2050 tcp_pcap_drain(&(tcpb->t_inpkts)); 2051 tcp_pcap_drain(&(tcpb->t_outpkts)); 2052 } 2053 #endif 2054 } 2055 INP_WUNLOCK(inpb); 2056 } 2057 INP_INFO_WUNLOCK(&V_tcbinfo); 2058 CURVNET_RESTORE(); 2059 } 2060 VNET_LIST_RUNLOCK_NOSLEEP(); 2061 } 2062 2063 /* 2064 * Notify a tcp user of an asynchronous error; 2065 * store error as soft error, but wake up user 2066 * (for now, won't do anything until can select for soft error). 2067 * 2068 * Do not wake up user since there currently is no mechanism for 2069 * reporting soft errors (yet - a kqueue filter may be added). 2070 */ 2071 static struct inpcb * 2072 tcp_notify(struct inpcb *inp, int error) 2073 { 2074 struct tcpcb *tp; 2075 2076 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2077 INP_WLOCK_ASSERT(inp); 2078 2079 if ((inp->inp_flags & INP_TIMEWAIT) || 2080 (inp->inp_flags & INP_DROPPED)) 2081 return (inp); 2082 2083 tp = intotcpcb(inp); 2084 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2085 2086 /* 2087 * Ignore some errors if we are hooked up. 2088 * If connection hasn't completed, has retransmitted several times, 2089 * and receives a second error, give up now. This is better 2090 * than waiting a long time to establish a connection that 2091 * can never complete. 2092 */ 2093 if (tp->t_state == TCPS_ESTABLISHED && 2094 (error == EHOSTUNREACH || error == ENETUNREACH || 2095 error == EHOSTDOWN)) { 2096 if (inp->inp_route.ro_rt) { 2097 RTFREE(inp->inp_route.ro_rt); 2098 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2099 } 2100 return (inp); 2101 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2102 tp->t_softerror) { 2103 tp = tcp_drop(tp, error); 2104 if (tp != NULL) 2105 return (inp); 2106 else 2107 return (NULL); 2108 } else { 2109 tp->t_softerror = error; 2110 return (inp); 2111 } 2112 #if 0 2113 wakeup( &so->so_timeo); 2114 sorwakeup(so); 2115 sowwakeup(so); 2116 #endif 2117 } 2118 2119 static int 2120 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2121 { 2122 int error, i, m, n, pcb_count; 2123 struct inpcb *inp, **inp_list; 2124 inp_gen_t gencnt; 2125 struct xinpgen xig; 2126 struct epoch_tracker et; 2127 2128 /* 2129 * The process of preparing the TCB list is too time-consuming and 2130 * resource-intensive to repeat twice on every request. 2131 */ 2132 if (req->oldptr == NULL) { 2133 n = V_tcbinfo.ipi_count + 2134 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2135 n += imax(n / 8, 10); 2136 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2137 return (0); 2138 } 2139 2140 if (req->newptr != NULL) 2141 return (EPERM); 2142 2143 /* 2144 * OK, now we're committed to doing something. 2145 */ 2146 INP_LIST_RLOCK(&V_tcbinfo); 2147 gencnt = V_tcbinfo.ipi_gencnt; 2148 n = V_tcbinfo.ipi_count; 2149 INP_LIST_RUNLOCK(&V_tcbinfo); 2150 2151 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2152 2153 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2154 + (n + m) * sizeof(struct xtcpcb)); 2155 if (error != 0) 2156 return (error); 2157 2158 bzero(&xig, sizeof(xig)); 2159 xig.xig_len = sizeof xig; 2160 xig.xig_count = n + m; 2161 xig.xig_gen = gencnt; 2162 xig.xig_sogen = so_gencnt; 2163 error = SYSCTL_OUT(req, &xig, sizeof xig); 2164 if (error) 2165 return (error); 2166 2167 error = syncache_pcblist(req, m, &pcb_count); 2168 if (error) 2169 return (error); 2170 2171 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2172 2173 INP_INFO_WLOCK(&V_tcbinfo); 2174 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2175 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) { 2176 INP_WLOCK(inp); 2177 if (inp->inp_gencnt <= gencnt) { 2178 /* 2179 * XXX: This use of cr_cansee(), introduced with 2180 * TCP state changes, is not quite right, but for 2181 * now, better than nothing. 2182 */ 2183 if (inp->inp_flags & INP_TIMEWAIT) { 2184 if (intotw(inp) != NULL) 2185 error = cr_cansee(req->td->td_ucred, 2186 intotw(inp)->tw_cred); 2187 else 2188 error = EINVAL; /* Skip this inp. */ 2189 } else 2190 error = cr_canseeinpcb(req->td->td_ucred, inp); 2191 if (error == 0) { 2192 in_pcbref(inp); 2193 inp_list[i++] = inp; 2194 } 2195 } 2196 INP_WUNLOCK(inp); 2197 } 2198 INP_INFO_WUNLOCK(&V_tcbinfo); 2199 n = i; 2200 2201 error = 0; 2202 for (i = 0; i < n; i++) { 2203 inp = inp_list[i]; 2204 INP_RLOCK(inp); 2205 if (inp->inp_gencnt <= gencnt) { 2206 struct xtcpcb xt; 2207 2208 tcp_inptoxtp(inp, &xt); 2209 INP_RUNLOCK(inp); 2210 error = SYSCTL_OUT(req, &xt, sizeof xt); 2211 } else 2212 INP_RUNLOCK(inp); 2213 } 2214 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2215 for (i = 0; i < n; i++) { 2216 inp = inp_list[i]; 2217 INP_RLOCK(inp); 2218 if (!in_pcbrele_rlocked(inp)) 2219 INP_RUNLOCK(inp); 2220 } 2221 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2222 2223 if (!error) { 2224 /* 2225 * Give the user an updated idea of our state. 2226 * If the generation differs from what we told 2227 * her before, she knows that something happened 2228 * while we were processing this request, and it 2229 * might be necessary to retry. 2230 */ 2231 INP_LIST_RLOCK(&V_tcbinfo); 2232 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2233 xig.xig_sogen = so_gencnt; 2234 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2235 INP_LIST_RUNLOCK(&V_tcbinfo); 2236 error = SYSCTL_OUT(req, &xig, sizeof xig); 2237 } 2238 free(inp_list, M_TEMP); 2239 return (error); 2240 } 2241 2242 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2243 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2244 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2245 2246 #ifdef INET 2247 static int 2248 tcp_getcred(SYSCTL_HANDLER_ARGS) 2249 { 2250 struct xucred xuc; 2251 struct sockaddr_in addrs[2]; 2252 struct inpcb *inp; 2253 int error; 2254 2255 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2256 if (error) 2257 return (error); 2258 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2259 if (error) 2260 return (error); 2261 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2262 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2263 if (inp != NULL) { 2264 if (inp->inp_socket == NULL) 2265 error = ENOENT; 2266 if (error == 0) 2267 error = cr_canseeinpcb(req->td->td_ucred, inp); 2268 if (error == 0) 2269 cru2x(inp->inp_cred, &xuc); 2270 INP_RUNLOCK(inp); 2271 } else 2272 error = ENOENT; 2273 if (error == 0) 2274 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2275 return (error); 2276 } 2277 2278 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2279 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2280 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2281 #endif /* INET */ 2282 2283 #ifdef INET6 2284 static int 2285 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2286 { 2287 struct xucred xuc; 2288 struct sockaddr_in6 addrs[2]; 2289 struct inpcb *inp; 2290 int error; 2291 #ifdef INET 2292 int mapped = 0; 2293 #endif 2294 2295 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2296 if (error) 2297 return (error); 2298 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2299 if (error) 2300 return (error); 2301 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2302 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2303 return (error); 2304 } 2305 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2306 #ifdef INET 2307 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2308 mapped = 1; 2309 else 2310 #endif 2311 return (EINVAL); 2312 } 2313 2314 #ifdef INET 2315 if (mapped == 1) 2316 inp = in_pcblookup(&V_tcbinfo, 2317 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2318 addrs[1].sin6_port, 2319 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2320 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2321 else 2322 #endif 2323 inp = in6_pcblookup(&V_tcbinfo, 2324 &addrs[1].sin6_addr, addrs[1].sin6_port, 2325 &addrs[0].sin6_addr, addrs[0].sin6_port, 2326 INPLOOKUP_RLOCKPCB, NULL); 2327 if (inp != NULL) { 2328 if (inp->inp_socket == NULL) 2329 error = ENOENT; 2330 if (error == 0) 2331 error = cr_canseeinpcb(req->td->td_ucred, inp); 2332 if (error == 0) 2333 cru2x(inp->inp_cred, &xuc); 2334 INP_RUNLOCK(inp); 2335 } else 2336 error = ENOENT; 2337 if (error == 0) 2338 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2339 return (error); 2340 } 2341 2342 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2343 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2344 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2345 #endif /* INET6 */ 2346 2347 2348 #ifdef INET 2349 void 2350 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2351 { 2352 struct ip *ip = vip; 2353 struct tcphdr *th; 2354 struct in_addr faddr; 2355 struct inpcb *inp; 2356 struct tcpcb *tp; 2357 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2358 struct icmp *icp; 2359 struct in_conninfo inc; 2360 struct epoch_tracker et; 2361 tcp_seq icmp_tcp_seq; 2362 int mtu; 2363 2364 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2365 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2366 return; 2367 2368 if (cmd == PRC_MSGSIZE) 2369 notify = tcp_mtudisc_notify; 2370 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2371 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2372 cmd == PRC_TIMXCEED_INTRANS) && ip) 2373 notify = tcp_drop_syn_sent; 2374 2375 /* 2376 * Hostdead is ugly because it goes linearly through all PCBs. 2377 * XXX: We never get this from ICMP, otherwise it makes an 2378 * excellent DoS attack on machines with many connections. 2379 */ 2380 else if (cmd == PRC_HOSTDEAD) 2381 ip = NULL; 2382 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2383 return; 2384 2385 if (ip == NULL) { 2386 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2387 return; 2388 } 2389 2390 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2391 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2392 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2393 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2394 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2395 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2396 /* signal EHOSTDOWN, as it flushes the cached route */ 2397 inp = (*notify)(inp, EHOSTDOWN); 2398 goto out; 2399 } 2400 icmp_tcp_seq = th->th_seq; 2401 if (inp != NULL) { 2402 if (!(inp->inp_flags & INP_TIMEWAIT) && 2403 !(inp->inp_flags & INP_DROPPED) && 2404 !(inp->inp_socket == NULL)) { 2405 tp = intotcpcb(inp); 2406 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2407 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2408 if (cmd == PRC_MSGSIZE) { 2409 /* 2410 * MTU discovery: 2411 * If we got a needfrag set the MTU 2412 * in the route to the suggested new 2413 * value (if given) and then notify. 2414 */ 2415 mtu = ntohs(icp->icmp_nextmtu); 2416 /* 2417 * If no alternative MTU was 2418 * proposed, try the next smaller 2419 * one. 2420 */ 2421 if (!mtu) 2422 mtu = ip_next_mtu( 2423 ntohs(ip->ip_len), 1); 2424 if (mtu < V_tcp_minmss + 2425 sizeof(struct tcpiphdr)) 2426 mtu = V_tcp_minmss + 2427 sizeof(struct tcpiphdr); 2428 /* 2429 * Only process the offered MTU if it 2430 * is smaller than the current one. 2431 */ 2432 if (mtu < tp->t_maxseg + 2433 sizeof(struct tcpiphdr)) { 2434 bzero(&inc, sizeof(inc)); 2435 inc.inc_faddr = faddr; 2436 inc.inc_fibnum = 2437 inp->inp_inc.inc_fibnum; 2438 tcp_hc_updatemtu(&inc, mtu); 2439 tcp_mtudisc(inp, mtu); 2440 } 2441 } else 2442 inp = (*notify)(inp, 2443 inetctlerrmap[cmd]); 2444 } 2445 } 2446 } else { 2447 bzero(&inc, sizeof(inc)); 2448 inc.inc_fport = th->th_dport; 2449 inc.inc_lport = th->th_sport; 2450 inc.inc_faddr = faddr; 2451 inc.inc_laddr = ip->ip_src; 2452 syncache_unreach(&inc, icmp_tcp_seq); 2453 } 2454 out: 2455 if (inp != NULL) 2456 INP_WUNLOCK(inp); 2457 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2458 } 2459 #endif /* INET */ 2460 2461 #ifdef INET6 2462 void 2463 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2464 { 2465 struct in6_addr *dst; 2466 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2467 struct ip6_hdr *ip6; 2468 struct mbuf *m; 2469 struct inpcb *inp; 2470 struct tcpcb *tp; 2471 struct icmp6_hdr *icmp6; 2472 struct ip6ctlparam *ip6cp = NULL; 2473 const struct sockaddr_in6 *sa6_src = NULL; 2474 struct in_conninfo inc; 2475 struct epoch_tracker et; 2476 struct tcp_ports { 2477 uint16_t th_sport; 2478 uint16_t th_dport; 2479 } t_ports; 2480 tcp_seq icmp_tcp_seq; 2481 unsigned int mtu; 2482 unsigned int off; 2483 2484 if (sa->sa_family != AF_INET6 || 2485 sa->sa_len != sizeof(struct sockaddr_in6)) 2486 return; 2487 2488 /* if the parameter is from icmp6, decode it. */ 2489 if (d != NULL) { 2490 ip6cp = (struct ip6ctlparam *)d; 2491 icmp6 = ip6cp->ip6c_icmp6; 2492 m = ip6cp->ip6c_m; 2493 ip6 = ip6cp->ip6c_ip6; 2494 off = ip6cp->ip6c_off; 2495 sa6_src = ip6cp->ip6c_src; 2496 dst = ip6cp->ip6c_finaldst; 2497 } else { 2498 m = NULL; 2499 ip6 = NULL; 2500 off = 0; /* fool gcc */ 2501 sa6_src = &sa6_any; 2502 dst = NULL; 2503 } 2504 2505 if (cmd == PRC_MSGSIZE) 2506 notify = tcp_mtudisc_notify; 2507 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2508 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2509 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2510 notify = tcp_drop_syn_sent; 2511 2512 /* 2513 * Hostdead is ugly because it goes linearly through all PCBs. 2514 * XXX: We never get this from ICMP, otherwise it makes an 2515 * excellent DoS attack on machines with many connections. 2516 */ 2517 else if (cmd == PRC_HOSTDEAD) 2518 ip6 = NULL; 2519 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2520 return; 2521 2522 if (ip6 == NULL) { 2523 in6_pcbnotify(&V_tcbinfo, sa, 0, 2524 (const struct sockaddr *)sa6_src, 2525 0, cmd, NULL, notify); 2526 return; 2527 } 2528 2529 /* Check if we can safely get the ports from the tcp hdr */ 2530 if (m == NULL || 2531 (m->m_pkthdr.len < 2532 (int32_t) (off + sizeof(struct tcp_ports)))) { 2533 return; 2534 } 2535 bzero(&t_ports, sizeof(struct tcp_ports)); 2536 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2537 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2538 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2539 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2540 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2541 /* signal EHOSTDOWN, as it flushes the cached route */ 2542 inp = (*notify)(inp, EHOSTDOWN); 2543 goto out; 2544 } 2545 off += sizeof(struct tcp_ports); 2546 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2547 goto out; 2548 } 2549 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2550 if (inp != NULL) { 2551 if (!(inp->inp_flags & INP_TIMEWAIT) && 2552 !(inp->inp_flags & INP_DROPPED) && 2553 !(inp->inp_socket == NULL)) { 2554 tp = intotcpcb(inp); 2555 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2556 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2557 if (cmd == PRC_MSGSIZE) { 2558 /* 2559 * MTU discovery: 2560 * If we got a needfrag set the MTU 2561 * in the route to the suggested new 2562 * value (if given) and then notify. 2563 */ 2564 mtu = ntohl(icmp6->icmp6_mtu); 2565 /* 2566 * If no alternative MTU was 2567 * proposed, or the proposed 2568 * MTU was too small, set to 2569 * the min. 2570 */ 2571 if (mtu < IPV6_MMTU) 2572 mtu = IPV6_MMTU - 8; 2573 bzero(&inc, sizeof(inc)); 2574 inc.inc_fibnum = M_GETFIB(m); 2575 inc.inc_flags |= INC_ISIPV6; 2576 inc.inc6_faddr = *dst; 2577 if (in6_setscope(&inc.inc6_faddr, 2578 m->m_pkthdr.rcvif, NULL)) 2579 goto out; 2580 /* 2581 * Only process the offered MTU if it 2582 * is smaller than the current one. 2583 */ 2584 if (mtu < tp->t_maxseg + 2585 sizeof (struct tcphdr) + 2586 sizeof (struct ip6_hdr)) { 2587 tcp_hc_updatemtu(&inc, mtu); 2588 tcp_mtudisc(inp, mtu); 2589 ICMP6STAT_INC(icp6s_pmtuchg); 2590 } 2591 } else 2592 inp = (*notify)(inp, 2593 inet6ctlerrmap[cmd]); 2594 } 2595 } 2596 } else { 2597 bzero(&inc, sizeof(inc)); 2598 inc.inc_fibnum = M_GETFIB(m); 2599 inc.inc_flags |= INC_ISIPV6; 2600 inc.inc_fport = t_ports.th_dport; 2601 inc.inc_lport = t_ports.th_sport; 2602 inc.inc6_faddr = *dst; 2603 inc.inc6_laddr = ip6->ip6_src; 2604 syncache_unreach(&inc, icmp_tcp_seq); 2605 } 2606 out: 2607 if (inp != NULL) 2608 INP_WUNLOCK(inp); 2609 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2610 } 2611 #endif /* INET6 */ 2612 2613 static uint32_t 2614 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2615 { 2616 MD5_CTX ctx; 2617 uint32_t hash[4]; 2618 2619 MD5Init(&ctx); 2620 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2621 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2622 switch (inc->inc_flags & INC_ISIPV6) { 2623 #ifdef INET 2624 case 0: 2625 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2626 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2627 break; 2628 #endif 2629 #ifdef INET6 2630 case INC_ISIPV6: 2631 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2632 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2633 break; 2634 #endif 2635 } 2636 MD5Update(&ctx, key, len); 2637 MD5Final((unsigned char *)hash, &ctx); 2638 2639 return (hash[0]); 2640 } 2641 2642 uint32_t 2643 tcp_new_ts_offset(struct in_conninfo *inc) 2644 { 2645 return (tcp_keyed_hash(inc, V_ts_offset_secret, 2646 sizeof(V_ts_offset_secret))); 2647 } 2648 2649 /* 2650 * Following is where TCP initial sequence number generation occurs. 2651 * 2652 * There are two places where we must use initial sequence numbers: 2653 * 1. In SYN-ACK packets. 2654 * 2. In SYN packets. 2655 * 2656 * All ISNs for SYN-ACK packets are generated by the syncache. See 2657 * tcp_syncache.c for details. 2658 * 2659 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2660 * depends on this property. In addition, these ISNs should be 2661 * unguessable so as to prevent connection hijacking. To satisfy 2662 * the requirements of this situation, the algorithm outlined in 2663 * RFC 1948 is used, with only small modifications. 2664 * 2665 * Implementation details: 2666 * 2667 * Time is based off the system timer, and is corrected so that it 2668 * increases by one megabyte per second. This allows for proper 2669 * recycling on high speed LANs while still leaving over an hour 2670 * before rollover. 2671 * 2672 * As reading the *exact* system time is too expensive to be done 2673 * whenever setting up a TCP connection, we increment the time 2674 * offset in two ways. First, a small random positive increment 2675 * is added to isn_offset for each connection that is set up. 2676 * Second, the function tcp_isn_tick fires once per clock tick 2677 * and increments isn_offset as necessary so that sequence numbers 2678 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2679 * random positive increments serve only to ensure that the same 2680 * exact sequence number is never sent out twice (as could otherwise 2681 * happen when a port is recycled in less than the system tick 2682 * interval.) 2683 * 2684 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2685 * between seeding of isn_secret. This is normally set to zero, 2686 * as reseeding should not be necessary. 2687 * 2688 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2689 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2690 * general, this means holding an exclusive (write) lock. 2691 */ 2692 2693 #define ISN_BYTES_PER_SECOND 1048576 2694 #define ISN_STATIC_INCREMENT 4096 2695 #define ISN_RANDOM_INCREMENT (4096 - 1) 2696 #define ISN_SECRET_LENGTH 32 2697 2698 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2699 VNET_DEFINE_STATIC(int, isn_last); 2700 VNET_DEFINE_STATIC(int, isn_last_reseed); 2701 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2702 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2703 2704 #define V_isn_secret VNET(isn_secret) 2705 #define V_isn_last VNET(isn_last) 2706 #define V_isn_last_reseed VNET(isn_last_reseed) 2707 #define V_isn_offset VNET(isn_offset) 2708 #define V_isn_offset_old VNET(isn_offset_old) 2709 2710 tcp_seq 2711 tcp_new_isn(struct in_conninfo *inc) 2712 { 2713 tcp_seq new_isn; 2714 u_int32_t projected_offset; 2715 2716 ISN_LOCK(); 2717 /* Seed if this is the first use, reseed if requested. */ 2718 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2719 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2720 < (u_int)ticks))) { 2721 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2722 V_isn_last_reseed = ticks; 2723 } 2724 2725 /* Compute the md5 hash and return the ISN. */ 2726 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2727 sizeof(V_isn_secret)); 2728 V_isn_offset += ISN_STATIC_INCREMENT + 2729 (arc4random() & ISN_RANDOM_INCREMENT); 2730 if (ticks != V_isn_last) { 2731 projected_offset = V_isn_offset_old + 2732 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2733 if (SEQ_GT(projected_offset, V_isn_offset)) 2734 V_isn_offset = projected_offset; 2735 V_isn_offset_old = V_isn_offset; 2736 V_isn_last = ticks; 2737 } 2738 new_isn += V_isn_offset; 2739 ISN_UNLOCK(); 2740 return (new_isn); 2741 } 2742 2743 /* 2744 * When a specific ICMP unreachable message is received and the 2745 * connection state is SYN-SENT, drop the connection. This behavior 2746 * is controlled by the icmp_may_rst sysctl. 2747 */ 2748 struct inpcb * 2749 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2750 { 2751 struct tcpcb *tp; 2752 2753 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2754 INP_WLOCK_ASSERT(inp); 2755 2756 if ((inp->inp_flags & INP_TIMEWAIT) || 2757 (inp->inp_flags & INP_DROPPED)) 2758 return (inp); 2759 2760 tp = intotcpcb(inp); 2761 if (tp->t_state != TCPS_SYN_SENT) 2762 return (inp); 2763 2764 if (IS_FASTOPEN(tp->t_flags)) 2765 tcp_fastopen_disable_path(tp); 2766 2767 tp = tcp_drop(tp, errno); 2768 if (tp != NULL) 2769 return (inp); 2770 else 2771 return (NULL); 2772 } 2773 2774 /* 2775 * When `need fragmentation' ICMP is received, update our idea of the MSS 2776 * based on the new value. Also nudge TCP to send something, since we 2777 * know the packet we just sent was dropped. 2778 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2779 */ 2780 static struct inpcb * 2781 tcp_mtudisc_notify(struct inpcb *inp, int error) 2782 { 2783 2784 tcp_mtudisc(inp, -1); 2785 return (inp); 2786 } 2787 2788 static void 2789 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2790 { 2791 struct tcpcb *tp; 2792 struct socket *so; 2793 2794 INP_WLOCK_ASSERT(inp); 2795 if ((inp->inp_flags & INP_TIMEWAIT) || 2796 (inp->inp_flags & INP_DROPPED)) 2797 return; 2798 2799 tp = intotcpcb(inp); 2800 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2801 2802 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2803 2804 so = inp->inp_socket; 2805 SOCKBUF_LOCK(&so->so_snd); 2806 /* If the mss is larger than the socket buffer, decrease the mss. */ 2807 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2808 tp->t_maxseg = so->so_snd.sb_hiwat; 2809 SOCKBUF_UNLOCK(&so->so_snd); 2810 2811 TCPSTAT_INC(tcps_mturesent); 2812 tp->t_rtttime = 0; 2813 tp->snd_nxt = tp->snd_una; 2814 tcp_free_sackholes(tp); 2815 tp->snd_recover = tp->snd_max; 2816 if (tp->t_flags & TF_SACK_PERMIT) 2817 EXIT_FASTRECOVERY(tp->t_flags); 2818 tp->t_fb->tfb_tcp_output(tp); 2819 } 2820 2821 #ifdef INET 2822 /* 2823 * Look-up the routing entry to the peer of this inpcb. If no route 2824 * is found and it cannot be allocated, then return 0. This routine 2825 * is called by TCP routines that access the rmx structure and by 2826 * tcp_mss_update to get the peer/interface MTU. 2827 */ 2828 uint32_t 2829 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2830 { 2831 struct nhop4_extended nh4; 2832 struct ifnet *ifp; 2833 uint32_t maxmtu = 0; 2834 2835 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2836 2837 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2838 2839 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2840 NHR_REF, 0, &nh4) != 0) 2841 return (0); 2842 2843 ifp = nh4.nh_ifp; 2844 maxmtu = nh4.nh_mtu; 2845 2846 /* Report additional interface capabilities. */ 2847 if (cap != NULL) { 2848 if (ifp->if_capenable & IFCAP_TSO4 && 2849 ifp->if_hwassist & CSUM_TSO) { 2850 cap->ifcap |= CSUM_TSO; 2851 cap->tsomax = ifp->if_hw_tsomax; 2852 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2853 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2854 } 2855 } 2856 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2857 } 2858 return (maxmtu); 2859 } 2860 #endif /* INET */ 2861 2862 #ifdef INET6 2863 uint32_t 2864 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2865 { 2866 struct nhop6_extended nh6; 2867 struct in6_addr dst6; 2868 uint32_t scopeid; 2869 struct ifnet *ifp; 2870 uint32_t maxmtu = 0; 2871 2872 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2873 2874 if (inc->inc_flags & INC_IPV6MINMTU) 2875 return (IPV6_MMTU); 2876 2877 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2878 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2879 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2880 0, &nh6) != 0) 2881 return (0); 2882 2883 ifp = nh6.nh_ifp; 2884 maxmtu = nh6.nh_mtu; 2885 2886 /* Report additional interface capabilities. */ 2887 if (cap != NULL) { 2888 if (ifp->if_capenable & IFCAP_TSO6 && 2889 ifp->if_hwassist & CSUM_TSO) { 2890 cap->ifcap |= CSUM_TSO; 2891 cap->tsomax = ifp->if_hw_tsomax; 2892 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2893 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2894 } 2895 } 2896 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2897 } 2898 2899 return (maxmtu); 2900 } 2901 #endif /* INET6 */ 2902 2903 /* 2904 * Calculate effective SMSS per RFC5681 definition for a given TCP 2905 * connection at its current state, taking into account SACK and etc. 2906 */ 2907 u_int 2908 tcp_maxseg(const struct tcpcb *tp) 2909 { 2910 u_int optlen; 2911 2912 if (tp->t_flags & TF_NOOPT) 2913 return (tp->t_maxseg); 2914 2915 /* 2916 * Here we have a simplified code from tcp_addoptions(), 2917 * without a proper loop, and having most of paddings hardcoded. 2918 * We might make mistakes with padding here in some edge cases, 2919 * but this is harmless, since result of tcp_maxseg() is used 2920 * only in cwnd and ssthresh estimations. 2921 */ 2922 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2923 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2924 if (tp->t_flags & TF_RCVD_TSTMP) 2925 optlen = TCPOLEN_TSTAMP_APPA; 2926 else 2927 optlen = 0; 2928 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2929 if (tp->t_flags & TF_SIGNATURE) 2930 optlen += PAD(TCPOLEN_SIGNATURE); 2931 #endif 2932 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2933 optlen += TCPOLEN_SACKHDR; 2934 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2935 optlen = PAD(optlen); 2936 } 2937 } else { 2938 if (tp->t_flags & TF_REQ_TSTMP) 2939 optlen = TCPOLEN_TSTAMP_APPA; 2940 else 2941 optlen = PAD(TCPOLEN_MAXSEG); 2942 if (tp->t_flags & TF_REQ_SCALE) 2943 optlen += PAD(TCPOLEN_WINDOW); 2944 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2945 if (tp->t_flags & TF_SIGNATURE) 2946 optlen += PAD(TCPOLEN_SIGNATURE); 2947 #endif 2948 if (tp->t_flags & TF_SACK_PERMIT) 2949 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2950 } 2951 #undef PAD 2952 optlen = min(optlen, TCP_MAXOLEN); 2953 return (tp->t_maxseg - optlen); 2954 } 2955 2956 static int 2957 sysctl_drop(SYSCTL_HANDLER_ARGS) 2958 { 2959 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2960 struct sockaddr_storage addrs[2]; 2961 struct inpcb *inp; 2962 struct tcpcb *tp; 2963 struct tcptw *tw; 2964 struct sockaddr_in *fin, *lin; 2965 struct epoch_tracker et; 2966 #ifdef INET6 2967 struct sockaddr_in6 *fin6, *lin6; 2968 #endif 2969 int error; 2970 2971 inp = NULL; 2972 fin = lin = NULL; 2973 #ifdef INET6 2974 fin6 = lin6 = NULL; 2975 #endif 2976 error = 0; 2977 2978 if (req->oldptr != NULL || req->oldlen != 0) 2979 return (EINVAL); 2980 if (req->newptr == NULL) 2981 return (EPERM); 2982 if (req->newlen < sizeof(addrs)) 2983 return (ENOMEM); 2984 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2985 if (error) 2986 return (error); 2987 2988 switch (addrs[0].ss_family) { 2989 #ifdef INET6 2990 case AF_INET6: 2991 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2992 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2993 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2994 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2995 return (EINVAL); 2996 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2997 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2998 return (EINVAL); 2999 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3000 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3001 fin = (struct sockaddr_in *)&addrs[0]; 3002 lin = (struct sockaddr_in *)&addrs[1]; 3003 break; 3004 } 3005 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3006 if (error) 3007 return (error); 3008 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3009 if (error) 3010 return (error); 3011 break; 3012 #endif 3013 #ifdef INET 3014 case AF_INET: 3015 fin = (struct sockaddr_in *)&addrs[0]; 3016 lin = (struct sockaddr_in *)&addrs[1]; 3017 if (fin->sin_len != sizeof(struct sockaddr_in) || 3018 lin->sin_len != sizeof(struct sockaddr_in)) 3019 return (EINVAL); 3020 break; 3021 #endif 3022 default: 3023 return (EINVAL); 3024 } 3025 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3026 switch (addrs[0].ss_family) { 3027 #ifdef INET6 3028 case AF_INET6: 3029 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3030 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3031 INPLOOKUP_WLOCKPCB, NULL); 3032 break; 3033 #endif 3034 #ifdef INET 3035 case AF_INET: 3036 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3037 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3038 break; 3039 #endif 3040 } 3041 if (inp != NULL) { 3042 if (inp->inp_flags & INP_TIMEWAIT) { 3043 /* 3044 * XXXRW: There currently exists a state where an 3045 * inpcb is present, but its timewait state has been 3046 * discarded. For now, don't allow dropping of this 3047 * type of inpcb. 3048 */ 3049 tw = intotw(inp); 3050 if (tw != NULL) 3051 tcp_twclose(tw, 0); 3052 else 3053 INP_WUNLOCK(inp); 3054 } else if (!(inp->inp_flags & INP_DROPPED) && 3055 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3056 tp = intotcpcb(inp); 3057 tp = tcp_drop(tp, ECONNABORTED); 3058 if (tp != NULL) 3059 INP_WUNLOCK(inp); 3060 } else 3061 INP_WUNLOCK(inp); 3062 } else 3063 error = ESRCH; 3064 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3065 return (error); 3066 } 3067 3068 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3069 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3070 0, sysctl_drop, "", "Drop TCP connection"); 3071 3072 /* 3073 * Generate a standardized TCP log line for use throughout the 3074 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3075 * allow use in the interrupt context. 3076 * 3077 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3078 * NB: The function may return NULL if memory allocation failed. 3079 * 3080 * Due to header inclusion and ordering limitations the struct ip 3081 * and ip6_hdr pointers have to be passed as void pointers. 3082 */ 3083 char * 3084 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3085 const void *ip6hdr) 3086 { 3087 3088 /* Is logging enabled? */ 3089 if (tcp_log_in_vain == 0) 3090 return (NULL); 3091 3092 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3093 } 3094 3095 char * 3096 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3097 const void *ip6hdr) 3098 { 3099 3100 /* Is logging enabled? */ 3101 if (tcp_log_debug == 0) 3102 return (NULL); 3103 3104 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3105 } 3106 3107 static char * 3108 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3109 const void *ip6hdr) 3110 { 3111 char *s, *sp; 3112 size_t size; 3113 struct ip *ip; 3114 #ifdef INET6 3115 const struct ip6_hdr *ip6; 3116 3117 ip6 = (const struct ip6_hdr *)ip6hdr; 3118 #endif /* INET6 */ 3119 ip = (struct ip *)ip4hdr; 3120 3121 /* 3122 * The log line looks like this: 3123 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3124 */ 3125 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3126 sizeof(PRINT_TH_FLAGS) + 1 + 3127 #ifdef INET6 3128 2 * INET6_ADDRSTRLEN; 3129 #else 3130 2 * INET_ADDRSTRLEN; 3131 #endif /* INET6 */ 3132 3133 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3134 if (s == NULL) 3135 return (NULL); 3136 3137 strcat(s, "TCP: ["); 3138 sp = s + strlen(s); 3139 3140 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3141 inet_ntoa_r(inc->inc_faddr, sp); 3142 sp = s + strlen(s); 3143 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3144 sp = s + strlen(s); 3145 inet_ntoa_r(inc->inc_laddr, sp); 3146 sp = s + strlen(s); 3147 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3148 #ifdef INET6 3149 } else if (inc) { 3150 ip6_sprintf(sp, &inc->inc6_faddr); 3151 sp = s + strlen(s); 3152 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3153 sp = s + strlen(s); 3154 ip6_sprintf(sp, &inc->inc6_laddr); 3155 sp = s + strlen(s); 3156 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3157 } else if (ip6 && th) { 3158 ip6_sprintf(sp, &ip6->ip6_src); 3159 sp = s + strlen(s); 3160 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3161 sp = s + strlen(s); 3162 ip6_sprintf(sp, &ip6->ip6_dst); 3163 sp = s + strlen(s); 3164 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3165 #endif /* INET6 */ 3166 #ifdef INET 3167 } else if (ip && th) { 3168 inet_ntoa_r(ip->ip_src, sp); 3169 sp = s + strlen(s); 3170 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3171 sp = s + strlen(s); 3172 inet_ntoa_r(ip->ip_dst, sp); 3173 sp = s + strlen(s); 3174 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3175 #endif /* INET */ 3176 } else { 3177 free(s, M_TCPLOG); 3178 return (NULL); 3179 } 3180 sp = s + strlen(s); 3181 if (th) 3182 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3183 if (*(s + size - 1) != '\0') 3184 panic("%s: string too long", __func__); 3185 return (s); 3186 } 3187 3188 /* 3189 * A subroutine which makes it easy to track TCP state changes with DTrace. 3190 * This function shouldn't be called for t_state initializations that don't 3191 * correspond to actual TCP state transitions. 3192 */ 3193 void 3194 tcp_state_change(struct tcpcb *tp, int newstate) 3195 { 3196 #if defined(KDTRACE_HOOKS) 3197 int pstate = tp->t_state; 3198 #endif 3199 3200 TCPSTATES_DEC(tp->t_state); 3201 TCPSTATES_INC(newstate); 3202 tp->t_state = newstate; 3203 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3204 } 3205 3206 /* 3207 * Create an external-format (``xtcpcb'') structure using the information in 3208 * the kernel-format tcpcb structure pointed to by tp. This is done to 3209 * reduce the spew of irrelevant information over this interface, to isolate 3210 * user code from changes in the kernel structure, and potentially to provide 3211 * information-hiding if we decide that some of this information should be 3212 * hidden from users. 3213 */ 3214 void 3215 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3216 { 3217 struct tcpcb *tp = intotcpcb(inp); 3218 sbintime_t now; 3219 3220 bzero(xt, sizeof(*xt)); 3221 if (inp->inp_flags & INP_TIMEWAIT) { 3222 xt->t_state = TCPS_TIME_WAIT; 3223 } else { 3224 xt->t_state = tp->t_state; 3225 xt->t_logstate = tp->t_logstate; 3226 xt->t_flags = tp->t_flags; 3227 xt->t_sndzerowin = tp->t_sndzerowin; 3228 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3229 xt->t_rcvoopack = tp->t_rcvoopack; 3230 3231 now = getsbinuptime(); 3232 #define COPYTIMER(ttt) do { \ 3233 if (callout_active(&tp->t_timers->ttt)) \ 3234 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3235 SBT_1MS; \ 3236 else \ 3237 xt->ttt = 0; \ 3238 } while (0) 3239 COPYTIMER(tt_delack); 3240 COPYTIMER(tt_rexmt); 3241 COPYTIMER(tt_persist); 3242 COPYTIMER(tt_keep); 3243 COPYTIMER(tt_2msl); 3244 #undef COPYTIMER 3245 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3246 3247 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3248 TCP_FUNCTION_NAME_LEN_MAX); 3249 #ifdef TCP_BLACKBOX 3250 (void)tcp_log_get_id(tp, xt->xt_logid); 3251 #endif 3252 } 3253 3254 xt->xt_len = sizeof(struct xtcpcb); 3255 in_pcbtoxinpcb(inp, &xt->xt_inp); 3256 if (inp->inp_socket == NULL) 3257 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3258 } 3259