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_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/callout.h> 46 #include <sys/eventhandler.h> 47 #ifdef TCP_HHOOK 48 #include <sys/hhook.h> 49 #endif 50 #include <sys/kernel.h> 51 #ifdef TCP_HHOOK 52 #include <sys/khelp.h> 53 #endif 54 #ifdef KERN_TLS 55 #include <sys/ktls.h> 56 #endif 57 #include <sys/sysctl.h> 58 #include <sys/jail.h> 59 #include <sys/malloc.h> 60 #include <sys/refcount.h> 61 #include <sys/mbuf.h> 62 #ifdef INET6 63 #include <sys/domain.h> 64 #endif 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/sdt.h> 68 #include <sys/socket.h> 69 #include <sys/socketvar.h> 70 #include <sys/protosw.h> 71 #include <sys/random.h> 72 73 #include <vm/uma.h> 74 75 #include <net/route.h> 76 #include <net/if.h> 77 #include <net/if_var.h> 78 #include <net/vnet.h> 79 80 #include <netinet/in.h> 81 #include <netinet/in_fib.h> 82 #include <netinet/in_kdtrace.h> 83 #include <netinet/in_pcb.h> 84 #include <netinet/in_systm.h> 85 #include <netinet/in_var.h> 86 #include <netinet/ip.h> 87 #include <netinet/ip_icmp.h> 88 #include <netinet/ip_var.h> 89 #ifdef INET6 90 #include <netinet/icmp6.h> 91 #include <netinet/ip6.h> 92 #include <netinet6/in6_fib.h> 93 #include <netinet6/in6_pcb.h> 94 #include <netinet6/ip6_var.h> 95 #include <netinet6/scope6_var.h> 96 #include <netinet6/nd6.h> 97 #endif 98 99 #include <netinet/tcp.h> 100 #include <netinet/tcp_fsm.h> 101 #include <netinet/tcp_seq.h> 102 #include <netinet/tcp_timer.h> 103 #include <netinet/tcp_var.h> 104 #include <netinet/tcp_log_buf.h> 105 #include <netinet/tcp_syncache.h> 106 #include <netinet/tcp_hpts.h> 107 #include <netinet/cc/cc.h> 108 #ifdef INET6 109 #include <netinet6/tcp6_var.h> 110 #endif 111 #include <netinet/tcpip.h> 112 #include <netinet/tcp_fastopen.h> 113 #ifdef TCPPCAP 114 #include <netinet/tcp_pcap.h> 115 #endif 116 #ifdef TCPDEBUG 117 #include <netinet/tcp_debug.h> 118 #endif 119 #ifdef INET6 120 #include <netinet6/ip6protosw.h> 121 #endif 122 #ifdef TCP_OFFLOAD 123 #include <netinet/tcp_offload.h> 124 #endif 125 126 #include <netipsec/ipsec_support.h> 127 128 #include <machine/in_cksum.h> 129 #include <sys/md5.h> 130 131 #include <security/mac/mac_framework.h> 132 133 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 134 #ifdef INET6 135 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 136 #endif 137 138 struct rwlock tcp_function_lock; 139 140 static int 141 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 142 { 143 int error, new; 144 145 new = V_tcp_mssdflt; 146 error = sysctl_handle_int(oidp, &new, 0, req); 147 if (error == 0 && req->newptr) { 148 if (new < TCP_MINMSS) 149 error = EINVAL; 150 else 151 V_tcp_mssdflt = new; 152 } 153 return (error); 154 } 155 156 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 157 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 158 &sysctl_net_inet_tcp_mss_check, "I", 159 "Default TCP Maximum Segment Size"); 160 161 #ifdef INET6 162 static int 163 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 164 { 165 int error, new; 166 167 new = V_tcp_v6mssdflt; 168 error = sysctl_handle_int(oidp, &new, 0, req); 169 if (error == 0 && req->newptr) { 170 if (new < TCP_MINMSS) 171 error = EINVAL; 172 else 173 V_tcp_v6mssdflt = new; 174 } 175 return (error); 176 } 177 178 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 179 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 180 &sysctl_net_inet_tcp_mss_v6_check, "I", 181 "Default TCP Maximum Segment Size for IPv6"); 182 #endif /* INET6 */ 183 184 /* 185 * Minimum MSS we accept and use. This prevents DoS attacks where 186 * we are forced to a ridiculous low MSS like 20 and send hundreds 187 * of packets instead of one. The effect scales with the available 188 * bandwidth and quickly saturates the CPU and network interface 189 * with packet generation and sending. Set to zero to disable MINMSS 190 * checking. This setting prevents us from sending too small packets. 191 */ 192 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 193 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 194 &VNET_NAME(tcp_minmss), 0, 195 "Minimum TCP Maximum Segment Size"); 196 197 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 198 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 199 &VNET_NAME(tcp_do_rfc1323), 0, 200 "Enable rfc1323 (high performance TCP) extensions"); 201 202 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 204 &VNET_NAME(tcp_ts_offset_per_conn), 0, 205 "Initialize TCP timestamps per connection instead of per host pair"); 206 207 static int tcp_log_debug = 0; 208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 209 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 210 211 static int tcp_tcbhashsize; 212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 213 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 214 215 static int do_tcpdrain = 1; 216 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 217 "Enable tcp_drain routine for extra help when low on mbufs"); 218 219 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 220 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 221 222 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 223 #define V_icmp_may_rst VNET(icmp_may_rst) 224 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 225 &VNET_NAME(icmp_may_rst), 0, 226 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 227 228 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 229 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 230 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 231 &VNET_NAME(tcp_isn_reseed_interval), 0, 232 "Seconds between reseeding of ISN secret"); 233 234 static int tcp_soreceive_stream; 235 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 236 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 237 238 VNET_DEFINE(uma_zone_t, sack_hole_zone); 239 #define V_sack_hole_zone VNET(sack_hole_zone) 240 241 #ifdef TCP_HHOOK 242 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 243 #endif 244 245 #define TS_OFFSET_SECRET_LENGTH 32 246 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 247 #define V_ts_offset_secret VNET(ts_offset_secret) 248 249 static int tcp_default_fb_init(struct tcpcb *tp); 250 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 251 static int tcp_default_handoff_ok(struct tcpcb *tp); 252 static struct inpcb *tcp_notify(struct inpcb *, int); 253 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 254 static void tcp_mtudisc(struct inpcb *, int); 255 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 256 void *ip4hdr, const void *ip6hdr); 257 258 259 static struct tcp_function_block tcp_def_funcblk = { 260 .tfb_tcp_block_name = "freebsd", 261 .tfb_tcp_output = tcp_output, 262 .tfb_tcp_do_segment = tcp_do_segment, 263 .tfb_tcp_ctloutput = tcp_default_ctloutput, 264 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 265 .tfb_tcp_fb_init = tcp_default_fb_init, 266 .tfb_tcp_fb_fini = tcp_default_fb_fini, 267 }; 268 269 static int tcp_fb_cnt = 0; 270 struct tcp_funchead t_functions; 271 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 272 273 static struct tcp_function_block * 274 find_tcp_functions_locked(struct tcp_function_set *fs) 275 { 276 struct tcp_function *f; 277 struct tcp_function_block *blk=NULL; 278 279 TAILQ_FOREACH(f, &t_functions, tf_next) { 280 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 281 blk = f->tf_fb; 282 break; 283 } 284 } 285 return(blk); 286 } 287 288 static struct tcp_function_block * 289 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 290 { 291 struct tcp_function_block *rblk=NULL; 292 struct tcp_function *f; 293 294 TAILQ_FOREACH(f, &t_functions, tf_next) { 295 if (f->tf_fb == blk) { 296 rblk = blk; 297 if (s) { 298 *s = f; 299 } 300 break; 301 } 302 } 303 return (rblk); 304 } 305 306 struct tcp_function_block * 307 find_and_ref_tcp_functions(struct tcp_function_set *fs) 308 { 309 struct tcp_function_block *blk; 310 311 rw_rlock(&tcp_function_lock); 312 blk = find_tcp_functions_locked(fs); 313 if (blk) 314 refcount_acquire(&blk->tfb_refcnt); 315 rw_runlock(&tcp_function_lock); 316 return(blk); 317 } 318 319 struct tcp_function_block * 320 find_and_ref_tcp_fb(struct tcp_function_block *blk) 321 { 322 struct tcp_function_block *rblk; 323 324 rw_rlock(&tcp_function_lock); 325 rblk = find_tcp_fb_locked(blk, NULL); 326 if (rblk) 327 refcount_acquire(&rblk->tfb_refcnt); 328 rw_runlock(&tcp_function_lock); 329 return(rblk); 330 } 331 332 static struct tcp_function_block * 333 find_and_ref_tcp_default_fb(void) 334 { 335 struct tcp_function_block *rblk; 336 337 rw_rlock(&tcp_function_lock); 338 rblk = tcp_func_set_ptr; 339 refcount_acquire(&rblk->tfb_refcnt); 340 rw_runlock(&tcp_function_lock); 341 return (rblk); 342 } 343 344 void 345 tcp_switch_back_to_default(struct tcpcb *tp) 346 { 347 struct tcp_function_block *tfb; 348 349 KASSERT(tp->t_fb != &tcp_def_funcblk, 350 ("%s: called by the built-in default stack", __func__)); 351 352 /* 353 * Release the old stack. This function will either find a new one 354 * or panic. 355 */ 356 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 357 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 358 refcount_release(&tp->t_fb->tfb_refcnt); 359 360 /* 361 * Now, we'll find a new function block to use. 362 * Start by trying the current user-selected 363 * default, unless this stack is the user-selected 364 * default. 365 */ 366 tfb = find_and_ref_tcp_default_fb(); 367 if (tfb == tp->t_fb) { 368 refcount_release(&tfb->tfb_refcnt); 369 tfb = NULL; 370 } 371 /* Does the stack accept this connection? */ 372 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 373 (*tfb->tfb_tcp_handoff_ok)(tp)) { 374 refcount_release(&tfb->tfb_refcnt); 375 tfb = NULL; 376 } 377 /* Try to use that stack. */ 378 if (tfb != NULL) { 379 /* Initialize the new stack. If it succeeds, we are done. */ 380 tp->t_fb = tfb; 381 if (tp->t_fb->tfb_tcp_fb_init == NULL || 382 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 383 return; 384 385 /* 386 * Initialization failed. Release the reference count on 387 * the stack. 388 */ 389 refcount_release(&tfb->tfb_refcnt); 390 } 391 392 /* 393 * If that wasn't feasible, use the built-in default 394 * stack which is not allowed to reject anyone. 395 */ 396 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 397 if (tfb == NULL) { 398 /* there always should be a default */ 399 panic("Can't refer to tcp_def_funcblk"); 400 } 401 if (tfb->tfb_tcp_handoff_ok != NULL) { 402 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 403 /* The default stack cannot say no */ 404 panic("Default stack rejects a new session?"); 405 } 406 } 407 tp->t_fb = tfb; 408 if (tp->t_fb->tfb_tcp_fb_init != NULL && 409 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 410 /* The default stack cannot fail */ 411 panic("Default stack initialization failed"); 412 } 413 } 414 415 static int 416 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 417 { 418 int error=ENOENT; 419 struct tcp_function_set fs; 420 struct tcp_function_block *blk; 421 422 memset(&fs, 0, sizeof(fs)); 423 rw_rlock(&tcp_function_lock); 424 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 425 if (blk) { 426 /* Found him */ 427 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 428 fs.pcbcnt = blk->tfb_refcnt; 429 } 430 rw_runlock(&tcp_function_lock); 431 error = sysctl_handle_string(oidp, fs.function_set_name, 432 sizeof(fs.function_set_name), req); 433 434 /* Check for error or no change */ 435 if (error != 0 || req->newptr == NULL) 436 return(error); 437 438 rw_wlock(&tcp_function_lock); 439 blk = find_tcp_functions_locked(&fs); 440 if ((blk == NULL) || 441 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 442 error = ENOENT; 443 goto done; 444 } 445 tcp_func_set_ptr = blk; 446 done: 447 rw_wunlock(&tcp_function_lock); 448 return (error); 449 } 450 451 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 452 CTLTYPE_STRING | CTLFLAG_RW, 453 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 454 "Set/get the default TCP functions"); 455 456 static int 457 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 458 { 459 int error, cnt, linesz; 460 struct tcp_function *f; 461 char *buffer, *cp; 462 size_t bufsz, outsz; 463 bool alias; 464 465 cnt = 0; 466 rw_rlock(&tcp_function_lock); 467 TAILQ_FOREACH(f, &t_functions, tf_next) { 468 cnt++; 469 } 470 rw_runlock(&tcp_function_lock); 471 472 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 473 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 474 475 error = 0; 476 cp = buffer; 477 478 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 479 "Alias", "PCB count"); 480 cp += linesz; 481 bufsz -= linesz; 482 outsz = linesz; 483 484 rw_rlock(&tcp_function_lock); 485 TAILQ_FOREACH(f, &t_functions, tf_next) { 486 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 487 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 488 f->tf_fb->tfb_tcp_block_name, 489 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 490 alias ? f->tf_name : "-", 491 f->tf_fb->tfb_refcnt); 492 if (linesz >= bufsz) { 493 error = EOVERFLOW; 494 break; 495 } 496 cp += linesz; 497 bufsz -= linesz; 498 outsz += linesz; 499 } 500 rw_runlock(&tcp_function_lock); 501 if (error == 0) 502 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 503 free(buffer, M_TEMP); 504 return (error); 505 } 506 507 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 508 CTLTYPE_STRING|CTLFLAG_RD, 509 NULL, 0, sysctl_net_inet_list_available, "A", 510 "list available TCP Function sets"); 511 512 /* 513 * Exports one (struct tcp_function_info) for each alias/name. 514 */ 515 static int 516 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 517 { 518 int cnt, error; 519 struct tcp_function *f; 520 struct tcp_function_info tfi; 521 522 /* 523 * We don't allow writes. 524 */ 525 if (req->newptr != NULL) 526 return (EINVAL); 527 528 /* 529 * Wire the old buffer so we can directly copy the functions to 530 * user space without dropping the lock. 531 */ 532 if (req->oldptr != NULL) { 533 error = sysctl_wire_old_buffer(req, 0); 534 if (error) 535 return (error); 536 } 537 538 /* 539 * Walk the list and copy out matching entries. If INVARIANTS 540 * is compiled in, also walk the list to verify the length of 541 * the list matches what we have recorded. 542 */ 543 rw_rlock(&tcp_function_lock); 544 545 cnt = 0; 546 #ifndef INVARIANTS 547 if (req->oldptr == NULL) { 548 cnt = tcp_fb_cnt; 549 goto skip_loop; 550 } 551 #endif 552 TAILQ_FOREACH(f, &t_functions, tf_next) { 553 #ifdef INVARIANTS 554 cnt++; 555 #endif 556 if (req->oldptr != NULL) { 557 bzero(&tfi, sizeof(tfi)); 558 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 559 tfi.tfi_id = f->tf_fb->tfb_id; 560 (void)strlcpy(tfi.tfi_alias, f->tf_name, 561 sizeof(tfi.tfi_alias)); 562 (void)strlcpy(tfi.tfi_name, 563 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 564 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 565 /* 566 * Don't stop on error, as that is the 567 * mechanism we use to accumulate length 568 * information if the buffer was too short. 569 */ 570 } 571 } 572 KASSERT(cnt == tcp_fb_cnt, 573 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 574 #ifndef INVARIANTS 575 skip_loop: 576 #endif 577 rw_runlock(&tcp_function_lock); 578 if (req->oldptr == NULL) 579 error = SYSCTL_OUT(req, NULL, 580 (cnt + 1) * sizeof(struct tcp_function_info)); 581 582 return (error); 583 } 584 585 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 586 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 587 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 588 "List TCP function block name-to-ID mappings"); 589 590 /* 591 * tfb_tcp_handoff_ok() function for the default stack. 592 * Note that we'll basically try to take all comers. 593 */ 594 static int 595 tcp_default_handoff_ok(struct tcpcb *tp) 596 { 597 598 return (0); 599 } 600 601 /* 602 * tfb_tcp_fb_init() function for the default stack. 603 * 604 * This handles making sure we have appropriate timers set if you are 605 * transitioning a socket that has some amount of setup done. 606 * 607 * The init() fuction from the default can *never* return non-zero i.e. 608 * it is required to always succeed since it is the stack of last resort! 609 */ 610 static int 611 tcp_default_fb_init(struct tcpcb *tp) 612 { 613 614 struct socket *so; 615 616 INP_WLOCK_ASSERT(tp->t_inpcb); 617 618 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 619 ("%s: connection %p in unexpected state %d", __func__, tp, 620 tp->t_state)); 621 622 /* 623 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 624 * know what to do for unexpected states (which includes TIME_WAIT). 625 */ 626 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 627 return (0); 628 629 /* 630 * Make sure some kind of transmission timer is set if there is 631 * outstanding data. 632 */ 633 so = tp->t_inpcb->inp_socket; 634 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 635 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 636 tcp_timer_active(tp, TT_PERSIST))) { 637 /* 638 * If the session has established and it looks like it should 639 * be in the persist state, set the persist timer. Otherwise, 640 * set the retransmit timer. 641 */ 642 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 643 (int32_t)(tp->snd_nxt - tp->snd_una) < 644 (int32_t)sbavail(&so->so_snd)) 645 tcp_setpersist(tp); 646 else 647 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 648 } 649 650 /* All non-embryonic sessions get a keepalive timer. */ 651 if (!tcp_timer_active(tp, TT_KEEP)) 652 tcp_timer_activate(tp, TT_KEEP, 653 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 654 TP_KEEPINIT(tp)); 655 656 return (0); 657 } 658 659 /* 660 * tfb_tcp_fb_fini() function for the default stack. 661 * 662 * This changes state as necessary (or prudent) to prepare for another stack 663 * to assume responsibility for the connection. 664 */ 665 static void 666 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 667 { 668 669 INP_WLOCK_ASSERT(tp->t_inpcb); 670 return; 671 } 672 673 /* 674 * Target size of TCP PCB hash tables. Must be a power of two. 675 * 676 * Note that this can be overridden by the kernel environment 677 * variable net.inet.tcp.tcbhashsize 678 */ 679 #ifndef TCBHASHSIZE 680 #define TCBHASHSIZE 0 681 #endif 682 683 /* 684 * XXX 685 * Callouts should be moved into struct tcp directly. They are currently 686 * separate because the tcpcb structure is exported to userland for sysctl 687 * parsing purposes, which do not know about callouts. 688 */ 689 struct tcpcb_mem { 690 struct tcpcb tcb; 691 struct tcp_timer tt; 692 struct cc_var ccv; 693 #ifdef TCP_HHOOK 694 struct osd osd; 695 #endif 696 }; 697 698 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 699 #define V_tcpcb_zone VNET(tcpcb_zone) 700 701 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 702 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 703 704 static struct mtx isn_mtx; 705 706 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 707 #define ISN_LOCK() mtx_lock(&isn_mtx) 708 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 709 710 /* 711 * TCP initialization. 712 */ 713 static void 714 tcp_zone_change(void *tag) 715 { 716 717 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 718 uma_zone_set_max(V_tcpcb_zone, maxsockets); 719 tcp_tw_zone_change(); 720 } 721 722 static int 723 tcp_inpcb_init(void *mem, int size, int flags) 724 { 725 struct inpcb *inp = mem; 726 727 INP_LOCK_INIT(inp, "inp", "tcpinp"); 728 return (0); 729 } 730 731 /* 732 * Take a value and get the next power of 2 that doesn't overflow. 733 * Used to size the tcp_inpcb hash buckets. 734 */ 735 static int 736 maketcp_hashsize(int size) 737 { 738 int hashsize; 739 740 /* 741 * auto tune. 742 * get the next power of 2 higher than maxsockets. 743 */ 744 hashsize = 1 << fls(size); 745 /* catch overflow, and just go one power of 2 smaller */ 746 if (hashsize < size) { 747 hashsize = 1 << (fls(size) - 1); 748 } 749 return (hashsize); 750 } 751 752 static volatile int next_tcp_stack_id = 1; 753 754 /* 755 * Register a TCP function block with the name provided in the names 756 * array. (Note that this function does NOT automatically register 757 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 758 * explicitly include blk->tfb_tcp_block_name in the list of names if 759 * you wish to register the stack with that name.) 760 * 761 * Either all name registrations will succeed or all will fail. If 762 * a name registration fails, the function will update the num_names 763 * argument to point to the array index of the name that encountered 764 * the failure. 765 * 766 * Returns 0 on success, or an error code on failure. 767 */ 768 int 769 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 770 const char *names[], int *num_names) 771 { 772 struct tcp_function *n; 773 struct tcp_function_set fs; 774 int error, i; 775 776 KASSERT(names != NULL && *num_names > 0, 777 ("%s: Called with 0-length name list", __func__)); 778 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 779 KASSERT(rw_initialized(&tcp_function_lock), 780 ("%s: called too early", __func__)); 781 782 if ((blk->tfb_tcp_output == NULL) || 783 (blk->tfb_tcp_do_segment == NULL) || 784 (blk->tfb_tcp_ctloutput == NULL) || 785 (strlen(blk->tfb_tcp_block_name) == 0)) { 786 /* 787 * These functions are required and you 788 * need a name. 789 */ 790 *num_names = 0; 791 return (EINVAL); 792 } 793 if (blk->tfb_tcp_timer_stop_all || 794 blk->tfb_tcp_timer_activate || 795 blk->tfb_tcp_timer_active || 796 blk->tfb_tcp_timer_stop) { 797 /* 798 * If you define one timer function you 799 * must have them all. 800 */ 801 if ((blk->tfb_tcp_timer_stop_all == NULL) || 802 (blk->tfb_tcp_timer_activate == NULL) || 803 (blk->tfb_tcp_timer_active == NULL) || 804 (blk->tfb_tcp_timer_stop == NULL)) { 805 *num_names = 0; 806 return (EINVAL); 807 } 808 } 809 810 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 811 *num_names = 0; 812 return (EINVAL); 813 } 814 815 refcount_init(&blk->tfb_refcnt, 0); 816 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 817 for (i = 0; i < *num_names; i++) { 818 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 819 if (n == NULL) { 820 error = ENOMEM; 821 goto cleanup; 822 } 823 n->tf_fb = blk; 824 825 (void)strlcpy(fs.function_set_name, names[i], 826 sizeof(fs.function_set_name)); 827 rw_wlock(&tcp_function_lock); 828 if (find_tcp_functions_locked(&fs) != NULL) { 829 /* Duplicate name space not allowed */ 830 rw_wunlock(&tcp_function_lock); 831 free(n, M_TCPFUNCTIONS); 832 error = EALREADY; 833 goto cleanup; 834 } 835 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 836 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 837 tcp_fb_cnt++; 838 rw_wunlock(&tcp_function_lock); 839 } 840 return(0); 841 842 cleanup: 843 /* 844 * Deregister the names we just added. Because registration failed 845 * for names[i], we don't need to deregister that name. 846 */ 847 *num_names = i; 848 rw_wlock(&tcp_function_lock); 849 while (--i >= 0) { 850 TAILQ_FOREACH(n, &t_functions, tf_next) { 851 if (!strncmp(n->tf_name, names[i], 852 TCP_FUNCTION_NAME_LEN_MAX)) { 853 TAILQ_REMOVE(&t_functions, n, tf_next); 854 tcp_fb_cnt--; 855 n->tf_fb = NULL; 856 free(n, M_TCPFUNCTIONS); 857 break; 858 } 859 } 860 } 861 rw_wunlock(&tcp_function_lock); 862 return (error); 863 } 864 865 /* 866 * Register a TCP function block using the name provided in the name 867 * argument. 868 * 869 * Returns 0 on success, or an error code on failure. 870 */ 871 int 872 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 873 int wait) 874 { 875 const char *name_list[1]; 876 int num_names, rv; 877 878 num_names = 1; 879 if (name != NULL) 880 name_list[0] = name; 881 else 882 name_list[0] = blk->tfb_tcp_block_name; 883 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 884 return (rv); 885 } 886 887 /* 888 * Register a TCP function block using the name defined in 889 * blk->tfb_tcp_block_name. 890 * 891 * Returns 0 on success, or an error code on failure. 892 */ 893 int 894 register_tcp_functions(struct tcp_function_block *blk, int wait) 895 { 896 897 return (register_tcp_functions_as_name(blk, NULL, wait)); 898 } 899 900 /* 901 * Deregister all names associated with a function block. This 902 * functionally removes the function block from use within the system. 903 * 904 * When called with a true quiesce argument, mark the function block 905 * as being removed so no more stacks will use it and determine 906 * whether the removal would succeed. 907 * 908 * When called with a false quiesce argument, actually attempt the 909 * removal. 910 * 911 * When called with a force argument, attempt to switch all TCBs to 912 * use the default stack instead of returning EBUSY. 913 * 914 * Returns 0 on success (or if the removal would succeed, or an error 915 * code on failure. 916 */ 917 int 918 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 919 bool force) 920 { 921 struct tcp_function *f; 922 923 if (blk == &tcp_def_funcblk) { 924 /* You can't un-register the default */ 925 return (EPERM); 926 } 927 rw_wlock(&tcp_function_lock); 928 if (blk == tcp_func_set_ptr) { 929 /* You can't free the current default */ 930 rw_wunlock(&tcp_function_lock); 931 return (EBUSY); 932 } 933 /* Mark the block so no more stacks can use it. */ 934 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 935 /* 936 * If TCBs are still attached to the stack, attempt to switch them 937 * to the default stack. 938 */ 939 if (force && blk->tfb_refcnt) { 940 struct inpcb *inp; 941 struct tcpcb *tp; 942 VNET_ITERATOR_DECL(vnet_iter); 943 944 rw_wunlock(&tcp_function_lock); 945 946 VNET_LIST_RLOCK(); 947 VNET_FOREACH(vnet_iter) { 948 CURVNET_SET(vnet_iter); 949 INP_INFO_WLOCK(&V_tcbinfo); 950 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 951 INP_WLOCK(inp); 952 if (inp->inp_flags & INP_TIMEWAIT) { 953 INP_WUNLOCK(inp); 954 continue; 955 } 956 tp = intotcpcb(inp); 957 if (tp == NULL || tp->t_fb != blk) { 958 INP_WUNLOCK(inp); 959 continue; 960 } 961 tcp_switch_back_to_default(tp); 962 INP_WUNLOCK(inp); 963 } 964 INP_INFO_WUNLOCK(&V_tcbinfo); 965 CURVNET_RESTORE(); 966 } 967 VNET_LIST_RUNLOCK(); 968 969 rw_wlock(&tcp_function_lock); 970 } 971 if (blk->tfb_refcnt) { 972 /* TCBs still attached. */ 973 rw_wunlock(&tcp_function_lock); 974 return (EBUSY); 975 } 976 if (quiesce) { 977 /* Skip removal. */ 978 rw_wunlock(&tcp_function_lock); 979 return (0); 980 } 981 /* Remove any function names that map to this function block. */ 982 while (find_tcp_fb_locked(blk, &f) != NULL) { 983 TAILQ_REMOVE(&t_functions, f, tf_next); 984 tcp_fb_cnt--; 985 f->tf_fb = NULL; 986 free(f, M_TCPFUNCTIONS); 987 } 988 rw_wunlock(&tcp_function_lock); 989 return (0); 990 } 991 992 void 993 tcp_init(void) 994 { 995 const char *tcbhash_tuneable; 996 int hashsize; 997 998 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 999 1000 #ifdef TCP_HHOOK 1001 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1002 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1003 printf("%s: WARNING: unable to register helper hook\n", __func__); 1004 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1005 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1006 printf("%s: WARNING: unable to register helper hook\n", __func__); 1007 #endif 1008 hashsize = TCBHASHSIZE; 1009 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1010 if (hashsize == 0) { 1011 /* 1012 * Auto tune the hash size based on maxsockets. 1013 * A perfect hash would have a 1:1 mapping 1014 * (hashsize = maxsockets) however it's been 1015 * suggested that O(2) average is better. 1016 */ 1017 hashsize = maketcp_hashsize(maxsockets / 4); 1018 /* 1019 * Our historical default is 512, 1020 * do not autotune lower than this. 1021 */ 1022 if (hashsize < 512) 1023 hashsize = 512; 1024 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1025 printf("%s: %s auto tuned to %d\n", __func__, 1026 tcbhash_tuneable, hashsize); 1027 } 1028 /* 1029 * We require a hashsize to be a power of two. 1030 * Previously if it was not a power of two we would just reset it 1031 * back to 512, which could be a nasty surprise if you did not notice 1032 * the error message. 1033 * Instead what we do is clip it to the closest power of two lower 1034 * than the specified hash value. 1035 */ 1036 if (!powerof2(hashsize)) { 1037 int oldhashsize = hashsize; 1038 1039 hashsize = maketcp_hashsize(hashsize); 1040 /* prevent absurdly low value */ 1041 if (hashsize < 16) 1042 hashsize = 16; 1043 printf("%s: WARNING: TCB hash size not a power of 2, " 1044 "clipped from %d to %d.\n", __func__, oldhashsize, 1045 hashsize); 1046 } 1047 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1048 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1049 1050 /* 1051 * These have to be type stable for the benefit of the timers. 1052 */ 1053 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1054 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1055 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1056 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1057 1058 tcp_tw_init(); 1059 syncache_init(); 1060 tcp_hc_init(); 1061 1062 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1063 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1064 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1065 1066 tcp_fastopen_init(); 1067 1068 /* Skip initialization of globals for non-default instances. */ 1069 if (!IS_DEFAULT_VNET(curvnet)) 1070 return; 1071 1072 tcp_reass_global_init(); 1073 1074 /* XXX virtualize those bellow? */ 1075 tcp_delacktime = TCPTV_DELACK; 1076 tcp_keepinit = TCPTV_KEEP_INIT; 1077 tcp_keepidle = TCPTV_KEEP_IDLE; 1078 tcp_keepintvl = TCPTV_KEEPINTVL; 1079 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1080 tcp_msl = TCPTV_MSL; 1081 tcp_rexmit_initial = TCPTV_RTOBASE; 1082 if (tcp_rexmit_initial < 1) 1083 tcp_rexmit_initial = 1; 1084 tcp_rexmit_min = TCPTV_MIN; 1085 if (tcp_rexmit_min < 1) 1086 tcp_rexmit_min = 1; 1087 tcp_persmin = TCPTV_PERSMIN; 1088 tcp_persmax = TCPTV_PERSMAX; 1089 tcp_rexmit_slop = TCPTV_CPU_VAR; 1090 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1091 tcp_tcbhashsize = hashsize; 1092 1093 /* Setup the tcp function block list */ 1094 TAILQ_INIT(&t_functions); 1095 rw_init(&tcp_function_lock, "tcp_func_lock"); 1096 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1097 #ifdef TCP_BLACKBOX 1098 /* Initialize the TCP logging data. */ 1099 tcp_log_init(); 1100 #endif 1101 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1102 1103 if (tcp_soreceive_stream) { 1104 #ifdef INET 1105 tcp_usrreqs.pru_soreceive = soreceive_stream; 1106 #endif 1107 #ifdef INET6 1108 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1109 #endif /* INET6 */ 1110 } 1111 1112 #ifdef INET6 1113 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1114 #else /* INET6 */ 1115 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1116 #endif /* INET6 */ 1117 if (max_protohdr < TCP_MINPROTOHDR) 1118 max_protohdr = TCP_MINPROTOHDR; 1119 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1120 panic("tcp_init"); 1121 #undef TCP_MINPROTOHDR 1122 1123 ISN_LOCK_INIT(); 1124 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1125 SHUTDOWN_PRI_DEFAULT); 1126 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1127 EVENTHANDLER_PRI_ANY); 1128 #ifdef TCPPCAP 1129 tcp_pcap_init(); 1130 #endif 1131 } 1132 1133 #ifdef VIMAGE 1134 static void 1135 tcp_destroy(void *unused __unused) 1136 { 1137 int n; 1138 #ifdef TCP_HHOOK 1139 int error; 1140 #endif 1141 1142 /* 1143 * All our processes are gone, all our sockets should be cleaned 1144 * up, which means, we should be past the tcp_discardcb() calls. 1145 * Sleep to let all tcpcb timers really disappear and cleanup. 1146 */ 1147 for (;;) { 1148 INP_LIST_RLOCK(&V_tcbinfo); 1149 n = V_tcbinfo.ipi_count; 1150 INP_LIST_RUNLOCK(&V_tcbinfo); 1151 if (n == 0) 1152 break; 1153 pause("tcpdes", hz / 10); 1154 } 1155 tcp_hc_destroy(); 1156 syncache_destroy(); 1157 tcp_tw_destroy(); 1158 in_pcbinfo_destroy(&V_tcbinfo); 1159 /* tcp_discardcb() clears the sack_holes up. */ 1160 uma_zdestroy(V_sack_hole_zone); 1161 uma_zdestroy(V_tcpcb_zone); 1162 1163 /* 1164 * Cannot free the zone until all tcpcbs are released as we attach 1165 * the allocations to them. 1166 */ 1167 tcp_fastopen_destroy(); 1168 1169 #ifdef TCP_HHOOK 1170 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1171 if (error != 0) { 1172 printf("%s: WARNING: unable to deregister helper hook " 1173 "type=%d, id=%d: error %d returned\n", __func__, 1174 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1175 } 1176 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1177 if (error != 0) { 1178 printf("%s: WARNING: unable to deregister helper hook " 1179 "type=%d, id=%d: error %d returned\n", __func__, 1180 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1181 } 1182 #endif 1183 } 1184 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1185 #endif 1186 1187 void 1188 tcp_fini(void *xtp) 1189 { 1190 1191 } 1192 1193 /* 1194 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1195 * tcp_template used to store this data in mbufs, but we now recopy it out 1196 * of the tcpcb each time to conserve mbufs. 1197 */ 1198 void 1199 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1200 { 1201 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1202 1203 INP_WLOCK_ASSERT(inp); 1204 1205 #ifdef INET6 1206 if ((inp->inp_vflag & INP_IPV6) != 0) { 1207 struct ip6_hdr *ip6; 1208 1209 ip6 = (struct ip6_hdr *)ip_ptr; 1210 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1211 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1212 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1213 (IPV6_VERSION & IPV6_VERSION_MASK); 1214 ip6->ip6_nxt = IPPROTO_TCP; 1215 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1216 ip6->ip6_src = inp->in6p_laddr; 1217 ip6->ip6_dst = inp->in6p_faddr; 1218 } 1219 #endif /* INET6 */ 1220 #if defined(INET6) && defined(INET) 1221 else 1222 #endif 1223 #ifdef INET 1224 { 1225 struct ip *ip; 1226 1227 ip = (struct ip *)ip_ptr; 1228 ip->ip_v = IPVERSION; 1229 ip->ip_hl = 5; 1230 ip->ip_tos = inp->inp_ip_tos; 1231 ip->ip_len = 0; 1232 ip->ip_id = 0; 1233 ip->ip_off = 0; 1234 ip->ip_ttl = inp->inp_ip_ttl; 1235 ip->ip_sum = 0; 1236 ip->ip_p = IPPROTO_TCP; 1237 ip->ip_src = inp->inp_laddr; 1238 ip->ip_dst = inp->inp_faddr; 1239 } 1240 #endif /* INET */ 1241 th->th_sport = inp->inp_lport; 1242 th->th_dport = inp->inp_fport; 1243 th->th_seq = 0; 1244 th->th_ack = 0; 1245 th->th_x2 = 0; 1246 th->th_off = 5; 1247 th->th_flags = 0; 1248 th->th_win = 0; 1249 th->th_urp = 0; 1250 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1251 } 1252 1253 /* 1254 * Create template to be used to send tcp packets on a connection. 1255 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1256 * use for this function is in keepalives, which use tcp_respond. 1257 */ 1258 struct tcptemp * 1259 tcpip_maketemplate(struct inpcb *inp) 1260 { 1261 struct tcptemp *t; 1262 1263 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1264 if (t == NULL) 1265 return (NULL); 1266 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1267 return (t); 1268 } 1269 1270 /* 1271 * Send a single message to the TCP at address specified by 1272 * the given TCP/IP header. If m == NULL, then we make a copy 1273 * of the tcpiphdr at th and send directly to the addressed host. 1274 * This is used to force keep alive messages out using the TCP 1275 * template for a connection. If flags are given then we send 1276 * a message back to the TCP which originated the segment th, 1277 * and discard the mbuf containing it and any other attached mbufs. 1278 * 1279 * In any case the ack and sequence number of the transmitted 1280 * segment are as specified by the parameters. 1281 * 1282 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1283 */ 1284 void 1285 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1286 tcp_seq ack, tcp_seq seq, int flags) 1287 { 1288 struct tcpopt to; 1289 struct inpcb *inp; 1290 struct ip *ip; 1291 struct mbuf *optm; 1292 struct tcphdr *nth; 1293 u_char *optp; 1294 #ifdef INET6 1295 struct ip6_hdr *ip6; 1296 int isipv6; 1297 #endif /* INET6 */ 1298 int optlen, tlen, win; 1299 bool incl_opts; 1300 1301 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1302 1303 #ifdef INET6 1304 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1305 ip6 = ipgen; 1306 #endif /* INET6 */ 1307 ip = ipgen; 1308 1309 if (tp != NULL) { 1310 inp = tp->t_inpcb; 1311 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1312 INP_WLOCK_ASSERT(inp); 1313 } else 1314 inp = NULL; 1315 1316 incl_opts = false; 1317 win = 0; 1318 if (tp != NULL) { 1319 if (!(flags & TH_RST)) { 1320 win = sbspace(&inp->inp_socket->so_rcv); 1321 if (win > TCP_MAXWIN << tp->rcv_scale) 1322 win = TCP_MAXWIN << tp->rcv_scale; 1323 } 1324 if ((tp->t_flags & TF_NOOPT) == 0) 1325 incl_opts = true; 1326 } 1327 if (m == NULL) { 1328 m = m_gethdr(M_NOWAIT, MT_DATA); 1329 if (m == NULL) 1330 return; 1331 m->m_data += max_linkhdr; 1332 #ifdef INET6 1333 if (isipv6) { 1334 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1335 sizeof(struct ip6_hdr)); 1336 ip6 = mtod(m, struct ip6_hdr *); 1337 nth = (struct tcphdr *)(ip6 + 1); 1338 } else 1339 #endif /* INET6 */ 1340 { 1341 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1342 ip = mtod(m, struct ip *); 1343 nth = (struct tcphdr *)(ip + 1); 1344 } 1345 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1346 flags = TH_ACK; 1347 } else if (!M_WRITABLE(m)) { 1348 struct mbuf *n; 1349 1350 /* Can't reuse 'm', allocate a new mbuf. */ 1351 n = m_gethdr(M_NOWAIT, MT_DATA); 1352 if (n == NULL) { 1353 m_freem(m); 1354 return; 1355 } 1356 1357 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1358 m_freem(m); 1359 m_freem(n); 1360 return; 1361 } 1362 1363 n->m_data += max_linkhdr; 1364 /* m_len is set later */ 1365 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1366 #ifdef INET6 1367 if (isipv6) { 1368 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1369 sizeof(struct ip6_hdr)); 1370 ip6 = mtod(n, struct ip6_hdr *); 1371 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1372 nth = (struct tcphdr *)(ip6 + 1); 1373 } else 1374 #endif /* INET6 */ 1375 { 1376 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1377 ip = mtod(n, struct ip *); 1378 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1379 nth = (struct tcphdr *)(ip + 1); 1380 } 1381 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1382 xchg(nth->th_dport, nth->th_sport, uint16_t); 1383 th = nth; 1384 m_freem(m); 1385 m = n; 1386 } else { 1387 /* 1388 * reuse the mbuf. 1389 * XXX MRT We inherit the FIB, which is lucky. 1390 */ 1391 m_freem(m->m_next); 1392 m->m_next = NULL; 1393 m->m_data = (caddr_t)ipgen; 1394 /* m_len is set later */ 1395 #ifdef INET6 1396 if (isipv6) { 1397 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1398 nth = (struct tcphdr *)(ip6 + 1); 1399 } else 1400 #endif /* INET6 */ 1401 { 1402 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1403 nth = (struct tcphdr *)(ip + 1); 1404 } 1405 if (th != nth) { 1406 /* 1407 * this is usually a case when an extension header 1408 * exists between the IPv6 header and the 1409 * TCP header. 1410 */ 1411 nth->th_sport = th->th_sport; 1412 nth->th_dport = th->th_dport; 1413 } 1414 xchg(nth->th_dport, nth->th_sport, uint16_t); 1415 #undef xchg 1416 } 1417 tlen = 0; 1418 #ifdef INET6 1419 if (isipv6) 1420 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1421 #endif 1422 #if defined(INET) && defined(INET6) 1423 else 1424 #endif 1425 #ifdef INET 1426 tlen = sizeof (struct tcpiphdr); 1427 #endif 1428 #ifdef INVARIANTS 1429 m->m_len = 0; 1430 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1431 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1432 m, tlen, (long)M_TRAILINGSPACE(m))); 1433 #endif 1434 m->m_len = tlen; 1435 to.to_flags = 0; 1436 if (incl_opts) { 1437 /* Make sure we have room. */ 1438 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1439 m->m_next = m_get(M_NOWAIT, MT_DATA); 1440 if (m->m_next) { 1441 optp = mtod(m->m_next, u_char *); 1442 optm = m->m_next; 1443 } else 1444 incl_opts = false; 1445 } else { 1446 optp = (u_char *) (nth + 1); 1447 optm = m; 1448 } 1449 } 1450 if (incl_opts) { 1451 /* Timestamps. */ 1452 if (tp->t_flags & TF_RCVD_TSTMP) { 1453 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1454 to.to_tsecr = tp->ts_recent; 1455 to.to_flags |= TOF_TS; 1456 } 1457 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1458 /* TCP-MD5 (RFC2385). */ 1459 if (tp->t_flags & TF_SIGNATURE) 1460 to.to_flags |= TOF_SIGNATURE; 1461 #endif 1462 /* Add the options. */ 1463 tlen += optlen = tcp_addoptions(&to, optp); 1464 1465 /* Update m_len in the correct mbuf. */ 1466 optm->m_len += optlen; 1467 } else 1468 optlen = 0; 1469 #ifdef INET6 1470 if (isipv6) { 1471 ip6->ip6_flow = 0; 1472 ip6->ip6_vfc = IPV6_VERSION; 1473 ip6->ip6_nxt = IPPROTO_TCP; 1474 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1475 } 1476 #endif 1477 #if defined(INET) && defined(INET6) 1478 else 1479 #endif 1480 #ifdef INET 1481 { 1482 ip->ip_len = htons(tlen); 1483 ip->ip_ttl = V_ip_defttl; 1484 if (V_path_mtu_discovery) 1485 ip->ip_off |= htons(IP_DF); 1486 } 1487 #endif 1488 m->m_pkthdr.len = tlen; 1489 m->m_pkthdr.rcvif = NULL; 1490 #ifdef MAC 1491 if (inp != NULL) { 1492 /* 1493 * Packet is associated with a socket, so allow the 1494 * label of the response to reflect the socket label. 1495 */ 1496 INP_WLOCK_ASSERT(inp); 1497 mac_inpcb_create_mbuf(inp, m); 1498 } else { 1499 /* 1500 * Packet is not associated with a socket, so possibly 1501 * update the label in place. 1502 */ 1503 mac_netinet_tcp_reply(m); 1504 } 1505 #endif 1506 nth->th_seq = htonl(seq); 1507 nth->th_ack = htonl(ack); 1508 nth->th_x2 = 0; 1509 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1510 nth->th_flags = flags; 1511 if (tp != NULL) 1512 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1513 else 1514 nth->th_win = htons((u_short)win); 1515 nth->th_urp = 0; 1516 1517 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1518 if (to.to_flags & TOF_SIGNATURE) { 1519 if (!TCPMD5_ENABLED() || 1520 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1521 m_freem(m); 1522 return; 1523 } 1524 } 1525 #endif 1526 1527 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1528 #ifdef INET6 1529 if (isipv6) { 1530 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1531 nth->th_sum = in6_cksum_pseudo(ip6, 1532 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1533 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1534 NULL, NULL); 1535 } 1536 #endif /* INET6 */ 1537 #if defined(INET6) && defined(INET) 1538 else 1539 #endif 1540 #ifdef INET 1541 { 1542 m->m_pkthdr.csum_flags = CSUM_TCP; 1543 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1544 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1545 } 1546 #endif /* INET */ 1547 #ifdef TCPDEBUG 1548 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1549 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1550 #endif 1551 TCP_PROBE3(debug__output, tp, th, m); 1552 if (flags & TH_RST) 1553 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1554 1555 #ifdef INET6 1556 if (isipv6) { 1557 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1558 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1559 } 1560 #endif /* INET6 */ 1561 #if defined(INET) && defined(INET6) 1562 else 1563 #endif 1564 #ifdef INET 1565 { 1566 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1567 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1568 } 1569 #endif 1570 } 1571 1572 /* 1573 * Create a new TCP control block, making an 1574 * empty reassembly queue and hooking it to the argument 1575 * protocol control block. The `inp' parameter must have 1576 * come from the zone allocator set up in tcp_init(). 1577 */ 1578 struct tcpcb * 1579 tcp_newtcpcb(struct inpcb *inp) 1580 { 1581 struct tcpcb_mem *tm; 1582 struct tcpcb *tp; 1583 #ifdef INET6 1584 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1585 #endif /* INET6 */ 1586 1587 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1588 if (tm == NULL) 1589 return (NULL); 1590 tp = &tm->tcb; 1591 1592 /* Initialise cc_var struct for this tcpcb. */ 1593 tp->ccv = &tm->ccv; 1594 tp->ccv->type = IPPROTO_TCP; 1595 tp->ccv->ccvc.tcp = tp; 1596 rw_rlock(&tcp_function_lock); 1597 tp->t_fb = tcp_func_set_ptr; 1598 refcount_acquire(&tp->t_fb->tfb_refcnt); 1599 rw_runlock(&tcp_function_lock); 1600 /* 1601 * Use the current system default CC algorithm. 1602 */ 1603 CC_LIST_RLOCK(); 1604 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1605 CC_ALGO(tp) = CC_DEFAULT(); 1606 CC_LIST_RUNLOCK(); 1607 1608 if (CC_ALGO(tp)->cb_init != NULL) 1609 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1610 if (tp->t_fb->tfb_tcp_fb_fini) 1611 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1612 refcount_release(&tp->t_fb->tfb_refcnt); 1613 uma_zfree(V_tcpcb_zone, tm); 1614 return (NULL); 1615 } 1616 1617 #ifdef TCP_HHOOK 1618 tp->osd = &tm->osd; 1619 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1620 if (tp->t_fb->tfb_tcp_fb_fini) 1621 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1622 refcount_release(&tp->t_fb->tfb_refcnt); 1623 uma_zfree(V_tcpcb_zone, tm); 1624 return (NULL); 1625 } 1626 #endif 1627 1628 #ifdef VIMAGE 1629 tp->t_vnet = inp->inp_vnet; 1630 #endif 1631 tp->t_timers = &tm->tt; 1632 TAILQ_INIT(&tp->t_segq); 1633 tp->t_maxseg = 1634 #ifdef INET6 1635 isipv6 ? V_tcp_v6mssdflt : 1636 #endif /* INET6 */ 1637 V_tcp_mssdflt; 1638 1639 /* Set up our timeouts. */ 1640 callout_init(&tp->t_timers->tt_rexmt, 1); 1641 callout_init(&tp->t_timers->tt_persist, 1); 1642 callout_init(&tp->t_timers->tt_keep, 1); 1643 callout_init(&tp->t_timers->tt_2msl, 1); 1644 callout_init(&tp->t_timers->tt_delack, 1); 1645 1646 if (V_tcp_do_rfc1323) 1647 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1648 if (V_tcp_do_sack) 1649 tp->t_flags |= TF_SACK_PERMIT; 1650 TAILQ_INIT(&tp->snd_holes); 1651 /* 1652 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1653 * is called. 1654 */ 1655 in_pcbref(inp); /* Reference for tcpcb */ 1656 tp->t_inpcb = inp; 1657 1658 /* 1659 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1660 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1661 * reasonable initial retransmit time. 1662 */ 1663 tp->t_srtt = TCPTV_SRTTBASE; 1664 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1665 tp->t_rttmin = tcp_rexmit_min; 1666 tp->t_rxtcur = tcp_rexmit_initial; 1667 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1668 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1669 tp->t_rcvtime = ticks; 1670 /* 1671 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1672 * because the socket may be bound to an IPv6 wildcard address, 1673 * which may match an IPv4-mapped IPv6 address. 1674 */ 1675 inp->inp_ip_ttl = V_ip_defttl; 1676 inp->inp_ppcb = tp; 1677 #ifdef TCPPCAP 1678 /* 1679 * Init the TCP PCAP queues. 1680 */ 1681 tcp_pcap_tcpcb_init(tp); 1682 #endif 1683 #ifdef TCP_BLACKBOX 1684 /* Initialize the per-TCPCB log data. */ 1685 tcp_log_tcpcbinit(tp); 1686 #endif 1687 if (tp->t_fb->tfb_tcp_fb_init) { 1688 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1689 } 1690 return (tp); /* XXX */ 1691 } 1692 1693 /* 1694 * Switch the congestion control algorithm back to NewReno for any active 1695 * control blocks using an algorithm which is about to go away. 1696 * This ensures the CC framework can allow the unload to proceed without leaving 1697 * any dangling pointers which would trigger a panic. 1698 * Returning non-zero would inform the CC framework that something went wrong 1699 * and it would be unsafe to allow the unload to proceed. However, there is no 1700 * way for this to occur with this implementation so we always return zero. 1701 */ 1702 int 1703 tcp_ccalgounload(struct cc_algo *unload_algo) 1704 { 1705 struct cc_algo *tmpalgo; 1706 struct inpcb *inp; 1707 struct tcpcb *tp; 1708 VNET_ITERATOR_DECL(vnet_iter); 1709 1710 /* 1711 * Check all active control blocks across all network stacks and change 1712 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1713 * requires cleanup code to be run, call it. 1714 */ 1715 VNET_LIST_RLOCK(); 1716 VNET_FOREACH(vnet_iter) { 1717 CURVNET_SET(vnet_iter); 1718 INP_INFO_WLOCK(&V_tcbinfo); 1719 /* 1720 * New connections already part way through being initialised 1721 * with the CC algo we're removing will not race with this code 1722 * because the INP_INFO_WLOCK is held during initialisation. We 1723 * therefore don't enter the loop below until the connection 1724 * list has stabilised. 1725 */ 1726 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1727 INP_WLOCK(inp); 1728 /* Important to skip tcptw structs. */ 1729 if (!(inp->inp_flags & INP_TIMEWAIT) && 1730 (tp = intotcpcb(inp)) != NULL) { 1731 /* 1732 * By holding INP_WLOCK here, we are assured 1733 * that the connection is not currently 1734 * executing inside the CC module's functions 1735 * i.e. it is safe to make the switch back to 1736 * NewReno. 1737 */ 1738 if (CC_ALGO(tp) == unload_algo) { 1739 tmpalgo = CC_ALGO(tp); 1740 if (tmpalgo->cb_destroy != NULL) 1741 tmpalgo->cb_destroy(tp->ccv); 1742 CC_DATA(tp) = NULL; 1743 /* 1744 * NewReno may allocate memory on 1745 * demand for certain stateful 1746 * configuration as needed, but is 1747 * coded to never fail on memory 1748 * allocation failure so it is a safe 1749 * fallback. 1750 */ 1751 CC_ALGO(tp) = &newreno_cc_algo; 1752 } 1753 } 1754 INP_WUNLOCK(inp); 1755 } 1756 INP_INFO_WUNLOCK(&V_tcbinfo); 1757 CURVNET_RESTORE(); 1758 } 1759 VNET_LIST_RUNLOCK(); 1760 1761 return (0); 1762 } 1763 1764 /* 1765 * Drop a TCP connection, reporting 1766 * the specified error. If connection is synchronized, 1767 * then send a RST to peer. 1768 */ 1769 struct tcpcb * 1770 tcp_drop(struct tcpcb *tp, int errno) 1771 { 1772 struct socket *so = tp->t_inpcb->inp_socket; 1773 1774 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1775 INP_WLOCK_ASSERT(tp->t_inpcb); 1776 1777 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1778 tcp_state_change(tp, TCPS_CLOSED); 1779 (void) tp->t_fb->tfb_tcp_output(tp); 1780 TCPSTAT_INC(tcps_drops); 1781 } else 1782 TCPSTAT_INC(tcps_conndrops); 1783 if (errno == ETIMEDOUT && tp->t_softerror) 1784 errno = tp->t_softerror; 1785 so->so_error = errno; 1786 return (tcp_close(tp)); 1787 } 1788 1789 void 1790 tcp_discardcb(struct tcpcb *tp) 1791 { 1792 struct inpcb *inp = tp->t_inpcb; 1793 struct socket *so = inp->inp_socket; 1794 #ifdef INET6 1795 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1796 #endif /* INET6 */ 1797 int released __unused; 1798 1799 INP_WLOCK_ASSERT(inp); 1800 1801 /* 1802 * Make sure that all of our timers are stopped before we delete the 1803 * PCB. 1804 * 1805 * If stopping a timer fails, we schedule a discard function in same 1806 * callout, and the last discard function called will take care of 1807 * deleting the tcpcb. 1808 */ 1809 tp->t_timers->tt_draincnt = 0; 1810 tcp_timer_stop(tp, TT_REXMT); 1811 tcp_timer_stop(tp, TT_PERSIST); 1812 tcp_timer_stop(tp, TT_KEEP); 1813 tcp_timer_stop(tp, TT_2MSL); 1814 tcp_timer_stop(tp, TT_DELACK); 1815 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1816 /* 1817 * Call the stop-all function of the methods, 1818 * this function should call the tcp_timer_stop() 1819 * method with each of the function specific timeouts. 1820 * That stop will be called via the tfb_tcp_timer_stop() 1821 * which should use the async drain function of the 1822 * callout system (see tcp_var.h). 1823 */ 1824 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1825 } 1826 1827 /* 1828 * If we got enough samples through the srtt filter, 1829 * save the rtt and rttvar in the routing entry. 1830 * 'Enough' is arbitrarily defined as 4 rtt samples. 1831 * 4 samples is enough for the srtt filter to converge 1832 * to within enough % of the correct value; fewer samples 1833 * and we could save a bogus rtt. The danger is not high 1834 * as tcp quickly recovers from everything. 1835 * XXX: Works very well but needs some more statistics! 1836 */ 1837 if (tp->t_rttupdated >= 4) { 1838 struct hc_metrics_lite metrics; 1839 uint32_t ssthresh; 1840 1841 bzero(&metrics, sizeof(metrics)); 1842 /* 1843 * Update the ssthresh always when the conditions below 1844 * are satisfied. This gives us better new start value 1845 * for the congestion avoidance for new connections. 1846 * ssthresh is only set if packet loss occurred on a session. 1847 * 1848 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1849 * being torn down. Ideally this code would not use 'so'. 1850 */ 1851 ssthresh = tp->snd_ssthresh; 1852 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1853 /* 1854 * convert the limit from user data bytes to 1855 * packets then to packet data bytes. 1856 */ 1857 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1858 if (ssthresh < 2) 1859 ssthresh = 2; 1860 ssthresh *= (tp->t_maxseg + 1861 #ifdef INET6 1862 (isipv6 ? sizeof (struct ip6_hdr) + 1863 sizeof (struct tcphdr) : 1864 #endif 1865 sizeof (struct tcpiphdr) 1866 #ifdef INET6 1867 ) 1868 #endif 1869 ); 1870 } else 1871 ssthresh = 0; 1872 metrics.rmx_ssthresh = ssthresh; 1873 1874 metrics.rmx_rtt = tp->t_srtt; 1875 metrics.rmx_rttvar = tp->t_rttvar; 1876 metrics.rmx_cwnd = tp->snd_cwnd; 1877 metrics.rmx_sendpipe = 0; 1878 metrics.rmx_recvpipe = 0; 1879 1880 tcp_hc_update(&inp->inp_inc, &metrics); 1881 } 1882 1883 /* free the reassembly queue, if any */ 1884 tcp_reass_flush(tp); 1885 1886 #ifdef TCP_OFFLOAD 1887 /* Disconnect offload device, if any. */ 1888 if (tp->t_flags & TF_TOE) 1889 tcp_offload_detach(tp); 1890 #endif 1891 1892 tcp_free_sackholes(tp); 1893 1894 #ifdef TCPPCAP 1895 /* Free the TCP PCAP queues. */ 1896 tcp_pcap_drain(&(tp->t_inpkts)); 1897 tcp_pcap_drain(&(tp->t_outpkts)); 1898 #endif 1899 1900 /* Allow the CC algorithm to clean up after itself. */ 1901 if (CC_ALGO(tp)->cb_destroy != NULL) 1902 CC_ALGO(tp)->cb_destroy(tp->ccv); 1903 CC_DATA(tp) = NULL; 1904 1905 #ifdef TCP_HHOOK 1906 khelp_destroy_osd(tp->osd); 1907 #endif 1908 1909 CC_ALGO(tp) = NULL; 1910 inp->inp_ppcb = NULL; 1911 if (tp->t_timers->tt_draincnt == 0) { 1912 /* We own the last reference on tcpcb, let's free it. */ 1913 #ifdef TCP_BLACKBOX 1914 tcp_log_tcpcbfini(tp); 1915 #endif 1916 TCPSTATES_DEC(tp->t_state); 1917 if (tp->t_fb->tfb_tcp_fb_fini) 1918 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1919 refcount_release(&tp->t_fb->tfb_refcnt); 1920 tp->t_inpcb = NULL; 1921 uma_zfree(V_tcpcb_zone, tp); 1922 released = in_pcbrele_wlocked(inp); 1923 KASSERT(!released, ("%s: inp %p should not have been released " 1924 "here", __func__, inp)); 1925 } 1926 } 1927 1928 void 1929 tcp_timer_discard(void *ptp) 1930 { 1931 struct inpcb *inp; 1932 struct tcpcb *tp; 1933 struct epoch_tracker et; 1934 1935 tp = (struct tcpcb *)ptp; 1936 CURVNET_SET(tp->t_vnet); 1937 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 1938 inp = tp->t_inpcb; 1939 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1940 __func__, tp)); 1941 INP_WLOCK(inp); 1942 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1943 ("%s: tcpcb has to be stopped here", __func__)); 1944 tp->t_timers->tt_draincnt--; 1945 if (tp->t_timers->tt_draincnt == 0) { 1946 /* We own the last reference on this tcpcb, let's free it. */ 1947 #ifdef TCP_BLACKBOX 1948 tcp_log_tcpcbfini(tp); 1949 #endif 1950 TCPSTATES_DEC(tp->t_state); 1951 if (tp->t_fb->tfb_tcp_fb_fini) 1952 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1953 refcount_release(&tp->t_fb->tfb_refcnt); 1954 tp->t_inpcb = NULL; 1955 uma_zfree(V_tcpcb_zone, tp); 1956 if (in_pcbrele_wlocked(inp)) { 1957 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1958 CURVNET_RESTORE(); 1959 return; 1960 } 1961 } 1962 INP_WUNLOCK(inp); 1963 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 1964 CURVNET_RESTORE(); 1965 } 1966 1967 /* 1968 * Attempt to close a TCP control block, marking it as dropped, and freeing 1969 * the socket if we hold the only reference. 1970 */ 1971 struct tcpcb * 1972 tcp_close(struct tcpcb *tp) 1973 { 1974 struct inpcb *inp = tp->t_inpcb; 1975 struct socket *so; 1976 1977 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1978 INP_WLOCK_ASSERT(inp); 1979 1980 #ifdef TCP_OFFLOAD 1981 if (tp->t_state == TCPS_LISTEN) 1982 tcp_offload_listen_stop(tp); 1983 #endif 1984 /* 1985 * This releases the TFO pending counter resource for TFO listen 1986 * sockets as well as passively-created TFO sockets that transition 1987 * from SYN_RECEIVED to CLOSED. 1988 */ 1989 if (tp->t_tfo_pending) { 1990 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1991 tp->t_tfo_pending = NULL; 1992 } 1993 in_pcbdrop(inp); 1994 TCPSTAT_INC(tcps_closed); 1995 if (tp->t_state != TCPS_CLOSED) 1996 tcp_state_change(tp, TCPS_CLOSED); 1997 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1998 so = inp->inp_socket; 1999 soisdisconnected(so); 2000 if (inp->inp_flags & INP_SOCKREF) { 2001 KASSERT(so->so_state & SS_PROTOREF, 2002 ("tcp_close: !SS_PROTOREF")); 2003 inp->inp_flags &= ~INP_SOCKREF; 2004 INP_WUNLOCK(inp); 2005 SOCK_LOCK(so); 2006 so->so_state &= ~SS_PROTOREF; 2007 sofree(so); 2008 return (NULL); 2009 } 2010 return (tp); 2011 } 2012 2013 void 2014 tcp_drain(void) 2015 { 2016 VNET_ITERATOR_DECL(vnet_iter); 2017 2018 if (!do_tcpdrain) 2019 return; 2020 2021 VNET_LIST_RLOCK_NOSLEEP(); 2022 VNET_FOREACH(vnet_iter) { 2023 CURVNET_SET(vnet_iter); 2024 struct inpcb *inpb; 2025 struct tcpcb *tcpb; 2026 2027 /* 2028 * Walk the tcpbs, if existing, and flush the reassembly queue, 2029 * if there is one... 2030 * XXX: The "Net/3" implementation doesn't imply that the TCP 2031 * reassembly queue should be flushed, but in a situation 2032 * where we're really low on mbufs, this is potentially 2033 * useful. 2034 */ 2035 INP_INFO_WLOCK(&V_tcbinfo); 2036 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2037 INP_WLOCK(inpb); 2038 if (inpb->inp_flags & INP_TIMEWAIT) { 2039 INP_WUNLOCK(inpb); 2040 continue; 2041 } 2042 if ((tcpb = intotcpcb(inpb)) != NULL) { 2043 tcp_reass_flush(tcpb); 2044 tcp_clean_sackreport(tcpb); 2045 #ifdef TCP_BLACKBOX 2046 tcp_log_drain(tcpb); 2047 #endif 2048 #ifdef TCPPCAP 2049 if (tcp_pcap_aggressive_free) { 2050 /* Free the TCP PCAP queues. */ 2051 tcp_pcap_drain(&(tcpb->t_inpkts)); 2052 tcp_pcap_drain(&(tcpb->t_outpkts)); 2053 } 2054 #endif 2055 } 2056 INP_WUNLOCK(inpb); 2057 } 2058 INP_INFO_WUNLOCK(&V_tcbinfo); 2059 CURVNET_RESTORE(); 2060 } 2061 VNET_LIST_RUNLOCK_NOSLEEP(); 2062 } 2063 2064 /* 2065 * Notify a tcp user of an asynchronous error; 2066 * store error as soft error, but wake up user 2067 * (for now, won't do anything until can select for soft error). 2068 * 2069 * Do not wake up user since there currently is no mechanism for 2070 * reporting soft errors (yet - a kqueue filter may be added). 2071 */ 2072 static struct inpcb * 2073 tcp_notify(struct inpcb *inp, int error) 2074 { 2075 struct tcpcb *tp; 2076 2077 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2078 INP_WLOCK_ASSERT(inp); 2079 2080 if ((inp->inp_flags & INP_TIMEWAIT) || 2081 (inp->inp_flags & INP_DROPPED)) 2082 return (inp); 2083 2084 tp = intotcpcb(inp); 2085 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2086 2087 /* 2088 * Ignore some errors if we are hooked up. 2089 * If connection hasn't completed, has retransmitted several times, 2090 * and receives a second error, give up now. This is better 2091 * than waiting a long time to establish a connection that 2092 * can never complete. 2093 */ 2094 if (tp->t_state == TCPS_ESTABLISHED && 2095 (error == EHOSTUNREACH || error == ENETUNREACH || 2096 error == EHOSTDOWN)) { 2097 if (inp->inp_route.ro_rt) { 2098 RTFREE(inp->inp_route.ro_rt); 2099 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2100 } 2101 return (inp); 2102 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2103 tp->t_softerror) { 2104 tp = tcp_drop(tp, error); 2105 if (tp != NULL) 2106 return (inp); 2107 else 2108 return (NULL); 2109 } else { 2110 tp->t_softerror = error; 2111 return (inp); 2112 } 2113 #if 0 2114 wakeup( &so->so_timeo); 2115 sorwakeup(so); 2116 sowwakeup(so); 2117 #endif 2118 } 2119 2120 static int 2121 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2122 { 2123 int error, i, m, n, pcb_count; 2124 struct inpcb *inp, **inp_list; 2125 inp_gen_t gencnt; 2126 struct xinpgen xig; 2127 struct epoch_tracker et; 2128 2129 /* 2130 * The process of preparing the TCB list is too time-consuming and 2131 * resource-intensive to repeat twice on every request. 2132 */ 2133 if (req->oldptr == NULL) { 2134 n = V_tcbinfo.ipi_count + 2135 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2136 n += imax(n / 8, 10); 2137 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2138 return (0); 2139 } 2140 2141 if (req->newptr != NULL) 2142 return (EPERM); 2143 2144 /* 2145 * OK, now we're committed to doing something. 2146 */ 2147 INP_LIST_RLOCK(&V_tcbinfo); 2148 gencnt = V_tcbinfo.ipi_gencnt; 2149 n = V_tcbinfo.ipi_count; 2150 INP_LIST_RUNLOCK(&V_tcbinfo); 2151 2152 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2153 2154 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 2155 + (n + m) * sizeof(struct xtcpcb)); 2156 if (error != 0) 2157 return (error); 2158 2159 bzero(&xig, sizeof(xig)); 2160 xig.xig_len = sizeof xig; 2161 xig.xig_count = n + m; 2162 xig.xig_gen = gencnt; 2163 xig.xig_sogen = so_gencnt; 2164 error = SYSCTL_OUT(req, &xig, sizeof xig); 2165 if (error) 2166 return (error); 2167 2168 error = syncache_pcblist(req, m, &pcb_count); 2169 if (error) 2170 return (error); 2171 2172 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 2173 2174 INP_INFO_WLOCK(&V_tcbinfo); 2175 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 2176 inp != NULL && i < n; inp = CK_LIST_NEXT(inp, inp_list)) { 2177 INP_WLOCK(inp); 2178 if (inp->inp_gencnt <= gencnt) { 2179 /* 2180 * XXX: This use of cr_cansee(), introduced with 2181 * TCP state changes, is not quite right, but for 2182 * now, better than nothing. 2183 */ 2184 if (inp->inp_flags & INP_TIMEWAIT) { 2185 if (intotw(inp) != NULL) 2186 error = cr_cansee(req->td->td_ucred, 2187 intotw(inp)->tw_cred); 2188 else 2189 error = EINVAL; /* Skip this inp. */ 2190 } else 2191 error = cr_canseeinpcb(req->td->td_ucred, inp); 2192 if (error == 0) { 2193 in_pcbref(inp); 2194 inp_list[i++] = inp; 2195 } 2196 } 2197 INP_WUNLOCK(inp); 2198 } 2199 INP_INFO_WUNLOCK(&V_tcbinfo); 2200 n = i; 2201 2202 error = 0; 2203 for (i = 0; i < n; i++) { 2204 inp = inp_list[i]; 2205 INP_RLOCK(inp); 2206 if (inp->inp_gencnt <= gencnt) { 2207 struct xtcpcb xt; 2208 2209 tcp_inptoxtp(inp, &xt); 2210 INP_RUNLOCK(inp); 2211 error = SYSCTL_OUT(req, &xt, sizeof xt); 2212 } else 2213 INP_RUNLOCK(inp); 2214 } 2215 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2216 for (i = 0; i < n; i++) { 2217 inp = inp_list[i]; 2218 INP_RLOCK(inp); 2219 if (!in_pcbrele_rlocked(inp)) 2220 INP_RUNLOCK(inp); 2221 } 2222 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2223 2224 if (!error) { 2225 /* 2226 * Give the user an updated idea of our state. 2227 * If the generation differs from what we told 2228 * her before, she knows that something happened 2229 * while we were processing this request, and it 2230 * might be necessary to retry. 2231 */ 2232 INP_LIST_RLOCK(&V_tcbinfo); 2233 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2234 xig.xig_sogen = so_gencnt; 2235 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 2236 INP_LIST_RUNLOCK(&V_tcbinfo); 2237 error = SYSCTL_OUT(req, &xig, sizeof xig); 2238 } 2239 free(inp_list, M_TEMP); 2240 return (error); 2241 } 2242 2243 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2244 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2245 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2246 2247 #ifdef INET 2248 static int 2249 tcp_getcred(SYSCTL_HANDLER_ARGS) 2250 { 2251 struct xucred xuc; 2252 struct sockaddr_in addrs[2]; 2253 struct inpcb *inp; 2254 int error; 2255 2256 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2257 if (error) 2258 return (error); 2259 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2260 if (error) 2261 return (error); 2262 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2263 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2264 if (inp != NULL) { 2265 if (inp->inp_socket == NULL) 2266 error = ENOENT; 2267 if (error == 0) 2268 error = cr_canseeinpcb(req->td->td_ucred, inp); 2269 if (error == 0) 2270 cru2x(inp->inp_cred, &xuc); 2271 INP_RUNLOCK(inp); 2272 } else 2273 error = ENOENT; 2274 if (error == 0) 2275 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2276 return (error); 2277 } 2278 2279 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2280 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2281 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2282 #endif /* INET */ 2283 2284 #ifdef INET6 2285 static int 2286 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2287 { 2288 struct xucred xuc; 2289 struct sockaddr_in6 addrs[2]; 2290 struct inpcb *inp; 2291 int error; 2292 #ifdef INET 2293 int mapped = 0; 2294 #endif 2295 2296 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2297 if (error) 2298 return (error); 2299 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2300 if (error) 2301 return (error); 2302 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2303 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2304 return (error); 2305 } 2306 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2307 #ifdef INET 2308 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2309 mapped = 1; 2310 else 2311 #endif 2312 return (EINVAL); 2313 } 2314 2315 #ifdef INET 2316 if (mapped == 1) 2317 inp = in_pcblookup(&V_tcbinfo, 2318 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2319 addrs[1].sin6_port, 2320 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2321 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2322 else 2323 #endif 2324 inp = in6_pcblookup(&V_tcbinfo, 2325 &addrs[1].sin6_addr, addrs[1].sin6_port, 2326 &addrs[0].sin6_addr, addrs[0].sin6_port, 2327 INPLOOKUP_RLOCKPCB, NULL); 2328 if (inp != NULL) { 2329 if (inp->inp_socket == NULL) 2330 error = ENOENT; 2331 if (error == 0) 2332 error = cr_canseeinpcb(req->td->td_ucred, inp); 2333 if (error == 0) 2334 cru2x(inp->inp_cred, &xuc); 2335 INP_RUNLOCK(inp); 2336 } else 2337 error = ENOENT; 2338 if (error == 0) 2339 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2340 return (error); 2341 } 2342 2343 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2344 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2345 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2346 #endif /* INET6 */ 2347 2348 2349 #ifdef INET 2350 void 2351 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2352 { 2353 struct ip *ip = vip; 2354 struct tcphdr *th; 2355 struct in_addr faddr; 2356 struct inpcb *inp; 2357 struct tcpcb *tp; 2358 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2359 struct icmp *icp; 2360 struct in_conninfo inc; 2361 struct epoch_tracker et; 2362 tcp_seq icmp_tcp_seq; 2363 int mtu; 2364 2365 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2366 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2367 return; 2368 2369 if (cmd == PRC_MSGSIZE) 2370 notify = tcp_mtudisc_notify; 2371 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2372 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2373 cmd == PRC_TIMXCEED_INTRANS) && ip) 2374 notify = tcp_drop_syn_sent; 2375 2376 /* 2377 * Hostdead is ugly because it goes linearly through all PCBs. 2378 * XXX: We never get this from ICMP, otherwise it makes an 2379 * excellent DoS attack on machines with many connections. 2380 */ 2381 else if (cmd == PRC_HOSTDEAD) 2382 ip = NULL; 2383 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2384 return; 2385 2386 if (ip == NULL) { 2387 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2388 return; 2389 } 2390 2391 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2392 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2393 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2394 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2395 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2396 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2397 /* signal EHOSTDOWN, as it flushes the cached route */ 2398 inp = (*notify)(inp, EHOSTDOWN); 2399 goto out; 2400 } 2401 icmp_tcp_seq = th->th_seq; 2402 if (inp != NULL) { 2403 if (!(inp->inp_flags & INP_TIMEWAIT) && 2404 !(inp->inp_flags & INP_DROPPED) && 2405 !(inp->inp_socket == NULL)) { 2406 tp = intotcpcb(inp); 2407 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2408 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2409 if (cmd == PRC_MSGSIZE) { 2410 /* 2411 * MTU discovery: 2412 * If we got a needfrag set the MTU 2413 * in the route to the suggested new 2414 * value (if given) and then notify. 2415 */ 2416 mtu = ntohs(icp->icmp_nextmtu); 2417 /* 2418 * If no alternative MTU was 2419 * proposed, try the next smaller 2420 * one. 2421 */ 2422 if (!mtu) 2423 mtu = ip_next_mtu( 2424 ntohs(ip->ip_len), 1); 2425 if (mtu < V_tcp_minmss + 2426 sizeof(struct tcpiphdr)) 2427 mtu = V_tcp_minmss + 2428 sizeof(struct tcpiphdr); 2429 /* 2430 * Only process the offered MTU if it 2431 * is smaller than the current one. 2432 */ 2433 if (mtu < tp->t_maxseg + 2434 sizeof(struct tcpiphdr)) { 2435 bzero(&inc, sizeof(inc)); 2436 inc.inc_faddr = faddr; 2437 inc.inc_fibnum = 2438 inp->inp_inc.inc_fibnum; 2439 tcp_hc_updatemtu(&inc, mtu); 2440 tcp_mtudisc(inp, mtu); 2441 } 2442 } else 2443 inp = (*notify)(inp, 2444 inetctlerrmap[cmd]); 2445 } 2446 } 2447 } else { 2448 bzero(&inc, sizeof(inc)); 2449 inc.inc_fport = th->th_dport; 2450 inc.inc_lport = th->th_sport; 2451 inc.inc_faddr = faddr; 2452 inc.inc_laddr = ip->ip_src; 2453 syncache_unreach(&inc, icmp_tcp_seq); 2454 } 2455 out: 2456 if (inp != NULL) 2457 INP_WUNLOCK(inp); 2458 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2459 } 2460 #endif /* INET */ 2461 2462 #ifdef INET6 2463 void 2464 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2465 { 2466 struct in6_addr *dst; 2467 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2468 struct ip6_hdr *ip6; 2469 struct mbuf *m; 2470 struct inpcb *inp; 2471 struct tcpcb *tp; 2472 struct icmp6_hdr *icmp6; 2473 struct ip6ctlparam *ip6cp = NULL; 2474 const struct sockaddr_in6 *sa6_src = NULL; 2475 struct in_conninfo inc; 2476 struct epoch_tracker et; 2477 struct tcp_ports { 2478 uint16_t th_sport; 2479 uint16_t th_dport; 2480 } t_ports; 2481 tcp_seq icmp_tcp_seq; 2482 unsigned int mtu; 2483 unsigned int off; 2484 2485 if (sa->sa_family != AF_INET6 || 2486 sa->sa_len != sizeof(struct sockaddr_in6)) 2487 return; 2488 2489 /* if the parameter is from icmp6, decode it. */ 2490 if (d != NULL) { 2491 ip6cp = (struct ip6ctlparam *)d; 2492 icmp6 = ip6cp->ip6c_icmp6; 2493 m = ip6cp->ip6c_m; 2494 ip6 = ip6cp->ip6c_ip6; 2495 off = ip6cp->ip6c_off; 2496 sa6_src = ip6cp->ip6c_src; 2497 dst = ip6cp->ip6c_finaldst; 2498 } else { 2499 m = NULL; 2500 ip6 = NULL; 2501 off = 0; /* fool gcc */ 2502 sa6_src = &sa6_any; 2503 dst = NULL; 2504 } 2505 2506 if (cmd == PRC_MSGSIZE) 2507 notify = tcp_mtudisc_notify; 2508 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2509 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2510 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2511 notify = tcp_drop_syn_sent; 2512 2513 /* 2514 * Hostdead is ugly because it goes linearly through all PCBs. 2515 * XXX: We never get this from ICMP, otherwise it makes an 2516 * excellent DoS attack on machines with many connections. 2517 */ 2518 else if (cmd == PRC_HOSTDEAD) 2519 ip6 = NULL; 2520 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2521 return; 2522 2523 if (ip6 == NULL) { 2524 in6_pcbnotify(&V_tcbinfo, sa, 0, 2525 (const struct sockaddr *)sa6_src, 2526 0, cmd, NULL, notify); 2527 return; 2528 } 2529 2530 /* Check if we can safely get the ports from the tcp hdr */ 2531 if (m == NULL || 2532 (m->m_pkthdr.len < 2533 (int32_t) (off + sizeof(struct tcp_ports)))) { 2534 return; 2535 } 2536 bzero(&t_ports, sizeof(struct tcp_ports)); 2537 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2538 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 2539 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2540 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2541 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2542 /* signal EHOSTDOWN, as it flushes the cached route */ 2543 inp = (*notify)(inp, EHOSTDOWN); 2544 goto out; 2545 } 2546 off += sizeof(struct tcp_ports); 2547 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2548 goto out; 2549 } 2550 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2551 if (inp != NULL) { 2552 if (!(inp->inp_flags & INP_TIMEWAIT) && 2553 !(inp->inp_flags & INP_DROPPED) && 2554 !(inp->inp_socket == NULL)) { 2555 tp = intotcpcb(inp); 2556 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2557 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2558 if (cmd == PRC_MSGSIZE) { 2559 /* 2560 * MTU discovery: 2561 * If we got a needfrag set the MTU 2562 * in the route to the suggested new 2563 * value (if given) and then notify. 2564 */ 2565 mtu = ntohl(icmp6->icmp6_mtu); 2566 /* 2567 * If no alternative MTU was 2568 * proposed, or the proposed 2569 * MTU was too small, set to 2570 * the min. 2571 */ 2572 if (mtu < IPV6_MMTU) 2573 mtu = IPV6_MMTU - 8; 2574 bzero(&inc, sizeof(inc)); 2575 inc.inc_fibnum = M_GETFIB(m); 2576 inc.inc_flags |= INC_ISIPV6; 2577 inc.inc6_faddr = *dst; 2578 if (in6_setscope(&inc.inc6_faddr, 2579 m->m_pkthdr.rcvif, NULL)) 2580 goto out; 2581 /* 2582 * Only process the offered MTU if it 2583 * is smaller than the current one. 2584 */ 2585 if (mtu < tp->t_maxseg + 2586 sizeof (struct tcphdr) + 2587 sizeof (struct ip6_hdr)) { 2588 tcp_hc_updatemtu(&inc, mtu); 2589 tcp_mtudisc(inp, mtu); 2590 ICMP6STAT_INC(icp6s_pmtuchg); 2591 } 2592 } else 2593 inp = (*notify)(inp, 2594 inet6ctlerrmap[cmd]); 2595 } 2596 } 2597 } else { 2598 bzero(&inc, sizeof(inc)); 2599 inc.inc_fibnum = M_GETFIB(m); 2600 inc.inc_flags |= INC_ISIPV6; 2601 inc.inc_fport = t_ports.th_dport; 2602 inc.inc_lport = t_ports.th_sport; 2603 inc.inc6_faddr = *dst; 2604 inc.inc6_laddr = ip6->ip6_src; 2605 syncache_unreach(&inc, icmp_tcp_seq); 2606 } 2607 out: 2608 if (inp != NULL) 2609 INP_WUNLOCK(inp); 2610 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 2611 } 2612 #endif /* INET6 */ 2613 2614 static uint32_t 2615 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2616 { 2617 MD5_CTX ctx; 2618 uint32_t hash[4]; 2619 2620 MD5Init(&ctx); 2621 MD5Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2622 MD5Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2623 switch (inc->inc_flags & INC_ISIPV6) { 2624 #ifdef INET 2625 case 0: 2626 MD5Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2627 MD5Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2628 break; 2629 #endif 2630 #ifdef INET6 2631 case INC_ISIPV6: 2632 MD5Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2633 MD5Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2634 break; 2635 #endif 2636 } 2637 MD5Update(&ctx, key, len); 2638 MD5Final((unsigned char *)hash, &ctx); 2639 2640 return (hash[0]); 2641 } 2642 2643 uint32_t 2644 tcp_new_ts_offset(struct in_conninfo *inc) 2645 { 2646 struct in_conninfo inc_store, *local_inc; 2647 2648 if (!V_tcp_ts_offset_per_conn) { 2649 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 2650 inc_store.inc_lport = 0; 2651 inc_store.inc_fport = 0; 2652 local_inc = &inc_store; 2653 } else { 2654 local_inc = inc; 2655 } 2656 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 2657 sizeof(V_ts_offset_secret))); 2658 } 2659 2660 /* 2661 * Following is where TCP initial sequence number generation occurs. 2662 * 2663 * There are two places where we must use initial sequence numbers: 2664 * 1. In SYN-ACK packets. 2665 * 2. In SYN packets. 2666 * 2667 * All ISNs for SYN-ACK packets are generated by the syncache. See 2668 * tcp_syncache.c for details. 2669 * 2670 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2671 * depends on this property. In addition, these ISNs should be 2672 * unguessable so as to prevent connection hijacking. To satisfy 2673 * the requirements of this situation, the algorithm outlined in 2674 * RFC 1948 is used, with only small modifications. 2675 * 2676 * Implementation details: 2677 * 2678 * Time is based off the system timer, and is corrected so that it 2679 * increases by one megabyte per second. This allows for proper 2680 * recycling on high speed LANs while still leaving over an hour 2681 * before rollover. 2682 * 2683 * As reading the *exact* system time is too expensive to be done 2684 * whenever setting up a TCP connection, we increment the time 2685 * offset in two ways. First, a small random positive increment 2686 * is added to isn_offset for each connection that is set up. 2687 * Second, the function tcp_isn_tick fires once per clock tick 2688 * and increments isn_offset as necessary so that sequence numbers 2689 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2690 * random positive increments serve only to ensure that the same 2691 * exact sequence number is never sent out twice (as could otherwise 2692 * happen when a port is recycled in less than the system tick 2693 * interval.) 2694 * 2695 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2696 * between seeding of isn_secret. This is normally set to zero, 2697 * as reseeding should not be necessary. 2698 * 2699 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2700 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2701 * general, this means holding an exclusive (write) lock. 2702 */ 2703 2704 #define ISN_BYTES_PER_SECOND 1048576 2705 #define ISN_STATIC_INCREMENT 4096 2706 #define ISN_RANDOM_INCREMENT (4096 - 1) 2707 #define ISN_SECRET_LENGTH 32 2708 2709 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2710 VNET_DEFINE_STATIC(int, isn_last); 2711 VNET_DEFINE_STATIC(int, isn_last_reseed); 2712 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2713 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2714 2715 #define V_isn_secret VNET(isn_secret) 2716 #define V_isn_last VNET(isn_last) 2717 #define V_isn_last_reseed VNET(isn_last_reseed) 2718 #define V_isn_offset VNET(isn_offset) 2719 #define V_isn_offset_old VNET(isn_offset_old) 2720 2721 tcp_seq 2722 tcp_new_isn(struct in_conninfo *inc) 2723 { 2724 tcp_seq new_isn; 2725 u_int32_t projected_offset; 2726 2727 ISN_LOCK(); 2728 /* Seed if this is the first use, reseed if requested. */ 2729 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2730 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2731 < (u_int)ticks))) { 2732 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2733 V_isn_last_reseed = ticks; 2734 } 2735 2736 /* Compute the md5 hash and return the ISN. */ 2737 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2738 sizeof(V_isn_secret)); 2739 V_isn_offset += ISN_STATIC_INCREMENT + 2740 (arc4random() & ISN_RANDOM_INCREMENT); 2741 if (ticks != V_isn_last) { 2742 projected_offset = V_isn_offset_old + 2743 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2744 if (SEQ_GT(projected_offset, V_isn_offset)) 2745 V_isn_offset = projected_offset; 2746 V_isn_offset_old = V_isn_offset; 2747 V_isn_last = ticks; 2748 } 2749 new_isn += V_isn_offset; 2750 ISN_UNLOCK(); 2751 return (new_isn); 2752 } 2753 2754 /* 2755 * When a specific ICMP unreachable message is received and the 2756 * connection state is SYN-SENT, drop the connection. This behavior 2757 * is controlled by the icmp_may_rst sysctl. 2758 */ 2759 struct inpcb * 2760 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2761 { 2762 struct tcpcb *tp; 2763 2764 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2765 INP_WLOCK_ASSERT(inp); 2766 2767 if ((inp->inp_flags & INP_TIMEWAIT) || 2768 (inp->inp_flags & INP_DROPPED)) 2769 return (inp); 2770 2771 tp = intotcpcb(inp); 2772 if (tp->t_state != TCPS_SYN_SENT) 2773 return (inp); 2774 2775 if (IS_FASTOPEN(tp->t_flags)) 2776 tcp_fastopen_disable_path(tp); 2777 2778 tp = tcp_drop(tp, errno); 2779 if (tp != NULL) 2780 return (inp); 2781 else 2782 return (NULL); 2783 } 2784 2785 /* 2786 * When `need fragmentation' ICMP is received, update our idea of the MSS 2787 * based on the new value. Also nudge TCP to send something, since we 2788 * know the packet we just sent was dropped. 2789 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2790 */ 2791 static struct inpcb * 2792 tcp_mtudisc_notify(struct inpcb *inp, int error) 2793 { 2794 2795 tcp_mtudisc(inp, -1); 2796 return (inp); 2797 } 2798 2799 static void 2800 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2801 { 2802 struct tcpcb *tp; 2803 struct socket *so; 2804 2805 INP_WLOCK_ASSERT(inp); 2806 if ((inp->inp_flags & INP_TIMEWAIT) || 2807 (inp->inp_flags & INP_DROPPED)) 2808 return; 2809 2810 tp = intotcpcb(inp); 2811 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2812 2813 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2814 2815 so = inp->inp_socket; 2816 SOCKBUF_LOCK(&so->so_snd); 2817 /* If the mss is larger than the socket buffer, decrease the mss. */ 2818 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2819 tp->t_maxseg = so->so_snd.sb_hiwat; 2820 SOCKBUF_UNLOCK(&so->so_snd); 2821 2822 TCPSTAT_INC(tcps_mturesent); 2823 tp->t_rtttime = 0; 2824 tp->snd_nxt = tp->snd_una; 2825 tcp_free_sackholes(tp); 2826 tp->snd_recover = tp->snd_max; 2827 if (tp->t_flags & TF_SACK_PERMIT) 2828 EXIT_FASTRECOVERY(tp->t_flags); 2829 tp->t_fb->tfb_tcp_output(tp); 2830 } 2831 2832 #ifdef INET 2833 /* 2834 * Look-up the routing entry to the peer of this inpcb. If no route 2835 * is found and it cannot be allocated, then return 0. This routine 2836 * is called by TCP routines that access the rmx structure and by 2837 * tcp_mss_update to get the peer/interface MTU. 2838 */ 2839 uint32_t 2840 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2841 { 2842 struct nhop4_extended nh4; 2843 struct ifnet *ifp; 2844 uint32_t maxmtu = 0; 2845 2846 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2847 2848 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2849 2850 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2851 NHR_REF, 0, &nh4) != 0) 2852 return (0); 2853 2854 ifp = nh4.nh_ifp; 2855 maxmtu = nh4.nh_mtu; 2856 2857 /* Report additional interface capabilities. */ 2858 if (cap != NULL) { 2859 if (ifp->if_capenable & IFCAP_TSO4 && 2860 ifp->if_hwassist & CSUM_TSO) { 2861 cap->ifcap |= CSUM_TSO; 2862 cap->tsomax = ifp->if_hw_tsomax; 2863 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2864 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2865 } 2866 } 2867 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2868 } 2869 return (maxmtu); 2870 } 2871 #endif /* INET */ 2872 2873 #ifdef INET6 2874 uint32_t 2875 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2876 { 2877 struct nhop6_extended nh6; 2878 struct in6_addr dst6; 2879 uint32_t scopeid; 2880 struct ifnet *ifp; 2881 uint32_t maxmtu = 0; 2882 2883 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2884 2885 if (inc->inc_flags & INC_IPV6MINMTU) 2886 return (IPV6_MMTU); 2887 2888 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2889 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2890 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2891 0, &nh6) != 0) 2892 return (0); 2893 2894 ifp = nh6.nh_ifp; 2895 maxmtu = nh6.nh_mtu; 2896 2897 /* Report additional interface capabilities. */ 2898 if (cap != NULL) { 2899 if (ifp->if_capenable & IFCAP_TSO6 && 2900 ifp->if_hwassist & CSUM_TSO) { 2901 cap->ifcap |= CSUM_TSO; 2902 cap->tsomax = ifp->if_hw_tsomax; 2903 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2904 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2905 } 2906 } 2907 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2908 } 2909 2910 return (maxmtu); 2911 } 2912 #endif /* INET6 */ 2913 2914 /* 2915 * Calculate effective SMSS per RFC5681 definition for a given TCP 2916 * connection at its current state, taking into account SACK and etc. 2917 */ 2918 u_int 2919 tcp_maxseg(const struct tcpcb *tp) 2920 { 2921 u_int optlen; 2922 2923 if (tp->t_flags & TF_NOOPT) 2924 return (tp->t_maxseg); 2925 2926 /* 2927 * Here we have a simplified code from tcp_addoptions(), 2928 * without a proper loop, and having most of paddings hardcoded. 2929 * We might make mistakes with padding here in some edge cases, 2930 * but this is harmless, since result of tcp_maxseg() is used 2931 * only in cwnd and ssthresh estimations. 2932 */ 2933 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2934 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2935 if (tp->t_flags & TF_RCVD_TSTMP) 2936 optlen = TCPOLEN_TSTAMP_APPA; 2937 else 2938 optlen = 0; 2939 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2940 if (tp->t_flags & TF_SIGNATURE) 2941 optlen += PAD(TCPOLEN_SIGNATURE); 2942 #endif 2943 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2944 optlen += TCPOLEN_SACKHDR; 2945 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2946 optlen = PAD(optlen); 2947 } 2948 } else { 2949 if (tp->t_flags & TF_REQ_TSTMP) 2950 optlen = TCPOLEN_TSTAMP_APPA; 2951 else 2952 optlen = PAD(TCPOLEN_MAXSEG); 2953 if (tp->t_flags & TF_REQ_SCALE) 2954 optlen += PAD(TCPOLEN_WINDOW); 2955 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2956 if (tp->t_flags & TF_SIGNATURE) 2957 optlen += PAD(TCPOLEN_SIGNATURE); 2958 #endif 2959 if (tp->t_flags & TF_SACK_PERMIT) 2960 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2961 } 2962 #undef PAD 2963 optlen = min(optlen, TCP_MAXOLEN); 2964 return (tp->t_maxseg - optlen); 2965 } 2966 2967 static int 2968 sysctl_drop(SYSCTL_HANDLER_ARGS) 2969 { 2970 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2971 struct sockaddr_storage addrs[2]; 2972 struct inpcb *inp; 2973 struct tcpcb *tp; 2974 struct tcptw *tw; 2975 struct sockaddr_in *fin, *lin; 2976 struct epoch_tracker et; 2977 #ifdef INET6 2978 struct sockaddr_in6 *fin6, *lin6; 2979 #endif 2980 int error; 2981 2982 inp = NULL; 2983 fin = lin = NULL; 2984 #ifdef INET6 2985 fin6 = lin6 = NULL; 2986 #endif 2987 error = 0; 2988 2989 if (req->oldptr != NULL || req->oldlen != 0) 2990 return (EINVAL); 2991 if (req->newptr == NULL) 2992 return (EPERM); 2993 if (req->newlen < sizeof(addrs)) 2994 return (ENOMEM); 2995 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2996 if (error) 2997 return (error); 2998 2999 switch (addrs[0].ss_family) { 3000 #ifdef INET6 3001 case AF_INET6: 3002 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3003 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3004 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3005 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3006 return (EINVAL); 3007 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3008 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3009 return (EINVAL); 3010 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3011 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3012 fin = (struct sockaddr_in *)&addrs[0]; 3013 lin = (struct sockaddr_in *)&addrs[1]; 3014 break; 3015 } 3016 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3017 if (error) 3018 return (error); 3019 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3020 if (error) 3021 return (error); 3022 break; 3023 #endif 3024 #ifdef INET 3025 case AF_INET: 3026 fin = (struct sockaddr_in *)&addrs[0]; 3027 lin = (struct sockaddr_in *)&addrs[1]; 3028 if (fin->sin_len != sizeof(struct sockaddr_in) || 3029 lin->sin_len != sizeof(struct sockaddr_in)) 3030 return (EINVAL); 3031 break; 3032 #endif 3033 default: 3034 return (EINVAL); 3035 } 3036 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3037 switch (addrs[0].ss_family) { 3038 #ifdef INET6 3039 case AF_INET6: 3040 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3041 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3042 INPLOOKUP_WLOCKPCB, NULL); 3043 break; 3044 #endif 3045 #ifdef INET 3046 case AF_INET: 3047 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3048 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3049 break; 3050 #endif 3051 } 3052 if (inp != NULL) { 3053 if (inp->inp_flags & INP_TIMEWAIT) { 3054 /* 3055 * XXXRW: There currently exists a state where an 3056 * inpcb is present, but its timewait state has been 3057 * discarded. For now, don't allow dropping of this 3058 * type of inpcb. 3059 */ 3060 tw = intotw(inp); 3061 if (tw != NULL) 3062 tcp_twclose(tw, 0); 3063 else 3064 INP_WUNLOCK(inp); 3065 } else if (!(inp->inp_flags & INP_DROPPED) && 3066 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3067 tp = intotcpcb(inp); 3068 tp = tcp_drop(tp, ECONNABORTED); 3069 if (tp != NULL) 3070 INP_WUNLOCK(inp); 3071 } else 3072 INP_WUNLOCK(inp); 3073 } else 3074 error = ESRCH; 3075 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3076 return (error); 3077 } 3078 3079 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3080 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3081 0, sysctl_drop, "", "Drop TCP connection"); 3082 3083 #ifdef KERN_TLS 3084 static int 3085 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3086 { 3087 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3088 struct sockaddr_storage addrs[2]; 3089 struct inpcb *inp; 3090 struct sockaddr_in *fin, *lin; 3091 struct epoch_tracker et; 3092 #ifdef INET6 3093 struct sockaddr_in6 *fin6, *lin6; 3094 #endif 3095 int error; 3096 3097 inp = NULL; 3098 fin = lin = NULL; 3099 #ifdef INET6 3100 fin6 = lin6 = NULL; 3101 #endif 3102 error = 0; 3103 3104 if (req->oldptr != NULL || req->oldlen != 0) 3105 return (EINVAL); 3106 if (req->newptr == NULL) 3107 return (EPERM); 3108 if (req->newlen < sizeof(addrs)) 3109 return (ENOMEM); 3110 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3111 if (error) 3112 return (error); 3113 3114 switch (addrs[0].ss_family) { 3115 #ifdef INET6 3116 case AF_INET6: 3117 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3118 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3119 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3120 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3121 return (EINVAL); 3122 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3123 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3124 return (EINVAL); 3125 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3126 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3127 fin = (struct sockaddr_in *)&addrs[0]; 3128 lin = (struct sockaddr_in *)&addrs[1]; 3129 break; 3130 } 3131 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3132 if (error) 3133 return (error); 3134 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3135 if (error) 3136 return (error); 3137 break; 3138 #endif 3139 #ifdef INET 3140 case AF_INET: 3141 fin = (struct sockaddr_in *)&addrs[0]; 3142 lin = (struct sockaddr_in *)&addrs[1]; 3143 if (fin->sin_len != sizeof(struct sockaddr_in) || 3144 lin->sin_len != sizeof(struct sockaddr_in)) 3145 return (EINVAL); 3146 break; 3147 #endif 3148 default: 3149 return (EINVAL); 3150 } 3151 INP_INFO_RLOCK_ET(&V_tcbinfo, et); 3152 switch (addrs[0].ss_family) { 3153 #ifdef INET6 3154 case AF_INET6: 3155 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3156 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3157 INPLOOKUP_WLOCKPCB, NULL); 3158 break; 3159 #endif 3160 #ifdef INET 3161 case AF_INET: 3162 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3163 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3164 break; 3165 #endif 3166 } 3167 INP_INFO_RUNLOCK_ET(&V_tcbinfo, et); 3168 if (inp != NULL) { 3169 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3170 inp->inp_socket == NULL) { 3171 error = ECONNRESET; 3172 INP_WUNLOCK(inp); 3173 } else { 3174 struct socket *so; 3175 3176 so = inp->inp_socket; 3177 soref(so); 3178 error = ktls_set_tx_mode(so, 3179 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3180 INP_WUNLOCK(inp); 3181 SOCK_LOCK(so); 3182 sorele(so); 3183 } 3184 } else 3185 error = ESRCH; 3186 return (error); 3187 } 3188 3189 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3190 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3191 0, sysctl_switch_tls, "", "Switch TCP connection to SW TLS"); 3192 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3193 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3194 1, sysctl_switch_tls, "", "Switch TCP connection to ifnet TLS"); 3195 #endif 3196 3197 /* 3198 * Generate a standardized TCP log line for use throughout the 3199 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3200 * allow use in the interrupt context. 3201 * 3202 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3203 * NB: The function may return NULL if memory allocation failed. 3204 * 3205 * Due to header inclusion and ordering limitations the struct ip 3206 * and ip6_hdr pointers have to be passed as void pointers. 3207 */ 3208 char * 3209 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3210 const void *ip6hdr) 3211 { 3212 3213 /* Is logging enabled? */ 3214 if (tcp_log_in_vain == 0) 3215 return (NULL); 3216 3217 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3218 } 3219 3220 char * 3221 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3222 const void *ip6hdr) 3223 { 3224 3225 /* Is logging enabled? */ 3226 if (tcp_log_debug == 0) 3227 return (NULL); 3228 3229 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3230 } 3231 3232 static char * 3233 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3234 const void *ip6hdr) 3235 { 3236 char *s, *sp; 3237 size_t size; 3238 struct ip *ip; 3239 #ifdef INET6 3240 const struct ip6_hdr *ip6; 3241 3242 ip6 = (const struct ip6_hdr *)ip6hdr; 3243 #endif /* INET6 */ 3244 ip = (struct ip *)ip4hdr; 3245 3246 /* 3247 * The log line looks like this: 3248 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3249 */ 3250 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3251 sizeof(PRINT_TH_FLAGS) + 1 + 3252 #ifdef INET6 3253 2 * INET6_ADDRSTRLEN; 3254 #else 3255 2 * INET_ADDRSTRLEN; 3256 #endif /* INET6 */ 3257 3258 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3259 if (s == NULL) 3260 return (NULL); 3261 3262 strcat(s, "TCP: ["); 3263 sp = s + strlen(s); 3264 3265 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3266 inet_ntoa_r(inc->inc_faddr, sp); 3267 sp = s + strlen(s); 3268 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3269 sp = s + strlen(s); 3270 inet_ntoa_r(inc->inc_laddr, sp); 3271 sp = s + strlen(s); 3272 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3273 #ifdef INET6 3274 } else if (inc) { 3275 ip6_sprintf(sp, &inc->inc6_faddr); 3276 sp = s + strlen(s); 3277 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3278 sp = s + strlen(s); 3279 ip6_sprintf(sp, &inc->inc6_laddr); 3280 sp = s + strlen(s); 3281 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3282 } else if (ip6 && th) { 3283 ip6_sprintf(sp, &ip6->ip6_src); 3284 sp = s + strlen(s); 3285 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3286 sp = s + strlen(s); 3287 ip6_sprintf(sp, &ip6->ip6_dst); 3288 sp = s + strlen(s); 3289 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3290 #endif /* INET6 */ 3291 #ifdef INET 3292 } else if (ip && th) { 3293 inet_ntoa_r(ip->ip_src, sp); 3294 sp = s + strlen(s); 3295 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3296 sp = s + strlen(s); 3297 inet_ntoa_r(ip->ip_dst, sp); 3298 sp = s + strlen(s); 3299 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3300 #endif /* INET */ 3301 } else { 3302 free(s, M_TCPLOG); 3303 return (NULL); 3304 } 3305 sp = s + strlen(s); 3306 if (th) 3307 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3308 if (*(s + size - 1) != '\0') 3309 panic("%s: string too long", __func__); 3310 return (s); 3311 } 3312 3313 /* 3314 * A subroutine which makes it easy to track TCP state changes with DTrace. 3315 * This function shouldn't be called for t_state initializations that don't 3316 * correspond to actual TCP state transitions. 3317 */ 3318 void 3319 tcp_state_change(struct tcpcb *tp, int newstate) 3320 { 3321 #if defined(KDTRACE_HOOKS) 3322 int pstate = tp->t_state; 3323 #endif 3324 3325 TCPSTATES_DEC(tp->t_state); 3326 TCPSTATES_INC(newstate); 3327 tp->t_state = newstate; 3328 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3329 } 3330 3331 /* 3332 * Create an external-format (``xtcpcb'') structure using the information in 3333 * the kernel-format tcpcb structure pointed to by tp. This is done to 3334 * reduce the spew of irrelevant information over this interface, to isolate 3335 * user code from changes in the kernel structure, and potentially to provide 3336 * information-hiding if we decide that some of this information should be 3337 * hidden from users. 3338 */ 3339 void 3340 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3341 { 3342 struct tcpcb *tp = intotcpcb(inp); 3343 sbintime_t now; 3344 3345 bzero(xt, sizeof(*xt)); 3346 if (inp->inp_flags & INP_TIMEWAIT) { 3347 xt->t_state = TCPS_TIME_WAIT; 3348 } else { 3349 xt->t_state = tp->t_state; 3350 xt->t_logstate = tp->t_logstate; 3351 xt->t_flags = tp->t_flags; 3352 xt->t_sndzerowin = tp->t_sndzerowin; 3353 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3354 xt->t_rcvoopack = tp->t_rcvoopack; 3355 3356 now = getsbinuptime(); 3357 #define COPYTIMER(ttt) do { \ 3358 if (callout_active(&tp->t_timers->ttt)) \ 3359 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3360 SBT_1MS; \ 3361 else \ 3362 xt->ttt = 0; \ 3363 } while (0) 3364 COPYTIMER(tt_delack); 3365 COPYTIMER(tt_rexmt); 3366 COPYTIMER(tt_persist); 3367 COPYTIMER(tt_keep); 3368 COPYTIMER(tt_2msl); 3369 #undef COPYTIMER 3370 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3371 3372 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3373 TCP_FUNCTION_NAME_LEN_MAX); 3374 #ifdef TCP_BLACKBOX 3375 (void)tcp_log_get_id(tp, xt->xt_logid); 3376 #endif 3377 } 3378 3379 xt->xt_len = sizeof(struct xtcpcb); 3380 in_pcbtoxinpcb(inp, &xt->xt_inp); 3381 if (inp->inp_socket == NULL) 3382 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3383 } 3384