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/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #ifdef INET6 66 #include <sys/domain.h> 67 #endif 68 #include <sys/priv.h> 69 #include <sys/proc.h> 70 #include <sys/sdt.h> 71 #include <sys/socket.h> 72 #include <sys/socketvar.h> 73 #include <sys/protosw.h> 74 #include <sys/random.h> 75 76 #include <vm/uma.h> 77 78 #include <net/route.h> 79 #include <net/route/nhop.h> 80 #include <net/if.h> 81 #include <net/if_var.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_fib.h> 86 #include <netinet/in_kdtrace.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/ip_icmp.h> 92 #include <netinet/ip_var.h> 93 #ifdef INET6 94 #include <netinet/icmp6.h> 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_fib.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet6/scope6_var.h> 100 #include <netinet6/nd6.h> 101 #endif 102 103 #include <netinet/tcp.h> 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_log_buf.h> 109 #include <netinet/tcp_syncache.h> 110 #include <netinet/tcp_hpts.h> 111 #include <netinet/cc/cc.h> 112 #ifdef INET6 113 #include <netinet6/tcp6_var.h> 114 #endif 115 #include <netinet/tcpip.h> 116 #include <netinet/tcp_fastopen.h> 117 #ifdef TCPPCAP 118 #include <netinet/tcp_pcap.h> 119 #endif 120 #ifdef TCPDEBUG 121 #include <netinet/tcp_debug.h> 122 #endif 123 #ifdef INET6 124 #include <netinet6/ip6protosw.h> 125 #endif 126 #ifdef TCP_OFFLOAD 127 #include <netinet/tcp_offload.h> 128 #endif 129 130 #include <netipsec/ipsec_support.h> 131 132 #include <machine/in_cksum.h> 133 #include <crypto/siphash/siphash.h> 134 135 #include <security/mac/mac_framework.h> 136 137 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 138 #ifdef INET6 139 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 140 #endif 141 142 #ifdef NETFLIX_EXP_DETECTION 143 /* Sack attack detection thresholds and such */ 144 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 145 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 146 "Sack Attack detection thresholds"); 147 int32_t tcp_force_detection = 0; 148 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 149 CTLFLAG_RW, 150 &tcp_force_detection, 0, 151 "Do we force detection even if the INP has it off?"); 152 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 153 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 154 CTLFLAG_RW, 155 &tcp_sack_to_ack_thresh, 700, 156 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 157 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 158 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 159 CTLFLAG_RW, 160 &tcp_sack_to_move_thresh, 600, 161 "Percentage of sack moves we must see above (10.1 percent is 101)"); 162 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 163 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 164 CTLFLAG_RW, 165 &tcp_restoral_thresh, 550, 166 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 167 int32_t tcp_sad_decay_val = 800; 168 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 169 CTLFLAG_RW, 170 &tcp_sad_decay_val, 800, 171 "The decay percentage (10.1 percent equals 101 )"); 172 int32_t tcp_map_minimum = 500; 173 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 174 CTLFLAG_RW, 175 &tcp_map_minimum, 500, 176 "Number of Map enteries before we start detection"); 177 int32_t tcp_attack_on_turns_on_logging = 0; 178 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 179 CTLFLAG_RW, 180 &tcp_attack_on_turns_on_logging, 0, 181 "When we have a positive hit on attack, do we turn on logging?"); 182 int32_t tcp_sad_pacing_interval = 2000; 183 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 184 CTLFLAG_RW, 185 &tcp_sad_pacing_interval, 2000, 186 "What is the minimum pacing interval for a classified attacker?"); 187 188 int32_t tcp_sad_low_pps = 100; 189 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 190 CTLFLAG_RW, 191 &tcp_sad_low_pps, 100, 192 "What is the input pps that below which we do not decay?"); 193 #endif 194 195 struct rwlock tcp_function_lock; 196 197 static int 198 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 199 { 200 int error, new; 201 202 new = V_tcp_mssdflt; 203 error = sysctl_handle_int(oidp, &new, 0, req); 204 if (error == 0 && req->newptr) { 205 if (new < TCP_MINMSS) 206 error = EINVAL; 207 else 208 V_tcp_mssdflt = new; 209 } 210 return (error); 211 } 212 213 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 214 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 215 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 216 "Default TCP Maximum Segment Size"); 217 218 #ifdef INET6 219 static int 220 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 221 { 222 int error, new; 223 224 new = V_tcp_v6mssdflt; 225 error = sysctl_handle_int(oidp, &new, 0, req); 226 if (error == 0 && req->newptr) { 227 if (new < TCP_MINMSS) 228 error = EINVAL; 229 else 230 V_tcp_v6mssdflt = new; 231 } 232 return (error); 233 } 234 235 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 236 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 237 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 238 "Default TCP Maximum Segment Size for IPv6"); 239 #endif /* INET6 */ 240 241 /* 242 * Minimum MSS we accept and use. This prevents DoS attacks where 243 * we are forced to a ridiculous low MSS like 20 and send hundreds 244 * of packets instead of one. The effect scales with the available 245 * bandwidth and quickly saturates the CPU and network interface 246 * with packet generation and sending. Set to zero to disable MINMSS 247 * checking. This setting prevents us from sending too small packets. 248 */ 249 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 250 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 251 &VNET_NAME(tcp_minmss), 0, 252 "Minimum TCP Maximum Segment Size"); 253 254 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 255 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 256 &VNET_NAME(tcp_do_rfc1323), 0, 257 "Enable rfc1323 (high performance TCP) extensions"); 258 259 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 0; 260 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 261 &VNET_NAME(tcp_tolerate_missing_ts), 0, 262 "Tolerate missing TCP timestamps"); 263 264 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 265 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 266 &VNET_NAME(tcp_ts_offset_per_conn), 0, 267 "Initialize TCP timestamps per connection instead of per host pair"); 268 269 static int tcp_log_debug = 0; 270 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 271 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 272 273 static int tcp_tcbhashsize; 274 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 275 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 276 277 static int do_tcpdrain = 1; 278 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 279 "Enable tcp_drain routine for extra help when low on mbufs"); 280 281 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 282 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 283 284 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 285 #define V_icmp_may_rst VNET(icmp_may_rst) 286 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 287 &VNET_NAME(icmp_may_rst), 0, 288 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 289 290 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 291 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 292 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 293 &VNET_NAME(tcp_isn_reseed_interval), 0, 294 "Seconds between reseeding of ISN secret"); 295 296 static int tcp_soreceive_stream; 297 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 298 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 299 300 VNET_DEFINE(uma_zone_t, sack_hole_zone); 301 #define V_sack_hole_zone VNET(sack_hole_zone) 302 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 303 static int 304 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 305 { 306 int error; 307 uint32_t new; 308 309 new = V_tcp_map_entries_limit; 310 error = sysctl_handle_int(oidp, &new, 0, req); 311 if (error == 0 && req->newptr) { 312 /* only allow "0" and value > minimum */ 313 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 314 error = EINVAL; 315 else 316 V_tcp_map_entries_limit = new; 317 } 318 return (error); 319 } 320 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 321 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 322 &VNET_NAME(tcp_map_entries_limit), 0, 323 &sysctl_net_inet_tcp_map_limit_check, "IU", 324 "Total sendmap entries limit"); 325 326 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 327 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 328 &VNET_NAME(tcp_map_split_limit), 0, 329 "Total sendmap split entries limit"); 330 331 #ifdef TCP_HHOOK 332 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 333 #endif 334 335 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 336 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 337 #define V_ts_offset_secret VNET(ts_offset_secret) 338 339 static int tcp_default_fb_init(struct tcpcb *tp); 340 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 341 static int tcp_default_handoff_ok(struct tcpcb *tp); 342 static struct inpcb *tcp_notify(struct inpcb *, int); 343 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 344 static void tcp_mtudisc(struct inpcb *, int); 345 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 346 void *ip4hdr, const void *ip6hdr); 347 348 static struct tcp_function_block tcp_def_funcblk = { 349 .tfb_tcp_block_name = "freebsd", 350 .tfb_tcp_output = tcp_output, 351 .tfb_tcp_do_segment = tcp_do_segment, 352 .tfb_tcp_ctloutput = tcp_default_ctloutput, 353 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 354 .tfb_tcp_fb_init = tcp_default_fb_init, 355 .tfb_tcp_fb_fini = tcp_default_fb_fini, 356 }; 357 358 static int tcp_fb_cnt = 0; 359 struct tcp_funchead t_functions; 360 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 361 362 static struct tcp_function_block * 363 find_tcp_functions_locked(struct tcp_function_set *fs) 364 { 365 struct tcp_function *f; 366 struct tcp_function_block *blk=NULL; 367 368 TAILQ_FOREACH(f, &t_functions, tf_next) { 369 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 370 blk = f->tf_fb; 371 break; 372 } 373 } 374 return(blk); 375 } 376 377 static struct tcp_function_block * 378 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 379 { 380 struct tcp_function_block *rblk=NULL; 381 struct tcp_function *f; 382 383 TAILQ_FOREACH(f, &t_functions, tf_next) { 384 if (f->tf_fb == blk) { 385 rblk = blk; 386 if (s) { 387 *s = f; 388 } 389 break; 390 } 391 } 392 return (rblk); 393 } 394 395 struct tcp_function_block * 396 find_and_ref_tcp_functions(struct tcp_function_set *fs) 397 { 398 struct tcp_function_block *blk; 399 400 rw_rlock(&tcp_function_lock); 401 blk = find_tcp_functions_locked(fs); 402 if (blk) 403 refcount_acquire(&blk->tfb_refcnt); 404 rw_runlock(&tcp_function_lock); 405 return(blk); 406 } 407 408 struct tcp_function_block * 409 find_and_ref_tcp_fb(struct tcp_function_block *blk) 410 { 411 struct tcp_function_block *rblk; 412 413 rw_rlock(&tcp_function_lock); 414 rblk = find_tcp_fb_locked(blk, NULL); 415 if (rblk) 416 refcount_acquire(&rblk->tfb_refcnt); 417 rw_runlock(&tcp_function_lock); 418 return(rblk); 419 } 420 421 static struct tcp_function_block * 422 find_and_ref_tcp_default_fb(void) 423 { 424 struct tcp_function_block *rblk; 425 426 rw_rlock(&tcp_function_lock); 427 rblk = tcp_func_set_ptr; 428 refcount_acquire(&rblk->tfb_refcnt); 429 rw_runlock(&tcp_function_lock); 430 return (rblk); 431 } 432 433 void 434 tcp_switch_back_to_default(struct tcpcb *tp) 435 { 436 struct tcp_function_block *tfb; 437 438 KASSERT(tp->t_fb != &tcp_def_funcblk, 439 ("%s: called by the built-in default stack", __func__)); 440 441 /* 442 * Release the old stack. This function will either find a new one 443 * or panic. 444 */ 445 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 446 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 447 refcount_release(&tp->t_fb->tfb_refcnt); 448 449 /* 450 * Now, we'll find a new function block to use. 451 * Start by trying the current user-selected 452 * default, unless this stack is the user-selected 453 * default. 454 */ 455 tfb = find_and_ref_tcp_default_fb(); 456 if (tfb == tp->t_fb) { 457 refcount_release(&tfb->tfb_refcnt); 458 tfb = NULL; 459 } 460 /* Does the stack accept this connection? */ 461 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 462 (*tfb->tfb_tcp_handoff_ok)(tp)) { 463 refcount_release(&tfb->tfb_refcnt); 464 tfb = NULL; 465 } 466 /* Try to use that stack. */ 467 if (tfb != NULL) { 468 /* Initialize the new stack. If it succeeds, we are done. */ 469 tp->t_fb = tfb; 470 if (tp->t_fb->tfb_tcp_fb_init == NULL || 471 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 472 return; 473 474 /* 475 * Initialization failed. Release the reference count on 476 * the stack. 477 */ 478 refcount_release(&tfb->tfb_refcnt); 479 } 480 481 /* 482 * If that wasn't feasible, use the built-in default 483 * stack which is not allowed to reject anyone. 484 */ 485 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 486 if (tfb == NULL) { 487 /* there always should be a default */ 488 panic("Can't refer to tcp_def_funcblk"); 489 } 490 if (tfb->tfb_tcp_handoff_ok != NULL) { 491 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 492 /* The default stack cannot say no */ 493 panic("Default stack rejects a new session?"); 494 } 495 } 496 tp->t_fb = tfb; 497 if (tp->t_fb->tfb_tcp_fb_init != NULL && 498 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 499 /* The default stack cannot fail */ 500 panic("Default stack initialization failed"); 501 } 502 } 503 504 static int 505 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 506 { 507 int error=ENOENT; 508 struct tcp_function_set fs; 509 struct tcp_function_block *blk; 510 511 memset(&fs, 0, sizeof(fs)); 512 rw_rlock(&tcp_function_lock); 513 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 514 if (blk) { 515 /* Found him */ 516 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 517 fs.pcbcnt = blk->tfb_refcnt; 518 } 519 rw_runlock(&tcp_function_lock); 520 error = sysctl_handle_string(oidp, fs.function_set_name, 521 sizeof(fs.function_set_name), req); 522 523 /* Check for error or no change */ 524 if (error != 0 || req->newptr == NULL) 525 return(error); 526 527 rw_wlock(&tcp_function_lock); 528 blk = find_tcp_functions_locked(&fs); 529 if ((blk == NULL) || 530 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 531 error = ENOENT; 532 goto done; 533 } 534 tcp_func_set_ptr = blk; 535 done: 536 rw_wunlock(&tcp_function_lock); 537 return (error); 538 } 539 540 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 541 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 542 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 543 "Set/get the default TCP functions"); 544 545 static int 546 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 547 { 548 int error, cnt, linesz; 549 struct tcp_function *f; 550 char *buffer, *cp; 551 size_t bufsz, outsz; 552 bool alias; 553 554 cnt = 0; 555 rw_rlock(&tcp_function_lock); 556 TAILQ_FOREACH(f, &t_functions, tf_next) { 557 cnt++; 558 } 559 rw_runlock(&tcp_function_lock); 560 561 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 562 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 563 564 error = 0; 565 cp = buffer; 566 567 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 568 "Alias", "PCB count"); 569 cp += linesz; 570 bufsz -= linesz; 571 outsz = linesz; 572 573 rw_rlock(&tcp_function_lock); 574 TAILQ_FOREACH(f, &t_functions, tf_next) { 575 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 576 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 577 f->tf_fb->tfb_tcp_block_name, 578 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 579 alias ? f->tf_name : "-", 580 f->tf_fb->tfb_refcnt); 581 if (linesz >= bufsz) { 582 error = EOVERFLOW; 583 break; 584 } 585 cp += linesz; 586 bufsz -= linesz; 587 outsz += linesz; 588 } 589 rw_runlock(&tcp_function_lock); 590 if (error == 0) 591 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 592 free(buffer, M_TEMP); 593 return (error); 594 } 595 596 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 597 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 598 NULL, 0, sysctl_net_inet_list_available, "A", 599 "list available TCP Function sets"); 600 601 /* 602 * Exports one (struct tcp_function_info) for each alias/name. 603 */ 604 static int 605 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 606 { 607 int cnt, error; 608 struct tcp_function *f; 609 struct tcp_function_info tfi; 610 611 /* 612 * We don't allow writes. 613 */ 614 if (req->newptr != NULL) 615 return (EINVAL); 616 617 /* 618 * Wire the old buffer so we can directly copy the functions to 619 * user space without dropping the lock. 620 */ 621 if (req->oldptr != NULL) { 622 error = sysctl_wire_old_buffer(req, 0); 623 if (error) 624 return (error); 625 } 626 627 /* 628 * Walk the list and copy out matching entries. If INVARIANTS 629 * is compiled in, also walk the list to verify the length of 630 * the list matches what we have recorded. 631 */ 632 rw_rlock(&tcp_function_lock); 633 634 cnt = 0; 635 #ifndef INVARIANTS 636 if (req->oldptr == NULL) { 637 cnt = tcp_fb_cnt; 638 goto skip_loop; 639 } 640 #endif 641 TAILQ_FOREACH(f, &t_functions, tf_next) { 642 #ifdef INVARIANTS 643 cnt++; 644 #endif 645 if (req->oldptr != NULL) { 646 bzero(&tfi, sizeof(tfi)); 647 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 648 tfi.tfi_id = f->tf_fb->tfb_id; 649 (void)strlcpy(tfi.tfi_alias, f->tf_name, 650 sizeof(tfi.tfi_alias)); 651 (void)strlcpy(tfi.tfi_name, 652 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 653 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 654 /* 655 * Don't stop on error, as that is the 656 * mechanism we use to accumulate length 657 * information if the buffer was too short. 658 */ 659 } 660 } 661 KASSERT(cnt == tcp_fb_cnt, 662 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 663 #ifndef INVARIANTS 664 skip_loop: 665 #endif 666 rw_runlock(&tcp_function_lock); 667 if (req->oldptr == NULL) 668 error = SYSCTL_OUT(req, NULL, 669 (cnt + 1) * sizeof(struct tcp_function_info)); 670 671 return (error); 672 } 673 674 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 675 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 676 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 677 "List TCP function block name-to-ID mappings"); 678 679 /* 680 * tfb_tcp_handoff_ok() function for the default stack. 681 * Note that we'll basically try to take all comers. 682 */ 683 static int 684 tcp_default_handoff_ok(struct tcpcb *tp) 685 { 686 687 return (0); 688 } 689 690 /* 691 * tfb_tcp_fb_init() function for the default stack. 692 * 693 * This handles making sure we have appropriate timers set if you are 694 * transitioning a socket that has some amount of setup done. 695 * 696 * The init() fuction from the default can *never* return non-zero i.e. 697 * it is required to always succeed since it is the stack of last resort! 698 */ 699 static int 700 tcp_default_fb_init(struct tcpcb *tp) 701 { 702 703 struct socket *so; 704 705 INP_WLOCK_ASSERT(tp->t_inpcb); 706 707 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 708 ("%s: connection %p in unexpected state %d", __func__, tp, 709 tp->t_state)); 710 711 /* 712 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 713 * know what to do for unexpected states (which includes TIME_WAIT). 714 */ 715 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 716 return (0); 717 718 /* 719 * Make sure some kind of transmission timer is set if there is 720 * outstanding data. 721 */ 722 so = tp->t_inpcb->inp_socket; 723 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 724 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 725 tcp_timer_active(tp, TT_PERSIST))) { 726 /* 727 * If the session has established and it looks like it should 728 * be in the persist state, set the persist timer. Otherwise, 729 * set the retransmit timer. 730 */ 731 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 732 (int32_t)(tp->snd_nxt - tp->snd_una) < 733 (int32_t)sbavail(&so->so_snd)) 734 tcp_setpersist(tp); 735 else 736 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 737 } 738 739 /* All non-embryonic sessions get a keepalive timer. */ 740 if (!tcp_timer_active(tp, TT_KEEP)) 741 tcp_timer_activate(tp, TT_KEEP, 742 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 743 TP_KEEPINIT(tp)); 744 745 /* 746 * Make sure critical variables are initialized 747 * if transitioning while in Recovery. 748 */ 749 if IN_FASTRECOVERY(tp->t_flags) { 750 if (tp->sackhint.recover_fs == 0) 751 tp->sackhint.recover_fs = max(1, 752 tp->snd_nxt - tp->snd_una); 753 } 754 755 return (0); 756 } 757 758 /* 759 * tfb_tcp_fb_fini() function for the default stack. 760 * 761 * This changes state as necessary (or prudent) to prepare for another stack 762 * to assume responsibility for the connection. 763 */ 764 static void 765 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 766 { 767 768 INP_WLOCK_ASSERT(tp->t_inpcb); 769 return; 770 } 771 772 /* 773 * Target size of TCP PCB hash tables. Must be a power of two. 774 * 775 * Note that this can be overridden by the kernel environment 776 * variable net.inet.tcp.tcbhashsize 777 */ 778 #ifndef TCBHASHSIZE 779 #define TCBHASHSIZE 0 780 #endif 781 782 /* 783 * XXX 784 * Callouts should be moved into struct tcp directly. They are currently 785 * separate because the tcpcb structure is exported to userland for sysctl 786 * parsing purposes, which do not know about callouts. 787 */ 788 struct tcpcb_mem { 789 struct tcpcb tcb; 790 struct tcp_timer tt; 791 struct cc_var ccv; 792 #ifdef TCP_HHOOK 793 struct osd osd; 794 #endif 795 }; 796 797 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 798 #define V_tcpcb_zone VNET(tcpcb_zone) 799 800 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 801 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 802 803 static struct mtx isn_mtx; 804 805 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 806 #define ISN_LOCK() mtx_lock(&isn_mtx) 807 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 808 809 /* 810 * TCP initialization. 811 */ 812 static void 813 tcp_zone_change(void *tag) 814 { 815 816 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 817 uma_zone_set_max(V_tcpcb_zone, maxsockets); 818 tcp_tw_zone_change(); 819 } 820 821 static int 822 tcp_inpcb_init(void *mem, int size, int flags) 823 { 824 struct inpcb *inp = mem; 825 826 INP_LOCK_INIT(inp, "inp", "tcpinp"); 827 return (0); 828 } 829 830 /* 831 * Take a value and get the next power of 2 that doesn't overflow. 832 * Used to size the tcp_inpcb hash buckets. 833 */ 834 static int 835 maketcp_hashsize(int size) 836 { 837 int hashsize; 838 839 /* 840 * auto tune. 841 * get the next power of 2 higher than maxsockets. 842 */ 843 hashsize = 1 << fls(size); 844 /* catch overflow, and just go one power of 2 smaller */ 845 if (hashsize < size) { 846 hashsize = 1 << (fls(size) - 1); 847 } 848 return (hashsize); 849 } 850 851 static volatile int next_tcp_stack_id = 1; 852 853 /* 854 * Register a TCP function block with the name provided in the names 855 * array. (Note that this function does NOT automatically register 856 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 857 * explicitly include blk->tfb_tcp_block_name in the list of names if 858 * you wish to register the stack with that name.) 859 * 860 * Either all name registrations will succeed or all will fail. If 861 * a name registration fails, the function will update the num_names 862 * argument to point to the array index of the name that encountered 863 * the failure. 864 * 865 * Returns 0 on success, or an error code on failure. 866 */ 867 int 868 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 869 const char *names[], int *num_names) 870 { 871 struct tcp_function *n; 872 struct tcp_function_set fs; 873 int error, i; 874 875 KASSERT(names != NULL && *num_names > 0, 876 ("%s: Called with 0-length name list", __func__)); 877 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 878 KASSERT(rw_initialized(&tcp_function_lock), 879 ("%s: called too early", __func__)); 880 881 if ((blk->tfb_tcp_output == NULL) || 882 (blk->tfb_tcp_do_segment == NULL) || 883 (blk->tfb_tcp_ctloutput == NULL) || 884 (strlen(blk->tfb_tcp_block_name) == 0)) { 885 /* 886 * These functions are required and you 887 * need a name. 888 */ 889 *num_names = 0; 890 return (EINVAL); 891 } 892 if (blk->tfb_tcp_timer_stop_all || 893 blk->tfb_tcp_timer_activate || 894 blk->tfb_tcp_timer_active || 895 blk->tfb_tcp_timer_stop) { 896 /* 897 * If you define one timer function you 898 * must have them all. 899 */ 900 if ((blk->tfb_tcp_timer_stop_all == NULL) || 901 (blk->tfb_tcp_timer_activate == NULL) || 902 (blk->tfb_tcp_timer_active == NULL) || 903 (blk->tfb_tcp_timer_stop == NULL)) { 904 *num_names = 0; 905 return (EINVAL); 906 } 907 } 908 909 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 910 *num_names = 0; 911 return (EINVAL); 912 } 913 914 refcount_init(&blk->tfb_refcnt, 0); 915 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 916 for (i = 0; i < *num_names; i++) { 917 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 918 if (n == NULL) { 919 error = ENOMEM; 920 goto cleanup; 921 } 922 n->tf_fb = blk; 923 924 (void)strlcpy(fs.function_set_name, names[i], 925 sizeof(fs.function_set_name)); 926 rw_wlock(&tcp_function_lock); 927 if (find_tcp_functions_locked(&fs) != NULL) { 928 /* Duplicate name space not allowed */ 929 rw_wunlock(&tcp_function_lock); 930 free(n, M_TCPFUNCTIONS); 931 error = EALREADY; 932 goto cleanup; 933 } 934 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 935 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 936 tcp_fb_cnt++; 937 rw_wunlock(&tcp_function_lock); 938 } 939 return(0); 940 941 cleanup: 942 /* 943 * Deregister the names we just added. Because registration failed 944 * for names[i], we don't need to deregister that name. 945 */ 946 *num_names = i; 947 rw_wlock(&tcp_function_lock); 948 while (--i >= 0) { 949 TAILQ_FOREACH(n, &t_functions, tf_next) { 950 if (!strncmp(n->tf_name, names[i], 951 TCP_FUNCTION_NAME_LEN_MAX)) { 952 TAILQ_REMOVE(&t_functions, n, tf_next); 953 tcp_fb_cnt--; 954 n->tf_fb = NULL; 955 free(n, M_TCPFUNCTIONS); 956 break; 957 } 958 } 959 } 960 rw_wunlock(&tcp_function_lock); 961 return (error); 962 } 963 964 /* 965 * Register a TCP function block using the name provided in the name 966 * argument. 967 * 968 * Returns 0 on success, or an error code on failure. 969 */ 970 int 971 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 972 int wait) 973 { 974 const char *name_list[1]; 975 int num_names, rv; 976 977 num_names = 1; 978 if (name != NULL) 979 name_list[0] = name; 980 else 981 name_list[0] = blk->tfb_tcp_block_name; 982 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 983 return (rv); 984 } 985 986 /* 987 * Register a TCP function block using the name defined in 988 * blk->tfb_tcp_block_name. 989 * 990 * Returns 0 on success, or an error code on failure. 991 */ 992 int 993 register_tcp_functions(struct tcp_function_block *blk, int wait) 994 { 995 996 return (register_tcp_functions_as_name(blk, NULL, wait)); 997 } 998 999 /* 1000 * Deregister all names associated with a function block. This 1001 * functionally removes the function block from use within the system. 1002 * 1003 * When called with a true quiesce argument, mark the function block 1004 * as being removed so no more stacks will use it and determine 1005 * whether the removal would succeed. 1006 * 1007 * When called with a false quiesce argument, actually attempt the 1008 * removal. 1009 * 1010 * When called with a force argument, attempt to switch all TCBs to 1011 * use the default stack instead of returning EBUSY. 1012 * 1013 * Returns 0 on success (or if the removal would succeed, or an error 1014 * code on failure. 1015 */ 1016 int 1017 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1018 bool force) 1019 { 1020 struct tcp_function *f; 1021 1022 if (blk == &tcp_def_funcblk) { 1023 /* You can't un-register the default */ 1024 return (EPERM); 1025 } 1026 rw_wlock(&tcp_function_lock); 1027 if (blk == tcp_func_set_ptr) { 1028 /* You can't free the current default */ 1029 rw_wunlock(&tcp_function_lock); 1030 return (EBUSY); 1031 } 1032 /* Mark the block so no more stacks can use it. */ 1033 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1034 /* 1035 * If TCBs are still attached to the stack, attempt to switch them 1036 * to the default stack. 1037 */ 1038 if (force && blk->tfb_refcnt) { 1039 struct inpcb *inp; 1040 struct tcpcb *tp; 1041 VNET_ITERATOR_DECL(vnet_iter); 1042 1043 rw_wunlock(&tcp_function_lock); 1044 1045 VNET_LIST_RLOCK(); 1046 VNET_FOREACH(vnet_iter) { 1047 CURVNET_SET(vnet_iter); 1048 INP_INFO_WLOCK(&V_tcbinfo); 1049 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1050 INP_WLOCK(inp); 1051 if (inp->inp_flags & INP_TIMEWAIT) { 1052 INP_WUNLOCK(inp); 1053 continue; 1054 } 1055 tp = intotcpcb(inp); 1056 if (tp == NULL || tp->t_fb != blk) { 1057 INP_WUNLOCK(inp); 1058 continue; 1059 } 1060 tcp_switch_back_to_default(tp); 1061 INP_WUNLOCK(inp); 1062 } 1063 INP_INFO_WUNLOCK(&V_tcbinfo); 1064 CURVNET_RESTORE(); 1065 } 1066 VNET_LIST_RUNLOCK(); 1067 1068 rw_wlock(&tcp_function_lock); 1069 } 1070 if (blk->tfb_refcnt) { 1071 /* TCBs still attached. */ 1072 rw_wunlock(&tcp_function_lock); 1073 return (EBUSY); 1074 } 1075 if (quiesce) { 1076 /* Skip removal. */ 1077 rw_wunlock(&tcp_function_lock); 1078 return (0); 1079 } 1080 /* Remove any function names that map to this function block. */ 1081 while (find_tcp_fb_locked(blk, &f) != NULL) { 1082 TAILQ_REMOVE(&t_functions, f, tf_next); 1083 tcp_fb_cnt--; 1084 f->tf_fb = NULL; 1085 free(f, M_TCPFUNCTIONS); 1086 } 1087 rw_wunlock(&tcp_function_lock); 1088 return (0); 1089 } 1090 1091 void 1092 tcp_init(void) 1093 { 1094 const char *tcbhash_tuneable; 1095 int hashsize; 1096 1097 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1098 1099 #ifdef TCP_HHOOK 1100 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1101 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1102 printf("%s: WARNING: unable to register helper hook\n", __func__); 1103 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1104 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1105 printf("%s: WARNING: unable to register helper hook\n", __func__); 1106 #endif 1107 #ifdef STATS 1108 if (tcp_stats_init()) 1109 printf("%s: WARNING: unable to initialise TCP stats\n", 1110 __func__); 1111 #endif 1112 hashsize = TCBHASHSIZE; 1113 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1114 if (hashsize == 0) { 1115 /* 1116 * Auto tune the hash size based on maxsockets. 1117 * A perfect hash would have a 1:1 mapping 1118 * (hashsize = maxsockets) however it's been 1119 * suggested that O(2) average is better. 1120 */ 1121 hashsize = maketcp_hashsize(maxsockets / 4); 1122 /* 1123 * Our historical default is 512, 1124 * do not autotune lower than this. 1125 */ 1126 if (hashsize < 512) 1127 hashsize = 512; 1128 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1129 printf("%s: %s auto tuned to %d\n", __func__, 1130 tcbhash_tuneable, hashsize); 1131 } 1132 /* 1133 * We require a hashsize to be a power of two. 1134 * Previously if it was not a power of two we would just reset it 1135 * back to 512, which could be a nasty surprise if you did not notice 1136 * the error message. 1137 * Instead what we do is clip it to the closest power of two lower 1138 * than the specified hash value. 1139 */ 1140 if (!powerof2(hashsize)) { 1141 int oldhashsize = hashsize; 1142 1143 hashsize = maketcp_hashsize(hashsize); 1144 /* prevent absurdly low value */ 1145 if (hashsize < 16) 1146 hashsize = 16; 1147 printf("%s: WARNING: TCB hash size not a power of 2, " 1148 "clipped from %d to %d.\n", __func__, oldhashsize, 1149 hashsize); 1150 } 1151 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1152 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1153 1154 /* 1155 * These have to be type stable for the benefit of the timers. 1156 */ 1157 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1158 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1159 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1160 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1161 1162 tcp_tw_init(); 1163 syncache_init(); 1164 tcp_hc_init(); 1165 1166 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1167 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1168 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1169 1170 tcp_fastopen_init(); 1171 1172 /* Skip initialization of globals for non-default instances. */ 1173 if (!IS_DEFAULT_VNET(curvnet)) 1174 return; 1175 1176 tcp_reass_global_init(); 1177 1178 /* XXX virtualize those bellow? */ 1179 tcp_delacktime = TCPTV_DELACK; 1180 tcp_keepinit = TCPTV_KEEP_INIT; 1181 tcp_keepidle = TCPTV_KEEP_IDLE; 1182 tcp_keepintvl = TCPTV_KEEPINTVL; 1183 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1184 tcp_msl = TCPTV_MSL; 1185 tcp_rexmit_initial = TCPTV_RTOBASE; 1186 if (tcp_rexmit_initial < 1) 1187 tcp_rexmit_initial = 1; 1188 tcp_rexmit_min = TCPTV_MIN; 1189 if (tcp_rexmit_min < 1) 1190 tcp_rexmit_min = 1; 1191 tcp_persmin = TCPTV_PERSMIN; 1192 tcp_persmax = TCPTV_PERSMAX; 1193 tcp_rexmit_slop = TCPTV_CPU_VAR; 1194 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1195 tcp_tcbhashsize = hashsize; 1196 1197 /* Setup the tcp function block list */ 1198 TAILQ_INIT(&t_functions); 1199 rw_init(&tcp_function_lock, "tcp_func_lock"); 1200 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1201 #ifdef TCP_BLACKBOX 1202 /* Initialize the TCP logging data. */ 1203 tcp_log_init(); 1204 #endif 1205 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1206 1207 if (tcp_soreceive_stream) { 1208 #ifdef INET 1209 tcp_usrreqs.pru_soreceive = soreceive_stream; 1210 #endif 1211 #ifdef INET6 1212 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1213 #endif /* INET6 */ 1214 } 1215 1216 #ifdef INET6 1217 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1218 #else /* INET6 */ 1219 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1220 #endif /* INET6 */ 1221 if (max_protohdr < TCP_MINPROTOHDR) 1222 max_protohdr = TCP_MINPROTOHDR; 1223 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1224 panic("tcp_init"); 1225 #undef TCP_MINPROTOHDR 1226 1227 ISN_LOCK_INIT(); 1228 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1229 SHUTDOWN_PRI_DEFAULT); 1230 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1231 EVENTHANDLER_PRI_ANY); 1232 1233 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1234 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1235 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1236 tcp_inp_lro_single_push = counter_u64_alloc(M_WAITOK); 1237 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1238 tcp_inp_lro_sack_wake = counter_u64_alloc(M_WAITOK); 1239 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1240 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1241 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1242 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1243 tcp_csum_hardware = counter_u64_alloc(M_WAITOK); 1244 tcp_csum_hardware_w_ph = counter_u64_alloc(M_WAITOK); 1245 tcp_csum_software = counter_u64_alloc(M_WAITOK); 1246 #ifdef TCPPCAP 1247 tcp_pcap_init(); 1248 #endif 1249 } 1250 1251 #ifdef VIMAGE 1252 static void 1253 tcp_destroy(void *unused __unused) 1254 { 1255 int n; 1256 #ifdef TCP_HHOOK 1257 int error; 1258 #endif 1259 1260 /* 1261 * All our processes are gone, all our sockets should be cleaned 1262 * up, which means, we should be past the tcp_discardcb() calls. 1263 * Sleep to let all tcpcb timers really disappear and cleanup. 1264 */ 1265 for (;;) { 1266 INP_LIST_RLOCK(&V_tcbinfo); 1267 n = V_tcbinfo.ipi_count; 1268 INP_LIST_RUNLOCK(&V_tcbinfo); 1269 if (n == 0) 1270 break; 1271 pause("tcpdes", hz / 10); 1272 } 1273 tcp_hc_destroy(); 1274 syncache_destroy(); 1275 tcp_tw_destroy(); 1276 in_pcbinfo_destroy(&V_tcbinfo); 1277 /* tcp_discardcb() clears the sack_holes up. */ 1278 uma_zdestroy(V_sack_hole_zone); 1279 uma_zdestroy(V_tcpcb_zone); 1280 1281 /* 1282 * Cannot free the zone until all tcpcbs are released as we attach 1283 * the allocations to them. 1284 */ 1285 tcp_fastopen_destroy(); 1286 1287 #ifdef TCP_HHOOK 1288 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1289 if (error != 0) { 1290 printf("%s: WARNING: unable to deregister helper hook " 1291 "type=%d, id=%d: error %d returned\n", __func__, 1292 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1293 } 1294 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1295 if (error != 0) { 1296 printf("%s: WARNING: unable to deregister helper hook " 1297 "type=%d, id=%d: error %d returned\n", __func__, 1298 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1299 } 1300 #endif 1301 } 1302 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1303 #endif 1304 1305 void 1306 tcp_fini(void *xtp) 1307 { 1308 1309 } 1310 1311 /* 1312 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1313 * tcp_template used to store this data in mbufs, but we now recopy it out 1314 * of the tcpcb each time to conserve mbufs. 1315 */ 1316 void 1317 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1318 { 1319 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1320 1321 INP_WLOCK_ASSERT(inp); 1322 1323 #ifdef INET6 1324 if ((inp->inp_vflag & INP_IPV6) != 0) { 1325 struct ip6_hdr *ip6; 1326 1327 ip6 = (struct ip6_hdr *)ip_ptr; 1328 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1329 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1330 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1331 (IPV6_VERSION & IPV6_VERSION_MASK); 1332 ip6->ip6_nxt = IPPROTO_TCP; 1333 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1334 ip6->ip6_src = inp->in6p_laddr; 1335 ip6->ip6_dst = inp->in6p_faddr; 1336 } 1337 #endif /* INET6 */ 1338 #if defined(INET6) && defined(INET) 1339 else 1340 #endif 1341 #ifdef INET 1342 { 1343 struct ip *ip; 1344 1345 ip = (struct ip *)ip_ptr; 1346 ip->ip_v = IPVERSION; 1347 ip->ip_hl = 5; 1348 ip->ip_tos = inp->inp_ip_tos; 1349 ip->ip_len = 0; 1350 ip->ip_id = 0; 1351 ip->ip_off = 0; 1352 ip->ip_ttl = inp->inp_ip_ttl; 1353 ip->ip_sum = 0; 1354 ip->ip_p = IPPROTO_TCP; 1355 ip->ip_src = inp->inp_laddr; 1356 ip->ip_dst = inp->inp_faddr; 1357 } 1358 #endif /* INET */ 1359 th->th_sport = inp->inp_lport; 1360 th->th_dport = inp->inp_fport; 1361 th->th_seq = 0; 1362 th->th_ack = 0; 1363 th->th_x2 = 0; 1364 th->th_off = 5; 1365 th->th_flags = 0; 1366 th->th_win = 0; 1367 th->th_urp = 0; 1368 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1369 } 1370 1371 /* 1372 * Create template to be used to send tcp packets on a connection. 1373 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1374 * use for this function is in keepalives, which use tcp_respond. 1375 */ 1376 struct tcptemp * 1377 tcpip_maketemplate(struct inpcb *inp) 1378 { 1379 struct tcptemp *t; 1380 1381 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1382 if (t == NULL) 1383 return (NULL); 1384 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1385 return (t); 1386 } 1387 1388 /* 1389 * Send a single message to the TCP at address specified by 1390 * the given TCP/IP header. If m == NULL, then we make a copy 1391 * of the tcpiphdr at th and send directly to the addressed host. 1392 * This is used to force keep alive messages out using the TCP 1393 * template for a connection. If flags are given then we send 1394 * a message back to the TCP which originated the segment th, 1395 * and discard the mbuf containing it and any other attached mbufs. 1396 * 1397 * In any case the ack and sequence number of the transmitted 1398 * segment are as specified by the parameters. 1399 * 1400 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1401 */ 1402 void 1403 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1404 tcp_seq ack, tcp_seq seq, int flags) 1405 { 1406 struct tcpopt to; 1407 struct inpcb *inp; 1408 struct ip *ip; 1409 struct mbuf *optm; 1410 struct tcphdr *nth; 1411 u_char *optp; 1412 #ifdef INET6 1413 struct ip6_hdr *ip6; 1414 int isipv6; 1415 #endif /* INET6 */ 1416 int optlen, tlen, win; 1417 bool incl_opts; 1418 1419 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1420 NET_EPOCH_ASSERT(); 1421 1422 #ifdef INET6 1423 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1424 ip6 = ipgen; 1425 #endif /* INET6 */ 1426 ip = ipgen; 1427 1428 if (tp != NULL) { 1429 inp = tp->t_inpcb; 1430 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1431 INP_WLOCK_ASSERT(inp); 1432 } else 1433 inp = NULL; 1434 1435 incl_opts = false; 1436 win = 0; 1437 if (tp != NULL) { 1438 if (!(flags & TH_RST)) { 1439 win = sbspace(&inp->inp_socket->so_rcv); 1440 if (win > TCP_MAXWIN << tp->rcv_scale) 1441 win = TCP_MAXWIN << tp->rcv_scale; 1442 } 1443 if ((tp->t_flags & TF_NOOPT) == 0) 1444 incl_opts = true; 1445 } 1446 if (m == NULL) { 1447 m = m_gethdr(M_NOWAIT, MT_DATA); 1448 if (m == NULL) 1449 return; 1450 m->m_data += max_linkhdr; 1451 #ifdef INET6 1452 if (isipv6) { 1453 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1454 sizeof(struct ip6_hdr)); 1455 ip6 = mtod(m, struct ip6_hdr *); 1456 nth = (struct tcphdr *)(ip6 + 1); 1457 } else 1458 #endif /* INET6 */ 1459 { 1460 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1461 ip = mtod(m, struct ip *); 1462 nth = (struct tcphdr *)(ip + 1); 1463 } 1464 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1465 flags = TH_ACK; 1466 } else if (!M_WRITABLE(m)) { 1467 struct mbuf *n; 1468 1469 /* Can't reuse 'm', allocate a new mbuf. */ 1470 n = m_gethdr(M_NOWAIT, MT_DATA); 1471 if (n == NULL) { 1472 m_freem(m); 1473 return; 1474 } 1475 1476 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1477 m_freem(m); 1478 m_freem(n); 1479 return; 1480 } 1481 1482 n->m_data += max_linkhdr; 1483 /* m_len is set later */ 1484 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1485 #ifdef INET6 1486 if (isipv6) { 1487 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1488 sizeof(struct ip6_hdr)); 1489 ip6 = mtod(n, struct ip6_hdr *); 1490 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1491 nth = (struct tcphdr *)(ip6 + 1); 1492 } else 1493 #endif /* INET6 */ 1494 { 1495 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1496 ip = mtod(n, struct ip *); 1497 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1498 nth = (struct tcphdr *)(ip + 1); 1499 } 1500 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1501 xchg(nth->th_dport, nth->th_sport, uint16_t); 1502 th = nth; 1503 m_freem(m); 1504 m = n; 1505 } else { 1506 /* 1507 * reuse the mbuf. 1508 * XXX MRT We inherit the FIB, which is lucky. 1509 */ 1510 m_freem(m->m_next); 1511 m->m_next = NULL; 1512 m->m_data = (caddr_t)ipgen; 1513 /* m_len is set later */ 1514 #ifdef INET6 1515 if (isipv6) { 1516 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1517 nth = (struct tcphdr *)(ip6 + 1); 1518 } else 1519 #endif /* INET6 */ 1520 { 1521 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1522 nth = (struct tcphdr *)(ip + 1); 1523 } 1524 if (th != nth) { 1525 /* 1526 * this is usually a case when an extension header 1527 * exists between the IPv6 header and the 1528 * TCP header. 1529 */ 1530 nth->th_sport = th->th_sport; 1531 nth->th_dport = th->th_dport; 1532 } 1533 xchg(nth->th_dport, nth->th_sport, uint16_t); 1534 #undef xchg 1535 } 1536 tlen = 0; 1537 #ifdef INET6 1538 if (isipv6) 1539 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1540 #endif 1541 #if defined(INET) && defined(INET6) 1542 else 1543 #endif 1544 #ifdef INET 1545 tlen = sizeof (struct tcpiphdr); 1546 #endif 1547 #ifdef INVARIANTS 1548 m->m_len = 0; 1549 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1550 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1551 m, tlen, (long)M_TRAILINGSPACE(m))); 1552 #endif 1553 m->m_len = tlen; 1554 to.to_flags = 0; 1555 if (incl_opts) { 1556 /* Make sure we have room. */ 1557 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1558 m->m_next = m_get(M_NOWAIT, MT_DATA); 1559 if (m->m_next) { 1560 optp = mtod(m->m_next, u_char *); 1561 optm = m->m_next; 1562 } else 1563 incl_opts = false; 1564 } else { 1565 optp = (u_char *) (nth + 1); 1566 optm = m; 1567 } 1568 } 1569 if (incl_opts) { 1570 /* Timestamps. */ 1571 if (tp->t_flags & TF_RCVD_TSTMP) { 1572 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1573 to.to_tsecr = tp->ts_recent; 1574 to.to_flags |= TOF_TS; 1575 } 1576 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1577 /* TCP-MD5 (RFC2385). */ 1578 if (tp->t_flags & TF_SIGNATURE) 1579 to.to_flags |= TOF_SIGNATURE; 1580 #endif 1581 /* Add the options. */ 1582 tlen += optlen = tcp_addoptions(&to, optp); 1583 1584 /* Update m_len in the correct mbuf. */ 1585 optm->m_len += optlen; 1586 } else 1587 optlen = 0; 1588 #ifdef INET6 1589 if (isipv6) { 1590 ip6->ip6_flow = 0; 1591 ip6->ip6_vfc = IPV6_VERSION; 1592 ip6->ip6_nxt = IPPROTO_TCP; 1593 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1594 } 1595 #endif 1596 #if defined(INET) && defined(INET6) 1597 else 1598 #endif 1599 #ifdef INET 1600 { 1601 ip->ip_len = htons(tlen); 1602 ip->ip_ttl = V_ip_defttl; 1603 if (V_path_mtu_discovery) 1604 ip->ip_off |= htons(IP_DF); 1605 } 1606 #endif 1607 m->m_pkthdr.len = tlen; 1608 m->m_pkthdr.rcvif = NULL; 1609 #ifdef MAC 1610 if (inp != NULL) { 1611 /* 1612 * Packet is associated with a socket, so allow the 1613 * label of the response to reflect the socket label. 1614 */ 1615 INP_WLOCK_ASSERT(inp); 1616 mac_inpcb_create_mbuf(inp, m); 1617 } else { 1618 /* 1619 * Packet is not associated with a socket, so possibly 1620 * update the label in place. 1621 */ 1622 mac_netinet_tcp_reply(m); 1623 } 1624 #endif 1625 nth->th_seq = htonl(seq); 1626 nth->th_ack = htonl(ack); 1627 nth->th_x2 = 0; 1628 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1629 nth->th_flags = flags; 1630 if (tp != NULL) 1631 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1632 else 1633 nth->th_win = htons((u_short)win); 1634 nth->th_urp = 0; 1635 1636 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1637 if (to.to_flags & TOF_SIGNATURE) { 1638 if (!TCPMD5_ENABLED() || 1639 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1640 m_freem(m); 1641 return; 1642 } 1643 } 1644 #endif 1645 1646 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1647 #ifdef INET6 1648 if (isipv6) { 1649 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1650 nth->th_sum = in6_cksum_pseudo(ip6, 1651 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1652 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1653 NULL, NULL); 1654 } 1655 #endif /* INET6 */ 1656 #if defined(INET6) && defined(INET) 1657 else 1658 #endif 1659 #ifdef INET 1660 { 1661 m->m_pkthdr.csum_flags = CSUM_TCP; 1662 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1663 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1664 } 1665 #endif /* INET */ 1666 #ifdef TCPDEBUG 1667 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1668 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1669 #endif 1670 TCP_PROBE3(debug__output, tp, th, m); 1671 if (flags & TH_RST) 1672 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1673 1674 #ifdef INET6 1675 if (isipv6) { 1676 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1677 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1678 } 1679 #endif /* INET6 */ 1680 #if defined(INET) && defined(INET6) 1681 else 1682 #endif 1683 #ifdef INET 1684 { 1685 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1686 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1687 } 1688 #endif 1689 } 1690 1691 /* 1692 * Create a new TCP control block, making an 1693 * empty reassembly queue and hooking it to the argument 1694 * protocol control block. The `inp' parameter must have 1695 * come from the zone allocator set up in tcp_init(). 1696 */ 1697 struct tcpcb * 1698 tcp_newtcpcb(struct inpcb *inp) 1699 { 1700 struct tcpcb_mem *tm; 1701 struct tcpcb *tp; 1702 #ifdef INET6 1703 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1704 #endif /* INET6 */ 1705 1706 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1707 if (tm == NULL) 1708 return (NULL); 1709 tp = &tm->tcb; 1710 1711 /* Initialise cc_var struct for this tcpcb. */ 1712 tp->ccv = &tm->ccv; 1713 tp->ccv->type = IPPROTO_TCP; 1714 tp->ccv->ccvc.tcp = tp; 1715 rw_rlock(&tcp_function_lock); 1716 tp->t_fb = tcp_func_set_ptr; 1717 refcount_acquire(&tp->t_fb->tfb_refcnt); 1718 rw_runlock(&tcp_function_lock); 1719 /* 1720 * Use the current system default CC algorithm. 1721 */ 1722 CC_LIST_RLOCK(); 1723 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1724 CC_ALGO(tp) = CC_DEFAULT(); 1725 CC_LIST_RUNLOCK(); 1726 /* 1727 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1728 * is called. 1729 */ 1730 in_pcbref(inp); /* Reference for tcpcb */ 1731 tp->t_inpcb = inp; 1732 1733 if (CC_ALGO(tp)->cb_init != NULL) 1734 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1735 if (tp->t_fb->tfb_tcp_fb_fini) 1736 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1737 in_pcbrele_wlocked(inp); 1738 refcount_release(&tp->t_fb->tfb_refcnt); 1739 uma_zfree(V_tcpcb_zone, tm); 1740 return (NULL); 1741 } 1742 1743 #ifdef TCP_HHOOK 1744 tp->osd = &tm->osd; 1745 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1746 if (tp->t_fb->tfb_tcp_fb_fini) 1747 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1748 in_pcbrele_wlocked(inp); 1749 refcount_release(&tp->t_fb->tfb_refcnt); 1750 uma_zfree(V_tcpcb_zone, tm); 1751 return (NULL); 1752 } 1753 #endif 1754 1755 #ifdef VIMAGE 1756 tp->t_vnet = inp->inp_vnet; 1757 #endif 1758 tp->t_timers = &tm->tt; 1759 TAILQ_INIT(&tp->t_segq); 1760 tp->t_maxseg = 1761 #ifdef INET6 1762 isipv6 ? V_tcp_v6mssdflt : 1763 #endif /* INET6 */ 1764 V_tcp_mssdflt; 1765 1766 /* Set up our timeouts. */ 1767 callout_init(&tp->t_timers->tt_rexmt, 1); 1768 callout_init(&tp->t_timers->tt_persist, 1); 1769 callout_init(&tp->t_timers->tt_keep, 1); 1770 callout_init(&tp->t_timers->tt_2msl, 1); 1771 callout_init(&tp->t_timers->tt_delack, 1); 1772 1773 if (V_tcp_do_rfc1323) 1774 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1775 if (V_tcp_do_sack) 1776 tp->t_flags |= TF_SACK_PERMIT; 1777 TAILQ_INIT(&tp->snd_holes); 1778 1779 /* 1780 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1781 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1782 * reasonable initial retransmit time. 1783 */ 1784 tp->t_srtt = TCPTV_SRTTBASE; 1785 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1786 tp->t_rttmin = tcp_rexmit_min; 1787 tp->t_rxtcur = tcp_rexmit_initial; 1788 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1789 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1790 tp->t_rcvtime = ticks; 1791 /* 1792 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1793 * because the socket may be bound to an IPv6 wildcard address, 1794 * which may match an IPv4-mapped IPv6 address. 1795 */ 1796 inp->inp_ip_ttl = V_ip_defttl; 1797 inp->inp_ppcb = tp; 1798 #ifdef TCPPCAP 1799 /* 1800 * Init the TCP PCAP queues. 1801 */ 1802 tcp_pcap_tcpcb_init(tp); 1803 #endif 1804 #ifdef TCP_BLACKBOX 1805 /* Initialize the per-TCPCB log data. */ 1806 tcp_log_tcpcbinit(tp); 1807 #endif 1808 tp->t_pacing_rate = -1; 1809 if (tp->t_fb->tfb_tcp_fb_init) { 1810 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 1811 refcount_release(&tp->t_fb->tfb_refcnt); 1812 in_pcbrele_wlocked(inp); 1813 uma_zfree(V_tcpcb_zone, tm); 1814 return (NULL); 1815 } 1816 } 1817 #ifdef STATS 1818 if (V_tcp_perconn_stats_enable == 1) 1819 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 1820 #endif 1821 return (tp); /* XXX */ 1822 } 1823 1824 /* 1825 * Switch the congestion control algorithm back to NewReno for any active 1826 * control blocks using an algorithm which is about to go away. 1827 * This ensures the CC framework can allow the unload to proceed without leaving 1828 * any dangling pointers which would trigger a panic. 1829 * Returning non-zero would inform the CC framework that something went wrong 1830 * and it would be unsafe to allow the unload to proceed. However, there is no 1831 * way for this to occur with this implementation so we always return zero. 1832 */ 1833 int 1834 tcp_ccalgounload(struct cc_algo *unload_algo) 1835 { 1836 struct cc_algo *tmpalgo; 1837 struct inpcb *inp; 1838 struct tcpcb *tp; 1839 VNET_ITERATOR_DECL(vnet_iter); 1840 1841 /* 1842 * Check all active control blocks across all network stacks and change 1843 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1844 * requires cleanup code to be run, call it. 1845 */ 1846 VNET_LIST_RLOCK(); 1847 VNET_FOREACH(vnet_iter) { 1848 CURVNET_SET(vnet_iter); 1849 INP_INFO_WLOCK(&V_tcbinfo); 1850 /* 1851 * New connections already part way through being initialised 1852 * with the CC algo we're removing will not race with this code 1853 * because the INP_INFO_WLOCK is held during initialisation. We 1854 * therefore don't enter the loop below until the connection 1855 * list has stabilised. 1856 */ 1857 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1858 INP_WLOCK(inp); 1859 /* Important to skip tcptw structs. */ 1860 if (!(inp->inp_flags & INP_TIMEWAIT) && 1861 (tp = intotcpcb(inp)) != NULL) { 1862 /* 1863 * By holding INP_WLOCK here, we are assured 1864 * that the connection is not currently 1865 * executing inside the CC module's functions 1866 * i.e. it is safe to make the switch back to 1867 * NewReno. 1868 */ 1869 if (CC_ALGO(tp) == unload_algo) { 1870 tmpalgo = CC_ALGO(tp); 1871 if (tmpalgo->cb_destroy != NULL) 1872 tmpalgo->cb_destroy(tp->ccv); 1873 CC_DATA(tp) = NULL; 1874 /* 1875 * NewReno may allocate memory on 1876 * demand for certain stateful 1877 * configuration as needed, but is 1878 * coded to never fail on memory 1879 * allocation failure so it is a safe 1880 * fallback. 1881 */ 1882 CC_ALGO(tp) = &newreno_cc_algo; 1883 } 1884 } 1885 INP_WUNLOCK(inp); 1886 } 1887 INP_INFO_WUNLOCK(&V_tcbinfo); 1888 CURVNET_RESTORE(); 1889 } 1890 VNET_LIST_RUNLOCK(); 1891 1892 return (0); 1893 } 1894 1895 /* 1896 * Drop a TCP connection, reporting 1897 * the specified error. If connection is synchronized, 1898 * then send a RST to peer. 1899 */ 1900 struct tcpcb * 1901 tcp_drop(struct tcpcb *tp, int errno) 1902 { 1903 struct socket *so = tp->t_inpcb->inp_socket; 1904 1905 NET_EPOCH_ASSERT(); 1906 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1907 INP_WLOCK_ASSERT(tp->t_inpcb); 1908 1909 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1910 tcp_state_change(tp, TCPS_CLOSED); 1911 (void) tp->t_fb->tfb_tcp_output(tp); 1912 TCPSTAT_INC(tcps_drops); 1913 } else 1914 TCPSTAT_INC(tcps_conndrops); 1915 if (errno == ETIMEDOUT && tp->t_softerror) 1916 errno = tp->t_softerror; 1917 so->so_error = errno; 1918 return (tcp_close(tp)); 1919 } 1920 1921 void 1922 tcp_discardcb(struct tcpcb *tp) 1923 { 1924 struct inpcb *inp = tp->t_inpcb; 1925 struct socket *so = inp->inp_socket; 1926 #ifdef INET6 1927 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1928 #endif /* INET6 */ 1929 int released __unused; 1930 1931 INP_WLOCK_ASSERT(inp); 1932 1933 /* 1934 * Make sure that all of our timers are stopped before we delete the 1935 * PCB. 1936 * 1937 * If stopping a timer fails, we schedule a discard function in same 1938 * callout, and the last discard function called will take care of 1939 * deleting the tcpcb. 1940 */ 1941 tp->t_timers->tt_draincnt = 0; 1942 tcp_timer_stop(tp, TT_REXMT); 1943 tcp_timer_stop(tp, TT_PERSIST); 1944 tcp_timer_stop(tp, TT_KEEP); 1945 tcp_timer_stop(tp, TT_2MSL); 1946 tcp_timer_stop(tp, TT_DELACK); 1947 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1948 /* 1949 * Call the stop-all function of the methods, 1950 * this function should call the tcp_timer_stop() 1951 * method with each of the function specific timeouts. 1952 * That stop will be called via the tfb_tcp_timer_stop() 1953 * which should use the async drain function of the 1954 * callout system (see tcp_var.h). 1955 */ 1956 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1957 } 1958 1959 /* 1960 * If we got enough samples through the srtt filter, 1961 * save the rtt and rttvar in the routing entry. 1962 * 'Enough' is arbitrarily defined as 4 rtt samples. 1963 * 4 samples is enough for the srtt filter to converge 1964 * to within enough % of the correct value; fewer samples 1965 * and we could save a bogus rtt. The danger is not high 1966 * as tcp quickly recovers from everything. 1967 * XXX: Works very well but needs some more statistics! 1968 */ 1969 if (tp->t_rttupdated >= 4) { 1970 struct hc_metrics_lite metrics; 1971 uint32_t ssthresh; 1972 1973 bzero(&metrics, sizeof(metrics)); 1974 /* 1975 * Update the ssthresh always when the conditions below 1976 * are satisfied. This gives us better new start value 1977 * for the congestion avoidance for new connections. 1978 * ssthresh is only set if packet loss occurred on a session. 1979 * 1980 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1981 * being torn down. Ideally this code would not use 'so'. 1982 */ 1983 ssthresh = tp->snd_ssthresh; 1984 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1985 /* 1986 * convert the limit from user data bytes to 1987 * packets then to packet data bytes. 1988 */ 1989 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1990 if (ssthresh < 2) 1991 ssthresh = 2; 1992 ssthresh *= (tp->t_maxseg + 1993 #ifdef INET6 1994 (isipv6 ? sizeof (struct ip6_hdr) + 1995 sizeof (struct tcphdr) : 1996 #endif 1997 sizeof (struct tcpiphdr) 1998 #ifdef INET6 1999 ) 2000 #endif 2001 ); 2002 } else 2003 ssthresh = 0; 2004 metrics.rmx_ssthresh = ssthresh; 2005 2006 metrics.rmx_rtt = tp->t_srtt; 2007 metrics.rmx_rttvar = tp->t_rttvar; 2008 metrics.rmx_cwnd = tp->snd_cwnd; 2009 metrics.rmx_sendpipe = 0; 2010 metrics.rmx_recvpipe = 0; 2011 2012 tcp_hc_update(&inp->inp_inc, &metrics); 2013 } 2014 2015 /* free the reassembly queue, if any */ 2016 tcp_reass_flush(tp); 2017 2018 #ifdef TCP_OFFLOAD 2019 /* Disconnect offload device, if any. */ 2020 if (tp->t_flags & TF_TOE) 2021 tcp_offload_detach(tp); 2022 #endif 2023 2024 tcp_free_sackholes(tp); 2025 2026 #ifdef TCPPCAP 2027 /* Free the TCP PCAP queues. */ 2028 tcp_pcap_drain(&(tp->t_inpkts)); 2029 tcp_pcap_drain(&(tp->t_outpkts)); 2030 #endif 2031 2032 /* Allow the CC algorithm to clean up after itself. */ 2033 if (CC_ALGO(tp)->cb_destroy != NULL) 2034 CC_ALGO(tp)->cb_destroy(tp->ccv); 2035 CC_DATA(tp) = NULL; 2036 2037 #ifdef TCP_HHOOK 2038 khelp_destroy_osd(tp->osd); 2039 #endif 2040 #ifdef STATS 2041 stats_blob_destroy(tp->t_stats); 2042 #endif 2043 2044 CC_ALGO(tp) = NULL; 2045 inp->inp_ppcb = NULL; 2046 if (tp->t_timers->tt_draincnt == 0) { 2047 /* We own the last reference on tcpcb, let's free it. */ 2048 #ifdef TCP_BLACKBOX 2049 tcp_log_tcpcbfini(tp); 2050 #endif 2051 TCPSTATES_DEC(tp->t_state); 2052 if (tp->t_fb->tfb_tcp_fb_fini) 2053 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2054 refcount_release(&tp->t_fb->tfb_refcnt); 2055 tp->t_inpcb = NULL; 2056 uma_zfree(V_tcpcb_zone, tp); 2057 released = in_pcbrele_wlocked(inp); 2058 KASSERT(!released, ("%s: inp %p should not have been released " 2059 "here", __func__, inp)); 2060 } 2061 } 2062 2063 void 2064 tcp_timer_discard(void *ptp) 2065 { 2066 struct inpcb *inp; 2067 struct tcpcb *tp; 2068 struct epoch_tracker et; 2069 2070 tp = (struct tcpcb *)ptp; 2071 CURVNET_SET(tp->t_vnet); 2072 NET_EPOCH_ENTER(et); 2073 inp = tp->t_inpcb; 2074 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 2075 __func__, tp)); 2076 INP_WLOCK(inp); 2077 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 2078 ("%s: tcpcb has to be stopped here", __func__)); 2079 tp->t_timers->tt_draincnt--; 2080 if (tp->t_timers->tt_draincnt == 0) { 2081 /* We own the last reference on this tcpcb, let's free it. */ 2082 #ifdef TCP_BLACKBOX 2083 tcp_log_tcpcbfini(tp); 2084 #endif 2085 TCPSTATES_DEC(tp->t_state); 2086 if (tp->t_fb->tfb_tcp_fb_fini) 2087 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2088 refcount_release(&tp->t_fb->tfb_refcnt); 2089 tp->t_inpcb = NULL; 2090 uma_zfree(V_tcpcb_zone, tp); 2091 if (in_pcbrele_wlocked(inp)) { 2092 NET_EPOCH_EXIT(et); 2093 CURVNET_RESTORE(); 2094 return; 2095 } 2096 } 2097 INP_WUNLOCK(inp); 2098 NET_EPOCH_EXIT(et); 2099 CURVNET_RESTORE(); 2100 } 2101 2102 /* 2103 * Attempt to close a TCP control block, marking it as dropped, and freeing 2104 * the socket if we hold the only reference. 2105 */ 2106 struct tcpcb * 2107 tcp_close(struct tcpcb *tp) 2108 { 2109 struct inpcb *inp = tp->t_inpcb; 2110 struct socket *so; 2111 2112 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2113 INP_WLOCK_ASSERT(inp); 2114 2115 #ifdef TCP_OFFLOAD 2116 if (tp->t_state == TCPS_LISTEN) 2117 tcp_offload_listen_stop(tp); 2118 #endif 2119 /* 2120 * This releases the TFO pending counter resource for TFO listen 2121 * sockets as well as passively-created TFO sockets that transition 2122 * from SYN_RECEIVED to CLOSED. 2123 */ 2124 if (tp->t_tfo_pending) { 2125 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2126 tp->t_tfo_pending = NULL; 2127 } 2128 in_pcbdrop(inp); 2129 TCPSTAT_INC(tcps_closed); 2130 if (tp->t_state != TCPS_CLOSED) 2131 tcp_state_change(tp, TCPS_CLOSED); 2132 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2133 so = inp->inp_socket; 2134 soisdisconnected(so); 2135 if (inp->inp_flags & INP_SOCKREF) { 2136 KASSERT(so->so_state & SS_PROTOREF, 2137 ("tcp_close: !SS_PROTOREF")); 2138 inp->inp_flags &= ~INP_SOCKREF; 2139 INP_WUNLOCK(inp); 2140 SOCK_LOCK(so); 2141 so->so_state &= ~SS_PROTOREF; 2142 sofree(so); 2143 return (NULL); 2144 } 2145 return (tp); 2146 } 2147 2148 void 2149 tcp_drain(void) 2150 { 2151 VNET_ITERATOR_DECL(vnet_iter); 2152 2153 if (!do_tcpdrain) 2154 return; 2155 2156 VNET_LIST_RLOCK_NOSLEEP(); 2157 VNET_FOREACH(vnet_iter) { 2158 CURVNET_SET(vnet_iter); 2159 struct inpcb *inpb; 2160 struct tcpcb *tcpb; 2161 2162 /* 2163 * Walk the tcpbs, if existing, and flush the reassembly queue, 2164 * if there is one... 2165 * XXX: The "Net/3" implementation doesn't imply that the TCP 2166 * reassembly queue should be flushed, but in a situation 2167 * where we're really low on mbufs, this is potentially 2168 * useful. 2169 */ 2170 INP_INFO_WLOCK(&V_tcbinfo); 2171 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2172 INP_WLOCK(inpb); 2173 if (inpb->inp_flags & INP_TIMEWAIT) { 2174 INP_WUNLOCK(inpb); 2175 continue; 2176 } 2177 if ((tcpb = intotcpcb(inpb)) != NULL) { 2178 tcp_reass_flush(tcpb); 2179 tcp_clean_sackreport(tcpb); 2180 #ifdef TCP_BLACKBOX 2181 tcp_log_drain(tcpb); 2182 #endif 2183 #ifdef TCPPCAP 2184 if (tcp_pcap_aggressive_free) { 2185 /* Free the TCP PCAP queues. */ 2186 tcp_pcap_drain(&(tcpb->t_inpkts)); 2187 tcp_pcap_drain(&(tcpb->t_outpkts)); 2188 } 2189 #endif 2190 } 2191 INP_WUNLOCK(inpb); 2192 } 2193 INP_INFO_WUNLOCK(&V_tcbinfo); 2194 CURVNET_RESTORE(); 2195 } 2196 VNET_LIST_RUNLOCK_NOSLEEP(); 2197 } 2198 2199 /* 2200 * Notify a tcp user of an asynchronous error; 2201 * store error as soft error, but wake up user 2202 * (for now, won't do anything until can select for soft error). 2203 * 2204 * Do not wake up user since there currently is no mechanism for 2205 * reporting soft errors (yet - a kqueue filter may be added). 2206 */ 2207 static struct inpcb * 2208 tcp_notify(struct inpcb *inp, int error) 2209 { 2210 struct tcpcb *tp; 2211 2212 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2213 INP_WLOCK_ASSERT(inp); 2214 2215 if ((inp->inp_flags & INP_TIMEWAIT) || 2216 (inp->inp_flags & INP_DROPPED)) 2217 return (inp); 2218 2219 tp = intotcpcb(inp); 2220 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2221 2222 /* 2223 * Ignore some errors if we are hooked up. 2224 * If connection hasn't completed, has retransmitted several times, 2225 * and receives a second error, give up now. This is better 2226 * than waiting a long time to establish a connection that 2227 * can never complete. 2228 */ 2229 if (tp->t_state == TCPS_ESTABLISHED && 2230 (error == EHOSTUNREACH || error == ENETUNREACH || 2231 error == EHOSTDOWN)) { 2232 if (inp->inp_route.ro_nh) { 2233 NH_FREE(inp->inp_route.ro_nh); 2234 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2235 } 2236 return (inp); 2237 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2238 tp->t_softerror) { 2239 tp = tcp_drop(tp, error); 2240 if (tp != NULL) 2241 return (inp); 2242 else 2243 return (NULL); 2244 } else { 2245 tp->t_softerror = error; 2246 return (inp); 2247 } 2248 #if 0 2249 wakeup( &so->so_timeo); 2250 sorwakeup(so); 2251 sowwakeup(so); 2252 #endif 2253 } 2254 2255 static int 2256 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2257 { 2258 struct epoch_tracker et; 2259 struct inpcb *inp; 2260 struct xinpgen xig; 2261 int error; 2262 2263 if (req->newptr != NULL) 2264 return (EPERM); 2265 2266 if (req->oldptr == NULL) { 2267 int n; 2268 2269 n = V_tcbinfo.ipi_count + 2270 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2271 n += imax(n / 8, 10); 2272 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2273 return (0); 2274 } 2275 2276 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2277 return (error); 2278 2279 bzero(&xig, sizeof(xig)); 2280 xig.xig_len = sizeof xig; 2281 xig.xig_count = V_tcbinfo.ipi_count + 2282 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2283 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2284 xig.xig_sogen = so_gencnt; 2285 error = SYSCTL_OUT(req, &xig, sizeof xig); 2286 if (error) 2287 return (error); 2288 2289 error = syncache_pcblist(req); 2290 if (error) 2291 return (error); 2292 2293 NET_EPOCH_ENTER(et); 2294 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2295 inp != NULL; 2296 inp = CK_LIST_NEXT(inp, inp_list)) { 2297 INP_RLOCK(inp); 2298 if (inp->inp_gencnt <= xig.xig_gen) { 2299 int crerr; 2300 2301 /* 2302 * XXX: This use of cr_cansee(), introduced with 2303 * TCP state changes, is not quite right, but for 2304 * now, better than nothing. 2305 */ 2306 if (inp->inp_flags & INP_TIMEWAIT) { 2307 if (intotw(inp) != NULL) 2308 crerr = cr_cansee(req->td->td_ucred, 2309 intotw(inp)->tw_cred); 2310 else 2311 crerr = EINVAL; /* Skip this inp. */ 2312 } else 2313 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2314 if (crerr == 0) { 2315 struct xtcpcb xt; 2316 2317 tcp_inptoxtp(inp, &xt); 2318 INP_RUNLOCK(inp); 2319 error = SYSCTL_OUT(req, &xt, sizeof xt); 2320 if (error) 2321 break; 2322 else 2323 continue; 2324 } 2325 } 2326 INP_RUNLOCK(inp); 2327 } 2328 NET_EPOCH_EXIT(et); 2329 2330 if (!error) { 2331 /* 2332 * Give the user an updated idea of our state. 2333 * If the generation differs from what we told 2334 * her before, she knows that something happened 2335 * while we were processing this request, and it 2336 * might be necessary to retry. 2337 */ 2338 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2339 xig.xig_sogen = so_gencnt; 2340 xig.xig_count = V_tcbinfo.ipi_count + 2341 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2342 error = SYSCTL_OUT(req, &xig, sizeof xig); 2343 } 2344 2345 return (error); 2346 } 2347 2348 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2349 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2350 NULL, 0, tcp_pcblist, "S,xtcpcb", 2351 "List of active TCP connections"); 2352 2353 #ifdef INET 2354 static int 2355 tcp_getcred(SYSCTL_HANDLER_ARGS) 2356 { 2357 struct xucred xuc; 2358 struct sockaddr_in addrs[2]; 2359 struct epoch_tracker et; 2360 struct inpcb *inp; 2361 int error; 2362 2363 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2364 if (error) 2365 return (error); 2366 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2367 if (error) 2368 return (error); 2369 NET_EPOCH_ENTER(et); 2370 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2371 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2372 NET_EPOCH_EXIT(et); 2373 if (inp != NULL) { 2374 if (inp->inp_socket == NULL) 2375 error = ENOENT; 2376 if (error == 0) 2377 error = cr_canseeinpcb(req->td->td_ucred, inp); 2378 if (error == 0) 2379 cru2x(inp->inp_cred, &xuc); 2380 INP_RUNLOCK(inp); 2381 } else 2382 error = ENOENT; 2383 if (error == 0) 2384 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2385 return (error); 2386 } 2387 2388 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2389 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2390 0, 0, tcp_getcred, "S,xucred", 2391 "Get the xucred of a TCP connection"); 2392 #endif /* INET */ 2393 2394 #ifdef INET6 2395 static int 2396 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2397 { 2398 struct epoch_tracker et; 2399 struct xucred xuc; 2400 struct sockaddr_in6 addrs[2]; 2401 struct inpcb *inp; 2402 int error; 2403 #ifdef INET 2404 int mapped = 0; 2405 #endif 2406 2407 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2408 if (error) 2409 return (error); 2410 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2411 if (error) 2412 return (error); 2413 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2414 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2415 return (error); 2416 } 2417 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2418 #ifdef INET 2419 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2420 mapped = 1; 2421 else 2422 #endif 2423 return (EINVAL); 2424 } 2425 2426 NET_EPOCH_ENTER(et); 2427 #ifdef INET 2428 if (mapped == 1) 2429 inp = in_pcblookup(&V_tcbinfo, 2430 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2431 addrs[1].sin6_port, 2432 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2433 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2434 else 2435 #endif 2436 inp = in6_pcblookup(&V_tcbinfo, 2437 &addrs[1].sin6_addr, addrs[1].sin6_port, 2438 &addrs[0].sin6_addr, addrs[0].sin6_port, 2439 INPLOOKUP_RLOCKPCB, NULL); 2440 NET_EPOCH_EXIT(et); 2441 if (inp != NULL) { 2442 if (inp->inp_socket == NULL) 2443 error = ENOENT; 2444 if (error == 0) 2445 error = cr_canseeinpcb(req->td->td_ucred, inp); 2446 if (error == 0) 2447 cru2x(inp->inp_cred, &xuc); 2448 INP_RUNLOCK(inp); 2449 } else 2450 error = ENOENT; 2451 if (error == 0) 2452 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2453 return (error); 2454 } 2455 2456 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2457 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2458 0, 0, tcp6_getcred, "S,xucred", 2459 "Get the xucred of a TCP6 connection"); 2460 #endif /* INET6 */ 2461 2462 #ifdef INET 2463 void 2464 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2465 { 2466 struct ip *ip = vip; 2467 struct tcphdr *th; 2468 struct in_addr faddr; 2469 struct inpcb *inp; 2470 struct tcpcb *tp; 2471 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2472 struct icmp *icp; 2473 struct in_conninfo inc; 2474 tcp_seq icmp_tcp_seq; 2475 int mtu; 2476 2477 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2478 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2479 return; 2480 2481 if (cmd == PRC_MSGSIZE) 2482 notify = tcp_mtudisc_notify; 2483 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2484 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2485 cmd == PRC_TIMXCEED_INTRANS) && ip) 2486 notify = tcp_drop_syn_sent; 2487 2488 /* 2489 * Hostdead is ugly because it goes linearly through all PCBs. 2490 * XXX: We never get this from ICMP, otherwise it makes an 2491 * excellent DoS attack on machines with many connections. 2492 */ 2493 else if (cmd == PRC_HOSTDEAD) 2494 ip = NULL; 2495 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2496 return; 2497 2498 if (ip == NULL) { 2499 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2500 return; 2501 } 2502 2503 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2504 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2505 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2506 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2507 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2508 /* signal EHOSTDOWN, as it flushes the cached route */ 2509 inp = (*notify)(inp, EHOSTDOWN); 2510 goto out; 2511 } 2512 icmp_tcp_seq = th->th_seq; 2513 if (inp != NULL) { 2514 if (!(inp->inp_flags & INP_TIMEWAIT) && 2515 !(inp->inp_flags & INP_DROPPED) && 2516 !(inp->inp_socket == NULL)) { 2517 tp = intotcpcb(inp); 2518 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2519 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2520 if (cmd == PRC_MSGSIZE) { 2521 /* 2522 * MTU discovery: 2523 * If we got a needfrag set the MTU 2524 * in the route to the suggested new 2525 * value (if given) and then notify. 2526 */ 2527 mtu = ntohs(icp->icmp_nextmtu); 2528 /* 2529 * If no alternative MTU was 2530 * proposed, try the next smaller 2531 * one. 2532 */ 2533 if (!mtu) 2534 mtu = ip_next_mtu( 2535 ntohs(ip->ip_len), 1); 2536 if (mtu < V_tcp_minmss + 2537 sizeof(struct tcpiphdr)) 2538 mtu = V_tcp_minmss + 2539 sizeof(struct tcpiphdr); 2540 /* 2541 * Only process the offered MTU if it 2542 * is smaller than the current one. 2543 */ 2544 if (mtu < tp->t_maxseg + 2545 sizeof(struct tcpiphdr)) { 2546 bzero(&inc, sizeof(inc)); 2547 inc.inc_faddr = faddr; 2548 inc.inc_fibnum = 2549 inp->inp_inc.inc_fibnum; 2550 tcp_hc_updatemtu(&inc, mtu); 2551 tcp_mtudisc(inp, mtu); 2552 } 2553 } else 2554 inp = (*notify)(inp, 2555 inetctlerrmap[cmd]); 2556 } 2557 } 2558 } else { 2559 bzero(&inc, sizeof(inc)); 2560 inc.inc_fport = th->th_dport; 2561 inc.inc_lport = th->th_sport; 2562 inc.inc_faddr = faddr; 2563 inc.inc_laddr = ip->ip_src; 2564 syncache_unreach(&inc, icmp_tcp_seq); 2565 } 2566 out: 2567 if (inp != NULL) 2568 INP_WUNLOCK(inp); 2569 } 2570 #endif /* INET */ 2571 2572 #ifdef INET6 2573 void 2574 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2575 { 2576 struct in6_addr *dst; 2577 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2578 struct ip6_hdr *ip6; 2579 struct mbuf *m; 2580 struct inpcb *inp; 2581 struct tcpcb *tp; 2582 struct icmp6_hdr *icmp6; 2583 struct ip6ctlparam *ip6cp = NULL; 2584 const struct sockaddr_in6 *sa6_src = NULL; 2585 struct in_conninfo inc; 2586 struct tcp_ports { 2587 uint16_t th_sport; 2588 uint16_t th_dport; 2589 } t_ports; 2590 tcp_seq icmp_tcp_seq; 2591 unsigned int mtu; 2592 unsigned int off; 2593 2594 if (sa->sa_family != AF_INET6 || 2595 sa->sa_len != sizeof(struct sockaddr_in6)) 2596 return; 2597 2598 /* if the parameter is from icmp6, decode it. */ 2599 if (d != NULL) { 2600 ip6cp = (struct ip6ctlparam *)d; 2601 icmp6 = ip6cp->ip6c_icmp6; 2602 m = ip6cp->ip6c_m; 2603 ip6 = ip6cp->ip6c_ip6; 2604 off = ip6cp->ip6c_off; 2605 sa6_src = ip6cp->ip6c_src; 2606 dst = ip6cp->ip6c_finaldst; 2607 } else { 2608 m = NULL; 2609 ip6 = NULL; 2610 off = 0; /* fool gcc */ 2611 sa6_src = &sa6_any; 2612 dst = NULL; 2613 } 2614 2615 if (cmd == PRC_MSGSIZE) 2616 notify = tcp_mtudisc_notify; 2617 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2618 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2619 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2620 notify = tcp_drop_syn_sent; 2621 2622 /* 2623 * Hostdead is ugly because it goes linearly through all PCBs. 2624 * XXX: We never get this from ICMP, otherwise it makes an 2625 * excellent DoS attack on machines with many connections. 2626 */ 2627 else if (cmd == PRC_HOSTDEAD) 2628 ip6 = NULL; 2629 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2630 return; 2631 2632 if (ip6 == NULL) { 2633 in6_pcbnotify(&V_tcbinfo, sa, 0, 2634 (const struct sockaddr *)sa6_src, 2635 0, cmd, NULL, notify); 2636 return; 2637 } 2638 2639 /* Check if we can safely get the ports from the tcp hdr */ 2640 if (m == NULL || 2641 (m->m_pkthdr.len < 2642 (int32_t) (off + sizeof(struct tcp_ports)))) { 2643 return; 2644 } 2645 bzero(&t_ports, sizeof(struct tcp_ports)); 2646 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2647 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2648 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2649 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2650 /* signal EHOSTDOWN, as it flushes the cached route */ 2651 inp = (*notify)(inp, EHOSTDOWN); 2652 goto out; 2653 } 2654 off += sizeof(struct tcp_ports); 2655 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2656 goto out; 2657 } 2658 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2659 if (inp != NULL) { 2660 if (!(inp->inp_flags & INP_TIMEWAIT) && 2661 !(inp->inp_flags & INP_DROPPED) && 2662 !(inp->inp_socket == NULL)) { 2663 tp = intotcpcb(inp); 2664 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2665 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2666 if (cmd == PRC_MSGSIZE) { 2667 /* 2668 * MTU discovery: 2669 * If we got a needfrag set the MTU 2670 * in the route to the suggested new 2671 * value (if given) and then notify. 2672 */ 2673 mtu = ntohl(icmp6->icmp6_mtu); 2674 /* 2675 * If no alternative MTU was 2676 * proposed, or the proposed 2677 * MTU was too small, set to 2678 * the min. 2679 */ 2680 if (mtu < IPV6_MMTU) 2681 mtu = IPV6_MMTU - 8; 2682 bzero(&inc, sizeof(inc)); 2683 inc.inc_fibnum = M_GETFIB(m); 2684 inc.inc_flags |= INC_ISIPV6; 2685 inc.inc6_faddr = *dst; 2686 if (in6_setscope(&inc.inc6_faddr, 2687 m->m_pkthdr.rcvif, NULL)) 2688 goto out; 2689 /* 2690 * Only process the offered MTU if it 2691 * is smaller than the current one. 2692 */ 2693 if (mtu < tp->t_maxseg + 2694 sizeof (struct tcphdr) + 2695 sizeof (struct ip6_hdr)) { 2696 tcp_hc_updatemtu(&inc, mtu); 2697 tcp_mtudisc(inp, mtu); 2698 ICMP6STAT_INC(icp6s_pmtuchg); 2699 } 2700 } else 2701 inp = (*notify)(inp, 2702 inet6ctlerrmap[cmd]); 2703 } 2704 } 2705 } else { 2706 bzero(&inc, sizeof(inc)); 2707 inc.inc_fibnum = M_GETFIB(m); 2708 inc.inc_flags |= INC_ISIPV6; 2709 inc.inc_fport = t_ports.th_dport; 2710 inc.inc_lport = t_ports.th_sport; 2711 inc.inc6_faddr = *dst; 2712 inc.inc6_laddr = ip6->ip6_src; 2713 syncache_unreach(&inc, icmp_tcp_seq); 2714 } 2715 out: 2716 if (inp != NULL) 2717 INP_WUNLOCK(inp); 2718 } 2719 #endif /* INET6 */ 2720 2721 static uint32_t 2722 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2723 { 2724 SIPHASH_CTX ctx; 2725 uint32_t hash[2]; 2726 2727 KASSERT(len >= SIPHASH_KEY_LENGTH, 2728 ("%s: keylen %u too short ", __func__, len)); 2729 SipHash24_Init(&ctx); 2730 SipHash_SetKey(&ctx, (uint8_t *)key); 2731 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2732 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2733 switch (inc->inc_flags & INC_ISIPV6) { 2734 #ifdef INET 2735 case 0: 2736 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2737 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2738 break; 2739 #endif 2740 #ifdef INET6 2741 case INC_ISIPV6: 2742 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2743 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2744 break; 2745 #endif 2746 } 2747 SipHash_Final((uint8_t *)hash, &ctx); 2748 2749 return (hash[0] ^ hash[1]); 2750 } 2751 2752 uint32_t 2753 tcp_new_ts_offset(struct in_conninfo *inc) 2754 { 2755 struct in_conninfo inc_store, *local_inc; 2756 2757 if (!V_tcp_ts_offset_per_conn) { 2758 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 2759 inc_store.inc_lport = 0; 2760 inc_store.inc_fport = 0; 2761 local_inc = &inc_store; 2762 } else { 2763 local_inc = inc; 2764 } 2765 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 2766 sizeof(V_ts_offset_secret))); 2767 } 2768 2769 /* 2770 * Following is where TCP initial sequence number generation occurs. 2771 * 2772 * There are two places where we must use initial sequence numbers: 2773 * 1. In SYN-ACK packets. 2774 * 2. In SYN packets. 2775 * 2776 * All ISNs for SYN-ACK packets are generated by the syncache. See 2777 * tcp_syncache.c for details. 2778 * 2779 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2780 * depends on this property. In addition, these ISNs should be 2781 * unguessable so as to prevent connection hijacking. To satisfy 2782 * the requirements of this situation, the algorithm outlined in 2783 * RFC 1948 is used, with only small modifications. 2784 * 2785 * Implementation details: 2786 * 2787 * Time is based off the system timer, and is corrected so that it 2788 * increases by one megabyte per second. This allows for proper 2789 * recycling on high speed LANs while still leaving over an hour 2790 * before rollover. 2791 * 2792 * As reading the *exact* system time is too expensive to be done 2793 * whenever setting up a TCP connection, we increment the time 2794 * offset in two ways. First, a small random positive increment 2795 * is added to isn_offset for each connection that is set up. 2796 * Second, the function tcp_isn_tick fires once per clock tick 2797 * and increments isn_offset as necessary so that sequence numbers 2798 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2799 * random positive increments serve only to ensure that the same 2800 * exact sequence number is never sent out twice (as could otherwise 2801 * happen when a port is recycled in less than the system tick 2802 * interval.) 2803 * 2804 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2805 * between seeding of isn_secret. This is normally set to zero, 2806 * as reseeding should not be necessary. 2807 * 2808 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2809 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2810 * general, this means holding an exclusive (write) lock. 2811 */ 2812 2813 #define ISN_BYTES_PER_SECOND 1048576 2814 #define ISN_STATIC_INCREMENT 4096 2815 #define ISN_RANDOM_INCREMENT (4096 - 1) 2816 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 2817 2818 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2819 VNET_DEFINE_STATIC(int, isn_last); 2820 VNET_DEFINE_STATIC(int, isn_last_reseed); 2821 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2822 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2823 2824 #define V_isn_secret VNET(isn_secret) 2825 #define V_isn_last VNET(isn_last) 2826 #define V_isn_last_reseed VNET(isn_last_reseed) 2827 #define V_isn_offset VNET(isn_offset) 2828 #define V_isn_offset_old VNET(isn_offset_old) 2829 2830 tcp_seq 2831 tcp_new_isn(struct in_conninfo *inc) 2832 { 2833 tcp_seq new_isn; 2834 u_int32_t projected_offset; 2835 2836 ISN_LOCK(); 2837 /* Seed if this is the first use, reseed if requested. */ 2838 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2839 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2840 < (u_int)ticks))) { 2841 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2842 V_isn_last_reseed = ticks; 2843 } 2844 2845 /* Compute the hash and return the ISN. */ 2846 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2847 sizeof(V_isn_secret)); 2848 V_isn_offset += ISN_STATIC_INCREMENT + 2849 (arc4random() & ISN_RANDOM_INCREMENT); 2850 if (ticks != V_isn_last) { 2851 projected_offset = V_isn_offset_old + 2852 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2853 if (SEQ_GT(projected_offset, V_isn_offset)) 2854 V_isn_offset = projected_offset; 2855 V_isn_offset_old = V_isn_offset; 2856 V_isn_last = ticks; 2857 } 2858 new_isn += V_isn_offset; 2859 ISN_UNLOCK(); 2860 return (new_isn); 2861 } 2862 2863 /* 2864 * When a specific ICMP unreachable message is received and the 2865 * connection state is SYN-SENT, drop the connection. This behavior 2866 * is controlled by the icmp_may_rst sysctl. 2867 */ 2868 struct inpcb * 2869 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2870 { 2871 struct tcpcb *tp; 2872 2873 NET_EPOCH_ASSERT(); 2874 INP_WLOCK_ASSERT(inp); 2875 2876 if ((inp->inp_flags & INP_TIMEWAIT) || 2877 (inp->inp_flags & INP_DROPPED)) 2878 return (inp); 2879 2880 tp = intotcpcb(inp); 2881 if (tp->t_state != TCPS_SYN_SENT) 2882 return (inp); 2883 2884 if (IS_FASTOPEN(tp->t_flags)) 2885 tcp_fastopen_disable_path(tp); 2886 2887 tp = tcp_drop(tp, errno); 2888 if (tp != NULL) 2889 return (inp); 2890 else 2891 return (NULL); 2892 } 2893 2894 /* 2895 * When `need fragmentation' ICMP is received, update our idea of the MSS 2896 * based on the new value. Also nudge TCP to send something, since we 2897 * know the packet we just sent was dropped. 2898 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2899 */ 2900 static struct inpcb * 2901 tcp_mtudisc_notify(struct inpcb *inp, int error) 2902 { 2903 2904 tcp_mtudisc(inp, -1); 2905 return (inp); 2906 } 2907 2908 static void 2909 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2910 { 2911 struct tcpcb *tp; 2912 struct socket *so; 2913 2914 INP_WLOCK_ASSERT(inp); 2915 if ((inp->inp_flags & INP_TIMEWAIT) || 2916 (inp->inp_flags & INP_DROPPED)) 2917 return; 2918 2919 tp = intotcpcb(inp); 2920 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2921 2922 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2923 2924 so = inp->inp_socket; 2925 SOCKBUF_LOCK(&so->so_snd); 2926 /* If the mss is larger than the socket buffer, decrease the mss. */ 2927 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2928 tp->t_maxseg = so->so_snd.sb_hiwat; 2929 SOCKBUF_UNLOCK(&so->so_snd); 2930 2931 TCPSTAT_INC(tcps_mturesent); 2932 tp->t_rtttime = 0; 2933 tp->snd_nxt = tp->snd_una; 2934 tcp_free_sackholes(tp); 2935 tp->snd_recover = tp->snd_max; 2936 if (tp->t_flags & TF_SACK_PERMIT) 2937 EXIT_FASTRECOVERY(tp->t_flags); 2938 tp->t_fb->tfb_tcp_output(tp); 2939 } 2940 2941 #ifdef INET 2942 /* 2943 * Look-up the routing entry to the peer of this inpcb. If no route 2944 * is found and it cannot be allocated, then return 0. This routine 2945 * is called by TCP routines that access the rmx structure and by 2946 * tcp_mss_update to get the peer/interface MTU. 2947 */ 2948 uint32_t 2949 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2950 { 2951 struct nhop_object *nh; 2952 struct ifnet *ifp; 2953 uint32_t maxmtu = 0; 2954 2955 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2956 2957 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2958 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 2959 if (nh == NULL) 2960 return (0); 2961 2962 ifp = nh->nh_ifp; 2963 maxmtu = nh->nh_mtu; 2964 2965 /* Report additional interface capabilities. */ 2966 if (cap != NULL) { 2967 if (ifp->if_capenable & IFCAP_TSO4 && 2968 ifp->if_hwassist & CSUM_TSO) { 2969 cap->ifcap |= CSUM_TSO; 2970 cap->tsomax = ifp->if_hw_tsomax; 2971 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2972 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2973 } 2974 } 2975 } 2976 return (maxmtu); 2977 } 2978 #endif /* INET */ 2979 2980 #ifdef INET6 2981 uint32_t 2982 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2983 { 2984 struct nhop_object *nh; 2985 struct in6_addr dst6; 2986 uint32_t scopeid; 2987 struct ifnet *ifp; 2988 uint32_t maxmtu = 0; 2989 2990 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2991 2992 if (inc->inc_flags & INC_IPV6MINMTU) 2993 return (IPV6_MMTU); 2994 2995 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2996 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2997 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 2998 if (nh == NULL) 2999 return (0); 3000 3001 ifp = nh->nh_ifp; 3002 maxmtu = nh->nh_mtu; 3003 3004 /* Report additional interface capabilities. */ 3005 if (cap != NULL) { 3006 if (ifp->if_capenable & IFCAP_TSO6 && 3007 ifp->if_hwassist & CSUM_TSO) { 3008 cap->ifcap |= CSUM_TSO; 3009 cap->tsomax = ifp->if_hw_tsomax; 3010 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3011 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3012 } 3013 } 3014 } 3015 3016 return (maxmtu); 3017 } 3018 #endif /* INET6 */ 3019 3020 /* 3021 * Calculate effective SMSS per RFC5681 definition for a given TCP 3022 * connection at its current state, taking into account SACK and etc. 3023 */ 3024 u_int 3025 tcp_maxseg(const struct tcpcb *tp) 3026 { 3027 u_int optlen; 3028 3029 if (tp->t_flags & TF_NOOPT) 3030 return (tp->t_maxseg); 3031 3032 /* 3033 * Here we have a simplified code from tcp_addoptions(), 3034 * without a proper loop, and having most of paddings hardcoded. 3035 * We might make mistakes with padding here in some edge cases, 3036 * but this is harmless, since result of tcp_maxseg() is used 3037 * only in cwnd and ssthresh estimations. 3038 */ 3039 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3040 if (tp->t_flags & TF_RCVD_TSTMP) 3041 optlen = TCPOLEN_TSTAMP_APPA; 3042 else 3043 optlen = 0; 3044 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3045 if (tp->t_flags & TF_SIGNATURE) 3046 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3047 #endif 3048 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3049 optlen += TCPOLEN_SACKHDR; 3050 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3051 optlen = PADTCPOLEN(optlen); 3052 } 3053 } else { 3054 if (tp->t_flags & TF_REQ_TSTMP) 3055 optlen = TCPOLEN_TSTAMP_APPA; 3056 else 3057 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3058 if (tp->t_flags & TF_REQ_SCALE) 3059 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3060 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3061 if (tp->t_flags & TF_SIGNATURE) 3062 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3063 #endif 3064 if (tp->t_flags & TF_SACK_PERMIT) 3065 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3066 } 3067 #undef PAD 3068 optlen = min(optlen, TCP_MAXOLEN); 3069 return (tp->t_maxseg - optlen); 3070 } 3071 3072 static int 3073 sysctl_drop(SYSCTL_HANDLER_ARGS) 3074 { 3075 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3076 struct sockaddr_storage addrs[2]; 3077 struct inpcb *inp; 3078 struct tcpcb *tp; 3079 struct tcptw *tw; 3080 struct sockaddr_in *fin, *lin; 3081 struct epoch_tracker et; 3082 #ifdef INET6 3083 struct sockaddr_in6 *fin6, *lin6; 3084 #endif 3085 int error; 3086 3087 inp = NULL; 3088 fin = lin = NULL; 3089 #ifdef INET6 3090 fin6 = lin6 = NULL; 3091 #endif 3092 error = 0; 3093 3094 if (req->oldptr != NULL || req->oldlen != 0) 3095 return (EINVAL); 3096 if (req->newptr == NULL) 3097 return (EPERM); 3098 if (req->newlen < sizeof(addrs)) 3099 return (ENOMEM); 3100 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3101 if (error) 3102 return (error); 3103 3104 switch (addrs[0].ss_family) { 3105 #ifdef INET6 3106 case AF_INET6: 3107 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3108 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3109 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3110 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3111 return (EINVAL); 3112 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3113 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3114 return (EINVAL); 3115 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3116 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3117 fin = (struct sockaddr_in *)&addrs[0]; 3118 lin = (struct sockaddr_in *)&addrs[1]; 3119 break; 3120 } 3121 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3122 if (error) 3123 return (error); 3124 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3125 if (error) 3126 return (error); 3127 break; 3128 #endif 3129 #ifdef INET 3130 case AF_INET: 3131 fin = (struct sockaddr_in *)&addrs[0]; 3132 lin = (struct sockaddr_in *)&addrs[1]; 3133 if (fin->sin_len != sizeof(struct sockaddr_in) || 3134 lin->sin_len != sizeof(struct sockaddr_in)) 3135 return (EINVAL); 3136 break; 3137 #endif 3138 default: 3139 return (EINVAL); 3140 } 3141 NET_EPOCH_ENTER(et); 3142 switch (addrs[0].ss_family) { 3143 #ifdef INET6 3144 case AF_INET6: 3145 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3146 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3147 INPLOOKUP_WLOCKPCB, NULL); 3148 break; 3149 #endif 3150 #ifdef INET 3151 case AF_INET: 3152 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3153 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3154 break; 3155 #endif 3156 } 3157 if (inp != NULL) { 3158 if (inp->inp_flags & INP_TIMEWAIT) { 3159 /* 3160 * XXXRW: There currently exists a state where an 3161 * inpcb is present, but its timewait state has been 3162 * discarded. For now, don't allow dropping of this 3163 * type of inpcb. 3164 */ 3165 tw = intotw(inp); 3166 if (tw != NULL) 3167 tcp_twclose(tw, 0); 3168 else 3169 INP_WUNLOCK(inp); 3170 } else if (!(inp->inp_flags & INP_DROPPED) && 3171 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3172 tp = intotcpcb(inp); 3173 tp = tcp_drop(tp, ECONNABORTED); 3174 if (tp != NULL) 3175 INP_WUNLOCK(inp); 3176 } else 3177 INP_WUNLOCK(inp); 3178 } else 3179 error = ESRCH; 3180 NET_EPOCH_EXIT(et); 3181 return (error); 3182 } 3183 3184 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3185 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3186 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3187 "Drop TCP connection"); 3188 3189 #ifdef KERN_TLS 3190 static int 3191 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3192 { 3193 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3194 struct sockaddr_storage addrs[2]; 3195 struct inpcb *inp; 3196 struct sockaddr_in *fin, *lin; 3197 struct epoch_tracker et; 3198 #ifdef INET6 3199 struct sockaddr_in6 *fin6, *lin6; 3200 #endif 3201 int error; 3202 3203 inp = NULL; 3204 fin = lin = NULL; 3205 #ifdef INET6 3206 fin6 = lin6 = NULL; 3207 #endif 3208 error = 0; 3209 3210 if (req->oldptr != NULL || req->oldlen != 0) 3211 return (EINVAL); 3212 if (req->newptr == NULL) 3213 return (EPERM); 3214 if (req->newlen < sizeof(addrs)) 3215 return (ENOMEM); 3216 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3217 if (error) 3218 return (error); 3219 3220 switch (addrs[0].ss_family) { 3221 #ifdef INET6 3222 case AF_INET6: 3223 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3224 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3225 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3226 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3227 return (EINVAL); 3228 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3229 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3230 return (EINVAL); 3231 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3232 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3233 fin = (struct sockaddr_in *)&addrs[0]; 3234 lin = (struct sockaddr_in *)&addrs[1]; 3235 break; 3236 } 3237 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3238 if (error) 3239 return (error); 3240 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3241 if (error) 3242 return (error); 3243 break; 3244 #endif 3245 #ifdef INET 3246 case AF_INET: 3247 fin = (struct sockaddr_in *)&addrs[0]; 3248 lin = (struct sockaddr_in *)&addrs[1]; 3249 if (fin->sin_len != sizeof(struct sockaddr_in) || 3250 lin->sin_len != sizeof(struct sockaddr_in)) 3251 return (EINVAL); 3252 break; 3253 #endif 3254 default: 3255 return (EINVAL); 3256 } 3257 NET_EPOCH_ENTER(et); 3258 switch (addrs[0].ss_family) { 3259 #ifdef INET6 3260 case AF_INET6: 3261 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3262 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3263 INPLOOKUP_WLOCKPCB, NULL); 3264 break; 3265 #endif 3266 #ifdef INET 3267 case AF_INET: 3268 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3269 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3270 break; 3271 #endif 3272 } 3273 NET_EPOCH_EXIT(et); 3274 if (inp != NULL) { 3275 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3276 inp->inp_socket == NULL) { 3277 error = ECONNRESET; 3278 INP_WUNLOCK(inp); 3279 } else { 3280 struct socket *so; 3281 3282 so = inp->inp_socket; 3283 soref(so); 3284 error = ktls_set_tx_mode(so, 3285 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3286 INP_WUNLOCK(inp); 3287 SOCK_LOCK(so); 3288 sorele(so); 3289 } 3290 } else 3291 error = ESRCH; 3292 return (error); 3293 } 3294 3295 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3296 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3297 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3298 "Switch TCP connection to SW TLS"); 3299 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3300 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3301 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3302 "Switch TCP connection to ifnet TLS"); 3303 #endif 3304 3305 /* 3306 * Generate a standardized TCP log line for use throughout the 3307 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3308 * allow use in the interrupt context. 3309 * 3310 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3311 * NB: The function may return NULL if memory allocation failed. 3312 * 3313 * Due to header inclusion and ordering limitations the struct ip 3314 * and ip6_hdr pointers have to be passed as void pointers. 3315 */ 3316 char * 3317 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3318 const void *ip6hdr) 3319 { 3320 3321 /* Is logging enabled? */ 3322 if (V_tcp_log_in_vain == 0) 3323 return (NULL); 3324 3325 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3326 } 3327 3328 char * 3329 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3330 const void *ip6hdr) 3331 { 3332 3333 /* Is logging enabled? */ 3334 if (tcp_log_debug == 0) 3335 return (NULL); 3336 3337 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3338 } 3339 3340 static char * 3341 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3342 const void *ip6hdr) 3343 { 3344 char *s, *sp; 3345 size_t size; 3346 struct ip *ip; 3347 #ifdef INET6 3348 const struct ip6_hdr *ip6; 3349 3350 ip6 = (const struct ip6_hdr *)ip6hdr; 3351 #endif /* INET6 */ 3352 ip = (struct ip *)ip4hdr; 3353 3354 /* 3355 * The log line looks like this: 3356 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3357 */ 3358 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3359 sizeof(PRINT_TH_FLAGS) + 1 + 3360 #ifdef INET6 3361 2 * INET6_ADDRSTRLEN; 3362 #else 3363 2 * INET_ADDRSTRLEN; 3364 #endif /* INET6 */ 3365 3366 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3367 if (s == NULL) 3368 return (NULL); 3369 3370 strcat(s, "TCP: ["); 3371 sp = s + strlen(s); 3372 3373 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3374 inet_ntoa_r(inc->inc_faddr, sp); 3375 sp = s + strlen(s); 3376 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3377 sp = s + strlen(s); 3378 inet_ntoa_r(inc->inc_laddr, sp); 3379 sp = s + strlen(s); 3380 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3381 #ifdef INET6 3382 } else if (inc) { 3383 ip6_sprintf(sp, &inc->inc6_faddr); 3384 sp = s + strlen(s); 3385 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3386 sp = s + strlen(s); 3387 ip6_sprintf(sp, &inc->inc6_laddr); 3388 sp = s + strlen(s); 3389 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3390 } else if (ip6 && th) { 3391 ip6_sprintf(sp, &ip6->ip6_src); 3392 sp = s + strlen(s); 3393 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3394 sp = s + strlen(s); 3395 ip6_sprintf(sp, &ip6->ip6_dst); 3396 sp = s + strlen(s); 3397 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3398 #endif /* INET6 */ 3399 #ifdef INET 3400 } else if (ip && th) { 3401 inet_ntoa_r(ip->ip_src, sp); 3402 sp = s + strlen(s); 3403 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3404 sp = s + strlen(s); 3405 inet_ntoa_r(ip->ip_dst, sp); 3406 sp = s + strlen(s); 3407 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3408 #endif /* INET */ 3409 } else { 3410 free(s, M_TCPLOG); 3411 return (NULL); 3412 } 3413 sp = s + strlen(s); 3414 if (th) 3415 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3416 if (*(s + size - 1) != '\0') 3417 panic("%s: string too long", __func__); 3418 return (s); 3419 } 3420 3421 /* 3422 * A subroutine which makes it easy to track TCP state changes with DTrace. 3423 * This function shouldn't be called for t_state initializations that don't 3424 * correspond to actual TCP state transitions. 3425 */ 3426 void 3427 tcp_state_change(struct tcpcb *tp, int newstate) 3428 { 3429 #if defined(KDTRACE_HOOKS) 3430 int pstate = tp->t_state; 3431 #endif 3432 3433 TCPSTATES_DEC(tp->t_state); 3434 TCPSTATES_INC(newstate); 3435 tp->t_state = newstate; 3436 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3437 } 3438 3439 /* 3440 * Create an external-format (``xtcpcb'') structure using the information in 3441 * the kernel-format tcpcb structure pointed to by tp. This is done to 3442 * reduce the spew of irrelevant information over this interface, to isolate 3443 * user code from changes in the kernel structure, and potentially to provide 3444 * information-hiding if we decide that some of this information should be 3445 * hidden from users. 3446 */ 3447 void 3448 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3449 { 3450 struct tcpcb *tp = intotcpcb(inp); 3451 sbintime_t now; 3452 3453 bzero(xt, sizeof(*xt)); 3454 if (inp->inp_flags & INP_TIMEWAIT) { 3455 xt->t_state = TCPS_TIME_WAIT; 3456 } else { 3457 xt->t_state = tp->t_state; 3458 xt->t_logstate = tp->t_logstate; 3459 xt->t_flags = tp->t_flags; 3460 xt->t_sndzerowin = tp->t_sndzerowin; 3461 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3462 xt->t_rcvoopack = tp->t_rcvoopack; 3463 xt->t_rcv_wnd = tp->rcv_wnd; 3464 xt->t_snd_wnd = tp->snd_wnd; 3465 xt->t_snd_cwnd = tp->snd_cwnd; 3466 xt->t_snd_ssthresh = tp->snd_ssthresh; 3467 xt->t_maxseg = tp->t_maxseg; 3468 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3469 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3470 3471 now = getsbinuptime(); 3472 #define COPYTIMER(ttt) do { \ 3473 if (callout_active(&tp->t_timers->ttt)) \ 3474 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3475 SBT_1MS; \ 3476 else \ 3477 xt->ttt = 0; \ 3478 } while (0) 3479 COPYTIMER(tt_delack); 3480 COPYTIMER(tt_rexmt); 3481 COPYTIMER(tt_persist); 3482 COPYTIMER(tt_keep); 3483 COPYTIMER(tt_2msl); 3484 #undef COPYTIMER 3485 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3486 3487 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3488 TCP_FUNCTION_NAME_LEN_MAX); 3489 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 3490 TCP_CA_NAME_MAX); 3491 #ifdef TCP_BLACKBOX 3492 (void)tcp_log_get_id(tp, xt->xt_logid); 3493 #endif 3494 } 3495 3496 xt->xt_len = sizeof(struct xtcpcb); 3497 in_pcbtoxinpcb(inp, &xt->xt_inp); 3498 if (inp->inp_socket == NULL) 3499 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3500 } 3501 3502 void 3503 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 3504 { 3505 uint32_t bit, i; 3506 3507 if ((tp == NULL) || 3508 (status > TCP_EI_STATUS_MAX_VALUE) || 3509 (status == 0)) { 3510 /* Invalid */ 3511 return; 3512 } 3513 if (status > (sizeof(uint32_t) * 8)) { 3514 /* Should this be a KASSERT? */ 3515 return; 3516 } 3517 bit = 1U << (status - 1); 3518 if (bit & tp->t_end_info_status) { 3519 /* already logged */ 3520 return; 3521 } 3522 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 3523 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 3524 tp->t_end_info_bytes[i] = status; 3525 tp->t_end_info_status |= bit; 3526 break; 3527 } 3528 } 3529 } 3530