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/if.h> 80 #include <net/if_var.h> 81 #include <net/vnet.h> 82 83 #include <netinet/in.h> 84 #include <netinet/in_fib.h> 85 #include <netinet/in_kdtrace.h> 86 #include <netinet/in_pcb.h> 87 #include <netinet/in_systm.h> 88 #include <netinet/in_var.h> 89 #include <netinet/ip.h> 90 #include <netinet/ip_icmp.h> 91 #include <netinet/ip_var.h> 92 #ifdef INET6 93 #include <netinet/icmp6.h> 94 #include <netinet/ip6.h> 95 #include <netinet6/in6_fib.h> 96 #include <netinet6/in6_pcb.h> 97 #include <netinet6/ip6_var.h> 98 #include <netinet6/scope6_var.h> 99 #include <netinet6/nd6.h> 100 #endif 101 102 #include <netinet/tcp.h> 103 #include <netinet/tcp_fsm.h> 104 #include <netinet/tcp_seq.h> 105 #include <netinet/tcp_timer.h> 106 #include <netinet/tcp_var.h> 107 #include <netinet/tcp_log_buf.h> 108 #include <netinet/tcp_syncache.h> 109 #include <netinet/tcp_hpts.h> 110 #include <netinet/cc/cc.h> 111 #ifdef INET6 112 #include <netinet6/tcp6_var.h> 113 #endif 114 #include <netinet/tcpip.h> 115 #include <netinet/tcp_fastopen.h> 116 #ifdef TCPPCAP 117 #include <netinet/tcp_pcap.h> 118 #endif 119 #ifdef TCPDEBUG 120 #include <netinet/tcp_debug.h> 121 #endif 122 #ifdef INET6 123 #include <netinet6/ip6protosw.h> 124 #endif 125 #ifdef TCP_OFFLOAD 126 #include <netinet/tcp_offload.h> 127 #endif 128 129 #include <netipsec/ipsec_support.h> 130 131 #include <machine/in_cksum.h> 132 #include <crypto/siphash/siphash.h> 133 134 #include <security/mac/mac_framework.h> 135 136 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 137 #ifdef INET6 138 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 139 #endif 140 141 #ifdef NETFLIX_EXP_DETECTION 142 /* Sack attack detection thresholds and such */ 143 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, CTLFLAG_RW, 0, 144 "Sack Attack detection thresholds"); 145 int32_t tcp_force_detection = 0; 146 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 147 CTLFLAG_RW, 148 &tcp_force_detection, 0, 149 "Do we force detection even if the INP has it off?"); 150 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 151 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 152 CTLFLAG_RW, 153 &tcp_sack_to_ack_thresh, 700, 154 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 155 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 156 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 157 CTLFLAG_RW, 158 &tcp_sack_to_move_thresh, 600, 159 "Percentage of sack moves we must see above (10.1 percent is 101)"); 160 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 161 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 162 CTLFLAG_RW, 163 &tcp_restoral_thresh, 550, 164 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 165 int32_t tcp_sad_decay_val = 800; 166 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 167 CTLFLAG_RW, 168 &tcp_sad_decay_val, 800, 169 "The decay percentage (10.1 percent equals 101 )"); 170 int32_t tcp_map_minimum = 500; 171 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 172 CTLFLAG_RW, 173 &tcp_map_minimum, 500, 174 "Number of Map enteries before we start detection"); 175 int32_t tcp_attack_on_turns_on_logging = 0; 176 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 177 CTLFLAG_RW, 178 &tcp_attack_on_turns_on_logging, 0, 179 "When we have a positive hit on attack, do we turn on logging?"); 180 int32_t tcp_sad_pacing_interval = 2000; 181 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 182 CTLFLAG_RW, 183 &tcp_sad_pacing_interval, 2000, 184 "What is the minimum pacing interval for a classified attacker?"); 185 186 int32_t tcp_sad_low_pps = 100; 187 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 188 CTLFLAG_RW, 189 &tcp_sad_low_pps, 100, 190 "What is the input pps that below which we do not decay?"); 191 #endif 192 193 struct rwlock tcp_function_lock; 194 195 static int 196 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 197 { 198 int error, new; 199 200 new = V_tcp_mssdflt; 201 error = sysctl_handle_int(oidp, &new, 0, req); 202 if (error == 0 && req->newptr) { 203 if (new < TCP_MINMSS) 204 error = EINVAL; 205 else 206 V_tcp_mssdflt = new; 207 } 208 return (error); 209 } 210 211 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 212 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 213 &sysctl_net_inet_tcp_mss_check, "I", 214 "Default TCP Maximum Segment Size"); 215 216 #ifdef INET6 217 static int 218 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 219 { 220 int error, new; 221 222 new = V_tcp_v6mssdflt; 223 error = sysctl_handle_int(oidp, &new, 0, req); 224 if (error == 0 && req->newptr) { 225 if (new < TCP_MINMSS) 226 error = EINVAL; 227 else 228 V_tcp_v6mssdflt = new; 229 } 230 return (error); 231 } 232 233 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 234 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 235 &sysctl_net_inet_tcp_mss_v6_check, "I", 236 "Default TCP Maximum Segment Size for IPv6"); 237 #endif /* INET6 */ 238 239 /* 240 * Minimum MSS we accept and use. This prevents DoS attacks where 241 * we are forced to a ridiculous low MSS like 20 and send hundreds 242 * of packets instead of one. The effect scales with the available 243 * bandwidth and quickly saturates the CPU and network interface 244 * with packet generation and sending. Set to zero to disable MINMSS 245 * checking. This setting prevents us from sending too small packets. 246 */ 247 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 248 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 249 &VNET_NAME(tcp_minmss), 0, 250 "Minimum TCP Maximum Segment Size"); 251 252 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 253 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 254 &VNET_NAME(tcp_do_rfc1323), 0, 255 "Enable rfc1323 (high performance TCP) extensions"); 256 257 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 258 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 259 &VNET_NAME(tcp_ts_offset_per_conn), 0, 260 "Initialize TCP timestamps per connection instead of per host pair"); 261 262 static int tcp_log_debug = 0; 263 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 264 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 265 266 static int tcp_tcbhashsize; 267 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 268 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 269 270 static int do_tcpdrain = 1; 271 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 272 "Enable tcp_drain routine for extra help when low on mbufs"); 273 274 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 275 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 276 277 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 278 #define V_icmp_may_rst VNET(icmp_may_rst) 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 280 &VNET_NAME(icmp_may_rst), 0, 281 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 282 283 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 284 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 285 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 286 &VNET_NAME(tcp_isn_reseed_interval), 0, 287 "Seconds between reseeding of ISN secret"); 288 289 static int tcp_soreceive_stream; 290 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 291 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 292 293 VNET_DEFINE(uma_zone_t, sack_hole_zone); 294 #define V_sack_hole_zone VNET(sack_hole_zone) 295 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 296 static int 297 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 298 { 299 int error; 300 uint32_t new; 301 302 new = V_tcp_map_entries_limit; 303 error = sysctl_handle_int(oidp, &new, 0, req); 304 if (error == 0 && req->newptr) { 305 /* only allow "0" and value > minimum */ 306 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 307 error = EINVAL; 308 else 309 V_tcp_map_entries_limit = new; 310 } 311 return (error); 312 } 313 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 314 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 315 &VNET_NAME(tcp_map_entries_limit), 0, 316 &sysctl_net_inet_tcp_map_limit_check, "IU", 317 "Total sendmap entries limit"); 318 319 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 320 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 321 &VNET_NAME(tcp_map_split_limit), 0, 322 "Total sendmap split entries limit"); 323 324 #ifdef TCP_HHOOK 325 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 326 #endif 327 328 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 329 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 330 #define V_ts_offset_secret VNET(ts_offset_secret) 331 332 static int tcp_default_fb_init(struct tcpcb *tp); 333 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 334 static int tcp_default_handoff_ok(struct tcpcb *tp); 335 static struct inpcb *tcp_notify(struct inpcb *, int); 336 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 337 static void tcp_mtudisc(struct inpcb *, int); 338 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 339 void *ip4hdr, const void *ip6hdr); 340 341 342 static struct tcp_function_block tcp_def_funcblk = { 343 .tfb_tcp_block_name = "freebsd", 344 .tfb_tcp_output = tcp_output, 345 .tfb_tcp_do_segment = tcp_do_segment, 346 .tfb_tcp_ctloutput = tcp_default_ctloutput, 347 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 348 .tfb_tcp_fb_init = tcp_default_fb_init, 349 .tfb_tcp_fb_fini = tcp_default_fb_fini, 350 }; 351 352 static int tcp_fb_cnt = 0; 353 struct tcp_funchead t_functions; 354 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 355 356 static struct tcp_function_block * 357 find_tcp_functions_locked(struct tcp_function_set *fs) 358 { 359 struct tcp_function *f; 360 struct tcp_function_block *blk=NULL; 361 362 TAILQ_FOREACH(f, &t_functions, tf_next) { 363 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 364 blk = f->tf_fb; 365 break; 366 } 367 } 368 return(blk); 369 } 370 371 static struct tcp_function_block * 372 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 373 { 374 struct tcp_function_block *rblk=NULL; 375 struct tcp_function *f; 376 377 TAILQ_FOREACH(f, &t_functions, tf_next) { 378 if (f->tf_fb == blk) { 379 rblk = blk; 380 if (s) { 381 *s = f; 382 } 383 break; 384 } 385 } 386 return (rblk); 387 } 388 389 struct tcp_function_block * 390 find_and_ref_tcp_functions(struct tcp_function_set *fs) 391 { 392 struct tcp_function_block *blk; 393 394 rw_rlock(&tcp_function_lock); 395 blk = find_tcp_functions_locked(fs); 396 if (blk) 397 refcount_acquire(&blk->tfb_refcnt); 398 rw_runlock(&tcp_function_lock); 399 return(blk); 400 } 401 402 struct tcp_function_block * 403 find_and_ref_tcp_fb(struct tcp_function_block *blk) 404 { 405 struct tcp_function_block *rblk; 406 407 rw_rlock(&tcp_function_lock); 408 rblk = find_tcp_fb_locked(blk, NULL); 409 if (rblk) 410 refcount_acquire(&rblk->tfb_refcnt); 411 rw_runlock(&tcp_function_lock); 412 return(rblk); 413 } 414 415 static struct tcp_function_block * 416 find_and_ref_tcp_default_fb(void) 417 { 418 struct tcp_function_block *rblk; 419 420 rw_rlock(&tcp_function_lock); 421 rblk = tcp_func_set_ptr; 422 refcount_acquire(&rblk->tfb_refcnt); 423 rw_runlock(&tcp_function_lock); 424 return (rblk); 425 } 426 427 void 428 tcp_switch_back_to_default(struct tcpcb *tp) 429 { 430 struct tcp_function_block *tfb; 431 432 KASSERT(tp->t_fb != &tcp_def_funcblk, 433 ("%s: called by the built-in default stack", __func__)); 434 435 /* 436 * Release the old stack. This function will either find a new one 437 * or panic. 438 */ 439 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 440 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 441 refcount_release(&tp->t_fb->tfb_refcnt); 442 443 /* 444 * Now, we'll find a new function block to use. 445 * Start by trying the current user-selected 446 * default, unless this stack is the user-selected 447 * default. 448 */ 449 tfb = find_and_ref_tcp_default_fb(); 450 if (tfb == tp->t_fb) { 451 refcount_release(&tfb->tfb_refcnt); 452 tfb = NULL; 453 } 454 /* Does the stack accept this connection? */ 455 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 456 (*tfb->tfb_tcp_handoff_ok)(tp)) { 457 refcount_release(&tfb->tfb_refcnt); 458 tfb = NULL; 459 } 460 /* Try to use that stack. */ 461 if (tfb != NULL) { 462 /* Initialize the new stack. If it succeeds, we are done. */ 463 tp->t_fb = tfb; 464 if (tp->t_fb->tfb_tcp_fb_init == NULL || 465 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 466 return; 467 468 /* 469 * Initialization failed. Release the reference count on 470 * the stack. 471 */ 472 refcount_release(&tfb->tfb_refcnt); 473 } 474 475 /* 476 * If that wasn't feasible, use the built-in default 477 * stack which is not allowed to reject anyone. 478 */ 479 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 480 if (tfb == NULL) { 481 /* there always should be a default */ 482 panic("Can't refer to tcp_def_funcblk"); 483 } 484 if (tfb->tfb_tcp_handoff_ok != NULL) { 485 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 486 /* The default stack cannot say no */ 487 panic("Default stack rejects a new session?"); 488 } 489 } 490 tp->t_fb = tfb; 491 if (tp->t_fb->tfb_tcp_fb_init != NULL && 492 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 493 /* The default stack cannot fail */ 494 panic("Default stack initialization failed"); 495 } 496 } 497 498 static int 499 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 500 { 501 int error=ENOENT; 502 struct tcp_function_set fs; 503 struct tcp_function_block *blk; 504 505 memset(&fs, 0, sizeof(fs)); 506 rw_rlock(&tcp_function_lock); 507 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 508 if (blk) { 509 /* Found him */ 510 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 511 fs.pcbcnt = blk->tfb_refcnt; 512 } 513 rw_runlock(&tcp_function_lock); 514 error = sysctl_handle_string(oidp, fs.function_set_name, 515 sizeof(fs.function_set_name), req); 516 517 /* Check for error or no change */ 518 if (error != 0 || req->newptr == NULL) 519 return(error); 520 521 rw_wlock(&tcp_function_lock); 522 blk = find_tcp_functions_locked(&fs); 523 if ((blk == NULL) || 524 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 525 error = ENOENT; 526 goto done; 527 } 528 tcp_func_set_ptr = blk; 529 done: 530 rw_wunlock(&tcp_function_lock); 531 return (error); 532 } 533 534 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 535 CTLTYPE_STRING | CTLFLAG_RW, 536 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 537 "Set/get the default TCP functions"); 538 539 static int 540 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 541 { 542 int error, cnt, linesz; 543 struct tcp_function *f; 544 char *buffer, *cp; 545 size_t bufsz, outsz; 546 bool alias; 547 548 cnt = 0; 549 rw_rlock(&tcp_function_lock); 550 TAILQ_FOREACH(f, &t_functions, tf_next) { 551 cnt++; 552 } 553 rw_runlock(&tcp_function_lock); 554 555 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 556 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 557 558 error = 0; 559 cp = buffer; 560 561 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 562 "Alias", "PCB count"); 563 cp += linesz; 564 bufsz -= linesz; 565 outsz = linesz; 566 567 rw_rlock(&tcp_function_lock); 568 TAILQ_FOREACH(f, &t_functions, tf_next) { 569 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 570 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 571 f->tf_fb->tfb_tcp_block_name, 572 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 573 alias ? f->tf_name : "-", 574 f->tf_fb->tfb_refcnt); 575 if (linesz >= bufsz) { 576 error = EOVERFLOW; 577 break; 578 } 579 cp += linesz; 580 bufsz -= linesz; 581 outsz += linesz; 582 } 583 rw_runlock(&tcp_function_lock); 584 if (error == 0) 585 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 586 free(buffer, M_TEMP); 587 return (error); 588 } 589 590 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 591 CTLTYPE_STRING|CTLFLAG_RD, 592 NULL, 0, sysctl_net_inet_list_available, "A", 593 "list available TCP Function sets"); 594 595 /* 596 * Exports one (struct tcp_function_info) for each alias/name. 597 */ 598 static int 599 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 600 { 601 int cnt, error; 602 struct tcp_function *f; 603 struct tcp_function_info tfi; 604 605 /* 606 * We don't allow writes. 607 */ 608 if (req->newptr != NULL) 609 return (EINVAL); 610 611 /* 612 * Wire the old buffer so we can directly copy the functions to 613 * user space without dropping the lock. 614 */ 615 if (req->oldptr != NULL) { 616 error = sysctl_wire_old_buffer(req, 0); 617 if (error) 618 return (error); 619 } 620 621 /* 622 * Walk the list and copy out matching entries. If INVARIANTS 623 * is compiled in, also walk the list to verify the length of 624 * the list matches what we have recorded. 625 */ 626 rw_rlock(&tcp_function_lock); 627 628 cnt = 0; 629 #ifndef INVARIANTS 630 if (req->oldptr == NULL) { 631 cnt = tcp_fb_cnt; 632 goto skip_loop; 633 } 634 #endif 635 TAILQ_FOREACH(f, &t_functions, tf_next) { 636 #ifdef INVARIANTS 637 cnt++; 638 #endif 639 if (req->oldptr != NULL) { 640 bzero(&tfi, sizeof(tfi)); 641 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 642 tfi.tfi_id = f->tf_fb->tfb_id; 643 (void)strlcpy(tfi.tfi_alias, f->tf_name, 644 sizeof(tfi.tfi_alias)); 645 (void)strlcpy(tfi.tfi_name, 646 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 647 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 648 /* 649 * Don't stop on error, as that is the 650 * mechanism we use to accumulate length 651 * information if the buffer was too short. 652 */ 653 } 654 } 655 KASSERT(cnt == tcp_fb_cnt, 656 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 657 #ifndef INVARIANTS 658 skip_loop: 659 #endif 660 rw_runlock(&tcp_function_lock); 661 if (req->oldptr == NULL) 662 error = SYSCTL_OUT(req, NULL, 663 (cnt + 1) * sizeof(struct tcp_function_info)); 664 665 return (error); 666 } 667 668 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 669 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 670 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 671 "List TCP function block name-to-ID mappings"); 672 673 /* 674 * tfb_tcp_handoff_ok() function for the default stack. 675 * Note that we'll basically try to take all comers. 676 */ 677 static int 678 tcp_default_handoff_ok(struct tcpcb *tp) 679 { 680 681 return (0); 682 } 683 684 /* 685 * tfb_tcp_fb_init() function for the default stack. 686 * 687 * This handles making sure we have appropriate timers set if you are 688 * transitioning a socket that has some amount of setup done. 689 * 690 * The init() fuction from the default can *never* return non-zero i.e. 691 * it is required to always succeed since it is the stack of last resort! 692 */ 693 static int 694 tcp_default_fb_init(struct tcpcb *tp) 695 { 696 697 struct socket *so; 698 699 INP_WLOCK_ASSERT(tp->t_inpcb); 700 701 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 702 ("%s: connection %p in unexpected state %d", __func__, tp, 703 tp->t_state)); 704 705 /* 706 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 707 * know what to do for unexpected states (which includes TIME_WAIT). 708 */ 709 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 710 return (0); 711 712 /* 713 * Make sure some kind of transmission timer is set if there is 714 * outstanding data. 715 */ 716 so = tp->t_inpcb->inp_socket; 717 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 718 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 719 tcp_timer_active(tp, TT_PERSIST))) { 720 /* 721 * If the session has established and it looks like it should 722 * be in the persist state, set the persist timer. Otherwise, 723 * set the retransmit timer. 724 */ 725 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 726 (int32_t)(tp->snd_nxt - tp->snd_una) < 727 (int32_t)sbavail(&so->so_snd)) 728 tcp_setpersist(tp); 729 else 730 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 731 } 732 733 /* All non-embryonic sessions get a keepalive timer. */ 734 if (!tcp_timer_active(tp, TT_KEEP)) 735 tcp_timer_activate(tp, TT_KEEP, 736 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 737 TP_KEEPINIT(tp)); 738 739 return (0); 740 } 741 742 /* 743 * tfb_tcp_fb_fini() function for the default stack. 744 * 745 * This changes state as necessary (or prudent) to prepare for another stack 746 * to assume responsibility for the connection. 747 */ 748 static void 749 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 750 { 751 752 INP_WLOCK_ASSERT(tp->t_inpcb); 753 return; 754 } 755 756 /* 757 * Target size of TCP PCB hash tables. Must be a power of two. 758 * 759 * Note that this can be overridden by the kernel environment 760 * variable net.inet.tcp.tcbhashsize 761 */ 762 #ifndef TCBHASHSIZE 763 #define TCBHASHSIZE 0 764 #endif 765 766 /* 767 * XXX 768 * Callouts should be moved into struct tcp directly. They are currently 769 * separate because the tcpcb structure is exported to userland for sysctl 770 * parsing purposes, which do not know about callouts. 771 */ 772 struct tcpcb_mem { 773 struct tcpcb tcb; 774 struct tcp_timer tt; 775 struct cc_var ccv; 776 #ifdef TCP_HHOOK 777 struct osd osd; 778 #endif 779 }; 780 781 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 782 #define V_tcpcb_zone VNET(tcpcb_zone) 783 784 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 785 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 786 787 static struct mtx isn_mtx; 788 789 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 790 #define ISN_LOCK() mtx_lock(&isn_mtx) 791 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 792 793 /* 794 * TCP initialization. 795 */ 796 static void 797 tcp_zone_change(void *tag) 798 { 799 800 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 801 uma_zone_set_max(V_tcpcb_zone, maxsockets); 802 tcp_tw_zone_change(); 803 } 804 805 static int 806 tcp_inpcb_init(void *mem, int size, int flags) 807 { 808 struct inpcb *inp = mem; 809 810 INP_LOCK_INIT(inp, "inp", "tcpinp"); 811 return (0); 812 } 813 814 /* 815 * Take a value and get the next power of 2 that doesn't overflow. 816 * Used to size the tcp_inpcb hash buckets. 817 */ 818 static int 819 maketcp_hashsize(int size) 820 { 821 int hashsize; 822 823 /* 824 * auto tune. 825 * get the next power of 2 higher than maxsockets. 826 */ 827 hashsize = 1 << fls(size); 828 /* catch overflow, and just go one power of 2 smaller */ 829 if (hashsize < size) { 830 hashsize = 1 << (fls(size) - 1); 831 } 832 return (hashsize); 833 } 834 835 static volatile int next_tcp_stack_id = 1; 836 837 /* 838 * Register a TCP function block with the name provided in the names 839 * array. (Note that this function does NOT automatically register 840 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 841 * explicitly include blk->tfb_tcp_block_name in the list of names if 842 * you wish to register the stack with that name.) 843 * 844 * Either all name registrations will succeed or all will fail. If 845 * a name registration fails, the function will update the num_names 846 * argument to point to the array index of the name that encountered 847 * the failure. 848 * 849 * Returns 0 on success, or an error code on failure. 850 */ 851 int 852 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 853 const char *names[], int *num_names) 854 { 855 struct tcp_function *n; 856 struct tcp_function_set fs; 857 int error, i; 858 859 KASSERT(names != NULL && *num_names > 0, 860 ("%s: Called with 0-length name list", __func__)); 861 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 862 KASSERT(rw_initialized(&tcp_function_lock), 863 ("%s: called too early", __func__)); 864 865 if ((blk->tfb_tcp_output == NULL) || 866 (blk->tfb_tcp_do_segment == NULL) || 867 (blk->tfb_tcp_ctloutput == NULL) || 868 (strlen(blk->tfb_tcp_block_name) == 0)) { 869 /* 870 * These functions are required and you 871 * need a name. 872 */ 873 *num_names = 0; 874 return (EINVAL); 875 } 876 if (blk->tfb_tcp_timer_stop_all || 877 blk->tfb_tcp_timer_activate || 878 blk->tfb_tcp_timer_active || 879 blk->tfb_tcp_timer_stop) { 880 /* 881 * If you define one timer function you 882 * must have them all. 883 */ 884 if ((blk->tfb_tcp_timer_stop_all == NULL) || 885 (blk->tfb_tcp_timer_activate == NULL) || 886 (blk->tfb_tcp_timer_active == NULL) || 887 (blk->tfb_tcp_timer_stop == NULL)) { 888 *num_names = 0; 889 return (EINVAL); 890 } 891 } 892 893 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 894 *num_names = 0; 895 return (EINVAL); 896 } 897 898 refcount_init(&blk->tfb_refcnt, 0); 899 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 900 for (i = 0; i < *num_names; i++) { 901 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 902 if (n == NULL) { 903 error = ENOMEM; 904 goto cleanup; 905 } 906 n->tf_fb = blk; 907 908 (void)strlcpy(fs.function_set_name, names[i], 909 sizeof(fs.function_set_name)); 910 rw_wlock(&tcp_function_lock); 911 if (find_tcp_functions_locked(&fs) != NULL) { 912 /* Duplicate name space not allowed */ 913 rw_wunlock(&tcp_function_lock); 914 free(n, M_TCPFUNCTIONS); 915 error = EALREADY; 916 goto cleanup; 917 } 918 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 919 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 920 tcp_fb_cnt++; 921 rw_wunlock(&tcp_function_lock); 922 } 923 return(0); 924 925 cleanup: 926 /* 927 * Deregister the names we just added. Because registration failed 928 * for names[i], we don't need to deregister that name. 929 */ 930 *num_names = i; 931 rw_wlock(&tcp_function_lock); 932 while (--i >= 0) { 933 TAILQ_FOREACH(n, &t_functions, tf_next) { 934 if (!strncmp(n->tf_name, names[i], 935 TCP_FUNCTION_NAME_LEN_MAX)) { 936 TAILQ_REMOVE(&t_functions, n, tf_next); 937 tcp_fb_cnt--; 938 n->tf_fb = NULL; 939 free(n, M_TCPFUNCTIONS); 940 break; 941 } 942 } 943 } 944 rw_wunlock(&tcp_function_lock); 945 return (error); 946 } 947 948 /* 949 * Register a TCP function block using the name provided in the name 950 * argument. 951 * 952 * Returns 0 on success, or an error code on failure. 953 */ 954 int 955 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 956 int wait) 957 { 958 const char *name_list[1]; 959 int num_names, rv; 960 961 num_names = 1; 962 if (name != NULL) 963 name_list[0] = name; 964 else 965 name_list[0] = blk->tfb_tcp_block_name; 966 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 967 return (rv); 968 } 969 970 /* 971 * Register a TCP function block using the name defined in 972 * blk->tfb_tcp_block_name. 973 * 974 * Returns 0 on success, or an error code on failure. 975 */ 976 int 977 register_tcp_functions(struct tcp_function_block *blk, int wait) 978 { 979 980 return (register_tcp_functions_as_name(blk, NULL, wait)); 981 } 982 983 /* 984 * Deregister all names associated with a function block. This 985 * functionally removes the function block from use within the system. 986 * 987 * When called with a true quiesce argument, mark the function block 988 * as being removed so no more stacks will use it and determine 989 * whether the removal would succeed. 990 * 991 * When called with a false quiesce argument, actually attempt the 992 * removal. 993 * 994 * When called with a force argument, attempt to switch all TCBs to 995 * use the default stack instead of returning EBUSY. 996 * 997 * Returns 0 on success (or if the removal would succeed, or an error 998 * code on failure. 999 */ 1000 int 1001 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1002 bool force) 1003 { 1004 struct tcp_function *f; 1005 1006 if (blk == &tcp_def_funcblk) { 1007 /* You can't un-register the default */ 1008 return (EPERM); 1009 } 1010 rw_wlock(&tcp_function_lock); 1011 if (blk == tcp_func_set_ptr) { 1012 /* You can't free the current default */ 1013 rw_wunlock(&tcp_function_lock); 1014 return (EBUSY); 1015 } 1016 /* Mark the block so no more stacks can use it. */ 1017 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1018 /* 1019 * If TCBs are still attached to the stack, attempt to switch them 1020 * to the default stack. 1021 */ 1022 if (force && blk->tfb_refcnt) { 1023 struct inpcb *inp; 1024 struct tcpcb *tp; 1025 VNET_ITERATOR_DECL(vnet_iter); 1026 1027 rw_wunlock(&tcp_function_lock); 1028 1029 VNET_LIST_RLOCK(); 1030 VNET_FOREACH(vnet_iter) { 1031 CURVNET_SET(vnet_iter); 1032 INP_INFO_WLOCK(&V_tcbinfo); 1033 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1034 INP_WLOCK(inp); 1035 if (inp->inp_flags & INP_TIMEWAIT) { 1036 INP_WUNLOCK(inp); 1037 continue; 1038 } 1039 tp = intotcpcb(inp); 1040 if (tp == NULL || tp->t_fb != blk) { 1041 INP_WUNLOCK(inp); 1042 continue; 1043 } 1044 tcp_switch_back_to_default(tp); 1045 INP_WUNLOCK(inp); 1046 } 1047 INP_INFO_WUNLOCK(&V_tcbinfo); 1048 CURVNET_RESTORE(); 1049 } 1050 VNET_LIST_RUNLOCK(); 1051 1052 rw_wlock(&tcp_function_lock); 1053 } 1054 if (blk->tfb_refcnt) { 1055 /* TCBs still attached. */ 1056 rw_wunlock(&tcp_function_lock); 1057 return (EBUSY); 1058 } 1059 if (quiesce) { 1060 /* Skip removal. */ 1061 rw_wunlock(&tcp_function_lock); 1062 return (0); 1063 } 1064 /* Remove any function names that map to this function block. */ 1065 while (find_tcp_fb_locked(blk, &f) != NULL) { 1066 TAILQ_REMOVE(&t_functions, f, tf_next); 1067 tcp_fb_cnt--; 1068 f->tf_fb = NULL; 1069 free(f, M_TCPFUNCTIONS); 1070 } 1071 rw_wunlock(&tcp_function_lock); 1072 return (0); 1073 } 1074 1075 void 1076 tcp_init(void) 1077 { 1078 const char *tcbhash_tuneable; 1079 int hashsize; 1080 1081 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1082 1083 #ifdef TCP_HHOOK 1084 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1085 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1086 printf("%s: WARNING: unable to register helper hook\n", __func__); 1087 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1088 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1089 printf("%s: WARNING: unable to register helper hook\n", __func__); 1090 #endif 1091 #ifdef STATS 1092 if (tcp_stats_init()) 1093 printf("%s: WARNING: unable to initialise TCP stats\n", 1094 __func__); 1095 #endif 1096 hashsize = TCBHASHSIZE; 1097 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1098 if (hashsize == 0) { 1099 /* 1100 * Auto tune the hash size based on maxsockets. 1101 * A perfect hash would have a 1:1 mapping 1102 * (hashsize = maxsockets) however it's been 1103 * suggested that O(2) average is better. 1104 */ 1105 hashsize = maketcp_hashsize(maxsockets / 4); 1106 /* 1107 * Our historical default is 512, 1108 * do not autotune lower than this. 1109 */ 1110 if (hashsize < 512) 1111 hashsize = 512; 1112 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1113 printf("%s: %s auto tuned to %d\n", __func__, 1114 tcbhash_tuneable, hashsize); 1115 } 1116 /* 1117 * We require a hashsize to be a power of two. 1118 * Previously if it was not a power of two we would just reset it 1119 * back to 512, which could be a nasty surprise if you did not notice 1120 * the error message. 1121 * Instead what we do is clip it to the closest power of two lower 1122 * than the specified hash value. 1123 */ 1124 if (!powerof2(hashsize)) { 1125 int oldhashsize = hashsize; 1126 1127 hashsize = maketcp_hashsize(hashsize); 1128 /* prevent absurdly low value */ 1129 if (hashsize < 16) 1130 hashsize = 16; 1131 printf("%s: WARNING: TCB hash size not a power of 2, " 1132 "clipped from %d to %d.\n", __func__, oldhashsize, 1133 hashsize); 1134 } 1135 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1136 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1137 1138 /* 1139 * These have to be type stable for the benefit of the timers. 1140 */ 1141 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1142 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1143 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1144 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1145 1146 tcp_tw_init(); 1147 syncache_init(); 1148 tcp_hc_init(); 1149 1150 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1151 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1152 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1153 1154 tcp_fastopen_init(); 1155 1156 /* Skip initialization of globals for non-default instances. */ 1157 if (!IS_DEFAULT_VNET(curvnet)) 1158 return; 1159 1160 tcp_reass_global_init(); 1161 1162 /* XXX virtualize those bellow? */ 1163 tcp_delacktime = TCPTV_DELACK; 1164 tcp_keepinit = TCPTV_KEEP_INIT; 1165 tcp_keepidle = TCPTV_KEEP_IDLE; 1166 tcp_keepintvl = TCPTV_KEEPINTVL; 1167 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1168 tcp_msl = TCPTV_MSL; 1169 tcp_rexmit_initial = TCPTV_RTOBASE; 1170 if (tcp_rexmit_initial < 1) 1171 tcp_rexmit_initial = 1; 1172 tcp_rexmit_min = TCPTV_MIN; 1173 if (tcp_rexmit_min < 1) 1174 tcp_rexmit_min = 1; 1175 tcp_persmin = TCPTV_PERSMIN; 1176 tcp_persmax = TCPTV_PERSMAX; 1177 tcp_rexmit_slop = TCPTV_CPU_VAR; 1178 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1179 tcp_tcbhashsize = hashsize; 1180 1181 /* Setup the tcp function block list */ 1182 TAILQ_INIT(&t_functions); 1183 rw_init(&tcp_function_lock, "tcp_func_lock"); 1184 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1185 #ifdef TCP_BLACKBOX 1186 /* Initialize the TCP logging data. */ 1187 tcp_log_init(); 1188 #endif 1189 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1190 1191 if (tcp_soreceive_stream) { 1192 #ifdef INET 1193 tcp_usrreqs.pru_soreceive = soreceive_stream; 1194 #endif 1195 #ifdef INET6 1196 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1197 #endif /* INET6 */ 1198 } 1199 1200 #ifdef INET6 1201 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1202 #else /* INET6 */ 1203 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1204 #endif /* INET6 */ 1205 if (max_protohdr < TCP_MINPROTOHDR) 1206 max_protohdr = TCP_MINPROTOHDR; 1207 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1208 panic("tcp_init"); 1209 #undef TCP_MINPROTOHDR 1210 1211 ISN_LOCK_INIT(); 1212 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1213 SHUTDOWN_PRI_DEFAULT); 1214 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1215 EVENTHANDLER_PRI_ANY); 1216 1217 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1218 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1219 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1220 tcp_inp_lro_single_push = counter_u64_alloc(M_WAITOK); 1221 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1222 tcp_inp_lro_sack_wake = counter_u64_alloc(M_WAITOK); 1223 #ifdef TCPPCAP 1224 tcp_pcap_init(); 1225 #endif 1226 } 1227 1228 #ifdef VIMAGE 1229 static void 1230 tcp_destroy(void *unused __unused) 1231 { 1232 int n; 1233 #ifdef TCP_HHOOK 1234 int error; 1235 #endif 1236 1237 /* 1238 * All our processes are gone, all our sockets should be cleaned 1239 * up, which means, we should be past the tcp_discardcb() calls. 1240 * Sleep to let all tcpcb timers really disappear and cleanup. 1241 */ 1242 for (;;) { 1243 INP_LIST_RLOCK(&V_tcbinfo); 1244 n = V_tcbinfo.ipi_count; 1245 INP_LIST_RUNLOCK(&V_tcbinfo); 1246 if (n == 0) 1247 break; 1248 pause("tcpdes", hz / 10); 1249 } 1250 tcp_hc_destroy(); 1251 syncache_destroy(); 1252 tcp_tw_destroy(); 1253 in_pcbinfo_destroy(&V_tcbinfo); 1254 /* tcp_discardcb() clears the sack_holes up. */ 1255 uma_zdestroy(V_sack_hole_zone); 1256 uma_zdestroy(V_tcpcb_zone); 1257 1258 /* 1259 * Cannot free the zone until all tcpcbs are released as we attach 1260 * the allocations to them. 1261 */ 1262 tcp_fastopen_destroy(); 1263 1264 #ifdef TCP_HHOOK 1265 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1266 if (error != 0) { 1267 printf("%s: WARNING: unable to deregister helper hook " 1268 "type=%d, id=%d: error %d returned\n", __func__, 1269 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1270 } 1271 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1272 if (error != 0) { 1273 printf("%s: WARNING: unable to deregister helper hook " 1274 "type=%d, id=%d: error %d returned\n", __func__, 1275 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1276 } 1277 #endif 1278 } 1279 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1280 #endif 1281 1282 void 1283 tcp_fini(void *xtp) 1284 { 1285 1286 } 1287 1288 /* 1289 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1290 * tcp_template used to store this data in mbufs, but we now recopy it out 1291 * of the tcpcb each time to conserve mbufs. 1292 */ 1293 void 1294 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 1295 { 1296 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1297 1298 INP_WLOCK_ASSERT(inp); 1299 1300 #ifdef INET6 1301 if ((inp->inp_vflag & INP_IPV6) != 0) { 1302 struct ip6_hdr *ip6; 1303 1304 ip6 = (struct ip6_hdr *)ip_ptr; 1305 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1306 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1307 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1308 (IPV6_VERSION & IPV6_VERSION_MASK); 1309 ip6->ip6_nxt = IPPROTO_TCP; 1310 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1311 ip6->ip6_src = inp->in6p_laddr; 1312 ip6->ip6_dst = inp->in6p_faddr; 1313 } 1314 #endif /* INET6 */ 1315 #if defined(INET6) && defined(INET) 1316 else 1317 #endif 1318 #ifdef INET 1319 { 1320 struct ip *ip; 1321 1322 ip = (struct ip *)ip_ptr; 1323 ip->ip_v = IPVERSION; 1324 ip->ip_hl = 5; 1325 ip->ip_tos = inp->inp_ip_tos; 1326 ip->ip_len = 0; 1327 ip->ip_id = 0; 1328 ip->ip_off = 0; 1329 ip->ip_ttl = inp->inp_ip_ttl; 1330 ip->ip_sum = 0; 1331 ip->ip_p = IPPROTO_TCP; 1332 ip->ip_src = inp->inp_laddr; 1333 ip->ip_dst = inp->inp_faddr; 1334 } 1335 #endif /* INET */ 1336 th->th_sport = inp->inp_lport; 1337 th->th_dport = inp->inp_fport; 1338 th->th_seq = 0; 1339 th->th_ack = 0; 1340 th->th_x2 = 0; 1341 th->th_off = 5; 1342 th->th_flags = 0; 1343 th->th_win = 0; 1344 th->th_urp = 0; 1345 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1346 } 1347 1348 /* 1349 * Create template to be used to send tcp packets on a connection. 1350 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1351 * use for this function is in keepalives, which use tcp_respond. 1352 */ 1353 struct tcptemp * 1354 tcpip_maketemplate(struct inpcb *inp) 1355 { 1356 struct tcptemp *t; 1357 1358 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1359 if (t == NULL) 1360 return (NULL); 1361 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1362 return (t); 1363 } 1364 1365 /* 1366 * Send a single message to the TCP at address specified by 1367 * the given TCP/IP header. If m == NULL, then we make a copy 1368 * of the tcpiphdr at th and send directly to the addressed host. 1369 * This is used to force keep alive messages out using the TCP 1370 * template for a connection. If flags are given then we send 1371 * a message back to the TCP which originated the segment th, 1372 * and discard the mbuf containing it and any other attached mbufs. 1373 * 1374 * In any case the ack and sequence number of the transmitted 1375 * segment are as specified by the parameters. 1376 * 1377 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1378 */ 1379 void 1380 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1381 tcp_seq ack, tcp_seq seq, int flags) 1382 { 1383 struct tcpopt to; 1384 struct inpcb *inp; 1385 struct ip *ip; 1386 struct mbuf *optm; 1387 struct tcphdr *nth; 1388 u_char *optp; 1389 #ifdef INET6 1390 struct ip6_hdr *ip6; 1391 int isipv6; 1392 #endif /* INET6 */ 1393 int optlen, tlen, win; 1394 bool incl_opts; 1395 1396 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1397 1398 #ifdef INET6 1399 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1400 ip6 = ipgen; 1401 #endif /* INET6 */ 1402 ip = ipgen; 1403 1404 if (tp != NULL) { 1405 inp = tp->t_inpcb; 1406 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1407 INP_WLOCK_ASSERT(inp); 1408 } else 1409 inp = NULL; 1410 1411 incl_opts = false; 1412 win = 0; 1413 if (tp != NULL) { 1414 if (!(flags & TH_RST)) { 1415 win = sbspace(&inp->inp_socket->so_rcv); 1416 if (win > TCP_MAXWIN << tp->rcv_scale) 1417 win = TCP_MAXWIN << tp->rcv_scale; 1418 } 1419 if ((tp->t_flags & TF_NOOPT) == 0) 1420 incl_opts = true; 1421 } 1422 if (m == NULL) { 1423 m = m_gethdr(M_NOWAIT, MT_DATA); 1424 if (m == NULL) 1425 return; 1426 m->m_data += max_linkhdr; 1427 #ifdef INET6 1428 if (isipv6) { 1429 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1430 sizeof(struct ip6_hdr)); 1431 ip6 = mtod(m, struct ip6_hdr *); 1432 nth = (struct tcphdr *)(ip6 + 1); 1433 } else 1434 #endif /* INET6 */ 1435 { 1436 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1437 ip = mtod(m, struct ip *); 1438 nth = (struct tcphdr *)(ip + 1); 1439 } 1440 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1441 flags = TH_ACK; 1442 } else if (!M_WRITABLE(m)) { 1443 struct mbuf *n; 1444 1445 /* Can't reuse 'm', allocate a new mbuf. */ 1446 n = m_gethdr(M_NOWAIT, MT_DATA); 1447 if (n == NULL) { 1448 m_freem(m); 1449 return; 1450 } 1451 1452 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1453 m_freem(m); 1454 m_freem(n); 1455 return; 1456 } 1457 1458 n->m_data += max_linkhdr; 1459 /* m_len is set later */ 1460 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1461 #ifdef INET6 1462 if (isipv6) { 1463 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1464 sizeof(struct ip6_hdr)); 1465 ip6 = mtod(n, struct ip6_hdr *); 1466 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1467 nth = (struct tcphdr *)(ip6 + 1); 1468 } else 1469 #endif /* INET6 */ 1470 { 1471 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1472 ip = mtod(n, struct ip *); 1473 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1474 nth = (struct tcphdr *)(ip + 1); 1475 } 1476 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1477 xchg(nth->th_dport, nth->th_sport, uint16_t); 1478 th = nth; 1479 m_freem(m); 1480 m = n; 1481 } else { 1482 /* 1483 * reuse the mbuf. 1484 * XXX MRT We inherit the FIB, which is lucky. 1485 */ 1486 m_freem(m->m_next); 1487 m->m_next = NULL; 1488 m->m_data = (caddr_t)ipgen; 1489 /* m_len is set later */ 1490 #ifdef INET6 1491 if (isipv6) { 1492 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1493 nth = (struct tcphdr *)(ip6 + 1); 1494 } else 1495 #endif /* INET6 */ 1496 { 1497 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1498 nth = (struct tcphdr *)(ip + 1); 1499 } 1500 if (th != nth) { 1501 /* 1502 * this is usually a case when an extension header 1503 * exists between the IPv6 header and the 1504 * TCP header. 1505 */ 1506 nth->th_sport = th->th_sport; 1507 nth->th_dport = th->th_dport; 1508 } 1509 xchg(nth->th_dport, nth->th_sport, uint16_t); 1510 #undef xchg 1511 } 1512 tlen = 0; 1513 #ifdef INET6 1514 if (isipv6) 1515 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1516 #endif 1517 #if defined(INET) && defined(INET6) 1518 else 1519 #endif 1520 #ifdef INET 1521 tlen = sizeof (struct tcpiphdr); 1522 #endif 1523 #ifdef INVARIANTS 1524 m->m_len = 0; 1525 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1526 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1527 m, tlen, (long)M_TRAILINGSPACE(m))); 1528 #endif 1529 m->m_len = tlen; 1530 to.to_flags = 0; 1531 if (incl_opts) { 1532 /* Make sure we have room. */ 1533 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1534 m->m_next = m_get(M_NOWAIT, MT_DATA); 1535 if (m->m_next) { 1536 optp = mtod(m->m_next, u_char *); 1537 optm = m->m_next; 1538 } else 1539 incl_opts = false; 1540 } else { 1541 optp = (u_char *) (nth + 1); 1542 optm = m; 1543 } 1544 } 1545 if (incl_opts) { 1546 /* Timestamps. */ 1547 if (tp->t_flags & TF_RCVD_TSTMP) { 1548 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1549 to.to_tsecr = tp->ts_recent; 1550 to.to_flags |= TOF_TS; 1551 } 1552 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1553 /* TCP-MD5 (RFC2385). */ 1554 if (tp->t_flags & TF_SIGNATURE) 1555 to.to_flags |= TOF_SIGNATURE; 1556 #endif 1557 /* Add the options. */ 1558 tlen += optlen = tcp_addoptions(&to, optp); 1559 1560 /* Update m_len in the correct mbuf. */ 1561 optm->m_len += optlen; 1562 } else 1563 optlen = 0; 1564 #ifdef INET6 1565 if (isipv6) { 1566 ip6->ip6_flow = 0; 1567 ip6->ip6_vfc = IPV6_VERSION; 1568 ip6->ip6_nxt = IPPROTO_TCP; 1569 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1570 } 1571 #endif 1572 #if defined(INET) && defined(INET6) 1573 else 1574 #endif 1575 #ifdef INET 1576 { 1577 ip->ip_len = htons(tlen); 1578 ip->ip_ttl = V_ip_defttl; 1579 if (V_path_mtu_discovery) 1580 ip->ip_off |= htons(IP_DF); 1581 } 1582 #endif 1583 m->m_pkthdr.len = tlen; 1584 m->m_pkthdr.rcvif = NULL; 1585 #ifdef MAC 1586 if (inp != NULL) { 1587 /* 1588 * Packet is associated with a socket, so allow the 1589 * label of the response to reflect the socket label. 1590 */ 1591 INP_WLOCK_ASSERT(inp); 1592 mac_inpcb_create_mbuf(inp, m); 1593 } else { 1594 /* 1595 * Packet is not associated with a socket, so possibly 1596 * update the label in place. 1597 */ 1598 mac_netinet_tcp_reply(m); 1599 } 1600 #endif 1601 nth->th_seq = htonl(seq); 1602 nth->th_ack = htonl(ack); 1603 nth->th_x2 = 0; 1604 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1605 nth->th_flags = flags; 1606 if (tp != NULL) 1607 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1608 else 1609 nth->th_win = htons((u_short)win); 1610 nth->th_urp = 0; 1611 1612 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1613 if (to.to_flags & TOF_SIGNATURE) { 1614 if (!TCPMD5_ENABLED() || 1615 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1616 m_freem(m); 1617 return; 1618 } 1619 } 1620 #endif 1621 1622 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1623 #ifdef INET6 1624 if (isipv6) { 1625 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1626 nth->th_sum = in6_cksum_pseudo(ip6, 1627 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1628 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1629 NULL, NULL); 1630 } 1631 #endif /* INET6 */ 1632 #if defined(INET6) && defined(INET) 1633 else 1634 #endif 1635 #ifdef INET 1636 { 1637 m->m_pkthdr.csum_flags = CSUM_TCP; 1638 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1639 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1640 } 1641 #endif /* INET */ 1642 #ifdef TCPDEBUG 1643 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1644 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1645 #endif 1646 TCP_PROBE3(debug__output, tp, th, m); 1647 if (flags & TH_RST) 1648 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1649 1650 #ifdef INET6 1651 if (isipv6) { 1652 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 1653 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1654 } 1655 #endif /* INET6 */ 1656 #if defined(INET) && defined(INET6) 1657 else 1658 #endif 1659 #ifdef INET 1660 { 1661 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 1662 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 1663 } 1664 #endif 1665 } 1666 1667 /* 1668 * Create a new TCP control block, making an 1669 * empty reassembly queue and hooking it to the argument 1670 * protocol control block. The `inp' parameter must have 1671 * come from the zone allocator set up in tcp_init(). 1672 */ 1673 struct tcpcb * 1674 tcp_newtcpcb(struct inpcb *inp) 1675 { 1676 struct tcpcb_mem *tm; 1677 struct tcpcb *tp; 1678 #ifdef INET6 1679 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1680 #endif /* INET6 */ 1681 1682 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1683 if (tm == NULL) 1684 return (NULL); 1685 tp = &tm->tcb; 1686 1687 /* Initialise cc_var struct for this tcpcb. */ 1688 tp->ccv = &tm->ccv; 1689 tp->ccv->type = IPPROTO_TCP; 1690 tp->ccv->ccvc.tcp = tp; 1691 rw_rlock(&tcp_function_lock); 1692 tp->t_fb = tcp_func_set_ptr; 1693 refcount_acquire(&tp->t_fb->tfb_refcnt); 1694 rw_runlock(&tcp_function_lock); 1695 /* 1696 * Use the current system default CC algorithm. 1697 */ 1698 CC_LIST_RLOCK(); 1699 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1700 CC_ALGO(tp) = CC_DEFAULT(); 1701 CC_LIST_RUNLOCK(); 1702 1703 if (CC_ALGO(tp)->cb_init != NULL) 1704 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1705 if (tp->t_fb->tfb_tcp_fb_fini) 1706 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1707 refcount_release(&tp->t_fb->tfb_refcnt); 1708 uma_zfree(V_tcpcb_zone, tm); 1709 return (NULL); 1710 } 1711 1712 #ifdef TCP_HHOOK 1713 tp->osd = &tm->osd; 1714 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1715 if (tp->t_fb->tfb_tcp_fb_fini) 1716 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1717 refcount_release(&tp->t_fb->tfb_refcnt); 1718 uma_zfree(V_tcpcb_zone, tm); 1719 return (NULL); 1720 } 1721 #endif 1722 1723 #ifdef VIMAGE 1724 tp->t_vnet = inp->inp_vnet; 1725 #endif 1726 tp->t_timers = &tm->tt; 1727 TAILQ_INIT(&tp->t_segq); 1728 tp->t_maxseg = 1729 #ifdef INET6 1730 isipv6 ? V_tcp_v6mssdflt : 1731 #endif /* INET6 */ 1732 V_tcp_mssdflt; 1733 1734 /* Set up our timeouts. */ 1735 callout_init(&tp->t_timers->tt_rexmt, 1); 1736 callout_init(&tp->t_timers->tt_persist, 1); 1737 callout_init(&tp->t_timers->tt_keep, 1); 1738 callout_init(&tp->t_timers->tt_2msl, 1); 1739 callout_init(&tp->t_timers->tt_delack, 1); 1740 1741 if (V_tcp_do_rfc1323) 1742 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1743 if (V_tcp_do_sack) 1744 tp->t_flags |= TF_SACK_PERMIT; 1745 TAILQ_INIT(&tp->snd_holes); 1746 /* 1747 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1748 * is called. 1749 */ 1750 in_pcbref(inp); /* Reference for tcpcb */ 1751 tp->t_inpcb = inp; 1752 1753 /* 1754 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1755 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1756 * reasonable initial retransmit time. 1757 */ 1758 tp->t_srtt = TCPTV_SRTTBASE; 1759 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1760 tp->t_rttmin = tcp_rexmit_min; 1761 tp->t_rxtcur = tcp_rexmit_initial; 1762 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1763 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1764 tp->t_rcvtime = ticks; 1765 /* 1766 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1767 * because the socket may be bound to an IPv6 wildcard address, 1768 * which may match an IPv4-mapped IPv6 address. 1769 */ 1770 inp->inp_ip_ttl = V_ip_defttl; 1771 inp->inp_ppcb = tp; 1772 #ifdef TCPPCAP 1773 /* 1774 * Init the TCP PCAP queues. 1775 */ 1776 tcp_pcap_tcpcb_init(tp); 1777 #endif 1778 #ifdef TCP_BLACKBOX 1779 /* Initialize the per-TCPCB log data. */ 1780 tcp_log_tcpcbinit(tp); 1781 #endif 1782 if (tp->t_fb->tfb_tcp_fb_init) { 1783 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1784 } 1785 #ifdef STATS 1786 if (V_tcp_perconn_stats_enable == 1) 1787 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 1788 #endif 1789 return (tp); /* XXX */ 1790 } 1791 1792 /* 1793 * Switch the congestion control algorithm back to NewReno for any active 1794 * control blocks using an algorithm which is about to go away. 1795 * This ensures the CC framework can allow the unload to proceed without leaving 1796 * any dangling pointers which would trigger a panic. 1797 * Returning non-zero would inform the CC framework that something went wrong 1798 * and it would be unsafe to allow the unload to proceed. However, there is no 1799 * way for this to occur with this implementation so we always return zero. 1800 */ 1801 int 1802 tcp_ccalgounload(struct cc_algo *unload_algo) 1803 { 1804 struct cc_algo *tmpalgo; 1805 struct inpcb *inp; 1806 struct tcpcb *tp; 1807 VNET_ITERATOR_DECL(vnet_iter); 1808 1809 /* 1810 * Check all active control blocks across all network stacks and change 1811 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1812 * requires cleanup code to be run, call it. 1813 */ 1814 VNET_LIST_RLOCK(); 1815 VNET_FOREACH(vnet_iter) { 1816 CURVNET_SET(vnet_iter); 1817 INP_INFO_WLOCK(&V_tcbinfo); 1818 /* 1819 * New connections already part way through being initialised 1820 * with the CC algo we're removing will not race with this code 1821 * because the INP_INFO_WLOCK is held during initialisation. We 1822 * therefore don't enter the loop below until the connection 1823 * list has stabilised. 1824 */ 1825 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 1826 INP_WLOCK(inp); 1827 /* Important to skip tcptw structs. */ 1828 if (!(inp->inp_flags & INP_TIMEWAIT) && 1829 (tp = intotcpcb(inp)) != NULL) { 1830 /* 1831 * By holding INP_WLOCK here, we are assured 1832 * that the connection is not currently 1833 * executing inside the CC module's functions 1834 * i.e. it is safe to make the switch back to 1835 * NewReno. 1836 */ 1837 if (CC_ALGO(tp) == unload_algo) { 1838 tmpalgo = CC_ALGO(tp); 1839 if (tmpalgo->cb_destroy != NULL) 1840 tmpalgo->cb_destroy(tp->ccv); 1841 CC_DATA(tp) = NULL; 1842 /* 1843 * NewReno may allocate memory on 1844 * demand for certain stateful 1845 * configuration as needed, but is 1846 * coded to never fail on memory 1847 * allocation failure so it is a safe 1848 * fallback. 1849 */ 1850 CC_ALGO(tp) = &newreno_cc_algo; 1851 } 1852 } 1853 INP_WUNLOCK(inp); 1854 } 1855 INP_INFO_WUNLOCK(&V_tcbinfo); 1856 CURVNET_RESTORE(); 1857 } 1858 VNET_LIST_RUNLOCK(); 1859 1860 return (0); 1861 } 1862 1863 /* 1864 * Drop a TCP connection, reporting 1865 * the specified error. If connection is synchronized, 1866 * then send a RST to peer. 1867 */ 1868 struct tcpcb * 1869 tcp_drop(struct tcpcb *tp, int errno) 1870 { 1871 struct socket *so = tp->t_inpcb->inp_socket; 1872 1873 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1874 INP_WLOCK_ASSERT(tp->t_inpcb); 1875 1876 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1877 tcp_state_change(tp, TCPS_CLOSED); 1878 (void) tp->t_fb->tfb_tcp_output(tp); 1879 TCPSTAT_INC(tcps_drops); 1880 } else 1881 TCPSTAT_INC(tcps_conndrops); 1882 if (errno == ETIMEDOUT && tp->t_softerror) 1883 errno = tp->t_softerror; 1884 so->so_error = errno; 1885 return (tcp_close(tp)); 1886 } 1887 1888 void 1889 tcp_discardcb(struct tcpcb *tp) 1890 { 1891 struct inpcb *inp = tp->t_inpcb; 1892 struct socket *so = inp->inp_socket; 1893 #ifdef INET6 1894 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1895 #endif /* INET6 */ 1896 int released __unused; 1897 1898 INP_WLOCK_ASSERT(inp); 1899 1900 /* 1901 * Make sure that all of our timers are stopped before we delete the 1902 * PCB. 1903 * 1904 * If stopping a timer fails, we schedule a discard function in same 1905 * callout, and the last discard function called will take care of 1906 * deleting the tcpcb. 1907 */ 1908 tp->t_timers->tt_draincnt = 0; 1909 tcp_timer_stop(tp, TT_REXMT); 1910 tcp_timer_stop(tp, TT_PERSIST); 1911 tcp_timer_stop(tp, TT_KEEP); 1912 tcp_timer_stop(tp, TT_2MSL); 1913 tcp_timer_stop(tp, TT_DELACK); 1914 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1915 /* 1916 * Call the stop-all function of the methods, 1917 * this function should call the tcp_timer_stop() 1918 * method with each of the function specific timeouts. 1919 * That stop will be called via the tfb_tcp_timer_stop() 1920 * which should use the async drain function of the 1921 * callout system (see tcp_var.h). 1922 */ 1923 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1924 } 1925 1926 /* 1927 * If we got enough samples through the srtt filter, 1928 * save the rtt and rttvar in the routing entry. 1929 * 'Enough' is arbitrarily defined as 4 rtt samples. 1930 * 4 samples is enough for the srtt filter to converge 1931 * to within enough % of the correct value; fewer samples 1932 * and we could save a bogus rtt. The danger is not high 1933 * as tcp quickly recovers from everything. 1934 * XXX: Works very well but needs some more statistics! 1935 */ 1936 if (tp->t_rttupdated >= 4) { 1937 struct hc_metrics_lite metrics; 1938 uint32_t ssthresh; 1939 1940 bzero(&metrics, sizeof(metrics)); 1941 /* 1942 * Update the ssthresh always when the conditions below 1943 * are satisfied. This gives us better new start value 1944 * for the congestion avoidance for new connections. 1945 * ssthresh is only set if packet loss occurred on a session. 1946 * 1947 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1948 * being torn down. Ideally this code would not use 'so'. 1949 */ 1950 ssthresh = tp->snd_ssthresh; 1951 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1952 /* 1953 * convert the limit from user data bytes to 1954 * packets then to packet data bytes. 1955 */ 1956 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1957 if (ssthresh < 2) 1958 ssthresh = 2; 1959 ssthresh *= (tp->t_maxseg + 1960 #ifdef INET6 1961 (isipv6 ? sizeof (struct ip6_hdr) + 1962 sizeof (struct tcphdr) : 1963 #endif 1964 sizeof (struct tcpiphdr) 1965 #ifdef INET6 1966 ) 1967 #endif 1968 ); 1969 } else 1970 ssthresh = 0; 1971 metrics.rmx_ssthresh = ssthresh; 1972 1973 metrics.rmx_rtt = tp->t_srtt; 1974 metrics.rmx_rttvar = tp->t_rttvar; 1975 metrics.rmx_cwnd = tp->snd_cwnd; 1976 metrics.rmx_sendpipe = 0; 1977 metrics.rmx_recvpipe = 0; 1978 1979 tcp_hc_update(&inp->inp_inc, &metrics); 1980 } 1981 1982 /* free the reassembly queue, if any */ 1983 tcp_reass_flush(tp); 1984 1985 #ifdef TCP_OFFLOAD 1986 /* Disconnect offload device, if any. */ 1987 if (tp->t_flags & TF_TOE) 1988 tcp_offload_detach(tp); 1989 #endif 1990 1991 tcp_free_sackholes(tp); 1992 1993 #ifdef TCPPCAP 1994 /* Free the TCP PCAP queues. */ 1995 tcp_pcap_drain(&(tp->t_inpkts)); 1996 tcp_pcap_drain(&(tp->t_outpkts)); 1997 #endif 1998 1999 /* Allow the CC algorithm to clean up after itself. */ 2000 if (CC_ALGO(tp)->cb_destroy != NULL) 2001 CC_ALGO(tp)->cb_destroy(tp->ccv); 2002 CC_DATA(tp) = NULL; 2003 2004 #ifdef TCP_HHOOK 2005 khelp_destroy_osd(tp->osd); 2006 #endif 2007 #ifdef STATS 2008 stats_blob_destroy(tp->t_stats); 2009 #endif 2010 2011 CC_ALGO(tp) = NULL; 2012 inp->inp_ppcb = NULL; 2013 if (tp->t_timers->tt_draincnt == 0) { 2014 /* We own the last reference on tcpcb, let's free it. */ 2015 #ifdef TCP_BLACKBOX 2016 tcp_log_tcpcbfini(tp); 2017 #endif 2018 TCPSTATES_DEC(tp->t_state); 2019 if (tp->t_fb->tfb_tcp_fb_fini) 2020 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2021 refcount_release(&tp->t_fb->tfb_refcnt); 2022 tp->t_inpcb = NULL; 2023 uma_zfree(V_tcpcb_zone, tp); 2024 released = in_pcbrele_wlocked(inp); 2025 KASSERT(!released, ("%s: inp %p should not have been released " 2026 "here", __func__, inp)); 2027 } 2028 } 2029 2030 void 2031 tcp_timer_discard(void *ptp) 2032 { 2033 struct inpcb *inp; 2034 struct tcpcb *tp; 2035 struct epoch_tracker et; 2036 2037 tp = (struct tcpcb *)ptp; 2038 CURVNET_SET(tp->t_vnet); 2039 NET_EPOCH_ENTER(et); 2040 inp = tp->t_inpcb; 2041 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 2042 __func__, tp)); 2043 INP_WLOCK(inp); 2044 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 2045 ("%s: tcpcb has to be stopped here", __func__)); 2046 tp->t_timers->tt_draincnt--; 2047 if (tp->t_timers->tt_draincnt == 0) { 2048 /* We own the last reference on this tcpcb, let's free it. */ 2049 #ifdef TCP_BLACKBOX 2050 tcp_log_tcpcbfini(tp); 2051 #endif 2052 TCPSTATES_DEC(tp->t_state); 2053 if (tp->t_fb->tfb_tcp_fb_fini) 2054 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2055 refcount_release(&tp->t_fb->tfb_refcnt); 2056 tp->t_inpcb = NULL; 2057 uma_zfree(V_tcpcb_zone, tp); 2058 if (in_pcbrele_wlocked(inp)) { 2059 NET_EPOCH_EXIT(et); 2060 CURVNET_RESTORE(); 2061 return; 2062 } 2063 } 2064 INP_WUNLOCK(inp); 2065 NET_EPOCH_EXIT(et); 2066 CURVNET_RESTORE(); 2067 } 2068 2069 /* 2070 * Attempt to close a TCP control block, marking it as dropped, and freeing 2071 * the socket if we hold the only reference. 2072 */ 2073 struct tcpcb * 2074 tcp_close(struct tcpcb *tp) 2075 { 2076 struct inpcb *inp = tp->t_inpcb; 2077 struct socket *so; 2078 2079 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2080 INP_WLOCK_ASSERT(inp); 2081 2082 #ifdef TCP_OFFLOAD 2083 if (tp->t_state == TCPS_LISTEN) 2084 tcp_offload_listen_stop(tp); 2085 #endif 2086 /* 2087 * This releases the TFO pending counter resource for TFO listen 2088 * sockets as well as passively-created TFO sockets that transition 2089 * from SYN_RECEIVED to CLOSED. 2090 */ 2091 if (tp->t_tfo_pending) { 2092 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2093 tp->t_tfo_pending = NULL; 2094 } 2095 in_pcbdrop(inp); 2096 TCPSTAT_INC(tcps_closed); 2097 if (tp->t_state != TCPS_CLOSED) 2098 tcp_state_change(tp, TCPS_CLOSED); 2099 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2100 so = inp->inp_socket; 2101 soisdisconnected(so); 2102 if (inp->inp_flags & INP_SOCKREF) { 2103 KASSERT(so->so_state & SS_PROTOREF, 2104 ("tcp_close: !SS_PROTOREF")); 2105 inp->inp_flags &= ~INP_SOCKREF; 2106 INP_WUNLOCK(inp); 2107 SOCK_LOCK(so); 2108 so->so_state &= ~SS_PROTOREF; 2109 sofree(so); 2110 return (NULL); 2111 } 2112 return (tp); 2113 } 2114 2115 void 2116 tcp_drain(void) 2117 { 2118 VNET_ITERATOR_DECL(vnet_iter); 2119 2120 if (!do_tcpdrain) 2121 return; 2122 2123 VNET_LIST_RLOCK_NOSLEEP(); 2124 VNET_FOREACH(vnet_iter) { 2125 CURVNET_SET(vnet_iter); 2126 struct inpcb *inpb; 2127 struct tcpcb *tcpb; 2128 2129 /* 2130 * Walk the tcpbs, if existing, and flush the reassembly queue, 2131 * if there is one... 2132 * XXX: The "Net/3" implementation doesn't imply that the TCP 2133 * reassembly queue should be flushed, but in a situation 2134 * where we're really low on mbufs, this is potentially 2135 * useful. 2136 */ 2137 INP_INFO_WLOCK(&V_tcbinfo); 2138 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2139 INP_WLOCK(inpb); 2140 if (inpb->inp_flags & INP_TIMEWAIT) { 2141 INP_WUNLOCK(inpb); 2142 continue; 2143 } 2144 if ((tcpb = intotcpcb(inpb)) != NULL) { 2145 tcp_reass_flush(tcpb); 2146 tcp_clean_sackreport(tcpb); 2147 #ifdef TCP_BLACKBOX 2148 tcp_log_drain(tcpb); 2149 #endif 2150 #ifdef TCPPCAP 2151 if (tcp_pcap_aggressive_free) { 2152 /* Free the TCP PCAP queues. */ 2153 tcp_pcap_drain(&(tcpb->t_inpkts)); 2154 tcp_pcap_drain(&(tcpb->t_outpkts)); 2155 } 2156 #endif 2157 } 2158 INP_WUNLOCK(inpb); 2159 } 2160 INP_INFO_WUNLOCK(&V_tcbinfo); 2161 CURVNET_RESTORE(); 2162 } 2163 VNET_LIST_RUNLOCK_NOSLEEP(); 2164 } 2165 2166 /* 2167 * Notify a tcp user of an asynchronous error; 2168 * store error as soft error, but wake up user 2169 * (for now, won't do anything until can select for soft error). 2170 * 2171 * Do not wake up user since there currently is no mechanism for 2172 * reporting soft errors (yet - a kqueue filter may be added). 2173 */ 2174 static struct inpcb * 2175 tcp_notify(struct inpcb *inp, int error) 2176 { 2177 struct tcpcb *tp; 2178 2179 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2180 INP_WLOCK_ASSERT(inp); 2181 2182 if ((inp->inp_flags & INP_TIMEWAIT) || 2183 (inp->inp_flags & INP_DROPPED)) 2184 return (inp); 2185 2186 tp = intotcpcb(inp); 2187 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2188 2189 /* 2190 * Ignore some errors if we are hooked up. 2191 * If connection hasn't completed, has retransmitted several times, 2192 * and receives a second error, give up now. This is better 2193 * than waiting a long time to establish a connection that 2194 * can never complete. 2195 */ 2196 if (tp->t_state == TCPS_ESTABLISHED && 2197 (error == EHOSTUNREACH || error == ENETUNREACH || 2198 error == EHOSTDOWN)) { 2199 if (inp->inp_route.ro_rt) { 2200 RTFREE(inp->inp_route.ro_rt); 2201 inp->inp_route.ro_rt = (struct rtentry *)NULL; 2202 } 2203 return (inp); 2204 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2205 tp->t_softerror) { 2206 tp = tcp_drop(tp, error); 2207 if (tp != NULL) 2208 return (inp); 2209 else 2210 return (NULL); 2211 } else { 2212 tp->t_softerror = error; 2213 return (inp); 2214 } 2215 #if 0 2216 wakeup( &so->so_timeo); 2217 sorwakeup(so); 2218 sowwakeup(so); 2219 #endif 2220 } 2221 2222 static int 2223 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2224 { 2225 struct epoch_tracker et; 2226 struct inpcb *inp; 2227 struct xinpgen xig; 2228 int error; 2229 2230 if (req->newptr != NULL) 2231 return (EPERM); 2232 2233 if (req->oldptr == NULL) { 2234 int n; 2235 2236 n = V_tcbinfo.ipi_count + 2237 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2238 n += imax(n / 8, 10); 2239 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2240 return (0); 2241 } 2242 2243 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2244 return (error); 2245 2246 bzero(&xig, sizeof(xig)); 2247 xig.xig_len = sizeof xig; 2248 xig.xig_count = V_tcbinfo.ipi_count + 2249 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2250 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2251 xig.xig_sogen = so_gencnt; 2252 error = SYSCTL_OUT(req, &xig, sizeof xig); 2253 if (error) 2254 return (error); 2255 2256 error = syncache_pcblist(req); 2257 if (error) 2258 return (error); 2259 2260 NET_EPOCH_ENTER(et); 2261 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2262 inp != NULL; 2263 inp = CK_LIST_NEXT(inp, inp_list)) { 2264 INP_RLOCK(inp); 2265 if (inp->inp_gencnt <= xig.xig_gen) { 2266 /* 2267 * XXX: This use of cr_cansee(), introduced with 2268 * TCP state changes, is not quite right, but for 2269 * now, better than nothing. 2270 */ 2271 if (inp->inp_flags & INP_TIMEWAIT) { 2272 if (intotw(inp) != NULL) 2273 error = cr_cansee(req->td->td_ucred, 2274 intotw(inp)->tw_cred); 2275 else 2276 error = EINVAL; /* Skip this inp. */ 2277 } else 2278 error = cr_canseeinpcb(req->td->td_ucred, inp); 2279 if (error == 0) { 2280 struct xtcpcb xt; 2281 2282 tcp_inptoxtp(inp, &xt); 2283 INP_RUNLOCK(inp); 2284 error = SYSCTL_OUT(req, &xt, sizeof xt); 2285 if (error) 2286 break; 2287 else 2288 continue; 2289 } 2290 } 2291 INP_RUNLOCK(inp); 2292 } 2293 NET_EPOCH_EXIT(et); 2294 2295 if (!error) { 2296 /* 2297 * Give the user an updated idea of our state. 2298 * If the generation differs from what we told 2299 * her before, she knows that something happened 2300 * while we were processing this request, and it 2301 * might be necessary to retry. 2302 */ 2303 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2304 xig.xig_sogen = so_gencnt; 2305 xig.xig_count = V_tcbinfo.ipi_count + 2306 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2307 error = SYSCTL_OUT(req, &xig, sizeof xig); 2308 } 2309 2310 return (error); 2311 } 2312 2313 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2314 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2315 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 2316 2317 #ifdef INET 2318 static int 2319 tcp_getcred(SYSCTL_HANDLER_ARGS) 2320 { 2321 struct xucred xuc; 2322 struct sockaddr_in addrs[2]; 2323 struct epoch_tracker et; 2324 struct inpcb *inp; 2325 int error; 2326 2327 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2328 if (error) 2329 return (error); 2330 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2331 if (error) 2332 return (error); 2333 NET_EPOCH_ENTER(et); 2334 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2335 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2336 NET_EPOCH_EXIT(et); 2337 if (inp != NULL) { 2338 if (inp->inp_socket == NULL) 2339 error = ENOENT; 2340 if (error == 0) 2341 error = cr_canseeinpcb(req->td->td_ucred, inp); 2342 if (error == 0) 2343 cru2x(inp->inp_cred, &xuc); 2344 INP_RUNLOCK(inp); 2345 } else 2346 error = ENOENT; 2347 if (error == 0) 2348 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2349 return (error); 2350 } 2351 2352 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2353 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2354 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 2355 #endif /* INET */ 2356 2357 #ifdef INET6 2358 static int 2359 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2360 { 2361 struct epoch_tracker et; 2362 struct xucred xuc; 2363 struct sockaddr_in6 addrs[2]; 2364 struct inpcb *inp; 2365 int error; 2366 #ifdef INET 2367 int mapped = 0; 2368 #endif 2369 2370 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2371 if (error) 2372 return (error); 2373 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2374 if (error) 2375 return (error); 2376 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2377 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2378 return (error); 2379 } 2380 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2381 #ifdef INET 2382 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2383 mapped = 1; 2384 else 2385 #endif 2386 return (EINVAL); 2387 } 2388 2389 NET_EPOCH_ENTER(et); 2390 #ifdef INET 2391 if (mapped == 1) 2392 inp = in_pcblookup(&V_tcbinfo, 2393 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2394 addrs[1].sin6_port, 2395 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2396 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2397 else 2398 #endif 2399 inp = in6_pcblookup(&V_tcbinfo, 2400 &addrs[1].sin6_addr, addrs[1].sin6_port, 2401 &addrs[0].sin6_addr, addrs[0].sin6_port, 2402 INPLOOKUP_RLOCKPCB, NULL); 2403 NET_EPOCH_EXIT(et); 2404 if (inp != NULL) { 2405 if (inp->inp_socket == NULL) 2406 error = ENOENT; 2407 if (error == 0) 2408 error = cr_canseeinpcb(req->td->td_ucred, inp); 2409 if (error == 0) 2410 cru2x(inp->inp_cred, &xuc); 2411 INP_RUNLOCK(inp); 2412 } else 2413 error = ENOENT; 2414 if (error == 0) 2415 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2416 return (error); 2417 } 2418 2419 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2420 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 2421 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 2422 #endif /* INET6 */ 2423 2424 2425 #ifdef INET 2426 void 2427 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2428 { 2429 struct ip *ip = vip; 2430 struct tcphdr *th; 2431 struct in_addr faddr; 2432 struct inpcb *inp; 2433 struct tcpcb *tp; 2434 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2435 struct icmp *icp; 2436 struct in_conninfo inc; 2437 tcp_seq icmp_tcp_seq; 2438 int mtu; 2439 2440 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2441 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2442 return; 2443 2444 if (cmd == PRC_MSGSIZE) 2445 notify = tcp_mtudisc_notify; 2446 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2447 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2448 cmd == PRC_TIMXCEED_INTRANS) && ip) 2449 notify = tcp_drop_syn_sent; 2450 2451 /* 2452 * Hostdead is ugly because it goes linearly through all PCBs. 2453 * XXX: We never get this from ICMP, otherwise it makes an 2454 * excellent DoS attack on machines with many connections. 2455 */ 2456 else if (cmd == PRC_HOSTDEAD) 2457 ip = NULL; 2458 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2459 return; 2460 2461 if (ip == NULL) { 2462 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2463 return; 2464 } 2465 2466 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2467 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2468 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2469 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2470 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2471 /* signal EHOSTDOWN, as it flushes the cached route */ 2472 inp = (*notify)(inp, EHOSTDOWN); 2473 goto out; 2474 } 2475 icmp_tcp_seq = th->th_seq; 2476 if (inp != NULL) { 2477 if (!(inp->inp_flags & INP_TIMEWAIT) && 2478 !(inp->inp_flags & INP_DROPPED) && 2479 !(inp->inp_socket == NULL)) { 2480 tp = intotcpcb(inp); 2481 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2482 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2483 if (cmd == PRC_MSGSIZE) { 2484 /* 2485 * MTU discovery: 2486 * If we got a needfrag set the MTU 2487 * in the route to the suggested new 2488 * value (if given) and then notify. 2489 */ 2490 mtu = ntohs(icp->icmp_nextmtu); 2491 /* 2492 * If no alternative MTU was 2493 * proposed, try the next smaller 2494 * one. 2495 */ 2496 if (!mtu) 2497 mtu = ip_next_mtu( 2498 ntohs(ip->ip_len), 1); 2499 if (mtu < V_tcp_minmss + 2500 sizeof(struct tcpiphdr)) 2501 mtu = V_tcp_minmss + 2502 sizeof(struct tcpiphdr); 2503 /* 2504 * Only process the offered MTU if it 2505 * is smaller than the current one. 2506 */ 2507 if (mtu < tp->t_maxseg + 2508 sizeof(struct tcpiphdr)) { 2509 bzero(&inc, sizeof(inc)); 2510 inc.inc_faddr = faddr; 2511 inc.inc_fibnum = 2512 inp->inp_inc.inc_fibnum; 2513 tcp_hc_updatemtu(&inc, mtu); 2514 tcp_mtudisc(inp, mtu); 2515 } 2516 } else 2517 inp = (*notify)(inp, 2518 inetctlerrmap[cmd]); 2519 } 2520 } 2521 } else { 2522 bzero(&inc, sizeof(inc)); 2523 inc.inc_fport = th->th_dport; 2524 inc.inc_lport = th->th_sport; 2525 inc.inc_faddr = faddr; 2526 inc.inc_laddr = ip->ip_src; 2527 syncache_unreach(&inc, icmp_tcp_seq); 2528 } 2529 out: 2530 if (inp != NULL) 2531 INP_WUNLOCK(inp); 2532 } 2533 #endif /* INET */ 2534 2535 #ifdef INET6 2536 void 2537 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2538 { 2539 struct in6_addr *dst; 2540 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2541 struct ip6_hdr *ip6; 2542 struct mbuf *m; 2543 struct inpcb *inp; 2544 struct tcpcb *tp; 2545 struct icmp6_hdr *icmp6; 2546 struct ip6ctlparam *ip6cp = NULL; 2547 const struct sockaddr_in6 *sa6_src = NULL; 2548 struct in_conninfo inc; 2549 struct tcp_ports { 2550 uint16_t th_sport; 2551 uint16_t th_dport; 2552 } t_ports; 2553 tcp_seq icmp_tcp_seq; 2554 unsigned int mtu; 2555 unsigned int off; 2556 2557 if (sa->sa_family != AF_INET6 || 2558 sa->sa_len != sizeof(struct sockaddr_in6)) 2559 return; 2560 2561 /* if the parameter is from icmp6, decode it. */ 2562 if (d != NULL) { 2563 ip6cp = (struct ip6ctlparam *)d; 2564 icmp6 = ip6cp->ip6c_icmp6; 2565 m = ip6cp->ip6c_m; 2566 ip6 = ip6cp->ip6c_ip6; 2567 off = ip6cp->ip6c_off; 2568 sa6_src = ip6cp->ip6c_src; 2569 dst = ip6cp->ip6c_finaldst; 2570 } else { 2571 m = NULL; 2572 ip6 = NULL; 2573 off = 0; /* fool gcc */ 2574 sa6_src = &sa6_any; 2575 dst = NULL; 2576 } 2577 2578 if (cmd == PRC_MSGSIZE) 2579 notify = tcp_mtudisc_notify; 2580 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2581 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2582 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2583 notify = tcp_drop_syn_sent; 2584 2585 /* 2586 * Hostdead is ugly because it goes linearly through all PCBs. 2587 * XXX: We never get this from ICMP, otherwise it makes an 2588 * excellent DoS attack on machines with many connections. 2589 */ 2590 else if (cmd == PRC_HOSTDEAD) 2591 ip6 = NULL; 2592 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2593 return; 2594 2595 if (ip6 == NULL) { 2596 in6_pcbnotify(&V_tcbinfo, sa, 0, 2597 (const struct sockaddr *)sa6_src, 2598 0, cmd, NULL, notify); 2599 return; 2600 } 2601 2602 /* Check if we can safely get the ports from the tcp hdr */ 2603 if (m == NULL || 2604 (m->m_pkthdr.len < 2605 (int32_t) (off + sizeof(struct tcp_ports)))) { 2606 return; 2607 } 2608 bzero(&t_ports, sizeof(struct tcp_ports)); 2609 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2610 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2611 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2612 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2613 /* signal EHOSTDOWN, as it flushes the cached route */ 2614 inp = (*notify)(inp, EHOSTDOWN); 2615 goto out; 2616 } 2617 off += sizeof(struct tcp_ports); 2618 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2619 goto out; 2620 } 2621 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2622 if (inp != NULL) { 2623 if (!(inp->inp_flags & INP_TIMEWAIT) && 2624 !(inp->inp_flags & INP_DROPPED) && 2625 !(inp->inp_socket == NULL)) { 2626 tp = intotcpcb(inp); 2627 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2628 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2629 if (cmd == PRC_MSGSIZE) { 2630 /* 2631 * MTU discovery: 2632 * If we got a needfrag set the MTU 2633 * in the route to the suggested new 2634 * value (if given) and then notify. 2635 */ 2636 mtu = ntohl(icmp6->icmp6_mtu); 2637 /* 2638 * If no alternative MTU was 2639 * proposed, or the proposed 2640 * MTU was too small, set to 2641 * the min. 2642 */ 2643 if (mtu < IPV6_MMTU) 2644 mtu = IPV6_MMTU - 8; 2645 bzero(&inc, sizeof(inc)); 2646 inc.inc_fibnum = M_GETFIB(m); 2647 inc.inc_flags |= INC_ISIPV6; 2648 inc.inc6_faddr = *dst; 2649 if (in6_setscope(&inc.inc6_faddr, 2650 m->m_pkthdr.rcvif, NULL)) 2651 goto out; 2652 /* 2653 * Only process the offered MTU if it 2654 * is smaller than the current one. 2655 */ 2656 if (mtu < tp->t_maxseg + 2657 sizeof (struct tcphdr) + 2658 sizeof (struct ip6_hdr)) { 2659 tcp_hc_updatemtu(&inc, mtu); 2660 tcp_mtudisc(inp, mtu); 2661 ICMP6STAT_INC(icp6s_pmtuchg); 2662 } 2663 } else 2664 inp = (*notify)(inp, 2665 inet6ctlerrmap[cmd]); 2666 } 2667 } 2668 } else { 2669 bzero(&inc, sizeof(inc)); 2670 inc.inc_fibnum = M_GETFIB(m); 2671 inc.inc_flags |= INC_ISIPV6; 2672 inc.inc_fport = t_ports.th_dport; 2673 inc.inc_lport = t_ports.th_sport; 2674 inc.inc6_faddr = *dst; 2675 inc.inc6_laddr = ip6->ip6_src; 2676 syncache_unreach(&inc, icmp_tcp_seq); 2677 } 2678 out: 2679 if (inp != NULL) 2680 INP_WUNLOCK(inp); 2681 } 2682 #endif /* INET6 */ 2683 2684 static uint32_t 2685 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 2686 { 2687 SIPHASH_CTX ctx; 2688 uint32_t hash[2]; 2689 2690 KASSERT(len >= SIPHASH_KEY_LENGTH, 2691 ("%s: keylen %u too short ", __func__, len)); 2692 SipHash24_Init(&ctx); 2693 SipHash_SetKey(&ctx, (uint8_t *)key); 2694 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 2695 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 2696 switch (inc->inc_flags & INC_ISIPV6) { 2697 #ifdef INET 2698 case 0: 2699 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 2700 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 2701 break; 2702 #endif 2703 #ifdef INET6 2704 case INC_ISIPV6: 2705 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 2706 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 2707 break; 2708 #endif 2709 } 2710 SipHash_Final((uint8_t *)hash, &ctx); 2711 2712 return (hash[0] ^ hash[1]); 2713 } 2714 2715 uint32_t 2716 tcp_new_ts_offset(struct in_conninfo *inc) 2717 { 2718 struct in_conninfo inc_store, *local_inc; 2719 2720 if (!V_tcp_ts_offset_per_conn) { 2721 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 2722 inc_store.inc_lport = 0; 2723 inc_store.inc_fport = 0; 2724 local_inc = &inc_store; 2725 } else { 2726 local_inc = inc; 2727 } 2728 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 2729 sizeof(V_ts_offset_secret))); 2730 } 2731 2732 /* 2733 * Following is where TCP initial sequence number generation occurs. 2734 * 2735 * There are two places where we must use initial sequence numbers: 2736 * 1. In SYN-ACK packets. 2737 * 2. In SYN packets. 2738 * 2739 * All ISNs for SYN-ACK packets are generated by the syncache. See 2740 * tcp_syncache.c for details. 2741 * 2742 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2743 * depends on this property. In addition, these ISNs should be 2744 * unguessable so as to prevent connection hijacking. To satisfy 2745 * the requirements of this situation, the algorithm outlined in 2746 * RFC 1948 is used, with only small modifications. 2747 * 2748 * Implementation details: 2749 * 2750 * Time is based off the system timer, and is corrected so that it 2751 * increases by one megabyte per second. This allows for proper 2752 * recycling on high speed LANs while still leaving over an hour 2753 * before rollover. 2754 * 2755 * As reading the *exact* system time is too expensive to be done 2756 * whenever setting up a TCP connection, we increment the time 2757 * offset in two ways. First, a small random positive increment 2758 * is added to isn_offset for each connection that is set up. 2759 * Second, the function tcp_isn_tick fires once per clock tick 2760 * and increments isn_offset as necessary so that sequence numbers 2761 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2762 * random positive increments serve only to ensure that the same 2763 * exact sequence number is never sent out twice (as could otherwise 2764 * happen when a port is recycled in less than the system tick 2765 * interval.) 2766 * 2767 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2768 * between seeding of isn_secret. This is normally set to zero, 2769 * as reseeding should not be necessary. 2770 * 2771 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2772 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 2773 * general, this means holding an exclusive (write) lock. 2774 */ 2775 2776 #define ISN_BYTES_PER_SECOND 1048576 2777 #define ISN_STATIC_INCREMENT 4096 2778 #define ISN_RANDOM_INCREMENT (4096 - 1) 2779 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 2780 2781 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 2782 VNET_DEFINE_STATIC(int, isn_last); 2783 VNET_DEFINE_STATIC(int, isn_last_reseed); 2784 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 2785 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 2786 2787 #define V_isn_secret VNET(isn_secret) 2788 #define V_isn_last VNET(isn_last) 2789 #define V_isn_last_reseed VNET(isn_last_reseed) 2790 #define V_isn_offset VNET(isn_offset) 2791 #define V_isn_offset_old VNET(isn_offset_old) 2792 2793 tcp_seq 2794 tcp_new_isn(struct in_conninfo *inc) 2795 { 2796 tcp_seq new_isn; 2797 u_int32_t projected_offset; 2798 2799 ISN_LOCK(); 2800 /* Seed if this is the first use, reseed if requested. */ 2801 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2802 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2803 < (u_int)ticks))) { 2804 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 2805 V_isn_last_reseed = ticks; 2806 } 2807 2808 /* Compute the hash and return the ISN. */ 2809 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 2810 sizeof(V_isn_secret)); 2811 V_isn_offset += ISN_STATIC_INCREMENT + 2812 (arc4random() & ISN_RANDOM_INCREMENT); 2813 if (ticks != V_isn_last) { 2814 projected_offset = V_isn_offset_old + 2815 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2816 if (SEQ_GT(projected_offset, V_isn_offset)) 2817 V_isn_offset = projected_offset; 2818 V_isn_offset_old = V_isn_offset; 2819 V_isn_last = ticks; 2820 } 2821 new_isn += V_isn_offset; 2822 ISN_UNLOCK(); 2823 return (new_isn); 2824 } 2825 2826 /* 2827 * When a specific ICMP unreachable message is received and the 2828 * connection state is SYN-SENT, drop the connection. This behavior 2829 * is controlled by the icmp_may_rst sysctl. 2830 */ 2831 struct inpcb * 2832 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2833 { 2834 struct tcpcb *tp; 2835 2836 NET_EPOCH_ASSERT(); 2837 INP_WLOCK_ASSERT(inp); 2838 2839 if ((inp->inp_flags & INP_TIMEWAIT) || 2840 (inp->inp_flags & INP_DROPPED)) 2841 return (inp); 2842 2843 tp = intotcpcb(inp); 2844 if (tp->t_state != TCPS_SYN_SENT) 2845 return (inp); 2846 2847 if (IS_FASTOPEN(tp->t_flags)) 2848 tcp_fastopen_disable_path(tp); 2849 2850 tp = tcp_drop(tp, errno); 2851 if (tp != NULL) 2852 return (inp); 2853 else 2854 return (NULL); 2855 } 2856 2857 /* 2858 * When `need fragmentation' ICMP is received, update our idea of the MSS 2859 * based on the new value. Also nudge TCP to send something, since we 2860 * know the packet we just sent was dropped. 2861 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2862 */ 2863 static struct inpcb * 2864 tcp_mtudisc_notify(struct inpcb *inp, int error) 2865 { 2866 2867 tcp_mtudisc(inp, -1); 2868 return (inp); 2869 } 2870 2871 static void 2872 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2873 { 2874 struct tcpcb *tp; 2875 struct socket *so; 2876 2877 INP_WLOCK_ASSERT(inp); 2878 if ((inp->inp_flags & INP_TIMEWAIT) || 2879 (inp->inp_flags & INP_DROPPED)) 2880 return; 2881 2882 tp = intotcpcb(inp); 2883 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2884 2885 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2886 2887 so = inp->inp_socket; 2888 SOCKBUF_LOCK(&so->so_snd); 2889 /* If the mss is larger than the socket buffer, decrease the mss. */ 2890 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2891 tp->t_maxseg = so->so_snd.sb_hiwat; 2892 SOCKBUF_UNLOCK(&so->so_snd); 2893 2894 TCPSTAT_INC(tcps_mturesent); 2895 tp->t_rtttime = 0; 2896 tp->snd_nxt = tp->snd_una; 2897 tcp_free_sackholes(tp); 2898 tp->snd_recover = tp->snd_max; 2899 if (tp->t_flags & TF_SACK_PERMIT) 2900 EXIT_FASTRECOVERY(tp->t_flags); 2901 tp->t_fb->tfb_tcp_output(tp); 2902 } 2903 2904 #ifdef INET 2905 /* 2906 * Look-up the routing entry to the peer of this inpcb. If no route 2907 * is found and it cannot be allocated, then return 0. This routine 2908 * is called by TCP routines that access the rmx structure and by 2909 * tcp_mss_update to get the peer/interface MTU. 2910 */ 2911 uint32_t 2912 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2913 { 2914 struct nhop4_extended nh4; 2915 struct ifnet *ifp; 2916 uint32_t maxmtu = 0; 2917 2918 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2919 2920 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2921 2922 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2923 NHR_REF, 0, &nh4) != 0) 2924 return (0); 2925 2926 ifp = nh4.nh_ifp; 2927 maxmtu = nh4.nh_mtu; 2928 2929 /* Report additional interface capabilities. */ 2930 if (cap != NULL) { 2931 if (ifp->if_capenable & IFCAP_TSO4 && 2932 ifp->if_hwassist & CSUM_TSO) { 2933 cap->ifcap |= CSUM_TSO; 2934 cap->tsomax = ifp->if_hw_tsomax; 2935 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2936 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2937 } 2938 } 2939 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2940 } 2941 return (maxmtu); 2942 } 2943 #endif /* INET */ 2944 2945 #ifdef INET6 2946 uint32_t 2947 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2948 { 2949 struct nhop6_extended nh6; 2950 struct in6_addr dst6; 2951 uint32_t scopeid; 2952 struct ifnet *ifp; 2953 uint32_t maxmtu = 0; 2954 2955 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2956 2957 if (inc->inc_flags & INC_IPV6MINMTU) 2958 return (IPV6_MMTU); 2959 2960 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2961 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2962 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2963 0, &nh6) != 0) 2964 return (0); 2965 2966 ifp = nh6.nh_ifp; 2967 maxmtu = nh6.nh_mtu; 2968 2969 /* Report additional interface capabilities. */ 2970 if (cap != NULL) { 2971 if (ifp->if_capenable & IFCAP_TSO6 && 2972 ifp->if_hwassist & CSUM_TSO) { 2973 cap->ifcap |= CSUM_TSO; 2974 cap->tsomax = ifp->if_hw_tsomax; 2975 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2976 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2977 } 2978 } 2979 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2980 } 2981 2982 return (maxmtu); 2983 } 2984 #endif /* INET6 */ 2985 2986 /* 2987 * Calculate effective SMSS per RFC5681 definition for a given TCP 2988 * connection at its current state, taking into account SACK and etc. 2989 */ 2990 u_int 2991 tcp_maxseg(const struct tcpcb *tp) 2992 { 2993 u_int optlen; 2994 2995 if (tp->t_flags & TF_NOOPT) 2996 return (tp->t_maxseg); 2997 2998 /* 2999 * Here we have a simplified code from tcp_addoptions(), 3000 * without a proper loop, and having most of paddings hardcoded. 3001 * We might make mistakes with padding here in some edge cases, 3002 * but this is harmless, since result of tcp_maxseg() is used 3003 * only in cwnd and ssthresh estimations. 3004 */ 3005 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3006 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3007 if (tp->t_flags & TF_RCVD_TSTMP) 3008 optlen = TCPOLEN_TSTAMP_APPA; 3009 else 3010 optlen = 0; 3011 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3012 if (tp->t_flags & TF_SIGNATURE) 3013 optlen += PAD(TCPOLEN_SIGNATURE); 3014 #endif 3015 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3016 optlen += TCPOLEN_SACKHDR; 3017 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3018 optlen = PAD(optlen); 3019 } 3020 } else { 3021 if (tp->t_flags & TF_REQ_TSTMP) 3022 optlen = TCPOLEN_TSTAMP_APPA; 3023 else 3024 optlen = PAD(TCPOLEN_MAXSEG); 3025 if (tp->t_flags & TF_REQ_SCALE) 3026 optlen += PAD(TCPOLEN_WINDOW); 3027 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3028 if (tp->t_flags & TF_SIGNATURE) 3029 optlen += PAD(TCPOLEN_SIGNATURE); 3030 #endif 3031 if (tp->t_flags & TF_SACK_PERMIT) 3032 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3033 } 3034 #undef PAD 3035 optlen = min(optlen, TCP_MAXOLEN); 3036 return (tp->t_maxseg - optlen); 3037 } 3038 3039 static int 3040 sysctl_drop(SYSCTL_HANDLER_ARGS) 3041 { 3042 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3043 struct sockaddr_storage addrs[2]; 3044 struct inpcb *inp; 3045 struct tcpcb *tp; 3046 struct tcptw *tw; 3047 struct sockaddr_in *fin, *lin; 3048 struct epoch_tracker et; 3049 #ifdef INET6 3050 struct sockaddr_in6 *fin6, *lin6; 3051 #endif 3052 int error; 3053 3054 inp = NULL; 3055 fin = lin = NULL; 3056 #ifdef INET6 3057 fin6 = lin6 = NULL; 3058 #endif 3059 error = 0; 3060 3061 if (req->oldptr != NULL || req->oldlen != 0) 3062 return (EINVAL); 3063 if (req->newptr == NULL) 3064 return (EPERM); 3065 if (req->newlen < sizeof(addrs)) 3066 return (ENOMEM); 3067 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3068 if (error) 3069 return (error); 3070 3071 switch (addrs[0].ss_family) { 3072 #ifdef INET6 3073 case AF_INET6: 3074 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3075 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3076 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3077 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3078 return (EINVAL); 3079 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3080 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3081 return (EINVAL); 3082 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3083 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3084 fin = (struct sockaddr_in *)&addrs[0]; 3085 lin = (struct sockaddr_in *)&addrs[1]; 3086 break; 3087 } 3088 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3089 if (error) 3090 return (error); 3091 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3092 if (error) 3093 return (error); 3094 break; 3095 #endif 3096 #ifdef INET 3097 case AF_INET: 3098 fin = (struct sockaddr_in *)&addrs[0]; 3099 lin = (struct sockaddr_in *)&addrs[1]; 3100 if (fin->sin_len != sizeof(struct sockaddr_in) || 3101 lin->sin_len != sizeof(struct sockaddr_in)) 3102 return (EINVAL); 3103 break; 3104 #endif 3105 default: 3106 return (EINVAL); 3107 } 3108 NET_EPOCH_ENTER(et); 3109 switch (addrs[0].ss_family) { 3110 #ifdef INET6 3111 case AF_INET6: 3112 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3113 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3114 INPLOOKUP_WLOCKPCB, NULL); 3115 break; 3116 #endif 3117 #ifdef INET 3118 case AF_INET: 3119 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3120 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3121 break; 3122 #endif 3123 } 3124 if (inp != NULL) { 3125 if (inp->inp_flags & INP_TIMEWAIT) { 3126 /* 3127 * XXXRW: There currently exists a state where an 3128 * inpcb is present, but its timewait state has been 3129 * discarded. For now, don't allow dropping of this 3130 * type of inpcb. 3131 */ 3132 tw = intotw(inp); 3133 if (tw != NULL) 3134 tcp_twclose(tw, 0); 3135 else 3136 INP_WUNLOCK(inp); 3137 } else if (!(inp->inp_flags & INP_DROPPED) && 3138 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3139 tp = intotcpcb(inp); 3140 tp = tcp_drop(tp, ECONNABORTED); 3141 if (tp != NULL) 3142 INP_WUNLOCK(inp); 3143 } else 3144 INP_WUNLOCK(inp); 3145 } else 3146 error = ESRCH; 3147 NET_EPOCH_EXIT(et); 3148 return (error); 3149 } 3150 3151 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3152 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3153 0, sysctl_drop, "", "Drop TCP connection"); 3154 3155 #ifdef KERN_TLS 3156 static int 3157 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3158 { 3159 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3160 struct sockaddr_storage addrs[2]; 3161 struct inpcb *inp; 3162 struct sockaddr_in *fin, *lin; 3163 struct epoch_tracker et; 3164 #ifdef INET6 3165 struct sockaddr_in6 *fin6, *lin6; 3166 #endif 3167 int error; 3168 3169 inp = NULL; 3170 fin = lin = NULL; 3171 #ifdef INET6 3172 fin6 = lin6 = NULL; 3173 #endif 3174 error = 0; 3175 3176 if (req->oldptr != NULL || req->oldlen != 0) 3177 return (EINVAL); 3178 if (req->newptr == NULL) 3179 return (EPERM); 3180 if (req->newlen < sizeof(addrs)) 3181 return (ENOMEM); 3182 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3183 if (error) 3184 return (error); 3185 3186 switch (addrs[0].ss_family) { 3187 #ifdef INET6 3188 case AF_INET6: 3189 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3190 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3191 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3192 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3193 return (EINVAL); 3194 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3195 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3196 return (EINVAL); 3197 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3198 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3199 fin = (struct sockaddr_in *)&addrs[0]; 3200 lin = (struct sockaddr_in *)&addrs[1]; 3201 break; 3202 } 3203 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3204 if (error) 3205 return (error); 3206 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3207 if (error) 3208 return (error); 3209 break; 3210 #endif 3211 #ifdef INET 3212 case AF_INET: 3213 fin = (struct sockaddr_in *)&addrs[0]; 3214 lin = (struct sockaddr_in *)&addrs[1]; 3215 if (fin->sin_len != sizeof(struct sockaddr_in) || 3216 lin->sin_len != sizeof(struct sockaddr_in)) 3217 return (EINVAL); 3218 break; 3219 #endif 3220 default: 3221 return (EINVAL); 3222 } 3223 NET_EPOCH_ENTER(et); 3224 switch (addrs[0].ss_family) { 3225 #ifdef INET6 3226 case AF_INET6: 3227 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3228 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3229 INPLOOKUP_WLOCKPCB, NULL); 3230 break; 3231 #endif 3232 #ifdef INET 3233 case AF_INET: 3234 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3235 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3236 break; 3237 #endif 3238 } 3239 NET_EPOCH_EXIT(et); 3240 if (inp != NULL) { 3241 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3242 inp->inp_socket == NULL) { 3243 error = ECONNRESET; 3244 INP_WUNLOCK(inp); 3245 } else { 3246 struct socket *so; 3247 3248 so = inp->inp_socket; 3249 soref(so); 3250 error = ktls_set_tx_mode(so, 3251 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3252 INP_WUNLOCK(inp); 3253 SOCK_LOCK(so); 3254 sorele(so); 3255 } 3256 } else 3257 error = ESRCH; 3258 return (error); 3259 } 3260 3261 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3262 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3263 0, sysctl_switch_tls, "", "Switch TCP connection to SW TLS"); 3264 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3265 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 3266 1, sysctl_switch_tls, "", "Switch TCP connection to ifnet TLS"); 3267 #endif 3268 3269 /* 3270 * Generate a standardized TCP log line for use throughout the 3271 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3272 * allow use in the interrupt context. 3273 * 3274 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3275 * NB: The function may return NULL if memory allocation failed. 3276 * 3277 * Due to header inclusion and ordering limitations the struct ip 3278 * and ip6_hdr pointers have to be passed as void pointers. 3279 */ 3280 char * 3281 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3282 const void *ip6hdr) 3283 { 3284 3285 /* Is logging enabled? */ 3286 if (tcp_log_in_vain == 0) 3287 return (NULL); 3288 3289 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3290 } 3291 3292 char * 3293 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3294 const void *ip6hdr) 3295 { 3296 3297 /* Is logging enabled? */ 3298 if (tcp_log_debug == 0) 3299 return (NULL); 3300 3301 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3302 } 3303 3304 static char * 3305 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3306 const void *ip6hdr) 3307 { 3308 char *s, *sp; 3309 size_t size; 3310 struct ip *ip; 3311 #ifdef INET6 3312 const struct ip6_hdr *ip6; 3313 3314 ip6 = (const struct ip6_hdr *)ip6hdr; 3315 #endif /* INET6 */ 3316 ip = (struct ip *)ip4hdr; 3317 3318 /* 3319 * The log line looks like this: 3320 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3321 */ 3322 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3323 sizeof(PRINT_TH_FLAGS) + 1 + 3324 #ifdef INET6 3325 2 * INET6_ADDRSTRLEN; 3326 #else 3327 2 * INET_ADDRSTRLEN; 3328 #endif /* INET6 */ 3329 3330 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3331 if (s == NULL) 3332 return (NULL); 3333 3334 strcat(s, "TCP: ["); 3335 sp = s + strlen(s); 3336 3337 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3338 inet_ntoa_r(inc->inc_faddr, sp); 3339 sp = s + strlen(s); 3340 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3341 sp = s + strlen(s); 3342 inet_ntoa_r(inc->inc_laddr, sp); 3343 sp = s + strlen(s); 3344 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3345 #ifdef INET6 3346 } else if (inc) { 3347 ip6_sprintf(sp, &inc->inc6_faddr); 3348 sp = s + strlen(s); 3349 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3350 sp = s + strlen(s); 3351 ip6_sprintf(sp, &inc->inc6_laddr); 3352 sp = s + strlen(s); 3353 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3354 } else if (ip6 && th) { 3355 ip6_sprintf(sp, &ip6->ip6_src); 3356 sp = s + strlen(s); 3357 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3358 sp = s + strlen(s); 3359 ip6_sprintf(sp, &ip6->ip6_dst); 3360 sp = s + strlen(s); 3361 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3362 #endif /* INET6 */ 3363 #ifdef INET 3364 } else if (ip && th) { 3365 inet_ntoa_r(ip->ip_src, sp); 3366 sp = s + strlen(s); 3367 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3368 sp = s + strlen(s); 3369 inet_ntoa_r(ip->ip_dst, sp); 3370 sp = s + strlen(s); 3371 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3372 #endif /* INET */ 3373 } else { 3374 free(s, M_TCPLOG); 3375 return (NULL); 3376 } 3377 sp = s + strlen(s); 3378 if (th) 3379 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3380 if (*(s + size - 1) != '\0') 3381 panic("%s: string too long", __func__); 3382 return (s); 3383 } 3384 3385 /* 3386 * A subroutine which makes it easy to track TCP state changes with DTrace. 3387 * This function shouldn't be called for t_state initializations that don't 3388 * correspond to actual TCP state transitions. 3389 */ 3390 void 3391 tcp_state_change(struct tcpcb *tp, int newstate) 3392 { 3393 #if defined(KDTRACE_HOOKS) 3394 int pstate = tp->t_state; 3395 #endif 3396 3397 TCPSTATES_DEC(tp->t_state); 3398 TCPSTATES_INC(newstate); 3399 tp->t_state = newstate; 3400 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3401 } 3402 3403 /* 3404 * Create an external-format (``xtcpcb'') structure using the information in 3405 * the kernel-format tcpcb structure pointed to by tp. This is done to 3406 * reduce the spew of irrelevant information over this interface, to isolate 3407 * user code from changes in the kernel structure, and potentially to provide 3408 * information-hiding if we decide that some of this information should be 3409 * hidden from users. 3410 */ 3411 void 3412 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3413 { 3414 struct tcpcb *tp = intotcpcb(inp); 3415 sbintime_t now; 3416 3417 bzero(xt, sizeof(*xt)); 3418 if (inp->inp_flags & INP_TIMEWAIT) { 3419 xt->t_state = TCPS_TIME_WAIT; 3420 } else { 3421 xt->t_state = tp->t_state; 3422 xt->t_logstate = tp->t_logstate; 3423 xt->t_flags = tp->t_flags; 3424 xt->t_sndzerowin = tp->t_sndzerowin; 3425 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3426 xt->t_rcvoopack = tp->t_rcvoopack; 3427 3428 now = getsbinuptime(); 3429 #define COPYTIMER(ttt) do { \ 3430 if (callout_active(&tp->t_timers->ttt)) \ 3431 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3432 SBT_1MS; \ 3433 else \ 3434 xt->ttt = 0; \ 3435 } while (0) 3436 COPYTIMER(tt_delack); 3437 COPYTIMER(tt_rexmt); 3438 COPYTIMER(tt_persist); 3439 COPYTIMER(tt_keep); 3440 COPYTIMER(tt_2msl); 3441 #undef COPYTIMER 3442 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3443 3444 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3445 TCP_FUNCTION_NAME_LEN_MAX); 3446 #ifdef TCP_BLACKBOX 3447 (void)tcp_log_get_id(tp, xt->xt_logid); 3448 #endif 3449 } 3450 3451 xt->xt_len = sizeof(struct xtcpcb); 3452 in_pcbtoxinpcb(inp, &xt->xt_inp); 3453 if (inp->inp_socket == NULL) 3454 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 3455 } 3456