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 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/sdt.h> 68 #include <sys/socket.h> 69 #include <sys/socketvar.h> 70 #include <sys/protosw.h> 71 #include <sys/random.h> 72 73 #include <vm/uma.h> 74 75 #include <net/route.h> 76 #include <net/route/nhop.h> 77 #include <net/if.h> 78 #include <net/if_var.h> 79 #include <net/vnet.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_fib.h> 83 #include <netinet/in_kdtrace.h> 84 #include <netinet/in_pcb.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip.h> 88 #include <netinet/ip_icmp.h> 89 #include <netinet/ip_var.h> 90 #ifdef INET6 91 #include <netinet/icmp6.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/in6_fib.h> 94 #include <netinet6/in6_pcb.h> 95 #include <netinet6/ip6_var.h> 96 #include <netinet6/scope6_var.h> 97 #include <netinet6/nd6.h> 98 #endif 99 100 #include <netinet/tcp.h> 101 #ifdef INVARIANTS 102 #define TCPSTATES 103 #endif 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_ecn.h> 109 #include <netinet/tcp_log_buf.h> 110 #include <netinet/tcp_syncache.h> 111 #include <netinet/tcp_hpts.h> 112 #include <netinet/cc/cc.h> 113 #include <netinet/tcpip.h> 114 #include <netinet/tcp_fastopen.h> 115 #ifdef TCPPCAP 116 #include <netinet/tcp_pcap.h> 117 #endif 118 #ifdef TCPDEBUG 119 #include <netinet/tcp_debug.h> 120 #endif 121 #ifdef TCP_OFFLOAD 122 #include <netinet/tcp_offload.h> 123 #endif 124 #include <netinet/udp.h> 125 #include <netinet/udp_var.h> 126 #ifdef INET6 127 #include <netinet6/tcp6_var.h> 128 #endif 129 130 #include <netipsec/ipsec_support.h> 131 132 #include <machine/in_cksum.h> 133 #include <crypto/siphash/siphash.h> 134 135 #include <security/mac/mac_framework.h> 136 137 #ifdef INET6 138 static ip6proto_ctlinput_t tcp6_ctlinput; 139 static udp_tun_icmp_t tcp6_ctlinput_viaudp; 140 #endif 141 142 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 143 #ifdef INET6 144 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 145 #endif 146 147 #ifdef NETFLIX_EXP_DETECTION 148 /* Sack attack detection thresholds and such */ 149 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 150 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 151 "Sack Attack detection thresholds"); 152 int32_t tcp_force_detection = 0; 153 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 154 CTLFLAG_RW, 155 &tcp_force_detection, 0, 156 "Do we force detection even if the INP has it off?"); 157 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 158 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 159 CTLFLAG_RW, 160 &tcp_sack_to_ack_thresh, 700, 161 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 162 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 163 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 164 CTLFLAG_RW, 165 &tcp_sack_to_move_thresh, 600, 166 "Percentage of sack moves we must see above (10.1 percent is 101)"); 167 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 168 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 169 CTLFLAG_RW, 170 &tcp_restoral_thresh, 550, 171 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 172 int32_t tcp_sad_decay_val = 800; 173 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 174 CTLFLAG_RW, 175 &tcp_sad_decay_val, 800, 176 "The decay percentage (10.1 percent equals 101 )"); 177 int32_t tcp_map_minimum = 500; 178 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 179 CTLFLAG_RW, 180 &tcp_map_minimum, 500, 181 "Number of Map enteries before we start detection"); 182 int32_t tcp_attack_on_turns_on_logging = 0; 183 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 184 CTLFLAG_RW, 185 &tcp_attack_on_turns_on_logging, 0, 186 "When we have a positive hit on attack, do we turn on logging?"); 187 int32_t tcp_sad_pacing_interval = 2000; 188 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 189 CTLFLAG_RW, 190 &tcp_sad_pacing_interval, 2000, 191 "What is the minimum pacing interval for a classified attacker?"); 192 193 int32_t tcp_sad_low_pps = 100; 194 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 195 CTLFLAG_RW, 196 &tcp_sad_low_pps, 100, 197 "What is the input pps that below which we do not decay?"); 198 #endif 199 uint32_t tcp_ack_war_time_window = 1000; 200 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 201 CTLFLAG_RW, 202 &tcp_ack_war_time_window, 1000, 203 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 204 uint32_t tcp_ack_war_cnt = 5; 205 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 206 CTLFLAG_RW, 207 &tcp_ack_war_cnt, 5, 208 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 209 210 struct rwlock tcp_function_lock; 211 212 static int 213 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 214 { 215 int error, new; 216 217 new = V_tcp_mssdflt; 218 error = sysctl_handle_int(oidp, &new, 0, req); 219 if (error == 0 && req->newptr) { 220 if (new < TCP_MINMSS) 221 error = EINVAL; 222 else 223 V_tcp_mssdflt = new; 224 } 225 return (error); 226 } 227 228 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 229 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 230 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 231 "Default TCP Maximum Segment Size"); 232 233 #ifdef INET6 234 static int 235 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 236 { 237 int error, new; 238 239 new = V_tcp_v6mssdflt; 240 error = sysctl_handle_int(oidp, &new, 0, req); 241 if (error == 0 && req->newptr) { 242 if (new < TCP_MINMSS) 243 error = EINVAL; 244 else 245 V_tcp_v6mssdflt = new; 246 } 247 return (error); 248 } 249 250 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 251 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 252 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 253 "Default TCP Maximum Segment Size for IPv6"); 254 #endif /* INET6 */ 255 256 /* 257 * Minimum MSS we accept and use. This prevents DoS attacks where 258 * we are forced to a ridiculous low MSS like 20 and send hundreds 259 * of packets instead of one. The effect scales with the available 260 * bandwidth and quickly saturates the CPU and network interface 261 * with packet generation and sending. Set to zero to disable MINMSS 262 * checking. This setting prevents us from sending too small packets. 263 */ 264 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 265 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 266 &VNET_NAME(tcp_minmss), 0, 267 "Minimum TCP Maximum Segment Size"); 268 269 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 270 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 271 &VNET_NAME(tcp_do_rfc1323), 0, 272 "Enable rfc1323 (high performance TCP) extensions"); 273 274 /* 275 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 276 * Some stacks negotiate TS, but never send them after connection setup. Some 277 * stacks negotiate TS, but don't send them when sending keep-alive segments. 278 * These include modern widely deployed TCP stacks. 279 * Therefore tolerating violations for now... 280 */ 281 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 282 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 283 &VNET_NAME(tcp_tolerate_missing_ts), 0, 284 "Tolerate missing TCP timestamps"); 285 286 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 287 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 288 &VNET_NAME(tcp_ts_offset_per_conn), 0, 289 "Initialize TCP timestamps per connection instead of per host pair"); 290 291 /* How many connections are pacing */ 292 static volatile uint32_t number_of_tcp_connections_pacing = 0; 293 static uint32_t shadow_num_connections = 0; 294 295 static int tcp_pacing_limit = 10000; 296 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 297 &tcp_pacing_limit, 1000, 298 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 299 300 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 301 &shadow_num_connections, 0, "Number of TCP connections being paced"); 302 303 static int tcp_log_debug = 0; 304 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 305 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 306 307 static int tcp_tcbhashsize; 308 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 309 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 310 311 static int do_tcpdrain = 1; 312 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 313 "Enable tcp_drain routine for extra help when low on mbufs"); 314 315 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 316 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 317 318 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 319 #define V_icmp_may_rst VNET(icmp_may_rst) 320 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 321 &VNET_NAME(icmp_may_rst), 0, 322 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 323 324 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 325 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 326 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 327 &VNET_NAME(tcp_isn_reseed_interval), 0, 328 "Seconds between reseeding of ISN secret"); 329 330 static int tcp_soreceive_stream; 331 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 332 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 333 334 VNET_DEFINE(uma_zone_t, sack_hole_zone); 335 #define V_sack_hole_zone VNET(sack_hole_zone) 336 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 337 static int 338 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 339 { 340 int error; 341 uint32_t new; 342 343 new = V_tcp_map_entries_limit; 344 error = sysctl_handle_int(oidp, &new, 0, req); 345 if (error == 0 && req->newptr) { 346 /* only allow "0" and value > minimum */ 347 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 348 error = EINVAL; 349 else 350 V_tcp_map_entries_limit = new; 351 } 352 return (error); 353 } 354 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 355 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 356 &VNET_NAME(tcp_map_entries_limit), 0, 357 &sysctl_net_inet_tcp_map_limit_check, "IU", 358 "Total sendmap entries limit"); 359 360 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 361 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 362 &VNET_NAME(tcp_map_split_limit), 0, 363 "Total sendmap split entries limit"); 364 365 #ifdef TCP_HHOOK 366 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 367 #endif 368 369 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 370 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 371 #define V_ts_offset_secret VNET(ts_offset_secret) 372 373 static int tcp_default_fb_init(struct tcpcb *tp); 374 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 375 static int tcp_default_handoff_ok(struct tcpcb *tp); 376 static struct inpcb *tcp_notify(struct inpcb *, int); 377 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 378 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 379 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int); 380 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 381 const void *ip4hdr, const void *ip6hdr); 382 static ipproto_ctlinput_t tcp_ctlinput; 383 static udp_tun_icmp_t tcp_ctlinput_viaudp; 384 385 static struct tcp_function_block tcp_def_funcblk = { 386 .tfb_tcp_block_name = "freebsd", 387 .tfb_tcp_output = tcp_default_output, 388 .tfb_tcp_do_segment = tcp_do_segment, 389 .tfb_tcp_ctloutput = tcp_default_ctloutput, 390 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 391 .tfb_tcp_fb_init = tcp_default_fb_init, 392 .tfb_tcp_fb_fini = tcp_default_fb_fini, 393 }; 394 395 static int tcp_fb_cnt = 0; 396 struct tcp_funchead t_functions; 397 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 398 399 void 400 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 401 { 402 TCPSTAT_INC(tcps_dsack_count); 403 tp->t_dsack_pack++; 404 if (tlp == 0) { 405 if (SEQ_GT(end, start)) { 406 tp->t_dsack_bytes += (end - start); 407 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 408 } else { 409 tp->t_dsack_tlp_bytes += (start - end); 410 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 411 } 412 } else { 413 if (SEQ_GT(end, start)) { 414 tp->t_dsack_bytes += (end - start); 415 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 416 } else { 417 tp->t_dsack_tlp_bytes += (start - end); 418 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 419 } 420 } 421 } 422 423 static struct tcp_function_block * 424 find_tcp_functions_locked(struct tcp_function_set *fs) 425 { 426 struct tcp_function *f; 427 struct tcp_function_block *blk=NULL; 428 429 TAILQ_FOREACH(f, &t_functions, tf_next) { 430 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 431 blk = f->tf_fb; 432 break; 433 } 434 } 435 return(blk); 436 } 437 438 static struct tcp_function_block * 439 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 440 { 441 struct tcp_function_block *rblk=NULL; 442 struct tcp_function *f; 443 444 TAILQ_FOREACH(f, &t_functions, tf_next) { 445 if (f->tf_fb == blk) { 446 rblk = blk; 447 if (s) { 448 *s = f; 449 } 450 break; 451 } 452 } 453 return (rblk); 454 } 455 456 struct tcp_function_block * 457 find_and_ref_tcp_functions(struct tcp_function_set *fs) 458 { 459 struct tcp_function_block *blk; 460 461 rw_rlock(&tcp_function_lock); 462 blk = find_tcp_functions_locked(fs); 463 if (blk) 464 refcount_acquire(&blk->tfb_refcnt); 465 rw_runlock(&tcp_function_lock); 466 return(blk); 467 } 468 469 struct tcp_function_block * 470 find_and_ref_tcp_fb(struct tcp_function_block *blk) 471 { 472 struct tcp_function_block *rblk; 473 474 rw_rlock(&tcp_function_lock); 475 rblk = find_tcp_fb_locked(blk, NULL); 476 if (rblk) 477 refcount_acquire(&rblk->tfb_refcnt); 478 rw_runlock(&tcp_function_lock); 479 return(rblk); 480 } 481 482 /* Find a matching alias for the given tcp_function_block. */ 483 int 484 find_tcp_function_alias(struct tcp_function_block *blk, 485 struct tcp_function_set *fs) 486 { 487 struct tcp_function *f; 488 int found; 489 490 found = 0; 491 rw_rlock(&tcp_function_lock); 492 TAILQ_FOREACH(f, &t_functions, tf_next) { 493 if ((f->tf_fb == blk) && 494 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 495 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 496 /* Matching function block with different name. */ 497 strncpy(fs->function_set_name, f->tf_name, 498 TCP_FUNCTION_NAME_LEN_MAX); 499 found = 1; 500 break; 501 } 502 } 503 /* Null terminate the string appropriately. */ 504 if (found) { 505 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 506 } else { 507 fs->function_set_name[0] = '\0'; 508 } 509 rw_runlock(&tcp_function_lock); 510 return (found); 511 } 512 513 static struct tcp_function_block * 514 find_and_ref_tcp_default_fb(void) 515 { 516 struct tcp_function_block *rblk; 517 518 rw_rlock(&tcp_function_lock); 519 rblk = tcp_func_set_ptr; 520 refcount_acquire(&rblk->tfb_refcnt); 521 rw_runlock(&tcp_function_lock); 522 return (rblk); 523 } 524 525 void 526 tcp_switch_back_to_default(struct tcpcb *tp) 527 { 528 struct tcp_function_block *tfb; 529 530 KASSERT(tp->t_fb != &tcp_def_funcblk, 531 ("%s: called by the built-in default stack", __func__)); 532 533 /* 534 * Release the old stack. This function will either find a new one 535 * or panic. 536 */ 537 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 538 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 539 refcount_release(&tp->t_fb->tfb_refcnt); 540 541 /* 542 * Now, we'll find a new function block to use. 543 * Start by trying the current user-selected 544 * default, unless this stack is the user-selected 545 * default. 546 */ 547 tfb = find_and_ref_tcp_default_fb(); 548 if (tfb == tp->t_fb) { 549 refcount_release(&tfb->tfb_refcnt); 550 tfb = NULL; 551 } 552 /* Does the stack accept this connection? */ 553 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 554 (*tfb->tfb_tcp_handoff_ok)(tp)) { 555 refcount_release(&tfb->tfb_refcnt); 556 tfb = NULL; 557 } 558 /* Try to use that stack. */ 559 if (tfb != NULL) { 560 /* Initialize the new stack. If it succeeds, we are done. */ 561 tp->t_fb = tfb; 562 if (tp->t_fb->tfb_tcp_fb_init == NULL || 563 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 564 return; 565 566 /* 567 * Initialization failed. Release the reference count on 568 * the stack. 569 */ 570 refcount_release(&tfb->tfb_refcnt); 571 } 572 573 /* 574 * If that wasn't feasible, use the built-in default 575 * stack which is not allowed to reject anyone. 576 */ 577 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 578 if (tfb == NULL) { 579 /* there always should be a default */ 580 panic("Can't refer to tcp_def_funcblk"); 581 } 582 if (tfb->tfb_tcp_handoff_ok != NULL) { 583 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 584 /* The default stack cannot say no */ 585 panic("Default stack rejects a new session?"); 586 } 587 } 588 tp->t_fb = tfb; 589 if (tp->t_fb->tfb_tcp_fb_init != NULL && 590 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 591 /* The default stack cannot fail */ 592 panic("Default stack initialization failed"); 593 } 594 } 595 596 static bool 597 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 598 const struct sockaddr *sa, void *ctx) 599 { 600 struct ip *iph; 601 #ifdef INET6 602 struct ip6_hdr *ip6; 603 #endif 604 struct udphdr *uh; 605 struct tcphdr *th; 606 int thlen; 607 uint16_t port; 608 609 TCPSTAT_INC(tcps_tunneled_pkts); 610 if ((m->m_flags & M_PKTHDR) == 0) { 611 /* Can't handle one that is not a pkt hdr */ 612 TCPSTAT_INC(tcps_tunneled_errs); 613 goto out; 614 } 615 thlen = sizeof(struct tcphdr); 616 if (m->m_len < off + sizeof(struct udphdr) + thlen && 617 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 618 TCPSTAT_INC(tcps_tunneled_errs); 619 goto out; 620 } 621 iph = mtod(m, struct ip *); 622 uh = (struct udphdr *)((caddr_t)iph + off); 623 th = (struct tcphdr *)(uh + 1); 624 thlen = th->th_off << 2; 625 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 626 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 627 if (m == NULL) { 628 TCPSTAT_INC(tcps_tunneled_errs); 629 goto out; 630 } else { 631 iph = mtod(m, struct ip *); 632 uh = (struct udphdr *)((caddr_t)iph + off); 633 th = (struct tcphdr *)(uh + 1); 634 } 635 } 636 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 637 bcopy(th, uh, m->m_len - off); 638 m->m_len -= sizeof(struct udphdr); 639 m->m_pkthdr.len -= sizeof(struct udphdr); 640 /* 641 * We use the same algorithm for 642 * both UDP and TCP for c-sum. So 643 * the code in tcp_input will skip 644 * the checksum. So we do nothing 645 * with the flag (m->m_pkthdr.csum_flags). 646 */ 647 switch (iph->ip_v) { 648 #ifdef INET 649 case IPVERSION: 650 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 651 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 652 break; 653 #endif 654 #ifdef INET6 655 case IPV6_VERSION >> 4: 656 ip6 = mtod(m, struct ip6_hdr *); 657 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 658 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 659 break; 660 #endif 661 default: 662 goto out; 663 break; 664 } 665 return (true); 666 out: 667 m_freem(m); 668 669 return (true); 670 } 671 672 static int 673 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 674 { 675 int error=ENOENT; 676 struct tcp_function_set fs; 677 struct tcp_function_block *blk; 678 679 memset(&fs, 0, sizeof(fs)); 680 rw_rlock(&tcp_function_lock); 681 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 682 if (blk) { 683 /* Found him */ 684 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 685 fs.pcbcnt = blk->tfb_refcnt; 686 } 687 rw_runlock(&tcp_function_lock); 688 error = sysctl_handle_string(oidp, fs.function_set_name, 689 sizeof(fs.function_set_name), req); 690 691 /* Check for error or no change */ 692 if (error != 0 || req->newptr == NULL) 693 return(error); 694 695 rw_wlock(&tcp_function_lock); 696 blk = find_tcp_functions_locked(&fs); 697 if ((blk == NULL) || 698 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 699 error = ENOENT; 700 goto done; 701 } 702 tcp_func_set_ptr = blk; 703 done: 704 rw_wunlock(&tcp_function_lock); 705 return (error); 706 } 707 708 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 709 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 710 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 711 "Set/get the default TCP functions"); 712 713 static int 714 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 715 { 716 int error, cnt, linesz; 717 struct tcp_function *f; 718 char *buffer, *cp; 719 size_t bufsz, outsz; 720 bool alias; 721 722 cnt = 0; 723 rw_rlock(&tcp_function_lock); 724 TAILQ_FOREACH(f, &t_functions, tf_next) { 725 cnt++; 726 } 727 rw_runlock(&tcp_function_lock); 728 729 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 730 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 731 732 error = 0; 733 cp = buffer; 734 735 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 736 "Alias", "PCB count"); 737 cp += linesz; 738 bufsz -= linesz; 739 outsz = linesz; 740 741 rw_rlock(&tcp_function_lock); 742 TAILQ_FOREACH(f, &t_functions, tf_next) { 743 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 744 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 745 f->tf_fb->tfb_tcp_block_name, 746 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 747 alias ? f->tf_name : "-", 748 f->tf_fb->tfb_refcnt); 749 if (linesz >= bufsz) { 750 error = EOVERFLOW; 751 break; 752 } 753 cp += linesz; 754 bufsz -= linesz; 755 outsz += linesz; 756 } 757 rw_runlock(&tcp_function_lock); 758 if (error == 0) 759 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 760 free(buffer, M_TEMP); 761 return (error); 762 } 763 764 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 765 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 766 NULL, 0, sysctl_net_inet_list_available, "A", 767 "list available TCP Function sets"); 768 769 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 770 771 #ifdef INET 772 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 773 #define V_udp4_tun_socket VNET(udp4_tun_socket) 774 #endif 775 #ifdef INET6 776 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 777 #define V_udp6_tun_socket VNET(udp6_tun_socket) 778 #endif 779 780 static void 781 tcp_over_udp_stop(void) 782 { 783 /* 784 * This function assumes sysctl caller holds inp_rinfo_lock() 785 * for writing! 786 */ 787 #ifdef INET 788 if (V_udp4_tun_socket != NULL) { 789 soclose(V_udp4_tun_socket); 790 V_udp4_tun_socket = NULL; 791 } 792 #endif 793 #ifdef INET6 794 if (V_udp6_tun_socket != NULL) { 795 soclose(V_udp6_tun_socket); 796 V_udp6_tun_socket = NULL; 797 } 798 #endif 799 } 800 801 static int 802 tcp_over_udp_start(void) 803 { 804 uint16_t port; 805 int ret; 806 #ifdef INET 807 struct sockaddr_in sin; 808 #endif 809 #ifdef INET6 810 struct sockaddr_in6 sin6; 811 #endif 812 /* 813 * This function assumes sysctl caller holds inp_info_rlock() 814 * for writing! 815 */ 816 port = V_tcp_udp_tunneling_port; 817 if (ntohs(port) == 0) { 818 /* Must have a port set */ 819 return (EINVAL); 820 } 821 #ifdef INET 822 if (V_udp4_tun_socket != NULL) { 823 /* Already running -- must stop first */ 824 return (EALREADY); 825 } 826 #endif 827 #ifdef INET6 828 if (V_udp6_tun_socket != NULL) { 829 /* Already running -- must stop first */ 830 return (EALREADY); 831 } 832 #endif 833 #ifdef INET 834 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 835 SOCK_DGRAM, IPPROTO_UDP, 836 curthread->td_ucred, curthread))) { 837 tcp_over_udp_stop(); 838 return (ret); 839 } 840 /* Call the special UDP hook. */ 841 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 842 tcp_recv_udp_tunneled_packet, 843 tcp_ctlinput_viaudp, 844 NULL))) { 845 tcp_over_udp_stop(); 846 return (ret); 847 } 848 /* Ok, we have a socket, bind it to the port. */ 849 memset(&sin, 0, sizeof(struct sockaddr_in)); 850 sin.sin_len = sizeof(struct sockaddr_in); 851 sin.sin_family = AF_INET; 852 sin.sin_port = htons(port); 853 if ((ret = sobind(V_udp4_tun_socket, 854 (struct sockaddr *)&sin, curthread))) { 855 tcp_over_udp_stop(); 856 return (ret); 857 } 858 #endif 859 #ifdef INET6 860 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 861 SOCK_DGRAM, IPPROTO_UDP, 862 curthread->td_ucred, curthread))) { 863 tcp_over_udp_stop(); 864 return (ret); 865 } 866 /* Call the special UDP hook. */ 867 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 868 tcp_recv_udp_tunneled_packet, 869 tcp6_ctlinput_viaudp, 870 NULL))) { 871 tcp_over_udp_stop(); 872 return (ret); 873 } 874 /* Ok, we have a socket, bind it to the port. */ 875 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 876 sin6.sin6_len = sizeof(struct sockaddr_in6); 877 sin6.sin6_family = AF_INET6; 878 sin6.sin6_port = htons(port); 879 if ((ret = sobind(V_udp6_tun_socket, 880 (struct sockaddr *)&sin6, curthread))) { 881 tcp_over_udp_stop(); 882 return (ret); 883 } 884 #endif 885 return (0); 886 } 887 888 static int 889 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 890 { 891 int error; 892 uint32_t old, new; 893 894 old = V_tcp_udp_tunneling_port; 895 new = old; 896 error = sysctl_handle_int(oidp, &new, 0, req); 897 if ((error == 0) && 898 (req->newptr != NULL)) { 899 if ((new < TCP_TUNNELING_PORT_MIN) || 900 (new > TCP_TUNNELING_PORT_MAX)) { 901 error = EINVAL; 902 } else { 903 V_tcp_udp_tunneling_port = new; 904 if (old != 0) { 905 tcp_over_udp_stop(); 906 } 907 if (new != 0) { 908 error = tcp_over_udp_start(); 909 } 910 } 911 } 912 return (error); 913 } 914 915 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 916 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 917 &VNET_NAME(tcp_udp_tunneling_port), 918 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 919 "Tunneling port for tcp over udp"); 920 921 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 922 923 static int 924 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 925 { 926 int error, new; 927 928 new = V_tcp_udp_tunneling_overhead; 929 error = sysctl_handle_int(oidp, &new, 0, req); 930 if (error == 0 && req->newptr) { 931 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 932 (new > TCP_TUNNELING_OVERHEAD_MAX)) 933 error = EINVAL; 934 else 935 V_tcp_udp_tunneling_overhead = new; 936 } 937 return (error); 938 } 939 940 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 941 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 942 &VNET_NAME(tcp_udp_tunneling_overhead), 943 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 944 "MSS reduction when using tcp over udp"); 945 946 /* 947 * Exports one (struct tcp_function_info) for each alias/name. 948 */ 949 static int 950 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 951 { 952 int cnt, error; 953 struct tcp_function *f; 954 struct tcp_function_info tfi; 955 956 /* 957 * We don't allow writes. 958 */ 959 if (req->newptr != NULL) 960 return (EINVAL); 961 962 /* 963 * Wire the old buffer so we can directly copy the functions to 964 * user space without dropping the lock. 965 */ 966 if (req->oldptr != NULL) { 967 error = sysctl_wire_old_buffer(req, 0); 968 if (error) 969 return (error); 970 } 971 972 /* 973 * Walk the list and copy out matching entries. If INVARIANTS 974 * is compiled in, also walk the list to verify the length of 975 * the list matches what we have recorded. 976 */ 977 rw_rlock(&tcp_function_lock); 978 979 cnt = 0; 980 #ifndef INVARIANTS 981 if (req->oldptr == NULL) { 982 cnt = tcp_fb_cnt; 983 goto skip_loop; 984 } 985 #endif 986 TAILQ_FOREACH(f, &t_functions, tf_next) { 987 #ifdef INVARIANTS 988 cnt++; 989 #endif 990 if (req->oldptr != NULL) { 991 bzero(&tfi, sizeof(tfi)); 992 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 993 tfi.tfi_id = f->tf_fb->tfb_id; 994 (void)strlcpy(tfi.tfi_alias, f->tf_name, 995 sizeof(tfi.tfi_alias)); 996 (void)strlcpy(tfi.tfi_name, 997 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 998 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 999 /* 1000 * Don't stop on error, as that is the 1001 * mechanism we use to accumulate length 1002 * information if the buffer was too short. 1003 */ 1004 } 1005 } 1006 KASSERT(cnt == tcp_fb_cnt, 1007 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1008 #ifndef INVARIANTS 1009 skip_loop: 1010 #endif 1011 rw_runlock(&tcp_function_lock); 1012 if (req->oldptr == NULL) 1013 error = SYSCTL_OUT(req, NULL, 1014 (cnt + 1) * sizeof(struct tcp_function_info)); 1015 1016 return (error); 1017 } 1018 1019 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1020 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1021 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1022 "List TCP function block name-to-ID mappings"); 1023 1024 /* 1025 * tfb_tcp_handoff_ok() function for the default stack. 1026 * Note that we'll basically try to take all comers. 1027 */ 1028 static int 1029 tcp_default_handoff_ok(struct tcpcb *tp) 1030 { 1031 1032 return (0); 1033 } 1034 1035 /* 1036 * tfb_tcp_fb_init() function for the default stack. 1037 * 1038 * This handles making sure we have appropriate timers set if you are 1039 * transitioning a socket that has some amount of setup done. 1040 * 1041 * The init() fuction from the default can *never* return non-zero i.e. 1042 * it is required to always succeed since it is the stack of last resort! 1043 */ 1044 static int 1045 tcp_default_fb_init(struct tcpcb *tp) 1046 { 1047 struct socket *so = tptosocket(tp); 1048 1049 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1050 1051 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1052 ("%s: connection %p in unexpected state %d", __func__, tp, 1053 tp->t_state)); 1054 1055 /* 1056 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1057 * know what to do for unexpected states (which includes TIME_WAIT). 1058 */ 1059 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1060 return (0); 1061 1062 /* 1063 * Make sure some kind of transmission timer is set if there is 1064 * outstanding data. 1065 */ 1066 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1067 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1068 tcp_timer_active(tp, TT_PERSIST))) { 1069 /* 1070 * If the session has established and it looks like it should 1071 * be in the persist state, set the persist timer. Otherwise, 1072 * set the retransmit timer. 1073 */ 1074 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1075 (int32_t)(tp->snd_nxt - tp->snd_una) < 1076 (int32_t)sbavail(&so->so_snd)) 1077 tcp_setpersist(tp); 1078 else 1079 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1080 } 1081 1082 /* All non-embryonic sessions get a keepalive timer. */ 1083 if (!tcp_timer_active(tp, TT_KEEP)) 1084 tcp_timer_activate(tp, TT_KEEP, 1085 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1086 TP_KEEPINIT(tp)); 1087 1088 /* 1089 * Make sure critical variables are initialized 1090 * if transitioning while in Recovery. 1091 */ 1092 if IN_FASTRECOVERY(tp->t_flags) { 1093 if (tp->sackhint.recover_fs == 0) 1094 tp->sackhint.recover_fs = max(1, 1095 tp->snd_nxt - tp->snd_una); 1096 } 1097 1098 return (0); 1099 } 1100 1101 /* 1102 * tfb_tcp_fb_fini() function for the default stack. 1103 * 1104 * This changes state as necessary (or prudent) to prepare for another stack 1105 * to assume responsibility for the connection. 1106 */ 1107 static void 1108 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1109 { 1110 1111 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1112 } 1113 1114 /* 1115 * Target size of TCP PCB hash tables. Must be a power of two. 1116 * 1117 * Note that this can be overridden by the kernel environment 1118 * variable net.inet.tcp.tcbhashsize 1119 */ 1120 #ifndef TCBHASHSIZE 1121 #define TCBHASHSIZE 0 1122 #endif 1123 1124 /* 1125 * XXX 1126 * Callouts should be moved into struct tcp directly. They are currently 1127 * separate because the tcpcb structure is exported to userland for sysctl 1128 * parsing purposes, which do not know about callouts. 1129 */ 1130 struct tcpcb_mem { 1131 struct tcpcb tcb; 1132 struct tcp_timer tt; 1133 struct cc_var ccv; 1134 #ifdef TCP_HHOOK 1135 struct osd osd; 1136 #endif 1137 }; 1138 1139 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1140 #define V_tcpcb_zone VNET(tcpcb_zone) 1141 1142 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1143 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1144 1145 static struct mtx isn_mtx; 1146 1147 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1148 #define ISN_LOCK() mtx_lock(&isn_mtx) 1149 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1150 1151 INPCBSTORAGE_DEFINE(tcpcbstor, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1152 1153 /* 1154 * Take a value and get the next power of 2 that doesn't overflow. 1155 * Used to size the tcp_inpcb hash buckets. 1156 */ 1157 static int 1158 maketcp_hashsize(int size) 1159 { 1160 int hashsize; 1161 1162 /* 1163 * auto tune. 1164 * get the next power of 2 higher than maxsockets. 1165 */ 1166 hashsize = 1 << fls(size); 1167 /* catch overflow, and just go one power of 2 smaller */ 1168 if (hashsize < size) { 1169 hashsize = 1 << (fls(size) - 1); 1170 } 1171 return (hashsize); 1172 } 1173 1174 static volatile int next_tcp_stack_id = 1; 1175 1176 /* 1177 * Register a TCP function block with the name provided in the names 1178 * array. (Note that this function does NOT automatically register 1179 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1180 * explicitly include blk->tfb_tcp_block_name in the list of names if 1181 * you wish to register the stack with that name.) 1182 * 1183 * Either all name registrations will succeed or all will fail. If 1184 * a name registration fails, the function will update the num_names 1185 * argument to point to the array index of the name that encountered 1186 * the failure. 1187 * 1188 * Returns 0 on success, or an error code on failure. 1189 */ 1190 int 1191 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1192 const char *names[], int *num_names) 1193 { 1194 struct tcp_function *n; 1195 struct tcp_function_set fs; 1196 int error, i; 1197 1198 KASSERT(names != NULL && *num_names > 0, 1199 ("%s: Called with 0-length name list", __func__)); 1200 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1201 KASSERT(rw_initialized(&tcp_function_lock), 1202 ("%s: called too early", __func__)); 1203 1204 if ((blk->tfb_tcp_output == NULL) || 1205 (blk->tfb_tcp_do_segment == NULL) || 1206 (blk->tfb_tcp_ctloutput == NULL) || 1207 (strlen(blk->tfb_tcp_block_name) == 0)) { 1208 /* 1209 * These functions are required and you 1210 * need a name. 1211 */ 1212 *num_names = 0; 1213 return (EINVAL); 1214 } 1215 if (blk->tfb_tcp_timer_stop_all || 1216 blk->tfb_tcp_timer_activate || 1217 blk->tfb_tcp_timer_active || 1218 blk->tfb_tcp_timer_stop) { 1219 /* 1220 * If you define one timer function you 1221 * must have them all. 1222 */ 1223 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1224 (blk->tfb_tcp_timer_activate == NULL) || 1225 (blk->tfb_tcp_timer_active == NULL) || 1226 (blk->tfb_tcp_timer_stop == NULL)) { 1227 *num_names = 0; 1228 return (EINVAL); 1229 } 1230 } 1231 1232 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1233 *num_names = 0; 1234 return (EINVAL); 1235 } 1236 1237 refcount_init(&blk->tfb_refcnt, 0); 1238 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1239 for (i = 0; i < *num_names; i++) { 1240 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1241 if (n == NULL) { 1242 error = ENOMEM; 1243 goto cleanup; 1244 } 1245 n->tf_fb = blk; 1246 1247 (void)strlcpy(fs.function_set_name, names[i], 1248 sizeof(fs.function_set_name)); 1249 rw_wlock(&tcp_function_lock); 1250 if (find_tcp_functions_locked(&fs) != NULL) { 1251 /* Duplicate name space not allowed */ 1252 rw_wunlock(&tcp_function_lock); 1253 free(n, M_TCPFUNCTIONS); 1254 error = EALREADY; 1255 goto cleanup; 1256 } 1257 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1258 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1259 tcp_fb_cnt++; 1260 rw_wunlock(&tcp_function_lock); 1261 } 1262 return(0); 1263 1264 cleanup: 1265 /* 1266 * Deregister the names we just added. Because registration failed 1267 * for names[i], we don't need to deregister that name. 1268 */ 1269 *num_names = i; 1270 rw_wlock(&tcp_function_lock); 1271 while (--i >= 0) { 1272 TAILQ_FOREACH(n, &t_functions, tf_next) { 1273 if (!strncmp(n->tf_name, names[i], 1274 TCP_FUNCTION_NAME_LEN_MAX)) { 1275 TAILQ_REMOVE(&t_functions, n, tf_next); 1276 tcp_fb_cnt--; 1277 n->tf_fb = NULL; 1278 free(n, M_TCPFUNCTIONS); 1279 break; 1280 } 1281 } 1282 } 1283 rw_wunlock(&tcp_function_lock); 1284 return (error); 1285 } 1286 1287 /* 1288 * Register a TCP function block using the name provided in the name 1289 * argument. 1290 * 1291 * Returns 0 on success, or an error code on failure. 1292 */ 1293 int 1294 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1295 int wait) 1296 { 1297 const char *name_list[1]; 1298 int num_names, rv; 1299 1300 num_names = 1; 1301 if (name != NULL) 1302 name_list[0] = name; 1303 else 1304 name_list[0] = blk->tfb_tcp_block_name; 1305 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1306 return (rv); 1307 } 1308 1309 /* 1310 * Register a TCP function block using the name defined in 1311 * blk->tfb_tcp_block_name. 1312 * 1313 * Returns 0 on success, or an error code on failure. 1314 */ 1315 int 1316 register_tcp_functions(struct tcp_function_block *blk, int wait) 1317 { 1318 1319 return (register_tcp_functions_as_name(blk, NULL, wait)); 1320 } 1321 1322 /* 1323 * Deregister all names associated with a function block. This 1324 * functionally removes the function block from use within the system. 1325 * 1326 * When called with a true quiesce argument, mark the function block 1327 * as being removed so no more stacks will use it and determine 1328 * whether the removal would succeed. 1329 * 1330 * When called with a false quiesce argument, actually attempt the 1331 * removal. 1332 * 1333 * When called with a force argument, attempt to switch all TCBs to 1334 * use the default stack instead of returning EBUSY. 1335 * 1336 * Returns 0 on success (or if the removal would succeed, or an error 1337 * code on failure. 1338 */ 1339 int 1340 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1341 bool force) 1342 { 1343 struct tcp_function *f; 1344 1345 if (blk == &tcp_def_funcblk) { 1346 /* You can't un-register the default */ 1347 return (EPERM); 1348 } 1349 rw_wlock(&tcp_function_lock); 1350 if (blk == tcp_func_set_ptr) { 1351 /* You can't free the current default */ 1352 rw_wunlock(&tcp_function_lock); 1353 return (EBUSY); 1354 } 1355 /* Mark the block so no more stacks can use it. */ 1356 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1357 /* 1358 * If TCBs are still attached to the stack, attempt to switch them 1359 * to the default stack. 1360 */ 1361 if (force && blk->tfb_refcnt) { 1362 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1363 INPLOOKUP_WLOCKPCB); 1364 struct inpcb *inp; 1365 struct tcpcb *tp; 1366 VNET_ITERATOR_DECL(vnet_iter); 1367 1368 rw_wunlock(&tcp_function_lock); 1369 1370 VNET_LIST_RLOCK(); 1371 VNET_FOREACH(vnet_iter) { 1372 CURVNET_SET(vnet_iter); 1373 while ((inp = inp_next(&inpi)) != NULL) { 1374 tp = intotcpcb(inp); 1375 if (tp == NULL || tp->t_fb != blk) 1376 continue; 1377 tcp_switch_back_to_default(tp); 1378 } 1379 CURVNET_RESTORE(); 1380 } 1381 VNET_LIST_RUNLOCK(); 1382 1383 rw_wlock(&tcp_function_lock); 1384 } 1385 if (blk->tfb_refcnt) { 1386 /* TCBs still attached. */ 1387 rw_wunlock(&tcp_function_lock); 1388 return (EBUSY); 1389 } 1390 if (quiesce) { 1391 /* Skip removal. */ 1392 rw_wunlock(&tcp_function_lock); 1393 return (0); 1394 } 1395 /* Remove any function names that map to this function block. */ 1396 while (find_tcp_fb_locked(blk, &f) != NULL) { 1397 TAILQ_REMOVE(&t_functions, f, tf_next); 1398 tcp_fb_cnt--; 1399 f->tf_fb = NULL; 1400 free(f, M_TCPFUNCTIONS); 1401 } 1402 rw_wunlock(&tcp_function_lock); 1403 return (0); 1404 } 1405 1406 static void 1407 tcp_drain(void) 1408 { 1409 struct epoch_tracker et; 1410 VNET_ITERATOR_DECL(vnet_iter); 1411 1412 if (!do_tcpdrain) 1413 return; 1414 1415 NET_EPOCH_ENTER(et); 1416 VNET_LIST_RLOCK_NOSLEEP(); 1417 VNET_FOREACH(vnet_iter) { 1418 CURVNET_SET(vnet_iter); 1419 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1420 INPLOOKUP_WLOCKPCB); 1421 struct inpcb *inpb; 1422 struct tcpcb *tcpb; 1423 1424 /* 1425 * Walk the tcpbs, if existing, and flush the reassembly queue, 1426 * if there is one... 1427 * XXX: The "Net/3" implementation doesn't imply that the TCP 1428 * reassembly queue should be flushed, but in a situation 1429 * where we're really low on mbufs, this is potentially 1430 * useful. 1431 */ 1432 while ((inpb = inp_next(&inpi)) != NULL) { 1433 if ((tcpb = intotcpcb(inpb)) != NULL) { 1434 tcp_reass_flush(tcpb); 1435 tcp_clean_sackreport(tcpb); 1436 #ifdef TCP_BLACKBOX 1437 tcp_log_drain(tcpb); 1438 #endif 1439 #ifdef TCPPCAP 1440 if (tcp_pcap_aggressive_free) { 1441 /* Free the TCP PCAP queues. */ 1442 tcp_pcap_drain(&(tcpb->t_inpkts)); 1443 tcp_pcap_drain(&(tcpb->t_outpkts)); 1444 } 1445 #endif 1446 } 1447 } 1448 CURVNET_RESTORE(); 1449 } 1450 VNET_LIST_RUNLOCK_NOSLEEP(); 1451 NET_EPOCH_EXIT(et); 1452 } 1453 1454 static void 1455 tcp_vnet_init(void *arg __unused) 1456 { 1457 1458 #ifdef TCP_HHOOK 1459 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1460 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1461 printf("%s: WARNING: unable to register helper hook\n", __func__); 1462 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1463 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1464 printf("%s: WARNING: unable to register helper hook\n", __func__); 1465 #endif 1466 #ifdef STATS 1467 if (tcp_stats_init()) 1468 printf("%s: WARNING: unable to initialise TCP stats\n", 1469 __func__); 1470 #endif 1471 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1472 tcp_tcbhashsize); 1473 1474 /* 1475 * These have to be type stable for the benefit of the timers. 1476 */ 1477 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1478 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1479 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1480 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1481 1482 syncache_init(); 1483 tcp_hc_init(); 1484 1485 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1486 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1487 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1488 1489 tcp_fastopen_init(); 1490 1491 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1492 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1493 1494 V_tcp_msl = TCPTV_MSL; 1495 } 1496 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1497 tcp_vnet_init, NULL); 1498 1499 static void 1500 tcp_init(void *arg __unused) 1501 { 1502 const char *tcbhash_tuneable; 1503 int hashsize; 1504 1505 tcp_reass_global_init(); 1506 1507 /* XXX virtualize those below? */ 1508 tcp_delacktime = TCPTV_DELACK; 1509 tcp_keepinit = TCPTV_KEEP_INIT; 1510 tcp_keepidle = TCPTV_KEEP_IDLE; 1511 tcp_keepintvl = TCPTV_KEEPINTVL; 1512 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1513 tcp_rexmit_initial = TCPTV_RTOBASE; 1514 if (tcp_rexmit_initial < 1) 1515 tcp_rexmit_initial = 1; 1516 tcp_rexmit_min = TCPTV_MIN; 1517 if (tcp_rexmit_min < 1) 1518 tcp_rexmit_min = 1; 1519 tcp_persmin = TCPTV_PERSMIN; 1520 tcp_persmax = TCPTV_PERSMAX; 1521 tcp_rexmit_slop = TCPTV_CPU_VAR; 1522 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1523 1524 /* Setup the tcp function block list */ 1525 TAILQ_INIT(&t_functions); 1526 rw_init(&tcp_function_lock, "tcp_func_lock"); 1527 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1528 #ifdef TCP_BLACKBOX 1529 /* Initialize the TCP logging data. */ 1530 tcp_log_init(); 1531 #endif 1532 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1533 1534 if (tcp_soreceive_stream) { 1535 #ifdef INET 1536 tcp_protosw.pr_soreceive = soreceive_stream; 1537 #endif 1538 #ifdef INET6 1539 tcp6_protosw.pr_soreceive = soreceive_stream; 1540 #endif /* INET6 */ 1541 } 1542 1543 #ifdef INET6 1544 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1545 #else /* INET6 */ 1546 max_protohdr_grow(sizeof(struct tcpiphdr)); 1547 #endif /* INET6 */ 1548 1549 ISN_LOCK_INIT(); 1550 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1551 SHUTDOWN_PRI_DEFAULT); 1552 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1553 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1554 1555 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1556 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1557 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1558 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1559 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1560 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1561 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1562 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1563 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1564 #ifdef TCPPCAP 1565 tcp_pcap_init(); 1566 #endif 1567 1568 hashsize = TCBHASHSIZE; 1569 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1570 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1571 if (hashsize == 0) { 1572 /* 1573 * Auto tune the hash size based on maxsockets. 1574 * A perfect hash would have a 1:1 mapping 1575 * (hashsize = maxsockets) however it's been 1576 * suggested that O(2) average is better. 1577 */ 1578 hashsize = maketcp_hashsize(maxsockets / 4); 1579 /* 1580 * Our historical default is 512, 1581 * do not autotune lower than this. 1582 */ 1583 if (hashsize < 512) 1584 hashsize = 512; 1585 if (bootverbose) 1586 printf("%s: %s auto tuned to %d\n", __func__, 1587 tcbhash_tuneable, hashsize); 1588 } 1589 /* 1590 * We require a hashsize to be a power of two. 1591 * Previously if it was not a power of two we would just reset it 1592 * back to 512, which could be a nasty surprise if you did not notice 1593 * the error message. 1594 * Instead what we do is clip it to the closest power of two lower 1595 * than the specified hash value. 1596 */ 1597 if (!powerof2(hashsize)) { 1598 int oldhashsize = hashsize; 1599 1600 hashsize = maketcp_hashsize(hashsize); 1601 /* prevent absurdly low value */ 1602 if (hashsize < 16) 1603 hashsize = 16; 1604 printf("%s: WARNING: TCB hash size not a power of 2, " 1605 "clipped from %d to %d.\n", __func__, oldhashsize, 1606 hashsize); 1607 } 1608 tcp_tcbhashsize = hashsize; 1609 1610 #ifdef INET 1611 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1612 #endif 1613 #ifdef INET6 1614 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1615 #endif 1616 } 1617 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1618 1619 #ifdef VIMAGE 1620 static void 1621 tcp_destroy(void *unused __unused) 1622 { 1623 int n; 1624 #ifdef TCP_HHOOK 1625 int error; 1626 #endif 1627 1628 /* 1629 * All our processes are gone, all our sockets should be cleaned 1630 * up, which means, we should be past the tcp_discardcb() calls. 1631 * Sleep to let all tcpcb timers really disappear and cleanup. 1632 */ 1633 for (;;) { 1634 INP_INFO_WLOCK(&V_tcbinfo); 1635 n = V_tcbinfo.ipi_count; 1636 INP_INFO_WUNLOCK(&V_tcbinfo); 1637 if (n == 0) 1638 break; 1639 pause("tcpdes", hz / 10); 1640 } 1641 tcp_hc_destroy(); 1642 syncache_destroy(); 1643 in_pcbinfo_destroy(&V_tcbinfo); 1644 /* tcp_discardcb() clears the sack_holes up. */ 1645 uma_zdestroy(V_sack_hole_zone); 1646 uma_zdestroy(V_tcpcb_zone); 1647 1648 /* 1649 * Cannot free the zone until all tcpcbs are released as we attach 1650 * the allocations to them. 1651 */ 1652 tcp_fastopen_destroy(); 1653 1654 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1655 VNET_PCPUSTAT_FREE(tcpstat); 1656 1657 #ifdef TCP_HHOOK 1658 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1659 if (error != 0) { 1660 printf("%s: WARNING: unable to deregister helper hook " 1661 "type=%d, id=%d: error %d returned\n", __func__, 1662 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1663 } 1664 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1665 if (error != 0) { 1666 printf("%s: WARNING: unable to deregister helper hook " 1667 "type=%d, id=%d: error %d returned\n", __func__, 1668 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1669 } 1670 #endif 1671 } 1672 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1673 #endif 1674 1675 void 1676 tcp_fini(void *xtp) 1677 { 1678 1679 } 1680 1681 /* 1682 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1683 * tcp_template used to store this data in mbufs, but we now recopy it out 1684 * of the tcpcb each time to conserve mbufs. 1685 */ 1686 void 1687 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1688 { 1689 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1690 1691 INP_WLOCK_ASSERT(inp); 1692 1693 #ifdef INET6 1694 if ((inp->inp_vflag & INP_IPV6) != 0) { 1695 struct ip6_hdr *ip6; 1696 1697 ip6 = (struct ip6_hdr *)ip_ptr; 1698 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1699 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1700 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1701 (IPV6_VERSION & IPV6_VERSION_MASK); 1702 if (port == 0) 1703 ip6->ip6_nxt = IPPROTO_TCP; 1704 else 1705 ip6->ip6_nxt = IPPROTO_UDP; 1706 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1707 ip6->ip6_src = inp->in6p_laddr; 1708 ip6->ip6_dst = inp->in6p_faddr; 1709 } 1710 #endif /* INET6 */ 1711 #if defined(INET6) && defined(INET) 1712 else 1713 #endif 1714 #ifdef INET 1715 { 1716 struct ip *ip; 1717 1718 ip = (struct ip *)ip_ptr; 1719 ip->ip_v = IPVERSION; 1720 ip->ip_hl = 5; 1721 ip->ip_tos = inp->inp_ip_tos; 1722 ip->ip_len = 0; 1723 ip->ip_id = 0; 1724 ip->ip_off = 0; 1725 ip->ip_ttl = inp->inp_ip_ttl; 1726 ip->ip_sum = 0; 1727 if (port == 0) 1728 ip->ip_p = IPPROTO_TCP; 1729 else 1730 ip->ip_p = IPPROTO_UDP; 1731 ip->ip_src = inp->inp_laddr; 1732 ip->ip_dst = inp->inp_faddr; 1733 } 1734 #endif /* INET */ 1735 th->th_sport = inp->inp_lport; 1736 th->th_dport = inp->inp_fport; 1737 th->th_seq = 0; 1738 th->th_ack = 0; 1739 th->th_off = 5; 1740 tcp_set_flags(th, 0); 1741 th->th_win = 0; 1742 th->th_urp = 0; 1743 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1744 } 1745 1746 /* 1747 * Create template to be used to send tcp packets on a connection. 1748 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1749 * use for this function is in keepalives, which use tcp_respond. 1750 */ 1751 struct tcptemp * 1752 tcpip_maketemplate(struct inpcb *inp) 1753 { 1754 struct tcptemp *t; 1755 1756 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1757 if (t == NULL) 1758 return (NULL); 1759 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1760 return (t); 1761 } 1762 1763 /* 1764 * Send a single message to the TCP at address specified by 1765 * the given TCP/IP header. If m == NULL, then we make a copy 1766 * of the tcpiphdr at th and send directly to the addressed host. 1767 * This is used to force keep alive messages out using the TCP 1768 * template for a connection. If flags are given then we send 1769 * a message back to the TCP which originated the segment th, 1770 * and discard the mbuf containing it and any other attached mbufs. 1771 * 1772 * In any case the ack and sequence number of the transmitted 1773 * segment are as specified by the parameters. 1774 * 1775 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1776 */ 1777 void 1778 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1779 tcp_seq ack, tcp_seq seq, uint16_t flags) 1780 { 1781 struct tcpopt to; 1782 struct inpcb *inp; 1783 struct ip *ip; 1784 struct mbuf *optm; 1785 struct udphdr *uh = NULL; 1786 struct tcphdr *nth; 1787 struct tcp_log_buffer *lgb; 1788 u_char *optp; 1789 #ifdef INET6 1790 struct ip6_hdr *ip6; 1791 int isipv6; 1792 #endif /* INET6 */ 1793 int optlen, tlen, win, ulen; 1794 int ect = 0; 1795 bool incl_opts; 1796 uint16_t port; 1797 int output_ret; 1798 #ifdef INVARIANTS 1799 int thflags = tcp_get_flags(th); 1800 #endif 1801 1802 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1803 NET_EPOCH_ASSERT(); 1804 1805 #ifdef INET6 1806 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1807 ip6 = ipgen; 1808 #endif /* INET6 */ 1809 ip = ipgen; 1810 1811 if (tp != NULL) { 1812 inp = tptoinpcb(tp); 1813 INP_LOCK_ASSERT(inp); 1814 } else 1815 inp = NULL; 1816 1817 if (m != NULL) { 1818 #ifdef INET6 1819 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1820 port = m->m_pkthdr.tcp_tun_port; 1821 else 1822 #endif 1823 if (ip && (ip->ip_p == IPPROTO_UDP)) 1824 port = m->m_pkthdr.tcp_tun_port; 1825 else 1826 port = 0; 1827 } else 1828 port = tp->t_port; 1829 1830 incl_opts = false; 1831 win = 0; 1832 if (tp != NULL) { 1833 if (!(flags & TH_RST)) { 1834 win = sbspace(&inp->inp_socket->so_rcv); 1835 if (win > TCP_MAXWIN << tp->rcv_scale) 1836 win = TCP_MAXWIN << tp->rcv_scale; 1837 } 1838 if ((tp->t_flags & TF_NOOPT) == 0) 1839 incl_opts = true; 1840 } 1841 if (m == NULL) { 1842 m = m_gethdr(M_NOWAIT, MT_DATA); 1843 if (m == NULL) 1844 return; 1845 m->m_data += max_linkhdr; 1846 #ifdef INET6 1847 if (isipv6) { 1848 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1849 sizeof(struct ip6_hdr)); 1850 ip6 = mtod(m, struct ip6_hdr *); 1851 nth = (struct tcphdr *)(ip6 + 1); 1852 if (port) { 1853 /* Insert a UDP header */ 1854 uh = (struct udphdr *)nth; 1855 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1856 uh->uh_dport = port; 1857 nth = (struct tcphdr *)(uh + 1); 1858 } 1859 } else 1860 #endif /* INET6 */ 1861 { 1862 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1863 ip = mtod(m, struct ip *); 1864 nth = (struct tcphdr *)(ip + 1); 1865 if (port) { 1866 /* Insert a UDP header */ 1867 uh = (struct udphdr *)nth; 1868 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1869 uh->uh_dport = port; 1870 nth = (struct tcphdr *)(uh + 1); 1871 } 1872 } 1873 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1874 flags = TH_ACK; 1875 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1876 struct mbuf *n; 1877 1878 /* Can't reuse 'm', allocate a new mbuf. */ 1879 n = m_gethdr(M_NOWAIT, MT_DATA); 1880 if (n == NULL) { 1881 m_freem(m); 1882 return; 1883 } 1884 1885 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1886 m_freem(m); 1887 m_freem(n); 1888 return; 1889 } 1890 1891 n->m_data += max_linkhdr; 1892 /* m_len is set later */ 1893 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1894 #ifdef INET6 1895 if (isipv6) { 1896 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1897 sizeof(struct ip6_hdr)); 1898 ip6 = mtod(n, struct ip6_hdr *); 1899 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1900 nth = (struct tcphdr *)(ip6 + 1); 1901 if (port) { 1902 /* Insert a UDP header */ 1903 uh = (struct udphdr *)nth; 1904 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1905 uh->uh_dport = port; 1906 nth = (struct tcphdr *)(uh + 1); 1907 } 1908 } else 1909 #endif /* INET6 */ 1910 { 1911 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1912 ip = mtod(n, struct ip *); 1913 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1914 nth = (struct tcphdr *)(ip + 1); 1915 if (port) { 1916 /* Insert a UDP header */ 1917 uh = (struct udphdr *)nth; 1918 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1919 uh->uh_dport = port; 1920 nth = (struct tcphdr *)(uh + 1); 1921 } 1922 } 1923 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1924 xchg(nth->th_dport, nth->th_sport, uint16_t); 1925 th = nth; 1926 m_freem(m); 1927 m = n; 1928 } else { 1929 /* 1930 * reuse the mbuf. 1931 * XXX MRT We inherit the FIB, which is lucky. 1932 */ 1933 m_freem(m->m_next); 1934 m->m_next = NULL; 1935 m->m_data = (caddr_t)ipgen; 1936 /* m_len is set later */ 1937 #ifdef INET6 1938 if (isipv6) { 1939 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1940 nth = (struct tcphdr *)(ip6 + 1); 1941 } else 1942 #endif /* INET6 */ 1943 { 1944 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1945 nth = (struct tcphdr *)(ip + 1); 1946 } 1947 if (th != nth) { 1948 /* 1949 * this is usually a case when an extension header 1950 * exists between the IPv6 header and the 1951 * TCP header. 1952 */ 1953 nth->th_sport = th->th_sport; 1954 nth->th_dport = th->th_dport; 1955 } 1956 xchg(nth->th_dport, nth->th_sport, uint16_t); 1957 #undef xchg 1958 } 1959 tlen = 0; 1960 #ifdef INET6 1961 if (isipv6) 1962 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1963 #endif 1964 #if defined(INET) && defined(INET6) 1965 else 1966 #endif 1967 #ifdef INET 1968 tlen = sizeof (struct tcpiphdr); 1969 #endif 1970 if (port) 1971 tlen += sizeof (struct udphdr); 1972 #ifdef INVARIANTS 1973 m->m_len = 0; 1974 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1975 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1976 m, tlen, (long)M_TRAILINGSPACE(m))); 1977 #endif 1978 m->m_len = tlen; 1979 to.to_flags = 0; 1980 if (incl_opts) { 1981 ect = tcp_ecn_output_established(tp, &flags, 0, false); 1982 /* Make sure we have room. */ 1983 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1984 m->m_next = m_get(M_NOWAIT, MT_DATA); 1985 if (m->m_next) { 1986 optp = mtod(m->m_next, u_char *); 1987 optm = m->m_next; 1988 } else 1989 incl_opts = false; 1990 } else { 1991 optp = (u_char *) (nth + 1); 1992 optm = m; 1993 } 1994 } 1995 if (incl_opts) { 1996 /* Timestamps. */ 1997 if (tp->t_flags & TF_RCVD_TSTMP) { 1998 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1999 to.to_tsecr = tp->ts_recent; 2000 to.to_flags |= TOF_TS; 2001 } 2002 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2003 /* TCP-MD5 (RFC2385). */ 2004 if (tp->t_flags & TF_SIGNATURE) 2005 to.to_flags |= TOF_SIGNATURE; 2006 #endif 2007 /* Add the options. */ 2008 tlen += optlen = tcp_addoptions(&to, optp); 2009 2010 /* Update m_len in the correct mbuf. */ 2011 optm->m_len += optlen; 2012 } else 2013 optlen = 0; 2014 #ifdef INET6 2015 if (isipv6) { 2016 if (uh) { 2017 ulen = tlen - sizeof(struct ip6_hdr); 2018 uh->uh_ulen = htons(ulen); 2019 } 2020 ip6->ip6_flow = htonl(ect << 20); 2021 ip6->ip6_vfc = IPV6_VERSION; 2022 if (port) 2023 ip6->ip6_nxt = IPPROTO_UDP; 2024 else 2025 ip6->ip6_nxt = IPPROTO_TCP; 2026 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 2027 } 2028 #endif 2029 #if defined(INET) && defined(INET6) 2030 else 2031 #endif 2032 #ifdef INET 2033 { 2034 if (uh) { 2035 ulen = tlen - sizeof(struct ip); 2036 uh->uh_ulen = htons(ulen); 2037 } 2038 ip->ip_tos = ect; 2039 ip->ip_len = htons(tlen); 2040 ip->ip_ttl = V_ip_defttl; 2041 if (port) { 2042 ip->ip_p = IPPROTO_UDP; 2043 } else { 2044 ip->ip_p = IPPROTO_TCP; 2045 } 2046 if (V_path_mtu_discovery) 2047 ip->ip_off |= htons(IP_DF); 2048 } 2049 #endif 2050 m->m_pkthdr.len = tlen; 2051 m->m_pkthdr.rcvif = NULL; 2052 #ifdef MAC 2053 if (inp != NULL) { 2054 /* 2055 * Packet is associated with a socket, so allow the 2056 * label of the response to reflect the socket label. 2057 */ 2058 INP_LOCK_ASSERT(inp); 2059 mac_inpcb_create_mbuf(inp, m); 2060 } else { 2061 /* 2062 * Packet is not associated with a socket, so possibly 2063 * update the label in place. 2064 */ 2065 mac_netinet_tcp_reply(m); 2066 } 2067 #endif 2068 nth->th_seq = htonl(seq); 2069 nth->th_ack = htonl(ack); 2070 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2071 tcp_set_flags(nth, flags); 2072 if (tp != NULL) 2073 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2074 else 2075 nth->th_win = htons((u_short)win); 2076 nth->th_urp = 0; 2077 2078 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2079 if (to.to_flags & TOF_SIGNATURE) { 2080 if (!TCPMD5_ENABLED() || 2081 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2082 m_freem(m); 2083 return; 2084 } 2085 } 2086 #endif 2087 2088 #ifdef INET6 2089 if (isipv6) { 2090 if (port) { 2091 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2092 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2093 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2094 nth->th_sum = 0; 2095 } else { 2096 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2097 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2098 nth->th_sum = in6_cksum_pseudo(ip6, 2099 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2100 } 2101 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 2102 } 2103 #endif /* INET6 */ 2104 #if defined(INET6) && defined(INET) 2105 else 2106 #endif 2107 #ifdef INET 2108 { 2109 if (port) { 2110 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2111 htons(ulen + IPPROTO_UDP)); 2112 m->m_pkthdr.csum_flags = CSUM_UDP; 2113 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2114 nth->th_sum = 0; 2115 } else { 2116 m->m_pkthdr.csum_flags = CSUM_TCP; 2117 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2118 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2119 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2120 } 2121 } 2122 #endif /* INET */ 2123 #ifdef TCPDEBUG 2124 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2125 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2126 #endif 2127 TCP_PROBE3(debug__output, tp, th, m); 2128 if (flags & TH_RST) 2129 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2130 lgb = NULL; 2131 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2132 if (INP_WLOCKED(inp)) { 2133 union tcp_log_stackspecific log; 2134 struct timeval tv; 2135 2136 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2137 log.u_bbr.inhpts = inp->inp_in_hpts; 2138 log.u_bbr.flex8 = 4; 2139 log.u_bbr.pkts_out = tp->t_maxseg; 2140 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2141 log.u_bbr.delivered = 0; 2142 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2143 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2144 } else { 2145 /* 2146 * We can not log the packet, since we only own the 2147 * read lock, but a write lock is needed. The read lock 2148 * is not upgraded to a write lock, since only getting 2149 * the read lock was done intentionally to improve the 2150 * handling of SYN flooding attacks. 2151 * This happens only for pure SYN segments received in 2152 * the initial CLOSED state, or received in a more 2153 * advanced state than listen and the UDP encapsulation 2154 * port is unexpected. 2155 * The incoming SYN segments do not really belong to 2156 * the TCP connection and the handling does not change 2157 * the state of the TCP connection. Therefore, the 2158 * sending of the RST segments is not logged. Please 2159 * note that also the incoming SYN segments are not 2160 * logged. 2161 * 2162 * The following code ensures that the above description 2163 * is and stays correct. 2164 */ 2165 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2166 (tp->t_state == TCPS_CLOSED || 2167 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2168 ("%s: Logging of TCP segment with flags 0x%b and " 2169 "UDP encapsulation port %u skipped in state %s", 2170 __func__, thflags, PRINT_TH_FLAGS, 2171 ntohs(port), tcpstates[tp->t_state])); 2172 } 2173 } 2174 2175 if (flags & TH_ACK) 2176 TCPSTAT_INC(tcps_sndacks); 2177 else if (flags & (TH_SYN|TH_FIN|TH_RST)) 2178 TCPSTAT_INC(tcps_sndctrl); 2179 TCPSTAT_INC(tcps_sndtotal); 2180 2181 #ifdef INET6 2182 if (isipv6) { 2183 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2184 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2185 } 2186 #endif /* INET6 */ 2187 #if defined(INET) && defined(INET6) 2188 else 2189 #endif 2190 #ifdef INET 2191 { 2192 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2193 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2194 } 2195 #endif 2196 if (lgb != NULL) 2197 lgb->tlb_errno = output_ret; 2198 } 2199 2200 /* 2201 * Create a new TCP control block, making an 2202 * empty reassembly queue and hooking it to the argument 2203 * protocol control block. The `inp' parameter must have 2204 * come from the zone allocator set up in tcp_init(). 2205 */ 2206 struct tcpcb * 2207 tcp_newtcpcb(struct inpcb *inp) 2208 { 2209 struct tcpcb_mem *tm; 2210 struct tcpcb *tp; 2211 #ifdef INET6 2212 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2213 #endif /* INET6 */ 2214 2215 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2216 if (tm == NULL) 2217 return (NULL); 2218 tp = &tm->tcb; 2219 2220 /* Initialise cc_var struct for this tcpcb. */ 2221 tp->ccv = &tm->ccv; 2222 tp->ccv->type = IPPROTO_TCP; 2223 tp->ccv->ccvc.tcp = tp; 2224 rw_rlock(&tcp_function_lock); 2225 tp->t_fb = tcp_func_set_ptr; 2226 refcount_acquire(&tp->t_fb->tfb_refcnt); 2227 rw_runlock(&tcp_function_lock); 2228 /* 2229 * Use the current system default CC algorithm. 2230 */ 2231 cc_attach(tp, CC_DEFAULT_ALGO()); 2232 2233 /* 2234 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2235 * is called. 2236 */ 2237 in_pcbref(inp); /* Reference for tcpcb */ 2238 tp->t_inpcb = inp; 2239 2240 if (CC_ALGO(tp)->cb_init != NULL) 2241 if (CC_ALGO(tp)->cb_init(tp->ccv, NULL) > 0) { 2242 cc_detach(tp); 2243 if (tp->t_fb->tfb_tcp_fb_fini) 2244 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2245 in_pcbrele_wlocked(inp); 2246 refcount_release(&tp->t_fb->tfb_refcnt); 2247 uma_zfree(V_tcpcb_zone, tm); 2248 return (NULL); 2249 } 2250 2251 #ifdef TCP_HHOOK 2252 tp->osd = &tm->osd; 2253 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2254 if (tp->t_fb->tfb_tcp_fb_fini) 2255 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2256 in_pcbrele_wlocked(inp); 2257 refcount_release(&tp->t_fb->tfb_refcnt); 2258 uma_zfree(V_tcpcb_zone, tm); 2259 return (NULL); 2260 } 2261 #endif 2262 2263 tp->t_timers = &tm->tt; 2264 TAILQ_INIT(&tp->t_segq); 2265 tp->t_maxseg = 2266 #ifdef INET6 2267 isipv6 ? V_tcp_v6mssdflt : 2268 #endif /* INET6 */ 2269 V_tcp_mssdflt; 2270 2271 /* Set up our timeouts. */ 2272 callout_init(&tp->t_timers->tt_rexmt, 1); 2273 callout_init(&tp->t_timers->tt_persist, 1); 2274 callout_init(&tp->t_timers->tt_keep, 1); 2275 callout_init(&tp->t_timers->tt_2msl, 1); 2276 callout_init(&tp->t_timers->tt_delack, 1); 2277 2278 switch (V_tcp_do_rfc1323) { 2279 case 0: 2280 break; 2281 default: 2282 case 1: 2283 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2284 break; 2285 case 2: 2286 tp->t_flags = TF_REQ_SCALE; 2287 break; 2288 case 3: 2289 tp->t_flags = TF_REQ_TSTMP; 2290 break; 2291 } 2292 if (V_tcp_do_sack) 2293 tp->t_flags |= TF_SACK_PERMIT; 2294 TAILQ_INIT(&tp->snd_holes); 2295 2296 /* 2297 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2298 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2299 * reasonable initial retransmit time. 2300 */ 2301 tp->t_srtt = TCPTV_SRTTBASE; 2302 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2303 tp->t_rttmin = tcp_rexmit_min; 2304 tp->t_rxtcur = tcp_rexmit_initial; 2305 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2306 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2307 tp->t_rcvtime = ticks; 2308 /* 2309 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2310 * because the socket may be bound to an IPv6 wildcard address, 2311 * which may match an IPv4-mapped IPv6 address. 2312 */ 2313 inp->inp_ip_ttl = V_ip_defttl; 2314 inp->inp_ppcb = tp; 2315 #ifdef TCPHPTS 2316 /* 2317 * If using hpts lets drop a random number in so 2318 * not all new connections fall on the same CPU. 2319 */ 2320 inp->inp_hpts_cpu = hpts_random_cpu(inp); 2321 #endif 2322 #ifdef TCPPCAP 2323 /* 2324 * Init the TCP PCAP queues. 2325 */ 2326 tcp_pcap_tcpcb_init(tp); 2327 #endif 2328 #ifdef TCP_BLACKBOX 2329 /* Initialize the per-TCPCB log data. */ 2330 tcp_log_tcpcbinit(tp); 2331 #endif 2332 tp->t_pacing_rate = -1; 2333 if (tp->t_fb->tfb_tcp_fb_init) { 2334 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2335 refcount_release(&tp->t_fb->tfb_refcnt); 2336 in_pcbrele_wlocked(inp); 2337 uma_zfree(V_tcpcb_zone, tm); 2338 return (NULL); 2339 } 2340 } 2341 #ifdef STATS 2342 if (V_tcp_perconn_stats_enable == 1) 2343 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2344 #endif 2345 if (V_tcp_do_lrd) 2346 tp->t_flags |= TF_LRD; 2347 return (tp); /* XXX */ 2348 } 2349 2350 /* 2351 * Drop a TCP connection, reporting 2352 * the specified error. If connection is synchronized, 2353 * then send a RST to peer. 2354 */ 2355 struct tcpcb * 2356 tcp_drop(struct tcpcb *tp, int errno) 2357 { 2358 struct socket *so = tptosocket(tp); 2359 2360 NET_EPOCH_ASSERT(); 2361 INP_WLOCK_ASSERT(tptoinpcb(tp)); 2362 2363 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2364 tcp_state_change(tp, TCPS_CLOSED); 2365 /* Don't use tcp_output() here due to possible recursion. */ 2366 (void)tcp_output_nodrop(tp); 2367 TCPSTAT_INC(tcps_drops); 2368 } else 2369 TCPSTAT_INC(tcps_conndrops); 2370 if (errno == ETIMEDOUT && tp->t_softerror) 2371 errno = tp->t_softerror; 2372 so->so_error = errno; 2373 return (tcp_close(tp)); 2374 } 2375 2376 void 2377 tcp_discardcb(struct tcpcb *tp) 2378 { 2379 struct inpcb *inp = tptoinpcb(tp); 2380 2381 INP_WLOCK_ASSERT(inp); 2382 2383 /* 2384 * Make sure that all of our timers are stopped before we delete the 2385 * PCB. 2386 * 2387 * If stopping a timer fails, we schedule a discard function in same 2388 * callout, and the last discard function called will take care of 2389 * deleting the tcpcb. 2390 */ 2391 tp->t_timers->tt_draincnt = 0; 2392 tcp_timer_stop(tp, TT_REXMT); 2393 tcp_timer_stop(tp, TT_PERSIST); 2394 tcp_timer_stop(tp, TT_KEEP); 2395 tcp_timer_stop(tp, TT_2MSL); 2396 tcp_timer_stop(tp, TT_DELACK); 2397 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2398 /* 2399 * Call the stop-all function of the methods, 2400 * this function should call the tcp_timer_stop() 2401 * method with each of the function specific timeouts. 2402 * That stop will be called via the tfb_tcp_timer_stop() 2403 * which should use the async drain function of the 2404 * callout system (see tcp_var.h). 2405 */ 2406 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2407 } 2408 2409 /* free the reassembly queue, if any */ 2410 tcp_reass_flush(tp); 2411 2412 #ifdef TCP_OFFLOAD 2413 /* Disconnect offload device, if any. */ 2414 if (tp->t_flags & TF_TOE) 2415 tcp_offload_detach(tp); 2416 #endif 2417 2418 tcp_free_sackholes(tp); 2419 2420 #ifdef TCPPCAP 2421 /* Free the TCP PCAP queues. */ 2422 tcp_pcap_drain(&(tp->t_inpkts)); 2423 tcp_pcap_drain(&(tp->t_outpkts)); 2424 #endif 2425 2426 /* Allow the CC algorithm to clean up after itself. */ 2427 if (CC_ALGO(tp)->cb_destroy != NULL) 2428 CC_ALGO(tp)->cb_destroy(tp->ccv); 2429 CC_DATA(tp) = NULL; 2430 /* Detach from the CC algorithm */ 2431 cc_detach(tp); 2432 2433 #ifdef TCP_HHOOK 2434 khelp_destroy_osd(tp->osd); 2435 #endif 2436 #ifdef STATS 2437 stats_blob_destroy(tp->t_stats); 2438 #endif 2439 2440 CC_ALGO(tp) = NULL; 2441 inp->inp_ppcb = NULL; 2442 if (tp->t_timers->tt_draincnt == 0) { 2443 bool released __diagused; 2444 2445 released = tcp_freecb(tp); 2446 KASSERT(!released, ("%s: inp %p should not have been released " 2447 "here", __func__, inp)); 2448 } 2449 } 2450 2451 bool 2452 tcp_freecb(struct tcpcb *tp) 2453 { 2454 struct inpcb *inp = tptoinpcb(tp); 2455 struct socket *so = tptosocket(tp); 2456 #ifdef INET6 2457 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2458 #endif 2459 2460 INP_WLOCK_ASSERT(inp); 2461 MPASS(tp->t_timers->tt_draincnt == 0); 2462 2463 /* We own the last reference on tcpcb, let's free it. */ 2464 #ifdef TCP_BLACKBOX 2465 tcp_log_tcpcbfini(tp); 2466 #endif 2467 TCPSTATES_DEC(tp->t_state); 2468 if (tp->t_fb->tfb_tcp_fb_fini) 2469 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2470 2471 /* 2472 * If we got enough samples through the srtt filter, 2473 * save the rtt and rttvar in the routing entry. 2474 * 'Enough' is arbitrarily defined as 4 rtt samples. 2475 * 4 samples is enough for the srtt filter to converge 2476 * to within enough % of the correct value; fewer samples 2477 * and we could save a bogus rtt. The danger is not high 2478 * as tcp quickly recovers from everything. 2479 * XXX: Works very well but needs some more statistics! 2480 * 2481 * XXXRRS: Updating must be after the stack fini() since 2482 * that may be converting some internal representation of 2483 * say srtt etc into the general one used by other stacks. 2484 * Lets also at least protect against the so being NULL 2485 * as RW stated below. 2486 */ 2487 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2488 struct hc_metrics_lite metrics; 2489 uint32_t ssthresh; 2490 2491 bzero(&metrics, sizeof(metrics)); 2492 /* 2493 * Update the ssthresh always when the conditions below 2494 * are satisfied. This gives us better new start value 2495 * for the congestion avoidance for new connections. 2496 * ssthresh is only set if packet loss occurred on a session. 2497 * 2498 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2499 * being torn down. Ideally this code would not use 'so'. 2500 */ 2501 ssthresh = tp->snd_ssthresh; 2502 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2503 /* 2504 * convert the limit from user data bytes to 2505 * packets then to packet data bytes. 2506 */ 2507 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2508 if (ssthresh < 2) 2509 ssthresh = 2; 2510 ssthresh *= (tp->t_maxseg + 2511 #ifdef INET6 2512 (isipv6 ? sizeof (struct ip6_hdr) + 2513 sizeof (struct tcphdr) : 2514 #endif 2515 sizeof (struct tcpiphdr) 2516 #ifdef INET6 2517 ) 2518 #endif 2519 ); 2520 } else 2521 ssthresh = 0; 2522 metrics.rmx_ssthresh = ssthresh; 2523 2524 metrics.rmx_rtt = tp->t_srtt; 2525 metrics.rmx_rttvar = tp->t_rttvar; 2526 metrics.rmx_cwnd = tp->snd_cwnd; 2527 metrics.rmx_sendpipe = 0; 2528 metrics.rmx_recvpipe = 0; 2529 2530 tcp_hc_update(&inp->inp_inc, &metrics); 2531 } 2532 2533 refcount_release(&tp->t_fb->tfb_refcnt); 2534 uma_zfree(V_tcpcb_zone, tp); 2535 2536 return (in_pcbrele_wlocked(inp)); 2537 } 2538 2539 /* 2540 * Attempt to close a TCP control block, marking it as dropped, and freeing 2541 * the socket if we hold the only reference. 2542 */ 2543 struct tcpcb * 2544 tcp_close(struct tcpcb *tp) 2545 { 2546 struct inpcb *inp = tptoinpcb(tp); 2547 struct socket *so = tptosocket(tp); 2548 2549 INP_WLOCK_ASSERT(inp); 2550 2551 #ifdef TCP_OFFLOAD 2552 if (tp->t_state == TCPS_LISTEN) 2553 tcp_offload_listen_stop(tp); 2554 #endif 2555 /* 2556 * This releases the TFO pending counter resource for TFO listen 2557 * sockets as well as passively-created TFO sockets that transition 2558 * from SYN_RECEIVED to CLOSED. 2559 */ 2560 if (tp->t_tfo_pending) { 2561 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2562 tp->t_tfo_pending = NULL; 2563 } 2564 #ifdef TCPHPTS 2565 tcp_hpts_remove(inp); 2566 #endif 2567 in_pcbdrop(inp); 2568 TCPSTAT_INC(tcps_closed); 2569 if (tp->t_state != TCPS_CLOSED) 2570 tcp_state_change(tp, TCPS_CLOSED); 2571 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2572 soisdisconnected(so); 2573 if (inp->inp_flags & INP_SOCKREF) { 2574 inp->inp_flags &= ~INP_SOCKREF; 2575 INP_WUNLOCK(inp); 2576 sorele(so); 2577 return (NULL); 2578 } 2579 return (tp); 2580 } 2581 2582 /* 2583 * Notify a tcp user of an asynchronous error; 2584 * store error as soft error, but wake up user 2585 * (for now, won't do anything until can select for soft error). 2586 * 2587 * Do not wake up user since there currently is no mechanism for 2588 * reporting soft errors (yet - a kqueue filter may be added). 2589 */ 2590 static struct inpcb * 2591 tcp_notify(struct inpcb *inp, int error) 2592 { 2593 struct tcpcb *tp; 2594 2595 INP_WLOCK_ASSERT(inp); 2596 2597 tp = intotcpcb(inp); 2598 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2599 2600 /* 2601 * Ignore some errors if we are hooked up. 2602 * If connection hasn't completed, has retransmitted several times, 2603 * and receives a second error, give up now. This is better 2604 * than waiting a long time to establish a connection that 2605 * can never complete. 2606 */ 2607 if (tp->t_state == TCPS_ESTABLISHED && 2608 (error == EHOSTUNREACH || error == ENETUNREACH || 2609 error == EHOSTDOWN)) { 2610 if (inp->inp_route.ro_nh) { 2611 NH_FREE(inp->inp_route.ro_nh); 2612 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2613 } 2614 return (inp); 2615 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2616 tp->t_softerror) { 2617 tp = tcp_drop(tp, error); 2618 if (tp != NULL) 2619 return (inp); 2620 else 2621 return (NULL); 2622 } else { 2623 tp->t_softerror = error; 2624 return (inp); 2625 } 2626 #if 0 2627 wakeup( &so->so_timeo); 2628 sorwakeup(so); 2629 sowwakeup(so); 2630 #endif 2631 } 2632 2633 static int 2634 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2635 { 2636 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2637 INPLOOKUP_RLOCKPCB); 2638 struct xinpgen xig; 2639 struct inpcb *inp; 2640 int error; 2641 2642 if (req->newptr != NULL) 2643 return (EPERM); 2644 2645 if (req->oldptr == NULL) { 2646 int n; 2647 2648 n = V_tcbinfo.ipi_count + 2649 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2650 n += imax(n / 8, 10); 2651 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2652 return (0); 2653 } 2654 2655 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2656 return (error); 2657 2658 bzero(&xig, sizeof(xig)); 2659 xig.xig_len = sizeof xig; 2660 xig.xig_count = V_tcbinfo.ipi_count + 2661 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2662 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2663 xig.xig_sogen = so_gencnt; 2664 error = SYSCTL_OUT(req, &xig, sizeof xig); 2665 if (error) 2666 return (error); 2667 2668 error = syncache_pcblist(req); 2669 if (error) 2670 return (error); 2671 2672 while ((inp = inp_next(&inpi)) != NULL) { 2673 if (inp->inp_gencnt <= xig.xig_gen && 2674 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 2675 struct xtcpcb xt; 2676 2677 tcp_inptoxtp(inp, &xt); 2678 error = SYSCTL_OUT(req, &xt, sizeof xt); 2679 if (error) { 2680 INP_RUNLOCK(inp); 2681 break; 2682 } else 2683 continue; 2684 } 2685 } 2686 2687 if (!error) { 2688 /* 2689 * Give the user an updated idea of our state. 2690 * If the generation differs from what we told 2691 * her before, she knows that something happened 2692 * while we were processing this request, and it 2693 * might be necessary to retry. 2694 */ 2695 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2696 xig.xig_sogen = so_gencnt; 2697 xig.xig_count = V_tcbinfo.ipi_count + 2698 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2699 error = SYSCTL_OUT(req, &xig, sizeof xig); 2700 } 2701 2702 return (error); 2703 } 2704 2705 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2706 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2707 NULL, 0, tcp_pcblist, "S,xtcpcb", 2708 "List of active TCP connections"); 2709 2710 #ifdef INET 2711 static int 2712 tcp_getcred(SYSCTL_HANDLER_ARGS) 2713 { 2714 struct xucred xuc; 2715 struct sockaddr_in addrs[2]; 2716 struct epoch_tracker et; 2717 struct inpcb *inp; 2718 int error; 2719 2720 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2721 if (error) 2722 return (error); 2723 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2724 if (error) 2725 return (error); 2726 NET_EPOCH_ENTER(et); 2727 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2728 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2729 NET_EPOCH_EXIT(et); 2730 if (inp != NULL) { 2731 if (error == 0) 2732 error = cr_canseeinpcb(req->td->td_ucred, inp); 2733 if (error == 0) 2734 cru2x(inp->inp_cred, &xuc); 2735 INP_RUNLOCK(inp); 2736 } else 2737 error = ENOENT; 2738 if (error == 0) 2739 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2740 return (error); 2741 } 2742 2743 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2744 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2745 0, 0, tcp_getcred, "S,xucred", 2746 "Get the xucred of a TCP connection"); 2747 #endif /* INET */ 2748 2749 #ifdef INET6 2750 static int 2751 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2752 { 2753 struct epoch_tracker et; 2754 struct xucred xuc; 2755 struct sockaddr_in6 addrs[2]; 2756 struct inpcb *inp; 2757 int error; 2758 #ifdef INET 2759 int mapped = 0; 2760 #endif 2761 2762 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2763 if (error) 2764 return (error); 2765 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2766 if (error) 2767 return (error); 2768 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2769 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2770 return (error); 2771 } 2772 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2773 #ifdef INET 2774 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2775 mapped = 1; 2776 else 2777 #endif 2778 return (EINVAL); 2779 } 2780 2781 NET_EPOCH_ENTER(et); 2782 #ifdef INET 2783 if (mapped == 1) 2784 inp = in_pcblookup(&V_tcbinfo, 2785 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2786 addrs[1].sin6_port, 2787 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2788 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2789 else 2790 #endif 2791 inp = in6_pcblookup(&V_tcbinfo, 2792 &addrs[1].sin6_addr, addrs[1].sin6_port, 2793 &addrs[0].sin6_addr, addrs[0].sin6_port, 2794 INPLOOKUP_RLOCKPCB, NULL); 2795 NET_EPOCH_EXIT(et); 2796 if (inp != NULL) { 2797 if (error == 0) 2798 error = cr_canseeinpcb(req->td->td_ucred, inp); 2799 if (error == 0) 2800 cru2x(inp->inp_cred, &xuc); 2801 INP_RUNLOCK(inp); 2802 } else 2803 error = ENOENT; 2804 if (error == 0) 2805 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2806 return (error); 2807 } 2808 2809 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2810 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2811 0, 0, tcp6_getcred, "S,xucred", 2812 "Get the xucred of a TCP6 connection"); 2813 #endif /* INET6 */ 2814 2815 #ifdef INET 2816 /* Path MTU to try next when a fragmentation-needed message is received. */ 2817 static inline int 2818 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2819 { 2820 int mtu = ntohs(icp->icmp_nextmtu); 2821 2822 /* If no alternative MTU was proposed, try the next smaller one. */ 2823 if (!mtu) 2824 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2825 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2826 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2827 2828 return (mtu); 2829 } 2830 2831 static void 2832 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port) 2833 { 2834 struct ip *ip; 2835 struct tcphdr *th; 2836 struct inpcb *inp; 2837 struct tcpcb *tp; 2838 struct inpcb *(*notify)(struct inpcb *, int); 2839 struct in_conninfo inc; 2840 tcp_seq icmp_tcp_seq; 2841 int errno, mtu; 2842 2843 errno = icmp_errmap(icp); 2844 switch (errno) { 2845 case 0: 2846 return; 2847 case EMSGSIZE: 2848 notify = tcp_mtudisc_notify; 2849 break; 2850 case ECONNREFUSED: 2851 if (V_icmp_may_rst) 2852 notify = tcp_drop_syn_sent; 2853 else 2854 notify = tcp_notify; 2855 break; 2856 case EHOSTUNREACH: 2857 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED) 2858 notify = tcp_drop_syn_sent; 2859 else 2860 notify = tcp_notify; 2861 break; 2862 default: 2863 notify = tcp_notify; 2864 } 2865 2866 ip = &icp->icmp_ip; 2867 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2868 icmp_tcp_seq = th->th_seq; 2869 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src, 2870 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2871 if (inp != NULL) { 2872 tp = intotcpcb(inp); 2873 #ifdef TCP_OFFLOAD 2874 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2875 /* 2876 * MTU discovery for offloaded connections. Let 2877 * the TOE driver verify seq# and process it. 2878 */ 2879 mtu = tcp_next_pmtu(icp, ip); 2880 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2881 goto out; 2882 } 2883 #endif 2884 if (tp->t_port != port) 2885 goto out; 2886 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2887 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2888 if (errno == EMSGSIZE) { 2889 /* 2890 * MTU discovery: we got a needfrag and 2891 * will potentially try a lower MTU. 2892 */ 2893 mtu = tcp_next_pmtu(icp, ip); 2894 2895 /* 2896 * Only process the offered MTU if it 2897 * is smaller than the current one. 2898 */ 2899 if (mtu < tp->t_maxseg + 2900 sizeof(struct tcpiphdr)) { 2901 bzero(&inc, sizeof(inc)); 2902 inc.inc_faddr = ip->ip_dst; 2903 inc.inc_fibnum = 2904 inp->inp_inc.inc_fibnum; 2905 tcp_hc_updatemtu(&inc, mtu); 2906 inp = tcp_mtudisc(inp, mtu); 2907 } 2908 } else 2909 inp = (*notify)(inp, errno); 2910 } 2911 } else { 2912 bzero(&inc, sizeof(inc)); 2913 inc.inc_fport = th->th_dport; 2914 inc.inc_lport = th->th_sport; 2915 inc.inc_faddr = ip->ip_dst; 2916 inc.inc_laddr = ip->ip_src; 2917 syncache_unreach(&inc, icmp_tcp_seq, port); 2918 } 2919 out: 2920 if (inp != NULL) 2921 INP_WUNLOCK(inp); 2922 } 2923 2924 static void 2925 tcp_ctlinput(struct icmp *icmp) 2926 { 2927 tcp_ctlinput_with_port(icmp, htons(0)); 2928 } 2929 2930 static void 2931 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param) 2932 { 2933 /* Its a tunneled TCP over UDP icmp */ 2934 struct icmp *icmp = param.icmp; 2935 struct ip *outer_ip, *inner_ip; 2936 struct udphdr *udp; 2937 struct tcphdr *th, ttemp; 2938 int i_hlen, o_len; 2939 uint16_t port; 2940 2941 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2942 inner_ip = &icmp->icmp_ip; 2943 i_hlen = inner_ip->ip_hl << 2; 2944 o_len = ntohs(outer_ip->ip_len); 2945 if (o_len < 2946 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2947 /* Not enough data present */ 2948 return; 2949 } 2950 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2951 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2952 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2953 return; 2954 } 2955 port = udp->uh_dport; 2956 th = (struct tcphdr *)(udp + 1); 2957 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2958 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2959 /* Now adjust down the size of the outer IP header */ 2960 o_len -= sizeof(struct udphdr); 2961 outer_ip->ip_len = htons(o_len); 2962 /* Now call in to the normal handling code */ 2963 tcp_ctlinput_with_port(icmp, port); 2964 } 2965 #endif /* INET */ 2966 2967 #ifdef INET6 2968 static inline int 2969 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2970 { 2971 int mtu = ntohl(icmp6->icmp6_mtu); 2972 2973 /* 2974 * If no alternative MTU was proposed, or the proposed MTU was too 2975 * small, set to the min. 2976 */ 2977 if (mtu < IPV6_MMTU) 2978 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2979 return (mtu); 2980 } 2981 2982 static void 2983 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port) 2984 { 2985 struct in6_addr *dst; 2986 struct inpcb *(*notify)(struct inpcb *, int); 2987 struct ip6_hdr *ip6; 2988 struct mbuf *m; 2989 struct inpcb *inp; 2990 struct tcpcb *tp; 2991 struct icmp6_hdr *icmp6; 2992 struct in_conninfo inc; 2993 struct tcp_ports { 2994 uint16_t th_sport; 2995 uint16_t th_dport; 2996 } t_ports; 2997 tcp_seq icmp_tcp_seq; 2998 unsigned int mtu; 2999 unsigned int off; 3000 int errno; 3001 3002 icmp6 = ip6cp->ip6c_icmp6; 3003 m = ip6cp->ip6c_m; 3004 ip6 = ip6cp->ip6c_ip6; 3005 off = ip6cp->ip6c_off; 3006 dst = &ip6cp->ip6c_finaldst->sin6_addr; 3007 3008 errno = icmp6_errmap(icmp6); 3009 switch (errno) { 3010 case 0: 3011 return; 3012 case EMSGSIZE: 3013 notify = tcp_mtudisc_notify; 3014 break; 3015 case ECONNREFUSED: 3016 if (V_icmp_may_rst) 3017 notify = tcp_drop_syn_sent; 3018 else 3019 notify = tcp_notify; 3020 break; 3021 case EHOSTUNREACH: 3022 /* 3023 * There are only four ICMPs that may reset connection: 3024 * - administratively prohibited 3025 * - port unreachable 3026 * - time exceeded in transit 3027 * - unknown next header 3028 */ 3029 if (V_icmp_may_rst && 3030 ((icmp6->icmp6_type == ICMP6_DST_UNREACH && 3031 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN || 3032 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) || 3033 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED && 3034 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) || 3035 (icmp6->icmp6_type == ICMP6_PARAM_PROB && 3036 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER))) 3037 notify = tcp_drop_syn_sent; 3038 else 3039 notify = tcp_notify; 3040 break; 3041 default: 3042 notify = tcp_notify; 3043 } 3044 3045 /* Check if we can safely get the ports from the tcp hdr */ 3046 if (m == NULL || 3047 (m->m_pkthdr.len < 3048 (int32_t) (off + sizeof(struct tcp_ports)))) { 3049 return; 3050 } 3051 bzero(&t_ports, sizeof(struct tcp_ports)); 3052 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3053 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3054 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3055 off += sizeof(struct tcp_ports); 3056 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3057 goto out; 3058 } 3059 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3060 if (inp != NULL) { 3061 tp = intotcpcb(inp); 3062 #ifdef TCP_OFFLOAD 3063 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 3064 /* MTU discovery for offloaded connections. */ 3065 mtu = tcp6_next_pmtu(icmp6); 3066 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3067 goto out; 3068 } 3069 #endif 3070 if (tp->t_port != port) 3071 goto out; 3072 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3073 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3074 if (errno == EMSGSIZE) { 3075 /* 3076 * MTU discovery: 3077 * If we got a needfrag set the MTU 3078 * in the route to the suggested new 3079 * value (if given) and then notify. 3080 */ 3081 mtu = tcp6_next_pmtu(icmp6); 3082 3083 bzero(&inc, sizeof(inc)); 3084 inc.inc_fibnum = M_GETFIB(m); 3085 inc.inc_flags |= INC_ISIPV6; 3086 inc.inc6_faddr = *dst; 3087 if (in6_setscope(&inc.inc6_faddr, 3088 m->m_pkthdr.rcvif, NULL)) 3089 goto out; 3090 /* 3091 * Only process the offered MTU if it 3092 * is smaller than the current one. 3093 */ 3094 if (mtu < tp->t_maxseg + 3095 sizeof (struct tcphdr) + 3096 sizeof (struct ip6_hdr)) { 3097 tcp_hc_updatemtu(&inc, mtu); 3098 tcp_mtudisc(inp, mtu); 3099 ICMP6STAT_INC(icp6s_pmtuchg); 3100 } 3101 } else 3102 inp = (*notify)(inp, errno); 3103 } 3104 } else { 3105 bzero(&inc, sizeof(inc)); 3106 inc.inc_fibnum = M_GETFIB(m); 3107 inc.inc_flags |= INC_ISIPV6; 3108 inc.inc_fport = t_ports.th_dport; 3109 inc.inc_lport = t_ports.th_sport; 3110 inc.inc6_faddr = *dst; 3111 inc.inc6_laddr = ip6->ip6_src; 3112 syncache_unreach(&inc, icmp_tcp_seq, port); 3113 } 3114 out: 3115 if (inp != NULL) 3116 INP_WUNLOCK(inp); 3117 } 3118 3119 static void 3120 tcp6_ctlinput(struct ip6ctlparam *ctl) 3121 { 3122 tcp6_ctlinput_with_port(ctl, htons(0)); 3123 } 3124 3125 static void 3126 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param) 3127 { 3128 struct ip6ctlparam *ip6cp = param.ip6cp; 3129 struct mbuf *m; 3130 struct udphdr *udp; 3131 uint16_t port; 3132 3133 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3134 if (m == NULL) { 3135 return; 3136 } 3137 udp = mtod(m, struct udphdr *); 3138 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3139 return; 3140 } 3141 port = udp->uh_dport; 3142 m_adj(m, sizeof(struct udphdr)); 3143 if ((m->m_flags & M_PKTHDR) == 0) { 3144 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3145 } 3146 /* Now call in to the normal handling code */ 3147 tcp6_ctlinput_with_port(ip6cp, port); 3148 } 3149 3150 #endif /* INET6 */ 3151 3152 static uint32_t 3153 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3154 { 3155 SIPHASH_CTX ctx; 3156 uint32_t hash[2]; 3157 3158 KASSERT(len >= SIPHASH_KEY_LENGTH, 3159 ("%s: keylen %u too short ", __func__, len)); 3160 SipHash24_Init(&ctx); 3161 SipHash_SetKey(&ctx, (uint8_t *)key); 3162 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3163 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3164 switch (inc->inc_flags & INC_ISIPV6) { 3165 #ifdef INET 3166 case 0: 3167 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3168 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3169 break; 3170 #endif 3171 #ifdef INET6 3172 case INC_ISIPV6: 3173 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3174 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3175 break; 3176 #endif 3177 } 3178 SipHash_Final((uint8_t *)hash, &ctx); 3179 3180 return (hash[0] ^ hash[1]); 3181 } 3182 3183 uint32_t 3184 tcp_new_ts_offset(struct in_conninfo *inc) 3185 { 3186 struct in_conninfo inc_store, *local_inc; 3187 3188 if (!V_tcp_ts_offset_per_conn) { 3189 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3190 inc_store.inc_lport = 0; 3191 inc_store.inc_fport = 0; 3192 local_inc = &inc_store; 3193 } else { 3194 local_inc = inc; 3195 } 3196 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3197 sizeof(V_ts_offset_secret))); 3198 } 3199 3200 /* 3201 * Following is where TCP initial sequence number generation occurs. 3202 * 3203 * There are two places where we must use initial sequence numbers: 3204 * 1. In SYN-ACK packets. 3205 * 2. In SYN packets. 3206 * 3207 * All ISNs for SYN-ACK packets are generated by the syncache. See 3208 * tcp_syncache.c for details. 3209 * 3210 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3211 * depends on this property. In addition, these ISNs should be 3212 * unguessable so as to prevent connection hijacking. To satisfy 3213 * the requirements of this situation, the algorithm outlined in 3214 * RFC 1948 is used, with only small modifications. 3215 * 3216 * Implementation details: 3217 * 3218 * Time is based off the system timer, and is corrected so that it 3219 * increases by one megabyte per second. This allows for proper 3220 * recycling on high speed LANs while still leaving over an hour 3221 * before rollover. 3222 * 3223 * As reading the *exact* system time is too expensive to be done 3224 * whenever setting up a TCP connection, we increment the time 3225 * offset in two ways. First, a small random positive increment 3226 * is added to isn_offset for each connection that is set up. 3227 * Second, the function tcp_isn_tick fires once per clock tick 3228 * and increments isn_offset as necessary so that sequence numbers 3229 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3230 * random positive increments serve only to ensure that the same 3231 * exact sequence number is never sent out twice (as could otherwise 3232 * happen when a port is recycled in less than the system tick 3233 * interval.) 3234 * 3235 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3236 * between seeding of isn_secret. This is normally set to zero, 3237 * as reseeding should not be necessary. 3238 * 3239 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3240 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3241 * general, this means holding an exclusive (write) lock. 3242 */ 3243 3244 #define ISN_BYTES_PER_SECOND 1048576 3245 #define ISN_STATIC_INCREMENT 4096 3246 #define ISN_RANDOM_INCREMENT (4096 - 1) 3247 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3248 3249 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3250 VNET_DEFINE_STATIC(int, isn_last); 3251 VNET_DEFINE_STATIC(int, isn_last_reseed); 3252 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3253 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3254 3255 #define V_isn_secret VNET(isn_secret) 3256 #define V_isn_last VNET(isn_last) 3257 #define V_isn_last_reseed VNET(isn_last_reseed) 3258 #define V_isn_offset VNET(isn_offset) 3259 #define V_isn_offset_old VNET(isn_offset_old) 3260 3261 tcp_seq 3262 tcp_new_isn(struct in_conninfo *inc) 3263 { 3264 tcp_seq new_isn; 3265 u_int32_t projected_offset; 3266 3267 ISN_LOCK(); 3268 /* Seed if this is the first use, reseed if requested. */ 3269 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3270 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3271 < (u_int)ticks))) { 3272 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3273 V_isn_last_reseed = ticks; 3274 } 3275 3276 /* Compute the hash and return the ISN. */ 3277 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3278 sizeof(V_isn_secret)); 3279 V_isn_offset += ISN_STATIC_INCREMENT + 3280 (arc4random() & ISN_RANDOM_INCREMENT); 3281 if (ticks != V_isn_last) { 3282 projected_offset = V_isn_offset_old + 3283 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3284 if (SEQ_GT(projected_offset, V_isn_offset)) 3285 V_isn_offset = projected_offset; 3286 V_isn_offset_old = V_isn_offset; 3287 V_isn_last = ticks; 3288 } 3289 new_isn += V_isn_offset; 3290 ISN_UNLOCK(); 3291 return (new_isn); 3292 } 3293 3294 /* 3295 * When a specific ICMP unreachable message is received and the 3296 * connection state is SYN-SENT, drop the connection. This behavior 3297 * is controlled by the icmp_may_rst sysctl. 3298 */ 3299 static struct inpcb * 3300 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3301 { 3302 struct tcpcb *tp; 3303 3304 NET_EPOCH_ASSERT(); 3305 INP_WLOCK_ASSERT(inp); 3306 3307 tp = intotcpcb(inp); 3308 if (tp->t_state != TCPS_SYN_SENT) 3309 return (inp); 3310 3311 if (IS_FASTOPEN(tp->t_flags)) 3312 tcp_fastopen_disable_path(tp); 3313 3314 tp = tcp_drop(tp, errno); 3315 if (tp != NULL) 3316 return (inp); 3317 else 3318 return (NULL); 3319 } 3320 3321 /* 3322 * When `need fragmentation' ICMP is received, update our idea of the MSS 3323 * based on the new value. Also nudge TCP to send something, since we 3324 * know the packet we just sent was dropped. 3325 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3326 */ 3327 static struct inpcb * 3328 tcp_mtudisc_notify(struct inpcb *inp, int error) 3329 { 3330 3331 return (tcp_mtudisc(inp, -1)); 3332 } 3333 3334 static struct inpcb * 3335 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3336 { 3337 struct tcpcb *tp; 3338 struct socket *so; 3339 3340 INP_WLOCK_ASSERT(inp); 3341 3342 tp = intotcpcb(inp); 3343 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3344 3345 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3346 3347 so = inp->inp_socket; 3348 SOCKBUF_LOCK(&so->so_snd); 3349 /* If the mss is larger than the socket buffer, decrease the mss. */ 3350 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3351 tp->t_maxseg = so->so_snd.sb_hiwat; 3352 SOCKBUF_UNLOCK(&so->so_snd); 3353 3354 TCPSTAT_INC(tcps_mturesent); 3355 tp->t_rtttime = 0; 3356 tp->snd_nxt = tp->snd_una; 3357 tcp_free_sackholes(tp); 3358 tp->snd_recover = tp->snd_max; 3359 if (tp->t_flags & TF_SACK_PERMIT) 3360 EXIT_FASTRECOVERY(tp->t_flags); 3361 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3362 /* 3363 * Conceptually the snd_nxt setting 3364 * and freeing sack holes should 3365 * be done by the default stacks 3366 * own tfb_tcp_mtu_chg(). 3367 */ 3368 tp->t_fb->tfb_tcp_mtu_chg(tp); 3369 } 3370 if (tcp_output(tp) < 0) 3371 return (NULL); 3372 else 3373 return (inp); 3374 } 3375 3376 #ifdef INET 3377 /* 3378 * Look-up the routing entry to the peer of this inpcb. If no route 3379 * is found and it cannot be allocated, then return 0. This routine 3380 * is called by TCP routines that access the rmx structure and by 3381 * tcp_mss_update to get the peer/interface MTU. 3382 */ 3383 uint32_t 3384 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3385 { 3386 struct nhop_object *nh; 3387 struct ifnet *ifp; 3388 uint32_t maxmtu = 0; 3389 3390 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3391 3392 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3393 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3394 if (nh == NULL) 3395 return (0); 3396 3397 ifp = nh->nh_ifp; 3398 maxmtu = nh->nh_mtu; 3399 3400 /* Report additional interface capabilities. */ 3401 if (cap != NULL) { 3402 if (ifp->if_capenable & IFCAP_TSO4 && 3403 ifp->if_hwassist & CSUM_TSO) { 3404 cap->ifcap |= CSUM_TSO; 3405 cap->tsomax = ifp->if_hw_tsomax; 3406 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3407 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3408 } 3409 } 3410 } 3411 return (maxmtu); 3412 } 3413 #endif /* INET */ 3414 3415 #ifdef INET6 3416 uint32_t 3417 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3418 { 3419 struct nhop_object *nh; 3420 struct in6_addr dst6; 3421 uint32_t scopeid; 3422 struct ifnet *ifp; 3423 uint32_t maxmtu = 0; 3424 3425 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3426 3427 if (inc->inc_flags & INC_IPV6MINMTU) 3428 return (IPV6_MMTU); 3429 3430 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3431 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3432 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3433 if (nh == NULL) 3434 return (0); 3435 3436 ifp = nh->nh_ifp; 3437 maxmtu = nh->nh_mtu; 3438 3439 /* Report additional interface capabilities. */ 3440 if (cap != NULL) { 3441 if (ifp->if_capenable & IFCAP_TSO6 && 3442 ifp->if_hwassist & CSUM_TSO) { 3443 cap->ifcap |= CSUM_TSO; 3444 cap->tsomax = ifp->if_hw_tsomax; 3445 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3446 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3447 } 3448 } 3449 } 3450 3451 return (maxmtu); 3452 } 3453 3454 /* 3455 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3456 * 3457 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3458 * The right place to do that is ip6_setpktopt() that has just been 3459 * executed. By the way it just filled ip6po_minmtu for us. 3460 */ 3461 void 3462 tcp6_use_min_mtu(struct tcpcb *tp) 3463 { 3464 struct inpcb *inp = tptoinpcb(tp); 3465 3466 INP_WLOCK_ASSERT(inp); 3467 /* 3468 * In case of the IPV6_USE_MIN_MTU socket 3469 * option, the INC_IPV6MINMTU flag to announce 3470 * a corresponding MSS during the initial 3471 * handshake. If the TCP connection is not in 3472 * the front states, just reduce the MSS being 3473 * used. This avoids the sending of TCP 3474 * segments which will be fragmented at the 3475 * IPv6 layer. 3476 */ 3477 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3478 if ((tp->t_state >= TCPS_SYN_SENT) && 3479 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3480 struct ip6_pktopts *opt; 3481 3482 opt = inp->in6p_outputopts; 3483 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3484 tp->t_maxseg > TCP6_MSS) 3485 tp->t_maxseg = TCP6_MSS; 3486 } 3487 } 3488 #endif /* INET6 */ 3489 3490 /* 3491 * Calculate effective SMSS per RFC5681 definition for a given TCP 3492 * connection at its current state, taking into account SACK and etc. 3493 */ 3494 u_int 3495 tcp_maxseg(const struct tcpcb *tp) 3496 { 3497 u_int optlen; 3498 3499 if (tp->t_flags & TF_NOOPT) 3500 return (tp->t_maxseg); 3501 3502 /* 3503 * Here we have a simplified code from tcp_addoptions(), 3504 * without a proper loop, and having most of paddings hardcoded. 3505 * We might make mistakes with padding here in some edge cases, 3506 * but this is harmless, since result of tcp_maxseg() is used 3507 * only in cwnd and ssthresh estimations. 3508 */ 3509 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3510 if (tp->t_flags & TF_RCVD_TSTMP) 3511 optlen = TCPOLEN_TSTAMP_APPA; 3512 else 3513 optlen = 0; 3514 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3515 if (tp->t_flags & TF_SIGNATURE) 3516 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3517 #endif 3518 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3519 optlen += TCPOLEN_SACKHDR; 3520 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3521 optlen = PADTCPOLEN(optlen); 3522 } 3523 } else { 3524 if (tp->t_flags & TF_REQ_TSTMP) 3525 optlen = TCPOLEN_TSTAMP_APPA; 3526 else 3527 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3528 if (tp->t_flags & TF_REQ_SCALE) 3529 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3530 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3531 if (tp->t_flags & TF_SIGNATURE) 3532 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3533 #endif 3534 if (tp->t_flags & TF_SACK_PERMIT) 3535 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3536 } 3537 #undef PAD 3538 optlen = min(optlen, TCP_MAXOLEN); 3539 return (tp->t_maxseg - optlen); 3540 } 3541 3542 3543 u_int 3544 tcp_fixed_maxseg(const struct tcpcb *tp) 3545 { 3546 int optlen; 3547 3548 if (tp->t_flags & TF_NOOPT) 3549 return (tp->t_maxseg); 3550 3551 /* 3552 * Here we have a simplified code from tcp_addoptions(), 3553 * without a proper loop, and having most of paddings hardcoded. 3554 * We only consider fixed options that we would send every 3555 * time I.e. SACK is not considered. This is important 3556 * for cc modules to figure out what the modulo of the 3557 * cwnd should be. 3558 */ 3559 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3560 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3561 if (tp->t_flags & TF_RCVD_TSTMP) 3562 optlen = TCPOLEN_TSTAMP_APPA; 3563 else 3564 optlen = 0; 3565 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3566 if (tp->t_flags & TF_SIGNATURE) 3567 optlen += PAD(TCPOLEN_SIGNATURE); 3568 #endif 3569 } else { 3570 if (tp->t_flags & TF_REQ_TSTMP) 3571 optlen = TCPOLEN_TSTAMP_APPA; 3572 else 3573 optlen = PAD(TCPOLEN_MAXSEG); 3574 if (tp->t_flags & TF_REQ_SCALE) 3575 optlen += PAD(TCPOLEN_WINDOW); 3576 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3577 if (tp->t_flags & TF_SIGNATURE) 3578 optlen += PAD(TCPOLEN_SIGNATURE); 3579 #endif 3580 if (tp->t_flags & TF_SACK_PERMIT) 3581 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3582 } 3583 #undef PAD 3584 optlen = min(optlen, TCP_MAXOLEN); 3585 return (tp->t_maxseg - optlen); 3586 } 3587 3588 3589 3590 static int 3591 sysctl_drop(SYSCTL_HANDLER_ARGS) 3592 { 3593 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3594 struct sockaddr_storage addrs[2]; 3595 struct inpcb *inp; 3596 struct tcpcb *tp; 3597 #ifdef INET 3598 struct sockaddr_in *fin = NULL, *lin = NULL; 3599 #endif 3600 struct epoch_tracker et; 3601 #ifdef INET6 3602 struct sockaddr_in6 *fin6, *lin6; 3603 #endif 3604 int error; 3605 3606 inp = NULL; 3607 #ifdef INET6 3608 fin6 = lin6 = NULL; 3609 #endif 3610 error = 0; 3611 3612 if (req->oldptr != NULL || req->oldlen != 0) 3613 return (EINVAL); 3614 if (req->newptr == NULL) 3615 return (EPERM); 3616 if (req->newlen < sizeof(addrs)) 3617 return (ENOMEM); 3618 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3619 if (error) 3620 return (error); 3621 3622 switch (addrs[0].ss_family) { 3623 #ifdef INET6 3624 case AF_INET6: 3625 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3626 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3627 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3628 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3629 return (EINVAL); 3630 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3631 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3632 return (EINVAL); 3633 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3634 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3635 #ifdef INET 3636 fin = (struct sockaddr_in *)&addrs[0]; 3637 lin = (struct sockaddr_in *)&addrs[1]; 3638 #endif 3639 break; 3640 } 3641 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3642 if (error) 3643 return (error); 3644 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3645 if (error) 3646 return (error); 3647 break; 3648 #endif 3649 #ifdef INET 3650 case AF_INET: 3651 fin = (struct sockaddr_in *)&addrs[0]; 3652 lin = (struct sockaddr_in *)&addrs[1]; 3653 if (fin->sin_len != sizeof(struct sockaddr_in) || 3654 lin->sin_len != sizeof(struct sockaddr_in)) 3655 return (EINVAL); 3656 break; 3657 #endif 3658 default: 3659 return (EINVAL); 3660 } 3661 NET_EPOCH_ENTER(et); 3662 switch (addrs[0].ss_family) { 3663 #ifdef INET6 3664 case AF_INET6: 3665 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3666 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3667 INPLOOKUP_WLOCKPCB, NULL); 3668 break; 3669 #endif 3670 #ifdef INET 3671 case AF_INET: 3672 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3673 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3674 break; 3675 #endif 3676 } 3677 if (inp != NULL) { 3678 if (!SOLISTENING(inp->inp_socket)) { 3679 tp = intotcpcb(inp); 3680 tp = tcp_drop(tp, ECONNABORTED); 3681 if (tp != NULL) 3682 INP_WUNLOCK(inp); 3683 } else 3684 INP_WUNLOCK(inp); 3685 } else 3686 error = ESRCH; 3687 NET_EPOCH_EXIT(et); 3688 return (error); 3689 } 3690 3691 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3692 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3693 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3694 "Drop TCP connection"); 3695 3696 static int 3697 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3698 { 3699 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3700 &tcp_ctloutput_set)); 3701 } 3702 3703 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3704 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3705 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3706 "Set socket option for TCP endpoint"); 3707 3708 #ifdef KERN_TLS 3709 static int 3710 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3711 { 3712 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3713 struct sockaddr_storage addrs[2]; 3714 struct inpcb *inp; 3715 #ifdef INET 3716 struct sockaddr_in *fin = NULL, *lin = NULL; 3717 #endif 3718 struct epoch_tracker et; 3719 #ifdef INET6 3720 struct sockaddr_in6 *fin6, *lin6; 3721 #endif 3722 int error; 3723 3724 inp = NULL; 3725 #ifdef INET6 3726 fin6 = lin6 = NULL; 3727 #endif 3728 error = 0; 3729 3730 if (req->oldptr != NULL || req->oldlen != 0) 3731 return (EINVAL); 3732 if (req->newptr == NULL) 3733 return (EPERM); 3734 if (req->newlen < sizeof(addrs)) 3735 return (ENOMEM); 3736 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3737 if (error) 3738 return (error); 3739 3740 switch (addrs[0].ss_family) { 3741 #ifdef INET6 3742 case AF_INET6: 3743 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3744 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3745 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3746 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3747 return (EINVAL); 3748 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3749 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3750 return (EINVAL); 3751 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3752 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3753 #ifdef INET 3754 fin = (struct sockaddr_in *)&addrs[0]; 3755 lin = (struct sockaddr_in *)&addrs[1]; 3756 #endif 3757 break; 3758 } 3759 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3760 if (error) 3761 return (error); 3762 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3763 if (error) 3764 return (error); 3765 break; 3766 #endif 3767 #ifdef INET 3768 case AF_INET: 3769 fin = (struct sockaddr_in *)&addrs[0]; 3770 lin = (struct sockaddr_in *)&addrs[1]; 3771 if (fin->sin_len != sizeof(struct sockaddr_in) || 3772 lin->sin_len != sizeof(struct sockaddr_in)) 3773 return (EINVAL); 3774 break; 3775 #endif 3776 default: 3777 return (EINVAL); 3778 } 3779 NET_EPOCH_ENTER(et); 3780 switch (addrs[0].ss_family) { 3781 #ifdef INET6 3782 case AF_INET6: 3783 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3784 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3785 INPLOOKUP_WLOCKPCB, NULL); 3786 break; 3787 #endif 3788 #ifdef INET 3789 case AF_INET: 3790 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3791 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3792 break; 3793 #endif 3794 } 3795 NET_EPOCH_EXIT(et); 3796 if (inp != NULL) { 3797 struct socket *so; 3798 3799 so = inp->inp_socket; 3800 soref(so); 3801 error = ktls_set_tx_mode(so, 3802 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3803 INP_WUNLOCK(inp); 3804 sorele(so); 3805 } else 3806 error = ESRCH; 3807 return (error); 3808 } 3809 3810 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3811 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3812 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3813 "Switch TCP connection to SW TLS"); 3814 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3815 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3816 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3817 "Switch TCP connection to ifnet TLS"); 3818 #endif 3819 3820 /* 3821 * Generate a standardized TCP log line for use throughout the 3822 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3823 * allow use in the interrupt context. 3824 * 3825 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3826 * NB: The function may return NULL if memory allocation failed. 3827 * 3828 * Due to header inclusion and ordering limitations the struct ip 3829 * and ip6_hdr pointers have to be passed as void pointers. 3830 */ 3831 char * 3832 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3833 const void *ip6hdr) 3834 { 3835 3836 /* Is logging enabled? */ 3837 if (V_tcp_log_in_vain == 0) 3838 return (NULL); 3839 3840 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3841 } 3842 3843 char * 3844 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3845 const void *ip6hdr) 3846 { 3847 3848 /* Is logging enabled? */ 3849 if (tcp_log_debug == 0) 3850 return (NULL); 3851 3852 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3853 } 3854 3855 static char * 3856 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3857 const void *ip6hdr) 3858 { 3859 char *s, *sp; 3860 size_t size; 3861 #ifdef INET 3862 const struct ip *ip = (const struct ip *)ip4hdr; 3863 #endif 3864 #ifdef INET6 3865 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3866 #endif /* INET6 */ 3867 3868 /* 3869 * The log line looks like this: 3870 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3871 */ 3872 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3873 sizeof(PRINT_TH_FLAGS) + 1 + 3874 #ifdef INET6 3875 2 * INET6_ADDRSTRLEN; 3876 #else 3877 2 * INET_ADDRSTRLEN; 3878 #endif /* INET6 */ 3879 3880 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3881 if (s == NULL) 3882 return (NULL); 3883 3884 strcat(s, "TCP: ["); 3885 sp = s + strlen(s); 3886 3887 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3888 inet_ntoa_r(inc->inc_faddr, sp); 3889 sp = s + strlen(s); 3890 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3891 sp = s + strlen(s); 3892 inet_ntoa_r(inc->inc_laddr, sp); 3893 sp = s + strlen(s); 3894 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3895 #ifdef INET6 3896 } else if (inc) { 3897 ip6_sprintf(sp, &inc->inc6_faddr); 3898 sp = s + strlen(s); 3899 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3900 sp = s + strlen(s); 3901 ip6_sprintf(sp, &inc->inc6_laddr); 3902 sp = s + strlen(s); 3903 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3904 } else if (ip6 && th) { 3905 ip6_sprintf(sp, &ip6->ip6_src); 3906 sp = s + strlen(s); 3907 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3908 sp = s + strlen(s); 3909 ip6_sprintf(sp, &ip6->ip6_dst); 3910 sp = s + strlen(s); 3911 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3912 #endif /* INET6 */ 3913 #ifdef INET 3914 } else if (ip && th) { 3915 inet_ntoa_r(ip->ip_src, sp); 3916 sp = s + strlen(s); 3917 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3918 sp = s + strlen(s); 3919 inet_ntoa_r(ip->ip_dst, sp); 3920 sp = s + strlen(s); 3921 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3922 #endif /* INET */ 3923 } else { 3924 free(s, M_TCPLOG); 3925 return (NULL); 3926 } 3927 sp = s + strlen(s); 3928 if (th) 3929 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3930 if (*(s + size - 1) != '\0') 3931 panic("%s: string too long", __func__); 3932 return (s); 3933 } 3934 3935 /* 3936 * A subroutine which makes it easy to track TCP state changes with DTrace. 3937 * This function shouldn't be called for t_state initializations that don't 3938 * correspond to actual TCP state transitions. 3939 */ 3940 void 3941 tcp_state_change(struct tcpcb *tp, int newstate) 3942 { 3943 #if defined(KDTRACE_HOOKS) 3944 int pstate = tp->t_state; 3945 #endif 3946 3947 TCPSTATES_DEC(tp->t_state); 3948 TCPSTATES_INC(newstate); 3949 tp->t_state = newstate; 3950 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3951 } 3952 3953 /* 3954 * Create an external-format (``xtcpcb'') structure using the information in 3955 * the kernel-format tcpcb structure pointed to by tp. This is done to 3956 * reduce the spew of irrelevant information over this interface, to isolate 3957 * user code from changes in the kernel structure, and potentially to provide 3958 * information-hiding if we decide that some of this information should be 3959 * hidden from users. 3960 */ 3961 void 3962 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3963 { 3964 struct tcpcb *tp = intotcpcb(inp); 3965 sbintime_t now; 3966 3967 bzero(xt, sizeof(*xt)); 3968 xt->t_state = tp->t_state; 3969 xt->t_logstate = tp->t_logstate; 3970 xt->t_flags = tp->t_flags; 3971 xt->t_sndzerowin = tp->t_sndzerowin; 3972 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3973 xt->t_rcvoopack = tp->t_rcvoopack; 3974 xt->t_rcv_wnd = tp->rcv_wnd; 3975 xt->t_snd_wnd = tp->snd_wnd; 3976 xt->t_snd_cwnd = tp->snd_cwnd; 3977 xt->t_snd_ssthresh = tp->snd_ssthresh; 3978 xt->t_dsack_bytes = tp->t_dsack_bytes; 3979 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 3980 xt->t_dsack_pack = tp->t_dsack_pack; 3981 xt->t_maxseg = tp->t_maxseg; 3982 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3983 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3984 3985 now = getsbinuptime(); 3986 #define COPYTIMER(ttt) do { \ 3987 if (callout_active(&tp->t_timers->ttt)) \ 3988 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 3989 SBT_1MS; \ 3990 else \ 3991 xt->ttt = 0; \ 3992 } while (0) 3993 COPYTIMER(tt_delack); 3994 COPYTIMER(tt_rexmt); 3995 COPYTIMER(tt_persist); 3996 COPYTIMER(tt_keep); 3997 COPYTIMER(tt_2msl); 3998 #undef COPYTIMER 3999 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4000 4001 xt->xt_encaps_port = tp->t_port; 4002 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4003 TCP_FUNCTION_NAME_LEN_MAX); 4004 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX); 4005 #ifdef TCP_BLACKBOX 4006 (void)tcp_log_get_id(tp, xt->xt_logid); 4007 #endif 4008 4009 xt->xt_len = sizeof(struct xtcpcb); 4010 in_pcbtoxinpcb(inp, &xt->xt_inp); 4011 } 4012 4013 void 4014 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4015 { 4016 uint32_t bit, i; 4017 4018 if ((tp == NULL) || 4019 (status > TCP_EI_STATUS_MAX_VALUE) || 4020 (status == 0)) { 4021 /* Invalid */ 4022 return; 4023 } 4024 if (status > (sizeof(uint32_t) * 8)) { 4025 /* Should this be a KASSERT? */ 4026 return; 4027 } 4028 bit = 1U << (status - 1); 4029 if (bit & tp->t_end_info_status) { 4030 /* already logged */ 4031 return; 4032 } 4033 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4034 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4035 tp->t_end_info_bytes[i] = status; 4036 tp->t_end_info_status |= bit; 4037 break; 4038 } 4039 } 4040 } 4041 4042 int 4043 tcp_can_enable_pacing(void) 4044 { 4045 4046 if ((tcp_pacing_limit == -1) || 4047 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4048 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4049 shadow_num_connections = number_of_tcp_connections_pacing; 4050 return (1); 4051 } else { 4052 return (0); 4053 } 4054 } 4055 4056 static uint8_t tcp_pacing_warning = 0; 4057 4058 void 4059 tcp_decrement_paced_conn(void) 4060 { 4061 uint32_t ret; 4062 4063 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4064 shadow_num_connections = number_of_tcp_connections_pacing; 4065 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4066 if (ret == 0) { 4067 if (tcp_pacing_limit != -1) { 4068 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4069 tcp_pacing_limit = 0; 4070 } else if (tcp_pacing_warning == 0) { 4071 printf("Warning pacing count is invalid, invalid decrement\n"); 4072 tcp_pacing_warning = 1; 4073 } 4074 } 4075 } 4076