Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet/tcp_subr.c
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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 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/arb.h> 45 #include <sys/callout.h> 46 #include <sys/eventhandler.h> 47 #ifdef TCP_HHOOK 48 #include <sys/hhook.h> 49 #endif 50 #include <sys/kernel.h> 51 #ifdef TCP_HHOOK 52 #include <sys/khelp.h> 53 #endif 54 #ifdef KERN_TLS 55 #include <sys/ktls.h> 56 #endif 57 #include <sys/qmath.h> 58 #include <sys/stats.h> 59 #include <sys/sysctl.h> 60 #include <sys/jail.h> 61 #include <sys/malloc.h> 62 #include <sys/refcount.h> 63 #include <sys/mbuf.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/sdt.h> 67 #include <sys/socket.h> 68 #include <sys/socketvar.h> 69 #include <sys/protosw.h> 70 #include <sys/random.h> 71 72 #include <vm/uma.h> 73 74 #include <net/route.h> 75 #include <net/route/nhop.h> 76 #include <net/if.h> 77 #include <net/if_var.h> 78 #include <net/vnet.h> 79 80 #include <netinet/in.h> 81 #include <netinet/in_fib.h> 82 #include <netinet/in_kdtrace.h> 83 #include <netinet/in_pcb.h> 84 #include <netinet/in_systm.h> 85 #include <netinet/in_var.h> 86 #include <netinet/ip.h> 87 #include <netinet/ip_icmp.h> 88 #include <netinet/ip_var.h> 89 #ifdef INET6 90 #include <netinet/icmp6.h> 91 #include <netinet/ip6.h> 92 #include <netinet6/in6_fib.h> 93 #include <netinet6/in6_pcb.h> 94 #include <netinet6/ip6_var.h> 95 #include <netinet6/scope6_var.h> 96 #include <netinet6/nd6.h> 97 #endif 98 99 #include <netinet/tcp.h> 100 #ifdef INVARIANTS 101 #define TCPSTATES 102 #endif 103 #include <netinet/tcp_fsm.h> 104 #include <netinet/tcp_seq.h> 105 #include <netinet/tcp_timer.h> 106 #include <netinet/tcp_var.h> 107 #include <netinet/tcp_ecn.h> 108 #include <netinet/tcp_log_buf.h> 109 #include <netinet/tcp_syncache.h> 110 #include <netinet/tcp_hpts.h> 111 #include <netinet/cc/cc.h> 112 #include <netinet/tcpip.h> 113 #include <netinet/tcp_fastopen.h> 114 #ifdef TCPPCAP 115 #include <netinet/tcp_pcap.h> 116 #endif 117 #ifdef TCP_OFFLOAD 118 #include <netinet/tcp_offload.h> 119 #endif 120 #include <netinet/udp.h> 121 #include <netinet/udp_var.h> 122 #ifdef INET6 123 #include <netinet6/tcp6_var.h> 124 #endif 125 126 #include <netipsec/ipsec_support.h> 127 128 #include <machine/in_cksum.h> 129 #include <crypto/siphash/siphash.h> 130 131 #include <security/mac/mac_framework.h> 132 133 #ifdef INET6 134 static ip6proto_ctlinput_t tcp6_ctlinput; 135 static udp_tun_icmp_t tcp6_ctlinput_viaudp; 136 #endif 137 138 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 139 #ifdef INET6 140 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 141 #endif 142 143 #ifdef NETFLIX_EXP_DETECTION 144 /* Sack attack detection thresholds and such */ 145 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 146 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 147 "Sack Attack detection thresholds"); 148 int32_t tcp_force_detection = 0; 149 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 150 CTLFLAG_RW, 151 &tcp_force_detection, 0, 152 "Do we force detection even if the INP has it off?"); 153 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 154 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 155 CTLFLAG_RW, 156 &tcp_sack_to_ack_thresh, 700, 157 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 158 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 159 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 160 CTLFLAG_RW, 161 &tcp_sack_to_move_thresh, 600, 162 "Percentage of sack moves we must see above (10.1 percent is 101)"); 163 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 164 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 165 CTLFLAG_RW, 166 &tcp_restoral_thresh, 550, 167 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 168 int32_t tcp_sad_decay_val = 800; 169 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 170 CTLFLAG_RW, 171 &tcp_sad_decay_val, 800, 172 "The decay percentage (10.1 percent equals 101 )"); 173 int32_t tcp_map_minimum = 500; 174 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 175 CTLFLAG_RW, 176 &tcp_map_minimum, 500, 177 "Number of Map enteries before we start detection"); 178 int32_t tcp_attack_on_turns_on_logging = 0; 179 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 180 CTLFLAG_RW, 181 &tcp_attack_on_turns_on_logging, 0, 182 "When we have a positive hit on attack, do we turn on logging?"); 183 int32_t tcp_sad_pacing_interval = 2000; 184 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 185 CTLFLAG_RW, 186 &tcp_sad_pacing_interval, 2000, 187 "What is the minimum pacing interval for a classified attacker?"); 188 189 int32_t tcp_sad_low_pps = 100; 190 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 191 CTLFLAG_RW, 192 &tcp_sad_low_pps, 100, 193 "What is the input pps that below which we do not decay?"); 194 #endif 195 uint32_t tcp_ack_war_time_window = 1000; 196 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 197 CTLFLAG_RW, 198 &tcp_ack_war_time_window, 1000, 199 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 200 uint32_t tcp_ack_war_cnt = 5; 201 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 202 CTLFLAG_RW, 203 &tcp_ack_war_cnt, 5, 204 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 205 206 struct rwlock tcp_function_lock; 207 208 static int 209 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 210 { 211 int error, new; 212 213 new = V_tcp_mssdflt; 214 error = sysctl_handle_int(oidp, &new, 0, req); 215 if (error == 0 && req->newptr) { 216 if (new < TCP_MINMSS) 217 error = EINVAL; 218 else 219 V_tcp_mssdflt = new; 220 } 221 return (error); 222 } 223 224 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 225 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 226 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 227 "Default TCP Maximum Segment Size"); 228 229 #ifdef INET6 230 static int 231 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 232 { 233 int error, new; 234 235 new = V_tcp_v6mssdflt; 236 error = sysctl_handle_int(oidp, &new, 0, req); 237 if (error == 0 && req->newptr) { 238 if (new < TCP_MINMSS) 239 error = EINVAL; 240 else 241 V_tcp_v6mssdflt = new; 242 } 243 return (error); 244 } 245 246 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 247 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 248 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 249 "Default TCP Maximum Segment Size for IPv6"); 250 #endif /* INET6 */ 251 252 /* 253 * Minimum MSS we accept and use. This prevents DoS attacks where 254 * we are forced to a ridiculous low MSS like 20 and send hundreds 255 * of packets instead of one. The effect scales with the available 256 * bandwidth and quickly saturates the CPU and network interface 257 * with packet generation and sending. Set to zero to disable MINMSS 258 * checking. This setting prevents us from sending too small packets. 259 */ 260 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 261 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 262 &VNET_NAME(tcp_minmss), 0, 263 "Minimum TCP Maximum Segment Size"); 264 265 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 266 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 267 &VNET_NAME(tcp_do_rfc1323), 0, 268 "Enable rfc1323 (high performance TCP) extensions"); 269 270 /* 271 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 272 * Some stacks negotiate TS, but never send them after connection setup. Some 273 * stacks negotiate TS, but don't send them when sending keep-alive segments. 274 * These include modern widely deployed TCP stacks. 275 * Therefore tolerating violations for now... 276 */ 277 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 278 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 279 &VNET_NAME(tcp_tolerate_missing_ts), 0, 280 "Tolerate missing TCP timestamps"); 281 282 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 283 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 284 &VNET_NAME(tcp_ts_offset_per_conn), 0, 285 "Initialize TCP timestamps per connection instead of per host pair"); 286 287 /* How many connections are pacing */ 288 static volatile uint32_t number_of_tcp_connections_pacing = 0; 289 static uint32_t shadow_num_connections = 0; 290 291 static int tcp_pacing_limit = 10000; 292 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 293 &tcp_pacing_limit, 1000, 294 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 295 296 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 297 &shadow_num_connections, 0, "Number of TCP connections being paced"); 298 299 static int tcp_log_debug = 0; 300 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 301 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 302 303 static int tcp_tcbhashsize; 304 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 305 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 306 307 static int do_tcpdrain = 1; 308 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 309 "Enable tcp_drain routine for extra help when low on mbufs"); 310 311 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 312 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 313 314 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 315 #define V_icmp_may_rst VNET(icmp_may_rst) 316 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 317 &VNET_NAME(icmp_may_rst), 0, 318 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 319 320 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 321 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 322 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 323 &VNET_NAME(tcp_isn_reseed_interval), 0, 324 "Seconds between reseeding of ISN secret"); 325 326 static int tcp_soreceive_stream; 327 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 328 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 329 330 VNET_DEFINE(uma_zone_t, sack_hole_zone); 331 #define V_sack_hole_zone VNET(sack_hole_zone) 332 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 333 static int 334 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 335 { 336 int error; 337 uint32_t new; 338 339 new = V_tcp_map_entries_limit; 340 error = sysctl_handle_int(oidp, &new, 0, req); 341 if (error == 0 && req->newptr) { 342 /* only allow "" and value > minimum */ 343 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 344 error = EINVAL; 345 else 346 V_tcp_map_entries_limit = new; 347 } 348 return (error); 349 } 350 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 351 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 352 &VNET_NAME(tcp_map_entries_limit), 0, 353 &sysctl_net_inet_tcp_map_limit_check, "IU", 354 "Total sendmap entries limit"); 355 356 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 357 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 358 &VNET_NAME(tcp_map_split_limit), 0, 359 "Total sendmap split entries limit"); 360 361 #ifdef TCP_HHOOK 362 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 363 #endif 364 365 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 366 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 367 #define V_ts_offset_secret VNET(ts_offset_secret) 368 369 static int tcp_default_fb_init(struct tcpcb *tp); 370 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 371 static int tcp_default_handoff_ok(struct tcpcb *tp); 372 static struct inpcb *tcp_notify(struct inpcb *, int); 373 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 374 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 375 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int); 376 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 377 const void *ip4hdr, const void *ip6hdr); 378 static ipproto_ctlinput_t tcp_ctlinput; 379 static udp_tun_icmp_t tcp_ctlinput_viaudp; 380 381 static struct tcp_function_block tcp_def_funcblk = { 382 .tfb_tcp_block_name = "freebsd", 383 .tfb_tcp_output = tcp_default_output, 384 .tfb_tcp_do_segment = tcp_do_segment, 385 .tfb_tcp_ctloutput = tcp_default_ctloutput, 386 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 387 .tfb_tcp_fb_init = tcp_default_fb_init, 388 .tfb_tcp_fb_fini = tcp_default_fb_fini, 389 }; 390 391 static int tcp_fb_cnt = 0; 392 struct tcp_funchead t_functions; 393 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 394 395 void 396 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 397 { 398 TCPSTAT_INC(tcps_dsack_count); 399 tp->t_dsack_pack++; 400 if (tlp == 0) { 401 if (SEQ_GT(end, start)) { 402 tp->t_dsack_bytes += (end - start); 403 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 404 } else { 405 tp->t_dsack_tlp_bytes += (start - end); 406 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 407 } 408 } else { 409 if (SEQ_GT(end, start)) { 410 tp->t_dsack_bytes += (end - start); 411 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 412 } else { 413 tp->t_dsack_tlp_bytes += (start - end); 414 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 415 } 416 } 417 } 418 419 static struct tcp_function_block * 420 find_tcp_functions_locked(struct tcp_function_set *fs) 421 { 422 struct tcp_function *f; 423 struct tcp_function_block *blk=NULL; 424 425 TAILQ_FOREACH(f, &t_functions, tf_next) { 426 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 427 blk = f->tf_fb; 428 break; 429 } 430 } 431 return(blk); 432 } 433 434 static struct tcp_function_block * 435 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 436 { 437 struct tcp_function_block *rblk=NULL; 438 struct tcp_function *f; 439 440 TAILQ_FOREACH(f, &t_functions, tf_next) { 441 if (f->tf_fb == blk) { 442 rblk = blk; 443 if (s) { 444 *s = f; 445 } 446 break; 447 } 448 } 449 return (rblk); 450 } 451 452 struct tcp_function_block * 453 find_and_ref_tcp_functions(struct tcp_function_set *fs) 454 { 455 struct tcp_function_block *blk; 456 457 rw_rlock(&tcp_function_lock); 458 blk = find_tcp_functions_locked(fs); 459 if (blk) 460 refcount_acquire(&blk->tfb_refcnt); 461 rw_runlock(&tcp_function_lock); 462 return(blk); 463 } 464 465 struct tcp_function_block * 466 find_and_ref_tcp_fb(struct tcp_function_block *blk) 467 { 468 struct tcp_function_block *rblk; 469 470 rw_rlock(&tcp_function_lock); 471 rblk = find_tcp_fb_locked(blk, NULL); 472 if (rblk) 473 refcount_acquire(&rblk->tfb_refcnt); 474 rw_runlock(&tcp_function_lock); 475 return(rblk); 476 } 477 478 /* Find a matching alias for the given tcp_function_block. */ 479 int 480 find_tcp_function_alias(struct tcp_function_block *blk, 481 struct tcp_function_set *fs) 482 { 483 struct tcp_function *f; 484 int found; 485 486 found = 0; 487 rw_rlock(&tcp_function_lock); 488 TAILQ_FOREACH(f, &t_functions, tf_next) { 489 if ((f->tf_fb == blk) && 490 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 491 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 492 /* Matching function block with different name. */ 493 strncpy(fs->function_set_name, f->tf_name, 494 TCP_FUNCTION_NAME_LEN_MAX); 495 found = 1; 496 break; 497 } 498 } 499 /* Null terminate the string appropriately. */ 500 if (found) { 501 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 502 } else { 503 fs->function_set_name[0] = '\0'; 504 } 505 rw_runlock(&tcp_function_lock); 506 return (found); 507 } 508 509 static struct tcp_function_block * 510 find_and_ref_tcp_default_fb(void) 511 { 512 struct tcp_function_block *rblk; 513 514 rw_rlock(&tcp_function_lock); 515 rblk = tcp_func_set_ptr; 516 refcount_acquire(&rblk->tfb_refcnt); 517 rw_runlock(&tcp_function_lock); 518 return (rblk); 519 } 520 521 void 522 tcp_switch_back_to_default(struct tcpcb *tp) 523 { 524 struct tcp_function_block *tfb; 525 526 KASSERT(tp->t_fb != &tcp_def_funcblk, 527 ("%s: called by the built-in default stack", __func__)); 528 529 /* 530 * Release the old stack. This function will either find a new one 531 * or panic. 532 */ 533 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 534 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 535 refcount_release(&tp->t_fb->tfb_refcnt); 536 537 /* 538 * Now, we'll find a new function block to use. 539 * Start by trying the current user-selected 540 * default, unless this stack is the user-selected 541 * default. 542 */ 543 tfb = find_and_ref_tcp_default_fb(); 544 if (tfb == tp->t_fb) { 545 refcount_release(&tfb->tfb_refcnt); 546 tfb = NULL; 547 } 548 /* Does the stack accept this connection? */ 549 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 550 (*tfb->tfb_tcp_handoff_ok)(tp)) { 551 refcount_release(&tfb->tfb_refcnt); 552 tfb = NULL; 553 } 554 /* Try to use that stack. */ 555 if (tfb != NULL) { 556 /* Initialize the new stack. If it succeeds, we are done. */ 557 tp->t_fb = tfb; 558 if (tp->t_fb->tfb_tcp_fb_init == NULL || 559 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 560 return; 561 562 /* 563 * Initialization failed. Release the reference count on 564 * the stack. 565 */ 566 refcount_release(&tfb->tfb_refcnt); 567 } 568 569 /* 570 * If that wasn't feasible, use the built-in default 571 * stack which is not allowed to reject anyone. 572 */ 573 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 574 if (tfb == NULL) { 575 /* there always should be a default */ 576 panic("Can't refer to tcp_def_funcblk"); 577 } 578 if (tfb->tfb_tcp_handoff_ok != NULL) { 579 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 580 /* The default stack cannot say no */ 581 panic("Default stack rejects a new session?"); 582 } 583 } 584 tp->t_fb = tfb; 585 if (tp->t_fb->tfb_tcp_fb_init != NULL && 586 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 587 /* The default stack cannot fail */ 588 panic("Default stack initialization failed"); 589 } 590 } 591 592 static bool 593 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 594 const struct sockaddr *sa, void *ctx) 595 { 596 struct ip *iph; 597 #ifdef INET6 598 struct ip6_hdr *ip6; 599 #endif 600 struct udphdr *uh; 601 struct tcphdr *th; 602 int thlen; 603 uint16_t port; 604 605 TCPSTAT_INC(tcps_tunneled_pkts); 606 if ((m->m_flags & M_PKTHDR) == 0) { 607 /* Can't handle one that is not a pkt hdr */ 608 TCPSTAT_INC(tcps_tunneled_errs); 609 goto out; 610 } 611 thlen = sizeof(struct tcphdr); 612 if (m->m_len < off + sizeof(struct udphdr) + thlen && 613 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 614 TCPSTAT_INC(tcps_tunneled_errs); 615 goto out; 616 } 617 iph = mtod(m, struct ip *); 618 uh = (struct udphdr *)((caddr_t)iph + off); 619 th = (struct tcphdr *)(uh + 1); 620 thlen = th->th_off << 2; 621 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 622 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 623 if (m == NULL) { 624 TCPSTAT_INC(tcps_tunneled_errs); 625 goto out; 626 } else { 627 iph = mtod(m, struct ip *); 628 uh = (struct udphdr *)((caddr_t)iph + off); 629 th = (struct tcphdr *)(uh + 1); 630 } 631 } 632 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 633 bcopy(th, uh, m->m_len - off); 634 m->m_len -= sizeof(struct udphdr); 635 m->m_pkthdr.len -= sizeof(struct udphdr); 636 /* 637 * We use the same algorithm for 638 * both UDP and TCP for c-sum. So 639 * the code in tcp_input will skip 640 * the checksum. So we do nothing 641 * with the flag (m->m_pkthdr.csum_flags). 642 */ 643 switch (iph->ip_v) { 644 #ifdef INET 645 case IPVERSION: 646 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 647 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 648 break; 649 #endif 650 #ifdef INET6 651 case IPV6_VERSION >> 4: 652 ip6 = mtod(m, struct ip6_hdr *); 653 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 654 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 655 break; 656 #endif 657 default: 658 goto out; 659 break; 660 } 661 return (true); 662 out: 663 m_freem(m); 664 665 return (true); 666 } 667 668 static int 669 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 670 { 671 int error=ENOENT; 672 struct tcp_function_set fs; 673 struct tcp_function_block *blk; 674 675 memset(&fs, 0, sizeof(fs)); 676 rw_rlock(&tcp_function_lock); 677 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 678 if (blk) { 679 /* Found him */ 680 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 681 fs.pcbcnt = blk->tfb_refcnt; 682 } 683 rw_runlock(&tcp_function_lock); 684 error = sysctl_handle_string(oidp, fs.function_set_name, 685 sizeof(fs.function_set_name), req); 686 687 /* Check for error or no change */ 688 if (error != 0 || req->newptr == NULL) 689 return(error); 690 691 rw_wlock(&tcp_function_lock); 692 blk = find_tcp_functions_locked(&fs); 693 if ((blk == NULL) || 694 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 695 error = ENOENT; 696 goto done; 697 } 698 tcp_func_set_ptr = blk; 699 done: 700 rw_wunlock(&tcp_function_lock); 701 return (error); 702 } 703 704 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 705 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 706 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 707 "Set/get the default TCP functions"); 708 709 static int 710 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 711 { 712 int error, cnt, linesz; 713 struct tcp_function *f; 714 char *buffer, *cp; 715 size_t bufsz, outsz; 716 bool alias; 717 718 cnt = 0; 719 rw_rlock(&tcp_function_lock); 720 TAILQ_FOREACH(f, &t_functions, tf_next) { 721 cnt++; 722 } 723 rw_runlock(&tcp_function_lock); 724 725 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 726 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 727 728 error = 0; 729 cp = buffer; 730 731 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 732 "Alias", "PCB count"); 733 cp += linesz; 734 bufsz -= linesz; 735 outsz = linesz; 736 737 rw_rlock(&tcp_function_lock); 738 TAILQ_FOREACH(f, &t_functions, tf_next) { 739 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 740 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 741 f->tf_fb->tfb_tcp_block_name, 742 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 743 alias ? f->tf_name : "-", 744 f->tf_fb->tfb_refcnt); 745 if (linesz >= bufsz) { 746 error = EOVERFLOW; 747 break; 748 } 749 cp += linesz; 750 bufsz -= linesz; 751 outsz += linesz; 752 } 753 rw_runlock(&tcp_function_lock); 754 if (error == 0) 755 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 756 free(buffer, M_TEMP); 757 return (error); 758 } 759 760 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 761 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 762 NULL, 0, sysctl_net_inet_list_available, "A", 763 "list available TCP Function sets"); 764 765 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 766 767 #ifdef INET 768 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 769 #define V_udp4_tun_socket VNET(udp4_tun_socket) 770 #endif 771 #ifdef INET6 772 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 773 #define V_udp6_tun_socket VNET(udp6_tun_socket) 774 #endif 775 776 static struct sx tcpoudp_lock; 777 778 static void 779 tcp_over_udp_stop(void) 780 { 781 782 sx_assert(&tcpoudp_lock, SA_XLOCKED); 783 784 #ifdef INET 785 if (V_udp4_tun_socket != NULL) { 786 soclose(V_udp4_tun_socket); 787 V_udp4_tun_socket = NULL; 788 } 789 #endif 790 #ifdef INET6 791 if (V_udp6_tun_socket != NULL) { 792 soclose(V_udp6_tun_socket); 793 V_udp6_tun_socket = NULL; 794 } 795 #endif 796 } 797 798 static int 799 tcp_over_udp_start(void) 800 { 801 uint16_t port; 802 int ret; 803 #ifdef INET 804 struct sockaddr_in sin; 805 #endif 806 #ifdef INET6 807 struct sockaddr_in6 sin6; 808 #endif 809 810 sx_assert(&tcpoudp_lock, SA_XLOCKED); 811 812 port = V_tcp_udp_tunneling_port; 813 if (ntohs(port) == 0) { 814 /* Must have a port set */ 815 return (EINVAL); 816 } 817 #ifdef INET 818 if (V_udp4_tun_socket != NULL) { 819 /* Already running -- must stop first */ 820 return (EALREADY); 821 } 822 #endif 823 #ifdef INET6 824 if (V_udp6_tun_socket != NULL) { 825 /* Already running -- must stop first */ 826 return (EALREADY); 827 } 828 #endif 829 #ifdef INET 830 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 831 SOCK_DGRAM, IPPROTO_UDP, 832 curthread->td_ucred, curthread))) { 833 tcp_over_udp_stop(); 834 return (ret); 835 } 836 /* Call the special UDP hook. */ 837 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 838 tcp_recv_udp_tunneled_packet, 839 tcp_ctlinput_viaudp, 840 NULL))) { 841 tcp_over_udp_stop(); 842 return (ret); 843 } 844 /* Ok, we have a socket, bind it to the port. */ 845 memset(&sin, 0, sizeof(struct sockaddr_in)); 846 sin.sin_len = sizeof(struct sockaddr_in); 847 sin.sin_family = AF_INET; 848 sin.sin_port = htons(port); 849 if ((ret = sobind(V_udp4_tun_socket, 850 (struct sockaddr *)&sin, curthread))) { 851 tcp_over_udp_stop(); 852 return (ret); 853 } 854 #endif 855 #ifdef INET6 856 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 857 SOCK_DGRAM, IPPROTO_UDP, 858 curthread->td_ucred, curthread))) { 859 tcp_over_udp_stop(); 860 return (ret); 861 } 862 /* Call the special UDP hook. */ 863 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 864 tcp_recv_udp_tunneled_packet, 865 tcp6_ctlinput_viaudp, 866 NULL))) { 867 tcp_over_udp_stop(); 868 return (ret); 869 } 870 /* Ok, we have a socket, bind it to the port. */ 871 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 872 sin6.sin6_len = sizeof(struct sockaddr_in6); 873 sin6.sin6_family = AF_INET6; 874 sin6.sin6_port = htons(port); 875 if ((ret = sobind(V_udp6_tun_socket, 876 (struct sockaddr *)&sin6, curthread))) { 877 tcp_over_udp_stop(); 878 return (ret); 879 } 880 #endif 881 return (0); 882 } 883 884 static int 885 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 886 { 887 int error; 888 uint32_t old, new; 889 890 old = V_tcp_udp_tunneling_port; 891 new = old; 892 error = sysctl_handle_int(oidp, &new, 0, req); 893 if ((error == 0) && 894 (req->newptr != NULL)) { 895 if ((new < TCP_TUNNELING_PORT_MIN) || 896 (new > TCP_TUNNELING_PORT_MAX)) { 897 error = EINVAL; 898 } else { 899 sx_xlock(&tcpoudp_lock); 900 V_tcp_udp_tunneling_port = new; 901 if (old != 0) { 902 tcp_over_udp_stop(); 903 } 904 if (new != 0) { 905 error = tcp_over_udp_start(); 906 if (error != 0) { 907 V_tcp_udp_tunneling_port = 0; 908 } 909 } 910 sx_xunlock(&tcpoudp_lock); 911 } 912 } 913 return (error); 914 } 915 916 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 917 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 918 &VNET_NAME(tcp_udp_tunneling_port), 919 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 920 "Tunneling port for tcp over udp"); 921 922 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 923 924 static int 925 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 926 { 927 int error, new; 928 929 new = V_tcp_udp_tunneling_overhead; 930 error = sysctl_handle_int(oidp, &new, 0, req); 931 if (error == 0 && req->newptr) { 932 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 933 (new > TCP_TUNNELING_OVERHEAD_MAX)) 934 error = EINVAL; 935 else 936 V_tcp_udp_tunneling_overhead = new; 937 } 938 return (error); 939 } 940 941 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 942 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 943 &VNET_NAME(tcp_udp_tunneling_overhead), 944 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 945 "MSS reduction when using tcp over udp"); 946 947 /* 948 * Exports one (struct tcp_function_info) for each alias/name. 949 */ 950 static int 951 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 952 { 953 int cnt, error; 954 struct tcp_function *f; 955 struct tcp_function_info tfi; 956 957 /* 958 * We don't allow writes. 959 */ 960 if (req->newptr != NULL) 961 return (EINVAL); 962 963 /* 964 * Wire the old buffer so we can directly copy the functions to 965 * user space without dropping the lock. 966 */ 967 if (req->oldptr != NULL) { 968 error = sysctl_wire_old_buffer(req, 0); 969 if (error) 970 return (error); 971 } 972 973 /* 974 * Walk the list and copy out matching entries. If INVARIANTS 975 * is compiled in, also walk the list to verify the length of 976 * the list matches what we have recorded. 977 */ 978 rw_rlock(&tcp_function_lock); 979 980 cnt = 0; 981 #ifndef INVARIANTS 982 if (req->oldptr == NULL) { 983 cnt = tcp_fb_cnt; 984 goto skip_loop; 985 } 986 #endif 987 TAILQ_FOREACH(f, &t_functions, tf_next) { 988 #ifdef INVARIANTS 989 cnt++; 990 #endif 991 if (req->oldptr != NULL) { 992 bzero(&tfi, sizeof(tfi)); 993 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 994 tfi.tfi_id = f->tf_fb->tfb_id; 995 (void)strlcpy(tfi.tfi_alias, f->tf_name, 996 sizeof(tfi.tfi_alias)); 997 (void)strlcpy(tfi.tfi_name, 998 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 999 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 1000 /* 1001 * Don't stop on error, as that is the 1002 * mechanism we use to accumulate length 1003 * information if the buffer was too short. 1004 */ 1005 } 1006 } 1007 KASSERT(cnt == tcp_fb_cnt, 1008 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1009 #ifndef INVARIANTS 1010 skip_loop: 1011 #endif 1012 rw_runlock(&tcp_function_lock); 1013 if (req->oldptr == NULL) 1014 error = SYSCTL_OUT(req, NULL, 1015 (cnt + 1) * sizeof(struct tcp_function_info)); 1016 1017 return (error); 1018 } 1019 1020 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1021 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1022 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1023 "List TCP function block name-to-ID mappings"); 1024 1025 /* 1026 * tfb_tcp_handoff_ok() function for the default stack. 1027 * Note that we'll basically try to take all comers. 1028 */ 1029 static int 1030 tcp_default_handoff_ok(struct tcpcb *tp) 1031 { 1032 1033 return (0); 1034 } 1035 1036 /* 1037 * tfb_tcp_fb_init() function for the default stack. 1038 * 1039 * This handles making sure we have appropriate timers set if you are 1040 * transitioning a socket that has some amount of setup done. 1041 * 1042 * The init() fuction from the default can *never* return non-zero i.e. 1043 * it is required to always succeed since it is the stack of last resort! 1044 */ 1045 static int 1046 tcp_default_fb_init(struct tcpcb *tp) 1047 { 1048 struct socket *so = tptosocket(tp); 1049 1050 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1051 1052 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1053 ("%s: connection %p in unexpected state %d", __func__, tp, 1054 tp->t_state)); 1055 1056 /* 1057 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1058 * know what to do for unexpected states (which includes TIME_WAIT). 1059 */ 1060 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1061 return (0); 1062 1063 /* 1064 * Make sure some kind of transmission timer is set if there is 1065 * outstanding data. 1066 */ 1067 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1068 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1069 tcp_timer_active(tp, TT_PERSIST))) { 1070 /* 1071 * If the session has established and it looks like it should 1072 * be in the persist state, set the persist timer. Otherwise, 1073 * set the retransmit timer. 1074 */ 1075 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1076 (int32_t)(tp->snd_nxt - tp->snd_una) < 1077 (int32_t)sbavail(&so->so_snd)) 1078 tcp_setpersist(tp); 1079 else 1080 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1081 } 1082 1083 /* All non-embryonic sessions get a keepalive timer. */ 1084 if (!tcp_timer_active(tp, TT_KEEP)) 1085 tcp_timer_activate(tp, TT_KEEP, 1086 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1087 TP_KEEPINIT(tp)); 1088 1089 /* 1090 * Make sure critical variables are initialized 1091 * if transitioning while in Recovery. 1092 */ 1093 if IN_FASTRECOVERY(tp->t_flags) { 1094 if (tp->sackhint.recover_fs == 0) 1095 tp->sackhint.recover_fs = max(1, 1096 tp->snd_nxt - tp->snd_una); 1097 } 1098 1099 return (0); 1100 } 1101 1102 /* 1103 * tfb_tcp_fb_fini() function for the default stack. 1104 * 1105 * This changes state as necessary (or prudent) to prepare for another stack 1106 * to assume responsibility for the connection. 1107 */ 1108 static void 1109 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1110 { 1111 1112 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1113 } 1114 1115 /* 1116 * Target size of TCP PCB hash tables. Must be a power of two. 1117 * 1118 * Note that this can be overridden by the kernel environment 1119 * variable net.inet.tcp.tcbhashsize 1120 */ 1121 #ifndef TCBHASHSIZE 1122 #define TCBHASHSIZE 0 1123 #endif 1124 1125 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1126 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1127 1128 static struct mtx isn_mtx; 1129 1130 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1131 #define ISN_LOCK() mtx_lock(&isn_mtx) 1132 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1133 1134 INPCBSTORAGE_DEFINE(tcpcbstor, tcpcb, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1135 1136 /* 1137 * Take a value and get the next power of 2 that doesn't overflow. 1138 * Used to size the tcp_inpcb hash buckets. 1139 */ 1140 static int 1141 maketcp_hashsize(int size) 1142 { 1143 int hashsize; 1144 1145 /* 1146 * auto tune. 1147 * get the next power of 2 higher than maxsockets. 1148 */ 1149 hashsize = 1 << fls(size); 1150 /* catch overflow, and just go one power of 2 smaller */ 1151 if (hashsize < size) { 1152 hashsize = 1 << (fls(size) - 1); 1153 } 1154 return (hashsize); 1155 } 1156 1157 static volatile int next_tcp_stack_id = 1; 1158 1159 /* 1160 * Register a TCP function block with the name provided in the names 1161 * array. (Note that this function does NOT automatically register 1162 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1163 * explicitly include blk->tfb_tcp_block_name in the list of names if 1164 * you wish to register the stack with that name.) 1165 * 1166 * Either all name registrations will succeed or all will fail. If 1167 * a name registration fails, the function will update the num_names 1168 * argument to point to the array index of the name that encountered 1169 * the failure. 1170 * 1171 * Returns 0 on success, or an error code on failure. 1172 */ 1173 int 1174 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1175 const char *names[], int *num_names) 1176 { 1177 struct tcp_function *n; 1178 struct tcp_function_set fs; 1179 int error, i; 1180 1181 KASSERT(names != NULL && *num_names > 0, 1182 ("%s: Called with 0-length name list", __func__)); 1183 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1184 KASSERT(rw_initialized(&tcp_function_lock), 1185 ("%s: called too early", __func__)); 1186 1187 if ((blk->tfb_tcp_output == NULL) || 1188 (blk->tfb_tcp_do_segment == NULL) || 1189 (blk->tfb_tcp_ctloutput == NULL) || 1190 (strlen(blk->tfb_tcp_block_name) == 0)) { 1191 /* 1192 * These functions are required and you 1193 * need a name. 1194 */ 1195 *num_names = 0; 1196 return (EINVAL); 1197 } 1198 1199 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1200 *num_names = 0; 1201 return (EINVAL); 1202 } 1203 1204 refcount_init(&blk->tfb_refcnt, 0); 1205 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1206 for (i = 0; i < *num_names; i++) { 1207 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1208 if (n == NULL) { 1209 error = ENOMEM; 1210 goto cleanup; 1211 } 1212 n->tf_fb = blk; 1213 1214 (void)strlcpy(fs.function_set_name, names[i], 1215 sizeof(fs.function_set_name)); 1216 rw_wlock(&tcp_function_lock); 1217 if (find_tcp_functions_locked(&fs) != NULL) { 1218 /* Duplicate name space not allowed */ 1219 rw_wunlock(&tcp_function_lock); 1220 free(n, M_TCPFUNCTIONS); 1221 error = EALREADY; 1222 goto cleanup; 1223 } 1224 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1225 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1226 tcp_fb_cnt++; 1227 rw_wunlock(&tcp_function_lock); 1228 } 1229 return(0); 1230 1231 cleanup: 1232 /* 1233 * Deregister the names we just added. Because registration failed 1234 * for names[i], we don't need to deregister that name. 1235 */ 1236 *num_names = i; 1237 rw_wlock(&tcp_function_lock); 1238 while (--i >= 0) { 1239 TAILQ_FOREACH(n, &t_functions, tf_next) { 1240 if (!strncmp(n->tf_name, names[i], 1241 TCP_FUNCTION_NAME_LEN_MAX)) { 1242 TAILQ_REMOVE(&t_functions, n, tf_next); 1243 tcp_fb_cnt--; 1244 n->tf_fb = NULL; 1245 free(n, M_TCPFUNCTIONS); 1246 break; 1247 } 1248 } 1249 } 1250 rw_wunlock(&tcp_function_lock); 1251 return (error); 1252 } 1253 1254 /* 1255 * Register a TCP function block using the name provided in the name 1256 * argument. 1257 * 1258 * Returns 0 on success, or an error code on failure. 1259 */ 1260 int 1261 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1262 int wait) 1263 { 1264 const char *name_list[1]; 1265 int num_names, rv; 1266 1267 num_names = 1; 1268 if (name != NULL) 1269 name_list[0] = name; 1270 else 1271 name_list[0] = blk->tfb_tcp_block_name; 1272 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1273 return (rv); 1274 } 1275 1276 /* 1277 * Register a TCP function block using the name defined in 1278 * blk->tfb_tcp_block_name. 1279 * 1280 * Returns 0 on success, or an error code on failure. 1281 */ 1282 int 1283 register_tcp_functions(struct tcp_function_block *blk, int wait) 1284 { 1285 1286 return (register_tcp_functions_as_name(blk, NULL, wait)); 1287 } 1288 1289 /* 1290 * Deregister all names associated with a function block. This 1291 * functionally removes the function block from use within the system. 1292 * 1293 * When called with a true quiesce argument, mark the function block 1294 * as being removed so no more stacks will use it and determine 1295 * whether the removal would succeed. 1296 * 1297 * When called with a false quiesce argument, actually attempt the 1298 * removal. 1299 * 1300 * When called with a force argument, attempt to switch all TCBs to 1301 * use the default stack instead of returning EBUSY. 1302 * 1303 * Returns 0 on success (or if the removal would succeed, or an error 1304 * code on failure. 1305 */ 1306 int 1307 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1308 bool force) 1309 { 1310 struct tcp_function *f; 1311 1312 if (blk == &tcp_def_funcblk) { 1313 /* You can't un-register the default */ 1314 return (EPERM); 1315 } 1316 rw_wlock(&tcp_function_lock); 1317 if (blk == tcp_func_set_ptr) { 1318 /* You can't free the current default */ 1319 rw_wunlock(&tcp_function_lock); 1320 return (EBUSY); 1321 } 1322 /* Mark the block so no more stacks can use it. */ 1323 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1324 /* 1325 * If TCBs are still attached to the stack, attempt to switch them 1326 * to the default stack. 1327 */ 1328 if (force && blk->tfb_refcnt) { 1329 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1330 INPLOOKUP_WLOCKPCB); 1331 struct inpcb *inp; 1332 struct tcpcb *tp; 1333 VNET_ITERATOR_DECL(vnet_iter); 1334 1335 rw_wunlock(&tcp_function_lock); 1336 1337 VNET_LIST_RLOCK(); 1338 VNET_FOREACH(vnet_iter) { 1339 CURVNET_SET(vnet_iter); 1340 while ((inp = inp_next(&inpi)) != NULL) { 1341 tp = intotcpcb(inp); 1342 if (tp == NULL || tp->t_fb != blk) 1343 continue; 1344 tcp_switch_back_to_default(tp); 1345 } 1346 CURVNET_RESTORE(); 1347 } 1348 VNET_LIST_RUNLOCK(); 1349 1350 rw_wlock(&tcp_function_lock); 1351 } 1352 if (blk->tfb_refcnt) { 1353 /* TCBs still attached. */ 1354 rw_wunlock(&tcp_function_lock); 1355 return (EBUSY); 1356 } 1357 if (quiesce) { 1358 /* Skip removal. */ 1359 rw_wunlock(&tcp_function_lock); 1360 return (0); 1361 } 1362 /* Remove any function names that map to this function block. */ 1363 while (find_tcp_fb_locked(blk, &f) != NULL) { 1364 TAILQ_REMOVE(&t_functions, f, tf_next); 1365 tcp_fb_cnt--; 1366 f->tf_fb = NULL; 1367 free(f, M_TCPFUNCTIONS); 1368 } 1369 rw_wunlock(&tcp_function_lock); 1370 return (0); 1371 } 1372 1373 static void 1374 tcp_drain(void) 1375 { 1376 struct epoch_tracker et; 1377 VNET_ITERATOR_DECL(vnet_iter); 1378 1379 if (!do_tcpdrain) 1380 return; 1381 1382 NET_EPOCH_ENTER(et); 1383 VNET_LIST_RLOCK_NOSLEEP(); 1384 VNET_FOREACH(vnet_iter) { 1385 CURVNET_SET(vnet_iter); 1386 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1387 INPLOOKUP_WLOCKPCB); 1388 struct inpcb *inpb; 1389 struct tcpcb *tcpb; 1390 1391 /* 1392 * Walk the tcpbs, if existing, and flush the reassembly queue, 1393 * if there is one... 1394 * XXX: The "Net/3" implementation doesn't imply that the TCP 1395 * reassembly queue should be flushed, but in a situation 1396 * where we're really low on mbufs, this is potentially 1397 * useful. 1398 */ 1399 while ((inpb = inp_next(&inpi)) != NULL) { 1400 if ((tcpb = intotcpcb(inpb)) != NULL) { 1401 tcp_reass_flush(tcpb); 1402 tcp_clean_sackreport(tcpb); 1403 #ifdef TCP_BLACKBOX 1404 tcp_log_drain(tcpb); 1405 #endif 1406 #ifdef TCPPCAP 1407 if (tcp_pcap_aggressive_free) { 1408 /* Free the TCP PCAP queues. */ 1409 tcp_pcap_drain(&(tcpb->t_inpkts)); 1410 tcp_pcap_drain(&(tcpb->t_outpkts)); 1411 } 1412 #endif 1413 } 1414 } 1415 CURVNET_RESTORE(); 1416 } 1417 VNET_LIST_RUNLOCK_NOSLEEP(); 1418 NET_EPOCH_EXIT(et); 1419 } 1420 1421 static void 1422 tcp_vnet_init(void *arg __unused) 1423 { 1424 1425 #ifdef TCP_HHOOK 1426 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1427 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1428 printf("%s: WARNING: unable to register helper hook\n", __func__); 1429 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1430 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1431 printf("%s: WARNING: unable to register helper hook\n", __func__); 1432 #endif 1433 #ifdef STATS 1434 if (tcp_stats_init()) 1435 printf("%s: WARNING: unable to initialise TCP stats\n", 1436 __func__); 1437 #endif 1438 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1439 tcp_tcbhashsize); 1440 1441 syncache_init(); 1442 tcp_hc_init(); 1443 1444 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1445 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1446 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1447 1448 tcp_fastopen_init(); 1449 1450 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1451 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1452 1453 V_tcp_msl = TCPTV_MSL; 1454 } 1455 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1456 tcp_vnet_init, NULL); 1457 1458 static void 1459 tcp_init(void *arg __unused) 1460 { 1461 const char *tcbhash_tuneable; 1462 int hashsize; 1463 1464 tcp_reass_global_init(); 1465 1466 /* XXX virtualize those below? */ 1467 tcp_delacktime = TCPTV_DELACK; 1468 tcp_keepinit = TCPTV_KEEP_INIT; 1469 tcp_keepidle = TCPTV_KEEP_IDLE; 1470 tcp_keepintvl = TCPTV_KEEPINTVL; 1471 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1472 tcp_rexmit_initial = TCPTV_RTOBASE; 1473 if (tcp_rexmit_initial < 1) 1474 tcp_rexmit_initial = 1; 1475 tcp_rexmit_min = TCPTV_MIN; 1476 if (tcp_rexmit_min < 1) 1477 tcp_rexmit_min = 1; 1478 tcp_persmin = TCPTV_PERSMIN; 1479 tcp_persmax = TCPTV_PERSMAX; 1480 tcp_rexmit_slop = TCPTV_CPU_VAR; 1481 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1482 1483 /* Setup the tcp function block list */ 1484 TAILQ_INIT(&t_functions); 1485 rw_init(&tcp_function_lock, "tcp_func_lock"); 1486 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1487 sx_init(&tcpoudp_lock, "TCP over UDP configuration"); 1488 #ifdef TCP_BLACKBOX 1489 /* Initialize the TCP logging data. */ 1490 tcp_log_init(); 1491 #endif 1492 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1493 1494 if (tcp_soreceive_stream) { 1495 #ifdef INET 1496 tcp_protosw.pr_soreceive = soreceive_stream; 1497 #endif 1498 #ifdef INET6 1499 tcp6_protosw.pr_soreceive = soreceive_stream; 1500 #endif /* INET6 */ 1501 } 1502 1503 #ifdef INET6 1504 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1505 #else /* INET6 */ 1506 max_protohdr_grow(sizeof(struct tcpiphdr)); 1507 #endif /* INET6 */ 1508 1509 ISN_LOCK_INIT(); 1510 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1511 SHUTDOWN_PRI_DEFAULT); 1512 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1513 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1514 1515 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1516 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1517 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1518 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1519 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1520 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1521 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1522 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1523 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1524 #ifdef TCPPCAP 1525 tcp_pcap_init(); 1526 #endif 1527 1528 hashsize = TCBHASHSIZE; 1529 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1530 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1531 if (hashsize == 0) { 1532 /* 1533 * Auto tune the hash size based on maxsockets. 1534 * A perfect hash would have a 1:1 mapping 1535 * (hashsize = maxsockets) however it's been 1536 * suggested that O(2) average is better. 1537 */ 1538 hashsize = maketcp_hashsize(maxsockets / 4); 1539 /* 1540 * Our historical default is 512, 1541 * do not autotune lower than this. 1542 */ 1543 if (hashsize < 512) 1544 hashsize = 512; 1545 if (bootverbose) 1546 printf("%s: %s auto tuned to %d\n", __func__, 1547 tcbhash_tuneable, hashsize); 1548 } 1549 /* 1550 * We require a hashsize to be a power of two. 1551 * Previously if it was not a power of two we would just reset it 1552 * back to 512, which could be a nasty surprise if you did not notice 1553 * the error message. 1554 * Instead what we do is clip it to the closest power of two lower 1555 * than the specified hash value. 1556 */ 1557 if (!powerof2(hashsize)) { 1558 int oldhashsize = hashsize; 1559 1560 hashsize = maketcp_hashsize(hashsize); 1561 /* prevent absurdly low value */ 1562 if (hashsize < 16) 1563 hashsize = 16; 1564 printf("%s: WARNING: TCB hash size not a power of 2, " 1565 "clipped from %d to %d.\n", __func__, oldhashsize, 1566 hashsize); 1567 } 1568 tcp_tcbhashsize = hashsize; 1569 1570 #ifdef INET 1571 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1572 #endif 1573 #ifdef INET6 1574 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1575 #endif 1576 } 1577 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1578 1579 #ifdef VIMAGE 1580 static void 1581 tcp_destroy(void *unused __unused) 1582 { 1583 int n; 1584 #ifdef TCP_HHOOK 1585 int error; 1586 #endif 1587 1588 /* 1589 * All our processes are gone, all our sockets should be cleaned 1590 * up, which means, we should be past the tcp_discardcb() calls. 1591 * Sleep to let all tcpcb timers really disappear and cleanup. 1592 */ 1593 for (;;) { 1594 INP_INFO_WLOCK(&V_tcbinfo); 1595 n = V_tcbinfo.ipi_count; 1596 INP_INFO_WUNLOCK(&V_tcbinfo); 1597 if (n == 0) 1598 break; 1599 pause("tcpdes", hz / 10); 1600 } 1601 tcp_hc_destroy(); 1602 syncache_destroy(); 1603 in_pcbinfo_destroy(&V_tcbinfo); 1604 /* tcp_discardcb() clears the sack_holes up. */ 1605 uma_zdestroy(V_sack_hole_zone); 1606 1607 /* 1608 * Cannot free the zone until all tcpcbs are released as we attach 1609 * the allocations to them. 1610 */ 1611 tcp_fastopen_destroy(); 1612 1613 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1614 VNET_PCPUSTAT_FREE(tcpstat); 1615 1616 #ifdef TCP_HHOOK 1617 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1618 if (error != 0) { 1619 printf("%s: WARNING: unable to deregister helper hook " 1620 "type=%d, id=%d: error %d returned\n", __func__, 1621 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1622 } 1623 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1624 if (error != 0) { 1625 printf("%s: WARNING: unable to deregister helper hook " 1626 "type=%d, id=%d: error %d returned\n", __func__, 1627 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1628 } 1629 #endif 1630 } 1631 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1632 #endif 1633 1634 void 1635 tcp_fini(void *xtp) 1636 { 1637 1638 } 1639 1640 /* 1641 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1642 * tcp_template used to store this data in mbufs, but we now recopy it out 1643 * of the tcpcb each time to conserve mbufs. 1644 */ 1645 void 1646 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1647 { 1648 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1649 1650 INP_WLOCK_ASSERT(inp); 1651 1652 #ifdef INET6 1653 if ((inp->inp_vflag & INP_IPV6) != 0) { 1654 struct ip6_hdr *ip6; 1655 1656 ip6 = (struct ip6_hdr *)ip_ptr; 1657 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1658 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1659 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1660 (IPV6_VERSION & IPV6_VERSION_MASK); 1661 if (port == 0) 1662 ip6->ip6_nxt = IPPROTO_TCP; 1663 else 1664 ip6->ip6_nxt = IPPROTO_UDP; 1665 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1666 ip6->ip6_src = inp->in6p_laddr; 1667 ip6->ip6_dst = inp->in6p_faddr; 1668 } 1669 #endif /* INET6 */ 1670 #if defined(INET6) && defined(INET) 1671 else 1672 #endif 1673 #ifdef INET 1674 { 1675 struct ip *ip; 1676 1677 ip = (struct ip *)ip_ptr; 1678 ip->ip_v = IPVERSION; 1679 ip->ip_hl = 5; 1680 ip->ip_tos = inp->inp_ip_tos; 1681 ip->ip_len = 0; 1682 ip->ip_id = 0; 1683 ip->ip_off = 0; 1684 ip->ip_ttl = inp->inp_ip_ttl; 1685 ip->ip_sum = 0; 1686 if (port == 0) 1687 ip->ip_p = IPPROTO_TCP; 1688 else 1689 ip->ip_p = IPPROTO_UDP; 1690 ip->ip_src = inp->inp_laddr; 1691 ip->ip_dst = inp->inp_faddr; 1692 } 1693 #endif /* INET */ 1694 th->th_sport = inp->inp_lport; 1695 th->th_dport = inp->inp_fport; 1696 th->th_seq = 0; 1697 th->th_ack = 0; 1698 th->th_off = 5; 1699 tcp_set_flags(th, 0); 1700 th->th_win = 0; 1701 th->th_urp = 0; 1702 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1703 } 1704 1705 /* 1706 * Create template to be used to send tcp packets on a connection. 1707 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1708 * use for this function is in keepalives, which use tcp_respond. 1709 */ 1710 struct tcptemp * 1711 tcpip_maketemplate(struct inpcb *inp) 1712 { 1713 struct tcptemp *t; 1714 1715 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1716 if (t == NULL) 1717 return (NULL); 1718 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1719 return (t); 1720 } 1721 1722 /* 1723 * Send a single message to the TCP at address specified by 1724 * the given TCP/IP header. If m == NULL, then we make a copy 1725 * of the tcpiphdr at th and send directly to the addressed host. 1726 * This is used to force keep alive messages out using the TCP 1727 * template for a connection. If flags are given then we send 1728 * a message back to the TCP which originated the segment th, 1729 * and discard the mbuf containing it and any other attached mbufs. 1730 * 1731 * In any case the ack and sequence number of the transmitted 1732 * segment are as specified by the parameters. 1733 * 1734 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1735 */ 1736 void 1737 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1738 tcp_seq ack, tcp_seq seq, uint16_t flags) 1739 { 1740 struct tcpopt to; 1741 struct inpcb *inp; 1742 struct ip *ip; 1743 struct mbuf *optm; 1744 struct udphdr *uh = NULL; 1745 struct tcphdr *nth; 1746 struct tcp_log_buffer *lgb; 1747 u_char *optp; 1748 #ifdef INET6 1749 struct ip6_hdr *ip6; 1750 int isipv6; 1751 #endif /* INET6 */ 1752 int optlen, tlen, win, ulen; 1753 int ect = 0; 1754 bool incl_opts; 1755 uint16_t port; 1756 int output_ret; 1757 #ifdef INVARIANTS 1758 int thflags = tcp_get_flags(th); 1759 #endif 1760 1761 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1762 NET_EPOCH_ASSERT(); 1763 1764 #ifdef INET6 1765 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1766 ip6 = ipgen; 1767 #endif /* INET6 */ 1768 ip = ipgen; 1769 1770 if (tp != NULL) { 1771 inp = tptoinpcb(tp); 1772 INP_LOCK_ASSERT(inp); 1773 } else 1774 inp = NULL; 1775 1776 if (m != NULL) { 1777 #ifdef INET6 1778 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1779 port = m->m_pkthdr.tcp_tun_port; 1780 else 1781 #endif 1782 if (ip && (ip->ip_p == IPPROTO_UDP)) 1783 port = m->m_pkthdr.tcp_tun_port; 1784 else 1785 port = 0; 1786 } else 1787 port = tp->t_port; 1788 1789 incl_opts = false; 1790 win = 0; 1791 if (tp != NULL) { 1792 if (!(flags & TH_RST)) { 1793 win = sbspace(&inp->inp_socket->so_rcv); 1794 if (win > TCP_MAXWIN << tp->rcv_scale) 1795 win = TCP_MAXWIN << tp->rcv_scale; 1796 } 1797 if ((tp->t_flags & TF_NOOPT) == 0) 1798 incl_opts = true; 1799 } 1800 if (m == NULL) { 1801 m = m_gethdr(M_NOWAIT, MT_DATA); 1802 if (m == NULL) 1803 return; 1804 m->m_data += max_linkhdr; 1805 #ifdef INET6 1806 if (isipv6) { 1807 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1808 sizeof(struct ip6_hdr)); 1809 ip6 = mtod(m, struct ip6_hdr *); 1810 nth = (struct tcphdr *)(ip6 + 1); 1811 if (port) { 1812 /* Insert a UDP header */ 1813 uh = (struct udphdr *)nth; 1814 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1815 uh->uh_dport = port; 1816 nth = (struct tcphdr *)(uh + 1); 1817 } 1818 } else 1819 #endif /* INET6 */ 1820 { 1821 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1822 ip = mtod(m, struct ip *); 1823 nth = (struct tcphdr *)(ip + 1); 1824 if (port) { 1825 /* Insert a UDP header */ 1826 uh = (struct udphdr *)nth; 1827 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1828 uh->uh_dport = port; 1829 nth = (struct tcphdr *)(uh + 1); 1830 } 1831 } 1832 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1833 flags = TH_ACK; 1834 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1835 struct mbuf *n; 1836 1837 /* Can't reuse 'm', allocate a new mbuf. */ 1838 n = m_gethdr(M_NOWAIT, MT_DATA); 1839 if (n == NULL) { 1840 m_freem(m); 1841 return; 1842 } 1843 1844 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1845 m_freem(m); 1846 m_freem(n); 1847 return; 1848 } 1849 1850 n->m_data += max_linkhdr; 1851 /* m_len is set later */ 1852 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1853 #ifdef INET6 1854 if (isipv6) { 1855 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1856 sizeof(struct ip6_hdr)); 1857 ip6 = mtod(n, struct ip6_hdr *); 1858 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1859 nth = (struct tcphdr *)(ip6 + 1); 1860 if (port) { 1861 /* Insert a UDP header */ 1862 uh = (struct udphdr *)nth; 1863 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1864 uh->uh_dport = port; 1865 nth = (struct tcphdr *)(uh + 1); 1866 } 1867 } else 1868 #endif /* INET6 */ 1869 { 1870 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1871 ip = mtod(n, struct ip *); 1872 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1873 nth = (struct tcphdr *)(ip + 1); 1874 if (port) { 1875 /* Insert a UDP header */ 1876 uh = (struct udphdr *)nth; 1877 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1878 uh->uh_dport = port; 1879 nth = (struct tcphdr *)(uh + 1); 1880 } 1881 } 1882 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1883 xchg(nth->th_dport, nth->th_sport, uint16_t); 1884 th = nth; 1885 m_freem(m); 1886 m = n; 1887 } else { 1888 /* 1889 * reuse the mbuf. 1890 * XXX MRT We inherit the FIB, which is lucky. 1891 */ 1892 m_freem(m->m_next); 1893 m->m_next = NULL; 1894 m->m_data = (caddr_t)ipgen; 1895 /* m_len is set later */ 1896 #ifdef INET6 1897 if (isipv6) { 1898 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1899 nth = (struct tcphdr *)(ip6 + 1); 1900 } else 1901 #endif /* INET6 */ 1902 { 1903 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1904 nth = (struct tcphdr *)(ip + 1); 1905 } 1906 if (th != nth) { 1907 /* 1908 * this is usually a case when an extension header 1909 * exists between the IPv6 header and the 1910 * TCP header. 1911 */ 1912 nth->th_sport = th->th_sport; 1913 nth->th_dport = th->th_dport; 1914 } 1915 xchg(nth->th_dport, nth->th_sport, uint16_t); 1916 #undef xchg 1917 } 1918 tlen = 0; 1919 #ifdef INET6 1920 if (isipv6) 1921 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1922 #endif 1923 #if defined(INET) && defined(INET6) 1924 else 1925 #endif 1926 #ifdef INET 1927 tlen = sizeof (struct tcpiphdr); 1928 #endif 1929 if (port) 1930 tlen += sizeof (struct udphdr); 1931 #ifdef INVARIANTS 1932 m->m_len = 0; 1933 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1934 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1935 m, tlen, (long)M_TRAILINGSPACE(m))); 1936 #endif 1937 m->m_len = tlen; 1938 to.to_flags = 0; 1939 if (incl_opts) { 1940 ect = tcp_ecn_output_established(tp, &flags, 0, false); 1941 /* Make sure we have room. */ 1942 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1943 m->m_next = m_get(M_NOWAIT, MT_DATA); 1944 if (m->m_next) { 1945 optp = mtod(m->m_next, u_char *); 1946 optm = m->m_next; 1947 } else 1948 incl_opts = false; 1949 } else { 1950 optp = (u_char *) (nth + 1); 1951 optm = m; 1952 } 1953 } 1954 if (incl_opts) { 1955 /* Timestamps. */ 1956 if (tp->t_flags & TF_RCVD_TSTMP) { 1957 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1958 to.to_tsecr = tp->ts_recent; 1959 to.to_flags |= TOF_TS; 1960 } 1961 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1962 /* TCP-MD5 (RFC2385). */ 1963 if (tp->t_flags & TF_SIGNATURE) 1964 to.to_flags |= TOF_SIGNATURE; 1965 #endif 1966 /* Add the options. */ 1967 tlen += optlen = tcp_addoptions(&to, optp); 1968 1969 /* Update m_len in the correct mbuf. */ 1970 optm->m_len += optlen; 1971 } else 1972 optlen = 0; 1973 #ifdef INET6 1974 if (isipv6) { 1975 if (uh) { 1976 ulen = tlen - sizeof(struct ip6_hdr); 1977 uh->uh_ulen = htons(ulen); 1978 } 1979 ip6->ip6_flow = htonl(ect << 20); 1980 ip6->ip6_vfc = IPV6_VERSION; 1981 if (port) 1982 ip6->ip6_nxt = IPPROTO_UDP; 1983 else 1984 ip6->ip6_nxt = IPPROTO_TCP; 1985 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1986 } 1987 #endif 1988 #if defined(INET) && defined(INET6) 1989 else 1990 #endif 1991 #ifdef INET 1992 { 1993 if (uh) { 1994 ulen = tlen - sizeof(struct ip); 1995 uh->uh_ulen = htons(ulen); 1996 } 1997 ip->ip_tos = ect; 1998 ip->ip_len = htons(tlen); 1999 ip->ip_ttl = V_ip_defttl; 2000 if (port) { 2001 ip->ip_p = IPPROTO_UDP; 2002 } else { 2003 ip->ip_p = IPPROTO_TCP; 2004 } 2005 if (V_path_mtu_discovery) 2006 ip->ip_off |= htons(IP_DF); 2007 } 2008 #endif 2009 m->m_pkthdr.len = tlen; 2010 m->m_pkthdr.rcvif = NULL; 2011 #ifdef MAC 2012 if (inp != NULL) { 2013 /* 2014 * Packet is associated with a socket, so allow the 2015 * label of the response to reflect the socket label. 2016 */ 2017 INP_LOCK_ASSERT(inp); 2018 mac_inpcb_create_mbuf(inp, m); 2019 } else { 2020 /* 2021 * Packet is not associated with a socket, so possibly 2022 * update the label in place. 2023 */ 2024 mac_netinet_tcp_reply(m); 2025 } 2026 #endif 2027 nth->th_seq = htonl(seq); 2028 nth->th_ack = htonl(ack); 2029 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2030 tcp_set_flags(nth, flags); 2031 if (tp != NULL) 2032 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2033 else 2034 nth->th_win = htons((u_short)win); 2035 nth->th_urp = 0; 2036 2037 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2038 if (to.to_flags & TOF_SIGNATURE) { 2039 if (!TCPMD5_ENABLED() || 2040 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2041 m_freem(m); 2042 return; 2043 } 2044 } 2045 #endif 2046 2047 #ifdef INET6 2048 if (isipv6) { 2049 if (port) { 2050 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2051 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2052 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2053 nth->th_sum = 0; 2054 } else { 2055 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2056 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2057 nth->th_sum = in6_cksum_pseudo(ip6, 2058 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2059 } 2060 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 2061 } 2062 #endif /* INET6 */ 2063 #if defined(INET6) && defined(INET) 2064 else 2065 #endif 2066 #ifdef INET 2067 { 2068 if (port) { 2069 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2070 htons(ulen + IPPROTO_UDP)); 2071 m->m_pkthdr.csum_flags = CSUM_UDP; 2072 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2073 nth->th_sum = 0; 2074 } else { 2075 m->m_pkthdr.csum_flags = CSUM_TCP; 2076 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2077 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2078 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2079 } 2080 } 2081 #endif /* INET */ 2082 TCP_PROBE3(debug__output, tp, th, m); 2083 if (flags & TH_RST) 2084 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2085 lgb = NULL; 2086 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2087 if (INP_WLOCKED(inp)) { 2088 union tcp_log_stackspecific log; 2089 struct timeval tv; 2090 2091 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2092 log.u_bbr.inhpts = inp->inp_in_hpts; 2093 log.u_bbr.flex8 = 4; 2094 log.u_bbr.pkts_out = tp->t_maxseg; 2095 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2096 log.u_bbr.delivered = 0; 2097 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2098 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2099 } else { 2100 /* 2101 * We can not log the packet, since we only own the 2102 * read lock, but a write lock is needed. The read lock 2103 * is not upgraded to a write lock, since only getting 2104 * the read lock was done intentionally to improve the 2105 * handling of SYN flooding attacks. 2106 * This happens only for pure SYN segments received in 2107 * the initial CLOSED state, or received in a more 2108 * advanced state than listen and the UDP encapsulation 2109 * port is unexpected. 2110 * The incoming SYN segments do not really belong to 2111 * the TCP connection and the handling does not change 2112 * the state of the TCP connection. Therefore, the 2113 * sending of the RST segments is not logged. Please 2114 * note that also the incoming SYN segments are not 2115 * logged. 2116 * 2117 * The following code ensures that the above description 2118 * is and stays correct. 2119 */ 2120 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2121 (tp->t_state == TCPS_CLOSED || 2122 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2123 ("%s: Logging of TCP segment with flags 0x%b and " 2124 "UDP encapsulation port %u skipped in state %s", 2125 __func__, thflags, PRINT_TH_FLAGS, 2126 ntohs(port), tcpstates[tp->t_state])); 2127 } 2128 } 2129 2130 if (flags & TH_ACK) 2131 TCPSTAT_INC(tcps_sndacks); 2132 else if (flags & (TH_SYN|TH_FIN|TH_RST)) 2133 TCPSTAT_INC(tcps_sndctrl); 2134 TCPSTAT_INC(tcps_sndtotal); 2135 2136 #ifdef INET6 2137 if (isipv6) { 2138 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2139 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2140 } 2141 #endif /* INET6 */ 2142 #if defined(INET) && defined(INET6) 2143 else 2144 #endif 2145 #ifdef INET 2146 { 2147 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2148 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2149 } 2150 #endif 2151 if (lgb != NULL) 2152 lgb->tlb_errno = output_ret; 2153 } 2154 2155 /* 2156 * Create a new TCP control block, making an empty reassembly queue and hooking 2157 * it to the argument protocol control block. The `inp' parameter must have 2158 * come from the zone allocator set up by tcpcbstor declaration. 2159 */ 2160 struct tcpcb * 2161 tcp_newtcpcb(struct inpcb *inp) 2162 { 2163 struct tcpcb *tp = intotcpcb(inp); 2164 #ifdef INET6 2165 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2166 #endif /* INET6 */ 2167 2168 /* 2169 * Historically allocation was done with M_ZERO. There is a lot of 2170 * code that rely on that. For now take safe approach and zero whole 2171 * tcpcb. This definitely can be optimized. 2172 */ 2173 bzero(&tp->t_start_zero, t_zero_size); 2174 2175 /* Initialise cc_var struct for this tcpcb. */ 2176 tp->t_ccv.type = IPPROTO_TCP; 2177 tp->t_ccv.ccvc.tcp = tp; 2178 rw_rlock(&tcp_function_lock); 2179 tp->t_fb = tcp_func_set_ptr; 2180 refcount_acquire(&tp->t_fb->tfb_refcnt); 2181 rw_runlock(&tcp_function_lock); 2182 /* 2183 * Use the current system default CC algorithm. 2184 */ 2185 cc_attach(tp, CC_DEFAULT_ALGO()); 2186 2187 if (CC_ALGO(tp)->cb_init != NULL) 2188 if (CC_ALGO(tp)->cb_init(&tp->t_ccv, NULL) > 0) { 2189 cc_detach(tp); 2190 if (tp->t_fb->tfb_tcp_fb_fini) 2191 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2192 refcount_release(&tp->t_fb->tfb_refcnt); 2193 return (NULL); 2194 } 2195 2196 #ifdef TCP_HHOOK 2197 if (khelp_init_osd(HELPER_CLASS_TCP, &tp->t_osd)) { 2198 if (tp->t_fb->tfb_tcp_fb_fini) 2199 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2200 refcount_release(&tp->t_fb->tfb_refcnt); 2201 return (NULL); 2202 } 2203 #endif 2204 2205 TAILQ_INIT(&tp->t_segq); 2206 tp->t_maxseg = 2207 #ifdef INET6 2208 isipv6 ? V_tcp_v6mssdflt : 2209 #endif /* INET6 */ 2210 V_tcp_mssdflt; 2211 2212 callout_init_rw(&tp->t_callout, &inp->inp_lock, CALLOUT_RETURNUNLOCKED); 2213 for (int i = 0; i < TT_N; i++) 2214 tp->t_timers[i] = SBT_MAX; 2215 2216 switch (V_tcp_do_rfc1323) { 2217 case 0: 2218 break; 2219 default: 2220 case 1: 2221 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2222 break; 2223 case 2: 2224 tp->t_flags = TF_REQ_SCALE; 2225 break; 2226 case 3: 2227 tp->t_flags = TF_REQ_TSTMP; 2228 break; 2229 } 2230 if (V_tcp_do_sack) 2231 tp->t_flags |= TF_SACK_PERMIT; 2232 TAILQ_INIT(&tp->snd_holes); 2233 2234 /* 2235 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2236 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2237 * reasonable initial retransmit time. 2238 */ 2239 tp->t_srtt = TCPTV_SRTTBASE; 2240 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2241 tp->t_rttmin = tcp_rexmit_min; 2242 tp->t_rxtcur = tcp_rexmit_initial; 2243 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2244 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2245 tp->t_rcvtime = ticks; 2246 /* 2247 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2248 * because the socket may be bound to an IPv6 wildcard address, 2249 * which may match an IPv4-mapped IPv6 address. 2250 */ 2251 inp->inp_ip_ttl = V_ip_defttl; 2252 #ifdef TCPHPTS 2253 /* 2254 * If using hpts lets drop a random number in so 2255 * not all new connections fall on the same CPU. 2256 */ 2257 inp->inp_hpts_cpu = hpts_random_cpu(inp); 2258 #endif 2259 #ifdef TCPPCAP 2260 /* 2261 * Init the TCP PCAP queues. 2262 */ 2263 tcp_pcap_tcpcb_init(tp); 2264 #endif 2265 #ifdef TCP_BLACKBOX 2266 /* Initialize the per-TCPCB log data. */ 2267 tcp_log_tcpcbinit(tp); 2268 #endif 2269 tp->t_pacing_rate = -1; 2270 if (tp->t_fb->tfb_tcp_fb_init) { 2271 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2272 refcount_release(&tp->t_fb->tfb_refcnt); 2273 return (NULL); 2274 } 2275 } 2276 #ifdef STATS 2277 if (V_tcp_perconn_stats_enable == 1) 2278 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2279 #endif 2280 if (V_tcp_do_lrd) 2281 tp->t_flags |= TF_LRD; 2282 2283 return (tp); 2284 } 2285 2286 /* 2287 * Drop a TCP connection, reporting 2288 * the specified error. If connection is synchronized, 2289 * then send a RST to peer. 2290 */ 2291 struct tcpcb * 2292 tcp_drop(struct tcpcb *tp, int errno) 2293 { 2294 struct socket *so = tptosocket(tp); 2295 2296 NET_EPOCH_ASSERT(); 2297 INP_WLOCK_ASSERT(tptoinpcb(tp)); 2298 2299 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2300 tcp_state_change(tp, TCPS_CLOSED); 2301 /* Don't use tcp_output() here due to possible recursion. */ 2302 (void)tcp_output_nodrop(tp); 2303 TCPSTAT_INC(tcps_drops); 2304 } else 2305 TCPSTAT_INC(tcps_conndrops); 2306 if (errno == ETIMEDOUT && tp->t_softerror) 2307 errno = tp->t_softerror; 2308 so->so_error = errno; 2309 return (tcp_close(tp)); 2310 } 2311 2312 void 2313 tcp_discardcb(struct tcpcb *tp) 2314 { 2315 struct inpcb *inp = tptoinpcb(tp); 2316 struct socket *so = tptosocket(tp); 2317 #ifdef INET6 2318 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2319 #endif 2320 2321 INP_WLOCK_ASSERT(inp); 2322 2323 tcp_timer_stop(tp); 2324 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2325 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2326 } 2327 2328 /* free the reassembly queue, if any */ 2329 tcp_reass_flush(tp); 2330 2331 #ifdef TCP_OFFLOAD 2332 /* Disconnect offload device, if any. */ 2333 if (tp->t_flags & TF_TOE) 2334 tcp_offload_detach(tp); 2335 #endif 2336 2337 tcp_free_sackholes(tp); 2338 2339 #ifdef TCPPCAP 2340 /* Free the TCP PCAP queues. */ 2341 tcp_pcap_drain(&(tp->t_inpkts)); 2342 tcp_pcap_drain(&(tp->t_outpkts)); 2343 #endif 2344 2345 /* Allow the CC algorithm to clean up after itself. */ 2346 if (CC_ALGO(tp)->cb_destroy != NULL) 2347 CC_ALGO(tp)->cb_destroy(&tp->t_ccv); 2348 CC_DATA(tp) = NULL; 2349 /* Detach from the CC algorithm */ 2350 cc_detach(tp); 2351 2352 #ifdef TCP_HHOOK 2353 khelp_destroy_osd(&tp->t_osd); 2354 #endif 2355 #ifdef STATS 2356 stats_blob_destroy(tp->t_stats); 2357 #endif 2358 2359 CC_ALGO(tp) = NULL; 2360 2361 #ifdef TCP_BLACKBOX 2362 tcp_log_tcpcbfini(tp); 2363 #endif 2364 TCPSTATES_DEC(tp->t_state); 2365 if (tp->t_fb->tfb_tcp_fb_fini) 2366 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2367 2368 /* 2369 * If we got enough samples through the srtt filter, 2370 * save the rtt and rttvar in the routing entry. 2371 * 'Enough' is arbitrarily defined as 4 rtt samples. 2372 * 4 samples is enough for the srtt filter to converge 2373 * to within enough % of the correct value; fewer samples 2374 * and we could save a bogus rtt. The danger is not high 2375 * as tcp quickly recovers from everything. 2376 * XXX: Works very well but needs some more statistics! 2377 * 2378 * XXXRRS: Updating must be after the stack fini() since 2379 * that may be converting some internal representation of 2380 * say srtt etc into the general one used by other stacks. 2381 * Lets also at least protect against the so being NULL 2382 * as RW stated below. 2383 */ 2384 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2385 struct hc_metrics_lite metrics; 2386 uint32_t ssthresh; 2387 2388 bzero(&metrics, sizeof(metrics)); 2389 /* 2390 * Update the ssthresh always when the conditions below 2391 * are satisfied. This gives us better new start value 2392 * for the congestion avoidance for new connections. 2393 * ssthresh is only set if packet loss occurred on a session. 2394 * 2395 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2396 * being torn down. Ideally this code would not use 'so'. 2397 */ 2398 ssthresh = tp->snd_ssthresh; 2399 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2400 /* 2401 * convert the limit from user data bytes to 2402 * packets then to packet data bytes. 2403 */ 2404 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2405 if (ssthresh < 2) 2406 ssthresh = 2; 2407 ssthresh *= (tp->t_maxseg + 2408 #ifdef INET6 2409 (isipv6 ? sizeof (struct ip6_hdr) + 2410 sizeof (struct tcphdr) : 2411 #endif 2412 sizeof (struct tcpiphdr) 2413 #ifdef INET6 2414 ) 2415 #endif 2416 ); 2417 } else 2418 ssthresh = 0; 2419 metrics.rmx_ssthresh = ssthresh; 2420 2421 metrics.rmx_rtt = tp->t_srtt; 2422 metrics.rmx_rttvar = tp->t_rttvar; 2423 metrics.rmx_cwnd = tp->snd_cwnd; 2424 metrics.rmx_sendpipe = 0; 2425 metrics.rmx_recvpipe = 0; 2426 2427 tcp_hc_update(&inp->inp_inc, &metrics); 2428 } 2429 2430 refcount_release(&tp->t_fb->tfb_refcnt); 2431 } 2432 2433 /* 2434 * Attempt to close a TCP control block, marking it as dropped, and freeing 2435 * the socket if we hold the only reference. 2436 */ 2437 struct tcpcb * 2438 tcp_close(struct tcpcb *tp) 2439 { 2440 struct inpcb *inp = tptoinpcb(tp); 2441 struct socket *so = tptosocket(tp); 2442 2443 INP_WLOCK_ASSERT(inp); 2444 2445 #ifdef TCP_OFFLOAD 2446 if (tp->t_state == TCPS_LISTEN) 2447 tcp_offload_listen_stop(tp); 2448 #endif 2449 /* 2450 * This releases the TFO pending counter resource for TFO listen 2451 * sockets as well as passively-created TFO sockets that transition 2452 * from SYN_RECEIVED to CLOSED. 2453 */ 2454 if (tp->t_tfo_pending) { 2455 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2456 tp->t_tfo_pending = NULL; 2457 } 2458 #ifdef TCPHPTS 2459 tcp_hpts_remove(inp); 2460 #endif 2461 in_pcbdrop(inp); 2462 TCPSTAT_INC(tcps_closed); 2463 if (tp->t_state != TCPS_CLOSED) 2464 tcp_state_change(tp, TCPS_CLOSED); 2465 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2466 soisdisconnected(so); 2467 if (inp->inp_flags & INP_SOCKREF) { 2468 inp->inp_flags &= ~INP_SOCKREF; 2469 INP_WUNLOCK(inp); 2470 sorele(so); 2471 return (NULL); 2472 } 2473 return (tp); 2474 } 2475 2476 /* 2477 * Notify a tcp user of an asynchronous error; 2478 * store error as soft error, but wake up user 2479 * (for now, won't do anything until can select for soft error). 2480 * 2481 * Do not wake up user since there currently is no mechanism for 2482 * reporting soft errors (yet - a kqueue filter may be added). 2483 */ 2484 static struct inpcb * 2485 tcp_notify(struct inpcb *inp, int error) 2486 { 2487 struct tcpcb *tp; 2488 2489 INP_WLOCK_ASSERT(inp); 2490 2491 tp = intotcpcb(inp); 2492 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2493 2494 /* 2495 * Ignore some errors if we are hooked up. 2496 * If connection hasn't completed, has retransmitted several times, 2497 * and receives a second error, give up now. This is better 2498 * than waiting a long time to establish a connection that 2499 * can never complete. 2500 */ 2501 if (tp->t_state == TCPS_ESTABLISHED && 2502 (error == EHOSTUNREACH || error == ENETUNREACH || 2503 error == EHOSTDOWN)) { 2504 if (inp->inp_route.ro_nh) { 2505 NH_FREE(inp->inp_route.ro_nh); 2506 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2507 } 2508 return (inp); 2509 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2510 tp->t_softerror) { 2511 tp = tcp_drop(tp, error); 2512 if (tp != NULL) 2513 return (inp); 2514 else 2515 return (NULL); 2516 } else { 2517 tp->t_softerror = error; 2518 return (inp); 2519 } 2520 #if 0 2521 wakeup( &so->so_timeo); 2522 sorwakeup(so); 2523 sowwakeup(so); 2524 #endif 2525 } 2526 2527 static int 2528 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2529 { 2530 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2531 INPLOOKUP_RLOCKPCB); 2532 struct xinpgen xig; 2533 struct inpcb *inp; 2534 int error; 2535 2536 if (req->newptr != NULL) 2537 return (EPERM); 2538 2539 if (req->oldptr == NULL) { 2540 int n; 2541 2542 n = V_tcbinfo.ipi_count + 2543 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2544 n += imax(n / 8, 10); 2545 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2546 return (0); 2547 } 2548 2549 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2550 return (error); 2551 2552 bzero(&xig, sizeof(xig)); 2553 xig.xig_len = sizeof xig; 2554 xig.xig_count = V_tcbinfo.ipi_count + 2555 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2556 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2557 xig.xig_sogen = so_gencnt; 2558 error = SYSCTL_OUT(req, &xig, sizeof xig); 2559 if (error) 2560 return (error); 2561 2562 error = syncache_pcblist(req); 2563 if (error) 2564 return (error); 2565 2566 while ((inp = inp_next(&inpi)) != NULL) { 2567 if (inp->inp_gencnt <= xig.xig_gen && 2568 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 2569 struct xtcpcb xt; 2570 2571 tcp_inptoxtp(inp, &xt); 2572 error = SYSCTL_OUT(req, &xt, sizeof xt); 2573 if (error) { 2574 INP_RUNLOCK(inp); 2575 break; 2576 } else 2577 continue; 2578 } 2579 } 2580 2581 if (!error) { 2582 /* 2583 * Give the user an updated idea of our state. 2584 * If the generation differs from what we told 2585 * her before, she knows that something happened 2586 * while we were processing this request, and it 2587 * might be necessary to retry. 2588 */ 2589 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2590 xig.xig_sogen = so_gencnt; 2591 xig.xig_count = V_tcbinfo.ipi_count + 2592 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2593 error = SYSCTL_OUT(req, &xig, sizeof xig); 2594 } 2595 2596 return (error); 2597 } 2598 2599 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2600 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2601 NULL, 0, tcp_pcblist, "S,xtcpcb", 2602 "List of active TCP connections"); 2603 2604 #ifdef INET 2605 static int 2606 tcp_getcred(SYSCTL_HANDLER_ARGS) 2607 { 2608 struct xucred xuc; 2609 struct sockaddr_in addrs[2]; 2610 struct epoch_tracker et; 2611 struct inpcb *inp; 2612 int error; 2613 2614 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2615 if (error) 2616 return (error); 2617 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2618 if (error) 2619 return (error); 2620 NET_EPOCH_ENTER(et); 2621 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2622 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2623 NET_EPOCH_EXIT(et); 2624 if (inp != NULL) { 2625 if (error == 0) 2626 error = cr_canseeinpcb(req->td->td_ucred, inp); 2627 if (error == 0) 2628 cru2x(inp->inp_cred, &xuc); 2629 INP_RUNLOCK(inp); 2630 } else 2631 error = ENOENT; 2632 if (error == 0) 2633 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2634 return (error); 2635 } 2636 2637 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2638 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2639 0, 0, tcp_getcred, "S,xucred", 2640 "Get the xucred of a TCP connection"); 2641 #endif /* INET */ 2642 2643 #ifdef INET6 2644 static int 2645 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2646 { 2647 struct epoch_tracker et; 2648 struct xucred xuc; 2649 struct sockaddr_in6 addrs[2]; 2650 struct inpcb *inp; 2651 int error; 2652 #ifdef INET 2653 int mapped = 0; 2654 #endif 2655 2656 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2657 if (error) 2658 return (error); 2659 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2660 if (error) 2661 return (error); 2662 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2663 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2664 return (error); 2665 } 2666 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2667 #ifdef INET 2668 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2669 mapped = 1; 2670 else 2671 #endif 2672 return (EINVAL); 2673 } 2674 2675 NET_EPOCH_ENTER(et); 2676 #ifdef INET 2677 if (mapped == 1) 2678 inp = in_pcblookup(&V_tcbinfo, 2679 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2680 addrs[1].sin6_port, 2681 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2682 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2683 else 2684 #endif 2685 inp = in6_pcblookup(&V_tcbinfo, 2686 &addrs[1].sin6_addr, addrs[1].sin6_port, 2687 &addrs[0].sin6_addr, addrs[0].sin6_port, 2688 INPLOOKUP_RLOCKPCB, NULL); 2689 NET_EPOCH_EXIT(et); 2690 if (inp != NULL) { 2691 if (error == 0) 2692 error = cr_canseeinpcb(req->td->td_ucred, inp); 2693 if (error == 0) 2694 cru2x(inp->inp_cred, &xuc); 2695 INP_RUNLOCK(inp); 2696 } else 2697 error = ENOENT; 2698 if (error == 0) 2699 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2700 return (error); 2701 } 2702 2703 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2704 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2705 0, 0, tcp6_getcred, "S,xucred", 2706 "Get the xucred of a TCP6 connection"); 2707 #endif /* INET6 */ 2708 2709 #ifdef INET 2710 /* Path MTU to try next when a fragmentation-needed message is received. */ 2711 static inline int 2712 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2713 { 2714 int mtu = ntohs(icp->icmp_nextmtu); 2715 2716 /* If no alternative MTU was proposed, try the next smaller one. */ 2717 if (!mtu) 2718 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2719 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2720 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2721 2722 return (mtu); 2723 } 2724 2725 static void 2726 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port) 2727 { 2728 struct ip *ip; 2729 struct tcphdr *th; 2730 struct inpcb *inp; 2731 struct tcpcb *tp; 2732 struct inpcb *(*notify)(struct inpcb *, int); 2733 struct in_conninfo inc; 2734 tcp_seq icmp_tcp_seq; 2735 int errno, mtu; 2736 2737 errno = icmp_errmap(icp); 2738 switch (errno) { 2739 case 0: 2740 return; 2741 case EMSGSIZE: 2742 notify = tcp_mtudisc_notify; 2743 break; 2744 case ECONNREFUSED: 2745 if (V_icmp_may_rst) 2746 notify = tcp_drop_syn_sent; 2747 else 2748 notify = tcp_notify; 2749 break; 2750 case EHOSTUNREACH: 2751 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED) 2752 notify = tcp_drop_syn_sent; 2753 else 2754 notify = tcp_notify; 2755 break; 2756 default: 2757 notify = tcp_notify; 2758 } 2759 2760 ip = &icp->icmp_ip; 2761 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2762 icmp_tcp_seq = th->th_seq; 2763 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src, 2764 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2765 if (inp != NULL) { 2766 tp = intotcpcb(inp); 2767 #ifdef TCP_OFFLOAD 2768 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2769 /* 2770 * MTU discovery for offloaded connections. Let 2771 * the TOE driver verify seq# and process it. 2772 */ 2773 mtu = tcp_next_pmtu(icp, ip); 2774 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2775 goto out; 2776 } 2777 #endif 2778 if (tp->t_port != port) 2779 goto out; 2780 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2781 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2782 if (errno == EMSGSIZE) { 2783 /* 2784 * MTU discovery: we got a needfrag and 2785 * will potentially try a lower MTU. 2786 */ 2787 mtu = tcp_next_pmtu(icp, ip); 2788 2789 /* 2790 * Only process the offered MTU if it 2791 * is smaller than the current one. 2792 */ 2793 if (mtu < tp->t_maxseg + 2794 sizeof(struct tcpiphdr)) { 2795 bzero(&inc, sizeof(inc)); 2796 inc.inc_faddr = ip->ip_dst; 2797 inc.inc_fibnum = 2798 inp->inp_inc.inc_fibnum; 2799 tcp_hc_updatemtu(&inc, mtu); 2800 inp = tcp_mtudisc(inp, mtu); 2801 } 2802 } else 2803 inp = (*notify)(inp, errno); 2804 } 2805 } else { 2806 bzero(&inc, sizeof(inc)); 2807 inc.inc_fport = th->th_dport; 2808 inc.inc_lport = th->th_sport; 2809 inc.inc_faddr = ip->ip_dst; 2810 inc.inc_laddr = ip->ip_src; 2811 syncache_unreach(&inc, icmp_tcp_seq, port); 2812 } 2813 out: 2814 if (inp != NULL) 2815 INP_WUNLOCK(inp); 2816 } 2817 2818 static void 2819 tcp_ctlinput(struct icmp *icmp) 2820 { 2821 tcp_ctlinput_with_port(icmp, htons(0)); 2822 } 2823 2824 static void 2825 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param) 2826 { 2827 /* Its a tunneled TCP over UDP icmp */ 2828 struct icmp *icmp = param.icmp; 2829 struct ip *outer_ip, *inner_ip; 2830 struct udphdr *udp; 2831 struct tcphdr *th, ttemp; 2832 int i_hlen, o_len; 2833 uint16_t port; 2834 2835 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2836 inner_ip = &icmp->icmp_ip; 2837 i_hlen = inner_ip->ip_hl << 2; 2838 o_len = ntohs(outer_ip->ip_len); 2839 if (o_len < 2840 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2841 /* Not enough data present */ 2842 return; 2843 } 2844 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2845 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2846 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2847 return; 2848 } 2849 port = udp->uh_dport; 2850 th = (struct tcphdr *)(udp + 1); 2851 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2852 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2853 /* Now adjust down the size of the outer IP header */ 2854 o_len -= sizeof(struct udphdr); 2855 outer_ip->ip_len = htons(o_len); 2856 /* Now call in to the normal handling code */ 2857 tcp_ctlinput_with_port(icmp, port); 2858 } 2859 #endif /* INET */ 2860 2861 #ifdef INET6 2862 static inline int 2863 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2864 { 2865 int mtu = ntohl(icmp6->icmp6_mtu); 2866 2867 /* 2868 * If no alternative MTU was proposed, or the proposed MTU was too 2869 * small, set to the min. 2870 */ 2871 if (mtu < IPV6_MMTU) 2872 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2873 return (mtu); 2874 } 2875 2876 static void 2877 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port) 2878 { 2879 struct in6_addr *dst; 2880 struct inpcb *(*notify)(struct inpcb *, int); 2881 struct ip6_hdr *ip6; 2882 struct mbuf *m; 2883 struct inpcb *inp; 2884 struct tcpcb *tp; 2885 struct icmp6_hdr *icmp6; 2886 struct in_conninfo inc; 2887 struct tcp_ports { 2888 uint16_t th_sport; 2889 uint16_t th_dport; 2890 } t_ports; 2891 tcp_seq icmp_tcp_seq; 2892 unsigned int mtu; 2893 unsigned int off; 2894 int errno; 2895 2896 icmp6 = ip6cp->ip6c_icmp6; 2897 m = ip6cp->ip6c_m; 2898 ip6 = ip6cp->ip6c_ip6; 2899 off = ip6cp->ip6c_off; 2900 dst = &ip6cp->ip6c_finaldst->sin6_addr; 2901 2902 errno = icmp6_errmap(icmp6); 2903 switch (errno) { 2904 case 0: 2905 return; 2906 case EMSGSIZE: 2907 notify = tcp_mtudisc_notify; 2908 break; 2909 case ECONNREFUSED: 2910 if (V_icmp_may_rst) 2911 notify = tcp_drop_syn_sent; 2912 else 2913 notify = tcp_notify; 2914 break; 2915 case EHOSTUNREACH: 2916 /* 2917 * There are only four ICMPs that may reset connection: 2918 * - administratively prohibited 2919 * - port unreachable 2920 * - time exceeded in transit 2921 * - unknown next header 2922 */ 2923 if (V_icmp_may_rst && 2924 ((icmp6->icmp6_type == ICMP6_DST_UNREACH && 2925 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN || 2926 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) || 2927 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED && 2928 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) || 2929 (icmp6->icmp6_type == ICMP6_PARAM_PROB && 2930 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER))) 2931 notify = tcp_drop_syn_sent; 2932 else 2933 notify = tcp_notify; 2934 break; 2935 default: 2936 notify = tcp_notify; 2937 } 2938 2939 /* Check if we can safely get the ports from the tcp hdr */ 2940 if (m == NULL || 2941 (m->m_pkthdr.len < 2942 (int32_t) (off + sizeof(struct tcp_ports)))) { 2943 return; 2944 } 2945 bzero(&t_ports, sizeof(struct tcp_ports)); 2946 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2947 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2948 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2949 off += sizeof(struct tcp_ports); 2950 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2951 goto out; 2952 } 2953 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2954 if (inp != NULL) { 2955 tp = intotcpcb(inp); 2956 #ifdef TCP_OFFLOAD 2957 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2958 /* MTU discovery for offloaded connections. */ 2959 mtu = tcp6_next_pmtu(icmp6); 2960 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2961 goto out; 2962 } 2963 #endif 2964 if (tp->t_port != port) 2965 goto out; 2966 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2967 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2968 if (errno == EMSGSIZE) { 2969 /* 2970 * MTU discovery: 2971 * If we got a needfrag set the MTU 2972 * in the route to the suggested new 2973 * value (if given) and then notify. 2974 */ 2975 mtu = tcp6_next_pmtu(icmp6); 2976 2977 bzero(&inc, sizeof(inc)); 2978 inc.inc_fibnum = M_GETFIB(m); 2979 inc.inc_flags |= INC_ISIPV6; 2980 inc.inc6_faddr = *dst; 2981 if (in6_setscope(&inc.inc6_faddr, 2982 m->m_pkthdr.rcvif, NULL)) 2983 goto out; 2984 /* 2985 * Only process the offered MTU if it 2986 * is smaller than the current one. 2987 */ 2988 if (mtu < tp->t_maxseg + 2989 sizeof (struct tcphdr) + 2990 sizeof (struct ip6_hdr)) { 2991 tcp_hc_updatemtu(&inc, mtu); 2992 tcp_mtudisc(inp, mtu); 2993 ICMP6STAT_INC(icp6s_pmtuchg); 2994 } 2995 } else 2996 inp = (*notify)(inp, errno); 2997 } 2998 } else { 2999 bzero(&inc, sizeof(inc)); 3000 inc.inc_fibnum = M_GETFIB(m); 3001 inc.inc_flags |= INC_ISIPV6; 3002 inc.inc_fport = t_ports.th_dport; 3003 inc.inc_lport = t_ports.th_sport; 3004 inc.inc6_faddr = *dst; 3005 inc.inc6_laddr = ip6->ip6_src; 3006 syncache_unreach(&inc, icmp_tcp_seq, port); 3007 } 3008 out: 3009 if (inp != NULL) 3010 INP_WUNLOCK(inp); 3011 } 3012 3013 static void 3014 tcp6_ctlinput(struct ip6ctlparam *ctl) 3015 { 3016 tcp6_ctlinput_with_port(ctl, htons(0)); 3017 } 3018 3019 static void 3020 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param) 3021 { 3022 struct ip6ctlparam *ip6cp = param.ip6cp; 3023 struct mbuf *m; 3024 struct udphdr *udp; 3025 uint16_t port; 3026 3027 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3028 if (m == NULL) { 3029 return; 3030 } 3031 udp = mtod(m, struct udphdr *); 3032 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3033 return; 3034 } 3035 port = udp->uh_dport; 3036 m_adj(m, sizeof(struct udphdr)); 3037 if ((m->m_flags & M_PKTHDR) == 0) { 3038 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3039 } 3040 /* Now call in to the normal handling code */ 3041 tcp6_ctlinput_with_port(ip6cp, port); 3042 } 3043 3044 #endif /* INET6 */ 3045 3046 static uint32_t 3047 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3048 { 3049 SIPHASH_CTX ctx; 3050 uint32_t hash[2]; 3051 3052 KASSERT(len >= SIPHASH_KEY_LENGTH, 3053 ("%s: keylen %u too short ", __func__, len)); 3054 SipHash24_Init(&ctx); 3055 SipHash_SetKey(&ctx, (uint8_t *)key); 3056 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3057 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3058 switch (inc->inc_flags & INC_ISIPV6) { 3059 #ifdef INET 3060 case 0: 3061 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3062 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3063 break; 3064 #endif 3065 #ifdef INET6 3066 case INC_ISIPV6: 3067 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3068 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3069 break; 3070 #endif 3071 } 3072 SipHash_Final((uint8_t *)hash, &ctx); 3073 3074 return (hash[0] ^ hash[1]); 3075 } 3076 3077 uint32_t 3078 tcp_new_ts_offset(struct in_conninfo *inc) 3079 { 3080 struct in_conninfo inc_store, *local_inc; 3081 3082 if (!V_tcp_ts_offset_per_conn) { 3083 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3084 inc_store.inc_lport = 0; 3085 inc_store.inc_fport = 0; 3086 local_inc = &inc_store; 3087 } else { 3088 local_inc = inc; 3089 } 3090 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3091 sizeof(V_ts_offset_secret))); 3092 } 3093 3094 /* 3095 * Following is where TCP initial sequence number generation occurs. 3096 * 3097 * There are two places where we must use initial sequence numbers: 3098 * 1. In SYN-ACK packets. 3099 * 2. In SYN packets. 3100 * 3101 * All ISNs for SYN-ACK packets are generated by the syncache. See 3102 * tcp_syncache.c for details. 3103 * 3104 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3105 * depends on this property. In addition, these ISNs should be 3106 * unguessable so as to prevent connection hijacking. To satisfy 3107 * the requirements of this situation, the algorithm outlined in 3108 * RFC 1948 is used, with only small modifications. 3109 * 3110 * Implementation details: 3111 * 3112 * Time is based off the system timer, and is corrected so that it 3113 * increases by one megabyte per second. This allows for proper 3114 * recycling on high speed LANs while still leaving over an hour 3115 * before rollover. 3116 * 3117 * As reading the *exact* system time is too expensive to be done 3118 * whenever setting up a TCP connection, we increment the time 3119 * offset in two ways. First, a small random positive increment 3120 * is added to isn_offset for each connection that is set up. 3121 * Second, the function tcp_isn_tick fires once per clock tick 3122 * and increments isn_offset as necessary so that sequence numbers 3123 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3124 * random positive increments serve only to ensure that the same 3125 * exact sequence number is never sent out twice (as could otherwise 3126 * happen when a port is recycled in less than the system tick 3127 * interval.) 3128 * 3129 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3130 * between seeding of isn_secret. This is normally set to zero, 3131 * as reseeding should not be necessary. 3132 * 3133 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3134 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3135 * general, this means holding an exclusive (write) lock. 3136 */ 3137 3138 #define ISN_BYTES_PER_SECOND 1048576 3139 #define ISN_STATIC_INCREMENT 4096 3140 #define ISN_RANDOM_INCREMENT (4096 - 1) 3141 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3142 3143 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3144 VNET_DEFINE_STATIC(int, isn_last); 3145 VNET_DEFINE_STATIC(int, isn_last_reseed); 3146 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3147 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3148 3149 #define V_isn_secret VNET(isn_secret) 3150 #define V_isn_last VNET(isn_last) 3151 #define V_isn_last_reseed VNET(isn_last_reseed) 3152 #define V_isn_offset VNET(isn_offset) 3153 #define V_isn_offset_old VNET(isn_offset_old) 3154 3155 tcp_seq 3156 tcp_new_isn(struct in_conninfo *inc) 3157 { 3158 tcp_seq new_isn; 3159 u_int32_t projected_offset; 3160 3161 ISN_LOCK(); 3162 /* Seed if this is the first use, reseed if requested. */ 3163 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3164 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3165 < (u_int)ticks))) { 3166 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3167 V_isn_last_reseed = ticks; 3168 } 3169 3170 /* Compute the hash and return the ISN. */ 3171 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3172 sizeof(V_isn_secret)); 3173 V_isn_offset += ISN_STATIC_INCREMENT + 3174 (arc4random() & ISN_RANDOM_INCREMENT); 3175 if (ticks != V_isn_last) { 3176 projected_offset = V_isn_offset_old + 3177 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3178 if (SEQ_GT(projected_offset, V_isn_offset)) 3179 V_isn_offset = projected_offset; 3180 V_isn_offset_old = V_isn_offset; 3181 V_isn_last = ticks; 3182 } 3183 new_isn += V_isn_offset; 3184 ISN_UNLOCK(); 3185 return (new_isn); 3186 } 3187 3188 /* 3189 * When a specific ICMP unreachable message is received and the 3190 * connection state is SYN-SENT, drop the connection. This behavior 3191 * is controlled by the icmp_may_rst sysctl. 3192 */ 3193 static struct inpcb * 3194 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3195 { 3196 struct tcpcb *tp; 3197 3198 NET_EPOCH_ASSERT(); 3199 INP_WLOCK_ASSERT(inp); 3200 3201 tp = intotcpcb(inp); 3202 if (tp->t_state != TCPS_SYN_SENT) 3203 return (inp); 3204 3205 if (IS_FASTOPEN(tp->t_flags)) 3206 tcp_fastopen_disable_path(tp); 3207 3208 tp = tcp_drop(tp, errno); 3209 if (tp != NULL) 3210 return (inp); 3211 else 3212 return (NULL); 3213 } 3214 3215 /* 3216 * When `need fragmentation' ICMP is received, update our idea of the MSS 3217 * based on the new value. Also nudge TCP to send something, since we 3218 * know the packet we just sent was dropped. 3219 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3220 */ 3221 static struct inpcb * 3222 tcp_mtudisc_notify(struct inpcb *inp, int error) 3223 { 3224 3225 return (tcp_mtudisc(inp, -1)); 3226 } 3227 3228 static struct inpcb * 3229 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3230 { 3231 struct tcpcb *tp; 3232 struct socket *so; 3233 3234 INP_WLOCK_ASSERT(inp); 3235 3236 tp = intotcpcb(inp); 3237 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3238 3239 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3240 3241 so = inp->inp_socket; 3242 SOCKBUF_LOCK(&so->so_snd); 3243 /* If the mss is larger than the socket buffer, decrease the mss. */ 3244 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3245 tp->t_maxseg = so->so_snd.sb_hiwat; 3246 SOCKBUF_UNLOCK(&so->so_snd); 3247 3248 TCPSTAT_INC(tcps_mturesent); 3249 tp->t_rtttime = 0; 3250 tp->snd_nxt = tp->snd_una; 3251 tcp_free_sackholes(tp); 3252 tp->snd_recover = tp->snd_max; 3253 if (tp->t_flags & TF_SACK_PERMIT) 3254 EXIT_FASTRECOVERY(tp->t_flags); 3255 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3256 /* 3257 * Conceptually the snd_nxt setting 3258 * and freeing sack holes should 3259 * be done by the default stacks 3260 * own tfb_tcp_mtu_chg(). 3261 */ 3262 tp->t_fb->tfb_tcp_mtu_chg(tp); 3263 } 3264 if (tcp_output(tp) < 0) 3265 return (NULL); 3266 else 3267 return (inp); 3268 } 3269 3270 #ifdef INET 3271 /* 3272 * Look-up the routing entry to the peer of this inpcb. If no route 3273 * is found and it cannot be allocated, then return 0. This routine 3274 * is called by TCP routines that access the rmx structure and by 3275 * tcp_mss_update to get the peer/interface MTU. 3276 */ 3277 uint32_t 3278 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3279 { 3280 struct nhop_object *nh; 3281 struct ifnet *ifp; 3282 uint32_t maxmtu = 0; 3283 3284 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3285 3286 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3287 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3288 if (nh == NULL) 3289 return (0); 3290 3291 ifp = nh->nh_ifp; 3292 maxmtu = nh->nh_mtu; 3293 3294 /* Report additional interface capabilities. */ 3295 if (cap != NULL) { 3296 if (ifp->if_capenable & IFCAP_TSO4 && 3297 ifp->if_hwassist & CSUM_TSO) { 3298 cap->ifcap |= CSUM_TSO; 3299 cap->tsomax = ifp->if_hw_tsomax; 3300 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3301 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3302 } 3303 } 3304 } 3305 return (maxmtu); 3306 } 3307 #endif /* INET */ 3308 3309 #ifdef INET6 3310 uint32_t 3311 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3312 { 3313 struct nhop_object *nh; 3314 struct in6_addr dst6; 3315 uint32_t scopeid; 3316 struct ifnet *ifp; 3317 uint32_t maxmtu = 0; 3318 3319 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3320 3321 if (inc->inc_flags & INC_IPV6MINMTU) 3322 return (IPV6_MMTU); 3323 3324 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3325 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3326 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3327 if (nh == NULL) 3328 return (0); 3329 3330 ifp = nh->nh_ifp; 3331 maxmtu = nh->nh_mtu; 3332 3333 /* Report additional interface capabilities. */ 3334 if (cap != NULL) { 3335 if (ifp->if_capenable & IFCAP_TSO6 && 3336 ifp->if_hwassist & CSUM_TSO) { 3337 cap->ifcap |= CSUM_TSO; 3338 cap->tsomax = ifp->if_hw_tsomax; 3339 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3340 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3341 } 3342 } 3343 } 3344 3345 return (maxmtu); 3346 } 3347 3348 /* 3349 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3350 * 3351 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3352 * The right place to do that is ip6_setpktopt() that has just been 3353 * executed. By the way it just filled ip6po_minmtu for us. 3354 */ 3355 void 3356 tcp6_use_min_mtu(struct tcpcb *tp) 3357 { 3358 struct inpcb *inp = tptoinpcb(tp); 3359 3360 INP_WLOCK_ASSERT(inp); 3361 /* 3362 * In case of the IPV6_USE_MIN_MTU socket 3363 * option, the INC_IPV6MINMTU flag to announce 3364 * a corresponding MSS during the initial 3365 * handshake. If the TCP connection is not in 3366 * the front states, just reduce the MSS being 3367 * used. This avoids the sending of TCP 3368 * segments which will be fragmented at the 3369 * IPv6 layer. 3370 */ 3371 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3372 if ((tp->t_state >= TCPS_SYN_SENT) && 3373 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3374 struct ip6_pktopts *opt; 3375 3376 opt = inp->in6p_outputopts; 3377 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3378 tp->t_maxseg > TCP6_MSS) 3379 tp->t_maxseg = TCP6_MSS; 3380 } 3381 } 3382 #endif /* INET6 */ 3383 3384 /* 3385 * Calculate effective SMSS per RFC5681 definition for a given TCP 3386 * connection at its current state, taking into account SACK and etc. 3387 */ 3388 u_int 3389 tcp_maxseg(const struct tcpcb *tp) 3390 { 3391 u_int optlen; 3392 3393 if (tp->t_flags & TF_NOOPT) 3394 return (tp->t_maxseg); 3395 3396 /* 3397 * Here we have a simplified code from tcp_addoptions(), 3398 * without a proper loop, and having most of paddings hardcoded. 3399 * We might make mistakes with padding here in some edge cases, 3400 * but this is harmless, since result of tcp_maxseg() is used 3401 * only in cwnd and ssthresh estimations. 3402 */ 3403 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3404 if (tp->t_flags & TF_RCVD_TSTMP) 3405 optlen = TCPOLEN_TSTAMP_APPA; 3406 else 3407 optlen = 0; 3408 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3409 if (tp->t_flags & TF_SIGNATURE) 3410 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3411 #endif 3412 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3413 optlen += TCPOLEN_SACKHDR; 3414 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3415 optlen = PADTCPOLEN(optlen); 3416 } 3417 } else { 3418 if (tp->t_flags & TF_REQ_TSTMP) 3419 optlen = TCPOLEN_TSTAMP_APPA; 3420 else 3421 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3422 if (tp->t_flags & TF_REQ_SCALE) 3423 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3424 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3425 if (tp->t_flags & TF_SIGNATURE) 3426 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3427 #endif 3428 if (tp->t_flags & TF_SACK_PERMIT) 3429 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3430 } 3431 #undef PAD 3432 optlen = min(optlen, TCP_MAXOLEN); 3433 return (tp->t_maxseg - optlen); 3434 } 3435 3436 3437 u_int 3438 tcp_fixed_maxseg(const struct tcpcb *tp) 3439 { 3440 int optlen; 3441 3442 if (tp->t_flags & TF_NOOPT) 3443 return (tp->t_maxseg); 3444 3445 /* 3446 * Here we have a simplified code from tcp_addoptions(), 3447 * without a proper loop, and having most of paddings hardcoded. 3448 * We only consider fixed options that we would send every 3449 * time I.e. SACK is not considered. This is important 3450 * for cc modules to figure out what the modulo of the 3451 * cwnd should be. 3452 */ 3453 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3454 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3455 if (tp->t_flags & TF_RCVD_TSTMP) 3456 optlen = TCPOLEN_TSTAMP_APPA; 3457 else 3458 optlen = 0; 3459 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3460 if (tp->t_flags & TF_SIGNATURE) 3461 optlen += PAD(TCPOLEN_SIGNATURE); 3462 #endif 3463 } else { 3464 if (tp->t_flags & TF_REQ_TSTMP) 3465 optlen = TCPOLEN_TSTAMP_APPA; 3466 else 3467 optlen = PAD(TCPOLEN_MAXSEG); 3468 if (tp->t_flags & TF_REQ_SCALE) 3469 optlen += PAD(TCPOLEN_WINDOW); 3470 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3471 if (tp->t_flags & TF_SIGNATURE) 3472 optlen += PAD(TCPOLEN_SIGNATURE); 3473 #endif 3474 if (tp->t_flags & TF_SACK_PERMIT) 3475 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3476 } 3477 #undef PAD 3478 optlen = min(optlen, TCP_MAXOLEN); 3479 return (tp->t_maxseg - optlen); 3480 } 3481 3482 3483 3484 static int 3485 sysctl_drop(SYSCTL_HANDLER_ARGS) 3486 { 3487 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3488 struct sockaddr_storage addrs[2]; 3489 struct inpcb *inp; 3490 struct tcpcb *tp; 3491 #ifdef INET 3492 struct sockaddr_in *fin = NULL, *lin = NULL; 3493 #endif 3494 struct epoch_tracker et; 3495 #ifdef INET6 3496 struct sockaddr_in6 *fin6, *lin6; 3497 #endif 3498 int error; 3499 3500 inp = NULL; 3501 #ifdef INET6 3502 fin6 = lin6 = NULL; 3503 #endif 3504 error = 0; 3505 3506 if (req->oldptr != NULL || req->oldlen != 0) 3507 return (EINVAL); 3508 if (req->newptr == NULL) 3509 return (EPERM); 3510 if (req->newlen < sizeof(addrs)) 3511 return (ENOMEM); 3512 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3513 if (error) 3514 return (error); 3515 3516 switch (addrs[0].ss_family) { 3517 #ifdef INET6 3518 case AF_INET6: 3519 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3520 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3521 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3522 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3523 return (EINVAL); 3524 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3525 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3526 return (EINVAL); 3527 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3528 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3529 #ifdef INET 3530 fin = (struct sockaddr_in *)&addrs[0]; 3531 lin = (struct sockaddr_in *)&addrs[1]; 3532 #endif 3533 break; 3534 } 3535 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3536 if (error) 3537 return (error); 3538 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3539 if (error) 3540 return (error); 3541 break; 3542 #endif 3543 #ifdef INET 3544 case AF_INET: 3545 fin = (struct sockaddr_in *)&addrs[0]; 3546 lin = (struct sockaddr_in *)&addrs[1]; 3547 if (fin->sin_len != sizeof(struct sockaddr_in) || 3548 lin->sin_len != sizeof(struct sockaddr_in)) 3549 return (EINVAL); 3550 break; 3551 #endif 3552 default: 3553 return (EINVAL); 3554 } 3555 NET_EPOCH_ENTER(et); 3556 switch (addrs[0].ss_family) { 3557 #ifdef INET6 3558 case AF_INET6: 3559 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3560 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3561 INPLOOKUP_WLOCKPCB, NULL); 3562 break; 3563 #endif 3564 #ifdef INET 3565 case AF_INET: 3566 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3567 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3568 break; 3569 #endif 3570 } 3571 if (inp != NULL) { 3572 if (!SOLISTENING(inp->inp_socket)) { 3573 tp = intotcpcb(inp); 3574 tp = tcp_drop(tp, ECONNABORTED); 3575 if (tp != NULL) 3576 INP_WUNLOCK(inp); 3577 } else 3578 INP_WUNLOCK(inp); 3579 } else 3580 error = ESRCH; 3581 NET_EPOCH_EXIT(et); 3582 return (error); 3583 } 3584 3585 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3586 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3587 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3588 "Drop TCP connection"); 3589 3590 static int 3591 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3592 { 3593 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3594 &tcp_ctloutput_set)); 3595 } 3596 3597 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3598 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3599 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3600 "Set socket option for TCP endpoint"); 3601 3602 #ifdef KERN_TLS 3603 static int 3604 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3605 { 3606 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3607 struct sockaddr_storage addrs[2]; 3608 struct inpcb *inp; 3609 #ifdef INET 3610 struct sockaddr_in *fin = NULL, *lin = NULL; 3611 #endif 3612 struct epoch_tracker et; 3613 #ifdef INET6 3614 struct sockaddr_in6 *fin6, *lin6; 3615 #endif 3616 int error; 3617 3618 inp = NULL; 3619 #ifdef INET6 3620 fin6 = lin6 = NULL; 3621 #endif 3622 error = 0; 3623 3624 if (req->oldptr != NULL || req->oldlen != 0) 3625 return (EINVAL); 3626 if (req->newptr == NULL) 3627 return (EPERM); 3628 if (req->newlen < sizeof(addrs)) 3629 return (ENOMEM); 3630 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3631 if (error) 3632 return (error); 3633 3634 switch (addrs[0].ss_family) { 3635 #ifdef INET6 3636 case AF_INET6: 3637 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3638 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3639 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3640 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3641 return (EINVAL); 3642 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3643 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3644 return (EINVAL); 3645 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3646 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3647 #ifdef INET 3648 fin = (struct sockaddr_in *)&addrs[0]; 3649 lin = (struct sockaddr_in *)&addrs[1]; 3650 #endif 3651 break; 3652 } 3653 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3654 if (error) 3655 return (error); 3656 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3657 if (error) 3658 return (error); 3659 break; 3660 #endif 3661 #ifdef INET 3662 case AF_INET: 3663 fin = (struct sockaddr_in *)&addrs[0]; 3664 lin = (struct sockaddr_in *)&addrs[1]; 3665 if (fin->sin_len != sizeof(struct sockaddr_in) || 3666 lin->sin_len != sizeof(struct sockaddr_in)) 3667 return (EINVAL); 3668 break; 3669 #endif 3670 default: 3671 return (EINVAL); 3672 } 3673 NET_EPOCH_ENTER(et); 3674 switch (addrs[0].ss_family) { 3675 #ifdef INET6 3676 case AF_INET6: 3677 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3678 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3679 INPLOOKUP_WLOCKPCB, NULL); 3680 break; 3681 #endif 3682 #ifdef INET 3683 case AF_INET: 3684 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3685 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3686 break; 3687 #endif 3688 } 3689 NET_EPOCH_EXIT(et); 3690 if (inp != NULL) { 3691 struct socket *so; 3692 3693 so = inp->inp_socket; 3694 soref(so); 3695 error = ktls_set_tx_mode(so, 3696 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3697 INP_WUNLOCK(inp); 3698 sorele(so); 3699 } else 3700 error = ESRCH; 3701 return (error); 3702 } 3703 3704 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3705 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3706 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3707 "Switch TCP connection to SW TLS"); 3708 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3709 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3710 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3711 "Switch TCP connection to ifnet TLS"); 3712 #endif 3713 3714 /* 3715 * Generate a standardized TCP log line for use throughout the 3716 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3717 * allow use in the interrupt context. 3718 * 3719 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3720 * NB: The function may return NULL if memory allocation failed. 3721 * 3722 * Due to header inclusion and ordering limitations the struct ip 3723 * and ip6_hdr pointers have to be passed as void pointers. 3724 */ 3725 char * 3726 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3727 const void *ip6hdr) 3728 { 3729 3730 /* Is logging enabled? */ 3731 if (V_tcp_log_in_vain == 0) 3732 return (NULL); 3733 3734 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3735 } 3736 3737 char * 3738 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3739 const void *ip6hdr) 3740 { 3741 3742 /* Is logging enabled? */ 3743 if (tcp_log_debug == 0) 3744 return (NULL); 3745 3746 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3747 } 3748 3749 static char * 3750 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3751 const void *ip6hdr) 3752 { 3753 char *s, *sp; 3754 size_t size; 3755 #ifdef INET 3756 const struct ip *ip = (const struct ip *)ip4hdr; 3757 #endif 3758 #ifdef INET6 3759 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3760 #endif /* INET6 */ 3761 3762 /* 3763 * The log line looks like this: 3764 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3765 */ 3766 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3767 sizeof(PRINT_TH_FLAGS) + 1 + 3768 #ifdef INET6 3769 2 * INET6_ADDRSTRLEN; 3770 #else 3771 2 * INET_ADDRSTRLEN; 3772 #endif /* INET6 */ 3773 3774 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3775 if (s == NULL) 3776 return (NULL); 3777 3778 strcat(s, "TCP: ["); 3779 sp = s + strlen(s); 3780 3781 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3782 inet_ntoa_r(inc->inc_faddr, sp); 3783 sp = s + strlen(s); 3784 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3785 sp = s + strlen(s); 3786 inet_ntoa_r(inc->inc_laddr, sp); 3787 sp = s + strlen(s); 3788 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3789 #ifdef INET6 3790 } else if (inc) { 3791 ip6_sprintf(sp, &inc->inc6_faddr); 3792 sp = s + strlen(s); 3793 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3794 sp = s + strlen(s); 3795 ip6_sprintf(sp, &inc->inc6_laddr); 3796 sp = s + strlen(s); 3797 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3798 } else if (ip6 && th) { 3799 ip6_sprintf(sp, &ip6->ip6_src); 3800 sp = s + strlen(s); 3801 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3802 sp = s + strlen(s); 3803 ip6_sprintf(sp, &ip6->ip6_dst); 3804 sp = s + strlen(s); 3805 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3806 #endif /* INET6 */ 3807 #ifdef INET 3808 } else if (ip && th) { 3809 inet_ntoa_r(ip->ip_src, sp); 3810 sp = s + strlen(s); 3811 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3812 sp = s + strlen(s); 3813 inet_ntoa_r(ip->ip_dst, sp); 3814 sp = s + strlen(s); 3815 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3816 #endif /* INET */ 3817 } else { 3818 free(s, M_TCPLOG); 3819 return (NULL); 3820 } 3821 sp = s + strlen(s); 3822 if (th) 3823 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3824 if (*(s + size - 1) != '\0') 3825 panic("%s: string too long", __func__); 3826 return (s); 3827 } 3828 3829 /* 3830 * A subroutine which makes it easy to track TCP state changes with DTrace. 3831 * This function shouldn't be called for t_state initializations that don't 3832 * correspond to actual TCP state transitions. 3833 */ 3834 void 3835 tcp_state_change(struct tcpcb *tp, int newstate) 3836 { 3837 #if defined(KDTRACE_HOOKS) 3838 int pstate = tp->t_state; 3839 #endif 3840 3841 TCPSTATES_DEC(tp->t_state); 3842 TCPSTATES_INC(newstate); 3843 tp->t_state = newstate; 3844 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3845 } 3846 3847 /* 3848 * Create an external-format (``xtcpcb'') structure using the information in 3849 * the kernel-format tcpcb structure pointed to by tp. This is done to 3850 * reduce the spew of irrelevant information over this interface, to isolate 3851 * user code from changes in the kernel structure, and potentially to provide 3852 * information-hiding if we decide that some of this information should be 3853 * hidden from users. 3854 */ 3855 void 3856 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3857 { 3858 struct tcpcb *tp = intotcpcb(inp); 3859 sbintime_t now; 3860 3861 bzero(xt, sizeof(*xt)); 3862 xt->t_state = tp->t_state; 3863 xt->t_logstate = tp->t_logstate; 3864 xt->t_flags = tp->t_flags; 3865 xt->t_sndzerowin = tp->t_sndzerowin; 3866 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3867 xt->t_rcvoopack = tp->t_rcvoopack; 3868 xt->t_rcv_wnd = tp->rcv_wnd; 3869 xt->t_snd_wnd = tp->snd_wnd; 3870 xt->t_snd_cwnd = tp->snd_cwnd; 3871 xt->t_snd_ssthresh = tp->snd_ssthresh; 3872 xt->t_dsack_bytes = tp->t_dsack_bytes; 3873 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 3874 xt->t_dsack_pack = tp->t_dsack_pack; 3875 xt->t_maxseg = tp->t_maxseg; 3876 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3877 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3878 3879 now = getsbinuptime(); 3880 #define COPYTIMER(which,where) do { \ 3881 if (tp->t_timers[which] != SBT_MAX) \ 3882 xt->where = (tp->t_timers[which] - now) / SBT_1MS; \ 3883 else \ 3884 xt->where = 0; \ 3885 } while (0) 3886 COPYTIMER(TT_DELACK, tt_delack); 3887 COPYTIMER(TT_REXMT, tt_rexmt); 3888 COPYTIMER(TT_PERSIST, tt_persist); 3889 COPYTIMER(TT_KEEP, tt_keep); 3890 COPYTIMER(TT_2MSL, tt_2msl); 3891 #undef COPYTIMER 3892 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3893 3894 xt->xt_encaps_port = tp->t_port; 3895 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3896 TCP_FUNCTION_NAME_LEN_MAX); 3897 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX); 3898 #ifdef TCP_BLACKBOX 3899 (void)tcp_log_get_id(tp, xt->xt_logid); 3900 #endif 3901 3902 xt->xt_len = sizeof(struct xtcpcb); 3903 in_pcbtoxinpcb(inp, &xt->xt_inp); 3904 } 3905 3906 void 3907 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 3908 { 3909 uint32_t bit, i; 3910 3911 if ((tp == NULL) || 3912 (status > TCP_EI_STATUS_MAX_VALUE) || 3913 (status == 0)) { 3914 /* Invalid */ 3915 return; 3916 } 3917 if (status > (sizeof(uint32_t) * 8)) { 3918 /* Should this be a KASSERT? */ 3919 return; 3920 } 3921 bit = 1U << (status - 1); 3922 if (bit & tp->t_end_info_status) { 3923 /* already logged */ 3924 return; 3925 } 3926 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 3927 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 3928 tp->t_end_info_bytes[i] = status; 3929 tp->t_end_info_status |= bit; 3930 break; 3931 } 3932 } 3933 } 3934 3935 int 3936 tcp_can_enable_pacing(void) 3937 { 3938 3939 if ((tcp_pacing_limit == -1) || 3940 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 3941 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 3942 shadow_num_connections = number_of_tcp_connections_pacing; 3943 return (1); 3944 } else { 3945 return (0); 3946 } 3947 } 3948 3949 static uint8_t tcp_pacing_warning = 0; 3950 3951 void 3952 tcp_decrement_paced_conn(void) 3953 { 3954 uint32_t ret; 3955 3956 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 3957 shadow_num_connections = number_of_tcp_connections_pacing; 3958 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 3959 if (ret == 0) { 3960 if (tcp_pacing_limit != -1) { 3961 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 3962 tcp_pacing_limit = 0; 3963 } else if (tcp_pacing_warning == 0) { 3964 printf("Warning pacing count is invalid, invalid decrement\n"); 3965 tcp_pacing_warning = 1; 3966 } 3967 } 3968 }
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