1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #ifdef INET6 66 #include <sys/domain.h> 67 #endif 68 #include <sys/priv.h> 69 #include <sys/proc.h> 70 #include <sys/sdt.h> 71 #include <sys/socket.h> 72 #include <sys/socketvar.h> 73 #include <sys/protosw.h> 74 #include <sys/random.h> 75 76 #include <vm/uma.h> 77 78 #include <net/route.h> 79 #include <net/route/nhop.h> 80 #include <net/if.h> 81 #include <net/if_var.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_fib.h> 86 #include <netinet/in_kdtrace.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/ip_icmp.h> 92 #include <netinet/ip_var.h> 93 #ifdef INET6 94 #include <netinet/icmp6.h> 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_fib.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet6/scope6_var.h> 100 #include <netinet6/nd6.h> 101 #endif 102 103 #include <netinet/tcp.h> 104 #ifdef INVARIANTS 105 #define TCPSTATES 106 #endif 107 #include <netinet/tcp_fsm.h> 108 #include <netinet/tcp_seq.h> 109 #include <netinet/tcp_timer.h> 110 #include <netinet/tcp_var.h> 111 #include <netinet/tcp_log_buf.h> 112 #include <netinet/tcp_syncache.h> 113 #include <netinet/tcp_hpts.h> 114 #include <netinet/cc/cc.h> 115 #ifdef INET6 116 #include <netinet6/tcp6_var.h> 117 #endif 118 #include <netinet/tcpip.h> 119 #include <netinet/tcp_fastopen.h> 120 #ifdef TCPPCAP 121 #include <netinet/tcp_pcap.h> 122 #endif 123 #ifdef TCPDEBUG 124 #include <netinet/tcp_debug.h> 125 #endif 126 #ifdef INET6 127 #include <netinet6/ip6protosw.h> 128 #endif 129 #ifdef TCP_OFFLOAD 130 #include <netinet/tcp_offload.h> 131 #endif 132 #include <netinet/udp.h> 133 #include <netinet/udp_var.h> 134 135 #include <netipsec/ipsec_support.h> 136 137 #include <machine/in_cksum.h> 138 #include <crypto/siphash/siphash.h> 139 140 #include <security/mac/mac_framework.h> 141 142 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 143 #ifdef INET6 144 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 145 #endif 146 147 #ifdef NETFLIX_EXP_DETECTION 148 /* Sack attack detection thresholds and such */ 149 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 150 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 151 "Sack Attack detection thresholds"); 152 int32_t tcp_force_detection = 0; 153 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 154 CTLFLAG_RW, 155 &tcp_force_detection, 0, 156 "Do we force detection even if the INP has it off?"); 157 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 158 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 159 CTLFLAG_RW, 160 &tcp_sack_to_ack_thresh, 700, 161 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 162 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 163 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 164 CTLFLAG_RW, 165 &tcp_sack_to_move_thresh, 600, 166 "Percentage of sack moves we must see above (10.1 percent is 101)"); 167 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 168 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 169 CTLFLAG_RW, 170 &tcp_restoral_thresh, 550, 171 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 172 int32_t tcp_sad_decay_val = 800; 173 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 174 CTLFLAG_RW, 175 &tcp_sad_decay_val, 800, 176 "The decay percentage (10.1 percent equals 101 )"); 177 int32_t tcp_map_minimum = 500; 178 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 179 CTLFLAG_RW, 180 &tcp_map_minimum, 500, 181 "Number of Map enteries before we start detection"); 182 int32_t tcp_attack_on_turns_on_logging = 0; 183 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 184 CTLFLAG_RW, 185 &tcp_attack_on_turns_on_logging, 0, 186 "When we have a positive hit on attack, do we turn on logging?"); 187 int32_t tcp_sad_pacing_interval = 2000; 188 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 189 CTLFLAG_RW, 190 &tcp_sad_pacing_interval, 2000, 191 "What is the minimum pacing interval for a classified attacker?"); 192 193 int32_t tcp_sad_low_pps = 100; 194 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 195 CTLFLAG_RW, 196 &tcp_sad_low_pps, 100, 197 "What is the input pps that below which we do not decay?"); 198 #endif 199 uint32_t tcp_ack_war_time_window = 1000; 200 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 201 CTLFLAG_RW, 202 &tcp_ack_war_time_window, 1000, 203 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 204 uint32_t tcp_ack_war_cnt = 5; 205 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 206 CTLFLAG_RW, 207 &tcp_ack_war_cnt, 5, 208 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 209 210 struct rwlock tcp_function_lock; 211 212 static int 213 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 214 { 215 int error, new; 216 217 new = V_tcp_mssdflt; 218 error = sysctl_handle_int(oidp, &new, 0, req); 219 if (error == 0 && req->newptr) { 220 if (new < TCP_MINMSS) 221 error = EINVAL; 222 else 223 V_tcp_mssdflt = new; 224 } 225 return (error); 226 } 227 228 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 229 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 230 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 231 "Default TCP Maximum Segment Size"); 232 233 #ifdef INET6 234 static int 235 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 236 { 237 int error, new; 238 239 new = V_tcp_v6mssdflt; 240 error = sysctl_handle_int(oidp, &new, 0, req); 241 if (error == 0 && req->newptr) { 242 if (new < TCP_MINMSS) 243 error = EINVAL; 244 else 245 V_tcp_v6mssdflt = new; 246 } 247 return (error); 248 } 249 250 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 251 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 252 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 253 "Default TCP Maximum Segment Size for IPv6"); 254 #endif /* INET6 */ 255 256 /* 257 * Minimum MSS we accept and use. This prevents DoS attacks where 258 * we are forced to a ridiculous low MSS like 20 and send hundreds 259 * of packets instead of one. The effect scales with the available 260 * bandwidth and quickly saturates the CPU and network interface 261 * with packet generation and sending. Set to zero to disable MINMSS 262 * checking. This setting prevents us from sending too small packets. 263 */ 264 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 265 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 266 &VNET_NAME(tcp_minmss), 0, 267 "Minimum TCP Maximum Segment Size"); 268 269 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 270 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 271 &VNET_NAME(tcp_do_rfc1323), 0, 272 "Enable rfc1323 (high performance TCP) extensions"); 273 274 /* 275 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 276 * Some stacks negotiate TS, but never send them after connection setup. Some 277 * stacks negotiate TS, but don't send them when sending keep-alive segments. 278 * These include modern widely deployed TCP stacks. 279 * Therefore tolerating violations for now... 280 */ 281 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 282 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 283 &VNET_NAME(tcp_tolerate_missing_ts), 0, 284 "Tolerate missing TCP timestamps"); 285 286 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 287 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 288 &VNET_NAME(tcp_ts_offset_per_conn), 0, 289 "Initialize TCP timestamps per connection instead of per host pair"); 290 291 /* How many connections are pacing */ 292 static volatile uint32_t number_of_tcp_connections_pacing = 0; 293 static uint32_t shadow_num_connections = 0; 294 295 static int tcp_pacing_limit = 10000; 296 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 297 &tcp_pacing_limit, 1000, 298 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 299 300 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 301 &shadow_num_connections, 0, "Number of TCP connections being paced"); 302 303 static int tcp_log_debug = 0; 304 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 305 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 306 307 static int tcp_tcbhashsize; 308 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 309 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 310 311 static int do_tcpdrain = 1; 312 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 313 "Enable tcp_drain routine for extra help when low on mbufs"); 314 315 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 316 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 317 318 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 319 #define V_icmp_may_rst VNET(icmp_may_rst) 320 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 321 &VNET_NAME(icmp_may_rst), 0, 322 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 323 324 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 325 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 326 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 327 &VNET_NAME(tcp_isn_reseed_interval), 0, 328 "Seconds between reseeding of ISN secret"); 329 330 static int tcp_soreceive_stream; 331 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 332 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 333 334 VNET_DEFINE(uma_zone_t, sack_hole_zone); 335 #define V_sack_hole_zone VNET(sack_hole_zone) 336 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 337 static int 338 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 339 { 340 int error; 341 uint32_t new; 342 343 new = V_tcp_map_entries_limit; 344 error = sysctl_handle_int(oidp, &new, 0, req); 345 if (error == 0 && req->newptr) { 346 /* only allow "0" and value > minimum */ 347 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 348 error = EINVAL; 349 else 350 V_tcp_map_entries_limit = new; 351 } 352 return (error); 353 } 354 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 355 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 356 &VNET_NAME(tcp_map_entries_limit), 0, 357 &sysctl_net_inet_tcp_map_limit_check, "IU", 358 "Total sendmap entries limit"); 359 360 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 361 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 362 &VNET_NAME(tcp_map_split_limit), 0, 363 "Total sendmap split entries limit"); 364 365 #ifdef TCP_HHOOK 366 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 367 #endif 368 369 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 370 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 371 #define V_ts_offset_secret VNET(ts_offset_secret) 372 373 static int tcp_default_fb_init(struct tcpcb *tp); 374 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 375 static int tcp_default_handoff_ok(struct tcpcb *tp); 376 static struct inpcb *tcp_notify(struct inpcb *, int); 377 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 378 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 379 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 380 void *ip4hdr, const void *ip6hdr); 381 382 static struct tcp_function_block tcp_def_funcblk = { 383 .tfb_tcp_block_name = "freebsd", 384 .tfb_tcp_output = tcp_default_output, 385 .tfb_tcp_do_segment = tcp_do_segment, 386 .tfb_tcp_ctloutput = tcp_default_ctloutput, 387 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 388 .tfb_tcp_fb_init = tcp_default_fb_init, 389 .tfb_tcp_fb_fini = tcp_default_fb_fini, 390 }; 391 392 static int tcp_fb_cnt = 0; 393 struct tcp_funchead t_functions; 394 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 395 396 void 397 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 398 { 399 TCPSTAT_INC(tcps_dsack_count); 400 tp->t_dsack_pack++; 401 if (tlp == 0) { 402 if (SEQ_GT(end, start)) { 403 tp->t_dsack_bytes += (end - start); 404 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 405 } else { 406 tp->t_dsack_tlp_bytes += (start - end); 407 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 408 } 409 } else { 410 if (SEQ_GT(end, start)) { 411 tp->t_dsack_bytes += (end - start); 412 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 413 } else { 414 tp->t_dsack_tlp_bytes += (start - end); 415 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 416 } 417 } 418 } 419 420 static struct tcp_function_block * 421 find_tcp_functions_locked(struct tcp_function_set *fs) 422 { 423 struct tcp_function *f; 424 struct tcp_function_block *blk=NULL; 425 426 TAILQ_FOREACH(f, &t_functions, tf_next) { 427 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 428 blk = f->tf_fb; 429 break; 430 } 431 } 432 return(blk); 433 } 434 435 static struct tcp_function_block * 436 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 437 { 438 struct tcp_function_block *rblk=NULL; 439 struct tcp_function *f; 440 441 TAILQ_FOREACH(f, &t_functions, tf_next) { 442 if (f->tf_fb == blk) { 443 rblk = blk; 444 if (s) { 445 *s = f; 446 } 447 break; 448 } 449 } 450 return (rblk); 451 } 452 453 struct tcp_function_block * 454 find_and_ref_tcp_functions(struct tcp_function_set *fs) 455 { 456 struct tcp_function_block *blk; 457 458 rw_rlock(&tcp_function_lock); 459 blk = find_tcp_functions_locked(fs); 460 if (blk) 461 refcount_acquire(&blk->tfb_refcnt); 462 rw_runlock(&tcp_function_lock); 463 return(blk); 464 } 465 466 struct tcp_function_block * 467 find_and_ref_tcp_fb(struct tcp_function_block *blk) 468 { 469 struct tcp_function_block *rblk; 470 471 rw_rlock(&tcp_function_lock); 472 rblk = find_tcp_fb_locked(blk, NULL); 473 if (rblk) 474 refcount_acquire(&rblk->tfb_refcnt); 475 rw_runlock(&tcp_function_lock); 476 return(rblk); 477 } 478 479 /* Find a matching alias for the given tcp_function_block. */ 480 int 481 find_tcp_function_alias(struct tcp_function_block *blk, 482 struct tcp_function_set *fs) 483 { 484 struct tcp_function *f; 485 int found; 486 487 found = 0; 488 rw_rlock(&tcp_function_lock); 489 TAILQ_FOREACH(f, &t_functions, tf_next) { 490 if ((f->tf_fb == blk) && 491 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 492 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 493 /* Matching function block with different name. */ 494 strncpy(fs->function_set_name, f->tf_name, 495 TCP_FUNCTION_NAME_LEN_MAX); 496 found = 1; 497 break; 498 } 499 } 500 /* Null terminate the string appropriately. */ 501 if (found) { 502 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 503 } else { 504 fs->function_set_name[0] = '\0'; 505 } 506 rw_runlock(&tcp_function_lock); 507 return (found); 508 } 509 510 static struct tcp_function_block * 511 find_and_ref_tcp_default_fb(void) 512 { 513 struct tcp_function_block *rblk; 514 515 rw_rlock(&tcp_function_lock); 516 rblk = tcp_func_set_ptr; 517 refcount_acquire(&rblk->tfb_refcnt); 518 rw_runlock(&tcp_function_lock); 519 return (rblk); 520 } 521 522 void 523 tcp_switch_back_to_default(struct tcpcb *tp) 524 { 525 struct tcp_function_block *tfb; 526 527 KASSERT(tp->t_fb != &tcp_def_funcblk, 528 ("%s: called by the built-in default stack", __func__)); 529 530 /* 531 * Release the old stack. This function will either find a new one 532 * or panic. 533 */ 534 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 535 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 536 refcount_release(&tp->t_fb->tfb_refcnt); 537 538 /* 539 * Now, we'll find a new function block to use. 540 * Start by trying the current user-selected 541 * default, unless this stack is the user-selected 542 * default. 543 */ 544 tfb = find_and_ref_tcp_default_fb(); 545 if (tfb == tp->t_fb) { 546 refcount_release(&tfb->tfb_refcnt); 547 tfb = NULL; 548 } 549 /* Does the stack accept this connection? */ 550 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 551 (*tfb->tfb_tcp_handoff_ok)(tp)) { 552 refcount_release(&tfb->tfb_refcnt); 553 tfb = NULL; 554 } 555 /* Try to use that stack. */ 556 if (tfb != NULL) { 557 /* Initialize the new stack. If it succeeds, we are done. */ 558 tp->t_fb = tfb; 559 if (tp->t_fb->tfb_tcp_fb_init == NULL || 560 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 561 return; 562 563 /* 564 * Initialization failed. Release the reference count on 565 * the stack. 566 */ 567 refcount_release(&tfb->tfb_refcnt); 568 } 569 570 /* 571 * If that wasn't feasible, use the built-in default 572 * stack which is not allowed to reject anyone. 573 */ 574 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 575 if (tfb == NULL) { 576 /* there always should be a default */ 577 panic("Can't refer to tcp_def_funcblk"); 578 } 579 if (tfb->tfb_tcp_handoff_ok != NULL) { 580 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 581 /* The default stack cannot say no */ 582 panic("Default stack rejects a new session?"); 583 } 584 } 585 tp->t_fb = tfb; 586 if (tp->t_fb->tfb_tcp_fb_init != NULL && 587 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 588 /* The default stack cannot fail */ 589 panic("Default stack initialization failed"); 590 } 591 } 592 593 static void 594 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 595 const struct sockaddr *sa, void *ctx) 596 { 597 struct ip *iph; 598 #ifdef INET6 599 struct ip6_hdr *ip6; 600 #endif 601 struct udphdr *uh; 602 struct tcphdr *th; 603 int thlen; 604 uint16_t port; 605 606 TCPSTAT_INC(tcps_tunneled_pkts); 607 if ((m->m_flags & M_PKTHDR) == 0) { 608 /* Can't handle one that is not a pkt hdr */ 609 TCPSTAT_INC(tcps_tunneled_errs); 610 goto out; 611 } 612 thlen = sizeof(struct tcphdr); 613 if (m->m_len < off + sizeof(struct udphdr) + thlen && 614 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 615 TCPSTAT_INC(tcps_tunneled_errs); 616 goto out; 617 } 618 iph = mtod(m, struct ip *); 619 uh = (struct udphdr *)((caddr_t)iph + off); 620 th = (struct tcphdr *)(uh + 1); 621 thlen = th->th_off << 2; 622 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 623 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 624 if (m == NULL) { 625 TCPSTAT_INC(tcps_tunneled_errs); 626 goto out; 627 } else { 628 iph = mtod(m, struct ip *); 629 uh = (struct udphdr *)((caddr_t)iph + off); 630 th = (struct tcphdr *)(uh + 1); 631 } 632 } 633 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 634 bcopy(th, uh, m->m_len - off); 635 m->m_len -= sizeof(struct udphdr); 636 m->m_pkthdr.len -= sizeof(struct udphdr); 637 /* 638 * We use the same algorithm for 639 * both UDP and TCP for c-sum. So 640 * the code in tcp_input will skip 641 * the checksum. So we do nothing 642 * with the flag (m->m_pkthdr.csum_flags). 643 */ 644 switch (iph->ip_v) { 645 #ifdef INET 646 case IPVERSION: 647 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 648 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 649 break; 650 #endif 651 #ifdef INET6 652 case IPV6_VERSION >> 4: 653 ip6 = mtod(m, struct ip6_hdr *); 654 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 655 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 656 break; 657 #endif 658 default: 659 goto out; 660 break; 661 } 662 return; 663 out: 664 m_freem(m); 665 } 666 667 static int 668 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 669 { 670 int error=ENOENT; 671 struct tcp_function_set fs; 672 struct tcp_function_block *blk; 673 674 memset(&fs, 0, sizeof(fs)); 675 rw_rlock(&tcp_function_lock); 676 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 677 if (blk) { 678 /* Found him */ 679 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 680 fs.pcbcnt = blk->tfb_refcnt; 681 } 682 rw_runlock(&tcp_function_lock); 683 error = sysctl_handle_string(oidp, fs.function_set_name, 684 sizeof(fs.function_set_name), req); 685 686 /* Check for error or no change */ 687 if (error != 0 || req->newptr == NULL) 688 return(error); 689 690 rw_wlock(&tcp_function_lock); 691 blk = find_tcp_functions_locked(&fs); 692 if ((blk == NULL) || 693 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 694 error = ENOENT; 695 goto done; 696 } 697 tcp_func_set_ptr = blk; 698 done: 699 rw_wunlock(&tcp_function_lock); 700 return (error); 701 } 702 703 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 704 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 705 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 706 "Set/get the default TCP functions"); 707 708 static int 709 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 710 { 711 int error, cnt, linesz; 712 struct tcp_function *f; 713 char *buffer, *cp; 714 size_t bufsz, outsz; 715 bool alias; 716 717 cnt = 0; 718 rw_rlock(&tcp_function_lock); 719 TAILQ_FOREACH(f, &t_functions, tf_next) { 720 cnt++; 721 } 722 rw_runlock(&tcp_function_lock); 723 724 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 725 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 726 727 error = 0; 728 cp = buffer; 729 730 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 731 "Alias", "PCB count"); 732 cp += linesz; 733 bufsz -= linesz; 734 outsz = linesz; 735 736 rw_rlock(&tcp_function_lock); 737 TAILQ_FOREACH(f, &t_functions, tf_next) { 738 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 739 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 740 f->tf_fb->tfb_tcp_block_name, 741 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 742 alias ? f->tf_name : "-", 743 f->tf_fb->tfb_refcnt); 744 if (linesz >= bufsz) { 745 error = EOVERFLOW; 746 break; 747 } 748 cp += linesz; 749 bufsz -= linesz; 750 outsz += linesz; 751 } 752 rw_runlock(&tcp_function_lock); 753 if (error == 0) 754 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 755 free(buffer, M_TEMP); 756 return (error); 757 } 758 759 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 760 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 761 NULL, 0, sysctl_net_inet_list_available, "A", 762 "list available TCP Function sets"); 763 764 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 765 766 #ifdef INET 767 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 768 #define V_udp4_tun_socket VNET(udp4_tun_socket) 769 #endif 770 #ifdef INET6 771 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 772 #define V_udp6_tun_socket VNET(udp6_tun_socket) 773 #endif 774 775 static void 776 tcp_over_udp_stop(void) 777 { 778 /* 779 * This function assumes sysctl caller holds inp_rinfo_lock() 780 * for writing! 781 */ 782 #ifdef INET 783 if (V_udp4_tun_socket != NULL) { 784 soclose(V_udp4_tun_socket); 785 V_udp4_tun_socket = NULL; 786 } 787 #endif 788 #ifdef INET6 789 if (V_udp6_tun_socket != NULL) { 790 soclose(V_udp6_tun_socket); 791 V_udp6_tun_socket = NULL; 792 } 793 #endif 794 } 795 796 static int 797 tcp_over_udp_start(void) 798 { 799 uint16_t port; 800 int ret; 801 #ifdef INET 802 struct sockaddr_in sin; 803 #endif 804 #ifdef INET6 805 struct sockaddr_in6 sin6; 806 #endif 807 /* 808 * This function assumes sysctl caller holds inp_info_rlock() 809 * for writing! 810 */ 811 port = V_tcp_udp_tunneling_port; 812 if (ntohs(port) == 0) { 813 /* Must have a port set */ 814 return (EINVAL); 815 } 816 #ifdef INET 817 if (V_udp4_tun_socket != NULL) { 818 /* Already running -- must stop first */ 819 return (EALREADY); 820 } 821 #endif 822 #ifdef INET6 823 if (V_udp6_tun_socket != NULL) { 824 /* Already running -- must stop first */ 825 return (EALREADY); 826 } 827 #endif 828 #ifdef INET 829 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 830 SOCK_DGRAM, IPPROTO_UDP, 831 curthread->td_ucred, curthread))) { 832 tcp_over_udp_stop(); 833 return (ret); 834 } 835 /* Call the special UDP hook. */ 836 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 837 tcp_recv_udp_tunneled_packet, 838 tcp_ctlinput_viaudp, 839 NULL))) { 840 tcp_over_udp_stop(); 841 return (ret); 842 } 843 /* Ok, we have a socket, bind it to the port. */ 844 memset(&sin, 0, sizeof(struct sockaddr_in)); 845 sin.sin_len = sizeof(struct sockaddr_in); 846 sin.sin_family = AF_INET; 847 sin.sin_port = htons(port); 848 if ((ret = sobind(V_udp4_tun_socket, 849 (struct sockaddr *)&sin, curthread))) { 850 tcp_over_udp_stop(); 851 return (ret); 852 } 853 #endif 854 #ifdef INET6 855 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 856 SOCK_DGRAM, IPPROTO_UDP, 857 curthread->td_ucred, curthread))) { 858 tcp_over_udp_stop(); 859 return (ret); 860 } 861 /* Call the special UDP hook. */ 862 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 863 tcp_recv_udp_tunneled_packet, 864 tcp6_ctlinput_viaudp, 865 NULL))) { 866 tcp_over_udp_stop(); 867 return (ret); 868 } 869 /* Ok, we have a socket, bind it to the port. */ 870 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 871 sin6.sin6_len = sizeof(struct sockaddr_in6); 872 sin6.sin6_family = AF_INET6; 873 sin6.sin6_port = htons(port); 874 if ((ret = sobind(V_udp6_tun_socket, 875 (struct sockaddr *)&sin6, curthread))) { 876 tcp_over_udp_stop(); 877 return (ret); 878 } 879 #endif 880 return (0); 881 } 882 883 static int 884 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 885 { 886 int error; 887 uint32_t old, new; 888 889 old = V_tcp_udp_tunneling_port; 890 new = old; 891 error = sysctl_handle_int(oidp, &new, 0, req); 892 if ((error == 0) && 893 (req->newptr != NULL)) { 894 if ((new < TCP_TUNNELING_PORT_MIN) || 895 (new > TCP_TUNNELING_PORT_MAX)) { 896 error = EINVAL; 897 } else { 898 V_tcp_udp_tunneling_port = new; 899 if (old != 0) { 900 tcp_over_udp_stop(); 901 } 902 if (new != 0) { 903 error = tcp_over_udp_start(); 904 } 905 } 906 } 907 return (error); 908 } 909 910 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 911 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 912 &VNET_NAME(tcp_udp_tunneling_port), 913 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 914 "Tunneling port for tcp over udp"); 915 916 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 917 918 static int 919 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 920 { 921 int error, new; 922 923 new = V_tcp_udp_tunneling_overhead; 924 error = sysctl_handle_int(oidp, &new, 0, req); 925 if (error == 0 && req->newptr) { 926 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 927 (new > TCP_TUNNELING_OVERHEAD_MAX)) 928 error = EINVAL; 929 else 930 V_tcp_udp_tunneling_overhead = new; 931 } 932 return (error); 933 } 934 935 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 936 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 937 &VNET_NAME(tcp_udp_tunneling_overhead), 938 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 939 "MSS reduction when using tcp over udp"); 940 941 /* 942 * Exports one (struct tcp_function_info) for each alias/name. 943 */ 944 static int 945 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 946 { 947 int cnt, error; 948 struct tcp_function *f; 949 struct tcp_function_info tfi; 950 951 /* 952 * We don't allow writes. 953 */ 954 if (req->newptr != NULL) 955 return (EINVAL); 956 957 /* 958 * Wire the old buffer so we can directly copy the functions to 959 * user space without dropping the lock. 960 */ 961 if (req->oldptr != NULL) { 962 error = sysctl_wire_old_buffer(req, 0); 963 if (error) 964 return (error); 965 } 966 967 /* 968 * Walk the list and copy out matching entries. If INVARIANTS 969 * is compiled in, also walk the list to verify the length of 970 * the list matches what we have recorded. 971 */ 972 rw_rlock(&tcp_function_lock); 973 974 cnt = 0; 975 #ifndef INVARIANTS 976 if (req->oldptr == NULL) { 977 cnt = tcp_fb_cnt; 978 goto skip_loop; 979 } 980 #endif 981 TAILQ_FOREACH(f, &t_functions, tf_next) { 982 #ifdef INVARIANTS 983 cnt++; 984 #endif 985 if (req->oldptr != NULL) { 986 bzero(&tfi, sizeof(tfi)); 987 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 988 tfi.tfi_id = f->tf_fb->tfb_id; 989 (void)strlcpy(tfi.tfi_alias, f->tf_name, 990 sizeof(tfi.tfi_alias)); 991 (void)strlcpy(tfi.tfi_name, 992 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 993 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 994 /* 995 * Don't stop on error, as that is the 996 * mechanism we use to accumulate length 997 * information if the buffer was too short. 998 */ 999 } 1000 } 1001 KASSERT(cnt == tcp_fb_cnt, 1002 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1003 #ifndef INVARIANTS 1004 skip_loop: 1005 #endif 1006 rw_runlock(&tcp_function_lock); 1007 if (req->oldptr == NULL) 1008 error = SYSCTL_OUT(req, NULL, 1009 (cnt + 1) * sizeof(struct tcp_function_info)); 1010 1011 return (error); 1012 } 1013 1014 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1015 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1016 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1017 "List TCP function block name-to-ID mappings"); 1018 1019 /* 1020 * tfb_tcp_handoff_ok() function for the default stack. 1021 * Note that we'll basically try to take all comers. 1022 */ 1023 static int 1024 tcp_default_handoff_ok(struct tcpcb *tp) 1025 { 1026 1027 return (0); 1028 } 1029 1030 /* 1031 * tfb_tcp_fb_init() function for the default stack. 1032 * 1033 * This handles making sure we have appropriate timers set if you are 1034 * transitioning a socket that has some amount of setup done. 1035 * 1036 * The init() fuction from the default can *never* return non-zero i.e. 1037 * it is required to always succeed since it is the stack of last resort! 1038 */ 1039 static int 1040 tcp_default_fb_init(struct tcpcb *tp) 1041 { 1042 1043 struct socket *so; 1044 1045 INP_WLOCK_ASSERT(tp->t_inpcb); 1046 1047 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1048 ("%s: connection %p in unexpected state %d", __func__, tp, 1049 tp->t_state)); 1050 1051 /* 1052 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1053 * know what to do for unexpected states (which includes TIME_WAIT). 1054 */ 1055 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1056 return (0); 1057 1058 /* 1059 * Make sure some kind of transmission timer is set if there is 1060 * outstanding data. 1061 */ 1062 so = tp->t_inpcb->inp_socket; 1063 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1064 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1065 tcp_timer_active(tp, TT_PERSIST))) { 1066 /* 1067 * If the session has established and it looks like it should 1068 * be in the persist state, set the persist timer. Otherwise, 1069 * set the retransmit timer. 1070 */ 1071 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1072 (int32_t)(tp->snd_nxt - tp->snd_una) < 1073 (int32_t)sbavail(&so->so_snd)) 1074 tcp_setpersist(tp); 1075 else 1076 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1077 } 1078 1079 /* All non-embryonic sessions get a keepalive timer. */ 1080 if (!tcp_timer_active(tp, TT_KEEP)) 1081 tcp_timer_activate(tp, TT_KEEP, 1082 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1083 TP_KEEPINIT(tp)); 1084 1085 /* 1086 * Make sure critical variables are initialized 1087 * if transitioning while in Recovery. 1088 */ 1089 if IN_FASTRECOVERY(tp->t_flags) { 1090 if (tp->sackhint.recover_fs == 0) 1091 tp->sackhint.recover_fs = max(1, 1092 tp->snd_nxt - tp->snd_una); 1093 } 1094 1095 return (0); 1096 } 1097 1098 /* 1099 * tfb_tcp_fb_fini() function for the default stack. 1100 * 1101 * This changes state as necessary (or prudent) to prepare for another stack 1102 * to assume responsibility for the connection. 1103 */ 1104 static void 1105 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1106 { 1107 1108 INP_WLOCK_ASSERT(tp->t_inpcb); 1109 return; 1110 } 1111 1112 /* 1113 * Target size of TCP PCB hash tables. Must be a power of two. 1114 * 1115 * Note that this can be overridden by the kernel environment 1116 * variable net.inet.tcp.tcbhashsize 1117 */ 1118 #ifndef TCBHASHSIZE 1119 #define TCBHASHSIZE 0 1120 #endif 1121 1122 /* 1123 * XXX 1124 * Callouts should be moved into struct tcp directly. They are currently 1125 * separate because the tcpcb structure is exported to userland for sysctl 1126 * parsing purposes, which do not know about callouts. 1127 */ 1128 struct tcpcb_mem { 1129 struct tcpcb tcb; 1130 struct tcp_timer tt; 1131 struct cc_var ccv; 1132 #ifdef TCP_HHOOK 1133 struct osd osd; 1134 #endif 1135 }; 1136 1137 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1138 #define V_tcpcb_zone VNET(tcpcb_zone) 1139 1140 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1141 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1142 1143 static struct mtx isn_mtx; 1144 1145 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1146 #define ISN_LOCK() mtx_lock(&isn_mtx) 1147 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1148 1149 INPCBSTORAGE_DEFINE(tcpcbstor, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1150 1151 /* 1152 * Take a value and get the next power of 2 that doesn't overflow. 1153 * Used to size the tcp_inpcb hash buckets. 1154 */ 1155 static int 1156 maketcp_hashsize(int size) 1157 { 1158 int hashsize; 1159 1160 /* 1161 * auto tune. 1162 * get the next power of 2 higher than maxsockets. 1163 */ 1164 hashsize = 1 << fls(size); 1165 /* catch overflow, and just go one power of 2 smaller */ 1166 if (hashsize < size) { 1167 hashsize = 1 << (fls(size) - 1); 1168 } 1169 return (hashsize); 1170 } 1171 1172 static volatile int next_tcp_stack_id = 1; 1173 1174 /* 1175 * Register a TCP function block with the name provided in the names 1176 * array. (Note that this function does NOT automatically register 1177 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1178 * explicitly include blk->tfb_tcp_block_name in the list of names if 1179 * you wish to register the stack with that name.) 1180 * 1181 * Either all name registrations will succeed or all will fail. If 1182 * a name registration fails, the function will update the num_names 1183 * argument to point to the array index of the name that encountered 1184 * the failure. 1185 * 1186 * Returns 0 on success, or an error code on failure. 1187 */ 1188 int 1189 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1190 const char *names[], int *num_names) 1191 { 1192 struct tcp_function *n; 1193 struct tcp_function_set fs; 1194 int error, i; 1195 1196 KASSERT(names != NULL && *num_names > 0, 1197 ("%s: Called with 0-length name list", __func__)); 1198 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1199 KASSERT(rw_initialized(&tcp_function_lock), 1200 ("%s: called too early", __func__)); 1201 1202 if ((blk->tfb_tcp_output == NULL) || 1203 (blk->tfb_tcp_do_segment == NULL) || 1204 (blk->tfb_tcp_ctloutput == NULL) || 1205 (strlen(blk->tfb_tcp_block_name) == 0)) { 1206 /* 1207 * These functions are required and you 1208 * need a name. 1209 */ 1210 *num_names = 0; 1211 return (EINVAL); 1212 } 1213 if (blk->tfb_tcp_timer_stop_all || 1214 blk->tfb_tcp_timer_activate || 1215 blk->tfb_tcp_timer_active || 1216 blk->tfb_tcp_timer_stop) { 1217 /* 1218 * If you define one timer function you 1219 * must have them all. 1220 */ 1221 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1222 (blk->tfb_tcp_timer_activate == NULL) || 1223 (blk->tfb_tcp_timer_active == NULL) || 1224 (blk->tfb_tcp_timer_stop == NULL)) { 1225 *num_names = 0; 1226 return (EINVAL); 1227 } 1228 } 1229 1230 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1231 *num_names = 0; 1232 return (EINVAL); 1233 } 1234 1235 refcount_init(&blk->tfb_refcnt, 0); 1236 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1237 for (i = 0; i < *num_names; i++) { 1238 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1239 if (n == NULL) { 1240 error = ENOMEM; 1241 goto cleanup; 1242 } 1243 n->tf_fb = blk; 1244 1245 (void)strlcpy(fs.function_set_name, names[i], 1246 sizeof(fs.function_set_name)); 1247 rw_wlock(&tcp_function_lock); 1248 if (find_tcp_functions_locked(&fs) != NULL) { 1249 /* Duplicate name space not allowed */ 1250 rw_wunlock(&tcp_function_lock); 1251 free(n, M_TCPFUNCTIONS); 1252 error = EALREADY; 1253 goto cleanup; 1254 } 1255 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1256 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1257 tcp_fb_cnt++; 1258 rw_wunlock(&tcp_function_lock); 1259 } 1260 return(0); 1261 1262 cleanup: 1263 /* 1264 * Deregister the names we just added. Because registration failed 1265 * for names[i], we don't need to deregister that name. 1266 */ 1267 *num_names = i; 1268 rw_wlock(&tcp_function_lock); 1269 while (--i >= 0) { 1270 TAILQ_FOREACH(n, &t_functions, tf_next) { 1271 if (!strncmp(n->tf_name, names[i], 1272 TCP_FUNCTION_NAME_LEN_MAX)) { 1273 TAILQ_REMOVE(&t_functions, n, tf_next); 1274 tcp_fb_cnt--; 1275 n->tf_fb = NULL; 1276 free(n, M_TCPFUNCTIONS); 1277 break; 1278 } 1279 } 1280 } 1281 rw_wunlock(&tcp_function_lock); 1282 return (error); 1283 } 1284 1285 /* 1286 * Register a TCP function block using the name provided in the name 1287 * argument. 1288 * 1289 * Returns 0 on success, or an error code on failure. 1290 */ 1291 int 1292 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1293 int wait) 1294 { 1295 const char *name_list[1]; 1296 int num_names, rv; 1297 1298 num_names = 1; 1299 if (name != NULL) 1300 name_list[0] = name; 1301 else 1302 name_list[0] = blk->tfb_tcp_block_name; 1303 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1304 return (rv); 1305 } 1306 1307 /* 1308 * Register a TCP function block using the name defined in 1309 * blk->tfb_tcp_block_name. 1310 * 1311 * Returns 0 on success, or an error code on failure. 1312 */ 1313 int 1314 register_tcp_functions(struct tcp_function_block *blk, int wait) 1315 { 1316 1317 return (register_tcp_functions_as_name(blk, NULL, wait)); 1318 } 1319 1320 /* 1321 * Deregister all names associated with a function block. This 1322 * functionally removes the function block from use within the system. 1323 * 1324 * When called with a true quiesce argument, mark the function block 1325 * as being removed so no more stacks will use it and determine 1326 * whether the removal would succeed. 1327 * 1328 * When called with a false quiesce argument, actually attempt the 1329 * removal. 1330 * 1331 * When called with a force argument, attempt to switch all TCBs to 1332 * use the default stack instead of returning EBUSY. 1333 * 1334 * Returns 0 on success (or if the removal would succeed, or an error 1335 * code on failure. 1336 */ 1337 int 1338 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1339 bool force) 1340 { 1341 struct tcp_function *f; 1342 1343 if (blk == &tcp_def_funcblk) { 1344 /* You can't un-register the default */ 1345 return (EPERM); 1346 } 1347 rw_wlock(&tcp_function_lock); 1348 if (blk == tcp_func_set_ptr) { 1349 /* You can't free the current default */ 1350 rw_wunlock(&tcp_function_lock); 1351 return (EBUSY); 1352 } 1353 /* Mark the block so no more stacks can use it. */ 1354 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1355 /* 1356 * If TCBs are still attached to the stack, attempt to switch them 1357 * to the default stack. 1358 */ 1359 if (force && blk->tfb_refcnt) { 1360 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1361 INPLOOKUP_WLOCKPCB); 1362 struct inpcb *inp; 1363 struct tcpcb *tp; 1364 VNET_ITERATOR_DECL(vnet_iter); 1365 1366 rw_wunlock(&tcp_function_lock); 1367 1368 VNET_LIST_RLOCK(); 1369 VNET_FOREACH(vnet_iter) { 1370 CURVNET_SET(vnet_iter); 1371 while ((inp = inp_next(&inpi)) != NULL) { 1372 if (inp->inp_flags & INP_TIMEWAIT) 1373 continue; 1374 tp = intotcpcb(inp); 1375 if (tp == NULL || tp->t_fb != blk) 1376 continue; 1377 tcp_switch_back_to_default(tp); 1378 } 1379 CURVNET_RESTORE(); 1380 } 1381 VNET_LIST_RUNLOCK(); 1382 1383 rw_wlock(&tcp_function_lock); 1384 } 1385 if (blk->tfb_refcnt) { 1386 /* TCBs still attached. */ 1387 rw_wunlock(&tcp_function_lock); 1388 return (EBUSY); 1389 } 1390 if (quiesce) { 1391 /* Skip removal. */ 1392 rw_wunlock(&tcp_function_lock); 1393 return (0); 1394 } 1395 /* Remove any function names that map to this function block. */ 1396 while (find_tcp_fb_locked(blk, &f) != NULL) { 1397 TAILQ_REMOVE(&t_functions, f, tf_next); 1398 tcp_fb_cnt--; 1399 f->tf_fb = NULL; 1400 free(f, M_TCPFUNCTIONS); 1401 } 1402 rw_wunlock(&tcp_function_lock); 1403 return (0); 1404 } 1405 1406 static void 1407 tcp_vnet_init(void *arg __unused) 1408 { 1409 1410 #ifdef TCP_HHOOK 1411 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1412 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1413 printf("%s: WARNING: unable to register helper hook\n", __func__); 1414 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1415 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1416 printf("%s: WARNING: unable to register helper hook\n", __func__); 1417 #endif 1418 #ifdef STATS 1419 if (tcp_stats_init()) 1420 printf("%s: WARNING: unable to initialise TCP stats\n", 1421 __func__); 1422 #endif 1423 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1424 tcp_tcbhashsize); 1425 1426 /* 1427 * These have to be type stable for the benefit of the timers. 1428 */ 1429 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1430 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1431 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1432 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1433 1434 tcp_tw_init(); 1435 syncache_init(); 1436 tcp_hc_init(); 1437 1438 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1439 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1440 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1441 1442 tcp_fastopen_init(); 1443 1444 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1445 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1446 1447 V_tcp_msl = TCPTV_MSL; 1448 } 1449 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1450 tcp_vnet_init, NULL); 1451 1452 static void 1453 tcp_init(void *arg __unused) 1454 { 1455 const char *tcbhash_tuneable; 1456 int hashsize; 1457 1458 tcp_reass_global_init(); 1459 1460 /* XXX virtualize those below? */ 1461 tcp_delacktime = TCPTV_DELACK; 1462 tcp_keepinit = TCPTV_KEEP_INIT; 1463 tcp_keepidle = TCPTV_KEEP_IDLE; 1464 tcp_keepintvl = TCPTV_KEEPINTVL; 1465 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1466 tcp_rexmit_initial = TCPTV_RTOBASE; 1467 if (tcp_rexmit_initial < 1) 1468 tcp_rexmit_initial = 1; 1469 tcp_rexmit_min = TCPTV_MIN; 1470 if (tcp_rexmit_min < 1) 1471 tcp_rexmit_min = 1; 1472 tcp_persmin = TCPTV_PERSMIN; 1473 tcp_persmax = TCPTV_PERSMAX; 1474 tcp_rexmit_slop = TCPTV_CPU_VAR; 1475 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1476 1477 /* Setup the tcp function block list */ 1478 TAILQ_INIT(&t_functions); 1479 rw_init(&tcp_function_lock, "tcp_func_lock"); 1480 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1481 #ifdef TCP_BLACKBOX 1482 /* Initialize the TCP logging data. */ 1483 tcp_log_init(); 1484 #endif 1485 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1486 1487 if (tcp_soreceive_stream) { 1488 #ifdef INET 1489 tcp_usrreqs.pru_soreceive = soreceive_stream; 1490 #endif 1491 #ifdef INET6 1492 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1493 #endif /* INET6 */ 1494 } 1495 1496 #ifdef INET6 1497 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1498 #else /* INET6 */ 1499 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1500 #endif /* INET6 */ 1501 if (max_protohdr < TCP_MINPROTOHDR) 1502 max_protohdr = TCP_MINPROTOHDR; 1503 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1504 panic("tcp_init"); 1505 #undef TCP_MINPROTOHDR 1506 1507 ISN_LOCK_INIT(); 1508 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1509 SHUTDOWN_PRI_DEFAULT); 1510 1511 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1512 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1513 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1514 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1515 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1516 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1517 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1518 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1519 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1520 #ifdef TCPPCAP 1521 tcp_pcap_init(); 1522 #endif 1523 1524 hashsize = TCBHASHSIZE; 1525 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1526 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1527 if (hashsize == 0) { 1528 /* 1529 * Auto tune the hash size based on maxsockets. 1530 * A perfect hash would have a 1:1 mapping 1531 * (hashsize = maxsockets) however it's been 1532 * suggested that O(2) average is better. 1533 */ 1534 hashsize = maketcp_hashsize(maxsockets / 4); 1535 /* 1536 * Our historical default is 512, 1537 * do not autotune lower than this. 1538 */ 1539 if (hashsize < 512) 1540 hashsize = 512; 1541 if (bootverbose) 1542 printf("%s: %s auto tuned to %d\n", __func__, 1543 tcbhash_tuneable, hashsize); 1544 } 1545 /* 1546 * We require a hashsize to be a power of two. 1547 * Previously if it was not a power of two we would just reset it 1548 * back to 512, which could be a nasty surprise if you did not notice 1549 * the error message. 1550 * Instead what we do is clip it to the closest power of two lower 1551 * than the specified hash value. 1552 */ 1553 if (!powerof2(hashsize)) { 1554 int oldhashsize = hashsize; 1555 1556 hashsize = maketcp_hashsize(hashsize); 1557 /* prevent absurdly low value */ 1558 if (hashsize < 16) 1559 hashsize = 16; 1560 printf("%s: WARNING: TCB hash size not a power of 2, " 1561 "clipped from %d to %d.\n", __func__, oldhashsize, 1562 hashsize); 1563 } 1564 tcp_tcbhashsize = hashsize; 1565 } 1566 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1567 1568 #ifdef VIMAGE 1569 static void 1570 tcp_destroy(void *unused __unused) 1571 { 1572 int n; 1573 #ifdef TCP_HHOOK 1574 int error; 1575 #endif 1576 1577 /* 1578 * All our processes are gone, all our sockets should be cleaned 1579 * up, which means, we should be past the tcp_discardcb() calls. 1580 * Sleep to let all tcpcb timers really disappear and cleanup. 1581 */ 1582 for (;;) { 1583 INP_INFO_WLOCK(&V_tcbinfo); 1584 n = V_tcbinfo.ipi_count; 1585 INP_INFO_WUNLOCK(&V_tcbinfo); 1586 if (n == 0) 1587 break; 1588 pause("tcpdes", hz / 10); 1589 } 1590 tcp_hc_destroy(); 1591 syncache_destroy(); 1592 tcp_tw_destroy(); 1593 in_pcbinfo_destroy(&V_tcbinfo); 1594 /* tcp_discardcb() clears the sack_holes up. */ 1595 uma_zdestroy(V_sack_hole_zone); 1596 uma_zdestroy(V_tcpcb_zone); 1597 1598 /* 1599 * Cannot free the zone until all tcpcbs are released as we attach 1600 * the allocations to them. 1601 */ 1602 tcp_fastopen_destroy(); 1603 1604 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1605 VNET_PCPUSTAT_FREE(tcpstat); 1606 1607 #ifdef TCP_HHOOK 1608 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1609 if (error != 0) { 1610 printf("%s: WARNING: unable to deregister helper hook " 1611 "type=%d, id=%d: error %d returned\n", __func__, 1612 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1613 } 1614 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1615 if (error != 0) { 1616 printf("%s: WARNING: unable to deregister helper hook " 1617 "type=%d, id=%d: error %d returned\n", __func__, 1618 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1619 } 1620 #endif 1621 } 1622 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1623 #endif 1624 1625 void 1626 tcp_fini(void *xtp) 1627 { 1628 1629 } 1630 1631 /* 1632 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1633 * tcp_template used to store this data in mbufs, but we now recopy it out 1634 * of the tcpcb each time to conserve mbufs. 1635 */ 1636 void 1637 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1638 { 1639 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1640 1641 INP_WLOCK_ASSERT(inp); 1642 1643 #ifdef INET6 1644 if ((inp->inp_vflag & INP_IPV6) != 0) { 1645 struct ip6_hdr *ip6; 1646 1647 ip6 = (struct ip6_hdr *)ip_ptr; 1648 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1649 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1650 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1651 (IPV6_VERSION & IPV6_VERSION_MASK); 1652 if (port == 0) 1653 ip6->ip6_nxt = IPPROTO_TCP; 1654 else 1655 ip6->ip6_nxt = IPPROTO_UDP; 1656 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1657 ip6->ip6_src = inp->in6p_laddr; 1658 ip6->ip6_dst = inp->in6p_faddr; 1659 } 1660 #endif /* INET6 */ 1661 #if defined(INET6) && defined(INET) 1662 else 1663 #endif 1664 #ifdef INET 1665 { 1666 struct ip *ip; 1667 1668 ip = (struct ip *)ip_ptr; 1669 ip->ip_v = IPVERSION; 1670 ip->ip_hl = 5; 1671 ip->ip_tos = inp->inp_ip_tos; 1672 ip->ip_len = 0; 1673 ip->ip_id = 0; 1674 ip->ip_off = 0; 1675 ip->ip_ttl = inp->inp_ip_ttl; 1676 ip->ip_sum = 0; 1677 if (port == 0) 1678 ip->ip_p = IPPROTO_TCP; 1679 else 1680 ip->ip_p = IPPROTO_UDP; 1681 ip->ip_src = inp->inp_laddr; 1682 ip->ip_dst = inp->inp_faddr; 1683 } 1684 #endif /* INET */ 1685 th->th_sport = inp->inp_lport; 1686 th->th_dport = inp->inp_fport; 1687 th->th_seq = 0; 1688 th->th_ack = 0; 1689 th->th_off = 5; 1690 tcp_set_flags(th, 0); 1691 th->th_win = 0; 1692 th->th_urp = 0; 1693 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1694 } 1695 1696 /* 1697 * Create template to be used to send tcp packets on a connection. 1698 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1699 * use for this function is in keepalives, which use tcp_respond. 1700 */ 1701 struct tcptemp * 1702 tcpip_maketemplate(struct inpcb *inp) 1703 { 1704 struct tcptemp *t; 1705 1706 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1707 if (t == NULL) 1708 return (NULL); 1709 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1710 return (t); 1711 } 1712 1713 /* 1714 * Send a single message to the TCP at address specified by 1715 * the given TCP/IP header. If m == NULL, then we make a copy 1716 * of the tcpiphdr at th and send directly to the addressed host. 1717 * This is used to force keep alive messages out using the TCP 1718 * template for a connection. If flags are given then we send 1719 * a message back to the TCP which originated the segment th, 1720 * and discard the mbuf containing it and any other attached mbufs. 1721 * 1722 * In any case the ack and sequence number of the transmitted 1723 * segment are as specified by the parameters. 1724 * 1725 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1726 */ 1727 void 1728 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1729 tcp_seq ack, tcp_seq seq, int flags) 1730 { 1731 struct tcpopt to; 1732 struct inpcb *inp; 1733 struct ip *ip; 1734 struct mbuf *optm; 1735 struct udphdr *uh = NULL; 1736 struct tcphdr *nth; 1737 struct tcp_log_buffer *lgb; 1738 u_char *optp; 1739 #ifdef INET6 1740 struct ip6_hdr *ip6; 1741 int isipv6; 1742 #endif /* INET6 */ 1743 int optlen, tlen, win, ulen; 1744 bool incl_opts; 1745 uint16_t port; 1746 int output_ret; 1747 #ifdef INVARIANTS 1748 int thflags = tcp_get_flags(th); 1749 #endif 1750 1751 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1752 NET_EPOCH_ASSERT(); 1753 1754 #ifdef INET6 1755 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1756 ip6 = ipgen; 1757 #endif /* INET6 */ 1758 ip = ipgen; 1759 1760 if (tp != NULL) { 1761 inp = tp->t_inpcb; 1762 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1763 INP_LOCK_ASSERT(inp); 1764 } else 1765 inp = NULL; 1766 1767 if (m != NULL) { 1768 #ifdef INET6 1769 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1770 port = m->m_pkthdr.tcp_tun_port; 1771 else 1772 #endif 1773 if (ip && (ip->ip_p == IPPROTO_UDP)) 1774 port = m->m_pkthdr.tcp_tun_port; 1775 else 1776 port = 0; 1777 } else 1778 port = tp->t_port; 1779 1780 incl_opts = false; 1781 win = 0; 1782 if (tp != NULL) { 1783 if (!(flags & TH_RST)) { 1784 win = sbspace(&inp->inp_socket->so_rcv); 1785 if (win > TCP_MAXWIN << tp->rcv_scale) 1786 win = TCP_MAXWIN << tp->rcv_scale; 1787 } 1788 if ((tp->t_flags & TF_NOOPT) == 0) 1789 incl_opts = true; 1790 } 1791 if (m == NULL) { 1792 m = m_gethdr(M_NOWAIT, MT_DATA); 1793 if (m == NULL) 1794 return; 1795 m->m_data += max_linkhdr; 1796 #ifdef INET6 1797 if (isipv6) { 1798 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1799 sizeof(struct ip6_hdr)); 1800 ip6 = mtod(m, struct ip6_hdr *); 1801 nth = (struct tcphdr *)(ip6 + 1); 1802 if (port) { 1803 /* Insert a UDP header */ 1804 uh = (struct udphdr *)nth; 1805 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1806 uh->uh_dport = port; 1807 nth = (struct tcphdr *)(uh + 1); 1808 } 1809 } else 1810 #endif /* INET6 */ 1811 { 1812 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1813 ip = mtod(m, struct ip *); 1814 nth = (struct tcphdr *)(ip + 1); 1815 if (port) { 1816 /* Insert a UDP header */ 1817 uh = (struct udphdr *)nth; 1818 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1819 uh->uh_dport = port; 1820 nth = (struct tcphdr *)(uh + 1); 1821 } 1822 } 1823 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1824 flags = TH_ACK; 1825 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1826 struct mbuf *n; 1827 1828 /* Can't reuse 'm', allocate a new mbuf. */ 1829 n = m_gethdr(M_NOWAIT, MT_DATA); 1830 if (n == NULL) { 1831 m_freem(m); 1832 return; 1833 } 1834 1835 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1836 m_freem(m); 1837 m_freem(n); 1838 return; 1839 } 1840 1841 n->m_data += max_linkhdr; 1842 /* m_len is set later */ 1843 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1844 #ifdef INET6 1845 if (isipv6) { 1846 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1847 sizeof(struct ip6_hdr)); 1848 ip6 = mtod(n, struct ip6_hdr *); 1849 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1850 nth = (struct tcphdr *)(ip6 + 1); 1851 if (port) { 1852 /* Insert a UDP header */ 1853 uh = (struct udphdr *)nth; 1854 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1855 uh->uh_dport = port; 1856 nth = (struct tcphdr *)(uh + 1); 1857 } 1858 } else 1859 #endif /* INET6 */ 1860 { 1861 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1862 ip = mtod(n, struct ip *); 1863 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1864 nth = (struct tcphdr *)(ip + 1); 1865 if (port) { 1866 /* Insert a UDP header */ 1867 uh = (struct udphdr *)nth; 1868 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1869 uh->uh_dport = port; 1870 nth = (struct tcphdr *)(uh + 1); 1871 } 1872 } 1873 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1874 xchg(nth->th_dport, nth->th_sport, uint16_t); 1875 th = nth; 1876 m_freem(m); 1877 m = n; 1878 } else { 1879 /* 1880 * reuse the mbuf. 1881 * XXX MRT We inherit the FIB, which is lucky. 1882 */ 1883 m_freem(m->m_next); 1884 m->m_next = NULL; 1885 m->m_data = (caddr_t)ipgen; 1886 /* m_len is set later */ 1887 #ifdef INET6 1888 if (isipv6) { 1889 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1890 nth = (struct tcphdr *)(ip6 + 1); 1891 } else 1892 #endif /* INET6 */ 1893 { 1894 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1895 nth = (struct tcphdr *)(ip + 1); 1896 } 1897 if (th != nth) { 1898 /* 1899 * this is usually a case when an extension header 1900 * exists between the IPv6 header and the 1901 * TCP header. 1902 */ 1903 nth->th_sport = th->th_sport; 1904 nth->th_dport = th->th_dport; 1905 } 1906 xchg(nth->th_dport, nth->th_sport, uint16_t); 1907 #undef xchg 1908 } 1909 tlen = 0; 1910 #ifdef INET6 1911 if (isipv6) 1912 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1913 #endif 1914 #if defined(INET) && defined(INET6) 1915 else 1916 #endif 1917 #ifdef INET 1918 tlen = sizeof (struct tcpiphdr); 1919 #endif 1920 if (port) 1921 tlen += sizeof (struct udphdr); 1922 #ifdef INVARIANTS 1923 m->m_len = 0; 1924 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1925 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1926 m, tlen, (long)M_TRAILINGSPACE(m))); 1927 #endif 1928 m->m_len = tlen; 1929 to.to_flags = 0; 1930 if (incl_opts) { 1931 /* Make sure we have room. */ 1932 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1933 m->m_next = m_get(M_NOWAIT, MT_DATA); 1934 if (m->m_next) { 1935 optp = mtod(m->m_next, u_char *); 1936 optm = m->m_next; 1937 } else 1938 incl_opts = false; 1939 } else { 1940 optp = (u_char *) (nth + 1); 1941 optm = m; 1942 } 1943 } 1944 if (incl_opts) { 1945 /* Timestamps. */ 1946 if (tp->t_flags & TF_RCVD_TSTMP) { 1947 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1948 to.to_tsecr = tp->ts_recent; 1949 to.to_flags |= TOF_TS; 1950 } 1951 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1952 /* TCP-MD5 (RFC2385). */ 1953 if (tp->t_flags & TF_SIGNATURE) 1954 to.to_flags |= TOF_SIGNATURE; 1955 #endif 1956 /* Add the options. */ 1957 tlen += optlen = tcp_addoptions(&to, optp); 1958 1959 /* Update m_len in the correct mbuf. */ 1960 optm->m_len += optlen; 1961 } else 1962 optlen = 0; 1963 #ifdef INET6 1964 if (isipv6) { 1965 if (uh) { 1966 ulen = tlen - sizeof(struct ip6_hdr); 1967 uh->uh_ulen = htons(ulen); 1968 } 1969 ip6->ip6_flow = 0; 1970 ip6->ip6_vfc = IPV6_VERSION; 1971 if (port) 1972 ip6->ip6_nxt = IPPROTO_UDP; 1973 else 1974 ip6->ip6_nxt = IPPROTO_TCP; 1975 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1976 } 1977 #endif 1978 #if defined(INET) && defined(INET6) 1979 else 1980 #endif 1981 #ifdef INET 1982 { 1983 if (uh) { 1984 ulen = tlen - sizeof(struct ip); 1985 uh->uh_ulen = htons(ulen); 1986 } 1987 ip->ip_len = htons(tlen); 1988 ip->ip_ttl = V_ip_defttl; 1989 if (port) { 1990 ip->ip_p = IPPROTO_UDP; 1991 } else { 1992 ip->ip_p = IPPROTO_TCP; 1993 } 1994 if (V_path_mtu_discovery) 1995 ip->ip_off |= htons(IP_DF); 1996 } 1997 #endif 1998 m->m_pkthdr.len = tlen; 1999 m->m_pkthdr.rcvif = NULL; 2000 #ifdef MAC 2001 if (inp != NULL) { 2002 /* 2003 * Packet is associated with a socket, so allow the 2004 * label of the response to reflect the socket label. 2005 */ 2006 INP_LOCK_ASSERT(inp); 2007 mac_inpcb_create_mbuf(inp, m); 2008 } else { 2009 /* 2010 * Packet is not associated with a socket, so possibly 2011 * update the label in place. 2012 */ 2013 mac_netinet_tcp_reply(m); 2014 } 2015 #endif 2016 nth->th_seq = htonl(seq); 2017 nth->th_ack = htonl(ack); 2018 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2019 tcp_set_flags(nth, flags); 2020 if (tp != NULL) 2021 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2022 else 2023 nth->th_win = htons((u_short)win); 2024 nth->th_urp = 0; 2025 2026 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2027 if (to.to_flags & TOF_SIGNATURE) { 2028 if (!TCPMD5_ENABLED() || 2029 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2030 m_freem(m); 2031 return; 2032 } 2033 } 2034 #endif 2035 2036 #ifdef INET6 2037 if (isipv6) { 2038 if (port) { 2039 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2040 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2041 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2042 nth->th_sum = 0; 2043 } else { 2044 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2045 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2046 nth->th_sum = in6_cksum_pseudo(ip6, 2047 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2048 } 2049 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2050 NULL, NULL); 2051 } 2052 #endif /* INET6 */ 2053 #if defined(INET6) && defined(INET) 2054 else 2055 #endif 2056 #ifdef INET 2057 { 2058 if (port) { 2059 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2060 htons(ulen + IPPROTO_UDP)); 2061 m->m_pkthdr.csum_flags = CSUM_UDP; 2062 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2063 nth->th_sum = 0; 2064 } else { 2065 m->m_pkthdr.csum_flags = CSUM_TCP; 2066 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2067 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2068 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2069 } 2070 } 2071 #endif /* INET */ 2072 #ifdef TCPDEBUG 2073 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2074 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2075 #endif 2076 TCP_PROBE3(debug__output, tp, th, m); 2077 if (flags & TH_RST) 2078 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2079 lgb = NULL; 2080 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2081 if (INP_WLOCKED(inp)) { 2082 union tcp_log_stackspecific log; 2083 struct timeval tv; 2084 2085 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2086 log.u_bbr.inhpts = tp->t_inpcb->inp_in_hpts; 2087 log.u_bbr.flex8 = 4; 2088 log.u_bbr.pkts_out = tp->t_maxseg; 2089 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2090 log.u_bbr.delivered = 0; 2091 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2092 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2093 } else { 2094 /* 2095 * We can not log the packet, since we only own the 2096 * read lock, but a write lock is needed. The read lock 2097 * is not upgraded to a write lock, since only getting 2098 * the read lock was done intentionally to improve the 2099 * handling of SYN flooding attacks. 2100 * This happens only for pure SYN segments received in 2101 * the initial CLOSED state, or received in a more 2102 * advanced state than listen and the UDP encapsulation 2103 * port is unexpected. 2104 * The incoming SYN segments do not really belong to 2105 * the TCP connection and the handling does not change 2106 * the state of the TCP connection. Therefore, the 2107 * sending of the RST segments is not logged. Please 2108 * note that also the incoming SYN segments are not 2109 * logged. 2110 * 2111 * The following code ensures that the above description 2112 * is and stays correct. 2113 */ 2114 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2115 (tp->t_state == TCPS_CLOSED || 2116 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2117 ("%s: Logging of TCP segment with flags 0x%b and " 2118 "UDP encapsulation port %u skipped in state %s", 2119 __func__, thflags, PRINT_TH_FLAGS, 2120 ntohs(port), tcpstates[tp->t_state])); 2121 } 2122 } 2123 2124 #ifdef INET6 2125 if (isipv6) { 2126 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2127 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2128 } 2129 #endif /* INET6 */ 2130 #if defined(INET) && defined(INET6) 2131 else 2132 #endif 2133 #ifdef INET 2134 { 2135 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2136 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2137 } 2138 #endif 2139 if (lgb != NULL) 2140 lgb->tlb_errno = output_ret; 2141 } 2142 2143 /* 2144 * Create a new TCP control block, making an 2145 * empty reassembly queue and hooking it to the argument 2146 * protocol control block. The `inp' parameter must have 2147 * come from the zone allocator set up in tcp_init(). 2148 */ 2149 struct tcpcb * 2150 tcp_newtcpcb(struct inpcb *inp) 2151 { 2152 struct tcpcb_mem *tm; 2153 struct tcpcb *tp; 2154 #ifdef INET6 2155 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2156 #endif /* INET6 */ 2157 2158 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2159 if (tm == NULL) 2160 return (NULL); 2161 tp = &tm->tcb; 2162 2163 /* Initialise cc_var struct for this tcpcb. */ 2164 tp->ccv = &tm->ccv; 2165 tp->ccv->type = IPPROTO_TCP; 2166 tp->ccv->ccvc.tcp = tp; 2167 rw_rlock(&tcp_function_lock); 2168 tp->t_fb = tcp_func_set_ptr; 2169 refcount_acquire(&tp->t_fb->tfb_refcnt); 2170 rw_runlock(&tcp_function_lock); 2171 /* 2172 * Use the current system default CC algorithm. 2173 */ 2174 cc_attach(tp, CC_DEFAULT_ALGO()); 2175 2176 /* 2177 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2178 * is called. 2179 */ 2180 in_pcbref(inp); /* Reference for tcpcb */ 2181 tp->t_inpcb = inp; 2182 2183 if (CC_ALGO(tp)->cb_init != NULL) 2184 if (CC_ALGO(tp)->cb_init(tp->ccv, NULL) > 0) { 2185 cc_detach(tp); 2186 if (tp->t_fb->tfb_tcp_fb_fini) 2187 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2188 in_pcbrele_wlocked(inp); 2189 refcount_release(&tp->t_fb->tfb_refcnt); 2190 uma_zfree(V_tcpcb_zone, tm); 2191 return (NULL); 2192 } 2193 2194 #ifdef TCP_HHOOK 2195 tp->osd = &tm->osd; 2196 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2197 if (tp->t_fb->tfb_tcp_fb_fini) 2198 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2199 in_pcbrele_wlocked(inp); 2200 refcount_release(&tp->t_fb->tfb_refcnt); 2201 uma_zfree(V_tcpcb_zone, tm); 2202 return (NULL); 2203 } 2204 #endif 2205 2206 #ifdef VIMAGE 2207 tp->t_vnet = inp->inp_vnet; 2208 #endif 2209 tp->t_timers = &tm->tt; 2210 TAILQ_INIT(&tp->t_segq); 2211 tp->t_maxseg = 2212 #ifdef INET6 2213 isipv6 ? V_tcp_v6mssdflt : 2214 #endif /* INET6 */ 2215 V_tcp_mssdflt; 2216 2217 /* Set up our timeouts. */ 2218 callout_init(&tp->t_timers->tt_rexmt, 1); 2219 callout_init(&tp->t_timers->tt_persist, 1); 2220 callout_init(&tp->t_timers->tt_keep, 1); 2221 callout_init(&tp->t_timers->tt_2msl, 1); 2222 callout_init(&tp->t_timers->tt_delack, 1); 2223 2224 if (V_tcp_do_rfc1323) 2225 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2226 if (V_tcp_do_sack) 2227 tp->t_flags |= TF_SACK_PERMIT; 2228 TAILQ_INIT(&tp->snd_holes); 2229 2230 /* 2231 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2232 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2233 * reasonable initial retransmit time. 2234 */ 2235 tp->t_srtt = TCPTV_SRTTBASE; 2236 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2237 tp->t_rttmin = tcp_rexmit_min; 2238 tp->t_rxtcur = tcp_rexmit_initial; 2239 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2240 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2241 tp->t_rcvtime = ticks; 2242 /* 2243 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2244 * because the socket may be bound to an IPv6 wildcard address, 2245 * which may match an IPv4-mapped IPv6 address. 2246 */ 2247 inp->inp_ip_ttl = V_ip_defttl; 2248 inp->inp_ppcb = tp; 2249 #ifdef TCPPCAP 2250 /* 2251 * Init the TCP PCAP queues. 2252 */ 2253 tcp_pcap_tcpcb_init(tp); 2254 #endif 2255 #ifdef TCP_BLACKBOX 2256 /* Initialize the per-TCPCB log data. */ 2257 tcp_log_tcpcbinit(tp); 2258 #endif 2259 tp->t_pacing_rate = -1; 2260 if (tp->t_fb->tfb_tcp_fb_init) { 2261 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2262 refcount_release(&tp->t_fb->tfb_refcnt); 2263 in_pcbrele_wlocked(inp); 2264 uma_zfree(V_tcpcb_zone, tm); 2265 return (NULL); 2266 } 2267 } 2268 #ifdef STATS 2269 if (V_tcp_perconn_stats_enable == 1) 2270 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2271 #endif 2272 if (V_tcp_do_lrd) 2273 tp->t_flags |= TF_LRD; 2274 return (tp); /* XXX */ 2275 } 2276 2277 /* 2278 * Drop a TCP connection, reporting 2279 * the specified error. If connection is synchronized, 2280 * then send a RST to peer. 2281 */ 2282 struct tcpcb * 2283 tcp_drop(struct tcpcb *tp, int errno) 2284 { 2285 struct socket *so = tp->t_inpcb->inp_socket; 2286 2287 NET_EPOCH_ASSERT(); 2288 INP_WLOCK_ASSERT(tp->t_inpcb); 2289 2290 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2291 tcp_state_change(tp, TCPS_CLOSED); 2292 /* Don't use tcp_output() here due to possible recursion. */ 2293 (void)tcp_output_nodrop(tp); 2294 TCPSTAT_INC(tcps_drops); 2295 } else 2296 TCPSTAT_INC(tcps_conndrops); 2297 if (errno == ETIMEDOUT && tp->t_softerror) 2298 errno = tp->t_softerror; 2299 so->so_error = errno; 2300 return (tcp_close(tp)); 2301 } 2302 2303 void 2304 tcp_discardcb(struct tcpcb *tp) 2305 { 2306 struct inpcb *inp = tp->t_inpcb; 2307 2308 INP_WLOCK_ASSERT(inp); 2309 2310 /* 2311 * Make sure that all of our timers are stopped before we delete the 2312 * PCB. 2313 * 2314 * If stopping a timer fails, we schedule a discard function in same 2315 * callout, and the last discard function called will take care of 2316 * deleting the tcpcb. 2317 */ 2318 tp->t_timers->tt_draincnt = 0; 2319 tcp_timer_stop(tp, TT_REXMT); 2320 tcp_timer_stop(tp, TT_PERSIST); 2321 tcp_timer_stop(tp, TT_KEEP); 2322 tcp_timer_stop(tp, TT_2MSL); 2323 tcp_timer_stop(tp, TT_DELACK); 2324 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2325 /* 2326 * Call the stop-all function of the methods, 2327 * this function should call the tcp_timer_stop() 2328 * method with each of the function specific timeouts. 2329 * That stop will be called via the tfb_tcp_timer_stop() 2330 * which should use the async drain function of the 2331 * callout system (see tcp_var.h). 2332 */ 2333 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2334 } 2335 2336 /* free the reassembly queue, if any */ 2337 tcp_reass_flush(tp); 2338 2339 #ifdef TCP_OFFLOAD 2340 /* Disconnect offload device, if any. */ 2341 if (tp->t_flags & TF_TOE) 2342 tcp_offload_detach(tp); 2343 #endif 2344 2345 tcp_free_sackholes(tp); 2346 2347 #ifdef TCPPCAP 2348 /* Free the TCP PCAP queues. */ 2349 tcp_pcap_drain(&(tp->t_inpkts)); 2350 tcp_pcap_drain(&(tp->t_outpkts)); 2351 #endif 2352 2353 /* Allow the CC algorithm to clean up after itself. */ 2354 if (CC_ALGO(tp)->cb_destroy != NULL) 2355 CC_ALGO(tp)->cb_destroy(tp->ccv); 2356 CC_DATA(tp) = NULL; 2357 /* Detach from the CC algorithm */ 2358 cc_detach(tp); 2359 2360 #ifdef TCP_HHOOK 2361 khelp_destroy_osd(tp->osd); 2362 #endif 2363 #ifdef STATS 2364 stats_blob_destroy(tp->t_stats); 2365 #endif 2366 2367 CC_ALGO(tp) = NULL; 2368 inp->inp_ppcb = NULL; 2369 if (tp->t_timers->tt_draincnt == 0) { 2370 bool released __diagused; 2371 2372 released = tcp_freecb(tp); 2373 KASSERT(!released, ("%s: inp %p should not have been released " 2374 "here", __func__, inp)); 2375 } 2376 } 2377 2378 bool 2379 tcp_freecb(struct tcpcb *tp) 2380 { 2381 struct inpcb *inp = tp->t_inpcb; 2382 struct socket *so = inp->inp_socket; 2383 #ifdef INET6 2384 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2385 #endif 2386 2387 INP_WLOCK_ASSERT(inp); 2388 MPASS(tp->t_timers->tt_draincnt == 0); 2389 2390 /* We own the last reference on tcpcb, let's free it. */ 2391 #ifdef TCP_BLACKBOX 2392 tcp_log_tcpcbfini(tp); 2393 #endif 2394 TCPSTATES_DEC(tp->t_state); 2395 if (tp->t_fb->tfb_tcp_fb_fini) 2396 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2397 2398 /* 2399 * If we got enough samples through the srtt filter, 2400 * save the rtt and rttvar in the routing entry. 2401 * 'Enough' is arbitrarily defined as 4 rtt samples. 2402 * 4 samples is enough for the srtt filter to converge 2403 * to within enough % of the correct value; fewer samples 2404 * and we could save a bogus rtt. The danger is not high 2405 * as tcp quickly recovers from everything. 2406 * XXX: Works very well but needs some more statistics! 2407 * 2408 * XXXRRS: Updating must be after the stack fini() since 2409 * that may be converting some internal representation of 2410 * say srtt etc into the general one used by other stacks. 2411 * Lets also at least protect against the so being NULL 2412 * as RW stated below. 2413 */ 2414 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2415 struct hc_metrics_lite metrics; 2416 uint32_t ssthresh; 2417 2418 bzero(&metrics, sizeof(metrics)); 2419 /* 2420 * Update the ssthresh always when the conditions below 2421 * are satisfied. This gives us better new start value 2422 * for the congestion avoidance for new connections. 2423 * ssthresh is only set if packet loss occurred on a session. 2424 * 2425 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2426 * being torn down. Ideally this code would not use 'so'. 2427 */ 2428 ssthresh = tp->snd_ssthresh; 2429 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2430 /* 2431 * convert the limit from user data bytes to 2432 * packets then to packet data bytes. 2433 */ 2434 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2435 if (ssthresh < 2) 2436 ssthresh = 2; 2437 ssthresh *= (tp->t_maxseg + 2438 #ifdef INET6 2439 (isipv6 ? sizeof (struct ip6_hdr) + 2440 sizeof (struct tcphdr) : 2441 #endif 2442 sizeof (struct tcpiphdr) 2443 #ifdef INET6 2444 ) 2445 #endif 2446 ); 2447 } else 2448 ssthresh = 0; 2449 metrics.rmx_ssthresh = ssthresh; 2450 2451 metrics.rmx_rtt = tp->t_srtt; 2452 metrics.rmx_rttvar = tp->t_rttvar; 2453 metrics.rmx_cwnd = tp->snd_cwnd; 2454 metrics.rmx_sendpipe = 0; 2455 metrics.rmx_recvpipe = 0; 2456 2457 tcp_hc_update(&inp->inp_inc, &metrics); 2458 } 2459 2460 refcount_release(&tp->t_fb->tfb_refcnt); 2461 uma_zfree(V_tcpcb_zone, tp); 2462 2463 return (in_pcbrele_wlocked(inp)); 2464 } 2465 2466 /* 2467 * Attempt to close a TCP control block, marking it as dropped, and freeing 2468 * the socket if we hold the only reference. 2469 */ 2470 struct tcpcb * 2471 tcp_close(struct tcpcb *tp) 2472 { 2473 struct inpcb *inp = tp->t_inpcb; 2474 struct socket *so; 2475 2476 INP_WLOCK_ASSERT(inp); 2477 2478 #ifdef TCP_OFFLOAD 2479 if (tp->t_state == TCPS_LISTEN) 2480 tcp_offload_listen_stop(tp); 2481 #endif 2482 /* 2483 * This releases the TFO pending counter resource for TFO listen 2484 * sockets as well as passively-created TFO sockets that transition 2485 * from SYN_RECEIVED to CLOSED. 2486 */ 2487 if (tp->t_tfo_pending) { 2488 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2489 tp->t_tfo_pending = NULL; 2490 } 2491 #ifdef TCPHPTS 2492 tcp_hpts_remove(inp); 2493 #endif 2494 in_pcbdrop(inp); 2495 TCPSTAT_INC(tcps_closed); 2496 if (tp->t_state != TCPS_CLOSED) 2497 tcp_state_change(tp, TCPS_CLOSED); 2498 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2499 so = inp->inp_socket; 2500 soisdisconnected(so); 2501 if (inp->inp_flags & INP_SOCKREF) { 2502 KASSERT(so->so_state & SS_PROTOREF, 2503 ("tcp_close: !SS_PROTOREF")); 2504 inp->inp_flags &= ~INP_SOCKREF; 2505 INP_WUNLOCK(inp); 2506 SOCK_LOCK(so); 2507 so->so_state &= ~SS_PROTOREF; 2508 sofree(so); 2509 return (NULL); 2510 } 2511 return (tp); 2512 } 2513 2514 void 2515 tcp_drain(void) 2516 { 2517 VNET_ITERATOR_DECL(vnet_iter); 2518 2519 if (!do_tcpdrain) 2520 return; 2521 2522 VNET_LIST_RLOCK_NOSLEEP(); 2523 VNET_FOREACH(vnet_iter) { 2524 CURVNET_SET(vnet_iter); 2525 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2526 INPLOOKUP_WLOCKPCB); 2527 struct inpcb *inpb; 2528 struct tcpcb *tcpb; 2529 2530 /* 2531 * Walk the tcpbs, if existing, and flush the reassembly queue, 2532 * if there is one... 2533 * XXX: The "Net/3" implementation doesn't imply that the TCP 2534 * reassembly queue should be flushed, but in a situation 2535 * where we're really low on mbufs, this is potentially 2536 * useful. 2537 */ 2538 while ((inpb = inp_next(&inpi)) != NULL) { 2539 if (inpb->inp_flags & INP_TIMEWAIT) 2540 continue; 2541 if ((tcpb = intotcpcb(inpb)) != NULL) { 2542 tcp_reass_flush(tcpb); 2543 tcp_clean_sackreport(tcpb); 2544 #ifdef TCP_BLACKBOX 2545 tcp_log_drain(tcpb); 2546 #endif 2547 #ifdef TCPPCAP 2548 if (tcp_pcap_aggressive_free) { 2549 /* Free the TCP PCAP queues. */ 2550 tcp_pcap_drain(&(tcpb->t_inpkts)); 2551 tcp_pcap_drain(&(tcpb->t_outpkts)); 2552 } 2553 #endif 2554 } 2555 } 2556 CURVNET_RESTORE(); 2557 } 2558 VNET_LIST_RUNLOCK_NOSLEEP(); 2559 } 2560 2561 /* 2562 * Notify a tcp user of an asynchronous error; 2563 * store error as soft error, but wake up user 2564 * (for now, won't do anything until can select for soft error). 2565 * 2566 * Do not wake up user since there currently is no mechanism for 2567 * reporting soft errors (yet - a kqueue filter may be added). 2568 */ 2569 static struct inpcb * 2570 tcp_notify(struct inpcb *inp, int error) 2571 { 2572 struct tcpcb *tp; 2573 2574 INP_WLOCK_ASSERT(inp); 2575 2576 if ((inp->inp_flags & INP_TIMEWAIT) || 2577 (inp->inp_flags & INP_DROPPED)) 2578 return (inp); 2579 2580 tp = intotcpcb(inp); 2581 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2582 2583 /* 2584 * Ignore some errors if we are hooked up. 2585 * If connection hasn't completed, has retransmitted several times, 2586 * and receives a second error, give up now. This is better 2587 * than waiting a long time to establish a connection that 2588 * can never complete. 2589 */ 2590 if (tp->t_state == TCPS_ESTABLISHED && 2591 (error == EHOSTUNREACH || error == ENETUNREACH || 2592 error == EHOSTDOWN)) { 2593 if (inp->inp_route.ro_nh) { 2594 NH_FREE(inp->inp_route.ro_nh); 2595 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2596 } 2597 return (inp); 2598 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2599 tp->t_softerror) { 2600 tp = tcp_drop(tp, error); 2601 if (tp != NULL) 2602 return (inp); 2603 else 2604 return (NULL); 2605 } else { 2606 tp->t_softerror = error; 2607 return (inp); 2608 } 2609 #if 0 2610 wakeup( &so->so_timeo); 2611 sorwakeup(so); 2612 sowwakeup(so); 2613 #endif 2614 } 2615 2616 static int 2617 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2618 { 2619 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2620 INPLOOKUP_RLOCKPCB); 2621 struct xinpgen xig; 2622 struct inpcb *inp; 2623 int error; 2624 2625 if (req->newptr != NULL) 2626 return (EPERM); 2627 2628 if (req->oldptr == NULL) { 2629 int n; 2630 2631 n = V_tcbinfo.ipi_count + 2632 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2633 n += imax(n / 8, 10); 2634 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2635 return (0); 2636 } 2637 2638 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2639 return (error); 2640 2641 bzero(&xig, sizeof(xig)); 2642 xig.xig_len = sizeof xig; 2643 xig.xig_count = V_tcbinfo.ipi_count + 2644 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2645 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2646 xig.xig_sogen = so_gencnt; 2647 error = SYSCTL_OUT(req, &xig, sizeof xig); 2648 if (error) 2649 return (error); 2650 2651 error = syncache_pcblist(req); 2652 if (error) 2653 return (error); 2654 2655 while ((inp = inp_next(&inpi)) != NULL) { 2656 if (inp->inp_gencnt <= xig.xig_gen) { 2657 int crerr; 2658 2659 /* 2660 * XXX: This use of cr_cansee(), introduced with 2661 * TCP state changes, is not quite right, but for 2662 * now, better than nothing. 2663 */ 2664 if (inp->inp_flags & INP_TIMEWAIT) { 2665 if (intotw(inp) != NULL) 2666 crerr = cr_cansee(req->td->td_ucred, 2667 intotw(inp)->tw_cred); 2668 else 2669 crerr = EINVAL; /* Skip this inp. */ 2670 } else 2671 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2672 if (crerr == 0) { 2673 struct xtcpcb xt; 2674 2675 tcp_inptoxtp(inp, &xt); 2676 error = SYSCTL_OUT(req, &xt, sizeof xt); 2677 if (error) { 2678 INP_RUNLOCK(inp); 2679 break; 2680 } else 2681 continue; 2682 } 2683 } 2684 } 2685 2686 if (!error) { 2687 /* 2688 * Give the user an updated idea of our state. 2689 * If the generation differs from what we told 2690 * her before, she knows that something happened 2691 * while we were processing this request, and it 2692 * might be necessary to retry. 2693 */ 2694 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2695 xig.xig_sogen = so_gencnt; 2696 xig.xig_count = V_tcbinfo.ipi_count + 2697 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2698 error = SYSCTL_OUT(req, &xig, sizeof xig); 2699 } 2700 2701 return (error); 2702 } 2703 2704 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2705 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2706 NULL, 0, tcp_pcblist, "S,xtcpcb", 2707 "List of active TCP connections"); 2708 2709 #ifdef INET 2710 static int 2711 tcp_getcred(SYSCTL_HANDLER_ARGS) 2712 { 2713 struct xucred xuc; 2714 struct sockaddr_in addrs[2]; 2715 struct epoch_tracker et; 2716 struct inpcb *inp; 2717 int error; 2718 2719 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2720 if (error) 2721 return (error); 2722 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2723 if (error) 2724 return (error); 2725 NET_EPOCH_ENTER(et); 2726 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2727 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2728 NET_EPOCH_EXIT(et); 2729 if (inp != NULL) { 2730 if (inp->inp_socket == NULL) 2731 error = ENOENT; 2732 if (error == 0) 2733 error = cr_canseeinpcb(req->td->td_ucred, inp); 2734 if (error == 0) 2735 cru2x(inp->inp_cred, &xuc); 2736 INP_RUNLOCK(inp); 2737 } else 2738 error = ENOENT; 2739 if (error == 0) 2740 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2741 return (error); 2742 } 2743 2744 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2745 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2746 0, 0, tcp_getcred, "S,xucred", 2747 "Get the xucred of a TCP connection"); 2748 #endif /* INET */ 2749 2750 #ifdef INET6 2751 static int 2752 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2753 { 2754 struct epoch_tracker et; 2755 struct xucred xuc; 2756 struct sockaddr_in6 addrs[2]; 2757 struct inpcb *inp; 2758 int error; 2759 #ifdef INET 2760 int mapped = 0; 2761 #endif 2762 2763 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2764 if (error) 2765 return (error); 2766 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2767 if (error) 2768 return (error); 2769 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2770 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2771 return (error); 2772 } 2773 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2774 #ifdef INET 2775 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2776 mapped = 1; 2777 else 2778 #endif 2779 return (EINVAL); 2780 } 2781 2782 NET_EPOCH_ENTER(et); 2783 #ifdef INET 2784 if (mapped == 1) 2785 inp = in_pcblookup(&V_tcbinfo, 2786 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2787 addrs[1].sin6_port, 2788 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2789 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2790 else 2791 #endif 2792 inp = in6_pcblookup(&V_tcbinfo, 2793 &addrs[1].sin6_addr, addrs[1].sin6_port, 2794 &addrs[0].sin6_addr, addrs[0].sin6_port, 2795 INPLOOKUP_RLOCKPCB, NULL); 2796 NET_EPOCH_EXIT(et); 2797 if (inp != NULL) { 2798 if (inp->inp_socket == NULL) 2799 error = ENOENT; 2800 if (error == 0) 2801 error = cr_canseeinpcb(req->td->td_ucred, inp); 2802 if (error == 0) 2803 cru2x(inp->inp_cred, &xuc); 2804 INP_RUNLOCK(inp); 2805 } else 2806 error = ENOENT; 2807 if (error == 0) 2808 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2809 return (error); 2810 } 2811 2812 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2813 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2814 0, 0, tcp6_getcred, "S,xucred", 2815 "Get the xucred of a TCP6 connection"); 2816 #endif /* INET6 */ 2817 2818 #ifdef INET 2819 /* Path MTU to try next when a fragmentation-needed message is received. */ 2820 static inline int 2821 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2822 { 2823 int mtu = ntohs(icp->icmp_nextmtu); 2824 2825 /* If no alternative MTU was proposed, try the next smaller one. */ 2826 if (!mtu) 2827 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2828 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2829 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2830 2831 return (mtu); 2832 } 2833 2834 static void 2835 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2836 { 2837 struct ip *ip = vip; 2838 struct tcphdr *th; 2839 struct in_addr faddr; 2840 struct inpcb *inp; 2841 struct tcpcb *tp; 2842 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2843 struct icmp *icp; 2844 struct in_conninfo inc; 2845 tcp_seq icmp_tcp_seq; 2846 int mtu; 2847 2848 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2849 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2850 return; 2851 2852 if (cmd == PRC_MSGSIZE) 2853 notify = tcp_mtudisc_notify; 2854 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2855 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2856 cmd == PRC_TIMXCEED_INTRANS) && ip) 2857 notify = tcp_drop_syn_sent; 2858 2859 /* 2860 * Hostdead is ugly because it goes linearly through all PCBs. 2861 * XXX: We never get this from ICMP, otherwise it makes an 2862 * excellent DoS attack on machines with many connections. 2863 */ 2864 else if (cmd == PRC_HOSTDEAD) 2865 ip = NULL; 2866 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2867 return; 2868 2869 if (ip == NULL) { 2870 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2871 return; 2872 } 2873 2874 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2875 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2876 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2877 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2878 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2879 /* signal EHOSTDOWN, as it flushes the cached route */ 2880 inp = (*notify)(inp, EHOSTDOWN); 2881 goto out; 2882 } 2883 icmp_tcp_seq = th->th_seq; 2884 if (inp != NULL) { 2885 if (!(inp->inp_flags & INP_TIMEWAIT) && 2886 !(inp->inp_flags & INP_DROPPED) && 2887 !(inp->inp_socket == NULL)) { 2888 tp = intotcpcb(inp); 2889 #ifdef TCP_OFFLOAD 2890 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2891 /* 2892 * MTU discovery for offloaded connections. Let 2893 * the TOE driver verify seq# and process it. 2894 */ 2895 mtu = tcp_next_pmtu(icp, ip); 2896 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2897 goto out; 2898 } 2899 #endif 2900 if (tp->t_port != port) { 2901 goto out; 2902 } 2903 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2904 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2905 if (cmd == PRC_MSGSIZE) { 2906 /* 2907 * MTU discovery: we got a needfrag and 2908 * will potentially try a lower MTU. 2909 */ 2910 mtu = tcp_next_pmtu(icp, ip); 2911 2912 /* 2913 * Only process the offered MTU if it 2914 * is smaller than the current one. 2915 */ 2916 if (mtu < tp->t_maxseg + 2917 sizeof(struct tcpiphdr)) { 2918 bzero(&inc, sizeof(inc)); 2919 inc.inc_faddr = faddr; 2920 inc.inc_fibnum = 2921 inp->inp_inc.inc_fibnum; 2922 tcp_hc_updatemtu(&inc, mtu); 2923 inp = tcp_mtudisc(inp, mtu); 2924 } 2925 } else 2926 inp = (*notify)(inp, 2927 inetctlerrmap[cmd]); 2928 } 2929 } 2930 } else { 2931 bzero(&inc, sizeof(inc)); 2932 inc.inc_fport = th->th_dport; 2933 inc.inc_lport = th->th_sport; 2934 inc.inc_faddr = faddr; 2935 inc.inc_laddr = ip->ip_src; 2936 syncache_unreach(&inc, icmp_tcp_seq, port); 2937 } 2938 out: 2939 if (inp != NULL) 2940 INP_WUNLOCK(inp); 2941 } 2942 2943 void 2944 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2945 { 2946 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2947 } 2948 2949 void 2950 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2951 { 2952 /* Its a tunneled TCP over UDP icmp */ 2953 struct ip *outer_ip, *inner_ip; 2954 struct icmp *icmp; 2955 struct udphdr *udp; 2956 struct tcphdr *th, ttemp; 2957 int i_hlen, o_len; 2958 uint16_t port; 2959 2960 inner_ip = (struct ip *)vip; 2961 icmp = (struct icmp *)((caddr_t)inner_ip - 2962 (sizeof(struct icmp) - sizeof(struct ip))); 2963 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2964 i_hlen = inner_ip->ip_hl << 2; 2965 o_len = ntohs(outer_ip->ip_len); 2966 if (o_len < 2967 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2968 /* Not enough data present */ 2969 return; 2970 } 2971 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2972 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2973 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2974 return; 2975 } 2976 port = udp->uh_dport; 2977 th = (struct tcphdr *)(udp + 1); 2978 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2979 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2980 /* Now adjust down the size of the outer IP header */ 2981 o_len -= sizeof(struct udphdr); 2982 outer_ip->ip_len = htons(o_len); 2983 /* Now call in to the normal handling code */ 2984 tcp_ctlinput_with_port(cmd, sa, vip, port); 2985 } 2986 #endif /* INET */ 2987 2988 #ifdef INET6 2989 static inline int 2990 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2991 { 2992 int mtu = ntohl(icmp6->icmp6_mtu); 2993 2994 /* 2995 * If no alternative MTU was proposed, or the proposed MTU was too 2996 * small, set to the min. 2997 */ 2998 if (mtu < IPV6_MMTU) 2999 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3000 return (mtu); 3001 } 3002 3003 static void 3004 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3005 { 3006 struct in6_addr *dst; 3007 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3008 struct ip6_hdr *ip6; 3009 struct mbuf *m; 3010 struct inpcb *inp; 3011 struct tcpcb *tp; 3012 struct icmp6_hdr *icmp6; 3013 struct ip6ctlparam *ip6cp = NULL; 3014 const struct sockaddr_in6 *sa6_src = NULL; 3015 struct in_conninfo inc; 3016 struct tcp_ports { 3017 uint16_t th_sport; 3018 uint16_t th_dport; 3019 } t_ports; 3020 tcp_seq icmp_tcp_seq; 3021 unsigned int mtu; 3022 unsigned int off; 3023 3024 if (sa->sa_family != AF_INET6 || 3025 sa->sa_len != sizeof(struct sockaddr_in6)) 3026 return; 3027 3028 /* if the parameter is from icmp6, decode it. */ 3029 if (d != NULL) { 3030 ip6cp = (struct ip6ctlparam *)d; 3031 icmp6 = ip6cp->ip6c_icmp6; 3032 m = ip6cp->ip6c_m; 3033 ip6 = ip6cp->ip6c_ip6; 3034 off = ip6cp->ip6c_off; 3035 sa6_src = ip6cp->ip6c_src; 3036 dst = ip6cp->ip6c_finaldst; 3037 } else { 3038 m = NULL; 3039 ip6 = NULL; 3040 off = 0; /* fool gcc */ 3041 sa6_src = &sa6_any; 3042 dst = NULL; 3043 } 3044 3045 if (cmd == PRC_MSGSIZE) 3046 notify = tcp_mtudisc_notify; 3047 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3048 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3049 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3050 notify = tcp_drop_syn_sent; 3051 3052 /* 3053 * Hostdead is ugly because it goes linearly through all PCBs. 3054 * XXX: We never get this from ICMP, otherwise it makes an 3055 * excellent DoS attack on machines with many connections. 3056 */ 3057 else if (cmd == PRC_HOSTDEAD) 3058 ip6 = NULL; 3059 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3060 return; 3061 3062 if (ip6 == NULL) { 3063 in6_pcbnotify(&V_tcbinfo, sa, 0, 3064 (const struct sockaddr *)sa6_src, 3065 0, cmd, NULL, notify); 3066 return; 3067 } 3068 3069 /* Check if we can safely get the ports from the tcp hdr */ 3070 if (m == NULL || 3071 (m->m_pkthdr.len < 3072 (int32_t) (off + sizeof(struct tcp_ports)))) { 3073 return; 3074 } 3075 bzero(&t_ports, sizeof(struct tcp_ports)); 3076 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3077 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3078 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3079 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3080 /* signal EHOSTDOWN, as it flushes the cached route */ 3081 inp = (*notify)(inp, EHOSTDOWN); 3082 goto out; 3083 } 3084 off += sizeof(struct tcp_ports); 3085 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3086 goto out; 3087 } 3088 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3089 if (inp != NULL) { 3090 if (!(inp->inp_flags & INP_TIMEWAIT) && 3091 !(inp->inp_flags & INP_DROPPED) && 3092 !(inp->inp_socket == NULL)) { 3093 tp = intotcpcb(inp); 3094 #ifdef TCP_OFFLOAD 3095 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3096 /* MTU discovery for offloaded connections. */ 3097 mtu = tcp6_next_pmtu(icmp6); 3098 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3099 goto out; 3100 } 3101 #endif 3102 if (tp->t_port != port) { 3103 goto out; 3104 } 3105 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3106 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3107 if (cmd == PRC_MSGSIZE) { 3108 /* 3109 * MTU discovery: 3110 * If we got a needfrag set the MTU 3111 * in the route to the suggested new 3112 * value (if given) and then notify. 3113 */ 3114 mtu = tcp6_next_pmtu(icmp6); 3115 3116 bzero(&inc, sizeof(inc)); 3117 inc.inc_fibnum = M_GETFIB(m); 3118 inc.inc_flags |= INC_ISIPV6; 3119 inc.inc6_faddr = *dst; 3120 if (in6_setscope(&inc.inc6_faddr, 3121 m->m_pkthdr.rcvif, NULL)) 3122 goto out; 3123 /* 3124 * Only process the offered MTU if it 3125 * is smaller than the current one. 3126 */ 3127 if (mtu < tp->t_maxseg + 3128 sizeof (struct tcphdr) + 3129 sizeof (struct ip6_hdr)) { 3130 tcp_hc_updatemtu(&inc, mtu); 3131 tcp_mtudisc(inp, mtu); 3132 ICMP6STAT_INC(icp6s_pmtuchg); 3133 } 3134 } else 3135 inp = (*notify)(inp, 3136 inet6ctlerrmap[cmd]); 3137 } 3138 } 3139 } else { 3140 bzero(&inc, sizeof(inc)); 3141 inc.inc_fibnum = M_GETFIB(m); 3142 inc.inc_flags |= INC_ISIPV6; 3143 inc.inc_fport = t_ports.th_dport; 3144 inc.inc_lport = t_ports.th_sport; 3145 inc.inc6_faddr = *dst; 3146 inc.inc6_laddr = ip6->ip6_src; 3147 syncache_unreach(&inc, icmp_tcp_seq, port); 3148 } 3149 out: 3150 if (inp != NULL) 3151 INP_WUNLOCK(inp); 3152 } 3153 3154 void 3155 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3156 { 3157 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3158 } 3159 3160 void 3161 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3162 { 3163 struct ip6ctlparam *ip6cp; 3164 struct mbuf *m; 3165 struct udphdr *udp; 3166 uint16_t port; 3167 3168 ip6cp = (struct ip6ctlparam *)d; 3169 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3170 if (m == NULL) { 3171 return; 3172 } 3173 udp = mtod(m, struct udphdr *); 3174 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3175 return; 3176 } 3177 port = udp->uh_dport; 3178 m_adj(m, sizeof(struct udphdr)); 3179 if ((m->m_flags & M_PKTHDR) == 0) { 3180 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3181 } 3182 /* Now call in to the normal handling code */ 3183 tcp6_ctlinput_with_port(cmd, sa, d, port); 3184 } 3185 3186 #endif /* INET6 */ 3187 3188 static uint32_t 3189 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3190 { 3191 SIPHASH_CTX ctx; 3192 uint32_t hash[2]; 3193 3194 KASSERT(len >= SIPHASH_KEY_LENGTH, 3195 ("%s: keylen %u too short ", __func__, len)); 3196 SipHash24_Init(&ctx); 3197 SipHash_SetKey(&ctx, (uint8_t *)key); 3198 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3199 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3200 switch (inc->inc_flags & INC_ISIPV6) { 3201 #ifdef INET 3202 case 0: 3203 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3204 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3205 break; 3206 #endif 3207 #ifdef INET6 3208 case INC_ISIPV6: 3209 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3210 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3211 break; 3212 #endif 3213 } 3214 SipHash_Final((uint8_t *)hash, &ctx); 3215 3216 return (hash[0] ^ hash[1]); 3217 } 3218 3219 uint32_t 3220 tcp_new_ts_offset(struct in_conninfo *inc) 3221 { 3222 struct in_conninfo inc_store, *local_inc; 3223 3224 if (!V_tcp_ts_offset_per_conn) { 3225 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3226 inc_store.inc_lport = 0; 3227 inc_store.inc_fport = 0; 3228 local_inc = &inc_store; 3229 } else { 3230 local_inc = inc; 3231 } 3232 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3233 sizeof(V_ts_offset_secret))); 3234 } 3235 3236 /* 3237 * Following is where TCP initial sequence number generation occurs. 3238 * 3239 * There are two places where we must use initial sequence numbers: 3240 * 1. In SYN-ACK packets. 3241 * 2. In SYN packets. 3242 * 3243 * All ISNs for SYN-ACK packets are generated by the syncache. See 3244 * tcp_syncache.c for details. 3245 * 3246 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3247 * depends on this property. In addition, these ISNs should be 3248 * unguessable so as to prevent connection hijacking. To satisfy 3249 * the requirements of this situation, the algorithm outlined in 3250 * RFC 1948 is used, with only small modifications. 3251 * 3252 * Implementation details: 3253 * 3254 * Time is based off the system timer, and is corrected so that it 3255 * increases by one megabyte per second. This allows for proper 3256 * recycling on high speed LANs while still leaving over an hour 3257 * before rollover. 3258 * 3259 * As reading the *exact* system time is too expensive to be done 3260 * whenever setting up a TCP connection, we increment the time 3261 * offset in two ways. First, a small random positive increment 3262 * is added to isn_offset for each connection that is set up. 3263 * Second, the function tcp_isn_tick fires once per clock tick 3264 * and increments isn_offset as necessary so that sequence numbers 3265 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3266 * random positive increments serve only to ensure that the same 3267 * exact sequence number is never sent out twice (as could otherwise 3268 * happen when a port is recycled in less than the system tick 3269 * interval.) 3270 * 3271 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3272 * between seeding of isn_secret. This is normally set to zero, 3273 * as reseeding should not be necessary. 3274 * 3275 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3276 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3277 * general, this means holding an exclusive (write) lock. 3278 */ 3279 3280 #define ISN_BYTES_PER_SECOND 1048576 3281 #define ISN_STATIC_INCREMENT 4096 3282 #define ISN_RANDOM_INCREMENT (4096 - 1) 3283 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3284 3285 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3286 VNET_DEFINE_STATIC(int, isn_last); 3287 VNET_DEFINE_STATIC(int, isn_last_reseed); 3288 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3289 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3290 3291 #define V_isn_secret VNET(isn_secret) 3292 #define V_isn_last VNET(isn_last) 3293 #define V_isn_last_reseed VNET(isn_last_reseed) 3294 #define V_isn_offset VNET(isn_offset) 3295 #define V_isn_offset_old VNET(isn_offset_old) 3296 3297 tcp_seq 3298 tcp_new_isn(struct in_conninfo *inc) 3299 { 3300 tcp_seq new_isn; 3301 u_int32_t projected_offset; 3302 3303 ISN_LOCK(); 3304 /* Seed if this is the first use, reseed if requested. */ 3305 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3306 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3307 < (u_int)ticks))) { 3308 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3309 V_isn_last_reseed = ticks; 3310 } 3311 3312 /* Compute the hash and return the ISN. */ 3313 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3314 sizeof(V_isn_secret)); 3315 V_isn_offset += ISN_STATIC_INCREMENT + 3316 (arc4random() & ISN_RANDOM_INCREMENT); 3317 if (ticks != V_isn_last) { 3318 projected_offset = V_isn_offset_old + 3319 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3320 if (SEQ_GT(projected_offset, V_isn_offset)) 3321 V_isn_offset = projected_offset; 3322 V_isn_offset_old = V_isn_offset; 3323 V_isn_last = ticks; 3324 } 3325 new_isn += V_isn_offset; 3326 ISN_UNLOCK(); 3327 return (new_isn); 3328 } 3329 3330 /* 3331 * When a specific ICMP unreachable message is received and the 3332 * connection state is SYN-SENT, drop the connection. This behavior 3333 * is controlled by the icmp_may_rst sysctl. 3334 */ 3335 struct inpcb * 3336 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3337 { 3338 struct tcpcb *tp; 3339 3340 NET_EPOCH_ASSERT(); 3341 INP_WLOCK_ASSERT(inp); 3342 3343 if ((inp->inp_flags & INP_TIMEWAIT) || 3344 (inp->inp_flags & INP_DROPPED)) 3345 return (inp); 3346 3347 tp = intotcpcb(inp); 3348 if (tp->t_state != TCPS_SYN_SENT) 3349 return (inp); 3350 3351 if (IS_FASTOPEN(tp->t_flags)) 3352 tcp_fastopen_disable_path(tp); 3353 3354 tp = tcp_drop(tp, errno); 3355 if (tp != NULL) 3356 return (inp); 3357 else 3358 return (NULL); 3359 } 3360 3361 /* 3362 * When `need fragmentation' ICMP is received, update our idea of the MSS 3363 * based on the new value. Also nudge TCP to send something, since we 3364 * know the packet we just sent was dropped. 3365 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3366 */ 3367 static struct inpcb * 3368 tcp_mtudisc_notify(struct inpcb *inp, int error) 3369 { 3370 3371 return (tcp_mtudisc(inp, -1)); 3372 } 3373 3374 static struct inpcb * 3375 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3376 { 3377 struct tcpcb *tp; 3378 struct socket *so; 3379 3380 INP_WLOCK_ASSERT(inp); 3381 if ((inp->inp_flags & INP_TIMEWAIT) || 3382 (inp->inp_flags & INP_DROPPED)) 3383 return (inp); 3384 3385 tp = intotcpcb(inp); 3386 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3387 3388 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3389 3390 so = inp->inp_socket; 3391 SOCKBUF_LOCK(&so->so_snd); 3392 /* If the mss is larger than the socket buffer, decrease the mss. */ 3393 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3394 tp->t_maxseg = so->so_snd.sb_hiwat; 3395 SOCKBUF_UNLOCK(&so->so_snd); 3396 3397 TCPSTAT_INC(tcps_mturesent); 3398 tp->t_rtttime = 0; 3399 tp->snd_nxt = tp->snd_una; 3400 tcp_free_sackholes(tp); 3401 tp->snd_recover = tp->snd_max; 3402 if (tp->t_flags & TF_SACK_PERMIT) 3403 EXIT_FASTRECOVERY(tp->t_flags); 3404 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3405 /* 3406 * Conceptually the snd_nxt setting 3407 * and freeing sack holes should 3408 * be done by the default stacks 3409 * own tfb_tcp_mtu_chg(). 3410 */ 3411 tp->t_fb->tfb_tcp_mtu_chg(tp); 3412 } 3413 if (tcp_output(tp) < 0) 3414 return (NULL); 3415 else 3416 return (inp); 3417 } 3418 3419 #ifdef INET 3420 /* 3421 * Look-up the routing entry to the peer of this inpcb. If no route 3422 * is found and it cannot be allocated, then return 0. This routine 3423 * is called by TCP routines that access the rmx structure and by 3424 * tcp_mss_update to get the peer/interface MTU. 3425 */ 3426 uint32_t 3427 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3428 { 3429 struct nhop_object *nh; 3430 struct ifnet *ifp; 3431 uint32_t maxmtu = 0; 3432 3433 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3434 3435 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3436 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3437 if (nh == NULL) 3438 return (0); 3439 3440 ifp = nh->nh_ifp; 3441 maxmtu = nh->nh_mtu; 3442 3443 /* Report additional interface capabilities. */ 3444 if (cap != NULL) { 3445 if (ifp->if_capenable & IFCAP_TSO4 && 3446 ifp->if_hwassist & CSUM_TSO) { 3447 cap->ifcap |= CSUM_TSO; 3448 cap->tsomax = ifp->if_hw_tsomax; 3449 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3450 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3451 } 3452 } 3453 } 3454 return (maxmtu); 3455 } 3456 #endif /* INET */ 3457 3458 #ifdef INET6 3459 uint32_t 3460 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3461 { 3462 struct nhop_object *nh; 3463 struct in6_addr dst6; 3464 uint32_t scopeid; 3465 struct ifnet *ifp; 3466 uint32_t maxmtu = 0; 3467 3468 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3469 3470 if (inc->inc_flags & INC_IPV6MINMTU) 3471 return (IPV6_MMTU); 3472 3473 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3474 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3475 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3476 if (nh == NULL) 3477 return (0); 3478 3479 ifp = nh->nh_ifp; 3480 maxmtu = nh->nh_mtu; 3481 3482 /* Report additional interface capabilities. */ 3483 if (cap != NULL) { 3484 if (ifp->if_capenable & IFCAP_TSO6 && 3485 ifp->if_hwassist & CSUM_TSO) { 3486 cap->ifcap |= CSUM_TSO; 3487 cap->tsomax = ifp->if_hw_tsomax; 3488 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3489 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3490 } 3491 } 3492 } 3493 3494 return (maxmtu); 3495 } 3496 3497 /* 3498 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3499 * 3500 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3501 * The right place to do that is ip6_setpktopt() that has just been 3502 * executed. By the way it just filled ip6po_minmtu for us. 3503 */ 3504 void 3505 tcp6_use_min_mtu(struct tcpcb *tp) 3506 { 3507 struct inpcb *inp = tp->t_inpcb; 3508 3509 INP_WLOCK_ASSERT(inp); 3510 /* 3511 * In case of the IPV6_USE_MIN_MTU socket 3512 * option, the INC_IPV6MINMTU flag to announce 3513 * a corresponding MSS during the initial 3514 * handshake. If the TCP connection is not in 3515 * the front states, just reduce the MSS being 3516 * used. This avoids the sending of TCP 3517 * segments which will be fragmented at the 3518 * IPv6 layer. 3519 */ 3520 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3521 if ((tp->t_state >= TCPS_SYN_SENT) && 3522 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3523 struct ip6_pktopts *opt; 3524 3525 opt = inp->in6p_outputopts; 3526 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3527 tp->t_maxseg > TCP6_MSS) 3528 tp->t_maxseg = TCP6_MSS; 3529 } 3530 } 3531 #endif /* INET6 */ 3532 3533 /* 3534 * Calculate effective SMSS per RFC5681 definition for a given TCP 3535 * connection at its current state, taking into account SACK and etc. 3536 */ 3537 u_int 3538 tcp_maxseg(const struct tcpcb *tp) 3539 { 3540 u_int optlen; 3541 3542 if (tp->t_flags & TF_NOOPT) 3543 return (tp->t_maxseg); 3544 3545 /* 3546 * Here we have a simplified code from tcp_addoptions(), 3547 * without a proper loop, and having most of paddings hardcoded. 3548 * We might make mistakes with padding here in some edge cases, 3549 * but this is harmless, since result of tcp_maxseg() is used 3550 * only in cwnd and ssthresh estimations. 3551 */ 3552 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3553 if (tp->t_flags & TF_RCVD_TSTMP) 3554 optlen = TCPOLEN_TSTAMP_APPA; 3555 else 3556 optlen = 0; 3557 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3558 if (tp->t_flags & TF_SIGNATURE) 3559 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3560 #endif 3561 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3562 optlen += TCPOLEN_SACKHDR; 3563 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3564 optlen = PADTCPOLEN(optlen); 3565 } 3566 } else { 3567 if (tp->t_flags & TF_REQ_TSTMP) 3568 optlen = TCPOLEN_TSTAMP_APPA; 3569 else 3570 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3571 if (tp->t_flags & TF_REQ_SCALE) 3572 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3573 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3574 if (tp->t_flags & TF_SIGNATURE) 3575 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3576 #endif 3577 if (tp->t_flags & TF_SACK_PERMIT) 3578 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3579 } 3580 #undef PAD 3581 optlen = min(optlen, TCP_MAXOLEN); 3582 return (tp->t_maxseg - optlen); 3583 } 3584 3585 3586 u_int 3587 tcp_fixed_maxseg(const struct tcpcb *tp) 3588 { 3589 int optlen; 3590 3591 if (tp->t_flags & TF_NOOPT) 3592 return (tp->t_maxseg); 3593 3594 /* 3595 * Here we have a simplified code from tcp_addoptions(), 3596 * without a proper loop, and having most of paddings hardcoded. 3597 * We only consider fixed options that we would send every 3598 * time I.e. SACK is not considered. This is important 3599 * for cc modules to figure out what the modulo of the 3600 * cwnd should be. 3601 */ 3602 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3603 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3604 if (tp->t_flags & TF_RCVD_TSTMP) 3605 optlen = TCPOLEN_TSTAMP_APPA; 3606 else 3607 optlen = 0; 3608 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3609 if (tp->t_flags & TF_SIGNATURE) 3610 optlen += PAD(TCPOLEN_SIGNATURE); 3611 #endif 3612 } else { 3613 if (tp->t_flags & TF_REQ_TSTMP) 3614 optlen = TCPOLEN_TSTAMP_APPA; 3615 else 3616 optlen = PAD(TCPOLEN_MAXSEG); 3617 if (tp->t_flags & TF_REQ_SCALE) 3618 optlen += PAD(TCPOLEN_WINDOW); 3619 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3620 if (tp->t_flags & TF_SIGNATURE) 3621 optlen += PAD(TCPOLEN_SIGNATURE); 3622 #endif 3623 if (tp->t_flags & TF_SACK_PERMIT) 3624 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3625 } 3626 #undef PAD 3627 optlen = min(optlen, TCP_MAXOLEN); 3628 return (tp->t_maxseg - optlen); 3629 } 3630 3631 3632 3633 static int 3634 sysctl_drop(SYSCTL_HANDLER_ARGS) 3635 { 3636 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3637 struct sockaddr_storage addrs[2]; 3638 struct inpcb *inp; 3639 struct tcpcb *tp; 3640 struct tcptw *tw; 3641 struct sockaddr_in *fin, *lin; 3642 struct epoch_tracker et; 3643 #ifdef INET6 3644 struct sockaddr_in6 *fin6, *lin6; 3645 #endif 3646 int error; 3647 3648 inp = NULL; 3649 fin = lin = NULL; 3650 #ifdef INET6 3651 fin6 = lin6 = NULL; 3652 #endif 3653 error = 0; 3654 3655 if (req->oldptr != NULL || req->oldlen != 0) 3656 return (EINVAL); 3657 if (req->newptr == NULL) 3658 return (EPERM); 3659 if (req->newlen < sizeof(addrs)) 3660 return (ENOMEM); 3661 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3662 if (error) 3663 return (error); 3664 3665 switch (addrs[0].ss_family) { 3666 #ifdef INET6 3667 case AF_INET6: 3668 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3669 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3670 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3671 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3672 return (EINVAL); 3673 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3674 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3675 return (EINVAL); 3676 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3677 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3678 fin = (struct sockaddr_in *)&addrs[0]; 3679 lin = (struct sockaddr_in *)&addrs[1]; 3680 break; 3681 } 3682 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3683 if (error) 3684 return (error); 3685 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3686 if (error) 3687 return (error); 3688 break; 3689 #endif 3690 #ifdef INET 3691 case AF_INET: 3692 fin = (struct sockaddr_in *)&addrs[0]; 3693 lin = (struct sockaddr_in *)&addrs[1]; 3694 if (fin->sin_len != sizeof(struct sockaddr_in) || 3695 lin->sin_len != sizeof(struct sockaddr_in)) 3696 return (EINVAL); 3697 break; 3698 #endif 3699 default: 3700 return (EINVAL); 3701 } 3702 NET_EPOCH_ENTER(et); 3703 switch (addrs[0].ss_family) { 3704 #ifdef INET6 3705 case AF_INET6: 3706 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3707 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3708 INPLOOKUP_WLOCKPCB, NULL); 3709 break; 3710 #endif 3711 #ifdef INET 3712 case AF_INET: 3713 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3714 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3715 break; 3716 #endif 3717 } 3718 if (inp != NULL) { 3719 if (inp->inp_flags & INP_TIMEWAIT) { 3720 /* 3721 * XXXRW: There currently exists a state where an 3722 * inpcb is present, but its timewait state has been 3723 * discarded. For now, don't allow dropping of this 3724 * type of inpcb. 3725 */ 3726 tw = intotw(inp); 3727 if (tw != NULL) 3728 tcp_twclose(tw, 0); 3729 else 3730 INP_WUNLOCK(inp); 3731 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3732 !SOLISTENING(inp->inp_socket)) { 3733 tp = intotcpcb(inp); 3734 tp = tcp_drop(tp, ECONNABORTED); 3735 if (tp != NULL) 3736 INP_WUNLOCK(inp); 3737 } else 3738 INP_WUNLOCK(inp); 3739 } else 3740 error = ESRCH; 3741 NET_EPOCH_EXIT(et); 3742 return (error); 3743 } 3744 3745 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3746 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3747 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3748 "Drop TCP connection"); 3749 3750 static int 3751 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3752 { 3753 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3754 &tcp_ctloutput_set)); 3755 } 3756 3757 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3758 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3759 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3760 "Set socket option for TCP endpoint"); 3761 3762 #ifdef KERN_TLS 3763 static int 3764 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3765 { 3766 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3767 struct sockaddr_storage addrs[2]; 3768 struct inpcb *inp; 3769 struct sockaddr_in *fin, *lin; 3770 struct epoch_tracker et; 3771 #ifdef INET6 3772 struct sockaddr_in6 *fin6, *lin6; 3773 #endif 3774 int error; 3775 3776 inp = NULL; 3777 fin = lin = NULL; 3778 #ifdef INET6 3779 fin6 = lin6 = NULL; 3780 #endif 3781 error = 0; 3782 3783 if (req->oldptr != NULL || req->oldlen != 0) 3784 return (EINVAL); 3785 if (req->newptr == NULL) 3786 return (EPERM); 3787 if (req->newlen < sizeof(addrs)) 3788 return (ENOMEM); 3789 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3790 if (error) 3791 return (error); 3792 3793 switch (addrs[0].ss_family) { 3794 #ifdef INET6 3795 case AF_INET6: 3796 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3797 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3798 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3799 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3800 return (EINVAL); 3801 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3802 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3803 return (EINVAL); 3804 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3805 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3806 fin = (struct sockaddr_in *)&addrs[0]; 3807 lin = (struct sockaddr_in *)&addrs[1]; 3808 break; 3809 } 3810 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3811 if (error) 3812 return (error); 3813 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3814 if (error) 3815 return (error); 3816 break; 3817 #endif 3818 #ifdef INET 3819 case AF_INET: 3820 fin = (struct sockaddr_in *)&addrs[0]; 3821 lin = (struct sockaddr_in *)&addrs[1]; 3822 if (fin->sin_len != sizeof(struct sockaddr_in) || 3823 lin->sin_len != sizeof(struct sockaddr_in)) 3824 return (EINVAL); 3825 break; 3826 #endif 3827 default: 3828 return (EINVAL); 3829 } 3830 NET_EPOCH_ENTER(et); 3831 switch (addrs[0].ss_family) { 3832 #ifdef INET6 3833 case AF_INET6: 3834 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3835 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3836 INPLOOKUP_WLOCKPCB, NULL); 3837 break; 3838 #endif 3839 #ifdef INET 3840 case AF_INET: 3841 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3842 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3843 break; 3844 #endif 3845 } 3846 NET_EPOCH_EXIT(et); 3847 if (inp != NULL) { 3848 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3849 inp->inp_socket == NULL) { 3850 error = ECONNRESET; 3851 INP_WUNLOCK(inp); 3852 } else { 3853 struct socket *so; 3854 3855 so = inp->inp_socket; 3856 soref(so); 3857 error = ktls_set_tx_mode(so, 3858 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3859 INP_WUNLOCK(inp); 3860 sorele(so); 3861 } 3862 } else 3863 error = ESRCH; 3864 return (error); 3865 } 3866 3867 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3868 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3869 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3870 "Switch TCP connection to SW TLS"); 3871 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3872 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3873 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3874 "Switch TCP connection to ifnet TLS"); 3875 #endif 3876 3877 /* 3878 * Generate a standardized TCP log line for use throughout the 3879 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3880 * allow use in the interrupt context. 3881 * 3882 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3883 * NB: The function may return NULL if memory allocation failed. 3884 * 3885 * Due to header inclusion and ordering limitations the struct ip 3886 * and ip6_hdr pointers have to be passed as void pointers. 3887 */ 3888 char * 3889 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3890 const void *ip6hdr) 3891 { 3892 3893 /* Is logging enabled? */ 3894 if (V_tcp_log_in_vain == 0) 3895 return (NULL); 3896 3897 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3898 } 3899 3900 char * 3901 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3902 const void *ip6hdr) 3903 { 3904 3905 /* Is logging enabled? */ 3906 if (tcp_log_debug == 0) 3907 return (NULL); 3908 3909 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3910 } 3911 3912 static char * 3913 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3914 const void *ip6hdr) 3915 { 3916 char *s, *sp; 3917 size_t size; 3918 struct ip *ip; 3919 #ifdef INET6 3920 const struct ip6_hdr *ip6; 3921 3922 ip6 = (const struct ip6_hdr *)ip6hdr; 3923 #endif /* INET6 */ 3924 ip = (struct ip *)ip4hdr; 3925 3926 /* 3927 * The log line looks like this: 3928 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3929 */ 3930 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3931 sizeof(PRINT_TH_FLAGS) + 1 + 3932 #ifdef INET6 3933 2 * INET6_ADDRSTRLEN; 3934 #else 3935 2 * INET_ADDRSTRLEN; 3936 #endif /* INET6 */ 3937 3938 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3939 if (s == NULL) 3940 return (NULL); 3941 3942 strcat(s, "TCP: ["); 3943 sp = s + strlen(s); 3944 3945 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3946 inet_ntoa_r(inc->inc_faddr, sp); 3947 sp = s + strlen(s); 3948 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3949 sp = s + strlen(s); 3950 inet_ntoa_r(inc->inc_laddr, sp); 3951 sp = s + strlen(s); 3952 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3953 #ifdef INET6 3954 } else if (inc) { 3955 ip6_sprintf(sp, &inc->inc6_faddr); 3956 sp = s + strlen(s); 3957 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3958 sp = s + strlen(s); 3959 ip6_sprintf(sp, &inc->inc6_laddr); 3960 sp = s + strlen(s); 3961 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3962 } else if (ip6 && th) { 3963 ip6_sprintf(sp, &ip6->ip6_src); 3964 sp = s + strlen(s); 3965 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3966 sp = s + strlen(s); 3967 ip6_sprintf(sp, &ip6->ip6_dst); 3968 sp = s + strlen(s); 3969 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3970 #endif /* INET6 */ 3971 #ifdef INET 3972 } else if (ip && th) { 3973 inet_ntoa_r(ip->ip_src, sp); 3974 sp = s + strlen(s); 3975 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3976 sp = s + strlen(s); 3977 inet_ntoa_r(ip->ip_dst, sp); 3978 sp = s + strlen(s); 3979 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3980 #endif /* INET */ 3981 } else { 3982 free(s, M_TCPLOG); 3983 return (NULL); 3984 } 3985 sp = s + strlen(s); 3986 if (th) 3987 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3988 if (*(s + size - 1) != '\0') 3989 panic("%s: string too long", __func__); 3990 return (s); 3991 } 3992 3993 /* 3994 * A subroutine which makes it easy to track TCP state changes with DTrace. 3995 * This function shouldn't be called for t_state initializations that don't 3996 * correspond to actual TCP state transitions. 3997 */ 3998 void 3999 tcp_state_change(struct tcpcb *tp, int newstate) 4000 { 4001 #if defined(KDTRACE_HOOKS) 4002 int pstate = tp->t_state; 4003 #endif 4004 4005 TCPSTATES_DEC(tp->t_state); 4006 TCPSTATES_INC(newstate); 4007 tp->t_state = newstate; 4008 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 4009 } 4010 4011 /* 4012 * Create an external-format (``xtcpcb'') structure using the information in 4013 * the kernel-format tcpcb structure pointed to by tp. This is done to 4014 * reduce the spew of irrelevant information over this interface, to isolate 4015 * user code from changes in the kernel structure, and potentially to provide 4016 * information-hiding if we decide that some of this information should be 4017 * hidden from users. 4018 */ 4019 void 4020 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 4021 { 4022 struct tcpcb *tp = intotcpcb(inp); 4023 struct tcptw *tw = intotw(inp); 4024 sbintime_t now; 4025 4026 bzero(xt, sizeof(*xt)); 4027 if (inp->inp_flags & INP_TIMEWAIT) { 4028 xt->t_state = TCPS_TIME_WAIT; 4029 xt->xt_encaps_port = tw->t_port; 4030 } else { 4031 xt->t_state = tp->t_state; 4032 xt->t_logstate = tp->t_logstate; 4033 xt->t_flags = tp->t_flags; 4034 xt->t_sndzerowin = tp->t_sndzerowin; 4035 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4036 xt->t_rcvoopack = tp->t_rcvoopack; 4037 xt->t_rcv_wnd = tp->rcv_wnd; 4038 xt->t_snd_wnd = tp->snd_wnd; 4039 xt->t_snd_cwnd = tp->snd_cwnd; 4040 xt->t_snd_ssthresh = tp->snd_ssthresh; 4041 xt->t_dsack_bytes = tp->t_dsack_bytes; 4042 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 4043 xt->t_dsack_pack = tp->t_dsack_pack; 4044 xt->t_maxseg = tp->t_maxseg; 4045 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4046 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4047 4048 now = getsbinuptime(); 4049 #define COPYTIMER(ttt) do { \ 4050 if (callout_active(&tp->t_timers->ttt)) \ 4051 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4052 SBT_1MS; \ 4053 else \ 4054 xt->ttt = 0; \ 4055 } while (0) 4056 COPYTIMER(tt_delack); 4057 COPYTIMER(tt_rexmt); 4058 COPYTIMER(tt_persist); 4059 COPYTIMER(tt_keep); 4060 COPYTIMER(tt_2msl); 4061 #undef COPYTIMER 4062 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4063 4064 xt->xt_encaps_port = tp->t_port; 4065 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4066 TCP_FUNCTION_NAME_LEN_MAX); 4067 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4068 TCP_CA_NAME_MAX); 4069 #ifdef TCP_BLACKBOX 4070 (void)tcp_log_get_id(tp, xt->xt_logid); 4071 #endif 4072 } 4073 4074 xt->xt_len = sizeof(struct xtcpcb); 4075 in_pcbtoxinpcb(inp, &xt->xt_inp); 4076 if (inp->inp_socket == NULL) 4077 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4078 } 4079 4080 void 4081 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4082 { 4083 uint32_t bit, i; 4084 4085 if ((tp == NULL) || 4086 (status > TCP_EI_STATUS_MAX_VALUE) || 4087 (status == 0)) { 4088 /* Invalid */ 4089 return; 4090 } 4091 if (status > (sizeof(uint32_t) * 8)) { 4092 /* Should this be a KASSERT? */ 4093 return; 4094 } 4095 bit = 1U << (status - 1); 4096 if (bit & tp->t_end_info_status) { 4097 /* already logged */ 4098 return; 4099 } 4100 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4101 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4102 tp->t_end_info_bytes[i] = status; 4103 tp->t_end_info_status |= bit; 4104 break; 4105 } 4106 } 4107 } 4108 4109 int 4110 tcp_can_enable_pacing(void) 4111 { 4112 4113 if ((tcp_pacing_limit == -1) || 4114 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4115 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4116 shadow_num_connections = number_of_tcp_connections_pacing; 4117 return (1); 4118 } else { 4119 return (0); 4120 } 4121 } 4122 4123 static uint8_t tcp_pacing_warning = 0; 4124 4125 void 4126 tcp_decrement_paced_conn(void) 4127 { 4128 uint32_t ret; 4129 4130 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4131 shadow_num_connections = number_of_tcp_connections_pacing; 4132 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4133 if (ret == 0) { 4134 if (tcp_pacing_limit != -1) { 4135 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4136 tcp_pacing_limit = 0; 4137 } else if (tcp_pacing_warning == 0) { 4138 printf("Warning pacing count is invalid, invalid decrement\n"); 4139 tcp_pacing_warning = 1; 4140 } 4141 } 4142 } 4143