1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/sdt.h> 68 #include <sys/socket.h> 69 #include <sys/socketvar.h> 70 #include <sys/protosw.h> 71 #include <sys/random.h> 72 73 #include <vm/uma.h> 74 75 #include <net/route.h> 76 #include <net/route/nhop.h> 77 #include <net/if.h> 78 #include <net/if_var.h> 79 #include <net/vnet.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_fib.h> 83 #include <netinet/in_kdtrace.h> 84 #include <netinet/in_pcb.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip.h> 88 #include <netinet/ip_icmp.h> 89 #include <netinet/ip_var.h> 90 #ifdef INET6 91 #include <netinet/icmp6.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/in6_fib.h> 94 #include <netinet6/in6_pcb.h> 95 #include <netinet6/ip6_var.h> 96 #include <netinet6/scope6_var.h> 97 #include <netinet6/nd6.h> 98 #endif 99 100 #include <netinet/tcp.h> 101 #ifdef INVARIANTS 102 #define TCPSTATES 103 #endif 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_log_buf.h> 109 #include <netinet/tcp_syncache.h> 110 #include <netinet/tcp_hpts.h> 111 #include <netinet/cc/cc.h> 112 #ifdef INET6 113 #include <netinet6/tcp6_var.h> 114 #endif 115 #include <netinet/tcpip.h> 116 #include <netinet/tcp_fastopen.h> 117 #ifdef TCPPCAP 118 #include <netinet/tcp_pcap.h> 119 #endif 120 #ifdef TCPDEBUG 121 #include <netinet/tcp_debug.h> 122 #endif 123 #ifdef INET6 124 #include <netinet6/ip6protosw.h> 125 #endif 126 #ifdef TCP_OFFLOAD 127 #include <netinet/tcp_offload.h> 128 #endif 129 #include <netinet/udp.h> 130 #include <netinet/udp_var.h> 131 132 #include <netipsec/ipsec_support.h> 133 134 #include <machine/in_cksum.h> 135 #include <crypto/siphash/siphash.h> 136 137 #include <security/mac/mac_framework.h> 138 139 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 140 #ifdef INET6 141 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 142 #endif 143 144 #ifdef NETFLIX_EXP_DETECTION 145 /* Sack attack detection thresholds and such */ 146 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 147 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 148 "Sack Attack detection thresholds"); 149 int32_t tcp_force_detection = 0; 150 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 151 CTLFLAG_RW, 152 &tcp_force_detection, 0, 153 "Do we force detection even if the INP has it off?"); 154 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 155 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 156 CTLFLAG_RW, 157 &tcp_sack_to_ack_thresh, 700, 158 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 159 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 160 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 161 CTLFLAG_RW, 162 &tcp_sack_to_move_thresh, 600, 163 "Percentage of sack moves we must see above (10.1 percent is 101)"); 164 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 165 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 166 CTLFLAG_RW, 167 &tcp_restoral_thresh, 550, 168 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 169 int32_t tcp_sad_decay_val = 800; 170 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 171 CTLFLAG_RW, 172 &tcp_sad_decay_val, 800, 173 "The decay percentage (10.1 percent equals 101 )"); 174 int32_t tcp_map_minimum = 500; 175 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 176 CTLFLAG_RW, 177 &tcp_map_minimum, 500, 178 "Number of Map enteries before we start detection"); 179 int32_t tcp_attack_on_turns_on_logging = 0; 180 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 181 CTLFLAG_RW, 182 &tcp_attack_on_turns_on_logging, 0, 183 "When we have a positive hit on attack, do we turn on logging?"); 184 int32_t tcp_sad_pacing_interval = 2000; 185 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 186 CTLFLAG_RW, 187 &tcp_sad_pacing_interval, 2000, 188 "What is the minimum pacing interval for a classified attacker?"); 189 190 int32_t tcp_sad_low_pps = 100; 191 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 192 CTLFLAG_RW, 193 &tcp_sad_low_pps, 100, 194 "What is the input pps that below which we do not decay?"); 195 #endif 196 uint32_t tcp_ack_war_time_window = 1000; 197 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 198 CTLFLAG_RW, 199 &tcp_ack_war_time_window, 1000, 200 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 201 uint32_t tcp_ack_war_cnt = 5; 202 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 203 CTLFLAG_RW, 204 &tcp_ack_war_cnt, 5, 205 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 206 207 struct rwlock tcp_function_lock; 208 209 static int 210 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 211 { 212 int error, new; 213 214 new = V_tcp_mssdflt; 215 error = sysctl_handle_int(oidp, &new, 0, req); 216 if (error == 0 && req->newptr) { 217 if (new < TCP_MINMSS) 218 error = EINVAL; 219 else 220 V_tcp_mssdflt = new; 221 } 222 return (error); 223 } 224 225 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 227 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 228 "Default TCP Maximum Segment Size"); 229 230 #ifdef INET6 231 static int 232 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 233 { 234 int error, new; 235 236 new = V_tcp_v6mssdflt; 237 error = sysctl_handle_int(oidp, &new, 0, req); 238 if (error == 0 && req->newptr) { 239 if (new < TCP_MINMSS) 240 error = EINVAL; 241 else 242 V_tcp_v6mssdflt = new; 243 } 244 return (error); 245 } 246 247 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 248 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 249 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 250 "Default TCP Maximum Segment Size for IPv6"); 251 #endif /* INET6 */ 252 253 /* 254 * Minimum MSS we accept and use. This prevents DoS attacks where 255 * we are forced to a ridiculous low MSS like 20 and send hundreds 256 * of packets instead of one. The effect scales with the available 257 * bandwidth and quickly saturates the CPU and network interface 258 * with packet generation and sending. Set to zero to disable MINMSS 259 * checking. This setting prevents us from sending too small packets. 260 */ 261 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 263 &VNET_NAME(tcp_minmss), 0, 264 "Minimum TCP Maximum Segment Size"); 265 266 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 267 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 268 &VNET_NAME(tcp_do_rfc1323), 0, 269 "Enable rfc1323 (high performance TCP) extensions"); 270 271 /* 272 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 273 * Some stacks negotiate TS, but never send them after connection setup. Some 274 * stacks negotiate TS, but don't send them when sending keep-alive segments. 275 * These include modern widely deployed TCP stacks. 276 * Therefore tolerating violations for now... 277 */ 278 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 280 &VNET_NAME(tcp_tolerate_missing_ts), 0, 281 "Tolerate missing TCP timestamps"); 282 283 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 284 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 285 &VNET_NAME(tcp_ts_offset_per_conn), 0, 286 "Initialize TCP timestamps per connection instead of per host pair"); 287 288 /* How many connections are pacing */ 289 static volatile uint32_t number_of_tcp_connections_pacing = 0; 290 static uint32_t shadow_num_connections = 0; 291 292 static int tcp_pacing_limit = 10000; 293 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 294 &tcp_pacing_limit, 1000, 295 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 296 297 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 298 &shadow_num_connections, 0, "Number of TCP connections being paced"); 299 300 static int tcp_log_debug = 0; 301 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 302 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 303 304 static int tcp_tcbhashsize; 305 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 306 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 307 308 static int do_tcpdrain = 1; 309 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 310 "Enable tcp_drain routine for extra help when low on mbufs"); 311 312 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 313 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 314 315 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 316 #define V_icmp_may_rst VNET(icmp_may_rst) 317 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 318 &VNET_NAME(icmp_may_rst), 0, 319 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 320 321 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 322 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 323 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 324 &VNET_NAME(tcp_isn_reseed_interval), 0, 325 "Seconds between reseeding of ISN secret"); 326 327 static int tcp_soreceive_stream; 328 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 329 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 330 331 VNET_DEFINE(uma_zone_t, sack_hole_zone); 332 #define V_sack_hole_zone VNET(sack_hole_zone) 333 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 334 static int 335 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 336 { 337 int error; 338 uint32_t new; 339 340 new = V_tcp_map_entries_limit; 341 error = sysctl_handle_int(oidp, &new, 0, req); 342 if (error == 0 && req->newptr) { 343 /* only allow "0" and value > minimum */ 344 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 345 error = EINVAL; 346 else 347 V_tcp_map_entries_limit = new; 348 } 349 return (error); 350 } 351 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 352 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 353 &VNET_NAME(tcp_map_entries_limit), 0, 354 &sysctl_net_inet_tcp_map_limit_check, "IU", 355 "Total sendmap entries limit"); 356 357 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 358 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 359 &VNET_NAME(tcp_map_split_limit), 0, 360 "Total sendmap split entries limit"); 361 362 #ifdef TCP_HHOOK 363 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 364 #endif 365 366 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 367 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 368 #define V_ts_offset_secret VNET(ts_offset_secret) 369 370 static int tcp_default_fb_init(struct tcpcb *tp); 371 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 372 static int tcp_default_handoff_ok(struct tcpcb *tp); 373 static struct inpcb *tcp_notify(struct inpcb *, int); 374 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 375 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 376 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 377 const void *ip4hdr, const void *ip6hdr); 378 379 static struct tcp_function_block tcp_def_funcblk = { 380 .tfb_tcp_block_name = "freebsd", 381 .tfb_tcp_output = tcp_default_output, 382 .tfb_tcp_do_segment = tcp_do_segment, 383 .tfb_tcp_ctloutput = tcp_default_ctloutput, 384 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 385 .tfb_tcp_fb_init = tcp_default_fb_init, 386 .tfb_tcp_fb_fini = tcp_default_fb_fini, 387 }; 388 389 static int tcp_fb_cnt = 0; 390 struct tcp_funchead t_functions; 391 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 392 393 void 394 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 395 { 396 TCPSTAT_INC(tcps_dsack_count); 397 tp->t_dsack_pack++; 398 if (tlp == 0) { 399 if (SEQ_GT(end, start)) { 400 tp->t_dsack_bytes += (end - start); 401 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 402 } else { 403 tp->t_dsack_tlp_bytes += (start - end); 404 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 405 } 406 } else { 407 if (SEQ_GT(end, start)) { 408 tp->t_dsack_bytes += (end - start); 409 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 410 } else { 411 tp->t_dsack_tlp_bytes += (start - end); 412 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 413 } 414 } 415 } 416 417 static struct tcp_function_block * 418 find_tcp_functions_locked(struct tcp_function_set *fs) 419 { 420 struct tcp_function *f; 421 struct tcp_function_block *blk=NULL; 422 423 TAILQ_FOREACH(f, &t_functions, tf_next) { 424 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 425 blk = f->tf_fb; 426 break; 427 } 428 } 429 return(blk); 430 } 431 432 static struct tcp_function_block * 433 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 434 { 435 struct tcp_function_block *rblk=NULL; 436 struct tcp_function *f; 437 438 TAILQ_FOREACH(f, &t_functions, tf_next) { 439 if (f->tf_fb == blk) { 440 rblk = blk; 441 if (s) { 442 *s = f; 443 } 444 break; 445 } 446 } 447 return (rblk); 448 } 449 450 struct tcp_function_block * 451 find_and_ref_tcp_functions(struct tcp_function_set *fs) 452 { 453 struct tcp_function_block *blk; 454 455 rw_rlock(&tcp_function_lock); 456 blk = find_tcp_functions_locked(fs); 457 if (blk) 458 refcount_acquire(&blk->tfb_refcnt); 459 rw_runlock(&tcp_function_lock); 460 return(blk); 461 } 462 463 struct tcp_function_block * 464 find_and_ref_tcp_fb(struct tcp_function_block *blk) 465 { 466 struct tcp_function_block *rblk; 467 468 rw_rlock(&tcp_function_lock); 469 rblk = find_tcp_fb_locked(blk, NULL); 470 if (rblk) 471 refcount_acquire(&rblk->tfb_refcnt); 472 rw_runlock(&tcp_function_lock); 473 return(rblk); 474 } 475 476 /* Find a matching alias for the given tcp_function_block. */ 477 int 478 find_tcp_function_alias(struct tcp_function_block *blk, 479 struct tcp_function_set *fs) 480 { 481 struct tcp_function *f; 482 int found; 483 484 found = 0; 485 rw_rlock(&tcp_function_lock); 486 TAILQ_FOREACH(f, &t_functions, tf_next) { 487 if ((f->tf_fb == blk) && 488 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 489 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 490 /* Matching function block with different name. */ 491 strncpy(fs->function_set_name, f->tf_name, 492 TCP_FUNCTION_NAME_LEN_MAX); 493 found = 1; 494 break; 495 } 496 } 497 /* Null terminate the string appropriately. */ 498 if (found) { 499 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 500 } else { 501 fs->function_set_name[0] = '\0'; 502 } 503 rw_runlock(&tcp_function_lock); 504 return (found); 505 } 506 507 static struct tcp_function_block * 508 find_and_ref_tcp_default_fb(void) 509 { 510 struct tcp_function_block *rblk; 511 512 rw_rlock(&tcp_function_lock); 513 rblk = tcp_func_set_ptr; 514 refcount_acquire(&rblk->tfb_refcnt); 515 rw_runlock(&tcp_function_lock); 516 return (rblk); 517 } 518 519 void 520 tcp_switch_back_to_default(struct tcpcb *tp) 521 { 522 struct tcp_function_block *tfb; 523 524 KASSERT(tp->t_fb != &tcp_def_funcblk, 525 ("%s: called by the built-in default stack", __func__)); 526 527 /* 528 * Release the old stack. This function will either find a new one 529 * or panic. 530 */ 531 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 532 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 533 refcount_release(&tp->t_fb->tfb_refcnt); 534 535 /* 536 * Now, we'll find a new function block to use. 537 * Start by trying the current user-selected 538 * default, unless this stack is the user-selected 539 * default. 540 */ 541 tfb = find_and_ref_tcp_default_fb(); 542 if (tfb == tp->t_fb) { 543 refcount_release(&tfb->tfb_refcnt); 544 tfb = NULL; 545 } 546 /* Does the stack accept this connection? */ 547 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 548 (*tfb->tfb_tcp_handoff_ok)(tp)) { 549 refcount_release(&tfb->tfb_refcnt); 550 tfb = NULL; 551 } 552 /* Try to use that stack. */ 553 if (tfb != NULL) { 554 /* Initialize the new stack. If it succeeds, we are done. */ 555 tp->t_fb = tfb; 556 if (tp->t_fb->tfb_tcp_fb_init == NULL || 557 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 558 return; 559 560 /* 561 * Initialization failed. Release the reference count on 562 * the stack. 563 */ 564 refcount_release(&tfb->tfb_refcnt); 565 } 566 567 /* 568 * If that wasn't feasible, use the built-in default 569 * stack which is not allowed to reject anyone. 570 */ 571 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 572 if (tfb == NULL) { 573 /* there always should be a default */ 574 panic("Can't refer to tcp_def_funcblk"); 575 } 576 if (tfb->tfb_tcp_handoff_ok != NULL) { 577 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 578 /* The default stack cannot say no */ 579 panic("Default stack rejects a new session?"); 580 } 581 } 582 tp->t_fb = tfb; 583 if (tp->t_fb->tfb_tcp_fb_init != NULL && 584 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 585 /* The default stack cannot fail */ 586 panic("Default stack initialization failed"); 587 } 588 } 589 590 static bool 591 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 592 const struct sockaddr *sa, void *ctx) 593 { 594 struct ip *iph; 595 #ifdef INET6 596 struct ip6_hdr *ip6; 597 #endif 598 struct udphdr *uh; 599 struct tcphdr *th; 600 int thlen; 601 uint16_t port; 602 603 TCPSTAT_INC(tcps_tunneled_pkts); 604 if ((m->m_flags & M_PKTHDR) == 0) { 605 /* Can't handle one that is not a pkt hdr */ 606 TCPSTAT_INC(tcps_tunneled_errs); 607 goto out; 608 } 609 thlen = sizeof(struct tcphdr); 610 if (m->m_len < off + sizeof(struct udphdr) + thlen && 611 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 612 TCPSTAT_INC(tcps_tunneled_errs); 613 goto out; 614 } 615 iph = mtod(m, struct ip *); 616 uh = (struct udphdr *)((caddr_t)iph + off); 617 th = (struct tcphdr *)(uh + 1); 618 thlen = th->th_off << 2; 619 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 620 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 621 if (m == NULL) { 622 TCPSTAT_INC(tcps_tunneled_errs); 623 goto out; 624 } else { 625 iph = mtod(m, struct ip *); 626 uh = (struct udphdr *)((caddr_t)iph + off); 627 th = (struct tcphdr *)(uh + 1); 628 } 629 } 630 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 631 bcopy(th, uh, m->m_len - off); 632 m->m_len -= sizeof(struct udphdr); 633 m->m_pkthdr.len -= sizeof(struct udphdr); 634 /* 635 * We use the same algorithm for 636 * both UDP and TCP for c-sum. So 637 * the code in tcp_input will skip 638 * the checksum. So we do nothing 639 * with the flag (m->m_pkthdr.csum_flags). 640 */ 641 switch (iph->ip_v) { 642 #ifdef INET 643 case IPVERSION: 644 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 645 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 646 break; 647 #endif 648 #ifdef INET6 649 case IPV6_VERSION >> 4: 650 ip6 = mtod(m, struct ip6_hdr *); 651 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 652 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 653 break; 654 #endif 655 default: 656 goto out; 657 break; 658 } 659 return (true); 660 out: 661 m_freem(m); 662 663 return (true); 664 } 665 666 static int 667 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 668 { 669 int error=ENOENT; 670 struct tcp_function_set fs; 671 struct tcp_function_block *blk; 672 673 memset(&fs, 0, sizeof(fs)); 674 rw_rlock(&tcp_function_lock); 675 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 676 if (blk) { 677 /* Found him */ 678 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 679 fs.pcbcnt = blk->tfb_refcnt; 680 } 681 rw_runlock(&tcp_function_lock); 682 error = sysctl_handle_string(oidp, fs.function_set_name, 683 sizeof(fs.function_set_name), req); 684 685 /* Check for error or no change */ 686 if (error != 0 || req->newptr == NULL) 687 return(error); 688 689 rw_wlock(&tcp_function_lock); 690 blk = find_tcp_functions_locked(&fs); 691 if ((blk == NULL) || 692 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 693 error = ENOENT; 694 goto done; 695 } 696 tcp_func_set_ptr = blk; 697 done: 698 rw_wunlock(&tcp_function_lock); 699 return (error); 700 } 701 702 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 703 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 704 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 705 "Set/get the default TCP functions"); 706 707 static int 708 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 709 { 710 int error, cnt, linesz; 711 struct tcp_function *f; 712 char *buffer, *cp; 713 size_t bufsz, outsz; 714 bool alias; 715 716 cnt = 0; 717 rw_rlock(&tcp_function_lock); 718 TAILQ_FOREACH(f, &t_functions, tf_next) { 719 cnt++; 720 } 721 rw_runlock(&tcp_function_lock); 722 723 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 724 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 725 726 error = 0; 727 cp = buffer; 728 729 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 730 "Alias", "PCB count"); 731 cp += linesz; 732 bufsz -= linesz; 733 outsz = linesz; 734 735 rw_rlock(&tcp_function_lock); 736 TAILQ_FOREACH(f, &t_functions, tf_next) { 737 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 738 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 739 f->tf_fb->tfb_tcp_block_name, 740 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 741 alias ? f->tf_name : "-", 742 f->tf_fb->tfb_refcnt); 743 if (linesz >= bufsz) { 744 error = EOVERFLOW; 745 break; 746 } 747 cp += linesz; 748 bufsz -= linesz; 749 outsz += linesz; 750 } 751 rw_runlock(&tcp_function_lock); 752 if (error == 0) 753 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 754 free(buffer, M_TEMP); 755 return (error); 756 } 757 758 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 759 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 760 NULL, 0, sysctl_net_inet_list_available, "A", 761 "list available TCP Function sets"); 762 763 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 764 765 #ifdef INET 766 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 767 #define V_udp4_tun_socket VNET(udp4_tun_socket) 768 #endif 769 #ifdef INET6 770 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 771 #define V_udp6_tun_socket VNET(udp6_tun_socket) 772 #endif 773 774 static void 775 tcp_over_udp_stop(void) 776 { 777 /* 778 * This function assumes sysctl caller holds inp_rinfo_lock() 779 * for writing! 780 */ 781 #ifdef INET 782 if (V_udp4_tun_socket != NULL) { 783 soclose(V_udp4_tun_socket); 784 V_udp4_tun_socket = NULL; 785 } 786 #endif 787 #ifdef INET6 788 if (V_udp6_tun_socket != NULL) { 789 soclose(V_udp6_tun_socket); 790 V_udp6_tun_socket = NULL; 791 } 792 #endif 793 } 794 795 static int 796 tcp_over_udp_start(void) 797 { 798 uint16_t port; 799 int ret; 800 #ifdef INET 801 struct sockaddr_in sin; 802 #endif 803 #ifdef INET6 804 struct sockaddr_in6 sin6; 805 #endif 806 /* 807 * This function assumes sysctl caller holds inp_info_rlock() 808 * for writing! 809 */ 810 port = V_tcp_udp_tunneling_port; 811 if (ntohs(port) == 0) { 812 /* Must have a port set */ 813 return (EINVAL); 814 } 815 #ifdef INET 816 if (V_udp4_tun_socket != NULL) { 817 /* Already running -- must stop first */ 818 return (EALREADY); 819 } 820 #endif 821 #ifdef INET6 822 if (V_udp6_tun_socket != NULL) { 823 /* Already running -- must stop first */ 824 return (EALREADY); 825 } 826 #endif 827 #ifdef INET 828 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 829 SOCK_DGRAM, IPPROTO_UDP, 830 curthread->td_ucred, curthread))) { 831 tcp_over_udp_stop(); 832 return (ret); 833 } 834 /* Call the special UDP hook. */ 835 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 836 tcp_recv_udp_tunneled_packet, 837 tcp_ctlinput_viaudp, 838 NULL))) { 839 tcp_over_udp_stop(); 840 return (ret); 841 } 842 /* Ok, we have a socket, bind it to the port. */ 843 memset(&sin, 0, sizeof(struct sockaddr_in)); 844 sin.sin_len = sizeof(struct sockaddr_in); 845 sin.sin_family = AF_INET; 846 sin.sin_port = htons(port); 847 if ((ret = sobind(V_udp4_tun_socket, 848 (struct sockaddr *)&sin, curthread))) { 849 tcp_over_udp_stop(); 850 return (ret); 851 } 852 #endif 853 #ifdef INET6 854 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 855 SOCK_DGRAM, IPPROTO_UDP, 856 curthread->td_ucred, curthread))) { 857 tcp_over_udp_stop(); 858 return (ret); 859 } 860 /* Call the special UDP hook. */ 861 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 862 tcp_recv_udp_tunneled_packet, 863 tcp6_ctlinput_viaudp, 864 NULL))) { 865 tcp_over_udp_stop(); 866 return (ret); 867 } 868 /* Ok, we have a socket, bind it to the port. */ 869 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 870 sin6.sin6_len = sizeof(struct sockaddr_in6); 871 sin6.sin6_family = AF_INET6; 872 sin6.sin6_port = htons(port); 873 if ((ret = sobind(V_udp6_tun_socket, 874 (struct sockaddr *)&sin6, curthread))) { 875 tcp_over_udp_stop(); 876 return (ret); 877 } 878 #endif 879 return (0); 880 } 881 882 static int 883 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 884 { 885 int error; 886 uint32_t old, new; 887 888 old = V_tcp_udp_tunneling_port; 889 new = old; 890 error = sysctl_handle_int(oidp, &new, 0, req); 891 if ((error == 0) && 892 (req->newptr != NULL)) { 893 if ((new < TCP_TUNNELING_PORT_MIN) || 894 (new > TCP_TUNNELING_PORT_MAX)) { 895 error = EINVAL; 896 } else { 897 V_tcp_udp_tunneling_port = new; 898 if (old != 0) { 899 tcp_over_udp_stop(); 900 } 901 if (new != 0) { 902 error = tcp_over_udp_start(); 903 } 904 } 905 } 906 return (error); 907 } 908 909 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 910 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 911 &VNET_NAME(tcp_udp_tunneling_port), 912 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 913 "Tunneling port for tcp over udp"); 914 915 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 916 917 static int 918 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 919 { 920 int error, new; 921 922 new = V_tcp_udp_tunneling_overhead; 923 error = sysctl_handle_int(oidp, &new, 0, req); 924 if (error == 0 && req->newptr) { 925 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 926 (new > TCP_TUNNELING_OVERHEAD_MAX)) 927 error = EINVAL; 928 else 929 V_tcp_udp_tunneling_overhead = new; 930 } 931 return (error); 932 } 933 934 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 935 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 936 &VNET_NAME(tcp_udp_tunneling_overhead), 937 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 938 "MSS reduction when using tcp over udp"); 939 940 /* 941 * Exports one (struct tcp_function_info) for each alias/name. 942 */ 943 static int 944 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 945 { 946 int cnt, error; 947 struct tcp_function *f; 948 struct tcp_function_info tfi; 949 950 /* 951 * We don't allow writes. 952 */ 953 if (req->newptr != NULL) 954 return (EINVAL); 955 956 /* 957 * Wire the old buffer so we can directly copy the functions to 958 * user space without dropping the lock. 959 */ 960 if (req->oldptr != NULL) { 961 error = sysctl_wire_old_buffer(req, 0); 962 if (error) 963 return (error); 964 } 965 966 /* 967 * Walk the list and copy out matching entries. If INVARIANTS 968 * is compiled in, also walk the list to verify the length of 969 * the list matches what we have recorded. 970 */ 971 rw_rlock(&tcp_function_lock); 972 973 cnt = 0; 974 #ifndef INVARIANTS 975 if (req->oldptr == NULL) { 976 cnt = tcp_fb_cnt; 977 goto skip_loop; 978 } 979 #endif 980 TAILQ_FOREACH(f, &t_functions, tf_next) { 981 #ifdef INVARIANTS 982 cnt++; 983 #endif 984 if (req->oldptr != NULL) { 985 bzero(&tfi, sizeof(tfi)); 986 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 987 tfi.tfi_id = f->tf_fb->tfb_id; 988 (void)strlcpy(tfi.tfi_alias, f->tf_name, 989 sizeof(tfi.tfi_alias)); 990 (void)strlcpy(tfi.tfi_name, 991 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 992 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 993 /* 994 * Don't stop on error, as that is the 995 * mechanism we use to accumulate length 996 * information if the buffer was too short. 997 */ 998 } 999 } 1000 KASSERT(cnt == tcp_fb_cnt, 1001 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1002 #ifndef INVARIANTS 1003 skip_loop: 1004 #endif 1005 rw_runlock(&tcp_function_lock); 1006 if (req->oldptr == NULL) 1007 error = SYSCTL_OUT(req, NULL, 1008 (cnt + 1) * sizeof(struct tcp_function_info)); 1009 1010 return (error); 1011 } 1012 1013 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1014 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1015 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1016 "List TCP function block name-to-ID mappings"); 1017 1018 /* 1019 * tfb_tcp_handoff_ok() function for the default stack. 1020 * Note that we'll basically try to take all comers. 1021 */ 1022 static int 1023 tcp_default_handoff_ok(struct tcpcb *tp) 1024 { 1025 1026 return (0); 1027 } 1028 1029 /* 1030 * tfb_tcp_fb_init() function for the default stack. 1031 * 1032 * This handles making sure we have appropriate timers set if you are 1033 * transitioning a socket that has some amount of setup done. 1034 * 1035 * The init() fuction from the default can *never* return non-zero i.e. 1036 * it is required to always succeed since it is the stack of last resort! 1037 */ 1038 static int 1039 tcp_default_fb_init(struct tcpcb *tp) 1040 { 1041 1042 struct socket *so; 1043 1044 INP_WLOCK_ASSERT(tp->t_inpcb); 1045 1046 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1047 ("%s: connection %p in unexpected state %d", __func__, tp, 1048 tp->t_state)); 1049 1050 /* 1051 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1052 * know what to do for unexpected states (which includes TIME_WAIT). 1053 */ 1054 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1055 return (0); 1056 1057 /* 1058 * Make sure some kind of transmission timer is set if there is 1059 * outstanding data. 1060 */ 1061 so = tp->t_inpcb->inp_socket; 1062 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1063 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1064 tcp_timer_active(tp, TT_PERSIST))) { 1065 /* 1066 * If the session has established and it looks like it should 1067 * be in the persist state, set the persist timer. Otherwise, 1068 * set the retransmit timer. 1069 */ 1070 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1071 (int32_t)(tp->snd_nxt - tp->snd_una) < 1072 (int32_t)sbavail(&so->so_snd)) 1073 tcp_setpersist(tp); 1074 else 1075 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1076 } 1077 1078 /* All non-embryonic sessions get a keepalive timer. */ 1079 if (!tcp_timer_active(tp, TT_KEEP)) 1080 tcp_timer_activate(tp, TT_KEEP, 1081 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1082 TP_KEEPINIT(tp)); 1083 1084 /* 1085 * Make sure critical variables are initialized 1086 * if transitioning while in Recovery. 1087 */ 1088 if IN_FASTRECOVERY(tp->t_flags) { 1089 if (tp->sackhint.recover_fs == 0) 1090 tp->sackhint.recover_fs = max(1, 1091 tp->snd_nxt - tp->snd_una); 1092 } 1093 1094 return (0); 1095 } 1096 1097 /* 1098 * tfb_tcp_fb_fini() function for the default stack. 1099 * 1100 * This changes state as necessary (or prudent) to prepare for another stack 1101 * to assume responsibility for the connection. 1102 */ 1103 static void 1104 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1105 { 1106 1107 INP_WLOCK_ASSERT(tp->t_inpcb); 1108 return; 1109 } 1110 1111 /* 1112 * Target size of TCP PCB hash tables. Must be a power of two. 1113 * 1114 * Note that this can be overridden by the kernel environment 1115 * variable net.inet.tcp.tcbhashsize 1116 */ 1117 #ifndef TCBHASHSIZE 1118 #define TCBHASHSIZE 0 1119 #endif 1120 1121 /* 1122 * XXX 1123 * Callouts should be moved into struct tcp directly. They are currently 1124 * separate because the tcpcb structure is exported to userland for sysctl 1125 * parsing purposes, which do not know about callouts. 1126 */ 1127 struct tcpcb_mem { 1128 struct tcpcb tcb; 1129 struct tcp_timer tt; 1130 struct cc_var ccv; 1131 #ifdef TCP_HHOOK 1132 struct osd osd; 1133 #endif 1134 }; 1135 1136 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1137 #define V_tcpcb_zone VNET(tcpcb_zone) 1138 1139 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1140 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1141 1142 static struct mtx isn_mtx; 1143 1144 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1145 #define ISN_LOCK() mtx_lock(&isn_mtx) 1146 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1147 1148 INPCBSTORAGE_DEFINE(tcpcbstor, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1149 1150 /* 1151 * Take a value and get the next power of 2 that doesn't overflow. 1152 * Used to size the tcp_inpcb hash buckets. 1153 */ 1154 static int 1155 maketcp_hashsize(int size) 1156 { 1157 int hashsize; 1158 1159 /* 1160 * auto tune. 1161 * get the next power of 2 higher than maxsockets. 1162 */ 1163 hashsize = 1 << fls(size); 1164 /* catch overflow, and just go one power of 2 smaller */ 1165 if (hashsize < size) { 1166 hashsize = 1 << (fls(size) - 1); 1167 } 1168 return (hashsize); 1169 } 1170 1171 static volatile int next_tcp_stack_id = 1; 1172 1173 /* 1174 * Register a TCP function block with the name provided in the names 1175 * array. (Note that this function does NOT automatically register 1176 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1177 * explicitly include blk->tfb_tcp_block_name in the list of names if 1178 * you wish to register the stack with that name.) 1179 * 1180 * Either all name registrations will succeed or all will fail. If 1181 * a name registration fails, the function will update the num_names 1182 * argument to point to the array index of the name that encountered 1183 * the failure. 1184 * 1185 * Returns 0 on success, or an error code on failure. 1186 */ 1187 int 1188 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1189 const char *names[], int *num_names) 1190 { 1191 struct tcp_function *n; 1192 struct tcp_function_set fs; 1193 int error, i; 1194 1195 KASSERT(names != NULL && *num_names > 0, 1196 ("%s: Called with 0-length name list", __func__)); 1197 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1198 KASSERT(rw_initialized(&tcp_function_lock), 1199 ("%s: called too early", __func__)); 1200 1201 if ((blk->tfb_tcp_output == NULL) || 1202 (blk->tfb_tcp_do_segment == NULL) || 1203 (blk->tfb_tcp_ctloutput == NULL) || 1204 (strlen(blk->tfb_tcp_block_name) == 0)) { 1205 /* 1206 * These functions are required and you 1207 * need a name. 1208 */ 1209 *num_names = 0; 1210 return (EINVAL); 1211 } 1212 if (blk->tfb_tcp_timer_stop_all || 1213 blk->tfb_tcp_timer_activate || 1214 blk->tfb_tcp_timer_active || 1215 blk->tfb_tcp_timer_stop) { 1216 /* 1217 * If you define one timer function you 1218 * must have them all. 1219 */ 1220 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1221 (blk->tfb_tcp_timer_activate == NULL) || 1222 (blk->tfb_tcp_timer_active == NULL) || 1223 (blk->tfb_tcp_timer_stop == NULL)) { 1224 *num_names = 0; 1225 return (EINVAL); 1226 } 1227 } 1228 1229 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1230 *num_names = 0; 1231 return (EINVAL); 1232 } 1233 1234 refcount_init(&blk->tfb_refcnt, 0); 1235 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1236 for (i = 0; i < *num_names; i++) { 1237 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1238 if (n == NULL) { 1239 error = ENOMEM; 1240 goto cleanup; 1241 } 1242 n->tf_fb = blk; 1243 1244 (void)strlcpy(fs.function_set_name, names[i], 1245 sizeof(fs.function_set_name)); 1246 rw_wlock(&tcp_function_lock); 1247 if (find_tcp_functions_locked(&fs) != NULL) { 1248 /* Duplicate name space not allowed */ 1249 rw_wunlock(&tcp_function_lock); 1250 free(n, M_TCPFUNCTIONS); 1251 error = EALREADY; 1252 goto cleanup; 1253 } 1254 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1255 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1256 tcp_fb_cnt++; 1257 rw_wunlock(&tcp_function_lock); 1258 } 1259 return(0); 1260 1261 cleanup: 1262 /* 1263 * Deregister the names we just added. Because registration failed 1264 * for names[i], we don't need to deregister that name. 1265 */ 1266 *num_names = i; 1267 rw_wlock(&tcp_function_lock); 1268 while (--i >= 0) { 1269 TAILQ_FOREACH(n, &t_functions, tf_next) { 1270 if (!strncmp(n->tf_name, names[i], 1271 TCP_FUNCTION_NAME_LEN_MAX)) { 1272 TAILQ_REMOVE(&t_functions, n, tf_next); 1273 tcp_fb_cnt--; 1274 n->tf_fb = NULL; 1275 free(n, M_TCPFUNCTIONS); 1276 break; 1277 } 1278 } 1279 } 1280 rw_wunlock(&tcp_function_lock); 1281 return (error); 1282 } 1283 1284 /* 1285 * Register a TCP function block using the name provided in the name 1286 * argument. 1287 * 1288 * Returns 0 on success, or an error code on failure. 1289 */ 1290 int 1291 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1292 int wait) 1293 { 1294 const char *name_list[1]; 1295 int num_names, rv; 1296 1297 num_names = 1; 1298 if (name != NULL) 1299 name_list[0] = name; 1300 else 1301 name_list[0] = blk->tfb_tcp_block_name; 1302 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1303 return (rv); 1304 } 1305 1306 /* 1307 * Register a TCP function block using the name defined in 1308 * blk->tfb_tcp_block_name. 1309 * 1310 * Returns 0 on success, or an error code on failure. 1311 */ 1312 int 1313 register_tcp_functions(struct tcp_function_block *blk, int wait) 1314 { 1315 1316 return (register_tcp_functions_as_name(blk, NULL, wait)); 1317 } 1318 1319 /* 1320 * Deregister all names associated with a function block. This 1321 * functionally removes the function block from use within the system. 1322 * 1323 * When called with a true quiesce argument, mark the function block 1324 * as being removed so no more stacks will use it and determine 1325 * whether the removal would succeed. 1326 * 1327 * When called with a false quiesce argument, actually attempt the 1328 * removal. 1329 * 1330 * When called with a force argument, attempt to switch all TCBs to 1331 * use the default stack instead of returning EBUSY. 1332 * 1333 * Returns 0 on success (or if the removal would succeed, or an error 1334 * code on failure. 1335 */ 1336 int 1337 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1338 bool force) 1339 { 1340 struct tcp_function *f; 1341 1342 if (blk == &tcp_def_funcblk) { 1343 /* You can't un-register the default */ 1344 return (EPERM); 1345 } 1346 rw_wlock(&tcp_function_lock); 1347 if (blk == tcp_func_set_ptr) { 1348 /* You can't free the current default */ 1349 rw_wunlock(&tcp_function_lock); 1350 return (EBUSY); 1351 } 1352 /* Mark the block so no more stacks can use it. */ 1353 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1354 /* 1355 * If TCBs are still attached to the stack, attempt to switch them 1356 * to the default stack. 1357 */ 1358 if (force && blk->tfb_refcnt) { 1359 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1360 INPLOOKUP_WLOCKPCB); 1361 struct inpcb *inp; 1362 struct tcpcb *tp; 1363 VNET_ITERATOR_DECL(vnet_iter); 1364 1365 rw_wunlock(&tcp_function_lock); 1366 1367 VNET_LIST_RLOCK(); 1368 VNET_FOREACH(vnet_iter) { 1369 CURVNET_SET(vnet_iter); 1370 while ((inp = inp_next(&inpi)) != NULL) { 1371 if (inp->inp_flags & INP_TIMEWAIT) 1372 continue; 1373 tp = intotcpcb(inp); 1374 if (tp == NULL || tp->t_fb != blk) 1375 continue; 1376 tcp_switch_back_to_default(tp); 1377 } 1378 CURVNET_RESTORE(); 1379 } 1380 VNET_LIST_RUNLOCK(); 1381 1382 rw_wlock(&tcp_function_lock); 1383 } 1384 if (blk->tfb_refcnt) { 1385 /* TCBs still attached. */ 1386 rw_wunlock(&tcp_function_lock); 1387 return (EBUSY); 1388 } 1389 if (quiesce) { 1390 /* Skip removal. */ 1391 rw_wunlock(&tcp_function_lock); 1392 return (0); 1393 } 1394 /* Remove any function names that map to this function block. */ 1395 while (find_tcp_fb_locked(blk, &f) != NULL) { 1396 TAILQ_REMOVE(&t_functions, f, tf_next); 1397 tcp_fb_cnt--; 1398 f->tf_fb = NULL; 1399 free(f, M_TCPFUNCTIONS); 1400 } 1401 rw_wunlock(&tcp_function_lock); 1402 return (0); 1403 } 1404 1405 static void 1406 tcp_drain(void) 1407 { 1408 struct epoch_tracker et; 1409 VNET_ITERATOR_DECL(vnet_iter); 1410 1411 if (!do_tcpdrain) 1412 return; 1413 1414 NET_EPOCH_ENTER(et); 1415 VNET_LIST_RLOCK_NOSLEEP(); 1416 VNET_FOREACH(vnet_iter) { 1417 CURVNET_SET(vnet_iter); 1418 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1419 INPLOOKUP_WLOCKPCB); 1420 struct inpcb *inpb; 1421 struct tcpcb *tcpb; 1422 1423 /* 1424 * Walk the tcpbs, if existing, and flush the reassembly queue, 1425 * if there is one... 1426 * XXX: The "Net/3" implementation doesn't imply that the TCP 1427 * reassembly queue should be flushed, but in a situation 1428 * where we're really low on mbufs, this is potentially 1429 * useful. 1430 */ 1431 while ((inpb = inp_next(&inpi)) != NULL) { 1432 if (inpb->inp_flags & INP_TIMEWAIT) 1433 continue; 1434 if ((tcpb = intotcpcb(inpb)) != NULL) { 1435 tcp_reass_flush(tcpb); 1436 tcp_clean_sackreport(tcpb); 1437 #ifdef TCP_BLACKBOX 1438 tcp_log_drain(tcpb); 1439 #endif 1440 #ifdef TCPPCAP 1441 if (tcp_pcap_aggressive_free) { 1442 /* Free the TCP PCAP queues. */ 1443 tcp_pcap_drain(&(tcpb->t_inpkts)); 1444 tcp_pcap_drain(&(tcpb->t_outpkts)); 1445 } 1446 #endif 1447 } 1448 } 1449 CURVNET_RESTORE(); 1450 } 1451 VNET_LIST_RUNLOCK_NOSLEEP(); 1452 NET_EPOCH_EXIT(et); 1453 } 1454 1455 static void 1456 tcp_vnet_init(void *arg __unused) 1457 { 1458 1459 #ifdef TCP_HHOOK 1460 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1461 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1462 printf("%s: WARNING: unable to register helper hook\n", __func__); 1463 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1464 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1465 printf("%s: WARNING: unable to register helper hook\n", __func__); 1466 #endif 1467 #ifdef STATS 1468 if (tcp_stats_init()) 1469 printf("%s: WARNING: unable to initialise TCP stats\n", 1470 __func__); 1471 #endif 1472 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1473 tcp_tcbhashsize); 1474 1475 /* 1476 * These have to be type stable for the benefit of the timers. 1477 */ 1478 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1479 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1480 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1481 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1482 1483 tcp_tw_init(); 1484 syncache_init(); 1485 tcp_hc_init(); 1486 1487 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1488 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1489 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1490 1491 tcp_fastopen_init(); 1492 1493 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1494 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1495 1496 V_tcp_msl = TCPTV_MSL; 1497 } 1498 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1499 tcp_vnet_init, NULL); 1500 1501 static void 1502 tcp_init(void *arg __unused) 1503 { 1504 const char *tcbhash_tuneable; 1505 int hashsize; 1506 1507 tcp_reass_global_init(); 1508 1509 /* XXX virtualize those below? */ 1510 tcp_delacktime = TCPTV_DELACK; 1511 tcp_keepinit = TCPTV_KEEP_INIT; 1512 tcp_keepidle = TCPTV_KEEP_IDLE; 1513 tcp_keepintvl = TCPTV_KEEPINTVL; 1514 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1515 tcp_rexmit_initial = TCPTV_RTOBASE; 1516 if (tcp_rexmit_initial < 1) 1517 tcp_rexmit_initial = 1; 1518 tcp_rexmit_min = TCPTV_MIN; 1519 if (tcp_rexmit_min < 1) 1520 tcp_rexmit_min = 1; 1521 tcp_persmin = TCPTV_PERSMIN; 1522 tcp_persmax = TCPTV_PERSMAX; 1523 tcp_rexmit_slop = TCPTV_CPU_VAR; 1524 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1525 1526 /* Setup the tcp function block list */ 1527 TAILQ_INIT(&t_functions); 1528 rw_init(&tcp_function_lock, "tcp_func_lock"); 1529 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1530 #ifdef TCP_BLACKBOX 1531 /* Initialize the TCP logging data. */ 1532 tcp_log_init(); 1533 #endif 1534 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1535 1536 if (tcp_soreceive_stream) { 1537 #ifdef INET 1538 tcp_protosw.pr_soreceive = soreceive_stream; 1539 #endif 1540 #ifdef INET6 1541 tcp6_protosw.pr_soreceive = soreceive_stream; 1542 #endif /* INET6 */ 1543 } 1544 1545 #ifdef INET6 1546 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1547 #else /* INET6 */ 1548 max_protohdr_grow(sizeof(struct tcpiphdr)); 1549 #endif /* INET6 */ 1550 1551 ISN_LOCK_INIT(); 1552 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1553 SHUTDOWN_PRI_DEFAULT); 1554 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1555 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1556 1557 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1558 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1559 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1560 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1561 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1562 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1563 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1564 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1565 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1566 #ifdef TCPPCAP 1567 tcp_pcap_init(); 1568 #endif 1569 1570 hashsize = TCBHASHSIZE; 1571 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1572 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1573 if (hashsize == 0) { 1574 /* 1575 * Auto tune the hash size based on maxsockets. 1576 * A perfect hash would have a 1:1 mapping 1577 * (hashsize = maxsockets) however it's been 1578 * suggested that O(2) average is better. 1579 */ 1580 hashsize = maketcp_hashsize(maxsockets / 4); 1581 /* 1582 * Our historical default is 512, 1583 * do not autotune lower than this. 1584 */ 1585 if (hashsize < 512) 1586 hashsize = 512; 1587 if (bootverbose) 1588 printf("%s: %s auto tuned to %d\n", __func__, 1589 tcbhash_tuneable, hashsize); 1590 } 1591 /* 1592 * We require a hashsize to be a power of two. 1593 * Previously if it was not a power of two we would just reset it 1594 * back to 512, which could be a nasty surprise if you did not notice 1595 * the error message. 1596 * Instead what we do is clip it to the closest power of two lower 1597 * than the specified hash value. 1598 */ 1599 if (!powerof2(hashsize)) { 1600 int oldhashsize = hashsize; 1601 1602 hashsize = maketcp_hashsize(hashsize); 1603 /* prevent absurdly low value */ 1604 if (hashsize < 16) 1605 hashsize = 16; 1606 printf("%s: WARNING: TCB hash size not a power of 2, " 1607 "clipped from %d to %d.\n", __func__, oldhashsize, 1608 hashsize); 1609 } 1610 tcp_tcbhashsize = hashsize; 1611 1612 #ifdef INET 1613 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1614 #endif 1615 #ifdef INET6 1616 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1617 #endif 1618 } 1619 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1620 1621 #ifdef VIMAGE 1622 static void 1623 tcp_destroy(void *unused __unused) 1624 { 1625 int n; 1626 #ifdef TCP_HHOOK 1627 int error; 1628 #endif 1629 1630 /* 1631 * All our processes are gone, all our sockets should be cleaned 1632 * up, which means, we should be past the tcp_discardcb() calls. 1633 * Sleep to let all tcpcb timers really disappear and cleanup. 1634 */ 1635 for (;;) { 1636 INP_INFO_WLOCK(&V_tcbinfo); 1637 n = V_tcbinfo.ipi_count; 1638 INP_INFO_WUNLOCK(&V_tcbinfo); 1639 if (n == 0) 1640 break; 1641 pause("tcpdes", hz / 10); 1642 } 1643 tcp_hc_destroy(); 1644 syncache_destroy(); 1645 tcp_tw_destroy(); 1646 in_pcbinfo_destroy(&V_tcbinfo); 1647 /* tcp_discardcb() clears the sack_holes up. */ 1648 uma_zdestroy(V_sack_hole_zone); 1649 uma_zdestroy(V_tcpcb_zone); 1650 1651 /* 1652 * Cannot free the zone until all tcpcbs are released as we attach 1653 * the allocations to them. 1654 */ 1655 tcp_fastopen_destroy(); 1656 1657 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1658 VNET_PCPUSTAT_FREE(tcpstat); 1659 1660 #ifdef TCP_HHOOK 1661 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1662 if (error != 0) { 1663 printf("%s: WARNING: unable to deregister helper hook " 1664 "type=%d, id=%d: error %d returned\n", __func__, 1665 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1666 } 1667 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1668 if (error != 0) { 1669 printf("%s: WARNING: unable to deregister helper hook " 1670 "type=%d, id=%d: error %d returned\n", __func__, 1671 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1672 } 1673 #endif 1674 } 1675 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1676 #endif 1677 1678 void 1679 tcp_fini(void *xtp) 1680 { 1681 1682 } 1683 1684 /* 1685 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1686 * tcp_template used to store this data in mbufs, but we now recopy it out 1687 * of the tcpcb each time to conserve mbufs. 1688 */ 1689 void 1690 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1691 { 1692 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1693 1694 INP_WLOCK_ASSERT(inp); 1695 1696 #ifdef INET6 1697 if ((inp->inp_vflag & INP_IPV6) != 0) { 1698 struct ip6_hdr *ip6; 1699 1700 ip6 = (struct ip6_hdr *)ip_ptr; 1701 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1702 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1703 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1704 (IPV6_VERSION & IPV6_VERSION_MASK); 1705 if (port == 0) 1706 ip6->ip6_nxt = IPPROTO_TCP; 1707 else 1708 ip6->ip6_nxt = IPPROTO_UDP; 1709 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1710 ip6->ip6_src = inp->in6p_laddr; 1711 ip6->ip6_dst = inp->in6p_faddr; 1712 } 1713 #endif /* INET6 */ 1714 #if defined(INET6) && defined(INET) 1715 else 1716 #endif 1717 #ifdef INET 1718 { 1719 struct ip *ip; 1720 1721 ip = (struct ip *)ip_ptr; 1722 ip->ip_v = IPVERSION; 1723 ip->ip_hl = 5; 1724 ip->ip_tos = inp->inp_ip_tos; 1725 ip->ip_len = 0; 1726 ip->ip_id = 0; 1727 ip->ip_off = 0; 1728 ip->ip_ttl = inp->inp_ip_ttl; 1729 ip->ip_sum = 0; 1730 if (port == 0) 1731 ip->ip_p = IPPROTO_TCP; 1732 else 1733 ip->ip_p = IPPROTO_UDP; 1734 ip->ip_src = inp->inp_laddr; 1735 ip->ip_dst = inp->inp_faddr; 1736 } 1737 #endif /* INET */ 1738 th->th_sport = inp->inp_lport; 1739 th->th_dport = inp->inp_fport; 1740 th->th_seq = 0; 1741 th->th_ack = 0; 1742 th->th_off = 5; 1743 tcp_set_flags(th, 0); 1744 th->th_win = 0; 1745 th->th_urp = 0; 1746 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1747 } 1748 1749 /* 1750 * Create template to be used to send tcp packets on a connection. 1751 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1752 * use for this function is in keepalives, which use tcp_respond. 1753 */ 1754 struct tcptemp * 1755 tcpip_maketemplate(struct inpcb *inp) 1756 { 1757 struct tcptemp *t; 1758 1759 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1760 if (t == NULL) 1761 return (NULL); 1762 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1763 return (t); 1764 } 1765 1766 /* 1767 * Send a single message to the TCP at address specified by 1768 * the given TCP/IP header. If m == NULL, then we make a copy 1769 * of the tcpiphdr at th and send directly to the addressed host. 1770 * This is used to force keep alive messages out using the TCP 1771 * template for a connection. If flags are given then we send 1772 * a message back to the TCP which originated the segment th, 1773 * and discard the mbuf containing it and any other attached mbufs. 1774 * 1775 * In any case the ack and sequence number of the transmitted 1776 * segment are as specified by the parameters. 1777 * 1778 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1779 */ 1780 void 1781 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1782 tcp_seq ack, tcp_seq seq, int flags) 1783 { 1784 struct tcpopt to; 1785 struct inpcb *inp; 1786 struct ip *ip; 1787 struct mbuf *optm; 1788 struct udphdr *uh = NULL; 1789 struct tcphdr *nth; 1790 struct tcp_log_buffer *lgb; 1791 u_char *optp; 1792 #ifdef INET6 1793 struct ip6_hdr *ip6; 1794 int isipv6; 1795 #endif /* INET6 */ 1796 int optlen, tlen, win, ulen; 1797 bool incl_opts; 1798 uint16_t port; 1799 int output_ret; 1800 #ifdef INVARIANTS 1801 int thflags = tcp_get_flags(th); 1802 #endif 1803 1804 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1805 NET_EPOCH_ASSERT(); 1806 1807 #ifdef INET6 1808 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1809 ip6 = ipgen; 1810 #endif /* INET6 */ 1811 ip = ipgen; 1812 1813 if (tp != NULL) { 1814 inp = tp->t_inpcb; 1815 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1816 INP_LOCK_ASSERT(inp); 1817 } else 1818 inp = NULL; 1819 1820 if (m != NULL) { 1821 #ifdef INET6 1822 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1823 port = m->m_pkthdr.tcp_tun_port; 1824 else 1825 #endif 1826 if (ip && (ip->ip_p == IPPROTO_UDP)) 1827 port = m->m_pkthdr.tcp_tun_port; 1828 else 1829 port = 0; 1830 } else 1831 port = tp->t_port; 1832 1833 incl_opts = false; 1834 win = 0; 1835 if (tp != NULL) { 1836 if (!(flags & TH_RST)) { 1837 win = sbspace(&inp->inp_socket->so_rcv); 1838 if (win > TCP_MAXWIN << tp->rcv_scale) 1839 win = TCP_MAXWIN << tp->rcv_scale; 1840 } 1841 if ((tp->t_flags & TF_NOOPT) == 0) 1842 incl_opts = true; 1843 } 1844 if (m == NULL) { 1845 m = m_gethdr(M_NOWAIT, MT_DATA); 1846 if (m == NULL) 1847 return; 1848 m->m_data += max_linkhdr; 1849 #ifdef INET6 1850 if (isipv6) { 1851 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1852 sizeof(struct ip6_hdr)); 1853 ip6 = mtod(m, struct ip6_hdr *); 1854 nth = (struct tcphdr *)(ip6 + 1); 1855 if (port) { 1856 /* Insert a UDP header */ 1857 uh = (struct udphdr *)nth; 1858 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1859 uh->uh_dport = port; 1860 nth = (struct tcphdr *)(uh + 1); 1861 } 1862 } else 1863 #endif /* INET6 */ 1864 { 1865 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1866 ip = mtod(m, struct ip *); 1867 nth = (struct tcphdr *)(ip + 1); 1868 if (port) { 1869 /* Insert a UDP header */ 1870 uh = (struct udphdr *)nth; 1871 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1872 uh->uh_dport = port; 1873 nth = (struct tcphdr *)(uh + 1); 1874 } 1875 } 1876 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1877 flags = TH_ACK; 1878 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1879 struct mbuf *n; 1880 1881 /* Can't reuse 'm', allocate a new mbuf. */ 1882 n = m_gethdr(M_NOWAIT, MT_DATA); 1883 if (n == NULL) { 1884 m_freem(m); 1885 return; 1886 } 1887 1888 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1889 m_freem(m); 1890 m_freem(n); 1891 return; 1892 } 1893 1894 n->m_data += max_linkhdr; 1895 /* m_len is set later */ 1896 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1897 #ifdef INET6 1898 if (isipv6) { 1899 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1900 sizeof(struct ip6_hdr)); 1901 ip6 = mtod(n, struct ip6_hdr *); 1902 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1903 nth = (struct tcphdr *)(ip6 + 1); 1904 if (port) { 1905 /* Insert a UDP header */ 1906 uh = (struct udphdr *)nth; 1907 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1908 uh->uh_dport = port; 1909 nth = (struct tcphdr *)(uh + 1); 1910 } 1911 } else 1912 #endif /* INET6 */ 1913 { 1914 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1915 ip = mtod(n, struct ip *); 1916 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1917 nth = (struct tcphdr *)(ip + 1); 1918 if (port) { 1919 /* Insert a UDP header */ 1920 uh = (struct udphdr *)nth; 1921 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1922 uh->uh_dport = port; 1923 nth = (struct tcphdr *)(uh + 1); 1924 } 1925 } 1926 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1927 xchg(nth->th_dport, nth->th_sport, uint16_t); 1928 th = nth; 1929 m_freem(m); 1930 m = n; 1931 } else { 1932 /* 1933 * reuse the mbuf. 1934 * XXX MRT We inherit the FIB, which is lucky. 1935 */ 1936 m_freem(m->m_next); 1937 m->m_next = NULL; 1938 m->m_data = (caddr_t)ipgen; 1939 /* m_len is set later */ 1940 #ifdef INET6 1941 if (isipv6) { 1942 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1943 nth = (struct tcphdr *)(ip6 + 1); 1944 } else 1945 #endif /* INET6 */ 1946 { 1947 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1948 nth = (struct tcphdr *)(ip + 1); 1949 } 1950 if (th != nth) { 1951 /* 1952 * this is usually a case when an extension header 1953 * exists between the IPv6 header and the 1954 * TCP header. 1955 */ 1956 nth->th_sport = th->th_sport; 1957 nth->th_dport = th->th_dport; 1958 } 1959 xchg(nth->th_dport, nth->th_sport, uint16_t); 1960 #undef xchg 1961 } 1962 tlen = 0; 1963 #ifdef INET6 1964 if (isipv6) 1965 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1966 #endif 1967 #if defined(INET) && defined(INET6) 1968 else 1969 #endif 1970 #ifdef INET 1971 tlen = sizeof (struct tcpiphdr); 1972 #endif 1973 if (port) 1974 tlen += sizeof (struct udphdr); 1975 #ifdef INVARIANTS 1976 m->m_len = 0; 1977 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1978 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1979 m, tlen, (long)M_TRAILINGSPACE(m))); 1980 #endif 1981 m->m_len = tlen; 1982 to.to_flags = 0; 1983 if (incl_opts) { 1984 /* Make sure we have room. */ 1985 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1986 m->m_next = m_get(M_NOWAIT, MT_DATA); 1987 if (m->m_next) { 1988 optp = mtod(m->m_next, u_char *); 1989 optm = m->m_next; 1990 } else 1991 incl_opts = false; 1992 } else { 1993 optp = (u_char *) (nth + 1); 1994 optm = m; 1995 } 1996 } 1997 if (incl_opts) { 1998 /* Timestamps. */ 1999 if (tp->t_flags & TF_RCVD_TSTMP) { 2000 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 2001 to.to_tsecr = tp->ts_recent; 2002 to.to_flags |= TOF_TS; 2003 } 2004 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2005 /* TCP-MD5 (RFC2385). */ 2006 if (tp->t_flags & TF_SIGNATURE) 2007 to.to_flags |= TOF_SIGNATURE; 2008 #endif 2009 /* Add the options. */ 2010 tlen += optlen = tcp_addoptions(&to, optp); 2011 2012 /* Update m_len in the correct mbuf. */ 2013 optm->m_len += optlen; 2014 } else 2015 optlen = 0; 2016 #ifdef INET6 2017 if (isipv6) { 2018 if (uh) { 2019 ulen = tlen - sizeof(struct ip6_hdr); 2020 uh->uh_ulen = htons(ulen); 2021 } 2022 ip6->ip6_flow = 0; 2023 ip6->ip6_vfc = IPV6_VERSION; 2024 if (port) 2025 ip6->ip6_nxt = IPPROTO_UDP; 2026 else 2027 ip6->ip6_nxt = IPPROTO_TCP; 2028 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 2029 } 2030 #endif 2031 #if defined(INET) && defined(INET6) 2032 else 2033 #endif 2034 #ifdef INET 2035 { 2036 if (uh) { 2037 ulen = tlen - sizeof(struct ip); 2038 uh->uh_ulen = htons(ulen); 2039 } 2040 ip->ip_len = htons(tlen); 2041 ip->ip_ttl = V_ip_defttl; 2042 if (port) { 2043 ip->ip_p = IPPROTO_UDP; 2044 } else { 2045 ip->ip_p = IPPROTO_TCP; 2046 } 2047 if (V_path_mtu_discovery) 2048 ip->ip_off |= htons(IP_DF); 2049 } 2050 #endif 2051 m->m_pkthdr.len = tlen; 2052 m->m_pkthdr.rcvif = NULL; 2053 #ifdef MAC 2054 if (inp != NULL) { 2055 /* 2056 * Packet is associated with a socket, so allow the 2057 * label of the response to reflect the socket label. 2058 */ 2059 INP_LOCK_ASSERT(inp); 2060 mac_inpcb_create_mbuf(inp, m); 2061 } else { 2062 /* 2063 * Packet is not associated with a socket, so possibly 2064 * update the label in place. 2065 */ 2066 mac_netinet_tcp_reply(m); 2067 } 2068 #endif 2069 nth->th_seq = htonl(seq); 2070 nth->th_ack = htonl(ack); 2071 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2072 tcp_set_flags(nth, flags); 2073 if (tp != NULL) 2074 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2075 else 2076 nth->th_win = htons((u_short)win); 2077 nth->th_urp = 0; 2078 2079 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2080 if (to.to_flags & TOF_SIGNATURE) { 2081 if (!TCPMD5_ENABLED() || 2082 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2083 m_freem(m); 2084 return; 2085 } 2086 } 2087 #endif 2088 2089 #ifdef INET6 2090 if (isipv6) { 2091 if (port) { 2092 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2093 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2094 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2095 nth->th_sum = 0; 2096 } else { 2097 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2098 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2099 nth->th_sum = in6_cksum_pseudo(ip6, 2100 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2101 } 2102 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2103 NULL, NULL); 2104 } 2105 #endif /* INET6 */ 2106 #if defined(INET6) && defined(INET) 2107 else 2108 #endif 2109 #ifdef INET 2110 { 2111 if (port) { 2112 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2113 htons(ulen + IPPROTO_UDP)); 2114 m->m_pkthdr.csum_flags = CSUM_UDP; 2115 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2116 nth->th_sum = 0; 2117 } else { 2118 m->m_pkthdr.csum_flags = CSUM_TCP; 2119 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2120 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2121 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2122 } 2123 } 2124 #endif /* INET */ 2125 #ifdef TCPDEBUG 2126 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2127 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2128 #endif 2129 TCP_PROBE3(debug__output, tp, th, m); 2130 if (flags & TH_RST) 2131 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2132 lgb = NULL; 2133 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2134 if (INP_WLOCKED(inp)) { 2135 union tcp_log_stackspecific log; 2136 struct timeval tv; 2137 2138 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2139 log.u_bbr.inhpts = tp->t_inpcb->inp_in_hpts; 2140 log.u_bbr.flex8 = 4; 2141 log.u_bbr.pkts_out = tp->t_maxseg; 2142 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2143 log.u_bbr.delivered = 0; 2144 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2145 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2146 } else { 2147 /* 2148 * We can not log the packet, since we only own the 2149 * read lock, but a write lock is needed. The read lock 2150 * is not upgraded to a write lock, since only getting 2151 * the read lock was done intentionally to improve the 2152 * handling of SYN flooding attacks. 2153 * This happens only for pure SYN segments received in 2154 * the initial CLOSED state, or received in a more 2155 * advanced state than listen and the UDP encapsulation 2156 * port is unexpected. 2157 * The incoming SYN segments do not really belong to 2158 * the TCP connection and the handling does not change 2159 * the state of the TCP connection. Therefore, the 2160 * sending of the RST segments is not logged. Please 2161 * note that also the incoming SYN segments are not 2162 * logged. 2163 * 2164 * The following code ensures that the above description 2165 * is and stays correct. 2166 */ 2167 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2168 (tp->t_state == TCPS_CLOSED || 2169 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2170 ("%s: Logging of TCP segment with flags 0x%b and " 2171 "UDP encapsulation port %u skipped in state %s", 2172 __func__, thflags, PRINT_TH_FLAGS, 2173 ntohs(port), tcpstates[tp->t_state])); 2174 } 2175 } 2176 2177 #ifdef INET6 2178 if (isipv6) { 2179 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2180 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2181 } 2182 #endif /* INET6 */ 2183 #if defined(INET) && defined(INET6) 2184 else 2185 #endif 2186 #ifdef INET 2187 { 2188 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2189 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2190 } 2191 #endif 2192 if (lgb != NULL) 2193 lgb->tlb_errno = output_ret; 2194 } 2195 2196 /* 2197 * Create a new TCP control block, making an 2198 * empty reassembly queue and hooking it to the argument 2199 * protocol control block. The `inp' parameter must have 2200 * come from the zone allocator set up in tcp_init(). 2201 */ 2202 struct tcpcb * 2203 tcp_newtcpcb(struct inpcb *inp) 2204 { 2205 struct tcpcb_mem *tm; 2206 struct tcpcb *tp; 2207 #ifdef INET6 2208 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2209 #endif /* INET6 */ 2210 2211 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2212 if (tm == NULL) 2213 return (NULL); 2214 tp = &tm->tcb; 2215 2216 /* Initialise cc_var struct for this tcpcb. */ 2217 tp->ccv = &tm->ccv; 2218 tp->ccv->type = IPPROTO_TCP; 2219 tp->ccv->ccvc.tcp = tp; 2220 rw_rlock(&tcp_function_lock); 2221 tp->t_fb = tcp_func_set_ptr; 2222 refcount_acquire(&tp->t_fb->tfb_refcnt); 2223 rw_runlock(&tcp_function_lock); 2224 /* 2225 * Use the current system default CC algorithm. 2226 */ 2227 cc_attach(tp, CC_DEFAULT_ALGO()); 2228 2229 /* 2230 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2231 * is called. 2232 */ 2233 in_pcbref(inp); /* Reference for tcpcb */ 2234 tp->t_inpcb = inp; 2235 2236 if (CC_ALGO(tp)->cb_init != NULL) 2237 if (CC_ALGO(tp)->cb_init(tp->ccv, NULL) > 0) { 2238 cc_detach(tp); 2239 if (tp->t_fb->tfb_tcp_fb_fini) 2240 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2241 in_pcbrele_wlocked(inp); 2242 refcount_release(&tp->t_fb->tfb_refcnt); 2243 uma_zfree(V_tcpcb_zone, tm); 2244 return (NULL); 2245 } 2246 2247 #ifdef TCP_HHOOK 2248 tp->osd = &tm->osd; 2249 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2250 if (tp->t_fb->tfb_tcp_fb_fini) 2251 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2252 in_pcbrele_wlocked(inp); 2253 refcount_release(&tp->t_fb->tfb_refcnt); 2254 uma_zfree(V_tcpcb_zone, tm); 2255 return (NULL); 2256 } 2257 #endif 2258 2259 #ifdef VIMAGE 2260 tp->t_vnet = inp->inp_vnet; 2261 #endif 2262 tp->t_timers = &tm->tt; 2263 TAILQ_INIT(&tp->t_segq); 2264 tp->t_maxseg = 2265 #ifdef INET6 2266 isipv6 ? V_tcp_v6mssdflt : 2267 #endif /* INET6 */ 2268 V_tcp_mssdflt; 2269 2270 /* Set up our timeouts. */ 2271 callout_init(&tp->t_timers->tt_rexmt, 1); 2272 callout_init(&tp->t_timers->tt_persist, 1); 2273 callout_init(&tp->t_timers->tt_keep, 1); 2274 callout_init(&tp->t_timers->tt_2msl, 1); 2275 callout_init(&tp->t_timers->tt_delack, 1); 2276 2277 if (V_tcp_do_rfc1323) 2278 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2279 if (V_tcp_do_sack) 2280 tp->t_flags |= TF_SACK_PERMIT; 2281 TAILQ_INIT(&tp->snd_holes); 2282 2283 /* 2284 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2285 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2286 * reasonable initial retransmit time. 2287 */ 2288 tp->t_srtt = TCPTV_SRTTBASE; 2289 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2290 tp->t_rttmin = tcp_rexmit_min; 2291 tp->t_rxtcur = tcp_rexmit_initial; 2292 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2293 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2294 tp->t_rcvtime = ticks; 2295 /* 2296 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2297 * because the socket may be bound to an IPv6 wildcard address, 2298 * which may match an IPv4-mapped IPv6 address. 2299 */ 2300 inp->inp_ip_ttl = V_ip_defttl; 2301 inp->inp_ppcb = tp; 2302 #ifdef TCPPCAP 2303 /* 2304 * Init the TCP PCAP queues. 2305 */ 2306 tcp_pcap_tcpcb_init(tp); 2307 #endif 2308 #ifdef TCP_BLACKBOX 2309 /* Initialize the per-TCPCB log data. */ 2310 tcp_log_tcpcbinit(tp); 2311 #endif 2312 tp->t_pacing_rate = -1; 2313 if (tp->t_fb->tfb_tcp_fb_init) { 2314 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2315 refcount_release(&tp->t_fb->tfb_refcnt); 2316 in_pcbrele_wlocked(inp); 2317 uma_zfree(V_tcpcb_zone, tm); 2318 return (NULL); 2319 } 2320 } 2321 #ifdef STATS 2322 if (V_tcp_perconn_stats_enable == 1) 2323 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2324 #endif 2325 if (V_tcp_do_lrd) 2326 tp->t_flags |= TF_LRD; 2327 return (tp); /* XXX */ 2328 } 2329 2330 /* 2331 * Drop a TCP connection, reporting 2332 * the specified error. If connection is synchronized, 2333 * then send a RST to peer. 2334 */ 2335 struct tcpcb * 2336 tcp_drop(struct tcpcb *tp, int errno) 2337 { 2338 struct socket *so = tp->t_inpcb->inp_socket; 2339 2340 NET_EPOCH_ASSERT(); 2341 INP_WLOCK_ASSERT(tp->t_inpcb); 2342 2343 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2344 tcp_state_change(tp, TCPS_CLOSED); 2345 /* Don't use tcp_output() here due to possible recursion. */ 2346 (void)tcp_output_nodrop(tp); 2347 TCPSTAT_INC(tcps_drops); 2348 } else 2349 TCPSTAT_INC(tcps_conndrops); 2350 if (errno == ETIMEDOUT && tp->t_softerror) 2351 errno = tp->t_softerror; 2352 so->so_error = errno; 2353 return (tcp_close(tp)); 2354 } 2355 2356 void 2357 tcp_discardcb(struct tcpcb *tp) 2358 { 2359 struct inpcb *inp = tp->t_inpcb; 2360 2361 INP_WLOCK_ASSERT(inp); 2362 2363 /* 2364 * Make sure that all of our timers are stopped before we delete the 2365 * PCB. 2366 * 2367 * If stopping a timer fails, we schedule a discard function in same 2368 * callout, and the last discard function called will take care of 2369 * deleting the tcpcb. 2370 */ 2371 tp->t_timers->tt_draincnt = 0; 2372 tcp_timer_stop(tp, TT_REXMT); 2373 tcp_timer_stop(tp, TT_PERSIST); 2374 tcp_timer_stop(tp, TT_KEEP); 2375 tcp_timer_stop(tp, TT_2MSL); 2376 tcp_timer_stop(tp, TT_DELACK); 2377 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2378 /* 2379 * Call the stop-all function of the methods, 2380 * this function should call the tcp_timer_stop() 2381 * method with each of the function specific timeouts. 2382 * That stop will be called via the tfb_tcp_timer_stop() 2383 * which should use the async drain function of the 2384 * callout system (see tcp_var.h). 2385 */ 2386 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2387 } 2388 2389 /* free the reassembly queue, if any */ 2390 tcp_reass_flush(tp); 2391 2392 #ifdef TCP_OFFLOAD 2393 /* Disconnect offload device, if any. */ 2394 if (tp->t_flags & TF_TOE) 2395 tcp_offload_detach(tp); 2396 #endif 2397 2398 tcp_free_sackholes(tp); 2399 2400 #ifdef TCPPCAP 2401 /* Free the TCP PCAP queues. */ 2402 tcp_pcap_drain(&(tp->t_inpkts)); 2403 tcp_pcap_drain(&(tp->t_outpkts)); 2404 #endif 2405 2406 /* Allow the CC algorithm to clean up after itself. */ 2407 if (CC_ALGO(tp)->cb_destroy != NULL) 2408 CC_ALGO(tp)->cb_destroy(tp->ccv); 2409 CC_DATA(tp) = NULL; 2410 /* Detach from the CC algorithm */ 2411 cc_detach(tp); 2412 2413 #ifdef TCP_HHOOK 2414 khelp_destroy_osd(tp->osd); 2415 #endif 2416 #ifdef STATS 2417 stats_blob_destroy(tp->t_stats); 2418 #endif 2419 2420 CC_ALGO(tp) = NULL; 2421 inp->inp_ppcb = NULL; 2422 if (tp->t_timers->tt_draincnt == 0) { 2423 bool released __diagused; 2424 2425 released = tcp_freecb(tp); 2426 KASSERT(!released, ("%s: inp %p should not have been released " 2427 "here", __func__, inp)); 2428 } 2429 } 2430 2431 bool 2432 tcp_freecb(struct tcpcb *tp) 2433 { 2434 struct inpcb *inp = tp->t_inpcb; 2435 struct socket *so = inp->inp_socket; 2436 #ifdef INET6 2437 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2438 #endif 2439 2440 INP_WLOCK_ASSERT(inp); 2441 MPASS(tp->t_timers->tt_draincnt == 0); 2442 2443 /* We own the last reference on tcpcb, let's free it. */ 2444 #ifdef TCP_BLACKBOX 2445 tcp_log_tcpcbfini(tp); 2446 #endif 2447 TCPSTATES_DEC(tp->t_state); 2448 if (tp->t_fb->tfb_tcp_fb_fini) 2449 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2450 2451 /* 2452 * If we got enough samples through the srtt filter, 2453 * save the rtt and rttvar in the routing entry. 2454 * 'Enough' is arbitrarily defined as 4 rtt samples. 2455 * 4 samples is enough for the srtt filter to converge 2456 * to within enough % of the correct value; fewer samples 2457 * and we could save a bogus rtt. The danger is not high 2458 * as tcp quickly recovers from everything. 2459 * XXX: Works very well but needs some more statistics! 2460 * 2461 * XXXRRS: Updating must be after the stack fini() since 2462 * that may be converting some internal representation of 2463 * say srtt etc into the general one used by other stacks. 2464 * Lets also at least protect against the so being NULL 2465 * as RW stated below. 2466 */ 2467 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2468 struct hc_metrics_lite metrics; 2469 uint32_t ssthresh; 2470 2471 bzero(&metrics, sizeof(metrics)); 2472 /* 2473 * Update the ssthresh always when the conditions below 2474 * are satisfied. This gives us better new start value 2475 * for the congestion avoidance for new connections. 2476 * ssthresh is only set if packet loss occurred on a session. 2477 * 2478 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2479 * being torn down. Ideally this code would not use 'so'. 2480 */ 2481 ssthresh = tp->snd_ssthresh; 2482 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2483 /* 2484 * convert the limit from user data bytes to 2485 * packets then to packet data bytes. 2486 */ 2487 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2488 if (ssthresh < 2) 2489 ssthresh = 2; 2490 ssthresh *= (tp->t_maxseg + 2491 #ifdef INET6 2492 (isipv6 ? sizeof (struct ip6_hdr) + 2493 sizeof (struct tcphdr) : 2494 #endif 2495 sizeof (struct tcpiphdr) 2496 #ifdef INET6 2497 ) 2498 #endif 2499 ); 2500 } else 2501 ssthresh = 0; 2502 metrics.rmx_ssthresh = ssthresh; 2503 2504 metrics.rmx_rtt = tp->t_srtt; 2505 metrics.rmx_rttvar = tp->t_rttvar; 2506 metrics.rmx_cwnd = tp->snd_cwnd; 2507 metrics.rmx_sendpipe = 0; 2508 metrics.rmx_recvpipe = 0; 2509 2510 tcp_hc_update(&inp->inp_inc, &metrics); 2511 } 2512 2513 refcount_release(&tp->t_fb->tfb_refcnt); 2514 uma_zfree(V_tcpcb_zone, tp); 2515 2516 return (in_pcbrele_wlocked(inp)); 2517 } 2518 2519 /* 2520 * Attempt to close a TCP control block, marking it as dropped, and freeing 2521 * the socket if we hold the only reference. 2522 */ 2523 struct tcpcb * 2524 tcp_close(struct tcpcb *tp) 2525 { 2526 struct inpcb *inp = tp->t_inpcb; 2527 struct socket *so; 2528 2529 INP_WLOCK_ASSERT(inp); 2530 2531 #ifdef TCP_OFFLOAD 2532 if (tp->t_state == TCPS_LISTEN) 2533 tcp_offload_listen_stop(tp); 2534 #endif 2535 /* 2536 * This releases the TFO pending counter resource for TFO listen 2537 * sockets as well as passively-created TFO sockets that transition 2538 * from SYN_RECEIVED to CLOSED. 2539 */ 2540 if (tp->t_tfo_pending) { 2541 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2542 tp->t_tfo_pending = NULL; 2543 } 2544 #ifdef TCPHPTS 2545 tcp_hpts_remove(inp); 2546 #endif 2547 in_pcbdrop(inp); 2548 TCPSTAT_INC(tcps_closed); 2549 if (tp->t_state != TCPS_CLOSED) 2550 tcp_state_change(tp, TCPS_CLOSED); 2551 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2552 so = inp->inp_socket; 2553 soisdisconnected(so); 2554 if (inp->inp_flags & INP_SOCKREF) { 2555 inp->inp_flags &= ~INP_SOCKREF; 2556 INP_WUNLOCK(inp); 2557 sorele(so); 2558 return (NULL); 2559 } 2560 return (tp); 2561 } 2562 2563 /* 2564 * Notify a tcp user of an asynchronous error; 2565 * store error as soft error, but wake up user 2566 * (for now, won't do anything until can select for soft error). 2567 * 2568 * Do not wake up user since there currently is no mechanism for 2569 * reporting soft errors (yet - a kqueue filter may be added). 2570 */ 2571 static struct inpcb * 2572 tcp_notify(struct inpcb *inp, int error) 2573 { 2574 struct tcpcb *tp; 2575 2576 INP_WLOCK_ASSERT(inp); 2577 2578 if ((inp->inp_flags & INP_TIMEWAIT) || 2579 (inp->inp_flags & INP_DROPPED)) 2580 return (inp); 2581 2582 tp = intotcpcb(inp); 2583 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2584 2585 /* 2586 * Ignore some errors if we are hooked up. 2587 * If connection hasn't completed, has retransmitted several times, 2588 * and receives a second error, give up now. This is better 2589 * than waiting a long time to establish a connection that 2590 * can never complete. 2591 */ 2592 if (tp->t_state == TCPS_ESTABLISHED && 2593 (error == EHOSTUNREACH || error == ENETUNREACH || 2594 error == EHOSTDOWN)) { 2595 if (inp->inp_route.ro_nh) { 2596 NH_FREE(inp->inp_route.ro_nh); 2597 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2598 } 2599 return (inp); 2600 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2601 tp->t_softerror) { 2602 tp = tcp_drop(tp, error); 2603 if (tp != NULL) 2604 return (inp); 2605 else 2606 return (NULL); 2607 } else { 2608 tp->t_softerror = error; 2609 return (inp); 2610 } 2611 #if 0 2612 wakeup( &so->so_timeo); 2613 sorwakeup(so); 2614 sowwakeup(so); 2615 #endif 2616 } 2617 2618 static int 2619 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2620 { 2621 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2622 INPLOOKUP_RLOCKPCB); 2623 struct xinpgen xig; 2624 struct inpcb *inp; 2625 int error; 2626 2627 if (req->newptr != NULL) 2628 return (EPERM); 2629 2630 if (req->oldptr == NULL) { 2631 int n; 2632 2633 n = V_tcbinfo.ipi_count + 2634 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2635 n += imax(n / 8, 10); 2636 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2637 return (0); 2638 } 2639 2640 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2641 return (error); 2642 2643 bzero(&xig, sizeof(xig)); 2644 xig.xig_len = sizeof xig; 2645 xig.xig_count = V_tcbinfo.ipi_count + 2646 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2647 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2648 xig.xig_sogen = so_gencnt; 2649 error = SYSCTL_OUT(req, &xig, sizeof xig); 2650 if (error) 2651 return (error); 2652 2653 error = syncache_pcblist(req); 2654 if (error) 2655 return (error); 2656 2657 while ((inp = inp_next(&inpi)) != NULL) { 2658 if (inp->inp_gencnt <= xig.xig_gen) { 2659 int crerr; 2660 2661 /* 2662 * XXX: This use of cr_cansee(), introduced with 2663 * TCP state changes, is not quite right, but for 2664 * now, better than nothing. 2665 */ 2666 if (inp->inp_flags & INP_TIMEWAIT) { 2667 if (intotw(inp) != NULL) 2668 crerr = cr_cansee(req->td->td_ucred, 2669 intotw(inp)->tw_cred); 2670 else 2671 crerr = EINVAL; /* Skip this inp. */ 2672 } else 2673 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2674 if (crerr == 0) { 2675 struct xtcpcb xt; 2676 2677 tcp_inptoxtp(inp, &xt); 2678 error = SYSCTL_OUT(req, &xt, sizeof xt); 2679 if (error) { 2680 INP_RUNLOCK(inp); 2681 break; 2682 } else 2683 continue; 2684 } 2685 } 2686 } 2687 2688 if (!error) { 2689 /* 2690 * Give the user an updated idea of our state. 2691 * If the generation differs from what we told 2692 * her before, she knows that something happened 2693 * while we were processing this request, and it 2694 * might be necessary to retry. 2695 */ 2696 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2697 xig.xig_sogen = so_gencnt; 2698 xig.xig_count = V_tcbinfo.ipi_count + 2699 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2700 error = SYSCTL_OUT(req, &xig, sizeof xig); 2701 } 2702 2703 return (error); 2704 } 2705 2706 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2707 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2708 NULL, 0, tcp_pcblist, "S,xtcpcb", 2709 "List of active TCP connections"); 2710 2711 #ifdef INET 2712 static int 2713 tcp_getcred(SYSCTL_HANDLER_ARGS) 2714 { 2715 struct xucred xuc; 2716 struct sockaddr_in addrs[2]; 2717 struct epoch_tracker et; 2718 struct inpcb *inp; 2719 int error; 2720 2721 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2722 if (error) 2723 return (error); 2724 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2725 if (error) 2726 return (error); 2727 NET_EPOCH_ENTER(et); 2728 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2729 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2730 NET_EPOCH_EXIT(et); 2731 if (inp != NULL) { 2732 if (inp->inp_socket == NULL) 2733 error = ENOENT; 2734 if (error == 0) 2735 error = cr_canseeinpcb(req->td->td_ucred, inp); 2736 if (error == 0) 2737 cru2x(inp->inp_cred, &xuc); 2738 INP_RUNLOCK(inp); 2739 } else 2740 error = ENOENT; 2741 if (error == 0) 2742 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2743 return (error); 2744 } 2745 2746 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2747 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2748 0, 0, tcp_getcred, "S,xucred", 2749 "Get the xucred of a TCP connection"); 2750 #endif /* INET */ 2751 2752 #ifdef INET6 2753 static int 2754 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2755 { 2756 struct epoch_tracker et; 2757 struct xucred xuc; 2758 struct sockaddr_in6 addrs[2]; 2759 struct inpcb *inp; 2760 int error; 2761 #ifdef INET 2762 int mapped = 0; 2763 #endif 2764 2765 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2766 if (error) 2767 return (error); 2768 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2769 if (error) 2770 return (error); 2771 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2772 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2773 return (error); 2774 } 2775 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2776 #ifdef INET 2777 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2778 mapped = 1; 2779 else 2780 #endif 2781 return (EINVAL); 2782 } 2783 2784 NET_EPOCH_ENTER(et); 2785 #ifdef INET 2786 if (mapped == 1) 2787 inp = in_pcblookup(&V_tcbinfo, 2788 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2789 addrs[1].sin6_port, 2790 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2791 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2792 else 2793 #endif 2794 inp = in6_pcblookup(&V_tcbinfo, 2795 &addrs[1].sin6_addr, addrs[1].sin6_port, 2796 &addrs[0].sin6_addr, addrs[0].sin6_port, 2797 INPLOOKUP_RLOCKPCB, NULL); 2798 NET_EPOCH_EXIT(et); 2799 if (inp != NULL) { 2800 if (inp->inp_socket == NULL) 2801 error = ENOENT; 2802 if (error == 0) 2803 error = cr_canseeinpcb(req->td->td_ucred, inp); 2804 if (error == 0) 2805 cru2x(inp->inp_cred, &xuc); 2806 INP_RUNLOCK(inp); 2807 } else 2808 error = ENOENT; 2809 if (error == 0) 2810 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2811 return (error); 2812 } 2813 2814 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2815 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2816 0, 0, tcp6_getcred, "S,xucred", 2817 "Get the xucred of a TCP6 connection"); 2818 #endif /* INET6 */ 2819 2820 #ifdef INET 2821 /* Path MTU to try next when a fragmentation-needed message is received. */ 2822 static inline int 2823 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2824 { 2825 int mtu = ntohs(icp->icmp_nextmtu); 2826 2827 /* If no alternative MTU was proposed, try the next smaller one. */ 2828 if (!mtu) 2829 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2830 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2831 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2832 2833 return (mtu); 2834 } 2835 2836 static void 2837 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2838 { 2839 struct ip *ip = vip; 2840 struct tcphdr *th; 2841 struct in_addr faddr; 2842 struct inpcb *inp; 2843 struct tcpcb *tp; 2844 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2845 struct icmp *icp; 2846 struct in_conninfo inc; 2847 tcp_seq icmp_tcp_seq; 2848 int mtu; 2849 2850 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2851 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2852 return; 2853 2854 if (cmd == PRC_MSGSIZE) 2855 notify = tcp_mtudisc_notify; 2856 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2857 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2858 cmd == PRC_TIMXCEED_INTRANS) && ip) 2859 notify = tcp_drop_syn_sent; 2860 2861 /* 2862 * Hostdead is ugly because it goes linearly through all PCBs. 2863 * XXX: We never get this from ICMP, otherwise it makes an 2864 * excellent DoS attack on machines with many connections. 2865 */ 2866 else if (cmd == PRC_HOSTDEAD) 2867 ip = NULL; 2868 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2869 return; 2870 2871 if (ip == NULL) { 2872 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2873 return; 2874 } 2875 2876 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2877 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2878 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2879 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2880 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2881 /* signal EHOSTDOWN, as it flushes the cached route */ 2882 inp = (*notify)(inp, EHOSTDOWN); 2883 goto out; 2884 } 2885 icmp_tcp_seq = th->th_seq; 2886 if (inp != NULL) { 2887 if (!(inp->inp_flags & INP_TIMEWAIT) && 2888 !(inp->inp_flags & INP_DROPPED) && 2889 !(inp->inp_socket == NULL)) { 2890 tp = intotcpcb(inp); 2891 #ifdef TCP_OFFLOAD 2892 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2893 /* 2894 * MTU discovery for offloaded connections. Let 2895 * the TOE driver verify seq# and process it. 2896 */ 2897 mtu = tcp_next_pmtu(icp, ip); 2898 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2899 goto out; 2900 } 2901 #endif 2902 if (tp->t_port != port) { 2903 goto out; 2904 } 2905 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2906 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2907 if (cmd == PRC_MSGSIZE) { 2908 /* 2909 * MTU discovery: we got a needfrag and 2910 * will potentially try a lower MTU. 2911 */ 2912 mtu = tcp_next_pmtu(icp, ip); 2913 2914 /* 2915 * Only process the offered MTU if it 2916 * is smaller than the current one. 2917 */ 2918 if (mtu < tp->t_maxseg + 2919 sizeof(struct tcpiphdr)) { 2920 bzero(&inc, sizeof(inc)); 2921 inc.inc_faddr = faddr; 2922 inc.inc_fibnum = 2923 inp->inp_inc.inc_fibnum; 2924 tcp_hc_updatemtu(&inc, mtu); 2925 inp = tcp_mtudisc(inp, mtu); 2926 } 2927 } else 2928 inp = (*notify)(inp, 2929 inetctlerrmap[cmd]); 2930 } 2931 } 2932 } else { 2933 bzero(&inc, sizeof(inc)); 2934 inc.inc_fport = th->th_dport; 2935 inc.inc_lport = th->th_sport; 2936 inc.inc_faddr = faddr; 2937 inc.inc_laddr = ip->ip_src; 2938 syncache_unreach(&inc, icmp_tcp_seq, port); 2939 } 2940 out: 2941 if (inp != NULL) 2942 INP_WUNLOCK(inp); 2943 } 2944 2945 void 2946 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2947 { 2948 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2949 } 2950 2951 void 2952 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2953 { 2954 /* Its a tunneled TCP over UDP icmp */ 2955 struct ip *outer_ip, *inner_ip; 2956 struct icmp *icmp; 2957 struct udphdr *udp; 2958 struct tcphdr *th, ttemp; 2959 int i_hlen, o_len; 2960 uint16_t port; 2961 2962 inner_ip = (struct ip *)vip; 2963 icmp = (struct icmp *)((caddr_t)inner_ip - 2964 (sizeof(struct icmp) - sizeof(struct ip))); 2965 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2966 i_hlen = inner_ip->ip_hl << 2; 2967 o_len = ntohs(outer_ip->ip_len); 2968 if (o_len < 2969 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2970 /* Not enough data present */ 2971 return; 2972 } 2973 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2974 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2975 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2976 return; 2977 } 2978 port = udp->uh_dport; 2979 th = (struct tcphdr *)(udp + 1); 2980 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2981 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2982 /* Now adjust down the size of the outer IP header */ 2983 o_len -= sizeof(struct udphdr); 2984 outer_ip->ip_len = htons(o_len); 2985 /* Now call in to the normal handling code */ 2986 tcp_ctlinput_with_port(cmd, sa, vip, port); 2987 } 2988 #endif /* INET */ 2989 2990 #ifdef INET6 2991 static inline int 2992 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2993 { 2994 int mtu = ntohl(icmp6->icmp6_mtu); 2995 2996 /* 2997 * If no alternative MTU was proposed, or the proposed MTU was too 2998 * small, set to the min. 2999 */ 3000 if (mtu < IPV6_MMTU) 3001 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3002 return (mtu); 3003 } 3004 3005 static void 3006 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3007 { 3008 struct in6_addr *dst; 3009 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3010 struct ip6_hdr *ip6; 3011 struct mbuf *m; 3012 struct inpcb *inp; 3013 struct tcpcb *tp; 3014 struct icmp6_hdr *icmp6; 3015 struct ip6ctlparam *ip6cp = NULL; 3016 const struct sockaddr_in6 *sa6_src = NULL; 3017 struct in_conninfo inc; 3018 struct tcp_ports { 3019 uint16_t th_sport; 3020 uint16_t th_dport; 3021 } t_ports; 3022 tcp_seq icmp_tcp_seq; 3023 unsigned int mtu; 3024 unsigned int off; 3025 3026 if (sa->sa_family != AF_INET6 || 3027 sa->sa_len != sizeof(struct sockaddr_in6)) 3028 return; 3029 3030 /* if the parameter is from icmp6, decode it. */ 3031 if (d != NULL) { 3032 ip6cp = (struct ip6ctlparam *)d; 3033 icmp6 = ip6cp->ip6c_icmp6; 3034 m = ip6cp->ip6c_m; 3035 ip6 = ip6cp->ip6c_ip6; 3036 off = ip6cp->ip6c_off; 3037 sa6_src = ip6cp->ip6c_src; 3038 dst = ip6cp->ip6c_finaldst; 3039 } else { 3040 m = NULL; 3041 ip6 = NULL; 3042 off = 0; /* fool gcc */ 3043 sa6_src = &sa6_any; 3044 dst = NULL; 3045 } 3046 3047 if (cmd == PRC_MSGSIZE) 3048 notify = tcp_mtudisc_notify; 3049 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3050 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3051 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3052 notify = tcp_drop_syn_sent; 3053 3054 /* 3055 * Hostdead is ugly because it goes linearly through all PCBs. 3056 * XXX: We never get this from ICMP, otherwise it makes an 3057 * excellent DoS attack on machines with many connections. 3058 */ 3059 else if (cmd == PRC_HOSTDEAD) 3060 ip6 = NULL; 3061 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3062 return; 3063 3064 if (ip6 == NULL) { 3065 in6_pcbnotify(&V_tcbinfo, sa, 0, 3066 (const struct sockaddr *)sa6_src, 3067 0, cmd, NULL, notify); 3068 return; 3069 } 3070 3071 /* Check if we can safely get the ports from the tcp hdr */ 3072 if (m == NULL || 3073 (m->m_pkthdr.len < 3074 (int32_t) (off + sizeof(struct tcp_ports)))) { 3075 return; 3076 } 3077 bzero(&t_ports, sizeof(struct tcp_ports)); 3078 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3079 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3080 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3081 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3082 /* signal EHOSTDOWN, as it flushes the cached route */ 3083 inp = (*notify)(inp, EHOSTDOWN); 3084 goto out; 3085 } 3086 off += sizeof(struct tcp_ports); 3087 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3088 goto out; 3089 } 3090 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3091 if (inp != NULL) { 3092 if (!(inp->inp_flags & INP_TIMEWAIT) && 3093 !(inp->inp_flags & INP_DROPPED) && 3094 !(inp->inp_socket == NULL)) { 3095 tp = intotcpcb(inp); 3096 #ifdef TCP_OFFLOAD 3097 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3098 /* MTU discovery for offloaded connections. */ 3099 mtu = tcp6_next_pmtu(icmp6); 3100 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3101 goto out; 3102 } 3103 #endif 3104 if (tp->t_port != port) { 3105 goto out; 3106 } 3107 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3108 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3109 if (cmd == PRC_MSGSIZE) { 3110 /* 3111 * MTU discovery: 3112 * If we got a needfrag set the MTU 3113 * in the route to the suggested new 3114 * value (if given) and then notify. 3115 */ 3116 mtu = tcp6_next_pmtu(icmp6); 3117 3118 bzero(&inc, sizeof(inc)); 3119 inc.inc_fibnum = M_GETFIB(m); 3120 inc.inc_flags |= INC_ISIPV6; 3121 inc.inc6_faddr = *dst; 3122 if (in6_setscope(&inc.inc6_faddr, 3123 m->m_pkthdr.rcvif, NULL)) 3124 goto out; 3125 /* 3126 * Only process the offered MTU if it 3127 * is smaller than the current one. 3128 */ 3129 if (mtu < tp->t_maxseg + 3130 sizeof (struct tcphdr) + 3131 sizeof (struct ip6_hdr)) { 3132 tcp_hc_updatemtu(&inc, mtu); 3133 tcp_mtudisc(inp, mtu); 3134 ICMP6STAT_INC(icp6s_pmtuchg); 3135 } 3136 } else 3137 inp = (*notify)(inp, 3138 inet6ctlerrmap[cmd]); 3139 } 3140 } 3141 } else { 3142 bzero(&inc, sizeof(inc)); 3143 inc.inc_fibnum = M_GETFIB(m); 3144 inc.inc_flags |= INC_ISIPV6; 3145 inc.inc_fport = t_ports.th_dport; 3146 inc.inc_lport = t_ports.th_sport; 3147 inc.inc6_faddr = *dst; 3148 inc.inc6_laddr = ip6->ip6_src; 3149 syncache_unreach(&inc, icmp_tcp_seq, port); 3150 } 3151 out: 3152 if (inp != NULL) 3153 INP_WUNLOCK(inp); 3154 } 3155 3156 void 3157 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3158 { 3159 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3160 } 3161 3162 void 3163 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3164 { 3165 struct ip6ctlparam *ip6cp; 3166 struct mbuf *m; 3167 struct udphdr *udp; 3168 uint16_t port; 3169 3170 ip6cp = (struct ip6ctlparam *)d; 3171 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3172 if (m == NULL) { 3173 return; 3174 } 3175 udp = mtod(m, struct udphdr *); 3176 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3177 return; 3178 } 3179 port = udp->uh_dport; 3180 m_adj(m, sizeof(struct udphdr)); 3181 if ((m->m_flags & M_PKTHDR) == 0) { 3182 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3183 } 3184 /* Now call in to the normal handling code */ 3185 tcp6_ctlinput_with_port(cmd, sa, d, port); 3186 } 3187 3188 #endif /* INET6 */ 3189 3190 static uint32_t 3191 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3192 { 3193 SIPHASH_CTX ctx; 3194 uint32_t hash[2]; 3195 3196 KASSERT(len >= SIPHASH_KEY_LENGTH, 3197 ("%s: keylen %u too short ", __func__, len)); 3198 SipHash24_Init(&ctx); 3199 SipHash_SetKey(&ctx, (uint8_t *)key); 3200 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3201 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3202 switch (inc->inc_flags & INC_ISIPV6) { 3203 #ifdef INET 3204 case 0: 3205 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3206 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3207 break; 3208 #endif 3209 #ifdef INET6 3210 case INC_ISIPV6: 3211 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3212 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3213 break; 3214 #endif 3215 } 3216 SipHash_Final((uint8_t *)hash, &ctx); 3217 3218 return (hash[0] ^ hash[1]); 3219 } 3220 3221 uint32_t 3222 tcp_new_ts_offset(struct in_conninfo *inc) 3223 { 3224 struct in_conninfo inc_store, *local_inc; 3225 3226 if (!V_tcp_ts_offset_per_conn) { 3227 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3228 inc_store.inc_lport = 0; 3229 inc_store.inc_fport = 0; 3230 local_inc = &inc_store; 3231 } else { 3232 local_inc = inc; 3233 } 3234 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3235 sizeof(V_ts_offset_secret))); 3236 } 3237 3238 /* 3239 * Following is where TCP initial sequence number generation occurs. 3240 * 3241 * There are two places where we must use initial sequence numbers: 3242 * 1. In SYN-ACK packets. 3243 * 2. In SYN packets. 3244 * 3245 * All ISNs for SYN-ACK packets are generated by the syncache. See 3246 * tcp_syncache.c for details. 3247 * 3248 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3249 * depends on this property. In addition, these ISNs should be 3250 * unguessable so as to prevent connection hijacking. To satisfy 3251 * the requirements of this situation, the algorithm outlined in 3252 * RFC 1948 is used, with only small modifications. 3253 * 3254 * Implementation details: 3255 * 3256 * Time is based off the system timer, and is corrected so that it 3257 * increases by one megabyte per second. This allows for proper 3258 * recycling on high speed LANs while still leaving over an hour 3259 * before rollover. 3260 * 3261 * As reading the *exact* system time is too expensive to be done 3262 * whenever setting up a TCP connection, we increment the time 3263 * offset in two ways. First, a small random positive increment 3264 * is added to isn_offset for each connection that is set up. 3265 * Second, the function tcp_isn_tick fires once per clock tick 3266 * and increments isn_offset as necessary so that sequence numbers 3267 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3268 * random positive increments serve only to ensure that the same 3269 * exact sequence number is never sent out twice (as could otherwise 3270 * happen when a port is recycled in less than the system tick 3271 * interval.) 3272 * 3273 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3274 * between seeding of isn_secret. This is normally set to zero, 3275 * as reseeding should not be necessary. 3276 * 3277 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3278 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3279 * general, this means holding an exclusive (write) lock. 3280 */ 3281 3282 #define ISN_BYTES_PER_SECOND 1048576 3283 #define ISN_STATIC_INCREMENT 4096 3284 #define ISN_RANDOM_INCREMENT (4096 - 1) 3285 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3286 3287 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3288 VNET_DEFINE_STATIC(int, isn_last); 3289 VNET_DEFINE_STATIC(int, isn_last_reseed); 3290 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3291 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3292 3293 #define V_isn_secret VNET(isn_secret) 3294 #define V_isn_last VNET(isn_last) 3295 #define V_isn_last_reseed VNET(isn_last_reseed) 3296 #define V_isn_offset VNET(isn_offset) 3297 #define V_isn_offset_old VNET(isn_offset_old) 3298 3299 tcp_seq 3300 tcp_new_isn(struct in_conninfo *inc) 3301 { 3302 tcp_seq new_isn; 3303 u_int32_t projected_offset; 3304 3305 ISN_LOCK(); 3306 /* Seed if this is the first use, reseed if requested. */ 3307 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3308 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3309 < (u_int)ticks))) { 3310 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3311 V_isn_last_reseed = ticks; 3312 } 3313 3314 /* Compute the hash and return the ISN. */ 3315 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3316 sizeof(V_isn_secret)); 3317 V_isn_offset += ISN_STATIC_INCREMENT + 3318 (arc4random() & ISN_RANDOM_INCREMENT); 3319 if (ticks != V_isn_last) { 3320 projected_offset = V_isn_offset_old + 3321 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3322 if (SEQ_GT(projected_offset, V_isn_offset)) 3323 V_isn_offset = projected_offset; 3324 V_isn_offset_old = V_isn_offset; 3325 V_isn_last = ticks; 3326 } 3327 new_isn += V_isn_offset; 3328 ISN_UNLOCK(); 3329 return (new_isn); 3330 } 3331 3332 /* 3333 * When a specific ICMP unreachable message is received and the 3334 * connection state is SYN-SENT, drop the connection. This behavior 3335 * is controlled by the icmp_may_rst sysctl. 3336 */ 3337 struct inpcb * 3338 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3339 { 3340 struct tcpcb *tp; 3341 3342 NET_EPOCH_ASSERT(); 3343 INP_WLOCK_ASSERT(inp); 3344 3345 if ((inp->inp_flags & INP_TIMEWAIT) || 3346 (inp->inp_flags & INP_DROPPED)) 3347 return (inp); 3348 3349 tp = intotcpcb(inp); 3350 if (tp->t_state != TCPS_SYN_SENT) 3351 return (inp); 3352 3353 if (IS_FASTOPEN(tp->t_flags)) 3354 tcp_fastopen_disable_path(tp); 3355 3356 tp = tcp_drop(tp, errno); 3357 if (tp != NULL) 3358 return (inp); 3359 else 3360 return (NULL); 3361 } 3362 3363 /* 3364 * When `need fragmentation' ICMP is received, update our idea of the MSS 3365 * based on the new value. Also nudge TCP to send something, since we 3366 * know the packet we just sent was dropped. 3367 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3368 */ 3369 static struct inpcb * 3370 tcp_mtudisc_notify(struct inpcb *inp, int error) 3371 { 3372 3373 return (tcp_mtudisc(inp, -1)); 3374 } 3375 3376 static struct inpcb * 3377 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3378 { 3379 struct tcpcb *tp; 3380 struct socket *so; 3381 3382 INP_WLOCK_ASSERT(inp); 3383 if ((inp->inp_flags & INP_TIMEWAIT) || 3384 (inp->inp_flags & INP_DROPPED)) 3385 return (inp); 3386 3387 tp = intotcpcb(inp); 3388 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3389 3390 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3391 3392 so = inp->inp_socket; 3393 SOCKBUF_LOCK(&so->so_snd); 3394 /* If the mss is larger than the socket buffer, decrease the mss. */ 3395 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3396 tp->t_maxseg = so->so_snd.sb_hiwat; 3397 SOCKBUF_UNLOCK(&so->so_snd); 3398 3399 TCPSTAT_INC(tcps_mturesent); 3400 tp->t_rtttime = 0; 3401 tp->snd_nxt = tp->snd_una; 3402 tcp_free_sackholes(tp); 3403 tp->snd_recover = tp->snd_max; 3404 if (tp->t_flags & TF_SACK_PERMIT) 3405 EXIT_FASTRECOVERY(tp->t_flags); 3406 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3407 /* 3408 * Conceptually the snd_nxt setting 3409 * and freeing sack holes should 3410 * be done by the default stacks 3411 * own tfb_tcp_mtu_chg(). 3412 */ 3413 tp->t_fb->tfb_tcp_mtu_chg(tp); 3414 } 3415 if (tcp_output(tp) < 0) 3416 return (NULL); 3417 else 3418 return (inp); 3419 } 3420 3421 #ifdef INET 3422 /* 3423 * Look-up the routing entry to the peer of this inpcb. If no route 3424 * is found and it cannot be allocated, then return 0. This routine 3425 * is called by TCP routines that access the rmx structure and by 3426 * tcp_mss_update to get the peer/interface MTU. 3427 */ 3428 uint32_t 3429 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3430 { 3431 struct nhop_object *nh; 3432 struct ifnet *ifp; 3433 uint32_t maxmtu = 0; 3434 3435 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3436 3437 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3438 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3439 if (nh == NULL) 3440 return (0); 3441 3442 ifp = nh->nh_ifp; 3443 maxmtu = nh->nh_mtu; 3444 3445 /* Report additional interface capabilities. */ 3446 if (cap != NULL) { 3447 if (ifp->if_capenable & IFCAP_TSO4 && 3448 ifp->if_hwassist & CSUM_TSO) { 3449 cap->ifcap |= CSUM_TSO; 3450 cap->tsomax = ifp->if_hw_tsomax; 3451 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3452 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3453 } 3454 } 3455 } 3456 return (maxmtu); 3457 } 3458 #endif /* INET */ 3459 3460 #ifdef INET6 3461 uint32_t 3462 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3463 { 3464 struct nhop_object *nh; 3465 struct in6_addr dst6; 3466 uint32_t scopeid; 3467 struct ifnet *ifp; 3468 uint32_t maxmtu = 0; 3469 3470 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3471 3472 if (inc->inc_flags & INC_IPV6MINMTU) 3473 return (IPV6_MMTU); 3474 3475 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3476 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3477 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3478 if (nh == NULL) 3479 return (0); 3480 3481 ifp = nh->nh_ifp; 3482 maxmtu = nh->nh_mtu; 3483 3484 /* Report additional interface capabilities. */ 3485 if (cap != NULL) { 3486 if (ifp->if_capenable & IFCAP_TSO6 && 3487 ifp->if_hwassist & CSUM_TSO) { 3488 cap->ifcap |= CSUM_TSO; 3489 cap->tsomax = ifp->if_hw_tsomax; 3490 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3491 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3492 } 3493 } 3494 } 3495 3496 return (maxmtu); 3497 } 3498 3499 /* 3500 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3501 * 3502 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3503 * The right place to do that is ip6_setpktopt() that has just been 3504 * executed. By the way it just filled ip6po_minmtu for us. 3505 */ 3506 void 3507 tcp6_use_min_mtu(struct tcpcb *tp) 3508 { 3509 struct inpcb *inp = tp->t_inpcb; 3510 3511 INP_WLOCK_ASSERT(inp); 3512 /* 3513 * In case of the IPV6_USE_MIN_MTU socket 3514 * option, the INC_IPV6MINMTU flag to announce 3515 * a corresponding MSS during the initial 3516 * handshake. If the TCP connection is not in 3517 * the front states, just reduce the MSS being 3518 * used. This avoids the sending of TCP 3519 * segments which will be fragmented at the 3520 * IPv6 layer. 3521 */ 3522 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3523 if ((tp->t_state >= TCPS_SYN_SENT) && 3524 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3525 struct ip6_pktopts *opt; 3526 3527 opt = inp->in6p_outputopts; 3528 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3529 tp->t_maxseg > TCP6_MSS) 3530 tp->t_maxseg = TCP6_MSS; 3531 } 3532 } 3533 #endif /* INET6 */ 3534 3535 /* 3536 * Calculate effective SMSS per RFC5681 definition for a given TCP 3537 * connection at its current state, taking into account SACK and etc. 3538 */ 3539 u_int 3540 tcp_maxseg(const struct tcpcb *tp) 3541 { 3542 u_int optlen; 3543 3544 if (tp->t_flags & TF_NOOPT) 3545 return (tp->t_maxseg); 3546 3547 /* 3548 * Here we have a simplified code from tcp_addoptions(), 3549 * without a proper loop, and having most of paddings hardcoded. 3550 * We might make mistakes with padding here in some edge cases, 3551 * but this is harmless, since result of tcp_maxseg() is used 3552 * only in cwnd and ssthresh estimations. 3553 */ 3554 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3555 if (tp->t_flags & TF_RCVD_TSTMP) 3556 optlen = TCPOLEN_TSTAMP_APPA; 3557 else 3558 optlen = 0; 3559 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3560 if (tp->t_flags & TF_SIGNATURE) 3561 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3562 #endif 3563 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3564 optlen += TCPOLEN_SACKHDR; 3565 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3566 optlen = PADTCPOLEN(optlen); 3567 } 3568 } else { 3569 if (tp->t_flags & TF_REQ_TSTMP) 3570 optlen = TCPOLEN_TSTAMP_APPA; 3571 else 3572 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3573 if (tp->t_flags & TF_REQ_SCALE) 3574 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3575 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3576 if (tp->t_flags & TF_SIGNATURE) 3577 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3578 #endif 3579 if (tp->t_flags & TF_SACK_PERMIT) 3580 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3581 } 3582 #undef PAD 3583 optlen = min(optlen, TCP_MAXOLEN); 3584 return (tp->t_maxseg - optlen); 3585 } 3586 3587 3588 u_int 3589 tcp_fixed_maxseg(const struct tcpcb *tp) 3590 { 3591 int optlen; 3592 3593 if (tp->t_flags & TF_NOOPT) 3594 return (tp->t_maxseg); 3595 3596 /* 3597 * Here we have a simplified code from tcp_addoptions(), 3598 * without a proper loop, and having most of paddings hardcoded. 3599 * We only consider fixed options that we would send every 3600 * time I.e. SACK is not considered. This is important 3601 * for cc modules to figure out what the modulo of the 3602 * cwnd should be. 3603 */ 3604 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3605 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3606 if (tp->t_flags & TF_RCVD_TSTMP) 3607 optlen = TCPOLEN_TSTAMP_APPA; 3608 else 3609 optlen = 0; 3610 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3611 if (tp->t_flags & TF_SIGNATURE) 3612 optlen += PAD(TCPOLEN_SIGNATURE); 3613 #endif 3614 } else { 3615 if (tp->t_flags & TF_REQ_TSTMP) 3616 optlen = TCPOLEN_TSTAMP_APPA; 3617 else 3618 optlen = PAD(TCPOLEN_MAXSEG); 3619 if (tp->t_flags & TF_REQ_SCALE) 3620 optlen += PAD(TCPOLEN_WINDOW); 3621 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3622 if (tp->t_flags & TF_SIGNATURE) 3623 optlen += PAD(TCPOLEN_SIGNATURE); 3624 #endif 3625 if (tp->t_flags & TF_SACK_PERMIT) 3626 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3627 } 3628 #undef PAD 3629 optlen = min(optlen, TCP_MAXOLEN); 3630 return (tp->t_maxseg - optlen); 3631 } 3632 3633 3634 3635 static int 3636 sysctl_drop(SYSCTL_HANDLER_ARGS) 3637 { 3638 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3639 struct sockaddr_storage addrs[2]; 3640 struct inpcb *inp; 3641 struct tcpcb *tp; 3642 struct tcptw *tw; 3643 #ifdef INET 3644 struct sockaddr_in *fin = NULL, *lin = NULL; 3645 #endif 3646 struct epoch_tracker et; 3647 #ifdef INET6 3648 struct sockaddr_in6 *fin6, *lin6; 3649 #endif 3650 int error; 3651 3652 inp = NULL; 3653 #ifdef INET6 3654 fin6 = lin6 = NULL; 3655 #endif 3656 error = 0; 3657 3658 if (req->oldptr != NULL || req->oldlen != 0) 3659 return (EINVAL); 3660 if (req->newptr == NULL) 3661 return (EPERM); 3662 if (req->newlen < sizeof(addrs)) 3663 return (ENOMEM); 3664 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3665 if (error) 3666 return (error); 3667 3668 switch (addrs[0].ss_family) { 3669 #ifdef INET6 3670 case AF_INET6: 3671 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3672 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3673 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3674 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3675 return (EINVAL); 3676 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3677 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3678 return (EINVAL); 3679 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3680 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3681 #ifdef INET 3682 fin = (struct sockaddr_in *)&addrs[0]; 3683 lin = (struct sockaddr_in *)&addrs[1]; 3684 #endif 3685 break; 3686 } 3687 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3688 if (error) 3689 return (error); 3690 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3691 if (error) 3692 return (error); 3693 break; 3694 #endif 3695 #ifdef INET 3696 case AF_INET: 3697 fin = (struct sockaddr_in *)&addrs[0]; 3698 lin = (struct sockaddr_in *)&addrs[1]; 3699 if (fin->sin_len != sizeof(struct sockaddr_in) || 3700 lin->sin_len != sizeof(struct sockaddr_in)) 3701 return (EINVAL); 3702 break; 3703 #endif 3704 default: 3705 return (EINVAL); 3706 } 3707 NET_EPOCH_ENTER(et); 3708 switch (addrs[0].ss_family) { 3709 #ifdef INET6 3710 case AF_INET6: 3711 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3712 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3713 INPLOOKUP_WLOCKPCB, NULL); 3714 break; 3715 #endif 3716 #ifdef INET 3717 case AF_INET: 3718 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3719 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3720 break; 3721 #endif 3722 } 3723 if (inp != NULL) { 3724 if (inp->inp_flags & INP_TIMEWAIT) { 3725 /* 3726 * XXXRW: There currently exists a state where an 3727 * inpcb is present, but its timewait state has been 3728 * discarded. For now, don't allow dropping of this 3729 * type of inpcb. 3730 */ 3731 tw = intotw(inp); 3732 if (tw != NULL) 3733 tcp_twclose(tw, 0); 3734 else 3735 INP_WUNLOCK(inp); 3736 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3737 !SOLISTENING(inp->inp_socket)) { 3738 tp = intotcpcb(inp); 3739 tp = tcp_drop(tp, ECONNABORTED); 3740 if (tp != NULL) 3741 INP_WUNLOCK(inp); 3742 } else 3743 INP_WUNLOCK(inp); 3744 } else 3745 error = ESRCH; 3746 NET_EPOCH_EXIT(et); 3747 return (error); 3748 } 3749 3750 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3751 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3752 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3753 "Drop TCP connection"); 3754 3755 static int 3756 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3757 { 3758 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3759 &tcp_ctloutput_set)); 3760 } 3761 3762 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3763 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3764 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3765 "Set socket option for TCP endpoint"); 3766 3767 #ifdef KERN_TLS 3768 static int 3769 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3770 { 3771 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3772 struct sockaddr_storage addrs[2]; 3773 struct inpcb *inp; 3774 #ifdef INET 3775 struct sockaddr_in *fin = NULL, *lin = NULL; 3776 #endif 3777 struct epoch_tracker et; 3778 #ifdef INET6 3779 struct sockaddr_in6 *fin6, *lin6; 3780 #endif 3781 int error; 3782 3783 inp = NULL; 3784 #ifdef INET6 3785 fin6 = lin6 = NULL; 3786 #endif 3787 error = 0; 3788 3789 if (req->oldptr != NULL || req->oldlen != 0) 3790 return (EINVAL); 3791 if (req->newptr == NULL) 3792 return (EPERM); 3793 if (req->newlen < sizeof(addrs)) 3794 return (ENOMEM); 3795 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3796 if (error) 3797 return (error); 3798 3799 switch (addrs[0].ss_family) { 3800 #ifdef INET6 3801 case AF_INET6: 3802 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3803 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3804 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3805 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3806 return (EINVAL); 3807 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3808 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3809 return (EINVAL); 3810 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3811 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3812 #ifdef INET 3813 fin = (struct sockaddr_in *)&addrs[0]; 3814 lin = (struct sockaddr_in *)&addrs[1]; 3815 #endif 3816 break; 3817 } 3818 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3819 if (error) 3820 return (error); 3821 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3822 if (error) 3823 return (error); 3824 break; 3825 #endif 3826 #ifdef INET 3827 case AF_INET: 3828 fin = (struct sockaddr_in *)&addrs[0]; 3829 lin = (struct sockaddr_in *)&addrs[1]; 3830 if (fin->sin_len != sizeof(struct sockaddr_in) || 3831 lin->sin_len != sizeof(struct sockaddr_in)) 3832 return (EINVAL); 3833 break; 3834 #endif 3835 default: 3836 return (EINVAL); 3837 } 3838 NET_EPOCH_ENTER(et); 3839 switch (addrs[0].ss_family) { 3840 #ifdef INET6 3841 case AF_INET6: 3842 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3843 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3844 INPLOOKUP_WLOCKPCB, NULL); 3845 break; 3846 #endif 3847 #ifdef INET 3848 case AF_INET: 3849 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3850 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3851 break; 3852 #endif 3853 } 3854 NET_EPOCH_EXIT(et); 3855 if (inp != NULL) { 3856 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3857 inp->inp_socket == NULL) { 3858 error = ECONNRESET; 3859 INP_WUNLOCK(inp); 3860 } else { 3861 struct socket *so; 3862 3863 so = inp->inp_socket; 3864 soref(so); 3865 error = ktls_set_tx_mode(so, 3866 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3867 INP_WUNLOCK(inp); 3868 sorele(so); 3869 } 3870 } else 3871 error = ESRCH; 3872 return (error); 3873 } 3874 3875 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3876 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3877 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3878 "Switch TCP connection to SW TLS"); 3879 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3880 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3881 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3882 "Switch TCP connection to ifnet TLS"); 3883 #endif 3884 3885 /* 3886 * Generate a standardized TCP log line for use throughout the 3887 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3888 * allow use in the interrupt context. 3889 * 3890 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3891 * NB: The function may return NULL if memory allocation failed. 3892 * 3893 * Due to header inclusion and ordering limitations the struct ip 3894 * and ip6_hdr pointers have to be passed as void pointers. 3895 */ 3896 char * 3897 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3898 const void *ip6hdr) 3899 { 3900 3901 /* Is logging enabled? */ 3902 if (V_tcp_log_in_vain == 0) 3903 return (NULL); 3904 3905 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3906 } 3907 3908 char * 3909 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3910 const void *ip6hdr) 3911 { 3912 3913 /* Is logging enabled? */ 3914 if (tcp_log_debug == 0) 3915 return (NULL); 3916 3917 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3918 } 3919 3920 static char * 3921 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3922 const void *ip6hdr) 3923 { 3924 char *s, *sp; 3925 size_t size; 3926 #ifdef INET 3927 const struct ip *ip = (const struct ip *)ip4hdr; 3928 #endif 3929 #ifdef INET6 3930 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3931 #endif /* INET6 */ 3932 3933 /* 3934 * The log line looks like this: 3935 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3936 */ 3937 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3938 sizeof(PRINT_TH_FLAGS) + 1 + 3939 #ifdef INET6 3940 2 * INET6_ADDRSTRLEN; 3941 #else 3942 2 * INET_ADDRSTRLEN; 3943 #endif /* INET6 */ 3944 3945 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3946 if (s == NULL) 3947 return (NULL); 3948 3949 strcat(s, "TCP: ["); 3950 sp = s + strlen(s); 3951 3952 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3953 inet_ntoa_r(inc->inc_faddr, sp); 3954 sp = s + strlen(s); 3955 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3956 sp = s + strlen(s); 3957 inet_ntoa_r(inc->inc_laddr, sp); 3958 sp = s + strlen(s); 3959 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3960 #ifdef INET6 3961 } else if (inc) { 3962 ip6_sprintf(sp, &inc->inc6_faddr); 3963 sp = s + strlen(s); 3964 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3965 sp = s + strlen(s); 3966 ip6_sprintf(sp, &inc->inc6_laddr); 3967 sp = s + strlen(s); 3968 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3969 } else if (ip6 && th) { 3970 ip6_sprintf(sp, &ip6->ip6_src); 3971 sp = s + strlen(s); 3972 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3973 sp = s + strlen(s); 3974 ip6_sprintf(sp, &ip6->ip6_dst); 3975 sp = s + strlen(s); 3976 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3977 #endif /* INET6 */ 3978 #ifdef INET 3979 } else if (ip && th) { 3980 inet_ntoa_r(ip->ip_src, sp); 3981 sp = s + strlen(s); 3982 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3983 sp = s + strlen(s); 3984 inet_ntoa_r(ip->ip_dst, sp); 3985 sp = s + strlen(s); 3986 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3987 #endif /* INET */ 3988 } else { 3989 free(s, M_TCPLOG); 3990 return (NULL); 3991 } 3992 sp = s + strlen(s); 3993 if (th) 3994 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3995 if (*(s + size - 1) != '\0') 3996 panic("%s: string too long", __func__); 3997 return (s); 3998 } 3999 4000 /* 4001 * A subroutine which makes it easy to track TCP state changes with DTrace. 4002 * This function shouldn't be called for t_state initializations that don't 4003 * correspond to actual TCP state transitions. 4004 */ 4005 void 4006 tcp_state_change(struct tcpcb *tp, int newstate) 4007 { 4008 #if defined(KDTRACE_HOOKS) 4009 int pstate = tp->t_state; 4010 #endif 4011 4012 TCPSTATES_DEC(tp->t_state); 4013 TCPSTATES_INC(newstate); 4014 tp->t_state = newstate; 4015 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 4016 } 4017 4018 /* 4019 * Create an external-format (``xtcpcb'') structure using the information in 4020 * the kernel-format tcpcb structure pointed to by tp. This is done to 4021 * reduce the spew of irrelevant information over this interface, to isolate 4022 * user code from changes in the kernel structure, and potentially to provide 4023 * information-hiding if we decide that some of this information should be 4024 * hidden from users. 4025 */ 4026 void 4027 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 4028 { 4029 struct tcpcb *tp = intotcpcb(inp); 4030 struct tcptw *tw = intotw(inp); 4031 sbintime_t now; 4032 4033 bzero(xt, sizeof(*xt)); 4034 if (inp->inp_flags & INP_TIMEWAIT) { 4035 xt->t_state = TCPS_TIME_WAIT; 4036 xt->xt_encaps_port = tw->t_port; 4037 } else { 4038 xt->t_state = tp->t_state; 4039 xt->t_logstate = tp->t_logstate; 4040 xt->t_flags = tp->t_flags; 4041 xt->t_sndzerowin = tp->t_sndzerowin; 4042 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4043 xt->t_rcvoopack = tp->t_rcvoopack; 4044 xt->t_rcv_wnd = tp->rcv_wnd; 4045 xt->t_snd_wnd = tp->snd_wnd; 4046 xt->t_snd_cwnd = tp->snd_cwnd; 4047 xt->t_snd_ssthresh = tp->snd_ssthresh; 4048 xt->t_dsack_bytes = tp->t_dsack_bytes; 4049 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 4050 xt->t_dsack_pack = tp->t_dsack_pack; 4051 xt->t_maxseg = tp->t_maxseg; 4052 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4053 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4054 4055 now = getsbinuptime(); 4056 #define COPYTIMER(ttt) do { \ 4057 if (callout_active(&tp->t_timers->ttt)) \ 4058 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4059 SBT_1MS; \ 4060 else \ 4061 xt->ttt = 0; \ 4062 } while (0) 4063 COPYTIMER(tt_delack); 4064 COPYTIMER(tt_rexmt); 4065 COPYTIMER(tt_persist); 4066 COPYTIMER(tt_keep); 4067 COPYTIMER(tt_2msl); 4068 #undef COPYTIMER 4069 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4070 4071 xt->xt_encaps_port = tp->t_port; 4072 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4073 TCP_FUNCTION_NAME_LEN_MAX); 4074 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4075 TCP_CA_NAME_MAX); 4076 #ifdef TCP_BLACKBOX 4077 (void)tcp_log_get_id(tp, xt->xt_logid); 4078 #endif 4079 } 4080 4081 xt->xt_len = sizeof(struct xtcpcb); 4082 in_pcbtoxinpcb(inp, &xt->xt_inp); 4083 if (inp->inp_socket == NULL) 4084 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4085 } 4086 4087 void 4088 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4089 { 4090 uint32_t bit, i; 4091 4092 if ((tp == NULL) || 4093 (status > TCP_EI_STATUS_MAX_VALUE) || 4094 (status == 0)) { 4095 /* Invalid */ 4096 return; 4097 } 4098 if (status > (sizeof(uint32_t) * 8)) { 4099 /* Should this be a KASSERT? */ 4100 return; 4101 } 4102 bit = 1U << (status - 1); 4103 if (bit & tp->t_end_info_status) { 4104 /* already logged */ 4105 return; 4106 } 4107 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4108 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4109 tp->t_end_info_bytes[i] = status; 4110 tp->t_end_info_status |= bit; 4111 break; 4112 } 4113 } 4114 } 4115 4116 int 4117 tcp_can_enable_pacing(void) 4118 { 4119 4120 if ((tcp_pacing_limit == -1) || 4121 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4122 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4123 shadow_num_connections = number_of_tcp_connections_pacing; 4124 return (1); 4125 } else { 4126 return (0); 4127 } 4128 } 4129 4130 static uint8_t tcp_pacing_warning = 0; 4131 4132 void 4133 tcp_decrement_paced_conn(void) 4134 { 4135 uint32_t ret; 4136 4137 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4138 shadow_num_connections = number_of_tcp_connections_pacing; 4139 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4140 if (ret == 0) { 4141 if (tcp_pacing_limit != -1) { 4142 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4143 tcp_pacing_limit = 0; 4144 } else if (tcp_pacing_warning == 0) { 4145 printf("Warning pacing count is invalid, invalid decrement\n"); 4146 tcp_pacing_warning = 1; 4147 } 4148 } 4149 } 4150