1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #ifdef INET6 66 #include <sys/domain.h> 67 #endif 68 #include <sys/priv.h> 69 #include <sys/proc.h> 70 #include <sys/sdt.h> 71 #include <sys/socket.h> 72 #include <sys/socketvar.h> 73 #include <sys/protosw.h> 74 #include <sys/random.h> 75 76 #include <vm/uma.h> 77 78 #include <net/route.h> 79 #include <net/route/nhop.h> 80 #include <net/if.h> 81 #include <net/if_var.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_fib.h> 86 #include <netinet/in_kdtrace.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/ip_icmp.h> 92 #include <netinet/ip_var.h> 93 #ifdef INET6 94 #include <netinet/icmp6.h> 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_fib.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet6/scope6_var.h> 100 #include <netinet6/nd6.h> 101 #endif 102 103 #include <netinet/tcp.h> 104 #ifdef INVARIANTS 105 #define TCPSTATES 106 #endif 107 #include <netinet/tcp_fsm.h> 108 #include <netinet/tcp_seq.h> 109 #include <netinet/tcp_timer.h> 110 #include <netinet/tcp_var.h> 111 #include <netinet/tcp_log_buf.h> 112 #include <netinet/tcp_syncache.h> 113 #include <netinet/tcp_hpts.h> 114 #include <netinet/cc/cc.h> 115 #ifdef INET6 116 #include <netinet6/tcp6_var.h> 117 #endif 118 #include <netinet/tcpip.h> 119 #include <netinet/tcp_fastopen.h> 120 #ifdef TCPPCAP 121 #include <netinet/tcp_pcap.h> 122 #endif 123 #ifdef TCPDEBUG 124 #include <netinet/tcp_debug.h> 125 #endif 126 #ifdef INET6 127 #include <netinet6/ip6protosw.h> 128 #endif 129 #ifdef TCP_OFFLOAD 130 #include <netinet/tcp_offload.h> 131 #endif 132 #include <netinet/udp.h> 133 #include <netinet/udp_var.h> 134 135 #include <netipsec/ipsec_support.h> 136 137 #include <machine/in_cksum.h> 138 #include <crypto/siphash/siphash.h> 139 140 #include <security/mac/mac_framework.h> 141 142 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 143 #ifdef INET6 144 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 145 #endif 146 147 #ifdef NETFLIX_EXP_DETECTION 148 /* Sack attack detection thresholds and such */ 149 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 150 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 151 "Sack Attack detection thresholds"); 152 int32_t tcp_force_detection = 0; 153 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 154 CTLFLAG_RW, 155 &tcp_force_detection, 0, 156 "Do we force detection even if the INP has it off?"); 157 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 158 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 159 CTLFLAG_RW, 160 &tcp_sack_to_ack_thresh, 700, 161 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 162 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 163 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 164 CTLFLAG_RW, 165 &tcp_sack_to_move_thresh, 600, 166 "Percentage of sack moves we must see above (10.1 percent is 101)"); 167 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 168 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 169 CTLFLAG_RW, 170 &tcp_restoral_thresh, 550, 171 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 172 int32_t tcp_sad_decay_val = 800; 173 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 174 CTLFLAG_RW, 175 &tcp_sad_decay_val, 800, 176 "The decay percentage (10.1 percent equals 101 )"); 177 int32_t tcp_map_minimum = 500; 178 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 179 CTLFLAG_RW, 180 &tcp_map_minimum, 500, 181 "Number of Map enteries before we start detection"); 182 int32_t tcp_attack_on_turns_on_logging = 0; 183 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 184 CTLFLAG_RW, 185 &tcp_attack_on_turns_on_logging, 0, 186 "When we have a positive hit on attack, do we turn on logging?"); 187 int32_t tcp_sad_pacing_interval = 2000; 188 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 189 CTLFLAG_RW, 190 &tcp_sad_pacing_interval, 2000, 191 "What is the minimum pacing interval for a classified attacker?"); 192 193 int32_t tcp_sad_low_pps = 100; 194 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 195 CTLFLAG_RW, 196 &tcp_sad_low_pps, 100, 197 "What is the input pps that below which we do not decay?"); 198 #endif 199 uint32_t tcp_ack_war_time_window = 1000; 200 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 201 CTLFLAG_RW, 202 &tcp_ack_war_time_window, 1000, 203 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 204 uint32_t tcp_ack_war_cnt = 5; 205 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 206 CTLFLAG_RW, 207 &tcp_ack_war_cnt, 5, 208 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 209 210 struct rwlock tcp_function_lock; 211 212 static int 213 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 214 { 215 int error, new; 216 217 new = V_tcp_mssdflt; 218 error = sysctl_handle_int(oidp, &new, 0, req); 219 if (error == 0 && req->newptr) { 220 if (new < TCP_MINMSS) 221 error = EINVAL; 222 else 223 V_tcp_mssdflt = new; 224 } 225 return (error); 226 } 227 228 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 229 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 230 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 231 "Default TCP Maximum Segment Size"); 232 233 #ifdef INET6 234 static int 235 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 236 { 237 int error, new; 238 239 new = V_tcp_v6mssdflt; 240 error = sysctl_handle_int(oidp, &new, 0, req); 241 if (error == 0 && req->newptr) { 242 if (new < TCP_MINMSS) 243 error = EINVAL; 244 else 245 V_tcp_v6mssdflt = new; 246 } 247 return (error); 248 } 249 250 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 251 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 252 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 253 "Default TCP Maximum Segment Size for IPv6"); 254 #endif /* INET6 */ 255 256 /* 257 * Minimum MSS we accept and use. This prevents DoS attacks where 258 * we are forced to a ridiculous low MSS like 20 and send hundreds 259 * of packets instead of one. The effect scales with the available 260 * bandwidth and quickly saturates the CPU and network interface 261 * with packet generation and sending. Set to zero to disable MINMSS 262 * checking. This setting prevents us from sending too small packets. 263 */ 264 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 265 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 266 &VNET_NAME(tcp_minmss), 0, 267 "Minimum TCP Maximum Segment Size"); 268 269 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 270 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 271 &VNET_NAME(tcp_do_rfc1323), 0, 272 "Enable rfc1323 (high performance TCP) extensions"); 273 274 /* 275 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 276 * Some stacks negotiate TS, but never send them after connection setup. Some 277 * stacks negotiate TS, but don't send them when sending keep-alive segments. 278 * These include modern widely deployed TCP stacks. 279 * Therefore tolerating violations for now... 280 */ 281 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 282 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 283 &VNET_NAME(tcp_tolerate_missing_ts), 0, 284 "Tolerate missing TCP timestamps"); 285 286 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 287 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 288 &VNET_NAME(tcp_ts_offset_per_conn), 0, 289 "Initialize TCP timestamps per connection instead of per host pair"); 290 291 /* How many connections are pacing */ 292 static volatile uint32_t number_of_tcp_connections_pacing = 0; 293 static uint32_t shadow_num_connections = 0; 294 295 static int tcp_pacing_limit = 10000; 296 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 297 &tcp_pacing_limit, 1000, 298 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 299 300 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 301 &shadow_num_connections, 0, "Number of TCP connections being paced"); 302 303 static int tcp_log_debug = 0; 304 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 305 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 306 307 static int tcp_tcbhashsize; 308 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 309 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 310 311 static int do_tcpdrain = 1; 312 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 313 "Enable tcp_drain routine for extra help when low on mbufs"); 314 315 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 316 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 317 318 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 319 #define V_icmp_may_rst VNET(icmp_may_rst) 320 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 321 &VNET_NAME(icmp_may_rst), 0, 322 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 323 324 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 325 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 326 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 327 &VNET_NAME(tcp_isn_reseed_interval), 0, 328 "Seconds between reseeding of ISN secret"); 329 330 static int tcp_soreceive_stream; 331 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 332 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 333 334 VNET_DEFINE(uma_zone_t, sack_hole_zone); 335 #define V_sack_hole_zone VNET(sack_hole_zone) 336 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 337 static int 338 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 339 { 340 int error; 341 uint32_t new; 342 343 new = V_tcp_map_entries_limit; 344 error = sysctl_handle_int(oidp, &new, 0, req); 345 if (error == 0 && req->newptr) { 346 /* only allow "0" and value > minimum */ 347 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 348 error = EINVAL; 349 else 350 V_tcp_map_entries_limit = new; 351 } 352 return (error); 353 } 354 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 355 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 356 &VNET_NAME(tcp_map_entries_limit), 0, 357 &sysctl_net_inet_tcp_map_limit_check, "IU", 358 "Total sendmap entries limit"); 359 360 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 361 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 362 &VNET_NAME(tcp_map_split_limit), 0, 363 "Total sendmap split entries limit"); 364 365 #ifdef TCP_HHOOK 366 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 367 #endif 368 369 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 370 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 371 #define V_ts_offset_secret VNET(ts_offset_secret) 372 373 static int tcp_default_fb_init(struct tcpcb *tp); 374 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 375 static int tcp_default_handoff_ok(struct tcpcb *tp); 376 static struct inpcb *tcp_notify(struct inpcb *, int); 377 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 378 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 379 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 380 const void *ip4hdr, const void *ip6hdr); 381 382 static struct tcp_function_block tcp_def_funcblk = { 383 .tfb_tcp_block_name = "freebsd", 384 .tfb_tcp_output = tcp_default_output, 385 .tfb_tcp_do_segment = tcp_do_segment, 386 .tfb_tcp_ctloutput = tcp_default_ctloutput, 387 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 388 .tfb_tcp_fb_init = tcp_default_fb_init, 389 .tfb_tcp_fb_fini = tcp_default_fb_fini, 390 }; 391 392 static int tcp_fb_cnt = 0; 393 struct tcp_funchead t_functions; 394 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 395 396 void 397 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 398 { 399 TCPSTAT_INC(tcps_dsack_count); 400 tp->t_dsack_pack++; 401 if (tlp == 0) { 402 if (SEQ_GT(end, start)) { 403 tp->t_dsack_bytes += (end - start); 404 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 405 } else { 406 tp->t_dsack_tlp_bytes += (start - end); 407 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 408 } 409 } else { 410 if (SEQ_GT(end, start)) { 411 tp->t_dsack_bytes += (end - start); 412 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 413 } else { 414 tp->t_dsack_tlp_bytes += (start - end); 415 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 416 } 417 } 418 } 419 420 static struct tcp_function_block * 421 find_tcp_functions_locked(struct tcp_function_set *fs) 422 { 423 struct tcp_function *f; 424 struct tcp_function_block *blk=NULL; 425 426 TAILQ_FOREACH(f, &t_functions, tf_next) { 427 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 428 blk = f->tf_fb; 429 break; 430 } 431 } 432 return(blk); 433 } 434 435 static struct tcp_function_block * 436 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 437 { 438 struct tcp_function_block *rblk=NULL; 439 struct tcp_function *f; 440 441 TAILQ_FOREACH(f, &t_functions, tf_next) { 442 if (f->tf_fb == blk) { 443 rblk = blk; 444 if (s) { 445 *s = f; 446 } 447 break; 448 } 449 } 450 return (rblk); 451 } 452 453 struct tcp_function_block * 454 find_and_ref_tcp_functions(struct tcp_function_set *fs) 455 { 456 struct tcp_function_block *blk; 457 458 rw_rlock(&tcp_function_lock); 459 blk = find_tcp_functions_locked(fs); 460 if (blk) 461 refcount_acquire(&blk->tfb_refcnt); 462 rw_runlock(&tcp_function_lock); 463 return(blk); 464 } 465 466 struct tcp_function_block * 467 find_and_ref_tcp_fb(struct tcp_function_block *blk) 468 { 469 struct tcp_function_block *rblk; 470 471 rw_rlock(&tcp_function_lock); 472 rblk = find_tcp_fb_locked(blk, NULL); 473 if (rblk) 474 refcount_acquire(&rblk->tfb_refcnt); 475 rw_runlock(&tcp_function_lock); 476 return(rblk); 477 } 478 479 /* Find a matching alias for the given tcp_function_block. */ 480 int 481 find_tcp_function_alias(struct tcp_function_block *blk, 482 struct tcp_function_set *fs) 483 { 484 struct tcp_function *f; 485 int found; 486 487 found = 0; 488 rw_rlock(&tcp_function_lock); 489 TAILQ_FOREACH(f, &t_functions, tf_next) { 490 if ((f->tf_fb == blk) && 491 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 492 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 493 /* Matching function block with different name. */ 494 strncpy(fs->function_set_name, f->tf_name, 495 TCP_FUNCTION_NAME_LEN_MAX); 496 found = 1; 497 break; 498 } 499 } 500 /* Null terminate the string appropriately. */ 501 if (found) { 502 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 503 } else { 504 fs->function_set_name[0] = '\0'; 505 } 506 rw_runlock(&tcp_function_lock); 507 return (found); 508 } 509 510 static struct tcp_function_block * 511 find_and_ref_tcp_default_fb(void) 512 { 513 struct tcp_function_block *rblk; 514 515 rw_rlock(&tcp_function_lock); 516 rblk = tcp_func_set_ptr; 517 refcount_acquire(&rblk->tfb_refcnt); 518 rw_runlock(&tcp_function_lock); 519 return (rblk); 520 } 521 522 void 523 tcp_switch_back_to_default(struct tcpcb *tp) 524 { 525 struct tcp_function_block *tfb; 526 527 KASSERT(tp->t_fb != &tcp_def_funcblk, 528 ("%s: called by the built-in default stack", __func__)); 529 530 /* 531 * Release the old stack. This function will either find a new one 532 * or panic. 533 */ 534 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 535 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 536 refcount_release(&tp->t_fb->tfb_refcnt); 537 538 /* 539 * Now, we'll find a new function block to use. 540 * Start by trying the current user-selected 541 * default, unless this stack is the user-selected 542 * default. 543 */ 544 tfb = find_and_ref_tcp_default_fb(); 545 if (tfb == tp->t_fb) { 546 refcount_release(&tfb->tfb_refcnt); 547 tfb = NULL; 548 } 549 /* Does the stack accept this connection? */ 550 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 551 (*tfb->tfb_tcp_handoff_ok)(tp)) { 552 refcount_release(&tfb->tfb_refcnt); 553 tfb = NULL; 554 } 555 /* Try to use that stack. */ 556 if (tfb != NULL) { 557 /* Initialize the new stack. If it succeeds, we are done. */ 558 tp->t_fb = tfb; 559 if (tp->t_fb->tfb_tcp_fb_init == NULL || 560 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 561 return; 562 563 /* 564 * Initialization failed. Release the reference count on 565 * the stack. 566 */ 567 refcount_release(&tfb->tfb_refcnt); 568 } 569 570 /* 571 * If that wasn't feasible, use the built-in default 572 * stack which is not allowed to reject anyone. 573 */ 574 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 575 if (tfb == NULL) { 576 /* there always should be a default */ 577 panic("Can't refer to tcp_def_funcblk"); 578 } 579 if (tfb->tfb_tcp_handoff_ok != NULL) { 580 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 581 /* The default stack cannot say no */ 582 panic("Default stack rejects a new session?"); 583 } 584 } 585 tp->t_fb = tfb; 586 if (tp->t_fb->tfb_tcp_fb_init != NULL && 587 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 588 /* The default stack cannot fail */ 589 panic("Default stack initialization failed"); 590 } 591 } 592 593 static bool 594 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 595 const struct sockaddr *sa, void *ctx) 596 { 597 struct ip *iph; 598 #ifdef INET6 599 struct ip6_hdr *ip6; 600 #endif 601 struct udphdr *uh; 602 struct tcphdr *th; 603 int thlen; 604 uint16_t port; 605 606 TCPSTAT_INC(tcps_tunneled_pkts); 607 if ((m->m_flags & M_PKTHDR) == 0) { 608 /* Can't handle one that is not a pkt hdr */ 609 TCPSTAT_INC(tcps_tunneled_errs); 610 goto out; 611 } 612 thlen = sizeof(struct tcphdr); 613 if (m->m_len < off + sizeof(struct udphdr) + thlen && 614 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 615 TCPSTAT_INC(tcps_tunneled_errs); 616 goto out; 617 } 618 iph = mtod(m, struct ip *); 619 uh = (struct udphdr *)((caddr_t)iph + off); 620 th = (struct tcphdr *)(uh + 1); 621 thlen = th->th_off << 2; 622 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 623 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 624 if (m == NULL) { 625 TCPSTAT_INC(tcps_tunneled_errs); 626 goto out; 627 } else { 628 iph = mtod(m, struct ip *); 629 uh = (struct udphdr *)((caddr_t)iph + off); 630 th = (struct tcphdr *)(uh + 1); 631 } 632 } 633 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 634 bcopy(th, uh, m->m_len - off); 635 m->m_len -= sizeof(struct udphdr); 636 m->m_pkthdr.len -= sizeof(struct udphdr); 637 /* 638 * We use the same algorithm for 639 * both UDP and TCP for c-sum. So 640 * the code in tcp_input will skip 641 * the checksum. So we do nothing 642 * with the flag (m->m_pkthdr.csum_flags). 643 */ 644 switch (iph->ip_v) { 645 #ifdef INET 646 case IPVERSION: 647 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 648 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 649 break; 650 #endif 651 #ifdef INET6 652 case IPV6_VERSION >> 4: 653 ip6 = mtod(m, struct ip6_hdr *); 654 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 655 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 656 break; 657 #endif 658 default: 659 goto out; 660 break; 661 } 662 return (true); 663 out: 664 m_freem(m); 665 666 return (true); 667 } 668 669 static int 670 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 671 { 672 int error=ENOENT; 673 struct tcp_function_set fs; 674 struct tcp_function_block *blk; 675 676 memset(&fs, 0, sizeof(fs)); 677 rw_rlock(&tcp_function_lock); 678 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 679 if (blk) { 680 /* Found him */ 681 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 682 fs.pcbcnt = blk->tfb_refcnt; 683 } 684 rw_runlock(&tcp_function_lock); 685 error = sysctl_handle_string(oidp, fs.function_set_name, 686 sizeof(fs.function_set_name), req); 687 688 /* Check for error or no change */ 689 if (error != 0 || req->newptr == NULL) 690 return(error); 691 692 rw_wlock(&tcp_function_lock); 693 blk = find_tcp_functions_locked(&fs); 694 if ((blk == NULL) || 695 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 696 error = ENOENT; 697 goto done; 698 } 699 tcp_func_set_ptr = blk; 700 done: 701 rw_wunlock(&tcp_function_lock); 702 return (error); 703 } 704 705 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 706 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 707 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 708 "Set/get the default TCP functions"); 709 710 static int 711 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 712 { 713 int error, cnt, linesz; 714 struct tcp_function *f; 715 char *buffer, *cp; 716 size_t bufsz, outsz; 717 bool alias; 718 719 cnt = 0; 720 rw_rlock(&tcp_function_lock); 721 TAILQ_FOREACH(f, &t_functions, tf_next) { 722 cnt++; 723 } 724 rw_runlock(&tcp_function_lock); 725 726 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 727 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 728 729 error = 0; 730 cp = buffer; 731 732 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 733 "Alias", "PCB count"); 734 cp += linesz; 735 bufsz -= linesz; 736 outsz = linesz; 737 738 rw_rlock(&tcp_function_lock); 739 TAILQ_FOREACH(f, &t_functions, tf_next) { 740 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 741 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 742 f->tf_fb->tfb_tcp_block_name, 743 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 744 alias ? f->tf_name : "-", 745 f->tf_fb->tfb_refcnt); 746 if (linesz >= bufsz) { 747 error = EOVERFLOW; 748 break; 749 } 750 cp += linesz; 751 bufsz -= linesz; 752 outsz += linesz; 753 } 754 rw_runlock(&tcp_function_lock); 755 if (error == 0) 756 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 757 free(buffer, M_TEMP); 758 return (error); 759 } 760 761 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 762 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 763 NULL, 0, sysctl_net_inet_list_available, "A", 764 "list available TCP Function sets"); 765 766 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 767 768 #ifdef INET 769 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 770 #define V_udp4_tun_socket VNET(udp4_tun_socket) 771 #endif 772 #ifdef INET6 773 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 774 #define V_udp6_tun_socket VNET(udp6_tun_socket) 775 #endif 776 777 static void 778 tcp_over_udp_stop(void) 779 { 780 /* 781 * This function assumes sysctl caller holds inp_rinfo_lock() 782 * for writing! 783 */ 784 #ifdef INET 785 if (V_udp4_tun_socket != NULL) { 786 soclose(V_udp4_tun_socket); 787 V_udp4_tun_socket = NULL; 788 } 789 #endif 790 #ifdef INET6 791 if (V_udp6_tun_socket != NULL) { 792 soclose(V_udp6_tun_socket); 793 V_udp6_tun_socket = NULL; 794 } 795 #endif 796 } 797 798 static int 799 tcp_over_udp_start(void) 800 { 801 uint16_t port; 802 int ret; 803 #ifdef INET 804 struct sockaddr_in sin; 805 #endif 806 #ifdef INET6 807 struct sockaddr_in6 sin6; 808 #endif 809 /* 810 * This function assumes sysctl caller holds inp_info_rlock() 811 * for writing! 812 */ 813 port = V_tcp_udp_tunneling_port; 814 if (ntohs(port) == 0) { 815 /* Must have a port set */ 816 return (EINVAL); 817 } 818 #ifdef INET 819 if (V_udp4_tun_socket != NULL) { 820 /* Already running -- must stop first */ 821 return (EALREADY); 822 } 823 #endif 824 #ifdef INET6 825 if (V_udp6_tun_socket != NULL) { 826 /* Already running -- must stop first */ 827 return (EALREADY); 828 } 829 #endif 830 #ifdef INET 831 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 832 SOCK_DGRAM, IPPROTO_UDP, 833 curthread->td_ucred, curthread))) { 834 tcp_over_udp_stop(); 835 return (ret); 836 } 837 /* Call the special UDP hook. */ 838 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 839 tcp_recv_udp_tunneled_packet, 840 tcp_ctlinput_viaudp, 841 NULL))) { 842 tcp_over_udp_stop(); 843 return (ret); 844 } 845 /* Ok, we have a socket, bind it to the port. */ 846 memset(&sin, 0, sizeof(struct sockaddr_in)); 847 sin.sin_len = sizeof(struct sockaddr_in); 848 sin.sin_family = AF_INET; 849 sin.sin_port = htons(port); 850 if ((ret = sobind(V_udp4_tun_socket, 851 (struct sockaddr *)&sin, curthread))) { 852 tcp_over_udp_stop(); 853 return (ret); 854 } 855 #endif 856 #ifdef INET6 857 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 858 SOCK_DGRAM, IPPROTO_UDP, 859 curthread->td_ucred, curthread))) { 860 tcp_over_udp_stop(); 861 return (ret); 862 } 863 /* Call the special UDP hook. */ 864 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 865 tcp_recv_udp_tunneled_packet, 866 tcp6_ctlinput_viaudp, 867 NULL))) { 868 tcp_over_udp_stop(); 869 return (ret); 870 } 871 /* Ok, we have a socket, bind it to the port. */ 872 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 873 sin6.sin6_len = sizeof(struct sockaddr_in6); 874 sin6.sin6_family = AF_INET6; 875 sin6.sin6_port = htons(port); 876 if ((ret = sobind(V_udp6_tun_socket, 877 (struct sockaddr *)&sin6, curthread))) { 878 tcp_over_udp_stop(); 879 return (ret); 880 } 881 #endif 882 return (0); 883 } 884 885 static int 886 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 887 { 888 int error; 889 uint32_t old, new; 890 891 old = V_tcp_udp_tunneling_port; 892 new = old; 893 error = sysctl_handle_int(oidp, &new, 0, req); 894 if ((error == 0) && 895 (req->newptr != NULL)) { 896 if ((new < TCP_TUNNELING_PORT_MIN) || 897 (new > TCP_TUNNELING_PORT_MAX)) { 898 error = EINVAL; 899 } else { 900 V_tcp_udp_tunneling_port = new; 901 if (old != 0) { 902 tcp_over_udp_stop(); 903 } 904 if (new != 0) { 905 error = tcp_over_udp_start(); 906 } 907 } 908 } 909 return (error); 910 } 911 912 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 913 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 914 &VNET_NAME(tcp_udp_tunneling_port), 915 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 916 "Tunneling port for tcp over udp"); 917 918 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 919 920 static int 921 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 922 { 923 int error, new; 924 925 new = V_tcp_udp_tunneling_overhead; 926 error = sysctl_handle_int(oidp, &new, 0, req); 927 if (error == 0 && req->newptr) { 928 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 929 (new > TCP_TUNNELING_OVERHEAD_MAX)) 930 error = EINVAL; 931 else 932 V_tcp_udp_tunneling_overhead = new; 933 } 934 return (error); 935 } 936 937 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 938 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 939 &VNET_NAME(tcp_udp_tunneling_overhead), 940 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 941 "MSS reduction when using tcp over udp"); 942 943 /* 944 * Exports one (struct tcp_function_info) for each alias/name. 945 */ 946 static int 947 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 948 { 949 int cnt, error; 950 struct tcp_function *f; 951 struct tcp_function_info tfi; 952 953 /* 954 * We don't allow writes. 955 */ 956 if (req->newptr != NULL) 957 return (EINVAL); 958 959 /* 960 * Wire the old buffer so we can directly copy the functions to 961 * user space without dropping the lock. 962 */ 963 if (req->oldptr != NULL) { 964 error = sysctl_wire_old_buffer(req, 0); 965 if (error) 966 return (error); 967 } 968 969 /* 970 * Walk the list and copy out matching entries. If INVARIANTS 971 * is compiled in, also walk the list to verify the length of 972 * the list matches what we have recorded. 973 */ 974 rw_rlock(&tcp_function_lock); 975 976 cnt = 0; 977 #ifndef INVARIANTS 978 if (req->oldptr == NULL) { 979 cnt = tcp_fb_cnt; 980 goto skip_loop; 981 } 982 #endif 983 TAILQ_FOREACH(f, &t_functions, tf_next) { 984 #ifdef INVARIANTS 985 cnt++; 986 #endif 987 if (req->oldptr != NULL) { 988 bzero(&tfi, sizeof(tfi)); 989 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 990 tfi.tfi_id = f->tf_fb->tfb_id; 991 (void)strlcpy(tfi.tfi_alias, f->tf_name, 992 sizeof(tfi.tfi_alias)); 993 (void)strlcpy(tfi.tfi_name, 994 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 995 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 996 /* 997 * Don't stop on error, as that is the 998 * mechanism we use to accumulate length 999 * information if the buffer was too short. 1000 */ 1001 } 1002 } 1003 KASSERT(cnt == tcp_fb_cnt, 1004 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1005 #ifndef INVARIANTS 1006 skip_loop: 1007 #endif 1008 rw_runlock(&tcp_function_lock); 1009 if (req->oldptr == NULL) 1010 error = SYSCTL_OUT(req, NULL, 1011 (cnt + 1) * sizeof(struct tcp_function_info)); 1012 1013 return (error); 1014 } 1015 1016 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1017 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1018 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1019 "List TCP function block name-to-ID mappings"); 1020 1021 /* 1022 * tfb_tcp_handoff_ok() function for the default stack. 1023 * Note that we'll basically try to take all comers. 1024 */ 1025 static int 1026 tcp_default_handoff_ok(struct tcpcb *tp) 1027 { 1028 1029 return (0); 1030 } 1031 1032 /* 1033 * tfb_tcp_fb_init() function for the default stack. 1034 * 1035 * This handles making sure we have appropriate timers set if you are 1036 * transitioning a socket that has some amount of setup done. 1037 * 1038 * The init() fuction from the default can *never* return non-zero i.e. 1039 * it is required to always succeed since it is the stack of last resort! 1040 */ 1041 static int 1042 tcp_default_fb_init(struct tcpcb *tp) 1043 { 1044 1045 struct socket *so; 1046 1047 INP_WLOCK_ASSERT(tp->t_inpcb); 1048 1049 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1050 ("%s: connection %p in unexpected state %d", __func__, tp, 1051 tp->t_state)); 1052 1053 /* 1054 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1055 * know what to do for unexpected states (which includes TIME_WAIT). 1056 */ 1057 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1058 return (0); 1059 1060 /* 1061 * Make sure some kind of transmission timer is set if there is 1062 * outstanding data. 1063 */ 1064 so = tp->t_inpcb->inp_socket; 1065 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1066 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1067 tcp_timer_active(tp, TT_PERSIST))) { 1068 /* 1069 * If the session has established and it looks like it should 1070 * be in the persist state, set the persist timer. Otherwise, 1071 * set the retransmit timer. 1072 */ 1073 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1074 (int32_t)(tp->snd_nxt - tp->snd_una) < 1075 (int32_t)sbavail(&so->so_snd)) 1076 tcp_setpersist(tp); 1077 else 1078 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1079 } 1080 1081 /* All non-embryonic sessions get a keepalive timer. */ 1082 if (!tcp_timer_active(tp, TT_KEEP)) 1083 tcp_timer_activate(tp, TT_KEEP, 1084 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1085 TP_KEEPINIT(tp)); 1086 1087 /* 1088 * Make sure critical variables are initialized 1089 * if transitioning while in Recovery. 1090 */ 1091 if IN_FASTRECOVERY(tp->t_flags) { 1092 if (tp->sackhint.recover_fs == 0) 1093 tp->sackhint.recover_fs = max(1, 1094 tp->snd_nxt - tp->snd_una); 1095 } 1096 1097 return (0); 1098 } 1099 1100 /* 1101 * tfb_tcp_fb_fini() function for the default stack. 1102 * 1103 * This changes state as necessary (or prudent) to prepare for another stack 1104 * to assume responsibility for the connection. 1105 */ 1106 static void 1107 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1108 { 1109 1110 INP_WLOCK_ASSERT(tp->t_inpcb); 1111 return; 1112 } 1113 1114 /* 1115 * Target size of TCP PCB hash tables. Must be a power of two. 1116 * 1117 * Note that this can be overridden by the kernel environment 1118 * variable net.inet.tcp.tcbhashsize 1119 */ 1120 #ifndef TCBHASHSIZE 1121 #define TCBHASHSIZE 0 1122 #endif 1123 1124 /* 1125 * XXX 1126 * Callouts should be moved into struct tcp directly. They are currently 1127 * separate because the tcpcb structure is exported to userland for sysctl 1128 * parsing purposes, which do not know about callouts. 1129 */ 1130 struct tcpcb_mem { 1131 struct tcpcb tcb; 1132 struct tcp_timer tt; 1133 struct cc_var ccv; 1134 #ifdef TCP_HHOOK 1135 struct osd osd; 1136 #endif 1137 }; 1138 1139 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1140 #define V_tcpcb_zone VNET(tcpcb_zone) 1141 1142 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1143 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1144 1145 static struct mtx isn_mtx; 1146 1147 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1148 #define ISN_LOCK() mtx_lock(&isn_mtx) 1149 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1150 1151 INPCBSTORAGE_DEFINE(tcpcbstor, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1152 1153 /* 1154 * Take a value and get the next power of 2 that doesn't overflow. 1155 * Used to size the tcp_inpcb hash buckets. 1156 */ 1157 static int 1158 maketcp_hashsize(int size) 1159 { 1160 int hashsize; 1161 1162 /* 1163 * auto tune. 1164 * get the next power of 2 higher than maxsockets. 1165 */ 1166 hashsize = 1 << fls(size); 1167 /* catch overflow, and just go one power of 2 smaller */ 1168 if (hashsize < size) { 1169 hashsize = 1 << (fls(size) - 1); 1170 } 1171 return (hashsize); 1172 } 1173 1174 static volatile int next_tcp_stack_id = 1; 1175 1176 /* 1177 * Register a TCP function block with the name provided in the names 1178 * array. (Note that this function does NOT automatically register 1179 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1180 * explicitly include blk->tfb_tcp_block_name in the list of names if 1181 * you wish to register the stack with that name.) 1182 * 1183 * Either all name registrations will succeed or all will fail. If 1184 * a name registration fails, the function will update the num_names 1185 * argument to point to the array index of the name that encountered 1186 * the failure. 1187 * 1188 * Returns 0 on success, or an error code on failure. 1189 */ 1190 int 1191 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1192 const char *names[], int *num_names) 1193 { 1194 struct tcp_function *n; 1195 struct tcp_function_set fs; 1196 int error, i; 1197 1198 KASSERT(names != NULL && *num_names > 0, 1199 ("%s: Called with 0-length name list", __func__)); 1200 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1201 KASSERT(rw_initialized(&tcp_function_lock), 1202 ("%s: called too early", __func__)); 1203 1204 if ((blk->tfb_tcp_output == NULL) || 1205 (blk->tfb_tcp_do_segment == NULL) || 1206 (blk->tfb_tcp_ctloutput == NULL) || 1207 (strlen(blk->tfb_tcp_block_name) == 0)) { 1208 /* 1209 * These functions are required and you 1210 * need a name. 1211 */ 1212 *num_names = 0; 1213 return (EINVAL); 1214 } 1215 if (blk->tfb_tcp_timer_stop_all || 1216 blk->tfb_tcp_timer_activate || 1217 blk->tfb_tcp_timer_active || 1218 blk->tfb_tcp_timer_stop) { 1219 /* 1220 * If you define one timer function you 1221 * must have them all. 1222 */ 1223 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1224 (blk->tfb_tcp_timer_activate == NULL) || 1225 (blk->tfb_tcp_timer_active == NULL) || 1226 (blk->tfb_tcp_timer_stop == NULL)) { 1227 *num_names = 0; 1228 return (EINVAL); 1229 } 1230 } 1231 1232 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1233 *num_names = 0; 1234 return (EINVAL); 1235 } 1236 1237 refcount_init(&blk->tfb_refcnt, 0); 1238 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1239 for (i = 0; i < *num_names; i++) { 1240 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1241 if (n == NULL) { 1242 error = ENOMEM; 1243 goto cleanup; 1244 } 1245 n->tf_fb = blk; 1246 1247 (void)strlcpy(fs.function_set_name, names[i], 1248 sizeof(fs.function_set_name)); 1249 rw_wlock(&tcp_function_lock); 1250 if (find_tcp_functions_locked(&fs) != NULL) { 1251 /* Duplicate name space not allowed */ 1252 rw_wunlock(&tcp_function_lock); 1253 free(n, M_TCPFUNCTIONS); 1254 error = EALREADY; 1255 goto cleanup; 1256 } 1257 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1258 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1259 tcp_fb_cnt++; 1260 rw_wunlock(&tcp_function_lock); 1261 } 1262 return(0); 1263 1264 cleanup: 1265 /* 1266 * Deregister the names we just added. Because registration failed 1267 * for names[i], we don't need to deregister that name. 1268 */ 1269 *num_names = i; 1270 rw_wlock(&tcp_function_lock); 1271 while (--i >= 0) { 1272 TAILQ_FOREACH(n, &t_functions, tf_next) { 1273 if (!strncmp(n->tf_name, names[i], 1274 TCP_FUNCTION_NAME_LEN_MAX)) { 1275 TAILQ_REMOVE(&t_functions, n, tf_next); 1276 tcp_fb_cnt--; 1277 n->tf_fb = NULL; 1278 free(n, M_TCPFUNCTIONS); 1279 break; 1280 } 1281 } 1282 } 1283 rw_wunlock(&tcp_function_lock); 1284 return (error); 1285 } 1286 1287 /* 1288 * Register a TCP function block using the name provided in the name 1289 * argument. 1290 * 1291 * Returns 0 on success, or an error code on failure. 1292 */ 1293 int 1294 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1295 int wait) 1296 { 1297 const char *name_list[1]; 1298 int num_names, rv; 1299 1300 num_names = 1; 1301 if (name != NULL) 1302 name_list[0] = name; 1303 else 1304 name_list[0] = blk->tfb_tcp_block_name; 1305 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1306 return (rv); 1307 } 1308 1309 /* 1310 * Register a TCP function block using the name defined in 1311 * blk->tfb_tcp_block_name. 1312 * 1313 * Returns 0 on success, or an error code on failure. 1314 */ 1315 int 1316 register_tcp_functions(struct tcp_function_block *blk, int wait) 1317 { 1318 1319 return (register_tcp_functions_as_name(blk, NULL, wait)); 1320 } 1321 1322 /* 1323 * Deregister all names associated with a function block. This 1324 * functionally removes the function block from use within the system. 1325 * 1326 * When called with a true quiesce argument, mark the function block 1327 * as being removed so no more stacks will use it and determine 1328 * whether the removal would succeed. 1329 * 1330 * When called with a false quiesce argument, actually attempt the 1331 * removal. 1332 * 1333 * When called with a force argument, attempt to switch all TCBs to 1334 * use the default stack instead of returning EBUSY. 1335 * 1336 * Returns 0 on success (or if the removal would succeed, or an error 1337 * code on failure. 1338 */ 1339 int 1340 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1341 bool force) 1342 { 1343 struct tcp_function *f; 1344 1345 if (blk == &tcp_def_funcblk) { 1346 /* You can't un-register the default */ 1347 return (EPERM); 1348 } 1349 rw_wlock(&tcp_function_lock); 1350 if (blk == tcp_func_set_ptr) { 1351 /* You can't free the current default */ 1352 rw_wunlock(&tcp_function_lock); 1353 return (EBUSY); 1354 } 1355 /* Mark the block so no more stacks can use it. */ 1356 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1357 /* 1358 * If TCBs are still attached to the stack, attempt to switch them 1359 * to the default stack. 1360 */ 1361 if (force && blk->tfb_refcnt) { 1362 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1363 INPLOOKUP_WLOCKPCB); 1364 struct inpcb *inp; 1365 struct tcpcb *tp; 1366 VNET_ITERATOR_DECL(vnet_iter); 1367 1368 rw_wunlock(&tcp_function_lock); 1369 1370 VNET_LIST_RLOCK(); 1371 VNET_FOREACH(vnet_iter) { 1372 CURVNET_SET(vnet_iter); 1373 while ((inp = inp_next(&inpi)) != NULL) { 1374 if (inp->inp_flags & INP_TIMEWAIT) 1375 continue; 1376 tp = intotcpcb(inp); 1377 if (tp == NULL || tp->t_fb != blk) 1378 continue; 1379 tcp_switch_back_to_default(tp); 1380 } 1381 CURVNET_RESTORE(); 1382 } 1383 VNET_LIST_RUNLOCK(); 1384 1385 rw_wlock(&tcp_function_lock); 1386 } 1387 if (blk->tfb_refcnt) { 1388 /* TCBs still attached. */ 1389 rw_wunlock(&tcp_function_lock); 1390 return (EBUSY); 1391 } 1392 if (quiesce) { 1393 /* Skip removal. */ 1394 rw_wunlock(&tcp_function_lock); 1395 return (0); 1396 } 1397 /* Remove any function names that map to this function block. */ 1398 while (find_tcp_fb_locked(blk, &f) != NULL) { 1399 TAILQ_REMOVE(&t_functions, f, tf_next); 1400 tcp_fb_cnt--; 1401 f->tf_fb = NULL; 1402 free(f, M_TCPFUNCTIONS); 1403 } 1404 rw_wunlock(&tcp_function_lock); 1405 return (0); 1406 } 1407 1408 static void 1409 tcp_vnet_init(void *arg __unused) 1410 { 1411 1412 #ifdef TCP_HHOOK 1413 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1414 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1415 printf("%s: WARNING: unable to register helper hook\n", __func__); 1416 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1417 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1418 printf("%s: WARNING: unable to register helper hook\n", __func__); 1419 #endif 1420 #ifdef STATS 1421 if (tcp_stats_init()) 1422 printf("%s: WARNING: unable to initialise TCP stats\n", 1423 __func__); 1424 #endif 1425 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1426 tcp_tcbhashsize); 1427 1428 /* 1429 * These have to be type stable for the benefit of the timers. 1430 */ 1431 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1432 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1433 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1434 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1435 1436 tcp_tw_init(); 1437 syncache_init(); 1438 tcp_hc_init(); 1439 1440 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1441 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1442 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1443 1444 tcp_fastopen_init(); 1445 1446 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1447 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1448 1449 V_tcp_msl = TCPTV_MSL; 1450 } 1451 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1452 tcp_vnet_init, NULL); 1453 1454 static void 1455 tcp_init(void *arg __unused) 1456 { 1457 const char *tcbhash_tuneable; 1458 int hashsize; 1459 1460 tcp_reass_global_init(); 1461 1462 /* XXX virtualize those below? */ 1463 tcp_delacktime = TCPTV_DELACK; 1464 tcp_keepinit = TCPTV_KEEP_INIT; 1465 tcp_keepidle = TCPTV_KEEP_IDLE; 1466 tcp_keepintvl = TCPTV_KEEPINTVL; 1467 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1468 tcp_rexmit_initial = TCPTV_RTOBASE; 1469 if (tcp_rexmit_initial < 1) 1470 tcp_rexmit_initial = 1; 1471 tcp_rexmit_min = TCPTV_MIN; 1472 if (tcp_rexmit_min < 1) 1473 tcp_rexmit_min = 1; 1474 tcp_persmin = TCPTV_PERSMIN; 1475 tcp_persmax = TCPTV_PERSMAX; 1476 tcp_rexmit_slop = TCPTV_CPU_VAR; 1477 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1478 1479 /* Setup the tcp function block list */ 1480 TAILQ_INIT(&t_functions); 1481 rw_init(&tcp_function_lock, "tcp_func_lock"); 1482 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1483 #ifdef TCP_BLACKBOX 1484 /* Initialize the TCP logging data. */ 1485 tcp_log_init(); 1486 #endif 1487 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1488 1489 if (tcp_soreceive_stream) { 1490 #ifdef INET 1491 tcp_usrreqs.pru_soreceive = soreceive_stream; 1492 #endif 1493 #ifdef INET6 1494 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1495 #endif /* INET6 */ 1496 } 1497 1498 #ifdef INET6 1499 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1500 #else /* INET6 */ 1501 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1502 #endif /* INET6 */ 1503 if (max_protohdr < TCP_MINPROTOHDR) 1504 max_protohdr = TCP_MINPROTOHDR; 1505 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1506 panic("tcp_init"); 1507 #undef TCP_MINPROTOHDR 1508 1509 ISN_LOCK_INIT(); 1510 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1511 SHUTDOWN_PRI_DEFAULT); 1512 1513 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1514 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1515 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1516 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1517 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1518 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1519 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1520 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1521 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1522 #ifdef TCPPCAP 1523 tcp_pcap_init(); 1524 #endif 1525 1526 hashsize = TCBHASHSIZE; 1527 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1528 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1529 if (hashsize == 0) { 1530 /* 1531 * Auto tune the hash size based on maxsockets. 1532 * A perfect hash would have a 1:1 mapping 1533 * (hashsize = maxsockets) however it's been 1534 * suggested that O(2) average is better. 1535 */ 1536 hashsize = maketcp_hashsize(maxsockets / 4); 1537 /* 1538 * Our historical default is 512, 1539 * do not autotune lower than this. 1540 */ 1541 if (hashsize < 512) 1542 hashsize = 512; 1543 if (bootverbose) 1544 printf("%s: %s auto tuned to %d\n", __func__, 1545 tcbhash_tuneable, hashsize); 1546 } 1547 /* 1548 * We require a hashsize to be a power of two. 1549 * Previously if it was not a power of two we would just reset it 1550 * back to 512, which could be a nasty surprise if you did not notice 1551 * the error message. 1552 * Instead what we do is clip it to the closest power of two lower 1553 * than the specified hash value. 1554 */ 1555 if (!powerof2(hashsize)) { 1556 int oldhashsize = hashsize; 1557 1558 hashsize = maketcp_hashsize(hashsize); 1559 /* prevent absurdly low value */ 1560 if (hashsize < 16) 1561 hashsize = 16; 1562 printf("%s: WARNING: TCB hash size not a power of 2, " 1563 "clipped from %d to %d.\n", __func__, oldhashsize, 1564 hashsize); 1565 } 1566 tcp_tcbhashsize = hashsize; 1567 } 1568 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1569 1570 #ifdef VIMAGE 1571 static void 1572 tcp_destroy(void *unused __unused) 1573 { 1574 int n; 1575 #ifdef TCP_HHOOK 1576 int error; 1577 #endif 1578 1579 /* 1580 * All our processes are gone, all our sockets should be cleaned 1581 * up, which means, we should be past the tcp_discardcb() calls. 1582 * Sleep to let all tcpcb timers really disappear and cleanup. 1583 */ 1584 for (;;) { 1585 INP_INFO_WLOCK(&V_tcbinfo); 1586 n = V_tcbinfo.ipi_count; 1587 INP_INFO_WUNLOCK(&V_tcbinfo); 1588 if (n == 0) 1589 break; 1590 pause("tcpdes", hz / 10); 1591 } 1592 tcp_hc_destroy(); 1593 syncache_destroy(); 1594 tcp_tw_destroy(); 1595 in_pcbinfo_destroy(&V_tcbinfo); 1596 /* tcp_discardcb() clears the sack_holes up. */ 1597 uma_zdestroy(V_sack_hole_zone); 1598 uma_zdestroy(V_tcpcb_zone); 1599 1600 /* 1601 * Cannot free the zone until all tcpcbs are released as we attach 1602 * the allocations to them. 1603 */ 1604 tcp_fastopen_destroy(); 1605 1606 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1607 VNET_PCPUSTAT_FREE(tcpstat); 1608 1609 #ifdef TCP_HHOOK 1610 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1611 if (error != 0) { 1612 printf("%s: WARNING: unable to deregister helper hook " 1613 "type=%d, id=%d: error %d returned\n", __func__, 1614 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1615 } 1616 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1617 if (error != 0) { 1618 printf("%s: WARNING: unable to deregister helper hook " 1619 "type=%d, id=%d: error %d returned\n", __func__, 1620 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1621 } 1622 #endif 1623 } 1624 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1625 #endif 1626 1627 void 1628 tcp_fini(void *xtp) 1629 { 1630 1631 } 1632 1633 /* 1634 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1635 * tcp_template used to store this data in mbufs, but we now recopy it out 1636 * of the tcpcb each time to conserve mbufs. 1637 */ 1638 void 1639 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1640 { 1641 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1642 1643 INP_WLOCK_ASSERT(inp); 1644 1645 #ifdef INET6 1646 if ((inp->inp_vflag & INP_IPV6) != 0) { 1647 struct ip6_hdr *ip6; 1648 1649 ip6 = (struct ip6_hdr *)ip_ptr; 1650 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1651 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1652 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1653 (IPV6_VERSION & IPV6_VERSION_MASK); 1654 if (port == 0) 1655 ip6->ip6_nxt = IPPROTO_TCP; 1656 else 1657 ip6->ip6_nxt = IPPROTO_UDP; 1658 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1659 ip6->ip6_src = inp->in6p_laddr; 1660 ip6->ip6_dst = inp->in6p_faddr; 1661 } 1662 #endif /* INET6 */ 1663 #if defined(INET6) && defined(INET) 1664 else 1665 #endif 1666 #ifdef INET 1667 { 1668 struct ip *ip; 1669 1670 ip = (struct ip *)ip_ptr; 1671 ip->ip_v = IPVERSION; 1672 ip->ip_hl = 5; 1673 ip->ip_tos = inp->inp_ip_tos; 1674 ip->ip_len = 0; 1675 ip->ip_id = 0; 1676 ip->ip_off = 0; 1677 ip->ip_ttl = inp->inp_ip_ttl; 1678 ip->ip_sum = 0; 1679 if (port == 0) 1680 ip->ip_p = IPPROTO_TCP; 1681 else 1682 ip->ip_p = IPPROTO_UDP; 1683 ip->ip_src = inp->inp_laddr; 1684 ip->ip_dst = inp->inp_faddr; 1685 } 1686 #endif /* INET */ 1687 th->th_sport = inp->inp_lport; 1688 th->th_dport = inp->inp_fport; 1689 th->th_seq = 0; 1690 th->th_ack = 0; 1691 th->th_off = 5; 1692 tcp_set_flags(th, 0); 1693 th->th_win = 0; 1694 th->th_urp = 0; 1695 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1696 } 1697 1698 /* 1699 * Create template to be used to send tcp packets on a connection. 1700 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1701 * use for this function is in keepalives, which use tcp_respond. 1702 */ 1703 struct tcptemp * 1704 tcpip_maketemplate(struct inpcb *inp) 1705 { 1706 struct tcptemp *t; 1707 1708 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1709 if (t == NULL) 1710 return (NULL); 1711 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1712 return (t); 1713 } 1714 1715 /* 1716 * Send a single message to the TCP at address specified by 1717 * the given TCP/IP header. If m == NULL, then we make a copy 1718 * of the tcpiphdr at th and send directly to the addressed host. 1719 * This is used to force keep alive messages out using the TCP 1720 * template for a connection. If flags are given then we send 1721 * a message back to the TCP which originated the segment th, 1722 * and discard the mbuf containing it and any other attached mbufs. 1723 * 1724 * In any case the ack and sequence number of the transmitted 1725 * segment are as specified by the parameters. 1726 * 1727 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1728 */ 1729 void 1730 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1731 tcp_seq ack, tcp_seq seq, int flags) 1732 { 1733 struct tcpopt to; 1734 struct inpcb *inp; 1735 struct ip *ip; 1736 struct mbuf *optm; 1737 struct udphdr *uh = NULL; 1738 struct tcphdr *nth; 1739 struct tcp_log_buffer *lgb; 1740 u_char *optp; 1741 #ifdef INET6 1742 struct ip6_hdr *ip6; 1743 int isipv6; 1744 #endif /* INET6 */ 1745 int optlen, tlen, win, ulen; 1746 bool incl_opts; 1747 uint16_t port; 1748 int output_ret; 1749 #ifdef INVARIANTS 1750 int thflags = tcp_get_flags(th); 1751 #endif 1752 1753 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1754 NET_EPOCH_ASSERT(); 1755 1756 #ifdef INET6 1757 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1758 ip6 = ipgen; 1759 #endif /* INET6 */ 1760 ip = ipgen; 1761 1762 if (tp != NULL) { 1763 inp = tp->t_inpcb; 1764 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1765 INP_LOCK_ASSERT(inp); 1766 } else 1767 inp = NULL; 1768 1769 if (m != NULL) { 1770 #ifdef INET6 1771 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1772 port = m->m_pkthdr.tcp_tun_port; 1773 else 1774 #endif 1775 if (ip && (ip->ip_p == IPPROTO_UDP)) 1776 port = m->m_pkthdr.tcp_tun_port; 1777 else 1778 port = 0; 1779 } else 1780 port = tp->t_port; 1781 1782 incl_opts = false; 1783 win = 0; 1784 if (tp != NULL) { 1785 if (!(flags & TH_RST)) { 1786 win = sbspace(&inp->inp_socket->so_rcv); 1787 if (win > TCP_MAXWIN << tp->rcv_scale) 1788 win = TCP_MAXWIN << tp->rcv_scale; 1789 } 1790 if ((tp->t_flags & TF_NOOPT) == 0) 1791 incl_opts = true; 1792 } 1793 if (m == NULL) { 1794 m = m_gethdr(M_NOWAIT, MT_DATA); 1795 if (m == NULL) 1796 return; 1797 m->m_data += max_linkhdr; 1798 #ifdef INET6 1799 if (isipv6) { 1800 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1801 sizeof(struct ip6_hdr)); 1802 ip6 = mtod(m, struct ip6_hdr *); 1803 nth = (struct tcphdr *)(ip6 + 1); 1804 if (port) { 1805 /* Insert a UDP header */ 1806 uh = (struct udphdr *)nth; 1807 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1808 uh->uh_dport = port; 1809 nth = (struct tcphdr *)(uh + 1); 1810 } 1811 } else 1812 #endif /* INET6 */ 1813 { 1814 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1815 ip = mtod(m, struct ip *); 1816 nth = (struct tcphdr *)(ip + 1); 1817 if (port) { 1818 /* Insert a UDP header */ 1819 uh = (struct udphdr *)nth; 1820 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1821 uh->uh_dport = port; 1822 nth = (struct tcphdr *)(uh + 1); 1823 } 1824 } 1825 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1826 flags = TH_ACK; 1827 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1828 struct mbuf *n; 1829 1830 /* Can't reuse 'm', allocate a new mbuf. */ 1831 n = m_gethdr(M_NOWAIT, MT_DATA); 1832 if (n == NULL) { 1833 m_freem(m); 1834 return; 1835 } 1836 1837 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1838 m_freem(m); 1839 m_freem(n); 1840 return; 1841 } 1842 1843 n->m_data += max_linkhdr; 1844 /* m_len is set later */ 1845 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1846 #ifdef INET6 1847 if (isipv6) { 1848 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1849 sizeof(struct ip6_hdr)); 1850 ip6 = mtod(n, struct ip6_hdr *); 1851 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1852 nth = (struct tcphdr *)(ip6 + 1); 1853 if (port) { 1854 /* Insert a UDP header */ 1855 uh = (struct udphdr *)nth; 1856 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1857 uh->uh_dport = port; 1858 nth = (struct tcphdr *)(uh + 1); 1859 } 1860 } else 1861 #endif /* INET6 */ 1862 { 1863 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1864 ip = mtod(n, struct ip *); 1865 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1866 nth = (struct tcphdr *)(ip + 1); 1867 if (port) { 1868 /* Insert a UDP header */ 1869 uh = (struct udphdr *)nth; 1870 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1871 uh->uh_dport = port; 1872 nth = (struct tcphdr *)(uh + 1); 1873 } 1874 } 1875 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1876 xchg(nth->th_dport, nth->th_sport, uint16_t); 1877 th = nth; 1878 m_freem(m); 1879 m = n; 1880 } else { 1881 /* 1882 * reuse the mbuf. 1883 * XXX MRT We inherit the FIB, which is lucky. 1884 */ 1885 m_freem(m->m_next); 1886 m->m_next = NULL; 1887 m->m_data = (caddr_t)ipgen; 1888 /* m_len is set later */ 1889 #ifdef INET6 1890 if (isipv6) { 1891 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1892 nth = (struct tcphdr *)(ip6 + 1); 1893 } else 1894 #endif /* INET6 */ 1895 { 1896 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1897 nth = (struct tcphdr *)(ip + 1); 1898 } 1899 if (th != nth) { 1900 /* 1901 * this is usually a case when an extension header 1902 * exists between the IPv6 header and the 1903 * TCP header. 1904 */ 1905 nth->th_sport = th->th_sport; 1906 nth->th_dport = th->th_dport; 1907 } 1908 xchg(nth->th_dport, nth->th_sport, uint16_t); 1909 #undef xchg 1910 } 1911 tlen = 0; 1912 #ifdef INET6 1913 if (isipv6) 1914 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1915 #endif 1916 #if defined(INET) && defined(INET6) 1917 else 1918 #endif 1919 #ifdef INET 1920 tlen = sizeof (struct tcpiphdr); 1921 #endif 1922 if (port) 1923 tlen += sizeof (struct udphdr); 1924 #ifdef INVARIANTS 1925 m->m_len = 0; 1926 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1927 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1928 m, tlen, (long)M_TRAILINGSPACE(m))); 1929 #endif 1930 m->m_len = tlen; 1931 to.to_flags = 0; 1932 if (incl_opts) { 1933 /* Make sure we have room. */ 1934 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1935 m->m_next = m_get(M_NOWAIT, MT_DATA); 1936 if (m->m_next) { 1937 optp = mtod(m->m_next, u_char *); 1938 optm = m->m_next; 1939 } else 1940 incl_opts = false; 1941 } else { 1942 optp = (u_char *) (nth + 1); 1943 optm = m; 1944 } 1945 } 1946 if (incl_opts) { 1947 /* Timestamps. */ 1948 if (tp->t_flags & TF_RCVD_TSTMP) { 1949 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1950 to.to_tsecr = tp->ts_recent; 1951 to.to_flags |= TOF_TS; 1952 } 1953 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1954 /* TCP-MD5 (RFC2385). */ 1955 if (tp->t_flags & TF_SIGNATURE) 1956 to.to_flags |= TOF_SIGNATURE; 1957 #endif 1958 /* Add the options. */ 1959 tlen += optlen = tcp_addoptions(&to, optp); 1960 1961 /* Update m_len in the correct mbuf. */ 1962 optm->m_len += optlen; 1963 } else 1964 optlen = 0; 1965 #ifdef INET6 1966 if (isipv6) { 1967 if (uh) { 1968 ulen = tlen - sizeof(struct ip6_hdr); 1969 uh->uh_ulen = htons(ulen); 1970 } 1971 ip6->ip6_flow = 0; 1972 ip6->ip6_vfc = IPV6_VERSION; 1973 if (port) 1974 ip6->ip6_nxt = IPPROTO_UDP; 1975 else 1976 ip6->ip6_nxt = IPPROTO_TCP; 1977 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1978 } 1979 #endif 1980 #if defined(INET) && defined(INET6) 1981 else 1982 #endif 1983 #ifdef INET 1984 { 1985 if (uh) { 1986 ulen = tlen - sizeof(struct ip); 1987 uh->uh_ulen = htons(ulen); 1988 } 1989 ip->ip_len = htons(tlen); 1990 ip->ip_ttl = V_ip_defttl; 1991 if (port) { 1992 ip->ip_p = IPPROTO_UDP; 1993 } else { 1994 ip->ip_p = IPPROTO_TCP; 1995 } 1996 if (V_path_mtu_discovery) 1997 ip->ip_off |= htons(IP_DF); 1998 } 1999 #endif 2000 m->m_pkthdr.len = tlen; 2001 m->m_pkthdr.rcvif = NULL; 2002 #ifdef MAC 2003 if (inp != NULL) { 2004 /* 2005 * Packet is associated with a socket, so allow the 2006 * label of the response to reflect the socket label. 2007 */ 2008 INP_LOCK_ASSERT(inp); 2009 mac_inpcb_create_mbuf(inp, m); 2010 } else { 2011 /* 2012 * Packet is not associated with a socket, so possibly 2013 * update the label in place. 2014 */ 2015 mac_netinet_tcp_reply(m); 2016 } 2017 #endif 2018 nth->th_seq = htonl(seq); 2019 nth->th_ack = htonl(ack); 2020 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2021 tcp_set_flags(nth, flags); 2022 if (tp != NULL) 2023 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2024 else 2025 nth->th_win = htons((u_short)win); 2026 nth->th_urp = 0; 2027 2028 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2029 if (to.to_flags & TOF_SIGNATURE) { 2030 if (!TCPMD5_ENABLED() || 2031 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2032 m_freem(m); 2033 return; 2034 } 2035 } 2036 #endif 2037 2038 #ifdef INET6 2039 if (isipv6) { 2040 if (port) { 2041 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2042 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2043 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2044 nth->th_sum = 0; 2045 } else { 2046 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2047 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2048 nth->th_sum = in6_cksum_pseudo(ip6, 2049 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2050 } 2051 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2052 NULL, NULL); 2053 } 2054 #endif /* INET6 */ 2055 #if defined(INET6) && defined(INET) 2056 else 2057 #endif 2058 #ifdef INET 2059 { 2060 if (port) { 2061 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2062 htons(ulen + IPPROTO_UDP)); 2063 m->m_pkthdr.csum_flags = CSUM_UDP; 2064 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2065 nth->th_sum = 0; 2066 } else { 2067 m->m_pkthdr.csum_flags = CSUM_TCP; 2068 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2069 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2070 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2071 } 2072 } 2073 #endif /* INET */ 2074 #ifdef TCPDEBUG 2075 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2076 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2077 #endif 2078 TCP_PROBE3(debug__output, tp, th, m); 2079 if (flags & TH_RST) 2080 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2081 lgb = NULL; 2082 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2083 if (INP_WLOCKED(inp)) { 2084 union tcp_log_stackspecific log; 2085 struct timeval tv; 2086 2087 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2088 log.u_bbr.inhpts = tp->t_inpcb->inp_in_hpts; 2089 log.u_bbr.flex8 = 4; 2090 log.u_bbr.pkts_out = tp->t_maxseg; 2091 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2092 log.u_bbr.delivered = 0; 2093 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2094 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2095 } else { 2096 /* 2097 * We can not log the packet, since we only own the 2098 * read lock, but a write lock is needed. The read lock 2099 * is not upgraded to a write lock, since only getting 2100 * the read lock was done intentionally to improve the 2101 * handling of SYN flooding attacks. 2102 * This happens only for pure SYN segments received in 2103 * the initial CLOSED state, or received in a more 2104 * advanced state than listen and the UDP encapsulation 2105 * port is unexpected. 2106 * The incoming SYN segments do not really belong to 2107 * the TCP connection and the handling does not change 2108 * the state of the TCP connection. Therefore, the 2109 * sending of the RST segments is not logged. Please 2110 * note that also the incoming SYN segments are not 2111 * logged. 2112 * 2113 * The following code ensures that the above description 2114 * is and stays correct. 2115 */ 2116 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2117 (tp->t_state == TCPS_CLOSED || 2118 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2119 ("%s: Logging of TCP segment with flags 0x%b and " 2120 "UDP encapsulation port %u skipped in state %s", 2121 __func__, thflags, PRINT_TH_FLAGS, 2122 ntohs(port), tcpstates[tp->t_state])); 2123 } 2124 } 2125 2126 #ifdef INET6 2127 if (isipv6) { 2128 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2129 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2130 } 2131 #endif /* INET6 */ 2132 #if defined(INET) && defined(INET6) 2133 else 2134 #endif 2135 #ifdef INET 2136 { 2137 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2138 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2139 } 2140 #endif 2141 if (lgb != NULL) 2142 lgb->tlb_errno = output_ret; 2143 } 2144 2145 /* 2146 * Create a new TCP control block, making an 2147 * empty reassembly queue and hooking it to the argument 2148 * protocol control block. The `inp' parameter must have 2149 * come from the zone allocator set up in tcp_init(). 2150 */ 2151 struct tcpcb * 2152 tcp_newtcpcb(struct inpcb *inp) 2153 { 2154 struct tcpcb_mem *tm; 2155 struct tcpcb *tp; 2156 #ifdef INET6 2157 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2158 #endif /* INET6 */ 2159 2160 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2161 if (tm == NULL) 2162 return (NULL); 2163 tp = &tm->tcb; 2164 2165 /* Initialise cc_var struct for this tcpcb. */ 2166 tp->ccv = &tm->ccv; 2167 tp->ccv->type = IPPROTO_TCP; 2168 tp->ccv->ccvc.tcp = tp; 2169 rw_rlock(&tcp_function_lock); 2170 tp->t_fb = tcp_func_set_ptr; 2171 refcount_acquire(&tp->t_fb->tfb_refcnt); 2172 rw_runlock(&tcp_function_lock); 2173 /* 2174 * Use the current system default CC algorithm. 2175 */ 2176 cc_attach(tp, CC_DEFAULT_ALGO()); 2177 2178 /* 2179 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2180 * is called. 2181 */ 2182 in_pcbref(inp); /* Reference for tcpcb */ 2183 tp->t_inpcb = inp; 2184 2185 if (CC_ALGO(tp)->cb_init != NULL) 2186 if (CC_ALGO(tp)->cb_init(tp->ccv, NULL) > 0) { 2187 cc_detach(tp); 2188 if (tp->t_fb->tfb_tcp_fb_fini) 2189 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2190 in_pcbrele_wlocked(inp); 2191 refcount_release(&tp->t_fb->tfb_refcnt); 2192 uma_zfree(V_tcpcb_zone, tm); 2193 return (NULL); 2194 } 2195 2196 #ifdef TCP_HHOOK 2197 tp->osd = &tm->osd; 2198 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2199 if (tp->t_fb->tfb_tcp_fb_fini) 2200 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2201 in_pcbrele_wlocked(inp); 2202 refcount_release(&tp->t_fb->tfb_refcnt); 2203 uma_zfree(V_tcpcb_zone, tm); 2204 return (NULL); 2205 } 2206 #endif 2207 2208 #ifdef VIMAGE 2209 tp->t_vnet = inp->inp_vnet; 2210 #endif 2211 tp->t_timers = &tm->tt; 2212 TAILQ_INIT(&tp->t_segq); 2213 tp->t_maxseg = 2214 #ifdef INET6 2215 isipv6 ? V_tcp_v6mssdflt : 2216 #endif /* INET6 */ 2217 V_tcp_mssdflt; 2218 2219 /* Set up our timeouts. */ 2220 callout_init(&tp->t_timers->tt_rexmt, 1); 2221 callout_init(&tp->t_timers->tt_persist, 1); 2222 callout_init(&tp->t_timers->tt_keep, 1); 2223 callout_init(&tp->t_timers->tt_2msl, 1); 2224 callout_init(&tp->t_timers->tt_delack, 1); 2225 2226 if (V_tcp_do_rfc1323) 2227 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2228 if (V_tcp_do_sack) 2229 tp->t_flags |= TF_SACK_PERMIT; 2230 TAILQ_INIT(&tp->snd_holes); 2231 2232 /* 2233 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2234 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2235 * reasonable initial retransmit time. 2236 */ 2237 tp->t_srtt = TCPTV_SRTTBASE; 2238 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2239 tp->t_rttmin = tcp_rexmit_min; 2240 tp->t_rxtcur = tcp_rexmit_initial; 2241 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2242 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2243 tp->t_rcvtime = ticks; 2244 /* 2245 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2246 * because the socket may be bound to an IPv6 wildcard address, 2247 * which may match an IPv4-mapped IPv6 address. 2248 */ 2249 inp->inp_ip_ttl = V_ip_defttl; 2250 inp->inp_ppcb = tp; 2251 #ifdef TCPPCAP 2252 /* 2253 * Init the TCP PCAP queues. 2254 */ 2255 tcp_pcap_tcpcb_init(tp); 2256 #endif 2257 #ifdef TCP_BLACKBOX 2258 /* Initialize the per-TCPCB log data. */ 2259 tcp_log_tcpcbinit(tp); 2260 #endif 2261 tp->t_pacing_rate = -1; 2262 if (tp->t_fb->tfb_tcp_fb_init) { 2263 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2264 refcount_release(&tp->t_fb->tfb_refcnt); 2265 in_pcbrele_wlocked(inp); 2266 uma_zfree(V_tcpcb_zone, tm); 2267 return (NULL); 2268 } 2269 } 2270 #ifdef STATS 2271 if (V_tcp_perconn_stats_enable == 1) 2272 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2273 #endif 2274 if (V_tcp_do_lrd) 2275 tp->t_flags |= TF_LRD; 2276 return (tp); /* XXX */ 2277 } 2278 2279 /* 2280 * Drop a TCP connection, reporting 2281 * the specified error. If connection is synchronized, 2282 * then send a RST to peer. 2283 */ 2284 struct tcpcb * 2285 tcp_drop(struct tcpcb *tp, int errno) 2286 { 2287 struct socket *so = tp->t_inpcb->inp_socket; 2288 2289 NET_EPOCH_ASSERT(); 2290 INP_WLOCK_ASSERT(tp->t_inpcb); 2291 2292 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2293 tcp_state_change(tp, TCPS_CLOSED); 2294 /* Don't use tcp_output() here due to possible recursion. */ 2295 (void)tcp_output_nodrop(tp); 2296 TCPSTAT_INC(tcps_drops); 2297 } else 2298 TCPSTAT_INC(tcps_conndrops); 2299 if (errno == ETIMEDOUT && tp->t_softerror) 2300 errno = tp->t_softerror; 2301 so->so_error = errno; 2302 return (tcp_close(tp)); 2303 } 2304 2305 void 2306 tcp_discardcb(struct tcpcb *tp) 2307 { 2308 struct inpcb *inp = tp->t_inpcb; 2309 2310 INP_WLOCK_ASSERT(inp); 2311 2312 /* 2313 * Make sure that all of our timers are stopped before we delete the 2314 * PCB. 2315 * 2316 * If stopping a timer fails, we schedule a discard function in same 2317 * callout, and the last discard function called will take care of 2318 * deleting the tcpcb. 2319 */ 2320 tp->t_timers->tt_draincnt = 0; 2321 tcp_timer_stop(tp, TT_REXMT); 2322 tcp_timer_stop(tp, TT_PERSIST); 2323 tcp_timer_stop(tp, TT_KEEP); 2324 tcp_timer_stop(tp, TT_2MSL); 2325 tcp_timer_stop(tp, TT_DELACK); 2326 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2327 /* 2328 * Call the stop-all function of the methods, 2329 * this function should call the tcp_timer_stop() 2330 * method with each of the function specific timeouts. 2331 * That stop will be called via the tfb_tcp_timer_stop() 2332 * which should use the async drain function of the 2333 * callout system (see tcp_var.h). 2334 */ 2335 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2336 } 2337 2338 /* free the reassembly queue, if any */ 2339 tcp_reass_flush(tp); 2340 2341 #ifdef TCP_OFFLOAD 2342 /* Disconnect offload device, if any. */ 2343 if (tp->t_flags & TF_TOE) 2344 tcp_offload_detach(tp); 2345 #endif 2346 2347 tcp_free_sackholes(tp); 2348 2349 #ifdef TCPPCAP 2350 /* Free the TCP PCAP queues. */ 2351 tcp_pcap_drain(&(tp->t_inpkts)); 2352 tcp_pcap_drain(&(tp->t_outpkts)); 2353 #endif 2354 2355 /* Allow the CC algorithm to clean up after itself. */ 2356 if (CC_ALGO(tp)->cb_destroy != NULL) 2357 CC_ALGO(tp)->cb_destroy(tp->ccv); 2358 CC_DATA(tp) = NULL; 2359 /* Detach from the CC algorithm */ 2360 cc_detach(tp); 2361 2362 #ifdef TCP_HHOOK 2363 khelp_destroy_osd(tp->osd); 2364 #endif 2365 #ifdef STATS 2366 stats_blob_destroy(tp->t_stats); 2367 #endif 2368 2369 CC_ALGO(tp) = NULL; 2370 inp->inp_ppcb = NULL; 2371 if (tp->t_timers->tt_draincnt == 0) { 2372 bool released __diagused; 2373 2374 released = tcp_freecb(tp); 2375 KASSERT(!released, ("%s: inp %p should not have been released " 2376 "here", __func__, inp)); 2377 } 2378 } 2379 2380 bool 2381 tcp_freecb(struct tcpcb *tp) 2382 { 2383 struct inpcb *inp = tp->t_inpcb; 2384 struct socket *so = inp->inp_socket; 2385 #ifdef INET6 2386 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2387 #endif 2388 2389 INP_WLOCK_ASSERT(inp); 2390 MPASS(tp->t_timers->tt_draincnt == 0); 2391 2392 /* We own the last reference on tcpcb, let's free it. */ 2393 #ifdef TCP_BLACKBOX 2394 tcp_log_tcpcbfini(tp); 2395 #endif 2396 TCPSTATES_DEC(tp->t_state); 2397 if (tp->t_fb->tfb_tcp_fb_fini) 2398 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2399 2400 /* 2401 * If we got enough samples through the srtt filter, 2402 * save the rtt and rttvar in the routing entry. 2403 * 'Enough' is arbitrarily defined as 4 rtt samples. 2404 * 4 samples is enough for the srtt filter to converge 2405 * to within enough % of the correct value; fewer samples 2406 * and we could save a bogus rtt. The danger is not high 2407 * as tcp quickly recovers from everything. 2408 * XXX: Works very well but needs some more statistics! 2409 * 2410 * XXXRRS: Updating must be after the stack fini() since 2411 * that may be converting some internal representation of 2412 * say srtt etc into the general one used by other stacks. 2413 * Lets also at least protect against the so being NULL 2414 * as RW stated below. 2415 */ 2416 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2417 struct hc_metrics_lite metrics; 2418 uint32_t ssthresh; 2419 2420 bzero(&metrics, sizeof(metrics)); 2421 /* 2422 * Update the ssthresh always when the conditions below 2423 * are satisfied. This gives us better new start value 2424 * for the congestion avoidance for new connections. 2425 * ssthresh is only set if packet loss occurred on a session. 2426 * 2427 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2428 * being torn down. Ideally this code would not use 'so'. 2429 */ 2430 ssthresh = tp->snd_ssthresh; 2431 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2432 /* 2433 * convert the limit from user data bytes to 2434 * packets then to packet data bytes. 2435 */ 2436 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2437 if (ssthresh < 2) 2438 ssthresh = 2; 2439 ssthresh *= (tp->t_maxseg + 2440 #ifdef INET6 2441 (isipv6 ? sizeof (struct ip6_hdr) + 2442 sizeof (struct tcphdr) : 2443 #endif 2444 sizeof (struct tcpiphdr) 2445 #ifdef INET6 2446 ) 2447 #endif 2448 ); 2449 } else 2450 ssthresh = 0; 2451 metrics.rmx_ssthresh = ssthresh; 2452 2453 metrics.rmx_rtt = tp->t_srtt; 2454 metrics.rmx_rttvar = tp->t_rttvar; 2455 metrics.rmx_cwnd = tp->snd_cwnd; 2456 metrics.rmx_sendpipe = 0; 2457 metrics.rmx_recvpipe = 0; 2458 2459 tcp_hc_update(&inp->inp_inc, &metrics); 2460 } 2461 2462 refcount_release(&tp->t_fb->tfb_refcnt); 2463 uma_zfree(V_tcpcb_zone, tp); 2464 2465 return (in_pcbrele_wlocked(inp)); 2466 } 2467 2468 /* 2469 * Attempt to close a TCP control block, marking it as dropped, and freeing 2470 * the socket if we hold the only reference. 2471 */ 2472 struct tcpcb * 2473 tcp_close(struct tcpcb *tp) 2474 { 2475 struct inpcb *inp = tp->t_inpcb; 2476 struct socket *so; 2477 2478 INP_WLOCK_ASSERT(inp); 2479 2480 #ifdef TCP_OFFLOAD 2481 if (tp->t_state == TCPS_LISTEN) 2482 tcp_offload_listen_stop(tp); 2483 #endif 2484 /* 2485 * This releases the TFO pending counter resource for TFO listen 2486 * sockets as well as passively-created TFO sockets that transition 2487 * from SYN_RECEIVED to CLOSED. 2488 */ 2489 if (tp->t_tfo_pending) { 2490 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2491 tp->t_tfo_pending = NULL; 2492 } 2493 #ifdef TCPHPTS 2494 tcp_hpts_remove(inp); 2495 #endif 2496 in_pcbdrop(inp); 2497 TCPSTAT_INC(tcps_closed); 2498 if (tp->t_state != TCPS_CLOSED) 2499 tcp_state_change(tp, TCPS_CLOSED); 2500 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2501 so = inp->inp_socket; 2502 soisdisconnected(so); 2503 if (inp->inp_flags & INP_SOCKREF) { 2504 inp->inp_flags &= ~INP_SOCKREF; 2505 INP_WUNLOCK(inp); 2506 sorele(so); 2507 return (NULL); 2508 } 2509 return (tp); 2510 } 2511 2512 void 2513 tcp_drain(void) 2514 { 2515 VNET_ITERATOR_DECL(vnet_iter); 2516 2517 if (!do_tcpdrain) 2518 return; 2519 2520 VNET_LIST_RLOCK_NOSLEEP(); 2521 VNET_FOREACH(vnet_iter) { 2522 CURVNET_SET(vnet_iter); 2523 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2524 INPLOOKUP_WLOCKPCB); 2525 struct inpcb *inpb; 2526 struct tcpcb *tcpb; 2527 2528 /* 2529 * Walk the tcpbs, if existing, and flush the reassembly queue, 2530 * if there is one... 2531 * XXX: The "Net/3" implementation doesn't imply that the TCP 2532 * reassembly queue should be flushed, but in a situation 2533 * where we're really low on mbufs, this is potentially 2534 * useful. 2535 */ 2536 while ((inpb = inp_next(&inpi)) != NULL) { 2537 if (inpb->inp_flags & INP_TIMEWAIT) 2538 continue; 2539 if ((tcpb = intotcpcb(inpb)) != NULL) { 2540 tcp_reass_flush(tcpb); 2541 tcp_clean_sackreport(tcpb); 2542 #ifdef TCP_BLACKBOX 2543 tcp_log_drain(tcpb); 2544 #endif 2545 #ifdef TCPPCAP 2546 if (tcp_pcap_aggressive_free) { 2547 /* Free the TCP PCAP queues. */ 2548 tcp_pcap_drain(&(tcpb->t_inpkts)); 2549 tcp_pcap_drain(&(tcpb->t_outpkts)); 2550 } 2551 #endif 2552 } 2553 } 2554 CURVNET_RESTORE(); 2555 } 2556 VNET_LIST_RUNLOCK_NOSLEEP(); 2557 } 2558 2559 /* 2560 * Notify a tcp user of an asynchronous error; 2561 * store error as soft error, but wake up user 2562 * (for now, won't do anything until can select for soft error). 2563 * 2564 * Do not wake up user since there currently is no mechanism for 2565 * reporting soft errors (yet - a kqueue filter may be added). 2566 */ 2567 static struct inpcb * 2568 tcp_notify(struct inpcb *inp, int error) 2569 { 2570 struct tcpcb *tp; 2571 2572 INP_WLOCK_ASSERT(inp); 2573 2574 if ((inp->inp_flags & INP_TIMEWAIT) || 2575 (inp->inp_flags & INP_DROPPED)) 2576 return (inp); 2577 2578 tp = intotcpcb(inp); 2579 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2580 2581 /* 2582 * Ignore some errors if we are hooked up. 2583 * If connection hasn't completed, has retransmitted several times, 2584 * and receives a second error, give up now. This is better 2585 * than waiting a long time to establish a connection that 2586 * can never complete. 2587 */ 2588 if (tp->t_state == TCPS_ESTABLISHED && 2589 (error == EHOSTUNREACH || error == ENETUNREACH || 2590 error == EHOSTDOWN)) { 2591 if (inp->inp_route.ro_nh) { 2592 NH_FREE(inp->inp_route.ro_nh); 2593 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2594 } 2595 return (inp); 2596 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2597 tp->t_softerror) { 2598 tp = tcp_drop(tp, error); 2599 if (tp != NULL) 2600 return (inp); 2601 else 2602 return (NULL); 2603 } else { 2604 tp->t_softerror = error; 2605 return (inp); 2606 } 2607 #if 0 2608 wakeup( &so->so_timeo); 2609 sorwakeup(so); 2610 sowwakeup(so); 2611 #endif 2612 } 2613 2614 static int 2615 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2616 { 2617 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2618 INPLOOKUP_RLOCKPCB); 2619 struct xinpgen xig; 2620 struct inpcb *inp; 2621 int error; 2622 2623 if (req->newptr != NULL) 2624 return (EPERM); 2625 2626 if (req->oldptr == NULL) { 2627 int n; 2628 2629 n = V_tcbinfo.ipi_count + 2630 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2631 n += imax(n / 8, 10); 2632 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2633 return (0); 2634 } 2635 2636 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2637 return (error); 2638 2639 bzero(&xig, sizeof(xig)); 2640 xig.xig_len = sizeof xig; 2641 xig.xig_count = V_tcbinfo.ipi_count + 2642 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2643 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2644 xig.xig_sogen = so_gencnt; 2645 error = SYSCTL_OUT(req, &xig, sizeof xig); 2646 if (error) 2647 return (error); 2648 2649 error = syncache_pcblist(req); 2650 if (error) 2651 return (error); 2652 2653 while ((inp = inp_next(&inpi)) != NULL) { 2654 if (inp->inp_gencnt <= xig.xig_gen) { 2655 int crerr; 2656 2657 /* 2658 * XXX: This use of cr_cansee(), introduced with 2659 * TCP state changes, is not quite right, but for 2660 * now, better than nothing. 2661 */ 2662 if (inp->inp_flags & INP_TIMEWAIT) { 2663 if (intotw(inp) != NULL) 2664 crerr = cr_cansee(req->td->td_ucred, 2665 intotw(inp)->tw_cred); 2666 else 2667 crerr = EINVAL; /* Skip this inp. */ 2668 } else 2669 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2670 if (crerr == 0) { 2671 struct xtcpcb xt; 2672 2673 tcp_inptoxtp(inp, &xt); 2674 error = SYSCTL_OUT(req, &xt, sizeof xt); 2675 if (error) { 2676 INP_RUNLOCK(inp); 2677 break; 2678 } else 2679 continue; 2680 } 2681 } 2682 } 2683 2684 if (!error) { 2685 /* 2686 * Give the user an updated idea of our state. 2687 * If the generation differs from what we told 2688 * her before, she knows that something happened 2689 * while we were processing this request, and it 2690 * might be necessary to retry. 2691 */ 2692 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2693 xig.xig_sogen = so_gencnt; 2694 xig.xig_count = V_tcbinfo.ipi_count + 2695 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2696 error = SYSCTL_OUT(req, &xig, sizeof xig); 2697 } 2698 2699 return (error); 2700 } 2701 2702 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2703 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2704 NULL, 0, tcp_pcblist, "S,xtcpcb", 2705 "List of active TCP connections"); 2706 2707 #ifdef INET 2708 static int 2709 tcp_getcred(SYSCTL_HANDLER_ARGS) 2710 { 2711 struct xucred xuc; 2712 struct sockaddr_in addrs[2]; 2713 struct epoch_tracker et; 2714 struct inpcb *inp; 2715 int error; 2716 2717 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2718 if (error) 2719 return (error); 2720 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2721 if (error) 2722 return (error); 2723 NET_EPOCH_ENTER(et); 2724 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2725 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2726 NET_EPOCH_EXIT(et); 2727 if (inp != NULL) { 2728 if (inp->inp_socket == NULL) 2729 error = ENOENT; 2730 if (error == 0) 2731 error = cr_canseeinpcb(req->td->td_ucred, inp); 2732 if (error == 0) 2733 cru2x(inp->inp_cred, &xuc); 2734 INP_RUNLOCK(inp); 2735 } else 2736 error = ENOENT; 2737 if (error == 0) 2738 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2739 return (error); 2740 } 2741 2742 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2743 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2744 0, 0, tcp_getcred, "S,xucred", 2745 "Get the xucred of a TCP connection"); 2746 #endif /* INET */ 2747 2748 #ifdef INET6 2749 static int 2750 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2751 { 2752 struct epoch_tracker et; 2753 struct xucred xuc; 2754 struct sockaddr_in6 addrs[2]; 2755 struct inpcb *inp; 2756 int error; 2757 #ifdef INET 2758 int mapped = 0; 2759 #endif 2760 2761 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2762 if (error) 2763 return (error); 2764 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2765 if (error) 2766 return (error); 2767 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2768 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2769 return (error); 2770 } 2771 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2772 #ifdef INET 2773 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2774 mapped = 1; 2775 else 2776 #endif 2777 return (EINVAL); 2778 } 2779 2780 NET_EPOCH_ENTER(et); 2781 #ifdef INET 2782 if (mapped == 1) 2783 inp = in_pcblookup(&V_tcbinfo, 2784 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2785 addrs[1].sin6_port, 2786 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2787 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2788 else 2789 #endif 2790 inp = in6_pcblookup(&V_tcbinfo, 2791 &addrs[1].sin6_addr, addrs[1].sin6_port, 2792 &addrs[0].sin6_addr, addrs[0].sin6_port, 2793 INPLOOKUP_RLOCKPCB, NULL); 2794 NET_EPOCH_EXIT(et); 2795 if (inp != NULL) { 2796 if (inp->inp_socket == NULL) 2797 error = ENOENT; 2798 if (error == 0) 2799 error = cr_canseeinpcb(req->td->td_ucred, inp); 2800 if (error == 0) 2801 cru2x(inp->inp_cred, &xuc); 2802 INP_RUNLOCK(inp); 2803 } else 2804 error = ENOENT; 2805 if (error == 0) 2806 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2807 return (error); 2808 } 2809 2810 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2811 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2812 0, 0, tcp6_getcred, "S,xucred", 2813 "Get the xucred of a TCP6 connection"); 2814 #endif /* INET6 */ 2815 2816 #ifdef INET 2817 /* Path MTU to try next when a fragmentation-needed message is received. */ 2818 static inline int 2819 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2820 { 2821 int mtu = ntohs(icp->icmp_nextmtu); 2822 2823 /* If no alternative MTU was proposed, try the next smaller one. */ 2824 if (!mtu) 2825 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2826 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2827 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2828 2829 return (mtu); 2830 } 2831 2832 static void 2833 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2834 { 2835 struct ip *ip = vip; 2836 struct tcphdr *th; 2837 struct in_addr faddr; 2838 struct inpcb *inp; 2839 struct tcpcb *tp; 2840 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2841 struct icmp *icp; 2842 struct in_conninfo inc; 2843 tcp_seq icmp_tcp_seq; 2844 int mtu; 2845 2846 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2847 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2848 return; 2849 2850 if (cmd == PRC_MSGSIZE) 2851 notify = tcp_mtudisc_notify; 2852 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2853 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2854 cmd == PRC_TIMXCEED_INTRANS) && ip) 2855 notify = tcp_drop_syn_sent; 2856 2857 /* 2858 * Hostdead is ugly because it goes linearly through all PCBs. 2859 * XXX: We never get this from ICMP, otherwise it makes an 2860 * excellent DoS attack on machines with many connections. 2861 */ 2862 else if (cmd == PRC_HOSTDEAD) 2863 ip = NULL; 2864 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2865 return; 2866 2867 if (ip == NULL) { 2868 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2869 return; 2870 } 2871 2872 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2873 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2874 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2875 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2876 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2877 /* signal EHOSTDOWN, as it flushes the cached route */ 2878 inp = (*notify)(inp, EHOSTDOWN); 2879 goto out; 2880 } 2881 icmp_tcp_seq = th->th_seq; 2882 if (inp != NULL) { 2883 if (!(inp->inp_flags & INP_TIMEWAIT) && 2884 !(inp->inp_flags & INP_DROPPED) && 2885 !(inp->inp_socket == NULL)) { 2886 tp = intotcpcb(inp); 2887 #ifdef TCP_OFFLOAD 2888 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2889 /* 2890 * MTU discovery for offloaded connections. Let 2891 * the TOE driver verify seq# and process it. 2892 */ 2893 mtu = tcp_next_pmtu(icp, ip); 2894 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2895 goto out; 2896 } 2897 #endif 2898 if (tp->t_port != port) { 2899 goto out; 2900 } 2901 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2902 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2903 if (cmd == PRC_MSGSIZE) { 2904 /* 2905 * MTU discovery: we got a needfrag and 2906 * will potentially try a lower MTU. 2907 */ 2908 mtu = tcp_next_pmtu(icp, ip); 2909 2910 /* 2911 * Only process the offered MTU if it 2912 * is smaller than the current one. 2913 */ 2914 if (mtu < tp->t_maxseg + 2915 sizeof(struct tcpiphdr)) { 2916 bzero(&inc, sizeof(inc)); 2917 inc.inc_faddr = faddr; 2918 inc.inc_fibnum = 2919 inp->inp_inc.inc_fibnum; 2920 tcp_hc_updatemtu(&inc, mtu); 2921 inp = tcp_mtudisc(inp, mtu); 2922 } 2923 } else 2924 inp = (*notify)(inp, 2925 inetctlerrmap[cmd]); 2926 } 2927 } 2928 } else { 2929 bzero(&inc, sizeof(inc)); 2930 inc.inc_fport = th->th_dport; 2931 inc.inc_lport = th->th_sport; 2932 inc.inc_faddr = faddr; 2933 inc.inc_laddr = ip->ip_src; 2934 syncache_unreach(&inc, icmp_tcp_seq, port); 2935 } 2936 out: 2937 if (inp != NULL) 2938 INP_WUNLOCK(inp); 2939 } 2940 2941 void 2942 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2943 { 2944 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2945 } 2946 2947 void 2948 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2949 { 2950 /* Its a tunneled TCP over UDP icmp */ 2951 struct ip *outer_ip, *inner_ip; 2952 struct icmp *icmp; 2953 struct udphdr *udp; 2954 struct tcphdr *th, ttemp; 2955 int i_hlen, o_len; 2956 uint16_t port; 2957 2958 inner_ip = (struct ip *)vip; 2959 icmp = (struct icmp *)((caddr_t)inner_ip - 2960 (sizeof(struct icmp) - sizeof(struct ip))); 2961 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2962 i_hlen = inner_ip->ip_hl << 2; 2963 o_len = ntohs(outer_ip->ip_len); 2964 if (o_len < 2965 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2966 /* Not enough data present */ 2967 return; 2968 } 2969 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2970 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2971 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2972 return; 2973 } 2974 port = udp->uh_dport; 2975 th = (struct tcphdr *)(udp + 1); 2976 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2977 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2978 /* Now adjust down the size of the outer IP header */ 2979 o_len -= sizeof(struct udphdr); 2980 outer_ip->ip_len = htons(o_len); 2981 /* Now call in to the normal handling code */ 2982 tcp_ctlinput_with_port(cmd, sa, vip, port); 2983 } 2984 #endif /* INET */ 2985 2986 #ifdef INET6 2987 static inline int 2988 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2989 { 2990 int mtu = ntohl(icmp6->icmp6_mtu); 2991 2992 /* 2993 * If no alternative MTU was proposed, or the proposed MTU was too 2994 * small, set to the min. 2995 */ 2996 if (mtu < IPV6_MMTU) 2997 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2998 return (mtu); 2999 } 3000 3001 static void 3002 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3003 { 3004 struct in6_addr *dst; 3005 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3006 struct ip6_hdr *ip6; 3007 struct mbuf *m; 3008 struct inpcb *inp; 3009 struct tcpcb *tp; 3010 struct icmp6_hdr *icmp6; 3011 struct ip6ctlparam *ip6cp = NULL; 3012 const struct sockaddr_in6 *sa6_src = NULL; 3013 struct in_conninfo inc; 3014 struct tcp_ports { 3015 uint16_t th_sport; 3016 uint16_t th_dport; 3017 } t_ports; 3018 tcp_seq icmp_tcp_seq; 3019 unsigned int mtu; 3020 unsigned int off; 3021 3022 if (sa->sa_family != AF_INET6 || 3023 sa->sa_len != sizeof(struct sockaddr_in6)) 3024 return; 3025 3026 /* if the parameter is from icmp6, decode it. */ 3027 if (d != NULL) { 3028 ip6cp = (struct ip6ctlparam *)d; 3029 icmp6 = ip6cp->ip6c_icmp6; 3030 m = ip6cp->ip6c_m; 3031 ip6 = ip6cp->ip6c_ip6; 3032 off = ip6cp->ip6c_off; 3033 sa6_src = ip6cp->ip6c_src; 3034 dst = ip6cp->ip6c_finaldst; 3035 } else { 3036 m = NULL; 3037 ip6 = NULL; 3038 off = 0; /* fool gcc */ 3039 sa6_src = &sa6_any; 3040 dst = NULL; 3041 } 3042 3043 if (cmd == PRC_MSGSIZE) 3044 notify = tcp_mtudisc_notify; 3045 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3046 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3047 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3048 notify = tcp_drop_syn_sent; 3049 3050 /* 3051 * Hostdead is ugly because it goes linearly through all PCBs. 3052 * XXX: We never get this from ICMP, otherwise it makes an 3053 * excellent DoS attack on machines with many connections. 3054 */ 3055 else if (cmd == PRC_HOSTDEAD) 3056 ip6 = NULL; 3057 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3058 return; 3059 3060 if (ip6 == NULL) { 3061 in6_pcbnotify(&V_tcbinfo, sa, 0, 3062 (const struct sockaddr *)sa6_src, 3063 0, cmd, NULL, notify); 3064 return; 3065 } 3066 3067 /* Check if we can safely get the ports from the tcp hdr */ 3068 if (m == NULL || 3069 (m->m_pkthdr.len < 3070 (int32_t) (off + sizeof(struct tcp_ports)))) { 3071 return; 3072 } 3073 bzero(&t_ports, sizeof(struct tcp_ports)); 3074 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3075 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3076 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3077 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3078 /* signal EHOSTDOWN, as it flushes the cached route */ 3079 inp = (*notify)(inp, EHOSTDOWN); 3080 goto out; 3081 } 3082 off += sizeof(struct tcp_ports); 3083 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3084 goto out; 3085 } 3086 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3087 if (inp != NULL) { 3088 if (!(inp->inp_flags & INP_TIMEWAIT) && 3089 !(inp->inp_flags & INP_DROPPED) && 3090 !(inp->inp_socket == NULL)) { 3091 tp = intotcpcb(inp); 3092 #ifdef TCP_OFFLOAD 3093 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3094 /* MTU discovery for offloaded connections. */ 3095 mtu = tcp6_next_pmtu(icmp6); 3096 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3097 goto out; 3098 } 3099 #endif 3100 if (tp->t_port != port) { 3101 goto out; 3102 } 3103 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3104 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3105 if (cmd == PRC_MSGSIZE) { 3106 /* 3107 * MTU discovery: 3108 * If we got a needfrag set the MTU 3109 * in the route to the suggested new 3110 * value (if given) and then notify. 3111 */ 3112 mtu = tcp6_next_pmtu(icmp6); 3113 3114 bzero(&inc, sizeof(inc)); 3115 inc.inc_fibnum = M_GETFIB(m); 3116 inc.inc_flags |= INC_ISIPV6; 3117 inc.inc6_faddr = *dst; 3118 if (in6_setscope(&inc.inc6_faddr, 3119 m->m_pkthdr.rcvif, NULL)) 3120 goto out; 3121 /* 3122 * Only process the offered MTU if it 3123 * is smaller than the current one. 3124 */ 3125 if (mtu < tp->t_maxseg + 3126 sizeof (struct tcphdr) + 3127 sizeof (struct ip6_hdr)) { 3128 tcp_hc_updatemtu(&inc, mtu); 3129 tcp_mtudisc(inp, mtu); 3130 ICMP6STAT_INC(icp6s_pmtuchg); 3131 } 3132 } else 3133 inp = (*notify)(inp, 3134 inet6ctlerrmap[cmd]); 3135 } 3136 } 3137 } else { 3138 bzero(&inc, sizeof(inc)); 3139 inc.inc_fibnum = M_GETFIB(m); 3140 inc.inc_flags |= INC_ISIPV6; 3141 inc.inc_fport = t_ports.th_dport; 3142 inc.inc_lport = t_ports.th_sport; 3143 inc.inc6_faddr = *dst; 3144 inc.inc6_laddr = ip6->ip6_src; 3145 syncache_unreach(&inc, icmp_tcp_seq, port); 3146 } 3147 out: 3148 if (inp != NULL) 3149 INP_WUNLOCK(inp); 3150 } 3151 3152 void 3153 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3154 { 3155 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3156 } 3157 3158 void 3159 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3160 { 3161 struct ip6ctlparam *ip6cp; 3162 struct mbuf *m; 3163 struct udphdr *udp; 3164 uint16_t port; 3165 3166 ip6cp = (struct ip6ctlparam *)d; 3167 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3168 if (m == NULL) { 3169 return; 3170 } 3171 udp = mtod(m, struct udphdr *); 3172 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3173 return; 3174 } 3175 port = udp->uh_dport; 3176 m_adj(m, sizeof(struct udphdr)); 3177 if ((m->m_flags & M_PKTHDR) == 0) { 3178 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3179 } 3180 /* Now call in to the normal handling code */ 3181 tcp6_ctlinput_with_port(cmd, sa, d, port); 3182 } 3183 3184 #endif /* INET6 */ 3185 3186 static uint32_t 3187 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3188 { 3189 SIPHASH_CTX ctx; 3190 uint32_t hash[2]; 3191 3192 KASSERT(len >= SIPHASH_KEY_LENGTH, 3193 ("%s: keylen %u too short ", __func__, len)); 3194 SipHash24_Init(&ctx); 3195 SipHash_SetKey(&ctx, (uint8_t *)key); 3196 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3197 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3198 switch (inc->inc_flags & INC_ISIPV6) { 3199 #ifdef INET 3200 case 0: 3201 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3202 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3203 break; 3204 #endif 3205 #ifdef INET6 3206 case INC_ISIPV6: 3207 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3208 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3209 break; 3210 #endif 3211 } 3212 SipHash_Final((uint8_t *)hash, &ctx); 3213 3214 return (hash[0] ^ hash[1]); 3215 } 3216 3217 uint32_t 3218 tcp_new_ts_offset(struct in_conninfo *inc) 3219 { 3220 struct in_conninfo inc_store, *local_inc; 3221 3222 if (!V_tcp_ts_offset_per_conn) { 3223 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3224 inc_store.inc_lport = 0; 3225 inc_store.inc_fport = 0; 3226 local_inc = &inc_store; 3227 } else { 3228 local_inc = inc; 3229 } 3230 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3231 sizeof(V_ts_offset_secret))); 3232 } 3233 3234 /* 3235 * Following is where TCP initial sequence number generation occurs. 3236 * 3237 * There are two places where we must use initial sequence numbers: 3238 * 1. In SYN-ACK packets. 3239 * 2. In SYN packets. 3240 * 3241 * All ISNs for SYN-ACK packets are generated by the syncache. See 3242 * tcp_syncache.c for details. 3243 * 3244 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3245 * depends on this property. In addition, these ISNs should be 3246 * unguessable so as to prevent connection hijacking. To satisfy 3247 * the requirements of this situation, the algorithm outlined in 3248 * RFC 1948 is used, with only small modifications. 3249 * 3250 * Implementation details: 3251 * 3252 * Time is based off the system timer, and is corrected so that it 3253 * increases by one megabyte per second. This allows for proper 3254 * recycling on high speed LANs while still leaving over an hour 3255 * before rollover. 3256 * 3257 * As reading the *exact* system time is too expensive to be done 3258 * whenever setting up a TCP connection, we increment the time 3259 * offset in two ways. First, a small random positive increment 3260 * is added to isn_offset for each connection that is set up. 3261 * Second, the function tcp_isn_tick fires once per clock tick 3262 * and increments isn_offset as necessary so that sequence numbers 3263 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3264 * random positive increments serve only to ensure that the same 3265 * exact sequence number is never sent out twice (as could otherwise 3266 * happen when a port is recycled in less than the system tick 3267 * interval.) 3268 * 3269 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3270 * between seeding of isn_secret. This is normally set to zero, 3271 * as reseeding should not be necessary. 3272 * 3273 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3274 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3275 * general, this means holding an exclusive (write) lock. 3276 */ 3277 3278 #define ISN_BYTES_PER_SECOND 1048576 3279 #define ISN_STATIC_INCREMENT 4096 3280 #define ISN_RANDOM_INCREMENT (4096 - 1) 3281 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3282 3283 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3284 VNET_DEFINE_STATIC(int, isn_last); 3285 VNET_DEFINE_STATIC(int, isn_last_reseed); 3286 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3287 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3288 3289 #define V_isn_secret VNET(isn_secret) 3290 #define V_isn_last VNET(isn_last) 3291 #define V_isn_last_reseed VNET(isn_last_reseed) 3292 #define V_isn_offset VNET(isn_offset) 3293 #define V_isn_offset_old VNET(isn_offset_old) 3294 3295 tcp_seq 3296 tcp_new_isn(struct in_conninfo *inc) 3297 { 3298 tcp_seq new_isn; 3299 u_int32_t projected_offset; 3300 3301 ISN_LOCK(); 3302 /* Seed if this is the first use, reseed if requested. */ 3303 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3304 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3305 < (u_int)ticks))) { 3306 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3307 V_isn_last_reseed = ticks; 3308 } 3309 3310 /* Compute the hash and return the ISN. */ 3311 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3312 sizeof(V_isn_secret)); 3313 V_isn_offset += ISN_STATIC_INCREMENT + 3314 (arc4random() & ISN_RANDOM_INCREMENT); 3315 if (ticks != V_isn_last) { 3316 projected_offset = V_isn_offset_old + 3317 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3318 if (SEQ_GT(projected_offset, V_isn_offset)) 3319 V_isn_offset = projected_offset; 3320 V_isn_offset_old = V_isn_offset; 3321 V_isn_last = ticks; 3322 } 3323 new_isn += V_isn_offset; 3324 ISN_UNLOCK(); 3325 return (new_isn); 3326 } 3327 3328 /* 3329 * When a specific ICMP unreachable message is received and the 3330 * connection state is SYN-SENT, drop the connection. This behavior 3331 * is controlled by the icmp_may_rst sysctl. 3332 */ 3333 struct inpcb * 3334 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3335 { 3336 struct tcpcb *tp; 3337 3338 NET_EPOCH_ASSERT(); 3339 INP_WLOCK_ASSERT(inp); 3340 3341 if ((inp->inp_flags & INP_TIMEWAIT) || 3342 (inp->inp_flags & INP_DROPPED)) 3343 return (inp); 3344 3345 tp = intotcpcb(inp); 3346 if (tp->t_state != TCPS_SYN_SENT) 3347 return (inp); 3348 3349 if (IS_FASTOPEN(tp->t_flags)) 3350 tcp_fastopen_disable_path(tp); 3351 3352 tp = tcp_drop(tp, errno); 3353 if (tp != NULL) 3354 return (inp); 3355 else 3356 return (NULL); 3357 } 3358 3359 /* 3360 * When `need fragmentation' ICMP is received, update our idea of the MSS 3361 * based on the new value. Also nudge TCP to send something, since we 3362 * know the packet we just sent was dropped. 3363 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3364 */ 3365 static struct inpcb * 3366 tcp_mtudisc_notify(struct inpcb *inp, int error) 3367 { 3368 3369 return (tcp_mtudisc(inp, -1)); 3370 } 3371 3372 static struct inpcb * 3373 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3374 { 3375 struct tcpcb *tp; 3376 struct socket *so; 3377 3378 INP_WLOCK_ASSERT(inp); 3379 if ((inp->inp_flags & INP_TIMEWAIT) || 3380 (inp->inp_flags & INP_DROPPED)) 3381 return (inp); 3382 3383 tp = intotcpcb(inp); 3384 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3385 3386 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3387 3388 so = inp->inp_socket; 3389 SOCKBUF_LOCK(&so->so_snd); 3390 /* If the mss is larger than the socket buffer, decrease the mss. */ 3391 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3392 tp->t_maxseg = so->so_snd.sb_hiwat; 3393 SOCKBUF_UNLOCK(&so->so_snd); 3394 3395 TCPSTAT_INC(tcps_mturesent); 3396 tp->t_rtttime = 0; 3397 tp->snd_nxt = tp->snd_una; 3398 tcp_free_sackholes(tp); 3399 tp->snd_recover = tp->snd_max; 3400 if (tp->t_flags & TF_SACK_PERMIT) 3401 EXIT_FASTRECOVERY(tp->t_flags); 3402 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3403 /* 3404 * Conceptually the snd_nxt setting 3405 * and freeing sack holes should 3406 * be done by the default stacks 3407 * own tfb_tcp_mtu_chg(). 3408 */ 3409 tp->t_fb->tfb_tcp_mtu_chg(tp); 3410 } 3411 if (tcp_output(tp) < 0) 3412 return (NULL); 3413 else 3414 return (inp); 3415 } 3416 3417 #ifdef INET 3418 /* 3419 * Look-up the routing entry to the peer of this inpcb. If no route 3420 * is found and it cannot be allocated, then return 0. This routine 3421 * is called by TCP routines that access the rmx structure and by 3422 * tcp_mss_update to get the peer/interface MTU. 3423 */ 3424 uint32_t 3425 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3426 { 3427 struct nhop_object *nh; 3428 struct ifnet *ifp; 3429 uint32_t maxmtu = 0; 3430 3431 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3432 3433 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3434 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3435 if (nh == NULL) 3436 return (0); 3437 3438 ifp = nh->nh_ifp; 3439 maxmtu = nh->nh_mtu; 3440 3441 /* Report additional interface capabilities. */ 3442 if (cap != NULL) { 3443 if (ifp->if_capenable & IFCAP_TSO4 && 3444 ifp->if_hwassist & CSUM_TSO) { 3445 cap->ifcap |= CSUM_TSO; 3446 cap->tsomax = ifp->if_hw_tsomax; 3447 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3448 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3449 } 3450 } 3451 } 3452 return (maxmtu); 3453 } 3454 #endif /* INET */ 3455 3456 #ifdef INET6 3457 uint32_t 3458 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3459 { 3460 struct nhop_object *nh; 3461 struct in6_addr dst6; 3462 uint32_t scopeid; 3463 struct ifnet *ifp; 3464 uint32_t maxmtu = 0; 3465 3466 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3467 3468 if (inc->inc_flags & INC_IPV6MINMTU) 3469 return (IPV6_MMTU); 3470 3471 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3472 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3473 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3474 if (nh == NULL) 3475 return (0); 3476 3477 ifp = nh->nh_ifp; 3478 maxmtu = nh->nh_mtu; 3479 3480 /* Report additional interface capabilities. */ 3481 if (cap != NULL) { 3482 if (ifp->if_capenable & IFCAP_TSO6 && 3483 ifp->if_hwassist & CSUM_TSO) { 3484 cap->ifcap |= CSUM_TSO; 3485 cap->tsomax = ifp->if_hw_tsomax; 3486 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3487 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3488 } 3489 } 3490 } 3491 3492 return (maxmtu); 3493 } 3494 3495 /* 3496 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3497 * 3498 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3499 * The right place to do that is ip6_setpktopt() that has just been 3500 * executed. By the way it just filled ip6po_minmtu for us. 3501 */ 3502 void 3503 tcp6_use_min_mtu(struct tcpcb *tp) 3504 { 3505 struct inpcb *inp = tp->t_inpcb; 3506 3507 INP_WLOCK_ASSERT(inp); 3508 /* 3509 * In case of the IPV6_USE_MIN_MTU socket 3510 * option, the INC_IPV6MINMTU flag to announce 3511 * a corresponding MSS during the initial 3512 * handshake. If the TCP connection is not in 3513 * the front states, just reduce the MSS being 3514 * used. This avoids the sending of TCP 3515 * segments which will be fragmented at the 3516 * IPv6 layer. 3517 */ 3518 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3519 if ((tp->t_state >= TCPS_SYN_SENT) && 3520 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3521 struct ip6_pktopts *opt; 3522 3523 opt = inp->in6p_outputopts; 3524 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3525 tp->t_maxseg > TCP6_MSS) 3526 tp->t_maxseg = TCP6_MSS; 3527 } 3528 } 3529 #endif /* INET6 */ 3530 3531 /* 3532 * Calculate effective SMSS per RFC5681 definition for a given TCP 3533 * connection at its current state, taking into account SACK and etc. 3534 */ 3535 u_int 3536 tcp_maxseg(const struct tcpcb *tp) 3537 { 3538 u_int optlen; 3539 3540 if (tp->t_flags & TF_NOOPT) 3541 return (tp->t_maxseg); 3542 3543 /* 3544 * Here we have a simplified code from tcp_addoptions(), 3545 * without a proper loop, and having most of paddings hardcoded. 3546 * We might make mistakes with padding here in some edge cases, 3547 * but this is harmless, since result of tcp_maxseg() is used 3548 * only in cwnd and ssthresh estimations. 3549 */ 3550 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3551 if (tp->t_flags & TF_RCVD_TSTMP) 3552 optlen = TCPOLEN_TSTAMP_APPA; 3553 else 3554 optlen = 0; 3555 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3556 if (tp->t_flags & TF_SIGNATURE) 3557 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3558 #endif 3559 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3560 optlen += TCPOLEN_SACKHDR; 3561 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3562 optlen = PADTCPOLEN(optlen); 3563 } 3564 } else { 3565 if (tp->t_flags & TF_REQ_TSTMP) 3566 optlen = TCPOLEN_TSTAMP_APPA; 3567 else 3568 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3569 if (tp->t_flags & TF_REQ_SCALE) 3570 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3571 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3572 if (tp->t_flags & TF_SIGNATURE) 3573 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3574 #endif 3575 if (tp->t_flags & TF_SACK_PERMIT) 3576 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3577 } 3578 #undef PAD 3579 optlen = min(optlen, TCP_MAXOLEN); 3580 return (tp->t_maxseg - optlen); 3581 } 3582 3583 3584 u_int 3585 tcp_fixed_maxseg(const struct tcpcb *tp) 3586 { 3587 int optlen; 3588 3589 if (tp->t_flags & TF_NOOPT) 3590 return (tp->t_maxseg); 3591 3592 /* 3593 * Here we have a simplified code from tcp_addoptions(), 3594 * without a proper loop, and having most of paddings hardcoded. 3595 * We only consider fixed options that we would send every 3596 * time I.e. SACK is not considered. This is important 3597 * for cc modules to figure out what the modulo of the 3598 * cwnd should be. 3599 */ 3600 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3601 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3602 if (tp->t_flags & TF_RCVD_TSTMP) 3603 optlen = TCPOLEN_TSTAMP_APPA; 3604 else 3605 optlen = 0; 3606 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3607 if (tp->t_flags & TF_SIGNATURE) 3608 optlen += PAD(TCPOLEN_SIGNATURE); 3609 #endif 3610 } else { 3611 if (tp->t_flags & TF_REQ_TSTMP) 3612 optlen = TCPOLEN_TSTAMP_APPA; 3613 else 3614 optlen = PAD(TCPOLEN_MAXSEG); 3615 if (tp->t_flags & TF_REQ_SCALE) 3616 optlen += PAD(TCPOLEN_WINDOW); 3617 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3618 if (tp->t_flags & TF_SIGNATURE) 3619 optlen += PAD(TCPOLEN_SIGNATURE); 3620 #endif 3621 if (tp->t_flags & TF_SACK_PERMIT) 3622 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3623 } 3624 #undef PAD 3625 optlen = min(optlen, TCP_MAXOLEN); 3626 return (tp->t_maxseg - optlen); 3627 } 3628 3629 3630 3631 static int 3632 sysctl_drop(SYSCTL_HANDLER_ARGS) 3633 { 3634 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3635 struct sockaddr_storage addrs[2]; 3636 struct inpcb *inp; 3637 struct tcpcb *tp; 3638 struct tcptw *tw; 3639 #ifdef INET 3640 struct sockaddr_in *fin = NULL, *lin = NULL; 3641 #endif 3642 struct epoch_tracker et; 3643 #ifdef INET6 3644 struct sockaddr_in6 *fin6, *lin6; 3645 #endif 3646 int error; 3647 3648 inp = NULL; 3649 #ifdef INET6 3650 fin6 = lin6 = NULL; 3651 #endif 3652 error = 0; 3653 3654 if (req->oldptr != NULL || req->oldlen != 0) 3655 return (EINVAL); 3656 if (req->newptr == NULL) 3657 return (EPERM); 3658 if (req->newlen < sizeof(addrs)) 3659 return (ENOMEM); 3660 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3661 if (error) 3662 return (error); 3663 3664 switch (addrs[0].ss_family) { 3665 #ifdef INET6 3666 case AF_INET6: 3667 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3668 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3669 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3670 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3671 return (EINVAL); 3672 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3673 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3674 return (EINVAL); 3675 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3676 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3677 #ifdef INET 3678 fin = (struct sockaddr_in *)&addrs[0]; 3679 lin = (struct sockaddr_in *)&addrs[1]; 3680 #endif 3681 break; 3682 } 3683 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3684 if (error) 3685 return (error); 3686 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3687 if (error) 3688 return (error); 3689 break; 3690 #endif 3691 #ifdef INET 3692 case AF_INET: 3693 fin = (struct sockaddr_in *)&addrs[0]; 3694 lin = (struct sockaddr_in *)&addrs[1]; 3695 if (fin->sin_len != sizeof(struct sockaddr_in) || 3696 lin->sin_len != sizeof(struct sockaddr_in)) 3697 return (EINVAL); 3698 break; 3699 #endif 3700 default: 3701 return (EINVAL); 3702 } 3703 NET_EPOCH_ENTER(et); 3704 switch (addrs[0].ss_family) { 3705 #ifdef INET6 3706 case AF_INET6: 3707 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3708 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3709 INPLOOKUP_WLOCKPCB, NULL); 3710 break; 3711 #endif 3712 #ifdef INET 3713 case AF_INET: 3714 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3715 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3716 break; 3717 #endif 3718 } 3719 if (inp != NULL) { 3720 if (inp->inp_flags & INP_TIMEWAIT) { 3721 /* 3722 * XXXRW: There currently exists a state where an 3723 * inpcb is present, but its timewait state has been 3724 * discarded. For now, don't allow dropping of this 3725 * type of inpcb. 3726 */ 3727 tw = intotw(inp); 3728 if (tw != NULL) 3729 tcp_twclose(tw, 0); 3730 else 3731 INP_WUNLOCK(inp); 3732 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3733 !SOLISTENING(inp->inp_socket)) { 3734 tp = intotcpcb(inp); 3735 tp = tcp_drop(tp, ECONNABORTED); 3736 if (tp != NULL) 3737 INP_WUNLOCK(inp); 3738 } else 3739 INP_WUNLOCK(inp); 3740 } else 3741 error = ESRCH; 3742 NET_EPOCH_EXIT(et); 3743 return (error); 3744 } 3745 3746 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3747 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3748 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3749 "Drop TCP connection"); 3750 3751 static int 3752 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3753 { 3754 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3755 &tcp_ctloutput_set)); 3756 } 3757 3758 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3759 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3760 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3761 "Set socket option for TCP endpoint"); 3762 3763 #ifdef KERN_TLS 3764 static int 3765 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3766 { 3767 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3768 struct sockaddr_storage addrs[2]; 3769 struct inpcb *inp; 3770 #ifdef INET 3771 struct sockaddr_in *fin = NULL, *lin = NULL; 3772 #endif 3773 struct epoch_tracker et; 3774 #ifdef INET6 3775 struct sockaddr_in6 *fin6, *lin6; 3776 #endif 3777 int error; 3778 3779 inp = NULL; 3780 #ifdef INET6 3781 fin6 = lin6 = NULL; 3782 #endif 3783 error = 0; 3784 3785 if (req->oldptr != NULL || req->oldlen != 0) 3786 return (EINVAL); 3787 if (req->newptr == NULL) 3788 return (EPERM); 3789 if (req->newlen < sizeof(addrs)) 3790 return (ENOMEM); 3791 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3792 if (error) 3793 return (error); 3794 3795 switch (addrs[0].ss_family) { 3796 #ifdef INET6 3797 case AF_INET6: 3798 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3799 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3800 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3801 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3802 return (EINVAL); 3803 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3804 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3805 return (EINVAL); 3806 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3807 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3808 #ifdef INET 3809 fin = (struct sockaddr_in *)&addrs[0]; 3810 lin = (struct sockaddr_in *)&addrs[1]; 3811 #endif 3812 break; 3813 } 3814 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3815 if (error) 3816 return (error); 3817 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3818 if (error) 3819 return (error); 3820 break; 3821 #endif 3822 #ifdef INET 3823 case AF_INET: 3824 fin = (struct sockaddr_in *)&addrs[0]; 3825 lin = (struct sockaddr_in *)&addrs[1]; 3826 if (fin->sin_len != sizeof(struct sockaddr_in) || 3827 lin->sin_len != sizeof(struct sockaddr_in)) 3828 return (EINVAL); 3829 break; 3830 #endif 3831 default: 3832 return (EINVAL); 3833 } 3834 NET_EPOCH_ENTER(et); 3835 switch (addrs[0].ss_family) { 3836 #ifdef INET6 3837 case AF_INET6: 3838 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3839 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3840 INPLOOKUP_WLOCKPCB, NULL); 3841 break; 3842 #endif 3843 #ifdef INET 3844 case AF_INET: 3845 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3846 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3847 break; 3848 #endif 3849 } 3850 NET_EPOCH_EXIT(et); 3851 if (inp != NULL) { 3852 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3853 inp->inp_socket == NULL) { 3854 error = ECONNRESET; 3855 INP_WUNLOCK(inp); 3856 } else { 3857 struct socket *so; 3858 3859 so = inp->inp_socket; 3860 soref(so); 3861 error = ktls_set_tx_mode(so, 3862 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3863 INP_WUNLOCK(inp); 3864 sorele(so); 3865 } 3866 } else 3867 error = ESRCH; 3868 return (error); 3869 } 3870 3871 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3872 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3873 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3874 "Switch TCP connection to SW TLS"); 3875 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3876 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3877 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3878 "Switch TCP connection to ifnet TLS"); 3879 #endif 3880 3881 /* 3882 * Generate a standardized TCP log line for use throughout the 3883 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3884 * allow use in the interrupt context. 3885 * 3886 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3887 * NB: The function may return NULL if memory allocation failed. 3888 * 3889 * Due to header inclusion and ordering limitations the struct ip 3890 * and ip6_hdr pointers have to be passed as void pointers. 3891 */ 3892 char * 3893 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3894 const void *ip6hdr) 3895 { 3896 3897 /* Is logging enabled? */ 3898 if (V_tcp_log_in_vain == 0) 3899 return (NULL); 3900 3901 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3902 } 3903 3904 char * 3905 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3906 const void *ip6hdr) 3907 { 3908 3909 /* Is logging enabled? */ 3910 if (tcp_log_debug == 0) 3911 return (NULL); 3912 3913 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3914 } 3915 3916 static char * 3917 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3918 const void *ip6hdr) 3919 { 3920 char *s, *sp; 3921 size_t size; 3922 #ifdef INET 3923 const struct ip *ip = (const struct ip *)ip4hdr; 3924 #endif 3925 #ifdef INET6 3926 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3927 #endif /* INET6 */ 3928 3929 /* 3930 * The log line looks like this: 3931 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3932 */ 3933 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3934 sizeof(PRINT_TH_FLAGS) + 1 + 3935 #ifdef INET6 3936 2 * INET6_ADDRSTRLEN; 3937 #else 3938 2 * INET_ADDRSTRLEN; 3939 #endif /* INET6 */ 3940 3941 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3942 if (s == NULL) 3943 return (NULL); 3944 3945 strcat(s, "TCP: ["); 3946 sp = s + strlen(s); 3947 3948 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3949 inet_ntoa_r(inc->inc_faddr, sp); 3950 sp = s + strlen(s); 3951 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3952 sp = s + strlen(s); 3953 inet_ntoa_r(inc->inc_laddr, sp); 3954 sp = s + strlen(s); 3955 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3956 #ifdef INET6 3957 } else if (inc) { 3958 ip6_sprintf(sp, &inc->inc6_faddr); 3959 sp = s + strlen(s); 3960 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3961 sp = s + strlen(s); 3962 ip6_sprintf(sp, &inc->inc6_laddr); 3963 sp = s + strlen(s); 3964 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3965 } else if (ip6 && th) { 3966 ip6_sprintf(sp, &ip6->ip6_src); 3967 sp = s + strlen(s); 3968 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3969 sp = s + strlen(s); 3970 ip6_sprintf(sp, &ip6->ip6_dst); 3971 sp = s + strlen(s); 3972 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3973 #endif /* INET6 */ 3974 #ifdef INET 3975 } else if (ip && th) { 3976 inet_ntoa_r(ip->ip_src, sp); 3977 sp = s + strlen(s); 3978 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3979 sp = s + strlen(s); 3980 inet_ntoa_r(ip->ip_dst, sp); 3981 sp = s + strlen(s); 3982 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3983 #endif /* INET */ 3984 } else { 3985 free(s, M_TCPLOG); 3986 return (NULL); 3987 } 3988 sp = s + strlen(s); 3989 if (th) 3990 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3991 if (*(s + size - 1) != '\0') 3992 panic("%s: string too long", __func__); 3993 return (s); 3994 } 3995 3996 /* 3997 * A subroutine which makes it easy to track TCP state changes with DTrace. 3998 * This function shouldn't be called for t_state initializations that don't 3999 * correspond to actual TCP state transitions. 4000 */ 4001 void 4002 tcp_state_change(struct tcpcb *tp, int newstate) 4003 { 4004 #if defined(KDTRACE_HOOKS) 4005 int pstate = tp->t_state; 4006 #endif 4007 4008 TCPSTATES_DEC(tp->t_state); 4009 TCPSTATES_INC(newstate); 4010 tp->t_state = newstate; 4011 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 4012 } 4013 4014 /* 4015 * Create an external-format (``xtcpcb'') structure using the information in 4016 * the kernel-format tcpcb structure pointed to by tp. This is done to 4017 * reduce the spew of irrelevant information over this interface, to isolate 4018 * user code from changes in the kernel structure, and potentially to provide 4019 * information-hiding if we decide that some of this information should be 4020 * hidden from users. 4021 */ 4022 void 4023 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 4024 { 4025 struct tcpcb *tp = intotcpcb(inp); 4026 struct tcptw *tw = intotw(inp); 4027 sbintime_t now; 4028 4029 bzero(xt, sizeof(*xt)); 4030 if (inp->inp_flags & INP_TIMEWAIT) { 4031 xt->t_state = TCPS_TIME_WAIT; 4032 xt->xt_encaps_port = tw->t_port; 4033 } else { 4034 xt->t_state = tp->t_state; 4035 xt->t_logstate = tp->t_logstate; 4036 xt->t_flags = tp->t_flags; 4037 xt->t_sndzerowin = tp->t_sndzerowin; 4038 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4039 xt->t_rcvoopack = tp->t_rcvoopack; 4040 xt->t_rcv_wnd = tp->rcv_wnd; 4041 xt->t_snd_wnd = tp->snd_wnd; 4042 xt->t_snd_cwnd = tp->snd_cwnd; 4043 xt->t_snd_ssthresh = tp->snd_ssthresh; 4044 xt->t_dsack_bytes = tp->t_dsack_bytes; 4045 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 4046 xt->t_dsack_pack = tp->t_dsack_pack; 4047 xt->t_maxseg = tp->t_maxseg; 4048 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4049 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4050 4051 now = getsbinuptime(); 4052 #define COPYTIMER(ttt) do { \ 4053 if (callout_active(&tp->t_timers->ttt)) \ 4054 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4055 SBT_1MS; \ 4056 else \ 4057 xt->ttt = 0; \ 4058 } while (0) 4059 COPYTIMER(tt_delack); 4060 COPYTIMER(tt_rexmt); 4061 COPYTIMER(tt_persist); 4062 COPYTIMER(tt_keep); 4063 COPYTIMER(tt_2msl); 4064 #undef COPYTIMER 4065 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4066 4067 xt->xt_encaps_port = tp->t_port; 4068 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4069 TCP_FUNCTION_NAME_LEN_MAX); 4070 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4071 TCP_CA_NAME_MAX); 4072 #ifdef TCP_BLACKBOX 4073 (void)tcp_log_get_id(tp, xt->xt_logid); 4074 #endif 4075 } 4076 4077 xt->xt_len = sizeof(struct xtcpcb); 4078 in_pcbtoxinpcb(inp, &xt->xt_inp); 4079 if (inp->inp_socket == NULL) 4080 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4081 } 4082 4083 void 4084 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4085 { 4086 uint32_t bit, i; 4087 4088 if ((tp == NULL) || 4089 (status > TCP_EI_STATUS_MAX_VALUE) || 4090 (status == 0)) { 4091 /* Invalid */ 4092 return; 4093 } 4094 if (status > (sizeof(uint32_t) * 8)) { 4095 /* Should this be a KASSERT? */ 4096 return; 4097 } 4098 bit = 1U << (status - 1); 4099 if (bit & tp->t_end_info_status) { 4100 /* already logged */ 4101 return; 4102 } 4103 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4104 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4105 tp->t_end_info_bytes[i] = status; 4106 tp->t_end_info_status |= bit; 4107 break; 4108 } 4109 } 4110 } 4111 4112 int 4113 tcp_can_enable_pacing(void) 4114 { 4115 4116 if ((tcp_pacing_limit == -1) || 4117 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4118 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4119 shadow_num_connections = number_of_tcp_connections_pacing; 4120 return (1); 4121 } else { 4122 return (0); 4123 } 4124 } 4125 4126 static uint8_t tcp_pacing_warning = 0; 4127 4128 void 4129 tcp_decrement_paced_conn(void) 4130 { 4131 uint32_t ret; 4132 4133 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4134 shadow_num_connections = number_of_tcp_connections_pacing; 4135 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4136 if (ret == 0) { 4137 if (tcp_pacing_limit != -1) { 4138 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4139 tcp_pacing_limit = 0; 4140 } else if (tcp_pacing_warning == 0) { 4141 printf("Warning pacing count is invalid, invalid decrement\n"); 4142 tcp_pacing_warning = 1; 4143 } 4144 } 4145 } 4146