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 void tcp_mtudisc(struct inpcb *, int); 379 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 380 void *ip4hdr, const void *ip6hdr); 381 382 static struct tcp_function_block tcp_def_funcblk = { 383 .tfb_tcp_block_name = "freebsd", 384 .tfb_tcp_output = tcp_output, 385 .tfb_tcp_do_segment = tcp_do_segment, 386 .tfb_tcp_ctloutput = tcp_default_ctloutput, 387 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 388 .tfb_tcp_fb_init = tcp_default_fb_init, 389 .tfb_tcp_fb_fini = tcp_default_fb_fini, 390 }; 391 392 static int tcp_fb_cnt = 0; 393 struct tcp_funchead t_functions; 394 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 395 396 void 397 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 398 { 399 TCPSTAT_INC(tcps_dsack_count); 400 tp->t_dsack_pack++; 401 if (tlp == 0) { 402 if (SEQ_GT(end, start)) { 403 tp->t_dsack_bytes += (end - start); 404 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 405 } else { 406 tp->t_dsack_tlp_bytes += (start - end); 407 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 408 } 409 } else { 410 if (SEQ_GT(end, start)) { 411 tp->t_dsack_bytes += (end - start); 412 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 413 } else { 414 tp->t_dsack_tlp_bytes += (start - end); 415 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 416 } 417 } 418 } 419 420 static struct tcp_function_block * 421 find_tcp_functions_locked(struct tcp_function_set *fs) 422 { 423 struct tcp_function *f; 424 struct tcp_function_block *blk=NULL; 425 426 TAILQ_FOREACH(f, &t_functions, tf_next) { 427 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 428 blk = f->tf_fb; 429 break; 430 } 431 } 432 return(blk); 433 } 434 435 static struct tcp_function_block * 436 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 437 { 438 struct tcp_function_block *rblk=NULL; 439 struct tcp_function *f; 440 441 TAILQ_FOREACH(f, &t_functions, tf_next) { 442 if (f->tf_fb == blk) { 443 rblk = blk; 444 if (s) { 445 *s = f; 446 } 447 break; 448 } 449 } 450 return (rblk); 451 } 452 453 struct tcp_function_block * 454 find_and_ref_tcp_functions(struct tcp_function_set *fs) 455 { 456 struct tcp_function_block *blk; 457 458 rw_rlock(&tcp_function_lock); 459 blk = find_tcp_functions_locked(fs); 460 if (blk) 461 refcount_acquire(&blk->tfb_refcnt); 462 rw_runlock(&tcp_function_lock); 463 return(blk); 464 } 465 466 struct tcp_function_block * 467 find_and_ref_tcp_fb(struct tcp_function_block *blk) 468 { 469 struct tcp_function_block *rblk; 470 471 rw_rlock(&tcp_function_lock); 472 rblk = find_tcp_fb_locked(blk, NULL); 473 if (rblk) 474 refcount_acquire(&rblk->tfb_refcnt); 475 rw_runlock(&tcp_function_lock); 476 return(rblk); 477 } 478 479 /* Find a matching alias for the given tcp_function_block. */ 480 int 481 find_tcp_function_alias(struct tcp_function_block *blk, 482 struct tcp_function_set *fs) 483 { 484 struct tcp_function *f; 485 int found; 486 487 found = 0; 488 rw_rlock(&tcp_function_lock); 489 TAILQ_FOREACH(f, &t_functions, tf_next) { 490 if ((f->tf_fb == blk) && 491 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 492 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 493 /* Matching function block with different name. */ 494 strncpy(fs->function_set_name, f->tf_name, 495 TCP_FUNCTION_NAME_LEN_MAX); 496 found = 1; 497 break; 498 } 499 } 500 /* Null terminate the string appropriately. */ 501 if (found) { 502 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 503 } else { 504 fs->function_set_name[0] = '\0'; 505 } 506 rw_runlock(&tcp_function_lock); 507 return (found); 508 } 509 510 static struct tcp_function_block * 511 find_and_ref_tcp_default_fb(void) 512 { 513 struct tcp_function_block *rblk; 514 515 rw_rlock(&tcp_function_lock); 516 rblk = tcp_func_set_ptr; 517 refcount_acquire(&rblk->tfb_refcnt); 518 rw_runlock(&tcp_function_lock); 519 return (rblk); 520 } 521 522 void 523 tcp_switch_back_to_default(struct tcpcb *tp) 524 { 525 struct tcp_function_block *tfb; 526 527 KASSERT(tp->t_fb != &tcp_def_funcblk, 528 ("%s: called by the built-in default stack", __func__)); 529 530 /* 531 * Release the old stack. This function will either find a new one 532 * or panic. 533 */ 534 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 535 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 536 refcount_release(&tp->t_fb->tfb_refcnt); 537 538 /* 539 * Now, we'll find a new function block to use. 540 * Start by trying the current user-selected 541 * default, unless this stack is the user-selected 542 * default. 543 */ 544 tfb = find_and_ref_tcp_default_fb(); 545 if (tfb == tp->t_fb) { 546 refcount_release(&tfb->tfb_refcnt); 547 tfb = NULL; 548 } 549 /* Does the stack accept this connection? */ 550 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 551 (*tfb->tfb_tcp_handoff_ok)(tp)) { 552 refcount_release(&tfb->tfb_refcnt); 553 tfb = NULL; 554 } 555 /* Try to use that stack. */ 556 if (tfb != NULL) { 557 /* Initialize the new stack. If it succeeds, we are done. */ 558 tp->t_fb = tfb; 559 if (tp->t_fb->tfb_tcp_fb_init == NULL || 560 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 561 return; 562 563 /* 564 * Initialization failed. Release the reference count on 565 * the stack. 566 */ 567 refcount_release(&tfb->tfb_refcnt); 568 } 569 570 /* 571 * If that wasn't feasible, use the built-in default 572 * stack which is not allowed to reject anyone. 573 */ 574 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 575 if (tfb == NULL) { 576 /* there always should be a default */ 577 panic("Can't refer to tcp_def_funcblk"); 578 } 579 if (tfb->tfb_tcp_handoff_ok != NULL) { 580 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 581 /* The default stack cannot say no */ 582 panic("Default stack rejects a new session?"); 583 } 584 } 585 tp->t_fb = tfb; 586 if (tp->t_fb->tfb_tcp_fb_init != NULL && 587 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 588 /* The default stack cannot fail */ 589 panic("Default stack initialization failed"); 590 } 591 } 592 593 static void 594 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 595 const struct sockaddr *sa, void *ctx) 596 { 597 struct ip *iph; 598 #ifdef INET6 599 struct ip6_hdr *ip6; 600 #endif 601 struct udphdr *uh; 602 struct tcphdr *th; 603 int thlen; 604 uint16_t port; 605 606 TCPSTAT_INC(tcps_tunneled_pkts); 607 if ((m->m_flags & M_PKTHDR) == 0) { 608 /* Can't handle one that is not a pkt hdr */ 609 TCPSTAT_INC(tcps_tunneled_errs); 610 goto out; 611 } 612 thlen = sizeof(struct tcphdr); 613 if (m->m_len < off + sizeof(struct udphdr) + thlen && 614 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 615 TCPSTAT_INC(tcps_tunneled_errs); 616 goto out; 617 } 618 iph = mtod(m, struct ip *); 619 uh = (struct udphdr *)((caddr_t)iph + off); 620 th = (struct tcphdr *)(uh + 1); 621 thlen = th->th_off << 2; 622 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 623 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 624 if (m == NULL) { 625 TCPSTAT_INC(tcps_tunneled_errs); 626 goto out; 627 } else { 628 iph = mtod(m, struct ip *); 629 uh = (struct udphdr *)((caddr_t)iph + off); 630 th = (struct tcphdr *)(uh + 1); 631 } 632 } 633 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 634 bcopy(th, uh, m->m_len - off); 635 m->m_len -= sizeof(struct udphdr); 636 m->m_pkthdr.len -= sizeof(struct udphdr); 637 /* 638 * We use the same algorithm for 639 * both UDP and TCP for c-sum. So 640 * the code in tcp_input will skip 641 * the checksum. So we do nothing 642 * with the flag (m->m_pkthdr.csum_flags). 643 */ 644 switch (iph->ip_v) { 645 #ifdef INET 646 case IPVERSION: 647 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 648 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 649 break; 650 #endif 651 #ifdef INET6 652 case IPV6_VERSION >> 4: 653 ip6 = mtod(m, struct ip6_hdr *); 654 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 655 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 656 break; 657 #endif 658 default: 659 goto out; 660 break; 661 } 662 return; 663 out: 664 m_freem(m); 665 } 666 667 static int 668 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 669 { 670 int error=ENOENT; 671 struct tcp_function_set fs; 672 struct tcp_function_block *blk; 673 674 memset(&fs, 0, sizeof(fs)); 675 rw_rlock(&tcp_function_lock); 676 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 677 if (blk) { 678 /* Found him */ 679 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 680 fs.pcbcnt = blk->tfb_refcnt; 681 } 682 rw_runlock(&tcp_function_lock); 683 error = sysctl_handle_string(oidp, fs.function_set_name, 684 sizeof(fs.function_set_name), req); 685 686 /* Check for error or no change */ 687 if (error != 0 || req->newptr == NULL) 688 return(error); 689 690 rw_wlock(&tcp_function_lock); 691 blk = find_tcp_functions_locked(&fs); 692 if ((blk == NULL) || 693 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 694 error = ENOENT; 695 goto done; 696 } 697 tcp_func_set_ptr = blk; 698 done: 699 rw_wunlock(&tcp_function_lock); 700 return (error); 701 } 702 703 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 704 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 705 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 706 "Set/get the default TCP functions"); 707 708 static int 709 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 710 { 711 int error, cnt, linesz; 712 struct tcp_function *f; 713 char *buffer, *cp; 714 size_t bufsz, outsz; 715 bool alias; 716 717 cnt = 0; 718 rw_rlock(&tcp_function_lock); 719 TAILQ_FOREACH(f, &t_functions, tf_next) { 720 cnt++; 721 } 722 rw_runlock(&tcp_function_lock); 723 724 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 725 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 726 727 error = 0; 728 cp = buffer; 729 730 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 731 "Alias", "PCB count"); 732 cp += linesz; 733 bufsz -= linesz; 734 outsz = linesz; 735 736 rw_rlock(&tcp_function_lock); 737 TAILQ_FOREACH(f, &t_functions, tf_next) { 738 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 739 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 740 f->tf_fb->tfb_tcp_block_name, 741 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 742 alias ? f->tf_name : "-", 743 f->tf_fb->tfb_refcnt); 744 if (linesz >= bufsz) { 745 error = EOVERFLOW; 746 break; 747 } 748 cp += linesz; 749 bufsz -= linesz; 750 outsz += linesz; 751 } 752 rw_runlock(&tcp_function_lock); 753 if (error == 0) 754 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 755 free(buffer, M_TEMP); 756 return (error); 757 } 758 759 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 760 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 761 NULL, 0, sysctl_net_inet_list_available, "A", 762 "list available TCP Function sets"); 763 764 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 765 766 #ifdef INET 767 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 768 #define V_udp4_tun_socket VNET(udp4_tun_socket) 769 #endif 770 #ifdef INET6 771 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 772 #define V_udp6_tun_socket VNET(udp6_tun_socket) 773 #endif 774 775 static void 776 tcp_over_udp_stop(void) 777 { 778 /* 779 * This function assumes sysctl caller holds inp_rinfo_lock() 780 * for writing! 781 */ 782 #ifdef INET 783 if (V_udp4_tun_socket != NULL) { 784 soclose(V_udp4_tun_socket); 785 V_udp4_tun_socket = NULL; 786 } 787 #endif 788 #ifdef INET6 789 if (V_udp6_tun_socket != NULL) { 790 soclose(V_udp6_tun_socket); 791 V_udp6_tun_socket = NULL; 792 } 793 #endif 794 } 795 796 static int 797 tcp_over_udp_start(void) 798 { 799 uint16_t port; 800 int ret; 801 #ifdef INET 802 struct sockaddr_in sin; 803 #endif 804 #ifdef INET6 805 struct sockaddr_in6 sin6; 806 #endif 807 /* 808 * This function assumes sysctl caller holds inp_info_rlock() 809 * for writing! 810 */ 811 port = V_tcp_udp_tunneling_port; 812 if (ntohs(port) == 0) { 813 /* Must have a port set */ 814 return (EINVAL); 815 } 816 #ifdef INET 817 if (V_udp4_tun_socket != NULL) { 818 /* Already running -- must stop first */ 819 return (EALREADY); 820 } 821 #endif 822 #ifdef INET6 823 if (V_udp6_tun_socket != NULL) { 824 /* Already running -- must stop first */ 825 return (EALREADY); 826 } 827 #endif 828 #ifdef INET 829 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 830 SOCK_DGRAM, IPPROTO_UDP, 831 curthread->td_ucred, curthread))) { 832 tcp_over_udp_stop(); 833 return (ret); 834 } 835 /* Call the special UDP hook. */ 836 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 837 tcp_recv_udp_tunneled_packet, 838 tcp_ctlinput_viaudp, 839 NULL))) { 840 tcp_over_udp_stop(); 841 return (ret); 842 } 843 /* Ok, we have a socket, bind it to the port. */ 844 memset(&sin, 0, sizeof(struct sockaddr_in)); 845 sin.sin_len = sizeof(struct sockaddr_in); 846 sin.sin_family = AF_INET; 847 sin.sin_port = htons(port); 848 if ((ret = sobind(V_udp4_tun_socket, 849 (struct sockaddr *)&sin, curthread))) { 850 tcp_over_udp_stop(); 851 return (ret); 852 } 853 #endif 854 #ifdef INET6 855 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 856 SOCK_DGRAM, IPPROTO_UDP, 857 curthread->td_ucred, curthread))) { 858 tcp_over_udp_stop(); 859 return (ret); 860 } 861 /* Call the special UDP hook. */ 862 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 863 tcp_recv_udp_tunneled_packet, 864 tcp6_ctlinput_viaudp, 865 NULL))) { 866 tcp_over_udp_stop(); 867 return (ret); 868 } 869 /* Ok, we have a socket, bind it to the port. */ 870 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 871 sin6.sin6_len = sizeof(struct sockaddr_in6); 872 sin6.sin6_family = AF_INET6; 873 sin6.sin6_port = htons(port); 874 if ((ret = sobind(V_udp6_tun_socket, 875 (struct sockaddr *)&sin6, curthread))) { 876 tcp_over_udp_stop(); 877 return (ret); 878 } 879 #endif 880 return (0); 881 } 882 883 static int 884 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 885 { 886 int error; 887 uint32_t old, new; 888 889 old = V_tcp_udp_tunneling_port; 890 new = old; 891 error = sysctl_handle_int(oidp, &new, 0, req); 892 if ((error == 0) && 893 (req->newptr != NULL)) { 894 if ((new < TCP_TUNNELING_PORT_MIN) || 895 (new > TCP_TUNNELING_PORT_MAX)) { 896 error = EINVAL; 897 } else { 898 V_tcp_udp_tunneling_port = new; 899 if (old != 0) { 900 tcp_over_udp_stop(); 901 } 902 if (new != 0) { 903 error = tcp_over_udp_start(); 904 } 905 } 906 } 907 return (error); 908 } 909 910 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 911 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 912 &VNET_NAME(tcp_udp_tunneling_port), 913 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 914 "Tunneling port for tcp over udp"); 915 916 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 917 918 static int 919 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 920 { 921 int error, new; 922 923 new = V_tcp_udp_tunneling_overhead; 924 error = sysctl_handle_int(oidp, &new, 0, req); 925 if (error == 0 && req->newptr) { 926 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 927 (new > TCP_TUNNELING_OVERHEAD_MAX)) 928 error = EINVAL; 929 else 930 V_tcp_udp_tunneling_overhead = new; 931 } 932 return (error); 933 } 934 935 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 936 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 937 &VNET_NAME(tcp_udp_tunneling_overhead), 938 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 939 "MSS reduction when using tcp over udp"); 940 941 /* 942 * Exports one (struct tcp_function_info) for each alias/name. 943 */ 944 static int 945 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 946 { 947 int cnt, error; 948 struct tcp_function *f; 949 struct tcp_function_info tfi; 950 951 /* 952 * We don't allow writes. 953 */ 954 if (req->newptr != NULL) 955 return (EINVAL); 956 957 /* 958 * Wire the old buffer so we can directly copy the functions to 959 * user space without dropping the lock. 960 */ 961 if (req->oldptr != NULL) { 962 error = sysctl_wire_old_buffer(req, 0); 963 if (error) 964 return (error); 965 } 966 967 /* 968 * Walk the list and copy out matching entries. If INVARIANTS 969 * is compiled in, also walk the list to verify the length of 970 * the list matches what we have recorded. 971 */ 972 rw_rlock(&tcp_function_lock); 973 974 cnt = 0; 975 #ifndef INVARIANTS 976 if (req->oldptr == NULL) { 977 cnt = tcp_fb_cnt; 978 goto skip_loop; 979 } 980 #endif 981 TAILQ_FOREACH(f, &t_functions, tf_next) { 982 #ifdef INVARIANTS 983 cnt++; 984 #endif 985 if (req->oldptr != NULL) { 986 bzero(&tfi, sizeof(tfi)); 987 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 988 tfi.tfi_id = f->tf_fb->tfb_id; 989 (void)strlcpy(tfi.tfi_alias, f->tf_name, 990 sizeof(tfi.tfi_alias)); 991 (void)strlcpy(tfi.tfi_name, 992 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 993 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 994 /* 995 * Don't stop on error, as that is the 996 * mechanism we use to accumulate length 997 * information if the buffer was too short. 998 */ 999 } 1000 } 1001 KASSERT(cnt == tcp_fb_cnt, 1002 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1003 #ifndef INVARIANTS 1004 skip_loop: 1005 #endif 1006 rw_runlock(&tcp_function_lock); 1007 if (req->oldptr == NULL) 1008 error = SYSCTL_OUT(req, NULL, 1009 (cnt + 1) * sizeof(struct tcp_function_info)); 1010 1011 return (error); 1012 } 1013 1014 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1015 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1016 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1017 "List TCP function block name-to-ID mappings"); 1018 1019 /* 1020 * tfb_tcp_handoff_ok() function for the default stack. 1021 * Note that we'll basically try to take all comers. 1022 */ 1023 static int 1024 tcp_default_handoff_ok(struct tcpcb *tp) 1025 { 1026 1027 return (0); 1028 } 1029 1030 /* 1031 * tfb_tcp_fb_init() function for the default stack. 1032 * 1033 * This handles making sure we have appropriate timers set if you are 1034 * transitioning a socket that has some amount of setup done. 1035 * 1036 * The init() fuction from the default can *never* return non-zero i.e. 1037 * it is required to always succeed since it is the stack of last resort! 1038 */ 1039 static int 1040 tcp_default_fb_init(struct tcpcb *tp) 1041 { 1042 1043 struct socket *so; 1044 1045 INP_WLOCK_ASSERT(tp->t_inpcb); 1046 1047 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1048 ("%s: connection %p in unexpected state %d", __func__, tp, 1049 tp->t_state)); 1050 1051 /* 1052 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1053 * know what to do for unexpected states (which includes TIME_WAIT). 1054 */ 1055 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1056 return (0); 1057 1058 /* 1059 * Make sure some kind of transmission timer is set if there is 1060 * outstanding data. 1061 */ 1062 so = tp->t_inpcb->inp_socket; 1063 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1064 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1065 tcp_timer_active(tp, TT_PERSIST))) { 1066 /* 1067 * If the session has established and it looks like it should 1068 * be in the persist state, set the persist timer. Otherwise, 1069 * set the retransmit timer. 1070 */ 1071 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1072 (int32_t)(tp->snd_nxt - tp->snd_una) < 1073 (int32_t)sbavail(&so->so_snd)) 1074 tcp_setpersist(tp); 1075 else 1076 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1077 } 1078 1079 /* All non-embryonic sessions get a keepalive timer. */ 1080 if (!tcp_timer_active(tp, TT_KEEP)) 1081 tcp_timer_activate(tp, TT_KEEP, 1082 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1083 TP_KEEPINIT(tp)); 1084 1085 /* 1086 * Make sure critical variables are initialized 1087 * if transitioning while in Recovery. 1088 */ 1089 if IN_FASTRECOVERY(tp->t_flags) { 1090 if (tp->sackhint.recover_fs == 0) 1091 tp->sackhint.recover_fs = max(1, 1092 tp->snd_nxt - tp->snd_una); 1093 } 1094 1095 return (0); 1096 } 1097 1098 /* 1099 * tfb_tcp_fb_fini() function for the default stack. 1100 * 1101 * This changes state as necessary (or prudent) to prepare for another stack 1102 * to assume responsibility for the connection. 1103 */ 1104 static void 1105 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1106 { 1107 1108 INP_WLOCK_ASSERT(tp->t_inpcb); 1109 return; 1110 } 1111 1112 /* 1113 * Target size of TCP PCB hash tables. Must be a power of two. 1114 * 1115 * Note that this can be overridden by the kernel environment 1116 * variable net.inet.tcp.tcbhashsize 1117 */ 1118 #ifndef TCBHASHSIZE 1119 #define TCBHASHSIZE 0 1120 #endif 1121 1122 /* 1123 * XXX 1124 * Callouts should be moved into struct tcp directly. They are currently 1125 * separate because the tcpcb structure is exported to userland for sysctl 1126 * parsing purposes, which do not know about callouts. 1127 */ 1128 struct tcpcb_mem { 1129 struct tcpcb tcb; 1130 struct tcp_timer tt; 1131 struct cc_var ccv; 1132 #ifdef TCP_HHOOK 1133 struct osd osd; 1134 #endif 1135 }; 1136 1137 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1138 #define V_tcpcb_zone VNET(tcpcb_zone) 1139 1140 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1141 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1142 1143 static struct mtx isn_mtx; 1144 1145 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1146 #define ISN_LOCK() mtx_lock(&isn_mtx) 1147 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1148 1149 /* 1150 * TCP initialization. 1151 */ 1152 static void 1153 tcp_zone_change(void *tag) 1154 { 1155 1156 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 1157 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1158 tcp_tw_zone_change(); 1159 } 1160 1161 static int 1162 tcp_inpcb_init(void *mem, int size, int flags) 1163 { 1164 struct inpcb *inp = mem; 1165 1166 INP_LOCK_INIT(inp, "inp", "tcpinp"); 1167 return (0); 1168 } 1169 1170 /* 1171 * Take a value and get the next power of 2 that doesn't overflow. 1172 * Used to size the tcp_inpcb hash buckets. 1173 */ 1174 static int 1175 maketcp_hashsize(int size) 1176 { 1177 int hashsize; 1178 1179 /* 1180 * auto tune. 1181 * get the next power of 2 higher than maxsockets. 1182 */ 1183 hashsize = 1 << fls(size); 1184 /* catch overflow, and just go one power of 2 smaller */ 1185 if (hashsize < size) { 1186 hashsize = 1 << (fls(size) - 1); 1187 } 1188 return (hashsize); 1189 } 1190 1191 static volatile int next_tcp_stack_id = 1; 1192 1193 /* 1194 * Register a TCP function block with the name provided in the names 1195 * array. (Note that this function does NOT automatically register 1196 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1197 * explicitly include blk->tfb_tcp_block_name in the list of names if 1198 * you wish to register the stack with that name.) 1199 * 1200 * Either all name registrations will succeed or all will fail. If 1201 * a name registration fails, the function will update the num_names 1202 * argument to point to the array index of the name that encountered 1203 * the failure. 1204 * 1205 * Returns 0 on success, or an error code on failure. 1206 */ 1207 int 1208 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1209 const char *names[], int *num_names) 1210 { 1211 struct tcp_function *n; 1212 struct tcp_function_set fs; 1213 int error, i; 1214 1215 KASSERT(names != NULL && *num_names > 0, 1216 ("%s: Called with 0-length name list", __func__)); 1217 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1218 KASSERT(rw_initialized(&tcp_function_lock), 1219 ("%s: called too early", __func__)); 1220 1221 if ((blk->tfb_tcp_output == NULL) || 1222 (blk->tfb_tcp_do_segment == NULL) || 1223 (blk->tfb_tcp_ctloutput == NULL) || 1224 (strlen(blk->tfb_tcp_block_name) == 0)) { 1225 /* 1226 * These functions are required and you 1227 * need a name. 1228 */ 1229 *num_names = 0; 1230 return (EINVAL); 1231 } 1232 if (blk->tfb_tcp_timer_stop_all || 1233 blk->tfb_tcp_timer_activate || 1234 blk->tfb_tcp_timer_active || 1235 blk->tfb_tcp_timer_stop) { 1236 /* 1237 * If you define one timer function you 1238 * must have them all. 1239 */ 1240 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1241 (blk->tfb_tcp_timer_activate == NULL) || 1242 (blk->tfb_tcp_timer_active == NULL) || 1243 (blk->tfb_tcp_timer_stop == NULL)) { 1244 *num_names = 0; 1245 return (EINVAL); 1246 } 1247 } 1248 1249 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1250 *num_names = 0; 1251 return (EINVAL); 1252 } 1253 1254 refcount_init(&blk->tfb_refcnt, 0); 1255 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1256 for (i = 0; i < *num_names; i++) { 1257 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1258 if (n == NULL) { 1259 error = ENOMEM; 1260 goto cleanup; 1261 } 1262 n->tf_fb = blk; 1263 1264 (void)strlcpy(fs.function_set_name, names[i], 1265 sizeof(fs.function_set_name)); 1266 rw_wlock(&tcp_function_lock); 1267 if (find_tcp_functions_locked(&fs) != NULL) { 1268 /* Duplicate name space not allowed */ 1269 rw_wunlock(&tcp_function_lock); 1270 free(n, M_TCPFUNCTIONS); 1271 error = EALREADY; 1272 goto cleanup; 1273 } 1274 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1275 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1276 tcp_fb_cnt++; 1277 rw_wunlock(&tcp_function_lock); 1278 } 1279 return(0); 1280 1281 cleanup: 1282 /* 1283 * Deregister the names we just added. Because registration failed 1284 * for names[i], we don't need to deregister that name. 1285 */ 1286 *num_names = i; 1287 rw_wlock(&tcp_function_lock); 1288 while (--i >= 0) { 1289 TAILQ_FOREACH(n, &t_functions, tf_next) { 1290 if (!strncmp(n->tf_name, names[i], 1291 TCP_FUNCTION_NAME_LEN_MAX)) { 1292 TAILQ_REMOVE(&t_functions, n, tf_next); 1293 tcp_fb_cnt--; 1294 n->tf_fb = NULL; 1295 free(n, M_TCPFUNCTIONS); 1296 break; 1297 } 1298 } 1299 } 1300 rw_wunlock(&tcp_function_lock); 1301 return (error); 1302 } 1303 1304 /* 1305 * Register a TCP function block using the name provided in the name 1306 * argument. 1307 * 1308 * Returns 0 on success, or an error code on failure. 1309 */ 1310 int 1311 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1312 int wait) 1313 { 1314 const char *name_list[1]; 1315 int num_names, rv; 1316 1317 num_names = 1; 1318 if (name != NULL) 1319 name_list[0] = name; 1320 else 1321 name_list[0] = blk->tfb_tcp_block_name; 1322 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1323 return (rv); 1324 } 1325 1326 /* 1327 * Register a TCP function block using the name defined in 1328 * blk->tfb_tcp_block_name. 1329 * 1330 * Returns 0 on success, or an error code on failure. 1331 */ 1332 int 1333 register_tcp_functions(struct tcp_function_block *blk, int wait) 1334 { 1335 1336 return (register_tcp_functions_as_name(blk, NULL, wait)); 1337 } 1338 1339 /* 1340 * Deregister all names associated with a function block. This 1341 * functionally removes the function block from use within the system. 1342 * 1343 * When called with a true quiesce argument, mark the function block 1344 * as being removed so no more stacks will use it and determine 1345 * whether the removal would succeed. 1346 * 1347 * When called with a false quiesce argument, actually attempt the 1348 * removal. 1349 * 1350 * When called with a force argument, attempt to switch all TCBs to 1351 * use the default stack instead of returning EBUSY. 1352 * 1353 * Returns 0 on success (or if the removal would succeed, or an error 1354 * code on failure. 1355 */ 1356 int 1357 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1358 bool force) 1359 { 1360 struct tcp_function *f; 1361 1362 if (blk == &tcp_def_funcblk) { 1363 /* You can't un-register the default */ 1364 return (EPERM); 1365 } 1366 rw_wlock(&tcp_function_lock); 1367 if (blk == tcp_func_set_ptr) { 1368 /* You can't free the current default */ 1369 rw_wunlock(&tcp_function_lock); 1370 return (EBUSY); 1371 } 1372 /* Mark the block so no more stacks can use it. */ 1373 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1374 /* 1375 * If TCBs are still attached to the stack, attempt to switch them 1376 * to the default stack. 1377 */ 1378 if (force && blk->tfb_refcnt) { 1379 struct inpcb *inp; 1380 struct tcpcb *tp; 1381 VNET_ITERATOR_DECL(vnet_iter); 1382 1383 rw_wunlock(&tcp_function_lock); 1384 1385 VNET_LIST_RLOCK(); 1386 VNET_FOREACH(vnet_iter) { 1387 CURVNET_SET(vnet_iter); 1388 INP_INFO_WLOCK(&V_tcbinfo); 1389 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1390 INP_WLOCK(inp); 1391 if (inp->inp_flags & INP_TIMEWAIT) { 1392 INP_WUNLOCK(inp); 1393 continue; 1394 } 1395 tp = intotcpcb(inp); 1396 if (tp == NULL || tp->t_fb != blk) { 1397 INP_WUNLOCK(inp); 1398 continue; 1399 } 1400 tcp_switch_back_to_default(tp); 1401 INP_WUNLOCK(inp); 1402 } 1403 INP_INFO_WUNLOCK(&V_tcbinfo); 1404 CURVNET_RESTORE(); 1405 } 1406 VNET_LIST_RUNLOCK(); 1407 1408 rw_wlock(&tcp_function_lock); 1409 } 1410 if (blk->tfb_refcnt) { 1411 /* TCBs still attached. */ 1412 rw_wunlock(&tcp_function_lock); 1413 return (EBUSY); 1414 } 1415 if (quiesce) { 1416 /* Skip removal. */ 1417 rw_wunlock(&tcp_function_lock); 1418 return (0); 1419 } 1420 /* Remove any function names that map to this function block. */ 1421 while (find_tcp_fb_locked(blk, &f) != NULL) { 1422 TAILQ_REMOVE(&t_functions, f, tf_next); 1423 tcp_fb_cnt--; 1424 f->tf_fb = NULL; 1425 free(f, M_TCPFUNCTIONS); 1426 } 1427 rw_wunlock(&tcp_function_lock); 1428 return (0); 1429 } 1430 1431 void 1432 tcp_init(void) 1433 { 1434 const char *tcbhash_tuneable; 1435 int hashsize; 1436 1437 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1438 1439 #ifdef TCP_HHOOK 1440 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1441 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1442 printf("%s: WARNING: unable to register helper hook\n", __func__); 1443 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1444 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1445 printf("%s: WARNING: unable to register helper hook\n", __func__); 1446 #endif 1447 #ifdef STATS 1448 if (tcp_stats_init()) 1449 printf("%s: WARNING: unable to initialise TCP stats\n", 1450 __func__); 1451 #endif 1452 hashsize = TCBHASHSIZE; 1453 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1454 if (hashsize == 0) { 1455 /* 1456 * Auto tune the hash size based on maxsockets. 1457 * A perfect hash would have a 1:1 mapping 1458 * (hashsize = maxsockets) however it's been 1459 * suggested that O(2) average is better. 1460 */ 1461 hashsize = maketcp_hashsize(maxsockets / 4); 1462 /* 1463 * Our historical default is 512, 1464 * do not autotune lower than this. 1465 */ 1466 if (hashsize < 512) 1467 hashsize = 512; 1468 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1469 printf("%s: %s auto tuned to %d\n", __func__, 1470 tcbhash_tuneable, hashsize); 1471 } 1472 /* 1473 * We require a hashsize to be a power of two. 1474 * Previously if it was not a power of two we would just reset it 1475 * back to 512, which could be a nasty surprise if you did not notice 1476 * the error message. 1477 * Instead what we do is clip it to the closest power of two lower 1478 * than the specified hash value. 1479 */ 1480 if (!powerof2(hashsize)) { 1481 int oldhashsize = hashsize; 1482 1483 hashsize = maketcp_hashsize(hashsize); 1484 /* prevent absurdly low value */ 1485 if (hashsize < 16) 1486 hashsize = 16; 1487 printf("%s: WARNING: TCB hash size not a power of 2, " 1488 "clipped from %d to %d.\n", __func__, oldhashsize, 1489 hashsize); 1490 } 1491 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1492 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1493 1494 /* 1495 * These have to be type stable for the benefit of the timers. 1496 */ 1497 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1498 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1499 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1500 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1501 1502 tcp_tw_init(); 1503 syncache_init(); 1504 tcp_hc_init(); 1505 1506 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1507 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1508 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1509 1510 tcp_fastopen_init(); 1511 1512 /* Skip initialization of globals for non-default instances. */ 1513 if (!IS_DEFAULT_VNET(curvnet)) 1514 return; 1515 1516 tcp_reass_global_init(); 1517 1518 /* XXX virtualize those bellow? */ 1519 tcp_delacktime = TCPTV_DELACK; 1520 tcp_keepinit = TCPTV_KEEP_INIT; 1521 tcp_keepidle = TCPTV_KEEP_IDLE; 1522 tcp_keepintvl = TCPTV_KEEPINTVL; 1523 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1524 tcp_msl = TCPTV_MSL; 1525 tcp_rexmit_initial = TCPTV_RTOBASE; 1526 if (tcp_rexmit_initial < 1) 1527 tcp_rexmit_initial = 1; 1528 tcp_rexmit_min = TCPTV_MIN; 1529 if (tcp_rexmit_min < 1) 1530 tcp_rexmit_min = 1; 1531 tcp_persmin = TCPTV_PERSMIN; 1532 tcp_persmax = TCPTV_PERSMAX; 1533 tcp_rexmit_slop = TCPTV_CPU_VAR; 1534 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1535 tcp_tcbhashsize = hashsize; 1536 1537 /* Setup the tcp function block list */ 1538 TAILQ_INIT(&t_functions); 1539 rw_init(&tcp_function_lock, "tcp_func_lock"); 1540 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1541 #ifdef TCP_BLACKBOX 1542 /* Initialize the TCP logging data. */ 1543 tcp_log_init(); 1544 #endif 1545 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1546 1547 if (tcp_soreceive_stream) { 1548 #ifdef INET 1549 tcp_usrreqs.pru_soreceive = soreceive_stream; 1550 #endif 1551 #ifdef INET6 1552 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1553 #endif /* INET6 */ 1554 } 1555 1556 #ifdef INET6 1557 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1558 #else /* INET6 */ 1559 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1560 #endif /* INET6 */ 1561 if (max_protohdr < TCP_MINPROTOHDR) 1562 max_protohdr = TCP_MINPROTOHDR; 1563 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1564 panic("tcp_init"); 1565 #undef TCP_MINPROTOHDR 1566 1567 ISN_LOCK_INIT(); 1568 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1569 SHUTDOWN_PRI_DEFAULT); 1570 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1571 EVENTHANDLER_PRI_ANY); 1572 1573 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1574 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1575 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1576 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1577 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1578 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1579 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1580 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1581 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1582 #ifdef TCPPCAP 1583 tcp_pcap_init(); 1584 #endif 1585 } 1586 1587 #ifdef VIMAGE 1588 static void 1589 tcp_destroy(void *unused __unused) 1590 { 1591 int n; 1592 #ifdef TCP_HHOOK 1593 int error; 1594 #endif 1595 1596 /* 1597 * All our processes are gone, all our sockets should be cleaned 1598 * up, which means, we should be past the tcp_discardcb() calls. 1599 * Sleep to let all tcpcb timers really disappear and cleanup. 1600 */ 1601 for (;;) { 1602 INP_LIST_RLOCK(&V_tcbinfo); 1603 n = V_tcbinfo.ipi_count; 1604 INP_LIST_RUNLOCK(&V_tcbinfo); 1605 if (n == 0) 1606 break; 1607 pause("tcpdes", hz / 10); 1608 } 1609 tcp_hc_destroy(); 1610 syncache_destroy(); 1611 tcp_tw_destroy(); 1612 in_pcbinfo_destroy(&V_tcbinfo); 1613 /* tcp_discardcb() clears the sack_holes up. */ 1614 uma_zdestroy(V_sack_hole_zone); 1615 uma_zdestroy(V_tcpcb_zone); 1616 1617 /* 1618 * Cannot free the zone until all tcpcbs are released as we attach 1619 * the allocations to them. 1620 */ 1621 tcp_fastopen_destroy(); 1622 1623 #ifdef TCP_HHOOK 1624 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1625 if (error != 0) { 1626 printf("%s: WARNING: unable to deregister helper hook " 1627 "type=%d, id=%d: error %d returned\n", __func__, 1628 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1629 } 1630 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1631 if (error != 0) { 1632 printf("%s: WARNING: unable to deregister helper hook " 1633 "type=%d, id=%d: error %d returned\n", __func__, 1634 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1635 } 1636 #endif 1637 } 1638 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1639 #endif 1640 1641 void 1642 tcp_fini(void *xtp) 1643 { 1644 1645 } 1646 1647 /* 1648 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1649 * tcp_template used to store this data in mbufs, but we now recopy it out 1650 * of the tcpcb each time to conserve mbufs. 1651 */ 1652 void 1653 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1654 { 1655 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1656 1657 INP_WLOCK_ASSERT(inp); 1658 1659 #ifdef INET6 1660 if ((inp->inp_vflag & INP_IPV6) != 0) { 1661 struct ip6_hdr *ip6; 1662 1663 ip6 = (struct ip6_hdr *)ip_ptr; 1664 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1665 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1666 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1667 (IPV6_VERSION & IPV6_VERSION_MASK); 1668 if (port == 0) 1669 ip6->ip6_nxt = IPPROTO_TCP; 1670 else 1671 ip6->ip6_nxt = IPPROTO_UDP; 1672 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1673 ip6->ip6_src = inp->in6p_laddr; 1674 ip6->ip6_dst = inp->in6p_faddr; 1675 } 1676 #endif /* INET6 */ 1677 #if defined(INET6) && defined(INET) 1678 else 1679 #endif 1680 #ifdef INET 1681 { 1682 struct ip *ip; 1683 1684 ip = (struct ip *)ip_ptr; 1685 ip->ip_v = IPVERSION; 1686 ip->ip_hl = 5; 1687 ip->ip_tos = inp->inp_ip_tos; 1688 ip->ip_len = 0; 1689 ip->ip_id = 0; 1690 ip->ip_off = 0; 1691 ip->ip_ttl = inp->inp_ip_ttl; 1692 ip->ip_sum = 0; 1693 if (port == 0) 1694 ip->ip_p = IPPROTO_TCP; 1695 else 1696 ip->ip_p = IPPROTO_UDP; 1697 ip->ip_src = inp->inp_laddr; 1698 ip->ip_dst = inp->inp_faddr; 1699 } 1700 #endif /* INET */ 1701 th->th_sport = inp->inp_lport; 1702 th->th_dport = inp->inp_fport; 1703 th->th_seq = 0; 1704 th->th_ack = 0; 1705 th->th_x2 = 0; 1706 th->th_off = 5; 1707 th->th_flags = 0; 1708 th->th_win = 0; 1709 th->th_urp = 0; 1710 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1711 } 1712 1713 /* 1714 * Create template to be used to send tcp packets on a connection. 1715 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1716 * use for this function is in keepalives, which use tcp_respond. 1717 */ 1718 struct tcptemp * 1719 tcpip_maketemplate(struct inpcb *inp) 1720 { 1721 struct tcptemp *t; 1722 1723 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1724 if (t == NULL) 1725 return (NULL); 1726 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1727 return (t); 1728 } 1729 1730 /* 1731 * Send a single message to the TCP at address specified by 1732 * the given TCP/IP header. If m == NULL, then we make a copy 1733 * of the tcpiphdr at th and send directly to the addressed host. 1734 * This is used to force keep alive messages out using the TCP 1735 * template for a connection. If flags are given then we send 1736 * a message back to the TCP which originated the segment th, 1737 * and discard the mbuf containing it and any other attached mbufs. 1738 * 1739 * In any case the ack and sequence number of the transmitted 1740 * segment are as specified by the parameters. 1741 * 1742 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1743 */ 1744 void 1745 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1746 tcp_seq ack, tcp_seq seq, int flags) 1747 { 1748 struct tcpopt to; 1749 struct inpcb *inp; 1750 struct ip *ip; 1751 struct mbuf *optm; 1752 struct udphdr *uh = NULL; 1753 struct tcphdr *nth; 1754 struct tcp_log_buffer *lgb; 1755 u_char *optp; 1756 #ifdef INET6 1757 struct ip6_hdr *ip6; 1758 int isipv6; 1759 #endif /* INET6 */ 1760 int optlen, tlen, win, ulen; 1761 bool incl_opts; 1762 uint16_t port; 1763 int output_ret; 1764 #ifdef INVARIANTS 1765 int thflags = th->th_flags; 1766 #endif 1767 1768 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1769 NET_EPOCH_ASSERT(); 1770 1771 #ifdef INET6 1772 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1773 ip6 = ipgen; 1774 #endif /* INET6 */ 1775 ip = ipgen; 1776 1777 if (tp != NULL) { 1778 inp = tp->t_inpcb; 1779 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1780 INP_LOCK_ASSERT(inp); 1781 } else 1782 inp = NULL; 1783 1784 if (m != NULL) { 1785 #ifdef INET6 1786 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1787 port = m->m_pkthdr.tcp_tun_port; 1788 else 1789 #endif 1790 if (ip && (ip->ip_p == IPPROTO_UDP)) 1791 port = m->m_pkthdr.tcp_tun_port; 1792 else 1793 port = 0; 1794 } else 1795 port = tp->t_port; 1796 1797 incl_opts = false; 1798 win = 0; 1799 if (tp != NULL) { 1800 if (!(flags & TH_RST)) { 1801 win = sbspace(&inp->inp_socket->so_rcv); 1802 if (win > TCP_MAXWIN << tp->rcv_scale) 1803 win = TCP_MAXWIN << tp->rcv_scale; 1804 } 1805 if ((tp->t_flags & TF_NOOPT) == 0) 1806 incl_opts = true; 1807 } 1808 if (m == NULL) { 1809 m = m_gethdr(M_NOWAIT, MT_DATA); 1810 if (m == NULL) 1811 return; 1812 m->m_data += max_linkhdr; 1813 #ifdef INET6 1814 if (isipv6) { 1815 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1816 sizeof(struct ip6_hdr)); 1817 ip6 = mtod(m, struct ip6_hdr *); 1818 nth = (struct tcphdr *)(ip6 + 1); 1819 if (port) { 1820 /* Insert a UDP header */ 1821 uh = (struct udphdr *)nth; 1822 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1823 uh->uh_dport = port; 1824 nth = (struct tcphdr *)(uh + 1); 1825 } 1826 } else 1827 #endif /* INET6 */ 1828 { 1829 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1830 ip = mtod(m, struct ip *); 1831 nth = (struct tcphdr *)(ip + 1); 1832 if (port) { 1833 /* Insert a UDP header */ 1834 uh = (struct udphdr *)nth; 1835 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1836 uh->uh_dport = port; 1837 nth = (struct tcphdr *)(uh + 1); 1838 } 1839 } 1840 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1841 flags = TH_ACK; 1842 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1843 struct mbuf *n; 1844 1845 /* Can't reuse 'm', allocate a new mbuf. */ 1846 n = m_gethdr(M_NOWAIT, MT_DATA); 1847 if (n == NULL) { 1848 m_freem(m); 1849 return; 1850 } 1851 1852 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1853 m_freem(m); 1854 m_freem(n); 1855 return; 1856 } 1857 1858 n->m_data += max_linkhdr; 1859 /* m_len is set later */ 1860 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1861 #ifdef INET6 1862 if (isipv6) { 1863 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1864 sizeof(struct ip6_hdr)); 1865 ip6 = mtod(n, struct ip6_hdr *); 1866 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1867 nth = (struct tcphdr *)(ip6 + 1); 1868 if (port) { 1869 /* Insert a UDP header */ 1870 uh = (struct udphdr *)nth; 1871 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1872 uh->uh_dport = port; 1873 nth = (struct tcphdr *)(uh + 1); 1874 } 1875 } else 1876 #endif /* INET6 */ 1877 { 1878 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1879 ip = mtod(n, struct ip *); 1880 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1881 nth = (struct tcphdr *)(ip + 1); 1882 if (port) { 1883 /* Insert a UDP header */ 1884 uh = (struct udphdr *)nth; 1885 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1886 uh->uh_dport = port; 1887 nth = (struct tcphdr *)(uh + 1); 1888 } 1889 } 1890 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1891 xchg(nth->th_dport, nth->th_sport, uint16_t); 1892 th = nth; 1893 m_freem(m); 1894 m = n; 1895 } else { 1896 /* 1897 * reuse the mbuf. 1898 * XXX MRT We inherit the FIB, which is lucky. 1899 */ 1900 m_freem(m->m_next); 1901 m->m_next = NULL; 1902 m->m_data = (caddr_t)ipgen; 1903 /* m_len is set later */ 1904 #ifdef INET6 1905 if (isipv6) { 1906 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1907 nth = (struct tcphdr *)(ip6 + 1); 1908 } else 1909 #endif /* INET6 */ 1910 { 1911 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1912 nth = (struct tcphdr *)(ip + 1); 1913 } 1914 if (th != nth) { 1915 /* 1916 * this is usually a case when an extension header 1917 * exists between the IPv6 header and the 1918 * TCP header. 1919 */ 1920 nth->th_sport = th->th_sport; 1921 nth->th_dport = th->th_dport; 1922 } 1923 xchg(nth->th_dport, nth->th_sport, uint16_t); 1924 #undef xchg 1925 } 1926 tlen = 0; 1927 #ifdef INET6 1928 if (isipv6) 1929 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1930 #endif 1931 #if defined(INET) && defined(INET6) 1932 else 1933 #endif 1934 #ifdef INET 1935 tlen = sizeof (struct tcpiphdr); 1936 #endif 1937 if (port) 1938 tlen += sizeof (struct udphdr); 1939 #ifdef INVARIANTS 1940 m->m_len = 0; 1941 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1942 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1943 m, tlen, (long)M_TRAILINGSPACE(m))); 1944 #endif 1945 m->m_len = tlen; 1946 to.to_flags = 0; 1947 if (incl_opts) { 1948 /* Make sure we have room. */ 1949 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1950 m->m_next = m_get(M_NOWAIT, MT_DATA); 1951 if (m->m_next) { 1952 optp = mtod(m->m_next, u_char *); 1953 optm = m->m_next; 1954 } else 1955 incl_opts = false; 1956 } else { 1957 optp = (u_char *) (nth + 1); 1958 optm = m; 1959 } 1960 } 1961 if (incl_opts) { 1962 /* Timestamps. */ 1963 if (tp->t_flags & TF_RCVD_TSTMP) { 1964 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1965 to.to_tsecr = tp->ts_recent; 1966 to.to_flags |= TOF_TS; 1967 } 1968 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1969 /* TCP-MD5 (RFC2385). */ 1970 if (tp->t_flags & TF_SIGNATURE) 1971 to.to_flags |= TOF_SIGNATURE; 1972 #endif 1973 /* Add the options. */ 1974 tlen += optlen = tcp_addoptions(&to, optp); 1975 1976 /* Update m_len in the correct mbuf. */ 1977 optm->m_len += optlen; 1978 } else 1979 optlen = 0; 1980 #ifdef INET6 1981 if (isipv6) { 1982 if (uh) { 1983 ulen = tlen - sizeof(struct ip6_hdr); 1984 uh->uh_ulen = htons(ulen); 1985 } 1986 ip6->ip6_flow = 0; 1987 ip6->ip6_vfc = IPV6_VERSION; 1988 if (port) 1989 ip6->ip6_nxt = IPPROTO_UDP; 1990 else 1991 ip6->ip6_nxt = IPPROTO_TCP; 1992 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1993 } 1994 #endif 1995 #if defined(INET) && defined(INET6) 1996 else 1997 #endif 1998 #ifdef INET 1999 { 2000 if (uh) { 2001 ulen = tlen - sizeof(struct ip); 2002 uh->uh_ulen = htons(ulen); 2003 } 2004 ip->ip_len = htons(tlen); 2005 ip->ip_ttl = V_ip_defttl; 2006 if (port) { 2007 ip->ip_p = IPPROTO_UDP; 2008 } else { 2009 ip->ip_p = IPPROTO_TCP; 2010 } 2011 if (V_path_mtu_discovery) 2012 ip->ip_off |= htons(IP_DF); 2013 } 2014 #endif 2015 m->m_pkthdr.len = tlen; 2016 m->m_pkthdr.rcvif = NULL; 2017 #ifdef MAC 2018 if (inp != NULL) { 2019 /* 2020 * Packet is associated with a socket, so allow the 2021 * label of the response to reflect the socket label. 2022 */ 2023 INP_LOCK_ASSERT(inp); 2024 mac_inpcb_create_mbuf(inp, m); 2025 } else { 2026 /* 2027 * Packet is not associated with a socket, so possibly 2028 * update the label in place. 2029 */ 2030 mac_netinet_tcp_reply(m); 2031 } 2032 #endif 2033 nth->th_seq = htonl(seq); 2034 nth->th_ack = htonl(ack); 2035 nth->th_x2 = 0; 2036 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2037 nth->th_flags = flags; 2038 if (tp != NULL) 2039 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2040 else 2041 nth->th_win = htons((u_short)win); 2042 nth->th_urp = 0; 2043 2044 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2045 if (to.to_flags & TOF_SIGNATURE) { 2046 if (!TCPMD5_ENABLED() || 2047 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2048 m_freem(m); 2049 return; 2050 } 2051 } 2052 #endif 2053 2054 #ifdef INET6 2055 if (isipv6) { 2056 if (port) { 2057 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2058 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2059 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2060 nth->th_sum = 0; 2061 } else { 2062 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2063 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2064 nth->th_sum = in6_cksum_pseudo(ip6, 2065 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2066 } 2067 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2068 NULL, NULL); 2069 } 2070 #endif /* INET6 */ 2071 #if defined(INET6) && defined(INET) 2072 else 2073 #endif 2074 #ifdef INET 2075 { 2076 if (port) { 2077 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2078 htons(ulen + IPPROTO_UDP)); 2079 m->m_pkthdr.csum_flags = CSUM_UDP; 2080 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2081 nth->th_sum = 0; 2082 } else { 2083 m->m_pkthdr.csum_flags = CSUM_TCP; 2084 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2085 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2086 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2087 } 2088 } 2089 #endif /* INET */ 2090 #ifdef TCPDEBUG 2091 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2092 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2093 #endif 2094 TCP_PROBE3(debug__output, tp, th, m); 2095 if (flags & TH_RST) 2096 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2097 lgb = NULL; 2098 if ((tp != NULL) && (tp->t_logstate != TCP_LOG_STATE_OFF)) { 2099 if (INP_WLOCKED(inp)) { 2100 union tcp_log_stackspecific log; 2101 struct timeval tv; 2102 2103 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2104 log.u_bbr.inhpts = tp->t_inpcb->inp_in_hpts; 2105 log.u_bbr.ininput = tp->t_inpcb->inp_in_input; 2106 log.u_bbr.flex8 = 4; 2107 log.u_bbr.pkts_out = tp->t_maxseg; 2108 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2109 log.u_bbr.delivered = 0; 2110 lgb = tcp_log_event_(tp, nth, NULL, NULL, TCP_LOG_OUT, 2111 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2112 } else { 2113 /* 2114 * We can not log the packet, since we only own the 2115 * read lock, but a write lock is needed. The read lock 2116 * is not upgraded to a write lock, since only getting 2117 * the read lock was done intentionally to improve the 2118 * handling of SYN flooding attacks. 2119 * This happens only for pure SYN segments received in 2120 * the initial CLOSED state, or received in a more 2121 * advanced state than listen and the UDP encapsulation 2122 * port is unexpected. 2123 * The incoming SYN segments do not really belong to 2124 * the TCP connection and the handling does not change 2125 * the state of the TCP connection. Therefore, the 2126 * sending of the RST segments is not logged. Please 2127 * note that also the incoming SYN segments are not 2128 * logged. 2129 * 2130 * The following code ensures that the above description 2131 * is and stays correct. 2132 */ 2133 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2134 (tp->t_state == TCPS_CLOSED || 2135 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2136 ("%s: Logging of TCP segment with flags 0x%b and " 2137 "UDP encapsulation port %u skipped in state %s", 2138 __func__, thflags, PRINT_TH_FLAGS, 2139 ntohs(port), tcpstates[tp->t_state])); 2140 } 2141 } 2142 2143 #ifdef INET6 2144 if (isipv6) { 2145 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2146 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2147 } 2148 #endif /* INET6 */ 2149 #if defined(INET) && defined(INET6) 2150 else 2151 #endif 2152 #ifdef INET 2153 { 2154 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2155 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2156 } 2157 #endif 2158 if (lgb != NULL) 2159 lgb->tlb_errno = output_ret; 2160 } 2161 2162 /* 2163 * Create a new TCP control block, making an 2164 * empty reassembly queue and hooking it to the argument 2165 * protocol control block. The `inp' parameter must have 2166 * come from the zone allocator set up in tcp_init(). 2167 */ 2168 struct tcpcb * 2169 tcp_newtcpcb(struct inpcb *inp) 2170 { 2171 struct tcpcb_mem *tm; 2172 struct tcpcb *tp; 2173 #ifdef INET6 2174 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2175 #endif /* INET6 */ 2176 2177 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2178 if (tm == NULL) 2179 return (NULL); 2180 tp = &tm->tcb; 2181 2182 /* Initialise cc_var struct for this tcpcb. */ 2183 tp->ccv = &tm->ccv; 2184 tp->ccv->type = IPPROTO_TCP; 2185 tp->ccv->ccvc.tcp = tp; 2186 rw_rlock(&tcp_function_lock); 2187 tp->t_fb = tcp_func_set_ptr; 2188 refcount_acquire(&tp->t_fb->tfb_refcnt); 2189 rw_runlock(&tcp_function_lock); 2190 /* 2191 * Use the current system default CC algorithm. 2192 */ 2193 CC_LIST_RLOCK(); 2194 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 2195 CC_ALGO(tp) = CC_DEFAULT_ALGO(); 2196 CC_LIST_RUNLOCK(); 2197 2198 /* 2199 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2200 * is called. 2201 */ 2202 in_pcbref(inp); /* Reference for tcpcb */ 2203 tp->t_inpcb = inp; 2204 2205 if (CC_ALGO(tp)->cb_init != NULL) 2206 if (CC_ALGO(tp)->cb_init(tp->ccv, NULL) > 0) { 2207 if (tp->t_fb->tfb_tcp_fb_fini) 2208 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2209 in_pcbrele_wlocked(inp); 2210 refcount_release(&tp->t_fb->tfb_refcnt); 2211 uma_zfree(V_tcpcb_zone, tm); 2212 return (NULL); 2213 } 2214 2215 #ifdef TCP_HHOOK 2216 tp->osd = &tm->osd; 2217 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2218 if (tp->t_fb->tfb_tcp_fb_fini) 2219 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2220 in_pcbrele_wlocked(inp); 2221 refcount_release(&tp->t_fb->tfb_refcnt); 2222 uma_zfree(V_tcpcb_zone, tm); 2223 return (NULL); 2224 } 2225 #endif 2226 2227 #ifdef VIMAGE 2228 tp->t_vnet = inp->inp_vnet; 2229 #endif 2230 tp->t_timers = &tm->tt; 2231 TAILQ_INIT(&tp->t_segq); 2232 tp->t_maxseg = 2233 #ifdef INET6 2234 isipv6 ? V_tcp_v6mssdflt : 2235 #endif /* INET6 */ 2236 V_tcp_mssdflt; 2237 2238 /* Set up our timeouts. */ 2239 callout_init(&tp->t_timers->tt_rexmt, 1); 2240 callout_init(&tp->t_timers->tt_persist, 1); 2241 callout_init(&tp->t_timers->tt_keep, 1); 2242 callout_init(&tp->t_timers->tt_2msl, 1); 2243 callout_init(&tp->t_timers->tt_delack, 1); 2244 2245 if (V_tcp_do_rfc1323) 2246 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2247 if (V_tcp_do_sack) 2248 tp->t_flags |= TF_SACK_PERMIT; 2249 TAILQ_INIT(&tp->snd_holes); 2250 2251 /* 2252 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2253 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2254 * reasonable initial retransmit time. 2255 */ 2256 tp->t_srtt = TCPTV_SRTTBASE; 2257 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2258 tp->t_rttmin = tcp_rexmit_min; 2259 tp->t_rxtcur = tcp_rexmit_initial; 2260 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2261 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2262 tp->t_rcvtime = ticks; 2263 /* 2264 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2265 * because the socket may be bound to an IPv6 wildcard address, 2266 * which may match an IPv4-mapped IPv6 address. 2267 */ 2268 inp->inp_ip_ttl = V_ip_defttl; 2269 inp->inp_ppcb = tp; 2270 #ifdef TCPPCAP 2271 /* 2272 * Init the TCP PCAP queues. 2273 */ 2274 tcp_pcap_tcpcb_init(tp); 2275 #endif 2276 #ifdef TCP_BLACKBOX 2277 /* Initialize the per-TCPCB log data. */ 2278 tcp_log_tcpcbinit(tp); 2279 #endif 2280 tp->t_pacing_rate = -1; 2281 if (tp->t_fb->tfb_tcp_fb_init) { 2282 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2283 refcount_release(&tp->t_fb->tfb_refcnt); 2284 in_pcbrele_wlocked(inp); 2285 uma_zfree(V_tcpcb_zone, tm); 2286 return (NULL); 2287 } 2288 } 2289 #ifdef STATS 2290 if (V_tcp_perconn_stats_enable == 1) 2291 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2292 #endif 2293 if (V_tcp_do_lrd) 2294 tp->t_flags |= TF_LRD; 2295 return (tp); /* XXX */ 2296 } 2297 2298 /* 2299 * Switch the congestion control algorithm back to Vnet default for any active 2300 * control blocks using an algorithm which is about to go away. If the algorithm 2301 * has a cb_init function and it fails (no memory) then the operation fails and 2302 * the unload will not succeed. 2303 * 2304 */ 2305 int 2306 tcp_ccalgounload(struct cc_algo *unload_algo) 2307 { 2308 struct cc_algo *oldalgo, *newalgo; 2309 struct inpcb *inp; 2310 struct tcpcb *tp; 2311 VNET_ITERATOR_DECL(vnet_iter); 2312 2313 /* 2314 * Check all active control blocks across all network stacks and change 2315 * any that are using "unload_algo" back to its default. If "unload_algo" 2316 * requires cleanup code to be run, call it. 2317 */ 2318 VNET_LIST_RLOCK(); 2319 VNET_FOREACH(vnet_iter) { 2320 CURVNET_SET(vnet_iter); 2321 INP_INFO_WLOCK(&V_tcbinfo); 2322 /* 2323 * New connections already part way through being initialised 2324 * with the CC algo we're removing will not race with this code 2325 * because the INP_INFO_WLOCK is held during initialisation. We 2326 * therefore don't enter the loop below until the connection 2327 * list has stabilised. 2328 */ 2329 newalgo = CC_DEFAULT_ALGO(); 2330 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 2331 INP_WLOCK(inp); 2332 /* Important to skip tcptw structs. */ 2333 if (!(inp->inp_flags & INP_TIMEWAIT) && 2334 (tp = intotcpcb(inp)) != NULL) { 2335 /* 2336 * By holding INP_WLOCK here, we are assured 2337 * that the connection is not currently 2338 * executing inside the CC module's functions. 2339 * We attempt to switch to the Vnets default, 2340 * if the init fails then we fail the whole 2341 * operation and the module unload will fail. 2342 */ 2343 if (CC_ALGO(tp) == unload_algo) { 2344 struct cc_var cc_mem; 2345 int err; 2346 2347 oldalgo = CC_ALGO(tp); 2348 memset(&cc_mem, 0, sizeof(cc_mem)); 2349 cc_mem.ccvc.tcp = tp; 2350 if (newalgo->cb_init == NULL) { 2351 /* 2352 * No init we can skip the 2353 * dance around a possible failure. 2354 */ 2355 CC_DATA(tp) = NULL; 2356 goto proceed; 2357 } 2358 err = (newalgo->cb_init)(&cc_mem, NULL); 2359 if (err) { 2360 /* 2361 * Presumably no memory the caller will 2362 * need to try again. 2363 */ 2364 INP_WUNLOCK(inp); 2365 INP_INFO_WUNLOCK(&V_tcbinfo); 2366 CURVNET_RESTORE(); 2367 VNET_LIST_RUNLOCK(); 2368 return (err); 2369 } 2370 proceed: 2371 if (oldalgo->cb_destroy != NULL) 2372 oldalgo->cb_destroy(tp->ccv); 2373 CC_ALGO(tp) = newalgo; 2374 memcpy(tp->ccv, &cc_mem, sizeof(struct cc_var)); 2375 if (TCPS_HAVEESTABLISHED(tp->t_state) && 2376 (CC_ALGO(tp)->conn_init != NULL)) { 2377 /* Yep run the connection init for the new CC */ 2378 CC_ALGO(tp)->conn_init(tp->ccv); 2379 } 2380 } 2381 } 2382 INP_WUNLOCK(inp); 2383 } 2384 INP_INFO_WUNLOCK(&V_tcbinfo); 2385 CURVNET_RESTORE(); 2386 } 2387 VNET_LIST_RUNLOCK(); 2388 return (0); 2389 } 2390 2391 /* 2392 * Drop a TCP connection, reporting 2393 * the specified error. If connection is synchronized, 2394 * then send a RST to peer. 2395 */ 2396 struct tcpcb * 2397 tcp_drop(struct tcpcb *tp, int errno) 2398 { 2399 struct socket *so = tp->t_inpcb->inp_socket; 2400 2401 NET_EPOCH_ASSERT(); 2402 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2403 INP_WLOCK_ASSERT(tp->t_inpcb); 2404 2405 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2406 tcp_state_change(tp, TCPS_CLOSED); 2407 (void) tp->t_fb->tfb_tcp_output(tp); 2408 TCPSTAT_INC(tcps_drops); 2409 } else 2410 TCPSTAT_INC(tcps_conndrops); 2411 if (errno == ETIMEDOUT && tp->t_softerror) 2412 errno = tp->t_softerror; 2413 so->so_error = errno; 2414 return (tcp_close(tp)); 2415 } 2416 2417 void 2418 tcp_discardcb(struct tcpcb *tp) 2419 { 2420 struct inpcb *inp = tp->t_inpcb; 2421 2422 INP_WLOCK_ASSERT(inp); 2423 2424 /* 2425 * Make sure that all of our timers are stopped before we delete the 2426 * PCB. 2427 * 2428 * If stopping a timer fails, we schedule a discard function in same 2429 * callout, and the last discard function called will take care of 2430 * deleting the tcpcb. 2431 */ 2432 tp->t_timers->tt_draincnt = 0; 2433 tcp_timer_stop(tp, TT_REXMT); 2434 tcp_timer_stop(tp, TT_PERSIST); 2435 tcp_timer_stop(tp, TT_KEEP); 2436 tcp_timer_stop(tp, TT_2MSL); 2437 tcp_timer_stop(tp, TT_DELACK); 2438 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2439 /* 2440 * Call the stop-all function of the methods, 2441 * this function should call the tcp_timer_stop() 2442 * method with each of the function specific timeouts. 2443 * That stop will be called via the tfb_tcp_timer_stop() 2444 * which should use the async drain function of the 2445 * callout system (see tcp_var.h). 2446 */ 2447 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2448 } 2449 2450 /* free the reassembly queue, if any */ 2451 tcp_reass_flush(tp); 2452 2453 #ifdef TCP_OFFLOAD 2454 /* Disconnect offload device, if any. */ 2455 if (tp->t_flags & TF_TOE) 2456 tcp_offload_detach(tp); 2457 #endif 2458 2459 tcp_free_sackholes(tp); 2460 2461 #ifdef TCPPCAP 2462 /* Free the TCP PCAP queues. */ 2463 tcp_pcap_drain(&(tp->t_inpkts)); 2464 tcp_pcap_drain(&(tp->t_outpkts)); 2465 #endif 2466 2467 /* Allow the CC algorithm to clean up after itself. */ 2468 if (CC_ALGO(tp)->cb_destroy != NULL) 2469 CC_ALGO(tp)->cb_destroy(tp->ccv); 2470 CC_DATA(tp) = NULL; 2471 2472 #ifdef TCP_HHOOK 2473 khelp_destroy_osd(tp->osd); 2474 #endif 2475 #ifdef STATS 2476 stats_blob_destroy(tp->t_stats); 2477 #endif 2478 2479 CC_ALGO(tp) = NULL; 2480 inp->inp_ppcb = NULL; 2481 if (tp->t_timers->tt_draincnt == 0) { 2482 bool released __diagused; 2483 2484 released = tcp_freecb(tp); 2485 KASSERT(!released, ("%s: inp %p should not have been released " 2486 "here", __func__, inp)); 2487 } 2488 } 2489 2490 bool 2491 tcp_freecb(struct tcpcb *tp) 2492 { 2493 struct inpcb *inp = tp->t_inpcb; 2494 struct socket *so = inp->inp_socket; 2495 #ifdef INET6 2496 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2497 #endif 2498 2499 INP_WLOCK_ASSERT(inp); 2500 MPASS(tp->t_timers->tt_draincnt == 0); 2501 2502 /* We own the last reference on tcpcb, let's free it. */ 2503 #ifdef TCP_BLACKBOX 2504 tcp_log_tcpcbfini(tp); 2505 #endif 2506 TCPSTATES_DEC(tp->t_state); 2507 if (tp->t_fb->tfb_tcp_fb_fini) 2508 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2509 2510 /* 2511 * If we got enough samples through the srtt filter, 2512 * save the rtt and rttvar in the routing entry. 2513 * 'Enough' is arbitrarily defined as 4 rtt samples. 2514 * 4 samples is enough for the srtt filter to converge 2515 * to within enough % of the correct value; fewer samples 2516 * and we could save a bogus rtt. The danger is not high 2517 * as tcp quickly recovers from everything. 2518 * XXX: Works very well but needs some more statistics! 2519 * 2520 * XXXRRS: Updating must be after the stack fini() since 2521 * that may be converting some internal representation of 2522 * say srtt etc into the general one used by other stacks. 2523 * Lets also at least protect against the so being NULL 2524 * as RW stated below. 2525 */ 2526 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2527 struct hc_metrics_lite metrics; 2528 uint32_t ssthresh; 2529 2530 bzero(&metrics, sizeof(metrics)); 2531 /* 2532 * Update the ssthresh always when the conditions below 2533 * are satisfied. This gives us better new start value 2534 * for the congestion avoidance for new connections. 2535 * ssthresh is only set if packet loss occurred on a session. 2536 * 2537 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2538 * being torn down. Ideally this code would not use 'so'. 2539 */ 2540 ssthresh = tp->snd_ssthresh; 2541 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2542 /* 2543 * convert the limit from user data bytes to 2544 * packets then to packet data bytes. 2545 */ 2546 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2547 if (ssthresh < 2) 2548 ssthresh = 2; 2549 ssthresh *= (tp->t_maxseg + 2550 #ifdef INET6 2551 (isipv6 ? sizeof (struct ip6_hdr) + 2552 sizeof (struct tcphdr) : 2553 #endif 2554 sizeof (struct tcpiphdr) 2555 #ifdef INET6 2556 ) 2557 #endif 2558 ); 2559 } else 2560 ssthresh = 0; 2561 metrics.rmx_ssthresh = ssthresh; 2562 2563 metrics.rmx_rtt = tp->t_srtt; 2564 metrics.rmx_rttvar = tp->t_rttvar; 2565 metrics.rmx_cwnd = tp->snd_cwnd; 2566 metrics.rmx_sendpipe = 0; 2567 metrics.rmx_recvpipe = 0; 2568 2569 tcp_hc_update(&inp->inp_inc, &metrics); 2570 } 2571 2572 refcount_release(&tp->t_fb->tfb_refcnt); 2573 uma_zfree(V_tcpcb_zone, tp); 2574 2575 return (in_pcbrele_wlocked(inp)); 2576 } 2577 2578 /* 2579 * Attempt to close a TCP control block, marking it as dropped, and freeing 2580 * the socket if we hold the only reference. 2581 */ 2582 struct tcpcb * 2583 tcp_close(struct tcpcb *tp) 2584 { 2585 struct inpcb *inp = tp->t_inpcb; 2586 struct socket *so; 2587 2588 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2589 INP_WLOCK_ASSERT(inp); 2590 2591 #ifdef TCP_OFFLOAD 2592 if (tp->t_state == TCPS_LISTEN) 2593 tcp_offload_listen_stop(tp); 2594 #endif 2595 /* 2596 * This releases the TFO pending counter resource for TFO listen 2597 * sockets as well as passively-created TFO sockets that transition 2598 * from SYN_RECEIVED to CLOSED. 2599 */ 2600 if (tp->t_tfo_pending) { 2601 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2602 tp->t_tfo_pending = NULL; 2603 } 2604 in_pcbdrop(inp); 2605 TCPSTAT_INC(tcps_closed); 2606 if (tp->t_state != TCPS_CLOSED) 2607 tcp_state_change(tp, TCPS_CLOSED); 2608 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2609 so = inp->inp_socket; 2610 soisdisconnected(so); 2611 if (inp->inp_flags & INP_SOCKREF) { 2612 KASSERT(so->so_state & SS_PROTOREF, 2613 ("tcp_close: !SS_PROTOREF")); 2614 inp->inp_flags &= ~INP_SOCKREF; 2615 INP_WUNLOCK(inp); 2616 SOCK_LOCK(so); 2617 so->so_state &= ~SS_PROTOREF; 2618 sofree(so); 2619 return (NULL); 2620 } 2621 return (tp); 2622 } 2623 2624 void 2625 tcp_drain(void) 2626 { 2627 VNET_ITERATOR_DECL(vnet_iter); 2628 2629 if (!do_tcpdrain) 2630 return; 2631 2632 VNET_LIST_RLOCK_NOSLEEP(); 2633 VNET_FOREACH(vnet_iter) { 2634 CURVNET_SET(vnet_iter); 2635 struct inpcb *inpb; 2636 struct tcpcb *tcpb; 2637 2638 /* 2639 * Walk the tcpbs, if existing, and flush the reassembly queue, 2640 * if there is one... 2641 * XXX: The "Net/3" implementation doesn't imply that the TCP 2642 * reassembly queue should be flushed, but in a situation 2643 * where we're really low on mbufs, this is potentially 2644 * useful. 2645 */ 2646 INP_INFO_WLOCK(&V_tcbinfo); 2647 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2648 INP_WLOCK(inpb); 2649 if (inpb->inp_flags & INP_TIMEWAIT) { 2650 INP_WUNLOCK(inpb); 2651 continue; 2652 } 2653 if ((tcpb = intotcpcb(inpb)) != NULL) { 2654 tcp_reass_flush(tcpb); 2655 tcp_clean_sackreport(tcpb); 2656 #ifdef TCP_BLACKBOX 2657 tcp_log_drain(tcpb); 2658 #endif 2659 #ifdef TCPPCAP 2660 if (tcp_pcap_aggressive_free) { 2661 /* Free the TCP PCAP queues. */ 2662 tcp_pcap_drain(&(tcpb->t_inpkts)); 2663 tcp_pcap_drain(&(tcpb->t_outpkts)); 2664 } 2665 #endif 2666 } 2667 INP_WUNLOCK(inpb); 2668 } 2669 INP_INFO_WUNLOCK(&V_tcbinfo); 2670 CURVNET_RESTORE(); 2671 } 2672 VNET_LIST_RUNLOCK_NOSLEEP(); 2673 } 2674 2675 /* 2676 * Notify a tcp user of an asynchronous error; 2677 * store error as soft error, but wake up user 2678 * (for now, won't do anything until can select for soft error). 2679 * 2680 * Do not wake up user since there currently is no mechanism for 2681 * reporting soft errors (yet - a kqueue filter may be added). 2682 */ 2683 static struct inpcb * 2684 tcp_notify(struct inpcb *inp, int error) 2685 { 2686 struct tcpcb *tp; 2687 2688 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2689 INP_WLOCK_ASSERT(inp); 2690 2691 if ((inp->inp_flags & INP_TIMEWAIT) || 2692 (inp->inp_flags & INP_DROPPED)) 2693 return (inp); 2694 2695 tp = intotcpcb(inp); 2696 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2697 2698 /* 2699 * Ignore some errors if we are hooked up. 2700 * If connection hasn't completed, has retransmitted several times, 2701 * and receives a second error, give up now. This is better 2702 * than waiting a long time to establish a connection that 2703 * can never complete. 2704 */ 2705 if (tp->t_state == TCPS_ESTABLISHED && 2706 (error == EHOSTUNREACH || error == ENETUNREACH || 2707 error == EHOSTDOWN)) { 2708 if (inp->inp_route.ro_nh) { 2709 NH_FREE(inp->inp_route.ro_nh); 2710 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2711 } 2712 return (inp); 2713 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2714 tp->t_softerror) { 2715 tp = tcp_drop(tp, error); 2716 if (tp != NULL) 2717 return (inp); 2718 else 2719 return (NULL); 2720 } else { 2721 tp->t_softerror = error; 2722 return (inp); 2723 } 2724 #if 0 2725 wakeup( &so->so_timeo); 2726 sorwakeup(so); 2727 sowwakeup(so); 2728 #endif 2729 } 2730 2731 static int 2732 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2733 { 2734 struct epoch_tracker et; 2735 struct inpcb *inp; 2736 struct xinpgen xig; 2737 int error; 2738 2739 if (req->newptr != NULL) 2740 return (EPERM); 2741 2742 if (req->oldptr == NULL) { 2743 int n; 2744 2745 n = V_tcbinfo.ipi_count + 2746 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2747 n += imax(n / 8, 10); 2748 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2749 return (0); 2750 } 2751 2752 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2753 return (error); 2754 2755 bzero(&xig, sizeof(xig)); 2756 xig.xig_len = sizeof xig; 2757 xig.xig_count = V_tcbinfo.ipi_count + 2758 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2759 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2760 xig.xig_sogen = so_gencnt; 2761 error = SYSCTL_OUT(req, &xig, sizeof xig); 2762 if (error) 2763 return (error); 2764 2765 error = syncache_pcblist(req); 2766 if (error) 2767 return (error); 2768 2769 NET_EPOCH_ENTER(et); 2770 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2771 inp != NULL; 2772 inp = CK_LIST_NEXT(inp, inp_list)) { 2773 INP_RLOCK(inp); 2774 if (inp->inp_gencnt <= xig.xig_gen) { 2775 int crerr; 2776 2777 /* 2778 * XXX: This use of cr_cansee(), introduced with 2779 * TCP state changes, is not quite right, but for 2780 * now, better than nothing. 2781 */ 2782 if (inp->inp_flags & INP_TIMEWAIT) { 2783 if (intotw(inp) != NULL) 2784 crerr = cr_cansee(req->td->td_ucred, 2785 intotw(inp)->tw_cred); 2786 else 2787 crerr = EINVAL; /* Skip this inp. */ 2788 } else 2789 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2790 if (crerr == 0) { 2791 struct xtcpcb xt; 2792 2793 tcp_inptoxtp(inp, &xt); 2794 INP_RUNLOCK(inp); 2795 error = SYSCTL_OUT(req, &xt, sizeof xt); 2796 if (error) 2797 break; 2798 else 2799 continue; 2800 } 2801 } 2802 INP_RUNLOCK(inp); 2803 } 2804 NET_EPOCH_EXIT(et); 2805 2806 if (!error) { 2807 /* 2808 * Give the user an updated idea of our state. 2809 * If the generation differs from what we told 2810 * her before, she knows that something happened 2811 * while we were processing this request, and it 2812 * might be necessary to retry. 2813 */ 2814 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2815 xig.xig_sogen = so_gencnt; 2816 xig.xig_count = V_tcbinfo.ipi_count + 2817 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2818 error = SYSCTL_OUT(req, &xig, sizeof xig); 2819 } 2820 2821 return (error); 2822 } 2823 2824 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2825 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2826 NULL, 0, tcp_pcblist, "S,xtcpcb", 2827 "List of active TCP connections"); 2828 2829 #ifdef INET 2830 static int 2831 tcp_getcred(SYSCTL_HANDLER_ARGS) 2832 { 2833 struct xucred xuc; 2834 struct sockaddr_in addrs[2]; 2835 struct epoch_tracker et; 2836 struct inpcb *inp; 2837 int error; 2838 2839 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2840 if (error) 2841 return (error); 2842 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2843 if (error) 2844 return (error); 2845 NET_EPOCH_ENTER(et); 2846 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2847 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2848 NET_EPOCH_EXIT(et); 2849 if (inp != NULL) { 2850 if (inp->inp_socket == NULL) 2851 error = ENOENT; 2852 if (error == 0) 2853 error = cr_canseeinpcb(req->td->td_ucred, inp); 2854 if (error == 0) 2855 cru2x(inp->inp_cred, &xuc); 2856 INP_RUNLOCK(inp); 2857 } else 2858 error = ENOENT; 2859 if (error == 0) 2860 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2861 return (error); 2862 } 2863 2864 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2865 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2866 0, 0, tcp_getcred, "S,xucred", 2867 "Get the xucred of a TCP connection"); 2868 #endif /* INET */ 2869 2870 #ifdef INET6 2871 static int 2872 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2873 { 2874 struct epoch_tracker et; 2875 struct xucred xuc; 2876 struct sockaddr_in6 addrs[2]; 2877 struct inpcb *inp; 2878 int error; 2879 #ifdef INET 2880 int mapped = 0; 2881 #endif 2882 2883 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2884 if (error) 2885 return (error); 2886 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2887 if (error) 2888 return (error); 2889 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2890 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2891 return (error); 2892 } 2893 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2894 #ifdef INET 2895 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2896 mapped = 1; 2897 else 2898 #endif 2899 return (EINVAL); 2900 } 2901 2902 NET_EPOCH_ENTER(et); 2903 #ifdef INET 2904 if (mapped == 1) 2905 inp = in_pcblookup(&V_tcbinfo, 2906 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2907 addrs[1].sin6_port, 2908 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2909 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2910 else 2911 #endif 2912 inp = in6_pcblookup(&V_tcbinfo, 2913 &addrs[1].sin6_addr, addrs[1].sin6_port, 2914 &addrs[0].sin6_addr, addrs[0].sin6_port, 2915 INPLOOKUP_RLOCKPCB, NULL); 2916 NET_EPOCH_EXIT(et); 2917 if (inp != NULL) { 2918 if (inp->inp_socket == NULL) 2919 error = ENOENT; 2920 if (error == 0) 2921 error = cr_canseeinpcb(req->td->td_ucred, inp); 2922 if (error == 0) 2923 cru2x(inp->inp_cred, &xuc); 2924 INP_RUNLOCK(inp); 2925 } else 2926 error = ENOENT; 2927 if (error == 0) 2928 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2929 return (error); 2930 } 2931 2932 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2933 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2934 0, 0, tcp6_getcred, "S,xucred", 2935 "Get the xucred of a TCP6 connection"); 2936 #endif /* INET6 */ 2937 2938 #ifdef INET 2939 /* Path MTU to try next when a fragmentation-needed message is received. */ 2940 static inline int 2941 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2942 { 2943 int mtu = ntohs(icp->icmp_nextmtu); 2944 2945 /* If no alternative MTU was proposed, try the next smaller one. */ 2946 if (!mtu) 2947 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2948 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2949 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2950 2951 return (mtu); 2952 } 2953 2954 static void 2955 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2956 { 2957 struct ip *ip = vip; 2958 struct tcphdr *th; 2959 struct in_addr faddr; 2960 struct inpcb *inp; 2961 struct tcpcb *tp; 2962 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2963 struct icmp *icp; 2964 struct in_conninfo inc; 2965 tcp_seq icmp_tcp_seq; 2966 int mtu; 2967 2968 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2969 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2970 return; 2971 2972 if (cmd == PRC_MSGSIZE) 2973 notify = tcp_mtudisc_notify; 2974 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2975 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2976 cmd == PRC_TIMXCEED_INTRANS) && ip) 2977 notify = tcp_drop_syn_sent; 2978 2979 /* 2980 * Hostdead is ugly because it goes linearly through all PCBs. 2981 * XXX: We never get this from ICMP, otherwise it makes an 2982 * excellent DoS attack on machines with many connections. 2983 */ 2984 else if (cmd == PRC_HOSTDEAD) 2985 ip = NULL; 2986 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2987 return; 2988 2989 if (ip == NULL) { 2990 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2991 return; 2992 } 2993 2994 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2995 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2996 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2997 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2998 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2999 /* signal EHOSTDOWN, as it flushes the cached route */ 3000 inp = (*notify)(inp, EHOSTDOWN); 3001 goto out; 3002 } 3003 icmp_tcp_seq = th->th_seq; 3004 if (inp != NULL) { 3005 if (!(inp->inp_flags & INP_TIMEWAIT) && 3006 !(inp->inp_flags & INP_DROPPED) && 3007 !(inp->inp_socket == NULL)) { 3008 tp = intotcpcb(inp); 3009 #ifdef TCP_OFFLOAD 3010 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3011 /* 3012 * MTU discovery for offloaded connections. Let 3013 * the TOE driver verify seq# and process it. 3014 */ 3015 mtu = tcp_next_pmtu(icp, ip); 3016 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3017 goto out; 3018 } 3019 #endif 3020 if (tp->t_port != port) { 3021 goto out; 3022 } 3023 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3024 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3025 if (cmd == PRC_MSGSIZE) { 3026 /* 3027 * MTU discovery: we got a needfrag and 3028 * will potentially try a lower MTU. 3029 */ 3030 mtu = tcp_next_pmtu(icp, ip); 3031 3032 /* 3033 * Only process the offered MTU if it 3034 * is smaller than the current one. 3035 */ 3036 if (mtu < tp->t_maxseg + 3037 sizeof(struct tcpiphdr)) { 3038 bzero(&inc, sizeof(inc)); 3039 inc.inc_faddr = faddr; 3040 inc.inc_fibnum = 3041 inp->inp_inc.inc_fibnum; 3042 tcp_hc_updatemtu(&inc, mtu); 3043 tcp_mtudisc(inp, mtu); 3044 } 3045 } else 3046 inp = (*notify)(inp, 3047 inetctlerrmap[cmd]); 3048 } 3049 } 3050 } else { 3051 bzero(&inc, sizeof(inc)); 3052 inc.inc_fport = th->th_dport; 3053 inc.inc_lport = th->th_sport; 3054 inc.inc_faddr = faddr; 3055 inc.inc_laddr = ip->ip_src; 3056 syncache_unreach(&inc, icmp_tcp_seq, port); 3057 } 3058 out: 3059 if (inp != NULL) 3060 INP_WUNLOCK(inp); 3061 } 3062 3063 void 3064 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 3065 { 3066 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 3067 } 3068 3069 void 3070 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 3071 { 3072 /* Its a tunneled TCP over UDP icmp */ 3073 struct ip *outer_ip, *inner_ip; 3074 struct icmp *icmp; 3075 struct udphdr *udp; 3076 struct tcphdr *th, ttemp; 3077 int i_hlen, o_len; 3078 uint16_t port; 3079 3080 inner_ip = (struct ip *)vip; 3081 icmp = (struct icmp *)((caddr_t)inner_ip - 3082 (sizeof(struct icmp) - sizeof(struct ip))); 3083 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 3084 i_hlen = inner_ip->ip_hl << 2; 3085 o_len = ntohs(outer_ip->ip_len); 3086 if (o_len < 3087 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 3088 /* Not enough data present */ 3089 return; 3090 } 3091 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 3092 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 3093 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3094 return; 3095 } 3096 port = udp->uh_dport; 3097 th = (struct tcphdr *)(udp + 1); 3098 memcpy(&ttemp, th, sizeof(struct tcphdr)); 3099 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 3100 /* Now adjust down the size of the outer IP header */ 3101 o_len -= sizeof(struct udphdr); 3102 outer_ip->ip_len = htons(o_len); 3103 /* Now call in to the normal handling code */ 3104 tcp_ctlinput_with_port(cmd, sa, vip, port); 3105 } 3106 #endif /* INET */ 3107 3108 #ifdef INET6 3109 static inline int 3110 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 3111 { 3112 int mtu = ntohl(icmp6->icmp6_mtu); 3113 3114 /* 3115 * If no alternative MTU was proposed, or the proposed MTU was too 3116 * small, set to the min. 3117 */ 3118 if (mtu < IPV6_MMTU) 3119 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3120 return (mtu); 3121 } 3122 3123 static void 3124 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3125 { 3126 struct in6_addr *dst; 3127 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3128 struct ip6_hdr *ip6; 3129 struct mbuf *m; 3130 struct inpcb *inp; 3131 struct tcpcb *tp; 3132 struct icmp6_hdr *icmp6; 3133 struct ip6ctlparam *ip6cp = NULL; 3134 const struct sockaddr_in6 *sa6_src = NULL; 3135 struct in_conninfo inc; 3136 struct tcp_ports { 3137 uint16_t th_sport; 3138 uint16_t th_dport; 3139 } t_ports; 3140 tcp_seq icmp_tcp_seq; 3141 unsigned int mtu; 3142 unsigned int off; 3143 3144 if (sa->sa_family != AF_INET6 || 3145 sa->sa_len != sizeof(struct sockaddr_in6)) 3146 return; 3147 3148 /* if the parameter is from icmp6, decode it. */ 3149 if (d != NULL) { 3150 ip6cp = (struct ip6ctlparam *)d; 3151 icmp6 = ip6cp->ip6c_icmp6; 3152 m = ip6cp->ip6c_m; 3153 ip6 = ip6cp->ip6c_ip6; 3154 off = ip6cp->ip6c_off; 3155 sa6_src = ip6cp->ip6c_src; 3156 dst = ip6cp->ip6c_finaldst; 3157 } else { 3158 m = NULL; 3159 ip6 = NULL; 3160 off = 0; /* fool gcc */ 3161 sa6_src = &sa6_any; 3162 dst = NULL; 3163 } 3164 3165 if (cmd == PRC_MSGSIZE) 3166 notify = tcp_mtudisc_notify; 3167 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3168 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3169 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3170 notify = tcp_drop_syn_sent; 3171 3172 /* 3173 * Hostdead is ugly because it goes linearly through all PCBs. 3174 * XXX: We never get this from ICMP, otherwise it makes an 3175 * excellent DoS attack on machines with many connections. 3176 */ 3177 else if (cmd == PRC_HOSTDEAD) 3178 ip6 = NULL; 3179 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3180 return; 3181 3182 if (ip6 == NULL) { 3183 in6_pcbnotify(&V_tcbinfo, sa, 0, 3184 (const struct sockaddr *)sa6_src, 3185 0, cmd, NULL, notify); 3186 return; 3187 } 3188 3189 /* Check if we can safely get the ports from the tcp hdr */ 3190 if (m == NULL || 3191 (m->m_pkthdr.len < 3192 (int32_t) (off + sizeof(struct tcp_ports)))) { 3193 return; 3194 } 3195 bzero(&t_ports, sizeof(struct tcp_ports)); 3196 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3197 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3198 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3199 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3200 /* signal EHOSTDOWN, as it flushes the cached route */ 3201 inp = (*notify)(inp, EHOSTDOWN); 3202 goto out; 3203 } 3204 off += sizeof(struct tcp_ports); 3205 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3206 goto out; 3207 } 3208 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3209 if (inp != NULL) { 3210 if (!(inp->inp_flags & INP_TIMEWAIT) && 3211 !(inp->inp_flags & INP_DROPPED) && 3212 !(inp->inp_socket == NULL)) { 3213 tp = intotcpcb(inp); 3214 #ifdef TCP_OFFLOAD 3215 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3216 /* MTU discovery for offloaded connections. */ 3217 mtu = tcp6_next_pmtu(icmp6); 3218 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3219 goto out; 3220 } 3221 #endif 3222 if (tp->t_port != port) { 3223 goto out; 3224 } 3225 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3226 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3227 if (cmd == PRC_MSGSIZE) { 3228 /* 3229 * MTU discovery: 3230 * If we got a needfrag set the MTU 3231 * in the route to the suggested new 3232 * value (if given) and then notify. 3233 */ 3234 mtu = tcp6_next_pmtu(icmp6); 3235 3236 bzero(&inc, sizeof(inc)); 3237 inc.inc_fibnum = M_GETFIB(m); 3238 inc.inc_flags |= INC_ISIPV6; 3239 inc.inc6_faddr = *dst; 3240 if (in6_setscope(&inc.inc6_faddr, 3241 m->m_pkthdr.rcvif, NULL)) 3242 goto out; 3243 /* 3244 * Only process the offered MTU if it 3245 * is smaller than the current one. 3246 */ 3247 if (mtu < tp->t_maxseg + 3248 sizeof (struct tcphdr) + 3249 sizeof (struct ip6_hdr)) { 3250 tcp_hc_updatemtu(&inc, mtu); 3251 tcp_mtudisc(inp, mtu); 3252 ICMP6STAT_INC(icp6s_pmtuchg); 3253 } 3254 } else 3255 inp = (*notify)(inp, 3256 inet6ctlerrmap[cmd]); 3257 } 3258 } 3259 } else { 3260 bzero(&inc, sizeof(inc)); 3261 inc.inc_fibnum = M_GETFIB(m); 3262 inc.inc_flags |= INC_ISIPV6; 3263 inc.inc_fport = t_ports.th_dport; 3264 inc.inc_lport = t_ports.th_sport; 3265 inc.inc6_faddr = *dst; 3266 inc.inc6_laddr = ip6->ip6_src; 3267 syncache_unreach(&inc, icmp_tcp_seq, port); 3268 } 3269 out: 3270 if (inp != NULL) 3271 INP_WUNLOCK(inp); 3272 } 3273 3274 void 3275 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3276 { 3277 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3278 } 3279 3280 void 3281 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3282 { 3283 struct ip6ctlparam *ip6cp; 3284 struct mbuf *m; 3285 struct udphdr *udp; 3286 uint16_t port; 3287 3288 ip6cp = (struct ip6ctlparam *)d; 3289 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3290 if (m == NULL) { 3291 return; 3292 } 3293 udp = mtod(m, struct udphdr *); 3294 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3295 return; 3296 } 3297 port = udp->uh_dport; 3298 m_adj(m, sizeof(struct udphdr)); 3299 if ((m->m_flags & M_PKTHDR) == 0) { 3300 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3301 } 3302 /* Now call in to the normal handling code */ 3303 tcp6_ctlinput_with_port(cmd, sa, d, port); 3304 } 3305 3306 #endif /* INET6 */ 3307 3308 static uint32_t 3309 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3310 { 3311 SIPHASH_CTX ctx; 3312 uint32_t hash[2]; 3313 3314 KASSERT(len >= SIPHASH_KEY_LENGTH, 3315 ("%s: keylen %u too short ", __func__, len)); 3316 SipHash24_Init(&ctx); 3317 SipHash_SetKey(&ctx, (uint8_t *)key); 3318 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3319 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3320 switch (inc->inc_flags & INC_ISIPV6) { 3321 #ifdef INET 3322 case 0: 3323 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3324 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3325 break; 3326 #endif 3327 #ifdef INET6 3328 case INC_ISIPV6: 3329 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3330 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3331 break; 3332 #endif 3333 } 3334 SipHash_Final((uint8_t *)hash, &ctx); 3335 3336 return (hash[0] ^ hash[1]); 3337 } 3338 3339 uint32_t 3340 tcp_new_ts_offset(struct in_conninfo *inc) 3341 { 3342 struct in_conninfo inc_store, *local_inc; 3343 3344 if (!V_tcp_ts_offset_per_conn) { 3345 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3346 inc_store.inc_lport = 0; 3347 inc_store.inc_fport = 0; 3348 local_inc = &inc_store; 3349 } else { 3350 local_inc = inc; 3351 } 3352 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3353 sizeof(V_ts_offset_secret))); 3354 } 3355 3356 /* 3357 * Following is where TCP initial sequence number generation occurs. 3358 * 3359 * There are two places where we must use initial sequence numbers: 3360 * 1. In SYN-ACK packets. 3361 * 2. In SYN packets. 3362 * 3363 * All ISNs for SYN-ACK packets are generated by the syncache. See 3364 * tcp_syncache.c for details. 3365 * 3366 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3367 * depends on this property. In addition, these ISNs should be 3368 * unguessable so as to prevent connection hijacking. To satisfy 3369 * the requirements of this situation, the algorithm outlined in 3370 * RFC 1948 is used, with only small modifications. 3371 * 3372 * Implementation details: 3373 * 3374 * Time is based off the system timer, and is corrected so that it 3375 * increases by one megabyte per second. This allows for proper 3376 * recycling on high speed LANs while still leaving over an hour 3377 * before rollover. 3378 * 3379 * As reading the *exact* system time is too expensive to be done 3380 * whenever setting up a TCP connection, we increment the time 3381 * offset in two ways. First, a small random positive increment 3382 * is added to isn_offset for each connection that is set up. 3383 * Second, the function tcp_isn_tick fires once per clock tick 3384 * and increments isn_offset as necessary so that sequence numbers 3385 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3386 * random positive increments serve only to ensure that the same 3387 * exact sequence number is never sent out twice (as could otherwise 3388 * happen when a port is recycled in less than the system tick 3389 * interval.) 3390 * 3391 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3392 * between seeding of isn_secret. This is normally set to zero, 3393 * as reseeding should not be necessary. 3394 * 3395 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3396 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3397 * general, this means holding an exclusive (write) lock. 3398 */ 3399 3400 #define ISN_BYTES_PER_SECOND 1048576 3401 #define ISN_STATIC_INCREMENT 4096 3402 #define ISN_RANDOM_INCREMENT (4096 - 1) 3403 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3404 3405 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3406 VNET_DEFINE_STATIC(int, isn_last); 3407 VNET_DEFINE_STATIC(int, isn_last_reseed); 3408 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3409 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3410 3411 #define V_isn_secret VNET(isn_secret) 3412 #define V_isn_last VNET(isn_last) 3413 #define V_isn_last_reseed VNET(isn_last_reseed) 3414 #define V_isn_offset VNET(isn_offset) 3415 #define V_isn_offset_old VNET(isn_offset_old) 3416 3417 tcp_seq 3418 tcp_new_isn(struct in_conninfo *inc) 3419 { 3420 tcp_seq new_isn; 3421 u_int32_t projected_offset; 3422 3423 ISN_LOCK(); 3424 /* Seed if this is the first use, reseed if requested. */ 3425 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3426 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3427 < (u_int)ticks))) { 3428 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3429 V_isn_last_reseed = ticks; 3430 } 3431 3432 /* Compute the hash and return the ISN. */ 3433 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3434 sizeof(V_isn_secret)); 3435 V_isn_offset += ISN_STATIC_INCREMENT + 3436 (arc4random() & ISN_RANDOM_INCREMENT); 3437 if (ticks != V_isn_last) { 3438 projected_offset = V_isn_offset_old + 3439 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3440 if (SEQ_GT(projected_offset, V_isn_offset)) 3441 V_isn_offset = projected_offset; 3442 V_isn_offset_old = V_isn_offset; 3443 V_isn_last = ticks; 3444 } 3445 new_isn += V_isn_offset; 3446 ISN_UNLOCK(); 3447 return (new_isn); 3448 } 3449 3450 /* 3451 * When a specific ICMP unreachable message is received and the 3452 * connection state is SYN-SENT, drop the connection. This behavior 3453 * is controlled by the icmp_may_rst sysctl. 3454 */ 3455 struct inpcb * 3456 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3457 { 3458 struct tcpcb *tp; 3459 3460 NET_EPOCH_ASSERT(); 3461 INP_WLOCK_ASSERT(inp); 3462 3463 if ((inp->inp_flags & INP_TIMEWAIT) || 3464 (inp->inp_flags & INP_DROPPED)) 3465 return (inp); 3466 3467 tp = intotcpcb(inp); 3468 if (tp->t_state != TCPS_SYN_SENT) 3469 return (inp); 3470 3471 if (IS_FASTOPEN(tp->t_flags)) 3472 tcp_fastopen_disable_path(tp); 3473 3474 tp = tcp_drop(tp, errno); 3475 if (tp != NULL) 3476 return (inp); 3477 else 3478 return (NULL); 3479 } 3480 3481 /* 3482 * When `need fragmentation' ICMP is received, update our idea of the MSS 3483 * based on the new value. Also nudge TCP to send something, since we 3484 * know the packet we just sent was dropped. 3485 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3486 */ 3487 static struct inpcb * 3488 tcp_mtudisc_notify(struct inpcb *inp, int error) 3489 { 3490 3491 tcp_mtudisc(inp, -1); 3492 return (inp); 3493 } 3494 3495 static void 3496 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3497 { 3498 struct tcpcb *tp; 3499 struct socket *so; 3500 3501 INP_WLOCK_ASSERT(inp); 3502 if ((inp->inp_flags & INP_TIMEWAIT) || 3503 (inp->inp_flags & INP_DROPPED)) 3504 return; 3505 3506 tp = intotcpcb(inp); 3507 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3508 3509 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3510 3511 so = inp->inp_socket; 3512 SOCKBUF_LOCK(&so->so_snd); 3513 /* If the mss is larger than the socket buffer, decrease the mss. */ 3514 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3515 tp->t_maxseg = so->so_snd.sb_hiwat; 3516 SOCKBUF_UNLOCK(&so->so_snd); 3517 3518 TCPSTAT_INC(tcps_mturesent); 3519 tp->t_rtttime = 0; 3520 tp->snd_nxt = tp->snd_una; 3521 tcp_free_sackholes(tp); 3522 tp->snd_recover = tp->snd_max; 3523 if (tp->t_flags & TF_SACK_PERMIT) 3524 EXIT_FASTRECOVERY(tp->t_flags); 3525 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3526 /* 3527 * Conceptually the snd_nxt setting 3528 * and freeing sack holes should 3529 * be done by the default stacks 3530 * own tfb_tcp_mtu_chg(). 3531 */ 3532 tp->t_fb->tfb_tcp_mtu_chg(tp); 3533 } 3534 tp->t_fb->tfb_tcp_output(tp); 3535 } 3536 3537 #ifdef INET 3538 /* 3539 * Look-up the routing entry to the peer of this inpcb. If no route 3540 * is found and it cannot be allocated, then return 0. This routine 3541 * is called by TCP routines that access the rmx structure and by 3542 * tcp_mss_update to get the peer/interface MTU. 3543 */ 3544 uint32_t 3545 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3546 { 3547 struct nhop_object *nh; 3548 struct ifnet *ifp; 3549 uint32_t maxmtu = 0; 3550 3551 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3552 3553 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3554 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3555 if (nh == NULL) 3556 return (0); 3557 3558 ifp = nh->nh_ifp; 3559 maxmtu = nh->nh_mtu; 3560 3561 /* Report additional interface capabilities. */ 3562 if (cap != NULL) { 3563 if (ifp->if_capenable & IFCAP_TSO4 && 3564 ifp->if_hwassist & CSUM_TSO) { 3565 cap->ifcap |= CSUM_TSO; 3566 cap->tsomax = ifp->if_hw_tsomax; 3567 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3568 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3569 } 3570 } 3571 } 3572 return (maxmtu); 3573 } 3574 #endif /* INET */ 3575 3576 #ifdef INET6 3577 uint32_t 3578 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3579 { 3580 struct nhop_object *nh; 3581 struct in6_addr dst6; 3582 uint32_t scopeid; 3583 struct ifnet *ifp; 3584 uint32_t maxmtu = 0; 3585 3586 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3587 3588 if (inc->inc_flags & INC_IPV6MINMTU) 3589 return (IPV6_MMTU); 3590 3591 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3592 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3593 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3594 if (nh == NULL) 3595 return (0); 3596 3597 ifp = nh->nh_ifp; 3598 maxmtu = nh->nh_mtu; 3599 3600 /* Report additional interface capabilities. */ 3601 if (cap != NULL) { 3602 if (ifp->if_capenable & IFCAP_TSO6 && 3603 ifp->if_hwassist & CSUM_TSO) { 3604 cap->ifcap |= CSUM_TSO; 3605 cap->tsomax = ifp->if_hw_tsomax; 3606 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3607 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3608 } 3609 } 3610 } 3611 3612 return (maxmtu); 3613 } 3614 3615 /* 3616 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3617 * 3618 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3619 * The right place to do that is ip6_setpktopt() that has just been 3620 * executed. By the way it just filled ip6po_minmtu for us. 3621 */ 3622 void 3623 tcp6_use_min_mtu(struct tcpcb *tp) 3624 { 3625 struct inpcb *inp = tp->t_inpcb; 3626 3627 INP_WLOCK_ASSERT(inp); 3628 /* 3629 * In case of the IPV6_USE_MIN_MTU socket 3630 * option, the INC_IPV6MINMTU flag to announce 3631 * a corresponding MSS during the initial 3632 * handshake. If the TCP connection is not in 3633 * the front states, just reduce the MSS being 3634 * used. This avoids the sending of TCP 3635 * segments which will be fragmented at the 3636 * IPv6 layer. 3637 */ 3638 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3639 if ((tp->t_state >= TCPS_SYN_SENT) && 3640 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3641 struct ip6_pktopts *opt; 3642 3643 opt = inp->in6p_outputopts; 3644 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3645 tp->t_maxseg > TCP6_MSS) 3646 tp->t_maxseg = TCP6_MSS; 3647 } 3648 } 3649 #endif /* INET6 */ 3650 3651 /* 3652 * Calculate effective SMSS per RFC5681 definition for a given TCP 3653 * connection at its current state, taking into account SACK and etc. 3654 */ 3655 u_int 3656 tcp_maxseg(const struct tcpcb *tp) 3657 { 3658 u_int optlen; 3659 3660 if (tp->t_flags & TF_NOOPT) 3661 return (tp->t_maxseg); 3662 3663 /* 3664 * Here we have a simplified code from tcp_addoptions(), 3665 * without a proper loop, and having most of paddings hardcoded. 3666 * We might make mistakes with padding here in some edge cases, 3667 * but this is harmless, since result of tcp_maxseg() is used 3668 * only in cwnd and ssthresh estimations. 3669 */ 3670 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3671 if (tp->t_flags & TF_RCVD_TSTMP) 3672 optlen = TCPOLEN_TSTAMP_APPA; 3673 else 3674 optlen = 0; 3675 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3676 if (tp->t_flags & TF_SIGNATURE) 3677 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3678 #endif 3679 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3680 optlen += TCPOLEN_SACKHDR; 3681 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3682 optlen = PADTCPOLEN(optlen); 3683 } 3684 } else { 3685 if (tp->t_flags & TF_REQ_TSTMP) 3686 optlen = TCPOLEN_TSTAMP_APPA; 3687 else 3688 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3689 if (tp->t_flags & TF_REQ_SCALE) 3690 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3691 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3692 if (tp->t_flags & TF_SIGNATURE) 3693 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3694 #endif 3695 if (tp->t_flags & TF_SACK_PERMIT) 3696 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3697 } 3698 #undef PAD 3699 optlen = min(optlen, TCP_MAXOLEN); 3700 return (tp->t_maxseg - optlen); 3701 } 3702 3703 3704 u_int 3705 tcp_fixed_maxseg(const struct tcpcb *tp) 3706 { 3707 int optlen; 3708 3709 if (tp->t_flags & TF_NOOPT) 3710 return (tp->t_maxseg); 3711 3712 /* 3713 * Here we have a simplified code from tcp_addoptions(), 3714 * without a proper loop, and having most of paddings hardcoded. 3715 * We only consider fixed options that we would send every 3716 * time I.e. SACK is not considered. This is important 3717 * for cc modules to figure out what the modulo of the 3718 * cwnd should be. 3719 */ 3720 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3721 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3722 if (tp->t_flags & TF_RCVD_TSTMP) 3723 optlen = TCPOLEN_TSTAMP_APPA; 3724 else 3725 optlen = 0; 3726 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3727 if (tp->t_flags & TF_SIGNATURE) 3728 optlen += PAD(TCPOLEN_SIGNATURE); 3729 #endif 3730 } else { 3731 if (tp->t_flags & TF_REQ_TSTMP) 3732 optlen = TCPOLEN_TSTAMP_APPA; 3733 else 3734 optlen = PAD(TCPOLEN_MAXSEG); 3735 if (tp->t_flags & TF_REQ_SCALE) 3736 optlen += PAD(TCPOLEN_WINDOW); 3737 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3738 if (tp->t_flags & TF_SIGNATURE) 3739 optlen += PAD(TCPOLEN_SIGNATURE); 3740 #endif 3741 if (tp->t_flags & TF_SACK_PERMIT) 3742 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3743 } 3744 #undef PAD 3745 optlen = min(optlen, TCP_MAXOLEN); 3746 return (tp->t_maxseg - optlen); 3747 } 3748 3749 3750 3751 static int 3752 sysctl_drop(SYSCTL_HANDLER_ARGS) 3753 { 3754 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3755 struct sockaddr_storage addrs[2]; 3756 struct inpcb *inp; 3757 struct tcpcb *tp; 3758 struct tcptw *tw; 3759 struct sockaddr_in *fin, *lin; 3760 struct epoch_tracker et; 3761 #ifdef INET6 3762 struct sockaddr_in6 *fin6, *lin6; 3763 #endif 3764 int error; 3765 3766 inp = NULL; 3767 fin = lin = NULL; 3768 #ifdef INET6 3769 fin6 = lin6 = NULL; 3770 #endif 3771 error = 0; 3772 3773 if (req->oldptr != NULL || req->oldlen != 0) 3774 return (EINVAL); 3775 if (req->newptr == NULL) 3776 return (EPERM); 3777 if (req->newlen < sizeof(addrs)) 3778 return (ENOMEM); 3779 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3780 if (error) 3781 return (error); 3782 3783 switch (addrs[0].ss_family) { 3784 #ifdef INET6 3785 case AF_INET6: 3786 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3787 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3788 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3789 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3790 return (EINVAL); 3791 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3792 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3793 return (EINVAL); 3794 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3795 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3796 fin = (struct sockaddr_in *)&addrs[0]; 3797 lin = (struct sockaddr_in *)&addrs[1]; 3798 break; 3799 } 3800 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3801 if (error) 3802 return (error); 3803 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3804 if (error) 3805 return (error); 3806 break; 3807 #endif 3808 #ifdef INET 3809 case AF_INET: 3810 fin = (struct sockaddr_in *)&addrs[0]; 3811 lin = (struct sockaddr_in *)&addrs[1]; 3812 if (fin->sin_len != sizeof(struct sockaddr_in) || 3813 lin->sin_len != sizeof(struct sockaddr_in)) 3814 return (EINVAL); 3815 break; 3816 #endif 3817 default: 3818 return (EINVAL); 3819 } 3820 NET_EPOCH_ENTER(et); 3821 switch (addrs[0].ss_family) { 3822 #ifdef INET6 3823 case AF_INET6: 3824 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3825 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3826 INPLOOKUP_WLOCKPCB, NULL); 3827 break; 3828 #endif 3829 #ifdef INET 3830 case AF_INET: 3831 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3832 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3833 break; 3834 #endif 3835 } 3836 if (inp != NULL) { 3837 if (inp->inp_flags & INP_TIMEWAIT) { 3838 /* 3839 * XXXRW: There currently exists a state where an 3840 * inpcb is present, but its timewait state has been 3841 * discarded. For now, don't allow dropping of this 3842 * type of inpcb. 3843 */ 3844 tw = intotw(inp); 3845 if (tw != NULL) 3846 tcp_twclose(tw, 0); 3847 else 3848 INP_WUNLOCK(inp); 3849 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3850 !SOLISTENING(inp->inp_socket)) { 3851 tp = intotcpcb(inp); 3852 tp = tcp_drop(tp, ECONNABORTED); 3853 if (tp != NULL) 3854 INP_WUNLOCK(inp); 3855 } else 3856 INP_WUNLOCK(inp); 3857 } else 3858 error = ESRCH; 3859 NET_EPOCH_EXIT(et); 3860 return (error); 3861 } 3862 3863 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3864 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3865 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3866 "Drop TCP connection"); 3867 3868 #ifdef KERN_TLS 3869 static int 3870 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3871 { 3872 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3873 struct sockaddr_storage addrs[2]; 3874 struct inpcb *inp; 3875 struct sockaddr_in *fin, *lin; 3876 struct epoch_tracker et; 3877 #ifdef INET6 3878 struct sockaddr_in6 *fin6, *lin6; 3879 #endif 3880 int error; 3881 3882 inp = NULL; 3883 fin = lin = NULL; 3884 #ifdef INET6 3885 fin6 = lin6 = NULL; 3886 #endif 3887 error = 0; 3888 3889 if (req->oldptr != NULL || req->oldlen != 0) 3890 return (EINVAL); 3891 if (req->newptr == NULL) 3892 return (EPERM); 3893 if (req->newlen < sizeof(addrs)) 3894 return (ENOMEM); 3895 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3896 if (error) 3897 return (error); 3898 3899 switch (addrs[0].ss_family) { 3900 #ifdef INET6 3901 case AF_INET6: 3902 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3903 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3904 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3905 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3906 return (EINVAL); 3907 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3908 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3909 return (EINVAL); 3910 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3911 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3912 fin = (struct sockaddr_in *)&addrs[0]; 3913 lin = (struct sockaddr_in *)&addrs[1]; 3914 break; 3915 } 3916 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3917 if (error) 3918 return (error); 3919 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3920 if (error) 3921 return (error); 3922 break; 3923 #endif 3924 #ifdef INET 3925 case AF_INET: 3926 fin = (struct sockaddr_in *)&addrs[0]; 3927 lin = (struct sockaddr_in *)&addrs[1]; 3928 if (fin->sin_len != sizeof(struct sockaddr_in) || 3929 lin->sin_len != sizeof(struct sockaddr_in)) 3930 return (EINVAL); 3931 break; 3932 #endif 3933 default: 3934 return (EINVAL); 3935 } 3936 NET_EPOCH_ENTER(et); 3937 switch (addrs[0].ss_family) { 3938 #ifdef INET6 3939 case AF_INET6: 3940 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3941 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3942 INPLOOKUP_WLOCKPCB, NULL); 3943 break; 3944 #endif 3945 #ifdef INET 3946 case AF_INET: 3947 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3948 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3949 break; 3950 #endif 3951 } 3952 NET_EPOCH_EXIT(et); 3953 if (inp != NULL) { 3954 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3955 inp->inp_socket == NULL) { 3956 error = ECONNRESET; 3957 INP_WUNLOCK(inp); 3958 } else { 3959 struct socket *so; 3960 3961 so = inp->inp_socket; 3962 soref(so); 3963 error = ktls_set_tx_mode(so, 3964 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3965 INP_WUNLOCK(inp); 3966 sorele(so); 3967 } 3968 } else 3969 error = ESRCH; 3970 return (error); 3971 } 3972 3973 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3974 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3975 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3976 "Switch TCP connection to SW TLS"); 3977 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3978 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3979 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3980 "Switch TCP connection to ifnet TLS"); 3981 #endif 3982 3983 /* 3984 * Generate a standardized TCP log line for use throughout the 3985 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3986 * allow use in the interrupt context. 3987 * 3988 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3989 * NB: The function may return NULL if memory allocation failed. 3990 * 3991 * Due to header inclusion and ordering limitations the struct ip 3992 * and ip6_hdr pointers have to be passed as void pointers. 3993 */ 3994 char * 3995 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3996 const void *ip6hdr) 3997 { 3998 3999 /* Is logging enabled? */ 4000 if (V_tcp_log_in_vain == 0) 4001 return (NULL); 4002 4003 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 4004 } 4005 4006 char * 4007 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 4008 const void *ip6hdr) 4009 { 4010 4011 /* Is logging enabled? */ 4012 if (tcp_log_debug == 0) 4013 return (NULL); 4014 4015 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 4016 } 4017 4018 static char * 4019 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 4020 const void *ip6hdr) 4021 { 4022 char *s, *sp; 4023 size_t size; 4024 struct ip *ip; 4025 #ifdef INET6 4026 const struct ip6_hdr *ip6; 4027 4028 ip6 = (const struct ip6_hdr *)ip6hdr; 4029 #endif /* INET6 */ 4030 ip = (struct ip *)ip4hdr; 4031 4032 /* 4033 * The log line looks like this: 4034 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 4035 */ 4036 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 4037 sizeof(PRINT_TH_FLAGS) + 1 + 4038 #ifdef INET6 4039 2 * INET6_ADDRSTRLEN; 4040 #else 4041 2 * INET_ADDRSTRLEN; 4042 #endif /* INET6 */ 4043 4044 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 4045 if (s == NULL) 4046 return (NULL); 4047 4048 strcat(s, "TCP: ["); 4049 sp = s + strlen(s); 4050 4051 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 4052 inet_ntoa_r(inc->inc_faddr, sp); 4053 sp = s + strlen(s); 4054 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 4055 sp = s + strlen(s); 4056 inet_ntoa_r(inc->inc_laddr, sp); 4057 sp = s + strlen(s); 4058 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 4059 #ifdef INET6 4060 } else if (inc) { 4061 ip6_sprintf(sp, &inc->inc6_faddr); 4062 sp = s + strlen(s); 4063 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 4064 sp = s + strlen(s); 4065 ip6_sprintf(sp, &inc->inc6_laddr); 4066 sp = s + strlen(s); 4067 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 4068 } else if (ip6 && th) { 4069 ip6_sprintf(sp, &ip6->ip6_src); 4070 sp = s + strlen(s); 4071 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 4072 sp = s + strlen(s); 4073 ip6_sprintf(sp, &ip6->ip6_dst); 4074 sp = s + strlen(s); 4075 sprintf(sp, "]:%i", ntohs(th->th_dport)); 4076 #endif /* INET6 */ 4077 #ifdef INET 4078 } else if (ip && th) { 4079 inet_ntoa_r(ip->ip_src, sp); 4080 sp = s + strlen(s); 4081 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 4082 sp = s + strlen(s); 4083 inet_ntoa_r(ip->ip_dst, sp); 4084 sp = s + strlen(s); 4085 sprintf(sp, "]:%i", ntohs(th->th_dport)); 4086 #endif /* INET */ 4087 } else { 4088 free(s, M_TCPLOG); 4089 return (NULL); 4090 } 4091 sp = s + strlen(s); 4092 if (th) 4093 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 4094 if (*(s + size - 1) != '\0') 4095 panic("%s: string too long", __func__); 4096 return (s); 4097 } 4098 4099 /* 4100 * A subroutine which makes it easy to track TCP state changes with DTrace. 4101 * This function shouldn't be called for t_state initializations that don't 4102 * correspond to actual TCP state transitions. 4103 */ 4104 void 4105 tcp_state_change(struct tcpcb *tp, int newstate) 4106 { 4107 #if defined(KDTRACE_HOOKS) 4108 int pstate = tp->t_state; 4109 #endif 4110 4111 TCPSTATES_DEC(tp->t_state); 4112 TCPSTATES_INC(newstate); 4113 tp->t_state = newstate; 4114 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 4115 } 4116 4117 /* 4118 * Create an external-format (``xtcpcb'') structure using the information in 4119 * the kernel-format tcpcb structure pointed to by tp. This is done to 4120 * reduce the spew of irrelevant information over this interface, to isolate 4121 * user code from changes in the kernel structure, and potentially to provide 4122 * information-hiding if we decide that some of this information should be 4123 * hidden from users. 4124 */ 4125 void 4126 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 4127 { 4128 struct tcpcb *tp = intotcpcb(inp); 4129 struct tcptw *tw = intotw(inp); 4130 sbintime_t now; 4131 4132 bzero(xt, sizeof(*xt)); 4133 if (inp->inp_flags & INP_TIMEWAIT) { 4134 xt->t_state = TCPS_TIME_WAIT; 4135 xt->xt_encaps_port = tw->t_port; 4136 } else { 4137 xt->t_state = tp->t_state; 4138 xt->t_logstate = tp->t_logstate; 4139 xt->t_flags = tp->t_flags; 4140 xt->t_sndzerowin = tp->t_sndzerowin; 4141 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4142 xt->t_rcvoopack = tp->t_rcvoopack; 4143 xt->t_rcv_wnd = tp->rcv_wnd; 4144 xt->t_snd_wnd = tp->snd_wnd; 4145 xt->t_snd_cwnd = tp->snd_cwnd; 4146 xt->t_snd_ssthresh = tp->snd_ssthresh; 4147 xt->t_dsack_bytes = tp->t_dsack_bytes; 4148 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 4149 xt->t_dsack_pack = tp->t_dsack_pack; 4150 xt->t_maxseg = tp->t_maxseg; 4151 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4152 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4153 4154 now = getsbinuptime(); 4155 #define COPYTIMER(ttt) do { \ 4156 if (callout_active(&tp->t_timers->ttt)) \ 4157 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4158 SBT_1MS; \ 4159 else \ 4160 xt->ttt = 0; \ 4161 } while (0) 4162 COPYTIMER(tt_delack); 4163 COPYTIMER(tt_rexmt); 4164 COPYTIMER(tt_persist); 4165 COPYTIMER(tt_keep); 4166 COPYTIMER(tt_2msl); 4167 #undef COPYTIMER 4168 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4169 4170 xt->xt_encaps_port = tp->t_port; 4171 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4172 TCP_FUNCTION_NAME_LEN_MAX); 4173 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4174 TCP_CA_NAME_MAX); 4175 #ifdef TCP_BLACKBOX 4176 (void)tcp_log_get_id(tp, xt->xt_logid); 4177 #endif 4178 } 4179 4180 xt->xt_len = sizeof(struct xtcpcb); 4181 in_pcbtoxinpcb(inp, &xt->xt_inp); 4182 if (inp->inp_socket == NULL) 4183 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4184 } 4185 4186 void 4187 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4188 { 4189 uint32_t bit, i; 4190 4191 if ((tp == NULL) || 4192 (status > TCP_EI_STATUS_MAX_VALUE) || 4193 (status == 0)) { 4194 /* Invalid */ 4195 return; 4196 } 4197 if (status > (sizeof(uint32_t) * 8)) { 4198 /* Should this be a KASSERT? */ 4199 return; 4200 } 4201 bit = 1U << (status - 1); 4202 if (bit & tp->t_end_info_status) { 4203 /* already logged */ 4204 return; 4205 } 4206 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4207 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4208 tp->t_end_info_bytes[i] = status; 4209 tp->t_end_info_status |= bit; 4210 break; 4211 } 4212 } 4213 } 4214 4215 int 4216 tcp_can_enable_pacing(void) 4217 { 4218 4219 if ((tcp_pacing_limit == -1) || 4220 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4221 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4222 shadow_num_connections = number_of_tcp_connections_pacing; 4223 return (1); 4224 } else { 4225 return (0); 4226 } 4227 } 4228 4229 static uint8_t tcp_pacing_warning = 0; 4230 4231 void 4232 tcp_decrement_paced_conn(void) 4233 { 4234 uint32_t ret; 4235 4236 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4237 shadow_num_connections = number_of_tcp_connections_pacing; 4238 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4239 if (ret == 0) { 4240 if (tcp_pacing_limit != -1) { 4241 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4242 tcp_pacing_limit = 0; 4243 } else if (tcp_pacing_warning == 0) { 4244 printf("Warning pacing count is invalid, invalid decrement\n"); 4245 tcp_pacing_warning = 1; 4246 } 4247 } 4248 } 4249