1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/arb.h> 45 #include <sys/callout.h> 46 #include <sys/eventhandler.h> 47 #ifdef TCP_HHOOK 48 #include <sys/hhook.h> 49 #endif 50 #include <sys/kernel.h> 51 #ifdef TCP_HHOOK 52 #include <sys/khelp.h> 53 #endif 54 #ifdef KERN_TLS 55 #include <sys/ktls.h> 56 #endif 57 #include <sys/qmath.h> 58 #include <sys/stats.h> 59 #include <sys/sysctl.h> 60 #include <sys/jail.h> 61 #include <sys/malloc.h> 62 #include <sys/refcount.h> 63 #include <sys/mbuf.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/sdt.h> 67 #include <sys/socket.h> 68 #include <sys/socketvar.h> 69 #include <sys/protosw.h> 70 #include <sys/random.h> 71 72 #include <vm/uma.h> 73 74 #include <net/route.h> 75 #include <net/route/nhop.h> 76 #include <net/if.h> 77 #include <net/if_var.h> 78 #include <net/if_private.h> 79 #include <net/vnet.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_fib.h> 83 #include <netinet/in_kdtrace.h> 84 #include <netinet/in_pcb.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip.h> 88 #include <netinet/ip_icmp.h> 89 #include <netinet/ip_var.h> 90 #ifdef INET6 91 #include <netinet/icmp6.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/in6_fib.h> 94 #include <netinet6/in6_pcb.h> 95 #include <netinet6/ip6_var.h> 96 #include <netinet6/scope6_var.h> 97 #include <netinet6/nd6.h> 98 #endif 99 100 #include <netinet/tcp.h> 101 #ifdef INVARIANTS 102 #define TCPSTATES 103 #endif 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_ecn.h> 109 #include <netinet/tcp_log_buf.h> 110 #include <netinet/tcp_syncache.h> 111 #include <netinet/tcp_hpts.h> 112 #include <netinet/cc/cc.h> 113 #include <netinet/tcpip.h> 114 #include <netinet/tcp_fastopen.h> 115 #include <netinet/tcp_accounting.h> 116 #ifdef TCPPCAP 117 #include <netinet/tcp_pcap.h> 118 #endif 119 #ifdef TCP_OFFLOAD 120 #include <netinet/tcp_offload.h> 121 #endif 122 #include <netinet/udp.h> 123 #include <netinet/udp_var.h> 124 #ifdef INET6 125 #include <netinet6/tcp6_var.h> 126 #endif 127 128 #include <netipsec/ipsec_support.h> 129 130 #include <machine/in_cksum.h> 131 #include <crypto/siphash/siphash.h> 132 133 #include <security/mac/mac_framework.h> 134 135 #ifdef INET6 136 static ip6proto_ctlinput_t tcp6_ctlinput; 137 static udp_tun_icmp_t tcp6_ctlinput_viaudp; 138 #endif 139 140 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 141 #ifdef INET6 142 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 143 #endif 144 145 #ifdef NETFLIX_EXP_DETECTION 146 /* Sack attack detection thresholds and such */ 147 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 148 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 149 "Sack Attack detection thresholds"); 150 int32_t tcp_force_detection = 0; 151 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 152 CTLFLAG_RW, 153 &tcp_force_detection, 0, 154 "Do we force detection even if the INP has it off?"); 155 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 156 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 157 CTLFLAG_RW, 158 &tcp_sack_to_ack_thresh, 700, 159 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 160 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 161 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 162 CTLFLAG_RW, 163 &tcp_sack_to_move_thresh, 600, 164 "Percentage of sack moves we must see above (10.1 percent is 101)"); 165 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 166 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 167 CTLFLAG_RW, 168 &tcp_restoral_thresh, 550, 169 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 170 int32_t tcp_sad_decay_val = 800; 171 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 172 CTLFLAG_RW, 173 &tcp_sad_decay_val, 800, 174 "The decay percentage (10.1 percent equals 101 )"); 175 int32_t tcp_map_minimum = 500; 176 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 177 CTLFLAG_RW, 178 &tcp_map_minimum, 500, 179 "Number of Map enteries before we start detection"); 180 int32_t tcp_sad_pacing_interval = 2000; 181 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 182 CTLFLAG_RW, 183 &tcp_sad_pacing_interval, 2000, 184 "What is the minimum pacing interval for a classified attacker?"); 185 186 int32_t tcp_sad_low_pps = 100; 187 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 188 CTLFLAG_RW, 189 &tcp_sad_low_pps, 100, 190 "What is the input pps that below which we do not decay?"); 191 #endif 192 uint32_t tcp_ack_war_time_window = 1000; 193 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 194 CTLFLAG_RW, 195 &tcp_ack_war_time_window, 1000, 196 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 197 uint32_t tcp_ack_war_cnt = 5; 198 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 199 CTLFLAG_RW, 200 &tcp_ack_war_cnt, 5, 201 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 202 203 struct rwlock tcp_function_lock; 204 205 static int 206 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 207 { 208 int error, new; 209 210 new = V_tcp_mssdflt; 211 error = sysctl_handle_int(oidp, &new, 0, req); 212 if (error == 0 && req->newptr) { 213 if (new < TCP_MINMSS) 214 error = EINVAL; 215 else 216 V_tcp_mssdflt = new; 217 } 218 return (error); 219 } 220 221 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 222 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 223 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 224 "Default TCP Maximum Segment Size"); 225 226 #ifdef INET6 227 static int 228 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 229 { 230 int error, new; 231 232 new = V_tcp_v6mssdflt; 233 error = sysctl_handle_int(oidp, &new, 0, req); 234 if (error == 0 && req->newptr) { 235 if (new < TCP_MINMSS) 236 error = EINVAL; 237 else 238 V_tcp_v6mssdflt = new; 239 } 240 return (error); 241 } 242 243 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 244 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 245 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 246 "Default TCP Maximum Segment Size for IPv6"); 247 #endif /* INET6 */ 248 249 /* 250 * Minimum MSS we accept and use. This prevents DoS attacks where 251 * we are forced to a ridiculous low MSS like 20 and send hundreds 252 * of packets instead of one. The effect scales with the available 253 * bandwidth and quickly saturates the CPU and network interface 254 * with packet generation and sending. Set to zero to disable MINMSS 255 * checking. This setting prevents us from sending too small packets. 256 */ 257 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 258 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 259 &VNET_NAME(tcp_minmss), 0, 260 "Minimum TCP Maximum Segment Size"); 261 262 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 263 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 264 &VNET_NAME(tcp_do_rfc1323), 0, 265 "Enable rfc1323 (high performance TCP) extensions"); 266 267 /* 268 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 269 * Some stacks negotiate TS, but never send them after connection setup. Some 270 * stacks negotiate TS, but don't send them when sending keep-alive segments. 271 * These include modern widely deployed TCP stacks. 272 * Therefore tolerating violations for now... 273 */ 274 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 275 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 276 &VNET_NAME(tcp_tolerate_missing_ts), 0, 277 "Tolerate missing TCP timestamps"); 278 279 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 280 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 281 &VNET_NAME(tcp_ts_offset_per_conn), 0, 282 "Initialize TCP timestamps per connection instead of per host pair"); 283 284 /* How many connections are pacing */ 285 static volatile uint32_t number_of_tcp_connections_pacing = 0; 286 static uint32_t shadow_num_connections = 0; 287 288 static int tcp_pacing_limit = 10000; 289 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 290 &tcp_pacing_limit, 1000, 291 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 292 293 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 294 &shadow_num_connections, 0, "Number of TCP connections being paced"); 295 296 static int tcp_log_debug = 0; 297 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 298 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 299 300 static int tcp_tcbhashsize; 301 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 302 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 303 304 static int do_tcpdrain = 1; 305 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 306 "Enable tcp_drain routine for extra help when low on mbufs"); 307 308 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 309 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 310 311 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 312 #define V_icmp_may_rst VNET(icmp_may_rst) 313 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 314 &VNET_NAME(icmp_may_rst), 0, 315 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 316 317 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 318 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 319 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 320 &VNET_NAME(tcp_isn_reseed_interval), 0, 321 "Seconds between reseeding of ISN secret"); 322 323 static int tcp_soreceive_stream; 324 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 325 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 326 327 VNET_DEFINE(uma_zone_t, sack_hole_zone); 328 #define V_sack_hole_zone VNET(sack_hole_zone) 329 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 330 static int 331 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 332 { 333 int error; 334 uint32_t new; 335 336 new = V_tcp_map_entries_limit; 337 error = sysctl_handle_int(oidp, &new, 0, req); 338 if (error == 0 && req->newptr) { 339 /* only allow "0" and value > minimum */ 340 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 341 error = EINVAL; 342 else 343 V_tcp_map_entries_limit = new; 344 } 345 return (error); 346 } 347 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 348 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 349 &VNET_NAME(tcp_map_entries_limit), 0, 350 &sysctl_net_inet_tcp_map_limit_check, "IU", 351 "Total sendmap entries limit"); 352 353 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 354 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 355 &VNET_NAME(tcp_map_split_limit), 0, 356 "Total sendmap split entries limit"); 357 358 #ifdef TCP_HHOOK 359 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 360 #endif 361 362 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 363 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 364 #define V_ts_offset_secret VNET(ts_offset_secret) 365 366 static int tcp_default_fb_init(struct tcpcb *tp); 367 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 368 static int tcp_default_handoff_ok(struct tcpcb *tp); 369 static struct inpcb *tcp_notify(struct inpcb *, int); 370 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 371 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 372 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int); 373 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 374 const void *ip4hdr, const void *ip6hdr); 375 static ipproto_ctlinput_t tcp_ctlinput; 376 static udp_tun_icmp_t tcp_ctlinput_viaudp; 377 378 static struct tcp_function_block tcp_def_funcblk = { 379 .tfb_tcp_block_name = "freebsd", 380 .tfb_tcp_output = tcp_default_output, 381 .tfb_tcp_do_segment = tcp_do_segment, 382 .tfb_tcp_ctloutput = tcp_default_ctloutput, 383 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 384 .tfb_tcp_fb_init = tcp_default_fb_init, 385 .tfb_tcp_fb_fini = tcp_default_fb_fini, 386 }; 387 388 static int tcp_fb_cnt = 0; 389 struct tcp_funchead t_functions; 390 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 391 392 void 393 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 394 { 395 TCPSTAT_INC(tcps_dsack_count); 396 tp->t_dsack_pack++; 397 if (tlp == 0) { 398 if (SEQ_GT(end, start)) { 399 tp->t_dsack_bytes += (end - start); 400 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 401 } else { 402 tp->t_dsack_tlp_bytes += (start - end); 403 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 404 } 405 } else { 406 if (SEQ_GT(end, start)) { 407 tp->t_dsack_bytes += (end - start); 408 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 409 } else { 410 tp->t_dsack_tlp_bytes += (start - end); 411 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 412 } 413 } 414 } 415 416 static struct tcp_function_block * 417 find_tcp_functions_locked(struct tcp_function_set *fs) 418 { 419 struct tcp_function *f; 420 struct tcp_function_block *blk=NULL; 421 422 TAILQ_FOREACH(f, &t_functions, tf_next) { 423 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 424 blk = f->tf_fb; 425 break; 426 } 427 } 428 return(blk); 429 } 430 431 static struct tcp_function_block * 432 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 433 { 434 struct tcp_function_block *rblk=NULL; 435 struct tcp_function *f; 436 437 TAILQ_FOREACH(f, &t_functions, tf_next) { 438 if (f->tf_fb == blk) { 439 rblk = blk; 440 if (s) { 441 *s = f; 442 } 443 break; 444 } 445 } 446 return (rblk); 447 } 448 449 struct tcp_function_block * 450 find_and_ref_tcp_functions(struct tcp_function_set *fs) 451 { 452 struct tcp_function_block *blk; 453 454 rw_rlock(&tcp_function_lock); 455 blk = find_tcp_functions_locked(fs); 456 if (blk) 457 refcount_acquire(&blk->tfb_refcnt); 458 rw_runlock(&tcp_function_lock); 459 return(blk); 460 } 461 462 struct tcp_function_block * 463 find_and_ref_tcp_fb(struct tcp_function_block *blk) 464 { 465 struct tcp_function_block *rblk; 466 467 rw_rlock(&tcp_function_lock); 468 rblk = find_tcp_fb_locked(blk, NULL); 469 if (rblk) 470 refcount_acquire(&rblk->tfb_refcnt); 471 rw_runlock(&tcp_function_lock); 472 return(rblk); 473 } 474 475 /* Find a matching alias for the given tcp_function_block. */ 476 int 477 find_tcp_function_alias(struct tcp_function_block *blk, 478 struct tcp_function_set *fs) 479 { 480 struct tcp_function *f; 481 int found; 482 483 found = 0; 484 rw_rlock(&tcp_function_lock); 485 TAILQ_FOREACH(f, &t_functions, tf_next) { 486 if ((f->tf_fb == blk) && 487 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 488 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 489 /* Matching function block with different name. */ 490 strncpy(fs->function_set_name, f->tf_name, 491 TCP_FUNCTION_NAME_LEN_MAX); 492 found = 1; 493 break; 494 } 495 } 496 /* Null terminate the string appropriately. */ 497 if (found) { 498 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 499 } else { 500 fs->function_set_name[0] = '\0'; 501 } 502 rw_runlock(&tcp_function_lock); 503 return (found); 504 } 505 506 static struct tcp_function_block * 507 find_and_ref_tcp_default_fb(void) 508 { 509 struct tcp_function_block *rblk; 510 511 rw_rlock(&tcp_function_lock); 512 rblk = tcp_func_set_ptr; 513 refcount_acquire(&rblk->tfb_refcnt); 514 rw_runlock(&tcp_function_lock); 515 return (rblk); 516 } 517 518 void 519 tcp_switch_back_to_default(struct tcpcb *tp) 520 { 521 struct tcp_function_block *tfb; 522 523 KASSERT(tp->t_fb != &tcp_def_funcblk, 524 ("%s: called by the built-in default stack", __func__)); 525 526 /* 527 * Release the old stack. This function will either find a new one 528 * or panic. 529 */ 530 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 531 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 532 refcount_release(&tp->t_fb->tfb_refcnt); 533 534 /* 535 * Now, we'll find a new function block to use. 536 * Start by trying the current user-selected 537 * default, unless this stack is the user-selected 538 * default. 539 */ 540 tfb = find_and_ref_tcp_default_fb(); 541 if (tfb == tp->t_fb) { 542 refcount_release(&tfb->tfb_refcnt); 543 tfb = NULL; 544 } 545 /* Does the stack accept this connection? */ 546 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 547 (*tfb->tfb_tcp_handoff_ok)(tp)) { 548 refcount_release(&tfb->tfb_refcnt); 549 tfb = NULL; 550 } 551 /* Try to use that stack. */ 552 if (tfb != NULL) { 553 /* Initialize the new stack. If it succeeds, we are done. */ 554 tp->t_fb = tfb; 555 if (tp->t_fb->tfb_tcp_fb_init == NULL || 556 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 557 return; 558 559 /* 560 * Initialization failed. Release the reference count on 561 * the stack. 562 */ 563 refcount_release(&tfb->tfb_refcnt); 564 } 565 566 /* 567 * If that wasn't feasible, use the built-in default 568 * stack which is not allowed to reject anyone. 569 */ 570 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 571 if (tfb == NULL) { 572 /* there always should be a default */ 573 panic("Can't refer to tcp_def_funcblk"); 574 } 575 if (tfb->tfb_tcp_handoff_ok != NULL) { 576 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 577 /* The default stack cannot say no */ 578 panic("Default stack rejects a new session?"); 579 } 580 } 581 tp->t_fb = tfb; 582 if (tp->t_fb->tfb_tcp_fb_init != NULL && 583 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 584 /* The default stack cannot fail */ 585 panic("Default stack initialization failed"); 586 } 587 } 588 589 static bool 590 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 591 const struct sockaddr *sa, void *ctx) 592 { 593 struct ip *iph; 594 #ifdef INET6 595 struct ip6_hdr *ip6; 596 #endif 597 struct udphdr *uh; 598 struct tcphdr *th; 599 int thlen; 600 uint16_t port; 601 602 TCPSTAT_INC(tcps_tunneled_pkts); 603 if ((m->m_flags & M_PKTHDR) == 0) { 604 /* Can't handle one that is not a pkt hdr */ 605 TCPSTAT_INC(tcps_tunneled_errs); 606 goto out; 607 } 608 thlen = sizeof(struct tcphdr); 609 if (m->m_len < off + sizeof(struct udphdr) + thlen && 610 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 611 TCPSTAT_INC(tcps_tunneled_errs); 612 goto out; 613 } 614 iph = mtod(m, struct ip *); 615 uh = (struct udphdr *)((caddr_t)iph + off); 616 th = (struct tcphdr *)(uh + 1); 617 thlen = th->th_off << 2; 618 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 619 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 620 if (m == NULL) { 621 TCPSTAT_INC(tcps_tunneled_errs); 622 goto out; 623 } else { 624 iph = mtod(m, struct ip *); 625 uh = (struct udphdr *)((caddr_t)iph + off); 626 th = (struct tcphdr *)(uh + 1); 627 } 628 } 629 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 630 bcopy(th, uh, m->m_len - off); 631 m->m_len -= sizeof(struct udphdr); 632 m->m_pkthdr.len -= sizeof(struct udphdr); 633 /* 634 * We use the same algorithm for 635 * both UDP and TCP for c-sum. So 636 * the code in tcp_input will skip 637 * the checksum. So we do nothing 638 * with the flag (m->m_pkthdr.csum_flags). 639 */ 640 switch (iph->ip_v) { 641 #ifdef INET 642 case IPVERSION: 643 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 644 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 645 break; 646 #endif 647 #ifdef INET6 648 case IPV6_VERSION >> 4: 649 ip6 = mtod(m, struct ip6_hdr *); 650 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 651 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 652 break; 653 #endif 654 default: 655 goto out; 656 break; 657 } 658 return (true); 659 out: 660 m_freem(m); 661 662 return (true); 663 } 664 665 static int 666 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 667 { 668 int error=ENOENT; 669 struct tcp_function_set fs; 670 struct tcp_function_block *blk; 671 672 memset(&fs, 0, sizeof(fs)); 673 rw_rlock(&tcp_function_lock); 674 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 675 if (blk) { 676 /* Found him */ 677 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 678 fs.pcbcnt = blk->tfb_refcnt; 679 } 680 rw_runlock(&tcp_function_lock); 681 error = sysctl_handle_string(oidp, fs.function_set_name, 682 sizeof(fs.function_set_name), req); 683 684 /* Check for error or no change */ 685 if (error != 0 || req->newptr == NULL) 686 return(error); 687 688 rw_wlock(&tcp_function_lock); 689 blk = find_tcp_functions_locked(&fs); 690 if ((blk == NULL) || 691 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 692 error = ENOENT; 693 goto done; 694 } 695 tcp_func_set_ptr = blk; 696 done: 697 rw_wunlock(&tcp_function_lock); 698 return (error); 699 } 700 701 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 702 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 703 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 704 "Set/get the default TCP functions"); 705 706 static int 707 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 708 { 709 int error, cnt, linesz; 710 struct tcp_function *f; 711 char *buffer, *cp; 712 size_t bufsz, outsz; 713 bool alias; 714 715 cnt = 0; 716 rw_rlock(&tcp_function_lock); 717 TAILQ_FOREACH(f, &t_functions, tf_next) { 718 cnt++; 719 } 720 rw_runlock(&tcp_function_lock); 721 722 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 723 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 724 725 error = 0; 726 cp = buffer; 727 728 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 729 "Alias", "PCB count"); 730 cp += linesz; 731 bufsz -= linesz; 732 outsz = linesz; 733 734 rw_rlock(&tcp_function_lock); 735 TAILQ_FOREACH(f, &t_functions, tf_next) { 736 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 737 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 738 f->tf_fb->tfb_tcp_block_name, 739 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 740 alias ? f->tf_name : "-", 741 f->tf_fb->tfb_refcnt); 742 if (linesz >= bufsz) { 743 error = EOVERFLOW; 744 break; 745 } 746 cp += linesz; 747 bufsz -= linesz; 748 outsz += linesz; 749 } 750 rw_runlock(&tcp_function_lock); 751 if (error == 0) 752 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 753 free(buffer, M_TEMP); 754 return (error); 755 } 756 757 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 758 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 759 NULL, 0, sysctl_net_inet_list_available, "A", 760 "list available TCP Function sets"); 761 762 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 763 764 #ifdef INET 765 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 766 #define V_udp4_tun_socket VNET(udp4_tun_socket) 767 #endif 768 #ifdef INET6 769 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 770 #define V_udp6_tun_socket VNET(udp6_tun_socket) 771 #endif 772 773 static struct sx tcpoudp_lock; 774 775 static void 776 tcp_over_udp_stop(void) 777 { 778 779 sx_assert(&tcpoudp_lock, SA_XLOCKED); 780 781 #ifdef INET 782 if (V_udp4_tun_socket != NULL) { 783 soclose(V_udp4_tun_socket); 784 V_udp4_tun_socket = NULL; 785 } 786 #endif 787 #ifdef INET6 788 if (V_udp6_tun_socket != NULL) { 789 soclose(V_udp6_tun_socket); 790 V_udp6_tun_socket = NULL; 791 } 792 #endif 793 } 794 795 static int 796 tcp_over_udp_start(void) 797 { 798 uint16_t port; 799 int ret; 800 #ifdef INET 801 struct sockaddr_in sin; 802 #endif 803 #ifdef INET6 804 struct sockaddr_in6 sin6; 805 #endif 806 807 sx_assert(&tcpoudp_lock, SA_XLOCKED); 808 809 port = V_tcp_udp_tunneling_port; 810 if (ntohs(port) == 0) { 811 /* Must have a port set */ 812 return (EINVAL); 813 } 814 #ifdef INET 815 if (V_udp4_tun_socket != NULL) { 816 /* Already running -- must stop first */ 817 return (EALREADY); 818 } 819 #endif 820 #ifdef INET6 821 if (V_udp6_tun_socket != NULL) { 822 /* Already running -- must stop first */ 823 return (EALREADY); 824 } 825 #endif 826 #ifdef INET 827 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 828 SOCK_DGRAM, IPPROTO_UDP, 829 curthread->td_ucred, curthread))) { 830 tcp_over_udp_stop(); 831 return (ret); 832 } 833 /* Call the special UDP hook. */ 834 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 835 tcp_recv_udp_tunneled_packet, 836 tcp_ctlinput_viaudp, 837 NULL))) { 838 tcp_over_udp_stop(); 839 return (ret); 840 } 841 /* Ok, we have a socket, bind it to the port. */ 842 memset(&sin, 0, sizeof(struct sockaddr_in)); 843 sin.sin_len = sizeof(struct sockaddr_in); 844 sin.sin_family = AF_INET; 845 sin.sin_port = htons(port); 846 if ((ret = sobind(V_udp4_tun_socket, 847 (struct sockaddr *)&sin, curthread))) { 848 tcp_over_udp_stop(); 849 return (ret); 850 } 851 #endif 852 #ifdef INET6 853 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 854 SOCK_DGRAM, IPPROTO_UDP, 855 curthread->td_ucred, curthread))) { 856 tcp_over_udp_stop(); 857 return (ret); 858 } 859 /* Call the special UDP hook. */ 860 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 861 tcp_recv_udp_tunneled_packet, 862 tcp6_ctlinput_viaudp, 863 NULL))) { 864 tcp_over_udp_stop(); 865 return (ret); 866 } 867 /* Ok, we have a socket, bind it to the port. */ 868 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 869 sin6.sin6_len = sizeof(struct sockaddr_in6); 870 sin6.sin6_family = AF_INET6; 871 sin6.sin6_port = htons(port); 872 if ((ret = sobind(V_udp6_tun_socket, 873 (struct sockaddr *)&sin6, curthread))) { 874 tcp_over_udp_stop(); 875 return (ret); 876 } 877 #endif 878 return (0); 879 } 880 881 static int 882 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 883 { 884 int error; 885 uint32_t old, new; 886 887 old = V_tcp_udp_tunneling_port; 888 new = old; 889 error = sysctl_handle_int(oidp, &new, 0, req); 890 if ((error == 0) && 891 (req->newptr != NULL)) { 892 if ((new < TCP_TUNNELING_PORT_MIN) || 893 (new > TCP_TUNNELING_PORT_MAX)) { 894 error = EINVAL; 895 } else { 896 sx_xlock(&tcpoudp_lock); 897 V_tcp_udp_tunneling_port = new; 898 if (old != 0) { 899 tcp_over_udp_stop(); 900 } 901 if (new != 0) { 902 error = tcp_over_udp_start(); 903 if (error != 0) { 904 V_tcp_udp_tunneling_port = 0; 905 } 906 } 907 sx_xunlock(&tcpoudp_lock); 908 } 909 } 910 return (error); 911 } 912 913 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 914 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 915 &VNET_NAME(tcp_udp_tunneling_port), 916 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 917 "Tunneling port for tcp over udp"); 918 919 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 920 921 static int 922 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 923 { 924 int error, new; 925 926 new = V_tcp_udp_tunneling_overhead; 927 error = sysctl_handle_int(oidp, &new, 0, req); 928 if (error == 0 && req->newptr) { 929 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 930 (new > TCP_TUNNELING_OVERHEAD_MAX)) 931 error = EINVAL; 932 else 933 V_tcp_udp_tunneling_overhead = new; 934 } 935 return (error); 936 } 937 938 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 939 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 940 &VNET_NAME(tcp_udp_tunneling_overhead), 941 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 942 "MSS reduction when using tcp over udp"); 943 944 /* 945 * Exports one (struct tcp_function_info) for each alias/name. 946 */ 947 static int 948 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 949 { 950 int cnt, error; 951 struct tcp_function *f; 952 struct tcp_function_info tfi; 953 954 /* 955 * We don't allow writes. 956 */ 957 if (req->newptr != NULL) 958 return (EINVAL); 959 960 /* 961 * Wire the old buffer so we can directly copy the functions to 962 * user space without dropping the lock. 963 */ 964 if (req->oldptr != NULL) { 965 error = sysctl_wire_old_buffer(req, 0); 966 if (error) 967 return (error); 968 } 969 970 /* 971 * Walk the list and copy out matching entries. If INVARIANTS 972 * is compiled in, also walk the list to verify the length of 973 * the list matches what we have recorded. 974 */ 975 rw_rlock(&tcp_function_lock); 976 977 cnt = 0; 978 #ifndef INVARIANTS 979 if (req->oldptr == NULL) { 980 cnt = tcp_fb_cnt; 981 goto skip_loop; 982 } 983 #endif 984 TAILQ_FOREACH(f, &t_functions, tf_next) { 985 #ifdef INVARIANTS 986 cnt++; 987 #endif 988 if (req->oldptr != NULL) { 989 bzero(&tfi, sizeof(tfi)); 990 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 991 tfi.tfi_id = f->tf_fb->tfb_id; 992 (void)strlcpy(tfi.tfi_alias, f->tf_name, 993 sizeof(tfi.tfi_alias)); 994 (void)strlcpy(tfi.tfi_name, 995 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 996 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 997 /* 998 * Don't stop on error, as that is the 999 * mechanism we use to accumulate length 1000 * information if the buffer was too short. 1001 */ 1002 } 1003 } 1004 KASSERT(cnt == tcp_fb_cnt, 1005 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1006 #ifndef INVARIANTS 1007 skip_loop: 1008 #endif 1009 rw_runlock(&tcp_function_lock); 1010 if (req->oldptr == NULL) 1011 error = SYSCTL_OUT(req, NULL, 1012 (cnt + 1) * sizeof(struct tcp_function_info)); 1013 1014 return (error); 1015 } 1016 1017 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1018 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1019 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1020 "List TCP function block name-to-ID mappings"); 1021 1022 /* 1023 * tfb_tcp_handoff_ok() function for the default stack. 1024 * Note that we'll basically try to take all comers. 1025 */ 1026 static int 1027 tcp_default_handoff_ok(struct tcpcb *tp) 1028 { 1029 1030 return (0); 1031 } 1032 1033 /* 1034 * tfb_tcp_fb_init() function for the default stack. 1035 * 1036 * This handles making sure we have appropriate timers set if you are 1037 * transitioning a socket that has some amount of setup done. 1038 * 1039 * The init() fuction from the default can *never* return non-zero i.e. 1040 * it is required to always succeed since it is the stack of last resort! 1041 */ 1042 static int 1043 tcp_default_fb_init(struct tcpcb *tp) 1044 { 1045 struct socket *so = tptosocket(tp); 1046 1047 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1048 1049 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1050 ("%s: connection %p in unexpected state %d", __func__, tp, 1051 tp->t_state)); 1052 1053 /* 1054 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1055 * know what to do for unexpected states (which includes TIME_WAIT). 1056 */ 1057 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1058 return (0); 1059 1060 /* 1061 * Make sure some kind of transmission timer is set if there is 1062 * outstanding data. 1063 */ 1064 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1065 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1066 tcp_timer_active(tp, TT_PERSIST))) { 1067 /* 1068 * If the session has established and it looks like it should 1069 * be in the persist state, set the persist timer. Otherwise, 1070 * set the retransmit timer. 1071 */ 1072 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1073 (int32_t)(tp->snd_nxt - tp->snd_una) < 1074 (int32_t)sbavail(&so->so_snd)) 1075 tcp_setpersist(tp); 1076 else 1077 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1078 } 1079 1080 /* All non-embryonic sessions get a keepalive timer. */ 1081 if (!tcp_timer_active(tp, TT_KEEP)) 1082 tcp_timer_activate(tp, TT_KEEP, 1083 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1084 TP_KEEPINIT(tp)); 1085 1086 /* 1087 * Make sure critical variables are initialized 1088 * if transitioning while in Recovery. 1089 */ 1090 if IN_FASTRECOVERY(tp->t_flags) { 1091 if (tp->sackhint.recover_fs == 0) 1092 tp->sackhint.recover_fs = max(1, 1093 tp->snd_nxt - tp->snd_una); 1094 } 1095 1096 return (0); 1097 } 1098 1099 /* 1100 * tfb_tcp_fb_fini() function for the default stack. 1101 * 1102 * This changes state as necessary (or prudent) to prepare for another stack 1103 * to assume responsibility for the connection. 1104 */ 1105 static void 1106 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1107 { 1108 1109 INP_WLOCK_ASSERT(tptoinpcb(tp)); 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 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1123 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1124 1125 static struct mtx isn_mtx; 1126 1127 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1128 #define ISN_LOCK() mtx_lock(&isn_mtx) 1129 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1130 1131 INPCBSTORAGE_DEFINE(tcpcbstor, tcpcb, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1132 1133 /* 1134 * Take a value and get the next power of 2 that doesn't overflow. 1135 * Used to size the tcp_inpcb hash buckets. 1136 */ 1137 static int 1138 maketcp_hashsize(int size) 1139 { 1140 int hashsize; 1141 1142 /* 1143 * auto tune. 1144 * get the next power of 2 higher than maxsockets. 1145 */ 1146 hashsize = 1 << fls(size); 1147 /* catch overflow, and just go one power of 2 smaller */ 1148 if (hashsize < size) { 1149 hashsize = 1 << (fls(size) - 1); 1150 } 1151 return (hashsize); 1152 } 1153 1154 static volatile int next_tcp_stack_id = 1; 1155 1156 /* 1157 * Register a TCP function block with the name provided in the names 1158 * array. (Note that this function does NOT automatically register 1159 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1160 * explicitly include blk->tfb_tcp_block_name in the list of names if 1161 * you wish to register the stack with that name.) 1162 * 1163 * Either all name registrations will succeed or all will fail. If 1164 * a name registration fails, the function will update the num_names 1165 * argument to point to the array index of the name that encountered 1166 * the failure. 1167 * 1168 * Returns 0 on success, or an error code on failure. 1169 */ 1170 int 1171 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1172 const char *names[], int *num_names) 1173 { 1174 struct tcp_function *n; 1175 struct tcp_function_set fs; 1176 int error, i; 1177 1178 KASSERT(names != NULL && *num_names > 0, 1179 ("%s: Called with 0-length name list", __func__)); 1180 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1181 KASSERT(rw_initialized(&tcp_function_lock), 1182 ("%s: called too early", __func__)); 1183 1184 if ((blk->tfb_tcp_output == NULL) || 1185 (blk->tfb_tcp_do_segment == NULL) || 1186 (blk->tfb_tcp_ctloutput == NULL) || 1187 (strlen(blk->tfb_tcp_block_name) == 0)) { 1188 /* 1189 * These functions are required and you 1190 * need a name. 1191 */ 1192 *num_names = 0; 1193 return (EINVAL); 1194 } 1195 1196 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1197 *num_names = 0; 1198 return (EINVAL); 1199 } 1200 1201 refcount_init(&blk->tfb_refcnt, 0); 1202 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1203 for (i = 0; i < *num_names; i++) { 1204 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1205 if (n == NULL) { 1206 error = ENOMEM; 1207 goto cleanup; 1208 } 1209 n->tf_fb = blk; 1210 1211 (void)strlcpy(fs.function_set_name, names[i], 1212 sizeof(fs.function_set_name)); 1213 rw_wlock(&tcp_function_lock); 1214 if (find_tcp_functions_locked(&fs) != NULL) { 1215 /* Duplicate name space not allowed */ 1216 rw_wunlock(&tcp_function_lock); 1217 free(n, M_TCPFUNCTIONS); 1218 error = EALREADY; 1219 goto cleanup; 1220 } 1221 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1222 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1223 tcp_fb_cnt++; 1224 rw_wunlock(&tcp_function_lock); 1225 } 1226 return(0); 1227 1228 cleanup: 1229 /* 1230 * Deregister the names we just added. Because registration failed 1231 * for names[i], we don't need to deregister that name. 1232 */ 1233 *num_names = i; 1234 rw_wlock(&tcp_function_lock); 1235 while (--i >= 0) { 1236 TAILQ_FOREACH(n, &t_functions, tf_next) { 1237 if (!strncmp(n->tf_name, names[i], 1238 TCP_FUNCTION_NAME_LEN_MAX)) { 1239 TAILQ_REMOVE(&t_functions, n, tf_next); 1240 tcp_fb_cnt--; 1241 n->tf_fb = NULL; 1242 free(n, M_TCPFUNCTIONS); 1243 break; 1244 } 1245 } 1246 } 1247 rw_wunlock(&tcp_function_lock); 1248 return (error); 1249 } 1250 1251 /* 1252 * Register a TCP function block using the name provided in the name 1253 * argument. 1254 * 1255 * Returns 0 on success, or an error code on failure. 1256 */ 1257 int 1258 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1259 int wait) 1260 { 1261 const char *name_list[1]; 1262 int num_names, rv; 1263 1264 num_names = 1; 1265 if (name != NULL) 1266 name_list[0] = name; 1267 else 1268 name_list[0] = blk->tfb_tcp_block_name; 1269 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1270 return (rv); 1271 } 1272 1273 /* 1274 * Register a TCP function block using the name defined in 1275 * blk->tfb_tcp_block_name. 1276 * 1277 * Returns 0 on success, or an error code on failure. 1278 */ 1279 int 1280 register_tcp_functions(struct tcp_function_block *blk, int wait) 1281 { 1282 1283 return (register_tcp_functions_as_name(blk, NULL, wait)); 1284 } 1285 1286 /* 1287 * Deregister all names associated with a function block. This 1288 * functionally removes the function block from use within the system. 1289 * 1290 * When called with a true quiesce argument, mark the function block 1291 * as being removed so no more stacks will use it and determine 1292 * whether the removal would succeed. 1293 * 1294 * When called with a false quiesce argument, actually attempt the 1295 * removal. 1296 * 1297 * When called with a force argument, attempt to switch all TCBs to 1298 * use the default stack instead of returning EBUSY. 1299 * 1300 * Returns 0 on success (or if the removal would succeed, or an error 1301 * code on failure. 1302 */ 1303 int 1304 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1305 bool force) 1306 { 1307 struct tcp_function *f; 1308 1309 if (blk == &tcp_def_funcblk) { 1310 /* You can't un-register the default */ 1311 return (EPERM); 1312 } 1313 rw_wlock(&tcp_function_lock); 1314 if (blk == tcp_func_set_ptr) { 1315 /* You can't free the current default */ 1316 rw_wunlock(&tcp_function_lock); 1317 return (EBUSY); 1318 } 1319 /* Mark the block so no more stacks can use it. */ 1320 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1321 /* 1322 * If TCBs are still attached to the stack, attempt to switch them 1323 * to the default stack. 1324 */ 1325 if (force && blk->tfb_refcnt) { 1326 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1327 INPLOOKUP_WLOCKPCB); 1328 struct inpcb *inp; 1329 struct tcpcb *tp; 1330 VNET_ITERATOR_DECL(vnet_iter); 1331 1332 rw_wunlock(&tcp_function_lock); 1333 1334 VNET_LIST_RLOCK(); 1335 VNET_FOREACH(vnet_iter) { 1336 CURVNET_SET(vnet_iter); 1337 while ((inp = inp_next(&inpi)) != NULL) { 1338 tp = intotcpcb(inp); 1339 if (tp == NULL || tp->t_fb != blk) 1340 continue; 1341 tcp_switch_back_to_default(tp); 1342 } 1343 CURVNET_RESTORE(); 1344 } 1345 VNET_LIST_RUNLOCK(); 1346 1347 rw_wlock(&tcp_function_lock); 1348 } 1349 if (blk->tfb_refcnt) { 1350 /* TCBs still attached. */ 1351 rw_wunlock(&tcp_function_lock); 1352 return (EBUSY); 1353 } 1354 if (quiesce) { 1355 /* Skip removal. */ 1356 rw_wunlock(&tcp_function_lock); 1357 return (0); 1358 } 1359 /* Remove any function names that map to this function block. */ 1360 while (find_tcp_fb_locked(blk, &f) != NULL) { 1361 TAILQ_REMOVE(&t_functions, f, tf_next); 1362 tcp_fb_cnt--; 1363 f->tf_fb = NULL; 1364 free(f, M_TCPFUNCTIONS); 1365 } 1366 rw_wunlock(&tcp_function_lock); 1367 return (0); 1368 } 1369 1370 static void 1371 tcp_drain(void) 1372 { 1373 struct epoch_tracker et; 1374 VNET_ITERATOR_DECL(vnet_iter); 1375 1376 if (!do_tcpdrain) 1377 return; 1378 1379 NET_EPOCH_ENTER(et); 1380 VNET_LIST_RLOCK_NOSLEEP(); 1381 VNET_FOREACH(vnet_iter) { 1382 CURVNET_SET(vnet_iter); 1383 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1384 INPLOOKUP_WLOCKPCB); 1385 struct inpcb *inpb; 1386 struct tcpcb *tcpb; 1387 1388 /* 1389 * Walk the tcpbs, if existing, and flush the reassembly queue, 1390 * if there is one... 1391 * XXX: The "Net/3" implementation doesn't imply that the TCP 1392 * reassembly queue should be flushed, but in a situation 1393 * where we're really low on mbufs, this is potentially 1394 * useful. 1395 */ 1396 while ((inpb = inp_next(&inpi)) != NULL) { 1397 if ((tcpb = intotcpcb(inpb)) != NULL) { 1398 tcp_reass_flush(tcpb); 1399 tcp_clean_sackreport(tcpb); 1400 #ifdef TCP_BLACKBOX 1401 tcp_log_drain(tcpb); 1402 #endif 1403 #ifdef TCPPCAP 1404 if (tcp_pcap_aggressive_free) { 1405 /* Free the TCP PCAP queues. */ 1406 tcp_pcap_drain(&(tcpb->t_inpkts)); 1407 tcp_pcap_drain(&(tcpb->t_outpkts)); 1408 } 1409 #endif 1410 } 1411 } 1412 CURVNET_RESTORE(); 1413 } 1414 VNET_LIST_RUNLOCK_NOSLEEP(); 1415 NET_EPOCH_EXIT(et); 1416 } 1417 1418 static void 1419 tcp_vnet_init(void *arg __unused) 1420 { 1421 1422 #ifdef TCP_HHOOK 1423 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1424 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1425 printf("%s: WARNING: unable to register helper hook\n", __func__); 1426 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1427 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1428 printf("%s: WARNING: unable to register helper hook\n", __func__); 1429 #endif 1430 #ifdef STATS 1431 if (tcp_stats_init()) 1432 printf("%s: WARNING: unable to initialise TCP stats\n", 1433 __func__); 1434 #endif 1435 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1436 tcp_tcbhashsize); 1437 1438 syncache_init(); 1439 tcp_hc_init(); 1440 1441 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1442 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1443 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1444 1445 tcp_fastopen_init(); 1446 1447 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1448 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1449 1450 V_tcp_msl = TCPTV_MSL; 1451 } 1452 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1453 tcp_vnet_init, NULL); 1454 1455 static void 1456 tcp_init(void *arg __unused) 1457 { 1458 const char *tcbhash_tuneable; 1459 int hashsize; 1460 1461 tcp_reass_global_init(); 1462 1463 /* XXX virtualize those below? */ 1464 tcp_delacktime = TCPTV_DELACK; 1465 tcp_keepinit = TCPTV_KEEP_INIT; 1466 tcp_keepidle = TCPTV_KEEP_IDLE; 1467 tcp_keepintvl = TCPTV_KEEPINTVL; 1468 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1469 tcp_rexmit_initial = TCPTV_RTOBASE; 1470 if (tcp_rexmit_initial < 1) 1471 tcp_rexmit_initial = 1; 1472 tcp_rexmit_min = TCPTV_MIN; 1473 if (tcp_rexmit_min < 1) 1474 tcp_rexmit_min = 1; 1475 tcp_persmin = TCPTV_PERSMIN; 1476 tcp_persmax = TCPTV_PERSMAX; 1477 tcp_rexmit_slop = TCPTV_CPU_VAR; 1478 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1479 1480 /* Setup the tcp function block list */ 1481 TAILQ_INIT(&t_functions); 1482 rw_init(&tcp_function_lock, "tcp_func_lock"); 1483 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1484 sx_init(&tcpoudp_lock, "TCP over UDP configuration"); 1485 #ifdef TCP_BLACKBOX 1486 /* Initialize the TCP logging data. */ 1487 tcp_log_init(); 1488 #endif 1489 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1490 1491 if (tcp_soreceive_stream) { 1492 #ifdef INET 1493 tcp_protosw.pr_soreceive = soreceive_stream; 1494 #endif 1495 #ifdef INET6 1496 tcp6_protosw.pr_soreceive = soreceive_stream; 1497 #endif /* INET6 */ 1498 } 1499 1500 #ifdef INET6 1501 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1502 #else /* INET6 */ 1503 max_protohdr_grow(sizeof(struct tcpiphdr)); 1504 #endif /* INET6 */ 1505 1506 ISN_LOCK_INIT(); 1507 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1508 SHUTDOWN_PRI_DEFAULT); 1509 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1510 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1511 1512 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1513 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1514 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1515 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1516 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1517 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1518 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1519 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1520 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1521 #ifdef TCPPCAP 1522 tcp_pcap_init(); 1523 #endif 1524 1525 hashsize = TCBHASHSIZE; 1526 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1527 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1528 if (hashsize == 0) { 1529 /* 1530 * Auto tune the hash size based on maxsockets. 1531 * A perfect hash would have a 1:1 mapping 1532 * (hashsize = maxsockets) however it's been 1533 * suggested that O(2) average is better. 1534 */ 1535 hashsize = maketcp_hashsize(maxsockets / 4); 1536 /* 1537 * Our historical default is 512, 1538 * do not autotune lower than this. 1539 */ 1540 if (hashsize < 512) 1541 hashsize = 512; 1542 if (bootverbose) 1543 printf("%s: %s auto tuned to %d\n", __func__, 1544 tcbhash_tuneable, hashsize); 1545 } 1546 /* 1547 * We require a hashsize to be a power of two. 1548 * Previously if it was not a power of two we would just reset it 1549 * back to 512, which could be a nasty surprise if you did not notice 1550 * the error message. 1551 * Instead what we do is clip it to the closest power of two lower 1552 * than the specified hash value. 1553 */ 1554 if (!powerof2(hashsize)) { 1555 int oldhashsize = hashsize; 1556 1557 hashsize = maketcp_hashsize(hashsize); 1558 /* prevent absurdly low value */ 1559 if (hashsize < 16) 1560 hashsize = 16; 1561 printf("%s: WARNING: TCB hash size not a power of 2, " 1562 "clipped from %d to %d.\n", __func__, oldhashsize, 1563 hashsize); 1564 } 1565 tcp_tcbhashsize = hashsize; 1566 1567 #ifdef INET 1568 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1569 #endif 1570 #ifdef INET6 1571 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1572 #endif 1573 } 1574 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1575 1576 #ifdef VIMAGE 1577 static void 1578 tcp_destroy(void *unused __unused) 1579 { 1580 int n; 1581 #ifdef TCP_HHOOK 1582 int error; 1583 #endif 1584 1585 /* 1586 * All our processes are gone, all our sockets should be cleaned 1587 * up, which means, we should be past the tcp_discardcb() calls. 1588 * Sleep to let all tcpcb timers really disappear and cleanup. 1589 */ 1590 for (;;) { 1591 INP_INFO_WLOCK(&V_tcbinfo); 1592 n = V_tcbinfo.ipi_count; 1593 INP_INFO_WUNLOCK(&V_tcbinfo); 1594 if (n == 0) 1595 break; 1596 pause("tcpdes", hz / 10); 1597 } 1598 tcp_hc_destroy(); 1599 syncache_destroy(); 1600 in_pcbinfo_destroy(&V_tcbinfo); 1601 /* tcp_discardcb() clears the sack_holes up. */ 1602 uma_zdestroy(V_sack_hole_zone); 1603 1604 /* 1605 * Cannot free the zone until all tcpcbs are released as we attach 1606 * the allocations to them. 1607 */ 1608 tcp_fastopen_destroy(); 1609 1610 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1611 VNET_PCPUSTAT_FREE(tcpstat); 1612 1613 #ifdef TCP_HHOOK 1614 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1615 if (error != 0) { 1616 printf("%s: WARNING: unable to deregister helper hook " 1617 "type=%d, id=%d: error %d returned\n", __func__, 1618 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1619 } 1620 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1621 if (error != 0) { 1622 printf("%s: WARNING: unable to deregister helper hook " 1623 "type=%d, id=%d: error %d returned\n", __func__, 1624 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1625 } 1626 #endif 1627 } 1628 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1629 #endif 1630 1631 void 1632 tcp_fini(void *xtp) 1633 { 1634 1635 } 1636 1637 /* 1638 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1639 * tcp_template used to store this data in mbufs, but we now recopy it out 1640 * of the tcpcb each time to conserve mbufs. 1641 */ 1642 void 1643 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1644 { 1645 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1646 1647 INP_WLOCK_ASSERT(inp); 1648 1649 #ifdef INET6 1650 if ((inp->inp_vflag & INP_IPV6) != 0) { 1651 struct ip6_hdr *ip6; 1652 1653 ip6 = (struct ip6_hdr *)ip_ptr; 1654 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1655 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1656 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1657 (IPV6_VERSION & IPV6_VERSION_MASK); 1658 if (port == 0) 1659 ip6->ip6_nxt = IPPROTO_TCP; 1660 else 1661 ip6->ip6_nxt = IPPROTO_UDP; 1662 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1663 ip6->ip6_src = inp->in6p_laddr; 1664 ip6->ip6_dst = inp->in6p_faddr; 1665 } 1666 #endif /* INET6 */ 1667 #if defined(INET6) && defined(INET) 1668 else 1669 #endif 1670 #ifdef INET 1671 { 1672 struct ip *ip; 1673 1674 ip = (struct ip *)ip_ptr; 1675 ip->ip_v = IPVERSION; 1676 ip->ip_hl = 5; 1677 ip->ip_tos = inp->inp_ip_tos; 1678 ip->ip_len = 0; 1679 ip->ip_id = 0; 1680 ip->ip_off = 0; 1681 ip->ip_ttl = inp->inp_ip_ttl; 1682 ip->ip_sum = 0; 1683 if (port == 0) 1684 ip->ip_p = IPPROTO_TCP; 1685 else 1686 ip->ip_p = IPPROTO_UDP; 1687 ip->ip_src = inp->inp_laddr; 1688 ip->ip_dst = inp->inp_faddr; 1689 } 1690 #endif /* INET */ 1691 th->th_sport = inp->inp_lport; 1692 th->th_dport = inp->inp_fport; 1693 th->th_seq = 0; 1694 th->th_ack = 0; 1695 th->th_off = 5; 1696 tcp_set_flags(th, 0); 1697 th->th_win = 0; 1698 th->th_urp = 0; 1699 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1700 } 1701 1702 /* 1703 * Create template to be used to send tcp packets on a connection. 1704 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1705 * use for this function is in keepalives, which use tcp_respond. 1706 */ 1707 struct tcptemp * 1708 tcpip_maketemplate(struct inpcb *inp) 1709 { 1710 struct tcptemp *t; 1711 1712 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1713 if (t == NULL) 1714 return (NULL); 1715 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1716 return (t); 1717 } 1718 1719 /* 1720 * Send a single message to the TCP at address specified by 1721 * the given TCP/IP header. If m == NULL, then we make a copy 1722 * of the tcpiphdr at th and send directly to the addressed host. 1723 * This is used to force keep alive messages out using the TCP 1724 * template for a connection. If flags are given then we send 1725 * a message back to the TCP which originated the segment th, 1726 * and discard the mbuf containing it and any other attached mbufs. 1727 * 1728 * In any case the ack and sequence number of the transmitted 1729 * segment are as specified by the parameters. 1730 * 1731 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1732 */ 1733 void 1734 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1735 tcp_seq ack, tcp_seq seq, uint16_t flags) 1736 { 1737 struct tcpopt to; 1738 struct inpcb *inp; 1739 struct ip *ip; 1740 struct mbuf *optm; 1741 struct udphdr *uh = NULL; 1742 struct tcphdr *nth; 1743 struct tcp_log_buffer *lgb; 1744 u_char *optp; 1745 #ifdef INET6 1746 struct ip6_hdr *ip6; 1747 int isipv6; 1748 #endif /* INET6 */ 1749 int optlen, tlen, win, ulen; 1750 int ect = 0; 1751 bool incl_opts; 1752 uint16_t port; 1753 int output_ret; 1754 #ifdef INVARIANTS 1755 int thflags = tcp_get_flags(th); 1756 #endif 1757 1758 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1759 NET_EPOCH_ASSERT(); 1760 1761 #ifdef INET6 1762 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1763 ip6 = ipgen; 1764 #endif /* INET6 */ 1765 ip = ipgen; 1766 1767 if (tp != NULL) { 1768 inp = tptoinpcb(tp); 1769 INP_LOCK_ASSERT(inp); 1770 } else 1771 inp = NULL; 1772 1773 if (m != NULL) { 1774 #ifdef INET6 1775 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1776 port = m->m_pkthdr.tcp_tun_port; 1777 else 1778 #endif 1779 if (ip && (ip->ip_p == IPPROTO_UDP)) 1780 port = m->m_pkthdr.tcp_tun_port; 1781 else 1782 port = 0; 1783 } else 1784 port = tp->t_port; 1785 1786 incl_opts = false; 1787 win = 0; 1788 if (tp != NULL) { 1789 if (!(flags & TH_RST)) { 1790 win = sbspace(&inp->inp_socket->so_rcv); 1791 if (win > TCP_MAXWIN << tp->rcv_scale) 1792 win = TCP_MAXWIN << tp->rcv_scale; 1793 } 1794 if ((tp->t_flags & TF_NOOPT) == 0) 1795 incl_opts = true; 1796 } 1797 if (m == NULL) { 1798 m = m_gethdr(M_NOWAIT, MT_DATA); 1799 if (m == NULL) 1800 return; 1801 m->m_data += max_linkhdr; 1802 #ifdef INET6 1803 if (isipv6) { 1804 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1805 sizeof(struct ip6_hdr)); 1806 ip6 = mtod(m, struct ip6_hdr *); 1807 nth = (struct tcphdr *)(ip6 + 1); 1808 if (port) { 1809 /* Insert a UDP header */ 1810 uh = (struct udphdr *)nth; 1811 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1812 uh->uh_dport = port; 1813 nth = (struct tcphdr *)(uh + 1); 1814 } 1815 } else 1816 #endif /* INET6 */ 1817 { 1818 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1819 ip = mtod(m, struct ip *); 1820 nth = (struct tcphdr *)(ip + 1); 1821 if (port) { 1822 /* Insert a UDP header */ 1823 uh = (struct udphdr *)nth; 1824 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1825 uh->uh_dport = port; 1826 nth = (struct tcphdr *)(uh + 1); 1827 } 1828 } 1829 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1830 flags = TH_ACK; 1831 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1832 struct mbuf *n; 1833 1834 /* Can't reuse 'm', allocate a new mbuf. */ 1835 n = m_gethdr(M_NOWAIT, MT_DATA); 1836 if (n == NULL) { 1837 m_freem(m); 1838 return; 1839 } 1840 1841 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1842 m_freem(m); 1843 m_freem(n); 1844 return; 1845 } 1846 1847 n->m_data += max_linkhdr; 1848 /* m_len is set later */ 1849 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1850 #ifdef INET6 1851 if (isipv6) { 1852 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1853 sizeof(struct ip6_hdr)); 1854 ip6 = mtod(n, struct ip6_hdr *); 1855 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1856 nth = (struct tcphdr *)(ip6 + 1); 1857 if (port) { 1858 /* Insert a UDP header */ 1859 uh = (struct udphdr *)nth; 1860 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1861 uh->uh_dport = port; 1862 nth = (struct tcphdr *)(uh + 1); 1863 } 1864 } else 1865 #endif /* INET6 */ 1866 { 1867 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1868 ip = mtod(n, struct ip *); 1869 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1870 nth = (struct tcphdr *)(ip + 1); 1871 if (port) { 1872 /* Insert a UDP header */ 1873 uh = (struct udphdr *)nth; 1874 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1875 uh->uh_dport = port; 1876 nth = (struct tcphdr *)(uh + 1); 1877 } 1878 } 1879 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1880 xchg(nth->th_dport, nth->th_sport, uint16_t); 1881 th = nth; 1882 m_freem(m); 1883 m = n; 1884 } else { 1885 /* 1886 * reuse the mbuf. 1887 * XXX MRT We inherit the FIB, which is lucky. 1888 */ 1889 m_freem(m->m_next); 1890 m->m_next = NULL; 1891 m->m_data = (caddr_t)ipgen; 1892 /* m_len is set later */ 1893 #ifdef INET6 1894 if (isipv6) { 1895 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1896 nth = (struct tcphdr *)(ip6 + 1); 1897 } else 1898 #endif /* INET6 */ 1899 { 1900 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1901 nth = (struct tcphdr *)(ip + 1); 1902 } 1903 if (th != nth) { 1904 /* 1905 * this is usually a case when an extension header 1906 * exists between the IPv6 header and the 1907 * TCP header. 1908 */ 1909 nth->th_sport = th->th_sport; 1910 nth->th_dport = th->th_dport; 1911 } 1912 xchg(nth->th_dport, nth->th_sport, uint16_t); 1913 #undef xchg 1914 } 1915 tlen = 0; 1916 #ifdef INET6 1917 if (isipv6) 1918 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1919 #endif 1920 #if defined(INET) && defined(INET6) 1921 else 1922 #endif 1923 #ifdef INET 1924 tlen = sizeof (struct tcpiphdr); 1925 #endif 1926 if (port) 1927 tlen += sizeof (struct udphdr); 1928 #ifdef INVARIANTS 1929 m->m_len = 0; 1930 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1931 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1932 m, tlen, (long)M_TRAILINGSPACE(m))); 1933 #endif 1934 m->m_len = tlen; 1935 to.to_flags = 0; 1936 if (incl_opts) { 1937 ect = tcp_ecn_output_established(tp, &flags, 0, false); 1938 /* Make sure we have room. */ 1939 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1940 m->m_next = m_get(M_NOWAIT, MT_DATA); 1941 if (m->m_next) { 1942 optp = mtod(m->m_next, u_char *); 1943 optm = m->m_next; 1944 } else 1945 incl_opts = false; 1946 } else { 1947 optp = (u_char *) (nth + 1); 1948 optm = m; 1949 } 1950 } 1951 if (incl_opts) { 1952 /* Timestamps. */ 1953 if (tp->t_flags & TF_RCVD_TSTMP) { 1954 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1955 to.to_tsecr = tp->ts_recent; 1956 to.to_flags |= TOF_TS; 1957 } 1958 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1959 /* TCP-MD5 (RFC2385). */ 1960 if (tp->t_flags & TF_SIGNATURE) 1961 to.to_flags |= TOF_SIGNATURE; 1962 #endif 1963 /* Add the options. */ 1964 tlen += optlen = tcp_addoptions(&to, optp); 1965 1966 /* Update m_len in the correct mbuf. */ 1967 optm->m_len += optlen; 1968 } else 1969 optlen = 0; 1970 #ifdef INET6 1971 if (isipv6) { 1972 if (uh) { 1973 ulen = tlen - sizeof(struct ip6_hdr); 1974 uh->uh_ulen = htons(ulen); 1975 } 1976 ip6->ip6_flow = htonl(ect << 20); 1977 ip6->ip6_vfc = IPV6_VERSION; 1978 if (port) 1979 ip6->ip6_nxt = IPPROTO_UDP; 1980 else 1981 ip6->ip6_nxt = IPPROTO_TCP; 1982 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1983 } 1984 #endif 1985 #if defined(INET) && defined(INET6) 1986 else 1987 #endif 1988 #ifdef INET 1989 { 1990 if (uh) { 1991 ulen = tlen - sizeof(struct ip); 1992 uh->uh_ulen = htons(ulen); 1993 } 1994 ip->ip_tos = ect; 1995 ip->ip_len = htons(tlen); 1996 ip->ip_ttl = V_ip_defttl; 1997 if (port) { 1998 ip->ip_p = IPPROTO_UDP; 1999 } else { 2000 ip->ip_p = IPPROTO_TCP; 2001 } 2002 if (V_path_mtu_discovery) 2003 ip->ip_off |= htons(IP_DF); 2004 } 2005 #endif 2006 m->m_pkthdr.len = tlen; 2007 m->m_pkthdr.rcvif = NULL; 2008 #ifdef MAC 2009 if (inp != NULL) { 2010 /* 2011 * Packet is associated with a socket, so allow the 2012 * label of the response to reflect the socket label. 2013 */ 2014 INP_LOCK_ASSERT(inp); 2015 mac_inpcb_create_mbuf(inp, m); 2016 } else { 2017 /* 2018 * Packet is not associated with a socket, so possibly 2019 * update the label in place. 2020 */ 2021 mac_netinet_tcp_reply(m); 2022 } 2023 #endif 2024 nth->th_seq = htonl(seq); 2025 nth->th_ack = htonl(ack); 2026 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2027 tcp_set_flags(nth, flags); 2028 if (tp != NULL) 2029 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2030 else 2031 nth->th_win = htons((u_short)win); 2032 nth->th_urp = 0; 2033 2034 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2035 if (to.to_flags & TOF_SIGNATURE) { 2036 if (!TCPMD5_ENABLED() || 2037 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2038 m_freem(m); 2039 return; 2040 } 2041 } 2042 #endif 2043 2044 #ifdef INET6 2045 if (isipv6) { 2046 if (port) { 2047 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2048 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2049 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2050 nth->th_sum = 0; 2051 } else { 2052 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2053 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2054 nth->th_sum = in6_cksum_pseudo(ip6, 2055 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2056 } 2057 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 2058 } 2059 #endif /* INET6 */ 2060 #if defined(INET6) && defined(INET) 2061 else 2062 #endif 2063 #ifdef INET 2064 { 2065 if (port) { 2066 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2067 htons(ulen + IPPROTO_UDP)); 2068 m->m_pkthdr.csum_flags = CSUM_UDP; 2069 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2070 nth->th_sum = 0; 2071 } else { 2072 m->m_pkthdr.csum_flags = CSUM_TCP; 2073 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2074 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2075 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2076 } 2077 } 2078 #endif /* INET */ 2079 TCP_PROBE3(debug__output, tp, th, m); 2080 if (flags & TH_RST) 2081 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2082 lgb = NULL; 2083 if ((tp != NULL) && tcp_bblogging_on(tp)) { 2084 if (INP_WLOCKED(inp)) { 2085 union tcp_log_stackspecific log; 2086 struct timeval tv; 2087 2088 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2089 log.u_bbr.inhpts = inp->inp_in_hpts; 2090 log.u_bbr.flex8 = 4; 2091 log.u_bbr.pkts_out = tp->t_maxseg; 2092 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2093 log.u_bbr.delivered = 0; 2094 lgb = tcp_log_event(tp, nth, NULL, NULL, TCP_LOG_OUT, 2095 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2096 } else { 2097 /* 2098 * We can not log the packet, since we only own the 2099 * read lock, but a write lock is needed. The read lock 2100 * is not upgraded to a write lock, since only getting 2101 * the read lock was done intentionally to improve the 2102 * handling of SYN flooding attacks. 2103 * This happens only for pure SYN segments received in 2104 * the initial CLOSED state, or received in a more 2105 * advanced state than listen and the UDP encapsulation 2106 * port is unexpected. 2107 * The incoming SYN segments do not really belong to 2108 * the TCP connection and the handling does not change 2109 * the state of the TCP connection. Therefore, the 2110 * sending of the RST segments is not logged. Please 2111 * note that also the incoming SYN segments are not 2112 * logged. 2113 * 2114 * The following code ensures that the above description 2115 * is and stays correct. 2116 */ 2117 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2118 (tp->t_state == TCPS_CLOSED || 2119 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2120 ("%s: Logging of TCP segment with flags 0x%b and " 2121 "UDP encapsulation port %u skipped in state %s", 2122 __func__, thflags, PRINT_TH_FLAGS, 2123 ntohs(port), tcpstates[tp->t_state])); 2124 } 2125 } 2126 2127 if (flags & TH_ACK) 2128 TCPSTAT_INC(tcps_sndacks); 2129 else if (flags & (TH_SYN|TH_FIN|TH_RST)) 2130 TCPSTAT_INC(tcps_sndctrl); 2131 TCPSTAT_INC(tcps_sndtotal); 2132 2133 #ifdef INET6 2134 if (isipv6) { 2135 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2136 output_ret = ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2137 } 2138 #endif /* INET6 */ 2139 #if defined(INET) && defined(INET6) 2140 else 2141 #endif 2142 #ifdef INET 2143 { 2144 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2145 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2146 } 2147 #endif 2148 if (lgb != NULL) 2149 lgb->tlb_errno = output_ret; 2150 } 2151 2152 /* 2153 * Create a new TCP control block, making an empty reassembly queue and hooking 2154 * it to the argument protocol control block. The `inp' parameter must have 2155 * come from the zone allocator set up by tcpcbstor declaration. 2156 */ 2157 struct tcpcb * 2158 tcp_newtcpcb(struct inpcb *inp) 2159 { 2160 struct tcpcb *tp = intotcpcb(inp); 2161 #ifdef INET6 2162 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2163 #endif /* INET6 */ 2164 2165 /* 2166 * Historically allocation was done with M_ZERO. There is a lot of 2167 * code that rely on that. For now take safe approach and zero whole 2168 * tcpcb. This definitely can be optimized. 2169 */ 2170 bzero(&tp->t_start_zero, t_zero_size); 2171 2172 /* Initialise cc_var struct for this tcpcb. */ 2173 tp->t_ccv.type = IPPROTO_TCP; 2174 tp->t_ccv.ccvc.tcp = tp; 2175 rw_rlock(&tcp_function_lock); 2176 tp->t_fb = tcp_func_set_ptr; 2177 refcount_acquire(&tp->t_fb->tfb_refcnt); 2178 rw_runlock(&tcp_function_lock); 2179 /* 2180 * Use the current system default CC algorithm. 2181 */ 2182 cc_attach(tp, CC_DEFAULT_ALGO()); 2183 2184 if (CC_ALGO(tp)->cb_init != NULL) 2185 if (CC_ALGO(tp)->cb_init(&tp->t_ccv, NULL) > 0) { 2186 cc_detach(tp); 2187 if (tp->t_fb->tfb_tcp_fb_fini) 2188 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2189 refcount_release(&tp->t_fb->tfb_refcnt); 2190 return (NULL); 2191 } 2192 2193 #ifdef TCP_HHOOK 2194 if (khelp_init_osd(HELPER_CLASS_TCP, &tp->t_osd)) { 2195 if (tp->t_fb->tfb_tcp_fb_fini) 2196 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2197 refcount_release(&tp->t_fb->tfb_refcnt); 2198 return (NULL); 2199 } 2200 #endif 2201 2202 TAILQ_INIT(&tp->t_segq); 2203 tp->t_maxseg = 2204 #ifdef INET6 2205 isipv6 ? V_tcp_v6mssdflt : 2206 #endif /* INET6 */ 2207 V_tcp_mssdflt; 2208 2209 callout_init_rw(&tp->t_callout, &inp->inp_lock, CALLOUT_RETURNUNLOCKED); 2210 for (int i = 0; i < TT_N; i++) 2211 tp->t_timers[i] = SBT_MAX; 2212 2213 switch (V_tcp_do_rfc1323) { 2214 case 0: 2215 break; 2216 default: 2217 case 1: 2218 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2219 break; 2220 case 2: 2221 tp->t_flags = TF_REQ_SCALE; 2222 break; 2223 case 3: 2224 tp->t_flags = TF_REQ_TSTMP; 2225 break; 2226 } 2227 if (V_tcp_do_sack) 2228 tp->t_flags |= TF_SACK_PERMIT; 2229 TAILQ_INIT(&tp->snd_holes); 2230 2231 /* 2232 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2233 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2234 * reasonable initial retransmit time. 2235 */ 2236 tp->t_srtt = TCPTV_SRTTBASE; 2237 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2238 tp->t_rttmin = tcp_rexmit_min; 2239 tp->t_rxtcur = tcp_rexmit_initial; 2240 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2241 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2242 tp->t_rcvtime = ticks; 2243 /* 2244 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2245 * because the socket may be bound to an IPv6 wildcard address, 2246 * which may match an IPv4-mapped IPv6 address. 2247 */ 2248 inp->inp_ip_ttl = V_ip_defttl; 2249 #ifdef TCPHPTS 2250 /* 2251 * If using hpts lets drop a random number in so 2252 * not all new connections fall on the same CPU. 2253 */ 2254 inp->inp_hpts_cpu = hpts_random_cpu(inp); 2255 #endif 2256 #ifdef TCPPCAP 2257 /* 2258 * Init the TCP PCAP queues. 2259 */ 2260 tcp_pcap_tcpcb_init(tp); 2261 #endif 2262 #ifdef TCP_BLACKBOX 2263 /* Initialize the per-TCPCB log data. */ 2264 tcp_log_tcpcbinit(tp); 2265 #endif 2266 tp->t_pacing_rate = -1; 2267 if (tp->t_fb->tfb_tcp_fb_init) { 2268 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2269 refcount_release(&tp->t_fb->tfb_refcnt); 2270 return (NULL); 2271 } 2272 } 2273 #ifdef STATS 2274 if (V_tcp_perconn_stats_enable == 1) 2275 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2276 #endif 2277 if (V_tcp_do_lrd) 2278 tp->t_flags |= TF_LRD; 2279 2280 return (tp); 2281 } 2282 2283 /* 2284 * Drop a TCP connection, reporting 2285 * the specified error. If connection is synchronized, 2286 * then send a RST to peer. 2287 */ 2288 struct tcpcb * 2289 tcp_drop(struct tcpcb *tp, int errno) 2290 { 2291 struct socket *so = tptosocket(tp); 2292 2293 NET_EPOCH_ASSERT(); 2294 INP_WLOCK_ASSERT(tptoinpcb(tp)); 2295 2296 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2297 tcp_state_change(tp, TCPS_CLOSED); 2298 /* Don't use tcp_output() here due to possible recursion. */ 2299 (void)tcp_output_nodrop(tp); 2300 TCPSTAT_INC(tcps_drops); 2301 } else 2302 TCPSTAT_INC(tcps_conndrops); 2303 if (errno == ETIMEDOUT && tp->t_softerror) 2304 errno = tp->t_softerror; 2305 so->so_error = errno; 2306 return (tcp_close(tp)); 2307 } 2308 2309 void 2310 tcp_discardcb(struct tcpcb *tp) 2311 { 2312 struct inpcb *inp = tptoinpcb(tp); 2313 struct socket *so = tptosocket(tp); 2314 #ifdef INET6 2315 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2316 #endif 2317 2318 INP_WLOCK_ASSERT(inp); 2319 2320 tcp_timer_stop(tp); 2321 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2322 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2323 } 2324 2325 /* free the reassembly queue, if any */ 2326 tcp_reass_flush(tp); 2327 2328 #ifdef TCP_OFFLOAD 2329 /* Disconnect offload device, if any. */ 2330 if (tp->t_flags & TF_TOE) 2331 tcp_offload_detach(tp); 2332 #endif 2333 2334 tcp_free_sackholes(tp); 2335 2336 #ifdef TCPPCAP 2337 /* Free the TCP PCAP queues. */ 2338 tcp_pcap_drain(&(tp->t_inpkts)); 2339 tcp_pcap_drain(&(tp->t_outpkts)); 2340 #endif 2341 2342 /* Allow the CC algorithm to clean up after itself. */ 2343 if (CC_ALGO(tp)->cb_destroy != NULL) 2344 CC_ALGO(tp)->cb_destroy(&tp->t_ccv); 2345 CC_DATA(tp) = NULL; 2346 /* Detach from the CC algorithm */ 2347 cc_detach(tp); 2348 2349 #ifdef TCP_HHOOK 2350 khelp_destroy_osd(&tp->t_osd); 2351 #endif 2352 #ifdef STATS 2353 stats_blob_destroy(tp->t_stats); 2354 #endif 2355 2356 CC_ALGO(tp) = NULL; 2357 2358 #ifdef TCP_BLACKBOX 2359 tcp_log_tcpcbfini(tp); 2360 #endif 2361 TCPSTATES_DEC(tp->t_state); 2362 if (tp->t_fb->tfb_tcp_fb_fini) 2363 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2364 2365 /* 2366 * If we got enough samples through the srtt filter, 2367 * save the rtt and rttvar in the routing entry. 2368 * 'Enough' is arbitrarily defined as 4 rtt samples. 2369 * 4 samples is enough for the srtt filter to converge 2370 * to within enough % of the correct value; fewer samples 2371 * and we could save a bogus rtt. The danger is not high 2372 * as tcp quickly recovers from everything. 2373 * XXX: Works very well but needs some more statistics! 2374 * 2375 * XXXRRS: Updating must be after the stack fini() since 2376 * that may be converting some internal representation of 2377 * say srtt etc into the general one used by other stacks. 2378 * Lets also at least protect against the so being NULL 2379 * as RW stated below. 2380 */ 2381 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2382 struct hc_metrics_lite metrics; 2383 uint32_t ssthresh; 2384 2385 bzero(&metrics, sizeof(metrics)); 2386 /* 2387 * Update the ssthresh always when the conditions below 2388 * are satisfied. This gives us better new start value 2389 * for the congestion avoidance for new connections. 2390 * ssthresh is only set if packet loss occurred on a session. 2391 * 2392 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2393 * being torn down. Ideally this code would not use 'so'. 2394 */ 2395 ssthresh = tp->snd_ssthresh; 2396 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2397 /* 2398 * convert the limit from user data bytes to 2399 * packets then to packet data bytes. 2400 */ 2401 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2402 if (ssthresh < 2) 2403 ssthresh = 2; 2404 ssthresh *= (tp->t_maxseg + 2405 #ifdef INET6 2406 (isipv6 ? sizeof (struct ip6_hdr) + 2407 sizeof (struct tcphdr) : 2408 #endif 2409 sizeof (struct tcpiphdr) 2410 #ifdef INET6 2411 ) 2412 #endif 2413 ); 2414 } else 2415 ssthresh = 0; 2416 metrics.rmx_ssthresh = ssthresh; 2417 2418 metrics.rmx_rtt = tp->t_srtt; 2419 metrics.rmx_rttvar = tp->t_rttvar; 2420 metrics.rmx_cwnd = tp->snd_cwnd; 2421 metrics.rmx_sendpipe = 0; 2422 metrics.rmx_recvpipe = 0; 2423 2424 tcp_hc_update(&inp->inp_inc, &metrics); 2425 } 2426 2427 refcount_release(&tp->t_fb->tfb_refcnt); 2428 } 2429 2430 /* 2431 * Attempt to close a TCP control block, marking it as dropped, and freeing 2432 * the socket if we hold the only reference. 2433 */ 2434 struct tcpcb * 2435 tcp_close(struct tcpcb *tp) 2436 { 2437 struct inpcb *inp = tptoinpcb(tp); 2438 struct socket *so = tptosocket(tp); 2439 2440 INP_WLOCK_ASSERT(inp); 2441 2442 #ifdef TCP_OFFLOAD 2443 if (tp->t_state == TCPS_LISTEN) 2444 tcp_offload_listen_stop(tp); 2445 #endif 2446 /* 2447 * This releases the TFO pending counter resource for TFO listen 2448 * sockets as well as passively-created TFO sockets that transition 2449 * from SYN_RECEIVED to CLOSED. 2450 */ 2451 if (tp->t_tfo_pending) { 2452 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2453 tp->t_tfo_pending = NULL; 2454 } 2455 #ifdef TCPHPTS 2456 tcp_hpts_remove(inp); 2457 #endif 2458 in_pcbdrop(inp); 2459 TCPSTAT_INC(tcps_closed); 2460 if (tp->t_state != TCPS_CLOSED) 2461 tcp_state_change(tp, TCPS_CLOSED); 2462 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2463 soisdisconnected(so); 2464 if (inp->inp_flags & INP_SOCKREF) { 2465 inp->inp_flags &= ~INP_SOCKREF; 2466 INP_WUNLOCK(inp); 2467 sorele(so); 2468 return (NULL); 2469 } 2470 return (tp); 2471 } 2472 2473 /* 2474 * Notify a tcp user of an asynchronous error; 2475 * store error as soft error, but wake up user 2476 * (for now, won't do anything until can select for soft error). 2477 * 2478 * Do not wake up user since there currently is no mechanism for 2479 * reporting soft errors (yet - a kqueue filter may be added). 2480 */ 2481 static struct inpcb * 2482 tcp_notify(struct inpcb *inp, int error) 2483 { 2484 struct tcpcb *tp; 2485 2486 INP_WLOCK_ASSERT(inp); 2487 2488 tp = intotcpcb(inp); 2489 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2490 2491 /* 2492 * Ignore some errors if we are hooked up. 2493 * If connection hasn't completed, has retransmitted several times, 2494 * and receives a second error, give up now. This is better 2495 * than waiting a long time to establish a connection that 2496 * can never complete. 2497 */ 2498 if (tp->t_state == TCPS_ESTABLISHED && 2499 (error == EHOSTUNREACH || error == ENETUNREACH || 2500 error == EHOSTDOWN)) { 2501 if (inp->inp_route.ro_nh) { 2502 NH_FREE(inp->inp_route.ro_nh); 2503 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2504 } 2505 return (inp); 2506 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2507 tp->t_softerror) { 2508 tp = tcp_drop(tp, error); 2509 if (tp != NULL) 2510 return (inp); 2511 else 2512 return (NULL); 2513 } else { 2514 tp->t_softerror = error; 2515 return (inp); 2516 } 2517 #if 0 2518 wakeup( &so->so_timeo); 2519 sorwakeup(so); 2520 sowwakeup(so); 2521 #endif 2522 } 2523 2524 static int 2525 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2526 { 2527 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2528 INPLOOKUP_RLOCKPCB); 2529 struct xinpgen xig; 2530 struct inpcb *inp; 2531 int error; 2532 2533 if (req->newptr != NULL) 2534 return (EPERM); 2535 2536 if (req->oldptr == NULL) { 2537 int n; 2538 2539 n = V_tcbinfo.ipi_count + 2540 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2541 n += imax(n / 8, 10); 2542 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2543 return (0); 2544 } 2545 2546 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2547 return (error); 2548 2549 bzero(&xig, sizeof(xig)); 2550 xig.xig_len = sizeof xig; 2551 xig.xig_count = V_tcbinfo.ipi_count + 2552 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2553 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2554 xig.xig_sogen = so_gencnt; 2555 error = SYSCTL_OUT(req, &xig, sizeof xig); 2556 if (error) 2557 return (error); 2558 2559 error = syncache_pcblist(req); 2560 if (error) 2561 return (error); 2562 2563 while ((inp = inp_next(&inpi)) != NULL) { 2564 if (inp->inp_gencnt <= xig.xig_gen && 2565 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 2566 struct xtcpcb xt; 2567 2568 tcp_inptoxtp(inp, &xt); 2569 error = SYSCTL_OUT(req, &xt, sizeof xt); 2570 if (error) { 2571 INP_RUNLOCK(inp); 2572 break; 2573 } else 2574 continue; 2575 } 2576 } 2577 2578 if (!error) { 2579 /* 2580 * Give the user an updated idea of our state. 2581 * If the generation differs from what we told 2582 * her before, she knows that something happened 2583 * while we were processing this request, and it 2584 * might be necessary to retry. 2585 */ 2586 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2587 xig.xig_sogen = so_gencnt; 2588 xig.xig_count = V_tcbinfo.ipi_count + 2589 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2590 error = SYSCTL_OUT(req, &xig, sizeof xig); 2591 } 2592 2593 return (error); 2594 } 2595 2596 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2597 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2598 NULL, 0, tcp_pcblist, "S,xtcpcb", 2599 "List of active TCP connections"); 2600 2601 #ifdef INET 2602 static int 2603 tcp_getcred(SYSCTL_HANDLER_ARGS) 2604 { 2605 struct xucred xuc; 2606 struct sockaddr_in addrs[2]; 2607 struct epoch_tracker et; 2608 struct inpcb *inp; 2609 int error; 2610 2611 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2612 if (error) 2613 return (error); 2614 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2615 if (error) 2616 return (error); 2617 NET_EPOCH_ENTER(et); 2618 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2619 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2620 NET_EPOCH_EXIT(et); 2621 if (inp != NULL) { 2622 if (error == 0) 2623 error = cr_canseeinpcb(req->td->td_ucred, inp); 2624 if (error == 0) 2625 cru2x(inp->inp_cred, &xuc); 2626 INP_RUNLOCK(inp); 2627 } else 2628 error = ENOENT; 2629 if (error == 0) 2630 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2631 return (error); 2632 } 2633 2634 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2635 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2636 0, 0, tcp_getcred, "S,xucred", 2637 "Get the xucred of a TCP connection"); 2638 #endif /* INET */ 2639 2640 #ifdef INET6 2641 static int 2642 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2643 { 2644 struct epoch_tracker et; 2645 struct xucred xuc; 2646 struct sockaddr_in6 addrs[2]; 2647 struct inpcb *inp; 2648 int error; 2649 #ifdef INET 2650 int mapped = 0; 2651 #endif 2652 2653 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2654 if (error) 2655 return (error); 2656 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2657 if (error) 2658 return (error); 2659 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2660 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2661 return (error); 2662 } 2663 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2664 #ifdef INET 2665 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2666 mapped = 1; 2667 else 2668 #endif 2669 return (EINVAL); 2670 } 2671 2672 NET_EPOCH_ENTER(et); 2673 #ifdef INET 2674 if (mapped == 1) 2675 inp = in_pcblookup(&V_tcbinfo, 2676 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2677 addrs[1].sin6_port, 2678 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2679 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2680 else 2681 #endif 2682 inp = in6_pcblookup(&V_tcbinfo, 2683 &addrs[1].sin6_addr, addrs[1].sin6_port, 2684 &addrs[0].sin6_addr, addrs[0].sin6_port, 2685 INPLOOKUP_RLOCKPCB, NULL); 2686 NET_EPOCH_EXIT(et); 2687 if (inp != NULL) { 2688 if (error == 0) 2689 error = cr_canseeinpcb(req->td->td_ucred, inp); 2690 if (error == 0) 2691 cru2x(inp->inp_cred, &xuc); 2692 INP_RUNLOCK(inp); 2693 } else 2694 error = ENOENT; 2695 if (error == 0) 2696 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2697 return (error); 2698 } 2699 2700 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2701 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2702 0, 0, tcp6_getcred, "S,xucred", 2703 "Get the xucred of a TCP6 connection"); 2704 #endif /* INET6 */ 2705 2706 #ifdef INET 2707 /* Path MTU to try next when a fragmentation-needed message is received. */ 2708 static inline int 2709 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2710 { 2711 int mtu = ntohs(icp->icmp_nextmtu); 2712 2713 /* If no alternative MTU was proposed, try the next smaller one. */ 2714 if (!mtu) 2715 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2716 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2717 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2718 2719 return (mtu); 2720 } 2721 2722 static void 2723 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port) 2724 { 2725 struct ip *ip; 2726 struct tcphdr *th; 2727 struct inpcb *inp; 2728 struct tcpcb *tp; 2729 struct inpcb *(*notify)(struct inpcb *, int); 2730 struct in_conninfo inc; 2731 tcp_seq icmp_tcp_seq; 2732 int errno, mtu; 2733 2734 errno = icmp_errmap(icp); 2735 switch (errno) { 2736 case 0: 2737 return; 2738 case EMSGSIZE: 2739 notify = tcp_mtudisc_notify; 2740 break; 2741 case ECONNREFUSED: 2742 if (V_icmp_may_rst) 2743 notify = tcp_drop_syn_sent; 2744 else 2745 notify = tcp_notify; 2746 break; 2747 case EHOSTUNREACH: 2748 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED) 2749 notify = tcp_drop_syn_sent; 2750 else 2751 notify = tcp_notify; 2752 break; 2753 default: 2754 notify = tcp_notify; 2755 } 2756 2757 ip = &icp->icmp_ip; 2758 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2759 icmp_tcp_seq = th->th_seq; 2760 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src, 2761 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2762 if (inp != NULL) { 2763 tp = intotcpcb(inp); 2764 #ifdef TCP_OFFLOAD 2765 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2766 /* 2767 * MTU discovery for offloaded connections. Let 2768 * the TOE driver verify seq# and process it. 2769 */ 2770 mtu = tcp_next_pmtu(icp, ip); 2771 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2772 goto out; 2773 } 2774 #endif 2775 if (tp->t_port != port) 2776 goto out; 2777 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2778 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2779 if (errno == EMSGSIZE) { 2780 /* 2781 * MTU discovery: we got a needfrag and 2782 * will potentially try a lower MTU. 2783 */ 2784 mtu = tcp_next_pmtu(icp, ip); 2785 2786 /* 2787 * Only process the offered MTU if it 2788 * is smaller than the current one. 2789 */ 2790 if (mtu < tp->t_maxseg + 2791 sizeof(struct tcpiphdr)) { 2792 bzero(&inc, sizeof(inc)); 2793 inc.inc_faddr = ip->ip_dst; 2794 inc.inc_fibnum = 2795 inp->inp_inc.inc_fibnum; 2796 tcp_hc_updatemtu(&inc, mtu); 2797 inp = tcp_mtudisc(inp, mtu); 2798 } 2799 } else 2800 inp = (*notify)(inp, errno); 2801 } 2802 } else { 2803 bzero(&inc, sizeof(inc)); 2804 inc.inc_fport = th->th_dport; 2805 inc.inc_lport = th->th_sport; 2806 inc.inc_faddr = ip->ip_dst; 2807 inc.inc_laddr = ip->ip_src; 2808 syncache_unreach(&inc, icmp_tcp_seq, port); 2809 } 2810 out: 2811 if (inp != NULL) 2812 INP_WUNLOCK(inp); 2813 } 2814 2815 static void 2816 tcp_ctlinput(struct icmp *icmp) 2817 { 2818 tcp_ctlinput_with_port(icmp, htons(0)); 2819 } 2820 2821 static void 2822 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param) 2823 { 2824 /* Its a tunneled TCP over UDP icmp */ 2825 struct icmp *icmp = param.icmp; 2826 struct ip *outer_ip, *inner_ip; 2827 struct udphdr *udp; 2828 struct tcphdr *th, ttemp; 2829 int i_hlen, o_len; 2830 uint16_t port; 2831 2832 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2833 inner_ip = &icmp->icmp_ip; 2834 i_hlen = inner_ip->ip_hl << 2; 2835 o_len = ntohs(outer_ip->ip_len); 2836 if (o_len < 2837 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2838 /* Not enough data present */ 2839 return; 2840 } 2841 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2842 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2843 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2844 return; 2845 } 2846 port = udp->uh_dport; 2847 th = (struct tcphdr *)(udp + 1); 2848 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2849 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2850 /* Now adjust down the size of the outer IP header */ 2851 o_len -= sizeof(struct udphdr); 2852 outer_ip->ip_len = htons(o_len); 2853 /* Now call in to the normal handling code */ 2854 tcp_ctlinput_with_port(icmp, port); 2855 } 2856 #endif /* INET */ 2857 2858 #ifdef INET6 2859 static inline int 2860 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2861 { 2862 int mtu = ntohl(icmp6->icmp6_mtu); 2863 2864 /* 2865 * If no alternative MTU was proposed, or the proposed MTU was too 2866 * small, set to the min. 2867 */ 2868 if (mtu < IPV6_MMTU) 2869 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2870 return (mtu); 2871 } 2872 2873 static void 2874 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port) 2875 { 2876 struct in6_addr *dst; 2877 struct inpcb *(*notify)(struct inpcb *, int); 2878 struct ip6_hdr *ip6; 2879 struct mbuf *m; 2880 struct inpcb *inp; 2881 struct tcpcb *tp; 2882 struct icmp6_hdr *icmp6; 2883 struct in_conninfo inc; 2884 struct tcp_ports { 2885 uint16_t th_sport; 2886 uint16_t th_dport; 2887 } t_ports; 2888 tcp_seq icmp_tcp_seq; 2889 unsigned int mtu; 2890 unsigned int off; 2891 int errno; 2892 2893 icmp6 = ip6cp->ip6c_icmp6; 2894 m = ip6cp->ip6c_m; 2895 ip6 = ip6cp->ip6c_ip6; 2896 off = ip6cp->ip6c_off; 2897 dst = &ip6cp->ip6c_finaldst->sin6_addr; 2898 2899 errno = icmp6_errmap(icmp6); 2900 switch (errno) { 2901 case 0: 2902 return; 2903 case EMSGSIZE: 2904 notify = tcp_mtudisc_notify; 2905 break; 2906 case ECONNREFUSED: 2907 if (V_icmp_may_rst) 2908 notify = tcp_drop_syn_sent; 2909 else 2910 notify = tcp_notify; 2911 break; 2912 case EHOSTUNREACH: 2913 /* 2914 * There are only four ICMPs that may reset connection: 2915 * - administratively prohibited 2916 * - port unreachable 2917 * - time exceeded in transit 2918 * - unknown next header 2919 */ 2920 if (V_icmp_may_rst && 2921 ((icmp6->icmp6_type == ICMP6_DST_UNREACH && 2922 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN || 2923 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) || 2924 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED && 2925 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) || 2926 (icmp6->icmp6_type == ICMP6_PARAM_PROB && 2927 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER))) 2928 notify = tcp_drop_syn_sent; 2929 else 2930 notify = tcp_notify; 2931 break; 2932 default: 2933 notify = tcp_notify; 2934 } 2935 2936 /* Check if we can safely get the ports from the tcp hdr */ 2937 if (m == NULL || 2938 (m->m_pkthdr.len < 2939 (int32_t) (off + sizeof(struct tcp_ports)))) { 2940 return; 2941 } 2942 bzero(&t_ports, sizeof(struct tcp_ports)); 2943 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 2944 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 2945 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 2946 off += sizeof(struct tcp_ports); 2947 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 2948 goto out; 2949 } 2950 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 2951 if (inp != NULL) { 2952 tp = intotcpcb(inp); 2953 #ifdef TCP_OFFLOAD 2954 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2955 /* MTU discovery for offloaded connections. */ 2956 mtu = tcp6_next_pmtu(icmp6); 2957 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2958 goto out; 2959 } 2960 #endif 2961 if (tp->t_port != port) 2962 goto out; 2963 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2964 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2965 if (errno == EMSGSIZE) { 2966 /* 2967 * MTU discovery: 2968 * If we got a needfrag set the MTU 2969 * in the route to the suggested new 2970 * value (if given) and then notify. 2971 */ 2972 mtu = tcp6_next_pmtu(icmp6); 2973 2974 bzero(&inc, sizeof(inc)); 2975 inc.inc_fibnum = M_GETFIB(m); 2976 inc.inc_flags |= INC_ISIPV6; 2977 inc.inc6_faddr = *dst; 2978 if (in6_setscope(&inc.inc6_faddr, 2979 m->m_pkthdr.rcvif, NULL)) 2980 goto out; 2981 /* 2982 * Only process the offered MTU if it 2983 * is smaller than the current one. 2984 */ 2985 if (mtu < tp->t_maxseg + 2986 sizeof (struct tcphdr) + 2987 sizeof (struct ip6_hdr)) { 2988 tcp_hc_updatemtu(&inc, mtu); 2989 tcp_mtudisc(inp, mtu); 2990 ICMP6STAT_INC(icp6s_pmtuchg); 2991 } 2992 } else 2993 inp = (*notify)(inp, errno); 2994 } 2995 } else { 2996 bzero(&inc, sizeof(inc)); 2997 inc.inc_fibnum = M_GETFIB(m); 2998 inc.inc_flags |= INC_ISIPV6; 2999 inc.inc_fport = t_ports.th_dport; 3000 inc.inc_lport = t_ports.th_sport; 3001 inc.inc6_faddr = *dst; 3002 inc.inc6_laddr = ip6->ip6_src; 3003 syncache_unreach(&inc, icmp_tcp_seq, port); 3004 } 3005 out: 3006 if (inp != NULL) 3007 INP_WUNLOCK(inp); 3008 } 3009 3010 static void 3011 tcp6_ctlinput(struct ip6ctlparam *ctl) 3012 { 3013 tcp6_ctlinput_with_port(ctl, htons(0)); 3014 } 3015 3016 static void 3017 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param) 3018 { 3019 struct ip6ctlparam *ip6cp = param.ip6cp; 3020 struct mbuf *m; 3021 struct udphdr *udp; 3022 uint16_t port; 3023 3024 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3025 if (m == NULL) { 3026 return; 3027 } 3028 udp = mtod(m, struct udphdr *); 3029 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3030 return; 3031 } 3032 port = udp->uh_dport; 3033 m_adj(m, sizeof(struct udphdr)); 3034 if ((m->m_flags & M_PKTHDR) == 0) { 3035 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3036 } 3037 /* Now call in to the normal handling code */ 3038 tcp6_ctlinput_with_port(ip6cp, port); 3039 } 3040 3041 #endif /* INET6 */ 3042 3043 static uint32_t 3044 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3045 { 3046 SIPHASH_CTX ctx; 3047 uint32_t hash[2]; 3048 3049 KASSERT(len >= SIPHASH_KEY_LENGTH, 3050 ("%s: keylen %u too short ", __func__, len)); 3051 SipHash24_Init(&ctx); 3052 SipHash_SetKey(&ctx, (uint8_t *)key); 3053 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3054 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3055 switch (inc->inc_flags & INC_ISIPV6) { 3056 #ifdef INET 3057 case 0: 3058 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3059 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3060 break; 3061 #endif 3062 #ifdef INET6 3063 case INC_ISIPV6: 3064 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3065 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3066 break; 3067 #endif 3068 } 3069 SipHash_Final((uint8_t *)hash, &ctx); 3070 3071 return (hash[0] ^ hash[1]); 3072 } 3073 3074 uint32_t 3075 tcp_new_ts_offset(struct in_conninfo *inc) 3076 { 3077 struct in_conninfo inc_store, *local_inc; 3078 3079 if (!V_tcp_ts_offset_per_conn) { 3080 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3081 inc_store.inc_lport = 0; 3082 inc_store.inc_fport = 0; 3083 local_inc = &inc_store; 3084 } else { 3085 local_inc = inc; 3086 } 3087 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3088 sizeof(V_ts_offset_secret))); 3089 } 3090 3091 /* 3092 * Following is where TCP initial sequence number generation occurs. 3093 * 3094 * There are two places where we must use initial sequence numbers: 3095 * 1. In SYN-ACK packets. 3096 * 2. In SYN packets. 3097 * 3098 * All ISNs for SYN-ACK packets are generated by the syncache. See 3099 * tcp_syncache.c for details. 3100 * 3101 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3102 * depends on this property. In addition, these ISNs should be 3103 * unguessable so as to prevent connection hijacking. To satisfy 3104 * the requirements of this situation, the algorithm outlined in 3105 * RFC 1948 is used, with only small modifications. 3106 * 3107 * Implementation details: 3108 * 3109 * Time is based off the system timer, and is corrected so that it 3110 * increases by one megabyte per second. This allows for proper 3111 * recycling on high speed LANs while still leaving over an hour 3112 * before rollover. 3113 * 3114 * As reading the *exact* system time is too expensive to be done 3115 * whenever setting up a TCP connection, we increment the time 3116 * offset in two ways. First, a small random positive increment 3117 * is added to isn_offset for each connection that is set up. 3118 * Second, the function tcp_isn_tick fires once per clock tick 3119 * and increments isn_offset as necessary so that sequence numbers 3120 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3121 * random positive increments serve only to ensure that the same 3122 * exact sequence number is never sent out twice (as could otherwise 3123 * happen when a port is recycled in less than the system tick 3124 * interval.) 3125 * 3126 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3127 * between seeding of isn_secret. This is normally set to zero, 3128 * as reseeding should not be necessary. 3129 * 3130 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3131 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3132 * general, this means holding an exclusive (write) lock. 3133 */ 3134 3135 #define ISN_BYTES_PER_SECOND 1048576 3136 #define ISN_STATIC_INCREMENT 4096 3137 #define ISN_RANDOM_INCREMENT (4096 - 1) 3138 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3139 3140 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3141 VNET_DEFINE_STATIC(int, isn_last); 3142 VNET_DEFINE_STATIC(int, isn_last_reseed); 3143 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3144 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3145 3146 #define V_isn_secret VNET(isn_secret) 3147 #define V_isn_last VNET(isn_last) 3148 #define V_isn_last_reseed VNET(isn_last_reseed) 3149 #define V_isn_offset VNET(isn_offset) 3150 #define V_isn_offset_old VNET(isn_offset_old) 3151 3152 tcp_seq 3153 tcp_new_isn(struct in_conninfo *inc) 3154 { 3155 tcp_seq new_isn; 3156 u_int32_t projected_offset; 3157 3158 ISN_LOCK(); 3159 /* Seed if this is the first use, reseed if requested. */ 3160 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3161 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3162 < (u_int)ticks))) { 3163 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3164 V_isn_last_reseed = ticks; 3165 } 3166 3167 /* Compute the hash and return the ISN. */ 3168 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3169 sizeof(V_isn_secret)); 3170 V_isn_offset += ISN_STATIC_INCREMENT + 3171 (arc4random() & ISN_RANDOM_INCREMENT); 3172 if (ticks != V_isn_last) { 3173 projected_offset = V_isn_offset_old + 3174 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3175 if (SEQ_GT(projected_offset, V_isn_offset)) 3176 V_isn_offset = projected_offset; 3177 V_isn_offset_old = V_isn_offset; 3178 V_isn_last = ticks; 3179 } 3180 new_isn += V_isn_offset; 3181 ISN_UNLOCK(); 3182 return (new_isn); 3183 } 3184 3185 /* 3186 * When a specific ICMP unreachable message is received and the 3187 * connection state is SYN-SENT, drop the connection. This behavior 3188 * is controlled by the icmp_may_rst sysctl. 3189 */ 3190 static struct inpcb * 3191 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3192 { 3193 struct tcpcb *tp; 3194 3195 NET_EPOCH_ASSERT(); 3196 INP_WLOCK_ASSERT(inp); 3197 3198 tp = intotcpcb(inp); 3199 if (tp->t_state != TCPS_SYN_SENT) 3200 return (inp); 3201 3202 if (IS_FASTOPEN(tp->t_flags)) 3203 tcp_fastopen_disable_path(tp); 3204 3205 tp = tcp_drop(tp, errno); 3206 if (tp != NULL) 3207 return (inp); 3208 else 3209 return (NULL); 3210 } 3211 3212 /* 3213 * When `need fragmentation' ICMP is received, update our idea of the MSS 3214 * based on the new value. Also nudge TCP to send something, since we 3215 * know the packet we just sent was dropped. 3216 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3217 */ 3218 static struct inpcb * 3219 tcp_mtudisc_notify(struct inpcb *inp, int error) 3220 { 3221 3222 return (tcp_mtudisc(inp, -1)); 3223 } 3224 3225 static struct inpcb * 3226 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3227 { 3228 struct tcpcb *tp; 3229 struct socket *so; 3230 3231 INP_WLOCK_ASSERT(inp); 3232 3233 tp = intotcpcb(inp); 3234 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3235 3236 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3237 3238 so = inp->inp_socket; 3239 SOCKBUF_LOCK(&so->so_snd); 3240 /* If the mss is larger than the socket buffer, decrease the mss. */ 3241 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3242 tp->t_maxseg = so->so_snd.sb_hiwat; 3243 SOCKBUF_UNLOCK(&so->so_snd); 3244 3245 TCPSTAT_INC(tcps_mturesent); 3246 tp->t_rtttime = 0; 3247 tp->snd_nxt = tp->snd_una; 3248 tcp_free_sackholes(tp); 3249 tp->snd_recover = tp->snd_max; 3250 if (tp->t_flags & TF_SACK_PERMIT) 3251 EXIT_FASTRECOVERY(tp->t_flags); 3252 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3253 /* 3254 * Conceptually the snd_nxt setting 3255 * and freeing sack holes should 3256 * be done by the default stacks 3257 * own tfb_tcp_mtu_chg(). 3258 */ 3259 tp->t_fb->tfb_tcp_mtu_chg(tp); 3260 } 3261 if (tcp_output(tp) < 0) 3262 return (NULL); 3263 else 3264 return (inp); 3265 } 3266 3267 #ifdef INET 3268 /* 3269 * Look-up the routing entry to the peer of this inpcb. If no route 3270 * is found and it cannot be allocated, then return 0. This routine 3271 * is called by TCP routines that access the rmx structure and by 3272 * tcp_mss_update to get the peer/interface MTU. 3273 */ 3274 uint32_t 3275 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3276 { 3277 struct nhop_object *nh; 3278 struct ifnet *ifp; 3279 uint32_t maxmtu = 0; 3280 3281 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3282 3283 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3284 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3285 if (nh == NULL) 3286 return (0); 3287 3288 ifp = nh->nh_ifp; 3289 maxmtu = nh->nh_mtu; 3290 3291 /* Report additional interface capabilities. */ 3292 if (cap != NULL) { 3293 if (ifp->if_capenable & IFCAP_TSO4 && 3294 ifp->if_hwassist & CSUM_TSO) { 3295 cap->ifcap |= CSUM_TSO; 3296 cap->tsomax = ifp->if_hw_tsomax; 3297 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3298 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3299 } 3300 } 3301 } 3302 return (maxmtu); 3303 } 3304 #endif /* INET */ 3305 3306 #ifdef INET6 3307 uint32_t 3308 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3309 { 3310 struct nhop_object *nh; 3311 struct in6_addr dst6; 3312 uint32_t scopeid; 3313 struct ifnet *ifp; 3314 uint32_t maxmtu = 0; 3315 3316 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3317 3318 if (inc->inc_flags & INC_IPV6MINMTU) 3319 return (IPV6_MMTU); 3320 3321 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3322 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3323 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3324 if (nh == NULL) 3325 return (0); 3326 3327 ifp = nh->nh_ifp; 3328 maxmtu = nh->nh_mtu; 3329 3330 /* Report additional interface capabilities. */ 3331 if (cap != NULL) { 3332 if (ifp->if_capenable & IFCAP_TSO6 && 3333 ifp->if_hwassist & CSUM_TSO) { 3334 cap->ifcap |= CSUM_TSO; 3335 cap->tsomax = ifp->if_hw_tsomax; 3336 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3337 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3338 } 3339 } 3340 } 3341 3342 return (maxmtu); 3343 } 3344 3345 /* 3346 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3347 * 3348 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3349 * The right place to do that is ip6_setpktopt() that has just been 3350 * executed. By the way it just filled ip6po_minmtu for us. 3351 */ 3352 void 3353 tcp6_use_min_mtu(struct tcpcb *tp) 3354 { 3355 struct inpcb *inp = tptoinpcb(tp); 3356 3357 INP_WLOCK_ASSERT(inp); 3358 /* 3359 * In case of the IPV6_USE_MIN_MTU socket 3360 * option, the INC_IPV6MINMTU flag to announce 3361 * a corresponding MSS during the initial 3362 * handshake. If the TCP connection is not in 3363 * the front states, just reduce the MSS being 3364 * used. This avoids the sending of TCP 3365 * segments which will be fragmented at the 3366 * IPv6 layer. 3367 */ 3368 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3369 if ((tp->t_state >= TCPS_SYN_SENT) && 3370 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3371 struct ip6_pktopts *opt; 3372 3373 opt = inp->in6p_outputopts; 3374 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3375 tp->t_maxseg > TCP6_MSS) 3376 tp->t_maxseg = TCP6_MSS; 3377 } 3378 } 3379 #endif /* INET6 */ 3380 3381 /* 3382 * Calculate effective SMSS per RFC5681 definition for a given TCP 3383 * connection at its current state, taking into account SACK and etc. 3384 */ 3385 u_int 3386 tcp_maxseg(const struct tcpcb *tp) 3387 { 3388 u_int optlen; 3389 3390 if (tp->t_flags & TF_NOOPT) 3391 return (tp->t_maxseg); 3392 3393 /* 3394 * Here we have a simplified code from tcp_addoptions(), 3395 * without a proper loop, and having most of paddings hardcoded. 3396 * We might make mistakes with padding here in some edge cases, 3397 * but this is harmless, since result of tcp_maxseg() is used 3398 * only in cwnd and ssthresh estimations. 3399 */ 3400 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3401 if (tp->t_flags & TF_RCVD_TSTMP) 3402 optlen = TCPOLEN_TSTAMP_APPA; 3403 else 3404 optlen = 0; 3405 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3406 if (tp->t_flags & TF_SIGNATURE) 3407 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3408 #endif 3409 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3410 optlen += TCPOLEN_SACKHDR; 3411 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3412 optlen = PADTCPOLEN(optlen); 3413 } 3414 } else { 3415 if (tp->t_flags & TF_REQ_TSTMP) 3416 optlen = TCPOLEN_TSTAMP_APPA; 3417 else 3418 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3419 if (tp->t_flags & TF_REQ_SCALE) 3420 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3421 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3422 if (tp->t_flags & TF_SIGNATURE) 3423 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3424 #endif 3425 if (tp->t_flags & TF_SACK_PERMIT) 3426 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3427 } 3428 #undef PAD 3429 optlen = min(optlen, TCP_MAXOLEN); 3430 return (tp->t_maxseg - optlen); 3431 } 3432 3433 3434 u_int 3435 tcp_fixed_maxseg(const struct tcpcb *tp) 3436 { 3437 int optlen; 3438 3439 if (tp->t_flags & TF_NOOPT) 3440 return (tp->t_maxseg); 3441 3442 /* 3443 * Here we have a simplified code from tcp_addoptions(), 3444 * without a proper loop, and having most of paddings hardcoded. 3445 * We only consider fixed options that we would send every 3446 * time I.e. SACK is not considered. This is important 3447 * for cc modules to figure out what the modulo of the 3448 * cwnd should be. 3449 */ 3450 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3451 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3452 if (tp->t_flags & TF_RCVD_TSTMP) 3453 optlen = TCPOLEN_TSTAMP_APPA; 3454 else 3455 optlen = 0; 3456 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3457 if (tp->t_flags & TF_SIGNATURE) 3458 optlen += PAD(TCPOLEN_SIGNATURE); 3459 #endif 3460 } else { 3461 if (tp->t_flags & TF_REQ_TSTMP) 3462 optlen = TCPOLEN_TSTAMP_APPA; 3463 else 3464 optlen = PAD(TCPOLEN_MAXSEG); 3465 if (tp->t_flags & TF_REQ_SCALE) 3466 optlen += PAD(TCPOLEN_WINDOW); 3467 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3468 if (tp->t_flags & TF_SIGNATURE) 3469 optlen += PAD(TCPOLEN_SIGNATURE); 3470 #endif 3471 if (tp->t_flags & TF_SACK_PERMIT) 3472 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3473 } 3474 #undef PAD 3475 optlen = min(optlen, TCP_MAXOLEN); 3476 return (tp->t_maxseg - optlen); 3477 } 3478 3479 3480 3481 static int 3482 sysctl_drop(SYSCTL_HANDLER_ARGS) 3483 { 3484 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3485 struct sockaddr_storage addrs[2]; 3486 struct inpcb *inp; 3487 struct tcpcb *tp; 3488 #ifdef INET 3489 struct sockaddr_in *fin = NULL, *lin = NULL; 3490 #endif 3491 struct epoch_tracker et; 3492 #ifdef INET6 3493 struct sockaddr_in6 *fin6, *lin6; 3494 #endif 3495 int error; 3496 3497 inp = NULL; 3498 #ifdef INET6 3499 fin6 = lin6 = NULL; 3500 #endif 3501 error = 0; 3502 3503 if (req->oldptr != NULL || req->oldlen != 0) 3504 return (EINVAL); 3505 if (req->newptr == NULL) 3506 return (EPERM); 3507 if (req->newlen < sizeof(addrs)) 3508 return (ENOMEM); 3509 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3510 if (error) 3511 return (error); 3512 3513 switch (addrs[0].ss_family) { 3514 #ifdef INET6 3515 case AF_INET6: 3516 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3517 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3518 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3519 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3520 return (EINVAL); 3521 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3522 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3523 return (EINVAL); 3524 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3525 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3526 #ifdef INET 3527 fin = (struct sockaddr_in *)&addrs[0]; 3528 lin = (struct sockaddr_in *)&addrs[1]; 3529 #endif 3530 break; 3531 } 3532 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3533 if (error) 3534 return (error); 3535 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3536 if (error) 3537 return (error); 3538 break; 3539 #endif 3540 #ifdef INET 3541 case AF_INET: 3542 fin = (struct sockaddr_in *)&addrs[0]; 3543 lin = (struct sockaddr_in *)&addrs[1]; 3544 if (fin->sin_len != sizeof(struct sockaddr_in) || 3545 lin->sin_len != sizeof(struct sockaddr_in)) 3546 return (EINVAL); 3547 break; 3548 #endif 3549 default: 3550 return (EINVAL); 3551 } 3552 NET_EPOCH_ENTER(et); 3553 switch (addrs[0].ss_family) { 3554 #ifdef INET6 3555 case AF_INET6: 3556 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3557 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3558 INPLOOKUP_WLOCKPCB, NULL); 3559 break; 3560 #endif 3561 #ifdef INET 3562 case AF_INET: 3563 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3564 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3565 break; 3566 #endif 3567 } 3568 if (inp != NULL) { 3569 if (!SOLISTENING(inp->inp_socket)) { 3570 tp = intotcpcb(inp); 3571 tp = tcp_drop(tp, ECONNABORTED); 3572 if (tp != NULL) 3573 INP_WUNLOCK(inp); 3574 } else 3575 INP_WUNLOCK(inp); 3576 } else 3577 error = ESRCH; 3578 NET_EPOCH_EXIT(et); 3579 return (error); 3580 } 3581 3582 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3583 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3584 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3585 "Drop TCP connection"); 3586 3587 static int 3588 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3589 { 3590 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3591 &tcp_ctloutput_set)); 3592 } 3593 3594 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3595 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3596 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3597 "Set socket option for TCP endpoint"); 3598 3599 #ifdef KERN_TLS 3600 static int 3601 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3602 { 3603 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3604 struct sockaddr_storage addrs[2]; 3605 struct inpcb *inp; 3606 #ifdef INET 3607 struct sockaddr_in *fin = NULL, *lin = NULL; 3608 #endif 3609 struct epoch_tracker et; 3610 #ifdef INET6 3611 struct sockaddr_in6 *fin6, *lin6; 3612 #endif 3613 int error; 3614 3615 inp = NULL; 3616 #ifdef INET6 3617 fin6 = lin6 = NULL; 3618 #endif 3619 error = 0; 3620 3621 if (req->oldptr != NULL || req->oldlen != 0) 3622 return (EINVAL); 3623 if (req->newptr == NULL) 3624 return (EPERM); 3625 if (req->newlen < sizeof(addrs)) 3626 return (ENOMEM); 3627 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3628 if (error) 3629 return (error); 3630 3631 switch (addrs[0].ss_family) { 3632 #ifdef INET6 3633 case AF_INET6: 3634 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3635 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3636 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3637 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3638 return (EINVAL); 3639 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3640 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3641 return (EINVAL); 3642 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3643 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3644 #ifdef INET 3645 fin = (struct sockaddr_in *)&addrs[0]; 3646 lin = (struct sockaddr_in *)&addrs[1]; 3647 #endif 3648 break; 3649 } 3650 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3651 if (error) 3652 return (error); 3653 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3654 if (error) 3655 return (error); 3656 break; 3657 #endif 3658 #ifdef INET 3659 case AF_INET: 3660 fin = (struct sockaddr_in *)&addrs[0]; 3661 lin = (struct sockaddr_in *)&addrs[1]; 3662 if (fin->sin_len != sizeof(struct sockaddr_in) || 3663 lin->sin_len != sizeof(struct sockaddr_in)) 3664 return (EINVAL); 3665 break; 3666 #endif 3667 default: 3668 return (EINVAL); 3669 } 3670 NET_EPOCH_ENTER(et); 3671 switch (addrs[0].ss_family) { 3672 #ifdef INET6 3673 case AF_INET6: 3674 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3675 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3676 INPLOOKUP_WLOCKPCB, NULL); 3677 break; 3678 #endif 3679 #ifdef INET 3680 case AF_INET: 3681 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3682 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3683 break; 3684 #endif 3685 } 3686 NET_EPOCH_EXIT(et); 3687 if (inp != NULL) { 3688 struct socket *so; 3689 3690 so = inp->inp_socket; 3691 soref(so); 3692 error = ktls_set_tx_mode(so, 3693 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3694 INP_WUNLOCK(inp); 3695 sorele(so); 3696 } else 3697 error = ESRCH; 3698 return (error); 3699 } 3700 3701 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3702 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3703 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3704 "Switch TCP connection to SW TLS"); 3705 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3706 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3707 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3708 "Switch TCP connection to ifnet TLS"); 3709 #endif 3710 3711 /* 3712 * Generate a standardized TCP log line for use throughout the 3713 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3714 * allow use in the interrupt context. 3715 * 3716 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3717 * NB: The function may return NULL if memory allocation failed. 3718 * 3719 * Due to header inclusion and ordering limitations the struct ip 3720 * and ip6_hdr pointers have to be passed as void pointers. 3721 */ 3722 char * 3723 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3724 const void *ip6hdr) 3725 { 3726 3727 /* Is logging enabled? */ 3728 if (V_tcp_log_in_vain == 0) 3729 return (NULL); 3730 3731 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3732 } 3733 3734 char * 3735 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3736 const void *ip6hdr) 3737 { 3738 3739 /* Is logging enabled? */ 3740 if (tcp_log_debug == 0) 3741 return (NULL); 3742 3743 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3744 } 3745 3746 static char * 3747 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3748 const void *ip6hdr) 3749 { 3750 char *s, *sp; 3751 size_t size; 3752 #ifdef INET 3753 const struct ip *ip = (const struct ip *)ip4hdr; 3754 #endif 3755 #ifdef INET6 3756 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3757 #endif /* INET6 */ 3758 3759 /* 3760 * The log line looks like this: 3761 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3762 */ 3763 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3764 sizeof(PRINT_TH_FLAGS) + 1 + 3765 #ifdef INET6 3766 2 * INET6_ADDRSTRLEN; 3767 #else 3768 2 * INET_ADDRSTRLEN; 3769 #endif /* INET6 */ 3770 3771 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3772 if (s == NULL) 3773 return (NULL); 3774 3775 strcat(s, "TCP: ["); 3776 sp = s + strlen(s); 3777 3778 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3779 inet_ntoa_r(inc->inc_faddr, sp); 3780 sp = s + strlen(s); 3781 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3782 sp = s + strlen(s); 3783 inet_ntoa_r(inc->inc_laddr, sp); 3784 sp = s + strlen(s); 3785 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3786 #ifdef INET6 3787 } else if (inc) { 3788 ip6_sprintf(sp, &inc->inc6_faddr); 3789 sp = s + strlen(s); 3790 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3791 sp = s + strlen(s); 3792 ip6_sprintf(sp, &inc->inc6_laddr); 3793 sp = s + strlen(s); 3794 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3795 } else if (ip6 && th) { 3796 ip6_sprintf(sp, &ip6->ip6_src); 3797 sp = s + strlen(s); 3798 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3799 sp = s + strlen(s); 3800 ip6_sprintf(sp, &ip6->ip6_dst); 3801 sp = s + strlen(s); 3802 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3803 #endif /* INET6 */ 3804 #ifdef INET 3805 } else if (ip && th) { 3806 inet_ntoa_r(ip->ip_src, sp); 3807 sp = s + strlen(s); 3808 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3809 sp = s + strlen(s); 3810 inet_ntoa_r(ip->ip_dst, sp); 3811 sp = s + strlen(s); 3812 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3813 #endif /* INET */ 3814 } else { 3815 free(s, M_TCPLOG); 3816 return (NULL); 3817 } 3818 sp = s + strlen(s); 3819 if (th) 3820 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3821 if (*(s + size - 1) != '\0') 3822 panic("%s: string too long", __func__); 3823 return (s); 3824 } 3825 3826 /* 3827 * A subroutine which makes it easy to track TCP state changes with DTrace. 3828 * This function shouldn't be called for t_state initializations that don't 3829 * correspond to actual TCP state transitions. 3830 */ 3831 void 3832 tcp_state_change(struct tcpcb *tp, int newstate) 3833 { 3834 #if defined(KDTRACE_HOOKS) 3835 int pstate = tp->t_state; 3836 #endif 3837 3838 TCPSTATES_DEC(tp->t_state); 3839 TCPSTATES_INC(newstate); 3840 tp->t_state = newstate; 3841 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3842 } 3843 3844 /* 3845 * Create an external-format (``xtcpcb'') structure using the information in 3846 * the kernel-format tcpcb structure pointed to by tp. This is done to 3847 * reduce the spew of irrelevant information over this interface, to isolate 3848 * user code from changes in the kernel structure, and potentially to provide 3849 * information-hiding if we decide that some of this information should be 3850 * hidden from users. 3851 */ 3852 void 3853 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3854 { 3855 struct tcpcb *tp = intotcpcb(inp); 3856 sbintime_t now; 3857 3858 bzero(xt, sizeof(*xt)); 3859 xt->t_state = tp->t_state; 3860 xt->t_logstate = tcp_get_bblog_state(tp); 3861 xt->t_flags = tp->t_flags; 3862 xt->t_sndzerowin = tp->t_sndzerowin; 3863 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3864 xt->t_rcvoopack = tp->t_rcvoopack; 3865 xt->t_rcv_wnd = tp->rcv_wnd; 3866 xt->t_snd_wnd = tp->snd_wnd; 3867 xt->t_snd_cwnd = tp->snd_cwnd; 3868 xt->t_snd_ssthresh = tp->snd_ssthresh; 3869 xt->t_dsack_bytes = tp->t_dsack_bytes; 3870 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 3871 xt->t_dsack_pack = tp->t_dsack_pack; 3872 xt->t_maxseg = tp->t_maxseg; 3873 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3874 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3875 3876 now = getsbinuptime(); 3877 #define COPYTIMER(which,where) do { \ 3878 if (tp->t_timers[which] != SBT_MAX) \ 3879 xt->where = (tp->t_timers[which] - now) / SBT_1MS; \ 3880 else \ 3881 xt->where = 0; \ 3882 } while (0) 3883 COPYTIMER(TT_DELACK, tt_delack); 3884 COPYTIMER(TT_REXMT, tt_rexmt); 3885 COPYTIMER(TT_PERSIST, tt_persist); 3886 COPYTIMER(TT_KEEP, tt_keep); 3887 COPYTIMER(TT_2MSL, tt_2msl); 3888 #undef COPYTIMER 3889 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3890 3891 xt->xt_encaps_port = tp->t_port; 3892 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3893 TCP_FUNCTION_NAME_LEN_MAX); 3894 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX); 3895 #ifdef TCP_BLACKBOX 3896 (void)tcp_log_get_id(tp, xt->xt_logid); 3897 #endif 3898 3899 xt->xt_len = sizeof(struct xtcpcb); 3900 in_pcbtoxinpcb(inp, &xt->xt_inp); 3901 } 3902 3903 void 3904 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 3905 { 3906 uint32_t bit, i; 3907 3908 if ((tp == NULL) || 3909 (status > TCP_EI_STATUS_MAX_VALUE) || 3910 (status == 0)) { 3911 /* Invalid */ 3912 return; 3913 } 3914 if (status > (sizeof(uint32_t) * 8)) { 3915 /* Should this be a KASSERT? */ 3916 return; 3917 } 3918 bit = 1U << (status - 1); 3919 if (bit & tp->t_end_info_status) { 3920 /* already logged */ 3921 return; 3922 } 3923 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 3924 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 3925 tp->t_end_info_bytes[i] = status; 3926 tp->t_end_info_status |= bit; 3927 break; 3928 } 3929 } 3930 } 3931 3932 int 3933 tcp_can_enable_pacing(void) 3934 { 3935 3936 if ((tcp_pacing_limit == -1) || 3937 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 3938 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 3939 shadow_num_connections = number_of_tcp_connections_pacing; 3940 return (1); 3941 } else { 3942 return (0); 3943 } 3944 } 3945 3946 static uint8_t tcp_pacing_warning = 0; 3947 3948 void 3949 tcp_decrement_paced_conn(void) 3950 { 3951 uint32_t ret; 3952 3953 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 3954 shadow_num_connections = number_of_tcp_connections_pacing; 3955 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 3956 if (ret == 0) { 3957 if (tcp_pacing_limit != -1) { 3958 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 3959 tcp_pacing_limit = 0; 3960 } else if (tcp_pacing_warning == 0) { 3961 printf("Warning pacing count is invalid, invalid decrement\n"); 3962 tcp_pacing_warning = 1; 3963 } 3964 } 3965 } 3966 3967 #ifdef TCP_ACCOUNTING 3968 int 3969 tcp_do_ack_accounting(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t tiwin, int mss) 3970 { 3971 if (SEQ_LT(th->th_ack, tp->snd_una)) { 3972 /* Do we have a SACK? */ 3973 if (to->to_flags & TOF_SACK) { 3974 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 3975 tp->tcp_cnt_counters[ACK_SACK]++; 3976 } 3977 return (ACK_SACK); 3978 } else { 3979 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 3980 tp->tcp_cnt_counters[ACK_BEHIND]++; 3981 } 3982 return (ACK_BEHIND); 3983 } 3984 } else if (th->th_ack == tp->snd_una) { 3985 /* Do we have a SACK? */ 3986 if (to->to_flags & TOF_SACK) { 3987 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 3988 tp->tcp_cnt_counters[ACK_SACK]++; 3989 } 3990 return (ACK_SACK); 3991 } else if (tiwin != tp->snd_wnd) { 3992 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 3993 tp->tcp_cnt_counters[ACK_RWND]++; 3994 } 3995 return (ACK_RWND); 3996 } else { 3997 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 3998 tp->tcp_cnt_counters[ACK_DUPACK]++; 3999 } 4000 return (ACK_DUPACK); 4001 } 4002 } else { 4003 if (!SEQ_GT(th->th_ack, tp->snd_max)) { 4004 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4005 tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((th->th_ack - tp->snd_una) + mss - 1)/mss); 4006 } 4007 } 4008 if (to->to_flags & TOF_SACK) { 4009 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4010 tp->tcp_cnt_counters[ACK_CUMACK_SACK]++; 4011 } 4012 return (ACK_CUMACK_SACK); 4013 } else { 4014 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4015 tp->tcp_cnt_counters[ACK_CUMACK]++; 4016 } 4017 return (ACK_CUMACK); 4018 } 4019 } 4020 } 4021 #endif 4022