1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #ifdef INET6 66 #include <sys/domain.h> 67 #endif 68 #include <sys/priv.h> 69 #include <sys/proc.h> 70 #include <sys/sdt.h> 71 #include <sys/socket.h> 72 #include <sys/socketvar.h> 73 #include <sys/protosw.h> 74 #include <sys/random.h> 75 76 #include <vm/uma.h> 77 78 #include <net/route.h> 79 #include <net/route/nhop.h> 80 #include <net/if.h> 81 #include <net/if_var.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_fib.h> 86 #include <netinet/in_kdtrace.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/ip_icmp.h> 92 #include <netinet/ip_var.h> 93 #ifdef INET6 94 #include <netinet/icmp6.h> 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_fib.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet6/scope6_var.h> 100 #include <netinet6/nd6.h> 101 #endif 102 103 #include <netinet/tcp.h> 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_log_buf.h> 109 #include <netinet/tcp_syncache.h> 110 #include <netinet/tcp_hpts.h> 111 #include <netinet/cc/cc.h> 112 #ifdef INET6 113 #include <netinet6/tcp6_var.h> 114 #endif 115 #include <netinet/tcpip.h> 116 #include <netinet/tcp_fastopen.h> 117 #ifdef TCPPCAP 118 #include <netinet/tcp_pcap.h> 119 #endif 120 #ifdef TCPDEBUG 121 #include <netinet/tcp_debug.h> 122 #endif 123 #ifdef INET6 124 #include <netinet6/ip6protosw.h> 125 #endif 126 #ifdef TCP_OFFLOAD 127 #include <netinet/tcp_offload.h> 128 #endif 129 #include <netinet/udp.h> 130 #include <netinet/udp_var.h> 131 132 #include <netipsec/ipsec_support.h> 133 134 #include <machine/in_cksum.h> 135 #include <crypto/siphash/siphash.h> 136 137 #include <security/mac/mac_framework.h> 138 139 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 140 #ifdef INET6 141 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 142 #endif 143 144 #ifdef NETFLIX_EXP_DETECTION 145 /* Sack attack detection thresholds and such */ 146 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 147 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 148 "Sack Attack detection thresholds"); 149 int32_t tcp_force_detection = 0; 150 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 151 CTLFLAG_RW, 152 &tcp_force_detection, 0, 153 "Do we force detection even if the INP has it off?"); 154 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 155 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 156 CTLFLAG_RW, 157 &tcp_sack_to_ack_thresh, 700, 158 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 159 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 160 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 161 CTLFLAG_RW, 162 &tcp_sack_to_move_thresh, 600, 163 "Percentage of sack moves we must see above (10.1 percent is 101)"); 164 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 165 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 166 CTLFLAG_RW, 167 &tcp_restoral_thresh, 550, 168 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 169 int32_t tcp_sad_decay_val = 800; 170 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 171 CTLFLAG_RW, 172 &tcp_sad_decay_val, 800, 173 "The decay percentage (10.1 percent equals 101 )"); 174 int32_t tcp_map_minimum = 500; 175 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 176 CTLFLAG_RW, 177 &tcp_map_minimum, 500, 178 "Number of Map enteries before we start detection"); 179 int32_t tcp_attack_on_turns_on_logging = 0; 180 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 181 CTLFLAG_RW, 182 &tcp_attack_on_turns_on_logging, 0, 183 "When we have a positive hit on attack, do we turn on logging?"); 184 int32_t tcp_sad_pacing_interval = 2000; 185 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 186 CTLFLAG_RW, 187 &tcp_sad_pacing_interval, 2000, 188 "What is the minimum pacing interval for a classified attacker?"); 189 190 int32_t tcp_sad_low_pps = 100; 191 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 192 CTLFLAG_RW, 193 &tcp_sad_low_pps, 100, 194 "What is the input pps that below which we do not decay?"); 195 #endif 196 uint32_t tcp_ack_war_time_window = 1000; 197 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 198 CTLFLAG_RW, 199 &tcp_ack_war_time_window, 1000, 200 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 201 uint32_t tcp_ack_war_cnt = 5; 202 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 203 CTLFLAG_RW, 204 &tcp_ack_war_cnt, 5, 205 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 206 207 struct rwlock tcp_function_lock; 208 209 static int 210 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 211 { 212 int error, new; 213 214 new = V_tcp_mssdflt; 215 error = sysctl_handle_int(oidp, &new, 0, req); 216 if (error == 0 && req->newptr) { 217 if (new < TCP_MINMSS) 218 error = EINVAL; 219 else 220 V_tcp_mssdflt = new; 221 } 222 return (error); 223 } 224 225 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 227 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 228 "Default TCP Maximum Segment Size"); 229 230 #ifdef INET6 231 static int 232 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 233 { 234 int error, new; 235 236 new = V_tcp_v6mssdflt; 237 error = sysctl_handle_int(oidp, &new, 0, req); 238 if (error == 0 && req->newptr) { 239 if (new < TCP_MINMSS) 240 error = EINVAL; 241 else 242 V_tcp_v6mssdflt = new; 243 } 244 return (error); 245 } 246 247 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 248 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 249 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 250 "Default TCP Maximum Segment Size for IPv6"); 251 #endif /* INET6 */ 252 253 /* 254 * Minimum MSS we accept and use. This prevents DoS attacks where 255 * we are forced to a ridiculous low MSS like 20 and send hundreds 256 * of packets instead of one. The effect scales with the available 257 * bandwidth and quickly saturates the CPU and network interface 258 * with packet generation and sending. Set to zero to disable MINMSS 259 * checking. This setting prevents us from sending too small packets. 260 */ 261 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 263 &VNET_NAME(tcp_minmss), 0, 264 "Minimum TCP Maximum Segment Size"); 265 266 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 267 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 268 &VNET_NAME(tcp_do_rfc1323), 0, 269 "Enable rfc1323 (high performance TCP) extensions"); 270 271 /* 272 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 273 * Some stacks negotiate TS, but never send them after connection setup. Some 274 * stacks negotiate TS, but don't send them when sending keep-alive segments. 275 * These include modern widely deployed TCP stacks. 276 * Therefore tolerating violations for now... 277 */ 278 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 280 &VNET_NAME(tcp_tolerate_missing_ts), 0, 281 "Tolerate missing TCP timestamps"); 282 283 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 284 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 285 &VNET_NAME(tcp_ts_offset_per_conn), 0, 286 "Initialize TCP timestamps per connection instead of per host pair"); 287 288 /* How many connections are pacing */ 289 static volatile uint32_t number_of_tcp_connections_pacing = 0; 290 static uint32_t shadow_num_connections = 0; 291 292 static int tcp_pacing_limit = 10000; 293 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 294 &tcp_pacing_limit, 1000, 295 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 296 297 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 298 &shadow_num_connections, 0, "Number of TCP connections being paced"); 299 300 static int tcp_log_debug = 0; 301 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 302 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 303 304 static int tcp_tcbhashsize; 305 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 306 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 307 308 static int do_tcpdrain = 1; 309 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 310 "Enable tcp_drain routine for extra help when low on mbufs"); 311 312 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 313 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 314 315 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 316 #define V_icmp_may_rst VNET(icmp_may_rst) 317 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 318 &VNET_NAME(icmp_may_rst), 0, 319 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 320 321 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 322 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 323 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 324 &VNET_NAME(tcp_isn_reseed_interval), 0, 325 "Seconds between reseeding of ISN secret"); 326 327 static int tcp_soreceive_stream; 328 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 329 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 330 331 VNET_DEFINE(uma_zone_t, sack_hole_zone); 332 #define V_sack_hole_zone VNET(sack_hole_zone) 333 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 334 static int 335 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 336 { 337 int error; 338 uint32_t new; 339 340 new = V_tcp_map_entries_limit; 341 error = sysctl_handle_int(oidp, &new, 0, req); 342 if (error == 0 && req->newptr) { 343 /* only allow "0" and value > minimum */ 344 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 345 error = EINVAL; 346 else 347 V_tcp_map_entries_limit = new; 348 } 349 return (error); 350 } 351 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 352 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 353 &VNET_NAME(tcp_map_entries_limit), 0, 354 &sysctl_net_inet_tcp_map_limit_check, "IU", 355 "Total sendmap entries limit"); 356 357 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 358 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 359 &VNET_NAME(tcp_map_split_limit), 0, 360 "Total sendmap split entries limit"); 361 362 #ifdef TCP_HHOOK 363 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 364 #endif 365 366 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 367 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 368 #define V_ts_offset_secret VNET(ts_offset_secret) 369 370 static int tcp_default_fb_init(struct tcpcb *tp); 371 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 372 static int tcp_default_handoff_ok(struct tcpcb *tp); 373 static struct inpcb *tcp_notify(struct inpcb *, int); 374 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 375 static void tcp_mtudisc(struct inpcb *, int); 376 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 377 void *ip4hdr, const void *ip6hdr); 378 379 static struct tcp_function_block tcp_def_funcblk = { 380 .tfb_tcp_block_name = "freebsd", 381 .tfb_tcp_output = tcp_output, 382 .tfb_tcp_do_segment = tcp_do_segment, 383 .tfb_tcp_ctloutput = tcp_default_ctloutput, 384 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 385 .tfb_tcp_fb_init = tcp_default_fb_init, 386 .tfb_tcp_fb_fini = tcp_default_fb_fini, 387 }; 388 389 static int tcp_fb_cnt = 0; 390 struct tcp_funchead t_functions; 391 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 392 393 static struct tcp_function_block * 394 find_tcp_functions_locked(struct tcp_function_set *fs) 395 { 396 struct tcp_function *f; 397 struct tcp_function_block *blk=NULL; 398 399 TAILQ_FOREACH(f, &t_functions, tf_next) { 400 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 401 blk = f->tf_fb; 402 break; 403 } 404 } 405 return(blk); 406 } 407 408 static struct tcp_function_block * 409 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 410 { 411 struct tcp_function_block *rblk=NULL; 412 struct tcp_function *f; 413 414 TAILQ_FOREACH(f, &t_functions, tf_next) { 415 if (f->tf_fb == blk) { 416 rblk = blk; 417 if (s) { 418 *s = f; 419 } 420 break; 421 } 422 } 423 return (rblk); 424 } 425 426 struct tcp_function_block * 427 find_and_ref_tcp_functions(struct tcp_function_set *fs) 428 { 429 struct tcp_function_block *blk; 430 431 rw_rlock(&tcp_function_lock); 432 blk = find_tcp_functions_locked(fs); 433 if (blk) 434 refcount_acquire(&blk->tfb_refcnt); 435 rw_runlock(&tcp_function_lock); 436 return(blk); 437 } 438 439 struct tcp_function_block * 440 find_and_ref_tcp_fb(struct tcp_function_block *blk) 441 { 442 struct tcp_function_block *rblk; 443 444 rw_rlock(&tcp_function_lock); 445 rblk = find_tcp_fb_locked(blk, NULL); 446 if (rblk) 447 refcount_acquire(&rblk->tfb_refcnt); 448 rw_runlock(&tcp_function_lock); 449 return(rblk); 450 } 451 452 static struct tcp_function_block * 453 find_and_ref_tcp_default_fb(void) 454 { 455 struct tcp_function_block *rblk; 456 457 rw_rlock(&tcp_function_lock); 458 rblk = tcp_func_set_ptr; 459 refcount_acquire(&rblk->tfb_refcnt); 460 rw_runlock(&tcp_function_lock); 461 return (rblk); 462 } 463 464 void 465 tcp_switch_back_to_default(struct tcpcb *tp) 466 { 467 struct tcp_function_block *tfb; 468 469 KASSERT(tp->t_fb != &tcp_def_funcblk, 470 ("%s: called by the built-in default stack", __func__)); 471 472 /* 473 * Release the old stack. This function will either find a new one 474 * or panic. 475 */ 476 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 477 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 478 refcount_release(&tp->t_fb->tfb_refcnt); 479 480 /* 481 * Now, we'll find a new function block to use. 482 * Start by trying the current user-selected 483 * default, unless this stack is the user-selected 484 * default. 485 */ 486 tfb = find_and_ref_tcp_default_fb(); 487 if (tfb == tp->t_fb) { 488 refcount_release(&tfb->tfb_refcnt); 489 tfb = NULL; 490 } 491 /* Does the stack accept this connection? */ 492 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 493 (*tfb->tfb_tcp_handoff_ok)(tp)) { 494 refcount_release(&tfb->tfb_refcnt); 495 tfb = NULL; 496 } 497 /* Try to use that stack. */ 498 if (tfb != NULL) { 499 /* Initialize the new stack. If it succeeds, we are done. */ 500 tp->t_fb = tfb; 501 if (tp->t_fb->tfb_tcp_fb_init == NULL || 502 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 503 return; 504 505 /* 506 * Initialization failed. Release the reference count on 507 * the stack. 508 */ 509 refcount_release(&tfb->tfb_refcnt); 510 } 511 512 /* 513 * If that wasn't feasible, use the built-in default 514 * stack which is not allowed to reject anyone. 515 */ 516 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 517 if (tfb == NULL) { 518 /* there always should be a default */ 519 panic("Can't refer to tcp_def_funcblk"); 520 } 521 if (tfb->tfb_tcp_handoff_ok != NULL) { 522 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 523 /* The default stack cannot say no */ 524 panic("Default stack rejects a new session?"); 525 } 526 } 527 tp->t_fb = tfb; 528 if (tp->t_fb->tfb_tcp_fb_init != NULL && 529 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 530 /* The default stack cannot fail */ 531 panic("Default stack initialization failed"); 532 } 533 } 534 535 static void 536 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 537 const struct sockaddr *sa, void *ctx) 538 { 539 struct ip *iph; 540 #ifdef INET6 541 struct ip6_hdr *ip6; 542 #endif 543 struct udphdr *uh; 544 struct tcphdr *th; 545 int thlen; 546 uint16_t port; 547 548 TCPSTAT_INC(tcps_tunneled_pkts); 549 if ((m->m_flags & M_PKTHDR) == 0) { 550 /* Can't handle one that is not a pkt hdr */ 551 TCPSTAT_INC(tcps_tunneled_errs); 552 goto out; 553 } 554 thlen = sizeof(struct tcphdr); 555 if (m->m_len < off + sizeof(struct udphdr) + thlen && 556 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 557 TCPSTAT_INC(tcps_tunneled_errs); 558 goto out; 559 } 560 iph = mtod(m, struct ip *); 561 uh = (struct udphdr *)((caddr_t)iph + off); 562 th = (struct tcphdr *)(uh + 1); 563 thlen = th->th_off << 2; 564 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 565 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 566 if (m == NULL) { 567 TCPSTAT_INC(tcps_tunneled_errs); 568 goto out; 569 } else { 570 iph = mtod(m, struct ip *); 571 uh = (struct udphdr *)((caddr_t)iph + off); 572 th = (struct tcphdr *)(uh + 1); 573 } 574 } 575 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 576 bcopy(th, uh, m->m_len - off); 577 m->m_len -= sizeof(struct udphdr); 578 m->m_pkthdr.len -= sizeof(struct udphdr); 579 /* 580 * We use the same algorithm for 581 * both UDP and TCP for c-sum. So 582 * the code in tcp_input will skip 583 * the checksum. So we do nothing 584 * with the flag (m->m_pkthdr.csum_flags). 585 */ 586 switch (iph->ip_v) { 587 #ifdef INET 588 case IPVERSION: 589 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 590 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 591 break; 592 #endif 593 #ifdef INET6 594 case IPV6_VERSION >> 4: 595 ip6 = mtod(m, struct ip6_hdr *); 596 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 597 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 598 break; 599 #endif 600 default: 601 goto out; 602 break; 603 } 604 return; 605 out: 606 m_freem(m); 607 } 608 609 static int 610 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 611 { 612 int error=ENOENT; 613 struct tcp_function_set fs; 614 struct tcp_function_block *blk; 615 616 memset(&fs, 0, sizeof(fs)); 617 rw_rlock(&tcp_function_lock); 618 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 619 if (blk) { 620 /* Found him */ 621 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 622 fs.pcbcnt = blk->tfb_refcnt; 623 } 624 rw_runlock(&tcp_function_lock); 625 error = sysctl_handle_string(oidp, fs.function_set_name, 626 sizeof(fs.function_set_name), req); 627 628 /* Check for error or no change */ 629 if (error != 0 || req->newptr == NULL) 630 return(error); 631 632 rw_wlock(&tcp_function_lock); 633 blk = find_tcp_functions_locked(&fs); 634 if ((blk == NULL) || 635 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 636 error = ENOENT; 637 goto done; 638 } 639 tcp_func_set_ptr = blk; 640 done: 641 rw_wunlock(&tcp_function_lock); 642 return (error); 643 } 644 645 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 646 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 647 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 648 "Set/get the default TCP functions"); 649 650 static int 651 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 652 { 653 int error, cnt, linesz; 654 struct tcp_function *f; 655 char *buffer, *cp; 656 size_t bufsz, outsz; 657 bool alias; 658 659 cnt = 0; 660 rw_rlock(&tcp_function_lock); 661 TAILQ_FOREACH(f, &t_functions, tf_next) { 662 cnt++; 663 } 664 rw_runlock(&tcp_function_lock); 665 666 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 667 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 668 669 error = 0; 670 cp = buffer; 671 672 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 673 "Alias", "PCB count"); 674 cp += linesz; 675 bufsz -= linesz; 676 outsz = linesz; 677 678 rw_rlock(&tcp_function_lock); 679 TAILQ_FOREACH(f, &t_functions, tf_next) { 680 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 681 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 682 f->tf_fb->tfb_tcp_block_name, 683 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 684 alias ? f->tf_name : "-", 685 f->tf_fb->tfb_refcnt); 686 if (linesz >= bufsz) { 687 error = EOVERFLOW; 688 break; 689 } 690 cp += linesz; 691 bufsz -= linesz; 692 outsz += linesz; 693 } 694 rw_runlock(&tcp_function_lock); 695 if (error == 0) 696 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 697 free(buffer, M_TEMP); 698 return (error); 699 } 700 701 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 702 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 703 NULL, 0, sysctl_net_inet_list_available, "A", 704 "list available TCP Function sets"); 705 706 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 707 708 #ifdef INET 709 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 710 #define V_udp4_tun_socket VNET(udp4_tun_socket) 711 #endif 712 #ifdef INET6 713 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 714 #define V_udp6_tun_socket VNET(udp6_tun_socket) 715 #endif 716 717 static void 718 tcp_over_udp_stop(void) 719 { 720 /* 721 * This function assumes sysctl caller holds inp_rinfo_lock() 722 * for writting! 723 */ 724 #ifdef INET 725 if (V_udp4_tun_socket != NULL) { 726 soclose(V_udp4_tun_socket); 727 V_udp4_tun_socket = NULL; 728 } 729 #endif 730 #ifdef INET6 731 if (V_udp6_tun_socket != NULL) { 732 soclose(V_udp6_tun_socket); 733 V_udp6_tun_socket = NULL; 734 } 735 #endif 736 } 737 738 static int 739 tcp_over_udp_start(void) 740 { 741 uint16_t port; 742 int ret; 743 #ifdef INET 744 struct sockaddr_in sin; 745 #endif 746 #ifdef INET6 747 struct sockaddr_in6 sin6; 748 #endif 749 /* 750 * This function assumes sysctl caller holds inp_info_rlock() 751 * for writting! 752 */ 753 port = V_tcp_udp_tunneling_port; 754 if (ntohs(port) == 0) { 755 /* Must have a port set */ 756 return (EINVAL); 757 } 758 #ifdef INET 759 if (V_udp4_tun_socket != NULL) { 760 /* Already running -- must stop first */ 761 return (EALREADY); 762 } 763 #endif 764 #ifdef INET6 765 if (V_udp6_tun_socket != NULL) { 766 /* Already running -- must stop first */ 767 return (EALREADY); 768 } 769 #endif 770 #ifdef INET 771 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 772 SOCK_DGRAM, IPPROTO_UDP, 773 curthread->td_ucred, curthread))) { 774 tcp_over_udp_stop(); 775 return (ret); 776 } 777 /* Call the special UDP hook. */ 778 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 779 tcp_recv_udp_tunneled_packet, 780 tcp_ctlinput_viaudp, 781 NULL))) { 782 tcp_over_udp_stop(); 783 return (ret); 784 } 785 /* Ok, we have a socket, bind it to the port. */ 786 memset(&sin, 0, sizeof(struct sockaddr_in)); 787 sin.sin_len = sizeof(struct sockaddr_in); 788 sin.sin_family = AF_INET; 789 sin.sin_port = htons(port); 790 if ((ret = sobind(V_udp4_tun_socket, 791 (struct sockaddr *)&sin, curthread))) { 792 tcp_over_udp_stop(); 793 return (ret); 794 } 795 #endif 796 #ifdef INET6 797 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 798 SOCK_DGRAM, IPPROTO_UDP, 799 curthread->td_ucred, curthread))) { 800 tcp_over_udp_stop(); 801 return (ret); 802 } 803 /* Call the special UDP hook. */ 804 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 805 tcp_recv_udp_tunneled_packet, 806 tcp6_ctlinput_viaudp, 807 NULL))) { 808 tcp_over_udp_stop(); 809 return (ret); 810 } 811 /* Ok, we have a socket, bind it to the port. */ 812 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 813 sin6.sin6_len = sizeof(struct sockaddr_in6); 814 sin6.sin6_family = AF_INET6; 815 sin6.sin6_port = htons(port); 816 if ((ret = sobind(V_udp6_tun_socket, 817 (struct sockaddr *)&sin6, curthread))) { 818 tcp_over_udp_stop(); 819 return (ret); 820 } 821 #endif 822 return (0); 823 } 824 825 static int 826 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 827 { 828 int error; 829 uint32_t old, new; 830 831 old = V_tcp_udp_tunneling_port; 832 new = old; 833 error = sysctl_handle_int(oidp, &new, 0, req); 834 if ((error == 0) && 835 (req->newptr != NULL)) { 836 if ((new < TCP_TUNNELING_PORT_MIN) || 837 (new > TCP_TUNNELING_PORT_MAX)) { 838 error = EINVAL; 839 } else { 840 V_tcp_udp_tunneling_port = new; 841 if (old != 0) { 842 tcp_over_udp_stop(); 843 } 844 if (new != 0) { 845 error = tcp_over_udp_start(); 846 } 847 } 848 } 849 return (error); 850 } 851 852 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 853 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 854 &VNET_NAME(tcp_udp_tunneling_port), 855 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 856 "Tunneling port for tcp over udp"); 857 858 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 859 860 static int 861 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 862 { 863 int error, new; 864 865 new = V_tcp_udp_tunneling_overhead; 866 error = sysctl_handle_int(oidp, &new, 0, req); 867 if (error == 0 && req->newptr) { 868 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 869 (new > TCP_TUNNELING_OVERHEAD_MAX)) 870 error = EINVAL; 871 else 872 V_tcp_udp_tunneling_overhead = new; 873 } 874 return (error); 875 } 876 877 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 878 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 879 &VNET_NAME(tcp_udp_tunneling_overhead), 880 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 881 "MSS reduction when using tcp over udp"); 882 883 /* 884 * Exports one (struct tcp_function_info) for each alias/name. 885 */ 886 static int 887 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 888 { 889 int cnt, error; 890 struct tcp_function *f; 891 struct tcp_function_info tfi; 892 893 /* 894 * We don't allow writes. 895 */ 896 if (req->newptr != NULL) 897 return (EINVAL); 898 899 /* 900 * Wire the old buffer so we can directly copy the functions to 901 * user space without dropping the lock. 902 */ 903 if (req->oldptr != NULL) { 904 error = sysctl_wire_old_buffer(req, 0); 905 if (error) 906 return (error); 907 } 908 909 /* 910 * Walk the list and copy out matching entries. If INVARIANTS 911 * is compiled in, also walk the list to verify the length of 912 * the list matches what we have recorded. 913 */ 914 rw_rlock(&tcp_function_lock); 915 916 cnt = 0; 917 #ifndef INVARIANTS 918 if (req->oldptr == NULL) { 919 cnt = tcp_fb_cnt; 920 goto skip_loop; 921 } 922 #endif 923 TAILQ_FOREACH(f, &t_functions, tf_next) { 924 #ifdef INVARIANTS 925 cnt++; 926 #endif 927 if (req->oldptr != NULL) { 928 bzero(&tfi, sizeof(tfi)); 929 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 930 tfi.tfi_id = f->tf_fb->tfb_id; 931 (void)strlcpy(tfi.tfi_alias, f->tf_name, 932 sizeof(tfi.tfi_alias)); 933 (void)strlcpy(tfi.tfi_name, 934 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 935 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 936 /* 937 * Don't stop on error, as that is the 938 * mechanism we use to accumulate length 939 * information if the buffer was too short. 940 */ 941 } 942 } 943 KASSERT(cnt == tcp_fb_cnt, 944 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 945 #ifndef INVARIANTS 946 skip_loop: 947 #endif 948 rw_runlock(&tcp_function_lock); 949 if (req->oldptr == NULL) 950 error = SYSCTL_OUT(req, NULL, 951 (cnt + 1) * sizeof(struct tcp_function_info)); 952 953 return (error); 954 } 955 956 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 957 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 958 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 959 "List TCP function block name-to-ID mappings"); 960 961 /* 962 * tfb_tcp_handoff_ok() function for the default stack. 963 * Note that we'll basically try to take all comers. 964 */ 965 static int 966 tcp_default_handoff_ok(struct tcpcb *tp) 967 { 968 969 return (0); 970 } 971 972 /* 973 * tfb_tcp_fb_init() function for the default stack. 974 * 975 * This handles making sure we have appropriate timers set if you are 976 * transitioning a socket that has some amount of setup done. 977 * 978 * The init() fuction from the default can *never* return non-zero i.e. 979 * it is required to always succeed since it is the stack of last resort! 980 */ 981 static int 982 tcp_default_fb_init(struct tcpcb *tp) 983 { 984 985 struct socket *so; 986 987 INP_WLOCK_ASSERT(tp->t_inpcb); 988 989 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 990 ("%s: connection %p in unexpected state %d", __func__, tp, 991 tp->t_state)); 992 993 /* 994 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 995 * know what to do for unexpected states (which includes TIME_WAIT). 996 */ 997 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 998 return (0); 999 1000 /* 1001 * Make sure some kind of transmission timer is set if there is 1002 * outstanding data. 1003 */ 1004 so = tp->t_inpcb->inp_socket; 1005 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1006 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1007 tcp_timer_active(tp, TT_PERSIST))) { 1008 /* 1009 * If the session has established and it looks like it should 1010 * be in the persist state, set the persist timer. Otherwise, 1011 * set the retransmit timer. 1012 */ 1013 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1014 (int32_t)(tp->snd_nxt - tp->snd_una) < 1015 (int32_t)sbavail(&so->so_snd)) 1016 tcp_setpersist(tp); 1017 else 1018 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1019 } 1020 1021 /* All non-embryonic sessions get a keepalive timer. */ 1022 if (!tcp_timer_active(tp, TT_KEEP)) 1023 tcp_timer_activate(tp, TT_KEEP, 1024 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1025 TP_KEEPINIT(tp)); 1026 1027 /* 1028 * Make sure critical variables are initialized 1029 * if transitioning while in Recovery. 1030 */ 1031 if IN_FASTRECOVERY(tp->t_flags) { 1032 if (tp->sackhint.recover_fs == 0) 1033 tp->sackhint.recover_fs = max(1, 1034 tp->snd_nxt - tp->snd_una); 1035 } 1036 1037 return (0); 1038 } 1039 1040 /* 1041 * tfb_tcp_fb_fini() function for the default stack. 1042 * 1043 * This changes state as necessary (or prudent) to prepare for another stack 1044 * to assume responsibility for the connection. 1045 */ 1046 static void 1047 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1048 { 1049 1050 INP_WLOCK_ASSERT(tp->t_inpcb); 1051 return; 1052 } 1053 1054 /* 1055 * Target size of TCP PCB hash tables. Must be a power of two. 1056 * 1057 * Note that this can be overridden by the kernel environment 1058 * variable net.inet.tcp.tcbhashsize 1059 */ 1060 #ifndef TCBHASHSIZE 1061 #define TCBHASHSIZE 0 1062 #endif 1063 1064 /* 1065 * XXX 1066 * Callouts should be moved into struct tcp directly. They are currently 1067 * separate because the tcpcb structure is exported to userland for sysctl 1068 * parsing purposes, which do not know about callouts. 1069 */ 1070 struct tcpcb_mem { 1071 struct tcpcb tcb; 1072 struct tcp_timer tt; 1073 struct cc_var ccv; 1074 #ifdef TCP_HHOOK 1075 struct osd osd; 1076 #endif 1077 }; 1078 1079 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1080 #define V_tcpcb_zone VNET(tcpcb_zone) 1081 1082 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1083 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1084 1085 static struct mtx isn_mtx; 1086 1087 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1088 #define ISN_LOCK() mtx_lock(&isn_mtx) 1089 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1090 1091 /* 1092 * TCP initialization. 1093 */ 1094 static void 1095 tcp_zone_change(void *tag) 1096 { 1097 1098 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 1099 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1100 tcp_tw_zone_change(); 1101 } 1102 1103 static int 1104 tcp_inpcb_init(void *mem, int size, int flags) 1105 { 1106 struct inpcb *inp = mem; 1107 1108 INP_LOCK_INIT(inp, "inp", "tcpinp"); 1109 return (0); 1110 } 1111 1112 /* 1113 * Take a value and get the next power of 2 that doesn't overflow. 1114 * Used to size the tcp_inpcb hash buckets. 1115 */ 1116 static int 1117 maketcp_hashsize(int size) 1118 { 1119 int hashsize; 1120 1121 /* 1122 * auto tune. 1123 * get the next power of 2 higher than maxsockets. 1124 */ 1125 hashsize = 1 << fls(size); 1126 /* catch overflow, and just go one power of 2 smaller */ 1127 if (hashsize < size) { 1128 hashsize = 1 << (fls(size) - 1); 1129 } 1130 return (hashsize); 1131 } 1132 1133 static volatile int next_tcp_stack_id = 1; 1134 1135 /* 1136 * Register a TCP function block with the name provided in the names 1137 * array. (Note that this function does NOT automatically register 1138 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1139 * explicitly include blk->tfb_tcp_block_name in the list of names if 1140 * you wish to register the stack with that name.) 1141 * 1142 * Either all name registrations will succeed or all will fail. If 1143 * a name registration fails, the function will update the num_names 1144 * argument to point to the array index of the name that encountered 1145 * the failure. 1146 * 1147 * Returns 0 on success, or an error code on failure. 1148 */ 1149 int 1150 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1151 const char *names[], int *num_names) 1152 { 1153 struct tcp_function *n; 1154 struct tcp_function_set fs; 1155 int error, i; 1156 1157 KASSERT(names != NULL && *num_names > 0, 1158 ("%s: Called with 0-length name list", __func__)); 1159 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1160 KASSERT(rw_initialized(&tcp_function_lock), 1161 ("%s: called too early", __func__)); 1162 1163 if ((blk->tfb_tcp_output == NULL) || 1164 (blk->tfb_tcp_do_segment == NULL) || 1165 (blk->tfb_tcp_ctloutput == NULL) || 1166 (strlen(blk->tfb_tcp_block_name) == 0)) { 1167 /* 1168 * These functions are required and you 1169 * need a name. 1170 */ 1171 *num_names = 0; 1172 return (EINVAL); 1173 } 1174 if (blk->tfb_tcp_timer_stop_all || 1175 blk->tfb_tcp_timer_activate || 1176 blk->tfb_tcp_timer_active || 1177 blk->tfb_tcp_timer_stop) { 1178 /* 1179 * If you define one timer function you 1180 * must have them all. 1181 */ 1182 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1183 (blk->tfb_tcp_timer_activate == NULL) || 1184 (blk->tfb_tcp_timer_active == NULL) || 1185 (blk->tfb_tcp_timer_stop == NULL)) { 1186 *num_names = 0; 1187 return (EINVAL); 1188 } 1189 } 1190 1191 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1192 *num_names = 0; 1193 return (EINVAL); 1194 } 1195 1196 refcount_init(&blk->tfb_refcnt, 0); 1197 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1198 for (i = 0; i < *num_names; i++) { 1199 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1200 if (n == NULL) { 1201 error = ENOMEM; 1202 goto cleanup; 1203 } 1204 n->tf_fb = blk; 1205 1206 (void)strlcpy(fs.function_set_name, names[i], 1207 sizeof(fs.function_set_name)); 1208 rw_wlock(&tcp_function_lock); 1209 if (find_tcp_functions_locked(&fs) != NULL) { 1210 /* Duplicate name space not allowed */ 1211 rw_wunlock(&tcp_function_lock); 1212 free(n, M_TCPFUNCTIONS); 1213 error = EALREADY; 1214 goto cleanup; 1215 } 1216 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1217 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1218 tcp_fb_cnt++; 1219 rw_wunlock(&tcp_function_lock); 1220 } 1221 return(0); 1222 1223 cleanup: 1224 /* 1225 * Deregister the names we just added. Because registration failed 1226 * for names[i], we don't need to deregister that name. 1227 */ 1228 *num_names = i; 1229 rw_wlock(&tcp_function_lock); 1230 while (--i >= 0) { 1231 TAILQ_FOREACH(n, &t_functions, tf_next) { 1232 if (!strncmp(n->tf_name, names[i], 1233 TCP_FUNCTION_NAME_LEN_MAX)) { 1234 TAILQ_REMOVE(&t_functions, n, tf_next); 1235 tcp_fb_cnt--; 1236 n->tf_fb = NULL; 1237 free(n, M_TCPFUNCTIONS); 1238 break; 1239 } 1240 } 1241 } 1242 rw_wunlock(&tcp_function_lock); 1243 return (error); 1244 } 1245 1246 /* 1247 * Register a TCP function block using the name provided in the name 1248 * argument. 1249 * 1250 * Returns 0 on success, or an error code on failure. 1251 */ 1252 int 1253 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1254 int wait) 1255 { 1256 const char *name_list[1]; 1257 int num_names, rv; 1258 1259 num_names = 1; 1260 if (name != NULL) 1261 name_list[0] = name; 1262 else 1263 name_list[0] = blk->tfb_tcp_block_name; 1264 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1265 return (rv); 1266 } 1267 1268 /* 1269 * Register a TCP function block using the name defined in 1270 * blk->tfb_tcp_block_name. 1271 * 1272 * Returns 0 on success, or an error code on failure. 1273 */ 1274 int 1275 register_tcp_functions(struct tcp_function_block *blk, int wait) 1276 { 1277 1278 return (register_tcp_functions_as_name(blk, NULL, wait)); 1279 } 1280 1281 /* 1282 * Deregister all names associated with a function block. This 1283 * functionally removes the function block from use within the system. 1284 * 1285 * When called with a true quiesce argument, mark the function block 1286 * as being removed so no more stacks will use it and determine 1287 * whether the removal would succeed. 1288 * 1289 * When called with a false quiesce argument, actually attempt the 1290 * removal. 1291 * 1292 * When called with a force argument, attempt to switch all TCBs to 1293 * use the default stack instead of returning EBUSY. 1294 * 1295 * Returns 0 on success (or if the removal would succeed, or an error 1296 * code on failure. 1297 */ 1298 int 1299 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1300 bool force) 1301 { 1302 struct tcp_function *f; 1303 1304 if (blk == &tcp_def_funcblk) { 1305 /* You can't un-register the default */ 1306 return (EPERM); 1307 } 1308 rw_wlock(&tcp_function_lock); 1309 if (blk == tcp_func_set_ptr) { 1310 /* You can't free the current default */ 1311 rw_wunlock(&tcp_function_lock); 1312 return (EBUSY); 1313 } 1314 /* Mark the block so no more stacks can use it. */ 1315 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1316 /* 1317 * If TCBs are still attached to the stack, attempt to switch them 1318 * to the default stack. 1319 */ 1320 if (force && blk->tfb_refcnt) { 1321 struct inpcb *inp; 1322 struct tcpcb *tp; 1323 VNET_ITERATOR_DECL(vnet_iter); 1324 1325 rw_wunlock(&tcp_function_lock); 1326 1327 VNET_LIST_RLOCK(); 1328 VNET_FOREACH(vnet_iter) { 1329 CURVNET_SET(vnet_iter); 1330 INP_INFO_WLOCK(&V_tcbinfo); 1331 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1332 INP_WLOCK(inp); 1333 if (inp->inp_flags & INP_TIMEWAIT) { 1334 INP_WUNLOCK(inp); 1335 continue; 1336 } 1337 tp = intotcpcb(inp); 1338 if (tp == NULL || tp->t_fb != blk) { 1339 INP_WUNLOCK(inp); 1340 continue; 1341 } 1342 tcp_switch_back_to_default(tp); 1343 INP_WUNLOCK(inp); 1344 } 1345 INP_INFO_WUNLOCK(&V_tcbinfo); 1346 CURVNET_RESTORE(); 1347 } 1348 VNET_LIST_RUNLOCK(); 1349 1350 rw_wlock(&tcp_function_lock); 1351 } 1352 if (blk->tfb_refcnt) { 1353 /* TCBs still attached. */ 1354 rw_wunlock(&tcp_function_lock); 1355 return (EBUSY); 1356 } 1357 if (quiesce) { 1358 /* Skip removal. */ 1359 rw_wunlock(&tcp_function_lock); 1360 return (0); 1361 } 1362 /* Remove any function names that map to this function block. */ 1363 while (find_tcp_fb_locked(blk, &f) != NULL) { 1364 TAILQ_REMOVE(&t_functions, f, tf_next); 1365 tcp_fb_cnt--; 1366 f->tf_fb = NULL; 1367 free(f, M_TCPFUNCTIONS); 1368 } 1369 rw_wunlock(&tcp_function_lock); 1370 return (0); 1371 } 1372 1373 void 1374 tcp_init(void) 1375 { 1376 const char *tcbhash_tuneable; 1377 int hashsize; 1378 1379 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1380 1381 #ifdef TCP_HHOOK 1382 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1383 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1384 printf("%s: WARNING: unable to register helper hook\n", __func__); 1385 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1386 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1387 printf("%s: WARNING: unable to register helper hook\n", __func__); 1388 #endif 1389 #ifdef STATS 1390 if (tcp_stats_init()) 1391 printf("%s: WARNING: unable to initialise TCP stats\n", 1392 __func__); 1393 #endif 1394 hashsize = TCBHASHSIZE; 1395 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1396 if (hashsize == 0) { 1397 /* 1398 * Auto tune the hash size based on maxsockets. 1399 * A perfect hash would have a 1:1 mapping 1400 * (hashsize = maxsockets) however it's been 1401 * suggested that O(2) average is better. 1402 */ 1403 hashsize = maketcp_hashsize(maxsockets / 4); 1404 /* 1405 * Our historical default is 512, 1406 * do not autotune lower than this. 1407 */ 1408 if (hashsize < 512) 1409 hashsize = 512; 1410 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1411 printf("%s: %s auto tuned to %d\n", __func__, 1412 tcbhash_tuneable, hashsize); 1413 } 1414 /* 1415 * We require a hashsize to be a power of two. 1416 * Previously if it was not a power of two we would just reset it 1417 * back to 512, which could be a nasty surprise if you did not notice 1418 * the error message. 1419 * Instead what we do is clip it to the closest power of two lower 1420 * than the specified hash value. 1421 */ 1422 if (!powerof2(hashsize)) { 1423 int oldhashsize = hashsize; 1424 1425 hashsize = maketcp_hashsize(hashsize); 1426 /* prevent absurdly low value */ 1427 if (hashsize < 16) 1428 hashsize = 16; 1429 printf("%s: WARNING: TCB hash size not a power of 2, " 1430 "clipped from %d to %d.\n", __func__, oldhashsize, 1431 hashsize); 1432 } 1433 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1434 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1435 1436 /* 1437 * These have to be type stable for the benefit of the timers. 1438 */ 1439 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1440 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1441 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1442 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1443 1444 tcp_tw_init(); 1445 syncache_init(); 1446 tcp_hc_init(); 1447 1448 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1449 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1450 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1451 1452 tcp_fastopen_init(); 1453 1454 /* Skip initialization of globals for non-default instances. */ 1455 if (!IS_DEFAULT_VNET(curvnet)) 1456 return; 1457 1458 tcp_reass_global_init(); 1459 1460 /* XXX virtualize those bellow? */ 1461 tcp_delacktime = TCPTV_DELACK; 1462 tcp_keepinit = TCPTV_KEEP_INIT; 1463 tcp_keepidle = TCPTV_KEEP_IDLE; 1464 tcp_keepintvl = TCPTV_KEEPINTVL; 1465 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1466 tcp_msl = TCPTV_MSL; 1467 tcp_rexmit_initial = TCPTV_RTOBASE; 1468 if (tcp_rexmit_initial < 1) 1469 tcp_rexmit_initial = 1; 1470 tcp_rexmit_min = TCPTV_MIN; 1471 if (tcp_rexmit_min < 1) 1472 tcp_rexmit_min = 1; 1473 tcp_persmin = TCPTV_PERSMIN; 1474 tcp_persmax = TCPTV_PERSMAX; 1475 tcp_rexmit_slop = TCPTV_CPU_VAR; 1476 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1477 tcp_tcbhashsize = hashsize; 1478 1479 /* Setup the tcp function block list */ 1480 TAILQ_INIT(&t_functions); 1481 rw_init(&tcp_function_lock, "tcp_func_lock"); 1482 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1483 #ifdef TCP_BLACKBOX 1484 /* Initialize the TCP logging data. */ 1485 tcp_log_init(); 1486 #endif 1487 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1488 1489 if (tcp_soreceive_stream) { 1490 #ifdef INET 1491 tcp_usrreqs.pru_soreceive = soreceive_stream; 1492 #endif 1493 #ifdef INET6 1494 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1495 #endif /* INET6 */ 1496 } 1497 1498 #ifdef INET6 1499 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1500 #else /* INET6 */ 1501 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1502 #endif /* INET6 */ 1503 if (max_protohdr < TCP_MINPROTOHDR) 1504 max_protohdr = TCP_MINPROTOHDR; 1505 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1506 panic("tcp_init"); 1507 #undef TCP_MINPROTOHDR 1508 1509 ISN_LOCK_INIT(); 1510 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1511 SHUTDOWN_PRI_DEFAULT); 1512 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1513 EVENTHANDLER_PRI_ANY); 1514 1515 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1516 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1517 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1518 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1519 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1520 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1521 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1522 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1523 #ifdef TCPPCAP 1524 tcp_pcap_init(); 1525 #endif 1526 } 1527 1528 #ifdef VIMAGE 1529 static void 1530 tcp_destroy(void *unused __unused) 1531 { 1532 int n; 1533 #ifdef TCP_HHOOK 1534 int error; 1535 #endif 1536 1537 /* 1538 * All our processes are gone, all our sockets should be cleaned 1539 * up, which means, we should be past the tcp_discardcb() calls. 1540 * Sleep to let all tcpcb timers really disappear and cleanup. 1541 */ 1542 for (;;) { 1543 INP_LIST_RLOCK(&V_tcbinfo); 1544 n = V_tcbinfo.ipi_count; 1545 INP_LIST_RUNLOCK(&V_tcbinfo); 1546 if (n == 0) 1547 break; 1548 pause("tcpdes", hz / 10); 1549 } 1550 tcp_hc_destroy(); 1551 syncache_destroy(); 1552 tcp_tw_destroy(); 1553 in_pcbinfo_destroy(&V_tcbinfo); 1554 /* tcp_discardcb() clears the sack_holes up. */ 1555 uma_zdestroy(V_sack_hole_zone); 1556 uma_zdestroy(V_tcpcb_zone); 1557 1558 /* 1559 * Cannot free the zone until all tcpcbs are released as we attach 1560 * the allocations to them. 1561 */ 1562 tcp_fastopen_destroy(); 1563 1564 #ifdef TCP_HHOOK 1565 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1566 if (error != 0) { 1567 printf("%s: WARNING: unable to deregister helper hook " 1568 "type=%d, id=%d: error %d returned\n", __func__, 1569 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1570 } 1571 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1572 if (error != 0) { 1573 printf("%s: WARNING: unable to deregister helper hook " 1574 "type=%d, id=%d: error %d returned\n", __func__, 1575 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1576 } 1577 #endif 1578 } 1579 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1580 #endif 1581 1582 void 1583 tcp_fini(void *xtp) 1584 { 1585 1586 } 1587 1588 /* 1589 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1590 * tcp_template used to store this data in mbufs, but we now recopy it out 1591 * of the tcpcb each time to conserve mbufs. 1592 */ 1593 void 1594 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1595 { 1596 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1597 1598 INP_WLOCK_ASSERT(inp); 1599 1600 #ifdef INET6 1601 if ((inp->inp_vflag & INP_IPV6) != 0) { 1602 struct ip6_hdr *ip6; 1603 1604 ip6 = (struct ip6_hdr *)ip_ptr; 1605 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1606 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1607 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1608 (IPV6_VERSION & IPV6_VERSION_MASK); 1609 if (port == 0) 1610 ip6->ip6_nxt = IPPROTO_TCP; 1611 else 1612 ip6->ip6_nxt = IPPROTO_UDP; 1613 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1614 ip6->ip6_src = inp->in6p_laddr; 1615 ip6->ip6_dst = inp->in6p_faddr; 1616 } 1617 #endif /* INET6 */ 1618 #if defined(INET6) && defined(INET) 1619 else 1620 #endif 1621 #ifdef INET 1622 { 1623 struct ip *ip; 1624 1625 ip = (struct ip *)ip_ptr; 1626 ip->ip_v = IPVERSION; 1627 ip->ip_hl = 5; 1628 ip->ip_tos = inp->inp_ip_tos; 1629 ip->ip_len = 0; 1630 ip->ip_id = 0; 1631 ip->ip_off = 0; 1632 ip->ip_ttl = inp->inp_ip_ttl; 1633 ip->ip_sum = 0; 1634 if (port == 0) 1635 ip->ip_p = IPPROTO_TCP; 1636 else 1637 ip->ip_p = IPPROTO_UDP; 1638 ip->ip_src = inp->inp_laddr; 1639 ip->ip_dst = inp->inp_faddr; 1640 } 1641 #endif /* INET */ 1642 th->th_sport = inp->inp_lport; 1643 th->th_dport = inp->inp_fport; 1644 th->th_seq = 0; 1645 th->th_ack = 0; 1646 th->th_x2 = 0; 1647 th->th_off = 5; 1648 th->th_flags = 0; 1649 th->th_win = 0; 1650 th->th_urp = 0; 1651 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1652 } 1653 1654 /* 1655 * Create template to be used to send tcp packets on a connection. 1656 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1657 * use for this function is in keepalives, which use tcp_respond. 1658 */ 1659 struct tcptemp * 1660 tcpip_maketemplate(struct inpcb *inp) 1661 { 1662 struct tcptemp *t; 1663 1664 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1665 if (t == NULL) 1666 return (NULL); 1667 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1668 return (t); 1669 } 1670 1671 /* 1672 * Send a single message to the TCP at address specified by 1673 * the given TCP/IP header. If m == NULL, then we make a copy 1674 * of the tcpiphdr at th and send directly to the addressed host. 1675 * This is used to force keep alive messages out using the TCP 1676 * template for a connection. If flags are given then we send 1677 * a message back to the TCP which originated the segment th, 1678 * and discard the mbuf containing it and any other attached mbufs. 1679 * 1680 * In any case the ack and sequence number of the transmitted 1681 * segment are as specified by the parameters. 1682 * 1683 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1684 */ 1685 void 1686 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1687 tcp_seq ack, tcp_seq seq, int flags) 1688 { 1689 struct tcpopt to; 1690 struct inpcb *inp; 1691 struct ip *ip; 1692 struct mbuf *optm; 1693 struct udphdr *uh = NULL; 1694 struct tcphdr *nth; 1695 u_char *optp; 1696 #ifdef INET6 1697 struct ip6_hdr *ip6; 1698 int isipv6; 1699 #endif /* INET6 */ 1700 int optlen, tlen, win, ulen; 1701 bool incl_opts; 1702 uint16_t port; 1703 1704 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1705 NET_EPOCH_ASSERT(); 1706 1707 #ifdef INET6 1708 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1709 ip6 = ipgen; 1710 #endif /* INET6 */ 1711 ip = ipgen; 1712 1713 if (tp != NULL) { 1714 inp = tp->t_inpcb; 1715 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1716 INP_LOCK_ASSERT(inp); 1717 } else 1718 inp = NULL; 1719 1720 if (m != NULL) { 1721 #ifdef INET6 1722 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1723 port = m->m_pkthdr.tcp_tun_port; 1724 else 1725 #endif 1726 if (ip && (ip->ip_p == IPPROTO_UDP)) 1727 port = m->m_pkthdr.tcp_tun_port; 1728 else 1729 port = 0; 1730 } else 1731 port = tp->t_port; 1732 1733 incl_opts = false; 1734 win = 0; 1735 if (tp != NULL) { 1736 if (!(flags & TH_RST)) { 1737 win = sbspace(&inp->inp_socket->so_rcv); 1738 if (win > TCP_MAXWIN << tp->rcv_scale) 1739 win = TCP_MAXWIN << tp->rcv_scale; 1740 } 1741 if ((tp->t_flags & TF_NOOPT) == 0) 1742 incl_opts = true; 1743 } 1744 if (m == NULL) { 1745 m = m_gethdr(M_NOWAIT, MT_DATA); 1746 if (m == NULL) 1747 return; 1748 m->m_data += max_linkhdr; 1749 #ifdef INET6 1750 if (isipv6) { 1751 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1752 sizeof(struct ip6_hdr)); 1753 ip6 = mtod(m, struct ip6_hdr *); 1754 nth = (struct tcphdr *)(ip6 + 1); 1755 if (port) { 1756 /* Insert a UDP header */ 1757 uh = (struct udphdr *)nth; 1758 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1759 uh->uh_dport = port; 1760 nth = (struct tcphdr *)(uh + 1); 1761 } 1762 } else 1763 #endif /* INET6 */ 1764 { 1765 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1766 ip = mtod(m, struct ip *); 1767 nth = (struct tcphdr *)(ip + 1); 1768 if (port) { 1769 /* Insert a UDP header */ 1770 uh = (struct udphdr *)nth; 1771 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1772 uh->uh_dport = port; 1773 nth = (struct tcphdr *)(uh + 1); 1774 } 1775 } 1776 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1777 flags = TH_ACK; 1778 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1779 struct mbuf *n; 1780 1781 /* Can't reuse 'm', allocate a new mbuf. */ 1782 n = m_gethdr(M_NOWAIT, MT_DATA); 1783 if (n == NULL) { 1784 m_freem(m); 1785 return; 1786 } 1787 1788 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1789 m_freem(m); 1790 m_freem(n); 1791 return; 1792 } 1793 1794 n->m_data += max_linkhdr; 1795 /* m_len is set later */ 1796 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1797 #ifdef INET6 1798 if (isipv6) { 1799 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1800 sizeof(struct ip6_hdr)); 1801 ip6 = mtod(n, struct ip6_hdr *); 1802 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1803 nth = (struct tcphdr *)(ip6 + 1); 1804 if (port) { 1805 /* Insert a UDP header */ 1806 uh = (struct udphdr *)nth; 1807 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1808 uh->uh_dport = port; 1809 nth = (struct tcphdr *)(uh + 1); 1810 } 1811 } else 1812 #endif /* INET6 */ 1813 { 1814 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1815 ip = mtod(n, struct ip *); 1816 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1817 nth = (struct tcphdr *)(ip + 1); 1818 if (port) { 1819 /* Insert a UDP header */ 1820 uh = (struct udphdr *)nth; 1821 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1822 uh->uh_dport = port; 1823 nth = (struct tcphdr *)(uh + 1); 1824 } 1825 } 1826 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1827 xchg(nth->th_dport, nth->th_sport, uint16_t); 1828 th = nth; 1829 m_freem(m); 1830 m = n; 1831 } else { 1832 /* 1833 * reuse the mbuf. 1834 * XXX MRT We inherit the FIB, which is lucky. 1835 */ 1836 m_freem(m->m_next); 1837 m->m_next = NULL; 1838 m->m_data = (caddr_t)ipgen; 1839 /* m_len is set later */ 1840 #ifdef INET6 1841 if (isipv6) { 1842 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1843 nth = (struct tcphdr *)(ip6 + 1); 1844 } else 1845 #endif /* INET6 */ 1846 { 1847 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1848 nth = (struct tcphdr *)(ip + 1); 1849 } 1850 if (th != nth) { 1851 /* 1852 * this is usually a case when an extension header 1853 * exists between the IPv6 header and the 1854 * TCP header. 1855 */ 1856 nth->th_sport = th->th_sport; 1857 nth->th_dport = th->th_dport; 1858 } 1859 xchg(nth->th_dport, nth->th_sport, uint16_t); 1860 #undef xchg 1861 } 1862 tlen = 0; 1863 #ifdef INET6 1864 if (isipv6) 1865 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1866 #endif 1867 #if defined(INET) && defined(INET6) 1868 else 1869 #endif 1870 #ifdef INET 1871 tlen = sizeof (struct tcpiphdr); 1872 #endif 1873 if (port) 1874 tlen += sizeof (struct udphdr); 1875 #ifdef INVARIANTS 1876 m->m_len = 0; 1877 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1878 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1879 m, tlen, (long)M_TRAILINGSPACE(m))); 1880 #endif 1881 m->m_len = tlen; 1882 to.to_flags = 0; 1883 if (incl_opts) { 1884 /* Make sure we have room. */ 1885 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1886 m->m_next = m_get(M_NOWAIT, MT_DATA); 1887 if (m->m_next) { 1888 optp = mtod(m->m_next, u_char *); 1889 optm = m->m_next; 1890 } else 1891 incl_opts = false; 1892 } else { 1893 optp = (u_char *) (nth + 1); 1894 optm = m; 1895 } 1896 } 1897 if (incl_opts) { 1898 /* Timestamps. */ 1899 if (tp->t_flags & TF_RCVD_TSTMP) { 1900 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1901 to.to_tsecr = tp->ts_recent; 1902 to.to_flags |= TOF_TS; 1903 } 1904 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1905 /* TCP-MD5 (RFC2385). */ 1906 if (tp->t_flags & TF_SIGNATURE) 1907 to.to_flags |= TOF_SIGNATURE; 1908 #endif 1909 /* Add the options. */ 1910 tlen += optlen = tcp_addoptions(&to, optp); 1911 1912 /* Update m_len in the correct mbuf. */ 1913 optm->m_len += optlen; 1914 } else 1915 optlen = 0; 1916 #ifdef INET6 1917 if (isipv6) { 1918 if (uh) { 1919 ulen = tlen - sizeof(struct ip6_hdr); 1920 uh->uh_ulen = htons(ulen); 1921 } 1922 ip6->ip6_flow = 0; 1923 ip6->ip6_vfc = IPV6_VERSION; 1924 if (port) 1925 ip6->ip6_nxt = IPPROTO_UDP; 1926 else 1927 ip6->ip6_nxt = IPPROTO_TCP; 1928 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1929 } 1930 #endif 1931 #if defined(INET) && defined(INET6) 1932 else 1933 #endif 1934 #ifdef INET 1935 { 1936 if (uh) { 1937 ulen = tlen - sizeof(struct ip); 1938 uh->uh_ulen = htons(ulen); 1939 } 1940 ip->ip_len = htons(tlen); 1941 ip->ip_ttl = V_ip_defttl; 1942 if (port) { 1943 ip->ip_p = IPPROTO_UDP; 1944 } else { 1945 ip->ip_p = IPPROTO_TCP; 1946 } 1947 if (V_path_mtu_discovery) 1948 ip->ip_off |= htons(IP_DF); 1949 } 1950 #endif 1951 m->m_pkthdr.len = tlen; 1952 m->m_pkthdr.rcvif = NULL; 1953 #ifdef MAC 1954 if (inp != NULL) { 1955 /* 1956 * Packet is associated with a socket, so allow the 1957 * label of the response to reflect the socket label. 1958 */ 1959 INP_LOCK_ASSERT(inp); 1960 mac_inpcb_create_mbuf(inp, m); 1961 } else { 1962 /* 1963 * Packet is not associated with a socket, so possibly 1964 * update the label in place. 1965 */ 1966 mac_netinet_tcp_reply(m); 1967 } 1968 #endif 1969 nth->th_seq = htonl(seq); 1970 nth->th_ack = htonl(ack); 1971 nth->th_x2 = 0; 1972 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1973 nth->th_flags = flags; 1974 if (tp != NULL) 1975 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1976 else 1977 nth->th_win = htons((u_short)win); 1978 nth->th_urp = 0; 1979 1980 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1981 if (to.to_flags & TOF_SIGNATURE) { 1982 if (!TCPMD5_ENABLED() || 1983 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1984 m_freem(m); 1985 return; 1986 } 1987 } 1988 #endif 1989 1990 #ifdef INET6 1991 if (isipv6) { 1992 if (port) { 1993 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 1994 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1995 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 1996 nth->th_sum = 0; 1997 } else { 1998 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1999 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2000 nth->th_sum = in6_cksum_pseudo(ip6, 2001 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2002 } 2003 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2004 NULL, NULL); 2005 } 2006 #endif /* INET6 */ 2007 #if defined(INET6) && defined(INET) 2008 else 2009 #endif 2010 #ifdef INET 2011 { 2012 if (port) { 2013 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2014 htons(ulen + IPPROTO_UDP)); 2015 m->m_pkthdr.csum_flags = CSUM_UDP; 2016 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2017 nth->th_sum = 0; 2018 } else { 2019 m->m_pkthdr.csum_flags = CSUM_TCP; 2020 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2021 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2022 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2023 } 2024 } 2025 #endif /* INET */ 2026 #ifdef TCPDEBUG 2027 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2028 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2029 #endif 2030 TCP_PROBE3(debug__output, tp, th, m); 2031 if (flags & TH_RST) 2032 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2033 2034 #ifdef INET6 2035 if (isipv6) { 2036 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2037 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2038 } 2039 #endif /* INET6 */ 2040 #if defined(INET) && defined(INET6) 2041 else 2042 #endif 2043 #ifdef INET 2044 { 2045 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2046 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 2047 } 2048 #endif 2049 } 2050 2051 /* 2052 * Create a new TCP control block, making an 2053 * empty reassembly queue and hooking it to the argument 2054 * protocol control block. The `inp' parameter must have 2055 * come from the zone allocator set up in tcp_init(). 2056 */ 2057 struct tcpcb * 2058 tcp_newtcpcb(struct inpcb *inp) 2059 { 2060 struct tcpcb_mem *tm; 2061 struct tcpcb *tp; 2062 #ifdef INET6 2063 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2064 #endif /* INET6 */ 2065 2066 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2067 if (tm == NULL) 2068 return (NULL); 2069 tp = &tm->tcb; 2070 2071 /* Initialise cc_var struct for this tcpcb. */ 2072 tp->ccv = &tm->ccv; 2073 tp->ccv->type = IPPROTO_TCP; 2074 tp->ccv->ccvc.tcp = tp; 2075 rw_rlock(&tcp_function_lock); 2076 tp->t_fb = tcp_func_set_ptr; 2077 refcount_acquire(&tp->t_fb->tfb_refcnt); 2078 rw_runlock(&tcp_function_lock); 2079 /* 2080 * Use the current system default CC algorithm. 2081 */ 2082 CC_LIST_RLOCK(); 2083 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 2084 CC_ALGO(tp) = CC_DEFAULT(); 2085 CC_LIST_RUNLOCK(); 2086 /* 2087 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2088 * is called. 2089 */ 2090 in_pcbref(inp); /* Reference for tcpcb */ 2091 tp->t_inpcb = inp; 2092 2093 if (CC_ALGO(tp)->cb_init != NULL) 2094 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 2095 if (tp->t_fb->tfb_tcp_fb_fini) 2096 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2097 in_pcbrele_wlocked(inp); 2098 refcount_release(&tp->t_fb->tfb_refcnt); 2099 uma_zfree(V_tcpcb_zone, tm); 2100 return (NULL); 2101 } 2102 2103 #ifdef TCP_HHOOK 2104 tp->osd = &tm->osd; 2105 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2106 if (tp->t_fb->tfb_tcp_fb_fini) 2107 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2108 in_pcbrele_wlocked(inp); 2109 refcount_release(&tp->t_fb->tfb_refcnt); 2110 uma_zfree(V_tcpcb_zone, tm); 2111 return (NULL); 2112 } 2113 #endif 2114 2115 #ifdef VIMAGE 2116 tp->t_vnet = inp->inp_vnet; 2117 #endif 2118 tp->t_timers = &tm->tt; 2119 TAILQ_INIT(&tp->t_segq); 2120 tp->t_maxseg = 2121 #ifdef INET6 2122 isipv6 ? V_tcp_v6mssdflt : 2123 #endif /* INET6 */ 2124 V_tcp_mssdflt; 2125 2126 /* Set up our timeouts. */ 2127 callout_init(&tp->t_timers->tt_rexmt, 1); 2128 callout_init(&tp->t_timers->tt_persist, 1); 2129 callout_init(&tp->t_timers->tt_keep, 1); 2130 callout_init(&tp->t_timers->tt_2msl, 1); 2131 callout_init(&tp->t_timers->tt_delack, 1); 2132 2133 if (V_tcp_do_rfc1323) 2134 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2135 if (V_tcp_do_sack) 2136 tp->t_flags |= TF_SACK_PERMIT; 2137 TAILQ_INIT(&tp->snd_holes); 2138 2139 /* 2140 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2141 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2142 * reasonable initial retransmit time. 2143 */ 2144 tp->t_srtt = TCPTV_SRTTBASE; 2145 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2146 tp->t_rttmin = tcp_rexmit_min; 2147 tp->t_rxtcur = tcp_rexmit_initial; 2148 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2149 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2150 tp->t_rcvtime = ticks; 2151 /* 2152 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2153 * because the socket may be bound to an IPv6 wildcard address, 2154 * which may match an IPv4-mapped IPv6 address. 2155 */ 2156 inp->inp_ip_ttl = V_ip_defttl; 2157 inp->inp_ppcb = tp; 2158 #ifdef TCPPCAP 2159 /* 2160 * Init the TCP PCAP queues. 2161 */ 2162 tcp_pcap_tcpcb_init(tp); 2163 #endif 2164 #ifdef TCP_BLACKBOX 2165 /* Initialize the per-TCPCB log data. */ 2166 tcp_log_tcpcbinit(tp); 2167 #endif 2168 tp->t_pacing_rate = -1; 2169 if (tp->t_fb->tfb_tcp_fb_init) { 2170 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2171 refcount_release(&tp->t_fb->tfb_refcnt); 2172 in_pcbrele_wlocked(inp); 2173 uma_zfree(V_tcpcb_zone, tm); 2174 return (NULL); 2175 } 2176 } 2177 #ifdef STATS 2178 if (V_tcp_perconn_stats_enable == 1) 2179 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2180 #endif 2181 if (V_tcp_do_lrd) 2182 tp->t_flags |= TF_LRD; 2183 return (tp); /* XXX */ 2184 } 2185 2186 /* 2187 * Switch the congestion control algorithm back to NewReno for any active 2188 * control blocks using an algorithm which is about to go away. 2189 * This ensures the CC framework can allow the unload to proceed without leaving 2190 * any dangling pointers which would trigger a panic. 2191 * Returning non-zero would inform the CC framework that something went wrong 2192 * and it would be unsafe to allow the unload to proceed. However, there is no 2193 * way for this to occur with this implementation so we always return zero. 2194 */ 2195 int 2196 tcp_ccalgounload(struct cc_algo *unload_algo) 2197 { 2198 struct cc_algo *tmpalgo; 2199 struct inpcb *inp; 2200 struct tcpcb *tp; 2201 VNET_ITERATOR_DECL(vnet_iter); 2202 2203 /* 2204 * Check all active control blocks across all network stacks and change 2205 * any that are using "unload_algo" back to NewReno. If "unload_algo" 2206 * requires cleanup code to be run, call it. 2207 */ 2208 VNET_LIST_RLOCK(); 2209 VNET_FOREACH(vnet_iter) { 2210 CURVNET_SET(vnet_iter); 2211 INP_INFO_WLOCK(&V_tcbinfo); 2212 /* 2213 * New connections already part way through being initialised 2214 * with the CC algo we're removing will not race with this code 2215 * because the INP_INFO_WLOCK is held during initialisation. We 2216 * therefore don't enter the loop below until the connection 2217 * list has stabilised. 2218 */ 2219 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 2220 INP_WLOCK(inp); 2221 /* Important to skip tcptw structs. */ 2222 if (!(inp->inp_flags & INP_TIMEWAIT) && 2223 (tp = intotcpcb(inp)) != NULL) { 2224 /* 2225 * By holding INP_WLOCK here, we are assured 2226 * that the connection is not currently 2227 * executing inside the CC module's functions 2228 * i.e. it is safe to make the switch back to 2229 * NewReno. 2230 */ 2231 if (CC_ALGO(tp) == unload_algo) { 2232 tmpalgo = CC_ALGO(tp); 2233 if (tmpalgo->cb_destroy != NULL) 2234 tmpalgo->cb_destroy(tp->ccv); 2235 CC_DATA(tp) = NULL; 2236 /* 2237 * NewReno may allocate memory on 2238 * demand for certain stateful 2239 * configuration as needed, but is 2240 * coded to never fail on memory 2241 * allocation failure so it is a safe 2242 * fallback. 2243 */ 2244 CC_ALGO(tp) = &newreno_cc_algo; 2245 } 2246 } 2247 INP_WUNLOCK(inp); 2248 } 2249 INP_INFO_WUNLOCK(&V_tcbinfo); 2250 CURVNET_RESTORE(); 2251 } 2252 VNET_LIST_RUNLOCK(); 2253 2254 return (0); 2255 } 2256 2257 /* 2258 * Drop a TCP connection, reporting 2259 * the specified error. If connection is synchronized, 2260 * then send a RST to peer. 2261 */ 2262 struct tcpcb * 2263 tcp_drop(struct tcpcb *tp, int errno) 2264 { 2265 struct socket *so = tp->t_inpcb->inp_socket; 2266 2267 NET_EPOCH_ASSERT(); 2268 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2269 INP_WLOCK_ASSERT(tp->t_inpcb); 2270 2271 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2272 tcp_state_change(tp, TCPS_CLOSED); 2273 (void) tp->t_fb->tfb_tcp_output(tp); 2274 TCPSTAT_INC(tcps_drops); 2275 } else 2276 TCPSTAT_INC(tcps_conndrops); 2277 if (errno == ETIMEDOUT && tp->t_softerror) 2278 errno = tp->t_softerror; 2279 so->so_error = errno; 2280 return (tcp_close(tp)); 2281 } 2282 2283 void 2284 tcp_discardcb(struct tcpcb *tp) 2285 { 2286 struct inpcb *inp = tp->t_inpcb; 2287 struct socket *so = inp->inp_socket; 2288 #ifdef INET6 2289 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2290 #endif /* INET6 */ 2291 int released __unused; 2292 2293 INP_WLOCK_ASSERT(inp); 2294 2295 /* 2296 * Make sure that all of our timers are stopped before we delete the 2297 * PCB. 2298 * 2299 * If stopping a timer fails, we schedule a discard function in same 2300 * callout, and the last discard function called will take care of 2301 * deleting the tcpcb. 2302 */ 2303 tp->t_timers->tt_draincnt = 0; 2304 tcp_timer_stop(tp, TT_REXMT); 2305 tcp_timer_stop(tp, TT_PERSIST); 2306 tcp_timer_stop(tp, TT_KEEP); 2307 tcp_timer_stop(tp, TT_2MSL); 2308 tcp_timer_stop(tp, TT_DELACK); 2309 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2310 /* 2311 * Call the stop-all function of the methods, 2312 * this function should call the tcp_timer_stop() 2313 * method with each of the function specific timeouts. 2314 * That stop will be called via the tfb_tcp_timer_stop() 2315 * which should use the async drain function of the 2316 * callout system (see tcp_var.h). 2317 */ 2318 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2319 } 2320 2321 /* free the reassembly queue, if any */ 2322 tcp_reass_flush(tp); 2323 2324 #ifdef TCP_OFFLOAD 2325 /* Disconnect offload device, if any. */ 2326 if (tp->t_flags & TF_TOE) 2327 tcp_offload_detach(tp); 2328 #endif 2329 2330 tcp_free_sackholes(tp); 2331 2332 #ifdef TCPPCAP 2333 /* Free the TCP PCAP queues. */ 2334 tcp_pcap_drain(&(tp->t_inpkts)); 2335 tcp_pcap_drain(&(tp->t_outpkts)); 2336 #endif 2337 2338 /* Allow the CC algorithm to clean up after itself. */ 2339 if (CC_ALGO(tp)->cb_destroy != NULL) 2340 CC_ALGO(tp)->cb_destroy(tp->ccv); 2341 CC_DATA(tp) = NULL; 2342 2343 #ifdef TCP_HHOOK 2344 khelp_destroy_osd(tp->osd); 2345 #endif 2346 #ifdef STATS 2347 stats_blob_destroy(tp->t_stats); 2348 #endif 2349 2350 CC_ALGO(tp) = NULL; 2351 inp->inp_ppcb = NULL; 2352 if (tp->t_timers->tt_draincnt == 0) { 2353 /* We own the last reference on tcpcb, let's free it. */ 2354 #ifdef TCP_BLACKBOX 2355 tcp_log_tcpcbfini(tp); 2356 #endif 2357 TCPSTATES_DEC(tp->t_state); 2358 if (tp->t_fb->tfb_tcp_fb_fini) 2359 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2360 2361 /* 2362 * If we got enough samples through the srtt filter, 2363 * save the rtt and rttvar in the routing entry. 2364 * 'Enough' is arbitrarily defined as 4 rtt samples. 2365 * 4 samples is enough for the srtt filter to converge 2366 * to within enough % of the correct value; fewer samples 2367 * and we could save a bogus rtt. The danger is not high 2368 * as tcp quickly recovers from everything. 2369 * XXX: Works very well but needs some more statistics! 2370 * 2371 * XXXRRS: Updating must be after the stack fini() since 2372 * that may be converting some internal representation of 2373 * say srtt etc into the general one used by other stacks. 2374 * Lets also at least protect against the so being NULL 2375 * as RW stated below. 2376 */ 2377 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2378 struct hc_metrics_lite metrics; 2379 uint32_t ssthresh; 2380 2381 bzero(&metrics, sizeof(metrics)); 2382 /* 2383 * Update the ssthresh always when the conditions below 2384 * are satisfied. This gives us better new start value 2385 * for the congestion avoidance for new connections. 2386 * ssthresh is only set if packet loss occurred on a session. 2387 * 2388 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2389 * being torn down. Ideally this code would not use 'so'. 2390 */ 2391 ssthresh = tp->snd_ssthresh; 2392 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2393 /* 2394 * convert the limit from user data bytes to 2395 * packets then to packet data bytes. 2396 */ 2397 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2398 if (ssthresh < 2) 2399 ssthresh = 2; 2400 ssthresh *= (tp->t_maxseg + 2401 #ifdef INET6 2402 (isipv6 ? sizeof (struct ip6_hdr) + 2403 sizeof (struct tcphdr) : 2404 #endif 2405 sizeof (struct tcpiphdr) 2406 #ifdef INET6 2407 ) 2408 #endif 2409 ); 2410 } else 2411 ssthresh = 0; 2412 metrics.rmx_ssthresh = ssthresh; 2413 2414 metrics.rmx_rtt = tp->t_srtt; 2415 metrics.rmx_rttvar = tp->t_rttvar; 2416 metrics.rmx_cwnd = tp->snd_cwnd; 2417 metrics.rmx_sendpipe = 0; 2418 metrics.rmx_recvpipe = 0; 2419 2420 tcp_hc_update(&inp->inp_inc, &metrics); 2421 } 2422 refcount_release(&tp->t_fb->tfb_refcnt); 2423 tp->t_inpcb = NULL; 2424 uma_zfree(V_tcpcb_zone, tp); 2425 released = in_pcbrele_wlocked(inp); 2426 KASSERT(!released, ("%s: inp %p should not have been released " 2427 "here", __func__, inp)); 2428 } 2429 } 2430 2431 void 2432 tcp_timer_discard(void *ptp) 2433 { 2434 struct inpcb *inp; 2435 struct tcpcb *tp; 2436 struct epoch_tracker et; 2437 2438 tp = (struct tcpcb *)ptp; 2439 CURVNET_SET(tp->t_vnet); 2440 NET_EPOCH_ENTER(et); 2441 inp = tp->t_inpcb; 2442 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 2443 __func__, tp)); 2444 INP_WLOCK(inp); 2445 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 2446 ("%s: tcpcb has to be stopped here", __func__)); 2447 tp->t_timers->tt_draincnt--; 2448 if (tp->t_timers->tt_draincnt == 0) { 2449 /* We own the last reference on this tcpcb, let's free it. */ 2450 #ifdef TCP_BLACKBOX 2451 tcp_log_tcpcbfini(tp); 2452 #endif 2453 TCPSTATES_DEC(tp->t_state); 2454 if (tp->t_fb->tfb_tcp_fb_fini) 2455 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2456 refcount_release(&tp->t_fb->tfb_refcnt); 2457 tp->t_inpcb = NULL; 2458 uma_zfree(V_tcpcb_zone, tp); 2459 if (in_pcbrele_wlocked(inp)) { 2460 NET_EPOCH_EXIT(et); 2461 CURVNET_RESTORE(); 2462 return; 2463 } 2464 } 2465 INP_WUNLOCK(inp); 2466 NET_EPOCH_EXIT(et); 2467 CURVNET_RESTORE(); 2468 } 2469 2470 /* 2471 * Attempt to close a TCP control block, marking it as dropped, and freeing 2472 * the socket if we hold the only reference. 2473 */ 2474 struct tcpcb * 2475 tcp_close(struct tcpcb *tp) 2476 { 2477 struct inpcb *inp = tp->t_inpcb; 2478 struct socket *so; 2479 2480 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2481 INP_WLOCK_ASSERT(inp); 2482 2483 #ifdef TCP_OFFLOAD 2484 if (tp->t_state == TCPS_LISTEN) 2485 tcp_offload_listen_stop(tp); 2486 #endif 2487 /* 2488 * This releases the TFO pending counter resource for TFO listen 2489 * sockets as well as passively-created TFO sockets that transition 2490 * from SYN_RECEIVED to CLOSED. 2491 */ 2492 if (tp->t_tfo_pending) { 2493 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2494 tp->t_tfo_pending = NULL; 2495 } 2496 in_pcbdrop(inp); 2497 TCPSTAT_INC(tcps_closed); 2498 if (tp->t_state != TCPS_CLOSED) 2499 tcp_state_change(tp, TCPS_CLOSED); 2500 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2501 so = inp->inp_socket; 2502 soisdisconnected(so); 2503 if (inp->inp_flags & INP_SOCKREF) { 2504 KASSERT(so->so_state & SS_PROTOREF, 2505 ("tcp_close: !SS_PROTOREF")); 2506 inp->inp_flags &= ~INP_SOCKREF; 2507 INP_WUNLOCK(inp); 2508 SOCK_LOCK(so); 2509 so->so_state &= ~SS_PROTOREF; 2510 sofree(so); 2511 return (NULL); 2512 } 2513 return (tp); 2514 } 2515 2516 void 2517 tcp_drain(void) 2518 { 2519 VNET_ITERATOR_DECL(vnet_iter); 2520 2521 if (!do_tcpdrain) 2522 return; 2523 2524 VNET_LIST_RLOCK_NOSLEEP(); 2525 VNET_FOREACH(vnet_iter) { 2526 CURVNET_SET(vnet_iter); 2527 struct inpcb *inpb; 2528 struct tcpcb *tcpb; 2529 2530 /* 2531 * Walk the tcpbs, if existing, and flush the reassembly queue, 2532 * if there is one... 2533 * XXX: The "Net/3" implementation doesn't imply that the TCP 2534 * reassembly queue should be flushed, but in a situation 2535 * where we're really low on mbufs, this is potentially 2536 * useful. 2537 */ 2538 INP_INFO_WLOCK(&V_tcbinfo); 2539 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2540 INP_WLOCK(inpb); 2541 if (inpb->inp_flags & INP_TIMEWAIT) { 2542 INP_WUNLOCK(inpb); 2543 continue; 2544 } 2545 if ((tcpb = intotcpcb(inpb)) != NULL) { 2546 tcp_reass_flush(tcpb); 2547 tcp_clean_sackreport(tcpb); 2548 #ifdef TCP_BLACKBOX 2549 tcp_log_drain(tcpb); 2550 #endif 2551 #ifdef TCPPCAP 2552 if (tcp_pcap_aggressive_free) { 2553 /* Free the TCP PCAP queues. */ 2554 tcp_pcap_drain(&(tcpb->t_inpkts)); 2555 tcp_pcap_drain(&(tcpb->t_outpkts)); 2556 } 2557 #endif 2558 } 2559 INP_WUNLOCK(inpb); 2560 } 2561 INP_INFO_WUNLOCK(&V_tcbinfo); 2562 CURVNET_RESTORE(); 2563 } 2564 VNET_LIST_RUNLOCK_NOSLEEP(); 2565 } 2566 2567 /* 2568 * Notify a tcp user of an asynchronous error; 2569 * store error as soft error, but wake up user 2570 * (for now, won't do anything until can select for soft error). 2571 * 2572 * Do not wake up user since there currently is no mechanism for 2573 * reporting soft errors (yet - a kqueue filter may be added). 2574 */ 2575 static struct inpcb * 2576 tcp_notify(struct inpcb *inp, int error) 2577 { 2578 struct tcpcb *tp; 2579 2580 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2581 INP_WLOCK_ASSERT(inp); 2582 2583 if ((inp->inp_flags & INP_TIMEWAIT) || 2584 (inp->inp_flags & INP_DROPPED)) 2585 return (inp); 2586 2587 tp = intotcpcb(inp); 2588 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2589 2590 /* 2591 * Ignore some errors if we are hooked up. 2592 * If connection hasn't completed, has retransmitted several times, 2593 * and receives a second error, give up now. This is better 2594 * than waiting a long time to establish a connection that 2595 * can never complete. 2596 */ 2597 if (tp->t_state == TCPS_ESTABLISHED && 2598 (error == EHOSTUNREACH || error == ENETUNREACH || 2599 error == EHOSTDOWN)) { 2600 if (inp->inp_route.ro_nh) { 2601 NH_FREE(inp->inp_route.ro_nh); 2602 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2603 } 2604 return (inp); 2605 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2606 tp->t_softerror) { 2607 tp = tcp_drop(tp, error); 2608 if (tp != NULL) 2609 return (inp); 2610 else 2611 return (NULL); 2612 } else { 2613 tp->t_softerror = error; 2614 return (inp); 2615 } 2616 #if 0 2617 wakeup( &so->so_timeo); 2618 sorwakeup(so); 2619 sowwakeup(so); 2620 #endif 2621 } 2622 2623 static int 2624 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2625 { 2626 struct epoch_tracker et; 2627 struct inpcb *inp; 2628 struct xinpgen xig; 2629 int error; 2630 2631 if (req->newptr != NULL) 2632 return (EPERM); 2633 2634 if (req->oldptr == NULL) { 2635 int n; 2636 2637 n = V_tcbinfo.ipi_count + 2638 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2639 n += imax(n / 8, 10); 2640 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2641 return (0); 2642 } 2643 2644 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2645 return (error); 2646 2647 bzero(&xig, sizeof(xig)); 2648 xig.xig_len = sizeof xig; 2649 xig.xig_count = V_tcbinfo.ipi_count + 2650 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2651 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2652 xig.xig_sogen = so_gencnt; 2653 error = SYSCTL_OUT(req, &xig, sizeof xig); 2654 if (error) 2655 return (error); 2656 2657 error = syncache_pcblist(req); 2658 if (error) 2659 return (error); 2660 2661 NET_EPOCH_ENTER(et); 2662 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2663 inp != NULL; 2664 inp = CK_LIST_NEXT(inp, inp_list)) { 2665 INP_RLOCK(inp); 2666 if (inp->inp_gencnt <= xig.xig_gen) { 2667 int crerr; 2668 2669 /* 2670 * XXX: This use of cr_cansee(), introduced with 2671 * TCP state changes, is not quite right, but for 2672 * now, better than nothing. 2673 */ 2674 if (inp->inp_flags & INP_TIMEWAIT) { 2675 if (intotw(inp) != NULL) 2676 crerr = cr_cansee(req->td->td_ucred, 2677 intotw(inp)->tw_cred); 2678 else 2679 crerr = EINVAL; /* Skip this inp. */ 2680 } else 2681 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2682 if (crerr == 0) { 2683 struct xtcpcb xt; 2684 2685 tcp_inptoxtp(inp, &xt); 2686 INP_RUNLOCK(inp); 2687 error = SYSCTL_OUT(req, &xt, sizeof xt); 2688 if (error) 2689 break; 2690 else 2691 continue; 2692 } 2693 } 2694 INP_RUNLOCK(inp); 2695 } 2696 NET_EPOCH_EXIT(et); 2697 2698 if (!error) { 2699 /* 2700 * Give the user an updated idea of our state. 2701 * If the generation differs from what we told 2702 * her before, she knows that something happened 2703 * while we were processing this request, and it 2704 * might be necessary to retry. 2705 */ 2706 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2707 xig.xig_sogen = so_gencnt; 2708 xig.xig_count = V_tcbinfo.ipi_count + 2709 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2710 error = SYSCTL_OUT(req, &xig, sizeof xig); 2711 } 2712 2713 return (error); 2714 } 2715 2716 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2717 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2718 NULL, 0, tcp_pcblist, "S,xtcpcb", 2719 "List of active TCP connections"); 2720 2721 #ifdef INET 2722 static int 2723 tcp_getcred(SYSCTL_HANDLER_ARGS) 2724 { 2725 struct xucred xuc; 2726 struct sockaddr_in addrs[2]; 2727 struct epoch_tracker et; 2728 struct inpcb *inp; 2729 int error; 2730 2731 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2732 if (error) 2733 return (error); 2734 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2735 if (error) 2736 return (error); 2737 NET_EPOCH_ENTER(et); 2738 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2739 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2740 NET_EPOCH_EXIT(et); 2741 if (inp != NULL) { 2742 if (inp->inp_socket == NULL) 2743 error = ENOENT; 2744 if (error == 0) 2745 error = cr_canseeinpcb(req->td->td_ucred, inp); 2746 if (error == 0) 2747 cru2x(inp->inp_cred, &xuc); 2748 INP_RUNLOCK(inp); 2749 } else 2750 error = ENOENT; 2751 if (error == 0) 2752 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2753 return (error); 2754 } 2755 2756 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2757 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2758 0, 0, tcp_getcred, "S,xucred", 2759 "Get the xucred of a TCP connection"); 2760 #endif /* INET */ 2761 2762 #ifdef INET6 2763 static int 2764 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2765 { 2766 struct epoch_tracker et; 2767 struct xucred xuc; 2768 struct sockaddr_in6 addrs[2]; 2769 struct inpcb *inp; 2770 int error; 2771 #ifdef INET 2772 int mapped = 0; 2773 #endif 2774 2775 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2776 if (error) 2777 return (error); 2778 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2779 if (error) 2780 return (error); 2781 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2782 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2783 return (error); 2784 } 2785 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2786 #ifdef INET 2787 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2788 mapped = 1; 2789 else 2790 #endif 2791 return (EINVAL); 2792 } 2793 2794 NET_EPOCH_ENTER(et); 2795 #ifdef INET 2796 if (mapped == 1) 2797 inp = in_pcblookup(&V_tcbinfo, 2798 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2799 addrs[1].sin6_port, 2800 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2801 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2802 else 2803 #endif 2804 inp = in6_pcblookup(&V_tcbinfo, 2805 &addrs[1].sin6_addr, addrs[1].sin6_port, 2806 &addrs[0].sin6_addr, addrs[0].sin6_port, 2807 INPLOOKUP_RLOCKPCB, NULL); 2808 NET_EPOCH_EXIT(et); 2809 if (inp != NULL) { 2810 if (inp->inp_socket == NULL) 2811 error = ENOENT; 2812 if (error == 0) 2813 error = cr_canseeinpcb(req->td->td_ucred, inp); 2814 if (error == 0) 2815 cru2x(inp->inp_cred, &xuc); 2816 INP_RUNLOCK(inp); 2817 } else 2818 error = ENOENT; 2819 if (error == 0) 2820 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2821 return (error); 2822 } 2823 2824 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2825 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2826 0, 0, tcp6_getcred, "S,xucred", 2827 "Get the xucred of a TCP6 connection"); 2828 #endif /* INET6 */ 2829 2830 #ifdef INET 2831 /* Path MTU to try next when a fragmentation-needed message is received. */ 2832 static inline int 2833 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2834 { 2835 int mtu = ntohs(icp->icmp_nextmtu); 2836 2837 /* If no alternative MTU was proposed, try the next smaller one. */ 2838 if (!mtu) 2839 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2840 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2841 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2842 2843 return (mtu); 2844 } 2845 2846 static void 2847 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2848 { 2849 struct ip *ip = vip; 2850 struct tcphdr *th; 2851 struct in_addr faddr; 2852 struct inpcb *inp; 2853 struct tcpcb *tp; 2854 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2855 struct icmp *icp; 2856 struct in_conninfo inc; 2857 tcp_seq icmp_tcp_seq; 2858 int mtu; 2859 2860 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2861 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2862 return; 2863 2864 if (cmd == PRC_MSGSIZE) 2865 notify = tcp_mtudisc_notify; 2866 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2867 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2868 cmd == PRC_TIMXCEED_INTRANS) && ip) 2869 notify = tcp_drop_syn_sent; 2870 2871 /* 2872 * Hostdead is ugly because it goes linearly through all PCBs. 2873 * XXX: We never get this from ICMP, otherwise it makes an 2874 * excellent DoS attack on machines with many connections. 2875 */ 2876 else if (cmd == PRC_HOSTDEAD) 2877 ip = NULL; 2878 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2879 return; 2880 2881 if (ip == NULL) { 2882 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2883 return; 2884 } 2885 2886 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2887 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2888 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2889 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2890 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2891 /* signal EHOSTDOWN, as it flushes the cached route */ 2892 inp = (*notify)(inp, EHOSTDOWN); 2893 goto out; 2894 } 2895 icmp_tcp_seq = th->th_seq; 2896 if (inp != NULL) { 2897 if (!(inp->inp_flags & INP_TIMEWAIT) && 2898 !(inp->inp_flags & INP_DROPPED) && 2899 !(inp->inp_socket == NULL)) { 2900 tp = intotcpcb(inp); 2901 #ifdef TCP_OFFLOAD 2902 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2903 /* 2904 * MTU discovery for offloaded connections. Let 2905 * the TOE driver verify seq# and process it. 2906 */ 2907 mtu = tcp_next_pmtu(icp, ip); 2908 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2909 goto out; 2910 } 2911 #endif 2912 if (tp->t_port != port) { 2913 goto out; 2914 } 2915 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2916 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2917 if (cmd == PRC_MSGSIZE) { 2918 /* 2919 * MTU discovery: we got a needfrag and 2920 * will potentially try a lower MTU. 2921 */ 2922 mtu = tcp_next_pmtu(icp, ip); 2923 2924 /* 2925 * Only process the offered MTU if it 2926 * is smaller than the current one. 2927 */ 2928 if (mtu < tp->t_maxseg + 2929 sizeof(struct tcpiphdr)) { 2930 bzero(&inc, sizeof(inc)); 2931 inc.inc_faddr = faddr; 2932 inc.inc_fibnum = 2933 inp->inp_inc.inc_fibnum; 2934 tcp_hc_updatemtu(&inc, mtu); 2935 tcp_mtudisc(inp, mtu); 2936 } 2937 } else 2938 inp = (*notify)(inp, 2939 inetctlerrmap[cmd]); 2940 } 2941 } 2942 } else { 2943 bzero(&inc, sizeof(inc)); 2944 inc.inc_fport = th->th_dport; 2945 inc.inc_lport = th->th_sport; 2946 inc.inc_faddr = faddr; 2947 inc.inc_laddr = ip->ip_src; 2948 syncache_unreach(&inc, icmp_tcp_seq, port); 2949 } 2950 out: 2951 if (inp != NULL) 2952 INP_WUNLOCK(inp); 2953 } 2954 2955 void 2956 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2957 { 2958 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2959 } 2960 2961 void 2962 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2963 { 2964 /* Its a tunneled TCP over UDP icmp */ 2965 struct ip *outer_ip, *inner_ip; 2966 struct icmp *icmp; 2967 struct udphdr *udp; 2968 struct tcphdr *th, ttemp; 2969 int i_hlen, o_len; 2970 uint16_t port; 2971 2972 inner_ip = (struct ip *)vip; 2973 icmp = (struct icmp *)((caddr_t)inner_ip - 2974 (sizeof(struct icmp) - sizeof(struct ip))); 2975 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2976 i_hlen = inner_ip->ip_hl << 2; 2977 o_len = ntohs(outer_ip->ip_len); 2978 if (o_len < 2979 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2980 /* Not enough data present */ 2981 return; 2982 } 2983 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2984 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2985 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2986 return; 2987 } 2988 port = udp->uh_dport; 2989 th = (struct tcphdr *)(udp + 1); 2990 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2991 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2992 /* Now adjust down the size of the outer IP header */ 2993 o_len -= sizeof(struct udphdr); 2994 outer_ip->ip_len = htons(o_len); 2995 /* Now call in to the normal handling code */ 2996 tcp_ctlinput_with_port(cmd, sa, vip, port); 2997 } 2998 #endif /* INET */ 2999 3000 #ifdef INET6 3001 static inline int 3002 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 3003 { 3004 int mtu = ntohl(icmp6->icmp6_mtu); 3005 3006 /* 3007 * If no alternative MTU was proposed, or the proposed MTU was too 3008 * small, set to the min. 3009 */ 3010 if (mtu < IPV6_MMTU) 3011 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3012 return (mtu); 3013 } 3014 3015 static void 3016 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3017 { 3018 struct in6_addr *dst; 3019 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3020 struct ip6_hdr *ip6; 3021 struct mbuf *m; 3022 struct inpcb *inp; 3023 struct tcpcb *tp; 3024 struct icmp6_hdr *icmp6; 3025 struct ip6ctlparam *ip6cp = NULL; 3026 const struct sockaddr_in6 *sa6_src = NULL; 3027 struct in_conninfo inc; 3028 struct tcp_ports { 3029 uint16_t th_sport; 3030 uint16_t th_dport; 3031 } t_ports; 3032 tcp_seq icmp_tcp_seq; 3033 unsigned int mtu; 3034 unsigned int off; 3035 3036 if (sa->sa_family != AF_INET6 || 3037 sa->sa_len != sizeof(struct sockaddr_in6)) 3038 return; 3039 3040 /* if the parameter is from icmp6, decode it. */ 3041 if (d != NULL) { 3042 ip6cp = (struct ip6ctlparam *)d; 3043 icmp6 = ip6cp->ip6c_icmp6; 3044 m = ip6cp->ip6c_m; 3045 ip6 = ip6cp->ip6c_ip6; 3046 off = ip6cp->ip6c_off; 3047 sa6_src = ip6cp->ip6c_src; 3048 dst = ip6cp->ip6c_finaldst; 3049 } else { 3050 m = NULL; 3051 ip6 = NULL; 3052 off = 0; /* fool gcc */ 3053 sa6_src = &sa6_any; 3054 dst = NULL; 3055 } 3056 3057 if (cmd == PRC_MSGSIZE) 3058 notify = tcp_mtudisc_notify; 3059 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3060 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3061 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3062 notify = tcp_drop_syn_sent; 3063 3064 /* 3065 * Hostdead is ugly because it goes linearly through all PCBs. 3066 * XXX: We never get this from ICMP, otherwise it makes an 3067 * excellent DoS attack on machines with many connections. 3068 */ 3069 else if (cmd == PRC_HOSTDEAD) 3070 ip6 = NULL; 3071 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3072 return; 3073 3074 if (ip6 == NULL) { 3075 in6_pcbnotify(&V_tcbinfo, sa, 0, 3076 (const struct sockaddr *)sa6_src, 3077 0, cmd, NULL, notify); 3078 return; 3079 } 3080 3081 /* Check if we can safely get the ports from the tcp hdr */ 3082 if (m == NULL || 3083 (m->m_pkthdr.len < 3084 (int32_t) (off + sizeof(struct tcp_ports)))) { 3085 return; 3086 } 3087 bzero(&t_ports, sizeof(struct tcp_ports)); 3088 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3089 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3090 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3091 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3092 /* signal EHOSTDOWN, as it flushes the cached route */ 3093 inp = (*notify)(inp, EHOSTDOWN); 3094 goto out; 3095 } 3096 off += sizeof(struct tcp_ports); 3097 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3098 goto out; 3099 } 3100 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3101 if (inp != NULL) { 3102 if (!(inp->inp_flags & INP_TIMEWAIT) && 3103 !(inp->inp_flags & INP_DROPPED) && 3104 !(inp->inp_socket == NULL)) { 3105 tp = intotcpcb(inp); 3106 #ifdef TCP_OFFLOAD 3107 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3108 /* MTU discovery for offloaded connections. */ 3109 mtu = tcp6_next_pmtu(icmp6); 3110 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3111 goto out; 3112 } 3113 #endif 3114 if (tp->t_port != port) { 3115 goto out; 3116 } 3117 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3118 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3119 if (cmd == PRC_MSGSIZE) { 3120 /* 3121 * MTU discovery: 3122 * If we got a needfrag set the MTU 3123 * in the route to the suggested new 3124 * value (if given) and then notify. 3125 */ 3126 mtu = tcp6_next_pmtu(icmp6); 3127 3128 bzero(&inc, sizeof(inc)); 3129 inc.inc_fibnum = M_GETFIB(m); 3130 inc.inc_flags |= INC_ISIPV6; 3131 inc.inc6_faddr = *dst; 3132 if (in6_setscope(&inc.inc6_faddr, 3133 m->m_pkthdr.rcvif, NULL)) 3134 goto out; 3135 /* 3136 * Only process the offered MTU if it 3137 * is smaller than the current one. 3138 */ 3139 if (mtu < tp->t_maxseg + 3140 sizeof (struct tcphdr) + 3141 sizeof (struct ip6_hdr)) { 3142 tcp_hc_updatemtu(&inc, mtu); 3143 tcp_mtudisc(inp, mtu); 3144 ICMP6STAT_INC(icp6s_pmtuchg); 3145 } 3146 } else 3147 inp = (*notify)(inp, 3148 inet6ctlerrmap[cmd]); 3149 } 3150 } 3151 } else { 3152 bzero(&inc, sizeof(inc)); 3153 inc.inc_fibnum = M_GETFIB(m); 3154 inc.inc_flags |= INC_ISIPV6; 3155 inc.inc_fport = t_ports.th_dport; 3156 inc.inc_lport = t_ports.th_sport; 3157 inc.inc6_faddr = *dst; 3158 inc.inc6_laddr = ip6->ip6_src; 3159 syncache_unreach(&inc, icmp_tcp_seq, port); 3160 } 3161 out: 3162 if (inp != NULL) 3163 INP_WUNLOCK(inp); 3164 } 3165 3166 void 3167 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3168 { 3169 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3170 } 3171 3172 void 3173 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3174 { 3175 struct ip6ctlparam *ip6cp; 3176 struct mbuf *m; 3177 struct udphdr *udp; 3178 uint16_t port; 3179 3180 ip6cp = (struct ip6ctlparam *)d; 3181 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3182 if (m == NULL) { 3183 return; 3184 } 3185 udp = mtod(m, struct udphdr *); 3186 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3187 return; 3188 } 3189 port = udp->uh_dport; 3190 m_adj(m, sizeof(struct udphdr)); 3191 if ((m->m_flags & M_PKTHDR) == 0) { 3192 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3193 } 3194 /* Now call in to the normal handling code */ 3195 tcp6_ctlinput_with_port(cmd, sa, d, port); 3196 } 3197 3198 #endif /* INET6 */ 3199 3200 static uint32_t 3201 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3202 { 3203 SIPHASH_CTX ctx; 3204 uint32_t hash[2]; 3205 3206 KASSERT(len >= SIPHASH_KEY_LENGTH, 3207 ("%s: keylen %u too short ", __func__, len)); 3208 SipHash24_Init(&ctx); 3209 SipHash_SetKey(&ctx, (uint8_t *)key); 3210 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3211 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3212 switch (inc->inc_flags & INC_ISIPV6) { 3213 #ifdef INET 3214 case 0: 3215 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3216 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3217 break; 3218 #endif 3219 #ifdef INET6 3220 case INC_ISIPV6: 3221 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3222 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3223 break; 3224 #endif 3225 } 3226 SipHash_Final((uint8_t *)hash, &ctx); 3227 3228 return (hash[0] ^ hash[1]); 3229 } 3230 3231 uint32_t 3232 tcp_new_ts_offset(struct in_conninfo *inc) 3233 { 3234 struct in_conninfo inc_store, *local_inc; 3235 3236 if (!V_tcp_ts_offset_per_conn) { 3237 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3238 inc_store.inc_lport = 0; 3239 inc_store.inc_fport = 0; 3240 local_inc = &inc_store; 3241 } else { 3242 local_inc = inc; 3243 } 3244 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3245 sizeof(V_ts_offset_secret))); 3246 } 3247 3248 /* 3249 * Following is where TCP initial sequence number generation occurs. 3250 * 3251 * There are two places where we must use initial sequence numbers: 3252 * 1. In SYN-ACK packets. 3253 * 2. In SYN packets. 3254 * 3255 * All ISNs for SYN-ACK packets are generated by the syncache. See 3256 * tcp_syncache.c for details. 3257 * 3258 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3259 * depends on this property. In addition, these ISNs should be 3260 * unguessable so as to prevent connection hijacking. To satisfy 3261 * the requirements of this situation, the algorithm outlined in 3262 * RFC 1948 is used, with only small modifications. 3263 * 3264 * Implementation details: 3265 * 3266 * Time is based off the system timer, and is corrected so that it 3267 * increases by one megabyte per second. This allows for proper 3268 * recycling on high speed LANs while still leaving over an hour 3269 * before rollover. 3270 * 3271 * As reading the *exact* system time is too expensive to be done 3272 * whenever setting up a TCP connection, we increment the time 3273 * offset in two ways. First, a small random positive increment 3274 * is added to isn_offset for each connection that is set up. 3275 * Second, the function tcp_isn_tick fires once per clock tick 3276 * and increments isn_offset as necessary so that sequence numbers 3277 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3278 * random positive increments serve only to ensure that the same 3279 * exact sequence number is never sent out twice (as could otherwise 3280 * happen when a port is recycled in less than the system tick 3281 * interval.) 3282 * 3283 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3284 * between seeding of isn_secret. This is normally set to zero, 3285 * as reseeding should not be necessary. 3286 * 3287 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3288 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3289 * general, this means holding an exclusive (write) lock. 3290 */ 3291 3292 #define ISN_BYTES_PER_SECOND 1048576 3293 #define ISN_STATIC_INCREMENT 4096 3294 #define ISN_RANDOM_INCREMENT (4096 - 1) 3295 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3296 3297 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3298 VNET_DEFINE_STATIC(int, isn_last); 3299 VNET_DEFINE_STATIC(int, isn_last_reseed); 3300 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3301 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3302 3303 #define V_isn_secret VNET(isn_secret) 3304 #define V_isn_last VNET(isn_last) 3305 #define V_isn_last_reseed VNET(isn_last_reseed) 3306 #define V_isn_offset VNET(isn_offset) 3307 #define V_isn_offset_old VNET(isn_offset_old) 3308 3309 tcp_seq 3310 tcp_new_isn(struct in_conninfo *inc) 3311 { 3312 tcp_seq new_isn; 3313 u_int32_t projected_offset; 3314 3315 ISN_LOCK(); 3316 /* Seed if this is the first use, reseed if requested. */ 3317 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3318 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3319 < (u_int)ticks))) { 3320 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3321 V_isn_last_reseed = ticks; 3322 } 3323 3324 /* Compute the hash and return the ISN. */ 3325 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3326 sizeof(V_isn_secret)); 3327 V_isn_offset += ISN_STATIC_INCREMENT + 3328 (arc4random() & ISN_RANDOM_INCREMENT); 3329 if (ticks != V_isn_last) { 3330 projected_offset = V_isn_offset_old + 3331 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3332 if (SEQ_GT(projected_offset, V_isn_offset)) 3333 V_isn_offset = projected_offset; 3334 V_isn_offset_old = V_isn_offset; 3335 V_isn_last = ticks; 3336 } 3337 new_isn += V_isn_offset; 3338 ISN_UNLOCK(); 3339 return (new_isn); 3340 } 3341 3342 /* 3343 * When a specific ICMP unreachable message is received and the 3344 * connection state is SYN-SENT, drop the connection. This behavior 3345 * is controlled by the icmp_may_rst sysctl. 3346 */ 3347 struct inpcb * 3348 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3349 { 3350 struct tcpcb *tp; 3351 3352 NET_EPOCH_ASSERT(); 3353 INP_WLOCK_ASSERT(inp); 3354 3355 if ((inp->inp_flags & INP_TIMEWAIT) || 3356 (inp->inp_flags & INP_DROPPED)) 3357 return (inp); 3358 3359 tp = intotcpcb(inp); 3360 if (tp->t_state != TCPS_SYN_SENT) 3361 return (inp); 3362 3363 if (IS_FASTOPEN(tp->t_flags)) 3364 tcp_fastopen_disable_path(tp); 3365 3366 tp = tcp_drop(tp, errno); 3367 if (tp != NULL) 3368 return (inp); 3369 else 3370 return (NULL); 3371 } 3372 3373 /* 3374 * When `need fragmentation' ICMP is received, update our idea of the MSS 3375 * based on the new value. Also nudge TCP to send something, since we 3376 * know the packet we just sent was dropped. 3377 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3378 */ 3379 static struct inpcb * 3380 tcp_mtudisc_notify(struct inpcb *inp, int error) 3381 { 3382 3383 tcp_mtudisc(inp, -1); 3384 return (inp); 3385 } 3386 3387 static void 3388 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3389 { 3390 struct tcpcb *tp; 3391 struct socket *so; 3392 3393 INP_WLOCK_ASSERT(inp); 3394 if ((inp->inp_flags & INP_TIMEWAIT) || 3395 (inp->inp_flags & INP_DROPPED)) 3396 return; 3397 3398 tp = intotcpcb(inp); 3399 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3400 3401 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3402 3403 so = inp->inp_socket; 3404 SOCKBUF_LOCK(&so->so_snd); 3405 /* If the mss is larger than the socket buffer, decrease the mss. */ 3406 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3407 tp->t_maxseg = so->so_snd.sb_hiwat; 3408 SOCKBUF_UNLOCK(&so->so_snd); 3409 3410 TCPSTAT_INC(tcps_mturesent); 3411 tp->t_rtttime = 0; 3412 tp->snd_nxt = tp->snd_una; 3413 tcp_free_sackholes(tp); 3414 tp->snd_recover = tp->snd_max; 3415 if (tp->t_flags & TF_SACK_PERMIT) 3416 EXIT_FASTRECOVERY(tp->t_flags); 3417 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3418 /* 3419 * Conceptually the snd_nxt setting 3420 * and freeing sack holes should 3421 * be done by the default stacks 3422 * own tfb_tcp_mtu_chg(). 3423 */ 3424 tp->t_fb->tfb_tcp_mtu_chg(tp); 3425 } 3426 tp->t_fb->tfb_tcp_output(tp); 3427 } 3428 3429 #ifdef INET 3430 /* 3431 * Look-up the routing entry to the peer of this inpcb. If no route 3432 * is found and it cannot be allocated, then return 0. This routine 3433 * is called by TCP routines that access the rmx structure and by 3434 * tcp_mss_update to get the peer/interface MTU. 3435 */ 3436 uint32_t 3437 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3438 { 3439 struct nhop_object *nh; 3440 struct ifnet *ifp; 3441 uint32_t maxmtu = 0; 3442 3443 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3444 3445 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3446 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3447 if (nh == NULL) 3448 return (0); 3449 3450 ifp = nh->nh_ifp; 3451 maxmtu = nh->nh_mtu; 3452 3453 /* Report additional interface capabilities. */ 3454 if (cap != NULL) { 3455 if (ifp->if_capenable & IFCAP_TSO4 && 3456 ifp->if_hwassist & CSUM_TSO) { 3457 cap->ifcap |= CSUM_TSO; 3458 cap->tsomax = ifp->if_hw_tsomax; 3459 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3460 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3461 } 3462 } 3463 } 3464 return (maxmtu); 3465 } 3466 #endif /* INET */ 3467 3468 #ifdef INET6 3469 uint32_t 3470 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3471 { 3472 struct nhop_object *nh; 3473 struct in6_addr dst6; 3474 uint32_t scopeid; 3475 struct ifnet *ifp; 3476 uint32_t maxmtu = 0; 3477 3478 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3479 3480 if (inc->inc_flags & INC_IPV6MINMTU) 3481 return (IPV6_MMTU); 3482 3483 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3484 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3485 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3486 if (nh == NULL) 3487 return (0); 3488 3489 ifp = nh->nh_ifp; 3490 maxmtu = nh->nh_mtu; 3491 3492 /* Report additional interface capabilities. */ 3493 if (cap != NULL) { 3494 if (ifp->if_capenable & IFCAP_TSO6 && 3495 ifp->if_hwassist & CSUM_TSO) { 3496 cap->ifcap |= CSUM_TSO; 3497 cap->tsomax = ifp->if_hw_tsomax; 3498 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3499 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3500 } 3501 } 3502 } 3503 3504 return (maxmtu); 3505 } 3506 #endif /* INET6 */ 3507 3508 /* 3509 * Calculate effective SMSS per RFC5681 definition for a given TCP 3510 * connection at its current state, taking into account SACK and etc. 3511 */ 3512 u_int 3513 tcp_maxseg(const struct tcpcb *tp) 3514 { 3515 u_int optlen; 3516 3517 if (tp->t_flags & TF_NOOPT) 3518 return (tp->t_maxseg); 3519 3520 /* 3521 * Here we have a simplified code from tcp_addoptions(), 3522 * without a proper loop, and having most of paddings hardcoded. 3523 * We might make mistakes with padding here in some edge cases, 3524 * but this is harmless, since result of tcp_maxseg() is used 3525 * only in cwnd and ssthresh estimations. 3526 */ 3527 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3528 if (tp->t_flags & TF_RCVD_TSTMP) 3529 optlen = TCPOLEN_TSTAMP_APPA; 3530 else 3531 optlen = 0; 3532 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3533 if (tp->t_flags & TF_SIGNATURE) 3534 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3535 #endif 3536 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3537 optlen += TCPOLEN_SACKHDR; 3538 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3539 optlen = PADTCPOLEN(optlen); 3540 } 3541 } else { 3542 if (tp->t_flags & TF_REQ_TSTMP) 3543 optlen = TCPOLEN_TSTAMP_APPA; 3544 else 3545 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3546 if (tp->t_flags & TF_REQ_SCALE) 3547 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3548 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3549 if (tp->t_flags & TF_SIGNATURE) 3550 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3551 #endif 3552 if (tp->t_flags & TF_SACK_PERMIT) 3553 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3554 } 3555 #undef PAD 3556 optlen = min(optlen, TCP_MAXOLEN); 3557 return (tp->t_maxseg - optlen); 3558 } 3559 3560 3561 u_int 3562 tcp_fixed_maxseg(const struct tcpcb *tp) 3563 { 3564 int optlen; 3565 3566 if (tp->t_flags & TF_NOOPT) 3567 return (tp->t_maxseg); 3568 3569 /* 3570 * Here we have a simplified code from tcp_addoptions(), 3571 * without a proper loop, and having most of paddings hardcoded. 3572 * We only consider fixed options that we would send every 3573 * time I.e. SACK is not considered. This is important 3574 * for cc modules to figure out what the modulo of the 3575 * cwnd should be. 3576 */ 3577 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3578 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3579 if (tp->t_flags & TF_RCVD_TSTMP) 3580 optlen = TCPOLEN_TSTAMP_APPA; 3581 else 3582 optlen = 0; 3583 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3584 if (tp->t_flags & TF_SIGNATURE) 3585 optlen += PAD(TCPOLEN_SIGNATURE); 3586 #endif 3587 } else { 3588 if (tp->t_flags & TF_REQ_TSTMP) 3589 optlen = TCPOLEN_TSTAMP_APPA; 3590 else 3591 optlen = PAD(TCPOLEN_MAXSEG); 3592 if (tp->t_flags & TF_REQ_SCALE) 3593 optlen += PAD(TCPOLEN_WINDOW); 3594 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3595 if (tp->t_flags & TF_SIGNATURE) 3596 optlen += PAD(TCPOLEN_SIGNATURE); 3597 #endif 3598 if (tp->t_flags & TF_SACK_PERMIT) 3599 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3600 } 3601 #undef PAD 3602 optlen = min(optlen, TCP_MAXOLEN); 3603 return (tp->t_maxseg - optlen); 3604 } 3605 3606 3607 3608 static int 3609 sysctl_drop(SYSCTL_HANDLER_ARGS) 3610 { 3611 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3612 struct sockaddr_storage addrs[2]; 3613 struct inpcb *inp; 3614 struct tcpcb *tp; 3615 struct tcptw *tw; 3616 struct sockaddr_in *fin, *lin; 3617 struct epoch_tracker et; 3618 #ifdef INET6 3619 struct sockaddr_in6 *fin6, *lin6; 3620 #endif 3621 int error; 3622 3623 inp = NULL; 3624 fin = lin = NULL; 3625 #ifdef INET6 3626 fin6 = lin6 = NULL; 3627 #endif 3628 error = 0; 3629 3630 if (req->oldptr != NULL || req->oldlen != 0) 3631 return (EINVAL); 3632 if (req->newptr == NULL) 3633 return (EPERM); 3634 if (req->newlen < sizeof(addrs)) 3635 return (ENOMEM); 3636 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3637 if (error) 3638 return (error); 3639 3640 switch (addrs[0].ss_family) { 3641 #ifdef INET6 3642 case AF_INET6: 3643 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3644 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3645 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3646 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3647 return (EINVAL); 3648 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3649 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3650 return (EINVAL); 3651 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3652 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3653 fin = (struct sockaddr_in *)&addrs[0]; 3654 lin = (struct sockaddr_in *)&addrs[1]; 3655 break; 3656 } 3657 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3658 if (error) 3659 return (error); 3660 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3661 if (error) 3662 return (error); 3663 break; 3664 #endif 3665 #ifdef INET 3666 case AF_INET: 3667 fin = (struct sockaddr_in *)&addrs[0]; 3668 lin = (struct sockaddr_in *)&addrs[1]; 3669 if (fin->sin_len != sizeof(struct sockaddr_in) || 3670 lin->sin_len != sizeof(struct sockaddr_in)) 3671 return (EINVAL); 3672 break; 3673 #endif 3674 default: 3675 return (EINVAL); 3676 } 3677 NET_EPOCH_ENTER(et); 3678 switch (addrs[0].ss_family) { 3679 #ifdef INET6 3680 case AF_INET6: 3681 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3682 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3683 INPLOOKUP_WLOCKPCB, NULL); 3684 break; 3685 #endif 3686 #ifdef INET 3687 case AF_INET: 3688 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3689 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3690 break; 3691 #endif 3692 } 3693 if (inp != NULL) { 3694 if (inp->inp_flags & INP_TIMEWAIT) { 3695 /* 3696 * XXXRW: There currently exists a state where an 3697 * inpcb is present, but its timewait state has been 3698 * discarded. For now, don't allow dropping of this 3699 * type of inpcb. 3700 */ 3701 tw = intotw(inp); 3702 if (tw != NULL) 3703 tcp_twclose(tw, 0); 3704 else 3705 INP_WUNLOCK(inp); 3706 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3707 !SOLISTENING(inp->inp_socket)) { 3708 tp = intotcpcb(inp); 3709 tp = tcp_drop(tp, ECONNABORTED); 3710 if (tp != NULL) 3711 INP_WUNLOCK(inp); 3712 } else 3713 INP_WUNLOCK(inp); 3714 } else 3715 error = ESRCH; 3716 NET_EPOCH_EXIT(et); 3717 return (error); 3718 } 3719 3720 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3721 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3722 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3723 "Drop TCP connection"); 3724 3725 #ifdef KERN_TLS 3726 static int 3727 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3728 { 3729 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3730 struct sockaddr_storage addrs[2]; 3731 struct inpcb *inp; 3732 struct sockaddr_in *fin, *lin; 3733 struct epoch_tracker et; 3734 #ifdef INET6 3735 struct sockaddr_in6 *fin6, *lin6; 3736 #endif 3737 int error; 3738 3739 inp = NULL; 3740 fin = lin = NULL; 3741 #ifdef INET6 3742 fin6 = lin6 = NULL; 3743 #endif 3744 error = 0; 3745 3746 if (req->oldptr != NULL || req->oldlen != 0) 3747 return (EINVAL); 3748 if (req->newptr == NULL) 3749 return (EPERM); 3750 if (req->newlen < sizeof(addrs)) 3751 return (ENOMEM); 3752 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3753 if (error) 3754 return (error); 3755 3756 switch (addrs[0].ss_family) { 3757 #ifdef INET6 3758 case AF_INET6: 3759 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3760 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3761 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3762 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3763 return (EINVAL); 3764 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3765 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3766 return (EINVAL); 3767 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3768 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3769 fin = (struct sockaddr_in *)&addrs[0]; 3770 lin = (struct sockaddr_in *)&addrs[1]; 3771 break; 3772 } 3773 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3774 if (error) 3775 return (error); 3776 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3777 if (error) 3778 return (error); 3779 break; 3780 #endif 3781 #ifdef INET 3782 case AF_INET: 3783 fin = (struct sockaddr_in *)&addrs[0]; 3784 lin = (struct sockaddr_in *)&addrs[1]; 3785 if (fin->sin_len != sizeof(struct sockaddr_in) || 3786 lin->sin_len != sizeof(struct sockaddr_in)) 3787 return (EINVAL); 3788 break; 3789 #endif 3790 default: 3791 return (EINVAL); 3792 } 3793 NET_EPOCH_ENTER(et); 3794 switch (addrs[0].ss_family) { 3795 #ifdef INET6 3796 case AF_INET6: 3797 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3798 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3799 INPLOOKUP_WLOCKPCB, NULL); 3800 break; 3801 #endif 3802 #ifdef INET 3803 case AF_INET: 3804 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3805 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3806 break; 3807 #endif 3808 } 3809 NET_EPOCH_EXIT(et); 3810 if (inp != NULL) { 3811 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3812 inp->inp_socket == NULL) { 3813 error = ECONNRESET; 3814 INP_WUNLOCK(inp); 3815 } else { 3816 struct socket *so; 3817 3818 so = inp->inp_socket; 3819 soref(so); 3820 error = ktls_set_tx_mode(so, 3821 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3822 INP_WUNLOCK(inp); 3823 SOCK_LOCK(so); 3824 sorele(so); 3825 } 3826 } else 3827 error = ESRCH; 3828 return (error); 3829 } 3830 3831 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3832 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3833 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3834 "Switch TCP connection to SW TLS"); 3835 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3836 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3837 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3838 "Switch TCP connection to ifnet TLS"); 3839 #endif 3840 3841 /* 3842 * Generate a standardized TCP log line for use throughout the 3843 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3844 * allow use in the interrupt context. 3845 * 3846 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3847 * NB: The function may return NULL if memory allocation failed. 3848 * 3849 * Due to header inclusion and ordering limitations the struct ip 3850 * and ip6_hdr pointers have to be passed as void pointers. 3851 */ 3852 char * 3853 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3854 const void *ip6hdr) 3855 { 3856 3857 /* Is logging enabled? */ 3858 if (V_tcp_log_in_vain == 0) 3859 return (NULL); 3860 3861 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3862 } 3863 3864 char * 3865 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3866 const void *ip6hdr) 3867 { 3868 3869 /* Is logging enabled? */ 3870 if (tcp_log_debug == 0) 3871 return (NULL); 3872 3873 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3874 } 3875 3876 static char * 3877 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3878 const void *ip6hdr) 3879 { 3880 char *s, *sp; 3881 size_t size; 3882 struct ip *ip; 3883 #ifdef INET6 3884 const struct ip6_hdr *ip6; 3885 3886 ip6 = (const struct ip6_hdr *)ip6hdr; 3887 #endif /* INET6 */ 3888 ip = (struct ip *)ip4hdr; 3889 3890 /* 3891 * The log line looks like this: 3892 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3893 */ 3894 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3895 sizeof(PRINT_TH_FLAGS) + 1 + 3896 #ifdef INET6 3897 2 * INET6_ADDRSTRLEN; 3898 #else 3899 2 * INET_ADDRSTRLEN; 3900 #endif /* INET6 */ 3901 3902 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3903 if (s == NULL) 3904 return (NULL); 3905 3906 strcat(s, "TCP: ["); 3907 sp = s + strlen(s); 3908 3909 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3910 inet_ntoa_r(inc->inc_faddr, sp); 3911 sp = s + strlen(s); 3912 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3913 sp = s + strlen(s); 3914 inet_ntoa_r(inc->inc_laddr, sp); 3915 sp = s + strlen(s); 3916 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3917 #ifdef INET6 3918 } else if (inc) { 3919 ip6_sprintf(sp, &inc->inc6_faddr); 3920 sp = s + strlen(s); 3921 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3922 sp = s + strlen(s); 3923 ip6_sprintf(sp, &inc->inc6_laddr); 3924 sp = s + strlen(s); 3925 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3926 } else if (ip6 && th) { 3927 ip6_sprintf(sp, &ip6->ip6_src); 3928 sp = s + strlen(s); 3929 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3930 sp = s + strlen(s); 3931 ip6_sprintf(sp, &ip6->ip6_dst); 3932 sp = s + strlen(s); 3933 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3934 #endif /* INET6 */ 3935 #ifdef INET 3936 } else if (ip && th) { 3937 inet_ntoa_r(ip->ip_src, sp); 3938 sp = s + strlen(s); 3939 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3940 sp = s + strlen(s); 3941 inet_ntoa_r(ip->ip_dst, sp); 3942 sp = s + strlen(s); 3943 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3944 #endif /* INET */ 3945 } else { 3946 free(s, M_TCPLOG); 3947 return (NULL); 3948 } 3949 sp = s + strlen(s); 3950 if (th) 3951 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3952 if (*(s + size - 1) != '\0') 3953 panic("%s: string too long", __func__); 3954 return (s); 3955 } 3956 3957 /* 3958 * A subroutine which makes it easy to track TCP state changes with DTrace. 3959 * This function shouldn't be called for t_state initializations that don't 3960 * correspond to actual TCP state transitions. 3961 */ 3962 void 3963 tcp_state_change(struct tcpcb *tp, int newstate) 3964 { 3965 #if defined(KDTRACE_HOOKS) 3966 int pstate = tp->t_state; 3967 #endif 3968 3969 TCPSTATES_DEC(tp->t_state); 3970 TCPSTATES_INC(newstate); 3971 tp->t_state = newstate; 3972 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3973 } 3974 3975 /* 3976 * Create an external-format (``xtcpcb'') structure using the information in 3977 * the kernel-format tcpcb structure pointed to by tp. This is done to 3978 * reduce the spew of irrelevant information over this interface, to isolate 3979 * user code from changes in the kernel structure, and potentially to provide 3980 * information-hiding if we decide that some of this information should be 3981 * hidden from users. 3982 */ 3983 void 3984 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3985 { 3986 struct tcpcb *tp = intotcpcb(inp); 3987 struct tcptw *tw = intotw(inp); 3988 sbintime_t now; 3989 3990 bzero(xt, sizeof(*xt)); 3991 if (inp->inp_flags & INP_TIMEWAIT) { 3992 xt->t_state = TCPS_TIME_WAIT; 3993 xt->xt_encaps_port = tw->t_port; 3994 } else { 3995 xt->t_state = tp->t_state; 3996 xt->t_logstate = tp->t_logstate; 3997 xt->t_flags = tp->t_flags; 3998 xt->t_sndzerowin = tp->t_sndzerowin; 3999 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4000 xt->t_rcvoopack = tp->t_rcvoopack; 4001 xt->t_rcv_wnd = tp->rcv_wnd; 4002 xt->t_snd_wnd = tp->snd_wnd; 4003 xt->t_snd_cwnd = tp->snd_cwnd; 4004 xt->t_snd_ssthresh = tp->snd_ssthresh; 4005 xt->t_maxseg = tp->t_maxseg; 4006 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4007 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4008 4009 now = getsbinuptime(); 4010 #define COPYTIMER(ttt) do { \ 4011 if (callout_active(&tp->t_timers->ttt)) \ 4012 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4013 SBT_1MS; \ 4014 else \ 4015 xt->ttt = 0; \ 4016 } while (0) 4017 COPYTIMER(tt_delack); 4018 COPYTIMER(tt_rexmt); 4019 COPYTIMER(tt_persist); 4020 COPYTIMER(tt_keep); 4021 COPYTIMER(tt_2msl); 4022 #undef COPYTIMER 4023 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4024 4025 xt->xt_encaps_port = tp->t_port; 4026 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4027 TCP_FUNCTION_NAME_LEN_MAX); 4028 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4029 TCP_CA_NAME_MAX); 4030 #ifdef TCP_BLACKBOX 4031 (void)tcp_log_get_id(tp, xt->xt_logid); 4032 #endif 4033 } 4034 4035 xt->xt_len = sizeof(struct xtcpcb); 4036 in_pcbtoxinpcb(inp, &xt->xt_inp); 4037 if (inp->inp_socket == NULL) 4038 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4039 } 4040 4041 void 4042 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4043 { 4044 uint32_t bit, i; 4045 4046 if ((tp == NULL) || 4047 (status > TCP_EI_STATUS_MAX_VALUE) || 4048 (status == 0)) { 4049 /* Invalid */ 4050 return; 4051 } 4052 if (status > (sizeof(uint32_t) * 8)) { 4053 /* Should this be a KASSERT? */ 4054 return; 4055 } 4056 bit = 1U << (status - 1); 4057 if (bit & tp->t_end_info_status) { 4058 /* already logged */ 4059 return; 4060 } 4061 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4062 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4063 tp->t_end_info_bytes[i] = status; 4064 tp->t_end_info_status |= bit; 4065 break; 4066 } 4067 } 4068 } 4069 4070 int 4071 tcp_can_enable_pacing(void) 4072 { 4073 4074 if ((tcp_pacing_limit == -1) || 4075 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4076 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4077 shadow_num_connections = number_of_tcp_connections_pacing; 4078 return (1); 4079 } else { 4080 return (0); 4081 } 4082 } 4083 4084 static uint8_t tcp_pacing_warning = 0; 4085 4086 void 4087 tcp_decrement_paced_conn(void) 4088 { 4089 uint32_t ret; 4090 4091 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4092 shadow_num_connections = number_of_tcp_connections_pacing; 4093 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4094 if (ret == 0) { 4095 if (tcp_pacing_limit != -1) { 4096 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4097 tcp_pacing_limit = 0; 4098 } else if (tcp_pacing_warning == 0) { 4099 printf("Warning pacing count is invalid, invalid decrement\n"); 4100 tcp_pacing_warning = 1; 4101 } 4102 } 4103 } 4104