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