1/*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/10/sys/netinet/tcp_subr.c 314667 2017-03-04 13:03:31Z avg $"); 34 35#include "opt_compat.h" 36#include "opt_inet.h" 37#include "opt_inet6.h" 38#include "opt_ipsec.h" 39#include "opt_kdtrace.h" 40#include "opt_tcpdebug.h" 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/callout.h> 45#include <sys/hhook.h> 46#include <sys/kernel.h> 47#include <sys/khelp.h> 48#include <sys/sysctl.h> 49#include <sys/jail.h> 50#include <sys/malloc.h> 51#include <sys/mbuf.h> 52#ifdef INET6 53#include <sys/domain.h> 54#endif 55#include <sys/priv.h> 56#include <sys/proc.h> 57#include <sys/sdt.h> 58#include <sys/socket.h> 59#include <sys/socketvar.h> 60#include <sys/protosw.h> 61#include <sys/random.h> 62 63#include <vm/uma.h> 64 65#include <net/route.h> 66#include <net/if.h> 67#include <net/vnet.h> 68 69#include <netinet/cc.h> 70#include <netinet/in.h> 71#include <netinet/in_kdtrace.h> 72#include <netinet/in_pcb.h> 73#include <netinet/in_systm.h> 74#include <netinet/in_var.h> 75#include <netinet/ip.h> 76#include <netinet/ip_icmp.h> 77#include <netinet/ip_var.h> 78#ifdef INET6 79#include <netinet/ip6.h> 80#include <netinet6/in6_pcb.h> 81#include <netinet6/ip6_var.h> 82#include <netinet6/scope6_var.h> 83#include <netinet6/nd6.h> 84#endif 85 86#ifdef TCP_RFC7413 87#include <netinet/tcp_fastopen.h> 88#endif 89#include <netinet/tcp_fsm.h> 90#include <netinet/tcp_seq.h> 91#include <netinet/tcp_timer.h> 92#include <netinet/tcp_var.h> 93#include <netinet/tcp_syncache.h> 94#ifdef INET6 95#include <netinet6/tcp6_var.h> 96#endif 97#include <netinet/tcpip.h> 98#ifdef TCPDEBUG 99#include <netinet/tcp_debug.h> 100#endif 101#ifdef INET6 102#include <netinet6/ip6protosw.h> 103#endif 104#ifdef TCP_OFFLOAD 105#include <netinet/tcp_offload.h> 106#endif 107 108#ifdef IPSEC 109#include <netipsec/ipsec.h> 110#include <netipsec/xform.h> 111#ifdef INET6 112#include <netipsec/ipsec6.h> 113#endif 114#include <netipsec/key.h> 115#include <sys/syslog.h> 116#endif /*IPSEC*/ 117 118#include <machine/in_cksum.h> 119#include <sys/md5.h> 120 121#include <security/mac/mac_framework.h> 122 123VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 124#ifdef INET6 125VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 126#endif 127 128static int 129sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 130{ 131 int error, new; 132 133 new = V_tcp_mssdflt; 134 error = sysctl_handle_int(oidp, &new, 0, req); 135 if (error == 0 && req->newptr) { 136 if (new < TCP_MINMSS) 137 error = EINVAL; 138 else 139 V_tcp_mssdflt = new; 140 } 141 return (error); 142} 143 144SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 145 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 146 &sysctl_net_inet_tcp_mss_check, "I", 147 "Default TCP Maximum Segment Size"); 148 149#ifdef INET6 150static int 151sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 152{ 153 int error, new; 154 155 new = V_tcp_v6mssdflt; 156 error = sysctl_handle_int(oidp, &new, 0, req); 157 if (error == 0 && req->newptr) { 158 if (new < TCP_MINMSS) 159 error = EINVAL; 160 else 161 V_tcp_v6mssdflt = new; 162 } 163 return (error); 164} 165 166SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 167 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 168 &sysctl_net_inet_tcp_mss_v6_check, "I", 169 "Default TCP Maximum Segment Size for IPv6"); 170#endif /* INET6 */ 171 172/* 173 * Minimum MSS we accept and use. This prevents DoS attacks where 174 * we are forced to a ridiculous low MSS like 20 and send hundreds 175 * of packets instead of one. The effect scales with the available 176 * bandwidth and quickly saturates the CPU and network interface 177 * with packet generation and sending. Set to zero to disable MINMSS 178 * checking. This setting prevents us from sending too small packets. 179 */ 180VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 181SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 182 &VNET_NAME(tcp_minmss), 0, 183 "Minimum TCP Maximum Segment Size"); 184 185VNET_DEFINE(int, tcp_do_rfc1323) = 1; 186SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 187 &VNET_NAME(tcp_do_rfc1323), 0, 188 "Enable rfc1323 (high performance TCP) extensions"); 189 190static int tcp_log_debug = 0; 191SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 192 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 193 194static int tcp_tcbhashsize = 0; 195SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 196 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 197 198static int do_tcpdrain = 1; 199SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 200 "Enable tcp_drain routine for extra help when low on mbufs"); 201 202SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 203 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 204 205static VNET_DEFINE(int, icmp_may_rst) = 1; 206#define V_icmp_may_rst VNET(icmp_may_rst) 207SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, 208 &VNET_NAME(icmp_may_rst), 0, 209 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 210 211static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 212#define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 213SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 214 &VNET_NAME(tcp_isn_reseed_interval), 0, 215 "Seconds between reseeding of ISN secret"); 216 217static int tcp_soreceive_stream = 0; 218SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 219 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 220 221#ifdef TCP_SIGNATURE 222static int tcp_sig_checksigs = 1; 223SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 224 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 225#endif 226 227VNET_DEFINE(uma_zone_t, sack_hole_zone); 228#define V_sack_hole_zone VNET(sack_hole_zone) 229 230VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 231 232static struct inpcb *tcp_notify(struct inpcb *, int); 233static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 234static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 235 void *ip4hdr, const void *ip6hdr); 236static void tcp_timer_discard(struct tcpcb *, uint32_t); 237 238/* 239 * Target size of TCP PCB hash tables. Must be a power of two. 240 * 241 * Note that this can be overridden by the kernel environment 242 * variable net.inet.tcp.tcbhashsize 243 */ 244#ifndef TCBHASHSIZE 245#define TCBHASHSIZE 0 246#endif 247 248/* 249 * XXX 250 * Callouts should be moved into struct tcp directly. They are currently 251 * separate because the tcpcb structure is exported to userland for sysctl 252 * parsing purposes, which do not know about callouts. 253 */ 254struct tcpcb_mem { 255 struct tcpcb tcb; 256 struct tcp_timer tt; 257 struct cc_var ccv; 258 struct osd osd; 259}; 260 261static VNET_DEFINE(uma_zone_t, tcpcb_zone); 262#define V_tcpcb_zone VNET(tcpcb_zone) 263 264MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 265static struct mtx isn_mtx; 266 267#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 268#define ISN_LOCK() mtx_lock(&isn_mtx) 269#define ISN_UNLOCK() mtx_unlock(&isn_mtx) 270 271/* 272 * TCP initialization. 273 */ 274static void 275tcp_zone_change(void *tag) 276{ 277 278 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 279 uma_zone_set_max(V_tcpcb_zone, maxsockets); 280 tcp_tw_zone_change(); 281} 282 283static int 284tcp_inpcb_init(void *mem, int size, int flags) 285{ 286 struct inpcb *inp = mem; 287 288 INP_LOCK_INIT(inp, "inp", "tcpinp"); 289 return (0); 290} 291 292/* 293 * Take a value and get the next power of 2 that doesn't overflow. 294 * Used to size the tcp_inpcb hash buckets. 295 */ 296static int 297maketcp_hashsize(int size) 298{ 299 int hashsize; 300 301 /* 302 * auto tune. 303 * get the next power of 2 higher than maxsockets. 304 */ 305 hashsize = 1 << fls(size); 306 /* catch overflow, and just go one power of 2 smaller */ 307 if (hashsize < size) { 308 hashsize = 1 << (fls(size) - 1); 309 } 310 return (hashsize); 311} 312 313void 314tcp_init(void) 315{ 316 const char *tcbhash_tuneable; 317 int hashsize; 318 319 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 320 321 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 322 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 323 printf("%s: WARNING: unable to register helper hook\n", __func__); 324 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 325 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 326 printf("%s: WARNING: unable to register helper hook\n", __func__); 327 328 hashsize = TCBHASHSIZE; 329 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 330 if (hashsize == 0) { 331 /* 332 * Auto tune the hash size based on maxsockets. 333 * A perfect hash would have a 1:1 mapping 334 * (hashsize = maxsockets) however it's been 335 * suggested that O(2) average is better. 336 */ 337 hashsize = maketcp_hashsize(maxsockets / 4); 338 /* 339 * Our historical default is 512, 340 * do not autotune lower than this. 341 */ 342 if (hashsize < 512) 343 hashsize = 512; 344 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 345 printf("%s: %s auto tuned to %d\n", __func__, 346 tcbhash_tuneable, hashsize); 347 } 348 /* 349 * We require a hashsize to be a power of two. 350 * Previously if it was not a power of two we would just reset it 351 * back to 512, which could be a nasty surprise if you did not notice 352 * the error message. 353 * Instead what we do is clip it to the closest power of two lower 354 * than the specified hash value. 355 */ 356 if (!powerof2(hashsize)) { 357 int oldhashsize = hashsize; 358 359 hashsize = maketcp_hashsize(hashsize); 360 /* prevent absurdly low value */ 361 if (hashsize < 16) 362 hashsize = 16; 363 printf("%s: WARNING: TCB hash size not a power of 2, " 364 "clipped from %d to %d.\n", __func__, oldhashsize, 365 hashsize); 366 } 367 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 368 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 369 IPI_HASHFIELDS_4TUPLE); 370 371 /* 372 * These have to be type stable for the benefit of the timers. 373 */ 374 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 375 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 376 uma_zone_set_max(V_tcpcb_zone, maxsockets); 377 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 378 379 tcp_tw_init(); 380 syncache_init(); 381 tcp_hc_init(); 382 383 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 384 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 385 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 386 387 /* Skip initialization of globals for non-default instances. */ 388 if (!IS_DEFAULT_VNET(curvnet)) 389 return; 390 391 tcp_reass_global_init(); 392 393 /* XXX virtualize those bellow? */ 394 tcp_delacktime = TCPTV_DELACK; 395 tcp_keepinit = TCPTV_KEEP_INIT; 396 tcp_keepidle = TCPTV_KEEP_IDLE; 397 tcp_keepintvl = TCPTV_KEEPINTVL; 398 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 399 tcp_msl = TCPTV_MSL; 400 tcp_rexmit_min = TCPTV_MIN; 401 if (tcp_rexmit_min < 1) 402 tcp_rexmit_min = 1; 403 tcp_persmin = TCPTV_PERSMIN; 404 tcp_persmax = TCPTV_PERSMAX; 405 tcp_rexmit_slop = TCPTV_CPU_VAR; 406 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 407 tcp_tcbhashsize = hashsize; 408 409 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 410 if (tcp_soreceive_stream) { 411#ifdef INET 412 tcp_usrreqs.pru_soreceive = soreceive_stream; 413#endif 414#ifdef INET6 415 tcp6_usrreqs.pru_soreceive = soreceive_stream; 416#endif /* INET6 */ 417 } 418 419#ifdef INET6 420#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 421#else /* INET6 */ 422#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 423#endif /* INET6 */ 424 if (max_protohdr < TCP_MINPROTOHDR) 425 max_protohdr = TCP_MINPROTOHDR; 426 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 427 panic("tcp_init"); 428#undef TCP_MINPROTOHDR 429 430 ISN_LOCK_INIT(); 431 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 432 SHUTDOWN_PRI_DEFAULT); 433 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 434 EVENTHANDLER_PRI_ANY); 435 436#ifdef TCP_RFC7413 437 tcp_fastopen_init(); 438#endif 439} 440 441#ifdef VIMAGE 442void 443tcp_destroy(void) 444{ 445 446#ifdef TCP_RFC7413 447 tcp_fastopen_destroy(); 448#endif 449 tcp_hc_destroy(); 450 syncache_destroy(); 451 tcp_tw_destroy(); 452 in_pcbinfo_destroy(&V_tcbinfo); 453 uma_zdestroy(V_sack_hole_zone); 454 uma_zdestroy(V_tcpcb_zone); 455} 456#endif 457 458void 459tcp_fini(void *xtp) 460{ 461 462} 463 464/* 465 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 466 * tcp_template used to store this data in mbufs, but we now recopy it out 467 * of the tcpcb each time to conserve mbufs. 468 */ 469void 470tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 471{ 472 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 473 474 INP_WLOCK_ASSERT(inp); 475 476#ifdef INET6 477 if ((inp->inp_vflag & INP_IPV6) != 0) { 478 struct ip6_hdr *ip6; 479 480 ip6 = (struct ip6_hdr *)ip_ptr; 481 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 482 (inp->inp_flow & IPV6_FLOWINFO_MASK); 483 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 484 (IPV6_VERSION & IPV6_VERSION_MASK); 485 ip6->ip6_nxt = IPPROTO_TCP; 486 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 487 ip6->ip6_src = inp->in6p_laddr; 488 ip6->ip6_dst = inp->in6p_faddr; 489 } 490#endif /* INET6 */ 491#if defined(INET6) && defined(INET) 492 else 493#endif 494#ifdef INET 495 { 496 struct ip *ip; 497 498 ip = (struct ip *)ip_ptr; 499 ip->ip_v = IPVERSION; 500 ip->ip_hl = 5; 501 ip->ip_tos = inp->inp_ip_tos; 502 ip->ip_len = 0; 503 ip->ip_id = 0; 504 ip->ip_off = 0; 505 ip->ip_ttl = inp->inp_ip_ttl; 506 ip->ip_sum = 0; 507 ip->ip_p = IPPROTO_TCP; 508 ip->ip_src = inp->inp_laddr; 509 ip->ip_dst = inp->inp_faddr; 510 } 511#endif /* INET */ 512 th->th_sport = inp->inp_lport; 513 th->th_dport = inp->inp_fport; 514 th->th_seq = 0; 515 th->th_ack = 0; 516 th->th_x2 = 0; 517 th->th_off = 5; 518 th->th_flags = 0; 519 th->th_win = 0; 520 th->th_urp = 0; 521 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 522} 523 524/* 525 * Create template to be used to send tcp packets on a connection. 526 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 527 * use for this function is in keepalives, which use tcp_respond. 528 */ 529struct tcptemp * 530tcpip_maketemplate(struct inpcb *inp) 531{ 532 struct tcptemp *t; 533 534 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 535 if (t == NULL) 536 return (NULL); 537 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 538 return (t); 539} 540 541/* 542 * Send a single message to the TCP at address specified by 543 * the given TCP/IP header. If m == NULL, then we make a copy 544 * of the tcpiphdr at ti and send directly to the addressed host. 545 * This is used to force keep alive messages out using the TCP 546 * template for a connection. If flags are given then we send 547 * a message back to the TCP which originated the * segment ti, 548 * and discard the mbuf containing it and any other attached mbufs. 549 * 550 * In any case the ack and sequence number of the transmitted 551 * segment are as specified by the parameters. 552 * 553 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 554 */ 555void 556tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 557 tcp_seq ack, tcp_seq seq, int flags) 558{ 559 struct tcpopt to; 560 struct inpcb *inp; 561 struct ip *ip; 562 struct mbuf *optm; 563 struct tcphdr *nth; 564 u_char *optp; 565#ifdef INET6 566 struct ip6_hdr *ip6; 567 int isipv6; 568#endif /* INET6 */ 569 int optlen, tlen, win; 570 bool incl_opts; 571 572 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 573 574#ifdef INET6 575 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 576 ip6 = ipgen; 577#endif /* INET6 */ 578 ip = ipgen; 579 580 if (tp != NULL) { 581 inp = tp->t_inpcb; 582 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 583 INP_WLOCK_ASSERT(inp); 584 } else 585 inp = NULL; 586 587 incl_opts = false; 588 win = 0; 589 if (tp != NULL) { 590 if (!(flags & TH_RST)) { 591 win = sbspace(&inp->inp_socket->so_rcv); 592 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 593 win = (long)TCP_MAXWIN << tp->rcv_scale; 594 } 595 if ((tp->t_flags & TF_NOOPT) == 0) 596 incl_opts = true; 597 } 598 if (m == NULL) { 599 m = m_gethdr(M_NOWAIT, MT_DATA); 600 if (m == NULL) 601 return; 602 m->m_data += max_linkhdr; 603#ifdef INET6 604 if (isipv6) { 605 bcopy((caddr_t)ip6, mtod(m, caddr_t), 606 sizeof(struct ip6_hdr)); 607 ip6 = mtod(m, struct ip6_hdr *); 608 nth = (struct tcphdr *)(ip6 + 1); 609 } else 610#endif /* INET6 */ 611 { 612 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 613 ip = mtod(m, struct ip *); 614 nth = (struct tcphdr *)(ip + 1); 615 } 616 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 617 flags = TH_ACK; 618 } else if (!M_WRITABLE(m)) { 619 struct mbuf *n; 620 621 /* Can't reuse 'm', allocate a new mbuf. */ 622 n = m_gethdr(M_NOWAIT, MT_DATA); 623 if (n == NULL) { 624 m_freem(m); 625 return; 626 } 627 628 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 629 m_freem(m); 630 m_freem(n); 631 return; 632 } 633 634 n->m_data += max_linkhdr; 635 /* m_len is set later */ 636#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 637#ifdef INET6 638 if (isipv6) { 639 bcopy((caddr_t)ip6, mtod(n, caddr_t), 640 sizeof(struct ip6_hdr)); 641 ip6 = mtod(n, struct ip6_hdr *); 642 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 643 nth = (struct tcphdr *)(ip6 + 1); 644 } else 645#endif /* INET6 */ 646 { 647 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 648 ip = mtod(n, struct ip *); 649 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 650 nth = (struct tcphdr *)(ip + 1); 651 } 652 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 653 xchg(nth->th_dport, nth->th_sport, uint16_t); 654 th = nth; 655 m_freem(m); 656 m = n; 657 } else { 658 /* 659 * reuse the mbuf. 660 * XXX MRT We inherit the FIB, which is lucky. 661 */ 662 m_freem(m->m_next); 663 m->m_next = NULL; 664 m->m_data = (caddr_t)ipgen; 665 /* m_len is set later */ 666#ifdef INET6 667 if (isipv6) { 668 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 669 nth = (struct tcphdr *)(ip6 + 1); 670 } else 671#endif /* INET6 */ 672 { 673 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 674 nth = (struct tcphdr *)(ip + 1); 675 } 676 if (th != nth) { 677 /* 678 * this is usually a case when an extension header 679 * exists between the IPv6 header and the 680 * TCP header. 681 */ 682 nth->th_sport = th->th_sport; 683 nth->th_dport = th->th_dport; 684 } 685 xchg(nth->th_dport, nth->th_sport, uint16_t); 686#undef xchg 687 } 688 tlen = 0; 689#ifdef INET6 690 if (isipv6) 691 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 692#endif 693#if defined(INET) && defined(INET6) 694 else 695#endif 696#ifdef INET 697 tlen = sizeof (struct tcpiphdr); 698#endif 699#ifdef INVARIANTS 700 m->m_len = 0; 701 KASSERT(M_TRAILINGSPACE(m) >= tlen, 702 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 703 m, tlen, (long)M_TRAILINGSPACE(m))); 704#endif 705 m->m_len = tlen; 706 to.to_flags = 0; 707 if (incl_opts) { 708 /* Make sure we have room. */ 709 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 710 m->m_next = m_get(M_NOWAIT, MT_DATA); 711 if (m->m_next) { 712 optp = mtod(m->m_next, u_char *); 713 optm = m->m_next; 714 } else 715 incl_opts = false; 716 } else { 717 optp = (u_char *) (nth + 1); 718 optm = m; 719 } 720 } 721 if (incl_opts) { 722 /* Timestamps. */ 723 if (tp->t_flags & TF_RCVD_TSTMP) { 724 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 725 to.to_tsecr = tp->ts_recent; 726 to.to_flags |= TOF_TS; 727 } 728#ifdef TCP_SIGNATURE 729 /* TCP-MD5 (RFC2385). */ 730 if (tp->t_flags & TF_SIGNATURE) 731 to.to_flags |= TOF_SIGNATURE; 732#endif 733 734 /* Add the options. */ 735 tlen += optlen = tcp_addoptions(&to, optp); 736 737 /* Update m_len in the correct mbuf. */ 738 optm->m_len += optlen; 739 } else 740 optlen = 0; 741#ifdef INET6 742 if (isipv6) { 743 ip6->ip6_flow = 0; 744 ip6->ip6_vfc = IPV6_VERSION; 745 ip6->ip6_nxt = IPPROTO_TCP; 746 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 747 } 748#endif 749#if defined(INET) && defined(INET6) 750 else 751#endif 752#ifdef INET 753 { 754 ip->ip_len = htons(tlen); 755 ip->ip_ttl = V_ip_defttl; 756 if (V_path_mtu_discovery) 757 ip->ip_off |= htons(IP_DF); 758 } 759#endif 760 m->m_pkthdr.len = tlen; 761 m->m_pkthdr.rcvif = NULL; 762#ifdef MAC 763 if (inp != NULL) { 764 /* 765 * Packet is associated with a socket, so allow the 766 * label of the response to reflect the socket label. 767 */ 768 INP_WLOCK_ASSERT(inp); 769 mac_inpcb_create_mbuf(inp, m); 770 } else { 771 /* 772 * Packet is not associated with a socket, so possibly 773 * update the label in place. 774 */ 775 mac_netinet_tcp_reply(m); 776 } 777#endif 778 nth->th_seq = htonl(seq); 779 nth->th_ack = htonl(ack); 780 nth->th_x2 = 0; 781 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 782 nth->th_flags = flags; 783 if (tp != NULL) 784 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 785 else 786 nth->th_win = htons((u_short)win); 787 nth->th_urp = 0; 788 789#ifdef TCP_SIGNATURE 790 if (to.to_flags & TOF_SIGNATURE) { 791 tcp_signature_compute(m, 0, 0, optlen, to.to_signature, 792 IPSEC_DIR_OUTBOUND); 793 } 794#endif 795 796 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 797#ifdef INET6 798 if (isipv6) { 799 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 800 nth->th_sum = in6_cksum_pseudo(ip6, 801 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 802 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 803 NULL, NULL); 804 } 805#endif /* INET6 */ 806#if defined(INET6) && defined(INET) 807 else 808#endif 809#ifdef INET 810 { 811 m->m_pkthdr.csum_flags = CSUM_TCP; 812 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 813 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 814 } 815#endif /* INET */ 816#ifdef TCPDEBUG 817 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 818 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 819#endif 820 if (flags & TH_RST) 821 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 822 tp, nth); 823 824 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 825#ifdef INET6 826 if (isipv6) 827 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 828#endif /* INET6 */ 829#if defined(INET) && defined(INET6) 830 else 831#endif 832#ifdef INET 833 (void) ip_output(m, NULL, NULL, 0, NULL, inp); 834#endif 835} 836 837/* 838 * Create a new TCP control block, making an 839 * empty reassembly queue and hooking it to the argument 840 * protocol control block. The `inp' parameter must have 841 * come from the zone allocator set up in tcp_init(). 842 */ 843struct tcpcb * 844tcp_newtcpcb(struct inpcb *inp) 845{ 846 struct tcpcb_mem *tm; 847 struct tcpcb *tp; 848#ifdef INET6 849 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 850#endif /* INET6 */ 851 852 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 853 if (tm == NULL) 854 return (NULL); 855 tp = &tm->tcb; 856 857 /* Initialise cc_var struct for this tcpcb. */ 858 tp->ccv = &tm->ccv; 859 tp->ccv->type = IPPROTO_TCP; 860 tp->ccv->ccvc.tcp = tp; 861 862 /* 863 * Use the current system default CC algorithm. 864 */ 865 CC_LIST_RLOCK(); 866 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 867 CC_ALGO(tp) = CC_DEFAULT(); 868 CC_LIST_RUNLOCK(); 869 870 if (CC_ALGO(tp)->cb_init != NULL) 871 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 872 uma_zfree(V_tcpcb_zone, tm); 873 return (NULL); 874 } 875 876 tp->osd = &tm->osd; 877 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 878 uma_zfree(V_tcpcb_zone, tm); 879 return (NULL); 880 } 881 882#ifdef VIMAGE 883 tp->t_vnet = inp->inp_vnet; 884#endif 885 tp->t_timers = &tm->tt; 886 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 887 tp->t_maxseg = tp->t_maxopd = 888#ifdef INET6 889 isipv6 ? V_tcp_v6mssdflt : 890#endif /* INET6 */ 891 V_tcp_mssdflt; 892 893 /* Set up our timeouts. */ 894 callout_init(&tp->t_timers->tt_rexmt, 1); 895 callout_init(&tp->t_timers->tt_persist, 1); 896 callout_init(&tp->t_timers->tt_keep, 1); 897 callout_init(&tp->t_timers->tt_2msl, 1); 898 callout_init(&tp->t_timers->tt_delack, 1); 899 900 if (V_tcp_do_rfc1323) 901 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 902 if (V_tcp_do_sack) 903 tp->t_flags |= TF_SACK_PERMIT; 904 TAILQ_INIT(&tp->snd_holes); 905 /* 906 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 907 * is called. 908 */ 909 in_pcbref(inp); /* Reference for tcpcb */ 910 tp->t_inpcb = inp; 911 912 /* 913 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 914 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 915 * reasonable initial retransmit time. 916 */ 917 tp->t_srtt = TCPTV_SRTTBASE; 918 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 919 tp->t_rttmin = tcp_rexmit_min; 920 tp->t_rxtcur = TCPTV_RTOBASE; 921 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 922 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 923 tp->t_rcvtime = ticks; 924 /* 925 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 926 * because the socket may be bound to an IPv6 wildcard address, 927 * which may match an IPv4-mapped IPv6 address. 928 */ 929 inp->inp_ip_ttl = V_ip_defttl; 930 inp->inp_ppcb = tp; 931 return (tp); /* XXX */ 932} 933 934/* 935 * Switch the congestion control algorithm back to NewReno for any active 936 * control blocks using an algorithm which is about to go away. 937 * This ensures the CC framework can allow the unload to proceed without leaving 938 * any dangling pointers which would trigger a panic. 939 * Returning non-zero would inform the CC framework that something went wrong 940 * and it would be unsafe to allow the unload to proceed. However, there is no 941 * way for this to occur with this implementation so we always return zero. 942 */ 943int 944tcp_ccalgounload(struct cc_algo *unload_algo) 945{ 946 struct cc_algo *tmpalgo; 947 struct inpcb *inp; 948 struct tcpcb *tp; 949 VNET_ITERATOR_DECL(vnet_iter); 950 951 /* 952 * Check all active control blocks across all network stacks and change 953 * any that are using "unload_algo" back to NewReno. If "unload_algo" 954 * requires cleanup code to be run, call it. 955 */ 956 VNET_LIST_RLOCK(); 957 VNET_FOREACH(vnet_iter) { 958 CURVNET_SET(vnet_iter); 959 INP_INFO_WLOCK(&V_tcbinfo); 960 /* 961 * New connections already part way through being initialised 962 * with the CC algo we're removing will not race with this code 963 * because the INP_INFO_WLOCK is held during initialisation. We 964 * therefore don't enter the loop below until the connection 965 * list has stabilised. 966 */ 967 LIST_FOREACH(inp, &V_tcb, inp_list) { 968 INP_WLOCK(inp); 969 /* Important to skip tcptw structs. */ 970 if (!(inp->inp_flags & INP_TIMEWAIT) && 971 (tp = intotcpcb(inp)) != NULL) { 972 /* 973 * By holding INP_WLOCK here, we are assured 974 * that the connection is not currently 975 * executing inside the CC module's functions 976 * i.e. it is safe to make the switch back to 977 * NewReno. 978 */ 979 if (CC_ALGO(tp) == unload_algo) { 980 tmpalgo = CC_ALGO(tp); 981 /* NewReno does not require any init. */ 982 CC_ALGO(tp) = &newreno_cc_algo; 983 if (tmpalgo->cb_destroy != NULL) 984 tmpalgo->cb_destroy(tp->ccv); 985 } 986 } 987 INP_WUNLOCK(inp); 988 } 989 INP_INFO_WUNLOCK(&V_tcbinfo); 990 CURVNET_RESTORE(); 991 } 992 VNET_LIST_RUNLOCK(); 993 994 return (0); 995} 996 997/* 998 * Drop a TCP connection, reporting 999 * the specified error. If connection is synchronized, 1000 * then send a RST to peer. 1001 */ 1002struct tcpcb * 1003tcp_drop(struct tcpcb *tp, int errno) 1004{ 1005 struct socket *so = tp->t_inpcb->inp_socket; 1006 1007 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1008 INP_WLOCK_ASSERT(tp->t_inpcb); 1009 1010 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1011 tcp_state_change(tp, TCPS_CLOSED); 1012 (void) tcp_output(tp); 1013 TCPSTAT_INC(tcps_drops); 1014 } else 1015 TCPSTAT_INC(tcps_conndrops); 1016 if (errno == ETIMEDOUT && tp->t_softerror) 1017 errno = tp->t_softerror; 1018 so->so_error = errno; 1019 return (tcp_close(tp)); 1020} 1021 1022void 1023tcp_discardcb(struct tcpcb *tp) 1024{ 1025 struct inpcb *inp = tp->t_inpcb; 1026 struct socket *so = inp->inp_socket; 1027#ifdef INET6 1028 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1029#endif /* INET6 */ 1030 int released; 1031 1032 INP_WLOCK_ASSERT(inp); 1033 1034 /* 1035 * Make sure that all of our timers are stopped before we delete the 1036 * PCB. 1037 * 1038 * If stopping a timer fails, we schedule a discard function in same 1039 * callout, and the last discard function called will take care of 1040 * deleting the tcpcb. 1041 */ 1042 tcp_timer_stop(tp, TT_REXMT); 1043 tcp_timer_stop(tp, TT_PERSIST); 1044 tcp_timer_stop(tp, TT_KEEP); 1045 tcp_timer_stop(tp, TT_2MSL); 1046 tcp_timer_stop(tp, TT_DELACK); 1047 1048 /* 1049 * If we got enough samples through the srtt filter, 1050 * save the rtt and rttvar in the routing entry. 1051 * 'Enough' is arbitrarily defined as 4 rtt samples. 1052 * 4 samples is enough for the srtt filter to converge 1053 * to within enough % of the correct value; fewer samples 1054 * and we could save a bogus rtt. The danger is not high 1055 * as tcp quickly recovers from everything. 1056 * XXX: Works very well but needs some more statistics! 1057 */ 1058 if (tp->t_rttupdated >= 4) { 1059 struct hc_metrics_lite metrics; 1060 u_long ssthresh; 1061 1062 bzero(&metrics, sizeof(metrics)); 1063 /* 1064 * Update the ssthresh always when the conditions below 1065 * are satisfied. This gives us better new start value 1066 * for the congestion avoidance for new connections. 1067 * ssthresh is only set if packet loss occured on a session. 1068 * 1069 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1070 * being torn down. Ideally this code would not use 'so'. 1071 */ 1072 ssthresh = tp->snd_ssthresh; 1073 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1074 /* 1075 * convert the limit from user data bytes to 1076 * packets then to packet data bytes. 1077 */ 1078 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1079 if (ssthresh < 2) 1080 ssthresh = 2; 1081 ssthresh *= (u_long)(tp->t_maxseg + 1082#ifdef INET6 1083 (isipv6 ? sizeof (struct ip6_hdr) + 1084 sizeof (struct tcphdr) : 1085#endif 1086 sizeof (struct tcpiphdr) 1087#ifdef INET6 1088 ) 1089#endif 1090 ); 1091 } else 1092 ssthresh = 0; 1093 metrics.rmx_ssthresh = ssthresh; 1094 1095 metrics.rmx_rtt = tp->t_srtt; 1096 metrics.rmx_rttvar = tp->t_rttvar; 1097 metrics.rmx_cwnd = tp->snd_cwnd; 1098 metrics.rmx_sendpipe = 0; 1099 metrics.rmx_recvpipe = 0; 1100 1101 tcp_hc_update(&inp->inp_inc, &metrics); 1102 } 1103 1104 /* free the reassembly queue, if any */ 1105 tcp_reass_flush(tp); 1106 1107#ifdef TCP_OFFLOAD 1108 /* Disconnect offload device, if any. */ 1109 if (tp->t_flags & TF_TOE) 1110 tcp_offload_detach(tp); 1111#endif 1112 1113 tcp_free_sackholes(tp); 1114 1115 /* Allow the CC algorithm to clean up after itself. */ 1116 if (CC_ALGO(tp)->cb_destroy != NULL) 1117 CC_ALGO(tp)->cb_destroy(tp->ccv); 1118 1119 khelp_destroy_osd(tp->osd); 1120 1121 CC_ALGO(tp) = NULL; 1122 inp->inp_ppcb = NULL; 1123 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1124 /* We own the last reference on tcpcb, let's free it. */ 1125 tp->t_inpcb = NULL; 1126 uma_zfree(V_tcpcb_zone, tp); 1127 released = in_pcbrele_wlocked(inp); 1128 KASSERT(!released, ("%s: inp %p should not have been released " 1129 "here", __func__, inp)); 1130 } 1131} 1132 1133void 1134tcp_timer_2msl_discard(void *xtp) 1135{ 1136 1137 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1138} 1139 1140void 1141tcp_timer_keep_discard(void *xtp) 1142{ 1143 1144 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1145} 1146 1147void 1148tcp_timer_persist_discard(void *xtp) 1149{ 1150 1151 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1152} 1153 1154void 1155tcp_timer_rexmt_discard(void *xtp) 1156{ 1157 1158 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1159} 1160 1161void 1162tcp_timer_delack_discard(void *xtp) 1163{ 1164 1165 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1166} 1167 1168void 1169tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1170{ 1171 struct inpcb *inp; 1172 1173 CURVNET_SET(tp->t_vnet); 1174 INP_INFO_RLOCK(&V_tcbinfo); 1175 inp = tp->t_inpcb; 1176 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1177 __func__, tp)); 1178 INP_WLOCK(inp); 1179 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1180 ("%s: tcpcb has to be stopped here", __func__)); 1181 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1182 ("%s: discard callout should be running", __func__)); 1183 tp->t_timers->tt_flags &= ~timer_type; 1184 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1185 /* We own the last reference on this tcpcb, let's free it. */ 1186 tp->t_inpcb = NULL; 1187 uma_zfree(V_tcpcb_zone, tp); 1188 if (in_pcbrele_wlocked(inp)) { 1189 INP_INFO_RUNLOCK(&V_tcbinfo); 1190 CURVNET_RESTORE(); 1191 return; 1192 } 1193 } 1194 INP_WUNLOCK(inp); 1195 INP_INFO_RUNLOCK(&V_tcbinfo); 1196 CURVNET_RESTORE(); 1197} 1198 1199/* 1200 * Attempt to close a TCP control block, marking it as dropped, and freeing 1201 * the socket if we hold the only reference. 1202 */ 1203struct tcpcb * 1204tcp_close(struct tcpcb *tp) 1205{ 1206 struct inpcb *inp = tp->t_inpcb; 1207 struct socket *so; 1208 1209 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1210 INP_WLOCK_ASSERT(inp); 1211 1212#ifdef TCP_OFFLOAD 1213 if (tp->t_state == TCPS_LISTEN) 1214 tcp_offload_listen_stop(tp); 1215#endif 1216#ifdef TCP_RFC7413 1217 /* 1218 * This releases the TFO pending counter resource for TFO listen 1219 * sockets as well as passively-created TFO sockets that transition 1220 * from SYN_RECEIVED to CLOSED. 1221 */ 1222 if (tp->t_tfo_pending) { 1223 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1224 tp->t_tfo_pending = NULL; 1225 } 1226#endif 1227 in_pcbdrop(inp); 1228 TCPSTAT_INC(tcps_closed); 1229 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1230 so = inp->inp_socket; 1231 soisdisconnected(so); 1232 if (inp->inp_flags & INP_SOCKREF) { 1233 KASSERT(so->so_state & SS_PROTOREF, 1234 ("tcp_close: !SS_PROTOREF")); 1235 inp->inp_flags &= ~INP_SOCKREF; 1236 INP_WUNLOCK(inp); 1237 ACCEPT_LOCK(); 1238 SOCK_LOCK(so); 1239 so->so_state &= ~SS_PROTOREF; 1240 sofree(so); 1241 return (NULL); 1242 } 1243 return (tp); 1244} 1245 1246void 1247tcp_drain(void) 1248{ 1249 VNET_ITERATOR_DECL(vnet_iter); 1250 1251 if (!do_tcpdrain) 1252 return; 1253 1254 VNET_LIST_RLOCK_NOSLEEP(); 1255 VNET_FOREACH(vnet_iter) { 1256 CURVNET_SET(vnet_iter); 1257 struct inpcb *inpb; 1258 struct tcpcb *tcpb; 1259 1260 /* 1261 * Walk the tcpbs, if existing, and flush the reassembly queue, 1262 * if there is one... 1263 * XXX: The "Net/3" implementation doesn't imply that the TCP 1264 * reassembly queue should be flushed, but in a situation 1265 * where we're really low on mbufs, this is potentially 1266 * useful. 1267 */ 1268 INP_INFO_WLOCK(&V_tcbinfo); 1269 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1270 if (inpb->inp_flags & INP_TIMEWAIT) 1271 continue; 1272 INP_WLOCK(inpb); 1273 if ((tcpb = intotcpcb(inpb)) != NULL) { 1274 tcp_reass_flush(tcpb); 1275 tcp_clean_sackreport(tcpb); 1276 } 1277 INP_WUNLOCK(inpb); 1278 } 1279 INP_INFO_WUNLOCK(&V_tcbinfo); 1280 CURVNET_RESTORE(); 1281 } 1282 VNET_LIST_RUNLOCK_NOSLEEP(); 1283} 1284 1285/* 1286 * Notify a tcp user of an asynchronous error; 1287 * store error as soft error, but wake up user 1288 * (for now, won't do anything until can select for soft error). 1289 * 1290 * Do not wake up user since there currently is no mechanism for 1291 * reporting soft errors (yet - a kqueue filter may be added). 1292 */ 1293static struct inpcb * 1294tcp_notify(struct inpcb *inp, int error) 1295{ 1296 struct tcpcb *tp; 1297 1298 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1299 INP_WLOCK_ASSERT(inp); 1300 1301 if ((inp->inp_flags & INP_TIMEWAIT) || 1302 (inp->inp_flags & INP_DROPPED)) 1303 return (inp); 1304 1305 tp = intotcpcb(inp); 1306 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1307 1308 /* 1309 * Ignore some errors if we are hooked up. 1310 * If connection hasn't completed, has retransmitted several times, 1311 * and receives a second error, give up now. This is better 1312 * than waiting a long time to establish a connection that 1313 * can never complete. 1314 */ 1315 if (tp->t_state == TCPS_ESTABLISHED && 1316 (error == EHOSTUNREACH || error == ENETUNREACH || 1317 error == EHOSTDOWN)) { 1318 return (inp); 1319 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1320 tp->t_softerror) { 1321 tp = tcp_drop(tp, error); 1322 if (tp != NULL) 1323 return (inp); 1324 else 1325 return (NULL); 1326 } else { 1327 tp->t_softerror = error; 1328 return (inp); 1329 } 1330#if 0 1331 wakeup( &so->so_timeo); 1332 sorwakeup(so); 1333 sowwakeup(so); 1334#endif 1335} 1336 1337static int 1338tcp_pcblist(SYSCTL_HANDLER_ARGS) 1339{ 1340 int error, i, m, n, pcb_count; 1341 struct inpcb *inp, **inp_list; 1342 inp_gen_t gencnt; 1343 struct xinpgen xig; 1344 1345 /* 1346 * The process of preparing the TCB list is too time-consuming and 1347 * resource-intensive to repeat twice on every request. 1348 */ 1349 if (req->oldptr == NULL) { 1350 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1351 n += imax(n / 8, 10); 1352 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1353 return (0); 1354 } 1355 1356 if (req->newptr != NULL) 1357 return (EPERM); 1358 1359 /* 1360 * OK, now we're committed to doing something. 1361 */ 1362 INP_LIST_RLOCK(&V_tcbinfo); 1363 gencnt = V_tcbinfo.ipi_gencnt; 1364 n = V_tcbinfo.ipi_count; 1365 INP_LIST_RUNLOCK(&V_tcbinfo); 1366 1367 m = syncache_pcbcount(); 1368 1369 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1370 + (n + m) * sizeof(struct xtcpcb)); 1371 if (error != 0) 1372 return (error); 1373 1374 xig.xig_len = sizeof xig; 1375 xig.xig_count = n + m; 1376 xig.xig_gen = gencnt; 1377 xig.xig_sogen = so_gencnt; 1378 error = SYSCTL_OUT(req, &xig, sizeof xig); 1379 if (error) 1380 return (error); 1381 1382 error = syncache_pcblist(req, m, &pcb_count); 1383 if (error) 1384 return (error); 1385 1386 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1387 1388 INP_INFO_WLOCK(&V_tcbinfo); 1389 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1390 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1391 INP_WLOCK(inp); 1392 if (inp->inp_gencnt <= gencnt) { 1393 /* 1394 * XXX: This use of cr_cansee(), introduced with 1395 * TCP state changes, is not quite right, but for 1396 * now, better than nothing. 1397 */ 1398 if (inp->inp_flags & INP_TIMEWAIT) { 1399 if (intotw(inp) != NULL) 1400 error = cr_cansee(req->td->td_ucred, 1401 intotw(inp)->tw_cred); 1402 else 1403 error = EINVAL; /* Skip this inp. */ 1404 } else 1405 error = cr_canseeinpcb(req->td->td_ucred, inp); 1406 if (error == 0) { 1407 in_pcbref(inp); 1408 inp_list[i++] = inp; 1409 } 1410 } 1411 INP_WUNLOCK(inp); 1412 } 1413 INP_INFO_WUNLOCK(&V_tcbinfo); 1414 n = i; 1415 1416 error = 0; 1417 for (i = 0; i < n; i++) { 1418 inp = inp_list[i]; 1419 INP_RLOCK(inp); 1420 if (inp->inp_gencnt <= gencnt) { 1421 struct xtcpcb xt; 1422 void *inp_ppcb; 1423 1424 bzero(&xt, sizeof(xt)); 1425 xt.xt_len = sizeof xt; 1426 /* XXX should avoid extra copy */ 1427 bcopy(inp, &xt.xt_inp, sizeof *inp); 1428 inp_ppcb = inp->inp_ppcb; 1429 if (inp_ppcb == NULL) 1430 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1431 else if (inp->inp_flags & INP_TIMEWAIT) { 1432 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1433 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1434 } else { 1435 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1436 if (xt.xt_tp.t_timers) 1437 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1438 } 1439 if (inp->inp_socket != NULL) 1440 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1441 else { 1442 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1443 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1444 } 1445 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1446 INP_RUNLOCK(inp); 1447 error = SYSCTL_OUT(req, &xt, sizeof xt); 1448 } else 1449 INP_RUNLOCK(inp); 1450 } 1451 INP_INFO_RLOCK(&V_tcbinfo); 1452 for (i = 0; i < n; i++) { 1453 inp = inp_list[i]; 1454 INP_RLOCK(inp); 1455 if (!in_pcbrele_rlocked(inp)) 1456 INP_RUNLOCK(inp); 1457 } 1458 INP_INFO_RUNLOCK(&V_tcbinfo); 1459 1460 if (!error) { 1461 /* 1462 * Give the user an updated idea of our state. 1463 * If the generation differs from what we told 1464 * her before, she knows that something happened 1465 * while we were processing this request, and it 1466 * might be necessary to retry. 1467 */ 1468 INP_LIST_RLOCK(&V_tcbinfo); 1469 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1470 xig.xig_sogen = so_gencnt; 1471 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1472 INP_LIST_RUNLOCK(&V_tcbinfo); 1473 error = SYSCTL_OUT(req, &xig, sizeof xig); 1474 } 1475 free(inp_list, M_TEMP); 1476 return (error); 1477} 1478 1479SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1480 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1481 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1482 1483#ifdef INET 1484static int 1485tcp_getcred(SYSCTL_HANDLER_ARGS) 1486{ 1487 struct xucred xuc; 1488 struct sockaddr_in addrs[2]; 1489 struct inpcb *inp; 1490 int error; 1491 1492 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1493 if (error) 1494 return (error); 1495 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1496 if (error) 1497 return (error); 1498 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1499 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1500 if (inp != NULL) { 1501 if (inp->inp_socket == NULL) 1502 error = ENOENT; 1503 if (error == 0) 1504 error = cr_canseeinpcb(req->td->td_ucred, inp); 1505 if (error == 0) 1506 cru2x(inp->inp_cred, &xuc); 1507 INP_RUNLOCK(inp); 1508 } else 1509 error = ENOENT; 1510 if (error == 0) 1511 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1512 return (error); 1513} 1514 1515SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1516 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1517 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1518#endif /* INET */ 1519 1520#ifdef INET6 1521static int 1522tcp6_getcred(SYSCTL_HANDLER_ARGS) 1523{ 1524 struct xucred xuc; 1525 struct sockaddr_in6 addrs[2]; 1526 struct inpcb *inp; 1527 int error; 1528#ifdef INET 1529 int mapped = 0; 1530#endif 1531 1532 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1533 if (error) 1534 return (error); 1535 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1536 if (error) 1537 return (error); 1538 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1539 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1540 return (error); 1541 } 1542 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1543#ifdef INET 1544 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1545 mapped = 1; 1546 else 1547#endif 1548 return (EINVAL); 1549 } 1550 1551#ifdef INET 1552 if (mapped == 1) 1553 inp = in_pcblookup(&V_tcbinfo, 1554 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1555 addrs[1].sin6_port, 1556 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1557 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1558 else 1559#endif 1560 inp = in6_pcblookup(&V_tcbinfo, 1561 &addrs[1].sin6_addr, addrs[1].sin6_port, 1562 &addrs[0].sin6_addr, addrs[0].sin6_port, 1563 INPLOOKUP_RLOCKPCB, NULL); 1564 if (inp != NULL) { 1565 if (inp->inp_socket == NULL) 1566 error = ENOENT; 1567 if (error == 0) 1568 error = cr_canseeinpcb(req->td->td_ucred, inp); 1569 if (error == 0) 1570 cru2x(inp->inp_cred, &xuc); 1571 INP_RUNLOCK(inp); 1572 } else 1573 error = ENOENT; 1574 if (error == 0) 1575 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1576 return (error); 1577} 1578 1579SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1580 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1581 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1582#endif /* INET6 */ 1583 1584 1585#ifdef INET 1586void 1587tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1588{ 1589 struct ip *ip = vip; 1590 struct tcphdr *th; 1591 struct in_addr faddr; 1592 struct inpcb *inp; 1593 struct tcpcb *tp; 1594 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1595 struct icmp *icp; 1596 struct in_conninfo inc; 1597 tcp_seq icmp_tcp_seq; 1598 int mtu; 1599 1600 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1601 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1602 return; 1603 1604 if (cmd == PRC_MSGSIZE) 1605 notify = tcp_mtudisc_notify; 1606 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1607 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1608 notify = tcp_drop_syn_sent; 1609 /* 1610 * Redirects don't need to be handled up here. 1611 */ 1612 else if (PRC_IS_REDIRECT(cmd)) 1613 return; 1614 /* 1615 * Source quench is depreciated. 1616 */ 1617 else if (cmd == PRC_QUENCH) 1618 return; 1619 /* 1620 * Hostdead is ugly because it goes linearly through all PCBs. 1621 * XXX: We never get this from ICMP, otherwise it makes an 1622 * excellent DoS attack on machines with many connections. 1623 */ 1624 else if (cmd == PRC_HOSTDEAD) 1625 ip = NULL; 1626 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1627 return; 1628 if (ip != NULL) { 1629 icp = (struct icmp *)((caddr_t)ip 1630 - offsetof(struct icmp, icmp_ip)); 1631 th = (struct tcphdr *)((caddr_t)ip 1632 + (ip->ip_hl << 2)); 1633 INP_INFO_RLOCK(&V_tcbinfo); 1634 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, 1635 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1636 if (inp != NULL) { 1637 if (!(inp->inp_flags & INP_TIMEWAIT) && 1638 !(inp->inp_flags & INP_DROPPED) && 1639 !(inp->inp_socket == NULL)) { 1640 icmp_tcp_seq = htonl(th->th_seq); 1641 tp = intotcpcb(inp); 1642 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1643 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1644 if (cmd == PRC_MSGSIZE) { 1645 /* 1646 * MTU discovery: 1647 * If we got a needfrag set the MTU 1648 * in the route to the suggested new 1649 * value (if given) and then notify. 1650 */ 1651 bzero(&inc, sizeof(inc)); 1652 inc.inc_faddr = faddr; 1653 inc.inc_fibnum = 1654 inp->inp_inc.inc_fibnum; 1655 1656 mtu = ntohs(icp->icmp_nextmtu); 1657 /* 1658 * If no alternative MTU was 1659 * proposed, try the next smaller 1660 * one. 1661 */ 1662 if (!mtu) 1663 mtu = ip_next_mtu( 1664 ntohs(ip->ip_len), 1); 1665 if (mtu < V_tcp_minmss 1666 + sizeof(struct tcpiphdr)) 1667 mtu = V_tcp_minmss 1668 + sizeof(struct tcpiphdr); 1669 /* 1670 * Only cache the MTU if it 1671 * is smaller than the interface 1672 * or route MTU. tcp_mtudisc() 1673 * will do right thing by itself. 1674 */ 1675 if (mtu <= tcp_maxmtu(&inc, NULL)) 1676 tcp_hc_updatemtu(&inc, mtu); 1677 tcp_mtudisc(inp, mtu); 1678 } else 1679 inp = (*notify)(inp, 1680 inetctlerrmap[cmd]); 1681 } 1682 } 1683 if (inp != NULL) 1684 INP_WUNLOCK(inp); 1685 } else { 1686 bzero(&inc, sizeof(inc)); 1687 inc.inc_fport = th->th_dport; 1688 inc.inc_lport = th->th_sport; 1689 inc.inc_faddr = faddr; 1690 inc.inc_laddr = ip->ip_src; 1691 syncache_unreach(&inc, th); 1692 } 1693 INP_INFO_RUNLOCK(&V_tcbinfo); 1694 } else 1695 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1696} 1697#endif /* INET */ 1698 1699#ifdef INET6 1700void 1701tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1702{ 1703 struct tcphdr th; 1704 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1705 struct ip6_hdr *ip6; 1706 struct mbuf *m; 1707 struct ip6ctlparam *ip6cp = NULL; 1708 const struct sockaddr_in6 *sa6_src = NULL; 1709 int off; 1710 struct tcp_portonly { 1711 u_int16_t th_sport; 1712 u_int16_t th_dport; 1713 } *thp; 1714 1715 if (sa->sa_family != AF_INET6 || 1716 sa->sa_len != sizeof(struct sockaddr_in6)) 1717 return; 1718 1719 if (cmd == PRC_MSGSIZE) 1720 notify = tcp_mtudisc_notify; 1721 else if (!PRC_IS_REDIRECT(cmd) && 1722 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1723 return; 1724 /* Source quench is depreciated. */ 1725 else if (cmd == PRC_QUENCH) 1726 return; 1727 1728 /* if the parameter is from icmp6, decode it. */ 1729 if (d != NULL) { 1730 ip6cp = (struct ip6ctlparam *)d; 1731 m = ip6cp->ip6c_m; 1732 ip6 = ip6cp->ip6c_ip6; 1733 off = ip6cp->ip6c_off; 1734 sa6_src = ip6cp->ip6c_src; 1735 } else { 1736 m = NULL; 1737 ip6 = NULL; 1738 off = 0; /* fool gcc */ 1739 sa6_src = &sa6_any; 1740 } 1741 1742 if (ip6 != NULL) { 1743 struct in_conninfo inc; 1744 /* 1745 * XXX: We assume that when IPV6 is non NULL, 1746 * M and OFF are valid. 1747 */ 1748 1749 /* check if we can safely examine src and dst ports */ 1750 if (m->m_pkthdr.len < off + sizeof(*thp)) 1751 return; 1752 1753 bzero(&th, sizeof(th)); 1754 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1755 1756 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1757 (struct sockaddr *)ip6cp->ip6c_src, 1758 th.th_sport, cmd, NULL, notify); 1759 1760 bzero(&inc, sizeof(inc)); 1761 inc.inc_fport = th.th_dport; 1762 inc.inc_lport = th.th_sport; 1763 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1764 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1765 inc.inc_flags |= INC_ISIPV6; 1766 INP_INFO_RLOCK(&V_tcbinfo); 1767 syncache_unreach(&inc, &th); 1768 INP_INFO_RUNLOCK(&V_tcbinfo); 1769 } else 1770 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1771 0, cmd, NULL, notify); 1772} 1773#endif /* INET6 */ 1774 1775 1776/* 1777 * Following is where TCP initial sequence number generation occurs. 1778 * 1779 * There are two places where we must use initial sequence numbers: 1780 * 1. In SYN-ACK packets. 1781 * 2. In SYN packets. 1782 * 1783 * All ISNs for SYN-ACK packets are generated by the syncache. See 1784 * tcp_syncache.c for details. 1785 * 1786 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1787 * depends on this property. In addition, these ISNs should be 1788 * unguessable so as to prevent connection hijacking. To satisfy 1789 * the requirements of this situation, the algorithm outlined in 1790 * RFC 1948 is used, with only small modifications. 1791 * 1792 * Implementation details: 1793 * 1794 * Time is based off the system timer, and is corrected so that it 1795 * increases by one megabyte per second. This allows for proper 1796 * recycling on high speed LANs while still leaving over an hour 1797 * before rollover. 1798 * 1799 * As reading the *exact* system time is too expensive to be done 1800 * whenever setting up a TCP connection, we increment the time 1801 * offset in two ways. First, a small random positive increment 1802 * is added to isn_offset for each connection that is set up. 1803 * Second, the function tcp_isn_tick fires once per clock tick 1804 * and increments isn_offset as necessary so that sequence numbers 1805 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1806 * random positive increments serve only to ensure that the same 1807 * exact sequence number is never sent out twice (as could otherwise 1808 * happen when a port is recycled in less than the system tick 1809 * interval.) 1810 * 1811 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1812 * between seeding of isn_secret. This is normally set to zero, 1813 * as reseeding should not be necessary. 1814 * 1815 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1816 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1817 * general, this means holding an exclusive (write) lock. 1818 */ 1819 1820#define ISN_BYTES_PER_SECOND 1048576 1821#define ISN_STATIC_INCREMENT 4096 1822#define ISN_RANDOM_INCREMENT (4096 - 1) 1823 1824static VNET_DEFINE(u_char, isn_secret[32]); 1825static VNET_DEFINE(int, isn_last); 1826static VNET_DEFINE(int, isn_last_reseed); 1827static VNET_DEFINE(u_int32_t, isn_offset); 1828static VNET_DEFINE(u_int32_t, isn_offset_old); 1829 1830#define V_isn_secret VNET(isn_secret) 1831#define V_isn_last VNET(isn_last) 1832#define V_isn_last_reseed VNET(isn_last_reseed) 1833#define V_isn_offset VNET(isn_offset) 1834#define V_isn_offset_old VNET(isn_offset_old) 1835 1836tcp_seq 1837tcp_new_isn(struct tcpcb *tp) 1838{ 1839 MD5_CTX isn_ctx; 1840 u_int32_t md5_buffer[4]; 1841 tcp_seq new_isn; 1842 u_int32_t projected_offset; 1843 1844 INP_WLOCK_ASSERT(tp->t_inpcb); 1845 1846 ISN_LOCK(); 1847 /* Seed if this is the first use, reseed if requested. */ 1848 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1849 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1850 < (u_int)ticks))) { 1851 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1852 V_isn_last_reseed = ticks; 1853 } 1854 1855 /* Compute the md5 hash and return the ISN. */ 1856 MD5Init(&isn_ctx); 1857 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1858 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1859#ifdef INET6 1860 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1861 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1862 sizeof(struct in6_addr)); 1863 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1864 sizeof(struct in6_addr)); 1865 } else 1866#endif 1867 { 1868 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1869 sizeof(struct in_addr)); 1870 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1871 sizeof(struct in_addr)); 1872 } 1873 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1874 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1875 new_isn = (tcp_seq) md5_buffer[0]; 1876 V_isn_offset += ISN_STATIC_INCREMENT + 1877 (arc4random() & ISN_RANDOM_INCREMENT); 1878 if (ticks != V_isn_last) { 1879 projected_offset = V_isn_offset_old + 1880 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1881 if (SEQ_GT(projected_offset, V_isn_offset)) 1882 V_isn_offset = projected_offset; 1883 V_isn_offset_old = V_isn_offset; 1884 V_isn_last = ticks; 1885 } 1886 new_isn += V_isn_offset; 1887 ISN_UNLOCK(); 1888 return (new_isn); 1889} 1890 1891/* 1892 * When a specific ICMP unreachable message is received and the 1893 * connection state is SYN-SENT, drop the connection. This behavior 1894 * is controlled by the icmp_may_rst sysctl. 1895 */ 1896struct inpcb * 1897tcp_drop_syn_sent(struct inpcb *inp, int errno) 1898{ 1899 struct tcpcb *tp; 1900 1901 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 1902 INP_WLOCK_ASSERT(inp); 1903 1904 if ((inp->inp_flags & INP_TIMEWAIT) || 1905 (inp->inp_flags & INP_DROPPED)) 1906 return (inp); 1907 1908 tp = intotcpcb(inp); 1909 if (tp->t_state != TCPS_SYN_SENT) 1910 return (inp); 1911 1912 tp = tcp_drop(tp, errno); 1913 if (tp != NULL) 1914 return (inp); 1915 else 1916 return (NULL); 1917} 1918 1919/* 1920 * When `need fragmentation' ICMP is received, update our idea of the MSS 1921 * based on the new value. Also nudge TCP to send something, since we 1922 * know the packet we just sent was dropped. 1923 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1924 */ 1925static struct inpcb * 1926tcp_mtudisc_notify(struct inpcb *inp, int error) 1927{ 1928 1929 return (tcp_mtudisc(inp, -1)); 1930} 1931 1932struct inpcb * 1933tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1934{ 1935 struct tcpcb *tp; 1936 struct socket *so; 1937 1938 INP_WLOCK_ASSERT(inp); 1939 if ((inp->inp_flags & INP_TIMEWAIT) || 1940 (inp->inp_flags & INP_DROPPED)) 1941 return (inp); 1942 1943 tp = intotcpcb(inp); 1944 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1945 1946 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1947 1948 so = inp->inp_socket; 1949 SOCKBUF_LOCK(&so->so_snd); 1950 /* If the mss is larger than the socket buffer, decrease the mss. */ 1951 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1952 tp->t_maxseg = so->so_snd.sb_hiwat; 1953 SOCKBUF_UNLOCK(&so->so_snd); 1954 1955 TCPSTAT_INC(tcps_mturesent); 1956 tp->t_rtttime = 0; 1957 tp->snd_nxt = tp->snd_una; 1958 tcp_free_sackholes(tp); 1959 tp->snd_recover = tp->snd_max; 1960 if (tp->t_flags & TF_SACK_PERMIT) 1961 EXIT_FASTRECOVERY(tp->t_flags); 1962 tcp_output(tp); 1963 return (inp); 1964} 1965 1966#ifdef INET 1967/* 1968 * Look-up the routing entry to the peer of this inpcb. If no route 1969 * is found and it cannot be allocated, then return 0. This routine 1970 * is called by TCP routines that access the rmx structure and by 1971 * tcp_mss_update to get the peer/interface MTU. 1972 */ 1973u_long 1974tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 1975{ 1976 struct route sro; 1977 struct sockaddr_in *dst; 1978 struct ifnet *ifp; 1979 u_long maxmtu = 0; 1980 1981 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1982 1983 bzero(&sro, sizeof(sro)); 1984 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1985 dst = (struct sockaddr_in *)&sro.ro_dst; 1986 dst->sin_family = AF_INET; 1987 dst->sin_len = sizeof(*dst); 1988 dst->sin_addr = inc->inc_faddr; 1989 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1990 } 1991 if (sro.ro_rt != NULL) { 1992 ifp = sro.ro_rt->rt_ifp; 1993 if (sro.ro_rt->rt_mtu == 0) 1994 maxmtu = ifp->if_mtu; 1995 else 1996 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 1997 1998 /* Report additional interface capabilities. */ 1999 if (cap != NULL) { 2000 if (ifp->if_capenable & IFCAP_TSO4 && 2001 ifp->if_hwassist & CSUM_TSO) { 2002 cap->ifcap |= CSUM_TSO; 2003 cap->tsomax = ifp->if_hw_tsomax; 2004 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2005 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2006 } 2007 } 2008 RTFREE(sro.ro_rt); 2009 } 2010 return (maxmtu); 2011} 2012#endif /* INET */ 2013 2014#ifdef INET6 2015u_long 2016tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2017{ 2018 struct route_in6 sro6; 2019 struct ifnet *ifp; 2020 u_long maxmtu = 0; 2021 2022 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2023 2024 bzero(&sro6, sizeof(sro6)); 2025 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2026 sro6.ro_dst.sin6_family = AF_INET6; 2027 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 2028 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 2029 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 2030 } 2031 if (sro6.ro_rt != NULL) { 2032 ifp = sro6.ro_rt->rt_ifp; 2033 if (sro6.ro_rt->rt_mtu == 0) 2034 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 2035 else 2036 maxmtu = min(sro6.ro_rt->rt_mtu, 2037 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 2038 2039 /* Report additional interface capabilities. */ 2040 if (cap != NULL) { 2041 if (ifp->if_capenable & IFCAP_TSO6 && 2042 ifp->if_hwassist & CSUM_TSO) { 2043 cap->ifcap |= CSUM_TSO; 2044 cap->tsomax = ifp->if_hw_tsomax; 2045 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2046 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2047 } 2048 } 2049 RTFREE(sro6.ro_rt); 2050 } 2051 2052 return (maxmtu); 2053} 2054#endif /* INET6 */ 2055 2056#ifdef IPSEC 2057/* compute ESP/AH header size for TCP, including outer IP header. */ 2058size_t 2059ipsec_hdrsiz_tcp(struct tcpcb *tp) 2060{ 2061 struct inpcb *inp; 2062 struct mbuf *m; 2063 size_t hdrsiz; 2064 struct ip *ip; 2065#ifdef INET6 2066 struct ip6_hdr *ip6; 2067#endif 2068 struct tcphdr *th; 2069 2070 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 2071 (!key_havesp(IPSEC_DIR_OUTBOUND))) 2072 return (0); 2073 m = m_gethdr(M_NOWAIT, MT_DATA); 2074 if (!m) 2075 return (0); 2076 2077#ifdef INET6 2078 if ((inp->inp_vflag & INP_IPV6) != 0) { 2079 ip6 = mtod(m, struct ip6_hdr *); 2080 th = (struct tcphdr *)(ip6 + 1); 2081 m->m_pkthdr.len = m->m_len = 2082 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 2083 tcpip_fillheaders(inp, ip6, th); 2084 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2085 } else 2086#endif /* INET6 */ 2087 { 2088 ip = mtod(m, struct ip *); 2089 th = (struct tcphdr *)(ip + 1); 2090 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 2091 tcpip_fillheaders(inp, ip, th); 2092 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 2093 } 2094 2095 m_free(m); 2096 return (hdrsiz); 2097} 2098#endif /* IPSEC */ 2099 2100#ifdef TCP_SIGNATURE 2101/* 2102 * Callback function invoked by m_apply() to digest TCP segment data 2103 * contained within an mbuf chain. 2104 */ 2105static int 2106tcp_signature_apply(void *fstate, void *data, u_int len) 2107{ 2108 2109 MD5Update(fstate, (u_char *)data, len); 2110 return (0); 2111} 2112 2113/* 2114 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2115 * 2116 * Parameters: 2117 * m pointer to head of mbuf chain 2118 * _unused 2119 * len length of TCP segment data, excluding options 2120 * optlen length of TCP segment options 2121 * buf pointer to storage for computed MD5 digest 2122 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2123 * 2124 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2125 * When called from tcp_input(), we can be sure that th_sum has been 2126 * zeroed out and verified already. 2127 * 2128 * Return 0 if successful, otherwise return -1. 2129 * 2130 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2131 * search with the destination IP address, and a 'magic SPI' to be 2132 * determined by the application. This is hardcoded elsewhere to 1179 2133 * right now. Another branch of this code exists which uses the SPD to 2134 * specify per-application flows but it is unstable. 2135 */ 2136int 2137tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2138 u_char *buf, u_int direction) 2139{ 2140 union sockaddr_union dst; 2141#ifdef INET 2142 struct ippseudo ippseudo; 2143#endif 2144 MD5_CTX ctx; 2145 int doff; 2146 struct ip *ip; 2147#ifdef INET 2148 struct ipovly *ipovly; 2149#endif 2150 struct secasvar *sav; 2151 struct tcphdr *th; 2152#ifdef INET6 2153 struct ip6_hdr *ip6; 2154 struct in6_addr in6; 2155 char ip6buf[INET6_ADDRSTRLEN]; 2156 uint32_t plen; 2157 uint16_t nhdr; 2158#endif 2159 u_short savecsum; 2160 2161 KASSERT(m != NULL, ("NULL mbuf chain")); 2162 KASSERT(buf != NULL, ("NULL signature pointer")); 2163 2164 /* Extract the destination from the IP header in the mbuf. */ 2165 bzero(&dst, sizeof(union sockaddr_union)); 2166 ip = mtod(m, struct ip *); 2167#ifdef INET6 2168 ip6 = NULL; /* Make the compiler happy. */ 2169#endif 2170 switch (ip->ip_v) { 2171#ifdef INET 2172 case IPVERSION: 2173 dst.sa.sa_len = sizeof(struct sockaddr_in); 2174 dst.sa.sa_family = AF_INET; 2175 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2176 ip->ip_src : ip->ip_dst; 2177 break; 2178#endif 2179#ifdef INET6 2180 case (IPV6_VERSION >> 4): 2181 ip6 = mtod(m, struct ip6_hdr *); 2182 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2183 dst.sa.sa_family = AF_INET6; 2184 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2185 ip6->ip6_src : ip6->ip6_dst; 2186 break; 2187#endif 2188 default: 2189 return (EINVAL); 2190 /* NOTREACHED */ 2191 break; 2192 } 2193 2194 /* Look up an SADB entry which matches the address of the peer. */ 2195 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2196 if (sav == NULL) { 2197 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2198 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2199#ifdef INET6 2200 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2201 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2202#endif 2203 "(unsupported)")); 2204 return (EINVAL); 2205 } 2206 2207 MD5Init(&ctx); 2208 /* 2209 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2210 * 2211 * XXX The ippseudo header MUST be digested in network byte order, 2212 * or else we'll fail the regression test. Assume all fields we've 2213 * been doing arithmetic on have been in host byte order. 2214 * XXX One cannot depend on ipovly->ih_len here. When called from 2215 * tcp_output(), the underlying ip_len member has not yet been set. 2216 */ 2217 switch (ip->ip_v) { 2218#ifdef INET 2219 case IPVERSION: 2220 ipovly = (struct ipovly *)ip; 2221 ippseudo.ippseudo_src = ipovly->ih_src; 2222 ippseudo.ippseudo_dst = ipovly->ih_dst; 2223 ippseudo.ippseudo_pad = 0; 2224 ippseudo.ippseudo_p = IPPROTO_TCP; 2225 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2226 optlen); 2227 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2228 2229 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2230 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2231 break; 2232#endif 2233#ifdef INET6 2234 /* 2235 * RFC 2385, 2.0 Proposal 2236 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2237 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2238 * extended next header value (to form 32 bits), and 32-bit segment 2239 * length. 2240 * Note: Upper-Layer Packet Length comes before Next Header. 2241 */ 2242 case (IPV6_VERSION >> 4): 2243 in6 = ip6->ip6_src; 2244 in6_clearscope(&in6); 2245 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2246 in6 = ip6->ip6_dst; 2247 in6_clearscope(&in6); 2248 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2249 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2250 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2251 nhdr = 0; 2252 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2253 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2254 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2255 nhdr = IPPROTO_TCP; 2256 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2257 2258 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2259 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2260 break; 2261#endif 2262 default: 2263 return (EINVAL); 2264 /* NOTREACHED */ 2265 break; 2266 } 2267 2268 2269 /* 2270 * Step 2: Update MD5 hash with TCP header, excluding options. 2271 * The TCP checksum must be set to zero. 2272 */ 2273 savecsum = th->th_sum; 2274 th->th_sum = 0; 2275 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2276 th->th_sum = savecsum; 2277 2278 /* 2279 * Step 3: Update MD5 hash with TCP segment data. 2280 * Use m_apply() to avoid an early m_pullup(). 2281 */ 2282 if (len > 0) 2283 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2284 2285 /* 2286 * Step 4: Update MD5 hash with shared secret. 2287 */ 2288 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2289 MD5Final(buf, &ctx); 2290 2291 key_sa_recordxfer(sav, m); 2292 KEY_FREESAV(&sav); 2293 return (0); 2294} 2295 2296/* 2297 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2298 * 2299 * Parameters: 2300 * m pointer to head of mbuf chain 2301 * len length of TCP segment data, excluding options 2302 * optlen length of TCP segment options 2303 * buf pointer to storage for computed MD5 digest 2304 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2305 * 2306 * Return 1 if successful, otherwise return 0. 2307 */ 2308int 2309tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2310 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2311{ 2312 char tmpdigest[TCP_SIGLEN]; 2313 2314 if (tcp_sig_checksigs == 0) 2315 return (1); 2316 if ((tcpbflag & TF_SIGNATURE) == 0) { 2317 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2318 2319 /* 2320 * If this socket is not expecting signature but 2321 * the segment contains signature just fail. 2322 */ 2323 TCPSTAT_INC(tcps_sig_err_sigopt); 2324 TCPSTAT_INC(tcps_sig_rcvbadsig); 2325 return (0); 2326 } 2327 2328 /* Signature is not expected, and not present in segment. */ 2329 return (1); 2330 } 2331 2332 /* 2333 * If this socket is expecting signature but the segment does not 2334 * contain any just fail. 2335 */ 2336 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2337 TCPSTAT_INC(tcps_sig_err_nosigopt); 2338 TCPSTAT_INC(tcps_sig_rcvbadsig); 2339 return (0); 2340 } 2341 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2342 IPSEC_DIR_INBOUND) == -1) { 2343 TCPSTAT_INC(tcps_sig_err_buildsig); 2344 TCPSTAT_INC(tcps_sig_rcvbadsig); 2345 return (0); 2346 } 2347 2348 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2349 TCPSTAT_INC(tcps_sig_rcvbadsig); 2350 return (0); 2351 } 2352 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2353 return (1); 2354} 2355#endif /* TCP_SIGNATURE */ 2356 2357static int 2358sysctl_drop(SYSCTL_HANDLER_ARGS) 2359{ 2360 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2361 struct sockaddr_storage addrs[2]; 2362 struct inpcb *inp; 2363 struct tcpcb *tp; 2364 struct tcptw *tw; 2365 struct sockaddr_in *fin, *lin; 2366#ifdef INET6 2367 struct sockaddr_in6 *fin6, *lin6; 2368#endif 2369 int error; 2370 2371 inp = NULL; 2372 fin = lin = NULL; 2373#ifdef INET6 2374 fin6 = lin6 = NULL; 2375#endif 2376 error = 0; 2377 2378 if (req->oldptr != NULL || req->oldlen != 0) 2379 return (EINVAL); 2380 if (req->newptr == NULL) 2381 return (EPERM); 2382 if (req->newlen < sizeof(addrs)) 2383 return (ENOMEM); 2384 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2385 if (error) 2386 return (error); 2387 2388 switch (addrs[0].ss_family) { 2389#ifdef INET6 2390 case AF_INET6: 2391 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2392 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2393 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2394 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2395 return (EINVAL); 2396 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2397 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2398 return (EINVAL); 2399 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2400 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2401 fin = (struct sockaddr_in *)&addrs[0]; 2402 lin = (struct sockaddr_in *)&addrs[1]; 2403 break; 2404 } 2405 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2406 if (error) 2407 return (error); 2408 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2409 if (error) 2410 return (error); 2411 break; 2412#endif 2413#ifdef INET 2414 case AF_INET: 2415 fin = (struct sockaddr_in *)&addrs[0]; 2416 lin = (struct sockaddr_in *)&addrs[1]; 2417 if (fin->sin_len != sizeof(struct sockaddr_in) || 2418 lin->sin_len != sizeof(struct sockaddr_in)) 2419 return (EINVAL); 2420 break; 2421#endif 2422 default: 2423 return (EINVAL); 2424 } 2425 INP_INFO_RLOCK(&V_tcbinfo); 2426 switch (addrs[0].ss_family) { 2427#ifdef INET6 2428 case AF_INET6: 2429 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2430 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2431 INPLOOKUP_WLOCKPCB, NULL); 2432 break; 2433#endif 2434#ifdef INET 2435 case AF_INET: 2436 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2437 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2438 break; 2439#endif 2440 } 2441 if (inp != NULL) { 2442 if (inp->inp_flags & INP_TIMEWAIT) { 2443 /* 2444 * XXXRW: There currently exists a state where an 2445 * inpcb is present, but its timewait state has been 2446 * discarded. For now, don't allow dropping of this 2447 * type of inpcb. 2448 */ 2449 tw = intotw(inp); 2450 if (tw != NULL) 2451 tcp_twclose(tw, 0); 2452 else 2453 INP_WUNLOCK(inp); 2454 } else if (!(inp->inp_flags & INP_DROPPED) && 2455 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2456 tp = intotcpcb(inp); 2457 tp = tcp_drop(tp, ECONNABORTED); 2458 if (tp != NULL) 2459 INP_WUNLOCK(inp); 2460 } else 2461 INP_WUNLOCK(inp); 2462 } else 2463 error = ESRCH; 2464 INP_INFO_RUNLOCK(&V_tcbinfo); 2465 return (error); 2466} 2467 2468SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2469 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2470 0, sysctl_drop, "", "Drop TCP connection"); 2471 2472/* 2473 * Generate a standardized TCP log line for use throughout the 2474 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2475 * allow use in the interrupt context. 2476 * 2477 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2478 * NB: The function may return NULL if memory allocation failed. 2479 * 2480 * Due to header inclusion and ordering limitations the struct ip 2481 * and ip6_hdr pointers have to be passed as void pointers. 2482 */ 2483char * 2484tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2485 const void *ip6hdr) 2486{ 2487 2488 /* Is logging enabled? */ 2489 if (tcp_log_in_vain == 0) 2490 return (NULL); 2491 2492 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2493} 2494 2495char * 2496tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2497 const void *ip6hdr) 2498{ 2499 2500 /* Is logging enabled? */ 2501 if (tcp_log_debug == 0) 2502 return (NULL); 2503 2504 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2505} 2506 2507static char * 2508tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2509 const void *ip6hdr) 2510{ 2511 char *s, *sp; 2512 size_t size; 2513 struct ip *ip; 2514#ifdef INET6 2515 const struct ip6_hdr *ip6; 2516 2517 ip6 = (const struct ip6_hdr *)ip6hdr; 2518#endif /* INET6 */ 2519 ip = (struct ip *)ip4hdr; 2520 2521 /* 2522 * The log line looks like this: 2523 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2524 */ 2525 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2526 sizeof(PRINT_TH_FLAGS) + 1 + 2527#ifdef INET6 2528 2 * INET6_ADDRSTRLEN; 2529#else 2530 2 * INET_ADDRSTRLEN; 2531#endif /* INET6 */ 2532 2533 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2534 if (s == NULL) 2535 return (NULL); 2536 2537 strcat(s, "TCP: ["); 2538 sp = s + strlen(s); 2539 2540 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2541 inet_ntoa_r(inc->inc_faddr, sp); 2542 sp = s + strlen(s); 2543 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2544 sp = s + strlen(s); 2545 inet_ntoa_r(inc->inc_laddr, sp); 2546 sp = s + strlen(s); 2547 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2548#ifdef INET6 2549 } else if (inc) { 2550 ip6_sprintf(sp, &inc->inc6_faddr); 2551 sp = s + strlen(s); 2552 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2553 sp = s + strlen(s); 2554 ip6_sprintf(sp, &inc->inc6_laddr); 2555 sp = s + strlen(s); 2556 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2557 } else if (ip6 && th) { 2558 ip6_sprintf(sp, &ip6->ip6_src); 2559 sp = s + strlen(s); 2560 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2561 sp = s + strlen(s); 2562 ip6_sprintf(sp, &ip6->ip6_dst); 2563 sp = s + strlen(s); 2564 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2565#endif /* INET6 */ 2566#ifdef INET 2567 } else if (ip && th) { 2568 inet_ntoa_r(ip->ip_src, sp); 2569 sp = s + strlen(s); 2570 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2571 sp = s + strlen(s); 2572 inet_ntoa_r(ip->ip_dst, sp); 2573 sp = s + strlen(s); 2574 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2575#endif /* INET */ 2576 } else { 2577 free(s, M_TCPLOG); 2578 return (NULL); 2579 } 2580 sp = s + strlen(s); 2581 if (th) 2582 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2583 if (*(s + size - 1) != '\0') 2584 panic("%s: string too long", __func__); 2585 return (s); 2586} 2587 2588/* 2589 * A subroutine which makes it easy to track TCP state changes with DTrace. 2590 * This function shouldn't be called for t_state initializations that don't 2591 * correspond to actual TCP state transitions. 2592 */ 2593void 2594tcp_state_change(struct tcpcb *tp, int newstate) 2595{ 2596#if defined(KDTRACE_HOOKS) 2597 int pstate = tp->t_state; 2598#endif 2599 2600 tp->t_state = newstate; 2601 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2602} 2603