tcp_subr.c revision 285976
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 285976 2015-07-28 19:58:44Z delphij $"); 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#include <netinet/tcp_fsm.h> 87#include <netinet/tcp_seq.h> 88#include <netinet/tcp_timer.h> 89#include <netinet/tcp_var.h> 90#include <netinet/tcp_syncache.h> 91#ifdef INET6 92#include <netinet6/tcp6_var.h> 93#endif 94#include <netinet/tcpip.h> 95#ifdef TCPDEBUG 96#include <netinet/tcp_debug.h> 97#endif 98#ifdef INET6 99#include <netinet6/ip6protosw.h> 100#endif 101#ifdef TCP_OFFLOAD 102#include <netinet/tcp_offload.h> 103#endif 104 105#ifdef IPSEC 106#include <netipsec/ipsec.h> 107#include <netipsec/xform.h> 108#ifdef INET6 109#include <netipsec/ipsec6.h> 110#endif 111#include <netipsec/key.h> 112#include <sys/syslog.h> 113#endif /*IPSEC*/ 114 115#include <machine/in_cksum.h> 116#include <sys/md5.h> 117 118#include <security/mac/mac_framework.h> 119 120VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 121#ifdef INET6 122VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 123#endif 124 125static int 126sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 127{ 128 int error, new; 129 130 new = V_tcp_mssdflt; 131 error = sysctl_handle_int(oidp, &new, 0, req); 132 if (error == 0 && req->newptr) { 133 if (new < TCP_MINMSS) 134 error = EINVAL; 135 else 136 V_tcp_mssdflt = new; 137 } 138 return (error); 139} 140 141SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 142 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 143 &sysctl_net_inet_tcp_mss_check, "I", 144 "Default TCP Maximum Segment Size"); 145 146#ifdef INET6 147static int 148sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 149{ 150 int error, new; 151 152 new = V_tcp_v6mssdflt; 153 error = sysctl_handle_int(oidp, &new, 0, req); 154 if (error == 0 && req->newptr) { 155 if (new < TCP_MINMSS) 156 error = EINVAL; 157 else 158 V_tcp_v6mssdflt = new; 159 } 160 return (error); 161} 162 163SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 164 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 165 &sysctl_net_inet_tcp_mss_v6_check, "I", 166 "Default TCP Maximum Segment Size for IPv6"); 167#endif /* INET6 */ 168 169/* 170 * Minimum MSS we accept and use. This prevents DoS attacks where 171 * we are forced to a ridiculous low MSS like 20 and send hundreds 172 * of packets instead of one. The effect scales with the available 173 * bandwidth and quickly saturates the CPU and network interface 174 * with packet generation and sending. Set to zero to disable MINMSS 175 * checking. This setting prevents us from sending too small packets. 176 */ 177VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 178SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 179 &VNET_NAME(tcp_minmss), 0, 180 "Minimum TCP Maximum Segment Size"); 181 182VNET_DEFINE(int, tcp_do_rfc1323) = 1; 183SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 184 &VNET_NAME(tcp_do_rfc1323), 0, 185 "Enable rfc1323 (high performance TCP) extensions"); 186 187static int tcp_log_debug = 0; 188SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 189 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 190 191static int tcp_tcbhashsize = 0; 192SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 193 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 194 195static int do_tcpdrain = 1; 196SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 197 "Enable tcp_drain routine for extra help when low on mbufs"); 198 199SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 200 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 201 202static VNET_DEFINE(int, icmp_may_rst) = 1; 203#define V_icmp_may_rst VNET(icmp_may_rst) 204SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, 205 &VNET_NAME(icmp_may_rst), 0, 206 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 207 208static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 209#define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 210SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 211 &VNET_NAME(tcp_isn_reseed_interval), 0, 212 "Seconds between reseeding of ISN secret"); 213 214static int tcp_soreceive_stream = 0; 215SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 216 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 217 218#ifdef TCP_SIGNATURE 219static int tcp_sig_checksigs = 1; 220SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 221 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 222#endif 223 224VNET_DEFINE(uma_zone_t, sack_hole_zone); 225#define V_sack_hole_zone VNET(sack_hole_zone) 226 227VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 228 229static struct inpcb *tcp_notify(struct inpcb *, int); 230static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 231static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 232 void *ip4hdr, const void *ip6hdr); 233static void tcp_timer_discard(struct tcpcb *, uint32_t); 234 235/* 236 * Target size of TCP PCB hash tables. Must be a power of two. 237 * 238 * Note that this can be overridden by the kernel environment 239 * variable net.inet.tcp.tcbhashsize 240 */ 241#ifndef TCBHASHSIZE 242#define TCBHASHSIZE 0 243#endif 244 245/* 246 * XXX 247 * Callouts should be moved into struct tcp directly. They are currently 248 * separate because the tcpcb structure is exported to userland for sysctl 249 * parsing purposes, which do not know about callouts. 250 */ 251struct tcpcb_mem { 252 struct tcpcb tcb; 253 struct tcp_timer tt; 254 struct cc_var ccv; 255 struct osd osd; 256}; 257 258static VNET_DEFINE(uma_zone_t, tcpcb_zone); 259#define V_tcpcb_zone VNET(tcpcb_zone) 260 261MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 262static struct mtx isn_mtx; 263 264#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 265#define ISN_LOCK() mtx_lock(&isn_mtx) 266#define ISN_UNLOCK() mtx_unlock(&isn_mtx) 267 268/* 269 * TCP initialization. 270 */ 271static void 272tcp_zone_change(void *tag) 273{ 274 275 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 276 uma_zone_set_max(V_tcpcb_zone, maxsockets); 277 tcp_tw_zone_change(); 278} 279 280static int 281tcp_inpcb_init(void *mem, int size, int flags) 282{ 283 struct inpcb *inp = mem; 284 285 INP_LOCK_INIT(inp, "inp", "tcpinp"); 286 return (0); 287} 288 289/* 290 * Take a value and get the next power of 2 that doesn't overflow. 291 * Used to size the tcp_inpcb hash buckets. 292 */ 293static int 294maketcp_hashsize(int size) 295{ 296 int hashsize; 297 298 /* 299 * auto tune. 300 * get the next power of 2 higher than maxsockets. 301 */ 302 hashsize = 1 << fls(size); 303 /* catch overflow, and just go one power of 2 smaller */ 304 if (hashsize < size) { 305 hashsize = 1 << (fls(size) - 1); 306 } 307 return (hashsize); 308} 309 310void 311tcp_init(void) 312{ 313 const char *tcbhash_tuneable; 314 int hashsize; 315 316 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 317 318 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 319 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 320 printf("%s: WARNING: unable to register helper hook\n", __func__); 321 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 322 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 323 printf("%s: WARNING: unable to register helper hook\n", __func__); 324 325 hashsize = TCBHASHSIZE; 326 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 327 if (hashsize == 0) { 328 /* 329 * Auto tune the hash size based on maxsockets. 330 * A perfect hash would have a 1:1 mapping 331 * (hashsize = maxsockets) however it's been 332 * suggested that O(2) average is better. 333 */ 334 hashsize = maketcp_hashsize(maxsockets / 4); 335 /* 336 * Our historical default is 512, 337 * do not autotune lower than this. 338 */ 339 if (hashsize < 512) 340 hashsize = 512; 341 if (bootverbose) 342 printf("%s: %s auto tuned to %d\n", __func__, 343 tcbhash_tuneable, hashsize); 344 } 345 /* 346 * We require a hashsize to be a power of two. 347 * Previously if it was not a power of two we would just reset it 348 * back to 512, which could be a nasty surprise if you did not notice 349 * the error message. 350 * Instead what we do is clip it to the closest power of two lower 351 * than the specified hash value. 352 */ 353 if (!powerof2(hashsize)) { 354 int oldhashsize = hashsize; 355 356 hashsize = maketcp_hashsize(hashsize); 357 /* prevent absurdly low value */ 358 if (hashsize < 16) 359 hashsize = 16; 360 printf("%s: WARNING: TCB hash size not a power of 2, " 361 "clipped from %d to %d.\n", __func__, oldhashsize, 362 hashsize); 363 } 364 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 365 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 366 IPI_HASHFIELDS_4TUPLE); 367 368 /* 369 * These have to be type stable for the benefit of the timers. 370 */ 371 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 372 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 373 uma_zone_set_max(V_tcpcb_zone, maxsockets); 374 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 375 376 tcp_tw_init(); 377 syncache_init(); 378 tcp_hc_init(); 379 380 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 381 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 382 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 383 384 /* Skip initialization of globals for non-default instances. */ 385 if (!IS_DEFAULT_VNET(curvnet)) 386 return; 387 388 tcp_reass_global_init(); 389 390 /* XXX virtualize those bellow? */ 391 tcp_delacktime = TCPTV_DELACK; 392 tcp_keepinit = TCPTV_KEEP_INIT; 393 tcp_keepidle = TCPTV_KEEP_IDLE; 394 tcp_keepintvl = TCPTV_KEEPINTVL; 395 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 396 tcp_msl = TCPTV_MSL; 397 tcp_rexmit_min = TCPTV_MIN; 398 if (tcp_rexmit_min < 1) 399 tcp_rexmit_min = 1; 400 tcp_rexmit_slop = TCPTV_CPU_VAR; 401 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 402 tcp_tcbhashsize = hashsize; 403 404 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 405 if (tcp_soreceive_stream) { 406#ifdef INET 407 tcp_usrreqs.pru_soreceive = soreceive_stream; 408#endif 409#ifdef INET6 410 tcp6_usrreqs.pru_soreceive = soreceive_stream; 411#endif /* INET6 */ 412 } 413 414#ifdef INET6 415#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 416#else /* INET6 */ 417#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 418#endif /* INET6 */ 419 if (max_protohdr < TCP_MINPROTOHDR) 420 max_protohdr = TCP_MINPROTOHDR; 421 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 422 panic("tcp_init"); 423#undef TCP_MINPROTOHDR 424 425 ISN_LOCK_INIT(); 426 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 427 SHUTDOWN_PRI_DEFAULT); 428 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 429 EVENTHANDLER_PRI_ANY); 430} 431 432#ifdef VIMAGE 433void 434tcp_destroy(void) 435{ 436 437 tcp_hc_destroy(); 438 syncache_destroy(); 439 tcp_tw_destroy(); 440 in_pcbinfo_destroy(&V_tcbinfo); 441 uma_zdestroy(V_sack_hole_zone); 442 uma_zdestroy(V_tcpcb_zone); 443} 444#endif 445 446void 447tcp_fini(void *xtp) 448{ 449 450} 451 452/* 453 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 454 * tcp_template used to store this data in mbufs, but we now recopy it out 455 * of the tcpcb each time to conserve mbufs. 456 */ 457void 458tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 459{ 460 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 461 462 INP_WLOCK_ASSERT(inp); 463 464#ifdef INET6 465 if ((inp->inp_vflag & INP_IPV6) != 0) { 466 struct ip6_hdr *ip6; 467 468 ip6 = (struct ip6_hdr *)ip_ptr; 469 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 470 (inp->inp_flow & IPV6_FLOWINFO_MASK); 471 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 472 (IPV6_VERSION & IPV6_VERSION_MASK); 473 ip6->ip6_nxt = IPPROTO_TCP; 474 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 475 ip6->ip6_src = inp->in6p_laddr; 476 ip6->ip6_dst = inp->in6p_faddr; 477 } 478#endif /* INET6 */ 479#if defined(INET6) && defined(INET) 480 else 481#endif 482#ifdef INET 483 { 484 struct ip *ip; 485 486 ip = (struct ip *)ip_ptr; 487 ip->ip_v = IPVERSION; 488 ip->ip_hl = 5; 489 ip->ip_tos = inp->inp_ip_tos; 490 ip->ip_len = 0; 491 ip->ip_id = 0; 492 ip->ip_off = 0; 493 ip->ip_ttl = inp->inp_ip_ttl; 494 ip->ip_sum = 0; 495 ip->ip_p = IPPROTO_TCP; 496 ip->ip_src = inp->inp_laddr; 497 ip->ip_dst = inp->inp_faddr; 498 } 499#endif /* INET */ 500 th->th_sport = inp->inp_lport; 501 th->th_dport = inp->inp_fport; 502 th->th_seq = 0; 503 th->th_ack = 0; 504 th->th_x2 = 0; 505 th->th_off = 5; 506 th->th_flags = 0; 507 th->th_win = 0; 508 th->th_urp = 0; 509 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 510} 511 512/* 513 * Create template to be used to send tcp packets on a connection. 514 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 515 * use for this function is in keepalives, which use tcp_respond. 516 */ 517struct tcptemp * 518tcpip_maketemplate(struct inpcb *inp) 519{ 520 struct tcptemp *t; 521 522 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 523 if (t == NULL) 524 return (NULL); 525 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 526 return (t); 527} 528 529/* 530 * Send a single message to the TCP at address specified by 531 * the given TCP/IP header. If m == NULL, then we make a copy 532 * of the tcpiphdr at ti and send directly to the addressed host. 533 * This is used to force keep alive messages out using the TCP 534 * template for a connection. If flags are given then we send 535 * a message back to the TCP which originated the * segment ti, 536 * and discard the mbuf containing it and any other attached mbufs. 537 * 538 * In any case the ack and sequence number of the transmitted 539 * segment are as specified by the parameters. 540 * 541 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 542 */ 543void 544tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 545 tcp_seq ack, tcp_seq seq, int flags) 546{ 547 int tlen; 548 int win = 0; 549 struct ip *ip; 550 struct tcphdr *nth; 551#ifdef INET6 552 struct ip6_hdr *ip6; 553 int isipv6; 554#endif /* INET6 */ 555 int ipflags = 0; 556 struct inpcb *inp; 557 558 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 559 560#ifdef INET6 561 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 562 ip6 = ipgen; 563#endif /* INET6 */ 564 ip = ipgen; 565 566 if (tp != NULL) { 567 inp = tp->t_inpcb; 568 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 569 INP_WLOCK_ASSERT(inp); 570 } else 571 inp = NULL; 572 573 if (tp != NULL) { 574 if (!(flags & TH_RST)) { 575 win = sbspace(&inp->inp_socket->so_rcv); 576 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 577 win = (long)TCP_MAXWIN << tp->rcv_scale; 578 } 579 } 580 if (m == NULL) { 581 m = m_gethdr(M_NOWAIT, MT_DATA); 582 if (m == NULL) 583 return; 584 tlen = 0; 585 m->m_data += max_linkhdr; 586#ifdef INET6 587 if (isipv6) { 588 bcopy((caddr_t)ip6, mtod(m, caddr_t), 589 sizeof(struct ip6_hdr)); 590 ip6 = mtod(m, struct ip6_hdr *); 591 nth = (struct tcphdr *)(ip6 + 1); 592 } else 593#endif /* INET6 */ 594 { 595 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 596 ip = mtod(m, struct ip *); 597 nth = (struct tcphdr *)(ip + 1); 598 } 599 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 600 flags = TH_ACK; 601 } else { 602 /* 603 * reuse the mbuf. 604 * XXX MRT We inherrit the FIB, which is lucky. 605 */ 606 m_freem(m->m_next); 607 m->m_next = NULL; 608 m->m_data = (caddr_t)ipgen; 609 /* m_len is set later */ 610 tlen = 0; 611#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 612#ifdef INET6 613 if (isipv6) { 614 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 615 nth = (struct tcphdr *)(ip6 + 1); 616 } else 617#endif /* INET6 */ 618 { 619 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 620 nth = (struct tcphdr *)(ip + 1); 621 } 622 if (th != nth) { 623 /* 624 * this is usually a case when an extension header 625 * exists between the IPv6 header and the 626 * TCP header. 627 */ 628 nth->th_sport = th->th_sport; 629 nth->th_dport = th->th_dport; 630 } 631 xchg(nth->th_dport, nth->th_sport, uint16_t); 632#undef xchg 633 } 634#ifdef INET6 635 if (isipv6) { 636 ip6->ip6_flow = 0; 637 ip6->ip6_vfc = IPV6_VERSION; 638 ip6->ip6_nxt = IPPROTO_TCP; 639 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 640 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 641 } 642#endif 643#if defined(INET) && defined(INET6) 644 else 645#endif 646#ifdef INET 647 { 648 tlen += sizeof (struct tcpiphdr); 649 ip->ip_len = htons(tlen); 650 ip->ip_ttl = V_ip_defttl; 651 if (V_path_mtu_discovery) 652 ip->ip_off |= htons(IP_DF); 653 } 654#endif 655 m->m_len = tlen; 656 m->m_pkthdr.len = tlen; 657 m->m_pkthdr.rcvif = NULL; 658#ifdef MAC 659 if (inp != NULL) { 660 /* 661 * Packet is associated with a socket, so allow the 662 * label of the response to reflect the socket label. 663 */ 664 INP_WLOCK_ASSERT(inp); 665 mac_inpcb_create_mbuf(inp, m); 666 } else { 667 /* 668 * Packet is not associated with a socket, so possibly 669 * update the label in place. 670 */ 671 mac_netinet_tcp_reply(m); 672 } 673#endif 674 nth->th_seq = htonl(seq); 675 nth->th_ack = htonl(ack); 676 nth->th_x2 = 0; 677 nth->th_off = sizeof (struct tcphdr) >> 2; 678 nth->th_flags = flags; 679 if (tp != NULL) 680 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 681 else 682 nth->th_win = htons((u_short)win); 683 nth->th_urp = 0; 684 685 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 686#ifdef INET6 687 if (isipv6) { 688 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 689 nth->th_sum = in6_cksum_pseudo(ip6, 690 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 691 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 692 NULL, NULL); 693 } 694#endif /* INET6 */ 695#if defined(INET6) && defined(INET) 696 else 697#endif 698#ifdef INET 699 { 700 m->m_pkthdr.csum_flags = CSUM_TCP; 701 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 702 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 703 } 704#endif /* INET */ 705#ifdef TCPDEBUG 706 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 707 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 708#endif 709 if (flags & TH_RST) 710 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 711 tp, nth); 712 713 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 714#ifdef INET6 715 if (isipv6) 716 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 717#endif /* INET6 */ 718#if defined(INET) && defined(INET6) 719 else 720#endif 721#ifdef INET 722 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 723#endif 724} 725 726/* 727 * Create a new TCP control block, making an 728 * empty reassembly queue and hooking it to the argument 729 * protocol control block. The `inp' parameter must have 730 * come from the zone allocator set up in tcp_init(). 731 */ 732struct tcpcb * 733tcp_newtcpcb(struct inpcb *inp) 734{ 735 struct tcpcb_mem *tm; 736 struct tcpcb *tp; 737#ifdef INET6 738 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 739#endif /* INET6 */ 740 741 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 742 if (tm == NULL) 743 return (NULL); 744 tp = &tm->tcb; 745 746 /* Initialise cc_var struct for this tcpcb. */ 747 tp->ccv = &tm->ccv; 748 tp->ccv->type = IPPROTO_TCP; 749 tp->ccv->ccvc.tcp = tp; 750 751 /* 752 * Use the current system default CC algorithm. 753 */ 754 CC_LIST_RLOCK(); 755 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 756 CC_ALGO(tp) = CC_DEFAULT(); 757 CC_LIST_RUNLOCK(); 758 759 if (CC_ALGO(tp)->cb_init != NULL) 760 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 761 uma_zfree(V_tcpcb_zone, tm); 762 return (NULL); 763 } 764 765 tp->osd = &tm->osd; 766 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 767 uma_zfree(V_tcpcb_zone, tm); 768 return (NULL); 769 } 770 771#ifdef VIMAGE 772 tp->t_vnet = inp->inp_vnet; 773#endif 774 tp->t_timers = &tm->tt; 775 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 776 tp->t_maxseg = tp->t_maxopd = 777#ifdef INET6 778 isipv6 ? V_tcp_v6mssdflt : 779#endif /* INET6 */ 780 V_tcp_mssdflt; 781 782 /* Set up our timeouts. */ 783 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 784 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 785 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 786 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 787 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 788 789 if (V_tcp_do_rfc1323) 790 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 791 if (V_tcp_do_sack) 792 tp->t_flags |= TF_SACK_PERMIT; 793 TAILQ_INIT(&tp->snd_holes); 794 /* 795 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 796 * is called. 797 */ 798 in_pcbref(inp); /* Reference for tcpcb */ 799 tp->t_inpcb = inp; 800 801 /* 802 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 803 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 804 * reasonable initial retransmit time. 805 */ 806 tp->t_srtt = TCPTV_SRTTBASE; 807 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 808 tp->t_rttmin = tcp_rexmit_min; 809 tp->t_rxtcur = TCPTV_RTOBASE; 810 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 811 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 812 tp->t_rcvtime = ticks; 813 /* 814 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 815 * because the socket may be bound to an IPv6 wildcard address, 816 * which may match an IPv4-mapped IPv6 address. 817 */ 818 inp->inp_ip_ttl = V_ip_defttl; 819 inp->inp_ppcb = tp; 820 return (tp); /* XXX */ 821} 822 823/* 824 * Switch the congestion control algorithm back to NewReno for any active 825 * control blocks using an algorithm which is about to go away. 826 * This ensures the CC framework can allow the unload to proceed without leaving 827 * any dangling pointers which would trigger a panic. 828 * Returning non-zero would inform the CC framework that something went wrong 829 * and it would be unsafe to allow the unload to proceed. However, there is no 830 * way for this to occur with this implementation so we always return zero. 831 */ 832int 833tcp_ccalgounload(struct cc_algo *unload_algo) 834{ 835 struct cc_algo *tmpalgo; 836 struct inpcb *inp; 837 struct tcpcb *tp; 838 VNET_ITERATOR_DECL(vnet_iter); 839 840 /* 841 * Check all active control blocks across all network stacks and change 842 * any that are using "unload_algo" back to NewReno. If "unload_algo" 843 * requires cleanup code to be run, call it. 844 */ 845 VNET_LIST_RLOCK(); 846 VNET_FOREACH(vnet_iter) { 847 CURVNET_SET(vnet_iter); 848 INP_INFO_RLOCK(&V_tcbinfo); 849 /* 850 * New connections already part way through being initialised 851 * with the CC algo we're removing will not race with this code 852 * because the INP_INFO_WLOCK is held during initialisation. We 853 * therefore don't enter the loop below until the connection 854 * list has stabilised. 855 */ 856 LIST_FOREACH(inp, &V_tcb, inp_list) { 857 INP_WLOCK(inp); 858 /* Important to skip tcptw structs. */ 859 if (!(inp->inp_flags & INP_TIMEWAIT) && 860 (tp = intotcpcb(inp)) != NULL) { 861 /* 862 * By holding INP_WLOCK here, we are assured 863 * that the connection is not currently 864 * executing inside the CC module's functions 865 * i.e. it is safe to make the switch back to 866 * NewReno. 867 */ 868 if (CC_ALGO(tp) == unload_algo) { 869 tmpalgo = CC_ALGO(tp); 870 /* NewReno does not require any init. */ 871 CC_ALGO(tp) = &newreno_cc_algo; 872 if (tmpalgo->cb_destroy != NULL) 873 tmpalgo->cb_destroy(tp->ccv); 874 } 875 } 876 INP_WUNLOCK(inp); 877 } 878 INP_INFO_RUNLOCK(&V_tcbinfo); 879 CURVNET_RESTORE(); 880 } 881 VNET_LIST_RUNLOCK(); 882 883 return (0); 884} 885 886/* 887 * Drop a TCP connection, reporting 888 * the specified error. If connection is synchronized, 889 * then send a RST to peer. 890 */ 891struct tcpcb * 892tcp_drop(struct tcpcb *tp, int errno) 893{ 894 struct socket *so = tp->t_inpcb->inp_socket; 895 896 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 897 INP_WLOCK_ASSERT(tp->t_inpcb); 898 899 if (TCPS_HAVERCVDSYN(tp->t_state)) { 900 tcp_state_change(tp, TCPS_CLOSED); 901 (void) tcp_output(tp); 902 TCPSTAT_INC(tcps_drops); 903 } else 904 TCPSTAT_INC(tcps_conndrops); 905 if (errno == ETIMEDOUT && tp->t_softerror) 906 errno = tp->t_softerror; 907 so->so_error = errno; 908 return (tcp_close(tp)); 909} 910 911void 912tcp_discardcb(struct tcpcb *tp) 913{ 914 struct inpcb *inp = tp->t_inpcb; 915 struct socket *so = inp->inp_socket; 916#ifdef INET6 917 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 918#endif /* INET6 */ 919 int released; 920 921 INP_WLOCK_ASSERT(inp); 922 923 /* 924 * Make sure that all of our timers are stopped before we delete the 925 * PCB. 926 * 927 * If stopping a timer fails, we schedule a discard function in same 928 * callout, and the last discard function called will take care of 929 * deleting the tcpcb. 930 */ 931 tcp_timer_stop(tp, TT_REXMT); 932 tcp_timer_stop(tp, TT_PERSIST); 933 tcp_timer_stop(tp, TT_KEEP); 934 tcp_timer_stop(tp, TT_2MSL); 935 tcp_timer_stop(tp, TT_DELACK); 936 937 /* 938 * If we got enough samples through the srtt filter, 939 * save the rtt and rttvar in the routing entry. 940 * 'Enough' is arbitrarily defined as 4 rtt samples. 941 * 4 samples is enough for the srtt filter to converge 942 * to within enough % of the correct value; fewer samples 943 * and we could save a bogus rtt. The danger is not high 944 * as tcp quickly recovers from everything. 945 * XXX: Works very well but needs some more statistics! 946 */ 947 if (tp->t_rttupdated >= 4) { 948 struct hc_metrics_lite metrics; 949 u_long ssthresh; 950 951 bzero(&metrics, sizeof(metrics)); 952 /* 953 * Update the ssthresh always when the conditions below 954 * are satisfied. This gives us better new start value 955 * for the congestion avoidance for new connections. 956 * ssthresh is only set if packet loss occured on a session. 957 * 958 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 959 * being torn down. Ideally this code would not use 'so'. 960 */ 961 ssthresh = tp->snd_ssthresh; 962 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 963 /* 964 * convert the limit from user data bytes to 965 * packets then to packet data bytes. 966 */ 967 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 968 if (ssthresh < 2) 969 ssthresh = 2; 970 ssthresh *= (u_long)(tp->t_maxseg + 971#ifdef INET6 972 (isipv6 ? sizeof (struct ip6_hdr) + 973 sizeof (struct tcphdr) : 974#endif 975 sizeof (struct tcpiphdr) 976#ifdef INET6 977 ) 978#endif 979 ); 980 } else 981 ssthresh = 0; 982 metrics.rmx_ssthresh = ssthresh; 983 984 metrics.rmx_rtt = tp->t_srtt; 985 metrics.rmx_rttvar = tp->t_rttvar; 986 metrics.rmx_cwnd = tp->snd_cwnd; 987 metrics.rmx_sendpipe = 0; 988 metrics.rmx_recvpipe = 0; 989 990 tcp_hc_update(&inp->inp_inc, &metrics); 991 } 992 993 /* free the reassembly queue, if any */ 994 tcp_reass_flush(tp); 995 996#ifdef TCP_OFFLOAD 997 /* Disconnect offload device, if any. */ 998 if (tp->t_flags & TF_TOE) 999 tcp_offload_detach(tp); 1000#endif 1001 1002 tcp_free_sackholes(tp); 1003 1004 /* Allow the CC algorithm to clean up after itself. */ 1005 if (CC_ALGO(tp)->cb_destroy != NULL) 1006 CC_ALGO(tp)->cb_destroy(tp->ccv); 1007 1008 khelp_destroy_osd(tp->osd); 1009 1010 CC_ALGO(tp) = NULL; 1011 inp->inp_ppcb = NULL; 1012 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1013 /* We own the last reference on tcpcb, let's free it. */ 1014 tp->t_inpcb = NULL; 1015 uma_zfree(V_tcpcb_zone, tp); 1016 released = in_pcbrele_wlocked(inp); 1017 KASSERT(!released, ("%s: inp %p should not have been released " 1018 "here", __func__, inp)); 1019 } 1020} 1021 1022void 1023tcp_timer_2msl_discard(void *xtp) 1024{ 1025 1026 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1027} 1028 1029void 1030tcp_timer_keep_discard(void *xtp) 1031{ 1032 1033 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1034} 1035 1036void 1037tcp_timer_persist_discard(void *xtp) 1038{ 1039 1040 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1041} 1042 1043void 1044tcp_timer_rexmt_discard(void *xtp) 1045{ 1046 1047 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1048} 1049 1050void 1051tcp_timer_delack_discard(void *xtp) 1052{ 1053 1054 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1055} 1056 1057void 1058tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1059{ 1060 struct inpcb *inp; 1061 1062 CURVNET_SET(tp->t_vnet); 1063 INP_INFO_WLOCK(&V_tcbinfo); 1064 inp = tp->t_inpcb; 1065 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1066 __func__, tp)); 1067 INP_WLOCK(inp); 1068 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1069 ("%s: tcpcb has to be stopped here", __func__)); 1070 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1071 ("%s: discard callout should be running", __func__)); 1072 tp->t_timers->tt_flags &= ~timer_type; 1073 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1074 /* We own the last reference on this tcpcb, let's free it. */ 1075 tp->t_inpcb = NULL; 1076 uma_zfree(V_tcpcb_zone, tp); 1077 if (in_pcbrele_wlocked(inp)) { 1078 INP_INFO_WUNLOCK(&V_tcbinfo); 1079 CURVNET_RESTORE(); 1080 return; 1081 } 1082 } 1083 INP_WUNLOCK(inp); 1084 INP_INFO_WUNLOCK(&V_tcbinfo); 1085 CURVNET_RESTORE(); 1086} 1087 1088/* 1089 * Attempt to close a TCP control block, marking it as dropped, and freeing 1090 * the socket if we hold the only reference. 1091 */ 1092struct tcpcb * 1093tcp_close(struct tcpcb *tp) 1094{ 1095 struct inpcb *inp = tp->t_inpcb; 1096 struct socket *so; 1097 1098 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1099 INP_WLOCK_ASSERT(inp); 1100 1101#ifdef TCP_OFFLOAD 1102 if (tp->t_state == TCPS_LISTEN) 1103 tcp_offload_listen_stop(tp); 1104#endif 1105 in_pcbdrop(inp); 1106 TCPSTAT_INC(tcps_closed); 1107 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1108 so = inp->inp_socket; 1109 soisdisconnected(so); 1110 if (inp->inp_flags & INP_SOCKREF) { 1111 KASSERT(so->so_state & SS_PROTOREF, 1112 ("tcp_close: !SS_PROTOREF")); 1113 inp->inp_flags &= ~INP_SOCKREF; 1114 INP_WUNLOCK(inp); 1115 ACCEPT_LOCK(); 1116 SOCK_LOCK(so); 1117 so->so_state &= ~SS_PROTOREF; 1118 sofree(so); 1119 return (NULL); 1120 } 1121 return (tp); 1122} 1123 1124void 1125tcp_drain(void) 1126{ 1127 VNET_ITERATOR_DECL(vnet_iter); 1128 1129 if (!do_tcpdrain) 1130 return; 1131 1132 VNET_LIST_RLOCK_NOSLEEP(); 1133 VNET_FOREACH(vnet_iter) { 1134 CURVNET_SET(vnet_iter); 1135 struct inpcb *inpb; 1136 struct tcpcb *tcpb; 1137 1138 /* 1139 * Walk the tcpbs, if existing, and flush the reassembly queue, 1140 * if there is one... 1141 * XXX: The "Net/3" implementation doesn't imply that the TCP 1142 * reassembly queue should be flushed, but in a situation 1143 * where we're really low on mbufs, this is potentially 1144 * useful. 1145 */ 1146 INP_INFO_RLOCK(&V_tcbinfo); 1147 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1148 if (inpb->inp_flags & INP_TIMEWAIT) 1149 continue; 1150 INP_WLOCK(inpb); 1151 if ((tcpb = intotcpcb(inpb)) != NULL) { 1152 tcp_reass_flush(tcpb); 1153 tcp_clean_sackreport(tcpb); 1154 } 1155 INP_WUNLOCK(inpb); 1156 } 1157 INP_INFO_RUNLOCK(&V_tcbinfo); 1158 CURVNET_RESTORE(); 1159 } 1160 VNET_LIST_RUNLOCK_NOSLEEP(); 1161} 1162 1163/* 1164 * Notify a tcp user of an asynchronous error; 1165 * store error as soft error, but wake up user 1166 * (for now, won't do anything until can select for soft error). 1167 * 1168 * Do not wake up user since there currently is no mechanism for 1169 * reporting soft errors (yet - a kqueue filter may be added). 1170 */ 1171static struct inpcb * 1172tcp_notify(struct inpcb *inp, int error) 1173{ 1174 struct tcpcb *tp; 1175 1176 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1177 INP_WLOCK_ASSERT(inp); 1178 1179 if ((inp->inp_flags & INP_TIMEWAIT) || 1180 (inp->inp_flags & INP_DROPPED)) 1181 return (inp); 1182 1183 tp = intotcpcb(inp); 1184 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1185 1186 /* 1187 * Ignore some errors if we are hooked up. 1188 * If connection hasn't completed, has retransmitted several times, 1189 * and receives a second error, give up now. This is better 1190 * than waiting a long time to establish a connection that 1191 * can never complete. 1192 */ 1193 if (tp->t_state == TCPS_ESTABLISHED && 1194 (error == EHOSTUNREACH || error == ENETUNREACH || 1195 error == EHOSTDOWN)) { 1196 return (inp); 1197 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1198 tp->t_softerror) { 1199 tp = tcp_drop(tp, error); 1200 if (tp != NULL) 1201 return (inp); 1202 else 1203 return (NULL); 1204 } else { 1205 tp->t_softerror = error; 1206 return (inp); 1207 } 1208#if 0 1209 wakeup( &so->so_timeo); 1210 sorwakeup(so); 1211 sowwakeup(so); 1212#endif 1213} 1214 1215static int 1216tcp_pcblist(SYSCTL_HANDLER_ARGS) 1217{ 1218 int error, i, m, n, pcb_count; 1219 struct inpcb *inp, **inp_list; 1220 inp_gen_t gencnt; 1221 struct xinpgen xig; 1222 1223 /* 1224 * The process of preparing the TCB list is too time-consuming and 1225 * resource-intensive to repeat twice on every request. 1226 */ 1227 if (req->oldptr == NULL) { 1228 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1229 n += imax(n / 8, 10); 1230 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1231 return (0); 1232 } 1233 1234 if (req->newptr != NULL) 1235 return (EPERM); 1236 1237 /* 1238 * OK, now we're committed to doing something. 1239 */ 1240 INP_INFO_RLOCK(&V_tcbinfo); 1241 gencnt = V_tcbinfo.ipi_gencnt; 1242 n = V_tcbinfo.ipi_count; 1243 INP_INFO_RUNLOCK(&V_tcbinfo); 1244 1245 m = syncache_pcbcount(); 1246 1247 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1248 + (n + m) * sizeof(struct xtcpcb)); 1249 if (error != 0) 1250 return (error); 1251 1252 xig.xig_len = sizeof xig; 1253 xig.xig_count = n + m; 1254 xig.xig_gen = gencnt; 1255 xig.xig_sogen = so_gencnt; 1256 error = SYSCTL_OUT(req, &xig, sizeof xig); 1257 if (error) 1258 return (error); 1259 1260 error = syncache_pcblist(req, m, &pcb_count); 1261 if (error) 1262 return (error); 1263 1264 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1265 if (inp_list == NULL) 1266 return (ENOMEM); 1267 1268 INP_INFO_RLOCK(&V_tcbinfo); 1269 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1270 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1271 INP_WLOCK(inp); 1272 if (inp->inp_gencnt <= gencnt) { 1273 /* 1274 * XXX: This use of cr_cansee(), introduced with 1275 * TCP state changes, is not quite right, but for 1276 * now, better than nothing. 1277 */ 1278 if (inp->inp_flags & INP_TIMEWAIT) { 1279 if (intotw(inp) != NULL) 1280 error = cr_cansee(req->td->td_ucred, 1281 intotw(inp)->tw_cred); 1282 else 1283 error = EINVAL; /* Skip this inp. */ 1284 } else 1285 error = cr_canseeinpcb(req->td->td_ucred, inp); 1286 if (error == 0) { 1287 in_pcbref(inp); 1288 inp_list[i++] = inp; 1289 } 1290 } 1291 INP_WUNLOCK(inp); 1292 } 1293 INP_INFO_RUNLOCK(&V_tcbinfo); 1294 n = i; 1295 1296 error = 0; 1297 for (i = 0; i < n; i++) { 1298 inp = inp_list[i]; 1299 INP_RLOCK(inp); 1300 if (inp->inp_gencnt <= gencnt) { 1301 struct xtcpcb xt; 1302 void *inp_ppcb; 1303 1304 bzero(&xt, sizeof(xt)); 1305 xt.xt_len = sizeof xt; 1306 /* XXX should avoid extra copy */ 1307 bcopy(inp, &xt.xt_inp, sizeof *inp); 1308 inp_ppcb = inp->inp_ppcb; 1309 if (inp_ppcb == NULL) 1310 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1311 else if (inp->inp_flags & INP_TIMEWAIT) { 1312 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1313 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1314 } else { 1315 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1316 if (xt.xt_tp.t_timers) 1317 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1318 } 1319 if (inp->inp_socket != NULL) 1320 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1321 else { 1322 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1323 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1324 } 1325 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1326 INP_RUNLOCK(inp); 1327 error = SYSCTL_OUT(req, &xt, sizeof xt); 1328 } else 1329 INP_RUNLOCK(inp); 1330 } 1331 INP_INFO_WLOCK(&V_tcbinfo); 1332 for (i = 0; i < n; i++) { 1333 inp = inp_list[i]; 1334 INP_RLOCK(inp); 1335 if (!in_pcbrele_rlocked(inp)) 1336 INP_RUNLOCK(inp); 1337 } 1338 INP_INFO_WUNLOCK(&V_tcbinfo); 1339 1340 if (!error) { 1341 /* 1342 * Give the user an updated idea of our state. 1343 * If the generation differs from what we told 1344 * her before, she knows that something happened 1345 * while we were processing this request, and it 1346 * might be necessary to retry. 1347 */ 1348 INP_INFO_RLOCK(&V_tcbinfo); 1349 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1350 xig.xig_sogen = so_gencnt; 1351 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1352 INP_INFO_RUNLOCK(&V_tcbinfo); 1353 error = SYSCTL_OUT(req, &xig, sizeof xig); 1354 } 1355 free(inp_list, M_TEMP); 1356 return (error); 1357} 1358 1359SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1360 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1361 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1362 1363#ifdef INET 1364static int 1365tcp_getcred(SYSCTL_HANDLER_ARGS) 1366{ 1367 struct xucred xuc; 1368 struct sockaddr_in addrs[2]; 1369 struct inpcb *inp; 1370 int error; 1371 1372 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1373 if (error) 1374 return (error); 1375 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1376 if (error) 1377 return (error); 1378 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1379 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1380 if (inp != NULL) { 1381 if (inp->inp_socket == NULL) 1382 error = ENOENT; 1383 if (error == 0) 1384 error = cr_canseeinpcb(req->td->td_ucred, inp); 1385 if (error == 0) 1386 cru2x(inp->inp_cred, &xuc); 1387 INP_RUNLOCK(inp); 1388 } else 1389 error = ENOENT; 1390 if (error == 0) 1391 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1392 return (error); 1393} 1394 1395SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1396 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1397 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1398#endif /* INET */ 1399 1400#ifdef INET6 1401static int 1402tcp6_getcred(SYSCTL_HANDLER_ARGS) 1403{ 1404 struct xucred xuc; 1405 struct sockaddr_in6 addrs[2]; 1406 struct inpcb *inp; 1407 int error; 1408#ifdef INET 1409 int mapped = 0; 1410#endif 1411 1412 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1413 if (error) 1414 return (error); 1415 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1416 if (error) 1417 return (error); 1418 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1419 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1420 return (error); 1421 } 1422 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1423#ifdef INET 1424 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1425 mapped = 1; 1426 else 1427#endif 1428 return (EINVAL); 1429 } 1430 1431#ifdef INET 1432 if (mapped == 1) 1433 inp = in_pcblookup(&V_tcbinfo, 1434 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1435 addrs[1].sin6_port, 1436 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1437 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1438 else 1439#endif 1440 inp = in6_pcblookup(&V_tcbinfo, 1441 &addrs[1].sin6_addr, addrs[1].sin6_port, 1442 &addrs[0].sin6_addr, addrs[0].sin6_port, 1443 INPLOOKUP_RLOCKPCB, NULL); 1444 if (inp != NULL) { 1445 if (inp->inp_socket == NULL) 1446 error = ENOENT; 1447 if (error == 0) 1448 error = cr_canseeinpcb(req->td->td_ucred, inp); 1449 if (error == 0) 1450 cru2x(inp->inp_cred, &xuc); 1451 INP_RUNLOCK(inp); 1452 } else 1453 error = ENOENT; 1454 if (error == 0) 1455 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1456 return (error); 1457} 1458 1459SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1460 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1461 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1462#endif /* INET6 */ 1463 1464 1465#ifdef INET 1466void 1467tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1468{ 1469 struct ip *ip = vip; 1470 struct tcphdr *th; 1471 struct in_addr faddr; 1472 struct inpcb *inp; 1473 struct tcpcb *tp; 1474 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1475 struct icmp *icp; 1476 struct in_conninfo inc; 1477 tcp_seq icmp_tcp_seq; 1478 int mtu; 1479 1480 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1481 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1482 return; 1483 1484 if (cmd == PRC_MSGSIZE) 1485 notify = tcp_mtudisc_notify; 1486 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1487 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1488 notify = tcp_drop_syn_sent; 1489 /* 1490 * Redirects don't need to be handled up here. 1491 */ 1492 else if (PRC_IS_REDIRECT(cmd)) 1493 return; 1494 /* 1495 * Source quench is depreciated. 1496 */ 1497 else if (cmd == PRC_QUENCH) 1498 return; 1499 /* 1500 * Hostdead is ugly because it goes linearly through all PCBs. 1501 * XXX: We never get this from ICMP, otherwise it makes an 1502 * excellent DoS attack on machines with many connections. 1503 */ 1504 else if (cmd == PRC_HOSTDEAD) 1505 ip = NULL; 1506 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1507 return; 1508 if (ip != NULL) { 1509 icp = (struct icmp *)((caddr_t)ip 1510 - offsetof(struct icmp, icmp_ip)); 1511 th = (struct tcphdr *)((caddr_t)ip 1512 + (ip->ip_hl << 2)); 1513 INP_INFO_WLOCK(&V_tcbinfo); 1514 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, 1515 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1516 if (inp != NULL) { 1517 if (!(inp->inp_flags & INP_TIMEWAIT) && 1518 !(inp->inp_flags & INP_DROPPED) && 1519 !(inp->inp_socket == NULL)) { 1520 icmp_tcp_seq = htonl(th->th_seq); 1521 tp = intotcpcb(inp); 1522 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1523 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1524 if (cmd == PRC_MSGSIZE) { 1525 /* 1526 * MTU discovery: 1527 * If we got a needfrag set the MTU 1528 * in the route to the suggested new 1529 * value (if given) and then notify. 1530 */ 1531 bzero(&inc, sizeof(inc)); 1532 inc.inc_faddr = faddr; 1533 inc.inc_fibnum = 1534 inp->inp_inc.inc_fibnum; 1535 1536 mtu = ntohs(icp->icmp_nextmtu); 1537 /* 1538 * If no alternative MTU was 1539 * proposed, try the next smaller 1540 * one. 1541 */ 1542 if (!mtu) 1543 mtu = ip_next_mtu( 1544 ntohs(ip->ip_len), 1); 1545 if (mtu < V_tcp_minmss 1546 + sizeof(struct tcpiphdr)) 1547 mtu = V_tcp_minmss 1548 + sizeof(struct tcpiphdr); 1549 /* 1550 * Only cache the MTU if it 1551 * is smaller than the interface 1552 * or route MTU. tcp_mtudisc() 1553 * will do right thing by itself. 1554 */ 1555 if (mtu <= tcp_maxmtu(&inc, NULL)) 1556 tcp_hc_updatemtu(&inc, mtu); 1557 tcp_mtudisc(inp, mtu); 1558 } else 1559 inp = (*notify)(inp, 1560 inetctlerrmap[cmd]); 1561 } 1562 } 1563 if (inp != NULL) 1564 INP_WUNLOCK(inp); 1565 } else { 1566 bzero(&inc, sizeof(inc)); 1567 inc.inc_fport = th->th_dport; 1568 inc.inc_lport = th->th_sport; 1569 inc.inc_faddr = faddr; 1570 inc.inc_laddr = ip->ip_src; 1571 syncache_unreach(&inc, th); 1572 } 1573 INP_INFO_WUNLOCK(&V_tcbinfo); 1574 } else 1575 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1576} 1577#endif /* INET */ 1578 1579#ifdef INET6 1580void 1581tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1582{ 1583 struct tcphdr th; 1584 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1585 struct ip6_hdr *ip6; 1586 struct mbuf *m; 1587 struct ip6ctlparam *ip6cp = NULL; 1588 const struct sockaddr_in6 *sa6_src = NULL; 1589 int off; 1590 struct tcp_portonly { 1591 u_int16_t th_sport; 1592 u_int16_t th_dport; 1593 } *thp; 1594 1595 if (sa->sa_family != AF_INET6 || 1596 sa->sa_len != sizeof(struct sockaddr_in6)) 1597 return; 1598 1599 if (cmd == PRC_MSGSIZE) 1600 notify = tcp_mtudisc_notify; 1601 else if (!PRC_IS_REDIRECT(cmd) && 1602 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1603 return; 1604 /* Source quench is depreciated. */ 1605 else if (cmd == PRC_QUENCH) 1606 return; 1607 1608 /* if the parameter is from icmp6, decode it. */ 1609 if (d != NULL) { 1610 ip6cp = (struct ip6ctlparam *)d; 1611 m = ip6cp->ip6c_m; 1612 ip6 = ip6cp->ip6c_ip6; 1613 off = ip6cp->ip6c_off; 1614 sa6_src = ip6cp->ip6c_src; 1615 } else { 1616 m = NULL; 1617 ip6 = NULL; 1618 off = 0; /* fool gcc */ 1619 sa6_src = &sa6_any; 1620 } 1621 1622 if (ip6 != NULL) { 1623 struct in_conninfo inc; 1624 /* 1625 * XXX: We assume that when IPV6 is non NULL, 1626 * M and OFF are valid. 1627 */ 1628 1629 /* check if we can safely examine src and dst ports */ 1630 if (m->m_pkthdr.len < off + sizeof(*thp)) 1631 return; 1632 1633 bzero(&th, sizeof(th)); 1634 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1635 1636 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1637 (struct sockaddr *)ip6cp->ip6c_src, 1638 th.th_sport, cmd, NULL, notify); 1639 1640 bzero(&inc, sizeof(inc)); 1641 inc.inc_fport = th.th_dport; 1642 inc.inc_lport = th.th_sport; 1643 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1644 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1645 inc.inc_flags |= INC_ISIPV6; 1646 INP_INFO_WLOCK(&V_tcbinfo); 1647 syncache_unreach(&inc, &th); 1648 INP_INFO_WUNLOCK(&V_tcbinfo); 1649 } else 1650 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1651 0, cmd, NULL, notify); 1652} 1653#endif /* INET6 */ 1654 1655 1656/* 1657 * Following is where TCP initial sequence number generation occurs. 1658 * 1659 * There are two places where we must use initial sequence numbers: 1660 * 1. In SYN-ACK packets. 1661 * 2. In SYN packets. 1662 * 1663 * All ISNs for SYN-ACK packets are generated by the syncache. See 1664 * tcp_syncache.c for details. 1665 * 1666 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1667 * depends on this property. In addition, these ISNs should be 1668 * unguessable so as to prevent connection hijacking. To satisfy 1669 * the requirements of this situation, the algorithm outlined in 1670 * RFC 1948 is used, with only small modifications. 1671 * 1672 * Implementation details: 1673 * 1674 * Time is based off the system timer, and is corrected so that it 1675 * increases by one megabyte per second. This allows for proper 1676 * recycling on high speed LANs while still leaving over an hour 1677 * before rollover. 1678 * 1679 * As reading the *exact* system time is too expensive to be done 1680 * whenever setting up a TCP connection, we increment the time 1681 * offset in two ways. First, a small random positive increment 1682 * is added to isn_offset for each connection that is set up. 1683 * Second, the function tcp_isn_tick fires once per clock tick 1684 * and increments isn_offset as necessary so that sequence numbers 1685 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1686 * random positive increments serve only to ensure that the same 1687 * exact sequence number is never sent out twice (as could otherwise 1688 * happen when a port is recycled in less than the system tick 1689 * interval.) 1690 * 1691 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1692 * between seeding of isn_secret. This is normally set to zero, 1693 * as reseeding should not be necessary. 1694 * 1695 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1696 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1697 * general, this means holding an exclusive (write) lock. 1698 */ 1699 1700#define ISN_BYTES_PER_SECOND 1048576 1701#define ISN_STATIC_INCREMENT 4096 1702#define ISN_RANDOM_INCREMENT (4096 - 1) 1703 1704static VNET_DEFINE(u_char, isn_secret[32]); 1705static VNET_DEFINE(int, isn_last); 1706static VNET_DEFINE(int, isn_last_reseed); 1707static VNET_DEFINE(u_int32_t, isn_offset); 1708static VNET_DEFINE(u_int32_t, isn_offset_old); 1709 1710#define V_isn_secret VNET(isn_secret) 1711#define V_isn_last VNET(isn_last) 1712#define V_isn_last_reseed VNET(isn_last_reseed) 1713#define V_isn_offset VNET(isn_offset) 1714#define V_isn_offset_old VNET(isn_offset_old) 1715 1716tcp_seq 1717tcp_new_isn(struct tcpcb *tp) 1718{ 1719 MD5_CTX isn_ctx; 1720 u_int32_t md5_buffer[4]; 1721 tcp_seq new_isn; 1722 u_int32_t projected_offset; 1723 1724 INP_WLOCK_ASSERT(tp->t_inpcb); 1725 1726 ISN_LOCK(); 1727 /* Seed if this is the first use, reseed if requested. */ 1728 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1729 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1730 < (u_int)ticks))) { 1731 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1732 V_isn_last_reseed = ticks; 1733 } 1734 1735 /* Compute the md5 hash and return the ISN. */ 1736 MD5Init(&isn_ctx); 1737 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1738 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1739#ifdef INET6 1740 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1741 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1742 sizeof(struct in6_addr)); 1743 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1744 sizeof(struct in6_addr)); 1745 } else 1746#endif 1747 { 1748 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1749 sizeof(struct in_addr)); 1750 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1751 sizeof(struct in_addr)); 1752 } 1753 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1754 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1755 new_isn = (tcp_seq) md5_buffer[0]; 1756 V_isn_offset += ISN_STATIC_INCREMENT + 1757 (arc4random() & ISN_RANDOM_INCREMENT); 1758 if (ticks != V_isn_last) { 1759 projected_offset = V_isn_offset_old + 1760 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1761 if (SEQ_GT(projected_offset, V_isn_offset)) 1762 V_isn_offset = projected_offset; 1763 V_isn_offset_old = V_isn_offset; 1764 V_isn_last = ticks; 1765 } 1766 new_isn += V_isn_offset; 1767 ISN_UNLOCK(); 1768 return (new_isn); 1769} 1770 1771/* 1772 * When a specific ICMP unreachable message is received and the 1773 * connection state is SYN-SENT, drop the connection. This behavior 1774 * is controlled by the icmp_may_rst sysctl. 1775 */ 1776struct inpcb * 1777tcp_drop_syn_sent(struct inpcb *inp, int errno) 1778{ 1779 struct tcpcb *tp; 1780 1781 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1782 INP_WLOCK_ASSERT(inp); 1783 1784 if ((inp->inp_flags & INP_TIMEWAIT) || 1785 (inp->inp_flags & INP_DROPPED)) 1786 return (inp); 1787 1788 tp = intotcpcb(inp); 1789 if (tp->t_state != TCPS_SYN_SENT) 1790 return (inp); 1791 1792 tp = tcp_drop(tp, errno); 1793 if (tp != NULL) 1794 return (inp); 1795 else 1796 return (NULL); 1797} 1798 1799/* 1800 * When `need fragmentation' ICMP is received, update our idea of the MSS 1801 * based on the new value. Also nudge TCP to send something, since we 1802 * know the packet we just sent was dropped. 1803 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1804 */ 1805static struct inpcb * 1806tcp_mtudisc_notify(struct inpcb *inp, int error) 1807{ 1808 1809 return (tcp_mtudisc(inp, -1)); 1810} 1811 1812struct inpcb * 1813tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1814{ 1815 struct tcpcb *tp; 1816 struct socket *so; 1817 1818 INP_WLOCK_ASSERT(inp); 1819 if ((inp->inp_flags & INP_TIMEWAIT) || 1820 (inp->inp_flags & INP_DROPPED)) 1821 return (inp); 1822 1823 tp = intotcpcb(inp); 1824 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1825 1826 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1827 1828 so = inp->inp_socket; 1829 SOCKBUF_LOCK(&so->so_snd); 1830 /* If the mss is larger than the socket buffer, decrease the mss. */ 1831 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1832 tp->t_maxseg = so->so_snd.sb_hiwat; 1833 SOCKBUF_UNLOCK(&so->so_snd); 1834 1835 TCPSTAT_INC(tcps_mturesent); 1836 tp->t_rtttime = 0; 1837 tp->snd_nxt = tp->snd_una; 1838 tcp_free_sackholes(tp); 1839 tp->snd_recover = tp->snd_max; 1840 if (tp->t_flags & TF_SACK_PERMIT) 1841 EXIT_FASTRECOVERY(tp->t_flags); 1842 tcp_output(tp); 1843 return (inp); 1844} 1845 1846#ifdef INET 1847/* 1848 * Look-up the routing entry to the peer of this inpcb. If no route 1849 * is found and it cannot be allocated, then return 0. This routine 1850 * is called by TCP routines that access the rmx structure and by 1851 * tcp_mss_update to get the peer/interface MTU. 1852 */ 1853u_long 1854tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 1855{ 1856 struct route sro; 1857 struct sockaddr_in *dst; 1858 struct ifnet *ifp; 1859 u_long maxmtu = 0; 1860 1861 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1862 1863 bzero(&sro, sizeof(sro)); 1864 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1865 dst = (struct sockaddr_in *)&sro.ro_dst; 1866 dst->sin_family = AF_INET; 1867 dst->sin_len = sizeof(*dst); 1868 dst->sin_addr = inc->inc_faddr; 1869 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1870 } 1871 if (sro.ro_rt != NULL) { 1872 ifp = sro.ro_rt->rt_ifp; 1873 if (sro.ro_rt->rt_mtu == 0) 1874 maxmtu = ifp->if_mtu; 1875 else 1876 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 1877 1878 /* Report additional interface capabilities. */ 1879 if (cap != NULL) { 1880 if (ifp->if_capenable & IFCAP_TSO4 && 1881 ifp->if_hwassist & CSUM_TSO) { 1882 cap->ifcap |= CSUM_TSO; 1883 cap->tsomax = ifp->if_hw_tsomax; 1884 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1885 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1886 } 1887 } 1888 RTFREE(sro.ro_rt); 1889 } 1890 return (maxmtu); 1891} 1892#endif /* INET */ 1893 1894#ifdef INET6 1895u_long 1896tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 1897{ 1898 struct route_in6 sro6; 1899 struct ifnet *ifp; 1900 u_long maxmtu = 0; 1901 1902 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1903 1904 bzero(&sro6, sizeof(sro6)); 1905 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1906 sro6.ro_dst.sin6_family = AF_INET6; 1907 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1908 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1909 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 1910 } 1911 if (sro6.ro_rt != NULL) { 1912 ifp = sro6.ro_rt->rt_ifp; 1913 if (sro6.ro_rt->rt_mtu == 0) 1914 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1915 else 1916 maxmtu = min(sro6.ro_rt->rt_mtu, 1917 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1918 1919 /* Report additional interface capabilities. */ 1920 if (cap != NULL) { 1921 if (ifp->if_capenable & IFCAP_TSO6 && 1922 ifp->if_hwassist & CSUM_TSO) { 1923 cap->ifcap |= CSUM_TSO; 1924 cap->tsomax = ifp->if_hw_tsomax; 1925 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1926 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1927 } 1928 } 1929 RTFREE(sro6.ro_rt); 1930 } 1931 1932 return (maxmtu); 1933} 1934#endif /* INET6 */ 1935 1936#ifdef IPSEC 1937/* compute ESP/AH header size for TCP, including outer IP header. */ 1938size_t 1939ipsec_hdrsiz_tcp(struct tcpcb *tp) 1940{ 1941 struct inpcb *inp; 1942 struct mbuf *m; 1943 size_t hdrsiz; 1944 struct ip *ip; 1945#ifdef INET6 1946 struct ip6_hdr *ip6; 1947#endif 1948 struct tcphdr *th; 1949 1950 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1951 return (0); 1952 m = m_gethdr(M_NOWAIT, MT_DATA); 1953 if (!m) 1954 return (0); 1955 1956#ifdef INET6 1957 if ((inp->inp_vflag & INP_IPV6) != 0) { 1958 ip6 = mtod(m, struct ip6_hdr *); 1959 th = (struct tcphdr *)(ip6 + 1); 1960 m->m_pkthdr.len = m->m_len = 1961 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1962 tcpip_fillheaders(inp, ip6, th); 1963 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1964 } else 1965#endif /* INET6 */ 1966 { 1967 ip = mtod(m, struct ip *); 1968 th = (struct tcphdr *)(ip + 1); 1969 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1970 tcpip_fillheaders(inp, ip, th); 1971 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1972 } 1973 1974 m_free(m); 1975 return (hdrsiz); 1976} 1977#endif /* IPSEC */ 1978 1979#ifdef TCP_SIGNATURE 1980/* 1981 * Callback function invoked by m_apply() to digest TCP segment data 1982 * contained within an mbuf chain. 1983 */ 1984static int 1985tcp_signature_apply(void *fstate, void *data, u_int len) 1986{ 1987 1988 MD5Update(fstate, (u_char *)data, len); 1989 return (0); 1990} 1991 1992/* 1993 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1994 * 1995 * Parameters: 1996 * m pointer to head of mbuf chain 1997 * _unused 1998 * len length of TCP segment data, excluding options 1999 * optlen length of TCP segment options 2000 * buf pointer to storage for computed MD5 digest 2001 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2002 * 2003 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2004 * When called from tcp_input(), we can be sure that th_sum has been 2005 * zeroed out and verified already. 2006 * 2007 * Return 0 if successful, otherwise return -1. 2008 * 2009 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2010 * search with the destination IP address, and a 'magic SPI' to be 2011 * determined by the application. This is hardcoded elsewhere to 1179 2012 * right now. Another branch of this code exists which uses the SPD to 2013 * specify per-application flows but it is unstable. 2014 */ 2015int 2016tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2017 u_char *buf, u_int direction) 2018{ 2019 union sockaddr_union dst; 2020#ifdef INET 2021 struct ippseudo ippseudo; 2022#endif 2023 MD5_CTX ctx; 2024 int doff; 2025 struct ip *ip; 2026#ifdef INET 2027 struct ipovly *ipovly; 2028#endif 2029 struct secasvar *sav; 2030 struct tcphdr *th; 2031#ifdef INET6 2032 struct ip6_hdr *ip6; 2033 struct in6_addr in6; 2034 char ip6buf[INET6_ADDRSTRLEN]; 2035 uint32_t plen; 2036 uint16_t nhdr; 2037#endif 2038 u_short savecsum; 2039 2040 KASSERT(m != NULL, ("NULL mbuf chain")); 2041 KASSERT(buf != NULL, ("NULL signature pointer")); 2042 2043 /* Extract the destination from the IP header in the mbuf. */ 2044 bzero(&dst, sizeof(union sockaddr_union)); 2045 ip = mtod(m, struct ip *); 2046#ifdef INET6 2047 ip6 = NULL; /* Make the compiler happy. */ 2048#endif 2049 switch (ip->ip_v) { 2050#ifdef INET 2051 case IPVERSION: 2052 dst.sa.sa_len = sizeof(struct sockaddr_in); 2053 dst.sa.sa_family = AF_INET; 2054 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2055 ip->ip_src : ip->ip_dst; 2056 break; 2057#endif 2058#ifdef INET6 2059 case (IPV6_VERSION >> 4): 2060 ip6 = mtod(m, struct ip6_hdr *); 2061 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2062 dst.sa.sa_family = AF_INET6; 2063 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2064 ip6->ip6_src : ip6->ip6_dst; 2065 break; 2066#endif 2067 default: 2068 return (EINVAL); 2069 /* NOTREACHED */ 2070 break; 2071 } 2072 2073 /* Look up an SADB entry which matches the address of the peer. */ 2074 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2075 if (sav == NULL) { 2076 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2077 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2078#ifdef INET6 2079 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2080 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2081#endif 2082 "(unsupported)")); 2083 return (EINVAL); 2084 } 2085 2086 MD5Init(&ctx); 2087 /* 2088 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2089 * 2090 * XXX The ippseudo header MUST be digested in network byte order, 2091 * or else we'll fail the regression test. Assume all fields we've 2092 * been doing arithmetic on have been in host byte order. 2093 * XXX One cannot depend on ipovly->ih_len here. When called from 2094 * tcp_output(), the underlying ip_len member has not yet been set. 2095 */ 2096 switch (ip->ip_v) { 2097#ifdef INET 2098 case IPVERSION: 2099 ipovly = (struct ipovly *)ip; 2100 ippseudo.ippseudo_src = ipovly->ih_src; 2101 ippseudo.ippseudo_dst = ipovly->ih_dst; 2102 ippseudo.ippseudo_pad = 0; 2103 ippseudo.ippseudo_p = IPPROTO_TCP; 2104 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2105 optlen); 2106 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2107 2108 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2109 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2110 break; 2111#endif 2112#ifdef INET6 2113 /* 2114 * RFC 2385, 2.0 Proposal 2115 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2116 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2117 * extended next header value (to form 32 bits), and 32-bit segment 2118 * length. 2119 * Note: Upper-Layer Packet Length comes before Next Header. 2120 */ 2121 case (IPV6_VERSION >> 4): 2122 in6 = ip6->ip6_src; 2123 in6_clearscope(&in6); 2124 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2125 in6 = ip6->ip6_dst; 2126 in6_clearscope(&in6); 2127 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2128 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2129 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2130 nhdr = 0; 2131 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2132 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2133 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2134 nhdr = IPPROTO_TCP; 2135 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2136 2137 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2138 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2139 break; 2140#endif 2141 default: 2142 return (EINVAL); 2143 /* NOTREACHED */ 2144 break; 2145 } 2146 2147 2148 /* 2149 * Step 2: Update MD5 hash with TCP header, excluding options. 2150 * The TCP checksum must be set to zero. 2151 */ 2152 savecsum = th->th_sum; 2153 th->th_sum = 0; 2154 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2155 th->th_sum = savecsum; 2156 2157 /* 2158 * Step 3: Update MD5 hash with TCP segment data. 2159 * Use m_apply() to avoid an early m_pullup(). 2160 */ 2161 if (len > 0) 2162 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2163 2164 /* 2165 * Step 4: Update MD5 hash with shared secret. 2166 */ 2167 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2168 MD5Final(buf, &ctx); 2169 2170 key_sa_recordxfer(sav, m); 2171 KEY_FREESAV(&sav); 2172 return (0); 2173} 2174 2175/* 2176 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2177 * 2178 * Parameters: 2179 * m pointer to head of mbuf chain 2180 * len length of TCP segment data, excluding options 2181 * optlen length of TCP segment options 2182 * buf pointer to storage for computed MD5 digest 2183 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2184 * 2185 * Return 1 if successful, otherwise return 0. 2186 */ 2187int 2188tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2189 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2190{ 2191 char tmpdigest[TCP_SIGLEN]; 2192 2193 if (tcp_sig_checksigs == 0) 2194 return (1); 2195 if ((tcpbflag & TF_SIGNATURE) == 0) { 2196 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2197 2198 /* 2199 * If this socket is not expecting signature but 2200 * the segment contains signature just fail. 2201 */ 2202 TCPSTAT_INC(tcps_sig_err_sigopt); 2203 TCPSTAT_INC(tcps_sig_rcvbadsig); 2204 return (0); 2205 } 2206 2207 /* Signature is not expected, and not present in segment. */ 2208 return (1); 2209 } 2210 2211 /* 2212 * If this socket is expecting signature but the segment does not 2213 * contain any just fail. 2214 */ 2215 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2216 TCPSTAT_INC(tcps_sig_err_nosigopt); 2217 TCPSTAT_INC(tcps_sig_rcvbadsig); 2218 return (0); 2219 } 2220 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2221 IPSEC_DIR_INBOUND) == -1) { 2222 TCPSTAT_INC(tcps_sig_err_buildsig); 2223 TCPSTAT_INC(tcps_sig_rcvbadsig); 2224 return (0); 2225 } 2226 2227 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2228 TCPSTAT_INC(tcps_sig_rcvbadsig); 2229 return (0); 2230 } 2231 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2232 return (1); 2233} 2234#endif /* TCP_SIGNATURE */ 2235 2236static int 2237sysctl_drop(SYSCTL_HANDLER_ARGS) 2238{ 2239 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2240 struct sockaddr_storage addrs[2]; 2241 struct inpcb *inp; 2242 struct tcpcb *tp; 2243 struct tcptw *tw; 2244 struct sockaddr_in *fin, *lin; 2245#ifdef INET6 2246 struct sockaddr_in6 *fin6, *lin6; 2247#endif 2248 int error; 2249 2250 inp = NULL; 2251 fin = lin = NULL; 2252#ifdef INET6 2253 fin6 = lin6 = NULL; 2254#endif 2255 error = 0; 2256 2257 if (req->oldptr != NULL || req->oldlen != 0) 2258 return (EINVAL); 2259 if (req->newptr == NULL) 2260 return (EPERM); 2261 if (req->newlen < sizeof(addrs)) 2262 return (ENOMEM); 2263 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2264 if (error) 2265 return (error); 2266 2267 switch (addrs[0].ss_family) { 2268#ifdef INET6 2269 case AF_INET6: 2270 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2271 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2272 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2273 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2274 return (EINVAL); 2275 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2276 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2277 return (EINVAL); 2278 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2279 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2280 fin = (struct sockaddr_in *)&addrs[0]; 2281 lin = (struct sockaddr_in *)&addrs[1]; 2282 break; 2283 } 2284 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2285 if (error) 2286 return (error); 2287 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2288 if (error) 2289 return (error); 2290 break; 2291#endif 2292#ifdef INET 2293 case AF_INET: 2294 fin = (struct sockaddr_in *)&addrs[0]; 2295 lin = (struct sockaddr_in *)&addrs[1]; 2296 if (fin->sin_len != sizeof(struct sockaddr_in) || 2297 lin->sin_len != sizeof(struct sockaddr_in)) 2298 return (EINVAL); 2299 break; 2300#endif 2301 default: 2302 return (EINVAL); 2303 } 2304 INP_INFO_WLOCK(&V_tcbinfo); 2305 switch (addrs[0].ss_family) { 2306#ifdef INET6 2307 case AF_INET6: 2308 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2309 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2310 INPLOOKUP_WLOCKPCB, NULL); 2311 break; 2312#endif 2313#ifdef INET 2314 case AF_INET: 2315 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2316 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2317 break; 2318#endif 2319 } 2320 if (inp != NULL) { 2321 if (inp->inp_flags & INP_TIMEWAIT) { 2322 /* 2323 * XXXRW: There currently exists a state where an 2324 * inpcb is present, but its timewait state has been 2325 * discarded. For now, don't allow dropping of this 2326 * type of inpcb. 2327 */ 2328 tw = intotw(inp); 2329 if (tw != NULL) 2330 tcp_twclose(tw, 0); 2331 else 2332 INP_WUNLOCK(inp); 2333 } else if (!(inp->inp_flags & INP_DROPPED) && 2334 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2335 tp = intotcpcb(inp); 2336 tp = tcp_drop(tp, ECONNABORTED); 2337 if (tp != NULL) 2338 INP_WUNLOCK(inp); 2339 } else 2340 INP_WUNLOCK(inp); 2341 } else 2342 error = ESRCH; 2343 INP_INFO_WUNLOCK(&V_tcbinfo); 2344 return (error); 2345} 2346 2347SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2348 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2349 0, sysctl_drop, "", "Drop TCP connection"); 2350 2351/* 2352 * Generate a standardized TCP log line for use throughout the 2353 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2354 * allow use in the interrupt context. 2355 * 2356 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2357 * NB: The function may return NULL if memory allocation failed. 2358 * 2359 * Due to header inclusion and ordering limitations the struct ip 2360 * and ip6_hdr pointers have to be passed as void pointers. 2361 */ 2362char * 2363tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2364 const void *ip6hdr) 2365{ 2366 2367 /* Is logging enabled? */ 2368 if (tcp_log_in_vain == 0) 2369 return (NULL); 2370 2371 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2372} 2373 2374char * 2375tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2376 const void *ip6hdr) 2377{ 2378 2379 /* Is logging enabled? */ 2380 if (tcp_log_debug == 0) 2381 return (NULL); 2382 2383 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2384} 2385 2386static char * 2387tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2388 const void *ip6hdr) 2389{ 2390 char *s, *sp; 2391 size_t size; 2392 struct ip *ip; 2393#ifdef INET6 2394 const struct ip6_hdr *ip6; 2395 2396 ip6 = (const struct ip6_hdr *)ip6hdr; 2397#endif /* INET6 */ 2398 ip = (struct ip *)ip4hdr; 2399 2400 /* 2401 * The log line looks like this: 2402 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2403 */ 2404 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2405 sizeof(PRINT_TH_FLAGS) + 1 + 2406#ifdef INET6 2407 2 * INET6_ADDRSTRLEN; 2408#else 2409 2 * INET_ADDRSTRLEN; 2410#endif /* INET6 */ 2411 2412 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2413 if (s == NULL) 2414 return (NULL); 2415 2416 strcat(s, "TCP: ["); 2417 sp = s + strlen(s); 2418 2419 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2420 inet_ntoa_r(inc->inc_faddr, sp); 2421 sp = s + strlen(s); 2422 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2423 sp = s + strlen(s); 2424 inet_ntoa_r(inc->inc_laddr, sp); 2425 sp = s + strlen(s); 2426 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2427#ifdef INET6 2428 } else if (inc) { 2429 ip6_sprintf(sp, &inc->inc6_faddr); 2430 sp = s + strlen(s); 2431 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2432 sp = s + strlen(s); 2433 ip6_sprintf(sp, &inc->inc6_laddr); 2434 sp = s + strlen(s); 2435 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2436 } else if (ip6 && th) { 2437 ip6_sprintf(sp, &ip6->ip6_src); 2438 sp = s + strlen(s); 2439 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2440 sp = s + strlen(s); 2441 ip6_sprintf(sp, &ip6->ip6_dst); 2442 sp = s + strlen(s); 2443 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2444#endif /* INET6 */ 2445#ifdef INET 2446 } else if (ip && th) { 2447 inet_ntoa_r(ip->ip_src, sp); 2448 sp = s + strlen(s); 2449 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2450 sp = s + strlen(s); 2451 inet_ntoa_r(ip->ip_dst, sp); 2452 sp = s + strlen(s); 2453 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2454#endif /* INET */ 2455 } else { 2456 free(s, M_TCPLOG); 2457 return (NULL); 2458 } 2459 sp = s + strlen(s); 2460 if (th) 2461 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2462 if (*(s + size - 1) != '\0') 2463 panic("%s: string too long", __func__); 2464 return (s); 2465} 2466 2467/* 2468 * A subroutine which makes it easy to track TCP state changes with DTrace. 2469 * This function shouldn't be called for t_state initializations that don't 2470 * correspond to actual TCP state transitions. 2471 */ 2472void 2473tcp_state_change(struct tcpcb *tp, int newstate) 2474{ 2475#if defined(KDTRACE_HOOKS) 2476 int pstate = tp->t_state; 2477#endif 2478 2479 tp->t_state = newstate; 2480 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2481} 2482