tcp_subr.c revision 285979
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: releng/10.1/sys/netinet/tcp_subr.c 285979 2015-07-28 19:59:11Z 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); 233 234/* 235 * Target size of TCP PCB hash tables. Must be a power of two. 236 * 237 * Note that this can be overridden by the kernel environment 238 * variable net.inet.tcp.tcbhashsize 239 */ 240#ifndef TCBHASHSIZE 241#define TCBHASHSIZE 0 242#endif 243 244/* 245 * XXX 246 * Callouts should be moved into struct tcp directly. They are currently 247 * separate because the tcpcb structure is exported to userland for sysctl 248 * parsing purposes, which do not know about callouts. 249 */ 250struct tcpcb_mem { 251 struct tcpcb tcb; 252 struct tcp_timer tt; 253 struct cc_var ccv; 254 struct osd osd; 255}; 256 257static VNET_DEFINE(uma_zone_t, tcpcb_zone); 258#define V_tcpcb_zone VNET(tcpcb_zone) 259 260MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 261static struct mtx isn_mtx; 262 263#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 264#define ISN_LOCK() mtx_lock(&isn_mtx) 265#define ISN_UNLOCK() mtx_unlock(&isn_mtx) 266 267/* 268 * TCP initialization. 269 */ 270static void 271tcp_zone_change(void *tag) 272{ 273 274 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 275 uma_zone_set_max(V_tcpcb_zone, maxsockets); 276 tcp_tw_zone_change(); 277} 278 279static int 280tcp_inpcb_init(void *mem, int size, int flags) 281{ 282 struct inpcb *inp = mem; 283 284 INP_LOCK_INIT(inp, "inp", "tcpinp"); 285 return (0); 286} 287 288/* 289 * Take a value and get the next power of 2 that doesn't overflow. 290 * Used to size the tcp_inpcb hash buckets. 291 */ 292static int 293maketcp_hashsize(int size) 294{ 295 int hashsize; 296 297 /* 298 * auto tune. 299 * get the next power of 2 higher than maxsockets. 300 */ 301 hashsize = 1 << fls(size); 302 /* catch overflow, and just go one power of 2 smaller */ 303 if (hashsize < size) { 304 hashsize = 1 << (fls(size) - 1); 305 } 306 return (hashsize); 307} 308 309void 310tcp_init(void) 311{ 312 const char *tcbhash_tuneable; 313 int hashsize; 314 315 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 316 317 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 318 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 319 printf("%s: WARNING: unable to register helper hook\n", __func__); 320 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 321 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 322 printf("%s: WARNING: unable to register helper hook\n", __func__); 323 324 hashsize = TCBHASHSIZE; 325 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 326 if (hashsize == 0) { 327 /* 328 * Auto tune the hash size based on maxsockets. 329 * A perfect hash would have a 1:1 mapping 330 * (hashsize = maxsockets) however it's been 331 * suggested that O(2) average is better. 332 */ 333 hashsize = maketcp_hashsize(maxsockets / 4); 334 /* 335 * Our historical default is 512, 336 * do not autotune lower than this. 337 */ 338 if (hashsize < 512) 339 hashsize = 512; 340 if (bootverbose) 341 printf("%s: %s auto tuned to %d\n", __func__, 342 tcbhash_tuneable, hashsize); 343 } 344 /* 345 * We require a hashsize to be a power of two. 346 * Previously if it was not a power of two we would just reset it 347 * back to 512, which could be a nasty surprise if you did not notice 348 * the error message. 349 * Instead what we do is clip it to the closest power of two lower 350 * than the specified hash value. 351 */ 352 if (!powerof2(hashsize)) { 353 int oldhashsize = hashsize; 354 355 hashsize = maketcp_hashsize(hashsize); 356 /* prevent absurdly low value */ 357 if (hashsize < 16) 358 hashsize = 16; 359 printf("%s: WARNING: TCB hash size not a power of 2, " 360 "clipped from %d to %d.\n", __func__, oldhashsize, 361 hashsize); 362 } 363 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 364 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 365 IPI_HASHFIELDS_4TUPLE); 366 367 /* 368 * These have to be type stable for the benefit of the timers. 369 */ 370 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 371 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 372 uma_zone_set_max(V_tcpcb_zone, maxsockets); 373 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 374 375 tcp_tw_init(); 376 syncache_init(); 377 tcp_hc_init(); 378 379 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 380 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 381 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 382 383 /* Skip initialization of globals for non-default instances. */ 384 if (!IS_DEFAULT_VNET(curvnet)) 385 return; 386 387 tcp_reass_global_init(); 388 389 /* XXX virtualize those bellow? */ 390 tcp_delacktime = TCPTV_DELACK; 391 tcp_keepinit = TCPTV_KEEP_INIT; 392 tcp_keepidle = TCPTV_KEEP_IDLE; 393 tcp_keepintvl = TCPTV_KEEPINTVL; 394 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 395 tcp_msl = TCPTV_MSL; 396 tcp_rexmit_min = TCPTV_MIN; 397 if (tcp_rexmit_min < 1) 398 tcp_rexmit_min = 1; 399 tcp_rexmit_slop = TCPTV_CPU_VAR; 400 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 401 tcp_tcbhashsize = hashsize; 402 403 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 404 if (tcp_soreceive_stream) { 405#ifdef INET 406 tcp_usrreqs.pru_soreceive = soreceive_stream; 407#endif 408#ifdef INET6 409 tcp6_usrreqs.pru_soreceive = soreceive_stream; 410#endif /* INET6 */ 411 } 412 413#ifdef INET6 414#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 415#else /* INET6 */ 416#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 417#endif /* INET6 */ 418 if (max_protohdr < TCP_MINPROTOHDR) 419 max_protohdr = TCP_MINPROTOHDR; 420 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 421 panic("tcp_init"); 422#undef TCP_MINPROTOHDR 423 424 ISN_LOCK_INIT(); 425 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 426 SHUTDOWN_PRI_DEFAULT); 427 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 428 EVENTHANDLER_PRI_ANY); 429} 430 431#ifdef VIMAGE 432void 433tcp_destroy(void) 434{ 435 436 tcp_hc_destroy(); 437 syncache_destroy(); 438 tcp_tw_destroy(); 439 in_pcbinfo_destroy(&V_tcbinfo); 440 uma_zdestroy(V_sack_hole_zone); 441 uma_zdestroy(V_tcpcb_zone); 442} 443#endif 444 445void 446tcp_fini(void *xtp) 447{ 448 449} 450 451/* 452 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 453 * tcp_template used to store this data in mbufs, but we now recopy it out 454 * of the tcpcb each time to conserve mbufs. 455 */ 456void 457tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 458{ 459 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 460 461 INP_WLOCK_ASSERT(inp); 462 463#ifdef INET6 464 if ((inp->inp_vflag & INP_IPV6) != 0) { 465 struct ip6_hdr *ip6; 466 467 ip6 = (struct ip6_hdr *)ip_ptr; 468 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 469 (inp->inp_flow & IPV6_FLOWINFO_MASK); 470 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 471 (IPV6_VERSION & IPV6_VERSION_MASK); 472 ip6->ip6_nxt = IPPROTO_TCP; 473 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 474 ip6->ip6_src = inp->in6p_laddr; 475 ip6->ip6_dst = inp->in6p_faddr; 476 } 477#endif /* INET6 */ 478#if defined(INET6) && defined(INET) 479 else 480#endif 481#ifdef INET 482 { 483 struct ip *ip; 484 485 ip = (struct ip *)ip_ptr; 486 ip->ip_v = IPVERSION; 487 ip->ip_hl = 5; 488 ip->ip_tos = inp->inp_ip_tos; 489 ip->ip_len = 0; 490 ip->ip_id = 0; 491 ip->ip_off = 0; 492 ip->ip_ttl = inp->inp_ip_ttl; 493 ip->ip_sum = 0; 494 ip->ip_p = IPPROTO_TCP; 495 ip->ip_src = inp->inp_laddr; 496 ip->ip_dst = inp->inp_faddr; 497 } 498#endif /* INET */ 499 th->th_sport = inp->inp_lport; 500 th->th_dport = inp->inp_fport; 501 th->th_seq = 0; 502 th->th_ack = 0; 503 th->th_x2 = 0; 504 th->th_off = 5; 505 th->th_flags = 0; 506 th->th_win = 0; 507 th->th_urp = 0; 508 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 509} 510 511/* 512 * Create template to be used to send tcp packets on a connection. 513 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 514 * use for this function is in keepalives, which use tcp_respond. 515 */ 516struct tcptemp * 517tcpip_maketemplate(struct inpcb *inp) 518{ 519 struct tcptemp *t; 520 521 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 522 if (t == NULL) 523 return (NULL); 524 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 525 return (t); 526} 527 528/* 529 * Send a single message to the TCP at address specified by 530 * the given TCP/IP header. If m == NULL, then we make a copy 531 * of the tcpiphdr at ti and send directly to the addressed host. 532 * This is used to force keep alive messages out using the TCP 533 * template for a connection. If flags are given then we send 534 * a message back to the TCP which originated the * segment ti, 535 * and discard the mbuf containing it and any other attached mbufs. 536 * 537 * In any case the ack and sequence number of the transmitted 538 * segment are as specified by the parameters. 539 * 540 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 541 */ 542void 543tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 544 tcp_seq ack, tcp_seq seq, int flags) 545{ 546 int tlen; 547 int win = 0; 548 struct ip *ip; 549 struct tcphdr *nth; 550#ifdef INET6 551 struct ip6_hdr *ip6; 552 int isipv6; 553#endif /* INET6 */ 554 int ipflags = 0; 555 struct inpcb *inp; 556 557 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 558 559#ifdef INET6 560 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 561 ip6 = ipgen; 562#endif /* INET6 */ 563 ip = ipgen; 564 565 if (tp != NULL) { 566 inp = tp->t_inpcb; 567 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 568 INP_WLOCK_ASSERT(inp); 569 } else 570 inp = NULL; 571 572 if (tp != NULL) { 573 if (!(flags & TH_RST)) { 574 win = sbspace(&inp->inp_socket->so_rcv); 575 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 576 win = (long)TCP_MAXWIN << tp->rcv_scale; 577 } 578 } 579 if (m == NULL) { 580 m = m_gethdr(M_NOWAIT, MT_DATA); 581 if (m == NULL) 582 return; 583 tlen = 0; 584 m->m_data += max_linkhdr; 585#ifdef INET6 586 if (isipv6) { 587 bcopy((caddr_t)ip6, mtod(m, caddr_t), 588 sizeof(struct ip6_hdr)); 589 ip6 = mtod(m, struct ip6_hdr *); 590 nth = (struct tcphdr *)(ip6 + 1); 591 } else 592#endif /* INET6 */ 593 { 594 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 595 ip = mtod(m, struct ip *); 596 nth = (struct tcphdr *)(ip + 1); 597 } 598 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 599 flags = TH_ACK; 600 } else { 601 /* 602 * reuse the mbuf. 603 * XXX MRT We inherrit the FIB, which is lucky. 604 */ 605 m_freem(m->m_next); 606 m->m_next = NULL; 607 m->m_data = (caddr_t)ipgen; 608 /* m_len is set later */ 609 tlen = 0; 610#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 611#ifdef INET6 612 if (isipv6) { 613 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 614 nth = (struct tcphdr *)(ip6 + 1); 615 } else 616#endif /* INET6 */ 617 { 618 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 619 nth = (struct tcphdr *)(ip + 1); 620 } 621 if (th != nth) { 622 /* 623 * this is usually a case when an extension header 624 * exists between the IPv6 header and the 625 * TCP header. 626 */ 627 nth->th_sport = th->th_sport; 628 nth->th_dport = th->th_dport; 629 } 630 xchg(nth->th_dport, nth->th_sport, uint16_t); 631#undef xchg 632 } 633#ifdef INET6 634 if (isipv6) { 635 ip6->ip6_flow = 0; 636 ip6->ip6_vfc = IPV6_VERSION; 637 ip6->ip6_nxt = IPPROTO_TCP; 638 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 639 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 640 } 641#endif 642#if defined(INET) && defined(INET6) 643 else 644#endif 645#ifdef INET 646 { 647 tlen += sizeof (struct tcpiphdr); 648 ip->ip_len = htons(tlen); 649 ip->ip_ttl = V_ip_defttl; 650 if (V_path_mtu_discovery) 651 ip->ip_off |= htons(IP_DF); 652 } 653#endif 654 m->m_len = tlen; 655 m->m_pkthdr.len = tlen; 656 m->m_pkthdr.rcvif = NULL; 657#ifdef MAC 658 if (inp != NULL) { 659 /* 660 * Packet is associated with a socket, so allow the 661 * label of the response to reflect the socket label. 662 */ 663 INP_WLOCK_ASSERT(inp); 664 mac_inpcb_create_mbuf(inp, m); 665 } else { 666 /* 667 * Packet is not associated with a socket, so possibly 668 * update the label in place. 669 */ 670 mac_netinet_tcp_reply(m); 671 } 672#endif 673 nth->th_seq = htonl(seq); 674 nth->th_ack = htonl(ack); 675 nth->th_x2 = 0; 676 nth->th_off = sizeof (struct tcphdr) >> 2; 677 nth->th_flags = flags; 678 if (tp != NULL) 679 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 680 else 681 nth->th_win = htons((u_short)win); 682 nth->th_urp = 0; 683 684 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 685#ifdef INET6 686 if (isipv6) { 687 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 688 nth->th_sum = in6_cksum_pseudo(ip6, 689 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 690 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 691 NULL, NULL); 692 } 693#endif /* INET6 */ 694#if defined(INET6) && defined(INET) 695 else 696#endif 697#ifdef INET 698 { 699 m->m_pkthdr.csum_flags = CSUM_TCP; 700 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 701 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 702 } 703#endif /* INET */ 704#ifdef TCPDEBUG 705 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 706 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 707#endif 708 if (flags & TH_RST) 709 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 710 tp, nth); 711 712 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 713#ifdef INET6 714 if (isipv6) 715 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 716#endif /* INET6 */ 717#if defined(INET) && defined(INET6) 718 else 719#endif 720#ifdef INET 721 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 722#endif 723} 724 725/* 726 * Create a new TCP control block, making an 727 * empty reassembly queue and hooking it to the argument 728 * protocol control block. The `inp' parameter must have 729 * come from the zone allocator set up in tcp_init(). 730 */ 731struct tcpcb * 732tcp_newtcpcb(struct inpcb *inp) 733{ 734 struct tcpcb_mem *tm; 735 struct tcpcb *tp; 736#ifdef INET6 737 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 738#endif /* INET6 */ 739 740 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 741 if (tm == NULL) 742 return (NULL); 743 tp = &tm->tcb; 744 745 /* Initialise cc_var struct for this tcpcb. */ 746 tp->ccv = &tm->ccv; 747 tp->ccv->type = IPPROTO_TCP; 748 tp->ccv->ccvc.tcp = tp; 749 750 /* 751 * Use the current system default CC algorithm. 752 */ 753 CC_LIST_RLOCK(); 754 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 755 CC_ALGO(tp) = CC_DEFAULT(); 756 CC_LIST_RUNLOCK(); 757 758 if (CC_ALGO(tp)->cb_init != NULL) 759 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 760 uma_zfree(V_tcpcb_zone, tm); 761 return (NULL); 762 } 763 764 tp->osd = &tm->osd; 765 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 766 uma_zfree(V_tcpcb_zone, tm); 767 return (NULL); 768 } 769 770#ifdef VIMAGE 771 tp->t_vnet = inp->inp_vnet; 772#endif 773 tp->t_timers = &tm->tt; 774 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 775 tp->t_maxseg = tp->t_maxopd = 776#ifdef INET6 777 isipv6 ? V_tcp_v6mssdflt : 778#endif /* INET6 */ 779 V_tcp_mssdflt; 780 781 /* Set up our timeouts. */ 782 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 783 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 784 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 785 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 786 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 787 788 if (V_tcp_do_rfc1323) 789 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 790 if (V_tcp_do_sack) 791 tp->t_flags |= TF_SACK_PERMIT; 792 TAILQ_INIT(&tp->snd_holes); 793 tp->t_inpcb = inp; /* XXX */ 794 /* 795 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 796 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 797 * reasonable initial retransmit time. 798 */ 799 tp->t_srtt = TCPTV_SRTTBASE; 800 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 801 tp->t_rttmin = tcp_rexmit_min; 802 tp->t_rxtcur = TCPTV_RTOBASE; 803 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 804 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 805 tp->t_rcvtime = ticks; 806 /* 807 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 808 * because the socket may be bound to an IPv6 wildcard address, 809 * which may match an IPv4-mapped IPv6 address. 810 */ 811 inp->inp_ip_ttl = V_ip_defttl; 812 inp->inp_ppcb = tp; 813 return (tp); /* XXX */ 814} 815 816/* 817 * Switch the congestion control algorithm back to NewReno for any active 818 * control blocks using an algorithm which is about to go away. 819 * This ensures the CC framework can allow the unload to proceed without leaving 820 * any dangling pointers which would trigger a panic. 821 * Returning non-zero would inform the CC framework that something went wrong 822 * and it would be unsafe to allow the unload to proceed. However, there is no 823 * way for this to occur with this implementation so we always return zero. 824 */ 825int 826tcp_ccalgounload(struct cc_algo *unload_algo) 827{ 828 struct cc_algo *tmpalgo; 829 struct inpcb *inp; 830 struct tcpcb *tp; 831 VNET_ITERATOR_DECL(vnet_iter); 832 833 /* 834 * Check all active control blocks across all network stacks and change 835 * any that are using "unload_algo" back to NewReno. If "unload_algo" 836 * requires cleanup code to be run, call it. 837 */ 838 VNET_LIST_RLOCK(); 839 VNET_FOREACH(vnet_iter) { 840 CURVNET_SET(vnet_iter); 841 INP_INFO_RLOCK(&V_tcbinfo); 842 /* 843 * New connections already part way through being initialised 844 * with the CC algo we're removing will not race with this code 845 * because the INP_INFO_WLOCK is held during initialisation. We 846 * therefore don't enter the loop below until the connection 847 * list has stabilised. 848 */ 849 LIST_FOREACH(inp, &V_tcb, inp_list) { 850 INP_WLOCK(inp); 851 /* Important to skip tcptw structs. */ 852 if (!(inp->inp_flags & INP_TIMEWAIT) && 853 (tp = intotcpcb(inp)) != NULL) { 854 /* 855 * By holding INP_WLOCK here, we are assured 856 * that the connection is not currently 857 * executing inside the CC module's functions 858 * i.e. it is safe to make the switch back to 859 * NewReno. 860 */ 861 if (CC_ALGO(tp) == unload_algo) { 862 tmpalgo = CC_ALGO(tp); 863 /* NewReno does not require any init. */ 864 CC_ALGO(tp) = &newreno_cc_algo; 865 if (tmpalgo->cb_destroy != NULL) 866 tmpalgo->cb_destroy(tp->ccv); 867 } 868 } 869 INP_WUNLOCK(inp); 870 } 871 INP_INFO_RUNLOCK(&V_tcbinfo); 872 CURVNET_RESTORE(); 873 } 874 VNET_LIST_RUNLOCK(); 875 876 return (0); 877} 878 879/* 880 * Drop a TCP connection, reporting 881 * the specified error. If connection is synchronized, 882 * then send a RST to peer. 883 */ 884struct tcpcb * 885tcp_drop(struct tcpcb *tp, int errno) 886{ 887 struct socket *so = tp->t_inpcb->inp_socket; 888 889 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 890 INP_WLOCK_ASSERT(tp->t_inpcb); 891 892 if (TCPS_HAVERCVDSYN(tp->t_state)) { 893 tcp_state_change(tp, TCPS_CLOSED); 894 (void) tcp_output(tp); 895 TCPSTAT_INC(tcps_drops); 896 } else 897 TCPSTAT_INC(tcps_conndrops); 898 if (errno == ETIMEDOUT && tp->t_softerror) 899 errno = tp->t_softerror; 900 so->so_error = errno; 901 return (tcp_close(tp)); 902} 903 904void 905tcp_discardcb(struct tcpcb *tp) 906{ 907 struct inpcb *inp = tp->t_inpcb; 908 struct socket *so = inp->inp_socket; 909#ifdef INET6 910 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 911#endif /* INET6 */ 912 913 INP_WLOCK_ASSERT(inp); 914 915 /* 916 * Make sure that all of our timers are stopped before we delete the 917 * PCB. 918 * 919 * XXXRW: Really, we would like to use callout_drain() here in order 920 * to avoid races experienced in tcp_timer.c where a timer is already 921 * executing at this point. However, we can't, both because we're 922 * running in a context where we can't sleep, and also because we 923 * hold locks required by the timers. What we instead need to do is 924 * test to see if callout_drain() is required, and if so, defer some 925 * portion of the remainder of tcp_discardcb() to an asynchronous 926 * context that can callout_drain() and then continue. Some care 927 * will be required to ensure that no further processing takes place 928 * on the tcpcb, even though it hasn't been freed (a flag?). 929 */ 930 callout_stop(&tp->t_timers->tt_rexmt); 931 callout_stop(&tp->t_timers->tt_persist); 932 callout_stop(&tp->t_timers->tt_keep); 933 callout_stop(&tp->t_timers->tt_2msl); 934 callout_stop(&tp->t_timers->tt_delack); 935 936 /* 937 * If we got enough samples through the srtt filter, 938 * save the rtt and rttvar in the routing entry. 939 * 'Enough' is arbitrarily defined as 4 rtt samples. 940 * 4 samples is enough for the srtt filter to converge 941 * to within enough % of the correct value; fewer samples 942 * and we could save a bogus rtt. The danger is not high 943 * as tcp quickly recovers from everything. 944 * XXX: Works very well but needs some more statistics! 945 */ 946 if (tp->t_rttupdated >= 4) { 947 struct hc_metrics_lite metrics; 948 u_long ssthresh; 949 950 bzero(&metrics, sizeof(metrics)); 951 /* 952 * Update the ssthresh always when the conditions below 953 * are satisfied. This gives us better new start value 954 * for the congestion avoidance for new connections. 955 * ssthresh is only set if packet loss occured on a session. 956 * 957 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 958 * being torn down. Ideally this code would not use 'so'. 959 */ 960 ssthresh = tp->snd_ssthresh; 961 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 962 /* 963 * convert the limit from user data bytes to 964 * packets then to packet data bytes. 965 */ 966 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 967 if (ssthresh < 2) 968 ssthresh = 2; 969 ssthresh *= (u_long)(tp->t_maxseg + 970#ifdef INET6 971 (isipv6 ? sizeof (struct ip6_hdr) + 972 sizeof (struct tcphdr) : 973#endif 974 sizeof (struct tcpiphdr) 975#ifdef INET6 976 ) 977#endif 978 ); 979 } else 980 ssthresh = 0; 981 metrics.rmx_ssthresh = ssthresh; 982 983 metrics.rmx_rtt = tp->t_srtt; 984 metrics.rmx_rttvar = tp->t_rttvar; 985 metrics.rmx_cwnd = tp->snd_cwnd; 986 metrics.rmx_sendpipe = 0; 987 metrics.rmx_recvpipe = 0; 988 989 tcp_hc_update(&inp->inp_inc, &metrics); 990 } 991 992 /* free the reassembly queue, if any */ 993 tcp_reass_flush(tp); 994 995#ifdef TCP_OFFLOAD 996 /* Disconnect offload device, if any. */ 997 if (tp->t_flags & TF_TOE) 998 tcp_offload_detach(tp); 999#endif 1000 1001 tcp_free_sackholes(tp); 1002 1003 /* Allow the CC algorithm to clean up after itself. */ 1004 if (CC_ALGO(tp)->cb_destroy != NULL) 1005 CC_ALGO(tp)->cb_destroy(tp->ccv); 1006 1007 khelp_destroy_osd(tp->osd); 1008 1009 CC_ALGO(tp) = NULL; 1010 inp->inp_ppcb = NULL; 1011 tp->t_inpcb = NULL; 1012 uma_zfree(V_tcpcb_zone, tp); 1013} 1014 1015/* 1016 * Attempt to close a TCP control block, marking it as dropped, and freeing 1017 * the socket if we hold the only reference. 1018 */ 1019struct tcpcb * 1020tcp_close(struct tcpcb *tp) 1021{ 1022 struct inpcb *inp = tp->t_inpcb; 1023 struct socket *so; 1024 1025 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1026 INP_WLOCK_ASSERT(inp); 1027 1028#ifdef TCP_OFFLOAD 1029 if (tp->t_state == TCPS_LISTEN) 1030 tcp_offload_listen_stop(tp); 1031#endif 1032 in_pcbdrop(inp); 1033 TCPSTAT_INC(tcps_closed); 1034 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1035 so = inp->inp_socket; 1036 soisdisconnected(so); 1037 if (inp->inp_flags & INP_SOCKREF) { 1038 KASSERT(so->so_state & SS_PROTOREF, 1039 ("tcp_close: !SS_PROTOREF")); 1040 inp->inp_flags &= ~INP_SOCKREF; 1041 INP_WUNLOCK(inp); 1042 ACCEPT_LOCK(); 1043 SOCK_LOCK(so); 1044 so->so_state &= ~SS_PROTOREF; 1045 sofree(so); 1046 return (NULL); 1047 } 1048 return (tp); 1049} 1050 1051void 1052tcp_drain(void) 1053{ 1054 VNET_ITERATOR_DECL(vnet_iter); 1055 1056 if (!do_tcpdrain) 1057 return; 1058 1059 VNET_LIST_RLOCK_NOSLEEP(); 1060 VNET_FOREACH(vnet_iter) { 1061 CURVNET_SET(vnet_iter); 1062 struct inpcb *inpb; 1063 struct tcpcb *tcpb; 1064 1065 /* 1066 * Walk the tcpbs, if existing, and flush the reassembly queue, 1067 * if there is one... 1068 * XXX: The "Net/3" implementation doesn't imply that the TCP 1069 * reassembly queue should be flushed, but in a situation 1070 * where we're really low on mbufs, this is potentially 1071 * useful. 1072 */ 1073 INP_INFO_RLOCK(&V_tcbinfo); 1074 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1075 if (inpb->inp_flags & INP_TIMEWAIT) 1076 continue; 1077 INP_WLOCK(inpb); 1078 if ((tcpb = intotcpcb(inpb)) != NULL) { 1079 tcp_reass_flush(tcpb); 1080 tcp_clean_sackreport(tcpb); 1081 } 1082 INP_WUNLOCK(inpb); 1083 } 1084 INP_INFO_RUNLOCK(&V_tcbinfo); 1085 CURVNET_RESTORE(); 1086 } 1087 VNET_LIST_RUNLOCK_NOSLEEP(); 1088} 1089 1090/* 1091 * Notify a tcp user of an asynchronous error; 1092 * store error as soft error, but wake up user 1093 * (for now, won't do anything until can select for soft error). 1094 * 1095 * Do not wake up user since there currently is no mechanism for 1096 * reporting soft errors (yet - a kqueue filter may be added). 1097 */ 1098static struct inpcb * 1099tcp_notify(struct inpcb *inp, int error) 1100{ 1101 struct tcpcb *tp; 1102 1103 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1104 INP_WLOCK_ASSERT(inp); 1105 1106 if ((inp->inp_flags & INP_TIMEWAIT) || 1107 (inp->inp_flags & INP_DROPPED)) 1108 return (inp); 1109 1110 tp = intotcpcb(inp); 1111 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1112 1113 /* 1114 * Ignore some errors if we are hooked up. 1115 * If connection hasn't completed, has retransmitted several times, 1116 * and receives a second error, give up now. This is better 1117 * than waiting a long time to establish a connection that 1118 * can never complete. 1119 */ 1120 if (tp->t_state == TCPS_ESTABLISHED && 1121 (error == EHOSTUNREACH || error == ENETUNREACH || 1122 error == EHOSTDOWN)) { 1123 return (inp); 1124 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1125 tp->t_softerror) { 1126 tp = tcp_drop(tp, error); 1127 if (tp != NULL) 1128 return (inp); 1129 else 1130 return (NULL); 1131 } else { 1132 tp->t_softerror = error; 1133 return (inp); 1134 } 1135#if 0 1136 wakeup( &so->so_timeo); 1137 sorwakeup(so); 1138 sowwakeup(so); 1139#endif 1140} 1141 1142static int 1143tcp_pcblist(SYSCTL_HANDLER_ARGS) 1144{ 1145 int error, i, m, n, pcb_count; 1146 struct inpcb *inp, **inp_list; 1147 inp_gen_t gencnt; 1148 struct xinpgen xig; 1149 1150 /* 1151 * The process of preparing the TCB list is too time-consuming and 1152 * resource-intensive to repeat twice on every request. 1153 */ 1154 if (req->oldptr == NULL) { 1155 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1156 n += imax(n / 8, 10); 1157 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1158 return (0); 1159 } 1160 1161 if (req->newptr != NULL) 1162 return (EPERM); 1163 1164 /* 1165 * OK, now we're committed to doing something. 1166 */ 1167 INP_INFO_RLOCK(&V_tcbinfo); 1168 gencnt = V_tcbinfo.ipi_gencnt; 1169 n = V_tcbinfo.ipi_count; 1170 INP_INFO_RUNLOCK(&V_tcbinfo); 1171 1172 m = syncache_pcbcount(); 1173 1174 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1175 + (n + m) * sizeof(struct xtcpcb)); 1176 if (error != 0) 1177 return (error); 1178 1179 xig.xig_len = sizeof xig; 1180 xig.xig_count = n + m; 1181 xig.xig_gen = gencnt; 1182 xig.xig_sogen = so_gencnt; 1183 error = SYSCTL_OUT(req, &xig, sizeof xig); 1184 if (error) 1185 return (error); 1186 1187 error = syncache_pcblist(req, m, &pcb_count); 1188 if (error) 1189 return (error); 1190 1191 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1192 if (inp_list == NULL) 1193 return (ENOMEM); 1194 1195 INP_INFO_RLOCK(&V_tcbinfo); 1196 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1197 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1198 INP_WLOCK(inp); 1199 if (inp->inp_gencnt <= gencnt) { 1200 /* 1201 * XXX: This use of cr_cansee(), introduced with 1202 * TCP state changes, is not quite right, but for 1203 * now, better than nothing. 1204 */ 1205 if (inp->inp_flags & INP_TIMEWAIT) { 1206 if (intotw(inp) != NULL) 1207 error = cr_cansee(req->td->td_ucred, 1208 intotw(inp)->tw_cred); 1209 else 1210 error = EINVAL; /* Skip this inp. */ 1211 } else 1212 error = cr_canseeinpcb(req->td->td_ucred, inp); 1213 if (error == 0) { 1214 in_pcbref(inp); 1215 inp_list[i++] = inp; 1216 } 1217 } 1218 INP_WUNLOCK(inp); 1219 } 1220 INP_INFO_RUNLOCK(&V_tcbinfo); 1221 n = i; 1222 1223 error = 0; 1224 for (i = 0; i < n; i++) { 1225 inp = inp_list[i]; 1226 INP_RLOCK(inp); 1227 if (inp->inp_gencnt <= gencnt) { 1228 struct xtcpcb xt; 1229 void *inp_ppcb; 1230 1231 bzero(&xt, sizeof(xt)); 1232 xt.xt_len = sizeof xt; 1233 /* XXX should avoid extra copy */ 1234 bcopy(inp, &xt.xt_inp, sizeof *inp); 1235 inp_ppcb = inp->inp_ppcb; 1236 if (inp_ppcb == NULL) 1237 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1238 else if (inp->inp_flags & INP_TIMEWAIT) { 1239 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1240 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1241 } else { 1242 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1243 if (xt.xt_tp.t_timers) 1244 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1245 } 1246 if (inp->inp_socket != NULL) 1247 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1248 else { 1249 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1250 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1251 } 1252 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1253 INP_RUNLOCK(inp); 1254 error = SYSCTL_OUT(req, &xt, sizeof xt); 1255 } else 1256 INP_RUNLOCK(inp); 1257 } 1258 INP_INFO_WLOCK(&V_tcbinfo); 1259 for (i = 0; i < n; i++) { 1260 inp = inp_list[i]; 1261 INP_RLOCK(inp); 1262 if (!in_pcbrele_rlocked(inp)) 1263 INP_RUNLOCK(inp); 1264 } 1265 INP_INFO_WUNLOCK(&V_tcbinfo); 1266 1267 if (!error) { 1268 /* 1269 * Give the user an updated idea of our state. 1270 * If the generation differs from what we told 1271 * her before, she knows that something happened 1272 * while we were processing this request, and it 1273 * might be necessary to retry. 1274 */ 1275 INP_INFO_RLOCK(&V_tcbinfo); 1276 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1277 xig.xig_sogen = so_gencnt; 1278 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1279 INP_INFO_RUNLOCK(&V_tcbinfo); 1280 error = SYSCTL_OUT(req, &xig, sizeof xig); 1281 } 1282 free(inp_list, M_TEMP); 1283 return (error); 1284} 1285 1286SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1287 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1288 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1289 1290#ifdef INET 1291static int 1292tcp_getcred(SYSCTL_HANDLER_ARGS) 1293{ 1294 struct xucred xuc; 1295 struct sockaddr_in addrs[2]; 1296 struct inpcb *inp; 1297 int error; 1298 1299 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1300 if (error) 1301 return (error); 1302 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1303 if (error) 1304 return (error); 1305 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1306 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1307 if (inp != NULL) { 1308 if (inp->inp_socket == NULL) 1309 error = ENOENT; 1310 if (error == 0) 1311 error = cr_canseeinpcb(req->td->td_ucred, inp); 1312 if (error == 0) 1313 cru2x(inp->inp_cred, &xuc); 1314 INP_RUNLOCK(inp); 1315 } else 1316 error = ENOENT; 1317 if (error == 0) 1318 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1319 return (error); 1320} 1321 1322SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1323 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1324 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1325#endif /* INET */ 1326 1327#ifdef INET6 1328static int 1329tcp6_getcred(SYSCTL_HANDLER_ARGS) 1330{ 1331 struct xucred xuc; 1332 struct sockaddr_in6 addrs[2]; 1333 struct inpcb *inp; 1334 int error; 1335#ifdef INET 1336 int mapped = 0; 1337#endif 1338 1339 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1340 if (error) 1341 return (error); 1342 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1343 if (error) 1344 return (error); 1345 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1346 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1347 return (error); 1348 } 1349 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1350#ifdef INET 1351 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1352 mapped = 1; 1353 else 1354#endif 1355 return (EINVAL); 1356 } 1357 1358#ifdef INET 1359 if (mapped == 1) 1360 inp = in_pcblookup(&V_tcbinfo, 1361 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1362 addrs[1].sin6_port, 1363 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1364 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1365 else 1366#endif 1367 inp = in6_pcblookup(&V_tcbinfo, 1368 &addrs[1].sin6_addr, addrs[1].sin6_port, 1369 &addrs[0].sin6_addr, addrs[0].sin6_port, 1370 INPLOOKUP_RLOCKPCB, NULL); 1371 if (inp != NULL) { 1372 if (inp->inp_socket == NULL) 1373 error = ENOENT; 1374 if (error == 0) 1375 error = cr_canseeinpcb(req->td->td_ucred, inp); 1376 if (error == 0) 1377 cru2x(inp->inp_cred, &xuc); 1378 INP_RUNLOCK(inp); 1379 } else 1380 error = ENOENT; 1381 if (error == 0) 1382 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1383 return (error); 1384} 1385 1386SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1387 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1388 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1389#endif /* INET6 */ 1390 1391 1392#ifdef INET 1393void 1394tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1395{ 1396 struct ip *ip = vip; 1397 struct tcphdr *th; 1398 struct in_addr faddr; 1399 struct inpcb *inp; 1400 struct tcpcb *tp; 1401 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1402 struct icmp *icp; 1403 struct in_conninfo inc; 1404 tcp_seq icmp_tcp_seq; 1405 int mtu; 1406 1407 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1408 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1409 return; 1410 1411 if (cmd == PRC_MSGSIZE) 1412 notify = tcp_mtudisc_notify; 1413 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1414 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1415 notify = tcp_drop_syn_sent; 1416 /* 1417 * Redirects don't need to be handled up here. 1418 */ 1419 else if (PRC_IS_REDIRECT(cmd)) 1420 return; 1421 /* 1422 * Source quench is depreciated. 1423 */ 1424 else if (cmd == PRC_QUENCH) 1425 return; 1426 /* 1427 * Hostdead is ugly because it goes linearly through all PCBs. 1428 * XXX: We never get this from ICMP, otherwise it makes an 1429 * excellent DoS attack on machines with many connections. 1430 */ 1431 else if (cmd == PRC_HOSTDEAD) 1432 ip = NULL; 1433 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1434 return; 1435 if (ip != NULL) { 1436 icp = (struct icmp *)((caddr_t)ip 1437 - offsetof(struct icmp, icmp_ip)); 1438 th = (struct tcphdr *)((caddr_t)ip 1439 + (ip->ip_hl << 2)); 1440 INP_INFO_WLOCK(&V_tcbinfo); 1441 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, 1442 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1443 if (inp != NULL) { 1444 if (!(inp->inp_flags & INP_TIMEWAIT) && 1445 !(inp->inp_flags & INP_DROPPED) && 1446 !(inp->inp_socket == NULL)) { 1447 icmp_tcp_seq = htonl(th->th_seq); 1448 tp = intotcpcb(inp); 1449 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1450 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1451 if (cmd == PRC_MSGSIZE) { 1452 /* 1453 * MTU discovery: 1454 * If we got a needfrag set the MTU 1455 * in the route to the suggested new 1456 * value (if given) and then notify. 1457 */ 1458 bzero(&inc, sizeof(inc)); 1459 inc.inc_faddr = faddr; 1460 inc.inc_fibnum = 1461 inp->inp_inc.inc_fibnum; 1462 1463 mtu = ntohs(icp->icmp_nextmtu); 1464 /* 1465 * If no alternative MTU was 1466 * proposed, try the next smaller 1467 * one. 1468 */ 1469 if (!mtu) 1470 mtu = ip_next_mtu( 1471 ntohs(ip->ip_len), 1); 1472 if (mtu < V_tcp_minmss 1473 + sizeof(struct tcpiphdr)) 1474 mtu = V_tcp_minmss 1475 + sizeof(struct tcpiphdr); 1476 /* 1477 * Only cache the MTU if it 1478 * is smaller than the interface 1479 * or route MTU. tcp_mtudisc() 1480 * will do right thing by itself. 1481 */ 1482 if (mtu <= tcp_maxmtu(&inc, NULL)) 1483 tcp_hc_updatemtu(&inc, mtu); 1484 tcp_mtudisc(inp, mtu); 1485 } else 1486 inp = (*notify)(inp, 1487 inetctlerrmap[cmd]); 1488 } 1489 } 1490 if (inp != NULL) 1491 INP_WUNLOCK(inp); 1492 } else { 1493 bzero(&inc, sizeof(inc)); 1494 inc.inc_fport = th->th_dport; 1495 inc.inc_lport = th->th_sport; 1496 inc.inc_faddr = faddr; 1497 inc.inc_laddr = ip->ip_src; 1498 syncache_unreach(&inc, th); 1499 } 1500 INP_INFO_WUNLOCK(&V_tcbinfo); 1501 } else 1502 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1503} 1504#endif /* INET */ 1505 1506#ifdef INET6 1507void 1508tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1509{ 1510 struct tcphdr th; 1511 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1512 struct ip6_hdr *ip6; 1513 struct mbuf *m; 1514 struct ip6ctlparam *ip6cp = NULL; 1515 const struct sockaddr_in6 *sa6_src = NULL; 1516 int off; 1517 struct tcp_portonly { 1518 u_int16_t th_sport; 1519 u_int16_t th_dport; 1520 } *thp; 1521 1522 if (sa->sa_family != AF_INET6 || 1523 sa->sa_len != sizeof(struct sockaddr_in6)) 1524 return; 1525 1526 if (cmd == PRC_MSGSIZE) 1527 notify = tcp_mtudisc_notify; 1528 else if (!PRC_IS_REDIRECT(cmd) && 1529 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1530 return; 1531 /* Source quench is depreciated. */ 1532 else if (cmd == PRC_QUENCH) 1533 return; 1534 1535 /* if the parameter is from icmp6, decode it. */ 1536 if (d != NULL) { 1537 ip6cp = (struct ip6ctlparam *)d; 1538 m = ip6cp->ip6c_m; 1539 ip6 = ip6cp->ip6c_ip6; 1540 off = ip6cp->ip6c_off; 1541 sa6_src = ip6cp->ip6c_src; 1542 } else { 1543 m = NULL; 1544 ip6 = NULL; 1545 off = 0; /* fool gcc */ 1546 sa6_src = &sa6_any; 1547 } 1548 1549 if (ip6 != NULL) { 1550 struct in_conninfo inc; 1551 /* 1552 * XXX: We assume that when IPV6 is non NULL, 1553 * M and OFF are valid. 1554 */ 1555 1556 /* check if we can safely examine src and dst ports */ 1557 if (m->m_pkthdr.len < off + sizeof(*thp)) 1558 return; 1559 1560 bzero(&th, sizeof(th)); 1561 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1562 1563 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1564 (struct sockaddr *)ip6cp->ip6c_src, 1565 th.th_sport, cmd, NULL, notify); 1566 1567 bzero(&inc, sizeof(inc)); 1568 inc.inc_fport = th.th_dport; 1569 inc.inc_lport = th.th_sport; 1570 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1571 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1572 inc.inc_flags |= INC_ISIPV6; 1573 INP_INFO_WLOCK(&V_tcbinfo); 1574 syncache_unreach(&inc, &th); 1575 INP_INFO_WUNLOCK(&V_tcbinfo); 1576 } else 1577 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1578 0, cmd, NULL, notify); 1579} 1580#endif /* INET6 */ 1581 1582 1583/* 1584 * Following is where TCP initial sequence number generation occurs. 1585 * 1586 * There are two places where we must use initial sequence numbers: 1587 * 1. In SYN-ACK packets. 1588 * 2. In SYN packets. 1589 * 1590 * All ISNs for SYN-ACK packets are generated by the syncache. See 1591 * tcp_syncache.c for details. 1592 * 1593 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1594 * depends on this property. In addition, these ISNs should be 1595 * unguessable so as to prevent connection hijacking. To satisfy 1596 * the requirements of this situation, the algorithm outlined in 1597 * RFC 1948 is used, with only small modifications. 1598 * 1599 * Implementation details: 1600 * 1601 * Time is based off the system timer, and is corrected so that it 1602 * increases by one megabyte per second. This allows for proper 1603 * recycling on high speed LANs while still leaving over an hour 1604 * before rollover. 1605 * 1606 * As reading the *exact* system time is too expensive to be done 1607 * whenever setting up a TCP connection, we increment the time 1608 * offset in two ways. First, a small random positive increment 1609 * is added to isn_offset for each connection that is set up. 1610 * Second, the function tcp_isn_tick fires once per clock tick 1611 * and increments isn_offset as necessary so that sequence numbers 1612 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1613 * random positive increments serve only to ensure that the same 1614 * exact sequence number is never sent out twice (as could otherwise 1615 * happen when a port is recycled in less than the system tick 1616 * interval.) 1617 * 1618 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1619 * between seeding of isn_secret. This is normally set to zero, 1620 * as reseeding should not be necessary. 1621 * 1622 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1623 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1624 * general, this means holding an exclusive (write) lock. 1625 */ 1626 1627#define ISN_BYTES_PER_SECOND 1048576 1628#define ISN_STATIC_INCREMENT 4096 1629#define ISN_RANDOM_INCREMENT (4096 - 1) 1630 1631static VNET_DEFINE(u_char, isn_secret[32]); 1632static VNET_DEFINE(int, isn_last); 1633static VNET_DEFINE(int, isn_last_reseed); 1634static VNET_DEFINE(u_int32_t, isn_offset); 1635static VNET_DEFINE(u_int32_t, isn_offset_old); 1636 1637#define V_isn_secret VNET(isn_secret) 1638#define V_isn_last VNET(isn_last) 1639#define V_isn_last_reseed VNET(isn_last_reseed) 1640#define V_isn_offset VNET(isn_offset) 1641#define V_isn_offset_old VNET(isn_offset_old) 1642 1643tcp_seq 1644tcp_new_isn(struct tcpcb *tp) 1645{ 1646 MD5_CTX isn_ctx; 1647 u_int32_t md5_buffer[4]; 1648 tcp_seq new_isn; 1649 u_int32_t projected_offset; 1650 1651 INP_WLOCK_ASSERT(tp->t_inpcb); 1652 1653 ISN_LOCK(); 1654 /* Seed if this is the first use, reseed if requested. */ 1655 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1656 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1657 < (u_int)ticks))) { 1658 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1659 V_isn_last_reseed = ticks; 1660 } 1661 1662 /* Compute the md5 hash and return the ISN. */ 1663 MD5Init(&isn_ctx); 1664 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1665 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1666#ifdef INET6 1667 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1669 sizeof(struct in6_addr)); 1670 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1671 sizeof(struct in6_addr)); 1672 } else 1673#endif 1674 { 1675 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1676 sizeof(struct in_addr)); 1677 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1678 sizeof(struct in_addr)); 1679 } 1680 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1681 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1682 new_isn = (tcp_seq) md5_buffer[0]; 1683 V_isn_offset += ISN_STATIC_INCREMENT + 1684 (arc4random() & ISN_RANDOM_INCREMENT); 1685 if (ticks != V_isn_last) { 1686 projected_offset = V_isn_offset_old + 1687 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1688 if (SEQ_GT(projected_offset, V_isn_offset)) 1689 V_isn_offset = projected_offset; 1690 V_isn_offset_old = V_isn_offset; 1691 V_isn_last = ticks; 1692 } 1693 new_isn += V_isn_offset; 1694 ISN_UNLOCK(); 1695 return (new_isn); 1696} 1697 1698/* 1699 * When a specific ICMP unreachable message is received and the 1700 * connection state is SYN-SENT, drop the connection. This behavior 1701 * is controlled by the icmp_may_rst sysctl. 1702 */ 1703struct inpcb * 1704tcp_drop_syn_sent(struct inpcb *inp, int errno) 1705{ 1706 struct tcpcb *tp; 1707 1708 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1709 INP_WLOCK_ASSERT(inp); 1710 1711 if ((inp->inp_flags & INP_TIMEWAIT) || 1712 (inp->inp_flags & INP_DROPPED)) 1713 return (inp); 1714 1715 tp = intotcpcb(inp); 1716 if (tp->t_state != TCPS_SYN_SENT) 1717 return (inp); 1718 1719 tp = tcp_drop(tp, errno); 1720 if (tp != NULL) 1721 return (inp); 1722 else 1723 return (NULL); 1724} 1725 1726/* 1727 * When `need fragmentation' ICMP is received, update our idea of the MSS 1728 * based on the new value. Also nudge TCP to send something, since we 1729 * know the packet we just sent was dropped. 1730 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1731 */ 1732static struct inpcb * 1733tcp_mtudisc_notify(struct inpcb *inp, int error) 1734{ 1735 1736 return (tcp_mtudisc(inp, -1)); 1737} 1738 1739struct inpcb * 1740tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1741{ 1742 struct tcpcb *tp; 1743 struct socket *so; 1744 1745 INP_WLOCK_ASSERT(inp); 1746 if ((inp->inp_flags & INP_TIMEWAIT) || 1747 (inp->inp_flags & INP_DROPPED)) 1748 return (inp); 1749 1750 tp = intotcpcb(inp); 1751 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1752 1753 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1754 1755 so = inp->inp_socket; 1756 SOCKBUF_LOCK(&so->so_snd); 1757 /* If the mss is larger than the socket buffer, decrease the mss. */ 1758 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1759 tp->t_maxseg = so->so_snd.sb_hiwat; 1760 SOCKBUF_UNLOCK(&so->so_snd); 1761 1762 TCPSTAT_INC(tcps_mturesent); 1763 tp->t_rtttime = 0; 1764 tp->snd_nxt = tp->snd_una; 1765 tcp_free_sackholes(tp); 1766 tp->snd_recover = tp->snd_max; 1767 if (tp->t_flags & TF_SACK_PERMIT) 1768 EXIT_FASTRECOVERY(tp->t_flags); 1769 tcp_output(tp); 1770 return (inp); 1771} 1772 1773#ifdef INET 1774/* 1775 * Look-up the routing entry to the peer of this inpcb. If no route 1776 * is found and it cannot be allocated, then return 0. This routine 1777 * is called by TCP routines that access the rmx structure and by 1778 * tcp_mss_update to get the peer/interface MTU. 1779 */ 1780u_long 1781tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 1782{ 1783 struct route sro; 1784 struct sockaddr_in *dst; 1785 struct ifnet *ifp; 1786 u_long maxmtu = 0; 1787 1788 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1789 1790 bzero(&sro, sizeof(sro)); 1791 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1792 dst = (struct sockaddr_in *)&sro.ro_dst; 1793 dst->sin_family = AF_INET; 1794 dst->sin_len = sizeof(*dst); 1795 dst->sin_addr = inc->inc_faddr; 1796 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1797 } 1798 if (sro.ro_rt != NULL) { 1799 ifp = sro.ro_rt->rt_ifp; 1800 if (sro.ro_rt->rt_mtu == 0) 1801 maxmtu = ifp->if_mtu; 1802 else 1803 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 1804 1805 /* Report additional interface capabilities. */ 1806 if (cap != NULL) { 1807 if (ifp->if_capenable & IFCAP_TSO4 && 1808 ifp->if_hwassist & CSUM_TSO) { 1809 cap->ifcap |= CSUM_TSO; 1810 cap->tsomax = ifp->if_hw_tsomax; 1811 } 1812 } 1813 RTFREE(sro.ro_rt); 1814 } 1815 return (maxmtu); 1816} 1817#endif /* INET */ 1818 1819#ifdef INET6 1820u_long 1821tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 1822{ 1823 struct route_in6 sro6; 1824 struct ifnet *ifp; 1825 u_long maxmtu = 0; 1826 1827 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1828 1829 bzero(&sro6, sizeof(sro6)); 1830 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1831 sro6.ro_dst.sin6_family = AF_INET6; 1832 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1833 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1834 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 1835 } 1836 if (sro6.ro_rt != NULL) { 1837 ifp = sro6.ro_rt->rt_ifp; 1838 if (sro6.ro_rt->rt_mtu == 0) 1839 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1840 else 1841 maxmtu = min(sro6.ro_rt->rt_mtu, 1842 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1843 1844 /* Report additional interface capabilities. */ 1845 if (cap != NULL) { 1846 if (ifp->if_capenable & IFCAP_TSO6 && 1847 ifp->if_hwassist & CSUM_TSO) { 1848 cap->ifcap |= CSUM_TSO; 1849 cap->tsomax = ifp->if_hw_tsomax; 1850 } 1851 } 1852 RTFREE(sro6.ro_rt); 1853 } 1854 1855 return (maxmtu); 1856} 1857#endif /* INET6 */ 1858 1859#ifdef IPSEC 1860/* compute ESP/AH header size for TCP, including outer IP header. */ 1861size_t 1862ipsec_hdrsiz_tcp(struct tcpcb *tp) 1863{ 1864 struct inpcb *inp; 1865 struct mbuf *m; 1866 size_t hdrsiz; 1867 struct ip *ip; 1868#ifdef INET6 1869 struct ip6_hdr *ip6; 1870#endif 1871 struct tcphdr *th; 1872 1873 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1874 return (0); 1875 m = m_gethdr(M_NOWAIT, MT_DATA); 1876 if (!m) 1877 return (0); 1878 1879#ifdef INET6 1880 if ((inp->inp_vflag & INP_IPV6) != 0) { 1881 ip6 = mtod(m, struct ip6_hdr *); 1882 th = (struct tcphdr *)(ip6 + 1); 1883 m->m_pkthdr.len = m->m_len = 1884 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1885 tcpip_fillheaders(inp, ip6, th); 1886 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1887 } else 1888#endif /* INET6 */ 1889 { 1890 ip = mtod(m, struct ip *); 1891 th = (struct tcphdr *)(ip + 1); 1892 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1893 tcpip_fillheaders(inp, ip, th); 1894 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1895 } 1896 1897 m_free(m); 1898 return (hdrsiz); 1899} 1900#endif /* IPSEC */ 1901 1902#ifdef TCP_SIGNATURE 1903/* 1904 * Callback function invoked by m_apply() to digest TCP segment data 1905 * contained within an mbuf chain. 1906 */ 1907static int 1908tcp_signature_apply(void *fstate, void *data, u_int len) 1909{ 1910 1911 MD5Update(fstate, (u_char *)data, len); 1912 return (0); 1913} 1914 1915/* 1916 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1917 * 1918 * Parameters: 1919 * m pointer to head of mbuf chain 1920 * _unused 1921 * len length of TCP segment data, excluding options 1922 * optlen length of TCP segment options 1923 * buf pointer to storage for computed MD5 digest 1924 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1925 * 1926 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1927 * When called from tcp_input(), we can be sure that th_sum has been 1928 * zeroed out and verified already. 1929 * 1930 * Return 0 if successful, otherwise return -1. 1931 * 1932 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1933 * search with the destination IP address, and a 'magic SPI' to be 1934 * determined by the application. This is hardcoded elsewhere to 1179 1935 * right now. Another branch of this code exists which uses the SPD to 1936 * specify per-application flows but it is unstable. 1937 */ 1938int 1939tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1940 u_char *buf, u_int direction) 1941{ 1942 union sockaddr_union dst; 1943#ifdef INET 1944 struct ippseudo ippseudo; 1945#endif 1946 MD5_CTX ctx; 1947 int doff; 1948 struct ip *ip; 1949#ifdef INET 1950 struct ipovly *ipovly; 1951#endif 1952 struct secasvar *sav; 1953 struct tcphdr *th; 1954#ifdef INET6 1955 struct ip6_hdr *ip6; 1956 struct in6_addr in6; 1957 char ip6buf[INET6_ADDRSTRLEN]; 1958 uint32_t plen; 1959 uint16_t nhdr; 1960#endif 1961 u_short savecsum; 1962 1963 KASSERT(m != NULL, ("NULL mbuf chain")); 1964 KASSERT(buf != NULL, ("NULL signature pointer")); 1965 1966 /* Extract the destination from the IP header in the mbuf. */ 1967 bzero(&dst, sizeof(union sockaddr_union)); 1968 ip = mtod(m, struct ip *); 1969#ifdef INET6 1970 ip6 = NULL; /* Make the compiler happy. */ 1971#endif 1972 switch (ip->ip_v) { 1973#ifdef INET 1974 case IPVERSION: 1975 dst.sa.sa_len = sizeof(struct sockaddr_in); 1976 dst.sa.sa_family = AF_INET; 1977 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 1978 ip->ip_src : ip->ip_dst; 1979 break; 1980#endif 1981#ifdef INET6 1982 case (IPV6_VERSION >> 4): 1983 ip6 = mtod(m, struct ip6_hdr *); 1984 dst.sa.sa_len = sizeof(struct sockaddr_in6); 1985 dst.sa.sa_family = AF_INET6; 1986 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 1987 ip6->ip6_src : ip6->ip6_dst; 1988 break; 1989#endif 1990 default: 1991 return (EINVAL); 1992 /* NOTREACHED */ 1993 break; 1994 } 1995 1996 /* Look up an SADB entry which matches the address of the peer. */ 1997 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 1998 if (sav == NULL) { 1999 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2000 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2001#ifdef INET6 2002 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2003 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2004#endif 2005 "(unsupported)")); 2006 return (EINVAL); 2007 } 2008 2009 MD5Init(&ctx); 2010 /* 2011 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2012 * 2013 * XXX The ippseudo header MUST be digested in network byte order, 2014 * or else we'll fail the regression test. Assume all fields we've 2015 * been doing arithmetic on have been in host byte order. 2016 * XXX One cannot depend on ipovly->ih_len here. When called from 2017 * tcp_output(), the underlying ip_len member has not yet been set. 2018 */ 2019 switch (ip->ip_v) { 2020#ifdef INET 2021 case IPVERSION: 2022 ipovly = (struct ipovly *)ip; 2023 ippseudo.ippseudo_src = ipovly->ih_src; 2024 ippseudo.ippseudo_dst = ipovly->ih_dst; 2025 ippseudo.ippseudo_pad = 0; 2026 ippseudo.ippseudo_p = IPPROTO_TCP; 2027 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2028 optlen); 2029 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2030 2031 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2032 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2033 break; 2034#endif 2035#ifdef INET6 2036 /* 2037 * RFC 2385, 2.0 Proposal 2038 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2039 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2040 * extended next header value (to form 32 bits), and 32-bit segment 2041 * length. 2042 * Note: Upper-Layer Packet Length comes before Next Header. 2043 */ 2044 case (IPV6_VERSION >> 4): 2045 in6 = ip6->ip6_src; 2046 in6_clearscope(&in6); 2047 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2048 in6 = ip6->ip6_dst; 2049 in6_clearscope(&in6); 2050 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2051 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2052 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2053 nhdr = 0; 2054 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2055 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2056 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2057 nhdr = IPPROTO_TCP; 2058 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2059 2060 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2061 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2062 break; 2063#endif 2064 default: 2065 return (EINVAL); 2066 /* NOTREACHED */ 2067 break; 2068 } 2069 2070 2071 /* 2072 * Step 2: Update MD5 hash with TCP header, excluding options. 2073 * The TCP checksum must be set to zero. 2074 */ 2075 savecsum = th->th_sum; 2076 th->th_sum = 0; 2077 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2078 th->th_sum = savecsum; 2079 2080 /* 2081 * Step 3: Update MD5 hash with TCP segment data. 2082 * Use m_apply() to avoid an early m_pullup(). 2083 */ 2084 if (len > 0) 2085 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2086 2087 /* 2088 * Step 4: Update MD5 hash with shared secret. 2089 */ 2090 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2091 MD5Final(buf, &ctx); 2092 2093 key_sa_recordxfer(sav, m); 2094 KEY_FREESAV(&sav); 2095 return (0); 2096} 2097 2098/* 2099 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2100 * 2101 * Parameters: 2102 * m pointer to head of mbuf chain 2103 * len length of TCP segment data, excluding options 2104 * optlen length of TCP segment options 2105 * buf pointer to storage for computed MD5 digest 2106 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2107 * 2108 * Return 1 if successful, otherwise return 0. 2109 */ 2110int 2111tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2112 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2113{ 2114 char tmpdigest[TCP_SIGLEN]; 2115 2116 if (tcp_sig_checksigs == 0) 2117 return (1); 2118 if ((tcpbflag & TF_SIGNATURE) == 0) { 2119 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2120 2121 /* 2122 * If this socket is not expecting signature but 2123 * the segment contains signature just fail. 2124 */ 2125 TCPSTAT_INC(tcps_sig_err_sigopt); 2126 TCPSTAT_INC(tcps_sig_rcvbadsig); 2127 return (0); 2128 } 2129 2130 /* Signature is not expected, and not present in segment. */ 2131 return (1); 2132 } 2133 2134 /* 2135 * If this socket is expecting signature but the segment does not 2136 * contain any just fail. 2137 */ 2138 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2139 TCPSTAT_INC(tcps_sig_err_nosigopt); 2140 TCPSTAT_INC(tcps_sig_rcvbadsig); 2141 return (0); 2142 } 2143 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2144 IPSEC_DIR_INBOUND) == -1) { 2145 TCPSTAT_INC(tcps_sig_err_buildsig); 2146 TCPSTAT_INC(tcps_sig_rcvbadsig); 2147 return (0); 2148 } 2149 2150 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2151 TCPSTAT_INC(tcps_sig_rcvbadsig); 2152 return (0); 2153 } 2154 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2155 return (1); 2156} 2157#endif /* TCP_SIGNATURE */ 2158 2159static int 2160sysctl_drop(SYSCTL_HANDLER_ARGS) 2161{ 2162 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2163 struct sockaddr_storage addrs[2]; 2164 struct inpcb *inp; 2165 struct tcpcb *tp; 2166 struct tcptw *tw; 2167 struct sockaddr_in *fin, *lin; 2168#ifdef INET6 2169 struct sockaddr_in6 *fin6, *lin6; 2170#endif 2171 int error; 2172 2173 inp = NULL; 2174 fin = lin = NULL; 2175#ifdef INET6 2176 fin6 = lin6 = NULL; 2177#endif 2178 error = 0; 2179 2180 if (req->oldptr != NULL || req->oldlen != 0) 2181 return (EINVAL); 2182 if (req->newptr == NULL) 2183 return (EPERM); 2184 if (req->newlen < sizeof(addrs)) 2185 return (ENOMEM); 2186 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2187 if (error) 2188 return (error); 2189 2190 switch (addrs[0].ss_family) { 2191#ifdef INET6 2192 case AF_INET6: 2193 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2194 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2195 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2196 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2197 return (EINVAL); 2198 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2199 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2200 return (EINVAL); 2201 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2202 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2203 fin = (struct sockaddr_in *)&addrs[0]; 2204 lin = (struct sockaddr_in *)&addrs[1]; 2205 break; 2206 } 2207 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2208 if (error) 2209 return (error); 2210 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2211 if (error) 2212 return (error); 2213 break; 2214#endif 2215#ifdef INET 2216 case AF_INET: 2217 fin = (struct sockaddr_in *)&addrs[0]; 2218 lin = (struct sockaddr_in *)&addrs[1]; 2219 if (fin->sin_len != sizeof(struct sockaddr_in) || 2220 lin->sin_len != sizeof(struct sockaddr_in)) 2221 return (EINVAL); 2222 break; 2223#endif 2224 default: 2225 return (EINVAL); 2226 } 2227 INP_INFO_WLOCK(&V_tcbinfo); 2228 switch (addrs[0].ss_family) { 2229#ifdef INET6 2230 case AF_INET6: 2231 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2232 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2233 INPLOOKUP_WLOCKPCB, NULL); 2234 break; 2235#endif 2236#ifdef INET 2237 case AF_INET: 2238 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2239 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2240 break; 2241#endif 2242 } 2243 if (inp != NULL) { 2244 if (inp->inp_flags & INP_TIMEWAIT) { 2245 /* 2246 * XXXRW: There currently exists a state where an 2247 * inpcb is present, but its timewait state has been 2248 * discarded. For now, don't allow dropping of this 2249 * type of inpcb. 2250 */ 2251 tw = intotw(inp); 2252 if (tw != NULL) 2253 tcp_twclose(tw, 0); 2254 else 2255 INP_WUNLOCK(inp); 2256 } else if (!(inp->inp_flags & INP_DROPPED) && 2257 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2258 tp = intotcpcb(inp); 2259 tp = tcp_drop(tp, ECONNABORTED); 2260 if (tp != NULL) 2261 INP_WUNLOCK(inp); 2262 } else 2263 INP_WUNLOCK(inp); 2264 } else 2265 error = ESRCH; 2266 INP_INFO_WUNLOCK(&V_tcbinfo); 2267 return (error); 2268} 2269 2270SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2271 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2272 0, sysctl_drop, "", "Drop TCP connection"); 2273 2274/* 2275 * Generate a standardized TCP log line for use throughout the 2276 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2277 * allow use in the interrupt context. 2278 * 2279 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2280 * NB: The function may return NULL if memory allocation failed. 2281 * 2282 * Due to header inclusion and ordering limitations the struct ip 2283 * and ip6_hdr pointers have to be passed as void pointers. 2284 */ 2285char * 2286tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2287 const void *ip6hdr) 2288{ 2289 2290 /* Is logging enabled? */ 2291 if (tcp_log_in_vain == 0) 2292 return (NULL); 2293 2294 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2295} 2296 2297char * 2298tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2299 const void *ip6hdr) 2300{ 2301 2302 /* Is logging enabled? */ 2303 if (tcp_log_debug == 0) 2304 return (NULL); 2305 2306 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2307} 2308 2309static char * 2310tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2311 const void *ip6hdr) 2312{ 2313 char *s, *sp; 2314 size_t size; 2315 struct ip *ip; 2316#ifdef INET6 2317 const struct ip6_hdr *ip6; 2318 2319 ip6 = (const struct ip6_hdr *)ip6hdr; 2320#endif /* INET6 */ 2321 ip = (struct ip *)ip4hdr; 2322 2323 /* 2324 * The log line looks like this: 2325 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2326 */ 2327 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2328 sizeof(PRINT_TH_FLAGS) + 1 + 2329#ifdef INET6 2330 2 * INET6_ADDRSTRLEN; 2331#else 2332 2 * INET_ADDRSTRLEN; 2333#endif /* INET6 */ 2334 2335 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2336 if (s == NULL) 2337 return (NULL); 2338 2339 strcat(s, "TCP: ["); 2340 sp = s + strlen(s); 2341 2342 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2343 inet_ntoa_r(inc->inc_faddr, sp); 2344 sp = s + strlen(s); 2345 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2346 sp = s + strlen(s); 2347 inet_ntoa_r(inc->inc_laddr, sp); 2348 sp = s + strlen(s); 2349 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2350#ifdef INET6 2351 } else if (inc) { 2352 ip6_sprintf(sp, &inc->inc6_faddr); 2353 sp = s + strlen(s); 2354 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2355 sp = s + strlen(s); 2356 ip6_sprintf(sp, &inc->inc6_laddr); 2357 sp = s + strlen(s); 2358 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2359 } else if (ip6 && th) { 2360 ip6_sprintf(sp, &ip6->ip6_src); 2361 sp = s + strlen(s); 2362 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2363 sp = s + strlen(s); 2364 ip6_sprintf(sp, &ip6->ip6_dst); 2365 sp = s + strlen(s); 2366 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2367#endif /* INET6 */ 2368#ifdef INET 2369 } else if (ip && th) { 2370 inet_ntoa_r(ip->ip_src, sp); 2371 sp = s + strlen(s); 2372 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2373 sp = s + strlen(s); 2374 inet_ntoa_r(ip->ip_dst, sp); 2375 sp = s + strlen(s); 2376 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2377#endif /* INET */ 2378 } else { 2379 free(s, M_TCPLOG); 2380 return (NULL); 2381 } 2382 sp = s + strlen(s); 2383 if (th) 2384 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2385 if (*(s + size - 1) != '\0') 2386 panic("%s: string too long", __func__); 2387 return (s); 2388} 2389 2390/* 2391 * A subroutine which makes it easy to track TCP state changes with DTrace. 2392 * This function shouldn't be called for t_state initializations that don't 2393 * correspond to actual TCP state transitions. 2394 */ 2395void 2396tcp_state_change(struct tcpcb *tp, int newstate) 2397{ 2398#if defined(KDTRACE_HOOKS) 2399 int pstate = tp->t_state; 2400#endif 2401 2402 tp->t_state = newstate; 2403 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2404} 2405