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