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_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 142 CTLFLAG_VNET | 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_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 164 CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | 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_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | 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_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | 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 void tcp_mtudisc(struct inpcb *, int); 232 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 233 void *ip4hdr, const void *ip6hdr); 234 static void tcp_timer_discard(struct tcpcb *, uint32_t); 235 236 /* 237 * Target size of TCP PCB hash tables. Must be a power of two. 238 * 239 * Note that this can be overridden by the kernel environment 240 * variable net.inet.tcp.tcbhashsize 241 */ 242 #ifndef TCBHASHSIZE 243 #define TCBHASHSIZE 0 244 #endif 245 246 /* 247 * XXX 248 * Callouts should be moved into struct tcp directly. They are currently 249 * separate because the tcpcb structure is exported to userland for sysctl 250 * parsing purposes, which do not know about callouts. 251 */ 252 struct tcpcb_mem { 253 struct tcpcb tcb; 254 struct tcp_timer tt; 255 struct cc_var ccv; 256 struct osd osd; 257 }; 258 259 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 260 #define V_tcpcb_zone VNET(tcpcb_zone) 261 262 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 263 static struct mtx isn_mtx; 264 265 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 266 #define ISN_LOCK() mtx_lock(&isn_mtx) 267 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 268 269 /* 270 * TCP initialization. 271 */ 272 static void 273 tcp_zone_change(void *tag) 274 { 275 276 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 277 uma_zone_set_max(V_tcpcb_zone, maxsockets); 278 tcp_tw_zone_change(); 279 } 280 281 static int 282 tcp_inpcb_init(void *mem, int size, int flags) 283 { 284 struct inpcb *inp = mem; 285 286 INP_LOCK_INIT(inp, "inp", "tcpinp"); 287 return (0); 288 } 289 290 /* 291 * Take a value and get the next power of 2 that doesn't overflow. 292 * Used to size the tcp_inpcb hash buckets. 293 */ 294 static int 295 maketcp_hashsize(int size) 296 { 297 int hashsize; 298 299 /* 300 * auto tune. 301 * get the next power of 2 higher than maxsockets. 302 */ 303 hashsize = 1 << fls(size); 304 /* catch overflow, and just go one power of 2 smaller */ 305 if (hashsize < size) { 306 hashsize = 1 << (fls(size) - 1); 307 } 308 return (hashsize); 309 } 310 311 void 312 tcp_init(void) 313 { 314 const char *tcbhash_tuneable; 315 int hashsize; 316 317 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 318 319 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 320 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 321 printf("%s: WARNING: unable to register helper hook\n", __func__); 322 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 323 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 324 printf("%s: WARNING: unable to register helper hook\n", __func__); 325 326 hashsize = TCBHASHSIZE; 327 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 328 if (hashsize == 0) { 329 /* 330 * Auto tune the hash size based on maxsockets. 331 * A perfect hash would have a 1:1 mapping 332 * (hashsize = maxsockets) however it's been 333 * suggested that O(2) average is better. 334 */ 335 hashsize = maketcp_hashsize(maxsockets / 4); 336 /* 337 * Our historical default is 512, 338 * do not autotune lower than this. 339 */ 340 if (hashsize < 512) 341 hashsize = 512; 342 if (bootverbose) 343 printf("%s: %s auto tuned to %d\n", __func__, 344 tcbhash_tuneable, hashsize); 345 } 346 /* 347 * We require a hashsize to be a power of two. 348 * Previously if it was not a power of two we would just reset it 349 * back to 512, which could be a nasty surprise if you did not notice 350 * the error message. 351 * Instead what we do is clip it to the closest power of two lower 352 * than the specified hash value. 353 */ 354 if (!powerof2(hashsize)) { 355 int oldhashsize = hashsize; 356 357 hashsize = maketcp_hashsize(hashsize); 358 /* prevent absurdly low value */ 359 if (hashsize < 16) 360 hashsize = 16; 361 printf("%s: WARNING: TCB hash size not a power of 2, " 362 "clipped from %d to %d.\n", __func__, oldhashsize, 363 hashsize); 364 } 365 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 366 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 367 IPI_HASHFIELDS_4TUPLE); 368 369 /* 370 * These have to be type stable for the benefit of the timers. 371 */ 372 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 373 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 374 uma_zone_set_max(V_tcpcb_zone, maxsockets); 375 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 376 377 tcp_tw_init(); 378 syncache_init(); 379 tcp_hc_init(); 380 381 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 382 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 383 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 384 385 /* Skip initialization of globals for non-default instances. */ 386 if (!IS_DEFAULT_VNET(curvnet)) 387 return; 388 389 tcp_reass_global_init(); 390 391 /* XXX virtualize those bellow? */ 392 tcp_delacktime = TCPTV_DELACK; 393 tcp_keepinit = TCPTV_KEEP_INIT; 394 tcp_keepidle = TCPTV_KEEP_IDLE; 395 tcp_keepintvl = TCPTV_KEEPINTVL; 396 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 397 tcp_msl = TCPTV_MSL; 398 tcp_rexmit_min = TCPTV_MIN; 399 if (tcp_rexmit_min < 1) 400 tcp_rexmit_min = 1; 401 tcp_rexmit_slop = TCPTV_CPU_VAR; 402 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 403 tcp_tcbhashsize = hashsize; 404 405 if (tcp_soreceive_stream) { 406 #ifdef INET 407 tcp_usrreqs.pru_soreceive = soreceive_stream; 408 #endif 409 #ifdef INET6 410 tcp6_usrreqs.pru_soreceive = soreceive_stream; 411 #endif /* INET6 */ 412 } 413 414 #ifdef INET6 415 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 416 #else /* INET6 */ 417 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 418 #endif /* INET6 */ 419 if (max_protohdr < TCP_MINPROTOHDR) 420 max_protohdr = TCP_MINPROTOHDR; 421 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 422 panic("tcp_init"); 423 #undef TCP_MINPROTOHDR 424 425 ISN_LOCK_INIT(); 426 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 427 SHUTDOWN_PRI_DEFAULT); 428 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 429 EVENTHANDLER_PRI_ANY); 430 } 431 432 #ifdef VIMAGE 433 void 434 tcp_destroy(void) 435 { 436 int error; 437 438 tcp_hc_destroy(); 439 syncache_destroy(); 440 tcp_tw_destroy(); 441 in_pcbinfo_destroy(&V_tcbinfo); 442 uma_zdestroy(V_sack_hole_zone); 443 uma_zdestroy(V_tcpcb_zone); 444 445 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 446 if (error != 0) { 447 printf("%s: WARNING: unable to deregister helper hook " 448 "type=%d, id=%d: error %d returned\n", __func__, 449 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 450 } 451 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 452 if (error != 0) { 453 printf("%s: WARNING: unable to deregister helper hook " 454 "type=%d, id=%d: error %d returned\n", __func__, 455 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 456 } 457 } 458 #endif 459 460 void 461 tcp_fini(void *xtp) 462 { 463 464 } 465 466 /* 467 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 468 * tcp_template used to store this data in mbufs, but we now recopy it out 469 * of the tcpcb each time to conserve mbufs. 470 */ 471 void 472 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 473 { 474 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 475 476 INP_WLOCK_ASSERT(inp); 477 478 #ifdef INET6 479 if ((inp->inp_vflag & INP_IPV6) != 0) { 480 struct ip6_hdr *ip6; 481 482 ip6 = (struct ip6_hdr *)ip_ptr; 483 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 484 (inp->inp_flow & IPV6_FLOWINFO_MASK); 485 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 486 (IPV6_VERSION & IPV6_VERSION_MASK); 487 ip6->ip6_nxt = IPPROTO_TCP; 488 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 489 ip6->ip6_src = inp->in6p_laddr; 490 ip6->ip6_dst = inp->in6p_faddr; 491 } 492 #endif /* INET6 */ 493 #if defined(INET6) && defined(INET) 494 else 495 #endif 496 #ifdef INET 497 { 498 struct ip *ip; 499 500 ip = (struct ip *)ip_ptr; 501 ip->ip_v = IPVERSION; 502 ip->ip_hl = 5; 503 ip->ip_tos = inp->inp_ip_tos; 504 ip->ip_len = 0; 505 ip->ip_id = 0; 506 ip->ip_off = 0; 507 ip->ip_ttl = inp->inp_ip_ttl; 508 ip->ip_sum = 0; 509 ip->ip_p = IPPROTO_TCP; 510 ip->ip_src = inp->inp_laddr; 511 ip->ip_dst = inp->inp_faddr; 512 } 513 #endif /* INET */ 514 th->th_sport = inp->inp_lport; 515 th->th_dport = inp->inp_fport; 516 th->th_seq = 0; 517 th->th_ack = 0; 518 th->th_x2 = 0; 519 th->th_off = 5; 520 th->th_flags = 0; 521 th->th_win = 0; 522 th->th_urp = 0; 523 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 524 } 525 526 /* 527 * Create template to be used to send tcp packets on a connection. 528 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 529 * use for this function is in keepalives, which use tcp_respond. 530 */ 531 struct tcptemp * 532 tcpip_maketemplate(struct inpcb *inp) 533 { 534 struct tcptemp *t; 535 536 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 537 if (t == NULL) 538 return (NULL); 539 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 540 return (t); 541 } 542 543 /* 544 * Send a single message to the TCP at address specified by 545 * the given TCP/IP header. If m == NULL, then we make a copy 546 * of the tcpiphdr at th and send directly to the addressed host. 547 * This is used to force keep alive messages out using the TCP 548 * template for a connection. If flags are given then we send 549 * a message back to the TCP which originated the segment th, 550 * and discard the mbuf containing it and any other attached mbufs. 551 * 552 * In any case the ack and sequence number of the transmitted 553 * segment are as specified by the parameters. 554 * 555 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 556 */ 557 void 558 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 559 tcp_seq ack, tcp_seq seq, int flags) 560 { 561 int tlen; 562 int win = 0; 563 struct ip *ip; 564 struct tcphdr *nth; 565 #ifdef INET6 566 struct ip6_hdr *ip6; 567 int isipv6; 568 #endif /* INET6 */ 569 int ipflags = 0; 570 struct inpcb *inp; 571 572 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 573 574 #ifdef INET6 575 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 576 ip6 = ipgen; 577 #endif /* INET6 */ 578 ip = ipgen; 579 580 if (tp != NULL) { 581 inp = tp->t_inpcb; 582 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 583 INP_WLOCK_ASSERT(inp); 584 } else 585 inp = NULL; 586 587 if (tp != NULL) { 588 if (!(flags & TH_RST)) { 589 win = sbspace(&inp->inp_socket->so_rcv); 590 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 591 win = (long)TCP_MAXWIN << tp->rcv_scale; 592 } 593 } 594 if (m == NULL) { 595 m = m_gethdr(M_NOWAIT, MT_DATA); 596 if (m == NULL) 597 return; 598 tlen = 0; 599 m->m_data += max_linkhdr; 600 #ifdef INET6 601 if (isipv6) { 602 bcopy((caddr_t)ip6, mtod(m, caddr_t), 603 sizeof(struct ip6_hdr)); 604 ip6 = mtod(m, struct ip6_hdr *); 605 nth = (struct tcphdr *)(ip6 + 1); 606 } else 607 #endif /* INET6 */ 608 { 609 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 610 ip = mtod(m, struct ip *); 611 nth = (struct tcphdr *)(ip + 1); 612 } 613 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 614 flags = TH_ACK; 615 } else { 616 /* 617 * reuse the mbuf. 618 * XXX MRT We inherrit the FIB, which is lucky. 619 */ 620 m_freem(m->m_next); 621 m->m_next = NULL; 622 m->m_data = (caddr_t)ipgen; 623 /* m_len is set later */ 624 tlen = 0; 625 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 626 #ifdef INET6 627 if (isipv6) { 628 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 629 nth = (struct tcphdr *)(ip6 + 1); 630 } else 631 #endif /* INET6 */ 632 { 633 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 634 nth = (struct tcphdr *)(ip + 1); 635 } 636 if (th != nth) { 637 /* 638 * this is usually a case when an extension header 639 * exists between the IPv6 header and the 640 * TCP header. 641 */ 642 nth->th_sport = th->th_sport; 643 nth->th_dport = th->th_dport; 644 } 645 xchg(nth->th_dport, nth->th_sport, uint16_t); 646 #undef xchg 647 } 648 #ifdef INET6 649 if (isipv6) { 650 ip6->ip6_flow = 0; 651 ip6->ip6_vfc = IPV6_VERSION; 652 ip6->ip6_nxt = IPPROTO_TCP; 653 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 654 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 655 } 656 #endif 657 #if defined(INET) && defined(INET6) 658 else 659 #endif 660 #ifdef INET 661 { 662 tlen += sizeof (struct tcpiphdr); 663 ip->ip_len = htons(tlen); 664 ip->ip_ttl = V_ip_defttl; 665 if (V_path_mtu_discovery) 666 ip->ip_off |= htons(IP_DF); 667 } 668 #endif 669 m->m_len = tlen; 670 m->m_pkthdr.len = tlen; 671 m->m_pkthdr.rcvif = NULL; 672 #ifdef MAC 673 if (inp != NULL) { 674 /* 675 * Packet is associated with a socket, so allow the 676 * label of the response to reflect the socket label. 677 */ 678 INP_WLOCK_ASSERT(inp); 679 mac_inpcb_create_mbuf(inp, m); 680 } else { 681 /* 682 * Packet is not associated with a socket, so possibly 683 * update the label in place. 684 */ 685 mac_netinet_tcp_reply(m); 686 } 687 #endif 688 nth->th_seq = htonl(seq); 689 nth->th_ack = htonl(ack); 690 nth->th_x2 = 0; 691 nth->th_off = sizeof (struct tcphdr) >> 2; 692 nth->th_flags = flags; 693 if (tp != NULL) 694 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 695 else 696 nth->th_win = htons((u_short)win); 697 nth->th_urp = 0; 698 699 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 700 #ifdef INET6 701 if (isipv6) { 702 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 703 nth->th_sum = in6_cksum_pseudo(ip6, 704 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 705 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 706 NULL, NULL); 707 } 708 #endif /* INET6 */ 709 #if defined(INET6) && defined(INET) 710 else 711 #endif 712 #ifdef INET 713 { 714 m->m_pkthdr.csum_flags = CSUM_TCP; 715 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 716 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 717 } 718 #endif /* INET */ 719 #ifdef TCPDEBUG 720 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 721 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 722 #endif 723 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *)); 724 if (flags & TH_RST) 725 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 726 tp, nth); 727 728 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 729 #ifdef INET6 730 if (isipv6) 731 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 732 #endif /* INET6 */ 733 #if defined(INET) && defined(INET6) 734 else 735 #endif 736 #ifdef INET 737 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 738 #endif 739 } 740 741 /* 742 * Create a new TCP control block, making an 743 * empty reassembly queue and hooking it to the argument 744 * protocol control block. The `inp' parameter must have 745 * come from the zone allocator set up in tcp_init(). 746 */ 747 struct tcpcb * 748 tcp_newtcpcb(struct inpcb *inp) 749 { 750 struct tcpcb_mem *tm; 751 struct tcpcb *tp; 752 #ifdef INET6 753 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 754 #endif /* INET6 */ 755 756 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 757 if (tm == NULL) 758 return (NULL); 759 tp = &tm->tcb; 760 761 /* Initialise cc_var struct for this tcpcb. */ 762 tp->ccv = &tm->ccv; 763 tp->ccv->type = IPPROTO_TCP; 764 tp->ccv->ccvc.tcp = tp; 765 766 /* 767 * Use the current system default CC algorithm. 768 */ 769 CC_LIST_RLOCK(); 770 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 771 CC_ALGO(tp) = CC_DEFAULT(); 772 CC_LIST_RUNLOCK(); 773 774 if (CC_ALGO(tp)->cb_init != NULL) 775 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 776 uma_zfree(V_tcpcb_zone, tm); 777 return (NULL); 778 } 779 780 tp->osd = &tm->osd; 781 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 782 uma_zfree(V_tcpcb_zone, tm); 783 return (NULL); 784 } 785 786 #ifdef VIMAGE 787 tp->t_vnet = inp->inp_vnet; 788 #endif 789 tp->t_timers = &tm->tt; 790 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 791 tp->t_maxseg = tp->t_maxopd = 792 #ifdef INET6 793 isipv6 ? V_tcp_v6mssdflt : 794 #endif /* INET6 */ 795 V_tcp_mssdflt; 796 797 /* Set up our timeouts. */ 798 callout_init(&tp->t_timers->tt_rexmt, 1); 799 callout_init(&tp->t_timers->tt_persist, 1); 800 callout_init(&tp->t_timers->tt_keep, 1); 801 callout_init(&tp->t_timers->tt_2msl, 1); 802 callout_init(&tp->t_timers->tt_delack, 1); 803 804 if (V_tcp_do_rfc1323) 805 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 806 if (V_tcp_do_sack) 807 tp->t_flags |= TF_SACK_PERMIT; 808 TAILQ_INIT(&tp->snd_holes); 809 /* 810 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 811 * is called. 812 */ 813 in_pcbref(inp); /* Reference for tcpcb */ 814 tp->t_inpcb = inp; 815 816 /* 817 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 818 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 819 * reasonable initial retransmit time. 820 */ 821 tp->t_srtt = TCPTV_SRTTBASE; 822 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 823 tp->t_rttmin = tcp_rexmit_min; 824 tp->t_rxtcur = TCPTV_RTOBASE; 825 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 826 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 827 tp->t_rcvtime = ticks; 828 /* 829 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 830 * because the socket may be bound to an IPv6 wildcard address, 831 * which may match an IPv4-mapped IPv6 address. 832 */ 833 inp->inp_ip_ttl = V_ip_defttl; 834 inp->inp_ppcb = tp; 835 return (tp); /* XXX */ 836 } 837 838 /* 839 * Switch the congestion control algorithm back to NewReno for any active 840 * control blocks using an algorithm which is about to go away. 841 * This ensures the CC framework can allow the unload to proceed without leaving 842 * any dangling pointers which would trigger a panic. 843 * Returning non-zero would inform the CC framework that something went wrong 844 * and it would be unsafe to allow the unload to proceed. However, there is no 845 * way for this to occur with this implementation so we always return zero. 846 */ 847 int 848 tcp_ccalgounload(struct cc_algo *unload_algo) 849 { 850 struct cc_algo *tmpalgo; 851 struct inpcb *inp; 852 struct tcpcb *tp; 853 VNET_ITERATOR_DECL(vnet_iter); 854 855 /* 856 * Check all active control blocks across all network stacks and change 857 * any that are using "unload_algo" back to NewReno. If "unload_algo" 858 * requires cleanup code to be run, call it. 859 */ 860 VNET_LIST_RLOCK(); 861 VNET_FOREACH(vnet_iter) { 862 CURVNET_SET(vnet_iter); 863 INP_INFO_WLOCK(&V_tcbinfo); 864 /* 865 * New connections already part way through being initialised 866 * with the CC algo we're removing will not race with this code 867 * because the INP_INFO_WLOCK is held during initialisation. We 868 * therefore don't enter the loop below until the connection 869 * list has stabilised. 870 */ 871 LIST_FOREACH(inp, &V_tcb, inp_list) { 872 INP_WLOCK(inp); 873 /* Important to skip tcptw structs. */ 874 if (!(inp->inp_flags & INP_TIMEWAIT) && 875 (tp = intotcpcb(inp)) != NULL) { 876 /* 877 * By holding INP_WLOCK here, we are assured 878 * that the connection is not currently 879 * executing inside the CC module's functions 880 * i.e. it is safe to make the switch back to 881 * NewReno. 882 */ 883 if (CC_ALGO(tp) == unload_algo) { 884 tmpalgo = CC_ALGO(tp); 885 /* NewReno does not require any init. */ 886 CC_ALGO(tp) = &newreno_cc_algo; 887 if (tmpalgo->cb_destroy != NULL) 888 tmpalgo->cb_destroy(tp->ccv); 889 } 890 } 891 INP_WUNLOCK(inp); 892 } 893 INP_INFO_WUNLOCK(&V_tcbinfo); 894 CURVNET_RESTORE(); 895 } 896 VNET_LIST_RUNLOCK(); 897 898 return (0); 899 } 900 901 /* 902 * Drop a TCP connection, reporting 903 * the specified error. If connection is synchronized, 904 * then send a RST to peer. 905 */ 906 struct tcpcb * 907 tcp_drop(struct tcpcb *tp, int errno) 908 { 909 struct socket *so = tp->t_inpcb->inp_socket; 910 911 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 912 INP_WLOCK_ASSERT(tp->t_inpcb); 913 914 if (TCPS_HAVERCVDSYN(tp->t_state)) { 915 tcp_state_change(tp, TCPS_CLOSED); 916 (void) tcp_output(tp); 917 TCPSTAT_INC(tcps_drops); 918 } else 919 TCPSTAT_INC(tcps_conndrops); 920 if (errno == ETIMEDOUT && tp->t_softerror) 921 errno = tp->t_softerror; 922 so->so_error = errno; 923 return (tcp_close(tp)); 924 } 925 926 void 927 tcp_discardcb(struct tcpcb *tp) 928 { 929 struct inpcb *inp = tp->t_inpcb; 930 struct socket *so = inp->inp_socket; 931 #ifdef INET6 932 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 933 #endif /* INET6 */ 934 int released; 935 936 INP_WLOCK_ASSERT(inp); 937 938 /* 939 * Make sure that all of our timers are stopped before we delete the 940 * PCB. 941 * 942 * If stopping a timer fails, we schedule a discard function in same 943 * callout, and the last discard function called will take care of 944 * deleting the tcpcb. 945 */ 946 tcp_timer_stop(tp, TT_REXMT); 947 tcp_timer_stop(tp, TT_PERSIST); 948 tcp_timer_stop(tp, TT_KEEP); 949 tcp_timer_stop(tp, TT_2MSL); 950 tcp_timer_stop(tp, TT_DELACK); 951 952 /* 953 * If we got enough samples through the srtt filter, 954 * save the rtt and rttvar in the routing entry. 955 * 'Enough' is arbitrarily defined as 4 rtt samples. 956 * 4 samples is enough for the srtt filter to converge 957 * to within enough % of the correct value; fewer samples 958 * and we could save a bogus rtt. The danger is not high 959 * as tcp quickly recovers from everything. 960 * XXX: Works very well but needs some more statistics! 961 */ 962 if (tp->t_rttupdated >= 4) { 963 struct hc_metrics_lite metrics; 964 u_long ssthresh; 965 966 bzero(&metrics, sizeof(metrics)); 967 /* 968 * Update the ssthresh always when the conditions below 969 * are satisfied. This gives us better new start value 970 * for the congestion avoidance for new connections. 971 * ssthresh is only set if packet loss occured on a session. 972 * 973 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 974 * being torn down. Ideally this code would not use 'so'. 975 */ 976 ssthresh = tp->snd_ssthresh; 977 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 978 /* 979 * convert the limit from user data bytes to 980 * packets then to packet data bytes. 981 */ 982 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 983 if (ssthresh < 2) 984 ssthresh = 2; 985 ssthresh *= (u_long)(tp->t_maxseg + 986 #ifdef INET6 987 (isipv6 ? sizeof (struct ip6_hdr) + 988 sizeof (struct tcphdr) : 989 #endif 990 sizeof (struct tcpiphdr) 991 #ifdef INET6 992 ) 993 #endif 994 ); 995 } else 996 ssthresh = 0; 997 metrics.rmx_ssthresh = ssthresh; 998 999 metrics.rmx_rtt = tp->t_srtt; 1000 metrics.rmx_rttvar = tp->t_rttvar; 1001 metrics.rmx_cwnd = tp->snd_cwnd; 1002 metrics.rmx_sendpipe = 0; 1003 metrics.rmx_recvpipe = 0; 1004 1005 tcp_hc_update(&inp->inp_inc, &metrics); 1006 } 1007 1008 /* free the reassembly queue, if any */ 1009 tcp_reass_flush(tp); 1010 1011 #ifdef TCP_OFFLOAD 1012 /* Disconnect offload device, if any. */ 1013 if (tp->t_flags & TF_TOE) 1014 tcp_offload_detach(tp); 1015 #endif 1016 1017 tcp_free_sackholes(tp); 1018 1019 /* Allow the CC algorithm to clean up after itself. */ 1020 if (CC_ALGO(tp)->cb_destroy != NULL) 1021 CC_ALGO(tp)->cb_destroy(tp->ccv); 1022 1023 khelp_destroy_osd(tp->osd); 1024 1025 CC_ALGO(tp) = NULL; 1026 inp->inp_ppcb = NULL; 1027 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1028 /* We own the last reference on tcpcb, let's free it. */ 1029 tp->t_inpcb = NULL; 1030 uma_zfree(V_tcpcb_zone, tp); 1031 released = in_pcbrele_wlocked(inp); 1032 KASSERT(!released, ("%s: inp %p should not have been released " 1033 "here", __func__, inp)); 1034 } 1035 } 1036 1037 void 1038 tcp_timer_2msl_discard(void *xtp) 1039 { 1040 1041 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1042 } 1043 1044 void 1045 tcp_timer_keep_discard(void *xtp) 1046 { 1047 1048 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1049 } 1050 1051 void 1052 tcp_timer_persist_discard(void *xtp) 1053 { 1054 1055 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1056 } 1057 1058 void 1059 tcp_timer_rexmt_discard(void *xtp) 1060 { 1061 1062 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1063 } 1064 1065 void 1066 tcp_timer_delack_discard(void *xtp) 1067 { 1068 1069 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1070 } 1071 1072 void 1073 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1074 { 1075 struct inpcb *inp; 1076 1077 CURVNET_SET(tp->t_vnet); 1078 INP_INFO_RLOCK(&V_tcbinfo); 1079 inp = tp->t_inpcb; 1080 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1081 __func__, tp)); 1082 INP_WLOCK(inp); 1083 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1084 ("%s: tcpcb has to be stopped here", __func__)); 1085 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1086 ("%s: discard callout should be running", __func__)); 1087 tp->t_timers->tt_flags &= ~timer_type; 1088 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1089 /* We own the last reference on this tcpcb, let's free it. */ 1090 tp->t_inpcb = NULL; 1091 uma_zfree(V_tcpcb_zone, tp); 1092 if (in_pcbrele_wlocked(inp)) { 1093 INP_INFO_RUNLOCK(&V_tcbinfo); 1094 CURVNET_RESTORE(); 1095 return; 1096 } 1097 } 1098 INP_WUNLOCK(inp); 1099 INP_INFO_RUNLOCK(&V_tcbinfo); 1100 CURVNET_RESTORE(); 1101 } 1102 1103 /* 1104 * Attempt to close a TCP control block, marking it as dropped, and freeing 1105 * the socket if we hold the only reference. 1106 */ 1107 struct tcpcb * 1108 tcp_close(struct tcpcb *tp) 1109 { 1110 struct inpcb *inp = tp->t_inpcb; 1111 struct socket *so; 1112 1113 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1114 INP_WLOCK_ASSERT(inp); 1115 1116 #ifdef TCP_OFFLOAD 1117 if (tp->t_state == TCPS_LISTEN) 1118 tcp_offload_listen_stop(tp); 1119 #endif 1120 in_pcbdrop(inp); 1121 TCPSTAT_INC(tcps_closed); 1122 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1123 so = inp->inp_socket; 1124 soisdisconnected(so); 1125 if (inp->inp_flags & INP_SOCKREF) { 1126 KASSERT(so->so_state & SS_PROTOREF, 1127 ("tcp_close: !SS_PROTOREF")); 1128 inp->inp_flags &= ~INP_SOCKREF; 1129 INP_WUNLOCK(inp); 1130 ACCEPT_LOCK(); 1131 SOCK_LOCK(so); 1132 so->so_state &= ~SS_PROTOREF; 1133 sofree(so); 1134 return (NULL); 1135 } 1136 return (tp); 1137 } 1138 1139 void 1140 tcp_drain(void) 1141 { 1142 VNET_ITERATOR_DECL(vnet_iter); 1143 1144 if (!do_tcpdrain) 1145 return; 1146 1147 VNET_LIST_RLOCK_NOSLEEP(); 1148 VNET_FOREACH(vnet_iter) { 1149 CURVNET_SET(vnet_iter); 1150 struct inpcb *inpb; 1151 struct tcpcb *tcpb; 1152 1153 /* 1154 * Walk the tcpbs, if existing, and flush the reassembly queue, 1155 * if there is one... 1156 * XXX: The "Net/3" implementation doesn't imply that the TCP 1157 * reassembly queue should be flushed, but in a situation 1158 * where we're really low on mbufs, this is potentially 1159 * useful. 1160 */ 1161 INP_INFO_WLOCK(&V_tcbinfo); 1162 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1163 if (inpb->inp_flags & INP_TIMEWAIT) 1164 continue; 1165 INP_WLOCK(inpb); 1166 if ((tcpb = intotcpcb(inpb)) != NULL) { 1167 tcp_reass_flush(tcpb); 1168 tcp_clean_sackreport(tcpb); 1169 } 1170 INP_WUNLOCK(inpb); 1171 } 1172 INP_INFO_WUNLOCK(&V_tcbinfo); 1173 CURVNET_RESTORE(); 1174 } 1175 VNET_LIST_RUNLOCK_NOSLEEP(); 1176 } 1177 1178 /* 1179 * Notify a tcp user of an asynchronous error; 1180 * store error as soft error, but wake up user 1181 * (for now, won't do anything until can select for soft error). 1182 * 1183 * Do not wake up user since there currently is no mechanism for 1184 * reporting soft errors (yet - a kqueue filter may be added). 1185 */ 1186 static struct inpcb * 1187 tcp_notify(struct inpcb *inp, int error) 1188 { 1189 struct tcpcb *tp; 1190 1191 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1192 INP_WLOCK_ASSERT(inp); 1193 1194 if ((inp->inp_flags & INP_TIMEWAIT) || 1195 (inp->inp_flags & INP_DROPPED)) 1196 return (inp); 1197 1198 tp = intotcpcb(inp); 1199 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1200 1201 /* 1202 * Ignore some errors if we are hooked up. 1203 * If connection hasn't completed, has retransmitted several times, 1204 * and receives a second error, give up now. This is better 1205 * than waiting a long time to establish a connection that 1206 * can never complete. 1207 */ 1208 if (tp->t_state == TCPS_ESTABLISHED && 1209 (error == EHOSTUNREACH || error == ENETUNREACH || 1210 error == EHOSTDOWN)) { 1211 return (inp); 1212 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1213 tp->t_softerror) { 1214 tp = tcp_drop(tp, error); 1215 if (tp != NULL) 1216 return (inp); 1217 else 1218 return (NULL); 1219 } else { 1220 tp->t_softerror = error; 1221 return (inp); 1222 } 1223 #if 0 1224 wakeup( &so->so_timeo); 1225 sorwakeup(so); 1226 sowwakeup(so); 1227 #endif 1228 } 1229 1230 static int 1231 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1232 { 1233 int error, i, m, n, pcb_count; 1234 struct inpcb *inp, **inp_list; 1235 inp_gen_t gencnt; 1236 struct xinpgen xig; 1237 1238 /* 1239 * The process of preparing the TCB list is too time-consuming and 1240 * resource-intensive to repeat twice on every request. 1241 */ 1242 if (req->oldptr == NULL) { 1243 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1244 n += imax(n / 8, 10); 1245 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1246 return (0); 1247 } 1248 1249 if (req->newptr != NULL) 1250 return (EPERM); 1251 1252 /* 1253 * OK, now we're committed to doing something. 1254 */ 1255 INP_LIST_RLOCK(&V_tcbinfo); 1256 gencnt = V_tcbinfo.ipi_gencnt; 1257 n = V_tcbinfo.ipi_count; 1258 INP_LIST_RUNLOCK(&V_tcbinfo); 1259 1260 m = syncache_pcbcount(); 1261 1262 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1263 + (n + m) * sizeof(struct xtcpcb)); 1264 if (error != 0) 1265 return (error); 1266 1267 xig.xig_len = sizeof xig; 1268 xig.xig_count = n + m; 1269 xig.xig_gen = gencnt; 1270 xig.xig_sogen = so_gencnt; 1271 error = SYSCTL_OUT(req, &xig, sizeof xig); 1272 if (error) 1273 return (error); 1274 1275 error = syncache_pcblist(req, m, &pcb_count); 1276 if (error) 1277 return (error); 1278 1279 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1280 if (inp_list == NULL) 1281 return (ENOMEM); 1282 1283 INP_INFO_WLOCK(&V_tcbinfo); 1284 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1285 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1286 INP_WLOCK(inp); 1287 if (inp->inp_gencnt <= gencnt) { 1288 /* 1289 * XXX: This use of cr_cansee(), introduced with 1290 * TCP state changes, is not quite right, but for 1291 * now, better than nothing. 1292 */ 1293 if (inp->inp_flags & INP_TIMEWAIT) { 1294 if (intotw(inp) != NULL) 1295 error = cr_cansee(req->td->td_ucred, 1296 intotw(inp)->tw_cred); 1297 else 1298 error = EINVAL; /* Skip this inp. */ 1299 } else 1300 error = cr_canseeinpcb(req->td->td_ucred, inp); 1301 if (error == 0) { 1302 in_pcbref(inp); 1303 inp_list[i++] = inp; 1304 } 1305 } 1306 INP_WUNLOCK(inp); 1307 } 1308 INP_INFO_WUNLOCK(&V_tcbinfo); 1309 n = i; 1310 1311 error = 0; 1312 for (i = 0; i < n; i++) { 1313 inp = inp_list[i]; 1314 INP_RLOCK(inp); 1315 if (inp->inp_gencnt <= gencnt) { 1316 struct xtcpcb xt; 1317 void *inp_ppcb; 1318 1319 bzero(&xt, sizeof(xt)); 1320 xt.xt_len = sizeof xt; 1321 /* XXX should avoid extra copy */ 1322 bcopy(inp, &xt.xt_inp, sizeof *inp); 1323 inp_ppcb = inp->inp_ppcb; 1324 if (inp_ppcb == NULL) 1325 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1326 else if (inp->inp_flags & INP_TIMEWAIT) { 1327 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1328 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1329 } else { 1330 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1331 if (xt.xt_tp.t_timers) 1332 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1333 } 1334 if (inp->inp_socket != NULL) 1335 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1336 else { 1337 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1338 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1339 } 1340 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1341 INP_RUNLOCK(inp); 1342 error = SYSCTL_OUT(req, &xt, sizeof xt); 1343 } else 1344 INP_RUNLOCK(inp); 1345 } 1346 INP_INFO_RLOCK(&V_tcbinfo); 1347 for (i = 0; i < n; i++) { 1348 inp = inp_list[i]; 1349 INP_RLOCK(inp); 1350 if (!in_pcbrele_rlocked(inp)) 1351 INP_RUNLOCK(inp); 1352 } 1353 INP_INFO_RUNLOCK(&V_tcbinfo); 1354 1355 if (!error) { 1356 /* 1357 * Give the user an updated idea of our state. 1358 * If the generation differs from what we told 1359 * her before, she knows that something happened 1360 * while we were processing this request, and it 1361 * might be necessary to retry. 1362 */ 1363 INP_LIST_RLOCK(&V_tcbinfo); 1364 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1365 xig.xig_sogen = so_gencnt; 1366 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1367 INP_LIST_RUNLOCK(&V_tcbinfo); 1368 error = SYSCTL_OUT(req, &xig, sizeof xig); 1369 } 1370 free(inp_list, M_TEMP); 1371 return (error); 1372 } 1373 1374 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1375 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1376 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1377 1378 #ifdef INET 1379 static int 1380 tcp_getcred(SYSCTL_HANDLER_ARGS) 1381 { 1382 struct xucred xuc; 1383 struct sockaddr_in addrs[2]; 1384 struct inpcb *inp; 1385 int error; 1386 1387 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1388 if (error) 1389 return (error); 1390 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1391 if (error) 1392 return (error); 1393 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1394 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1395 if (inp != NULL) { 1396 if (inp->inp_socket == NULL) 1397 error = ENOENT; 1398 if (error == 0) 1399 error = cr_canseeinpcb(req->td->td_ucred, inp); 1400 if (error == 0) 1401 cru2x(inp->inp_cred, &xuc); 1402 INP_RUNLOCK(inp); 1403 } else 1404 error = ENOENT; 1405 if (error == 0) 1406 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1407 return (error); 1408 } 1409 1410 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1411 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1412 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1413 #endif /* INET */ 1414 1415 #ifdef INET6 1416 static int 1417 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1418 { 1419 struct xucred xuc; 1420 struct sockaddr_in6 addrs[2]; 1421 struct inpcb *inp; 1422 int error; 1423 #ifdef INET 1424 int mapped = 0; 1425 #endif 1426 1427 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1428 if (error) 1429 return (error); 1430 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1431 if (error) 1432 return (error); 1433 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1434 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1435 return (error); 1436 } 1437 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1438 #ifdef INET 1439 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1440 mapped = 1; 1441 else 1442 #endif 1443 return (EINVAL); 1444 } 1445 1446 #ifdef INET 1447 if (mapped == 1) 1448 inp = in_pcblookup(&V_tcbinfo, 1449 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1450 addrs[1].sin6_port, 1451 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1452 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1453 else 1454 #endif 1455 inp = in6_pcblookup(&V_tcbinfo, 1456 &addrs[1].sin6_addr, addrs[1].sin6_port, 1457 &addrs[0].sin6_addr, addrs[0].sin6_port, 1458 INPLOOKUP_RLOCKPCB, NULL); 1459 if (inp != NULL) { 1460 if (inp->inp_socket == NULL) 1461 error = ENOENT; 1462 if (error == 0) 1463 error = cr_canseeinpcb(req->td->td_ucred, inp); 1464 if (error == 0) 1465 cru2x(inp->inp_cred, &xuc); 1466 INP_RUNLOCK(inp); 1467 } else 1468 error = ENOENT; 1469 if (error == 0) 1470 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1471 return (error); 1472 } 1473 1474 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1475 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1476 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1477 #endif /* INET6 */ 1478 1479 1480 #ifdef INET 1481 void 1482 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1483 { 1484 struct ip *ip = vip; 1485 struct tcphdr *th; 1486 struct in_addr faddr; 1487 struct inpcb *inp; 1488 struct tcpcb *tp; 1489 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1490 struct icmp *icp; 1491 struct in_conninfo inc; 1492 tcp_seq icmp_tcp_seq; 1493 int mtu; 1494 1495 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1496 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1497 return; 1498 1499 if (cmd == PRC_MSGSIZE) 1500 notify = tcp_mtudisc_notify; 1501 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1502 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1503 notify = tcp_drop_syn_sent; 1504 /* 1505 * Redirects don't need to be handled up here. 1506 */ 1507 else if (PRC_IS_REDIRECT(cmd)) 1508 return; 1509 /* 1510 * Hostdead is ugly because it goes linearly through all PCBs. 1511 * XXX: We never get this from ICMP, otherwise it makes an 1512 * excellent DoS attack on machines with many connections. 1513 */ 1514 else if (cmd == PRC_HOSTDEAD) 1515 ip = NULL; 1516 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1517 return; 1518 1519 if (ip == NULL) { 1520 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1521 return; 1522 } 1523 1524 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1525 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1526 INP_INFO_RLOCK(&V_tcbinfo); 1527 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1528 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1529 if (inp != NULL) { 1530 if (!(inp->inp_flags & INP_TIMEWAIT) && 1531 !(inp->inp_flags & INP_DROPPED) && 1532 !(inp->inp_socket == NULL)) { 1533 icmp_tcp_seq = ntohl(th->th_seq); 1534 tp = intotcpcb(inp); 1535 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1536 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1537 if (cmd == PRC_MSGSIZE) { 1538 /* 1539 * MTU discovery: 1540 * If we got a needfrag set the MTU 1541 * in the route to the suggested new 1542 * value (if given) and then notify. 1543 */ 1544 mtu = ntohs(icp->icmp_nextmtu); 1545 /* 1546 * If no alternative MTU was 1547 * proposed, try the next smaller 1548 * one. 1549 */ 1550 if (!mtu) 1551 mtu = ip_next_mtu( 1552 ntohs(ip->ip_len), 1); 1553 if (mtu < V_tcp_minmss + 1554 sizeof(struct tcpiphdr)) 1555 mtu = V_tcp_minmss + 1556 sizeof(struct tcpiphdr); 1557 /* 1558 * Only process the offered MTU if it 1559 * is smaller than the current one. 1560 */ 1561 if (mtu < tp->t_maxopd + 1562 sizeof(struct tcpiphdr)) { 1563 bzero(&inc, sizeof(inc)); 1564 inc.inc_faddr = faddr; 1565 inc.inc_fibnum = 1566 inp->inp_inc.inc_fibnum; 1567 tcp_hc_updatemtu(&inc, mtu); 1568 tcp_mtudisc(inp, mtu); 1569 } 1570 } else 1571 inp = (*notify)(inp, 1572 inetctlerrmap[cmd]); 1573 } 1574 } 1575 if (inp != NULL) 1576 INP_WUNLOCK(inp); 1577 } else { 1578 bzero(&inc, sizeof(inc)); 1579 inc.inc_fport = th->th_dport; 1580 inc.inc_lport = th->th_sport; 1581 inc.inc_faddr = faddr; 1582 inc.inc_laddr = ip->ip_src; 1583 syncache_unreach(&inc, th); 1584 } 1585 INP_INFO_RUNLOCK(&V_tcbinfo); 1586 } 1587 #endif /* INET */ 1588 1589 #ifdef INET6 1590 void 1591 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1592 { 1593 struct tcphdr th; 1594 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1595 struct ip6_hdr *ip6; 1596 struct mbuf *m; 1597 struct ip6ctlparam *ip6cp = NULL; 1598 const struct sockaddr_in6 *sa6_src = NULL; 1599 int off; 1600 struct tcp_portonly { 1601 u_int16_t th_sport; 1602 u_int16_t th_dport; 1603 } *thp; 1604 1605 if (sa->sa_family != AF_INET6 || 1606 sa->sa_len != sizeof(struct sockaddr_in6)) 1607 return; 1608 1609 if (cmd == PRC_MSGSIZE) 1610 notify = tcp_mtudisc_notify; 1611 else if (!PRC_IS_REDIRECT(cmd) && 1612 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1613 return; 1614 1615 /* if the parameter is from icmp6, decode it. */ 1616 if (d != NULL) { 1617 ip6cp = (struct ip6ctlparam *)d; 1618 m = ip6cp->ip6c_m; 1619 ip6 = ip6cp->ip6c_ip6; 1620 off = ip6cp->ip6c_off; 1621 sa6_src = ip6cp->ip6c_src; 1622 } else { 1623 m = NULL; 1624 ip6 = NULL; 1625 off = 0; /* fool gcc */ 1626 sa6_src = &sa6_any; 1627 } 1628 1629 if (ip6 != NULL) { 1630 struct in_conninfo inc; 1631 /* 1632 * XXX: We assume that when IPV6 is non NULL, 1633 * M and OFF are valid. 1634 */ 1635 1636 /* check if we can safely examine src and dst ports */ 1637 if (m->m_pkthdr.len < off + sizeof(*thp)) 1638 return; 1639 1640 bzero(&th, sizeof(th)); 1641 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1642 1643 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1644 (struct sockaddr *)ip6cp->ip6c_src, 1645 th.th_sport, cmd, NULL, notify); 1646 1647 bzero(&inc, sizeof(inc)); 1648 inc.inc_fport = th.th_dport; 1649 inc.inc_lport = th.th_sport; 1650 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1651 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1652 inc.inc_flags |= INC_ISIPV6; 1653 INP_INFO_RLOCK(&V_tcbinfo); 1654 syncache_unreach(&inc, &th); 1655 INP_INFO_RUNLOCK(&V_tcbinfo); 1656 } else 1657 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1658 0, cmd, NULL, notify); 1659 } 1660 #endif /* INET6 */ 1661 1662 1663 /* 1664 * Following is where TCP initial sequence number generation occurs. 1665 * 1666 * There are two places where we must use initial sequence numbers: 1667 * 1. In SYN-ACK packets. 1668 * 2. In SYN packets. 1669 * 1670 * All ISNs for SYN-ACK packets are generated by the syncache. See 1671 * tcp_syncache.c for details. 1672 * 1673 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1674 * depends on this property. In addition, these ISNs should be 1675 * unguessable so as to prevent connection hijacking. To satisfy 1676 * the requirements of this situation, the algorithm outlined in 1677 * RFC 1948 is used, with only small modifications. 1678 * 1679 * Implementation details: 1680 * 1681 * Time is based off the system timer, and is corrected so that it 1682 * increases by one megabyte per second. This allows for proper 1683 * recycling on high speed LANs while still leaving over an hour 1684 * before rollover. 1685 * 1686 * As reading the *exact* system time is too expensive to be done 1687 * whenever setting up a TCP connection, we increment the time 1688 * offset in two ways. First, a small random positive increment 1689 * is added to isn_offset for each connection that is set up. 1690 * Second, the function tcp_isn_tick fires once per clock tick 1691 * and increments isn_offset as necessary so that sequence numbers 1692 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1693 * random positive increments serve only to ensure that the same 1694 * exact sequence number is never sent out twice (as could otherwise 1695 * happen when a port is recycled in less than the system tick 1696 * interval.) 1697 * 1698 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1699 * between seeding of isn_secret. This is normally set to zero, 1700 * as reseeding should not be necessary. 1701 * 1702 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1703 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1704 * general, this means holding an exclusive (write) lock. 1705 */ 1706 1707 #define ISN_BYTES_PER_SECOND 1048576 1708 #define ISN_STATIC_INCREMENT 4096 1709 #define ISN_RANDOM_INCREMENT (4096 - 1) 1710 1711 static VNET_DEFINE(u_char, isn_secret[32]); 1712 static VNET_DEFINE(int, isn_last); 1713 static VNET_DEFINE(int, isn_last_reseed); 1714 static VNET_DEFINE(u_int32_t, isn_offset); 1715 static VNET_DEFINE(u_int32_t, isn_offset_old); 1716 1717 #define V_isn_secret VNET(isn_secret) 1718 #define V_isn_last VNET(isn_last) 1719 #define V_isn_last_reseed VNET(isn_last_reseed) 1720 #define V_isn_offset VNET(isn_offset) 1721 #define V_isn_offset_old VNET(isn_offset_old) 1722 1723 tcp_seq 1724 tcp_new_isn(struct tcpcb *tp) 1725 { 1726 MD5_CTX isn_ctx; 1727 u_int32_t md5_buffer[4]; 1728 tcp_seq new_isn; 1729 u_int32_t projected_offset; 1730 1731 INP_WLOCK_ASSERT(tp->t_inpcb); 1732 1733 ISN_LOCK(); 1734 /* Seed if this is the first use, reseed if requested. */ 1735 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1736 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1737 < (u_int)ticks))) { 1738 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1739 V_isn_last_reseed = ticks; 1740 } 1741 1742 /* Compute the md5 hash and return the ISN. */ 1743 MD5Init(&isn_ctx); 1744 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1745 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1746 #ifdef INET6 1747 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1748 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1749 sizeof(struct in6_addr)); 1750 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1751 sizeof(struct in6_addr)); 1752 } else 1753 #endif 1754 { 1755 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1756 sizeof(struct in_addr)); 1757 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1758 sizeof(struct in_addr)); 1759 } 1760 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1761 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1762 new_isn = (tcp_seq) md5_buffer[0]; 1763 V_isn_offset += ISN_STATIC_INCREMENT + 1764 (arc4random() & ISN_RANDOM_INCREMENT); 1765 if (ticks != V_isn_last) { 1766 projected_offset = V_isn_offset_old + 1767 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1768 if (SEQ_GT(projected_offset, V_isn_offset)) 1769 V_isn_offset = projected_offset; 1770 V_isn_offset_old = V_isn_offset; 1771 V_isn_last = ticks; 1772 } 1773 new_isn += V_isn_offset; 1774 ISN_UNLOCK(); 1775 return (new_isn); 1776 } 1777 1778 /* 1779 * When a specific ICMP unreachable message is received and the 1780 * connection state is SYN-SENT, drop the connection. This behavior 1781 * is controlled by the icmp_may_rst sysctl. 1782 */ 1783 struct inpcb * 1784 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1785 { 1786 struct tcpcb *tp; 1787 1788 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 1789 INP_WLOCK_ASSERT(inp); 1790 1791 if ((inp->inp_flags & INP_TIMEWAIT) || 1792 (inp->inp_flags & INP_DROPPED)) 1793 return (inp); 1794 1795 tp = intotcpcb(inp); 1796 if (tp->t_state != TCPS_SYN_SENT) 1797 return (inp); 1798 1799 tp = tcp_drop(tp, errno); 1800 if (tp != NULL) 1801 return (inp); 1802 else 1803 return (NULL); 1804 } 1805 1806 /* 1807 * When `need fragmentation' ICMP is received, update our idea of the MSS 1808 * based on the new value. Also nudge TCP to send something, since we 1809 * know the packet we just sent was dropped. 1810 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1811 */ 1812 static struct inpcb * 1813 tcp_mtudisc_notify(struct inpcb *inp, int error) 1814 { 1815 1816 tcp_mtudisc(inp, -1); 1817 return (inp); 1818 } 1819 1820 static void 1821 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1822 { 1823 struct tcpcb *tp; 1824 struct socket *so; 1825 1826 INP_WLOCK_ASSERT(inp); 1827 if ((inp->inp_flags & INP_TIMEWAIT) || 1828 (inp->inp_flags & INP_DROPPED)) 1829 return; 1830 1831 tp = intotcpcb(inp); 1832 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1833 1834 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1835 1836 so = inp->inp_socket; 1837 SOCKBUF_LOCK(&so->so_snd); 1838 /* If the mss is larger than the socket buffer, decrease the mss. */ 1839 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1840 tp->t_maxseg = so->so_snd.sb_hiwat; 1841 SOCKBUF_UNLOCK(&so->so_snd); 1842 1843 TCPSTAT_INC(tcps_mturesent); 1844 tp->t_rtttime = 0; 1845 tp->snd_nxt = tp->snd_una; 1846 tcp_free_sackholes(tp); 1847 tp->snd_recover = tp->snd_max; 1848 if (tp->t_flags & TF_SACK_PERMIT) 1849 EXIT_FASTRECOVERY(tp->t_flags); 1850 tcp_output(tp); 1851 } 1852 1853 #ifdef INET 1854 /* 1855 * Look-up the routing entry to the peer of this inpcb. If no route 1856 * is found and it cannot be allocated, then return 0. This routine 1857 * is called by TCP routines that access the rmx structure and by 1858 * tcp_mss_update to get the peer/interface MTU. 1859 */ 1860 u_long 1861 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 1862 { 1863 struct route sro; 1864 struct sockaddr_in *dst; 1865 struct ifnet *ifp; 1866 u_long maxmtu = 0; 1867 1868 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1869 1870 bzero(&sro, sizeof(sro)); 1871 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1872 dst = (struct sockaddr_in *)&sro.ro_dst; 1873 dst->sin_family = AF_INET; 1874 dst->sin_len = sizeof(*dst); 1875 dst->sin_addr = inc->inc_faddr; 1876 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1877 } 1878 if (sro.ro_rt != NULL) { 1879 ifp = sro.ro_rt->rt_ifp; 1880 if (sro.ro_rt->rt_mtu == 0) 1881 maxmtu = ifp->if_mtu; 1882 else 1883 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 1884 1885 /* Report additional interface capabilities. */ 1886 if (cap != NULL) { 1887 if (ifp->if_capenable & IFCAP_TSO4 && 1888 ifp->if_hwassist & CSUM_TSO) { 1889 cap->ifcap |= CSUM_TSO; 1890 cap->tsomax = ifp->if_hw_tsomax; 1891 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1892 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1893 } 1894 } 1895 RTFREE(sro.ro_rt); 1896 } 1897 return (maxmtu); 1898 } 1899 #endif /* INET */ 1900 1901 #ifdef INET6 1902 u_long 1903 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 1904 { 1905 struct route_in6 sro6; 1906 struct ifnet *ifp; 1907 u_long maxmtu = 0; 1908 1909 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1910 1911 bzero(&sro6, sizeof(sro6)); 1912 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1913 sro6.ro_dst.sin6_family = AF_INET6; 1914 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1915 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1916 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 1917 } 1918 if (sro6.ro_rt != NULL) { 1919 ifp = sro6.ro_rt->rt_ifp; 1920 if (sro6.ro_rt->rt_mtu == 0) 1921 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1922 else 1923 maxmtu = min(sro6.ro_rt->rt_mtu, 1924 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1925 1926 /* Report additional interface capabilities. */ 1927 if (cap != NULL) { 1928 if (ifp->if_capenable & IFCAP_TSO6 && 1929 ifp->if_hwassist & CSUM_TSO) { 1930 cap->ifcap |= CSUM_TSO; 1931 cap->tsomax = ifp->if_hw_tsomax; 1932 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1933 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1934 } 1935 } 1936 RTFREE(sro6.ro_rt); 1937 } 1938 1939 return (maxmtu); 1940 } 1941 #endif /* INET6 */ 1942 1943 #ifdef IPSEC 1944 /* compute ESP/AH header size for TCP, including outer IP header. */ 1945 size_t 1946 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1947 { 1948 struct inpcb *inp; 1949 struct mbuf *m; 1950 size_t hdrsiz; 1951 struct ip *ip; 1952 #ifdef INET6 1953 struct ip6_hdr *ip6; 1954 #endif 1955 struct tcphdr *th; 1956 1957 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1958 return (0); 1959 m = m_gethdr(M_NOWAIT, MT_DATA); 1960 if (!m) 1961 return (0); 1962 1963 #ifdef INET6 1964 if ((inp->inp_vflag & INP_IPV6) != 0) { 1965 ip6 = mtod(m, struct ip6_hdr *); 1966 th = (struct tcphdr *)(ip6 + 1); 1967 m->m_pkthdr.len = m->m_len = 1968 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1969 tcpip_fillheaders(inp, ip6, th); 1970 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1971 } else 1972 #endif /* INET6 */ 1973 { 1974 ip = mtod(m, struct ip *); 1975 th = (struct tcphdr *)(ip + 1); 1976 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1977 tcpip_fillheaders(inp, ip, th); 1978 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1979 } 1980 1981 m_free(m); 1982 return (hdrsiz); 1983 } 1984 #endif /* IPSEC */ 1985 1986 #ifdef TCP_SIGNATURE 1987 /* 1988 * Callback function invoked by m_apply() to digest TCP segment data 1989 * contained within an mbuf chain. 1990 */ 1991 static int 1992 tcp_signature_apply(void *fstate, void *data, u_int len) 1993 { 1994 1995 MD5Update(fstate, (u_char *)data, len); 1996 return (0); 1997 } 1998 1999 /* 2000 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2001 * search with the destination IP address, and a 'magic SPI' to be 2002 * determined by the application. This is hardcoded elsewhere to 1179 2003 */ 2004 struct secasvar * 2005 tcp_get_sav(struct mbuf *m, u_int direction) 2006 { 2007 union sockaddr_union dst; 2008 struct secasvar *sav; 2009 struct ip *ip; 2010 #ifdef INET6 2011 struct ip6_hdr *ip6; 2012 char ip6buf[INET6_ADDRSTRLEN]; 2013 #endif 2014 2015 /* Extract the destination from the IP header in the mbuf. */ 2016 bzero(&dst, sizeof(union sockaddr_union)); 2017 ip = mtod(m, struct ip *); 2018 #ifdef INET6 2019 ip6 = NULL; /* Make the compiler happy. */ 2020 #endif 2021 switch (ip->ip_v) { 2022 #ifdef INET 2023 case IPVERSION: 2024 dst.sa.sa_len = sizeof(struct sockaddr_in); 2025 dst.sa.sa_family = AF_INET; 2026 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2027 ip->ip_src : ip->ip_dst; 2028 break; 2029 #endif 2030 #ifdef INET6 2031 case (IPV6_VERSION >> 4): 2032 ip6 = mtod(m, struct ip6_hdr *); 2033 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2034 dst.sa.sa_family = AF_INET6; 2035 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2036 ip6->ip6_src : ip6->ip6_dst; 2037 break; 2038 #endif 2039 default: 2040 return (NULL); 2041 /* NOTREACHED */ 2042 break; 2043 } 2044 2045 /* Look up an SADB entry which matches the address of the peer. */ 2046 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2047 if (sav == NULL) { 2048 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2049 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2050 #ifdef INET6 2051 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2052 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2053 #endif 2054 "(unsupported)")); 2055 } 2056 2057 return (sav); 2058 } 2059 2060 /* 2061 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2062 * 2063 * Parameters: 2064 * m pointer to head of mbuf chain 2065 * len length of TCP segment data, excluding options 2066 * optlen length of TCP segment options 2067 * buf pointer to storage for computed MD5 digest 2068 * sav pointer to security assosiation 2069 * 2070 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2071 * When called from tcp_input(), we can be sure that th_sum has been 2072 * zeroed out and verified already. 2073 * 2074 * Releases reference to SADB key before return. 2075 * 2076 * Return 0 if successful, otherwise return -1. 2077 * 2078 */ 2079 int 2080 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2081 u_char *buf, struct secasvar *sav) 2082 { 2083 #ifdef INET 2084 struct ippseudo ippseudo; 2085 #endif 2086 MD5_CTX ctx; 2087 int doff; 2088 struct ip *ip; 2089 #ifdef INET 2090 struct ipovly *ipovly; 2091 #endif 2092 struct tcphdr *th; 2093 #ifdef INET6 2094 struct ip6_hdr *ip6; 2095 struct in6_addr in6; 2096 uint32_t plen; 2097 uint16_t nhdr; 2098 #endif 2099 u_short savecsum; 2100 2101 KASSERT(m != NULL, ("NULL mbuf chain")); 2102 KASSERT(buf != NULL, ("NULL signature pointer")); 2103 2104 /* Extract the destination from the IP header in the mbuf. */ 2105 ip = mtod(m, struct ip *); 2106 #ifdef INET6 2107 ip6 = NULL; /* Make the compiler happy. */ 2108 #endif 2109 2110 MD5Init(&ctx); 2111 /* 2112 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2113 * 2114 * XXX The ippseudo header MUST be digested in network byte order, 2115 * or else we'll fail the regression test. Assume all fields we've 2116 * been doing arithmetic on have been in host byte order. 2117 * XXX One cannot depend on ipovly->ih_len here. When called from 2118 * tcp_output(), the underlying ip_len member has not yet been set. 2119 */ 2120 switch (ip->ip_v) { 2121 #ifdef INET 2122 case IPVERSION: 2123 ipovly = (struct ipovly *)ip; 2124 ippseudo.ippseudo_src = ipovly->ih_src; 2125 ippseudo.ippseudo_dst = ipovly->ih_dst; 2126 ippseudo.ippseudo_pad = 0; 2127 ippseudo.ippseudo_p = IPPROTO_TCP; 2128 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2129 optlen); 2130 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2131 2132 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2133 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2134 break; 2135 #endif 2136 #ifdef INET6 2137 /* 2138 * RFC 2385, 2.0 Proposal 2139 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2140 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2141 * extended next header value (to form 32 bits), and 32-bit segment 2142 * length. 2143 * Note: Upper-Layer Packet Length comes before Next Header. 2144 */ 2145 case (IPV6_VERSION >> 4): 2146 in6 = ip6->ip6_src; 2147 in6_clearscope(&in6); 2148 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2149 in6 = ip6->ip6_dst; 2150 in6_clearscope(&in6); 2151 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2152 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2153 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2154 nhdr = 0; 2155 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2156 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2157 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2158 nhdr = IPPROTO_TCP; 2159 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2160 2161 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2162 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2163 break; 2164 #endif 2165 default: 2166 KEY_FREESAV(&sav); 2167 return (-1); 2168 /* NOTREACHED */ 2169 break; 2170 } 2171 2172 2173 /* 2174 * Step 2: Update MD5 hash with TCP header, excluding options. 2175 * The TCP checksum must be set to zero. 2176 */ 2177 savecsum = th->th_sum; 2178 th->th_sum = 0; 2179 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2180 th->th_sum = savecsum; 2181 2182 /* 2183 * Step 3: Update MD5 hash with TCP segment data. 2184 * Use m_apply() to avoid an early m_pullup(). 2185 */ 2186 if (len > 0) 2187 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2188 2189 /* 2190 * Step 4: Update MD5 hash with shared secret. 2191 */ 2192 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2193 MD5Final(buf, &ctx); 2194 2195 key_sa_recordxfer(sav, m); 2196 KEY_FREESAV(&sav); 2197 return (0); 2198 } 2199 2200 /* 2201 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2202 * 2203 * Return 0 if successful, otherwise return -1. 2204 */ 2205 int 2206 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2207 u_char *buf, u_int direction) 2208 { 2209 struct secasvar *sav; 2210 2211 if ((sav = tcp_get_sav(m, direction)) == NULL) 2212 return (-1); 2213 2214 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2215 } 2216 2217 /* 2218 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2219 * 2220 * Parameters: 2221 * m pointer to head of mbuf chain 2222 * len length of TCP segment data, excluding options 2223 * optlen length of TCP segment options 2224 * buf pointer to storage for computed MD5 digest 2225 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2226 * 2227 * Return 1 if successful, otherwise return 0. 2228 */ 2229 int 2230 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2231 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2232 { 2233 char tmpdigest[TCP_SIGLEN]; 2234 2235 if (tcp_sig_checksigs == 0) 2236 return (1); 2237 if ((tcpbflag & TF_SIGNATURE) == 0) { 2238 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2239 2240 /* 2241 * If this socket is not expecting signature but 2242 * the segment contains signature just fail. 2243 */ 2244 TCPSTAT_INC(tcps_sig_err_sigopt); 2245 TCPSTAT_INC(tcps_sig_rcvbadsig); 2246 return (0); 2247 } 2248 2249 /* Signature is not expected, and not present in segment. */ 2250 return (1); 2251 } 2252 2253 /* 2254 * If this socket is expecting signature but the segment does not 2255 * contain any just fail. 2256 */ 2257 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2258 TCPSTAT_INC(tcps_sig_err_nosigopt); 2259 TCPSTAT_INC(tcps_sig_rcvbadsig); 2260 return (0); 2261 } 2262 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2263 IPSEC_DIR_INBOUND) == -1) { 2264 TCPSTAT_INC(tcps_sig_err_buildsig); 2265 TCPSTAT_INC(tcps_sig_rcvbadsig); 2266 return (0); 2267 } 2268 2269 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2270 TCPSTAT_INC(tcps_sig_rcvbadsig); 2271 return (0); 2272 } 2273 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2274 return (1); 2275 } 2276 #endif /* TCP_SIGNATURE */ 2277 2278 static int 2279 sysctl_drop(SYSCTL_HANDLER_ARGS) 2280 { 2281 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2282 struct sockaddr_storage addrs[2]; 2283 struct inpcb *inp; 2284 struct tcpcb *tp; 2285 struct tcptw *tw; 2286 struct sockaddr_in *fin, *lin; 2287 #ifdef INET6 2288 struct sockaddr_in6 *fin6, *lin6; 2289 #endif 2290 int error; 2291 2292 inp = NULL; 2293 fin = lin = NULL; 2294 #ifdef INET6 2295 fin6 = lin6 = NULL; 2296 #endif 2297 error = 0; 2298 2299 if (req->oldptr != NULL || req->oldlen != 0) 2300 return (EINVAL); 2301 if (req->newptr == NULL) 2302 return (EPERM); 2303 if (req->newlen < sizeof(addrs)) 2304 return (ENOMEM); 2305 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2306 if (error) 2307 return (error); 2308 2309 switch (addrs[0].ss_family) { 2310 #ifdef INET6 2311 case AF_INET6: 2312 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2313 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2314 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2315 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2316 return (EINVAL); 2317 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2318 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2319 return (EINVAL); 2320 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2321 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2322 fin = (struct sockaddr_in *)&addrs[0]; 2323 lin = (struct sockaddr_in *)&addrs[1]; 2324 break; 2325 } 2326 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2327 if (error) 2328 return (error); 2329 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2330 if (error) 2331 return (error); 2332 break; 2333 #endif 2334 #ifdef INET 2335 case AF_INET: 2336 fin = (struct sockaddr_in *)&addrs[0]; 2337 lin = (struct sockaddr_in *)&addrs[1]; 2338 if (fin->sin_len != sizeof(struct sockaddr_in) || 2339 lin->sin_len != sizeof(struct sockaddr_in)) 2340 return (EINVAL); 2341 break; 2342 #endif 2343 default: 2344 return (EINVAL); 2345 } 2346 INP_INFO_RLOCK(&V_tcbinfo); 2347 switch (addrs[0].ss_family) { 2348 #ifdef INET6 2349 case AF_INET6: 2350 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2351 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2352 INPLOOKUP_WLOCKPCB, NULL); 2353 break; 2354 #endif 2355 #ifdef INET 2356 case AF_INET: 2357 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2358 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2359 break; 2360 #endif 2361 } 2362 if (inp != NULL) { 2363 if (inp->inp_flags & INP_TIMEWAIT) { 2364 /* 2365 * XXXRW: There currently exists a state where an 2366 * inpcb is present, but its timewait state has been 2367 * discarded. For now, don't allow dropping of this 2368 * type of inpcb. 2369 */ 2370 tw = intotw(inp); 2371 if (tw != NULL) 2372 tcp_twclose(tw, 0); 2373 else 2374 INP_WUNLOCK(inp); 2375 } else if (!(inp->inp_flags & INP_DROPPED) && 2376 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2377 tp = intotcpcb(inp); 2378 tp = tcp_drop(tp, ECONNABORTED); 2379 if (tp != NULL) 2380 INP_WUNLOCK(inp); 2381 } else 2382 INP_WUNLOCK(inp); 2383 } else 2384 error = ESRCH; 2385 INP_INFO_RUNLOCK(&V_tcbinfo); 2386 return (error); 2387 } 2388 2389 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2390 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2391 0, sysctl_drop, "", "Drop TCP connection"); 2392 2393 /* 2394 * Generate a standardized TCP log line for use throughout the 2395 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2396 * allow use in the interrupt context. 2397 * 2398 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2399 * NB: The function may return NULL if memory allocation failed. 2400 * 2401 * Due to header inclusion and ordering limitations the struct ip 2402 * and ip6_hdr pointers have to be passed as void pointers. 2403 */ 2404 char * 2405 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2406 const void *ip6hdr) 2407 { 2408 2409 /* Is logging enabled? */ 2410 if (tcp_log_in_vain == 0) 2411 return (NULL); 2412 2413 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2414 } 2415 2416 char * 2417 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2418 const void *ip6hdr) 2419 { 2420 2421 /* Is logging enabled? */ 2422 if (tcp_log_debug == 0) 2423 return (NULL); 2424 2425 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2426 } 2427 2428 static char * 2429 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2430 const void *ip6hdr) 2431 { 2432 char *s, *sp; 2433 size_t size; 2434 struct ip *ip; 2435 #ifdef INET6 2436 const struct ip6_hdr *ip6; 2437 2438 ip6 = (const struct ip6_hdr *)ip6hdr; 2439 #endif /* INET6 */ 2440 ip = (struct ip *)ip4hdr; 2441 2442 /* 2443 * The log line looks like this: 2444 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2445 */ 2446 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2447 sizeof(PRINT_TH_FLAGS) + 1 + 2448 #ifdef INET6 2449 2 * INET6_ADDRSTRLEN; 2450 #else 2451 2 * INET_ADDRSTRLEN; 2452 #endif /* INET6 */ 2453 2454 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2455 if (s == NULL) 2456 return (NULL); 2457 2458 strcat(s, "TCP: ["); 2459 sp = s + strlen(s); 2460 2461 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2462 inet_ntoa_r(inc->inc_faddr, sp); 2463 sp = s + strlen(s); 2464 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2465 sp = s + strlen(s); 2466 inet_ntoa_r(inc->inc_laddr, sp); 2467 sp = s + strlen(s); 2468 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2469 #ifdef INET6 2470 } else if (inc) { 2471 ip6_sprintf(sp, &inc->inc6_faddr); 2472 sp = s + strlen(s); 2473 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2474 sp = s + strlen(s); 2475 ip6_sprintf(sp, &inc->inc6_laddr); 2476 sp = s + strlen(s); 2477 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2478 } else if (ip6 && th) { 2479 ip6_sprintf(sp, &ip6->ip6_src); 2480 sp = s + strlen(s); 2481 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2482 sp = s + strlen(s); 2483 ip6_sprintf(sp, &ip6->ip6_dst); 2484 sp = s + strlen(s); 2485 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2486 #endif /* INET6 */ 2487 #ifdef INET 2488 } else if (ip && th) { 2489 inet_ntoa_r(ip->ip_src, sp); 2490 sp = s + strlen(s); 2491 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2492 sp = s + strlen(s); 2493 inet_ntoa_r(ip->ip_dst, sp); 2494 sp = s + strlen(s); 2495 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2496 #endif /* INET */ 2497 } else { 2498 free(s, M_TCPLOG); 2499 return (NULL); 2500 } 2501 sp = s + strlen(s); 2502 if (th) 2503 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2504 if (*(s + size - 1) != '\0') 2505 panic("%s: string too long", __func__); 2506 return (s); 2507 } 2508 2509 /* 2510 * A subroutine which makes it easy to track TCP state changes with DTrace. 2511 * This function shouldn't be called for t_state initializations that don't 2512 * correspond to actual TCP state transitions. 2513 */ 2514 void 2515 tcp_state_change(struct tcpcb *tp, int newstate) 2516 { 2517 #if defined(KDTRACE_HOOKS) 2518 int pstate = tp->t_state; 2519 #endif 2520 2521 tp->t_state = newstate; 2522 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2523 } 2524