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