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 TCPPCAP 96 #include <netinet/tcp_pcap.h> 97 #endif 98 #ifdef TCPDEBUG 99 #include <netinet/tcp_debug.h> 100 #endif 101 #ifdef INET6 102 #include <netinet6/ip6protosw.h> 103 #endif 104 #ifdef TCP_OFFLOAD 105 #include <netinet/tcp_offload.h> 106 #endif 107 108 #ifdef IPSEC 109 #include <netipsec/ipsec.h> 110 #include <netipsec/xform.h> 111 #ifdef INET6 112 #include <netipsec/ipsec6.h> 113 #endif 114 #include <netipsec/key.h> 115 #include <sys/syslog.h> 116 #endif /*IPSEC*/ 117 118 #include <machine/in_cksum.h> 119 #include <sys/md5.h> 120 121 #include <security/mac/mac_framework.h> 122 123 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 124 #ifdef INET6 125 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 126 #endif 127 128 static int 129 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 130 { 131 int error, new; 132 133 new = V_tcp_mssdflt; 134 error = sysctl_handle_int(oidp, &new, 0, req); 135 if (error == 0 && req->newptr) { 136 if (new < TCP_MINMSS) 137 error = EINVAL; 138 else 139 V_tcp_mssdflt = new; 140 } 141 return (error); 142 } 143 144 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 145 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 146 &sysctl_net_inet_tcp_mss_check, "I", 147 "Default TCP Maximum Segment Size"); 148 149 #ifdef INET6 150 static int 151 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 152 { 153 int error, new; 154 155 new = V_tcp_v6mssdflt; 156 error = sysctl_handle_int(oidp, &new, 0, req); 157 if (error == 0 && req->newptr) { 158 if (new < TCP_MINMSS) 159 error = EINVAL; 160 else 161 V_tcp_v6mssdflt = new; 162 } 163 return (error); 164 } 165 166 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 167 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 168 &sysctl_net_inet_tcp_mss_v6_check, "I", 169 "Default TCP Maximum Segment Size for IPv6"); 170 #endif /* INET6 */ 171 172 /* 173 * Minimum MSS we accept and use. This prevents DoS attacks where 174 * we are forced to a ridiculous low MSS like 20 and send hundreds 175 * of packets instead of one. The effect scales with the available 176 * bandwidth and quickly saturates the CPU and network interface 177 * with packet generation and sending. Set to zero to disable MINMSS 178 * checking. This setting prevents us from sending too small packets. 179 */ 180 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 181 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 182 &VNET_NAME(tcp_minmss), 0, 183 "Minimum TCP Maximum Segment Size"); 184 185 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 186 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 187 &VNET_NAME(tcp_do_rfc1323), 0, 188 "Enable rfc1323 (high performance TCP) extensions"); 189 190 static int tcp_log_debug = 0; 191 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 192 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 193 194 static int tcp_tcbhashsize; 195 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 196 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 197 198 static int do_tcpdrain = 1; 199 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 200 "Enable tcp_drain routine for extra help when low on mbufs"); 201 202 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 203 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 204 205 static VNET_DEFINE(int, icmp_may_rst) = 1; 206 #define V_icmp_may_rst VNET(icmp_may_rst) 207 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 208 &VNET_NAME(icmp_may_rst), 0, 209 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 210 211 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 212 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 213 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 214 &VNET_NAME(tcp_isn_reseed_interval), 0, 215 "Seconds between reseeding of ISN secret"); 216 217 static int tcp_soreceive_stream; 218 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 219 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 220 221 #ifdef TCP_SIGNATURE 222 static int tcp_sig_checksigs = 1; 223 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 224 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 225 #endif 226 227 VNET_DEFINE(uma_zone_t, sack_hole_zone); 228 #define V_sack_hole_zone VNET(sack_hole_zone) 229 230 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 231 232 static struct inpcb *tcp_notify(struct inpcb *, int); 233 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 234 static void tcp_mtudisc(struct inpcb *, int); 235 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 236 void *ip4hdr, const void *ip6hdr); 237 static void tcp_timer_discard(struct tcpcb *, uint32_t); 238 239 /* 240 * Target size of TCP PCB hash tables. Must be a power of two. 241 * 242 * Note that this can be overridden by the kernel environment 243 * variable net.inet.tcp.tcbhashsize 244 */ 245 #ifndef TCBHASHSIZE 246 #define TCBHASHSIZE 0 247 #endif 248 249 /* 250 * XXX 251 * Callouts should be moved into struct tcp directly. They are currently 252 * separate because the tcpcb structure is exported to userland for sysctl 253 * parsing purposes, which do not know about callouts. 254 */ 255 struct tcpcb_mem { 256 struct tcpcb tcb; 257 struct tcp_timer tt; 258 struct cc_var ccv; 259 struct osd osd; 260 }; 261 262 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 263 #define V_tcpcb_zone VNET(tcpcb_zone) 264 265 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 266 static struct mtx isn_mtx; 267 268 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 269 #define ISN_LOCK() mtx_lock(&isn_mtx) 270 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 271 272 /* 273 * TCP initialization. 274 */ 275 static void 276 tcp_zone_change(void *tag) 277 { 278 279 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 280 uma_zone_set_max(V_tcpcb_zone, maxsockets); 281 tcp_tw_zone_change(); 282 } 283 284 static int 285 tcp_inpcb_init(void *mem, int size, int flags) 286 { 287 struct inpcb *inp = mem; 288 289 INP_LOCK_INIT(inp, "inp", "tcpinp"); 290 return (0); 291 } 292 293 /* 294 * Take a value and get the next power of 2 that doesn't overflow. 295 * Used to size the tcp_inpcb hash buckets. 296 */ 297 static int 298 maketcp_hashsize(int size) 299 { 300 int hashsize; 301 302 /* 303 * auto tune. 304 * get the next power of 2 higher than maxsockets. 305 */ 306 hashsize = 1 << fls(size); 307 /* catch overflow, and just go one power of 2 smaller */ 308 if (hashsize < size) { 309 hashsize = 1 << (fls(size) - 1); 310 } 311 return (hashsize); 312 } 313 314 void 315 tcp_init(void) 316 { 317 const char *tcbhash_tuneable; 318 int hashsize; 319 320 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 321 322 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 323 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 324 printf("%s: WARNING: unable to register helper hook\n", __func__); 325 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 326 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 327 printf("%s: WARNING: unable to register helper hook\n", __func__); 328 329 hashsize = TCBHASHSIZE; 330 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 331 if (hashsize == 0) { 332 /* 333 * Auto tune the hash size based on maxsockets. 334 * A perfect hash would have a 1:1 mapping 335 * (hashsize = maxsockets) however it's been 336 * suggested that O(2) average is better. 337 */ 338 hashsize = maketcp_hashsize(maxsockets / 4); 339 /* 340 * Our historical default is 512, 341 * do not autotune lower than this. 342 */ 343 if (hashsize < 512) 344 hashsize = 512; 345 if (bootverbose) 346 printf("%s: %s auto tuned to %d\n", __func__, 347 tcbhash_tuneable, hashsize); 348 } 349 /* 350 * We require a hashsize to be a power of two. 351 * Previously if it was not a power of two we would just reset it 352 * back to 512, which could be a nasty surprise if you did not notice 353 * the error message. 354 * Instead what we do is clip it to the closest power of two lower 355 * than the specified hash value. 356 */ 357 if (!powerof2(hashsize)) { 358 int oldhashsize = hashsize; 359 360 hashsize = maketcp_hashsize(hashsize); 361 /* prevent absurdly low value */ 362 if (hashsize < 16) 363 hashsize = 16; 364 printf("%s: WARNING: TCB hash size not a power of 2, " 365 "clipped from %d to %d.\n", __func__, oldhashsize, 366 hashsize); 367 } 368 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 369 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 370 IPI_HASHFIELDS_4TUPLE); 371 372 /* 373 * These have to be type stable for the benefit of the timers. 374 */ 375 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 376 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 377 uma_zone_set_max(V_tcpcb_zone, maxsockets); 378 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 379 380 tcp_tw_init(); 381 syncache_init(); 382 tcp_hc_init(); 383 384 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 385 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 386 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 387 388 /* Skip initialization of globals for non-default instances. */ 389 if (!IS_DEFAULT_VNET(curvnet)) 390 return; 391 392 tcp_reass_global_init(); 393 394 /* XXX virtualize those bellow? */ 395 tcp_delacktime = TCPTV_DELACK; 396 tcp_keepinit = TCPTV_KEEP_INIT; 397 tcp_keepidle = TCPTV_KEEP_IDLE; 398 tcp_keepintvl = TCPTV_KEEPINTVL; 399 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 400 tcp_msl = TCPTV_MSL; 401 tcp_rexmit_min = TCPTV_MIN; 402 if (tcp_rexmit_min < 1) 403 tcp_rexmit_min = 1; 404 tcp_rexmit_slop = TCPTV_CPU_VAR; 405 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 406 tcp_tcbhashsize = hashsize; 407 408 if (tcp_soreceive_stream) { 409 #ifdef INET 410 tcp_usrreqs.pru_soreceive = soreceive_stream; 411 #endif 412 #ifdef INET6 413 tcp6_usrreqs.pru_soreceive = soreceive_stream; 414 #endif /* INET6 */ 415 } 416 417 #ifdef INET6 418 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 419 #else /* INET6 */ 420 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 421 #endif /* INET6 */ 422 if (max_protohdr < TCP_MINPROTOHDR) 423 max_protohdr = TCP_MINPROTOHDR; 424 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 425 panic("tcp_init"); 426 #undef TCP_MINPROTOHDR 427 428 ISN_LOCK_INIT(); 429 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 430 SHUTDOWN_PRI_DEFAULT); 431 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 432 EVENTHANDLER_PRI_ANY); 433 #ifdef TCPPCAP 434 tcp_pcap_init(); 435 #endif 436 } 437 438 #ifdef VIMAGE 439 void 440 tcp_destroy(void) 441 { 442 int error; 443 444 tcp_hc_destroy(); 445 syncache_destroy(); 446 tcp_tw_destroy(); 447 in_pcbinfo_destroy(&V_tcbinfo); 448 uma_zdestroy(V_sack_hole_zone); 449 uma_zdestroy(V_tcpcb_zone); 450 451 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 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_IN, error); 456 } 457 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 458 if (error != 0) { 459 printf("%s: WARNING: unable to deregister helper hook " 460 "type=%d, id=%d: error %d returned\n", __func__, 461 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 462 } 463 } 464 #endif 465 466 void 467 tcp_fini(void *xtp) 468 { 469 470 } 471 472 /* 473 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 474 * tcp_template used to store this data in mbufs, but we now recopy it out 475 * of the tcpcb each time to conserve mbufs. 476 */ 477 void 478 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 479 { 480 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 481 482 INP_WLOCK_ASSERT(inp); 483 484 #ifdef INET6 485 if ((inp->inp_vflag & INP_IPV6) != 0) { 486 struct ip6_hdr *ip6; 487 488 ip6 = (struct ip6_hdr *)ip_ptr; 489 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 490 (inp->inp_flow & IPV6_FLOWINFO_MASK); 491 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 492 (IPV6_VERSION & IPV6_VERSION_MASK); 493 ip6->ip6_nxt = IPPROTO_TCP; 494 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 495 ip6->ip6_src = inp->in6p_laddr; 496 ip6->ip6_dst = inp->in6p_faddr; 497 } 498 #endif /* INET6 */ 499 #if defined(INET6) && defined(INET) 500 else 501 #endif 502 #ifdef INET 503 { 504 struct ip *ip; 505 506 ip = (struct ip *)ip_ptr; 507 ip->ip_v = IPVERSION; 508 ip->ip_hl = 5; 509 ip->ip_tos = inp->inp_ip_tos; 510 ip->ip_len = 0; 511 ip->ip_id = 0; 512 ip->ip_off = 0; 513 ip->ip_ttl = inp->inp_ip_ttl; 514 ip->ip_sum = 0; 515 ip->ip_p = IPPROTO_TCP; 516 ip->ip_src = inp->inp_laddr; 517 ip->ip_dst = inp->inp_faddr; 518 } 519 #endif /* INET */ 520 th->th_sport = inp->inp_lport; 521 th->th_dport = inp->inp_fport; 522 th->th_seq = 0; 523 th->th_ack = 0; 524 th->th_x2 = 0; 525 th->th_off = 5; 526 th->th_flags = 0; 527 th->th_win = 0; 528 th->th_urp = 0; 529 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 530 } 531 532 /* 533 * Create template to be used to send tcp packets on a connection. 534 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 535 * use for this function is in keepalives, which use tcp_respond. 536 */ 537 struct tcptemp * 538 tcpip_maketemplate(struct inpcb *inp) 539 { 540 struct tcptemp *t; 541 542 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 543 if (t == NULL) 544 return (NULL); 545 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 546 return (t); 547 } 548 549 /* 550 * Send a single message to the TCP at address specified by 551 * the given TCP/IP header. If m == NULL, then we make a copy 552 * of the tcpiphdr at th and send directly to the addressed host. 553 * This is used to force keep alive messages out using the TCP 554 * template for a connection. If flags are given then we send 555 * a message back to the TCP which originated the segment th, 556 * and discard the mbuf containing it and any other attached mbufs. 557 * 558 * In any case the ack and sequence number of the transmitted 559 * segment are as specified by the parameters. 560 * 561 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 562 */ 563 void 564 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 565 tcp_seq ack, tcp_seq seq, int flags) 566 { 567 int tlen; 568 int win = 0; 569 struct ip *ip; 570 struct tcphdr *nth; 571 #ifdef INET6 572 struct ip6_hdr *ip6; 573 int isipv6; 574 #endif /* INET6 */ 575 int ipflags = 0; 576 struct inpcb *inp; 577 578 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 579 580 #ifdef INET6 581 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 582 ip6 = ipgen; 583 #endif /* INET6 */ 584 ip = ipgen; 585 586 if (tp != NULL) { 587 inp = tp->t_inpcb; 588 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 589 INP_WLOCK_ASSERT(inp); 590 } else 591 inp = NULL; 592 593 if (tp != NULL) { 594 if (!(flags & TH_RST)) { 595 win = sbspace(&inp->inp_socket->so_rcv); 596 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 597 win = (long)TCP_MAXWIN << tp->rcv_scale; 598 } 599 } 600 if (m == NULL) { 601 m = m_gethdr(M_NOWAIT, MT_DATA); 602 if (m == NULL) 603 return; 604 tlen = 0; 605 m->m_data += max_linkhdr; 606 #ifdef INET6 607 if (isipv6) { 608 bcopy((caddr_t)ip6, mtod(m, caddr_t), 609 sizeof(struct ip6_hdr)); 610 ip6 = mtod(m, struct ip6_hdr *); 611 nth = (struct tcphdr *)(ip6 + 1); 612 } else 613 #endif /* INET6 */ 614 { 615 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 616 ip = mtod(m, struct ip *); 617 nth = (struct tcphdr *)(ip + 1); 618 } 619 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 620 flags = TH_ACK; 621 } else { 622 /* 623 * reuse the mbuf. 624 * XXX MRT We inherrit the FIB, which is lucky. 625 */ 626 m_freem(m->m_next); 627 m->m_next = NULL; 628 m->m_data = (caddr_t)ipgen; 629 /* m_len is set later */ 630 tlen = 0; 631 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 632 #ifdef INET6 633 if (isipv6) { 634 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 635 nth = (struct tcphdr *)(ip6 + 1); 636 } else 637 #endif /* INET6 */ 638 { 639 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 640 nth = (struct tcphdr *)(ip + 1); 641 } 642 if (th != nth) { 643 /* 644 * this is usually a case when an extension header 645 * exists between the IPv6 header and the 646 * TCP header. 647 */ 648 nth->th_sport = th->th_sport; 649 nth->th_dport = th->th_dport; 650 } 651 xchg(nth->th_dport, nth->th_sport, uint16_t); 652 #undef xchg 653 } 654 #ifdef INET6 655 if (isipv6) { 656 ip6->ip6_flow = 0; 657 ip6->ip6_vfc = IPV6_VERSION; 658 ip6->ip6_nxt = IPPROTO_TCP; 659 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 660 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 661 } 662 #endif 663 #if defined(INET) && defined(INET6) 664 else 665 #endif 666 #ifdef INET 667 { 668 tlen += sizeof (struct tcpiphdr); 669 ip->ip_len = htons(tlen); 670 ip->ip_ttl = V_ip_defttl; 671 if (V_path_mtu_discovery) 672 ip->ip_off |= htons(IP_DF); 673 } 674 #endif 675 m->m_len = tlen; 676 m->m_pkthdr.len = tlen; 677 m->m_pkthdr.rcvif = NULL; 678 #ifdef MAC 679 if (inp != NULL) { 680 /* 681 * Packet is associated with a socket, so allow the 682 * label of the response to reflect the socket label. 683 */ 684 INP_WLOCK_ASSERT(inp); 685 mac_inpcb_create_mbuf(inp, m); 686 } else { 687 /* 688 * Packet is not associated with a socket, so possibly 689 * update the label in place. 690 */ 691 mac_netinet_tcp_reply(m); 692 } 693 #endif 694 nth->th_seq = htonl(seq); 695 nth->th_ack = htonl(ack); 696 nth->th_x2 = 0; 697 nth->th_off = sizeof (struct tcphdr) >> 2; 698 nth->th_flags = flags; 699 if (tp != NULL) 700 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 701 else 702 nth->th_win = htons((u_short)win); 703 nth->th_urp = 0; 704 705 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 706 #ifdef INET6 707 if (isipv6) { 708 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 709 nth->th_sum = in6_cksum_pseudo(ip6, 710 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 711 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 712 NULL, NULL); 713 } 714 #endif /* INET6 */ 715 #if defined(INET6) && defined(INET) 716 else 717 #endif 718 #ifdef INET 719 { 720 m->m_pkthdr.csum_flags = CSUM_TCP; 721 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 722 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 723 } 724 #endif /* INET */ 725 #ifdef TCPDEBUG 726 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 727 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 728 #endif 729 TCP_PROBE3(debug__input, tp, th, mtod(m, const char *)); 730 if (flags & TH_RST) 731 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *), 732 tp, nth); 733 734 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth); 735 #ifdef INET6 736 if (isipv6) 737 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 738 #endif /* INET6 */ 739 #if defined(INET) && defined(INET6) 740 else 741 #endif 742 #ifdef INET 743 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 744 #endif 745 } 746 747 /* 748 * Create a new TCP control block, making an 749 * empty reassembly queue and hooking it to the argument 750 * protocol control block. The `inp' parameter must have 751 * come from the zone allocator set up in tcp_init(). 752 */ 753 struct tcpcb * 754 tcp_newtcpcb(struct inpcb *inp) 755 { 756 struct tcpcb_mem *tm; 757 struct tcpcb *tp; 758 #ifdef INET6 759 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 760 #endif /* INET6 */ 761 762 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 763 if (tm == NULL) 764 return (NULL); 765 tp = &tm->tcb; 766 767 /* Initialise cc_var struct for this tcpcb. */ 768 tp->ccv = &tm->ccv; 769 tp->ccv->type = IPPROTO_TCP; 770 tp->ccv->ccvc.tcp = tp; 771 772 /* 773 * Use the current system default CC algorithm. 774 */ 775 CC_LIST_RLOCK(); 776 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 777 CC_ALGO(tp) = CC_DEFAULT(); 778 CC_LIST_RUNLOCK(); 779 780 if (CC_ALGO(tp)->cb_init != NULL) 781 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 782 uma_zfree(V_tcpcb_zone, tm); 783 return (NULL); 784 } 785 786 tp->osd = &tm->osd; 787 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 788 uma_zfree(V_tcpcb_zone, tm); 789 return (NULL); 790 } 791 792 #ifdef VIMAGE 793 tp->t_vnet = inp->inp_vnet; 794 #endif 795 tp->t_timers = &tm->tt; 796 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 797 tp->t_maxseg = tp->t_maxopd = 798 #ifdef INET6 799 isipv6 ? V_tcp_v6mssdflt : 800 #endif /* INET6 */ 801 V_tcp_mssdflt; 802 803 /* Set up our timeouts. */ 804 callout_init(&tp->t_timers->tt_rexmt, 1); 805 callout_init(&tp->t_timers->tt_persist, 1); 806 callout_init(&tp->t_timers->tt_keep, 1); 807 callout_init(&tp->t_timers->tt_2msl, 1); 808 callout_init(&tp->t_timers->tt_delack, 1); 809 810 if (V_tcp_do_rfc1323) 811 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 812 if (V_tcp_do_sack) 813 tp->t_flags |= TF_SACK_PERMIT; 814 TAILQ_INIT(&tp->snd_holes); 815 /* 816 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 817 * is called. 818 */ 819 in_pcbref(inp); /* Reference for tcpcb */ 820 tp->t_inpcb = inp; 821 822 /* 823 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 824 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 825 * reasonable initial retransmit time. 826 */ 827 tp->t_srtt = TCPTV_SRTTBASE; 828 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 829 tp->t_rttmin = tcp_rexmit_min; 830 tp->t_rxtcur = TCPTV_RTOBASE; 831 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 832 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 833 tp->t_rcvtime = ticks; 834 /* 835 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 836 * because the socket may be bound to an IPv6 wildcard address, 837 * which may match an IPv4-mapped IPv6 address. 838 */ 839 inp->inp_ip_ttl = V_ip_defttl; 840 inp->inp_ppcb = tp; 841 #ifdef TCPPCAP 842 /* 843 * Init the TCP PCAP queues. 844 */ 845 tcp_pcap_tcpcb_init(tp); 846 #endif 847 return (tp); /* XXX */ 848 } 849 850 /* 851 * Switch the congestion control algorithm back to NewReno for any active 852 * control blocks using an algorithm which is about to go away. 853 * This ensures the CC framework can allow the unload to proceed without leaving 854 * any dangling pointers which would trigger a panic. 855 * Returning non-zero would inform the CC framework that something went wrong 856 * and it would be unsafe to allow the unload to proceed. However, there is no 857 * way for this to occur with this implementation so we always return zero. 858 */ 859 int 860 tcp_ccalgounload(struct cc_algo *unload_algo) 861 { 862 struct cc_algo *tmpalgo; 863 struct inpcb *inp; 864 struct tcpcb *tp; 865 VNET_ITERATOR_DECL(vnet_iter); 866 867 /* 868 * Check all active control blocks across all network stacks and change 869 * any that are using "unload_algo" back to NewReno. If "unload_algo" 870 * requires cleanup code to be run, call it. 871 */ 872 VNET_LIST_RLOCK(); 873 VNET_FOREACH(vnet_iter) { 874 CURVNET_SET(vnet_iter); 875 INP_INFO_WLOCK(&V_tcbinfo); 876 /* 877 * New connections already part way through being initialised 878 * with the CC algo we're removing will not race with this code 879 * because the INP_INFO_WLOCK is held during initialisation. We 880 * therefore don't enter the loop below until the connection 881 * list has stabilised. 882 */ 883 LIST_FOREACH(inp, &V_tcb, inp_list) { 884 INP_WLOCK(inp); 885 /* Important to skip tcptw structs. */ 886 if (!(inp->inp_flags & INP_TIMEWAIT) && 887 (tp = intotcpcb(inp)) != NULL) { 888 /* 889 * By holding INP_WLOCK here, we are assured 890 * that the connection is not currently 891 * executing inside the CC module's functions 892 * i.e. it is safe to make the switch back to 893 * NewReno. 894 */ 895 if (CC_ALGO(tp) == unload_algo) { 896 tmpalgo = CC_ALGO(tp); 897 /* NewReno does not require any init. */ 898 CC_ALGO(tp) = &newreno_cc_algo; 899 if (tmpalgo->cb_destroy != NULL) 900 tmpalgo->cb_destroy(tp->ccv); 901 } 902 } 903 INP_WUNLOCK(inp); 904 } 905 INP_INFO_WUNLOCK(&V_tcbinfo); 906 CURVNET_RESTORE(); 907 } 908 VNET_LIST_RUNLOCK(); 909 910 return (0); 911 } 912 913 /* 914 * Drop a TCP connection, reporting 915 * the specified error. If connection is synchronized, 916 * then send a RST to peer. 917 */ 918 struct tcpcb * 919 tcp_drop(struct tcpcb *tp, int errno) 920 { 921 struct socket *so = tp->t_inpcb->inp_socket; 922 923 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 924 INP_WLOCK_ASSERT(tp->t_inpcb); 925 926 if (TCPS_HAVERCVDSYN(tp->t_state)) { 927 tcp_state_change(tp, TCPS_CLOSED); 928 (void) tcp_output(tp); 929 TCPSTAT_INC(tcps_drops); 930 } else 931 TCPSTAT_INC(tcps_conndrops); 932 if (errno == ETIMEDOUT && tp->t_softerror) 933 errno = tp->t_softerror; 934 so->so_error = errno; 935 return (tcp_close(tp)); 936 } 937 938 void 939 tcp_discardcb(struct tcpcb *tp) 940 { 941 struct inpcb *inp = tp->t_inpcb; 942 struct socket *so = inp->inp_socket; 943 #ifdef INET6 944 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 945 #endif /* INET6 */ 946 int released; 947 948 INP_WLOCK_ASSERT(inp); 949 950 /* 951 * Make sure that all of our timers are stopped before we delete the 952 * PCB. 953 * 954 * If stopping a timer fails, we schedule a discard function in same 955 * callout, and the last discard function called will take care of 956 * deleting the tcpcb. 957 */ 958 tcp_timer_stop(tp, TT_REXMT); 959 tcp_timer_stop(tp, TT_PERSIST); 960 tcp_timer_stop(tp, TT_KEEP); 961 tcp_timer_stop(tp, TT_2MSL); 962 tcp_timer_stop(tp, TT_DELACK); 963 964 /* 965 * If we got enough samples through the srtt filter, 966 * save the rtt and rttvar in the routing entry. 967 * 'Enough' is arbitrarily defined as 4 rtt samples. 968 * 4 samples is enough for the srtt filter to converge 969 * to within enough % of the correct value; fewer samples 970 * and we could save a bogus rtt. The danger is not high 971 * as tcp quickly recovers from everything. 972 * XXX: Works very well but needs some more statistics! 973 */ 974 if (tp->t_rttupdated >= 4) { 975 struct hc_metrics_lite metrics; 976 u_long ssthresh; 977 978 bzero(&metrics, sizeof(metrics)); 979 /* 980 * Update the ssthresh always when the conditions below 981 * are satisfied. This gives us better new start value 982 * for the congestion avoidance for new connections. 983 * ssthresh is only set if packet loss occured on a session. 984 * 985 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 986 * being torn down. Ideally this code would not use 'so'. 987 */ 988 ssthresh = tp->snd_ssthresh; 989 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 990 /* 991 * convert the limit from user data bytes to 992 * packets then to packet data bytes. 993 */ 994 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 995 if (ssthresh < 2) 996 ssthresh = 2; 997 ssthresh *= (u_long)(tp->t_maxseg + 998 #ifdef INET6 999 (isipv6 ? sizeof (struct ip6_hdr) + 1000 sizeof (struct tcphdr) : 1001 #endif 1002 sizeof (struct tcpiphdr) 1003 #ifdef INET6 1004 ) 1005 #endif 1006 ); 1007 } else 1008 ssthresh = 0; 1009 metrics.rmx_ssthresh = ssthresh; 1010 1011 metrics.rmx_rtt = tp->t_srtt; 1012 metrics.rmx_rttvar = tp->t_rttvar; 1013 metrics.rmx_cwnd = tp->snd_cwnd; 1014 metrics.rmx_sendpipe = 0; 1015 metrics.rmx_recvpipe = 0; 1016 1017 tcp_hc_update(&inp->inp_inc, &metrics); 1018 } 1019 1020 /* free the reassembly queue, if any */ 1021 tcp_reass_flush(tp); 1022 1023 #ifdef TCP_OFFLOAD 1024 /* Disconnect offload device, if any. */ 1025 if (tp->t_flags & TF_TOE) 1026 tcp_offload_detach(tp); 1027 #endif 1028 1029 tcp_free_sackholes(tp); 1030 1031 #ifdef TCPPCAP 1032 /* Free the TCP PCAP queues. */ 1033 tcp_pcap_drain(&(tp->t_inpkts)); 1034 tcp_pcap_drain(&(tp->t_outpkts)); 1035 #endif 1036 1037 /* Allow the CC algorithm to clean up after itself. */ 1038 if (CC_ALGO(tp)->cb_destroy != NULL) 1039 CC_ALGO(tp)->cb_destroy(tp->ccv); 1040 1041 khelp_destroy_osd(tp->osd); 1042 1043 CC_ALGO(tp) = NULL; 1044 inp->inp_ppcb = NULL; 1045 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1046 /* We own the last reference on tcpcb, let's free it. */ 1047 tp->t_inpcb = NULL; 1048 uma_zfree(V_tcpcb_zone, tp); 1049 released = in_pcbrele_wlocked(inp); 1050 KASSERT(!released, ("%s: inp %p should not have been released " 1051 "here", __func__, inp)); 1052 } 1053 } 1054 1055 void 1056 tcp_timer_2msl_discard(void *xtp) 1057 { 1058 1059 tcp_timer_discard((struct tcpcb *)xtp, TT_2MSL); 1060 } 1061 1062 void 1063 tcp_timer_keep_discard(void *xtp) 1064 { 1065 1066 tcp_timer_discard((struct tcpcb *)xtp, TT_KEEP); 1067 } 1068 1069 void 1070 tcp_timer_persist_discard(void *xtp) 1071 { 1072 1073 tcp_timer_discard((struct tcpcb *)xtp, TT_PERSIST); 1074 } 1075 1076 void 1077 tcp_timer_rexmt_discard(void *xtp) 1078 { 1079 1080 tcp_timer_discard((struct tcpcb *)xtp, TT_REXMT); 1081 } 1082 1083 void 1084 tcp_timer_delack_discard(void *xtp) 1085 { 1086 1087 tcp_timer_discard((struct tcpcb *)xtp, TT_DELACK); 1088 } 1089 1090 void 1091 tcp_timer_discard(struct tcpcb *tp, uint32_t timer_type) 1092 { 1093 struct inpcb *inp; 1094 1095 CURVNET_SET(tp->t_vnet); 1096 INP_INFO_RLOCK(&V_tcbinfo); 1097 inp = tp->t_inpcb; 1098 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1099 __func__, tp)); 1100 INP_WLOCK(inp); 1101 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1102 ("%s: tcpcb has to be stopped here", __func__)); 1103 KASSERT((tp->t_timers->tt_flags & timer_type) != 0, 1104 ("%s: discard callout should be running", __func__)); 1105 tp->t_timers->tt_flags &= ~timer_type; 1106 if ((tp->t_timers->tt_flags & TT_MASK) == 0) { 1107 /* We own the last reference on this tcpcb, let's free it. */ 1108 tp->t_inpcb = NULL; 1109 uma_zfree(V_tcpcb_zone, tp); 1110 if (in_pcbrele_wlocked(inp)) { 1111 INP_INFO_RUNLOCK(&V_tcbinfo); 1112 CURVNET_RESTORE(); 1113 return; 1114 } 1115 } 1116 INP_WUNLOCK(inp); 1117 INP_INFO_RUNLOCK(&V_tcbinfo); 1118 CURVNET_RESTORE(); 1119 } 1120 1121 /* 1122 * Attempt to close a TCP control block, marking it as dropped, and freeing 1123 * the socket if we hold the only reference. 1124 */ 1125 struct tcpcb * 1126 tcp_close(struct tcpcb *tp) 1127 { 1128 struct inpcb *inp = tp->t_inpcb; 1129 struct socket *so; 1130 1131 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1132 INP_WLOCK_ASSERT(inp); 1133 1134 #ifdef TCP_OFFLOAD 1135 if (tp->t_state == TCPS_LISTEN) 1136 tcp_offload_listen_stop(tp); 1137 #endif 1138 in_pcbdrop(inp); 1139 TCPSTAT_INC(tcps_closed); 1140 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1141 so = inp->inp_socket; 1142 soisdisconnected(so); 1143 if (inp->inp_flags & INP_SOCKREF) { 1144 KASSERT(so->so_state & SS_PROTOREF, 1145 ("tcp_close: !SS_PROTOREF")); 1146 inp->inp_flags &= ~INP_SOCKREF; 1147 INP_WUNLOCK(inp); 1148 ACCEPT_LOCK(); 1149 SOCK_LOCK(so); 1150 so->so_state &= ~SS_PROTOREF; 1151 sofree(so); 1152 return (NULL); 1153 } 1154 return (tp); 1155 } 1156 1157 void 1158 tcp_drain(void) 1159 { 1160 VNET_ITERATOR_DECL(vnet_iter); 1161 1162 if (!do_tcpdrain) 1163 return; 1164 1165 VNET_LIST_RLOCK_NOSLEEP(); 1166 VNET_FOREACH(vnet_iter) { 1167 CURVNET_SET(vnet_iter); 1168 struct inpcb *inpb; 1169 struct tcpcb *tcpb; 1170 1171 /* 1172 * Walk the tcpbs, if existing, and flush the reassembly queue, 1173 * if there is one... 1174 * XXX: The "Net/3" implementation doesn't imply that the TCP 1175 * reassembly queue should be flushed, but in a situation 1176 * where we're really low on mbufs, this is potentially 1177 * useful. 1178 */ 1179 INP_INFO_WLOCK(&V_tcbinfo); 1180 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1181 if (inpb->inp_flags & INP_TIMEWAIT) 1182 continue; 1183 INP_WLOCK(inpb); 1184 if ((tcpb = intotcpcb(inpb)) != NULL) { 1185 tcp_reass_flush(tcpb); 1186 tcp_clean_sackreport(tcpb); 1187 } 1188 INP_WUNLOCK(inpb); 1189 } 1190 INP_INFO_WUNLOCK(&V_tcbinfo); 1191 CURVNET_RESTORE(); 1192 } 1193 VNET_LIST_RUNLOCK_NOSLEEP(); 1194 } 1195 1196 /* 1197 * Notify a tcp user of an asynchronous error; 1198 * store error as soft error, but wake up user 1199 * (for now, won't do anything until can select for soft error). 1200 * 1201 * Do not wake up user since there currently is no mechanism for 1202 * reporting soft errors (yet - a kqueue filter may be added). 1203 */ 1204 static struct inpcb * 1205 tcp_notify(struct inpcb *inp, int error) 1206 { 1207 struct tcpcb *tp; 1208 1209 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1210 INP_WLOCK_ASSERT(inp); 1211 1212 if ((inp->inp_flags & INP_TIMEWAIT) || 1213 (inp->inp_flags & INP_DROPPED)) 1214 return (inp); 1215 1216 tp = intotcpcb(inp); 1217 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1218 1219 /* 1220 * Ignore some errors if we are hooked up. 1221 * If connection hasn't completed, has retransmitted several times, 1222 * and receives a second error, give up now. This is better 1223 * than waiting a long time to establish a connection that 1224 * can never complete. 1225 */ 1226 if (tp->t_state == TCPS_ESTABLISHED && 1227 (error == EHOSTUNREACH || error == ENETUNREACH || 1228 error == EHOSTDOWN)) { 1229 return (inp); 1230 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1231 tp->t_softerror) { 1232 tp = tcp_drop(tp, error); 1233 if (tp != NULL) 1234 return (inp); 1235 else 1236 return (NULL); 1237 } else { 1238 tp->t_softerror = error; 1239 return (inp); 1240 } 1241 #if 0 1242 wakeup( &so->so_timeo); 1243 sorwakeup(so); 1244 sowwakeup(so); 1245 #endif 1246 } 1247 1248 static int 1249 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1250 { 1251 int error, i, m, n, pcb_count; 1252 struct inpcb *inp, **inp_list; 1253 inp_gen_t gencnt; 1254 struct xinpgen xig; 1255 1256 /* 1257 * The process of preparing the TCB list is too time-consuming and 1258 * resource-intensive to repeat twice on every request. 1259 */ 1260 if (req->oldptr == NULL) { 1261 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1262 n += imax(n / 8, 10); 1263 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1264 return (0); 1265 } 1266 1267 if (req->newptr != NULL) 1268 return (EPERM); 1269 1270 /* 1271 * OK, now we're committed to doing something. 1272 */ 1273 INP_LIST_RLOCK(&V_tcbinfo); 1274 gencnt = V_tcbinfo.ipi_gencnt; 1275 n = V_tcbinfo.ipi_count; 1276 INP_LIST_RUNLOCK(&V_tcbinfo); 1277 1278 m = syncache_pcbcount(); 1279 1280 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1281 + (n + m) * sizeof(struct xtcpcb)); 1282 if (error != 0) 1283 return (error); 1284 1285 xig.xig_len = sizeof xig; 1286 xig.xig_count = n + m; 1287 xig.xig_gen = gencnt; 1288 xig.xig_sogen = so_gencnt; 1289 error = SYSCTL_OUT(req, &xig, sizeof xig); 1290 if (error) 1291 return (error); 1292 1293 error = syncache_pcblist(req, m, &pcb_count); 1294 if (error) 1295 return (error); 1296 1297 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1298 if (inp_list == NULL) 1299 return (ENOMEM); 1300 1301 INP_INFO_WLOCK(&V_tcbinfo); 1302 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1303 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1304 INP_WLOCK(inp); 1305 if (inp->inp_gencnt <= gencnt) { 1306 /* 1307 * XXX: This use of cr_cansee(), introduced with 1308 * TCP state changes, is not quite right, but for 1309 * now, better than nothing. 1310 */ 1311 if (inp->inp_flags & INP_TIMEWAIT) { 1312 if (intotw(inp) != NULL) 1313 error = cr_cansee(req->td->td_ucred, 1314 intotw(inp)->tw_cred); 1315 else 1316 error = EINVAL; /* Skip this inp. */ 1317 } else 1318 error = cr_canseeinpcb(req->td->td_ucred, inp); 1319 if (error == 0) { 1320 in_pcbref(inp); 1321 inp_list[i++] = inp; 1322 } 1323 } 1324 INP_WUNLOCK(inp); 1325 } 1326 INP_INFO_WUNLOCK(&V_tcbinfo); 1327 n = i; 1328 1329 error = 0; 1330 for (i = 0; i < n; i++) { 1331 inp = inp_list[i]; 1332 INP_RLOCK(inp); 1333 if (inp->inp_gencnt <= gencnt) { 1334 struct xtcpcb xt; 1335 void *inp_ppcb; 1336 1337 bzero(&xt, sizeof(xt)); 1338 xt.xt_len = sizeof xt; 1339 /* XXX should avoid extra copy */ 1340 bcopy(inp, &xt.xt_inp, sizeof *inp); 1341 inp_ppcb = inp->inp_ppcb; 1342 if (inp_ppcb == NULL) 1343 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1344 else if (inp->inp_flags & INP_TIMEWAIT) { 1345 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1346 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1347 } else { 1348 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1349 if (xt.xt_tp.t_timers) 1350 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1351 } 1352 if (inp->inp_socket != NULL) 1353 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1354 else { 1355 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1356 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1357 } 1358 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1359 INP_RUNLOCK(inp); 1360 error = SYSCTL_OUT(req, &xt, sizeof xt); 1361 } else 1362 INP_RUNLOCK(inp); 1363 } 1364 INP_INFO_RLOCK(&V_tcbinfo); 1365 for (i = 0; i < n; i++) { 1366 inp = inp_list[i]; 1367 INP_RLOCK(inp); 1368 if (!in_pcbrele_rlocked(inp)) 1369 INP_RUNLOCK(inp); 1370 } 1371 INP_INFO_RUNLOCK(&V_tcbinfo); 1372 1373 if (!error) { 1374 /* 1375 * Give the user an updated idea of our state. 1376 * If the generation differs from what we told 1377 * her before, she knows that something happened 1378 * while we were processing this request, and it 1379 * might be necessary to retry. 1380 */ 1381 INP_LIST_RLOCK(&V_tcbinfo); 1382 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1383 xig.xig_sogen = so_gencnt; 1384 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1385 INP_LIST_RUNLOCK(&V_tcbinfo); 1386 error = SYSCTL_OUT(req, &xig, sizeof xig); 1387 } 1388 free(inp_list, M_TEMP); 1389 return (error); 1390 } 1391 1392 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1393 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1394 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1395 1396 #ifdef INET 1397 static int 1398 tcp_getcred(SYSCTL_HANDLER_ARGS) 1399 { 1400 struct xucred xuc; 1401 struct sockaddr_in addrs[2]; 1402 struct inpcb *inp; 1403 int error; 1404 1405 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1406 if (error) 1407 return (error); 1408 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1409 if (error) 1410 return (error); 1411 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1412 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1413 if (inp != NULL) { 1414 if (inp->inp_socket == NULL) 1415 error = ENOENT; 1416 if (error == 0) 1417 error = cr_canseeinpcb(req->td->td_ucred, inp); 1418 if (error == 0) 1419 cru2x(inp->inp_cred, &xuc); 1420 INP_RUNLOCK(inp); 1421 } else 1422 error = ENOENT; 1423 if (error == 0) 1424 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1425 return (error); 1426 } 1427 1428 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1429 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1430 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1431 #endif /* INET */ 1432 1433 #ifdef INET6 1434 static int 1435 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1436 { 1437 struct xucred xuc; 1438 struct sockaddr_in6 addrs[2]; 1439 struct inpcb *inp; 1440 int error; 1441 #ifdef INET 1442 int mapped = 0; 1443 #endif 1444 1445 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1446 if (error) 1447 return (error); 1448 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1449 if (error) 1450 return (error); 1451 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1452 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1453 return (error); 1454 } 1455 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1456 #ifdef INET 1457 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1458 mapped = 1; 1459 else 1460 #endif 1461 return (EINVAL); 1462 } 1463 1464 #ifdef INET 1465 if (mapped == 1) 1466 inp = in_pcblookup(&V_tcbinfo, 1467 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1468 addrs[1].sin6_port, 1469 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1470 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1471 else 1472 #endif 1473 inp = in6_pcblookup(&V_tcbinfo, 1474 &addrs[1].sin6_addr, addrs[1].sin6_port, 1475 &addrs[0].sin6_addr, addrs[0].sin6_port, 1476 INPLOOKUP_RLOCKPCB, NULL); 1477 if (inp != NULL) { 1478 if (inp->inp_socket == NULL) 1479 error = ENOENT; 1480 if (error == 0) 1481 error = cr_canseeinpcb(req->td->td_ucred, inp); 1482 if (error == 0) 1483 cru2x(inp->inp_cred, &xuc); 1484 INP_RUNLOCK(inp); 1485 } else 1486 error = ENOENT; 1487 if (error == 0) 1488 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1489 return (error); 1490 } 1491 1492 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1493 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1494 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1495 #endif /* INET6 */ 1496 1497 1498 #ifdef INET 1499 void 1500 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1501 { 1502 struct ip *ip = vip; 1503 struct tcphdr *th; 1504 struct in_addr faddr; 1505 struct inpcb *inp; 1506 struct tcpcb *tp; 1507 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1508 struct icmp *icp; 1509 struct in_conninfo inc; 1510 tcp_seq icmp_tcp_seq; 1511 int mtu; 1512 1513 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1514 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1515 return; 1516 1517 if (cmd == PRC_MSGSIZE) 1518 notify = tcp_mtudisc_notify; 1519 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1520 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1521 notify = tcp_drop_syn_sent; 1522 /* 1523 * Redirects don't need to be handled up here. 1524 */ 1525 else if (PRC_IS_REDIRECT(cmd)) 1526 return; 1527 /* 1528 * Hostdead is ugly because it goes linearly through all PCBs. 1529 * XXX: We never get this from ICMP, otherwise it makes an 1530 * excellent DoS attack on machines with many connections. 1531 */ 1532 else if (cmd == PRC_HOSTDEAD) 1533 ip = NULL; 1534 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1535 return; 1536 1537 if (ip == NULL) { 1538 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1539 return; 1540 } 1541 1542 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1543 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1544 INP_INFO_RLOCK(&V_tcbinfo); 1545 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1546 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1547 if (inp != NULL) { 1548 if (!(inp->inp_flags & INP_TIMEWAIT) && 1549 !(inp->inp_flags & INP_DROPPED) && 1550 !(inp->inp_socket == NULL)) { 1551 icmp_tcp_seq = ntohl(th->th_seq); 1552 tp = intotcpcb(inp); 1553 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1554 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1555 if (cmd == PRC_MSGSIZE) { 1556 /* 1557 * MTU discovery: 1558 * If we got a needfrag set the MTU 1559 * in the route to the suggested new 1560 * value (if given) and then notify. 1561 */ 1562 mtu = ntohs(icp->icmp_nextmtu); 1563 /* 1564 * If no alternative MTU was 1565 * proposed, try the next smaller 1566 * one. 1567 */ 1568 if (!mtu) 1569 mtu = ip_next_mtu( 1570 ntohs(ip->ip_len), 1); 1571 if (mtu < V_tcp_minmss + 1572 sizeof(struct tcpiphdr)) 1573 mtu = V_tcp_minmss + 1574 sizeof(struct tcpiphdr); 1575 /* 1576 * Only process the offered MTU if it 1577 * is smaller than the current one. 1578 */ 1579 if (mtu < tp->t_maxopd + 1580 sizeof(struct tcpiphdr)) { 1581 bzero(&inc, sizeof(inc)); 1582 inc.inc_faddr = faddr; 1583 inc.inc_fibnum = 1584 inp->inp_inc.inc_fibnum; 1585 tcp_hc_updatemtu(&inc, mtu); 1586 tcp_mtudisc(inp, mtu); 1587 } 1588 } else 1589 inp = (*notify)(inp, 1590 inetctlerrmap[cmd]); 1591 } 1592 } 1593 if (inp != NULL) 1594 INP_WUNLOCK(inp); 1595 } else { 1596 bzero(&inc, sizeof(inc)); 1597 inc.inc_fport = th->th_dport; 1598 inc.inc_lport = th->th_sport; 1599 inc.inc_faddr = faddr; 1600 inc.inc_laddr = ip->ip_src; 1601 syncache_unreach(&inc, th); 1602 } 1603 INP_INFO_RUNLOCK(&V_tcbinfo); 1604 } 1605 #endif /* INET */ 1606 1607 #ifdef INET6 1608 void 1609 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1610 { 1611 struct tcphdr th; 1612 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1613 struct ip6_hdr *ip6; 1614 struct mbuf *m; 1615 struct ip6ctlparam *ip6cp = NULL; 1616 const struct sockaddr_in6 *sa6_src = NULL; 1617 int off; 1618 struct tcp_portonly { 1619 u_int16_t th_sport; 1620 u_int16_t th_dport; 1621 } *thp; 1622 1623 if (sa->sa_family != AF_INET6 || 1624 sa->sa_len != sizeof(struct sockaddr_in6)) 1625 return; 1626 1627 if (cmd == PRC_MSGSIZE) 1628 notify = tcp_mtudisc_notify; 1629 else if (!PRC_IS_REDIRECT(cmd) && 1630 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1631 return; 1632 1633 /* if the parameter is from icmp6, decode it. */ 1634 if (d != NULL) { 1635 ip6cp = (struct ip6ctlparam *)d; 1636 m = ip6cp->ip6c_m; 1637 ip6 = ip6cp->ip6c_ip6; 1638 off = ip6cp->ip6c_off; 1639 sa6_src = ip6cp->ip6c_src; 1640 } else { 1641 m = NULL; 1642 ip6 = NULL; 1643 off = 0; /* fool gcc */ 1644 sa6_src = &sa6_any; 1645 } 1646 1647 if (ip6 != NULL) { 1648 struct in_conninfo inc; 1649 /* 1650 * XXX: We assume that when IPV6 is non NULL, 1651 * M and OFF are valid. 1652 */ 1653 1654 /* check if we can safely examine src and dst ports */ 1655 if (m->m_pkthdr.len < off + sizeof(*thp)) 1656 return; 1657 1658 bzero(&th, sizeof(th)); 1659 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1660 1661 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1662 (struct sockaddr *)ip6cp->ip6c_src, 1663 th.th_sport, cmd, NULL, notify); 1664 1665 bzero(&inc, sizeof(inc)); 1666 inc.inc_fport = th.th_dport; 1667 inc.inc_lport = th.th_sport; 1668 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1669 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1670 inc.inc_flags |= INC_ISIPV6; 1671 INP_INFO_RLOCK(&V_tcbinfo); 1672 syncache_unreach(&inc, &th); 1673 INP_INFO_RUNLOCK(&V_tcbinfo); 1674 } else 1675 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1676 0, cmd, NULL, notify); 1677 } 1678 #endif /* INET6 */ 1679 1680 1681 /* 1682 * Following is where TCP initial sequence number generation occurs. 1683 * 1684 * There are two places where we must use initial sequence numbers: 1685 * 1. In SYN-ACK packets. 1686 * 2. In SYN packets. 1687 * 1688 * All ISNs for SYN-ACK packets are generated by the syncache. See 1689 * tcp_syncache.c for details. 1690 * 1691 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1692 * depends on this property. In addition, these ISNs should be 1693 * unguessable so as to prevent connection hijacking. To satisfy 1694 * the requirements of this situation, the algorithm outlined in 1695 * RFC 1948 is used, with only small modifications. 1696 * 1697 * Implementation details: 1698 * 1699 * Time is based off the system timer, and is corrected so that it 1700 * increases by one megabyte per second. This allows for proper 1701 * recycling on high speed LANs while still leaving over an hour 1702 * before rollover. 1703 * 1704 * As reading the *exact* system time is too expensive to be done 1705 * whenever setting up a TCP connection, we increment the time 1706 * offset in two ways. First, a small random positive increment 1707 * is added to isn_offset for each connection that is set up. 1708 * Second, the function tcp_isn_tick fires once per clock tick 1709 * and increments isn_offset as necessary so that sequence numbers 1710 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1711 * random positive increments serve only to ensure that the same 1712 * exact sequence number is never sent out twice (as could otherwise 1713 * happen when a port is recycled in less than the system tick 1714 * interval.) 1715 * 1716 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1717 * between seeding of isn_secret. This is normally set to zero, 1718 * as reseeding should not be necessary. 1719 * 1720 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1721 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1722 * general, this means holding an exclusive (write) lock. 1723 */ 1724 1725 #define ISN_BYTES_PER_SECOND 1048576 1726 #define ISN_STATIC_INCREMENT 4096 1727 #define ISN_RANDOM_INCREMENT (4096 - 1) 1728 1729 static VNET_DEFINE(u_char, isn_secret[32]); 1730 static VNET_DEFINE(int, isn_last); 1731 static VNET_DEFINE(int, isn_last_reseed); 1732 static VNET_DEFINE(u_int32_t, isn_offset); 1733 static VNET_DEFINE(u_int32_t, isn_offset_old); 1734 1735 #define V_isn_secret VNET(isn_secret) 1736 #define V_isn_last VNET(isn_last) 1737 #define V_isn_last_reseed VNET(isn_last_reseed) 1738 #define V_isn_offset VNET(isn_offset) 1739 #define V_isn_offset_old VNET(isn_offset_old) 1740 1741 tcp_seq 1742 tcp_new_isn(struct tcpcb *tp) 1743 { 1744 MD5_CTX isn_ctx; 1745 u_int32_t md5_buffer[4]; 1746 tcp_seq new_isn; 1747 u_int32_t projected_offset; 1748 1749 INP_WLOCK_ASSERT(tp->t_inpcb); 1750 1751 ISN_LOCK(); 1752 /* Seed if this is the first use, reseed if requested. */ 1753 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1754 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1755 < (u_int)ticks))) { 1756 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1757 V_isn_last_reseed = ticks; 1758 } 1759 1760 /* Compute the md5 hash and return the ISN. */ 1761 MD5Init(&isn_ctx); 1762 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1763 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1764 #ifdef INET6 1765 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1766 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1767 sizeof(struct in6_addr)); 1768 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1769 sizeof(struct in6_addr)); 1770 } else 1771 #endif 1772 { 1773 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1774 sizeof(struct in_addr)); 1775 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1776 sizeof(struct in_addr)); 1777 } 1778 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1779 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1780 new_isn = (tcp_seq) md5_buffer[0]; 1781 V_isn_offset += ISN_STATIC_INCREMENT + 1782 (arc4random() & ISN_RANDOM_INCREMENT); 1783 if (ticks != V_isn_last) { 1784 projected_offset = V_isn_offset_old + 1785 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1786 if (SEQ_GT(projected_offset, V_isn_offset)) 1787 V_isn_offset = projected_offset; 1788 V_isn_offset_old = V_isn_offset; 1789 V_isn_last = ticks; 1790 } 1791 new_isn += V_isn_offset; 1792 ISN_UNLOCK(); 1793 return (new_isn); 1794 } 1795 1796 /* 1797 * When a specific ICMP unreachable message is received and the 1798 * connection state is SYN-SENT, drop the connection. This behavior 1799 * is controlled by the icmp_may_rst sysctl. 1800 */ 1801 struct inpcb * 1802 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1803 { 1804 struct tcpcb *tp; 1805 1806 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 1807 INP_WLOCK_ASSERT(inp); 1808 1809 if ((inp->inp_flags & INP_TIMEWAIT) || 1810 (inp->inp_flags & INP_DROPPED)) 1811 return (inp); 1812 1813 tp = intotcpcb(inp); 1814 if (tp->t_state != TCPS_SYN_SENT) 1815 return (inp); 1816 1817 tp = tcp_drop(tp, errno); 1818 if (tp != NULL) 1819 return (inp); 1820 else 1821 return (NULL); 1822 } 1823 1824 /* 1825 * When `need fragmentation' ICMP is received, update our idea of the MSS 1826 * based on the new value. Also nudge TCP to send something, since we 1827 * know the packet we just sent was dropped. 1828 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1829 */ 1830 static struct inpcb * 1831 tcp_mtudisc_notify(struct inpcb *inp, int error) 1832 { 1833 1834 tcp_mtudisc(inp, -1); 1835 return (inp); 1836 } 1837 1838 static void 1839 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1840 { 1841 struct tcpcb *tp; 1842 struct socket *so; 1843 1844 INP_WLOCK_ASSERT(inp); 1845 if ((inp->inp_flags & INP_TIMEWAIT) || 1846 (inp->inp_flags & INP_DROPPED)) 1847 return; 1848 1849 tp = intotcpcb(inp); 1850 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1851 1852 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1853 1854 so = inp->inp_socket; 1855 SOCKBUF_LOCK(&so->so_snd); 1856 /* If the mss is larger than the socket buffer, decrease the mss. */ 1857 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1858 tp->t_maxseg = so->so_snd.sb_hiwat; 1859 SOCKBUF_UNLOCK(&so->so_snd); 1860 1861 TCPSTAT_INC(tcps_mturesent); 1862 tp->t_rtttime = 0; 1863 tp->snd_nxt = tp->snd_una; 1864 tcp_free_sackholes(tp); 1865 tp->snd_recover = tp->snd_max; 1866 if (tp->t_flags & TF_SACK_PERMIT) 1867 EXIT_FASTRECOVERY(tp->t_flags); 1868 tcp_output(tp); 1869 } 1870 1871 #ifdef INET 1872 /* 1873 * Look-up the routing entry to the peer of this inpcb. If no route 1874 * is found and it cannot be allocated, then return 0. This routine 1875 * is called by TCP routines that access the rmx structure and by 1876 * tcp_mss_update to get the peer/interface MTU. 1877 */ 1878 u_long 1879 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 1880 { 1881 struct route sro; 1882 struct sockaddr_in *dst; 1883 struct ifnet *ifp; 1884 u_long maxmtu = 0; 1885 1886 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1887 1888 bzero(&sro, sizeof(sro)); 1889 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1890 dst = (struct sockaddr_in *)&sro.ro_dst; 1891 dst->sin_family = AF_INET; 1892 dst->sin_len = sizeof(*dst); 1893 dst->sin_addr = inc->inc_faddr; 1894 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1895 } 1896 if (sro.ro_rt != NULL) { 1897 ifp = sro.ro_rt->rt_ifp; 1898 if (sro.ro_rt->rt_mtu == 0) 1899 maxmtu = ifp->if_mtu; 1900 else 1901 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu); 1902 1903 /* Report additional interface capabilities. */ 1904 if (cap != NULL) { 1905 if (ifp->if_capenable & IFCAP_TSO4 && 1906 ifp->if_hwassist & CSUM_TSO) { 1907 cap->ifcap |= CSUM_TSO; 1908 cap->tsomax = ifp->if_hw_tsomax; 1909 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1910 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1911 } 1912 } 1913 RTFREE(sro.ro_rt); 1914 } 1915 return (maxmtu); 1916 } 1917 #endif /* INET */ 1918 1919 #ifdef INET6 1920 u_long 1921 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 1922 { 1923 struct route_in6 sro6; 1924 struct ifnet *ifp; 1925 u_long maxmtu = 0; 1926 1927 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1928 1929 bzero(&sro6, sizeof(sro6)); 1930 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1931 sro6.ro_dst.sin6_family = AF_INET6; 1932 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1933 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1934 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 1935 } 1936 if (sro6.ro_rt != NULL) { 1937 ifp = sro6.ro_rt->rt_ifp; 1938 if (sro6.ro_rt->rt_mtu == 0) 1939 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1940 else 1941 maxmtu = min(sro6.ro_rt->rt_mtu, 1942 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1943 1944 /* Report additional interface capabilities. */ 1945 if (cap != NULL) { 1946 if (ifp->if_capenable & IFCAP_TSO6 && 1947 ifp->if_hwassist & CSUM_TSO) { 1948 cap->ifcap |= CSUM_TSO; 1949 cap->tsomax = ifp->if_hw_tsomax; 1950 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 1951 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 1952 } 1953 } 1954 RTFREE(sro6.ro_rt); 1955 } 1956 1957 return (maxmtu); 1958 } 1959 #endif /* INET6 */ 1960 1961 #ifdef IPSEC 1962 /* compute ESP/AH header size for TCP, including outer IP header. */ 1963 size_t 1964 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1965 { 1966 struct inpcb *inp; 1967 struct mbuf *m; 1968 size_t hdrsiz; 1969 struct ip *ip; 1970 #ifdef INET6 1971 struct ip6_hdr *ip6; 1972 #endif 1973 struct tcphdr *th; 1974 1975 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL) || 1976 (!key_havesp(IPSEC_DIR_OUTBOUND))) 1977 return (0); 1978 m = m_gethdr(M_NOWAIT, MT_DATA); 1979 if (!m) 1980 return (0); 1981 1982 #ifdef INET6 1983 if ((inp->inp_vflag & INP_IPV6) != 0) { 1984 ip6 = mtod(m, struct ip6_hdr *); 1985 th = (struct tcphdr *)(ip6 + 1); 1986 m->m_pkthdr.len = m->m_len = 1987 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1988 tcpip_fillheaders(inp, ip6, th); 1989 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1990 } else 1991 #endif /* INET6 */ 1992 { 1993 ip = mtod(m, struct ip *); 1994 th = (struct tcphdr *)(ip + 1); 1995 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1996 tcpip_fillheaders(inp, ip, th); 1997 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1998 } 1999 2000 m_free(m); 2001 return (hdrsiz); 2002 } 2003 #endif /* IPSEC */ 2004 2005 #ifdef TCP_SIGNATURE 2006 /* 2007 * Callback function invoked by m_apply() to digest TCP segment data 2008 * contained within an mbuf chain. 2009 */ 2010 static int 2011 tcp_signature_apply(void *fstate, void *data, u_int len) 2012 { 2013 2014 MD5Update(fstate, (u_char *)data, len); 2015 return (0); 2016 } 2017 2018 /* 2019 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2020 * search with the destination IP address, and a 'magic SPI' to be 2021 * determined by the application. This is hardcoded elsewhere to 1179 2022 */ 2023 struct secasvar * 2024 tcp_get_sav(struct mbuf *m, u_int direction) 2025 { 2026 union sockaddr_union dst; 2027 struct secasvar *sav; 2028 struct ip *ip; 2029 #ifdef INET6 2030 struct ip6_hdr *ip6; 2031 char ip6buf[INET6_ADDRSTRLEN]; 2032 #endif 2033 2034 /* Extract the destination from the IP header in the mbuf. */ 2035 bzero(&dst, sizeof(union sockaddr_union)); 2036 ip = mtod(m, struct ip *); 2037 #ifdef INET6 2038 ip6 = NULL; /* Make the compiler happy. */ 2039 #endif 2040 switch (ip->ip_v) { 2041 #ifdef INET 2042 case IPVERSION: 2043 dst.sa.sa_len = sizeof(struct sockaddr_in); 2044 dst.sa.sa_family = AF_INET; 2045 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2046 ip->ip_src : ip->ip_dst; 2047 break; 2048 #endif 2049 #ifdef INET6 2050 case (IPV6_VERSION >> 4): 2051 ip6 = mtod(m, struct ip6_hdr *); 2052 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2053 dst.sa.sa_family = AF_INET6; 2054 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2055 ip6->ip6_src : ip6->ip6_dst; 2056 break; 2057 #endif 2058 default: 2059 return (NULL); 2060 /* NOTREACHED */ 2061 break; 2062 } 2063 2064 /* Look up an SADB entry which matches the address of the peer. */ 2065 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2066 if (sav == NULL) { 2067 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2068 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2069 #ifdef INET6 2070 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2071 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2072 #endif 2073 "(unsupported)")); 2074 } 2075 2076 return (sav); 2077 } 2078 2079 /* 2080 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2081 * 2082 * Parameters: 2083 * m pointer to head of mbuf chain 2084 * len length of TCP segment data, excluding options 2085 * optlen length of TCP segment options 2086 * buf pointer to storage for computed MD5 digest 2087 * sav pointer to security assosiation 2088 * 2089 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2090 * When called from tcp_input(), we can be sure that th_sum has been 2091 * zeroed out and verified already. 2092 * 2093 * Releases reference to SADB key before return. 2094 * 2095 * Return 0 if successful, otherwise return -1. 2096 * 2097 */ 2098 int 2099 tcp_signature_do_compute(struct mbuf *m, int len, int optlen, 2100 u_char *buf, struct secasvar *sav) 2101 { 2102 #ifdef INET 2103 struct ippseudo ippseudo; 2104 #endif 2105 MD5_CTX ctx; 2106 int doff; 2107 struct ip *ip; 2108 #ifdef INET 2109 struct ipovly *ipovly; 2110 #endif 2111 struct tcphdr *th; 2112 #ifdef INET6 2113 struct ip6_hdr *ip6; 2114 struct in6_addr in6; 2115 uint32_t plen; 2116 uint16_t nhdr; 2117 #endif 2118 u_short savecsum; 2119 2120 KASSERT(m != NULL, ("NULL mbuf chain")); 2121 KASSERT(buf != NULL, ("NULL signature pointer")); 2122 2123 /* Extract the destination from the IP header in the mbuf. */ 2124 ip = mtod(m, struct ip *); 2125 #ifdef INET6 2126 ip6 = NULL; /* Make the compiler happy. */ 2127 #endif 2128 2129 MD5Init(&ctx); 2130 /* 2131 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2132 * 2133 * XXX The ippseudo header MUST be digested in network byte order, 2134 * or else we'll fail the regression test. Assume all fields we've 2135 * been doing arithmetic on have been in host byte order. 2136 * XXX One cannot depend on ipovly->ih_len here. When called from 2137 * tcp_output(), the underlying ip_len member has not yet been set. 2138 */ 2139 switch (ip->ip_v) { 2140 #ifdef INET 2141 case IPVERSION: 2142 ipovly = (struct ipovly *)ip; 2143 ippseudo.ippseudo_src = ipovly->ih_src; 2144 ippseudo.ippseudo_dst = ipovly->ih_dst; 2145 ippseudo.ippseudo_pad = 0; 2146 ippseudo.ippseudo_p = IPPROTO_TCP; 2147 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2148 optlen); 2149 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2150 2151 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2152 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2153 break; 2154 #endif 2155 #ifdef INET6 2156 /* 2157 * RFC 2385, 2.0 Proposal 2158 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2159 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2160 * extended next header value (to form 32 bits), and 32-bit segment 2161 * length. 2162 * Note: Upper-Layer Packet Length comes before Next Header. 2163 */ 2164 case (IPV6_VERSION >> 4): 2165 in6 = ip6->ip6_src; 2166 in6_clearscope(&in6); 2167 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2168 in6 = ip6->ip6_dst; 2169 in6_clearscope(&in6); 2170 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2171 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2172 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2173 nhdr = 0; 2174 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2175 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2176 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2177 nhdr = IPPROTO_TCP; 2178 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2179 2180 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2181 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2182 break; 2183 #endif 2184 default: 2185 KEY_FREESAV(&sav); 2186 return (-1); 2187 /* NOTREACHED */ 2188 break; 2189 } 2190 2191 2192 /* 2193 * Step 2: Update MD5 hash with TCP header, excluding options. 2194 * The TCP checksum must be set to zero. 2195 */ 2196 savecsum = th->th_sum; 2197 th->th_sum = 0; 2198 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2199 th->th_sum = savecsum; 2200 2201 /* 2202 * Step 3: Update MD5 hash with TCP segment data. 2203 * Use m_apply() to avoid an early m_pullup(). 2204 */ 2205 if (len > 0) 2206 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2207 2208 /* 2209 * Step 4: Update MD5 hash with shared secret. 2210 */ 2211 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2212 MD5Final(buf, &ctx); 2213 2214 key_sa_recordxfer(sav, m); 2215 KEY_FREESAV(&sav); 2216 return (0); 2217 } 2218 2219 /* 2220 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2221 * 2222 * Return 0 if successful, otherwise return -1. 2223 */ 2224 int 2225 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2226 u_char *buf, u_int direction) 2227 { 2228 struct secasvar *sav; 2229 2230 if ((sav = tcp_get_sav(m, direction)) == NULL) 2231 return (-1); 2232 2233 return (tcp_signature_do_compute(m, len, optlen, buf, sav)); 2234 } 2235 2236 /* 2237 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2238 * 2239 * Parameters: 2240 * m pointer to head of mbuf chain 2241 * len length of TCP segment data, excluding options 2242 * optlen length of TCP segment options 2243 * buf pointer to storage for computed MD5 digest 2244 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2245 * 2246 * Return 1 if successful, otherwise return 0. 2247 */ 2248 int 2249 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2250 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2251 { 2252 char tmpdigest[TCP_SIGLEN]; 2253 2254 if (tcp_sig_checksigs == 0) 2255 return (1); 2256 if ((tcpbflag & TF_SIGNATURE) == 0) { 2257 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2258 2259 /* 2260 * If this socket is not expecting signature but 2261 * the segment contains signature just fail. 2262 */ 2263 TCPSTAT_INC(tcps_sig_err_sigopt); 2264 TCPSTAT_INC(tcps_sig_rcvbadsig); 2265 return (0); 2266 } 2267 2268 /* Signature is not expected, and not present in segment. */ 2269 return (1); 2270 } 2271 2272 /* 2273 * If this socket is expecting signature but the segment does not 2274 * contain any just fail. 2275 */ 2276 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2277 TCPSTAT_INC(tcps_sig_err_nosigopt); 2278 TCPSTAT_INC(tcps_sig_rcvbadsig); 2279 return (0); 2280 } 2281 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2282 IPSEC_DIR_INBOUND) == -1) { 2283 TCPSTAT_INC(tcps_sig_err_buildsig); 2284 TCPSTAT_INC(tcps_sig_rcvbadsig); 2285 return (0); 2286 } 2287 2288 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2289 TCPSTAT_INC(tcps_sig_rcvbadsig); 2290 return (0); 2291 } 2292 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2293 return (1); 2294 } 2295 #endif /* TCP_SIGNATURE */ 2296 2297 static int 2298 sysctl_drop(SYSCTL_HANDLER_ARGS) 2299 { 2300 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2301 struct sockaddr_storage addrs[2]; 2302 struct inpcb *inp; 2303 struct tcpcb *tp; 2304 struct tcptw *tw; 2305 struct sockaddr_in *fin, *lin; 2306 #ifdef INET6 2307 struct sockaddr_in6 *fin6, *lin6; 2308 #endif 2309 int error; 2310 2311 inp = NULL; 2312 fin = lin = NULL; 2313 #ifdef INET6 2314 fin6 = lin6 = NULL; 2315 #endif 2316 error = 0; 2317 2318 if (req->oldptr != NULL || req->oldlen != 0) 2319 return (EINVAL); 2320 if (req->newptr == NULL) 2321 return (EPERM); 2322 if (req->newlen < sizeof(addrs)) 2323 return (ENOMEM); 2324 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2325 if (error) 2326 return (error); 2327 2328 switch (addrs[0].ss_family) { 2329 #ifdef INET6 2330 case AF_INET6: 2331 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2332 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2333 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2334 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2335 return (EINVAL); 2336 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2337 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2338 return (EINVAL); 2339 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2340 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2341 fin = (struct sockaddr_in *)&addrs[0]; 2342 lin = (struct sockaddr_in *)&addrs[1]; 2343 break; 2344 } 2345 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2346 if (error) 2347 return (error); 2348 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2349 if (error) 2350 return (error); 2351 break; 2352 #endif 2353 #ifdef INET 2354 case AF_INET: 2355 fin = (struct sockaddr_in *)&addrs[0]; 2356 lin = (struct sockaddr_in *)&addrs[1]; 2357 if (fin->sin_len != sizeof(struct sockaddr_in) || 2358 lin->sin_len != sizeof(struct sockaddr_in)) 2359 return (EINVAL); 2360 break; 2361 #endif 2362 default: 2363 return (EINVAL); 2364 } 2365 INP_INFO_RLOCK(&V_tcbinfo); 2366 switch (addrs[0].ss_family) { 2367 #ifdef INET6 2368 case AF_INET6: 2369 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2370 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2371 INPLOOKUP_WLOCKPCB, NULL); 2372 break; 2373 #endif 2374 #ifdef INET 2375 case AF_INET: 2376 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2377 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2378 break; 2379 #endif 2380 } 2381 if (inp != NULL) { 2382 if (inp->inp_flags & INP_TIMEWAIT) { 2383 /* 2384 * XXXRW: There currently exists a state where an 2385 * inpcb is present, but its timewait state has been 2386 * discarded. For now, don't allow dropping of this 2387 * type of inpcb. 2388 */ 2389 tw = intotw(inp); 2390 if (tw != NULL) 2391 tcp_twclose(tw, 0); 2392 else 2393 INP_WUNLOCK(inp); 2394 } else if (!(inp->inp_flags & INP_DROPPED) && 2395 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2396 tp = intotcpcb(inp); 2397 tp = tcp_drop(tp, ECONNABORTED); 2398 if (tp != NULL) 2399 INP_WUNLOCK(inp); 2400 } else 2401 INP_WUNLOCK(inp); 2402 } else 2403 error = ESRCH; 2404 INP_INFO_RUNLOCK(&V_tcbinfo); 2405 return (error); 2406 } 2407 2408 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2409 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2410 0, sysctl_drop, "", "Drop TCP connection"); 2411 2412 /* 2413 * Generate a standardized TCP log line for use throughout the 2414 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2415 * allow use in the interrupt context. 2416 * 2417 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2418 * NB: The function may return NULL if memory allocation failed. 2419 * 2420 * Due to header inclusion and ordering limitations the struct ip 2421 * and ip6_hdr pointers have to be passed as void pointers. 2422 */ 2423 char * 2424 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2425 const void *ip6hdr) 2426 { 2427 2428 /* Is logging enabled? */ 2429 if (tcp_log_in_vain == 0) 2430 return (NULL); 2431 2432 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2433 } 2434 2435 char * 2436 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2437 const void *ip6hdr) 2438 { 2439 2440 /* Is logging enabled? */ 2441 if (tcp_log_debug == 0) 2442 return (NULL); 2443 2444 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2445 } 2446 2447 static char * 2448 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2449 const void *ip6hdr) 2450 { 2451 char *s, *sp; 2452 size_t size; 2453 struct ip *ip; 2454 #ifdef INET6 2455 const struct ip6_hdr *ip6; 2456 2457 ip6 = (const struct ip6_hdr *)ip6hdr; 2458 #endif /* INET6 */ 2459 ip = (struct ip *)ip4hdr; 2460 2461 /* 2462 * The log line looks like this: 2463 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2464 */ 2465 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2466 sizeof(PRINT_TH_FLAGS) + 1 + 2467 #ifdef INET6 2468 2 * INET6_ADDRSTRLEN; 2469 #else 2470 2 * INET_ADDRSTRLEN; 2471 #endif /* INET6 */ 2472 2473 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2474 if (s == NULL) 2475 return (NULL); 2476 2477 strcat(s, "TCP: ["); 2478 sp = s + strlen(s); 2479 2480 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2481 inet_ntoa_r(inc->inc_faddr, sp); 2482 sp = s + strlen(s); 2483 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2484 sp = s + strlen(s); 2485 inet_ntoa_r(inc->inc_laddr, sp); 2486 sp = s + strlen(s); 2487 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2488 #ifdef INET6 2489 } else if (inc) { 2490 ip6_sprintf(sp, &inc->inc6_faddr); 2491 sp = s + strlen(s); 2492 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2493 sp = s + strlen(s); 2494 ip6_sprintf(sp, &inc->inc6_laddr); 2495 sp = s + strlen(s); 2496 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2497 } else if (ip6 && th) { 2498 ip6_sprintf(sp, &ip6->ip6_src); 2499 sp = s + strlen(s); 2500 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2501 sp = s + strlen(s); 2502 ip6_sprintf(sp, &ip6->ip6_dst); 2503 sp = s + strlen(s); 2504 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2505 #endif /* INET6 */ 2506 #ifdef INET 2507 } else if (ip && th) { 2508 inet_ntoa_r(ip->ip_src, sp); 2509 sp = s + strlen(s); 2510 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2511 sp = s + strlen(s); 2512 inet_ntoa_r(ip->ip_dst, sp); 2513 sp = s + strlen(s); 2514 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2515 #endif /* INET */ 2516 } else { 2517 free(s, M_TCPLOG); 2518 return (NULL); 2519 } 2520 sp = s + strlen(s); 2521 if (th) 2522 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2523 if (*(s + size - 1) != '\0') 2524 panic("%s: string too long", __func__); 2525 return (s); 2526 } 2527 2528 /* 2529 * A subroutine which makes it easy to track TCP state changes with DTrace. 2530 * This function shouldn't be called for t_state initializations that don't 2531 * correspond to actual TCP state transitions. 2532 */ 2533 void 2534 tcp_state_change(struct tcpcb *tp, int newstate) 2535 { 2536 #if defined(KDTRACE_HOOKS) 2537 int pstate = tp->t_state; 2538 #endif 2539 2540 tp->t_state = newstate; 2541 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2542 } 2543