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/socket.h> 57 #include <sys/socketvar.h> 58 #include <sys/protosw.h> 59 #include <sys/random.h> 60 61 #include <vm/uma.h> 62 63 #include <net/route.h> 64 #include <net/if.h> 65 #include <net/vnet.h> 66 67 #include <netinet/cc.h> 68 #include <netinet/in.h> 69 #include <netinet/in_pcb.h> 70 #include <netinet/in_systm.h> 71 #include <netinet/in_var.h> 72 #include <netinet/ip.h> 73 #include <netinet/ip_icmp.h> 74 #include <netinet/ip_var.h> 75 #ifdef INET6 76 #include <netinet/ip6.h> 77 #include <netinet6/in6_pcb.h> 78 #include <netinet6/ip6_var.h> 79 #include <netinet6/scope6_var.h> 80 #include <netinet6/nd6.h> 81 #endif 82 83 #include <netinet/tcp_fsm.h> 84 #include <netinet/tcp_seq.h> 85 #include <netinet/tcp_timer.h> 86 #include <netinet/tcp_var.h> 87 #include <netinet/tcp_syncache.h> 88 #ifdef INET6 89 #include <netinet6/tcp6_var.h> 90 #endif 91 #include <netinet/tcpip.h> 92 #ifdef TCPDEBUG 93 #include <netinet/tcp_debug.h> 94 #endif 95 #ifdef INET6 96 #include <netinet6/ip6protosw.h> 97 #endif 98 #ifdef TCP_OFFLOAD 99 #include <netinet/tcp_offload.h> 100 #endif 101 102 #ifdef IPSEC 103 #include <netipsec/ipsec.h> 104 #include <netipsec/xform.h> 105 #ifdef INET6 106 #include <netipsec/ipsec6.h> 107 #endif 108 #include <netipsec/key.h> 109 #include <sys/syslog.h> 110 #endif /*IPSEC*/ 111 112 #include <machine/in_cksum.h> 113 #include <sys/md5.h> 114 115 #include <security/mac/mac_framework.h> 116 117 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 118 #ifdef INET6 119 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 120 #endif 121 122 static int 123 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 124 { 125 int error, new; 126 127 new = V_tcp_mssdflt; 128 error = sysctl_handle_int(oidp, &new, 0, req); 129 if (error == 0 && req->newptr) { 130 if (new < TCP_MINMSS) 131 error = EINVAL; 132 else 133 V_tcp_mssdflt = new; 134 } 135 return (error); 136 } 137 138 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 139 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 140 &sysctl_net_inet_tcp_mss_check, "I", 141 "Default TCP Maximum Segment Size"); 142 143 #ifdef INET6 144 static int 145 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 146 { 147 int error, new; 148 149 new = V_tcp_v6mssdflt; 150 error = sysctl_handle_int(oidp, &new, 0, req); 151 if (error == 0 && req->newptr) { 152 if (new < TCP_MINMSS) 153 error = EINVAL; 154 else 155 V_tcp_v6mssdflt = new; 156 } 157 return (error); 158 } 159 160 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 161 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 162 &sysctl_net_inet_tcp_mss_v6_check, "I", 163 "Default TCP Maximum Segment Size for IPv6"); 164 #endif /* INET6 */ 165 166 /* 167 * Minimum MSS we accept and use. This prevents DoS attacks where 168 * we are forced to a ridiculous low MSS like 20 and send hundreds 169 * of packets instead of one. The effect scales with the available 170 * bandwidth and quickly saturates the CPU and network interface 171 * with packet generation and sending. Set to zero to disable MINMSS 172 * checking. This setting prevents us from sending too small packets. 173 */ 174 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 175 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 176 &VNET_NAME(tcp_minmss), 0, 177 "Minmum TCP Maximum Segment Size"); 178 179 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 180 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 181 &VNET_NAME(tcp_do_rfc1323), 0, 182 "Enable rfc1323 (high performance TCP) extensions"); 183 184 static int tcp_log_debug = 0; 185 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 186 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 187 188 static int tcp_tcbhashsize = 0; 189 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 190 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 191 192 static int do_tcpdrain = 1; 193 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 194 "Enable tcp_drain routine for extra help when low on mbufs"); 195 196 SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 197 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 198 199 static VNET_DEFINE(int, icmp_may_rst) = 1; 200 #define V_icmp_may_rst VNET(icmp_may_rst) 201 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, 202 &VNET_NAME(icmp_may_rst), 0, 203 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 204 205 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 206 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 207 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 208 &VNET_NAME(tcp_isn_reseed_interval), 0, 209 "Seconds between reseeding of ISN secret"); 210 211 static int tcp_soreceive_stream = 0; 212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 213 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 214 215 #ifdef TCP_SIGNATURE 216 static int tcp_sig_checksigs = 1; 217 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW, 218 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic"); 219 #endif 220 221 VNET_DEFINE(uma_zone_t, sack_hole_zone); 222 #define V_sack_hole_zone VNET(sack_hole_zone) 223 224 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 225 226 static struct inpcb *tcp_notify(struct inpcb *, int); 227 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 228 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 229 void *ip4hdr, const void *ip6hdr); 230 231 /* 232 * Target size of TCP PCB hash tables. Must be a power of two. 233 * 234 * Note that this can be overridden by the kernel environment 235 * variable net.inet.tcp.tcbhashsize 236 */ 237 #ifndef TCBHASHSIZE 238 #define TCBHASHSIZE 0 239 #endif 240 241 /* 242 * XXX 243 * Callouts should be moved into struct tcp directly. They are currently 244 * separate because the tcpcb structure is exported to userland for sysctl 245 * parsing purposes, which do not know about callouts. 246 */ 247 struct tcpcb_mem { 248 struct tcpcb tcb; 249 struct tcp_timer tt; 250 struct cc_var ccv; 251 struct osd osd; 252 }; 253 254 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 255 #define V_tcpcb_zone VNET(tcpcb_zone) 256 257 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 258 static struct mtx isn_mtx; 259 260 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 261 #define ISN_LOCK() mtx_lock(&isn_mtx) 262 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 263 264 /* 265 * TCP initialization. 266 */ 267 static void 268 tcp_zone_change(void *tag) 269 { 270 271 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 272 uma_zone_set_max(V_tcpcb_zone, maxsockets); 273 tcp_tw_zone_change(); 274 } 275 276 static int 277 tcp_inpcb_init(void *mem, int size, int flags) 278 { 279 struct inpcb *inp = mem; 280 281 INP_LOCK_INIT(inp, "inp", "tcpinp"); 282 return (0); 283 } 284 285 /* 286 * Take a value and get the next power of 2 that doesn't overflow. 287 * Used to size the tcp_inpcb hash buckets. 288 */ 289 static int 290 maketcp_hashsize(int size) 291 { 292 int hashsize; 293 294 /* 295 * auto tune. 296 * get the next power of 2 higher than maxsockets. 297 */ 298 hashsize = 1 << fls(size); 299 /* catch overflow, and just go one power of 2 smaller */ 300 if (hashsize < size) { 301 hashsize = 1 << (fls(size) - 1); 302 } 303 return (hashsize); 304 } 305 306 void 307 tcp_init(void) 308 { 309 const char *tcbhash_tuneable; 310 int hashsize; 311 312 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 313 314 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 315 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 316 printf("%s: WARNING: unable to register helper hook\n", __func__); 317 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 318 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 319 printf("%s: WARNING: unable to register helper hook\n", __func__); 320 321 hashsize = TCBHASHSIZE; 322 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 323 if (hashsize == 0) { 324 /* 325 * Auto tune the hash size based on maxsockets. 326 * A perfect hash would have a 1:1 mapping 327 * (hashsize = maxsockets) however it's been 328 * suggested that O(2) average is better. 329 */ 330 hashsize = maketcp_hashsize(maxsockets / 4); 331 /* 332 * Our historical default is 512, 333 * do not autotune lower than this. 334 */ 335 if (hashsize < 512) 336 hashsize = 512; 337 if (bootverbose) 338 printf("%s: %s auto tuned to %d\n", __func__, 339 tcbhash_tuneable, hashsize); 340 } 341 /* 342 * We require a hashsize to be a power of two. 343 * Previously if it was not a power of two we would just reset it 344 * back to 512, which could be a nasty surprise if you did not notice 345 * the error message. 346 * Instead what we do is clip it to the closest power of two lower 347 * than the specified hash value. 348 */ 349 if (!powerof2(hashsize)) { 350 int oldhashsize = hashsize; 351 352 hashsize = maketcp_hashsize(hashsize); 353 /* prevent absurdly low value */ 354 if (hashsize < 16) 355 hashsize = 16; 356 printf("%s: WARNING: TCB hash size not a power of 2, " 357 "clipped from %d to %d.\n", __func__, oldhashsize, 358 hashsize); 359 } 360 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 361 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE, 362 IPI_HASHFIELDS_4TUPLE); 363 364 /* 365 * These have to be type stable for the benefit of the timers. 366 */ 367 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 368 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 369 uma_zone_set_max(V_tcpcb_zone, maxsockets); 370 371 tcp_tw_init(); 372 syncache_init(); 373 tcp_hc_init(); 374 tcp_reass_init(); 375 376 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 377 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 378 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 379 380 /* Skip initialization of globals for non-default instances. */ 381 if (!IS_DEFAULT_VNET(curvnet)) 382 return; 383 384 /* XXX virtualize those bellow? */ 385 tcp_delacktime = TCPTV_DELACK; 386 tcp_keepinit = TCPTV_KEEP_INIT; 387 tcp_keepidle = TCPTV_KEEP_IDLE; 388 tcp_keepintvl = TCPTV_KEEPINTVL; 389 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 390 tcp_msl = TCPTV_MSL; 391 tcp_rexmit_min = TCPTV_MIN; 392 if (tcp_rexmit_min < 1) 393 tcp_rexmit_min = 1; 394 tcp_rexmit_slop = TCPTV_CPU_VAR; 395 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 396 tcp_tcbhashsize = hashsize; 397 398 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 399 if (tcp_soreceive_stream) { 400 #ifdef INET 401 tcp_usrreqs.pru_soreceive = soreceive_stream; 402 #endif 403 #ifdef INET6 404 tcp6_usrreqs.pru_soreceive = soreceive_stream; 405 #endif /* INET6 */ 406 } 407 408 #ifdef INET6 409 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 410 #else /* INET6 */ 411 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 412 #endif /* INET6 */ 413 if (max_protohdr < TCP_MINPROTOHDR) 414 max_protohdr = TCP_MINPROTOHDR; 415 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 416 panic("tcp_init"); 417 #undef TCP_MINPROTOHDR 418 419 ISN_LOCK_INIT(); 420 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 421 SHUTDOWN_PRI_DEFAULT); 422 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 423 EVENTHANDLER_PRI_ANY); 424 } 425 426 #ifdef VIMAGE 427 void 428 tcp_destroy(void) 429 { 430 431 tcp_reass_destroy(); 432 tcp_hc_destroy(); 433 syncache_destroy(); 434 tcp_tw_destroy(); 435 in_pcbinfo_destroy(&V_tcbinfo); 436 uma_zdestroy(V_sack_hole_zone); 437 uma_zdestroy(V_tcpcb_zone); 438 } 439 #endif 440 441 void 442 tcp_fini(void *xtp) 443 { 444 445 } 446 447 /* 448 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 449 * tcp_template used to store this data in mbufs, but we now recopy it out 450 * of the tcpcb each time to conserve mbufs. 451 */ 452 void 453 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 454 { 455 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 456 457 INP_WLOCK_ASSERT(inp); 458 459 #ifdef INET6 460 if ((inp->inp_vflag & INP_IPV6) != 0) { 461 struct ip6_hdr *ip6; 462 463 ip6 = (struct ip6_hdr *)ip_ptr; 464 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 465 (inp->inp_flow & IPV6_FLOWINFO_MASK); 466 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 467 (IPV6_VERSION & IPV6_VERSION_MASK); 468 ip6->ip6_nxt = IPPROTO_TCP; 469 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 470 ip6->ip6_src = inp->in6p_laddr; 471 ip6->ip6_dst = inp->in6p_faddr; 472 } 473 #endif /* INET6 */ 474 #if defined(INET6) && defined(INET) 475 else 476 #endif 477 #ifdef INET 478 { 479 struct ip *ip; 480 481 ip = (struct ip *)ip_ptr; 482 ip->ip_v = IPVERSION; 483 ip->ip_hl = 5; 484 ip->ip_tos = inp->inp_ip_tos; 485 ip->ip_len = 0; 486 ip->ip_id = 0; 487 ip->ip_off = 0; 488 ip->ip_ttl = inp->inp_ip_ttl; 489 ip->ip_sum = 0; 490 ip->ip_p = IPPROTO_TCP; 491 ip->ip_src = inp->inp_laddr; 492 ip->ip_dst = inp->inp_faddr; 493 } 494 #endif /* INET */ 495 th->th_sport = inp->inp_lport; 496 th->th_dport = inp->inp_fport; 497 th->th_seq = 0; 498 th->th_ack = 0; 499 th->th_x2 = 0; 500 th->th_off = 5; 501 th->th_flags = 0; 502 th->th_win = 0; 503 th->th_urp = 0; 504 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 505 } 506 507 /* 508 * Create template to be used to send tcp packets on a connection. 509 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 510 * use for this function is in keepalives, which use tcp_respond. 511 */ 512 struct tcptemp * 513 tcpip_maketemplate(struct inpcb *inp) 514 { 515 struct tcptemp *t; 516 517 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 518 if (t == NULL) 519 return (NULL); 520 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 521 return (t); 522 } 523 524 /* 525 * Send a single message to the TCP at address specified by 526 * the given TCP/IP header. If m == NULL, then we make a copy 527 * of the tcpiphdr at ti and send directly to the addressed host. 528 * This is used to force keep alive messages out using the TCP 529 * template for a connection. If flags are given then we send 530 * a message back to the TCP which originated the * segment ti, 531 * and discard the mbuf containing it and any other attached mbufs. 532 * 533 * In any case the ack and sequence number of the transmitted 534 * segment are as specified by the parameters. 535 * 536 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 537 */ 538 void 539 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 540 tcp_seq ack, tcp_seq seq, int flags) 541 { 542 int tlen; 543 int win = 0; 544 struct ip *ip; 545 struct tcphdr *nth; 546 #ifdef INET6 547 struct ip6_hdr *ip6; 548 int isipv6; 549 #endif /* INET6 */ 550 int ipflags = 0; 551 struct inpcb *inp; 552 553 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 554 555 #ifdef INET6 556 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 557 ip6 = ipgen; 558 #endif /* INET6 */ 559 ip = ipgen; 560 561 if (tp != NULL) { 562 inp = tp->t_inpcb; 563 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 564 INP_WLOCK_ASSERT(inp); 565 } else 566 inp = NULL; 567 568 if (tp != NULL) { 569 if (!(flags & TH_RST)) { 570 win = sbspace(&inp->inp_socket->so_rcv); 571 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 572 win = (long)TCP_MAXWIN << tp->rcv_scale; 573 } 574 } 575 if (m == NULL) { 576 m = m_gethdr(M_NOWAIT, MT_DATA); 577 if (m == NULL) 578 return; 579 tlen = 0; 580 m->m_data += max_linkhdr; 581 #ifdef INET6 582 if (isipv6) { 583 bcopy((caddr_t)ip6, mtod(m, caddr_t), 584 sizeof(struct ip6_hdr)); 585 ip6 = mtod(m, struct ip6_hdr *); 586 nth = (struct tcphdr *)(ip6 + 1); 587 } else 588 #endif /* INET6 */ 589 { 590 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 591 ip = mtod(m, struct ip *); 592 nth = (struct tcphdr *)(ip + 1); 593 } 594 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 595 flags = TH_ACK; 596 } else { 597 /* 598 * reuse the mbuf. 599 * XXX MRT We inherrit the FIB, which is lucky. 600 */ 601 m_freem(m->m_next); 602 m->m_next = NULL; 603 m->m_data = (caddr_t)ipgen; 604 /* m_len is set later */ 605 tlen = 0; 606 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 607 #ifdef INET6 608 if (isipv6) { 609 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 610 nth = (struct tcphdr *)(ip6 + 1); 611 } else 612 #endif /* INET6 */ 613 { 614 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 615 nth = (struct tcphdr *)(ip + 1); 616 } 617 if (th != nth) { 618 /* 619 * this is usually a case when an extension header 620 * exists between the IPv6 header and the 621 * TCP header. 622 */ 623 nth->th_sport = th->th_sport; 624 nth->th_dport = th->th_dport; 625 } 626 xchg(nth->th_dport, nth->th_sport, uint16_t); 627 #undef xchg 628 } 629 #ifdef INET6 630 if (isipv6) { 631 ip6->ip6_flow = 0; 632 ip6->ip6_vfc = IPV6_VERSION; 633 ip6->ip6_nxt = IPPROTO_TCP; 634 ip6->ip6_plen = 0; /* Set in ip6_output(). */ 635 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 636 } 637 #endif 638 #if defined(INET) && defined(INET6) 639 else 640 #endif 641 #ifdef INET 642 { 643 tlen += sizeof (struct tcpiphdr); 644 ip->ip_len = htons(tlen); 645 ip->ip_ttl = V_ip_defttl; 646 if (V_path_mtu_discovery) 647 ip->ip_off |= htons(IP_DF); 648 } 649 #endif 650 m->m_len = tlen; 651 m->m_pkthdr.len = tlen; 652 m->m_pkthdr.rcvif = NULL; 653 #ifdef MAC 654 if (inp != NULL) { 655 /* 656 * Packet is associated with a socket, so allow the 657 * label of the response to reflect the socket label. 658 */ 659 INP_WLOCK_ASSERT(inp); 660 mac_inpcb_create_mbuf(inp, m); 661 } else { 662 /* 663 * Packet is not associated with a socket, so possibly 664 * update the label in place. 665 */ 666 mac_netinet_tcp_reply(m); 667 } 668 #endif 669 nth->th_seq = htonl(seq); 670 nth->th_ack = htonl(ack); 671 nth->th_x2 = 0; 672 nth->th_off = sizeof (struct tcphdr) >> 2; 673 nth->th_flags = flags; 674 if (tp != NULL) 675 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 676 else 677 nth->th_win = htons((u_short)win); 678 nth->th_urp = 0; 679 680 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 681 #ifdef INET6 682 if (isipv6) { 683 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 684 nth->th_sum = in6_cksum_pseudo(ip6, 685 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 686 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 687 NULL, NULL); 688 } 689 #endif /* INET6 */ 690 #if defined(INET6) && defined(INET) 691 else 692 #endif 693 #ifdef INET 694 { 695 m->m_pkthdr.csum_flags = CSUM_TCP; 696 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 697 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 698 } 699 #endif /* INET */ 700 #ifdef TCPDEBUG 701 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 702 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 703 #endif 704 #ifdef INET6 705 if (isipv6) 706 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 707 #endif /* INET6 */ 708 #if defined(INET) && defined(INET6) 709 else 710 #endif 711 #ifdef INET 712 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 713 #endif 714 } 715 716 /* 717 * Create a new TCP control block, making an 718 * empty reassembly queue and hooking it to the argument 719 * protocol control block. The `inp' parameter must have 720 * come from the zone allocator set up in tcp_init(). 721 */ 722 struct tcpcb * 723 tcp_newtcpcb(struct inpcb *inp) 724 { 725 struct tcpcb_mem *tm; 726 struct tcpcb *tp; 727 #ifdef INET6 728 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 729 #endif /* INET6 */ 730 731 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 732 if (tm == NULL) 733 return (NULL); 734 tp = &tm->tcb; 735 736 /* Initialise cc_var struct for this tcpcb. */ 737 tp->ccv = &tm->ccv; 738 tp->ccv->type = IPPROTO_TCP; 739 tp->ccv->ccvc.tcp = tp; 740 741 /* 742 * Use the current system default CC algorithm. 743 */ 744 CC_LIST_RLOCK(); 745 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 746 CC_ALGO(tp) = CC_DEFAULT(); 747 CC_LIST_RUNLOCK(); 748 749 if (CC_ALGO(tp)->cb_init != NULL) 750 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 751 uma_zfree(V_tcpcb_zone, tm); 752 return (NULL); 753 } 754 755 tp->osd = &tm->osd; 756 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 757 uma_zfree(V_tcpcb_zone, tm); 758 return (NULL); 759 } 760 761 #ifdef VIMAGE 762 tp->t_vnet = inp->inp_vnet; 763 #endif 764 tp->t_timers = &tm->tt; 765 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 766 tp->t_maxseg = tp->t_maxopd = 767 #ifdef INET6 768 isipv6 ? V_tcp_v6mssdflt : 769 #endif /* INET6 */ 770 V_tcp_mssdflt; 771 772 /* Set up our timeouts. */ 773 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 774 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 775 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 776 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 777 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 778 779 if (V_tcp_do_rfc1323) 780 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 781 if (V_tcp_do_sack) 782 tp->t_flags |= TF_SACK_PERMIT; 783 TAILQ_INIT(&tp->snd_holes); 784 tp->t_inpcb = inp; /* XXX */ 785 /* 786 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 787 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 788 * reasonable initial retransmit time. 789 */ 790 tp->t_srtt = TCPTV_SRTTBASE; 791 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 792 tp->t_rttmin = tcp_rexmit_min; 793 tp->t_rxtcur = TCPTV_RTOBASE; 794 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 795 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 796 tp->t_rcvtime = ticks; 797 /* 798 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 799 * because the socket may be bound to an IPv6 wildcard address, 800 * which may match an IPv4-mapped IPv6 address. 801 */ 802 inp->inp_ip_ttl = V_ip_defttl; 803 inp->inp_ppcb = tp; 804 return (tp); /* XXX */ 805 } 806 807 /* 808 * Switch the congestion control algorithm back to NewReno for any active 809 * control blocks using an algorithm which is about to go away. 810 * This ensures the CC framework can allow the unload to proceed without leaving 811 * any dangling pointers which would trigger a panic. 812 * Returning non-zero would inform the CC framework that something went wrong 813 * and it would be unsafe to allow the unload to proceed. However, there is no 814 * way for this to occur with this implementation so we always return zero. 815 */ 816 int 817 tcp_ccalgounload(struct cc_algo *unload_algo) 818 { 819 struct cc_algo *tmpalgo; 820 struct inpcb *inp; 821 struct tcpcb *tp; 822 VNET_ITERATOR_DECL(vnet_iter); 823 824 /* 825 * Check all active control blocks across all network stacks and change 826 * any that are using "unload_algo" back to NewReno. If "unload_algo" 827 * requires cleanup code to be run, call it. 828 */ 829 VNET_LIST_RLOCK(); 830 VNET_FOREACH(vnet_iter) { 831 CURVNET_SET(vnet_iter); 832 INP_INFO_RLOCK(&V_tcbinfo); 833 /* 834 * New connections already part way through being initialised 835 * with the CC algo we're removing will not race with this code 836 * because the INP_INFO_WLOCK is held during initialisation. We 837 * therefore don't enter the loop below until the connection 838 * list has stabilised. 839 */ 840 LIST_FOREACH(inp, &V_tcb, inp_list) { 841 INP_WLOCK(inp); 842 /* Important to skip tcptw structs. */ 843 if (!(inp->inp_flags & INP_TIMEWAIT) && 844 (tp = intotcpcb(inp)) != NULL) { 845 /* 846 * By holding INP_WLOCK here, we are assured 847 * that the connection is not currently 848 * executing inside the CC module's functions 849 * i.e. it is safe to make the switch back to 850 * NewReno. 851 */ 852 if (CC_ALGO(tp) == unload_algo) { 853 tmpalgo = CC_ALGO(tp); 854 /* NewReno does not require any init. */ 855 CC_ALGO(tp) = &newreno_cc_algo; 856 if (tmpalgo->cb_destroy != NULL) 857 tmpalgo->cb_destroy(tp->ccv); 858 } 859 } 860 INP_WUNLOCK(inp); 861 } 862 INP_INFO_RUNLOCK(&V_tcbinfo); 863 CURVNET_RESTORE(); 864 } 865 VNET_LIST_RUNLOCK(); 866 867 return (0); 868 } 869 870 /* 871 * Drop a TCP connection, reporting 872 * the specified error. If connection is synchronized, 873 * then send a RST to peer. 874 */ 875 struct tcpcb * 876 tcp_drop(struct tcpcb *tp, int errno) 877 { 878 struct socket *so = tp->t_inpcb->inp_socket; 879 880 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 881 INP_WLOCK_ASSERT(tp->t_inpcb); 882 883 if (TCPS_HAVERCVDSYN(tp->t_state)) { 884 tp->t_state = TCPS_CLOSED; 885 (void) tcp_output(tp); 886 TCPSTAT_INC(tcps_drops); 887 } else 888 TCPSTAT_INC(tcps_conndrops); 889 if (errno == ETIMEDOUT && tp->t_softerror) 890 errno = tp->t_softerror; 891 so->so_error = errno; 892 return (tcp_close(tp)); 893 } 894 895 void 896 tcp_discardcb(struct tcpcb *tp) 897 { 898 struct inpcb *inp = tp->t_inpcb; 899 struct socket *so = inp->inp_socket; 900 #ifdef INET6 901 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 902 #endif /* INET6 */ 903 904 INP_WLOCK_ASSERT(inp); 905 906 /* 907 * Make sure that all of our timers are stopped before we delete the 908 * PCB. 909 * 910 * XXXRW: Really, we would like to use callout_drain() here in order 911 * to avoid races experienced in tcp_timer.c where a timer is already 912 * executing at this point. However, we can't, both because we're 913 * running in a context where we can't sleep, and also because we 914 * hold locks required by the timers. What we instead need to do is 915 * test to see if callout_drain() is required, and if so, defer some 916 * portion of the remainder of tcp_discardcb() to an asynchronous 917 * context that can callout_drain() and then continue. Some care 918 * will be required to ensure that no further processing takes place 919 * on the tcpcb, even though it hasn't been freed (a flag?). 920 */ 921 callout_stop(&tp->t_timers->tt_rexmt); 922 callout_stop(&tp->t_timers->tt_persist); 923 callout_stop(&tp->t_timers->tt_keep); 924 callout_stop(&tp->t_timers->tt_2msl); 925 callout_stop(&tp->t_timers->tt_delack); 926 927 /* 928 * If we got enough samples through the srtt filter, 929 * save the rtt and rttvar in the routing entry. 930 * 'Enough' is arbitrarily defined as 4 rtt samples. 931 * 4 samples is enough for the srtt filter to converge 932 * to within enough % of the correct value; fewer samples 933 * and we could save a bogus rtt. The danger is not high 934 * as tcp quickly recovers from everything. 935 * XXX: Works very well but needs some more statistics! 936 */ 937 if (tp->t_rttupdated >= 4) { 938 struct hc_metrics_lite metrics; 939 u_long ssthresh; 940 941 bzero(&metrics, sizeof(metrics)); 942 /* 943 * Update the ssthresh always when the conditions below 944 * are satisfied. This gives us better new start value 945 * for the congestion avoidance for new connections. 946 * ssthresh is only set if packet loss occured on a session. 947 * 948 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 949 * being torn down. Ideally this code would not use 'so'. 950 */ 951 ssthresh = tp->snd_ssthresh; 952 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 953 /* 954 * convert the limit from user data bytes to 955 * packets then to packet data bytes. 956 */ 957 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 958 if (ssthresh < 2) 959 ssthresh = 2; 960 ssthresh *= (u_long)(tp->t_maxseg + 961 #ifdef INET6 962 (isipv6 ? sizeof (struct ip6_hdr) + 963 sizeof (struct tcphdr) : 964 #endif 965 sizeof (struct tcpiphdr) 966 #ifdef INET6 967 ) 968 #endif 969 ); 970 } else 971 ssthresh = 0; 972 metrics.rmx_ssthresh = ssthresh; 973 974 metrics.rmx_rtt = tp->t_srtt; 975 metrics.rmx_rttvar = tp->t_rttvar; 976 metrics.rmx_cwnd = tp->snd_cwnd; 977 metrics.rmx_sendpipe = 0; 978 metrics.rmx_recvpipe = 0; 979 980 tcp_hc_update(&inp->inp_inc, &metrics); 981 } 982 983 /* free the reassembly queue, if any */ 984 tcp_reass_flush(tp); 985 986 #ifdef TCP_OFFLOAD 987 /* Disconnect offload device, if any. */ 988 if (tp->t_flags & TF_TOE) 989 tcp_offload_detach(tp); 990 #endif 991 992 tcp_free_sackholes(tp); 993 994 /* Allow the CC algorithm to clean up after itself. */ 995 if (CC_ALGO(tp)->cb_destroy != NULL) 996 CC_ALGO(tp)->cb_destroy(tp->ccv); 997 998 khelp_destroy_osd(tp->osd); 999 1000 CC_ALGO(tp) = NULL; 1001 inp->inp_ppcb = NULL; 1002 tp->t_inpcb = NULL; 1003 uma_zfree(V_tcpcb_zone, tp); 1004 } 1005 1006 /* 1007 * Attempt to close a TCP control block, marking it as dropped, and freeing 1008 * the socket if we hold the only reference. 1009 */ 1010 struct tcpcb * 1011 tcp_close(struct tcpcb *tp) 1012 { 1013 struct inpcb *inp = tp->t_inpcb; 1014 struct socket *so; 1015 1016 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1017 INP_WLOCK_ASSERT(inp); 1018 1019 #ifdef TCP_OFFLOAD 1020 if (tp->t_state == TCPS_LISTEN) 1021 tcp_offload_listen_stop(tp); 1022 #endif 1023 in_pcbdrop(inp); 1024 TCPSTAT_INC(tcps_closed); 1025 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1026 so = inp->inp_socket; 1027 soisdisconnected(so); 1028 if (inp->inp_flags & INP_SOCKREF) { 1029 KASSERT(so->so_state & SS_PROTOREF, 1030 ("tcp_close: !SS_PROTOREF")); 1031 inp->inp_flags &= ~INP_SOCKREF; 1032 INP_WUNLOCK(inp); 1033 ACCEPT_LOCK(); 1034 SOCK_LOCK(so); 1035 so->so_state &= ~SS_PROTOREF; 1036 sofree(so); 1037 return (NULL); 1038 } 1039 return (tp); 1040 } 1041 1042 void 1043 tcp_drain(void) 1044 { 1045 VNET_ITERATOR_DECL(vnet_iter); 1046 1047 if (!do_tcpdrain) 1048 return; 1049 1050 VNET_LIST_RLOCK_NOSLEEP(); 1051 VNET_FOREACH(vnet_iter) { 1052 CURVNET_SET(vnet_iter); 1053 struct inpcb *inpb; 1054 struct tcpcb *tcpb; 1055 1056 /* 1057 * Walk the tcpbs, if existing, and flush the reassembly queue, 1058 * if there is one... 1059 * XXX: The "Net/3" implementation doesn't imply that the TCP 1060 * reassembly queue should be flushed, but in a situation 1061 * where we're really low on mbufs, this is potentially 1062 * usefull. 1063 */ 1064 INP_INFO_RLOCK(&V_tcbinfo); 1065 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1066 if (inpb->inp_flags & INP_TIMEWAIT) 1067 continue; 1068 INP_WLOCK(inpb); 1069 if ((tcpb = intotcpcb(inpb)) != NULL) { 1070 tcp_reass_flush(tcpb); 1071 tcp_clean_sackreport(tcpb); 1072 } 1073 INP_WUNLOCK(inpb); 1074 } 1075 INP_INFO_RUNLOCK(&V_tcbinfo); 1076 CURVNET_RESTORE(); 1077 } 1078 VNET_LIST_RUNLOCK_NOSLEEP(); 1079 } 1080 1081 /* 1082 * Notify a tcp user of an asynchronous error; 1083 * store error as soft error, but wake up user 1084 * (for now, won't do anything until can select for soft error). 1085 * 1086 * Do not wake up user since there currently is no mechanism for 1087 * reporting soft errors (yet - a kqueue filter may be added). 1088 */ 1089 static struct inpcb * 1090 tcp_notify(struct inpcb *inp, int error) 1091 { 1092 struct tcpcb *tp; 1093 1094 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1095 INP_WLOCK_ASSERT(inp); 1096 1097 if ((inp->inp_flags & INP_TIMEWAIT) || 1098 (inp->inp_flags & INP_DROPPED)) 1099 return (inp); 1100 1101 tp = intotcpcb(inp); 1102 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1103 1104 /* 1105 * Ignore some errors if we are hooked up. 1106 * If connection hasn't completed, has retransmitted several times, 1107 * and receives a second error, give up now. This is better 1108 * than waiting a long time to establish a connection that 1109 * can never complete. 1110 */ 1111 if (tp->t_state == TCPS_ESTABLISHED && 1112 (error == EHOSTUNREACH || error == ENETUNREACH || 1113 error == EHOSTDOWN)) { 1114 return (inp); 1115 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1116 tp->t_softerror) { 1117 tp = tcp_drop(tp, error); 1118 if (tp != NULL) 1119 return (inp); 1120 else 1121 return (NULL); 1122 } else { 1123 tp->t_softerror = error; 1124 return (inp); 1125 } 1126 #if 0 1127 wakeup( &so->so_timeo); 1128 sorwakeup(so); 1129 sowwakeup(so); 1130 #endif 1131 } 1132 1133 static int 1134 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1135 { 1136 int error, i, m, n, pcb_count; 1137 struct inpcb *inp, **inp_list; 1138 inp_gen_t gencnt; 1139 struct xinpgen xig; 1140 1141 /* 1142 * The process of preparing the TCB list is too time-consuming and 1143 * resource-intensive to repeat twice on every request. 1144 */ 1145 if (req->oldptr == NULL) { 1146 n = V_tcbinfo.ipi_count + syncache_pcbcount(); 1147 n += imax(n / 8, 10); 1148 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1149 return (0); 1150 } 1151 1152 if (req->newptr != NULL) 1153 return (EPERM); 1154 1155 /* 1156 * OK, now we're committed to doing something. 1157 */ 1158 INP_INFO_RLOCK(&V_tcbinfo); 1159 gencnt = V_tcbinfo.ipi_gencnt; 1160 n = V_tcbinfo.ipi_count; 1161 INP_INFO_RUNLOCK(&V_tcbinfo); 1162 1163 m = syncache_pcbcount(); 1164 1165 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1166 + (n + m) * sizeof(struct xtcpcb)); 1167 if (error != 0) 1168 return (error); 1169 1170 xig.xig_len = sizeof xig; 1171 xig.xig_count = n + m; 1172 xig.xig_gen = gencnt; 1173 xig.xig_sogen = so_gencnt; 1174 error = SYSCTL_OUT(req, &xig, sizeof xig); 1175 if (error) 1176 return (error); 1177 1178 error = syncache_pcblist(req, m, &pcb_count); 1179 if (error) 1180 return (error); 1181 1182 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1183 if (inp_list == NULL) 1184 return (ENOMEM); 1185 1186 INP_INFO_RLOCK(&V_tcbinfo); 1187 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1188 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1189 INP_WLOCK(inp); 1190 if (inp->inp_gencnt <= gencnt) { 1191 /* 1192 * XXX: This use of cr_cansee(), introduced with 1193 * TCP state changes, is not quite right, but for 1194 * now, better than nothing. 1195 */ 1196 if (inp->inp_flags & INP_TIMEWAIT) { 1197 if (intotw(inp) != NULL) 1198 error = cr_cansee(req->td->td_ucred, 1199 intotw(inp)->tw_cred); 1200 else 1201 error = EINVAL; /* Skip this inp. */ 1202 } else 1203 error = cr_canseeinpcb(req->td->td_ucred, inp); 1204 if (error == 0) { 1205 in_pcbref(inp); 1206 inp_list[i++] = inp; 1207 } 1208 } 1209 INP_WUNLOCK(inp); 1210 } 1211 INP_INFO_RUNLOCK(&V_tcbinfo); 1212 n = i; 1213 1214 error = 0; 1215 for (i = 0; i < n; i++) { 1216 inp = inp_list[i]; 1217 INP_RLOCK(inp); 1218 if (inp->inp_gencnt <= gencnt) { 1219 struct xtcpcb xt; 1220 void *inp_ppcb; 1221 1222 bzero(&xt, sizeof(xt)); 1223 xt.xt_len = sizeof xt; 1224 /* XXX should avoid extra copy */ 1225 bcopy(inp, &xt.xt_inp, sizeof *inp); 1226 inp_ppcb = inp->inp_ppcb; 1227 if (inp_ppcb == NULL) 1228 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1229 else if (inp->inp_flags & INP_TIMEWAIT) { 1230 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1231 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1232 } else { 1233 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1234 if (xt.xt_tp.t_timers) 1235 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1236 } 1237 if (inp->inp_socket != NULL) 1238 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1239 else { 1240 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1241 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1242 } 1243 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1244 INP_RUNLOCK(inp); 1245 error = SYSCTL_OUT(req, &xt, sizeof xt); 1246 } else 1247 INP_RUNLOCK(inp); 1248 } 1249 INP_INFO_WLOCK(&V_tcbinfo); 1250 for (i = 0; i < n; i++) { 1251 inp = inp_list[i]; 1252 INP_RLOCK(inp); 1253 if (!in_pcbrele_rlocked(inp)) 1254 INP_RUNLOCK(inp); 1255 } 1256 INP_INFO_WUNLOCK(&V_tcbinfo); 1257 1258 if (!error) { 1259 /* 1260 * Give the user an updated idea of our state. 1261 * If the generation differs from what we told 1262 * her before, she knows that something happened 1263 * while we were processing this request, and it 1264 * might be necessary to retry. 1265 */ 1266 INP_INFO_RLOCK(&V_tcbinfo); 1267 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1268 xig.xig_sogen = so_gencnt; 1269 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1270 INP_INFO_RUNLOCK(&V_tcbinfo); 1271 error = SYSCTL_OUT(req, &xig, sizeof xig); 1272 } 1273 free(inp_list, M_TEMP); 1274 return (error); 1275 } 1276 1277 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1278 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1279 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1280 1281 #ifdef INET 1282 static int 1283 tcp_getcred(SYSCTL_HANDLER_ARGS) 1284 { 1285 struct xucred xuc; 1286 struct sockaddr_in addrs[2]; 1287 struct inpcb *inp; 1288 int error; 1289 1290 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1291 if (error) 1292 return (error); 1293 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1294 if (error) 1295 return (error); 1296 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1297 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1298 if (inp != NULL) { 1299 if (inp->inp_socket == NULL) 1300 error = ENOENT; 1301 if (error == 0) 1302 error = cr_canseeinpcb(req->td->td_ucred, inp); 1303 if (error == 0) 1304 cru2x(inp->inp_cred, &xuc); 1305 INP_RUNLOCK(inp); 1306 } else 1307 error = ENOENT; 1308 if (error == 0) 1309 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1310 return (error); 1311 } 1312 1313 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1314 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1315 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1316 #endif /* INET */ 1317 1318 #ifdef INET6 1319 static int 1320 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1321 { 1322 struct xucred xuc; 1323 struct sockaddr_in6 addrs[2]; 1324 struct inpcb *inp; 1325 int error; 1326 #ifdef INET 1327 int mapped = 0; 1328 #endif 1329 1330 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1331 if (error) 1332 return (error); 1333 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1334 if (error) 1335 return (error); 1336 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1337 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1338 return (error); 1339 } 1340 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1341 #ifdef INET 1342 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1343 mapped = 1; 1344 else 1345 #endif 1346 return (EINVAL); 1347 } 1348 1349 #ifdef INET 1350 if (mapped == 1) 1351 inp = in_pcblookup(&V_tcbinfo, 1352 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1353 addrs[1].sin6_port, 1354 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1355 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1356 else 1357 #endif 1358 inp = in6_pcblookup(&V_tcbinfo, 1359 &addrs[1].sin6_addr, addrs[1].sin6_port, 1360 &addrs[0].sin6_addr, addrs[0].sin6_port, 1361 INPLOOKUP_RLOCKPCB, NULL); 1362 if (inp != NULL) { 1363 if (inp->inp_socket == NULL) 1364 error = ENOENT; 1365 if (error == 0) 1366 error = cr_canseeinpcb(req->td->td_ucred, inp); 1367 if (error == 0) 1368 cru2x(inp->inp_cred, &xuc); 1369 INP_RUNLOCK(inp); 1370 } else 1371 error = ENOENT; 1372 if (error == 0) 1373 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1374 return (error); 1375 } 1376 1377 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1378 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1379 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1380 #endif /* INET6 */ 1381 1382 1383 #ifdef INET 1384 void 1385 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1386 { 1387 struct ip *ip = vip; 1388 struct tcphdr *th; 1389 struct in_addr faddr; 1390 struct inpcb *inp; 1391 struct tcpcb *tp; 1392 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1393 struct icmp *icp; 1394 struct in_conninfo inc; 1395 tcp_seq icmp_tcp_seq; 1396 int mtu; 1397 1398 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1399 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1400 return; 1401 1402 if (cmd == PRC_MSGSIZE) 1403 notify = tcp_mtudisc_notify; 1404 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1405 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1406 notify = tcp_drop_syn_sent; 1407 /* 1408 * Redirects don't need to be handled up here. 1409 */ 1410 else if (PRC_IS_REDIRECT(cmd)) 1411 return; 1412 /* 1413 * Source quench is depreciated. 1414 */ 1415 else if (cmd == PRC_QUENCH) 1416 return; 1417 /* 1418 * Hostdead is ugly because it goes linearly through all PCBs. 1419 * XXX: We never get this from ICMP, otherwise it makes an 1420 * excellent DoS attack on machines with many connections. 1421 */ 1422 else if (cmd == PRC_HOSTDEAD) 1423 ip = NULL; 1424 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1425 return; 1426 if (ip != NULL) { 1427 icp = (struct icmp *)((caddr_t)ip 1428 - offsetof(struct icmp, icmp_ip)); 1429 th = (struct tcphdr *)((caddr_t)ip 1430 + (ip->ip_hl << 2)); 1431 INP_INFO_WLOCK(&V_tcbinfo); 1432 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, 1433 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1434 if (inp != NULL) { 1435 if (!(inp->inp_flags & INP_TIMEWAIT) && 1436 !(inp->inp_flags & INP_DROPPED) && 1437 !(inp->inp_socket == NULL)) { 1438 icmp_tcp_seq = htonl(th->th_seq); 1439 tp = intotcpcb(inp); 1440 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1441 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1442 if (cmd == PRC_MSGSIZE) { 1443 /* 1444 * MTU discovery: 1445 * If we got a needfrag set the MTU 1446 * in the route to the suggested new 1447 * value (if given) and then notify. 1448 */ 1449 bzero(&inc, sizeof(inc)); 1450 inc.inc_faddr = faddr; 1451 inc.inc_fibnum = 1452 inp->inp_inc.inc_fibnum; 1453 1454 mtu = ntohs(icp->icmp_nextmtu); 1455 /* 1456 * If no alternative MTU was 1457 * proposed, try the next smaller 1458 * one. 1459 */ 1460 if (!mtu) 1461 mtu = ip_next_mtu( 1462 ntohs(ip->ip_len), 1); 1463 if (mtu < V_tcp_minmss 1464 + sizeof(struct tcpiphdr)) 1465 mtu = V_tcp_minmss 1466 + sizeof(struct tcpiphdr); 1467 /* 1468 * Only cache the MTU if it 1469 * is smaller than the interface 1470 * or route MTU. tcp_mtudisc() 1471 * will do right thing by itself. 1472 */ 1473 if (mtu <= tcp_maxmtu(&inc, NULL)) 1474 tcp_hc_updatemtu(&inc, mtu); 1475 tcp_mtudisc(inp, mtu); 1476 } else 1477 inp = (*notify)(inp, 1478 inetctlerrmap[cmd]); 1479 } 1480 } 1481 if (inp != NULL) 1482 INP_WUNLOCK(inp); 1483 } else { 1484 bzero(&inc, sizeof(inc)); 1485 inc.inc_fport = th->th_dport; 1486 inc.inc_lport = th->th_sport; 1487 inc.inc_faddr = faddr; 1488 inc.inc_laddr = ip->ip_src; 1489 syncache_unreach(&inc, th); 1490 } 1491 INP_INFO_WUNLOCK(&V_tcbinfo); 1492 } else 1493 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1494 } 1495 #endif /* INET */ 1496 1497 #ifdef INET6 1498 void 1499 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1500 { 1501 struct tcphdr th; 1502 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1503 struct ip6_hdr *ip6; 1504 struct mbuf *m; 1505 struct ip6ctlparam *ip6cp = NULL; 1506 const struct sockaddr_in6 *sa6_src = NULL; 1507 int off; 1508 struct tcp_portonly { 1509 u_int16_t th_sport; 1510 u_int16_t th_dport; 1511 } *thp; 1512 1513 if (sa->sa_family != AF_INET6 || 1514 sa->sa_len != sizeof(struct sockaddr_in6)) 1515 return; 1516 1517 if (cmd == PRC_MSGSIZE) 1518 notify = tcp_mtudisc_notify; 1519 else if (!PRC_IS_REDIRECT(cmd) && 1520 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1521 return; 1522 /* Source quench is depreciated. */ 1523 else if (cmd == PRC_QUENCH) 1524 return; 1525 1526 /* if the parameter is from icmp6, decode it. */ 1527 if (d != NULL) { 1528 ip6cp = (struct ip6ctlparam *)d; 1529 m = ip6cp->ip6c_m; 1530 ip6 = ip6cp->ip6c_ip6; 1531 off = ip6cp->ip6c_off; 1532 sa6_src = ip6cp->ip6c_src; 1533 } else { 1534 m = NULL; 1535 ip6 = NULL; 1536 off = 0; /* fool gcc */ 1537 sa6_src = &sa6_any; 1538 } 1539 1540 if (ip6 != NULL) { 1541 struct in_conninfo inc; 1542 /* 1543 * XXX: We assume that when IPV6 is non NULL, 1544 * M and OFF are valid. 1545 */ 1546 1547 /* check if we can safely examine src and dst ports */ 1548 if (m->m_pkthdr.len < off + sizeof(*thp)) 1549 return; 1550 1551 bzero(&th, sizeof(th)); 1552 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1553 1554 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1555 (struct sockaddr *)ip6cp->ip6c_src, 1556 th.th_sport, cmd, NULL, notify); 1557 1558 bzero(&inc, sizeof(inc)); 1559 inc.inc_fport = th.th_dport; 1560 inc.inc_lport = th.th_sport; 1561 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1562 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1563 inc.inc_flags |= INC_ISIPV6; 1564 INP_INFO_WLOCK(&V_tcbinfo); 1565 syncache_unreach(&inc, &th); 1566 INP_INFO_WUNLOCK(&V_tcbinfo); 1567 } else 1568 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1569 0, cmd, NULL, notify); 1570 } 1571 #endif /* INET6 */ 1572 1573 1574 /* 1575 * Following is where TCP initial sequence number generation occurs. 1576 * 1577 * There are two places where we must use initial sequence numbers: 1578 * 1. In SYN-ACK packets. 1579 * 2. In SYN packets. 1580 * 1581 * All ISNs for SYN-ACK packets are generated by the syncache. See 1582 * tcp_syncache.c for details. 1583 * 1584 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1585 * depends on this property. In addition, these ISNs should be 1586 * unguessable so as to prevent connection hijacking. To satisfy 1587 * the requirements of this situation, the algorithm outlined in 1588 * RFC 1948 is used, with only small modifications. 1589 * 1590 * Implementation details: 1591 * 1592 * Time is based off the system timer, and is corrected so that it 1593 * increases by one megabyte per second. This allows for proper 1594 * recycling on high speed LANs while still leaving over an hour 1595 * before rollover. 1596 * 1597 * As reading the *exact* system time is too expensive to be done 1598 * whenever setting up a TCP connection, we increment the time 1599 * offset in two ways. First, a small random positive increment 1600 * is added to isn_offset for each connection that is set up. 1601 * Second, the function tcp_isn_tick fires once per clock tick 1602 * and increments isn_offset as necessary so that sequence numbers 1603 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1604 * random positive increments serve only to ensure that the same 1605 * exact sequence number is never sent out twice (as could otherwise 1606 * happen when a port is recycled in less than the system tick 1607 * interval.) 1608 * 1609 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1610 * between seeding of isn_secret. This is normally set to zero, 1611 * as reseeding should not be necessary. 1612 * 1613 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1614 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1615 * general, this means holding an exclusive (write) lock. 1616 */ 1617 1618 #define ISN_BYTES_PER_SECOND 1048576 1619 #define ISN_STATIC_INCREMENT 4096 1620 #define ISN_RANDOM_INCREMENT (4096 - 1) 1621 1622 static VNET_DEFINE(u_char, isn_secret[32]); 1623 static VNET_DEFINE(int, isn_last); 1624 static VNET_DEFINE(int, isn_last_reseed); 1625 static VNET_DEFINE(u_int32_t, isn_offset); 1626 static VNET_DEFINE(u_int32_t, isn_offset_old); 1627 1628 #define V_isn_secret VNET(isn_secret) 1629 #define V_isn_last VNET(isn_last) 1630 #define V_isn_last_reseed VNET(isn_last_reseed) 1631 #define V_isn_offset VNET(isn_offset) 1632 #define V_isn_offset_old VNET(isn_offset_old) 1633 1634 tcp_seq 1635 tcp_new_isn(struct tcpcb *tp) 1636 { 1637 MD5_CTX isn_ctx; 1638 u_int32_t md5_buffer[4]; 1639 tcp_seq new_isn; 1640 u_int32_t projected_offset; 1641 1642 INP_WLOCK_ASSERT(tp->t_inpcb); 1643 1644 ISN_LOCK(); 1645 /* Seed if this is the first use, reseed if requested. */ 1646 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1647 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1648 < (u_int)ticks))) { 1649 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1650 V_isn_last_reseed = ticks; 1651 } 1652 1653 /* Compute the md5 hash and return the ISN. */ 1654 MD5Init(&isn_ctx); 1655 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1656 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1657 #ifdef INET6 1658 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1659 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1660 sizeof(struct in6_addr)); 1661 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1662 sizeof(struct in6_addr)); 1663 } else 1664 #endif 1665 { 1666 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1667 sizeof(struct in_addr)); 1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1669 sizeof(struct in_addr)); 1670 } 1671 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1672 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1673 new_isn = (tcp_seq) md5_buffer[0]; 1674 V_isn_offset += ISN_STATIC_INCREMENT + 1675 (arc4random() & ISN_RANDOM_INCREMENT); 1676 if (ticks != V_isn_last) { 1677 projected_offset = V_isn_offset_old + 1678 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 1679 if (SEQ_GT(projected_offset, V_isn_offset)) 1680 V_isn_offset = projected_offset; 1681 V_isn_offset_old = V_isn_offset; 1682 V_isn_last = ticks; 1683 } 1684 new_isn += V_isn_offset; 1685 ISN_UNLOCK(); 1686 return (new_isn); 1687 } 1688 1689 /* 1690 * When a specific ICMP unreachable message is received and the 1691 * connection state is SYN-SENT, drop the connection. This behavior 1692 * is controlled by the icmp_may_rst sysctl. 1693 */ 1694 struct inpcb * 1695 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1696 { 1697 struct tcpcb *tp; 1698 1699 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1700 INP_WLOCK_ASSERT(inp); 1701 1702 if ((inp->inp_flags & INP_TIMEWAIT) || 1703 (inp->inp_flags & INP_DROPPED)) 1704 return (inp); 1705 1706 tp = intotcpcb(inp); 1707 if (tp->t_state != TCPS_SYN_SENT) 1708 return (inp); 1709 1710 tp = tcp_drop(tp, errno); 1711 if (tp != NULL) 1712 return (inp); 1713 else 1714 return (NULL); 1715 } 1716 1717 /* 1718 * When `need fragmentation' ICMP is received, update our idea of the MSS 1719 * based on the new value. Also nudge TCP to send something, since we 1720 * know the packet we just sent was dropped. 1721 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1722 */ 1723 static struct inpcb * 1724 tcp_mtudisc_notify(struct inpcb *inp, int error) 1725 { 1726 1727 return (tcp_mtudisc(inp, -1)); 1728 } 1729 1730 struct inpcb * 1731 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 1732 { 1733 struct tcpcb *tp; 1734 struct socket *so; 1735 1736 INP_WLOCK_ASSERT(inp); 1737 if ((inp->inp_flags & INP_TIMEWAIT) || 1738 (inp->inp_flags & INP_DROPPED)) 1739 return (inp); 1740 1741 tp = intotcpcb(inp); 1742 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1743 1744 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 1745 1746 so = inp->inp_socket; 1747 SOCKBUF_LOCK(&so->so_snd); 1748 /* If the mss is larger than the socket buffer, decrease the mss. */ 1749 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1750 tp->t_maxseg = so->so_snd.sb_hiwat; 1751 SOCKBUF_UNLOCK(&so->so_snd); 1752 1753 TCPSTAT_INC(tcps_mturesent); 1754 tp->t_rtttime = 0; 1755 tp->snd_nxt = tp->snd_una; 1756 tcp_free_sackholes(tp); 1757 tp->snd_recover = tp->snd_max; 1758 if (tp->t_flags & TF_SACK_PERMIT) 1759 EXIT_FASTRECOVERY(tp->t_flags); 1760 tcp_output(tp); 1761 return (inp); 1762 } 1763 1764 #ifdef INET 1765 /* 1766 * Look-up the routing entry to the peer of this inpcb. If no route 1767 * is found and it cannot be allocated, then return 0. This routine 1768 * is called by TCP routines that access the rmx structure and by 1769 * tcp_mss_update to get the peer/interface MTU. 1770 */ 1771 u_long 1772 tcp_maxmtu(struct in_conninfo *inc, int *flags) 1773 { 1774 struct route sro; 1775 struct sockaddr_in *dst; 1776 struct ifnet *ifp; 1777 u_long maxmtu = 0; 1778 1779 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1780 1781 bzero(&sro, sizeof(sro)); 1782 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1783 dst = (struct sockaddr_in *)&sro.ro_dst; 1784 dst->sin_family = AF_INET; 1785 dst->sin_len = sizeof(*dst); 1786 dst->sin_addr = inc->inc_faddr; 1787 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1788 } 1789 if (sro.ro_rt != NULL) { 1790 ifp = sro.ro_rt->rt_ifp; 1791 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1792 maxmtu = ifp->if_mtu; 1793 else 1794 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1795 1796 /* Report additional interface capabilities. */ 1797 if (flags != NULL) { 1798 if (ifp->if_capenable & IFCAP_TSO4 && 1799 ifp->if_hwassist & CSUM_TSO) 1800 *flags |= CSUM_TSO; 1801 } 1802 RTFREE(sro.ro_rt); 1803 } 1804 return (maxmtu); 1805 } 1806 #endif /* INET */ 1807 1808 #ifdef INET6 1809 u_long 1810 tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1811 { 1812 struct route_in6 sro6; 1813 struct ifnet *ifp; 1814 u_long maxmtu = 0; 1815 1816 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1817 1818 bzero(&sro6, sizeof(sro6)); 1819 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1820 sro6.ro_dst.sin6_family = AF_INET6; 1821 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1822 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1823 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum); 1824 } 1825 if (sro6.ro_rt != NULL) { 1826 ifp = sro6.ro_rt->rt_ifp; 1827 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1828 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1829 else 1830 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1831 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1832 1833 /* Report additional interface capabilities. */ 1834 if (flags != NULL) { 1835 if (ifp->if_capenable & IFCAP_TSO6 && 1836 ifp->if_hwassist & CSUM_TSO) 1837 *flags |= CSUM_TSO; 1838 } 1839 RTFREE(sro6.ro_rt); 1840 } 1841 1842 return (maxmtu); 1843 } 1844 #endif /* INET6 */ 1845 1846 #ifdef IPSEC 1847 /* compute ESP/AH header size for TCP, including outer IP header. */ 1848 size_t 1849 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1850 { 1851 struct inpcb *inp; 1852 struct mbuf *m; 1853 size_t hdrsiz; 1854 struct ip *ip; 1855 #ifdef INET6 1856 struct ip6_hdr *ip6; 1857 #endif 1858 struct tcphdr *th; 1859 1860 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1861 return (0); 1862 MGETHDR(m, M_NOWAIT, MT_DATA); 1863 if (!m) 1864 return (0); 1865 1866 #ifdef INET6 1867 if ((inp->inp_vflag & INP_IPV6) != 0) { 1868 ip6 = mtod(m, struct ip6_hdr *); 1869 th = (struct tcphdr *)(ip6 + 1); 1870 m->m_pkthdr.len = m->m_len = 1871 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1872 tcpip_fillheaders(inp, ip6, th); 1873 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1874 } else 1875 #endif /* INET6 */ 1876 { 1877 ip = mtod(m, struct ip *); 1878 th = (struct tcphdr *)(ip + 1); 1879 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1880 tcpip_fillheaders(inp, ip, th); 1881 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1882 } 1883 1884 m_free(m); 1885 return (hdrsiz); 1886 } 1887 #endif /* IPSEC */ 1888 1889 #ifdef TCP_SIGNATURE 1890 /* 1891 * Callback function invoked by m_apply() to digest TCP segment data 1892 * contained within an mbuf chain. 1893 */ 1894 static int 1895 tcp_signature_apply(void *fstate, void *data, u_int len) 1896 { 1897 1898 MD5Update(fstate, (u_char *)data, len); 1899 return (0); 1900 } 1901 1902 /* 1903 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1904 * 1905 * Parameters: 1906 * m pointer to head of mbuf chain 1907 * _unused 1908 * len length of TCP segment data, excluding options 1909 * optlen length of TCP segment options 1910 * buf pointer to storage for computed MD5 digest 1911 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1912 * 1913 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1914 * When called from tcp_input(), we can be sure that th_sum has been 1915 * zeroed out and verified already. 1916 * 1917 * Return 0 if successful, otherwise return -1. 1918 * 1919 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1920 * search with the destination IP address, and a 'magic SPI' to be 1921 * determined by the application. This is hardcoded elsewhere to 1179 1922 * right now. Another branch of this code exists which uses the SPD to 1923 * specify per-application flows but it is unstable. 1924 */ 1925 int 1926 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1927 u_char *buf, u_int direction) 1928 { 1929 union sockaddr_union dst; 1930 #ifdef INET 1931 struct ippseudo ippseudo; 1932 #endif 1933 MD5_CTX ctx; 1934 int doff; 1935 struct ip *ip; 1936 #ifdef INET 1937 struct ipovly *ipovly; 1938 #endif 1939 struct secasvar *sav; 1940 struct tcphdr *th; 1941 #ifdef INET6 1942 struct ip6_hdr *ip6; 1943 struct in6_addr in6; 1944 char ip6buf[INET6_ADDRSTRLEN]; 1945 uint32_t plen; 1946 uint16_t nhdr; 1947 #endif 1948 u_short savecsum; 1949 1950 KASSERT(m != NULL, ("NULL mbuf chain")); 1951 KASSERT(buf != NULL, ("NULL signature pointer")); 1952 1953 /* Extract the destination from the IP header in the mbuf. */ 1954 bzero(&dst, sizeof(union sockaddr_union)); 1955 ip = mtod(m, struct ip *); 1956 #ifdef INET6 1957 ip6 = NULL; /* Make the compiler happy. */ 1958 #endif 1959 switch (ip->ip_v) { 1960 #ifdef INET 1961 case IPVERSION: 1962 dst.sa.sa_len = sizeof(struct sockaddr_in); 1963 dst.sa.sa_family = AF_INET; 1964 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 1965 ip->ip_src : ip->ip_dst; 1966 break; 1967 #endif 1968 #ifdef INET6 1969 case (IPV6_VERSION >> 4): 1970 ip6 = mtod(m, struct ip6_hdr *); 1971 dst.sa.sa_len = sizeof(struct sockaddr_in6); 1972 dst.sa.sa_family = AF_INET6; 1973 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 1974 ip6->ip6_src : ip6->ip6_dst; 1975 break; 1976 #endif 1977 default: 1978 return (EINVAL); 1979 /* NOTREACHED */ 1980 break; 1981 } 1982 1983 /* Look up an SADB entry which matches the address of the peer. */ 1984 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 1985 if (sav == NULL) { 1986 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 1987 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 1988 #ifdef INET6 1989 (ip->ip_v == (IPV6_VERSION >> 4)) ? 1990 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 1991 #endif 1992 "(unsupported)")); 1993 return (EINVAL); 1994 } 1995 1996 MD5Init(&ctx); 1997 /* 1998 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 1999 * 2000 * XXX The ippseudo header MUST be digested in network byte order, 2001 * or else we'll fail the regression test. Assume all fields we've 2002 * been doing arithmetic on have been in host byte order. 2003 * XXX One cannot depend on ipovly->ih_len here. When called from 2004 * tcp_output(), the underlying ip_len member has not yet been set. 2005 */ 2006 switch (ip->ip_v) { 2007 #ifdef INET 2008 case IPVERSION: 2009 ipovly = (struct ipovly *)ip; 2010 ippseudo.ippseudo_src = ipovly->ih_src; 2011 ippseudo.ippseudo_dst = ipovly->ih_dst; 2012 ippseudo.ippseudo_pad = 0; 2013 ippseudo.ippseudo_p = IPPROTO_TCP; 2014 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2015 optlen); 2016 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2017 2018 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2019 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2020 break; 2021 #endif 2022 #ifdef INET6 2023 /* 2024 * RFC 2385, 2.0 Proposal 2025 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2026 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2027 * extended next header value (to form 32 bits), and 32-bit segment 2028 * length. 2029 * Note: Upper-Layer Packet Length comes before Next Header. 2030 */ 2031 case (IPV6_VERSION >> 4): 2032 in6 = ip6->ip6_src; 2033 in6_clearscope(&in6); 2034 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2035 in6 = ip6->ip6_dst; 2036 in6_clearscope(&in6); 2037 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2038 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2039 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2040 nhdr = 0; 2041 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2042 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2043 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2044 nhdr = IPPROTO_TCP; 2045 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2046 2047 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2048 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2049 break; 2050 #endif 2051 default: 2052 return (EINVAL); 2053 /* NOTREACHED */ 2054 break; 2055 } 2056 2057 2058 /* 2059 * Step 2: Update MD5 hash with TCP header, excluding options. 2060 * The TCP checksum must be set to zero. 2061 */ 2062 savecsum = th->th_sum; 2063 th->th_sum = 0; 2064 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2065 th->th_sum = savecsum; 2066 2067 /* 2068 * Step 3: Update MD5 hash with TCP segment data. 2069 * Use m_apply() to avoid an early m_pullup(). 2070 */ 2071 if (len > 0) 2072 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2073 2074 /* 2075 * Step 4: Update MD5 hash with shared secret. 2076 */ 2077 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2078 MD5Final(buf, &ctx); 2079 2080 key_sa_recordxfer(sav, m); 2081 KEY_FREESAV(&sav); 2082 return (0); 2083 } 2084 2085 /* 2086 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385) 2087 * 2088 * Parameters: 2089 * m pointer to head of mbuf chain 2090 * len length of TCP segment data, excluding options 2091 * optlen length of TCP segment options 2092 * buf pointer to storage for computed MD5 digest 2093 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 2094 * 2095 * Return 1 if successful, otherwise return 0. 2096 */ 2097 int 2098 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen, 2099 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag) 2100 { 2101 char tmpdigest[TCP_SIGLEN]; 2102 2103 if (tcp_sig_checksigs == 0) 2104 return (1); 2105 if ((tcpbflag & TF_SIGNATURE) == 0) { 2106 if ((to->to_flags & TOF_SIGNATURE) != 0) { 2107 2108 /* 2109 * If this socket is not expecting signature but 2110 * the segment contains signature just fail. 2111 */ 2112 TCPSTAT_INC(tcps_sig_err_sigopt); 2113 TCPSTAT_INC(tcps_sig_rcvbadsig); 2114 return (0); 2115 } 2116 2117 /* Signature is not expected, and not present in segment. */ 2118 return (1); 2119 } 2120 2121 /* 2122 * If this socket is expecting signature but the segment does not 2123 * contain any just fail. 2124 */ 2125 if ((to->to_flags & TOF_SIGNATURE) == 0) { 2126 TCPSTAT_INC(tcps_sig_err_nosigopt); 2127 TCPSTAT_INC(tcps_sig_rcvbadsig); 2128 return (0); 2129 } 2130 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0], 2131 IPSEC_DIR_INBOUND) == -1) { 2132 TCPSTAT_INC(tcps_sig_err_buildsig); 2133 TCPSTAT_INC(tcps_sig_rcvbadsig); 2134 return (0); 2135 } 2136 2137 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) { 2138 TCPSTAT_INC(tcps_sig_rcvbadsig); 2139 return (0); 2140 } 2141 TCPSTAT_INC(tcps_sig_rcvgoodsig); 2142 return (1); 2143 } 2144 #endif /* TCP_SIGNATURE */ 2145 2146 static int 2147 sysctl_drop(SYSCTL_HANDLER_ARGS) 2148 { 2149 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2150 struct sockaddr_storage addrs[2]; 2151 struct inpcb *inp; 2152 struct tcpcb *tp; 2153 struct tcptw *tw; 2154 struct sockaddr_in *fin, *lin; 2155 #ifdef INET6 2156 struct sockaddr_in6 *fin6, *lin6; 2157 #endif 2158 int error; 2159 2160 inp = NULL; 2161 fin = lin = NULL; 2162 #ifdef INET6 2163 fin6 = lin6 = NULL; 2164 #endif 2165 error = 0; 2166 2167 if (req->oldptr != NULL || req->oldlen != 0) 2168 return (EINVAL); 2169 if (req->newptr == NULL) 2170 return (EPERM); 2171 if (req->newlen < sizeof(addrs)) 2172 return (ENOMEM); 2173 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2174 if (error) 2175 return (error); 2176 2177 switch (addrs[0].ss_family) { 2178 #ifdef INET6 2179 case AF_INET6: 2180 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2181 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2182 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2183 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2184 return (EINVAL); 2185 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2186 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2187 return (EINVAL); 2188 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2189 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2190 fin = (struct sockaddr_in *)&addrs[0]; 2191 lin = (struct sockaddr_in *)&addrs[1]; 2192 break; 2193 } 2194 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2195 if (error) 2196 return (error); 2197 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2198 if (error) 2199 return (error); 2200 break; 2201 #endif 2202 #ifdef INET 2203 case AF_INET: 2204 fin = (struct sockaddr_in *)&addrs[0]; 2205 lin = (struct sockaddr_in *)&addrs[1]; 2206 if (fin->sin_len != sizeof(struct sockaddr_in) || 2207 lin->sin_len != sizeof(struct sockaddr_in)) 2208 return (EINVAL); 2209 break; 2210 #endif 2211 default: 2212 return (EINVAL); 2213 } 2214 INP_INFO_WLOCK(&V_tcbinfo); 2215 switch (addrs[0].ss_family) { 2216 #ifdef INET6 2217 case AF_INET6: 2218 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2219 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2220 INPLOOKUP_WLOCKPCB, NULL); 2221 break; 2222 #endif 2223 #ifdef INET 2224 case AF_INET: 2225 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2226 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2227 break; 2228 #endif 2229 } 2230 if (inp != NULL) { 2231 if (inp->inp_flags & INP_TIMEWAIT) { 2232 /* 2233 * XXXRW: There currently exists a state where an 2234 * inpcb is present, but its timewait state has been 2235 * discarded. For now, don't allow dropping of this 2236 * type of inpcb. 2237 */ 2238 tw = intotw(inp); 2239 if (tw != NULL) 2240 tcp_twclose(tw, 0); 2241 else 2242 INP_WUNLOCK(inp); 2243 } else if (!(inp->inp_flags & INP_DROPPED) && 2244 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2245 tp = intotcpcb(inp); 2246 tp = tcp_drop(tp, ECONNABORTED); 2247 if (tp != NULL) 2248 INP_WUNLOCK(inp); 2249 } else 2250 INP_WUNLOCK(inp); 2251 } else 2252 error = ESRCH; 2253 INP_INFO_WUNLOCK(&V_tcbinfo); 2254 return (error); 2255 } 2256 2257 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2258 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2259 0, sysctl_drop, "", "Drop TCP connection"); 2260 2261 /* 2262 * Generate a standardized TCP log line for use throughout the 2263 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2264 * allow use in the interrupt context. 2265 * 2266 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2267 * NB: The function may return NULL if memory allocation failed. 2268 * 2269 * Due to header inclusion and ordering limitations the struct ip 2270 * and ip6_hdr pointers have to be passed as void pointers. 2271 */ 2272 char * 2273 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2274 const void *ip6hdr) 2275 { 2276 2277 /* Is logging enabled? */ 2278 if (tcp_log_in_vain == 0) 2279 return (NULL); 2280 2281 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2282 } 2283 2284 char * 2285 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2286 const void *ip6hdr) 2287 { 2288 2289 /* Is logging enabled? */ 2290 if (tcp_log_debug == 0) 2291 return (NULL); 2292 2293 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2294 } 2295 2296 static char * 2297 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2298 const void *ip6hdr) 2299 { 2300 char *s, *sp; 2301 size_t size; 2302 struct ip *ip; 2303 #ifdef INET6 2304 const struct ip6_hdr *ip6; 2305 2306 ip6 = (const struct ip6_hdr *)ip6hdr; 2307 #endif /* INET6 */ 2308 ip = (struct ip *)ip4hdr; 2309 2310 /* 2311 * The log line looks like this: 2312 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2313 */ 2314 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2315 sizeof(PRINT_TH_FLAGS) + 1 + 2316 #ifdef INET6 2317 2 * INET6_ADDRSTRLEN; 2318 #else 2319 2 * INET_ADDRSTRLEN; 2320 #endif /* INET6 */ 2321 2322 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2323 if (s == NULL) 2324 return (NULL); 2325 2326 strcat(s, "TCP: ["); 2327 sp = s + strlen(s); 2328 2329 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2330 inet_ntoa_r(inc->inc_faddr, sp); 2331 sp = s + strlen(s); 2332 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2333 sp = s + strlen(s); 2334 inet_ntoa_r(inc->inc_laddr, sp); 2335 sp = s + strlen(s); 2336 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2337 #ifdef INET6 2338 } else if (inc) { 2339 ip6_sprintf(sp, &inc->inc6_faddr); 2340 sp = s + strlen(s); 2341 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2342 sp = s + strlen(s); 2343 ip6_sprintf(sp, &inc->inc6_laddr); 2344 sp = s + strlen(s); 2345 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2346 } else if (ip6 && th) { 2347 ip6_sprintf(sp, &ip6->ip6_src); 2348 sp = s + strlen(s); 2349 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2350 sp = s + strlen(s); 2351 ip6_sprintf(sp, &ip6->ip6_dst); 2352 sp = s + strlen(s); 2353 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2354 #endif /* INET6 */ 2355 #ifdef INET 2356 } else if (ip && th) { 2357 inet_ntoa_r(ip->ip_src, sp); 2358 sp = s + strlen(s); 2359 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2360 sp = s + strlen(s); 2361 inet_ntoa_r(ip->ip_dst, sp); 2362 sp = s + strlen(s); 2363 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2364 #endif /* INET */ 2365 } else { 2366 free(s, M_TCPLOG); 2367 return (NULL); 2368 } 2369 sp = s + strlen(s); 2370 if (th) 2371 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2372 if (*(s + size - 1) != '\0') 2373 panic("%s: string too long", __func__); 2374 return (s); 2375 } 2376