1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1993 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 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 30 * $FreeBSD$ 31 */ 32 33 #include "opt_bootp.h" 34 #include "opt_ipfw.h" 35 #include "opt_ipstealth.h" 36 #include "opt_ipsec.h" 37 #include "opt_mac.h" 38 #include "opt_carp.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/callout.h> 43 #include <sys/mac.h> 44 #include <sys/mbuf.h> 45 #include <sys/malloc.h> 46 #include <sys/domain.h> 47 #include <sys/protosw.h> 48 #include <sys/socket.h> 49 #include <sys/time.h> 50 #include <sys/kernel.h> 51 #include <sys/syslog.h> 52 #include <sys/sysctl.h> 53 54 #include <net/pfil.h> 55 #include <net/if.h> 56 #include <net/if_types.h> 57 #include <net/if_var.h> 58 #include <net/if_dl.h> 59 #include <net/route.h> 60 #include <net/netisr.h> 61 62 #include <netinet/in.h> 63 #include <netinet/in_systm.h> 64 #include <netinet/in_var.h> 65 #include <netinet/ip.h> 66 #include <netinet/in_pcb.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/ip_icmp.h> 69 #include <machine/in_cksum.h> 70 #ifdef DEV_CARP 71 #include <netinet/ip_carp.h> 72 #endif 73 74 #include <sys/socketvar.h> 75 76 /* XXX: Temporary until ipfw_ether and ipfw_bridge are converted. */ 77 #include <netinet/ip_fw.h> 78 #include <netinet/ip_dummynet.h> 79 80 #ifdef IPSEC 81 #include <netinet6/ipsec.h> 82 #include <netkey/key.h> 83 #endif 84 85 #ifdef FAST_IPSEC 86 #include <netipsec/ipsec.h> 87 #include <netipsec/key.h> 88 #endif 89 90 int rsvp_on = 0; 91 92 int ipforwarding = 0; 93 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, 94 &ipforwarding, 0, "Enable IP forwarding between interfaces"); 95 96 static int ipsendredirects = 1; /* XXX */ 97 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, 98 &ipsendredirects, 0, "Enable sending IP redirects"); 99 100 int ip_defttl = IPDEFTTL; 101 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW, 102 &ip_defttl, 0, "Maximum TTL on IP packets"); 103 104 static int ip_dosourceroute = 0; 105 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW, 106 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets"); 107 108 static int ip_acceptsourceroute = 0; 109 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, 110 CTLFLAG_RW, &ip_acceptsourceroute, 0, 111 "Enable accepting source routed IP packets"); 112 113 int ip_doopts = 1; /* 0 = ignore, 1 = process, 2 = reject */ 114 SYSCTL_INT(_net_inet_ip, OID_AUTO, process_options, CTLFLAG_RW, 115 &ip_doopts, 0, "Enable IP options processing ([LS]SRR, RR, TS)"); 116 117 static int ip_keepfaith = 0; 118 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW, 119 &ip_keepfaith, 0, 120 "Enable packet capture for FAITH IPv4->IPv6 translater daemon"); 121 122 static int nipq = 0; /* total # of reass queues */ 123 static int maxnipq; 124 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW, 125 &maxnipq, 0, 126 "Maximum number of IPv4 fragment reassembly queue entries"); 127 128 static int maxfragsperpacket; 129 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, 130 &maxfragsperpacket, 0, 131 "Maximum number of IPv4 fragments allowed per packet"); 132 133 static int ip_sendsourcequench = 0; 134 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, 135 &ip_sendsourcequench, 0, 136 "Enable the transmission of source quench packets"); 137 138 int ip_do_randomid = 0; 139 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, 140 &ip_do_randomid, 0, 141 "Assign random ip_id values"); 142 143 /* 144 * XXX - Setting ip_checkinterface mostly implements the receive side of 145 * the Strong ES model described in RFC 1122, but since the routing table 146 * and transmit implementation do not implement the Strong ES model, 147 * setting this to 1 results in an odd hybrid. 148 * 149 * XXX - ip_checkinterface currently must be disabled if you use ipnat 150 * to translate the destination address to another local interface. 151 * 152 * XXX - ip_checkinterface must be disabled if you add IP aliases 153 * to the loopback interface instead of the interface where the 154 * packets for those addresses are received. 155 */ 156 static int ip_checkinterface = 0; 157 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, 158 &ip_checkinterface, 0, "Verify packet arrives on correct interface"); 159 160 #ifdef DIAGNOSTIC 161 static int ipprintfs = 0; 162 #endif 163 164 struct pfil_head inet_pfil_hook; /* Packet filter hooks */ 165 166 static struct ifqueue ipintrq; 167 static int ipqmaxlen = IFQ_MAXLEN; 168 169 extern struct domain inetdomain; 170 extern struct protosw inetsw[]; 171 u_char ip_protox[IPPROTO_MAX]; 172 struct in_ifaddrhead in_ifaddrhead; /* first inet address */ 173 struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */ 174 u_long in_ifaddrhmask; /* mask for hash table */ 175 176 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW, 177 &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue"); 178 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD, 179 &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue"); 180 181 struct ipstat ipstat; 182 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW, 183 &ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)"); 184 185 /* Packet reassembly stuff */ 186 #define IPREASS_NHASH_LOG2 6 187 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) 188 #define IPREASS_HMASK (IPREASS_NHASH - 1) 189 #define IPREASS_HASH(x,y) \ 190 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK) 191 192 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH]; 193 struct mtx ipqlock; 194 struct callout ipport_tick_callout; 195 196 #define IPQ_LOCK() mtx_lock(&ipqlock) 197 #define IPQ_UNLOCK() mtx_unlock(&ipqlock) 198 #define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF) 199 #define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED) 200 201 #ifdef IPCTL_DEFMTU 202 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, 203 &ip_mtu, 0, "Default MTU"); 204 #endif 205 206 #ifdef IPSTEALTH 207 int ipstealth = 0; 208 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, 209 &ipstealth, 0, ""); 210 #endif 211 212 /* 213 * ipfw_ether and ipfw_bridge hooks. 214 * XXX: Temporary until those are converted to pfil_hooks as well. 215 */ 216 ip_fw_chk_t *ip_fw_chk_ptr = NULL; 217 ip_dn_io_t *ip_dn_io_ptr = NULL; 218 int fw_enable = 1; 219 int fw_one_pass = 1; 220 221 /* 222 * XXX this is ugly. IP options source routing magic. 223 */ 224 struct ipoptrt { 225 struct in_addr dst; /* final destination */ 226 char nop; /* one NOP to align */ 227 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 228 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 229 }; 230 231 struct ipopt_tag { 232 struct m_tag tag; 233 int ip_nhops; 234 struct ipoptrt ip_srcrt; 235 }; 236 237 static void save_rte(struct mbuf *, u_char *, struct in_addr); 238 static int ip_dooptions(struct mbuf *m, int); 239 static void ip_forward(struct mbuf *m, int srcrt); 240 static void ip_freef(struct ipqhead *, struct ipq *); 241 242 /* 243 * IP initialization: fill in IP protocol switch table. 244 * All protocols not implemented in kernel go to raw IP protocol handler. 245 */ 246 void 247 ip_init() 248 { 249 register struct protosw *pr; 250 register int i; 251 252 TAILQ_INIT(&in_ifaddrhead); 253 in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask); 254 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 255 if (pr == NULL) 256 panic("ip_init: PF_INET not found"); 257 258 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 259 for (i = 0; i < IPPROTO_MAX; i++) 260 ip_protox[i] = pr - inetsw; 261 /* 262 * Cycle through IP protocols and put them into the appropriate place 263 * in ip_protox[]. 264 */ 265 for (pr = inetdomain.dom_protosw; 266 pr < inetdomain.dom_protoswNPROTOSW; pr++) 267 if (pr->pr_domain->dom_family == PF_INET && 268 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 269 /* Be careful to only index valid IP protocols. */ 270 if (pr->pr_protocol < IPPROTO_MAX) 271 ip_protox[pr->pr_protocol] = pr - inetsw; 272 } 273 274 /* Initialize packet filter hooks. */ 275 inet_pfil_hook.ph_type = PFIL_TYPE_AF; 276 inet_pfil_hook.ph_af = AF_INET; 277 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) 278 printf("%s: WARNING: unable to register pfil hook, " 279 "error %d\n", __func__, i); 280 281 /* Initialize IP reassembly queue. */ 282 IPQ_LOCK_INIT(); 283 for (i = 0; i < IPREASS_NHASH; i++) 284 TAILQ_INIT(&ipq[i]); 285 maxnipq = nmbclusters / 32; 286 maxfragsperpacket = 16; 287 288 /* Start ipport_tick. */ 289 callout_init(&ipport_tick_callout, CALLOUT_MPSAFE); 290 ipport_tick(NULL); 291 EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL, 292 SHUTDOWN_PRI_DEFAULT); 293 294 /* Initialize various other remaining things. */ 295 ip_id = time_second & 0xffff; 296 ipintrq.ifq_maxlen = ipqmaxlen; 297 mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF); 298 netisr_register(NETISR_IP, ip_input, &ipintrq, NETISR_MPSAFE); 299 } 300 301 void ip_fini(xtp) 302 void *xtp; 303 { 304 callout_stop(&ipport_tick_callout); 305 } 306 307 /* 308 * Ip input routine. Checksum and byte swap header. If fragmented 309 * try to reassemble. Process options. Pass to next level. 310 */ 311 void 312 ip_input(struct mbuf *m) 313 { 314 struct ip *ip = NULL; 315 struct in_ifaddr *ia = NULL; 316 struct ifaddr *ifa; 317 int checkif, hlen = 0; 318 u_short sum; 319 int dchg = 0; /* dest changed after fw */ 320 struct in_addr odst; /* original dst address */ 321 #ifdef FAST_IPSEC 322 struct m_tag *mtag; 323 struct tdb_ident *tdbi; 324 struct secpolicy *sp; 325 int s, error; 326 #endif /* FAST_IPSEC */ 327 328 M_ASSERTPKTHDR(m); 329 330 if (m->m_flags & M_FASTFWD_OURS) { 331 /* 332 * Firewall or NAT changed destination to local. 333 * We expect ip_len and ip_off to be in host byte order. 334 */ 335 m->m_flags &= ~M_FASTFWD_OURS; 336 /* Set up some basics that will be used later. */ 337 ip = mtod(m, struct ip *); 338 hlen = ip->ip_hl << 2; 339 goto ours; 340 } 341 342 ipstat.ips_total++; 343 344 if (m->m_pkthdr.len < sizeof(struct ip)) 345 goto tooshort; 346 347 if (m->m_len < sizeof (struct ip) && 348 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 349 ipstat.ips_toosmall++; 350 return; 351 } 352 ip = mtod(m, struct ip *); 353 354 if (ip->ip_v != IPVERSION) { 355 ipstat.ips_badvers++; 356 goto bad; 357 } 358 359 hlen = ip->ip_hl << 2; 360 if (hlen < sizeof(struct ip)) { /* minimum header length */ 361 ipstat.ips_badhlen++; 362 goto bad; 363 } 364 if (hlen > m->m_len) { 365 if ((m = m_pullup(m, hlen)) == NULL) { 366 ipstat.ips_badhlen++; 367 return; 368 } 369 ip = mtod(m, struct ip *); 370 } 371 372 /* 127/8 must not appear on wire - RFC1122 */ 373 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 374 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 375 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 376 ipstat.ips_badaddr++; 377 goto bad; 378 } 379 } 380 381 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { 382 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); 383 } else { 384 if (hlen == sizeof(struct ip)) { 385 sum = in_cksum_hdr(ip); 386 } else { 387 sum = in_cksum(m, hlen); 388 } 389 } 390 if (sum) { 391 ipstat.ips_badsum++; 392 goto bad; 393 } 394 395 #ifdef ALTQ 396 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) 397 /* packet is dropped by traffic conditioner */ 398 return; 399 #endif 400 401 /* 402 * Convert fields to host representation. 403 */ 404 ip->ip_len = ntohs(ip->ip_len); 405 if (ip->ip_len < hlen) { 406 ipstat.ips_badlen++; 407 goto bad; 408 } 409 ip->ip_off = ntohs(ip->ip_off); 410 411 /* 412 * Check that the amount of data in the buffers 413 * is as at least much as the IP header would have us expect. 414 * Trim mbufs if longer than we expect. 415 * Drop packet if shorter than we expect. 416 */ 417 if (m->m_pkthdr.len < ip->ip_len) { 418 tooshort: 419 ipstat.ips_tooshort++; 420 goto bad; 421 } 422 if (m->m_pkthdr.len > ip->ip_len) { 423 if (m->m_len == m->m_pkthdr.len) { 424 m->m_len = ip->ip_len; 425 m->m_pkthdr.len = ip->ip_len; 426 } else 427 m_adj(m, ip->ip_len - m->m_pkthdr.len); 428 } 429 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF) 430 /* 431 * Bypass packet filtering for packets from a tunnel (gif). 432 */ 433 if (ipsec_getnhist(m)) 434 goto passin; 435 #endif 436 #if defined(FAST_IPSEC) && !defined(IPSEC_FILTERGIF) 437 /* 438 * Bypass packet filtering for packets from a tunnel (gif). 439 */ 440 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 441 goto passin; 442 #endif 443 444 /* 445 * Run through list of hooks for input packets. 446 * 447 * NB: Beware of the destination address changing (e.g. 448 * by NAT rewriting). When this happens, tell 449 * ip_forward to do the right thing. 450 */ 451 452 /* Jump over all PFIL processing if hooks are not active. */ 453 if (inet_pfil_hook.ph_busy_count == -1) 454 goto passin; 455 456 odst = ip->ip_dst; 457 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, 458 PFIL_IN, NULL) != 0) 459 return; 460 if (m == NULL) /* consumed by filter */ 461 return; 462 463 ip = mtod(m, struct ip *); 464 dchg = (odst.s_addr != ip->ip_dst.s_addr); 465 466 #ifdef IPFIREWALL_FORWARD 467 if (m->m_flags & M_FASTFWD_OURS) { 468 m->m_flags &= ~M_FASTFWD_OURS; 469 goto ours; 470 } 471 #ifndef IPFIREWALL_FORWARD_EXTENDED 472 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL); 473 #else 474 if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) { 475 /* 476 * Directly ship on the packet. This allows to forward packets 477 * that were destined for us to some other directly connected 478 * host. 479 */ 480 ip_forward(m, dchg); 481 return; 482 } 483 #endif /* IPFIREWALL_FORWARD_EXTENDED */ 484 #endif /* IPFIREWALL_FORWARD */ 485 486 passin: 487 /* 488 * Process options and, if not destined for us, 489 * ship it on. ip_dooptions returns 1 when an 490 * error was detected (causing an icmp message 491 * to be sent and the original packet to be freed). 492 */ 493 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0)) 494 return; 495 496 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no 497 * matter if it is destined to another node, or whether it is 498 * a multicast one, RSVP wants it! and prevents it from being forwarded 499 * anywhere else. Also checks if the rsvp daemon is running before 500 * grabbing the packet. 501 */ 502 if (rsvp_on && ip->ip_p==IPPROTO_RSVP) 503 goto ours; 504 505 /* 506 * Check our list of addresses, to see if the packet is for us. 507 * If we don't have any addresses, assume any unicast packet 508 * we receive might be for us (and let the upper layers deal 509 * with it). 510 */ 511 if (TAILQ_EMPTY(&in_ifaddrhead) && 512 (m->m_flags & (M_MCAST|M_BCAST)) == 0) 513 goto ours; 514 515 /* 516 * Enable a consistency check between the destination address 517 * and the arrival interface for a unicast packet (the RFC 1122 518 * strong ES model) if IP forwarding is disabled and the packet 519 * is not locally generated and the packet is not subject to 520 * 'ipfw fwd'. 521 * 522 * XXX - Checking also should be disabled if the destination 523 * address is ipnat'ed to a different interface. 524 * 525 * XXX - Checking is incompatible with IP aliases added 526 * to the loopback interface instead of the interface where 527 * the packets are received. 528 * 529 * XXX - This is the case for carp vhost IPs as well so we 530 * insert a workaround. If the packet got here, we already 531 * checked with carp_iamatch() and carp_forus(). 532 */ 533 checkif = ip_checkinterface && (ipforwarding == 0) && 534 m->m_pkthdr.rcvif != NULL && 535 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) && 536 #ifdef DEV_CARP 537 !m->m_pkthdr.rcvif->if_carp && 538 #endif 539 (dchg == 0); 540 541 /* 542 * Check for exact addresses in the hash bucket. 543 */ 544 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) { 545 /* 546 * If the address matches, verify that the packet 547 * arrived via the correct interface if checking is 548 * enabled. 549 */ 550 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr && 551 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) 552 goto ours; 553 } 554 /* 555 * Check for broadcast addresses. 556 * 557 * Only accept broadcast packets that arrive via the matching 558 * interface. Reception of forwarded directed broadcasts would 559 * be handled via ip_forward() and ether_output() with the loopback 560 * into the stack for SIMPLEX interfaces handled by ether_output(). 561 */ 562 if (m->m_pkthdr.rcvif != NULL && 563 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 564 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) { 565 if (ifa->ifa_addr->sa_family != AF_INET) 566 continue; 567 ia = ifatoia(ifa); 568 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 569 ip->ip_dst.s_addr) 570 goto ours; 571 if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr) 572 goto ours; 573 #ifdef BOOTP_COMPAT 574 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) 575 goto ours; 576 #endif 577 } 578 } 579 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 580 struct in_multi *inm; 581 if (ip_mrouter) { 582 /* 583 * If we are acting as a multicast router, all 584 * incoming multicast packets are passed to the 585 * kernel-level multicast forwarding function. 586 * The packet is returned (relatively) intact; if 587 * ip_mforward() returns a non-zero value, the packet 588 * must be discarded, else it may be accepted below. 589 */ 590 if (ip_mforward && 591 ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) { 592 ipstat.ips_cantforward++; 593 m_freem(m); 594 return; 595 } 596 597 /* 598 * The process-level routing daemon needs to receive 599 * all multicast IGMP packets, whether or not this 600 * host belongs to their destination groups. 601 */ 602 if (ip->ip_p == IPPROTO_IGMP) 603 goto ours; 604 ipstat.ips_forward++; 605 } 606 /* 607 * See if we belong to the destination multicast group on the 608 * arrival interface. 609 */ 610 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 611 if (inm == NULL) { 612 ipstat.ips_notmember++; 613 m_freem(m); 614 return; 615 } 616 goto ours; 617 } 618 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST) 619 goto ours; 620 if (ip->ip_dst.s_addr == INADDR_ANY) 621 goto ours; 622 623 /* 624 * FAITH(Firewall Aided Internet Translator) 625 */ 626 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { 627 if (ip_keepfaith) { 628 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP) 629 goto ours; 630 } 631 m_freem(m); 632 return; 633 } 634 635 /* 636 * Not for us; forward if possible and desirable. 637 */ 638 if (ipforwarding == 0) { 639 ipstat.ips_cantforward++; 640 m_freem(m); 641 } else { 642 #ifdef IPSEC 643 /* 644 * Enforce inbound IPsec SPD. 645 */ 646 if (ipsec4_in_reject(m, NULL)) { 647 ipsecstat.in_polvio++; 648 goto bad; 649 } 650 #endif /* IPSEC */ 651 #ifdef FAST_IPSEC 652 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 653 s = splnet(); 654 if (mtag != NULL) { 655 tdbi = (struct tdb_ident *)(mtag + 1); 656 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 657 } else { 658 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 659 IP_FORWARDING, &error); 660 } 661 if (sp == NULL) { /* NB: can happen if error */ 662 splx(s); 663 /*XXX error stat???*/ 664 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/ 665 goto bad; 666 } 667 668 /* 669 * Check security policy against packet attributes. 670 */ 671 error = ipsec_in_reject(sp, m); 672 KEY_FREESP(&sp); 673 splx(s); 674 if (error) { 675 ipstat.ips_cantforward++; 676 goto bad; 677 } 678 #endif /* FAST_IPSEC */ 679 ip_forward(m, dchg); 680 } 681 return; 682 683 ours: 684 #ifdef IPSTEALTH 685 /* 686 * IPSTEALTH: Process non-routing options only 687 * if the packet is destined for us. 688 */ 689 if (ipstealth && hlen > sizeof (struct ip) && 690 ip_dooptions(m, 1)) 691 return; 692 #endif /* IPSTEALTH */ 693 694 /* Count the packet in the ip address stats */ 695 if (ia != NULL) { 696 ia->ia_ifa.if_ipackets++; 697 ia->ia_ifa.if_ibytes += m->m_pkthdr.len; 698 } 699 700 /* 701 * Attempt reassembly; if it succeeds, proceed. 702 * ip_reass() will return a different mbuf. 703 */ 704 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 705 m = ip_reass(m); 706 if (m == NULL) 707 return; 708 ip = mtod(m, struct ip *); 709 /* Get the header length of the reassembled packet */ 710 hlen = ip->ip_hl << 2; 711 } 712 713 /* 714 * Further protocols expect the packet length to be w/o the 715 * IP header. 716 */ 717 ip->ip_len -= hlen; 718 719 #ifdef IPSEC 720 /* 721 * enforce IPsec policy checking if we are seeing last header. 722 * note that we do not visit this with protocols with pcb layer 723 * code - like udp/tcp/raw ip. 724 */ 725 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 && 726 ipsec4_in_reject(m, NULL)) { 727 ipsecstat.in_polvio++; 728 goto bad; 729 } 730 #endif 731 #if FAST_IPSEC 732 /* 733 * enforce IPsec policy checking if we are seeing last header. 734 * note that we do not visit this with protocols with pcb layer 735 * code - like udp/tcp/raw ip. 736 */ 737 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) { 738 /* 739 * Check if the packet has already had IPsec processing 740 * done. If so, then just pass it along. This tag gets 741 * set during AH, ESP, etc. input handling, before the 742 * packet is returned to the ip input queue for delivery. 743 */ 744 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 745 s = splnet(); 746 if (mtag != NULL) { 747 tdbi = (struct tdb_ident *)(mtag + 1); 748 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 749 } else { 750 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 751 IP_FORWARDING, &error); 752 } 753 if (sp != NULL) { 754 /* 755 * Check security policy against packet attributes. 756 */ 757 error = ipsec_in_reject(sp, m); 758 KEY_FREESP(&sp); 759 } else { 760 /* XXX error stat??? */ 761 error = EINVAL; 762 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/ 763 goto bad; 764 } 765 splx(s); 766 if (error) 767 goto bad; 768 } 769 #endif /* FAST_IPSEC */ 770 771 /* 772 * Switch out to protocol's input routine. 773 */ 774 ipstat.ips_delivered++; 775 776 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 777 return; 778 bad: 779 m_freem(m); 780 } 781 782 /* 783 * Take incoming datagram fragment and try to reassemble it into 784 * whole datagram. If the argument is the first fragment or one 785 * in between the function will return NULL and store the mbuf 786 * in the fragment chain. If the argument is the last fragment 787 * the packet will be reassembled and the pointer to the new 788 * mbuf returned for further processing. Only m_tags attached 789 * to the first packet/fragment are preserved. 790 * The IP header is *NOT* adjusted out of iplen. 791 */ 792 793 struct mbuf * 794 ip_reass(struct mbuf *m) 795 { 796 struct ip *ip; 797 struct mbuf *p, *q, *nq, *t; 798 struct ipq *fp = NULL; 799 struct ipqhead *head; 800 int i, hlen, next; 801 u_int8_t ecn, ecn0; 802 u_short hash; 803 804 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */ 805 if (maxnipq == 0 || maxfragsperpacket == 0) { 806 ipstat.ips_fragments++; 807 ipstat.ips_fragdropped++; 808 m_freem(m); 809 return (NULL); 810 } 811 812 ip = mtod(m, struct ip *); 813 hlen = ip->ip_hl << 2; 814 815 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); 816 head = &ipq[hash]; 817 IPQ_LOCK(); 818 819 /* 820 * Look for queue of fragments 821 * of this datagram. 822 */ 823 TAILQ_FOREACH(fp, head, ipq_list) 824 if (ip->ip_id == fp->ipq_id && 825 ip->ip_src.s_addr == fp->ipq_src.s_addr && 826 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 827 #ifdef MAC 828 mac_fragment_match(m, fp) && 829 #endif 830 ip->ip_p == fp->ipq_p) 831 goto found; 832 833 fp = NULL; 834 835 /* 836 * Enforce upper bound on number of fragmented packets 837 * for which we attempt reassembly; 838 * If maxnipq is -1, accept all fragments without limitation. 839 */ 840 if ((nipq > maxnipq) && (maxnipq > 0)) { 841 /* 842 * drop something from the tail of the current queue 843 * before proceeding further 844 */ 845 struct ipq *q = TAILQ_LAST(head, ipqhead); 846 if (q == NULL) { /* gak */ 847 for (i = 0; i < IPREASS_NHASH; i++) { 848 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead); 849 if (r) { 850 ipstat.ips_fragtimeout += r->ipq_nfrags; 851 ip_freef(&ipq[i], r); 852 break; 853 } 854 } 855 } else { 856 ipstat.ips_fragtimeout += q->ipq_nfrags; 857 ip_freef(head, q); 858 } 859 } 860 861 found: 862 /* 863 * Adjust ip_len to not reflect header, 864 * convert offset of this to bytes. 865 */ 866 ip->ip_len -= hlen; 867 if (ip->ip_off & IP_MF) { 868 /* 869 * Make sure that fragments have a data length 870 * that's a non-zero multiple of 8 bytes. 871 */ 872 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 873 ipstat.ips_toosmall++; /* XXX */ 874 goto dropfrag; 875 } 876 m->m_flags |= M_FRAG; 877 } else 878 m->m_flags &= ~M_FRAG; 879 ip->ip_off <<= 3; 880 881 882 /* 883 * Attempt reassembly; if it succeeds, proceed. 884 * ip_reass() will return a different mbuf. 885 */ 886 ipstat.ips_fragments++; 887 m->m_pkthdr.header = ip; 888 889 /* Previous ip_reass() started here. */ 890 /* 891 * Presence of header sizes in mbufs 892 * would confuse code below. 893 */ 894 m->m_data += hlen; 895 m->m_len -= hlen; 896 897 /* 898 * If first fragment to arrive, create a reassembly queue. 899 */ 900 if (fp == NULL) { 901 if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL) 902 goto dropfrag; 903 fp = mtod(t, struct ipq *); 904 #ifdef MAC 905 if (mac_init_ipq(fp, M_NOWAIT) != 0) { 906 m_free(t); 907 goto dropfrag; 908 } 909 mac_create_ipq(m, fp); 910 #endif 911 TAILQ_INSERT_HEAD(head, fp, ipq_list); 912 nipq++; 913 fp->ipq_nfrags = 1; 914 fp->ipq_ttl = IPFRAGTTL; 915 fp->ipq_p = ip->ip_p; 916 fp->ipq_id = ip->ip_id; 917 fp->ipq_src = ip->ip_src; 918 fp->ipq_dst = ip->ip_dst; 919 fp->ipq_frags = m; 920 m->m_nextpkt = NULL; 921 goto done; 922 } else { 923 fp->ipq_nfrags++; 924 #ifdef MAC 925 mac_update_ipq(m, fp); 926 #endif 927 } 928 929 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header)) 930 931 /* 932 * Handle ECN by comparing this segment with the first one; 933 * if CE is set, do not lose CE. 934 * drop if CE and not-ECT are mixed for the same packet. 935 */ 936 ecn = ip->ip_tos & IPTOS_ECN_MASK; 937 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK; 938 if (ecn == IPTOS_ECN_CE) { 939 if (ecn0 == IPTOS_ECN_NOTECT) 940 goto dropfrag; 941 if (ecn0 != IPTOS_ECN_CE) 942 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE; 943 } 944 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) 945 goto dropfrag; 946 947 /* 948 * Find a segment which begins after this one does. 949 */ 950 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) 951 if (GETIP(q)->ip_off > ip->ip_off) 952 break; 953 954 /* 955 * If there is a preceding segment, it may provide some of 956 * our data already. If so, drop the data from the incoming 957 * segment. If it provides all of our data, drop us, otherwise 958 * stick new segment in the proper place. 959 * 960 * If some of the data is dropped from the the preceding 961 * segment, then it's checksum is invalidated. 962 */ 963 if (p) { 964 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off; 965 if (i > 0) { 966 if (i >= ip->ip_len) 967 goto dropfrag; 968 m_adj(m, i); 969 m->m_pkthdr.csum_flags = 0; 970 ip->ip_off += i; 971 ip->ip_len -= i; 972 } 973 m->m_nextpkt = p->m_nextpkt; 974 p->m_nextpkt = m; 975 } else { 976 m->m_nextpkt = fp->ipq_frags; 977 fp->ipq_frags = m; 978 } 979 980 /* 981 * While we overlap succeeding segments trim them or, 982 * if they are completely covered, dequeue them. 983 */ 984 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off; 985 q = nq) { 986 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off; 987 if (i < GETIP(q)->ip_len) { 988 GETIP(q)->ip_len -= i; 989 GETIP(q)->ip_off += i; 990 m_adj(q, i); 991 q->m_pkthdr.csum_flags = 0; 992 break; 993 } 994 nq = q->m_nextpkt; 995 m->m_nextpkt = nq; 996 ipstat.ips_fragdropped++; 997 fp->ipq_nfrags--; 998 m_freem(q); 999 } 1000 1001 /* 1002 * Check for complete reassembly and perform frag per packet 1003 * limiting. 1004 * 1005 * Frag limiting is performed here so that the nth frag has 1006 * a chance to complete the packet before we drop the packet. 1007 * As a result, n+1 frags are actually allowed per packet, but 1008 * only n will ever be stored. (n = maxfragsperpacket.) 1009 * 1010 */ 1011 next = 0; 1012 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1013 if (GETIP(q)->ip_off != next) { 1014 if (fp->ipq_nfrags > maxfragsperpacket) { 1015 ipstat.ips_fragdropped += fp->ipq_nfrags; 1016 ip_freef(head, fp); 1017 } 1018 goto done; 1019 } 1020 next += GETIP(q)->ip_len; 1021 } 1022 /* Make sure the last packet didn't have the IP_MF flag */ 1023 if (p->m_flags & M_FRAG) { 1024 if (fp->ipq_nfrags > maxfragsperpacket) { 1025 ipstat.ips_fragdropped += fp->ipq_nfrags; 1026 ip_freef(head, fp); 1027 } 1028 goto done; 1029 } 1030 1031 /* 1032 * Reassembly is complete. Make sure the packet is a sane size. 1033 */ 1034 q = fp->ipq_frags; 1035 ip = GETIP(q); 1036 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) { 1037 ipstat.ips_toolong++; 1038 ipstat.ips_fragdropped += fp->ipq_nfrags; 1039 ip_freef(head, fp); 1040 goto done; 1041 } 1042 1043 /* 1044 * Concatenate fragments. 1045 */ 1046 m = q; 1047 t = m->m_next; 1048 m->m_next = NULL; 1049 m_cat(m, t); 1050 nq = q->m_nextpkt; 1051 q->m_nextpkt = NULL; 1052 for (q = nq; q != NULL; q = nq) { 1053 nq = q->m_nextpkt; 1054 q->m_nextpkt = NULL; 1055 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 1056 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 1057 m_cat(m, q); 1058 } 1059 #ifdef MAC 1060 mac_create_datagram_from_ipq(fp, m); 1061 mac_destroy_ipq(fp); 1062 #endif 1063 1064 /* 1065 * Create header for new ip packet by modifying header of first 1066 * packet; dequeue and discard fragment reassembly header. 1067 * Make header visible. 1068 */ 1069 ip->ip_len = (ip->ip_hl << 2) + next; 1070 ip->ip_src = fp->ipq_src; 1071 ip->ip_dst = fp->ipq_dst; 1072 TAILQ_REMOVE(head, fp, ipq_list); 1073 nipq--; 1074 (void) m_free(dtom(fp)); 1075 m->m_len += (ip->ip_hl << 2); 1076 m->m_data -= (ip->ip_hl << 2); 1077 /* some debugging cruft by sklower, below, will go away soon */ 1078 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */ 1079 m_fixhdr(m); 1080 ipstat.ips_reassembled++; 1081 IPQ_UNLOCK(); 1082 return (m); 1083 1084 dropfrag: 1085 ipstat.ips_fragdropped++; 1086 if (fp != NULL) 1087 fp->ipq_nfrags--; 1088 m_freem(m); 1089 done: 1090 IPQ_UNLOCK(); 1091 return (NULL); 1092 1093 #undef GETIP 1094 } 1095 1096 /* 1097 * Free a fragment reassembly header and all 1098 * associated datagrams. 1099 */ 1100 static void 1101 ip_freef(fhp, fp) 1102 struct ipqhead *fhp; 1103 struct ipq *fp; 1104 { 1105 register struct mbuf *q; 1106 1107 IPQ_LOCK_ASSERT(); 1108 1109 while (fp->ipq_frags) { 1110 q = fp->ipq_frags; 1111 fp->ipq_frags = q->m_nextpkt; 1112 m_freem(q); 1113 } 1114 TAILQ_REMOVE(fhp, fp, ipq_list); 1115 (void) m_free(dtom(fp)); 1116 nipq--; 1117 } 1118 1119 /* 1120 * IP timer processing; 1121 * if a timer expires on a reassembly 1122 * queue, discard it. 1123 */ 1124 void 1125 ip_slowtimo() 1126 { 1127 register struct ipq *fp; 1128 int i; 1129 1130 IPQ_LOCK(); 1131 for (i = 0; i < IPREASS_NHASH; i++) { 1132 for(fp = TAILQ_FIRST(&ipq[i]); fp;) { 1133 struct ipq *fpp; 1134 1135 fpp = fp; 1136 fp = TAILQ_NEXT(fp, ipq_list); 1137 if(--fpp->ipq_ttl == 0) { 1138 ipstat.ips_fragtimeout += fpp->ipq_nfrags; 1139 ip_freef(&ipq[i], fpp); 1140 } 1141 } 1142 } 1143 /* 1144 * If we are over the maximum number of fragments 1145 * (due to the limit being lowered), drain off 1146 * enough to get down to the new limit. 1147 */ 1148 if (maxnipq >= 0 && nipq > maxnipq) { 1149 for (i = 0; i < IPREASS_NHASH; i++) { 1150 while (nipq > maxnipq && !TAILQ_EMPTY(&ipq[i])) { 1151 ipstat.ips_fragdropped += 1152 TAILQ_FIRST(&ipq[i])->ipq_nfrags; 1153 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i])); 1154 } 1155 } 1156 } 1157 IPQ_UNLOCK(); 1158 } 1159 1160 /* 1161 * Drain off all datagram fragments. 1162 */ 1163 void 1164 ip_drain() 1165 { 1166 int i; 1167 1168 IPQ_LOCK(); 1169 for (i = 0; i < IPREASS_NHASH; i++) { 1170 while(!TAILQ_EMPTY(&ipq[i])) { 1171 ipstat.ips_fragdropped += 1172 TAILQ_FIRST(&ipq[i])->ipq_nfrags; 1173 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i])); 1174 } 1175 } 1176 IPQ_UNLOCK(); 1177 in_rtqdrain(); 1178 } 1179 1180 /* 1181 * The protocol to be inserted into ip_protox[] must be already registered 1182 * in inetsw[], either statically or through pf_proto_register(). 1183 */ 1184 int 1185 ipproto_register(u_char ipproto) 1186 { 1187 struct protosw *pr; 1188 1189 /* Sanity checks. */ 1190 if (ipproto == 0) 1191 return (EPROTONOSUPPORT); 1192 1193 /* 1194 * The protocol slot must not be occupied by another protocol 1195 * already. An index pointing to IPPROTO_RAW is unused. 1196 */ 1197 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 1198 if (pr == NULL) 1199 return (EPFNOSUPPORT); 1200 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */ 1201 return (EEXIST); 1202 1203 /* Find the protocol position in inetsw[] and set the index. */ 1204 for (pr = inetdomain.dom_protosw; 1205 pr < inetdomain.dom_protoswNPROTOSW; pr++) { 1206 if (pr->pr_domain->dom_family == PF_INET && 1207 pr->pr_protocol && pr->pr_protocol == ipproto) { 1208 /* Be careful to only index valid IP protocols. */ 1209 if (pr->pr_protocol < IPPROTO_MAX) { 1210 ip_protox[pr->pr_protocol] = pr - inetsw; 1211 return (0); 1212 } else 1213 return (EINVAL); 1214 } 1215 } 1216 return (EPROTONOSUPPORT); 1217 } 1218 1219 int 1220 ipproto_unregister(u_char ipproto) 1221 { 1222 struct protosw *pr; 1223 1224 /* Sanity checks. */ 1225 if (ipproto == 0) 1226 return (EPROTONOSUPPORT); 1227 1228 /* Check if the protocol was indeed registered. */ 1229 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 1230 if (pr == NULL) 1231 return (EPFNOSUPPORT); 1232 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */ 1233 return (ENOENT); 1234 1235 /* Reset the protocol slot to IPPROTO_RAW. */ 1236 ip_protox[ipproto] = pr - inetsw; 1237 return (0); 1238 } 1239 1240 1241 /* 1242 * Do option processing on a datagram, 1243 * possibly discarding it if bad options are encountered, 1244 * or forwarding it if source-routed. 1245 * The pass argument is used when operating in the IPSTEALTH 1246 * mode to tell what options to process: 1247 * [LS]SRR (pass 0) or the others (pass 1). 1248 * The reason for as many as two passes is that when doing IPSTEALTH, 1249 * non-routing options should be processed only if the packet is for us. 1250 * Returns 1 if packet has been forwarded/freed, 1251 * 0 if the packet should be processed further. 1252 */ 1253 static int 1254 ip_dooptions(struct mbuf *m, int pass) 1255 { 1256 struct ip *ip = mtod(m, struct ip *); 1257 u_char *cp; 1258 struct in_ifaddr *ia; 1259 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 1260 struct in_addr *sin, dst; 1261 n_time ntime; 1262 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 1263 1264 /* ignore or reject packets with IP options */ 1265 if (ip_doopts == 0) 1266 return 0; 1267 else if (ip_doopts == 2) { 1268 type = ICMP_UNREACH; 1269 code = ICMP_UNREACH_FILTER_PROHIB; 1270 goto bad; 1271 } 1272 1273 dst = ip->ip_dst; 1274 cp = (u_char *)(ip + 1); 1275 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1276 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1277 opt = cp[IPOPT_OPTVAL]; 1278 if (opt == IPOPT_EOL) 1279 break; 1280 if (opt == IPOPT_NOP) 1281 optlen = 1; 1282 else { 1283 if (cnt < IPOPT_OLEN + sizeof(*cp)) { 1284 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1285 goto bad; 1286 } 1287 optlen = cp[IPOPT_OLEN]; 1288 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 1289 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1290 goto bad; 1291 } 1292 } 1293 switch (opt) { 1294 1295 default: 1296 break; 1297 1298 /* 1299 * Source routing with record. 1300 * Find interface with current destination address. 1301 * If none on this machine then drop if strictly routed, 1302 * or do nothing if loosely routed. 1303 * Record interface address and bring up next address 1304 * component. If strictly routed make sure next 1305 * address is on directly accessible net. 1306 */ 1307 case IPOPT_LSRR: 1308 case IPOPT_SSRR: 1309 #ifdef IPSTEALTH 1310 if (ipstealth && pass > 0) 1311 break; 1312 #endif 1313 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1314 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1315 goto bad; 1316 } 1317 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1318 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1319 goto bad; 1320 } 1321 ipaddr.sin_addr = ip->ip_dst; 1322 ia = (struct in_ifaddr *) 1323 ifa_ifwithaddr((struct sockaddr *)&ipaddr); 1324 if (ia == NULL) { 1325 if (opt == IPOPT_SSRR) { 1326 type = ICMP_UNREACH; 1327 code = ICMP_UNREACH_SRCFAIL; 1328 goto bad; 1329 } 1330 if (!ip_dosourceroute) 1331 goto nosourcerouting; 1332 /* 1333 * Loose routing, and not at next destination 1334 * yet; nothing to do except forward. 1335 */ 1336 break; 1337 } 1338 off--; /* 0 origin */ 1339 if (off > optlen - (int)sizeof(struct in_addr)) { 1340 /* 1341 * End of source route. Should be for us. 1342 */ 1343 if (!ip_acceptsourceroute) 1344 goto nosourcerouting; 1345 save_rte(m, cp, ip->ip_src); 1346 break; 1347 } 1348 #ifdef IPSTEALTH 1349 if (ipstealth) 1350 goto dropit; 1351 #endif 1352 if (!ip_dosourceroute) { 1353 if (ipforwarding) { 1354 char buf[16]; /* aaa.bbb.ccc.ddd\0 */ 1355 /* 1356 * Acting as a router, so generate ICMP 1357 */ 1358 nosourcerouting: 1359 strcpy(buf, inet_ntoa(ip->ip_dst)); 1360 log(LOG_WARNING, 1361 "attempted source route from %s to %s\n", 1362 inet_ntoa(ip->ip_src), buf); 1363 type = ICMP_UNREACH; 1364 code = ICMP_UNREACH_SRCFAIL; 1365 goto bad; 1366 } else { 1367 /* 1368 * Not acting as a router, so silently drop. 1369 */ 1370 #ifdef IPSTEALTH 1371 dropit: 1372 #endif 1373 ipstat.ips_cantforward++; 1374 m_freem(m); 1375 return (1); 1376 } 1377 } 1378 1379 /* 1380 * locate outgoing interface 1381 */ 1382 (void)memcpy(&ipaddr.sin_addr, cp + off, 1383 sizeof(ipaddr.sin_addr)); 1384 1385 if (opt == IPOPT_SSRR) { 1386 #define INA struct in_ifaddr * 1387 #define SA struct sockaddr * 1388 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == NULL) 1389 ia = (INA)ifa_ifwithnet((SA)&ipaddr); 1390 } else 1391 ia = ip_rtaddr(ipaddr.sin_addr); 1392 if (ia == NULL) { 1393 type = ICMP_UNREACH; 1394 code = ICMP_UNREACH_SRCFAIL; 1395 goto bad; 1396 } 1397 ip->ip_dst = ipaddr.sin_addr; 1398 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), 1399 sizeof(struct in_addr)); 1400 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1401 /* 1402 * Let ip_intr's mcast routing check handle mcast pkts 1403 */ 1404 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); 1405 break; 1406 1407 case IPOPT_RR: 1408 #ifdef IPSTEALTH 1409 if (ipstealth && pass == 0) 1410 break; 1411 #endif 1412 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1413 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1414 goto bad; 1415 } 1416 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1417 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1418 goto bad; 1419 } 1420 /* 1421 * If no space remains, ignore. 1422 */ 1423 off--; /* 0 origin */ 1424 if (off > optlen - (int)sizeof(struct in_addr)) 1425 break; 1426 (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst, 1427 sizeof(ipaddr.sin_addr)); 1428 /* 1429 * locate outgoing interface; if we're the destination, 1430 * use the incoming interface (should be same). 1431 */ 1432 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL && 1433 (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) { 1434 type = ICMP_UNREACH; 1435 code = ICMP_UNREACH_HOST; 1436 goto bad; 1437 } 1438 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), 1439 sizeof(struct in_addr)); 1440 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1441 break; 1442 1443 case IPOPT_TS: 1444 #ifdef IPSTEALTH 1445 if (ipstealth && pass == 0) 1446 break; 1447 #endif 1448 code = cp - (u_char *)ip; 1449 if (optlen < 4 || optlen > 40) { 1450 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1451 goto bad; 1452 } 1453 if ((off = cp[IPOPT_OFFSET]) < 5) { 1454 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1455 goto bad; 1456 } 1457 if (off > optlen - (int)sizeof(int32_t)) { 1458 cp[IPOPT_OFFSET + 1] += (1 << 4); 1459 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) { 1460 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1461 goto bad; 1462 } 1463 break; 1464 } 1465 off--; /* 0 origin */ 1466 sin = (struct in_addr *)(cp + off); 1467 switch (cp[IPOPT_OFFSET + 1] & 0x0f) { 1468 1469 case IPOPT_TS_TSONLY: 1470 break; 1471 1472 case IPOPT_TS_TSANDADDR: 1473 if (off + sizeof(n_time) + 1474 sizeof(struct in_addr) > optlen) { 1475 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1476 goto bad; 1477 } 1478 ipaddr.sin_addr = dst; 1479 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1480 m->m_pkthdr.rcvif); 1481 if (ia == NULL) 1482 continue; 1483 (void)memcpy(sin, &IA_SIN(ia)->sin_addr, 1484 sizeof(struct in_addr)); 1485 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1486 off += sizeof(struct in_addr); 1487 break; 1488 1489 case IPOPT_TS_PRESPEC: 1490 if (off + sizeof(n_time) + 1491 sizeof(struct in_addr) > optlen) { 1492 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1493 goto bad; 1494 } 1495 (void)memcpy(&ipaddr.sin_addr, sin, 1496 sizeof(struct in_addr)); 1497 if (ifa_ifwithaddr((SA)&ipaddr) == NULL) 1498 continue; 1499 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1500 off += sizeof(struct in_addr); 1501 break; 1502 1503 default: 1504 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip; 1505 goto bad; 1506 } 1507 ntime = iptime(); 1508 (void)memcpy(cp + off, &ntime, sizeof(n_time)); 1509 cp[IPOPT_OFFSET] += sizeof(n_time); 1510 } 1511 } 1512 if (forward && ipforwarding) { 1513 ip_forward(m, 1); 1514 return (1); 1515 } 1516 return (0); 1517 bad: 1518 icmp_error(m, type, code, 0, 0); 1519 ipstat.ips_badoptions++; 1520 return (1); 1521 } 1522 1523 /* 1524 * Given address of next destination (final or next hop), 1525 * return internet address info of interface to be used to get there. 1526 */ 1527 struct in_ifaddr * 1528 ip_rtaddr(dst) 1529 struct in_addr dst; 1530 { 1531 struct route sro; 1532 struct sockaddr_in *sin; 1533 struct in_ifaddr *ifa; 1534 1535 bzero(&sro, sizeof(sro)); 1536 sin = (struct sockaddr_in *)&sro.ro_dst; 1537 sin->sin_family = AF_INET; 1538 sin->sin_len = sizeof(*sin); 1539 sin->sin_addr = dst; 1540 rtalloc_ign(&sro, RTF_CLONING); 1541 1542 if (sro.ro_rt == NULL) 1543 return (NULL); 1544 1545 ifa = ifatoia(sro.ro_rt->rt_ifa); 1546 RTFREE(sro.ro_rt); 1547 return (ifa); 1548 } 1549 1550 /* 1551 * Save incoming source route for use in replies, 1552 * to be picked up later by ip_srcroute if the receiver is interested. 1553 */ 1554 static void 1555 save_rte(m, option, dst) 1556 struct mbuf *m; 1557 u_char *option; 1558 struct in_addr dst; 1559 { 1560 unsigned olen; 1561 struct ipopt_tag *opts; 1562 1563 opts = (struct ipopt_tag *)m_tag_get(PACKET_TAG_IPOPTIONS, 1564 sizeof(struct ipopt_tag), M_NOWAIT); 1565 if (opts == NULL) 1566 return; 1567 1568 olen = option[IPOPT_OLEN]; 1569 #ifdef DIAGNOSTIC 1570 if (ipprintfs) 1571 printf("save_rte: olen %d\n", olen); 1572 #endif 1573 if (olen > sizeof(opts->ip_srcrt) - (1 + sizeof(dst))) { 1574 m_tag_free((struct m_tag *)opts); 1575 return; 1576 } 1577 bcopy(option, opts->ip_srcrt.srcopt, olen); 1578 opts->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1579 opts->ip_srcrt.dst = dst; 1580 m_tag_prepend(m, (struct m_tag *)opts); 1581 } 1582 1583 /* 1584 * Retrieve incoming source route for use in replies, 1585 * in the same form used by setsockopt. 1586 * The first hop is placed before the options, will be removed later. 1587 */ 1588 struct mbuf * 1589 ip_srcroute(m0) 1590 struct mbuf *m0; 1591 { 1592 register struct in_addr *p, *q; 1593 register struct mbuf *m; 1594 struct ipopt_tag *opts; 1595 1596 opts = (struct ipopt_tag *)m_tag_find(m0, PACKET_TAG_IPOPTIONS, NULL); 1597 if (opts == NULL) 1598 return (NULL); 1599 1600 if (opts->ip_nhops == 0) 1601 return (NULL); 1602 m = m_get(M_DONTWAIT, MT_HEADER); 1603 if (m == NULL) 1604 return (NULL); 1605 1606 #define OPTSIZ (sizeof(opts->ip_srcrt.nop) + sizeof(opts->ip_srcrt.srcopt)) 1607 1608 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1609 m->m_len = opts->ip_nhops * sizeof(struct in_addr) + 1610 sizeof(struct in_addr) + OPTSIZ; 1611 #ifdef DIAGNOSTIC 1612 if (ipprintfs) 1613 printf("ip_srcroute: nhops %d mlen %d", opts->ip_nhops, m->m_len); 1614 #endif 1615 1616 /* 1617 * First save first hop for return route 1618 */ 1619 p = &(opts->ip_srcrt.route[opts->ip_nhops - 1]); 1620 *(mtod(m, struct in_addr *)) = *p--; 1621 #ifdef DIAGNOSTIC 1622 if (ipprintfs) 1623 printf(" hops %lx", (u_long)ntohl(mtod(m, struct in_addr *)->s_addr)); 1624 #endif 1625 1626 /* 1627 * Copy option fields and padding (nop) to mbuf. 1628 */ 1629 opts->ip_srcrt.nop = IPOPT_NOP; 1630 opts->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1631 (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), 1632 &(opts->ip_srcrt.nop), OPTSIZ); 1633 q = (struct in_addr *)(mtod(m, caddr_t) + 1634 sizeof(struct in_addr) + OPTSIZ); 1635 #undef OPTSIZ 1636 /* 1637 * Record return path as an IP source route, 1638 * reversing the path (pointers are now aligned). 1639 */ 1640 while (p >= opts->ip_srcrt.route) { 1641 #ifdef DIAGNOSTIC 1642 if (ipprintfs) 1643 printf(" %lx", (u_long)ntohl(q->s_addr)); 1644 #endif 1645 *q++ = *p--; 1646 } 1647 /* 1648 * Last hop goes to final destination. 1649 */ 1650 *q = opts->ip_srcrt.dst; 1651 #ifdef DIAGNOSTIC 1652 if (ipprintfs) 1653 printf(" %lx\n", (u_long)ntohl(q->s_addr)); 1654 #endif 1655 m_tag_delete(m0, (struct m_tag *)opts); 1656 return (m); 1657 } 1658 1659 /* 1660 * Strip out IP options, at higher 1661 * level protocol in the kernel. 1662 * Second argument is buffer to which options 1663 * will be moved, and return value is their length. 1664 * XXX should be deleted; last arg currently ignored. 1665 */ 1666 void 1667 ip_stripoptions(m, mopt) 1668 register struct mbuf *m; 1669 struct mbuf *mopt; 1670 { 1671 register int i; 1672 struct ip *ip = mtod(m, struct ip *); 1673 register caddr_t opts; 1674 int olen; 1675 1676 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1677 opts = (caddr_t)(ip + 1); 1678 i = m->m_len - (sizeof (struct ip) + olen); 1679 bcopy(opts + olen, opts, (unsigned)i); 1680 m->m_len -= olen; 1681 if (m->m_flags & M_PKTHDR) 1682 m->m_pkthdr.len -= olen; 1683 ip->ip_v = IPVERSION; 1684 ip->ip_hl = sizeof(struct ip) >> 2; 1685 } 1686 1687 u_char inetctlerrmap[PRC_NCMDS] = { 1688 0, 0, 0, 0, 1689 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1690 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1691 EMSGSIZE, EHOSTUNREACH, 0, 0, 1692 0, 0, EHOSTUNREACH, 0, 1693 ENOPROTOOPT, ECONNREFUSED 1694 }; 1695 1696 /* 1697 * Forward a packet. If some error occurs return the sender 1698 * an icmp packet. Note we can't always generate a meaningful 1699 * icmp message because icmp doesn't have a large enough repertoire 1700 * of codes and types. 1701 * 1702 * If not forwarding, just drop the packet. This could be confusing 1703 * if ipforwarding was zero but some routing protocol was advancing 1704 * us as a gateway to somewhere. However, we must let the routing 1705 * protocol deal with that. 1706 * 1707 * The srcrt parameter indicates whether the packet is being forwarded 1708 * via a source route. 1709 */ 1710 void 1711 ip_forward(struct mbuf *m, int srcrt) 1712 { 1713 struct ip *ip = mtod(m, struct ip *); 1714 struct in_ifaddr *ia = NULL; 1715 struct mbuf *mcopy; 1716 struct in_addr dest; 1717 int error, type = 0, code = 0, mtu = 0; 1718 1719 #ifdef DIAGNOSTIC 1720 if (ipprintfs) 1721 printf("forward: src %lx dst %lx ttl %x\n", 1722 (u_long)ip->ip_src.s_addr, (u_long)ip->ip_dst.s_addr, 1723 ip->ip_ttl); 1724 #endif 1725 1726 1727 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { 1728 ipstat.ips_cantforward++; 1729 m_freem(m); 1730 return; 1731 } 1732 #ifdef IPSTEALTH 1733 if (!ipstealth) { 1734 #endif 1735 if (ip->ip_ttl <= IPTTLDEC) { 1736 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 1737 0, 0); 1738 return; 1739 } 1740 #ifdef IPSTEALTH 1741 } 1742 #endif 1743 1744 if (!srcrt && (ia = ip_rtaddr(ip->ip_dst)) == NULL) { 1745 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0); 1746 return; 1747 } 1748 1749 /* 1750 * Save the IP header and at most 8 bytes of the payload, 1751 * in case we need to generate an ICMP message to the src. 1752 * 1753 * XXX this can be optimized a lot by saving the data in a local 1754 * buffer on the stack (72 bytes at most), and only allocating the 1755 * mbuf if really necessary. The vast majority of the packets 1756 * are forwarded without having to send an ICMP back (either 1757 * because unnecessary, or because rate limited), so we are 1758 * really we are wasting a lot of work here. 1759 * 1760 * We don't use m_copy() because it might return a reference 1761 * to a shared cluster. Both this function and ip_output() 1762 * assume exclusive access to the IP header in `m', so any 1763 * data in a cluster may change before we reach icmp_error(). 1764 */ 1765 MGET(mcopy, M_DONTWAIT, m->m_type); 1766 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) { 1767 /* 1768 * It's probably ok if the pkthdr dup fails (because 1769 * the deep copy of the tag chain failed), but for now 1770 * be conservative and just discard the copy since 1771 * code below may some day want the tags. 1772 */ 1773 m_free(mcopy); 1774 mcopy = NULL; 1775 } 1776 if (mcopy != NULL) { 1777 mcopy->m_len = imin((ip->ip_hl << 2) + 8, 1778 (int)ip->ip_len); 1779 mcopy->m_pkthdr.len = mcopy->m_len; 1780 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t)); 1781 } 1782 1783 #ifdef IPSTEALTH 1784 if (!ipstealth) { 1785 #endif 1786 ip->ip_ttl -= IPTTLDEC; 1787 #ifdef IPSTEALTH 1788 } 1789 #endif 1790 1791 /* 1792 * If forwarding packet using same interface that it came in on, 1793 * perhaps should send a redirect to sender to shortcut a hop. 1794 * Only send redirect if source is sending directly to us, 1795 * and if packet was not source routed (or has any options). 1796 * Also, don't send redirect if forwarding using a default route 1797 * or a route modified by a redirect. 1798 */ 1799 dest.s_addr = 0; 1800 if (!srcrt && ipsendredirects && ia->ia_ifp == m->m_pkthdr.rcvif) { 1801 struct sockaddr_in *sin; 1802 struct route ro; 1803 struct rtentry *rt; 1804 1805 bzero(&ro, sizeof(ro)); 1806 sin = (struct sockaddr_in *)&ro.ro_dst; 1807 sin->sin_family = AF_INET; 1808 sin->sin_len = sizeof(*sin); 1809 sin->sin_addr = ip->ip_dst; 1810 rtalloc_ign(&ro, RTF_CLONING); 1811 1812 rt = ro.ro_rt; 1813 1814 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1815 satosin(rt_key(rt))->sin_addr.s_addr != 0) { 1816 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa)) 1817 u_long src = ntohl(ip->ip_src.s_addr); 1818 1819 if (RTA(rt) && 1820 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) { 1821 if (rt->rt_flags & RTF_GATEWAY) 1822 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr; 1823 else 1824 dest.s_addr = ip->ip_dst.s_addr; 1825 /* Router requirements says to only send host redirects */ 1826 type = ICMP_REDIRECT; 1827 code = ICMP_REDIRECT_HOST; 1828 #ifdef DIAGNOSTIC 1829 if (ipprintfs) 1830 printf("redirect (%d) to %lx\n", code, (u_long)dest.s_addr); 1831 #endif 1832 } 1833 } 1834 if (rt) 1835 RTFREE(rt); 1836 } 1837 1838 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); 1839 if (error) 1840 ipstat.ips_cantforward++; 1841 else { 1842 ipstat.ips_forward++; 1843 if (type) 1844 ipstat.ips_redirectsent++; 1845 else { 1846 if (mcopy) 1847 m_freem(mcopy); 1848 return; 1849 } 1850 } 1851 if (mcopy == NULL) 1852 return; 1853 1854 switch (error) { 1855 1856 case 0: /* forwarded, but need redirect */ 1857 /* type, code set above */ 1858 break; 1859 1860 case ENETUNREACH: /* shouldn't happen, checked above */ 1861 case EHOSTUNREACH: 1862 case ENETDOWN: 1863 case EHOSTDOWN: 1864 default: 1865 type = ICMP_UNREACH; 1866 code = ICMP_UNREACH_HOST; 1867 break; 1868 1869 case EMSGSIZE: 1870 type = ICMP_UNREACH; 1871 code = ICMP_UNREACH_NEEDFRAG; 1872 #if defined(IPSEC) || defined(FAST_IPSEC) 1873 /* 1874 * If the packet is routed over IPsec tunnel, tell the 1875 * originator the tunnel MTU. 1876 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 1877 * XXX quickhack!!! 1878 */ 1879 { 1880 struct secpolicy *sp = NULL; 1881 int ipsecerror; 1882 int ipsechdr; 1883 struct route *ro; 1884 1885 #ifdef IPSEC 1886 sp = ipsec4_getpolicybyaddr(mcopy, 1887 IPSEC_DIR_OUTBOUND, 1888 IP_FORWARDING, 1889 &ipsecerror); 1890 #else /* FAST_IPSEC */ 1891 sp = ipsec_getpolicybyaddr(mcopy, 1892 IPSEC_DIR_OUTBOUND, 1893 IP_FORWARDING, 1894 &ipsecerror); 1895 #endif 1896 if (sp != NULL) { 1897 /* count IPsec header size */ 1898 ipsechdr = ipsec4_hdrsiz(mcopy, 1899 IPSEC_DIR_OUTBOUND, 1900 NULL); 1901 1902 /* 1903 * find the correct route for outer IPv4 1904 * header, compute tunnel MTU. 1905 */ 1906 if (sp->req != NULL 1907 && sp->req->sav != NULL 1908 && sp->req->sav->sah != NULL) { 1909 ro = &sp->req->sav->sah->sa_route; 1910 if (ro->ro_rt && ro->ro_rt->rt_ifp) { 1911 mtu = 1912 ro->ro_rt->rt_rmx.rmx_mtu ? 1913 ro->ro_rt->rt_rmx.rmx_mtu : 1914 ro->ro_rt->rt_ifp->if_mtu; 1915 mtu -= ipsechdr; 1916 } 1917 } 1918 1919 #ifdef IPSEC 1920 key_freesp(sp); 1921 #else /* FAST_IPSEC */ 1922 KEY_FREESP(&sp); 1923 #endif 1924 ipstat.ips_cantfrag++; 1925 break; 1926 } else 1927 #endif /*IPSEC || FAST_IPSEC*/ 1928 /* 1929 * When doing source routing 'ia' can be NULL. Fall back 1930 * to the minimum guaranteed routeable packet size and use 1931 * the same hack as IPSEC to setup a dummyifp for icmp. 1932 */ 1933 if (ia == NULL) 1934 mtu = IP_MSS; 1935 else 1936 mtu = ia->ia_ifp->if_mtu; 1937 #if defined(IPSEC) || defined(FAST_IPSEC) 1938 } 1939 #endif /*IPSEC || FAST_IPSEC*/ 1940 ipstat.ips_cantfrag++; 1941 break; 1942 1943 case ENOBUFS: 1944 /* 1945 * A router should not generate ICMP_SOURCEQUENCH as 1946 * required in RFC1812 Requirements for IP Version 4 Routers. 1947 * Source quench could be a big problem under DoS attacks, 1948 * or if the underlying interface is rate-limited. 1949 * Those who need source quench packets may re-enable them 1950 * via the net.inet.ip.sendsourcequench sysctl. 1951 */ 1952 if (ip_sendsourcequench == 0) { 1953 m_freem(mcopy); 1954 return; 1955 } else { 1956 type = ICMP_SOURCEQUENCH; 1957 code = 0; 1958 } 1959 break; 1960 1961 case EACCES: /* ipfw denied packet */ 1962 m_freem(mcopy); 1963 return; 1964 } 1965 icmp_error(mcopy, type, code, dest.s_addr, mtu); 1966 } 1967 1968 void 1969 ip_savecontrol(inp, mp, ip, m) 1970 register struct inpcb *inp; 1971 register struct mbuf **mp; 1972 register struct ip *ip; 1973 register struct mbuf *m; 1974 { 1975 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) { 1976 struct bintime bt; 1977 1978 bintime(&bt); 1979 if (inp->inp_socket->so_options & SO_BINTIME) { 1980 *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt), 1981 SCM_BINTIME, SOL_SOCKET); 1982 if (*mp) 1983 mp = &(*mp)->m_next; 1984 } 1985 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1986 struct timeval tv; 1987 1988 bintime2timeval(&bt, &tv); 1989 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1990 SCM_TIMESTAMP, SOL_SOCKET); 1991 if (*mp) 1992 mp = &(*mp)->m_next; 1993 } 1994 } 1995 if (inp->inp_flags & INP_RECVDSTADDR) { 1996 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1997 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1998 if (*mp) 1999 mp = &(*mp)->m_next; 2000 } 2001 if (inp->inp_flags & INP_RECVTTL) { 2002 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, 2003 sizeof(u_char), IP_RECVTTL, IPPROTO_IP); 2004 if (*mp) 2005 mp = &(*mp)->m_next; 2006 } 2007 #ifdef notyet 2008 /* XXX 2009 * Moving these out of udp_input() made them even more broken 2010 * than they already were. 2011 */ 2012 /* options were tossed already */ 2013 if (inp->inp_flags & INP_RECVOPTS) { 2014 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 2015 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 2016 if (*mp) 2017 mp = &(*mp)->m_next; 2018 } 2019 /* ip_srcroute doesn't do what we want here, need to fix */ 2020 if (inp->inp_flags & INP_RECVRETOPTS) { 2021 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m), 2022 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 2023 if (*mp) 2024 mp = &(*mp)->m_next; 2025 } 2026 #endif 2027 if (inp->inp_flags & INP_RECVIF) { 2028 struct ifnet *ifp; 2029 struct sdlbuf { 2030 struct sockaddr_dl sdl; 2031 u_char pad[32]; 2032 } sdlbuf; 2033 struct sockaddr_dl *sdp; 2034 struct sockaddr_dl *sdl2 = &sdlbuf.sdl; 2035 2036 if (((ifp = m->m_pkthdr.rcvif)) 2037 && ( ifp->if_index && (ifp->if_index <= if_index))) { 2038 sdp = (struct sockaddr_dl *) 2039 (ifaddr_byindex(ifp->if_index)->ifa_addr); 2040 /* 2041 * Change our mind and don't try copy. 2042 */ 2043 if ((sdp->sdl_family != AF_LINK) 2044 || (sdp->sdl_len > sizeof(sdlbuf))) { 2045 goto makedummy; 2046 } 2047 bcopy(sdp, sdl2, sdp->sdl_len); 2048 } else { 2049 makedummy: 2050 sdl2->sdl_len 2051 = offsetof(struct sockaddr_dl, sdl_data[0]); 2052 sdl2->sdl_family = AF_LINK; 2053 sdl2->sdl_index = 0; 2054 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; 2055 } 2056 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len, 2057 IP_RECVIF, IPPROTO_IP); 2058 if (*mp) 2059 mp = &(*mp)->m_next; 2060 } 2061 } 2062 2063 /* 2064 * XXX these routines are called from the upper part of the kernel. 2065 * They need to be locked when we remove Giant. 2066 * 2067 * They could also be moved to ip_mroute.c, since all the RSVP 2068 * handling is done there already. 2069 */ 2070 static int ip_rsvp_on; 2071 struct socket *ip_rsvpd; 2072 int 2073 ip_rsvp_init(struct socket *so) 2074 { 2075 if (so->so_type != SOCK_RAW || 2076 so->so_proto->pr_protocol != IPPROTO_RSVP) 2077 return EOPNOTSUPP; 2078 2079 if (ip_rsvpd != NULL) 2080 return EADDRINUSE; 2081 2082 ip_rsvpd = so; 2083 /* 2084 * This may seem silly, but we need to be sure we don't over-increment 2085 * the RSVP counter, in case something slips up. 2086 */ 2087 if (!ip_rsvp_on) { 2088 ip_rsvp_on = 1; 2089 rsvp_on++; 2090 } 2091 2092 return 0; 2093 } 2094 2095 int 2096 ip_rsvp_done(void) 2097 { 2098 ip_rsvpd = NULL; 2099 /* 2100 * This may seem silly, but we need to be sure we don't over-decrement 2101 * the RSVP counter, in case something slips up. 2102 */ 2103 if (ip_rsvp_on) { 2104 ip_rsvp_on = 0; 2105 rsvp_on--; 2106 } 2107 return 0; 2108 } 2109 2110 void 2111 rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */ 2112 { 2113 if (rsvp_input_p) { /* call the real one if loaded */ 2114 rsvp_input_p(m, off); 2115 return; 2116 } 2117 2118 /* Can still get packets with rsvp_on = 0 if there is a local member 2119 * of the group to which the RSVP packet is addressed. But in this 2120 * case we want to throw the packet away. 2121 */ 2122 2123 if (!rsvp_on) { 2124 m_freem(m); 2125 return; 2126 } 2127 2128 if (ip_rsvpd != NULL) { 2129 rip_input(m, off); 2130 return; 2131 } 2132 /* Drop the packet */ 2133 m_freem(m); 2134 } 2135