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sys/netinet/ip_input.c
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1 /* 2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Jeffrey M. Hsu. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of The DragonFly Project nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific, prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 63 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $ 64 */ 65 66 #define _IP_VHL 67 68 #include "opt_bootp.h" 69 #include "opt_ipdn.h" 70 #include "opt_ipdivert.h" 71 #include "opt_ipstealth.h" 72 #include "opt_ipsec.h" 73 #include "opt_rss.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/mbuf.h> 78 #include <sys/malloc.h> 79 #include <sys/mpipe.h> 80 #include <sys/domain.h> 81 #include <sys/protosw.h> 82 #include <sys/socket.h> 83 #include <sys/time.h> 84 #include <sys/globaldata.h> 85 #include <sys/thread.h> 86 #include <sys/kernel.h> 87 #include <sys/syslog.h> 88 #include <sys/sysctl.h> 89 #include <sys/in_cksum.h> 90 #include <sys/lock.h> 91 92 #include <sys/mplock2.h> 93 94 #include <machine/stdarg.h> 95 96 #include <net/if.h> 97 #include <net/if_types.h> 98 #include <net/if_var.h> 99 #include <net/if_dl.h> 100 #include <net/pfil.h> 101 #include <net/route.h> 102 #include <net/netisr2.h> 103 104 #include <netinet/in.h> 105 #include <netinet/in_systm.h> 106 #include <netinet/in_var.h> 107 #include <netinet/ip.h> 108 #include <netinet/in_pcb.h> 109 #include <netinet/ip_var.h> 110 #include <netinet/ip_icmp.h> 111 #include <netinet/ip_divert.h> 112 #include <netinet/ip_flow.h> 113 114 #include <sys/thread2.h> 115 #include <sys/msgport2.h> 116 #include <net/netmsg2.h> 117 118 #include <sys/socketvar.h> 119 120 #include <net/ipfw/ip_fw.h> 121 #include <net/dummynet/ip_dummynet.h> 122 123 #ifdef IPSEC 124 #include <netinet6/ipsec.h> 125 #include <netproto/key/key.h> 126 #endif 127 128 #ifdef FAST_IPSEC 129 #include <netproto/ipsec/ipsec.h> 130 #include <netproto/ipsec/key.h> 131 #endif 132 133 int rsvp_on = 0; 134 static int ip_rsvp_on; 135 struct socket *ip_rsvpd; 136 137 int ipforwarding = 0; 138 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, 139 &ipforwarding, 0, "Enable IP forwarding between interfaces"); 140 141 static int ipsendredirects = 1; /* XXX */ 142 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, 143 &ipsendredirects, 0, "Enable sending IP redirects"); 144 145 int ip_defttl = IPDEFTTL; 146 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW, 147 &ip_defttl, 0, "Maximum TTL on IP packets"); 148 149 static int ip_dosourceroute = 0; 150 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW, 151 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets"); 152 153 static int ip_acceptsourceroute = 0; 154 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, 155 CTLFLAG_RW, &ip_acceptsourceroute, 0, 156 "Enable accepting source routed IP packets"); 157 158 static int ip_keepfaith = 0; 159 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW, 160 &ip_keepfaith, 0, 161 "Enable packet capture for FAITH IPv4->IPv6 translator daemon"); 162 163 static int nipq = 0; /* total # of reass queues */ 164 static int maxnipq; 165 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW, 166 &maxnipq, 0, 167 "Maximum number of IPv4 fragment reassembly queue entries"); 168 169 static int maxfragsperpacket; 170 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, 171 &maxfragsperpacket, 0, 172 "Maximum number of IPv4 fragments allowed per packet"); 173 174 static int ip_sendsourcequench = 0; 175 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, 176 &ip_sendsourcequench, 0, 177 "Enable the transmission of source quench packets"); 178 179 int ip_do_randomid = 1; 180 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, 181 &ip_do_randomid, 0, 182 "Assign random ip_id values"); 183 /* 184 * XXX - Setting ip_checkinterface mostly implements the receive side of 185 * the Strong ES model described in RFC 1122, but since the routing table 186 * and transmit implementation do not implement the Strong ES model, 187 * setting this to 1 results in an odd hybrid. 188 * 189 * XXX - ip_checkinterface currently must be disabled if you use ipnat 190 * to translate the destination address to another local interface. 191 * 192 * XXX - ip_checkinterface must be disabled if you add IP aliases 193 * to the loopback interface instead of the interface where the 194 * packets for those addresses are received. 195 */ 196 static int ip_checkinterface = 0; 197 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, 198 &ip_checkinterface, 0, "Verify packet arrives on correct interface"); 199 200 static u_long ip_hash_count = 0; 201 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD, 202 &ip_hash_count, 0, "Number of packets hashed by IP"); 203 204 #ifdef RSS_DEBUG 205 static u_long ip_rehash_count = 0; 206 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD, 207 &ip_rehash_count, 0, "Number of packets rehashed by IP"); 208 209 static u_long ip_dispatch_fast = 0; 210 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD, 211 &ip_dispatch_fast, 0, "Number of packets handled on current CPU"); 212 213 static u_long ip_dispatch_slow = 0; 214 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD, 215 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU"); 216 #endif 217 218 static struct lwkt_token ipq_token = LWKT_TOKEN_INITIALIZER(ipq_token); 219 220 #ifdef DIAGNOSTIC 221 static int ipprintfs = 0; 222 #endif 223 224 extern struct domain inetdomain; 225 extern struct protosw inetsw[]; 226 u_char ip_protox[IPPROTO_MAX]; 227 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */ 228 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU]; 229 /* inet addr hash table */ 230 u_long in_ifaddrhmask; /* mask for hash table */ 231 232 static struct mbuf *ipforward_mtemp[MAXCPU]; 233 234 struct ip_stats ipstats_percpu[MAXCPU] __cachealign; 235 236 static int 237 sysctl_ipstats(SYSCTL_HANDLER_ARGS) 238 { 239 int cpu, error = 0; 240 241 for (cpu = 0; cpu < ncpus; ++cpu) { 242 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu], 243 sizeof(struct ip_stats)))) 244 break; 245 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu], 246 sizeof(struct ip_stats)))) 247 break; 248 } 249 250 return (error); 251 } 252 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 253 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics"); 254 255 /* Packet reassembly stuff */ 256 #define IPREASS_NHASH_LOG2 6 257 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) 258 #define IPREASS_HMASK (IPREASS_NHASH - 1) 259 #define IPREASS_HASH(x,y) \ 260 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK) 261 262 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH]; 263 264 #ifdef IPCTL_DEFMTU 265 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, 266 &ip_mtu, 0, "Default MTU"); 267 #endif 268 269 #ifdef IPSTEALTH 270 static int ipstealth = 0; 271 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, ""); 272 #else 273 static const int ipstealth = 0; 274 #endif 275 276 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int); 277 278 struct pfil_head inet_pfil_hook; 279 280 /* 281 * struct ip_srcrt_opt is used to store packet state while it travels 282 * through the stack. 283 * 284 * XXX Note that the code even makes assumptions on the size and 285 * alignment of fields inside struct ip_srcrt so e.g. adding some 286 * fields will break the code. This needs to be fixed. 287 * 288 * We need to save the IP options in case a protocol wants to respond 289 * to an incoming packet over the same route if the packet got here 290 * using IP source routing. This allows connection establishment and 291 * maintenance when the remote end is on a network that is not known 292 * to us. 293 */ 294 struct ip_srcrt { 295 struct in_addr dst; /* final destination */ 296 char nop; /* one NOP to align */ 297 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 298 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 299 }; 300 301 struct ip_srcrt_opt { 302 int ip_nhops; 303 struct ip_srcrt ip_srcrt; 304 }; 305 306 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management"); 307 static struct malloc_pipe ipq_mpipe; 308 309 static void save_rte(struct mbuf *, u_char *, struct in_addr); 310 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *); 311 static void ip_freef(struct ipqhead *, struct ipq *); 312 static void ip_input_handler(netmsg_t); 313 314 /* 315 * IP initialization: fill in IP protocol switch table. 316 * All protocols not implemented in kernel go to raw IP protocol handler. 317 */ 318 void 319 ip_init(void) 320 { 321 struct protosw *pr; 322 int i; 323 int cpu; 324 325 /* 326 * Make sure we can handle a reasonable number of fragments but 327 * cap it at 4000 (XXX). 328 */ 329 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq), 330 IFQ_MAXLEN, 4000, 0, NULL, NULL, NULL); 331 for (i = 0; i < ncpus; ++i) { 332 TAILQ_INIT(&in_ifaddrheads[i]); 333 in_ifaddrhashtbls[i] = 334 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask); 335 } 336 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 337 if (pr == NULL) 338 panic("ip_init"); 339 for (i = 0; i < IPPROTO_MAX; i++) 340 ip_protox[i] = pr - inetsw; 341 for (pr = inetdomain.dom_protosw; 342 pr < inetdomain.dom_protoswNPROTOSW; pr++) { 343 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) { 344 if (pr->pr_protocol != IPPROTO_RAW) 345 ip_protox[pr->pr_protocol] = pr - inetsw; 346 } 347 } 348 349 inet_pfil_hook.ph_type = PFIL_TYPE_AF; 350 inet_pfil_hook.ph_af = AF_INET; 351 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) { 352 kprintf("%s: WARNING: unable to register pfil hook, " 353 "error %d\n", __func__, i); 354 } 355 356 for (i = 0; i < IPREASS_NHASH; i++) 357 TAILQ_INIT(&ipq[i]); 358 359 maxnipq = nmbclusters / 32; 360 maxfragsperpacket = 16; 361 362 ip_id = time_second & 0xffff; /* time_second survives reboots */ 363 364 for (cpu = 0; cpu < ncpus; ++cpu) { 365 /* 366 * Initialize IP statistics counters for each CPU. 367 */ 368 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats)); 369 370 /* 371 * Preallocate mbuf template for forwarding 372 */ 373 MGETHDR(ipforward_mtemp[cpu], MB_WAIT, MT_DATA); 374 } 375 376 netisr_register(NETISR_IP, ip_input_handler, ip_hashfn_in); 377 netisr_register_hashcheck(NETISR_IP, ip_hashcheck); 378 } 379 380 /* Do transport protocol processing. */ 381 static void 382 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip) 383 { 384 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]]; 385 386 /* 387 * Switch out to protocol's input routine. 388 */ 389 PR_GET_MPLOCK(pr); 390 pr->pr_input(&m, &hlen, ip->ip_p); 391 PR_REL_MPLOCK(pr); 392 } 393 394 static void 395 transport_processing_handler(netmsg_t msg) 396 { 397 struct netmsg_packet *pmsg = &msg->packet; 398 struct ip *ip; 399 int hlen; 400 401 ip = mtod(pmsg->nm_packet, struct ip *); 402 hlen = pmsg->base.lmsg.u.ms_result; 403 404 transport_processing_oncpu(pmsg->nm_packet, hlen, ip); 405 /* msg was embedded in the mbuf, do not reply! */ 406 } 407 408 static void 409 ip_input_handler(netmsg_t msg) 410 { 411 ip_input(msg->packet.nm_packet); 412 /* msg was embedded in the mbuf, do not reply! */ 413 } 414 415 /* 416 * IP input routine. Checksum and byte swap header. If fragmented 417 * try to reassemble. Process options. Pass to next level. 418 */ 419 void 420 ip_input(struct mbuf *m) 421 { 422 struct ip *ip; 423 struct in_ifaddr *ia = NULL; 424 struct in_ifaddr_container *iac; 425 int hlen, checkif; 426 u_short sum; 427 struct in_addr pkt_dst; 428 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */ 429 struct in_addr odst; /* original dst address(NAT) */ 430 struct m_tag *mtag; 431 struct sockaddr_in *next_hop = NULL; 432 lwkt_port_t port; 433 #ifdef FAST_IPSEC 434 struct tdb_ident *tdbi; 435 struct secpolicy *sp; 436 int error; 437 #endif 438 439 M_ASSERTPKTHDR(m); 440 441 /* 442 * This routine is called from numerous places which may not have 443 * characterized the packet. 444 */ 445 if ((m->m_flags & M_HASH) == 0) { 446 atomic_add_long(&ip_hash_count, 1); 447 ip_hashfn(&m, 0, IP_MPORT_IN); 448 if (m == NULL) 449 return; 450 KKASSERT(m->m_flags & M_HASH); 451 } 452 ip = mtod(m, struct ip *); 453 454 /* 455 * Pull out certain tags 456 */ 457 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 458 /* Next hop */ 459 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 460 KKASSERT(mtag != NULL); 461 next_hop = m_tag_data(mtag); 462 } 463 464 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 465 /* dummynet already filtered us */ 466 ip = mtod(m, struct ip *); 467 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 468 goto iphack; 469 } 470 471 ipstat.ips_total++; 472 473 /* length checks already done in ip_hashfn() */ 474 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf")); 475 476 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) { 477 ipstat.ips_badvers++; 478 goto bad; 479 } 480 481 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 482 /* length checks already done in ip_hashfn() */ 483 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small")); 484 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf")); 485 486 /* 127/8 must not appear on wire - RFC1122 */ 487 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 488 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 489 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) { 490 ipstat.ips_badaddr++; 491 goto bad; 492 } 493 } 494 495 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { 496 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); 497 } else { 498 if (hlen == sizeof(struct ip)) 499 sum = in_cksum_hdr(ip); 500 else 501 sum = in_cksum(m, hlen); 502 } 503 if (sum != 0) { 504 ipstat.ips_badsum++; 505 goto bad; 506 } 507 508 #ifdef ALTQ 509 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) { 510 /* packet is dropped by traffic conditioner */ 511 return; 512 } 513 #endif 514 /* 515 * Convert fields to host representation. 516 */ 517 ip->ip_len = ntohs(ip->ip_len); 518 ip->ip_off = ntohs(ip->ip_off); 519 520 /* length checks already done in ip_hashfn() */ 521 KASSERT(ip->ip_len >= hlen, ("total length less then header length")); 522 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short")); 523 524 /* 525 * Trim mbufs if longer than the IP header would have us expect. 526 */ 527 if (m->m_pkthdr.len > ip->ip_len) { 528 if (m->m_len == m->m_pkthdr.len) { 529 m->m_len = ip->ip_len; 530 m->m_pkthdr.len = ip->ip_len; 531 } else { 532 m_adj(m, ip->ip_len - m->m_pkthdr.len); 533 } 534 } 535 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF) 536 /* 537 * Bypass packet filtering for packets from a tunnel (gif). 538 */ 539 if (ipsec_gethist(m, NULL)) 540 goto pass; 541 #endif 542 543 /* 544 * IpHack's section. 545 * Right now when no processing on packet has done 546 * and it is still fresh out of network we do our black 547 * deals with it. 548 * - Firewall: deny/allow/divert 549 * - Xlate: translate packet's addr/port (NAT). 550 * - Pipe: pass pkt through dummynet. 551 * - Wrap: fake packet's addr/port <unimpl.> 552 * - Encapsulate: put it in another IP and send out. <unimp.> 553 */ 554 555 iphack: 556 /* 557 * If we've been forwarded from the output side, then 558 * skip the firewall a second time 559 */ 560 if (next_hop != NULL) 561 goto ours; 562 563 /* No pfil hooks */ 564 if (!pfil_has_hooks(&inet_pfil_hook)) { 565 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 566 /* 567 * Strip dummynet tags from stranded packets 568 */ 569 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 570 KKASSERT(mtag != NULL); 571 m_tag_delete(m, mtag); 572 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 573 } 574 goto pass; 575 } 576 577 /* 578 * Run through list of hooks for input packets. 579 * 580 * NOTE! If the packet is rewritten pf/ipfw/whoever must 581 * clear M_HASH. 582 */ 583 odst = ip->ip_dst; 584 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 585 return; 586 if (m == NULL) /* consumed by filter */ 587 return; 588 ip = mtod(m, struct ip *); 589 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 590 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr); 591 592 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 593 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 594 KKASSERT(mtag != NULL); 595 next_hop = m_tag_data(mtag); 596 } 597 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 598 ip_dn_queue(m); 599 return; 600 } 601 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) { 602 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH; 603 } 604 pass: 605 /* 606 * Process options and, if not destined for us, 607 * ship it on. ip_dooptions returns 1 when an 608 * error was detected (causing an icmp message 609 * to be sent and the original packet to be freed). 610 */ 611 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop)) 612 return; 613 614 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no 615 * matter if it is destined to another node, or whether it is 616 * a multicast one, RSVP wants it! and prevents it from being forwarded 617 * anywhere else. Also checks if the rsvp daemon is running before 618 * grabbing the packet. 619 */ 620 if (rsvp_on && ip->ip_p == IPPROTO_RSVP) 621 goto ours; 622 623 /* 624 * Check our list of addresses, to see if the packet is for us. 625 * If we don't have any addresses, assume any unicast packet 626 * we receive might be for us (and let the upper layers deal 627 * with it). 628 */ 629 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) && 630 !(m->m_flags & (M_MCAST | M_BCAST))) 631 goto ours; 632 633 /* 634 * Cache the destination address of the packet; this may be 635 * changed by use of 'ipfw fwd'. 636 */ 637 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 638 639 /* 640 * Enable a consistency check between the destination address 641 * and the arrival interface for a unicast packet (the RFC 1122 642 * strong ES model) if IP forwarding is disabled and the packet 643 * is not locally generated and the packet is not subject to 644 * 'ipfw fwd'. 645 * 646 * XXX - Checking also should be disabled if the destination 647 * address is ipnat'ed to a different interface. 648 * 649 * XXX - Checking is incompatible with IP aliases added 650 * to the loopback interface instead of the interface where 651 * the packets are received. 652 */ 653 checkif = ip_checkinterface && 654 !ipforwarding && 655 m->m_pkthdr.rcvif != NULL && 656 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 657 next_hop == NULL; 658 659 /* 660 * Check for exact addresses in the hash bucket. 661 */ 662 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) { 663 ia = iac->ia; 664 665 /* 666 * If the address matches, verify that the packet 667 * arrived via the correct interface if checking is 668 * enabled. 669 */ 670 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr && 671 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) 672 goto ours; 673 } 674 ia = NULL; 675 676 /* 677 * Check for broadcast addresses. 678 * 679 * Only accept broadcast packets that arrive via the matching 680 * interface. Reception of forwarded directed broadcasts would 681 * be handled via ip_forward() and ether_output() with the loopback 682 * into the stack for SIMPLEX interfaces handled by ether_output(). 683 */ 684 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 685 struct ifaddr_container *ifac; 686 687 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid], 688 ifa_link) { 689 struct ifaddr *ifa = ifac->ifa; 690 691 if (ifa->ifa_addr == NULL) /* shutdown/startup race */ 692 continue; 693 if (ifa->ifa_addr->sa_family != AF_INET) 694 continue; 695 ia = ifatoia(ifa); 696 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 697 pkt_dst.s_addr) 698 goto ours; 699 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr) 700 goto ours; 701 #ifdef BOOTP_COMPAT 702 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) 703 goto ours; 704 #endif 705 } 706 } 707 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 708 struct in_multi *inm; 709 710 /* XXX Multicast is not MPSAFE yet */ 711 get_mplock(); 712 713 if (ip_mrouter != NULL) { 714 /* 715 * If we are acting as a multicast router, all 716 * incoming multicast packets are passed to the 717 * kernel-level multicast forwarding function. 718 * The packet is returned (relatively) intact; if 719 * ip_mforward() returns a non-zero value, the packet 720 * must be discarded, else it may be accepted below. 721 */ 722 if (ip_mforward != NULL && 723 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) { 724 rel_mplock(); 725 ipstat.ips_cantforward++; 726 m_freem(m); 727 return; 728 } 729 730 /* 731 * The process-level routing daemon needs to receive 732 * all multicast IGMP packets, whether or not this 733 * host belongs to their destination groups. 734 */ 735 if (ip->ip_p == IPPROTO_IGMP) { 736 rel_mplock(); 737 goto ours; 738 } 739 ipstat.ips_forward++; 740 } 741 /* 742 * See if we belong to the destination multicast group on the 743 * arrival interface. 744 */ 745 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 746 if (inm == NULL) { 747 rel_mplock(); 748 ipstat.ips_notmember++; 749 m_freem(m); 750 return; 751 } 752 753 rel_mplock(); 754 goto ours; 755 } 756 if (ip->ip_dst.s_addr == INADDR_BROADCAST) 757 goto ours; 758 if (ip->ip_dst.s_addr == INADDR_ANY) 759 goto ours; 760 761 /* 762 * FAITH(Firewall Aided Internet Translator) 763 */ 764 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { 765 if (ip_keepfaith) { 766 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP) 767 goto ours; 768 } 769 m_freem(m); 770 return; 771 } 772 773 /* 774 * Not for us; forward if possible and desirable. 775 */ 776 if (!ipforwarding) { 777 ipstat.ips_cantforward++; 778 m_freem(m); 779 } else { 780 #ifdef IPSEC 781 /* 782 * Enforce inbound IPsec SPD. 783 */ 784 if (ipsec4_in_reject(m, NULL)) { 785 ipsecstat.in_polvio++; 786 goto bad; 787 } 788 #endif 789 #ifdef FAST_IPSEC 790 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 791 crit_enter(); 792 if (mtag != NULL) { 793 tdbi = (struct tdb_ident *)m_tag_data(mtag); 794 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 795 } else { 796 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 797 IP_FORWARDING, &error); 798 } 799 if (sp == NULL) { /* NB: can happen if error */ 800 crit_exit(); 801 /*XXX error stat???*/ 802 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/ 803 goto bad; 804 } 805 806 /* 807 * Check security policy against packet attributes. 808 */ 809 error = ipsec_in_reject(sp, m); 810 KEY_FREESP(&sp); 811 crit_exit(); 812 if (error) { 813 ipstat.ips_cantforward++; 814 goto bad; 815 } 816 #endif 817 ip_forward(m, using_srcrt, next_hop); 818 } 819 return; 820 821 ours: 822 823 /* 824 * IPSTEALTH: Process non-routing options only 825 * if the packet is destined for us. 826 */ 827 if (ipstealth && 828 hlen > sizeof(struct ip) && 829 ip_dooptions(m, 1, next_hop)) 830 return; 831 832 /* Count the packet in the ip address stats */ 833 if (ia != NULL) { 834 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1); 835 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len); 836 } 837 838 /* 839 * If offset or IP_MF are set, must reassemble. 840 * Otherwise, nothing need be done. 841 * (We could look in the reassembly queue to see 842 * if the packet was previously fragmented, 843 * but it's not worth the time; just let them time out.) 844 */ 845 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 846 /* 847 * Attempt reassembly; if it succeeds, proceed. ip_reass() 848 * will return a different mbuf. 849 * 850 * NOTE: ip_reass() returns m with M_HASH cleared to force 851 * us to recharacterize the packet. 852 */ 853 m = ip_reass(m); 854 if (m == NULL) 855 return; 856 ip = mtod(m, struct ip *); 857 858 /* Get the header length of the reassembled packet */ 859 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 860 } else { 861 ip->ip_len -= hlen; 862 } 863 864 #ifdef IPSEC 865 /* 866 * enforce IPsec policy checking if we are seeing last header. 867 * note that we do not visit this with protocols with pcb layer 868 * code - like udp/tcp/raw ip. 869 */ 870 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) && 871 ipsec4_in_reject(m, NULL)) { 872 ipsecstat.in_polvio++; 873 goto bad; 874 } 875 #endif 876 #if FAST_IPSEC 877 /* 878 * enforce IPsec policy checking if we are seeing last header. 879 * note that we do not visit this with protocols with pcb layer 880 * code - like udp/tcp/raw ip. 881 */ 882 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) { 883 /* 884 * Check if the packet has already had IPsec processing 885 * done. If so, then just pass it along. This tag gets 886 * set during AH, ESP, etc. input handling, before the 887 * packet is returned to the ip input queue for delivery. 888 */ 889 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 890 crit_enter(); 891 if (mtag != NULL) { 892 tdbi = (struct tdb_ident *)m_tag_data(mtag); 893 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 894 } else { 895 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 896 IP_FORWARDING, &error); 897 } 898 if (sp != NULL) { 899 /* 900 * Check security policy against packet attributes. 901 */ 902 error = ipsec_in_reject(sp, m); 903 KEY_FREESP(&sp); 904 } else { 905 /* XXX error stat??? */ 906 error = EINVAL; 907 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/ 908 goto bad; 909 } 910 crit_exit(); 911 if (error) 912 goto bad; 913 } 914 #endif /* FAST_IPSEC */ 915 916 /* 917 * We must forward the packet to the correct protocol thread if 918 * we are not already in it. 919 * 920 * NOTE: ip_len is now in host form. ip_len is not adjusted 921 * further for protocol processing, instead we pass hlen 922 * to the protosw and let it deal with it. 923 */ 924 ipstat.ips_delivered++; 925 926 if ((m->m_flags & M_HASH) == 0) { 927 #ifdef RSS_DEBUG 928 atomic_add_long(&ip_rehash_count, 1); 929 #endif 930 ip->ip_len = htons(ip->ip_len + hlen); 931 ip->ip_off = htons(ip->ip_off); 932 933 ip_hashfn(&m, 0, IP_MPORT_IN); 934 if (m == NULL) 935 return; 936 937 ip = mtod(m, struct ip *); 938 ip->ip_len = ntohs(ip->ip_len) - hlen; 939 ip->ip_off = ntohs(ip->ip_off); 940 KKASSERT(m->m_flags & M_HASH); 941 } 942 port = netisr_hashport(m->m_pkthdr.hash); 943 944 if (port != &curthread->td_msgport) { 945 struct netmsg_packet *pmsg; 946 947 #ifdef RSS_DEBUG 948 atomic_add_long(&ip_dispatch_slow, 1); 949 #endif 950 951 pmsg = &m->m_hdr.mh_netmsg; 952 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 953 0, transport_processing_handler); 954 pmsg->nm_packet = m; 955 pmsg->base.lmsg.u.ms_result = hlen; 956 lwkt_sendmsg(port, &pmsg->base.lmsg); 957 } else { 958 #ifdef RSS_DEBUG 959 atomic_add_long(&ip_dispatch_fast, 1); 960 #endif 961 transport_processing_oncpu(m, hlen, ip); 962 } 963 return; 964 965 bad: 966 m_freem(m); 967 } 968 969 /* 970 * Take incoming datagram fragment and try to reassemble it into 971 * whole datagram. If a chain for reassembly of this datagram already 972 * exists, then it is given as fp; otherwise have to make a chain. 973 */ 974 struct mbuf * 975 ip_reass(struct mbuf *m) 976 { 977 struct ip *ip = mtod(m, struct ip *); 978 struct mbuf *p = NULL, *q, *nq; 979 struct mbuf *n; 980 struct ipq *fp = NULL; 981 struct ipqhead *head; 982 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 983 int i, next; 984 u_short sum; 985 986 /* If maxnipq is 0, never accept fragments. */ 987 if (maxnipq == 0) { 988 ipstat.ips_fragments++; 989 ipstat.ips_fragdropped++; 990 m_freem(m); 991 return NULL; 992 } 993 994 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); 995 /* 996 * Look for queue of fragments of this datagram. 997 */ 998 lwkt_gettoken(&ipq_token); 999 head = &ipq[sum]; 1000 TAILQ_FOREACH(fp, head, ipq_list) { 1001 if (ip->ip_id == fp->ipq_id && 1002 ip->ip_src.s_addr == fp->ipq_src.s_addr && 1003 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 1004 ip->ip_p == fp->ipq_p) 1005 goto found; 1006 } 1007 1008 fp = NULL; 1009 1010 /* 1011 * Enforce upper bound on number of fragmented packets 1012 * for which we attempt reassembly; 1013 * If maxnipq is -1, accept all fragments without limitation. 1014 */ 1015 if (nipq > maxnipq && maxnipq > 0) { 1016 /* 1017 * drop something from the tail of the current queue 1018 * before proceeding further 1019 */ 1020 struct ipq *q = TAILQ_LAST(head, ipqhead); 1021 if (q == NULL) { 1022 /* 1023 * The current queue is empty, 1024 * so drop from one of the others. 1025 */ 1026 for (i = 0; i < IPREASS_NHASH; i++) { 1027 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead); 1028 if (r) { 1029 ipstat.ips_fragtimeout += r->ipq_nfrags; 1030 ip_freef(&ipq[i], r); 1031 break; 1032 } 1033 } 1034 } else { 1035 ipstat.ips_fragtimeout += q->ipq_nfrags; 1036 ip_freef(head, q); 1037 } 1038 } 1039 found: 1040 /* 1041 * Adjust ip_len to not reflect header, 1042 * convert offset of this to bytes. 1043 */ 1044 ip->ip_len -= hlen; 1045 if (ip->ip_off & IP_MF) { 1046 /* 1047 * Make sure that fragments have a data length 1048 * that's a non-zero multiple of 8 bytes. 1049 */ 1050 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 1051 ipstat.ips_toosmall++; /* XXX */ 1052 m_freem(m); 1053 goto done; 1054 } 1055 m->m_flags |= M_FRAG; 1056 } else { 1057 m->m_flags &= ~M_FRAG; 1058 } 1059 ip->ip_off <<= 3; 1060 1061 ipstat.ips_fragments++; 1062 m->m_pkthdr.header = ip; 1063 1064 /* 1065 * If the hardware has not done csum over this fragment 1066 * then csum_data is not valid at all. 1067 */ 1068 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) 1069 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) { 1070 m->m_pkthdr.csum_data = 0; 1071 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 1072 } 1073 1074 /* 1075 * Presence of header sizes in mbufs 1076 * would confuse code below. 1077 */ 1078 m->m_data += hlen; 1079 m->m_len -= hlen; 1080 1081 /* 1082 * If first fragment to arrive, create a reassembly queue. 1083 */ 1084 if (fp == NULL) { 1085 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL) 1086 goto dropfrag; 1087 TAILQ_INSERT_HEAD(head, fp, ipq_list); 1088 nipq++; 1089 fp->ipq_nfrags = 1; 1090 fp->ipq_ttl = IPFRAGTTL; 1091 fp->ipq_p = ip->ip_p; 1092 fp->ipq_id = ip->ip_id; 1093 fp->ipq_src = ip->ip_src; 1094 fp->ipq_dst = ip->ip_dst; 1095 fp->ipq_frags = m; 1096 m->m_nextpkt = NULL; 1097 goto inserted; 1098 } else { 1099 fp->ipq_nfrags++; 1100 } 1101 1102 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header)) 1103 1104 /* 1105 * Find a segment which begins after this one does. 1106 */ 1107 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1108 if (GETIP(q)->ip_off > ip->ip_off) 1109 break; 1110 } 1111 1112 /* 1113 * If there is a preceding segment, it may provide some of 1114 * our data already. If so, drop the data from the incoming 1115 * segment. If it provides all of our data, drop us, otherwise 1116 * stick new segment in the proper place. 1117 * 1118 * If some of the data is dropped from the the preceding 1119 * segment, then it's checksum is invalidated. 1120 */ 1121 if (p) { 1122 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off; 1123 if (i > 0) { 1124 if (i >= ip->ip_len) 1125 goto dropfrag; 1126 m_adj(m, i); 1127 m->m_pkthdr.csum_flags = 0; 1128 ip->ip_off += i; 1129 ip->ip_len -= i; 1130 } 1131 m->m_nextpkt = p->m_nextpkt; 1132 p->m_nextpkt = m; 1133 } else { 1134 m->m_nextpkt = fp->ipq_frags; 1135 fp->ipq_frags = m; 1136 } 1137 1138 /* 1139 * While we overlap succeeding segments trim them or, 1140 * if they are completely covered, dequeue them. 1141 */ 1142 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off; 1143 q = nq) { 1144 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off; 1145 if (i < GETIP(q)->ip_len) { 1146 GETIP(q)->ip_len -= i; 1147 GETIP(q)->ip_off += i; 1148 m_adj(q, i); 1149 q->m_pkthdr.csum_flags = 0; 1150 break; 1151 } 1152 nq = q->m_nextpkt; 1153 m->m_nextpkt = nq; 1154 ipstat.ips_fragdropped++; 1155 fp->ipq_nfrags--; 1156 q->m_nextpkt = NULL; 1157 m_freem(q); 1158 } 1159 1160 inserted: 1161 /* 1162 * Check for complete reassembly and perform frag per packet 1163 * limiting. 1164 * 1165 * Frag limiting is performed here so that the nth frag has 1166 * a chance to complete the packet before we drop the packet. 1167 * As a result, n+1 frags are actually allowed per packet, but 1168 * only n will ever be stored. (n = maxfragsperpacket.) 1169 * 1170 */ 1171 next = 0; 1172 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1173 if (GETIP(q)->ip_off != next) { 1174 if (fp->ipq_nfrags > maxfragsperpacket) { 1175 ipstat.ips_fragdropped += fp->ipq_nfrags; 1176 ip_freef(head, fp); 1177 } 1178 goto done; 1179 } 1180 next += GETIP(q)->ip_len; 1181 } 1182 /* Make sure the last packet didn't have the IP_MF flag */ 1183 if (p->m_flags & M_FRAG) { 1184 if (fp->ipq_nfrags > maxfragsperpacket) { 1185 ipstat.ips_fragdropped += fp->ipq_nfrags; 1186 ip_freef(head, fp); 1187 } 1188 goto done; 1189 } 1190 1191 /* 1192 * Reassembly is complete. Make sure the packet is a sane size. 1193 */ 1194 q = fp->ipq_frags; 1195 ip = GETIP(q); 1196 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) { 1197 ipstat.ips_toolong++; 1198 ipstat.ips_fragdropped += fp->ipq_nfrags; 1199 ip_freef(head, fp); 1200 goto done; 1201 } 1202 1203 /* 1204 * Concatenate fragments. 1205 */ 1206 m = q; 1207 n = m->m_next; 1208 m->m_next = NULL; 1209 m_cat(m, n); 1210 nq = q->m_nextpkt; 1211 q->m_nextpkt = NULL; 1212 for (q = nq; q != NULL; q = nq) { 1213 nq = q->m_nextpkt; 1214 q->m_nextpkt = NULL; 1215 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 1216 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 1217 m_cat(m, q); 1218 } 1219 1220 /* 1221 * Clean up the 1's complement checksum. Carry over 16 bits must 1222 * be added back. This assumes no more then 65535 packet fragments 1223 * were reassembled. A second carry can also occur (but not a third). 1224 */ 1225 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + 1226 (m->m_pkthdr.csum_data >> 16); 1227 if (m->m_pkthdr.csum_data > 0xFFFF) 1228 m->m_pkthdr.csum_data -= 0xFFFF; 1229 1230 /* 1231 * Create header for new ip packet by 1232 * modifying header of first packet; 1233 * dequeue and discard fragment reassembly header. 1234 * Make header visible. 1235 */ 1236 ip->ip_len = next; 1237 ip->ip_src = fp->ipq_src; 1238 ip->ip_dst = fp->ipq_dst; 1239 TAILQ_REMOVE(head, fp, ipq_list); 1240 nipq--; 1241 mpipe_free(&ipq_mpipe, fp); 1242 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2); 1243 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2); 1244 /* some debugging cruft by sklower, below, will go away soon */ 1245 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 1246 int plen = 0; 1247 1248 for (n = m; n; n = n->m_next) 1249 plen += n->m_len; 1250 m->m_pkthdr.len = plen; 1251 } 1252 1253 /* 1254 * Reassembly complete, return the next protocol. 1255 * 1256 * Be sure to clear M_HASH to force the packet 1257 * to be re-characterized. 1258 * 1259 * Clear M_FRAG, we are no longer a fragment. 1260 */ 1261 m->m_flags &= ~(M_HASH | M_FRAG); 1262 1263 ipstat.ips_reassembled++; 1264 lwkt_reltoken(&ipq_token); 1265 return (m); 1266 1267 dropfrag: 1268 ipstat.ips_fragdropped++; 1269 if (fp != NULL) 1270 fp->ipq_nfrags--; 1271 m_freem(m); 1272 done: 1273 lwkt_reltoken(&ipq_token); 1274 return (NULL); 1275 1276 #undef GETIP 1277 } 1278 1279 /* 1280 * Free a fragment reassembly header and all 1281 * associated datagrams. 1282 * 1283 * Called with ipq_token held. 1284 */ 1285 static void 1286 ip_freef(struct ipqhead *fhp, struct ipq *fp) 1287 { 1288 struct mbuf *q; 1289 1290 /* 1291 * Remove first to protect against blocking 1292 */ 1293 TAILQ_REMOVE(fhp, fp, ipq_list); 1294 1295 /* 1296 * Clean out at our leisure 1297 */ 1298 while (fp->ipq_frags) { 1299 q = fp->ipq_frags; 1300 fp->ipq_frags = q->m_nextpkt; 1301 q->m_nextpkt = NULL; 1302 m_freem(q); 1303 } 1304 mpipe_free(&ipq_mpipe, fp); 1305 nipq--; 1306 } 1307 1308 /* 1309 * IP timer processing; 1310 * if a timer expires on a reassembly 1311 * queue, discard it. 1312 */ 1313 void 1314 ip_slowtimo(void) 1315 { 1316 struct ipq *fp, *fp_temp; 1317 struct ipqhead *head; 1318 int i; 1319 1320 lwkt_gettoken(&ipq_token); 1321 for (i = 0; i < IPREASS_NHASH; i++) { 1322 head = &ipq[i]; 1323 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) { 1324 if (--fp->ipq_ttl == 0) { 1325 ipstat.ips_fragtimeout += fp->ipq_nfrags; 1326 ip_freef(head, fp); 1327 } 1328 } 1329 } 1330 /* 1331 * If we are over the maximum number of fragments 1332 * (due to the limit being lowered), drain off 1333 * enough to get down to the new limit. 1334 */ 1335 if (maxnipq >= 0 && nipq > maxnipq) { 1336 for (i = 0; i < IPREASS_NHASH; i++) { 1337 head = &ipq[i]; 1338 while (nipq > maxnipq && !TAILQ_EMPTY(head)) { 1339 ipstat.ips_fragdropped += 1340 TAILQ_FIRST(head)->ipq_nfrags; 1341 ip_freef(head, TAILQ_FIRST(head)); 1342 } 1343 } 1344 } 1345 lwkt_reltoken(&ipq_token); 1346 ipflow_slowtimo(); 1347 } 1348 1349 /* 1350 * Drain off all datagram fragments. 1351 */ 1352 void 1353 ip_drain(void) 1354 { 1355 struct ipqhead *head; 1356 int i; 1357 1358 lwkt_gettoken(&ipq_token); 1359 for (i = 0; i < IPREASS_NHASH; i++) { 1360 head = &ipq[i]; 1361 while (!TAILQ_EMPTY(head)) { 1362 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags; 1363 ip_freef(head, TAILQ_FIRST(head)); 1364 } 1365 } 1366 lwkt_reltoken(&ipq_token); 1367 in_rtqdrain(); 1368 } 1369 1370 /* 1371 * Do option processing on a datagram, 1372 * possibly discarding it if bad options are encountered, 1373 * or forwarding it if source-routed. 1374 * The pass argument is used when operating in the IPSTEALTH 1375 * mode to tell what options to process: 1376 * [LS]SRR (pass 0) or the others (pass 1). 1377 * The reason for as many as two passes is that when doing IPSTEALTH, 1378 * non-routing options should be processed only if the packet is for us. 1379 * Returns 1 if packet has been forwarded/freed, 1380 * 0 if the packet should be processed further. 1381 */ 1382 static int 1383 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop) 1384 { 1385 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET }; 1386 struct ip *ip = mtod(m, struct ip *); 1387 u_char *cp; 1388 struct in_ifaddr *ia; 1389 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB; 1390 boolean_t forward = FALSE; 1391 struct in_addr *sin, dst; 1392 n_time ntime; 1393 1394 dst = ip->ip_dst; 1395 cp = (u_char *)(ip + 1); 1396 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1397 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1398 opt = cp[IPOPT_OPTVAL]; 1399 if (opt == IPOPT_EOL) 1400 break; 1401 if (opt == IPOPT_NOP) 1402 optlen = 1; 1403 else { 1404 if (cnt < IPOPT_OLEN + sizeof(*cp)) { 1405 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1406 goto bad; 1407 } 1408 optlen = cp[IPOPT_OLEN]; 1409 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 1410 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1411 goto bad; 1412 } 1413 } 1414 switch (opt) { 1415 1416 default: 1417 break; 1418 1419 /* 1420 * Source routing with record. 1421 * Find interface with current destination address. 1422 * If none on this machine then drop if strictly routed, 1423 * or do nothing if loosely routed. 1424 * Record interface address and bring up next address 1425 * component. If strictly routed make sure next 1426 * address is on directly accessible net. 1427 */ 1428 case IPOPT_LSRR: 1429 case IPOPT_SSRR: 1430 if (ipstealth && pass > 0) 1431 break; 1432 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1433 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1434 goto bad; 1435 } 1436 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1437 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1438 goto bad; 1439 } 1440 ipaddr.sin_addr = ip->ip_dst; 1441 ia = (struct in_ifaddr *) 1442 ifa_ifwithaddr((struct sockaddr *)&ipaddr); 1443 if (ia == NULL) { 1444 if (opt == IPOPT_SSRR) { 1445 type = ICMP_UNREACH; 1446 code = ICMP_UNREACH_SRCFAIL; 1447 goto bad; 1448 } 1449 if (!ip_dosourceroute) 1450 goto nosourcerouting; 1451 /* 1452 * Loose routing, and not at next destination 1453 * yet; nothing to do except forward. 1454 */ 1455 break; 1456 } 1457 off--; /* 0 origin */ 1458 if (off > optlen - (int)sizeof(struct in_addr)) { 1459 /* 1460 * End of source route. Should be for us. 1461 */ 1462 if (!ip_acceptsourceroute) 1463 goto nosourcerouting; 1464 save_rte(m, cp, ip->ip_src); 1465 break; 1466 } 1467 if (ipstealth) 1468 goto dropit; 1469 if (!ip_dosourceroute) { 1470 if (ipforwarding) { 1471 char buf[sizeof "aaa.bbb.ccc.ddd"]; 1472 1473 /* 1474 * Acting as a router, so generate ICMP 1475 */ 1476 nosourcerouting: 1477 strcpy(buf, inet_ntoa(ip->ip_dst)); 1478 log(LOG_WARNING, 1479 "attempted source route from %s to %s\n", 1480 inet_ntoa(ip->ip_src), buf); 1481 type = ICMP_UNREACH; 1482 code = ICMP_UNREACH_SRCFAIL; 1483 goto bad; 1484 } else { 1485 /* 1486 * Not acting as a router, 1487 * so silently drop. 1488 */ 1489 dropit: 1490 ipstat.ips_cantforward++; 1491 m_freem(m); 1492 return (1); 1493 } 1494 } 1495 1496 /* 1497 * locate outgoing interface 1498 */ 1499 memcpy(&ipaddr.sin_addr, cp + off, 1500 sizeof ipaddr.sin_addr); 1501 1502 if (opt == IPOPT_SSRR) { 1503 #define INA struct in_ifaddr * 1504 #define SA struct sockaddr * 1505 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) 1506 == NULL) 1507 ia = (INA)ifa_ifwithnet((SA)&ipaddr); 1508 } else { 1509 ia = ip_rtaddr(ipaddr.sin_addr, NULL); 1510 } 1511 if (ia == NULL) { 1512 type = ICMP_UNREACH; 1513 code = ICMP_UNREACH_SRCFAIL; 1514 goto bad; 1515 } 1516 ip->ip_dst = ipaddr.sin_addr; 1517 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1518 sizeof(struct in_addr)); 1519 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1520 /* 1521 * Let ip_intr's mcast routing check handle mcast pkts 1522 */ 1523 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); 1524 break; 1525 1526 case IPOPT_RR: 1527 if (ipstealth && pass == 0) 1528 break; 1529 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1530 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1531 goto bad; 1532 } 1533 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1534 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1535 goto bad; 1536 } 1537 /* 1538 * If no space remains, ignore. 1539 */ 1540 off--; /* 0 origin */ 1541 if (off > optlen - (int)sizeof(struct in_addr)) 1542 break; 1543 memcpy(&ipaddr.sin_addr, &ip->ip_dst, 1544 sizeof ipaddr.sin_addr); 1545 /* 1546 * locate outgoing interface; if we're the destination, 1547 * use the incoming interface (should be same). 1548 */ 1549 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL && 1550 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) { 1551 type = ICMP_UNREACH; 1552 code = ICMP_UNREACH_HOST; 1553 goto bad; 1554 } 1555 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1556 sizeof(struct in_addr)); 1557 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1558 break; 1559 1560 case IPOPT_TS: 1561 if (ipstealth && pass == 0) 1562 break; 1563 code = cp - (u_char *)ip; 1564 if (optlen < 4 || optlen > 40) { 1565 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1566 goto bad; 1567 } 1568 if ((off = cp[IPOPT_OFFSET]) < 5) { 1569 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1570 goto bad; 1571 } 1572 if (off > optlen - (int)sizeof(int32_t)) { 1573 cp[IPOPT_OFFSET + 1] += (1 << 4); 1574 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) { 1575 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1576 goto bad; 1577 } 1578 break; 1579 } 1580 off--; /* 0 origin */ 1581 sin = (struct in_addr *)(cp + off); 1582 switch (cp[IPOPT_OFFSET + 1] & 0x0f) { 1583 1584 case IPOPT_TS_TSONLY: 1585 break; 1586 1587 case IPOPT_TS_TSANDADDR: 1588 if (off + sizeof(n_time) + 1589 sizeof(struct in_addr) > optlen) { 1590 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1591 goto bad; 1592 } 1593 ipaddr.sin_addr = dst; 1594 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1595 m->m_pkthdr.rcvif); 1596 if (ia == NULL) 1597 continue; 1598 memcpy(sin, &IA_SIN(ia)->sin_addr, 1599 sizeof(struct in_addr)); 1600 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1601 off += sizeof(struct in_addr); 1602 break; 1603 1604 case IPOPT_TS_PRESPEC: 1605 if (off + sizeof(n_time) + 1606 sizeof(struct in_addr) > optlen) { 1607 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1608 goto bad; 1609 } 1610 memcpy(&ipaddr.sin_addr, sin, 1611 sizeof(struct in_addr)); 1612 if (ifa_ifwithaddr((SA)&ipaddr) == NULL) 1613 continue; 1614 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1615 off += sizeof(struct in_addr); 1616 break; 1617 1618 default: 1619 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip; 1620 goto bad; 1621 } 1622 ntime = iptime(); 1623 memcpy(cp + off, &ntime, sizeof(n_time)); 1624 cp[IPOPT_OFFSET] += sizeof(n_time); 1625 } 1626 } 1627 if (forward && ipforwarding) { 1628 ip_forward(m, TRUE, next_hop); 1629 return (1); 1630 } 1631 return (0); 1632 bad: 1633 icmp_error(m, type, code, 0, 0); 1634 ipstat.ips_badoptions++; 1635 return (1); 1636 } 1637 1638 /* 1639 * Given address of next destination (final or next hop), 1640 * return internet address info of interface to be used to get there. 1641 */ 1642 struct in_ifaddr * 1643 ip_rtaddr(struct in_addr dst, struct route *ro0) 1644 { 1645 struct route sro, *ro; 1646 struct sockaddr_in *sin; 1647 struct in_ifaddr *ia; 1648 1649 if (ro0 != NULL) { 1650 ro = ro0; 1651 } else { 1652 bzero(&sro, sizeof(sro)); 1653 ro = &sro; 1654 } 1655 1656 sin = (struct sockaddr_in *)&ro->ro_dst; 1657 1658 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) { 1659 if (ro->ro_rt != NULL) { 1660 RTFREE(ro->ro_rt); 1661 ro->ro_rt = NULL; 1662 } 1663 sin->sin_family = AF_INET; 1664 sin->sin_len = sizeof *sin; 1665 sin->sin_addr = dst; 1666 rtalloc_ign(ro, RTF_PRCLONING); 1667 } 1668 1669 if (ro->ro_rt == NULL) 1670 return (NULL); 1671 1672 ia = ifatoia(ro->ro_rt->rt_ifa); 1673 1674 if (ro == &sro) 1675 RTFREE(ro->ro_rt); 1676 return ia; 1677 } 1678 1679 /* 1680 * Save incoming source route for use in replies, 1681 * to be picked up later by ip_srcroute if the receiver is interested. 1682 */ 1683 static void 1684 save_rte(struct mbuf *m, u_char *option, struct in_addr dst) 1685 { 1686 struct m_tag *mtag; 1687 struct ip_srcrt_opt *opt; 1688 unsigned olen; 1689 1690 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT); 1691 if (mtag == NULL) 1692 return; 1693 opt = m_tag_data(mtag); 1694 1695 olen = option[IPOPT_OLEN]; 1696 #ifdef DIAGNOSTIC 1697 if (ipprintfs) 1698 kprintf("save_rte: olen %d\n", olen); 1699 #endif 1700 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) { 1701 m_tag_free(mtag); 1702 return; 1703 } 1704 bcopy(option, opt->ip_srcrt.srcopt, olen); 1705 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1706 opt->ip_srcrt.dst = dst; 1707 m_tag_prepend(m, mtag); 1708 } 1709 1710 /* 1711 * Retrieve incoming source route for use in replies, 1712 * in the same form used by setsockopt. 1713 * The first hop is placed before the options, will be removed later. 1714 */ 1715 struct mbuf * 1716 ip_srcroute(struct mbuf *m0) 1717 { 1718 struct in_addr *p, *q; 1719 struct mbuf *m; 1720 struct m_tag *mtag; 1721 struct ip_srcrt_opt *opt; 1722 1723 if (m0 == NULL) 1724 return NULL; 1725 1726 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL); 1727 if (mtag == NULL) 1728 return NULL; 1729 opt = m_tag_data(mtag); 1730 1731 if (opt->ip_nhops == 0) 1732 return (NULL); 1733 m = m_get(MB_DONTWAIT, MT_HEADER); 1734 if (m == NULL) 1735 return (NULL); 1736 1737 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt)) 1738 1739 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1740 m->m_len = opt->ip_nhops * sizeof(struct in_addr) + 1741 sizeof(struct in_addr) + OPTSIZ; 1742 #ifdef DIAGNOSTIC 1743 if (ipprintfs) { 1744 kprintf("ip_srcroute: nhops %d mlen %d", 1745 opt->ip_nhops, m->m_len); 1746 } 1747 #endif 1748 1749 /* 1750 * First save first hop for return route 1751 */ 1752 p = &opt->ip_srcrt.route[opt->ip_nhops - 1]; 1753 *(mtod(m, struct in_addr *)) = *p--; 1754 #ifdef DIAGNOSTIC 1755 if (ipprintfs) 1756 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1757 #endif 1758 1759 /* 1760 * Copy option fields and padding (nop) to mbuf. 1761 */ 1762 opt->ip_srcrt.nop = IPOPT_NOP; 1763 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1764 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop, 1765 OPTSIZ); 1766 q = (struct in_addr *)(mtod(m, caddr_t) + 1767 sizeof(struct in_addr) + OPTSIZ); 1768 #undef OPTSIZ 1769 /* 1770 * Record return path as an IP source route, 1771 * reversing the path (pointers are now aligned). 1772 */ 1773 while (p >= opt->ip_srcrt.route) { 1774 #ifdef DIAGNOSTIC 1775 if (ipprintfs) 1776 kprintf(" %x", ntohl(q->s_addr)); 1777 #endif 1778 *q++ = *p--; 1779 } 1780 /* 1781 * Last hop goes to final destination. 1782 */ 1783 *q = opt->ip_srcrt.dst; 1784 m_tag_delete(m0, mtag); 1785 #ifdef DIAGNOSTIC 1786 if (ipprintfs) 1787 kprintf(" %x\n", ntohl(q->s_addr)); 1788 #endif 1789 return (m); 1790 } 1791 1792 /* 1793 * Strip out IP options. 1794 */ 1795 void 1796 ip_stripoptions(struct mbuf *m) 1797 { 1798 int datalen; 1799 struct ip *ip = mtod(m, struct ip *); 1800 caddr_t opts; 1801 int optlen; 1802 1803 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1804 opts = (caddr_t)(ip + 1); 1805 datalen = m->m_len - (sizeof(struct ip) + optlen); 1806 bcopy(opts + optlen, opts, datalen); 1807 m->m_len -= optlen; 1808 if (m->m_flags & M_PKTHDR) 1809 m->m_pkthdr.len -= optlen; 1810 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2); 1811 } 1812 1813 u_char inetctlerrmap[PRC_NCMDS] = { 1814 0, 0, 0, 0, 1815 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1816 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1817 EMSGSIZE, EHOSTUNREACH, 0, 0, 1818 0, 0, 0, 0, 1819 ENOPROTOOPT, ECONNREFUSED 1820 }; 1821 1822 /* 1823 * Forward a packet. If some error occurs return the sender 1824 * an icmp packet. Note we can't always generate a meaningful 1825 * icmp message because icmp doesn't have a large enough repertoire 1826 * of codes and types. 1827 * 1828 * If not forwarding, just drop the packet. This could be confusing 1829 * if ipforwarding was zero but some routing protocol was advancing 1830 * us as a gateway to somewhere. However, we must let the routing 1831 * protocol deal with that. 1832 * 1833 * The using_srcrt parameter indicates whether the packet is being forwarded 1834 * via a source route. 1835 */ 1836 void 1837 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop) 1838 { 1839 struct ip *ip = mtod(m, struct ip *); 1840 struct rtentry *rt; 1841 struct route fwd_ro; 1842 int error, type = 0, code = 0, destmtu = 0; 1843 struct mbuf *mcopy, *mtemp = NULL; 1844 n_long dest; 1845 struct in_addr pkt_dst; 1846 1847 dest = INADDR_ANY; 1848 /* 1849 * Cache the destination address of the packet; this may be 1850 * changed by use of 'ipfw fwd'. 1851 */ 1852 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst; 1853 1854 #ifdef DIAGNOSTIC 1855 if (ipprintfs) 1856 kprintf("forward: src %x dst %x ttl %x\n", 1857 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl); 1858 #endif 1859 1860 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) { 1861 ipstat.ips_cantforward++; 1862 m_freem(m); 1863 return; 1864 } 1865 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) { 1866 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1867 return; 1868 } 1869 1870 bzero(&fwd_ro, sizeof(fwd_ro)); 1871 ip_rtaddr(pkt_dst, &fwd_ro); 1872 if (fwd_ro.ro_rt == NULL) { 1873 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1874 return; 1875 } 1876 rt = fwd_ro.ro_rt; 1877 1878 if (curthread->td_type == TD_TYPE_NETISR) { 1879 /* 1880 * Save the IP header and at most 8 bytes of the payload, 1881 * in case we need to generate an ICMP message to the src. 1882 */ 1883 mtemp = ipforward_mtemp[mycpuid]; 1884 KASSERT((mtemp->m_flags & M_EXT) == 0 && 1885 mtemp->m_data == mtemp->m_pktdat && 1886 m_tag_first(mtemp) == NULL, 1887 ("ip_forward invalid mtemp1")); 1888 1889 if (!m_dup_pkthdr(mtemp, m, MB_DONTWAIT)) { 1890 /* 1891 * It's probably ok if the pkthdr dup fails (because 1892 * the deep copy of the tag chain failed), but for now 1893 * be conservative and just discard the copy since 1894 * code below may some day want the tags. 1895 */ 1896 mtemp = NULL; 1897 } else { 1898 mtemp->m_type = m->m_type; 1899 mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8, 1900 (int)ip->ip_len); 1901 mtemp->m_pkthdr.len = mtemp->m_len; 1902 m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t)); 1903 } 1904 } 1905 1906 if (!ipstealth) 1907 ip->ip_ttl -= IPTTLDEC; 1908 1909 /* 1910 * If forwarding packet using same interface that it came in on, 1911 * perhaps should send a redirect to sender to shortcut a hop. 1912 * Only send redirect if source is sending directly to us, 1913 * and if packet was not source routed (or has any options). 1914 * Also, don't send redirect if forwarding using a default route 1915 * or a route modified by a redirect. 1916 */ 1917 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1918 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) && 1919 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY && 1920 ipsendredirects && !using_srcrt && next_hop == NULL) { 1921 u_long src = ntohl(ip->ip_src.s_addr); 1922 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa; 1923 1924 if (rt_ifa != NULL && 1925 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) { 1926 if (rt->rt_flags & RTF_GATEWAY) 1927 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1928 else 1929 dest = pkt_dst.s_addr; 1930 /* 1931 * Router requirements says to only send 1932 * host redirects. 1933 */ 1934 type = ICMP_REDIRECT; 1935 code = ICMP_REDIRECT_HOST; 1936 #ifdef DIAGNOSTIC 1937 if (ipprintfs) 1938 kprintf("redirect (%d) to %x\n", code, dest); 1939 #endif 1940 } 1941 } 1942 1943 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL); 1944 if (error == 0) { 1945 ipstat.ips_forward++; 1946 if (type == 0) { 1947 if (mtemp) 1948 ipflow_create(&fwd_ro, mtemp); 1949 goto done; 1950 } else { 1951 ipstat.ips_redirectsent++; 1952 } 1953 } else { 1954 ipstat.ips_cantforward++; 1955 } 1956 1957 if (mtemp == NULL) 1958 goto done; 1959 1960 /* 1961 * Errors that do not require generating ICMP message 1962 */ 1963 switch (error) { 1964 case ENOBUFS: 1965 /* 1966 * A router should not generate ICMP_SOURCEQUENCH as 1967 * required in RFC1812 Requirements for IP Version 4 Routers. 1968 * Source quench could be a big problem under DoS attacks, 1969 * or if the underlying interface is rate-limited. 1970 * Those who need source quench packets may re-enable them 1971 * via the net.inet.ip.sendsourcequench sysctl. 1972 */ 1973 if (!ip_sendsourcequench) 1974 goto done; 1975 break; 1976 1977 case EACCES: /* ipfw denied packet */ 1978 goto done; 1979 } 1980 1981 KASSERT((mtemp->m_flags & M_EXT) == 0 && 1982 mtemp->m_data == mtemp->m_pktdat, 1983 ("ip_forward invalid mtemp2")); 1984 mcopy = m_copym(mtemp, 0, mtemp->m_len, MB_DONTWAIT); 1985 if (mcopy == NULL) 1986 goto done; 1987 1988 /* 1989 * Send ICMP message. 1990 */ 1991 switch (error) { 1992 case 0: /* forwarded, but need redirect */ 1993 /* type, code set above */ 1994 break; 1995 1996 case ENETUNREACH: /* shouldn't happen, checked above */ 1997 case EHOSTUNREACH: 1998 case ENETDOWN: 1999 case EHOSTDOWN: 2000 default: 2001 type = ICMP_UNREACH; 2002 code = ICMP_UNREACH_HOST; 2003 break; 2004 2005 case EMSGSIZE: 2006 type = ICMP_UNREACH; 2007 code = ICMP_UNREACH_NEEDFRAG; 2008 #ifdef IPSEC 2009 /* 2010 * If the packet is routed over IPsec tunnel, tell the 2011 * originator the tunnel MTU. 2012 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 2013 * XXX quickhack!!! 2014 */ 2015 if (fwd_ro.ro_rt != NULL) { 2016 struct secpolicy *sp = NULL; 2017 int ipsecerror; 2018 int ipsechdr; 2019 struct route *ro; 2020 2021 sp = ipsec4_getpolicybyaddr(mcopy, 2022 IPSEC_DIR_OUTBOUND, 2023 IP_FORWARDING, 2024 &ipsecerror); 2025 2026 if (sp == NULL) 2027 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2028 else { 2029 /* count IPsec header size */ 2030 ipsechdr = ipsec4_hdrsiz(mcopy, 2031 IPSEC_DIR_OUTBOUND, 2032 NULL); 2033 2034 /* 2035 * find the correct route for outer IPv4 2036 * header, compute tunnel MTU. 2037 * 2038 */ 2039 if (sp->req != NULL && sp->req->sav != NULL && 2040 sp->req->sav->sah != NULL) { 2041 ro = &sp->req->sav->sah->sa_route; 2042 if (ro->ro_rt != NULL && 2043 ro->ro_rt->rt_ifp != NULL) { 2044 destmtu = 2045 ro->ro_rt->rt_ifp->if_mtu; 2046 destmtu -= ipsechdr; 2047 } 2048 } 2049 2050 key_freesp(sp); 2051 } 2052 } 2053 #elif FAST_IPSEC 2054 /* 2055 * If the packet is routed over IPsec tunnel, tell the 2056 * originator the tunnel MTU. 2057 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 2058 * XXX quickhack!!! 2059 */ 2060 if (fwd_ro.ro_rt != NULL) { 2061 struct secpolicy *sp = NULL; 2062 int ipsecerror; 2063 int ipsechdr; 2064 struct route *ro; 2065 2066 sp = ipsec_getpolicybyaddr(mcopy, 2067 IPSEC_DIR_OUTBOUND, 2068 IP_FORWARDING, 2069 &ipsecerror); 2070 2071 if (sp == NULL) 2072 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2073 else { 2074 /* count IPsec header size */ 2075 ipsechdr = ipsec4_hdrsiz(mcopy, 2076 IPSEC_DIR_OUTBOUND, 2077 NULL); 2078 2079 /* 2080 * find the correct route for outer IPv4 2081 * header, compute tunnel MTU. 2082 */ 2083 2084 if (sp->req != NULL && 2085 sp->req->sav != NULL && 2086 sp->req->sav->sah != NULL) { 2087 ro = &sp->req->sav->sah->sa_route; 2088 if (ro->ro_rt != NULL && 2089 ro->ro_rt->rt_ifp != NULL) { 2090 destmtu = 2091 ro->ro_rt->rt_ifp->if_mtu; 2092 destmtu -= ipsechdr; 2093 } 2094 } 2095 2096 KEY_FREESP(&sp); 2097 } 2098 } 2099 #else /* !IPSEC && !FAST_IPSEC */ 2100 if (fwd_ro.ro_rt != NULL) 2101 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2102 #endif /*IPSEC*/ 2103 ipstat.ips_cantfrag++; 2104 break; 2105 2106 case ENOBUFS: 2107 type = ICMP_SOURCEQUENCH; 2108 code = 0; 2109 break; 2110 2111 case EACCES: /* ipfw denied packet */ 2112 panic("ip_forward EACCES should not reach"); 2113 } 2114 icmp_error(mcopy, type, code, dest, destmtu); 2115 done: 2116 if (mtemp != NULL) 2117 m_tag_delete_chain(mtemp); 2118 if (fwd_ro.ro_rt != NULL) 2119 RTFREE(fwd_ro.ro_rt); 2120 } 2121 2122 void 2123 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, 2124 struct mbuf *m) 2125 { 2126 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 2127 struct timeval tv; 2128 2129 microtime(&tv); 2130 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 2131 SCM_TIMESTAMP, SOL_SOCKET); 2132 if (*mp) 2133 mp = &(*mp)->m_next; 2134 } 2135 if (inp->inp_flags & INP_RECVDSTADDR) { 2136 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 2137 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 2138 if (*mp) 2139 mp = &(*mp)->m_next; 2140 } 2141 if (inp->inp_flags & INP_RECVTTL) { 2142 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, 2143 sizeof(u_char), IP_RECVTTL, IPPROTO_IP); 2144 if (*mp) 2145 mp = &(*mp)->m_next; 2146 } 2147 #ifdef notyet 2148 /* XXX 2149 * Moving these out of udp_input() made them even more broken 2150 * than they already were. 2151 */ 2152 /* options were tossed already */ 2153 if (inp->inp_flags & INP_RECVOPTS) { 2154 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 2155 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 2156 if (*mp) 2157 mp = &(*mp)->m_next; 2158 } 2159 /* ip_srcroute doesn't do what we want here, need to fix */ 2160 if (inp->inp_flags & INP_RECVRETOPTS) { 2161 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m), 2162 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 2163 if (*mp) 2164 mp = &(*mp)->m_next; 2165 } 2166 #endif 2167 if (inp->inp_flags & INP_RECVIF) { 2168 struct ifnet *ifp; 2169 struct sdlbuf { 2170 struct sockaddr_dl sdl; 2171 u_char pad[32]; 2172 } sdlbuf; 2173 struct sockaddr_dl *sdp; 2174 struct sockaddr_dl *sdl2 = &sdlbuf.sdl; 2175 2176 if (((ifp = m->m_pkthdr.rcvif)) && 2177 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) { 2178 sdp = IF_LLSOCKADDR(ifp); 2179 /* 2180 * Change our mind and don't try copy. 2181 */ 2182 if ((sdp->sdl_family != AF_LINK) || 2183 (sdp->sdl_len > sizeof(sdlbuf))) { 2184 goto makedummy; 2185 } 2186 bcopy(sdp, sdl2, sdp->sdl_len); 2187 } else { 2188 makedummy: 2189 sdl2->sdl_len = 2190 offsetof(struct sockaddr_dl, sdl_data[0]); 2191 sdl2->sdl_family = AF_LINK; 2192 sdl2->sdl_index = 0; 2193 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; 2194 } 2195 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len, 2196 IP_RECVIF, IPPROTO_IP); 2197 if (*mp) 2198 mp = &(*mp)->m_next; 2199 } 2200 } 2201 2202 /* 2203 * XXX these routines are called from the upper part of the kernel. 2204 * 2205 * They could also be moved to ip_mroute.c, since all the RSVP 2206 * handling is done there already. 2207 */ 2208 int 2209 ip_rsvp_init(struct socket *so) 2210 { 2211 if (so->so_type != SOCK_RAW || 2212 so->so_proto->pr_protocol != IPPROTO_RSVP) 2213 return EOPNOTSUPP; 2214 2215 if (ip_rsvpd != NULL) 2216 return EADDRINUSE; 2217 2218 ip_rsvpd = so; 2219 /* 2220 * This may seem silly, but we need to be sure we don't over-increment 2221 * the RSVP counter, in case something slips up. 2222 */ 2223 if (!ip_rsvp_on) { 2224 ip_rsvp_on = 1; 2225 rsvp_on++; 2226 } 2227 2228 return 0; 2229 } 2230 2231 int 2232 ip_rsvp_done(void) 2233 { 2234 ip_rsvpd = NULL; 2235 /* 2236 * This may seem silly, but we need to be sure we don't over-decrement 2237 * the RSVP counter, in case something slips up. 2238 */ 2239 if (ip_rsvp_on) { 2240 ip_rsvp_on = 0; 2241 rsvp_on--; 2242 } 2243 return 0; 2244 } 2245 2246 int 2247 rsvp_input(struct mbuf **mp, int *offp, int proto) 2248 { 2249 struct mbuf *m = *mp; 2250 2251 *mp = NULL; 2252 2253 if (rsvp_input_p) { /* call the real one if loaded */ 2254 *mp = m; 2255 rsvp_input_p(mp, offp, proto); 2256 return(IPPROTO_DONE); 2257 } 2258 2259 /* Can still get packets with rsvp_on = 0 if there is a local member 2260 * of the group to which the RSVP packet is addressed. But in this 2261 * case we want to throw the packet away. 2262 */ 2263 2264 if (!rsvp_on) { 2265 m_freem(m); 2266 return(IPPROTO_DONE); 2267 } 2268 2269 if (ip_rsvpd != NULL) { 2270 *mp = m; 2271 rip_input(mp, offp, proto); 2272 return(IPPROTO_DONE); 2273 } 2274 /* Drop the packet */ 2275 m_freem(m); 2276 return(IPPROTO_DONE); 2277 }
Cache object: 8a4ecc9932d7b87c10e7a1807d76b696
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