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 maxnipq; 164 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW, 165 &maxnipq, 0, 166 "Maximum number of IPv4 fragment reassembly queue entries"); 167 168 static int maxfragsperpacket; 169 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, 170 &maxfragsperpacket, 0, 171 "Maximum number of IPv4 fragments allowed per packet"); 172 173 static int ip_sendsourcequench = 0; 174 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, 175 &ip_sendsourcequench, 0, 176 "Enable the transmission of source quench packets"); 177 178 int ip_do_randomid = 1; 179 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, 180 &ip_do_randomid, 0, 181 "Assign random ip_id values"); 182 /* 183 * XXX - Setting ip_checkinterface mostly implements the receive side of 184 * the Strong ES model described in RFC 1122, but since the routing table 185 * and transmit implementation do not implement the Strong ES model, 186 * setting this to 1 results in an odd hybrid. 187 * 188 * XXX - ip_checkinterface currently must be disabled if you use ipnat 189 * to translate the destination address to another local interface. 190 * 191 * XXX - ip_checkinterface must be disabled if you add IP aliases 192 * to the loopback interface instead of the interface where the 193 * packets for those addresses are received. 194 */ 195 static int ip_checkinterface = 0; 196 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, 197 &ip_checkinterface, 0, "Verify packet arrives on correct interface"); 198 199 static u_long ip_hash_count = 0; 200 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD, 201 &ip_hash_count, 0, "Number of packets hashed by IP"); 202 203 #ifdef RSS_DEBUG 204 static u_long ip_rehash_count = 0; 205 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD, 206 &ip_rehash_count, 0, "Number of packets rehashed by IP"); 207 208 static u_long ip_dispatch_fast = 0; 209 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD, 210 &ip_dispatch_fast, 0, "Number of packets handled on current CPU"); 211 212 static u_long ip_dispatch_slow = 0; 213 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD, 214 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU"); 215 #endif 216 217 #ifdef DIAGNOSTIC 218 static int ipprintfs = 0; 219 #endif 220 221 extern struct domain inetdomain; 222 extern struct protosw inetsw[]; 223 u_char ip_protox[IPPROTO_MAX]; 224 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */ 225 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU]; 226 /* inet addr hash table */ 227 u_long in_ifaddrhmask; /* mask for hash table */ 228 229 static struct mbuf *ipforward_mtemp[MAXCPU]; 230 231 struct ip_stats ipstats_percpu[MAXCPU] __cachealign; 232 233 static int 234 sysctl_ipstats(SYSCTL_HANDLER_ARGS) 235 { 236 int cpu, error = 0; 237 238 for (cpu = 0; cpu < ncpus; ++cpu) { 239 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu], 240 sizeof(struct ip_stats)))) 241 break; 242 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu], 243 sizeof(struct ip_stats)))) 244 break; 245 } 246 247 return (error); 248 } 249 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 250 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics"); 251 252 /* Packet reassembly stuff */ 253 #define IPREASS_NHASH_LOG2 6 254 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) 255 #define IPREASS_HMASK (IPREASS_NHASH - 1) 256 #define IPREASS_HASH(x,y) \ 257 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK) 258 259 TAILQ_HEAD(ipqhead, ipq); 260 struct ipfrag_queue { 261 int nipq; 262 struct netmsg_base timeo_netmsg; 263 struct netmsg_base drain_netmsg; 264 struct ipqhead ipq[IPREASS_NHASH]; 265 } __cachealign; 266 267 static struct ipfrag_queue ipfrag_queue_pcpu[MAXCPU]; 268 269 #ifdef IPCTL_DEFMTU 270 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, 271 &ip_mtu, 0, "Default MTU"); 272 #endif 273 274 #ifdef IPSTEALTH 275 static int ipstealth = 0; 276 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, ""); 277 #else 278 static const int ipstealth = 0; 279 #endif 280 281 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int); 282 283 struct pfil_head inet_pfil_hook; 284 285 /* 286 * struct ip_srcrt_opt is used to store packet state while it travels 287 * through the stack. 288 * 289 * XXX Note that the code even makes assumptions on the size and 290 * alignment of fields inside struct ip_srcrt so e.g. adding some 291 * fields will break the code. This needs to be fixed. 292 * 293 * We need to save the IP options in case a protocol wants to respond 294 * to an incoming packet over the same route if the packet got here 295 * using IP source routing. This allows connection establishment and 296 * maintenance when the remote end is on a network that is not known 297 * to us. 298 */ 299 struct ip_srcrt { 300 struct in_addr dst; /* final destination */ 301 char nop; /* one NOP to align */ 302 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 303 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 304 }; 305 306 struct ip_srcrt_opt { 307 int ip_nhops; 308 struct ip_srcrt ip_srcrt; 309 }; 310 311 #define IPFRAG_MPIPE_MAX 4096 312 #define MAXIPFRAG_MIN ((IPFRAG_MPIPE_MAX * 2) / 256) 313 314 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management"); 315 static struct malloc_pipe ipq_mpipe; 316 317 static void save_rte(struct mbuf *, u_char *, struct in_addr); 318 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *); 319 static void ip_freef(struct ipfrag_queue *, struct ipqhead *, 320 struct ipq *); 321 static void ip_input_handler(netmsg_t); 322 323 static void ipfrag_timeo_dispatch(netmsg_t); 324 static void ipfrag_drain_dispatch(netmsg_t); 325 326 /* 327 * IP initialization: fill in IP protocol switch table. 328 * All protocols not implemented in kernel go to raw IP protocol handler. 329 */ 330 void 331 ip_init(void) 332 { 333 struct protosw *pr; 334 int cpu, i; 335 336 /* 337 * Make sure we can handle a reasonable number of fragments but 338 * cap it at IPFRAG_MPIPE_MAX. 339 */ 340 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq), 341 IFQ_MAXLEN, IPFRAG_MPIPE_MAX, 0, NULL, NULL, NULL); 342 for (cpu = 0; cpu < ncpus; ++cpu) { 343 TAILQ_INIT(&in_ifaddrheads[cpu]); 344 in_ifaddrhashtbls[cpu] = 345 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask); 346 } 347 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 348 if (pr == NULL) 349 panic("ip_init"); 350 for (i = 0; i < IPPROTO_MAX; i++) 351 ip_protox[i] = pr - inetsw; 352 for (pr = inetdomain.dom_protosw; 353 pr < inetdomain.dom_protoswNPROTOSW; pr++) { 354 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) { 355 if (pr->pr_protocol != IPPROTO_RAW) 356 ip_protox[pr->pr_protocol] = pr - inetsw; 357 } 358 } 359 360 inet_pfil_hook.ph_type = PFIL_TYPE_AF; 361 inet_pfil_hook.ph_af = AF_INET; 362 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) { 363 kprintf("%s: WARNING: unable to register pfil hook, " 364 "error %d\n", __func__, i); 365 } 366 367 maxnipq = (nmbclusters / 32) / ncpus2; 368 if (maxnipq < MAXIPFRAG_MIN) 369 maxnipq = MAXIPFRAG_MIN; 370 maxfragsperpacket = 16; 371 372 ip_id = time_second & 0xffff; /* time_second survives reboots */ 373 374 for (cpu = 0; cpu < ncpus; ++cpu) { 375 /* 376 * Initialize IP statistics counters for each CPU. 377 */ 378 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats)); 379 380 /* 381 * Preallocate mbuf template for forwarding 382 */ 383 MGETHDR(ipforward_mtemp[cpu], M_WAITOK, MT_DATA); 384 385 /* 386 * Initialize per-cpu ip fragments queues 387 */ 388 for (i = 0; i < IPREASS_NHASH; i++) { 389 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[cpu]; 390 391 TAILQ_INIT(&fragq->ipq[i]); 392 netmsg_init(&fragq->timeo_netmsg, NULL, 393 &netisr_adone_rport, MSGF_PRIORITY, 394 ipfrag_timeo_dispatch); 395 netmsg_init(&fragq->drain_netmsg, NULL, 396 &netisr_adone_rport, MSGF_PRIORITY, 397 ipfrag_drain_dispatch); 398 } 399 } 400 401 netisr_register(NETISR_IP, ip_input_handler, ip_hashfn); 402 netisr_register_hashcheck(NETISR_IP, ip_hashcheck); 403 } 404 405 /* Do transport protocol processing. */ 406 static void 407 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip) 408 { 409 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]]; 410 411 /* 412 * Switch out to protocol's input routine. 413 */ 414 PR_GET_MPLOCK(pr); 415 pr->pr_input(&m, &hlen, ip->ip_p); 416 PR_REL_MPLOCK(pr); 417 } 418 419 static void 420 transport_processing_handler(netmsg_t msg) 421 { 422 struct netmsg_packet *pmsg = &msg->packet; 423 struct ip *ip; 424 int hlen; 425 426 ip = mtod(pmsg->nm_packet, struct ip *); 427 hlen = pmsg->base.lmsg.u.ms_result; 428 429 transport_processing_oncpu(pmsg->nm_packet, hlen, ip); 430 /* msg was embedded in the mbuf, do not reply! */ 431 } 432 433 static void 434 ip_input_handler(netmsg_t msg) 435 { 436 ip_input(msg->packet.nm_packet); 437 /* msg was embedded in the mbuf, do not reply! */ 438 } 439 440 /* 441 * IP input routine. Checksum and byte swap header. If fragmented 442 * try to reassemble. Process options. Pass to next level. 443 */ 444 void 445 ip_input(struct mbuf *m) 446 { 447 struct ip *ip; 448 struct in_ifaddr *ia = NULL; 449 struct in_ifaddr_container *iac; 450 int hlen, checkif; 451 u_short sum; 452 struct in_addr pkt_dst; 453 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */ 454 struct in_addr odst; /* original dst address(NAT) */ 455 struct m_tag *mtag; 456 struct sockaddr_in *next_hop = NULL; 457 lwkt_port_t port; 458 #ifdef FAST_IPSEC 459 struct tdb_ident *tdbi; 460 struct secpolicy *sp; 461 int error; 462 #endif 463 464 M_ASSERTPKTHDR(m); 465 466 /* 467 * This routine is called from numerous places which may not have 468 * characterized the packet. 469 */ 470 ip = mtod(m, struct ip *); 471 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 472 ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) { 473 /* 474 * Force hash recalculation for fragments and multicast 475 * packets; hardware may not do it correctly. 476 * XXX add flag to indicate the hash is from hardware 477 */ 478 m->m_flags &= ~M_HASH; 479 } 480 if ((m->m_flags & M_HASH) == 0) { 481 ip_hashfn(&m, 0); 482 if (m == NULL) 483 return; 484 KKASSERT(m->m_flags & M_HASH); 485 486 if (&curthread->td_msgport != 487 netisr_hashport(m->m_pkthdr.hash)) { 488 netisr_queue(NETISR_IP, m); 489 /* Requeued to other netisr msgport; done */ 490 return; 491 } 492 493 /* mbuf could have been changed */ 494 ip = mtod(m, struct ip *); 495 } 496 497 /* 498 * Pull out certain tags 499 */ 500 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 501 /* Next hop */ 502 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 503 KKASSERT(mtag != NULL); 504 next_hop = m_tag_data(mtag); 505 } 506 507 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 508 /* dummynet already filtered us */ 509 ip = mtod(m, struct ip *); 510 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 511 goto iphack; 512 } 513 514 ipstat.ips_total++; 515 516 /* length checks already done in ip_hashfn() */ 517 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf")); 518 519 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) { 520 ipstat.ips_badvers++; 521 goto bad; 522 } 523 524 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 525 /* length checks already done in ip_hashfn() */ 526 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small")); 527 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf")); 528 529 /* 127/8 must not appear on wire - RFC1122 */ 530 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 531 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 532 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) { 533 ipstat.ips_badaddr++; 534 goto bad; 535 } 536 } 537 538 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { 539 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); 540 } else { 541 if (hlen == sizeof(struct ip)) 542 sum = in_cksum_hdr(ip); 543 else 544 sum = in_cksum(m, hlen); 545 } 546 if (sum != 0) { 547 ipstat.ips_badsum++; 548 goto bad; 549 } 550 551 #ifdef ALTQ 552 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) { 553 /* packet is dropped by traffic conditioner */ 554 return; 555 } 556 #endif 557 /* 558 * Convert fields to host representation. 559 */ 560 ip->ip_len = ntohs(ip->ip_len); 561 ip->ip_off = ntohs(ip->ip_off); 562 563 /* length checks already done in ip_hashfn() */ 564 KASSERT(ip->ip_len >= hlen, ("total length less then header length")); 565 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short")); 566 567 /* 568 * Trim mbufs if longer than the IP header would have us expect. 569 */ 570 if (m->m_pkthdr.len > ip->ip_len) { 571 if (m->m_len == m->m_pkthdr.len) { 572 m->m_len = ip->ip_len; 573 m->m_pkthdr.len = ip->ip_len; 574 } else { 575 m_adj(m, ip->ip_len - m->m_pkthdr.len); 576 } 577 } 578 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF) 579 /* 580 * Bypass packet filtering for packets from a tunnel (gif). 581 */ 582 if (ipsec_gethist(m, NULL)) 583 goto pass; 584 #endif 585 586 /* 587 * IpHack's section. 588 * Right now when no processing on packet has done 589 * and it is still fresh out of network we do our black 590 * deals with it. 591 * - Firewall: deny/allow/divert 592 * - Xlate: translate packet's addr/port (NAT). 593 * - Pipe: pass pkt through dummynet. 594 * - Wrap: fake packet's addr/port <unimpl.> 595 * - Encapsulate: put it in another IP and send out. <unimp.> 596 */ 597 598 iphack: 599 /* 600 * If we've been forwarded from the output side, then 601 * skip the firewall a second time 602 */ 603 if (next_hop != NULL) 604 goto ours; 605 606 /* No pfil hooks */ 607 if (!pfil_has_hooks(&inet_pfil_hook)) { 608 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 609 /* 610 * Strip dummynet tags from stranded packets 611 */ 612 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 613 KKASSERT(mtag != NULL); 614 m_tag_delete(m, mtag); 615 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 616 } 617 goto pass; 618 } 619 620 /* 621 * Run through list of hooks for input packets. 622 * 623 * NOTE! If the packet is rewritten pf/ipfw/whoever must 624 * clear M_HASH. 625 */ 626 odst = ip->ip_dst; 627 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 628 return; 629 if (m == NULL) /* consumed by filter */ 630 return; 631 ip = mtod(m, struct ip *); 632 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 633 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr); 634 635 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 636 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 637 KKASSERT(mtag != NULL); 638 next_hop = m_tag_data(mtag); 639 } 640 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 641 ip_dn_queue(m); 642 return; 643 } 644 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) { 645 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH; 646 } 647 pass: 648 /* 649 * Process options and, if not destined for us, 650 * ship it on. ip_dooptions returns 1 when an 651 * error was detected (causing an icmp message 652 * to be sent and the original packet to be freed). 653 */ 654 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop)) 655 return; 656 657 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no 658 * matter if it is destined to another node, or whether it is 659 * a multicast one, RSVP wants it! and prevents it from being forwarded 660 * anywhere else. Also checks if the rsvp daemon is running before 661 * grabbing the packet. 662 */ 663 if (rsvp_on && ip->ip_p == IPPROTO_RSVP) 664 goto ours; 665 666 /* 667 * Check our list of addresses, to see if the packet is for us. 668 * If we don't have any addresses, assume any unicast packet 669 * we receive might be for us (and let the upper layers deal 670 * with it). 671 */ 672 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) && 673 !(m->m_flags & (M_MCAST | M_BCAST))) 674 goto ours; 675 676 /* 677 * Cache the destination address of the packet; this may be 678 * changed by use of 'ipfw fwd'. 679 */ 680 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 681 682 /* 683 * Enable a consistency check between the destination address 684 * and the arrival interface for a unicast packet (the RFC 1122 685 * strong ES model) if IP forwarding is disabled and the packet 686 * is not locally generated and the packet is not subject to 687 * 'ipfw fwd'. 688 * 689 * XXX - Checking also should be disabled if the destination 690 * address is ipnat'ed to a different interface. 691 * 692 * XXX - Checking is incompatible with IP aliases added 693 * to the loopback interface instead of the interface where 694 * the packets are received. 695 */ 696 checkif = ip_checkinterface && 697 !ipforwarding && 698 m->m_pkthdr.rcvif != NULL && 699 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 700 next_hop == NULL; 701 702 /* 703 * Check for exact addresses in the hash bucket. 704 */ 705 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) { 706 ia = iac->ia; 707 708 /* 709 * If the address matches, verify that the packet 710 * arrived via the correct interface if checking is 711 * enabled. 712 */ 713 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr && 714 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) 715 goto ours; 716 } 717 ia = NULL; 718 719 /* 720 * Check for broadcast addresses. 721 * 722 * Only accept broadcast packets that arrive via the matching 723 * interface. Reception of forwarded directed broadcasts would 724 * be handled via ip_forward() and ether_output() with the loopback 725 * into the stack for SIMPLEX interfaces handled by ether_output(). 726 */ 727 if (m->m_pkthdr.rcvif != NULL && 728 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 729 struct ifaddr_container *ifac; 730 731 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid], 732 ifa_link) { 733 struct ifaddr *ifa = ifac->ifa; 734 735 if (ifa->ifa_addr == NULL) /* shutdown/startup race */ 736 continue; 737 if (ifa->ifa_addr->sa_family != AF_INET) 738 continue; 739 ia = ifatoia(ifa); 740 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 741 pkt_dst.s_addr) 742 goto ours; 743 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr) 744 goto ours; 745 #ifdef BOOTP_COMPAT 746 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) 747 goto ours; 748 #endif 749 } 750 } 751 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 752 struct in_multi *inm; 753 754 if (ip_mrouter != NULL) { 755 /* XXX Multicast routing is not MPSAFE yet */ 756 get_mplock(); 757 758 /* 759 * If we are acting as a multicast router, all 760 * incoming multicast packets are passed to the 761 * kernel-level multicast forwarding function. 762 * The packet is returned (relatively) intact; if 763 * ip_mforward() returns a non-zero value, the packet 764 * must be discarded, else it may be accepted below. 765 */ 766 if (ip_mforward != NULL && 767 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) { 768 rel_mplock(); 769 ipstat.ips_cantforward++; 770 m_freem(m); 771 return; 772 } 773 774 rel_mplock(); 775 776 /* 777 * The process-level routing daemon needs to receive 778 * all multicast IGMP packets, whether or not this 779 * host belongs to their destination groups. 780 */ 781 if (ip->ip_p == IPPROTO_IGMP) 782 goto ours; 783 ipstat.ips_forward++; 784 } 785 /* 786 * See if we belong to the destination multicast group on the 787 * arrival interface. 788 */ 789 inm = IN_LOOKUP_MULTI(&ip->ip_dst, m->m_pkthdr.rcvif); 790 if (inm == NULL) { 791 ipstat.ips_notmember++; 792 m_freem(m); 793 return; 794 } 795 goto ours; 796 } 797 if (ip->ip_dst.s_addr == INADDR_BROADCAST) 798 goto ours; 799 if (ip->ip_dst.s_addr == INADDR_ANY) 800 goto ours; 801 802 /* 803 * FAITH(Firewall Aided Internet Translator) 804 */ 805 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { 806 if (ip_keepfaith) { 807 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP) 808 goto ours; 809 } 810 m_freem(m); 811 return; 812 } 813 814 /* 815 * Not for us; forward if possible and desirable. 816 */ 817 if (!ipforwarding) { 818 ipstat.ips_cantforward++; 819 m_freem(m); 820 } else { 821 #ifdef IPSEC 822 /* 823 * Enforce inbound IPsec SPD. 824 */ 825 if (ipsec4_in_reject(m, NULL)) { 826 ipsecstat.in_polvio++; 827 goto bad; 828 } 829 #endif 830 #ifdef FAST_IPSEC 831 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 832 crit_enter(); 833 if (mtag != NULL) { 834 tdbi = (struct tdb_ident *)m_tag_data(mtag); 835 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 836 } else { 837 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 838 IP_FORWARDING, &error); 839 } 840 if (sp == NULL) { /* NB: can happen if error */ 841 crit_exit(); 842 /*XXX error stat???*/ 843 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/ 844 goto bad; 845 } 846 847 /* 848 * Check security policy against packet attributes. 849 */ 850 error = ipsec_in_reject(sp, m); 851 KEY_FREESP(&sp); 852 crit_exit(); 853 if (error) { 854 ipstat.ips_cantforward++; 855 goto bad; 856 } 857 #endif 858 ip_forward(m, using_srcrt, next_hop); 859 } 860 return; 861 862 ours: 863 864 /* 865 * IPSTEALTH: Process non-routing options only 866 * if the packet is destined for us. 867 */ 868 if (ipstealth && 869 hlen > sizeof(struct ip) && 870 ip_dooptions(m, 1, next_hop)) 871 return; 872 873 /* Count the packet in the ip address stats */ 874 if (ia != NULL) { 875 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1); 876 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len); 877 } 878 879 /* 880 * If offset or IP_MF are set, must reassemble. 881 * Otherwise, nothing need be done. 882 * (We could look in the reassembly queue to see 883 * if the packet was previously fragmented, 884 * but it's not worth the time; just let them time out.) 885 */ 886 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 887 /* 888 * Attempt reassembly; if it succeeds, proceed. ip_reass() 889 * will return a different mbuf. 890 * 891 * NOTE: ip_reass() returns m with M_HASH cleared to force 892 * us to recharacterize the packet. 893 */ 894 m = ip_reass(m); 895 if (m == NULL) 896 return; 897 ip = mtod(m, struct ip *); 898 899 /* Get the header length of the reassembled packet */ 900 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 901 } else { 902 ip->ip_len -= hlen; 903 } 904 905 #ifdef IPSEC 906 /* 907 * enforce IPsec policy checking if we are seeing last header. 908 * note that we do not visit this with protocols with pcb layer 909 * code - like udp/tcp/raw ip. 910 */ 911 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) && 912 ipsec4_in_reject(m, NULL)) { 913 ipsecstat.in_polvio++; 914 goto bad; 915 } 916 #endif 917 #ifdef FAST_IPSEC 918 /* 919 * enforce IPsec policy checking if we are seeing last header. 920 * note that we do not visit this with protocols with pcb layer 921 * code - like udp/tcp/raw ip. 922 */ 923 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) { 924 /* 925 * Check if the packet has already had IPsec processing 926 * done. If so, then just pass it along. This tag gets 927 * set during AH, ESP, etc. input handling, before the 928 * packet is returned to the ip input queue for delivery. 929 */ 930 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 931 crit_enter(); 932 if (mtag != NULL) { 933 tdbi = (struct tdb_ident *)m_tag_data(mtag); 934 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 935 } else { 936 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 937 IP_FORWARDING, &error); 938 } 939 if (sp != NULL) { 940 /* 941 * Check security policy against packet attributes. 942 */ 943 error = ipsec_in_reject(sp, m); 944 KEY_FREESP(&sp); 945 } else { 946 /* XXX error stat??? */ 947 error = EINVAL; 948 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/ 949 crit_exit(); 950 goto bad; 951 } 952 crit_exit(); 953 if (error) 954 goto bad; 955 } 956 #endif /* FAST_IPSEC */ 957 958 /* 959 * We must forward the packet to the correct protocol thread if 960 * we are not already in it. 961 * 962 * NOTE: ip_len is now in host form. ip_len is not adjusted 963 * further for protocol processing, instead we pass hlen 964 * to the protosw and let it deal with it. 965 */ 966 ipstat.ips_delivered++; 967 968 if ((m->m_flags & M_HASH) == 0) { 969 #ifdef RSS_DEBUG 970 atomic_add_long(&ip_rehash_count, 1); 971 #endif 972 ip->ip_len = htons(ip->ip_len + hlen); 973 ip->ip_off = htons(ip->ip_off); 974 975 ip_hashfn(&m, 0); 976 if (m == NULL) 977 return; 978 979 ip = mtod(m, struct ip *); 980 ip->ip_len = ntohs(ip->ip_len) - hlen; 981 ip->ip_off = ntohs(ip->ip_off); 982 KKASSERT(m->m_flags & M_HASH); 983 } 984 port = netisr_hashport(m->m_pkthdr.hash); 985 986 if (port != &curthread->td_msgport) { 987 struct netmsg_packet *pmsg; 988 989 #ifdef RSS_DEBUG 990 atomic_add_long(&ip_dispatch_slow, 1); 991 #endif 992 993 pmsg = &m->m_hdr.mh_netmsg; 994 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 995 0, transport_processing_handler); 996 pmsg->nm_packet = m; 997 pmsg->base.lmsg.u.ms_result = hlen; 998 lwkt_sendmsg(port, &pmsg->base.lmsg); 999 } else { 1000 #ifdef RSS_DEBUG 1001 atomic_add_long(&ip_dispatch_fast, 1); 1002 #endif 1003 transport_processing_oncpu(m, hlen, ip); 1004 } 1005 return; 1006 1007 bad: 1008 m_freem(m); 1009 } 1010 1011 /* 1012 * Take incoming datagram fragment and try to reassemble it into 1013 * whole datagram. If a chain for reassembly of this datagram already 1014 * exists, then it is given as fp; otherwise have to make a chain. 1015 */ 1016 struct mbuf * 1017 ip_reass(struct mbuf *m) 1018 { 1019 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 1020 struct ip *ip = mtod(m, struct ip *); 1021 struct mbuf *p = NULL, *q, *nq; 1022 struct mbuf *n; 1023 struct ipq *fp = NULL; 1024 struct ipqhead *head; 1025 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1026 int i, next; 1027 u_short sum; 1028 1029 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */ 1030 if (maxnipq == 0 || maxfragsperpacket == 0) { 1031 ipstat.ips_fragments++; 1032 ipstat.ips_fragdropped++; 1033 m_freem(m); 1034 return NULL; 1035 } 1036 1037 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); 1038 /* 1039 * Look for queue of fragments of this datagram. 1040 */ 1041 head = &fragq->ipq[sum]; 1042 TAILQ_FOREACH(fp, head, ipq_list) { 1043 if (ip->ip_id == fp->ipq_id && 1044 ip->ip_src.s_addr == fp->ipq_src.s_addr && 1045 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 1046 ip->ip_p == fp->ipq_p) 1047 goto found; 1048 } 1049 1050 fp = NULL; 1051 1052 /* 1053 * Enforce upper bound on number of fragmented packets 1054 * for which we attempt reassembly; 1055 * If maxnipq is -1, accept all fragments without limitation. 1056 */ 1057 if (fragq->nipq > maxnipq && maxnipq > 0) { 1058 /* 1059 * drop something from the tail of the current queue 1060 * before proceeding further 1061 */ 1062 struct ipq *q = TAILQ_LAST(head, ipqhead); 1063 if (q == NULL) { 1064 /* 1065 * The current queue is empty, 1066 * so drop from one of the others. 1067 */ 1068 for (i = 0; i < IPREASS_NHASH; i++) { 1069 struct ipq *r = TAILQ_LAST(&fragq->ipq[i], 1070 ipqhead); 1071 if (r) { 1072 ipstat.ips_fragtimeout += r->ipq_nfrags; 1073 ip_freef(fragq, &fragq->ipq[i], r); 1074 break; 1075 } 1076 } 1077 } else { 1078 ipstat.ips_fragtimeout += q->ipq_nfrags; 1079 ip_freef(fragq, head, q); 1080 } 1081 } 1082 found: 1083 /* 1084 * Adjust ip_len to not reflect header, 1085 * convert offset of this to bytes. 1086 */ 1087 ip->ip_len -= hlen; 1088 if (ip->ip_off & IP_MF) { 1089 /* 1090 * Make sure that fragments have a data length 1091 * that's a non-zero multiple of 8 bytes. 1092 */ 1093 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 1094 ipstat.ips_toosmall++; /* XXX */ 1095 m_freem(m); 1096 goto done; 1097 } 1098 m->m_flags |= M_FRAG; 1099 } else { 1100 m->m_flags &= ~M_FRAG; 1101 } 1102 ip->ip_off <<= 3; 1103 1104 ipstat.ips_fragments++; 1105 m->m_pkthdr.header = ip; 1106 1107 /* 1108 * If the hardware has not done csum over this fragment 1109 * then csum_data is not valid at all. 1110 */ 1111 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) 1112 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) { 1113 m->m_pkthdr.csum_data = 0; 1114 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 1115 } 1116 1117 /* 1118 * Presence of header sizes in mbufs 1119 * would confuse code below. 1120 */ 1121 m->m_data += hlen; 1122 m->m_len -= hlen; 1123 1124 /* 1125 * If first fragment to arrive, create a reassembly queue. 1126 */ 1127 if (fp == NULL) { 1128 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL) 1129 goto dropfrag; 1130 TAILQ_INSERT_HEAD(head, fp, ipq_list); 1131 fragq->nipq++; 1132 fp->ipq_nfrags = 1; 1133 fp->ipq_ttl = IPFRAGTTL; 1134 fp->ipq_p = ip->ip_p; 1135 fp->ipq_id = ip->ip_id; 1136 fp->ipq_src = ip->ip_src; 1137 fp->ipq_dst = ip->ip_dst; 1138 fp->ipq_frags = m; 1139 m->m_nextpkt = NULL; 1140 goto inserted; 1141 } 1142 fp->ipq_nfrags++; 1143 1144 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header)) 1145 1146 /* 1147 * Find a segment which begins after this one does. 1148 */ 1149 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1150 if (GETIP(q)->ip_off > ip->ip_off) 1151 break; 1152 } 1153 1154 /* 1155 * If there is a preceding segment, it may provide some of 1156 * our data already. If so, drop the data from the incoming 1157 * segment. If it provides all of our data, drop us, otherwise 1158 * stick new segment in the proper place. 1159 * 1160 * If some of the data is dropped from the the preceding 1161 * segment, then it's checksum is invalidated. 1162 */ 1163 if (p) { 1164 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off; 1165 if (i > 0) { 1166 if (i >= ip->ip_len) 1167 goto dropfrag; 1168 m_adj(m, i); 1169 m->m_pkthdr.csum_flags = 0; 1170 ip->ip_off += i; 1171 ip->ip_len -= i; 1172 } 1173 m->m_nextpkt = p->m_nextpkt; 1174 p->m_nextpkt = m; 1175 } else { 1176 m->m_nextpkt = fp->ipq_frags; 1177 fp->ipq_frags = m; 1178 } 1179 1180 /* 1181 * While we overlap succeeding segments trim them or, 1182 * if they are completely covered, dequeue them. 1183 */ 1184 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off; 1185 q = nq) { 1186 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off; 1187 if (i < GETIP(q)->ip_len) { 1188 GETIP(q)->ip_len -= i; 1189 GETIP(q)->ip_off += i; 1190 m_adj(q, i); 1191 q->m_pkthdr.csum_flags = 0; 1192 break; 1193 } 1194 nq = q->m_nextpkt; 1195 m->m_nextpkt = nq; 1196 ipstat.ips_fragdropped++; 1197 fp->ipq_nfrags--; 1198 q->m_nextpkt = NULL; 1199 m_freem(q); 1200 } 1201 1202 inserted: 1203 /* 1204 * Check for complete reassembly and perform frag per packet 1205 * limiting. 1206 * 1207 * Frag limiting is performed here so that the nth frag has 1208 * a chance to complete the packet before we drop the packet. 1209 * As a result, n+1 frags are actually allowed per packet, but 1210 * only n will ever be stored. (n = maxfragsperpacket.) 1211 * 1212 */ 1213 next = 0; 1214 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1215 if (GETIP(q)->ip_off != next) { 1216 if (fp->ipq_nfrags > maxfragsperpacket) { 1217 ipstat.ips_fragdropped += fp->ipq_nfrags; 1218 ip_freef(fragq, head, fp); 1219 } 1220 goto done; 1221 } 1222 next += GETIP(q)->ip_len; 1223 } 1224 /* Make sure the last packet didn't have the IP_MF flag */ 1225 if (p->m_flags & M_FRAG) { 1226 if (fp->ipq_nfrags > maxfragsperpacket) { 1227 ipstat.ips_fragdropped += fp->ipq_nfrags; 1228 ip_freef(fragq, head, fp); 1229 } 1230 goto done; 1231 } 1232 1233 /* 1234 * Reassembly is complete. Make sure the packet is a sane size. 1235 */ 1236 q = fp->ipq_frags; 1237 ip = GETIP(q); 1238 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) { 1239 ipstat.ips_toolong++; 1240 ipstat.ips_fragdropped += fp->ipq_nfrags; 1241 ip_freef(fragq, head, fp); 1242 goto done; 1243 } 1244 1245 /* 1246 * Concatenate fragments. 1247 */ 1248 m = q; 1249 n = m->m_next; 1250 m->m_next = NULL; 1251 m_cat(m, n); 1252 nq = q->m_nextpkt; 1253 q->m_nextpkt = NULL; 1254 for (q = nq; q != NULL; q = nq) { 1255 nq = q->m_nextpkt; 1256 q->m_nextpkt = NULL; 1257 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 1258 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 1259 m_cat(m, q); 1260 } 1261 1262 /* 1263 * Clean up the 1's complement checksum. Carry over 16 bits must 1264 * be added back. This assumes no more then 65535 packet fragments 1265 * were reassembled. A second carry can also occur (but not a third). 1266 */ 1267 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + 1268 (m->m_pkthdr.csum_data >> 16); 1269 if (m->m_pkthdr.csum_data > 0xFFFF) 1270 m->m_pkthdr.csum_data -= 0xFFFF; 1271 1272 /* 1273 * Create header for new ip packet by 1274 * modifying header of first packet; 1275 * dequeue and discard fragment reassembly header. 1276 * Make header visible. 1277 */ 1278 ip->ip_len = next; 1279 ip->ip_src = fp->ipq_src; 1280 ip->ip_dst = fp->ipq_dst; 1281 TAILQ_REMOVE(head, fp, ipq_list); 1282 fragq->nipq--; 1283 mpipe_free(&ipq_mpipe, fp); 1284 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2); 1285 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2); 1286 /* some debugging cruft by sklower, below, will go away soon */ 1287 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 1288 int plen = 0; 1289 1290 for (n = m; n; n = n->m_next) 1291 plen += n->m_len; 1292 m->m_pkthdr.len = plen; 1293 } 1294 1295 /* 1296 * Reassembly complete, return the next protocol. 1297 * 1298 * Be sure to clear M_HASH to force the packet 1299 * to be re-characterized. 1300 * 1301 * Clear M_FRAG, we are no longer a fragment. 1302 */ 1303 m->m_flags &= ~(M_HASH | M_FRAG); 1304 1305 ipstat.ips_reassembled++; 1306 return (m); 1307 1308 dropfrag: 1309 ipstat.ips_fragdropped++; 1310 if (fp != NULL) 1311 fp->ipq_nfrags--; 1312 m_freem(m); 1313 done: 1314 return (NULL); 1315 1316 #undef GETIP 1317 } 1318 1319 /* 1320 * Free a fragment reassembly header and all 1321 * associated datagrams. 1322 */ 1323 static void 1324 ip_freef(struct ipfrag_queue *fragq, struct ipqhead *fhp, struct ipq *fp) 1325 { 1326 struct mbuf *q; 1327 1328 /* 1329 * Remove first to protect against blocking 1330 */ 1331 TAILQ_REMOVE(fhp, fp, ipq_list); 1332 1333 /* 1334 * Clean out at our leisure 1335 */ 1336 while (fp->ipq_frags) { 1337 q = fp->ipq_frags; 1338 fp->ipq_frags = q->m_nextpkt; 1339 q->m_nextpkt = NULL; 1340 m_freem(q); 1341 } 1342 mpipe_free(&ipq_mpipe, fp); 1343 fragq->nipq--; 1344 } 1345 1346 /* 1347 * If a timer expires on a reassembly queue, discard it. 1348 */ 1349 static void 1350 ipfrag_timeo_dispatch(netmsg_t nmsg) 1351 { 1352 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 1353 struct ipq *fp, *fp_temp; 1354 struct ipqhead *head; 1355 int i; 1356 1357 crit_enter(); 1358 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ 1359 crit_exit(); 1360 1361 for (i = 0; i < IPREASS_NHASH; i++) { 1362 head = &fragq->ipq[i]; 1363 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) { 1364 if (--fp->ipq_ttl == 0) { 1365 ipstat.ips_fragtimeout += fp->ipq_nfrags; 1366 ip_freef(fragq, head, fp); 1367 } 1368 } 1369 } 1370 /* 1371 * If we are over the maximum number of fragments 1372 * (due to the limit being lowered), drain off 1373 * enough to get down to the new limit. 1374 */ 1375 if (maxnipq >= 0 && fragq->nipq > maxnipq) { 1376 for (i = 0; i < IPREASS_NHASH; i++) { 1377 head = &fragq->ipq[i]; 1378 while (fragq->nipq > maxnipq && !TAILQ_EMPTY(head)) { 1379 ipstat.ips_fragdropped += 1380 TAILQ_FIRST(head)->ipq_nfrags; 1381 ip_freef(fragq, head, TAILQ_FIRST(head)); 1382 } 1383 } 1384 } 1385 } 1386 1387 static void 1388 ipfrag_timeo_ipi(void *arg __unused) 1389 { 1390 int cpu = mycpuid; 1391 struct lwkt_msg *msg = &ipfrag_queue_pcpu[cpu].timeo_netmsg.lmsg; 1392 1393 crit_enter(); 1394 if (msg->ms_flags & MSGF_DONE) 1395 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); 1396 crit_exit(); 1397 } 1398 1399 static void 1400 ipfrag_slowtimo(void) 1401 { 1402 cpumask_t mask; 1403 1404 CPUMASK_ASSBMASK(mask, ncpus); 1405 CPUMASK_ANDMASK(mask, smp_active_mask); 1406 if (CPUMASK_TESTNZERO(mask)) 1407 lwkt_send_ipiq_mask(mask, ipfrag_timeo_ipi, NULL); 1408 } 1409 1410 /* 1411 * IP timer processing 1412 */ 1413 void 1414 ip_slowtimo(void) 1415 { 1416 ipfrag_slowtimo(); 1417 ipflow_slowtimo(); 1418 } 1419 1420 /* 1421 * Drain off all datagram fragments. 1422 */ 1423 static void 1424 ipfrag_drain_dispatch(netmsg_t nmsg) 1425 { 1426 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 1427 struct ipqhead *head; 1428 int i; 1429 1430 crit_enter(); 1431 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ 1432 crit_exit(); 1433 1434 for (i = 0; i < IPREASS_NHASH; i++) { 1435 head = &fragq->ipq[i]; 1436 while (!TAILQ_EMPTY(head)) { 1437 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags; 1438 ip_freef(fragq, head, TAILQ_FIRST(head)); 1439 } 1440 } 1441 } 1442 1443 static void 1444 ipfrag_drain_ipi(void *arg __unused) 1445 { 1446 int cpu = mycpuid; 1447 struct lwkt_msg *msg = &ipfrag_queue_pcpu[cpu].drain_netmsg.lmsg; 1448 1449 crit_enter(); 1450 if (msg->ms_flags & MSGF_DONE) 1451 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); 1452 crit_exit(); 1453 } 1454 1455 static void 1456 ipfrag_drain(void) 1457 { 1458 cpumask_t mask; 1459 1460 CPUMASK_ASSBMASK(mask, ncpus); 1461 CPUMASK_ANDMASK(mask, smp_active_mask); 1462 if (CPUMASK_TESTNZERO(mask)) 1463 lwkt_send_ipiq_mask(mask, ipfrag_drain_ipi, NULL); 1464 } 1465 1466 void 1467 ip_drain(void) 1468 { 1469 ipfrag_drain(); 1470 in_rtqdrain(); 1471 } 1472 1473 /* 1474 * Do option processing on a datagram, 1475 * possibly discarding it if bad options are encountered, 1476 * or forwarding it if source-routed. 1477 * The pass argument is used when operating in the IPSTEALTH 1478 * mode to tell what options to process: 1479 * [LS]SRR (pass 0) or the others (pass 1). 1480 * The reason for as many as two passes is that when doing IPSTEALTH, 1481 * non-routing options should be processed only if the packet is for us. 1482 * Returns 1 if packet has been forwarded/freed, 1483 * 0 if the packet should be processed further. 1484 */ 1485 static int 1486 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop) 1487 { 1488 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET }; 1489 struct ip *ip = mtod(m, struct ip *); 1490 u_char *cp; 1491 struct in_ifaddr *ia; 1492 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB; 1493 boolean_t forward = FALSE; 1494 struct in_addr *sin, dst; 1495 n_time ntime; 1496 1497 dst = ip->ip_dst; 1498 cp = (u_char *)(ip + 1); 1499 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1500 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1501 opt = cp[IPOPT_OPTVAL]; 1502 if (opt == IPOPT_EOL) 1503 break; 1504 if (opt == IPOPT_NOP) 1505 optlen = 1; 1506 else { 1507 if (cnt < IPOPT_OLEN + sizeof(*cp)) { 1508 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1509 goto bad; 1510 } 1511 optlen = cp[IPOPT_OLEN]; 1512 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 1513 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1514 goto bad; 1515 } 1516 } 1517 switch (opt) { 1518 1519 default: 1520 break; 1521 1522 /* 1523 * Source routing with record. 1524 * Find interface with current destination address. 1525 * If none on this machine then drop if strictly routed, 1526 * or do nothing if loosely routed. 1527 * Record interface address and bring up next address 1528 * component. If strictly routed make sure next 1529 * address is on directly accessible net. 1530 */ 1531 case IPOPT_LSRR: 1532 case IPOPT_SSRR: 1533 if (ipstealth && pass > 0) 1534 break; 1535 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1536 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1537 goto bad; 1538 } 1539 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1540 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1541 goto bad; 1542 } 1543 ipaddr.sin_addr = ip->ip_dst; 1544 ia = (struct in_ifaddr *) 1545 ifa_ifwithaddr((struct sockaddr *)&ipaddr); 1546 if (ia == NULL) { 1547 if (opt == IPOPT_SSRR) { 1548 type = ICMP_UNREACH; 1549 code = ICMP_UNREACH_SRCFAIL; 1550 goto bad; 1551 } 1552 if (!ip_dosourceroute) 1553 goto nosourcerouting; 1554 /* 1555 * Loose routing, and not at next destination 1556 * yet; nothing to do except forward. 1557 */ 1558 break; 1559 } 1560 off--; /* 0 origin */ 1561 if (off > optlen - (int)sizeof(struct in_addr)) { 1562 /* 1563 * End of source route. Should be for us. 1564 */ 1565 if (!ip_acceptsourceroute) 1566 goto nosourcerouting; 1567 save_rte(m, cp, ip->ip_src); 1568 break; 1569 } 1570 if (ipstealth) 1571 goto dropit; 1572 if (!ip_dosourceroute) { 1573 if (ipforwarding) { 1574 char buf[sizeof "aaa.bbb.ccc.ddd"]; 1575 1576 /* 1577 * Acting as a router, so generate ICMP 1578 */ 1579 nosourcerouting: 1580 strcpy(buf, inet_ntoa(ip->ip_dst)); 1581 log(LOG_WARNING, 1582 "attempted source route from %s to %s\n", 1583 inet_ntoa(ip->ip_src), buf); 1584 type = ICMP_UNREACH; 1585 code = ICMP_UNREACH_SRCFAIL; 1586 goto bad; 1587 } else { 1588 /* 1589 * Not acting as a router, 1590 * so silently drop. 1591 */ 1592 dropit: 1593 ipstat.ips_cantforward++; 1594 m_freem(m); 1595 return (1); 1596 } 1597 } 1598 1599 /* 1600 * locate outgoing interface 1601 */ 1602 memcpy(&ipaddr.sin_addr, cp + off, 1603 sizeof ipaddr.sin_addr); 1604 1605 if (opt == IPOPT_SSRR) { 1606 #define INA struct in_ifaddr * 1607 #define SA struct sockaddr * 1608 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) 1609 == NULL) 1610 ia = (INA)ifa_ifwithnet((SA)&ipaddr); 1611 } else { 1612 ia = ip_rtaddr(ipaddr.sin_addr, NULL); 1613 } 1614 if (ia == NULL) { 1615 type = ICMP_UNREACH; 1616 code = ICMP_UNREACH_SRCFAIL; 1617 goto bad; 1618 } 1619 ip->ip_dst = ipaddr.sin_addr; 1620 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1621 sizeof(struct in_addr)); 1622 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1623 /* 1624 * Let ip_intr's mcast routing check handle mcast pkts 1625 */ 1626 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); 1627 break; 1628 1629 case IPOPT_RR: 1630 if (ipstealth && pass == 0) 1631 break; 1632 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1633 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1634 goto bad; 1635 } 1636 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1637 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1638 goto bad; 1639 } 1640 /* 1641 * If no space remains, ignore. 1642 */ 1643 off--; /* 0 origin */ 1644 if (off > optlen - (int)sizeof(struct in_addr)) 1645 break; 1646 memcpy(&ipaddr.sin_addr, &ip->ip_dst, 1647 sizeof ipaddr.sin_addr); 1648 /* 1649 * locate outgoing interface; if we're the destination, 1650 * use the incoming interface (should be same). 1651 */ 1652 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL && 1653 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) { 1654 type = ICMP_UNREACH; 1655 code = ICMP_UNREACH_HOST; 1656 goto bad; 1657 } 1658 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1659 sizeof(struct in_addr)); 1660 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1661 break; 1662 1663 case IPOPT_TS: 1664 if (ipstealth && pass == 0) 1665 break; 1666 code = cp - (u_char *)ip; 1667 if (optlen < 4 || optlen > 40) { 1668 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1669 goto bad; 1670 } 1671 if ((off = cp[IPOPT_OFFSET]) < 5) { 1672 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1673 goto bad; 1674 } 1675 if (off > optlen - (int)sizeof(int32_t)) { 1676 cp[IPOPT_OFFSET + 1] += (1 << 4); 1677 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) { 1678 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1679 goto bad; 1680 } 1681 break; 1682 } 1683 off--; /* 0 origin */ 1684 sin = (struct in_addr *)(cp + off); 1685 switch (cp[IPOPT_OFFSET + 1] & 0x0f) { 1686 1687 case IPOPT_TS_TSONLY: 1688 break; 1689 1690 case IPOPT_TS_TSANDADDR: 1691 if (off + sizeof(n_time) + 1692 sizeof(struct in_addr) > optlen) { 1693 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1694 goto bad; 1695 } 1696 ipaddr.sin_addr = dst; 1697 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1698 m->m_pkthdr.rcvif); 1699 if (ia == NULL) 1700 continue; 1701 memcpy(sin, &IA_SIN(ia)->sin_addr, 1702 sizeof(struct in_addr)); 1703 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1704 off += sizeof(struct in_addr); 1705 break; 1706 1707 case IPOPT_TS_PRESPEC: 1708 if (off + sizeof(n_time) + 1709 sizeof(struct in_addr) > optlen) { 1710 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1711 goto bad; 1712 } 1713 memcpy(&ipaddr.sin_addr, sin, 1714 sizeof(struct in_addr)); 1715 if (ifa_ifwithaddr((SA)&ipaddr) == NULL) 1716 continue; 1717 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1718 off += sizeof(struct in_addr); 1719 break; 1720 1721 default: 1722 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip; 1723 goto bad; 1724 } 1725 ntime = iptime(); 1726 memcpy(cp + off, &ntime, sizeof(n_time)); 1727 cp[IPOPT_OFFSET] += sizeof(n_time); 1728 } 1729 } 1730 if (forward && ipforwarding) { 1731 ip_forward(m, TRUE, next_hop); 1732 return (1); 1733 } 1734 return (0); 1735 bad: 1736 icmp_error(m, type, code, 0, 0); 1737 ipstat.ips_badoptions++; 1738 return (1); 1739 } 1740 1741 /* 1742 * Given address of next destination (final or next hop), 1743 * return internet address info of interface to be used to get there. 1744 */ 1745 struct in_ifaddr * 1746 ip_rtaddr(struct in_addr dst, struct route *ro0) 1747 { 1748 struct route sro, *ro; 1749 struct sockaddr_in *sin; 1750 struct in_ifaddr *ia; 1751 1752 if (ro0 != NULL) { 1753 ro = ro0; 1754 } else { 1755 bzero(&sro, sizeof(sro)); 1756 ro = &sro; 1757 } 1758 1759 sin = (struct sockaddr_in *)&ro->ro_dst; 1760 1761 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) { 1762 if (ro->ro_rt != NULL) { 1763 RTFREE(ro->ro_rt); 1764 ro->ro_rt = NULL; 1765 } 1766 sin->sin_family = AF_INET; 1767 sin->sin_len = sizeof *sin; 1768 sin->sin_addr = dst; 1769 rtalloc_ign(ro, RTF_PRCLONING); 1770 } 1771 1772 if (ro->ro_rt == NULL) 1773 return (NULL); 1774 1775 ia = ifatoia(ro->ro_rt->rt_ifa); 1776 1777 if (ro == &sro) 1778 RTFREE(ro->ro_rt); 1779 return ia; 1780 } 1781 1782 /* 1783 * Save incoming source route for use in replies, 1784 * to be picked up later by ip_srcroute if the receiver is interested. 1785 */ 1786 static void 1787 save_rte(struct mbuf *m, u_char *option, struct in_addr dst) 1788 { 1789 struct m_tag *mtag; 1790 struct ip_srcrt_opt *opt; 1791 unsigned olen; 1792 1793 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), M_NOWAIT); 1794 if (mtag == NULL) 1795 return; 1796 opt = m_tag_data(mtag); 1797 1798 olen = option[IPOPT_OLEN]; 1799 #ifdef DIAGNOSTIC 1800 if (ipprintfs) 1801 kprintf("save_rte: olen %d\n", olen); 1802 #endif 1803 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) { 1804 m_tag_free(mtag); 1805 return; 1806 } 1807 bcopy(option, opt->ip_srcrt.srcopt, olen); 1808 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1809 opt->ip_srcrt.dst = dst; 1810 m_tag_prepend(m, mtag); 1811 } 1812 1813 /* 1814 * Retrieve incoming source route for use in replies, 1815 * in the same form used by setsockopt. 1816 * The first hop is placed before the options, will be removed later. 1817 */ 1818 struct mbuf * 1819 ip_srcroute(struct mbuf *m0) 1820 { 1821 struct in_addr *p, *q; 1822 struct mbuf *m; 1823 struct m_tag *mtag; 1824 struct ip_srcrt_opt *opt; 1825 1826 if (m0 == NULL) 1827 return NULL; 1828 1829 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL); 1830 if (mtag == NULL) 1831 return NULL; 1832 opt = m_tag_data(mtag); 1833 1834 if (opt->ip_nhops == 0) 1835 return (NULL); 1836 m = m_get(M_NOWAIT, MT_HEADER); 1837 if (m == NULL) 1838 return (NULL); 1839 1840 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt)) 1841 1842 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1843 m->m_len = opt->ip_nhops * sizeof(struct in_addr) + 1844 sizeof(struct in_addr) + OPTSIZ; 1845 #ifdef DIAGNOSTIC 1846 if (ipprintfs) { 1847 kprintf("ip_srcroute: nhops %d mlen %d", 1848 opt->ip_nhops, m->m_len); 1849 } 1850 #endif 1851 1852 /* 1853 * First save first hop for return route 1854 */ 1855 p = &opt->ip_srcrt.route[opt->ip_nhops - 1]; 1856 *(mtod(m, struct in_addr *)) = *p--; 1857 #ifdef DIAGNOSTIC 1858 if (ipprintfs) 1859 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1860 #endif 1861 1862 /* 1863 * Copy option fields and padding (nop) to mbuf. 1864 */ 1865 opt->ip_srcrt.nop = IPOPT_NOP; 1866 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1867 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop, 1868 OPTSIZ); 1869 q = (struct in_addr *)(mtod(m, caddr_t) + 1870 sizeof(struct in_addr) + OPTSIZ); 1871 #undef OPTSIZ 1872 /* 1873 * Record return path as an IP source route, 1874 * reversing the path (pointers are now aligned). 1875 */ 1876 while (p >= opt->ip_srcrt.route) { 1877 #ifdef DIAGNOSTIC 1878 if (ipprintfs) 1879 kprintf(" %x", ntohl(q->s_addr)); 1880 #endif 1881 *q++ = *p--; 1882 } 1883 /* 1884 * Last hop goes to final destination. 1885 */ 1886 *q = opt->ip_srcrt.dst; 1887 m_tag_delete(m0, mtag); 1888 #ifdef DIAGNOSTIC 1889 if (ipprintfs) 1890 kprintf(" %x\n", ntohl(q->s_addr)); 1891 #endif 1892 return (m); 1893 } 1894 1895 /* 1896 * Strip out IP options. 1897 */ 1898 void 1899 ip_stripoptions(struct mbuf *m) 1900 { 1901 int datalen; 1902 struct ip *ip = mtod(m, struct ip *); 1903 caddr_t opts; 1904 int optlen; 1905 1906 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1907 opts = (caddr_t)(ip + 1); 1908 datalen = m->m_len - (sizeof(struct ip) + optlen); 1909 bcopy(opts + optlen, opts, datalen); 1910 m->m_len -= optlen; 1911 if (m->m_flags & M_PKTHDR) 1912 m->m_pkthdr.len -= optlen; 1913 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2); 1914 } 1915 1916 u_char inetctlerrmap[PRC_NCMDS] = { 1917 0, 0, 0, 0, 1918 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1919 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1920 EMSGSIZE, EHOSTUNREACH, 0, 0, 1921 0, 0, 0, 0, 1922 ENOPROTOOPT, ECONNREFUSED 1923 }; 1924 1925 /* 1926 * Forward a packet. If some error occurs return the sender 1927 * an icmp packet. Note we can't always generate a meaningful 1928 * icmp message because icmp doesn't have a large enough repertoire 1929 * of codes and types. 1930 * 1931 * If not forwarding, just drop the packet. This could be confusing 1932 * if ipforwarding was zero but some routing protocol was advancing 1933 * us as a gateway to somewhere. However, we must let the routing 1934 * protocol deal with that. 1935 * 1936 * The using_srcrt parameter indicates whether the packet is being forwarded 1937 * via a source route. 1938 */ 1939 void 1940 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop) 1941 { 1942 struct ip *ip = mtod(m, struct ip *); 1943 struct rtentry *rt; 1944 struct route fwd_ro; 1945 int error, type = 0, code = 0, destmtu = 0; 1946 struct mbuf *mcopy, *mtemp = NULL; 1947 n_long dest; 1948 struct in_addr pkt_dst; 1949 1950 dest = INADDR_ANY; 1951 /* 1952 * Cache the destination address of the packet; this may be 1953 * changed by use of 'ipfw fwd'. 1954 */ 1955 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst; 1956 1957 #ifdef DIAGNOSTIC 1958 if (ipprintfs) 1959 kprintf("forward: src %x dst %x ttl %x\n", 1960 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl); 1961 #endif 1962 1963 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) { 1964 ipstat.ips_cantforward++; 1965 m_freem(m); 1966 return; 1967 } 1968 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) { 1969 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1970 return; 1971 } 1972 1973 bzero(&fwd_ro, sizeof(fwd_ro)); 1974 ip_rtaddr(pkt_dst, &fwd_ro); 1975 if (fwd_ro.ro_rt == NULL) { 1976 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1977 return; 1978 } 1979 rt = fwd_ro.ro_rt; 1980 1981 if (curthread->td_type == TD_TYPE_NETISR) { 1982 /* 1983 * Save the IP header and at most 8 bytes of the payload, 1984 * in case we need to generate an ICMP message to the src. 1985 */ 1986 mtemp = ipforward_mtemp[mycpuid]; 1987 KASSERT((mtemp->m_flags & M_EXT) == 0 && 1988 mtemp->m_data == mtemp->m_pktdat && 1989 m_tag_first(mtemp) == NULL, 1990 ("ip_forward invalid mtemp1")); 1991 1992 if (!m_dup_pkthdr(mtemp, m, M_NOWAIT)) { 1993 /* 1994 * It's probably ok if the pkthdr dup fails (because 1995 * the deep copy of the tag chain failed), but for now 1996 * be conservative and just discard the copy since 1997 * code below may some day want the tags. 1998 */ 1999 mtemp = NULL; 2000 } else { 2001 mtemp->m_type = m->m_type; 2002 mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8, 2003 (int)ip->ip_len); 2004 mtemp->m_pkthdr.len = mtemp->m_len; 2005 m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t)); 2006 } 2007 } 2008 2009 if (!ipstealth) 2010 ip->ip_ttl -= IPTTLDEC; 2011 2012 /* 2013 * If forwarding packet using same interface that it came in on, 2014 * perhaps should send a redirect to sender to shortcut a hop. 2015 * Only send redirect if source is sending directly to us, 2016 * and if packet was not source routed (or has any options). 2017 * Also, don't send redirect if forwarding using a default route 2018 * or a route modified by a redirect. 2019 */ 2020 if (rt->rt_ifp == m->m_pkthdr.rcvif && 2021 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) && 2022 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY && 2023 ipsendredirects && !using_srcrt && next_hop == NULL) { 2024 u_long src = ntohl(ip->ip_src.s_addr); 2025 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa; 2026 2027 if (rt_ifa != NULL && 2028 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) { 2029 if (rt->rt_flags & RTF_GATEWAY) 2030 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 2031 else 2032 dest = pkt_dst.s_addr; 2033 /* 2034 * Router requirements says to only send 2035 * host redirects. 2036 */ 2037 type = ICMP_REDIRECT; 2038 code = ICMP_REDIRECT_HOST; 2039 #ifdef DIAGNOSTIC 2040 if (ipprintfs) 2041 kprintf("redirect (%d) to %x\n", code, dest); 2042 #endif 2043 } 2044 } 2045 2046 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL); 2047 if (error == 0) { 2048 ipstat.ips_forward++; 2049 if (type == 0) { 2050 if (mtemp) 2051 ipflow_create(&fwd_ro, mtemp); 2052 goto done; 2053 } 2054 ipstat.ips_redirectsent++; 2055 } else { 2056 ipstat.ips_cantforward++; 2057 } 2058 2059 if (mtemp == NULL) 2060 goto done; 2061 2062 /* 2063 * Errors that do not require generating ICMP message 2064 */ 2065 switch (error) { 2066 case ENOBUFS: 2067 /* 2068 * A router should not generate ICMP_SOURCEQUENCH as 2069 * required in RFC1812 Requirements for IP Version 4 Routers. 2070 * Source quench could be a big problem under DoS attacks, 2071 * or if the underlying interface is rate-limited. 2072 * Those who need source quench packets may re-enable them 2073 * via the net.inet.ip.sendsourcequench sysctl. 2074 */ 2075 if (!ip_sendsourcequench) 2076 goto done; 2077 break; 2078 2079 case EACCES: /* ipfw denied packet */ 2080 goto done; 2081 } 2082 2083 KASSERT((mtemp->m_flags & M_EXT) == 0 && 2084 mtemp->m_data == mtemp->m_pktdat, 2085 ("ip_forward invalid mtemp2")); 2086 mcopy = m_copym(mtemp, 0, mtemp->m_len, M_NOWAIT); 2087 if (mcopy == NULL) 2088 goto done; 2089 2090 /* 2091 * Send ICMP message. 2092 */ 2093 switch (error) { 2094 case 0: /* forwarded, but need redirect */ 2095 /* type, code set above */ 2096 break; 2097 2098 case ENETUNREACH: /* shouldn't happen, checked above */ 2099 case EHOSTUNREACH: 2100 case ENETDOWN: 2101 case EHOSTDOWN: 2102 default: 2103 type = ICMP_UNREACH; 2104 code = ICMP_UNREACH_HOST; 2105 break; 2106 2107 case EMSGSIZE: 2108 type = ICMP_UNREACH; 2109 code = ICMP_UNREACH_NEEDFRAG; 2110 #ifdef IPSEC 2111 /* 2112 * If the packet is routed over IPsec tunnel, tell the 2113 * originator the tunnel MTU. 2114 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 2115 * XXX quickhack!!! 2116 */ 2117 if (fwd_ro.ro_rt != NULL) { 2118 struct secpolicy *sp = NULL; 2119 int ipsecerror; 2120 int ipsechdr; 2121 struct route *ro; 2122 2123 sp = ipsec4_getpolicybyaddr(mcopy, 2124 IPSEC_DIR_OUTBOUND, 2125 IP_FORWARDING, 2126 &ipsecerror); 2127 2128 if (sp == NULL) 2129 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2130 else { 2131 /* count IPsec header size */ 2132 ipsechdr = ipsec4_hdrsiz(mcopy, 2133 IPSEC_DIR_OUTBOUND, 2134 NULL); 2135 2136 /* 2137 * find the correct route for outer IPv4 2138 * header, compute tunnel MTU. 2139 * 2140 */ 2141 if (sp->req != NULL && sp->req->sav != NULL && 2142 sp->req->sav->sah != NULL) { 2143 ro = &sp->req->sav->sah->sa_route; 2144 if (ro->ro_rt != NULL && 2145 ro->ro_rt->rt_ifp != NULL) { 2146 destmtu = 2147 ro->ro_rt->rt_ifp->if_mtu; 2148 destmtu -= ipsechdr; 2149 } 2150 } 2151 2152 key_freesp(sp); 2153 } 2154 } 2155 #elif defined(FAST_IPSEC) 2156 /* 2157 * If the packet is routed over IPsec tunnel, tell the 2158 * originator the tunnel MTU. 2159 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 2160 * XXX quickhack!!! 2161 */ 2162 if (fwd_ro.ro_rt != NULL) { 2163 struct secpolicy *sp = NULL; 2164 int ipsecerror; 2165 int ipsechdr; 2166 struct route *ro; 2167 2168 sp = ipsec_getpolicybyaddr(mcopy, 2169 IPSEC_DIR_OUTBOUND, 2170 IP_FORWARDING, 2171 &ipsecerror); 2172 2173 if (sp == NULL) 2174 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2175 else { 2176 /* count IPsec header size */ 2177 ipsechdr = ipsec4_hdrsiz(mcopy, 2178 IPSEC_DIR_OUTBOUND, 2179 NULL); 2180 2181 /* 2182 * find the correct route for outer IPv4 2183 * header, compute tunnel MTU. 2184 */ 2185 2186 if (sp->req != NULL && 2187 sp->req->sav != NULL && 2188 sp->req->sav->sah != NULL) { 2189 ro = &sp->req->sav->sah->sa_route; 2190 if (ro->ro_rt != NULL && 2191 ro->ro_rt->rt_ifp != NULL) { 2192 destmtu = 2193 ro->ro_rt->rt_ifp->if_mtu; 2194 destmtu -= ipsechdr; 2195 } 2196 } 2197 2198 KEY_FREESP(&sp); 2199 } 2200 } 2201 #else /* !IPSEC && !FAST_IPSEC */ 2202 if (fwd_ro.ro_rt != NULL) 2203 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2204 #endif /*IPSEC*/ 2205 ipstat.ips_cantfrag++; 2206 break; 2207 2208 case ENOBUFS: 2209 type = ICMP_SOURCEQUENCH; 2210 code = 0; 2211 break; 2212 2213 case EACCES: /* ipfw denied packet */ 2214 panic("ip_forward EACCES should not reach"); 2215 } 2216 icmp_error(mcopy, type, code, dest, destmtu); 2217 done: 2218 if (mtemp != NULL) 2219 m_tag_delete_chain(mtemp); 2220 if (fwd_ro.ro_rt != NULL) 2221 RTFREE(fwd_ro.ro_rt); 2222 } 2223 2224 void 2225 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, 2226 struct mbuf *m) 2227 { 2228 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 2229 struct timeval tv; 2230 2231 microtime(&tv); 2232 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 2233 SCM_TIMESTAMP, SOL_SOCKET); 2234 if (*mp) 2235 mp = &(*mp)->m_next; 2236 } 2237 if (inp->inp_flags & INP_RECVDSTADDR) { 2238 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 2239 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 2240 if (*mp) 2241 mp = &(*mp)->m_next; 2242 } 2243 if (inp->inp_flags & INP_RECVTTL) { 2244 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, 2245 sizeof(u_char), IP_RECVTTL, IPPROTO_IP); 2246 if (*mp) 2247 mp = &(*mp)->m_next; 2248 } 2249 #ifdef notyet 2250 /* XXX 2251 * Moving these out of udp_input() made them even more broken 2252 * than they already were. 2253 */ 2254 /* options were tossed already */ 2255 if (inp->inp_flags & INP_RECVOPTS) { 2256 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 2257 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 2258 if (*mp) 2259 mp = &(*mp)->m_next; 2260 } 2261 /* ip_srcroute doesn't do what we want here, need to fix */ 2262 if (inp->inp_flags & INP_RECVRETOPTS) { 2263 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m), 2264 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 2265 if (*mp) 2266 mp = &(*mp)->m_next; 2267 } 2268 #endif 2269 if (inp->inp_flags & INP_RECVIF) { 2270 struct ifnet *ifp; 2271 struct sdlbuf { 2272 struct sockaddr_dl sdl; 2273 u_char pad[32]; 2274 } sdlbuf; 2275 struct sockaddr_dl *sdp; 2276 struct sockaddr_dl *sdl2 = &sdlbuf.sdl; 2277 2278 if (((ifp = m->m_pkthdr.rcvif)) && 2279 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) { 2280 sdp = IF_LLSOCKADDR(ifp); 2281 /* 2282 * Change our mind and don't try copy. 2283 */ 2284 if ((sdp->sdl_family != AF_LINK) || 2285 (sdp->sdl_len > sizeof(sdlbuf))) { 2286 goto makedummy; 2287 } 2288 bcopy(sdp, sdl2, sdp->sdl_len); 2289 } else { 2290 makedummy: 2291 sdl2->sdl_len = 2292 offsetof(struct sockaddr_dl, sdl_data[0]); 2293 sdl2->sdl_family = AF_LINK; 2294 sdl2->sdl_index = 0; 2295 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; 2296 } 2297 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len, 2298 IP_RECVIF, IPPROTO_IP); 2299 if (*mp) 2300 mp = &(*mp)->m_next; 2301 } 2302 } 2303 2304 /* 2305 * XXX these routines are called from the upper part of the kernel. 2306 * 2307 * They could also be moved to ip_mroute.c, since all the RSVP 2308 * handling is done there already. 2309 */ 2310 int 2311 ip_rsvp_init(struct socket *so) 2312 { 2313 if (so->so_type != SOCK_RAW || 2314 so->so_proto->pr_protocol != IPPROTO_RSVP) 2315 return EOPNOTSUPP; 2316 2317 if (ip_rsvpd != NULL) 2318 return EADDRINUSE; 2319 2320 ip_rsvpd = so; 2321 /* 2322 * This may seem silly, but we need to be sure we don't over-increment 2323 * the RSVP counter, in case something slips up. 2324 */ 2325 if (!ip_rsvp_on) { 2326 ip_rsvp_on = 1; 2327 rsvp_on++; 2328 } 2329 2330 return 0; 2331 } 2332 2333 int 2334 ip_rsvp_done(void) 2335 { 2336 ip_rsvpd = NULL; 2337 /* 2338 * This may seem silly, but we need to be sure we don't over-decrement 2339 * the RSVP counter, in case something slips up. 2340 */ 2341 if (ip_rsvp_on) { 2342 ip_rsvp_on = 0; 2343 rsvp_on--; 2344 } 2345 return 0; 2346 } 2347 2348 int 2349 rsvp_input(struct mbuf **mp, int *offp, int proto) 2350 { 2351 struct mbuf *m = *mp; 2352 2353 *mp = NULL; 2354 2355 if (rsvp_input_p) { /* call the real one if loaded */ 2356 *mp = m; 2357 rsvp_input_p(mp, offp, proto); 2358 return(IPPROTO_DONE); 2359 } 2360 2361 /* Can still get packets with rsvp_on = 0 if there is a local member 2362 * of the group to which the RSVP packet is addressed. But in this 2363 * case we want to throw the packet away. 2364 */ 2365 2366 if (!rsvp_on) { 2367 m_freem(m); 2368 return(IPPROTO_DONE); 2369 } 2370 2371 if (ip_rsvpd != NULL) { 2372 *mp = m; 2373 rip_input(mp, offp, proto); 2374 return(IPPROTO_DONE); 2375 } 2376 /* Drop the packet */ 2377 m_freem(m); 2378 return(IPPROTO_DONE); 2379 } 2380