ip_input.c revision 1.311
1/* $NetBSD: ip_input.c,v 1.311 2014/05/22 22:01:12 rmind Exp $ */ 2 3/* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32/*- 33 * Copyright (c) 1998 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Public Access Networks Corporation ("Panix"). It was developed under 38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62/* 63 * Copyright (c) 1982, 1986, 1988, 1993 64 * The Regents of the University of California. All rights reserved. 65 * 66 * Redistribution and use in source and binary forms, with or without 67 * modification, are permitted provided that the following conditions 68 * are met: 69 * 1. Redistributions of source code must retain the above copyright 70 * notice, this list of conditions and the following disclaimer. 71 * 2. Redistributions in binary form must reproduce the above copyright 72 * notice, this list of conditions and the following disclaimer in the 73 * documentation and/or other materials provided with the distribution. 74 * 3. Neither the name of the University nor the names of its contributors 75 * may be used to endorse or promote products derived from this software 76 * without specific prior written permission. 77 * 78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 88 * SUCH DAMAGE. 89 * 90 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 91 */ 92 93#include <sys/cdefs.h> 94__KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.311 2014/05/22 22:01:12 rmind Exp $"); 95 96#include "opt_inet.h" 97#include "opt_compat_netbsd.h" 98#include "opt_gateway.h" 99#include "opt_ipsec.h" 100#include "opt_mrouting.h" 101#include "opt_mbuftrace.h" 102#include "opt_inet_csum.h" 103 104#include <sys/param.h> 105#include <sys/systm.h> 106#include <sys/mbuf.h> 107#include <sys/domain.h> 108#include <sys/protosw.h> 109#include <sys/socket.h> 110#include <sys/socketvar.h> 111#include <sys/errno.h> 112#include <sys/time.h> 113#include <sys/kernel.h> 114#include <sys/pool.h> 115#include <sys/sysctl.h> 116#include <sys/kauth.h> 117 118#include <net/if.h> 119#include <net/if_dl.h> 120#include <net/route.h> 121#include <net/pfil.h> 122 123#include <netinet/in.h> 124#include <netinet/in_systm.h> 125#include <netinet/ip.h> 126#include <netinet/in_pcb.h> 127#include <netinet/in_proto.h> 128#include <netinet/in_var.h> 129#include <netinet/ip_var.h> 130#include <netinet/ip_private.h> 131#include <netinet/ip_icmp.h> 132/* just for gif_ttl */ 133#include <netinet/in_gif.h> 134#include "gif.h" 135#include <net/if_gre.h> 136#include "gre.h" 137 138#ifdef MROUTING 139#include <netinet/ip_mroute.h> 140#endif 141#include <netinet/portalgo.h> 142 143#ifdef IPSEC 144#include <netipsec/ipsec.h> 145#endif 146 147#ifndef IPFORWARDING 148#ifdef GATEWAY 149#define IPFORWARDING 1 /* forward IP packets not for us */ 150#else /* GATEWAY */ 151#define IPFORWARDING 0 /* don't forward IP packets not for us */ 152#endif /* GATEWAY */ 153#endif /* IPFORWARDING */ 154#ifndef IPSENDREDIRECTS 155#define IPSENDREDIRECTS 1 156#endif 157#ifndef IPFORWSRCRT 158#define IPFORWSRCRT 1 /* forward source-routed packets */ 159#endif 160#ifndef IPALLOWSRCRT 161#define IPALLOWSRCRT 1 /* allow source-routed packets */ 162#endif 163#ifndef IPMTUDISC 164#define IPMTUDISC 1 165#endif 166#ifndef IPMTUDISCTIMEOUT 167#define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */ 168#endif 169 170#ifdef COMPAT_50 171#include <compat/sys/time.h> 172#include <compat/sys/socket.h> 173#endif 174 175/* 176 * Note: DIRECTED_BROADCAST is handled this way so that previous 177 * configuration using this option will Just Work. 178 */ 179#ifndef IPDIRECTEDBCAST 180#ifdef DIRECTED_BROADCAST 181#define IPDIRECTEDBCAST 1 182#else 183#define IPDIRECTEDBCAST 0 184#endif /* DIRECTED_BROADCAST */ 185#endif /* IPDIRECTEDBCAST */ 186int ipforwarding = IPFORWARDING; 187int ipsendredirects = IPSENDREDIRECTS; 188int ip_defttl = IPDEFTTL; 189int ip_forwsrcrt = IPFORWSRCRT; 190int ip_directedbcast = IPDIRECTEDBCAST; 191int ip_allowsrcrt = IPALLOWSRCRT; 192int ip_mtudisc = IPMTUDISC; 193int ip_mtudisc_timeout = IPMTUDISCTIMEOUT; 194#ifdef DIAGNOSTIC 195int ipprintfs = 0; 196#endif 197 198int ip_do_randomid = 0; 199 200/* 201 * XXX - Setting ip_checkinterface mostly implements the receive side of 202 * the Strong ES model described in RFC 1122, but since the routing table 203 * and transmit implementation do not implement the Strong ES model, 204 * setting this to 1 results in an odd hybrid. 205 * 206 * XXX - ip_checkinterface currently must be disabled if you use ipnat 207 * to translate the destination address to another local interface. 208 * 209 * XXX - ip_checkinterface must be disabled if you add IP aliases 210 * to the loopback interface instead of the interface where the 211 * packets for those addresses are received. 212 */ 213int ip_checkinterface = 0; 214 215struct rttimer_queue *ip_mtudisc_timeout_q = NULL; 216 217struct ifqueue ipintrq; 218 219ipid_state_t * ip_ids; 220uint16_t ip_id; 221 222percpu_t *ipstat_percpu; 223 224pfil_head_t *inet_pfil_hook; 225 226#ifdef INET_CSUM_COUNTERS 227#include <sys/device.h> 228 229struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 230 NULL, "inet", "hwcsum bad"); 231struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 232 NULL, "inet", "hwcsum ok"); 233struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, 234 NULL, "inet", "swcsum"); 235 236#define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++ 237 238EVCNT_ATTACH_STATIC(ip_hwcsum_bad); 239EVCNT_ATTACH_STATIC(ip_hwcsum_ok); 240EVCNT_ATTACH_STATIC(ip_swcsum); 241 242#else 243 244#define INET_CSUM_COUNTER_INCR(ev) /* nothing */ 245 246#endif /* INET_CSUM_COUNTERS */ 247 248/* 249 * We need to save the IP options in case a protocol wants to respond 250 * to an incoming packet over the same route if the packet got here 251 * using IP source routing. This allows connection establishment and 252 * maintenance when the remote end is on a network that is not known 253 * to us. 254 */ 255 256static int ip_nhops = 0; 257 258static struct ip_srcrt { 259 struct in_addr dst; /* final destination */ 260 char nop; /* one NOP to align */ 261 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 262 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 263} ip_srcrt; 264 265static int ip_drainwanted; 266 267static void save_rte(u_char *, struct in_addr); 268 269#ifdef MBUFTRACE 270struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx"); 271struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx"); 272#endif 273 274static bool ip_dooptions(struct mbuf *); 275static struct in_ifaddr *ip_rtaddr(struct in_addr); 276static void sysctl_net_inet_ip_setup(struct sysctllog **); 277 278/* 279 * IP initialization: fill in IP protocol switch table. 280 * All protocols not implemented in kernel go to raw IP protocol handler. 281 */ 282void 283ip_init(void) 284{ 285 const struct protosw *pr; 286 287 in_init(); 288 sysctl_net_inet_ip_setup(NULL); 289 290 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 291 KASSERT(pr != NULL); 292 293 for (u_int i = 0; i < IPPROTO_MAX; i++) { 294 ip_protox[i] = pr - inetsw; 295 } 296 for (pr = inetdomain.dom_protosw; 297 pr < inetdomain.dom_protoswNPROTOSW; pr++) 298 if (pr->pr_domain->dom_family == PF_INET && 299 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 300 ip_protox[pr->pr_protocol] = pr - inetsw; 301 302 ip_reass_init(); 303 304 ip_ids = ip_id_init(); 305 ip_id = time_second & 0xfffff; 306 307 ipintrq.ifq_maxlen = IFQ_MAXLEN; 308 309 ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout); 310#ifdef GATEWAY 311 ipflow_init(); 312#endif 313 314 /* Register our Packet Filter hook. */ 315 inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET); 316 KASSERT(inet_pfil_hook != NULL); 317 318#ifdef MBUFTRACE 319 MOWNER_ATTACH(&ip_tx_mowner); 320 MOWNER_ATTACH(&ip_rx_mowner); 321#endif /* MBUFTRACE */ 322 323 ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS); 324} 325 326struct sockaddr_in ipaddr = { 327 .sin_len = sizeof(ipaddr), 328 .sin_family = AF_INET, 329}; 330 331static struct route ipforward_rt; 332 333/* 334 * IP software interrupt routine 335 */ 336void 337ipintr(void) 338{ 339 int s; 340 struct mbuf *m; 341 struct ifqueue lcl_intrq; 342 343 memset(&lcl_intrq, 0, sizeof(lcl_intrq)); 344 345 mutex_enter(softnet_lock); 346 KERNEL_LOCK(1, NULL); 347 if (!IF_IS_EMPTY(&ipintrq)) { 348 s = splnet(); 349 350 /* Take existing queue onto stack */ 351 lcl_intrq = ipintrq; 352 353 /* Zero out global queue, preserving maxlen and drops */ 354 ipintrq.ifq_head = NULL; 355 ipintrq.ifq_tail = NULL; 356 ipintrq.ifq_len = 0; 357 ipintrq.ifq_maxlen = lcl_intrq.ifq_maxlen; 358 ipintrq.ifq_drops = lcl_intrq.ifq_drops; 359 360 splx(s); 361 } 362 KERNEL_UNLOCK_ONE(NULL); 363 while (!IF_IS_EMPTY(&lcl_intrq)) { 364 IF_DEQUEUE(&lcl_intrq, m); 365 if (m == NULL) 366 break; 367 ip_input(m); 368 } 369 mutex_exit(softnet_lock); 370} 371 372/* 373 * Ip input routine. Checksum and byte swap header. If fragmented 374 * try to reassemble. Process options. Pass to next level. 375 */ 376void 377ip_input(struct mbuf *m) 378{ 379 struct ip *ip = NULL; 380 struct in_ifaddr *ia; 381 struct ifaddr *ifa; 382 int hlen = 0, len; 383 int downmatch; 384 int checkif; 385 int srcrt = 0; 386 387 MCLAIM(m, &ip_rx_mowner); 388 KASSERT((m->m_flags & M_PKTHDR) != 0); 389 390 /* 391 * If no IP addresses have been set yet but the interfaces 392 * are receiving, can't do anything with incoming packets yet. 393 */ 394 if (TAILQ_FIRST(&in_ifaddrhead) == 0) 395 goto bad; 396 IP_STATINC(IP_STAT_TOTAL); 397 /* 398 * If the IP header is not aligned, slurp it up into a new 399 * mbuf with space for link headers, in the event we forward 400 * it. Otherwise, if it is aligned, make sure the entire 401 * base IP header is in the first mbuf of the chain. 402 */ 403 if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) { 404 if ((m = m_copyup(m, sizeof(struct ip), 405 (max_linkhdr + 3) & ~3)) == NULL) { 406 /* XXXJRT new stat, please */ 407 IP_STATINC(IP_STAT_TOOSMALL); 408 return; 409 } 410 } else if (__predict_false(m->m_len < sizeof (struct ip))) { 411 if ((m = m_pullup(m, sizeof (struct ip))) == NULL) { 412 IP_STATINC(IP_STAT_TOOSMALL); 413 return; 414 } 415 } 416 ip = mtod(m, struct ip *); 417 if (ip->ip_v != IPVERSION) { 418 IP_STATINC(IP_STAT_BADVERS); 419 goto bad; 420 } 421 hlen = ip->ip_hl << 2; 422 if (hlen < sizeof(struct ip)) { /* minimum header length */ 423 IP_STATINC(IP_STAT_BADHLEN); 424 goto bad; 425 } 426 if (hlen > m->m_len) { 427 if ((m = m_pullup(m, hlen)) == NULL) { 428 IP_STATINC(IP_STAT_BADHLEN); 429 return; 430 } 431 ip = mtod(m, struct ip *); 432 } 433 434 /* 435 * RFC1122: packets with a multicast source address are 436 * not allowed. 437 */ 438 if (IN_MULTICAST(ip->ip_src.s_addr)) { 439 IP_STATINC(IP_STAT_BADADDR); 440 goto bad; 441 } 442 443 /* 127/8 must not appear on wire - RFC1122 */ 444 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 445 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 446 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 447 IP_STATINC(IP_STAT_BADADDR); 448 goto bad; 449 } 450 } 451 452 switch (m->m_pkthdr.csum_flags & 453 ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) | 454 M_CSUM_IPv4_BAD)) { 455 case M_CSUM_IPv4|M_CSUM_IPv4_BAD: 456 INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad); 457 goto badcsum; 458 459 case M_CSUM_IPv4: 460 /* Checksum was okay. */ 461 INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok); 462 break; 463 464 default: 465 /* 466 * Must compute it ourselves. Maybe skip checksum on 467 * loopback interfaces. 468 */ 469 if (__predict_true(!(m->m_pkthdr.rcvif->if_flags & 470 IFF_LOOPBACK) || ip_do_loopback_cksum)) { 471 INET_CSUM_COUNTER_INCR(&ip_swcsum); 472 if (in_cksum(m, hlen) != 0) 473 goto badcsum; 474 } 475 break; 476 } 477 478 /* Retrieve the packet length. */ 479 len = ntohs(ip->ip_len); 480 481 /* 482 * Check for additional length bogosity 483 */ 484 if (len < hlen) { 485 IP_STATINC(IP_STAT_BADLEN); 486 goto bad; 487 } 488 489 /* 490 * Check that the amount of data in the buffers 491 * is as at least much as the IP header would have us expect. 492 * Trim mbufs if longer than we expect. 493 * Drop packet if shorter than we expect. 494 */ 495 if (m->m_pkthdr.len < len) { 496 IP_STATINC(IP_STAT_TOOSHORT); 497 goto bad; 498 } 499 if (m->m_pkthdr.len > len) { 500 if (m->m_len == m->m_pkthdr.len) { 501 m->m_len = len; 502 m->m_pkthdr.len = len; 503 } else 504 m_adj(m, len - m->m_pkthdr.len); 505 } 506 507 /* 508 * Assume that we can create a fast-forward IP flow entry 509 * based on this packet. 510 */ 511 m->m_flags |= M_CANFASTFWD; 512 513 /* 514 * Run through list of hooks for input packets. If there are any 515 * filters which require that additional packets in the flow are 516 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 517 * Note that filters must _never_ set this flag, as another filter 518 * in the list may have previously cleared it. 519 */ 520 /* 521 * let ipfilter look at packet on the wire, 522 * not the decapsulated packet. 523 */ 524#if defined(IPSEC) 525 if (!ipsec_indone(m)) 526#else 527 if (1) 528#endif 529 { 530 struct in_addr odst; 531 532 odst = ip->ip_dst; 533 if (pfil_run_hooks(inet_pfil_hook, &m, m->m_pkthdr.rcvif, 534 PFIL_IN) != 0) 535 return; 536 if (m == NULL) 537 return; 538 ip = mtod(m, struct ip *); 539 hlen = ip->ip_hl << 2; 540 /* 541 * XXX The setting of "srcrt" here is to prevent ip_forward() 542 * from generating ICMP redirects for packets that have 543 * been redirected by a hook back out on to the same LAN that 544 * they came from and is not an indication that the packet 545 * is being inffluenced by source routing options. This 546 * allows things like 547 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp" 548 * where tlp0 is both on the 1.1.1.0/24 network and is the 549 * default route for hosts on 1.1.1.0/24. Of course this 550 * also requires a "map tlp0 ..." to complete the story. 551 * One might argue whether or not this kind of network config. 552 * should be supported in this manner... 553 */ 554 srcrt = (odst.s_addr != ip->ip_dst.s_addr); 555 } 556 557#ifdef ALTQ 558 /* XXX Temporary until ALTQ is changed to use a pfil hook */ 559 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) { 560 /* packet dropped by traffic conditioner */ 561 return; 562 } 563#endif 564 565 /* 566 * Process options and, if not destined for us, 567 * ship it on. ip_dooptions returns 1 when an 568 * error was detected (causing an icmp message 569 * to be sent and the original packet to be freed). 570 */ 571 ip_nhops = 0; /* for source routed packets */ 572 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 573 return; 574 575 /* 576 * Enable a consistency check between the destination address 577 * and the arrival interface for a unicast packet (the RFC 1122 578 * strong ES model) if IP forwarding is disabled and the packet 579 * is not locally generated. 580 * 581 * XXX - Checking also should be disabled if the destination 582 * address is ipnat'ed to a different interface. 583 * 584 * XXX - Checking is incompatible with IP aliases added 585 * to the loopback interface instead of the interface where 586 * the packets are received. 587 * 588 * XXX - We need to add a per ifaddr flag for this so that 589 * we get finer grain control. 590 */ 591 checkif = ip_checkinterface && (ipforwarding == 0) && 592 (m->m_pkthdr.rcvif != NULL) && 593 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0); 594 595 /* 596 * Check our list of addresses, to see if the packet is for us. 597 * 598 * Traditional 4.4BSD did not consult IFF_UP at all. 599 * The behavior here is to treat addresses on !IFF_UP interface 600 * as not mine. 601 */ 602 downmatch = 0; 603 LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) { 604 if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) { 605 if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif) 606 continue; 607 if ((ia->ia_ifp->if_flags & IFF_UP) != 0) 608 break; 609 else 610 downmatch++; 611 } 612 } 613 if (ia != NULL) 614 goto ours; 615 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 616 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 617 if (ifa->ifa_addr->sa_family != AF_INET) 618 continue; 619 ia = ifatoia(ifa); 620 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 621 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 622 /* 623 * Look for all-0's host part (old broadcast addr), 624 * either for subnet or net. 625 */ 626 ip->ip_dst.s_addr == ia->ia_subnet || 627 ip->ip_dst.s_addr == ia->ia_net) 628 goto ours; 629 /* 630 * An interface with IP address zero accepts 631 * all packets that arrive on that interface. 632 */ 633 if (in_nullhost(ia->ia_addr.sin_addr)) 634 goto ours; 635 } 636 } 637 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 638 struct in_multi *inm; 639#ifdef MROUTING 640 extern struct socket *ip_mrouter; 641 642 if (ip_mrouter) { 643 /* 644 * If we are acting as a multicast router, all 645 * incoming multicast packets are passed to the 646 * kernel-level multicast forwarding function. 647 * The packet is returned (relatively) intact; if 648 * ip_mforward() returns a non-zero value, the packet 649 * must be discarded, else it may be accepted below. 650 * 651 * (The IP ident field is put in the same byte order 652 * as expected when ip_mforward() is called from 653 * ip_output().) 654 */ 655 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 656 IP_STATINC(IP_STAT_CANTFORWARD); 657 m_freem(m); 658 return; 659 } 660 661 /* 662 * The process-level routing demon needs to receive 663 * all multicast IGMP packets, whether or not this 664 * host belongs to their destination groups. 665 */ 666 if (ip->ip_p == IPPROTO_IGMP) 667 goto ours; 668 IP_STATINC(IP_STAT_CANTFORWARD); 669 } 670#endif 671 /* 672 * See if we belong to the destination multicast group on the 673 * arrival interface. 674 */ 675 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 676 if (inm == NULL) { 677 IP_STATINC(IP_STAT_CANTFORWARD); 678 m_freem(m); 679 return; 680 } 681 goto ours; 682 } 683 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 684 in_nullhost(ip->ip_dst)) 685 goto ours; 686 687 /* 688 * Not for us; forward if possible and desirable. 689 */ 690 if (ipforwarding == 0) { 691 IP_STATINC(IP_STAT_CANTFORWARD); 692 m_freem(m); 693 } else { 694 /* 695 * If ip_dst matched any of my address on !IFF_UP interface, 696 * and there's no IFF_UP interface that matches ip_dst, 697 * send icmp unreach. Forwarding it will result in in-kernel 698 * forwarding loop till TTL goes to 0. 699 */ 700 if (downmatch) { 701 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0); 702 IP_STATINC(IP_STAT_CANTFORWARD); 703 return; 704 } 705#ifdef IPSEC 706 /* Perform IPsec, if any. */ 707 if (ipsec4_input(m, IP_FORWARDING | (ip_directedbcast ? 708 IP_ALLOWBROADCAST : 0)) != 0) { 709 goto bad; 710 } 711#endif 712 ip_forward(m, srcrt); 713 } 714 return; 715 716ours: 717 /* 718 * If offset or IP_MF are set, must reassemble. 719 */ 720 if (ip->ip_off & ~htons(IP_DF|IP_RF)) { 721 /* 722 * Pass to IP reassembly mechanism. 723 */ 724 if (ip_reass_packet(&m, ip) != 0) { 725 /* Failed; invalid fragment(s) or packet. */ 726 goto bad; 727 } 728 if (m == NULL) { 729 /* More fragments should come; silently return. */ 730 return; 731 } 732 /* 733 * Reassembly is done, we have the final packet. 734 * Updated cached data in local variable(s). 735 */ 736 ip = mtod(m, struct ip *); 737 hlen = ip->ip_hl << 2; 738 } 739 740#ifdef IPSEC 741 /* 742 * Enforce IPsec policy checking if we are seeing last header. 743 * Note that we do not visit this with protocols with PCB layer 744 * code - like UDP/TCP/raw IP. 745 */ 746 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) { 747 if (ipsec4_input(m, 0) != 0) { 748 goto bad; 749 } 750 } 751#endif 752 753 /* 754 * Switch out to protocol's input routine. 755 */ 756#if IFA_STATS 757 if (ia && ip) 758 ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len); 759#endif 760 IP_STATINC(IP_STAT_DELIVERED); 761 { 762 int off = hlen, nh = ip->ip_p; 763 764 (*inetsw[ip_protox[nh]].pr_input)(m, off, nh); 765 return; 766 } 767bad: 768 m_freem(m); 769 return; 770 771badcsum: 772 IP_STATINC(IP_STAT_BADSUM); 773 m_freem(m); 774} 775 776/* 777 * IP timer processing. 778 */ 779void 780ip_slowtimo(void) 781{ 782 783 mutex_enter(softnet_lock); 784 KERNEL_LOCK(1, NULL); 785 786 ip_reass_slowtimo(); 787 788 KERNEL_UNLOCK_ONE(NULL); 789 mutex_exit(softnet_lock); 790} 791 792/* 793 * IP drain processing. 794 */ 795void 796ip_drain(void) 797{ 798 799 KERNEL_LOCK(1, NULL); 800 ip_reass_drain(); 801 KERNEL_UNLOCK_ONE(NULL); 802} 803 804/* 805 * ip_dooptions: perform option processing on a datagram, possibly discarding 806 * it if bad options are encountered, or forwarding it if source-routed. 807 * 808 * => Returns true if packet has been forwarded/freed. 809 * => Returns false if the packet should be processed further. 810 */ 811static bool 812ip_dooptions(struct mbuf *m) 813{ 814 struct ip *ip = mtod(m, struct ip *); 815 u_char *cp, *cp0; 816 struct ip_timestamp *ipt; 817 struct in_ifaddr *ia; 818 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 819 struct in_addr dst; 820 n_time ntime; 821 822 dst = ip->ip_dst; 823 cp = (u_char *)(ip + 1); 824 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 825 for (; cnt > 0; cnt -= optlen, cp += optlen) { 826 opt = cp[IPOPT_OPTVAL]; 827 if (opt == IPOPT_EOL) 828 break; 829 if (opt == IPOPT_NOP) 830 optlen = 1; 831 else { 832 if (cnt < IPOPT_OLEN + sizeof(*cp)) { 833 code = &cp[IPOPT_OLEN] - (u_char *)ip; 834 goto bad; 835 } 836 optlen = cp[IPOPT_OLEN]; 837 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 838 code = &cp[IPOPT_OLEN] - (u_char *)ip; 839 goto bad; 840 } 841 } 842 switch (opt) { 843 844 default: 845 break; 846 847 /* 848 * Source routing with record. 849 * Find interface with current destination address. 850 * If none on this machine then drop if strictly routed, 851 * or do nothing if loosely routed. 852 * Record interface address and bring up next address 853 * component. If strictly routed make sure next 854 * address is on directly accessible net. 855 */ 856 case IPOPT_LSRR: 857 case IPOPT_SSRR: 858 if (ip_allowsrcrt == 0) { 859 type = ICMP_UNREACH; 860 code = ICMP_UNREACH_NET_PROHIB; 861 goto bad; 862 } 863 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 864 code = &cp[IPOPT_OLEN] - (u_char *)ip; 865 goto bad; 866 } 867 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 868 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 869 goto bad; 870 } 871 ipaddr.sin_addr = ip->ip_dst; 872 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 873 if (ia == 0) { 874 if (opt == IPOPT_SSRR) { 875 type = ICMP_UNREACH; 876 code = ICMP_UNREACH_SRCFAIL; 877 goto bad; 878 } 879 /* 880 * Loose routing, and not at next destination 881 * yet; nothing to do except forward. 882 */ 883 break; 884 } 885 off--; /* 0 origin */ 886 if ((off + sizeof(struct in_addr)) > optlen) { 887 /* 888 * End of source route. Should be for us. 889 */ 890 save_rte(cp, ip->ip_src); 891 break; 892 } 893 /* 894 * locate outgoing interface 895 */ 896 memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off), 897 sizeof(ipaddr.sin_addr)); 898 if (opt == IPOPT_SSRR) 899 ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr))); 900 else 901 ia = ip_rtaddr(ipaddr.sin_addr); 902 if (ia == 0) { 903 type = ICMP_UNREACH; 904 code = ICMP_UNREACH_SRCFAIL; 905 goto bad; 906 } 907 ip->ip_dst = ipaddr.sin_addr; 908 bcopy((void *)&ia->ia_addr.sin_addr, 909 (void *)(cp + off), sizeof(struct in_addr)); 910 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 911 /* 912 * Let ip_intr's mcast routing check handle mcast pkts 913 */ 914 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 915 break; 916 917 case IPOPT_RR: 918 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 919 code = &cp[IPOPT_OLEN] - (u_char *)ip; 920 goto bad; 921 } 922 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 923 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 924 goto bad; 925 } 926 /* 927 * If no space remains, ignore. 928 */ 929 off--; /* 0 origin */ 930 if ((off + sizeof(struct in_addr)) > optlen) 931 break; 932 memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst), 933 sizeof(ipaddr.sin_addr)); 934 /* 935 * locate outgoing interface; if we're the destination, 936 * use the incoming interface (should be same). 937 */ 938 if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))) 939 == NULL && 940 (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) { 941 type = ICMP_UNREACH; 942 code = ICMP_UNREACH_HOST; 943 goto bad; 944 } 945 bcopy((void *)&ia->ia_addr.sin_addr, 946 (void *)(cp + off), sizeof(struct in_addr)); 947 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 948 break; 949 950 case IPOPT_TS: 951 code = cp - (u_char *)ip; 952 ipt = (struct ip_timestamp *)cp; 953 if (ipt->ipt_len < 4 || ipt->ipt_len > 40) { 954 code = (u_char *)&ipt->ipt_len - (u_char *)ip; 955 goto bad; 956 } 957 if (ipt->ipt_ptr < 5) { 958 code = (u_char *)&ipt->ipt_ptr - (u_char *)ip; 959 goto bad; 960 } 961 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 962 if (++ipt->ipt_oflw == 0) { 963 code = (u_char *)&ipt->ipt_ptr - 964 (u_char *)ip; 965 goto bad; 966 } 967 break; 968 } 969 cp0 = (cp + ipt->ipt_ptr - 1); 970 switch (ipt->ipt_flg) { 971 972 case IPOPT_TS_TSONLY: 973 break; 974 975 case IPOPT_TS_TSANDADDR: 976 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 977 sizeof(struct in_addr) > ipt->ipt_len) { 978 code = (u_char *)&ipt->ipt_ptr - 979 (u_char *)ip; 980 goto bad; 981 } 982 ipaddr.sin_addr = dst; 983 ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr), 984 m->m_pkthdr.rcvif)); 985 if (ia == 0) 986 continue; 987 bcopy(&ia->ia_addr.sin_addr, 988 cp0, sizeof(struct in_addr)); 989 ipt->ipt_ptr += sizeof(struct in_addr); 990 break; 991 992 case IPOPT_TS_PRESPEC: 993 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 994 sizeof(struct in_addr) > ipt->ipt_len) { 995 code = (u_char *)&ipt->ipt_ptr - 996 (u_char *)ip; 997 goto bad; 998 } 999 memcpy(&ipaddr.sin_addr, cp0, 1000 sizeof(struct in_addr)); 1001 if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))) 1002 == NULL) 1003 continue; 1004 ipt->ipt_ptr += sizeof(struct in_addr); 1005 break; 1006 1007 default: 1008 /* XXX can't take &ipt->ipt_flg */ 1009 code = (u_char *)&ipt->ipt_ptr - 1010 (u_char *)ip + 1; 1011 goto bad; 1012 } 1013 ntime = iptime(); 1014 cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */ 1015 memmove((char *)cp + ipt->ipt_ptr - 1, cp0, 1016 sizeof(n_time)); 1017 ipt->ipt_ptr += sizeof(n_time); 1018 } 1019 } 1020 if (forward) { 1021 if (ip_forwsrcrt == 0) { 1022 type = ICMP_UNREACH; 1023 code = ICMP_UNREACH_SRCFAIL; 1024 goto bad; 1025 } 1026 ip_forward(m, 1); 1027 return true; 1028 } 1029 return false; 1030bad: 1031 icmp_error(m, type, code, 0, 0); 1032 IP_STATINC(IP_STAT_BADOPTIONS); 1033 return true; 1034} 1035 1036/* 1037 * ip_rtaddr: given address of next destination (final or next hop), 1038 * return internet address info of interface to be used to get there. 1039 */ 1040static struct in_ifaddr * 1041ip_rtaddr(struct in_addr dst) 1042{ 1043 struct rtentry *rt; 1044 union { 1045 struct sockaddr dst; 1046 struct sockaddr_in dst4; 1047 } u; 1048 1049 sockaddr_in_init(&u.dst4, &dst, 0); 1050 1051 if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) 1052 return NULL; 1053 1054 return ifatoia(rt->rt_ifa); 1055} 1056 1057/* 1058 * save_rte: save incoming source route for use in replies, to be picked 1059 * up later by ip_srcroute if the receiver is interested. 1060 */ 1061static void 1062save_rte(u_char *option, struct in_addr dst) 1063{ 1064 unsigned olen; 1065 1066 olen = option[IPOPT_OLEN]; 1067 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1068 return; 1069 memcpy((void *)ip_srcrt.srcopt, (void *)option, olen); 1070 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1071 ip_srcrt.dst = dst; 1072} 1073 1074/* 1075 * Retrieve incoming source route for use in replies, 1076 * in the same form used by setsockopt. 1077 * The first hop is placed before the options, will be removed later. 1078 */ 1079struct mbuf * 1080ip_srcroute(void) 1081{ 1082 struct in_addr *p, *q; 1083 struct mbuf *m; 1084 1085 if (ip_nhops == 0) 1086 return NULL; 1087 m = m_get(M_DONTWAIT, MT_SOOPTS); 1088 if (m == 0) 1089 return NULL; 1090 1091 MCLAIM(m, &inetdomain.dom_mowner); 1092#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1093 1094 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1095 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1096 OPTSIZ; 1097 1098 /* 1099 * First save first hop for return route 1100 */ 1101 p = &ip_srcrt.route[ip_nhops - 1]; 1102 *(mtod(m, struct in_addr *)) = *p--; 1103 1104 /* 1105 * Copy option fields and padding (nop) to mbuf. 1106 */ 1107 ip_srcrt.nop = IPOPT_NOP; 1108 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1109 memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop, 1110 OPTSIZ); 1111 q = (struct in_addr *)(mtod(m, char *) + 1112 sizeof(struct in_addr) + OPTSIZ); 1113#undef OPTSIZ 1114 /* 1115 * Record return path as an IP source route, 1116 * reversing the path (pointers are now aligned). 1117 */ 1118 while (p >= ip_srcrt.route) { 1119 *q++ = *p--; 1120 } 1121 /* 1122 * Last hop goes to final destination. 1123 */ 1124 *q = ip_srcrt.dst; 1125 return (m); 1126} 1127 1128const int inetctlerrmap[PRC_NCMDS] = { 1129 [PRC_MSGSIZE] = EMSGSIZE, 1130 [PRC_HOSTDEAD] = EHOSTDOWN, 1131 [PRC_HOSTUNREACH] = EHOSTUNREACH, 1132 [PRC_UNREACH_NET] = EHOSTUNREACH, 1133 [PRC_UNREACH_HOST] = EHOSTUNREACH, 1134 [PRC_UNREACH_PROTOCOL] = ECONNREFUSED, 1135 [PRC_UNREACH_PORT] = ECONNREFUSED, 1136 [PRC_UNREACH_SRCFAIL] = EHOSTUNREACH, 1137 [PRC_PARAMPROB] = ENOPROTOOPT, 1138}; 1139 1140void 1141ip_fasttimo(void) 1142{ 1143 if (ip_drainwanted) { 1144 ip_drain(); 1145 ip_drainwanted = 0; 1146 } 1147} 1148 1149void 1150ip_drainstub(void) 1151{ 1152 ip_drainwanted = 1; 1153} 1154 1155/* 1156 * Forward a packet. If some error occurs return the sender 1157 * an icmp packet. Note we can't always generate a meaningful 1158 * icmp message because icmp doesn't have a large enough repertoire 1159 * of codes and types. 1160 * 1161 * If not forwarding, just drop the packet. This could be confusing 1162 * if ipforwarding was zero but some routing protocol was advancing 1163 * us as a gateway to somewhere. However, we must let the routing 1164 * protocol deal with that. 1165 * 1166 * The srcrt parameter indicates whether the packet is being forwarded 1167 * via a source route. 1168 */ 1169void 1170ip_forward(struct mbuf *m, int srcrt) 1171{ 1172 struct ip *ip = mtod(m, struct ip *); 1173 struct rtentry *rt; 1174 int error, type = 0, code = 0, destmtu = 0; 1175 struct mbuf *mcopy; 1176 n_long dest; 1177 union { 1178 struct sockaddr dst; 1179 struct sockaddr_in dst4; 1180 } u; 1181 1182 /* 1183 * We are now in the output path. 1184 */ 1185 MCLAIM(m, &ip_tx_mowner); 1186 1187 /* 1188 * Clear any in-bound checksum flags for this packet. 1189 */ 1190 m->m_pkthdr.csum_flags = 0; 1191 1192 dest = 0; 1193 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { 1194 IP_STATINC(IP_STAT_CANTFORWARD); 1195 m_freem(m); 1196 return; 1197 } 1198 if (ip->ip_ttl <= IPTTLDEC) { 1199 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1200 return; 1201 } 1202 1203 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 1204 if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) { 1205 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0); 1206 return; 1207 } 1208 1209 /* 1210 * Save at most 68 bytes of the packet in case 1211 * we need to generate an ICMP message to the src. 1212 * Pullup to avoid sharing mbuf cluster between m and mcopy. 1213 */ 1214 mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT); 1215 if (mcopy) 1216 mcopy = m_pullup(mcopy, ip->ip_hl << 2); 1217 1218 ip->ip_ttl -= IPTTLDEC; 1219 1220 /* 1221 * If forwarding packet using same interface that it came in on, 1222 * perhaps should send a redirect to sender to shortcut a hop. 1223 * Only send redirect if source is sending directly to us, 1224 * and if packet was not source routed (or has any options). 1225 * Also, don't send redirect if forwarding using a default route 1226 * or a route modified by a redirect. 1227 */ 1228 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1229 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1230 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) && 1231 ipsendredirects && !srcrt) { 1232 if (rt->rt_ifa && 1233 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1234 ifatoia(rt->rt_ifa)->ia_subnet) { 1235 if (rt->rt_flags & RTF_GATEWAY) 1236 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1237 else 1238 dest = ip->ip_dst.s_addr; 1239 /* 1240 * Router requirements says to only send host 1241 * redirects. 1242 */ 1243 type = ICMP_REDIRECT; 1244 code = ICMP_REDIRECT_HOST; 1245 } 1246 } 1247 1248 error = ip_output(m, NULL, &ipforward_rt, 1249 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 1250 NULL, NULL); 1251 1252 if (error) 1253 IP_STATINC(IP_STAT_CANTFORWARD); 1254 else { 1255 uint64_t *ips = IP_STAT_GETREF(); 1256 ips[IP_STAT_FORWARD]++; 1257 if (type) { 1258 ips[IP_STAT_REDIRECTSENT]++; 1259 IP_STAT_PUTREF(); 1260 } else { 1261 IP_STAT_PUTREF(); 1262 if (mcopy) { 1263#ifdef GATEWAY 1264 if (mcopy->m_flags & M_CANFASTFWD) 1265 ipflow_create(&ipforward_rt, mcopy); 1266#endif 1267 m_freem(mcopy); 1268 } 1269 return; 1270 } 1271 } 1272 if (mcopy == NULL) 1273 return; 1274 1275 switch (error) { 1276 1277 case 0: /* forwarded, but need redirect */ 1278 /* type, code set above */ 1279 break; 1280 1281 case ENETUNREACH: /* shouldn't happen, checked above */ 1282 case EHOSTUNREACH: 1283 case ENETDOWN: 1284 case EHOSTDOWN: 1285 default: 1286 type = ICMP_UNREACH; 1287 code = ICMP_UNREACH_HOST; 1288 break; 1289 1290 case EMSGSIZE: 1291 type = ICMP_UNREACH; 1292 code = ICMP_UNREACH_NEEDFRAG; 1293 1294 if ((rt = rtcache_validate(&ipforward_rt)) != NULL) 1295 destmtu = rt->rt_ifp->if_mtu; 1296#ifdef IPSEC 1297 (void)ipsec4_forward(mcopy, &destmtu); 1298#endif 1299 IP_STATINC(IP_STAT_CANTFRAG); 1300 break; 1301 1302 case ENOBUFS: 1303 /* 1304 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812, 1305 * Requirements for IP Version 4 Routers. Source quench can 1306 * big problem under DoS attacks or if the underlying 1307 * interface is rate-limited. 1308 */ 1309 if (mcopy) 1310 m_freem(mcopy); 1311 return; 1312 } 1313 icmp_error(mcopy, type, code, dest, destmtu); 1314} 1315 1316void 1317ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, 1318 struct mbuf *m) 1319{ 1320 struct socket *so = inp->inp_socket; 1321 int inpflags = inp->inp_flags; 1322 1323 if (so->so_options & SO_TIMESTAMP 1324#ifdef SO_OTIMESTAMP 1325 || so->so_options & SO_OTIMESTAMP 1326#endif 1327 ) { 1328 struct timeval tv; 1329 1330 microtime(&tv); 1331#ifdef SO_OTIMESTAMP 1332 if (so->so_options & SO_OTIMESTAMP) { 1333 struct timeval50 tv50; 1334 timeval_to_timeval50(&tv, &tv50); 1335 *mp = sbcreatecontrol((void *) &tv50, sizeof(tv50), 1336 SCM_OTIMESTAMP, SOL_SOCKET); 1337 } else 1338#endif 1339 *mp = sbcreatecontrol((void *) &tv, sizeof(tv), 1340 SCM_TIMESTAMP, SOL_SOCKET); 1341 if (*mp) 1342 mp = &(*mp)->m_next; 1343 } 1344 if (inpflags & INP_RECVDSTADDR) { 1345 *mp = sbcreatecontrol((void *) &ip->ip_dst, 1346 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1347 if (*mp) 1348 mp = &(*mp)->m_next; 1349 } 1350 if (inpflags & INP_RECVPKTINFO) { 1351 struct in_pktinfo ipi; 1352 ipi.ipi_addr = ip->ip_src; 1353 ipi.ipi_ifindex = m->m_pkthdr.rcvif->if_index; 1354 *mp = sbcreatecontrol((void *) &ipi, 1355 sizeof(ipi), IP_RECVPKTINFO, IPPROTO_IP); 1356 if (*mp) 1357 mp = &(*mp)->m_next; 1358 } 1359 if (inpflags & INP_PKTINFO) { 1360 struct in_pktinfo ipi; 1361 ipi.ipi_addr = ip->ip_dst; 1362 ipi.ipi_ifindex = m->m_pkthdr.rcvif->if_index; 1363 *mp = sbcreatecontrol((void *) &ipi, 1364 sizeof(ipi), IP_PKTINFO, IPPROTO_IP); 1365 if (*mp) 1366 mp = &(*mp)->m_next; 1367 } 1368 if (inpflags & INP_RECVIF) { 1369 struct sockaddr_dl sdl; 1370 1371 sockaddr_dl_init(&sdl, sizeof(sdl), m->m_pkthdr.rcvif ? 1372 m->m_pkthdr.rcvif->if_index : 0, 0, NULL, 0, NULL, 0); 1373 *mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP); 1374 if (*mp) 1375 mp = &(*mp)->m_next; 1376 } 1377 if (inpflags & INP_RECVTTL) { 1378 *mp = sbcreatecontrol((void *) &ip->ip_ttl, 1379 sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP); 1380 if (*mp) 1381 mp = &(*mp)->m_next; 1382 } 1383} 1384 1385/* 1386 * sysctl helper routine for net.inet.ip.forwsrcrt. 1387 */ 1388static int 1389sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS) 1390{ 1391 int error, tmp; 1392 struct sysctlnode node; 1393 1394 node = *rnode; 1395 tmp = ip_forwsrcrt; 1396 node.sysctl_data = &tmp; 1397 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1398 if (error || newp == NULL) 1399 return (error); 1400 1401 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT, 1402 0, NULL, NULL, NULL); 1403 if (error) 1404 return (error); 1405 1406 ip_forwsrcrt = tmp; 1407 1408 return (0); 1409} 1410 1411/* 1412 * sysctl helper routine for net.inet.ip.mtudisctimeout. checks the 1413 * range of the new value and tweaks timers if it changes. 1414 */ 1415static int 1416sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS) 1417{ 1418 int error, tmp; 1419 struct sysctlnode node; 1420 1421 node = *rnode; 1422 tmp = ip_mtudisc_timeout; 1423 node.sysctl_data = &tmp; 1424 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1425 if (error || newp == NULL) 1426 return (error); 1427 if (tmp < 0) 1428 return (EINVAL); 1429 1430 mutex_enter(softnet_lock); 1431 1432 ip_mtudisc_timeout = tmp; 1433 rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout); 1434 1435 mutex_exit(softnet_lock); 1436 1437 return (0); 1438} 1439 1440static int 1441sysctl_net_inet_ip_stats(SYSCTLFN_ARGS) 1442{ 1443 1444 return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS)); 1445} 1446 1447static void 1448sysctl_net_inet_ip_setup(struct sysctllog **clog) 1449{ 1450 sysctl_createv(clog, 0, NULL, NULL, 1451 CTLFLAG_PERMANENT, 1452 CTLTYPE_NODE, "inet", 1453 SYSCTL_DESCR("PF_INET related settings"), 1454 NULL, 0, NULL, 0, 1455 CTL_NET, PF_INET, CTL_EOL); 1456 sysctl_createv(clog, 0, NULL, NULL, 1457 CTLFLAG_PERMANENT, 1458 CTLTYPE_NODE, "ip", 1459 SYSCTL_DESCR("IPv4 related settings"), 1460 NULL, 0, NULL, 0, 1461 CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL); 1462 1463 sysctl_createv(clog, 0, NULL, NULL, 1464 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1465 CTLTYPE_INT, "forwarding", 1466 SYSCTL_DESCR("Enable forwarding of INET datagrams"), 1467 NULL, 0, &ipforwarding, 0, 1468 CTL_NET, PF_INET, IPPROTO_IP, 1469 IPCTL_FORWARDING, CTL_EOL); 1470 sysctl_createv(clog, 0, NULL, NULL, 1471 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1472 CTLTYPE_INT, "redirect", 1473 SYSCTL_DESCR("Enable sending of ICMP redirect messages"), 1474 NULL, 0, &ipsendredirects, 0, 1475 CTL_NET, PF_INET, IPPROTO_IP, 1476 IPCTL_SENDREDIRECTS, CTL_EOL); 1477 sysctl_createv(clog, 0, NULL, NULL, 1478 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1479 CTLTYPE_INT, "ttl", 1480 SYSCTL_DESCR("Default TTL for an INET datagram"), 1481 NULL, 0, &ip_defttl, 0, 1482 CTL_NET, PF_INET, IPPROTO_IP, 1483 IPCTL_DEFTTL, CTL_EOL); 1484#ifdef IPCTL_DEFMTU 1485 sysctl_createv(clog, 0, NULL, NULL, 1486 CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */, 1487 CTLTYPE_INT, "mtu", 1488 SYSCTL_DESCR("Default MTA for an INET route"), 1489 NULL, 0, &ip_mtu, 0, 1490 CTL_NET, PF_INET, IPPROTO_IP, 1491 IPCTL_DEFMTU, CTL_EOL); 1492#endif /* IPCTL_DEFMTU */ 1493 sysctl_createv(clog, 0, NULL, NULL, 1494 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1495 CTLTYPE_INT, "forwsrcrt", 1496 SYSCTL_DESCR("Enable forwarding of source-routed " 1497 "datagrams"), 1498 sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0, 1499 CTL_NET, PF_INET, IPPROTO_IP, 1500 IPCTL_FORWSRCRT, CTL_EOL); 1501 sysctl_createv(clog, 0, NULL, NULL, 1502 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1503 CTLTYPE_INT, "directed-broadcast", 1504 SYSCTL_DESCR("Enable forwarding of broadcast datagrams"), 1505 NULL, 0, &ip_directedbcast, 0, 1506 CTL_NET, PF_INET, IPPROTO_IP, 1507 IPCTL_DIRECTEDBCAST, CTL_EOL); 1508 sysctl_createv(clog, 0, NULL, NULL, 1509 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1510 CTLTYPE_INT, "allowsrcrt", 1511 SYSCTL_DESCR("Accept source-routed datagrams"), 1512 NULL, 0, &ip_allowsrcrt, 0, 1513 CTL_NET, PF_INET, IPPROTO_IP, 1514 IPCTL_ALLOWSRCRT, CTL_EOL); 1515 1516 sysctl_createv(clog, 0, NULL, NULL, 1517 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1518 CTLTYPE_INT, "mtudisc", 1519 SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"), 1520 NULL, 0, &ip_mtudisc, 0, 1521 CTL_NET, PF_INET, IPPROTO_IP, 1522 IPCTL_MTUDISC, CTL_EOL); 1523 sysctl_createv(clog, 0, NULL, NULL, 1524 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1525 CTLTYPE_INT, "anonportmin", 1526 SYSCTL_DESCR("Lowest ephemeral port number to assign"), 1527 sysctl_net_inet_ip_ports, 0, &anonportmin, 0, 1528 CTL_NET, PF_INET, IPPROTO_IP, 1529 IPCTL_ANONPORTMIN, CTL_EOL); 1530 sysctl_createv(clog, 0, NULL, NULL, 1531 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1532 CTLTYPE_INT, "anonportmax", 1533 SYSCTL_DESCR("Highest ephemeral port number to assign"), 1534 sysctl_net_inet_ip_ports, 0, &anonportmax, 0, 1535 CTL_NET, PF_INET, IPPROTO_IP, 1536 IPCTL_ANONPORTMAX, CTL_EOL); 1537 sysctl_createv(clog, 0, NULL, NULL, 1538 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1539 CTLTYPE_INT, "mtudisctimeout", 1540 SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"), 1541 sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0, 1542 CTL_NET, PF_INET, IPPROTO_IP, 1543 IPCTL_MTUDISCTIMEOUT, CTL_EOL); 1544#if NGIF > 0 1545 sysctl_createv(clog, 0, NULL, NULL, 1546 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1547 CTLTYPE_INT, "gifttl", 1548 SYSCTL_DESCR("Default TTL for a gif tunnel datagram"), 1549 NULL, 0, &ip_gif_ttl, 0, 1550 CTL_NET, PF_INET, IPPROTO_IP, 1551 IPCTL_GIF_TTL, CTL_EOL); 1552#endif /* NGIF */ 1553#ifndef IPNOPRIVPORTS 1554 sysctl_createv(clog, 0, NULL, NULL, 1555 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1556 CTLTYPE_INT, "lowportmin", 1557 SYSCTL_DESCR("Lowest privileged ephemeral port number " 1558 "to assign"), 1559 sysctl_net_inet_ip_ports, 0, &lowportmin, 0, 1560 CTL_NET, PF_INET, IPPROTO_IP, 1561 IPCTL_LOWPORTMIN, CTL_EOL); 1562 sysctl_createv(clog, 0, NULL, NULL, 1563 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1564 CTLTYPE_INT, "lowportmax", 1565 SYSCTL_DESCR("Highest privileged ephemeral port number " 1566 "to assign"), 1567 sysctl_net_inet_ip_ports, 0, &lowportmax, 0, 1568 CTL_NET, PF_INET, IPPROTO_IP, 1569 IPCTL_LOWPORTMAX, CTL_EOL); 1570#endif /* IPNOPRIVPORTS */ 1571#if NGRE > 0 1572 sysctl_createv(clog, 0, NULL, NULL, 1573 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1574 CTLTYPE_INT, "grettl", 1575 SYSCTL_DESCR("Default TTL for a gre tunnel datagram"), 1576 NULL, 0, &ip_gre_ttl, 0, 1577 CTL_NET, PF_INET, IPPROTO_IP, 1578 IPCTL_GRE_TTL, CTL_EOL); 1579#endif /* NGRE */ 1580 sysctl_createv(clog, 0, NULL, NULL, 1581 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1582 CTLTYPE_INT, "checkinterface", 1583 SYSCTL_DESCR("Enable receive side of Strong ES model " 1584 "from RFC1122"), 1585 NULL, 0, &ip_checkinterface, 0, 1586 CTL_NET, PF_INET, IPPROTO_IP, 1587 IPCTL_CHECKINTERFACE, CTL_EOL); 1588 sysctl_createv(clog, 0, NULL, NULL, 1589 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1590 CTLTYPE_INT, "random_id", 1591 SYSCTL_DESCR("Assign random ip_id values"), 1592 NULL, 0, &ip_do_randomid, 0, 1593 CTL_NET, PF_INET, IPPROTO_IP, 1594 IPCTL_RANDOMID, CTL_EOL); 1595 sysctl_createv(clog, 0, NULL, NULL, 1596 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1597 CTLTYPE_INT, "do_loopback_cksum", 1598 SYSCTL_DESCR("Perform IP checksum on loopback"), 1599 NULL, 0, &ip_do_loopback_cksum, 0, 1600 CTL_NET, PF_INET, IPPROTO_IP, 1601 IPCTL_LOOPBACKCKSUM, CTL_EOL); 1602 sysctl_createv(clog, 0, NULL, NULL, 1603 CTLFLAG_PERMANENT, 1604 CTLTYPE_STRUCT, "stats", 1605 SYSCTL_DESCR("IP statistics"), 1606 sysctl_net_inet_ip_stats, 0, NULL, 0, 1607 CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS, 1608 CTL_EOL); 1609 1610 /* anonportalgo RFC6056 subtree */ 1611 const struct sysctlnode *portalgo_node; 1612 sysctl_createv(clog, 0, NULL, &portalgo_node, 1613 CTLFLAG_PERMANENT, 1614 CTLTYPE_NODE, "anonportalgo", 1615 SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"), 1616 NULL, 0, NULL, 0, 1617 CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL); 1618 sysctl_createv(clog, 0, &portalgo_node, NULL, 1619 CTLFLAG_PERMANENT, 1620 CTLTYPE_STRING, "available", 1621 SYSCTL_DESCR("available algorithms"), 1622 sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN, 1623 CTL_CREATE, CTL_EOL); 1624 sysctl_createv(clog, 0, &portalgo_node, NULL, 1625 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1626 CTLTYPE_STRING, "selected", 1627 SYSCTL_DESCR("selected algorithm"), 1628 sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN, 1629 CTL_CREATE, CTL_EOL); 1630 sysctl_createv(clog, 0, &portalgo_node, NULL, 1631 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1632 CTLTYPE_STRUCT, "reserve", 1633 SYSCTL_DESCR("bitmap of reserved ports"), 1634 sysctl_portalgo_reserve4, 0, NULL, 0, 1635 CTL_CREATE, CTL_EOL); 1636} 1637 1638void 1639ip_statinc(u_int stat) 1640{ 1641 1642 KASSERT(stat < IP_NSTATS); 1643 IP_STATINC(stat); 1644} 1645