ip_reass.c revision 272199
1/*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: head/sys/netinet/ip_input.c 272199 2014-09-27 05:14:02Z adrian $"); 34 35#include "opt_bootp.h" 36#include "opt_ipfw.h" 37#include "opt_ipstealth.h" 38#include "opt_ipsec.h" 39#include "opt_route.h" 40#include "opt_rss.h" 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/mbuf.h> 45#include <sys/malloc.h> 46#include <sys/domain.h> 47#include <sys/protosw.h> 48#include <sys/socket.h> 49#include <sys/time.h> 50#include <sys/kernel.h> 51#include <sys/lock.h> 52#include <sys/rwlock.h> 53#include <sys/sdt.h> 54#include <sys/syslog.h> 55#include <sys/sysctl.h> 56 57#include <net/pfil.h> 58#include <net/if.h> 59#include <net/if_types.h> 60#include <net/if_var.h> 61#include <net/if_dl.h> 62#include <net/route.h> 63#include <net/netisr.h> 64#include <net/vnet.h> 65 66#include <netinet/in.h> 67#include <netinet/in_kdtrace.h> 68#include <netinet/in_systm.h> 69#include <netinet/in_var.h> 70#include <netinet/ip.h> 71#include <netinet/in_pcb.h> 72#include <netinet/ip_var.h> 73#include <netinet/ip_fw.h> 74#include <netinet/ip_icmp.h> 75#include <netinet/ip_options.h> 76#include <machine/in_cksum.h> 77#include <netinet/ip_carp.h> 78#ifdef IPSEC 79#include <netinet/ip_ipsec.h> 80#endif /* IPSEC */ 81#include <netinet/in_rss.h> 82 83#include <sys/socketvar.h> 84 85#include <security/mac/mac_framework.h> 86 87#ifdef CTASSERT 88CTASSERT(sizeof(struct ip) == 20); 89#endif 90 91struct rwlock in_ifaddr_lock; 92RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock"); 93 94VNET_DEFINE(int, rsvp_on); 95 96VNET_DEFINE(int, ipforwarding); 97SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, 98 &VNET_NAME(ipforwarding), 0, 99 "Enable IP forwarding between interfaces"); 100 101static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */ 102#define V_ipsendredirects VNET(ipsendredirects) 103SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, 104 &VNET_NAME(ipsendredirects), 0, 105 "Enable sending IP redirects"); 106 107static VNET_DEFINE(int, ip_keepfaith); 108#define V_ip_keepfaith VNET(ip_keepfaith) 109SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW, 110 &VNET_NAME(ip_keepfaith), 0, 111 "Enable packet capture for FAITH IPv4->IPv6 translater daemon"); 112 113static VNET_DEFINE(int, ip_sendsourcequench); 114#define V_ip_sendsourcequench VNET(ip_sendsourcequench) 115SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, 116 &VNET_NAME(ip_sendsourcequench), 0, 117 "Enable the transmission of source quench packets"); 118 119VNET_DEFINE(int, ip_do_randomid); 120SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, 121 &VNET_NAME(ip_do_randomid), 0, 122 "Assign random ip_id values"); 123 124/* 125 * XXX - Setting ip_checkinterface mostly implements the receive side of 126 * the Strong ES model described in RFC 1122, but since the routing table 127 * and transmit implementation do not implement the Strong ES model, 128 * setting this to 1 results in an odd hybrid. 129 * 130 * XXX - ip_checkinterface currently must be disabled if you use ipnat 131 * to translate the destination address to another local interface. 132 * 133 * XXX - ip_checkinterface must be disabled if you add IP aliases 134 * to the loopback interface instead of the interface where the 135 * packets for those addresses are received. 136 */ 137static VNET_DEFINE(int, ip_checkinterface); 138#define V_ip_checkinterface VNET(ip_checkinterface) 139SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, 140 &VNET_NAME(ip_checkinterface), 0, 141 "Verify packet arrives on correct interface"); 142 143VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */ 144 145static struct netisr_handler ip_nh = { 146 .nh_name = "ip", 147 .nh_handler = ip_input, 148 .nh_proto = NETISR_IP, 149#ifdef RSS 150 .nh_m2cpuid = rss_soft_m2cpuid, 151 .nh_policy = NETISR_POLICY_CPU, 152 .nh_dispatch = NETISR_DISPATCH_HYBRID, 153#else 154 .nh_policy = NETISR_POLICY_FLOW, 155#endif 156}; 157 158#ifdef RSS 159/* 160 * Directly dispatched frames are currently assumed 161 * to have a flowid already calculated. 162 * 163 * It should likely have something that assert it 164 * actually has valid flow details. 165 */ 166static struct netisr_handler ip_direct_nh = { 167 .nh_name = "ip_direct", 168 .nh_handler = ip_direct_input, 169 .nh_proto = NETISR_IP_DIRECT, 170 .nh_m2cpuid = rss_m2cpuid, 171 .nh_policy = NETISR_POLICY_CPU, 172 .nh_dispatch = NETISR_DISPATCH_HYBRID, 173}; 174#endif 175 176extern struct domain inetdomain; 177extern struct protosw inetsw[]; 178u_char ip_protox[IPPROTO_MAX]; 179VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */ 180VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */ 181VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */ 182 183static VNET_DEFINE(uma_zone_t, ipq_zone); 184static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]); 185static struct mtx ipqlock; 186 187#define V_ipq_zone VNET(ipq_zone) 188#define V_ipq VNET(ipq) 189 190#define IPQ_LOCK() mtx_lock(&ipqlock) 191#define IPQ_UNLOCK() mtx_unlock(&ipqlock) 192#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF) 193#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED) 194 195static void maxnipq_update(void); 196static void ipq_zone_change(void *); 197static void ip_drain_locked(void); 198 199static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */ 200static VNET_DEFINE(int, nipq); /* Total # of reass queues */ 201#define V_maxnipq VNET(maxnipq) 202#define V_nipq VNET(nipq) 203SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD, 204 &VNET_NAME(nipq), 0, 205 "Current number of IPv4 fragment reassembly queue entries"); 206 207static VNET_DEFINE(int, maxfragsperpacket); 208#define V_maxfragsperpacket VNET(maxfragsperpacket) 209SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, 210 &VNET_NAME(maxfragsperpacket), 0, 211 "Maximum number of IPv4 fragments allowed per packet"); 212 213#ifdef IPCTL_DEFMTU 214SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, 215 &ip_mtu, 0, "Default MTU"); 216#endif 217 218#ifdef IPSTEALTH 219VNET_DEFINE(int, ipstealth); 220SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, 221 &VNET_NAME(ipstealth), 0, 222 "IP stealth mode, no TTL decrementation on forwarding"); 223#endif 224 225static void ip_freef(struct ipqhead *, struct ipq *); 226 227/* 228 * IP statistics are stored in the "array" of counter(9)s. 229 */ 230VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat); 231VNET_PCPUSTAT_SYSINIT(ipstat); 232SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat, 233 "IP statistics (struct ipstat, netinet/ip_var.h)"); 234 235#ifdef VIMAGE 236VNET_PCPUSTAT_SYSUNINIT(ipstat); 237#endif /* VIMAGE */ 238 239/* 240 * Kernel module interface for updating ipstat. The argument is an index 241 * into ipstat treated as an array. 242 */ 243void 244kmod_ipstat_inc(int statnum) 245{ 246 247 counter_u64_add(VNET(ipstat)[statnum], 1); 248} 249 250void 251kmod_ipstat_dec(int statnum) 252{ 253 254 counter_u64_add(VNET(ipstat)[statnum], -1); 255} 256 257static int 258sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS) 259{ 260 int error, qlimit; 261 262 netisr_getqlimit(&ip_nh, &qlimit); 263 error = sysctl_handle_int(oidp, &qlimit, 0, req); 264 if (error || !req->newptr) 265 return (error); 266 if (qlimit < 1) 267 return (EINVAL); 268 return (netisr_setqlimit(&ip_nh, qlimit)); 269} 270SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, 271 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I", 272 "Maximum size of the IP input queue"); 273 274static int 275sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS) 276{ 277 u_int64_t qdrops_long; 278 int error, qdrops; 279 280 netisr_getqdrops(&ip_nh, &qdrops_long); 281 qdrops = qdrops_long; 282 error = sysctl_handle_int(oidp, &qdrops, 0, req); 283 if (error || !req->newptr) 284 return (error); 285 if (qdrops != 0) 286 return (EINVAL); 287 netisr_clearqdrops(&ip_nh); 288 return (0); 289} 290 291SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, 292 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I", 293 "Number of packets dropped from the IP input queue"); 294 295#ifdef RSS 296static int 297sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS) 298{ 299 int error, qlimit; 300 301 netisr_getqlimit(&ip_direct_nh, &qlimit); 302 error = sysctl_handle_int(oidp, &qlimit, 0, req); 303 if (error || !req->newptr) 304 return (error); 305 if (qlimit < 1) 306 return (EINVAL); 307 return (netisr_setqlimit(&ip_direct_nh, qlimit)); 308} 309SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_direct_queue_maxlen, 310 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen, "I", 311 "Maximum size of the IP direct input queue"); 312 313static int 314sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS) 315{ 316 u_int64_t qdrops_long; 317 int error, qdrops; 318 319 netisr_getqdrops(&ip_direct_nh, &qdrops_long); 320 qdrops = qdrops_long; 321 error = sysctl_handle_int(oidp, &qdrops, 0, req); 322 if (error || !req->newptr) 323 return (error); 324 if (qdrops != 0) 325 return (EINVAL); 326 netisr_clearqdrops(&ip_direct_nh); 327 return (0); 328} 329 330SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_direct_queue_drops, 331 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I", 332 "Number of packets dropped from the IP direct input queue"); 333#endif /* RSS */ 334 335/* 336 * IP initialization: fill in IP protocol switch table. 337 * All protocols not implemented in kernel go to raw IP protocol handler. 338 */ 339void 340ip_init(void) 341{ 342 struct protosw *pr; 343 int i; 344 345 V_ip_id = time_second & 0xffff; 346 347 TAILQ_INIT(&V_in_ifaddrhead); 348 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask); 349 350 /* Initialize IP reassembly queue. */ 351 for (i = 0; i < IPREASS_NHASH; i++) 352 TAILQ_INIT(&V_ipq[i]); 353 V_maxnipq = nmbclusters / 32; 354 V_maxfragsperpacket = 16; 355 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL, 356 NULL, UMA_ALIGN_PTR, 0); 357 maxnipq_update(); 358 359 /* Initialize packet filter hooks. */ 360 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF; 361 V_inet_pfil_hook.ph_af = AF_INET; 362 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0) 363 printf("%s: WARNING: unable to register pfil hook, " 364 "error %d\n", __func__, i); 365 366 /* Skip initialization of globals for non-default instances. */ 367 if (!IS_DEFAULT_VNET(curvnet)) 368 return; 369 370 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 371 if (pr == NULL) 372 panic("ip_init: PF_INET not found"); 373 374 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */ 375 for (i = 0; i < IPPROTO_MAX; i++) 376 ip_protox[i] = pr - inetsw; 377 /* 378 * Cycle through IP protocols and put them into the appropriate place 379 * in ip_protox[]. 380 */ 381 for (pr = inetdomain.dom_protosw; 382 pr < inetdomain.dom_protoswNPROTOSW; pr++) 383 if (pr->pr_domain->dom_family == PF_INET && 384 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 385 /* Be careful to only index valid IP protocols. */ 386 if (pr->pr_protocol < IPPROTO_MAX) 387 ip_protox[pr->pr_protocol] = pr - inetsw; 388 } 389 390 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change, 391 NULL, EVENTHANDLER_PRI_ANY); 392 393 /* Initialize various other remaining things. */ 394 IPQ_LOCK_INIT(); 395 netisr_register(&ip_nh); 396#ifdef RSS 397 netisr_register(&ip_direct_nh); 398#endif 399} 400 401#ifdef VIMAGE 402void 403ip_destroy(void) 404{ 405 int i; 406 407 if ((i = pfil_head_unregister(&V_inet_pfil_hook)) != 0) 408 printf("%s: WARNING: unable to unregister pfil hook, " 409 "error %d\n", __func__, i); 410 411 /* Cleanup in_ifaddr hash table; should be empty. */ 412 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask); 413 414 IPQ_LOCK(); 415 ip_drain_locked(); 416 IPQ_UNLOCK(); 417 418 uma_zdestroy(V_ipq_zone); 419} 420#endif 421 422#ifdef RSS 423/* 424 * IP direct input routine. 425 * 426 * This is called when reinjecting completed fragments where 427 * all of the previous checking and book-keeping has been done. 428 */ 429void 430ip_direct_input(struct mbuf *m) 431{ 432 struct ip *ip; 433 int hlen; 434 435 ip = mtod(m, struct ip *); 436 hlen = ip->ip_hl << 2; 437 438 IPSTAT_INC(ips_delivered); 439 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p); 440 return; 441} 442#endif 443 444/* 445 * Ip input routine. Checksum and byte swap header. If fragmented 446 * try to reassemble. Process options. Pass to next level. 447 */ 448void 449ip_input(struct mbuf *m) 450{ 451 struct ip *ip = NULL; 452 struct in_ifaddr *ia = NULL; 453 struct ifaddr *ifa; 454 struct ifnet *ifp; 455 int checkif, hlen = 0; 456 uint16_t sum, ip_len; 457 int dchg = 0; /* dest changed after fw */ 458 struct in_addr odst; /* original dst address */ 459 460 M_ASSERTPKTHDR(m); 461 462 if (m->m_flags & M_FASTFWD_OURS) { 463 m->m_flags &= ~M_FASTFWD_OURS; 464 /* Set up some basics that will be used later. */ 465 ip = mtod(m, struct ip *); 466 hlen = ip->ip_hl << 2; 467 ip_len = ntohs(ip->ip_len); 468 goto ours; 469 } 470 471 IPSTAT_INC(ips_total); 472 473 if (m->m_pkthdr.len < sizeof(struct ip)) 474 goto tooshort; 475 476 if (m->m_len < sizeof (struct ip) && 477 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 478 IPSTAT_INC(ips_toosmall); 479 return; 480 } 481 ip = mtod(m, struct ip *); 482 483 if (ip->ip_v != IPVERSION) { 484 IPSTAT_INC(ips_badvers); 485 goto bad; 486 } 487 488 hlen = ip->ip_hl << 2; 489 if (hlen < sizeof(struct ip)) { /* minimum header length */ 490 IPSTAT_INC(ips_badhlen); 491 goto bad; 492 } 493 if (hlen > m->m_len) { 494 if ((m = m_pullup(m, hlen)) == NULL) { 495 IPSTAT_INC(ips_badhlen); 496 return; 497 } 498 ip = mtod(m, struct ip *); 499 } 500 501 IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL); 502 503 /* 127/8 must not appear on wire - RFC1122 */ 504 ifp = m->m_pkthdr.rcvif; 505 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 506 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 507 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 508 IPSTAT_INC(ips_badaddr); 509 goto bad; 510 } 511 } 512 513 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { 514 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); 515 } else { 516 if (hlen == sizeof(struct ip)) { 517 sum = in_cksum_hdr(ip); 518 } else { 519 sum = in_cksum(m, hlen); 520 } 521 } 522 if (sum) { 523 IPSTAT_INC(ips_badsum); 524 goto bad; 525 } 526 527#ifdef ALTQ 528 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) 529 /* packet is dropped by traffic conditioner */ 530 return; 531#endif 532 533 ip_len = ntohs(ip->ip_len); 534 if (ip_len < hlen) { 535 IPSTAT_INC(ips_badlen); 536 goto bad; 537 } 538 539 /* 540 * Check that the amount of data in the buffers 541 * is as at least much as the IP header would have us expect. 542 * Trim mbufs if longer than we expect. 543 * Drop packet if shorter than we expect. 544 */ 545 if (m->m_pkthdr.len < ip_len) { 546tooshort: 547 IPSTAT_INC(ips_tooshort); 548 goto bad; 549 } 550 if (m->m_pkthdr.len > ip_len) { 551 if (m->m_len == m->m_pkthdr.len) { 552 m->m_len = ip_len; 553 m->m_pkthdr.len = ip_len; 554 } else 555 m_adj(m, ip_len - m->m_pkthdr.len); 556 } 557 558#ifdef IPSEC 559 /* 560 * Bypass packet filtering for packets previously handled by IPsec. 561 */ 562 if (ip_ipsec_filtertunnel(m)) 563 goto passin; 564#endif /* IPSEC */ 565 566 /* 567 * Run through list of hooks for input packets. 568 * 569 * NB: Beware of the destination address changing (e.g. 570 * by NAT rewriting). When this happens, tell 571 * ip_forward to do the right thing. 572 */ 573 574 /* Jump over all PFIL processing if hooks are not active. */ 575 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 576 goto passin; 577 578 odst = ip->ip_dst; 579 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0) 580 return; 581 if (m == NULL) /* consumed by filter */ 582 return; 583 584 ip = mtod(m, struct ip *); 585 dchg = (odst.s_addr != ip->ip_dst.s_addr); 586 ifp = m->m_pkthdr.rcvif; 587 588 if (m->m_flags & M_FASTFWD_OURS) { 589 m->m_flags &= ~M_FASTFWD_OURS; 590 goto ours; 591 } 592 if (m->m_flags & M_IP_NEXTHOP) { 593 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL); 594 if (dchg != 0) { 595 /* 596 * Directly ship the packet on. This allows 597 * forwarding packets originally destined to us 598 * to some other directly connected host. 599 */ 600 ip_forward(m, 1); 601 return; 602 } 603 } 604passin: 605 606 /* 607 * Process options and, if not destined for us, 608 * ship it on. ip_dooptions returns 1 when an 609 * error was detected (causing an icmp message 610 * to be sent and the original packet to be freed). 611 */ 612 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0)) 613 return; 614 615 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no 616 * matter if it is destined to another node, or whether it is 617 * a multicast one, RSVP wants it! and prevents it from being forwarded 618 * anywhere else. Also checks if the rsvp daemon is running before 619 * grabbing the packet. 620 */ 621 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP) 622 goto ours; 623 624 /* 625 * Check our list of addresses, to see if the packet is for us. 626 * If we don't have any addresses, assume any unicast packet 627 * we receive might be for us (and let the upper layers deal 628 * with it). 629 */ 630 if (TAILQ_EMPTY(&V_in_ifaddrhead) && 631 (m->m_flags & (M_MCAST|M_BCAST)) == 0) 632 goto ours; 633 634 /* 635 * Enable a consistency check between the destination address 636 * and the arrival interface for a unicast packet (the RFC 1122 637 * strong ES model) if IP forwarding is disabled and the packet 638 * is not locally generated and the packet is not subject to 639 * 'ipfw fwd'. 640 * 641 * XXX - Checking also should be disabled if the destination 642 * address is ipnat'ed to a different interface. 643 * 644 * XXX - Checking is incompatible with IP aliases added 645 * to the loopback interface instead of the interface where 646 * the packets are received. 647 * 648 * XXX - This is the case for carp vhost IPs as well so we 649 * insert a workaround. If the packet got here, we already 650 * checked with carp_iamatch() and carp_forus(). 651 */ 652 checkif = V_ip_checkinterface && (V_ipforwarding == 0) && 653 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) && 654 ifp->if_carp == NULL && (dchg == 0); 655 656 /* 657 * Check for exact addresses in the hash bucket. 658 */ 659 /* IN_IFADDR_RLOCK(); */ 660 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) { 661 /* 662 * If the address matches, verify that the packet 663 * arrived via the correct interface if checking is 664 * enabled. 665 */ 666 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr && 667 (!checkif || ia->ia_ifp == ifp)) { 668 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); 669 counter_u64_add(ia->ia_ifa.ifa_ibytes, 670 m->m_pkthdr.len); 671 /* IN_IFADDR_RUNLOCK(); */ 672 goto ours; 673 } 674 } 675 /* IN_IFADDR_RUNLOCK(); */ 676 677 /* 678 * Check for broadcast addresses. 679 * 680 * Only accept broadcast packets that arrive via the matching 681 * interface. Reception of forwarded directed broadcasts would 682 * be handled via ip_forward() and ether_output() with the loopback 683 * into the stack for SIMPLEX interfaces handled by ether_output(). 684 */ 685 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) { 686 IF_ADDR_RLOCK(ifp); 687 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 688 if (ifa->ifa_addr->sa_family != AF_INET) 689 continue; 690 ia = ifatoia(ifa); 691 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 692 ip->ip_dst.s_addr) { 693 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); 694 counter_u64_add(ia->ia_ifa.ifa_ibytes, 695 m->m_pkthdr.len); 696 IF_ADDR_RUNLOCK(ifp); 697 goto ours; 698 } 699#ifdef BOOTP_COMPAT 700 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) { 701 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); 702 counter_u64_add(ia->ia_ifa.ifa_ibytes, 703 m->m_pkthdr.len); 704 IF_ADDR_RUNLOCK(ifp); 705 goto ours; 706 } 707#endif 708 } 709 IF_ADDR_RUNLOCK(ifp); 710 ia = NULL; 711 } 712 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */ 713 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { 714 IPSTAT_INC(ips_cantforward); 715 m_freem(m); 716 return; 717 } 718 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 719 if (V_ip_mrouter) { 720 /* 721 * If we are acting as a multicast router, all 722 * incoming multicast packets are passed to the 723 * kernel-level multicast forwarding function. 724 * The packet is returned (relatively) intact; if 725 * ip_mforward() returns a non-zero value, the packet 726 * must be discarded, else it may be accepted below. 727 */ 728 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) { 729 IPSTAT_INC(ips_cantforward); 730 m_freem(m); 731 return; 732 } 733 734 /* 735 * The process-level routing daemon needs to receive 736 * all multicast IGMP packets, whether or not this 737 * host belongs to their destination groups. 738 */ 739 if (ip->ip_p == IPPROTO_IGMP) 740 goto ours; 741 IPSTAT_INC(ips_forward); 742 } 743 /* 744 * Assume the packet is for us, to avoid prematurely taking 745 * a lock on the in_multi hash. Protocols must perform 746 * their own filtering and update statistics accordingly. 747 */ 748 goto ours; 749 } 750 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST) 751 goto ours; 752 if (ip->ip_dst.s_addr == INADDR_ANY) 753 goto ours; 754 755 /* 756 * FAITH(Firewall Aided Internet Translator) 757 */ 758 if (ifp && ifp->if_type == IFT_FAITH) { 759 if (V_ip_keepfaith) { 760 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP) 761 goto ours; 762 } 763 m_freem(m); 764 return; 765 } 766 767 /* 768 * Not for us; forward if possible and desirable. 769 */ 770 if (V_ipforwarding == 0) { 771 IPSTAT_INC(ips_cantforward); 772 m_freem(m); 773 } else { 774#ifdef IPSEC 775 if (ip_ipsec_fwd(m)) 776 goto bad; 777#endif /* IPSEC */ 778 ip_forward(m, dchg); 779 } 780 return; 781 782ours: 783#ifdef IPSTEALTH 784 /* 785 * IPSTEALTH: Process non-routing options only 786 * if the packet is destined for us. 787 */ 788 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) 789 return; 790#endif /* IPSTEALTH */ 791 792 /* 793 * Attempt reassembly; if it succeeds, proceed. 794 * ip_reass() will return a different mbuf. 795 */ 796 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 797 /* XXXGL: shouldn't we save & set m_flags? */ 798 m = ip_reass(m); 799 if (m == NULL) 800 return; 801 ip = mtod(m, struct ip *); 802 /* Get the header length of the reassembled packet */ 803 hlen = ip->ip_hl << 2; 804 } 805 806#ifdef IPSEC 807 /* 808 * enforce IPsec policy checking if we are seeing last header. 809 * note that we do not visit this with protocols with pcb layer 810 * code - like udp/tcp/raw ip. 811 */ 812 if (ip_ipsec_input(m)) 813 goto bad; 814#endif /* IPSEC */ 815 816 /* 817 * Switch out to protocol's input routine. 818 */ 819 IPSTAT_INC(ips_delivered); 820 821 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p); 822 return; 823bad: 824 m_freem(m); 825} 826 827/* 828 * After maxnipq has been updated, propagate the change to UMA. The UMA zone 829 * max has slightly different semantics than the sysctl, for historical 830 * reasons. 831 */ 832static void 833maxnipq_update(void) 834{ 835 836 /* 837 * -1 for unlimited allocation. 838 */ 839 if (V_maxnipq < 0) 840 uma_zone_set_max(V_ipq_zone, 0); 841 /* 842 * Positive number for specific bound. 843 */ 844 if (V_maxnipq > 0) 845 uma_zone_set_max(V_ipq_zone, V_maxnipq); 846 /* 847 * Zero specifies no further fragment queue allocation -- set the 848 * bound very low, but rely on implementation elsewhere to actually 849 * prevent allocation and reclaim current queues. 850 */ 851 if (V_maxnipq == 0) 852 uma_zone_set_max(V_ipq_zone, 1); 853} 854 855static void 856ipq_zone_change(void *tag) 857{ 858 859 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) { 860 V_maxnipq = nmbclusters / 32; 861 maxnipq_update(); 862 } 863} 864 865static int 866sysctl_maxnipq(SYSCTL_HANDLER_ARGS) 867{ 868 int error, i; 869 870 i = V_maxnipq; 871 error = sysctl_handle_int(oidp, &i, 0, req); 872 if (error || !req->newptr) 873 return (error); 874 875 /* 876 * XXXRW: Might be a good idea to sanity check the argument and place 877 * an extreme upper bound. 878 */ 879 if (i < -1) 880 return (EINVAL); 881 V_maxnipq = i; 882 maxnipq_update(); 883 return (0); 884} 885 886SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW, 887 NULL, 0, sysctl_maxnipq, "I", 888 "Maximum number of IPv4 fragment reassembly queue entries"); 889 890#define M_IP_FRAG M_PROTO9 891 892/* 893 * Take incoming datagram fragment and try to reassemble it into 894 * whole datagram. If the argument is the first fragment or one 895 * in between the function will return NULL and store the mbuf 896 * in the fragment chain. If the argument is the last fragment 897 * the packet will be reassembled and the pointer to the new 898 * mbuf returned for further processing. Only m_tags attached 899 * to the first packet/fragment are preserved. 900 * The IP header is *NOT* adjusted out of iplen. 901 */ 902struct mbuf * 903ip_reass(struct mbuf *m) 904{ 905 struct ip *ip; 906 struct mbuf *p, *q, *nq, *t; 907 struct ipq *fp = NULL; 908 struct ipqhead *head; 909 int i, hlen, next; 910 u_int8_t ecn, ecn0; 911 u_short hash; 912#ifdef RSS 913 uint32_t rss_hash, rss_type; 914#endif 915 916 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */ 917 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) { 918 IPSTAT_INC(ips_fragments); 919 IPSTAT_INC(ips_fragdropped); 920 m_freem(m); 921 return (NULL); 922 } 923 924 ip = mtod(m, struct ip *); 925 hlen = ip->ip_hl << 2; 926 927 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); 928 head = &V_ipq[hash]; 929 IPQ_LOCK(); 930 931 /* 932 * Look for queue of fragments 933 * of this datagram. 934 */ 935 TAILQ_FOREACH(fp, head, ipq_list) 936 if (ip->ip_id == fp->ipq_id && 937 ip->ip_src.s_addr == fp->ipq_src.s_addr && 938 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 939#ifdef MAC 940 mac_ipq_match(m, fp) && 941#endif 942 ip->ip_p == fp->ipq_p) 943 goto found; 944 945 fp = NULL; 946 947 /* 948 * Attempt to trim the number of allocated fragment queues if it 949 * exceeds the administrative limit. 950 */ 951 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) { 952 /* 953 * drop something from the tail of the current queue 954 * before proceeding further 955 */ 956 struct ipq *q = TAILQ_LAST(head, ipqhead); 957 if (q == NULL) { /* gak */ 958 for (i = 0; i < IPREASS_NHASH; i++) { 959 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead); 960 if (r) { 961 IPSTAT_ADD(ips_fragtimeout, 962 r->ipq_nfrags); 963 ip_freef(&V_ipq[i], r); 964 break; 965 } 966 } 967 } else { 968 IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags); 969 ip_freef(head, q); 970 } 971 } 972 973found: 974 /* 975 * Adjust ip_len to not reflect header, 976 * convert offset of this to bytes. 977 */ 978 ip->ip_len = htons(ntohs(ip->ip_len) - hlen); 979 if (ip->ip_off & htons(IP_MF)) { 980 /* 981 * Make sure that fragments have a data length 982 * that's a non-zero multiple of 8 bytes. 983 */ 984 if (ip->ip_len == htons(0) || (ntohs(ip->ip_len) & 0x7) != 0) { 985 IPSTAT_INC(ips_toosmall); /* XXX */ 986 goto dropfrag; 987 } 988 m->m_flags |= M_IP_FRAG; 989 } else 990 m->m_flags &= ~M_IP_FRAG; 991 ip->ip_off = htons(ntohs(ip->ip_off) << 3); 992 993 /* 994 * Attempt reassembly; if it succeeds, proceed. 995 * ip_reass() will return a different mbuf. 996 */ 997 IPSTAT_INC(ips_fragments); 998 m->m_pkthdr.PH_loc.ptr = ip; 999 1000 /* Previous ip_reass() started here. */ 1001 /* 1002 * Presence of header sizes in mbufs 1003 * would confuse code below. 1004 */ 1005 m->m_data += hlen; 1006 m->m_len -= hlen; 1007 1008 /* 1009 * If first fragment to arrive, create a reassembly queue. 1010 */ 1011 if (fp == NULL) { 1012 fp = uma_zalloc(V_ipq_zone, M_NOWAIT); 1013 if (fp == NULL) 1014 goto dropfrag; 1015#ifdef MAC 1016 if (mac_ipq_init(fp, M_NOWAIT) != 0) { 1017 uma_zfree(V_ipq_zone, fp); 1018 fp = NULL; 1019 goto dropfrag; 1020 } 1021 mac_ipq_create(m, fp); 1022#endif 1023 TAILQ_INSERT_HEAD(head, fp, ipq_list); 1024 V_nipq++; 1025 fp->ipq_nfrags = 1; 1026 fp->ipq_ttl = IPFRAGTTL; 1027 fp->ipq_p = ip->ip_p; 1028 fp->ipq_id = ip->ip_id; 1029 fp->ipq_src = ip->ip_src; 1030 fp->ipq_dst = ip->ip_dst; 1031 fp->ipq_frags = m; 1032 m->m_nextpkt = NULL; 1033 goto done; 1034 } else { 1035 fp->ipq_nfrags++; 1036#ifdef MAC 1037 mac_ipq_update(m, fp); 1038#endif 1039 } 1040 1041#define GETIP(m) ((struct ip*)((m)->m_pkthdr.PH_loc.ptr)) 1042 1043 /* 1044 * Handle ECN by comparing this segment with the first one; 1045 * if CE is set, do not lose CE. 1046 * drop if CE and not-ECT are mixed for the same packet. 1047 */ 1048 ecn = ip->ip_tos & IPTOS_ECN_MASK; 1049 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK; 1050 if (ecn == IPTOS_ECN_CE) { 1051 if (ecn0 == IPTOS_ECN_NOTECT) 1052 goto dropfrag; 1053 if (ecn0 != IPTOS_ECN_CE) 1054 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE; 1055 } 1056 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) 1057 goto dropfrag; 1058 1059 /* 1060 * Find a segment which begins after this one does. 1061 */ 1062 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) 1063 if (ntohs(GETIP(q)->ip_off) > ntohs(ip->ip_off)) 1064 break; 1065 1066 /* 1067 * If there is a preceding segment, it may provide some of 1068 * our data already. If so, drop the data from the incoming 1069 * segment. If it provides all of our data, drop us, otherwise 1070 * stick new segment in the proper place. 1071 * 1072 * If some of the data is dropped from the preceding 1073 * segment, then it's checksum is invalidated. 1074 */ 1075 if (p) { 1076 i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) - 1077 ntohs(ip->ip_off); 1078 if (i > 0) { 1079 if (i >= ntohs(ip->ip_len)) 1080 goto dropfrag; 1081 m_adj(m, i); 1082 m->m_pkthdr.csum_flags = 0; 1083 ip->ip_off = htons(ntohs(ip->ip_off) + i); 1084 ip->ip_len = htons(ntohs(ip->ip_len) - i); 1085 } 1086 m->m_nextpkt = p->m_nextpkt; 1087 p->m_nextpkt = m; 1088 } else { 1089 m->m_nextpkt = fp->ipq_frags; 1090 fp->ipq_frags = m; 1091 } 1092 1093 /* 1094 * While we overlap succeeding segments trim them or, 1095 * if they are completely covered, dequeue them. 1096 */ 1097 for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) > 1098 ntohs(GETIP(q)->ip_off); q = nq) { 1099 i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) - 1100 ntohs(GETIP(q)->ip_off); 1101 if (i < ntohs(GETIP(q)->ip_len)) { 1102 GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i); 1103 GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i); 1104 m_adj(q, i); 1105 q->m_pkthdr.csum_flags = 0; 1106 break; 1107 } 1108 nq = q->m_nextpkt; 1109 m->m_nextpkt = nq; 1110 IPSTAT_INC(ips_fragdropped); 1111 fp->ipq_nfrags--; 1112 m_freem(q); 1113 } 1114 1115 /* 1116 * Check for complete reassembly and perform frag per packet 1117 * limiting. 1118 * 1119 * Frag limiting is performed here so that the nth frag has 1120 * a chance to complete the packet before we drop the packet. 1121 * As a result, n+1 frags are actually allowed per packet, but 1122 * only n will ever be stored. (n = maxfragsperpacket.) 1123 * 1124 */ 1125 next = 0; 1126 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1127 if (ntohs(GETIP(q)->ip_off) != next) { 1128 if (fp->ipq_nfrags > V_maxfragsperpacket) { 1129 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); 1130 ip_freef(head, fp); 1131 } 1132 goto done; 1133 } 1134 next += ntohs(GETIP(q)->ip_len); 1135 } 1136 /* Make sure the last packet didn't have the IP_MF flag */ 1137 if (p->m_flags & M_IP_FRAG) { 1138 if (fp->ipq_nfrags > V_maxfragsperpacket) { 1139 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); 1140 ip_freef(head, fp); 1141 } 1142 goto done; 1143 } 1144 1145 /* 1146 * Reassembly is complete. Make sure the packet is a sane size. 1147 */ 1148 q = fp->ipq_frags; 1149 ip = GETIP(q); 1150 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) { 1151 IPSTAT_INC(ips_toolong); 1152 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); 1153 ip_freef(head, fp); 1154 goto done; 1155 } 1156 1157 /* 1158 * Concatenate fragments. 1159 */ 1160 m = q; 1161 t = m->m_next; 1162 m->m_next = NULL; 1163 m_cat(m, t); 1164 nq = q->m_nextpkt; 1165 q->m_nextpkt = NULL; 1166 for (q = nq; q != NULL; q = nq) { 1167 nq = q->m_nextpkt; 1168 q->m_nextpkt = NULL; 1169 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 1170 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 1171 m_cat(m, q); 1172 } 1173 /* 1174 * In order to do checksumming faster we do 'end-around carry' here 1175 * (and not in for{} loop), though it implies we are not going to 1176 * reassemble more than 64k fragments. 1177 */ 1178 while (m->m_pkthdr.csum_data & 0xffff0000) 1179 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + 1180 (m->m_pkthdr.csum_data >> 16); 1181#ifdef MAC 1182 mac_ipq_reassemble(fp, m); 1183 mac_ipq_destroy(fp); 1184#endif 1185 1186 /* 1187 * Create header for new ip packet by modifying header of first 1188 * packet; dequeue and discard fragment reassembly header. 1189 * Make header visible. 1190 */ 1191 ip->ip_len = htons((ip->ip_hl << 2) + next); 1192 ip->ip_src = fp->ipq_src; 1193 ip->ip_dst = fp->ipq_dst; 1194 TAILQ_REMOVE(head, fp, ipq_list); 1195 V_nipq--; 1196 uma_zfree(V_ipq_zone, fp); 1197 m->m_len += (ip->ip_hl << 2); 1198 m->m_data -= (ip->ip_hl << 2); 1199 /* some debugging cruft by sklower, below, will go away soon */ 1200 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */ 1201 m_fixhdr(m); 1202 IPSTAT_INC(ips_reassembled); 1203 IPQ_UNLOCK(); 1204 1205#ifdef RSS 1206 /* 1207 * Query the RSS layer for the flowid / flowtype for the 1208 * mbuf payload. 1209 * 1210 * For now, just assume we have to calculate a new one. 1211 * Later on we should check to see if the assigned flowid matches 1212 * what RSS wants for the given IP protocol and if so, just keep it. 1213 * 1214 * We then queue into the relevant netisr so it can be dispatched 1215 * to the correct CPU. 1216 * 1217 * Note - this may return 1, which means the flowid in the mbuf 1218 * is correct for the configured RSS hash types and can be used. 1219 */ 1220 if (rss_mbuf_software_hash_v4(m, 0, &rss_hash, &rss_type) == 0) { 1221 m->m_pkthdr.flowid = rss_hash; 1222 M_HASHTYPE_SET(m, rss_type); 1223 m->m_flags |= M_FLOWID; 1224 } 1225 1226 /* 1227 * Queue/dispatch for reprocessing. 1228 * 1229 * Note: this is much slower than just handling the frame in the 1230 * current receive context. It's likely worth investigating 1231 * why this is. 1232 */ 1233 netisr_dispatch(NETISR_IP_DIRECT, m); 1234 return (NULL); 1235#endif 1236 1237 /* Handle in-line */ 1238 return (m); 1239 1240dropfrag: 1241 IPSTAT_INC(ips_fragdropped); 1242 if (fp != NULL) 1243 fp->ipq_nfrags--; 1244 m_freem(m); 1245done: 1246 IPQ_UNLOCK(); 1247 return (NULL); 1248 1249#undef GETIP 1250} 1251 1252/* 1253 * Free a fragment reassembly header and all 1254 * associated datagrams. 1255 */ 1256static void 1257ip_freef(struct ipqhead *fhp, struct ipq *fp) 1258{ 1259 struct mbuf *q; 1260 1261 IPQ_LOCK_ASSERT(); 1262 1263 while (fp->ipq_frags) { 1264 q = fp->ipq_frags; 1265 fp->ipq_frags = q->m_nextpkt; 1266 m_freem(q); 1267 } 1268 TAILQ_REMOVE(fhp, fp, ipq_list); 1269 uma_zfree(V_ipq_zone, fp); 1270 V_nipq--; 1271} 1272 1273/* 1274 * IP timer processing; 1275 * if a timer expires on a reassembly 1276 * queue, discard it. 1277 */ 1278void 1279ip_slowtimo(void) 1280{ 1281 VNET_ITERATOR_DECL(vnet_iter); 1282 struct ipq *fp; 1283 int i; 1284 1285 VNET_LIST_RLOCK_NOSLEEP(); 1286 IPQ_LOCK(); 1287 VNET_FOREACH(vnet_iter) { 1288 CURVNET_SET(vnet_iter); 1289 for (i = 0; i < IPREASS_NHASH; i++) { 1290 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) { 1291 struct ipq *fpp; 1292 1293 fpp = fp; 1294 fp = TAILQ_NEXT(fp, ipq_list); 1295 if(--fpp->ipq_ttl == 0) { 1296 IPSTAT_ADD(ips_fragtimeout, 1297 fpp->ipq_nfrags); 1298 ip_freef(&V_ipq[i], fpp); 1299 } 1300 } 1301 } 1302 /* 1303 * If we are over the maximum number of fragments 1304 * (due to the limit being lowered), drain off 1305 * enough to get down to the new limit. 1306 */ 1307 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) { 1308 for (i = 0; i < IPREASS_NHASH; i++) { 1309 while (V_nipq > V_maxnipq && 1310 !TAILQ_EMPTY(&V_ipq[i])) { 1311 IPSTAT_ADD(ips_fragdropped, 1312 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags); 1313 ip_freef(&V_ipq[i], 1314 TAILQ_FIRST(&V_ipq[i])); 1315 } 1316 } 1317 } 1318 CURVNET_RESTORE(); 1319 } 1320 IPQ_UNLOCK(); 1321 VNET_LIST_RUNLOCK_NOSLEEP(); 1322} 1323 1324/* 1325 * Drain off all datagram fragments. 1326 */ 1327static void 1328ip_drain_locked(void) 1329{ 1330 int i; 1331 1332 IPQ_LOCK_ASSERT(); 1333 1334 for (i = 0; i < IPREASS_NHASH; i++) { 1335 while(!TAILQ_EMPTY(&V_ipq[i])) { 1336 IPSTAT_ADD(ips_fragdropped, 1337 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags); 1338 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i])); 1339 } 1340 } 1341} 1342 1343void 1344ip_drain(void) 1345{ 1346 VNET_ITERATOR_DECL(vnet_iter); 1347 1348 VNET_LIST_RLOCK_NOSLEEP(); 1349 IPQ_LOCK(); 1350 VNET_FOREACH(vnet_iter) { 1351 CURVNET_SET(vnet_iter); 1352 ip_drain_locked(); 1353 CURVNET_RESTORE(); 1354 } 1355 IPQ_UNLOCK(); 1356 VNET_LIST_RUNLOCK_NOSLEEP(); 1357 in_rtqdrain(); 1358} 1359 1360/* 1361 * The protocol to be inserted into ip_protox[] must be already registered 1362 * in inetsw[], either statically or through pf_proto_register(). 1363 */ 1364int 1365ipproto_register(short ipproto) 1366{ 1367 struct protosw *pr; 1368 1369 /* Sanity checks. */ 1370 if (ipproto <= 0 || ipproto >= IPPROTO_MAX) 1371 return (EPROTONOSUPPORT); 1372 1373 /* 1374 * The protocol slot must not be occupied by another protocol 1375 * already. An index pointing to IPPROTO_RAW is unused. 1376 */ 1377 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 1378 if (pr == NULL) 1379 return (EPFNOSUPPORT); 1380 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */ 1381 return (EEXIST); 1382 1383 /* Find the protocol position in inetsw[] and set the index. */ 1384 for (pr = inetdomain.dom_protosw; 1385 pr < inetdomain.dom_protoswNPROTOSW; pr++) { 1386 if (pr->pr_domain->dom_family == PF_INET && 1387 pr->pr_protocol && pr->pr_protocol == ipproto) { 1388 ip_protox[pr->pr_protocol] = pr - inetsw; 1389 return (0); 1390 } 1391 } 1392 return (EPROTONOSUPPORT); 1393} 1394 1395int 1396ipproto_unregister(short ipproto) 1397{ 1398 struct protosw *pr; 1399 1400 /* Sanity checks. */ 1401 if (ipproto <= 0 || ipproto >= IPPROTO_MAX) 1402 return (EPROTONOSUPPORT); 1403 1404 /* Check if the protocol was indeed registered. */ 1405 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 1406 if (pr == NULL) 1407 return (EPFNOSUPPORT); 1408 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */ 1409 return (ENOENT); 1410 1411 /* Reset the protocol slot to IPPROTO_RAW. */ 1412 ip_protox[ipproto] = pr - inetsw; 1413 return (0); 1414} 1415 1416/* 1417 * Given address of next destination (final or next hop), return (referenced) 1418 * internet address info of interface to be used to get there. 1419 */ 1420struct in_ifaddr * 1421ip_rtaddr(struct in_addr dst, u_int fibnum) 1422{ 1423 struct route sro; 1424 struct sockaddr_in *sin; 1425 struct in_ifaddr *ia; 1426 1427 bzero(&sro, sizeof(sro)); 1428 sin = (struct sockaddr_in *)&sro.ro_dst; 1429 sin->sin_family = AF_INET; 1430 sin->sin_len = sizeof(*sin); 1431 sin->sin_addr = dst; 1432 in_rtalloc_ign(&sro, 0, fibnum); 1433 1434 if (sro.ro_rt == NULL) 1435 return (NULL); 1436 1437 ia = ifatoia(sro.ro_rt->rt_ifa); 1438 ifa_ref(&ia->ia_ifa); 1439 RTFREE(sro.ro_rt); 1440 return (ia); 1441} 1442 1443u_char inetctlerrmap[PRC_NCMDS] = { 1444 0, 0, 0, 0, 1445 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1446 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1447 EMSGSIZE, EHOSTUNREACH, 0, 0, 1448 0, 0, EHOSTUNREACH, 0, 1449 ENOPROTOOPT, ECONNREFUSED 1450}; 1451 1452/* 1453 * Forward a packet. If some error occurs return the sender 1454 * an icmp packet. Note we can't always generate a meaningful 1455 * icmp message because icmp doesn't have a large enough repertoire 1456 * of codes and types. 1457 * 1458 * If not forwarding, just drop the packet. This could be confusing 1459 * if ipforwarding was zero but some routing protocol was advancing 1460 * us as a gateway to somewhere. However, we must let the routing 1461 * protocol deal with that. 1462 * 1463 * The srcrt parameter indicates whether the packet is being forwarded 1464 * via a source route. 1465 */ 1466void 1467ip_forward(struct mbuf *m, int srcrt) 1468{ 1469 struct ip *ip = mtod(m, struct ip *); 1470 struct in_ifaddr *ia; 1471 struct mbuf *mcopy; 1472 struct in_addr dest; 1473 struct route ro; 1474 int error, type = 0, code = 0, mtu = 0; 1475 1476 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { 1477 IPSTAT_INC(ips_cantforward); 1478 m_freem(m); 1479 return; 1480 } 1481#ifdef IPSTEALTH 1482 if (!V_ipstealth) { 1483#endif 1484 if (ip->ip_ttl <= IPTTLDEC) { 1485 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 1486 0, 0); 1487 return; 1488 } 1489#ifdef IPSTEALTH 1490 } 1491#endif 1492 1493 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m)); 1494#ifndef IPSEC 1495 /* 1496 * 'ia' may be NULL if there is no route for this destination. 1497 * In case of IPsec, Don't discard it just yet, but pass it to 1498 * ip_output in case of outgoing IPsec policy. 1499 */ 1500 if (!srcrt && ia == NULL) { 1501 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0); 1502 return; 1503 } 1504#endif 1505 1506 /* 1507 * Save the IP header and at most 8 bytes of the payload, 1508 * in case we need to generate an ICMP message to the src. 1509 * 1510 * XXX this can be optimized a lot by saving the data in a local 1511 * buffer on the stack (72 bytes at most), and only allocating the 1512 * mbuf if really necessary. The vast majority of the packets 1513 * are forwarded without having to send an ICMP back (either 1514 * because unnecessary, or because rate limited), so we are 1515 * really we are wasting a lot of work here. 1516 * 1517 * We don't use m_copy() because it might return a reference 1518 * to a shared cluster. Both this function and ip_output() 1519 * assume exclusive access to the IP header in `m', so any 1520 * data in a cluster may change before we reach icmp_error(). 1521 */ 1522 mcopy = m_gethdr(M_NOWAIT, m->m_type); 1523 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) { 1524 /* 1525 * It's probably ok if the pkthdr dup fails (because 1526 * the deep copy of the tag chain failed), but for now 1527 * be conservative and just discard the copy since 1528 * code below may some day want the tags. 1529 */ 1530 m_free(mcopy); 1531 mcopy = NULL; 1532 } 1533 if (mcopy != NULL) { 1534 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy)); 1535 mcopy->m_pkthdr.len = mcopy->m_len; 1536 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t)); 1537 } 1538 1539#ifdef IPSTEALTH 1540 if (!V_ipstealth) { 1541#endif 1542 ip->ip_ttl -= IPTTLDEC; 1543#ifdef IPSTEALTH 1544 } 1545#endif 1546 1547 /* 1548 * If forwarding packet using same interface that it came in on, 1549 * perhaps should send a redirect to sender to shortcut a hop. 1550 * Only send redirect if source is sending directly to us, 1551 * and if packet was not source routed (or has any options). 1552 * Also, don't send redirect if forwarding using a default route 1553 * or a route modified by a redirect. 1554 */ 1555 dest.s_addr = 0; 1556 if (!srcrt && V_ipsendredirects && 1557 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) { 1558 struct sockaddr_in *sin; 1559 struct rtentry *rt; 1560 1561 bzero(&ro, sizeof(ro)); 1562 sin = (struct sockaddr_in *)&ro.ro_dst; 1563 sin->sin_family = AF_INET; 1564 sin->sin_len = sizeof(*sin); 1565 sin->sin_addr = ip->ip_dst; 1566 in_rtalloc_ign(&ro, 0, M_GETFIB(m)); 1567 1568 rt = ro.ro_rt; 1569 1570 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1571 satosin(rt_key(rt))->sin_addr.s_addr != 0) { 1572#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa)) 1573 u_long src = ntohl(ip->ip_src.s_addr); 1574 1575 if (RTA(rt) && 1576 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) { 1577 if (rt->rt_flags & RTF_GATEWAY) 1578 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr; 1579 else 1580 dest.s_addr = ip->ip_dst.s_addr; 1581 /* Router requirements says to only send host redirects */ 1582 type = ICMP_REDIRECT; 1583 code = ICMP_REDIRECT_HOST; 1584 } 1585 } 1586 if (rt) 1587 RTFREE(rt); 1588 } 1589 1590 /* 1591 * Try to cache the route MTU from ip_output so we can consider it for 1592 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191. 1593 */ 1594 bzero(&ro, sizeof(ro)); 1595 1596 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL); 1597 1598 if (error == EMSGSIZE && ro.ro_rt) 1599 mtu = ro.ro_rt->rt_mtu; 1600 RO_RTFREE(&ro); 1601 1602 if (error) 1603 IPSTAT_INC(ips_cantforward); 1604 else { 1605 IPSTAT_INC(ips_forward); 1606 if (type) 1607 IPSTAT_INC(ips_redirectsent); 1608 else { 1609 if (mcopy) 1610 m_freem(mcopy); 1611 if (ia != NULL) 1612 ifa_free(&ia->ia_ifa); 1613 return; 1614 } 1615 } 1616 if (mcopy == NULL) { 1617 if (ia != NULL) 1618 ifa_free(&ia->ia_ifa); 1619 return; 1620 } 1621 1622 switch (error) { 1623 1624 case 0: /* forwarded, but need redirect */ 1625 /* type, code set above */ 1626 break; 1627 1628 case ENETUNREACH: 1629 case EHOSTUNREACH: 1630 case ENETDOWN: 1631 case EHOSTDOWN: 1632 default: 1633 type = ICMP_UNREACH; 1634 code = ICMP_UNREACH_HOST; 1635 break; 1636 1637 case EMSGSIZE: 1638 type = ICMP_UNREACH; 1639 code = ICMP_UNREACH_NEEDFRAG; 1640 1641#ifdef IPSEC 1642 /* 1643 * If IPsec is configured for this path, 1644 * override any possibly mtu value set by ip_output. 1645 */ 1646 mtu = ip_ipsec_mtu(mcopy, mtu); 1647#endif /* IPSEC */ 1648 /* 1649 * If the MTU was set before make sure we are below the 1650 * interface MTU. 1651 * If the MTU wasn't set before use the interface mtu or 1652 * fall back to the next smaller mtu step compared to the 1653 * current packet size. 1654 */ 1655 if (mtu != 0) { 1656 if (ia != NULL) 1657 mtu = min(mtu, ia->ia_ifp->if_mtu); 1658 } else { 1659 if (ia != NULL) 1660 mtu = ia->ia_ifp->if_mtu; 1661 else 1662 mtu = ip_next_mtu(ntohs(ip->ip_len), 0); 1663 } 1664 IPSTAT_INC(ips_cantfrag); 1665 break; 1666 1667 case ENOBUFS: 1668 /* 1669 * A router should not generate ICMP_SOURCEQUENCH as 1670 * required in RFC1812 Requirements for IP Version 4 Routers. 1671 * Source quench could be a big problem under DoS attacks, 1672 * or if the underlying interface is rate-limited. 1673 * Those who need source quench packets may re-enable them 1674 * via the net.inet.ip.sendsourcequench sysctl. 1675 */ 1676 if (V_ip_sendsourcequench == 0) { 1677 m_freem(mcopy); 1678 if (ia != NULL) 1679 ifa_free(&ia->ia_ifa); 1680 return; 1681 } else { 1682 type = ICMP_SOURCEQUENCH; 1683 code = 0; 1684 } 1685 break; 1686 1687 case EACCES: /* ipfw denied packet */ 1688 m_freem(mcopy); 1689 if (ia != NULL) 1690 ifa_free(&ia->ia_ifa); 1691 return; 1692 } 1693 if (ia != NULL) 1694 ifa_free(&ia->ia_ifa); 1695 icmp_error(mcopy, type, code, dest.s_addr, mtu); 1696} 1697 1698void 1699ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, 1700 struct mbuf *m) 1701{ 1702 1703 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) { 1704 struct bintime bt; 1705 1706 bintime(&bt); 1707 if (inp->inp_socket->so_options & SO_BINTIME) { 1708 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt), 1709 SCM_BINTIME, SOL_SOCKET); 1710 if (*mp) 1711 mp = &(*mp)->m_next; 1712 } 1713 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1714 struct timeval tv; 1715 1716 bintime2timeval(&bt, &tv); 1717 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), 1718 SCM_TIMESTAMP, SOL_SOCKET); 1719 if (*mp) 1720 mp = &(*mp)->m_next; 1721 } 1722 } 1723 if (inp->inp_flags & INP_RECVDSTADDR) { 1724 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst, 1725 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1726 if (*mp) 1727 mp = &(*mp)->m_next; 1728 } 1729 if (inp->inp_flags & INP_RECVTTL) { 1730 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl, 1731 sizeof(u_char), IP_RECVTTL, IPPROTO_IP); 1732 if (*mp) 1733 mp = &(*mp)->m_next; 1734 } 1735#ifdef notyet 1736 /* XXX 1737 * Moving these out of udp_input() made them even more broken 1738 * than they already were. 1739 */ 1740 /* options were tossed already */ 1741 if (inp->inp_flags & INP_RECVOPTS) { 1742 *mp = sbcreatecontrol((caddr_t)opts_deleted_above, 1743 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1744 if (*mp) 1745 mp = &(*mp)->m_next; 1746 } 1747 /* ip_srcroute doesn't do what we want here, need to fix */ 1748 if (inp->inp_flags & INP_RECVRETOPTS) { 1749 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m), 1750 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1751 if (*mp) 1752 mp = &(*mp)->m_next; 1753 } 1754#endif 1755 if (inp->inp_flags & INP_RECVIF) { 1756 struct ifnet *ifp; 1757 struct sdlbuf { 1758 struct sockaddr_dl sdl; 1759 u_char pad[32]; 1760 } sdlbuf; 1761 struct sockaddr_dl *sdp; 1762 struct sockaddr_dl *sdl2 = &sdlbuf.sdl; 1763 1764 if ((ifp = m->m_pkthdr.rcvif) && 1765 ifp->if_index && ifp->if_index <= V_if_index) { 1766 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr; 1767 /* 1768 * Change our mind and don't try copy. 1769 */ 1770 if (sdp->sdl_family != AF_LINK || 1771 sdp->sdl_len > sizeof(sdlbuf)) { 1772 goto makedummy; 1773 } 1774 bcopy(sdp, sdl2, sdp->sdl_len); 1775 } else { 1776makedummy: 1777 sdl2->sdl_len = 1778 offsetof(struct sockaddr_dl, sdl_data[0]); 1779 sdl2->sdl_family = AF_LINK; 1780 sdl2->sdl_index = 0; 1781 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; 1782 } 1783 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len, 1784 IP_RECVIF, IPPROTO_IP); 1785 if (*mp) 1786 mp = &(*mp)->m_next; 1787 } 1788 if (inp->inp_flags & INP_RECVTOS) { 1789 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos, 1790 sizeof(u_char), IP_RECVTOS, IPPROTO_IP); 1791 if (*mp) 1792 mp = &(*mp)->m_next; 1793 } 1794 1795 if (inp->inp_flags2 & INP_RECVFLOWID) { 1796 uint32_t flowid, flow_type; 1797 1798 flowid = m->m_pkthdr.flowid; 1799 flow_type = M_HASHTYPE_GET(m); 1800 1801 /* 1802 * XXX should handle the failure of one or the 1803 * other - don't populate both? 1804 */ 1805 *mp = sbcreatecontrol((caddr_t) &flowid, 1806 sizeof(uint32_t), IP_FLOWID, IPPROTO_IP); 1807 if (*mp) 1808 mp = &(*mp)->m_next; 1809 *mp = sbcreatecontrol((caddr_t) &flow_type, 1810 sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP); 1811 if (*mp) 1812 mp = &(*mp)->m_next; 1813 } 1814 1815#ifdef RSS 1816 if (inp->inp_flags2 & INP_RECVRSSBUCKETID) { 1817 uint32_t flowid, flow_type; 1818 uint32_t rss_bucketid; 1819 1820 flowid = m->m_pkthdr.flowid; 1821 flow_type = M_HASHTYPE_GET(m); 1822 1823 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) { 1824 *mp = sbcreatecontrol((caddr_t) &rss_bucketid, 1825 sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP); 1826 if (*mp) 1827 mp = &(*mp)->m_next; 1828 } 1829 } 1830#endif 1831} 1832 1833/* 1834 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the 1835 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on 1836 * locking. This code remains in ip_input.c as ip_mroute.c is optionally 1837 * compiled. 1838 */ 1839static VNET_DEFINE(int, ip_rsvp_on); 1840VNET_DEFINE(struct socket *, ip_rsvpd); 1841 1842#define V_ip_rsvp_on VNET(ip_rsvp_on) 1843 1844int 1845ip_rsvp_init(struct socket *so) 1846{ 1847 1848 if (so->so_type != SOCK_RAW || 1849 so->so_proto->pr_protocol != IPPROTO_RSVP) 1850 return EOPNOTSUPP; 1851 1852 if (V_ip_rsvpd != NULL) 1853 return EADDRINUSE; 1854 1855 V_ip_rsvpd = so; 1856 /* 1857 * This may seem silly, but we need to be sure we don't over-increment 1858 * the RSVP counter, in case something slips up. 1859 */ 1860 if (!V_ip_rsvp_on) { 1861 V_ip_rsvp_on = 1; 1862 V_rsvp_on++; 1863 } 1864 1865 return 0; 1866} 1867 1868int 1869ip_rsvp_done(void) 1870{ 1871 1872 V_ip_rsvpd = NULL; 1873 /* 1874 * This may seem silly, but we need to be sure we don't over-decrement 1875 * the RSVP counter, in case something slips up. 1876 */ 1877 if (V_ip_rsvp_on) { 1878 V_ip_rsvp_on = 0; 1879 V_rsvp_on--; 1880 } 1881 return 0; 1882} 1883 1884int 1885rsvp_input(struct mbuf **mp, int *offp, int proto) 1886{ 1887 struct mbuf *m; 1888 1889 m = *mp; 1890 *mp = NULL; 1891 1892 if (rsvp_input_p) { /* call the real one if loaded */ 1893 *mp = m; 1894 rsvp_input_p(mp, offp, proto); 1895 return (IPPROTO_DONE); 1896 } 1897 1898 /* Can still get packets with rsvp_on = 0 if there is a local member 1899 * of the group to which the RSVP packet is addressed. But in this 1900 * case we want to throw the packet away. 1901 */ 1902 1903 if (!V_rsvp_on) { 1904 m_freem(m); 1905 return (IPPROTO_DONE); 1906 } 1907 1908 if (V_ip_rsvpd != NULL) { 1909 *mp = m; 1910 rip_input(mp, offp, proto); 1911 return (IPPROTO_DONE); 1912 } 1913 /* Drop the packet */ 1914 m_freem(m); 1915 return (IPPROTO_DONE); 1916} 1917