1 /* 2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Jeffrey M. Hsu. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of The DragonFly Project nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific, prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 63 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $ 64 */ 65 66 #define _IP_VHL 67 68 #include "opt_bootp.h" 69 #include "opt_ipdn.h" 70 #include "opt_ipdivert.h" 71 #include "opt_ipstealth.h" 72 #include "opt_rss.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/mbuf.h> 77 #include <sys/malloc.h> 78 #include <sys/mpipe.h> 79 #include <sys/domain.h> 80 #include <sys/protosw.h> 81 #include <sys/socket.h> 82 #include <sys/time.h> 83 #include <sys/globaldata.h> 84 #include <sys/thread.h> 85 #include <sys/kernel.h> 86 #include <sys/syslog.h> 87 #include <sys/sysctl.h> 88 #include <sys/in_cksum.h> 89 #include <sys/lock.h> 90 91 #include <sys/mplock2.h> 92 93 #include <machine/stdarg.h> 94 95 #include <net/if.h> 96 #include <net/if_types.h> 97 #include <net/if_var.h> 98 #include <net/if_dl.h> 99 #include <net/pfil.h> 100 #include <net/route.h> 101 #include <net/netisr2.h> 102 103 #include <netinet/in.h> 104 #include <netinet/in_systm.h> 105 #include <netinet/in_var.h> 106 #include <netinet/ip.h> 107 #include <netinet/in_pcb.h> 108 #include <netinet/ip_var.h> 109 #include <netinet/ip_icmp.h> 110 #include <netinet/ip_divert.h> 111 #include <netinet/ip_flow.h> 112 113 #include <sys/thread2.h> 114 #include <sys/msgport2.h> 115 #include <net/netmsg2.h> 116 117 #include <sys/socketvar.h> 118 119 #include <net/ipfw/ip_fw.h> 120 #include <net/dummynet/ip_dummynet.h> 121 122 int rsvp_on = 0; 123 static int ip_rsvp_on; 124 struct socket *ip_rsvpd; 125 126 int ipforwarding = 0; 127 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, 128 &ipforwarding, 0, "Enable IP forwarding between interfaces"); 129 130 static int ipsendredirects = 1; /* XXX */ 131 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, 132 &ipsendredirects, 0, "Enable sending IP redirects"); 133 134 int ip_defttl = IPDEFTTL; 135 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW, 136 &ip_defttl, 0, "Maximum TTL on IP packets"); 137 138 static int ip_dosourceroute = 0; 139 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW, 140 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets"); 141 142 static int ip_acceptsourceroute = 0; 143 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, 144 CTLFLAG_RW, &ip_acceptsourceroute, 0, 145 "Enable accepting source routed IP packets"); 146 147 static int maxnipq; 148 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW, 149 &maxnipq, 0, 150 "Maximum number of IPv4 fragment reassembly queue entries"); 151 152 static int maxfragsperpacket; 153 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW, 154 &maxfragsperpacket, 0, 155 "Maximum number of IPv4 fragments allowed per packet"); 156 157 static int ip_sendsourcequench = 0; 158 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW, 159 &ip_sendsourcequench, 0, 160 "Enable the transmission of source quench packets"); 161 162 int ip_do_randomid = 1; 163 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW, 164 &ip_do_randomid, 0, 165 "Assign random ip_id values"); 166 /* 167 * XXX - Setting ip_checkinterface mostly implements the receive side of 168 * the Strong ES model described in RFC 1122, but since the routing table 169 * and transmit implementation do not implement the Strong ES model, 170 * setting this to 1 results in an odd hybrid. 171 * 172 * XXX - ip_checkinterface currently must be disabled if you use ipnat 173 * to translate the destination address to another local interface. 174 * 175 * XXX - ip_checkinterface must be disabled if you add IP aliases 176 * to the loopback interface instead of the interface where the 177 * packets for those addresses are received. 178 */ 179 static int ip_checkinterface = 0; 180 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW, 181 &ip_checkinterface, 0, "Verify packet arrives on correct interface"); 182 183 static u_long ip_hash_count = 0; 184 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD, 185 &ip_hash_count, 0, "Number of packets hashed by IP"); 186 187 #ifdef RSS_DEBUG 188 static u_long ip_rehash_count = 0; 189 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD, 190 &ip_rehash_count, 0, "Number of packets rehashed by IP"); 191 192 static u_long ip_dispatch_fast = 0; 193 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD, 194 &ip_dispatch_fast, 0, "Number of packets handled on current CPU"); 195 196 static u_long ip_dispatch_slow = 0; 197 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD, 198 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU"); 199 #endif 200 201 #ifdef DIAGNOSTIC 202 static int ipprintfs = 0; 203 #endif 204 205 extern struct domain inetdomain; 206 extern struct protosw inetsw[]; 207 u_char ip_protox[IPPROTO_MAX]; 208 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */ 209 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU]; 210 /* inet addr hash table */ 211 u_long in_ifaddrhmask; /* mask for hash table */ 212 213 static struct mbuf *ipforward_mtemp[MAXCPU]; 214 215 struct ip_stats ipstats_percpu[MAXCPU] __cachealign; 216 217 static int 218 sysctl_ipstats(SYSCTL_HANDLER_ARGS) 219 { 220 int cpu, error = 0; 221 222 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 223 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu], 224 sizeof(struct ip_stats)))) 225 break; 226 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu], 227 sizeof(struct ip_stats)))) 228 break; 229 } 230 231 return (error); 232 } 233 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 234 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics"); 235 236 /* Packet reassembly stuff */ 237 #define IPREASS_NHASH_LOG2 6 238 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) 239 #define IPREASS_HMASK (IPREASS_NHASH - 1) 240 #define IPREASS_HASH(x,y) \ 241 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK) 242 243 TAILQ_HEAD(ipqhead, ipq); 244 struct ipfrag_queue { 245 int nipq; 246 volatile int draining; 247 struct netmsg_base timeo_netmsg; 248 struct callout timeo_ch; 249 struct netmsg_base drain_netmsg; 250 struct ipqhead ipq[IPREASS_NHASH]; 251 } __cachealign; 252 253 static struct ipfrag_queue ipfrag_queue_pcpu[MAXCPU]; 254 255 #ifdef IPCTL_DEFMTU 256 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, 257 &ip_mtu, 0, "Default MTU"); 258 #endif 259 260 #ifdef IPSTEALTH 261 static int ipstealth = 0; 262 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, ""); 263 #else 264 static const int ipstealth = 0; 265 #endif 266 267 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int); 268 269 struct pfil_head inet_pfil_hook; 270 271 /* 272 * struct ip_srcrt_opt is used to store packet state while it travels 273 * through the stack. 274 * 275 * XXX Note that the code even makes assumptions on the size and 276 * alignment of fields inside struct ip_srcrt so e.g. adding some 277 * fields will break the code. This needs to be fixed. 278 * 279 * We need to save the IP options in case a protocol wants to respond 280 * to an incoming packet over the same route if the packet got here 281 * using IP source routing. This allows connection establishment and 282 * maintenance when the remote end is on a network that is not known 283 * to us. 284 */ 285 struct ip_srcrt { 286 struct in_addr dst; /* final destination */ 287 char nop; /* one NOP to align */ 288 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 289 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 290 }; 291 292 struct ip_srcrt_opt { 293 int ip_nhops; 294 struct ip_srcrt ip_srcrt; 295 }; 296 297 #define IPFRAG_MPIPE_MAX 4096 298 #define MAXIPFRAG_MIN ((IPFRAG_MPIPE_MAX * 2) / 256) 299 300 #define IPFRAG_TIMEO (hz / PR_SLOWHZ) 301 302 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management"); 303 static struct malloc_pipe ipq_mpipe; 304 305 static void save_rte(struct mbuf *, u_char *, struct in_addr); 306 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *); 307 static void ip_freef(struct ipfrag_queue *, struct ipqhead *, 308 struct ipq *); 309 static void ip_input_handler(netmsg_t); 310 311 static void ipfrag_timeo_dispatch(netmsg_t); 312 static void ipfrag_timeo(void *); 313 static void ipfrag_drain_dispatch(netmsg_t); 314 315 /* 316 * IP initialization: fill in IP protocol switch table. 317 * All protocols not implemented in kernel go to raw IP protocol handler. 318 */ 319 void 320 ip_init(void) 321 { 322 struct ipfrag_queue *fragq; 323 struct protosw *pr; 324 int cpu, i; 325 326 /* 327 * Make sure we can handle a reasonable number of fragments but 328 * cap it at IPFRAG_MPIPE_MAX. 329 */ 330 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq), 331 IFQ_MAXLEN, IPFRAG_MPIPE_MAX, 0, NULL, NULL, NULL); 332 333 /* 334 * Make in_ifaddrhead and in_ifaddrhashtbl available on all CPUs, 335 * since they could be accessed by any threads. 336 */ 337 for (cpu = 0; cpu < ncpus; ++cpu) { 338 TAILQ_INIT(&in_ifaddrheads[cpu]); 339 in_ifaddrhashtbls[cpu] = 340 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask); 341 } 342 343 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 344 if (pr == NULL) 345 panic("ip_init"); 346 for (i = 0; i < IPPROTO_MAX; i++) 347 ip_protox[i] = pr - inetsw; 348 for (pr = inetdomain.dom_protosw; 349 pr < inetdomain.dom_protoswNPROTOSW; pr++) { 350 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) { 351 if (pr->pr_protocol != IPPROTO_RAW) 352 ip_protox[pr->pr_protocol] = pr - inetsw; 353 } 354 } 355 356 inet_pfil_hook.ph_type = PFIL_TYPE_AF; 357 inet_pfil_hook.ph_af = AF_INET; 358 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) { 359 kprintf("%s: WARNING: unable to register pfil hook, " 360 "error %d\n", __func__, i); 361 } 362 363 maxnipq = (nmbclusters / 32) / netisr_ncpus; 364 if (maxnipq < MAXIPFRAG_MIN) 365 maxnipq = MAXIPFRAG_MIN; 366 maxfragsperpacket = 16; 367 368 ip_id = time_second & 0xffff; /* time_second survives reboots */ 369 370 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 371 /* 372 * Initialize IP statistics counters for each CPU. 373 */ 374 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats)); 375 376 /* 377 * Preallocate mbuf template for forwarding 378 */ 379 MGETHDR(ipforward_mtemp[cpu], M_WAITOK, MT_DATA); 380 381 /* 382 * Initialize per-cpu ip fragments queues 383 */ 384 fragq = &ipfrag_queue_pcpu[cpu]; 385 for (i = 0; i < IPREASS_NHASH; i++) 386 TAILQ_INIT(&fragq->ipq[i]); 387 388 callout_init_mp(&fragq->timeo_ch); 389 netmsg_init(&fragq->timeo_netmsg, NULL, &netisr_adone_rport, 390 MSGF_PRIORITY, ipfrag_timeo_dispatch); 391 netmsg_init(&fragq->drain_netmsg, NULL, &netisr_adone_rport, 392 MSGF_PRIORITY, ipfrag_drain_dispatch); 393 } 394 395 netisr_register(NETISR_IP, ip_input_handler, ip_hashfn); 396 netisr_register_hashcheck(NETISR_IP, ip_hashcheck); 397 398 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 399 fragq = &ipfrag_queue_pcpu[cpu]; 400 callout_reset_bycpu(&fragq->timeo_ch, IPFRAG_TIMEO, 401 ipfrag_timeo, NULL, cpu); 402 } 403 404 ip_porthash_trycount = 2 * netisr_ncpus; 405 } 406 407 /* Do transport protocol processing. */ 408 static void 409 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip) 410 { 411 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]]; 412 413 /* 414 * Switch out to protocol's input routine. 415 */ 416 PR_GET_MPLOCK(pr); 417 pr->pr_input(&m, &hlen, ip->ip_p); 418 PR_REL_MPLOCK(pr); 419 } 420 421 static void 422 transport_processing_handler(netmsg_t msg) 423 { 424 struct netmsg_packet *pmsg = &msg->packet; 425 struct ip *ip; 426 int hlen; 427 428 ip = mtod(pmsg->nm_packet, struct ip *); 429 hlen = pmsg->base.lmsg.u.ms_result; 430 431 transport_processing_oncpu(pmsg->nm_packet, hlen, ip); 432 /* msg was embedded in the mbuf, do not reply! */ 433 } 434 435 static void 436 ip_input_handler(netmsg_t msg) 437 { 438 ip_input(msg->packet.nm_packet); 439 /* msg was embedded in the mbuf, do not reply! */ 440 } 441 442 /* 443 * IP input routine. Checksum and byte swap header. If fragmented 444 * try to reassemble. Process options. Pass to next level. 445 */ 446 void 447 ip_input(struct mbuf *m) 448 { 449 struct ip *ip; 450 struct in_ifaddr *ia = NULL; 451 struct in_ifaddr_container *iac; 452 int hlen, checkif; 453 u_short sum; 454 struct in_addr pkt_dst; 455 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */ 456 struct in_addr odst; /* original dst address(NAT) */ 457 struct m_tag *mtag; 458 struct sockaddr_in *next_hop = NULL; 459 lwkt_port_t port; 460 461 ASSERT_NETISR_NCPUS(mycpuid); 462 M_ASSERTPKTHDR(m); 463 464 /* length checks already done in ip_hashfn() */ 465 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf")); 466 467 /* 468 * This routine is called from numerous places which may not have 469 * characterized the packet. 470 */ 471 ip = mtod(m, struct ip *); 472 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 473 (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK))) { 474 /* 475 * Force hash recalculation for fragments and multicast 476 * packets; hardware may not do it correctly. 477 * XXX add flag to indicate the hash is from hardware 478 */ 479 m->m_flags &= ~M_HASH; 480 } 481 if ((m->m_flags & M_HASH) == 0) { 482 ip_hashfn(&m, 0); 483 if (m == NULL) 484 return; 485 KKASSERT(m->m_flags & M_HASH); 486 487 if (&curthread->td_msgport != 488 netisr_hashport(m->m_pkthdr.hash)) { 489 netisr_queue(NETISR_IP, m); 490 /* Requeued to other netisr msgport; done */ 491 return; 492 } 493 494 /* mbuf could have been changed */ 495 ip = mtod(m, struct ip *); 496 } 497 498 /* 499 * Pull out certain tags 500 */ 501 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 502 /* Next hop */ 503 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 504 KKASSERT(mtag != NULL); 505 next_hop = m_tag_data(mtag); 506 } 507 508 if (m->m_pkthdr.fw_flags & 509 (DUMMYNET_MBUF_TAGGED | IPFW_MBUF_CONTINUE)) { 510 /* 511 * - Dummynet already filtered this packet. 512 * - This packet was processed by ipfw on another 513 * cpu, and the rest of the ipfw processing should 514 * be carried out on this cpu. 515 */ 516 ip = mtod(m, struct ip *); 517 ip->ip_len = ntohs(ip->ip_len); 518 ip->ip_off = ntohs(ip->ip_off); 519 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 520 goto iphack; 521 } 522 523 ipstat.ips_total++; 524 525 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) { 526 ipstat.ips_badvers++; 527 goto bad; 528 } 529 530 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 531 /* length checks already done in ip_hashfn() */ 532 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small")); 533 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf")); 534 535 /* 127/8 must not appear on wire - RFC1122 */ 536 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 537 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 538 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) { 539 ipstat.ips_badaddr++; 540 goto bad; 541 } 542 } 543 544 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { 545 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID); 546 } else { 547 if (hlen == sizeof(struct ip)) 548 sum = in_cksum_hdr(ip); 549 else 550 sum = in_cksum(m, hlen); 551 } 552 if (sum != 0) { 553 ipstat.ips_badsum++; 554 goto bad; 555 } 556 557 #ifdef ALTQ 558 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) { 559 /* packet is dropped by traffic conditioner */ 560 return; 561 } 562 #endif 563 /* 564 * Convert fields to host representation. 565 */ 566 ip->ip_len = ntohs(ip->ip_len); 567 ip->ip_off = ntohs(ip->ip_off); 568 569 /* length checks already done in ip_hashfn() */ 570 KASSERT(ip->ip_len >= hlen, ("total length less then header length")); 571 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short")); 572 573 /* 574 * Trim mbufs if longer than the IP header would have us expect. 575 */ 576 if (m->m_pkthdr.len > ip->ip_len) { 577 if (m->m_len == m->m_pkthdr.len) { 578 m->m_len = ip->ip_len; 579 m->m_pkthdr.len = ip->ip_len; 580 } else { 581 m_adj(m, ip->ip_len - m->m_pkthdr.len); 582 } 583 } 584 585 /* 586 * IpHack's section. 587 * Right now when no processing on packet has done 588 * and it is still fresh out of network we do our black 589 * deals with it. 590 * - Firewall: deny/allow/divert 591 * - Xlate: translate packet's addr/port (NAT). 592 * - Pipe: pass pkt through dummynet. 593 * - Wrap: fake packet's addr/port <unimpl.> 594 * - Encapsulate: put it in another IP and send out. <unimp.> 595 */ 596 597 iphack: 598 /* 599 * If we've been forwarded from the output side, then 600 * skip the firewall a second time 601 */ 602 if (next_hop != NULL) 603 goto ours; 604 605 /* No pfil hooks */ 606 if (!pfil_has_hooks(&inet_pfil_hook)) { 607 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 608 /* 609 * Strip dummynet tags from stranded packets 610 */ 611 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 612 KKASSERT(mtag != NULL); 613 m_tag_delete(m, mtag); 614 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 615 } 616 goto pass; 617 } 618 619 /* 620 * Run through list of hooks for input packets. 621 * 622 * NOTE! If the packet is rewritten pf/ipfw/whoever must 623 * clear M_HASH. 624 */ 625 odst = ip->ip_dst; 626 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 627 return; 628 if (m == NULL) /* consumed by filter */ 629 return; 630 ip = mtod(m, struct ip *); 631 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 632 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr); 633 634 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 635 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 636 KKASSERT(mtag != NULL); 637 next_hop = m_tag_data(mtag); 638 } 639 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 640 ip_dn_queue(m); 641 return; 642 } 643 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) 644 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH; 645 if (m->m_pkthdr.fw_flags & IPFW_MBUF_CONTINUE) { 646 /* ipfw was disabled/unloaded. */ 647 goto bad; 648 } 649 pass: 650 /* 651 * Process options and, if not destined for us, 652 * ship it on. ip_dooptions returns 1 when an 653 * error was detected (causing an icmp message 654 * to be sent and the original packet to be freed). 655 */ 656 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop)) 657 return; 658 659 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no 660 * matter if it is destined to another node, or whether it is 661 * a multicast one, RSVP wants it! and prevents it from being forwarded 662 * anywhere else. Also checks if the rsvp daemon is running before 663 * grabbing the packet. 664 */ 665 if (rsvp_on && ip->ip_p == IPPROTO_RSVP) 666 goto ours; 667 668 /* 669 * Check our list of addresses, to see if the packet is for us. 670 * If we don't have any addresses, assume any unicast packet 671 * we receive might be for us (and let the upper layers deal 672 * with it). 673 */ 674 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) && 675 !(m->m_flags & (M_MCAST | M_BCAST))) 676 goto ours; 677 678 /* 679 * Cache the destination address of the packet; this may be 680 * changed by use of 'ipfw fwd'. 681 */ 682 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 683 684 /* 685 * Enable a consistency check between the destination address 686 * and the arrival interface for a unicast packet (the RFC 1122 687 * strong ES model) if IP forwarding is disabled and the packet 688 * is not locally generated and the packet is not subject to 689 * 'ipfw fwd'. 690 * 691 * XXX - Checking also should be disabled if the destination 692 * address is ipnat'ed to a different interface. 693 * 694 * XXX - Checking is incompatible with IP aliases added 695 * to the loopback interface instead of the interface where 696 * the packets are received. 697 */ 698 checkif = ip_checkinterface && 699 !ipforwarding && 700 m->m_pkthdr.rcvif != NULL && 701 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 702 next_hop == NULL; 703 704 /* 705 * Check for exact addresses in the hash bucket. 706 */ 707 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) { 708 ia = iac->ia; 709 710 /* 711 * If the address matches, verify that the packet 712 * arrived via the correct interface if checking is 713 * enabled. 714 */ 715 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr && 716 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif)) 717 goto ours; 718 } 719 ia = NULL; 720 721 /* 722 * Check for broadcast addresses. 723 * 724 * Only accept broadcast packets that arrive via the matching 725 * interface. Reception of forwarded directed broadcasts would 726 * be handled via ip_forward() and ether_output() with the loopback 727 * into the stack for SIMPLEX interfaces handled by ether_output(). 728 */ 729 if (m->m_pkthdr.rcvif != NULL && 730 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 731 struct ifaddr_container *ifac; 732 733 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid], 734 ifa_link) { 735 struct ifaddr *ifa = ifac->ifa; 736 737 if (ifa->ifa_addr == NULL) /* shutdown/startup race */ 738 continue; 739 if (ifa->ifa_addr->sa_family != AF_INET) 740 continue; 741 ia = ifatoia(ifa); 742 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 743 pkt_dst.s_addr) 744 goto ours; 745 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr) 746 goto ours; 747 #ifdef BOOTP_COMPAT 748 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) 749 goto ours; 750 #endif 751 } 752 } 753 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 754 struct in_multi *inm; 755 756 if (ip_mrouter != NULL) { 757 /* XXX Multicast routing is not MPSAFE yet */ 758 get_mplock(); 759 760 /* 761 * If we are acting as a multicast router, all 762 * incoming multicast packets are passed to the 763 * kernel-level multicast forwarding function. 764 * The packet is returned (relatively) intact; if 765 * ip_mforward() returns a non-zero value, the packet 766 * must be discarded, else it may be accepted below. 767 */ 768 if (ip_mforward != NULL && 769 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) { 770 rel_mplock(); 771 ipstat.ips_cantforward++; 772 m_freem(m); 773 return; 774 } 775 776 rel_mplock(); 777 778 /* 779 * The process-level routing daemon needs to receive 780 * all multicast IGMP packets, whether or not this 781 * host belongs to their destination groups. 782 */ 783 if (ip->ip_p == IPPROTO_IGMP) 784 goto ours; 785 ipstat.ips_forward++; 786 } 787 /* 788 * See if we belong to the destination multicast group on the 789 * arrival interface. 790 */ 791 inm = IN_LOOKUP_MULTI(&ip->ip_dst, m->m_pkthdr.rcvif); 792 if (inm == NULL) { 793 ipstat.ips_notmember++; 794 m_freem(m); 795 return; 796 } 797 goto ours; 798 } 799 if (ip->ip_dst.s_addr == INADDR_BROADCAST) 800 goto ours; 801 if (ip->ip_dst.s_addr == INADDR_ANY) 802 goto ours; 803 804 /* 805 * Not for us; forward if possible and desirable. 806 */ 807 if (!ipforwarding) { 808 ipstat.ips_cantforward++; 809 m_freem(m); 810 } else { 811 ip_forward(m, using_srcrt, next_hop); 812 } 813 return; 814 815 ours: 816 817 /* 818 * IPSTEALTH: Process non-routing options only 819 * if the packet is destined for us. 820 */ 821 if (ipstealth && 822 hlen > sizeof(struct ip) && 823 ip_dooptions(m, 1, next_hop)) 824 return; 825 826 /* Count the packet in the ip address stats */ 827 if (ia != NULL) { 828 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1); 829 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len); 830 } 831 832 /* 833 * If offset or IP_MF are set, must reassemble. 834 * Otherwise, nothing need be done. 835 * (We could look in the reassembly queue to see 836 * if the packet was previously fragmented, 837 * but it's not worth the time; just let them time out.) 838 */ 839 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 840 /* 841 * Attempt reassembly; if it succeeds, proceed. ip_reass() 842 * will return a different mbuf. 843 * 844 * NOTE: ip_reass() returns m with M_HASH cleared to force 845 * us to recharacterize the packet. 846 */ 847 m = ip_reass(m); 848 if (m == NULL) 849 return; 850 ip = mtod(m, struct ip *); 851 852 /* Get the header length of the reassembled packet */ 853 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 854 } else { 855 ip->ip_len -= hlen; 856 } 857 858 859 /* 860 * We must forward the packet to the correct protocol thread if 861 * we are not already in it. 862 * 863 * NOTE: ip_len is now in host form. ip_len is not adjusted 864 * further for protocol processing, instead we pass hlen 865 * to the protosw and let it deal with it. 866 */ 867 ipstat.ips_delivered++; 868 869 if ((m->m_flags & M_HASH) == 0) { 870 #ifdef RSS_DEBUG 871 atomic_add_long(&ip_rehash_count, 1); 872 #endif 873 ip->ip_len = htons(ip->ip_len + hlen); 874 ip->ip_off = htons(ip->ip_off); 875 876 ip_hashfn(&m, 0); 877 if (m == NULL) 878 return; 879 880 ip = mtod(m, struct ip *); 881 ip->ip_len = ntohs(ip->ip_len) - hlen; 882 ip->ip_off = ntohs(ip->ip_off); 883 KKASSERT(m->m_flags & M_HASH); 884 } 885 port = netisr_hashport(m->m_pkthdr.hash); 886 887 if (port != &curthread->td_msgport) { 888 struct netmsg_packet *pmsg; 889 890 #ifdef RSS_DEBUG 891 atomic_add_long(&ip_dispatch_slow, 1); 892 #endif 893 894 pmsg = &m->m_hdr.mh_netmsg; 895 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport, 896 0, transport_processing_handler); 897 pmsg->nm_packet = m; 898 pmsg->base.lmsg.u.ms_result = hlen; 899 lwkt_sendmsg(port, &pmsg->base.lmsg); 900 } else { 901 #ifdef RSS_DEBUG 902 atomic_add_long(&ip_dispatch_fast, 1); 903 #endif 904 transport_processing_oncpu(m, hlen, ip); 905 } 906 return; 907 908 bad: 909 m_freem(m); 910 } 911 912 /* 913 * Take incoming datagram fragment and try to reassemble it into 914 * whole datagram. If a chain for reassembly of this datagram already 915 * exists, then it is given as fp; otherwise have to make a chain. 916 */ 917 struct mbuf * 918 ip_reass(struct mbuf *m) 919 { 920 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 921 struct ip *ip = mtod(m, struct ip *); 922 struct mbuf *p = NULL, *q, *nq; 923 struct mbuf *n; 924 struct ipq *fp = NULL; 925 struct ipqhead *head; 926 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 927 int i, next; 928 u_short sum; 929 930 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */ 931 if (maxnipq == 0 || maxfragsperpacket == 0) { 932 ipstat.ips_fragments++; 933 ipstat.ips_fragdropped++; 934 m_freem(m); 935 return NULL; 936 } 937 938 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); 939 /* 940 * Look for queue of fragments of this datagram. 941 */ 942 head = &fragq->ipq[sum]; 943 TAILQ_FOREACH(fp, head, ipq_list) { 944 if (ip->ip_id == fp->ipq_id && 945 ip->ip_src.s_addr == fp->ipq_src.s_addr && 946 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 947 ip->ip_p == fp->ipq_p) 948 goto found; 949 } 950 951 fp = NULL; 952 953 /* 954 * Enforce upper bound on number of fragmented packets 955 * for which we attempt reassembly; 956 * If maxnipq is -1, accept all fragments without limitation. 957 */ 958 if (fragq->nipq > maxnipq && maxnipq > 0) { 959 /* 960 * drop something from the tail of the current queue 961 * before proceeding further 962 */ 963 struct ipq *q = TAILQ_LAST(head, ipqhead); 964 if (q == NULL) { 965 /* 966 * The current queue is empty, 967 * so drop from one of the others. 968 */ 969 for (i = 0; i < IPREASS_NHASH; i++) { 970 struct ipq *r = TAILQ_LAST(&fragq->ipq[i], 971 ipqhead); 972 if (r) { 973 ipstat.ips_fragtimeout += r->ipq_nfrags; 974 ip_freef(fragq, &fragq->ipq[i], r); 975 break; 976 } 977 } 978 } else { 979 ipstat.ips_fragtimeout += q->ipq_nfrags; 980 ip_freef(fragq, head, q); 981 } 982 } 983 found: 984 /* 985 * Adjust ip_len to not reflect header, 986 * convert offset of this to bytes. 987 */ 988 ip->ip_len -= hlen; 989 if (ip->ip_off & IP_MF) { 990 /* 991 * Make sure that fragments have a data length 992 * that's a non-zero multiple of 8 bytes. 993 */ 994 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 995 ipstat.ips_toosmall++; /* XXX */ 996 m_freem(m); 997 goto done; 998 } 999 m->m_flags |= M_FRAG; 1000 } else { 1001 m->m_flags &= ~M_FRAG; 1002 } 1003 ip->ip_off <<= 3; 1004 1005 ipstat.ips_fragments++; 1006 m->m_pkthdr.header = ip; 1007 1008 /* 1009 * If the hardware has not done csum over this fragment 1010 * then csum_data is not valid at all. 1011 */ 1012 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) 1013 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) { 1014 m->m_pkthdr.csum_data = 0; 1015 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 1016 } 1017 1018 /* 1019 * Presence of header sizes in mbufs 1020 * would confuse code below. 1021 */ 1022 m->m_data += hlen; 1023 m->m_len -= hlen; 1024 1025 /* 1026 * If first fragment to arrive, create a reassembly queue. 1027 */ 1028 if (fp == NULL) { 1029 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL) 1030 goto dropfrag; 1031 TAILQ_INSERT_HEAD(head, fp, ipq_list); 1032 fragq->nipq++; 1033 fp->ipq_nfrags = 1; 1034 fp->ipq_ttl = IPFRAGTTL; 1035 fp->ipq_p = ip->ip_p; 1036 fp->ipq_id = ip->ip_id; 1037 fp->ipq_src = ip->ip_src; 1038 fp->ipq_dst = ip->ip_dst; 1039 fp->ipq_frags = m; 1040 m->m_nextpkt = NULL; 1041 goto inserted; 1042 } 1043 fp->ipq_nfrags++; 1044 1045 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header)) 1046 1047 /* 1048 * Find a segment which begins after this one does. 1049 */ 1050 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1051 if (GETIP(q)->ip_off > ip->ip_off) 1052 break; 1053 } 1054 1055 /* 1056 * If there is a preceding segment, it may provide some of 1057 * our data already. If so, drop the data from the incoming 1058 * segment. If it provides all of our data, drop us, otherwise 1059 * stick new segment in the proper place. 1060 * 1061 * If some of the data is dropped from the the preceding 1062 * segment, then it's checksum is invalidated. 1063 */ 1064 if (p) { 1065 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off; 1066 if (i > 0) { 1067 if (i >= ip->ip_len) 1068 goto dropfrag; 1069 m_adj(m, i); 1070 m->m_pkthdr.csum_flags = 0; 1071 ip->ip_off += i; 1072 ip->ip_len -= i; 1073 } 1074 m->m_nextpkt = p->m_nextpkt; 1075 p->m_nextpkt = m; 1076 } else { 1077 m->m_nextpkt = fp->ipq_frags; 1078 fp->ipq_frags = m; 1079 } 1080 1081 /* 1082 * While we overlap succeeding segments trim them or, 1083 * if they are completely covered, dequeue them. 1084 */ 1085 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off; 1086 q = nq) { 1087 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off; 1088 if (i < GETIP(q)->ip_len) { 1089 GETIP(q)->ip_len -= i; 1090 GETIP(q)->ip_off += i; 1091 m_adj(q, i); 1092 q->m_pkthdr.csum_flags = 0; 1093 break; 1094 } 1095 nq = q->m_nextpkt; 1096 m->m_nextpkt = nq; 1097 ipstat.ips_fragdropped++; 1098 fp->ipq_nfrags--; 1099 q->m_nextpkt = NULL; 1100 m_freem(q); 1101 } 1102 1103 inserted: 1104 /* 1105 * Check for complete reassembly and perform frag per packet 1106 * limiting. 1107 * 1108 * Frag limiting is performed here so that the nth frag has 1109 * a chance to complete the packet before we drop the packet. 1110 * As a result, n+1 frags are actually allowed per packet, but 1111 * only n will ever be stored. (n = maxfragsperpacket.) 1112 * 1113 */ 1114 next = 0; 1115 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 1116 if (GETIP(q)->ip_off != next) { 1117 if (fp->ipq_nfrags > maxfragsperpacket) { 1118 ipstat.ips_fragdropped += fp->ipq_nfrags; 1119 ip_freef(fragq, head, fp); 1120 } 1121 goto done; 1122 } 1123 next += GETIP(q)->ip_len; 1124 } 1125 /* Make sure the last packet didn't have the IP_MF flag */ 1126 if (p->m_flags & M_FRAG) { 1127 if (fp->ipq_nfrags > maxfragsperpacket) { 1128 ipstat.ips_fragdropped += fp->ipq_nfrags; 1129 ip_freef(fragq, head, fp); 1130 } 1131 goto done; 1132 } 1133 1134 /* 1135 * Reassembly is complete. Make sure the packet is a sane size. 1136 */ 1137 q = fp->ipq_frags; 1138 ip = GETIP(q); 1139 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) { 1140 ipstat.ips_toolong++; 1141 ipstat.ips_fragdropped += fp->ipq_nfrags; 1142 ip_freef(fragq, head, fp); 1143 goto done; 1144 } 1145 1146 /* 1147 * Concatenate fragments. 1148 */ 1149 m = q; 1150 n = m->m_next; 1151 m->m_next = NULL; 1152 m_cat(m, n); 1153 nq = q->m_nextpkt; 1154 q->m_nextpkt = NULL; 1155 for (q = nq; q != NULL; q = nq) { 1156 nq = q->m_nextpkt; 1157 q->m_nextpkt = NULL; 1158 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 1159 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 1160 m_cat(m, q); 1161 } 1162 1163 /* 1164 * Clean up the 1's complement checksum. Carry over 16 bits must 1165 * be added back. This assumes no more then 65535 packet fragments 1166 * were reassembled. A second carry can also occur (but not a third). 1167 */ 1168 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + 1169 (m->m_pkthdr.csum_data >> 16); 1170 if (m->m_pkthdr.csum_data > 0xFFFF) 1171 m->m_pkthdr.csum_data -= 0xFFFF; 1172 1173 /* 1174 * Create header for new ip packet by 1175 * modifying header of first packet; 1176 * dequeue and discard fragment reassembly header. 1177 * Make header visible. 1178 */ 1179 ip->ip_len = next; 1180 ip->ip_src = fp->ipq_src; 1181 ip->ip_dst = fp->ipq_dst; 1182 TAILQ_REMOVE(head, fp, ipq_list); 1183 fragq->nipq--; 1184 mpipe_free(&ipq_mpipe, fp); 1185 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2); 1186 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2); 1187 /* some debugging cruft by sklower, below, will go away soon */ 1188 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 1189 int plen = 0; 1190 1191 for (n = m; n; n = n->m_next) 1192 plen += n->m_len; 1193 m->m_pkthdr.len = plen; 1194 } 1195 1196 /* 1197 * Reassembly complete, return the next protocol. 1198 * 1199 * Be sure to clear M_HASH to force the packet 1200 * to be re-characterized. 1201 * 1202 * Clear M_FRAG, we are no longer a fragment. 1203 */ 1204 m->m_flags &= ~(M_HASH | M_FRAG); 1205 1206 ipstat.ips_reassembled++; 1207 return (m); 1208 1209 dropfrag: 1210 ipstat.ips_fragdropped++; 1211 if (fp != NULL) 1212 fp->ipq_nfrags--; 1213 m_freem(m); 1214 done: 1215 return (NULL); 1216 1217 #undef GETIP 1218 } 1219 1220 /* 1221 * Free a fragment reassembly header and all 1222 * associated datagrams. 1223 */ 1224 static void 1225 ip_freef(struct ipfrag_queue *fragq, struct ipqhead *fhp, struct ipq *fp) 1226 { 1227 struct mbuf *q; 1228 1229 /* 1230 * Remove first to protect against blocking 1231 */ 1232 TAILQ_REMOVE(fhp, fp, ipq_list); 1233 1234 /* 1235 * Clean out at our leisure 1236 */ 1237 while (fp->ipq_frags) { 1238 q = fp->ipq_frags; 1239 fp->ipq_frags = q->m_nextpkt; 1240 q->m_nextpkt = NULL; 1241 m_freem(q); 1242 } 1243 mpipe_free(&ipq_mpipe, fp); 1244 fragq->nipq--; 1245 } 1246 1247 /* 1248 * If a timer expires on a reassembly queue, discard it. 1249 */ 1250 static void 1251 ipfrag_timeo_dispatch(netmsg_t nmsg) 1252 { 1253 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 1254 struct ipq *fp, *fp_temp; 1255 struct ipqhead *head; 1256 int i; 1257 1258 crit_enter(); 1259 netisr_replymsg(&nmsg->base, 0); /* reply ASAP */ 1260 crit_exit(); 1261 1262 if (fragq->nipq == 0) 1263 goto done; 1264 1265 for (i = 0; i < IPREASS_NHASH; i++) { 1266 head = &fragq->ipq[i]; 1267 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) { 1268 if (--fp->ipq_ttl == 0) { 1269 ipstat.ips_fragtimeout += fp->ipq_nfrags; 1270 ip_freef(fragq, head, fp); 1271 } 1272 } 1273 } 1274 /* 1275 * If we are over the maximum number of fragments 1276 * (due to the limit being lowered), drain off 1277 * enough to get down to the new limit. 1278 */ 1279 if (maxnipq >= 0 && fragq->nipq > maxnipq) { 1280 for (i = 0; i < IPREASS_NHASH; i++) { 1281 head = &fragq->ipq[i]; 1282 while (fragq->nipq > maxnipq && !TAILQ_EMPTY(head)) { 1283 ipstat.ips_fragdropped += 1284 TAILQ_FIRST(head)->ipq_nfrags; 1285 ip_freef(fragq, head, TAILQ_FIRST(head)); 1286 } 1287 } 1288 } 1289 done: 1290 callout_reset(&fragq->timeo_ch, IPFRAG_TIMEO, ipfrag_timeo, NULL); 1291 } 1292 1293 static void 1294 ipfrag_timeo(void *dummy __unused) 1295 { 1296 struct netmsg_base *msg = &ipfrag_queue_pcpu[mycpuid].timeo_netmsg; 1297 1298 crit_enter(); 1299 if (msg->lmsg.ms_flags & MSGF_DONE) 1300 netisr_sendmsg_oncpu(msg); 1301 crit_exit(); 1302 } 1303 1304 /* 1305 * Drain off all datagram fragments. 1306 */ 1307 static void 1308 ipfrag_drain_oncpu(struct ipfrag_queue *fragq) 1309 { 1310 struct ipqhead *head; 1311 int i; 1312 1313 for (i = 0; i < IPREASS_NHASH; i++) { 1314 head = &fragq->ipq[i]; 1315 while (!TAILQ_EMPTY(head)) { 1316 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags; 1317 ip_freef(fragq, head, TAILQ_FIRST(head)); 1318 } 1319 } 1320 } 1321 1322 static void 1323 ipfrag_drain_dispatch(netmsg_t nmsg) 1324 { 1325 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid]; 1326 1327 crit_enter(); 1328 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ 1329 crit_exit(); 1330 1331 ipfrag_drain_oncpu(fragq); 1332 fragq->draining = 0; 1333 } 1334 1335 static void 1336 ipfrag_drain_ipi(void *arg __unused) 1337 { 1338 int cpu = mycpuid; 1339 struct lwkt_msg *msg = &ipfrag_queue_pcpu[cpu].drain_netmsg.lmsg; 1340 1341 crit_enter(); 1342 if (msg->ms_flags & MSGF_DONE) 1343 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); 1344 crit_exit(); 1345 } 1346 1347 static void 1348 ipfrag_drain(void) 1349 { 1350 cpumask_t mask; 1351 int cpu; 1352 1353 CPUMASK_ASSBMASK(mask, netisr_ncpus); 1354 CPUMASK_ANDMASK(mask, smp_active_mask); 1355 1356 if (IN_NETISR_NCPUS(mycpuid)) { 1357 ipfrag_drain_oncpu(&ipfrag_queue_pcpu[mycpuid]); 1358 CPUMASK_NANDBIT(mask, mycpuid); 1359 } 1360 1361 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 1362 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[cpu]; 1363 1364 if (!CPUMASK_TESTBIT(mask, cpu)) 1365 continue; 1366 1367 if (fragq->nipq == 0 || fragq->draining) { 1368 /* No fragments or is draining; skip this cpu. */ 1369 CPUMASK_NANDBIT(mask, cpu); 1370 continue; 1371 } 1372 fragq->draining = 1; 1373 } 1374 1375 if (CPUMASK_TESTNZERO(mask)) 1376 lwkt_send_ipiq_mask(mask, ipfrag_drain_ipi, NULL); 1377 } 1378 1379 void 1380 ip_drain(void) 1381 { 1382 ipfrag_drain(); 1383 in_rtqdrain(); 1384 } 1385 1386 /* 1387 * Do option processing on a datagram, 1388 * possibly discarding it if bad options are encountered, 1389 * or forwarding it if source-routed. 1390 * The pass argument is used when operating in the IPSTEALTH 1391 * mode to tell what options to process: 1392 * [LS]SRR (pass 0) or the others (pass 1). 1393 * The reason for as many as two passes is that when doing IPSTEALTH, 1394 * non-routing options should be processed only if the packet is for us. 1395 * Returns 1 if packet has been forwarded/freed, 1396 * 0 if the packet should be processed further. 1397 */ 1398 static int 1399 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop) 1400 { 1401 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET }; 1402 struct ip *ip = mtod(m, struct ip *); 1403 u_char *cp; 1404 struct in_ifaddr *ia; 1405 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB; 1406 boolean_t forward = FALSE; 1407 struct in_addr *sin, dst; 1408 n_time ntime; 1409 1410 dst = ip->ip_dst; 1411 cp = (u_char *)(ip + 1); 1412 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1413 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1414 opt = cp[IPOPT_OPTVAL]; 1415 if (opt == IPOPT_EOL) 1416 break; 1417 if (opt == IPOPT_NOP) 1418 optlen = 1; 1419 else { 1420 if (cnt < IPOPT_OLEN + sizeof(*cp)) { 1421 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1422 goto bad; 1423 } 1424 optlen = cp[IPOPT_OLEN]; 1425 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 1426 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1427 goto bad; 1428 } 1429 } 1430 switch (opt) { 1431 1432 default: 1433 break; 1434 1435 /* 1436 * Source routing with record. 1437 * Find interface with current destination address. 1438 * If none on this machine then drop if strictly routed, 1439 * or do nothing if loosely routed. 1440 * Record interface address and bring up next address 1441 * component. If strictly routed make sure next 1442 * address is on directly accessible net. 1443 */ 1444 case IPOPT_LSRR: 1445 case IPOPT_SSRR: 1446 if (ipstealth && pass > 0) 1447 break; 1448 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1449 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1450 goto bad; 1451 } 1452 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1453 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1454 goto bad; 1455 } 1456 ipaddr.sin_addr = ip->ip_dst; 1457 ia = (struct in_ifaddr *) 1458 ifa_ifwithaddr((struct sockaddr *)&ipaddr); 1459 if (ia == NULL) { 1460 if (opt == IPOPT_SSRR) { 1461 type = ICMP_UNREACH; 1462 code = ICMP_UNREACH_SRCFAIL; 1463 goto bad; 1464 } 1465 if (!ip_dosourceroute) 1466 goto nosourcerouting; 1467 /* 1468 * Loose routing, and not at next destination 1469 * yet; nothing to do except forward. 1470 */ 1471 break; 1472 } 1473 off--; /* 0 origin */ 1474 if (off > optlen - (int)sizeof(struct in_addr)) { 1475 /* 1476 * End of source route. Should be for us. 1477 */ 1478 if (!ip_acceptsourceroute) 1479 goto nosourcerouting; 1480 save_rte(m, cp, ip->ip_src); 1481 break; 1482 } 1483 if (ipstealth) 1484 goto dropit; 1485 if (!ip_dosourceroute) { 1486 if (ipforwarding) { 1487 char sbuf[INET_ADDRSTRLEN]; 1488 char dbuf[INET_ADDRSTRLEN]; 1489 1490 /* 1491 * Acting as a router, so generate ICMP 1492 */ 1493 nosourcerouting: 1494 log(LOG_WARNING, 1495 "attempted source route from %s to %s\n", 1496 kinet_ntoa(ip->ip_src, sbuf), 1497 kinet_ntoa(ip->ip_dst, dbuf)); 1498 type = ICMP_UNREACH; 1499 code = ICMP_UNREACH_SRCFAIL; 1500 goto bad; 1501 } else { 1502 /* 1503 * Not acting as a router, 1504 * so silently drop. 1505 */ 1506 dropit: 1507 ipstat.ips_cantforward++; 1508 m_freem(m); 1509 return (1); 1510 } 1511 } 1512 1513 /* 1514 * locate outgoing interface 1515 */ 1516 memcpy(&ipaddr.sin_addr, cp + off, 1517 sizeof ipaddr.sin_addr); 1518 1519 if (opt == IPOPT_SSRR) { 1520 #define INA struct in_ifaddr * 1521 #define SA struct sockaddr * 1522 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) 1523 == NULL) 1524 ia = (INA)ifa_ifwithnet((SA)&ipaddr); 1525 } else { 1526 ia = ip_rtaddr(ipaddr.sin_addr, NULL); 1527 } 1528 if (ia == NULL) { 1529 type = ICMP_UNREACH; 1530 code = ICMP_UNREACH_SRCFAIL; 1531 goto bad; 1532 } 1533 ip->ip_dst = ipaddr.sin_addr; 1534 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1535 sizeof(struct in_addr)); 1536 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1537 /* 1538 * Let ip_intr's mcast routing check handle mcast pkts 1539 */ 1540 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); 1541 break; 1542 1543 case IPOPT_RR: 1544 if (ipstealth && pass == 0) 1545 break; 1546 if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 1547 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1548 goto bad; 1549 } 1550 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 1551 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1552 goto bad; 1553 } 1554 /* 1555 * If no space remains, ignore. 1556 */ 1557 off--; /* 0 origin */ 1558 if (off > optlen - (int)sizeof(struct in_addr)) 1559 break; 1560 memcpy(&ipaddr.sin_addr, &ip->ip_dst, 1561 sizeof ipaddr.sin_addr); 1562 /* 1563 * locate outgoing interface; if we're the destination, 1564 * use the incoming interface (should be same). 1565 */ 1566 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL && 1567 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) { 1568 type = ICMP_UNREACH; 1569 code = ICMP_UNREACH_HOST; 1570 goto bad; 1571 } 1572 memcpy(cp + off, &IA_SIN(ia)->sin_addr, 1573 sizeof(struct in_addr)); 1574 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1575 break; 1576 1577 case IPOPT_TS: 1578 if (ipstealth && pass == 0) 1579 break; 1580 code = cp - (u_char *)ip; 1581 if (optlen < 4 || optlen > 40) { 1582 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1583 goto bad; 1584 } 1585 if ((off = cp[IPOPT_OFFSET]) < 5) { 1586 code = &cp[IPOPT_OLEN] - (u_char *)ip; 1587 goto bad; 1588 } 1589 if (off > optlen - (int)sizeof(int32_t)) { 1590 cp[IPOPT_OFFSET + 1] += (1 << 4); 1591 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) { 1592 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1593 goto bad; 1594 } 1595 break; 1596 } 1597 off--; /* 0 origin */ 1598 sin = (struct in_addr *)(cp + off); 1599 switch (cp[IPOPT_OFFSET + 1] & 0x0f) { 1600 1601 case IPOPT_TS_TSONLY: 1602 break; 1603 1604 case IPOPT_TS_TSANDADDR: 1605 if (off + sizeof(n_time) + 1606 sizeof(struct in_addr) > optlen) { 1607 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1608 goto bad; 1609 } 1610 ipaddr.sin_addr = dst; 1611 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1612 m->m_pkthdr.rcvif); 1613 if (ia == NULL) 1614 continue; 1615 memcpy(sin, &IA_SIN(ia)->sin_addr, 1616 sizeof(struct in_addr)); 1617 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1618 off += sizeof(struct in_addr); 1619 break; 1620 1621 case IPOPT_TS_PRESPEC: 1622 if (off + sizeof(n_time) + 1623 sizeof(struct in_addr) > optlen) { 1624 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 1625 goto bad; 1626 } 1627 memcpy(&ipaddr.sin_addr, sin, 1628 sizeof(struct in_addr)); 1629 if (ifa_ifwithaddr((SA)&ipaddr) == NULL) 1630 continue; 1631 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1632 off += sizeof(struct in_addr); 1633 break; 1634 1635 default: 1636 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip; 1637 goto bad; 1638 } 1639 ntime = iptime(); 1640 memcpy(cp + off, &ntime, sizeof(n_time)); 1641 cp[IPOPT_OFFSET] += sizeof(n_time); 1642 } 1643 } 1644 if (forward && ipforwarding) { 1645 ip_forward(m, TRUE, next_hop); 1646 return (1); 1647 } 1648 return (0); 1649 bad: 1650 icmp_error(m, type, code, 0, 0); 1651 ipstat.ips_badoptions++; 1652 return (1); 1653 } 1654 1655 /* 1656 * Given address of next destination (final or next hop), 1657 * return internet address info of interface to be used to get there. 1658 */ 1659 struct in_ifaddr * 1660 ip_rtaddr(struct in_addr dst, struct route *ro0) 1661 { 1662 struct route sro, *ro; 1663 struct sockaddr_in *sin; 1664 struct in_ifaddr *ia; 1665 1666 if (ro0 != NULL) { 1667 ro = ro0; 1668 } else { 1669 bzero(&sro, sizeof(sro)); 1670 ro = &sro; 1671 } 1672 1673 sin = (struct sockaddr_in *)&ro->ro_dst; 1674 1675 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) { 1676 if (ro->ro_rt != NULL) { 1677 RTFREE(ro->ro_rt); 1678 ro->ro_rt = NULL; 1679 } 1680 sin->sin_family = AF_INET; 1681 sin->sin_len = sizeof *sin; 1682 sin->sin_addr = dst; 1683 rtalloc_ign(ro, RTF_PRCLONING); 1684 } 1685 1686 if (ro->ro_rt == NULL) 1687 return (NULL); 1688 1689 ia = ifatoia(ro->ro_rt->rt_ifa); 1690 1691 if (ro == &sro) 1692 RTFREE(ro->ro_rt); 1693 return ia; 1694 } 1695 1696 /* 1697 * Save incoming source route for use in replies, 1698 * to be picked up later by ip_srcroute if the receiver is interested. 1699 */ 1700 static void 1701 save_rte(struct mbuf *m, u_char *option, struct in_addr dst) 1702 { 1703 struct m_tag *mtag; 1704 struct ip_srcrt_opt *opt; 1705 unsigned olen; 1706 1707 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), M_NOWAIT); 1708 if (mtag == NULL) 1709 return; 1710 opt = m_tag_data(mtag); 1711 1712 olen = option[IPOPT_OLEN]; 1713 #ifdef DIAGNOSTIC 1714 if (ipprintfs) 1715 kprintf("save_rte: olen %d\n", olen); 1716 #endif 1717 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) { 1718 m_tag_free(mtag); 1719 return; 1720 } 1721 bcopy(option, opt->ip_srcrt.srcopt, olen); 1722 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1723 opt->ip_srcrt.dst = dst; 1724 m_tag_prepend(m, mtag); 1725 } 1726 1727 /* 1728 * Retrieve incoming source route for use in replies, 1729 * in the same form used by setsockopt. 1730 * The first hop is placed before the options, will be removed later. 1731 */ 1732 struct mbuf * 1733 ip_srcroute(struct mbuf *m0) 1734 { 1735 struct in_addr *p, *q; 1736 struct mbuf *m; 1737 struct m_tag *mtag; 1738 struct ip_srcrt_opt *opt; 1739 1740 if (m0 == NULL) 1741 return NULL; 1742 1743 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL); 1744 if (mtag == NULL) 1745 return NULL; 1746 opt = m_tag_data(mtag); 1747 1748 if (opt->ip_nhops == 0) 1749 return (NULL); 1750 m = m_get(M_NOWAIT, MT_HEADER); 1751 if (m == NULL) 1752 return (NULL); 1753 1754 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt)) 1755 1756 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1757 m->m_len = opt->ip_nhops * sizeof(struct in_addr) + 1758 sizeof(struct in_addr) + OPTSIZ; 1759 #ifdef DIAGNOSTIC 1760 if (ipprintfs) { 1761 kprintf("ip_srcroute: nhops %d mlen %d", 1762 opt->ip_nhops, m->m_len); 1763 } 1764 #endif 1765 1766 /* 1767 * First save first hop for return route 1768 */ 1769 p = &opt->ip_srcrt.route[opt->ip_nhops - 1]; 1770 *(mtod(m, struct in_addr *)) = *p--; 1771 #ifdef DIAGNOSTIC 1772 if (ipprintfs) 1773 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1774 #endif 1775 1776 /* 1777 * Copy option fields and padding (nop) to mbuf. 1778 */ 1779 opt->ip_srcrt.nop = IPOPT_NOP; 1780 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1781 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop, 1782 OPTSIZ); 1783 q = (struct in_addr *)(mtod(m, caddr_t) + 1784 sizeof(struct in_addr) + OPTSIZ); 1785 #undef OPTSIZ 1786 /* 1787 * Record return path as an IP source route, 1788 * reversing the path (pointers are now aligned). 1789 */ 1790 while (p >= opt->ip_srcrt.route) { 1791 #ifdef DIAGNOSTIC 1792 if (ipprintfs) 1793 kprintf(" %x", ntohl(q->s_addr)); 1794 #endif 1795 *q++ = *p--; 1796 } 1797 /* 1798 * Last hop goes to final destination. 1799 */ 1800 *q = opt->ip_srcrt.dst; 1801 m_tag_delete(m0, mtag); 1802 #ifdef DIAGNOSTIC 1803 if (ipprintfs) 1804 kprintf(" %x\n", ntohl(q->s_addr)); 1805 #endif 1806 return (m); 1807 } 1808 1809 /* 1810 * Strip out IP options. 1811 */ 1812 void 1813 ip_stripoptions(struct mbuf *m) 1814 { 1815 int datalen; 1816 struct ip *ip = mtod(m, struct ip *); 1817 caddr_t opts; 1818 int optlen; 1819 1820 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1821 opts = (caddr_t)(ip + 1); 1822 datalen = m->m_len - (sizeof(struct ip) + optlen); 1823 bcopy(opts + optlen, opts, datalen); 1824 m->m_len -= optlen; 1825 if (m->m_flags & M_PKTHDR) 1826 m->m_pkthdr.len -= optlen; 1827 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2); 1828 } 1829 1830 u_char inetctlerrmap[PRC_NCMDS] = { 1831 0, 0, 0, 0, 1832 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1833 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1834 EMSGSIZE, EHOSTUNREACH, 0, 0, 1835 0, 0, 0, 0, 1836 ENOPROTOOPT, ECONNREFUSED 1837 }; 1838 1839 /* 1840 * Forward a packet. If some error occurs return the sender 1841 * an icmp packet. Note we can't always generate a meaningful 1842 * icmp message because icmp doesn't have a large enough repertoire 1843 * of codes and types. 1844 * 1845 * If not forwarding, just drop the packet. This could be confusing 1846 * if ipforwarding was zero but some routing protocol was advancing 1847 * us as a gateway to somewhere. However, we must let the routing 1848 * protocol deal with that. 1849 * 1850 * The using_srcrt parameter indicates whether the packet is being forwarded 1851 * via a source route. 1852 */ 1853 void 1854 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop) 1855 { 1856 struct ip *ip = mtod(m, struct ip *); 1857 struct rtentry *rt; 1858 struct route fwd_ro; 1859 int error, type = 0, code = 0, destmtu = 0; 1860 struct mbuf *mcopy, *mtemp = NULL; 1861 n_long dest; 1862 struct in_addr pkt_dst; 1863 1864 dest = INADDR_ANY; 1865 /* 1866 * Cache the destination address of the packet; this may be 1867 * changed by use of 'ipfw fwd'. 1868 */ 1869 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst; 1870 1871 #ifdef DIAGNOSTIC 1872 if (ipprintfs) 1873 kprintf("forward: src %x dst %x ttl %x\n", 1874 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl); 1875 #endif 1876 1877 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) { 1878 ipstat.ips_cantforward++; 1879 m_freem(m); 1880 return; 1881 } 1882 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) { 1883 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1884 return; 1885 } 1886 1887 bzero(&fwd_ro, sizeof(fwd_ro)); 1888 ip_rtaddr(pkt_dst, &fwd_ro); 1889 if (fwd_ro.ro_rt == NULL) { 1890 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1891 return; 1892 } 1893 rt = fwd_ro.ro_rt; 1894 1895 if (curthread->td_type == TD_TYPE_NETISR) { 1896 /* 1897 * Save the IP header and at most 8 bytes of the payload, 1898 * in case we need to generate an ICMP message to the src. 1899 */ 1900 mtemp = ipforward_mtemp[mycpuid]; 1901 KASSERT((mtemp->m_flags & M_EXT) == 0 && 1902 mtemp->m_data == mtemp->m_pktdat && 1903 m_tag_first(mtemp) == NULL, 1904 ("ip_forward invalid mtemp1")); 1905 1906 if (!m_dup_pkthdr(mtemp, m, M_NOWAIT)) { 1907 /* 1908 * It's probably ok if the pkthdr dup fails (because 1909 * the deep copy of the tag chain failed), but for now 1910 * be conservative and just discard the copy since 1911 * code below may some day want the tags. 1912 */ 1913 mtemp = NULL; 1914 } else { 1915 mtemp->m_type = m->m_type; 1916 mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8, 1917 (int)ip->ip_len); 1918 mtemp->m_pkthdr.len = mtemp->m_len; 1919 m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t)); 1920 } 1921 } 1922 1923 if (!ipstealth) 1924 ip->ip_ttl -= IPTTLDEC; 1925 1926 /* 1927 * If forwarding packet using same interface that it came in on, 1928 * perhaps should send a redirect to sender to shortcut a hop. 1929 * Only send redirect if source is sending directly to us, 1930 * and if packet was not source routed (or has any options). 1931 * Also, don't send redirect if forwarding using a default route 1932 * or a route modified by a redirect. 1933 */ 1934 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1935 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) && 1936 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY && 1937 ipsendredirects && !using_srcrt && next_hop == NULL) { 1938 u_long src = ntohl(ip->ip_src.s_addr); 1939 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa; 1940 1941 if (rt_ifa != NULL && 1942 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) { 1943 if (rt->rt_flags & RTF_GATEWAY) 1944 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1945 else 1946 dest = pkt_dst.s_addr; 1947 /* 1948 * Router requirements says to only send 1949 * host redirects. 1950 */ 1951 type = ICMP_REDIRECT; 1952 code = ICMP_REDIRECT_HOST; 1953 #ifdef DIAGNOSTIC 1954 if (ipprintfs) 1955 kprintf("redirect (%d) to %x\n", code, dest); 1956 #endif 1957 } 1958 } 1959 1960 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL); 1961 if (error == 0) { 1962 ipstat.ips_forward++; 1963 if (type == 0) { 1964 if (mtemp) 1965 ipflow_create(&fwd_ro, mtemp); 1966 goto done; 1967 } 1968 ipstat.ips_redirectsent++; 1969 } else { 1970 ipstat.ips_cantforward++; 1971 } 1972 1973 if (mtemp == NULL) 1974 goto done; 1975 1976 /* 1977 * Errors that do not require generating ICMP message 1978 */ 1979 switch (error) { 1980 case ENOBUFS: 1981 /* 1982 * A router should not generate ICMP_SOURCEQUENCH as 1983 * required in RFC1812 Requirements for IP Version 4 Routers. 1984 * Source quench could be a big problem under DoS attacks, 1985 * or if the underlying interface is rate-limited. 1986 * Those who need source quench packets may re-enable them 1987 * via the net.inet.ip.sendsourcequench sysctl. 1988 */ 1989 if (!ip_sendsourcequench) 1990 goto done; 1991 break; 1992 1993 case EACCES: /* ipfw denied packet */ 1994 goto done; 1995 } 1996 1997 KASSERT((mtemp->m_flags & M_EXT) == 0 && 1998 mtemp->m_data == mtemp->m_pktdat, 1999 ("ip_forward invalid mtemp2")); 2000 mcopy = m_copym(mtemp, 0, mtemp->m_len, M_NOWAIT); 2001 if (mcopy == NULL) 2002 goto done; 2003 2004 /* 2005 * Send ICMP message. 2006 */ 2007 switch (error) { 2008 case 0: /* forwarded, but need redirect */ 2009 /* type, code set above */ 2010 break; 2011 2012 case ENETUNREACH: /* shouldn't happen, checked above */ 2013 case EHOSTUNREACH: 2014 case ENETDOWN: 2015 case EHOSTDOWN: 2016 default: 2017 type = ICMP_UNREACH; 2018 code = ICMP_UNREACH_HOST; 2019 break; 2020 2021 case EMSGSIZE: 2022 type = ICMP_UNREACH; 2023 code = ICMP_UNREACH_NEEDFRAG; 2024 if (fwd_ro.ro_rt != NULL) 2025 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu; 2026 ipstat.ips_cantfrag++; 2027 break; 2028 2029 case ENOBUFS: 2030 type = ICMP_SOURCEQUENCH; 2031 code = 0; 2032 break; 2033 2034 case EACCES: /* ipfw denied packet */ 2035 panic("ip_forward EACCES should not reach"); 2036 } 2037 icmp_error(mcopy, type, code, dest, destmtu); 2038 done: 2039 if (mtemp != NULL) 2040 m_tag_delete_chain(mtemp); 2041 if (fwd_ro.ro_rt != NULL) 2042 RTFREE(fwd_ro.ro_rt); 2043 } 2044 2045 void 2046 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip, 2047 struct mbuf *m) 2048 { 2049 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 2050 struct timeval tv; 2051 2052 microtime(&tv); 2053 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 2054 SCM_TIMESTAMP, SOL_SOCKET); 2055 if (*mp) 2056 mp = &(*mp)->m_next; 2057 } 2058 if (inp->inp_flags & INP_RECVDSTADDR) { 2059 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 2060 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 2061 if (*mp) 2062 mp = &(*mp)->m_next; 2063 } 2064 if (inp->inp_flags & INP_RECVTTL) { 2065 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl, 2066 sizeof(u_char), IP_RECVTTL, IPPROTO_IP); 2067 if (*mp) 2068 mp = &(*mp)->m_next; 2069 } 2070 #ifdef notyet 2071 /* XXX 2072 * Moving these out of udp_input() made them even more broken 2073 * than they already were. 2074 */ 2075 /* options were tossed already */ 2076 if (inp->inp_flags & INP_RECVOPTS) { 2077 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 2078 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 2079 if (*mp) 2080 mp = &(*mp)->m_next; 2081 } 2082 /* ip_srcroute doesn't do what we want here, need to fix */ 2083 if (inp->inp_flags & INP_RECVRETOPTS) { 2084 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m), 2085 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 2086 if (*mp) 2087 mp = &(*mp)->m_next; 2088 } 2089 #endif 2090 if (inp->inp_flags & INP_RECVIF) { 2091 struct ifnet *ifp; 2092 struct sdlbuf { 2093 struct sockaddr_dl sdl; 2094 u_char pad[32]; 2095 } sdlbuf; 2096 struct sockaddr_dl *sdp; 2097 struct sockaddr_dl *sdl2 = &sdlbuf.sdl; 2098 2099 if (((ifp = m->m_pkthdr.rcvif)) && 2100 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) { 2101 sdp = IF_LLSOCKADDR(ifp); 2102 /* 2103 * Change our mind and don't try copy. 2104 */ 2105 if ((sdp->sdl_family != AF_LINK) || 2106 (sdp->sdl_len > sizeof(sdlbuf))) { 2107 goto makedummy; 2108 } 2109 bcopy(sdp, sdl2, sdp->sdl_len); 2110 } else { 2111 makedummy: 2112 sdl2->sdl_len = 2113 offsetof(struct sockaddr_dl, sdl_data[0]); 2114 sdl2->sdl_family = AF_LINK; 2115 sdl2->sdl_index = 0; 2116 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0; 2117 } 2118 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len, 2119 IP_RECVIF, IPPROTO_IP); 2120 if (*mp) 2121 mp = &(*mp)->m_next; 2122 } 2123 } 2124 2125 /* 2126 * XXX these routines are called from the upper part of the kernel. 2127 * 2128 * They could also be moved to ip_mroute.c, since all the RSVP 2129 * handling is done there already. 2130 */ 2131 int 2132 ip_rsvp_init(struct socket *so) 2133 { 2134 if (so->so_type != SOCK_RAW || 2135 so->so_proto->pr_protocol != IPPROTO_RSVP) 2136 return EOPNOTSUPP; 2137 2138 if (ip_rsvpd != NULL) 2139 return EADDRINUSE; 2140 2141 ip_rsvpd = so; 2142 /* 2143 * This may seem silly, but we need to be sure we don't over-increment 2144 * the RSVP counter, in case something slips up. 2145 */ 2146 if (!ip_rsvp_on) { 2147 ip_rsvp_on = 1; 2148 rsvp_on++; 2149 } 2150 2151 return 0; 2152 } 2153 2154 int 2155 ip_rsvp_done(void) 2156 { 2157 ip_rsvpd = NULL; 2158 /* 2159 * This may seem silly, but we need to be sure we don't over-decrement 2160 * the RSVP counter, in case something slips up. 2161 */ 2162 if (ip_rsvp_on) { 2163 ip_rsvp_on = 0; 2164 rsvp_on--; 2165 } 2166 return 0; 2167 } 2168 2169 int 2170 rsvp_input(struct mbuf **mp, int *offp, int proto) 2171 { 2172 struct mbuf *m = *mp; 2173 2174 *mp = NULL; 2175 2176 if (rsvp_input_p) { /* call the real one if loaded */ 2177 *mp = m; 2178 rsvp_input_p(mp, offp, proto); 2179 return(IPPROTO_DONE); 2180 } 2181 2182 /* Can still get packets with rsvp_on = 0 if there is a local member 2183 * of the group to which the RSVP packet is addressed. But in this 2184 * case we want to throw the packet away. 2185 */ 2186 2187 if (!rsvp_on) { 2188 m_freem(m); 2189 return(IPPROTO_DONE); 2190 } 2191 2192 if (ip_rsvpd != NULL) { 2193 *mp = m; 2194 rip_input(mp, offp, proto); 2195 return(IPPROTO_DONE); 2196 } 2197 /* Drop the packet */ 2198 m_freem(m); 2199 return(IPPROTO_DONE); 2200 } 2201