1 /* $NetBSD: ip_input.c,v 1.80 1999/01/19 23:39:57 mycroft Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 73 */ 74 75 #include "opt_gateway.h" 76 #include "opt_pfil_hooks.h" 77 #include "opt_mrouting.h" 78 79 #include <sys/param.h> 80 #include <sys/systm.h> 81 #include <sys/malloc.h> 82 #include <sys/mbuf.h> 83 #include <sys/domain.h> 84 #include <sys/protosw.h> 85 #include <sys/socket.h> 86 #include <sys/socketvar.h> 87 #include <sys/errno.h> 88 #include <sys/time.h> 89 #include <sys/kernel.h> 90 #include <sys/proc.h> 91 #include <sys/pool.h> 92 93 #include <vm/vm.h> 94 #include <sys/sysctl.h> 95 96 #include <net/if.h> 97 #include <net/if_dl.h> 98 #include <net/route.h> 99 #include <net/pfil.h> 100 101 #include <netinet/in.h> 102 #include <netinet/in_systm.h> 103 #include <netinet/ip.h> 104 #include <netinet/in_pcb.h> 105 #include <netinet/in_var.h> 106 #include <netinet/ip_var.h> 107 #include <netinet/ip_icmp.h> 108 109 #ifndef IPFORWARDING 110 #ifdef GATEWAY 111 #define IPFORWARDING 1 /* forward IP packets not for us */ 112 #else /* GATEWAY */ 113 #define IPFORWARDING 0 /* don't forward IP packets not for us */ 114 #endif /* GATEWAY */ 115 #endif /* IPFORWARDING */ 116 #ifndef IPSENDREDIRECTS 117 #define IPSENDREDIRECTS 1 118 #endif 119 #ifndef IPFORWSRCRT 120 #define IPFORWSRCRT 1 /* forward source-routed packets */ 121 #endif 122 #ifndef IPALLOWSRCRT 123 #define IPALLOWSRCRT 1 /* allow source-routed packets */ 124 #endif 125 #ifndef IPMTUDISC 126 #define IPMTUDISC 0 127 #endif 128 #ifndef IPMTUDISCTIMEOUT 129 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */ 130 #endif 131 132 /* 133 * Note: DIRECTED_BROADCAST is handled this way so that previous 134 * configuration using this option will Just Work. 135 */ 136 #ifndef IPDIRECTEDBCAST 137 #ifdef DIRECTED_BROADCAST 138 #define IPDIRECTEDBCAST 1 139 #else 140 #define IPDIRECTEDBCAST 0 141 #endif /* DIRECTED_BROADCAST */ 142 #endif /* IPDIRECTEDBCAST */ 143 int ipforwarding = IPFORWARDING; 144 int ipsendredirects = IPSENDREDIRECTS; 145 int ip_defttl = IPDEFTTL; 146 int ip_forwsrcrt = IPFORWSRCRT; 147 int ip_directedbcast = IPDIRECTEDBCAST; 148 int ip_allowsrcrt = IPALLOWSRCRT; 149 int ip_mtudisc = IPMTUDISC; 150 u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT; 151 #ifdef DIAGNOSTIC 152 int ipprintfs = 0; 153 #endif 154 155 struct rttimer_queue *ip_mtudisc_timeout_q = NULL; 156 157 extern struct domain inetdomain; 158 extern struct protosw inetsw[]; 159 u_char ip_protox[IPPROTO_MAX]; 160 int ipqmaxlen = IFQ_MAXLEN; 161 struct in_ifaddrhead in_ifaddr; 162 struct in_ifaddrhashhead *in_ifaddrhashtbl; 163 struct ifqueue ipintrq; 164 struct ipstat ipstat; 165 u_int16_t ip_id; 166 int ip_defttl; 167 168 struct ipqhead ipq; 169 int ipq_locked; 170 171 static __inline int ipq_lock_try __P((void)); 172 static __inline void ipq_unlock __P((void)); 173 174 static __inline int 175 ipq_lock_try() 176 { 177 int s; 178 179 s = splimp(); 180 if (ipq_locked) { 181 splx(s); 182 return (0); 183 } 184 ipq_locked = 1; 185 splx(s); 186 return (1); 187 } 188 189 static __inline void 190 ipq_unlock() 191 { 192 int s; 193 194 s = splimp(); 195 ipq_locked = 0; 196 splx(s); 197 } 198 199 #ifdef DIAGNOSTIC 200 #define IPQ_LOCK() \ 201 do { \ 202 if (ipq_lock_try() == 0) { \ 203 printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \ 204 panic("ipq_lock"); \ 205 } \ 206 } while (0) 207 #define IPQ_LOCK_CHECK() \ 208 do { \ 209 if (ipq_locked == 0) { \ 210 printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \ 211 panic("ipq lock check"); \ 212 } \ 213 } while (0) 214 #else 215 #define IPQ_LOCK() (void) ipq_lock_try() 216 #define IPQ_LOCK_CHECK() /* nothing */ 217 #endif 218 219 #define IPQ_UNLOCK() ipq_unlock() 220 221 struct pool ipqent_pool; 222 223 /* 224 * We need to save the IP options in case a protocol wants to respond 225 * to an incoming packet over the same route if the packet got here 226 * using IP source routing. This allows connection establishment and 227 * maintenance when the remote end is on a network that is not known 228 * to us. 229 */ 230 int ip_nhops = 0; 231 static struct ip_srcrt { 232 struct in_addr dst; /* final destination */ 233 char nop; /* one NOP to align */ 234 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 235 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 236 } ip_srcrt; 237 238 static void save_rte __P((u_char *, struct in_addr)); 239 240 /* 241 * IP initialization: fill in IP protocol switch table. 242 * All protocols not implemented in kernel go to raw IP protocol handler. 243 */ 244 void 245 ip_init() 246 { 247 register struct protosw *pr; 248 register int i; 249 250 pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl", 251 0, NULL, NULL, M_IPQ); 252 253 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 254 if (pr == 0) 255 panic("ip_init"); 256 for (i = 0; i < IPPROTO_MAX; i++) 257 ip_protox[i] = pr - inetsw; 258 for (pr = inetdomain.dom_protosw; 259 pr < inetdomain.dom_protoswNPROTOSW; pr++) 260 if (pr->pr_domain->dom_family == PF_INET && 261 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 262 ip_protox[pr->pr_protocol] = pr - inetsw; 263 LIST_INIT(&ipq); 264 ip_id = time.tv_sec & 0xffff; 265 ipintrq.ifq_maxlen = ipqmaxlen; 266 TAILQ_INIT(&in_ifaddr); 267 in_ifaddrhashtbl = 268 hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash); 269 if (ip_mtudisc != 0) 270 ip_mtudisc_timeout_q = 271 rt_timer_queue_create(ip_mtudisc_timeout); 272 #ifdef GATEWAY 273 ipflow_init(); 274 #endif 275 } 276 277 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 278 struct route ipforward_rt; 279 280 /* 281 * Ip input routine. Checksum and byte swap header. If fragmented 282 * try to reassemble. Process options. Pass to next level. 283 */ 284 void 285 ipintr() 286 { 287 register struct ip *ip = NULL; 288 register struct mbuf *m; 289 register struct ipq *fp; 290 register struct in_ifaddr *ia; 291 register struct ifaddr *ifa; 292 struct ipqent *ipqe; 293 int hlen = 0, mff, len, s; 294 #ifdef PFIL_HOOKS 295 struct packet_filter_hook *pfh; 296 struct mbuf *m0; 297 int rv; 298 #endif /* PFIL_HOOKS */ 299 300 next: 301 /* 302 * Get next datagram off input queue and get IP header 303 * in first mbuf. 304 */ 305 s = splimp(); 306 IF_DEQUEUE(&ipintrq, m); 307 splx(s); 308 if (m == 0) 309 return; 310 #ifdef DIAGNOSTIC 311 if ((m->m_flags & M_PKTHDR) == 0) 312 panic("ipintr no HDR"); 313 #endif 314 /* 315 * If no IP addresses have been set yet but the interfaces 316 * are receiving, can't do anything with incoming packets yet. 317 */ 318 if (in_ifaddr.tqh_first == 0) 319 goto bad; 320 ipstat.ips_total++; 321 if (m->m_len < sizeof (struct ip) && 322 (m = m_pullup(m, sizeof (struct ip))) == 0) { 323 ipstat.ips_toosmall++; 324 goto next; 325 } 326 ip = mtod(m, struct ip *); 327 if (ip->ip_v != IPVERSION) { 328 ipstat.ips_badvers++; 329 goto bad; 330 } 331 hlen = ip->ip_hl << 2; 332 if (hlen < sizeof(struct ip)) { /* minimum header length */ 333 ipstat.ips_badhlen++; 334 goto bad; 335 } 336 if (hlen > m->m_len) { 337 if ((m = m_pullup(m, hlen)) == 0) { 338 ipstat.ips_badhlen++; 339 goto next; 340 } 341 ip = mtod(m, struct ip *); 342 } 343 if (in_cksum(m, hlen) != 0) { 344 ipstat.ips_badsum++; 345 goto bad; 346 } 347 348 /* 349 * Convert fields to host representation. 350 */ 351 NTOHS(ip->ip_len); 352 NTOHS(ip->ip_off); 353 len = ip->ip_len; 354 355 /* 356 * Check that the amount of data in the buffers 357 * is as at least much as the IP header would have us expect. 358 * Trim mbufs if longer than we expect. 359 * Drop packet if shorter than we expect. 360 */ 361 if (m->m_pkthdr.len < len) { 362 ipstat.ips_tooshort++; 363 goto bad; 364 } 365 if (m->m_pkthdr.len > len) { 366 if (m->m_len == m->m_pkthdr.len) { 367 m->m_len = len; 368 m->m_pkthdr.len = len; 369 } else 370 m_adj(m, len - m->m_pkthdr.len); 371 } 372 373 /* 374 * Assume that we can create a fast-forward IP flow entry 375 * based on this packet. 376 */ 377 m->m_flags |= M_CANFASTFWD; 378 379 #ifdef PFIL_HOOKS 380 /* 381 * Run through list of hooks for input packets. If there are any 382 * filters which require that additional packets in the flow are 383 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 384 * Note that filters must _never_ set this flag, as another filter 385 * in the list may have previously cleared it. 386 */ 387 m0 = m; 388 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next) 389 if (pfh->pfil_func) { 390 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0); 391 if (rv) 392 goto next; 393 m = m0; 394 if (m == NULL) 395 goto next; 396 ip = mtod(m, struct ip *); 397 } 398 #endif /* PFIL_HOOKS */ 399 400 /* 401 * Process options and, if not destined for us, 402 * ship it on. ip_dooptions returns 1 when an 403 * error was detected (causing an icmp message 404 * to be sent and the original packet to be freed). 405 */ 406 ip_nhops = 0; /* for source routed packets */ 407 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 408 goto next; 409 410 /* 411 * Check our list of addresses, to see if the packet is for us. 412 */ 413 INADDR_TO_IA(ip->ip_dst, ia); 414 if (ia != NULL) goto ours; 415 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 416 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 417 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 418 if (ifa->ifa_addr->sa_family != AF_INET) continue; 419 ia = ifatoia(ifa); 420 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 421 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 422 /* 423 * Look for all-0's host part (old broadcast addr), 424 * either for subnet or net. 425 */ 426 ip->ip_dst.s_addr == ia->ia_subnet || 427 ip->ip_dst.s_addr == ia->ia_net) 428 goto ours; 429 /* 430 * An interface with IP address zero accepts 431 * all packets that arrive on that interface. 432 */ 433 if (in_nullhost(ia->ia_addr.sin_addr)) 434 goto ours; 435 } 436 } 437 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 438 struct in_multi *inm; 439 #ifdef MROUTING 440 extern struct socket *ip_mrouter; 441 442 if (m->m_flags & M_EXT) { 443 if ((m = m_pullup(m, hlen)) == 0) { 444 ipstat.ips_toosmall++; 445 goto next; 446 } 447 ip = mtod(m, struct ip *); 448 } 449 450 if (ip_mrouter) { 451 /* 452 * If we are acting as a multicast router, all 453 * incoming multicast packets are passed to the 454 * kernel-level multicast forwarding function. 455 * The packet is returned (relatively) intact; if 456 * ip_mforward() returns a non-zero value, the packet 457 * must be discarded, else it may be accepted below. 458 * 459 * (The IP ident field is put in the same byte order 460 * as expected when ip_mforward() is called from 461 * ip_output().) 462 */ 463 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 464 ipstat.ips_cantforward++; 465 m_freem(m); 466 goto next; 467 } 468 469 /* 470 * The process-level routing demon needs to receive 471 * all multicast IGMP packets, whether or not this 472 * host belongs to their destination groups. 473 */ 474 if (ip->ip_p == IPPROTO_IGMP) 475 goto ours; 476 ipstat.ips_forward++; 477 } 478 #endif 479 /* 480 * See if we belong to the destination multicast group on the 481 * arrival interface. 482 */ 483 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 484 if (inm == NULL) { 485 ipstat.ips_cantforward++; 486 m_freem(m); 487 goto next; 488 } 489 goto ours; 490 } 491 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 492 in_nullhost(ip->ip_dst)) 493 goto ours; 494 495 /* 496 * Not for us; forward if possible and desirable. 497 */ 498 if (ipforwarding == 0) { 499 ipstat.ips_cantforward++; 500 m_freem(m); 501 } else 502 ip_forward(m, 0); 503 goto next; 504 505 ours: 506 /* 507 * If offset or IP_MF are set, must reassemble. 508 * Otherwise, nothing need be done. 509 * (We could look in the reassembly queue to see 510 * if the packet was previously fragmented, 511 * but it's not worth the time; just let them time out.) 512 */ 513 if (ip->ip_off & ~(IP_DF|IP_RF)) { 514 /* 515 * Look for queue of fragments 516 * of this datagram. 517 */ 518 IPQ_LOCK(); 519 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 520 if (ip->ip_id == fp->ipq_id && 521 in_hosteq(ip->ip_src, fp->ipq_src) && 522 in_hosteq(ip->ip_dst, fp->ipq_dst) && 523 ip->ip_p == fp->ipq_p) 524 goto found; 525 fp = 0; 526 found: 527 528 /* 529 * Adjust ip_len to not reflect header, 530 * set ipqe_mff if more fragments are expected, 531 * convert offset of this to bytes. 532 */ 533 ip->ip_len -= hlen; 534 mff = (ip->ip_off & IP_MF) != 0; 535 if (mff) { 536 /* 537 * Make sure that fragments have a data length 538 * that's a non-zero multiple of 8 bytes. 539 */ 540 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 541 ipstat.ips_badfrags++; 542 IPQ_UNLOCK(); 543 goto bad; 544 } 545 } 546 ip->ip_off <<= 3; 547 548 /* 549 * If datagram marked as having more fragments 550 * or if this is not the first fragment, 551 * attempt reassembly; if it succeeds, proceed. 552 */ 553 if (mff || ip->ip_off) { 554 ipstat.ips_fragments++; 555 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 556 if (ipqe == NULL) { 557 ipstat.ips_rcvmemdrop++; 558 IPQ_UNLOCK(); 559 goto bad; 560 } 561 ipqe->ipqe_mff = mff; 562 ipqe->ipqe_m = m; 563 ipqe->ipqe_ip = ip; 564 m = ip_reass(ipqe, fp); 565 if (m == 0) { 566 IPQ_UNLOCK(); 567 goto next; 568 } 569 ipstat.ips_reassembled++; 570 ip = mtod(m, struct ip *); 571 hlen = ip->ip_hl << 2; 572 ip->ip_len += hlen; 573 } else 574 if (fp) 575 ip_freef(fp); 576 IPQ_UNLOCK(); 577 } 578 579 /* 580 * Switch out to protocol's input routine. 581 */ 582 ipstat.ips_delivered++; 583 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 584 goto next; 585 bad: 586 m_freem(m); 587 goto next; 588 } 589 590 /* 591 * Take incoming datagram fragment and try to 592 * reassemble it into whole datagram. If a chain for 593 * reassembly of this datagram already exists, then it 594 * is given as fp; otherwise have to make a chain. 595 */ 596 struct mbuf * 597 ip_reass(ipqe, fp) 598 register struct ipqent *ipqe; 599 register struct ipq *fp; 600 { 601 register struct mbuf *m = ipqe->ipqe_m; 602 register struct ipqent *nq, *p, *q; 603 struct ip *ip; 604 struct mbuf *t; 605 int hlen = ipqe->ipqe_ip->ip_hl << 2; 606 int i, next; 607 608 IPQ_LOCK_CHECK(); 609 610 /* 611 * Presence of header sizes in mbufs 612 * would confuse code below. 613 */ 614 m->m_data += hlen; 615 m->m_len -= hlen; 616 617 /* 618 * If first fragment to arrive, create a reassembly queue. 619 */ 620 if (fp == 0) { 621 MALLOC(fp, struct ipq *, sizeof (struct ipq), 622 M_FTABLE, M_NOWAIT); 623 if (fp == NULL) 624 goto dropfrag; 625 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 626 fp->ipq_ttl = IPFRAGTTL; 627 fp->ipq_p = ipqe->ipqe_ip->ip_p; 628 fp->ipq_id = ipqe->ipqe_ip->ip_id; 629 LIST_INIT(&fp->ipq_fragq); 630 fp->ipq_src = ipqe->ipqe_ip->ip_src; 631 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 632 p = NULL; 633 goto insert; 634 } 635 636 /* 637 * Find a segment which begins after this one does. 638 */ 639 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 640 p = q, q = q->ipqe_q.le_next) 641 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 642 break; 643 644 /* 645 * If there is a preceding segment, it may provide some of 646 * our data already. If so, drop the data from the incoming 647 * segment. If it provides all of our data, drop us. 648 */ 649 if (p != NULL) { 650 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 651 ipqe->ipqe_ip->ip_off; 652 if (i > 0) { 653 if (i >= ipqe->ipqe_ip->ip_len) 654 goto dropfrag; 655 m_adj(ipqe->ipqe_m, i); 656 ipqe->ipqe_ip->ip_off += i; 657 ipqe->ipqe_ip->ip_len -= i; 658 } 659 } 660 661 /* 662 * While we overlap succeeding segments trim them or, 663 * if they are completely covered, dequeue them. 664 */ 665 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 666 q->ipqe_ip->ip_off; q = nq) { 667 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 668 q->ipqe_ip->ip_off; 669 if (i < q->ipqe_ip->ip_len) { 670 q->ipqe_ip->ip_len -= i; 671 q->ipqe_ip->ip_off += i; 672 m_adj(q->ipqe_m, i); 673 break; 674 } 675 nq = q->ipqe_q.le_next; 676 m_freem(q->ipqe_m); 677 LIST_REMOVE(q, ipqe_q); 678 pool_put(&ipqent_pool, q); 679 } 680 681 insert: 682 /* 683 * Stick new segment in its place; 684 * check for complete reassembly. 685 */ 686 if (p == NULL) { 687 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 688 } else { 689 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 690 } 691 next = 0; 692 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 693 p = q, q = q->ipqe_q.le_next) { 694 if (q->ipqe_ip->ip_off != next) 695 return (0); 696 next += q->ipqe_ip->ip_len; 697 } 698 if (p->ipqe_mff) 699 return (0); 700 701 /* 702 * Reassembly is complete. Check for a bogus message size and 703 * concatenate fragments. 704 */ 705 q = fp->ipq_fragq.lh_first; 706 ip = q->ipqe_ip; 707 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 708 ipstat.ips_toolong++; 709 ip_freef(fp); 710 return (0); 711 } 712 m = q->ipqe_m; 713 t = m->m_next; 714 m->m_next = 0; 715 m_cat(m, t); 716 nq = q->ipqe_q.le_next; 717 pool_put(&ipqent_pool, q); 718 for (q = nq; q != NULL; q = nq) { 719 t = q->ipqe_m; 720 nq = q->ipqe_q.le_next; 721 pool_put(&ipqent_pool, q); 722 m_cat(m, t); 723 } 724 725 /* 726 * Create header for new ip packet by 727 * modifying header of first packet; 728 * dequeue and discard fragment reassembly header. 729 * Make header visible. 730 */ 731 ip->ip_len = next; 732 ip->ip_src = fp->ipq_src; 733 ip->ip_dst = fp->ipq_dst; 734 LIST_REMOVE(fp, ipq_q); 735 FREE(fp, M_FTABLE); 736 m->m_len += (ip->ip_hl << 2); 737 m->m_data -= (ip->ip_hl << 2); 738 /* some debugging cruft by sklower, below, will go away soon */ 739 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 740 register int plen = 0; 741 for (t = m; t; t = t->m_next) 742 plen += t->m_len; 743 m->m_pkthdr.len = plen; 744 } 745 return (m); 746 747 dropfrag: 748 ipstat.ips_fragdropped++; 749 m_freem(m); 750 pool_put(&ipqent_pool, ipqe); 751 return (0); 752 } 753 754 /* 755 * Free a fragment reassembly header and all 756 * associated datagrams. 757 */ 758 void 759 ip_freef(fp) 760 struct ipq *fp; 761 { 762 register struct ipqent *q, *p; 763 764 IPQ_LOCK_CHECK(); 765 766 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 767 p = q->ipqe_q.le_next; 768 m_freem(q->ipqe_m); 769 LIST_REMOVE(q, ipqe_q); 770 pool_put(&ipqent_pool, q); 771 } 772 LIST_REMOVE(fp, ipq_q); 773 FREE(fp, M_FTABLE); 774 } 775 776 /* 777 * IP timer processing; 778 * if a timer expires on a reassembly 779 * queue, discard it. 780 */ 781 void 782 ip_slowtimo() 783 { 784 register struct ipq *fp, *nfp; 785 int s = splsoftnet(); 786 787 IPQ_LOCK(); 788 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 789 nfp = fp->ipq_q.le_next; 790 if (--fp->ipq_ttl == 0) { 791 ipstat.ips_fragtimeout++; 792 ip_freef(fp); 793 } 794 } 795 IPQ_UNLOCK(); 796 #ifdef GATEWAY 797 ipflow_slowtimo(); 798 #endif 799 splx(s); 800 } 801 802 /* 803 * Drain off all datagram fragments. 804 */ 805 void 806 ip_drain() 807 { 808 809 /* 810 * We may be called from a device's interrupt context. If 811 * the ipq is already busy, just bail out now. 812 */ 813 if (ipq_lock_try() == 0) 814 return; 815 816 while (ipq.lh_first != NULL) { 817 ipstat.ips_fragdropped++; 818 ip_freef(ipq.lh_first); 819 } 820 821 IPQ_UNLOCK(); 822 } 823 824 /* 825 * Do option processing on a datagram, 826 * possibly discarding it if bad options are encountered, 827 * or forwarding it if source-routed. 828 * Returns 1 if packet has been forwarded/freed, 829 * 0 if the packet should be processed further. 830 */ 831 int 832 ip_dooptions(m) 833 struct mbuf *m; 834 { 835 register struct ip *ip = mtod(m, struct ip *); 836 register u_char *cp; 837 register struct ip_timestamp *ipt; 838 register struct in_ifaddr *ia; 839 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 840 struct in_addr *sin, dst; 841 n_time ntime; 842 843 dst = ip->ip_dst; 844 cp = (u_char *)(ip + 1); 845 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 846 for (; cnt > 0; cnt -= optlen, cp += optlen) { 847 opt = cp[IPOPT_OPTVAL]; 848 if (opt == IPOPT_EOL) 849 break; 850 if (opt == IPOPT_NOP) 851 optlen = 1; 852 else { 853 optlen = cp[IPOPT_OLEN]; 854 if (optlen <= 0 || optlen > cnt) { 855 code = &cp[IPOPT_OLEN] - (u_char *)ip; 856 goto bad; 857 } 858 } 859 switch (opt) { 860 861 default: 862 break; 863 864 /* 865 * Source routing with record. 866 * Find interface with current destination address. 867 * If none on this machine then drop if strictly routed, 868 * or do nothing if loosely routed. 869 * Record interface address and bring up next address 870 * component. If strictly routed make sure next 871 * address is on directly accessible net. 872 */ 873 case IPOPT_LSRR: 874 case IPOPT_SSRR: 875 if (ip_allowsrcrt == 0) { 876 type = ICMP_UNREACH; 877 code = ICMP_UNREACH_NET_PROHIB; 878 goto bad; 879 } 880 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 881 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 882 goto bad; 883 } 884 ipaddr.sin_addr = ip->ip_dst; 885 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 886 if (ia == 0) { 887 if (opt == IPOPT_SSRR) { 888 type = ICMP_UNREACH; 889 code = ICMP_UNREACH_SRCFAIL; 890 goto bad; 891 } 892 /* 893 * Loose routing, and not at next destination 894 * yet; nothing to do except forward. 895 */ 896 break; 897 } 898 off--; /* 0 origin */ 899 if (off > optlen - sizeof(struct in_addr)) { 900 /* 901 * End of source route. Should be for us. 902 */ 903 save_rte(cp, ip->ip_src); 904 break; 905 } 906 /* 907 * locate outgoing interface 908 */ 909 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 910 sizeof(ipaddr.sin_addr)); 911 if (opt == IPOPT_SSRR) { 912 #define INA struct in_ifaddr * 913 #define SA struct sockaddr * 914 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 915 } else 916 ia = ip_rtaddr(ipaddr.sin_addr); 917 if (ia == 0) { 918 type = ICMP_UNREACH; 919 code = ICMP_UNREACH_SRCFAIL; 920 goto bad; 921 } 922 ip->ip_dst = ipaddr.sin_addr; 923 bcopy((caddr_t)&ia->ia_addr.sin_addr, 924 (caddr_t)(cp + off), sizeof(struct in_addr)); 925 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 926 /* 927 * Let ip_intr's mcast routing check handle mcast pkts 928 */ 929 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 930 break; 931 932 case IPOPT_RR: 933 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 934 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 935 goto bad; 936 } 937 /* 938 * If no space remains, ignore. 939 */ 940 off--; /* 0 origin */ 941 if (off > optlen - sizeof(struct in_addr)) 942 break; 943 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 944 sizeof(ipaddr.sin_addr)); 945 /* 946 * locate outgoing interface; if we're the destination, 947 * use the incoming interface (should be same). 948 */ 949 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 950 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 951 type = ICMP_UNREACH; 952 code = ICMP_UNREACH_HOST; 953 goto bad; 954 } 955 bcopy((caddr_t)&ia->ia_addr.sin_addr, 956 (caddr_t)(cp + off), sizeof(struct in_addr)); 957 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 958 break; 959 960 case IPOPT_TS: 961 code = cp - (u_char *)ip; 962 ipt = (struct ip_timestamp *)cp; 963 if (ipt->ipt_len < 5) 964 goto bad; 965 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 966 if (++ipt->ipt_oflw == 0) 967 goto bad; 968 break; 969 } 970 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 971 switch (ipt->ipt_flg) { 972 973 case IPOPT_TS_TSONLY: 974 break; 975 976 case IPOPT_TS_TSANDADDR: 977 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 978 sizeof(struct in_addr) > ipt->ipt_len) 979 goto bad; 980 ipaddr.sin_addr = dst; 981 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 982 m->m_pkthdr.rcvif); 983 if (ia == 0) 984 continue; 985 bcopy((caddr_t)&ia->ia_addr.sin_addr, 986 (caddr_t)sin, sizeof(struct in_addr)); 987 ipt->ipt_ptr += sizeof(struct in_addr); 988 break; 989 990 case IPOPT_TS_PRESPEC: 991 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 992 sizeof(struct in_addr) > ipt->ipt_len) 993 goto bad; 994 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 995 sizeof(struct in_addr)); 996 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 997 continue; 998 ipt->ipt_ptr += sizeof(struct in_addr); 999 break; 1000 1001 default: 1002 goto bad; 1003 } 1004 ntime = iptime(); 1005 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1006 sizeof(n_time)); 1007 ipt->ipt_ptr += sizeof(n_time); 1008 } 1009 } 1010 if (forward) { 1011 if (ip_forwsrcrt == 0) { 1012 type = ICMP_UNREACH; 1013 code = ICMP_UNREACH_SRCFAIL; 1014 goto bad; 1015 } 1016 ip_forward(m, 1); 1017 return (1); 1018 } 1019 return (0); 1020 bad: 1021 icmp_error(m, type, code, 0, 0); 1022 ipstat.ips_badoptions++; 1023 return (1); 1024 } 1025 1026 /* 1027 * Given address of next destination (final or next hop), 1028 * return internet address info of interface to be used to get there. 1029 */ 1030 struct in_ifaddr * 1031 ip_rtaddr(dst) 1032 struct in_addr dst; 1033 { 1034 register struct sockaddr_in *sin; 1035 1036 sin = satosin(&ipforward_rt.ro_dst); 1037 1038 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1039 if (ipforward_rt.ro_rt) { 1040 RTFREE(ipforward_rt.ro_rt); 1041 ipforward_rt.ro_rt = 0; 1042 } 1043 sin->sin_family = AF_INET; 1044 sin->sin_len = sizeof(*sin); 1045 sin->sin_addr = dst; 1046 1047 rtalloc(&ipforward_rt); 1048 } 1049 if (ipforward_rt.ro_rt == 0) 1050 return ((struct in_ifaddr *)0); 1051 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1052 } 1053 1054 /* 1055 * Save incoming source route for use in replies, 1056 * to be picked up later by ip_srcroute if the receiver is interested. 1057 */ 1058 void 1059 save_rte(option, dst) 1060 u_char *option; 1061 struct in_addr dst; 1062 { 1063 unsigned olen; 1064 1065 olen = option[IPOPT_OLEN]; 1066 #ifdef DIAGNOSTIC 1067 if (ipprintfs) 1068 printf("save_rte: olen %d\n", olen); 1069 #endif 1070 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1071 return; 1072 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1073 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1074 ip_srcrt.dst = dst; 1075 } 1076 1077 /* 1078 * Retrieve incoming source route for use in replies, 1079 * in the same form used by setsockopt. 1080 * The first hop is placed before the options, will be removed later. 1081 */ 1082 struct mbuf * 1083 ip_srcroute() 1084 { 1085 register struct in_addr *p, *q; 1086 register struct mbuf *m; 1087 1088 if (ip_nhops == 0) 1089 return ((struct mbuf *)0); 1090 m = m_get(M_DONTWAIT, MT_SOOPTS); 1091 if (m == 0) 1092 return ((struct mbuf *)0); 1093 1094 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1095 1096 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1097 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1098 OPTSIZ; 1099 #ifdef DIAGNOSTIC 1100 if (ipprintfs) 1101 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1102 #endif 1103 1104 /* 1105 * First save first hop for return route 1106 */ 1107 p = &ip_srcrt.route[ip_nhops - 1]; 1108 *(mtod(m, struct in_addr *)) = *p--; 1109 #ifdef DIAGNOSTIC 1110 if (ipprintfs) 1111 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1112 #endif 1113 1114 /* 1115 * Copy option fields and padding (nop) to mbuf. 1116 */ 1117 ip_srcrt.nop = IPOPT_NOP; 1118 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1119 bcopy((caddr_t)&ip_srcrt.nop, 1120 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1121 q = (struct in_addr *)(mtod(m, caddr_t) + 1122 sizeof(struct in_addr) + OPTSIZ); 1123 #undef OPTSIZ 1124 /* 1125 * Record return path as an IP source route, 1126 * reversing the path (pointers are now aligned). 1127 */ 1128 while (p >= ip_srcrt.route) { 1129 #ifdef DIAGNOSTIC 1130 if (ipprintfs) 1131 printf(" %x", ntohl(q->s_addr)); 1132 #endif 1133 *q++ = *p--; 1134 } 1135 /* 1136 * Last hop goes to final destination. 1137 */ 1138 *q = ip_srcrt.dst; 1139 #ifdef DIAGNOSTIC 1140 if (ipprintfs) 1141 printf(" %x\n", ntohl(q->s_addr)); 1142 #endif 1143 return (m); 1144 } 1145 1146 /* 1147 * Strip out IP options, at higher 1148 * level protocol in the kernel. 1149 * Second argument is buffer to which options 1150 * will be moved, and return value is their length. 1151 * XXX should be deleted; last arg currently ignored. 1152 */ 1153 void 1154 ip_stripoptions(m, mopt) 1155 register struct mbuf *m; 1156 struct mbuf *mopt; 1157 { 1158 register int i; 1159 struct ip *ip = mtod(m, struct ip *); 1160 register caddr_t opts; 1161 int olen; 1162 1163 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1164 opts = (caddr_t)(ip + 1); 1165 i = m->m_len - (sizeof (struct ip) + olen); 1166 bcopy(opts + olen, opts, (unsigned)i); 1167 m->m_len -= olen; 1168 if (m->m_flags & M_PKTHDR) 1169 m->m_pkthdr.len -= olen; 1170 ip->ip_len -= olen; 1171 ip->ip_hl = sizeof (struct ip) >> 2; 1172 } 1173 1174 int inetctlerrmap[PRC_NCMDS] = { 1175 0, 0, 0, 0, 1176 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1177 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1178 EMSGSIZE, EHOSTUNREACH, 0, 0, 1179 0, 0, 0, 0, 1180 ENOPROTOOPT 1181 }; 1182 1183 /* 1184 * Forward a packet. If some error occurs return the sender 1185 * an icmp packet. Note we can't always generate a meaningful 1186 * icmp message because icmp doesn't have a large enough repertoire 1187 * of codes and types. 1188 * 1189 * If not forwarding, just drop the packet. This could be confusing 1190 * if ipforwarding was zero but some routing protocol was advancing 1191 * us as a gateway to somewhere. However, we must let the routing 1192 * protocol deal with that. 1193 * 1194 * The srcrt parameter indicates whether the packet is being forwarded 1195 * via a source route. 1196 */ 1197 void 1198 ip_forward(m, srcrt) 1199 struct mbuf *m; 1200 int srcrt; 1201 { 1202 register struct ip *ip = mtod(m, struct ip *); 1203 register struct sockaddr_in *sin; 1204 register struct rtentry *rt; 1205 int error, type = 0, code = 0; 1206 struct mbuf *mcopy; 1207 n_long dest; 1208 struct ifnet *destifp; 1209 1210 dest = 0; 1211 #ifdef DIAGNOSTIC 1212 if (ipprintfs) 1213 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1214 ntohl(ip->ip_src.s_addr), 1215 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1216 #endif 1217 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1218 ipstat.ips_cantforward++; 1219 m_freem(m); 1220 return; 1221 } 1222 if (ip->ip_ttl <= IPTTLDEC) { 1223 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1224 return; 1225 } 1226 ip->ip_ttl -= IPTTLDEC; 1227 1228 sin = satosin(&ipforward_rt.ro_dst); 1229 if ((rt = ipforward_rt.ro_rt) == 0 || 1230 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1231 if (ipforward_rt.ro_rt) { 1232 RTFREE(ipforward_rt.ro_rt); 1233 ipforward_rt.ro_rt = 0; 1234 } 1235 sin->sin_family = AF_INET; 1236 sin->sin_len = sizeof(struct sockaddr_in); 1237 sin->sin_addr = ip->ip_dst; 1238 1239 rtalloc(&ipforward_rt); 1240 if (ipforward_rt.ro_rt == 0) { 1241 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1242 return; 1243 } 1244 rt = ipforward_rt.ro_rt; 1245 } 1246 1247 /* 1248 * Save at most 68 bytes of the packet in case 1249 * we need to generate an ICMP message to the src. 1250 */ 1251 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1252 1253 /* 1254 * If forwarding packet using same interface that it came in on, 1255 * perhaps should send a redirect to sender to shortcut a hop. 1256 * Only send redirect if source is sending directly to us, 1257 * and if packet was not source routed (or has any options). 1258 * Also, don't send redirect if forwarding using a default route 1259 * or a route modified by a redirect. 1260 */ 1261 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1262 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1263 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1264 ipsendredirects && !srcrt) { 1265 if (rt->rt_ifa && 1266 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1267 ifatoia(rt->rt_ifa)->ia_subnet) { 1268 if (rt->rt_flags & RTF_GATEWAY) 1269 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1270 else 1271 dest = ip->ip_dst.s_addr; 1272 /* 1273 * Router requirements says to only send host 1274 * redirects. 1275 */ 1276 type = ICMP_REDIRECT; 1277 code = ICMP_REDIRECT_HOST; 1278 #ifdef DIAGNOSTIC 1279 if (ipprintfs) 1280 printf("redirect (%d) to %x\n", code, 1281 (u_int32_t)dest); 1282 #endif 1283 } 1284 } 1285 1286 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1287 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1288 if (error) 1289 ipstat.ips_cantforward++; 1290 else { 1291 ipstat.ips_forward++; 1292 if (type) 1293 ipstat.ips_redirectsent++; 1294 else { 1295 if (mcopy) { 1296 #ifdef GATEWAY 1297 if (mcopy->m_flags & M_CANFASTFWD) 1298 ipflow_create(&ipforward_rt, mcopy); 1299 #endif 1300 m_freem(mcopy); 1301 } 1302 return; 1303 } 1304 } 1305 if (mcopy == NULL) 1306 return; 1307 destifp = NULL; 1308 1309 switch (error) { 1310 1311 case 0: /* forwarded, but need redirect */ 1312 /* type, code set above */ 1313 break; 1314 1315 case ENETUNREACH: /* shouldn't happen, checked above */ 1316 case EHOSTUNREACH: 1317 case ENETDOWN: 1318 case EHOSTDOWN: 1319 default: 1320 type = ICMP_UNREACH; 1321 code = ICMP_UNREACH_HOST; 1322 break; 1323 1324 case EMSGSIZE: 1325 type = ICMP_UNREACH; 1326 code = ICMP_UNREACH_NEEDFRAG; 1327 if (ipforward_rt.ro_rt) 1328 destifp = ipforward_rt.ro_rt->rt_ifp; 1329 ipstat.ips_cantfrag++; 1330 break; 1331 1332 case ENOBUFS: 1333 type = ICMP_SOURCEQUENCH; 1334 code = 0; 1335 break; 1336 } 1337 icmp_error(mcopy, type, code, dest, destifp); 1338 } 1339 1340 void 1341 ip_savecontrol(inp, mp, ip, m) 1342 register struct inpcb *inp; 1343 register struct mbuf **mp; 1344 register struct ip *ip; 1345 register struct mbuf *m; 1346 { 1347 1348 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1349 struct timeval tv; 1350 1351 microtime(&tv); 1352 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1353 SCM_TIMESTAMP, SOL_SOCKET); 1354 if (*mp) 1355 mp = &(*mp)->m_next; 1356 } 1357 if (inp->inp_flags & INP_RECVDSTADDR) { 1358 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1359 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1360 if (*mp) 1361 mp = &(*mp)->m_next; 1362 } 1363 #ifdef notyet 1364 /* 1365 * XXX 1366 * Moving these out of udp_input() made them even more broken 1367 * than they already were. 1368 * - fenner@parc.xerox.com 1369 */ 1370 /* options were tossed already */ 1371 if (inp->inp_flags & INP_RECVOPTS) { 1372 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1373 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1374 if (*mp) 1375 mp = &(*mp)->m_next; 1376 } 1377 /* ip_srcroute doesn't do what we want here, need to fix */ 1378 if (inp->inp_flags & INP_RECVRETOPTS) { 1379 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1380 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1381 if (*mp) 1382 mp = &(*mp)->m_next; 1383 } 1384 #endif 1385 if (inp->inp_flags & INP_RECVIF) { 1386 struct sockaddr_dl sdl; 1387 1388 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1389 sdl.sdl_family = AF_LINK; 1390 sdl.sdl_index = m->m_pkthdr.rcvif ? 1391 m->m_pkthdr.rcvif->if_index : 0; 1392 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1393 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1394 IP_RECVIF, IPPROTO_IP); 1395 if (*mp) 1396 mp = &(*mp)->m_next; 1397 } 1398 } 1399 1400 int 1401 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1402 int *name; 1403 u_int namelen; 1404 void *oldp; 1405 size_t *oldlenp; 1406 void *newp; 1407 size_t newlen; 1408 { 1409 extern int subnetsarelocal; 1410 1411 int error, old; 1412 1413 /* All sysctl names at this level are terminal. */ 1414 if (namelen != 1) 1415 return (ENOTDIR); 1416 1417 switch (name[0]) { 1418 case IPCTL_FORWARDING: 1419 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1420 case IPCTL_SENDREDIRECTS: 1421 return (sysctl_int(oldp, oldlenp, newp, newlen, 1422 &ipsendredirects)); 1423 case IPCTL_DEFTTL: 1424 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1425 #ifdef notyet 1426 case IPCTL_DEFMTU: 1427 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1428 #endif 1429 case IPCTL_FORWSRCRT: 1430 /* Don't allow this to change in a secure environment. */ 1431 if (securelevel > 0) 1432 return (sysctl_rdint(oldp, oldlenp, newp, 1433 ip_forwsrcrt)); 1434 else 1435 return (sysctl_int(oldp, oldlenp, newp, newlen, 1436 &ip_forwsrcrt)); 1437 case IPCTL_DIRECTEDBCAST: 1438 return (sysctl_int(oldp, oldlenp, newp, newlen, 1439 &ip_directedbcast)); 1440 case IPCTL_ALLOWSRCRT: 1441 return (sysctl_int(oldp, oldlenp, newp, newlen, 1442 &ip_allowsrcrt)); 1443 case IPCTL_SUBNETSARELOCAL: 1444 return (sysctl_int(oldp, oldlenp, newp, newlen, 1445 &subnetsarelocal)); 1446 case IPCTL_MTUDISC: 1447 error = sysctl_int(oldp, oldlenp, newp, newlen, 1448 &ip_mtudisc); 1449 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1450 ip_mtudisc_timeout_q = 1451 rt_timer_queue_create(ip_mtudisc_timeout); 1452 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1453 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1454 ip_mtudisc_timeout_q = NULL; 1455 } 1456 return error; 1457 case IPCTL_ANONPORTMIN: 1458 old = anonportmin; 1459 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1460 if (anonportmin >= anonportmax || anonportmin > 65535 1461 #ifndef IPNOPRIVPORTS 1462 || anonportmin < IPPORT_RESERVED 1463 #endif 1464 ) { 1465 anonportmin = old; 1466 return (EINVAL); 1467 } 1468 return (error); 1469 case IPCTL_ANONPORTMAX: 1470 old = anonportmax; 1471 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1472 if (anonportmin >= anonportmax || anonportmax > 65535 1473 #ifndef IPNOPRIVPORTS 1474 || anonportmax < IPPORT_RESERVED 1475 #endif 1476 ) { 1477 anonportmax = old; 1478 return (EINVAL); 1479 } 1480 return (error); 1481 case IPCTL_MTUDISCTIMEOUT: 1482 error = sysctl_int(oldp, oldlenp, newp, newlen, 1483 &ip_mtudisc_timeout); 1484 if (ip_mtudisc_timeout_q != NULL) 1485 rt_timer_queue_change(ip_mtudisc_timeout_q, 1486 ip_mtudisc_timeout); 1487 return (error); 1488 #ifdef GATEWAY 1489 case IPCTL_MAXFLOWS: 1490 { 1491 int s; 1492 1493 error = sysctl_int(oldp, oldlenp, newp, newlen, 1494 &ip_maxflows); 1495 s = splsoftnet(); 1496 ipflow_reap(0); 1497 splx(s); 1498 return (error); 1499 } 1500 #endif 1501 default: 1502 return (EOPNOTSUPP); 1503 } 1504 /* NOTREACHED */ 1505 } 1506