1 /* $NetBSD: ip_input.c,v 1.77 1999/01/11 22:35:06 thorpej 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 ((ip->ip_sum = 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_id); 353 NTOHS(ip->ip_off); 354 len = ip->ip_len; 355 356 /* 357 * Check that the amount of data in the buffers 358 * is as at least much as the IP header would have us expect. 359 * Trim mbufs if longer than we expect. 360 * Drop packet if shorter than we expect. 361 */ 362 if (m->m_pkthdr.len < len) { 363 ipstat.ips_tooshort++; 364 goto bad; 365 } 366 if (m->m_pkthdr.len > len) { 367 if (m->m_len == m->m_pkthdr.len) { 368 m->m_len = len; 369 m->m_pkthdr.len = len; 370 } else 371 m_adj(m, len - m->m_pkthdr.len); 372 } 373 374 /* 375 * Assume that we can create a fast-forward IP flow entry 376 * based on this packet. 377 */ 378 m->m_flags |= M_CANFASTFWD; 379 380 #ifdef PFIL_HOOKS 381 /* 382 * Run through list of hooks for input packets. If there are any 383 * filters which require that additional packets in the flow are 384 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 385 * Note that filters must _never_ set this flag, as another filter 386 * in the list may have previously cleared it. 387 */ 388 m0 = m; 389 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next) 390 if (pfh->pfil_func) { 391 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0); 392 if (rv) 393 goto next; 394 m = m0; 395 if (m == NULL) 396 goto next; 397 ip = mtod(m, struct ip *); 398 } 399 #endif /* PFIL_HOOKS */ 400 401 /* 402 * Process options and, if not destined for us, 403 * ship it on. ip_dooptions returns 1 when an 404 * error was detected (causing an icmp message 405 * to be sent and the original packet to be freed). 406 */ 407 ip_nhops = 0; /* for source routed packets */ 408 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 409 goto next; 410 411 /* 412 * Check our list of addresses, to see if the packet is for us. 413 */ 414 INADDR_TO_IA(ip->ip_dst, ia); 415 if (ia != NULL) goto ours; 416 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 417 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 418 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 419 if (ifa->ifa_addr->sa_family != AF_INET) continue; 420 ia = ifatoia(ifa); 421 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 422 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 423 /* 424 * Look for all-0's host part (old broadcast addr), 425 * either for subnet or net. 426 */ 427 ip->ip_dst.s_addr == ia->ia_subnet || 428 ip->ip_dst.s_addr == ia->ia_net) 429 goto ours; 430 /* 431 * An interface with IP address zero accepts 432 * all packets that arrive on that interface. 433 */ 434 if (in_nullhost(ia->ia_addr.sin_addr)) 435 goto ours; 436 } 437 } 438 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 439 struct in_multi *inm; 440 #ifdef MROUTING 441 extern struct socket *ip_mrouter; 442 443 if (m->m_flags & M_EXT) { 444 if ((m = m_pullup(m, hlen)) == 0) { 445 ipstat.ips_toosmall++; 446 goto next; 447 } 448 ip = mtod(m, struct ip *); 449 } 450 451 if (ip_mrouter) { 452 /* 453 * If we are acting as a multicast router, all 454 * incoming multicast packets are passed to the 455 * kernel-level multicast forwarding function. 456 * The packet is returned (relatively) intact; if 457 * ip_mforward() returns a non-zero value, the packet 458 * must be discarded, else it may be accepted below. 459 * 460 * (The IP ident field is put in the same byte order 461 * as expected when ip_mforward() is called from 462 * ip_output().) 463 */ 464 ip->ip_id = htons(ip->ip_id); 465 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 466 ipstat.ips_cantforward++; 467 m_freem(m); 468 goto next; 469 } 470 ip->ip_id = ntohs(ip->ip_id); 471 472 /* 473 * The process-level routing demon needs to receive 474 * all multicast IGMP packets, whether or not this 475 * host belongs to their destination groups. 476 */ 477 if (ip->ip_p == IPPROTO_IGMP) 478 goto ours; 479 ipstat.ips_forward++; 480 } 481 #endif 482 /* 483 * See if we belong to the destination multicast group on the 484 * arrival interface. 485 */ 486 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 487 if (inm == NULL) { 488 ipstat.ips_cantforward++; 489 m_freem(m); 490 goto next; 491 } 492 goto ours; 493 } 494 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 495 in_nullhost(ip->ip_dst)) 496 goto ours; 497 498 /* 499 * Not for us; forward if possible and desirable. 500 */ 501 if (ipforwarding == 0) { 502 ipstat.ips_cantforward++; 503 m_freem(m); 504 } else 505 ip_forward(m, 0); 506 goto next; 507 508 ours: 509 /* 510 * If offset or IP_MF are set, must reassemble. 511 * Otherwise, nothing need be done. 512 * (We could look in the reassembly queue to see 513 * if the packet was previously fragmented, 514 * but it's not worth the time; just let them time out.) 515 */ 516 if (ip->ip_off & ~(IP_DF|IP_RF)) { 517 /* 518 * Look for queue of fragments 519 * of this datagram. 520 */ 521 IPQ_LOCK(); 522 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 523 if (ip->ip_id == fp->ipq_id && 524 in_hosteq(ip->ip_src, fp->ipq_src) && 525 in_hosteq(ip->ip_dst, fp->ipq_dst) && 526 ip->ip_p == fp->ipq_p) 527 goto found; 528 fp = 0; 529 found: 530 531 /* 532 * Adjust ip_len to not reflect header, 533 * set ipqe_mff if more fragments are expected, 534 * convert offset of this to bytes. 535 */ 536 ip->ip_len -= hlen; 537 mff = (ip->ip_off & IP_MF) != 0; 538 if (mff) { 539 /* 540 * Make sure that fragments have a data length 541 * that's a non-zero multiple of 8 bytes. 542 */ 543 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 544 ipstat.ips_badfrags++; 545 IPQ_UNLOCK(); 546 goto bad; 547 } 548 } 549 ip->ip_off <<= 3; 550 551 /* 552 * If datagram marked as having more fragments 553 * or if this is not the first fragment, 554 * attempt reassembly; if it succeeds, proceed. 555 */ 556 if (mff || ip->ip_off) { 557 ipstat.ips_fragments++; 558 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 559 if (ipqe == NULL) { 560 ipstat.ips_rcvmemdrop++; 561 IPQ_UNLOCK(); 562 goto bad; 563 } 564 ipqe->ipqe_mff = mff; 565 ipqe->ipqe_m = m; 566 ipqe->ipqe_ip = ip; 567 m = ip_reass(ipqe, fp); 568 if (m == 0) { 569 IPQ_UNLOCK(); 570 goto next; 571 } 572 ipstat.ips_reassembled++; 573 ip = mtod(m, struct ip *); 574 hlen = ip->ip_hl << 2; 575 } else 576 if (fp) 577 ip_freef(fp); 578 IPQ_UNLOCK(); 579 } else 580 ip->ip_len -= hlen; 581 582 /* 583 * Switch out to protocol's input routine. 584 */ 585 ipstat.ips_delivered++; 586 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 587 goto next; 588 bad: 589 m_freem(m); 590 goto next; 591 } 592 593 /* 594 * Take incoming datagram fragment and try to 595 * reassemble it into whole datagram. If a chain for 596 * reassembly of this datagram already exists, then it 597 * is given as fp; otherwise have to make a chain. 598 */ 599 struct mbuf * 600 ip_reass(ipqe, fp) 601 register struct ipqent *ipqe; 602 register struct ipq *fp; 603 { 604 register struct mbuf *m = ipqe->ipqe_m; 605 register struct ipqent *nq, *p, *q; 606 struct ip *ip; 607 struct mbuf *t; 608 int hlen = ipqe->ipqe_ip->ip_hl << 2; 609 int i, next; 610 611 IPQ_LOCK_CHECK(); 612 613 /* 614 * Presence of header sizes in mbufs 615 * would confuse code below. 616 */ 617 m->m_data += hlen; 618 m->m_len -= hlen; 619 620 /* 621 * If first fragment to arrive, create a reassembly queue. 622 */ 623 if (fp == 0) { 624 MALLOC(fp, struct ipq *, sizeof (struct ipq), 625 M_FTABLE, M_NOWAIT); 626 if (fp == NULL) 627 goto dropfrag; 628 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 629 fp->ipq_ttl = IPFRAGTTL; 630 fp->ipq_p = ipqe->ipqe_ip->ip_p; 631 fp->ipq_id = ipqe->ipqe_ip->ip_id; 632 LIST_INIT(&fp->ipq_fragq); 633 fp->ipq_src = ipqe->ipqe_ip->ip_src; 634 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 635 p = NULL; 636 goto insert; 637 } 638 639 /* 640 * Find a segment which begins after this one does. 641 */ 642 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 643 p = q, q = q->ipqe_q.le_next) 644 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 645 break; 646 647 /* 648 * If there is a preceding segment, it may provide some of 649 * our data already. If so, drop the data from the incoming 650 * segment. If it provides all of our data, drop us. 651 */ 652 if (p != NULL) { 653 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 654 ipqe->ipqe_ip->ip_off; 655 if (i > 0) { 656 if (i >= ipqe->ipqe_ip->ip_len) 657 goto dropfrag; 658 m_adj(ipqe->ipqe_m, i); 659 ipqe->ipqe_ip->ip_off += i; 660 ipqe->ipqe_ip->ip_len -= i; 661 } 662 } 663 664 /* 665 * While we overlap succeeding segments trim them or, 666 * if they are completely covered, dequeue them. 667 */ 668 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 669 q->ipqe_ip->ip_off; q = nq) { 670 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 671 q->ipqe_ip->ip_off; 672 if (i < q->ipqe_ip->ip_len) { 673 q->ipqe_ip->ip_len -= i; 674 q->ipqe_ip->ip_off += i; 675 m_adj(q->ipqe_m, i); 676 break; 677 } 678 nq = q->ipqe_q.le_next; 679 m_freem(q->ipqe_m); 680 LIST_REMOVE(q, ipqe_q); 681 pool_put(&ipqent_pool, q); 682 } 683 684 insert: 685 /* 686 * Stick new segment in its place; 687 * check for complete reassembly. 688 */ 689 if (p == NULL) { 690 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 691 } else { 692 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 693 } 694 next = 0; 695 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 696 p = q, q = q->ipqe_q.le_next) { 697 if (q->ipqe_ip->ip_off != next) 698 return (0); 699 next += q->ipqe_ip->ip_len; 700 } 701 if (p->ipqe_mff) 702 return (0); 703 704 /* 705 * Reassembly is complete. Check for a bogus message size and 706 * concatenate fragments. 707 */ 708 q = fp->ipq_fragq.lh_first; 709 ip = q->ipqe_ip; 710 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 711 ipstat.ips_toolong++; 712 ip_freef(fp); 713 return (0); 714 } 715 m = q->ipqe_m; 716 t = m->m_next; 717 m->m_next = 0; 718 m_cat(m, t); 719 nq = q->ipqe_q.le_next; 720 pool_put(&ipqent_pool, q); 721 for (q = nq; q != NULL; q = nq) { 722 t = q->ipqe_m; 723 nq = q->ipqe_q.le_next; 724 pool_put(&ipqent_pool, q); 725 m_cat(m, t); 726 } 727 728 /* 729 * Create header for new ip packet by 730 * modifying header of first packet; 731 * dequeue and discard fragment reassembly header. 732 * Make header visible. 733 */ 734 ip->ip_len = next; 735 ip->ip_src = fp->ipq_src; 736 ip->ip_dst = fp->ipq_dst; 737 LIST_REMOVE(fp, ipq_q); 738 FREE(fp, M_FTABLE); 739 m->m_len += (ip->ip_hl << 2); 740 m->m_data -= (ip->ip_hl << 2); 741 /* some debugging cruft by sklower, below, will go away soon */ 742 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 743 register int plen = 0; 744 for (t = m; t; t = t->m_next) 745 plen += t->m_len; 746 m->m_pkthdr.len = plen; 747 } 748 return (m); 749 750 dropfrag: 751 ipstat.ips_fragdropped++; 752 m_freem(m); 753 pool_put(&ipqent_pool, ipqe); 754 return (0); 755 } 756 757 /* 758 * Free a fragment reassembly header and all 759 * associated datagrams. 760 */ 761 void 762 ip_freef(fp) 763 struct ipq *fp; 764 { 765 register struct ipqent *q, *p; 766 767 IPQ_LOCK_CHECK(); 768 769 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 770 p = q->ipqe_q.le_next; 771 m_freem(q->ipqe_m); 772 LIST_REMOVE(q, ipqe_q); 773 pool_put(&ipqent_pool, q); 774 } 775 LIST_REMOVE(fp, ipq_q); 776 FREE(fp, M_FTABLE); 777 } 778 779 /* 780 * IP timer processing; 781 * if a timer expires on a reassembly 782 * queue, discard it. 783 */ 784 void 785 ip_slowtimo() 786 { 787 register struct ipq *fp, *nfp; 788 int s = splsoftnet(); 789 790 IPQ_LOCK(); 791 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 792 nfp = fp->ipq_q.le_next; 793 if (--fp->ipq_ttl == 0) { 794 ipstat.ips_fragtimeout++; 795 ip_freef(fp); 796 } 797 } 798 IPQ_UNLOCK(); 799 #ifdef GATEWAY 800 ipflow_slowtimo(); 801 #endif 802 splx(s); 803 } 804 805 /* 806 * Drain off all datagram fragments. 807 */ 808 void 809 ip_drain() 810 { 811 812 /* 813 * We may be called from a device's interrupt context. If 814 * the ipq is already busy, just bail out now. 815 */ 816 if (ipq_lock_try() == 0) 817 return; 818 819 while (ipq.lh_first != NULL) { 820 ipstat.ips_fragdropped++; 821 ip_freef(ipq.lh_first); 822 } 823 824 IPQ_UNLOCK(); 825 } 826 827 /* 828 * Do option processing on a datagram, 829 * possibly discarding it if bad options are encountered, 830 * or forwarding it if source-routed. 831 * Returns 1 if packet has been forwarded/freed, 832 * 0 if the packet should be processed further. 833 */ 834 int 835 ip_dooptions(m) 836 struct mbuf *m; 837 { 838 register struct ip *ip = mtod(m, struct ip *); 839 register u_char *cp; 840 register struct ip_timestamp *ipt; 841 register struct in_ifaddr *ia; 842 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 843 struct in_addr *sin, dst; 844 n_time ntime; 845 846 dst = ip->ip_dst; 847 cp = (u_char *)(ip + 1); 848 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 849 for (; cnt > 0; cnt -= optlen, cp += optlen) { 850 opt = cp[IPOPT_OPTVAL]; 851 if (opt == IPOPT_EOL) 852 break; 853 if (opt == IPOPT_NOP) 854 optlen = 1; 855 else { 856 optlen = cp[IPOPT_OLEN]; 857 if (optlen <= 0 || optlen > cnt) { 858 code = &cp[IPOPT_OLEN] - (u_char *)ip; 859 goto bad; 860 } 861 } 862 switch (opt) { 863 864 default: 865 break; 866 867 /* 868 * Source routing with record. 869 * Find interface with current destination address. 870 * If none on this machine then drop if strictly routed, 871 * or do nothing if loosely routed. 872 * Record interface address and bring up next address 873 * component. If strictly routed make sure next 874 * address is on directly accessible net. 875 */ 876 case IPOPT_LSRR: 877 case IPOPT_SSRR: 878 if (ip_allowsrcrt == 0) { 879 type = ICMP_UNREACH; 880 code = ICMP_UNREACH_NET_PROHIB; 881 goto bad; 882 } 883 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 884 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 885 goto bad; 886 } 887 ipaddr.sin_addr = ip->ip_dst; 888 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 889 if (ia == 0) { 890 if (opt == IPOPT_SSRR) { 891 type = ICMP_UNREACH; 892 code = ICMP_UNREACH_SRCFAIL; 893 goto bad; 894 } 895 /* 896 * Loose routing, and not at next destination 897 * yet; nothing to do except forward. 898 */ 899 break; 900 } 901 off--; /* 0 origin */ 902 if (off > optlen - sizeof(struct in_addr)) { 903 /* 904 * End of source route. Should be for us. 905 */ 906 save_rte(cp, ip->ip_src); 907 break; 908 } 909 /* 910 * locate outgoing interface 911 */ 912 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 913 sizeof(ipaddr.sin_addr)); 914 if (opt == IPOPT_SSRR) { 915 #define INA struct in_ifaddr * 916 #define SA struct sockaddr * 917 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 918 } else 919 ia = ip_rtaddr(ipaddr.sin_addr); 920 if (ia == 0) { 921 type = ICMP_UNREACH; 922 code = ICMP_UNREACH_SRCFAIL; 923 goto bad; 924 } 925 ip->ip_dst = ipaddr.sin_addr; 926 bcopy((caddr_t)&ia->ia_addr.sin_addr, 927 (caddr_t)(cp + off), sizeof(struct in_addr)); 928 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 929 /* 930 * Let ip_intr's mcast routing check handle mcast pkts 931 */ 932 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 933 break; 934 935 case IPOPT_RR: 936 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 937 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 938 goto bad; 939 } 940 /* 941 * If no space remains, ignore. 942 */ 943 off--; /* 0 origin */ 944 if (off > optlen - sizeof(struct in_addr)) 945 break; 946 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 947 sizeof(ipaddr.sin_addr)); 948 /* 949 * locate outgoing interface; if we're the destination, 950 * use the incoming interface (should be same). 951 */ 952 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 953 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 954 type = ICMP_UNREACH; 955 code = ICMP_UNREACH_HOST; 956 goto bad; 957 } 958 bcopy((caddr_t)&ia->ia_addr.sin_addr, 959 (caddr_t)(cp + off), sizeof(struct in_addr)); 960 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 961 break; 962 963 case IPOPT_TS: 964 code = cp - (u_char *)ip; 965 ipt = (struct ip_timestamp *)cp; 966 if (ipt->ipt_len < 5) 967 goto bad; 968 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 969 if (++ipt->ipt_oflw == 0) 970 goto bad; 971 break; 972 } 973 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 974 switch (ipt->ipt_flg) { 975 976 case IPOPT_TS_TSONLY: 977 break; 978 979 case IPOPT_TS_TSANDADDR: 980 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 981 sizeof(struct in_addr) > ipt->ipt_len) 982 goto bad; 983 ipaddr.sin_addr = dst; 984 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 985 m->m_pkthdr.rcvif); 986 if (ia == 0) 987 continue; 988 bcopy((caddr_t)&ia->ia_addr.sin_addr, 989 (caddr_t)sin, sizeof(struct in_addr)); 990 ipt->ipt_ptr += sizeof(struct in_addr); 991 break; 992 993 case IPOPT_TS_PRESPEC: 994 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 995 sizeof(struct in_addr) > ipt->ipt_len) 996 goto bad; 997 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 998 sizeof(struct in_addr)); 999 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1000 continue; 1001 ipt->ipt_ptr += sizeof(struct in_addr); 1002 break; 1003 1004 default: 1005 goto bad; 1006 } 1007 ntime = iptime(); 1008 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1009 sizeof(n_time)); 1010 ipt->ipt_ptr += sizeof(n_time); 1011 } 1012 } 1013 if (forward) { 1014 if (ip_forwsrcrt == 0) { 1015 type = ICMP_UNREACH; 1016 code = ICMP_UNREACH_SRCFAIL; 1017 goto bad; 1018 } 1019 ip_forward(m, 1); 1020 return (1); 1021 } 1022 return (0); 1023 bad: 1024 ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */ 1025 icmp_error(m, type, code, 0, 0); 1026 ipstat.ips_badoptions++; 1027 return (1); 1028 } 1029 1030 /* 1031 * Given address of next destination (final or next hop), 1032 * return internet address info of interface to be used to get there. 1033 */ 1034 struct in_ifaddr * 1035 ip_rtaddr(dst) 1036 struct in_addr dst; 1037 { 1038 register struct sockaddr_in *sin; 1039 1040 sin = satosin(&ipforward_rt.ro_dst); 1041 1042 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1043 if (ipforward_rt.ro_rt) { 1044 RTFREE(ipforward_rt.ro_rt); 1045 ipforward_rt.ro_rt = 0; 1046 } 1047 sin->sin_family = AF_INET; 1048 sin->sin_len = sizeof(*sin); 1049 sin->sin_addr = dst; 1050 1051 rtalloc(&ipforward_rt); 1052 } 1053 if (ipforward_rt.ro_rt == 0) 1054 return ((struct in_ifaddr *)0); 1055 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1056 } 1057 1058 /* 1059 * Save incoming source route for use in replies, 1060 * to be picked up later by ip_srcroute if the receiver is interested. 1061 */ 1062 void 1063 save_rte(option, dst) 1064 u_char *option; 1065 struct in_addr dst; 1066 { 1067 unsigned olen; 1068 1069 olen = option[IPOPT_OLEN]; 1070 #ifdef DIAGNOSTIC 1071 if (ipprintfs) 1072 printf("save_rte: olen %d\n", olen); 1073 #endif 1074 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1075 return; 1076 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1077 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1078 ip_srcrt.dst = dst; 1079 } 1080 1081 /* 1082 * Retrieve incoming source route for use in replies, 1083 * in the same form used by setsockopt. 1084 * The first hop is placed before the options, will be removed later. 1085 */ 1086 struct mbuf * 1087 ip_srcroute() 1088 { 1089 register struct in_addr *p, *q; 1090 register struct mbuf *m; 1091 1092 if (ip_nhops == 0) 1093 return ((struct mbuf *)0); 1094 m = m_get(M_DONTWAIT, MT_SOOPTS); 1095 if (m == 0) 1096 return ((struct mbuf *)0); 1097 1098 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1099 1100 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1101 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1102 OPTSIZ; 1103 #ifdef DIAGNOSTIC 1104 if (ipprintfs) 1105 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1106 #endif 1107 1108 /* 1109 * First save first hop for return route 1110 */ 1111 p = &ip_srcrt.route[ip_nhops - 1]; 1112 *(mtod(m, struct in_addr *)) = *p--; 1113 #ifdef DIAGNOSTIC 1114 if (ipprintfs) 1115 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1116 #endif 1117 1118 /* 1119 * Copy option fields and padding (nop) to mbuf. 1120 */ 1121 ip_srcrt.nop = IPOPT_NOP; 1122 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1123 bcopy((caddr_t)&ip_srcrt.nop, 1124 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1125 q = (struct in_addr *)(mtod(m, caddr_t) + 1126 sizeof(struct in_addr) + OPTSIZ); 1127 #undef OPTSIZ 1128 /* 1129 * Record return path as an IP source route, 1130 * reversing the path (pointers are now aligned). 1131 */ 1132 while (p >= ip_srcrt.route) { 1133 #ifdef DIAGNOSTIC 1134 if (ipprintfs) 1135 printf(" %x", ntohl(q->s_addr)); 1136 #endif 1137 *q++ = *p--; 1138 } 1139 /* 1140 * Last hop goes to final destination. 1141 */ 1142 *q = ip_srcrt.dst; 1143 #ifdef DIAGNOSTIC 1144 if (ipprintfs) 1145 printf(" %x\n", ntohl(q->s_addr)); 1146 #endif 1147 return (m); 1148 } 1149 1150 /* 1151 * Strip out IP options, at higher 1152 * level protocol in the kernel. 1153 * Second argument is buffer to which options 1154 * will be moved, and return value is their length. 1155 * XXX should be deleted; last arg currently ignored. 1156 */ 1157 void 1158 ip_stripoptions(m, mopt) 1159 register struct mbuf *m; 1160 struct mbuf *mopt; 1161 { 1162 register int i; 1163 struct ip *ip = mtod(m, struct ip *); 1164 register caddr_t opts; 1165 int olen; 1166 1167 olen = (ip->ip_hl<<2) - sizeof (struct ip); 1168 opts = (caddr_t)(ip + 1); 1169 i = m->m_len - (sizeof (struct ip) + olen); 1170 bcopy(opts + olen, opts, (unsigned)i); 1171 m->m_len -= olen; 1172 if (m->m_flags & M_PKTHDR) 1173 m->m_pkthdr.len -= olen; 1174 ip->ip_hl = sizeof(struct ip) >> 2; 1175 } 1176 1177 int inetctlerrmap[PRC_NCMDS] = { 1178 0, 0, 0, 0, 1179 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1180 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1181 EMSGSIZE, EHOSTUNREACH, 0, 0, 1182 0, 0, 0, 0, 1183 ENOPROTOOPT 1184 }; 1185 1186 /* 1187 * Forward a packet. If some error occurs return the sender 1188 * an icmp packet. Note we can't always generate a meaningful 1189 * icmp message because icmp doesn't have a large enough repertoire 1190 * of codes and types. 1191 * 1192 * If not forwarding, just drop the packet. This could be confusing 1193 * if ipforwarding was zero but some routing protocol was advancing 1194 * us as a gateway to somewhere. However, we must let the routing 1195 * protocol deal with that. 1196 * 1197 * The srcrt parameter indicates whether the packet is being forwarded 1198 * via a source route. 1199 */ 1200 void 1201 ip_forward(m, srcrt) 1202 struct mbuf *m; 1203 int srcrt; 1204 { 1205 register struct ip *ip = mtod(m, struct ip *); 1206 register struct sockaddr_in *sin; 1207 register struct rtentry *rt; 1208 int error, type = 0, code = 0; 1209 struct mbuf *mcopy; 1210 n_long dest; 1211 struct ifnet *destifp; 1212 1213 dest = 0; 1214 #ifdef DIAGNOSTIC 1215 if (ipprintfs) 1216 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1217 ntohl(ip->ip_src.s_addr), 1218 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1219 #endif 1220 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1221 ipstat.ips_cantforward++; 1222 m_freem(m); 1223 return; 1224 } 1225 if (ip->ip_ttl <= IPTTLDEC) { 1226 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1227 return; 1228 } 1229 ip->ip_ttl -= IPTTLDEC; 1230 1231 sin = satosin(&ipforward_rt.ro_dst); 1232 if ((rt = ipforward_rt.ro_rt) == 0 || 1233 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1234 if (ipforward_rt.ro_rt) { 1235 RTFREE(ipforward_rt.ro_rt); 1236 ipforward_rt.ro_rt = 0; 1237 } 1238 sin->sin_family = AF_INET; 1239 sin->sin_len = sizeof(struct sockaddr_in); 1240 sin->sin_addr = ip->ip_dst; 1241 1242 rtalloc(&ipforward_rt); 1243 if (ipforward_rt.ro_rt == 0) { 1244 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1245 return; 1246 } 1247 rt = ipforward_rt.ro_rt; 1248 } 1249 1250 /* 1251 * Save at most 68 bytes of the packet in case 1252 * we need to generate an ICMP message to the src. 1253 */ 1254 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1255 1256 /* 1257 * If forwarding packet using same interface that it came in on, 1258 * perhaps should send a redirect to sender to shortcut a hop. 1259 * Only send redirect if source is sending directly to us, 1260 * and if packet was not source routed (or has any options). 1261 * Also, don't send redirect if forwarding using a default route 1262 * or a route modified by a redirect. 1263 */ 1264 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1265 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1266 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1267 ipsendredirects && !srcrt) { 1268 if (rt->rt_ifa && 1269 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1270 ifatoia(rt->rt_ifa)->ia_subnet) { 1271 if (rt->rt_flags & RTF_GATEWAY) 1272 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1273 else 1274 dest = ip->ip_dst.s_addr; 1275 /* 1276 * Router requirements says to only send host 1277 * redirects. 1278 */ 1279 type = ICMP_REDIRECT; 1280 code = ICMP_REDIRECT_HOST; 1281 #ifdef DIAGNOSTIC 1282 if (ipprintfs) 1283 printf("redirect (%d) to %x\n", code, 1284 (u_int32_t)dest); 1285 #endif 1286 } 1287 } 1288 1289 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1290 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1291 if (error) 1292 ipstat.ips_cantforward++; 1293 else { 1294 ipstat.ips_forward++; 1295 if (type) 1296 ipstat.ips_redirectsent++; 1297 else { 1298 if (mcopy) { 1299 #ifdef GATEWAY 1300 if (mcopy->m_flags & M_CANFASTFWD) 1301 ipflow_create(&ipforward_rt, mcopy); 1302 #endif 1303 m_freem(mcopy); 1304 } 1305 return; 1306 } 1307 } 1308 if (mcopy == NULL) 1309 return; 1310 destifp = NULL; 1311 1312 switch (error) { 1313 1314 case 0: /* forwarded, but need redirect */ 1315 /* type, code set above */ 1316 break; 1317 1318 case ENETUNREACH: /* shouldn't happen, checked above */ 1319 case EHOSTUNREACH: 1320 case ENETDOWN: 1321 case EHOSTDOWN: 1322 default: 1323 type = ICMP_UNREACH; 1324 code = ICMP_UNREACH_HOST; 1325 break; 1326 1327 case EMSGSIZE: 1328 type = ICMP_UNREACH; 1329 code = ICMP_UNREACH_NEEDFRAG; 1330 if (ipforward_rt.ro_rt) 1331 destifp = ipforward_rt.ro_rt->rt_ifp; 1332 ipstat.ips_cantfrag++; 1333 break; 1334 1335 case ENOBUFS: 1336 type = ICMP_SOURCEQUENCH; 1337 code = 0; 1338 break; 1339 } 1340 icmp_error(mcopy, type, code, dest, destifp); 1341 } 1342 1343 void 1344 ip_savecontrol(inp, mp, ip, m) 1345 register struct inpcb *inp; 1346 register struct mbuf **mp; 1347 register struct ip *ip; 1348 register struct mbuf *m; 1349 { 1350 1351 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1352 struct timeval tv; 1353 1354 microtime(&tv); 1355 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1356 SCM_TIMESTAMP, SOL_SOCKET); 1357 if (*mp) 1358 mp = &(*mp)->m_next; 1359 } 1360 if (inp->inp_flags & INP_RECVDSTADDR) { 1361 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1362 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1363 if (*mp) 1364 mp = &(*mp)->m_next; 1365 } 1366 #ifdef notyet 1367 /* 1368 * XXX 1369 * Moving these out of udp_input() made them even more broken 1370 * than they already were. 1371 * - fenner@parc.xerox.com 1372 */ 1373 /* options were tossed already */ 1374 if (inp->inp_flags & INP_RECVOPTS) { 1375 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1376 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1377 if (*mp) 1378 mp = &(*mp)->m_next; 1379 } 1380 /* ip_srcroute doesn't do what we want here, need to fix */ 1381 if (inp->inp_flags & INP_RECVRETOPTS) { 1382 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1383 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1384 if (*mp) 1385 mp = &(*mp)->m_next; 1386 } 1387 #endif 1388 if (inp->inp_flags & INP_RECVIF) { 1389 struct sockaddr_dl sdl; 1390 1391 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1392 sdl.sdl_family = AF_LINK; 1393 sdl.sdl_index = m->m_pkthdr.rcvif ? 1394 m->m_pkthdr.rcvif->if_index : 0; 1395 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1396 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1397 IP_RECVIF, IPPROTO_IP); 1398 if (*mp) 1399 mp = &(*mp)->m_next; 1400 } 1401 } 1402 1403 int 1404 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1405 int *name; 1406 u_int namelen; 1407 void *oldp; 1408 size_t *oldlenp; 1409 void *newp; 1410 size_t newlen; 1411 { 1412 extern int subnetsarelocal; 1413 1414 int error, old; 1415 1416 /* All sysctl names at this level are terminal. */ 1417 if (namelen != 1) 1418 return (ENOTDIR); 1419 1420 switch (name[0]) { 1421 case IPCTL_FORWARDING: 1422 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1423 case IPCTL_SENDREDIRECTS: 1424 return (sysctl_int(oldp, oldlenp, newp, newlen, 1425 &ipsendredirects)); 1426 case IPCTL_DEFTTL: 1427 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1428 #ifdef notyet 1429 case IPCTL_DEFMTU: 1430 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1431 #endif 1432 case IPCTL_FORWSRCRT: 1433 /* Don't allow this to change in a secure environment. */ 1434 if (securelevel > 0) 1435 return (sysctl_rdint(oldp, oldlenp, newp, 1436 ip_forwsrcrt)); 1437 else 1438 return (sysctl_int(oldp, oldlenp, newp, newlen, 1439 &ip_forwsrcrt)); 1440 case IPCTL_DIRECTEDBCAST: 1441 return (sysctl_int(oldp, oldlenp, newp, newlen, 1442 &ip_directedbcast)); 1443 case IPCTL_ALLOWSRCRT: 1444 return (sysctl_int(oldp, oldlenp, newp, newlen, 1445 &ip_allowsrcrt)); 1446 case IPCTL_SUBNETSARELOCAL: 1447 return (sysctl_int(oldp, oldlenp, newp, newlen, 1448 &subnetsarelocal)); 1449 case IPCTL_MTUDISC: 1450 error = sysctl_int(oldp, oldlenp, newp, newlen, 1451 &ip_mtudisc); 1452 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1453 ip_mtudisc_timeout_q = 1454 rt_timer_queue_create(ip_mtudisc_timeout); 1455 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1456 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1457 ip_mtudisc_timeout_q = NULL; 1458 } 1459 return error; 1460 case IPCTL_ANONPORTMIN: 1461 old = anonportmin; 1462 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1463 if (anonportmin >= anonportmax || anonportmin > 65535 1464 #ifndef IPNOPRIVPORTS 1465 || anonportmin < IPPORT_RESERVED 1466 #endif 1467 ) { 1468 anonportmin = old; 1469 return (EINVAL); 1470 } 1471 return (error); 1472 case IPCTL_ANONPORTMAX: 1473 old = anonportmax; 1474 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1475 if (anonportmin >= anonportmax || anonportmax > 65535 1476 #ifndef IPNOPRIVPORTS 1477 || anonportmax < IPPORT_RESERVED 1478 #endif 1479 ) { 1480 anonportmax = old; 1481 return (EINVAL); 1482 } 1483 return (error); 1484 case IPCTL_MTUDISCTIMEOUT: 1485 error = sysctl_int(oldp, oldlenp, newp, newlen, 1486 &ip_mtudisc_timeout); 1487 if (ip_mtudisc_timeout_q != NULL) 1488 rt_timer_queue_change(ip_mtudisc_timeout_q, 1489 ip_mtudisc_timeout); 1490 return (error); 1491 #ifdef GATEWAY 1492 case IPCTL_MAXFLOWS: 1493 { 1494 int s; 1495 1496 error = sysctl_int(oldp, oldlenp, newp, newlen, 1497 &ip_maxflows); 1498 s = splsoftnet(); 1499 ipflow_reap(0); 1500 splx(s); 1501 return (error); 1502 } 1503 #endif 1504 default: 1505 return (EOPNOTSUPP); 1506 } 1507 /* NOTREACHED */ 1508 } 1509