ip_input.c revision 1.85
1/* $NetBSD: ip_input.c,v 1.85 1999/05/03 21:14:47 hwr 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 */ 143int ipforwarding = IPFORWARDING; 144int ipsendredirects = IPSENDREDIRECTS; 145int ip_defttl = IPDEFTTL; 146int ip_forwsrcrt = IPFORWSRCRT; 147int ip_directedbcast = IPDIRECTEDBCAST; 148int ip_allowsrcrt = IPALLOWSRCRT; 149int ip_mtudisc = IPMTUDISC; 150u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT; 151#ifdef DIAGNOSTIC 152int ipprintfs = 0; 153#endif 154 155struct rttimer_queue *ip_mtudisc_timeout_q = NULL; 156 157extern struct domain inetdomain; 158extern struct protosw inetsw[]; 159u_char ip_protox[IPPROTO_MAX]; 160int ipqmaxlen = IFQ_MAXLEN; 161struct in_ifaddrhead in_ifaddr; 162struct in_ifaddrhashhead *in_ifaddrhashtbl; 163struct ifqueue ipintrq; 164struct ipstat ipstat; 165u_int16_t ip_id; 166int ip_defttl; 167 168struct ipqhead ipq; 169int ipq_locked; 170 171static __inline int ipq_lock_try __P((void)); 172static __inline void ipq_unlock __P((void)); 173 174static __inline int 175ipq_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 189static __inline void 190ipq_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() \ 201do { \ 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() \ 208do { \ 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 221struct 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 */ 230int ip_nhops = 0; 231static 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 238static 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 */ 244void 245ip_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 277struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 278struct 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 */ 284void 285ipintr() 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 300next: 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 /* 344 * we drop packets that have a multicast address as source 345 * as wanted by rfc 1112 346 */ 347 if (IN_MULTICAST(ip->ip_src.s_addr)) { 348 ipstat.ips_odropped++; 349 goto bad; 350 } 351 352 if (in_cksum(m, hlen) != 0) { 353 ipstat.ips_badsum++; 354 goto bad; 355 } 356 357 /* 358 * Convert fields to host representation. 359 */ 360 NTOHS(ip->ip_len); 361 NTOHS(ip->ip_off); 362 len = ip->ip_len; 363 364 /* 365 * Check for additional length bogosity 366 */ 367 if (len < hlen) { 368 ipstat.ips_badlen++; 369 goto bad; 370 } 371 372 /* 373 * Check that the amount of data in the buffers 374 * is as at least much as the IP header would have us expect. 375 * Trim mbufs if longer than we expect. 376 * Drop packet if shorter than we expect. 377 */ 378 if (m->m_pkthdr.len < len) { 379 ipstat.ips_tooshort++; 380 goto bad; 381 } 382 if (m->m_pkthdr.len > len) { 383 if (m->m_len == m->m_pkthdr.len) { 384 m->m_len = len; 385 m->m_pkthdr.len = len; 386 } else 387 m_adj(m, len - m->m_pkthdr.len); 388 } 389 390 /* 391 * Assume that we can create a fast-forward IP flow entry 392 * based on this packet. 393 */ 394 m->m_flags |= M_CANFASTFWD; 395 396#ifdef PFIL_HOOKS 397 /* 398 * Run through list of hooks for input packets. If there are any 399 * filters which require that additional packets in the flow are 400 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 401 * Note that filters must _never_ set this flag, as another filter 402 * in the list may have previously cleared it. 403 */ 404 m0 = m; 405 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next) 406 if (pfh->pfil_func) { 407 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0); 408 if (rv) 409 goto next; 410 m = m0; 411 if (m == NULL) 412 goto next; 413 ip = mtod(m, struct ip *); 414 } 415#endif /* PFIL_HOOKS */ 416 417 /* 418 * Process options and, if not destined for us, 419 * ship it on. ip_dooptions returns 1 when an 420 * error was detected (causing an icmp message 421 * to be sent and the original packet to be freed). 422 */ 423 ip_nhops = 0; /* for source routed packets */ 424 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 425 goto next; 426 427 /* 428 * Check our list of addresses, to see if the packet is for us. 429 */ 430 INADDR_TO_IA(ip->ip_dst, ia); 431 if (ia != NULL) { 432 if (ia->ia_ifp->if_flags & IFF_UP) 433 goto ours; 434 } 435 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 436 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 437 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 438 if (ifa->ifa_addr->sa_family != AF_INET) continue; 439 ia = ifatoia(ifa); 440 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 441 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 442 /* 443 * Look for all-0's host part (old broadcast addr), 444 * either for subnet or net. 445 */ 446 ip->ip_dst.s_addr == ia->ia_subnet || 447 ip->ip_dst.s_addr == ia->ia_net) 448 goto ours; 449 /* 450 * An interface with IP address zero accepts 451 * all packets that arrive on that interface. 452 */ 453 if (in_nullhost(ia->ia_addr.sin_addr)) 454 goto ours; 455 } 456 } 457 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 458 struct in_multi *inm; 459#ifdef MROUTING 460 extern struct socket *ip_mrouter; 461 462 if (m->m_flags & M_EXT) { 463 if ((m = m_pullup(m, hlen)) == 0) { 464 ipstat.ips_toosmall++; 465 goto next; 466 } 467 ip = mtod(m, struct ip *); 468 } 469 470 if (ip_mrouter) { 471 /* 472 * If we are acting as a multicast router, all 473 * incoming multicast packets are passed to the 474 * kernel-level multicast forwarding function. 475 * The packet is returned (relatively) intact; if 476 * ip_mforward() returns a non-zero value, the packet 477 * must be discarded, else it may be accepted below. 478 * 479 * (The IP ident field is put in the same byte order 480 * as expected when ip_mforward() is called from 481 * ip_output().) 482 */ 483 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 484 ipstat.ips_cantforward++; 485 m_freem(m); 486 goto next; 487 } 488 489 /* 490 * The process-level routing demon needs to receive 491 * all multicast IGMP packets, whether or not this 492 * host belongs to their destination groups. 493 */ 494 if (ip->ip_p == IPPROTO_IGMP) 495 goto ours; 496 ipstat.ips_forward++; 497 } 498#endif 499 /* 500 * See if we belong to the destination multicast group on the 501 * arrival interface. 502 */ 503 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 504 if (inm == NULL) { 505 ipstat.ips_cantforward++; 506 m_freem(m); 507 goto next; 508 } 509 goto ours; 510 } 511 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 512 in_nullhost(ip->ip_dst)) 513 goto ours; 514 515 /* 516 * Not for us; forward if possible and desirable. 517 */ 518 if (ipforwarding == 0) { 519 ipstat.ips_cantforward++; 520 m_freem(m); 521 } else 522 ip_forward(m, 0); 523 goto next; 524 525ours: 526 /* 527 * If offset or IP_MF are set, must reassemble. 528 * Otherwise, nothing need be done. 529 * (We could look in the reassembly queue to see 530 * if the packet was previously fragmented, 531 * but it's not worth the time; just let them time out.) 532 */ 533 if (ip->ip_off & ~(IP_DF|IP_RF)) { 534 /* 535 * Look for queue of fragments 536 * of this datagram. 537 */ 538 IPQ_LOCK(); 539 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 540 if (ip->ip_id == fp->ipq_id && 541 in_hosteq(ip->ip_src, fp->ipq_src) && 542 in_hosteq(ip->ip_dst, fp->ipq_dst) && 543 ip->ip_p == fp->ipq_p) 544 goto found; 545 fp = 0; 546found: 547 548 /* 549 * Adjust ip_len to not reflect header, 550 * set ipqe_mff if more fragments are expected, 551 * convert offset of this to bytes. 552 */ 553 ip->ip_len -= hlen; 554 mff = (ip->ip_off & IP_MF) != 0; 555 if (mff) { 556 /* 557 * Make sure that fragments have a data length 558 * that's a non-zero multiple of 8 bytes. 559 */ 560 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 561 ipstat.ips_badfrags++; 562 IPQ_UNLOCK(); 563 goto bad; 564 } 565 } 566 ip->ip_off <<= 3; 567 568 /* 569 * If datagram marked as having more fragments 570 * or if this is not the first fragment, 571 * attempt reassembly; if it succeeds, proceed. 572 */ 573 if (mff || ip->ip_off) { 574 ipstat.ips_fragments++; 575 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 576 if (ipqe == NULL) { 577 ipstat.ips_rcvmemdrop++; 578 IPQ_UNLOCK(); 579 goto bad; 580 } 581 ipqe->ipqe_mff = mff; 582 ipqe->ipqe_m = m; 583 ipqe->ipqe_ip = ip; 584 m = ip_reass(ipqe, fp); 585 if (m == 0) { 586 IPQ_UNLOCK(); 587 goto next; 588 } 589 ipstat.ips_reassembled++; 590 ip = mtod(m, struct ip *); 591 hlen = ip->ip_hl << 2; 592 ip->ip_len += hlen; 593 } else 594 if (fp) 595 ip_freef(fp); 596 IPQ_UNLOCK(); 597 } 598 599 /* 600 * Switch out to protocol's input routine. 601 */ 602#if IFA_STATS 603 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len; 604#endif 605 ipstat.ips_delivered++; 606 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 607 goto next; 608bad: 609 m_freem(m); 610 goto next; 611} 612 613/* 614 * Take incoming datagram fragment and try to 615 * reassemble it into whole datagram. If a chain for 616 * reassembly of this datagram already exists, then it 617 * is given as fp; otherwise have to make a chain. 618 */ 619struct mbuf * 620ip_reass(ipqe, fp) 621 register struct ipqent *ipqe; 622 register struct ipq *fp; 623{ 624 register struct mbuf *m = ipqe->ipqe_m; 625 register struct ipqent *nq, *p, *q; 626 struct ip *ip; 627 struct mbuf *t; 628 int hlen = ipqe->ipqe_ip->ip_hl << 2; 629 int i, next; 630 631 IPQ_LOCK_CHECK(); 632 633 /* 634 * Presence of header sizes in mbufs 635 * would confuse code below. 636 */ 637 m->m_data += hlen; 638 m->m_len -= hlen; 639 640 /* 641 * If first fragment to arrive, create a reassembly queue. 642 */ 643 if (fp == 0) { 644 MALLOC(fp, struct ipq *, sizeof (struct ipq), 645 M_FTABLE, M_NOWAIT); 646 if (fp == NULL) 647 goto dropfrag; 648 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 649 fp->ipq_ttl = IPFRAGTTL; 650 fp->ipq_p = ipqe->ipqe_ip->ip_p; 651 fp->ipq_id = ipqe->ipqe_ip->ip_id; 652 LIST_INIT(&fp->ipq_fragq); 653 fp->ipq_src = ipqe->ipqe_ip->ip_src; 654 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 655 p = NULL; 656 goto insert; 657 } 658 659 /* 660 * Find a segment which begins after this one does. 661 */ 662 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 663 p = q, q = q->ipqe_q.le_next) 664 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 665 break; 666 667 /* 668 * If there is a preceding segment, it may provide some of 669 * our data already. If so, drop the data from the incoming 670 * segment. If it provides all of our data, drop us. 671 */ 672 if (p != NULL) { 673 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 674 ipqe->ipqe_ip->ip_off; 675 if (i > 0) { 676 if (i >= ipqe->ipqe_ip->ip_len) 677 goto dropfrag; 678 m_adj(ipqe->ipqe_m, i); 679 ipqe->ipqe_ip->ip_off += i; 680 ipqe->ipqe_ip->ip_len -= i; 681 } 682 } 683 684 /* 685 * While we overlap succeeding segments trim them or, 686 * if they are completely covered, dequeue them. 687 */ 688 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 689 q->ipqe_ip->ip_off; q = nq) { 690 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 691 q->ipqe_ip->ip_off; 692 if (i < q->ipqe_ip->ip_len) { 693 q->ipqe_ip->ip_len -= i; 694 q->ipqe_ip->ip_off += i; 695 m_adj(q->ipqe_m, i); 696 break; 697 } 698 nq = q->ipqe_q.le_next; 699 m_freem(q->ipqe_m); 700 LIST_REMOVE(q, ipqe_q); 701 pool_put(&ipqent_pool, q); 702 } 703 704insert: 705 /* 706 * Stick new segment in its place; 707 * check for complete reassembly. 708 */ 709 if (p == NULL) { 710 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 711 } else { 712 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 713 } 714 next = 0; 715 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 716 p = q, q = q->ipqe_q.le_next) { 717 if (q->ipqe_ip->ip_off != next) 718 return (0); 719 next += q->ipqe_ip->ip_len; 720 } 721 if (p->ipqe_mff) 722 return (0); 723 724 /* 725 * Reassembly is complete. Check for a bogus message size and 726 * concatenate fragments. 727 */ 728 q = fp->ipq_fragq.lh_first; 729 ip = q->ipqe_ip; 730 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 731 ipstat.ips_toolong++; 732 ip_freef(fp); 733 return (0); 734 } 735 m = q->ipqe_m; 736 t = m->m_next; 737 m->m_next = 0; 738 m_cat(m, t); 739 nq = q->ipqe_q.le_next; 740 pool_put(&ipqent_pool, q); 741 for (q = nq; q != NULL; q = nq) { 742 t = q->ipqe_m; 743 nq = q->ipqe_q.le_next; 744 pool_put(&ipqent_pool, q); 745 m_cat(m, t); 746 } 747 748 /* 749 * Create header for new ip packet by 750 * modifying header of first packet; 751 * dequeue and discard fragment reassembly header. 752 * Make header visible. 753 */ 754 ip->ip_len = next; 755 ip->ip_src = fp->ipq_src; 756 ip->ip_dst = fp->ipq_dst; 757 LIST_REMOVE(fp, ipq_q); 758 FREE(fp, M_FTABLE); 759 m->m_len += (ip->ip_hl << 2); 760 m->m_data -= (ip->ip_hl << 2); 761 /* some debugging cruft by sklower, below, will go away soon */ 762 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 763 register int plen = 0; 764 for (t = m; t; t = t->m_next) 765 plen += t->m_len; 766 m->m_pkthdr.len = plen; 767 } 768 return (m); 769 770dropfrag: 771 ipstat.ips_fragdropped++; 772 m_freem(m); 773 pool_put(&ipqent_pool, ipqe); 774 return (0); 775} 776 777/* 778 * Free a fragment reassembly header and all 779 * associated datagrams. 780 */ 781void 782ip_freef(fp) 783 struct ipq *fp; 784{ 785 register struct ipqent *q, *p; 786 787 IPQ_LOCK_CHECK(); 788 789 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 790 p = q->ipqe_q.le_next; 791 m_freem(q->ipqe_m); 792 LIST_REMOVE(q, ipqe_q); 793 pool_put(&ipqent_pool, q); 794 } 795 LIST_REMOVE(fp, ipq_q); 796 FREE(fp, M_FTABLE); 797} 798 799/* 800 * IP timer processing; 801 * if a timer expires on a reassembly 802 * queue, discard it. 803 */ 804void 805ip_slowtimo() 806{ 807 register struct ipq *fp, *nfp; 808 int s = splsoftnet(); 809 810 IPQ_LOCK(); 811 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 812 nfp = fp->ipq_q.le_next; 813 if (--fp->ipq_ttl == 0) { 814 ipstat.ips_fragtimeout++; 815 ip_freef(fp); 816 } 817 } 818 IPQ_UNLOCK(); 819#ifdef GATEWAY 820 ipflow_slowtimo(); 821#endif 822 splx(s); 823} 824 825/* 826 * Drain off all datagram fragments. 827 */ 828void 829ip_drain() 830{ 831 832 /* 833 * We may be called from a device's interrupt context. If 834 * the ipq is already busy, just bail out now. 835 */ 836 if (ipq_lock_try() == 0) 837 return; 838 839 while (ipq.lh_first != NULL) { 840 ipstat.ips_fragdropped++; 841 ip_freef(ipq.lh_first); 842 } 843 844 IPQ_UNLOCK(); 845} 846 847/* 848 * Do option processing on a datagram, 849 * possibly discarding it if bad options are encountered, 850 * or forwarding it if source-routed. 851 * Returns 1 if packet has been forwarded/freed, 852 * 0 if the packet should be processed further. 853 */ 854int 855ip_dooptions(m) 856 struct mbuf *m; 857{ 858 register struct ip *ip = mtod(m, struct ip *); 859 register u_char *cp; 860 register struct ip_timestamp *ipt; 861 register struct in_ifaddr *ia; 862 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 863 struct in_addr *sin, dst; 864 n_time ntime; 865 866 dst = ip->ip_dst; 867 cp = (u_char *)(ip + 1); 868 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 869 for (; cnt > 0; cnt -= optlen, cp += optlen) { 870 opt = cp[IPOPT_OPTVAL]; 871 if (opt == IPOPT_EOL) 872 break; 873 if (opt == IPOPT_NOP) 874 optlen = 1; 875 else { 876 optlen = cp[IPOPT_OLEN]; 877 if (optlen <= 0 || optlen > cnt) { 878 code = &cp[IPOPT_OLEN] - (u_char *)ip; 879 goto bad; 880 } 881 } 882 switch (opt) { 883 884 default: 885 break; 886 887 /* 888 * Source routing with record. 889 * Find interface with current destination address. 890 * If none on this machine then drop if strictly routed, 891 * or do nothing if loosely routed. 892 * Record interface address and bring up next address 893 * component. If strictly routed make sure next 894 * address is on directly accessible net. 895 */ 896 case IPOPT_LSRR: 897 case IPOPT_SSRR: 898 if (ip_allowsrcrt == 0) { 899 type = ICMP_UNREACH; 900 code = ICMP_UNREACH_NET_PROHIB; 901 goto bad; 902 } 903 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 904 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 905 goto bad; 906 } 907 ipaddr.sin_addr = ip->ip_dst; 908 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 909 if (ia == 0) { 910 if (opt == IPOPT_SSRR) { 911 type = ICMP_UNREACH; 912 code = ICMP_UNREACH_SRCFAIL; 913 goto bad; 914 } 915 /* 916 * Loose routing, and not at next destination 917 * yet; nothing to do except forward. 918 */ 919 break; 920 } 921 off--; /* 0 origin */ 922 if (off > optlen - sizeof(struct in_addr)) { 923 /* 924 * End of source route. Should be for us. 925 */ 926 save_rte(cp, ip->ip_src); 927 break; 928 } 929 /* 930 * locate outgoing interface 931 */ 932 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 933 sizeof(ipaddr.sin_addr)); 934 if (opt == IPOPT_SSRR) { 935#define INA struct in_ifaddr * 936#define SA struct sockaddr * 937 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 938 } else 939 ia = ip_rtaddr(ipaddr.sin_addr); 940 if (ia == 0) { 941 type = ICMP_UNREACH; 942 code = ICMP_UNREACH_SRCFAIL; 943 goto bad; 944 } 945 ip->ip_dst = ipaddr.sin_addr; 946 bcopy((caddr_t)&ia->ia_addr.sin_addr, 947 (caddr_t)(cp + off), sizeof(struct in_addr)); 948 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 949 /* 950 * Let ip_intr's mcast routing check handle mcast pkts 951 */ 952 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 953 break; 954 955 case IPOPT_RR: 956 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 957 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 958 goto bad; 959 } 960 /* 961 * If no space remains, ignore. 962 */ 963 off--; /* 0 origin */ 964 if (off > optlen - sizeof(struct in_addr)) 965 break; 966 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 967 sizeof(ipaddr.sin_addr)); 968 /* 969 * locate outgoing interface; if we're the destination, 970 * use the incoming interface (should be same). 971 */ 972 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 973 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 974 type = ICMP_UNREACH; 975 code = ICMP_UNREACH_HOST; 976 goto bad; 977 } 978 bcopy((caddr_t)&ia->ia_addr.sin_addr, 979 (caddr_t)(cp + off), sizeof(struct in_addr)); 980 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 981 break; 982 983 case IPOPT_TS: 984 code = cp - (u_char *)ip; 985 ipt = (struct ip_timestamp *)cp; 986 if (ipt->ipt_len < 5) 987 goto bad; 988 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 989 if (++ipt->ipt_oflw == 0) 990 goto bad; 991 break; 992 } 993 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 994 switch (ipt->ipt_flg) { 995 996 case IPOPT_TS_TSONLY: 997 break; 998 999 case IPOPT_TS_TSANDADDR: 1000 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1001 sizeof(struct in_addr) > ipt->ipt_len) 1002 goto bad; 1003 ipaddr.sin_addr = dst; 1004 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1005 m->m_pkthdr.rcvif); 1006 if (ia == 0) 1007 continue; 1008 bcopy((caddr_t)&ia->ia_addr.sin_addr, 1009 (caddr_t)sin, sizeof(struct in_addr)); 1010 ipt->ipt_ptr += sizeof(struct in_addr); 1011 break; 1012 1013 case IPOPT_TS_PRESPEC: 1014 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1015 sizeof(struct in_addr) > ipt->ipt_len) 1016 goto bad; 1017 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 1018 sizeof(struct in_addr)); 1019 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1020 continue; 1021 ipt->ipt_ptr += sizeof(struct in_addr); 1022 break; 1023 1024 default: 1025 goto bad; 1026 } 1027 ntime = iptime(); 1028 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1029 sizeof(n_time)); 1030 ipt->ipt_ptr += sizeof(n_time); 1031 } 1032 } 1033 if (forward) { 1034 if (ip_forwsrcrt == 0) { 1035 type = ICMP_UNREACH; 1036 code = ICMP_UNREACH_SRCFAIL; 1037 goto bad; 1038 } 1039 ip_forward(m, 1); 1040 return (1); 1041 } 1042 return (0); 1043bad: 1044 icmp_error(m, type, code, 0, 0); 1045 ipstat.ips_badoptions++; 1046 return (1); 1047} 1048 1049/* 1050 * Given address of next destination (final or next hop), 1051 * return internet address info of interface to be used to get there. 1052 */ 1053struct in_ifaddr * 1054ip_rtaddr(dst) 1055 struct in_addr dst; 1056{ 1057 register struct sockaddr_in *sin; 1058 1059 sin = satosin(&ipforward_rt.ro_dst); 1060 1061 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1062 if (ipforward_rt.ro_rt) { 1063 RTFREE(ipforward_rt.ro_rt); 1064 ipforward_rt.ro_rt = 0; 1065 } 1066 sin->sin_family = AF_INET; 1067 sin->sin_len = sizeof(*sin); 1068 sin->sin_addr = dst; 1069 1070 rtalloc(&ipforward_rt); 1071 } 1072 if (ipforward_rt.ro_rt == 0) 1073 return ((struct in_ifaddr *)0); 1074 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1075} 1076 1077/* 1078 * Save incoming source route for use in replies, 1079 * to be picked up later by ip_srcroute if the receiver is interested. 1080 */ 1081void 1082save_rte(option, dst) 1083 u_char *option; 1084 struct in_addr dst; 1085{ 1086 unsigned olen; 1087 1088 olen = option[IPOPT_OLEN]; 1089#ifdef DIAGNOSTIC 1090 if (ipprintfs) 1091 printf("save_rte: olen %d\n", olen); 1092#endif 1093 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1094 return; 1095 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1096 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1097 ip_srcrt.dst = dst; 1098} 1099 1100/* 1101 * Retrieve incoming source route for use in replies, 1102 * in the same form used by setsockopt. 1103 * The first hop is placed before the options, will be removed later. 1104 */ 1105struct mbuf * 1106ip_srcroute() 1107{ 1108 register struct in_addr *p, *q; 1109 register struct mbuf *m; 1110 1111 if (ip_nhops == 0) 1112 return ((struct mbuf *)0); 1113 m = m_get(M_DONTWAIT, MT_SOOPTS); 1114 if (m == 0) 1115 return ((struct mbuf *)0); 1116 1117#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1118 1119 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1120 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1121 OPTSIZ; 1122#ifdef DIAGNOSTIC 1123 if (ipprintfs) 1124 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1125#endif 1126 1127 /* 1128 * First save first hop for return route 1129 */ 1130 p = &ip_srcrt.route[ip_nhops - 1]; 1131 *(mtod(m, struct in_addr *)) = *p--; 1132#ifdef DIAGNOSTIC 1133 if (ipprintfs) 1134 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1135#endif 1136 1137 /* 1138 * Copy option fields and padding (nop) to mbuf. 1139 */ 1140 ip_srcrt.nop = IPOPT_NOP; 1141 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1142 bcopy((caddr_t)&ip_srcrt.nop, 1143 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1144 q = (struct in_addr *)(mtod(m, caddr_t) + 1145 sizeof(struct in_addr) + OPTSIZ); 1146#undef OPTSIZ 1147 /* 1148 * Record return path as an IP source route, 1149 * reversing the path (pointers are now aligned). 1150 */ 1151 while (p >= ip_srcrt.route) { 1152#ifdef DIAGNOSTIC 1153 if (ipprintfs) 1154 printf(" %x", ntohl(q->s_addr)); 1155#endif 1156 *q++ = *p--; 1157 } 1158 /* 1159 * Last hop goes to final destination. 1160 */ 1161 *q = ip_srcrt.dst; 1162#ifdef DIAGNOSTIC 1163 if (ipprintfs) 1164 printf(" %x\n", ntohl(q->s_addr)); 1165#endif 1166 return (m); 1167} 1168 1169/* 1170 * Strip out IP options, at higher 1171 * level protocol in the kernel. 1172 * Second argument is buffer to which options 1173 * will be moved, and return value is their length. 1174 * XXX should be deleted; last arg currently ignored. 1175 */ 1176void 1177ip_stripoptions(m, mopt) 1178 register struct mbuf *m; 1179 struct mbuf *mopt; 1180{ 1181 register int i; 1182 struct ip *ip = mtod(m, struct ip *); 1183 register caddr_t opts; 1184 int olen; 1185 1186 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1187 opts = (caddr_t)(ip + 1); 1188 i = m->m_len - (sizeof (struct ip) + olen); 1189 bcopy(opts + olen, opts, (unsigned)i); 1190 m->m_len -= olen; 1191 if (m->m_flags & M_PKTHDR) 1192 m->m_pkthdr.len -= olen; 1193 ip->ip_len -= olen; 1194 ip->ip_hl = sizeof (struct ip) >> 2; 1195} 1196 1197int inetctlerrmap[PRC_NCMDS] = { 1198 0, 0, 0, 0, 1199 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1200 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1201 EMSGSIZE, EHOSTUNREACH, 0, 0, 1202 0, 0, 0, 0, 1203 ENOPROTOOPT 1204}; 1205 1206/* 1207 * Forward a packet. If some error occurs return the sender 1208 * an icmp packet. Note we can't always generate a meaningful 1209 * icmp message because icmp doesn't have a large enough repertoire 1210 * of codes and types. 1211 * 1212 * If not forwarding, just drop the packet. This could be confusing 1213 * if ipforwarding was zero but some routing protocol was advancing 1214 * us as a gateway to somewhere. However, we must let the routing 1215 * protocol deal with that. 1216 * 1217 * The srcrt parameter indicates whether the packet is being forwarded 1218 * via a source route. 1219 */ 1220void 1221ip_forward(m, srcrt) 1222 struct mbuf *m; 1223 int srcrt; 1224{ 1225 register struct ip *ip = mtod(m, struct ip *); 1226 register struct sockaddr_in *sin; 1227 register struct rtentry *rt; 1228 int error, type = 0, code = 0; 1229 struct mbuf *mcopy; 1230 n_long dest; 1231 struct ifnet *destifp; 1232 1233 dest = 0; 1234#ifdef DIAGNOSTIC 1235 if (ipprintfs) 1236 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1237 ntohl(ip->ip_src.s_addr), 1238 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1239#endif 1240 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1241 ipstat.ips_cantforward++; 1242 m_freem(m); 1243 return; 1244 } 1245 if (ip->ip_ttl <= IPTTLDEC) { 1246 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1247 return; 1248 } 1249 ip->ip_ttl -= IPTTLDEC; 1250 1251 sin = satosin(&ipforward_rt.ro_dst); 1252 if ((rt = ipforward_rt.ro_rt) == 0 || 1253 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1254 if (ipforward_rt.ro_rt) { 1255 RTFREE(ipforward_rt.ro_rt); 1256 ipforward_rt.ro_rt = 0; 1257 } 1258 sin->sin_family = AF_INET; 1259 sin->sin_len = sizeof(struct sockaddr_in); 1260 sin->sin_addr = ip->ip_dst; 1261 1262 rtalloc(&ipforward_rt); 1263 if (ipforward_rt.ro_rt == 0) { 1264 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1265 return; 1266 } 1267 rt = ipforward_rt.ro_rt; 1268 } 1269 1270 /* 1271 * Save at most 68 bytes of the packet in case 1272 * we need to generate an ICMP message to the src. 1273 */ 1274 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1275 1276 /* 1277 * If forwarding packet using same interface that it came in on, 1278 * perhaps should send a redirect to sender to shortcut a hop. 1279 * Only send redirect if source is sending directly to us, 1280 * and if packet was not source routed (or has any options). 1281 * Also, don't send redirect if forwarding using a default route 1282 * or a route modified by a redirect. 1283 */ 1284 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1285 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1286 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1287 ipsendredirects && !srcrt) { 1288 if (rt->rt_ifa && 1289 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1290 ifatoia(rt->rt_ifa)->ia_subnet) { 1291 if (rt->rt_flags & RTF_GATEWAY) 1292 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1293 else 1294 dest = ip->ip_dst.s_addr; 1295 /* 1296 * Router requirements says to only send host 1297 * redirects. 1298 */ 1299 type = ICMP_REDIRECT; 1300 code = ICMP_REDIRECT_HOST; 1301#ifdef DIAGNOSTIC 1302 if (ipprintfs) 1303 printf("redirect (%d) to %x\n", code, 1304 (u_int32_t)dest); 1305#endif 1306 } 1307 } 1308 1309 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1310 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1311 if (error) 1312 ipstat.ips_cantforward++; 1313 else { 1314 ipstat.ips_forward++; 1315 if (type) 1316 ipstat.ips_redirectsent++; 1317 else { 1318 if (mcopy) { 1319#ifdef GATEWAY 1320 if (mcopy->m_flags & M_CANFASTFWD) 1321 ipflow_create(&ipforward_rt, mcopy); 1322#endif 1323 m_freem(mcopy); 1324 } 1325 return; 1326 } 1327 } 1328 if (mcopy == NULL) 1329 return; 1330 destifp = NULL; 1331 1332 switch (error) { 1333 1334 case 0: /* forwarded, but need redirect */ 1335 /* type, code set above */ 1336 break; 1337 1338 case ENETUNREACH: /* shouldn't happen, checked above */ 1339 case EHOSTUNREACH: 1340 case ENETDOWN: 1341 case EHOSTDOWN: 1342 default: 1343 type = ICMP_UNREACH; 1344 code = ICMP_UNREACH_HOST; 1345 break; 1346 1347 case EMSGSIZE: 1348 type = ICMP_UNREACH; 1349 code = ICMP_UNREACH_NEEDFRAG; 1350 if (ipforward_rt.ro_rt) 1351 destifp = ipforward_rt.ro_rt->rt_ifp; 1352 ipstat.ips_cantfrag++; 1353 break; 1354 1355 case ENOBUFS: 1356 type = ICMP_SOURCEQUENCH; 1357 code = 0; 1358 break; 1359 } 1360 icmp_error(mcopy, type, code, dest, destifp); 1361} 1362 1363void 1364ip_savecontrol(inp, mp, ip, m) 1365 register struct inpcb *inp; 1366 register struct mbuf **mp; 1367 register struct ip *ip; 1368 register struct mbuf *m; 1369{ 1370 1371 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1372 struct timeval tv; 1373 1374 microtime(&tv); 1375 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1376 SCM_TIMESTAMP, SOL_SOCKET); 1377 if (*mp) 1378 mp = &(*mp)->m_next; 1379 } 1380 if (inp->inp_flags & INP_RECVDSTADDR) { 1381 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1382 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1383 if (*mp) 1384 mp = &(*mp)->m_next; 1385 } 1386#ifdef notyet 1387 /* 1388 * XXX 1389 * Moving these out of udp_input() made them even more broken 1390 * than they already were. 1391 * - fenner@parc.xerox.com 1392 */ 1393 /* options were tossed already */ 1394 if (inp->inp_flags & INP_RECVOPTS) { 1395 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1396 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1397 if (*mp) 1398 mp = &(*mp)->m_next; 1399 } 1400 /* ip_srcroute doesn't do what we want here, need to fix */ 1401 if (inp->inp_flags & INP_RECVRETOPTS) { 1402 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1403 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1404 if (*mp) 1405 mp = &(*mp)->m_next; 1406 } 1407#endif 1408 if (inp->inp_flags & INP_RECVIF) { 1409 struct sockaddr_dl sdl; 1410 1411 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1412 sdl.sdl_family = AF_LINK; 1413 sdl.sdl_index = m->m_pkthdr.rcvif ? 1414 m->m_pkthdr.rcvif->if_index : 0; 1415 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1416 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1417 IP_RECVIF, IPPROTO_IP); 1418 if (*mp) 1419 mp = &(*mp)->m_next; 1420 } 1421} 1422 1423int 1424ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1425 int *name; 1426 u_int namelen; 1427 void *oldp; 1428 size_t *oldlenp; 1429 void *newp; 1430 size_t newlen; 1431{ 1432 extern int subnetsarelocal; 1433 1434 int error, old; 1435 1436 /* All sysctl names at this level are terminal. */ 1437 if (namelen != 1) 1438 return (ENOTDIR); 1439 1440 switch (name[0]) { 1441 case IPCTL_FORWARDING: 1442 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1443 case IPCTL_SENDREDIRECTS: 1444 return (sysctl_int(oldp, oldlenp, newp, newlen, 1445 &ipsendredirects)); 1446 case IPCTL_DEFTTL: 1447 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1448#ifdef notyet 1449 case IPCTL_DEFMTU: 1450 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1451#endif 1452 case IPCTL_FORWSRCRT: 1453 /* Don't allow this to change in a secure environment. */ 1454 if (securelevel > 0) 1455 return (sysctl_rdint(oldp, oldlenp, newp, 1456 ip_forwsrcrt)); 1457 else 1458 return (sysctl_int(oldp, oldlenp, newp, newlen, 1459 &ip_forwsrcrt)); 1460 case IPCTL_DIRECTEDBCAST: 1461 return (sysctl_int(oldp, oldlenp, newp, newlen, 1462 &ip_directedbcast)); 1463 case IPCTL_ALLOWSRCRT: 1464 return (sysctl_int(oldp, oldlenp, newp, newlen, 1465 &ip_allowsrcrt)); 1466 case IPCTL_SUBNETSARELOCAL: 1467 return (sysctl_int(oldp, oldlenp, newp, newlen, 1468 &subnetsarelocal)); 1469 case IPCTL_MTUDISC: 1470 error = sysctl_int(oldp, oldlenp, newp, newlen, 1471 &ip_mtudisc); 1472 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1473 ip_mtudisc_timeout_q = 1474 rt_timer_queue_create(ip_mtudisc_timeout); 1475 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1476 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1477 ip_mtudisc_timeout_q = NULL; 1478 } 1479 return error; 1480 case IPCTL_ANONPORTMIN: 1481 old = anonportmin; 1482 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1483 if (anonportmin >= anonportmax || anonportmin > 65535 1484#ifndef IPNOPRIVPORTS 1485 || anonportmin < IPPORT_RESERVED 1486#endif 1487 ) { 1488 anonportmin = old; 1489 return (EINVAL); 1490 } 1491 return (error); 1492 case IPCTL_ANONPORTMAX: 1493 old = anonportmax; 1494 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1495 if (anonportmin >= anonportmax || anonportmax > 65535 1496#ifndef IPNOPRIVPORTS 1497 || anonportmax < IPPORT_RESERVED 1498#endif 1499 ) { 1500 anonportmax = old; 1501 return (EINVAL); 1502 } 1503 return (error); 1504 case IPCTL_MTUDISCTIMEOUT: 1505 error = sysctl_int(oldp, oldlenp, newp, newlen, 1506 &ip_mtudisc_timeout); 1507 if (ip_mtudisc_timeout_q != NULL) 1508 rt_timer_queue_change(ip_mtudisc_timeout_q, 1509 ip_mtudisc_timeout); 1510 return (error); 1511#ifdef GATEWAY 1512 case IPCTL_MAXFLOWS: 1513 { 1514 int s; 1515 1516 error = sysctl_int(oldp, oldlenp, newp, newlen, 1517 &ip_maxflows); 1518 s = splsoftnet(); 1519 ipflow_reap(0); 1520 splx(s); 1521 return (error); 1522 } 1523#endif 1524 default: 1525 return (EOPNOTSUPP); 1526 } 1527 /* NOTREACHED */ 1528} 1529