ip_input.c revision 1.82
1/* $NetBSD: ip_input.c,v 1.82 1999/03/27 01:24:49 aidan 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 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 for additional length bogosity 357 */ 358 if (len < hlen) 359 { 360 ipstat.ips_badlen++; 361 goto bad; 362 } 363 364 /* 365 * Check that the amount of data in the buffers 366 * is as at least much as the IP header would have us expect. 367 * Trim mbufs if longer than we expect. 368 * Drop packet if shorter than we expect. 369 */ 370 if (m->m_pkthdr.len < len) { 371 ipstat.ips_tooshort++; 372 goto bad; 373 } 374 if (m->m_pkthdr.len > len) { 375 if (m->m_len == m->m_pkthdr.len) { 376 m->m_len = len; 377 m->m_pkthdr.len = len; 378 } else 379 m_adj(m, len - m->m_pkthdr.len); 380 } 381 382 /* 383 * Assume that we can create a fast-forward IP flow entry 384 * based on this packet. 385 */ 386 m->m_flags |= M_CANFASTFWD; 387 388#ifdef PFIL_HOOKS 389 /* 390 * Run through list of hooks for input packets. If there are any 391 * filters which require that additional packets in the flow are 392 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 393 * Note that filters must _never_ set this flag, as another filter 394 * in the list may have previously cleared it. 395 */ 396 m0 = m; 397 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next) 398 if (pfh->pfil_func) { 399 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0); 400 if (rv) 401 goto next; 402 m = m0; 403 if (m == NULL) 404 goto next; 405 ip = mtod(m, struct ip *); 406 } 407#endif /* PFIL_HOOKS */ 408 409 /* 410 * Process options and, if not destined for us, 411 * ship it on. ip_dooptions returns 1 when an 412 * error was detected (causing an icmp message 413 * to be sent and the original packet to be freed). 414 */ 415 ip_nhops = 0; /* for source routed packets */ 416 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 417 goto next; 418 419 /* 420 * Check our list of addresses, to see if the packet is for us. 421 */ 422 INADDR_TO_IA(ip->ip_dst, ia); 423 if (ia != NULL) goto ours; 424 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 425 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 426 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 427 if (ifa->ifa_addr->sa_family != AF_INET) continue; 428 ia = ifatoia(ifa); 429 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 430 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 431 /* 432 * Look for all-0's host part (old broadcast addr), 433 * either for subnet or net. 434 */ 435 ip->ip_dst.s_addr == ia->ia_subnet || 436 ip->ip_dst.s_addr == ia->ia_net) 437 goto ours; 438 /* 439 * An interface with IP address zero accepts 440 * all packets that arrive on that interface. 441 */ 442 if (in_nullhost(ia->ia_addr.sin_addr)) 443 goto ours; 444 } 445 } 446 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 447 struct in_multi *inm; 448#ifdef MROUTING 449 extern struct socket *ip_mrouter; 450 451 if (m->m_flags & M_EXT) { 452 if ((m = m_pullup(m, hlen)) == 0) { 453 ipstat.ips_toosmall++; 454 goto next; 455 } 456 ip = mtod(m, struct ip *); 457 } 458 459 if (ip_mrouter) { 460 /* 461 * If we are acting as a multicast router, all 462 * incoming multicast packets are passed to the 463 * kernel-level multicast forwarding function. 464 * The packet is returned (relatively) intact; if 465 * ip_mforward() returns a non-zero value, the packet 466 * must be discarded, else it may be accepted below. 467 * 468 * (The IP ident field is put in the same byte order 469 * as expected when ip_mforward() is called from 470 * ip_output().) 471 */ 472 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 473 ipstat.ips_cantforward++; 474 m_freem(m); 475 goto next; 476 } 477 478 /* 479 * The process-level routing demon needs to receive 480 * all multicast IGMP packets, whether or not this 481 * host belongs to their destination groups. 482 */ 483 if (ip->ip_p == IPPROTO_IGMP) 484 goto ours; 485 ipstat.ips_forward++; 486 } 487#endif 488 /* 489 * See if we belong to the destination multicast group on the 490 * arrival interface. 491 */ 492 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 493 if (inm == NULL) { 494 ipstat.ips_cantforward++; 495 m_freem(m); 496 goto next; 497 } 498 goto ours; 499 } 500 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 501 in_nullhost(ip->ip_dst)) 502 goto ours; 503 504 /* 505 * Not for us; forward if possible and desirable. 506 */ 507 if (ipforwarding == 0) { 508 ipstat.ips_cantforward++; 509 m_freem(m); 510 } else 511 ip_forward(m, 0); 512 goto next; 513 514ours: 515 /* 516 * If offset or IP_MF are set, must reassemble. 517 * Otherwise, nothing need be done. 518 * (We could look in the reassembly queue to see 519 * if the packet was previously fragmented, 520 * but it's not worth the time; just let them time out.) 521 */ 522 if (ip->ip_off & ~(IP_DF|IP_RF)) { 523 /* 524 * Look for queue of fragments 525 * of this datagram. 526 */ 527 IPQ_LOCK(); 528 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 529 if (ip->ip_id == fp->ipq_id && 530 in_hosteq(ip->ip_src, fp->ipq_src) && 531 in_hosteq(ip->ip_dst, fp->ipq_dst) && 532 ip->ip_p == fp->ipq_p) 533 goto found; 534 fp = 0; 535found: 536 537 /* 538 * Adjust ip_len to not reflect header, 539 * set ipqe_mff if more fragments are expected, 540 * convert offset of this to bytes. 541 */ 542 ip->ip_len -= hlen; 543 mff = (ip->ip_off & IP_MF) != 0; 544 if (mff) { 545 /* 546 * Make sure that fragments have a data length 547 * that's a non-zero multiple of 8 bytes. 548 */ 549 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 550 ipstat.ips_badfrags++; 551 IPQ_UNLOCK(); 552 goto bad; 553 } 554 } 555 ip->ip_off <<= 3; 556 557 /* 558 * If datagram marked as having more fragments 559 * or if this is not the first fragment, 560 * attempt reassembly; if it succeeds, proceed. 561 */ 562 if (mff || ip->ip_off) { 563 ipstat.ips_fragments++; 564 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 565 if (ipqe == NULL) { 566 ipstat.ips_rcvmemdrop++; 567 IPQ_UNLOCK(); 568 goto bad; 569 } 570 ipqe->ipqe_mff = mff; 571 ipqe->ipqe_m = m; 572 ipqe->ipqe_ip = ip; 573 m = ip_reass(ipqe, fp); 574 if (m == 0) { 575 IPQ_UNLOCK(); 576 goto next; 577 } 578 ipstat.ips_reassembled++; 579 ip = mtod(m, struct ip *); 580 hlen = ip->ip_hl << 2; 581 ip->ip_len += hlen; 582 } else 583 if (fp) 584 ip_freef(fp); 585 IPQ_UNLOCK(); 586 } 587 588 /* 589 * Switch out to protocol's input routine. 590 */ 591#if IFA_STATS 592 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len; 593#endif 594 ipstat.ips_delivered++; 595 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 596 goto next; 597bad: 598 m_freem(m); 599 goto next; 600} 601 602/* 603 * Take incoming datagram fragment and try to 604 * reassemble it into whole datagram. If a chain for 605 * reassembly of this datagram already exists, then it 606 * is given as fp; otherwise have to make a chain. 607 */ 608struct mbuf * 609ip_reass(ipqe, fp) 610 register struct ipqent *ipqe; 611 register struct ipq *fp; 612{ 613 register struct mbuf *m = ipqe->ipqe_m; 614 register struct ipqent *nq, *p, *q; 615 struct ip *ip; 616 struct mbuf *t; 617 int hlen = ipqe->ipqe_ip->ip_hl << 2; 618 int i, next; 619 620 IPQ_LOCK_CHECK(); 621 622 /* 623 * Presence of header sizes in mbufs 624 * would confuse code below. 625 */ 626 m->m_data += hlen; 627 m->m_len -= hlen; 628 629 /* 630 * If first fragment to arrive, create a reassembly queue. 631 */ 632 if (fp == 0) { 633 MALLOC(fp, struct ipq *, sizeof (struct ipq), 634 M_FTABLE, M_NOWAIT); 635 if (fp == NULL) 636 goto dropfrag; 637 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 638 fp->ipq_ttl = IPFRAGTTL; 639 fp->ipq_p = ipqe->ipqe_ip->ip_p; 640 fp->ipq_id = ipqe->ipqe_ip->ip_id; 641 LIST_INIT(&fp->ipq_fragq); 642 fp->ipq_src = ipqe->ipqe_ip->ip_src; 643 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 644 p = NULL; 645 goto insert; 646 } 647 648 /* 649 * Find a segment which begins after this one does. 650 */ 651 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 652 p = q, q = q->ipqe_q.le_next) 653 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 654 break; 655 656 /* 657 * If there is a preceding segment, it may provide some of 658 * our data already. If so, drop the data from the incoming 659 * segment. If it provides all of our data, drop us. 660 */ 661 if (p != NULL) { 662 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 663 ipqe->ipqe_ip->ip_off; 664 if (i > 0) { 665 if (i >= ipqe->ipqe_ip->ip_len) 666 goto dropfrag; 667 m_adj(ipqe->ipqe_m, i); 668 ipqe->ipqe_ip->ip_off += i; 669 ipqe->ipqe_ip->ip_len -= i; 670 } 671 } 672 673 /* 674 * While we overlap succeeding segments trim them or, 675 * if they are completely covered, dequeue them. 676 */ 677 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 678 q->ipqe_ip->ip_off; q = nq) { 679 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 680 q->ipqe_ip->ip_off; 681 if (i < q->ipqe_ip->ip_len) { 682 q->ipqe_ip->ip_len -= i; 683 q->ipqe_ip->ip_off += i; 684 m_adj(q->ipqe_m, i); 685 break; 686 } 687 nq = q->ipqe_q.le_next; 688 m_freem(q->ipqe_m); 689 LIST_REMOVE(q, ipqe_q); 690 pool_put(&ipqent_pool, q); 691 } 692 693insert: 694 /* 695 * Stick new segment in its place; 696 * check for complete reassembly. 697 */ 698 if (p == NULL) { 699 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 700 } else { 701 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 702 } 703 next = 0; 704 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 705 p = q, q = q->ipqe_q.le_next) { 706 if (q->ipqe_ip->ip_off != next) 707 return (0); 708 next += q->ipqe_ip->ip_len; 709 } 710 if (p->ipqe_mff) 711 return (0); 712 713 /* 714 * Reassembly is complete. Check for a bogus message size and 715 * concatenate fragments. 716 */ 717 q = fp->ipq_fragq.lh_first; 718 ip = q->ipqe_ip; 719 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 720 ipstat.ips_toolong++; 721 ip_freef(fp); 722 return (0); 723 } 724 m = q->ipqe_m; 725 t = m->m_next; 726 m->m_next = 0; 727 m_cat(m, t); 728 nq = q->ipqe_q.le_next; 729 pool_put(&ipqent_pool, q); 730 for (q = nq; q != NULL; q = nq) { 731 t = q->ipqe_m; 732 nq = q->ipqe_q.le_next; 733 pool_put(&ipqent_pool, q); 734 m_cat(m, t); 735 } 736 737 /* 738 * Create header for new ip packet by 739 * modifying header of first packet; 740 * dequeue and discard fragment reassembly header. 741 * Make header visible. 742 */ 743 ip->ip_len = next; 744 ip->ip_src = fp->ipq_src; 745 ip->ip_dst = fp->ipq_dst; 746 LIST_REMOVE(fp, ipq_q); 747 FREE(fp, M_FTABLE); 748 m->m_len += (ip->ip_hl << 2); 749 m->m_data -= (ip->ip_hl << 2); 750 /* some debugging cruft by sklower, below, will go away soon */ 751 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 752 register int plen = 0; 753 for (t = m; t; t = t->m_next) 754 plen += t->m_len; 755 m->m_pkthdr.len = plen; 756 } 757 return (m); 758 759dropfrag: 760 ipstat.ips_fragdropped++; 761 m_freem(m); 762 pool_put(&ipqent_pool, ipqe); 763 return (0); 764} 765 766/* 767 * Free a fragment reassembly header and all 768 * associated datagrams. 769 */ 770void 771ip_freef(fp) 772 struct ipq *fp; 773{ 774 register struct ipqent *q, *p; 775 776 IPQ_LOCK_CHECK(); 777 778 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 779 p = q->ipqe_q.le_next; 780 m_freem(q->ipqe_m); 781 LIST_REMOVE(q, ipqe_q); 782 pool_put(&ipqent_pool, q); 783 } 784 LIST_REMOVE(fp, ipq_q); 785 FREE(fp, M_FTABLE); 786} 787 788/* 789 * IP timer processing; 790 * if a timer expires on a reassembly 791 * queue, discard it. 792 */ 793void 794ip_slowtimo() 795{ 796 register struct ipq *fp, *nfp; 797 int s = splsoftnet(); 798 799 IPQ_LOCK(); 800 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 801 nfp = fp->ipq_q.le_next; 802 if (--fp->ipq_ttl == 0) { 803 ipstat.ips_fragtimeout++; 804 ip_freef(fp); 805 } 806 } 807 IPQ_UNLOCK(); 808#ifdef GATEWAY 809 ipflow_slowtimo(); 810#endif 811 splx(s); 812} 813 814/* 815 * Drain off all datagram fragments. 816 */ 817void 818ip_drain() 819{ 820 821 /* 822 * We may be called from a device's interrupt context. If 823 * the ipq is already busy, just bail out now. 824 */ 825 if (ipq_lock_try() == 0) 826 return; 827 828 while (ipq.lh_first != NULL) { 829 ipstat.ips_fragdropped++; 830 ip_freef(ipq.lh_first); 831 } 832 833 IPQ_UNLOCK(); 834} 835 836/* 837 * Do option processing on a datagram, 838 * possibly discarding it if bad options are encountered, 839 * or forwarding it if source-routed. 840 * Returns 1 if packet has been forwarded/freed, 841 * 0 if the packet should be processed further. 842 */ 843int 844ip_dooptions(m) 845 struct mbuf *m; 846{ 847 register struct ip *ip = mtod(m, struct ip *); 848 register u_char *cp; 849 register struct ip_timestamp *ipt; 850 register struct in_ifaddr *ia; 851 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 852 struct in_addr *sin, dst; 853 n_time ntime; 854 855 dst = ip->ip_dst; 856 cp = (u_char *)(ip + 1); 857 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 858 for (; cnt > 0; cnt -= optlen, cp += optlen) { 859 opt = cp[IPOPT_OPTVAL]; 860 if (opt == IPOPT_EOL) 861 break; 862 if (opt == IPOPT_NOP) 863 optlen = 1; 864 else { 865 optlen = cp[IPOPT_OLEN]; 866 if (optlen <= 0 || optlen > cnt) { 867 code = &cp[IPOPT_OLEN] - (u_char *)ip; 868 goto bad; 869 } 870 } 871 switch (opt) { 872 873 default: 874 break; 875 876 /* 877 * Source routing with record. 878 * Find interface with current destination address. 879 * If none on this machine then drop if strictly routed, 880 * or do nothing if loosely routed. 881 * Record interface address and bring up next address 882 * component. If strictly routed make sure next 883 * address is on directly accessible net. 884 */ 885 case IPOPT_LSRR: 886 case IPOPT_SSRR: 887 if (ip_allowsrcrt == 0) { 888 type = ICMP_UNREACH; 889 code = ICMP_UNREACH_NET_PROHIB; 890 goto bad; 891 } 892 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 893 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 894 goto bad; 895 } 896 ipaddr.sin_addr = ip->ip_dst; 897 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 898 if (ia == 0) { 899 if (opt == IPOPT_SSRR) { 900 type = ICMP_UNREACH; 901 code = ICMP_UNREACH_SRCFAIL; 902 goto bad; 903 } 904 /* 905 * Loose routing, and not at next destination 906 * yet; nothing to do except forward. 907 */ 908 break; 909 } 910 off--; /* 0 origin */ 911 if (off > optlen - sizeof(struct in_addr)) { 912 /* 913 * End of source route. Should be for us. 914 */ 915 save_rte(cp, ip->ip_src); 916 break; 917 } 918 /* 919 * locate outgoing interface 920 */ 921 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 922 sizeof(ipaddr.sin_addr)); 923 if (opt == IPOPT_SSRR) { 924#define INA struct in_ifaddr * 925#define SA struct sockaddr * 926 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 927 } else 928 ia = ip_rtaddr(ipaddr.sin_addr); 929 if (ia == 0) { 930 type = ICMP_UNREACH; 931 code = ICMP_UNREACH_SRCFAIL; 932 goto bad; 933 } 934 ip->ip_dst = ipaddr.sin_addr; 935 bcopy((caddr_t)&ia->ia_addr.sin_addr, 936 (caddr_t)(cp + off), sizeof(struct in_addr)); 937 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 938 /* 939 * Let ip_intr's mcast routing check handle mcast pkts 940 */ 941 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 942 break; 943 944 case IPOPT_RR: 945 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 946 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 947 goto bad; 948 } 949 /* 950 * If no space remains, ignore. 951 */ 952 off--; /* 0 origin */ 953 if (off > optlen - sizeof(struct in_addr)) 954 break; 955 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 956 sizeof(ipaddr.sin_addr)); 957 /* 958 * locate outgoing interface; if we're the destination, 959 * use the incoming interface (should be same). 960 */ 961 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 962 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 963 type = ICMP_UNREACH; 964 code = ICMP_UNREACH_HOST; 965 goto bad; 966 } 967 bcopy((caddr_t)&ia->ia_addr.sin_addr, 968 (caddr_t)(cp + off), sizeof(struct in_addr)); 969 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 970 break; 971 972 case IPOPT_TS: 973 code = cp - (u_char *)ip; 974 ipt = (struct ip_timestamp *)cp; 975 if (ipt->ipt_len < 5) 976 goto bad; 977 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 978 if (++ipt->ipt_oflw == 0) 979 goto bad; 980 break; 981 } 982 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 983 switch (ipt->ipt_flg) { 984 985 case IPOPT_TS_TSONLY: 986 break; 987 988 case IPOPT_TS_TSANDADDR: 989 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 990 sizeof(struct in_addr) > ipt->ipt_len) 991 goto bad; 992 ipaddr.sin_addr = dst; 993 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 994 m->m_pkthdr.rcvif); 995 if (ia == 0) 996 continue; 997 bcopy((caddr_t)&ia->ia_addr.sin_addr, 998 (caddr_t)sin, sizeof(struct in_addr)); 999 ipt->ipt_ptr += sizeof(struct in_addr); 1000 break; 1001 1002 case IPOPT_TS_PRESPEC: 1003 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1004 sizeof(struct in_addr) > ipt->ipt_len) 1005 goto bad; 1006 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 1007 sizeof(struct in_addr)); 1008 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1009 continue; 1010 ipt->ipt_ptr += sizeof(struct in_addr); 1011 break; 1012 1013 default: 1014 goto bad; 1015 } 1016 ntime = iptime(); 1017 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1018 sizeof(n_time)); 1019 ipt->ipt_ptr += sizeof(n_time); 1020 } 1021 } 1022 if (forward) { 1023 if (ip_forwsrcrt == 0) { 1024 type = ICMP_UNREACH; 1025 code = ICMP_UNREACH_SRCFAIL; 1026 goto bad; 1027 } 1028 ip_forward(m, 1); 1029 return (1); 1030 } 1031 return (0); 1032bad: 1033 icmp_error(m, type, code, 0, 0); 1034 ipstat.ips_badoptions++; 1035 return (1); 1036} 1037 1038/* 1039 * Given address of next destination (final or next hop), 1040 * return internet address info of interface to be used to get there. 1041 */ 1042struct in_ifaddr * 1043ip_rtaddr(dst) 1044 struct in_addr dst; 1045{ 1046 register struct sockaddr_in *sin; 1047 1048 sin = satosin(&ipforward_rt.ro_dst); 1049 1050 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1051 if (ipforward_rt.ro_rt) { 1052 RTFREE(ipforward_rt.ro_rt); 1053 ipforward_rt.ro_rt = 0; 1054 } 1055 sin->sin_family = AF_INET; 1056 sin->sin_len = sizeof(*sin); 1057 sin->sin_addr = dst; 1058 1059 rtalloc(&ipforward_rt); 1060 } 1061 if (ipforward_rt.ro_rt == 0) 1062 return ((struct in_ifaddr *)0); 1063 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1064} 1065 1066/* 1067 * Save incoming source route for use in replies, 1068 * to be picked up later by ip_srcroute if the receiver is interested. 1069 */ 1070void 1071save_rte(option, dst) 1072 u_char *option; 1073 struct in_addr dst; 1074{ 1075 unsigned olen; 1076 1077 olen = option[IPOPT_OLEN]; 1078#ifdef DIAGNOSTIC 1079 if (ipprintfs) 1080 printf("save_rte: olen %d\n", olen); 1081#endif 1082 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1083 return; 1084 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1085 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1086 ip_srcrt.dst = dst; 1087} 1088 1089/* 1090 * Retrieve incoming source route for use in replies, 1091 * in the same form used by setsockopt. 1092 * The first hop is placed before the options, will be removed later. 1093 */ 1094struct mbuf * 1095ip_srcroute() 1096{ 1097 register struct in_addr *p, *q; 1098 register struct mbuf *m; 1099 1100 if (ip_nhops == 0) 1101 return ((struct mbuf *)0); 1102 m = m_get(M_DONTWAIT, MT_SOOPTS); 1103 if (m == 0) 1104 return ((struct mbuf *)0); 1105 1106#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1107 1108 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1109 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1110 OPTSIZ; 1111#ifdef DIAGNOSTIC 1112 if (ipprintfs) 1113 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1114#endif 1115 1116 /* 1117 * First save first hop for return route 1118 */ 1119 p = &ip_srcrt.route[ip_nhops - 1]; 1120 *(mtod(m, struct in_addr *)) = *p--; 1121#ifdef DIAGNOSTIC 1122 if (ipprintfs) 1123 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1124#endif 1125 1126 /* 1127 * Copy option fields and padding (nop) to mbuf. 1128 */ 1129 ip_srcrt.nop = IPOPT_NOP; 1130 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1131 bcopy((caddr_t)&ip_srcrt.nop, 1132 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1133 q = (struct in_addr *)(mtod(m, caddr_t) + 1134 sizeof(struct in_addr) + OPTSIZ); 1135#undef OPTSIZ 1136 /* 1137 * Record return path as an IP source route, 1138 * reversing the path (pointers are now aligned). 1139 */ 1140 while (p >= ip_srcrt.route) { 1141#ifdef DIAGNOSTIC 1142 if (ipprintfs) 1143 printf(" %x", ntohl(q->s_addr)); 1144#endif 1145 *q++ = *p--; 1146 } 1147 /* 1148 * Last hop goes to final destination. 1149 */ 1150 *q = ip_srcrt.dst; 1151#ifdef DIAGNOSTIC 1152 if (ipprintfs) 1153 printf(" %x\n", ntohl(q->s_addr)); 1154#endif 1155 return (m); 1156} 1157 1158/* 1159 * Strip out IP options, at higher 1160 * level protocol in the kernel. 1161 * Second argument is buffer to which options 1162 * will be moved, and return value is their length. 1163 * XXX should be deleted; last arg currently ignored. 1164 */ 1165void 1166ip_stripoptions(m, mopt) 1167 register struct mbuf *m; 1168 struct mbuf *mopt; 1169{ 1170 register int i; 1171 struct ip *ip = mtod(m, struct ip *); 1172 register caddr_t opts; 1173 int olen; 1174 1175 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1176 opts = (caddr_t)(ip + 1); 1177 i = m->m_len - (sizeof (struct ip) + olen); 1178 bcopy(opts + olen, opts, (unsigned)i); 1179 m->m_len -= olen; 1180 if (m->m_flags & M_PKTHDR) 1181 m->m_pkthdr.len -= olen; 1182 ip->ip_len -= olen; 1183 ip->ip_hl = sizeof (struct ip) >> 2; 1184} 1185 1186int inetctlerrmap[PRC_NCMDS] = { 1187 0, 0, 0, 0, 1188 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1189 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1190 EMSGSIZE, EHOSTUNREACH, 0, 0, 1191 0, 0, 0, 0, 1192 ENOPROTOOPT 1193}; 1194 1195/* 1196 * Forward a packet. If some error occurs return the sender 1197 * an icmp packet. Note we can't always generate a meaningful 1198 * icmp message because icmp doesn't have a large enough repertoire 1199 * of codes and types. 1200 * 1201 * If not forwarding, just drop the packet. This could be confusing 1202 * if ipforwarding was zero but some routing protocol was advancing 1203 * us as a gateway to somewhere. However, we must let the routing 1204 * protocol deal with that. 1205 * 1206 * The srcrt parameter indicates whether the packet is being forwarded 1207 * via a source route. 1208 */ 1209void 1210ip_forward(m, srcrt) 1211 struct mbuf *m; 1212 int srcrt; 1213{ 1214 register struct ip *ip = mtod(m, struct ip *); 1215 register struct sockaddr_in *sin; 1216 register struct rtentry *rt; 1217 int error, type = 0, code = 0; 1218 struct mbuf *mcopy; 1219 n_long dest; 1220 struct ifnet *destifp; 1221 1222 dest = 0; 1223#ifdef DIAGNOSTIC 1224 if (ipprintfs) 1225 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1226 ntohl(ip->ip_src.s_addr), 1227 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1228#endif 1229 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1230 ipstat.ips_cantforward++; 1231 m_freem(m); 1232 return; 1233 } 1234 if (ip->ip_ttl <= IPTTLDEC) { 1235 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1236 return; 1237 } 1238 ip->ip_ttl -= IPTTLDEC; 1239 1240 sin = satosin(&ipforward_rt.ro_dst); 1241 if ((rt = ipforward_rt.ro_rt) == 0 || 1242 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1243 if (ipforward_rt.ro_rt) { 1244 RTFREE(ipforward_rt.ro_rt); 1245 ipforward_rt.ro_rt = 0; 1246 } 1247 sin->sin_family = AF_INET; 1248 sin->sin_len = sizeof(struct sockaddr_in); 1249 sin->sin_addr = ip->ip_dst; 1250 1251 rtalloc(&ipforward_rt); 1252 if (ipforward_rt.ro_rt == 0) { 1253 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1254 return; 1255 } 1256 rt = ipforward_rt.ro_rt; 1257 } 1258 1259 /* 1260 * Save at most 68 bytes of the packet in case 1261 * we need to generate an ICMP message to the src. 1262 */ 1263 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1264 1265 /* 1266 * If forwarding packet using same interface that it came in on, 1267 * perhaps should send a redirect to sender to shortcut a hop. 1268 * Only send redirect if source is sending directly to us, 1269 * and if packet was not source routed (or has any options). 1270 * Also, don't send redirect if forwarding using a default route 1271 * or a route modified by a redirect. 1272 */ 1273 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1274 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1275 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1276 ipsendredirects && !srcrt) { 1277 if (rt->rt_ifa && 1278 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1279 ifatoia(rt->rt_ifa)->ia_subnet) { 1280 if (rt->rt_flags & RTF_GATEWAY) 1281 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1282 else 1283 dest = ip->ip_dst.s_addr; 1284 /* 1285 * Router requirements says to only send host 1286 * redirects. 1287 */ 1288 type = ICMP_REDIRECT; 1289 code = ICMP_REDIRECT_HOST; 1290#ifdef DIAGNOSTIC 1291 if (ipprintfs) 1292 printf("redirect (%d) to %x\n", code, 1293 (u_int32_t)dest); 1294#endif 1295 } 1296 } 1297 1298 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1299 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1300 if (error) 1301 ipstat.ips_cantforward++; 1302 else { 1303 ipstat.ips_forward++; 1304 if (type) 1305 ipstat.ips_redirectsent++; 1306 else { 1307 if (mcopy) { 1308#ifdef GATEWAY 1309 if (mcopy->m_flags & M_CANFASTFWD) 1310 ipflow_create(&ipforward_rt, mcopy); 1311#endif 1312 m_freem(mcopy); 1313 } 1314 return; 1315 } 1316 } 1317 if (mcopy == NULL) 1318 return; 1319 destifp = NULL; 1320 1321 switch (error) { 1322 1323 case 0: /* forwarded, but need redirect */ 1324 /* type, code set above */ 1325 break; 1326 1327 case ENETUNREACH: /* shouldn't happen, checked above */ 1328 case EHOSTUNREACH: 1329 case ENETDOWN: 1330 case EHOSTDOWN: 1331 default: 1332 type = ICMP_UNREACH; 1333 code = ICMP_UNREACH_HOST; 1334 break; 1335 1336 case EMSGSIZE: 1337 type = ICMP_UNREACH; 1338 code = ICMP_UNREACH_NEEDFRAG; 1339 if (ipforward_rt.ro_rt) 1340 destifp = ipforward_rt.ro_rt->rt_ifp; 1341 ipstat.ips_cantfrag++; 1342 break; 1343 1344 case ENOBUFS: 1345 type = ICMP_SOURCEQUENCH; 1346 code = 0; 1347 break; 1348 } 1349 icmp_error(mcopy, type, code, dest, destifp); 1350} 1351 1352void 1353ip_savecontrol(inp, mp, ip, m) 1354 register struct inpcb *inp; 1355 register struct mbuf **mp; 1356 register struct ip *ip; 1357 register struct mbuf *m; 1358{ 1359 1360 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1361 struct timeval tv; 1362 1363 microtime(&tv); 1364 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1365 SCM_TIMESTAMP, SOL_SOCKET); 1366 if (*mp) 1367 mp = &(*mp)->m_next; 1368 } 1369 if (inp->inp_flags & INP_RECVDSTADDR) { 1370 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1371 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1372 if (*mp) 1373 mp = &(*mp)->m_next; 1374 } 1375#ifdef notyet 1376 /* 1377 * XXX 1378 * Moving these out of udp_input() made them even more broken 1379 * than they already were. 1380 * - fenner@parc.xerox.com 1381 */ 1382 /* options were tossed already */ 1383 if (inp->inp_flags & INP_RECVOPTS) { 1384 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1385 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1386 if (*mp) 1387 mp = &(*mp)->m_next; 1388 } 1389 /* ip_srcroute doesn't do what we want here, need to fix */ 1390 if (inp->inp_flags & INP_RECVRETOPTS) { 1391 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1392 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1393 if (*mp) 1394 mp = &(*mp)->m_next; 1395 } 1396#endif 1397 if (inp->inp_flags & INP_RECVIF) { 1398 struct sockaddr_dl sdl; 1399 1400 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1401 sdl.sdl_family = AF_LINK; 1402 sdl.sdl_index = m->m_pkthdr.rcvif ? 1403 m->m_pkthdr.rcvif->if_index : 0; 1404 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1405 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1406 IP_RECVIF, IPPROTO_IP); 1407 if (*mp) 1408 mp = &(*mp)->m_next; 1409 } 1410} 1411 1412int 1413ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1414 int *name; 1415 u_int namelen; 1416 void *oldp; 1417 size_t *oldlenp; 1418 void *newp; 1419 size_t newlen; 1420{ 1421 extern int subnetsarelocal; 1422 1423 int error, old; 1424 1425 /* All sysctl names at this level are terminal. */ 1426 if (namelen != 1) 1427 return (ENOTDIR); 1428 1429 switch (name[0]) { 1430 case IPCTL_FORWARDING: 1431 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1432 case IPCTL_SENDREDIRECTS: 1433 return (sysctl_int(oldp, oldlenp, newp, newlen, 1434 &ipsendredirects)); 1435 case IPCTL_DEFTTL: 1436 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1437#ifdef notyet 1438 case IPCTL_DEFMTU: 1439 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1440#endif 1441 case IPCTL_FORWSRCRT: 1442 /* Don't allow this to change in a secure environment. */ 1443 if (securelevel > 0) 1444 return (sysctl_rdint(oldp, oldlenp, newp, 1445 ip_forwsrcrt)); 1446 else 1447 return (sysctl_int(oldp, oldlenp, newp, newlen, 1448 &ip_forwsrcrt)); 1449 case IPCTL_DIRECTEDBCAST: 1450 return (sysctl_int(oldp, oldlenp, newp, newlen, 1451 &ip_directedbcast)); 1452 case IPCTL_ALLOWSRCRT: 1453 return (sysctl_int(oldp, oldlenp, newp, newlen, 1454 &ip_allowsrcrt)); 1455 case IPCTL_SUBNETSARELOCAL: 1456 return (sysctl_int(oldp, oldlenp, newp, newlen, 1457 &subnetsarelocal)); 1458 case IPCTL_MTUDISC: 1459 error = sysctl_int(oldp, oldlenp, newp, newlen, 1460 &ip_mtudisc); 1461 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1462 ip_mtudisc_timeout_q = 1463 rt_timer_queue_create(ip_mtudisc_timeout); 1464 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1465 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1466 ip_mtudisc_timeout_q = NULL; 1467 } 1468 return error; 1469 case IPCTL_ANONPORTMIN: 1470 old = anonportmin; 1471 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1472 if (anonportmin >= anonportmax || anonportmin > 65535 1473#ifndef IPNOPRIVPORTS 1474 || anonportmin < IPPORT_RESERVED 1475#endif 1476 ) { 1477 anonportmin = old; 1478 return (EINVAL); 1479 } 1480 return (error); 1481 case IPCTL_ANONPORTMAX: 1482 old = anonportmax; 1483 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1484 if (anonportmin >= anonportmax || anonportmax > 65535 1485#ifndef IPNOPRIVPORTS 1486 || anonportmax < IPPORT_RESERVED 1487#endif 1488 ) { 1489 anonportmax = old; 1490 return (EINVAL); 1491 } 1492 return (error); 1493 case IPCTL_MTUDISCTIMEOUT: 1494 error = sysctl_int(oldp, oldlenp, newp, newlen, 1495 &ip_mtudisc_timeout); 1496 if (ip_mtudisc_timeout_q != NULL) 1497 rt_timer_queue_change(ip_mtudisc_timeout_q, 1498 ip_mtudisc_timeout); 1499 return (error); 1500#ifdef GATEWAY 1501 case IPCTL_MAXFLOWS: 1502 { 1503 int s; 1504 1505 error = sysctl_int(oldp, oldlenp, newp, newlen, 1506 &ip_maxflows); 1507 s = splsoftnet(); 1508 ipflow_reap(0); 1509 splx(s); 1510 return (error); 1511 } 1512#endif 1513 default: 1514 return (EOPNOTSUPP); 1515 } 1516 /* NOTREACHED */ 1517} 1518