ip_input.c revision 1.82.2.1
1 /* $NetBSD: ip_input.c,v 1.82.2.1 1999/04/07 23:20:42 proff Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 73 */ 74 75 #include "opt_gateway.h" 76 #include "opt_pfil_hooks.h" 77 #include "opt_mrouting.h" 78 79 #include <sys/param.h> 80 #include <sys/systm.h> 81 #include <sys/malloc.h> 82 #include <sys/mbuf.h> 83 #include <sys/domain.h> 84 #include <sys/protosw.h> 85 #include <sys/socket.h> 86 #include <sys/socketvar.h> 87 #include <sys/errno.h> 88 #include <sys/time.h> 89 #include <sys/kernel.h> 90 #include <sys/proc.h> 91 #include <sys/pool.h> 92 93 #include <vm/vm.h> 94 #include <sys/sysctl.h> 95 96 #include <net/if.h> 97 #include <net/if_dl.h> 98 #include <net/route.h> 99 #include <net/pfil.h> 100 101 #include <netinet/in.h> 102 #include <netinet/in_systm.h> 103 #include <netinet/ip.h> 104 #include <netinet/in_pcb.h> 105 #include <netinet/in_var.h> 106 #include <netinet/ip_var.h> 107 #include <netinet/ip_icmp.h> 108 109 #ifndef IPFORWARDING 110 #ifdef GATEWAY 111 #define IPFORWARDING 1 /* forward IP packets not for us */ 112 #else /* GATEWAY */ 113 #define IPFORWARDING 0 /* don't forward IP packets not for us */ 114 #endif /* GATEWAY */ 115 #endif /* IPFORWARDING */ 116 #ifndef IPSENDREDIRECTS 117 #define IPSENDREDIRECTS 1 118 #endif 119 #ifndef IPFORWSRCRT 120 #define IPFORWSRCRT 1 /* forward source-routed packets */ 121 #endif 122 #ifndef IPALLOWSRCRT 123 #define IPALLOWSRCRT 1 /* allow source-routed packets */ 124 #endif 125 #ifndef IPMTUDISC 126 #define IPMTUDISC 0 127 #endif 128 #ifndef IPMTUDISCTIMEOUT 129 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */ 130 #endif 131 132 /* 133 * Note: DIRECTED_BROADCAST is handled this way so that previous 134 * configuration using this option will Just Work. 135 */ 136 #ifndef IPDIRECTEDBCAST 137 #ifdef DIRECTED_BROADCAST 138 #define IPDIRECTEDBCAST 1 139 #else 140 #define IPDIRECTEDBCAST 0 141 #endif /* DIRECTED_BROADCAST */ 142 #endif /* IPDIRECTEDBCAST */ 143 int ipforwarding = IPFORWARDING; 144 int ipsendredirects = IPSENDREDIRECTS; 145 int ip_defttl = IPDEFTTL; 146 int ip_forwsrcrt = IPFORWSRCRT; 147 int ip_directedbcast = IPDIRECTEDBCAST; 148 int ip_allowsrcrt = IPALLOWSRCRT; 149 int ip_mtudisc = IPMTUDISC; 150 u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT; 151 #ifdef DIAGNOSTIC 152 int ipprintfs = 0; 153 #endif 154 155 struct rttimer_queue *ip_mtudisc_timeout_q = NULL; 156 157 extern struct domain inetdomain; 158 extern struct protosw inetsw[]; 159 u_char ip_protox[IPPROTO_MAX]; 160 int ipqmaxlen = IFQ_MAXLEN; 161 struct in_ifaddrhead in_ifaddr; 162 struct in_ifaddrhashhead *in_ifaddrhashtbl; 163 struct ifqueue ipintrq; 164 struct ipstat ipstat; 165 u_int16_t ip_id; 166 int ip_defttl; 167 168 struct ipqhead ipq; 169 int ipq_locked; 170 171 static __inline int ipq_lock_try __P((void)); 172 static __inline void ipq_unlock __P((void)); 173 174 static __inline int 175 ipq_lock_try() 176 { 177 int s; 178 179 s = splimp(); 180 if (ipq_locked) { 181 splx(s); 182 return (0); 183 } 184 ipq_locked = 1; 185 splx(s); 186 return (1); 187 } 188 189 static __inline void 190 ipq_unlock() 191 { 192 int s; 193 194 s = splimp(); 195 ipq_locked = 0; 196 splx(s); 197 } 198 199 #ifdef DIAGNOSTIC 200 #define IPQ_LOCK() \ 201 do { \ 202 if (ipq_lock_try() == 0) { \ 203 printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \ 204 panic("ipq_lock"); \ 205 } \ 206 } while (0) 207 #define IPQ_LOCK_CHECK() \ 208 do { \ 209 if (ipq_locked == 0) { \ 210 printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \ 211 panic("ipq lock check"); \ 212 } \ 213 } while (0) 214 #else 215 #define IPQ_LOCK() (void) ipq_lock_try() 216 #define IPQ_LOCK_CHECK() /* nothing */ 217 #endif 218 219 #define IPQ_UNLOCK() ipq_unlock() 220 221 struct pool ipqent_pool; 222 223 /* 224 * We need to save the IP options in case a protocol wants to respond 225 * to an incoming packet over the same route if the packet got here 226 * using IP source routing. This allows connection establishment and 227 * maintenance when the remote end is on a network that is not known 228 * to us. 229 */ 230 int ip_nhops = 0; 231 static struct ip_srcrt { 232 struct in_addr dst; /* final destination */ 233 char nop; /* one NOP to align */ 234 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 235 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 236 } ip_srcrt; 237 238 static void save_rte __P((u_char *, struct in_addr)); 239 240 /* 241 * IP initialization: fill in IP protocol switch table. 242 * All protocols not implemented in kernel go to raw IP protocol handler. 243 */ 244 void 245 ip_init() 246 { 247 register struct protosw *pr; 248 register int i; 249 250 pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl", 251 0, NULL, NULL, M_IPQ); 252 253 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 254 if (pr == 0) 255 panic("ip_init"); 256 for (i = 0; i < IPPROTO_MAX; i++) 257 ip_protox[i] = pr - inetsw; 258 for (pr = inetdomain.dom_protosw; 259 pr < inetdomain.dom_protoswNPROTOSW; pr++) 260 if (pr->pr_domain->dom_family == PF_INET && 261 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 262 ip_protox[pr->pr_protocol] = pr - inetsw; 263 LIST_INIT(&ipq); 264 ip_id = time.tv_sec & 0xffff; 265 ipintrq.ifq_maxlen = ipqmaxlen; 266 TAILQ_INIT(&in_ifaddr); 267 in_ifaddrhashtbl = 268 hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash); 269 if (ip_mtudisc != 0) 270 ip_mtudisc_timeout_q = 271 rt_timer_queue_create(ip_mtudisc_timeout); 272 #ifdef GATEWAY 273 ipflow_init(); 274 #endif 275 } 276 277 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 278 struct route ipforward_rt; 279 280 /* 281 * Ip input routine. Checksum and byte swap header. If fragmented 282 * try to reassemble. Process options. Pass to next level. 283 */ 284 void 285 ipintr() 286 { 287 register struct ip *ip = NULL; 288 register struct mbuf *m; 289 register struct ipq *fp; 290 register struct in_ifaddr *ia; 291 register struct ifaddr *ifa; 292 struct ipqent *ipqe; 293 int hlen = 0, mff, len, s; 294 #ifdef PFIL_HOOKS 295 struct packet_filter_hook *pfh; 296 struct mbuf *m0; 297 int rv; 298 #endif /* PFIL_HOOKS */ 299 300 next: 301 /* 302 * Get next datagram off input queue and get IP header 303 * in first mbuf. 304 */ 305 s = splimp(); 306 IF_DEQUEUE(&ipintrq, m); 307 splx(s); 308 if (m == 0) 309 return; 310 #ifdef DIAGNOSTIC 311 if ((m->m_flags & M_PKTHDR) == 0) 312 panic("ipintr no HDR"); 313 #endif 314 /* 315 * If no IP addresses have been set yet but the interfaces 316 * are receiving, can't do anything with incoming packets yet. 317 */ 318 if (in_ifaddr.tqh_first == 0) 319 goto bad; 320 ipstat.ips_total++; 321 if (m->m_len < sizeof (struct ip) && 322 (m = m_pullup(m, sizeof (struct ip))) == 0) { 323 ipstat.ips_toosmall++; 324 goto next; 325 } 326 ip = mtod(m, struct ip *); 327 if (ip->ip_v != IPVERSION) { 328 ipstat.ips_badvers++; 329 goto bad; 330 } 331 hlen = ip->ip_hl << 2; 332 if (hlen < sizeof(struct ip)) { /* minimum header length */ 333 ipstat.ips_badhlen++; 334 goto bad; 335 } 336 if (hlen > m->m_len) { 337 if ((m = m_pullup(m, hlen)) == 0) { 338 ipstat.ips_badhlen++; 339 goto next; 340 } 341 ip = mtod(m, struct ip *); 342 } 343 if (in_cksum(m, hlen) != 0) { 344 ipstat.ips_badsum++; 345 goto bad; 346 } 347 348 /* 349 * Convert fields to host representation. 350 */ 351 NTOHS(ip->ip_len); 352 NTOHS(ip->ip_off); 353 len = ip->ip_len; 354 355 /* 356 * Check 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) { 424 if (ia->ia_ifp->if_flags & IFF_UP) 425 goto ours; 426 } 427 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 428 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 429 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 430 if (ifa->ifa_addr->sa_family != AF_INET) continue; 431 ia = ifatoia(ifa); 432 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 433 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 434 /* 435 * Look for all-0's host part (old broadcast addr), 436 * either for subnet or net. 437 */ 438 ip->ip_dst.s_addr == ia->ia_subnet || 439 ip->ip_dst.s_addr == ia->ia_net) 440 goto ours; 441 /* 442 * An interface with IP address zero accepts 443 * all packets that arrive on that interface. 444 */ 445 if (in_nullhost(ia->ia_addr.sin_addr)) 446 goto ours; 447 } 448 } 449 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 450 struct in_multi *inm; 451 #ifdef MROUTING 452 extern struct socket *ip_mrouter; 453 454 if (m->m_flags & M_EXT) { 455 if ((m = m_pullup(m, hlen)) == 0) { 456 ipstat.ips_toosmall++; 457 goto next; 458 } 459 ip = mtod(m, struct ip *); 460 } 461 462 if (ip_mrouter) { 463 /* 464 * If we are acting as a multicast router, all 465 * incoming multicast packets are passed to the 466 * kernel-level multicast forwarding function. 467 * The packet is returned (relatively) intact; if 468 * ip_mforward() returns a non-zero value, the packet 469 * must be discarded, else it may be accepted below. 470 * 471 * (The IP ident field is put in the same byte order 472 * as expected when ip_mforward() is called from 473 * ip_output().) 474 */ 475 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 476 ipstat.ips_cantforward++; 477 m_freem(m); 478 goto next; 479 } 480 481 /* 482 * The process-level routing demon needs to receive 483 * all multicast IGMP packets, whether or not this 484 * host belongs to their destination groups. 485 */ 486 if (ip->ip_p == IPPROTO_IGMP) 487 goto ours; 488 ipstat.ips_forward++; 489 } 490 #endif 491 /* 492 * See if we belong to the destination multicast group on the 493 * arrival interface. 494 */ 495 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 496 if (inm == NULL) { 497 ipstat.ips_cantforward++; 498 m_freem(m); 499 goto next; 500 } 501 goto ours; 502 } 503 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 504 in_nullhost(ip->ip_dst)) 505 goto ours; 506 507 /* 508 * Not for us; forward if possible and desirable. 509 */ 510 if (ipforwarding == 0) { 511 ipstat.ips_cantforward++; 512 m_freem(m); 513 } else 514 ip_forward(m, 0); 515 goto next; 516 517 ours: 518 /* 519 * If offset or IP_MF are set, must reassemble. 520 * Otherwise, nothing need be done. 521 * (We could look in the reassembly queue to see 522 * if the packet was previously fragmented, 523 * but it's not worth the time; just let them time out.) 524 */ 525 if (ip->ip_off & ~(IP_DF|IP_RF)) { 526 /* 527 * Look for queue of fragments 528 * of this datagram. 529 */ 530 IPQ_LOCK(); 531 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 532 if (ip->ip_id == fp->ipq_id && 533 in_hosteq(ip->ip_src, fp->ipq_src) && 534 in_hosteq(ip->ip_dst, fp->ipq_dst) && 535 ip->ip_p == fp->ipq_p) 536 goto found; 537 fp = 0; 538 found: 539 540 /* 541 * Adjust ip_len to not reflect header, 542 * set ipqe_mff if more fragments are expected, 543 * convert offset of this to bytes. 544 */ 545 ip->ip_len -= hlen; 546 mff = (ip->ip_off & IP_MF) != 0; 547 if (mff) { 548 /* 549 * Make sure that fragments have a data length 550 * that's a non-zero multiple of 8 bytes. 551 */ 552 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 553 ipstat.ips_badfrags++; 554 IPQ_UNLOCK(); 555 goto bad; 556 } 557 } 558 ip->ip_off <<= 3; 559 560 /* 561 * If datagram marked as having more fragments 562 * or if this is not the first fragment, 563 * attempt reassembly; if it succeeds, proceed. 564 */ 565 if (mff || ip->ip_off) { 566 ipstat.ips_fragments++; 567 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 568 if (ipqe == NULL) { 569 ipstat.ips_rcvmemdrop++; 570 IPQ_UNLOCK(); 571 goto bad; 572 } 573 ipqe->ipqe_mff = mff; 574 ipqe->ipqe_m = m; 575 ipqe->ipqe_ip = ip; 576 m = ip_reass(ipqe, fp); 577 if (m == 0) { 578 IPQ_UNLOCK(); 579 goto next; 580 } 581 ipstat.ips_reassembled++; 582 ip = mtod(m, struct ip *); 583 hlen = ip->ip_hl << 2; 584 ip->ip_len += hlen; 585 } else 586 if (fp) 587 ip_freef(fp); 588 IPQ_UNLOCK(); 589 } 590 591 /* 592 * Switch out to protocol's input routine. 593 */ 594 #if IFA_STATS 595 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len; 596 #endif 597 ipstat.ips_delivered++; 598 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 599 goto next; 600 bad: 601 m_freem(m); 602 goto next; 603 } 604 605 /* 606 * Take incoming datagram fragment and try to 607 * reassemble it into whole datagram. If a chain for 608 * reassembly of this datagram already exists, then it 609 * is given as fp; otherwise have to make a chain. 610 */ 611 struct mbuf * 612 ip_reass(ipqe, fp) 613 register struct ipqent *ipqe; 614 register struct ipq *fp; 615 { 616 register struct mbuf *m = ipqe->ipqe_m; 617 register struct ipqent *nq, *p, *q; 618 struct ip *ip; 619 struct mbuf *t; 620 int hlen = ipqe->ipqe_ip->ip_hl << 2; 621 int i, next; 622 623 IPQ_LOCK_CHECK(); 624 625 /* 626 * Presence of header sizes in mbufs 627 * would confuse code below. 628 */ 629 m->m_data += hlen; 630 m->m_len -= hlen; 631 632 /* 633 * If first fragment to arrive, create a reassembly queue. 634 */ 635 if (fp == 0) { 636 MALLOC(fp, struct ipq *, sizeof (struct ipq), 637 M_FTABLE, M_NOWAIT); 638 if (fp == NULL) 639 goto dropfrag; 640 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 641 fp->ipq_ttl = IPFRAGTTL; 642 fp->ipq_p = ipqe->ipqe_ip->ip_p; 643 fp->ipq_id = ipqe->ipqe_ip->ip_id; 644 LIST_INIT(&fp->ipq_fragq); 645 fp->ipq_src = ipqe->ipqe_ip->ip_src; 646 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 647 p = NULL; 648 goto insert; 649 } 650 651 /* 652 * Find a segment which begins after this one does. 653 */ 654 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 655 p = q, q = q->ipqe_q.le_next) 656 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 657 break; 658 659 /* 660 * If there is a preceding segment, it may provide some of 661 * our data already. If so, drop the data from the incoming 662 * segment. If it provides all of our data, drop us. 663 */ 664 if (p != NULL) { 665 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 666 ipqe->ipqe_ip->ip_off; 667 if (i > 0) { 668 if (i >= ipqe->ipqe_ip->ip_len) 669 goto dropfrag; 670 m_adj(ipqe->ipqe_m, i); 671 ipqe->ipqe_ip->ip_off += i; 672 ipqe->ipqe_ip->ip_len -= i; 673 } 674 } 675 676 /* 677 * While we overlap succeeding segments trim them or, 678 * if they are completely covered, dequeue them. 679 */ 680 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 681 q->ipqe_ip->ip_off; q = nq) { 682 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 683 q->ipqe_ip->ip_off; 684 if (i < q->ipqe_ip->ip_len) { 685 q->ipqe_ip->ip_len -= i; 686 q->ipqe_ip->ip_off += i; 687 m_adj(q->ipqe_m, i); 688 break; 689 } 690 nq = q->ipqe_q.le_next; 691 m_freem(q->ipqe_m); 692 LIST_REMOVE(q, ipqe_q); 693 pool_put(&ipqent_pool, q); 694 } 695 696 insert: 697 /* 698 * Stick new segment in its place; 699 * check for complete reassembly. 700 */ 701 if (p == NULL) { 702 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 703 } else { 704 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 705 } 706 next = 0; 707 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 708 p = q, q = q->ipqe_q.le_next) { 709 if (q->ipqe_ip->ip_off != next) 710 return (0); 711 next += q->ipqe_ip->ip_len; 712 } 713 if (p->ipqe_mff) 714 return (0); 715 716 /* 717 * Reassembly is complete. Check for a bogus message size and 718 * concatenate fragments. 719 */ 720 q = fp->ipq_fragq.lh_first; 721 ip = q->ipqe_ip; 722 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 723 ipstat.ips_toolong++; 724 ip_freef(fp); 725 return (0); 726 } 727 m = q->ipqe_m; 728 t = m->m_next; 729 m->m_next = 0; 730 m_cat(m, t); 731 nq = q->ipqe_q.le_next; 732 pool_put(&ipqent_pool, q); 733 for (q = nq; q != NULL; q = nq) { 734 t = q->ipqe_m; 735 nq = q->ipqe_q.le_next; 736 pool_put(&ipqent_pool, q); 737 m_cat(m, t); 738 } 739 740 /* 741 * Create header for new ip packet by 742 * modifying header of first packet; 743 * dequeue and discard fragment reassembly header. 744 * Make header visible. 745 */ 746 ip->ip_len = next; 747 ip->ip_src = fp->ipq_src; 748 ip->ip_dst = fp->ipq_dst; 749 LIST_REMOVE(fp, ipq_q); 750 FREE(fp, M_FTABLE); 751 m->m_len += (ip->ip_hl << 2); 752 m->m_data -= (ip->ip_hl << 2); 753 /* some debugging cruft by sklower, below, will go away soon */ 754 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 755 register int plen = 0; 756 for (t = m; t; t = t->m_next) 757 plen += t->m_len; 758 m->m_pkthdr.len = plen; 759 } 760 return (m); 761 762 dropfrag: 763 ipstat.ips_fragdropped++; 764 m_freem(m); 765 pool_put(&ipqent_pool, ipqe); 766 return (0); 767 } 768 769 /* 770 * Free a fragment reassembly header and all 771 * associated datagrams. 772 */ 773 void 774 ip_freef(fp) 775 struct ipq *fp; 776 { 777 register struct ipqent *q, *p; 778 779 IPQ_LOCK_CHECK(); 780 781 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 782 p = q->ipqe_q.le_next; 783 m_freem(q->ipqe_m); 784 LIST_REMOVE(q, ipqe_q); 785 pool_put(&ipqent_pool, q); 786 } 787 LIST_REMOVE(fp, ipq_q); 788 FREE(fp, M_FTABLE); 789 } 790 791 /* 792 * IP timer processing; 793 * if a timer expires on a reassembly 794 * queue, discard it. 795 */ 796 void 797 ip_slowtimo() 798 { 799 register struct ipq *fp, *nfp; 800 int s = splsoftnet(); 801 802 IPQ_LOCK(); 803 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 804 nfp = fp->ipq_q.le_next; 805 if (--fp->ipq_ttl == 0) { 806 ipstat.ips_fragtimeout++; 807 ip_freef(fp); 808 } 809 } 810 IPQ_UNLOCK(); 811 #ifdef GATEWAY 812 ipflow_slowtimo(); 813 #endif 814 splx(s); 815 } 816 817 /* 818 * Drain off all datagram fragments. 819 */ 820 void 821 ip_drain() 822 { 823 824 /* 825 * We may be called from a device's interrupt context. If 826 * the ipq is already busy, just bail out now. 827 */ 828 if (ipq_lock_try() == 0) 829 return; 830 831 while (ipq.lh_first != NULL) { 832 ipstat.ips_fragdropped++; 833 ip_freef(ipq.lh_first); 834 } 835 836 IPQ_UNLOCK(); 837 } 838 839 /* 840 * Do option processing on a datagram, 841 * possibly discarding it if bad options are encountered, 842 * or forwarding it if source-routed. 843 * Returns 1 if packet has been forwarded/freed, 844 * 0 if the packet should be processed further. 845 */ 846 int 847 ip_dooptions(m) 848 struct mbuf *m; 849 { 850 register struct ip *ip = mtod(m, struct ip *); 851 register u_char *cp; 852 register struct ip_timestamp *ipt; 853 register struct in_ifaddr *ia; 854 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 855 struct in_addr *sin, dst; 856 n_time ntime; 857 858 dst = ip->ip_dst; 859 cp = (u_char *)(ip + 1); 860 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 861 for (; cnt > 0; cnt -= optlen, cp += optlen) { 862 opt = cp[IPOPT_OPTVAL]; 863 if (opt == IPOPT_EOL) 864 break; 865 if (opt == IPOPT_NOP) 866 optlen = 1; 867 else { 868 optlen = cp[IPOPT_OLEN]; 869 if (optlen <= 0 || optlen > cnt) { 870 code = &cp[IPOPT_OLEN] - (u_char *)ip; 871 goto bad; 872 } 873 } 874 switch (opt) { 875 876 default: 877 break; 878 879 /* 880 * Source routing with record. 881 * Find interface with current destination address. 882 * If none on this machine then drop if strictly routed, 883 * or do nothing if loosely routed. 884 * Record interface address and bring up next address 885 * component. If strictly routed make sure next 886 * address is on directly accessible net. 887 */ 888 case IPOPT_LSRR: 889 case IPOPT_SSRR: 890 if (ip_allowsrcrt == 0) { 891 type = ICMP_UNREACH; 892 code = ICMP_UNREACH_NET_PROHIB; 893 goto bad; 894 } 895 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 896 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 897 goto bad; 898 } 899 ipaddr.sin_addr = ip->ip_dst; 900 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 901 if (ia == 0) { 902 if (opt == IPOPT_SSRR) { 903 type = ICMP_UNREACH; 904 code = ICMP_UNREACH_SRCFAIL; 905 goto bad; 906 } 907 /* 908 * Loose routing, and not at next destination 909 * yet; nothing to do except forward. 910 */ 911 break; 912 } 913 off--; /* 0 origin */ 914 if (off > optlen - sizeof(struct in_addr)) { 915 /* 916 * End of source route. Should be for us. 917 */ 918 save_rte(cp, ip->ip_src); 919 break; 920 } 921 /* 922 * locate outgoing interface 923 */ 924 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 925 sizeof(ipaddr.sin_addr)); 926 if (opt == IPOPT_SSRR) { 927 #define INA struct in_ifaddr * 928 #define SA struct sockaddr * 929 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 930 } else 931 ia = ip_rtaddr(ipaddr.sin_addr); 932 if (ia == 0) { 933 type = ICMP_UNREACH; 934 code = ICMP_UNREACH_SRCFAIL; 935 goto bad; 936 } 937 ip->ip_dst = ipaddr.sin_addr; 938 bcopy((caddr_t)&ia->ia_addr.sin_addr, 939 (caddr_t)(cp + off), sizeof(struct in_addr)); 940 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 941 /* 942 * Let ip_intr's mcast routing check handle mcast pkts 943 */ 944 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 945 break; 946 947 case IPOPT_RR: 948 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 949 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 950 goto bad; 951 } 952 /* 953 * If no space remains, ignore. 954 */ 955 off--; /* 0 origin */ 956 if (off > optlen - sizeof(struct in_addr)) 957 break; 958 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 959 sizeof(ipaddr.sin_addr)); 960 /* 961 * locate outgoing interface; if we're the destination, 962 * use the incoming interface (should be same). 963 */ 964 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 965 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 966 type = ICMP_UNREACH; 967 code = ICMP_UNREACH_HOST; 968 goto bad; 969 } 970 bcopy((caddr_t)&ia->ia_addr.sin_addr, 971 (caddr_t)(cp + off), sizeof(struct in_addr)); 972 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 973 break; 974 975 case IPOPT_TS: 976 code = cp - (u_char *)ip; 977 ipt = (struct ip_timestamp *)cp; 978 if (ipt->ipt_len < 5) 979 goto bad; 980 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 981 if (++ipt->ipt_oflw == 0) 982 goto bad; 983 break; 984 } 985 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 986 switch (ipt->ipt_flg) { 987 988 case IPOPT_TS_TSONLY: 989 break; 990 991 case IPOPT_TS_TSANDADDR: 992 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 993 sizeof(struct in_addr) > ipt->ipt_len) 994 goto bad; 995 ipaddr.sin_addr = dst; 996 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 997 m->m_pkthdr.rcvif); 998 if (ia == 0) 999 continue; 1000 bcopy((caddr_t)&ia->ia_addr.sin_addr, 1001 (caddr_t)sin, sizeof(struct in_addr)); 1002 ipt->ipt_ptr += sizeof(struct in_addr); 1003 break; 1004 1005 case IPOPT_TS_PRESPEC: 1006 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1007 sizeof(struct in_addr) > ipt->ipt_len) 1008 goto bad; 1009 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 1010 sizeof(struct in_addr)); 1011 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1012 continue; 1013 ipt->ipt_ptr += sizeof(struct in_addr); 1014 break; 1015 1016 default: 1017 goto bad; 1018 } 1019 ntime = iptime(); 1020 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1021 sizeof(n_time)); 1022 ipt->ipt_ptr += sizeof(n_time); 1023 } 1024 } 1025 if (forward) { 1026 if (ip_forwsrcrt == 0) { 1027 type = ICMP_UNREACH; 1028 code = ICMP_UNREACH_SRCFAIL; 1029 goto bad; 1030 } 1031 ip_forward(m, 1); 1032 return (1); 1033 } 1034 return (0); 1035 bad: 1036 icmp_error(m, type, code, 0, 0); 1037 ipstat.ips_badoptions++; 1038 return (1); 1039 } 1040 1041 /* 1042 * Given address of next destination (final or next hop), 1043 * return internet address info of interface to be used to get there. 1044 */ 1045 struct in_ifaddr * 1046 ip_rtaddr(dst) 1047 struct in_addr dst; 1048 { 1049 register struct sockaddr_in *sin; 1050 1051 sin = satosin(&ipforward_rt.ro_dst); 1052 1053 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1054 if (ipforward_rt.ro_rt) { 1055 RTFREE(ipforward_rt.ro_rt); 1056 ipforward_rt.ro_rt = 0; 1057 } 1058 sin->sin_family = AF_INET; 1059 sin->sin_len = sizeof(*sin); 1060 sin->sin_addr = dst; 1061 1062 rtalloc(&ipforward_rt); 1063 } 1064 if (ipforward_rt.ro_rt == 0) 1065 return ((struct in_ifaddr *)0); 1066 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1067 } 1068 1069 /* 1070 * Save incoming source route for use in replies, 1071 * to be picked up later by ip_srcroute if the receiver is interested. 1072 */ 1073 void 1074 save_rte(option, dst) 1075 u_char *option; 1076 struct in_addr dst; 1077 { 1078 unsigned olen; 1079 1080 olen = option[IPOPT_OLEN]; 1081 #ifdef DIAGNOSTIC 1082 if (ipprintfs) 1083 printf("save_rte: olen %d\n", olen); 1084 #endif 1085 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1086 return; 1087 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1088 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1089 ip_srcrt.dst = dst; 1090 } 1091 1092 /* 1093 * Retrieve incoming source route for use in replies, 1094 * in the same form used by setsockopt. 1095 * The first hop is placed before the options, will be removed later. 1096 */ 1097 struct mbuf * 1098 ip_srcroute() 1099 { 1100 register struct in_addr *p, *q; 1101 register struct mbuf *m; 1102 1103 if (ip_nhops == 0) 1104 return ((struct mbuf *)0); 1105 m = m_get(M_DONTWAIT, MT_SOOPTS); 1106 if (m == 0) 1107 return ((struct mbuf *)0); 1108 1109 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1110 1111 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1112 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1113 OPTSIZ; 1114 #ifdef DIAGNOSTIC 1115 if (ipprintfs) 1116 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1117 #endif 1118 1119 /* 1120 * First save first hop for return route 1121 */ 1122 p = &ip_srcrt.route[ip_nhops - 1]; 1123 *(mtod(m, struct in_addr *)) = *p--; 1124 #ifdef DIAGNOSTIC 1125 if (ipprintfs) 1126 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1127 #endif 1128 1129 /* 1130 * Copy option fields and padding (nop) to mbuf. 1131 */ 1132 ip_srcrt.nop = IPOPT_NOP; 1133 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1134 bcopy((caddr_t)&ip_srcrt.nop, 1135 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1136 q = (struct in_addr *)(mtod(m, caddr_t) + 1137 sizeof(struct in_addr) + OPTSIZ); 1138 #undef OPTSIZ 1139 /* 1140 * Record return path as an IP source route, 1141 * reversing the path (pointers are now aligned). 1142 */ 1143 while (p >= ip_srcrt.route) { 1144 #ifdef DIAGNOSTIC 1145 if (ipprintfs) 1146 printf(" %x", ntohl(q->s_addr)); 1147 #endif 1148 *q++ = *p--; 1149 } 1150 /* 1151 * Last hop goes to final destination. 1152 */ 1153 *q = ip_srcrt.dst; 1154 #ifdef DIAGNOSTIC 1155 if (ipprintfs) 1156 printf(" %x\n", ntohl(q->s_addr)); 1157 #endif 1158 return (m); 1159 } 1160 1161 /* 1162 * Strip out IP options, at higher 1163 * level protocol in the kernel. 1164 * Second argument is buffer to which options 1165 * will be moved, and return value is their length. 1166 * XXX should be deleted; last arg currently ignored. 1167 */ 1168 void 1169 ip_stripoptions(m, mopt) 1170 register struct mbuf *m; 1171 struct mbuf *mopt; 1172 { 1173 register int i; 1174 struct ip *ip = mtod(m, struct ip *); 1175 register caddr_t opts; 1176 int olen; 1177 1178 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1179 opts = (caddr_t)(ip + 1); 1180 i = m->m_len - (sizeof (struct ip) + olen); 1181 bcopy(opts + olen, opts, (unsigned)i); 1182 m->m_len -= olen; 1183 if (m->m_flags & M_PKTHDR) 1184 m->m_pkthdr.len -= olen; 1185 ip->ip_len -= olen; 1186 ip->ip_hl = sizeof (struct ip) >> 2; 1187 } 1188 1189 int inetctlerrmap[PRC_NCMDS] = { 1190 0, 0, 0, 0, 1191 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1192 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1193 EMSGSIZE, EHOSTUNREACH, 0, 0, 1194 0, 0, 0, 0, 1195 ENOPROTOOPT 1196 }; 1197 1198 /* 1199 * Forward a packet. If some error occurs return the sender 1200 * an icmp packet. Note we can't always generate a meaningful 1201 * icmp message because icmp doesn't have a large enough repertoire 1202 * of codes and types. 1203 * 1204 * If not forwarding, just drop the packet. This could be confusing 1205 * if ipforwarding was zero but some routing protocol was advancing 1206 * us as a gateway to somewhere. However, we must let the routing 1207 * protocol deal with that. 1208 * 1209 * The srcrt parameter indicates whether the packet is being forwarded 1210 * via a source route. 1211 */ 1212 void 1213 ip_forward(m, srcrt) 1214 struct mbuf *m; 1215 int srcrt; 1216 { 1217 register struct ip *ip = mtod(m, struct ip *); 1218 register struct sockaddr_in *sin; 1219 register struct rtentry *rt; 1220 int error, type = 0, code = 0; 1221 struct mbuf *mcopy; 1222 n_long dest; 1223 struct ifnet *destifp; 1224 1225 dest = 0; 1226 #ifdef DIAGNOSTIC 1227 if (ipprintfs) 1228 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1229 ntohl(ip->ip_src.s_addr), 1230 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1231 #endif 1232 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1233 ipstat.ips_cantforward++; 1234 m_freem(m); 1235 return; 1236 } 1237 if (ip->ip_ttl <= IPTTLDEC) { 1238 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1239 return; 1240 } 1241 ip->ip_ttl -= IPTTLDEC; 1242 1243 sin = satosin(&ipforward_rt.ro_dst); 1244 if ((rt = ipforward_rt.ro_rt) == 0 || 1245 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1246 if (ipforward_rt.ro_rt) { 1247 RTFREE(ipforward_rt.ro_rt); 1248 ipforward_rt.ro_rt = 0; 1249 } 1250 sin->sin_family = AF_INET; 1251 sin->sin_len = sizeof(struct sockaddr_in); 1252 sin->sin_addr = ip->ip_dst; 1253 1254 rtalloc(&ipforward_rt); 1255 if (ipforward_rt.ro_rt == 0) { 1256 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1257 return; 1258 } 1259 rt = ipforward_rt.ro_rt; 1260 } 1261 1262 /* 1263 * Save at most 68 bytes of the packet in case 1264 * we need to generate an ICMP message to the src. 1265 */ 1266 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1267 1268 /* 1269 * If forwarding packet using same interface that it came in on, 1270 * perhaps should send a redirect to sender to shortcut a hop. 1271 * Only send redirect if source is sending directly to us, 1272 * and if packet was not source routed (or has any options). 1273 * Also, don't send redirect if forwarding using a default route 1274 * or a route modified by a redirect. 1275 */ 1276 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1277 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1278 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1279 ipsendredirects && !srcrt) { 1280 if (rt->rt_ifa && 1281 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1282 ifatoia(rt->rt_ifa)->ia_subnet) { 1283 if (rt->rt_flags & RTF_GATEWAY) 1284 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1285 else 1286 dest = ip->ip_dst.s_addr; 1287 /* 1288 * Router requirements says to only send host 1289 * redirects. 1290 */ 1291 type = ICMP_REDIRECT; 1292 code = ICMP_REDIRECT_HOST; 1293 #ifdef DIAGNOSTIC 1294 if (ipprintfs) 1295 printf("redirect (%d) to %x\n", code, 1296 (u_int32_t)dest); 1297 #endif 1298 } 1299 } 1300 1301 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1302 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1303 if (error) 1304 ipstat.ips_cantforward++; 1305 else { 1306 ipstat.ips_forward++; 1307 if (type) 1308 ipstat.ips_redirectsent++; 1309 else { 1310 if (mcopy) { 1311 #ifdef GATEWAY 1312 if (mcopy->m_flags & M_CANFASTFWD) 1313 ipflow_create(&ipforward_rt, mcopy); 1314 #endif 1315 m_freem(mcopy); 1316 } 1317 return; 1318 } 1319 } 1320 if (mcopy == NULL) 1321 return; 1322 destifp = NULL; 1323 1324 switch (error) { 1325 1326 case 0: /* forwarded, but need redirect */ 1327 /* type, code set above */ 1328 break; 1329 1330 case ENETUNREACH: /* shouldn't happen, checked above */ 1331 case EHOSTUNREACH: 1332 case ENETDOWN: 1333 case EHOSTDOWN: 1334 default: 1335 type = ICMP_UNREACH; 1336 code = ICMP_UNREACH_HOST; 1337 break; 1338 1339 case EMSGSIZE: 1340 type = ICMP_UNREACH; 1341 code = ICMP_UNREACH_NEEDFRAG; 1342 if (ipforward_rt.ro_rt) 1343 destifp = ipforward_rt.ro_rt->rt_ifp; 1344 ipstat.ips_cantfrag++; 1345 break; 1346 1347 case ENOBUFS: 1348 type = ICMP_SOURCEQUENCH; 1349 code = 0; 1350 break; 1351 } 1352 icmp_error(mcopy, type, code, dest, destifp); 1353 } 1354 1355 void 1356 ip_savecontrol(inp, mp, ip, m) 1357 register struct inpcb *inp; 1358 register struct mbuf **mp; 1359 register struct ip *ip; 1360 register struct mbuf *m; 1361 { 1362 1363 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1364 struct timeval tv; 1365 1366 microtime(&tv); 1367 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1368 SCM_TIMESTAMP, SOL_SOCKET); 1369 if (*mp) 1370 mp = &(*mp)->m_next; 1371 } 1372 if (inp->inp_flags & INP_RECVDSTADDR) { 1373 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1374 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1375 if (*mp) 1376 mp = &(*mp)->m_next; 1377 } 1378 #ifdef notyet 1379 /* 1380 * XXX 1381 * Moving these out of udp_input() made them even more broken 1382 * than they already were. 1383 * - fenner (at) parc.xerox.com 1384 */ 1385 /* options were tossed already */ 1386 if (inp->inp_flags & INP_RECVOPTS) { 1387 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1388 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1389 if (*mp) 1390 mp = &(*mp)->m_next; 1391 } 1392 /* ip_srcroute doesn't do what we want here, need to fix */ 1393 if (inp->inp_flags & INP_RECVRETOPTS) { 1394 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1395 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1396 if (*mp) 1397 mp = &(*mp)->m_next; 1398 } 1399 #endif 1400 if (inp->inp_flags & INP_RECVIF) { 1401 struct sockaddr_dl sdl; 1402 1403 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1404 sdl.sdl_family = AF_LINK; 1405 sdl.sdl_index = m->m_pkthdr.rcvif ? 1406 m->m_pkthdr.rcvif->if_index : 0; 1407 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1408 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1409 IP_RECVIF, IPPROTO_IP); 1410 if (*mp) 1411 mp = &(*mp)->m_next; 1412 } 1413 } 1414 1415 int 1416 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1417 int *name; 1418 u_int namelen; 1419 void *oldp; 1420 size_t *oldlenp; 1421 void *newp; 1422 size_t newlen; 1423 { 1424 extern int subnetsarelocal; 1425 1426 int error, old; 1427 1428 /* All sysctl names at this level are terminal. */ 1429 if (namelen != 1) 1430 return (ENOTDIR); 1431 1432 switch (name[0]) { 1433 case IPCTL_FORWARDING: 1434 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1435 case IPCTL_SENDREDIRECTS: 1436 return (sysctl_int(oldp, oldlenp, newp, newlen, 1437 &ipsendredirects)); 1438 case IPCTL_DEFTTL: 1439 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1440 #ifdef notyet 1441 case IPCTL_DEFMTU: 1442 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1443 #endif 1444 case IPCTL_FORWSRCRT: 1445 /* Don't allow this to change in a secure environment. */ 1446 if (securelevel > 0) 1447 return (sysctl_rdint(oldp, oldlenp, newp, 1448 ip_forwsrcrt)); 1449 else 1450 return (sysctl_int(oldp, oldlenp, newp, newlen, 1451 &ip_forwsrcrt)); 1452 case IPCTL_DIRECTEDBCAST: 1453 return (sysctl_int(oldp, oldlenp, newp, newlen, 1454 &ip_directedbcast)); 1455 case IPCTL_ALLOWSRCRT: 1456 return (sysctl_int(oldp, oldlenp, newp, newlen, 1457 &ip_allowsrcrt)); 1458 case IPCTL_SUBNETSARELOCAL: 1459 return (sysctl_int(oldp, oldlenp, newp, newlen, 1460 &subnetsarelocal)); 1461 case IPCTL_MTUDISC: 1462 error = sysctl_int(oldp, oldlenp, newp, newlen, 1463 &ip_mtudisc); 1464 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1465 ip_mtudisc_timeout_q = 1466 rt_timer_queue_create(ip_mtudisc_timeout); 1467 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1468 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1469 ip_mtudisc_timeout_q = NULL; 1470 } 1471 return error; 1472 case IPCTL_ANONPORTMIN: 1473 old = anonportmin; 1474 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1475 if (anonportmin >= anonportmax || anonportmin > 65535 1476 #ifndef IPNOPRIVPORTS 1477 || anonportmin < IPPORT_RESERVED 1478 #endif 1479 ) { 1480 anonportmin = old; 1481 return (EINVAL); 1482 } 1483 return (error); 1484 case IPCTL_ANONPORTMAX: 1485 old = anonportmax; 1486 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1487 if (anonportmin >= anonportmax || anonportmax > 65535 1488 #ifndef IPNOPRIVPORTS 1489 || anonportmax < IPPORT_RESERVED 1490 #endif 1491 ) { 1492 anonportmax = old; 1493 return (EINVAL); 1494 } 1495 return (error); 1496 case IPCTL_MTUDISCTIMEOUT: 1497 error = sysctl_int(oldp, oldlenp, newp, newlen, 1498 &ip_mtudisc_timeout); 1499 if (ip_mtudisc_timeout_q != NULL) 1500 rt_timer_queue_change(ip_mtudisc_timeout_q, 1501 ip_mtudisc_timeout); 1502 return (error); 1503 #ifdef GATEWAY 1504 case IPCTL_MAXFLOWS: 1505 { 1506 int s; 1507 1508 error = sysctl_int(oldp, oldlenp, newp, newlen, 1509 &ip_maxflows); 1510 s = splsoftnet(); 1511 ipflow_reap(0); 1512 splx(s); 1513 return (error); 1514 } 1515 #endif 1516 default: 1517 return (EOPNOTSUPP); 1518 } 1519 /* NOTREACHED */ 1520 } 1521
Indexes created Wed Oct 22 06:10:02 GMT 2025