ip_input.c revision 1.82.2.2
1 /* $NetBSD: ip_input.c,v 1.82.2.2 1999/05/03 22:22:42 perry 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 goto ours; 425 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 426 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 427 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 428 if (ifa->ifa_addr->sa_family != AF_INET) continue; 429 ia = ifatoia(ifa); 430 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 431 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 432 /* 433 * Look for all-0's host part (old broadcast addr), 434 * either for subnet or net. 435 */ 436 ip->ip_dst.s_addr == ia->ia_subnet || 437 ip->ip_dst.s_addr == ia->ia_net) 438 goto ours; 439 /* 440 * An interface with IP address zero accepts 441 * all packets that arrive on that interface. 442 */ 443 if (in_nullhost(ia->ia_addr.sin_addr)) 444 goto ours; 445 } 446 } 447 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 448 struct in_multi *inm; 449 #ifdef MROUTING 450 extern struct socket *ip_mrouter; 451 452 if (m->m_flags & M_EXT) { 453 if ((m = m_pullup(m, hlen)) == 0) { 454 ipstat.ips_toosmall++; 455 goto next; 456 } 457 ip = mtod(m, struct ip *); 458 } 459 460 if (ip_mrouter) { 461 /* 462 * If we are acting as a multicast router, all 463 * incoming multicast packets are passed to the 464 * kernel-level multicast forwarding function. 465 * The packet is returned (relatively) intact; if 466 * ip_mforward() returns a non-zero value, the packet 467 * must be discarded, else it may be accepted below. 468 * 469 * (The IP ident field is put in the same byte order 470 * as expected when ip_mforward() is called from 471 * ip_output().) 472 */ 473 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 474 ipstat.ips_cantforward++; 475 m_freem(m); 476 goto next; 477 } 478 479 /* 480 * The process-level routing demon needs to receive 481 * all multicast IGMP packets, whether or not this 482 * host belongs to their destination groups. 483 */ 484 if (ip->ip_p == IPPROTO_IGMP) 485 goto ours; 486 ipstat.ips_forward++; 487 } 488 #endif 489 /* 490 * See if we belong to the destination multicast group on the 491 * arrival interface. 492 */ 493 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 494 if (inm == NULL) { 495 ipstat.ips_cantforward++; 496 m_freem(m); 497 goto next; 498 } 499 goto ours; 500 } 501 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 502 in_nullhost(ip->ip_dst)) 503 goto ours; 504 505 /* 506 * Not for us; forward if possible and desirable. 507 */ 508 if (ipforwarding == 0) { 509 ipstat.ips_cantforward++; 510 m_freem(m); 511 } else 512 ip_forward(m, 0); 513 goto next; 514 515 ours: 516 /* 517 * If offset or IP_MF are set, must reassemble. 518 * Otherwise, nothing need be done. 519 * (We could look in the reassembly queue to see 520 * if the packet was previously fragmented, 521 * but it's not worth the time; just let them time out.) 522 */ 523 if (ip->ip_off & ~(IP_DF|IP_RF)) { 524 /* 525 * Look for queue of fragments 526 * of this datagram. 527 */ 528 IPQ_LOCK(); 529 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 530 if (ip->ip_id == fp->ipq_id && 531 in_hosteq(ip->ip_src, fp->ipq_src) && 532 in_hosteq(ip->ip_dst, fp->ipq_dst) && 533 ip->ip_p == fp->ipq_p) 534 goto found; 535 fp = 0; 536 found: 537 538 /* 539 * Adjust ip_len to not reflect header, 540 * set ipqe_mff if more fragments are expected, 541 * convert offset of this to bytes. 542 */ 543 ip->ip_len -= hlen; 544 mff = (ip->ip_off & IP_MF) != 0; 545 if (mff) { 546 /* 547 * Make sure that fragments have a data length 548 * that's a non-zero multiple of 8 bytes. 549 */ 550 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 551 ipstat.ips_badfrags++; 552 IPQ_UNLOCK(); 553 goto bad; 554 } 555 } 556 ip->ip_off <<= 3; 557 558 /* 559 * If datagram marked as having more fragments 560 * or if this is not the first fragment, 561 * attempt reassembly; if it succeeds, proceed. 562 */ 563 if (mff || ip->ip_off) { 564 ipstat.ips_fragments++; 565 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 566 if (ipqe == NULL) { 567 ipstat.ips_rcvmemdrop++; 568 IPQ_UNLOCK(); 569 goto bad; 570 } 571 ipqe->ipqe_mff = mff; 572 ipqe->ipqe_m = m; 573 ipqe->ipqe_ip = ip; 574 m = ip_reass(ipqe, fp); 575 if (m == 0) { 576 IPQ_UNLOCK(); 577 goto next; 578 } 579 ipstat.ips_reassembled++; 580 ip = mtod(m, struct ip *); 581 hlen = ip->ip_hl << 2; 582 ip->ip_len += hlen; 583 } else 584 if (fp) 585 ip_freef(fp); 586 IPQ_UNLOCK(); 587 } 588 589 /* 590 * Switch out to protocol's input routine. 591 */ 592 #if IFA_STATS 593 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len; 594 #endif 595 ipstat.ips_delivered++; 596 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 597 goto next; 598 bad: 599 m_freem(m); 600 goto next; 601 } 602 603 /* 604 * Take incoming datagram fragment and try to 605 * reassemble it into whole datagram. If a chain for 606 * reassembly of this datagram already exists, then it 607 * is given as fp; otherwise have to make a chain. 608 */ 609 struct mbuf * 610 ip_reass(ipqe, fp) 611 register struct ipqent *ipqe; 612 register struct ipq *fp; 613 { 614 register struct mbuf *m = ipqe->ipqe_m; 615 register struct ipqent *nq, *p, *q; 616 struct ip *ip; 617 struct mbuf *t; 618 int hlen = ipqe->ipqe_ip->ip_hl << 2; 619 int i, next; 620 621 IPQ_LOCK_CHECK(); 622 623 /* 624 * Presence of header sizes in mbufs 625 * would confuse code below. 626 */ 627 m->m_data += hlen; 628 m->m_len -= hlen; 629 630 /* 631 * If first fragment to arrive, create a reassembly queue. 632 */ 633 if (fp == 0) { 634 MALLOC(fp, struct ipq *, sizeof (struct ipq), 635 M_FTABLE, M_NOWAIT); 636 if (fp == NULL) 637 goto dropfrag; 638 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 639 fp->ipq_ttl = IPFRAGTTL; 640 fp->ipq_p = ipqe->ipqe_ip->ip_p; 641 fp->ipq_id = ipqe->ipqe_ip->ip_id; 642 LIST_INIT(&fp->ipq_fragq); 643 fp->ipq_src = ipqe->ipqe_ip->ip_src; 644 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 645 p = NULL; 646 goto insert; 647 } 648 649 /* 650 * Find a segment which begins after this one does. 651 */ 652 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 653 p = q, q = q->ipqe_q.le_next) 654 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 655 break; 656 657 /* 658 * If there is a preceding segment, it may provide some of 659 * our data already. If so, drop the data from the incoming 660 * segment. If it provides all of our data, drop us. 661 */ 662 if (p != NULL) { 663 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 664 ipqe->ipqe_ip->ip_off; 665 if (i > 0) { 666 if (i >= ipqe->ipqe_ip->ip_len) 667 goto dropfrag; 668 m_adj(ipqe->ipqe_m, i); 669 ipqe->ipqe_ip->ip_off += i; 670 ipqe->ipqe_ip->ip_len -= i; 671 } 672 } 673 674 /* 675 * While we overlap succeeding segments trim them or, 676 * if they are completely covered, dequeue them. 677 */ 678 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 679 q->ipqe_ip->ip_off; q = nq) { 680 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 681 q->ipqe_ip->ip_off; 682 if (i < q->ipqe_ip->ip_len) { 683 q->ipqe_ip->ip_len -= i; 684 q->ipqe_ip->ip_off += i; 685 m_adj(q->ipqe_m, i); 686 break; 687 } 688 nq = q->ipqe_q.le_next; 689 m_freem(q->ipqe_m); 690 LIST_REMOVE(q, ipqe_q); 691 pool_put(&ipqent_pool, q); 692 } 693 694 insert: 695 /* 696 * Stick new segment in its place; 697 * check for complete reassembly. 698 */ 699 if (p == NULL) { 700 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 701 } else { 702 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 703 } 704 next = 0; 705 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 706 p = q, q = q->ipqe_q.le_next) { 707 if (q->ipqe_ip->ip_off != next) 708 return (0); 709 next += q->ipqe_ip->ip_len; 710 } 711 if (p->ipqe_mff) 712 return (0); 713 714 /* 715 * Reassembly is complete. Check for a bogus message size and 716 * concatenate fragments. 717 */ 718 q = fp->ipq_fragq.lh_first; 719 ip = q->ipqe_ip; 720 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 721 ipstat.ips_toolong++; 722 ip_freef(fp); 723 return (0); 724 } 725 m = q->ipqe_m; 726 t = m->m_next; 727 m->m_next = 0; 728 m_cat(m, t); 729 nq = q->ipqe_q.le_next; 730 pool_put(&ipqent_pool, q); 731 for (q = nq; q != NULL; q = nq) { 732 t = q->ipqe_m; 733 nq = q->ipqe_q.le_next; 734 pool_put(&ipqent_pool, q); 735 m_cat(m, t); 736 } 737 738 /* 739 * Create header for new ip packet by 740 * modifying header of first packet; 741 * dequeue and discard fragment reassembly header. 742 * Make header visible. 743 */ 744 ip->ip_len = next; 745 ip->ip_src = fp->ipq_src; 746 ip->ip_dst = fp->ipq_dst; 747 LIST_REMOVE(fp, ipq_q); 748 FREE(fp, M_FTABLE); 749 m->m_len += (ip->ip_hl << 2); 750 m->m_data -= (ip->ip_hl << 2); 751 /* some debugging cruft by sklower, below, will go away soon */ 752 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 753 register int plen = 0; 754 for (t = m; t; t = t->m_next) 755 plen += t->m_len; 756 m->m_pkthdr.len = plen; 757 } 758 return (m); 759 760 dropfrag: 761 ipstat.ips_fragdropped++; 762 m_freem(m); 763 pool_put(&ipqent_pool, ipqe); 764 return (0); 765 } 766 767 /* 768 * Free a fragment reassembly header and all 769 * associated datagrams. 770 */ 771 void 772 ip_freef(fp) 773 struct ipq *fp; 774 { 775 register struct ipqent *q, *p; 776 777 IPQ_LOCK_CHECK(); 778 779 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 780 p = q->ipqe_q.le_next; 781 m_freem(q->ipqe_m); 782 LIST_REMOVE(q, ipqe_q); 783 pool_put(&ipqent_pool, q); 784 } 785 LIST_REMOVE(fp, ipq_q); 786 FREE(fp, M_FTABLE); 787 } 788 789 /* 790 * IP timer processing; 791 * if a timer expires on a reassembly 792 * queue, discard it. 793 */ 794 void 795 ip_slowtimo() 796 { 797 register struct ipq *fp, *nfp; 798 int s = splsoftnet(); 799 800 IPQ_LOCK(); 801 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 802 nfp = fp->ipq_q.le_next; 803 if (--fp->ipq_ttl == 0) { 804 ipstat.ips_fragtimeout++; 805 ip_freef(fp); 806 } 807 } 808 IPQ_UNLOCK(); 809 #ifdef GATEWAY 810 ipflow_slowtimo(); 811 #endif 812 splx(s); 813 } 814 815 /* 816 * Drain off all datagram fragments. 817 */ 818 void 819 ip_drain() 820 { 821 822 /* 823 * We may be called from a device's interrupt context. If 824 * the ipq is already busy, just bail out now. 825 */ 826 if (ipq_lock_try() == 0) 827 return; 828 829 while (ipq.lh_first != NULL) { 830 ipstat.ips_fragdropped++; 831 ip_freef(ipq.lh_first); 832 } 833 834 IPQ_UNLOCK(); 835 } 836 837 /* 838 * Do option processing on a datagram, 839 * possibly discarding it if bad options are encountered, 840 * or forwarding it if source-routed. 841 * Returns 1 if packet has been forwarded/freed, 842 * 0 if the packet should be processed further. 843 */ 844 int 845 ip_dooptions(m) 846 struct mbuf *m; 847 { 848 register struct ip *ip = mtod(m, struct ip *); 849 register u_char *cp; 850 register struct ip_timestamp *ipt; 851 register struct in_ifaddr *ia; 852 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 853 struct in_addr *sin, dst; 854 n_time ntime; 855 856 dst = ip->ip_dst; 857 cp = (u_char *)(ip + 1); 858 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 859 for (; cnt > 0; cnt -= optlen, cp += optlen) { 860 opt = cp[IPOPT_OPTVAL]; 861 if (opt == IPOPT_EOL) 862 break; 863 if (opt == IPOPT_NOP) 864 optlen = 1; 865 else { 866 optlen = cp[IPOPT_OLEN]; 867 if (optlen <= 0 || optlen > cnt) { 868 code = &cp[IPOPT_OLEN] - (u_char *)ip; 869 goto bad; 870 } 871 } 872 switch (opt) { 873 874 default: 875 break; 876 877 /* 878 * Source routing with record. 879 * Find interface with current destination address. 880 * If none on this machine then drop if strictly routed, 881 * or do nothing if loosely routed. 882 * Record interface address and bring up next address 883 * component. If strictly routed make sure next 884 * address is on directly accessible net. 885 */ 886 case IPOPT_LSRR: 887 case IPOPT_SSRR: 888 if (ip_allowsrcrt == 0) { 889 type = ICMP_UNREACH; 890 code = ICMP_UNREACH_NET_PROHIB; 891 goto bad; 892 } 893 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 894 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 895 goto bad; 896 } 897 ipaddr.sin_addr = ip->ip_dst; 898 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 899 if (ia == 0) { 900 if (opt == IPOPT_SSRR) { 901 type = ICMP_UNREACH; 902 code = ICMP_UNREACH_SRCFAIL; 903 goto bad; 904 } 905 /* 906 * Loose routing, and not at next destination 907 * yet; nothing to do except forward. 908 */ 909 break; 910 } 911 off--; /* 0 origin */ 912 if (off > optlen - sizeof(struct in_addr)) { 913 /* 914 * End of source route. Should be for us. 915 */ 916 save_rte(cp, ip->ip_src); 917 break; 918 } 919 /* 920 * locate outgoing interface 921 */ 922 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 923 sizeof(ipaddr.sin_addr)); 924 if (opt == IPOPT_SSRR) { 925 #define INA struct in_ifaddr * 926 #define SA struct sockaddr * 927 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 928 } else 929 ia = ip_rtaddr(ipaddr.sin_addr); 930 if (ia == 0) { 931 type = ICMP_UNREACH; 932 code = ICMP_UNREACH_SRCFAIL; 933 goto bad; 934 } 935 ip->ip_dst = ipaddr.sin_addr; 936 bcopy((caddr_t)&ia->ia_addr.sin_addr, 937 (caddr_t)(cp + off), sizeof(struct in_addr)); 938 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 939 /* 940 * Let ip_intr's mcast routing check handle mcast pkts 941 */ 942 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 943 break; 944 945 case IPOPT_RR: 946 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 947 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 948 goto bad; 949 } 950 /* 951 * If no space remains, ignore. 952 */ 953 off--; /* 0 origin */ 954 if (off > optlen - sizeof(struct in_addr)) 955 break; 956 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 957 sizeof(ipaddr.sin_addr)); 958 /* 959 * locate outgoing interface; if we're the destination, 960 * use the incoming interface (should be same). 961 */ 962 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 963 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 964 type = ICMP_UNREACH; 965 code = ICMP_UNREACH_HOST; 966 goto bad; 967 } 968 bcopy((caddr_t)&ia->ia_addr.sin_addr, 969 (caddr_t)(cp + off), sizeof(struct in_addr)); 970 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 971 break; 972 973 case IPOPT_TS: 974 code = cp - (u_char *)ip; 975 ipt = (struct ip_timestamp *)cp; 976 if (ipt->ipt_len < 5) 977 goto bad; 978 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 979 if (++ipt->ipt_oflw == 0) 980 goto bad; 981 break; 982 } 983 sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); 984 switch (ipt->ipt_flg) { 985 986 case IPOPT_TS_TSONLY: 987 break; 988 989 case IPOPT_TS_TSANDADDR: 990 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 991 sizeof(struct in_addr) > ipt->ipt_len) 992 goto bad; 993 ipaddr.sin_addr = dst; 994 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 995 m->m_pkthdr.rcvif); 996 if (ia == 0) 997 continue; 998 bcopy((caddr_t)&ia->ia_addr.sin_addr, 999 (caddr_t)sin, sizeof(struct in_addr)); 1000 ipt->ipt_ptr += sizeof(struct in_addr); 1001 break; 1002 1003 case IPOPT_TS_PRESPEC: 1004 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1005 sizeof(struct in_addr) > ipt->ipt_len) 1006 goto bad; 1007 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, 1008 sizeof(struct in_addr)); 1009 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1010 continue; 1011 ipt->ipt_ptr += sizeof(struct in_addr); 1012 break; 1013 1014 default: 1015 goto bad; 1016 } 1017 ntime = iptime(); 1018 bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, 1019 sizeof(n_time)); 1020 ipt->ipt_ptr += sizeof(n_time); 1021 } 1022 } 1023 if (forward) { 1024 if (ip_forwsrcrt == 0) { 1025 type = ICMP_UNREACH; 1026 code = ICMP_UNREACH_SRCFAIL; 1027 goto bad; 1028 } 1029 ip_forward(m, 1); 1030 return (1); 1031 } 1032 return (0); 1033 bad: 1034 icmp_error(m, type, code, 0, 0); 1035 ipstat.ips_badoptions++; 1036 return (1); 1037 } 1038 1039 /* 1040 * Given address of next destination (final or next hop), 1041 * return internet address info of interface to be used to get there. 1042 */ 1043 struct in_ifaddr * 1044 ip_rtaddr(dst) 1045 struct in_addr dst; 1046 { 1047 register struct sockaddr_in *sin; 1048 1049 sin = satosin(&ipforward_rt.ro_dst); 1050 1051 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1052 if (ipforward_rt.ro_rt) { 1053 RTFREE(ipforward_rt.ro_rt); 1054 ipforward_rt.ro_rt = 0; 1055 } 1056 sin->sin_family = AF_INET; 1057 sin->sin_len = sizeof(*sin); 1058 sin->sin_addr = dst; 1059 1060 rtalloc(&ipforward_rt); 1061 } 1062 if (ipforward_rt.ro_rt == 0) 1063 return ((struct in_ifaddr *)0); 1064 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1065 } 1066 1067 /* 1068 * Save incoming source route for use in replies, 1069 * to be picked up later by ip_srcroute if the receiver is interested. 1070 */ 1071 void 1072 save_rte(option, dst) 1073 u_char *option; 1074 struct in_addr dst; 1075 { 1076 unsigned olen; 1077 1078 olen = option[IPOPT_OLEN]; 1079 #ifdef DIAGNOSTIC 1080 if (ipprintfs) 1081 printf("save_rte: olen %d\n", olen); 1082 #endif 1083 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1084 return; 1085 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1086 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1087 ip_srcrt.dst = dst; 1088 } 1089 1090 /* 1091 * Retrieve incoming source route for use in replies, 1092 * in the same form used by setsockopt. 1093 * The first hop is placed before the options, will be removed later. 1094 */ 1095 struct mbuf * 1096 ip_srcroute() 1097 { 1098 register struct in_addr *p, *q; 1099 register struct mbuf *m; 1100 1101 if (ip_nhops == 0) 1102 return ((struct mbuf *)0); 1103 m = m_get(M_DONTWAIT, MT_SOOPTS); 1104 if (m == 0) 1105 return ((struct mbuf *)0); 1106 1107 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1108 1109 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1110 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1111 OPTSIZ; 1112 #ifdef DIAGNOSTIC 1113 if (ipprintfs) 1114 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1115 #endif 1116 1117 /* 1118 * First save first hop for return route 1119 */ 1120 p = &ip_srcrt.route[ip_nhops - 1]; 1121 *(mtod(m, struct in_addr *)) = *p--; 1122 #ifdef DIAGNOSTIC 1123 if (ipprintfs) 1124 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1125 #endif 1126 1127 /* 1128 * Copy option fields and padding (nop) to mbuf. 1129 */ 1130 ip_srcrt.nop = IPOPT_NOP; 1131 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1132 bcopy((caddr_t)&ip_srcrt.nop, 1133 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1134 q = (struct in_addr *)(mtod(m, caddr_t) + 1135 sizeof(struct in_addr) + OPTSIZ); 1136 #undef OPTSIZ 1137 /* 1138 * Record return path as an IP source route, 1139 * reversing the path (pointers are now aligned). 1140 */ 1141 while (p >= ip_srcrt.route) { 1142 #ifdef DIAGNOSTIC 1143 if (ipprintfs) 1144 printf(" %x", ntohl(q->s_addr)); 1145 #endif 1146 *q++ = *p--; 1147 } 1148 /* 1149 * Last hop goes to final destination. 1150 */ 1151 *q = ip_srcrt.dst; 1152 #ifdef DIAGNOSTIC 1153 if (ipprintfs) 1154 printf(" %x\n", ntohl(q->s_addr)); 1155 #endif 1156 return (m); 1157 } 1158 1159 /* 1160 * Strip out IP options, at higher 1161 * level protocol in the kernel. 1162 * Second argument is buffer to which options 1163 * will be moved, and return value is their length. 1164 * XXX should be deleted; last arg currently ignored. 1165 */ 1166 void 1167 ip_stripoptions(m, mopt) 1168 register struct mbuf *m; 1169 struct mbuf *mopt; 1170 { 1171 register int i; 1172 struct ip *ip = mtod(m, struct ip *); 1173 register caddr_t opts; 1174 int olen; 1175 1176 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1177 opts = (caddr_t)(ip + 1); 1178 i = m->m_len - (sizeof (struct ip) + olen); 1179 bcopy(opts + olen, opts, (unsigned)i); 1180 m->m_len -= olen; 1181 if (m->m_flags & M_PKTHDR) 1182 m->m_pkthdr.len -= olen; 1183 ip->ip_len -= olen; 1184 ip->ip_hl = sizeof (struct ip) >> 2; 1185 } 1186 1187 int inetctlerrmap[PRC_NCMDS] = { 1188 0, 0, 0, 0, 1189 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1190 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1191 EMSGSIZE, EHOSTUNREACH, 0, 0, 1192 0, 0, 0, 0, 1193 ENOPROTOOPT 1194 }; 1195 1196 /* 1197 * Forward a packet. If some error occurs return the sender 1198 * an icmp packet. Note we can't always generate a meaningful 1199 * icmp message because icmp doesn't have a large enough repertoire 1200 * of codes and types. 1201 * 1202 * If not forwarding, just drop the packet. This could be confusing 1203 * if ipforwarding was zero but some routing protocol was advancing 1204 * us as a gateway to somewhere. However, we must let the routing 1205 * protocol deal with that. 1206 * 1207 * The srcrt parameter indicates whether the packet is being forwarded 1208 * via a source route. 1209 */ 1210 void 1211 ip_forward(m, srcrt) 1212 struct mbuf *m; 1213 int srcrt; 1214 { 1215 register struct ip *ip = mtod(m, struct ip *); 1216 register struct sockaddr_in *sin; 1217 register struct rtentry *rt; 1218 int error, type = 0, code = 0; 1219 struct mbuf *mcopy; 1220 n_long dest; 1221 struct ifnet *destifp; 1222 1223 dest = 0; 1224 #ifdef DIAGNOSTIC 1225 if (ipprintfs) 1226 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1227 ntohl(ip->ip_src.s_addr), 1228 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1229 #endif 1230 if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { 1231 ipstat.ips_cantforward++; 1232 m_freem(m); 1233 return; 1234 } 1235 if (ip->ip_ttl <= IPTTLDEC) { 1236 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1237 return; 1238 } 1239 ip->ip_ttl -= IPTTLDEC; 1240 1241 sin = satosin(&ipforward_rt.ro_dst); 1242 if ((rt = ipforward_rt.ro_rt) == 0 || 1243 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1244 if (ipforward_rt.ro_rt) { 1245 RTFREE(ipforward_rt.ro_rt); 1246 ipforward_rt.ro_rt = 0; 1247 } 1248 sin->sin_family = AF_INET; 1249 sin->sin_len = sizeof(struct sockaddr_in); 1250 sin->sin_addr = ip->ip_dst; 1251 1252 rtalloc(&ipforward_rt); 1253 if (ipforward_rt.ro_rt == 0) { 1254 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1255 return; 1256 } 1257 rt = ipforward_rt.ro_rt; 1258 } 1259 1260 /* 1261 * Save at most 68 bytes of the packet in case 1262 * we need to generate an ICMP message to the src. 1263 */ 1264 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1265 1266 /* 1267 * If forwarding packet using same interface that it came in on, 1268 * perhaps should send a redirect to sender to shortcut a hop. 1269 * Only send redirect if source is sending directly to us, 1270 * and if packet was not source routed (or has any options). 1271 * Also, don't send redirect if forwarding using a default route 1272 * or a route modified by a redirect. 1273 */ 1274 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1275 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1276 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1277 ipsendredirects && !srcrt) { 1278 if (rt->rt_ifa && 1279 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1280 ifatoia(rt->rt_ifa)->ia_subnet) { 1281 if (rt->rt_flags & RTF_GATEWAY) 1282 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1283 else 1284 dest = ip->ip_dst.s_addr; 1285 /* 1286 * Router requirements says to only send host 1287 * redirects. 1288 */ 1289 type = ICMP_REDIRECT; 1290 code = ICMP_REDIRECT_HOST; 1291 #ifdef DIAGNOSTIC 1292 if (ipprintfs) 1293 printf("redirect (%d) to %x\n", code, 1294 (u_int32_t)dest); 1295 #endif 1296 } 1297 } 1298 1299 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1300 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1301 if (error) 1302 ipstat.ips_cantforward++; 1303 else { 1304 ipstat.ips_forward++; 1305 if (type) 1306 ipstat.ips_redirectsent++; 1307 else { 1308 if (mcopy) { 1309 #ifdef GATEWAY 1310 if (mcopy->m_flags & M_CANFASTFWD) 1311 ipflow_create(&ipforward_rt, mcopy); 1312 #endif 1313 m_freem(mcopy); 1314 } 1315 return; 1316 } 1317 } 1318 if (mcopy == NULL) 1319 return; 1320 destifp = NULL; 1321 1322 switch (error) { 1323 1324 case 0: /* forwarded, but need redirect */ 1325 /* type, code set above */ 1326 break; 1327 1328 case ENETUNREACH: /* shouldn't happen, checked above */ 1329 case EHOSTUNREACH: 1330 case ENETDOWN: 1331 case EHOSTDOWN: 1332 default: 1333 type = ICMP_UNREACH; 1334 code = ICMP_UNREACH_HOST; 1335 break; 1336 1337 case EMSGSIZE: 1338 type = ICMP_UNREACH; 1339 code = ICMP_UNREACH_NEEDFRAG; 1340 if (ipforward_rt.ro_rt) 1341 destifp = ipforward_rt.ro_rt->rt_ifp; 1342 ipstat.ips_cantfrag++; 1343 break; 1344 1345 case ENOBUFS: 1346 type = ICMP_SOURCEQUENCH; 1347 code = 0; 1348 break; 1349 } 1350 icmp_error(mcopy, type, code, dest, destifp); 1351 } 1352 1353 void 1354 ip_savecontrol(inp, mp, ip, m) 1355 register struct inpcb *inp; 1356 register struct mbuf **mp; 1357 register struct ip *ip; 1358 register struct mbuf *m; 1359 { 1360 1361 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1362 struct timeval tv; 1363 1364 microtime(&tv); 1365 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1366 SCM_TIMESTAMP, SOL_SOCKET); 1367 if (*mp) 1368 mp = &(*mp)->m_next; 1369 } 1370 if (inp->inp_flags & INP_RECVDSTADDR) { 1371 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1372 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1373 if (*mp) 1374 mp = &(*mp)->m_next; 1375 } 1376 #ifdef notyet 1377 /* 1378 * XXX 1379 * Moving these out of udp_input() made them even more broken 1380 * than they already were. 1381 * - fenner (at) parc.xerox.com 1382 */ 1383 /* options were tossed already */ 1384 if (inp->inp_flags & INP_RECVOPTS) { 1385 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1386 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1387 if (*mp) 1388 mp = &(*mp)->m_next; 1389 } 1390 /* ip_srcroute doesn't do what we want here, need to fix */ 1391 if (inp->inp_flags & INP_RECVRETOPTS) { 1392 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1393 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1394 if (*mp) 1395 mp = &(*mp)->m_next; 1396 } 1397 #endif 1398 if (inp->inp_flags & INP_RECVIF) { 1399 struct sockaddr_dl sdl; 1400 1401 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1402 sdl.sdl_family = AF_LINK; 1403 sdl.sdl_index = m->m_pkthdr.rcvif ? 1404 m->m_pkthdr.rcvif->if_index : 0; 1405 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1406 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1407 IP_RECVIF, IPPROTO_IP); 1408 if (*mp) 1409 mp = &(*mp)->m_next; 1410 } 1411 } 1412 1413 int 1414 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1415 int *name; 1416 u_int namelen; 1417 void *oldp; 1418 size_t *oldlenp; 1419 void *newp; 1420 size_t newlen; 1421 { 1422 extern int subnetsarelocal; 1423 1424 int error, old; 1425 1426 /* All sysctl names at this level are terminal. */ 1427 if (namelen != 1) 1428 return (ENOTDIR); 1429 1430 switch (name[0]) { 1431 case IPCTL_FORWARDING: 1432 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1433 case IPCTL_SENDREDIRECTS: 1434 return (sysctl_int(oldp, oldlenp, newp, newlen, 1435 &ipsendredirects)); 1436 case IPCTL_DEFTTL: 1437 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1438 #ifdef notyet 1439 case IPCTL_DEFMTU: 1440 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1441 #endif 1442 case IPCTL_FORWSRCRT: 1443 /* Don't allow this to change in a secure environment. */ 1444 if (securelevel > 0) 1445 return (sysctl_rdint(oldp, oldlenp, newp, 1446 ip_forwsrcrt)); 1447 else 1448 return (sysctl_int(oldp, oldlenp, newp, newlen, 1449 &ip_forwsrcrt)); 1450 case IPCTL_DIRECTEDBCAST: 1451 return (sysctl_int(oldp, oldlenp, newp, newlen, 1452 &ip_directedbcast)); 1453 case IPCTL_ALLOWSRCRT: 1454 return (sysctl_int(oldp, oldlenp, newp, newlen, 1455 &ip_allowsrcrt)); 1456 case IPCTL_SUBNETSARELOCAL: 1457 return (sysctl_int(oldp, oldlenp, newp, newlen, 1458 &subnetsarelocal)); 1459 case IPCTL_MTUDISC: 1460 error = sysctl_int(oldp, oldlenp, newp, newlen, 1461 &ip_mtudisc); 1462 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1463 ip_mtudisc_timeout_q = 1464 rt_timer_queue_create(ip_mtudisc_timeout); 1465 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1466 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1467 ip_mtudisc_timeout_q = NULL; 1468 } 1469 return error; 1470 case IPCTL_ANONPORTMIN: 1471 old = anonportmin; 1472 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1473 if (anonportmin >= anonportmax || anonportmin > 65535 1474 #ifndef IPNOPRIVPORTS 1475 || anonportmin < IPPORT_RESERVED 1476 #endif 1477 ) { 1478 anonportmin = old; 1479 return (EINVAL); 1480 } 1481 return (error); 1482 case IPCTL_ANONPORTMAX: 1483 old = anonportmax; 1484 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1485 if (anonportmin >= anonportmax || anonportmax > 65535 1486 #ifndef IPNOPRIVPORTS 1487 || anonportmax < IPPORT_RESERVED 1488 #endif 1489 ) { 1490 anonportmax = old; 1491 return (EINVAL); 1492 } 1493 return (error); 1494 case IPCTL_MTUDISCTIMEOUT: 1495 error = sysctl_int(oldp, oldlenp, newp, newlen, 1496 &ip_mtudisc_timeout); 1497 if (ip_mtudisc_timeout_q != NULL) 1498 rt_timer_queue_change(ip_mtudisc_timeout_q, 1499 ip_mtudisc_timeout); 1500 return (error); 1501 #ifdef GATEWAY 1502 case IPCTL_MAXFLOWS: 1503 { 1504 int s; 1505 1506 error = sysctl_int(oldp, oldlenp, newp, newlen, 1507 &ip_maxflows); 1508 s = splsoftnet(); 1509 ipflow_reap(0); 1510 splx(s); 1511 return (error); 1512 } 1513 #endif 1514 default: 1515 return (EOPNOTSUPP); 1516 } 1517 /* NOTREACHED */ 1518 } 1519
Indexes created Thu Oct 23 22:10:10 GMT 2025