ip_input.c revision 1.82.2.7
1 /* $NetBSD: ip_input.c,v 1.82.2.7 2001/05/30 09:44:09 he 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 int ip_nfragpackets = 0; 171 int ip_maxfragpackets = 200; 172 173 static __inline int ipq_lock_try __P((void)); 174 static __inline void ipq_unlock __P((void)); 175 176 static __inline int 177 ipq_lock_try() 178 { 179 int s; 180 181 s = splimp(); 182 if (ipq_locked) { 183 splx(s); 184 return (0); 185 } 186 ipq_locked = 1; 187 splx(s); 188 return (1); 189 } 190 191 static __inline void 192 ipq_unlock() 193 { 194 int s; 195 196 s = splimp(); 197 ipq_locked = 0; 198 splx(s); 199 } 200 201 #ifdef DIAGNOSTIC 202 #define IPQ_LOCK() \ 203 do { \ 204 if (ipq_lock_try() == 0) { \ 205 printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \ 206 panic("ipq_lock"); \ 207 } \ 208 } while (0) 209 #define IPQ_LOCK_CHECK() \ 210 do { \ 211 if (ipq_locked == 0) { \ 212 printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \ 213 panic("ipq lock check"); \ 214 } \ 215 } while (0) 216 #else 217 #define IPQ_LOCK() (void) ipq_lock_try() 218 #define IPQ_LOCK_CHECK() /* nothing */ 219 #endif 220 221 #define IPQ_UNLOCK() ipq_unlock() 222 223 struct pool ipqent_pool; 224 225 /* 226 * We need to save the IP options in case a protocol wants to respond 227 * to an incoming packet over the same route if the packet got here 228 * using IP source routing. This allows connection establishment and 229 * maintenance when the remote end is on a network that is not known 230 * to us. 231 */ 232 int ip_nhops = 0; 233 static struct ip_srcrt { 234 struct in_addr dst; /* final destination */ 235 char nop; /* one NOP to align */ 236 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ 237 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; 238 } ip_srcrt; 239 240 static void save_rte __P((u_char *, struct in_addr)); 241 242 /* 243 * IP initialization: fill in IP protocol switch table. 244 * All protocols not implemented in kernel go to raw IP protocol handler. 245 */ 246 void 247 ip_init() 248 { 249 register struct protosw *pr; 250 register int i; 251 252 pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl", 253 0, NULL, NULL, M_IPQ); 254 255 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); 256 if (pr == 0) 257 panic("ip_init"); 258 for (i = 0; i < IPPROTO_MAX; i++) 259 ip_protox[i] = pr - inetsw; 260 for (pr = inetdomain.dom_protosw; 261 pr < inetdomain.dom_protoswNPROTOSW; pr++) 262 if (pr->pr_domain->dom_family == PF_INET && 263 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 264 ip_protox[pr->pr_protocol] = pr - inetsw; 265 LIST_INIT(&ipq); 266 ip_id = time.tv_sec & 0xffff; 267 ipintrq.ifq_maxlen = ipqmaxlen; 268 TAILQ_INIT(&in_ifaddr); 269 in_ifaddrhashtbl = 270 hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash); 271 if (ip_mtudisc != 0) 272 ip_mtudisc_timeout_q = 273 rt_timer_queue_create(ip_mtudisc_timeout); 274 #ifdef GATEWAY 275 ipflow_init(); 276 #endif 277 } 278 279 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 280 struct route ipforward_rt; 281 282 /* 283 * Ip input routine. Checksum and byte swap header. If fragmented 284 * try to reassemble. Process options. Pass to next level. 285 */ 286 void 287 ipintr() 288 { 289 register struct ip *ip = NULL; 290 register struct mbuf *m; 291 register struct ipq *fp; 292 register struct in_ifaddr *ia; 293 register struct ifaddr *ifa; 294 struct ipqent *ipqe; 295 int hlen = 0, mff, len, s; 296 #ifdef PFIL_HOOKS 297 struct packet_filter_hook *pfh; 298 struct mbuf *m0; 299 int rv; 300 #endif /* PFIL_HOOKS */ 301 302 next: 303 /* 304 * Get next datagram off input queue and get IP header 305 * in first mbuf. 306 */ 307 s = splimp(); 308 IF_DEQUEUE(&ipintrq, m); 309 splx(s); 310 if (m == 0) 311 return; 312 #ifdef DIAGNOSTIC 313 if ((m->m_flags & M_PKTHDR) == 0) 314 panic("ipintr no HDR"); 315 #endif 316 /* 317 * If no IP addresses have been set yet but the interfaces 318 * are receiving, can't do anything with incoming packets yet. 319 */ 320 if (in_ifaddr.tqh_first == 0) 321 goto bad; 322 ipstat.ips_total++; 323 if (m->m_len < sizeof (struct ip) && 324 (m = m_pullup(m, sizeof (struct ip))) == 0) { 325 ipstat.ips_toosmall++; 326 goto next; 327 } 328 ip = mtod(m, struct ip *); 329 if (ip->ip_v != IPVERSION) { 330 ipstat.ips_badvers++; 331 goto bad; 332 } 333 hlen = ip->ip_hl << 2; 334 if (hlen < sizeof(struct ip)) { /* minimum header length */ 335 ipstat.ips_badhlen++; 336 goto bad; 337 } 338 if (hlen > m->m_len) { 339 if ((m = m_pullup(m, hlen)) == 0) { 340 ipstat.ips_badhlen++; 341 goto next; 342 } 343 ip = mtod(m, struct ip *); 344 } 345 346 /* 347 * RFC1122: packets with a multicast source address are 348 * not allowed. 349 */ 350 if (IN_MULTICAST(ip->ip_src.s_addr)) { 351 /* XXX stat */ 352 goto bad; 353 } 354 355 if (in_cksum(m, hlen) != 0) { 356 ipstat.ips_badsum++; 357 goto bad; 358 } 359 360 /* 361 * Convert fields to host representation. 362 */ 363 NTOHS(ip->ip_len); 364 NTOHS(ip->ip_off); 365 len = ip->ip_len; 366 367 /* 368 * Check for additional length bogosity 369 */ 370 if (len < hlen) 371 { 372 ipstat.ips_badlen++; 373 goto bad; 374 } 375 376 /* 377 * Check that the amount of data in the buffers 378 * is as at least much as the IP header would have us expect. 379 * Trim mbufs if longer than we expect. 380 * Drop packet if shorter than we expect. 381 */ 382 if (m->m_pkthdr.len < len) { 383 ipstat.ips_tooshort++; 384 goto bad; 385 } 386 if (m->m_pkthdr.len > len) { 387 if (m->m_len == m->m_pkthdr.len) { 388 m->m_len = len; 389 m->m_pkthdr.len = len; 390 } else 391 m_adj(m, len - m->m_pkthdr.len); 392 } 393 394 /* 395 * Assume that we can create a fast-forward IP flow entry 396 * based on this packet. 397 */ 398 m->m_flags |= M_CANFASTFWD; 399 400 #ifdef PFIL_HOOKS 401 /* 402 * Run through list of hooks for input packets. If there are any 403 * filters which require that additional packets in the flow are 404 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 405 * Note that filters must _never_ set this flag, as another filter 406 * in the list may have previously cleared it. 407 */ 408 m0 = m; 409 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next) 410 if (pfh->pfil_func) { 411 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0); 412 if (rv) 413 goto next; 414 m = m0; 415 if (m == NULL) 416 goto next; 417 ip = mtod(m, struct ip *); 418 } 419 #endif /* PFIL_HOOKS */ 420 421 /* 422 * Process options and, if not destined for us, 423 * ship it on. ip_dooptions returns 1 when an 424 * error was detected (causing an icmp message 425 * to be sent and the original packet to be freed). 426 */ 427 ip_nhops = 0; /* for source routed packets */ 428 if (hlen > sizeof (struct ip) && ip_dooptions(m)) 429 goto next; 430 431 /* 432 * Check our list of addresses, to see if the packet is for us. 433 */ 434 INADDR_TO_IA(ip->ip_dst, ia); 435 if (ia != NULL) 436 goto ours; 437 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) { 438 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 439 ifa != NULL; ifa = ifa->ifa_list.tqe_next) { 440 if (ifa->ifa_addr->sa_family != AF_INET) continue; 441 ia = ifatoia(ifa); 442 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) || 443 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) || 444 /* 445 * Look for all-0's host part (old broadcast addr), 446 * either for subnet or net. 447 */ 448 ip->ip_dst.s_addr == ia->ia_subnet || 449 ip->ip_dst.s_addr == ia->ia_net) 450 goto ours; 451 /* 452 * An interface with IP address zero accepts 453 * all packets that arrive on that interface. 454 */ 455 if (in_nullhost(ia->ia_addr.sin_addr)) 456 goto ours; 457 } 458 } 459 if (IN_MULTICAST(ip->ip_dst.s_addr)) { 460 struct in_multi *inm; 461 #ifdef MROUTING 462 extern struct socket *ip_mrouter; 463 464 if (m->m_flags & M_EXT) { 465 if ((m = m_pullup(m, hlen)) == 0) { 466 ipstat.ips_toosmall++; 467 goto next; 468 } 469 ip = mtod(m, struct ip *); 470 } 471 472 if (ip_mrouter) { 473 /* 474 * If we are acting as a multicast router, all 475 * incoming multicast packets are passed to the 476 * kernel-level multicast forwarding function. 477 * The packet is returned (relatively) intact; if 478 * ip_mforward() returns a non-zero value, the packet 479 * must be discarded, else it may be accepted below. 480 * 481 * (The IP ident field is put in the same byte order 482 * as expected when ip_mforward() is called from 483 * ip_output().) 484 */ 485 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { 486 ipstat.ips_cantforward++; 487 m_freem(m); 488 goto next; 489 } 490 491 /* 492 * The process-level routing demon needs to receive 493 * all multicast IGMP packets, whether or not this 494 * host belongs to their destination groups. 495 */ 496 if (ip->ip_p == IPPROTO_IGMP) 497 goto ours; 498 ipstat.ips_forward++; 499 } 500 #endif 501 /* 502 * See if we belong to the destination multicast group on the 503 * arrival interface. 504 */ 505 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); 506 if (inm == NULL) { 507 ipstat.ips_cantforward++; 508 m_freem(m); 509 goto next; 510 } 511 goto ours; 512 } 513 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 514 in_nullhost(ip->ip_dst)) 515 goto ours; 516 517 /* 518 * Not for us; forward if possible and desirable. 519 */ 520 if (ipforwarding == 0) { 521 ipstat.ips_cantforward++; 522 m_freem(m); 523 } else 524 ip_forward(m, 0); 525 goto next; 526 527 ours: 528 /* 529 * If offset or IP_MF are set, must reassemble. 530 * Otherwise, nothing need be done. 531 * (We could look in the reassembly queue to see 532 * if the packet was previously fragmented, 533 * but it's not worth the time; just let them time out.) 534 */ 535 if (ip->ip_off & ~(IP_DF|IP_RF)) { 536 /* 537 * Look for queue of fragments 538 * of this datagram. 539 */ 540 IPQ_LOCK(); 541 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next) 542 if (ip->ip_id == fp->ipq_id && 543 in_hosteq(ip->ip_src, fp->ipq_src) && 544 in_hosteq(ip->ip_dst, fp->ipq_dst) && 545 ip->ip_p == fp->ipq_p) 546 goto found; 547 fp = 0; 548 found: 549 550 /* 551 * Adjust ip_len to not reflect header, 552 * set ipqe_mff if more fragments are expected, 553 * convert offset of this to bytes. 554 */ 555 ip->ip_len -= hlen; 556 mff = (ip->ip_off & IP_MF) != 0; 557 if (mff) { 558 /* 559 * Make sure that fragments have a data length 560 * that's a non-zero multiple of 8 bytes. 561 */ 562 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) { 563 ipstat.ips_badfrags++; 564 IPQ_UNLOCK(); 565 goto bad; 566 } 567 } 568 ip->ip_off <<= 3; 569 570 /* 571 * If datagram marked as having more fragments 572 * or if this is not the first fragment, 573 * attempt reassembly; if it succeeds, proceed. 574 */ 575 if (mff || ip->ip_off) { 576 ipstat.ips_fragments++; 577 ipqe = pool_get(&ipqent_pool, PR_NOWAIT); 578 if (ipqe == NULL) { 579 ipstat.ips_rcvmemdrop++; 580 IPQ_UNLOCK(); 581 goto bad; 582 } 583 ipqe->ipqe_mff = mff; 584 ipqe->ipqe_m = m; 585 ipqe->ipqe_ip = ip; 586 m = ip_reass(ipqe, fp); 587 if (m == 0) { 588 IPQ_UNLOCK(); 589 goto next; 590 } 591 ipstat.ips_reassembled++; 592 ip = mtod(m, struct ip *); 593 hlen = ip->ip_hl << 2; 594 ip->ip_len += hlen; 595 } else 596 if (fp) 597 ip_freef(fp); 598 IPQ_UNLOCK(); 599 } 600 601 /* 602 * Switch out to protocol's input routine. 603 */ 604 #if IFA_STATS 605 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len; 606 #endif 607 ipstat.ips_delivered++; 608 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); 609 goto next; 610 bad: 611 m_freem(m); 612 goto next; 613 } 614 615 /* 616 * Take incoming datagram fragment and try to 617 * reassemble it into whole datagram. If a chain for 618 * reassembly of this datagram already exists, then it 619 * is given as fp; otherwise have to make a chain. 620 */ 621 struct mbuf * 622 ip_reass(ipqe, fp) 623 register struct ipqent *ipqe; 624 register struct ipq *fp; 625 { 626 register struct mbuf *m = ipqe->ipqe_m; 627 register struct ipqent *nq, *p, *q; 628 struct ip *ip; 629 struct mbuf *t; 630 int hlen = ipqe->ipqe_ip->ip_hl << 2; 631 int i, next; 632 633 IPQ_LOCK_CHECK(); 634 635 /* 636 * Presence of header sizes in mbufs 637 * would confuse code below. 638 */ 639 m->m_data += hlen; 640 m->m_len -= hlen; 641 642 /* 643 * If first fragment to arrive, create a reassembly queue. 644 */ 645 if (fp == 0) { 646 /* 647 * Enforce upper bound on number of fragmented packets 648 * for which we attempt reassembly; 649 * If maxfrag is 0, never accept fragments. 650 * If maxfrag is -1, accept all fragments without limitation. 651 */ 652 if (ip_maxfragpackets < 0) 653 ; 654 else if (ip_nfragpackets >= ip_maxfragpackets) 655 goto dropfrag; 656 ip_nfragpackets++; 657 MALLOC(fp, struct ipq *, sizeof (struct ipq), 658 M_FTABLE, M_NOWAIT); 659 if (fp == NULL) 660 goto dropfrag; 661 LIST_INSERT_HEAD(&ipq, fp, ipq_q); 662 fp->ipq_ttl = IPFRAGTTL; 663 fp->ipq_p = ipqe->ipqe_ip->ip_p; 664 fp->ipq_id = ipqe->ipqe_ip->ip_id; 665 LIST_INIT(&fp->ipq_fragq); 666 fp->ipq_src = ipqe->ipqe_ip->ip_src; 667 fp->ipq_dst = ipqe->ipqe_ip->ip_dst; 668 p = NULL; 669 goto insert; 670 } 671 672 /* 673 * Find a segment which begins after this one does. 674 */ 675 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 676 p = q, q = q->ipqe_q.le_next) 677 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off) 678 break; 679 680 /* 681 * If there is a preceding segment, it may provide some of 682 * our data already. If so, drop the data from the incoming 683 * segment. If it provides all of our data, drop us. 684 */ 685 if (p != NULL) { 686 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len - 687 ipqe->ipqe_ip->ip_off; 688 if (i > 0) { 689 if (i >= ipqe->ipqe_ip->ip_len) 690 goto dropfrag; 691 m_adj(ipqe->ipqe_m, i); 692 ipqe->ipqe_ip->ip_off += i; 693 ipqe->ipqe_ip->ip_len -= i; 694 } 695 } 696 697 /* 698 * While we overlap succeeding segments trim them or, 699 * if they are completely covered, dequeue them. 700 */ 701 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len > 702 q->ipqe_ip->ip_off; q = nq) { 703 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) - 704 q->ipqe_ip->ip_off; 705 if (i < q->ipqe_ip->ip_len) { 706 q->ipqe_ip->ip_len -= i; 707 q->ipqe_ip->ip_off += i; 708 m_adj(q->ipqe_m, i); 709 break; 710 } 711 nq = q->ipqe_q.le_next; 712 m_freem(q->ipqe_m); 713 LIST_REMOVE(q, ipqe_q); 714 pool_put(&ipqent_pool, q); 715 } 716 717 insert: 718 /* 719 * Stick new segment in its place; 720 * check for complete reassembly. 721 */ 722 if (p == NULL) { 723 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q); 724 } else { 725 LIST_INSERT_AFTER(p, ipqe, ipqe_q); 726 } 727 next = 0; 728 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL; 729 p = q, q = q->ipqe_q.le_next) { 730 if (q->ipqe_ip->ip_off != next) 731 return (0); 732 next += q->ipqe_ip->ip_len; 733 } 734 if (p->ipqe_mff) 735 return (0); 736 737 /* 738 * Reassembly is complete. Check for a bogus message size and 739 * concatenate fragments. 740 */ 741 q = fp->ipq_fragq.lh_first; 742 ip = q->ipqe_ip; 743 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) { 744 ipstat.ips_toolong++; 745 ip_freef(fp); 746 return (0); 747 } 748 m = q->ipqe_m; 749 t = m->m_next; 750 m->m_next = 0; 751 m_cat(m, t); 752 nq = q->ipqe_q.le_next; 753 pool_put(&ipqent_pool, q); 754 for (q = nq; q != NULL; q = nq) { 755 t = q->ipqe_m; 756 nq = q->ipqe_q.le_next; 757 pool_put(&ipqent_pool, q); 758 m_cat(m, t); 759 } 760 761 /* 762 * Create header for new ip packet by 763 * modifying header of first packet; 764 * dequeue and discard fragment reassembly header. 765 * Make header visible. 766 */ 767 ip->ip_len = next; 768 ip->ip_src = fp->ipq_src; 769 ip->ip_dst = fp->ipq_dst; 770 LIST_REMOVE(fp, ipq_q); 771 FREE(fp, M_FTABLE); 772 ip_nfragpackets--; 773 m->m_len += (ip->ip_hl << 2); 774 m->m_data -= (ip->ip_hl << 2); 775 /* some debugging cruft by sklower, below, will go away soon */ 776 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ 777 register int plen = 0; 778 for (t = m; t; t = t->m_next) 779 plen += t->m_len; 780 m->m_pkthdr.len = plen; 781 } 782 return (m); 783 784 dropfrag: 785 ipstat.ips_fragdropped++; 786 m_freem(m); 787 pool_put(&ipqent_pool, ipqe); 788 return (0); 789 } 790 791 /* 792 * Free a fragment reassembly header and all 793 * associated datagrams. 794 */ 795 void 796 ip_freef(fp) 797 struct ipq *fp; 798 { 799 register struct ipqent *q, *p; 800 801 IPQ_LOCK_CHECK(); 802 803 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) { 804 p = q->ipqe_q.le_next; 805 m_freem(q->ipqe_m); 806 LIST_REMOVE(q, ipqe_q); 807 pool_put(&ipqent_pool, q); 808 } 809 LIST_REMOVE(fp, ipq_q); 810 FREE(fp, M_FTABLE); 811 ip_nfragpackets--; 812 } 813 814 /* 815 * IP timer processing; 816 * if a timer expires on a reassembly 817 * queue, discard it. 818 */ 819 void 820 ip_slowtimo() 821 { 822 register struct ipq *fp, *nfp; 823 int s = splsoftnet(); 824 825 IPQ_LOCK(); 826 for (fp = ipq.lh_first; fp != NULL; fp = nfp) { 827 nfp = fp->ipq_q.le_next; 828 if (--fp->ipq_ttl == 0) { 829 ipstat.ips_fragtimeout++; 830 ip_freef(fp); 831 } 832 } 833 /* 834 * If we are over the maximum number of fragments 835 * (due to the limit being lowered), drain off 836 * enough to get down to the new limit. 837 */ 838 if (ip_maxfragpackets < 0) 839 ; 840 else { 841 while (ip_nfragpackets > ip_maxfragpackets && ipq.lh_first) 842 ip_freef(ipq.lh_first); 843 } 844 IPQ_UNLOCK(); 845 #ifdef GATEWAY 846 ipflow_slowtimo(); 847 #endif 848 splx(s); 849 } 850 851 /* 852 * Drain off all datagram fragments. 853 */ 854 void 855 ip_drain() 856 { 857 858 /* 859 * We may be called from a device's interrupt context. If 860 * the ipq is already busy, just bail out now. 861 */ 862 if (ipq_lock_try() == 0) 863 return; 864 865 while (ipq.lh_first != NULL) { 866 ipstat.ips_fragdropped++; 867 ip_freef(ipq.lh_first); 868 } 869 870 IPQ_UNLOCK(); 871 } 872 873 /* 874 * Do option processing on a datagram, 875 * possibly discarding it if bad options are encountered, 876 * or forwarding it if source-routed. 877 * Returns 1 if packet has been forwarded/freed, 878 * 0 if the packet should be processed further. 879 */ 880 int 881 ip_dooptions(m) 882 struct mbuf *m; 883 { 884 register struct ip *ip = mtod(m, struct ip *); 885 register u_char *cp, *cp0; 886 register struct ip_timestamp *ipt; 887 register struct in_ifaddr *ia; 888 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 889 struct in_addr dst; 890 n_time ntime; 891 892 dst = ip->ip_dst; 893 cp = (u_char *)(ip + 1); 894 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 895 for (; cnt > 0; cnt -= optlen, cp += optlen) { 896 opt = cp[IPOPT_OPTVAL]; 897 if (opt == IPOPT_EOL) 898 break; 899 if (opt == IPOPT_NOP) 900 optlen = 1; 901 else { 902 optlen = cp[IPOPT_OLEN]; 903 if (optlen <= 0 || optlen > cnt) { 904 code = &cp[IPOPT_OLEN] - (u_char *)ip; 905 goto bad; 906 } 907 } 908 switch (opt) { 909 910 default: 911 break; 912 913 /* 914 * Source routing with record. 915 * Find interface with current destination address. 916 * If none on this machine then drop if strictly routed, 917 * or do nothing if loosely routed. 918 * Record interface address and bring up next address 919 * component. If strictly routed make sure next 920 * address is on directly accessible net. 921 */ 922 case IPOPT_LSRR: 923 case IPOPT_SSRR: 924 if (ip_allowsrcrt == 0) { 925 type = ICMP_UNREACH; 926 code = ICMP_UNREACH_NET_PROHIB; 927 goto bad; 928 } 929 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 930 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 931 goto bad; 932 } 933 ipaddr.sin_addr = ip->ip_dst; 934 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))); 935 if (ia == 0) { 936 if (opt == IPOPT_SSRR) { 937 type = ICMP_UNREACH; 938 code = ICMP_UNREACH_SRCFAIL; 939 goto bad; 940 } 941 /* 942 * Loose routing, and not at next destination 943 * yet; nothing to do except forward. 944 */ 945 break; 946 } 947 off--; /* 0 origin */ 948 if ((off + sizeof(struct in_addr)) > optlen) { 949 /* 950 * End of source route. Should be for us. 951 */ 952 save_rte(cp, ip->ip_src); 953 break; 954 } 955 /* 956 * locate outgoing interface 957 */ 958 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, 959 sizeof(ipaddr.sin_addr)); 960 if (opt == IPOPT_SSRR) { 961 #define INA struct in_ifaddr * 962 #define SA struct sockaddr * 963 ia = (INA)ifa_ifwithladdr((SA)&ipaddr); 964 } else 965 ia = ip_rtaddr(ipaddr.sin_addr); 966 if (ia == 0) { 967 type = ICMP_UNREACH; 968 code = ICMP_UNREACH_SRCFAIL; 969 goto bad; 970 } 971 ip->ip_dst = ipaddr.sin_addr; 972 bcopy((caddr_t)&ia->ia_addr.sin_addr, 973 (caddr_t)(cp + off), sizeof(struct in_addr)); 974 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 975 /* 976 * Let ip_intr's mcast routing check handle mcast pkts 977 */ 978 forward = !IN_MULTICAST(ip->ip_dst.s_addr); 979 break; 980 981 case IPOPT_RR: 982 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 983 code = &cp[IPOPT_OFFSET] - (u_char *)ip; 984 goto bad; 985 } 986 /* 987 * If no space remains, ignore. 988 */ 989 off--; /* 0 origin */ 990 if ((off + sizeof(struct in_addr)) > optlen) 991 break; 992 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, 993 sizeof(ipaddr.sin_addr)); 994 /* 995 * locate outgoing interface; if we're the destination, 996 * use the incoming interface (should be same). 997 */ 998 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && 999 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { 1000 type = ICMP_UNREACH; 1001 code = ICMP_UNREACH_HOST; 1002 goto bad; 1003 } 1004 bcopy((caddr_t)&ia->ia_addr.sin_addr, 1005 (caddr_t)(cp + off), sizeof(struct in_addr)); 1006 cp[IPOPT_OFFSET] += sizeof(struct in_addr); 1007 break; 1008 1009 case IPOPT_TS: 1010 code = cp - (u_char *)ip; 1011 ipt = (struct ip_timestamp *)cp; 1012 if (ipt->ipt_len < 5) 1013 goto bad; 1014 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { 1015 if (++ipt->ipt_oflw == 0) 1016 goto bad; 1017 break; 1018 } 1019 cp0 = (cp + ipt->ipt_ptr - 1); 1020 switch (ipt->ipt_flg) { 1021 1022 case IPOPT_TS_TSONLY: 1023 break; 1024 1025 case IPOPT_TS_TSANDADDR: 1026 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1027 sizeof(struct in_addr) > ipt->ipt_len) 1028 goto bad; 1029 ipaddr.sin_addr = dst; 1030 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 1031 m->m_pkthdr.rcvif); 1032 if (ia == 0) 1033 continue; 1034 bcopy(&ia->ia_addr.sin_addr, 1035 cp0, sizeof(struct in_addr)); 1036 ipt->ipt_ptr += sizeof(struct in_addr); 1037 break; 1038 1039 case IPOPT_TS_PRESPEC: 1040 if (ipt->ipt_ptr - 1 + sizeof(n_time) + 1041 sizeof(struct in_addr) > ipt->ipt_len) 1042 goto bad; 1043 bcopy(cp0, &ipaddr.sin_addr, 1044 sizeof(struct in_addr)); 1045 if (ifa_ifwithaddr((SA)&ipaddr) == 0) 1046 continue; 1047 ipt->ipt_ptr += sizeof(struct in_addr); 1048 break; 1049 1050 default: 1051 goto bad; 1052 } 1053 ntime = iptime(); 1054 cp0 = (u_char *) &ntime; /* XXX GCC BUG */ 1055 bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1, 1056 sizeof(n_time)); 1057 ipt->ipt_ptr += sizeof(n_time); 1058 } 1059 } 1060 if (forward) { 1061 if (ip_forwsrcrt == 0) { 1062 type = ICMP_UNREACH; 1063 code = ICMP_UNREACH_SRCFAIL; 1064 goto bad; 1065 } 1066 ip_forward(m, 1); 1067 return (1); 1068 } 1069 return (0); 1070 bad: 1071 icmp_error(m, type, code, 0, 0); 1072 ipstat.ips_badoptions++; 1073 return (1); 1074 } 1075 1076 /* 1077 * Given address of next destination (final or next hop), 1078 * return internet address info of interface to be used to get there. 1079 */ 1080 struct in_ifaddr * 1081 ip_rtaddr(dst) 1082 struct in_addr dst; 1083 { 1084 register struct sockaddr_in *sin; 1085 1086 sin = satosin(&ipforward_rt.ro_dst); 1087 1088 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) { 1089 if (ipforward_rt.ro_rt) { 1090 RTFREE(ipforward_rt.ro_rt); 1091 ipforward_rt.ro_rt = 0; 1092 } 1093 sin->sin_family = AF_INET; 1094 sin->sin_len = sizeof(*sin); 1095 sin->sin_addr = dst; 1096 1097 rtalloc(&ipforward_rt); 1098 } 1099 if (ipforward_rt.ro_rt == 0) 1100 return ((struct in_ifaddr *)0); 1101 return (ifatoia(ipforward_rt.ro_rt->rt_ifa)); 1102 } 1103 1104 /* 1105 * Save incoming source route for use in replies, 1106 * to be picked up later by ip_srcroute if the receiver is interested. 1107 */ 1108 void 1109 save_rte(option, dst) 1110 u_char *option; 1111 struct in_addr dst; 1112 { 1113 unsigned olen; 1114 1115 olen = option[IPOPT_OLEN]; 1116 #ifdef DIAGNOSTIC 1117 if (ipprintfs) 1118 printf("save_rte: olen %d\n", olen); 1119 #endif 1120 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) 1121 return; 1122 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); 1123 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 1124 ip_srcrt.dst = dst; 1125 } 1126 1127 /* 1128 * Retrieve incoming source route for use in replies, 1129 * in the same form used by setsockopt. 1130 * The first hop is placed before the options, will be removed later. 1131 */ 1132 struct mbuf * 1133 ip_srcroute() 1134 { 1135 register struct in_addr *p, *q; 1136 register struct mbuf *m; 1137 1138 if (ip_nhops == 0) 1139 return ((struct mbuf *)0); 1140 m = m_get(M_DONTWAIT, MT_SOOPTS); 1141 if (m == 0) 1142 return ((struct mbuf *)0); 1143 1144 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) 1145 1146 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 1147 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + 1148 OPTSIZ; 1149 #ifdef DIAGNOSTIC 1150 if (ipprintfs) 1151 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); 1152 #endif 1153 1154 /* 1155 * First save first hop for return route 1156 */ 1157 p = &ip_srcrt.route[ip_nhops - 1]; 1158 *(mtod(m, struct in_addr *)) = *p--; 1159 #ifdef DIAGNOSTIC 1160 if (ipprintfs) 1161 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr)); 1162 #endif 1163 1164 /* 1165 * Copy option fields and padding (nop) to mbuf. 1166 */ 1167 ip_srcrt.nop = IPOPT_NOP; 1168 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 1169 bcopy((caddr_t)&ip_srcrt.nop, 1170 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); 1171 q = (struct in_addr *)(mtod(m, caddr_t) + 1172 sizeof(struct in_addr) + OPTSIZ); 1173 #undef OPTSIZ 1174 /* 1175 * Record return path as an IP source route, 1176 * reversing the path (pointers are now aligned). 1177 */ 1178 while (p >= ip_srcrt.route) { 1179 #ifdef DIAGNOSTIC 1180 if (ipprintfs) 1181 printf(" %x", ntohl(q->s_addr)); 1182 #endif 1183 *q++ = *p--; 1184 } 1185 /* 1186 * Last hop goes to final destination. 1187 */ 1188 *q = ip_srcrt.dst; 1189 #ifdef DIAGNOSTIC 1190 if (ipprintfs) 1191 printf(" %x\n", ntohl(q->s_addr)); 1192 #endif 1193 return (m); 1194 } 1195 1196 /* 1197 * Strip out IP options, at higher 1198 * level protocol in the kernel. 1199 * Second argument is buffer to which options 1200 * will be moved, and return value is their length. 1201 * XXX should be deleted; last arg currently ignored. 1202 */ 1203 void 1204 ip_stripoptions(m, mopt) 1205 register struct mbuf *m; 1206 struct mbuf *mopt; 1207 { 1208 register int i; 1209 struct ip *ip = mtod(m, struct ip *); 1210 register caddr_t opts; 1211 int olen; 1212 1213 olen = (ip->ip_hl << 2) - sizeof (struct ip); 1214 opts = (caddr_t)(ip + 1); 1215 i = m->m_len - (sizeof (struct ip) + olen); 1216 bcopy(opts + olen, opts, (unsigned)i); 1217 m->m_len -= olen; 1218 if (m->m_flags & M_PKTHDR) 1219 m->m_pkthdr.len -= olen; 1220 ip->ip_len -= olen; 1221 ip->ip_hl = sizeof (struct ip) >> 2; 1222 } 1223 1224 int inetctlerrmap[PRC_NCMDS] = { 1225 0, 0, 0, 0, 1226 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1227 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1228 EMSGSIZE, EHOSTUNREACH, 0, 0, 1229 0, 0, 0, 0, 1230 ENOPROTOOPT 1231 }; 1232 1233 /* 1234 * Forward a packet. If some error occurs return the sender 1235 * an icmp packet. Note we can't always generate a meaningful 1236 * icmp message because icmp doesn't have a large enough repertoire 1237 * of codes and types. 1238 * 1239 * If not forwarding, just drop the packet. This could be confusing 1240 * if ipforwarding was zero but some routing protocol was advancing 1241 * us as a gateway to somewhere. However, we must let the routing 1242 * protocol deal with that. 1243 * 1244 * The srcrt parameter indicates whether the packet is being forwarded 1245 * via a source route. 1246 */ 1247 void 1248 ip_forward(m, srcrt) 1249 struct mbuf *m; 1250 int srcrt; 1251 { 1252 register struct ip *ip = mtod(m, struct ip *); 1253 register struct sockaddr_in *sin; 1254 register struct rtentry *rt; 1255 int error, type = 0, code = 0; 1256 struct mbuf *mcopy; 1257 n_long dest; 1258 struct ifnet *destifp; 1259 1260 dest = 0; 1261 #ifdef DIAGNOSTIC 1262 if (ipprintfs) 1263 printf("forward: src %2.2x dst %2.2x ttl %x\n", 1264 ntohl(ip->ip_src.s_addr), 1265 ntohl(ip->ip_dst.s_addr), ip->ip_ttl); 1266 #endif 1267 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) { 1268 ipstat.ips_cantforward++; 1269 m_freem(m); 1270 return; 1271 } 1272 if (ip->ip_ttl <= IPTTLDEC) { 1273 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); 1274 return; 1275 } 1276 ip->ip_ttl -= IPTTLDEC; 1277 1278 sin = satosin(&ipforward_rt.ro_dst); 1279 if ((rt = ipforward_rt.ro_rt) == 0 || 1280 !in_hosteq(ip->ip_dst, sin->sin_addr)) { 1281 if (ipforward_rt.ro_rt) { 1282 RTFREE(ipforward_rt.ro_rt); 1283 ipforward_rt.ro_rt = 0; 1284 } 1285 sin->sin_family = AF_INET; 1286 sin->sin_len = sizeof(struct sockaddr_in); 1287 sin->sin_addr = ip->ip_dst; 1288 1289 rtalloc(&ipforward_rt); 1290 if (ipforward_rt.ro_rt == 0) { 1291 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); 1292 return; 1293 } 1294 rt = ipforward_rt.ro_rt; 1295 } 1296 1297 /* 1298 * Save at most 68 bytes of the packet in case 1299 * we need to generate an ICMP message to the src. 1300 */ 1301 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68)); 1302 1303 /* 1304 * If forwarding packet using same interface that it came in on, 1305 * perhaps should send a redirect to sender to shortcut a hop. 1306 * Only send redirect if source is sending directly to us, 1307 * and if packet was not source routed (or has any options). 1308 * Also, don't send redirect if forwarding using a default route 1309 * or a route modified by a redirect. 1310 */ 1311 if (rt->rt_ifp == m->m_pkthdr.rcvif && 1312 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && 1313 !in_nullhost(satosin(rt_key(rt))->sin_addr) && 1314 ipsendredirects && !srcrt) { 1315 if (rt->rt_ifa && 1316 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) == 1317 ifatoia(rt->rt_ifa)->ia_subnet) { 1318 if (rt->rt_flags & RTF_GATEWAY) 1319 dest = satosin(rt->rt_gateway)->sin_addr.s_addr; 1320 else 1321 dest = ip->ip_dst.s_addr; 1322 /* 1323 * Router requirements says to only send host 1324 * redirects. 1325 */ 1326 type = ICMP_REDIRECT; 1327 code = ICMP_REDIRECT_HOST; 1328 #ifdef DIAGNOSTIC 1329 if (ipprintfs) 1330 printf("redirect (%d) to %x\n", code, 1331 (u_int32_t)dest); 1332 #endif 1333 } 1334 } 1335 1336 error = ip_output(m, (struct mbuf *)0, &ipforward_rt, 1337 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0); 1338 if (error) 1339 ipstat.ips_cantforward++; 1340 else { 1341 ipstat.ips_forward++; 1342 if (type) 1343 ipstat.ips_redirectsent++; 1344 else { 1345 if (mcopy) { 1346 #ifdef GATEWAY 1347 if (mcopy->m_flags & M_CANFASTFWD) 1348 ipflow_create(&ipforward_rt, mcopy); 1349 #endif 1350 m_freem(mcopy); 1351 } 1352 return; 1353 } 1354 } 1355 if (mcopy == NULL) 1356 return; 1357 destifp = NULL; 1358 1359 switch (error) { 1360 1361 case 0: /* forwarded, but need redirect */ 1362 /* type, code set above */ 1363 break; 1364 1365 case ENETUNREACH: /* shouldn't happen, checked above */ 1366 case EHOSTUNREACH: 1367 case ENETDOWN: 1368 case EHOSTDOWN: 1369 default: 1370 type = ICMP_UNREACH; 1371 code = ICMP_UNREACH_HOST; 1372 break; 1373 1374 case EMSGSIZE: 1375 type = ICMP_UNREACH; 1376 code = ICMP_UNREACH_NEEDFRAG; 1377 if (ipforward_rt.ro_rt) 1378 destifp = ipforward_rt.ro_rt->rt_ifp; 1379 ipstat.ips_cantfrag++; 1380 break; 1381 1382 case ENOBUFS: 1383 type = ICMP_SOURCEQUENCH; 1384 code = 0; 1385 break; 1386 } 1387 icmp_error(mcopy, type, code, dest, destifp); 1388 } 1389 1390 void 1391 ip_savecontrol(inp, mp, ip, m) 1392 register struct inpcb *inp; 1393 register struct mbuf **mp; 1394 register struct ip *ip; 1395 register struct mbuf *m; 1396 { 1397 1398 if (inp->inp_socket->so_options & SO_TIMESTAMP) { 1399 struct timeval tv; 1400 1401 microtime(&tv); 1402 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1403 SCM_TIMESTAMP, SOL_SOCKET); 1404 if (*mp) 1405 mp = &(*mp)->m_next; 1406 } 1407 if (inp->inp_flags & INP_RECVDSTADDR) { 1408 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, 1409 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); 1410 if (*mp) 1411 mp = &(*mp)->m_next; 1412 } 1413 #ifdef notyet 1414 /* 1415 * XXX 1416 * Moving these out of udp_input() made them even more broken 1417 * than they already were. 1418 * - fenner (at) parc.xerox.com 1419 */ 1420 /* options were tossed already */ 1421 if (inp->inp_flags & INP_RECVOPTS) { 1422 *mp = sbcreatecontrol((caddr_t) opts_deleted_above, 1423 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); 1424 if (*mp) 1425 mp = &(*mp)->m_next; 1426 } 1427 /* ip_srcroute doesn't do what we want here, need to fix */ 1428 if (inp->inp_flags & INP_RECVRETOPTS) { 1429 *mp = sbcreatecontrol((caddr_t) ip_srcroute(), 1430 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); 1431 if (*mp) 1432 mp = &(*mp)->m_next; 1433 } 1434 #endif 1435 if (inp->inp_flags & INP_RECVIF) { 1436 struct sockaddr_dl sdl; 1437 1438 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); 1439 sdl.sdl_family = AF_LINK; 1440 sdl.sdl_index = m->m_pkthdr.rcvif ? 1441 m->m_pkthdr.rcvif->if_index : 0; 1442 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; 1443 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, 1444 IP_RECVIF, IPPROTO_IP); 1445 if (*mp) 1446 mp = &(*mp)->m_next; 1447 } 1448 } 1449 1450 int 1451 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1452 int *name; 1453 u_int namelen; 1454 void *oldp; 1455 size_t *oldlenp; 1456 void *newp; 1457 size_t newlen; 1458 { 1459 extern int subnetsarelocal; 1460 1461 int error, old; 1462 1463 /* All sysctl names at this level are terminal. */ 1464 if (namelen != 1) 1465 return (ENOTDIR); 1466 1467 switch (name[0]) { 1468 case IPCTL_FORWARDING: 1469 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding)); 1470 case IPCTL_SENDREDIRECTS: 1471 return (sysctl_int(oldp, oldlenp, newp, newlen, 1472 &ipsendredirects)); 1473 case IPCTL_DEFTTL: 1474 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl)); 1475 #ifdef notyet 1476 case IPCTL_DEFMTU: 1477 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu)); 1478 #endif 1479 case IPCTL_FORWSRCRT: 1480 /* Don't allow this to change in a secure environment. */ 1481 if (securelevel > 0) 1482 return (sysctl_rdint(oldp, oldlenp, newp, 1483 ip_forwsrcrt)); 1484 else 1485 return (sysctl_int(oldp, oldlenp, newp, newlen, 1486 &ip_forwsrcrt)); 1487 case IPCTL_DIRECTEDBCAST: 1488 return (sysctl_int(oldp, oldlenp, newp, newlen, 1489 &ip_directedbcast)); 1490 case IPCTL_ALLOWSRCRT: 1491 return (sysctl_int(oldp, oldlenp, newp, newlen, 1492 &ip_allowsrcrt)); 1493 case IPCTL_SUBNETSARELOCAL: 1494 return (sysctl_int(oldp, oldlenp, newp, newlen, 1495 &subnetsarelocal)); 1496 case IPCTL_MTUDISC: 1497 error = sysctl_int(oldp, oldlenp, newp, newlen, 1498 &ip_mtudisc); 1499 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) { 1500 ip_mtudisc_timeout_q = 1501 rt_timer_queue_create(ip_mtudisc_timeout); 1502 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) { 1503 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE); 1504 ip_mtudisc_timeout_q = NULL; 1505 } 1506 return error; 1507 case IPCTL_ANONPORTMIN: 1508 old = anonportmin; 1509 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin); 1510 if (anonportmin >= anonportmax || anonportmin > 65535 1511 #ifndef IPNOPRIVPORTS 1512 || anonportmin < IPPORT_RESERVED 1513 #endif 1514 ) { 1515 anonportmin = old; 1516 return (EINVAL); 1517 } 1518 return (error); 1519 case IPCTL_ANONPORTMAX: 1520 old = anonportmax; 1521 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax); 1522 if (anonportmin >= anonportmax || anonportmax > 65535 1523 #ifndef IPNOPRIVPORTS 1524 || anonportmax < IPPORT_RESERVED 1525 #endif 1526 ) { 1527 anonportmax = old; 1528 return (EINVAL); 1529 } 1530 return (error); 1531 case IPCTL_MTUDISCTIMEOUT: 1532 error = sysctl_int(oldp, oldlenp, newp, newlen, 1533 &ip_mtudisc_timeout); 1534 if (ip_mtudisc_timeout_q != NULL) 1535 rt_timer_queue_change(ip_mtudisc_timeout_q, 1536 ip_mtudisc_timeout); 1537 return (error); 1538 #ifdef GATEWAY 1539 case IPCTL_MAXFLOWS: 1540 { 1541 int s; 1542 1543 error = sysctl_int(oldp, oldlenp, newp, newlen, 1544 &ip_maxflows); 1545 s = splsoftnet(); 1546 ipflow_reap(0); 1547 splx(s); 1548 return (error); 1549 } 1550 #endif 1551 1552 case IPCTL_MAXFRAGPACKETS: 1553 return (sysctl_int(oldp, oldlenp, newp, newlen, 1554 &ip_maxfragpackets)); 1555 1556 default: 1557 return (EOPNOTSUPP); 1558 } 1559 /* NOTREACHED */ 1560 } 1561
Indexes created Wed Oct 22 13:09:56 GMT 2025