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sys/netinet/ip_output.c
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1 /* 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 34 * $FreeBSD: releng/5.2/sys/netinet/ip_output.c 124284 2004-01-09 12:18:17Z andre $ 35 */ 36 37 #include "opt_ipfw.h" 38 #include "opt_ipdn.h" 39 #include "opt_ipdivert.h" 40 #include "opt_ipfilter.h" 41 #include "opt_ipsec.h" 42 #include "opt_mac.h" 43 #include "opt_pfil_hooks.h" 44 #include "opt_random_ip_id.h" 45 #include "opt_mbuf_stress_test.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/mac.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/protosw.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/sysctl.h> 57 58 #include <net/if.h> 59 #include <net/route.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/ip.h> 64 #include <netinet/in_pcb.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip_var.h> 67 68 #ifdef PFIL_HOOKS 69 #include <net/pfil.h> 70 #endif 71 72 #include <machine/in_cksum.h> 73 74 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 75 76 #ifdef IPSEC 77 #include <netinet6/ipsec.h> 78 #include <netkey/key.h> 79 #ifdef IPSEC_DEBUG 80 #include <netkey/key_debug.h> 81 #else 82 #define KEYDEBUG(lev,arg) 83 #endif 84 #endif /*IPSEC*/ 85 86 #ifdef FAST_IPSEC 87 #include <netipsec/ipsec.h> 88 #include <netipsec/xform.h> 89 #include <netipsec/key.h> 90 #endif /*FAST_IPSEC*/ 91 92 #include <netinet/ip_fw.h> 93 #include <netinet/ip_dummynet.h> 94 95 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 96 x, (ntohl(a.s_addr)>>24)&0xFF,\ 97 (ntohl(a.s_addr)>>16)&0xFF,\ 98 (ntohl(a.s_addr)>>8)&0xFF,\ 99 (ntohl(a.s_addr))&0xFF, y); 100 101 u_short ip_id; 102 103 #ifdef MBUF_STRESS_TEST 104 int mbuf_frag_size = 0; 105 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 106 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 107 #endif 108 109 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 110 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 111 static void ip_mloopback 112 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 113 static int ip_getmoptions 114 (struct sockopt *, struct ip_moptions *); 115 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 116 static int ip_setmoptions 117 (struct sockopt *, struct ip_moptions **); 118 119 int ip_optcopy(struct ip *, struct ip *); 120 121 122 extern struct protosw inetsw[]; 123 124 /* 125 * IP output. The packet in mbuf chain m contains a skeletal IP 126 * header (with len, off, ttl, proto, tos, src, dst). 127 * The mbuf chain containing the packet will be freed. 128 * The mbuf opt, if present, will not be freed. 129 * In the IP forwarding case, the packet will arrive with options already 130 * inserted, so must have a NULL opt pointer. 131 */ 132 int 133 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 134 int flags, struct ip_moptions *imo, struct inpcb *inp) 135 { 136 struct ip *ip; 137 struct ifnet *ifp = NULL; /* keep compiler happy */ 138 struct mbuf *m; 139 int hlen = sizeof (struct ip); 140 int len, off, error = 0; 141 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 142 struct in_ifaddr *ia = NULL; 143 int isbroadcast, sw_csum; 144 struct in_addr pkt_dst; 145 struct route iproute; 146 #ifdef IPSEC 147 struct socket *so; 148 struct secpolicy *sp = NULL; 149 #endif 150 #ifdef FAST_IPSEC 151 struct m_tag *mtag; 152 struct secpolicy *sp = NULL; 153 struct tdb_ident *tdbi; 154 int s; 155 #endif /* FAST_IPSEC */ 156 struct ip_fw_args args; 157 int src_was_INADDR_ANY = 0; /* as the name says... */ 158 159 args.eh = NULL; 160 args.rule = NULL; 161 args.next_hop = NULL; 162 args.divert_rule = 0; /* divert cookie */ 163 164 /* Grab info from MT_TAG mbufs prepended to the chain. */ 165 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) { 166 switch(m0->_m_tag_id) { 167 default: 168 printf("ip_output: unrecognised MT_TAG tag %d\n", 169 m0->_m_tag_id); 170 break; 171 172 case PACKET_TAG_DUMMYNET: 173 /* 174 * the packet was already tagged, so part of the 175 * processing was already done, and we need to go down. 176 * Get parameters from the header. 177 */ 178 args.rule = ((struct dn_pkt *)m0)->rule; 179 opt = NULL ; 180 ro = & ( ((struct dn_pkt *)m0)->ro ) ; 181 imo = NULL ; 182 dst = ((struct dn_pkt *)m0)->dn_dst ; 183 ifp = ((struct dn_pkt *)m0)->ifp ; 184 flags = ((struct dn_pkt *)m0)->flags ; 185 break; 186 187 case PACKET_TAG_DIVERT: 188 args.divert_rule = (intptr_t)m0->m_data & 0xffff; 189 break; 190 191 case PACKET_TAG_IPFORWARD: 192 args.next_hop = (struct sockaddr_in *)m0->m_data; 193 break; 194 } 195 } 196 m = m0; 197 198 #ifdef IPSEC 199 so = ipsec_getsocket(m); 200 (void)ipsec_setsocket(m, NULL); 201 #endif /*IPSEC*/ 202 203 M_ASSERTPKTHDR(m); 204 205 if (ro == NULL) { 206 ro = &iproute; 207 bzero(ro, sizeof (*ro)); 208 } 209 210 if (inp != NULL) 211 INP_LOCK_ASSERT(inp); 212 213 if (args.rule != NULL) { /* dummynet already saw us */ 214 ip = mtod(m, struct ip *); 215 hlen = ip->ip_hl << 2 ; 216 if (ro->ro_rt) 217 ia = ifatoia(ro->ro_rt->rt_ifa); 218 goto sendit; 219 } 220 221 if (opt) { 222 len = 0; 223 m = ip_insertoptions(m, opt, &len); 224 if (len != 0) 225 hlen = len; 226 } 227 ip = mtod(m, struct ip *); 228 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 229 230 /* 231 * Fill in IP header. If we are not allowing fragmentation, 232 * then the ip_id field is meaningless, but we don't set it 233 * to zero. Doing so causes various problems when devices along 234 * the path (routers, load balancers, firewalls, etc.) illegally 235 * disable DF on our packet. Note that a 16-bit counter 236 * will wrap around in less than 10 seconds at 100 Mbit/s on a 237 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 238 * for Counting NATted Hosts", Proc. IMW'02, available at 239 * <http://www.research.att.com/~smb/papers/fnat.pdf>. 240 */ 241 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 242 ip->ip_v = IPVERSION; 243 ip->ip_hl = hlen >> 2; 244 #ifdef RANDOM_IP_ID 245 ip->ip_id = ip_randomid(); 246 #else 247 ip->ip_id = htons(ip_id++); 248 #endif 249 ipstat.ips_localout++; 250 } else { 251 hlen = ip->ip_hl << 2; 252 } 253 254 dst = (struct sockaddr_in *)&ro->ro_dst; 255 /* 256 * If there is a cached route, 257 * check that it is to the same destination 258 * and is still up. If not, free it and try again. 259 * The address family should also be checked in case of sharing the 260 * cache with IPv6. 261 */ 262 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 263 dst->sin_family != AF_INET || 264 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 265 RTFREE(ro->ro_rt); 266 ro->ro_rt = (struct rtentry *)0; 267 } 268 if (ro->ro_rt == 0) { 269 bzero(dst, sizeof(*dst)); 270 dst->sin_family = AF_INET; 271 dst->sin_len = sizeof(*dst); 272 dst->sin_addr = pkt_dst; 273 } 274 /* 275 * If routing to interface only, 276 * short circuit routing lookup. 277 */ 278 if (flags & IP_ROUTETOIF) { 279 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 280 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 281 ipstat.ips_noroute++; 282 error = ENETUNREACH; 283 goto bad; 284 } 285 ifp = ia->ia_ifp; 286 ip->ip_ttl = 1; 287 isbroadcast = in_broadcast(dst->sin_addr, ifp); 288 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 289 imo != NULL && imo->imo_multicast_ifp != NULL) { 290 /* 291 * Bypass the normal routing lookup for multicast 292 * packets if the interface is specified. 293 */ 294 ifp = imo->imo_multicast_ifp; 295 IFP_TO_IA(ifp, ia); 296 isbroadcast = 0; /* fool gcc */ 297 } else { 298 /* 299 * We want to do any cloning requested by the link layer, 300 * as this is probably required in all cases for correct 301 * operation (as it is for ARP). 302 */ 303 if (ro->ro_rt == 0) 304 rtalloc(ro); 305 if (ro->ro_rt == 0) { 306 ipstat.ips_noroute++; 307 error = EHOSTUNREACH; 308 goto bad; 309 } 310 ia = ifatoia(ro->ro_rt->rt_ifa); 311 ifp = ro->ro_rt->rt_ifp; 312 ro->ro_rt->rt_rmx.rmx_pksent++; 313 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 314 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 315 if (ro->ro_rt->rt_flags & RTF_HOST) 316 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 317 else 318 isbroadcast = in_broadcast(dst->sin_addr, ifp); 319 } 320 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 321 struct in_multi *inm; 322 323 m->m_flags |= M_MCAST; 324 /* 325 * IP destination address is multicast. Make sure "dst" 326 * still points to the address in "ro". (It may have been 327 * changed to point to a gateway address, above.) 328 */ 329 dst = (struct sockaddr_in *)&ro->ro_dst; 330 /* 331 * See if the caller provided any multicast options 332 */ 333 if (imo != NULL) { 334 ip->ip_ttl = imo->imo_multicast_ttl; 335 if (imo->imo_multicast_vif != -1) 336 ip->ip_src.s_addr = 337 ip_mcast_src ? 338 ip_mcast_src(imo->imo_multicast_vif) : 339 INADDR_ANY; 340 } else 341 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 342 /* 343 * Confirm that the outgoing interface supports multicast. 344 */ 345 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 346 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 347 ipstat.ips_noroute++; 348 error = ENETUNREACH; 349 goto bad; 350 } 351 } 352 /* 353 * If source address not specified yet, use address 354 * of outgoing interface. 355 */ 356 if (ip->ip_src.s_addr == INADDR_ANY) { 357 /* Interface may have no addresses. */ 358 if (ia != NULL) 359 ip->ip_src = IA_SIN(ia)->sin_addr; 360 } 361 362 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 363 /* 364 * XXX 365 * delayed checksums are not currently 366 * compatible with IP multicast routing 367 */ 368 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 369 in_delayed_cksum(m); 370 m->m_pkthdr.csum_flags &= 371 ~CSUM_DELAY_DATA; 372 } 373 } 374 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 375 if (inm != NULL && 376 (imo == NULL || imo->imo_multicast_loop)) { 377 /* 378 * If we belong to the destination multicast group 379 * on the outgoing interface, and the caller did not 380 * forbid loopback, loop back a copy. 381 */ 382 ip_mloopback(ifp, m, dst, hlen); 383 } 384 else { 385 /* 386 * If we are acting as a multicast router, perform 387 * multicast forwarding as if the packet had just 388 * arrived on the interface to which we are about 389 * to send. The multicast forwarding function 390 * recursively calls this function, using the 391 * IP_FORWARDING flag to prevent infinite recursion. 392 * 393 * Multicasts that are looped back by ip_mloopback(), 394 * above, will be forwarded by the ip_input() routine, 395 * if necessary. 396 */ 397 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 398 /* 399 * If rsvp daemon is not running, do not 400 * set ip_moptions. This ensures that the packet 401 * is multicast and not just sent down one link 402 * as prescribed by rsvpd. 403 */ 404 if (!rsvp_on) 405 imo = NULL; 406 if (ip_mforward && 407 ip_mforward(ip, ifp, m, imo) != 0) { 408 m_freem(m); 409 goto done; 410 } 411 } 412 } 413 414 /* 415 * Multicasts with a time-to-live of zero may be looped- 416 * back, above, but must not be transmitted on a network. 417 * Also, multicasts addressed to the loopback interface 418 * are not sent -- the above call to ip_mloopback() will 419 * loop back a copy if this host actually belongs to the 420 * destination group on the loopback interface. 421 */ 422 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 423 m_freem(m); 424 goto done; 425 } 426 427 goto sendit; 428 } 429 #ifndef notdef 430 /* 431 * If the source address is not specified yet, use the address 432 * of the outoing interface. In case, keep note we did that, so 433 * if the the firewall changes the next-hop causing the output 434 * interface to change, we can fix that. 435 */ 436 if (ip->ip_src.s_addr == INADDR_ANY) { 437 /* Interface may have no addresses. */ 438 if (ia != NULL) { 439 ip->ip_src = IA_SIN(ia)->sin_addr; 440 src_was_INADDR_ANY = 1; 441 } 442 } 443 #endif /* notdef */ 444 /* 445 * Verify that we have any chance at all of being able to queue 446 * the packet or packet fragments 447 */ 448 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 449 ifp->if_snd.ifq_maxlen) { 450 error = ENOBUFS; 451 ipstat.ips_odropped++; 452 goto bad; 453 } 454 455 /* 456 * Look for broadcast address and 457 * verify user is allowed to send 458 * such a packet. 459 */ 460 if (isbroadcast) { 461 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 462 error = EADDRNOTAVAIL; 463 goto bad; 464 } 465 if ((flags & IP_ALLOWBROADCAST) == 0) { 466 error = EACCES; 467 goto bad; 468 } 469 /* don't allow broadcast messages to be fragmented */ 470 if (ip->ip_len > ifp->if_mtu) { 471 error = EMSGSIZE; 472 goto bad; 473 } 474 if (flags & IP_SENDONES) 475 ip->ip_dst.s_addr = INADDR_BROADCAST; 476 m->m_flags |= M_BCAST; 477 } else { 478 m->m_flags &= ~M_BCAST; 479 } 480 481 sendit: 482 #ifdef IPSEC 483 /* get SP for this packet */ 484 if (so == NULL) 485 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 486 flags, &error); 487 else 488 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 489 490 if (sp == NULL) { 491 ipsecstat.out_inval++; 492 goto bad; 493 } 494 495 error = 0; 496 497 /* check policy */ 498 switch (sp->policy) { 499 case IPSEC_POLICY_DISCARD: 500 /* 501 * This packet is just discarded. 502 */ 503 ipsecstat.out_polvio++; 504 goto bad; 505 506 case IPSEC_POLICY_BYPASS: 507 case IPSEC_POLICY_NONE: 508 /* no need to do IPsec. */ 509 goto skip_ipsec; 510 511 case IPSEC_POLICY_IPSEC: 512 if (sp->req == NULL) { 513 /* acquire a policy */ 514 error = key_spdacquire(sp); 515 goto bad; 516 } 517 break; 518 519 case IPSEC_POLICY_ENTRUST: 520 default: 521 printf("ip_output: Invalid policy found. %d\n", sp->policy); 522 } 523 { 524 struct ipsec_output_state state; 525 bzero(&state, sizeof(state)); 526 state.m = m; 527 if (flags & IP_ROUTETOIF) { 528 state.ro = &iproute; 529 bzero(&iproute, sizeof(iproute)); 530 } else 531 state.ro = ro; 532 state.dst = (struct sockaddr *)dst; 533 534 ip->ip_sum = 0; 535 536 /* 537 * XXX 538 * delayed checksums are not currently compatible with IPsec 539 */ 540 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 541 in_delayed_cksum(m); 542 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 543 } 544 545 ip->ip_len = htons(ip->ip_len); 546 ip->ip_off = htons(ip->ip_off); 547 548 error = ipsec4_output(&state, sp, flags); 549 550 m = state.m; 551 if (flags & IP_ROUTETOIF) { 552 /* 553 * if we have tunnel mode SA, we may need to ignore 554 * IP_ROUTETOIF. 555 */ 556 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 557 flags &= ~IP_ROUTETOIF; 558 ro = state.ro; 559 } 560 } else 561 ro = state.ro; 562 dst = (struct sockaddr_in *)state.dst; 563 if (error) { 564 /* mbuf is already reclaimed in ipsec4_output. */ 565 m0 = NULL; 566 switch (error) { 567 case EHOSTUNREACH: 568 case ENETUNREACH: 569 case EMSGSIZE: 570 case ENOBUFS: 571 case ENOMEM: 572 break; 573 default: 574 printf("ip4_output (ipsec): error code %d\n", error); 575 /*fall through*/ 576 case ENOENT: 577 /* don't show these error codes to the user */ 578 error = 0; 579 break; 580 } 581 goto bad; 582 } 583 } 584 585 /* be sure to update variables that are affected by ipsec4_output() */ 586 ip = mtod(m, struct ip *); 587 hlen = ip->ip_hl << 2; 588 if (ro->ro_rt == NULL) { 589 if ((flags & IP_ROUTETOIF) == 0) { 590 printf("ip_output: " 591 "can't update route after IPsec processing\n"); 592 error = EHOSTUNREACH; /*XXX*/ 593 goto bad; 594 } 595 } else { 596 ia = ifatoia(ro->ro_rt->rt_ifa); 597 ifp = ro->ro_rt->rt_ifp; 598 } 599 600 /* make it flipped, again. */ 601 ip->ip_len = ntohs(ip->ip_len); 602 ip->ip_off = ntohs(ip->ip_off); 603 skip_ipsec: 604 #endif /*IPSEC*/ 605 #ifdef FAST_IPSEC 606 /* 607 * Check the security policy (SP) for the packet and, if 608 * required, do IPsec-related processing. There are two 609 * cases here; the first time a packet is sent through 610 * it will be untagged and handled by ipsec4_checkpolicy. 611 * If the packet is resubmitted to ip_output (e.g. after 612 * AH, ESP, etc. processing), there will be a tag to bypass 613 * the lookup and related policy checking. 614 */ 615 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 616 s = splnet(); 617 if (mtag != NULL) { 618 tdbi = (struct tdb_ident *)(mtag + 1); 619 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 620 if (sp == NULL) 621 error = -EINVAL; /* force silent drop */ 622 m_tag_delete(m, mtag); 623 } else { 624 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 625 &error, inp); 626 } 627 /* 628 * There are four return cases: 629 * sp != NULL apply IPsec policy 630 * sp == NULL, error == 0 no IPsec handling needed 631 * sp == NULL, error == -EINVAL discard packet w/o error 632 * sp == NULL, error != 0 discard packet, report error 633 */ 634 if (sp != NULL) { 635 /* Loop detection, check if ipsec processing already done */ 636 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 637 for (mtag = m_tag_first(m); mtag != NULL; 638 mtag = m_tag_next(m, mtag)) { 639 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 640 continue; 641 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 642 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 643 continue; 644 /* 645 * Check if policy has an SA associated with it. 646 * This can happen when an SP has yet to acquire 647 * an SA; e.g. on first reference. If it occurs, 648 * then we let ipsec4_process_packet do its thing. 649 */ 650 if (sp->req->sav == NULL) 651 break; 652 tdbi = (struct tdb_ident *)(mtag + 1); 653 if (tdbi->spi == sp->req->sav->spi && 654 tdbi->proto == sp->req->sav->sah->saidx.proto && 655 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 656 sizeof (union sockaddr_union)) == 0) { 657 /* 658 * No IPsec processing is needed, free 659 * reference to SP. 660 * 661 * NB: null pointer to avoid free at 662 * done: below. 663 */ 664 KEY_FREESP(&sp), sp = NULL; 665 splx(s); 666 goto spd_done; 667 } 668 } 669 670 /* 671 * Do delayed checksums now because we send before 672 * this is done in the normal processing path. 673 */ 674 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 675 in_delayed_cksum(m); 676 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 677 } 678 679 ip->ip_len = htons(ip->ip_len); 680 ip->ip_off = htons(ip->ip_off); 681 682 /* NB: callee frees mbuf */ 683 error = ipsec4_process_packet(m, sp->req, flags, 0); 684 /* 685 * Preserve KAME behaviour: ENOENT can be returned 686 * when an SA acquire is in progress. Don't propagate 687 * this to user-level; it confuses applications. 688 * 689 * XXX this will go away when the SADB is redone. 690 */ 691 if (error == ENOENT) 692 error = 0; 693 splx(s); 694 goto done; 695 } else { 696 splx(s); 697 698 if (error != 0) { 699 /* 700 * Hack: -EINVAL is used to signal that a packet 701 * should be silently discarded. This is typically 702 * because we asked key management for an SA and 703 * it was delayed (e.g. kicked up to IKE). 704 */ 705 if (error == -EINVAL) 706 error = 0; 707 goto bad; 708 } else { 709 /* No IPsec processing for this packet. */ 710 } 711 #ifdef notyet 712 /* 713 * If deferred crypto processing is needed, check that 714 * the interface supports it. 715 */ 716 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 717 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 718 /* notify IPsec to do its own crypto */ 719 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 720 error = EHOSTUNREACH; 721 goto bad; 722 } 723 #endif 724 } 725 spd_done: 726 #endif /* FAST_IPSEC */ 727 728 /* 729 * IpHack's section. 730 * - Xlate: translate packet's addr/port (NAT). 731 * - Firewall: deny/allow/etc. 732 * - Wrap: fake packet's addr/port <unimpl.> 733 * - Encapsulate: put it in another IP and send out. <unimp.> 734 */ 735 #ifdef PFIL_HOOKS 736 /* 737 * Run through list of hooks for output packets. 738 */ 739 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 740 if (error != 0 || m == NULL) 741 goto done; 742 ip = mtod(m, struct ip *); 743 #endif /* PFIL_HOOKS */ 744 745 /* 746 * Check with the firewall... 747 * but not if we are already being fwd'd from a firewall. 748 */ 749 if (fw_enable && IPFW_LOADED && !args.next_hop) { 750 struct sockaddr_in *old = dst; 751 752 args.m = m; 753 args.next_hop = dst; 754 args.oif = ifp; 755 off = ip_fw_chk_ptr(&args); 756 m = args.m; 757 dst = args.next_hop; 758 759 /* 760 * On return we must do the following: 761 * m == NULL -> drop the pkt (old interface, deprecated) 762 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 763 * 1<=off<= 0xffff -> DIVERT 764 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 765 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 766 * dst != old -> IPFIREWALL_FORWARD 767 * off==0, dst==old -> accept 768 * If some of the above modules are not compiled in, then 769 * we should't have to check the corresponding condition 770 * (because the ipfw control socket should not accept 771 * unsupported rules), but better play safe and drop 772 * packets in case of doubt. 773 */ 774 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 775 if (m) 776 m_freem(m); 777 error = EACCES; 778 goto done; 779 } 780 ip = mtod(m, struct ip *); 781 if (off == 0 && dst == old) /* common case */ 782 goto pass; 783 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { 784 /* 785 * pass the pkt to dummynet. Need to include 786 * pipe number, m, ifp, ro, dst because these are 787 * not recomputed in the next pass. 788 * All other parameters have been already used and 789 * so they are not needed anymore. 790 * XXX note: if the ifp or ro entry are deleted 791 * while a pkt is in dummynet, we are in trouble! 792 */ 793 args.ro = ro; 794 args.dst = dst; 795 args.flags = flags; 796 797 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 798 &args); 799 goto done; 800 } 801 #ifdef IPDIVERT 802 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { 803 struct mbuf *clone = NULL; 804 805 /* Clone packet if we're doing a 'tee' */ 806 if ((off & IP_FW_PORT_TEE_FLAG) != 0) 807 clone = m_dup(m, M_DONTWAIT); 808 809 /* 810 * XXX 811 * delayed checksums are not currently compatible 812 * with divert sockets. 813 */ 814 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 815 in_delayed_cksum(m); 816 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 817 } 818 819 /* Restore packet header fields to original values */ 820 ip->ip_len = htons(ip->ip_len); 821 ip->ip_off = htons(ip->ip_off); 822 823 /* Deliver packet to divert input routine */ 824 divert_packet(m, 0, off & 0xffff, args.divert_rule); 825 826 /* If 'tee', continue with original packet */ 827 if (clone != NULL) { 828 m = clone; 829 ip = mtod(m, struct ip *); 830 goto pass; 831 } 832 goto done; 833 } 834 #endif 835 836 /* IPFIREWALL_FORWARD */ 837 /* 838 * Check dst to make sure it is directly reachable on the 839 * interface we previously thought it was. 840 * If it isn't (which may be likely in some situations) we have 841 * to re-route it (ie, find a route for the next-hop and the 842 * associated interface) and set them here. This is nested 843 * forwarding which in most cases is undesirable, except where 844 * such control is nigh impossible. So we do it here. 845 * And I'm babbling. 846 */ 847 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 848 #if 0 849 /* 850 * XXX To improve readability, this block should be 851 * changed into a function call as below: 852 */ 853 error = ip_ipforward(&m, &dst, &ifp); 854 if (error) 855 goto bad; 856 if (m == NULL) /* ip_input consumed the mbuf */ 857 goto done; 858 #else 859 struct in_ifaddr *ia; 860 861 /* 862 * XXX sro_fwd below is static, and a pointer 863 * to it gets passed to routines downstream. 864 * This could have surprisingly bad results in 865 * practice, because its content is overwritten 866 * by subsequent packets. 867 */ 868 /* There must be a better way to do this next line... */ 869 static struct route sro_fwd; 870 struct route *ro_fwd = &sro_fwd; 871 872 #if 0 873 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 874 dst->sin_addr, "\n"); 875 #endif 876 877 /* 878 * We need to figure out if we have been forwarded 879 * to a local socket. If so, then we should somehow 880 * "loop back" to ip_input, and get directed to the 881 * PCB as if we had received this packet. This is 882 * because it may be dificult to identify the packets 883 * you want to forward until they are being output 884 * and have selected an interface. (e.g. locally 885 * initiated packets) If we used the loopback inteface, 886 * we would not be able to control what happens 887 * as the packet runs through ip_input() as 888 * it is done through an ISR. 889 */ 890 LIST_FOREACH(ia, 891 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 892 /* 893 * If the addr to forward to is one 894 * of ours, we pretend to 895 * be the destination for this packet. 896 */ 897 if (IA_SIN(ia)->sin_addr.s_addr == 898 dst->sin_addr.s_addr) 899 break; 900 } 901 if (ia) { /* tell ip_input "dont filter" */ 902 struct m_hdr tag; 903 904 tag.mh_type = MT_TAG; 905 tag.mh_flags = PACKET_TAG_IPFORWARD; 906 tag.mh_data = (caddr_t)args.next_hop; 907 tag.mh_next = m; 908 tag.mh_nextpkt = NULL; 909 910 if (m->m_pkthdr.rcvif == NULL) 911 m->m_pkthdr.rcvif = ifunit("lo0"); 912 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 913 m->m_pkthdr.csum_flags |= 914 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 915 m0->m_pkthdr.csum_data = 0xffff; 916 } 917 m->m_pkthdr.csum_flags |= 918 CSUM_IP_CHECKED | CSUM_IP_VALID; 919 ip->ip_len = htons(ip->ip_len); 920 ip->ip_off = htons(ip->ip_off); 921 ip_input((struct mbuf *)&tag); 922 goto done; 923 } 924 /* 925 * Some of the logic for this was 926 * nicked from above. 927 */ 928 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 929 930 ro_fwd->ro_rt = 0; 931 rtalloc_ign(ro_fwd, RTF_CLONING); 932 933 if (ro_fwd->ro_rt == 0) { 934 ipstat.ips_noroute++; 935 error = EHOSTUNREACH; 936 goto bad; 937 } 938 939 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 940 ifp = ro_fwd->ro_rt->rt_ifp; 941 ro_fwd->ro_rt->rt_rmx.rmx_pksent++; 942 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 943 dst = (struct sockaddr_in *) 944 ro_fwd->ro_rt->rt_gateway; 945 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 946 isbroadcast = 947 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 948 else 949 isbroadcast = in_broadcast(dst->sin_addr, ifp); 950 if (ro->ro_rt) 951 RTFREE(ro->ro_rt); 952 ro->ro_rt = ro_fwd->ro_rt; 953 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 954 955 #endif /* ... block to be put into a function */ 956 /* 957 * If we added a default src ip earlier, 958 * which would have been gotten from the-then 959 * interface, do it again, from the new one. 960 */ 961 if (src_was_INADDR_ANY) 962 ip->ip_src = IA_SIN(ia)->sin_addr; 963 goto pass ; 964 } 965 966 /* 967 * if we get here, none of the above matches, and 968 * we have to drop the pkt 969 */ 970 m_freem(m); 971 error = EACCES; /* not sure this is the right error msg */ 972 goto done; 973 } 974 975 pass: 976 /* 127/8 must not appear on wire - RFC1122. */ 977 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 978 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 979 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 980 ipstat.ips_badaddr++; 981 error = EADDRNOTAVAIL; 982 goto bad; 983 } 984 } 985 986 m->m_pkthdr.csum_flags |= CSUM_IP; 987 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 988 if (sw_csum & CSUM_DELAY_DATA) { 989 in_delayed_cksum(m); 990 sw_csum &= ~CSUM_DELAY_DATA; 991 } 992 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 993 994 /* 995 * If small enough for interface, or the interface will take 996 * care of the fragmentation for us, can just send directly. 997 */ 998 if (ip->ip_len <= ifp->if_mtu || (ifp->if_hwassist & CSUM_FRAGMENT && 999 ((ip->ip_off & IP_DF) == 0))) { 1000 ip->ip_len = htons(ip->ip_len); 1001 ip->ip_off = htons(ip->ip_off); 1002 ip->ip_sum = 0; 1003 if (sw_csum & CSUM_DELAY_IP) 1004 ip->ip_sum = in_cksum(m, hlen); 1005 1006 /* Record statistics for this interface address. */ 1007 if (!(flags & IP_FORWARDING) && ia) { 1008 ia->ia_ifa.if_opackets++; 1009 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1010 } 1011 1012 #ifdef IPSEC 1013 /* clean ipsec history once it goes out of the node */ 1014 ipsec_delaux(m); 1015 #endif 1016 1017 #ifdef MBUF_STRESS_TEST 1018 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 1019 m = m_fragment(m, M_DONTWAIT, mbuf_frag_size); 1020 #endif 1021 error = (*ifp->if_output)(ifp, m, 1022 (struct sockaddr *)dst, ro->ro_rt); 1023 goto done; 1024 } 1025 1026 if (ip->ip_off & IP_DF) { 1027 error = EMSGSIZE; 1028 /* 1029 * This case can happen if the user changed the MTU 1030 * of an interface after enabling IP on it. Because 1031 * most netifs don't keep track of routes pointing to 1032 * them, there is no way for one to update all its 1033 * routes when the MTU is changed. 1034 */ 1035 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1036 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1037 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1038 } 1039 ipstat.ips_cantfrag++; 1040 goto bad; 1041 } 1042 1043 /* 1044 * Too large for interface; fragment if possible. If successful, 1045 * on return, m will point to a list of packets to be sent. 1046 */ 1047 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1048 if (error) 1049 goto bad; 1050 for (; m; m = m0) { 1051 m0 = m->m_nextpkt; 1052 m->m_nextpkt = 0; 1053 #ifdef IPSEC 1054 /* clean ipsec history once it goes out of the node */ 1055 ipsec_delaux(m); 1056 #endif 1057 if (error == 0) { 1058 /* Record statistics for this interface address. */ 1059 if (ia != NULL) { 1060 ia->ia_ifa.if_opackets++; 1061 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1062 } 1063 1064 error = (*ifp->if_output)(ifp, m, 1065 (struct sockaddr *)dst, ro->ro_rt); 1066 } else 1067 m_freem(m); 1068 } 1069 1070 if (error == 0) 1071 ipstat.ips_fragmented++; 1072 1073 done: 1074 if (ro == &iproute && ro->ro_rt) { 1075 RTFREE(ro->ro_rt); 1076 ro->ro_rt = NULL; 1077 } 1078 #ifdef IPSEC 1079 if (sp != NULL) { 1080 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1081 printf("DP ip_output call free SP:%p\n", sp)); 1082 key_freesp(sp); 1083 } 1084 #endif 1085 #ifdef FAST_IPSEC 1086 if (sp != NULL) 1087 KEY_FREESP(&sp); 1088 #endif 1089 return (error); 1090 bad: 1091 m_freem(m); 1092 goto done; 1093 } 1094 1095 /* 1096 * Create a chain of fragments which fit the given mtu. m_frag points to the 1097 * mbuf to be fragmented; on return it points to the chain with the fragments. 1098 * Return 0 if no error. If error, m_frag may contain a partially built 1099 * chain of fragments that should be freed by the caller. 1100 * 1101 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1102 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1103 */ 1104 int 1105 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1106 u_long if_hwassist_flags, int sw_csum) 1107 { 1108 int error = 0; 1109 int hlen = ip->ip_hl << 2; 1110 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1111 int off; 1112 struct mbuf *m0 = *m_frag; /* the original packet */ 1113 int firstlen; 1114 struct mbuf **mnext; 1115 int nfrags; 1116 1117 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1118 ipstat.ips_cantfrag++; 1119 return EMSGSIZE; 1120 } 1121 1122 /* 1123 * Must be able to put at least 8 bytes per fragment. 1124 */ 1125 if (len < 8) 1126 return EMSGSIZE; 1127 1128 /* 1129 * If the interface will not calculate checksums on 1130 * fragmented packets, then do it here. 1131 */ 1132 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && 1133 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { 1134 in_delayed_cksum(m0); 1135 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1136 } 1137 1138 if (len > PAGE_SIZE) { 1139 /* 1140 * Fragment large datagrams such that each segment 1141 * contains a multiple of PAGE_SIZE amount of data, 1142 * plus headers. This enables a receiver to perform 1143 * page-flipping zero-copy optimizations. 1144 * 1145 * XXX When does this help given that sender and receiver 1146 * could have different page sizes, and also mtu could 1147 * be less than the receiver's page size ? 1148 */ 1149 int newlen; 1150 struct mbuf *m; 1151 1152 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1153 off += m->m_len; 1154 1155 /* 1156 * firstlen (off - hlen) must be aligned on an 1157 * 8-byte boundary 1158 */ 1159 if (off < hlen) 1160 goto smart_frag_failure; 1161 off = ((off - hlen) & ~7) + hlen; 1162 newlen = (~PAGE_MASK) & mtu; 1163 if ((newlen + sizeof (struct ip)) > mtu) { 1164 /* we failed, go back the default */ 1165 smart_frag_failure: 1166 newlen = len; 1167 off = hlen + len; 1168 } 1169 len = newlen; 1170 1171 } else { 1172 off = hlen + len; 1173 } 1174 1175 firstlen = off - hlen; 1176 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1177 1178 /* 1179 * Loop through length of segment after first fragment, 1180 * make new header and copy data of each part and link onto chain. 1181 * Here, m0 is the original packet, m is the fragment being created. 1182 * The fragments are linked off the m_nextpkt of the original 1183 * packet, which after processing serves as the first fragment. 1184 */ 1185 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1186 struct ip *mhip; /* ip header on the fragment */ 1187 struct mbuf *m; 1188 int mhlen = sizeof (struct ip); 1189 1190 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1191 if (m == 0) { 1192 error = ENOBUFS; 1193 ipstat.ips_odropped++; 1194 goto done; 1195 } 1196 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1197 /* 1198 * In the first mbuf, leave room for the link header, then 1199 * copy the original IP header including options. The payload 1200 * goes into an additional mbuf chain returned by m_copy(). 1201 */ 1202 m->m_data += max_linkhdr; 1203 mhip = mtod(m, struct ip *); 1204 *mhip = *ip; 1205 if (hlen > sizeof (struct ip)) { 1206 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1207 mhip->ip_v = IPVERSION; 1208 mhip->ip_hl = mhlen >> 2; 1209 } 1210 m->m_len = mhlen; 1211 /* XXX do we need to add ip->ip_off below ? */ 1212 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1213 if (off + len >= ip->ip_len) { /* last fragment */ 1214 len = ip->ip_len - off; 1215 m->m_flags |= M_LASTFRAG; 1216 } else 1217 mhip->ip_off |= IP_MF; 1218 mhip->ip_len = htons((u_short)(len + mhlen)); 1219 m->m_next = m_copy(m0, off, len); 1220 if (m->m_next == 0) { /* copy failed */ 1221 m_free(m); 1222 error = ENOBUFS; /* ??? */ 1223 ipstat.ips_odropped++; 1224 goto done; 1225 } 1226 m->m_pkthdr.len = mhlen + len; 1227 m->m_pkthdr.rcvif = (struct ifnet *)0; 1228 #ifdef MAC 1229 mac_create_fragment(m0, m); 1230 #endif 1231 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1232 mhip->ip_off = htons(mhip->ip_off); 1233 mhip->ip_sum = 0; 1234 if (sw_csum & CSUM_DELAY_IP) 1235 mhip->ip_sum = in_cksum(m, mhlen); 1236 *mnext = m; 1237 mnext = &m->m_nextpkt; 1238 } 1239 ipstat.ips_ofragments += nfrags; 1240 1241 /* set first marker for fragment chain */ 1242 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1243 m0->m_pkthdr.csum_data = nfrags; 1244 1245 /* 1246 * Update first fragment by trimming what's been copied out 1247 * and updating header. 1248 */ 1249 m_adj(m0, hlen + firstlen - ip->ip_len); 1250 m0->m_pkthdr.len = hlen + firstlen; 1251 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1252 ip->ip_off |= IP_MF; 1253 ip->ip_off = htons(ip->ip_off); 1254 ip->ip_sum = 0; 1255 if (sw_csum & CSUM_DELAY_IP) 1256 ip->ip_sum = in_cksum(m0, hlen); 1257 1258 done: 1259 *m_frag = m0; 1260 return error; 1261 } 1262 1263 void 1264 in_delayed_cksum(struct mbuf *m) 1265 { 1266 struct ip *ip; 1267 u_short csum, offset; 1268 1269 ip = mtod(m, struct ip *); 1270 offset = ip->ip_hl << 2 ; 1271 csum = in_cksum_skip(m, ip->ip_len, offset); 1272 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1273 csum = 0xffff; 1274 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1275 1276 if (offset + sizeof(u_short) > m->m_len) { 1277 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1278 m->m_len, offset, ip->ip_p); 1279 /* 1280 * XXX 1281 * this shouldn't happen, but if it does, the 1282 * correct behavior may be to insert the checksum 1283 * in the existing chain instead of rearranging it. 1284 */ 1285 m = m_pullup(m, offset + sizeof(u_short)); 1286 } 1287 *(u_short *)(m->m_data + offset) = csum; 1288 } 1289 1290 /* 1291 * Insert IP options into preformed packet. 1292 * Adjust IP destination as required for IP source routing, 1293 * as indicated by a non-zero in_addr at the start of the options. 1294 * 1295 * XXX This routine assumes that the packet has no options in place. 1296 */ 1297 static struct mbuf * 1298 ip_insertoptions(m, opt, phlen) 1299 register struct mbuf *m; 1300 struct mbuf *opt; 1301 int *phlen; 1302 { 1303 register struct ipoption *p = mtod(opt, struct ipoption *); 1304 struct mbuf *n; 1305 register struct ip *ip = mtod(m, struct ip *); 1306 unsigned optlen; 1307 1308 optlen = opt->m_len - sizeof(p->ipopt_dst); 1309 if (optlen + ip->ip_len > IP_MAXPACKET) { 1310 *phlen = 0; 1311 return (m); /* XXX should fail */ 1312 } 1313 if (p->ipopt_dst.s_addr) 1314 ip->ip_dst = p->ipopt_dst; 1315 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1316 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1317 if (n == 0) { 1318 *phlen = 0; 1319 return (m); 1320 } 1321 n->m_pkthdr.rcvif = (struct ifnet *)0; 1322 #ifdef MAC 1323 mac_create_mbuf_from_mbuf(m, n); 1324 #endif 1325 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1326 m->m_len -= sizeof(struct ip); 1327 m->m_data += sizeof(struct ip); 1328 n->m_next = m; 1329 m = n; 1330 m->m_len = optlen + sizeof(struct ip); 1331 m->m_data += max_linkhdr; 1332 bcopy(ip, mtod(m, void *), sizeof(struct ip)); 1333 } else { 1334 m->m_data -= optlen; 1335 m->m_len += optlen; 1336 m->m_pkthdr.len += optlen; 1337 bcopy(ip, mtod(m, void *), sizeof(struct ip)); 1338 } 1339 ip = mtod(m, struct ip *); 1340 bcopy(p->ipopt_list, ip + 1, optlen); 1341 *phlen = sizeof(struct ip) + optlen; 1342 ip->ip_v = IPVERSION; 1343 ip->ip_hl = *phlen >> 2; 1344 ip->ip_len += optlen; 1345 return (m); 1346 } 1347 1348 /* 1349 * Copy options from ip to jp, 1350 * omitting those not copied during fragmentation. 1351 */ 1352 int 1353 ip_optcopy(ip, jp) 1354 struct ip *ip, *jp; 1355 { 1356 register u_char *cp, *dp; 1357 int opt, optlen, cnt; 1358 1359 cp = (u_char *)(ip + 1); 1360 dp = (u_char *)(jp + 1); 1361 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1362 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1363 opt = cp[0]; 1364 if (opt == IPOPT_EOL) 1365 break; 1366 if (opt == IPOPT_NOP) { 1367 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1368 *dp++ = IPOPT_NOP; 1369 optlen = 1; 1370 continue; 1371 } 1372 1373 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1374 ("ip_optcopy: malformed ipv4 option")); 1375 optlen = cp[IPOPT_OLEN]; 1376 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1377 ("ip_optcopy: malformed ipv4 option")); 1378 1379 /* bogus lengths should have been caught by ip_dooptions */ 1380 if (optlen > cnt) 1381 optlen = cnt; 1382 if (IPOPT_COPIED(opt)) { 1383 bcopy(cp, dp, optlen); 1384 dp += optlen; 1385 } 1386 } 1387 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1388 *dp++ = IPOPT_EOL; 1389 return (optlen); 1390 } 1391 1392 /* 1393 * IP socket option processing. 1394 */ 1395 int 1396 ip_ctloutput(so, sopt) 1397 struct socket *so; 1398 struct sockopt *sopt; 1399 { 1400 struct inpcb *inp = sotoinpcb(so); 1401 int error, optval; 1402 1403 error = optval = 0; 1404 if (sopt->sopt_level != IPPROTO_IP) { 1405 return (EINVAL); 1406 } 1407 1408 switch (sopt->sopt_dir) { 1409 case SOPT_SET: 1410 switch (sopt->sopt_name) { 1411 case IP_OPTIONS: 1412 #ifdef notyet 1413 case IP_RETOPTS: 1414 #endif 1415 { 1416 struct mbuf *m; 1417 if (sopt->sopt_valsize > MLEN) { 1418 error = EMSGSIZE; 1419 break; 1420 } 1421 MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_HEADER); 1422 if (m == 0) { 1423 error = ENOBUFS; 1424 break; 1425 } 1426 m->m_len = sopt->sopt_valsize; 1427 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1428 m->m_len); 1429 1430 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1431 m)); 1432 } 1433 1434 case IP_TOS: 1435 case IP_TTL: 1436 case IP_RECVOPTS: 1437 case IP_RECVRETOPTS: 1438 case IP_RECVDSTADDR: 1439 case IP_RECVTTL: 1440 case IP_RECVIF: 1441 case IP_FAITH: 1442 case IP_ONESBCAST: 1443 error = sooptcopyin(sopt, &optval, sizeof optval, 1444 sizeof optval); 1445 if (error) 1446 break; 1447 1448 switch (sopt->sopt_name) { 1449 case IP_TOS: 1450 inp->inp_ip_tos = optval; 1451 break; 1452 1453 case IP_TTL: 1454 inp->inp_ip_ttl = optval; 1455 break; 1456 #define OPTSET(bit) \ 1457 if (optval) \ 1458 inp->inp_flags |= bit; \ 1459 else \ 1460 inp->inp_flags &= ~bit; 1461 1462 case IP_RECVOPTS: 1463 OPTSET(INP_RECVOPTS); 1464 break; 1465 1466 case IP_RECVRETOPTS: 1467 OPTSET(INP_RECVRETOPTS); 1468 break; 1469 1470 case IP_RECVDSTADDR: 1471 OPTSET(INP_RECVDSTADDR); 1472 break; 1473 1474 case IP_RECVTTL: 1475 OPTSET(INP_RECVTTL); 1476 break; 1477 1478 case IP_RECVIF: 1479 OPTSET(INP_RECVIF); 1480 break; 1481 1482 case IP_FAITH: 1483 OPTSET(INP_FAITH); 1484 break; 1485 1486 case IP_ONESBCAST: 1487 OPTSET(INP_ONESBCAST); 1488 break; 1489 } 1490 break; 1491 #undef OPTSET 1492 1493 case IP_MULTICAST_IF: 1494 case IP_MULTICAST_VIF: 1495 case IP_MULTICAST_TTL: 1496 case IP_MULTICAST_LOOP: 1497 case IP_ADD_MEMBERSHIP: 1498 case IP_DROP_MEMBERSHIP: 1499 error = ip_setmoptions(sopt, &inp->inp_moptions); 1500 break; 1501 1502 case IP_PORTRANGE: 1503 error = sooptcopyin(sopt, &optval, sizeof optval, 1504 sizeof optval); 1505 if (error) 1506 break; 1507 1508 switch (optval) { 1509 case IP_PORTRANGE_DEFAULT: 1510 inp->inp_flags &= ~(INP_LOWPORT); 1511 inp->inp_flags &= ~(INP_HIGHPORT); 1512 break; 1513 1514 case IP_PORTRANGE_HIGH: 1515 inp->inp_flags &= ~(INP_LOWPORT); 1516 inp->inp_flags |= INP_HIGHPORT; 1517 break; 1518 1519 case IP_PORTRANGE_LOW: 1520 inp->inp_flags &= ~(INP_HIGHPORT); 1521 inp->inp_flags |= INP_LOWPORT; 1522 break; 1523 1524 default: 1525 error = EINVAL; 1526 break; 1527 } 1528 break; 1529 1530 #if defined(IPSEC) || defined(FAST_IPSEC) 1531 case IP_IPSEC_POLICY: 1532 { 1533 caddr_t req; 1534 size_t len = 0; 1535 int priv; 1536 struct mbuf *m; 1537 int optname; 1538 1539 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1540 break; 1541 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1542 break; 1543 priv = (sopt->sopt_td != NULL && 1544 suser(sopt->sopt_td) != 0) ? 0 : 1; 1545 req = mtod(m, caddr_t); 1546 len = m->m_len; 1547 optname = sopt->sopt_name; 1548 error = ipsec4_set_policy(inp, optname, req, len, priv); 1549 m_freem(m); 1550 break; 1551 } 1552 #endif /*IPSEC*/ 1553 1554 default: 1555 error = ENOPROTOOPT; 1556 break; 1557 } 1558 break; 1559 1560 case SOPT_GET: 1561 switch (sopt->sopt_name) { 1562 case IP_OPTIONS: 1563 case IP_RETOPTS: 1564 if (inp->inp_options) 1565 error = sooptcopyout(sopt, 1566 mtod(inp->inp_options, 1567 char *), 1568 inp->inp_options->m_len); 1569 else 1570 sopt->sopt_valsize = 0; 1571 break; 1572 1573 case IP_TOS: 1574 case IP_TTL: 1575 case IP_RECVOPTS: 1576 case IP_RECVRETOPTS: 1577 case IP_RECVDSTADDR: 1578 case IP_RECVTTL: 1579 case IP_RECVIF: 1580 case IP_PORTRANGE: 1581 case IP_FAITH: 1582 case IP_ONESBCAST: 1583 switch (sopt->sopt_name) { 1584 1585 case IP_TOS: 1586 optval = inp->inp_ip_tos; 1587 break; 1588 1589 case IP_TTL: 1590 optval = inp->inp_ip_ttl; 1591 break; 1592 1593 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1594 1595 case IP_RECVOPTS: 1596 optval = OPTBIT(INP_RECVOPTS); 1597 break; 1598 1599 case IP_RECVRETOPTS: 1600 optval = OPTBIT(INP_RECVRETOPTS); 1601 break; 1602 1603 case IP_RECVDSTADDR: 1604 optval = OPTBIT(INP_RECVDSTADDR); 1605 break; 1606 1607 case IP_RECVTTL: 1608 optval = OPTBIT(INP_RECVTTL); 1609 break; 1610 1611 case IP_RECVIF: 1612 optval = OPTBIT(INP_RECVIF); 1613 break; 1614 1615 case IP_PORTRANGE: 1616 if (inp->inp_flags & INP_HIGHPORT) 1617 optval = IP_PORTRANGE_HIGH; 1618 else if (inp->inp_flags & INP_LOWPORT) 1619 optval = IP_PORTRANGE_LOW; 1620 else 1621 optval = 0; 1622 break; 1623 1624 case IP_FAITH: 1625 optval = OPTBIT(INP_FAITH); 1626 break; 1627 1628 case IP_ONESBCAST: 1629 optval = OPTBIT(INP_ONESBCAST); 1630 break; 1631 } 1632 error = sooptcopyout(sopt, &optval, sizeof optval); 1633 break; 1634 1635 case IP_MULTICAST_IF: 1636 case IP_MULTICAST_VIF: 1637 case IP_MULTICAST_TTL: 1638 case IP_MULTICAST_LOOP: 1639 case IP_ADD_MEMBERSHIP: 1640 case IP_DROP_MEMBERSHIP: 1641 error = ip_getmoptions(sopt, inp->inp_moptions); 1642 break; 1643 1644 #if defined(IPSEC) || defined(FAST_IPSEC) 1645 case IP_IPSEC_POLICY: 1646 { 1647 struct mbuf *m = NULL; 1648 caddr_t req = NULL; 1649 size_t len = 0; 1650 1651 if (m != 0) { 1652 req = mtod(m, caddr_t); 1653 len = m->m_len; 1654 } 1655 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1656 if (error == 0) 1657 error = soopt_mcopyout(sopt, m); /* XXX */ 1658 if (error == 0) 1659 m_freem(m); 1660 break; 1661 } 1662 #endif /*IPSEC*/ 1663 1664 default: 1665 error = ENOPROTOOPT; 1666 break; 1667 } 1668 break; 1669 } 1670 return (error); 1671 } 1672 1673 /* 1674 * Set up IP options in pcb for insertion in output packets. 1675 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1676 * with destination address if source routed. 1677 */ 1678 static int 1679 ip_pcbopts(optname, pcbopt, m) 1680 int optname; 1681 struct mbuf **pcbopt; 1682 register struct mbuf *m; 1683 { 1684 register int cnt, optlen; 1685 register u_char *cp; 1686 u_char opt; 1687 1688 /* turn off any old options */ 1689 if (*pcbopt) 1690 (void)m_free(*pcbopt); 1691 *pcbopt = 0; 1692 if (m == (struct mbuf *)0 || m->m_len == 0) { 1693 /* 1694 * Only turning off any previous options. 1695 */ 1696 if (m) 1697 (void)m_free(m); 1698 return (0); 1699 } 1700 1701 if (m->m_len % sizeof(int32_t)) 1702 goto bad; 1703 /* 1704 * IP first-hop destination address will be stored before 1705 * actual options; move other options back 1706 * and clear it when none present. 1707 */ 1708 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1709 goto bad; 1710 cnt = m->m_len; 1711 m->m_len += sizeof(struct in_addr); 1712 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1713 bcopy(mtod(m, void *), cp, (unsigned)cnt); 1714 bzero(mtod(m, void *), sizeof(struct in_addr)); 1715 1716 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1717 opt = cp[IPOPT_OPTVAL]; 1718 if (opt == IPOPT_EOL) 1719 break; 1720 if (opt == IPOPT_NOP) 1721 optlen = 1; 1722 else { 1723 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1724 goto bad; 1725 optlen = cp[IPOPT_OLEN]; 1726 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1727 goto bad; 1728 } 1729 switch (opt) { 1730 1731 default: 1732 break; 1733 1734 case IPOPT_LSRR: 1735 case IPOPT_SSRR: 1736 /* 1737 * user process specifies route as: 1738 * ->A->B->C->D 1739 * D must be our final destination (but we can't 1740 * check that since we may not have connected yet). 1741 * A is first hop destination, which doesn't appear in 1742 * actual IP option, but is stored before the options. 1743 */ 1744 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1745 goto bad; 1746 m->m_len -= sizeof(struct in_addr); 1747 cnt -= sizeof(struct in_addr); 1748 optlen -= sizeof(struct in_addr); 1749 cp[IPOPT_OLEN] = optlen; 1750 /* 1751 * Move first hop before start of options. 1752 */ 1753 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1754 sizeof(struct in_addr)); 1755 /* 1756 * Then copy rest of options back 1757 * to close up the deleted entry. 1758 */ 1759 bcopy((&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1760 &cp[IPOPT_OFFSET+1], 1761 (unsigned)cnt + sizeof(struct in_addr)); 1762 break; 1763 } 1764 } 1765 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1766 goto bad; 1767 *pcbopt = m; 1768 return (0); 1769 1770 bad: 1771 (void)m_free(m); 1772 return (EINVAL); 1773 } 1774 1775 /* 1776 * XXX 1777 * The whole multicast option thing needs to be re-thought. 1778 * Several of these options are equally applicable to non-multicast 1779 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1780 * standard option (IP_TTL). 1781 */ 1782 1783 /* 1784 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1785 */ 1786 static struct ifnet * 1787 ip_multicast_if(a, ifindexp) 1788 struct in_addr *a; 1789 int *ifindexp; 1790 { 1791 int ifindex; 1792 struct ifnet *ifp; 1793 1794 if (ifindexp) 1795 *ifindexp = 0; 1796 if (ntohl(a->s_addr) >> 24 == 0) { 1797 ifindex = ntohl(a->s_addr) & 0xffffff; 1798 if (ifindex < 0 || if_index < ifindex) 1799 return NULL; 1800 ifp = ifnet_byindex(ifindex); 1801 if (ifindexp) 1802 *ifindexp = ifindex; 1803 } else { 1804 INADDR_TO_IFP(*a, ifp); 1805 } 1806 return ifp; 1807 } 1808 1809 /* 1810 * Set the IP multicast options in response to user setsockopt(). 1811 */ 1812 static int 1813 ip_setmoptions(sopt, imop) 1814 struct sockopt *sopt; 1815 struct ip_moptions **imop; 1816 { 1817 int error = 0; 1818 int i; 1819 struct in_addr addr; 1820 struct ip_mreq mreq; 1821 struct ifnet *ifp; 1822 struct ip_moptions *imo = *imop; 1823 struct route ro; 1824 struct sockaddr_in *dst; 1825 int ifindex; 1826 int s; 1827 1828 if (imo == NULL) { 1829 /* 1830 * No multicast option buffer attached to the pcb; 1831 * allocate one and initialize to default values. 1832 */ 1833 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1834 M_WAITOK); 1835 1836 if (imo == NULL) 1837 return (ENOBUFS); 1838 *imop = imo; 1839 imo->imo_multicast_ifp = NULL; 1840 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1841 imo->imo_multicast_vif = -1; 1842 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1843 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1844 imo->imo_num_memberships = 0; 1845 } 1846 1847 switch (sopt->sopt_name) { 1848 /* store an index number for the vif you wanna use in the send */ 1849 case IP_MULTICAST_VIF: 1850 if (legal_vif_num == 0) { 1851 error = EOPNOTSUPP; 1852 break; 1853 } 1854 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1855 if (error) 1856 break; 1857 if (!legal_vif_num(i) && (i != -1)) { 1858 error = EINVAL; 1859 break; 1860 } 1861 imo->imo_multicast_vif = i; 1862 break; 1863 1864 case IP_MULTICAST_IF: 1865 /* 1866 * Select the interface for outgoing multicast packets. 1867 */ 1868 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1869 if (error) 1870 break; 1871 /* 1872 * INADDR_ANY is used to remove a previous selection. 1873 * When no interface is selected, a default one is 1874 * chosen every time a multicast packet is sent. 1875 */ 1876 if (addr.s_addr == INADDR_ANY) { 1877 imo->imo_multicast_ifp = NULL; 1878 break; 1879 } 1880 /* 1881 * The selected interface is identified by its local 1882 * IP address. Find the interface and confirm that 1883 * it supports multicasting. 1884 */ 1885 s = splimp(); 1886 ifp = ip_multicast_if(&addr, &ifindex); 1887 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1888 splx(s); 1889 error = EADDRNOTAVAIL; 1890 break; 1891 } 1892 imo->imo_multicast_ifp = ifp; 1893 if (ifindex) 1894 imo->imo_multicast_addr = addr; 1895 else 1896 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1897 splx(s); 1898 break; 1899 1900 case IP_MULTICAST_TTL: 1901 /* 1902 * Set the IP time-to-live for outgoing multicast packets. 1903 * The original multicast API required a char argument, 1904 * which is inconsistent with the rest of the socket API. 1905 * We allow either a char or an int. 1906 */ 1907 if (sopt->sopt_valsize == 1) { 1908 u_char ttl; 1909 error = sooptcopyin(sopt, &ttl, 1, 1); 1910 if (error) 1911 break; 1912 imo->imo_multicast_ttl = ttl; 1913 } else { 1914 u_int ttl; 1915 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1916 sizeof ttl); 1917 if (error) 1918 break; 1919 if (ttl > 255) 1920 error = EINVAL; 1921 else 1922 imo->imo_multicast_ttl = ttl; 1923 } 1924 break; 1925 1926 case IP_MULTICAST_LOOP: 1927 /* 1928 * Set the loopback flag for outgoing multicast packets. 1929 * Must be zero or one. The original multicast API required a 1930 * char argument, which is inconsistent with the rest 1931 * of the socket API. We allow either a char or an int. 1932 */ 1933 if (sopt->sopt_valsize == 1) { 1934 u_char loop; 1935 error = sooptcopyin(sopt, &loop, 1, 1); 1936 if (error) 1937 break; 1938 imo->imo_multicast_loop = !!loop; 1939 } else { 1940 u_int loop; 1941 error = sooptcopyin(sopt, &loop, sizeof loop, 1942 sizeof loop); 1943 if (error) 1944 break; 1945 imo->imo_multicast_loop = !!loop; 1946 } 1947 break; 1948 1949 case IP_ADD_MEMBERSHIP: 1950 /* 1951 * Add a multicast group membership. 1952 * Group must be a valid IP multicast address. 1953 */ 1954 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1955 if (error) 1956 break; 1957 1958 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1959 error = EINVAL; 1960 break; 1961 } 1962 s = splimp(); 1963 /* 1964 * If no interface address was provided, use the interface of 1965 * the route to the given multicast address. 1966 */ 1967 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1968 bzero((caddr_t)&ro, sizeof(ro)); 1969 dst = (struct sockaddr_in *)&ro.ro_dst; 1970 dst->sin_len = sizeof(*dst); 1971 dst->sin_family = AF_INET; 1972 dst->sin_addr = mreq.imr_multiaddr; 1973 rtalloc_ign(&ro, RTF_CLONING); 1974 if (ro.ro_rt == NULL) { 1975 error = EADDRNOTAVAIL; 1976 splx(s); 1977 break; 1978 } 1979 ifp = ro.ro_rt->rt_ifp; 1980 RTFREE(ro.ro_rt); 1981 } 1982 else { 1983 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1984 } 1985 1986 /* 1987 * See if we found an interface, and confirm that it 1988 * supports multicast. 1989 */ 1990 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1991 error = EADDRNOTAVAIL; 1992 splx(s); 1993 break; 1994 } 1995 /* 1996 * See if the membership already exists or if all the 1997 * membership slots are full. 1998 */ 1999 for (i = 0; i < imo->imo_num_memberships; ++i) { 2000 if (imo->imo_membership[i]->inm_ifp == ifp && 2001 imo->imo_membership[i]->inm_addr.s_addr 2002 == mreq.imr_multiaddr.s_addr) 2003 break; 2004 } 2005 if (i < imo->imo_num_memberships) { 2006 error = EADDRINUSE; 2007 splx(s); 2008 break; 2009 } 2010 if (i == IP_MAX_MEMBERSHIPS) { 2011 error = ETOOMANYREFS; 2012 splx(s); 2013 break; 2014 } 2015 /* 2016 * Everything looks good; add a new record to the multicast 2017 * address list for the given interface. 2018 */ 2019 if ((imo->imo_membership[i] = 2020 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 2021 error = ENOBUFS; 2022 splx(s); 2023 break; 2024 } 2025 ++imo->imo_num_memberships; 2026 splx(s); 2027 break; 2028 2029 case IP_DROP_MEMBERSHIP: 2030 /* 2031 * Drop a multicast group membership. 2032 * Group must be a valid IP multicast address. 2033 */ 2034 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2035 if (error) 2036 break; 2037 2038 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2039 error = EINVAL; 2040 break; 2041 } 2042 2043 s = splimp(); 2044 /* 2045 * If an interface address was specified, get a pointer 2046 * to its ifnet structure. 2047 */ 2048 if (mreq.imr_interface.s_addr == INADDR_ANY) 2049 ifp = NULL; 2050 else { 2051 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2052 if (ifp == NULL) { 2053 error = EADDRNOTAVAIL; 2054 splx(s); 2055 break; 2056 } 2057 } 2058 /* 2059 * Find the membership in the membership array. 2060 */ 2061 for (i = 0; i < imo->imo_num_memberships; ++i) { 2062 if ((ifp == NULL || 2063 imo->imo_membership[i]->inm_ifp == ifp) && 2064 imo->imo_membership[i]->inm_addr.s_addr == 2065 mreq.imr_multiaddr.s_addr) 2066 break; 2067 } 2068 if (i == imo->imo_num_memberships) { 2069 error = EADDRNOTAVAIL; 2070 splx(s); 2071 break; 2072 } 2073 /* 2074 * Give up the multicast address record to which the 2075 * membership points. 2076 */ 2077 in_delmulti(imo->imo_membership[i]); 2078 /* 2079 * Remove the gap in the membership array. 2080 */ 2081 for (++i; i < imo->imo_num_memberships; ++i) 2082 imo->imo_membership[i-1] = imo->imo_membership[i]; 2083 --imo->imo_num_memberships; 2084 splx(s); 2085 break; 2086 2087 default: 2088 error = EOPNOTSUPP; 2089 break; 2090 } 2091 2092 /* 2093 * If all options have default values, no need to keep the mbuf. 2094 */ 2095 if (imo->imo_multicast_ifp == NULL && 2096 imo->imo_multicast_vif == -1 && 2097 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2098 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2099 imo->imo_num_memberships == 0) { 2100 free(*imop, M_IPMOPTS); 2101 *imop = NULL; 2102 } 2103 2104 return (error); 2105 } 2106 2107 /* 2108 * Return the IP multicast options in response to user getsockopt(). 2109 */ 2110 static int 2111 ip_getmoptions(sopt, imo) 2112 struct sockopt *sopt; 2113 register struct ip_moptions *imo; 2114 { 2115 struct in_addr addr; 2116 struct in_ifaddr *ia; 2117 int error, optval; 2118 u_char coptval; 2119 2120 error = 0; 2121 switch (sopt->sopt_name) { 2122 case IP_MULTICAST_VIF: 2123 if (imo != NULL) 2124 optval = imo->imo_multicast_vif; 2125 else 2126 optval = -1; 2127 error = sooptcopyout(sopt, &optval, sizeof optval); 2128 break; 2129 2130 case IP_MULTICAST_IF: 2131 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2132 addr.s_addr = INADDR_ANY; 2133 else if (imo->imo_multicast_addr.s_addr) { 2134 /* return the value user has set */ 2135 addr = imo->imo_multicast_addr; 2136 } else { 2137 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2138 addr.s_addr = (ia == NULL) ? INADDR_ANY 2139 : IA_SIN(ia)->sin_addr.s_addr; 2140 } 2141 error = sooptcopyout(sopt, &addr, sizeof addr); 2142 break; 2143 2144 case IP_MULTICAST_TTL: 2145 if (imo == 0) 2146 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2147 else 2148 optval = coptval = imo->imo_multicast_ttl; 2149 if (sopt->sopt_valsize == 1) 2150 error = sooptcopyout(sopt, &coptval, 1); 2151 else 2152 error = sooptcopyout(sopt, &optval, sizeof optval); 2153 break; 2154 2155 case IP_MULTICAST_LOOP: 2156 if (imo == 0) 2157 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2158 else 2159 optval = coptval = imo->imo_multicast_loop; 2160 if (sopt->sopt_valsize == 1) 2161 error = sooptcopyout(sopt, &coptval, 1); 2162 else 2163 error = sooptcopyout(sopt, &optval, sizeof optval); 2164 break; 2165 2166 default: 2167 error = ENOPROTOOPT; 2168 break; 2169 } 2170 return (error); 2171 } 2172 2173 /* 2174 * Discard the IP multicast options. 2175 */ 2176 void 2177 ip_freemoptions(imo) 2178 register struct ip_moptions *imo; 2179 { 2180 register int i; 2181 2182 if (imo != NULL) { 2183 for (i = 0; i < imo->imo_num_memberships; ++i) 2184 in_delmulti(imo->imo_membership[i]); 2185 free(imo, M_IPMOPTS); 2186 } 2187 } 2188 2189 /* 2190 * Routine called from ip_output() to loop back a copy of an IP multicast 2191 * packet to the input queue of a specified interface. Note that this 2192 * calls the output routine of the loopback "driver", but with an interface 2193 * pointer that might NOT be a loopback interface -- evil, but easier than 2194 * replicating that code here. 2195 */ 2196 static void 2197 ip_mloopback(ifp, m, dst, hlen) 2198 struct ifnet *ifp; 2199 register struct mbuf *m; 2200 register struct sockaddr_in *dst; 2201 int hlen; 2202 { 2203 register struct ip *ip; 2204 struct mbuf *copym; 2205 2206 copym = m_copy(m, 0, M_COPYALL); 2207 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2208 copym = m_pullup(copym, hlen); 2209 if (copym != NULL) { 2210 /* 2211 * We don't bother to fragment if the IP length is greater 2212 * than the interface's MTU. Can this possibly matter? 2213 */ 2214 ip = mtod(copym, struct ip *); 2215 ip->ip_len = htons(ip->ip_len); 2216 ip->ip_off = htons(ip->ip_off); 2217 ip->ip_sum = 0; 2218 ip->ip_sum = in_cksum(copym, hlen); 2219 /* 2220 * NB: 2221 * It's not clear whether there are any lingering 2222 * reentrancy problems in other areas which might 2223 * be exposed by using ip_input directly (in 2224 * particular, everything which modifies the packet 2225 * in-place). Yet another option is using the 2226 * protosw directly to deliver the looped back 2227 * packet. For the moment, we'll err on the side 2228 * of safety by using if_simloop(). 2229 */ 2230 #if 1 /* XXX */ 2231 if (dst->sin_family != AF_INET) { 2232 printf("ip_mloopback: bad address family %d\n", 2233 dst->sin_family); 2234 dst->sin_family = AF_INET; 2235 } 2236 #endif 2237 2238 #ifdef notdef 2239 copym->m_pkthdr.rcvif = ifp; 2240 ip_input(copym); 2241 #else 2242 /* if the checksum hasn't been computed, mark it as valid */ 2243 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2244 copym->m_pkthdr.csum_flags |= 2245 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2246 copym->m_pkthdr.csum_data = 0xffff; 2247 } 2248 if_simloop(ifp, copym, dst->sin_family, 0); 2249 #endif 2250 } 2251 }
Cache object: 9ce0c4a0c6c6ea3400e7746d0cfa8873
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