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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 30 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $ 31 * $DragonFly: src/sys/netinet/ip_output.c,v 1.27 2005/03/04 04:38:47 hsu Exp $ 32 */ 33 34 #define _IP_VHL 35 36 #include "opt_ipfw.h" 37 #include "opt_ipdn.h" 38 #include "opt_ipdivert.h" 39 #include "opt_ipfilter.h" 40 #include "opt_ipsec.h" 41 #include "opt_random_ip_id.h" 42 #include "opt_mbuf_stress_test.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/sysctl.h> 54 #include <sys/in_cksum.h> 55 56 #include <net/if.h> 57 #include <net/netisr.h> 58 #include <net/pfil.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 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 69 70 #ifdef IPSEC 71 #include <netinet6/ipsec.h> 72 #include <netproto/key/key.h> 73 #ifdef IPSEC_DEBUG 74 #include <netproto/key/key_debug.h> 75 #else 76 #define KEYDEBUG(lev,arg) 77 #endif 78 #endif /*IPSEC*/ 79 80 #ifdef FAST_IPSEC 81 #include <netproto/ipsec/ipsec.h> 82 #include <netproto/ipsec/xform.h> 83 #include <netproto/ipsec/key.h> 84 #endif /*FAST_IPSEC*/ 85 86 #include <net/ipfw/ip_fw.h> 87 #include <net/dummynet/ip_dummynet.h> 88 89 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 90 x, (ntohl(a.s_addr)>>24)&0xFF,\ 91 (ntohl(a.s_addr)>>16)&0xFF,\ 92 (ntohl(a.s_addr)>>8)&0xFF,\ 93 (ntohl(a.s_addr))&0xFF, y); 94 95 u_short ip_id; 96 97 #ifdef MBUF_STRESS_TEST 98 int mbuf_frag_size = 0; 99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 101 #endif 102 103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 104 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 105 static void ip_mloopback 106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 107 static int ip_getmoptions 108 (struct sockopt *, struct ip_moptions *); 109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 110 static int ip_setmoptions 111 (struct sockopt *, struct ip_moptions **); 112 113 int ip_optcopy(struct ip *, struct ip *); 114 115 116 extern struct protosw inetsw[]; 117 118 /* 119 * IP output. The packet in mbuf chain m contains a skeletal IP 120 * header (with len, off, ttl, proto, tos, src, dst). 121 * The mbuf chain containing the packet will be freed. 122 * The mbuf opt, if present, will not be freed. 123 */ 124 int 125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 126 int flags, struct ip_moptions *imo, struct inpcb *inp) 127 { 128 struct ip *ip; 129 struct ifnet *ifp = NULL; /* keep compiler happy */ 130 struct mbuf *m; 131 int hlen = sizeof(struct ip); 132 int len, off, error = 0; 133 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 134 struct in_ifaddr *ia = NULL; 135 int isbroadcast, sw_csum; 136 struct in_addr pkt_dst; 137 struct route iproute; 138 #ifdef IPSEC 139 struct secpolicy *sp = NULL; 140 struct socket *so = inp ? inp->inp_socket : NULL; 141 #endif 142 #ifdef FAST_IPSEC 143 struct m_tag *mtag; 144 struct secpolicy *sp = NULL; 145 struct tdb_ident *tdbi; 146 int s; 147 #endif /* FAST_IPSEC */ 148 struct ip_fw_args args; 149 int src_was_INADDR_ANY = 0; /* as the name says... */ 150 151 args.eh = NULL; 152 args.rule = NULL; 153 args.next_hop = NULL; 154 args.divert_rule = 0; /* divert cookie */ 155 156 /* Grab info from MT_TAG mbufs prepended to the chain. */ 157 while (m0 != NULL && m0->m_type == MT_TAG) { 158 switch(m0->_m_tag_id) { 159 case PACKET_TAG_DUMMYNET: 160 /* 161 * the packet was already tagged, so part of the 162 * processing was already done, and we need to go down. 163 * Get parameters from the header. 164 */ 165 args.rule = ((struct dn_pkt *)m0)->rule; 166 opt = NULL ; 167 ro = &((struct dn_pkt *)m0)->ro; 168 imo = NULL ; 169 dst = ((struct dn_pkt *)m0)->dn_dst ; 170 ifp = ((struct dn_pkt *)m0)->ifp ; 171 flags = ((struct dn_pkt *)m0)->flags ; 172 break; 173 case PACKET_TAG_DIVERT: 174 args.divert_rule = (int)m0->m_data & 0xffff; 175 break; 176 case PACKET_TAG_IPFORWARD: 177 args.next_hop = (struct sockaddr_in *)m0->m_data; 178 break; 179 default: 180 printf("ip_output: unrecognised MT_TAG tag %d\n", 181 m0->_m_tag_id); 182 break; 183 } 184 m0 = m0->m_next; 185 } 186 m = m0; 187 KASSERT(m != NULL && (m->m_flags & M_PKTHDR), ("ip_output: no HDR")); 188 189 if (ro == NULL) { 190 ro = &iproute; 191 bzero(ro, sizeof *ro); 192 } 193 194 if (args.rule != NULL) { /* dummynet already saw us */ 195 ip = mtod(m, struct ip *); 196 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 197 if (ro->ro_rt) 198 ia = ifatoia(ro->ro_rt->rt_ifa); 199 goto sendit; 200 } 201 202 if (opt) { 203 len = 0; 204 m = ip_insertoptions(m, opt, &len); 205 if (len != 0) 206 hlen = len; 207 } 208 ip = mtod(m, struct ip *); 209 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 210 211 /* 212 * Fill in IP header. 213 */ 214 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 215 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 216 ip->ip_off &= IP_DF; 217 #ifdef RANDOM_IP_ID 218 ip->ip_id = ip_randomid(); 219 #else 220 ip->ip_id = htons(ip_id++); 221 #endif 222 ipstat.ips_localout++; 223 } else { 224 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 225 } 226 227 dst = (struct sockaddr_in *)&ro->ro_dst; 228 /* 229 * If there is a cached route, 230 * check that it is to the same destination 231 * and is still up. If not, free it and try again. 232 * The address family should also be checked in case of sharing the 233 * cache with IPv6. 234 */ 235 if (ro->ro_rt && 236 (!(ro->ro_rt->rt_flags & RTF_UP) || 237 dst->sin_family != AF_INET || 238 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 239 rtfree(ro->ro_rt); 240 ro->ro_rt = (struct rtentry *)NULL; 241 } 242 if (ro->ro_rt == NULL) { 243 bzero(dst, sizeof *dst); 244 dst->sin_family = AF_INET; 245 dst->sin_len = sizeof *dst; 246 dst->sin_addr = pkt_dst; 247 } 248 /* 249 * If routing to interface only, 250 * short circuit routing lookup. 251 */ 252 if (flags & IP_ROUTETOIF) { 253 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 254 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 255 ipstat.ips_noroute++; 256 error = ENETUNREACH; 257 goto bad; 258 } 259 ifp = ia->ia_ifp; 260 ip->ip_ttl = 1; 261 isbroadcast = in_broadcast(dst->sin_addr, ifp); 262 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 263 imo != NULL && imo->imo_multicast_ifp != NULL) { 264 /* 265 * Bypass the normal routing lookup for multicast 266 * packets if the interface is specified. 267 */ 268 ifp = imo->imo_multicast_ifp; 269 IFP_TO_IA(ifp, ia); 270 isbroadcast = 0; /* fool gcc */ 271 } else { 272 /* 273 * If this is the case, we probably don't want to allocate 274 * a protocol-cloned route since we didn't get one from the 275 * ULP. This lets TCP do its thing, while not burdening 276 * forwarding or ICMP with the overhead of cloning a route. 277 * Of course, we still want to do any cloning requested by 278 * the link layer, as this is probably required in all cases 279 * for correct operation (as it is for ARP). 280 */ 281 if (ro->ro_rt == NULL) 282 rtalloc_ign(ro, RTF_PRCLONING); 283 if (ro->ro_rt == NULL) { 284 ipstat.ips_noroute++; 285 error = EHOSTUNREACH; 286 goto bad; 287 } 288 ia = ifatoia(ro->ro_rt->rt_ifa); 289 ifp = ro->ro_rt->rt_ifp; 290 ro->ro_rt->rt_use++; 291 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 292 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 293 if (ro->ro_rt->rt_flags & RTF_HOST) 294 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 295 else 296 isbroadcast = in_broadcast(dst->sin_addr, ifp); 297 } 298 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 299 struct in_multi *inm; 300 301 m->m_flags |= M_MCAST; 302 /* 303 * IP destination address is multicast. Make sure "dst" 304 * still points to the address in "ro". (It may have been 305 * changed to point to a gateway address, above.) 306 */ 307 dst = (struct sockaddr_in *)&ro->ro_dst; 308 /* 309 * See if the caller provided any multicast options 310 */ 311 if (imo != NULL) { 312 ip->ip_ttl = imo->imo_multicast_ttl; 313 if (imo->imo_multicast_vif != -1) 314 ip->ip_src.s_addr = 315 ip_mcast_src ? 316 ip_mcast_src(imo->imo_multicast_vif) : 317 INADDR_ANY; 318 } else 319 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 320 /* 321 * Confirm that the outgoing interface supports multicast. 322 */ 323 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 324 if (!(ifp->if_flags & IFF_MULTICAST)) { 325 ipstat.ips_noroute++; 326 error = ENETUNREACH; 327 goto bad; 328 } 329 } 330 /* 331 * If source address not specified yet, use address 332 * of outgoing interface. 333 */ 334 if (ip->ip_src.s_addr == INADDR_ANY) { 335 /* Interface may have no addresses. */ 336 if (ia != NULL) 337 ip->ip_src = IA_SIN(ia)->sin_addr; 338 } 339 340 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 341 if (inm != NULL && 342 (imo == NULL || imo->imo_multicast_loop)) { 343 /* 344 * If we belong to the destination multicast group 345 * on the outgoing interface, and the caller did not 346 * forbid loopback, loop back a copy. 347 */ 348 ip_mloopback(ifp, m, dst, hlen); 349 } 350 else { 351 /* 352 * If we are acting as a multicast router, perform 353 * multicast forwarding as if the packet had just 354 * arrived on the interface to which we are about 355 * to send. The multicast forwarding function 356 * recursively calls this function, using the 357 * IP_FORWARDING flag to prevent infinite recursion. 358 * 359 * Multicasts that are looped back by ip_mloopback(), 360 * above, will be forwarded by the ip_input() routine, 361 * if necessary. 362 */ 363 if (ip_mrouter && !(flags & IP_FORWARDING)) { 364 /* 365 * If rsvp daemon is not running, do not 366 * set ip_moptions. This ensures that the packet 367 * is multicast and not just sent down one link 368 * as prescribed by rsvpd. 369 */ 370 if (!rsvp_on) 371 imo = NULL; 372 if (ip_mforward && 373 ip_mforward(ip, ifp, m, imo) != 0) { 374 m_freem(m); 375 goto done; 376 } 377 } 378 } 379 380 /* 381 * Multicasts with a time-to-live of zero may be looped- 382 * back, above, but must not be transmitted on a network. 383 * Also, multicasts addressed to the loopback interface 384 * are not sent -- the above call to ip_mloopback() will 385 * loop back a copy if this host actually belongs to the 386 * destination group on the loopback interface. 387 */ 388 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 389 m_freem(m); 390 goto done; 391 } 392 393 goto sendit; 394 } 395 #ifndef notdef 396 /* 397 * If the source address is not specified yet, use the address 398 * of the outoing interface. In case, keep note we did that, so 399 * if the the firewall changes the next-hop causing the output 400 * interface to change, we can fix that. 401 */ 402 if (ip->ip_src.s_addr == INADDR_ANY) { 403 /* Interface may have no addresses. */ 404 if (ia != NULL) { 405 ip->ip_src = IA_SIN(ia)->sin_addr; 406 src_was_INADDR_ANY = 1; 407 } 408 } 409 #endif /* notdef */ 410 #ifdef ALTQ 411 /* 412 * Disable packet drop hack. 413 * Packetdrop should be done by queueing. 414 */ 415 #else /* !ALTQ */ 416 /* 417 * Verify that we have any chance at all of being able to queue 418 * the packet or packet fragments 419 */ 420 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 421 ifp->if_snd.ifq_maxlen) { 422 error = ENOBUFS; 423 ipstat.ips_odropped++; 424 goto bad; 425 } 426 #endif /* !ALTQ */ 427 428 /* 429 * Look for broadcast address and 430 * verify user is allowed to send 431 * such a packet. 432 */ 433 if (isbroadcast) { 434 if (!(ifp->if_flags & IFF_BROADCAST)) { 435 error = EADDRNOTAVAIL; 436 goto bad; 437 } 438 if (!(flags & IP_ALLOWBROADCAST)) { 439 error = EACCES; 440 goto bad; 441 } 442 /* don't allow broadcast messages to be fragmented */ 443 if (ip->ip_len > ifp->if_mtu) { 444 error = EMSGSIZE; 445 goto bad; 446 } 447 m->m_flags |= M_BCAST; 448 } else { 449 m->m_flags &= ~M_BCAST; 450 } 451 452 sendit: 453 #ifdef IPSEC 454 /* get SP for this packet */ 455 if (so == NULL) 456 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 457 else 458 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 459 460 if (sp == NULL) { 461 ipsecstat.out_inval++; 462 goto bad; 463 } 464 465 error = 0; 466 467 /* check policy */ 468 switch (sp->policy) { 469 case IPSEC_POLICY_DISCARD: 470 /* 471 * This packet is just discarded. 472 */ 473 ipsecstat.out_polvio++; 474 goto bad; 475 476 case IPSEC_POLICY_BYPASS: 477 case IPSEC_POLICY_NONE: 478 /* no need to do IPsec. */ 479 goto skip_ipsec; 480 481 case IPSEC_POLICY_IPSEC: 482 if (sp->req == NULL) { 483 /* acquire a policy */ 484 error = key_spdacquire(sp); 485 goto bad; 486 } 487 break; 488 489 case IPSEC_POLICY_ENTRUST: 490 default: 491 printf("ip_output: Invalid policy found. %d\n", sp->policy); 492 } 493 { 494 struct ipsec_output_state state; 495 bzero(&state, sizeof state); 496 state.m = m; 497 if (flags & IP_ROUTETOIF) { 498 state.ro = &iproute; 499 bzero(&iproute, sizeof iproute); 500 } else 501 state.ro = ro; 502 state.dst = (struct sockaddr *)dst; 503 504 ip->ip_sum = 0; 505 506 /* 507 * XXX 508 * delayed checksums are not currently compatible with IPsec 509 */ 510 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 511 in_delayed_cksum(m); 512 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 513 } 514 515 ip->ip_len = htons(ip->ip_len); 516 ip->ip_off = htons(ip->ip_off); 517 518 error = ipsec4_output(&state, sp, flags); 519 520 m = state.m; 521 if (flags & IP_ROUTETOIF) { 522 /* 523 * if we have tunnel mode SA, we may need to ignore 524 * IP_ROUTETOIF. 525 */ 526 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 527 flags &= ~IP_ROUTETOIF; 528 ro = state.ro; 529 } 530 } else 531 ro = state.ro; 532 dst = (struct sockaddr_in *)state.dst; 533 if (error) { 534 /* mbuf is already reclaimed in ipsec4_output. */ 535 m0 = NULL; 536 switch (error) { 537 case EHOSTUNREACH: 538 case ENETUNREACH: 539 case EMSGSIZE: 540 case ENOBUFS: 541 case ENOMEM: 542 break; 543 default: 544 printf("ip4_output (ipsec): error code %d\n", error); 545 /*fall through*/ 546 case ENOENT: 547 /* don't show these error codes to the user */ 548 error = 0; 549 break; 550 } 551 goto bad; 552 } 553 } 554 555 /* be sure to update variables that are affected by ipsec4_output() */ 556 ip = mtod(m, struct ip *); 557 #ifdef _IP_VHL 558 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 559 #else 560 hlen = ip->ip_hl << 2; 561 #endif 562 if (ro->ro_rt == NULL) { 563 if (!(flags & IP_ROUTETOIF)) { 564 printf("ip_output: " 565 "can't update route after IPsec processing\n"); 566 error = EHOSTUNREACH; /*XXX*/ 567 goto bad; 568 } 569 } else { 570 ia = ifatoia(ro->ro_rt->rt_ifa); 571 ifp = ro->ro_rt->rt_ifp; 572 } 573 574 /* make it flipped, again. */ 575 ip->ip_len = ntohs(ip->ip_len); 576 ip->ip_off = ntohs(ip->ip_off); 577 skip_ipsec: 578 #endif /*IPSEC*/ 579 #ifdef FAST_IPSEC 580 /* 581 * Check the security policy (SP) for the packet and, if 582 * required, do IPsec-related processing. There are two 583 * cases here; the first time a packet is sent through 584 * it will be untagged and handled by ipsec4_checkpolicy. 585 * If the packet is resubmitted to ip_output (e.g. after 586 * AH, ESP, etc. processing), there will be a tag to bypass 587 * the lookup and related policy checking. 588 */ 589 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 590 s = splnet(); 591 if (mtag != NULL) { 592 tdbi = (struct tdb_ident *)(mtag + 1); 593 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 594 if (sp == NULL) 595 error = -EINVAL; /* force silent drop */ 596 m_tag_delete(m, mtag); 597 } else { 598 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 599 &error, inp); 600 } 601 /* 602 * There are four return cases: 603 * sp != NULL apply IPsec policy 604 * sp == NULL, error == 0 no IPsec handling needed 605 * sp == NULL, error == -EINVAL discard packet w/o error 606 * sp == NULL, error != 0 discard packet, report error 607 */ 608 if (sp != NULL) { 609 /* Loop detection, check if ipsec processing already done */ 610 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 611 for (mtag = m_tag_first(m); mtag != NULL; 612 mtag = m_tag_next(m, mtag)) { 613 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 614 continue; 615 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 616 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 617 continue; 618 /* 619 * Check if policy has an SA associated with it. 620 * This can happen when an SP has yet to acquire 621 * an SA; e.g. on first reference. If it occurs, 622 * then we let ipsec4_process_packet do its thing. 623 */ 624 if (sp->req->sav == NULL) 625 break; 626 tdbi = (struct tdb_ident *)(mtag + 1); 627 if (tdbi->spi == sp->req->sav->spi && 628 tdbi->proto == sp->req->sav->sah->saidx.proto && 629 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 630 sizeof(union sockaddr_union)) == 0) { 631 /* 632 * No IPsec processing is needed, free 633 * reference to SP. 634 * 635 * NB: null pointer to avoid free at 636 * done: below. 637 */ 638 KEY_FREESP(&sp), sp = NULL; 639 splx(s); 640 goto spd_done; 641 } 642 } 643 644 /* 645 * Do delayed checksums now because we send before 646 * this is done in the normal processing path. 647 */ 648 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 649 in_delayed_cksum(m); 650 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 651 } 652 653 ip->ip_len = htons(ip->ip_len); 654 ip->ip_off = htons(ip->ip_off); 655 656 /* NB: callee frees mbuf */ 657 error = ipsec4_process_packet(m, sp->req, flags, 0); 658 /* 659 * Preserve KAME behaviour: ENOENT can be returned 660 * when an SA acquire is in progress. Don't propagate 661 * this to user-level; it confuses applications. 662 * 663 * XXX this will go away when the SADB is redone. 664 */ 665 if (error == ENOENT) 666 error = 0; 667 splx(s); 668 goto done; 669 } else { 670 splx(s); 671 672 if (error != 0) { 673 /* 674 * Hack: -EINVAL is used to signal that a packet 675 * should be silently discarded. This is typically 676 * because we asked key management for an SA and 677 * it was delayed (e.g. kicked up to IKE). 678 */ 679 if (error == -EINVAL) 680 error = 0; 681 goto bad; 682 } else { 683 /* No IPsec processing for this packet. */ 684 } 685 #ifdef notyet 686 /* 687 * If deferred crypto processing is needed, check that 688 * the interface supports it. 689 */ 690 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 691 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 692 /* notify IPsec to do its own crypto */ 693 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 694 error = EHOSTUNREACH; 695 goto bad; 696 } 697 #endif 698 } 699 spd_done: 700 #endif /* FAST_IPSEC */ 701 /* 702 * IpHack's section. 703 * - Xlate: translate packet's addr/port (NAT). 704 * - Firewall: deny/allow/etc. 705 * - Wrap: fake packet's addr/port <unimpl.> 706 * - Encapsulate: put it in another IP and send out. <unimp.> 707 */ 708 709 /* 710 * Run through list of hooks for output packets. 711 */ 712 if (pfil_has_hooks(&inet_pfil_hook)) { 713 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 714 if (error != 0 || m == NULL) 715 goto done; 716 ip = mtod(m, struct ip *); 717 } 718 719 /* 720 * Check with the firewall... 721 * but not if we are already being fwd'd from a firewall. 722 */ 723 if (fw_enable && IPFW_LOADED && !args.next_hop) { 724 struct sockaddr_in *old = dst; 725 726 args.m = m; 727 args.next_hop = dst; 728 args.oif = ifp; 729 off = ip_fw_chk_ptr(&args); 730 m = args.m; 731 dst = args.next_hop; 732 733 /* 734 * On return we must do the following: 735 * m == NULL -> drop the pkt (old interface, deprecated) 736 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 737 * 1<=off<= 0xffff -> DIVERT 738 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 739 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 740 * dst != old -> IPFIREWALL_FORWARD 741 * off==0, dst==old -> accept 742 * If some of the above modules are not compiled in, then 743 * we should't have to check the corresponding condition 744 * (because the ipfw control socket should not accept 745 * unsupported rules), but better play safe and drop 746 * packets in case of doubt. 747 */ 748 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 749 if (m) 750 m_freem(m); 751 error = EACCES; 752 goto done; 753 } 754 ip = mtod(m, struct ip *); 755 if (off == 0 && dst == old) /* common case */ 756 goto pass; 757 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG)) { 758 /* 759 * pass the pkt to dummynet. Need to include 760 * pipe number, m, ifp, ro, dst because these are 761 * not recomputed in the next pass. 762 * All other parameters have been already used and 763 * so they are not needed anymore. 764 * XXX note: if the ifp or ro entry are deleted 765 * while a pkt is in dummynet, we are in trouble! 766 */ 767 args.ro = ro; 768 args.dst = dst; 769 args.flags = flags; 770 771 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 772 &args); 773 goto done; 774 } 775 #ifdef IPDIVERT 776 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) { 777 struct mbuf *clone = NULL; 778 779 /* Clone packet if we're doing a 'tee' */ 780 if ((off & IP_FW_PORT_TEE_FLAG)) 781 clone = m_dup(m, MB_DONTWAIT); 782 783 /* 784 * XXX 785 * delayed checksums are not currently compatible 786 * with divert sockets. 787 */ 788 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 789 in_delayed_cksum(m); 790 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 791 } 792 793 /* Restore packet header fields to original values */ 794 ip->ip_len = htons(ip->ip_len); 795 ip->ip_off = htons(ip->ip_off); 796 797 /* Deliver packet to divert input routine */ 798 divert_packet(m, 0, off & 0xffff, args.divert_rule); 799 800 /* If 'tee', continue with original packet */ 801 if (clone != NULL) { 802 m = clone; 803 ip = mtod(m, struct ip *); 804 goto pass; 805 } 806 goto done; 807 } 808 #endif 809 810 /* IPFIREWALL_FORWARD */ 811 /* 812 * Check dst to make sure it is directly reachable on the 813 * interface we previously thought it was. 814 * If it isn't (which may be likely in some situations) we have 815 * to re-route it (ie, find a route for the next-hop and the 816 * associated interface) and set them here. This is nested 817 * forwarding which in most cases is undesirable, except where 818 * such control is nigh impossible. So we do it here. 819 * And I'm babbling. 820 */ 821 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 822 #if 0 823 /* 824 * XXX To improve readability, this block should be 825 * changed into a function call as below: 826 */ 827 error = ip_ipforward(&m, &dst, &ifp); 828 if (error) 829 goto bad; 830 if (m == NULL) /* ip_input consumed the mbuf */ 831 goto done; 832 #else 833 struct in_ifaddr *ia; 834 835 /* 836 * XXX sro_fwd below is static, and a pointer 837 * to it gets passed to routines downstream. 838 * This could have surprisingly bad results in 839 * practice, because its content is overwritten 840 * by subsequent packets. 841 */ 842 /* There must be a better way to do this next line... */ 843 static struct route sro_fwd; 844 struct route *ro_fwd = &sro_fwd; 845 846 #if 0 847 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 848 dst->sin_addr, "\n"); 849 #endif 850 851 /* 852 * We need to figure out if we have been forwarded 853 * to a local socket. If so, then we should somehow 854 * "loop back" to ip_input, and get directed to the 855 * PCB as if we had received this packet. This is 856 * because it may be dificult to identify the packets 857 * you want to forward until they are being output 858 * and have selected an interface. (e.g. locally 859 * initiated packets) If we used the loopback inteface, 860 * we would not be able to control what happens 861 * as the packet runs through ip_input() as 862 * it is done through a ISR. 863 */ 864 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr), 865 ia_hash) { 866 /* 867 * If the addr to forward to is one 868 * of ours, we pretend to 869 * be the destination for this packet. 870 */ 871 if (IA_SIN(ia)->sin_addr.s_addr == 872 dst->sin_addr.s_addr) 873 break; 874 } 875 if (ia != NULL) { /* tell ip_input "dont filter" */ 876 struct m_hdr tag; 877 878 tag.mh_type = MT_TAG; 879 tag.mh_flags = PACKET_TAG_IPFORWARD; 880 tag.mh_data = (caddr_t)args.next_hop; 881 tag.mh_next = m; 882 883 if (m->m_pkthdr.rcvif == NULL) 884 m->m_pkthdr.rcvif = ifunit("lo0"); 885 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 886 m->m_pkthdr.csum_flags |= 887 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 888 m0->m_pkthdr.csum_data = 0xffff; 889 } 890 m->m_pkthdr.csum_flags |= 891 CSUM_IP_CHECKED | CSUM_IP_VALID; 892 ip->ip_len = htons(ip->ip_len); 893 ip->ip_off = htons(ip->ip_off); 894 ip_input((struct mbuf *)&tag); 895 goto done; 896 } 897 /* Some of the logic for this was nicked from above. 898 * 899 * This rewrites the cached route in a local PCB. 900 * Is this what we want to do? 901 */ 902 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst); 903 ro_fwd->ro_rt = NULL; 904 905 rtalloc_ign(ro_fwd, RTF_PRCLONING); 906 if (ro_fwd->ro_rt == NULL) { 907 ipstat.ips_noroute++; 908 error = EHOSTUNREACH; 909 goto bad; 910 } 911 912 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 913 ifp = ro_fwd->ro_rt->rt_ifp; 914 ro_fwd->ro_rt->rt_use++; 915 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 916 dst = (struct sockaddr_in *) 917 ro_fwd->ro_rt->rt_gateway; 918 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 919 isbroadcast = 920 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 921 else 922 isbroadcast = in_broadcast(dst->sin_addr, ifp); 923 if (ro->ro_rt != NULL) 924 rtfree(ro->ro_rt); 925 ro->ro_rt = ro_fwd->ro_rt; 926 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 927 928 #endif /* ... block to be put into a function */ 929 /* 930 * If we added a default src ip earlier, 931 * which would have been gotten from the-then 932 * interface, do it again, from the new one. 933 */ 934 if (src_was_INADDR_ANY) 935 ip->ip_src = IA_SIN(ia)->sin_addr; 936 goto pass ; 937 } 938 939 /* 940 * if we get here, none of the above matches, and 941 * we have to drop the pkt 942 */ 943 m_freem(m); 944 error = EACCES; /* not sure this is the right error msg */ 945 goto done; 946 } 947 948 pass: 949 /* 127/8 must not appear on wire - RFC1122. */ 950 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 951 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 952 if (!(ifp->if_flags & IFF_LOOPBACK)) { 953 ipstat.ips_badaddr++; 954 error = EADDRNOTAVAIL; 955 goto bad; 956 } 957 } 958 959 m->m_pkthdr.csum_flags |= CSUM_IP; 960 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 961 if (sw_csum & CSUM_DELAY_DATA) { 962 in_delayed_cksum(m); 963 sw_csum &= ~CSUM_DELAY_DATA; 964 } 965 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 966 967 /* 968 * If small enough for interface, or the interface will take 969 * care of the fragmentation for us, can just send directly. 970 */ 971 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 972 !(ip->ip_off & IP_DF))) { 973 ip->ip_len = htons(ip->ip_len); 974 ip->ip_off = htons(ip->ip_off); 975 ip->ip_sum = 0; 976 if (sw_csum & CSUM_DELAY_IP) { 977 if (ip->ip_vhl == IP_VHL_BORING) { 978 ip->ip_sum = in_cksum_hdr(ip); 979 } else { 980 ip->ip_sum = in_cksum(m, hlen); 981 } 982 } 983 984 /* Record statistics for this interface address. */ 985 if (!(flags & IP_FORWARDING) && ia) { 986 ia->ia_ifa.if_opackets++; 987 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 988 } 989 990 #ifdef IPSEC 991 /* clean ipsec history once it goes out of the node */ 992 ipsec_delaux(m); 993 #endif 994 995 #ifdef MBUF_STRESS_TEST 996 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 997 struct mbuf *m1, *m2; 998 int length, tmp; 999 1000 tmp = length = m->m_pkthdr.len; 1001 1002 while ((length -= mbuf_frag_size) >= 1) { 1003 m1 = m_split(m, length, MB_DONTWAIT); 1004 if (m1 == NULL) 1005 break; 1006 m1->m_flags &= ~M_PKTHDR; 1007 m2 = m; 1008 while (m2->m_next != NULL) 1009 m2 = m2->m_next; 1010 m2->m_next = m1; 1011 } 1012 m->m_pkthdr.len = tmp; 1013 } 1014 #endif 1015 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, 1016 ro->ro_rt); 1017 goto done; 1018 } 1019 1020 if (ip->ip_off & IP_DF) { 1021 error = EMSGSIZE; 1022 /* 1023 * This case can happen if the user changed the MTU 1024 * of an interface after enabling IP on it. Because 1025 * most netifs don't keep track of routes pointing to 1026 * them, there is no way for one to update all its 1027 * routes when the MTU is changed. 1028 */ 1029 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1030 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1031 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1032 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1033 } 1034 ipstat.ips_cantfrag++; 1035 goto bad; 1036 } 1037 1038 /* 1039 * Too large for interface; fragment if possible. If successful, 1040 * on return, m will point to a list of packets to be sent. 1041 */ 1042 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1043 if (error) 1044 goto bad; 1045 for (; m; m = m0) { 1046 m0 = m->m_nextpkt; 1047 m->m_nextpkt = NULL; 1048 #ifdef IPSEC 1049 /* clean ipsec history once it goes out of the node */ 1050 ipsec_delaux(m); 1051 #endif 1052 if (error == 0) { 1053 /* Record statistics for this interface address. */ 1054 if (ia != NULL) { 1055 ia->ia_ifa.if_opackets++; 1056 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1057 } 1058 error = (*ifp->if_output)(ifp, m, 1059 (struct sockaddr *)dst, 1060 ro->ro_rt); 1061 } else 1062 m_freem(m); 1063 } 1064 1065 if (error == 0) 1066 ipstat.ips_fragmented++; 1067 1068 done: 1069 if (ro == &iproute && ro->ro_rt != NULL) { 1070 RTFREE(ro->ro_rt); 1071 ro->ro_rt = NULL; 1072 } 1073 #ifdef IPSEC 1074 if (sp != NULL) { 1075 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1076 printf("DP ip_output call free SP:%p\n", sp)); 1077 key_freesp(sp); 1078 } 1079 #endif 1080 #ifdef FAST_IPSEC 1081 if (sp != NULL) 1082 KEY_FREESP(&sp); 1083 #endif 1084 return (error); 1085 bad: 1086 m_freem(m); 1087 goto done; 1088 } 1089 1090 /* 1091 * Create a chain of fragments which fit the given mtu. m_frag points to the 1092 * mbuf to be fragmented; on return it points to the chain with the fragments. 1093 * Return 0 if no error. If error, m_frag may contain a partially built 1094 * chain of fragments that should be freed by the caller. 1095 * 1096 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1097 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1098 */ 1099 int 1100 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1101 u_long if_hwassist_flags, int sw_csum) 1102 { 1103 int error = 0; 1104 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1105 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1106 int off; 1107 struct mbuf *m0 = *m_frag; /* the original packet */ 1108 int firstlen; 1109 struct mbuf **mnext; 1110 int nfrags; 1111 1112 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1113 ipstat.ips_cantfrag++; 1114 return EMSGSIZE; 1115 } 1116 1117 /* 1118 * Must be able to put at least 8 bytes per fragment. 1119 */ 1120 if (len < 8) 1121 return EMSGSIZE; 1122 1123 /* 1124 * If the interface will not calculate checksums on 1125 * fragmented packets, then do it here. 1126 */ 1127 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1128 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1129 in_delayed_cksum(m0); 1130 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1131 } 1132 1133 if (len > PAGE_SIZE) { 1134 /* 1135 * Fragment large datagrams such that each segment 1136 * contains a multiple of PAGE_SIZE amount of data, 1137 * plus headers. This enables a receiver to perform 1138 * page-flipping zero-copy optimizations. 1139 * 1140 * XXX When does this help given that sender and receiver 1141 * could have different page sizes, and also mtu could 1142 * be less than the receiver's page size ? 1143 */ 1144 int newlen; 1145 struct mbuf *m; 1146 1147 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1148 off += m->m_len; 1149 1150 /* 1151 * firstlen (off - hlen) must be aligned on an 1152 * 8-byte boundary 1153 */ 1154 if (off < hlen) 1155 goto smart_frag_failure; 1156 off = ((off - hlen) & ~7) + hlen; 1157 newlen = (~PAGE_MASK) & mtu; 1158 if ((newlen + sizeof(struct ip)) > mtu) { 1159 /* we failed, go back the default */ 1160 smart_frag_failure: 1161 newlen = len; 1162 off = hlen + len; 1163 } 1164 len = newlen; 1165 1166 } else { 1167 off = hlen + len; 1168 } 1169 1170 firstlen = off - hlen; 1171 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1172 1173 /* 1174 * Loop through length of segment after first fragment, 1175 * make new header and copy data of each part and link onto chain. 1176 * Here, m0 is the original packet, m is the fragment being created. 1177 * The fragments are linked off the m_nextpkt of the original 1178 * packet, which after processing serves as the first fragment. 1179 */ 1180 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1181 struct ip *mhip; /* ip header on the fragment */ 1182 struct mbuf *m; 1183 int mhlen = sizeof(struct ip); 1184 1185 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1186 if (m == NULL) { 1187 error = ENOBUFS; 1188 ipstat.ips_odropped++; 1189 goto done; 1190 } 1191 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1192 /* 1193 * In the first mbuf, leave room for the link header, then 1194 * copy the original IP header including options. The payload 1195 * goes into an additional mbuf chain returned by m_copy(). 1196 */ 1197 m->m_data += max_linkhdr; 1198 mhip = mtod(m, struct ip *); 1199 *mhip = *ip; 1200 if (hlen > sizeof(struct ip)) { 1201 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1202 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1203 } 1204 m->m_len = mhlen; 1205 /* XXX do we need to add ip->ip_off below ? */ 1206 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1207 if (off + len >= ip->ip_len) { /* last fragment */ 1208 len = ip->ip_len - off; 1209 m->m_flags |= M_LASTFRAG; 1210 } else 1211 mhip->ip_off |= IP_MF; 1212 mhip->ip_len = htons((u_short)(len + mhlen)); 1213 m->m_next = m_copy(m0, off, len); 1214 if (m->m_next == NULL) { /* copy failed */ 1215 m_free(m); 1216 error = ENOBUFS; /* ??? */ 1217 ipstat.ips_odropped++; 1218 goto done; 1219 } 1220 m->m_pkthdr.len = mhlen + len; 1221 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1222 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1223 mhip->ip_off = htons(mhip->ip_off); 1224 mhip->ip_sum = 0; 1225 if (sw_csum & CSUM_DELAY_IP) 1226 mhip->ip_sum = in_cksum(m, mhlen); 1227 *mnext = m; 1228 mnext = &m->m_nextpkt; 1229 } 1230 ipstat.ips_ofragments += nfrags; 1231 1232 /* set first marker for fragment chain */ 1233 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1234 m0->m_pkthdr.csum_data = nfrags; 1235 1236 /* 1237 * Update first fragment by trimming what's been copied out 1238 * and updating header. 1239 */ 1240 m_adj(m0, hlen + firstlen - ip->ip_len); 1241 m0->m_pkthdr.len = hlen + firstlen; 1242 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1243 ip->ip_off |= IP_MF; 1244 ip->ip_off = htons(ip->ip_off); 1245 ip->ip_sum = 0; 1246 if (sw_csum & CSUM_DELAY_IP) 1247 ip->ip_sum = in_cksum(m0, hlen); 1248 1249 done: 1250 *m_frag = m0; 1251 return error; 1252 } 1253 1254 void 1255 in_delayed_cksum(struct mbuf *m) 1256 { 1257 struct ip *ip; 1258 u_short csum, offset; 1259 1260 ip = mtod(m, struct ip *); 1261 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1262 csum = in_cksum_skip(m, ip->ip_len, offset); 1263 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1264 csum = 0xffff; 1265 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1266 1267 if (offset + sizeof(u_short) > m->m_len) { 1268 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1269 m->m_len, offset, ip->ip_p); 1270 /* 1271 * XXX 1272 * this shouldn't happen, but if it does, the 1273 * correct behavior may be to insert the checksum 1274 * in the existing chain instead of rearranging it. 1275 */ 1276 m = m_pullup(m, offset + sizeof(u_short)); 1277 } 1278 *(u_short *)(m->m_data + offset) = csum; 1279 } 1280 1281 /* 1282 * Insert IP options into preformed packet. 1283 * Adjust IP destination as required for IP source routing, 1284 * as indicated by a non-zero in_addr at the start of the options. 1285 * 1286 * XXX This routine assumes that the packet has no options in place. 1287 */ 1288 static struct mbuf * 1289 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1290 { 1291 struct ipoption *p = mtod(opt, struct ipoption *); 1292 struct mbuf *n; 1293 struct ip *ip = mtod(m, struct ip *); 1294 unsigned optlen; 1295 1296 optlen = opt->m_len - sizeof p->ipopt_dst; 1297 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1298 *phlen = 0; 1299 return (m); /* XXX should fail */ 1300 } 1301 if (p->ipopt_dst.s_addr) 1302 ip->ip_dst = p->ipopt_dst; 1303 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1304 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1305 if (n == NULL) { 1306 *phlen = 0; 1307 return (m); 1308 } 1309 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 1310 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1311 m->m_len -= sizeof(struct ip); 1312 m->m_data += sizeof(struct ip); 1313 n->m_next = m; 1314 m = n; 1315 m->m_len = optlen + sizeof(struct ip); 1316 m->m_data += max_linkhdr; 1317 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1318 } else { 1319 m->m_data -= optlen; 1320 m->m_len += optlen; 1321 m->m_pkthdr.len += optlen; 1322 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1323 } 1324 ip = mtod(m, struct ip *); 1325 bcopy(p->ipopt_list, ip + 1, optlen); 1326 *phlen = sizeof(struct ip) + optlen; 1327 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1328 ip->ip_len += optlen; 1329 return (m); 1330 } 1331 1332 /* 1333 * Copy options from ip to jp, 1334 * omitting those not copied during fragmentation. 1335 */ 1336 int 1337 ip_optcopy(struct ip *ip, struct ip *jp) 1338 { 1339 u_char *cp, *dp; 1340 int opt, optlen, cnt; 1341 1342 cp = (u_char *)(ip + 1); 1343 dp = (u_char *)(jp + 1); 1344 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1345 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1346 opt = cp[0]; 1347 if (opt == IPOPT_EOL) 1348 break; 1349 if (opt == IPOPT_NOP) { 1350 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1351 *dp++ = IPOPT_NOP; 1352 optlen = 1; 1353 continue; 1354 } 1355 1356 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1357 ("ip_optcopy: malformed ipv4 option")); 1358 optlen = cp[IPOPT_OLEN]; 1359 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1360 ("ip_optcopy: malformed ipv4 option")); 1361 1362 /* bogus lengths should have been caught by ip_dooptions */ 1363 if (optlen > cnt) 1364 optlen = cnt; 1365 if (IPOPT_COPIED(opt)) { 1366 bcopy(cp, dp, optlen); 1367 dp += optlen; 1368 } 1369 } 1370 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1371 *dp++ = IPOPT_EOL; 1372 return (optlen); 1373 } 1374 1375 /* 1376 * IP socket option processing. 1377 */ 1378 int 1379 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1380 { 1381 struct inpcb *inp = so->so_pcb; 1382 int error, optval; 1383 1384 error = optval = 0; 1385 if (sopt->sopt_level != IPPROTO_IP) { 1386 return (EINVAL); 1387 } 1388 1389 switch (sopt->sopt_dir) { 1390 case SOPT_SET: 1391 switch (sopt->sopt_name) { 1392 case IP_OPTIONS: 1393 #ifdef notyet 1394 case IP_RETOPTS: 1395 #endif 1396 { 1397 struct mbuf *m; 1398 if (sopt->sopt_valsize > MLEN) { 1399 error = EMSGSIZE; 1400 break; 1401 } 1402 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1403 if (m == NULL) { 1404 error = ENOBUFS; 1405 break; 1406 } 1407 m->m_len = sopt->sopt_valsize; 1408 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1409 m->m_len); 1410 1411 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1412 m)); 1413 } 1414 1415 case IP_TOS: 1416 case IP_TTL: 1417 case IP_RECVOPTS: 1418 case IP_RECVRETOPTS: 1419 case IP_RECVDSTADDR: 1420 case IP_RECVIF: 1421 case IP_FAITH: 1422 error = sooptcopyin(sopt, &optval, sizeof optval, 1423 sizeof optval); 1424 if (error) 1425 break; 1426 1427 switch (sopt->sopt_name) { 1428 case IP_TOS: 1429 inp->inp_ip_tos = optval; 1430 break; 1431 1432 case IP_TTL: 1433 inp->inp_ip_ttl = optval; 1434 break; 1435 #define OPTSET(bit) \ 1436 if (optval) \ 1437 inp->inp_flags |= bit; \ 1438 else \ 1439 inp->inp_flags &= ~bit; 1440 1441 case IP_RECVOPTS: 1442 OPTSET(INP_RECVOPTS); 1443 break; 1444 1445 case IP_RECVRETOPTS: 1446 OPTSET(INP_RECVRETOPTS); 1447 break; 1448 1449 case IP_RECVDSTADDR: 1450 OPTSET(INP_RECVDSTADDR); 1451 break; 1452 1453 case IP_RECVIF: 1454 OPTSET(INP_RECVIF); 1455 break; 1456 1457 case IP_FAITH: 1458 OPTSET(INP_FAITH); 1459 break; 1460 } 1461 break; 1462 #undef OPTSET 1463 1464 case IP_MULTICAST_IF: 1465 case IP_MULTICAST_VIF: 1466 case IP_MULTICAST_TTL: 1467 case IP_MULTICAST_LOOP: 1468 case IP_ADD_MEMBERSHIP: 1469 case IP_DROP_MEMBERSHIP: 1470 error = ip_setmoptions(sopt, &inp->inp_moptions); 1471 break; 1472 1473 case IP_PORTRANGE: 1474 error = sooptcopyin(sopt, &optval, sizeof optval, 1475 sizeof optval); 1476 if (error) 1477 break; 1478 1479 switch (optval) { 1480 case IP_PORTRANGE_DEFAULT: 1481 inp->inp_flags &= ~(INP_LOWPORT); 1482 inp->inp_flags &= ~(INP_HIGHPORT); 1483 break; 1484 1485 case IP_PORTRANGE_HIGH: 1486 inp->inp_flags &= ~(INP_LOWPORT); 1487 inp->inp_flags |= INP_HIGHPORT; 1488 break; 1489 1490 case IP_PORTRANGE_LOW: 1491 inp->inp_flags &= ~(INP_HIGHPORT); 1492 inp->inp_flags |= INP_LOWPORT; 1493 break; 1494 1495 default: 1496 error = EINVAL; 1497 break; 1498 } 1499 break; 1500 1501 #if defined(IPSEC) || defined(FAST_IPSEC) 1502 case IP_IPSEC_POLICY: 1503 { 1504 caddr_t req; 1505 size_t len = 0; 1506 int priv; 1507 struct mbuf *m; 1508 int optname; 1509 1510 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1511 break; 1512 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1513 break; 1514 priv = (sopt->sopt_td != NULL && 1515 suser(sopt->sopt_td) != 0) ? 0 : 1; 1516 req = mtod(m, caddr_t); 1517 len = m->m_len; 1518 optname = sopt->sopt_name; 1519 error = ipsec4_set_policy(inp, optname, req, len, priv); 1520 m_freem(m); 1521 break; 1522 } 1523 #endif /*IPSEC*/ 1524 1525 default: 1526 error = ENOPROTOOPT; 1527 break; 1528 } 1529 break; 1530 1531 case SOPT_GET: 1532 switch (sopt->sopt_name) { 1533 case IP_OPTIONS: 1534 case IP_RETOPTS: 1535 if (inp->inp_options) 1536 error = sooptcopyout(sopt, 1537 mtod(inp->inp_options, 1538 char *), 1539 inp->inp_options->m_len); 1540 else 1541 sopt->sopt_valsize = 0; 1542 break; 1543 1544 case IP_TOS: 1545 case IP_TTL: 1546 case IP_RECVOPTS: 1547 case IP_RECVRETOPTS: 1548 case IP_RECVDSTADDR: 1549 case IP_RECVIF: 1550 case IP_PORTRANGE: 1551 case IP_FAITH: 1552 switch (sopt->sopt_name) { 1553 1554 case IP_TOS: 1555 optval = inp->inp_ip_tos; 1556 break; 1557 1558 case IP_TTL: 1559 optval = inp->inp_ip_ttl; 1560 break; 1561 1562 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1563 1564 case IP_RECVOPTS: 1565 optval = OPTBIT(INP_RECVOPTS); 1566 break; 1567 1568 case IP_RECVRETOPTS: 1569 optval = OPTBIT(INP_RECVRETOPTS); 1570 break; 1571 1572 case IP_RECVDSTADDR: 1573 optval = OPTBIT(INP_RECVDSTADDR); 1574 break; 1575 1576 case IP_RECVIF: 1577 optval = OPTBIT(INP_RECVIF); 1578 break; 1579 1580 case IP_PORTRANGE: 1581 if (inp->inp_flags & INP_HIGHPORT) 1582 optval = IP_PORTRANGE_HIGH; 1583 else if (inp->inp_flags & INP_LOWPORT) 1584 optval = IP_PORTRANGE_LOW; 1585 else 1586 optval = 0; 1587 break; 1588 1589 case IP_FAITH: 1590 optval = OPTBIT(INP_FAITH); 1591 break; 1592 } 1593 error = sooptcopyout(sopt, &optval, sizeof optval); 1594 break; 1595 1596 case IP_MULTICAST_IF: 1597 case IP_MULTICAST_VIF: 1598 case IP_MULTICAST_TTL: 1599 case IP_MULTICAST_LOOP: 1600 case IP_ADD_MEMBERSHIP: 1601 case IP_DROP_MEMBERSHIP: 1602 error = ip_getmoptions(sopt, inp->inp_moptions); 1603 break; 1604 1605 #if defined(IPSEC) || defined(FAST_IPSEC) 1606 case IP_IPSEC_POLICY: 1607 { 1608 struct mbuf *m = NULL; 1609 caddr_t req = NULL; 1610 size_t len = 0; 1611 1612 if (m != NULL) { 1613 req = mtod(m, caddr_t); 1614 len = m->m_len; 1615 } 1616 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1617 if (error == 0) 1618 error = soopt_mcopyout(sopt, m); /* XXX */ 1619 if (error == 0) 1620 m_freem(m); 1621 break; 1622 } 1623 #endif /*IPSEC*/ 1624 1625 default: 1626 error = ENOPROTOOPT; 1627 break; 1628 } 1629 break; 1630 } 1631 return (error); 1632 } 1633 1634 /* 1635 * Set up IP options in pcb for insertion in output packets. 1636 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1637 * with destination address if source routed. 1638 */ 1639 static int 1640 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1641 { 1642 int cnt, optlen; 1643 u_char *cp; 1644 u_char opt; 1645 1646 /* turn off any old options */ 1647 if (*pcbopt) 1648 m_free(*pcbopt); 1649 *pcbopt = 0; 1650 if (m == NULL || m->m_len == 0) { 1651 /* 1652 * Only turning off any previous options. 1653 */ 1654 if (m != NULL) 1655 m_free(m); 1656 return (0); 1657 } 1658 1659 if (m->m_len % sizeof(int32_t)) 1660 goto bad; 1661 /* 1662 * IP first-hop destination address will be stored before 1663 * actual options; move other options back 1664 * and clear it when none present. 1665 */ 1666 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1667 goto bad; 1668 cnt = m->m_len; 1669 m->m_len += sizeof(struct in_addr); 1670 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1671 ovbcopy(mtod(m, caddr_t), cp, cnt); 1672 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1673 1674 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1675 opt = cp[IPOPT_OPTVAL]; 1676 if (opt == IPOPT_EOL) 1677 break; 1678 if (opt == IPOPT_NOP) 1679 optlen = 1; 1680 else { 1681 if (cnt < IPOPT_OLEN + sizeof *cp) 1682 goto bad; 1683 optlen = cp[IPOPT_OLEN]; 1684 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1685 goto bad; 1686 } 1687 switch (opt) { 1688 1689 default: 1690 break; 1691 1692 case IPOPT_LSRR: 1693 case IPOPT_SSRR: 1694 /* 1695 * user process specifies route as: 1696 * ->A->B->C->D 1697 * D must be our final destination (but we can't 1698 * check that since we may not have connected yet). 1699 * A is first hop destination, which doesn't appear in 1700 * actual IP option, but is stored before the options. 1701 */ 1702 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1703 goto bad; 1704 m->m_len -= sizeof(struct in_addr); 1705 cnt -= sizeof(struct in_addr); 1706 optlen -= sizeof(struct in_addr); 1707 cp[IPOPT_OLEN] = optlen; 1708 /* 1709 * Move first hop before start of options. 1710 */ 1711 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1712 sizeof(struct in_addr)); 1713 /* 1714 * Then copy rest of options back 1715 * to close up the deleted entry. 1716 */ 1717 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1718 &cp[IPOPT_OFFSET+1], 1719 cnt - (IPOPT_MINOFF - 1)); 1720 break; 1721 } 1722 } 1723 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1724 goto bad; 1725 *pcbopt = m; 1726 return (0); 1727 1728 bad: 1729 m_free(m); 1730 return (EINVAL); 1731 } 1732 1733 /* 1734 * XXX 1735 * The whole multicast option thing needs to be re-thought. 1736 * Several of these options are equally applicable to non-multicast 1737 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1738 * standard option (IP_TTL). 1739 */ 1740 1741 /* 1742 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1743 */ 1744 static struct ifnet * 1745 ip_multicast_if(struct in_addr *a, int *ifindexp) 1746 { 1747 int ifindex; 1748 struct ifnet *ifp; 1749 1750 if (ifindexp) 1751 *ifindexp = 0; 1752 if (ntohl(a->s_addr) >> 24 == 0) { 1753 ifindex = ntohl(a->s_addr) & 0xffffff; 1754 if (ifindex < 0 || if_index < ifindex) 1755 return NULL; 1756 ifp = ifindex2ifnet[ifindex]; 1757 if (ifindexp) 1758 *ifindexp = ifindex; 1759 } else { 1760 INADDR_TO_IFP(*a, ifp); 1761 } 1762 return ifp; 1763 } 1764 1765 /* 1766 * Set the IP multicast options in response to user setsockopt(). 1767 */ 1768 static int 1769 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1770 { 1771 int error = 0; 1772 int i; 1773 struct in_addr addr; 1774 struct ip_mreq mreq; 1775 struct ifnet *ifp; 1776 struct ip_moptions *imo = *imop; 1777 int ifindex; 1778 int s; 1779 1780 if (imo == NULL) { 1781 /* 1782 * No multicast option buffer attached to the pcb; 1783 * allocate one and initialize to default values. 1784 */ 1785 imo = malloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1786 1787 if (imo == NULL) 1788 return (ENOBUFS); 1789 *imop = imo; 1790 imo->imo_multicast_ifp = NULL; 1791 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1792 imo->imo_multicast_vif = -1; 1793 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1794 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1795 imo->imo_num_memberships = 0; 1796 } 1797 1798 switch (sopt->sopt_name) { 1799 /* store an index number for the vif you wanna use in the send */ 1800 case IP_MULTICAST_VIF: 1801 if (legal_vif_num == 0) { 1802 error = EOPNOTSUPP; 1803 break; 1804 } 1805 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1806 if (error) 1807 break; 1808 if (!legal_vif_num(i) && (i != -1)) { 1809 error = EINVAL; 1810 break; 1811 } 1812 imo->imo_multicast_vif = i; 1813 break; 1814 1815 case IP_MULTICAST_IF: 1816 /* 1817 * Select the interface for outgoing multicast packets. 1818 */ 1819 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1820 if (error) 1821 break; 1822 /* 1823 * INADDR_ANY is used to remove a previous selection. 1824 * When no interface is selected, a default one is 1825 * chosen every time a multicast packet is sent. 1826 */ 1827 if (addr.s_addr == INADDR_ANY) { 1828 imo->imo_multicast_ifp = NULL; 1829 break; 1830 } 1831 /* 1832 * The selected interface is identified by its local 1833 * IP address. Find the interface and confirm that 1834 * it supports multicasting. 1835 */ 1836 s = splimp(); 1837 ifp = ip_multicast_if(&addr, &ifindex); 1838 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1839 splx(s); 1840 error = EADDRNOTAVAIL; 1841 break; 1842 } 1843 imo->imo_multicast_ifp = ifp; 1844 if (ifindex) 1845 imo->imo_multicast_addr = addr; 1846 else 1847 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1848 splx(s); 1849 break; 1850 1851 case IP_MULTICAST_TTL: 1852 /* 1853 * Set the IP time-to-live for outgoing multicast packets. 1854 * The original multicast API required a char argument, 1855 * which is inconsistent with the rest of the socket API. 1856 * We allow either a char or an int. 1857 */ 1858 if (sopt->sopt_valsize == 1) { 1859 u_char ttl; 1860 error = sooptcopyin(sopt, &ttl, 1, 1); 1861 if (error) 1862 break; 1863 imo->imo_multicast_ttl = ttl; 1864 } else { 1865 u_int ttl; 1866 error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl); 1867 if (error) 1868 break; 1869 if (ttl > 255) 1870 error = EINVAL; 1871 else 1872 imo->imo_multicast_ttl = ttl; 1873 } 1874 break; 1875 1876 case IP_MULTICAST_LOOP: 1877 /* 1878 * Set the loopback flag for outgoing multicast packets. 1879 * Must be zero or one. The original multicast API required a 1880 * char argument, which is inconsistent with the rest 1881 * of the socket API. We allow either a char or an int. 1882 */ 1883 if (sopt->sopt_valsize == 1) { 1884 u_char loop; 1885 1886 error = sooptcopyin(sopt, &loop, 1, 1); 1887 if (error) 1888 break; 1889 imo->imo_multicast_loop = !!loop; 1890 } else { 1891 u_int loop; 1892 1893 error = sooptcopyin(sopt, &loop, sizeof loop, 1894 sizeof loop); 1895 if (error) 1896 break; 1897 imo->imo_multicast_loop = !!loop; 1898 } 1899 break; 1900 1901 case IP_ADD_MEMBERSHIP: 1902 /* 1903 * Add a multicast group membership. 1904 * Group must be a valid IP multicast address. 1905 */ 1906 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1907 if (error) 1908 break; 1909 1910 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1911 error = EINVAL; 1912 break; 1913 } 1914 s = splimp(); 1915 /* 1916 * If no interface address was provided, use the interface of 1917 * the route to the given multicast address. 1918 */ 1919 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1920 struct sockaddr_in dst; 1921 struct rtentry *rt; 1922 1923 bzero(&dst, sizeof(struct sockaddr_in)); 1924 dst.sin_len = sizeof(struct sockaddr_in); 1925 dst.sin_family = AF_INET; 1926 dst.sin_addr = mreq.imr_multiaddr; 1927 rt = rtlookup((struct sockaddr *)&dst); 1928 if (rt == NULL) { 1929 error = EADDRNOTAVAIL; 1930 splx(s); 1931 break; 1932 } 1933 --rt->rt_refcnt; 1934 ifp = rt->rt_ifp; 1935 } else { 1936 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1937 } 1938 1939 /* 1940 * See if we found an interface, and confirm that it 1941 * supports multicast. 1942 */ 1943 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1944 error = EADDRNOTAVAIL; 1945 splx(s); 1946 break; 1947 } 1948 /* 1949 * See if the membership already exists or if all the 1950 * membership slots are full. 1951 */ 1952 for (i = 0; i < imo->imo_num_memberships; ++i) { 1953 if (imo->imo_membership[i]->inm_ifp == ifp && 1954 imo->imo_membership[i]->inm_addr.s_addr 1955 == mreq.imr_multiaddr.s_addr) 1956 break; 1957 } 1958 if (i < imo->imo_num_memberships) { 1959 error = EADDRINUSE; 1960 splx(s); 1961 break; 1962 } 1963 if (i == IP_MAX_MEMBERSHIPS) { 1964 error = ETOOMANYREFS; 1965 splx(s); 1966 break; 1967 } 1968 /* 1969 * Everything looks good; add a new record to the multicast 1970 * address list for the given interface. 1971 */ 1972 if ((imo->imo_membership[i] = 1973 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1974 error = ENOBUFS; 1975 splx(s); 1976 break; 1977 } 1978 ++imo->imo_num_memberships; 1979 splx(s); 1980 break; 1981 1982 case IP_DROP_MEMBERSHIP: 1983 /* 1984 * Drop a multicast group membership. 1985 * Group must be a valid IP multicast address. 1986 */ 1987 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1988 if (error) 1989 break; 1990 1991 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1992 error = EINVAL; 1993 break; 1994 } 1995 1996 s = splimp(); 1997 /* 1998 * If an interface address was specified, get a pointer 1999 * to its ifnet structure. 2000 */ 2001 if (mreq.imr_interface.s_addr == INADDR_ANY) 2002 ifp = NULL; 2003 else { 2004 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2005 if (ifp == NULL) { 2006 error = EADDRNOTAVAIL; 2007 splx(s); 2008 break; 2009 } 2010 } 2011 /* 2012 * Find the membership in the membership array. 2013 */ 2014 for (i = 0; i < imo->imo_num_memberships; ++i) { 2015 if ((ifp == NULL || 2016 imo->imo_membership[i]->inm_ifp == ifp) && 2017 imo->imo_membership[i]->inm_addr.s_addr == 2018 mreq.imr_multiaddr.s_addr) 2019 break; 2020 } 2021 if (i == imo->imo_num_memberships) { 2022 error = EADDRNOTAVAIL; 2023 splx(s); 2024 break; 2025 } 2026 /* 2027 * Give up the multicast address record to which the 2028 * membership points. 2029 */ 2030 in_delmulti(imo->imo_membership[i]); 2031 /* 2032 * Remove the gap in the membership array. 2033 */ 2034 for (++i; i < imo->imo_num_memberships; ++i) 2035 imo->imo_membership[i-1] = imo->imo_membership[i]; 2036 --imo->imo_num_memberships; 2037 splx(s); 2038 break; 2039 2040 default: 2041 error = EOPNOTSUPP; 2042 break; 2043 } 2044 2045 /* 2046 * If all options have default values, no need to keep the mbuf. 2047 */ 2048 if (imo->imo_multicast_ifp == NULL && 2049 imo->imo_multicast_vif == -1 && 2050 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2051 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2052 imo->imo_num_memberships == 0) { 2053 free(*imop, M_IPMOPTS); 2054 *imop = NULL; 2055 } 2056 2057 return (error); 2058 } 2059 2060 /* 2061 * Return the IP multicast options in response to user getsockopt(). 2062 */ 2063 static int 2064 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2065 { 2066 struct in_addr addr; 2067 struct in_ifaddr *ia; 2068 int error, optval; 2069 u_char coptval; 2070 2071 error = 0; 2072 switch (sopt->sopt_name) { 2073 case IP_MULTICAST_VIF: 2074 if (imo != NULL) 2075 optval = imo->imo_multicast_vif; 2076 else 2077 optval = -1; 2078 error = sooptcopyout(sopt, &optval, sizeof optval); 2079 break; 2080 2081 case IP_MULTICAST_IF: 2082 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2083 addr.s_addr = INADDR_ANY; 2084 else if (imo->imo_multicast_addr.s_addr) { 2085 /* return the value user has set */ 2086 addr = imo->imo_multicast_addr; 2087 } else { 2088 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2089 addr.s_addr = (ia == NULL) ? INADDR_ANY 2090 : IA_SIN(ia)->sin_addr.s_addr; 2091 } 2092 error = sooptcopyout(sopt, &addr, sizeof addr); 2093 break; 2094 2095 case IP_MULTICAST_TTL: 2096 if (imo == NULL) 2097 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2098 else 2099 optval = coptval = imo->imo_multicast_ttl; 2100 if (sopt->sopt_valsize == 1) 2101 error = sooptcopyout(sopt, &coptval, 1); 2102 else 2103 error = sooptcopyout(sopt, &optval, sizeof optval); 2104 break; 2105 2106 case IP_MULTICAST_LOOP: 2107 if (imo == NULL) 2108 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2109 else 2110 optval = coptval = imo->imo_multicast_loop; 2111 if (sopt->sopt_valsize == 1) 2112 error = sooptcopyout(sopt, &coptval, 1); 2113 else 2114 error = sooptcopyout(sopt, &optval, sizeof optval); 2115 break; 2116 2117 default: 2118 error = ENOPROTOOPT; 2119 break; 2120 } 2121 return (error); 2122 } 2123 2124 /* 2125 * Discard the IP multicast options. 2126 */ 2127 void 2128 ip_freemoptions(struct ip_moptions *imo) 2129 { 2130 int i; 2131 2132 if (imo != NULL) { 2133 for (i = 0; i < imo->imo_num_memberships; ++i) 2134 in_delmulti(imo->imo_membership[i]); 2135 free(imo, M_IPMOPTS); 2136 } 2137 } 2138 2139 /* 2140 * Routine called from ip_output() to loop back a copy of an IP multicast 2141 * packet to the input queue of a specified interface. Note that this 2142 * calls the output routine of the loopback "driver", but with an interface 2143 * pointer that might NOT be a loopback interface -- evil, but easier than 2144 * replicating that code here. 2145 */ 2146 static void 2147 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2148 int hlen) 2149 { 2150 struct ip *ip; 2151 struct mbuf *copym; 2152 2153 copym = m_copypacket(m, MB_DONTWAIT); 2154 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2155 copym = m_pullup(copym, hlen); 2156 if (copym != NULL) { 2157 /* 2158 * if the checksum hasn't been computed, mark it as valid 2159 */ 2160 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2161 in_delayed_cksum(copym); 2162 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2163 copym->m_pkthdr.csum_flags |= 2164 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2165 copym->m_pkthdr.csum_data = 0xffff; 2166 } 2167 /* 2168 * We don't bother to fragment if the IP length is greater 2169 * than the interface's MTU. Can this possibly matter? 2170 */ 2171 ip = mtod(copym, struct ip *); 2172 ip->ip_len = htons(ip->ip_len); 2173 ip->ip_off = htons(ip->ip_off); 2174 ip->ip_sum = 0; 2175 if (ip->ip_vhl == IP_VHL_BORING) { 2176 ip->ip_sum = in_cksum_hdr(ip); 2177 } else { 2178 ip->ip_sum = in_cksum(copym, hlen); 2179 } 2180 /* 2181 * NB: 2182 * It's not clear whether there are any lingering 2183 * reentrancy problems in other areas which might 2184 * be exposed by using ip_input directly (in 2185 * particular, everything which modifies the packet 2186 * in-place). Yet another option is using the 2187 * protosw directly to deliver the looped back 2188 * packet. For the moment, we'll err on the side 2189 * of safety by using if_simloop(). 2190 */ 2191 #if 1 /* XXX */ 2192 if (dst->sin_family != AF_INET) { 2193 printf("ip_mloopback: bad address family %d\n", 2194 dst->sin_family); 2195 dst->sin_family = AF_INET; 2196 } 2197 #endif 2198 2199 #ifdef notdef 2200 copym->m_pkthdr.rcvif = ifp; 2201 ip_input(copym); 2202 #else 2203 if_simloop(ifp, copym, dst->sin_family, 0); 2204 #endif 2205 } 2206 } 2207