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 1.23 2004/12/21 02:54:15 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 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) { 158 switch(m0->_m_tag_id) { 159 default: 160 printf("ip_output: unrecognised MT_TAG tag %d\n", 161 m0->_m_tag_id); 162 break; 163 164 case PACKET_TAG_DUMMYNET: 165 /* 166 * the packet was already tagged, so part of the 167 * processing was already done, and we need to go down. 168 * Get parameters from the header. 169 */ 170 args.rule = ((struct dn_pkt *)m0)->rule; 171 opt = NULL ; 172 ro = & ( ((struct dn_pkt *)m0)->ro ) ; 173 imo = NULL ; 174 dst = ((struct dn_pkt *)m0)->dn_dst ; 175 ifp = ((struct dn_pkt *)m0)->ifp ; 176 flags = ((struct dn_pkt *)m0)->flags ; 177 break; 178 179 case PACKET_TAG_DIVERT: 180 args.divert_rule = (int)m0->m_data & 0xffff; 181 break; 182 183 case PACKET_TAG_IPFORWARD: 184 args.next_hop = (struct sockaddr_in *)m0->m_data; 185 break; 186 } 187 } 188 m = m0; 189 190 KASSERT(!m || (m->m_flags & M_PKTHDR), ("ip_output: no HDR")); 191 192 if (ro == NULL) { 193 ro = &iproute; 194 bzero(ro, sizeof(*ro)); 195 } 196 197 if (args.rule != NULL) { /* dummynet already saw us */ 198 ip = mtod(m, struct ip *); 199 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 200 if (ro->ro_rt) 201 ia = ifatoia(ro->ro_rt->rt_ifa); 202 goto sendit; 203 } 204 205 if (opt) { 206 len = 0; 207 m = ip_insertoptions(m, opt, &len); 208 if (len != 0) 209 hlen = len; 210 } 211 ip = mtod(m, struct ip *); 212 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 213 214 /* 215 * Fill in IP header. 216 */ 217 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 218 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 219 ip->ip_off &= IP_DF; 220 #ifdef RANDOM_IP_ID 221 ip->ip_id = ip_randomid(); 222 #else 223 ip->ip_id = htons(ip_id++); 224 #endif 225 ipstat.ips_localout++; 226 } else { 227 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 228 } 229 230 dst = (struct sockaddr_in *)&ro->ro_dst; 231 /* 232 * If there is a cached route, 233 * check that it is to the same destination 234 * and is still up. If not, free it and try again. 235 * The address family should also be checked in case of sharing the 236 * cache with IPv6. 237 */ 238 if (ro->ro_rt && 239 (!(ro->ro_rt->rt_flags & RTF_UP) || 240 dst->sin_family != AF_INET || 241 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 242 RTFREE(ro->ro_rt); 243 ro->ro_rt = (struct rtentry *)NULL; 244 } 245 if (ro->ro_rt == NULL) { 246 bzero(dst, sizeof(*dst)); 247 dst->sin_family = AF_INET; 248 dst->sin_len = sizeof(*dst); 249 dst->sin_addr = pkt_dst; 250 } 251 /* 252 * If routing to interface only, 253 * short circuit routing lookup. 254 */ 255 if (flags & IP_ROUTETOIF) { 256 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 257 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 258 ipstat.ips_noroute++; 259 error = ENETUNREACH; 260 goto bad; 261 } 262 ifp = ia->ia_ifp; 263 ip->ip_ttl = 1; 264 isbroadcast = in_broadcast(dst->sin_addr, ifp); 265 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 266 imo != NULL && imo->imo_multicast_ifp != NULL) { 267 /* 268 * Bypass the normal routing lookup for multicast 269 * packets if the interface is specified. 270 */ 271 ifp = imo->imo_multicast_ifp; 272 IFP_TO_IA(ifp, ia); 273 isbroadcast = 0; /* fool gcc */ 274 } else { 275 /* 276 * If this is the case, we probably don't want to allocate 277 * a protocol-cloned route since we didn't get one from the 278 * ULP. This lets TCP do its thing, while not burdening 279 * forwarding or ICMP with the overhead of cloning a route. 280 * Of course, we still want to do any cloning requested by 281 * the link layer, as this is probably required in all cases 282 * for correct operation (as it is for ARP). 283 */ 284 if (ro->ro_rt == NULL) 285 rtalloc_ign(ro, RTF_PRCLONING); 286 if (ro->ro_rt == NULL) { 287 ipstat.ips_noroute++; 288 error = EHOSTUNREACH; 289 goto bad; 290 } 291 ia = ifatoia(ro->ro_rt->rt_ifa); 292 ifp = ro->ro_rt->rt_ifp; 293 ro->ro_rt->rt_use++; 294 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 295 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 296 if (ro->ro_rt->rt_flags & RTF_HOST) 297 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 298 else 299 isbroadcast = in_broadcast(dst->sin_addr, ifp); 300 } 301 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 302 struct in_multi *inm; 303 304 m->m_flags |= M_MCAST; 305 /* 306 * IP destination address is multicast. Make sure "dst" 307 * still points to the address in "ro". (It may have been 308 * changed to point to a gateway address, above.) 309 */ 310 dst = (struct sockaddr_in *)&ro->ro_dst; 311 /* 312 * See if the caller provided any multicast options 313 */ 314 if (imo != NULL) { 315 ip->ip_ttl = imo->imo_multicast_ttl; 316 if (imo->imo_multicast_vif != -1) 317 ip->ip_src.s_addr = 318 ip_mcast_src ? 319 ip_mcast_src(imo->imo_multicast_vif) : 320 INADDR_ANY; 321 } else 322 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 323 /* 324 * Confirm that the outgoing interface supports multicast. 325 */ 326 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 327 if (!(ifp->if_flags & IFF_MULTICAST)) { 328 ipstat.ips_noroute++; 329 error = ENETUNREACH; 330 goto bad; 331 } 332 } 333 /* 334 * If source address not specified yet, use address 335 * of outgoing interface. 336 */ 337 if (ip->ip_src.s_addr == INADDR_ANY) { 338 /* Interface may have no addresses. */ 339 if (ia != NULL) 340 ip->ip_src = IA_SIN(ia)->sin_addr; 341 } 342 343 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 344 if (inm != NULL && 345 (imo == NULL || imo->imo_multicast_loop)) { 346 /* 347 * If we belong to the destination multicast group 348 * on the outgoing interface, and the caller did not 349 * forbid loopback, loop back a copy. 350 */ 351 ip_mloopback(ifp, m, dst, hlen); 352 } 353 else { 354 /* 355 * If we are acting as a multicast router, perform 356 * multicast forwarding as if the packet had just 357 * arrived on the interface to which we are about 358 * to send. The multicast forwarding function 359 * recursively calls this function, using the 360 * IP_FORWARDING flag to prevent infinite recursion. 361 * 362 * Multicasts that are looped back by ip_mloopback(), 363 * above, will be forwarded by the ip_input() routine, 364 * if necessary. 365 */ 366 if (ip_mrouter && !(flags & IP_FORWARDING)) { 367 /* 368 * If rsvp daemon is not running, do not 369 * set ip_moptions. This ensures that the packet 370 * is multicast and not just sent down one link 371 * as prescribed by rsvpd. 372 */ 373 if (!rsvp_on) 374 imo = NULL; 375 if (ip_mforward && 376 ip_mforward(ip, ifp, m, imo) != 0) { 377 m_freem(m); 378 goto done; 379 } 380 } 381 } 382 383 /* 384 * Multicasts with a time-to-live of zero may be looped- 385 * back, above, but must not be transmitted on a network. 386 * Also, multicasts addressed to the loopback interface 387 * are not sent -- the above call to ip_mloopback() will 388 * loop back a copy if this host actually belongs to the 389 * destination group on the loopback interface. 390 */ 391 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 392 m_freem(m); 393 goto done; 394 } 395 396 goto sendit; 397 } 398 #ifndef notdef 399 /* 400 * If the source address is not specified yet, use the address 401 * of the outoing interface. In case, keep note we did that, so 402 * if the the firewall changes the next-hop causing the output 403 * interface to change, we can fix that. 404 */ 405 if (ip->ip_src.s_addr == INADDR_ANY) { 406 /* Interface may have no addresses. */ 407 if (ia != NULL) { 408 ip->ip_src = IA_SIN(ia)->sin_addr; 409 src_was_INADDR_ANY = 1; 410 } 411 } 412 #endif /* notdef */ 413 /* 414 * Verify that we have any chance at all of being able to queue 415 * the packet or packet fragments 416 */ 417 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 418 ifp->if_snd.ifq_maxlen) { 419 error = ENOBUFS; 420 ipstat.ips_odropped++; 421 goto bad; 422 } 423 424 /* 425 * Look for broadcast address and 426 * verify user is allowed to send 427 * such a packet. 428 */ 429 if (isbroadcast) { 430 if (!(ifp->if_flags & IFF_BROADCAST)) { 431 error = EADDRNOTAVAIL; 432 goto bad; 433 } 434 if (!(flags & IP_ALLOWBROADCAST)) { 435 error = EACCES; 436 goto bad; 437 } 438 /* don't allow broadcast messages to be fragmented */ 439 if (ip->ip_len > ifp->if_mtu) { 440 error = EMSGSIZE; 441 goto bad; 442 } 443 m->m_flags |= M_BCAST; 444 } else { 445 m->m_flags &= ~M_BCAST; 446 } 447 448 sendit: 449 #ifdef IPSEC 450 /* get SP for this packet */ 451 if (so == NULL) 452 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 453 else 454 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 455 456 if (sp == NULL) { 457 ipsecstat.out_inval++; 458 goto bad; 459 } 460 461 error = 0; 462 463 /* check policy */ 464 switch (sp->policy) { 465 case IPSEC_POLICY_DISCARD: 466 /* 467 * This packet is just discarded. 468 */ 469 ipsecstat.out_polvio++; 470 goto bad; 471 472 case IPSEC_POLICY_BYPASS: 473 case IPSEC_POLICY_NONE: 474 /* no need to do IPsec. */ 475 goto skip_ipsec; 476 477 case IPSEC_POLICY_IPSEC: 478 if (sp->req == NULL) { 479 /* acquire a policy */ 480 error = key_spdacquire(sp); 481 goto bad; 482 } 483 break; 484 485 case IPSEC_POLICY_ENTRUST: 486 default: 487 printf("ip_output: Invalid policy found. %d\n", sp->policy); 488 } 489 { 490 struct ipsec_output_state state; 491 bzero(&state, sizeof(state)); 492 state.m = m; 493 if (flags & IP_ROUTETOIF) { 494 state.ro = &iproute; 495 bzero(&iproute, sizeof(iproute)); 496 } else 497 state.ro = ro; 498 state.dst = (struct sockaddr *)dst; 499 500 ip->ip_sum = 0; 501 502 /* 503 * XXX 504 * delayed checksums are not currently compatible with IPsec 505 */ 506 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 507 in_delayed_cksum(m); 508 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 509 } 510 511 ip->ip_len = htons(ip->ip_len); 512 ip->ip_off = htons(ip->ip_off); 513 514 error = ipsec4_output(&state, sp, flags); 515 516 m = state.m; 517 if (flags & IP_ROUTETOIF) { 518 /* 519 * if we have tunnel mode SA, we may need to ignore 520 * IP_ROUTETOIF. 521 */ 522 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 523 flags &= ~IP_ROUTETOIF; 524 ro = state.ro; 525 } 526 } else 527 ro = state.ro; 528 dst = (struct sockaddr_in *)state.dst; 529 if (error) { 530 /* mbuf is already reclaimed in ipsec4_output. */ 531 m0 = NULL; 532 switch (error) { 533 case EHOSTUNREACH: 534 case ENETUNREACH: 535 case EMSGSIZE: 536 case ENOBUFS: 537 case ENOMEM: 538 break; 539 default: 540 printf("ip4_output (ipsec): error code %d\n", error); 541 /*fall through*/ 542 case ENOENT: 543 /* don't show these error codes to the user */ 544 error = 0; 545 break; 546 } 547 goto bad; 548 } 549 } 550 551 /* be sure to update variables that are affected by ipsec4_output() */ 552 ip = mtod(m, struct ip *); 553 #ifdef _IP_VHL 554 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 555 #else 556 hlen = ip->ip_hl << 2; 557 #endif 558 if (ro->ro_rt == NULL) { 559 if (!(flags & IP_ROUTETOIF)) { 560 printf("ip_output: " 561 "can't update route after IPsec processing\n"); 562 error = EHOSTUNREACH; /*XXX*/ 563 goto bad; 564 } 565 } else { 566 ia = ifatoia(ro->ro_rt->rt_ifa); 567 ifp = ro->ro_rt->rt_ifp; 568 } 569 570 /* make it flipped, again. */ 571 ip->ip_len = ntohs(ip->ip_len); 572 ip->ip_off = ntohs(ip->ip_off); 573 skip_ipsec: 574 #endif /*IPSEC*/ 575 #ifdef FAST_IPSEC 576 /* 577 * Check the security policy (SP) for the packet and, if 578 * required, do IPsec-related processing. There are two 579 * cases here; the first time a packet is sent through 580 * it will be untagged and handled by ipsec4_checkpolicy. 581 * If the packet is resubmitted to ip_output (e.g. after 582 * AH, ESP, etc. processing), there will be a tag to bypass 583 * the lookup and related policy checking. 584 */ 585 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 586 s = splnet(); 587 if (mtag != NULL) { 588 tdbi = (struct tdb_ident *)(mtag + 1); 589 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 590 if (sp == NULL) 591 error = -EINVAL; /* force silent drop */ 592 m_tag_delete(m, mtag); 593 } else { 594 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 595 &error, inp); 596 } 597 /* 598 * There are four return cases: 599 * sp != NULL apply IPsec policy 600 * sp == NULL, error == 0 no IPsec handling needed 601 * sp == NULL, error == -EINVAL discard packet w/o error 602 * sp == NULL, error != 0 discard packet, report error 603 */ 604 if (sp != NULL) { 605 /* Loop detection, check if ipsec processing already done */ 606 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 607 for (mtag = m_tag_first(m); mtag != NULL; 608 mtag = m_tag_next(m, mtag)) { 609 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 610 continue; 611 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 612 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 613 continue; 614 /* 615 * Check if policy has an SA associated with it. 616 * This can happen when an SP has yet to acquire 617 * an SA; e.g. on first reference. If it occurs, 618 * then we let ipsec4_process_packet do its thing. 619 */ 620 if (sp->req->sav == NULL) 621 break; 622 tdbi = (struct tdb_ident *)(mtag + 1); 623 if (tdbi->spi == sp->req->sav->spi && 624 tdbi->proto == sp->req->sav->sah->saidx.proto && 625 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 626 sizeof (union sockaddr_union)) == 0) { 627 /* 628 * No IPsec processing is needed, free 629 * reference to SP. 630 * 631 * NB: null pointer to avoid free at 632 * done: below. 633 */ 634 KEY_FREESP(&sp), sp = NULL; 635 splx(s); 636 goto spd_done; 637 } 638 } 639 640 /* 641 * Do delayed checksums now because we send before 642 * this is done in the normal processing path. 643 */ 644 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 645 in_delayed_cksum(m); 646 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 647 } 648 649 ip->ip_len = htons(ip->ip_len); 650 ip->ip_off = htons(ip->ip_off); 651 652 /* NB: callee frees mbuf */ 653 error = ipsec4_process_packet(m, sp->req, flags, 0); 654 /* 655 * Preserve KAME behaviour: ENOENT can be returned 656 * when an SA acquire is in progress. Don't propagate 657 * this to user-level; it confuses applications. 658 * 659 * XXX this will go away when the SADB is redone. 660 */ 661 if (error == ENOENT) 662 error = 0; 663 splx(s); 664 goto done; 665 } else { 666 splx(s); 667 668 if (error != 0) { 669 /* 670 * Hack: -EINVAL is used to signal that a packet 671 * should be silently discarded. This is typically 672 * because we asked key management for an SA and 673 * it was delayed (e.g. kicked up to IKE). 674 */ 675 if (error == -EINVAL) 676 error = 0; 677 goto bad; 678 } else { 679 /* No IPsec processing for this packet. */ 680 } 681 #ifdef notyet 682 /* 683 * If deferred crypto processing is needed, check that 684 * the interface supports it. 685 */ 686 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 687 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 688 /* notify IPsec to do its own crypto */ 689 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 690 error = EHOSTUNREACH; 691 goto bad; 692 } 693 #endif 694 } 695 spd_done: 696 #endif /* FAST_IPSEC */ 697 /* 698 * IpHack's section. 699 * - Xlate: translate packet's addr/port (NAT). 700 * - Firewall: deny/allow/etc. 701 * - Wrap: fake packet's addr/port <unimpl.> 702 * - Encapsulate: put it in another IP and send out. <unimp.> 703 */ 704 705 /* 706 * Run through list of hooks for output packets. 707 */ 708 if (pfil_has_hooks(&inet_pfil_hook)) { 709 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 710 if (error != 0 || m == NULL) 711 goto done; 712 ip = mtod(m, struct ip *); 713 } 714 715 /* 716 * Check with the firewall... 717 * but not if we are already being fwd'd from a firewall. 718 */ 719 if (fw_enable && IPFW_LOADED && !args.next_hop) { 720 struct sockaddr_in *old = dst; 721 722 args.m = m; 723 args.next_hop = dst; 724 args.oif = ifp; 725 off = ip_fw_chk_ptr(&args); 726 m = args.m; 727 dst = args.next_hop; 728 729 /* 730 * On return we must do the following: 731 * m == NULL -> drop the pkt (old interface, deprecated) 732 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 733 * 1<=off<= 0xffff -> DIVERT 734 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 735 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 736 * dst != old -> IPFIREWALL_FORWARD 737 * off==0, dst==old -> accept 738 * If some of the above modules are not compiled in, then 739 * we should't have to check the corresponding condition 740 * (because the ipfw control socket should not accept 741 * unsupported rules), but better play safe and drop 742 * packets in case of doubt. 743 */ 744 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 745 if (m) 746 m_freem(m); 747 error = EACCES; 748 goto done; 749 } 750 ip = mtod(m, struct ip *); 751 if (off == 0 && dst == old) /* common case */ 752 goto pass; 753 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG)) { 754 /* 755 * pass the pkt to dummynet. Need to include 756 * pipe number, m, ifp, ro, dst because these are 757 * not recomputed in the next pass. 758 * All other parameters have been already used and 759 * so they are not needed anymore. 760 * XXX note: if the ifp or ro entry are deleted 761 * while a pkt is in dummynet, we are in trouble! 762 */ 763 args.ro = ro; 764 args.dst = dst; 765 args.flags = flags; 766 767 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 768 &args); 769 goto done; 770 } 771 #ifdef IPDIVERT 772 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) { 773 struct mbuf *clone = NULL; 774 775 /* Clone packet if we're doing a 'tee' */ 776 if ((off & IP_FW_PORT_TEE_FLAG)) 777 clone = m_dup(m, MB_DONTWAIT); 778 779 /* 780 * XXX 781 * delayed checksums are not currently compatible 782 * with divert sockets. 783 */ 784 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 785 in_delayed_cksum(m); 786 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 787 } 788 789 /* Restore packet header fields to original values */ 790 ip->ip_len = htons(ip->ip_len); 791 ip->ip_off = htons(ip->ip_off); 792 793 /* Deliver packet to divert input routine */ 794 divert_packet(m, 0, off & 0xffff, args.divert_rule); 795 796 /* If 'tee', continue with original packet */ 797 if (clone != NULL) { 798 m = clone; 799 ip = mtod(m, struct ip *); 800 goto pass; 801 } 802 goto done; 803 } 804 #endif 805 806 /* IPFIREWALL_FORWARD */ 807 /* 808 * Check dst to make sure it is directly reachable on the 809 * interface we previously thought it was. 810 * If it isn't (which may be likely in some situations) we have 811 * to re-route it (ie, find a route for the next-hop and the 812 * associated interface) and set them here. This is nested 813 * forwarding which in most cases is undesirable, except where 814 * such control is nigh impossible. So we do it here. 815 * And I'm babbling. 816 */ 817 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 818 #if 0 819 /* 820 * XXX To improve readability, this block should be 821 * changed into a function call as below: 822 */ 823 error = ip_ipforward(&m, &dst, &ifp); 824 if (error) 825 goto bad; 826 if (m == NULL) /* ip_input consumed the mbuf */ 827 goto done; 828 #else 829 struct in_ifaddr *ia; 830 831 /* 832 * XXX sro_fwd below is static, and a pointer 833 * to it gets passed to routines downstream. 834 * This could have surprisingly bad results in 835 * practice, because its content is overwritten 836 * by subsequent packets. 837 */ 838 /* There must be a better way to do this next line... */ 839 static struct route sro_fwd; 840 struct route *ro_fwd = &sro_fwd; 841 842 #if 0 843 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 844 dst->sin_addr, "\n"); 845 #endif 846 847 /* 848 * We need to figure out if we have been forwarded 849 * to a local socket. If so, then we should somehow 850 * "loop back" to ip_input, and get directed to the 851 * PCB as if we had received this packet. This is 852 * because it may be dificult to identify the packets 853 * you want to forward until they are being output 854 * and have selected an interface. (e.g. locally 855 * initiated packets) If we used the loopback inteface, 856 * we would not be able to control what happens 857 * as the packet runs through ip_input() as 858 * it is done through a ISR. 859 */ 860 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr), 861 ia_hash) { 862 /* 863 * If the addr to forward to is one 864 * of ours, we pretend to 865 * be the destination for this packet. 866 */ 867 if (IA_SIN(ia)->sin_addr.s_addr == 868 dst->sin_addr.s_addr) 869 break; 870 } 871 if (ia != NULL) { /* tell ip_input "dont filter" */ 872 struct m_hdr tag; 873 874 tag.mh_type = MT_TAG; 875 tag.mh_flags = PACKET_TAG_IPFORWARD; 876 tag.mh_data = (caddr_t)args.next_hop; 877 tag.mh_next = m; 878 879 if (m->m_pkthdr.rcvif == NULL) 880 m->m_pkthdr.rcvif = ifunit("lo0"); 881 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 882 m->m_pkthdr.csum_flags |= 883 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 884 m0->m_pkthdr.csum_data = 0xffff; 885 } 886 m->m_pkthdr.csum_flags |= 887 CSUM_IP_CHECKED | CSUM_IP_VALID; 888 ip->ip_len = htons(ip->ip_len); 889 ip->ip_off = htons(ip->ip_off); 890 ip_input((struct mbuf *)&tag); 891 goto done; 892 } 893 /* Some of the logic for this was nicked from above. 894 * 895 * This rewrites the cached route in a local PCB. 896 * Is this what we want to do? 897 */ 898 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 899 900 ro_fwd->ro_rt = NULL; 901 rtalloc_ign(ro_fwd, RTF_PRCLONING); 902 903 if (ro_fwd->ro_rt == NULL) { 904 ipstat.ips_noroute++; 905 error = EHOSTUNREACH; 906 goto bad; 907 } 908 909 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 910 ifp = ro_fwd->ro_rt->rt_ifp; 911 ro_fwd->ro_rt->rt_use++; 912 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 913 dst = (struct sockaddr_in *) 914 ro_fwd->ro_rt->rt_gateway; 915 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 916 isbroadcast = 917 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 918 else 919 isbroadcast = in_broadcast(dst->sin_addr, ifp); 920 if (ro->ro_rt) 921 RTFREE(ro->ro_rt); 922 ro->ro_rt = ro_fwd->ro_rt; 923 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 924 925 #endif /* ... block to be put into a function */ 926 /* 927 * If we added a default src ip earlier, 928 * which would have been gotten from the-then 929 * interface, do it again, from the new one. 930 */ 931 if (src_was_INADDR_ANY) 932 ip->ip_src = IA_SIN(ia)->sin_addr; 933 goto pass ; 934 } 935 936 /* 937 * if we get here, none of the above matches, and 938 * we have to drop the pkt 939 */ 940 m_freem(m); 941 error = EACCES; /* not sure this is the right error msg */ 942 goto done; 943 } 944 945 pass: 946 /* 127/8 must not appear on wire - RFC1122. */ 947 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 948 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 949 if (!(ifp->if_flags & IFF_LOOPBACK)) { 950 ipstat.ips_badaddr++; 951 error = EADDRNOTAVAIL; 952 goto bad; 953 } 954 } 955 956 m->m_pkthdr.csum_flags |= CSUM_IP; 957 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 958 if (sw_csum & CSUM_DELAY_DATA) { 959 in_delayed_cksum(m); 960 sw_csum &= ~CSUM_DELAY_DATA; 961 } 962 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 963 964 /* 965 * If small enough for interface, or the interface will take 966 * care of the fragmentation for us, can just send directly. 967 */ 968 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 969 !(ip->ip_off & IP_DF))) { 970 ip->ip_len = htons(ip->ip_len); 971 ip->ip_off = htons(ip->ip_off); 972 ip->ip_sum = 0; 973 if (sw_csum & CSUM_DELAY_IP) { 974 if (ip->ip_vhl == IP_VHL_BORING) { 975 ip->ip_sum = in_cksum_hdr(ip); 976 } else { 977 ip->ip_sum = in_cksum(m, hlen); 978 } 979 } 980 981 /* Record statistics for this interface address. */ 982 if (!(flags & IP_FORWARDING) && ia) { 983 ia->ia_ifa.if_opackets++; 984 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 985 } 986 987 #ifdef IPSEC 988 /* clean ipsec history once it goes out of the node */ 989 ipsec_delaux(m); 990 #endif 991 992 #ifdef MBUF_STRESS_TEST 993 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 994 struct mbuf *m1, *m2; 995 int length, tmp; 996 997 tmp = length = m->m_pkthdr.len; 998 999 while ((length -= mbuf_frag_size) >= 1) { 1000 m1 = m_split(m, length, MB_DONTWAIT); 1001 if (m1 == NULL) 1002 break; 1003 m1->m_flags &= ~M_PKTHDR; 1004 m2 = m; 1005 while (m2->m_next != NULL) 1006 m2 = m2->m_next; 1007 m2->m_next = m1; 1008 } 1009 m->m_pkthdr.len = tmp; 1010 } 1011 #endif 1012 error = (*ifp->if_output)(ifp, m, 1013 (struct sockaddr *)dst, ro->ro_rt); 1014 goto done; 1015 } 1016 1017 if (ip->ip_off & IP_DF) { 1018 error = EMSGSIZE; 1019 /* 1020 * This case can happen if the user changed the MTU 1021 * of an interface after enabling IP on it. Because 1022 * most netifs don't keep track of routes pointing to 1023 * them, there is no way for one to update all its 1024 * routes when the MTU is changed. 1025 */ 1026 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1027 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1028 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1029 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1030 } 1031 ipstat.ips_cantfrag++; 1032 goto bad; 1033 } 1034 1035 /* 1036 * Too large for interface; fragment if possible. If successful, 1037 * on return, m will point to a list of packets to be sent. 1038 */ 1039 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1040 if (error) 1041 goto bad; 1042 for (; m; m = m0) { 1043 m0 = m->m_nextpkt; 1044 m->m_nextpkt = NULL; 1045 #ifdef IPSEC 1046 /* clean ipsec history once it goes out of the node */ 1047 ipsec_delaux(m); 1048 #endif 1049 if (error == 0) { 1050 /* Record statistics for this interface address. */ 1051 if (ia != NULL) { 1052 ia->ia_ifa.if_opackets++; 1053 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1054 } 1055 1056 error = (*ifp->if_output)(ifp, m, 1057 (struct sockaddr *)dst, ro->ro_rt); 1058 } else 1059 m_freem(m); 1060 } 1061 1062 if (error == 0) 1063 ipstat.ips_fragmented++; 1064 1065 done: 1066 if (ro == &iproute && ro->ro_rt) { 1067 RTFREE(ro->ro_rt); 1068 ro->ro_rt = NULL; 1069 } 1070 #ifdef IPSEC 1071 if (sp != NULL) { 1072 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1073 printf("DP ip_output call free SP:%p\n", sp)); 1074 key_freesp(sp); 1075 } 1076 #endif 1077 #ifdef FAST_IPSEC 1078 if (sp != NULL) 1079 KEY_FREESP(&sp); 1080 #endif 1081 return (error); 1082 bad: 1083 m_freem(m); 1084 goto done; 1085 } 1086 1087 /* 1088 * Create a chain of fragments which fit the given mtu. m_frag points to the 1089 * mbuf to be fragmented; on return it points to the chain with the fragments. 1090 * Return 0 if no error. If error, m_frag may contain a partially built 1091 * chain of fragments that should be freed by the caller. 1092 * 1093 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1094 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1095 */ 1096 int 1097 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1098 u_long if_hwassist_flags, int sw_csum) 1099 { 1100 int error = 0; 1101 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1102 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1103 int off; 1104 struct mbuf *m0 = *m_frag; /* the original packet */ 1105 int firstlen; 1106 struct mbuf **mnext; 1107 int nfrags; 1108 1109 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1110 ipstat.ips_cantfrag++; 1111 return EMSGSIZE; 1112 } 1113 1114 /* 1115 * Must be able to put at least 8 bytes per fragment. 1116 */ 1117 if (len < 8) 1118 return EMSGSIZE; 1119 1120 /* 1121 * If the interface will not calculate checksums on 1122 * fragmented packets, then do it here. 1123 */ 1124 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1125 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1126 in_delayed_cksum(m0); 1127 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1128 } 1129 1130 if (len > PAGE_SIZE) { 1131 /* 1132 * Fragment large datagrams such that each segment 1133 * contains a multiple of PAGE_SIZE amount of data, 1134 * plus headers. This enables a receiver to perform 1135 * page-flipping zero-copy optimizations. 1136 * 1137 * XXX When does this help given that sender and receiver 1138 * could have different page sizes, and also mtu could 1139 * be less than the receiver's page size ? 1140 */ 1141 int newlen; 1142 struct mbuf *m; 1143 1144 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1145 off += m->m_len; 1146 1147 /* 1148 * firstlen (off - hlen) must be aligned on an 1149 * 8-byte boundary 1150 */ 1151 if (off < hlen) 1152 goto smart_frag_failure; 1153 off = ((off - hlen) & ~7) + hlen; 1154 newlen = (~PAGE_MASK) & mtu; 1155 if ((newlen + sizeof (struct ip)) > mtu) { 1156 /* we failed, go back the default */ 1157 smart_frag_failure: 1158 newlen = len; 1159 off = hlen + len; 1160 } 1161 len = newlen; 1162 1163 } else { 1164 off = hlen + len; 1165 } 1166 1167 firstlen = off - hlen; 1168 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1169 1170 /* 1171 * Loop through length of segment after first fragment, 1172 * make new header and copy data of each part and link onto chain. 1173 * Here, m0 is the original packet, m is the fragment being created. 1174 * The fragments are linked off the m_nextpkt of the original 1175 * packet, which after processing serves as the first fragment. 1176 */ 1177 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1178 struct ip *mhip; /* ip header on the fragment */ 1179 struct mbuf *m; 1180 int mhlen = sizeof (struct ip); 1181 1182 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1183 if (m == NULL) { 1184 error = ENOBUFS; 1185 ipstat.ips_odropped++; 1186 goto done; 1187 } 1188 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1189 /* 1190 * In the first mbuf, leave room for the link header, then 1191 * copy the original IP header including options. The payload 1192 * goes into an additional mbuf chain returned by m_copy(). 1193 */ 1194 m->m_data += max_linkhdr; 1195 mhip = mtod(m, struct ip *); 1196 *mhip = *ip; 1197 if (hlen > sizeof (struct ip)) { 1198 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1199 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1200 } 1201 m->m_len = mhlen; 1202 /* XXX do we need to add ip->ip_off below ? */ 1203 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1204 if (off + len >= ip->ip_len) { /* last fragment */ 1205 len = ip->ip_len - off; 1206 m->m_flags |= M_LASTFRAG; 1207 } else 1208 mhip->ip_off |= IP_MF; 1209 mhip->ip_len = htons((u_short)(len + mhlen)); 1210 m->m_next = m_copy(m0, off, len); 1211 if (m->m_next == NULL) { /* copy failed */ 1212 m_free(m); 1213 error = ENOBUFS; /* ??? */ 1214 ipstat.ips_odropped++; 1215 goto done; 1216 } 1217 m->m_pkthdr.len = mhlen + len; 1218 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1219 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1220 mhip->ip_off = htons(mhip->ip_off); 1221 mhip->ip_sum = 0; 1222 if (sw_csum & CSUM_DELAY_IP) 1223 mhip->ip_sum = in_cksum(m, mhlen); 1224 *mnext = m; 1225 mnext = &m->m_nextpkt; 1226 } 1227 ipstat.ips_ofragments += nfrags; 1228 1229 /* set first marker for fragment chain */ 1230 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1231 m0->m_pkthdr.csum_data = nfrags; 1232 1233 /* 1234 * Update first fragment by trimming what's been copied out 1235 * and updating header. 1236 */ 1237 m_adj(m0, hlen + firstlen - ip->ip_len); 1238 m0->m_pkthdr.len = hlen + firstlen; 1239 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1240 ip->ip_off |= IP_MF; 1241 ip->ip_off = htons(ip->ip_off); 1242 ip->ip_sum = 0; 1243 if (sw_csum & CSUM_DELAY_IP) 1244 ip->ip_sum = in_cksum(m0, hlen); 1245 1246 done: 1247 *m_frag = m0; 1248 return error; 1249 } 1250 1251 void 1252 in_delayed_cksum(struct mbuf *m) 1253 { 1254 struct ip *ip; 1255 u_short csum, offset; 1256 1257 ip = mtod(m, struct ip *); 1258 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1259 csum = in_cksum_skip(m, ip->ip_len, offset); 1260 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1261 csum = 0xffff; 1262 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1263 1264 if (offset + sizeof(u_short) > m->m_len) { 1265 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1266 m->m_len, offset, ip->ip_p); 1267 /* 1268 * XXX 1269 * this shouldn't happen, but if it does, the 1270 * correct behavior may be to insert the checksum 1271 * in the existing chain instead of rearranging it. 1272 */ 1273 m = m_pullup(m, offset + sizeof(u_short)); 1274 } 1275 *(u_short *)(m->m_data + offset) = csum; 1276 } 1277 1278 /* 1279 * Insert IP options into preformed packet. 1280 * Adjust IP destination as required for IP source routing, 1281 * as indicated by a non-zero in_addr at the start of the options. 1282 * 1283 * XXX This routine assumes that the packet has no options in place. 1284 */ 1285 static struct mbuf * 1286 ip_insertoptions(m, opt, phlen) 1287 struct mbuf *m; 1288 struct mbuf *opt; 1289 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(ip, jp) 1338 struct ip *ip, *jp; 1339 { 1340 u_char *cp, *dp; 1341 int opt, optlen, cnt; 1342 1343 cp = (u_char *)(ip + 1); 1344 dp = (u_char *)(jp + 1); 1345 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 1346 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1347 opt = cp[0]; 1348 if (opt == IPOPT_EOL) 1349 break; 1350 if (opt == IPOPT_NOP) { 1351 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1352 *dp++ = IPOPT_NOP; 1353 optlen = 1; 1354 continue; 1355 } 1356 1357 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1358 ("ip_optcopy: malformed ipv4 option")); 1359 optlen = cp[IPOPT_OLEN]; 1360 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1361 ("ip_optcopy: malformed ipv4 option")); 1362 1363 /* bogus lengths should have been caught by ip_dooptions */ 1364 if (optlen > cnt) 1365 optlen = cnt; 1366 if (IPOPT_COPIED(opt)) { 1367 bcopy(cp, dp, optlen); 1368 dp += optlen; 1369 } 1370 } 1371 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1372 *dp++ = IPOPT_EOL; 1373 return (optlen); 1374 } 1375 1376 /* 1377 * IP socket option processing. 1378 */ 1379 int 1380 ip_ctloutput(so, sopt) 1381 struct socket *so; 1382 struct sockopt *sopt; 1383 { 1384 struct inpcb *inp = sotoinpcb(so); 1385 int error, optval; 1386 1387 error = optval = 0; 1388 if (sopt->sopt_level != IPPROTO_IP) { 1389 return (EINVAL); 1390 } 1391 1392 switch (sopt->sopt_dir) { 1393 case SOPT_SET: 1394 switch (sopt->sopt_name) { 1395 case IP_OPTIONS: 1396 #ifdef notyet 1397 case IP_RETOPTS: 1398 #endif 1399 { 1400 struct mbuf *m; 1401 if (sopt->sopt_valsize > MLEN) { 1402 error = EMSGSIZE; 1403 break; 1404 } 1405 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1406 if (m == NULL) { 1407 error = ENOBUFS; 1408 break; 1409 } 1410 m->m_len = sopt->sopt_valsize; 1411 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1412 m->m_len); 1413 1414 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1415 m)); 1416 } 1417 1418 case IP_TOS: 1419 case IP_TTL: 1420 case IP_RECVOPTS: 1421 case IP_RECVRETOPTS: 1422 case IP_RECVDSTADDR: 1423 case IP_RECVIF: 1424 case IP_FAITH: 1425 error = sooptcopyin(sopt, &optval, sizeof optval, 1426 sizeof optval); 1427 if (error) 1428 break; 1429 1430 switch (sopt->sopt_name) { 1431 case IP_TOS: 1432 inp->inp_ip_tos = optval; 1433 break; 1434 1435 case IP_TTL: 1436 inp->inp_ip_ttl = optval; 1437 break; 1438 #define OPTSET(bit) \ 1439 if (optval) \ 1440 inp->inp_flags |= bit; \ 1441 else \ 1442 inp->inp_flags &= ~bit; 1443 1444 case IP_RECVOPTS: 1445 OPTSET(INP_RECVOPTS); 1446 break; 1447 1448 case IP_RECVRETOPTS: 1449 OPTSET(INP_RECVRETOPTS); 1450 break; 1451 1452 case IP_RECVDSTADDR: 1453 OPTSET(INP_RECVDSTADDR); 1454 break; 1455 1456 case IP_RECVIF: 1457 OPTSET(INP_RECVIF); 1458 break; 1459 1460 case IP_FAITH: 1461 OPTSET(INP_FAITH); 1462 break; 1463 } 1464 break; 1465 #undef OPTSET 1466 1467 case IP_MULTICAST_IF: 1468 case IP_MULTICAST_VIF: 1469 case IP_MULTICAST_TTL: 1470 case IP_MULTICAST_LOOP: 1471 case IP_ADD_MEMBERSHIP: 1472 case IP_DROP_MEMBERSHIP: 1473 error = ip_setmoptions(sopt, &inp->inp_moptions); 1474 break; 1475 1476 case IP_PORTRANGE: 1477 error = sooptcopyin(sopt, &optval, sizeof optval, 1478 sizeof optval); 1479 if (error) 1480 break; 1481 1482 switch (optval) { 1483 case IP_PORTRANGE_DEFAULT: 1484 inp->inp_flags &= ~(INP_LOWPORT); 1485 inp->inp_flags &= ~(INP_HIGHPORT); 1486 break; 1487 1488 case IP_PORTRANGE_HIGH: 1489 inp->inp_flags &= ~(INP_LOWPORT); 1490 inp->inp_flags |= INP_HIGHPORT; 1491 break; 1492 1493 case IP_PORTRANGE_LOW: 1494 inp->inp_flags &= ~(INP_HIGHPORT); 1495 inp->inp_flags |= INP_LOWPORT; 1496 break; 1497 1498 default: 1499 error = EINVAL; 1500 break; 1501 } 1502 break; 1503 1504 #if defined(IPSEC) || defined(FAST_IPSEC) 1505 case IP_IPSEC_POLICY: 1506 { 1507 caddr_t req; 1508 size_t len = 0; 1509 int priv; 1510 struct mbuf *m; 1511 int optname; 1512 1513 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1514 break; 1515 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1516 break; 1517 priv = (sopt->sopt_td != NULL && 1518 suser(sopt->sopt_td) != 0) ? 0 : 1; 1519 req = mtod(m, caddr_t); 1520 len = m->m_len; 1521 optname = sopt->sopt_name; 1522 error = ipsec4_set_policy(inp, optname, req, len, priv); 1523 m_freem(m); 1524 break; 1525 } 1526 #endif /*IPSEC*/ 1527 1528 default: 1529 error = ENOPROTOOPT; 1530 break; 1531 } 1532 break; 1533 1534 case SOPT_GET: 1535 switch (sopt->sopt_name) { 1536 case IP_OPTIONS: 1537 case IP_RETOPTS: 1538 if (inp->inp_options) 1539 error = sooptcopyout(sopt, 1540 mtod(inp->inp_options, 1541 char *), 1542 inp->inp_options->m_len); 1543 else 1544 sopt->sopt_valsize = 0; 1545 break; 1546 1547 case IP_TOS: 1548 case IP_TTL: 1549 case IP_RECVOPTS: 1550 case IP_RECVRETOPTS: 1551 case IP_RECVDSTADDR: 1552 case IP_RECVIF: 1553 case IP_PORTRANGE: 1554 case IP_FAITH: 1555 switch (sopt->sopt_name) { 1556 1557 case IP_TOS: 1558 optval = inp->inp_ip_tos; 1559 break; 1560 1561 case IP_TTL: 1562 optval = inp->inp_ip_ttl; 1563 break; 1564 1565 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1566 1567 case IP_RECVOPTS: 1568 optval = OPTBIT(INP_RECVOPTS); 1569 break; 1570 1571 case IP_RECVRETOPTS: 1572 optval = OPTBIT(INP_RECVRETOPTS); 1573 break; 1574 1575 case IP_RECVDSTADDR: 1576 optval = OPTBIT(INP_RECVDSTADDR); 1577 break; 1578 1579 case IP_RECVIF: 1580 optval = OPTBIT(INP_RECVIF); 1581 break; 1582 1583 case IP_PORTRANGE: 1584 if (inp->inp_flags & INP_HIGHPORT) 1585 optval = IP_PORTRANGE_HIGH; 1586 else if (inp->inp_flags & INP_LOWPORT) 1587 optval = IP_PORTRANGE_LOW; 1588 else 1589 optval = 0; 1590 break; 1591 1592 case IP_FAITH: 1593 optval = OPTBIT(INP_FAITH); 1594 break; 1595 } 1596 error = sooptcopyout(sopt, &optval, sizeof optval); 1597 break; 1598 1599 case IP_MULTICAST_IF: 1600 case IP_MULTICAST_VIF: 1601 case IP_MULTICAST_TTL: 1602 case IP_MULTICAST_LOOP: 1603 case IP_ADD_MEMBERSHIP: 1604 case IP_DROP_MEMBERSHIP: 1605 error = ip_getmoptions(sopt, inp->inp_moptions); 1606 break; 1607 1608 #if defined(IPSEC) || defined(FAST_IPSEC) 1609 case IP_IPSEC_POLICY: 1610 { 1611 struct mbuf *m = NULL; 1612 caddr_t req = NULL; 1613 size_t len = 0; 1614 1615 if (m != NULL) { 1616 req = mtod(m, caddr_t); 1617 len = m->m_len; 1618 } 1619 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1620 if (error == 0) 1621 error = soopt_mcopyout(sopt, m); /* XXX */ 1622 if (error == 0) 1623 m_freem(m); 1624 break; 1625 } 1626 #endif /*IPSEC*/ 1627 1628 default: 1629 error = ENOPROTOOPT; 1630 break; 1631 } 1632 break; 1633 } 1634 return (error); 1635 } 1636 1637 /* 1638 * Set up IP options in pcb for insertion in output packets. 1639 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1640 * with destination address if source routed. 1641 */ 1642 static int 1643 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1644 { 1645 int cnt, optlen; 1646 u_char *cp; 1647 u_char opt; 1648 1649 /* turn off any old options */ 1650 if (*pcbopt) 1651 m_free(*pcbopt); 1652 *pcbopt = 0; 1653 if (m == NULL || m->m_len == 0) { 1654 /* 1655 * Only turning off any previous options. 1656 */ 1657 if (m != NULL) 1658 m_free(m); 1659 return (0); 1660 } 1661 1662 if (m->m_len % sizeof(int32_t)) 1663 goto bad; 1664 /* 1665 * IP first-hop destination address will be stored before 1666 * actual options; move other options back 1667 * and clear it when none present. 1668 */ 1669 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1670 goto bad; 1671 cnt = m->m_len; 1672 m->m_len += sizeof(struct in_addr); 1673 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1674 ovbcopy(mtod(m, caddr_t), cp, cnt); 1675 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1676 1677 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1678 opt = cp[IPOPT_OPTVAL]; 1679 if (opt == IPOPT_EOL) 1680 break; 1681 if (opt == IPOPT_NOP) 1682 optlen = 1; 1683 else { 1684 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1685 goto bad; 1686 optlen = cp[IPOPT_OLEN]; 1687 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1688 goto bad; 1689 } 1690 switch (opt) { 1691 1692 default: 1693 break; 1694 1695 case IPOPT_LSRR: 1696 case IPOPT_SSRR: 1697 /* 1698 * user process specifies route as: 1699 * ->A->B->C->D 1700 * D must be our final destination (but we can't 1701 * check that since we may not have connected yet). 1702 * A is first hop destination, which doesn't appear in 1703 * actual IP option, but is stored before the options. 1704 */ 1705 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1706 goto bad; 1707 m->m_len -= sizeof(struct in_addr); 1708 cnt -= sizeof(struct in_addr); 1709 optlen -= sizeof(struct in_addr); 1710 cp[IPOPT_OLEN] = optlen; 1711 /* 1712 * Move first hop before start of options. 1713 */ 1714 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1715 sizeof(struct in_addr)); 1716 /* 1717 * Then copy rest of options back 1718 * to close up the deleted entry. 1719 */ 1720 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1721 &cp[IPOPT_OFFSET+1], 1722 cnt - (IPOPT_MINOFF - 1)); 1723 break; 1724 } 1725 } 1726 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1727 goto bad; 1728 *pcbopt = m; 1729 return (0); 1730 1731 bad: 1732 m_free(m); 1733 return (EINVAL); 1734 } 1735 1736 /* 1737 * XXX 1738 * The whole multicast option thing needs to be re-thought. 1739 * Several of these options are equally applicable to non-multicast 1740 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1741 * standard option (IP_TTL). 1742 */ 1743 1744 /* 1745 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1746 */ 1747 static struct ifnet * 1748 ip_multicast_if(struct in_addr *a, int *ifindexp) 1749 { 1750 int ifindex; 1751 struct ifnet *ifp; 1752 1753 if (ifindexp) 1754 *ifindexp = 0; 1755 if (ntohl(a->s_addr) >> 24 == 0) { 1756 ifindex = ntohl(a->s_addr) & 0xffffff; 1757 if (ifindex < 0 || if_index < ifindex) 1758 return NULL; 1759 ifp = ifindex2ifnet[ifindex]; 1760 if (ifindexp) 1761 *ifindexp = ifindex; 1762 } else { 1763 INADDR_TO_IFP(*a, ifp); 1764 } 1765 return ifp; 1766 } 1767 1768 /* 1769 * Set the IP multicast options in response to user setsockopt(). 1770 */ 1771 static int 1772 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1773 { 1774 int error = 0; 1775 int i; 1776 struct in_addr addr; 1777 struct ip_mreq mreq; 1778 struct ifnet *ifp; 1779 struct ip_moptions *imo = *imop; 1780 struct route ro; 1781 struct sockaddr_in *dst; 1782 int ifindex; 1783 int s; 1784 1785 if (imo == NULL) { 1786 /* 1787 * No multicast option buffer attached to the pcb; 1788 * allocate one and initialize to default values. 1789 */ 1790 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1791 M_WAITOK); 1792 1793 if (imo == NULL) 1794 return (ENOBUFS); 1795 *imop = imo; 1796 imo->imo_multicast_ifp = NULL; 1797 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1798 imo->imo_multicast_vif = -1; 1799 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1800 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1801 imo->imo_num_memberships = 0; 1802 } 1803 1804 switch (sopt->sopt_name) { 1805 /* store an index number for the vif you wanna use in the send */ 1806 case IP_MULTICAST_VIF: 1807 if (legal_vif_num == 0) { 1808 error = EOPNOTSUPP; 1809 break; 1810 } 1811 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1812 if (error) 1813 break; 1814 if (!legal_vif_num(i) && (i != -1)) { 1815 error = EINVAL; 1816 break; 1817 } 1818 imo->imo_multicast_vif = i; 1819 break; 1820 1821 case IP_MULTICAST_IF: 1822 /* 1823 * Select the interface for outgoing multicast packets. 1824 */ 1825 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1826 if (error) 1827 break; 1828 /* 1829 * INADDR_ANY is used to remove a previous selection. 1830 * When no interface is selected, a default one is 1831 * chosen every time a multicast packet is sent. 1832 */ 1833 if (addr.s_addr == INADDR_ANY) { 1834 imo->imo_multicast_ifp = NULL; 1835 break; 1836 } 1837 /* 1838 * The selected interface is identified by its local 1839 * IP address. Find the interface and confirm that 1840 * it supports multicasting. 1841 */ 1842 s = splimp(); 1843 ifp = ip_multicast_if(&addr, &ifindex); 1844 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1845 splx(s); 1846 error = EADDRNOTAVAIL; 1847 break; 1848 } 1849 imo->imo_multicast_ifp = ifp; 1850 if (ifindex) 1851 imo->imo_multicast_addr = addr; 1852 else 1853 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1854 splx(s); 1855 break; 1856 1857 case IP_MULTICAST_TTL: 1858 /* 1859 * Set the IP time-to-live for outgoing multicast packets. 1860 * The original multicast API required a char argument, 1861 * which is inconsistent with the rest of the socket API. 1862 * We allow either a char or an int. 1863 */ 1864 if (sopt->sopt_valsize == 1) { 1865 u_char ttl; 1866 error = sooptcopyin(sopt, &ttl, 1, 1); 1867 if (error) 1868 break; 1869 imo->imo_multicast_ttl = ttl; 1870 } else { 1871 u_int ttl; 1872 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1873 sizeof ttl); 1874 if (error) 1875 break; 1876 if (ttl > 255) 1877 error = EINVAL; 1878 else 1879 imo->imo_multicast_ttl = ttl; 1880 } 1881 break; 1882 1883 case IP_MULTICAST_LOOP: 1884 /* 1885 * Set the loopback flag for outgoing multicast packets. 1886 * Must be zero or one. The original multicast API required a 1887 * char argument, which is inconsistent with the rest 1888 * of the socket API. We allow either a char or an int. 1889 */ 1890 if (sopt->sopt_valsize == 1) { 1891 u_char loop; 1892 error = sooptcopyin(sopt, &loop, 1, 1); 1893 if (error) 1894 break; 1895 imo->imo_multicast_loop = !!loop; 1896 } else { 1897 u_int loop; 1898 error = sooptcopyin(sopt, &loop, sizeof loop, 1899 sizeof loop); 1900 if (error) 1901 break; 1902 imo->imo_multicast_loop = !!loop; 1903 } 1904 break; 1905 1906 case IP_ADD_MEMBERSHIP: 1907 /* 1908 * Add a multicast group membership. 1909 * Group must be a valid IP multicast address. 1910 */ 1911 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1912 if (error) 1913 break; 1914 1915 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1916 error = EINVAL; 1917 break; 1918 } 1919 s = splimp(); 1920 /* 1921 * If no interface address was provided, use the interface of 1922 * the route to the given multicast address. 1923 */ 1924 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1925 bzero(&ro, sizeof(ro)); 1926 dst = (struct sockaddr_in *)&ro.ro_dst; 1927 dst->sin_len = sizeof(*dst); 1928 dst->sin_family = AF_INET; 1929 dst->sin_addr = mreq.imr_multiaddr; 1930 rtalloc(&ro); 1931 if (ro.ro_rt == NULL) { 1932 error = EADDRNOTAVAIL; 1933 splx(s); 1934 break; 1935 } 1936 ifp = ro.ro_rt->rt_ifp; 1937 rtfree(ro.ro_rt); 1938 } 1939 else { 1940 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1941 } 1942 1943 /* 1944 * See if we found an interface, and confirm that it 1945 * supports multicast. 1946 */ 1947 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1948 error = EADDRNOTAVAIL; 1949 splx(s); 1950 break; 1951 } 1952 /* 1953 * See if the membership already exists or if all the 1954 * membership slots are full. 1955 */ 1956 for (i = 0; i < imo->imo_num_memberships; ++i) { 1957 if (imo->imo_membership[i]->inm_ifp == ifp && 1958 imo->imo_membership[i]->inm_addr.s_addr 1959 == mreq.imr_multiaddr.s_addr) 1960 break; 1961 } 1962 if (i < imo->imo_num_memberships) { 1963 error = EADDRINUSE; 1964 splx(s); 1965 break; 1966 } 1967 if (i == IP_MAX_MEMBERSHIPS) { 1968 error = ETOOMANYREFS; 1969 splx(s); 1970 break; 1971 } 1972 /* 1973 * Everything looks good; add a new record to the multicast 1974 * address list for the given interface. 1975 */ 1976 if ((imo->imo_membership[i] = 1977 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1978 error = ENOBUFS; 1979 splx(s); 1980 break; 1981 } 1982 ++imo->imo_num_memberships; 1983 splx(s); 1984 break; 1985 1986 case IP_DROP_MEMBERSHIP: 1987 /* 1988 * Drop a multicast group membership. 1989 * Group must be a valid IP multicast address. 1990 */ 1991 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1992 if (error) 1993 break; 1994 1995 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1996 error = EINVAL; 1997 break; 1998 } 1999 2000 s = splimp(); 2001 /* 2002 * If an interface address was specified, get a pointer 2003 * to its ifnet structure. 2004 */ 2005 if (mreq.imr_interface.s_addr == INADDR_ANY) 2006 ifp = NULL; 2007 else { 2008 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2009 if (ifp == NULL) { 2010 error = EADDRNOTAVAIL; 2011 splx(s); 2012 break; 2013 } 2014 } 2015 /* 2016 * Find the membership in the membership array. 2017 */ 2018 for (i = 0; i < imo->imo_num_memberships; ++i) { 2019 if ((ifp == NULL || 2020 imo->imo_membership[i]->inm_ifp == ifp) && 2021 imo->imo_membership[i]->inm_addr.s_addr == 2022 mreq.imr_multiaddr.s_addr) 2023 break; 2024 } 2025 if (i == imo->imo_num_memberships) { 2026 error = EADDRNOTAVAIL; 2027 splx(s); 2028 break; 2029 } 2030 /* 2031 * Give up the multicast address record to which the 2032 * membership points. 2033 */ 2034 in_delmulti(imo->imo_membership[i]); 2035 /* 2036 * Remove the gap in the membership array. 2037 */ 2038 for (++i; i < imo->imo_num_memberships; ++i) 2039 imo->imo_membership[i-1] = imo->imo_membership[i]; 2040 --imo->imo_num_memberships; 2041 splx(s); 2042 break; 2043 2044 default: 2045 error = EOPNOTSUPP; 2046 break; 2047 } 2048 2049 /* 2050 * If all options have default values, no need to keep the mbuf. 2051 */ 2052 if (imo->imo_multicast_ifp == NULL && 2053 imo->imo_multicast_vif == -1 && 2054 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2055 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2056 imo->imo_num_memberships == 0) { 2057 free(*imop, M_IPMOPTS); 2058 *imop = NULL; 2059 } 2060 2061 return (error); 2062 } 2063 2064 /* 2065 * Return the IP multicast options in response to user getsockopt(). 2066 */ 2067 static int 2068 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2069 { 2070 struct in_addr addr; 2071 struct in_ifaddr *ia; 2072 int error, optval; 2073 u_char coptval; 2074 2075 error = 0; 2076 switch (sopt->sopt_name) { 2077 case IP_MULTICAST_VIF: 2078 if (imo != NULL) 2079 optval = imo->imo_multicast_vif; 2080 else 2081 optval = -1; 2082 error = sooptcopyout(sopt, &optval, sizeof optval); 2083 break; 2084 2085 case IP_MULTICAST_IF: 2086 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2087 addr.s_addr = INADDR_ANY; 2088 else if (imo->imo_multicast_addr.s_addr) { 2089 /* return the value user has set */ 2090 addr = imo->imo_multicast_addr; 2091 } else { 2092 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2093 addr.s_addr = (ia == NULL) ? INADDR_ANY 2094 : IA_SIN(ia)->sin_addr.s_addr; 2095 } 2096 error = sooptcopyout(sopt, &addr, sizeof addr); 2097 break; 2098 2099 case IP_MULTICAST_TTL: 2100 if (imo == NULL) 2101 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2102 else 2103 optval = coptval = imo->imo_multicast_ttl; 2104 if (sopt->sopt_valsize == 1) 2105 error = sooptcopyout(sopt, &coptval, 1); 2106 else 2107 error = sooptcopyout(sopt, &optval, sizeof optval); 2108 break; 2109 2110 case IP_MULTICAST_LOOP: 2111 if (imo == NULL) 2112 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2113 else 2114 optval = coptval = imo->imo_multicast_loop; 2115 if (sopt->sopt_valsize == 1) 2116 error = sooptcopyout(sopt, &coptval, 1); 2117 else 2118 error = sooptcopyout(sopt, &optval, sizeof optval); 2119 break; 2120 2121 default: 2122 error = ENOPROTOOPT; 2123 break; 2124 } 2125 return (error); 2126 } 2127 2128 /* 2129 * Discard the IP multicast options. 2130 */ 2131 void 2132 ip_freemoptions(struct ip_moptions *imo) 2133 { 2134 int i; 2135 2136 if (imo != NULL) { 2137 for (i = 0; i < imo->imo_num_memberships; ++i) 2138 in_delmulti(imo->imo_membership[i]); 2139 free(imo, M_IPMOPTS); 2140 } 2141 } 2142 2143 /* 2144 * Routine called from ip_output() to loop back a copy of an IP multicast 2145 * packet to the input queue of a specified interface. Note that this 2146 * calls the output routine of the loopback "driver", but with an interface 2147 * pointer that might NOT be a loopback interface -- evil, but easier than 2148 * replicating that code here. 2149 */ 2150 static void 2151 ip_mloopback(ifp, m, dst, hlen) 2152 struct ifnet *ifp; 2153 struct mbuf *m; 2154 struct sockaddr_in *dst; 2155 int hlen; 2156 { 2157 struct ip *ip; 2158 struct mbuf *copym; 2159 2160 copym = m_copypacket(m, MB_DONTWAIT); 2161 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2162 copym = m_pullup(copym, hlen); 2163 if (copym != NULL) { 2164 /* 2165 * if the checksum hasn't been computed, mark it as valid 2166 */ 2167 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2168 in_delayed_cksum(copym); 2169 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2170 copym->m_pkthdr.csum_flags |= 2171 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2172 copym->m_pkthdr.csum_data = 0xffff; 2173 } 2174 /* 2175 * We don't bother to fragment if the IP length is greater 2176 * than the interface's MTU. Can this possibly matter? 2177 */ 2178 ip = mtod(copym, struct ip *); 2179 ip->ip_len = htons(ip->ip_len); 2180 ip->ip_off = htons(ip->ip_off); 2181 ip->ip_sum = 0; 2182 if (ip->ip_vhl == IP_VHL_BORING) { 2183 ip->ip_sum = in_cksum_hdr(ip); 2184 } else { 2185 ip->ip_sum = in_cksum(copym, hlen); 2186 } 2187 /* 2188 * NB: 2189 * It's not clear whether there are any lingering 2190 * reentrancy problems in other areas which might 2191 * be exposed by using ip_input directly (in 2192 * particular, everything which modifies the packet 2193 * in-place). Yet another option is using the 2194 * protosw directly to deliver the looped back 2195 * packet. For the moment, we'll err on the side 2196 * of safety by using if_simloop(). 2197 */ 2198 #if 1 /* XXX */ 2199 if (dst->sin_family != AF_INET) { 2200 printf("ip_mloopback: bad address family %d\n", 2201 dst->sin_family); 2202 dst->sin_family = AF_INET; 2203 } 2204 #endif 2205 2206 #ifdef notdef 2207 copym->m_pkthdr.rcvif = ifp; 2208 ip_input(copym); 2209 #else 2210 if_simloop(ifp, copym, dst->sin_family, 0); 2211 #endif 2212 } 2213 } 2214