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 1.31 2005/06/17 19:12:20 dillon 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/thread2.h> 55 #include <sys/in_cksum.h> 56 57 #include <net/if.h> 58 #include <net/netisr.h> 59 #include <net/pfil.h> 60 #include <net/route.h> 61 62 #include <netinet/in.h> 63 #include <netinet/in_systm.h> 64 #include <netinet/ip.h> 65 #include <netinet/in_pcb.h> 66 #include <netinet/in_var.h> 67 #include <netinet/ip_var.h> 68 69 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 70 71 #ifdef IPSEC 72 #include <netinet6/ipsec.h> 73 #include <netproto/key/key.h> 74 #ifdef IPSEC_DEBUG 75 #include <netproto/key/key_debug.h> 76 #else 77 #define KEYDEBUG(lev,arg) 78 #endif 79 #endif /*IPSEC*/ 80 81 #ifdef FAST_IPSEC 82 #include <netproto/ipsec/ipsec.h> 83 #include <netproto/ipsec/xform.h> 84 #include <netproto/ipsec/key.h> 85 #endif /*FAST_IPSEC*/ 86 87 #include <net/ipfw/ip_fw.h> 88 #include <net/dummynet/ip_dummynet.h> 89 90 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 91 x, (ntohl(a.s_addr)>>24)&0xFF,\ 92 (ntohl(a.s_addr)>>16)&0xFF,\ 93 (ntohl(a.s_addr)>>8)&0xFF,\ 94 (ntohl(a.s_addr))&0xFF, y); 95 96 u_short ip_id; 97 98 #ifdef MBUF_STRESS_TEST 99 int mbuf_frag_size = 0; 100 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 101 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 102 #endif 103 104 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 105 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 106 static void ip_mloopback 107 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 108 static int ip_getmoptions 109 (struct sockopt *, struct ip_moptions *); 110 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 111 static int ip_setmoptions 112 (struct sockopt *, struct ip_moptions **); 113 114 int ip_optcopy(struct ip *, struct ip *); 115 116 117 extern struct protosw inetsw[]; 118 119 /* 120 * IP output. The packet in mbuf chain m contains a skeletal IP 121 * header (with len, off, ttl, proto, tos, src, dst). 122 * The mbuf chain containing the packet will be freed. 123 * The mbuf opt, if present, will not be freed. 124 */ 125 int 126 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 127 int flags, struct ip_moptions *imo, struct inpcb *inp) 128 { 129 struct ip *ip; 130 struct ifnet *ifp = NULL; /* keep compiler happy */ 131 struct mbuf *m; 132 int hlen = sizeof(struct ip); 133 int len, off, error = 0; 134 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 135 struct in_ifaddr *ia = NULL; 136 int isbroadcast, sw_csum; 137 struct in_addr pkt_dst; 138 struct route iproute; 139 #ifdef IPSEC 140 struct secpolicy *sp = NULL; 141 struct socket *so = inp ? inp->inp_socket : NULL; 142 #endif 143 #ifdef FAST_IPSEC 144 struct m_tag *mtag; 145 struct secpolicy *sp = NULL; 146 struct tdb_ident *tdbi; 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; 154 155 /* Grab info from MT_TAG mbufs prepended to the chain. */ 156 while (m0 != NULL && m0->m_type == MT_TAG) { 157 switch(m0->_m_tag_id) { 158 case PACKET_TAG_DUMMYNET: 159 /* 160 * the packet was already tagged, so part of the 161 * processing was already done, and we need to go down. 162 * Get parameters from the header. 163 */ 164 args.rule = ((struct dn_pkt *)m0)->rule; 165 opt = NULL ; 166 ro = &((struct dn_pkt *)m0)->ro; 167 imo = NULL ; 168 dst = ((struct dn_pkt *)m0)->dn_dst ; 169 ifp = ((struct dn_pkt *)m0)->ifp ; 170 flags = ((struct dn_pkt *)m0)->flags ; 171 break; 172 case PACKET_TAG_IPFORWARD: 173 args.next_hop = (struct sockaddr_in *)m0->m_data; 174 break; 175 default: 176 printf("ip_output: unrecognised MT_TAG tag %d\n", 177 m0->_m_tag_id); 178 break; 179 } 180 m0 = m0->m_next; 181 } 182 m = m0; 183 KASSERT(m != NULL && (m->m_flags & M_PKTHDR), ("ip_output: no HDR")); 184 185 if (ro == NULL) { 186 ro = &iproute; 187 bzero(ro, sizeof *ro); 188 } 189 190 if (args.rule != NULL) { /* dummynet already saw us */ 191 ip = mtod(m, struct ip *); 192 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 193 if (ro->ro_rt) 194 ia = ifatoia(ro->ro_rt->rt_ifa); 195 goto sendit; 196 } 197 198 if (opt) { 199 len = 0; 200 m = ip_insertoptions(m, opt, &len); 201 if (len != 0) 202 hlen = len; 203 } 204 ip = mtod(m, struct ip *); 205 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 206 207 /* 208 * Fill in IP header. 209 */ 210 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 211 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 212 ip->ip_off &= IP_DF; 213 #ifdef RANDOM_IP_ID 214 ip->ip_id = ip_randomid(); 215 #else 216 ip->ip_id = htons(ip_id++); 217 #endif 218 ipstat.ips_localout++; 219 } else { 220 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 221 } 222 223 dst = (struct sockaddr_in *)&ro->ro_dst; 224 /* 225 * If there is a cached route, 226 * check that it is to the same destination 227 * and is still up. If not, free it and try again. 228 * The address family should also be checked in case of sharing the 229 * cache with IPv6. 230 */ 231 if (ro->ro_rt && 232 (!(ro->ro_rt->rt_flags & RTF_UP) || 233 dst->sin_family != AF_INET || 234 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 235 rtfree(ro->ro_rt); 236 ro->ro_rt = (struct rtentry *)NULL; 237 } 238 if (ro->ro_rt == NULL) { 239 bzero(dst, sizeof *dst); 240 dst->sin_family = AF_INET; 241 dst->sin_len = sizeof *dst; 242 dst->sin_addr = pkt_dst; 243 } 244 /* 245 * If routing to interface only, 246 * short circuit routing lookup. 247 */ 248 if (flags & IP_ROUTETOIF) { 249 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 250 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 251 ipstat.ips_noroute++; 252 error = ENETUNREACH; 253 goto bad; 254 } 255 ifp = ia->ia_ifp; 256 ip->ip_ttl = 1; 257 isbroadcast = in_broadcast(dst->sin_addr, ifp); 258 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 259 imo != NULL && imo->imo_multicast_ifp != NULL) { 260 /* 261 * Bypass the normal routing lookup for multicast 262 * packets if the interface is specified. 263 */ 264 ifp = imo->imo_multicast_ifp; 265 IFP_TO_IA(ifp, ia); 266 isbroadcast = 0; /* fool gcc */ 267 } else { 268 /* 269 * If this is the case, we probably don't want to allocate 270 * a protocol-cloned route since we didn't get one from the 271 * ULP. This lets TCP do its thing, while not burdening 272 * forwarding or ICMP with the overhead of cloning a route. 273 * Of course, we still want to do any cloning requested by 274 * the link layer, as this is probably required in all cases 275 * for correct operation (as it is for ARP). 276 */ 277 if (ro->ro_rt == NULL) 278 rtalloc_ign(ro, RTF_PRCLONING); 279 if (ro->ro_rt == NULL) { 280 ipstat.ips_noroute++; 281 error = EHOSTUNREACH; 282 goto bad; 283 } 284 ia = ifatoia(ro->ro_rt->rt_ifa); 285 ifp = ro->ro_rt->rt_ifp; 286 ro->ro_rt->rt_use++; 287 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 288 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 289 if (ro->ro_rt->rt_flags & RTF_HOST) 290 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 291 else 292 isbroadcast = in_broadcast(dst->sin_addr, ifp); 293 } 294 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 295 struct in_multi *inm; 296 297 m->m_flags |= M_MCAST; 298 /* 299 * IP destination address is multicast. Make sure "dst" 300 * still points to the address in "ro". (It may have been 301 * changed to point to a gateway address, above.) 302 */ 303 dst = (struct sockaddr_in *)&ro->ro_dst; 304 /* 305 * See if the caller provided any multicast options 306 */ 307 if (imo != NULL) { 308 ip->ip_ttl = imo->imo_multicast_ttl; 309 if (imo->imo_multicast_vif != -1) 310 ip->ip_src.s_addr = 311 ip_mcast_src ? 312 ip_mcast_src(imo->imo_multicast_vif) : 313 INADDR_ANY; 314 } else 315 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 316 /* 317 * Confirm that the outgoing interface supports multicast. 318 */ 319 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 320 if (!(ifp->if_flags & IFF_MULTICAST)) { 321 ipstat.ips_noroute++; 322 error = ENETUNREACH; 323 goto bad; 324 } 325 } 326 /* 327 * If source address not specified yet, use address 328 * of outgoing interface. 329 */ 330 if (ip->ip_src.s_addr == INADDR_ANY) { 331 /* Interface may have no addresses. */ 332 if (ia != NULL) 333 ip->ip_src = IA_SIN(ia)->sin_addr; 334 } 335 336 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 337 if (inm != NULL && 338 (imo == NULL || imo->imo_multicast_loop)) { 339 /* 340 * If we belong to the destination multicast group 341 * on the outgoing interface, and the caller did not 342 * forbid loopback, loop back a copy. 343 */ 344 ip_mloopback(ifp, m, dst, hlen); 345 } 346 else { 347 /* 348 * If we are acting as a multicast router, perform 349 * multicast forwarding as if the packet had just 350 * arrived on the interface to which we are about 351 * to send. The multicast forwarding function 352 * recursively calls this function, using the 353 * IP_FORWARDING flag to prevent infinite recursion. 354 * 355 * Multicasts that are looped back by ip_mloopback(), 356 * above, will be forwarded by the ip_input() routine, 357 * if necessary. 358 */ 359 if (ip_mrouter && !(flags & IP_FORWARDING)) { 360 /* 361 * If rsvp daemon is not running, do not 362 * set ip_moptions. This ensures that the packet 363 * is multicast and not just sent down one link 364 * as prescribed by rsvpd. 365 */ 366 if (!rsvp_on) 367 imo = NULL; 368 if (ip_mforward && 369 ip_mforward(ip, ifp, m, imo) != 0) { 370 m_freem(m); 371 goto done; 372 } 373 } 374 } 375 376 /* 377 * Multicasts with a time-to-live of zero may be looped- 378 * back, above, but must not be transmitted on a network. 379 * Also, multicasts addressed to the loopback interface 380 * are not sent -- the above call to ip_mloopback() will 381 * loop back a copy if this host actually belongs to the 382 * destination group on the loopback interface. 383 */ 384 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 385 m_freem(m); 386 goto done; 387 } 388 389 goto sendit; 390 } 391 #ifndef notdef 392 /* 393 * If the source address is not specified yet, use the address 394 * of the outoing interface. In case, keep note we did that, so 395 * if the the firewall changes the next-hop causing the output 396 * interface to change, we can fix that. 397 */ 398 if (ip->ip_src.s_addr == INADDR_ANY) { 399 /* Interface may have no addresses. */ 400 if (ia != NULL) { 401 ip->ip_src = IA_SIN(ia)->sin_addr; 402 src_was_INADDR_ANY = 1; 403 } 404 } 405 #endif /* notdef */ 406 #ifdef ALTQ 407 /* 408 * Disable packet drop hack. 409 * Packetdrop should be done by queueing. 410 */ 411 #else /* !ALTQ */ 412 /* 413 * Verify that we have any chance at all of being able to queue 414 * the packet or packet fragments 415 */ 416 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 417 ifp->if_snd.ifq_maxlen) { 418 error = ENOBUFS; 419 ipstat.ips_odropped++; 420 goto bad; 421 } 422 #endif /* !ALTQ */ 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 crit_enter(); 587 if (mtag != NULL) { 588 tdbi = (struct tdb_ident *)m_tag_data(mtag); 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 *)m_tag_data(mtag); 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 crit_exit(); 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 crit_exit(); 664 goto done; 665 } else { 666 crit_exit(); 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 *)m_tag_data(mtag)); 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); 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 ro_fwd->ro_rt = NULL; 900 901 rtalloc_ign(ro_fwd, RTF_PRCLONING); 902 if (ro_fwd->ro_rt == NULL) { 903 ipstat.ips_noroute++; 904 error = EHOSTUNREACH; 905 goto bad; 906 } 907 908 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 909 ifp = ro_fwd->ro_rt->rt_ifp; 910 ro_fwd->ro_rt->rt_use++; 911 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 912 dst = (struct sockaddr_in *) 913 ro_fwd->ro_rt->rt_gateway; 914 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 915 isbroadcast = 916 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 917 else 918 isbroadcast = in_broadcast(dst->sin_addr, ifp); 919 if (ro->ro_rt != NULL) 920 rtfree(ro->ro_rt); 921 ro->ro_rt = ro_fwd->ro_rt; 922 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 923 924 #endif /* ... block to be put into a function */ 925 /* 926 * If we added a default src ip earlier, 927 * which would have been gotten from the-then 928 * interface, do it again, from the new one. 929 */ 930 if (src_was_INADDR_ANY) 931 ip->ip_src = IA_SIN(ia)->sin_addr; 932 goto pass ; 933 } 934 935 /* 936 * if we get here, none of the above matches, and 937 * we have to drop the pkt 938 */ 939 m_freem(m); 940 error = EACCES; /* not sure this is the right error msg */ 941 goto done; 942 } 943 944 pass: 945 /* 127/8 must not appear on wire - RFC1122. */ 946 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 947 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 948 if (!(ifp->if_flags & IFF_LOOPBACK)) { 949 ipstat.ips_badaddr++; 950 error = EADDRNOTAVAIL; 951 goto bad; 952 } 953 } 954 955 m->m_pkthdr.csum_flags |= CSUM_IP; 956 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 957 if (sw_csum & CSUM_DELAY_DATA) { 958 in_delayed_cksum(m); 959 sw_csum &= ~CSUM_DELAY_DATA; 960 } 961 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 962 963 /* 964 * If small enough for interface, or the interface will take 965 * care of the fragmentation for us, can just send directly. 966 */ 967 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 968 !(ip->ip_off & IP_DF))) { 969 ip->ip_len = htons(ip->ip_len); 970 ip->ip_off = htons(ip->ip_off); 971 ip->ip_sum = 0; 972 if (sw_csum & CSUM_DELAY_IP) { 973 if (ip->ip_vhl == IP_VHL_BORING) { 974 ip->ip_sum = in_cksum_hdr(ip); 975 } else { 976 ip->ip_sum = in_cksum(m, hlen); 977 } 978 } 979 980 /* Record statistics for this interface address. */ 981 if (!(flags & IP_FORWARDING) && ia) { 982 ia->ia_ifa.if_opackets++; 983 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 984 } 985 986 #ifdef IPSEC 987 /* clean ipsec history once it goes out of the node */ 988 ipsec_delaux(m); 989 #endif 990 991 #ifdef MBUF_STRESS_TEST 992 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 993 struct mbuf *m1, *m2; 994 int length, tmp; 995 996 tmp = length = m->m_pkthdr.len; 997 998 while ((length -= mbuf_frag_size) >= 1) { 999 m1 = m_split(m, length, MB_DONTWAIT); 1000 if (m1 == NULL) 1001 break; 1002 m2 = m; 1003 while (m2->m_next != NULL) 1004 m2 = m2->m_next; 1005 m2->m_next = m1; 1006 } 1007 m->m_pkthdr.len = tmp; 1008 } 1009 #endif 1010 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, 1011 ro->ro_rt); 1012 goto done; 1013 } 1014 1015 if (ip->ip_off & IP_DF) { 1016 error = EMSGSIZE; 1017 /* 1018 * This case can happen if the user changed the MTU 1019 * of an interface after enabling IP on it. Because 1020 * most netifs don't keep track of routes pointing to 1021 * them, there is no way for one to update all its 1022 * routes when the MTU is changed. 1023 */ 1024 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1025 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1026 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1027 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1028 } 1029 ipstat.ips_cantfrag++; 1030 goto bad; 1031 } 1032 1033 /* 1034 * Too large for interface; fragment if possible. If successful, 1035 * on return, m will point to a list of packets to be sent. 1036 */ 1037 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1038 if (error) 1039 goto bad; 1040 for (; m; m = m0) { 1041 m0 = m->m_nextpkt; 1042 m->m_nextpkt = NULL; 1043 #ifdef IPSEC 1044 /* clean ipsec history once it goes out of the node */ 1045 ipsec_delaux(m); 1046 #endif 1047 if (error == 0) { 1048 /* Record statistics for this interface address. */ 1049 if (ia != NULL) { 1050 ia->ia_ifa.if_opackets++; 1051 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1052 } 1053 error = (*ifp->if_output)(ifp, m, 1054 (struct sockaddr *)dst, 1055 ro->ro_rt); 1056 } else 1057 m_freem(m); 1058 } 1059 1060 if (error == 0) 1061 ipstat.ips_fragmented++; 1062 1063 done: 1064 if (ro == &iproute && ro->ro_rt != NULL) { 1065 RTFREE(ro->ro_rt); 1066 ro->ro_rt = NULL; 1067 } 1068 #ifdef IPSEC 1069 if (sp != NULL) { 1070 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1071 printf("DP ip_output call free SP:%p\n", sp)); 1072 key_freesp(sp); 1073 } 1074 #endif 1075 #ifdef FAST_IPSEC 1076 if (sp != NULL) 1077 KEY_FREESP(&sp); 1078 #endif 1079 return (error); 1080 bad: 1081 m_freem(m); 1082 goto done; 1083 } 1084 1085 /* 1086 * Create a chain of fragments which fit the given mtu. m_frag points to the 1087 * mbuf to be fragmented; on return it points to the chain with the fragments. 1088 * Return 0 if no error. If error, m_frag may contain a partially built 1089 * chain of fragments that should be freed by the caller. 1090 * 1091 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1092 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1093 */ 1094 int 1095 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1096 u_long if_hwassist_flags, int sw_csum) 1097 { 1098 int error = 0; 1099 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1100 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1101 int off; 1102 struct mbuf *m0 = *m_frag; /* the original packet */ 1103 int firstlen; 1104 struct mbuf **mnext; 1105 int nfrags; 1106 1107 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1108 ipstat.ips_cantfrag++; 1109 return EMSGSIZE; 1110 } 1111 1112 /* 1113 * Must be able to put at least 8 bytes per fragment. 1114 */ 1115 if (len < 8) 1116 return EMSGSIZE; 1117 1118 /* 1119 * If the interface will not calculate checksums on 1120 * fragmented packets, then do it here. 1121 */ 1122 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1123 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1124 in_delayed_cksum(m0); 1125 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1126 } 1127 1128 if (len > PAGE_SIZE) { 1129 /* 1130 * Fragment large datagrams such that each segment 1131 * contains a multiple of PAGE_SIZE amount of data, 1132 * plus headers. This enables a receiver to perform 1133 * page-flipping zero-copy optimizations. 1134 * 1135 * XXX When does this help given that sender and receiver 1136 * could have different page sizes, and also mtu could 1137 * be less than the receiver's page size ? 1138 */ 1139 int newlen; 1140 struct mbuf *m; 1141 1142 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1143 off += m->m_len; 1144 1145 /* 1146 * firstlen (off - hlen) must be aligned on an 1147 * 8-byte boundary 1148 */ 1149 if (off < hlen) 1150 goto smart_frag_failure; 1151 off = ((off - hlen) & ~7) + hlen; 1152 newlen = (~PAGE_MASK) & mtu; 1153 if ((newlen + sizeof(struct ip)) > mtu) { 1154 /* we failed, go back the default */ 1155 smart_frag_failure: 1156 newlen = len; 1157 off = hlen + len; 1158 } 1159 len = newlen; 1160 1161 } else { 1162 off = hlen + len; 1163 } 1164 1165 firstlen = off - hlen; 1166 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1167 1168 /* 1169 * Loop through length of segment after first fragment, 1170 * make new header and copy data of each part and link onto chain. 1171 * Here, m0 is the original packet, m is the fragment being created. 1172 * The fragments are linked off the m_nextpkt of the original 1173 * packet, which after processing serves as the first fragment. 1174 */ 1175 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1176 struct ip *mhip; /* ip header on the fragment */ 1177 struct mbuf *m; 1178 int mhlen = sizeof(struct ip); 1179 1180 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1181 if (m == NULL) { 1182 error = ENOBUFS; 1183 ipstat.ips_odropped++; 1184 goto done; 1185 } 1186 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1187 /* 1188 * In the first mbuf, leave room for the link header, then 1189 * copy the original IP header including options. The payload 1190 * goes into an additional mbuf chain returned by m_copy(). 1191 */ 1192 m->m_data += max_linkhdr; 1193 mhip = mtod(m, struct ip *); 1194 *mhip = *ip; 1195 if (hlen > sizeof(struct ip)) { 1196 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1197 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1198 } 1199 m->m_len = mhlen; 1200 /* XXX do we need to add ip->ip_off below ? */ 1201 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1202 if (off + len >= ip->ip_len) { /* last fragment */ 1203 len = ip->ip_len - off; 1204 m->m_flags |= M_LASTFRAG; 1205 } else 1206 mhip->ip_off |= IP_MF; 1207 mhip->ip_len = htons((u_short)(len + mhlen)); 1208 m->m_next = m_copy(m0, off, len); 1209 if (m->m_next == NULL) { /* copy failed */ 1210 m_free(m); 1211 error = ENOBUFS; /* ??? */ 1212 ipstat.ips_odropped++; 1213 goto done; 1214 } 1215 m->m_pkthdr.len = mhlen + len; 1216 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1217 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1218 mhip->ip_off = htons(mhip->ip_off); 1219 mhip->ip_sum = 0; 1220 if (sw_csum & CSUM_DELAY_IP) 1221 mhip->ip_sum = in_cksum(m, mhlen); 1222 *mnext = m; 1223 mnext = &m->m_nextpkt; 1224 } 1225 ipstat.ips_ofragments += nfrags; 1226 1227 /* set first marker for fragment chain */ 1228 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1229 m0->m_pkthdr.csum_data = nfrags; 1230 1231 /* 1232 * Update first fragment by trimming what's been copied out 1233 * and updating header. 1234 */ 1235 m_adj(m0, hlen + firstlen - ip->ip_len); 1236 m0->m_pkthdr.len = hlen + firstlen; 1237 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1238 ip->ip_off |= IP_MF; 1239 ip->ip_off = htons(ip->ip_off); 1240 ip->ip_sum = 0; 1241 if (sw_csum & CSUM_DELAY_IP) 1242 ip->ip_sum = in_cksum(m0, hlen); 1243 1244 done: 1245 *m_frag = m0; 1246 return error; 1247 } 1248 1249 void 1250 in_delayed_cksum(struct mbuf *m) 1251 { 1252 struct ip *ip; 1253 u_short csum, offset; 1254 1255 ip = mtod(m, struct ip *); 1256 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1257 csum = in_cksum_skip(m, ip->ip_len, offset); 1258 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1259 csum = 0xffff; 1260 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1261 1262 if (offset + sizeof(u_short) > m->m_len) { 1263 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1264 m->m_len, offset, ip->ip_p); 1265 /* 1266 * XXX 1267 * this shouldn't happen, but if it does, the 1268 * correct behavior may be to insert the checksum 1269 * in the existing chain instead of rearranging it. 1270 */ 1271 m = m_pullup(m, offset + sizeof(u_short)); 1272 } 1273 *(u_short *)(m->m_data + offset) = csum; 1274 } 1275 1276 /* 1277 * Insert IP options into preformed packet. 1278 * Adjust IP destination as required for IP source routing, 1279 * as indicated by a non-zero in_addr at the start of the options. 1280 * 1281 * XXX This routine assumes that the packet has no options in place. 1282 */ 1283 static struct mbuf * 1284 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1285 { 1286 struct ipoption *p = mtod(opt, struct ipoption *); 1287 struct mbuf *n; 1288 struct ip *ip = mtod(m, struct ip *); 1289 unsigned optlen; 1290 1291 optlen = opt->m_len - sizeof p->ipopt_dst; 1292 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1293 *phlen = 0; 1294 return (m); /* XXX should fail */ 1295 } 1296 if (p->ipopt_dst.s_addr) 1297 ip->ip_dst = p->ipopt_dst; 1298 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1299 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1300 if (n == NULL) { 1301 *phlen = 0; 1302 return (m); 1303 } 1304 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 1305 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1306 m->m_len -= sizeof(struct ip); 1307 m->m_data += sizeof(struct ip); 1308 n->m_next = m; 1309 m = n; 1310 m->m_len = optlen + sizeof(struct ip); 1311 m->m_data += max_linkhdr; 1312 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1313 } else { 1314 m->m_data -= optlen; 1315 m->m_len += optlen; 1316 m->m_pkthdr.len += optlen; 1317 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1318 } 1319 ip = mtod(m, struct ip *); 1320 bcopy(p->ipopt_list, ip + 1, optlen); 1321 *phlen = sizeof(struct ip) + optlen; 1322 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1323 ip->ip_len += optlen; 1324 return (m); 1325 } 1326 1327 /* 1328 * Copy options from ip to jp, 1329 * omitting those not copied during fragmentation. 1330 */ 1331 int 1332 ip_optcopy(struct ip *ip, struct ip *jp) 1333 { 1334 u_char *cp, *dp; 1335 int opt, optlen, cnt; 1336 1337 cp = (u_char *)(ip + 1); 1338 dp = (u_char *)(jp + 1); 1339 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1340 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1341 opt = cp[0]; 1342 if (opt == IPOPT_EOL) 1343 break; 1344 if (opt == IPOPT_NOP) { 1345 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1346 *dp++ = IPOPT_NOP; 1347 optlen = 1; 1348 continue; 1349 } 1350 1351 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1352 ("ip_optcopy: malformed ipv4 option")); 1353 optlen = cp[IPOPT_OLEN]; 1354 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1355 ("ip_optcopy: malformed ipv4 option")); 1356 1357 /* bogus lengths should have been caught by ip_dooptions */ 1358 if (optlen > cnt) 1359 optlen = cnt; 1360 if (IPOPT_COPIED(opt)) { 1361 bcopy(cp, dp, optlen); 1362 dp += optlen; 1363 } 1364 } 1365 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1366 *dp++ = IPOPT_EOL; 1367 return (optlen); 1368 } 1369 1370 /* 1371 * IP socket option processing. 1372 */ 1373 int 1374 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1375 { 1376 struct inpcb *inp = so->so_pcb; 1377 int error, optval; 1378 1379 error = optval = 0; 1380 if (sopt->sopt_level != IPPROTO_IP) { 1381 return (EINVAL); 1382 } 1383 1384 switch (sopt->sopt_dir) { 1385 case SOPT_SET: 1386 switch (sopt->sopt_name) { 1387 case IP_OPTIONS: 1388 #ifdef notyet 1389 case IP_RETOPTS: 1390 #endif 1391 { 1392 struct mbuf *m; 1393 if (sopt->sopt_valsize > MLEN) { 1394 error = EMSGSIZE; 1395 break; 1396 } 1397 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1398 if (m == NULL) { 1399 error = ENOBUFS; 1400 break; 1401 } 1402 m->m_len = sopt->sopt_valsize; 1403 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1404 m->m_len); 1405 1406 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1407 m)); 1408 } 1409 1410 case IP_TOS: 1411 case IP_TTL: 1412 case IP_RECVOPTS: 1413 case IP_RECVRETOPTS: 1414 case IP_RECVDSTADDR: 1415 case IP_RECVIF: 1416 case IP_FAITH: 1417 error = sooptcopyin(sopt, &optval, sizeof optval, 1418 sizeof optval); 1419 if (error) 1420 break; 1421 1422 switch (sopt->sopt_name) { 1423 case IP_TOS: 1424 inp->inp_ip_tos = optval; 1425 break; 1426 1427 case IP_TTL: 1428 inp->inp_ip_ttl = optval; 1429 break; 1430 #define OPTSET(bit) \ 1431 if (optval) \ 1432 inp->inp_flags |= bit; \ 1433 else \ 1434 inp->inp_flags &= ~bit; 1435 1436 case IP_RECVOPTS: 1437 OPTSET(INP_RECVOPTS); 1438 break; 1439 1440 case IP_RECVRETOPTS: 1441 OPTSET(INP_RECVRETOPTS); 1442 break; 1443 1444 case IP_RECVDSTADDR: 1445 OPTSET(INP_RECVDSTADDR); 1446 break; 1447 1448 case IP_RECVIF: 1449 OPTSET(INP_RECVIF); 1450 break; 1451 1452 case IP_FAITH: 1453 OPTSET(INP_FAITH); 1454 break; 1455 } 1456 break; 1457 #undef OPTSET 1458 1459 case IP_MULTICAST_IF: 1460 case IP_MULTICAST_VIF: 1461 case IP_MULTICAST_TTL: 1462 case IP_MULTICAST_LOOP: 1463 case IP_ADD_MEMBERSHIP: 1464 case IP_DROP_MEMBERSHIP: 1465 error = ip_setmoptions(sopt, &inp->inp_moptions); 1466 break; 1467 1468 case IP_PORTRANGE: 1469 error = sooptcopyin(sopt, &optval, sizeof optval, 1470 sizeof optval); 1471 if (error) 1472 break; 1473 1474 switch (optval) { 1475 case IP_PORTRANGE_DEFAULT: 1476 inp->inp_flags &= ~(INP_LOWPORT); 1477 inp->inp_flags &= ~(INP_HIGHPORT); 1478 break; 1479 1480 case IP_PORTRANGE_HIGH: 1481 inp->inp_flags &= ~(INP_LOWPORT); 1482 inp->inp_flags |= INP_HIGHPORT; 1483 break; 1484 1485 case IP_PORTRANGE_LOW: 1486 inp->inp_flags &= ~(INP_HIGHPORT); 1487 inp->inp_flags |= INP_LOWPORT; 1488 break; 1489 1490 default: 1491 error = EINVAL; 1492 break; 1493 } 1494 break; 1495 1496 #if defined(IPSEC) || defined(FAST_IPSEC) 1497 case IP_IPSEC_POLICY: 1498 { 1499 caddr_t req; 1500 size_t len = 0; 1501 int priv; 1502 struct mbuf *m; 1503 int optname; 1504 1505 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1506 break; 1507 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1508 break; 1509 priv = (sopt->sopt_td != NULL && 1510 suser(sopt->sopt_td) != 0) ? 0 : 1; 1511 req = mtod(m, caddr_t); 1512 len = m->m_len; 1513 optname = sopt->sopt_name; 1514 error = ipsec4_set_policy(inp, optname, req, len, priv); 1515 m_freem(m); 1516 break; 1517 } 1518 #endif /*IPSEC*/ 1519 1520 default: 1521 error = ENOPROTOOPT; 1522 break; 1523 } 1524 break; 1525 1526 case SOPT_GET: 1527 switch (sopt->sopt_name) { 1528 case IP_OPTIONS: 1529 case IP_RETOPTS: 1530 if (inp->inp_options) 1531 error = sooptcopyout(sopt, 1532 mtod(inp->inp_options, 1533 char *), 1534 inp->inp_options->m_len); 1535 else 1536 sopt->sopt_valsize = 0; 1537 break; 1538 1539 case IP_TOS: 1540 case IP_TTL: 1541 case IP_RECVOPTS: 1542 case IP_RECVRETOPTS: 1543 case IP_RECVDSTADDR: 1544 case IP_RECVIF: 1545 case IP_PORTRANGE: 1546 case IP_FAITH: 1547 switch (sopt->sopt_name) { 1548 1549 case IP_TOS: 1550 optval = inp->inp_ip_tos; 1551 break; 1552 1553 case IP_TTL: 1554 optval = inp->inp_ip_ttl; 1555 break; 1556 1557 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1558 1559 case IP_RECVOPTS: 1560 optval = OPTBIT(INP_RECVOPTS); 1561 break; 1562 1563 case IP_RECVRETOPTS: 1564 optval = OPTBIT(INP_RECVRETOPTS); 1565 break; 1566 1567 case IP_RECVDSTADDR: 1568 optval = OPTBIT(INP_RECVDSTADDR); 1569 break; 1570 1571 case IP_RECVIF: 1572 optval = OPTBIT(INP_RECVIF); 1573 break; 1574 1575 case IP_PORTRANGE: 1576 if (inp->inp_flags & INP_HIGHPORT) 1577 optval = IP_PORTRANGE_HIGH; 1578 else if (inp->inp_flags & INP_LOWPORT) 1579 optval = IP_PORTRANGE_LOW; 1580 else 1581 optval = 0; 1582 break; 1583 1584 case IP_FAITH: 1585 optval = OPTBIT(INP_FAITH); 1586 break; 1587 } 1588 error = sooptcopyout(sopt, &optval, sizeof optval); 1589 break; 1590 1591 case IP_MULTICAST_IF: 1592 case IP_MULTICAST_VIF: 1593 case IP_MULTICAST_TTL: 1594 case IP_MULTICAST_LOOP: 1595 case IP_ADD_MEMBERSHIP: 1596 case IP_DROP_MEMBERSHIP: 1597 error = ip_getmoptions(sopt, inp->inp_moptions); 1598 break; 1599 1600 #if defined(IPSEC) || defined(FAST_IPSEC) 1601 case IP_IPSEC_POLICY: 1602 { 1603 struct mbuf *m = NULL; 1604 caddr_t req = NULL; 1605 size_t len = 0; 1606 1607 if (m != NULL) { 1608 req = mtod(m, caddr_t); 1609 len = m->m_len; 1610 } 1611 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1612 if (error == 0) 1613 error = soopt_mcopyout(sopt, m); /* XXX */ 1614 if (error == 0) 1615 m_freem(m); 1616 break; 1617 } 1618 #endif /*IPSEC*/ 1619 1620 default: 1621 error = ENOPROTOOPT; 1622 break; 1623 } 1624 break; 1625 } 1626 return (error); 1627 } 1628 1629 /* 1630 * Set up IP options in pcb for insertion in output packets. 1631 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1632 * with destination address if source routed. 1633 */ 1634 static int 1635 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1636 { 1637 int cnt, optlen; 1638 u_char *cp; 1639 u_char opt; 1640 1641 /* turn off any old options */ 1642 if (*pcbopt) 1643 m_free(*pcbopt); 1644 *pcbopt = 0; 1645 if (m == NULL || m->m_len == 0) { 1646 /* 1647 * Only turning off any previous options. 1648 */ 1649 if (m != NULL) 1650 m_free(m); 1651 return (0); 1652 } 1653 1654 if (m->m_len % sizeof(int32_t)) 1655 goto bad; 1656 /* 1657 * IP first-hop destination address will be stored before 1658 * actual options; move other options back 1659 * and clear it when none present. 1660 */ 1661 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1662 goto bad; 1663 cnt = m->m_len; 1664 m->m_len += sizeof(struct in_addr); 1665 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1666 ovbcopy(mtod(m, caddr_t), cp, cnt); 1667 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1668 1669 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1670 opt = cp[IPOPT_OPTVAL]; 1671 if (opt == IPOPT_EOL) 1672 break; 1673 if (opt == IPOPT_NOP) 1674 optlen = 1; 1675 else { 1676 if (cnt < IPOPT_OLEN + sizeof *cp) 1677 goto bad; 1678 optlen = cp[IPOPT_OLEN]; 1679 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1680 goto bad; 1681 } 1682 switch (opt) { 1683 1684 default: 1685 break; 1686 1687 case IPOPT_LSRR: 1688 case IPOPT_SSRR: 1689 /* 1690 * user process specifies route as: 1691 * ->A->B->C->D 1692 * D must be our final destination (but we can't 1693 * check that since we may not have connected yet). 1694 * A is first hop destination, which doesn't appear in 1695 * actual IP option, but is stored before the options. 1696 */ 1697 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1698 goto bad; 1699 m->m_len -= sizeof(struct in_addr); 1700 cnt -= sizeof(struct in_addr); 1701 optlen -= sizeof(struct in_addr); 1702 cp[IPOPT_OLEN] = optlen; 1703 /* 1704 * Move first hop before start of options. 1705 */ 1706 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1707 sizeof(struct in_addr)); 1708 /* 1709 * Then copy rest of options back 1710 * to close up the deleted entry. 1711 */ 1712 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1713 &cp[IPOPT_OFFSET+1], 1714 cnt - (IPOPT_MINOFF - 1)); 1715 break; 1716 } 1717 } 1718 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1719 goto bad; 1720 *pcbopt = m; 1721 return (0); 1722 1723 bad: 1724 m_free(m); 1725 return (EINVAL); 1726 } 1727 1728 /* 1729 * XXX 1730 * The whole multicast option thing needs to be re-thought. 1731 * Several of these options are equally applicable to non-multicast 1732 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1733 * standard option (IP_TTL). 1734 */ 1735 1736 /* 1737 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1738 */ 1739 static struct ifnet * 1740 ip_multicast_if(struct in_addr *a, int *ifindexp) 1741 { 1742 int ifindex; 1743 struct ifnet *ifp; 1744 1745 if (ifindexp) 1746 *ifindexp = 0; 1747 if (ntohl(a->s_addr) >> 24 == 0) { 1748 ifindex = ntohl(a->s_addr) & 0xffffff; 1749 if (ifindex < 0 || if_index < ifindex) 1750 return NULL; 1751 ifp = ifindex2ifnet[ifindex]; 1752 if (ifindexp) 1753 *ifindexp = ifindex; 1754 } else { 1755 INADDR_TO_IFP(*a, ifp); 1756 } 1757 return ifp; 1758 } 1759 1760 /* 1761 * Set the IP multicast options in response to user setsockopt(). 1762 */ 1763 static int 1764 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1765 { 1766 int error = 0; 1767 int i; 1768 struct in_addr addr; 1769 struct ip_mreq mreq; 1770 struct ifnet *ifp; 1771 struct ip_moptions *imo = *imop; 1772 int ifindex; 1773 1774 if (imo == NULL) { 1775 /* 1776 * No multicast option buffer attached to the pcb; 1777 * allocate one and initialize to default values. 1778 */ 1779 imo = malloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1780 1781 if (imo == NULL) 1782 return (ENOBUFS); 1783 *imop = imo; 1784 imo->imo_multicast_ifp = NULL; 1785 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1786 imo->imo_multicast_vif = -1; 1787 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1788 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1789 imo->imo_num_memberships = 0; 1790 } 1791 1792 switch (sopt->sopt_name) { 1793 /* store an index number for the vif you wanna use in the send */ 1794 case IP_MULTICAST_VIF: 1795 if (legal_vif_num == 0) { 1796 error = EOPNOTSUPP; 1797 break; 1798 } 1799 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1800 if (error) 1801 break; 1802 if (!legal_vif_num(i) && (i != -1)) { 1803 error = EINVAL; 1804 break; 1805 } 1806 imo->imo_multicast_vif = i; 1807 break; 1808 1809 case IP_MULTICAST_IF: 1810 /* 1811 * Select the interface for outgoing multicast packets. 1812 */ 1813 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1814 if (error) 1815 break; 1816 /* 1817 * INADDR_ANY is used to remove a previous selection. 1818 * When no interface is selected, a default one is 1819 * chosen every time a multicast packet is sent. 1820 */ 1821 if (addr.s_addr == INADDR_ANY) { 1822 imo->imo_multicast_ifp = NULL; 1823 break; 1824 } 1825 /* 1826 * The selected interface is identified by its local 1827 * IP address. Find the interface and confirm that 1828 * it supports multicasting. 1829 */ 1830 crit_enter(); 1831 ifp = ip_multicast_if(&addr, &ifindex); 1832 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1833 crit_exit(); 1834 error = EADDRNOTAVAIL; 1835 break; 1836 } 1837 imo->imo_multicast_ifp = ifp; 1838 if (ifindex) 1839 imo->imo_multicast_addr = addr; 1840 else 1841 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1842 crit_exit(); 1843 break; 1844 1845 case IP_MULTICAST_TTL: 1846 /* 1847 * Set the IP time-to-live for outgoing multicast packets. 1848 * The original multicast API required a char argument, 1849 * which is inconsistent with the rest of the socket API. 1850 * We allow either a char or an int. 1851 */ 1852 if (sopt->sopt_valsize == 1) { 1853 u_char ttl; 1854 error = sooptcopyin(sopt, &ttl, 1, 1); 1855 if (error) 1856 break; 1857 imo->imo_multicast_ttl = ttl; 1858 } else { 1859 u_int ttl; 1860 error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl); 1861 if (error) 1862 break; 1863 if (ttl > 255) 1864 error = EINVAL; 1865 else 1866 imo->imo_multicast_ttl = ttl; 1867 } 1868 break; 1869 1870 case IP_MULTICAST_LOOP: 1871 /* 1872 * Set the loopback flag for outgoing multicast packets. 1873 * Must be zero or one. The original multicast API required a 1874 * char argument, which is inconsistent with the rest 1875 * of the socket API. We allow either a char or an int. 1876 */ 1877 if (sopt->sopt_valsize == 1) { 1878 u_char loop; 1879 1880 error = sooptcopyin(sopt, &loop, 1, 1); 1881 if (error) 1882 break; 1883 imo->imo_multicast_loop = !!loop; 1884 } else { 1885 u_int loop; 1886 1887 error = sooptcopyin(sopt, &loop, sizeof loop, 1888 sizeof loop); 1889 if (error) 1890 break; 1891 imo->imo_multicast_loop = !!loop; 1892 } 1893 break; 1894 1895 case IP_ADD_MEMBERSHIP: 1896 /* 1897 * Add a multicast group membership. 1898 * Group must be a valid IP multicast address. 1899 */ 1900 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1901 if (error) 1902 break; 1903 1904 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1905 error = EINVAL; 1906 break; 1907 } 1908 crit_enter(); 1909 /* 1910 * If no interface address was provided, use the interface of 1911 * the route to the given multicast address. 1912 */ 1913 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1914 struct sockaddr_in dst; 1915 struct rtentry *rt; 1916 1917 bzero(&dst, sizeof(struct sockaddr_in)); 1918 dst.sin_len = sizeof(struct sockaddr_in); 1919 dst.sin_family = AF_INET; 1920 dst.sin_addr = mreq.imr_multiaddr; 1921 rt = rtlookup((struct sockaddr *)&dst); 1922 if (rt == NULL) { 1923 error = EADDRNOTAVAIL; 1924 crit_exit(); 1925 break; 1926 } 1927 --rt->rt_refcnt; 1928 ifp = rt->rt_ifp; 1929 } else { 1930 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1931 } 1932 1933 /* 1934 * See if we found an interface, and confirm that it 1935 * supports multicast. 1936 */ 1937 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1938 error = EADDRNOTAVAIL; 1939 crit_exit(); 1940 break; 1941 } 1942 /* 1943 * See if the membership already exists or if all the 1944 * membership slots are full. 1945 */ 1946 for (i = 0; i < imo->imo_num_memberships; ++i) { 1947 if (imo->imo_membership[i]->inm_ifp == ifp && 1948 imo->imo_membership[i]->inm_addr.s_addr 1949 == mreq.imr_multiaddr.s_addr) 1950 break; 1951 } 1952 if (i < imo->imo_num_memberships) { 1953 error = EADDRINUSE; 1954 crit_exit(); 1955 break; 1956 } 1957 if (i == IP_MAX_MEMBERSHIPS) { 1958 error = ETOOMANYREFS; 1959 crit_exit(); 1960 break; 1961 } 1962 /* 1963 * Everything looks good; add a new record to the multicast 1964 * address list for the given interface. 1965 */ 1966 if ((imo->imo_membership[i] = 1967 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1968 error = ENOBUFS; 1969 crit_exit(); 1970 break; 1971 } 1972 ++imo->imo_num_memberships; 1973 crit_exit(); 1974 break; 1975 1976 case IP_DROP_MEMBERSHIP: 1977 /* 1978 * Drop a multicast group membership. 1979 * Group must be a valid IP multicast address. 1980 */ 1981 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1982 if (error) 1983 break; 1984 1985 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1986 error = EINVAL; 1987 break; 1988 } 1989 1990 crit_enter(); 1991 /* 1992 * If an interface address was specified, get a pointer 1993 * to its ifnet structure. 1994 */ 1995 if (mreq.imr_interface.s_addr == INADDR_ANY) 1996 ifp = NULL; 1997 else { 1998 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1999 if (ifp == NULL) { 2000 error = EADDRNOTAVAIL; 2001 crit_exit(); 2002 break; 2003 } 2004 } 2005 /* 2006 * Find the membership in the membership array. 2007 */ 2008 for (i = 0; i < imo->imo_num_memberships; ++i) { 2009 if ((ifp == NULL || 2010 imo->imo_membership[i]->inm_ifp == ifp) && 2011 imo->imo_membership[i]->inm_addr.s_addr == 2012 mreq.imr_multiaddr.s_addr) 2013 break; 2014 } 2015 if (i == imo->imo_num_memberships) { 2016 error = EADDRNOTAVAIL; 2017 crit_exit(); 2018 break; 2019 } 2020 /* 2021 * Give up the multicast address record to which the 2022 * membership points. 2023 */ 2024 in_delmulti(imo->imo_membership[i]); 2025 /* 2026 * Remove the gap in the membership array. 2027 */ 2028 for (++i; i < imo->imo_num_memberships; ++i) 2029 imo->imo_membership[i-1] = imo->imo_membership[i]; 2030 --imo->imo_num_memberships; 2031 crit_exit(); 2032 break; 2033 2034 default: 2035 error = EOPNOTSUPP; 2036 break; 2037 } 2038 2039 /* 2040 * If all options have default values, no need to keep the mbuf. 2041 */ 2042 if (imo->imo_multicast_ifp == NULL && 2043 imo->imo_multicast_vif == -1 && 2044 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2045 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2046 imo->imo_num_memberships == 0) { 2047 free(*imop, M_IPMOPTS); 2048 *imop = NULL; 2049 } 2050 2051 return (error); 2052 } 2053 2054 /* 2055 * Return the IP multicast options in response to user getsockopt(). 2056 */ 2057 static int 2058 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2059 { 2060 struct in_addr addr; 2061 struct in_ifaddr *ia; 2062 int error, optval; 2063 u_char coptval; 2064 2065 error = 0; 2066 switch (sopt->sopt_name) { 2067 case IP_MULTICAST_VIF: 2068 if (imo != NULL) 2069 optval = imo->imo_multicast_vif; 2070 else 2071 optval = -1; 2072 error = sooptcopyout(sopt, &optval, sizeof optval); 2073 break; 2074 2075 case IP_MULTICAST_IF: 2076 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2077 addr.s_addr = INADDR_ANY; 2078 else if (imo->imo_multicast_addr.s_addr) { 2079 /* return the value user has set */ 2080 addr = imo->imo_multicast_addr; 2081 } else { 2082 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2083 addr.s_addr = (ia == NULL) ? INADDR_ANY 2084 : IA_SIN(ia)->sin_addr.s_addr; 2085 } 2086 error = sooptcopyout(sopt, &addr, sizeof addr); 2087 break; 2088 2089 case IP_MULTICAST_TTL: 2090 if (imo == NULL) 2091 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2092 else 2093 optval = coptval = imo->imo_multicast_ttl; 2094 if (sopt->sopt_valsize == 1) 2095 error = sooptcopyout(sopt, &coptval, 1); 2096 else 2097 error = sooptcopyout(sopt, &optval, sizeof optval); 2098 break; 2099 2100 case IP_MULTICAST_LOOP: 2101 if (imo == NULL) 2102 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2103 else 2104 optval = coptval = imo->imo_multicast_loop; 2105 if (sopt->sopt_valsize == 1) 2106 error = sooptcopyout(sopt, &coptval, 1); 2107 else 2108 error = sooptcopyout(sopt, &optval, sizeof optval); 2109 break; 2110 2111 default: 2112 error = ENOPROTOOPT; 2113 break; 2114 } 2115 return (error); 2116 } 2117 2118 /* 2119 * Discard the IP multicast options. 2120 */ 2121 void 2122 ip_freemoptions(struct ip_moptions *imo) 2123 { 2124 int i; 2125 2126 if (imo != NULL) { 2127 for (i = 0; i < imo->imo_num_memberships; ++i) 2128 in_delmulti(imo->imo_membership[i]); 2129 free(imo, M_IPMOPTS); 2130 } 2131 } 2132 2133 /* 2134 * Routine called from ip_output() to loop back a copy of an IP multicast 2135 * packet to the input queue of a specified interface. Note that this 2136 * calls the output routine of the loopback "driver", but with an interface 2137 * pointer that might NOT be a loopback interface -- evil, but easier than 2138 * replicating that code here. 2139 */ 2140 static void 2141 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2142 int hlen) 2143 { 2144 struct ip *ip; 2145 struct mbuf *copym; 2146 2147 copym = m_copypacket(m, MB_DONTWAIT); 2148 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2149 copym = m_pullup(copym, hlen); 2150 if (copym != NULL) { 2151 /* 2152 * if the checksum hasn't been computed, mark it as valid 2153 */ 2154 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2155 in_delayed_cksum(copym); 2156 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2157 copym->m_pkthdr.csum_flags |= 2158 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2159 copym->m_pkthdr.csum_data = 0xffff; 2160 } 2161 /* 2162 * We don't bother to fragment if the IP length is greater 2163 * than the interface's MTU. Can this possibly matter? 2164 */ 2165 ip = mtod(copym, struct ip *); 2166 ip->ip_len = htons(ip->ip_len); 2167 ip->ip_off = htons(ip->ip_off); 2168 ip->ip_sum = 0; 2169 if (ip->ip_vhl == IP_VHL_BORING) { 2170 ip->ip_sum = in_cksum_hdr(ip); 2171 } else { 2172 ip->ip_sum = in_cksum(copym, hlen); 2173 } 2174 /* 2175 * NB: 2176 * It's not clear whether there are any lingering 2177 * reentrancy problems in other areas which might 2178 * be exposed by using ip_input directly (in 2179 * particular, everything which modifies the packet 2180 * in-place). Yet another option is using the 2181 * protosw directly to deliver the looped back 2182 * packet. For the moment, we'll err on the side 2183 * of safety by using if_simloop(). 2184 */ 2185 #if 1 /* XXX */ 2186 if (dst->sin_family != AF_INET) { 2187 printf("ip_mloopback: bad address family %d\n", 2188 dst->sin_family); 2189 dst->sin_family = AF_INET; 2190 } 2191 #endif 2192 2193 #ifdef notdef 2194 copym->m_pkthdr.rcvif = ifp; 2195 ip_input(copym); 2196 #else 2197 if_simloop(ifp, copym, dst->sin_family, 0); 2198 #endif 2199 } 2200 } 2201