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 1.24 2004/12/28 08:09:59 hsu Exp $ 32 */ 33 34 #define _IP_VHL 35 36 #include "opt_ipfw.h" 37 #include "opt_ipdn.h" 38 #include "opt_ipdivert.h" 39 #include "opt_ipfilter.h" 40 #include "opt_ipsec.h" 41 #include "opt_random_ip_id.h" 42 #include "opt_mbuf_stress_test.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/sysctl.h> 54 #include <sys/in_cksum.h> 55 56 #include <net/if.h> 57 #include <net/netisr.h> 58 #include <net/pfil.h> 59 #include <net/route.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/ip.h> 64 #include <netinet/in_pcb.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip_var.h> 67 68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 69 70 #ifdef IPSEC 71 #include <netinet6/ipsec.h> 72 #include <netproto/key/key.h> 73 #ifdef IPSEC_DEBUG 74 #include <netproto/key/key_debug.h> 75 #else 76 #define KEYDEBUG(lev,arg) 77 #endif 78 #endif /*IPSEC*/ 79 80 #ifdef FAST_IPSEC 81 #include <netproto/ipsec/ipsec.h> 82 #include <netproto/ipsec/xform.h> 83 #include <netproto/ipsec/key.h> 84 #endif /*FAST_IPSEC*/ 85 86 #include <net/ipfw/ip_fw.h> 87 #include <net/dummynet/ip_dummynet.h> 88 89 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 90 x, (ntohl(a.s_addr)>>24)&0xFF,\ 91 (ntohl(a.s_addr)>>16)&0xFF,\ 92 (ntohl(a.s_addr)>>8)&0xFF,\ 93 (ntohl(a.s_addr))&0xFF, y); 94 95 u_short ip_id; 96 97 #ifdef MBUF_STRESS_TEST 98 int mbuf_frag_size = 0; 99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 101 #endif 102 103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 104 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 105 static void ip_mloopback 106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 107 static int ip_getmoptions 108 (struct sockopt *, struct ip_moptions *); 109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 110 static int ip_setmoptions 111 (struct sockopt *, struct ip_moptions **); 112 113 int ip_optcopy(struct ip *, struct ip *); 114 115 116 extern struct protosw inetsw[]; 117 118 /* 119 * IP output. The packet in mbuf chain m contains a skeletal IP 120 * header (with len, off, ttl, proto, tos, src, dst). 121 * The mbuf chain containing the packet will be freed. 122 * The mbuf opt, if present, will not be freed. 123 */ 124 int 125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 126 int flags, struct ip_moptions *imo, struct inpcb *inp) 127 { 128 struct ip *ip; 129 struct ifnet *ifp = NULL; /* keep compiler happy */ 130 struct mbuf *m; 131 int hlen = sizeof(struct ip); 132 int len, off, error = 0; 133 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 134 struct in_ifaddr *ia = NULL; 135 int isbroadcast, sw_csum; 136 struct in_addr pkt_dst; 137 struct route iproute; 138 #ifdef IPSEC 139 struct secpolicy *sp = NULL; 140 struct socket *so = inp ? inp->inp_socket : NULL; 141 #endif 142 #ifdef FAST_IPSEC 143 struct m_tag *mtag; 144 struct secpolicy *sp = NULL; 145 struct tdb_ident *tdbi; 146 int s; 147 #endif /* FAST_IPSEC */ 148 struct ip_fw_args args; 149 int src_was_INADDR_ANY = 0; /* as the name says... */ 150 151 args.eh = NULL; 152 args.rule = NULL; 153 args.next_hop = NULL; 154 args.divert_rule = 0; /* divert cookie */ 155 156 /* Grab info from MT_TAG mbufs prepended to the chain. */ 157 while (m0 != NULL && m0->m_type == MT_TAG) { 158 switch(m0->_m_tag_id) { 159 case PACKET_TAG_DUMMYNET: 160 /* 161 * the packet was already tagged, so part of the 162 * processing was already done, and we need to go down. 163 * Get parameters from the header. 164 */ 165 args.rule = ((struct dn_pkt *)m0)->rule; 166 opt = NULL ; 167 ro = &((struct dn_pkt *)m0)->ro; 168 imo = NULL ; 169 dst = ((struct dn_pkt *)m0)->dn_dst ; 170 ifp = ((struct dn_pkt *)m0)->ifp ; 171 flags = ((struct dn_pkt *)m0)->flags ; 172 break; 173 case PACKET_TAG_DIVERT: 174 args.divert_rule = (int)m0->m_data & 0xffff; 175 break; 176 case PACKET_TAG_IPFORWARD: 177 args.next_hop = (struct sockaddr_in *)m0->m_data; 178 break; 179 default: 180 printf("ip_output: unrecognised MT_TAG tag %d\n", 181 m0->_m_tag_id); 182 break; 183 } 184 m0 = m0->m_next; 185 } 186 m = m0; 187 KASSERT(m != NULL && (m->m_flags & M_PKTHDR), ("ip_output: no HDR")); 188 189 if (ro == NULL) { 190 ro = &iproute; 191 bzero(ro, sizeof *ro); 192 } 193 194 if (args.rule != NULL) { /* dummynet already saw us */ 195 ip = mtod(m, struct ip *); 196 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 197 if (ro->ro_rt) 198 ia = ifatoia(ro->ro_rt->rt_ifa); 199 goto sendit; 200 } 201 202 if (opt) { 203 len = 0; 204 m = ip_insertoptions(m, opt, &len); 205 if (len != 0) 206 hlen = len; 207 } 208 ip = mtod(m, struct ip *); 209 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 210 211 /* 212 * Fill in IP header. 213 */ 214 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 215 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 216 ip->ip_off &= IP_DF; 217 #ifdef RANDOM_IP_ID 218 ip->ip_id = ip_randomid(); 219 #else 220 ip->ip_id = htons(ip_id++); 221 #endif 222 ipstat.ips_localout++; 223 } else { 224 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 225 } 226 227 dst = (struct sockaddr_in *)&ro->ro_dst; 228 /* 229 * If there is a cached route, 230 * check that it is to the same destination 231 * and is still up. If not, free it and try again. 232 * The address family should also be checked in case of sharing the 233 * cache with IPv6. 234 */ 235 if (ro->ro_rt && 236 (!(ro->ro_rt->rt_flags & RTF_UP) || 237 dst->sin_family != AF_INET || 238 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 239 rtfree(ro->ro_rt); 240 ro->ro_rt = (struct rtentry *)NULL; 241 } 242 if (ro->ro_rt == NULL) { 243 bzero(dst, sizeof *dst); 244 dst->sin_family = AF_INET; 245 dst->sin_len = sizeof *dst; 246 dst->sin_addr = pkt_dst; 247 } 248 /* 249 * If routing to interface only, 250 * short circuit routing lookup. 251 */ 252 if (flags & IP_ROUTETOIF) { 253 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 254 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 255 ipstat.ips_noroute++; 256 error = ENETUNREACH; 257 goto bad; 258 } 259 ifp = ia->ia_ifp; 260 ip->ip_ttl = 1; 261 isbroadcast = in_broadcast(dst->sin_addr, ifp); 262 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 263 imo != NULL && imo->imo_multicast_ifp != NULL) { 264 /* 265 * Bypass the normal routing lookup for multicast 266 * packets if the interface is specified. 267 */ 268 ifp = imo->imo_multicast_ifp; 269 IFP_TO_IA(ifp, ia); 270 isbroadcast = 0; /* fool gcc */ 271 } else { 272 /* 273 * If this is the case, we probably don't want to allocate 274 * a protocol-cloned route since we didn't get one from the 275 * ULP. This lets TCP do its thing, while not burdening 276 * forwarding or ICMP with the overhead of cloning a route. 277 * Of course, we still want to do any cloning requested by 278 * the link layer, as this is probably required in all cases 279 * for correct operation (as it is for ARP). 280 */ 281 if (ro->ro_rt == NULL) 282 rtalloc_ign(ro, RTF_PRCLONING); 283 if (ro->ro_rt == NULL) { 284 ipstat.ips_noroute++; 285 error = EHOSTUNREACH; 286 goto bad; 287 } 288 ia = ifatoia(ro->ro_rt->rt_ifa); 289 ifp = ro->ro_rt->rt_ifp; 290 ro->ro_rt->rt_use++; 291 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 292 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 293 if (ro->ro_rt->rt_flags & RTF_HOST) 294 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 295 else 296 isbroadcast = in_broadcast(dst->sin_addr, ifp); 297 } 298 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 299 struct in_multi *inm; 300 301 m->m_flags |= M_MCAST; 302 /* 303 * IP destination address is multicast. Make sure "dst" 304 * still points to the address in "ro". (It may have been 305 * changed to point to a gateway address, above.) 306 */ 307 dst = (struct sockaddr_in *)&ro->ro_dst; 308 /* 309 * See if the caller provided any multicast options 310 */ 311 if (imo != NULL) { 312 ip->ip_ttl = imo->imo_multicast_ttl; 313 if (imo->imo_multicast_vif != -1) 314 ip->ip_src.s_addr = 315 ip_mcast_src ? 316 ip_mcast_src(imo->imo_multicast_vif) : 317 INADDR_ANY; 318 } else 319 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 320 /* 321 * Confirm that the outgoing interface supports multicast. 322 */ 323 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 324 if (!(ifp->if_flags & IFF_MULTICAST)) { 325 ipstat.ips_noroute++; 326 error = ENETUNREACH; 327 goto bad; 328 } 329 } 330 /* 331 * If source address not specified yet, use address 332 * of outgoing interface. 333 */ 334 if (ip->ip_src.s_addr == INADDR_ANY) { 335 /* Interface may have no addresses. */ 336 if (ia != NULL) 337 ip->ip_src = IA_SIN(ia)->sin_addr; 338 } 339 340 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 341 if (inm != NULL && 342 (imo == NULL || imo->imo_multicast_loop)) { 343 /* 344 * If we belong to the destination multicast group 345 * on the outgoing interface, and the caller did not 346 * forbid loopback, loop back a copy. 347 */ 348 ip_mloopback(ifp, m, dst, hlen); 349 } 350 else { 351 /* 352 * If we are acting as a multicast router, perform 353 * multicast forwarding as if the packet had just 354 * arrived on the interface to which we are about 355 * to send. The multicast forwarding function 356 * recursively calls this function, using the 357 * IP_FORWARDING flag to prevent infinite recursion. 358 * 359 * Multicasts that are looped back by ip_mloopback(), 360 * above, will be forwarded by the ip_input() routine, 361 * if necessary. 362 */ 363 if (ip_mrouter && !(flags & IP_FORWARDING)) { 364 /* 365 * If rsvp daemon is not running, do not 366 * set ip_moptions. This ensures that the packet 367 * is multicast and not just sent down one link 368 * as prescribed by rsvpd. 369 */ 370 if (!rsvp_on) 371 imo = NULL; 372 if (ip_mforward && 373 ip_mforward(ip, ifp, m, imo) != 0) { 374 m_freem(m); 375 goto done; 376 } 377 } 378 } 379 380 /* 381 * Multicasts with a time-to-live of zero may be looped- 382 * back, above, but must not be transmitted on a network. 383 * Also, multicasts addressed to the loopback interface 384 * are not sent -- the above call to ip_mloopback() will 385 * loop back a copy if this host actually belongs to the 386 * destination group on the loopback interface. 387 */ 388 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 389 m_freem(m); 390 goto done; 391 } 392 393 goto sendit; 394 } 395 #ifndef notdef 396 /* 397 * If the source address is not specified yet, use the address 398 * of the outoing interface. In case, keep note we did that, so 399 * if the the firewall changes the next-hop causing the output 400 * interface to change, we can fix that. 401 */ 402 if (ip->ip_src.s_addr == INADDR_ANY) { 403 /* Interface may have no addresses. */ 404 if (ia != NULL) { 405 ip->ip_src = IA_SIN(ia)->sin_addr; 406 src_was_INADDR_ANY = 1; 407 } 408 } 409 #endif /* notdef */ 410 /* 411 * Verify that we have any chance at all of being able to queue 412 * the packet or packet fragments 413 */ 414 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 415 ifp->if_snd.ifq_maxlen) { 416 error = ENOBUFS; 417 ipstat.ips_odropped++; 418 goto bad; 419 } 420 421 /* 422 * Look for broadcast address and 423 * verify user is allowed to send 424 * such a packet. 425 */ 426 if (isbroadcast) { 427 if (!(ifp->if_flags & IFF_BROADCAST)) { 428 error = EADDRNOTAVAIL; 429 goto bad; 430 } 431 if (!(flags & IP_ALLOWBROADCAST)) { 432 error = EACCES; 433 goto bad; 434 } 435 /* don't allow broadcast messages to be fragmented */ 436 if (ip->ip_len > ifp->if_mtu) { 437 error = EMSGSIZE; 438 goto bad; 439 } 440 m->m_flags |= M_BCAST; 441 } else { 442 m->m_flags &= ~M_BCAST; 443 } 444 445 sendit: 446 #ifdef IPSEC 447 /* get SP for this packet */ 448 if (so == NULL) 449 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 450 else 451 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 452 453 if (sp == NULL) { 454 ipsecstat.out_inval++; 455 goto bad; 456 } 457 458 error = 0; 459 460 /* check policy */ 461 switch (sp->policy) { 462 case IPSEC_POLICY_DISCARD: 463 /* 464 * This packet is just discarded. 465 */ 466 ipsecstat.out_polvio++; 467 goto bad; 468 469 case IPSEC_POLICY_BYPASS: 470 case IPSEC_POLICY_NONE: 471 /* no need to do IPsec. */ 472 goto skip_ipsec; 473 474 case IPSEC_POLICY_IPSEC: 475 if (sp->req == NULL) { 476 /* acquire a policy */ 477 error = key_spdacquire(sp); 478 goto bad; 479 } 480 break; 481 482 case IPSEC_POLICY_ENTRUST: 483 default: 484 printf("ip_output: Invalid policy found. %d\n", sp->policy); 485 } 486 { 487 struct ipsec_output_state state; 488 bzero(&state, sizeof state); 489 state.m = m; 490 if (flags & IP_ROUTETOIF) { 491 state.ro = &iproute; 492 bzero(&iproute, sizeof iproute); 493 } else 494 state.ro = ro; 495 state.dst = (struct sockaddr *)dst; 496 497 ip->ip_sum = 0; 498 499 /* 500 * XXX 501 * delayed checksums are not currently compatible with IPsec 502 */ 503 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 504 in_delayed_cksum(m); 505 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 506 } 507 508 ip->ip_len = htons(ip->ip_len); 509 ip->ip_off = htons(ip->ip_off); 510 511 error = ipsec4_output(&state, sp, flags); 512 513 m = state.m; 514 if (flags & IP_ROUTETOIF) { 515 /* 516 * if we have tunnel mode SA, we may need to ignore 517 * IP_ROUTETOIF. 518 */ 519 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 520 flags &= ~IP_ROUTETOIF; 521 ro = state.ro; 522 } 523 } else 524 ro = state.ro; 525 dst = (struct sockaddr_in *)state.dst; 526 if (error) { 527 /* mbuf is already reclaimed in ipsec4_output. */ 528 m0 = NULL; 529 switch (error) { 530 case EHOSTUNREACH: 531 case ENETUNREACH: 532 case EMSGSIZE: 533 case ENOBUFS: 534 case ENOMEM: 535 break; 536 default: 537 printf("ip4_output (ipsec): error code %d\n", error); 538 /*fall through*/ 539 case ENOENT: 540 /* don't show these error codes to the user */ 541 error = 0; 542 break; 543 } 544 goto bad; 545 } 546 } 547 548 /* be sure to update variables that are affected by ipsec4_output() */ 549 ip = mtod(m, struct ip *); 550 #ifdef _IP_VHL 551 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 552 #else 553 hlen = ip->ip_hl << 2; 554 #endif 555 if (ro->ro_rt == NULL) { 556 if (!(flags & IP_ROUTETOIF)) { 557 printf("ip_output: " 558 "can't update route after IPsec processing\n"); 559 error = EHOSTUNREACH; /*XXX*/ 560 goto bad; 561 } 562 } else { 563 ia = ifatoia(ro->ro_rt->rt_ifa); 564 ifp = ro->ro_rt->rt_ifp; 565 } 566 567 /* make it flipped, again. */ 568 ip->ip_len = ntohs(ip->ip_len); 569 ip->ip_off = ntohs(ip->ip_off); 570 skip_ipsec: 571 #endif /*IPSEC*/ 572 #ifdef FAST_IPSEC 573 /* 574 * Check the security policy (SP) for the packet and, if 575 * required, do IPsec-related processing. There are two 576 * cases here; the first time a packet is sent through 577 * it will be untagged and handled by ipsec4_checkpolicy. 578 * If the packet is resubmitted to ip_output (e.g. after 579 * AH, ESP, etc. processing), there will be a tag to bypass 580 * the lookup and related policy checking. 581 */ 582 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 583 s = splnet(); 584 if (mtag != NULL) { 585 tdbi = (struct tdb_ident *)(mtag + 1); 586 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 587 if (sp == NULL) 588 error = -EINVAL; /* force silent drop */ 589 m_tag_delete(m, mtag); 590 } else { 591 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 592 &error, inp); 593 } 594 /* 595 * There are four return cases: 596 * sp != NULL apply IPsec policy 597 * sp == NULL, error == 0 no IPsec handling needed 598 * sp == NULL, error == -EINVAL discard packet w/o error 599 * sp == NULL, error != 0 discard packet, report error 600 */ 601 if (sp != NULL) { 602 /* Loop detection, check if ipsec processing already done */ 603 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 604 for (mtag = m_tag_first(m); mtag != NULL; 605 mtag = m_tag_next(m, mtag)) { 606 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 607 continue; 608 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 609 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 610 continue; 611 /* 612 * Check if policy has an SA associated with it. 613 * This can happen when an SP has yet to acquire 614 * an SA; e.g. on first reference. If it occurs, 615 * then we let ipsec4_process_packet do its thing. 616 */ 617 if (sp->req->sav == NULL) 618 break; 619 tdbi = (struct tdb_ident *)(mtag + 1); 620 if (tdbi->spi == sp->req->sav->spi && 621 tdbi->proto == sp->req->sav->sah->saidx.proto && 622 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 623 sizeof(union sockaddr_union)) == 0) { 624 /* 625 * No IPsec processing is needed, free 626 * reference to SP. 627 * 628 * NB: null pointer to avoid free at 629 * done: below. 630 */ 631 KEY_FREESP(&sp), sp = NULL; 632 splx(s); 633 goto spd_done; 634 } 635 } 636 637 /* 638 * Do delayed checksums now because we send before 639 * this is done in the normal processing path. 640 */ 641 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 642 in_delayed_cksum(m); 643 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 644 } 645 646 ip->ip_len = htons(ip->ip_len); 647 ip->ip_off = htons(ip->ip_off); 648 649 /* NB: callee frees mbuf */ 650 error = ipsec4_process_packet(m, sp->req, flags, 0); 651 /* 652 * Preserve KAME behaviour: ENOENT can be returned 653 * when an SA acquire is in progress. Don't propagate 654 * this to user-level; it confuses applications. 655 * 656 * XXX this will go away when the SADB is redone. 657 */ 658 if (error == ENOENT) 659 error = 0; 660 splx(s); 661 goto done; 662 } else { 663 splx(s); 664 665 if (error != 0) { 666 /* 667 * Hack: -EINVAL is used to signal that a packet 668 * should be silently discarded. This is typically 669 * because we asked key management for an SA and 670 * it was delayed (e.g. kicked up to IKE). 671 */ 672 if (error == -EINVAL) 673 error = 0; 674 goto bad; 675 } else { 676 /* No IPsec processing for this packet. */ 677 } 678 #ifdef notyet 679 /* 680 * If deferred crypto processing is needed, check that 681 * the interface supports it. 682 */ 683 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 684 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 685 /* notify IPsec to do its own crypto */ 686 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 687 error = EHOSTUNREACH; 688 goto bad; 689 } 690 #endif 691 } 692 spd_done: 693 #endif /* FAST_IPSEC */ 694 /* 695 * IpHack's section. 696 * - Xlate: translate packet's addr/port (NAT). 697 * - Firewall: deny/allow/etc. 698 * - Wrap: fake packet's addr/port <unimpl.> 699 * - Encapsulate: put it in another IP and send out. <unimp.> 700 */ 701 702 /* 703 * Run through list of hooks for output packets. 704 */ 705 if (pfil_has_hooks(&inet_pfil_hook)) { 706 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 707 if (error != 0 || m == NULL) 708 goto done; 709 ip = mtod(m, struct ip *); 710 } 711 712 /* 713 * Check with the firewall... 714 * but not if we are already being fwd'd from a firewall. 715 */ 716 if (fw_enable && IPFW_LOADED && !args.next_hop) { 717 struct sockaddr_in *old = dst; 718 719 args.m = m; 720 args.next_hop = dst; 721 args.oif = ifp; 722 off = ip_fw_chk_ptr(&args); 723 m = args.m; 724 dst = args.next_hop; 725 726 /* 727 * On return we must do the following: 728 * m == NULL -> drop the pkt (old interface, deprecated) 729 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 730 * 1<=off<= 0xffff -> DIVERT 731 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 732 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 733 * dst != old -> IPFIREWALL_FORWARD 734 * off==0, dst==old -> accept 735 * If some of the above modules are not compiled in, then 736 * we should't have to check the corresponding condition 737 * (because the ipfw control socket should not accept 738 * unsupported rules), but better play safe and drop 739 * packets in case of doubt. 740 */ 741 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 742 if (m) 743 m_freem(m); 744 error = EACCES; 745 goto done; 746 } 747 ip = mtod(m, struct ip *); 748 if (off == 0 && dst == old) /* common case */ 749 goto pass; 750 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG)) { 751 /* 752 * pass the pkt to dummynet. Need to include 753 * pipe number, m, ifp, ro, dst because these are 754 * not recomputed in the next pass. 755 * All other parameters have been already used and 756 * so they are not needed anymore. 757 * XXX note: if the ifp or ro entry are deleted 758 * while a pkt is in dummynet, we are in trouble! 759 */ 760 args.ro = ro; 761 args.dst = dst; 762 args.flags = flags; 763 764 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 765 &args); 766 goto done; 767 } 768 #ifdef IPDIVERT 769 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) { 770 struct mbuf *clone = NULL; 771 772 /* Clone packet if we're doing a 'tee' */ 773 if ((off & IP_FW_PORT_TEE_FLAG)) 774 clone = m_dup(m, MB_DONTWAIT); 775 776 /* 777 * XXX 778 * delayed checksums are not currently compatible 779 * with divert sockets. 780 */ 781 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 782 in_delayed_cksum(m); 783 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 784 } 785 786 /* Restore packet header fields to original values */ 787 ip->ip_len = htons(ip->ip_len); 788 ip->ip_off = htons(ip->ip_off); 789 790 /* Deliver packet to divert input routine */ 791 divert_packet(m, 0, off & 0xffff, args.divert_rule); 792 793 /* If 'tee', continue with original packet */ 794 if (clone != NULL) { 795 m = clone; 796 ip = mtod(m, struct ip *); 797 goto pass; 798 } 799 goto done; 800 } 801 #endif 802 803 /* IPFIREWALL_FORWARD */ 804 /* 805 * Check dst to make sure it is directly reachable on the 806 * interface we previously thought it was. 807 * If it isn't (which may be likely in some situations) we have 808 * to re-route it (ie, find a route for the next-hop and the 809 * associated interface) and set them here. This is nested 810 * forwarding which in most cases is undesirable, except where 811 * such control is nigh impossible. So we do it here. 812 * And I'm babbling. 813 */ 814 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 815 #if 0 816 /* 817 * XXX To improve readability, this block should be 818 * changed into a function call as below: 819 */ 820 error = ip_ipforward(&m, &dst, &ifp); 821 if (error) 822 goto bad; 823 if (m == NULL) /* ip_input consumed the mbuf */ 824 goto done; 825 #else 826 struct in_ifaddr *ia; 827 828 /* 829 * XXX sro_fwd below is static, and a pointer 830 * to it gets passed to routines downstream. 831 * This could have surprisingly bad results in 832 * practice, because its content is overwritten 833 * by subsequent packets. 834 */ 835 /* There must be a better way to do this next line... */ 836 static struct route sro_fwd; 837 struct route *ro_fwd = &sro_fwd; 838 839 #if 0 840 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 841 dst->sin_addr, "\n"); 842 #endif 843 844 /* 845 * We need to figure out if we have been forwarded 846 * to a local socket. If so, then we should somehow 847 * "loop back" to ip_input, and get directed to the 848 * PCB as if we had received this packet. This is 849 * because it may be dificult to identify the packets 850 * you want to forward until they are being output 851 * and have selected an interface. (e.g. locally 852 * initiated packets) If we used the loopback inteface, 853 * we would not be able to control what happens 854 * as the packet runs through ip_input() as 855 * it is done through a ISR. 856 */ 857 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr), 858 ia_hash) { 859 /* 860 * If the addr to forward to is one 861 * of ours, we pretend to 862 * be the destination for this packet. 863 */ 864 if (IA_SIN(ia)->sin_addr.s_addr == 865 dst->sin_addr.s_addr) 866 break; 867 } 868 if (ia != NULL) { /* tell ip_input "dont filter" */ 869 struct m_hdr tag; 870 871 tag.mh_type = MT_TAG; 872 tag.mh_flags = PACKET_TAG_IPFORWARD; 873 tag.mh_data = (caddr_t)args.next_hop; 874 tag.mh_next = m; 875 876 if (m->m_pkthdr.rcvif == NULL) 877 m->m_pkthdr.rcvif = ifunit("lo0"); 878 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 879 m->m_pkthdr.csum_flags |= 880 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 881 m0->m_pkthdr.csum_data = 0xffff; 882 } 883 m->m_pkthdr.csum_flags |= 884 CSUM_IP_CHECKED | CSUM_IP_VALID; 885 ip->ip_len = htons(ip->ip_len); 886 ip->ip_off = htons(ip->ip_off); 887 ip_input((struct mbuf *)&tag); 888 goto done; 889 } 890 /* Some of the logic for this was nicked from above. 891 * 892 * This rewrites the cached route in a local PCB. 893 * Is this what we want to do? 894 */ 895 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst); 896 ro_fwd->ro_rt = NULL; 897 898 rtalloc_ign(ro_fwd, RTF_PRCLONING); 899 if (ro_fwd->ro_rt == NULL) { 900 ipstat.ips_noroute++; 901 error = EHOSTUNREACH; 902 goto bad; 903 } 904 905 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 906 ifp = ro_fwd->ro_rt->rt_ifp; 907 ro_fwd->ro_rt->rt_use++; 908 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 909 dst = (struct sockaddr_in *) 910 ro_fwd->ro_rt->rt_gateway; 911 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 912 isbroadcast = 913 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 914 else 915 isbroadcast = in_broadcast(dst->sin_addr, ifp); 916 if (ro->ro_rt != NULL) 917 rtfree(ro->ro_rt); 918 ro->ro_rt = ro_fwd->ro_rt; 919 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 920 921 #endif /* ... block to be put into a function */ 922 /* 923 * If we added a default src ip earlier, 924 * which would have been gotten from the-then 925 * interface, do it again, from the new one. 926 */ 927 if (src_was_INADDR_ANY) 928 ip->ip_src = IA_SIN(ia)->sin_addr; 929 goto pass ; 930 } 931 932 /* 933 * if we get here, none of the above matches, and 934 * we have to drop the pkt 935 */ 936 m_freem(m); 937 error = EACCES; /* not sure this is the right error msg */ 938 goto done; 939 } 940 941 pass: 942 /* 127/8 must not appear on wire - RFC1122. */ 943 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 944 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 945 if (!(ifp->if_flags & IFF_LOOPBACK)) { 946 ipstat.ips_badaddr++; 947 error = EADDRNOTAVAIL; 948 goto bad; 949 } 950 } 951 952 m->m_pkthdr.csum_flags |= CSUM_IP; 953 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 954 if (sw_csum & CSUM_DELAY_DATA) { 955 in_delayed_cksum(m); 956 sw_csum &= ~CSUM_DELAY_DATA; 957 } 958 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 959 960 /* 961 * If small enough for interface, or the interface will take 962 * care of the fragmentation for us, can just send directly. 963 */ 964 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 965 !(ip->ip_off & IP_DF))) { 966 ip->ip_len = htons(ip->ip_len); 967 ip->ip_off = htons(ip->ip_off); 968 ip->ip_sum = 0; 969 if (sw_csum & CSUM_DELAY_IP) { 970 if (ip->ip_vhl == IP_VHL_BORING) { 971 ip->ip_sum = in_cksum_hdr(ip); 972 } else { 973 ip->ip_sum = in_cksum(m, hlen); 974 } 975 } 976 977 /* Record statistics for this interface address. */ 978 if (!(flags & IP_FORWARDING) && ia) { 979 ia->ia_ifa.if_opackets++; 980 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 981 } 982 983 #ifdef IPSEC 984 /* clean ipsec history once it goes out of the node */ 985 ipsec_delaux(m); 986 #endif 987 988 #ifdef MBUF_STRESS_TEST 989 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 990 struct mbuf *m1, *m2; 991 int length, tmp; 992 993 tmp = length = m->m_pkthdr.len; 994 995 while ((length -= mbuf_frag_size) >= 1) { 996 m1 = m_split(m, length, MB_DONTWAIT); 997 if (m1 == NULL) 998 break; 999 m1->m_flags &= ~M_PKTHDR; 1000 m2 = m; 1001 while (m2->m_next != NULL) 1002 m2 = m2->m_next; 1003 m2->m_next = m1; 1004 } 1005 m->m_pkthdr.len = tmp; 1006 } 1007 #endif 1008 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, 1009 ro->ro_rt); 1010 goto done; 1011 } 1012 1013 if (ip->ip_off & IP_DF) { 1014 error = EMSGSIZE; 1015 /* 1016 * This case can happen if the user changed the MTU 1017 * of an interface after enabling IP on it. Because 1018 * most netifs don't keep track of routes pointing to 1019 * them, there is no way for one to update all its 1020 * routes when the MTU is changed. 1021 */ 1022 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1023 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1024 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1025 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1026 } 1027 ipstat.ips_cantfrag++; 1028 goto bad; 1029 } 1030 1031 /* 1032 * Too large for interface; fragment if possible. If successful, 1033 * on return, m will point to a list of packets to be sent. 1034 */ 1035 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1036 if (error) 1037 goto bad; 1038 for (; m; m = m0) { 1039 m0 = m->m_nextpkt; 1040 m->m_nextpkt = NULL; 1041 #ifdef IPSEC 1042 /* clean ipsec history once it goes out of the node */ 1043 ipsec_delaux(m); 1044 #endif 1045 if (error == 0) { 1046 /* Record statistics for this interface address. */ 1047 if (ia != NULL) { 1048 ia->ia_ifa.if_opackets++; 1049 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1050 } 1051 error = (*ifp->if_output)(ifp, m, 1052 (struct sockaddr *)dst, 1053 ro->ro_rt); 1054 } else 1055 m_freem(m); 1056 } 1057 1058 if (error == 0) 1059 ipstat.ips_fragmented++; 1060 1061 done: 1062 if (ro == &iproute && ro->ro_rt != NULL) { 1063 RTFREE(ro->ro_rt); 1064 ro->ro_rt = NULL; 1065 } 1066 #ifdef IPSEC 1067 if (sp != NULL) { 1068 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1069 printf("DP ip_output call free SP:%p\n", sp)); 1070 key_freesp(sp); 1071 } 1072 #endif 1073 #ifdef FAST_IPSEC 1074 if (sp != NULL) 1075 KEY_FREESP(&sp); 1076 #endif 1077 return (error); 1078 bad: 1079 m_freem(m); 1080 goto done; 1081 } 1082 1083 /* 1084 * Create a chain of fragments which fit the given mtu. m_frag points to the 1085 * mbuf to be fragmented; on return it points to the chain with the fragments. 1086 * Return 0 if no error. If error, m_frag may contain a partially built 1087 * chain of fragments that should be freed by the caller. 1088 * 1089 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1090 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1091 */ 1092 int 1093 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1094 u_long if_hwassist_flags, int sw_csum) 1095 { 1096 int error = 0; 1097 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1098 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1099 int off; 1100 struct mbuf *m0 = *m_frag; /* the original packet */ 1101 int firstlen; 1102 struct mbuf **mnext; 1103 int nfrags; 1104 1105 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1106 ipstat.ips_cantfrag++; 1107 return EMSGSIZE; 1108 } 1109 1110 /* 1111 * Must be able to put at least 8 bytes per fragment. 1112 */ 1113 if (len < 8) 1114 return EMSGSIZE; 1115 1116 /* 1117 * If the interface will not calculate checksums on 1118 * fragmented packets, then do it here. 1119 */ 1120 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1121 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1122 in_delayed_cksum(m0); 1123 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1124 } 1125 1126 if (len > PAGE_SIZE) { 1127 /* 1128 * Fragment large datagrams such that each segment 1129 * contains a multiple of PAGE_SIZE amount of data, 1130 * plus headers. This enables a receiver to perform 1131 * page-flipping zero-copy optimizations. 1132 * 1133 * XXX When does this help given that sender and receiver 1134 * could have different page sizes, and also mtu could 1135 * be less than the receiver's page size ? 1136 */ 1137 int newlen; 1138 struct mbuf *m; 1139 1140 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1141 off += m->m_len; 1142 1143 /* 1144 * firstlen (off - hlen) must be aligned on an 1145 * 8-byte boundary 1146 */ 1147 if (off < hlen) 1148 goto smart_frag_failure; 1149 off = ((off - hlen) & ~7) + hlen; 1150 newlen = (~PAGE_MASK) & mtu; 1151 if ((newlen + sizeof(struct ip)) > mtu) { 1152 /* we failed, go back the default */ 1153 smart_frag_failure: 1154 newlen = len; 1155 off = hlen + len; 1156 } 1157 len = newlen; 1158 1159 } else { 1160 off = hlen + len; 1161 } 1162 1163 firstlen = off - hlen; 1164 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1165 1166 /* 1167 * Loop through length of segment after first fragment, 1168 * make new header and copy data of each part and link onto chain. 1169 * Here, m0 is the original packet, m is the fragment being created. 1170 * The fragments are linked off the m_nextpkt of the original 1171 * packet, which after processing serves as the first fragment. 1172 */ 1173 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1174 struct ip *mhip; /* ip header on the fragment */ 1175 struct mbuf *m; 1176 int mhlen = sizeof(struct ip); 1177 1178 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1179 if (m == NULL) { 1180 error = ENOBUFS; 1181 ipstat.ips_odropped++; 1182 goto done; 1183 } 1184 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1185 /* 1186 * In the first mbuf, leave room for the link header, then 1187 * copy the original IP header including options. The payload 1188 * goes into an additional mbuf chain returned by m_copy(). 1189 */ 1190 m->m_data += max_linkhdr; 1191 mhip = mtod(m, struct ip *); 1192 *mhip = *ip; 1193 if (hlen > sizeof(struct ip)) { 1194 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1195 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1196 } 1197 m->m_len = mhlen; 1198 /* XXX do we need to add ip->ip_off below ? */ 1199 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1200 if (off + len >= ip->ip_len) { /* last fragment */ 1201 len = ip->ip_len - off; 1202 m->m_flags |= M_LASTFRAG; 1203 } else 1204 mhip->ip_off |= IP_MF; 1205 mhip->ip_len = htons((u_short)(len + mhlen)); 1206 m->m_next = m_copy(m0, off, len); 1207 if (m->m_next == NULL) { /* copy failed */ 1208 m_free(m); 1209 error = ENOBUFS; /* ??? */ 1210 ipstat.ips_odropped++; 1211 goto done; 1212 } 1213 m->m_pkthdr.len = mhlen + len; 1214 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1215 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1216 mhip->ip_off = htons(mhip->ip_off); 1217 mhip->ip_sum = 0; 1218 if (sw_csum & CSUM_DELAY_IP) 1219 mhip->ip_sum = in_cksum(m, mhlen); 1220 *mnext = m; 1221 mnext = &m->m_nextpkt; 1222 } 1223 ipstat.ips_ofragments += nfrags; 1224 1225 /* set first marker for fragment chain */ 1226 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1227 m0->m_pkthdr.csum_data = nfrags; 1228 1229 /* 1230 * Update first fragment by trimming what's been copied out 1231 * and updating header. 1232 */ 1233 m_adj(m0, hlen + firstlen - ip->ip_len); 1234 m0->m_pkthdr.len = hlen + firstlen; 1235 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1236 ip->ip_off |= IP_MF; 1237 ip->ip_off = htons(ip->ip_off); 1238 ip->ip_sum = 0; 1239 if (sw_csum & CSUM_DELAY_IP) 1240 ip->ip_sum = in_cksum(m0, hlen); 1241 1242 done: 1243 *m_frag = m0; 1244 return error; 1245 } 1246 1247 void 1248 in_delayed_cksum(struct mbuf *m) 1249 { 1250 struct ip *ip; 1251 u_short csum, offset; 1252 1253 ip = mtod(m, struct ip *); 1254 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1255 csum = in_cksum_skip(m, ip->ip_len, offset); 1256 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1257 csum = 0xffff; 1258 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1259 1260 if (offset + sizeof(u_short) > m->m_len) { 1261 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1262 m->m_len, offset, ip->ip_p); 1263 /* 1264 * XXX 1265 * this shouldn't happen, but if it does, the 1266 * correct behavior may be to insert the checksum 1267 * in the existing chain instead of rearranging it. 1268 */ 1269 m = m_pullup(m, offset + sizeof(u_short)); 1270 } 1271 *(u_short *)(m->m_data + offset) = csum; 1272 } 1273 1274 /* 1275 * Insert IP options into preformed packet. 1276 * Adjust IP destination as required for IP source routing, 1277 * as indicated by a non-zero in_addr at the start of the options. 1278 * 1279 * XXX This routine assumes that the packet has no options in place. 1280 */ 1281 static struct mbuf * 1282 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1283 { 1284 struct ipoption *p = mtod(opt, struct ipoption *); 1285 struct mbuf *n; 1286 struct ip *ip = mtod(m, struct ip *); 1287 unsigned optlen; 1288 1289 optlen = opt->m_len - sizeof p->ipopt_dst; 1290 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1291 *phlen = 0; 1292 return (m); /* XXX should fail */ 1293 } 1294 if (p->ipopt_dst.s_addr) 1295 ip->ip_dst = p->ipopt_dst; 1296 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1297 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1298 if (n == NULL) { 1299 *phlen = 0; 1300 return (m); 1301 } 1302 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 1303 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1304 m->m_len -= sizeof(struct ip); 1305 m->m_data += sizeof(struct ip); 1306 n->m_next = m; 1307 m = n; 1308 m->m_len = optlen + sizeof(struct ip); 1309 m->m_data += max_linkhdr; 1310 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1311 } else { 1312 m->m_data -= optlen; 1313 m->m_len += optlen; 1314 m->m_pkthdr.len += optlen; 1315 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1316 } 1317 ip = mtod(m, struct ip *); 1318 bcopy(p->ipopt_list, ip + 1, optlen); 1319 *phlen = sizeof(struct ip) + optlen; 1320 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1321 ip->ip_len += optlen; 1322 return (m); 1323 } 1324 1325 /* 1326 * Copy options from ip to jp, 1327 * omitting those not copied during fragmentation. 1328 */ 1329 int 1330 ip_optcopy(struct ip *ip, struct ip *jp) 1331 { 1332 u_char *cp, *dp; 1333 int opt, optlen, cnt; 1334 1335 cp = (u_char *)(ip + 1); 1336 dp = (u_char *)(jp + 1); 1337 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1338 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1339 opt = cp[0]; 1340 if (opt == IPOPT_EOL) 1341 break; 1342 if (opt == IPOPT_NOP) { 1343 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1344 *dp++ = IPOPT_NOP; 1345 optlen = 1; 1346 continue; 1347 } 1348 1349 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1350 ("ip_optcopy: malformed ipv4 option")); 1351 optlen = cp[IPOPT_OLEN]; 1352 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1353 ("ip_optcopy: malformed ipv4 option")); 1354 1355 /* bogus lengths should have been caught by ip_dooptions */ 1356 if (optlen > cnt) 1357 optlen = cnt; 1358 if (IPOPT_COPIED(opt)) { 1359 bcopy(cp, dp, optlen); 1360 dp += optlen; 1361 } 1362 } 1363 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1364 *dp++ = IPOPT_EOL; 1365 return (optlen); 1366 } 1367 1368 /* 1369 * IP socket option processing. 1370 */ 1371 int 1372 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1373 { 1374 struct inpcb *inp = sotoinpcb(so); 1375 int error, optval; 1376 1377 error = optval = 0; 1378 if (sopt->sopt_level != IPPROTO_IP) { 1379 return (EINVAL); 1380 } 1381 1382 switch (sopt->sopt_dir) { 1383 case SOPT_SET: 1384 switch (sopt->sopt_name) { 1385 case IP_OPTIONS: 1386 #ifdef notyet 1387 case IP_RETOPTS: 1388 #endif 1389 { 1390 struct mbuf *m; 1391 if (sopt->sopt_valsize > MLEN) { 1392 error = EMSGSIZE; 1393 break; 1394 } 1395 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1396 if (m == NULL) { 1397 error = ENOBUFS; 1398 break; 1399 } 1400 m->m_len = sopt->sopt_valsize; 1401 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1402 m->m_len); 1403 1404 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1405 m)); 1406 } 1407 1408 case IP_TOS: 1409 case IP_TTL: 1410 case IP_RECVOPTS: 1411 case IP_RECVRETOPTS: 1412 case IP_RECVDSTADDR: 1413 case IP_RECVIF: 1414 case IP_FAITH: 1415 error = sooptcopyin(sopt, &optval, sizeof optval, 1416 sizeof optval); 1417 if (error) 1418 break; 1419 1420 switch (sopt->sopt_name) { 1421 case IP_TOS: 1422 inp->inp_ip_tos = optval; 1423 break; 1424 1425 case IP_TTL: 1426 inp->inp_ip_ttl = optval; 1427 break; 1428 #define OPTSET(bit) \ 1429 if (optval) \ 1430 inp->inp_flags |= bit; \ 1431 else \ 1432 inp->inp_flags &= ~bit; 1433 1434 case IP_RECVOPTS: 1435 OPTSET(INP_RECVOPTS); 1436 break; 1437 1438 case IP_RECVRETOPTS: 1439 OPTSET(INP_RECVRETOPTS); 1440 break; 1441 1442 case IP_RECVDSTADDR: 1443 OPTSET(INP_RECVDSTADDR); 1444 break; 1445 1446 case IP_RECVIF: 1447 OPTSET(INP_RECVIF); 1448 break; 1449 1450 case IP_FAITH: 1451 OPTSET(INP_FAITH); 1452 break; 1453 } 1454 break; 1455 #undef OPTSET 1456 1457 case IP_MULTICAST_IF: 1458 case IP_MULTICAST_VIF: 1459 case IP_MULTICAST_TTL: 1460 case IP_MULTICAST_LOOP: 1461 case IP_ADD_MEMBERSHIP: 1462 case IP_DROP_MEMBERSHIP: 1463 error = ip_setmoptions(sopt, &inp->inp_moptions); 1464 break; 1465 1466 case IP_PORTRANGE: 1467 error = sooptcopyin(sopt, &optval, sizeof optval, 1468 sizeof optval); 1469 if (error) 1470 break; 1471 1472 switch (optval) { 1473 case IP_PORTRANGE_DEFAULT: 1474 inp->inp_flags &= ~(INP_LOWPORT); 1475 inp->inp_flags &= ~(INP_HIGHPORT); 1476 break; 1477 1478 case IP_PORTRANGE_HIGH: 1479 inp->inp_flags &= ~(INP_LOWPORT); 1480 inp->inp_flags |= INP_HIGHPORT; 1481 break; 1482 1483 case IP_PORTRANGE_LOW: 1484 inp->inp_flags &= ~(INP_HIGHPORT); 1485 inp->inp_flags |= INP_LOWPORT; 1486 break; 1487 1488 default: 1489 error = EINVAL; 1490 break; 1491 } 1492 break; 1493 1494 #if defined(IPSEC) || defined(FAST_IPSEC) 1495 case IP_IPSEC_POLICY: 1496 { 1497 caddr_t req; 1498 size_t len = 0; 1499 int priv; 1500 struct mbuf *m; 1501 int optname; 1502 1503 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1504 break; 1505 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1506 break; 1507 priv = (sopt->sopt_td != NULL && 1508 suser(sopt->sopt_td) != 0) ? 0 : 1; 1509 req = mtod(m, caddr_t); 1510 len = m->m_len; 1511 optname = sopt->sopt_name; 1512 error = ipsec4_set_policy(inp, optname, req, len, priv); 1513 m_freem(m); 1514 break; 1515 } 1516 #endif /*IPSEC*/ 1517 1518 default: 1519 error = ENOPROTOOPT; 1520 break; 1521 } 1522 break; 1523 1524 case SOPT_GET: 1525 switch (sopt->sopt_name) { 1526 case IP_OPTIONS: 1527 case IP_RETOPTS: 1528 if (inp->inp_options) 1529 error = sooptcopyout(sopt, 1530 mtod(inp->inp_options, 1531 char *), 1532 inp->inp_options->m_len); 1533 else 1534 sopt->sopt_valsize = 0; 1535 break; 1536 1537 case IP_TOS: 1538 case IP_TTL: 1539 case IP_RECVOPTS: 1540 case IP_RECVRETOPTS: 1541 case IP_RECVDSTADDR: 1542 case IP_RECVIF: 1543 case IP_PORTRANGE: 1544 case IP_FAITH: 1545 switch (sopt->sopt_name) { 1546 1547 case IP_TOS: 1548 optval = inp->inp_ip_tos; 1549 break; 1550 1551 case IP_TTL: 1552 optval = inp->inp_ip_ttl; 1553 break; 1554 1555 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1556 1557 case IP_RECVOPTS: 1558 optval = OPTBIT(INP_RECVOPTS); 1559 break; 1560 1561 case IP_RECVRETOPTS: 1562 optval = OPTBIT(INP_RECVRETOPTS); 1563 break; 1564 1565 case IP_RECVDSTADDR: 1566 optval = OPTBIT(INP_RECVDSTADDR); 1567 break; 1568 1569 case IP_RECVIF: 1570 optval = OPTBIT(INP_RECVIF); 1571 break; 1572 1573 case IP_PORTRANGE: 1574 if (inp->inp_flags & INP_HIGHPORT) 1575 optval = IP_PORTRANGE_HIGH; 1576 else if (inp->inp_flags & INP_LOWPORT) 1577 optval = IP_PORTRANGE_LOW; 1578 else 1579 optval = 0; 1580 break; 1581 1582 case IP_FAITH: 1583 optval = OPTBIT(INP_FAITH); 1584 break; 1585 } 1586 error = sooptcopyout(sopt, &optval, sizeof optval); 1587 break; 1588 1589 case IP_MULTICAST_IF: 1590 case IP_MULTICAST_VIF: 1591 case IP_MULTICAST_TTL: 1592 case IP_MULTICAST_LOOP: 1593 case IP_ADD_MEMBERSHIP: 1594 case IP_DROP_MEMBERSHIP: 1595 error = ip_getmoptions(sopt, inp->inp_moptions); 1596 break; 1597 1598 #if defined(IPSEC) || defined(FAST_IPSEC) 1599 case IP_IPSEC_POLICY: 1600 { 1601 struct mbuf *m = NULL; 1602 caddr_t req = NULL; 1603 size_t len = 0; 1604 1605 if (m != NULL) { 1606 req = mtod(m, caddr_t); 1607 len = m->m_len; 1608 } 1609 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1610 if (error == 0) 1611 error = soopt_mcopyout(sopt, m); /* XXX */ 1612 if (error == 0) 1613 m_freem(m); 1614 break; 1615 } 1616 #endif /*IPSEC*/ 1617 1618 default: 1619 error = ENOPROTOOPT; 1620 break; 1621 } 1622 break; 1623 } 1624 return (error); 1625 } 1626 1627 /* 1628 * Set up IP options in pcb for insertion in output packets. 1629 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1630 * with destination address if source routed. 1631 */ 1632 static int 1633 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1634 { 1635 int cnt, optlen; 1636 u_char *cp; 1637 u_char opt; 1638 1639 /* turn off any old options */ 1640 if (*pcbopt) 1641 m_free(*pcbopt); 1642 *pcbopt = 0; 1643 if (m == NULL || m->m_len == 0) { 1644 /* 1645 * Only turning off any previous options. 1646 */ 1647 if (m != NULL) 1648 m_free(m); 1649 return (0); 1650 } 1651 1652 if (m->m_len % sizeof(int32_t)) 1653 goto bad; 1654 /* 1655 * IP first-hop destination address will be stored before 1656 * actual options; move other options back 1657 * and clear it when none present. 1658 */ 1659 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1660 goto bad; 1661 cnt = m->m_len; 1662 m->m_len += sizeof(struct in_addr); 1663 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1664 ovbcopy(mtod(m, caddr_t), cp, cnt); 1665 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1666 1667 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1668 opt = cp[IPOPT_OPTVAL]; 1669 if (opt == IPOPT_EOL) 1670 break; 1671 if (opt == IPOPT_NOP) 1672 optlen = 1; 1673 else { 1674 if (cnt < IPOPT_OLEN + sizeof *cp) 1675 goto bad; 1676 optlen = cp[IPOPT_OLEN]; 1677 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1678 goto bad; 1679 } 1680 switch (opt) { 1681 1682 default: 1683 break; 1684 1685 case IPOPT_LSRR: 1686 case IPOPT_SSRR: 1687 /* 1688 * user process specifies route as: 1689 * ->A->B->C->D 1690 * D must be our final destination (but we can't 1691 * check that since we may not have connected yet). 1692 * A is first hop destination, which doesn't appear in 1693 * actual IP option, but is stored before the options. 1694 */ 1695 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1696 goto bad; 1697 m->m_len -= sizeof(struct in_addr); 1698 cnt -= sizeof(struct in_addr); 1699 optlen -= sizeof(struct in_addr); 1700 cp[IPOPT_OLEN] = optlen; 1701 /* 1702 * Move first hop before start of options. 1703 */ 1704 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1705 sizeof(struct in_addr)); 1706 /* 1707 * Then copy rest of options back 1708 * to close up the deleted entry. 1709 */ 1710 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1711 &cp[IPOPT_OFFSET+1], 1712 cnt - (IPOPT_MINOFF - 1)); 1713 break; 1714 } 1715 } 1716 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1717 goto bad; 1718 *pcbopt = m; 1719 return (0); 1720 1721 bad: 1722 m_free(m); 1723 return (EINVAL); 1724 } 1725 1726 /* 1727 * XXX 1728 * The whole multicast option thing needs to be re-thought. 1729 * Several of these options are equally applicable to non-multicast 1730 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1731 * standard option (IP_TTL). 1732 */ 1733 1734 /* 1735 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1736 */ 1737 static struct ifnet * 1738 ip_multicast_if(struct in_addr *a, int *ifindexp) 1739 { 1740 int ifindex; 1741 struct ifnet *ifp; 1742 1743 if (ifindexp) 1744 *ifindexp = 0; 1745 if (ntohl(a->s_addr) >> 24 == 0) { 1746 ifindex = ntohl(a->s_addr) & 0xffffff; 1747 if (ifindex < 0 || if_index < ifindex) 1748 return NULL; 1749 ifp = ifindex2ifnet[ifindex]; 1750 if (ifindexp) 1751 *ifindexp = ifindex; 1752 } else { 1753 INADDR_TO_IFP(*a, ifp); 1754 } 1755 return ifp; 1756 } 1757 1758 /* 1759 * Set the IP multicast options in response to user setsockopt(). 1760 */ 1761 static int 1762 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1763 { 1764 int error = 0; 1765 int i; 1766 struct in_addr addr; 1767 struct ip_mreq mreq; 1768 struct ifnet *ifp; 1769 struct ip_moptions *imo = *imop; 1770 struct sockaddr_in *dst; 1771 int ifindex; 1772 int s; 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 s = splimp(); 1831 ifp = ip_multicast_if(&addr, &ifindex); 1832 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1833 splx(s); 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 splx(s); 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 s = splimp(); 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 route ro; 1915 1916 bzero(&ro, sizeof ro); 1917 dst = (struct sockaddr_in *)&ro.ro_dst; 1918 dst->sin_len = sizeof *dst; 1919 dst->sin_family = AF_INET; 1920 dst->sin_addr = mreq.imr_multiaddr; 1921 rtalloc(&ro); 1922 if (ro.ro_rt == NULL) { 1923 error = EADDRNOTAVAIL; 1924 splx(s); 1925 break; 1926 } 1927 --ro.ro_rt->rt_refcnt; 1928 ifp = ro.ro_rt->rt_ifp; 1929 } 1930 else { 1931 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1932 } 1933 1934 /* 1935 * See if we found an interface, and confirm that it 1936 * supports multicast. 1937 */ 1938 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1939 error = EADDRNOTAVAIL; 1940 splx(s); 1941 break; 1942 } 1943 /* 1944 * See if the membership already exists or if all the 1945 * membership slots are full. 1946 */ 1947 for (i = 0; i < imo->imo_num_memberships; ++i) { 1948 if (imo->imo_membership[i]->inm_ifp == ifp && 1949 imo->imo_membership[i]->inm_addr.s_addr 1950 == mreq.imr_multiaddr.s_addr) 1951 break; 1952 } 1953 if (i < imo->imo_num_memberships) { 1954 error = EADDRINUSE; 1955 splx(s); 1956 break; 1957 } 1958 if (i == IP_MAX_MEMBERSHIPS) { 1959 error = ETOOMANYREFS; 1960 splx(s); 1961 break; 1962 } 1963 /* 1964 * Everything looks good; add a new record to the multicast 1965 * address list for the given interface. 1966 */ 1967 if ((imo->imo_membership[i] = 1968 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1969 error = ENOBUFS; 1970 splx(s); 1971 break; 1972 } 1973 ++imo->imo_num_memberships; 1974 splx(s); 1975 break; 1976 1977 case IP_DROP_MEMBERSHIP: 1978 /* 1979 * Drop a multicast group membership. 1980 * Group must be a valid IP multicast address. 1981 */ 1982 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1983 if (error) 1984 break; 1985 1986 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1987 error = EINVAL; 1988 break; 1989 } 1990 1991 s = splimp(); 1992 /* 1993 * If an interface address was specified, get a pointer 1994 * to its ifnet structure. 1995 */ 1996 if (mreq.imr_interface.s_addr == INADDR_ANY) 1997 ifp = NULL; 1998 else { 1999 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2000 if (ifp == NULL) { 2001 error = EADDRNOTAVAIL; 2002 splx(s); 2003 break; 2004 } 2005 } 2006 /* 2007 * Find the membership in the membership array. 2008 */ 2009 for (i = 0; i < imo->imo_num_memberships; ++i) { 2010 if ((ifp == NULL || 2011 imo->imo_membership[i]->inm_ifp == ifp) && 2012 imo->imo_membership[i]->inm_addr.s_addr == 2013 mreq.imr_multiaddr.s_addr) 2014 break; 2015 } 2016 if (i == imo->imo_num_memberships) { 2017 error = EADDRNOTAVAIL; 2018 splx(s); 2019 break; 2020 } 2021 /* 2022 * Give up the multicast address record to which the 2023 * membership points. 2024 */ 2025 in_delmulti(imo->imo_membership[i]); 2026 /* 2027 * Remove the gap in the membership array. 2028 */ 2029 for (++i; i < imo->imo_num_memberships; ++i) 2030 imo->imo_membership[i-1] = imo->imo_membership[i]; 2031 --imo->imo_num_memberships; 2032 splx(s); 2033 break; 2034 2035 default: 2036 error = EOPNOTSUPP; 2037 break; 2038 } 2039 2040 /* 2041 * If all options have default values, no need to keep the mbuf. 2042 */ 2043 if (imo->imo_multicast_ifp == NULL && 2044 imo->imo_multicast_vif == -1 && 2045 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2046 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2047 imo->imo_num_memberships == 0) { 2048 free(*imop, M_IPMOPTS); 2049 *imop = NULL; 2050 } 2051 2052 return (error); 2053 } 2054 2055 /* 2056 * Return the IP multicast options in response to user getsockopt(). 2057 */ 2058 static int 2059 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2060 { 2061 struct in_addr addr; 2062 struct in_ifaddr *ia; 2063 int error, optval; 2064 u_char coptval; 2065 2066 error = 0; 2067 switch (sopt->sopt_name) { 2068 case IP_MULTICAST_VIF: 2069 if (imo != NULL) 2070 optval = imo->imo_multicast_vif; 2071 else 2072 optval = -1; 2073 error = sooptcopyout(sopt, &optval, sizeof optval); 2074 break; 2075 2076 case IP_MULTICAST_IF: 2077 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2078 addr.s_addr = INADDR_ANY; 2079 else if (imo->imo_multicast_addr.s_addr) { 2080 /* return the value user has set */ 2081 addr = imo->imo_multicast_addr; 2082 } else { 2083 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2084 addr.s_addr = (ia == NULL) ? INADDR_ANY 2085 : IA_SIN(ia)->sin_addr.s_addr; 2086 } 2087 error = sooptcopyout(sopt, &addr, sizeof addr); 2088 break; 2089 2090 case IP_MULTICAST_TTL: 2091 if (imo == NULL) 2092 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2093 else 2094 optval = coptval = imo->imo_multicast_ttl; 2095 if (sopt->sopt_valsize == 1) 2096 error = sooptcopyout(sopt, &coptval, 1); 2097 else 2098 error = sooptcopyout(sopt, &optval, sizeof optval); 2099 break; 2100 2101 case IP_MULTICAST_LOOP: 2102 if (imo == NULL) 2103 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2104 else 2105 optval = coptval = imo->imo_multicast_loop; 2106 if (sopt->sopt_valsize == 1) 2107 error = sooptcopyout(sopt, &coptval, 1); 2108 else 2109 error = sooptcopyout(sopt, &optval, sizeof optval); 2110 break; 2111 2112 default: 2113 error = ENOPROTOOPT; 2114 break; 2115 } 2116 return (error); 2117 } 2118 2119 /* 2120 * Discard the IP multicast options. 2121 */ 2122 void 2123 ip_freemoptions(struct ip_moptions *imo) 2124 { 2125 int i; 2126 2127 if (imo != NULL) { 2128 for (i = 0; i < imo->imo_num_memberships; ++i) 2129 in_delmulti(imo->imo_membership[i]); 2130 free(imo, M_IPMOPTS); 2131 } 2132 } 2133 2134 /* 2135 * Routine called from ip_output() to loop back a copy of an IP multicast 2136 * packet to the input queue of a specified interface. Note that this 2137 * calls the output routine of the loopback "driver", but with an interface 2138 * pointer that might NOT be a loopback interface -- evil, but easier than 2139 * replicating that code here. 2140 */ 2141 static void 2142 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2143 int hlen) 2144 { 2145 struct ip *ip; 2146 struct mbuf *copym; 2147 2148 copym = m_copypacket(m, MB_DONTWAIT); 2149 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2150 copym = m_pullup(copym, hlen); 2151 if (copym != NULL) { 2152 /* 2153 * if the checksum hasn't been computed, mark it as valid 2154 */ 2155 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2156 in_delayed_cksum(copym); 2157 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2158 copym->m_pkthdr.csum_flags |= 2159 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2160 copym->m_pkthdr.csum_data = 0xffff; 2161 } 2162 /* 2163 * We don't bother to fragment if the IP length is greater 2164 * than the interface's MTU. Can this possibly matter? 2165 */ 2166 ip = mtod(copym, struct ip *); 2167 ip->ip_len = htons(ip->ip_len); 2168 ip->ip_off = htons(ip->ip_off); 2169 ip->ip_sum = 0; 2170 if (ip->ip_vhl == IP_VHL_BORING) { 2171 ip->ip_sum = in_cksum_hdr(ip); 2172 } else { 2173 ip->ip_sum = in_cksum(copym, hlen); 2174 } 2175 /* 2176 * NB: 2177 * It's not clear whether there are any lingering 2178 * reentrancy problems in other areas which might 2179 * be exposed by using ip_input directly (in 2180 * particular, everything which modifies the packet 2181 * in-place). Yet another option is using the 2182 * protosw directly to deliver the looped back 2183 * packet. For the moment, we'll err on the side 2184 * of safety by using if_simloop(). 2185 */ 2186 #if 1 /* XXX */ 2187 if (dst->sin_family != AF_INET) { 2188 printf("ip_mloopback: bad address family %d\n", 2189 dst->sin_family); 2190 dst->sin_family = AF_INET; 2191 } 2192 #endif 2193 2194 #ifdef notdef 2195 copym->m_pkthdr.rcvif = ifp; 2196 ip_input(copym); 2197 #else 2198 if_simloop(ifp, copym, dst->sin_family, 0); 2199 #endif 2200 } 2201 } 2202