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 1.22 2004/10/15 22:59:10 hsu Exp $ 32 */ 33 34 #define _IP_VHL 35 36 #include "opt_ipfw.h" 37 #include "opt_ipdn.h" 38 #include "opt_ipdivert.h" 39 #include "opt_ipfilter.h" 40 #include "opt_ipsec.h" 41 #include "opt_random_ip_id.h" 42 #include "opt_mbuf_stress_test.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/sysctl.h> 54 #include <sys/in_cksum.h> 55 56 #include <net/if.h> 57 #include <net/netisr.h> 58 #include <net/pfil.h> 59 #include <net/route.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/ip.h> 64 #include <netinet/in_pcb.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip_var.h> 67 68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 69 70 #ifdef IPSEC 71 #include <netinet6/ipsec.h> 72 #include <netproto/key/key.h> 73 #ifdef IPSEC_DEBUG 74 #include <netproto/key/key_debug.h> 75 #else 76 #define KEYDEBUG(lev,arg) 77 #endif 78 #endif /*IPSEC*/ 79 80 #ifdef FAST_IPSEC 81 #include <netproto/ipsec/ipsec.h> 82 #include <netproto/ipsec/xform.h> 83 #include <netproto/ipsec/key.h> 84 #endif /*FAST_IPSEC*/ 85 86 #include <net/ipfw/ip_fw.h> 87 #include <net/dummynet/ip_dummynet.h> 88 89 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 90 x, (ntohl(a.s_addr)>>24)&0xFF,\ 91 (ntohl(a.s_addr)>>16)&0xFF,\ 92 (ntohl(a.s_addr)>>8)&0xFF,\ 93 (ntohl(a.s_addr))&0xFF, y); 94 95 u_short ip_id; 96 97 #ifdef MBUF_STRESS_TEST 98 int mbuf_frag_size = 0; 99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 101 #endif 102 103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 104 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 105 static void ip_mloopback 106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 107 static int ip_getmoptions 108 (struct sockopt *, struct ip_moptions *); 109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 110 static int ip_setmoptions 111 (struct sockopt *, struct ip_moptions **); 112 113 int ip_optcopy(struct ip *, struct ip *); 114 115 116 extern struct protosw inetsw[]; 117 118 /* 119 * IP output. The packet in mbuf chain m contains a skeletal IP 120 * header (with len, off, ttl, proto, tos, src, dst). 121 * The mbuf chain containing the packet will be freed. 122 * The mbuf opt, if present, will not be freed. 123 */ 124 int 125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 126 int flags, struct ip_moptions *imo, struct inpcb *inp) 127 { 128 struct ip *ip; 129 struct ifnet *ifp = NULL; /* keep compiler happy */ 130 struct mbuf *m; 131 int hlen = sizeof (struct ip); 132 int len, off, error = 0; 133 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 134 struct in_ifaddr *ia = NULL; 135 int isbroadcast, sw_csum; 136 struct in_addr pkt_dst; 137 struct route iproute; 138 #ifdef IPSEC 139 struct secpolicy *sp = NULL; 140 struct socket *so = inp ? inp->inp_socket : NULL; 141 #endif 142 #ifdef FAST_IPSEC 143 struct m_tag *mtag; 144 struct secpolicy *sp = NULL; 145 struct tdb_ident *tdbi; 146 int s; 147 #endif /* FAST_IPSEC */ 148 struct ip_fw_args args; 149 int src_was_INADDR_ANY = 0; /* as the name says... */ 150 151 args.eh = NULL; 152 args.rule = NULL; 153 args.next_hop = NULL; 154 args.divert_rule = 0; /* divert cookie */ 155 156 /* Grab info from MT_TAG mbufs prepended to the chain. */ 157 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) { 158 switch(m0->_m_tag_id) { 159 default: 160 printf("ip_output: unrecognised MT_TAG tag %d\n", 161 m0->_m_tag_id); 162 break; 163 164 case PACKET_TAG_DUMMYNET: 165 /* 166 * the packet was already tagged, so part of the 167 * processing was already done, and we need to go down. 168 * Get parameters from the header. 169 */ 170 args.rule = ((struct dn_pkt *)m0)->rule; 171 opt = NULL ; 172 ro = & ( ((struct dn_pkt *)m0)->ro ) ; 173 imo = NULL ; 174 dst = ((struct dn_pkt *)m0)->dn_dst ; 175 ifp = ((struct dn_pkt *)m0)->ifp ; 176 flags = ((struct dn_pkt *)m0)->flags ; 177 break; 178 179 case PACKET_TAG_DIVERT: 180 args.divert_rule = (int)m0->m_data & 0xffff; 181 break; 182 183 case PACKET_TAG_IPFORWARD: 184 args.next_hop = (struct sockaddr_in *)m0->m_data; 185 break; 186 } 187 } 188 m = m0; 189 190 KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR")); 191 192 if (ro == NULL) { 193 ro = &iproute; 194 bzero(ro, sizeof(*ro)); 195 } 196 197 if (args.rule != NULL) { /* dummynet already saw us */ 198 ip = mtod(m, struct ip *); 199 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 200 if (ro->ro_rt) 201 ia = ifatoia(ro->ro_rt->rt_ifa); 202 goto sendit; 203 } 204 205 if (opt) { 206 len = 0; 207 m = ip_insertoptions(m, opt, &len); 208 if (len != 0) 209 hlen = len; 210 } 211 ip = mtod(m, struct ip *); 212 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 213 214 /* 215 * Fill in IP header. 216 */ 217 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 218 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 219 ip->ip_off &= IP_DF; 220 #ifdef RANDOM_IP_ID 221 ip->ip_id = ip_randomid(); 222 #else 223 ip->ip_id = htons(ip_id++); 224 #endif 225 ipstat.ips_localout++; 226 } else { 227 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 228 } 229 230 dst = (struct sockaddr_in *)&ro->ro_dst; 231 /* 232 * If there is a cached route, 233 * check that it is to the same destination 234 * and is still up. If not, free it and try again. 235 * The address family should also be checked in case of sharing the 236 * cache with IPv6. 237 */ 238 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 239 dst->sin_family != AF_INET || 240 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 241 RTFREE(ro->ro_rt); 242 ro->ro_rt = (struct rtentry *)0; 243 } 244 if (ro->ro_rt == 0) { 245 bzero(dst, sizeof(*dst)); 246 dst->sin_family = AF_INET; 247 dst->sin_len = sizeof(*dst); 248 dst->sin_addr = pkt_dst; 249 } 250 /* 251 * If routing to interface only, 252 * short circuit routing lookup. 253 */ 254 if (flags & IP_ROUTETOIF) { 255 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 256 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 257 ipstat.ips_noroute++; 258 error = ENETUNREACH; 259 goto bad; 260 } 261 ifp = ia->ia_ifp; 262 ip->ip_ttl = 1; 263 isbroadcast = in_broadcast(dst->sin_addr, ifp); 264 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 265 imo != NULL && imo->imo_multicast_ifp != NULL) { 266 /* 267 * Bypass the normal routing lookup for multicast 268 * packets if the interface is specified. 269 */ 270 ifp = imo->imo_multicast_ifp; 271 IFP_TO_IA(ifp, ia); 272 isbroadcast = 0; /* fool gcc */ 273 } else { 274 /* 275 * If this is the case, we probably don't want to allocate 276 * a protocol-cloned route since we didn't get one from the 277 * ULP. This lets TCP do its thing, while not burdening 278 * forwarding or ICMP with the overhead of cloning a route. 279 * Of course, we still want to do any cloning requested by 280 * the link layer, as this is probably required in all cases 281 * for correct operation (as it is for ARP). 282 */ 283 if (ro->ro_rt == 0) 284 rtalloc_ign(ro, RTF_PRCLONING); 285 if (ro->ro_rt == 0) { 286 ipstat.ips_noroute++; 287 error = EHOSTUNREACH; 288 goto bad; 289 } 290 ia = ifatoia(ro->ro_rt->rt_ifa); 291 ifp = ro->ro_rt->rt_ifp; 292 ro->ro_rt->rt_use++; 293 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 294 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 295 if (ro->ro_rt->rt_flags & RTF_HOST) 296 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 297 else 298 isbroadcast = in_broadcast(dst->sin_addr, ifp); 299 } 300 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 301 struct in_multi *inm; 302 303 m->m_flags |= M_MCAST; 304 /* 305 * IP destination address is multicast. Make sure "dst" 306 * still points to the address in "ro". (It may have been 307 * changed to point to a gateway address, above.) 308 */ 309 dst = (struct sockaddr_in *)&ro->ro_dst; 310 /* 311 * See if the caller provided any multicast options 312 */ 313 if (imo != NULL) { 314 ip->ip_ttl = imo->imo_multicast_ttl; 315 if (imo->imo_multicast_vif != -1) 316 ip->ip_src.s_addr = 317 ip_mcast_src ? 318 ip_mcast_src(imo->imo_multicast_vif) : 319 INADDR_ANY; 320 } else 321 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 322 /* 323 * Confirm that the outgoing interface supports multicast. 324 */ 325 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 326 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 327 ipstat.ips_noroute++; 328 error = ENETUNREACH; 329 goto bad; 330 } 331 } 332 /* 333 * If source address not specified yet, use address 334 * of outgoing interface. 335 */ 336 if (ip->ip_src.s_addr == INADDR_ANY) { 337 /* Interface may have no addresses. */ 338 if (ia != NULL) 339 ip->ip_src = IA_SIN(ia)->sin_addr; 340 } 341 342 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 343 if (inm != NULL && 344 (imo == NULL || imo->imo_multicast_loop)) { 345 /* 346 * If we belong to the destination multicast group 347 * on the outgoing interface, and the caller did not 348 * forbid loopback, loop back a copy. 349 */ 350 ip_mloopback(ifp, m, dst, hlen); 351 } 352 else { 353 /* 354 * If we are acting as a multicast router, perform 355 * multicast forwarding as if the packet had just 356 * arrived on the interface to which we are about 357 * to send. The multicast forwarding function 358 * recursively calls this function, using the 359 * IP_FORWARDING flag to prevent infinite recursion. 360 * 361 * Multicasts that are looped back by ip_mloopback(), 362 * above, will be forwarded by the ip_input() routine, 363 * if necessary. 364 */ 365 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 366 /* 367 * If rsvp daemon is not running, do not 368 * set ip_moptions. This ensures that the packet 369 * is multicast and not just sent down one link 370 * as prescribed by rsvpd. 371 */ 372 if (!rsvp_on) 373 imo = NULL; 374 if (ip_mforward && 375 ip_mforward(ip, ifp, m, imo) != 0) { 376 m_freem(m); 377 goto done; 378 } 379 } 380 } 381 382 /* 383 * Multicasts with a time-to-live of zero may be looped- 384 * back, above, but must not be transmitted on a network. 385 * Also, multicasts addressed to the loopback interface 386 * are not sent -- the above call to ip_mloopback() will 387 * loop back a copy if this host actually belongs to the 388 * destination group on the loopback interface. 389 */ 390 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 391 m_freem(m); 392 goto done; 393 } 394 395 goto sendit; 396 } 397 #ifndef notdef 398 /* 399 * If the source address is not specified yet, use the address 400 * of the outoing interface. In case, keep note we did that, so 401 * if the the firewall changes the next-hop causing the output 402 * interface to change, we can fix that. 403 */ 404 if (ip->ip_src.s_addr == INADDR_ANY) { 405 /* Interface may have no addresses. */ 406 if (ia != NULL) { 407 ip->ip_src = IA_SIN(ia)->sin_addr; 408 src_was_INADDR_ANY = 1; 409 } 410 } 411 #endif /* notdef */ 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 } 422 423 /* 424 * Look for broadcast address and 425 * verify user is allowed to send 426 * such a packet. 427 */ 428 if (isbroadcast) { 429 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 430 error = EADDRNOTAVAIL; 431 goto bad; 432 } 433 if ((flags & IP_ALLOWBROADCAST) == 0) { 434 error = EACCES; 435 goto bad; 436 } 437 /* don't allow broadcast messages to be fragmented */ 438 if (ip->ip_len > ifp->if_mtu) { 439 error = EMSGSIZE; 440 goto bad; 441 } 442 m->m_flags |= M_BCAST; 443 } else { 444 m->m_flags &= ~M_BCAST; 445 } 446 447 sendit: 448 #ifdef IPSEC 449 /* get SP for this packet */ 450 if (so == NULL) 451 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 452 else 453 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 454 455 if (sp == NULL) { 456 ipsecstat.out_inval++; 457 goto bad; 458 } 459 460 error = 0; 461 462 /* check policy */ 463 switch (sp->policy) { 464 case IPSEC_POLICY_DISCARD: 465 /* 466 * This packet is just discarded. 467 */ 468 ipsecstat.out_polvio++; 469 goto bad; 470 471 case IPSEC_POLICY_BYPASS: 472 case IPSEC_POLICY_NONE: 473 /* no need to do IPsec. */ 474 goto skip_ipsec; 475 476 case IPSEC_POLICY_IPSEC: 477 if (sp->req == NULL) { 478 /* acquire a policy */ 479 error = key_spdacquire(sp); 480 goto bad; 481 } 482 break; 483 484 case IPSEC_POLICY_ENTRUST: 485 default: 486 printf("ip_output: Invalid policy found. %d\n", sp->policy); 487 } 488 { 489 struct ipsec_output_state state; 490 bzero(&state, sizeof(state)); 491 state.m = m; 492 if (flags & IP_ROUTETOIF) { 493 state.ro = &iproute; 494 bzero(&iproute, sizeof(iproute)); 495 } else 496 state.ro = ro; 497 state.dst = (struct sockaddr *)dst; 498 499 ip->ip_sum = 0; 500 501 /* 502 * XXX 503 * delayed checksums are not currently compatible with IPsec 504 */ 505 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 506 in_delayed_cksum(m); 507 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 508 } 509 510 ip->ip_len = htons(ip->ip_len); 511 ip->ip_off = htons(ip->ip_off); 512 513 error = ipsec4_output(&state, sp, flags); 514 515 m = state.m; 516 if (flags & IP_ROUTETOIF) { 517 /* 518 * if we have tunnel mode SA, we may need to ignore 519 * IP_ROUTETOIF. 520 */ 521 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 522 flags &= ~IP_ROUTETOIF; 523 ro = state.ro; 524 } 525 } else 526 ro = state.ro; 527 dst = (struct sockaddr_in *)state.dst; 528 if (error) { 529 /* mbuf is already reclaimed in ipsec4_output. */ 530 m0 = NULL; 531 switch (error) { 532 case EHOSTUNREACH: 533 case ENETUNREACH: 534 case EMSGSIZE: 535 case ENOBUFS: 536 case ENOMEM: 537 break; 538 default: 539 printf("ip4_output (ipsec): error code %d\n", error); 540 /*fall through*/ 541 case ENOENT: 542 /* don't show these error codes to the user */ 543 error = 0; 544 break; 545 } 546 goto bad; 547 } 548 } 549 550 /* be sure to update variables that are affected by ipsec4_output() */ 551 ip = mtod(m, struct ip *); 552 #ifdef _IP_VHL 553 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 554 #else 555 hlen = ip->ip_hl << 2; 556 #endif 557 if (ro->ro_rt == NULL) { 558 if ((flags & IP_ROUTETOIF) == 0) { 559 printf("ip_output: " 560 "can't update route after IPsec processing\n"); 561 error = EHOSTUNREACH; /*XXX*/ 562 goto bad; 563 } 564 } else { 565 ia = ifatoia(ro->ro_rt->rt_ifa); 566 ifp = ro->ro_rt->rt_ifp; 567 } 568 569 /* make it flipped, again. */ 570 ip->ip_len = ntohs(ip->ip_len); 571 ip->ip_off = ntohs(ip->ip_off); 572 skip_ipsec: 573 #endif /*IPSEC*/ 574 #ifdef FAST_IPSEC 575 /* 576 * Check the security policy (SP) for the packet and, if 577 * required, do IPsec-related processing. There are two 578 * cases here; the first time a packet is sent through 579 * it will be untagged and handled by ipsec4_checkpolicy. 580 * If the packet is resubmitted to ip_output (e.g. after 581 * AH, ESP, etc. processing), there will be a tag to bypass 582 * the lookup and related policy checking. 583 */ 584 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 585 s = splnet(); 586 if (mtag != NULL) { 587 tdbi = (struct tdb_ident *)(mtag + 1); 588 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 589 if (sp == NULL) 590 error = -EINVAL; /* force silent drop */ 591 m_tag_delete(m, mtag); 592 } else { 593 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 594 &error, inp); 595 } 596 /* 597 * There are four return cases: 598 * sp != NULL apply IPsec policy 599 * sp == NULL, error == 0 no IPsec handling needed 600 * sp == NULL, error == -EINVAL discard packet w/o error 601 * sp == NULL, error != 0 discard packet, report error 602 */ 603 if (sp != NULL) { 604 /* Loop detection, check if ipsec processing already done */ 605 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 606 for (mtag = m_tag_first(m); mtag != NULL; 607 mtag = m_tag_next(m, mtag)) { 608 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 609 continue; 610 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 611 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 612 continue; 613 /* 614 * Check if policy has an SA associated with it. 615 * This can happen when an SP has yet to acquire 616 * an SA; e.g. on first reference. If it occurs, 617 * then we let ipsec4_process_packet do its thing. 618 */ 619 if (sp->req->sav == NULL) 620 break; 621 tdbi = (struct tdb_ident *)(mtag + 1); 622 if (tdbi->spi == sp->req->sav->spi && 623 tdbi->proto == sp->req->sav->sah->saidx.proto && 624 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 625 sizeof (union sockaddr_union)) == 0) { 626 /* 627 * No IPsec processing is needed, free 628 * reference to SP. 629 * 630 * NB: null pointer to avoid free at 631 * done: below. 632 */ 633 KEY_FREESP(&sp), sp = NULL; 634 splx(s); 635 goto spd_done; 636 } 637 } 638 639 /* 640 * Do delayed checksums now because we send before 641 * this is done in the normal processing path. 642 */ 643 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 644 in_delayed_cksum(m); 645 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 646 } 647 648 ip->ip_len = htons(ip->ip_len); 649 ip->ip_off = htons(ip->ip_off); 650 651 /* NB: callee frees mbuf */ 652 error = ipsec4_process_packet(m, sp->req, flags, 0); 653 /* 654 * Preserve KAME behaviour: ENOENT can be returned 655 * when an SA acquire is in progress. Don't propagate 656 * this to user-level; it confuses applications. 657 * 658 * XXX this will go away when the SADB is redone. 659 */ 660 if (error == ENOENT) 661 error = 0; 662 splx(s); 663 goto done; 664 } else { 665 splx(s); 666 667 if (error != 0) { 668 /* 669 * Hack: -EINVAL is used to signal that a packet 670 * should be silently discarded. This is typically 671 * because we asked key management for an SA and 672 * it was delayed (e.g. kicked up to IKE). 673 */ 674 if (error == -EINVAL) 675 error = 0; 676 goto bad; 677 } else { 678 /* No IPsec processing for this packet. */ 679 } 680 #ifdef notyet 681 /* 682 * If deferred crypto processing is needed, check that 683 * the interface supports it. 684 */ 685 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 686 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 687 /* notify IPsec to do its own crypto */ 688 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 689 error = EHOSTUNREACH; 690 goto bad; 691 } 692 #endif 693 } 694 spd_done: 695 #endif /* FAST_IPSEC */ 696 /* 697 * IpHack's section. 698 * - Xlate: translate packet's addr/port (NAT). 699 * - Firewall: deny/allow/etc. 700 * - Wrap: fake packet's addr/port <unimpl.> 701 * - Encapsulate: put it in another IP and send out. <unimp.> 702 */ 703 704 /* 705 * Run through list of hooks for output packets. 706 */ 707 if (pfil_has_hooks(&inet_pfil_hook)) { 708 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 709 if (error != 0 || m == NULL) 710 goto done; 711 ip = mtod(m, struct ip *); 712 } 713 714 /* 715 * Check with the firewall... 716 * but not if we are already being fwd'd from a firewall. 717 */ 718 if (fw_enable && IPFW_LOADED && !args.next_hop) { 719 struct sockaddr_in *old = dst; 720 721 args.m = m; 722 args.next_hop = dst; 723 args.oif = ifp; 724 off = ip_fw_chk_ptr(&args); 725 m = args.m; 726 dst = args.next_hop; 727 728 /* 729 * On return we must do the following: 730 * m == NULL -> drop the pkt (old interface, deprecated) 731 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 732 * 1<=off<= 0xffff -> DIVERT 733 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 734 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 735 * dst != old -> IPFIREWALL_FORWARD 736 * off==0, dst==old -> accept 737 * If some of the above modules are not compiled in, then 738 * we should't have to check the corresponding condition 739 * (because the ipfw control socket should not accept 740 * unsupported rules), but better play safe and drop 741 * packets in case of doubt. 742 */ 743 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 744 if (m) 745 m_freem(m); 746 error = EACCES; 747 goto done; 748 } 749 ip = mtod(m, struct ip *); 750 if (off == 0 && dst == old) /* common case */ 751 goto pass; 752 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { 753 /* 754 * pass the pkt to dummynet. Need to include 755 * pipe number, m, ifp, ro, dst because these are 756 * not recomputed in the next pass. 757 * All other parameters have been already used and 758 * so they are not needed anymore. 759 * XXX note: if the ifp or ro entry are deleted 760 * while a pkt is in dummynet, we are in trouble! 761 */ 762 args.ro = ro; 763 args.dst = dst; 764 args.flags = flags; 765 766 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 767 &args); 768 goto done; 769 } 770 #ifdef IPDIVERT 771 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { 772 struct mbuf *clone = NULL; 773 774 /* Clone packet if we're doing a 'tee' */ 775 if ((off & IP_FW_PORT_TEE_FLAG) != 0) 776 clone = m_dup(m, MB_DONTWAIT); 777 778 /* 779 * XXX 780 * delayed checksums are not currently compatible 781 * with divert sockets. 782 */ 783 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 784 in_delayed_cksum(m); 785 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 786 } 787 788 /* Restore packet header fields to original values */ 789 ip->ip_len = htons(ip->ip_len); 790 ip->ip_off = htons(ip->ip_off); 791 792 /* Deliver packet to divert input routine */ 793 divert_packet(m, 0, off & 0xffff, args.divert_rule); 794 795 /* If 'tee', continue with original packet */ 796 if (clone != NULL) { 797 m = clone; 798 ip = mtod(m, struct ip *); 799 goto pass; 800 } 801 goto done; 802 } 803 #endif 804 805 /* IPFIREWALL_FORWARD */ 806 /* 807 * Check dst to make sure it is directly reachable on the 808 * interface we previously thought it was. 809 * If it isn't (which may be likely in some situations) we have 810 * to re-route it (ie, find a route for the next-hop and the 811 * associated interface) and set them here. This is nested 812 * forwarding which in most cases is undesirable, except where 813 * such control is nigh impossible. So we do it here. 814 * And I'm babbling. 815 */ 816 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 817 #if 0 818 /* 819 * XXX To improve readability, this block should be 820 * changed into a function call as below: 821 */ 822 error = ip_ipforward(&m, &dst, &ifp); 823 if (error) 824 goto bad; 825 if (m == NULL) /* ip_input consumed the mbuf */ 826 goto done; 827 #else 828 struct in_ifaddr *ia; 829 830 /* 831 * XXX sro_fwd below is static, and a pointer 832 * to it gets passed to routines downstream. 833 * This could have surprisingly bad results in 834 * practice, because its content is overwritten 835 * by subsequent packets. 836 */ 837 /* There must be a better way to do this next line... */ 838 static struct route sro_fwd; 839 struct route *ro_fwd = &sro_fwd; 840 841 #if 0 842 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 843 dst->sin_addr, "\n"); 844 #endif 845 846 /* 847 * We need to figure out if we have been forwarded 848 * to a local socket. If so, then we should somehow 849 * "loop back" to ip_input, and get directed to the 850 * PCB as if we had received this packet. This is 851 * because it may be dificult to identify the packets 852 * you want to forward until they are being output 853 * and have selected an interface. (e.g. locally 854 * initiated packets) If we used the loopback inteface, 855 * we would not be able to control what happens 856 * as the packet runs through ip_input() as 857 * it is done through a ISR. 858 */ 859 LIST_FOREACH(ia, 860 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 861 /* 862 * If the addr to forward to is one 863 * of ours, we pretend to 864 * be the destination for this packet. 865 */ 866 if (IA_SIN(ia)->sin_addr.s_addr == 867 dst->sin_addr.s_addr) 868 break; 869 } 870 if (ia) { /* tell ip_input "dont filter" */ 871 struct m_hdr tag; 872 873 tag.mh_type = MT_TAG; 874 tag.mh_flags = PACKET_TAG_IPFORWARD; 875 tag.mh_data = (caddr_t)args.next_hop; 876 tag.mh_next = m; 877 878 if (m->m_pkthdr.rcvif == NULL) 879 m->m_pkthdr.rcvif = ifunit("lo0"); 880 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 881 m->m_pkthdr.csum_flags |= 882 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 883 m0->m_pkthdr.csum_data = 0xffff; 884 } 885 m->m_pkthdr.csum_flags |= 886 CSUM_IP_CHECKED | CSUM_IP_VALID; 887 ip->ip_len = htons(ip->ip_len); 888 ip->ip_off = htons(ip->ip_off); 889 ip_input((struct mbuf *)&tag); 890 goto done; 891 } 892 /* Some of the logic for this was 893 * nicked from above. 894 * 895 * This rewrites the cached route in a local PCB. 896 * Is this what we want to do? 897 */ 898 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 899 900 ro_fwd->ro_rt = 0; 901 rtalloc_ign(ro_fwd, RTF_PRCLONING); 902 903 if (ro_fwd->ro_rt == 0) { 904 ipstat.ips_noroute++; 905 error = EHOSTUNREACH; 906 goto bad; 907 } 908 909 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 910 ifp = ro_fwd->ro_rt->rt_ifp; 911 ro_fwd->ro_rt->rt_use++; 912 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 913 dst = (struct sockaddr_in *) 914 ro_fwd->ro_rt->rt_gateway; 915 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 916 isbroadcast = 917 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 918 else 919 isbroadcast = in_broadcast(dst->sin_addr, ifp); 920 if (ro->ro_rt) 921 RTFREE(ro->ro_rt); 922 ro->ro_rt = ro_fwd->ro_rt; 923 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 924 925 #endif /* ... block to be put into a function */ 926 /* 927 * If we added a default src ip earlier, 928 * which would have been gotten from the-then 929 * interface, do it again, from the new one. 930 */ 931 if (src_was_INADDR_ANY) 932 ip->ip_src = IA_SIN(ia)->sin_addr; 933 goto pass ; 934 } 935 936 /* 937 * if we get here, none of the above matches, and 938 * we have to drop the pkt 939 */ 940 m_freem(m); 941 error = EACCES; /* not sure this is the right error msg */ 942 goto done; 943 } 944 945 pass: 946 /* 127/8 must not appear on wire - RFC1122. */ 947 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 948 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 949 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 950 ipstat.ips_badaddr++; 951 error = EADDRNOTAVAIL; 952 goto bad; 953 } 954 } 955 956 m->m_pkthdr.csum_flags |= CSUM_IP; 957 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 958 if (sw_csum & CSUM_DELAY_DATA) { 959 in_delayed_cksum(m); 960 sw_csum &= ~CSUM_DELAY_DATA; 961 } 962 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 963 964 /* 965 * If small enough for interface, or the interface will take 966 * care of the fragmentation for us, can just send directly. 967 */ 968 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 969 (ip->ip_off & IP_DF) == 0)) { 970 ip->ip_len = htons(ip->ip_len); 971 ip->ip_off = htons(ip->ip_off); 972 ip->ip_sum = 0; 973 if (sw_csum & CSUM_DELAY_IP) { 974 if (ip->ip_vhl == IP_VHL_BORING) { 975 ip->ip_sum = in_cksum_hdr(ip); 976 } else { 977 ip->ip_sum = in_cksum(m, hlen); 978 } 979 } 980 981 /* Record statistics for this interface address. */ 982 if (!(flags & IP_FORWARDING) && ia) { 983 ia->ia_ifa.if_opackets++; 984 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 985 } 986 987 #ifdef IPSEC 988 /* clean ipsec history once it goes out of the node */ 989 ipsec_delaux(m); 990 #endif 991 992 #ifdef MBUF_STRESS_TEST 993 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 994 struct mbuf *m1, *m2; 995 int length, tmp; 996 997 tmp = length = m->m_pkthdr.len; 998 999 while ((length -= mbuf_frag_size) >= 1) { 1000 m1 = m_split(m, length, MB_DONTWAIT); 1001 if (m1 == NULL) 1002 break; 1003 m1->m_flags &= ~M_PKTHDR; 1004 m2 = m; 1005 while (m2->m_next != NULL) 1006 m2 = m2->m_next; 1007 m2->m_next = m1; 1008 } 1009 m->m_pkthdr.len = tmp; 1010 } 1011 #endif 1012 error = (*ifp->if_output)(ifp, m, 1013 (struct sockaddr *)dst, ro->ro_rt); 1014 goto done; 1015 } 1016 1017 if (ip->ip_off & IP_DF) { 1018 error = EMSGSIZE; 1019 /* 1020 * This case can happen if the user changed the MTU 1021 * of an interface after enabling IP on it. Because 1022 * most netifs don't keep track of routes pointing to 1023 * them, there is no way for one to update all its 1024 * routes when the MTU is changed. 1025 */ 1026 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1027 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1028 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1029 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1030 } 1031 ipstat.ips_cantfrag++; 1032 goto bad; 1033 } 1034 1035 /* 1036 * Too large for interface; fragment if possible. If successful, 1037 * on return, m will point to a list of packets to be sent. 1038 */ 1039 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1040 if (error) 1041 goto bad; 1042 for (; m; m = m0) { 1043 m0 = m->m_nextpkt; 1044 m->m_nextpkt = 0; 1045 #ifdef IPSEC 1046 /* clean ipsec history once it goes out of the node */ 1047 ipsec_delaux(m); 1048 #endif 1049 if (error == 0) { 1050 /* Record statistics for this interface address. */ 1051 if (ia != NULL) { 1052 ia->ia_ifa.if_opackets++; 1053 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1054 } 1055 1056 error = (*ifp->if_output)(ifp, m, 1057 (struct sockaddr *)dst, ro->ro_rt); 1058 } else 1059 m_freem(m); 1060 } 1061 1062 if (error == 0) 1063 ipstat.ips_fragmented++; 1064 1065 done: 1066 if (ro == &iproute && ro->ro_rt) { 1067 RTFREE(ro->ro_rt); 1068 ro->ro_rt = NULL; 1069 } 1070 #ifdef IPSEC 1071 if (sp != NULL) { 1072 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1073 printf("DP ip_output call free SP:%p\n", sp)); 1074 key_freesp(sp); 1075 } 1076 #endif 1077 #ifdef FAST_IPSEC 1078 if (sp != NULL) 1079 KEY_FREESP(&sp); 1080 #endif 1081 return (error); 1082 bad: 1083 m_freem(m); 1084 goto done; 1085 } 1086 1087 /* 1088 * Create a chain of fragments which fit the given mtu. m_frag points to the 1089 * mbuf to be fragmented; on return it points to the chain with the fragments. 1090 * Return 0 if no error. If error, m_frag may contain a partially built 1091 * chain of fragments that should be freed by the caller. 1092 * 1093 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1094 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1095 */ 1096 int 1097 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1098 u_long if_hwassist_flags, int sw_csum) 1099 { 1100 int error = 0; 1101 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1102 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1103 int off; 1104 struct mbuf *m0 = *m_frag; /* the original packet */ 1105 int firstlen; 1106 struct mbuf **mnext; 1107 int nfrags; 1108 1109 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1110 ipstat.ips_cantfrag++; 1111 return EMSGSIZE; 1112 } 1113 1114 /* 1115 * Must be able to put at least 8 bytes per fragment. 1116 */ 1117 if (len < 8) 1118 return EMSGSIZE; 1119 1120 /* 1121 * If the interface will not calculate checksums on 1122 * fragmented packets, then do it here. 1123 */ 1124 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && 1125 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { 1126 in_delayed_cksum(m0); 1127 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1128 } 1129 1130 if (len > PAGE_SIZE) { 1131 /* 1132 * Fragment large datagrams such that each segment 1133 * contains a multiple of PAGE_SIZE amount of data, 1134 * plus headers. This enables a receiver to perform 1135 * page-flipping zero-copy optimizations. 1136 * 1137 * XXX When does this help given that sender and receiver 1138 * could have different page sizes, and also mtu could 1139 * be less than the receiver's page size ? 1140 */ 1141 int newlen; 1142 struct mbuf *m; 1143 1144 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1145 off += m->m_len; 1146 1147 /* 1148 * firstlen (off - hlen) must be aligned on an 1149 * 8-byte boundary 1150 */ 1151 if (off < hlen) 1152 goto smart_frag_failure; 1153 off = ((off - hlen) & ~7) + hlen; 1154 newlen = (~PAGE_MASK) & mtu; 1155 if ((newlen + sizeof (struct ip)) > mtu) { 1156 /* we failed, go back the default */ 1157 smart_frag_failure: 1158 newlen = len; 1159 off = hlen + len; 1160 } 1161 len = newlen; 1162 1163 } else { 1164 off = hlen + len; 1165 } 1166 1167 firstlen = off - hlen; 1168 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1169 1170 /* 1171 * Loop through length of segment after first fragment, 1172 * make new header and copy data of each part and link onto chain. 1173 * Here, m0 is the original packet, m is the fragment being created. 1174 * The fragments are linked off the m_nextpkt of the original 1175 * packet, which after processing serves as the first fragment. 1176 */ 1177 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1178 struct ip *mhip; /* ip header on the fragment */ 1179 struct mbuf *m; 1180 int mhlen = sizeof (struct ip); 1181 1182 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1183 if (m == 0) { 1184 error = ENOBUFS; 1185 ipstat.ips_odropped++; 1186 goto done; 1187 } 1188 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1189 /* 1190 * In the first mbuf, leave room for the link header, then 1191 * copy the original IP header including options. The payload 1192 * goes into an additional mbuf chain returned by m_copy(). 1193 */ 1194 m->m_data += max_linkhdr; 1195 mhip = mtod(m, struct ip *); 1196 *mhip = *ip; 1197 if (hlen > sizeof (struct ip)) { 1198 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1199 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1200 } 1201 m->m_len = mhlen; 1202 /* XXX do we need to add ip->ip_off below ? */ 1203 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1204 if (off + len >= ip->ip_len) { /* last fragment */ 1205 len = ip->ip_len - off; 1206 m->m_flags |= M_LASTFRAG; 1207 } else 1208 mhip->ip_off |= IP_MF; 1209 mhip->ip_len = htons((u_short)(len + mhlen)); 1210 m->m_next = m_copy(m0, off, len); 1211 if (m->m_next == 0) { /* copy failed */ 1212 m_free(m); 1213 error = ENOBUFS; /* ??? */ 1214 ipstat.ips_odropped++; 1215 goto done; 1216 } 1217 m->m_pkthdr.len = mhlen + len; 1218 m->m_pkthdr.rcvif = (struct ifnet *)0; 1219 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1220 mhip->ip_off = htons(mhip->ip_off); 1221 mhip->ip_sum = 0; 1222 if (sw_csum & CSUM_DELAY_IP) 1223 mhip->ip_sum = in_cksum(m, mhlen); 1224 *mnext = m; 1225 mnext = &m->m_nextpkt; 1226 } 1227 ipstat.ips_ofragments += nfrags; 1228 1229 /* set first marker for fragment chain */ 1230 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1231 m0->m_pkthdr.csum_data = nfrags; 1232 1233 /* 1234 * Update first fragment by trimming what's been copied out 1235 * and updating header. 1236 */ 1237 m_adj(m0, hlen + firstlen - ip->ip_len); 1238 m0->m_pkthdr.len = hlen + firstlen; 1239 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1240 ip->ip_off |= IP_MF; 1241 ip->ip_off = htons(ip->ip_off); 1242 ip->ip_sum = 0; 1243 if (sw_csum & CSUM_DELAY_IP) 1244 ip->ip_sum = in_cksum(m0, hlen); 1245 1246 done: 1247 *m_frag = m0; 1248 return error; 1249 } 1250 1251 void 1252 in_delayed_cksum(struct mbuf *m) 1253 { 1254 struct ip *ip; 1255 u_short csum, offset; 1256 1257 ip = mtod(m, struct ip *); 1258 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1259 csum = in_cksum_skip(m, ip->ip_len, offset); 1260 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1261 csum = 0xffff; 1262 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1263 1264 if (offset + sizeof(u_short) > m->m_len) { 1265 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1266 m->m_len, offset, ip->ip_p); 1267 /* 1268 * XXX 1269 * this shouldn't happen, but if it does, the 1270 * correct behavior may be to insert the checksum 1271 * in the existing chain instead of rearranging it. 1272 */ 1273 m = m_pullup(m, offset + sizeof(u_short)); 1274 } 1275 *(u_short *)(m->m_data + offset) = csum; 1276 } 1277 1278 /* 1279 * Insert IP options into preformed packet. 1280 * Adjust IP destination as required for IP source routing, 1281 * as indicated by a non-zero in_addr at the start of the options. 1282 * 1283 * XXX This routine assumes that the packet has no options in place. 1284 */ 1285 static struct mbuf * 1286 ip_insertoptions(m, opt, phlen) 1287 struct mbuf *m; 1288 struct mbuf *opt; 1289 int *phlen; 1290 { 1291 struct ipoption *p = mtod(opt, struct ipoption *); 1292 struct mbuf *n; 1293 struct ip *ip = mtod(m, struct ip *); 1294 unsigned optlen; 1295 1296 optlen = opt->m_len - sizeof(p->ipopt_dst); 1297 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1298 *phlen = 0; 1299 return (m); /* XXX should fail */ 1300 } 1301 if (p->ipopt_dst.s_addr) 1302 ip->ip_dst = p->ipopt_dst; 1303 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1304 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1305 if (n == 0) { 1306 *phlen = 0; 1307 return (m); 1308 } 1309 n->m_pkthdr.rcvif = (struct ifnet *)0; 1310 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1311 m->m_len -= sizeof(struct ip); 1312 m->m_data += sizeof(struct ip); 1313 n->m_next = m; 1314 m = n; 1315 m->m_len = optlen + sizeof(struct ip); 1316 m->m_data += max_linkhdr; 1317 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1318 } else { 1319 m->m_data -= optlen; 1320 m->m_len += optlen; 1321 m->m_pkthdr.len += optlen; 1322 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1323 } 1324 ip = mtod(m, struct ip *); 1325 bcopy(p->ipopt_list, ip + 1, optlen); 1326 *phlen = sizeof(struct ip) + optlen; 1327 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1328 ip->ip_len += optlen; 1329 return (m); 1330 } 1331 1332 /* 1333 * Copy options from ip to jp, 1334 * omitting those not copied during fragmentation. 1335 */ 1336 int 1337 ip_optcopy(ip, jp) 1338 struct ip *ip, *jp; 1339 { 1340 u_char *cp, *dp; 1341 int opt, optlen, cnt; 1342 1343 cp = (u_char *)(ip + 1); 1344 dp = (u_char *)(jp + 1); 1345 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 1346 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1347 opt = cp[0]; 1348 if (opt == IPOPT_EOL) 1349 break; 1350 if (opt == IPOPT_NOP) { 1351 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1352 *dp++ = IPOPT_NOP; 1353 optlen = 1; 1354 continue; 1355 } 1356 1357 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1358 ("ip_optcopy: malformed ipv4 option")); 1359 optlen = cp[IPOPT_OLEN]; 1360 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1361 ("ip_optcopy: malformed ipv4 option")); 1362 1363 /* bogus lengths should have been caught by ip_dooptions */ 1364 if (optlen > cnt) 1365 optlen = cnt; 1366 if (IPOPT_COPIED(opt)) { 1367 bcopy(cp, dp, optlen); 1368 dp += optlen; 1369 } 1370 } 1371 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1372 *dp++ = IPOPT_EOL; 1373 return (optlen); 1374 } 1375 1376 /* 1377 * IP socket option processing. 1378 */ 1379 int 1380 ip_ctloutput(so, sopt) 1381 struct socket *so; 1382 struct sockopt *sopt; 1383 { 1384 struct inpcb *inp = sotoinpcb(so); 1385 int error, optval; 1386 1387 error = optval = 0; 1388 if (sopt->sopt_level != IPPROTO_IP) { 1389 return (EINVAL); 1390 } 1391 1392 switch (sopt->sopt_dir) { 1393 case SOPT_SET: 1394 switch (sopt->sopt_name) { 1395 case IP_OPTIONS: 1396 #ifdef notyet 1397 case IP_RETOPTS: 1398 #endif 1399 { 1400 struct mbuf *m; 1401 if (sopt->sopt_valsize > MLEN) { 1402 error = EMSGSIZE; 1403 break; 1404 } 1405 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1406 if (m == 0) { 1407 error = ENOBUFS; 1408 break; 1409 } 1410 m->m_len = sopt->sopt_valsize; 1411 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1412 m->m_len); 1413 1414 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1415 m)); 1416 } 1417 1418 case IP_TOS: 1419 case IP_TTL: 1420 case IP_RECVOPTS: 1421 case IP_RECVRETOPTS: 1422 case IP_RECVDSTADDR: 1423 case IP_RECVIF: 1424 case IP_FAITH: 1425 error = sooptcopyin(sopt, &optval, sizeof optval, 1426 sizeof optval); 1427 if (error) 1428 break; 1429 1430 switch (sopt->sopt_name) { 1431 case IP_TOS: 1432 inp->inp_ip_tos = optval; 1433 break; 1434 1435 case IP_TTL: 1436 inp->inp_ip_ttl = optval; 1437 break; 1438 #define OPTSET(bit) \ 1439 if (optval) \ 1440 inp->inp_flags |= bit; \ 1441 else \ 1442 inp->inp_flags &= ~bit; 1443 1444 case IP_RECVOPTS: 1445 OPTSET(INP_RECVOPTS); 1446 break; 1447 1448 case IP_RECVRETOPTS: 1449 OPTSET(INP_RECVRETOPTS); 1450 break; 1451 1452 case IP_RECVDSTADDR: 1453 OPTSET(INP_RECVDSTADDR); 1454 break; 1455 1456 case IP_RECVIF: 1457 OPTSET(INP_RECVIF); 1458 break; 1459 1460 case IP_FAITH: 1461 OPTSET(INP_FAITH); 1462 break; 1463 } 1464 break; 1465 #undef OPTSET 1466 1467 case IP_MULTICAST_IF: 1468 case IP_MULTICAST_VIF: 1469 case IP_MULTICAST_TTL: 1470 case IP_MULTICAST_LOOP: 1471 case IP_ADD_MEMBERSHIP: 1472 case IP_DROP_MEMBERSHIP: 1473 error = ip_setmoptions(sopt, &inp->inp_moptions); 1474 break; 1475 1476 case IP_PORTRANGE: 1477 error = sooptcopyin(sopt, &optval, sizeof optval, 1478 sizeof optval); 1479 if (error) 1480 break; 1481 1482 switch (optval) { 1483 case IP_PORTRANGE_DEFAULT: 1484 inp->inp_flags &= ~(INP_LOWPORT); 1485 inp->inp_flags &= ~(INP_HIGHPORT); 1486 break; 1487 1488 case IP_PORTRANGE_HIGH: 1489 inp->inp_flags &= ~(INP_LOWPORT); 1490 inp->inp_flags |= INP_HIGHPORT; 1491 break; 1492 1493 case IP_PORTRANGE_LOW: 1494 inp->inp_flags &= ~(INP_HIGHPORT); 1495 inp->inp_flags |= INP_LOWPORT; 1496 break; 1497 1498 default: 1499 error = EINVAL; 1500 break; 1501 } 1502 break; 1503 1504 #if defined(IPSEC) || defined(FAST_IPSEC) 1505 case IP_IPSEC_POLICY: 1506 { 1507 caddr_t req; 1508 size_t len = 0; 1509 int priv; 1510 struct mbuf *m; 1511 int optname; 1512 1513 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1514 break; 1515 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1516 break; 1517 priv = (sopt->sopt_td != NULL && 1518 suser(sopt->sopt_td) != 0) ? 0 : 1; 1519 req = mtod(m, caddr_t); 1520 len = m->m_len; 1521 optname = sopt->sopt_name; 1522 error = ipsec4_set_policy(inp, optname, req, len, priv); 1523 m_freem(m); 1524 break; 1525 } 1526 #endif /*IPSEC*/ 1527 1528 default: 1529 error = ENOPROTOOPT; 1530 break; 1531 } 1532 break; 1533 1534 case SOPT_GET: 1535 switch (sopt->sopt_name) { 1536 case IP_OPTIONS: 1537 case IP_RETOPTS: 1538 if (inp->inp_options) 1539 error = sooptcopyout(sopt, 1540 mtod(inp->inp_options, 1541 char *), 1542 inp->inp_options->m_len); 1543 else 1544 sopt->sopt_valsize = 0; 1545 break; 1546 1547 case IP_TOS: 1548 case IP_TTL: 1549 case IP_RECVOPTS: 1550 case IP_RECVRETOPTS: 1551 case IP_RECVDSTADDR: 1552 case IP_RECVIF: 1553 case IP_PORTRANGE: 1554 case IP_FAITH: 1555 switch (sopt->sopt_name) { 1556 1557 case IP_TOS: 1558 optval = inp->inp_ip_tos; 1559 break; 1560 1561 case IP_TTL: 1562 optval = inp->inp_ip_ttl; 1563 break; 1564 1565 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1566 1567 case IP_RECVOPTS: 1568 optval = OPTBIT(INP_RECVOPTS); 1569 break; 1570 1571 case IP_RECVRETOPTS: 1572 optval = OPTBIT(INP_RECVRETOPTS); 1573 break; 1574 1575 case IP_RECVDSTADDR: 1576 optval = OPTBIT(INP_RECVDSTADDR); 1577 break; 1578 1579 case IP_RECVIF: 1580 optval = OPTBIT(INP_RECVIF); 1581 break; 1582 1583 case IP_PORTRANGE: 1584 if (inp->inp_flags & INP_HIGHPORT) 1585 optval = IP_PORTRANGE_HIGH; 1586 else if (inp->inp_flags & INP_LOWPORT) 1587 optval = IP_PORTRANGE_LOW; 1588 else 1589 optval = 0; 1590 break; 1591 1592 case IP_FAITH: 1593 optval = OPTBIT(INP_FAITH); 1594 break; 1595 } 1596 error = sooptcopyout(sopt, &optval, sizeof optval); 1597 break; 1598 1599 case IP_MULTICAST_IF: 1600 case IP_MULTICAST_VIF: 1601 case IP_MULTICAST_TTL: 1602 case IP_MULTICAST_LOOP: 1603 case IP_ADD_MEMBERSHIP: 1604 case IP_DROP_MEMBERSHIP: 1605 error = ip_getmoptions(sopt, inp->inp_moptions); 1606 break; 1607 1608 #if defined(IPSEC) || defined(FAST_IPSEC) 1609 case IP_IPSEC_POLICY: 1610 { 1611 struct mbuf *m = NULL; 1612 caddr_t req = NULL; 1613 size_t len = 0; 1614 1615 if (m != 0) { 1616 req = mtod(m, caddr_t); 1617 len = m->m_len; 1618 } 1619 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1620 if (error == 0) 1621 error = soopt_mcopyout(sopt, m); /* XXX */ 1622 if (error == 0) 1623 m_freem(m); 1624 break; 1625 } 1626 #endif /*IPSEC*/ 1627 1628 default: 1629 error = ENOPROTOOPT; 1630 break; 1631 } 1632 break; 1633 } 1634 return (error); 1635 } 1636 1637 /* 1638 * Set up IP options in pcb for insertion in output packets. 1639 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1640 * with destination address if source routed. 1641 */ 1642 static int 1643 ip_pcbopts(optname, pcbopt, m) 1644 int optname; 1645 struct mbuf **pcbopt; 1646 struct mbuf *m; 1647 { 1648 int cnt, optlen; 1649 u_char *cp; 1650 u_char opt; 1651 1652 /* turn off any old options */ 1653 if (*pcbopt) 1654 (void)m_free(*pcbopt); 1655 *pcbopt = 0; 1656 if (m == (struct mbuf *)0 || m->m_len == 0) { 1657 /* 1658 * Only turning off any previous options. 1659 */ 1660 if (m) 1661 (void)m_free(m); 1662 return (0); 1663 } 1664 1665 if (m->m_len % sizeof(int32_t)) 1666 goto bad; 1667 /* 1668 * IP first-hop destination address will be stored before 1669 * actual options; move other options back 1670 * and clear it when none present. 1671 */ 1672 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1673 goto bad; 1674 cnt = m->m_len; 1675 m->m_len += sizeof(struct in_addr); 1676 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1677 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 1678 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1679 1680 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1681 opt = cp[IPOPT_OPTVAL]; 1682 if (opt == IPOPT_EOL) 1683 break; 1684 if (opt == IPOPT_NOP) 1685 optlen = 1; 1686 else { 1687 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1688 goto bad; 1689 optlen = cp[IPOPT_OLEN]; 1690 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1691 goto bad; 1692 } 1693 switch (opt) { 1694 1695 default: 1696 break; 1697 1698 case IPOPT_LSRR: 1699 case IPOPT_SSRR: 1700 /* 1701 * user process specifies route as: 1702 * ->A->B->C->D 1703 * D must be our final destination (but we can't 1704 * check that since we may not have connected yet). 1705 * A is first hop destination, which doesn't appear in 1706 * actual IP option, but is stored before the options. 1707 */ 1708 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1709 goto bad; 1710 m->m_len -= sizeof(struct in_addr); 1711 cnt -= sizeof(struct in_addr); 1712 optlen -= sizeof(struct in_addr); 1713 cp[IPOPT_OLEN] = optlen; 1714 /* 1715 * Move first hop before start of options. 1716 */ 1717 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1718 sizeof(struct in_addr)); 1719 /* 1720 * Then copy rest of options back 1721 * to close up the deleted entry. 1722 */ 1723 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1724 sizeof(struct in_addr)), 1725 &cp[IPOPT_OFFSET+1], 1726 (unsigned)cnt - (IPOPT_MINOFF - 1)); 1727 break; 1728 } 1729 } 1730 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1731 goto bad; 1732 *pcbopt = m; 1733 return (0); 1734 1735 bad: 1736 (void)m_free(m); 1737 return (EINVAL); 1738 } 1739 1740 /* 1741 * XXX 1742 * The whole multicast option thing needs to be re-thought. 1743 * Several of these options are equally applicable to non-multicast 1744 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1745 * standard option (IP_TTL). 1746 */ 1747 1748 /* 1749 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1750 */ 1751 static struct ifnet * 1752 ip_multicast_if(a, ifindexp) 1753 struct in_addr *a; 1754 int *ifindexp; 1755 { 1756 int ifindex; 1757 struct ifnet *ifp; 1758 1759 if (ifindexp) 1760 *ifindexp = 0; 1761 if (ntohl(a->s_addr) >> 24 == 0) { 1762 ifindex = ntohl(a->s_addr) & 0xffffff; 1763 if (ifindex < 0 || if_index < ifindex) 1764 return NULL; 1765 ifp = ifindex2ifnet[ifindex]; 1766 if (ifindexp) 1767 *ifindexp = ifindex; 1768 } else { 1769 INADDR_TO_IFP(*a, ifp); 1770 } 1771 return ifp; 1772 } 1773 1774 /* 1775 * Set the IP multicast options in response to user setsockopt(). 1776 */ 1777 static int 1778 ip_setmoptions(sopt, imop) 1779 struct sockopt *sopt; 1780 struct ip_moptions **imop; 1781 { 1782 int error = 0; 1783 int i; 1784 struct in_addr addr; 1785 struct ip_mreq mreq; 1786 struct ifnet *ifp; 1787 struct ip_moptions *imo = *imop; 1788 struct route ro; 1789 struct sockaddr_in *dst; 1790 int ifindex; 1791 int s; 1792 1793 if (imo == NULL) { 1794 /* 1795 * No multicast option buffer attached to the pcb; 1796 * allocate one and initialize to default values. 1797 */ 1798 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1799 M_WAITOK); 1800 1801 if (imo == NULL) 1802 return (ENOBUFS); 1803 *imop = imo; 1804 imo->imo_multicast_ifp = NULL; 1805 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1806 imo->imo_multicast_vif = -1; 1807 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1808 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1809 imo->imo_num_memberships = 0; 1810 } 1811 1812 switch (sopt->sopt_name) { 1813 /* store an index number for the vif you wanna use in the send */ 1814 case IP_MULTICAST_VIF: 1815 if (legal_vif_num == 0) { 1816 error = EOPNOTSUPP; 1817 break; 1818 } 1819 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1820 if (error) 1821 break; 1822 if (!legal_vif_num(i) && (i != -1)) { 1823 error = EINVAL; 1824 break; 1825 } 1826 imo->imo_multicast_vif = i; 1827 break; 1828 1829 case IP_MULTICAST_IF: 1830 /* 1831 * Select the interface for outgoing multicast packets. 1832 */ 1833 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1834 if (error) 1835 break; 1836 /* 1837 * INADDR_ANY is used to remove a previous selection. 1838 * When no interface is selected, a default one is 1839 * chosen every time a multicast packet is sent. 1840 */ 1841 if (addr.s_addr == INADDR_ANY) { 1842 imo->imo_multicast_ifp = NULL; 1843 break; 1844 } 1845 /* 1846 * The selected interface is identified by its local 1847 * IP address. Find the interface and confirm that 1848 * it supports multicasting. 1849 */ 1850 s = splimp(); 1851 ifp = ip_multicast_if(&addr, &ifindex); 1852 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1853 splx(s); 1854 error = EADDRNOTAVAIL; 1855 break; 1856 } 1857 imo->imo_multicast_ifp = ifp; 1858 if (ifindex) 1859 imo->imo_multicast_addr = addr; 1860 else 1861 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1862 splx(s); 1863 break; 1864 1865 case IP_MULTICAST_TTL: 1866 /* 1867 * Set the IP time-to-live for outgoing multicast packets. 1868 * The original multicast API required a char argument, 1869 * which is inconsistent with the rest of the socket API. 1870 * We allow either a char or an int. 1871 */ 1872 if (sopt->sopt_valsize == 1) { 1873 u_char ttl; 1874 error = sooptcopyin(sopt, &ttl, 1, 1); 1875 if (error) 1876 break; 1877 imo->imo_multicast_ttl = ttl; 1878 } else { 1879 u_int ttl; 1880 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1881 sizeof ttl); 1882 if (error) 1883 break; 1884 if (ttl > 255) 1885 error = EINVAL; 1886 else 1887 imo->imo_multicast_ttl = ttl; 1888 } 1889 break; 1890 1891 case IP_MULTICAST_LOOP: 1892 /* 1893 * Set the loopback flag for outgoing multicast packets. 1894 * Must be zero or one. The original multicast API required a 1895 * char argument, which is inconsistent with the rest 1896 * of the socket API. We allow either a char or an int. 1897 */ 1898 if (sopt->sopt_valsize == 1) { 1899 u_char loop; 1900 error = sooptcopyin(sopt, &loop, 1, 1); 1901 if (error) 1902 break; 1903 imo->imo_multicast_loop = !!loop; 1904 } else { 1905 u_int loop; 1906 error = sooptcopyin(sopt, &loop, sizeof loop, 1907 sizeof loop); 1908 if (error) 1909 break; 1910 imo->imo_multicast_loop = !!loop; 1911 } 1912 break; 1913 1914 case IP_ADD_MEMBERSHIP: 1915 /* 1916 * Add a multicast group membership. 1917 * Group must be a valid IP multicast address. 1918 */ 1919 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1920 if (error) 1921 break; 1922 1923 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1924 error = EINVAL; 1925 break; 1926 } 1927 s = splimp(); 1928 /* 1929 * If no interface address was provided, use the interface of 1930 * the route to the given multicast address. 1931 */ 1932 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1933 bzero((caddr_t)&ro, sizeof(ro)); 1934 dst = (struct sockaddr_in *)&ro.ro_dst; 1935 dst->sin_len = sizeof(*dst); 1936 dst->sin_family = AF_INET; 1937 dst->sin_addr = mreq.imr_multiaddr; 1938 rtalloc(&ro); 1939 if (ro.ro_rt == NULL) { 1940 error = EADDRNOTAVAIL; 1941 splx(s); 1942 break; 1943 } 1944 ifp = ro.ro_rt->rt_ifp; 1945 rtfree(ro.ro_rt); 1946 } 1947 else { 1948 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1949 } 1950 1951 /* 1952 * See if we found an interface, and confirm that it 1953 * supports multicast. 1954 */ 1955 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1956 error = EADDRNOTAVAIL; 1957 splx(s); 1958 break; 1959 } 1960 /* 1961 * See if the membership already exists or if all the 1962 * membership slots are full. 1963 */ 1964 for (i = 0; i < imo->imo_num_memberships; ++i) { 1965 if (imo->imo_membership[i]->inm_ifp == ifp && 1966 imo->imo_membership[i]->inm_addr.s_addr 1967 == mreq.imr_multiaddr.s_addr) 1968 break; 1969 } 1970 if (i < imo->imo_num_memberships) { 1971 error = EADDRINUSE; 1972 splx(s); 1973 break; 1974 } 1975 if (i == IP_MAX_MEMBERSHIPS) { 1976 error = ETOOMANYREFS; 1977 splx(s); 1978 break; 1979 } 1980 /* 1981 * Everything looks good; add a new record to the multicast 1982 * address list for the given interface. 1983 */ 1984 if ((imo->imo_membership[i] = 1985 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1986 error = ENOBUFS; 1987 splx(s); 1988 break; 1989 } 1990 ++imo->imo_num_memberships; 1991 splx(s); 1992 break; 1993 1994 case IP_DROP_MEMBERSHIP: 1995 /* 1996 * Drop a multicast group membership. 1997 * Group must be a valid IP multicast address. 1998 */ 1999 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2000 if (error) 2001 break; 2002 2003 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2004 error = EINVAL; 2005 break; 2006 } 2007 2008 s = splimp(); 2009 /* 2010 * If an interface address was specified, get a pointer 2011 * to its ifnet structure. 2012 */ 2013 if (mreq.imr_interface.s_addr == INADDR_ANY) 2014 ifp = NULL; 2015 else { 2016 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2017 if (ifp == NULL) { 2018 error = EADDRNOTAVAIL; 2019 splx(s); 2020 break; 2021 } 2022 } 2023 /* 2024 * Find the membership in the membership array. 2025 */ 2026 for (i = 0; i < imo->imo_num_memberships; ++i) { 2027 if ((ifp == NULL || 2028 imo->imo_membership[i]->inm_ifp == ifp) && 2029 imo->imo_membership[i]->inm_addr.s_addr == 2030 mreq.imr_multiaddr.s_addr) 2031 break; 2032 } 2033 if (i == imo->imo_num_memberships) { 2034 error = EADDRNOTAVAIL; 2035 splx(s); 2036 break; 2037 } 2038 /* 2039 * Give up the multicast address record to which the 2040 * membership points. 2041 */ 2042 in_delmulti(imo->imo_membership[i]); 2043 /* 2044 * Remove the gap in the membership array. 2045 */ 2046 for (++i; i < imo->imo_num_memberships; ++i) 2047 imo->imo_membership[i-1] = imo->imo_membership[i]; 2048 --imo->imo_num_memberships; 2049 splx(s); 2050 break; 2051 2052 default: 2053 error = EOPNOTSUPP; 2054 break; 2055 } 2056 2057 /* 2058 * If all options have default values, no need to keep the mbuf. 2059 */ 2060 if (imo->imo_multicast_ifp == NULL && 2061 imo->imo_multicast_vif == -1 && 2062 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2063 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2064 imo->imo_num_memberships == 0) { 2065 free(*imop, M_IPMOPTS); 2066 *imop = NULL; 2067 } 2068 2069 return (error); 2070 } 2071 2072 /* 2073 * Return the IP multicast options in response to user getsockopt(). 2074 */ 2075 static int 2076 ip_getmoptions(sopt, imo) 2077 struct sockopt *sopt; 2078 struct ip_moptions *imo; 2079 { 2080 struct in_addr addr; 2081 struct in_ifaddr *ia; 2082 int error, optval; 2083 u_char coptval; 2084 2085 error = 0; 2086 switch (sopt->sopt_name) { 2087 case IP_MULTICAST_VIF: 2088 if (imo != NULL) 2089 optval = imo->imo_multicast_vif; 2090 else 2091 optval = -1; 2092 error = sooptcopyout(sopt, &optval, sizeof optval); 2093 break; 2094 2095 case IP_MULTICAST_IF: 2096 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2097 addr.s_addr = INADDR_ANY; 2098 else if (imo->imo_multicast_addr.s_addr) { 2099 /* return the value user has set */ 2100 addr = imo->imo_multicast_addr; 2101 } else { 2102 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2103 addr.s_addr = (ia == NULL) ? INADDR_ANY 2104 : IA_SIN(ia)->sin_addr.s_addr; 2105 } 2106 error = sooptcopyout(sopt, &addr, sizeof addr); 2107 break; 2108 2109 case IP_MULTICAST_TTL: 2110 if (imo == 0) 2111 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2112 else 2113 optval = coptval = imo->imo_multicast_ttl; 2114 if (sopt->sopt_valsize == 1) 2115 error = sooptcopyout(sopt, &coptval, 1); 2116 else 2117 error = sooptcopyout(sopt, &optval, sizeof optval); 2118 break; 2119 2120 case IP_MULTICAST_LOOP: 2121 if (imo == 0) 2122 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2123 else 2124 optval = coptval = imo->imo_multicast_loop; 2125 if (sopt->sopt_valsize == 1) 2126 error = sooptcopyout(sopt, &coptval, 1); 2127 else 2128 error = sooptcopyout(sopt, &optval, sizeof optval); 2129 break; 2130 2131 default: 2132 error = ENOPROTOOPT; 2133 break; 2134 } 2135 return (error); 2136 } 2137 2138 /* 2139 * Discard the IP multicast options. 2140 */ 2141 void 2142 ip_freemoptions(imo) 2143 struct ip_moptions *imo; 2144 { 2145 int i; 2146 2147 if (imo != NULL) { 2148 for (i = 0; i < imo->imo_num_memberships; ++i) 2149 in_delmulti(imo->imo_membership[i]); 2150 free(imo, M_IPMOPTS); 2151 } 2152 } 2153 2154 /* 2155 * Routine called from ip_output() to loop back a copy of an IP multicast 2156 * packet to the input queue of a specified interface. Note that this 2157 * calls the output routine of the loopback "driver", but with an interface 2158 * pointer that might NOT be a loopback interface -- evil, but easier than 2159 * replicating that code here. 2160 */ 2161 static void 2162 ip_mloopback(ifp, m, dst, hlen) 2163 struct ifnet *ifp; 2164 struct mbuf *m; 2165 struct sockaddr_in *dst; 2166 int hlen; 2167 { 2168 struct ip *ip; 2169 struct mbuf *copym; 2170 2171 copym = m_copy(m, 0, M_COPYALL); 2172 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2173 copym = m_pullup(copym, hlen); 2174 if (copym != NULL) { 2175 /* 2176 * if the checksum hasn't been computed, mark it as valid 2177 */ 2178 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2179 in_delayed_cksum(copym); 2180 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2181 copym->m_pkthdr.csum_flags |= 2182 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2183 copym->m_pkthdr.csum_data = 0xffff; 2184 } 2185 /* 2186 * We don't bother to fragment if the IP length is greater 2187 * than the interface's MTU. Can this possibly matter? 2188 */ 2189 ip = mtod(copym, struct ip *); 2190 ip->ip_len = htons(ip->ip_len); 2191 ip->ip_off = htons(ip->ip_off); 2192 ip->ip_sum = 0; 2193 if (ip->ip_vhl == IP_VHL_BORING) { 2194 ip->ip_sum = in_cksum_hdr(ip); 2195 } else { 2196 ip->ip_sum = in_cksum(copym, hlen); 2197 } 2198 /* 2199 * NB: 2200 * It's not clear whether there are any lingering 2201 * reentrancy problems in other areas which might 2202 * be exposed by using ip_input directly (in 2203 * particular, everything which modifies the packet 2204 * in-place). Yet another option is using the 2205 * protosw directly to deliver the looped back 2206 * packet. For the moment, we'll err on the side 2207 * of safety by using if_simloop(). 2208 */ 2209 #if 1 /* XXX */ 2210 if (dst->sin_family != AF_INET) { 2211 printf("ip_mloopback: bad address family %d\n", 2212 dst->sin_family); 2213 dst->sin_family = AF_INET; 2214 } 2215 #endif 2216 2217 #ifdef notdef 2218 copym->m_pkthdr.rcvif = ifp; 2219 ip_input(copym); 2220 #else 2221 if_simloop(ifp, copym, dst->sin_family, 0); 2222 #endif 2223 } 2224 } 2225