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 1.20 2004/08/26 21:21:46 dillon Exp $ 32 */ 33 34 #define _IP_VHL 35 36 #include "opt_ipfw.h" 37 #include "opt_ipdn.h" 38 #include "opt_ipdivert.h" 39 #include "opt_ipfilter.h" 40 #include "opt_ipsec.h" 41 #include "opt_random_ip_id.h" 42 #include "opt_mbuf_stress_test.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/sysctl.h> 54 #include <sys/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 <netipsec/ipsec.h> 82 #include <netipsec/xform.h> 83 #include <netipsec/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 #ifdef IPSEC 138 struct route iproute; 139 struct secpolicy *sp = NULL; 140 struct socket *so = inp ? inp->inp_socket : NULL; 141 #endif 142 #ifdef FAST_IPSEC 143 struct route iproute; 144 struct m_tag *mtag; 145 struct secpolicy *sp = NULL; 146 struct tdb_ident *tdbi; 147 int s; 148 #endif /* FAST_IPSEC */ 149 struct ip_fw_args args; 150 int src_was_INADDR_ANY = 0; /* as the name says... */ 151 152 args.eh = NULL; 153 args.rule = NULL; 154 args.next_hop = NULL; 155 args.divert_rule = 0; /* divert cookie */ 156 157 /* Grab info from MT_TAG mbufs prepended to the chain. */ 158 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) { 159 switch(m0->_m_tag_id) { 160 default: 161 printf("ip_output: unrecognised MT_TAG tag %d\n", 162 m0->_m_tag_id); 163 break; 164 165 case PACKET_TAG_DUMMYNET: 166 /* 167 * the packet was already tagged, so part of the 168 * processing was already done, and we need to go down. 169 * Get parameters from the header. 170 */ 171 args.rule = ((struct dn_pkt *)m0)->rule; 172 opt = NULL ; 173 ro = & ( ((struct dn_pkt *)m0)->ro ) ; 174 imo = NULL ; 175 dst = ((struct dn_pkt *)m0)->dn_dst ; 176 ifp = ((struct dn_pkt *)m0)->ifp ; 177 flags = ((struct dn_pkt *)m0)->flags ; 178 break; 179 180 case PACKET_TAG_DIVERT: 181 args.divert_rule = (int)m0->m_data & 0xffff; 182 break; 183 184 case PACKET_TAG_IPFORWARD: 185 args.next_hop = (struct sockaddr_in *)m0->m_data; 186 break; 187 } 188 } 189 m = m0; 190 191 KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR")); 192 #ifndef FAST_IPSEC 193 KASSERT(ro != NULL, ("ip_output: no route, proto %d", 194 mtod(m, struct ip *)->ip_p)); 195 #endif 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 #ifdef FAST_IPSEC 231 if (ro == NULL) { 232 ro = &iproute; 233 bzero(ro, sizeof (*ro)); 234 } 235 #endif /* FAST_IPSEC */ 236 dst = (struct sockaddr_in *)&ro->ro_dst; 237 /* 238 * If there is a cached route, 239 * check that it is to the same destination 240 * and is still up. If not, free it and try again. 241 * The address family should also be checked in case of sharing the 242 * cache with IPv6. 243 */ 244 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 245 dst->sin_family != AF_INET || 246 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 247 RTFREE(ro->ro_rt); 248 ro->ro_rt = (struct rtentry *)0; 249 } 250 if (ro->ro_rt == 0) { 251 bzero(dst, sizeof(*dst)); 252 dst->sin_family = AF_INET; 253 dst->sin_len = sizeof(*dst); 254 dst->sin_addr = pkt_dst; 255 } 256 /* 257 * If routing to interface only, 258 * short circuit routing lookup. 259 */ 260 if (flags & IP_ROUTETOIF) { 261 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 262 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 263 ipstat.ips_noroute++; 264 error = ENETUNREACH; 265 goto bad; 266 } 267 ifp = ia->ia_ifp; 268 ip->ip_ttl = 1; 269 isbroadcast = in_broadcast(dst->sin_addr, ifp); 270 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 271 imo != NULL && imo->imo_multicast_ifp != NULL) { 272 /* 273 * Bypass the normal routing lookup for multicast 274 * packets if the interface is specified. 275 */ 276 ifp = imo->imo_multicast_ifp; 277 IFP_TO_IA(ifp, ia); 278 isbroadcast = 0; /* fool gcc */ 279 } else { 280 /* 281 * If this is the case, we probably don't want to allocate 282 * a protocol-cloned route since we didn't get one from the 283 * ULP. This lets TCP do its thing, while not burdening 284 * forwarding or ICMP with the overhead of cloning a route. 285 * Of course, we still want to do any cloning requested by 286 * the link layer, as this is probably required in all cases 287 * for correct operation (as it is for ARP). 288 */ 289 if (ro->ro_rt == 0) 290 rtalloc_ign(ro, RTF_PRCLONING); 291 if (ro->ro_rt == 0) { 292 ipstat.ips_noroute++; 293 error = EHOSTUNREACH; 294 goto bad; 295 } 296 ia = ifatoia(ro->ro_rt->rt_ifa); 297 ifp = ro->ro_rt->rt_ifp; 298 ro->ro_rt->rt_use++; 299 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 300 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 301 if (ro->ro_rt->rt_flags & RTF_HOST) 302 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 303 else 304 isbroadcast = in_broadcast(dst->sin_addr, ifp); 305 } 306 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 307 struct in_multi *inm; 308 309 m->m_flags |= M_MCAST; 310 /* 311 * IP destination address is multicast. Make sure "dst" 312 * still points to the address in "ro". (It may have been 313 * changed to point to a gateway address, above.) 314 */ 315 dst = (struct sockaddr_in *)&ro->ro_dst; 316 /* 317 * See if the caller provided any multicast options 318 */ 319 if (imo != NULL) { 320 ip->ip_ttl = imo->imo_multicast_ttl; 321 if (imo->imo_multicast_vif != -1) 322 ip->ip_src.s_addr = 323 ip_mcast_src ? 324 ip_mcast_src(imo->imo_multicast_vif) : 325 INADDR_ANY; 326 } else 327 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 328 /* 329 * Confirm that the outgoing interface supports multicast. 330 */ 331 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 332 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 333 ipstat.ips_noroute++; 334 error = ENETUNREACH; 335 goto bad; 336 } 337 } 338 /* 339 * If source address not specified yet, use address 340 * of outgoing interface. 341 */ 342 if (ip->ip_src.s_addr == INADDR_ANY) { 343 /* Interface may have no addresses. */ 344 if (ia != NULL) 345 ip->ip_src = IA_SIN(ia)->sin_addr; 346 } 347 348 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 349 if (inm != NULL && 350 (imo == NULL || imo->imo_multicast_loop)) { 351 /* 352 * If we belong to the destination multicast group 353 * on the outgoing interface, and the caller did not 354 * forbid loopback, loop back a copy. 355 */ 356 ip_mloopback(ifp, m, dst, hlen); 357 } 358 else { 359 /* 360 * If we are acting as a multicast router, perform 361 * multicast forwarding as if the packet had just 362 * arrived on the interface to which we are about 363 * to send. The multicast forwarding function 364 * recursively calls this function, using the 365 * IP_FORWARDING flag to prevent infinite recursion. 366 * 367 * Multicasts that are looped back by ip_mloopback(), 368 * above, will be forwarded by the ip_input() routine, 369 * if necessary. 370 */ 371 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 372 /* 373 * If rsvp daemon is not running, do not 374 * set ip_moptions. This ensures that the packet 375 * is multicast and not just sent down one link 376 * as prescribed by rsvpd. 377 */ 378 if (!rsvp_on) 379 imo = NULL; 380 if (ip_mforward && 381 ip_mforward(ip, ifp, m, imo) != 0) { 382 m_freem(m); 383 goto done; 384 } 385 } 386 } 387 388 /* 389 * Multicasts with a time-to-live of zero may be looped- 390 * back, above, but must not be transmitted on a network. 391 * Also, multicasts addressed to the loopback interface 392 * are not sent -- the above call to ip_mloopback() will 393 * loop back a copy if this host actually belongs to the 394 * destination group on the loopback interface. 395 */ 396 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 397 m_freem(m); 398 goto done; 399 } 400 401 goto sendit; 402 } 403 #ifndef notdef 404 /* 405 * If the source address is not specified yet, use the address 406 * of the outoing interface. In case, keep note we did that, so 407 * if the the firewall changes the next-hop causing the output 408 * interface to change, we can fix that. 409 */ 410 if (ip->ip_src.s_addr == INADDR_ANY) { 411 /* Interface may have no addresses. */ 412 if (ia != NULL) { 413 ip->ip_src = IA_SIN(ia)->sin_addr; 414 src_was_INADDR_ANY = 1; 415 } 416 } 417 #endif /* notdef */ 418 /* 419 * Verify that we have any chance at all of being able to queue 420 * the packet or packet fragments 421 */ 422 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 423 ifp->if_snd.ifq_maxlen) { 424 error = ENOBUFS; 425 ipstat.ips_odropped++; 426 goto bad; 427 } 428 429 /* 430 * Look for broadcast address and 431 * verify user is allowed to send 432 * such a packet. 433 */ 434 if (isbroadcast) { 435 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 436 error = EADDRNOTAVAIL; 437 goto bad; 438 } 439 if ((flags & IP_ALLOWBROADCAST) == 0) { 440 error = EACCES; 441 goto bad; 442 } 443 /* don't allow broadcast messages to be fragmented */ 444 if (ip->ip_len > ifp->if_mtu) { 445 error = EMSGSIZE; 446 goto bad; 447 } 448 m->m_flags |= M_BCAST; 449 } else { 450 m->m_flags &= ~M_BCAST; 451 } 452 453 sendit: 454 #ifdef IPSEC 455 /* get SP for this packet */ 456 if (so == NULL) 457 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 458 else 459 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 460 461 if (sp == NULL) { 462 ipsecstat.out_inval++; 463 goto bad; 464 } 465 466 error = 0; 467 468 /* check policy */ 469 switch (sp->policy) { 470 case IPSEC_POLICY_DISCARD: 471 /* 472 * This packet is just discarded. 473 */ 474 ipsecstat.out_polvio++; 475 goto bad; 476 477 case IPSEC_POLICY_BYPASS: 478 case IPSEC_POLICY_NONE: 479 /* no need to do IPsec. */ 480 goto skip_ipsec; 481 482 case IPSEC_POLICY_IPSEC: 483 if (sp->req == NULL) { 484 /* acquire a policy */ 485 error = key_spdacquire(sp); 486 goto bad; 487 } 488 break; 489 490 case IPSEC_POLICY_ENTRUST: 491 default: 492 printf("ip_output: Invalid policy found. %d\n", sp->policy); 493 } 494 { 495 struct ipsec_output_state state; 496 bzero(&state, sizeof(state)); 497 state.m = m; 498 if (flags & IP_ROUTETOIF) { 499 state.ro = &iproute; 500 bzero(&iproute, sizeof(iproute)); 501 } else 502 state.ro = ro; 503 state.dst = (struct sockaddr *)dst; 504 505 ip->ip_sum = 0; 506 507 /* 508 * XXX 509 * delayed checksums are not currently compatible with IPsec 510 */ 511 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 512 in_delayed_cksum(m); 513 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 514 } 515 516 ip->ip_len = htons(ip->ip_len); 517 ip->ip_off = htons(ip->ip_off); 518 519 error = ipsec4_output(&state, sp, flags); 520 521 m = state.m; 522 if (flags & IP_ROUTETOIF) { 523 /* 524 * if we have tunnel mode SA, we may need to ignore 525 * IP_ROUTETOIF. 526 */ 527 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 528 flags &= ~IP_ROUTETOIF; 529 ro = state.ro; 530 } 531 } else 532 ro = state.ro; 533 dst = (struct sockaddr_in *)state.dst; 534 if (error) { 535 /* mbuf is already reclaimed in ipsec4_output. */ 536 m0 = NULL; 537 switch (error) { 538 case EHOSTUNREACH: 539 case ENETUNREACH: 540 case EMSGSIZE: 541 case ENOBUFS: 542 case ENOMEM: 543 break; 544 default: 545 printf("ip4_output (ipsec): error code %d\n", error); 546 /*fall through*/ 547 case ENOENT: 548 /* don't show these error codes to the user */ 549 error = 0; 550 break; 551 } 552 goto bad; 553 } 554 } 555 556 /* be sure to update variables that are affected by ipsec4_output() */ 557 ip = mtod(m, struct ip *); 558 #ifdef _IP_VHL 559 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 560 #else 561 hlen = ip->ip_hl << 2; 562 #endif 563 if (ro->ro_rt == NULL) { 564 if ((flags & IP_ROUTETOIF) == 0) { 565 printf("ip_output: " 566 "can't update route after IPsec processing\n"); 567 error = EHOSTUNREACH; /*XXX*/ 568 goto bad; 569 } 570 } else { 571 ia = ifatoia(ro->ro_rt->rt_ifa); 572 ifp = ro->ro_rt->rt_ifp; 573 } 574 575 /* make it flipped, again. */ 576 ip->ip_len = ntohs(ip->ip_len); 577 ip->ip_off = ntohs(ip->ip_off); 578 skip_ipsec: 579 #endif /*IPSEC*/ 580 #ifdef FAST_IPSEC 581 /* 582 * Check the security policy (SP) for the packet and, if 583 * required, do IPsec-related processing. There are two 584 * cases here; the first time a packet is sent through 585 * it will be untagged and handled by ipsec4_checkpolicy. 586 * If the packet is resubmitted to ip_output (e.g. after 587 * AH, ESP, etc. processing), there will be a tag to bypass 588 * the lookup and related policy checking. 589 */ 590 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 591 s = splnet(); 592 if (mtag != NULL) { 593 tdbi = (struct tdb_ident *)(mtag + 1); 594 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 595 if (sp == NULL) 596 error = -EINVAL; /* force silent drop */ 597 m_tag_delete(m, mtag); 598 } else { 599 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 600 &error, inp); 601 } 602 /* 603 * There are four return cases: 604 * sp != NULL apply IPsec policy 605 * sp == NULL, error == 0 no IPsec handling needed 606 * sp == NULL, error == -EINVAL discard packet w/o error 607 * sp == NULL, error != 0 discard packet, report error 608 */ 609 if (sp != NULL) { 610 /* Loop detection, check if ipsec processing already done */ 611 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 612 for (mtag = m_tag_first(m); mtag != NULL; 613 mtag = m_tag_next(m, mtag)) { 614 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 615 continue; 616 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 617 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 618 continue; 619 /* 620 * Check if policy has an SA associated with it. 621 * This can happen when an SP has yet to acquire 622 * an SA; e.g. on first reference. If it occurs, 623 * then we let ipsec4_process_packet do its thing. 624 */ 625 if (sp->req->sav == NULL) 626 break; 627 tdbi = (struct tdb_ident *)(mtag + 1); 628 if (tdbi->spi == sp->req->sav->spi && 629 tdbi->proto == sp->req->sav->sah->saidx.proto && 630 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 631 sizeof (union sockaddr_union)) == 0) { 632 /* 633 * No IPsec processing is needed, free 634 * reference to SP. 635 * 636 * NB: null pointer to avoid free at 637 * done: below. 638 */ 639 KEY_FREESP(&sp), sp = NULL; 640 splx(s); 641 goto spd_done; 642 } 643 } 644 645 /* 646 * Do delayed checksums now because we send before 647 * this is done in the normal processing path. 648 */ 649 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 650 in_delayed_cksum(m); 651 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 652 } 653 654 ip->ip_len = htons(ip->ip_len); 655 ip->ip_off = htons(ip->ip_off); 656 657 /* NB: callee frees mbuf */ 658 error = ipsec4_process_packet(m, sp->req, flags, 0); 659 /* 660 * Preserve KAME behaviour: ENOENT can be returned 661 * when an SA acquire is in progress. Don't propagate 662 * this to user-level; it confuses applications. 663 * 664 * XXX this will go away when the SADB is redone. 665 */ 666 if (error == ENOENT) 667 error = 0; 668 splx(s); 669 goto done; 670 } else { 671 splx(s); 672 673 if (error != 0) { 674 /* 675 * Hack: -EINVAL is used to signal that a packet 676 * should be silently discarded. This is typically 677 * because we asked key management for an SA and 678 * it was delayed (e.g. kicked up to IKE). 679 */ 680 if (error == -EINVAL) 681 error = 0; 682 goto bad; 683 } else { 684 /* No IPsec processing for this packet. */ 685 } 686 #ifdef notyet 687 /* 688 * If deferred crypto processing is needed, check that 689 * the interface supports it. 690 */ 691 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 692 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 693 /* notify IPsec to do its own crypto */ 694 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 695 error = EHOSTUNREACH; 696 goto bad; 697 } 698 #endif 699 } 700 spd_done: 701 #endif /* FAST_IPSEC */ 702 /* 703 * IpHack's section. 704 * - Xlate: translate packet's addr/port (NAT). 705 * - Firewall: deny/allow/etc. 706 * - Wrap: fake packet's addr/port <unimpl.> 707 * - Encapsulate: put it in another IP and send out. <unimp.> 708 */ 709 710 /* 711 * Run through list of hooks for output packets. 712 */ 713 if (pfil_has_hooks(&inet_pfil_hook)) { 714 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 715 if (error != 0 || m == NULL) 716 goto done; 717 ip = mtod(m, struct ip *); 718 } 719 720 /* 721 * Check with the firewall... 722 * but not if we are already being fwd'd from a firewall. 723 */ 724 if (fw_enable && IPFW_LOADED && !args.next_hop) { 725 struct sockaddr_in *old = dst; 726 727 args.m = m; 728 args.next_hop = dst; 729 args.oif = ifp; 730 off = ip_fw_chk_ptr(&args); 731 m = args.m; 732 dst = args.next_hop; 733 734 /* 735 * On return we must do the following: 736 * m == NULL -> drop the pkt (old interface, deprecated) 737 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 738 * 1<=off<= 0xffff -> DIVERT 739 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 740 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 741 * dst != old -> IPFIREWALL_FORWARD 742 * off==0, dst==old -> accept 743 * If some of the above modules are not compiled in, then 744 * we should't have to check the corresponding condition 745 * (because the ipfw control socket should not accept 746 * unsupported rules), but better play safe and drop 747 * packets in case of doubt. 748 */ 749 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 750 if (m) 751 m_freem(m); 752 error = EACCES; 753 goto done; 754 } 755 ip = mtod(m, struct ip *); 756 if (off == 0 && dst == old) /* common case */ 757 goto pass; 758 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { 759 /* 760 * pass the pkt to dummynet. Need to include 761 * pipe number, m, ifp, ro, dst because these are 762 * not recomputed in the next pass. 763 * All other parameters have been already used and 764 * so they are not needed anymore. 765 * XXX note: if the ifp or ro entry are deleted 766 * while a pkt is in dummynet, we are in trouble! 767 */ 768 args.ro = ro; 769 args.dst = dst; 770 args.flags = flags; 771 772 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 773 &args); 774 goto done; 775 } 776 #ifdef IPDIVERT 777 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { 778 struct mbuf *clone = NULL; 779 780 /* Clone packet if we're doing a 'tee' */ 781 if ((off & IP_FW_PORT_TEE_FLAG) != 0) 782 clone = m_dup(m, MB_DONTWAIT); 783 784 /* 785 * XXX 786 * delayed checksums are not currently compatible 787 * with divert sockets. 788 */ 789 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 790 in_delayed_cksum(m); 791 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 792 } 793 794 /* Restore packet header fields to original values */ 795 ip->ip_len = htons(ip->ip_len); 796 ip->ip_off = htons(ip->ip_off); 797 798 /* Deliver packet to divert input routine */ 799 divert_packet(m, 0, off & 0xffff, args.divert_rule); 800 801 /* If 'tee', continue with original packet */ 802 if (clone != NULL) { 803 m = clone; 804 ip = mtod(m, struct ip *); 805 goto pass; 806 } 807 goto done; 808 } 809 #endif 810 811 /* IPFIREWALL_FORWARD */ 812 /* 813 * Check dst to make sure it is directly reachable on the 814 * interface we previously thought it was. 815 * If it isn't (which may be likely in some situations) we have 816 * to re-route it (ie, find a route for the next-hop and the 817 * associated interface) and set them here. This is nested 818 * forwarding which in most cases is undesirable, except where 819 * such control is nigh impossible. So we do it here. 820 * And I'm babbling. 821 */ 822 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 823 #if 0 824 /* 825 * XXX To improve readability, this block should be 826 * changed into a function call as below: 827 */ 828 error = ip_ipforward(&m, &dst, &ifp); 829 if (error) 830 goto bad; 831 if (m == NULL) /* ip_input consumed the mbuf */ 832 goto done; 833 #else 834 struct in_ifaddr *ia; 835 836 /* 837 * XXX sro_fwd below is static, and a pointer 838 * to it gets passed to routines downstream. 839 * This could have surprisingly bad results in 840 * practice, because its content is overwritten 841 * by subsequent packets. 842 */ 843 /* There must be a better way to do this next line... */ 844 static struct route sro_fwd; 845 struct route *ro_fwd = &sro_fwd; 846 847 #if 0 848 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 849 dst->sin_addr, "\n"); 850 #endif 851 852 /* 853 * We need to figure out if we have been forwarded 854 * to a local socket. If so, then we should somehow 855 * "loop back" to ip_input, and get directed to the 856 * PCB as if we had received this packet. This is 857 * because it may be dificult to identify the packets 858 * you want to forward until they are being output 859 * and have selected an interface. (e.g. locally 860 * initiated packets) If we used the loopback inteface, 861 * we would not be able to control what happens 862 * as the packet runs through ip_input() as 863 * it is done through a ISR. 864 */ 865 LIST_FOREACH(ia, 866 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 867 /* 868 * If the addr to forward to is one 869 * of ours, we pretend to 870 * be the destination for this packet. 871 */ 872 if (IA_SIN(ia)->sin_addr.s_addr == 873 dst->sin_addr.s_addr) 874 break; 875 } 876 if (ia) { /* tell ip_input "dont filter" */ 877 struct m_hdr tag; 878 879 tag.mh_type = MT_TAG; 880 tag.mh_flags = PACKET_TAG_IPFORWARD; 881 tag.mh_data = (caddr_t)args.next_hop; 882 tag.mh_next = m; 883 884 if (m->m_pkthdr.rcvif == NULL) 885 m->m_pkthdr.rcvif = ifunit("lo0"); 886 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 887 m->m_pkthdr.csum_flags |= 888 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 889 m0->m_pkthdr.csum_data = 0xffff; 890 } 891 m->m_pkthdr.csum_flags |= 892 CSUM_IP_CHECKED | CSUM_IP_VALID; 893 ip->ip_len = htons(ip->ip_len); 894 ip->ip_off = htons(ip->ip_off); 895 ip_input((struct mbuf *)&tag); 896 goto done; 897 } 898 /* Some of the logic for this was 899 * nicked from above. 900 * 901 * This rewrites the cached route in a local PCB. 902 * Is this what we want to do? 903 */ 904 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 905 906 ro_fwd->ro_rt = 0; 907 rtalloc_ign(ro_fwd, RTF_PRCLONING); 908 909 if (ro_fwd->ro_rt == 0) { 910 ipstat.ips_noroute++; 911 error = EHOSTUNREACH; 912 goto bad; 913 } 914 915 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 916 ifp = ro_fwd->ro_rt->rt_ifp; 917 ro_fwd->ro_rt->rt_use++; 918 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 919 dst = (struct sockaddr_in *) 920 ro_fwd->ro_rt->rt_gateway; 921 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 922 isbroadcast = 923 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 924 else 925 isbroadcast = in_broadcast(dst->sin_addr, ifp); 926 if (ro->ro_rt) 927 RTFREE(ro->ro_rt); 928 ro->ro_rt = ro_fwd->ro_rt; 929 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 930 931 #endif /* ... block to be put into a function */ 932 /* 933 * If we added a default src ip earlier, 934 * which would have been gotten from the-then 935 * interface, do it again, from the new one. 936 */ 937 if (src_was_INADDR_ANY) 938 ip->ip_src = IA_SIN(ia)->sin_addr; 939 goto pass ; 940 } 941 942 /* 943 * if we get here, none of the above matches, and 944 * we have to drop the pkt 945 */ 946 m_freem(m); 947 error = EACCES; /* not sure this is the right error msg */ 948 goto done; 949 } 950 951 pass: 952 /* 127/8 must not appear on wire - RFC1122. */ 953 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 954 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 955 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 956 ipstat.ips_badaddr++; 957 error = EADDRNOTAVAIL; 958 goto bad; 959 } 960 } 961 962 m->m_pkthdr.csum_flags |= CSUM_IP; 963 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 964 if (sw_csum & CSUM_DELAY_DATA) { 965 in_delayed_cksum(m); 966 sw_csum &= ~CSUM_DELAY_DATA; 967 } 968 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 969 970 /* 971 * If small enough for interface, or the interface will take 972 * care of the fragmentation for us, can just send directly. 973 */ 974 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 975 (ip->ip_off & IP_DF) == 0)) { 976 ip->ip_len = htons(ip->ip_len); 977 ip->ip_off = htons(ip->ip_off); 978 ip->ip_sum = 0; 979 if (sw_csum & CSUM_DELAY_IP) { 980 if (ip->ip_vhl == IP_VHL_BORING) { 981 ip->ip_sum = in_cksum_hdr(ip); 982 } else { 983 ip->ip_sum = in_cksum(m, hlen); 984 } 985 } 986 987 /* Record statistics for this interface address. */ 988 if (!(flags & IP_FORWARDING) && ia) { 989 ia->ia_ifa.if_opackets++; 990 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 991 } 992 993 #ifdef IPSEC 994 /* clean ipsec history once it goes out of the node */ 995 ipsec_delaux(m); 996 #endif 997 998 #ifdef MBUF_STRESS_TEST 999 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 1000 struct mbuf *m1, *m2; 1001 int length, tmp; 1002 1003 tmp = length = m->m_pkthdr.len; 1004 1005 while ((length -= mbuf_frag_size) >= 1) { 1006 m1 = m_split(m, length, MB_DONTWAIT); 1007 if (m1 == NULL) 1008 break; 1009 m1->m_flags &= ~M_PKTHDR; 1010 m2 = m; 1011 while (m2->m_next != NULL) 1012 m2 = m2->m_next; 1013 m2->m_next = m1; 1014 } 1015 m->m_pkthdr.len = tmp; 1016 } 1017 #endif 1018 error = (*ifp->if_output)(ifp, m, 1019 (struct sockaddr *)dst, ro->ro_rt); 1020 goto done; 1021 } 1022 1023 if (ip->ip_off & IP_DF) { 1024 error = EMSGSIZE; 1025 /* 1026 * This case can happen if the user changed the MTU 1027 * of an interface after enabling IP on it. Because 1028 * most netifs don't keep track of routes pointing to 1029 * them, there is no way for one to update all its 1030 * routes when the MTU is changed. 1031 */ 1032 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1033 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1034 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1035 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1036 } 1037 ipstat.ips_cantfrag++; 1038 goto bad; 1039 } 1040 1041 /* 1042 * Too large for interface; fragment if possible. If successful, 1043 * on return, m will point to a list of packets to be sent. 1044 */ 1045 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1046 if (error) 1047 goto bad; 1048 for (; m; m = m0) { 1049 m0 = m->m_nextpkt; 1050 m->m_nextpkt = 0; 1051 #ifdef IPSEC 1052 /* clean ipsec history once it goes out of the node */ 1053 ipsec_delaux(m); 1054 #endif 1055 if (error == 0) { 1056 /* Record statistics for this interface address. */ 1057 if (ia != NULL) { 1058 ia->ia_ifa.if_opackets++; 1059 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1060 } 1061 1062 error = (*ifp->if_output)(ifp, m, 1063 (struct sockaddr *)dst, ro->ro_rt); 1064 } else 1065 m_freem(m); 1066 } 1067 1068 if (error == 0) 1069 ipstat.ips_fragmented++; 1070 1071 done: 1072 #ifdef IPSEC 1073 if (ro == &iproute && ro->ro_rt) { 1074 RTFREE(ro->ro_rt); 1075 ro->ro_rt = NULL; 1076 } 1077 if (sp != NULL) { 1078 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1079 printf("DP ip_output call free SP:%p\n", sp)); 1080 key_freesp(sp); 1081 } 1082 #endif 1083 #ifdef FAST_IPSEC 1084 if (ro == &iproute && ro->ro_rt) { 1085 RTFREE(ro->ro_rt); 1086 ro->ro_rt = NULL; 1087 } 1088 if (sp != NULL) 1089 KEY_FREESP(&sp); 1090 #endif 1091 return (error); 1092 bad: 1093 m_freem(m); 1094 goto done; 1095 } 1096 1097 /* 1098 * Create a chain of fragments which fit the given mtu. m_frag points to the 1099 * mbuf to be fragmented; on return it points to the chain with the fragments. 1100 * Return 0 if no error. If error, m_frag may contain a partially built 1101 * chain of fragments that should be freed by the caller. 1102 * 1103 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1104 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1105 */ 1106 int 1107 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1108 u_long if_hwassist_flags, int sw_csum) 1109 { 1110 int error = 0; 1111 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1112 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1113 int off; 1114 struct mbuf *m0 = *m_frag; /* the original packet */ 1115 int firstlen; 1116 struct mbuf **mnext; 1117 int nfrags; 1118 1119 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1120 ipstat.ips_cantfrag++; 1121 return EMSGSIZE; 1122 } 1123 1124 /* 1125 * Must be able to put at least 8 bytes per fragment. 1126 */ 1127 if (len < 8) 1128 return EMSGSIZE; 1129 1130 /* 1131 * If the interface will not calculate checksums on 1132 * fragmented packets, then do it here. 1133 */ 1134 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && 1135 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { 1136 in_delayed_cksum(m0); 1137 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1138 } 1139 1140 if (len > PAGE_SIZE) { 1141 /* 1142 * Fragment large datagrams such that each segment 1143 * contains a multiple of PAGE_SIZE amount of data, 1144 * plus headers. This enables a receiver to perform 1145 * page-flipping zero-copy optimizations. 1146 * 1147 * XXX When does this help given that sender and receiver 1148 * could have different page sizes, and also mtu could 1149 * be less than the receiver's page size ? 1150 */ 1151 int newlen; 1152 struct mbuf *m; 1153 1154 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1155 off += m->m_len; 1156 1157 /* 1158 * firstlen (off - hlen) must be aligned on an 1159 * 8-byte boundary 1160 */ 1161 if (off < hlen) 1162 goto smart_frag_failure; 1163 off = ((off - hlen) & ~7) + hlen; 1164 newlen = (~PAGE_MASK) & mtu; 1165 if ((newlen + sizeof (struct ip)) > mtu) { 1166 /* we failed, go back the default */ 1167 smart_frag_failure: 1168 newlen = len; 1169 off = hlen + len; 1170 } 1171 len = newlen; 1172 1173 } else { 1174 off = hlen + len; 1175 } 1176 1177 firstlen = off - hlen; 1178 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1179 1180 /* 1181 * Loop through length of segment after first fragment, 1182 * make new header and copy data of each part and link onto chain. 1183 * Here, m0 is the original packet, m is the fragment being created. 1184 * The fragments are linked off the m_nextpkt of the original 1185 * packet, which after processing serves as the first fragment. 1186 */ 1187 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1188 struct ip *mhip; /* ip header on the fragment */ 1189 struct mbuf *m; 1190 int mhlen = sizeof (struct ip); 1191 1192 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1193 if (m == 0) { 1194 error = ENOBUFS; 1195 ipstat.ips_odropped++; 1196 goto done; 1197 } 1198 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1199 /* 1200 * In the first mbuf, leave room for the link header, then 1201 * copy the original IP header including options. The payload 1202 * goes into an additional mbuf chain returned by m_copy(). 1203 */ 1204 m->m_data += max_linkhdr; 1205 mhip = mtod(m, struct ip *); 1206 *mhip = *ip; 1207 if (hlen > sizeof (struct ip)) { 1208 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1209 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1210 } 1211 m->m_len = mhlen; 1212 /* XXX do we need to add ip->ip_off below ? */ 1213 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1214 if (off + len >= ip->ip_len) { /* last fragment */ 1215 len = ip->ip_len - off; 1216 m->m_flags |= M_LASTFRAG; 1217 } else 1218 mhip->ip_off |= IP_MF; 1219 mhip->ip_len = htons((u_short)(len + mhlen)); 1220 m->m_next = m_copy(m0, off, len); 1221 if (m->m_next == 0) { /* copy failed */ 1222 m_free(m); 1223 error = ENOBUFS; /* ??? */ 1224 ipstat.ips_odropped++; 1225 goto done; 1226 } 1227 m->m_pkthdr.len = mhlen + len; 1228 m->m_pkthdr.rcvif = (struct ifnet *)0; 1229 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1230 mhip->ip_off = htons(mhip->ip_off); 1231 mhip->ip_sum = 0; 1232 if (sw_csum & CSUM_DELAY_IP) 1233 mhip->ip_sum = in_cksum(m, mhlen); 1234 *mnext = m; 1235 mnext = &m->m_nextpkt; 1236 } 1237 ipstat.ips_ofragments += nfrags; 1238 1239 /* set first marker for fragment chain */ 1240 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1241 m0->m_pkthdr.csum_data = nfrags; 1242 1243 /* 1244 * Update first fragment by trimming what's been copied out 1245 * and updating header. 1246 */ 1247 m_adj(m0, hlen + firstlen - ip->ip_len); 1248 m0->m_pkthdr.len = hlen + firstlen; 1249 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1250 ip->ip_off |= IP_MF; 1251 ip->ip_off = htons(ip->ip_off); 1252 ip->ip_sum = 0; 1253 if (sw_csum & CSUM_DELAY_IP) 1254 ip->ip_sum = in_cksum(m0, hlen); 1255 1256 done: 1257 *m_frag = m0; 1258 return error; 1259 } 1260 1261 void 1262 in_delayed_cksum(struct mbuf *m) 1263 { 1264 struct ip *ip; 1265 u_short csum, offset; 1266 1267 ip = mtod(m, struct ip *); 1268 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1269 csum = in_cksum_skip(m, ip->ip_len, offset); 1270 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1271 csum = 0xffff; 1272 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1273 1274 if (offset + sizeof(u_short) > m->m_len) { 1275 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1276 m->m_len, offset, ip->ip_p); 1277 /* 1278 * XXX 1279 * this shouldn't happen, but if it does, the 1280 * correct behavior may be to insert the checksum 1281 * in the existing chain instead of rearranging it. 1282 */ 1283 m = m_pullup(m, offset + sizeof(u_short)); 1284 } 1285 *(u_short *)(m->m_data + offset) = csum; 1286 } 1287 1288 /* 1289 * Insert IP options into preformed packet. 1290 * Adjust IP destination as required for IP source routing, 1291 * as indicated by a non-zero in_addr at the start of the options. 1292 * 1293 * XXX This routine assumes that the packet has no options in place. 1294 */ 1295 static struct mbuf * 1296 ip_insertoptions(m, opt, phlen) 1297 struct mbuf *m; 1298 struct mbuf *opt; 1299 int *phlen; 1300 { 1301 struct ipoption *p = mtod(opt, struct ipoption *); 1302 struct mbuf *n; 1303 struct ip *ip = mtod(m, struct ip *); 1304 unsigned optlen; 1305 1306 optlen = opt->m_len - sizeof(p->ipopt_dst); 1307 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1308 *phlen = 0; 1309 return (m); /* XXX should fail */ 1310 } 1311 if (p->ipopt_dst.s_addr) 1312 ip->ip_dst = p->ipopt_dst; 1313 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1314 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1315 if (n == 0) { 1316 *phlen = 0; 1317 return (m); 1318 } 1319 n->m_pkthdr.rcvif = (struct ifnet *)0; 1320 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1321 m->m_len -= sizeof(struct ip); 1322 m->m_data += sizeof(struct ip); 1323 n->m_next = m; 1324 m = n; 1325 m->m_len = optlen + sizeof(struct ip); 1326 m->m_data += max_linkhdr; 1327 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1328 } else { 1329 m->m_data -= optlen; 1330 m->m_len += optlen; 1331 m->m_pkthdr.len += optlen; 1332 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1333 } 1334 ip = mtod(m, struct ip *); 1335 bcopy(p->ipopt_list, ip + 1, optlen); 1336 *phlen = sizeof(struct ip) + optlen; 1337 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1338 ip->ip_len += optlen; 1339 return (m); 1340 } 1341 1342 /* 1343 * Copy options from ip to jp, 1344 * omitting those not copied during fragmentation. 1345 */ 1346 int 1347 ip_optcopy(ip, jp) 1348 struct ip *ip, *jp; 1349 { 1350 u_char *cp, *dp; 1351 int opt, optlen, cnt; 1352 1353 cp = (u_char *)(ip + 1); 1354 dp = (u_char *)(jp + 1); 1355 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 1356 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1357 opt = cp[0]; 1358 if (opt == IPOPT_EOL) 1359 break; 1360 if (opt == IPOPT_NOP) { 1361 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1362 *dp++ = IPOPT_NOP; 1363 optlen = 1; 1364 continue; 1365 } 1366 1367 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1368 ("ip_optcopy: malformed ipv4 option")); 1369 optlen = cp[IPOPT_OLEN]; 1370 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1371 ("ip_optcopy: malformed ipv4 option")); 1372 1373 /* bogus lengths should have been caught by ip_dooptions */ 1374 if (optlen > cnt) 1375 optlen = cnt; 1376 if (IPOPT_COPIED(opt)) { 1377 bcopy(cp, dp, optlen); 1378 dp += optlen; 1379 } 1380 } 1381 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1382 *dp++ = IPOPT_EOL; 1383 return (optlen); 1384 } 1385 1386 /* 1387 * IP socket option processing. 1388 */ 1389 int 1390 ip_ctloutput(so, sopt) 1391 struct socket *so; 1392 struct sockopt *sopt; 1393 { 1394 struct inpcb *inp = sotoinpcb(so); 1395 int error, optval; 1396 1397 error = optval = 0; 1398 if (sopt->sopt_level != IPPROTO_IP) { 1399 return (EINVAL); 1400 } 1401 1402 switch (sopt->sopt_dir) { 1403 case SOPT_SET: 1404 switch (sopt->sopt_name) { 1405 case IP_OPTIONS: 1406 #ifdef notyet 1407 case IP_RETOPTS: 1408 #endif 1409 { 1410 struct mbuf *m; 1411 if (sopt->sopt_valsize > MLEN) { 1412 error = EMSGSIZE; 1413 break; 1414 } 1415 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1416 if (m == 0) { 1417 error = ENOBUFS; 1418 break; 1419 } 1420 m->m_len = sopt->sopt_valsize; 1421 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1422 m->m_len); 1423 1424 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1425 m)); 1426 } 1427 1428 case IP_TOS: 1429 case IP_TTL: 1430 case IP_RECVOPTS: 1431 case IP_RECVRETOPTS: 1432 case IP_RECVDSTADDR: 1433 case IP_RECVIF: 1434 case IP_FAITH: 1435 error = sooptcopyin(sopt, &optval, sizeof optval, 1436 sizeof optval); 1437 if (error) 1438 break; 1439 1440 switch (sopt->sopt_name) { 1441 case IP_TOS: 1442 inp->inp_ip_tos = optval; 1443 break; 1444 1445 case IP_TTL: 1446 inp->inp_ip_ttl = optval; 1447 break; 1448 #define OPTSET(bit) \ 1449 if (optval) \ 1450 inp->inp_flags |= bit; \ 1451 else \ 1452 inp->inp_flags &= ~bit; 1453 1454 case IP_RECVOPTS: 1455 OPTSET(INP_RECVOPTS); 1456 break; 1457 1458 case IP_RECVRETOPTS: 1459 OPTSET(INP_RECVRETOPTS); 1460 break; 1461 1462 case IP_RECVDSTADDR: 1463 OPTSET(INP_RECVDSTADDR); 1464 break; 1465 1466 case IP_RECVIF: 1467 OPTSET(INP_RECVIF); 1468 break; 1469 1470 case IP_FAITH: 1471 OPTSET(INP_FAITH); 1472 break; 1473 } 1474 break; 1475 #undef OPTSET 1476 1477 case IP_MULTICAST_IF: 1478 case IP_MULTICAST_VIF: 1479 case IP_MULTICAST_TTL: 1480 case IP_MULTICAST_LOOP: 1481 case IP_ADD_MEMBERSHIP: 1482 case IP_DROP_MEMBERSHIP: 1483 error = ip_setmoptions(sopt, &inp->inp_moptions); 1484 break; 1485 1486 case IP_PORTRANGE: 1487 error = sooptcopyin(sopt, &optval, sizeof optval, 1488 sizeof optval); 1489 if (error) 1490 break; 1491 1492 switch (optval) { 1493 case IP_PORTRANGE_DEFAULT: 1494 inp->inp_flags &= ~(INP_LOWPORT); 1495 inp->inp_flags &= ~(INP_HIGHPORT); 1496 break; 1497 1498 case IP_PORTRANGE_HIGH: 1499 inp->inp_flags &= ~(INP_LOWPORT); 1500 inp->inp_flags |= INP_HIGHPORT; 1501 break; 1502 1503 case IP_PORTRANGE_LOW: 1504 inp->inp_flags &= ~(INP_HIGHPORT); 1505 inp->inp_flags |= INP_LOWPORT; 1506 break; 1507 1508 default: 1509 error = EINVAL; 1510 break; 1511 } 1512 break; 1513 1514 #if defined(IPSEC) || defined(FAST_IPSEC) 1515 case IP_IPSEC_POLICY: 1516 { 1517 caddr_t req; 1518 size_t len = 0; 1519 int priv; 1520 struct mbuf *m; 1521 int optname; 1522 1523 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1524 break; 1525 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1526 break; 1527 priv = (sopt->sopt_td != NULL && 1528 suser(sopt->sopt_td) != 0) ? 0 : 1; 1529 req = mtod(m, caddr_t); 1530 len = m->m_len; 1531 optname = sopt->sopt_name; 1532 error = ipsec4_set_policy(inp, optname, req, len, priv); 1533 m_freem(m); 1534 break; 1535 } 1536 #endif /*IPSEC*/ 1537 1538 default: 1539 error = ENOPROTOOPT; 1540 break; 1541 } 1542 break; 1543 1544 case SOPT_GET: 1545 switch (sopt->sopt_name) { 1546 case IP_OPTIONS: 1547 case IP_RETOPTS: 1548 if (inp->inp_options) 1549 error = sooptcopyout(sopt, 1550 mtod(inp->inp_options, 1551 char *), 1552 inp->inp_options->m_len); 1553 else 1554 sopt->sopt_valsize = 0; 1555 break; 1556 1557 case IP_TOS: 1558 case IP_TTL: 1559 case IP_RECVOPTS: 1560 case IP_RECVRETOPTS: 1561 case IP_RECVDSTADDR: 1562 case IP_RECVIF: 1563 case IP_PORTRANGE: 1564 case IP_FAITH: 1565 switch (sopt->sopt_name) { 1566 1567 case IP_TOS: 1568 optval = inp->inp_ip_tos; 1569 break; 1570 1571 case IP_TTL: 1572 optval = inp->inp_ip_ttl; 1573 break; 1574 1575 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1576 1577 case IP_RECVOPTS: 1578 optval = OPTBIT(INP_RECVOPTS); 1579 break; 1580 1581 case IP_RECVRETOPTS: 1582 optval = OPTBIT(INP_RECVRETOPTS); 1583 break; 1584 1585 case IP_RECVDSTADDR: 1586 optval = OPTBIT(INP_RECVDSTADDR); 1587 break; 1588 1589 case IP_RECVIF: 1590 optval = OPTBIT(INP_RECVIF); 1591 break; 1592 1593 case IP_PORTRANGE: 1594 if (inp->inp_flags & INP_HIGHPORT) 1595 optval = IP_PORTRANGE_HIGH; 1596 else if (inp->inp_flags & INP_LOWPORT) 1597 optval = IP_PORTRANGE_LOW; 1598 else 1599 optval = 0; 1600 break; 1601 1602 case IP_FAITH: 1603 optval = OPTBIT(INP_FAITH); 1604 break; 1605 } 1606 error = sooptcopyout(sopt, &optval, sizeof optval); 1607 break; 1608 1609 case IP_MULTICAST_IF: 1610 case IP_MULTICAST_VIF: 1611 case IP_MULTICAST_TTL: 1612 case IP_MULTICAST_LOOP: 1613 case IP_ADD_MEMBERSHIP: 1614 case IP_DROP_MEMBERSHIP: 1615 error = ip_getmoptions(sopt, inp->inp_moptions); 1616 break; 1617 1618 #if defined(IPSEC) || defined(FAST_IPSEC) 1619 case IP_IPSEC_POLICY: 1620 { 1621 struct mbuf *m = NULL; 1622 caddr_t req = NULL; 1623 size_t len = 0; 1624 1625 if (m != 0) { 1626 req = mtod(m, caddr_t); 1627 len = m->m_len; 1628 } 1629 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1630 if (error == 0) 1631 error = soopt_mcopyout(sopt, m); /* XXX */ 1632 if (error == 0) 1633 m_freem(m); 1634 break; 1635 } 1636 #endif /*IPSEC*/ 1637 1638 default: 1639 error = ENOPROTOOPT; 1640 break; 1641 } 1642 break; 1643 } 1644 return (error); 1645 } 1646 1647 /* 1648 * Set up IP options in pcb for insertion in output packets. 1649 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1650 * with destination address if source routed. 1651 */ 1652 static int 1653 ip_pcbopts(optname, pcbopt, m) 1654 int optname; 1655 struct mbuf **pcbopt; 1656 struct mbuf *m; 1657 { 1658 int cnt, optlen; 1659 u_char *cp; 1660 u_char opt; 1661 1662 /* turn off any old options */ 1663 if (*pcbopt) 1664 (void)m_free(*pcbopt); 1665 *pcbopt = 0; 1666 if (m == (struct mbuf *)0 || m->m_len == 0) { 1667 /* 1668 * Only turning off any previous options. 1669 */ 1670 if (m) 1671 (void)m_free(m); 1672 return (0); 1673 } 1674 1675 if (m->m_len % sizeof(int32_t)) 1676 goto bad; 1677 /* 1678 * IP first-hop destination address will be stored before 1679 * actual options; move other options back 1680 * and clear it when none present. 1681 */ 1682 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1683 goto bad; 1684 cnt = m->m_len; 1685 m->m_len += sizeof(struct in_addr); 1686 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1687 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 1688 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1689 1690 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1691 opt = cp[IPOPT_OPTVAL]; 1692 if (opt == IPOPT_EOL) 1693 break; 1694 if (opt == IPOPT_NOP) 1695 optlen = 1; 1696 else { 1697 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1698 goto bad; 1699 optlen = cp[IPOPT_OLEN]; 1700 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1701 goto bad; 1702 } 1703 switch (opt) { 1704 1705 default: 1706 break; 1707 1708 case IPOPT_LSRR: 1709 case IPOPT_SSRR: 1710 /* 1711 * user process specifies route as: 1712 * ->A->B->C->D 1713 * D must be our final destination (but we can't 1714 * check that since we may not have connected yet). 1715 * A is first hop destination, which doesn't appear in 1716 * actual IP option, but is stored before the options. 1717 */ 1718 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1719 goto bad; 1720 m->m_len -= sizeof(struct in_addr); 1721 cnt -= sizeof(struct in_addr); 1722 optlen -= sizeof(struct in_addr); 1723 cp[IPOPT_OLEN] = optlen; 1724 /* 1725 * Move first hop before start of options. 1726 */ 1727 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1728 sizeof(struct in_addr)); 1729 /* 1730 * Then copy rest of options back 1731 * to close up the deleted entry. 1732 */ 1733 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1734 sizeof(struct in_addr)), 1735 &cp[IPOPT_OFFSET+1], 1736 (unsigned)cnt - (IPOPT_MINOFF - 1)); 1737 break; 1738 } 1739 } 1740 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1741 goto bad; 1742 *pcbopt = m; 1743 return (0); 1744 1745 bad: 1746 (void)m_free(m); 1747 return (EINVAL); 1748 } 1749 1750 /* 1751 * XXX 1752 * The whole multicast option thing needs to be re-thought. 1753 * Several of these options are equally applicable to non-multicast 1754 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1755 * standard option (IP_TTL). 1756 */ 1757 1758 /* 1759 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1760 */ 1761 static struct ifnet * 1762 ip_multicast_if(a, ifindexp) 1763 struct in_addr *a; 1764 int *ifindexp; 1765 { 1766 int ifindex; 1767 struct ifnet *ifp; 1768 1769 if (ifindexp) 1770 *ifindexp = 0; 1771 if (ntohl(a->s_addr) >> 24 == 0) { 1772 ifindex = ntohl(a->s_addr) & 0xffffff; 1773 if (ifindex < 0 || if_index < ifindex) 1774 return NULL; 1775 ifp = ifindex2ifnet[ifindex]; 1776 if (ifindexp) 1777 *ifindexp = ifindex; 1778 } else { 1779 INADDR_TO_IFP(*a, ifp); 1780 } 1781 return ifp; 1782 } 1783 1784 /* 1785 * Set the IP multicast options in response to user setsockopt(). 1786 */ 1787 static int 1788 ip_setmoptions(sopt, imop) 1789 struct sockopt *sopt; 1790 struct ip_moptions **imop; 1791 { 1792 int error = 0; 1793 int i; 1794 struct in_addr addr; 1795 struct ip_mreq mreq; 1796 struct ifnet *ifp; 1797 struct ip_moptions *imo = *imop; 1798 struct route ro; 1799 struct sockaddr_in *dst; 1800 int ifindex; 1801 int s; 1802 1803 if (imo == NULL) { 1804 /* 1805 * No multicast option buffer attached to the pcb; 1806 * allocate one and initialize to default values. 1807 */ 1808 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1809 M_WAITOK); 1810 1811 if (imo == NULL) 1812 return (ENOBUFS); 1813 *imop = imo; 1814 imo->imo_multicast_ifp = NULL; 1815 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1816 imo->imo_multicast_vif = -1; 1817 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1818 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1819 imo->imo_num_memberships = 0; 1820 } 1821 1822 switch (sopt->sopt_name) { 1823 /* store an index number for the vif you wanna use in the send */ 1824 case IP_MULTICAST_VIF: 1825 if (legal_vif_num == 0) { 1826 error = EOPNOTSUPP; 1827 break; 1828 } 1829 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1830 if (error) 1831 break; 1832 if (!legal_vif_num(i) && (i != -1)) { 1833 error = EINVAL; 1834 break; 1835 } 1836 imo->imo_multicast_vif = i; 1837 break; 1838 1839 case IP_MULTICAST_IF: 1840 /* 1841 * Select the interface for outgoing multicast packets. 1842 */ 1843 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1844 if (error) 1845 break; 1846 /* 1847 * INADDR_ANY is used to remove a previous selection. 1848 * When no interface is selected, a default one is 1849 * chosen every time a multicast packet is sent. 1850 */ 1851 if (addr.s_addr == INADDR_ANY) { 1852 imo->imo_multicast_ifp = NULL; 1853 break; 1854 } 1855 /* 1856 * The selected interface is identified by its local 1857 * IP address. Find the interface and confirm that 1858 * it supports multicasting. 1859 */ 1860 s = splimp(); 1861 ifp = ip_multicast_if(&addr, &ifindex); 1862 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1863 splx(s); 1864 error = EADDRNOTAVAIL; 1865 break; 1866 } 1867 imo->imo_multicast_ifp = ifp; 1868 if (ifindex) 1869 imo->imo_multicast_addr = addr; 1870 else 1871 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1872 splx(s); 1873 break; 1874 1875 case IP_MULTICAST_TTL: 1876 /* 1877 * Set the IP time-to-live for outgoing multicast packets. 1878 * The original multicast API required a char argument, 1879 * which is inconsistent with the rest of the socket API. 1880 * We allow either a char or an int. 1881 */ 1882 if (sopt->sopt_valsize == 1) { 1883 u_char ttl; 1884 error = sooptcopyin(sopt, &ttl, 1, 1); 1885 if (error) 1886 break; 1887 imo->imo_multicast_ttl = ttl; 1888 } else { 1889 u_int ttl; 1890 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1891 sizeof ttl); 1892 if (error) 1893 break; 1894 if (ttl > 255) 1895 error = EINVAL; 1896 else 1897 imo->imo_multicast_ttl = ttl; 1898 } 1899 break; 1900 1901 case IP_MULTICAST_LOOP: 1902 /* 1903 * Set the loopback flag for outgoing multicast packets. 1904 * Must be zero or one. The original multicast API required a 1905 * char argument, which is inconsistent with the rest 1906 * of the socket API. We allow either a char or an int. 1907 */ 1908 if (sopt->sopt_valsize == 1) { 1909 u_char loop; 1910 error = sooptcopyin(sopt, &loop, 1, 1); 1911 if (error) 1912 break; 1913 imo->imo_multicast_loop = !!loop; 1914 } else { 1915 u_int loop; 1916 error = sooptcopyin(sopt, &loop, sizeof loop, 1917 sizeof loop); 1918 if (error) 1919 break; 1920 imo->imo_multicast_loop = !!loop; 1921 } 1922 break; 1923 1924 case IP_ADD_MEMBERSHIP: 1925 /* 1926 * Add a multicast group membership. 1927 * Group must be a valid IP multicast address. 1928 */ 1929 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1930 if (error) 1931 break; 1932 1933 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1934 error = EINVAL; 1935 break; 1936 } 1937 s = splimp(); 1938 /* 1939 * If no interface address was provided, use the interface of 1940 * the route to the given multicast address. 1941 */ 1942 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1943 bzero((caddr_t)&ro, sizeof(ro)); 1944 dst = (struct sockaddr_in *)&ro.ro_dst; 1945 dst->sin_len = sizeof(*dst); 1946 dst->sin_family = AF_INET; 1947 dst->sin_addr = mreq.imr_multiaddr; 1948 rtalloc(&ro); 1949 if (ro.ro_rt == NULL) { 1950 error = EADDRNOTAVAIL; 1951 splx(s); 1952 break; 1953 } 1954 ifp = ro.ro_rt->rt_ifp; 1955 rtfree(ro.ro_rt); 1956 } 1957 else { 1958 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1959 } 1960 1961 /* 1962 * See if we found an interface, and confirm that it 1963 * supports multicast. 1964 */ 1965 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1966 error = EADDRNOTAVAIL; 1967 splx(s); 1968 break; 1969 } 1970 /* 1971 * See if the membership already exists or if all the 1972 * membership slots are full. 1973 */ 1974 for (i = 0; i < imo->imo_num_memberships; ++i) { 1975 if (imo->imo_membership[i]->inm_ifp == ifp && 1976 imo->imo_membership[i]->inm_addr.s_addr 1977 == mreq.imr_multiaddr.s_addr) 1978 break; 1979 } 1980 if (i < imo->imo_num_memberships) { 1981 error = EADDRINUSE; 1982 splx(s); 1983 break; 1984 } 1985 if (i == IP_MAX_MEMBERSHIPS) { 1986 error = ETOOMANYREFS; 1987 splx(s); 1988 break; 1989 } 1990 /* 1991 * Everything looks good; add a new record to the multicast 1992 * address list for the given interface. 1993 */ 1994 if ((imo->imo_membership[i] = 1995 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1996 error = ENOBUFS; 1997 splx(s); 1998 break; 1999 } 2000 ++imo->imo_num_memberships; 2001 splx(s); 2002 break; 2003 2004 case IP_DROP_MEMBERSHIP: 2005 /* 2006 * Drop a multicast group membership. 2007 * Group must be a valid IP multicast address. 2008 */ 2009 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2010 if (error) 2011 break; 2012 2013 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2014 error = EINVAL; 2015 break; 2016 } 2017 2018 s = splimp(); 2019 /* 2020 * If an interface address was specified, get a pointer 2021 * to its ifnet structure. 2022 */ 2023 if (mreq.imr_interface.s_addr == INADDR_ANY) 2024 ifp = NULL; 2025 else { 2026 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2027 if (ifp == NULL) { 2028 error = EADDRNOTAVAIL; 2029 splx(s); 2030 break; 2031 } 2032 } 2033 /* 2034 * Find the membership in the membership array. 2035 */ 2036 for (i = 0; i < imo->imo_num_memberships; ++i) { 2037 if ((ifp == NULL || 2038 imo->imo_membership[i]->inm_ifp == ifp) && 2039 imo->imo_membership[i]->inm_addr.s_addr == 2040 mreq.imr_multiaddr.s_addr) 2041 break; 2042 } 2043 if (i == imo->imo_num_memberships) { 2044 error = EADDRNOTAVAIL; 2045 splx(s); 2046 break; 2047 } 2048 /* 2049 * Give up the multicast address record to which the 2050 * membership points. 2051 */ 2052 in_delmulti(imo->imo_membership[i]); 2053 /* 2054 * Remove the gap in the membership array. 2055 */ 2056 for (++i; i < imo->imo_num_memberships; ++i) 2057 imo->imo_membership[i-1] = imo->imo_membership[i]; 2058 --imo->imo_num_memberships; 2059 splx(s); 2060 break; 2061 2062 default: 2063 error = EOPNOTSUPP; 2064 break; 2065 } 2066 2067 /* 2068 * If all options have default values, no need to keep the mbuf. 2069 */ 2070 if (imo->imo_multicast_ifp == NULL && 2071 imo->imo_multicast_vif == -1 && 2072 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2073 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2074 imo->imo_num_memberships == 0) { 2075 free(*imop, M_IPMOPTS); 2076 *imop = NULL; 2077 } 2078 2079 return (error); 2080 } 2081 2082 /* 2083 * Return the IP multicast options in response to user getsockopt(). 2084 */ 2085 static int 2086 ip_getmoptions(sopt, imo) 2087 struct sockopt *sopt; 2088 struct ip_moptions *imo; 2089 { 2090 struct in_addr addr; 2091 struct in_ifaddr *ia; 2092 int error, optval; 2093 u_char coptval; 2094 2095 error = 0; 2096 switch (sopt->sopt_name) { 2097 case IP_MULTICAST_VIF: 2098 if (imo != NULL) 2099 optval = imo->imo_multicast_vif; 2100 else 2101 optval = -1; 2102 error = sooptcopyout(sopt, &optval, sizeof optval); 2103 break; 2104 2105 case IP_MULTICAST_IF: 2106 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2107 addr.s_addr = INADDR_ANY; 2108 else if (imo->imo_multicast_addr.s_addr) { 2109 /* return the value user has set */ 2110 addr = imo->imo_multicast_addr; 2111 } else { 2112 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2113 addr.s_addr = (ia == NULL) ? INADDR_ANY 2114 : IA_SIN(ia)->sin_addr.s_addr; 2115 } 2116 error = sooptcopyout(sopt, &addr, sizeof addr); 2117 break; 2118 2119 case IP_MULTICAST_TTL: 2120 if (imo == 0) 2121 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2122 else 2123 optval = coptval = imo->imo_multicast_ttl; 2124 if (sopt->sopt_valsize == 1) 2125 error = sooptcopyout(sopt, &coptval, 1); 2126 else 2127 error = sooptcopyout(sopt, &optval, sizeof optval); 2128 break; 2129 2130 case IP_MULTICAST_LOOP: 2131 if (imo == 0) 2132 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2133 else 2134 optval = coptval = imo->imo_multicast_loop; 2135 if (sopt->sopt_valsize == 1) 2136 error = sooptcopyout(sopt, &coptval, 1); 2137 else 2138 error = sooptcopyout(sopt, &optval, sizeof optval); 2139 break; 2140 2141 default: 2142 error = ENOPROTOOPT; 2143 break; 2144 } 2145 return (error); 2146 } 2147 2148 /* 2149 * Discard the IP multicast options. 2150 */ 2151 void 2152 ip_freemoptions(imo) 2153 struct ip_moptions *imo; 2154 { 2155 int i; 2156 2157 if (imo != NULL) { 2158 for (i = 0; i < imo->imo_num_memberships; ++i) 2159 in_delmulti(imo->imo_membership[i]); 2160 free(imo, M_IPMOPTS); 2161 } 2162 } 2163 2164 /* 2165 * Routine called from ip_output() to loop back a copy of an IP multicast 2166 * packet to the input queue of a specified interface. Note that this 2167 * calls the output routine of the loopback "driver", but with an interface 2168 * pointer that might NOT be a loopback interface -- evil, but easier than 2169 * replicating that code here. 2170 */ 2171 static void 2172 ip_mloopback(ifp, m, dst, hlen) 2173 struct ifnet *ifp; 2174 struct mbuf *m; 2175 struct sockaddr_in *dst; 2176 int hlen; 2177 { 2178 struct ip *ip; 2179 struct mbuf *copym; 2180 2181 copym = m_copy(m, 0, M_COPYALL); 2182 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2183 copym = m_pullup(copym, hlen); 2184 if (copym != NULL) { 2185 /* 2186 * if the checksum hasn't been computed, mark it as valid 2187 */ 2188 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2189 in_delayed_cksum(copym); 2190 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2191 copym->m_pkthdr.csum_flags |= 2192 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2193 copym->m_pkthdr.csum_data = 0xffff; 2194 } 2195 /* 2196 * We don't bother to fragment if the IP length is greater 2197 * than the interface's MTU. Can this possibly matter? 2198 */ 2199 ip = mtod(copym, struct ip *); 2200 ip->ip_len = htons(ip->ip_len); 2201 ip->ip_off = htons(ip->ip_off); 2202 ip->ip_sum = 0; 2203 if (ip->ip_vhl == IP_VHL_BORING) { 2204 ip->ip_sum = in_cksum_hdr(ip); 2205 } else { 2206 ip->ip_sum = in_cksum(copym, hlen); 2207 } 2208 /* 2209 * NB: 2210 * It's not clear whether there are any lingering 2211 * reentrancy problems in other areas which might 2212 * be exposed by using ip_input directly (in 2213 * particular, everything which modifies the packet 2214 * in-place). Yet another option is using the 2215 * protosw directly to deliver the looped back 2216 * packet. For the moment, we'll err on the side 2217 * of safety by using if_simloop(). 2218 */ 2219 #if 1 /* XXX */ 2220 if (dst->sin_family != AF_INET) { 2221 printf("ip_mloopback: bad address family %d\n", 2222 dst->sin_family); 2223 dst->sin_family = AF_INET; 2224 } 2225 #endif 2226 2227 #ifdef notdef 2228 copym->m_pkthdr.rcvif = ifp; 2229 ip_input(copym); 2230 #else 2231 if_simloop(ifp, copym, dst->sin_family, 0); 2232 #endif 2233 } 2234 } 2235