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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 34 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $ 35 * $DragonFly: src/sys/netinet/ip_output.c,v 1.9 2003/12/02 08:00:22 asmodai Exp $ 36 */ 37 38 #define _IP_VHL 39 40 #include "opt_ipfw.h" 41 #include "opt_ipdn.h" 42 #include "opt_ipdivert.h" 43 #include "opt_ipfilter.h" 44 #include "opt_ipsec.h" 45 #include "opt_pfil_hooks.h" 46 #include "opt_random_ip_id.h" 47 #include "opt_mbuf_stress_test.h" 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/kernel.h> 52 #include <sys/malloc.h> 53 #include <sys/mbuf.h> 54 #include <sys/protosw.h> 55 #include <sys/socket.h> 56 #include <sys/socketvar.h> 57 #include <sys/proc.h> 58 #include <sys/sysctl.h> 59 60 #include <net/if.h> 61 #ifdef PFIL_HOOKS 62 #include <net/pfil.h> 63 #endif 64 #include <net/route.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/ip.h> 69 #include <netinet/in_pcb.h> 70 #include <netinet/in_var.h> 71 #include <netinet/ip_var.h> 72 73 #include <machine/in_cksum.h> 74 75 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 76 77 #ifdef IPSEC 78 #include <netinet6/ipsec.h> 79 #include <netproto/key/key.h> 80 #ifdef IPSEC_DEBUG 81 #include <netproto/key/key_debug.h> 82 #else 83 #define KEYDEBUG(lev,arg) 84 #endif 85 #endif /*IPSEC*/ 86 87 #ifdef FAST_IPSEC 88 #include <netipsec/ipsec.h> 89 #include <netipsec/xform.h> 90 #include <netipsec/key.h> 91 #endif /*FAST_IPSEC*/ 92 93 #include <net/ipfw/ip_fw.h> 94 #include <net/dummynet/ip_dummynet.h> 95 96 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ 97 x, (ntohl(a.s_addr)>>24)&0xFF,\ 98 (ntohl(a.s_addr)>>16)&0xFF,\ 99 (ntohl(a.s_addr)>>8)&0xFF,\ 100 (ntohl(a.s_addr))&0xFF, y); 101 102 u_short ip_id; 103 104 #ifdef MBUF_STRESS_TEST 105 int mbuf_frag_size = 0; 106 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 107 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 108 #endif 109 110 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 111 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 112 static void ip_mloopback 113 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 114 static int ip_getmoptions 115 (struct sockopt *, struct ip_moptions *); 116 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 117 static int ip_setmoptions 118 (struct sockopt *, struct ip_moptions **); 119 120 int ip_optcopy(struct ip *, struct ip *); 121 extern int (*fr_checkp) (struct ip *, int, struct ifnet *, int, struct mbuf **); 122 123 124 extern struct protosw inetsw[]; 125 126 /* 127 * IP output. The packet in mbuf chain m contains a skeletal IP 128 * header (with len, off, ttl, proto, tos, src, dst). 129 * The mbuf chain containing the packet will be freed. 130 * The mbuf opt, if present, will not be freed. 131 */ 132 int 133 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 134 int flags, struct ip_moptions *imo, struct inpcb *inp) 135 { 136 struct ip *ip; 137 struct ifnet *ifp = NULL; /* keep compiler happy */ 138 struct mbuf *m; 139 int hlen = sizeof (struct ip); 140 int len, off, error = 0; 141 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 142 struct in_ifaddr *ia = NULL; 143 int isbroadcast, sw_csum; 144 struct in_addr pkt_dst; 145 #ifdef IPSEC 146 struct route iproute; 147 struct secpolicy *sp = NULL; 148 struct socket *so = inp ? inp->inp_socket : NULL; 149 #endif 150 #ifdef FAST_IPSEC 151 struct route iproute; 152 struct m_tag *mtag; 153 struct secpolicy *sp = NULL; 154 struct tdb_ident *tdbi; 155 int s; 156 #endif /* FAST_IPSEC */ 157 struct ip_fw_args args; 158 int src_was_INADDR_ANY = 0; /* as the name says... */ 159 160 args.eh = NULL; 161 args.rule = NULL; 162 args.next_hop = NULL; 163 args.divert_rule = 0; /* divert cookie */ 164 165 /* Grab info from MT_TAG mbufs prepended to the chain. */ 166 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) { 167 switch(m0->_m_tag_id) { 168 default: 169 printf("ip_output: unrecognised MT_TAG tag %d\n", 170 m0->_m_tag_id); 171 break; 172 173 case PACKET_TAG_DUMMYNET: 174 /* 175 * the packet was already tagged, so part of the 176 * processing was already done, and we need to go down. 177 * Get parameters from the header. 178 */ 179 args.rule = ((struct dn_pkt *)m0)->rule; 180 opt = NULL ; 181 ro = & ( ((struct dn_pkt *)m0)->ro ) ; 182 imo = NULL ; 183 dst = ((struct dn_pkt *)m0)->dn_dst ; 184 ifp = ((struct dn_pkt *)m0)->ifp ; 185 flags = ((struct dn_pkt *)m0)->flags ; 186 break; 187 188 case PACKET_TAG_DIVERT: 189 args.divert_rule = (int)m0->m_data & 0xffff; 190 break; 191 192 case PACKET_TAG_IPFORWARD: 193 args.next_hop = (struct sockaddr_in *)m0->m_data; 194 break; 195 } 196 } 197 m = m0; 198 199 KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR")); 200 #ifndef FAST_IPSEC 201 KASSERT(ro != NULL, ("ip_output: no route, proto %d", 202 mtod(m, struct ip *)->ip_p)); 203 #endif 204 205 if (args.rule != NULL) { /* dummynet already saw us */ 206 ip = mtod(m, struct ip *); 207 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 208 if (ro->ro_rt) 209 ia = ifatoia(ro->ro_rt->rt_ifa); 210 goto sendit; 211 } 212 213 if (opt) { 214 len = 0; 215 m = ip_insertoptions(m, opt, &len); 216 if (len != 0) 217 hlen = len; 218 } 219 ip = mtod(m, struct ip *); 220 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 221 222 /* 223 * Fill in IP header. 224 */ 225 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 226 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 227 ip->ip_off &= IP_DF; 228 #ifdef RANDOM_IP_ID 229 ip->ip_id = ip_randomid(); 230 #else 231 ip->ip_id = htons(ip_id++); 232 #endif 233 ipstat.ips_localout++; 234 } else { 235 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 236 } 237 238 #ifdef FAST_IPSEC 239 if (ro == NULL) { 240 ro = &iproute; 241 bzero(ro, sizeof (*ro)); 242 } 243 #endif /* FAST_IPSEC */ 244 dst = (struct sockaddr_in *)&ro->ro_dst; 245 /* 246 * If there is a cached route, 247 * check that it is to the same destination 248 * and is still up. If not, free it and try again. 249 * The address family should also be checked in case of sharing the 250 * cache with IPv6. 251 */ 252 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 253 dst->sin_family != AF_INET || 254 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 255 RTFREE(ro->ro_rt); 256 ro->ro_rt = (struct rtentry *)0; 257 } 258 if (ro->ro_rt == 0) { 259 bzero(dst, sizeof(*dst)); 260 dst->sin_family = AF_INET; 261 dst->sin_len = sizeof(*dst); 262 dst->sin_addr = pkt_dst; 263 } 264 /* 265 * If routing to interface only, 266 * short circuit routing lookup. 267 */ 268 if (flags & IP_ROUTETOIF) { 269 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 270 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 271 ipstat.ips_noroute++; 272 error = ENETUNREACH; 273 goto bad; 274 } 275 ifp = ia->ia_ifp; 276 ip->ip_ttl = 1; 277 isbroadcast = in_broadcast(dst->sin_addr, ifp); 278 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 279 imo != NULL && imo->imo_multicast_ifp != NULL) { 280 /* 281 * Bypass the normal routing lookup for multicast 282 * packets if the interface is specified. 283 */ 284 ifp = imo->imo_multicast_ifp; 285 IFP_TO_IA(ifp, ia); 286 isbroadcast = 0; /* fool gcc */ 287 } else { 288 /* 289 * If this is the case, we probably don't want to allocate 290 * a protocol-cloned route since we didn't get one from the 291 * ULP. This lets TCP do its thing, while not burdening 292 * forwarding or ICMP with the overhead of cloning a route. 293 * Of course, we still want to do any cloning requested by 294 * the link layer, as this is probably required in all cases 295 * for correct operation (as it is for ARP). 296 */ 297 if (ro->ro_rt == 0) 298 rtalloc_ign(ro, RTF_PRCLONING); 299 if (ro->ro_rt == 0) { 300 ipstat.ips_noroute++; 301 error = EHOSTUNREACH; 302 goto bad; 303 } 304 ia = ifatoia(ro->ro_rt->rt_ifa); 305 ifp = ro->ro_rt->rt_ifp; 306 ro->ro_rt->rt_use++; 307 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 308 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 309 if (ro->ro_rt->rt_flags & RTF_HOST) 310 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 311 else 312 isbroadcast = in_broadcast(dst->sin_addr, ifp); 313 } 314 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 315 struct in_multi *inm; 316 317 m->m_flags |= M_MCAST; 318 /* 319 * IP destination address is multicast. Make sure "dst" 320 * still points to the address in "ro". (It may have been 321 * changed to point to a gateway address, above.) 322 */ 323 dst = (struct sockaddr_in *)&ro->ro_dst; 324 /* 325 * See if the caller provided any multicast options 326 */ 327 if (imo != NULL) { 328 ip->ip_ttl = imo->imo_multicast_ttl; 329 if (imo->imo_multicast_vif != -1) 330 ip->ip_src.s_addr = 331 ip_mcast_src ? 332 ip_mcast_src(imo->imo_multicast_vif) : 333 INADDR_ANY; 334 } else 335 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 336 /* 337 * Confirm that the outgoing interface supports multicast. 338 */ 339 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 340 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 341 ipstat.ips_noroute++; 342 error = ENETUNREACH; 343 goto bad; 344 } 345 } 346 /* 347 * If source address not specified yet, use address 348 * of outgoing interface. 349 */ 350 if (ip->ip_src.s_addr == INADDR_ANY) { 351 /* Interface may have no addresses. */ 352 if (ia != NULL) 353 ip->ip_src = IA_SIN(ia)->sin_addr; 354 } 355 356 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 357 /* 358 * XXX 359 * delayed checksums are not currently 360 * compatible with IP multicast routing 361 */ 362 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 363 in_delayed_cksum(m); 364 m->m_pkthdr.csum_flags &= 365 ~CSUM_DELAY_DATA; 366 } 367 } 368 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 369 if (inm != NULL && 370 (imo == NULL || imo->imo_multicast_loop)) { 371 /* 372 * If we belong to the destination multicast group 373 * on the outgoing interface, and the caller did not 374 * forbid loopback, loop back a copy. 375 */ 376 ip_mloopback(ifp, m, dst, hlen); 377 } 378 else { 379 /* 380 * If we are acting as a multicast router, perform 381 * multicast forwarding as if the packet had just 382 * arrived on the interface to which we are about 383 * to send. The multicast forwarding function 384 * recursively calls this function, using the 385 * IP_FORWARDING flag to prevent infinite recursion. 386 * 387 * Multicasts that are looped back by ip_mloopback(), 388 * above, will be forwarded by the ip_input() routine, 389 * if necessary. 390 */ 391 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 392 /* 393 * If rsvp daemon is not running, do not 394 * set ip_moptions. This ensures that the packet 395 * is multicast and not just sent down one link 396 * as prescribed by rsvpd. 397 */ 398 if (!rsvp_on) 399 imo = NULL; 400 if (ip_mforward && 401 ip_mforward(ip, ifp, m, imo) != 0) { 402 m_freem(m); 403 goto done; 404 } 405 } 406 } 407 408 /* 409 * Multicasts with a time-to-live of zero may be looped- 410 * back, above, but must not be transmitted on a network. 411 * Also, multicasts addressed to the loopback interface 412 * are not sent -- the above call to ip_mloopback() will 413 * loop back a copy if this host actually belongs to the 414 * destination group on the loopback interface. 415 */ 416 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 417 m_freem(m); 418 goto done; 419 } 420 421 goto sendit; 422 } 423 #ifndef notdef 424 /* 425 * If the source address is not specified yet, use the address 426 * of the outoing interface. In case, keep note we did that, so 427 * if the the firewall changes the next-hop causing the output 428 * interface to change, we can fix that. 429 */ 430 if (ip->ip_src.s_addr == INADDR_ANY) { 431 /* Interface may have no addresses. */ 432 if (ia != NULL) { 433 ip->ip_src = IA_SIN(ia)->sin_addr; 434 src_was_INADDR_ANY = 1; 435 } 436 } 437 #endif /* notdef */ 438 /* 439 * Verify that we have any chance at all of being able to queue 440 * the packet or packet fragments 441 */ 442 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 443 ifp->if_snd.ifq_maxlen) { 444 error = ENOBUFS; 445 ipstat.ips_odropped++; 446 goto bad; 447 } 448 449 /* 450 * Look for broadcast address and 451 * verify user is allowed to send 452 * such a packet. 453 */ 454 if (isbroadcast) { 455 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 456 error = EADDRNOTAVAIL; 457 goto bad; 458 } 459 if ((flags & IP_ALLOWBROADCAST) == 0) { 460 error = EACCES; 461 goto bad; 462 } 463 /* don't allow broadcast messages to be fragmented */ 464 if (ip->ip_len > ifp->if_mtu) { 465 error = EMSGSIZE; 466 goto bad; 467 } 468 m->m_flags |= M_BCAST; 469 } else { 470 m->m_flags &= ~M_BCAST; 471 } 472 473 sendit: 474 #ifdef IPSEC 475 /* get SP for this packet */ 476 if (so == NULL) 477 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 478 else 479 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 480 481 if (sp == NULL) { 482 ipsecstat.out_inval++; 483 goto bad; 484 } 485 486 error = 0; 487 488 /* check policy */ 489 switch (sp->policy) { 490 case IPSEC_POLICY_DISCARD: 491 /* 492 * This packet is just discarded. 493 */ 494 ipsecstat.out_polvio++; 495 goto bad; 496 497 case IPSEC_POLICY_BYPASS: 498 case IPSEC_POLICY_NONE: 499 /* no need to do IPsec. */ 500 goto skip_ipsec; 501 502 case IPSEC_POLICY_IPSEC: 503 if (sp->req == NULL) { 504 /* acquire a policy */ 505 error = key_spdacquire(sp); 506 goto bad; 507 } 508 break; 509 510 case IPSEC_POLICY_ENTRUST: 511 default: 512 printf("ip_output: Invalid policy found. %d\n", sp->policy); 513 } 514 { 515 struct ipsec_output_state state; 516 bzero(&state, sizeof(state)); 517 state.m = m; 518 if (flags & IP_ROUTETOIF) { 519 state.ro = &iproute; 520 bzero(&iproute, sizeof(iproute)); 521 } else 522 state.ro = ro; 523 state.dst = (struct sockaddr *)dst; 524 525 ip->ip_sum = 0; 526 527 /* 528 * XXX 529 * delayed checksums are not currently compatible with IPsec 530 */ 531 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 532 in_delayed_cksum(m); 533 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 534 } 535 536 ip->ip_len = htons(ip->ip_len); 537 ip->ip_off = htons(ip->ip_off); 538 539 error = ipsec4_output(&state, sp, flags); 540 541 m = state.m; 542 if (flags & IP_ROUTETOIF) { 543 /* 544 * if we have tunnel mode SA, we may need to ignore 545 * IP_ROUTETOIF. 546 */ 547 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 548 flags &= ~IP_ROUTETOIF; 549 ro = state.ro; 550 } 551 } else 552 ro = state.ro; 553 dst = (struct sockaddr_in *)state.dst; 554 if (error) { 555 /* mbuf is already reclaimed in ipsec4_output. */ 556 m0 = NULL; 557 switch (error) { 558 case EHOSTUNREACH: 559 case ENETUNREACH: 560 case EMSGSIZE: 561 case ENOBUFS: 562 case ENOMEM: 563 break; 564 default: 565 printf("ip4_output (ipsec): error code %d\n", error); 566 /*fall through*/ 567 case ENOENT: 568 /* don't show these error codes to the user */ 569 error = 0; 570 break; 571 } 572 goto bad; 573 } 574 } 575 576 /* be sure to update variables that are affected by ipsec4_output() */ 577 ip = mtod(m, struct ip *); 578 #ifdef _IP_VHL 579 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 580 #else 581 hlen = ip->ip_hl << 2; 582 #endif 583 if (ro->ro_rt == NULL) { 584 if ((flags & IP_ROUTETOIF) == 0) { 585 printf("ip_output: " 586 "can't update route after IPsec processing\n"); 587 error = EHOSTUNREACH; /*XXX*/ 588 goto bad; 589 } 590 } else { 591 ia = ifatoia(ro->ro_rt->rt_ifa); 592 ifp = ro->ro_rt->rt_ifp; 593 } 594 595 /* make it flipped, again. */ 596 ip->ip_len = ntohs(ip->ip_len); 597 ip->ip_off = ntohs(ip->ip_off); 598 skip_ipsec: 599 #endif /*IPSEC*/ 600 #ifdef FAST_IPSEC 601 /* 602 * Check the security policy (SP) for the packet and, if 603 * required, do IPsec-related processing. There are two 604 * cases here; the first time a packet is sent through 605 * it will be untagged and handled by ipsec4_checkpolicy. 606 * If the packet is resubmitted to ip_output (e.g. after 607 * AH, ESP, etc. processing), there will be a tag to bypass 608 * the lookup and related policy checking. 609 */ 610 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 611 s = splnet(); 612 if (mtag != NULL) { 613 tdbi = (struct tdb_ident *)(mtag + 1); 614 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 615 if (sp == NULL) 616 error = -EINVAL; /* force silent drop */ 617 m_tag_delete(m, mtag); 618 } else { 619 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 620 &error, inp); 621 } 622 /* 623 * There are four return cases: 624 * sp != NULL apply IPsec policy 625 * sp == NULL, error == 0 no IPsec handling needed 626 * sp == NULL, error == -EINVAL discard packet w/o error 627 * sp == NULL, error != 0 discard packet, report error 628 */ 629 if (sp != NULL) { 630 /* Loop detection, check if ipsec processing already done */ 631 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 632 for (mtag = m_tag_first(m); mtag != NULL; 633 mtag = m_tag_next(m, mtag)) { 634 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 635 continue; 636 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 637 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 638 continue; 639 /* 640 * Check if policy has an SA associated with it. 641 * This can happen when an SP has yet to acquire 642 * an SA; e.g. on first reference. If it occurs, 643 * then we let ipsec4_process_packet do its thing. 644 */ 645 if (sp->req->sav == NULL) 646 break; 647 tdbi = (struct tdb_ident *)(mtag + 1); 648 if (tdbi->spi == sp->req->sav->spi && 649 tdbi->proto == sp->req->sav->sah->saidx.proto && 650 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 651 sizeof (union sockaddr_union)) == 0) { 652 /* 653 * No IPsec processing is needed, free 654 * reference to SP. 655 * 656 * NB: null pointer to avoid free at 657 * done: below. 658 */ 659 KEY_FREESP(&sp), sp = NULL; 660 splx(s); 661 goto spd_done; 662 } 663 } 664 665 /* 666 * Do delayed checksums now because we send before 667 * this is done in the normal processing path. 668 */ 669 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 670 in_delayed_cksum(m); 671 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 672 } 673 674 ip->ip_len = htons(ip->ip_len); 675 ip->ip_off = htons(ip->ip_off); 676 677 /* NB: callee frees mbuf */ 678 error = ipsec4_process_packet(m, sp->req, flags, 0); 679 /* 680 * Preserve KAME behaviour: ENOENT can be returned 681 * when an SA acquire is in progress. Don't propagate 682 * this to user-level; it confuses applications. 683 * 684 * XXX this will go away when the SADB is redone. 685 */ 686 if (error == ENOENT) 687 error = 0; 688 splx(s); 689 goto done; 690 } else { 691 splx(s); 692 693 if (error != 0) { 694 /* 695 * Hack: -EINVAL is used to signal that a packet 696 * should be silently discarded. This is typically 697 * because we asked key management for an SA and 698 * it was delayed (e.g. kicked up to IKE). 699 */ 700 if (error == -EINVAL) 701 error = 0; 702 goto bad; 703 } else { 704 /* No IPsec processing for this packet. */ 705 } 706 #ifdef notyet 707 /* 708 * If deferred crypto processing is needed, check that 709 * the interface supports it. 710 */ 711 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 712 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 713 /* notify IPsec to do its own crypto */ 714 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 715 error = EHOSTUNREACH; 716 goto bad; 717 } 718 #endif 719 } 720 spd_done: 721 #endif /* FAST_IPSEC */ 722 /* 723 * IpHack's section. 724 * - Xlate: translate packet's addr/port (NAT). 725 * - Firewall: deny/allow/etc. 726 * - Wrap: fake packet's addr/port <unimpl.> 727 * - Encapsulate: put it in another IP and send out. <unimp.> 728 */ 729 #ifdef PFIL_HOOKS 730 /* 731 * Run through list of hooks for output packets. 732 */ 733 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 734 if (error != 0 || m == NULL) 735 goto done; 736 ip = mtod(m, struct ip *); 737 #endif /* PFIL_HOOKS */ 738 739 /* 740 * Check with the firewall... 741 * but not if we are already being fwd'd from a firewall. 742 */ 743 if (fw_enable && IPFW_LOADED && !args.next_hop) { 744 struct sockaddr_in *old = dst; 745 746 args.m = m; 747 args.next_hop = dst; 748 args.oif = ifp; 749 off = ip_fw_chk_ptr(&args); 750 m = args.m; 751 dst = args.next_hop; 752 753 /* 754 * On return we must do the following: 755 * m == NULL -> drop the pkt (old interface, deprecated) 756 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 757 * 1<=off<= 0xffff -> DIVERT 758 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 759 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 760 * dst != old -> IPFIREWALL_FORWARD 761 * off==0, dst==old -> accept 762 * If some of the above modules are not compiled in, then 763 * we should't have to check the corresponding condition 764 * (because the ipfw control socket should not accept 765 * unsupported rules), but better play safe and drop 766 * packets in case of doubt. 767 */ 768 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 769 if (m) 770 m_freem(m); 771 error = EACCES; 772 goto done; 773 } 774 ip = mtod(m, struct ip *); 775 if (off == 0 && dst == old) /* common case */ 776 goto pass; 777 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) { 778 /* 779 * pass the pkt to dummynet. Need to include 780 * pipe number, m, ifp, ro, dst because these are 781 * not recomputed in the next pass. 782 * All other parameters have been already used and 783 * so they are not needed anymore. 784 * XXX note: if the ifp or ro entry are deleted 785 * while a pkt is in dummynet, we are in trouble! 786 */ 787 args.ro = ro; 788 args.dst = dst; 789 args.flags = flags; 790 791 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 792 &args); 793 goto done; 794 } 795 #ifdef IPDIVERT 796 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) { 797 struct mbuf *clone = NULL; 798 799 /* Clone packet if we're doing a 'tee' */ 800 if ((off & IP_FW_PORT_TEE_FLAG) != 0) 801 clone = m_dup(m, M_DONTWAIT); 802 803 /* 804 * XXX 805 * delayed checksums are not currently compatible 806 * with divert sockets. 807 */ 808 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 809 in_delayed_cksum(m); 810 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 811 } 812 813 /* Restore packet header fields to original values */ 814 ip->ip_len = htons(ip->ip_len); 815 ip->ip_off = htons(ip->ip_off); 816 817 /* Deliver packet to divert input routine */ 818 divert_packet(m, 0, off & 0xffff, args.divert_rule); 819 820 /* If 'tee', continue with original packet */ 821 if (clone != NULL) { 822 m = clone; 823 ip = mtod(m, struct ip *); 824 goto pass; 825 } 826 goto done; 827 } 828 #endif 829 830 /* IPFIREWALL_FORWARD */ 831 /* 832 * Check dst to make sure it is directly reachable on the 833 * interface we previously thought it was. 834 * If it isn't (which may be likely in some situations) we have 835 * to re-route it (ie, find a route for the next-hop and the 836 * associated interface) and set them here. This is nested 837 * forwarding which in most cases is undesirable, except where 838 * such control is nigh impossible. So we do it here. 839 * And I'm babbling. 840 */ 841 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 842 #if 0 843 /* 844 * XXX To improve readability, this block should be 845 * changed into a function call as below: 846 */ 847 error = ip_ipforward(&m, &dst, &ifp); 848 if (error) 849 goto bad; 850 if (m == NULL) /* ip_input consumed the mbuf */ 851 goto done; 852 #else 853 struct in_ifaddr *ia; 854 855 /* 856 * XXX sro_fwd below is static, and a pointer 857 * to it gets passed to routines downstream. 858 * This could have surprisingly bad results in 859 * practice, because its content is overwritten 860 * by subsequent packets. 861 */ 862 /* There must be a better way to do this next line... */ 863 static struct route sro_fwd; 864 struct route *ro_fwd = &sro_fwd; 865 866 #if 0 867 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 868 dst->sin_addr, "\n"); 869 #endif 870 871 /* 872 * We need to figure out if we have been forwarded 873 * to a local socket. If so, then we should somehow 874 * "loop back" to ip_input, and get directed to the 875 * PCB as if we had received this packet. This is 876 * because it may be dificult to identify the packets 877 * you want to forward until they are being output 878 * and have selected an interface. (e.g. locally 879 * initiated packets) If we used the loopback inteface, 880 * we would not be able to control what happens 881 * as the packet runs through ip_input() as 882 * it is done through a ISR. 883 */ 884 LIST_FOREACH(ia, 885 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 886 /* 887 * If the addr to forward to is one 888 * of ours, we pretend to 889 * be the destination for this packet. 890 */ 891 if (IA_SIN(ia)->sin_addr.s_addr == 892 dst->sin_addr.s_addr) 893 break; 894 } 895 if (ia) { /* tell ip_input "dont filter" */ 896 struct m_hdr tag; 897 898 tag.mh_type = MT_TAG; 899 tag.mh_flags = PACKET_TAG_IPFORWARD; 900 tag.mh_data = (caddr_t)args.next_hop; 901 tag.mh_next = m; 902 903 if (m->m_pkthdr.rcvif == NULL) 904 m->m_pkthdr.rcvif = ifunit("lo0"); 905 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 906 m->m_pkthdr.csum_flags |= 907 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 908 m0->m_pkthdr.csum_data = 0xffff; 909 } 910 m->m_pkthdr.csum_flags |= 911 CSUM_IP_CHECKED | CSUM_IP_VALID; 912 ip->ip_len = htons(ip->ip_len); 913 ip->ip_off = htons(ip->ip_off); 914 ip_input((struct mbuf *)&tag); 915 goto done; 916 } 917 /* Some of the logic for this was 918 * nicked from above. 919 * 920 * This rewrites the cached route in a local PCB. 921 * Is this what we want to do? 922 */ 923 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 924 925 ro_fwd->ro_rt = 0; 926 rtalloc_ign(ro_fwd, RTF_PRCLONING); 927 928 if (ro_fwd->ro_rt == 0) { 929 ipstat.ips_noroute++; 930 error = EHOSTUNREACH; 931 goto bad; 932 } 933 934 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 935 ifp = ro_fwd->ro_rt->rt_ifp; 936 ro_fwd->ro_rt->rt_use++; 937 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 938 dst = (struct sockaddr_in *) 939 ro_fwd->ro_rt->rt_gateway; 940 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 941 isbroadcast = 942 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 943 else 944 isbroadcast = in_broadcast(dst->sin_addr, ifp); 945 if (ro->ro_rt) 946 RTFREE(ro->ro_rt); 947 ro->ro_rt = ro_fwd->ro_rt; 948 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 949 950 #endif /* ... block to be put into a function */ 951 /* 952 * If we added a default src ip earlier, 953 * which would have been gotten from the-then 954 * interface, do it again, from the new one. 955 */ 956 if (src_was_INADDR_ANY) 957 ip->ip_src = IA_SIN(ia)->sin_addr; 958 goto pass ; 959 } 960 961 /* 962 * if we get here, none of the above matches, and 963 * we have to drop the pkt 964 */ 965 m_freem(m); 966 error = EACCES; /* not sure this is the right error msg */ 967 goto done; 968 } 969 970 pass: 971 /* 127/8 must not appear on wire - RFC1122. */ 972 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 973 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 974 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 975 ipstat.ips_badaddr++; 976 error = EADDRNOTAVAIL; 977 goto bad; 978 } 979 } 980 981 m->m_pkthdr.csum_flags |= CSUM_IP; 982 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 983 if (sw_csum & CSUM_DELAY_DATA) { 984 in_delayed_cksum(m); 985 sw_csum &= ~CSUM_DELAY_DATA; 986 } 987 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 988 989 /* 990 * If small enough for interface, or the interface will take 991 * care of the fragmentation for us, can just send directly. 992 */ 993 if (ip->ip_len <= ifp->if_mtu || ifp->if_hwassist & CSUM_FRAGMENT) { 994 ip->ip_len = htons(ip->ip_len); 995 ip->ip_off = htons(ip->ip_off); 996 ip->ip_sum = 0; 997 if (sw_csum & CSUM_DELAY_IP) { 998 if (ip->ip_vhl == IP_VHL_BORING) { 999 ip->ip_sum = in_cksum_hdr(ip); 1000 } else { 1001 ip->ip_sum = in_cksum(m, hlen); 1002 } 1003 } 1004 1005 /* Record statistics for this interface address. */ 1006 if (!(flags & IP_FORWARDING) && ia) { 1007 ia->ia_ifa.if_opackets++; 1008 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1009 } 1010 1011 #ifdef IPSEC 1012 /* clean ipsec history once it goes out of the node */ 1013 ipsec_delaux(m); 1014 #endif 1015 1016 #ifdef MBUF_STRESS_TEST 1017 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 1018 struct mbuf *m1, *m2; 1019 int length, tmp; 1020 1021 tmp = length = m->m_pkthdr.len; 1022 1023 while ((length -= mbuf_frag_size) >= 1) { 1024 m1 = m_split(m, length, M_DONTWAIT); 1025 if (m1 == NULL) 1026 break; 1027 m1->m_flags &= ~M_PKTHDR; 1028 m2 = m; 1029 while (m2->m_next != NULL) 1030 m2 = m2->m_next; 1031 m2->m_next = m1; 1032 } 1033 m->m_pkthdr.len = tmp; 1034 } 1035 #endif 1036 error = (*ifp->if_output)(ifp, m, 1037 (struct sockaddr *)dst, ro->ro_rt); 1038 goto done; 1039 } 1040 1041 if (ip->ip_off & IP_DF) { 1042 error = EMSGSIZE; 1043 /* 1044 * This case can happen if the user changed the MTU 1045 * of an interface after enabling IP on it. Because 1046 * most netifs don't keep track of routes pointing to 1047 * them, there is no way for one to update all its 1048 * routes when the MTU is changed. 1049 */ 1050 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1051 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1052 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1053 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1054 } 1055 ipstat.ips_cantfrag++; 1056 goto bad; 1057 } 1058 1059 /* 1060 * Too large for interface; fragment if possible. If successful, 1061 * on return, m will point to a list of packets to be sent. 1062 */ 1063 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1064 if (error) 1065 goto bad; 1066 for (; m; m = m0) { 1067 m0 = m->m_nextpkt; 1068 m->m_nextpkt = 0; 1069 #ifdef IPSEC 1070 /* clean ipsec history once it goes out of the node */ 1071 ipsec_delaux(m); 1072 #endif 1073 if (error == 0) { 1074 /* Record statistics for this interface address. */ 1075 if (ia != NULL) { 1076 ia->ia_ifa.if_opackets++; 1077 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1078 } 1079 1080 error = (*ifp->if_output)(ifp, m, 1081 (struct sockaddr *)dst, ro->ro_rt); 1082 } else 1083 m_freem(m); 1084 } 1085 1086 if (error == 0) 1087 ipstat.ips_fragmented++; 1088 1089 done: 1090 #ifdef IPSEC 1091 if (ro == &iproute && ro->ro_rt) { 1092 RTFREE(ro->ro_rt); 1093 ro->ro_rt = NULL; 1094 } 1095 if (sp != NULL) { 1096 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1097 printf("DP ip_output call free SP:%p\n", sp)); 1098 key_freesp(sp); 1099 } 1100 #endif 1101 #ifdef FAST_IPSEC 1102 if (ro == &iproute && ro->ro_rt) { 1103 RTFREE(ro->ro_rt); 1104 ro->ro_rt = NULL; 1105 } 1106 if (sp != NULL) 1107 KEY_FREESP(&sp); 1108 #endif 1109 return (error); 1110 bad: 1111 m_freem(m); 1112 goto done; 1113 } 1114 1115 /* 1116 * Create a chain of fragments which fit the given mtu. m_frag points to the 1117 * mbuf to be fragmented; on return it points to the chain with the fragments. 1118 * Return 0 if no error. If error, m_frag may contain a partially built 1119 * chain of fragments that should be freed by the caller. 1120 * 1121 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1122 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1123 */ 1124 int 1125 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1126 u_long if_hwassist_flags, int sw_csum) 1127 { 1128 int error = 0; 1129 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1130 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1131 int off; 1132 struct mbuf *m0 = *m_frag; /* the original packet */ 1133 int firstlen; 1134 struct mbuf **mnext; 1135 int nfrags; 1136 1137 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1138 ipstat.ips_cantfrag++; 1139 return EMSGSIZE; 1140 } 1141 1142 /* 1143 * Must be able to put at least 8 bytes per fragment. 1144 */ 1145 if (len < 8) 1146 return EMSGSIZE; 1147 1148 /* 1149 * If the interface will not calculate checksums on 1150 * fragmented packets, then do it here. 1151 */ 1152 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && 1153 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { 1154 in_delayed_cksum(m0); 1155 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1156 } 1157 1158 if (len > PAGE_SIZE) { 1159 /* 1160 * Fragment large datagrams such that each segment 1161 * contains a multiple of PAGE_SIZE amount of data, 1162 * plus headers. This enables a receiver to perform 1163 * page-flipping zero-copy optimizations. 1164 * 1165 * XXX When does this help given that sender and receiver 1166 * could have different page sizes, and also mtu could 1167 * be less than the receiver's page size ? 1168 */ 1169 int newlen; 1170 struct mbuf *m; 1171 1172 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1173 off += m->m_len; 1174 1175 /* 1176 * firstlen (off - hlen) must be aligned on an 1177 * 8-byte boundary 1178 */ 1179 if (off < hlen) 1180 goto smart_frag_failure; 1181 off = ((off - hlen) & ~7) + hlen; 1182 newlen = (~PAGE_MASK) & mtu; 1183 if ((newlen + sizeof (struct ip)) > mtu) { 1184 /* we failed, go back the default */ 1185 smart_frag_failure: 1186 newlen = len; 1187 off = hlen + len; 1188 } 1189 len = newlen; 1190 1191 } else { 1192 off = hlen + len; 1193 } 1194 1195 firstlen = off - hlen; 1196 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1197 1198 /* 1199 * Loop through length of segment after first fragment, 1200 * make new header and copy data of each part and link onto chain. 1201 * Here, m0 is the original packet, m is the fragment being created. 1202 * The fragments are linked off the m_nextpkt of the original 1203 * packet, which after processing serves as the first fragment. 1204 */ 1205 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1206 struct ip *mhip; /* ip header on the fragment */ 1207 struct mbuf *m; 1208 int mhlen = sizeof (struct ip); 1209 1210 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1211 if (m == 0) { 1212 error = ENOBUFS; 1213 ipstat.ips_odropped++; 1214 goto done; 1215 } 1216 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1217 /* 1218 * In the first mbuf, leave room for the link header, then 1219 * copy the original IP header including options. The payload 1220 * goes into an additional mbuf chain returned by m_copy(). 1221 */ 1222 m->m_data += max_linkhdr; 1223 mhip = mtod(m, struct ip *); 1224 *mhip = *ip; 1225 if (hlen > sizeof (struct ip)) { 1226 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1227 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1228 } 1229 m->m_len = mhlen; 1230 /* XXX do we need to add ip->ip_off below ? */ 1231 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1232 if (off + len >= ip->ip_len) { /* last fragment */ 1233 len = ip->ip_len - off; 1234 m->m_flags |= M_LASTFRAG; 1235 } else 1236 mhip->ip_off |= IP_MF; 1237 mhip->ip_len = htons((u_short)(len + mhlen)); 1238 m->m_next = m_copy(m0, off, len); 1239 if (m->m_next == 0) { /* copy failed */ 1240 m_free(m); 1241 error = ENOBUFS; /* ??? */ 1242 ipstat.ips_odropped++; 1243 goto done; 1244 } 1245 m->m_pkthdr.len = mhlen + len; 1246 m->m_pkthdr.rcvif = (struct ifnet *)0; 1247 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1248 mhip->ip_off = htons(mhip->ip_off); 1249 mhip->ip_sum = 0; 1250 if (sw_csum & CSUM_DELAY_IP) 1251 mhip->ip_sum = in_cksum(m, mhlen); 1252 *mnext = m; 1253 mnext = &m->m_nextpkt; 1254 } 1255 ipstat.ips_ofragments += nfrags; 1256 1257 /* set first marker for fragment chain */ 1258 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1259 m0->m_pkthdr.csum_data = nfrags; 1260 1261 /* 1262 * Update first fragment by trimming what's been copied out 1263 * and updating header. 1264 */ 1265 m_adj(m0, hlen + firstlen - ip->ip_len); 1266 m0->m_pkthdr.len = hlen + firstlen; 1267 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1268 ip->ip_off |= IP_MF; 1269 ip->ip_off = htons(ip->ip_off); 1270 ip->ip_sum = 0; 1271 if (sw_csum & CSUM_DELAY_IP) 1272 ip->ip_sum = in_cksum(m0, hlen); 1273 1274 done: 1275 *m_frag = m0; 1276 return error; 1277 } 1278 1279 void 1280 in_delayed_cksum(struct mbuf *m) 1281 { 1282 struct ip *ip; 1283 u_short csum, offset; 1284 1285 ip = mtod(m, struct ip *); 1286 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1287 csum = in_cksum_skip(m, ip->ip_len, offset); 1288 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1289 csum = 0xffff; 1290 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1291 1292 if (offset + sizeof(u_short) > m->m_len) { 1293 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1294 m->m_len, offset, ip->ip_p); 1295 /* 1296 * XXX 1297 * this shouldn't happen, but if it does, the 1298 * correct behavior may be to insert the checksum 1299 * in the existing chain instead of rearranging it. 1300 */ 1301 m = m_pullup(m, offset + sizeof(u_short)); 1302 } 1303 *(u_short *)(m->m_data + offset) = csum; 1304 } 1305 1306 /* 1307 * Insert IP options into preformed packet. 1308 * Adjust IP destination as required for IP source routing, 1309 * as indicated by a non-zero in_addr at the start of the options. 1310 * 1311 * XXX This routine assumes that the packet has no options in place. 1312 */ 1313 static struct mbuf * 1314 ip_insertoptions(m, opt, phlen) 1315 struct mbuf *m; 1316 struct mbuf *opt; 1317 int *phlen; 1318 { 1319 struct ipoption *p = mtod(opt, struct ipoption *); 1320 struct mbuf *n; 1321 struct ip *ip = mtod(m, struct ip *); 1322 unsigned optlen; 1323 1324 optlen = opt->m_len - sizeof(p->ipopt_dst); 1325 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1326 *phlen = 0; 1327 return (m); /* XXX should fail */ 1328 } 1329 if (p->ipopt_dst.s_addr) 1330 ip->ip_dst = p->ipopt_dst; 1331 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1332 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1333 if (n == 0) { 1334 *phlen = 0; 1335 return (m); 1336 } 1337 n->m_pkthdr.rcvif = (struct ifnet *)0; 1338 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1339 m->m_len -= sizeof(struct ip); 1340 m->m_data += sizeof(struct ip); 1341 n->m_next = m; 1342 m = n; 1343 m->m_len = optlen + sizeof(struct ip); 1344 m->m_data += max_linkhdr; 1345 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1346 } else { 1347 m->m_data -= optlen; 1348 m->m_len += optlen; 1349 m->m_pkthdr.len += optlen; 1350 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1351 } 1352 ip = mtod(m, struct ip *); 1353 bcopy(p->ipopt_list, ip + 1, optlen); 1354 *phlen = sizeof(struct ip) + optlen; 1355 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1356 ip->ip_len += optlen; 1357 return (m); 1358 } 1359 1360 /* 1361 * Copy options from ip to jp, 1362 * omitting those not copied during fragmentation. 1363 */ 1364 int 1365 ip_optcopy(ip, jp) 1366 struct ip *ip, *jp; 1367 { 1368 u_char *cp, *dp; 1369 int opt, optlen, cnt; 1370 1371 cp = (u_char *)(ip + 1); 1372 dp = (u_char *)(jp + 1); 1373 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 1374 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1375 opt = cp[0]; 1376 if (opt == IPOPT_EOL) 1377 break; 1378 if (opt == IPOPT_NOP) { 1379 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1380 *dp++ = IPOPT_NOP; 1381 optlen = 1; 1382 continue; 1383 } 1384 1385 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 1386 ("ip_optcopy: malformed ipv4 option")); 1387 optlen = cp[IPOPT_OLEN]; 1388 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 1389 ("ip_optcopy: malformed ipv4 option")); 1390 1391 /* bogus lengths should have been caught by ip_dooptions */ 1392 if (optlen > cnt) 1393 optlen = cnt; 1394 if (IPOPT_COPIED(opt)) { 1395 bcopy(cp, dp, optlen); 1396 dp += optlen; 1397 } 1398 } 1399 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1400 *dp++ = IPOPT_EOL; 1401 return (optlen); 1402 } 1403 1404 /* 1405 * IP socket option processing. 1406 */ 1407 int 1408 ip_ctloutput(so, sopt) 1409 struct socket *so; 1410 struct sockopt *sopt; 1411 { 1412 struct inpcb *inp = sotoinpcb(so); 1413 int error, optval; 1414 1415 error = optval = 0; 1416 if (sopt->sopt_level != IPPROTO_IP) { 1417 return (EINVAL); 1418 } 1419 1420 switch (sopt->sopt_dir) { 1421 case SOPT_SET: 1422 switch (sopt->sopt_name) { 1423 case IP_OPTIONS: 1424 #ifdef notyet 1425 case IP_RETOPTS: 1426 #endif 1427 { 1428 struct mbuf *m; 1429 if (sopt->sopt_valsize > MLEN) { 1430 error = EMSGSIZE; 1431 break; 1432 } 1433 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_HEADER); 1434 if (m == 0) { 1435 error = ENOBUFS; 1436 break; 1437 } 1438 m->m_len = sopt->sopt_valsize; 1439 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1440 m->m_len); 1441 1442 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1443 m)); 1444 } 1445 1446 case IP_TOS: 1447 case IP_TTL: 1448 case IP_RECVOPTS: 1449 case IP_RECVRETOPTS: 1450 case IP_RECVDSTADDR: 1451 case IP_RECVIF: 1452 case IP_FAITH: 1453 error = sooptcopyin(sopt, &optval, sizeof optval, 1454 sizeof optval); 1455 if (error) 1456 break; 1457 1458 switch (sopt->sopt_name) { 1459 case IP_TOS: 1460 inp->inp_ip_tos = optval; 1461 break; 1462 1463 case IP_TTL: 1464 inp->inp_ip_ttl = optval; 1465 break; 1466 #define OPTSET(bit) \ 1467 if (optval) \ 1468 inp->inp_flags |= bit; \ 1469 else \ 1470 inp->inp_flags &= ~bit; 1471 1472 case IP_RECVOPTS: 1473 OPTSET(INP_RECVOPTS); 1474 break; 1475 1476 case IP_RECVRETOPTS: 1477 OPTSET(INP_RECVRETOPTS); 1478 break; 1479 1480 case IP_RECVDSTADDR: 1481 OPTSET(INP_RECVDSTADDR); 1482 break; 1483 1484 case IP_RECVIF: 1485 OPTSET(INP_RECVIF); 1486 break; 1487 1488 case IP_FAITH: 1489 OPTSET(INP_FAITH); 1490 break; 1491 } 1492 break; 1493 #undef OPTSET 1494 1495 case IP_MULTICAST_IF: 1496 case IP_MULTICAST_VIF: 1497 case IP_MULTICAST_TTL: 1498 case IP_MULTICAST_LOOP: 1499 case IP_ADD_MEMBERSHIP: 1500 case IP_DROP_MEMBERSHIP: 1501 error = ip_setmoptions(sopt, &inp->inp_moptions); 1502 break; 1503 1504 case IP_PORTRANGE: 1505 error = sooptcopyin(sopt, &optval, sizeof optval, 1506 sizeof optval); 1507 if (error) 1508 break; 1509 1510 switch (optval) { 1511 case IP_PORTRANGE_DEFAULT: 1512 inp->inp_flags &= ~(INP_LOWPORT); 1513 inp->inp_flags &= ~(INP_HIGHPORT); 1514 break; 1515 1516 case IP_PORTRANGE_HIGH: 1517 inp->inp_flags &= ~(INP_LOWPORT); 1518 inp->inp_flags |= INP_HIGHPORT; 1519 break; 1520 1521 case IP_PORTRANGE_LOW: 1522 inp->inp_flags &= ~(INP_HIGHPORT); 1523 inp->inp_flags |= INP_LOWPORT; 1524 break; 1525 1526 default: 1527 error = EINVAL; 1528 break; 1529 } 1530 break; 1531 1532 #if defined(IPSEC) || defined(FAST_IPSEC) 1533 case IP_IPSEC_POLICY: 1534 { 1535 caddr_t req; 1536 size_t len = 0; 1537 int priv; 1538 struct mbuf *m; 1539 int optname; 1540 1541 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1542 break; 1543 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1544 break; 1545 priv = (sopt->sopt_td != NULL && 1546 suser(sopt->sopt_td) != 0) ? 0 : 1; 1547 req = mtod(m, caddr_t); 1548 len = m->m_len; 1549 optname = sopt->sopt_name; 1550 error = ipsec4_set_policy(inp, optname, req, len, priv); 1551 m_freem(m); 1552 break; 1553 } 1554 #endif /*IPSEC*/ 1555 1556 default: 1557 error = ENOPROTOOPT; 1558 break; 1559 } 1560 break; 1561 1562 case SOPT_GET: 1563 switch (sopt->sopt_name) { 1564 case IP_OPTIONS: 1565 case IP_RETOPTS: 1566 if (inp->inp_options) 1567 error = sooptcopyout(sopt, 1568 mtod(inp->inp_options, 1569 char *), 1570 inp->inp_options->m_len); 1571 else 1572 sopt->sopt_valsize = 0; 1573 break; 1574 1575 case IP_TOS: 1576 case IP_TTL: 1577 case IP_RECVOPTS: 1578 case IP_RECVRETOPTS: 1579 case IP_RECVDSTADDR: 1580 case IP_RECVIF: 1581 case IP_PORTRANGE: 1582 case IP_FAITH: 1583 switch (sopt->sopt_name) { 1584 1585 case IP_TOS: 1586 optval = inp->inp_ip_tos; 1587 break; 1588 1589 case IP_TTL: 1590 optval = inp->inp_ip_ttl; 1591 break; 1592 1593 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1594 1595 case IP_RECVOPTS: 1596 optval = OPTBIT(INP_RECVOPTS); 1597 break; 1598 1599 case IP_RECVRETOPTS: 1600 optval = OPTBIT(INP_RECVRETOPTS); 1601 break; 1602 1603 case IP_RECVDSTADDR: 1604 optval = OPTBIT(INP_RECVDSTADDR); 1605 break; 1606 1607 case IP_RECVIF: 1608 optval = OPTBIT(INP_RECVIF); 1609 break; 1610 1611 case IP_PORTRANGE: 1612 if (inp->inp_flags & INP_HIGHPORT) 1613 optval = IP_PORTRANGE_HIGH; 1614 else if (inp->inp_flags & INP_LOWPORT) 1615 optval = IP_PORTRANGE_LOW; 1616 else 1617 optval = 0; 1618 break; 1619 1620 case IP_FAITH: 1621 optval = OPTBIT(INP_FAITH); 1622 break; 1623 } 1624 error = sooptcopyout(sopt, &optval, sizeof optval); 1625 break; 1626 1627 case IP_MULTICAST_IF: 1628 case IP_MULTICAST_VIF: 1629 case IP_MULTICAST_TTL: 1630 case IP_MULTICAST_LOOP: 1631 case IP_ADD_MEMBERSHIP: 1632 case IP_DROP_MEMBERSHIP: 1633 error = ip_getmoptions(sopt, inp->inp_moptions); 1634 break; 1635 1636 #if defined(IPSEC) || defined(FAST_IPSEC) 1637 case IP_IPSEC_POLICY: 1638 { 1639 struct mbuf *m = NULL; 1640 caddr_t req = NULL; 1641 size_t len = 0; 1642 1643 if (m != 0) { 1644 req = mtod(m, caddr_t); 1645 len = m->m_len; 1646 } 1647 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m); 1648 if (error == 0) 1649 error = soopt_mcopyout(sopt, m); /* XXX */ 1650 if (error == 0) 1651 m_freem(m); 1652 break; 1653 } 1654 #endif /*IPSEC*/ 1655 1656 default: 1657 error = ENOPROTOOPT; 1658 break; 1659 } 1660 break; 1661 } 1662 return (error); 1663 } 1664 1665 /* 1666 * Set up IP options in pcb for insertion in output packets. 1667 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1668 * with destination address if source routed. 1669 */ 1670 static int 1671 ip_pcbopts(optname, pcbopt, m) 1672 int optname; 1673 struct mbuf **pcbopt; 1674 struct mbuf *m; 1675 { 1676 int cnt, optlen; 1677 u_char *cp; 1678 u_char opt; 1679 1680 /* turn off any old options */ 1681 if (*pcbopt) 1682 (void)m_free(*pcbopt); 1683 *pcbopt = 0; 1684 if (m == (struct mbuf *)0 || m->m_len == 0) { 1685 /* 1686 * Only turning off any previous options. 1687 */ 1688 if (m) 1689 (void)m_free(m); 1690 return (0); 1691 } 1692 1693 if (m->m_len % sizeof(int32_t)) 1694 goto bad; 1695 /* 1696 * IP first-hop destination address will be stored before 1697 * actual options; move other options back 1698 * and clear it when none present. 1699 */ 1700 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1701 goto bad; 1702 cnt = m->m_len; 1703 m->m_len += sizeof(struct in_addr); 1704 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1705 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 1706 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1707 1708 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1709 opt = cp[IPOPT_OPTVAL]; 1710 if (opt == IPOPT_EOL) 1711 break; 1712 if (opt == IPOPT_NOP) 1713 optlen = 1; 1714 else { 1715 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1716 goto bad; 1717 optlen = cp[IPOPT_OLEN]; 1718 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1719 goto bad; 1720 } 1721 switch (opt) { 1722 1723 default: 1724 break; 1725 1726 case IPOPT_LSRR: 1727 case IPOPT_SSRR: 1728 /* 1729 * user process specifies route as: 1730 * ->A->B->C->D 1731 * D must be our final destination (but we can't 1732 * check that since we may not have connected yet). 1733 * A is first hop destination, which doesn't appear in 1734 * actual IP option, but is stored before the options. 1735 */ 1736 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1737 goto bad; 1738 m->m_len -= sizeof(struct in_addr); 1739 cnt -= sizeof(struct in_addr); 1740 optlen -= sizeof(struct in_addr); 1741 cp[IPOPT_OLEN] = optlen; 1742 /* 1743 * Move first hop before start of options. 1744 */ 1745 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1746 sizeof(struct in_addr)); 1747 /* 1748 * Then copy rest of options back 1749 * to close up the deleted entry. 1750 */ 1751 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1752 sizeof(struct in_addr)), 1753 (caddr_t)&cp[IPOPT_OFFSET+1], 1754 (unsigned)cnt + sizeof(struct in_addr)); 1755 break; 1756 } 1757 } 1758 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1759 goto bad; 1760 *pcbopt = m; 1761 return (0); 1762 1763 bad: 1764 (void)m_free(m); 1765 return (EINVAL); 1766 } 1767 1768 /* 1769 * XXX 1770 * The whole multicast option thing needs to be re-thought. 1771 * Several of these options are equally applicable to non-multicast 1772 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1773 * standard option (IP_TTL). 1774 */ 1775 1776 /* 1777 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1778 */ 1779 static struct ifnet * 1780 ip_multicast_if(a, ifindexp) 1781 struct in_addr *a; 1782 int *ifindexp; 1783 { 1784 int ifindex; 1785 struct ifnet *ifp; 1786 1787 if (ifindexp) 1788 *ifindexp = 0; 1789 if (ntohl(a->s_addr) >> 24 == 0) { 1790 ifindex = ntohl(a->s_addr) & 0xffffff; 1791 if (ifindex < 0 || if_index < ifindex) 1792 return NULL; 1793 ifp = ifindex2ifnet[ifindex]; 1794 if (ifindexp) 1795 *ifindexp = ifindex; 1796 } else { 1797 INADDR_TO_IFP(*a, ifp); 1798 } 1799 return ifp; 1800 } 1801 1802 /* 1803 * Set the IP multicast options in response to user setsockopt(). 1804 */ 1805 static int 1806 ip_setmoptions(sopt, imop) 1807 struct sockopt *sopt; 1808 struct ip_moptions **imop; 1809 { 1810 int error = 0; 1811 int i; 1812 struct in_addr addr; 1813 struct ip_mreq mreq; 1814 struct ifnet *ifp; 1815 struct ip_moptions *imo = *imop; 1816 struct route ro; 1817 struct sockaddr_in *dst; 1818 int ifindex; 1819 int s; 1820 1821 if (imo == NULL) { 1822 /* 1823 * No multicast option buffer attached to the pcb; 1824 * allocate one and initialize to default values. 1825 */ 1826 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1827 M_WAITOK); 1828 1829 if (imo == NULL) 1830 return (ENOBUFS); 1831 *imop = imo; 1832 imo->imo_multicast_ifp = NULL; 1833 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1834 imo->imo_multicast_vif = -1; 1835 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1836 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1837 imo->imo_num_memberships = 0; 1838 } 1839 1840 switch (sopt->sopt_name) { 1841 /* store an index number for the vif you wanna use in the send */ 1842 case IP_MULTICAST_VIF: 1843 if (legal_vif_num == 0) { 1844 error = EOPNOTSUPP; 1845 break; 1846 } 1847 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1848 if (error) 1849 break; 1850 if (!legal_vif_num(i) && (i != -1)) { 1851 error = EINVAL; 1852 break; 1853 } 1854 imo->imo_multicast_vif = i; 1855 break; 1856 1857 case IP_MULTICAST_IF: 1858 /* 1859 * Select the interface for outgoing multicast packets. 1860 */ 1861 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1862 if (error) 1863 break; 1864 /* 1865 * INADDR_ANY is used to remove a previous selection. 1866 * When no interface is selected, a default one is 1867 * chosen every time a multicast packet is sent. 1868 */ 1869 if (addr.s_addr == INADDR_ANY) { 1870 imo->imo_multicast_ifp = NULL; 1871 break; 1872 } 1873 /* 1874 * The selected interface is identified by its local 1875 * IP address. Find the interface and confirm that 1876 * it supports multicasting. 1877 */ 1878 s = splimp(); 1879 ifp = ip_multicast_if(&addr, &ifindex); 1880 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1881 splx(s); 1882 error = EADDRNOTAVAIL; 1883 break; 1884 } 1885 imo->imo_multicast_ifp = ifp; 1886 if (ifindex) 1887 imo->imo_multicast_addr = addr; 1888 else 1889 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1890 splx(s); 1891 break; 1892 1893 case IP_MULTICAST_TTL: 1894 /* 1895 * Set the IP time-to-live for outgoing multicast packets. 1896 * The original multicast API required a char argument, 1897 * which is inconsistent with the rest of the socket API. 1898 * We allow either a char or an int. 1899 */ 1900 if (sopt->sopt_valsize == 1) { 1901 u_char ttl; 1902 error = sooptcopyin(sopt, &ttl, 1, 1); 1903 if (error) 1904 break; 1905 imo->imo_multicast_ttl = ttl; 1906 } else { 1907 u_int ttl; 1908 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1909 sizeof ttl); 1910 if (error) 1911 break; 1912 if (ttl > 255) 1913 error = EINVAL; 1914 else 1915 imo->imo_multicast_ttl = ttl; 1916 } 1917 break; 1918 1919 case IP_MULTICAST_LOOP: 1920 /* 1921 * Set the loopback flag for outgoing multicast packets. 1922 * Must be zero or one. The original multicast API required a 1923 * char argument, which is inconsistent with the rest 1924 * of the socket API. We allow either a char or an int. 1925 */ 1926 if (sopt->sopt_valsize == 1) { 1927 u_char loop; 1928 error = sooptcopyin(sopt, &loop, 1, 1); 1929 if (error) 1930 break; 1931 imo->imo_multicast_loop = !!loop; 1932 } else { 1933 u_int loop; 1934 error = sooptcopyin(sopt, &loop, sizeof loop, 1935 sizeof loop); 1936 if (error) 1937 break; 1938 imo->imo_multicast_loop = !!loop; 1939 } 1940 break; 1941 1942 case IP_ADD_MEMBERSHIP: 1943 /* 1944 * Add a multicast group membership. 1945 * Group must be a valid IP multicast address. 1946 */ 1947 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1948 if (error) 1949 break; 1950 1951 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1952 error = EINVAL; 1953 break; 1954 } 1955 s = splimp(); 1956 /* 1957 * If no interface address was provided, use the interface of 1958 * the route to the given multicast address. 1959 */ 1960 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1961 bzero((caddr_t)&ro, sizeof(ro)); 1962 dst = (struct sockaddr_in *)&ro.ro_dst; 1963 dst->sin_len = sizeof(*dst); 1964 dst->sin_family = AF_INET; 1965 dst->sin_addr = mreq.imr_multiaddr; 1966 rtalloc(&ro); 1967 if (ro.ro_rt == NULL) { 1968 error = EADDRNOTAVAIL; 1969 splx(s); 1970 break; 1971 } 1972 ifp = ro.ro_rt->rt_ifp; 1973 rtfree(ro.ro_rt); 1974 } 1975 else { 1976 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1977 } 1978 1979 /* 1980 * See if we found an interface, and confirm that it 1981 * supports multicast. 1982 */ 1983 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1984 error = EADDRNOTAVAIL; 1985 splx(s); 1986 break; 1987 } 1988 /* 1989 * See if the membership already exists or if all the 1990 * membership slots are full. 1991 */ 1992 for (i = 0; i < imo->imo_num_memberships; ++i) { 1993 if (imo->imo_membership[i]->inm_ifp == ifp && 1994 imo->imo_membership[i]->inm_addr.s_addr 1995 == mreq.imr_multiaddr.s_addr) 1996 break; 1997 } 1998 if (i < imo->imo_num_memberships) { 1999 error = EADDRINUSE; 2000 splx(s); 2001 break; 2002 } 2003 if (i == IP_MAX_MEMBERSHIPS) { 2004 error = ETOOMANYREFS; 2005 splx(s); 2006 break; 2007 } 2008 /* 2009 * Everything looks good; add a new record to the multicast 2010 * address list for the given interface. 2011 */ 2012 if ((imo->imo_membership[i] = 2013 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 2014 error = ENOBUFS; 2015 splx(s); 2016 break; 2017 } 2018 ++imo->imo_num_memberships; 2019 splx(s); 2020 break; 2021 2022 case IP_DROP_MEMBERSHIP: 2023 /* 2024 * Drop a multicast group membership. 2025 * Group must be a valid IP multicast address. 2026 */ 2027 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2028 if (error) 2029 break; 2030 2031 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2032 error = EINVAL; 2033 break; 2034 } 2035 2036 s = splimp(); 2037 /* 2038 * If an interface address was specified, get a pointer 2039 * to its ifnet structure. 2040 */ 2041 if (mreq.imr_interface.s_addr == INADDR_ANY) 2042 ifp = NULL; 2043 else { 2044 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2045 if (ifp == NULL) { 2046 error = EADDRNOTAVAIL; 2047 splx(s); 2048 break; 2049 } 2050 } 2051 /* 2052 * Find the membership in the membership array. 2053 */ 2054 for (i = 0; i < imo->imo_num_memberships; ++i) { 2055 if ((ifp == NULL || 2056 imo->imo_membership[i]->inm_ifp == ifp) && 2057 imo->imo_membership[i]->inm_addr.s_addr == 2058 mreq.imr_multiaddr.s_addr) 2059 break; 2060 } 2061 if (i == imo->imo_num_memberships) { 2062 error = EADDRNOTAVAIL; 2063 splx(s); 2064 break; 2065 } 2066 /* 2067 * Give up the multicast address record to which the 2068 * membership points. 2069 */ 2070 in_delmulti(imo->imo_membership[i]); 2071 /* 2072 * Remove the gap in the membership array. 2073 */ 2074 for (++i; i < imo->imo_num_memberships; ++i) 2075 imo->imo_membership[i-1] = imo->imo_membership[i]; 2076 --imo->imo_num_memberships; 2077 splx(s); 2078 break; 2079 2080 default: 2081 error = EOPNOTSUPP; 2082 break; 2083 } 2084 2085 /* 2086 * If all options have default values, no need to keep the mbuf. 2087 */ 2088 if (imo->imo_multicast_ifp == NULL && 2089 imo->imo_multicast_vif == -1 && 2090 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2091 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2092 imo->imo_num_memberships == 0) { 2093 free(*imop, M_IPMOPTS); 2094 *imop = NULL; 2095 } 2096 2097 return (error); 2098 } 2099 2100 /* 2101 * Return the IP multicast options in response to user getsockopt(). 2102 */ 2103 static int 2104 ip_getmoptions(sopt, imo) 2105 struct sockopt *sopt; 2106 struct ip_moptions *imo; 2107 { 2108 struct in_addr addr; 2109 struct in_ifaddr *ia; 2110 int error, optval; 2111 u_char coptval; 2112 2113 error = 0; 2114 switch (sopt->sopt_name) { 2115 case IP_MULTICAST_VIF: 2116 if (imo != NULL) 2117 optval = imo->imo_multicast_vif; 2118 else 2119 optval = -1; 2120 error = sooptcopyout(sopt, &optval, sizeof optval); 2121 break; 2122 2123 case IP_MULTICAST_IF: 2124 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2125 addr.s_addr = INADDR_ANY; 2126 else if (imo->imo_multicast_addr.s_addr) { 2127 /* return the value user has set */ 2128 addr = imo->imo_multicast_addr; 2129 } else { 2130 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2131 addr.s_addr = (ia == NULL) ? INADDR_ANY 2132 : IA_SIN(ia)->sin_addr.s_addr; 2133 } 2134 error = sooptcopyout(sopt, &addr, sizeof addr); 2135 break; 2136 2137 case IP_MULTICAST_TTL: 2138 if (imo == 0) 2139 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2140 else 2141 optval = coptval = imo->imo_multicast_ttl; 2142 if (sopt->sopt_valsize == 1) 2143 error = sooptcopyout(sopt, &coptval, 1); 2144 else 2145 error = sooptcopyout(sopt, &optval, sizeof optval); 2146 break; 2147 2148 case IP_MULTICAST_LOOP: 2149 if (imo == 0) 2150 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2151 else 2152 optval = coptval = imo->imo_multicast_loop; 2153 if (sopt->sopt_valsize == 1) 2154 error = sooptcopyout(sopt, &coptval, 1); 2155 else 2156 error = sooptcopyout(sopt, &optval, sizeof optval); 2157 break; 2158 2159 default: 2160 error = ENOPROTOOPT; 2161 break; 2162 } 2163 return (error); 2164 } 2165 2166 /* 2167 * Discard the IP multicast options. 2168 */ 2169 void 2170 ip_freemoptions(imo) 2171 struct ip_moptions *imo; 2172 { 2173 int i; 2174 2175 if (imo != NULL) { 2176 for (i = 0; i < imo->imo_num_memberships; ++i) 2177 in_delmulti(imo->imo_membership[i]); 2178 free(imo, M_IPMOPTS); 2179 } 2180 } 2181 2182 /* 2183 * Routine called from ip_output() to loop back a copy of an IP multicast 2184 * packet to the input queue of a specified interface. Note that this 2185 * calls the output routine of the loopback "driver", but with an interface 2186 * pointer that might NOT be a loopback interface -- evil, but easier than 2187 * replicating that code here. 2188 */ 2189 static void 2190 ip_mloopback(ifp, m, dst, hlen) 2191 struct ifnet *ifp; 2192 struct mbuf *m; 2193 struct sockaddr_in *dst; 2194 int hlen; 2195 { 2196 struct ip *ip; 2197 struct mbuf *copym; 2198 2199 copym = m_copy(m, 0, M_COPYALL); 2200 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2201 copym = m_pullup(copym, hlen); 2202 if (copym != NULL) { 2203 /* 2204 * We don't bother to fragment if the IP length is greater 2205 * than the interface's MTU. Can this possibly matter? 2206 */ 2207 ip = mtod(copym, struct ip *); 2208 ip->ip_len = htons(ip->ip_len); 2209 ip->ip_off = htons(ip->ip_off); 2210 ip->ip_sum = 0; 2211 if (ip->ip_vhl == IP_VHL_BORING) { 2212 ip->ip_sum = in_cksum_hdr(ip); 2213 } else { 2214 ip->ip_sum = in_cksum(copym, hlen); 2215 } 2216 /* 2217 * NB: 2218 * It's not clear whether there are any lingering 2219 * reentrancy problems in other areas which might 2220 * be exposed by using ip_input directly (in 2221 * particular, everything which modifies the packet 2222 * in-place). Yet another option is using the 2223 * protosw directly to deliver the looped back 2224 * packet. For the moment, we'll err on the side 2225 * of safety by using if_simloop(). 2226 */ 2227 #if 1 /* XXX */ 2228 if (dst->sin_family != AF_INET) { 2229 printf("ip_mloopback: bad address family %d\n", 2230 dst->sin_family); 2231 dst->sin_family = AF_INET; 2232 } 2233 #endif 2234 2235 #ifdef notdef 2236 copym->m_pkthdr.rcvif = ifp; 2237 ip_input(copym); 2238 #else 2239 /* if the checksum hasn't been computed, mark it as valid */ 2240 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2241 copym->m_pkthdr.csum_flags |= 2242 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2243 copym->m_pkthdr.csum_data = 0xffff; 2244 } 2245 if_simloop(ifp, copym, dst->sin_family, 0); 2246 #endif 2247 } 2248 } 2249