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 1.46 2008/07/07 22:02:10 nant 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_mbuf_stress_test.h" 42 #include "opt_mpls.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/sysctl.h> 54 #include <sys/thread2.h> 55 #include <sys/in_cksum.h> 56 57 #include <net/if.h> 58 #include <net/netisr.h> 59 #include <net/pfil.h> 60 #include <net/route.h> 61 62 #include <netinet/in.h> 63 #include <netinet/in_systm.h> 64 #include <netinet/ip.h> 65 #include <netinet/in_pcb.h> 66 #include <netinet/in_var.h> 67 #include <netinet/ip_var.h> 68 69 #include <netproto/mpls/mpls_var.h> 70 71 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 72 73 #ifdef IPSEC 74 #include <netinet6/ipsec.h> 75 #include <netproto/key/key.h> 76 #ifdef IPSEC_DEBUG 77 #include <netproto/key/key_debug.h> 78 #else 79 #define KEYDEBUG(lev,arg) 80 #endif 81 #endif /*IPSEC*/ 82 83 #ifdef FAST_IPSEC 84 #include <netproto/ipsec/ipsec.h> 85 #include <netproto/ipsec/xform.h> 86 #include <netproto/ipsec/key.h> 87 #endif /*FAST_IPSEC*/ 88 89 #include <net/ipfw/ip_fw.h> 90 #include <net/dummynet/ip_dummynet.h> 91 92 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\ 93 x, (ntohl(a.s_addr)>>24)&0xFF,\ 94 (ntohl(a.s_addr)>>16)&0xFF,\ 95 (ntohl(a.s_addr)>>8)&0xFF,\ 96 (ntohl(a.s_addr))&0xFF, y); 97 98 u_short ip_id; 99 100 #ifdef MBUF_STRESS_TEST 101 int mbuf_frag_size = 0; 102 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 103 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 104 #endif 105 106 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 107 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 108 static void ip_mloopback 109 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 110 static int ip_getmoptions 111 (struct sockopt *, struct ip_moptions *); 112 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 113 static int ip_setmoptions 114 (struct sockopt *, struct ip_moptions **); 115 116 int ip_optcopy(struct ip *, struct ip *); 117 118 119 extern struct protosw inetsw[]; 120 121 /* 122 * IP output. The packet in mbuf chain m contains a skeletal IP 123 * header (with len, off, ttl, proto, tos, src, dst). 124 * The mbuf chain containing the packet will be freed. 125 * The mbuf opt, if present, will not be freed. 126 */ 127 int 128 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 129 int flags, struct ip_moptions *imo, struct inpcb *inp) 130 { 131 struct ip *ip; 132 struct ifnet *ifp = NULL; /* keep compiler happy */ 133 struct mbuf *m; 134 int hlen = sizeof(struct ip); 135 int len, off, error = 0; 136 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 137 struct in_ifaddr *ia = NULL; 138 int isbroadcast, sw_csum; 139 struct in_addr pkt_dst; 140 struct route iproute; 141 struct m_tag *dn_mtag = NULL; 142 #ifdef IPSEC 143 struct secpolicy *sp = NULL; 144 struct socket *so = inp ? inp->inp_socket : NULL; 145 #endif 146 #ifdef FAST_IPSEC 147 struct m_tag *mtag; 148 struct secpolicy *sp = NULL; 149 struct tdb_ident *tdbi; 150 #endif /* FAST_IPSEC */ 151 struct ip_fw_args args; 152 int src_was_INADDR_ANY = 0; /* as the name says... */ 153 154 args.eh = NULL; 155 args.rule = NULL; 156 args.next_hop = NULL; 157 158 /* Grab info from MT_TAG mbufs prepended to the chain. */ 159 while (m0 != NULL && m0->m_type == MT_TAG) { 160 switch(m0->_m_tag_id) { 161 case PACKET_TAG_IPFORWARD: 162 args.next_hop = (struct sockaddr_in *)m0->m_data; 163 break; 164 default: 165 kprintf("ip_output: unrecognised MT_TAG tag %d\n", 166 m0->_m_tag_id); 167 break; 168 } 169 m0 = m0->m_next; 170 } 171 m = m0; 172 M_ASSERTPKTHDR(m); 173 174 /* Extract info from dummynet tag */ 175 dn_mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 176 if (dn_mtag != NULL) { 177 struct dn_pkt *dn_pkt = m_tag_data(dn_mtag); 178 179 /* 180 * The packet was already tagged, so part of the 181 * processing was already done, and we need to go down. 182 * Get parameters from the tag. 183 */ 184 args.rule = dn_pkt->dn_priv; 185 opt = NULL; 186 ro = &dn_pkt->ro; 187 imo = NULL; 188 dst = dn_pkt->dn_dst; 189 ifp = dn_pkt->ifp; 190 flags = dn_pkt->flags; 191 192 /* 193 * Don't delete the dummynet tag here, just unlink it, 194 * since some local variables (like 'ro' and 'dst') are 195 * still referencing certain parts of it. 196 * The dummynet tag will be freed at the end of the 197 * output process. 198 */ 199 m_tag_unlink(m, dn_mtag); 200 } 201 202 if (ro == NULL) { 203 ro = &iproute; 204 bzero(ro, sizeof *ro); 205 } 206 207 if (args.rule != NULL) { /* dummynet already saw us */ 208 ip = mtod(m, struct ip *); 209 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 210 if (ro->ro_rt) 211 ia = ifatoia(ro->ro_rt->rt_ifa); 212 goto sendit; 213 } 214 215 if (opt) { 216 len = 0; 217 m = ip_insertoptions(m, opt, &len); 218 if (len != 0) 219 hlen = len; 220 } 221 ip = mtod(m, struct ip *); 222 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 223 224 /* 225 * Fill in IP header. 226 */ 227 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 228 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 229 ip->ip_off &= IP_DF; 230 ip->ip_id = ip_newid(); 231 ipstat.ips_localout++; 232 } else { 233 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 234 } 235 236 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 && 245 (!(ro->ro_rt->rt_flags & RTF_UP) || 246 dst->sin_family != AF_INET || 247 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 248 rtfree(ro->ro_rt); 249 ro->ro_rt = (struct rtentry *)NULL; 250 } 251 if (ro->ro_rt == NULL) { 252 bzero(dst, sizeof *dst); 253 dst->sin_family = AF_INET; 254 dst->sin_len = sizeof *dst; 255 dst->sin_addr = pkt_dst; 256 } 257 /* 258 * If routing to interface only, 259 * short circuit routing lookup. 260 */ 261 if (flags & IP_ROUTETOIF) { 262 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 263 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 264 ipstat.ips_noroute++; 265 error = ENETUNREACH; 266 goto bad; 267 } 268 ifp = ia->ia_ifp; 269 ip->ip_ttl = 1; 270 isbroadcast = in_broadcast(dst->sin_addr, ifp); 271 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 272 imo != NULL && imo->imo_multicast_ifp != NULL) { 273 /* 274 * Bypass the normal routing lookup for multicast 275 * packets if the interface is specified. 276 */ 277 ifp = imo->imo_multicast_ifp; 278 ia = IFP_TO_IA(ifp); 279 isbroadcast = 0; /* fool gcc */ 280 } else { 281 /* 282 * If this is the case, we probably don't want to allocate 283 * a protocol-cloned route since we didn't get one from the 284 * ULP. This lets TCP do its thing, while not burdening 285 * forwarding or ICMP with the overhead of cloning a route. 286 * Of course, we still want to do any cloning requested by 287 * the link layer, as this is probably required in all cases 288 * for correct operation (as it is for ARP). 289 */ 290 if (ro->ro_rt == NULL) 291 rtalloc_ign(ro, RTF_PRCLONING); 292 if (ro->ro_rt == NULL) { 293 ipstat.ips_noroute++; 294 error = EHOSTUNREACH; 295 goto bad; 296 } 297 ia = ifatoia(ro->ro_rt->rt_ifa); 298 ifp = ro->ro_rt->rt_ifp; 299 ro->ro_rt->rt_use++; 300 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 301 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 302 if (ro->ro_rt->rt_flags & RTF_HOST) 303 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 304 else 305 isbroadcast = in_broadcast(dst->sin_addr, ifp); 306 } 307 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 308 struct in_multi *inm; 309 310 m->m_flags |= M_MCAST; 311 /* 312 * IP destination address is multicast. Make sure "dst" 313 * still points to the address in "ro". (It may have been 314 * changed to point to a gateway address, above.) 315 */ 316 dst = (struct sockaddr_in *)&ro->ro_dst; 317 /* 318 * See if the caller provided any multicast options 319 */ 320 if (imo != NULL) { 321 ip->ip_ttl = imo->imo_multicast_ttl; 322 if (imo->imo_multicast_vif != -1) 323 ip->ip_src.s_addr = 324 ip_mcast_src ? 325 ip_mcast_src(imo->imo_multicast_vif) : 326 INADDR_ANY; 327 } else 328 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 329 /* 330 * Confirm that the outgoing interface supports multicast. 331 */ 332 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 333 if (!(ifp->if_flags & IFF_MULTICAST)) { 334 ipstat.ips_noroute++; 335 error = ENETUNREACH; 336 goto bad; 337 } 338 } 339 /* 340 * If source address not specified yet, use address 341 * of outgoing interface. 342 */ 343 if (ip->ip_src.s_addr == INADDR_ANY) { 344 /* Interface may have no addresses. */ 345 if (ia != NULL) 346 ip->ip_src = IA_SIN(ia)->sin_addr; 347 } 348 349 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 350 if (inm != NULL && 351 (imo == NULL || imo->imo_multicast_loop)) { 352 /* 353 * If we belong to the destination multicast group 354 * on the outgoing interface, and the caller did not 355 * forbid loopback, loop back a copy. 356 */ 357 ip_mloopback(ifp, m, dst, hlen); 358 } 359 else { 360 /* 361 * If we are acting as a multicast router, perform 362 * multicast forwarding as if the packet had just 363 * arrived on the interface to which we are about 364 * to send. The multicast forwarding function 365 * recursively calls this function, using the 366 * IP_FORWARDING flag to prevent infinite recursion. 367 * 368 * Multicasts that are looped back by ip_mloopback(), 369 * above, will be forwarded by the ip_input() routine, 370 * if necessary. 371 */ 372 if (ip_mrouter && !(flags & IP_FORWARDING)) { 373 /* 374 * If rsvp daemon is not running, do not 375 * set ip_moptions. This ensures that the packet 376 * is multicast and not just sent down one link 377 * as prescribed by rsvpd. 378 */ 379 if (!rsvp_on) 380 imo = NULL; 381 if (ip_mforward && 382 ip_mforward(ip, ifp, m, imo) != 0) { 383 m_freem(m); 384 goto done; 385 } 386 } 387 } 388 389 /* 390 * Multicasts with a time-to-live of zero may be looped- 391 * back, above, but must not be transmitted on a network. 392 * Also, multicasts addressed to the loopback interface 393 * are not sent -- the above call to ip_mloopback() will 394 * loop back a copy if this host actually belongs to the 395 * destination group on the loopback interface. 396 */ 397 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 398 m_freem(m); 399 goto done; 400 } 401 402 goto sendit; 403 } 404 #ifndef notdef 405 /* 406 * If the source address is not specified yet, use the address 407 * of the outoing interface. In case, keep note we did that, so 408 * if the the firewall changes the next-hop causing the output 409 * interface to change, we can fix that. 410 */ 411 if (ip->ip_src.s_addr == INADDR_ANY) { 412 /* Interface may have no addresses. */ 413 if (ia != NULL) { 414 ip->ip_src = IA_SIN(ia)->sin_addr; 415 src_was_INADDR_ANY = 1; 416 } 417 } 418 #endif /* notdef */ 419 #ifdef ALTQ 420 /* 421 * Disable packet drop hack. 422 * Packetdrop should be done by queueing. 423 */ 424 #else /* !ALTQ */ 425 /* 426 * Verify that we have any chance at all of being able to queue 427 * the packet or packet fragments 428 */ 429 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 430 ifp->if_snd.ifq_maxlen) { 431 error = ENOBUFS; 432 ipstat.ips_odropped++; 433 goto bad; 434 } 435 #endif /* !ALTQ */ 436 437 /* 438 * Look for broadcast address and 439 * verify user is allowed to send 440 * such a packet. 441 */ 442 if (isbroadcast) { 443 if (!(ifp->if_flags & IFF_BROADCAST)) { 444 error = EADDRNOTAVAIL; 445 goto bad; 446 } 447 if (!(flags & IP_ALLOWBROADCAST)) { 448 error = EACCES; 449 goto bad; 450 } 451 /* don't allow broadcast messages to be fragmented */ 452 if (ip->ip_len > ifp->if_mtu) { 453 error = EMSGSIZE; 454 goto bad; 455 } 456 m->m_flags |= M_BCAST; 457 } else { 458 m->m_flags &= ~M_BCAST; 459 } 460 461 sendit: 462 #ifdef IPSEC 463 /* get SP for this packet */ 464 if (so == NULL) 465 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 466 else 467 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 468 469 if (sp == NULL) { 470 ipsecstat.out_inval++; 471 goto bad; 472 } 473 474 error = 0; 475 476 /* check policy */ 477 switch (sp->policy) { 478 case IPSEC_POLICY_DISCARD: 479 /* 480 * This packet is just discarded. 481 */ 482 ipsecstat.out_polvio++; 483 goto bad; 484 485 case IPSEC_POLICY_BYPASS: 486 case IPSEC_POLICY_NONE: 487 /* no need to do IPsec. */ 488 goto skip_ipsec; 489 490 case IPSEC_POLICY_IPSEC: 491 if (sp->req == NULL) { 492 /* acquire a policy */ 493 error = key_spdacquire(sp); 494 goto bad; 495 } 496 break; 497 498 case IPSEC_POLICY_ENTRUST: 499 default: 500 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 501 } 502 { 503 struct ipsec_output_state state; 504 bzero(&state, sizeof state); 505 state.m = m; 506 if (flags & IP_ROUTETOIF) { 507 state.ro = &iproute; 508 bzero(&iproute, sizeof iproute); 509 } else 510 state.ro = ro; 511 state.dst = (struct sockaddr *)dst; 512 513 ip->ip_sum = 0; 514 515 /* 516 * XXX 517 * delayed checksums are not currently compatible with IPsec 518 */ 519 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 520 in_delayed_cksum(m); 521 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 522 } 523 524 ip->ip_len = htons(ip->ip_len); 525 ip->ip_off = htons(ip->ip_off); 526 527 error = ipsec4_output(&state, sp, flags); 528 529 m = state.m; 530 if (flags & IP_ROUTETOIF) { 531 /* 532 * if we have tunnel mode SA, we may need to ignore 533 * IP_ROUTETOIF. 534 */ 535 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 536 flags &= ~IP_ROUTETOIF; 537 ro = state.ro; 538 } 539 } else 540 ro = state.ro; 541 dst = (struct sockaddr_in *)state.dst; 542 if (error) { 543 /* mbuf is already reclaimed in ipsec4_output. */ 544 m0 = NULL; 545 switch (error) { 546 case EHOSTUNREACH: 547 case ENETUNREACH: 548 case EMSGSIZE: 549 case ENOBUFS: 550 case ENOMEM: 551 break; 552 default: 553 kprintf("ip4_output (ipsec): error code %d\n", error); 554 /*fall through*/ 555 case ENOENT: 556 /* don't show these error codes to the user */ 557 error = 0; 558 break; 559 } 560 goto bad; 561 } 562 } 563 564 /* be sure to update variables that are affected by ipsec4_output() */ 565 ip = mtod(m, struct ip *); 566 #ifdef _IP_VHL 567 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 568 #else 569 hlen = ip->ip_hl << 2; 570 #endif 571 if (ro->ro_rt == NULL) { 572 if (!(flags & IP_ROUTETOIF)) { 573 kprintf("ip_output: " 574 "can't update route after IPsec processing\n"); 575 error = EHOSTUNREACH; /*XXX*/ 576 goto bad; 577 } 578 } else { 579 ia = ifatoia(ro->ro_rt->rt_ifa); 580 ifp = ro->ro_rt->rt_ifp; 581 } 582 583 /* make it flipped, again. */ 584 ip->ip_len = ntohs(ip->ip_len); 585 ip->ip_off = ntohs(ip->ip_off); 586 skip_ipsec: 587 #endif /*IPSEC*/ 588 #ifdef FAST_IPSEC 589 /* 590 * Check the security policy (SP) for the packet and, if 591 * required, do IPsec-related processing. There are two 592 * cases here; the first time a packet is sent through 593 * it will be untagged and handled by ipsec4_checkpolicy. 594 * If the packet is resubmitted to ip_output (e.g. after 595 * AH, ESP, etc. processing), there will be a tag to bypass 596 * the lookup and related policy checking. 597 */ 598 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 599 crit_enter(); 600 if (mtag != NULL) { 601 tdbi = (struct tdb_ident *)m_tag_data(mtag); 602 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 603 if (sp == NULL) 604 error = -EINVAL; /* force silent drop */ 605 m_tag_delete(m, mtag); 606 } else { 607 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 608 &error, inp); 609 } 610 /* 611 * There are four return cases: 612 * sp != NULL apply IPsec policy 613 * sp == NULL, error == 0 no IPsec handling needed 614 * sp == NULL, error == -EINVAL discard packet w/o error 615 * sp == NULL, error != 0 discard packet, report error 616 */ 617 if (sp != NULL) { 618 /* Loop detection, check if ipsec processing already done */ 619 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 620 for (mtag = m_tag_first(m); mtag != NULL; 621 mtag = m_tag_next(m, mtag)) { 622 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 623 continue; 624 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 625 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 626 continue; 627 /* 628 * Check if policy has an SA associated with it. 629 * This can happen when an SP has yet to acquire 630 * an SA; e.g. on first reference. If it occurs, 631 * then we let ipsec4_process_packet do its thing. 632 */ 633 if (sp->req->sav == NULL) 634 break; 635 tdbi = (struct tdb_ident *)m_tag_data(mtag); 636 if (tdbi->spi == sp->req->sav->spi && 637 tdbi->proto == sp->req->sav->sah->saidx.proto && 638 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 639 sizeof(union sockaddr_union)) == 0) { 640 /* 641 * No IPsec processing is needed, free 642 * reference to SP. 643 * 644 * NB: null pointer to avoid free at 645 * done: below. 646 */ 647 KEY_FREESP(&sp), sp = NULL; 648 crit_exit(); 649 goto spd_done; 650 } 651 } 652 653 /* 654 * Do delayed checksums now because we send before 655 * this is done in the normal processing path. 656 */ 657 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 658 in_delayed_cksum(m); 659 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 660 } 661 662 ip->ip_len = htons(ip->ip_len); 663 ip->ip_off = htons(ip->ip_off); 664 665 /* NB: callee frees mbuf */ 666 error = ipsec4_process_packet(m, sp->req, flags, 0); 667 /* 668 * Preserve KAME behaviour: ENOENT can be returned 669 * when an SA acquire is in progress. Don't propagate 670 * this to user-level; it confuses applications. 671 * 672 * XXX this will go away when the SADB is redone. 673 */ 674 if (error == ENOENT) 675 error = 0; 676 crit_exit(); 677 goto done; 678 } else { 679 crit_exit(); 680 681 if (error != 0) { 682 /* 683 * Hack: -EINVAL is used to signal that a packet 684 * should be silently discarded. This is typically 685 * because we asked key management for an SA and 686 * it was delayed (e.g. kicked up to IKE). 687 */ 688 if (error == -EINVAL) 689 error = 0; 690 goto bad; 691 } else { 692 /* No IPsec processing for this packet. */ 693 } 694 #ifdef notyet 695 /* 696 * If deferred crypto processing is needed, check that 697 * the interface supports it. 698 */ 699 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 700 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 701 /* notify IPsec to do its own crypto */ 702 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 703 error = EHOSTUNREACH; 704 goto bad; 705 } 706 #endif 707 } 708 spd_done: 709 #endif /* FAST_IPSEC */ 710 /* 711 * IpHack's section. 712 * - Xlate: translate packet's addr/port (NAT). 713 * - Firewall: deny/allow/etc. 714 * - Wrap: fake packet's addr/port <unimpl.> 715 * - Encapsulate: put it in another IP and send out. <unimp.> 716 */ 717 718 /* 719 * Run through list of hooks for output packets. 720 */ 721 if (pfil_has_hooks(&inet_pfil_hook)) { 722 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 723 if (error != 0 || m == NULL) 724 goto done; 725 ip = mtod(m, struct ip *); 726 } 727 728 /* 729 * Check with the firewall... 730 * but not if we are already being fwd'd from a firewall. 731 */ 732 if (fw_enable && IPFW_LOADED && !args.next_hop) { 733 struct sockaddr_in *old = dst; 734 735 args.m = m; 736 args.next_hop = dst; 737 args.oif = ifp; 738 off = ip_fw_chk_ptr(&args); 739 m = args.m; 740 dst = args.next_hop; 741 742 /* 743 * On return we must do the following: 744 * m == NULL -> drop the pkt (old interface, deprecated) 745 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 746 * 1<=off<= 0xffff -> DIVERT 747 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 748 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 749 * dst != old -> IPFIREWALL_FORWARD 750 * off==0, dst==old -> accept 751 * If some of the above modules are not compiled in, then 752 * we should't have to check the corresponding condition 753 * (because the ipfw control socket should not accept 754 * unsupported rules), but better play safe and drop 755 * packets in case of doubt. 756 */ 757 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 758 if (m) 759 m_freem(m); 760 error = EACCES; 761 goto done; 762 } 763 ip = mtod(m, struct ip *); 764 if (off == 0 && dst == old) /* common case */ 765 goto pass; 766 if (off & IP_FW_PORT_DYNT_FLAG) { 767 /* 768 * pass the pkt to dummynet. Need to include 769 * pipe number, m, ifp, ro, dst because these are 770 * not recomputed in the next pass. 771 * All other parameters have been already used and 772 * so they are not needed anymore. 773 * XXX note: if the ifp or ro entry are deleted 774 * while a pkt is in dummynet, we are in trouble! 775 */ 776 args.ro = ro; 777 args.dst = dst; 778 args.flags = flags; 779 780 error = 0; 781 ip_fw_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, &args); 782 goto done; 783 } 784 #ifdef IPDIVERT 785 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) { 786 struct mbuf *clone = NULL; 787 788 /* Clone packet if we're doing a 'tee' */ 789 if ((off & IP_FW_PORT_TEE_FLAG)) 790 clone = m_dup(m, MB_DONTWAIT); 791 792 /* 793 * XXX 794 * delayed checksums are not currently compatible 795 * with divert sockets. 796 */ 797 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 798 in_delayed_cksum(m); 799 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 800 } 801 802 /* Restore packet header fields to original values */ 803 ip->ip_len = htons(ip->ip_len); 804 ip->ip_off = htons(ip->ip_off); 805 806 /* Deliver packet to divert input routine */ 807 divert_packet(m, 0, off & 0xffff); 808 809 /* If 'tee', continue with original packet */ 810 if (clone != NULL) { 811 m = clone; 812 ip = mtod(m, struct ip *); 813 goto pass; 814 } 815 goto done; 816 } 817 #endif 818 819 /* IPFIREWALL_FORWARD */ 820 /* 821 * Check dst to make sure it is directly reachable on the 822 * interface we previously thought it was. 823 * If it isn't (which may be likely in some situations) we have 824 * to re-route it (ie, find a route for the next-hop and the 825 * associated interface) and set them here. This is nested 826 * forwarding which in most cases is undesirable, except where 827 * such control is nigh impossible. So we do it here. 828 * And I'm babbling. 829 */ 830 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 831 #if 0 832 /* 833 * XXX To improve readability, this block should be 834 * changed into a function call as below: 835 */ 836 error = ip_ipforward(&m, &dst, &ifp); 837 if (error) 838 goto bad; 839 if (m == NULL) /* ip_input consumed the mbuf */ 840 goto done; 841 #else 842 struct in_ifaddr *ia; 843 struct in_ifaddr_container *iac; 844 845 /* 846 * XXX sro_fwd below is static, and a pointer 847 * to it gets passed to routines downstream. 848 * This could have surprisingly bad results in 849 * practice, because its content is overwritten 850 * by subsequent packets. 851 */ 852 /* There must be a better way to do this next line... */ 853 static struct route sro_fwd; 854 struct route *ro_fwd = &sro_fwd; 855 856 #if 0 857 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 858 dst->sin_addr, "\n"); 859 #endif 860 861 /* 862 * We need to figure out if we have been forwarded 863 * to a local socket. If so, then we should somehow 864 * "loop back" to ip_input, and get directed to the 865 * PCB as if we had received this packet. This is 866 * because it may be dificult to identify the packets 867 * you want to forward until they are being output 868 * and have selected an interface. (e.g. locally 869 * initiated packets) If we used the loopback inteface, 870 * we would not be able to control what happens 871 * as the packet runs through ip_input() as 872 * it is done through a ISR. 873 */ 874 ia = NULL; 875 LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr), 876 ia_hash) { 877 /* 878 * If the addr to forward to is one 879 * of ours, we pretend to 880 * be the destination for this packet. 881 */ 882 if (IA_SIN(iac->ia)->sin_addr.s_addr == 883 dst->sin_addr.s_addr) { 884 ia = iac->ia; 885 break; 886 } 887 } 888 if (ia != NULL) { /* tell ip_input "dont filter" */ 889 struct m_hdr tag; 890 891 tag.mh_type = MT_TAG; 892 tag.mh_flags = PACKET_TAG_IPFORWARD; 893 tag.mh_data = (caddr_t)args.next_hop; 894 tag.mh_next = m; 895 896 if (m->m_pkthdr.rcvif == NULL) 897 m->m_pkthdr.rcvif = ifunit("lo0"); 898 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 899 m->m_pkthdr.csum_flags |= 900 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 901 m->m_pkthdr.csum_data = 0xffff; 902 } 903 m->m_pkthdr.csum_flags |= 904 CSUM_IP_CHECKED | CSUM_IP_VALID; 905 ip->ip_len = htons(ip->ip_len); 906 ip->ip_off = htons(ip->ip_off); 907 ip_input((struct mbuf *)&tag); 908 goto done; 909 } 910 /* Some of the logic for this was nicked from above. 911 * 912 * This rewrites the cached route in a local PCB. 913 * Is this what we want to do? 914 */ 915 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst); 916 ro_fwd->ro_rt = NULL; 917 918 rtalloc_ign(ro_fwd, RTF_PRCLONING); 919 if (ro_fwd->ro_rt == NULL) { 920 ipstat.ips_noroute++; 921 error = EHOSTUNREACH; 922 goto bad; 923 } 924 925 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 926 ifp = ro_fwd->ro_rt->rt_ifp; 927 ro_fwd->ro_rt->rt_use++; 928 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 929 dst = (struct sockaddr_in *) 930 ro_fwd->ro_rt->rt_gateway; 931 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 932 isbroadcast = 933 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 934 else 935 isbroadcast = in_broadcast(dst->sin_addr, ifp); 936 if (ro->ro_rt != NULL) 937 rtfree(ro->ro_rt); 938 ro->ro_rt = ro_fwd->ro_rt; 939 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 940 941 #endif /* ... block to be put into a function */ 942 /* 943 * If we added a default src ip earlier, 944 * which would have been gotten from the-then 945 * interface, do it again, from the new one. 946 */ 947 if (src_was_INADDR_ANY) 948 ip->ip_src = IA_SIN(ia)->sin_addr; 949 goto pass ; 950 } 951 952 /* 953 * if we get here, none of the above matches, and 954 * we have to drop the pkt 955 */ 956 m_freem(m); 957 error = EACCES; /* not sure this is the right error msg */ 958 goto done; 959 } 960 961 pass: 962 /* 127/8 must not appear on wire - RFC1122. */ 963 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 964 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 965 if (!(ifp->if_flags & IFF_LOOPBACK)) { 966 ipstat.ips_badaddr++; 967 error = EADDRNOTAVAIL; 968 goto bad; 969 } 970 } 971 972 m->m_pkthdr.csum_flags |= CSUM_IP; 973 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 974 if (sw_csum & CSUM_DELAY_DATA) { 975 in_delayed_cksum(m); 976 sw_csum &= ~CSUM_DELAY_DATA; 977 } 978 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 979 980 /* 981 * If small enough for interface, or the interface will take 982 * care of the fragmentation for us, can just send directly. 983 */ 984 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 985 !(ip->ip_off & IP_DF))) { 986 ip->ip_len = htons(ip->ip_len); 987 ip->ip_off = htons(ip->ip_off); 988 ip->ip_sum = 0; 989 if (sw_csum & CSUM_DELAY_IP) { 990 if (ip->ip_vhl == IP_VHL_BORING) { 991 ip->ip_sum = in_cksum_hdr(ip); 992 } else { 993 ip->ip_sum = in_cksum(m, hlen); 994 } 995 } 996 997 /* Record statistics for this interface address. */ 998 if (!(flags & IP_FORWARDING) && ia) { 999 ia->ia_ifa.if_opackets++; 1000 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1001 } 1002 1003 #ifdef IPSEC 1004 /* clean ipsec history once it goes out of the node */ 1005 ipsec_delaux(m); 1006 #endif 1007 1008 #ifdef MBUF_STRESS_TEST 1009 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 1010 struct mbuf *m1, *m2; 1011 int length, tmp; 1012 1013 tmp = length = m->m_pkthdr.len; 1014 1015 while ((length -= mbuf_frag_size) >= 1) { 1016 m1 = m_split(m, length, MB_DONTWAIT); 1017 if (m1 == NULL) 1018 break; 1019 m2 = m; 1020 while (m2->m_next != NULL) 1021 m2 = m2->m_next; 1022 m2->m_next = m1; 1023 } 1024 m->m_pkthdr.len = tmp; 1025 } 1026 #endif 1027 1028 #ifdef MPLS 1029 struct rtentry *send_route = ro->ro_rt; /* copy-in/copy-out parameter */ 1030 1031 if (!mpls_output_process(ifp, m, &dst, send_route)) 1032 goto done; 1033 #endif 1034 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 1035 ro->ro_rt); 1036 goto done; 1037 } 1038 1039 if (ip->ip_off & IP_DF) { 1040 error = EMSGSIZE; 1041 /* 1042 * This case can happen if the user changed the MTU 1043 * of an interface after enabling IP on it. Because 1044 * most netifs don't keep track of routes pointing to 1045 * them, there is no way for one to update all its 1046 * routes when the MTU is changed. 1047 */ 1048 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1049 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1050 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1051 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1052 } 1053 ipstat.ips_cantfrag++; 1054 goto bad; 1055 } 1056 1057 /* 1058 * Too large for interface; fragment if possible. If successful, 1059 * on return, m will point to a list of packets to be sent. 1060 */ 1061 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1062 if (error) 1063 goto bad; 1064 for (; m; m = m0) { 1065 m0 = m->m_nextpkt; 1066 m->m_nextpkt = NULL; 1067 #ifdef IPSEC 1068 /* clean ipsec history once it goes out of the node */ 1069 ipsec_delaux(m); 1070 #endif 1071 if (error == 0) { 1072 /* Record statistics for this interface address. */ 1073 if (ia != NULL) { 1074 ia->ia_ifa.if_opackets++; 1075 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1076 } 1077 #ifdef MPLS 1078 struct rtentry *send_route = ro->ro_rt; /* copy-in/copy-out parameter */ 1079 1080 if (!mpls_output_process(ifp, m, &dst, send_route)) 1081 goto done; 1082 #endif 1083 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 1084 ro->ro_rt); 1085 } else { 1086 m_freem(m); 1087 } 1088 } 1089 1090 if (error == 0) 1091 ipstat.ips_fragmented++; 1092 1093 done: 1094 if (ro == &iproute && ro->ro_rt != NULL) { 1095 RTFREE(ro->ro_rt); 1096 ro->ro_rt = NULL; 1097 } 1098 #ifdef IPSEC 1099 if (sp != NULL) { 1100 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1101 kprintf("DP ip_output call free SP:%p\n", sp)); 1102 key_freesp(sp); 1103 } 1104 #endif 1105 #ifdef FAST_IPSEC 1106 if (sp != NULL) 1107 KEY_FREESP(&sp); 1108 #endif 1109 if (dn_mtag != NULL) 1110 m_tag_free(dn_mtag); 1111 1112 return (error); 1113 bad: 1114 m_freem(m); 1115 goto done; 1116 } 1117 1118 /* 1119 * Create a chain of fragments which fit the given mtu. m_frag points to the 1120 * mbuf to be fragmented; on return it points to the chain with the fragments. 1121 * Return 0 if no error. If error, m_frag may contain a partially built 1122 * chain of fragments that should be freed by the caller. 1123 * 1124 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1125 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1126 */ 1127 int 1128 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1129 u_long if_hwassist_flags, int sw_csum) 1130 { 1131 int error = 0; 1132 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1133 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1134 int off; 1135 struct mbuf *m0 = *m_frag; /* the original packet */ 1136 int firstlen; 1137 struct mbuf **mnext; 1138 int nfrags; 1139 1140 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1141 ipstat.ips_cantfrag++; 1142 return EMSGSIZE; 1143 } 1144 1145 /* 1146 * Must be able to put at least 8 bytes per fragment. 1147 */ 1148 if (len < 8) 1149 return EMSGSIZE; 1150 1151 /* 1152 * If the interface will not calculate checksums on 1153 * fragmented packets, then do it here. 1154 */ 1155 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1156 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1157 in_delayed_cksum(m0); 1158 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1159 } 1160 1161 if (len > PAGE_SIZE) { 1162 /* 1163 * Fragment large datagrams such that each segment 1164 * contains a multiple of PAGE_SIZE amount of data, 1165 * plus headers. This enables a receiver to perform 1166 * page-flipping zero-copy optimizations. 1167 * 1168 * XXX When does this help given that sender and receiver 1169 * could have different page sizes, and also mtu could 1170 * be less than the receiver's page size ? 1171 */ 1172 int newlen; 1173 struct mbuf *m; 1174 1175 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1176 off += m->m_len; 1177 1178 /* 1179 * firstlen (off - hlen) must be aligned on an 1180 * 8-byte boundary 1181 */ 1182 if (off < hlen) 1183 goto smart_frag_failure; 1184 off = ((off - hlen) & ~7) + hlen; 1185 newlen = (~PAGE_MASK) & mtu; 1186 if ((newlen + sizeof(struct ip)) > mtu) { 1187 /* we failed, go back the default */ 1188 smart_frag_failure: 1189 newlen = len; 1190 off = hlen + len; 1191 } 1192 len = newlen; 1193 1194 } else { 1195 off = hlen + len; 1196 } 1197 1198 firstlen = off - hlen; 1199 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1200 1201 /* 1202 * Loop through length of segment after first fragment, 1203 * make new header and copy data of each part and link onto chain. 1204 * Here, m0 is the original packet, m is the fragment being created. 1205 * The fragments are linked off the m_nextpkt of the original 1206 * packet, which after processing serves as the first fragment. 1207 */ 1208 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1209 struct ip *mhip; /* ip header on the fragment */ 1210 struct mbuf *m; 1211 int mhlen = sizeof(struct ip); 1212 1213 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1214 if (m == NULL) { 1215 error = ENOBUFS; 1216 ipstat.ips_odropped++; 1217 goto done; 1218 } 1219 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1220 /* 1221 * In the first mbuf, leave room for the link header, then 1222 * copy the original IP header including options. The payload 1223 * goes into an additional mbuf chain returned by m_copy(). 1224 */ 1225 m->m_data += max_linkhdr; 1226 mhip = mtod(m, struct ip *); 1227 *mhip = *ip; 1228 if (hlen > sizeof(struct ip)) { 1229 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1230 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1231 } 1232 m->m_len = mhlen; 1233 /* XXX do we need to add ip->ip_off below ? */ 1234 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1235 if (off + len >= ip->ip_len) { /* last fragment */ 1236 len = ip->ip_len - off; 1237 m->m_flags |= M_LASTFRAG; 1238 } else 1239 mhip->ip_off |= IP_MF; 1240 mhip->ip_len = htons((u_short)(len + mhlen)); 1241 m->m_next = m_copy(m0, off, len); 1242 if (m->m_next == NULL) { /* copy failed */ 1243 m_free(m); 1244 error = ENOBUFS; /* ??? */ 1245 ipstat.ips_odropped++; 1246 goto done; 1247 } 1248 m->m_pkthdr.len = mhlen + len; 1249 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1250 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1251 mhip->ip_off = htons(mhip->ip_off); 1252 mhip->ip_sum = 0; 1253 if (sw_csum & CSUM_DELAY_IP) 1254 mhip->ip_sum = in_cksum(m, mhlen); 1255 *mnext = m; 1256 mnext = &m->m_nextpkt; 1257 } 1258 ipstat.ips_ofragments += nfrags; 1259 1260 /* set first marker for fragment chain */ 1261 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1262 m0->m_pkthdr.csum_data = nfrags; 1263 1264 /* 1265 * Update first fragment by trimming what's been copied out 1266 * and updating header. 1267 */ 1268 m_adj(m0, hlen + firstlen - ip->ip_len); 1269 m0->m_pkthdr.len = hlen + firstlen; 1270 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1271 ip->ip_off |= IP_MF; 1272 ip->ip_off = htons(ip->ip_off); 1273 ip->ip_sum = 0; 1274 if (sw_csum & CSUM_DELAY_IP) 1275 ip->ip_sum = in_cksum(m0, hlen); 1276 1277 done: 1278 *m_frag = m0; 1279 return error; 1280 } 1281 1282 void 1283 in_delayed_cksum(struct mbuf *m) 1284 { 1285 struct ip *ip; 1286 u_short csum, offset; 1287 1288 ip = mtod(m, struct ip *); 1289 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1290 csum = in_cksum_skip(m, ip->ip_len, offset); 1291 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1292 csum = 0xffff; 1293 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1294 1295 if (offset + sizeof(u_short) > m->m_len) { 1296 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1297 m->m_len, offset, ip->ip_p); 1298 /* 1299 * XXX 1300 * this shouldn't happen, but if it does, the 1301 * correct behavior may be to insert the checksum 1302 * in the existing chain instead of rearranging it. 1303 */ 1304 m = m_pullup(m, offset + sizeof(u_short)); 1305 } 1306 *(u_short *)(m->m_data + offset) = csum; 1307 } 1308 1309 /* 1310 * Insert IP options into preformed packet. 1311 * Adjust IP destination as required for IP source routing, 1312 * as indicated by a non-zero in_addr at the start of the options. 1313 * 1314 * XXX This routine assumes that the packet has no options in place. 1315 */ 1316 static struct mbuf * 1317 ip_insertoptions(struct mbuf *m, struct mbuf *opt, 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, MB_DONTWAIT, MT_HEADER); 1333 if (n == NULL) { 1334 *phlen = 0; 1335 return (m); 1336 } 1337 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 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 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(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(struct ip *ip, struct ip *jp) 1366 { 1367 u_char *cp, *dp; 1368 int opt, optlen, cnt; 1369 1370 cp = (u_char *)(ip + 1); 1371 dp = (u_char *)(jp + 1); 1372 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1373 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1374 opt = cp[0]; 1375 if (opt == IPOPT_EOL) 1376 break; 1377 if (opt == IPOPT_NOP) { 1378 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1379 *dp++ = IPOPT_NOP; 1380 optlen = 1; 1381 continue; 1382 } 1383 1384 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1385 ("ip_optcopy: malformed ipv4 option")); 1386 optlen = cp[IPOPT_OLEN]; 1387 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1388 ("ip_optcopy: malformed ipv4 option")); 1389 1390 /* bogus lengths should have been caught by ip_dooptions */ 1391 if (optlen > cnt) 1392 optlen = cnt; 1393 if (IPOPT_COPIED(opt)) { 1394 bcopy(cp, dp, optlen); 1395 dp += optlen; 1396 } 1397 } 1398 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1399 *dp++ = IPOPT_EOL; 1400 return (optlen); 1401 } 1402 1403 /* 1404 * IP socket option processing. 1405 */ 1406 int 1407 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1408 { 1409 struct inpcb *inp = so->so_pcb; 1410 int error, optval; 1411 1412 error = optval = 0; 1413 if (sopt->sopt_level != IPPROTO_IP) { 1414 return (EINVAL); 1415 } 1416 1417 switch (sopt->sopt_dir) { 1418 case SOPT_SET: 1419 switch (sopt->sopt_name) { 1420 case IP_OPTIONS: 1421 #ifdef notyet 1422 case IP_RETOPTS: 1423 #endif 1424 { 1425 struct mbuf *m; 1426 if (sopt->sopt_valsize > MLEN) { 1427 error = EMSGSIZE; 1428 break; 1429 } 1430 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1431 if (m == NULL) { 1432 error = ENOBUFS; 1433 break; 1434 } 1435 m->m_len = sopt->sopt_valsize; 1436 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len, 1437 m->m_len); 1438 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1439 m)); 1440 } 1441 1442 case IP_TOS: 1443 case IP_TTL: 1444 case IP_MINTTL: 1445 case IP_RECVOPTS: 1446 case IP_RECVRETOPTS: 1447 case IP_RECVDSTADDR: 1448 case IP_RECVIF: 1449 case IP_RECVTTL: 1450 case IP_FAITH: 1451 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1452 sizeof optval); 1453 if (error) 1454 break; 1455 switch (sopt->sopt_name) { 1456 case IP_TOS: 1457 inp->inp_ip_tos = optval; 1458 break; 1459 1460 case IP_TTL: 1461 inp->inp_ip_ttl = optval; 1462 break; 1463 case IP_MINTTL: 1464 if (optval > 0 && optval <= MAXTTL) 1465 inp->inp_ip_minttl = optval; 1466 else 1467 error = EINVAL; 1468 break; 1469 #define OPTSET(bit) \ 1470 if (optval) \ 1471 inp->inp_flags |= bit; \ 1472 else \ 1473 inp->inp_flags &= ~bit; 1474 1475 case IP_RECVOPTS: 1476 OPTSET(INP_RECVOPTS); 1477 break; 1478 1479 case IP_RECVRETOPTS: 1480 OPTSET(INP_RECVRETOPTS); 1481 break; 1482 1483 case IP_RECVDSTADDR: 1484 OPTSET(INP_RECVDSTADDR); 1485 break; 1486 1487 case IP_RECVIF: 1488 OPTSET(INP_RECVIF); 1489 break; 1490 1491 case IP_RECVTTL: 1492 OPTSET(INP_RECVTTL); 1493 break; 1494 1495 case IP_FAITH: 1496 OPTSET(INP_FAITH); 1497 break; 1498 } 1499 break; 1500 #undef OPTSET 1501 1502 case IP_MULTICAST_IF: 1503 case IP_MULTICAST_VIF: 1504 case IP_MULTICAST_TTL: 1505 case IP_MULTICAST_LOOP: 1506 case IP_ADD_MEMBERSHIP: 1507 case IP_DROP_MEMBERSHIP: 1508 error = ip_setmoptions(sopt, &inp->inp_moptions); 1509 break; 1510 1511 case IP_PORTRANGE: 1512 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1513 sizeof optval); 1514 if (error) 1515 break; 1516 1517 switch (optval) { 1518 case IP_PORTRANGE_DEFAULT: 1519 inp->inp_flags &= ~(INP_LOWPORT); 1520 inp->inp_flags &= ~(INP_HIGHPORT); 1521 break; 1522 1523 case IP_PORTRANGE_HIGH: 1524 inp->inp_flags &= ~(INP_LOWPORT); 1525 inp->inp_flags |= INP_HIGHPORT; 1526 break; 1527 1528 case IP_PORTRANGE_LOW: 1529 inp->inp_flags &= ~(INP_HIGHPORT); 1530 inp->inp_flags |= INP_LOWPORT; 1531 break; 1532 1533 default: 1534 error = EINVAL; 1535 break; 1536 } 1537 break; 1538 1539 #if defined(IPSEC) || defined(FAST_IPSEC) 1540 case IP_IPSEC_POLICY: 1541 { 1542 caddr_t req; 1543 size_t len = 0; 1544 int priv; 1545 struct mbuf *m; 1546 int optname; 1547 1548 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1549 break; 1550 soopt_to_mbuf(sopt, m); 1551 priv = (sopt->sopt_td != NULL && 1552 suser(sopt->sopt_td) != 0) ? 0 : 1; 1553 req = mtod(m, caddr_t); 1554 len = m->m_len; 1555 optname = sopt->sopt_name; 1556 error = ipsec4_set_policy(inp, optname, req, len, priv); 1557 m_freem(m); 1558 break; 1559 } 1560 #endif /*IPSEC*/ 1561 1562 default: 1563 error = ENOPROTOOPT; 1564 break; 1565 } 1566 break; 1567 1568 case SOPT_GET: 1569 switch (sopt->sopt_name) { 1570 case IP_OPTIONS: 1571 case IP_RETOPTS: 1572 if (inp->inp_options) 1573 soopt_from_kbuf(sopt, mtod(inp->inp_options, 1574 char *), 1575 inp->inp_options->m_len); 1576 else 1577 sopt->sopt_valsize = 0; 1578 break; 1579 1580 case IP_TOS: 1581 case IP_TTL: 1582 case IP_MINTTL: 1583 case IP_RECVOPTS: 1584 case IP_RECVRETOPTS: 1585 case IP_RECVDSTADDR: 1586 case IP_RECVTTL: 1587 case IP_RECVIF: 1588 case IP_PORTRANGE: 1589 case IP_FAITH: 1590 switch (sopt->sopt_name) { 1591 1592 case IP_TOS: 1593 optval = inp->inp_ip_tos; 1594 break; 1595 1596 case IP_TTL: 1597 optval = inp->inp_ip_ttl; 1598 break; 1599 case IP_MINTTL: 1600 optval = inp->inp_ip_minttl; 1601 break; 1602 1603 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1604 1605 case IP_RECVOPTS: 1606 optval = OPTBIT(INP_RECVOPTS); 1607 break; 1608 1609 case IP_RECVRETOPTS: 1610 optval = OPTBIT(INP_RECVRETOPTS); 1611 break; 1612 1613 case IP_RECVDSTADDR: 1614 optval = OPTBIT(INP_RECVDSTADDR); 1615 break; 1616 1617 case IP_RECVTTL: 1618 optval = OPTBIT(INP_RECVTTL); 1619 break; 1620 1621 case IP_RECVIF: 1622 optval = OPTBIT(INP_RECVIF); 1623 break; 1624 1625 case IP_PORTRANGE: 1626 if (inp->inp_flags & INP_HIGHPORT) 1627 optval = IP_PORTRANGE_HIGH; 1628 else if (inp->inp_flags & INP_LOWPORT) 1629 optval = IP_PORTRANGE_LOW; 1630 else 1631 optval = 0; 1632 break; 1633 1634 case IP_FAITH: 1635 optval = OPTBIT(INP_FAITH); 1636 break; 1637 } 1638 soopt_from_kbuf(sopt, &optval, sizeof optval); 1639 break; 1640 1641 case IP_MULTICAST_IF: 1642 case IP_MULTICAST_VIF: 1643 case IP_MULTICAST_TTL: 1644 case IP_MULTICAST_LOOP: 1645 case IP_ADD_MEMBERSHIP: 1646 case IP_DROP_MEMBERSHIP: 1647 error = ip_getmoptions(sopt, inp->inp_moptions); 1648 break; 1649 1650 #if defined(IPSEC) || defined(FAST_IPSEC) 1651 case IP_IPSEC_POLICY: 1652 { 1653 struct mbuf *m = NULL; 1654 caddr_t req = NULL; 1655 size_t len = 0; 1656 1657 if (m != NULL) { 1658 req = mtod(m, caddr_t); 1659 len = m->m_len; 1660 } 1661 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1662 if (error == 0) 1663 error = soopt_from_mbuf(sopt, m); /* XXX */ 1664 if (error == 0) 1665 m_freem(m); 1666 break; 1667 } 1668 #endif /*IPSEC*/ 1669 1670 default: 1671 error = ENOPROTOOPT; 1672 break; 1673 } 1674 break; 1675 } 1676 return (error); 1677 } 1678 1679 /* 1680 * Set up IP options in pcb for insertion in output packets. 1681 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1682 * with destination address if source routed. 1683 */ 1684 static int 1685 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1686 { 1687 int cnt, optlen; 1688 u_char *cp; 1689 u_char opt; 1690 1691 /* turn off any old options */ 1692 if (*pcbopt) 1693 m_free(*pcbopt); 1694 *pcbopt = 0; 1695 if (m == NULL || m->m_len == 0) { 1696 /* 1697 * Only turning off any previous options. 1698 */ 1699 if (m != NULL) 1700 m_free(m); 1701 return (0); 1702 } 1703 1704 if (m->m_len % sizeof(int32_t)) 1705 goto bad; 1706 /* 1707 * IP first-hop destination address will be stored before 1708 * actual options; move other options back 1709 * and clear it when none present. 1710 */ 1711 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1712 goto bad; 1713 cnt = m->m_len; 1714 m->m_len += sizeof(struct in_addr); 1715 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1716 ovbcopy(mtod(m, caddr_t), cp, cnt); 1717 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1718 1719 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1720 opt = cp[IPOPT_OPTVAL]; 1721 if (opt == IPOPT_EOL) 1722 break; 1723 if (opt == IPOPT_NOP) 1724 optlen = 1; 1725 else { 1726 if (cnt < IPOPT_OLEN + sizeof *cp) 1727 goto bad; 1728 optlen = cp[IPOPT_OLEN]; 1729 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1730 goto bad; 1731 } 1732 switch (opt) { 1733 1734 default: 1735 break; 1736 1737 case IPOPT_LSRR: 1738 case IPOPT_SSRR: 1739 /* 1740 * user process specifies route as: 1741 * ->A->B->C->D 1742 * D must be our final destination (but we can't 1743 * check that since we may not have connected yet). 1744 * A is first hop destination, which doesn't appear in 1745 * actual IP option, but is stored before the options. 1746 */ 1747 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1748 goto bad; 1749 m->m_len -= sizeof(struct in_addr); 1750 cnt -= sizeof(struct in_addr); 1751 optlen -= sizeof(struct in_addr); 1752 cp[IPOPT_OLEN] = optlen; 1753 /* 1754 * Move first hop before start of options. 1755 */ 1756 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1757 sizeof(struct in_addr)); 1758 /* 1759 * Then copy rest of options back 1760 * to close up the deleted entry. 1761 */ 1762 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1763 &cp[IPOPT_OFFSET+1], 1764 cnt - (IPOPT_MINOFF - 1)); 1765 break; 1766 } 1767 } 1768 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1769 goto bad; 1770 *pcbopt = m; 1771 return (0); 1772 1773 bad: 1774 m_free(m); 1775 return (EINVAL); 1776 } 1777 1778 /* 1779 * XXX 1780 * The whole multicast option thing needs to be re-thought. 1781 * Several of these options are equally applicable to non-multicast 1782 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1783 * standard option (IP_TTL). 1784 */ 1785 1786 /* 1787 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1788 */ 1789 static struct ifnet * 1790 ip_multicast_if(struct in_addr *a, int *ifindexp) 1791 { 1792 int ifindex; 1793 struct ifnet *ifp; 1794 1795 if (ifindexp) 1796 *ifindexp = 0; 1797 if (ntohl(a->s_addr) >> 24 == 0) { 1798 ifindex = ntohl(a->s_addr) & 0xffffff; 1799 if (ifindex < 0 || if_index < ifindex) 1800 return NULL; 1801 ifp = ifindex2ifnet[ifindex]; 1802 if (ifindexp) 1803 *ifindexp = ifindex; 1804 } else { 1805 ifp = INADDR_TO_IFP(a); 1806 } 1807 return ifp; 1808 } 1809 1810 /* 1811 * Set the IP multicast options in response to user setsockopt(). 1812 */ 1813 static int 1814 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1815 { 1816 int error = 0; 1817 int i; 1818 struct in_addr addr; 1819 struct ip_mreq mreq; 1820 struct ifnet *ifp; 1821 struct ip_moptions *imo = *imop; 1822 int ifindex; 1823 1824 if (imo == NULL) { 1825 /* 1826 * No multicast option buffer attached to the pcb; 1827 * allocate one and initialize to default values. 1828 */ 1829 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1830 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 switch (sopt->sopt_name) { 1840 /* store an index number for the vif you wanna use in the send */ 1841 case IP_MULTICAST_VIF: 1842 if (legal_vif_num == 0) { 1843 error = EOPNOTSUPP; 1844 break; 1845 } 1846 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i); 1847 if (error) 1848 break; 1849 if (!legal_vif_num(i) && (i != -1)) { 1850 error = EINVAL; 1851 break; 1852 } 1853 imo->imo_multicast_vif = i; 1854 break; 1855 1856 case IP_MULTICAST_IF: 1857 /* 1858 * Select the interface for outgoing multicast packets. 1859 */ 1860 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr); 1861 if (error) 1862 break; 1863 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 crit_enter(); 1879 ifp = ip_multicast_if(&addr, &ifindex); 1880 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1881 crit_exit(); 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 crit_exit(); 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 = soopt_to_kbuf(sopt, &ttl, 1, 1); 1903 if (error) 1904 break; 1905 imo->imo_multicast_ttl = ttl; 1906 } else { 1907 u_int ttl; 1908 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl); 1909 if (error) 1910 break; 1911 if (ttl > 255) 1912 error = EINVAL; 1913 else 1914 imo->imo_multicast_ttl = ttl; 1915 } 1916 break; 1917 1918 case IP_MULTICAST_LOOP: 1919 /* 1920 * Set the loopback flag for outgoing multicast packets. 1921 * Must be zero or one. The original multicast API required a 1922 * char argument, which is inconsistent with the rest 1923 * of the socket API. We allow either a char or an int. 1924 */ 1925 if (sopt->sopt_valsize == 1) { 1926 u_char loop; 1927 1928 error = soopt_to_kbuf(sopt, &loop, 1, 1); 1929 if (error) 1930 break; 1931 imo->imo_multicast_loop = !!loop; 1932 } else { 1933 u_int loop; 1934 1935 error = soopt_to_kbuf(sopt, &loop, sizeof loop, 1936 sizeof loop); 1937 if (error) 1938 break; 1939 imo->imo_multicast_loop = !!loop; 1940 } 1941 break; 1942 1943 case IP_ADD_MEMBERSHIP: 1944 /* 1945 * Add a multicast group membership. 1946 * Group must be a valid IP multicast address. 1947 */ 1948 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1949 if (error) 1950 break; 1951 1952 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1953 error = EINVAL; 1954 break; 1955 } 1956 crit_enter(); 1957 /* 1958 * If no interface address was provided, use the interface of 1959 * the route to the given multicast address. 1960 */ 1961 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1962 struct sockaddr_in dst; 1963 struct rtentry *rt; 1964 1965 bzero(&dst, sizeof(struct sockaddr_in)); 1966 dst.sin_len = sizeof(struct sockaddr_in); 1967 dst.sin_family = AF_INET; 1968 dst.sin_addr = mreq.imr_multiaddr; 1969 rt = rtlookup((struct sockaddr *)&dst); 1970 if (rt == NULL) { 1971 error = EADDRNOTAVAIL; 1972 crit_exit(); 1973 break; 1974 } 1975 --rt->rt_refcnt; 1976 ifp = rt->rt_ifp; 1977 } else { 1978 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1979 } 1980 1981 /* 1982 * See if we found an interface, and confirm that it 1983 * supports multicast. 1984 */ 1985 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1986 error = EADDRNOTAVAIL; 1987 crit_exit(); 1988 break; 1989 } 1990 /* 1991 * See if the membership already exists or if all the 1992 * membership slots are full. 1993 */ 1994 for (i = 0; i < imo->imo_num_memberships; ++i) { 1995 if (imo->imo_membership[i]->inm_ifp == ifp && 1996 imo->imo_membership[i]->inm_addr.s_addr 1997 == mreq.imr_multiaddr.s_addr) 1998 break; 1999 } 2000 if (i < imo->imo_num_memberships) { 2001 error = EADDRINUSE; 2002 crit_exit(); 2003 break; 2004 } 2005 if (i == IP_MAX_MEMBERSHIPS) { 2006 error = ETOOMANYREFS; 2007 crit_exit(); 2008 break; 2009 } 2010 /* 2011 * Everything looks good; add a new record to the multicast 2012 * address list for the given interface. 2013 */ 2014 if ((imo->imo_membership[i] = 2015 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 2016 error = ENOBUFS; 2017 crit_exit(); 2018 break; 2019 } 2020 ++imo->imo_num_memberships; 2021 crit_exit(); 2022 break; 2023 2024 case IP_DROP_MEMBERSHIP: 2025 /* 2026 * Drop a multicast group membership. 2027 * Group must be a valid IP multicast address. 2028 */ 2029 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 2030 if (error) 2031 break; 2032 2033 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2034 error = EINVAL; 2035 break; 2036 } 2037 2038 crit_enter(); 2039 /* 2040 * If an interface address was specified, get a pointer 2041 * to its ifnet structure. 2042 */ 2043 if (mreq.imr_interface.s_addr == INADDR_ANY) 2044 ifp = NULL; 2045 else { 2046 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2047 if (ifp == NULL) { 2048 error = EADDRNOTAVAIL; 2049 crit_exit(); 2050 break; 2051 } 2052 } 2053 /* 2054 * Find the membership in the membership array. 2055 */ 2056 for (i = 0; i < imo->imo_num_memberships; ++i) { 2057 if ((ifp == NULL || 2058 imo->imo_membership[i]->inm_ifp == ifp) && 2059 imo->imo_membership[i]->inm_addr.s_addr == 2060 mreq.imr_multiaddr.s_addr) 2061 break; 2062 } 2063 if (i == imo->imo_num_memberships) { 2064 error = EADDRNOTAVAIL; 2065 crit_exit(); 2066 break; 2067 } 2068 /* 2069 * Give up the multicast address record to which the 2070 * membership points. 2071 */ 2072 in_delmulti(imo->imo_membership[i]); 2073 /* 2074 * Remove the gap in the membership array. 2075 */ 2076 for (++i; i < imo->imo_num_memberships; ++i) 2077 imo->imo_membership[i-1] = imo->imo_membership[i]; 2078 --imo->imo_num_memberships; 2079 crit_exit(); 2080 break; 2081 2082 default: 2083 error = EOPNOTSUPP; 2084 break; 2085 } 2086 2087 /* 2088 * If all options have default values, no need to keep the mbuf. 2089 */ 2090 if (imo->imo_multicast_ifp == NULL && 2091 imo->imo_multicast_vif == -1 && 2092 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2093 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2094 imo->imo_num_memberships == 0) { 2095 kfree(*imop, M_IPMOPTS); 2096 *imop = NULL; 2097 } 2098 2099 return (error); 2100 } 2101 2102 /* 2103 * Return the IP multicast options in response to user getsockopt(). 2104 */ 2105 static int 2106 ip_getmoptions(struct sockopt *sopt, 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 soopt_from_kbuf(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 ia = IFP_TO_IA(imo->imo_multicast_ifp); 2131 addr.s_addr = (ia == NULL) ? INADDR_ANY 2132 : IA_SIN(ia)->sin_addr.s_addr; 2133 } 2134 soopt_from_kbuf(sopt, &addr, sizeof addr); 2135 break; 2136 2137 case IP_MULTICAST_TTL: 2138 if (imo == NULL) 2139 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2140 else 2141 optval = coptval = imo->imo_multicast_ttl; 2142 if (sopt->sopt_valsize == 1) 2143 soopt_from_kbuf(sopt, &coptval, 1); 2144 else 2145 soopt_from_kbuf(sopt, &optval, sizeof optval); 2146 break; 2147 2148 case IP_MULTICAST_LOOP: 2149 if (imo == NULL) 2150 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2151 else 2152 optval = coptval = imo->imo_multicast_loop; 2153 if (sopt->sopt_valsize == 1) 2154 soopt_from_kbuf(sopt, &coptval, 1); 2155 else 2156 soopt_from_kbuf(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(struct ip_moptions *imo) 2171 { 2172 int i; 2173 2174 if (imo != NULL) { 2175 for (i = 0; i < imo->imo_num_memberships; ++i) 2176 in_delmulti(imo->imo_membership[i]); 2177 kfree(imo, M_IPMOPTS); 2178 } 2179 } 2180 2181 /* 2182 * Routine called from ip_output() to loop back a copy of an IP multicast 2183 * packet to the input queue of a specified interface. Note that this 2184 * calls the output routine of the loopback "driver", but with an interface 2185 * pointer that might NOT be a loopback interface -- evil, but easier than 2186 * replicating that code here. 2187 */ 2188 static void 2189 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2190 int hlen) 2191 { 2192 struct ip *ip; 2193 struct mbuf *copym; 2194 2195 copym = m_copypacket(m, MB_DONTWAIT); 2196 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2197 copym = m_pullup(copym, hlen); 2198 if (copym != NULL) { 2199 /* 2200 * if the checksum hasn't been computed, mark it as valid 2201 */ 2202 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2203 in_delayed_cksum(copym); 2204 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2205 copym->m_pkthdr.csum_flags |= 2206 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2207 copym->m_pkthdr.csum_data = 0xffff; 2208 } 2209 /* 2210 * We don't bother to fragment if the IP length is greater 2211 * than the interface's MTU. Can this possibly matter? 2212 */ 2213 ip = mtod(copym, struct ip *); 2214 ip->ip_len = htons(ip->ip_len); 2215 ip->ip_off = htons(ip->ip_off); 2216 ip->ip_sum = 0; 2217 if (ip->ip_vhl == IP_VHL_BORING) { 2218 ip->ip_sum = in_cksum_hdr(ip); 2219 } else { 2220 ip->ip_sum = in_cksum(copym, hlen); 2221 } 2222 /* 2223 * NB: 2224 * It's not clear whether there are any lingering 2225 * reentrancy problems in other areas which might 2226 * be exposed by using ip_input directly (in 2227 * particular, everything which modifies the packet 2228 * in-place). Yet another option is using the 2229 * protosw directly to deliver the looped back 2230 * packet. For the moment, we'll err on the side 2231 * of safety by using if_simloop(). 2232 */ 2233 #if 1 /* XXX */ 2234 if (dst->sin_family != AF_INET) { 2235 kprintf("ip_mloopback: bad address family %d\n", 2236 dst->sin_family); 2237 dst->sin_family = AF_INET; 2238 } 2239 #endif 2240 2241 #ifdef notdef 2242 copym->m_pkthdr.rcvif = ifp; 2243 ip_input(copym); 2244 #else 2245 if_simloop(ifp, copym, dst->sin_family, 0); 2246 #endif 2247 } 2248 } 2249