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 1.38 2007/10/25 13:13:18 sephe 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 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/protosw.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/proc.h> 52 #include <sys/sysctl.h> 53 #include <sys/thread2.h> 54 #include <sys/in_cksum.h> 55 56 #include <net/if.h> 57 #include <net/netisr.h> 58 #include <net/pfil.h> 59 #include <net/route.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/ip.h> 64 #include <netinet/in_pcb.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip_var.h> 67 68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 69 70 #ifdef IPSEC 71 #include <netinet6/ipsec.h> 72 #include <netproto/key/key.h> 73 #ifdef IPSEC_DEBUG 74 #include <netproto/key/key_debug.h> 75 #else 76 #define KEYDEBUG(lev,arg) 77 #endif 78 #endif /*IPSEC*/ 79 80 #ifdef FAST_IPSEC 81 #include <netproto/ipsec/ipsec.h> 82 #include <netproto/ipsec/xform.h> 83 #include <netproto/ipsec/key.h> 84 #endif /*FAST_IPSEC*/ 85 86 #include <net/ipfw/ip_fw.h> 87 #include <net/dummynet/ip_dummynet.h> 88 89 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\ 90 x, (ntohl(a.s_addr)>>24)&0xFF,\ 91 (ntohl(a.s_addr)>>16)&0xFF,\ 92 (ntohl(a.s_addr)>>8)&0xFF,\ 93 (ntohl(a.s_addr))&0xFF, y); 94 95 u_short ip_id; 96 97 #ifdef MBUF_STRESS_TEST 98 int mbuf_frag_size = 0; 99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 101 #endif 102 103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 104 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 105 static void ip_mloopback 106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 107 static int ip_getmoptions 108 (struct sockopt *, struct ip_moptions *); 109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 110 static int ip_setmoptions 111 (struct sockopt *, struct ip_moptions **); 112 113 int ip_optcopy(struct ip *, struct ip *); 114 115 116 extern struct protosw inetsw[]; 117 118 /* 119 * IP output. The packet in mbuf chain m contains a skeletal IP 120 * header (with len, off, ttl, proto, tos, src, dst). 121 * The mbuf chain containing the packet will be freed. 122 * The mbuf opt, if present, will not be freed. 123 */ 124 int 125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 126 int flags, struct ip_moptions *imo, struct inpcb *inp) 127 { 128 struct ip *ip; 129 struct ifnet *ifp = NULL; /* keep compiler happy */ 130 struct mbuf *m; 131 int hlen = sizeof(struct ip); 132 int len, off, error = 0; 133 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 134 struct in_ifaddr *ia = NULL; 135 int isbroadcast, sw_csum; 136 struct in_addr pkt_dst; 137 struct route iproute; 138 struct m_tag *dn_mtag = NULL; 139 #ifdef IPSEC 140 struct secpolicy *sp = NULL; 141 struct socket *so = inp ? inp->inp_socket : NULL; 142 #endif 143 #ifdef FAST_IPSEC 144 struct m_tag *mtag; 145 struct secpolicy *sp = NULL; 146 struct tdb_ident *tdbi; 147 #endif /* FAST_IPSEC */ 148 struct ip_fw_args args; 149 int src_was_INADDR_ANY = 0; /* as the name says... */ 150 151 args.eh = NULL; 152 args.rule = NULL; 153 args.next_hop = NULL; 154 155 /* Grab info from MT_TAG mbufs prepended to the chain. */ 156 while (m0 != NULL && m0->m_type == MT_TAG) { 157 switch(m0->_m_tag_id) { 158 case PACKET_TAG_IPFORWARD: 159 args.next_hop = (struct sockaddr_in *)m0->m_data; 160 break; 161 default: 162 kprintf("ip_output: unrecognised MT_TAG tag %d\n", 163 m0->_m_tag_id); 164 break; 165 } 166 m0 = m0->m_next; 167 } 168 m = m0; 169 KASSERT(m != NULL && (m->m_flags & M_PKTHDR), ("ip_output: no HDR")); 170 171 /* Extract info from dummynet tag */ 172 dn_mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 173 if (dn_mtag != NULL) { 174 struct dn_pkt *dn_pkt = m_tag_data(dn_mtag); 175 176 /* 177 * The packet was already tagged, so part of the 178 * processing was already done, and we need to go down. 179 * Get parameters from the tag. 180 */ 181 args.rule = dn_pkt->rule; 182 opt = NULL; 183 ro = &dn_pkt->ro; 184 imo = NULL; 185 dst = dn_pkt->dn_dst; 186 ifp = dn_pkt->ifp; 187 flags = dn_pkt->flags; 188 189 /* 190 * Don't delete the dummynet tag here, just unlink it, 191 * since some local variables (like 'ro' and 'dst') are 192 * still referencing certain parts of it. 193 * The dummynet tag will be freed at the end of the 194 * output process. 195 */ 196 m_tag_unlink(m, dn_mtag); 197 } 198 199 if (ro == NULL) { 200 ro = &iproute; 201 bzero(ro, sizeof *ro); 202 } 203 204 if (args.rule != NULL) { /* dummynet already saw us */ 205 ip = mtod(m, struct ip *); 206 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 207 if (ro->ro_rt) 208 ia = ifatoia(ro->ro_rt->rt_ifa); 209 goto sendit; 210 } 211 212 if (opt) { 213 len = 0; 214 m = ip_insertoptions(m, opt, &len); 215 if (len != 0) 216 hlen = len; 217 } 218 ip = mtod(m, struct ip *); 219 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst; 220 221 /* 222 * Fill in IP header. 223 */ 224 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 225 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 226 ip->ip_off &= IP_DF; 227 ip->ip_id = ip_newid(); 228 ipstat.ips_localout++; 229 } else { 230 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 231 } 232 233 dst = (struct sockaddr_in *)&ro->ro_dst; 234 /* 235 * If there is a cached route, 236 * check that it is to the same destination 237 * and is still up. If not, free it and try again. 238 * The address family should also be checked in case of sharing the 239 * cache with IPv6. 240 */ 241 if (ro->ro_rt && 242 (!(ro->ro_rt->rt_flags & RTF_UP) || 243 dst->sin_family != AF_INET || 244 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 245 rtfree(ro->ro_rt); 246 ro->ro_rt = (struct rtentry *)NULL; 247 } 248 if (ro->ro_rt == NULL) { 249 bzero(dst, sizeof *dst); 250 dst->sin_family = AF_INET; 251 dst->sin_len = sizeof *dst; 252 dst->sin_addr = pkt_dst; 253 } 254 /* 255 * If routing to interface only, 256 * short circuit routing lookup. 257 */ 258 if (flags & IP_ROUTETOIF) { 259 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 260 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 261 ipstat.ips_noroute++; 262 error = ENETUNREACH; 263 goto bad; 264 } 265 ifp = ia->ia_ifp; 266 ip->ip_ttl = 1; 267 isbroadcast = in_broadcast(dst->sin_addr, ifp); 268 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 269 imo != NULL && imo->imo_multicast_ifp != NULL) { 270 /* 271 * Bypass the normal routing lookup for multicast 272 * packets if the interface is specified. 273 */ 274 ifp = imo->imo_multicast_ifp; 275 IFP_TO_IA(ifp, ia); 276 isbroadcast = 0; /* fool gcc */ 277 } else { 278 /* 279 * If this is the case, we probably don't want to allocate 280 * a protocol-cloned route since we didn't get one from the 281 * ULP. This lets TCP do its thing, while not burdening 282 * forwarding or ICMP with the overhead of cloning a route. 283 * Of course, we still want to do any cloning requested by 284 * the link layer, as this is probably required in all cases 285 * for correct operation (as it is for ARP). 286 */ 287 if (ro->ro_rt == NULL) 288 rtalloc_ign(ro, RTF_PRCLONING); 289 if (ro->ro_rt == NULL) { 290 ipstat.ips_noroute++; 291 error = EHOSTUNREACH; 292 goto bad; 293 } 294 ia = ifatoia(ro->ro_rt->rt_ifa); 295 ifp = ro->ro_rt->rt_ifp; 296 ro->ro_rt->rt_use++; 297 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 298 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 299 if (ro->ro_rt->rt_flags & RTF_HOST) 300 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 301 else 302 isbroadcast = in_broadcast(dst->sin_addr, ifp); 303 } 304 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 305 struct in_multi *inm; 306 307 m->m_flags |= M_MCAST; 308 /* 309 * IP destination address is multicast. Make sure "dst" 310 * still points to the address in "ro". (It may have been 311 * changed to point to a gateway address, above.) 312 */ 313 dst = (struct sockaddr_in *)&ro->ro_dst; 314 /* 315 * See if the caller provided any multicast options 316 */ 317 if (imo != NULL) { 318 ip->ip_ttl = imo->imo_multicast_ttl; 319 if (imo->imo_multicast_vif != -1) 320 ip->ip_src.s_addr = 321 ip_mcast_src ? 322 ip_mcast_src(imo->imo_multicast_vif) : 323 INADDR_ANY; 324 } else 325 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 326 /* 327 * Confirm that the outgoing interface supports multicast. 328 */ 329 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 330 if (!(ifp->if_flags & IFF_MULTICAST)) { 331 ipstat.ips_noroute++; 332 error = ENETUNREACH; 333 goto bad; 334 } 335 } 336 /* 337 * If source address not specified yet, use address 338 * of outgoing interface. 339 */ 340 if (ip->ip_src.s_addr == INADDR_ANY) { 341 /* Interface may have no addresses. */ 342 if (ia != NULL) 343 ip->ip_src = IA_SIN(ia)->sin_addr; 344 } 345 346 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 347 if (inm != NULL && 348 (imo == NULL || imo->imo_multicast_loop)) { 349 /* 350 * If we belong to the destination multicast group 351 * on the outgoing interface, and the caller did not 352 * forbid loopback, loop back a copy. 353 */ 354 ip_mloopback(ifp, m, dst, hlen); 355 } 356 else { 357 /* 358 * If we are acting as a multicast router, perform 359 * multicast forwarding as if the packet had just 360 * arrived on the interface to which we are about 361 * to send. The multicast forwarding function 362 * recursively calls this function, using the 363 * IP_FORWARDING flag to prevent infinite recursion. 364 * 365 * Multicasts that are looped back by ip_mloopback(), 366 * above, will be forwarded by the ip_input() routine, 367 * if necessary. 368 */ 369 if (ip_mrouter && !(flags & IP_FORWARDING)) { 370 /* 371 * If rsvp daemon is not running, do not 372 * set ip_moptions. This ensures that the packet 373 * is multicast and not just sent down one link 374 * as prescribed by rsvpd. 375 */ 376 if (!rsvp_on) 377 imo = NULL; 378 if (ip_mforward && 379 ip_mforward(ip, ifp, m, imo) != 0) { 380 m_freem(m); 381 goto done; 382 } 383 } 384 } 385 386 /* 387 * Multicasts with a time-to-live of zero may be looped- 388 * back, above, but must not be transmitted on a network. 389 * Also, multicasts addressed to the loopback interface 390 * are not sent -- the above call to ip_mloopback() will 391 * loop back a copy if this host actually belongs to the 392 * destination group on the loopback interface. 393 */ 394 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 395 m_freem(m); 396 goto done; 397 } 398 399 goto sendit; 400 } 401 #ifndef notdef 402 /* 403 * If the source address is not specified yet, use the address 404 * of the outoing interface. In case, keep note we did that, so 405 * if the the firewall changes the next-hop causing the output 406 * interface to change, we can fix that. 407 */ 408 if (ip->ip_src.s_addr == INADDR_ANY) { 409 /* Interface may have no addresses. */ 410 if (ia != NULL) { 411 ip->ip_src = IA_SIN(ia)->sin_addr; 412 src_was_INADDR_ANY = 1; 413 } 414 } 415 #endif /* notdef */ 416 #ifdef ALTQ 417 /* 418 * Disable packet drop hack. 419 * Packetdrop should be done by queueing. 420 */ 421 #else /* !ALTQ */ 422 /* 423 * Verify that we have any chance at all of being able to queue 424 * the packet or packet fragments 425 */ 426 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 427 ifp->if_snd.ifq_maxlen) { 428 error = ENOBUFS; 429 ipstat.ips_odropped++; 430 goto bad; 431 } 432 #endif /* !ALTQ */ 433 434 /* 435 * Look for broadcast address and 436 * verify user is allowed to send 437 * such a packet. 438 */ 439 if (isbroadcast) { 440 if (!(ifp->if_flags & IFF_BROADCAST)) { 441 error = EADDRNOTAVAIL; 442 goto bad; 443 } 444 if (!(flags & IP_ALLOWBROADCAST)) { 445 error = EACCES; 446 goto bad; 447 } 448 /* don't allow broadcast messages to be fragmented */ 449 if (ip->ip_len > ifp->if_mtu) { 450 error = EMSGSIZE; 451 goto bad; 452 } 453 m->m_flags |= M_BCAST; 454 } else { 455 m->m_flags &= ~M_BCAST; 456 } 457 458 sendit: 459 #ifdef IPSEC 460 /* get SP for this packet */ 461 if (so == NULL) 462 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 463 else 464 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 465 466 if (sp == NULL) { 467 ipsecstat.out_inval++; 468 goto bad; 469 } 470 471 error = 0; 472 473 /* check policy */ 474 switch (sp->policy) { 475 case IPSEC_POLICY_DISCARD: 476 /* 477 * This packet is just discarded. 478 */ 479 ipsecstat.out_polvio++; 480 goto bad; 481 482 case IPSEC_POLICY_BYPASS: 483 case IPSEC_POLICY_NONE: 484 /* no need to do IPsec. */ 485 goto skip_ipsec; 486 487 case IPSEC_POLICY_IPSEC: 488 if (sp->req == NULL) { 489 /* acquire a policy */ 490 error = key_spdacquire(sp); 491 goto bad; 492 } 493 break; 494 495 case IPSEC_POLICY_ENTRUST: 496 default: 497 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 498 } 499 { 500 struct ipsec_output_state state; 501 bzero(&state, sizeof state); 502 state.m = m; 503 if (flags & IP_ROUTETOIF) { 504 state.ro = &iproute; 505 bzero(&iproute, sizeof iproute); 506 } else 507 state.ro = ro; 508 state.dst = (struct sockaddr *)dst; 509 510 ip->ip_sum = 0; 511 512 /* 513 * XXX 514 * delayed checksums are not currently compatible with IPsec 515 */ 516 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 517 in_delayed_cksum(m); 518 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 519 } 520 521 ip->ip_len = htons(ip->ip_len); 522 ip->ip_off = htons(ip->ip_off); 523 524 error = ipsec4_output(&state, sp, flags); 525 526 m = state.m; 527 if (flags & IP_ROUTETOIF) { 528 /* 529 * if we have tunnel mode SA, we may need to ignore 530 * IP_ROUTETOIF. 531 */ 532 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 533 flags &= ~IP_ROUTETOIF; 534 ro = state.ro; 535 } 536 } else 537 ro = state.ro; 538 dst = (struct sockaddr_in *)state.dst; 539 if (error) { 540 /* mbuf is already reclaimed in ipsec4_output. */ 541 m0 = NULL; 542 switch (error) { 543 case EHOSTUNREACH: 544 case ENETUNREACH: 545 case EMSGSIZE: 546 case ENOBUFS: 547 case ENOMEM: 548 break; 549 default: 550 kprintf("ip4_output (ipsec): error code %d\n", error); 551 /*fall through*/ 552 case ENOENT: 553 /* don't show these error codes to the user */ 554 error = 0; 555 break; 556 } 557 goto bad; 558 } 559 } 560 561 /* be sure to update variables that are affected by ipsec4_output() */ 562 ip = mtod(m, struct ip *); 563 #ifdef _IP_VHL 564 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 565 #else 566 hlen = ip->ip_hl << 2; 567 #endif 568 if (ro->ro_rt == NULL) { 569 if (!(flags & IP_ROUTETOIF)) { 570 kprintf("ip_output: " 571 "can't update route after IPsec processing\n"); 572 error = EHOSTUNREACH; /*XXX*/ 573 goto bad; 574 } 575 } else { 576 ia = ifatoia(ro->ro_rt->rt_ifa); 577 ifp = ro->ro_rt->rt_ifp; 578 } 579 580 /* make it flipped, again. */ 581 ip->ip_len = ntohs(ip->ip_len); 582 ip->ip_off = ntohs(ip->ip_off); 583 skip_ipsec: 584 #endif /*IPSEC*/ 585 #ifdef FAST_IPSEC 586 /* 587 * Check the security policy (SP) for the packet and, if 588 * required, do IPsec-related processing. There are two 589 * cases here; the first time a packet is sent through 590 * it will be untagged and handled by ipsec4_checkpolicy. 591 * If the packet is resubmitted to ip_output (e.g. after 592 * AH, ESP, etc. processing), there will be a tag to bypass 593 * the lookup and related policy checking. 594 */ 595 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 596 crit_enter(); 597 if (mtag != NULL) { 598 tdbi = (struct tdb_ident *)m_tag_data(mtag); 599 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 600 if (sp == NULL) 601 error = -EINVAL; /* force silent drop */ 602 m_tag_delete(m, mtag); 603 } else { 604 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 605 &error, inp); 606 } 607 /* 608 * There are four return cases: 609 * sp != NULL apply IPsec policy 610 * sp == NULL, error == 0 no IPsec handling needed 611 * sp == NULL, error == -EINVAL discard packet w/o error 612 * sp == NULL, error != 0 discard packet, report error 613 */ 614 if (sp != NULL) { 615 /* Loop detection, check if ipsec processing already done */ 616 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 617 for (mtag = m_tag_first(m); mtag != NULL; 618 mtag = m_tag_next(m, mtag)) { 619 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 620 continue; 621 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 622 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 623 continue; 624 /* 625 * Check if policy has an SA associated with it. 626 * This can happen when an SP has yet to acquire 627 * an SA; e.g. on first reference. If it occurs, 628 * then we let ipsec4_process_packet do its thing. 629 */ 630 if (sp->req->sav == NULL) 631 break; 632 tdbi = (struct tdb_ident *)m_tag_data(mtag); 633 if (tdbi->spi == sp->req->sav->spi && 634 tdbi->proto == sp->req->sav->sah->saidx.proto && 635 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 636 sizeof(union sockaddr_union)) == 0) { 637 /* 638 * No IPsec processing is needed, free 639 * reference to SP. 640 * 641 * NB: null pointer to avoid free at 642 * done: below. 643 */ 644 KEY_FREESP(&sp), sp = NULL; 645 crit_exit(); 646 goto spd_done; 647 } 648 } 649 650 /* 651 * Do delayed checksums now because we send before 652 * this is done in the normal processing path. 653 */ 654 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 655 in_delayed_cksum(m); 656 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 657 } 658 659 ip->ip_len = htons(ip->ip_len); 660 ip->ip_off = htons(ip->ip_off); 661 662 /* NB: callee frees mbuf */ 663 error = ipsec4_process_packet(m, sp->req, flags, 0); 664 /* 665 * Preserve KAME behaviour: ENOENT can be returned 666 * when an SA acquire is in progress. Don't propagate 667 * this to user-level; it confuses applications. 668 * 669 * XXX this will go away when the SADB is redone. 670 */ 671 if (error == ENOENT) 672 error = 0; 673 crit_exit(); 674 goto done; 675 } else { 676 crit_exit(); 677 678 if (error != 0) { 679 /* 680 * Hack: -EINVAL is used to signal that a packet 681 * should be silently discarded. This is typically 682 * because we asked key management for an SA and 683 * it was delayed (e.g. kicked up to IKE). 684 */ 685 if (error == -EINVAL) 686 error = 0; 687 goto bad; 688 } else { 689 /* No IPsec processing for this packet. */ 690 } 691 #ifdef notyet 692 /* 693 * If deferred crypto processing is needed, check that 694 * the interface supports it. 695 */ 696 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 697 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 698 /* notify IPsec to do its own crypto */ 699 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 700 error = EHOSTUNREACH; 701 goto bad; 702 } 703 #endif 704 } 705 spd_done: 706 #endif /* FAST_IPSEC */ 707 /* 708 * IpHack's section. 709 * - Xlate: translate packet's addr/port (NAT). 710 * - Firewall: deny/allow/etc. 711 * - Wrap: fake packet's addr/port <unimpl.> 712 * - Encapsulate: put it in another IP and send out. <unimp.> 713 */ 714 715 /* 716 * Run through list of hooks for output packets. 717 */ 718 if (pfil_has_hooks(&inet_pfil_hook)) { 719 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 720 if (error != 0 || m == NULL) 721 goto done; 722 ip = mtod(m, struct ip *); 723 } 724 725 /* 726 * Check with the firewall... 727 * but not if we are already being fwd'd from a firewall. 728 */ 729 if (fw_enable && IPFW_LOADED && !args.next_hop) { 730 struct sockaddr_in *old = dst; 731 732 args.m = m; 733 args.next_hop = dst; 734 args.oif = ifp; 735 off = ip_fw_chk_ptr(&args); 736 m = args.m; 737 dst = args.next_hop; 738 739 /* 740 * On return we must do the following: 741 * m == NULL -> drop the pkt (old interface, deprecated) 742 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface) 743 * 1<=off<= 0xffff -> DIVERT 744 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe 745 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet 746 * dst != old -> IPFIREWALL_FORWARD 747 * off==0, dst==old -> accept 748 * If some of the above modules are not compiled in, then 749 * we should't have to check the corresponding condition 750 * (because the ipfw control socket should not accept 751 * unsupported rules), but better play safe and drop 752 * packets in case of doubt. 753 */ 754 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) { 755 if (m) 756 m_freem(m); 757 error = EACCES; 758 goto done; 759 } 760 ip = mtod(m, struct ip *); 761 if (off == 0 && dst == old) /* common case */ 762 goto pass; 763 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG)) { 764 /* 765 * pass the pkt to dummynet. Need to include 766 * pipe number, m, ifp, ro, dst because these are 767 * not recomputed in the next pass. 768 * All other parameters have been already used and 769 * so they are not needed anymore. 770 * XXX note: if the ifp or ro entry are deleted 771 * while a pkt is in dummynet, we are in trouble! 772 */ 773 args.ro = ro; 774 args.dst = dst; 775 args.flags = flags; 776 777 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, 778 &args); 779 goto done; 780 } 781 #ifdef IPDIVERT 782 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) { 783 struct mbuf *clone = NULL; 784 785 /* Clone packet if we're doing a 'tee' */ 786 if ((off & IP_FW_PORT_TEE_FLAG)) 787 clone = m_dup(m, MB_DONTWAIT); 788 789 /* 790 * XXX 791 * delayed checksums are not currently compatible 792 * with divert sockets. 793 */ 794 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 795 in_delayed_cksum(m); 796 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 797 } 798 799 /* Restore packet header fields to original values */ 800 ip->ip_len = htons(ip->ip_len); 801 ip->ip_off = htons(ip->ip_off); 802 803 /* Deliver packet to divert input routine */ 804 divert_packet(m, 0, off & 0xffff); 805 806 /* If 'tee', continue with original packet */ 807 if (clone != NULL) { 808 m = clone; 809 ip = mtod(m, struct ip *); 810 goto pass; 811 } 812 goto done; 813 } 814 #endif 815 816 /* IPFIREWALL_FORWARD */ 817 /* 818 * Check dst to make sure it is directly reachable on the 819 * interface we previously thought it was. 820 * If it isn't (which may be likely in some situations) we have 821 * to re-route it (ie, find a route for the next-hop and the 822 * associated interface) and set them here. This is nested 823 * forwarding which in most cases is undesirable, except where 824 * such control is nigh impossible. So we do it here. 825 * And I'm babbling. 826 */ 827 if (off == 0 && old != dst) { /* FORWARD, dst has changed */ 828 #if 0 829 /* 830 * XXX To improve readability, this block should be 831 * changed into a function call as below: 832 */ 833 error = ip_ipforward(&m, &dst, &ifp); 834 if (error) 835 goto bad; 836 if (m == NULL) /* ip_input consumed the mbuf */ 837 goto done; 838 #else 839 struct in_ifaddr *ia; 840 841 /* 842 * XXX sro_fwd below is static, and a pointer 843 * to it gets passed to routines downstream. 844 * This could have surprisingly bad results in 845 * practice, because its content is overwritten 846 * by subsequent packets. 847 */ 848 /* There must be a better way to do this next line... */ 849 static struct route sro_fwd; 850 struct route *ro_fwd = &sro_fwd; 851 852 #if 0 853 print_ip("IPFIREWALL_FORWARD: New dst ip: ", 854 dst->sin_addr, "\n"); 855 #endif 856 857 /* 858 * We need to figure out if we have been forwarded 859 * to a local socket. If so, then we should somehow 860 * "loop back" to ip_input, and get directed to the 861 * PCB as if we had received this packet. This is 862 * because it may be dificult to identify the packets 863 * you want to forward until they are being output 864 * and have selected an interface. (e.g. locally 865 * initiated packets) If we used the loopback inteface, 866 * we would not be able to control what happens 867 * as the packet runs through ip_input() as 868 * it is done through a ISR. 869 */ 870 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr), 871 ia_hash) { 872 /* 873 * If the addr to forward to is one 874 * of ours, we pretend to 875 * be the destination for this packet. 876 */ 877 if (IA_SIN(ia)->sin_addr.s_addr == 878 dst->sin_addr.s_addr) 879 break; 880 } 881 if (ia != NULL) { /* tell ip_input "dont filter" */ 882 struct m_hdr tag; 883 884 tag.mh_type = MT_TAG; 885 tag.mh_flags = PACKET_TAG_IPFORWARD; 886 tag.mh_data = (caddr_t)args.next_hop; 887 tag.mh_next = m; 888 889 if (m->m_pkthdr.rcvif == NULL) 890 m->m_pkthdr.rcvif = ifunit("lo0"); 891 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 892 m->m_pkthdr.csum_flags |= 893 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 894 m->m_pkthdr.csum_data = 0xffff; 895 } 896 m->m_pkthdr.csum_flags |= 897 CSUM_IP_CHECKED | CSUM_IP_VALID; 898 ip->ip_len = htons(ip->ip_len); 899 ip->ip_off = htons(ip->ip_off); 900 ip_input((struct mbuf *)&tag); 901 goto done; 902 } 903 /* Some of the logic for this was nicked from above. 904 * 905 * This rewrites the cached route in a local PCB. 906 * Is this what we want to do? 907 */ 908 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst); 909 ro_fwd->ro_rt = NULL; 910 911 rtalloc_ign(ro_fwd, RTF_PRCLONING); 912 if (ro_fwd->ro_rt == NULL) { 913 ipstat.ips_noroute++; 914 error = EHOSTUNREACH; 915 goto bad; 916 } 917 918 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 919 ifp = ro_fwd->ro_rt->rt_ifp; 920 ro_fwd->ro_rt->rt_use++; 921 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 922 dst = (struct sockaddr_in *) 923 ro_fwd->ro_rt->rt_gateway; 924 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 925 isbroadcast = 926 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 927 else 928 isbroadcast = in_broadcast(dst->sin_addr, ifp); 929 if (ro->ro_rt != NULL) 930 rtfree(ro->ro_rt); 931 ro->ro_rt = ro_fwd->ro_rt; 932 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 933 934 #endif /* ... block to be put into a function */ 935 /* 936 * If we added a default src ip earlier, 937 * which would have been gotten from the-then 938 * interface, do it again, from the new one. 939 */ 940 if (src_was_INADDR_ANY) 941 ip->ip_src = IA_SIN(ia)->sin_addr; 942 goto pass ; 943 } 944 945 /* 946 * if we get here, none of the above matches, and 947 * we have to drop the pkt 948 */ 949 m_freem(m); 950 error = EACCES; /* not sure this is the right error msg */ 951 goto done; 952 } 953 954 pass: 955 /* 127/8 must not appear on wire - RFC1122. */ 956 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 957 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 958 if (!(ifp->if_flags & IFF_LOOPBACK)) { 959 ipstat.ips_badaddr++; 960 error = EADDRNOTAVAIL; 961 goto bad; 962 } 963 } 964 965 m->m_pkthdr.csum_flags |= CSUM_IP; 966 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 967 if (sw_csum & CSUM_DELAY_DATA) { 968 in_delayed_cksum(m); 969 sw_csum &= ~CSUM_DELAY_DATA; 970 } 971 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 972 973 /* 974 * If small enough for interface, or the interface will take 975 * care of the fragmentation for us, can just send directly. 976 */ 977 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 978 !(ip->ip_off & IP_DF))) { 979 ip->ip_len = htons(ip->ip_len); 980 ip->ip_off = htons(ip->ip_off); 981 ip->ip_sum = 0; 982 if (sw_csum & CSUM_DELAY_IP) { 983 if (ip->ip_vhl == IP_VHL_BORING) { 984 ip->ip_sum = in_cksum_hdr(ip); 985 } else { 986 ip->ip_sum = in_cksum(m, hlen); 987 } 988 } 989 990 /* Record statistics for this interface address. */ 991 if (!(flags & IP_FORWARDING) && ia) { 992 ia->ia_ifa.if_opackets++; 993 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 994 } 995 996 #ifdef IPSEC 997 /* clean ipsec history once it goes out of the node */ 998 ipsec_delaux(m); 999 #endif 1000 1001 #ifdef MBUF_STRESS_TEST 1002 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 1003 struct mbuf *m1, *m2; 1004 int length, tmp; 1005 1006 tmp = length = m->m_pkthdr.len; 1007 1008 while ((length -= mbuf_frag_size) >= 1) { 1009 m1 = m_split(m, length, MB_DONTWAIT); 1010 if (m1 == NULL) 1011 break; 1012 m2 = m; 1013 while (m2->m_next != NULL) 1014 m2 = m2->m_next; 1015 m2->m_next = m1; 1016 } 1017 m->m_pkthdr.len = tmp; 1018 } 1019 #endif 1020 lwkt_serialize_enter(ifp->if_serializer); 1021 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, 1022 ro->ro_rt); 1023 lwkt_serialize_exit(ifp->if_serializer); 1024 goto done; 1025 } 1026 1027 if (ip->ip_off & IP_DF) { 1028 error = EMSGSIZE; 1029 /* 1030 * This case can happen if the user changed the MTU 1031 * of an interface after enabling IP on it. Because 1032 * most netifs don't keep track of routes pointing to 1033 * them, there is no way for one to update all its 1034 * routes when the MTU is changed. 1035 */ 1036 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 1037 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 1038 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1039 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1040 } 1041 ipstat.ips_cantfrag++; 1042 goto bad; 1043 } 1044 1045 /* 1046 * Too large for interface; fragment if possible. If successful, 1047 * on return, m will point to a list of packets to be sent. 1048 */ 1049 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1050 if (error) 1051 goto bad; 1052 for (; m; m = m0) { 1053 m0 = m->m_nextpkt; 1054 m->m_nextpkt = NULL; 1055 #ifdef IPSEC 1056 /* clean ipsec history once it goes out of the node */ 1057 ipsec_delaux(m); 1058 #endif 1059 if (error == 0) { 1060 /* Record statistics for this interface address. */ 1061 if (ia != NULL) { 1062 ia->ia_ifa.if_opackets++; 1063 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1064 } 1065 lwkt_serialize_enter(ifp->if_serializer); 1066 error = (*ifp->if_output)(ifp, m, 1067 (struct sockaddr *)dst, 1068 ro->ro_rt); 1069 lwkt_serialize_exit(ifp->if_serializer); 1070 } else { 1071 m_freem(m); 1072 } 1073 } 1074 1075 if (error == 0) 1076 ipstat.ips_fragmented++; 1077 1078 done: 1079 if (ro == &iproute && ro->ro_rt != NULL) { 1080 RTFREE(ro->ro_rt); 1081 ro->ro_rt = NULL; 1082 } 1083 #ifdef IPSEC 1084 if (sp != NULL) { 1085 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1086 kprintf("DP ip_output call free SP:%p\n", sp)); 1087 key_freesp(sp); 1088 } 1089 #endif 1090 #ifdef FAST_IPSEC 1091 if (sp != NULL) 1092 KEY_FREESP(&sp); 1093 #endif 1094 if (dn_mtag != NULL) 1095 m_tag_free(dn_mtag); 1096 1097 return (error); 1098 bad: 1099 m_freem(m); 1100 goto done; 1101 } 1102 1103 /* 1104 * Create a chain of fragments which fit the given mtu. m_frag points to the 1105 * mbuf to be fragmented; on return it points to the chain with the fragments. 1106 * Return 0 if no error. If error, m_frag may contain a partially built 1107 * chain of fragments that should be freed by the caller. 1108 * 1109 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1110 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1111 */ 1112 int 1113 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1114 u_long if_hwassist_flags, int sw_csum) 1115 { 1116 int error = 0; 1117 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1118 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1119 int off; 1120 struct mbuf *m0 = *m_frag; /* the original packet */ 1121 int firstlen; 1122 struct mbuf **mnext; 1123 int nfrags; 1124 1125 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1126 ipstat.ips_cantfrag++; 1127 return EMSGSIZE; 1128 } 1129 1130 /* 1131 * Must be able to put at least 8 bytes per fragment. 1132 */ 1133 if (len < 8) 1134 return EMSGSIZE; 1135 1136 /* 1137 * If the interface will not calculate checksums on 1138 * fragmented packets, then do it here. 1139 */ 1140 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1141 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1142 in_delayed_cksum(m0); 1143 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1144 } 1145 1146 if (len > PAGE_SIZE) { 1147 /* 1148 * Fragment large datagrams such that each segment 1149 * contains a multiple of PAGE_SIZE amount of data, 1150 * plus headers. This enables a receiver to perform 1151 * page-flipping zero-copy optimizations. 1152 * 1153 * XXX When does this help given that sender and receiver 1154 * could have different page sizes, and also mtu could 1155 * be less than the receiver's page size ? 1156 */ 1157 int newlen; 1158 struct mbuf *m; 1159 1160 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1161 off += m->m_len; 1162 1163 /* 1164 * firstlen (off - hlen) must be aligned on an 1165 * 8-byte boundary 1166 */ 1167 if (off < hlen) 1168 goto smart_frag_failure; 1169 off = ((off - hlen) & ~7) + hlen; 1170 newlen = (~PAGE_MASK) & mtu; 1171 if ((newlen + sizeof(struct ip)) > mtu) { 1172 /* we failed, go back the default */ 1173 smart_frag_failure: 1174 newlen = len; 1175 off = hlen + len; 1176 } 1177 len = newlen; 1178 1179 } else { 1180 off = hlen + len; 1181 } 1182 1183 firstlen = off - hlen; 1184 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1185 1186 /* 1187 * Loop through length of segment after first fragment, 1188 * make new header and copy data of each part and link onto chain. 1189 * Here, m0 is the original packet, m is the fragment being created. 1190 * The fragments are linked off the m_nextpkt of the original 1191 * packet, which after processing serves as the first fragment. 1192 */ 1193 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1194 struct ip *mhip; /* ip header on the fragment */ 1195 struct mbuf *m; 1196 int mhlen = sizeof(struct ip); 1197 1198 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1199 if (m == NULL) { 1200 error = ENOBUFS; 1201 ipstat.ips_odropped++; 1202 goto done; 1203 } 1204 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1205 /* 1206 * In the first mbuf, leave room for the link header, then 1207 * copy the original IP header including options. The payload 1208 * goes into an additional mbuf chain returned by m_copy(). 1209 */ 1210 m->m_data += max_linkhdr; 1211 mhip = mtod(m, struct ip *); 1212 *mhip = *ip; 1213 if (hlen > sizeof(struct ip)) { 1214 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1215 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1216 } 1217 m->m_len = mhlen; 1218 /* XXX do we need to add ip->ip_off below ? */ 1219 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1220 if (off + len >= ip->ip_len) { /* last fragment */ 1221 len = ip->ip_len - off; 1222 m->m_flags |= M_LASTFRAG; 1223 } else 1224 mhip->ip_off |= IP_MF; 1225 mhip->ip_len = htons((u_short)(len + mhlen)); 1226 m->m_next = m_copy(m0, off, len); 1227 if (m->m_next == NULL) { /* copy failed */ 1228 m_free(m); 1229 error = ENOBUFS; /* ??? */ 1230 ipstat.ips_odropped++; 1231 goto done; 1232 } 1233 m->m_pkthdr.len = mhlen + len; 1234 m->m_pkthdr.rcvif = (struct ifnet *)NULL; 1235 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1236 mhip->ip_off = htons(mhip->ip_off); 1237 mhip->ip_sum = 0; 1238 if (sw_csum & CSUM_DELAY_IP) 1239 mhip->ip_sum = in_cksum(m, mhlen); 1240 *mnext = m; 1241 mnext = &m->m_nextpkt; 1242 } 1243 ipstat.ips_ofragments += nfrags; 1244 1245 /* set first marker for fragment chain */ 1246 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1247 m0->m_pkthdr.csum_data = nfrags; 1248 1249 /* 1250 * Update first fragment by trimming what's been copied out 1251 * and updating header. 1252 */ 1253 m_adj(m0, hlen + firstlen - ip->ip_len); 1254 m0->m_pkthdr.len = hlen + firstlen; 1255 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1256 ip->ip_off |= IP_MF; 1257 ip->ip_off = htons(ip->ip_off); 1258 ip->ip_sum = 0; 1259 if (sw_csum & CSUM_DELAY_IP) 1260 ip->ip_sum = in_cksum(m0, hlen); 1261 1262 done: 1263 *m_frag = m0; 1264 return error; 1265 } 1266 1267 void 1268 in_delayed_cksum(struct mbuf *m) 1269 { 1270 struct ip *ip; 1271 u_short csum, offset; 1272 1273 ip = mtod(m, struct ip *); 1274 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1275 csum = in_cksum_skip(m, ip->ip_len, offset); 1276 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1277 csum = 0xffff; 1278 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1279 1280 if (offset + sizeof(u_short) > m->m_len) { 1281 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1282 m->m_len, offset, ip->ip_p); 1283 /* 1284 * XXX 1285 * this shouldn't happen, but if it does, the 1286 * correct behavior may be to insert the checksum 1287 * in the existing chain instead of rearranging it. 1288 */ 1289 m = m_pullup(m, offset + sizeof(u_short)); 1290 } 1291 *(u_short *)(m->m_data + offset) = csum; 1292 } 1293 1294 /* 1295 * Insert IP options into preformed packet. 1296 * Adjust IP destination as required for IP source routing, 1297 * as indicated by a non-zero in_addr at the start of the options. 1298 * 1299 * XXX This routine assumes that the packet has no options in place. 1300 */ 1301 static struct mbuf * 1302 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1303 { 1304 struct ipoption *p = mtod(opt, struct ipoption *); 1305 struct mbuf *n; 1306 struct ip *ip = mtod(m, struct ip *); 1307 unsigned optlen; 1308 1309 optlen = opt->m_len - sizeof p->ipopt_dst; 1310 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1311 *phlen = 0; 1312 return (m); /* XXX should fail */ 1313 } 1314 if (p->ipopt_dst.s_addr) 1315 ip->ip_dst = p->ipopt_dst; 1316 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1317 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1318 if (n == NULL) { 1319 *phlen = 0; 1320 return (m); 1321 } 1322 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 1323 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1324 m->m_len -= sizeof(struct ip); 1325 m->m_data += sizeof(struct ip); 1326 n->m_next = m; 1327 m = n; 1328 m->m_len = optlen + sizeof(struct ip); 1329 m->m_data += max_linkhdr; 1330 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1331 } else { 1332 m->m_data -= optlen; 1333 m->m_len += optlen; 1334 m->m_pkthdr.len += optlen; 1335 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1336 } 1337 ip = mtod(m, struct ip *); 1338 bcopy(p->ipopt_list, ip + 1, optlen); 1339 *phlen = sizeof(struct ip) + optlen; 1340 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1341 ip->ip_len += optlen; 1342 return (m); 1343 } 1344 1345 /* 1346 * Copy options from ip to jp, 1347 * omitting those not copied during fragmentation. 1348 */ 1349 int 1350 ip_optcopy(struct ip *ip, struct ip *jp) 1351 { 1352 u_char *cp, *dp; 1353 int opt, optlen, cnt; 1354 1355 cp = (u_char *)(ip + 1); 1356 dp = (u_char *)(jp + 1); 1357 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1358 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1359 opt = cp[0]; 1360 if (opt == IPOPT_EOL) 1361 break; 1362 if (opt == IPOPT_NOP) { 1363 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1364 *dp++ = IPOPT_NOP; 1365 optlen = 1; 1366 continue; 1367 } 1368 1369 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1370 ("ip_optcopy: malformed ipv4 option")); 1371 optlen = cp[IPOPT_OLEN]; 1372 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1373 ("ip_optcopy: malformed ipv4 option")); 1374 1375 /* bogus lengths should have been caught by ip_dooptions */ 1376 if (optlen > cnt) 1377 optlen = cnt; 1378 if (IPOPT_COPIED(opt)) { 1379 bcopy(cp, dp, optlen); 1380 dp += optlen; 1381 } 1382 } 1383 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1384 *dp++ = IPOPT_EOL; 1385 return (optlen); 1386 } 1387 1388 /* 1389 * IP socket option processing. 1390 */ 1391 int 1392 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1393 { 1394 struct inpcb *inp = so->so_pcb; 1395 int error, optval; 1396 1397 error = optval = 0; 1398 if (sopt->sopt_level != IPPROTO_IP) { 1399 return (EINVAL); 1400 } 1401 1402 switch (sopt->sopt_dir) { 1403 case SOPT_SET: 1404 switch (sopt->sopt_name) { 1405 case IP_OPTIONS: 1406 #ifdef notyet 1407 case IP_RETOPTS: 1408 #endif 1409 { 1410 struct mbuf *m; 1411 if (sopt->sopt_valsize > MLEN) { 1412 error = EMSGSIZE; 1413 break; 1414 } 1415 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1416 if (m == NULL) { 1417 error = ENOBUFS; 1418 break; 1419 } 1420 m->m_len = sopt->sopt_valsize; 1421 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 1422 m->m_len); 1423 1424 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1425 m)); 1426 } 1427 1428 case IP_TOS: 1429 case IP_TTL: 1430 case IP_MINTTL: 1431 case IP_RECVOPTS: 1432 case IP_RECVRETOPTS: 1433 case IP_RECVDSTADDR: 1434 case IP_RECVIF: 1435 case IP_RECVTTL: 1436 case IP_FAITH: 1437 error = sooptcopyin(sopt, &optval, sizeof optval, 1438 sizeof optval); 1439 if (error) 1440 break; 1441 1442 switch (sopt->sopt_name) { 1443 case IP_TOS: 1444 inp->inp_ip_tos = optval; 1445 break; 1446 1447 case IP_TTL: 1448 inp->inp_ip_ttl = optval; 1449 break; 1450 case IP_MINTTL: 1451 if (optval > 0 && optval <= MAXTTL) 1452 inp->inp_ip_minttl = optval; 1453 else 1454 error = EINVAL; 1455 break; 1456 #define OPTSET(bit) \ 1457 if (optval) \ 1458 inp->inp_flags |= bit; \ 1459 else \ 1460 inp->inp_flags &= ~bit; 1461 1462 case IP_RECVOPTS: 1463 OPTSET(INP_RECVOPTS); 1464 break; 1465 1466 case IP_RECVRETOPTS: 1467 OPTSET(INP_RECVRETOPTS); 1468 break; 1469 1470 case IP_RECVDSTADDR: 1471 OPTSET(INP_RECVDSTADDR); 1472 break; 1473 1474 case IP_RECVIF: 1475 OPTSET(INP_RECVIF); 1476 break; 1477 1478 case IP_RECVTTL: 1479 OPTSET(INP_RECVTTL); 1480 break; 1481 1482 case IP_FAITH: 1483 OPTSET(INP_FAITH); 1484 break; 1485 } 1486 break; 1487 #undef OPTSET 1488 1489 case IP_MULTICAST_IF: 1490 case IP_MULTICAST_VIF: 1491 case IP_MULTICAST_TTL: 1492 case IP_MULTICAST_LOOP: 1493 case IP_ADD_MEMBERSHIP: 1494 case IP_DROP_MEMBERSHIP: 1495 error = ip_setmoptions(sopt, &inp->inp_moptions); 1496 break; 1497 1498 case IP_PORTRANGE: 1499 error = sooptcopyin(sopt, &optval, sizeof optval, 1500 sizeof optval); 1501 if (error) 1502 break; 1503 1504 switch (optval) { 1505 case IP_PORTRANGE_DEFAULT: 1506 inp->inp_flags &= ~(INP_LOWPORT); 1507 inp->inp_flags &= ~(INP_HIGHPORT); 1508 break; 1509 1510 case IP_PORTRANGE_HIGH: 1511 inp->inp_flags &= ~(INP_LOWPORT); 1512 inp->inp_flags |= INP_HIGHPORT; 1513 break; 1514 1515 case IP_PORTRANGE_LOW: 1516 inp->inp_flags &= ~(INP_HIGHPORT); 1517 inp->inp_flags |= INP_LOWPORT; 1518 break; 1519 1520 default: 1521 error = EINVAL; 1522 break; 1523 } 1524 break; 1525 1526 #if defined(IPSEC) || defined(FAST_IPSEC) 1527 case IP_IPSEC_POLICY: 1528 { 1529 caddr_t req; 1530 size_t len = 0; 1531 int priv; 1532 struct mbuf *m; 1533 int optname; 1534 1535 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1536 break; 1537 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1538 break; 1539 priv = (sopt->sopt_td != NULL && 1540 suser(sopt->sopt_td) != 0) ? 0 : 1; 1541 req = mtod(m, caddr_t); 1542 len = m->m_len; 1543 optname = sopt->sopt_name; 1544 error = ipsec4_set_policy(inp, optname, req, len, priv); 1545 m_freem(m); 1546 break; 1547 } 1548 #endif /*IPSEC*/ 1549 1550 default: 1551 error = ENOPROTOOPT; 1552 break; 1553 } 1554 break; 1555 1556 case SOPT_GET: 1557 switch (sopt->sopt_name) { 1558 case IP_OPTIONS: 1559 case IP_RETOPTS: 1560 if (inp->inp_options) 1561 error = sooptcopyout(sopt, 1562 mtod(inp->inp_options, 1563 char *), 1564 inp->inp_options->m_len); 1565 else 1566 sopt->sopt_valsize = 0; 1567 break; 1568 1569 case IP_TOS: 1570 case IP_TTL: 1571 case IP_MINTTL: 1572 case IP_RECVOPTS: 1573 case IP_RECVRETOPTS: 1574 case IP_RECVDSTADDR: 1575 case IP_RECVTTL: 1576 case IP_RECVIF: 1577 case IP_PORTRANGE: 1578 case IP_FAITH: 1579 switch (sopt->sopt_name) { 1580 1581 case IP_TOS: 1582 optval = inp->inp_ip_tos; 1583 break; 1584 1585 case IP_TTL: 1586 optval = inp->inp_ip_ttl; 1587 break; 1588 case IP_MINTTL: 1589 optval = inp->inp_ip_minttl; 1590 break; 1591 1592 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1593 1594 case IP_RECVOPTS: 1595 optval = OPTBIT(INP_RECVOPTS); 1596 break; 1597 1598 case IP_RECVRETOPTS: 1599 optval = OPTBIT(INP_RECVRETOPTS); 1600 break; 1601 1602 case IP_RECVDSTADDR: 1603 optval = OPTBIT(INP_RECVDSTADDR); 1604 break; 1605 1606 case IP_RECVTTL: 1607 optval = OPTBIT(INP_RECVTTL); 1608 break; 1609 1610 case IP_RECVIF: 1611 optval = OPTBIT(INP_RECVIF); 1612 break; 1613 1614 case IP_PORTRANGE: 1615 if (inp->inp_flags & INP_HIGHPORT) 1616 optval = IP_PORTRANGE_HIGH; 1617 else if (inp->inp_flags & INP_LOWPORT) 1618 optval = IP_PORTRANGE_LOW; 1619 else 1620 optval = 0; 1621 break; 1622 1623 case IP_FAITH: 1624 optval = OPTBIT(INP_FAITH); 1625 break; 1626 } 1627 error = sooptcopyout(sopt, &optval, sizeof optval); 1628 break; 1629 1630 case IP_MULTICAST_IF: 1631 case IP_MULTICAST_VIF: 1632 case IP_MULTICAST_TTL: 1633 case IP_MULTICAST_LOOP: 1634 case IP_ADD_MEMBERSHIP: 1635 case IP_DROP_MEMBERSHIP: 1636 error = ip_getmoptions(sopt, inp->inp_moptions); 1637 break; 1638 1639 #if defined(IPSEC) || defined(FAST_IPSEC) 1640 case IP_IPSEC_POLICY: 1641 { 1642 struct mbuf *m = NULL; 1643 caddr_t req = NULL; 1644 size_t len = 0; 1645 1646 if (m != NULL) { 1647 req = mtod(m, caddr_t); 1648 len = m->m_len; 1649 } 1650 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1651 if (error == 0) 1652 error = soopt_mcopyout(sopt, m); /* XXX */ 1653 if (error == 0) 1654 m_freem(m); 1655 break; 1656 } 1657 #endif /*IPSEC*/ 1658 1659 default: 1660 error = ENOPROTOOPT; 1661 break; 1662 } 1663 break; 1664 } 1665 return (error); 1666 } 1667 1668 /* 1669 * Set up IP options in pcb for insertion in output packets. 1670 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1671 * with destination address if source routed. 1672 */ 1673 static int 1674 ip_pcbopts(int optname, struct mbuf **pcbopt, 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 m_free(*pcbopt); 1683 *pcbopt = 0; 1684 if (m == NULL || m->m_len == 0) { 1685 /* 1686 * Only turning off any previous options. 1687 */ 1688 if (m != NULL) 1689 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), cp, 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(&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(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1752 &cp[IPOPT_OFFSET+1], 1753 cnt - (IPOPT_MINOFF - 1)); 1754 break; 1755 } 1756 } 1757 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1758 goto bad; 1759 *pcbopt = m; 1760 return (0); 1761 1762 bad: 1763 m_free(m); 1764 return (EINVAL); 1765 } 1766 1767 /* 1768 * XXX 1769 * The whole multicast option thing needs to be re-thought. 1770 * Several of these options are equally applicable to non-multicast 1771 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1772 * standard option (IP_TTL). 1773 */ 1774 1775 /* 1776 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1777 */ 1778 static struct ifnet * 1779 ip_multicast_if(struct in_addr *a, int *ifindexp) 1780 { 1781 int ifindex; 1782 struct ifnet *ifp; 1783 1784 if (ifindexp) 1785 *ifindexp = 0; 1786 if (ntohl(a->s_addr) >> 24 == 0) { 1787 ifindex = ntohl(a->s_addr) & 0xffffff; 1788 if (ifindex < 0 || if_index < ifindex) 1789 return NULL; 1790 ifp = ifindex2ifnet[ifindex]; 1791 if (ifindexp) 1792 *ifindexp = ifindex; 1793 } else { 1794 INADDR_TO_IFP(*a, ifp); 1795 } 1796 return ifp; 1797 } 1798 1799 /* 1800 * Set the IP multicast options in response to user setsockopt(). 1801 */ 1802 static int 1803 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1804 { 1805 int error = 0; 1806 int i; 1807 struct in_addr addr; 1808 struct ip_mreq mreq; 1809 struct ifnet *ifp; 1810 struct ip_moptions *imo = *imop; 1811 int ifindex; 1812 1813 if (imo == NULL) { 1814 /* 1815 * No multicast option buffer attached to the pcb; 1816 * allocate one and initialize to default values. 1817 */ 1818 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1819 1820 if (imo == NULL) 1821 return (ENOBUFS); 1822 *imop = imo; 1823 imo->imo_multicast_ifp = NULL; 1824 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1825 imo->imo_multicast_vif = -1; 1826 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1827 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1828 imo->imo_num_memberships = 0; 1829 } 1830 1831 switch (sopt->sopt_name) { 1832 /* store an index number for the vif you wanna use in the send */ 1833 case IP_MULTICAST_VIF: 1834 if (legal_vif_num == 0) { 1835 error = EOPNOTSUPP; 1836 break; 1837 } 1838 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1839 if (error) 1840 break; 1841 if (!legal_vif_num(i) && (i != -1)) { 1842 error = EINVAL; 1843 break; 1844 } 1845 imo->imo_multicast_vif = i; 1846 break; 1847 1848 case IP_MULTICAST_IF: 1849 /* 1850 * Select the interface for outgoing multicast packets. 1851 */ 1852 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1853 if (error) 1854 break; 1855 /* 1856 * INADDR_ANY is used to remove a previous selection. 1857 * When no interface is selected, a default one is 1858 * chosen every time a multicast packet is sent. 1859 */ 1860 if (addr.s_addr == INADDR_ANY) { 1861 imo->imo_multicast_ifp = NULL; 1862 break; 1863 } 1864 /* 1865 * The selected interface is identified by its local 1866 * IP address. Find the interface and confirm that 1867 * it supports multicasting. 1868 */ 1869 crit_enter(); 1870 ifp = ip_multicast_if(&addr, &ifindex); 1871 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1872 crit_exit(); 1873 error = EADDRNOTAVAIL; 1874 break; 1875 } 1876 imo->imo_multicast_ifp = ifp; 1877 if (ifindex) 1878 imo->imo_multicast_addr = addr; 1879 else 1880 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1881 crit_exit(); 1882 break; 1883 1884 case IP_MULTICAST_TTL: 1885 /* 1886 * Set the IP time-to-live for outgoing multicast packets. 1887 * The original multicast API required a char argument, 1888 * which is inconsistent with the rest of the socket API. 1889 * We allow either a char or an int. 1890 */ 1891 if (sopt->sopt_valsize == 1) { 1892 u_char ttl; 1893 error = sooptcopyin(sopt, &ttl, 1, 1); 1894 if (error) 1895 break; 1896 imo->imo_multicast_ttl = ttl; 1897 } else { 1898 u_int ttl; 1899 error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl); 1900 if (error) 1901 break; 1902 if (ttl > 255) 1903 error = EINVAL; 1904 else 1905 imo->imo_multicast_ttl = ttl; 1906 } 1907 break; 1908 1909 case IP_MULTICAST_LOOP: 1910 /* 1911 * Set the loopback flag for outgoing multicast packets. 1912 * Must be zero or one. The original multicast API required a 1913 * char argument, which is inconsistent with the rest 1914 * of the socket API. We allow either a char or an int. 1915 */ 1916 if (sopt->sopt_valsize == 1) { 1917 u_char loop; 1918 1919 error = sooptcopyin(sopt, &loop, 1, 1); 1920 if (error) 1921 break; 1922 imo->imo_multicast_loop = !!loop; 1923 } else { 1924 u_int loop; 1925 1926 error = sooptcopyin(sopt, &loop, sizeof loop, 1927 sizeof loop); 1928 if (error) 1929 break; 1930 imo->imo_multicast_loop = !!loop; 1931 } 1932 break; 1933 1934 case IP_ADD_MEMBERSHIP: 1935 /* 1936 * Add a multicast group membership. 1937 * Group must be a valid IP multicast address. 1938 */ 1939 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1940 if (error) 1941 break; 1942 1943 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1944 error = EINVAL; 1945 break; 1946 } 1947 crit_enter(); 1948 /* 1949 * If no interface address was provided, use the interface of 1950 * the route to the given multicast address. 1951 */ 1952 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1953 struct sockaddr_in dst; 1954 struct rtentry *rt; 1955 1956 bzero(&dst, sizeof(struct sockaddr_in)); 1957 dst.sin_len = sizeof(struct sockaddr_in); 1958 dst.sin_family = AF_INET; 1959 dst.sin_addr = mreq.imr_multiaddr; 1960 rt = rtlookup((struct sockaddr *)&dst); 1961 if (rt == NULL) { 1962 error = EADDRNOTAVAIL; 1963 crit_exit(); 1964 break; 1965 } 1966 --rt->rt_refcnt; 1967 ifp = rt->rt_ifp; 1968 } else { 1969 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1970 } 1971 1972 /* 1973 * See if we found an interface, and confirm that it 1974 * supports multicast. 1975 */ 1976 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1977 error = EADDRNOTAVAIL; 1978 crit_exit(); 1979 break; 1980 } 1981 /* 1982 * See if the membership already exists or if all the 1983 * membership slots are full. 1984 */ 1985 for (i = 0; i < imo->imo_num_memberships; ++i) { 1986 if (imo->imo_membership[i]->inm_ifp == ifp && 1987 imo->imo_membership[i]->inm_addr.s_addr 1988 == mreq.imr_multiaddr.s_addr) 1989 break; 1990 } 1991 if (i < imo->imo_num_memberships) { 1992 error = EADDRINUSE; 1993 crit_exit(); 1994 break; 1995 } 1996 if (i == IP_MAX_MEMBERSHIPS) { 1997 error = ETOOMANYREFS; 1998 crit_exit(); 1999 break; 2000 } 2001 /* 2002 * Everything looks good; add a new record to the multicast 2003 * address list for the given interface. 2004 */ 2005 if ((imo->imo_membership[i] = 2006 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 2007 error = ENOBUFS; 2008 crit_exit(); 2009 break; 2010 } 2011 ++imo->imo_num_memberships; 2012 crit_exit(); 2013 break; 2014 2015 case IP_DROP_MEMBERSHIP: 2016 /* 2017 * Drop a multicast group membership. 2018 * Group must be a valid IP multicast address. 2019 */ 2020 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 2021 if (error) 2022 break; 2023 2024 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2025 error = EINVAL; 2026 break; 2027 } 2028 2029 crit_enter(); 2030 /* 2031 * If an interface address was specified, get a pointer 2032 * to its ifnet structure. 2033 */ 2034 if (mreq.imr_interface.s_addr == INADDR_ANY) 2035 ifp = NULL; 2036 else { 2037 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2038 if (ifp == NULL) { 2039 error = EADDRNOTAVAIL; 2040 crit_exit(); 2041 break; 2042 } 2043 } 2044 /* 2045 * Find the membership in the membership array. 2046 */ 2047 for (i = 0; i < imo->imo_num_memberships; ++i) { 2048 if ((ifp == NULL || 2049 imo->imo_membership[i]->inm_ifp == ifp) && 2050 imo->imo_membership[i]->inm_addr.s_addr == 2051 mreq.imr_multiaddr.s_addr) 2052 break; 2053 } 2054 if (i == imo->imo_num_memberships) { 2055 error = EADDRNOTAVAIL; 2056 crit_exit(); 2057 break; 2058 } 2059 /* 2060 * Give up the multicast address record to which the 2061 * membership points. 2062 */ 2063 in_delmulti(imo->imo_membership[i]); 2064 /* 2065 * Remove the gap in the membership array. 2066 */ 2067 for (++i; i < imo->imo_num_memberships; ++i) 2068 imo->imo_membership[i-1] = imo->imo_membership[i]; 2069 --imo->imo_num_memberships; 2070 crit_exit(); 2071 break; 2072 2073 default: 2074 error = EOPNOTSUPP; 2075 break; 2076 } 2077 2078 /* 2079 * If all options have default values, no need to keep the mbuf. 2080 */ 2081 if (imo->imo_multicast_ifp == NULL && 2082 imo->imo_multicast_vif == -1 && 2083 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2084 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2085 imo->imo_num_memberships == 0) { 2086 kfree(*imop, M_IPMOPTS); 2087 *imop = NULL; 2088 } 2089 2090 return (error); 2091 } 2092 2093 /* 2094 * Return the IP multicast options in response to user getsockopt(). 2095 */ 2096 static int 2097 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2098 { 2099 struct in_addr addr; 2100 struct in_ifaddr *ia; 2101 int error, optval; 2102 u_char coptval; 2103 2104 error = 0; 2105 switch (sopt->sopt_name) { 2106 case IP_MULTICAST_VIF: 2107 if (imo != NULL) 2108 optval = imo->imo_multicast_vif; 2109 else 2110 optval = -1; 2111 error = sooptcopyout(sopt, &optval, sizeof optval); 2112 break; 2113 2114 case IP_MULTICAST_IF: 2115 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2116 addr.s_addr = INADDR_ANY; 2117 else if (imo->imo_multicast_addr.s_addr) { 2118 /* return the value user has set */ 2119 addr = imo->imo_multicast_addr; 2120 } else { 2121 IFP_TO_IA(imo->imo_multicast_ifp, ia); 2122 addr.s_addr = (ia == NULL) ? INADDR_ANY 2123 : IA_SIN(ia)->sin_addr.s_addr; 2124 } 2125 error = sooptcopyout(sopt, &addr, sizeof addr); 2126 break; 2127 2128 case IP_MULTICAST_TTL: 2129 if (imo == NULL) 2130 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2131 else 2132 optval = coptval = imo->imo_multicast_ttl; 2133 if (sopt->sopt_valsize == 1) 2134 error = sooptcopyout(sopt, &coptval, 1); 2135 else 2136 error = sooptcopyout(sopt, &optval, sizeof optval); 2137 break; 2138 2139 case IP_MULTICAST_LOOP: 2140 if (imo == NULL) 2141 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2142 else 2143 optval = coptval = imo->imo_multicast_loop; 2144 if (sopt->sopt_valsize == 1) 2145 error = sooptcopyout(sopt, &coptval, 1); 2146 else 2147 error = sooptcopyout(sopt, &optval, sizeof optval); 2148 break; 2149 2150 default: 2151 error = ENOPROTOOPT; 2152 break; 2153 } 2154 return (error); 2155 } 2156 2157 /* 2158 * Discard the IP multicast options. 2159 */ 2160 void 2161 ip_freemoptions(struct ip_moptions *imo) 2162 { 2163 int i; 2164 2165 if (imo != NULL) { 2166 for (i = 0; i < imo->imo_num_memberships; ++i) 2167 in_delmulti(imo->imo_membership[i]); 2168 kfree(imo, M_IPMOPTS); 2169 } 2170 } 2171 2172 /* 2173 * Routine called from ip_output() to loop back a copy of an IP multicast 2174 * packet to the input queue of a specified interface. Note that this 2175 * calls the output routine of the loopback "driver", but with an interface 2176 * pointer that might NOT be a loopback interface -- evil, but easier than 2177 * replicating that code here. 2178 */ 2179 static void 2180 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2181 int hlen) 2182 { 2183 struct ip *ip; 2184 struct mbuf *copym; 2185 2186 copym = m_copypacket(m, MB_DONTWAIT); 2187 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2188 copym = m_pullup(copym, hlen); 2189 if (copym != NULL) { 2190 /* 2191 * if the checksum hasn't been computed, mark it as valid 2192 */ 2193 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2194 in_delayed_cksum(copym); 2195 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2196 copym->m_pkthdr.csum_flags |= 2197 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2198 copym->m_pkthdr.csum_data = 0xffff; 2199 } 2200 /* 2201 * We don't bother to fragment if the IP length is greater 2202 * than the interface's MTU. Can this possibly matter? 2203 */ 2204 ip = mtod(copym, struct ip *); 2205 ip->ip_len = htons(ip->ip_len); 2206 ip->ip_off = htons(ip->ip_off); 2207 ip->ip_sum = 0; 2208 if (ip->ip_vhl == IP_VHL_BORING) { 2209 ip->ip_sum = in_cksum_hdr(ip); 2210 } else { 2211 ip->ip_sum = in_cksum(copym, hlen); 2212 } 2213 /* 2214 * NB: 2215 * It's not clear whether there are any lingering 2216 * reentrancy problems in other areas which might 2217 * be exposed by using ip_input directly (in 2218 * particular, everything which modifies the packet 2219 * in-place). Yet another option is using the 2220 * protosw directly to deliver the looped back 2221 * packet. For the moment, we'll err on the side 2222 * of safety by using if_simloop(). 2223 */ 2224 #if 1 /* XXX */ 2225 if (dst->sin_family != AF_INET) { 2226 kprintf("ip_mloopback: bad address family %d\n", 2227 dst->sin_family); 2228 dst->sin_family = AF_INET; 2229 } 2230 #endif 2231 2232 #ifdef notdef 2233 copym->m_pkthdr.rcvif = ifp; 2234 ip_input(copym); 2235 #else 2236 if_simloop(ifp, copym, dst->sin_family, 0); 2237 #endif 2238 } 2239 } 2240