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 */ 32 33 #define _IP_VHL 34 35 #include "opt_ipdn.h" 36 #include "opt_ipdivert.h" 37 #include "opt_ipsec.h" 38 #include "opt_mbuf_stress_test.h" 39 #include "opt_mpls.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/protosw.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/proc.h> 50 #include <sys/priv.h> 51 #include <sys/sysctl.h> 52 #include <sys/in_cksum.h> 53 #include <sys/lock.h> 54 55 #include <sys/thread2.h> 56 #include <sys/mplock2.h> 57 #include <sys/msgport2.h> 58 59 #include <net/if.h> 60 #include <net/netisr.h> 61 #include <net/pfil.h> 62 #include <net/route.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_systm.h> 66 #include <netinet/ip.h> 67 #include <netinet/in_pcb.h> 68 #include <netinet/in_var.h> 69 #include <netinet/ip_var.h> 70 71 #include <netproto/mpls/mpls_var.h> 72 73 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 74 75 #ifdef IPSEC 76 #include <netinet6/ipsec.h> 77 #include <netproto/key/key.h> 78 #ifdef IPSEC_DEBUG 79 #include <netproto/key/key_debug.h> 80 #else 81 #define KEYDEBUG(lev,arg) 82 #endif 83 #endif /*IPSEC*/ 84 85 #ifdef FAST_IPSEC 86 #include <netproto/ipsec/ipsec.h> 87 #include <netproto/ipsec/xform.h> 88 #include <netproto/ipsec/key.h> 89 #endif /*FAST_IPSEC*/ 90 91 #include <net/ipfw/ip_fw.h> 92 #include <net/dummynet/ip_dummynet.h> 93 94 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\ 95 x, (ntohl(a.s_addr)>>24)&0xFF,\ 96 (ntohl(a.s_addr)>>16)&0xFF,\ 97 (ntohl(a.s_addr)>>8)&0xFF,\ 98 (ntohl(a.s_addr))&0xFF, y); 99 100 u_short ip_id; 101 102 #ifdef MBUF_STRESS_TEST 103 int mbuf_frag_size = 0; 104 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 105 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 106 #endif 107 108 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 109 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 110 static void ip_mloopback 111 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 112 static int ip_getmoptions 113 (struct sockopt *, struct ip_moptions *); 114 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 115 static int ip_setmoptions 116 (struct sockopt *, struct ip_moptions **); 117 118 int ip_optcopy(struct ip *, struct ip *); 119 120 extern int route_assert_owner_access; 121 122 extern struct protosw inetsw[]; 123 124 static int 125 ip_localforward(struct mbuf *m, const struct sockaddr_in *dst, int hlen) 126 { 127 struct in_ifaddr_container *iac; 128 129 /* 130 * We need to figure out if we have been forwarded to a local 131 * socket. If so, then we should somehow "loop back" to 132 * ip_input(), and get directed to the PCB as if we had received 133 * this packet. This is because it may be difficult to identify 134 * the packets you want to forward until they are being output 135 * and have selected an interface (e.g. locally initiated 136 * packets). If we used the loopback inteface, we would not be 137 * able to control what happens as the packet runs through 138 * ip_input() as it is done through a ISR. 139 */ 140 LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 141 /* 142 * If the addr to forward to is one of ours, we pretend 143 * to be the destination for this packet. 144 */ 145 if (IA_SIN(iac->ia)->sin_addr.s_addr == dst->sin_addr.s_addr) 146 break; 147 } 148 if (iac != NULL) { 149 struct ip *ip; 150 151 if (m->m_pkthdr.rcvif == NULL) 152 m->m_pkthdr.rcvif = ifunit("lo0"); 153 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 154 m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | 155 CSUM_PSEUDO_HDR; 156 m->m_pkthdr.csum_data = 0xffff; 157 } 158 m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; 159 160 /* 161 * Make sure that the IP header is in one mbuf, 162 * required by ip_input 163 */ 164 if (m->m_len < hlen) { 165 m = m_pullup(m, hlen); 166 if (m == NULL) { 167 /* The packet was freed; we are done */ 168 return 1; 169 } 170 } 171 ip = mtod(m, struct ip *); 172 173 ip->ip_len = htons(ip->ip_len); 174 ip->ip_off = htons(ip->ip_off); 175 ip_input(m); 176 177 return 1; /* The packet gets forwarded locally */ 178 } 179 return 0; 180 } 181 182 /* 183 * IP output. The packet in mbuf chain m contains a skeletal IP 184 * header (with len, off, ttl, proto, tos, src, dst). 185 * The mbuf chain containing the packet will be freed. 186 * The mbuf opt, if present, will not be freed. 187 */ 188 int 189 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 190 int flags, struct ip_moptions *imo, struct inpcb *inp) 191 { 192 struct ip *ip; 193 struct ifnet *ifp = NULL; /* keep compiler happy */ 194 struct mbuf *m; 195 int hlen = sizeof(struct ip); 196 int len, error = 0; 197 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 198 struct in_ifaddr *ia = NULL; 199 int isbroadcast, sw_csum; 200 struct in_addr pkt_dst; 201 struct route iproute; 202 struct m_tag *mtag; 203 #ifdef IPSEC 204 struct secpolicy *sp = NULL; 205 struct socket *so = inp ? inp->inp_socket : NULL; 206 #endif 207 #ifdef FAST_IPSEC 208 struct secpolicy *sp = NULL; 209 struct tdb_ident *tdbi; 210 #endif /* FAST_IPSEC */ 211 struct sockaddr_in *next_hop = NULL; 212 int src_was_INADDR_ANY = 0; /* as the name says... */ 213 214 m = m0; 215 M_ASSERTPKTHDR(m); 216 217 if (ro == NULL) { 218 ro = &iproute; 219 bzero(ro, sizeof *ro); 220 } else if (ro->ro_rt != NULL && ro->ro_rt->rt_cpuid != mycpuid) { 221 if (flags & IP_DEBUGROUTE) { 222 if (route_assert_owner_access) { 223 panic("ip_output: " 224 "rt rt_cpuid %d accessed on cpu %d\n", 225 ro->ro_rt->rt_cpuid, mycpuid); 226 } else { 227 kprintf("ip_output: " 228 "rt rt_cpuid %d accessed on cpu %d\n", 229 ro->ro_rt->rt_cpuid, mycpuid); 230 print_backtrace(-1); 231 } 232 } 233 234 /* 235 * XXX 236 * If the cached rtentry's owner CPU is not the current CPU, 237 * then don't touch the cached rtentry (remote free is too 238 * expensive in this context); just relocate the route. 239 */ 240 ro = &iproute; 241 bzero(ro, sizeof *ro); 242 } 243 244 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 245 /* Next hop */ 246 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 247 KKASSERT(mtag != NULL); 248 next_hop = m_tag_data(mtag); 249 } 250 251 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 252 struct dn_pkt *dn_pkt; 253 254 /* Extract info from dummynet tag */ 255 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 256 KKASSERT(mtag != NULL); 257 dn_pkt = m_tag_data(mtag); 258 259 /* 260 * The packet was already tagged, so part of the 261 * processing was already done, and we need to go down. 262 * Get the calculated parameters from the tag. 263 */ 264 ifp = dn_pkt->ifp; 265 266 KKASSERT(ro == &iproute); 267 *ro = dn_pkt->ro; /* structure copy */ 268 KKASSERT(ro->ro_rt == NULL || ro->ro_rt->rt_cpuid == mycpuid); 269 270 dst = dn_pkt->dn_dst; 271 if (dst == (struct sockaddr_in *)&(dn_pkt->ro.ro_dst)) { 272 /* If 'dst' points into dummynet tag, adjust it */ 273 dst = (struct sockaddr_in *)&(ro->ro_dst); 274 } 275 276 ip = mtod(m, struct ip *); 277 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 278 if (ro->ro_rt) 279 ia = ifatoia(ro->ro_rt->rt_ifa); 280 goto sendit; 281 } 282 283 if (opt) { 284 len = 0; 285 m = ip_insertoptions(m, opt, &len); 286 if (len != 0) 287 hlen = len; 288 } 289 ip = mtod(m, struct ip *); 290 291 /* 292 * Fill in IP header. 293 */ 294 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 295 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 296 ip->ip_off &= IP_DF; 297 ip->ip_id = ip_newid(); 298 ipstat.ips_localout++; 299 } else { 300 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 301 } 302 303 reroute: 304 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 305 306 dst = (struct sockaddr_in *)&ro->ro_dst; 307 /* 308 * If there is a cached route, 309 * check that it is to the same destination 310 * and is still up. If not, free it and try again. 311 * The address family should also be checked in case of sharing the 312 * cache with IPv6. 313 */ 314 if (ro->ro_rt && 315 (!(ro->ro_rt->rt_flags & RTF_UP) || 316 dst->sin_family != AF_INET || 317 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 318 rtfree(ro->ro_rt); 319 ro->ro_rt = NULL; 320 } 321 if (ro->ro_rt == NULL) { 322 bzero(dst, sizeof *dst); 323 dst->sin_family = AF_INET; 324 dst->sin_len = sizeof *dst; 325 dst->sin_addr = pkt_dst; 326 } 327 /* 328 * If routing to interface only, 329 * short circuit routing lookup. 330 */ 331 if (flags & IP_ROUTETOIF) { 332 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 333 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 334 ipstat.ips_noroute++; 335 error = ENETUNREACH; 336 goto bad; 337 } 338 ifp = ia->ia_ifp; 339 ip->ip_ttl = 1; 340 isbroadcast = in_broadcast(dst->sin_addr, ifp); 341 } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) && 342 imo != NULL && imo->imo_multicast_ifp != NULL) { 343 /* 344 * Bypass the normal routing lookup for multicast 345 * packets if the interface is specified. 346 */ 347 ifp = imo->imo_multicast_ifp; 348 ia = IFP_TO_IA(ifp); 349 isbroadcast = 0; /* fool gcc */ 350 } else { 351 /* 352 * If this is the case, we probably don't want to allocate 353 * a protocol-cloned route since we didn't get one from the 354 * ULP. This lets TCP do its thing, while not burdening 355 * forwarding or ICMP with the overhead of cloning a route. 356 * Of course, we still want to do any cloning requested by 357 * the link layer, as this is probably required in all cases 358 * for correct operation (as it is for ARP). 359 */ 360 if (ro->ro_rt == NULL) 361 rtalloc_ign(ro, RTF_PRCLONING); 362 if (ro->ro_rt == NULL) { 363 ipstat.ips_noroute++; 364 error = EHOSTUNREACH; 365 goto bad; 366 } 367 ia = ifatoia(ro->ro_rt->rt_ifa); 368 ifp = ro->ro_rt->rt_ifp; 369 ro->ro_rt->rt_use++; 370 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 371 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 372 if (ro->ro_rt->rt_flags & RTF_HOST) 373 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 374 else 375 isbroadcast = in_broadcast(dst->sin_addr, ifp); 376 } 377 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 378 m->m_flags |= M_MCAST; 379 /* 380 * IP destination address is multicast. Make sure "dst" 381 * still points to the address in "ro". (It may have been 382 * changed to point to a gateway address, above.) 383 */ 384 dst = (struct sockaddr_in *)&ro->ro_dst; 385 /* 386 * See if the caller provided any multicast options 387 */ 388 if (imo != NULL) { 389 ip->ip_ttl = imo->imo_multicast_ttl; 390 if (imo->imo_multicast_vif != -1) { 391 ip->ip_src.s_addr = 392 ip_mcast_src ? 393 ip_mcast_src(imo->imo_multicast_vif) : 394 INADDR_ANY; 395 } 396 } else { 397 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 398 } 399 /* 400 * Confirm that the outgoing interface supports multicast. 401 */ 402 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 403 if (!(ifp->if_flags & IFF_MULTICAST)) { 404 ipstat.ips_noroute++; 405 error = ENETUNREACH; 406 goto bad; 407 } 408 } 409 /* 410 * If source address not specified yet, use address of the 411 * outgoing interface. In case, keep note we did that, so 412 * if the the firewall changes the next-hop causing the 413 * output interface to change, we can fix that. 414 */ 415 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) { 416 /* Interface may have no addresses. */ 417 if (ia != NULL) { 418 ip->ip_src = IA_SIN(ia)->sin_addr; 419 src_was_INADDR_ANY = 1; 420 } 421 } 422 423 if (ip->ip_src.s_addr != INADDR_ANY) { 424 struct in_multi *inm; 425 426 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 427 if (inm != NULL && 428 (imo == NULL || imo->imo_multicast_loop)) { 429 /* 430 * If we belong to the destination multicast 431 * group on the outgoing interface, and the 432 * caller did not forbid loopback, loop back 433 * a copy. 434 */ 435 ip_mloopback(ifp, m, dst, hlen); 436 } else { 437 /* 438 * If we are acting as a multicast router, 439 * perform multicast forwarding as if the 440 * packet had just arrived on the interface 441 * to which we are about to send. The 442 * multicast forwarding function recursively 443 * calls this function, using the IP_FORWARDING 444 * flag to prevent infinite recursion. 445 * 446 * Multicasts that are looped back by 447 * ip_mloopback(), above, will be forwarded by 448 * the ip_input() routine, if necessary. 449 */ 450 if (ip_mrouter && !(flags & IP_FORWARDING)) { 451 /* 452 * If rsvp daemon is not running, do 453 * not set ip_moptions. This ensures 454 * that the packet is multicast and 455 * not just sent down one link as 456 * prescribed by rsvpd. 457 */ 458 if (!rsvp_on) 459 imo = NULL; 460 if (ip_mforward) { 461 get_mplock(); 462 if (ip_mforward(ip, ifp, 463 m, imo) != 0) { 464 m_freem(m); 465 rel_mplock(); 466 goto done; 467 } 468 rel_mplock(); 469 } 470 } 471 } 472 } 473 474 /* 475 * Multicasts with a time-to-live of zero may be looped- 476 * back, above, but must not be transmitted on a network. 477 * Also, multicasts addressed to the loopback interface 478 * are not sent -- the above call to ip_mloopback() will 479 * loop back a copy if this host actually belongs to the 480 * destination group on the loopback interface. 481 */ 482 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 483 m_freem(m); 484 goto done; 485 } 486 487 goto sendit; 488 } else { 489 m->m_flags &= ~M_MCAST; 490 } 491 492 /* 493 * If the source address is not specified yet, use the address 494 * of the outgoing interface. In case, keep note we did that, 495 * so if the the firewall changes the next-hop causing the output 496 * interface to change, we can fix that. 497 */ 498 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) { 499 /* Interface may have no addresses. */ 500 if (ia != NULL) { 501 ip->ip_src = IA_SIN(ia)->sin_addr; 502 src_was_INADDR_ANY = 1; 503 } 504 } 505 506 /* 507 * Look for broadcast address and 508 * verify user is allowed to send 509 * such a packet. 510 */ 511 if (isbroadcast) { 512 if (!(ifp->if_flags & IFF_BROADCAST)) { 513 error = EADDRNOTAVAIL; 514 goto bad; 515 } 516 if (!(flags & IP_ALLOWBROADCAST)) { 517 error = EACCES; 518 goto bad; 519 } 520 /* don't allow broadcast messages to be fragmented */ 521 if (ip->ip_len > ifp->if_mtu) { 522 error = EMSGSIZE; 523 goto bad; 524 } 525 m->m_flags |= M_BCAST; 526 } else { 527 m->m_flags &= ~M_BCAST; 528 } 529 530 sendit: 531 #ifdef IPSEC 532 /* get SP for this packet */ 533 if (so == NULL) 534 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 535 else 536 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 537 538 if (sp == NULL) { 539 ipsecstat.out_inval++; 540 goto bad; 541 } 542 543 error = 0; 544 545 /* check policy */ 546 switch (sp->policy) { 547 case IPSEC_POLICY_DISCARD: 548 /* 549 * This packet is just discarded. 550 */ 551 ipsecstat.out_polvio++; 552 goto bad; 553 554 case IPSEC_POLICY_BYPASS: 555 case IPSEC_POLICY_NONE: 556 case IPSEC_POLICY_TCP: 557 /* no need to do IPsec. */ 558 goto skip_ipsec; 559 560 case IPSEC_POLICY_IPSEC: 561 if (sp->req == NULL) { 562 /* acquire a policy */ 563 error = key_spdacquire(sp); 564 goto bad; 565 } 566 break; 567 568 case IPSEC_POLICY_ENTRUST: 569 default: 570 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 571 } 572 { 573 struct ipsec_output_state state; 574 bzero(&state, sizeof state); 575 state.m = m; 576 if (flags & IP_ROUTETOIF) { 577 state.ro = &iproute; 578 bzero(&iproute, sizeof iproute); 579 } else 580 state.ro = ro; 581 state.dst = (struct sockaddr *)dst; 582 583 ip->ip_sum = 0; 584 585 /* 586 * XXX 587 * delayed checksums are not currently compatible with IPsec 588 */ 589 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 590 in_delayed_cksum(m); 591 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 592 } 593 594 ip->ip_len = htons(ip->ip_len); 595 ip->ip_off = htons(ip->ip_off); 596 597 error = ipsec4_output(&state, sp, flags); 598 599 m = state.m; 600 if (flags & IP_ROUTETOIF) { 601 /* 602 * if we have tunnel mode SA, we may need to ignore 603 * IP_ROUTETOIF. 604 */ 605 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 606 flags &= ~IP_ROUTETOIF; 607 ro = state.ro; 608 } 609 } else 610 ro = state.ro; 611 dst = (struct sockaddr_in *)state.dst; 612 if (error) { 613 /* mbuf is already reclaimed in ipsec4_output. */ 614 m0 = NULL; 615 switch (error) { 616 case EHOSTUNREACH: 617 case ENETUNREACH: 618 case EMSGSIZE: 619 case ENOBUFS: 620 case ENOMEM: 621 break; 622 default: 623 kprintf("ip4_output (ipsec): error code %d\n", error); 624 /*fall through*/ 625 case ENOENT: 626 /* don't show these error codes to the user */ 627 error = 0; 628 break; 629 } 630 goto bad; 631 } 632 } 633 634 /* be sure to update variables that are affected by ipsec4_output() */ 635 ip = mtod(m, struct ip *); 636 #ifdef _IP_VHL 637 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 638 #else 639 hlen = ip->ip_hl << 2; 640 #endif 641 if (ro->ro_rt == NULL) { 642 if (!(flags & IP_ROUTETOIF)) { 643 kprintf("ip_output: " 644 "can't update route after IPsec processing\n"); 645 error = EHOSTUNREACH; /*XXX*/ 646 goto bad; 647 } 648 } else { 649 ia = ifatoia(ro->ro_rt->rt_ifa); 650 ifp = ro->ro_rt->rt_ifp; 651 } 652 653 /* make it flipped, again. */ 654 ip->ip_len = ntohs(ip->ip_len); 655 ip->ip_off = ntohs(ip->ip_off); 656 skip_ipsec: 657 #endif /*IPSEC*/ 658 #ifdef FAST_IPSEC 659 /* 660 * Check the security policy (SP) for the packet and, if 661 * required, do IPsec-related processing. There are two 662 * cases here; the first time a packet is sent through 663 * it will be untagged and handled by ipsec4_checkpolicy. 664 * If the packet is resubmitted to ip_output (e.g. after 665 * AH, ESP, etc. processing), there will be a tag to bypass 666 * the lookup and related policy checking. 667 */ 668 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 669 crit_enter(); 670 if (mtag != NULL) { 671 tdbi = (struct tdb_ident *)m_tag_data(mtag); 672 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 673 if (sp == NULL) 674 error = -EINVAL; /* force silent drop */ 675 m_tag_delete(m, mtag); 676 } else { 677 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 678 &error, inp); 679 } 680 /* 681 * There are four return cases: 682 * sp != NULL apply IPsec policy 683 * sp == NULL, error == 0 no IPsec handling needed 684 * sp == NULL, error == -EINVAL discard packet w/o error 685 * sp == NULL, error != 0 discard packet, report error 686 */ 687 if (sp != NULL) { 688 /* Loop detection, check if ipsec processing already done */ 689 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 690 for (mtag = m_tag_first(m); mtag != NULL; 691 mtag = m_tag_next(m, mtag)) { 692 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 693 continue; 694 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 695 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 696 continue; 697 /* 698 * Check if policy has an SA associated with it. 699 * This can happen when an SP has yet to acquire 700 * an SA; e.g. on first reference. If it occurs, 701 * then we let ipsec4_process_packet do its thing. 702 */ 703 if (sp->req->sav == NULL) 704 break; 705 tdbi = (struct tdb_ident *)m_tag_data(mtag); 706 if (tdbi->spi == sp->req->sav->spi && 707 tdbi->proto == sp->req->sav->sah->saidx.proto && 708 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 709 sizeof(union sockaddr_union)) == 0) { 710 /* 711 * No IPsec processing is needed, free 712 * reference to SP. 713 * 714 * NB: null pointer to avoid free at 715 * done: below. 716 */ 717 KEY_FREESP(&sp), sp = NULL; 718 crit_exit(); 719 goto spd_done; 720 } 721 } 722 723 /* 724 * Do delayed checksums now because we send before 725 * this is done in the normal processing path. 726 */ 727 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 728 in_delayed_cksum(m); 729 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 730 } 731 732 ip->ip_len = htons(ip->ip_len); 733 ip->ip_off = htons(ip->ip_off); 734 735 /* NB: callee frees mbuf */ 736 error = ipsec4_process_packet(m, sp->req, flags, 0); 737 /* 738 * Preserve KAME behaviour: ENOENT can be returned 739 * when an SA acquire is in progress. Don't propagate 740 * this to user-level; it confuses applications. 741 * 742 * XXX this will go away when the SADB is redone. 743 */ 744 if (error == ENOENT) 745 error = 0; 746 crit_exit(); 747 goto done; 748 } else { 749 crit_exit(); 750 751 if (error != 0) { 752 /* 753 * Hack: -EINVAL is used to signal that a packet 754 * should be silently discarded. This is typically 755 * because we asked key management for an SA and 756 * it was delayed (e.g. kicked up to IKE). 757 */ 758 if (error == -EINVAL) 759 error = 0; 760 goto bad; 761 } else { 762 /* No IPsec processing for this packet. */ 763 } 764 #ifdef notyet 765 /* 766 * If deferred crypto processing is needed, check that 767 * the interface supports it. 768 */ 769 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 770 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 771 /* notify IPsec to do its own crypto */ 772 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 773 error = EHOSTUNREACH; 774 goto bad; 775 } 776 #endif 777 } 778 spd_done: 779 #endif /* FAST_IPSEC */ 780 781 /* We are already being fwd'd from a firewall. */ 782 if (next_hop != NULL) 783 goto pass; 784 785 /* No pfil hooks */ 786 if (!pfil_has_hooks(&inet_pfil_hook)) { 787 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 788 /* 789 * Strip dummynet tags from stranded packets 790 */ 791 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 792 KKASSERT(mtag != NULL); 793 m_tag_delete(m, mtag); 794 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 795 } 796 goto pass; 797 } 798 799 /* 800 * IpHack's section. 801 * - Xlate: translate packet's addr/port (NAT). 802 * - Firewall: deny/allow/etc. 803 * - Wrap: fake packet's addr/port <unimpl.> 804 * - Encapsulate: put it in another IP and send out. <unimp.> 805 */ 806 807 /* 808 * Run through list of hooks for output packets. 809 */ 810 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 811 if (error != 0 || m == NULL) 812 goto done; 813 ip = mtod(m, struct ip *); 814 815 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 816 /* 817 * Check dst to make sure it is directly reachable on the 818 * interface we previously thought it was. 819 * If it isn't (which may be likely in some situations) we have 820 * to re-route it (ie, find a route for the next-hop and the 821 * associated interface) and set them here. This is nested 822 * forwarding which in most cases is undesirable, except where 823 * such control is nigh impossible. So we do it here. 824 * And I'm babbling. 825 */ 826 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 827 KKASSERT(mtag != NULL); 828 next_hop = m_tag_data(mtag); 829 830 /* 831 * Try local forwarding first 832 */ 833 if (ip_localforward(m, next_hop, hlen)) 834 goto done; 835 836 /* 837 * Relocate the route based on next_hop. 838 * If the current route is inp's cache, keep it untouched. 839 */ 840 if (ro == &iproute && ro->ro_rt != NULL) { 841 RTFREE(ro->ro_rt); 842 ro->ro_rt = NULL; 843 } 844 ro = &iproute; 845 bzero(ro, sizeof *ro); 846 847 /* 848 * Forwarding to broadcast address is not allowed. 849 * XXX Should we follow IP_ROUTETOIF? 850 */ 851 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF); 852 853 /* We are doing forwarding now */ 854 flags |= IP_FORWARDING; 855 856 goto reroute; 857 } 858 859 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 860 struct dn_pkt *dn_pkt; 861 862 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 863 KKASSERT(mtag != NULL); 864 dn_pkt = m_tag_data(mtag); 865 866 /* 867 * Under certain cases it is not possible to recalculate 868 * 'ro' and 'dst', let alone 'flags', so just save them in 869 * dummynet tag and avoid the possible wrong reculcalation 870 * when we come back to ip_output() again. 871 * 872 * All other parameters have been already used and so they 873 * are not needed anymore. 874 * XXX if the ifp is deleted while a pkt is in dummynet, 875 * we are in trouble! (TODO use ifnet_detach_event) 876 * 877 * We need to copy *ro because for ICMP pkts (and maybe 878 * others) the caller passed a pointer into the stack; 879 * dst might also be a pointer into *ro so it needs to 880 * be updated. 881 */ 882 dn_pkt->ro = *ro; 883 if (ro->ro_rt) 884 ro->ro_rt->rt_refcnt++; 885 if (dst == (struct sockaddr_in *)&ro->ro_dst) { 886 /* 'dst' points into 'ro' */ 887 dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst); 888 } 889 dn_pkt->dn_dst = dst; 890 dn_pkt->flags = flags; 891 892 ip_dn_queue(m); 893 goto done; 894 } 895 pass: 896 /* 127/8 must not appear on wire - RFC1122. */ 897 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 898 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 899 if (!(ifp->if_flags & IFF_LOOPBACK)) { 900 ipstat.ips_badaddr++; 901 error = EADDRNOTAVAIL; 902 goto bad; 903 } 904 } 905 if (ip->ip_src.s_addr == INADDR_ANY || 906 IN_MULTICAST(ntohl(ip->ip_src.s_addr))) { 907 ipstat.ips_badaddr++; 908 error = EADDRNOTAVAIL; 909 goto bad; 910 } 911 912 if ((m->m_pkthdr.csum_flags & CSUM_TSO) == 0) { 913 m->m_pkthdr.csum_flags |= CSUM_IP; 914 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 915 if (sw_csum & CSUM_DELAY_DATA) { 916 in_delayed_cksum(m); 917 sw_csum &= ~CSUM_DELAY_DATA; 918 } 919 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 920 } else { 921 sw_csum = 0; 922 } 923 m->m_pkthdr.csum_iphlen = hlen; 924 925 /* 926 * If small enough for interface, or the interface will take 927 * care of the fragmentation or segmentation for us, can just 928 * send directly. 929 */ 930 if (ip->ip_len <= ifp->if_mtu || 931 ((ifp->if_hwassist & CSUM_FRAGMENT) && !(ip->ip_off & IP_DF)) || 932 (m->m_pkthdr.csum_flags & CSUM_TSO)) { 933 ip->ip_len = htons(ip->ip_len); 934 ip->ip_off = htons(ip->ip_off); 935 ip->ip_sum = 0; 936 if (sw_csum & CSUM_DELAY_IP) { 937 if (ip->ip_vhl == IP_VHL_BORING) 938 ip->ip_sum = in_cksum_hdr(ip); 939 else 940 ip->ip_sum = in_cksum(m, hlen); 941 } 942 943 /* Record statistics for this interface address. */ 944 if (!(flags & IP_FORWARDING) && ia) { 945 IFA_STAT_INC(&ia->ia_ifa, opackets, 1); 946 IFA_STAT_INC(&ia->ia_ifa, obytes, m->m_pkthdr.len); 947 } 948 949 #ifdef IPSEC 950 /* clean ipsec history once it goes out of the node */ 951 ipsec_delaux(m); 952 #endif 953 954 #ifdef MBUF_STRESS_TEST 955 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 956 struct mbuf *m1, *m2; 957 int length, tmp; 958 959 tmp = length = m->m_pkthdr.len; 960 961 while ((length -= mbuf_frag_size) >= 1) { 962 m1 = m_split(m, length, MB_DONTWAIT); 963 if (m1 == NULL) 964 break; 965 m2 = m; 966 while (m2->m_next != NULL) 967 m2 = m2->m_next; 968 m2->m_next = m1; 969 } 970 m->m_pkthdr.len = tmp; 971 } 972 #endif 973 974 #ifdef MPLS 975 if (!mpls_output_process(m, ro->ro_rt)) 976 goto done; 977 #endif 978 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 979 ro->ro_rt); 980 goto done; 981 } 982 983 if (ip->ip_off & IP_DF) { 984 error = EMSGSIZE; 985 /* 986 * This case can happen if the user changed the MTU 987 * of an interface after enabling IP on it. Because 988 * most netifs don't keep track of routes pointing to 989 * them, there is no way for one to update all its 990 * routes when the MTU is changed. 991 */ 992 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 993 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 994 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 995 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 996 } 997 ipstat.ips_cantfrag++; 998 goto bad; 999 } 1000 1001 /* 1002 * Too large for interface; fragment if possible. If successful, 1003 * on return, m will point to a list of packets to be sent. 1004 */ 1005 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1006 if (error) 1007 goto bad; 1008 for (; m; m = m0) { 1009 m0 = m->m_nextpkt; 1010 m->m_nextpkt = NULL; 1011 #ifdef IPSEC 1012 /* clean ipsec history once it goes out of the node */ 1013 ipsec_delaux(m); 1014 #endif 1015 if (error == 0) { 1016 /* Record statistics for this interface address. */ 1017 if (ia != NULL) { 1018 IFA_STAT_INC(&ia->ia_ifa, opackets, 1); 1019 IFA_STAT_INC(&ia->ia_ifa, obytes, 1020 m->m_pkthdr.len); 1021 } 1022 #ifdef MPLS 1023 if (!mpls_output_process(m, ro->ro_rt)) 1024 continue; 1025 #endif 1026 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 1027 ro->ro_rt); 1028 } else { 1029 m_freem(m); 1030 } 1031 } 1032 1033 if (error == 0) 1034 ipstat.ips_fragmented++; 1035 1036 done: 1037 if (ro == &iproute && ro->ro_rt != NULL) { 1038 RTFREE(ro->ro_rt); 1039 ro->ro_rt = NULL; 1040 } 1041 #ifdef IPSEC 1042 if (sp != NULL) { 1043 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1044 kprintf("DP ip_output call free SP:%p\n", sp)); 1045 key_freesp(sp); 1046 } 1047 #endif 1048 #ifdef FAST_IPSEC 1049 if (sp != NULL) 1050 KEY_FREESP(&sp); 1051 #endif 1052 return (error); 1053 bad: 1054 m_freem(m); 1055 goto done; 1056 } 1057 1058 /* 1059 * Create a chain of fragments which fit the given mtu. m_frag points to the 1060 * mbuf to be fragmented; on return it points to the chain with the fragments. 1061 * Return 0 if no error. If error, m_frag may contain a partially built 1062 * chain of fragments that should be freed by the caller. 1063 * 1064 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1065 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1066 */ 1067 int 1068 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1069 u_long if_hwassist_flags, int sw_csum) 1070 { 1071 int error = 0; 1072 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1073 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1074 int off; 1075 struct mbuf *m0 = *m_frag; /* the original packet */ 1076 int firstlen; 1077 struct mbuf **mnext; 1078 int nfrags; 1079 1080 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1081 ipstat.ips_cantfrag++; 1082 return EMSGSIZE; 1083 } 1084 1085 /* 1086 * Must be able to put at least 8 bytes per fragment. 1087 */ 1088 if (len < 8) 1089 return EMSGSIZE; 1090 1091 /* 1092 * If the interface will not calculate checksums on 1093 * fragmented packets, then do it here. 1094 */ 1095 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1096 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1097 in_delayed_cksum(m0); 1098 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1099 } 1100 1101 if (len > PAGE_SIZE) { 1102 /* 1103 * Fragment large datagrams such that each segment 1104 * contains a multiple of PAGE_SIZE amount of data, 1105 * plus headers. This enables a receiver to perform 1106 * page-flipping zero-copy optimizations. 1107 * 1108 * XXX When does this help given that sender and receiver 1109 * could have different page sizes, and also mtu could 1110 * be less than the receiver's page size ? 1111 */ 1112 int newlen; 1113 struct mbuf *m; 1114 1115 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1116 off += m->m_len; 1117 1118 /* 1119 * firstlen (off - hlen) must be aligned on an 1120 * 8-byte boundary 1121 */ 1122 if (off < hlen) 1123 goto smart_frag_failure; 1124 off = ((off - hlen) & ~7) + hlen; 1125 newlen = (~PAGE_MASK) & mtu; 1126 if ((newlen + sizeof(struct ip)) > mtu) { 1127 /* we failed, go back the default */ 1128 smart_frag_failure: 1129 newlen = len; 1130 off = hlen + len; 1131 } 1132 len = newlen; 1133 1134 } else { 1135 off = hlen + len; 1136 } 1137 1138 firstlen = off - hlen; 1139 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1140 1141 /* 1142 * Loop through length of segment after first fragment, 1143 * make new header and copy data of each part and link onto chain. 1144 * Here, m0 is the original packet, m is the fragment being created. 1145 * The fragments are linked off the m_nextpkt of the original 1146 * packet, which after processing serves as the first fragment. 1147 */ 1148 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1149 struct ip *mhip; /* ip header on the fragment */ 1150 struct mbuf *m; 1151 int mhlen = sizeof(struct ip); 1152 1153 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1154 if (m == NULL) { 1155 error = ENOBUFS; 1156 ipstat.ips_odropped++; 1157 goto done; 1158 } 1159 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1160 /* 1161 * In the first mbuf, leave room for the link header, then 1162 * copy the original IP header including options. The payload 1163 * goes into an additional mbuf chain returned by m_copy(). 1164 */ 1165 m->m_data += max_linkhdr; 1166 mhip = mtod(m, struct ip *); 1167 *mhip = *ip; 1168 if (hlen > sizeof(struct ip)) { 1169 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1170 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1171 } 1172 m->m_len = mhlen; 1173 /* XXX do we need to add ip->ip_off below ? */ 1174 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1175 if (off + len >= ip->ip_len) { /* last fragment */ 1176 len = ip->ip_len - off; 1177 m->m_flags |= M_LASTFRAG; 1178 } else 1179 mhip->ip_off |= IP_MF; 1180 mhip->ip_len = htons((u_short)(len + mhlen)); 1181 m->m_next = m_copy(m0, off, len); 1182 if (m->m_next == NULL) { /* copy failed */ 1183 m_free(m); 1184 error = ENOBUFS; /* ??? */ 1185 ipstat.ips_odropped++; 1186 goto done; 1187 } 1188 m->m_pkthdr.len = mhlen + len; 1189 m->m_pkthdr.rcvif = NULL; 1190 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1191 m->m_pkthdr.csum_iphlen = mhlen; 1192 mhip->ip_off = htons(mhip->ip_off); 1193 mhip->ip_sum = 0; 1194 if (sw_csum & CSUM_DELAY_IP) 1195 mhip->ip_sum = in_cksum(m, mhlen); 1196 *mnext = m; 1197 mnext = &m->m_nextpkt; 1198 } 1199 ipstat.ips_ofragments += nfrags; 1200 1201 /* set first marker for fragment chain */ 1202 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1203 m0->m_pkthdr.csum_data = nfrags; 1204 1205 /* 1206 * Update first fragment by trimming what's been copied out 1207 * and updating header. 1208 */ 1209 m_adj(m0, hlen + firstlen - ip->ip_len); 1210 m0->m_pkthdr.len = hlen + firstlen; 1211 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1212 ip->ip_off |= IP_MF; 1213 ip->ip_off = htons(ip->ip_off); 1214 ip->ip_sum = 0; 1215 if (sw_csum & CSUM_DELAY_IP) 1216 ip->ip_sum = in_cksum(m0, hlen); 1217 1218 done: 1219 *m_frag = m0; 1220 return error; 1221 } 1222 1223 void 1224 in_delayed_cksum(struct mbuf *m) 1225 { 1226 struct ip *ip; 1227 u_short csum, offset; 1228 1229 ip = mtod(m, struct ip *); 1230 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1231 csum = in_cksum_skip(m, ip->ip_len, offset); 1232 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1233 csum = 0xffff; 1234 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1235 1236 if (offset + sizeof(u_short) > m->m_len) { 1237 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1238 m->m_len, offset, ip->ip_p); 1239 /* 1240 * XXX 1241 * this shouldn't happen, but if it does, the 1242 * correct behavior may be to insert the checksum 1243 * in the existing chain instead of rearranging it. 1244 */ 1245 m = m_pullup(m, offset + sizeof(u_short)); 1246 } 1247 *(u_short *)(m->m_data + offset) = csum; 1248 } 1249 1250 /* 1251 * Insert IP options into preformed packet. 1252 * Adjust IP destination as required for IP source routing, 1253 * as indicated by a non-zero in_addr at the start of the options. 1254 * 1255 * XXX This routine assumes that the packet has no options in place. 1256 */ 1257 static struct mbuf * 1258 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1259 { 1260 struct ipoption *p = mtod(opt, struct ipoption *); 1261 struct mbuf *n; 1262 struct ip *ip = mtod(m, struct ip *); 1263 unsigned optlen; 1264 1265 optlen = opt->m_len - sizeof p->ipopt_dst; 1266 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1267 *phlen = 0; 1268 return (m); /* XXX should fail */ 1269 } 1270 if (p->ipopt_dst.s_addr) 1271 ip->ip_dst = p->ipopt_dst; 1272 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1273 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1274 if (n == NULL) { 1275 *phlen = 0; 1276 return (m); 1277 } 1278 n->m_pkthdr.rcvif = NULL; 1279 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1280 m->m_len -= sizeof(struct ip); 1281 m->m_data += sizeof(struct ip); 1282 n->m_next = m; 1283 m = n; 1284 m->m_len = optlen + sizeof(struct ip); 1285 m->m_data += max_linkhdr; 1286 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1287 } else { 1288 m->m_data -= optlen; 1289 m->m_len += optlen; 1290 m->m_pkthdr.len += optlen; 1291 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1292 } 1293 ip = mtod(m, struct ip *); 1294 bcopy(p->ipopt_list, ip + 1, optlen); 1295 *phlen = sizeof(struct ip) + optlen; 1296 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1297 ip->ip_len += optlen; 1298 return (m); 1299 } 1300 1301 /* 1302 * Copy options from ip to jp, 1303 * omitting those not copied during fragmentation. 1304 */ 1305 int 1306 ip_optcopy(struct ip *ip, struct ip *jp) 1307 { 1308 u_char *cp, *dp; 1309 int opt, optlen, cnt; 1310 1311 cp = (u_char *)(ip + 1); 1312 dp = (u_char *)(jp + 1); 1313 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1314 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1315 opt = cp[0]; 1316 if (opt == IPOPT_EOL) 1317 break; 1318 if (opt == IPOPT_NOP) { 1319 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1320 *dp++ = IPOPT_NOP; 1321 optlen = 1; 1322 continue; 1323 } 1324 1325 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1326 ("ip_optcopy: malformed ipv4 option")); 1327 optlen = cp[IPOPT_OLEN]; 1328 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1329 ("ip_optcopy: malformed ipv4 option")); 1330 1331 /* bogus lengths should have been caught by ip_dooptions */ 1332 if (optlen > cnt) 1333 optlen = cnt; 1334 if (IPOPT_COPIED(opt)) { 1335 bcopy(cp, dp, optlen); 1336 dp += optlen; 1337 } 1338 } 1339 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1340 *dp++ = IPOPT_EOL; 1341 return (optlen); 1342 } 1343 1344 /* 1345 * IP socket option processing. 1346 */ 1347 void 1348 ip_ctloutput(netmsg_t msg) 1349 { 1350 struct socket *so = msg->base.nm_so; 1351 struct sockopt *sopt = msg->ctloutput.nm_sopt; 1352 struct inpcb *inp = so->so_pcb; 1353 int error, optval; 1354 1355 error = optval = 0; 1356 if (sopt->sopt_level != IPPROTO_IP) { 1357 error = EINVAL; 1358 goto done; 1359 } 1360 1361 switch (sopt->sopt_dir) { 1362 case SOPT_SET: 1363 switch (sopt->sopt_name) { 1364 case IP_OPTIONS: 1365 #ifdef notyet 1366 case IP_RETOPTS: 1367 #endif 1368 { 1369 struct mbuf *m; 1370 if (sopt->sopt_valsize > MLEN) { 1371 error = EMSGSIZE; 1372 break; 1373 } 1374 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1375 if (m == NULL) { 1376 error = ENOBUFS; 1377 break; 1378 } 1379 m->m_len = sopt->sopt_valsize; 1380 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len, 1381 m->m_len); 1382 error = ip_pcbopts(sopt->sopt_name, 1383 &inp->inp_options, m); 1384 goto done; 1385 } 1386 1387 case IP_TOS: 1388 case IP_TTL: 1389 case IP_MINTTL: 1390 case IP_RECVOPTS: 1391 case IP_RECVRETOPTS: 1392 case IP_RECVDSTADDR: 1393 case IP_RECVIF: 1394 case IP_RECVTTL: 1395 case IP_FAITH: 1396 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1397 sizeof optval); 1398 if (error) 1399 break; 1400 switch (sopt->sopt_name) { 1401 case IP_TOS: 1402 inp->inp_ip_tos = optval; 1403 break; 1404 1405 case IP_TTL: 1406 inp->inp_ip_ttl = optval; 1407 break; 1408 case IP_MINTTL: 1409 if (optval >= 0 && optval <= MAXTTL) 1410 inp->inp_ip_minttl = optval; 1411 else 1412 error = EINVAL; 1413 break; 1414 #define OPTSET(bit) \ 1415 if (optval) \ 1416 inp->inp_flags |= bit; \ 1417 else \ 1418 inp->inp_flags &= ~bit; 1419 1420 case IP_RECVOPTS: 1421 OPTSET(INP_RECVOPTS); 1422 break; 1423 1424 case IP_RECVRETOPTS: 1425 OPTSET(INP_RECVRETOPTS); 1426 break; 1427 1428 case IP_RECVDSTADDR: 1429 OPTSET(INP_RECVDSTADDR); 1430 break; 1431 1432 case IP_RECVIF: 1433 OPTSET(INP_RECVIF); 1434 break; 1435 1436 case IP_RECVTTL: 1437 OPTSET(INP_RECVTTL); 1438 break; 1439 1440 case IP_FAITH: 1441 OPTSET(INP_FAITH); 1442 break; 1443 } 1444 break; 1445 #undef OPTSET 1446 1447 case IP_MULTICAST_IF: 1448 case IP_MULTICAST_VIF: 1449 case IP_MULTICAST_TTL: 1450 case IP_MULTICAST_LOOP: 1451 case IP_ADD_MEMBERSHIP: 1452 case IP_DROP_MEMBERSHIP: 1453 error = ip_setmoptions(sopt, &inp->inp_moptions); 1454 break; 1455 1456 case IP_PORTRANGE: 1457 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1458 sizeof optval); 1459 if (error) 1460 break; 1461 1462 switch (optval) { 1463 case IP_PORTRANGE_DEFAULT: 1464 inp->inp_flags &= ~(INP_LOWPORT); 1465 inp->inp_flags &= ~(INP_HIGHPORT); 1466 break; 1467 1468 case IP_PORTRANGE_HIGH: 1469 inp->inp_flags &= ~(INP_LOWPORT); 1470 inp->inp_flags |= INP_HIGHPORT; 1471 break; 1472 1473 case IP_PORTRANGE_LOW: 1474 inp->inp_flags &= ~(INP_HIGHPORT); 1475 inp->inp_flags |= INP_LOWPORT; 1476 break; 1477 1478 default: 1479 error = EINVAL; 1480 break; 1481 } 1482 break; 1483 1484 #if defined(IPSEC) || defined(FAST_IPSEC) 1485 case IP_IPSEC_POLICY: 1486 { 1487 caddr_t req; 1488 size_t len = 0; 1489 int priv; 1490 struct mbuf *m; 1491 int optname; 1492 1493 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1494 break; 1495 soopt_to_mbuf(sopt, m); 1496 priv = (sopt->sopt_td != NULL && 1497 priv_check(sopt->sopt_td, PRIV_ROOT) != 0) ? 0 : 1; 1498 req = mtod(m, caddr_t); 1499 len = m->m_len; 1500 optname = sopt->sopt_name; 1501 error = ipsec4_set_policy(inp, optname, req, len, priv); 1502 m_freem(m); 1503 break; 1504 } 1505 #endif /*IPSEC*/ 1506 1507 default: 1508 error = ENOPROTOOPT; 1509 break; 1510 } 1511 break; 1512 1513 case SOPT_GET: 1514 switch (sopt->sopt_name) { 1515 case IP_OPTIONS: 1516 case IP_RETOPTS: 1517 if (inp->inp_options) 1518 soopt_from_kbuf(sopt, mtod(inp->inp_options, 1519 char *), 1520 inp->inp_options->m_len); 1521 else 1522 sopt->sopt_valsize = 0; 1523 break; 1524 1525 case IP_TOS: 1526 case IP_TTL: 1527 case IP_MINTTL: 1528 case IP_RECVOPTS: 1529 case IP_RECVRETOPTS: 1530 case IP_RECVDSTADDR: 1531 case IP_RECVTTL: 1532 case IP_RECVIF: 1533 case IP_PORTRANGE: 1534 case IP_FAITH: 1535 switch (sopt->sopt_name) { 1536 1537 case IP_TOS: 1538 optval = inp->inp_ip_tos; 1539 break; 1540 1541 case IP_TTL: 1542 optval = inp->inp_ip_ttl; 1543 break; 1544 case IP_MINTTL: 1545 optval = inp->inp_ip_minttl; 1546 break; 1547 1548 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1549 1550 case IP_RECVOPTS: 1551 optval = OPTBIT(INP_RECVOPTS); 1552 break; 1553 1554 case IP_RECVRETOPTS: 1555 optval = OPTBIT(INP_RECVRETOPTS); 1556 break; 1557 1558 case IP_RECVDSTADDR: 1559 optval = OPTBIT(INP_RECVDSTADDR); 1560 break; 1561 1562 case IP_RECVTTL: 1563 optval = OPTBIT(INP_RECVTTL); 1564 break; 1565 1566 case IP_RECVIF: 1567 optval = OPTBIT(INP_RECVIF); 1568 break; 1569 1570 case IP_PORTRANGE: 1571 if (inp->inp_flags & INP_HIGHPORT) 1572 optval = IP_PORTRANGE_HIGH; 1573 else if (inp->inp_flags & INP_LOWPORT) 1574 optval = IP_PORTRANGE_LOW; 1575 else 1576 optval = 0; 1577 break; 1578 1579 case IP_FAITH: 1580 optval = OPTBIT(INP_FAITH); 1581 break; 1582 } 1583 soopt_from_kbuf(sopt, &optval, sizeof optval); 1584 break; 1585 1586 case IP_MULTICAST_IF: 1587 case IP_MULTICAST_VIF: 1588 case IP_MULTICAST_TTL: 1589 case IP_MULTICAST_LOOP: 1590 case IP_ADD_MEMBERSHIP: 1591 case IP_DROP_MEMBERSHIP: 1592 error = ip_getmoptions(sopt, inp->inp_moptions); 1593 break; 1594 1595 #if defined(IPSEC) || defined(FAST_IPSEC) 1596 case IP_IPSEC_POLICY: 1597 { 1598 struct mbuf *m = NULL; 1599 caddr_t req = NULL; 1600 size_t len = 0; 1601 1602 if (m != NULL) { 1603 req = mtod(m, caddr_t); 1604 len = m->m_len; 1605 } 1606 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1607 if (error == 0) 1608 error = soopt_from_mbuf(sopt, m); /* XXX */ 1609 if (error == 0) 1610 m_freem(m); 1611 break; 1612 } 1613 #endif /*IPSEC*/ 1614 1615 default: 1616 error = ENOPROTOOPT; 1617 break; 1618 } 1619 break; 1620 } 1621 done: 1622 lwkt_replymsg(&msg->lmsg, error); 1623 } 1624 1625 /* 1626 * Set up IP options in pcb for insertion in output packets. 1627 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1628 * with destination address if source routed. 1629 */ 1630 static int 1631 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1632 { 1633 int cnt, optlen; 1634 u_char *cp; 1635 u_char opt; 1636 1637 /* turn off any old options */ 1638 if (*pcbopt) 1639 m_free(*pcbopt); 1640 *pcbopt = NULL; 1641 if (m == NULL || m->m_len == 0) { 1642 /* 1643 * Only turning off any previous options. 1644 */ 1645 if (m != NULL) 1646 m_free(m); 1647 return (0); 1648 } 1649 1650 if (m->m_len % sizeof(int32_t)) 1651 goto bad; 1652 /* 1653 * IP first-hop destination address will be stored before 1654 * actual options; move other options back 1655 * and clear it when none present. 1656 */ 1657 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1658 goto bad; 1659 cnt = m->m_len; 1660 m->m_len += sizeof(struct in_addr); 1661 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1662 ovbcopy(mtod(m, caddr_t), cp, cnt); 1663 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1664 1665 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1666 opt = cp[IPOPT_OPTVAL]; 1667 if (opt == IPOPT_EOL) 1668 break; 1669 if (opt == IPOPT_NOP) 1670 optlen = 1; 1671 else { 1672 if (cnt < IPOPT_OLEN + sizeof *cp) 1673 goto bad; 1674 optlen = cp[IPOPT_OLEN]; 1675 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1676 goto bad; 1677 } 1678 switch (opt) { 1679 1680 default: 1681 break; 1682 1683 case IPOPT_LSRR: 1684 case IPOPT_SSRR: 1685 /* 1686 * user process specifies route as: 1687 * ->A->B->C->D 1688 * D must be our final destination (but we can't 1689 * check that since we may not have connected yet). 1690 * A is first hop destination, which doesn't appear in 1691 * actual IP option, but is stored before the options. 1692 */ 1693 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1694 goto bad; 1695 m->m_len -= sizeof(struct in_addr); 1696 cnt -= sizeof(struct in_addr); 1697 optlen -= sizeof(struct in_addr); 1698 cp[IPOPT_OLEN] = optlen; 1699 /* 1700 * Move first hop before start of options. 1701 */ 1702 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1703 sizeof(struct in_addr)); 1704 /* 1705 * Then copy rest of options back 1706 * to close up the deleted entry. 1707 */ 1708 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1709 &cp[IPOPT_OFFSET+1], 1710 cnt - (IPOPT_MINOFF - 1)); 1711 break; 1712 } 1713 } 1714 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1715 goto bad; 1716 *pcbopt = m; 1717 return (0); 1718 1719 bad: 1720 m_free(m); 1721 return (EINVAL); 1722 } 1723 1724 /* 1725 * XXX 1726 * The whole multicast option thing needs to be re-thought. 1727 * Several of these options are equally applicable to non-multicast 1728 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1729 * standard option (IP_TTL). 1730 */ 1731 1732 /* 1733 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1734 */ 1735 static struct ifnet * 1736 ip_multicast_if(struct in_addr *a, int *ifindexp) 1737 { 1738 int ifindex; 1739 struct ifnet *ifp; 1740 1741 if (ifindexp) 1742 *ifindexp = 0; 1743 if (ntohl(a->s_addr) >> 24 == 0) { 1744 ifindex = ntohl(a->s_addr) & 0xffffff; 1745 if (ifindex < 0 || if_index < ifindex) 1746 return NULL; 1747 ifp = ifindex2ifnet[ifindex]; 1748 if (ifindexp) 1749 *ifindexp = ifindex; 1750 } else { 1751 ifp = INADDR_TO_IFP(a); 1752 } 1753 return ifp; 1754 } 1755 1756 /* 1757 * Set the IP multicast options in response to user setsockopt(). 1758 */ 1759 static int 1760 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1761 { 1762 int error = 0; 1763 int i; 1764 struct in_addr addr; 1765 struct ip_mreq mreq; 1766 struct ifnet *ifp; 1767 struct ip_moptions *imo = *imop; 1768 int ifindex; 1769 1770 if (imo == NULL) { 1771 /* 1772 * No multicast option buffer attached to the pcb; 1773 * allocate one and initialize to default values. 1774 */ 1775 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1776 1777 *imop = imo; 1778 imo->imo_multicast_ifp = NULL; 1779 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1780 imo->imo_multicast_vif = -1; 1781 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1782 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1783 imo->imo_num_memberships = 0; 1784 } 1785 switch (sopt->sopt_name) { 1786 /* store an index number for the vif you wanna use in the send */ 1787 case IP_MULTICAST_VIF: 1788 if (legal_vif_num == 0) { 1789 error = EOPNOTSUPP; 1790 break; 1791 } 1792 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i); 1793 if (error) 1794 break; 1795 if (!legal_vif_num(i) && (i != -1)) { 1796 error = EINVAL; 1797 break; 1798 } 1799 imo->imo_multicast_vif = i; 1800 break; 1801 1802 case IP_MULTICAST_IF: 1803 /* 1804 * Select the interface for outgoing multicast packets. 1805 */ 1806 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr); 1807 if (error) 1808 break; 1809 1810 /* 1811 * INADDR_ANY is used to remove a previous selection. 1812 * When no interface is selected, a default one is 1813 * chosen every time a multicast packet is sent. 1814 */ 1815 if (addr.s_addr == INADDR_ANY) { 1816 imo->imo_multicast_ifp = NULL; 1817 break; 1818 } 1819 /* 1820 * The selected interface is identified by its local 1821 * IP address. Find the interface and confirm that 1822 * it supports multicasting. 1823 */ 1824 crit_enter(); 1825 ifp = ip_multicast_if(&addr, &ifindex); 1826 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1827 crit_exit(); 1828 error = EADDRNOTAVAIL; 1829 break; 1830 } 1831 imo->imo_multicast_ifp = ifp; 1832 if (ifindex) 1833 imo->imo_multicast_addr = addr; 1834 else 1835 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1836 crit_exit(); 1837 break; 1838 1839 case IP_MULTICAST_TTL: 1840 /* 1841 * Set the IP time-to-live for outgoing multicast packets. 1842 * The original multicast API required a char argument, 1843 * which is inconsistent with the rest of the socket API. 1844 * We allow either a char or an int. 1845 */ 1846 if (sopt->sopt_valsize == 1) { 1847 u_char ttl; 1848 error = soopt_to_kbuf(sopt, &ttl, 1, 1); 1849 if (error) 1850 break; 1851 imo->imo_multicast_ttl = ttl; 1852 } else { 1853 u_int ttl; 1854 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl); 1855 if (error) 1856 break; 1857 if (ttl > 255) 1858 error = EINVAL; 1859 else 1860 imo->imo_multicast_ttl = ttl; 1861 } 1862 break; 1863 1864 case IP_MULTICAST_LOOP: 1865 /* 1866 * Set the loopback flag for outgoing multicast packets. 1867 * Must be zero or one. The original multicast API required a 1868 * char argument, which is inconsistent with the rest 1869 * of the socket API. We allow either a char or an int. 1870 */ 1871 if (sopt->sopt_valsize == 1) { 1872 u_char loop; 1873 1874 error = soopt_to_kbuf(sopt, &loop, 1, 1); 1875 if (error) 1876 break; 1877 imo->imo_multicast_loop = !!loop; 1878 } else { 1879 u_int loop; 1880 1881 error = soopt_to_kbuf(sopt, &loop, sizeof loop, 1882 sizeof loop); 1883 if (error) 1884 break; 1885 imo->imo_multicast_loop = !!loop; 1886 } 1887 break; 1888 1889 case IP_ADD_MEMBERSHIP: 1890 /* 1891 * Add a multicast group membership. 1892 * Group must be a valid IP multicast address. 1893 */ 1894 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1895 if (error) 1896 break; 1897 1898 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1899 error = EINVAL; 1900 break; 1901 } 1902 crit_enter(); 1903 /* 1904 * If no interface address was provided, use the interface of 1905 * the route to the given multicast address. 1906 */ 1907 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1908 struct sockaddr_in dst; 1909 struct rtentry *rt; 1910 1911 bzero(&dst, sizeof(struct sockaddr_in)); 1912 dst.sin_len = sizeof(struct sockaddr_in); 1913 dst.sin_family = AF_INET; 1914 dst.sin_addr = mreq.imr_multiaddr; 1915 rt = rtlookup((struct sockaddr *)&dst); 1916 if (rt == NULL) { 1917 error = EADDRNOTAVAIL; 1918 crit_exit(); 1919 break; 1920 } 1921 --rt->rt_refcnt; 1922 ifp = rt->rt_ifp; 1923 } else { 1924 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1925 } 1926 1927 /* 1928 * See if we found an interface, and confirm that it 1929 * supports multicast. 1930 */ 1931 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1932 error = EADDRNOTAVAIL; 1933 crit_exit(); 1934 break; 1935 } 1936 /* 1937 * See if the membership already exists or if all the 1938 * membership slots are full. 1939 */ 1940 for (i = 0; i < imo->imo_num_memberships; ++i) { 1941 if (imo->imo_membership[i]->inm_ifp == ifp && 1942 imo->imo_membership[i]->inm_addr.s_addr 1943 == mreq.imr_multiaddr.s_addr) 1944 break; 1945 } 1946 if (i < imo->imo_num_memberships) { 1947 error = EADDRINUSE; 1948 crit_exit(); 1949 break; 1950 } 1951 if (i == IP_MAX_MEMBERSHIPS) { 1952 error = ETOOMANYREFS; 1953 crit_exit(); 1954 break; 1955 } 1956 /* 1957 * Everything looks good; add a new record to the multicast 1958 * address list for the given interface. 1959 */ 1960 if ((imo->imo_membership[i] = 1961 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1962 error = ENOBUFS; 1963 crit_exit(); 1964 break; 1965 } 1966 ++imo->imo_num_memberships; 1967 crit_exit(); 1968 break; 1969 1970 case IP_DROP_MEMBERSHIP: 1971 /* 1972 * Drop a multicast group membership. 1973 * Group must be a valid IP multicast address. 1974 */ 1975 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1976 if (error) 1977 break; 1978 1979 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1980 error = EINVAL; 1981 break; 1982 } 1983 1984 crit_enter(); 1985 /* 1986 * If an interface address was specified, get a pointer 1987 * to its ifnet structure. 1988 */ 1989 if (mreq.imr_interface.s_addr == INADDR_ANY) 1990 ifp = NULL; 1991 else { 1992 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1993 if (ifp == NULL) { 1994 error = EADDRNOTAVAIL; 1995 crit_exit(); 1996 break; 1997 } 1998 } 1999 /* 2000 * Find the membership in the membership array. 2001 */ 2002 for (i = 0; i < imo->imo_num_memberships; ++i) { 2003 if ((ifp == NULL || 2004 imo->imo_membership[i]->inm_ifp == ifp) && 2005 imo->imo_membership[i]->inm_addr.s_addr == 2006 mreq.imr_multiaddr.s_addr) 2007 break; 2008 } 2009 if (i == imo->imo_num_memberships) { 2010 error = EADDRNOTAVAIL; 2011 crit_exit(); 2012 break; 2013 } 2014 /* 2015 * Give up the multicast address record to which the 2016 * membership points. 2017 */ 2018 in_delmulti(imo->imo_membership[i]); 2019 /* 2020 * Remove the gap in the membership array. 2021 */ 2022 for (++i; i < imo->imo_num_memberships; ++i) 2023 imo->imo_membership[i-1] = imo->imo_membership[i]; 2024 --imo->imo_num_memberships; 2025 crit_exit(); 2026 break; 2027 2028 default: 2029 error = EOPNOTSUPP; 2030 break; 2031 } 2032 2033 /* 2034 * If all options have default values, no need to keep the mbuf. 2035 */ 2036 if (imo->imo_multicast_ifp == NULL && 2037 imo->imo_multicast_vif == -1 && 2038 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2039 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2040 imo->imo_num_memberships == 0) { 2041 kfree(*imop, M_IPMOPTS); 2042 *imop = NULL; 2043 } 2044 2045 return (error); 2046 } 2047 2048 /* 2049 * Return the IP multicast options in response to user getsockopt(). 2050 */ 2051 static int 2052 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2053 { 2054 struct in_addr addr; 2055 struct in_ifaddr *ia; 2056 int error, optval; 2057 u_char coptval; 2058 2059 error = 0; 2060 switch (sopt->sopt_name) { 2061 case IP_MULTICAST_VIF: 2062 if (imo != NULL) 2063 optval = imo->imo_multicast_vif; 2064 else 2065 optval = -1; 2066 soopt_from_kbuf(sopt, &optval, sizeof optval); 2067 break; 2068 2069 case IP_MULTICAST_IF: 2070 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2071 addr.s_addr = INADDR_ANY; 2072 else if (imo->imo_multicast_addr.s_addr) { 2073 /* return the value user has set */ 2074 addr = imo->imo_multicast_addr; 2075 } else { 2076 ia = IFP_TO_IA(imo->imo_multicast_ifp); 2077 addr.s_addr = (ia == NULL) ? INADDR_ANY 2078 : IA_SIN(ia)->sin_addr.s_addr; 2079 } 2080 soopt_from_kbuf(sopt, &addr, sizeof addr); 2081 break; 2082 2083 case IP_MULTICAST_TTL: 2084 if (imo == NULL) 2085 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2086 else 2087 optval = coptval = imo->imo_multicast_ttl; 2088 if (sopt->sopt_valsize == 1) 2089 soopt_from_kbuf(sopt, &coptval, 1); 2090 else 2091 soopt_from_kbuf(sopt, &optval, sizeof optval); 2092 break; 2093 2094 case IP_MULTICAST_LOOP: 2095 if (imo == NULL) 2096 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2097 else 2098 optval = coptval = imo->imo_multicast_loop; 2099 if (sopt->sopt_valsize == 1) 2100 soopt_from_kbuf(sopt, &coptval, 1); 2101 else 2102 soopt_from_kbuf(sopt, &optval, sizeof optval); 2103 break; 2104 2105 default: 2106 error = ENOPROTOOPT; 2107 break; 2108 } 2109 return (error); 2110 } 2111 2112 /* 2113 * Discard the IP multicast options. 2114 */ 2115 void 2116 ip_freemoptions(struct ip_moptions *imo) 2117 { 2118 int i; 2119 2120 if (imo != NULL) { 2121 for (i = 0; i < imo->imo_num_memberships; ++i) 2122 in_delmulti(imo->imo_membership[i]); 2123 kfree(imo, M_IPMOPTS); 2124 } 2125 } 2126 2127 /* 2128 * Routine called from ip_output() to loop back a copy of an IP multicast 2129 * packet to the input queue of a specified interface. Note that this 2130 * calls the output routine of the loopback "driver", but with an interface 2131 * pointer that might NOT be a loopback interface -- evil, but easier than 2132 * replicating that code here. 2133 */ 2134 static void 2135 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2136 int hlen) 2137 { 2138 struct ip *ip; 2139 struct mbuf *copym; 2140 2141 copym = m_copypacket(m, MB_DONTWAIT); 2142 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2143 copym = m_pullup(copym, hlen); 2144 if (copym != NULL) { 2145 /* 2146 * if the checksum hasn't been computed, mark it as valid 2147 */ 2148 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2149 in_delayed_cksum(copym); 2150 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2151 copym->m_pkthdr.csum_flags |= 2152 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2153 copym->m_pkthdr.csum_data = 0xffff; 2154 } 2155 /* 2156 * We don't bother to fragment if the IP length is greater 2157 * than the interface's MTU. Can this possibly matter? 2158 */ 2159 ip = mtod(copym, struct ip *); 2160 ip->ip_len = htons(ip->ip_len); 2161 ip->ip_off = htons(ip->ip_off); 2162 ip->ip_sum = 0; 2163 if (ip->ip_vhl == IP_VHL_BORING) { 2164 ip->ip_sum = in_cksum_hdr(ip); 2165 } else { 2166 ip->ip_sum = in_cksum(copym, hlen); 2167 } 2168 /* 2169 * NB: 2170 * It's not clear whether there are any lingering 2171 * reentrancy problems in other areas which might 2172 * be exposed by using ip_input directly (in 2173 * particular, everything which modifies the packet 2174 * in-place). Yet another option is using the 2175 * protosw directly to deliver the looped back 2176 * packet. For the moment, we'll err on the side 2177 * of safety by using if_simloop(). 2178 */ 2179 #if 1 /* XXX */ 2180 if (dst->sin_family != AF_INET) { 2181 kprintf("ip_mloopback: bad address family %d\n", 2182 dst->sin_family); 2183 dst->sin_family = AF_INET; 2184 } 2185 #endif 2186 get_mplock(); /* is if_simloop() mpsafe yet? */ 2187 if_simloop(ifp, copym, dst->sin_family, 0); 2188 rel_mplock(); 2189 } 2190 } 2191