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 1.67 2008/10/28 03:07:28 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 #include "opt_mpls.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/proc.h> 53 #include <sys/priv.h> 54 #include <sys/sysctl.h> 55 #include <sys/thread2.h> 56 #include <sys/in_cksum.h> 57 #include <sys/lock.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(); 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 #ifdef INVARIANTS 307 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 308 /* 309 * XXX 310 * Multicast is not MPSAFE yet. Caller must hold 311 * BGL when output a multicast IP packet. 312 */ 313 ASSERT_MP_LOCK_HELD(curthread); 314 } 315 #endif 316 317 dst = (struct sockaddr_in *)&ro->ro_dst; 318 /* 319 * If there is a cached route, 320 * check that it is to the same destination 321 * and is still up. If not, free it and try again. 322 * The address family should also be checked in case of sharing the 323 * cache with IPv6. 324 */ 325 if (ro->ro_rt && 326 (!(ro->ro_rt->rt_flags & RTF_UP) || 327 dst->sin_family != AF_INET || 328 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 329 rtfree(ro->ro_rt); 330 ro->ro_rt = (struct rtentry *)NULL; 331 } 332 if (ro->ro_rt == NULL) { 333 bzero(dst, sizeof *dst); 334 dst->sin_family = AF_INET; 335 dst->sin_len = sizeof *dst; 336 dst->sin_addr = pkt_dst; 337 } 338 /* 339 * If routing to interface only, 340 * short circuit routing lookup. 341 */ 342 if (flags & IP_ROUTETOIF) { 343 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 344 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 345 ipstat.ips_noroute++; 346 error = ENETUNREACH; 347 goto bad; 348 } 349 ifp = ia->ia_ifp; 350 ip->ip_ttl = 1; 351 isbroadcast = in_broadcast(dst->sin_addr, ifp); 352 } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) && 353 imo != NULL && imo->imo_multicast_ifp != NULL) { 354 /* 355 * Bypass the normal routing lookup for multicast 356 * packets if the interface is specified. 357 */ 358 ifp = imo->imo_multicast_ifp; 359 ia = IFP_TO_IA(ifp); 360 isbroadcast = 0; /* fool gcc */ 361 } else { 362 /* 363 * If this is the case, we probably don't want to allocate 364 * a protocol-cloned route since we didn't get one from the 365 * ULP. This lets TCP do its thing, while not burdening 366 * forwarding or ICMP with the overhead of cloning a route. 367 * Of course, we still want to do any cloning requested by 368 * the link layer, as this is probably required in all cases 369 * for correct operation (as it is for ARP). 370 */ 371 if (ro->ro_rt == NULL) 372 rtalloc_ign(ro, RTF_PRCLONING); 373 if (ro->ro_rt == NULL) { 374 ipstat.ips_noroute++; 375 error = EHOSTUNREACH; 376 goto bad; 377 } 378 ia = ifatoia(ro->ro_rt->rt_ifa); 379 ifp = ro->ro_rt->rt_ifp; 380 ro->ro_rt->rt_use++; 381 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 382 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 383 if (ro->ro_rt->rt_flags & RTF_HOST) 384 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 385 else 386 isbroadcast = in_broadcast(dst->sin_addr, ifp); 387 } 388 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 389 struct in_multi *inm; 390 391 m->m_flags |= M_MCAST; 392 /* 393 * IP destination address is multicast. Make sure "dst" 394 * still points to the address in "ro". (It may have been 395 * changed to point to a gateway address, above.) 396 */ 397 dst = (struct sockaddr_in *)&ro->ro_dst; 398 /* 399 * See if the caller provided any multicast options 400 */ 401 if (imo != NULL) { 402 ip->ip_ttl = imo->imo_multicast_ttl; 403 if (imo->imo_multicast_vif != -1) { 404 ip->ip_src.s_addr = 405 ip_mcast_src ? 406 ip_mcast_src(imo->imo_multicast_vif) : 407 INADDR_ANY; 408 } 409 } else { 410 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 411 } 412 /* 413 * Confirm that the outgoing interface supports multicast. 414 */ 415 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 416 if (!(ifp->if_flags & IFF_MULTICAST)) { 417 ipstat.ips_noroute++; 418 error = ENETUNREACH; 419 goto bad; 420 } 421 } 422 /* 423 * If source address not specified yet, use address 424 * of outgoing interface. 425 */ 426 if (ip->ip_src.s_addr == INADDR_ANY) { 427 /* Interface may have no addresses. */ 428 if (ia != NULL) 429 ip->ip_src = IA_SIN(ia)->sin_addr; 430 } 431 432 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 433 if (inm != NULL && 434 (imo == NULL || imo->imo_multicast_loop)) { 435 /* 436 * If we belong to the destination multicast group 437 * on the outgoing interface, and the caller did not 438 * forbid loopback, loop back a copy. 439 */ 440 ip_mloopback(ifp, m, dst, hlen); 441 } else { 442 /* 443 * If we are acting as a multicast router, perform 444 * multicast forwarding as if the packet had just 445 * arrived on the interface to which we are about 446 * to send. The multicast forwarding function 447 * recursively calls this function, using the 448 * IP_FORWARDING flag to prevent infinite recursion. 449 * 450 * Multicasts that are looped back by ip_mloopback(), 451 * above, will be forwarded by the ip_input() routine, 452 * if necessary. 453 */ 454 if (ip_mrouter && !(flags & IP_FORWARDING)) { 455 /* 456 * If rsvp daemon is not running, do not 457 * set ip_moptions. This ensures that the packet 458 * is multicast and not just sent down one link 459 * as prescribed by rsvpd. 460 */ 461 if (!rsvp_on) 462 imo = NULL; 463 if (ip_mforward && 464 ip_mforward(ip, ifp, m, imo) != 0) { 465 m_freem(m); 466 goto done; 467 } 468 } 469 } 470 471 /* 472 * Multicasts with a time-to-live of zero may be looped- 473 * back, above, but must not be transmitted on a network. 474 * Also, multicasts addressed to the loopback interface 475 * are not sent -- the above call to ip_mloopback() will 476 * loop back a copy if this host actually belongs to the 477 * destination group on the loopback interface. 478 */ 479 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 480 m_freem(m); 481 goto done; 482 } 483 484 goto sendit; 485 } else { 486 m->m_flags &= ~M_MCAST; 487 } 488 489 /* 490 * If the source address is not specified yet, use the address 491 * of the outoing interface. In case, keep note we did that, so 492 * if the the firewall changes the next-hop causing the output 493 * interface to change, we can fix that. 494 */ 495 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) { 496 /* Interface may have no addresses. */ 497 if (ia != NULL) { 498 ip->ip_src = IA_SIN(ia)->sin_addr; 499 src_was_INADDR_ANY = 1; 500 } 501 } 502 503 #ifdef ALTQ 504 /* 505 * Disable packet drop hack. 506 * Packetdrop should be done by queueing. 507 */ 508 #else /* !ALTQ */ 509 /* 510 * Verify that we have any chance at all of being able to queue 511 * the packet or packet fragments 512 */ 513 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 514 ifp->if_snd.ifq_maxlen) { 515 error = ENOBUFS; 516 ipstat.ips_odropped++; 517 goto bad; 518 } 519 #endif /* !ALTQ */ 520 521 /* 522 * Look for broadcast address and 523 * verify user is allowed to send 524 * such a packet. 525 */ 526 if (isbroadcast) { 527 if (!(ifp->if_flags & IFF_BROADCAST)) { 528 error = EADDRNOTAVAIL; 529 goto bad; 530 } 531 if (!(flags & IP_ALLOWBROADCAST)) { 532 error = EACCES; 533 goto bad; 534 } 535 /* don't allow broadcast messages to be fragmented */ 536 if (ip->ip_len > ifp->if_mtu) { 537 error = EMSGSIZE; 538 goto bad; 539 } 540 m->m_flags |= M_BCAST; 541 } else { 542 m->m_flags &= ~M_BCAST; 543 } 544 545 sendit: 546 #ifdef IPSEC 547 /* get SP for this packet */ 548 if (so == NULL) 549 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 550 else 551 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 552 553 if (sp == NULL) { 554 ipsecstat.out_inval++; 555 goto bad; 556 } 557 558 error = 0; 559 560 /* check policy */ 561 switch (sp->policy) { 562 case IPSEC_POLICY_DISCARD: 563 /* 564 * This packet is just discarded. 565 */ 566 ipsecstat.out_polvio++; 567 goto bad; 568 569 case IPSEC_POLICY_BYPASS: 570 case IPSEC_POLICY_NONE: 571 /* no need to do IPsec. */ 572 goto skip_ipsec; 573 574 case IPSEC_POLICY_IPSEC: 575 if (sp->req == NULL) { 576 /* acquire a policy */ 577 error = key_spdacquire(sp); 578 goto bad; 579 } 580 break; 581 582 case IPSEC_POLICY_ENTRUST: 583 default: 584 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 585 } 586 { 587 struct ipsec_output_state state; 588 bzero(&state, sizeof state); 589 state.m = m; 590 if (flags & IP_ROUTETOIF) { 591 state.ro = &iproute; 592 bzero(&iproute, sizeof iproute); 593 } else 594 state.ro = ro; 595 state.dst = (struct sockaddr *)dst; 596 597 ip->ip_sum = 0; 598 599 /* 600 * XXX 601 * delayed checksums are not currently compatible with IPsec 602 */ 603 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 604 in_delayed_cksum(m); 605 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 606 } 607 608 ip->ip_len = htons(ip->ip_len); 609 ip->ip_off = htons(ip->ip_off); 610 611 error = ipsec4_output(&state, sp, flags); 612 613 m = state.m; 614 if (flags & IP_ROUTETOIF) { 615 /* 616 * if we have tunnel mode SA, we may need to ignore 617 * IP_ROUTETOIF. 618 */ 619 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 620 flags &= ~IP_ROUTETOIF; 621 ro = state.ro; 622 } 623 } else 624 ro = state.ro; 625 dst = (struct sockaddr_in *)state.dst; 626 if (error) { 627 /* mbuf is already reclaimed in ipsec4_output. */ 628 m0 = NULL; 629 switch (error) { 630 case EHOSTUNREACH: 631 case ENETUNREACH: 632 case EMSGSIZE: 633 case ENOBUFS: 634 case ENOMEM: 635 break; 636 default: 637 kprintf("ip4_output (ipsec): error code %d\n", error); 638 /*fall through*/ 639 case ENOENT: 640 /* don't show these error codes to the user */ 641 error = 0; 642 break; 643 } 644 goto bad; 645 } 646 } 647 648 /* be sure to update variables that are affected by ipsec4_output() */ 649 ip = mtod(m, struct ip *); 650 #ifdef _IP_VHL 651 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 652 #else 653 hlen = ip->ip_hl << 2; 654 #endif 655 if (ro->ro_rt == NULL) { 656 if (!(flags & IP_ROUTETOIF)) { 657 kprintf("ip_output: " 658 "can't update route after IPsec processing\n"); 659 error = EHOSTUNREACH; /*XXX*/ 660 goto bad; 661 } 662 } else { 663 ia = ifatoia(ro->ro_rt->rt_ifa); 664 ifp = ro->ro_rt->rt_ifp; 665 } 666 667 /* make it flipped, again. */ 668 ip->ip_len = ntohs(ip->ip_len); 669 ip->ip_off = ntohs(ip->ip_off); 670 skip_ipsec: 671 #endif /*IPSEC*/ 672 #ifdef FAST_IPSEC 673 /* 674 * Check the security policy (SP) for the packet and, if 675 * required, do IPsec-related processing. There are two 676 * cases here; the first time a packet is sent through 677 * it will be untagged and handled by ipsec4_checkpolicy. 678 * If the packet is resubmitted to ip_output (e.g. after 679 * AH, ESP, etc. processing), there will be a tag to bypass 680 * the lookup and related policy checking. 681 */ 682 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 683 crit_enter(); 684 if (mtag != NULL) { 685 tdbi = (struct tdb_ident *)m_tag_data(mtag); 686 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 687 if (sp == NULL) 688 error = -EINVAL; /* force silent drop */ 689 m_tag_delete(m, mtag); 690 } else { 691 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 692 &error, inp); 693 } 694 /* 695 * There are four return cases: 696 * sp != NULL apply IPsec policy 697 * sp == NULL, error == 0 no IPsec handling needed 698 * sp == NULL, error == -EINVAL discard packet w/o error 699 * sp == NULL, error != 0 discard packet, report error 700 */ 701 if (sp != NULL) { 702 /* Loop detection, check if ipsec processing already done */ 703 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 704 for (mtag = m_tag_first(m); mtag != NULL; 705 mtag = m_tag_next(m, mtag)) { 706 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 707 continue; 708 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 709 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 710 continue; 711 /* 712 * Check if policy has an SA associated with it. 713 * This can happen when an SP has yet to acquire 714 * an SA; e.g. on first reference. If it occurs, 715 * then we let ipsec4_process_packet do its thing. 716 */ 717 if (sp->req->sav == NULL) 718 break; 719 tdbi = (struct tdb_ident *)m_tag_data(mtag); 720 if (tdbi->spi == sp->req->sav->spi && 721 tdbi->proto == sp->req->sav->sah->saidx.proto && 722 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 723 sizeof(union sockaddr_union)) == 0) { 724 /* 725 * No IPsec processing is needed, free 726 * reference to SP. 727 * 728 * NB: null pointer to avoid free at 729 * done: below. 730 */ 731 KEY_FREESP(&sp), sp = NULL; 732 crit_exit(); 733 goto spd_done; 734 } 735 } 736 737 /* 738 * Do delayed checksums now because we send before 739 * this is done in the normal processing path. 740 */ 741 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 742 in_delayed_cksum(m); 743 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 744 } 745 746 ip->ip_len = htons(ip->ip_len); 747 ip->ip_off = htons(ip->ip_off); 748 749 /* NB: callee frees mbuf */ 750 error = ipsec4_process_packet(m, sp->req, flags, 0); 751 /* 752 * Preserve KAME behaviour: ENOENT can be returned 753 * when an SA acquire is in progress. Don't propagate 754 * this to user-level; it confuses applications. 755 * 756 * XXX this will go away when the SADB is redone. 757 */ 758 if (error == ENOENT) 759 error = 0; 760 crit_exit(); 761 goto done; 762 } else { 763 crit_exit(); 764 765 if (error != 0) { 766 /* 767 * Hack: -EINVAL is used to signal that a packet 768 * should be silently discarded. This is typically 769 * because we asked key management for an SA and 770 * it was delayed (e.g. kicked up to IKE). 771 */ 772 if (error == -EINVAL) 773 error = 0; 774 goto bad; 775 } else { 776 /* No IPsec processing for this packet. */ 777 } 778 #ifdef notyet 779 /* 780 * If deferred crypto processing is needed, check that 781 * the interface supports it. 782 */ 783 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 784 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 785 /* notify IPsec to do its own crypto */ 786 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 787 error = EHOSTUNREACH; 788 goto bad; 789 } 790 #endif 791 } 792 spd_done: 793 #endif /* FAST_IPSEC */ 794 795 /* We are already being fwd'd from a firewall. */ 796 if (next_hop != NULL) 797 goto pass; 798 799 /* No pfil hooks */ 800 if (!pfil_has_hooks(&inet_pfil_hook)) { 801 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 802 /* 803 * Strip dummynet tags from stranded packets 804 */ 805 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 806 KKASSERT(mtag != NULL); 807 m_tag_delete(m, mtag); 808 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 809 } 810 goto pass; 811 } 812 813 /* 814 * IpHack's section. 815 * - Xlate: translate packet's addr/port (NAT). 816 * - Firewall: deny/allow/etc. 817 * - Wrap: fake packet's addr/port <unimpl.> 818 * - Encapsulate: put it in another IP and send out. <unimp.> 819 */ 820 821 /* 822 * Run through list of hooks for output packets. 823 */ 824 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 825 if (error != 0 || m == NULL) 826 goto done; 827 ip = mtod(m, struct ip *); 828 829 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 830 /* 831 * Check dst to make sure it is directly reachable on the 832 * interface we previously thought it was. 833 * If it isn't (which may be likely in some situations) we have 834 * to re-route it (ie, find a route for the next-hop and the 835 * associated interface) and set them here. This is nested 836 * forwarding which in most cases is undesirable, except where 837 * such control is nigh impossible. So we do it here. 838 * And I'm babbling. 839 */ 840 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 841 KKASSERT(mtag != NULL); 842 next_hop = m_tag_data(mtag); 843 844 /* 845 * Try local forwarding first 846 */ 847 if (ip_localforward(m, next_hop, hlen)) 848 goto done; 849 850 /* 851 * Relocate the route based on next_hop. 852 * If the current route is inp's cache, keep it untouched. 853 */ 854 if (ro == &iproute && ro->ro_rt != NULL) { 855 RTFREE(ro->ro_rt); 856 ro->ro_rt = NULL; 857 } 858 ro = &iproute; 859 bzero(ro, sizeof *ro); 860 861 /* 862 * Forwarding to broadcast address is not allowed. 863 * XXX Should we follow IP_ROUTETOIF? 864 */ 865 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF); 866 867 /* We are doing forwarding now */ 868 flags |= IP_FORWARDING; 869 870 goto reroute; 871 } 872 873 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 874 struct dn_pkt *dn_pkt; 875 876 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 877 KKASSERT(mtag != NULL); 878 dn_pkt = m_tag_data(mtag); 879 880 /* 881 * Under certain cases it is not possible to recalculate 882 * 'ro' and 'dst', let alone 'flags', so just save them in 883 * dummynet tag and avoid the possible wrong reculcalation 884 * when we come back to ip_output() again. 885 * 886 * All other parameters have been already used and so they 887 * are not needed anymore. 888 * XXX if the ifp is deleted while a pkt is in dummynet, 889 * we are in trouble! (TODO use ifnet_detach_event) 890 * 891 * We need to copy *ro because for ICMP pkts (and maybe 892 * others) the caller passed a pointer into the stack; 893 * dst might also be a pointer into *ro so it needs to 894 * be updated. 895 */ 896 dn_pkt->ro = *ro; 897 if (ro->ro_rt) 898 ro->ro_rt->rt_refcnt++; 899 if (dst == (struct sockaddr_in *)&ro->ro_dst) { 900 /* 'dst' points into 'ro' */ 901 dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst); 902 } 903 dn_pkt->dn_dst = dst; 904 dn_pkt->flags = flags; 905 906 ip_dn_queue(m); 907 goto done; 908 } 909 pass: 910 /* 127/8 must not appear on wire - RFC1122. */ 911 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 912 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 913 if (!(ifp->if_flags & IFF_LOOPBACK)) { 914 ipstat.ips_badaddr++; 915 error = EADDRNOTAVAIL; 916 goto bad; 917 } 918 } 919 920 m->m_pkthdr.csum_flags |= CSUM_IP; 921 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 922 if (sw_csum & CSUM_DELAY_DATA) { 923 in_delayed_cksum(m); 924 sw_csum &= ~CSUM_DELAY_DATA; 925 } 926 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 927 928 /* 929 * If small enough for interface, or the interface will take 930 * care of the fragmentation for us, can just send directly. 931 */ 932 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 933 !(ip->ip_off & IP_DF))) { 934 ip->ip_len = htons(ip->ip_len); 935 ip->ip_off = htons(ip->ip_off); 936 ip->ip_sum = 0; 937 if (sw_csum & CSUM_DELAY_IP) { 938 if (ip->ip_vhl == IP_VHL_BORING) 939 ip->ip_sum = in_cksum_hdr(ip); 940 else 941 ip->ip_sum = in_cksum(m, hlen); 942 } 943 944 /* Record statistics for this interface address. */ 945 if (!(flags & IP_FORWARDING) && ia) { 946 ia->ia_ifa.if_opackets++; 947 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 948 } 949 950 #ifdef IPSEC 951 /* clean ipsec history once it goes out of the node */ 952 ipsec_delaux(m); 953 #endif 954 955 #ifdef MBUF_STRESS_TEST 956 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 957 struct mbuf *m1, *m2; 958 int length, tmp; 959 960 tmp = length = m->m_pkthdr.len; 961 962 while ((length -= mbuf_frag_size) >= 1) { 963 m1 = m_split(m, length, MB_DONTWAIT); 964 if (m1 == NULL) 965 break; 966 m2 = m; 967 while (m2->m_next != NULL) 968 m2 = m2->m_next; 969 m2->m_next = m1; 970 } 971 m->m_pkthdr.len = tmp; 972 } 973 #endif 974 975 #ifdef MPLS 976 if (!mpls_output_process(m, ro->ro_rt)) 977 goto done; 978 #endif 979 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 980 ro->ro_rt); 981 goto done; 982 } 983 984 if (ip->ip_off & IP_DF) { 985 error = EMSGSIZE; 986 /* 987 * This case can happen if the user changed the MTU 988 * of an interface after enabling IP on it. Because 989 * most netifs don't keep track of routes pointing to 990 * them, there is no way for one to update all its 991 * routes when the MTU is changed. 992 */ 993 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 994 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 995 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 996 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 997 } 998 ipstat.ips_cantfrag++; 999 goto bad; 1000 } 1001 1002 /* 1003 * Too large for interface; fragment if possible. If successful, 1004 * on return, m will point to a list of packets to be sent. 1005 */ 1006 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1007 if (error) 1008 goto bad; 1009 for (; m; m = m0) { 1010 m0 = m->m_nextpkt; 1011 m->m_nextpkt = NULL; 1012 #ifdef IPSEC 1013 /* clean ipsec history once it goes out of the node */ 1014 ipsec_delaux(m); 1015 #endif 1016 if (error == 0) { 1017 /* Record statistics for this interface address. */ 1018 if (ia != NULL) { 1019 ia->ia_ifa.if_opackets++; 1020 ia->ia_ifa.if_obytes += 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 = (struct ifnet *)NULL; 1190 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1191 mhip->ip_off = htons(mhip->ip_off); 1192 mhip->ip_sum = 0; 1193 if (sw_csum & CSUM_DELAY_IP) 1194 mhip->ip_sum = in_cksum(m, mhlen); 1195 *mnext = m; 1196 mnext = &m->m_nextpkt; 1197 } 1198 ipstat.ips_ofragments += nfrags; 1199 1200 /* set first marker for fragment chain */ 1201 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1202 m0->m_pkthdr.csum_data = nfrags; 1203 1204 /* 1205 * Update first fragment by trimming what's been copied out 1206 * and updating header. 1207 */ 1208 m_adj(m0, hlen + firstlen - ip->ip_len); 1209 m0->m_pkthdr.len = hlen + firstlen; 1210 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1211 ip->ip_off |= IP_MF; 1212 ip->ip_off = htons(ip->ip_off); 1213 ip->ip_sum = 0; 1214 if (sw_csum & CSUM_DELAY_IP) 1215 ip->ip_sum = in_cksum(m0, hlen); 1216 1217 done: 1218 *m_frag = m0; 1219 return error; 1220 } 1221 1222 void 1223 in_delayed_cksum(struct mbuf *m) 1224 { 1225 struct ip *ip; 1226 u_short csum, offset; 1227 1228 ip = mtod(m, struct ip *); 1229 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1230 csum = in_cksum_skip(m, ip->ip_len, offset); 1231 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1232 csum = 0xffff; 1233 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1234 1235 if (offset + sizeof(u_short) > m->m_len) { 1236 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1237 m->m_len, offset, ip->ip_p); 1238 /* 1239 * XXX 1240 * this shouldn't happen, but if it does, the 1241 * correct behavior may be to insert the checksum 1242 * in the existing chain instead of rearranging it. 1243 */ 1244 m = m_pullup(m, offset + sizeof(u_short)); 1245 } 1246 *(u_short *)(m->m_data + offset) = csum; 1247 } 1248 1249 /* 1250 * Insert IP options into preformed packet. 1251 * Adjust IP destination as required for IP source routing, 1252 * as indicated by a non-zero in_addr at the start of the options. 1253 * 1254 * XXX This routine assumes that the packet has no options in place. 1255 */ 1256 static struct mbuf * 1257 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1258 { 1259 struct ipoption *p = mtod(opt, struct ipoption *); 1260 struct mbuf *n; 1261 struct ip *ip = mtod(m, struct ip *); 1262 unsigned optlen; 1263 1264 optlen = opt->m_len - sizeof p->ipopt_dst; 1265 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1266 *phlen = 0; 1267 return (m); /* XXX should fail */ 1268 } 1269 if (p->ipopt_dst.s_addr) 1270 ip->ip_dst = p->ipopt_dst; 1271 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1272 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1273 if (n == NULL) { 1274 *phlen = 0; 1275 return (m); 1276 } 1277 n->m_pkthdr.rcvif = (struct ifnet *)NULL; 1278 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1279 m->m_len -= sizeof(struct ip); 1280 m->m_data += sizeof(struct ip); 1281 n->m_next = m; 1282 m = n; 1283 m->m_len = optlen + sizeof(struct ip); 1284 m->m_data += max_linkhdr; 1285 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1286 } else { 1287 m->m_data -= optlen; 1288 m->m_len += optlen; 1289 m->m_pkthdr.len += optlen; 1290 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1291 } 1292 ip = mtod(m, struct ip *); 1293 bcopy(p->ipopt_list, ip + 1, optlen); 1294 *phlen = sizeof(struct ip) + optlen; 1295 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1296 ip->ip_len += optlen; 1297 return (m); 1298 } 1299 1300 /* 1301 * Copy options from ip to jp, 1302 * omitting those not copied during fragmentation. 1303 */ 1304 int 1305 ip_optcopy(struct ip *ip, struct ip *jp) 1306 { 1307 u_char *cp, *dp; 1308 int opt, optlen, cnt; 1309 1310 cp = (u_char *)(ip + 1); 1311 dp = (u_char *)(jp + 1); 1312 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1313 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1314 opt = cp[0]; 1315 if (opt == IPOPT_EOL) 1316 break; 1317 if (opt == IPOPT_NOP) { 1318 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1319 *dp++ = IPOPT_NOP; 1320 optlen = 1; 1321 continue; 1322 } 1323 1324 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1325 ("ip_optcopy: malformed ipv4 option")); 1326 optlen = cp[IPOPT_OLEN]; 1327 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1328 ("ip_optcopy: malformed ipv4 option")); 1329 1330 /* bogus lengths should have been caught by ip_dooptions */ 1331 if (optlen > cnt) 1332 optlen = cnt; 1333 if (IPOPT_COPIED(opt)) { 1334 bcopy(cp, dp, optlen); 1335 dp += optlen; 1336 } 1337 } 1338 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1339 *dp++ = IPOPT_EOL; 1340 return (optlen); 1341 } 1342 1343 /* 1344 * IP socket option processing. 1345 */ 1346 int 1347 ip_ctloutput(struct socket *so, struct sockopt *sopt) 1348 { 1349 struct inpcb *inp = so->so_pcb; 1350 int error, optval; 1351 1352 error = optval = 0; 1353 if (sopt->sopt_level != IPPROTO_IP) { 1354 return (EINVAL); 1355 } 1356 1357 switch (sopt->sopt_dir) { 1358 case SOPT_SET: 1359 switch (sopt->sopt_name) { 1360 case IP_OPTIONS: 1361 #ifdef notyet 1362 case IP_RETOPTS: 1363 #endif 1364 { 1365 struct mbuf *m; 1366 if (sopt->sopt_valsize > MLEN) { 1367 error = EMSGSIZE; 1368 break; 1369 } 1370 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1371 if (m == NULL) { 1372 error = ENOBUFS; 1373 break; 1374 } 1375 m->m_len = sopt->sopt_valsize; 1376 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len, 1377 m->m_len); 1378 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 1379 m)); 1380 } 1381 1382 case IP_TOS: 1383 case IP_TTL: 1384 case IP_MINTTL: 1385 case IP_RECVOPTS: 1386 case IP_RECVRETOPTS: 1387 case IP_RECVDSTADDR: 1388 case IP_RECVIF: 1389 case IP_RECVTTL: 1390 case IP_FAITH: 1391 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1392 sizeof optval); 1393 if (error) 1394 break; 1395 switch (sopt->sopt_name) { 1396 case IP_TOS: 1397 inp->inp_ip_tos = optval; 1398 break; 1399 1400 case IP_TTL: 1401 inp->inp_ip_ttl = optval; 1402 break; 1403 case IP_MINTTL: 1404 if (optval >= 0 && optval <= MAXTTL) 1405 inp->inp_ip_minttl = optval; 1406 else 1407 error = EINVAL; 1408 break; 1409 #define OPTSET(bit) \ 1410 if (optval) \ 1411 inp->inp_flags |= bit; \ 1412 else \ 1413 inp->inp_flags &= ~bit; 1414 1415 case IP_RECVOPTS: 1416 OPTSET(INP_RECVOPTS); 1417 break; 1418 1419 case IP_RECVRETOPTS: 1420 OPTSET(INP_RECVRETOPTS); 1421 break; 1422 1423 case IP_RECVDSTADDR: 1424 OPTSET(INP_RECVDSTADDR); 1425 break; 1426 1427 case IP_RECVIF: 1428 OPTSET(INP_RECVIF); 1429 break; 1430 1431 case IP_RECVTTL: 1432 OPTSET(INP_RECVTTL); 1433 break; 1434 1435 case IP_FAITH: 1436 OPTSET(INP_FAITH); 1437 break; 1438 } 1439 break; 1440 #undef OPTSET 1441 1442 case IP_MULTICAST_IF: 1443 case IP_MULTICAST_VIF: 1444 case IP_MULTICAST_TTL: 1445 case IP_MULTICAST_LOOP: 1446 case IP_ADD_MEMBERSHIP: 1447 case IP_DROP_MEMBERSHIP: 1448 error = ip_setmoptions(sopt, &inp->inp_moptions); 1449 break; 1450 1451 case IP_PORTRANGE: 1452 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1453 sizeof optval); 1454 if (error) 1455 break; 1456 1457 switch (optval) { 1458 case IP_PORTRANGE_DEFAULT: 1459 inp->inp_flags &= ~(INP_LOWPORT); 1460 inp->inp_flags &= ~(INP_HIGHPORT); 1461 break; 1462 1463 case IP_PORTRANGE_HIGH: 1464 inp->inp_flags &= ~(INP_LOWPORT); 1465 inp->inp_flags |= INP_HIGHPORT; 1466 break; 1467 1468 case IP_PORTRANGE_LOW: 1469 inp->inp_flags &= ~(INP_HIGHPORT); 1470 inp->inp_flags |= INP_LOWPORT; 1471 break; 1472 1473 default: 1474 error = EINVAL; 1475 break; 1476 } 1477 break; 1478 1479 #if defined(IPSEC) || defined(FAST_IPSEC) 1480 case IP_IPSEC_POLICY: 1481 { 1482 caddr_t req; 1483 size_t len = 0; 1484 int priv; 1485 struct mbuf *m; 1486 int optname; 1487 1488 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1489 break; 1490 soopt_to_mbuf(sopt, m); 1491 priv = (sopt->sopt_td != NULL && 1492 priv_check(sopt->sopt_td, PRIV_ROOT) != 0) ? 0 : 1; 1493 req = mtod(m, caddr_t); 1494 len = m->m_len; 1495 optname = sopt->sopt_name; 1496 error = ipsec4_set_policy(inp, optname, req, len, priv); 1497 m_freem(m); 1498 break; 1499 } 1500 #endif /*IPSEC*/ 1501 1502 default: 1503 error = ENOPROTOOPT; 1504 break; 1505 } 1506 break; 1507 1508 case SOPT_GET: 1509 switch (sopt->sopt_name) { 1510 case IP_OPTIONS: 1511 case IP_RETOPTS: 1512 if (inp->inp_options) 1513 soopt_from_kbuf(sopt, mtod(inp->inp_options, 1514 char *), 1515 inp->inp_options->m_len); 1516 else 1517 sopt->sopt_valsize = 0; 1518 break; 1519 1520 case IP_TOS: 1521 case IP_TTL: 1522 case IP_MINTTL: 1523 case IP_RECVOPTS: 1524 case IP_RECVRETOPTS: 1525 case IP_RECVDSTADDR: 1526 case IP_RECVTTL: 1527 case IP_RECVIF: 1528 case IP_PORTRANGE: 1529 case IP_FAITH: 1530 switch (sopt->sopt_name) { 1531 1532 case IP_TOS: 1533 optval = inp->inp_ip_tos; 1534 break; 1535 1536 case IP_TTL: 1537 optval = inp->inp_ip_ttl; 1538 break; 1539 case IP_MINTTL: 1540 optval = inp->inp_ip_minttl; 1541 break; 1542 1543 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1544 1545 case IP_RECVOPTS: 1546 optval = OPTBIT(INP_RECVOPTS); 1547 break; 1548 1549 case IP_RECVRETOPTS: 1550 optval = OPTBIT(INP_RECVRETOPTS); 1551 break; 1552 1553 case IP_RECVDSTADDR: 1554 optval = OPTBIT(INP_RECVDSTADDR); 1555 break; 1556 1557 case IP_RECVTTL: 1558 optval = OPTBIT(INP_RECVTTL); 1559 break; 1560 1561 case IP_RECVIF: 1562 optval = OPTBIT(INP_RECVIF); 1563 break; 1564 1565 case IP_PORTRANGE: 1566 if (inp->inp_flags & INP_HIGHPORT) 1567 optval = IP_PORTRANGE_HIGH; 1568 else if (inp->inp_flags & INP_LOWPORT) 1569 optval = IP_PORTRANGE_LOW; 1570 else 1571 optval = 0; 1572 break; 1573 1574 case IP_FAITH: 1575 optval = OPTBIT(INP_FAITH); 1576 break; 1577 } 1578 soopt_from_kbuf(sopt, &optval, sizeof optval); 1579 break; 1580 1581 case IP_MULTICAST_IF: 1582 case IP_MULTICAST_VIF: 1583 case IP_MULTICAST_TTL: 1584 case IP_MULTICAST_LOOP: 1585 case IP_ADD_MEMBERSHIP: 1586 case IP_DROP_MEMBERSHIP: 1587 error = ip_getmoptions(sopt, inp->inp_moptions); 1588 break; 1589 1590 #if defined(IPSEC) || defined(FAST_IPSEC) 1591 case IP_IPSEC_POLICY: 1592 { 1593 struct mbuf *m = NULL; 1594 caddr_t req = NULL; 1595 size_t len = 0; 1596 1597 if (m != NULL) { 1598 req = mtod(m, caddr_t); 1599 len = m->m_len; 1600 } 1601 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1602 if (error == 0) 1603 error = soopt_from_mbuf(sopt, m); /* XXX */ 1604 if (error == 0) 1605 m_freem(m); 1606 break; 1607 } 1608 #endif /*IPSEC*/ 1609 1610 default: 1611 error = ENOPROTOOPT; 1612 break; 1613 } 1614 break; 1615 } 1616 return (error); 1617 } 1618 1619 /* 1620 * Set up IP options in pcb for insertion in output packets. 1621 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1622 * with destination address if source routed. 1623 */ 1624 static int 1625 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1626 { 1627 int cnt, optlen; 1628 u_char *cp; 1629 u_char opt; 1630 1631 /* turn off any old options */ 1632 if (*pcbopt) 1633 m_free(*pcbopt); 1634 *pcbopt = 0; 1635 if (m == NULL || m->m_len == 0) { 1636 /* 1637 * Only turning off any previous options. 1638 */ 1639 if (m != NULL) 1640 m_free(m); 1641 return (0); 1642 } 1643 1644 if (m->m_len % sizeof(int32_t)) 1645 goto bad; 1646 /* 1647 * IP first-hop destination address will be stored before 1648 * actual options; move other options back 1649 * and clear it when none present. 1650 */ 1651 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1652 goto bad; 1653 cnt = m->m_len; 1654 m->m_len += sizeof(struct in_addr); 1655 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1656 ovbcopy(mtod(m, caddr_t), cp, cnt); 1657 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1658 1659 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1660 opt = cp[IPOPT_OPTVAL]; 1661 if (opt == IPOPT_EOL) 1662 break; 1663 if (opt == IPOPT_NOP) 1664 optlen = 1; 1665 else { 1666 if (cnt < IPOPT_OLEN + sizeof *cp) 1667 goto bad; 1668 optlen = cp[IPOPT_OLEN]; 1669 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1670 goto bad; 1671 } 1672 switch (opt) { 1673 1674 default: 1675 break; 1676 1677 case IPOPT_LSRR: 1678 case IPOPT_SSRR: 1679 /* 1680 * user process specifies route as: 1681 * ->A->B->C->D 1682 * D must be our final destination (but we can't 1683 * check that since we may not have connected yet). 1684 * A is first hop destination, which doesn't appear in 1685 * actual IP option, but is stored before the options. 1686 */ 1687 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1688 goto bad; 1689 m->m_len -= sizeof(struct in_addr); 1690 cnt -= sizeof(struct in_addr); 1691 optlen -= sizeof(struct in_addr); 1692 cp[IPOPT_OLEN] = optlen; 1693 /* 1694 * Move first hop before start of options. 1695 */ 1696 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1697 sizeof(struct in_addr)); 1698 /* 1699 * Then copy rest of options back 1700 * to close up the deleted entry. 1701 */ 1702 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1703 &cp[IPOPT_OFFSET+1], 1704 cnt - (IPOPT_MINOFF - 1)); 1705 break; 1706 } 1707 } 1708 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1709 goto bad; 1710 *pcbopt = m; 1711 return (0); 1712 1713 bad: 1714 m_free(m); 1715 return (EINVAL); 1716 } 1717 1718 /* 1719 * XXX 1720 * The whole multicast option thing needs to be re-thought. 1721 * Several of these options are equally applicable to non-multicast 1722 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1723 * standard option (IP_TTL). 1724 */ 1725 1726 /* 1727 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1728 */ 1729 static struct ifnet * 1730 ip_multicast_if(struct in_addr *a, int *ifindexp) 1731 { 1732 int ifindex; 1733 struct ifnet *ifp; 1734 1735 if (ifindexp) 1736 *ifindexp = 0; 1737 if (ntohl(a->s_addr) >> 24 == 0) { 1738 ifindex = ntohl(a->s_addr) & 0xffffff; 1739 if (ifindex < 0 || if_index < ifindex) 1740 return NULL; 1741 ifp = ifindex2ifnet[ifindex]; 1742 if (ifindexp) 1743 *ifindexp = ifindex; 1744 } else { 1745 ifp = INADDR_TO_IFP(a); 1746 } 1747 return ifp; 1748 } 1749 1750 /* 1751 * Set the IP multicast options in response to user setsockopt(). 1752 */ 1753 static int 1754 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1755 { 1756 int error = 0; 1757 int i; 1758 struct in_addr addr; 1759 struct ip_mreq mreq; 1760 struct ifnet *ifp; 1761 struct ip_moptions *imo = *imop; 1762 int ifindex; 1763 1764 if (imo == NULL) { 1765 /* 1766 * No multicast option buffer attached to the pcb; 1767 * allocate one and initialize to default values. 1768 */ 1769 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1770 1771 *imop = imo; 1772 imo->imo_multicast_ifp = NULL; 1773 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1774 imo->imo_multicast_vif = -1; 1775 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1776 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1777 imo->imo_num_memberships = 0; 1778 } 1779 switch (sopt->sopt_name) { 1780 /* store an index number for the vif you wanna use in the send */ 1781 case IP_MULTICAST_VIF: 1782 if (legal_vif_num == 0) { 1783 error = EOPNOTSUPP; 1784 break; 1785 } 1786 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i); 1787 if (error) 1788 break; 1789 if (!legal_vif_num(i) && (i != -1)) { 1790 error = EINVAL; 1791 break; 1792 } 1793 imo->imo_multicast_vif = i; 1794 break; 1795 1796 case IP_MULTICAST_IF: 1797 /* 1798 * Select the interface for outgoing multicast packets. 1799 */ 1800 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr); 1801 if (error) 1802 break; 1803 1804 /* 1805 * INADDR_ANY is used to remove a previous selection. 1806 * When no interface is selected, a default one is 1807 * chosen every time a multicast packet is sent. 1808 */ 1809 if (addr.s_addr == INADDR_ANY) { 1810 imo->imo_multicast_ifp = NULL; 1811 break; 1812 } 1813 /* 1814 * The selected interface is identified by its local 1815 * IP address. Find the interface and confirm that 1816 * it supports multicasting. 1817 */ 1818 crit_enter(); 1819 ifp = ip_multicast_if(&addr, &ifindex); 1820 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1821 crit_exit(); 1822 error = EADDRNOTAVAIL; 1823 break; 1824 } 1825 imo->imo_multicast_ifp = ifp; 1826 if (ifindex) 1827 imo->imo_multicast_addr = addr; 1828 else 1829 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1830 crit_exit(); 1831 break; 1832 1833 case IP_MULTICAST_TTL: 1834 /* 1835 * Set the IP time-to-live for outgoing multicast packets. 1836 * The original multicast API required a char argument, 1837 * which is inconsistent with the rest of the socket API. 1838 * We allow either a char or an int. 1839 */ 1840 if (sopt->sopt_valsize == 1) { 1841 u_char ttl; 1842 error = soopt_to_kbuf(sopt, &ttl, 1, 1); 1843 if (error) 1844 break; 1845 imo->imo_multicast_ttl = ttl; 1846 } else { 1847 u_int ttl; 1848 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl); 1849 if (error) 1850 break; 1851 if (ttl > 255) 1852 error = EINVAL; 1853 else 1854 imo->imo_multicast_ttl = ttl; 1855 } 1856 break; 1857 1858 case IP_MULTICAST_LOOP: 1859 /* 1860 * Set the loopback flag for outgoing multicast packets. 1861 * Must be zero or one. The original multicast API required a 1862 * char argument, which is inconsistent with the rest 1863 * of the socket API. We allow either a char or an int. 1864 */ 1865 if (sopt->sopt_valsize == 1) { 1866 u_char loop; 1867 1868 error = soopt_to_kbuf(sopt, &loop, 1, 1); 1869 if (error) 1870 break; 1871 imo->imo_multicast_loop = !!loop; 1872 } else { 1873 u_int loop; 1874 1875 error = soopt_to_kbuf(sopt, &loop, sizeof loop, 1876 sizeof loop); 1877 if (error) 1878 break; 1879 imo->imo_multicast_loop = !!loop; 1880 } 1881 break; 1882 1883 case IP_ADD_MEMBERSHIP: 1884 /* 1885 * Add a multicast group membership. 1886 * Group must be a valid IP multicast address. 1887 */ 1888 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1889 if (error) 1890 break; 1891 1892 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1893 error = EINVAL; 1894 break; 1895 } 1896 crit_enter(); 1897 /* 1898 * If no interface address was provided, use the interface of 1899 * the route to the given multicast address. 1900 */ 1901 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1902 struct sockaddr_in dst; 1903 struct rtentry *rt; 1904 1905 bzero(&dst, sizeof(struct sockaddr_in)); 1906 dst.sin_len = sizeof(struct sockaddr_in); 1907 dst.sin_family = AF_INET; 1908 dst.sin_addr = mreq.imr_multiaddr; 1909 rt = rtlookup((struct sockaddr *)&dst); 1910 if (rt == NULL) { 1911 error = EADDRNOTAVAIL; 1912 crit_exit(); 1913 break; 1914 } 1915 --rt->rt_refcnt; 1916 ifp = rt->rt_ifp; 1917 } else { 1918 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1919 } 1920 1921 /* 1922 * See if we found an interface, and confirm that it 1923 * supports multicast. 1924 */ 1925 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1926 error = EADDRNOTAVAIL; 1927 crit_exit(); 1928 break; 1929 } 1930 /* 1931 * See if the membership already exists or if all the 1932 * membership slots are full. 1933 */ 1934 for (i = 0; i < imo->imo_num_memberships; ++i) { 1935 if (imo->imo_membership[i]->inm_ifp == ifp && 1936 imo->imo_membership[i]->inm_addr.s_addr 1937 == mreq.imr_multiaddr.s_addr) 1938 break; 1939 } 1940 if (i < imo->imo_num_memberships) { 1941 error = EADDRINUSE; 1942 crit_exit(); 1943 break; 1944 } 1945 if (i == IP_MAX_MEMBERSHIPS) { 1946 error = ETOOMANYREFS; 1947 crit_exit(); 1948 break; 1949 } 1950 /* 1951 * Everything looks good; add a new record to the multicast 1952 * address list for the given interface. 1953 */ 1954 if ((imo->imo_membership[i] = 1955 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1956 error = ENOBUFS; 1957 crit_exit(); 1958 break; 1959 } 1960 ++imo->imo_num_memberships; 1961 crit_exit(); 1962 break; 1963 1964 case IP_DROP_MEMBERSHIP: 1965 /* 1966 * Drop a multicast group membership. 1967 * Group must be a valid IP multicast address. 1968 */ 1969 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1970 if (error) 1971 break; 1972 1973 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1974 error = EINVAL; 1975 break; 1976 } 1977 1978 crit_enter(); 1979 /* 1980 * If an interface address was specified, get a pointer 1981 * to its ifnet structure. 1982 */ 1983 if (mreq.imr_interface.s_addr == INADDR_ANY) 1984 ifp = NULL; 1985 else { 1986 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1987 if (ifp == NULL) { 1988 error = EADDRNOTAVAIL; 1989 crit_exit(); 1990 break; 1991 } 1992 } 1993 /* 1994 * Find the membership in the membership array. 1995 */ 1996 for (i = 0; i < imo->imo_num_memberships; ++i) { 1997 if ((ifp == NULL || 1998 imo->imo_membership[i]->inm_ifp == ifp) && 1999 imo->imo_membership[i]->inm_addr.s_addr == 2000 mreq.imr_multiaddr.s_addr) 2001 break; 2002 } 2003 if (i == imo->imo_num_memberships) { 2004 error = EADDRNOTAVAIL; 2005 crit_exit(); 2006 break; 2007 } 2008 /* 2009 * Give up the multicast address record to which the 2010 * membership points. 2011 */ 2012 in_delmulti(imo->imo_membership[i]); 2013 /* 2014 * Remove the gap in the membership array. 2015 */ 2016 for (++i; i < imo->imo_num_memberships; ++i) 2017 imo->imo_membership[i-1] = imo->imo_membership[i]; 2018 --imo->imo_num_memberships; 2019 crit_exit(); 2020 break; 2021 2022 default: 2023 error = EOPNOTSUPP; 2024 break; 2025 } 2026 2027 /* 2028 * If all options have default values, no need to keep the mbuf. 2029 */ 2030 if (imo->imo_multicast_ifp == NULL && 2031 imo->imo_multicast_vif == -1 && 2032 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2033 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2034 imo->imo_num_memberships == 0) { 2035 kfree(*imop, M_IPMOPTS); 2036 *imop = NULL; 2037 } 2038 2039 return (error); 2040 } 2041 2042 /* 2043 * Return the IP multicast options in response to user getsockopt(). 2044 */ 2045 static int 2046 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2047 { 2048 struct in_addr addr; 2049 struct in_ifaddr *ia; 2050 int error, optval; 2051 u_char coptval; 2052 2053 error = 0; 2054 switch (sopt->sopt_name) { 2055 case IP_MULTICAST_VIF: 2056 if (imo != NULL) 2057 optval = imo->imo_multicast_vif; 2058 else 2059 optval = -1; 2060 soopt_from_kbuf(sopt, &optval, sizeof optval); 2061 break; 2062 2063 case IP_MULTICAST_IF: 2064 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2065 addr.s_addr = INADDR_ANY; 2066 else if (imo->imo_multicast_addr.s_addr) { 2067 /* return the value user has set */ 2068 addr = imo->imo_multicast_addr; 2069 } else { 2070 ia = IFP_TO_IA(imo->imo_multicast_ifp); 2071 addr.s_addr = (ia == NULL) ? INADDR_ANY 2072 : IA_SIN(ia)->sin_addr.s_addr; 2073 } 2074 soopt_from_kbuf(sopt, &addr, sizeof addr); 2075 break; 2076 2077 case IP_MULTICAST_TTL: 2078 if (imo == NULL) 2079 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2080 else 2081 optval = coptval = imo->imo_multicast_ttl; 2082 if (sopt->sopt_valsize == 1) 2083 soopt_from_kbuf(sopt, &coptval, 1); 2084 else 2085 soopt_from_kbuf(sopt, &optval, sizeof optval); 2086 break; 2087 2088 case IP_MULTICAST_LOOP: 2089 if (imo == NULL) 2090 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2091 else 2092 optval = coptval = imo->imo_multicast_loop; 2093 if (sopt->sopt_valsize == 1) 2094 soopt_from_kbuf(sopt, &coptval, 1); 2095 else 2096 soopt_from_kbuf(sopt, &optval, sizeof optval); 2097 break; 2098 2099 default: 2100 error = ENOPROTOOPT; 2101 break; 2102 } 2103 return (error); 2104 } 2105 2106 /* 2107 * Discard the IP multicast options. 2108 */ 2109 void 2110 ip_freemoptions(struct ip_moptions *imo) 2111 { 2112 int i; 2113 2114 if (imo != NULL) { 2115 for (i = 0; i < imo->imo_num_memberships; ++i) 2116 in_delmulti(imo->imo_membership[i]); 2117 kfree(imo, M_IPMOPTS); 2118 } 2119 } 2120 2121 /* 2122 * Routine called from ip_output() to loop back a copy of an IP multicast 2123 * packet to the input queue of a specified interface. Note that this 2124 * calls the output routine of the loopback "driver", but with an interface 2125 * pointer that might NOT be a loopback interface -- evil, but easier than 2126 * replicating that code here. 2127 */ 2128 static void 2129 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2130 int hlen) 2131 { 2132 struct ip *ip; 2133 struct mbuf *copym; 2134 2135 copym = m_copypacket(m, MB_DONTWAIT); 2136 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2137 copym = m_pullup(copym, hlen); 2138 if (copym != NULL) { 2139 /* 2140 * if the checksum hasn't been computed, mark it as valid 2141 */ 2142 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2143 in_delayed_cksum(copym); 2144 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2145 copym->m_pkthdr.csum_flags |= 2146 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2147 copym->m_pkthdr.csum_data = 0xffff; 2148 } 2149 /* 2150 * We don't bother to fragment if the IP length is greater 2151 * than the interface's MTU. Can this possibly matter? 2152 */ 2153 ip = mtod(copym, struct ip *); 2154 ip->ip_len = htons(ip->ip_len); 2155 ip->ip_off = htons(ip->ip_off); 2156 ip->ip_sum = 0; 2157 if (ip->ip_vhl == IP_VHL_BORING) { 2158 ip->ip_sum = in_cksum_hdr(ip); 2159 } else { 2160 ip->ip_sum = in_cksum(copym, hlen); 2161 } 2162 /* 2163 * NB: 2164 * It's not clear whether there are any lingering 2165 * reentrancy problems in other areas which might 2166 * be exposed by using ip_input directly (in 2167 * particular, everything which modifies the packet 2168 * in-place). Yet another option is using the 2169 * protosw directly to deliver the looped back 2170 * packet. For the moment, we'll err on the side 2171 * of safety by using if_simloop(). 2172 */ 2173 #if 1 /* XXX */ 2174 if (dst->sin_family != AF_INET) { 2175 kprintf("ip_mloopback: bad address family %d\n", 2176 dst->sin_family); 2177 dst->sin_family = AF_INET; 2178 } 2179 #endif 2180 if_simloop(ifp, copym, dst->sin_family, 0); 2181 } 2182 } 2183