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