1 /* 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 30 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $ 31 */ 32 33 #define _IP_VHL 34 35 #include "opt_ipdn.h" 36 #include "opt_ipdivert.h" 37 #include "opt_ipsec.h" 38 #include "opt_mbuf_stress_test.h" 39 #include "opt_mpls.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/protosw.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/proc.h> 50 #include <sys/priv.h> 51 #include <sys/sysctl.h> 52 #include <sys/in_cksum.h> 53 #include <sys/lock.h> 54 55 #include <sys/thread2.h> 56 #include <sys/mplock2.h> 57 #include <sys/msgport2.h> 58 59 #include <net/if.h> 60 #include <net/netisr.h> 61 #include <net/pfil.h> 62 #include <net/route.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_systm.h> 66 #include <netinet/ip.h> 67 #include <netinet/in_pcb.h> 68 #include <netinet/in_var.h> 69 #include <netinet/ip_var.h> 70 71 #include <netproto/mpls/mpls_var.h> 72 73 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 74 75 #ifdef IPSEC 76 #include <netinet6/ipsec.h> 77 #include <netproto/key/key.h> 78 #ifdef IPSEC_DEBUG 79 #include <netproto/key/key_debug.h> 80 #else 81 #define KEYDEBUG(lev,arg) 82 #endif 83 #endif /*IPSEC*/ 84 85 #ifdef FAST_IPSEC 86 #include <netproto/ipsec/ipsec.h> 87 #include <netproto/ipsec/xform.h> 88 #include <netproto/ipsec/key.h> 89 #endif /*FAST_IPSEC*/ 90 91 #include <net/ipfw/ip_fw.h> 92 #include <net/dummynet/ip_dummynet.h> 93 94 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\ 95 x, (ntohl(a.s_addr)>>24)&0xFF,\ 96 (ntohl(a.s_addr)>>16)&0xFF,\ 97 (ntohl(a.s_addr)>>8)&0xFF,\ 98 (ntohl(a.s_addr))&0xFF, y); 99 100 u_short ip_id; 101 102 #ifdef MBUF_STRESS_TEST 103 int mbuf_frag_size = 0; 104 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 105 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 106 #endif 107 108 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 109 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 110 static void ip_mloopback 111 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 112 static int ip_getmoptions 113 (struct sockopt *, struct ip_moptions *); 114 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 115 static int ip_setmoptions 116 (struct sockopt *, struct ip_moptions **); 117 118 int ip_optcopy(struct ip *, struct ip *); 119 120 extern int route_assert_owner_access; 121 122 extern struct protosw inetsw[]; 123 124 static int 125 ip_localforward(struct mbuf *m, const struct sockaddr_in *dst, int hlen) 126 { 127 struct in_ifaddr_container *iac; 128 129 /* 130 * We need to figure out if we have been forwarded to a local 131 * socket. If so, then we should somehow "loop back" to 132 * ip_input(), and get directed to the PCB as if we had received 133 * this packet. This is because it may be difficult to identify 134 * the packets you want to forward until they are being output 135 * and have selected an interface (e.g. locally initiated 136 * packets). If we used the loopback inteface, we would not be 137 * able to control what happens as the packet runs through 138 * ip_input() as it is done through a ISR. 139 */ 140 LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr), ia_hash) { 141 /* 142 * If the addr to forward to is one of ours, we pretend 143 * to be the destination for this packet. 144 */ 145 if (IA_SIN(iac->ia)->sin_addr.s_addr == dst->sin_addr.s_addr) 146 break; 147 } 148 if (iac != NULL) { 149 struct ip *ip; 150 151 if (m->m_pkthdr.rcvif == NULL) 152 m->m_pkthdr.rcvif = ifunit("lo0"); 153 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 154 m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | 155 CSUM_PSEUDO_HDR; 156 m->m_pkthdr.csum_data = 0xffff; 157 } 158 m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; 159 160 /* 161 * Make sure that the IP header is in one mbuf, 162 * required by ip_input 163 */ 164 if (m->m_len < hlen) { 165 m = m_pullup(m, hlen); 166 if (m == NULL) { 167 /* The packet was freed; we are done */ 168 return 1; 169 } 170 } 171 ip = mtod(m, struct ip *); 172 173 ip->ip_len = htons(ip->ip_len); 174 ip->ip_off = htons(ip->ip_off); 175 ip_input(m); 176 177 return 1; /* The packet gets forwarded locally */ 178 } 179 return 0; 180 } 181 182 /* 183 * IP output. The packet in mbuf chain m contains a skeletal IP 184 * header (with len, off, ttl, proto, tos, src, dst). 185 * The mbuf chain containing the packet will be freed. 186 * The mbuf opt, if present, will not be freed. 187 */ 188 int 189 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, 190 int flags, struct ip_moptions *imo, struct inpcb *inp) 191 { 192 struct ip *ip; 193 struct ifnet *ifp = NULL; /* keep compiler happy */ 194 struct mbuf *m; 195 int hlen = sizeof(struct ip); 196 int len, error = 0; 197 struct sockaddr_in *dst = NULL; /* keep compiler happy */ 198 struct in_ifaddr *ia = NULL; 199 int isbroadcast, sw_csum; 200 struct in_addr pkt_dst; 201 struct route iproute; 202 struct m_tag *mtag; 203 #ifdef IPSEC 204 struct secpolicy *sp = NULL; 205 struct socket *so = inp ? inp->inp_socket : NULL; 206 #endif 207 #ifdef FAST_IPSEC 208 struct secpolicy *sp = NULL; 209 struct tdb_ident *tdbi; 210 #endif /* FAST_IPSEC */ 211 struct sockaddr_in *next_hop = NULL; 212 int src_was_INADDR_ANY = 0; /* as the name says... */ 213 214 m = m0; 215 M_ASSERTPKTHDR(m); 216 217 if (ro == NULL) { 218 ro = &iproute; 219 bzero(ro, sizeof *ro); 220 } else if (ro->ro_rt != NULL && ro->ro_rt->rt_cpuid != mycpuid) { 221 if (flags & IP_DEBUGROUTE) { 222 if (route_assert_owner_access) { 223 panic("ip_output: " 224 "rt rt_cpuid %d accessed on cpu %d\n", 225 ro->ro_rt->rt_cpuid, mycpuid); 226 } else { 227 kprintf("ip_output: " 228 "rt rt_cpuid %d accessed on cpu %d\n", 229 ro->ro_rt->rt_cpuid, mycpuid); 230 print_backtrace(-1); 231 } 232 } 233 234 /* 235 * XXX 236 * If the cached rtentry's owner CPU is not the current CPU, 237 * then don't touch the cached rtentry (remote free is too 238 * expensive in this context); just relocate the route. 239 */ 240 ro = &iproute; 241 bzero(ro, sizeof *ro); 242 } 243 244 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 245 /* Next hop */ 246 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 247 KKASSERT(mtag != NULL); 248 next_hop = m_tag_data(mtag); 249 } 250 251 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 252 struct dn_pkt *dn_pkt; 253 254 /* Extract info from dummynet tag */ 255 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 256 KKASSERT(mtag != NULL); 257 dn_pkt = m_tag_data(mtag); 258 259 /* 260 * The packet was already tagged, so part of the 261 * processing was already done, and we need to go down. 262 * Get the calculated parameters from the tag. 263 */ 264 ifp = dn_pkt->ifp; 265 266 KKASSERT(ro == &iproute); 267 *ro = dn_pkt->ro; /* structure copy */ 268 KKASSERT(ro->ro_rt == NULL || ro->ro_rt->rt_cpuid == mycpuid); 269 270 dst = dn_pkt->dn_dst; 271 if (dst == (struct sockaddr_in *)&(dn_pkt->ro.ro_dst)) { 272 /* If 'dst' points into dummynet tag, adjust it */ 273 dst = (struct sockaddr_in *)&(ro->ro_dst); 274 } 275 276 ip = mtod(m, struct ip *); 277 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 278 if (ro->ro_rt) 279 ia = ifatoia(ro->ro_rt->rt_ifa); 280 goto sendit; 281 } 282 283 if (opt) { 284 len = 0; 285 m = ip_insertoptions(m, opt, &len); 286 if (len != 0) 287 hlen = len; 288 } 289 ip = mtod(m, struct ip *); 290 291 /* 292 * Fill in IP header. 293 */ 294 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 295 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 296 ip->ip_off &= IP_DF; 297 ip->ip_id = ip_newid(); 298 ipstat.ips_localout++; 299 } else { 300 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 301 } 302 303 reroute: 304 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 305 306 dst = (struct sockaddr_in *)&ro->ro_dst; 307 /* 308 * If there is a cached route, 309 * check that it is to the same destination 310 * and is still up. If not, free it and try again. 311 * The address family should also be checked in case of sharing the 312 * cache with IPv6. 313 */ 314 if (ro->ro_rt && 315 (!(ro->ro_rt->rt_flags & RTF_UP) || 316 dst->sin_family != AF_INET || 317 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 318 rtfree(ro->ro_rt); 319 ro->ro_rt = NULL; 320 } 321 if (ro->ro_rt == NULL) { 322 bzero(dst, sizeof *dst); 323 dst->sin_family = AF_INET; 324 dst->sin_len = sizeof *dst; 325 dst->sin_addr = pkt_dst; 326 } 327 /* 328 * If routing to interface only, 329 * short circuit routing lookup. 330 */ 331 if (flags & IP_ROUTETOIF) { 332 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 333 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 334 ipstat.ips_noroute++; 335 error = ENETUNREACH; 336 goto bad; 337 } 338 ifp = ia->ia_ifp; 339 ip->ip_ttl = 1; 340 isbroadcast = in_broadcast(dst->sin_addr, ifp); 341 } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) && 342 imo != NULL && imo->imo_multicast_ifp != NULL) { 343 /* 344 * Bypass the normal routing lookup for multicast 345 * packets if the interface is specified. 346 */ 347 ifp = imo->imo_multicast_ifp; 348 ia = IFP_TO_IA(ifp); 349 isbroadcast = 0; /* fool gcc */ 350 } else { 351 /* 352 * If this is the case, we probably don't want to allocate 353 * a protocol-cloned route since we didn't get one from the 354 * ULP. This lets TCP do its thing, while not burdening 355 * forwarding or ICMP with the overhead of cloning a route. 356 * Of course, we still want to do any cloning requested by 357 * the link layer, as this is probably required in all cases 358 * for correct operation (as it is for ARP). 359 */ 360 if (ro->ro_rt == NULL) 361 rtalloc_ign(ro, RTF_PRCLONING); 362 if (ro->ro_rt == NULL) { 363 ipstat.ips_noroute++; 364 error = EHOSTUNREACH; 365 goto bad; 366 } 367 ia = ifatoia(ro->ro_rt->rt_ifa); 368 ifp = ro->ro_rt->rt_ifp; 369 ro->ro_rt->rt_use++; 370 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 371 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 372 if (ro->ro_rt->rt_flags & RTF_HOST) 373 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 374 else 375 isbroadcast = in_broadcast(dst->sin_addr, ifp); 376 } 377 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 378 struct in_multi *inm; 379 380 m->m_flags |= M_MCAST; 381 /* 382 * IP destination address is multicast. Make sure "dst" 383 * still points to the address in "ro". (It may have been 384 * changed to point to a gateway address, above.) 385 */ 386 dst = (struct sockaddr_in *)&ro->ro_dst; 387 /* 388 * See if the caller provided any multicast options 389 */ 390 if (imo != NULL) { 391 ip->ip_ttl = imo->imo_multicast_ttl; 392 if (imo->imo_multicast_vif != -1) { 393 ip->ip_src.s_addr = 394 ip_mcast_src ? 395 ip_mcast_src(imo->imo_multicast_vif) : 396 INADDR_ANY; 397 } 398 } else { 399 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 400 } 401 /* 402 * Confirm that the outgoing interface supports multicast. 403 */ 404 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 405 if (!(ifp->if_flags & IFF_MULTICAST)) { 406 ipstat.ips_noroute++; 407 error = ENETUNREACH; 408 goto bad; 409 } 410 } 411 /* 412 * If source address not specified yet, use address 413 * of outgoing interface. 414 */ 415 if (ip->ip_src.s_addr == INADDR_ANY) { 416 /* Interface may have no addresses. */ 417 if (ia != NULL) 418 ip->ip_src = IA_SIN(ia)->sin_addr; 419 } 420 421 IN_LOOKUP_MULTI(pkt_dst, ifp, inm); 422 if (inm != NULL && 423 (imo == NULL || imo->imo_multicast_loop)) { 424 /* 425 * If we belong to the destination multicast group 426 * on the outgoing interface, and the caller did not 427 * forbid loopback, loop back a copy. 428 */ 429 ip_mloopback(ifp, m, dst, hlen); 430 } else { 431 /* 432 * If we are acting as a multicast router, perform 433 * multicast forwarding as if the packet had just 434 * arrived on the interface to which we are about 435 * to send. The multicast forwarding function 436 * recursively calls this function, using the 437 * IP_FORWARDING flag to prevent infinite recursion. 438 * 439 * Multicasts that are looped back by ip_mloopback(), 440 * above, will be forwarded by the ip_input() routine, 441 * if necessary. 442 */ 443 if (ip_mrouter && !(flags & IP_FORWARDING)) { 444 /* 445 * If rsvp daemon is not running, do not 446 * set ip_moptions. This ensures that the packet 447 * is multicast and not just sent down one link 448 * as prescribed by rsvpd. 449 */ 450 if (!rsvp_on) 451 imo = NULL; 452 if (ip_mforward) { 453 get_mplock(); 454 if (ip_mforward(ip, ifp, m, imo) != 0) { 455 m_freem(m); 456 rel_mplock(); 457 goto done; 458 } 459 rel_mplock(); 460 } 461 } 462 } 463 464 /* 465 * Multicasts with a time-to-live of zero may be looped- 466 * back, above, but must not be transmitted on a network. 467 * Also, multicasts addressed to the loopback interface 468 * are not sent -- the above call to ip_mloopback() will 469 * loop back a copy if this host actually belongs to the 470 * destination group on the loopback interface. 471 */ 472 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 473 m_freem(m); 474 goto done; 475 } 476 477 goto sendit; 478 } else { 479 m->m_flags &= ~M_MCAST; 480 } 481 482 /* 483 * If the source address is not specified yet, use the address 484 * of the outoing interface. In case, keep note we did that, so 485 * if the the firewall changes the next-hop causing the output 486 * interface to change, we can fix that. 487 */ 488 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) { 489 /* Interface may have no addresses. */ 490 if (ia != NULL) { 491 ip->ip_src = IA_SIN(ia)->sin_addr; 492 src_was_INADDR_ANY = 1; 493 } 494 } 495 496 #ifdef ALTQ 497 /* 498 * Disable packet drop hack. 499 * Packetdrop should be done by queueing. 500 */ 501 #else /* !ALTQ */ 502 /* 503 * Verify that we have any chance at all of being able to queue 504 * the packet or packet fragments 505 */ 506 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 507 ifp->if_snd.ifq_maxlen) { 508 error = ENOBUFS; 509 ipstat.ips_odropped++; 510 goto bad; 511 } 512 #endif /* !ALTQ */ 513 514 /* 515 * Look for broadcast address and 516 * verify user is allowed to send 517 * such a packet. 518 */ 519 if (isbroadcast) { 520 if (!(ifp->if_flags & IFF_BROADCAST)) { 521 error = EADDRNOTAVAIL; 522 goto bad; 523 } 524 if (!(flags & IP_ALLOWBROADCAST)) { 525 error = EACCES; 526 goto bad; 527 } 528 /* don't allow broadcast messages to be fragmented */ 529 if (ip->ip_len > ifp->if_mtu) { 530 error = EMSGSIZE; 531 goto bad; 532 } 533 m->m_flags |= M_BCAST; 534 } else { 535 m->m_flags &= ~M_BCAST; 536 } 537 538 sendit: 539 #ifdef IPSEC 540 /* get SP for this packet */ 541 if (so == NULL) 542 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 543 else 544 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 545 546 if (sp == NULL) { 547 ipsecstat.out_inval++; 548 goto bad; 549 } 550 551 error = 0; 552 553 /* check policy */ 554 switch (sp->policy) { 555 case IPSEC_POLICY_DISCARD: 556 /* 557 * This packet is just discarded. 558 */ 559 ipsecstat.out_polvio++; 560 goto bad; 561 562 case IPSEC_POLICY_BYPASS: 563 case IPSEC_POLICY_NONE: 564 case IPSEC_POLICY_TCP: 565 /* no need to do IPsec. */ 566 goto skip_ipsec; 567 568 case IPSEC_POLICY_IPSEC: 569 if (sp->req == NULL) { 570 /* acquire a policy */ 571 error = key_spdacquire(sp); 572 goto bad; 573 } 574 break; 575 576 case IPSEC_POLICY_ENTRUST: 577 default: 578 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 579 } 580 { 581 struct ipsec_output_state state; 582 bzero(&state, sizeof state); 583 state.m = m; 584 if (flags & IP_ROUTETOIF) { 585 state.ro = &iproute; 586 bzero(&iproute, sizeof iproute); 587 } else 588 state.ro = ro; 589 state.dst = (struct sockaddr *)dst; 590 591 ip->ip_sum = 0; 592 593 /* 594 * XXX 595 * delayed checksums are not currently compatible with IPsec 596 */ 597 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 598 in_delayed_cksum(m); 599 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 600 } 601 602 ip->ip_len = htons(ip->ip_len); 603 ip->ip_off = htons(ip->ip_off); 604 605 error = ipsec4_output(&state, sp, flags); 606 607 m = state.m; 608 if (flags & IP_ROUTETOIF) { 609 /* 610 * if we have tunnel mode SA, we may need to ignore 611 * IP_ROUTETOIF. 612 */ 613 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 614 flags &= ~IP_ROUTETOIF; 615 ro = state.ro; 616 } 617 } else 618 ro = state.ro; 619 dst = (struct sockaddr_in *)state.dst; 620 if (error) { 621 /* mbuf is already reclaimed in ipsec4_output. */ 622 m0 = NULL; 623 switch (error) { 624 case EHOSTUNREACH: 625 case ENETUNREACH: 626 case EMSGSIZE: 627 case ENOBUFS: 628 case ENOMEM: 629 break; 630 default: 631 kprintf("ip4_output (ipsec): error code %d\n", error); 632 /*fall through*/ 633 case ENOENT: 634 /* don't show these error codes to the user */ 635 error = 0; 636 break; 637 } 638 goto bad; 639 } 640 } 641 642 /* be sure to update variables that are affected by ipsec4_output() */ 643 ip = mtod(m, struct ip *); 644 #ifdef _IP_VHL 645 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 646 #else 647 hlen = ip->ip_hl << 2; 648 #endif 649 if (ro->ro_rt == NULL) { 650 if (!(flags & IP_ROUTETOIF)) { 651 kprintf("ip_output: " 652 "can't update route after IPsec processing\n"); 653 error = EHOSTUNREACH; /*XXX*/ 654 goto bad; 655 } 656 } else { 657 ia = ifatoia(ro->ro_rt->rt_ifa); 658 ifp = ro->ro_rt->rt_ifp; 659 } 660 661 /* make it flipped, again. */ 662 ip->ip_len = ntohs(ip->ip_len); 663 ip->ip_off = ntohs(ip->ip_off); 664 skip_ipsec: 665 #endif /*IPSEC*/ 666 #ifdef FAST_IPSEC 667 /* 668 * Check the security policy (SP) for the packet and, if 669 * required, do IPsec-related processing. There are two 670 * cases here; the first time a packet is sent through 671 * it will be untagged and handled by ipsec4_checkpolicy. 672 * If the packet is resubmitted to ip_output (e.g. after 673 * AH, ESP, etc. processing), there will be a tag to bypass 674 * the lookup and related policy checking. 675 */ 676 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 677 crit_enter(); 678 if (mtag != NULL) { 679 tdbi = (struct tdb_ident *)m_tag_data(mtag); 680 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 681 if (sp == NULL) 682 error = -EINVAL; /* force silent drop */ 683 m_tag_delete(m, mtag); 684 } else { 685 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 686 &error, inp); 687 } 688 /* 689 * There are four return cases: 690 * sp != NULL apply IPsec policy 691 * sp == NULL, error == 0 no IPsec handling needed 692 * sp == NULL, error == -EINVAL discard packet w/o error 693 * sp == NULL, error != 0 discard packet, report error 694 */ 695 if (sp != NULL) { 696 /* Loop detection, check if ipsec processing already done */ 697 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 698 for (mtag = m_tag_first(m); mtag != NULL; 699 mtag = m_tag_next(m, mtag)) { 700 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 701 continue; 702 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 703 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 704 continue; 705 /* 706 * Check if policy has an SA associated with it. 707 * This can happen when an SP has yet to acquire 708 * an SA; e.g. on first reference. If it occurs, 709 * then we let ipsec4_process_packet do its thing. 710 */ 711 if (sp->req->sav == NULL) 712 break; 713 tdbi = (struct tdb_ident *)m_tag_data(mtag); 714 if (tdbi->spi == sp->req->sav->spi && 715 tdbi->proto == sp->req->sav->sah->saidx.proto && 716 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 717 sizeof(union sockaddr_union)) == 0) { 718 /* 719 * No IPsec processing is needed, free 720 * reference to SP. 721 * 722 * NB: null pointer to avoid free at 723 * done: below. 724 */ 725 KEY_FREESP(&sp), sp = NULL; 726 crit_exit(); 727 goto spd_done; 728 } 729 } 730 731 /* 732 * Do delayed checksums now because we send before 733 * this is done in the normal processing path. 734 */ 735 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 736 in_delayed_cksum(m); 737 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 738 } 739 740 ip->ip_len = htons(ip->ip_len); 741 ip->ip_off = htons(ip->ip_off); 742 743 /* NB: callee frees mbuf */ 744 error = ipsec4_process_packet(m, sp->req, flags, 0); 745 /* 746 * Preserve KAME behaviour: ENOENT can be returned 747 * when an SA acquire is in progress. Don't propagate 748 * this to user-level; it confuses applications. 749 * 750 * XXX this will go away when the SADB is redone. 751 */ 752 if (error == ENOENT) 753 error = 0; 754 crit_exit(); 755 goto done; 756 } else { 757 crit_exit(); 758 759 if (error != 0) { 760 /* 761 * Hack: -EINVAL is used to signal that a packet 762 * should be silently discarded. This is typically 763 * because we asked key management for an SA and 764 * it was delayed (e.g. kicked up to IKE). 765 */ 766 if (error == -EINVAL) 767 error = 0; 768 goto bad; 769 } else { 770 /* No IPsec processing for this packet. */ 771 } 772 #ifdef notyet 773 /* 774 * If deferred crypto processing is needed, check that 775 * the interface supports it. 776 */ 777 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 778 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 779 /* notify IPsec to do its own crypto */ 780 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 781 error = EHOSTUNREACH; 782 goto bad; 783 } 784 #endif 785 } 786 spd_done: 787 #endif /* FAST_IPSEC */ 788 789 /* We are already being fwd'd from a firewall. */ 790 if (next_hop != NULL) 791 goto pass; 792 793 /* No pfil hooks */ 794 if (!pfil_has_hooks(&inet_pfil_hook)) { 795 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 796 /* 797 * Strip dummynet tags from stranded packets 798 */ 799 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 800 KKASSERT(mtag != NULL); 801 m_tag_delete(m, mtag); 802 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 803 } 804 goto pass; 805 } 806 807 /* 808 * IpHack's section. 809 * - Xlate: translate packet's addr/port (NAT). 810 * - Firewall: deny/allow/etc. 811 * - Wrap: fake packet's addr/port <unimpl.> 812 * - Encapsulate: put it in another IP and send out. <unimp.> 813 */ 814 815 /* 816 * Run through list of hooks for output packets. 817 */ 818 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 819 if (error != 0 || m == NULL) 820 goto done; 821 ip = mtod(m, struct ip *); 822 823 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 824 /* 825 * Check dst to make sure it is directly reachable on the 826 * interface we previously thought it was. 827 * If it isn't (which may be likely in some situations) we have 828 * to re-route it (ie, find a route for the next-hop and the 829 * associated interface) and set them here. This is nested 830 * forwarding which in most cases is undesirable, except where 831 * such control is nigh impossible. So we do it here. 832 * And I'm babbling. 833 */ 834 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 835 KKASSERT(mtag != NULL); 836 next_hop = m_tag_data(mtag); 837 838 /* 839 * Try local forwarding first 840 */ 841 if (ip_localforward(m, next_hop, hlen)) 842 goto done; 843 844 /* 845 * Relocate the route based on next_hop. 846 * If the current route is inp's cache, keep it untouched. 847 */ 848 if (ro == &iproute && ro->ro_rt != NULL) { 849 RTFREE(ro->ro_rt); 850 ro->ro_rt = NULL; 851 } 852 ro = &iproute; 853 bzero(ro, sizeof *ro); 854 855 /* 856 * Forwarding to broadcast address is not allowed. 857 * XXX Should we follow IP_ROUTETOIF? 858 */ 859 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF); 860 861 /* We are doing forwarding now */ 862 flags |= IP_FORWARDING; 863 864 goto reroute; 865 } 866 867 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 868 struct dn_pkt *dn_pkt; 869 870 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 871 KKASSERT(mtag != NULL); 872 dn_pkt = m_tag_data(mtag); 873 874 /* 875 * Under certain cases it is not possible to recalculate 876 * 'ro' and 'dst', let alone 'flags', so just save them in 877 * dummynet tag and avoid the possible wrong reculcalation 878 * when we come back to ip_output() again. 879 * 880 * All other parameters have been already used and so they 881 * are not needed anymore. 882 * XXX if the ifp is deleted while a pkt is in dummynet, 883 * we are in trouble! (TODO use ifnet_detach_event) 884 * 885 * We need to copy *ro because for ICMP pkts (and maybe 886 * others) the caller passed a pointer into the stack; 887 * dst might also be a pointer into *ro so it needs to 888 * be updated. 889 */ 890 dn_pkt->ro = *ro; 891 if (ro->ro_rt) 892 ro->ro_rt->rt_refcnt++; 893 if (dst == (struct sockaddr_in *)&ro->ro_dst) { 894 /* 'dst' points into 'ro' */ 895 dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst); 896 } 897 dn_pkt->dn_dst = dst; 898 dn_pkt->flags = flags; 899 900 ip_dn_queue(m); 901 goto done; 902 } 903 pass: 904 /* 127/8 must not appear on wire - RFC1122. */ 905 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 906 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 907 if (!(ifp->if_flags & IFF_LOOPBACK)) { 908 ipstat.ips_badaddr++; 909 error = EADDRNOTAVAIL; 910 goto bad; 911 } 912 } 913 914 m->m_pkthdr.csum_flags |= CSUM_IP; 915 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 916 if (sw_csum & CSUM_DELAY_DATA) { 917 in_delayed_cksum(m); 918 sw_csum &= ~CSUM_DELAY_DATA; 919 } 920 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 921 922 /* 923 * If small enough for interface, or the interface will take 924 * care of the fragmentation for us, can just send directly. 925 */ 926 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) && 927 !(ip->ip_off & IP_DF))) { 928 ip->ip_len = htons(ip->ip_len); 929 ip->ip_off = htons(ip->ip_off); 930 ip->ip_sum = 0; 931 if (sw_csum & CSUM_DELAY_IP) { 932 if (ip->ip_vhl == IP_VHL_BORING) 933 ip->ip_sum = in_cksum_hdr(ip); 934 else 935 ip->ip_sum = in_cksum(m, hlen); 936 } 937 938 /* Record statistics for this interface address. */ 939 if (!(flags & IP_FORWARDING) && ia) { 940 ia->ia_ifa.if_opackets++; 941 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 942 } 943 944 #ifdef IPSEC 945 /* clean ipsec history once it goes out of the node */ 946 ipsec_delaux(m); 947 #endif 948 949 #ifdef MBUF_STRESS_TEST 950 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 951 struct mbuf *m1, *m2; 952 int length, tmp; 953 954 tmp = length = m->m_pkthdr.len; 955 956 while ((length -= mbuf_frag_size) >= 1) { 957 m1 = m_split(m, length, MB_DONTWAIT); 958 if (m1 == NULL) 959 break; 960 m2 = m; 961 while (m2->m_next != NULL) 962 m2 = m2->m_next; 963 m2->m_next = m1; 964 } 965 m->m_pkthdr.len = tmp; 966 } 967 #endif 968 969 #ifdef MPLS 970 if (!mpls_output_process(m, ro->ro_rt)) 971 goto done; 972 #endif 973 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 974 ro->ro_rt); 975 goto done; 976 } 977 978 if (ip->ip_off & IP_DF) { 979 error = EMSGSIZE; 980 /* 981 * This case can happen if the user changed the MTU 982 * of an interface after enabling IP on it. Because 983 * most netifs don't keep track of routes pointing to 984 * them, there is no way for one to update all its 985 * routes when the MTU is changed. 986 */ 987 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 988 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 989 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 990 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 991 } 992 ipstat.ips_cantfrag++; 993 goto bad; 994 } 995 996 /* 997 * Too large for interface; fragment if possible. If successful, 998 * on return, m will point to a list of packets to be sent. 999 */ 1000 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1001 if (error) 1002 goto bad; 1003 for (; m; m = m0) { 1004 m0 = m->m_nextpkt; 1005 m->m_nextpkt = NULL; 1006 #ifdef IPSEC 1007 /* clean ipsec history once it goes out of the node */ 1008 ipsec_delaux(m); 1009 #endif 1010 if (error == 0) { 1011 /* Record statistics for this interface address. */ 1012 if (ia != NULL) { 1013 ia->ia_ifa.if_opackets++; 1014 ia->ia_ifa.if_obytes += m->m_pkthdr.len; 1015 } 1016 #ifdef MPLS 1017 if (!mpls_output_process(m, ro->ro_rt)) 1018 continue; 1019 #endif 1020 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 1021 ro->ro_rt); 1022 } else { 1023 m_freem(m); 1024 } 1025 } 1026 1027 if (error == 0) 1028 ipstat.ips_fragmented++; 1029 1030 done: 1031 if (ro == &iproute && ro->ro_rt != NULL) { 1032 RTFREE(ro->ro_rt); 1033 ro->ro_rt = NULL; 1034 } 1035 #ifdef IPSEC 1036 if (sp != NULL) { 1037 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1038 kprintf("DP ip_output call free SP:%p\n", sp)); 1039 key_freesp(sp); 1040 } 1041 #endif 1042 #ifdef FAST_IPSEC 1043 if (sp != NULL) 1044 KEY_FREESP(&sp); 1045 #endif 1046 return (error); 1047 bad: 1048 m_freem(m); 1049 goto done; 1050 } 1051 1052 /* 1053 * Create a chain of fragments which fit the given mtu. m_frag points to the 1054 * mbuf to be fragmented; on return it points to the chain with the fragments. 1055 * Return 0 if no error. If error, m_frag may contain a partially built 1056 * chain of fragments that should be freed by the caller. 1057 * 1058 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1059 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1060 */ 1061 int 1062 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1063 u_long if_hwassist_flags, int sw_csum) 1064 { 1065 int error = 0; 1066 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1067 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1068 int off; 1069 struct mbuf *m0 = *m_frag; /* the original packet */ 1070 int firstlen; 1071 struct mbuf **mnext; 1072 int nfrags; 1073 1074 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1075 ipstat.ips_cantfrag++; 1076 return EMSGSIZE; 1077 } 1078 1079 /* 1080 * Must be able to put at least 8 bytes per fragment. 1081 */ 1082 if (len < 8) 1083 return EMSGSIZE; 1084 1085 /* 1086 * If the interface will not calculate checksums on 1087 * fragmented packets, then do it here. 1088 */ 1089 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1090 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1091 in_delayed_cksum(m0); 1092 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1093 } 1094 1095 if (len > PAGE_SIZE) { 1096 /* 1097 * Fragment large datagrams such that each segment 1098 * contains a multiple of PAGE_SIZE amount of data, 1099 * plus headers. This enables a receiver to perform 1100 * page-flipping zero-copy optimizations. 1101 * 1102 * XXX When does this help given that sender and receiver 1103 * could have different page sizes, and also mtu could 1104 * be less than the receiver's page size ? 1105 */ 1106 int newlen; 1107 struct mbuf *m; 1108 1109 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1110 off += m->m_len; 1111 1112 /* 1113 * firstlen (off - hlen) must be aligned on an 1114 * 8-byte boundary 1115 */ 1116 if (off < hlen) 1117 goto smart_frag_failure; 1118 off = ((off - hlen) & ~7) + hlen; 1119 newlen = (~PAGE_MASK) & mtu; 1120 if ((newlen + sizeof(struct ip)) > mtu) { 1121 /* we failed, go back the default */ 1122 smart_frag_failure: 1123 newlen = len; 1124 off = hlen + len; 1125 } 1126 len = newlen; 1127 1128 } else { 1129 off = hlen + len; 1130 } 1131 1132 firstlen = off - hlen; 1133 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1134 1135 /* 1136 * Loop through length of segment after first fragment, 1137 * make new header and copy data of each part and link onto chain. 1138 * Here, m0 is the original packet, m is the fragment being created. 1139 * The fragments are linked off the m_nextpkt of the original 1140 * packet, which after processing serves as the first fragment. 1141 */ 1142 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1143 struct ip *mhip; /* ip header on the fragment */ 1144 struct mbuf *m; 1145 int mhlen = sizeof(struct ip); 1146 1147 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1148 if (m == NULL) { 1149 error = ENOBUFS; 1150 ipstat.ips_odropped++; 1151 goto done; 1152 } 1153 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1154 /* 1155 * In the first mbuf, leave room for the link header, then 1156 * copy the original IP header including options. The payload 1157 * goes into an additional mbuf chain returned by m_copy(). 1158 */ 1159 m->m_data += max_linkhdr; 1160 mhip = mtod(m, struct ip *); 1161 *mhip = *ip; 1162 if (hlen > sizeof(struct ip)) { 1163 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1164 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1165 } 1166 m->m_len = mhlen; 1167 /* XXX do we need to add ip->ip_off below ? */ 1168 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1169 if (off + len >= ip->ip_len) { /* last fragment */ 1170 len = ip->ip_len - off; 1171 m->m_flags |= M_LASTFRAG; 1172 } else 1173 mhip->ip_off |= IP_MF; 1174 mhip->ip_len = htons((u_short)(len + mhlen)); 1175 m->m_next = m_copy(m0, off, len); 1176 if (m->m_next == NULL) { /* copy failed */ 1177 m_free(m); 1178 error = ENOBUFS; /* ??? */ 1179 ipstat.ips_odropped++; 1180 goto done; 1181 } 1182 m->m_pkthdr.len = mhlen + len; 1183 m->m_pkthdr.rcvif = NULL; 1184 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1185 mhip->ip_off = htons(mhip->ip_off); 1186 mhip->ip_sum = 0; 1187 if (sw_csum & CSUM_DELAY_IP) 1188 mhip->ip_sum = in_cksum(m, mhlen); 1189 *mnext = m; 1190 mnext = &m->m_nextpkt; 1191 } 1192 ipstat.ips_ofragments += nfrags; 1193 1194 /* set first marker for fragment chain */ 1195 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1196 m0->m_pkthdr.csum_data = nfrags; 1197 1198 /* 1199 * Update first fragment by trimming what's been copied out 1200 * and updating header. 1201 */ 1202 m_adj(m0, hlen + firstlen - ip->ip_len); 1203 m0->m_pkthdr.len = hlen + firstlen; 1204 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1205 ip->ip_off |= IP_MF; 1206 ip->ip_off = htons(ip->ip_off); 1207 ip->ip_sum = 0; 1208 if (sw_csum & CSUM_DELAY_IP) 1209 ip->ip_sum = in_cksum(m0, hlen); 1210 1211 done: 1212 *m_frag = m0; 1213 return error; 1214 } 1215 1216 void 1217 in_delayed_cksum(struct mbuf *m) 1218 { 1219 struct ip *ip; 1220 u_short csum, offset; 1221 1222 ip = mtod(m, struct ip *); 1223 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1224 csum = in_cksum_skip(m, ip->ip_len, offset); 1225 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1226 csum = 0xffff; 1227 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1228 1229 if (offset + sizeof(u_short) > m->m_len) { 1230 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1231 m->m_len, offset, ip->ip_p); 1232 /* 1233 * XXX 1234 * this shouldn't happen, but if it does, the 1235 * correct behavior may be to insert the checksum 1236 * in the existing chain instead of rearranging it. 1237 */ 1238 m = m_pullup(m, offset + sizeof(u_short)); 1239 } 1240 *(u_short *)(m->m_data + offset) = csum; 1241 } 1242 1243 /* 1244 * Insert IP options into preformed packet. 1245 * Adjust IP destination as required for IP source routing, 1246 * as indicated by a non-zero in_addr at the start of the options. 1247 * 1248 * XXX This routine assumes that the packet has no options in place. 1249 */ 1250 static struct mbuf * 1251 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1252 { 1253 struct ipoption *p = mtod(opt, struct ipoption *); 1254 struct mbuf *n; 1255 struct ip *ip = mtod(m, struct ip *); 1256 unsigned optlen; 1257 1258 optlen = opt->m_len - sizeof p->ipopt_dst; 1259 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1260 *phlen = 0; 1261 return (m); /* XXX should fail */ 1262 } 1263 if (p->ipopt_dst.s_addr) 1264 ip->ip_dst = p->ipopt_dst; 1265 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1266 MGETHDR(n, MB_DONTWAIT, MT_HEADER); 1267 if (n == NULL) { 1268 *phlen = 0; 1269 return (m); 1270 } 1271 n->m_pkthdr.rcvif = NULL; 1272 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1273 m->m_len -= sizeof(struct ip); 1274 m->m_data += sizeof(struct ip); 1275 n->m_next = m; 1276 m = n; 1277 m->m_len = optlen + sizeof(struct ip); 1278 m->m_data += max_linkhdr; 1279 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1280 } else { 1281 m->m_data -= optlen; 1282 m->m_len += optlen; 1283 m->m_pkthdr.len += optlen; 1284 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1285 } 1286 ip = mtod(m, struct ip *); 1287 bcopy(p->ipopt_list, ip + 1, optlen); 1288 *phlen = sizeof(struct ip) + optlen; 1289 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1290 ip->ip_len += optlen; 1291 return (m); 1292 } 1293 1294 /* 1295 * Copy options from ip to jp, 1296 * omitting those not copied during fragmentation. 1297 */ 1298 int 1299 ip_optcopy(struct ip *ip, struct ip *jp) 1300 { 1301 u_char *cp, *dp; 1302 int opt, optlen, cnt; 1303 1304 cp = (u_char *)(ip + 1); 1305 dp = (u_char *)(jp + 1); 1306 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1307 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1308 opt = cp[0]; 1309 if (opt == IPOPT_EOL) 1310 break; 1311 if (opt == IPOPT_NOP) { 1312 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1313 *dp++ = IPOPT_NOP; 1314 optlen = 1; 1315 continue; 1316 } 1317 1318 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1319 ("ip_optcopy: malformed ipv4 option")); 1320 optlen = cp[IPOPT_OLEN]; 1321 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1322 ("ip_optcopy: malformed ipv4 option")); 1323 1324 /* bogus lengths should have been caught by ip_dooptions */ 1325 if (optlen > cnt) 1326 optlen = cnt; 1327 if (IPOPT_COPIED(opt)) { 1328 bcopy(cp, dp, optlen); 1329 dp += optlen; 1330 } 1331 } 1332 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1333 *dp++ = IPOPT_EOL; 1334 return (optlen); 1335 } 1336 1337 /* 1338 * IP socket option processing. 1339 */ 1340 void 1341 ip_ctloutput(netmsg_t msg) 1342 { 1343 struct socket *so = msg->base.nm_so; 1344 struct sockopt *sopt = msg->ctloutput.nm_sopt; 1345 struct inpcb *inp = so->so_pcb; 1346 int error, optval; 1347 1348 error = optval = 0; 1349 if (sopt->sopt_level != IPPROTO_IP) { 1350 error = EINVAL; 1351 goto done; 1352 } 1353 1354 switch (sopt->sopt_dir) { 1355 case SOPT_SET: 1356 switch (sopt->sopt_name) { 1357 case IP_OPTIONS: 1358 #ifdef notyet 1359 case IP_RETOPTS: 1360 #endif 1361 { 1362 struct mbuf *m; 1363 if (sopt->sopt_valsize > MLEN) { 1364 error = EMSGSIZE; 1365 break; 1366 } 1367 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER); 1368 if (m == NULL) { 1369 error = ENOBUFS; 1370 break; 1371 } 1372 m->m_len = sopt->sopt_valsize; 1373 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len, 1374 m->m_len); 1375 error = ip_pcbopts(sopt->sopt_name, 1376 &inp->inp_options, m); 1377 goto done; 1378 } 1379 1380 case IP_TOS: 1381 case IP_TTL: 1382 case IP_MINTTL: 1383 case IP_RECVOPTS: 1384 case IP_RECVRETOPTS: 1385 case IP_RECVDSTADDR: 1386 case IP_RECVIF: 1387 case IP_RECVTTL: 1388 case IP_FAITH: 1389 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1390 sizeof optval); 1391 if (error) 1392 break; 1393 switch (sopt->sopt_name) { 1394 case IP_TOS: 1395 inp->inp_ip_tos = optval; 1396 break; 1397 1398 case IP_TTL: 1399 inp->inp_ip_ttl = optval; 1400 break; 1401 case IP_MINTTL: 1402 if (optval >= 0 && optval <= MAXTTL) 1403 inp->inp_ip_minttl = optval; 1404 else 1405 error = EINVAL; 1406 break; 1407 #define OPTSET(bit) \ 1408 if (optval) \ 1409 inp->inp_flags |= bit; \ 1410 else \ 1411 inp->inp_flags &= ~bit; 1412 1413 case IP_RECVOPTS: 1414 OPTSET(INP_RECVOPTS); 1415 break; 1416 1417 case IP_RECVRETOPTS: 1418 OPTSET(INP_RECVRETOPTS); 1419 break; 1420 1421 case IP_RECVDSTADDR: 1422 OPTSET(INP_RECVDSTADDR); 1423 break; 1424 1425 case IP_RECVIF: 1426 OPTSET(INP_RECVIF); 1427 break; 1428 1429 case IP_RECVTTL: 1430 OPTSET(INP_RECVTTL); 1431 break; 1432 1433 case IP_FAITH: 1434 OPTSET(INP_FAITH); 1435 break; 1436 } 1437 break; 1438 #undef OPTSET 1439 1440 case IP_MULTICAST_IF: 1441 case IP_MULTICAST_VIF: 1442 case IP_MULTICAST_TTL: 1443 case IP_MULTICAST_LOOP: 1444 case IP_ADD_MEMBERSHIP: 1445 case IP_DROP_MEMBERSHIP: 1446 error = ip_setmoptions(sopt, &inp->inp_moptions); 1447 break; 1448 1449 case IP_PORTRANGE: 1450 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1451 sizeof optval); 1452 if (error) 1453 break; 1454 1455 switch (optval) { 1456 case IP_PORTRANGE_DEFAULT: 1457 inp->inp_flags &= ~(INP_LOWPORT); 1458 inp->inp_flags &= ~(INP_HIGHPORT); 1459 break; 1460 1461 case IP_PORTRANGE_HIGH: 1462 inp->inp_flags &= ~(INP_LOWPORT); 1463 inp->inp_flags |= INP_HIGHPORT; 1464 break; 1465 1466 case IP_PORTRANGE_LOW: 1467 inp->inp_flags &= ~(INP_HIGHPORT); 1468 inp->inp_flags |= INP_LOWPORT; 1469 break; 1470 1471 default: 1472 error = EINVAL; 1473 break; 1474 } 1475 break; 1476 1477 #if defined(IPSEC) || defined(FAST_IPSEC) 1478 case IP_IPSEC_POLICY: 1479 { 1480 caddr_t req; 1481 size_t len = 0; 1482 int priv; 1483 struct mbuf *m; 1484 int optname; 1485 1486 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1487 break; 1488 soopt_to_mbuf(sopt, m); 1489 priv = (sopt->sopt_td != NULL && 1490 priv_check(sopt->sopt_td, PRIV_ROOT) != 0) ? 0 : 1; 1491 req = mtod(m, caddr_t); 1492 len = m->m_len; 1493 optname = sopt->sopt_name; 1494 error = ipsec4_set_policy(inp, optname, req, len, priv); 1495 m_freem(m); 1496 break; 1497 } 1498 #endif /*IPSEC*/ 1499 1500 default: 1501 error = ENOPROTOOPT; 1502 break; 1503 } 1504 break; 1505 1506 case SOPT_GET: 1507 switch (sopt->sopt_name) { 1508 case IP_OPTIONS: 1509 case IP_RETOPTS: 1510 if (inp->inp_options) 1511 soopt_from_kbuf(sopt, mtod(inp->inp_options, 1512 char *), 1513 inp->inp_options->m_len); 1514 else 1515 sopt->sopt_valsize = 0; 1516 break; 1517 1518 case IP_TOS: 1519 case IP_TTL: 1520 case IP_MINTTL: 1521 case IP_RECVOPTS: 1522 case IP_RECVRETOPTS: 1523 case IP_RECVDSTADDR: 1524 case IP_RECVTTL: 1525 case IP_RECVIF: 1526 case IP_PORTRANGE: 1527 case IP_FAITH: 1528 switch (sopt->sopt_name) { 1529 1530 case IP_TOS: 1531 optval = inp->inp_ip_tos; 1532 break; 1533 1534 case IP_TTL: 1535 optval = inp->inp_ip_ttl; 1536 break; 1537 case IP_MINTTL: 1538 optval = inp->inp_ip_minttl; 1539 break; 1540 1541 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1542 1543 case IP_RECVOPTS: 1544 optval = OPTBIT(INP_RECVOPTS); 1545 break; 1546 1547 case IP_RECVRETOPTS: 1548 optval = OPTBIT(INP_RECVRETOPTS); 1549 break; 1550 1551 case IP_RECVDSTADDR: 1552 optval = OPTBIT(INP_RECVDSTADDR); 1553 break; 1554 1555 case IP_RECVTTL: 1556 optval = OPTBIT(INP_RECVTTL); 1557 break; 1558 1559 case IP_RECVIF: 1560 optval = OPTBIT(INP_RECVIF); 1561 break; 1562 1563 case IP_PORTRANGE: 1564 if (inp->inp_flags & INP_HIGHPORT) 1565 optval = IP_PORTRANGE_HIGH; 1566 else if (inp->inp_flags & INP_LOWPORT) 1567 optval = IP_PORTRANGE_LOW; 1568 else 1569 optval = 0; 1570 break; 1571 1572 case IP_FAITH: 1573 optval = OPTBIT(INP_FAITH); 1574 break; 1575 } 1576 soopt_from_kbuf(sopt, &optval, sizeof optval); 1577 break; 1578 1579 case IP_MULTICAST_IF: 1580 case IP_MULTICAST_VIF: 1581 case IP_MULTICAST_TTL: 1582 case IP_MULTICAST_LOOP: 1583 case IP_ADD_MEMBERSHIP: 1584 case IP_DROP_MEMBERSHIP: 1585 error = ip_getmoptions(sopt, inp->inp_moptions); 1586 break; 1587 1588 #if defined(IPSEC) || defined(FAST_IPSEC) 1589 case IP_IPSEC_POLICY: 1590 { 1591 struct mbuf *m = NULL; 1592 caddr_t req = NULL; 1593 size_t len = 0; 1594 1595 if (m != NULL) { 1596 req = mtod(m, caddr_t); 1597 len = m->m_len; 1598 } 1599 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1600 if (error == 0) 1601 error = soopt_from_mbuf(sopt, m); /* XXX */ 1602 if (error == 0) 1603 m_freem(m); 1604 break; 1605 } 1606 #endif /*IPSEC*/ 1607 1608 default: 1609 error = ENOPROTOOPT; 1610 break; 1611 } 1612 break; 1613 } 1614 done: 1615 lwkt_replymsg(&msg->lmsg, error); 1616 } 1617 1618 /* 1619 * Set up IP options in pcb for insertion in output packets. 1620 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1621 * with destination address if source routed. 1622 */ 1623 static int 1624 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1625 { 1626 int cnt, optlen; 1627 u_char *cp; 1628 u_char opt; 1629 1630 /* turn off any old options */ 1631 if (*pcbopt) 1632 m_free(*pcbopt); 1633 *pcbopt = NULL; 1634 if (m == NULL || m->m_len == 0) { 1635 /* 1636 * Only turning off any previous options. 1637 */ 1638 if (m != NULL) 1639 m_free(m); 1640 return (0); 1641 } 1642 1643 if (m->m_len % sizeof(int32_t)) 1644 goto bad; 1645 /* 1646 * IP first-hop destination address will be stored before 1647 * actual options; move other options back 1648 * and clear it when none present. 1649 */ 1650 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1651 goto bad; 1652 cnt = m->m_len; 1653 m->m_len += sizeof(struct in_addr); 1654 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1655 ovbcopy(mtod(m, caddr_t), cp, cnt); 1656 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1657 1658 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1659 opt = cp[IPOPT_OPTVAL]; 1660 if (opt == IPOPT_EOL) 1661 break; 1662 if (opt == IPOPT_NOP) 1663 optlen = 1; 1664 else { 1665 if (cnt < IPOPT_OLEN + sizeof *cp) 1666 goto bad; 1667 optlen = cp[IPOPT_OLEN]; 1668 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1669 goto bad; 1670 } 1671 switch (opt) { 1672 1673 default: 1674 break; 1675 1676 case IPOPT_LSRR: 1677 case IPOPT_SSRR: 1678 /* 1679 * user process specifies route as: 1680 * ->A->B->C->D 1681 * D must be our final destination (but we can't 1682 * check that since we may not have connected yet). 1683 * A is first hop destination, which doesn't appear in 1684 * actual IP option, but is stored before the options. 1685 */ 1686 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1687 goto bad; 1688 m->m_len -= sizeof(struct in_addr); 1689 cnt -= sizeof(struct in_addr); 1690 optlen -= sizeof(struct in_addr); 1691 cp[IPOPT_OLEN] = optlen; 1692 /* 1693 * Move first hop before start of options. 1694 */ 1695 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1696 sizeof(struct in_addr)); 1697 /* 1698 * Then copy rest of options back 1699 * to close up the deleted entry. 1700 */ 1701 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1702 &cp[IPOPT_OFFSET+1], 1703 cnt - (IPOPT_MINOFF - 1)); 1704 break; 1705 } 1706 } 1707 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1708 goto bad; 1709 *pcbopt = m; 1710 return (0); 1711 1712 bad: 1713 m_free(m); 1714 return (EINVAL); 1715 } 1716 1717 /* 1718 * XXX 1719 * The whole multicast option thing needs to be re-thought. 1720 * Several of these options are equally applicable to non-multicast 1721 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1722 * standard option (IP_TTL). 1723 */ 1724 1725 /* 1726 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1727 */ 1728 static struct ifnet * 1729 ip_multicast_if(struct in_addr *a, int *ifindexp) 1730 { 1731 int ifindex; 1732 struct ifnet *ifp; 1733 1734 if (ifindexp) 1735 *ifindexp = 0; 1736 if (ntohl(a->s_addr) >> 24 == 0) { 1737 ifindex = ntohl(a->s_addr) & 0xffffff; 1738 if (ifindex < 0 || if_index < ifindex) 1739 return NULL; 1740 ifp = ifindex2ifnet[ifindex]; 1741 if (ifindexp) 1742 *ifindexp = ifindex; 1743 } else { 1744 ifp = INADDR_TO_IFP(a); 1745 } 1746 return ifp; 1747 } 1748 1749 /* 1750 * Set the IP multicast options in response to user setsockopt(). 1751 */ 1752 static int 1753 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1754 { 1755 int error = 0; 1756 int i; 1757 struct in_addr addr; 1758 struct ip_mreq mreq; 1759 struct ifnet *ifp; 1760 struct ip_moptions *imo = *imop; 1761 int ifindex; 1762 1763 if (imo == NULL) { 1764 /* 1765 * No multicast option buffer attached to the pcb; 1766 * allocate one and initialize to default values. 1767 */ 1768 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1769 1770 *imop = imo; 1771 imo->imo_multicast_ifp = NULL; 1772 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1773 imo->imo_multicast_vif = -1; 1774 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1775 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1776 imo->imo_num_memberships = 0; 1777 } 1778 switch (sopt->sopt_name) { 1779 /* store an index number for the vif you wanna use in the send */ 1780 case IP_MULTICAST_VIF: 1781 if (legal_vif_num == 0) { 1782 error = EOPNOTSUPP; 1783 break; 1784 } 1785 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i); 1786 if (error) 1787 break; 1788 if (!legal_vif_num(i) && (i != -1)) { 1789 error = EINVAL; 1790 break; 1791 } 1792 imo->imo_multicast_vif = i; 1793 break; 1794 1795 case IP_MULTICAST_IF: 1796 /* 1797 * Select the interface for outgoing multicast packets. 1798 */ 1799 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr); 1800 if (error) 1801 break; 1802 1803 /* 1804 * INADDR_ANY is used to remove a previous selection. 1805 * When no interface is selected, a default one is 1806 * chosen every time a multicast packet is sent. 1807 */ 1808 if (addr.s_addr == INADDR_ANY) { 1809 imo->imo_multicast_ifp = NULL; 1810 break; 1811 } 1812 /* 1813 * The selected interface is identified by its local 1814 * IP address. Find the interface and confirm that 1815 * it supports multicasting. 1816 */ 1817 crit_enter(); 1818 ifp = ip_multicast_if(&addr, &ifindex); 1819 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1820 crit_exit(); 1821 error = EADDRNOTAVAIL; 1822 break; 1823 } 1824 imo->imo_multicast_ifp = ifp; 1825 if (ifindex) 1826 imo->imo_multicast_addr = addr; 1827 else 1828 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1829 crit_exit(); 1830 break; 1831 1832 case IP_MULTICAST_TTL: 1833 /* 1834 * Set the IP time-to-live for outgoing multicast packets. 1835 * The original multicast API required a char argument, 1836 * which is inconsistent with the rest of the socket API. 1837 * We allow either a char or an int. 1838 */ 1839 if (sopt->sopt_valsize == 1) { 1840 u_char ttl; 1841 error = soopt_to_kbuf(sopt, &ttl, 1, 1); 1842 if (error) 1843 break; 1844 imo->imo_multicast_ttl = ttl; 1845 } else { 1846 u_int ttl; 1847 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl); 1848 if (error) 1849 break; 1850 if (ttl > 255) 1851 error = EINVAL; 1852 else 1853 imo->imo_multicast_ttl = ttl; 1854 } 1855 break; 1856 1857 case IP_MULTICAST_LOOP: 1858 /* 1859 * Set the loopback flag for outgoing multicast packets. 1860 * Must be zero or one. The original multicast API required a 1861 * char argument, which is inconsistent with the rest 1862 * of the socket API. We allow either a char or an int. 1863 */ 1864 if (sopt->sopt_valsize == 1) { 1865 u_char loop; 1866 1867 error = soopt_to_kbuf(sopt, &loop, 1, 1); 1868 if (error) 1869 break; 1870 imo->imo_multicast_loop = !!loop; 1871 } else { 1872 u_int loop; 1873 1874 error = soopt_to_kbuf(sopt, &loop, sizeof loop, 1875 sizeof loop); 1876 if (error) 1877 break; 1878 imo->imo_multicast_loop = !!loop; 1879 } 1880 break; 1881 1882 case IP_ADD_MEMBERSHIP: 1883 /* 1884 * Add a multicast group membership. 1885 * Group must be a valid IP multicast address. 1886 */ 1887 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1888 if (error) 1889 break; 1890 1891 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1892 error = EINVAL; 1893 break; 1894 } 1895 crit_enter(); 1896 /* 1897 * If no interface address was provided, use the interface of 1898 * the route to the given multicast address. 1899 */ 1900 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1901 struct sockaddr_in dst; 1902 struct rtentry *rt; 1903 1904 bzero(&dst, sizeof(struct sockaddr_in)); 1905 dst.sin_len = sizeof(struct sockaddr_in); 1906 dst.sin_family = AF_INET; 1907 dst.sin_addr = mreq.imr_multiaddr; 1908 rt = rtlookup((struct sockaddr *)&dst); 1909 if (rt == NULL) { 1910 error = EADDRNOTAVAIL; 1911 crit_exit(); 1912 break; 1913 } 1914 --rt->rt_refcnt; 1915 ifp = rt->rt_ifp; 1916 } else { 1917 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1918 } 1919 1920 /* 1921 * See if we found an interface, and confirm that it 1922 * supports multicast. 1923 */ 1924 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1925 error = EADDRNOTAVAIL; 1926 crit_exit(); 1927 break; 1928 } 1929 /* 1930 * See if the membership already exists or if all the 1931 * membership slots are full. 1932 */ 1933 for (i = 0; i < imo->imo_num_memberships; ++i) { 1934 if (imo->imo_membership[i]->inm_ifp == ifp && 1935 imo->imo_membership[i]->inm_addr.s_addr 1936 == mreq.imr_multiaddr.s_addr) 1937 break; 1938 } 1939 if (i < imo->imo_num_memberships) { 1940 error = EADDRINUSE; 1941 crit_exit(); 1942 break; 1943 } 1944 if (i == IP_MAX_MEMBERSHIPS) { 1945 error = ETOOMANYREFS; 1946 crit_exit(); 1947 break; 1948 } 1949 /* 1950 * Everything looks good; add a new record to the multicast 1951 * address list for the given interface. 1952 */ 1953 if ((imo->imo_membership[i] = 1954 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1955 error = ENOBUFS; 1956 crit_exit(); 1957 break; 1958 } 1959 ++imo->imo_num_memberships; 1960 crit_exit(); 1961 break; 1962 1963 case IP_DROP_MEMBERSHIP: 1964 /* 1965 * Drop a multicast group membership. 1966 * Group must be a valid IP multicast address. 1967 */ 1968 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1969 if (error) 1970 break; 1971 1972 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1973 error = EINVAL; 1974 break; 1975 } 1976 1977 crit_enter(); 1978 /* 1979 * If an interface address was specified, get a pointer 1980 * to its ifnet structure. 1981 */ 1982 if (mreq.imr_interface.s_addr == INADDR_ANY) 1983 ifp = NULL; 1984 else { 1985 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1986 if (ifp == NULL) { 1987 error = EADDRNOTAVAIL; 1988 crit_exit(); 1989 break; 1990 } 1991 } 1992 /* 1993 * Find the membership in the membership array. 1994 */ 1995 for (i = 0; i < imo->imo_num_memberships; ++i) { 1996 if ((ifp == NULL || 1997 imo->imo_membership[i]->inm_ifp == ifp) && 1998 imo->imo_membership[i]->inm_addr.s_addr == 1999 mreq.imr_multiaddr.s_addr) 2000 break; 2001 } 2002 if (i == imo->imo_num_memberships) { 2003 error = EADDRNOTAVAIL; 2004 crit_exit(); 2005 break; 2006 } 2007 /* 2008 * Give up the multicast address record to which the 2009 * membership points. 2010 */ 2011 in_delmulti(imo->imo_membership[i]); 2012 /* 2013 * Remove the gap in the membership array. 2014 */ 2015 for (++i; i < imo->imo_num_memberships; ++i) 2016 imo->imo_membership[i-1] = imo->imo_membership[i]; 2017 --imo->imo_num_memberships; 2018 crit_exit(); 2019 break; 2020 2021 default: 2022 error = EOPNOTSUPP; 2023 break; 2024 } 2025 2026 /* 2027 * If all options have default values, no need to keep the mbuf. 2028 */ 2029 if (imo->imo_multicast_ifp == NULL && 2030 imo->imo_multicast_vif == -1 && 2031 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2032 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2033 imo->imo_num_memberships == 0) { 2034 kfree(*imop, M_IPMOPTS); 2035 *imop = NULL; 2036 } 2037 2038 return (error); 2039 } 2040 2041 /* 2042 * Return the IP multicast options in response to user getsockopt(). 2043 */ 2044 static int 2045 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2046 { 2047 struct in_addr addr; 2048 struct in_ifaddr *ia; 2049 int error, optval; 2050 u_char coptval; 2051 2052 error = 0; 2053 switch (sopt->sopt_name) { 2054 case IP_MULTICAST_VIF: 2055 if (imo != NULL) 2056 optval = imo->imo_multicast_vif; 2057 else 2058 optval = -1; 2059 soopt_from_kbuf(sopt, &optval, sizeof optval); 2060 break; 2061 2062 case IP_MULTICAST_IF: 2063 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2064 addr.s_addr = INADDR_ANY; 2065 else if (imo->imo_multicast_addr.s_addr) { 2066 /* return the value user has set */ 2067 addr = imo->imo_multicast_addr; 2068 } else { 2069 ia = IFP_TO_IA(imo->imo_multicast_ifp); 2070 addr.s_addr = (ia == NULL) ? INADDR_ANY 2071 : IA_SIN(ia)->sin_addr.s_addr; 2072 } 2073 soopt_from_kbuf(sopt, &addr, sizeof addr); 2074 break; 2075 2076 case IP_MULTICAST_TTL: 2077 if (imo == NULL) 2078 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2079 else 2080 optval = coptval = imo->imo_multicast_ttl; 2081 if (sopt->sopt_valsize == 1) 2082 soopt_from_kbuf(sopt, &coptval, 1); 2083 else 2084 soopt_from_kbuf(sopt, &optval, sizeof optval); 2085 break; 2086 2087 case IP_MULTICAST_LOOP: 2088 if (imo == NULL) 2089 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2090 else 2091 optval = coptval = imo->imo_multicast_loop; 2092 if (sopt->sopt_valsize == 1) 2093 soopt_from_kbuf(sopt, &coptval, 1); 2094 else 2095 soopt_from_kbuf(sopt, &optval, sizeof optval); 2096 break; 2097 2098 default: 2099 error = ENOPROTOOPT; 2100 break; 2101 } 2102 return (error); 2103 } 2104 2105 /* 2106 * Discard the IP multicast options. 2107 */ 2108 void 2109 ip_freemoptions(struct ip_moptions *imo) 2110 { 2111 int i; 2112 2113 if (imo != NULL) { 2114 for (i = 0; i < imo->imo_num_memberships; ++i) 2115 in_delmulti(imo->imo_membership[i]); 2116 kfree(imo, M_IPMOPTS); 2117 } 2118 } 2119 2120 /* 2121 * Routine called from ip_output() to loop back a copy of an IP multicast 2122 * packet to the input queue of a specified interface. Note that this 2123 * calls the output routine of the loopback "driver", but with an interface 2124 * pointer that might NOT be a loopback interface -- evil, but easier than 2125 * replicating that code here. 2126 */ 2127 static void 2128 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2129 int hlen) 2130 { 2131 struct ip *ip; 2132 struct mbuf *copym; 2133 2134 copym = m_copypacket(m, MB_DONTWAIT); 2135 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2136 copym = m_pullup(copym, hlen); 2137 if (copym != NULL) { 2138 /* 2139 * if the checksum hasn't been computed, mark it as valid 2140 */ 2141 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2142 in_delayed_cksum(copym); 2143 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2144 copym->m_pkthdr.csum_flags |= 2145 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2146 copym->m_pkthdr.csum_data = 0xffff; 2147 } 2148 /* 2149 * We don't bother to fragment if the IP length is greater 2150 * than the interface's MTU. Can this possibly matter? 2151 */ 2152 ip = mtod(copym, struct ip *); 2153 ip->ip_len = htons(ip->ip_len); 2154 ip->ip_off = htons(ip->ip_off); 2155 ip->ip_sum = 0; 2156 if (ip->ip_vhl == IP_VHL_BORING) { 2157 ip->ip_sum = in_cksum_hdr(ip); 2158 } else { 2159 ip->ip_sum = in_cksum(copym, hlen); 2160 } 2161 /* 2162 * NB: 2163 * It's not clear whether there are any lingering 2164 * reentrancy problems in other areas which might 2165 * be exposed by using ip_input directly (in 2166 * particular, everything which modifies the packet 2167 * in-place). Yet another option is using the 2168 * protosw directly to deliver the looped back 2169 * packet. For the moment, we'll err on the side 2170 * of safety by using if_simloop(). 2171 */ 2172 #if 1 /* XXX */ 2173 if (dst->sin_family != AF_INET) { 2174 kprintf("ip_mloopback: bad address family %d\n", 2175 dst->sin_family); 2176 dst->sin_family = AF_INET; 2177 } 2178 #endif 2179 get_mplock(); /* is if_simloop() mpsafe yet? */ 2180 if_simloop(ifp, copym, dst->sin_family, 0); 2181 rel_mplock(); 2182 } 2183 } 2184