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 int ip_do_rfc6864 = 1; 109 SYSCTL_INT(_net_inet_ip, OID_AUTO, rfc6864, CTLFLAG_RW, &ip_do_rfc6864, 0, 110 "Don't generate IP ID for DF IP datagrams"); 111 112 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 113 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 114 static void ip_mloopback 115 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 116 static int ip_getmoptions 117 (struct sockopt *, struct ip_moptions *); 118 static int ip_pcbopts(int, struct mbuf **, struct mbuf *); 119 static int ip_setmoptions 120 (struct sockopt *, struct ip_moptions **); 121 122 int ip_optcopy(struct ip *, struct ip *); 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 = loif; 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 ASSERT_NETISR_NCPUS(mycpuid); 217 218 m = m0; 219 M_ASSERTPKTHDR(m); 220 221 if (ro == NULL) { 222 ro = &iproute; 223 bzero(ro, sizeof *ro); 224 } else if (ro->ro_rt != NULL && ro->ro_rt->rt_cpuid != mycpuid) { 225 if (flags & IP_DEBUGROUTE) { 226 panic("ip_output: rt rt_cpuid %d accessed on cpu %d\n", 227 ro->ro_rt->rt_cpuid, mycpuid); 228 } 229 230 /* 231 * XXX 232 * If the cached rtentry's owner CPU is not the current CPU, 233 * then don't touch the cached rtentry (remote free is too 234 * expensive in this context); just relocate the route. 235 */ 236 ro = &iproute; 237 bzero(ro, sizeof *ro); 238 } 239 240 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 241 /* Next hop */ 242 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 243 KKASSERT(mtag != NULL); 244 next_hop = m_tag_data(mtag); 245 } 246 247 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 248 struct dn_pkt *dn_pkt; 249 250 /* Extract info from dummynet tag */ 251 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 252 KKASSERT(mtag != NULL); 253 dn_pkt = m_tag_data(mtag); 254 255 /* 256 * The packet was already tagged, so part of the 257 * processing was already done, and we need to go down. 258 * Get the calculated parameters from the tag. 259 */ 260 ifp = dn_pkt->ifp; 261 262 KKASSERT(ro == &iproute); 263 *ro = dn_pkt->ro; /* structure copy */ 264 KKASSERT(ro->ro_rt == NULL || ro->ro_rt->rt_cpuid == mycpuid); 265 266 dst = dn_pkt->dn_dst; 267 if (dst == (struct sockaddr_in *)&(dn_pkt->ro.ro_dst)) { 268 /* If 'dst' points into dummynet tag, adjust it */ 269 dst = (struct sockaddr_in *)&(ro->ro_dst); 270 } 271 272 ip = mtod(m, struct ip *); 273 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 274 if (ro->ro_rt) 275 ia = ifatoia(ro->ro_rt->rt_ifa); 276 goto sendit; 277 } 278 279 if (opt) { 280 len = 0; 281 m = ip_insertoptions(m, opt, &len); 282 if (len != 0) 283 hlen = len; 284 } 285 ip = mtod(m, struct ip *); 286 287 /* 288 * Fill in IP header. 289 */ 290 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) { 291 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 292 ip->ip_off &= IP_DF; 293 if (ip_do_rfc6864 && (ip->ip_off & IP_DF)) 294 ip->ip_id = 0; 295 else 296 ip->ip_id = ip_newid(); 297 ipstat.ips_localout++; 298 } else { 299 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 300 } 301 302 reroute: 303 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst; 304 305 dst = (struct sockaddr_in *)&ro->ro_dst; 306 /* 307 * If there is a cached route, 308 * check that it is to the same destination 309 * and is still up. If not, free it and try again. 310 * The address family should also be checked in case of sharing the 311 * cache with IPv6. 312 */ 313 if (ro->ro_rt && 314 (!(ro->ro_rt->rt_flags & RTF_UP) || 315 dst->sin_family != AF_INET || 316 dst->sin_addr.s_addr != pkt_dst.s_addr)) { 317 rtfree(ro->ro_rt); 318 ro->ro_rt = NULL; 319 } 320 if (ro->ro_rt == NULL) { 321 bzero(dst, sizeof *dst); 322 dst->sin_family = AF_INET; 323 dst->sin_len = sizeof *dst; 324 dst->sin_addr = pkt_dst; 325 } 326 /* 327 * If routing to interface only, 328 * short circuit routing lookup. 329 */ 330 if (flags & IP_ROUTETOIF) { 331 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 332 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) { 333 ipstat.ips_noroute++; 334 error = ENETUNREACH; 335 goto bad; 336 } 337 ifp = ia->ia_ifp; 338 ip->ip_ttl = 1; 339 isbroadcast = in_broadcast(dst->sin_addr, ifp); 340 } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) && 341 imo != NULL && imo->imo_multicast_ifp != NULL) { 342 /* 343 * Bypass the normal routing lookup for multicast 344 * packets if the interface is specified. 345 */ 346 ifp = imo->imo_multicast_ifp; 347 ia = IFP_TO_IA(ifp); 348 isbroadcast = 0; /* fool gcc */ 349 } else { 350 /* 351 * If this is the case, we probably don't want to allocate 352 * a protocol-cloned route since we didn't get one from the 353 * ULP. This lets TCP do its thing, while not burdening 354 * forwarding or ICMP with the overhead of cloning a route. 355 * Of course, we still want to do any cloning requested by 356 * the link layer, as this is probably required in all cases 357 * for correct operation (as it is for ARP). 358 */ 359 if (ro->ro_rt == NULL) 360 rtalloc_ign(ro, RTF_PRCLONING); 361 if (ro->ro_rt == NULL) { 362 ipstat.ips_noroute++; 363 error = EHOSTUNREACH; 364 goto bad; 365 } 366 ia = ifatoia(ro->ro_rt->rt_ifa); 367 ifp = ro->ro_rt->rt_ifp; 368 ro->ro_rt->rt_use++; 369 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 370 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 371 if (ro->ro_rt->rt_flags & RTF_HOST) 372 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 373 else 374 isbroadcast = in_broadcast(dst->sin_addr, ifp); 375 } 376 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) { 377 m->m_flags |= M_MCAST; 378 /* 379 * IP destination address is multicast. Make sure "dst" 380 * still points to the address in "ro". (It may have been 381 * changed to point to a gateway address, above.) 382 */ 383 dst = (struct sockaddr_in *)&ro->ro_dst; 384 /* 385 * See if the caller provided any multicast options 386 */ 387 if (imo != NULL) { 388 ip->ip_ttl = imo->imo_multicast_ttl; 389 if (imo->imo_multicast_vif != -1) { 390 ip->ip_src.s_addr = 391 ip_mcast_src ? 392 ip_mcast_src(imo->imo_multicast_vif) : 393 INADDR_ANY; 394 } 395 } else { 396 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 397 } 398 /* 399 * Confirm that the outgoing interface supports multicast. 400 */ 401 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 402 if (!(ifp->if_flags & IFF_MULTICAST)) { 403 ipstat.ips_noroute++; 404 error = ENETUNREACH; 405 goto bad; 406 } 407 } 408 /* 409 * If source address not specified yet, use address of the 410 * outgoing interface. In case, keep note we did that, so 411 * if the the firewall changes the next-hop causing the 412 * output interface to change, we can fix that. 413 */ 414 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) { 415 /* Interface may have no addresses. */ 416 if (ia != NULL) { 417 ip->ip_src = IA_SIN(ia)->sin_addr; 418 src_was_INADDR_ANY = 1; 419 } 420 } 421 422 if (ip->ip_src.s_addr != INADDR_ANY) { 423 struct in_multi *inm; 424 425 inm = IN_LOOKUP_MULTI(&pkt_dst, ifp); 426 if (inm != NULL && 427 (imo == NULL || imo->imo_multicast_loop)) { 428 /* 429 * If we belong to the destination multicast 430 * group on the outgoing interface, and the 431 * caller did not forbid loopback, loop back 432 * a copy. 433 */ 434 ip_mloopback(ifp, m, dst, hlen); 435 } else { 436 /* 437 * If we are acting as a multicast router, 438 * perform multicast forwarding as if the 439 * packet had just arrived on the interface 440 * to which we are about to send. The 441 * multicast forwarding function recursively 442 * calls this function, using the IP_FORWARDING 443 * flag to prevent infinite recursion. 444 * 445 * Multicasts that are looped back by 446 * ip_mloopback(), above, will be forwarded by 447 * the ip_input() routine, if necessary. 448 */ 449 if (ip_mrouter && !(flags & IP_FORWARDING)) { 450 /* 451 * If rsvp daemon is not running, do 452 * not set ip_moptions. This ensures 453 * that the packet is multicast and 454 * not just sent down one link as 455 * prescribed by rsvpd. 456 */ 457 if (!rsvp_on) 458 imo = NULL; 459 if (ip_mforward) { 460 get_mplock(); 461 if (ip_mforward(ip, ifp, 462 m, imo) != 0) { 463 m_freem(m); 464 rel_mplock(); 465 goto done; 466 } 467 rel_mplock(); 468 } 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 outgoing interface. In case, keep note we did that, 494 * so 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 /* 506 * Look for broadcast address and 507 * verify user is allowed to send 508 * such a packet. 509 */ 510 if (isbroadcast) { 511 if (!(ifp->if_flags & IFF_BROADCAST)) { 512 error = EADDRNOTAVAIL; 513 goto bad; 514 } 515 if (!(flags & IP_ALLOWBROADCAST)) { 516 error = EACCES; 517 goto bad; 518 } 519 /* don't allow broadcast messages to be fragmented */ 520 if (ip->ip_len > ifp->if_mtu) { 521 error = EMSGSIZE; 522 goto bad; 523 } 524 m->m_flags |= M_BCAST; 525 } else { 526 m->m_flags &= ~M_BCAST; 527 } 528 529 sendit: 530 #ifdef IPSEC 531 /* get SP for this packet */ 532 if (so == NULL) 533 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 534 else 535 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 536 537 if (sp == NULL) { 538 ipsecstat.out_inval++; 539 goto bad; 540 } 541 542 error = 0; 543 544 /* check policy */ 545 switch (sp->policy) { 546 case IPSEC_POLICY_DISCARD: 547 /* 548 * This packet is just discarded. 549 */ 550 ipsecstat.out_polvio++; 551 goto bad; 552 553 case IPSEC_POLICY_BYPASS: 554 case IPSEC_POLICY_NONE: 555 case IPSEC_POLICY_TCP: 556 /* no need to do IPsec. */ 557 goto skip_ipsec; 558 559 case IPSEC_POLICY_IPSEC: 560 if (sp->req == NULL) { 561 /* acquire a policy */ 562 error = key_spdacquire(sp); 563 goto bad; 564 } 565 break; 566 567 case IPSEC_POLICY_ENTRUST: 568 default: 569 kprintf("ip_output: Invalid policy found. %d\n", sp->policy); 570 } 571 { 572 struct ipsec_output_state state; 573 bzero(&state, sizeof state); 574 state.m = m; 575 if (flags & IP_ROUTETOIF) { 576 state.ro = &iproute; 577 bzero(&iproute, sizeof iproute); 578 } else 579 state.ro = ro; 580 state.dst = (struct sockaddr *)dst; 581 582 ip->ip_sum = 0; 583 584 /* 585 * XXX 586 * delayed checksums are not currently compatible with IPsec 587 */ 588 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 589 in_delayed_cksum(m); 590 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 591 } 592 593 ip->ip_len = htons(ip->ip_len); 594 ip->ip_off = htons(ip->ip_off); 595 596 error = ipsec4_output(&state, sp, flags); 597 598 m = state.m; 599 if (flags & IP_ROUTETOIF) { 600 /* 601 * if we have tunnel mode SA, we may need to ignore 602 * IP_ROUTETOIF. 603 */ 604 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 605 flags &= ~IP_ROUTETOIF; 606 ro = state.ro; 607 } 608 } else 609 ro = state.ro; 610 dst = (struct sockaddr_in *)state.dst; 611 if (error) { 612 /* mbuf is already reclaimed in ipsec4_output. */ 613 m0 = NULL; 614 switch (error) { 615 case EHOSTUNREACH: 616 case ENETUNREACH: 617 case EMSGSIZE: 618 case ENOBUFS: 619 case ENOMEM: 620 break; 621 default: 622 kprintf("ip4_output (ipsec): error code %d\n", error); 623 /*fall through*/ 624 case ENOENT: 625 /* don't show these error codes to the user */ 626 error = 0; 627 break; 628 } 629 goto bad; 630 } 631 } 632 633 /* be sure to update variables that are affected by ipsec4_output() */ 634 ip = mtod(m, struct ip *); 635 #ifdef _IP_VHL 636 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 637 #else 638 hlen = ip->ip_hl << 2; 639 #endif 640 if (ro->ro_rt == NULL) { 641 if (!(flags & IP_ROUTETOIF)) { 642 kprintf("ip_output: " 643 "can't update route after IPsec processing\n"); 644 error = EHOSTUNREACH; /*XXX*/ 645 goto bad; 646 } 647 } else { 648 ia = ifatoia(ro->ro_rt->rt_ifa); 649 ifp = ro->ro_rt->rt_ifp; 650 } 651 652 /* make it flipped, again. */ 653 ip->ip_len = ntohs(ip->ip_len); 654 ip->ip_off = ntohs(ip->ip_off); 655 skip_ipsec: 656 #endif /*IPSEC*/ 657 #ifdef FAST_IPSEC 658 /* 659 * Check the security policy (SP) for the packet and, if 660 * required, do IPsec-related processing. There are two 661 * cases here; the first time a packet is sent through 662 * it will be untagged and handled by ipsec4_checkpolicy. 663 * If the packet is resubmitted to ip_output (e.g. after 664 * AH, ESP, etc. processing), there will be a tag to bypass 665 * the lookup and related policy checking. 666 */ 667 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 668 crit_enter(); 669 if (mtag != NULL) { 670 tdbi = (struct tdb_ident *)m_tag_data(mtag); 671 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 672 if (sp == NULL) 673 error = -EINVAL; /* force silent drop */ 674 m_tag_delete(m, mtag); 675 } else { 676 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 677 &error, inp); 678 } 679 /* 680 * There are four return cases: 681 * sp != NULL apply IPsec policy 682 * sp == NULL, error == 0 no IPsec handling needed 683 * sp == NULL, error == -EINVAL discard packet w/o error 684 * sp == NULL, error != 0 discard packet, report error 685 */ 686 if (sp != NULL) { 687 /* Loop detection, check if ipsec processing already done */ 688 KASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 689 for (mtag = m_tag_first(m); mtag != NULL; 690 mtag = m_tag_next(m, mtag)) { 691 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 692 continue; 693 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 694 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 695 continue; 696 /* 697 * Check if policy has an SA associated with it. 698 * This can happen when an SP has yet to acquire 699 * an SA; e.g. on first reference. If it occurs, 700 * then we let ipsec4_process_packet do its thing. 701 */ 702 if (sp->req->sav == NULL) 703 break; 704 tdbi = (struct tdb_ident *)m_tag_data(mtag); 705 if (tdbi->spi == sp->req->sav->spi && 706 tdbi->proto == sp->req->sav->sah->saidx.proto && 707 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 708 sizeof(union sockaddr_union)) == 0) { 709 /* 710 * No IPsec processing is needed, free 711 * reference to SP. 712 * 713 * NB: null pointer to avoid free at 714 * done: below. 715 */ 716 KEY_FREESP(&sp), sp = NULL; 717 crit_exit(); 718 goto spd_done; 719 } 720 } 721 722 /* 723 * Do delayed checksums now because we send before 724 * this is done in the normal processing path. 725 */ 726 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 727 in_delayed_cksum(m); 728 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 729 } 730 731 ip->ip_len = htons(ip->ip_len); 732 ip->ip_off = htons(ip->ip_off); 733 734 /* NB: callee frees mbuf */ 735 error = ipsec4_process_packet(m, sp->req, flags, 0); 736 /* 737 * Preserve KAME behaviour: ENOENT can be returned 738 * when an SA acquire is in progress. Don't propagate 739 * this to user-level; it confuses applications. 740 * 741 * XXX this will go away when the SADB is redone. 742 */ 743 if (error == ENOENT) 744 error = 0; 745 crit_exit(); 746 goto done; 747 } else { 748 crit_exit(); 749 750 if (error != 0) { 751 /* 752 * Hack: -EINVAL is used to signal that a packet 753 * should be silently discarded. This is typically 754 * because we asked key management for an SA and 755 * it was delayed (e.g. kicked up to IKE). 756 */ 757 if (error == -EINVAL) 758 error = 0; 759 goto bad; 760 } else { 761 /* No IPsec processing for this packet. */ 762 } 763 #ifdef notyet 764 /* 765 * If deferred crypto processing is needed, check that 766 * the interface supports it. 767 */ 768 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 769 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) { 770 /* notify IPsec to do its own crypto */ 771 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag)); 772 error = EHOSTUNREACH; 773 goto bad; 774 } 775 #endif 776 } 777 spd_done: 778 #endif /* FAST_IPSEC */ 779 780 /* We are already being fwd'd from a firewall. */ 781 if (next_hop != NULL) 782 goto pass; 783 784 /* No pfil hooks */ 785 if (!pfil_has_hooks(&inet_pfil_hook)) { 786 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 787 /* 788 * Strip dummynet tags from stranded packets 789 */ 790 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 791 KKASSERT(mtag != NULL); 792 m_tag_delete(m, mtag); 793 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 794 } 795 goto pass; 796 } 797 798 /* 799 * IpHack's section. 800 * - Xlate: translate packet's addr/port (NAT). 801 * - Firewall: deny/allow/etc. 802 * - Wrap: fake packet's addr/port <unimpl.> 803 * - Encapsulate: put it in another IP and send out. <unimp.> 804 */ 805 806 /* 807 * Run through list of hooks for output packets. 808 */ 809 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT); 810 if (error != 0 || m == NULL) 811 goto done; 812 ip = mtod(m, struct ip *); 813 814 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) { 815 /* 816 * Check dst to make sure it is directly reachable on the 817 * interface we previously thought it was. 818 * If it isn't (which may be likely in some situations) we have 819 * to re-route it (ie, find a route for the next-hop and the 820 * associated interface) and set them here. This is nested 821 * forwarding which in most cases is undesirable, except where 822 * such control is nigh impossible. So we do it here. 823 * And I'm babbling. 824 */ 825 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 826 KKASSERT(mtag != NULL); 827 next_hop = m_tag_data(mtag); 828 829 /* 830 * Try local forwarding first 831 */ 832 if (ip_localforward(m, next_hop, hlen)) 833 goto done; 834 835 /* 836 * Relocate the route based on next_hop. 837 * If the current route is inp's cache, keep it untouched. 838 */ 839 if (ro == &iproute && ro->ro_rt != NULL) { 840 RTFREE(ro->ro_rt); 841 ro->ro_rt = NULL; 842 } 843 ro = &iproute; 844 bzero(ro, sizeof *ro); 845 846 /* 847 * Forwarding to broadcast address is not allowed. 848 * XXX Should we follow IP_ROUTETOIF? 849 */ 850 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF); 851 852 /* We are doing forwarding now */ 853 flags |= IP_FORWARDING; 854 855 goto reroute; 856 } 857 858 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 859 struct dn_pkt *dn_pkt; 860 861 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 862 KKASSERT(mtag != NULL); 863 dn_pkt = m_tag_data(mtag); 864 865 /* 866 * Under certain cases it is not possible to recalculate 867 * 'ro' and 'dst', let alone 'flags', so just save them in 868 * dummynet tag and avoid the possible wrong reculcalation 869 * when we come back to ip_output() again. 870 * 871 * All other parameters have been already used and so they 872 * are not needed anymore. 873 * XXX if the ifp is deleted while a pkt is in dummynet, 874 * we are in trouble! (TODO use ifnet_detach_event) 875 * 876 * We need to copy *ro because for ICMP pkts (and maybe 877 * others) the caller passed a pointer into the stack; 878 * dst might also be a pointer into *ro so it needs to 879 * be updated. 880 */ 881 dn_pkt->ro = *ro; 882 if (ro->ro_rt) 883 ro->ro_rt->rt_refcnt++; 884 if (dst == (struct sockaddr_in *)&ro->ro_dst) { 885 /* 'dst' points into 'ro' */ 886 dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst); 887 } 888 dn_pkt->dn_dst = dst; 889 dn_pkt->flags = flags; 890 891 ip_dn_queue(m); 892 goto done; 893 } 894 895 if (m->m_pkthdr.fw_flags & IPFW_MBUF_CONTINUE) { 896 /* ipfw was disabled/unloaded. */ 897 m_freem(m); 898 goto done; 899 } 900 pass: 901 /* 127/8 must not appear on wire - RFC1122. */ 902 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 903 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 904 if (!(ifp->if_flags & IFF_LOOPBACK)) { 905 ipstat.ips_badaddr++; 906 error = EADDRNOTAVAIL; 907 goto bad; 908 } 909 } 910 if (ip->ip_src.s_addr == INADDR_ANY || 911 IN_MULTICAST(ntohl(ip->ip_src.s_addr))) { 912 ipstat.ips_badaddr++; 913 error = EADDRNOTAVAIL; 914 goto bad; 915 } 916 917 if ((m->m_pkthdr.csum_flags & CSUM_TSO) == 0) { 918 m->m_pkthdr.csum_flags |= CSUM_IP; 919 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; 920 if (sw_csum & CSUM_DELAY_DATA) { 921 in_delayed_cksum(m); 922 sw_csum &= ~CSUM_DELAY_DATA; 923 } 924 m->m_pkthdr.csum_flags &= ifp->if_hwassist; 925 } else { 926 sw_csum = 0; 927 } 928 m->m_pkthdr.csum_iphlen = hlen; 929 930 /* 931 * If small enough for interface, or the interface will take 932 * care of the fragmentation or segmentation for us, can just 933 * send directly. 934 */ 935 if (ip->ip_len <= ifp->if_mtu || 936 ((ifp->if_hwassist & CSUM_FRAGMENT) && !(ip->ip_off & IP_DF)) || 937 (m->m_pkthdr.csum_flags & CSUM_TSO)) { 938 ip->ip_len = htons(ip->ip_len); 939 ip->ip_off = htons(ip->ip_off); 940 ip->ip_sum = 0; 941 if (sw_csum & CSUM_DELAY_IP) { 942 if (ip->ip_vhl == IP_VHL_BORING) 943 ip->ip_sum = in_cksum_hdr(ip); 944 else 945 ip->ip_sum = in_cksum(m, hlen); 946 } 947 948 /* Record statistics for this interface address. */ 949 if (!(flags & IP_FORWARDING) && ia) { 950 IFA_STAT_INC(&ia->ia_ifa, opackets, 1); 951 IFA_STAT_INC(&ia->ia_ifa, obytes, m->m_pkthdr.len); 952 } 953 954 #ifdef IPSEC 955 /* clean ipsec history once it goes out of the node */ 956 ipsec_delaux(m); 957 #endif 958 959 #ifdef MBUF_STRESS_TEST 960 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) { 961 struct mbuf *m1, *m2; 962 int length, tmp; 963 964 tmp = length = m->m_pkthdr.len; 965 966 while ((length -= mbuf_frag_size) >= 1) { 967 m1 = m_split(m, length, M_NOWAIT); 968 if (m1 == NULL) 969 break; 970 m2 = m; 971 while (m2->m_next != NULL) 972 m2 = m2->m_next; 973 m2->m_next = m1; 974 } 975 m->m_pkthdr.len = tmp; 976 } 977 #endif 978 979 #ifdef MPLS 980 if (!mpls_output_process(m, ro->ro_rt)) 981 goto done; 982 #endif 983 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 984 ro->ro_rt); 985 goto done; 986 } 987 988 if (ip->ip_off & IP_DF) { 989 error = EMSGSIZE; 990 /* 991 * This case can happen if the user changed the MTU 992 * of an interface after enabling IP on it. Because 993 * most netifs don't keep track of routes pointing to 994 * them, there is no way for one to update all its 995 * routes when the MTU is changed. 996 */ 997 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) && 998 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && 999 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 1000 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 1001 } 1002 ipstat.ips_cantfrag++; 1003 goto bad; 1004 } 1005 1006 /* 1007 * Too large for interface; fragment if possible. If successful, 1008 * on return, m will point to a list of packets to be sent. 1009 */ 1010 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum); 1011 if (error) 1012 goto bad; 1013 for (; m; m = m0) { 1014 m0 = m->m_nextpkt; 1015 m->m_nextpkt = NULL; 1016 #ifdef IPSEC 1017 /* clean ipsec history once it goes out of the node */ 1018 ipsec_delaux(m); 1019 #endif 1020 if (error == 0) { 1021 /* Record statistics for this interface address. */ 1022 if (ia != NULL) { 1023 IFA_STAT_INC(&ia->ia_ifa, opackets, 1); 1024 IFA_STAT_INC(&ia->ia_ifa, obytes, 1025 m->m_pkthdr.len); 1026 } 1027 #ifdef MPLS 1028 if (!mpls_output_process(m, ro->ro_rt)) 1029 continue; 1030 #endif 1031 error = ifp->if_output(ifp, m, (struct sockaddr *)dst, 1032 ro->ro_rt); 1033 } else { 1034 m_freem(m); 1035 } 1036 } 1037 1038 if (error == 0) 1039 ipstat.ips_fragmented++; 1040 1041 done: 1042 if (ro == &iproute && ro->ro_rt != NULL) { 1043 RTFREE(ro->ro_rt); 1044 ro->ro_rt = NULL; 1045 } 1046 #ifdef IPSEC 1047 if (sp != NULL) { 1048 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 1049 kprintf("DP ip_output call free SP:%p\n", sp)); 1050 key_freesp(sp); 1051 } 1052 #endif 1053 #ifdef FAST_IPSEC 1054 if (sp != NULL) 1055 KEY_FREESP(&sp); 1056 #endif 1057 return (error); 1058 bad: 1059 m_freem(m); 1060 goto done; 1061 } 1062 1063 /* 1064 * Create a chain of fragments which fit the given mtu. m_frag points to the 1065 * mbuf to be fragmented; on return it points to the chain with the fragments. 1066 * Return 0 if no error. If error, m_frag may contain a partially built 1067 * chain of fragments that should be freed by the caller. 1068 * 1069 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 1070 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). 1071 */ 1072 int 1073 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 1074 u_long if_hwassist_flags, int sw_csum) 1075 { 1076 int error = 0; 1077 int hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1078 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 1079 int off; 1080 struct mbuf *m0 = *m_frag; /* the original packet */ 1081 int firstlen; 1082 struct mbuf **mnext; 1083 int nfrags; 1084 1085 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ 1086 ipstat.ips_cantfrag++; 1087 return EMSGSIZE; 1088 } 1089 1090 /* 1091 * Must be able to put at least 8 bytes per fragment. 1092 */ 1093 if (len < 8) 1094 return EMSGSIZE; 1095 1096 /* 1097 * If the interface will not calculate checksums on 1098 * fragmented packets, then do it here. 1099 */ 1100 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) && 1101 !(if_hwassist_flags & CSUM_IP_FRAGS)) { 1102 in_delayed_cksum(m0); 1103 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1104 } 1105 1106 if (len > PAGE_SIZE) { 1107 /* 1108 * Fragment large datagrams such that each segment 1109 * contains a multiple of PAGE_SIZE amount of data, 1110 * plus headers. This enables a receiver to perform 1111 * page-flipping zero-copy optimizations. 1112 * 1113 * XXX When does this help given that sender and receiver 1114 * could have different page sizes, and also mtu could 1115 * be less than the receiver's page size ? 1116 */ 1117 int newlen; 1118 struct mbuf *m; 1119 1120 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 1121 off += m->m_len; 1122 1123 /* 1124 * firstlen (off - hlen) must be aligned on an 1125 * 8-byte boundary 1126 */ 1127 if (off < hlen) 1128 goto smart_frag_failure; 1129 off = ((off - hlen) & ~7) + hlen; 1130 newlen = (~PAGE_MASK) & mtu; 1131 if ((newlen + sizeof(struct ip)) > mtu) { 1132 /* we failed, go back the default */ 1133 smart_frag_failure: 1134 newlen = len; 1135 off = hlen + len; 1136 } 1137 len = newlen; 1138 1139 } else { 1140 off = hlen + len; 1141 } 1142 1143 firstlen = off - hlen; 1144 mnext = &m0->m_nextpkt; /* pointer to next packet */ 1145 1146 /* 1147 * Loop through length of segment after first fragment, 1148 * make new header and copy data of each part and link onto chain. 1149 * Here, m0 is the original packet, m is the fragment being created. 1150 * The fragments are linked off the m_nextpkt of the original 1151 * packet, which after processing serves as the first fragment. 1152 */ 1153 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { 1154 struct ip *mhip; /* ip header on the fragment */ 1155 struct mbuf *m; 1156 int mhlen = sizeof(struct ip); 1157 1158 MGETHDR(m, M_NOWAIT, MT_HEADER); 1159 if (m == NULL) { 1160 error = ENOBUFS; 1161 ipstat.ips_odropped++; 1162 goto done; 1163 } 1164 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; 1165 /* 1166 * In the first mbuf, leave room for the link header, then 1167 * copy the original IP header including options. The payload 1168 * goes into an additional mbuf chain returned by m_copy(). 1169 */ 1170 m->m_data += max_linkhdr; 1171 mhip = mtod(m, struct ip *); 1172 *mhip = *ip; 1173 if (hlen > sizeof(struct ip)) { 1174 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 1175 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 1176 } 1177 m->m_len = mhlen; 1178 /* XXX do we need to add ip->ip_off below ? */ 1179 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; 1180 if (off + len >= ip->ip_len) { /* last fragment */ 1181 len = ip->ip_len - off; 1182 m->m_flags |= M_LASTFRAG; 1183 } else 1184 mhip->ip_off |= IP_MF; 1185 mhip->ip_len = htons((u_short)(len + mhlen)); 1186 m->m_next = m_copy(m0, off, len); 1187 if (m->m_next == NULL) { /* copy failed */ 1188 m_free(m); 1189 error = ENOBUFS; /* ??? */ 1190 ipstat.ips_odropped++; 1191 goto done; 1192 } 1193 m->m_pkthdr.len = mhlen + len; 1194 m->m_pkthdr.rcvif = NULL; 1195 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 1196 m->m_pkthdr.csum_iphlen = mhlen; 1197 mhip->ip_off = htons(mhip->ip_off); 1198 mhip->ip_sum = 0; 1199 if (sw_csum & CSUM_DELAY_IP) 1200 mhip->ip_sum = in_cksum(m, mhlen); 1201 *mnext = m; 1202 mnext = &m->m_nextpkt; 1203 } 1204 ipstat.ips_ofragments += nfrags; 1205 1206 /* set first marker for fragment chain */ 1207 m0->m_flags |= M_FIRSTFRAG | M_FRAG; 1208 m0->m_pkthdr.csum_data = nfrags; 1209 1210 /* 1211 * Update first fragment by trimming what's been copied out 1212 * and updating header. 1213 */ 1214 m_adj(m0, hlen + firstlen - ip->ip_len); 1215 m0->m_pkthdr.len = hlen + firstlen; 1216 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 1217 ip->ip_off |= IP_MF; 1218 ip->ip_off = htons(ip->ip_off); 1219 ip->ip_sum = 0; 1220 if (sw_csum & CSUM_DELAY_IP) 1221 ip->ip_sum = in_cksum(m0, hlen); 1222 1223 done: 1224 *m_frag = m0; 1225 return error; 1226 } 1227 1228 void 1229 in_delayed_cksum(struct mbuf *m) 1230 { 1231 struct ip *ip; 1232 u_short csum, offset; 1233 1234 ip = mtod(m, struct ip *); 1235 offset = IP_VHL_HL(ip->ip_vhl) << 2 ; 1236 csum = in_cksum_skip(m, ip->ip_len, offset); 1237 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 1238 csum = 0xffff; 1239 offset += m->m_pkthdr.csum_data; /* checksum offset */ 1240 1241 if (offset + sizeof(u_short) > m->m_len) { 1242 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n", 1243 m->m_len, offset, ip->ip_p); 1244 /* 1245 * XXX 1246 * this shouldn't happen, but if it does, the 1247 * correct behavior may be to insert the checksum 1248 * in the existing chain instead of rearranging it. 1249 */ 1250 m = m_pullup(m, offset + sizeof(u_short)); 1251 } 1252 *(u_short *)(m->m_data + offset) = csum; 1253 } 1254 1255 /* 1256 * Insert IP options into preformed packet. 1257 * Adjust IP destination as required for IP source routing, 1258 * as indicated by a non-zero in_addr at the start of the options. 1259 * 1260 * XXX This routine assumes that the packet has no options in place. 1261 */ 1262 static struct mbuf * 1263 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1264 { 1265 struct ipoption *p = mtod(opt, struct ipoption *); 1266 struct mbuf *n; 1267 struct ip *ip = mtod(m, struct ip *); 1268 unsigned optlen; 1269 1270 optlen = opt->m_len - sizeof p->ipopt_dst; 1271 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) { 1272 *phlen = 0; 1273 return (m); /* XXX should fail */ 1274 } 1275 if (p->ipopt_dst.s_addr) 1276 ip->ip_dst = p->ipopt_dst; 1277 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 1278 MGETHDR(n, M_NOWAIT, MT_HEADER); 1279 if (n == NULL) { 1280 *phlen = 0; 1281 return (m); 1282 } 1283 n->m_pkthdr.rcvif = NULL; 1284 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 1285 m->m_len -= sizeof(struct ip); 1286 m->m_data += sizeof(struct ip); 1287 n->m_next = m; 1288 m = n; 1289 m->m_len = optlen + sizeof(struct ip); 1290 m->m_data += max_linkhdr; 1291 memcpy(mtod(m, void *), ip, sizeof(struct ip)); 1292 } else { 1293 m->m_data -= optlen; 1294 m->m_len += optlen; 1295 m->m_pkthdr.len += optlen; 1296 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 1297 } 1298 ip = mtod(m, struct ip *); 1299 bcopy(p->ipopt_list, ip + 1, optlen); 1300 *phlen = sizeof(struct ip) + optlen; 1301 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 1302 ip->ip_len += optlen; 1303 return (m); 1304 } 1305 1306 /* 1307 * Copy options from ip to jp, 1308 * omitting those not copied during fragmentation. 1309 */ 1310 int 1311 ip_optcopy(struct ip *ip, struct ip *jp) 1312 { 1313 u_char *cp, *dp; 1314 int opt, optlen, cnt; 1315 1316 cp = (u_char *)(ip + 1); 1317 dp = (u_char *)(jp + 1); 1318 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 1319 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1320 opt = cp[0]; 1321 if (opt == IPOPT_EOL) 1322 break; 1323 if (opt == IPOPT_NOP) { 1324 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1325 *dp++ = IPOPT_NOP; 1326 optlen = 1; 1327 continue; 1328 } 1329 1330 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp, 1331 ("ip_optcopy: malformed ipv4 option")); 1332 optlen = cp[IPOPT_OLEN]; 1333 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt, 1334 ("ip_optcopy: malformed ipv4 option")); 1335 1336 /* bogus lengths should have been caught by ip_dooptions */ 1337 if (optlen > cnt) 1338 optlen = cnt; 1339 if (IPOPT_COPIED(opt)) { 1340 bcopy(cp, dp, optlen); 1341 dp += optlen; 1342 } 1343 } 1344 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1345 *dp++ = IPOPT_EOL; 1346 return (optlen); 1347 } 1348 1349 /* 1350 * IP socket option processing. 1351 */ 1352 void 1353 ip_ctloutput(netmsg_t msg) 1354 { 1355 struct socket *so = msg->base.nm_so; 1356 struct sockopt *sopt = msg->ctloutput.nm_sopt; 1357 struct inpcb *inp = so->so_pcb; 1358 int error, optval; 1359 1360 error = optval = 0; 1361 1362 /* Get socket's owner cpuid hint */ 1363 if (sopt->sopt_level == SOL_SOCKET && 1364 sopt->sopt_dir == SOPT_GET && 1365 sopt->sopt_name == SO_CPUHINT) { 1366 optval = mycpuid; 1367 soopt_from_kbuf(sopt, &optval, sizeof(optval)); 1368 goto done; 1369 } 1370 1371 if (sopt->sopt_level != IPPROTO_IP) { 1372 error = EINVAL; 1373 goto done; 1374 } 1375 1376 switch (sopt->sopt_name) { 1377 case IP_MULTICAST_IF: 1378 case IP_MULTICAST_VIF: 1379 case IP_MULTICAST_TTL: 1380 case IP_MULTICAST_LOOP: 1381 case IP_ADD_MEMBERSHIP: 1382 case IP_DROP_MEMBERSHIP: 1383 /* 1384 * Handle multicast options in netisr0 1385 */ 1386 if (&curthread->td_msgport != netisr_cpuport(0)) { 1387 /* NOTE: so_port MUST NOT be checked in netisr0 */ 1388 msg->lmsg.ms_flags |= MSGF_IGNSOPORT; 1389 lwkt_forwardmsg(netisr_cpuport(0), &msg->lmsg); 1390 return; 1391 } 1392 break; 1393 } 1394 1395 switch (sopt->sopt_dir) { 1396 case SOPT_SET: 1397 switch (sopt->sopt_name) { 1398 case IP_OPTIONS: 1399 #ifdef notyet 1400 case IP_RETOPTS: 1401 #endif 1402 { 1403 struct mbuf *m; 1404 if (sopt->sopt_valsize > MLEN) { 1405 error = EMSGSIZE; 1406 break; 1407 } 1408 MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_HEADER); 1409 if (m == NULL) { 1410 error = ENOBUFS; 1411 break; 1412 } 1413 m->m_len = sopt->sopt_valsize; 1414 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len, 1415 m->m_len); 1416 error = ip_pcbopts(sopt->sopt_name, 1417 &inp->inp_options, m); 1418 goto done; 1419 } 1420 1421 case IP_TOS: 1422 case IP_TTL: 1423 case IP_MINTTL: 1424 case IP_RECVOPTS: 1425 case IP_RECVRETOPTS: 1426 case IP_RECVDSTADDR: 1427 case IP_RECVIF: 1428 case IP_RECVTTL: 1429 case IP_FAITH: 1430 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1431 sizeof optval); 1432 if (error) 1433 break; 1434 switch (sopt->sopt_name) { 1435 case IP_TOS: 1436 inp->inp_ip_tos = optval; 1437 break; 1438 1439 case IP_TTL: 1440 inp->inp_ip_ttl = optval; 1441 break; 1442 case IP_MINTTL: 1443 if (optval >= 0 && optval <= MAXTTL) 1444 inp->inp_ip_minttl = optval; 1445 else 1446 error = EINVAL; 1447 break; 1448 #define OPTSET(bit) \ 1449 if (optval) \ 1450 inp->inp_flags |= bit; \ 1451 else \ 1452 inp->inp_flags &= ~bit; 1453 1454 case IP_RECVOPTS: 1455 OPTSET(INP_RECVOPTS); 1456 break; 1457 1458 case IP_RECVRETOPTS: 1459 OPTSET(INP_RECVRETOPTS); 1460 break; 1461 1462 case IP_RECVDSTADDR: 1463 OPTSET(INP_RECVDSTADDR); 1464 break; 1465 1466 case IP_RECVIF: 1467 OPTSET(INP_RECVIF); 1468 break; 1469 1470 case IP_RECVTTL: 1471 OPTSET(INP_RECVTTL); 1472 break; 1473 1474 case IP_FAITH: 1475 OPTSET(INP_FAITH); 1476 break; 1477 } 1478 break; 1479 #undef OPTSET 1480 1481 case IP_MULTICAST_IF: 1482 case IP_MULTICAST_VIF: 1483 case IP_MULTICAST_TTL: 1484 case IP_MULTICAST_LOOP: 1485 case IP_ADD_MEMBERSHIP: 1486 case IP_DROP_MEMBERSHIP: 1487 error = ip_setmoptions(sopt, &inp->inp_moptions); 1488 break; 1489 1490 case IP_PORTRANGE: 1491 error = soopt_to_kbuf(sopt, &optval, sizeof optval, 1492 sizeof optval); 1493 if (error) 1494 break; 1495 1496 switch (optval) { 1497 case IP_PORTRANGE_DEFAULT: 1498 inp->inp_flags &= ~(INP_LOWPORT); 1499 inp->inp_flags &= ~(INP_HIGHPORT); 1500 break; 1501 1502 case IP_PORTRANGE_HIGH: 1503 inp->inp_flags &= ~(INP_LOWPORT); 1504 inp->inp_flags |= INP_HIGHPORT; 1505 break; 1506 1507 case IP_PORTRANGE_LOW: 1508 inp->inp_flags &= ~(INP_HIGHPORT); 1509 inp->inp_flags |= INP_LOWPORT; 1510 break; 1511 1512 default: 1513 error = EINVAL; 1514 break; 1515 } 1516 break; 1517 1518 #if defined(IPSEC) || defined(FAST_IPSEC) 1519 case IP_IPSEC_POLICY: 1520 { 1521 caddr_t req; 1522 size_t len = 0; 1523 int priv; 1524 struct mbuf *m; 1525 int optname; 1526 1527 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1528 break; 1529 soopt_to_mbuf(sopt, m); 1530 priv = (sopt->sopt_td != NULL && 1531 priv_check(sopt->sopt_td, PRIV_ROOT) != 0) ? 0 : 1; 1532 req = mtod(m, caddr_t); 1533 len = m->m_len; 1534 optname = sopt->sopt_name; 1535 error = ipsec4_set_policy(inp, optname, req, len, priv); 1536 m_freem(m); 1537 break; 1538 } 1539 #endif /*IPSEC*/ 1540 1541 default: 1542 error = ENOPROTOOPT; 1543 break; 1544 } 1545 break; 1546 1547 case SOPT_GET: 1548 switch (sopt->sopt_name) { 1549 case IP_OPTIONS: 1550 case IP_RETOPTS: 1551 if (inp->inp_options) 1552 soopt_from_kbuf(sopt, mtod(inp->inp_options, 1553 char *), 1554 inp->inp_options->m_len); 1555 else 1556 sopt->sopt_valsize = 0; 1557 break; 1558 1559 case IP_TOS: 1560 case IP_TTL: 1561 case IP_MINTTL: 1562 case IP_RECVOPTS: 1563 case IP_RECVRETOPTS: 1564 case IP_RECVDSTADDR: 1565 case IP_RECVTTL: 1566 case IP_RECVIF: 1567 case IP_PORTRANGE: 1568 case IP_FAITH: 1569 switch (sopt->sopt_name) { 1570 1571 case IP_TOS: 1572 optval = inp->inp_ip_tos; 1573 break; 1574 1575 case IP_TTL: 1576 optval = inp->inp_ip_ttl; 1577 break; 1578 case IP_MINTTL: 1579 optval = inp->inp_ip_minttl; 1580 break; 1581 1582 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1583 1584 case IP_RECVOPTS: 1585 optval = OPTBIT(INP_RECVOPTS); 1586 break; 1587 1588 case IP_RECVRETOPTS: 1589 optval = OPTBIT(INP_RECVRETOPTS); 1590 break; 1591 1592 case IP_RECVDSTADDR: 1593 optval = OPTBIT(INP_RECVDSTADDR); 1594 break; 1595 1596 case IP_RECVTTL: 1597 optval = OPTBIT(INP_RECVTTL); 1598 break; 1599 1600 case IP_RECVIF: 1601 optval = OPTBIT(INP_RECVIF); 1602 break; 1603 1604 case IP_PORTRANGE: 1605 if (inp->inp_flags & INP_HIGHPORT) 1606 optval = IP_PORTRANGE_HIGH; 1607 else if (inp->inp_flags & INP_LOWPORT) 1608 optval = IP_PORTRANGE_LOW; 1609 else 1610 optval = 0; 1611 break; 1612 1613 case IP_FAITH: 1614 optval = OPTBIT(INP_FAITH); 1615 break; 1616 } 1617 soopt_from_kbuf(sopt, &optval, sizeof optval); 1618 break; 1619 1620 case IP_MULTICAST_IF: 1621 case IP_MULTICAST_VIF: 1622 case IP_MULTICAST_TTL: 1623 case IP_MULTICAST_LOOP: 1624 case IP_ADD_MEMBERSHIP: 1625 case IP_DROP_MEMBERSHIP: 1626 error = ip_getmoptions(sopt, inp->inp_moptions); 1627 break; 1628 1629 #if defined(IPSEC) || defined(FAST_IPSEC) 1630 case IP_IPSEC_POLICY: 1631 { 1632 struct mbuf *m = NULL; 1633 caddr_t req = NULL; 1634 size_t len = 0; 1635 1636 if (m != NULL) { 1637 req = mtod(m, caddr_t); 1638 len = m->m_len; 1639 } 1640 error = ipsec4_get_policy(so->so_pcb, req, len, &m); 1641 if (error == 0) 1642 error = soopt_from_mbuf(sopt, m); /* XXX */ 1643 if (error == 0) 1644 m_freem(m); 1645 break; 1646 } 1647 #endif /*IPSEC*/ 1648 1649 default: 1650 error = ENOPROTOOPT; 1651 break; 1652 } 1653 break; 1654 } 1655 done: 1656 lwkt_replymsg(&msg->lmsg, error); 1657 } 1658 1659 /* 1660 * Set up IP options in pcb for insertion in output packets. 1661 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1662 * with destination address if source routed. 1663 */ 1664 static int 1665 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1666 { 1667 int cnt, optlen; 1668 u_char *cp; 1669 u_char opt; 1670 1671 /* turn off any old options */ 1672 if (*pcbopt) 1673 m_free(*pcbopt); 1674 *pcbopt = NULL; 1675 if (m == NULL || m->m_len == 0) { 1676 /* 1677 * Only turning off any previous options. 1678 */ 1679 if (m != NULL) 1680 m_free(m); 1681 return (0); 1682 } 1683 1684 if (m->m_len % sizeof(int32_t)) 1685 goto bad; 1686 /* 1687 * IP first-hop destination address will be stored before 1688 * actual options; move other options back 1689 * and clear it when none present. 1690 */ 1691 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1692 goto bad; 1693 cnt = m->m_len; 1694 m->m_len += sizeof(struct in_addr); 1695 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1696 bcopy(mtod(m, caddr_t), cp, cnt); 1697 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1698 1699 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1700 opt = cp[IPOPT_OPTVAL]; 1701 if (opt == IPOPT_EOL) 1702 break; 1703 if (opt == IPOPT_NOP) 1704 optlen = 1; 1705 else { 1706 if (cnt < IPOPT_OLEN + sizeof *cp) 1707 goto bad; 1708 optlen = cp[IPOPT_OLEN]; 1709 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt) 1710 goto bad; 1711 } 1712 switch (opt) { 1713 1714 default: 1715 break; 1716 1717 case IPOPT_LSRR: 1718 case IPOPT_SSRR: 1719 /* 1720 * user process specifies route as: 1721 * ->A->B->C->D 1722 * D must be our final destination (but we can't 1723 * check that since we may not have connected yet). 1724 * A is first hop destination, which doesn't appear in 1725 * actual IP option, but is stored before the options. 1726 */ 1727 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1728 goto bad; 1729 m->m_len -= sizeof(struct in_addr); 1730 cnt -= sizeof(struct in_addr); 1731 optlen -= sizeof(struct in_addr); 1732 cp[IPOPT_OLEN] = optlen; 1733 /* 1734 * Move first hop before start of options. 1735 */ 1736 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1737 sizeof(struct in_addr)); 1738 /* 1739 * Then copy rest of options back 1740 * to close up the deleted entry. 1741 */ 1742 bcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1743 &cp[IPOPT_OFFSET+1], 1744 cnt - (IPOPT_MINOFF - 1)); 1745 break; 1746 } 1747 } 1748 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1749 goto bad; 1750 *pcbopt = m; 1751 return (0); 1752 1753 bad: 1754 m_free(m); 1755 return (EINVAL); 1756 } 1757 1758 /* 1759 * XXX 1760 * The whole multicast option thing needs to be re-thought. 1761 * Several of these options are equally applicable to non-multicast 1762 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1763 * standard option (IP_TTL). 1764 */ 1765 1766 /* 1767 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1768 */ 1769 static struct ifnet * 1770 ip_multicast_if(struct in_addr *a, int *ifindexp) 1771 { 1772 int ifindex; 1773 struct ifnet *ifp; 1774 1775 if (ifindexp) 1776 *ifindexp = 0; 1777 if (ntohl(a->s_addr) >> 24 == 0) { 1778 ifindex = ntohl(a->s_addr) & 0xffffff; 1779 if (ifindex < 0 || if_index < ifindex) 1780 return NULL; 1781 ifp = ifindex2ifnet[ifindex]; 1782 if (ifindexp) 1783 *ifindexp = ifindex; 1784 } else { 1785 ifp = INADDR_TO_IFP(a); 1786 } 1787 return ifp; 1788 } 1789 1790 /* 1791 * Set the IP multicast options in response to user setsockopt(). 1792 */ 1793 static int 1794 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop) 1795 { 1796 int error = 0; 1797 int i; 1798 struct in_addr addr; 1799 struct ip_mreq mreq; 1800 struct ifnet *ifp; 1801 struct ip_moptions *imo = *imop; 1802 int ifindex; 1803 1804 if (imo == NULL) { 1805 /* 1806 * No multicast option buffer attached to the pcb; 1807 * allocate one and initialize to default values. 1808 */ 1809 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK); 1810 1811 imo->imo_multicast_ifp = NULL; 1812 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1813 imo->imo_multicast_vif = -1; 1814 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1815 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1816 imo->imo_num_memberships = 0; 1817 /* Assign imo to imop after all fields are setup */ 1818 cpu_sfence(); 1819 *imop = imo; 1820 } 1821 switch (sopt->sopt_name) { 1822 /* store an index number for the vif you wanna use in the send */ 1823 case IP_MULTICAST_VIF: 1824 if (legal_vif_num == 0) { 1825 error = EOPNOTSUPP; 1826 break; 1827 } 1828 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i); 1829 if (error) 1830 break; 1831 if (!legal_vif_num(i) && (i != -1)) { 1832 error = EINVAL; 1833 break; 1834 } 1835 imo->imo_multicast_vif = i; 1836 break; 1837 1838 case IP_MULTICAST_IF: 1839 /* 1840 * Select the interface for outgoing multicast packets. 1841 */ 1842 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr); 1843 if (error) 1844 break; 1845 1846 /* 1847 * INADDR_ANY is used to remove a previous selection. 1848 * When no interface is selected, a default one is 1849 * chosen every time a multicast packet is sent. 1850 */ 1851 if (addr.s_addr == INADDR_ANY) { 1852 imo->imo_multicast_ifp = NULL; 1853 break; 1854 } 1855 /* 1856 * The selected interface is identified by its local 1857 * IP address. Find the interface and confirm that 1858 * it supports multicasting. 1859 */ 1860 crit_enter(); 1861 ifp = ip_multicast_if(&addr, &ifindex); 1862 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1863 crit_exit(); 1864 error = EADDRNOTAVAIL; 1865 break; 1866 } 1867 imo->imo_multicast_ifp = ifp; 1868 if (ifindex) 1869 imo->imo_multicast_addr = addr; 1870 else 1871 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1872 crit_exit(); 1873 break; 1874 1875 case IP_MULTICAST_TTL: 1876 /* 1877 * Set the IP time-to-live for outgoing multicast packets. 1878 * The original multicast API required a char argument, 1879 * which is inconsistent with the rest of the socket API. 1880 * We allow either a char or an int. 1881 */ 1882 if (sopt->sopt_valsize == 1) { 1883 u_char ttl; 1884 error = soopt_to_kbuf(sopt, &ttl, 1, 1); 1885 if (error) 1886 break; 1887 imo->imo_multicast_ttl = ttl; 1888 } else { 1889 u_int ttl; 1890 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl); 1891 if (error) 1892 break; 1893 if (ttl > 255) 1894 error = EINVAL; 1895 else 1896 imo->imo_multicast_ttl = ttl; 1897 } 1898 break; 1899 1900 case IP_MULTICAST_LOOP: 1901 /* 1902 * Set the loopback flag for outgoing multicast packets. 1903 * Must be zero or one. The original multicast API required a 1904 * char argument, which is inconsistent with the rest 1905 * of the socket API. We allow either a char or an int. 1906 */ 1907 if (sopt->sopt_valsize == 1) { 1908 u_char loop; 1909 1910 error = soopt_to_kbuf(sopt, &loop, 1, 1); 1911 if (error) 1912 break; 1913 imo->imo_multicast_loop = !!loop; 1914 } else { 1915 u_int loop; 1916 1917 error = soopt_to_kbuf(sopt, &loop, sizeof loop, 1918 sizeof loop); 1919 if (error) 1920 break; 1921 imo->imo_multicast_loop = !!loop; 1922 } 1923 break; 1924 1925 case IP_ADD_MEMBERSHIP: 1926 /* 1927 * Add a multicast group membership. 1928 * Group must be a valid IP multicast address. 1929 */ 1930 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 1931 if (error) 1932 break; 1933 1934 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1935 error = EINVAL; 1936 break; 1937 } 1938 crit_enter(); 1939 /* 1940 * If no interface address was provided, use the interface of 1941 * the route to the given multicast address. 1942 */ 1943 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1944 struct sockaddr_in dst; 1945 struct rtentry *rt; 1946 1947 bzero(&dst, sizeof(struct sockaddr_in)); 1948 dst.sin_len = sizeof(struct sockaddr_in); 1949 dst.sin_family = AF_INET; 1950 dst.sin_addr = mreq.imr_multiaddr; 1951 rt = rtlookup((struct sockaddr *)&dst); 1952 if (rt == NULL) { 1953 error = EADDRNOTAVAIL; 1954 crit_exit(); 1955 break; 1956 } 1957 --rt->rt_refcnt; 1958 ifp = rt->rt_ifp; 1959 } else { 1960 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1961 } 1962 1963 /* 1964 * See if we found an interface, and confirm that it 1965 * supports multicast. 1966 */ 1967 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) { 1968 error = EADDRNOTAVAIL; 1969 crit_exit(); 1970 break; 1971 } 1972 /* 1973 * See if the membership already exists or if all the 1974 * membership slots are full. 1975 */ 1976 for (i = 0; i < imo->imo_num_memberships; ++i) { 1977 if (imo->imo_membership[i]->inm_ifp == ifp && 1978 imo->imo_membership[i]->inm_addr.s_addr 1979 == mreq.imr_multiaddr.s_addr) 1980 break; 1981 } 1982 if (i < imo->imo_num_memberships) { 1983 error = EADDRINUSE; 1984 crit_exit(); 1985 break; 1986 } 1987 if (i == IP_MAX_MEMBERSHIPS) { 1988 error = ETOOMANYREFS; 1989 crit_exit(); 1990 break; 1991 } 1992 /* 1993 * Everything looks good; add a new record to the multicast 1994 * address list for the given interface. 1995 */ 1996 if ((imo->imo_membership[i] = 1997 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1998 error = ENOBUFS; 1999 crit_exit(); 2000 break; 2001 } 2002 ++imo->imo_num_memberships; 2003 crit_exit(); 2004 break; 2005 2006 case IP_DROP_MEMBERSHIP: 2007 /* 2008 * Drop a multicast group membership. 2009 * Group must be a valid IP multicast address. 2010 */ 2011 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq); 2012 if (error) 2013 break; 2014 2015 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 2016 error = EINVAL; 2017 break; 2018 } 2019 2020 crit_enter(); 2021 /* 2022 * If an interface address was specified, get a pointer 2023 * to its ifnet structure. 2024 */ 2025 if (mreq.imr_interface.s_addr == INADDR_ANY) 2026 ifp = NULL; 2027 else { 2028 ifp = ip_multicast_if(&mreq.imr_interface, NULL); 2029 if (ifp == NULL) { 2030 error = EADDRNOTAVAIL; 2031 crit_exit(); 2032 break; 2033 } 2034 } 2035 /* 2036 * Find the membership in the membership array. 2037 */ 2038 for (i = 0; i < imo->imo_num_memberships; ++i) { 2039 if ((ifp == NULL || 2040 imo->imo_membership[i]->inm_ifp == ifp) && 2041 imo->imo_membership[i]->inm_addr.s_addr == 2042 mreq.imr_multiaddr.s_addr) 2043 break; 2044 } 2045 if (i == imo->imo_num_memberships) { 2046 error = EADDRNOTAVAIL; 2047 crit_exit(); 2048 break; 2049 } 2050 /* 2051 * Give up the multicast address record to which the 2052 * membership points. 2053 */ 2054 in_delmulti(imo->imo_membership[i]); 2055 /* 2056 * Remove the gap in the membership array. 2057 */ 2058 for (++i; i < imo->imo_num_memberships; ++i) 2059 imo->imo_membership[i-1] = imo->imo_membership[i]; 2060 --imo->imo_num_memberships; 2061 crit_exit(); 2062 break; 2063 2064 default: 2065 error = EOPNOTSUPP; 2066 break; 2067 } 2068 2069 return (error); 2070 } 2071 2072 /* 2073 * Return the IP multicast options in response to user getsockopt(). 2074 */ 2075 static int 2076 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo) 2077 { 2078 struct in_addr addr; 2079 struct in_ifaddr *ia; 2080 int error, optval; 2081 u_char coptval; 2082 2083 error = 0; 2084 switch (sopt->sopt_name) { 2085 case IP_MULTICAST_VIF: 2086 if (imo != NULL) 2087 optval = imo->imo_multicast_vif; 2088 else 2089 optval = -1; 2090 soopt_from_kbuf(sopt, &optval, sizeof optval); 2091 break; 2092 2093 case IP_MULTICAST_IF: 2094 if (imo == NULL || imo->imo_multicast_ifp == NULL) 2095 addr.s_addr = INADDR_ANY; 2096 else if (imo->imo_multicast_addr.s_addr) { 2097 /* return the value user has set */ 2098 addr = imo->imo_multicast_addr; 2099 } else { 2100 ia = IFP_TO_IA(imo->imo_multicast_ifp); 2101 addr.s_addr = (ia == NULL) ? INADDR_ANY 2102 : IA_SIN(ia)->sin_addr.s_addr; 2103 } 2104 soopt_from_kbuf(sopt, &addr, sizeof addr); 2105 break; 2106 2107 case IP_MULTICAST_TTL: 2108 if (imo == NULL) 2109 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 2110 else 2111 optval = coptval = imo->imo_multicast_ttl; 2112 if (sopt->sopt_valsize == 1) 2113 soopt_from_kbuf(sopt, &coptval, 1); 2114 else 2115 soopt_from_kbuf(sopt, &optval, sizeof optval); 2116 break; 2117 2118 case IP_MULTICAST_LOOP: 2119 if (imo == NULL) 2120 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 2121 else 2122 optval = coptval = imo->imo_multicast_loop; 2123 if (sopt->sopt_valsize == 1) 2124 soopt_from_kbuf(sopt, &coptval, 1); 2125 else 2126 soopt_from_kbuf(sopt, &optval, sizeof optval); 2127 break; 2128 2129 default: 2130 error = ENOPROTOOPT; 2131 break; 2132 } 2133 return (error); 2134 } 2135 2136 /* 2137 * Discard the IP multicast options. 2138 */ 2139 void 2140 ip_freemoptions(struct ip_moptions *imo) 2141 { 2142 int i; 2143 2144 if (imo != NULL) { 2145 for (i = 0; i < imo->imo_num_memberships; ++i) 2146 in_delmulti(imo->imo_membership[i]); 2147 kfree(imo, M_IPMOPTS); 2148 } 2149 } 2150 2151 /* 2152 * Routine called from ip_output() to loop back a copy of an IP multicast 2153 * packet to the input queue of a specified interface. Note that this 2154 * calls the output routine of the loopback "driver", but with an interface 2155 * pointer that might NOT be a loopback interface -- evil, but easier than 2156 * replicating that code here. 2157 */ 2158 static void 2159 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 2160 int hlen) 2161 { 2162 struct ip *ip; 2163 struct mbuf *copym; 2164 2165 copym = m_copypacket(m, M_NOWAIT); 2166 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 2167 copym = m_pullup(copym, hlen); 2168 if (copym != NULL) { 2169 /* 2170 * if the checksum hasn't been computed, mark it as valid 2171 */ 2172 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 2173 in_delayed_cksum(copym); 2174 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 2175 copym->m_pkthdr.csum_flags |= 2176 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 2177 copym->m_pkthdr.csum_data = 0xffff; 2178 } 2179 /* 2180 * We don't bother to fragment if the IP length is greater 2181 * than the interface's MTU. Can this possibly matter? 2182 */ 2183 ip = mtod(copym, struct ip *); 2184 ip->ip_len = htons(ip->ip_len); 2185 ip->ip_off = htons(ip->ip_off); 2186 ip->ip_sum = 0; 2187 if (ip->ip_vhl == IP_VHL_BORING) { 2188 ip->ip_sum = in_cksum_hdr(ip); 2189 } else { 2190 ip->ip_sum = in_cksum(copym, hlen); 2191 } 2192 /* 2193 * NB: 2194 * It's not clear whether there are any lingering 2195 * reentrancy problems in other areas which might 2196 * be exposed by using ip_input directly (in 2197 * particular, everything which modifies the packet 2198 * in-place). Yet another option is using the 2199 * protosw directly to deliver the looped back 2200 * packet. For the moment, we'll err on the side 2201 * of safety by using if_simloop(). 2202 */ 2203 #if 1 /* XXX */ 2204 if (dst->sin_family != AF_INET) { 2205 kprintf("ip_mloopback: bad address family %d\n", 2206 dst->sin_family); 2207 dst->sin_family = AF_INET; 2208 } 2209 #endif 2210 if_simloop(ifp, copym, dst->sin_family, 0); 2211 } 2212 } 2213