1 /* $OpenBSD: ip_output.c,v 1.346 2018/03/21 14:42:41 bluhm Exp $ */ 2 /* $NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1988, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 33 */ 34 35 #include "pf.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/mbuf.h> 40 #include <sys/protosw.h> 41 #include <sys/socket.h> 42 #include <sys/socketvar.h> 43 #include <sys/proc.h> 44 #include <sys/kernel.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_enc.h> 49 #include <net/route.h> 50 51 #include <netinet/in.h> 52 #include <netinet/ip.h> 53 #include <netinet/in_pcb.h> 54 #include <netinet/in_var.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/ip_icmp.h> 57 #include <netinet/tcp.h> 58 #include <netinet/udp.h> 59 #include <netinet/tcp_timer.h> 60 #include <netinet/tcp_var.h> 61 #include <netinet/udp_var.h> 62 63 #if NPF > 0 64 #include <net/pfvar.h> 65 #endif 66 67 #ifdef IPSEC 68 #ifdef ENCDEBUG 69 #define DPRINTF(x) do { if (encdebug) printf x ; } while (0) 70 #else 71 #define DPRINTF(x) 72 #endif 73 #endif /* IPSEC */ 74 75 int ip_pcbopts(struct mbuf **, struct mbuf *); 76 int ip_setmoptions(int, struct ip_moptions **, struct mbuf *, u_int); 77 void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); 78 static __inline u_int16_t __attribute__((__unused__)) 79 in_cksum_phdr(u_int32_t, u_int32_t, u_int32_t); 80 void in_delayed_cksum(struct mbuf *); 81 82 #ifdef IPSEC 83 struct tdb * 84 ip_output_ipsec_lookup(struct mbuf *m, int hlen, int *error, struct inpcb *inp, 85 int ipsecflowinfo); 86 int 87 ip_output_ipsec_send(struct tdb *, struct mbuf *, struct route *, int); 88 #endif /* IPSEC */ 89 90 /* 91 * IP output. The packet in mbuf chain m contains a skeletal IP 92 * header (with len, off, ttl, proto, tos, src, dst). 93 * The mbuf chain containing the packet will be freed. 94 * The mbuf opt, if present, will not be freed. 95 */ 96 int 97 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 98 struct ip_moptions *imo, struct inpcb *inp, u_int32_t ipsecflowinfo) 99 { 100 struct ip *ip; 101 struct ifnet *ifp = NULL; 102 struct mbuf *m = m0; 103 int hlen = sizeof (struct ip); 104 int len, error = 0; 105 struct route iproute; 106 struct sockaddr_in *dst; 107 struct tdb *tdb = NULL; 108 u_long mtu; 109 #if defined(MROUTING) 110 int rv; 111 #endif 112 113 NET_ASSERT_LOCKED(); 114 115 #ifdef IPSEC 116 if (inp && (inp->inp_flags & INP_IPV6) != 0) 117 panic("ip_output: IPv6 pcb is passed"); 118 #endif /* IPSEC */ 119 120 #ifdef DIAGNOSTIC 121 if ((m->m_flags & M_PKTHDR) == 0) 122 panic("ip_output no HDR"); 123 #endif 124 if (opt) { 125 m = ip_insertoptions(m, opt, &len); 126 hlen = len; 127 } 128 129 ip = mtod(m, struct ip *); 130 131 /* 132 * Fill in IP header. 133 */ 134 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 135 ip->ip_v = IPVERSION; 136 ip->ip_off &= htons(IP_DF); 137 ip->ip_id = htons(ip_randomid()); 138 ip->ip_hl = hlen >> 2; 139 ipstat_inc(ips_localout); 140 } else { 141 hlen = ip->ip_hl << 2; 142 } 143 144 /* 145 * We should not send traffic to 0/8 say both Stevens and RFCs 146 * 5735 section 3 and 1122 sections 3.2.1.3 and 3.3.6. 147 */ 148 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == 0) { 149 error = ENETUNREACH; 150 goto bad; 151 } 152 153 #if NPF > 0 154 reroute: 155 #endif 156 157 /* 158 * Do a route lookup now in case we need the source address to 159 * do an SPD lookup in IPsec; for most packets, the source address 160 * is set at a higher level protocol. ICMPs and other packets 161 * though (e.g., traceroute) have a source address of zeroes. 162 */ 163 if (ro == NULL) { 164 ro = &iproute; 165 memset(ro, 0, sizeof(*ro)); 166 } 167 168 dst = satosin(&ro->ro_dst); 169 170 /* 171 * If there is a cached route, check that it is to the same 172 * destination and is still up. If not, free it and try again. 173 */ 174 if (!rtisvalid(ro->ro_rt) || 175 dst->sin_addr.s_addr != ip->ip_dst.s_addr || 176 ro->ro_tableid != m->m_pkthdr.ph_rtableid) { 177 rtfree(ro->ro_rt); 178 ro->ro_rt = NULL; 179 } 180 181 if (ro->ro_rt == NULL) { 182 dst->sin_family = AF_INET; 183 dst->sin_len = sizeof(*dst); 184 dst->sin_addr = ip->ip_dst; 185 ro->ro_tableid = m->m_pkthdr.ph_rtableid; 186 } 187 188 if ((IN_MULTICAST(ip->ip_dst.s_addr) || 189 (ip->ip_dst.s_addr == INADDR_BROADCAST)) && 190 imo != NULL && (ifp = if_get(imo->imo_ifidx)) != NULL) { 191 192 mtu = ifp->if_mtu; 193 if (ip->ip_src.s_addr == INADDR_ANY) { 194 struct in_ifaddr *ia; 195 196 IFP_TO_IA(ifp, ia); 197 if (ia != NULL) 198 ip->ip_src = ia->ia_addr.sin_addr; 199 } 200 } else { 201 struct in_ifaddr *ia; 202 203 if (ro->ro_rt == NULL) 204 ro->ro_rt = rtalloc_mpath(&ro->ro_dst, 205 &ip->ip_src.s_addr, ro->ro_tableid); 206 207 if (ro->ro_rt == NULL) { 208 ipstat_inc(ips_noroute); 209 error = EHOSTUNREACH; 210 goto bad; 211 } 212 213 ia = ifatoia(ro->ro_rt->rt_ifa); 214 if (ISSET(ro->ro_rt->rt_flags, RTF_LOCAL)) 215 ifp = if_get(rtable_loindex(m->m_pkthdr.ph_rtableid)); 216 else 217 ifp = if_get(ro->ro_rt->rt_ifidx); 218 /* 219 * We aren't using rtisvalid() here because the UP/DOWN state 220 * machine is broken with some Ethernet drivers like em(4). 221 * As a result we might try to use an invalid cached route 222 * entry while an interface is being detached. 223 */ 224 if (ifp == NULL) { 225 ipstat_inc(ips_noroute); 226 error = EHOSTUNREACH; 227 goto bad; 228 } 229 if ((mtu = ro->ro_rt->rt_mtu) == 0) 230 mtu = ifp->if_mtu; 231 232 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 233 dst = satosin(ro->ro_rt->rt_gateway); 234 235 /* Set the source IP address */ 236 if (ip->ip_src.s_addr == INADDR_ANY && ia) 237 ip->ip_src = ia->ia_addr.sin_addr; 238 } 239 240 #ifdef IPSEC 241 if (ipsec_in_use || inp != NULL) { 242 /* Do we have any pending SAs to apply ? */ 243 tdb = ip_output_ipsec_lookup(m, hlen, &error, inp, 244 ipsecflowinfo); 245 if (error != 0) { 246 /* Should silently drop packet */ 247 if (error == -EINVAL) 248 error = 0; 249 m_freem(m); 250 goto done; 251 } 252 if (tdb != NULL) { 253 /* 254 * If it needs TCP/UDP hardware-checksumming, do the 255 * computation now. 256 */ 257 in_proto_cksum_out(m, NULL); 258 } 259 } 260 #endif /* IPSEC */ 261 262 if (IN_MULTICAST(ip->ip_dst.s_addr) || 263 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 264 265 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 266 M_BCAST : M_MCAST; 267 268 /* 269 * IP destination address is multicast. Make sure "dst" 270 * still points to the address in "ro". (It may have been 271 * changed to point to a gateway address, above.) 272 */ 273 dst = satosin(&ro->ro_dst); 274 275 /* 276 * See if the caller provided any multicast options 277 */ 278 if (imo != NULL) 279 ip->ip_ttl = imo->imo_ttl; 280 else 281 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 282 283 /* 284 * if we don't know the outgoing ifp yet, we can't generate 285 * output 286 */ 287 if (!ifp) { 288 ipstat_inc(ips_noroute); 289 error = EHOSTUNREACH; 290 goto bad; 291 } 292 293 /* 294 * Confirm that the outgoing interface supports multicast, 295 * but only if the packet actually is going out on that 296 * interface (i.e., no IPsec is applied). 297 */ 298 if ((((m->m_flags & M_MCAST) && 299 (ifp->if_flags & IFF_MULTICAST) == 0) || 300 ((m->m_flags & M_BCAST) && 301 (ifp->if_flags & IFF_BROADCAST) == 0)) && (tdb == NULL)) { 302 ipstat_inc(ips_noroute); 303 error = ENETUNREACH; 304 goto bad; 305 } 306 307 /* 308 * If source address not specified yet, use address 309 * of outgoing interface. 310 */ 311 if (ip->ip_src.s_addr == INADDR_ANY) { 312 struct in_ifaddr *ia; 313 314 IFP_TO_IA(ifp, ia); 315 if (ia != NULL) 316 ip->ip_src = ia->ia_addr.sin_addr; 317 } 318 319 if ((imo == NULL || imo->imo_loop) && 320 in_hasmulti(&ip->ip_dst, ifp)) { 321 /* 322 * If we belong to the destination multicast group 323 * on the outgoing interface, and the caller did not 324 * forbid loopback, loop back a copy. 325 * Can't defer TCP/UDP checksumming, do the 326 * computation now. 327 */ 328 in_proto_cksum_out(m, NULL); 329 ip_mloopback(ifp, m, dst); 330 } 331 #ifdef MROUTING 332 else { 333 /* 334 * If we are acting as a multicast router, perform 335 * multicast forwarding as if the packet had just 336 * arrived on the interface to which we are about 337 * to send. The multicast forwarding function 338 * recursively calls this function, using the 339 * IP_FORWARDING flag to prevent infinite recursion. 340 * 341 * Multicasts that are looped back by ip_mloopback(), 342 * above, will be forwarded by the ip_input() routine, 343 * if necessary. 344 */ 345 if (ipmforwarding && ip_mrouter[ifp->if_rdomain] && 346 (flags & IP_FORWARDING) == 0) { 347 KERNEL_LOCK(); 348 rv = ip_mforward(m, ifp); 349 KERNEL_UNLOCK(); 350 if (rv != 0) { 351 m_freem(m); 352 goto done; 353 } 354 } 355 } 356 #endif 357 /* 358 * Multicasts with a time-to-live of zero may be looped- 359 * back, above, but must not be transmitted on a network. 360 * Also, multicasts addressed to the loopback interface 361 * are not sent -- the above call to ip_mloopback() will 362 * loop back a copy if this host actually belongs to the 363 * destination group on the loopback interface. 364 */ 365 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 366 m_freem(m); 367 goto done; 368 } 369 370 goto sendit; 371 } 372 373 /* 374 * Look for broadcast address and verify user is allowed to send 375 * such a packet; if the packet is going in an IPsec tunnel, skip 376 * this check. 377 */ 378 if ((tdb == NULL) && ((dst->sin_addr.s_addr == INADDR_BROADCAST) || 379 (ro && ro->ro_rt && ISSET(ro->ro_rt->rt_flags, RTF_BROADCAST)))) { 380 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 381 error = EADDRNOTAVAIL; 382 goto bad; 383 } 384 if ((flags & IP_ALLOWBROADCAST) == 0) { 385 error = EACCES; 386 goto bad; 387 } 388 389 /* Don't allow broadcast messages to be fragmented */ 390 if (ntohs(ip->ip_len) > ifp->if_mtu) { 391 error = EMSGSIZE; 392 goto bad; 393 } 394 m->m_flags |= M_BCAST; 395 } else 396 m->m_flags &= ~M_BCAST; 397 398 sendit: 399 /* 400 * If we're doing Path MTU discovery, we need to set DF unless 401 * the route's MTU is locked. 402 */ 403 if ((flags & IP_MTUDISC) && ro && ro->ro_rt && 404 (ro->ro_rt->rt_locks & RTV_MTU) == 0) 405 ip->ip_off |= htons(IP_DF); 406 407 #ifdef IPSEC 408 /* 409 * Check if the packet needs encapsulation. 410 */ 411 if (tdb != NULL) { 412 /* Callee frees mbuf */ 413 error = ip_output_ipsec_send(tdb, m, ro, 414 (flags & IP_FORWARDING) ? 1 : 0); 415 goto done; 416 } 417 #endif /* IPSEC */ 418 419 /* 420 * Packet filter 421 */ 422 #if NPF > 0 423 if (pf_test(AF_INET, (flags & IP_FORWARDING) ? PF_FWD : PF_OUT, 424 ifp, &m) != PF_PASS) { 425 error = EACCES; 426 m_freem(m); 427 goto done; 428 } 429 if (m == NULL) 430 goto done; 431 ip = mtod(m, struct ip *); 432 hlen = ip->ip_hl << 2; 433 if ((m->m_pkthdr.pf.flags & (PF_TAG_REROUTE | PF_TAG_GENERATED)) == 434 (PF_TAG_REROUTE | PF_TAG_GENERATED)) 435 /* already rerun the route lookup, go on */ 436 m->m_pkthdr.pf.flags &= ~(PF_TAG_GENERATED | PF_TAG_REROUTE); 437 else if (m->m_pkthdr.pf.flags & PF_TAG_REROUTE) { 438 /* tag as generated to skip over pf_test on rerun */ 439 m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 440 ro = NULL; 441 if_put(ifp); /* drop reference since target changed */ 442 ifp = NULL; 443 goto reroute; 444 } 445 #endif 446 in_proto_cksum_out(m, ifp); 447 448 #ifdef IPSEC 449 if (ipsec_in_use && (flags & IP_FORWARDING) && (ipforwarding == 2) && 450 (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) == NULL)) { 451 error = EHOSTUNREACH; 452 m_freem(m); 453 goto done; 454 } 455 #endif 456 457 /* 458 * If small enough for interface, can just send directly. 459 */ 460 if (ntohs(ip->ip_len) <= mtu) { 461 ip->ip_sum = 0; 462 if ((ifp->if_capabilities & IFCAP_CSUM_IPv4) && 463 (ifp->if_bridgeport == NULL)) 464 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 465 else { 466 ipstat_inc(ips_outswcsum); 467 ip->ip_sum = in_cksum(m, hlen); 468 } 469 470 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 471 goto done; 472 } 473 474 /* 475 * Too large for interface; fragment if possible. 476 * Must be able to put at least 8 bytes per fragment. 477 */ 478 if (ip->ip_off & htons(IP_DF)) { 479 #ifdef IPSEC 480 if (ip_mtudisc) 481 ipsec_adjust_mtu(m, ifp->if_mtu); 482 #endif 483 error = EMSGSIZE; 484 /* 485 * This case can happen if the user changed the MTU 486 * of an interface after enabling IP on it. Because 487 * most netifs don't keep track of routes pointing to 488 * them, there is no way for one to update all its 489 * routes when the MTU is changed. 490 */ 491 if (rtisvalid(ro->ro_rt) && 492 ISSET(ro->ro_rt->rt_flags, RTF_HOST) && 493 !(ro->ro_rt->rt_locks & RTV_MTU) && 494 (ro->ro_rt->rt_mtu > ifp->if_mtu)) { 495 ro->ro_rt->rt_mtu = ifp->if_mtu; 496 } 497 ipstat_inc(ips_cantfrag); 498 goto bad; 499 } 500 501 error = ip_fragment(m, ifp, mtu); 502 if (error) { 503 m = m0 = NULL; 504 goto bad; 505 } 506 507 for (; m; m = m0) { 508 m0 = m->m_nextpkt; 509 m->m_nextpkt = 0; 510 if (error == 0) 511 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 512 else 513 m_freem(m); 514 } 515 516 if (error == 0) 517 ipstat_inc(ips_fragmented); 518 519 done: 520 if (ro == &iproute && ro->ro_rt) 521 rtfree(ro->ro_rt); 522 if_put(ifp); 523 return (error); 524 bad: 525 m_freem(m0); 526 goto done; 527 } 528 529 #ifdef IPSEC 530 struct tdb * 531 ip_output_ipsec_lookup(struct mbuf *m, int hlen, int *error, struct inpcb *inp, 532 int ipsecflowinfo) 533 { 534 struct m_tag *mtag; 535 struct tdb_ident *tdbi; 536 struct tdb *tdb; 537 538 /* Do we have any pending SAs to apply ? */ 539 tdb = ipsp_spd_lookup(m, AF_INET, hlen, error, IPSP_DIRECTION_OUT, 540 NULL, inp, ipsecflowinfo); 541 if (tdb == NULL) 542 return NULL; 543 /* Loop detection */ 544 for (mtag = m_tag_first(m); mtag != NULL; mtag = m_tag_next(m, mtag)) { 545 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE) 546 continue; 547 tdbi = (struct tdb_ident *)(mtag + 1); 548 if (tdbi->spi == tdb->tdb_spi && 549 tdbi->proto == tdb->tdb_sproto && 550 tdbi->rdomain == tdb->tdb_rdomain && 551 !memcmp(&tdbi->dst, &tdb->tdb_dst, 552 sizeof(union sockaddr_union))) { 553 /* no IPsec needed */ 554 return NULL; 555 } 556 } 557 return tdb; 558 } 559 560 int 561 ip_output_ipsec_send(struct tdb *tdb, struct mbuf *m, struct route *ro, int fwd) 562 { 563 #if NPF > 0 564 struct ifnet *encif; 565 #endif 566 struct ip *ip; 567 568 #if NPF > 0 569 /* 570 * Packet filter 571 */ 572 if ((encif = enc_getif(tdb->tdb_rdomain, tdb->tdb_tap)) == NULL || 573 pf_test(AF_INET, fwd ? PF_FWD : PF_OUT, encif, &m) != PF_PASS) { 574 m_freem(m); 575 return EACCES; 576 } 577 if (m == NULL) 578 return 0; 579 /* 580 * PF_TAG_REROUTE handling or not... 581 * Packet is entering IPsec so the routing is 582 * already overruled by the IPsec policy. 583 * Until now the change was not reconsidered. 584 * What's the behaviour? 585 */ 586 in_proto_cksum_out(m, encif); 587 #endif 588 589 /* Check if we are allowed to fragment */ 590 ip = mtod(m, struct ip *); 591 if (ip_mtudisc && (ip->ip_off & htons(IP_DF)) && tdb->tdb_mtu && 592 ntohs(ip->ip_len) > tdb->tdb_mtu && 593 tdb->tdb_mtutimeout > time_second) { 594 struct rtentry *rt = NULL; 595 int rt_mtucloned = 0; 596 int transportmode = 0; 597 598 transportmode = (tdb->tdb_dst.sa.sa_family == AF_INET) && 599 (tdb->tdb_dst.sin.sin_addr.s_addr == ip->ip_dst.s_addr); 600 601 /* Find a host route to store the mtu in */ 602 if (ro != NULL) 603 rt = ro->ro_rt; 604 /* but don't add a PMTU route for transport mode SAs */ 605 if (transportmode) 606 rt = NULL; 607 else if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0) { 608 rt = icmp_mtudisc_clone(ip->ip_dst, 609 m->m_pkthdr.ph_rtableid); 610 rt_mtucloned = 1; 611 } 612 DPRINTF(("%s: spi %08x mtu %d rt %p cloned %d\n", __func__, 613 ntohl(tdb->tdb_spi), tdb->tdb_mtu, rt, rt_mtucloned)); 614 if (rt != NULL) { 615 rt->rt_mtu = tdb->tdb_mtu; 616 if (ro && ro->ro_rt != NULL) { 617 rtfree(ro->ro_rt); 618 ro->ro_rt = rtalloc(&ro->ro_dst, RT_RESOLVE, 619 m->m_pkthdr.ph_rtableid); 620 } 621 if (rt_mtucloned) 622 rtfree(rt); 623 } 624 ipsec_adjust_mtu(m, tdb->tdb_mtu); 625 m_freem(m); 626 return EMSGSIZE; 627 } 628 629 /* 630 * Clear these -- they'll be set in the recursive invocation 631 * as needed. 632 */ 633 m->m_flags &= ~(M_MCAST | M_BCAST); 634 635 /* Callee frees mbuf */ 636 return ipsp_process_packet(m, tdb, AF_INET, 0); 637 } 638 #endif /* IPSEC */ 639 640 int 641 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 642 { 643 struct ip *ip, *mhip; 644 struct mbuf *m0; 645 int len, hlen, off; 646 int mhlen, firstlen; 647 struct mbuf **mnext; 648 int fragments = 0; 649 int error = 0; 650 651 ip = mtod(m, struct ip *); 652 hlen = ip->ip_hl << 2; 653 654 len = (mtu - hlen) &~ 7; 655 if (len < 8) { 656 m_freem(m); 657 return (EMSGSIZE); 658 } 659 660 /* 661 * If we are doing fragmentation, we can't defer TCP/UDP 662 * checksumming; compute the checksum and clear the flag. 663 */ 664 in_proto_cksum_out(m, NULL); 665 firstlen = len; 666 mnext = &m->m_nextpkt; 667 668 /* 669 * Loop through length of segment after first fragment, 670 * make new header and copy data of each part and link onto chain. 671 */ 672 m0 = m; 673 mhlen = sizeof (struct ip); 674 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 675 MGETHDR(m, M_DONTWAIT, MT_HEADER); 676 if (m == NULL) { 677 ipstat_inc(ips_odropped); 678 error = ENOBUFS; 679 goto sendorfree; 680 } 681 *mnext = m; 682 mnext = &m->m_nextpkt; 683 m->m_data += max_linkhdr; 684 mhip = mtod(m, struct ip *); 685 *mhip = *ip; 686 /* we must inherit MCAST/BCAST flags, routing table and prio */ 687 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 688 m->m_pkthdr.ph_rtableid = m0->m_pkthdr.ph_rtableid; 689 m->m_pkthdr.pf.prio = m0->m_pkthdr.pf.prio; 690 if (hlen > sizeof (struct ip)) { 691 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 692 mhip->ip_hl = mhlen >> 2; 693 } 694 m->m_len = mhlen; 695 mhip->ip_off = ((off - hlen) >> 3) + 696 (ntohs(ip->ip_off) & ~IP_MF); 697 if (ip->ip_off & htons(IP_MF)) 698 mhip->ip_off |= IP_MF; 699 if (off + len >= ntohs(ip->ip_len)) 700 len = ntohs(ip->ip_len) - off; 701 else 702 mhip->ip_off |= IP_MF; 703 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 704 m->m_next = m_copym(m0, off, len, M_NOWAIT); 705 if (m->m_next == 0) { 706 ipstat_inc(ips_odropped); 707 error = ENOBUFS; 708 goto sendorfree; 709 } 710 m->m_pkthdr.len = mhlen + len; 711 m->m_pkthdr.ph_ifidx = 0; 712 mhip->ip_off = htons((u_int16_t)mhip->ip_off); 713 mhip->ip_sum = 0; 714 if ((ifp != NULL) && 715 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 716 (ifp->if_bridgeport == NULL)) 717 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 718 else { 719 ipstat_inc(ips_outswcsum); 720 mhip->ip_sum = in_cksum(m, mhlen); 721 } 722 ipstat_inc(ips_ofragments); 723 fragments++; 724 } 725 /* 726 * Update first fragment by trimming what's been copied out 727 * and updating header, then send each fragment (in order). 728 */ 729 m = m0; 730 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 731 m->m_pkthdr.len = hlen + firstlen; 732 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 733 ip->ip_off |= htons(IP_MF); 734 ip->ip_sum = 0; 735 if ((ifp != NULL) && 736 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 737 (ifp->if_bridgeport == NULL)) 738 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 739 else { 740 ipstat_inc(ips_outswcsum); 741 ip->ip_sum = in_cksum(m, hlen); 742 } 743 sendorfree: 744 if (error) { 745 for (m = m0; m; m = m0) { 746 m0 = m->m_nextpkt; 747 m->m_nextpkt = NULL; 748 m_freem(m); 749 } 750 } 751 752 return (error); 753 } 754 755 /* 756 * Insert IP options into preformed packet. 757 * Adjust IP destination as required for IP source routing, 758 * as indicated by a non-zero in_addr at the start of the options. 759 */ 760 struct mbuf * 761 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 762 { 763 struct ipoption *p = mtod(opt, struct ipoption *); 764 struct mbuf *n; 765 struct ip *ip = mtod(m, struct ip *); 766 unsigned int optlen; 767 768 optlen = opt->m_len - sizeof(p->ipopt_dst); 769 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 770 return (m); /* XXX should fail */ 771 if (p->ipopt_dst.s_addr) 772 ip->ip_dst = p->ipopt_dst; 773 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 774 MGETHDR(n, M_DONTWAIT, MT_HEADER); 775 if (n == NULL) 776 return (m); 777 M_MOVE_HDR(n, m); 778 n->m_pkthdr.len += optlen; 779 m->m_len -= sizeof(struct ip); 780 m->m_data += sizeof(struct ip); 781 n->m_next = m; 782 m = n; 783 m->m_len = optlen + sizeof(struct ip); 784 m->m_data += max_linkhdr; 785 memcpy(mtod(m, caddr_t), ip, sizeof(struct ip)); 786 } else { 787 m->m_data -= optlen; 788 m->m_len += optlen; 789 m->m_pkthdr.len += optlen; 790 memmove(mtod(m, caddr_t), (caddr_t)ip, sizeof(struct ip)); 791 } 792 ip = mtod(m, struct ip *); 793 memcpy(ip + 1, p->ipopt_list, optlen); 794 *phlen = sizeof(struct ip) + optlen; 795 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 796 return (m); 797 } 798 799 /* 800 * Copy options from ip to jp, 801 * omitting those not copied during fragmentation. 802 */ 803 int 804 ip_optcopy(struct ip *ip, struct ip *jp) 805 { 806 u_char *cp, *dp; 807 int opt, optlen, cnt; 808 809 cp = (u_char *)(ip + 1); 810 dp = (u_char *)(jp + 1); 811 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 812 for (; cnt > 0; cnt -= optlen, cp += optlen) { 813 opt = cp[0]; 814 if (opt == IPOPT_EOL) 815 break; 816 if (opt == IPOPT_NOP) { 817 /* Preserve for IP mcast tunnel's LSRR alignment. */ 818 *dp++ = IPOPT_NOP; 819 optlen = 1; 820 continue; 821 } 822 #ifdef DIAGNOSTIC 823 if (cnt < IPOPT_OLEN + sizeof(*cp)) 824 panic("malformed IPv4 option passed to ip_optcopy"); 825 #endif 826 optlen = cp[IPOPT_OLEN]; 827 #ifdef DIAGNOSTIC 828 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 829 panic("malformed IPv4 option passed to ip_optcopy"); 830 #endif 831 /* bogus lengths should have been caught by ip_dooptions */ 832 if (optlen > cnt) 833 optlen = cnt; 834 if (IPOPT_COPIED(opt)) { 835 memcpy(dp, cp, optlen); 836 dp += optlen; 837 } 838 } 839 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 840 *dp++ = IPOPT_EOL; 841 return (optlen); 842 } 843 844 /* 845 * IP socket option processing. 846 */ 847 int 848 ip_ctloutput(int op, struct socket *so, int level, int optname, 849 struct mbuf *m) 850 { 851 struct inpcb *inp = sotoinpcb(so); 852 int optval = 0; 853 struct proc *p = curproc; /* XXX */ 854 int error = 0; 855 u_int rtid = 0; 856 857 if (level != IPPROTO_IP) { 858 error = EINVAL; 859 } else switch (op) { 860 case PRCO_SETOPT: 861 switch (optname) { 862 case IP_OPTIONS: 863 return (ip_pcbopts(&inp->inp_options, m)); 864 865 case IP_TOS: 866 case IP_TTL: 867 case IP_MINTTL: 868 case IP_RECVOPTS: 869 case IP_RECVRETOPTS: 870 case IP_RECVDSTADDR: 871 case IP_RECVIF: 872 case IP_RECVTTL: 873 case IP_RECVDSTPORT: 874 case IP_RECVRTABLE: 875 case IP_IPSECFLOWINFO: 876 if (m == NULL || m->m_len != sizeof(int)) 877 error = EINVAL; 878 else { 879 optval = *mtod(m, int *); 880 switch (optname) { 881 882 case IP_TOS: 883 inp->inp_ip.ip_tos = optval; 884 break; 885 886 case IP_TTL: 887 if (optval > 0 && optval <= MAXTTL) 888 inp->inp_ip.ip_ttl = optval; 889 else if (optval == -1) 890 inp->inp_ip.ip_ttl = ip_defttl; 891 else 892 error = EINVAL; 893 break; 894 895 case IP_MINTTL: 896 if (optval >= 0 && optval <= MAXTTL) 897 inp->inp_ip_minttl = optval; 898 else 899 error = EINVAL; 900 break; 901 #define OPTSET(bit) \ 902 if (optval) \ 903 inp->inp_flags |= bit; \ 904 else \ 905 inp->inp_flags &= ~bit; 906 907 case IP_RECVOPTS: 908 OPTSET(INP_RECVOPTS); 909 break; 910 911 case IP_RECVRETOPTS: 912 OPTSET(INP_RECVRETOPTS); 913 break; 914 915 case IP_RECVDSTADDR: 916 OPTSET(INP_RECVDSTADDR); 917 break; 918 case IP_RECVIF: 919 OPTSET(INP_RECVIF); 920 break; 921 case IP_RECVTTL: 922 OPTSET(INP_RECVTTL); 923 break; 924 case IP_RECVDSTPORT: 925 OPTSET(INP_RECVDSTPORT); 926 break; 927 case IP_RECVRTABLE: 928 OPTSET(INP_RECVRTABLE); 929 break; 930 case IP_IPSECFLOWINFO: 931 OPTSET(INP_IPSECFLOWINFO); 932 break; 933 } 934 } 935 break; 936 #undef OPTSET 937 938 case IP_MULTICAST_IF: 939 case IP_MULTICAST_TTL: 940 case IP_MULTICAST_LOOP: 941 case IP_ADD_MEMBERSHIP: 942 case IP_DROP_MEMBERSHIP: 943 error = ip_setmoptions(optname, &inp->inp_moptions, m, 944 inp->inp_rtableid); 945 break; 946 947 case IP_PORTRANGE: 948 if (m == NULL || m->m_len != sizeof(int)) 949 error = EINVAL; 950 else { 951 optval = *mtod(m, int *); 952 953 switch (optval) { 954 955 case IP_PORTRANGE_DEFAULT: 956 inp->inp_flags &= ~(INP_LOWPORT); 957 inp->inp_flags &= ~(INP_HIGHPORT); 958 break; 959 960 case IP_PORTRANGE_HIGH: 961 inp->inp_flags &= ~(INP_LOWPORT); 962 inp->inp_flags |= INP_HIGHPORT; 963 break; 964 965 case IP_PORTRANGE_LOW: 966 inp->inp_flags &= ~(INP_HIGHPORT); 967 inp->inp_flags |= INP_LOWPORT; 968 break; 969 970 default: 971 972 error = EINVAL; 973 break; 974 } 975 } 976 break; 977 case IP_AUTH_LEVEL: 978 case IP_ESP_TRANS_LEVEL: 979 case IP_ESP_NETWORK_LEVEL: 980 case IP_IPCOMP_LEVEL: 981 #ifndef IPSEC 982 error = EOPNOTSUPP; 983 #else 984 if (m == NULL || m->m_len != sizeof(int)) { 985 error = EINVAL; 986 break; 987 } 988 optval = *mtod(m, int *); 989 990 if (optval < IPSEC_LEVEL_BYPASS || 991 optval > IPSEC_LEVEL_UNIQUE) { 992 error = EINVAL; 993 break; 994 } 995 996 switch (optname) { 997 case IP_AUTH_LEVEL: 998 if (optval < IPSEC_AUTH_LEVEL_DEFAULT && 999 suser(p)) { 1000 error = EACCES; 1001 break; 1002 } 1003 inp->inp_seclevel[SL_AUTH] = optval; 1004 break; 1005 1006 case IP_ESP_TRANS_LEVEL: 1007 if (optval < IPSEC_ESP_TRANS_LEVEL_DEFAULT && 1008 suser(p)) { 1009 error = EACCES; 1010 break; 1011 } 1012 inp->inp_seclevel[SL_ESP_TRANS] = optval; 1013 break; 1014 1015 case IP_ESP_NETWORK_LEVEL: 1016 if (optval < IPSEC_ESP_NETWORK_LEVEL_DEFAULT && 1017 suser(p)) { 1018 error = EACCES; 1019 break; 1020 } 1021 inp->inp_seclevel[SL_ESP_NETWORK] = optval; 1022 break; 1023 case IP_IPCOMP_LEVEL: 1024 if (optval < IPSEC_IPCOMP_LEVEL_DEFAULT && 1025 suser(p)) { 1026 error = EACCES; 1027 break; 1028 } 1029 inp->inp_seclevel[SL_IPCOMP] = optval; 1030 break; 1031 } 1032 #endif 1033 break; 1034 1035 case IP_IPSEC_LOCAL_ID: 1036 case IP_IPSEC_REMOTE_ID: 1037 error = EOPNOTSUPP; 1038 break; 1039 case SO_RTABLE: 1040 if (m == NULL || m->m_len < sizeof(u_int)) { 1041 error = EINVAL; 1042 break; 1043 } 1044 rtid = *mtod(m, u_int *); 1045 if (inp->inp_rtableid == rtid) 1046 break; 1047 /* needs privileges to switch when already set */ 1048 if (p->p_p->ps_rtableid != rtid && 1049 p->p_p->ps_rtableid != 0 && 1050 (error = suser(p)) != 0) 1051 break; 1052 /* table must exist */ 1053 if (!rtable_exists(rtid)) { 1054 error = EINVAL; 1055 break; 1056 } 1057 if (inp->inp_lport) { 1058 error = EBUSY; 1059 break; 1060 } 1061 inp->inp_rtableid = rtid; 1062 in_pcbrehash(inp); 1063 break; 1064 case IP_PIPEX: 1065 if (m != NULL && m->m_len == sizeof(int)) 1066 inp->inp_pipex = *mtod(m, int *); 1067 else 1068 error = EINVAL; 1069 break; 1070 1071 default: 1072 error = ENOPROTOOPT; 1073 break; 1074 } 1075 break; 1076 1077 case PRCO_GETOPT: 1078 switch (optname) { 1079 case IP_OPTIONS: 1080 case IP_RETOPTS: 1081 if (inp->inp_options) { 1082 m->m_len = inp->inp_options->m_len; 1083 memcpy(mtod(m, caddr_t), 1084 mtod(inp->inp_options, caddr_t), m->m_len); 1085 } else 1086 m->m_len = 0; 1087 break; 1088 1089 case IP_TOS: 1090 case IP_TTL: 1091 case IP_MINTTL: 1092 case IP_RECVOPTS: 1093 case IP_RECVRETOPTS: 1094 case IP_RECVDSTADDR: 1095 case IP_RECVIF: 1096 case IP_RECVTTL: 1097 case IP_RECVDSTPORT: 1098 case IP_RECVRTABLE: 1099 case IP_IPSECFLOWINFO: 1100 case IP_IPDEFTTL: 1101 m->m_len = sizeof(int); 1102 switch (optname) { 1103 1104 case IP_TOS: 1105 optval = inp->inp_ip.ip_tos; 1106 break; 1107 1108 case IP_TTL: 1109 optval = inp->inp_ip.ip_ttl; 1110 break; 1111 1112 case IP_MINTTL: 1113 optval = inp->inp_ip_minttl; 1114 break; 1115 1116 case IP_IPDEFTTL: 1117 optval = ip_defttl; 1118 break; 1119 1120 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1121 1122 case IP_RECVOPTS: 1123 optval = OPTBIT(INP_RECVOPTS); 1124 break; 1125 1126 case IP_RECVRETOPTS: 1127 optval = OPTBIT(INP_RECVRETOPTS); 1128 break; 1129 1130 case IP_RECVDSTADDR: 1131 optval = OPTBIT(INP_RECVDSTADDR); 1132 break; 1133 case IP_RECVIF: 1134 optval = OPTBIT(INP_RECVIF); 1135 break; 1136 case IP_RECVTTL: 1137 optval = OPTBIT(INP_RECVTTL); 1138 break; 1139 case IP_RECVDSTPORT: 1140 optval = OPTBIT(INP_RECVDSTPORT); 1141 break; 1142 case IP_RECVRTABLE: 1143 optval = OPTBIT(INP_RECVRTABLE); 1144 break; 1145 case IP_IPSECFLOWINFO: 1146 optval = OPTBIT(INP_IPSECFLOWINFO); 1147 break; 1148 } 1149 *mtod(m, int *) = optval; 1150 break; 1151 1152 case IP_MULTICAST_IF: 1153 case IP_MULTICAST_TTL: 1154 case IP_MULTICAST_LOOP: 1155 case IP_ADD_MEMBERSHIP: 1156 case IP_DROP_MEMBERSHIP: 1157 error = ip_getmoptions(optname, inp->inp_moptions, m); 1158 break; 1159 1160 case IP_PORTRANGE: 1161 m->m_len = sizeof(int); 1162 1163 if (inp->inp_flags & INP_HIGHPORT) 1164 optval = IP_PORTRANGE_HIGH; 1165 else if (inp->inp_flags & INP_LOWPORT) 1166 optval = IP_PORTRANGE_LOW; 1167 else 1168 optval = 0; 1169 1170 *mtod(m, int *) = optval; 1171 break; 1172 1173 case IP_AUTH_LEVEL: 1174 case IP_ESP_TRANS_LEVEL: 1175 case IP_ESP_NETWORK_LEVEL: 1176 case IP_IPCOMP_LEVEL: 1177 #ifndef IPSEC 1178 m->m_len = sizeof(int); 1179 *mtod(m, int *) = IPSEC_LEVEL_NONE; 1180 #else 1181 m->m_len = sizeof(int); 1182 switch (optname) { 1183 case IP_AUTH_LEVEL: 1184 optval = inp->inp_seclevel[SL_AUTH]; 1185 break; 1186 1187 case IP_ESP_TRANS_LEVEL: 1188 optval = inp->inp_seclevel[SL_ESP_TRANS]; 1189 break; 1190 1191 case IP_ESP_NETWORK_LEVEL: 1192 optval = inp->inp_seclevel[SL_ESP_NETWORK]; 1193 break; 1194 case IP_IPCOMP_LEVEL: 1195 optval = inp->inp_seclevel[SL_IPCOMP]; 1196 break; 1197 } 1198 *mtod(m, int *) = optval; 1199 #endif 1200 break; 1201 case IP_IPSEC_LOCAL_ID: 1202 case IP_IPSEC_REMOTE_ID: 1203 error = EOPNOTSUPP; 1204 break; 1205 case SO_RTABLE: 1206 m->m_len = sizeof(u_int); 1207 *mtod(m, u_int *) = inp->inp_rtableid; 1208 break; 1209 case IP_PIPEX: 1210 m->m_len = sizeof(int); 1211 *mtod(m, int *) = inp->inp_pipex; 1212 break; 1213 default: 1214 error = ENOPROTOOPT; 1215 break; 1216 } 1217 break; 1218 } 1219 return (error); 1220 } 1221 1222 /* 1223 * Set up IP options in pcb for insertion in output packets. 1224 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1225 * with destination address if source routed. 1226 */ 1227 int 1228 ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) 1229 { 1230 int cnt, optlen; 1231 u_char *cp; 1232 u_char opt; 1233 1234 /* turn off any old options */ 1235 m_free(*pcbopt); 1236 *pcbopt = 0; 1237 if (m == NULL || m->m_len == 0) { 1238 /* 1239 * Only turning off any previous options. 1240 */ 1241 return (0); 1242 } 1243 1244 if (m->m_len % sizeof(int32_t)) 1245 return (EINVAL); 1246 1247 /* 1248 * IP first-hop destination address will be stored before 1249 * actual options; move other options back 1250 * and clear it when none present. 1251 */ 1252 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1253 return (EINVAL); 1254 cnt = m->m_len; 1255 m->m_len += sizeof(struct in_addr); 1256 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1257 memmove((caddr_t)cp, mtod(m, caddr_t), (unsigned)cnt); 1258 memset(mtod(m, caddr_t), 0, sizeof(struct in_addr)); 1259 1260 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1261 opt = cp[IPOPT_OPTVAL]; 1262 if (opt == IPOPT_EOL) 1263 break; 1264 if (opt == IPOPT_NOP) 1265 optlen = 1; 1266 else { 1267 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1268 return (EINVAL); 1269 optlen = cp[IPOPT_OLEN]; 1270 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1271 return (EINVAL); 1272 } 1273 switch (opt) { 1274 1275 default: 1276 break; 1277 1278 case IPOPT_LSRR: 1279 case IPOPT_SSRR: 1280 /* 1281 * user process specifies route as: 1282 * ->A->B->C->D 1283 * D must be our final destination (but we can't 1284 * check that since we may not have connected yet). 1285 * A is first hop destination, which doesn't appear in 1286 * actual IP option, but is stored before the options. 1287 */ 1288 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1289 return (EINVAL); 1290 m->m_len -= sizeof(struct in_addr); 1291 cnt -= sizeof(struct in_addr); 1292 optlen -= sizeof(struct in_addr); 1293 cp[IPOPT_OLEN] = optlen; 1294 /* 1295 * Move first hop before start of options. 1296 */ 1297 memcpy(mtod(m, caddr_t), &cp[IPOPT_OFFSET+1], 1298 sizeof(struct in_addr)); 1299 /* 1300 * Then copy rest of options back 1301 * to close up the deleted entry. 1302 */ 1303 memmove((caddr_t)&cp[IPOPT_OFFSET+1], 1304 (caddr_t)(&cp[IPOPT_OFFSET+1] + 1305 sizeof(struct in_addr)), 1306 (unsigned)cnt - (IPOPT_OFFSET+1)); 1307 break; 1308 } 1309 } 1310 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1311 return (EINVAL); 1312 *pcbopt = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1313 if (*pcbopt == NULL) 1314 return (ENOBUFS); 1315 1316 return (0); 1317 } 1318 1319 /* 1320 * Set the IP multicast options in response to user setsockopt(). 1321 */ 1322 int 1323 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m, 1324 u_int rtableid) 1325 { 1326 struct in_addr addr; 1327 struct in_ifaddr *ia; 1328 struct ip_mreq *mreq; 1329 struct ifnet *ifp = NULL; 1330 struct ip_moptions *imo = *imop; 1331 struct in_multi **immp; 1332 struct rtentry *rt; 1333 struct sockaddr_in sin; 1334 int i, error = 0; 1335 u_char loop; 1336 1337 if (imo == NULL) { 1338 /* 1339 * No multicast option buffer attached to the pcb; 1340 * allocate one and initialize to default values. 1341 */ 1342 imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK|M_ZERO); 1343 immp = (struct in_multi **)malloc( 1344 (sizeof(*immp) * IP_MIN_MEMBERSHIPS), M_IPMOPTS, 1345 M_WAITOK|M_ZERO); 1346 *imop = imo; 1347 imo->imo_ifidx = 0; 1348 imo->imo_ttl = IP_DEFAULT_MULTICAST_TTL; 1349 imo->imo_loop = IP_DEFAULT_MULTICAST_LOOP; 1350 imo->imo_num_memberships = 0; 1351 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; 1352 imo->imo_membership = immp; 1353 } 1354 1355 switch (optname) { 1356 1357 case IP_MULTICAST_IF: 1358 /* 1359 * Select the interface for outgoing multicast packets. 1360 */ 1361 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1362 error = EINVAL; 1363 break; 1364 } 1365 addr = *(mtod(m, struct in_addr *)); 1366 /* 1367 * INADDR_ANY is used to remove a previous selection. 1368 * When no interface is selected, a default one is 1369 * chosen every time a multicast packet is sent. 1370 */ 1371 if (addr.s_addr == INADDR_ANY) { 1372 imo->imo_ifidx = 0; 1373 break; 1374 } 1375 /* 1376 * The selected interface is identified by its local 1377 * IP address. Find the interface and confirm that 1378 * it supports multicasting. 1379 */ 1380 memset(&sin, 0, sizeof(sin)); 1381 sin.sin_len = sizeof(sin); 1382 sin.sin_family = AF_INET; 1383 sin.sin_addr = addr; 1384 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1385 if (ia == NULL || 1386 (ia->ia_ifp->if_flags & IFF_MULTICAST) == 0) { 1387 error = EADDRNOTAVAIL; 1388 break; 1389 } 1390 imo->imo_ifidx = ia->ia_ifp->if_index; 1391 break; 1392 1393 case IP_MULTICAST_TTL: 1394 /* 1395 * Set the IP time-to-live for outgoing multicast packets. 1396 */ 1397 if (m == NULL || m->m_len != 1) { 1398 error = EINVAL; 1399 break; 1400 } 1401 imo->imo_ttl = *(mtod(m, u_char *)); 1402 break; 1403 1404 case IP_MULTICAST_LOOP: 1405 /* 1406 * Set the loopback flag for outgoing multicast packets. 1407 * Must be zero or one. 1408 */ 1409 if (m == NULL || m->m_len != 1 || 1410 (loop = *(mtod(m, u_char *))) > 1) { 1411 error = EINVAL; 1412 break; 1413 } 1414 imo->imo_loop = loop; 1415 break; 1416 1417 case IP_ADD_MEMBERSHIP: 1418 /* 1419 * Add a multicast group membership. 1420 * Group must be a valid IP multicast address. 1421 */ 1422 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1423 error = EINVAL; 1424 break; 1425 } 1426 mreq = mtod(m, struct ip_mreq *); 1427 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1428 error = EINVAL; 1429 break; 1430 } 1431 /* 1432 * If no interface address was provided, use the interface of 1433 * the route to the given multicast address. 1434 */ 1435 if (mreq->imr_interface.s_addr == INADDR_ANY) { 1436 memset(&sin, 0, sizeof(sin)); 1437 sin.sin_len = sizeof(sin); 1438 sin.sin_family = AF_INET; 1439 sin.sin_addr = mreq->imr_multiaddr; 1440 rt = rtalloc(sintosa(&sin), RT_RESOLVE, rtableid); 1441 if (!rtisvalid(rt)) { 1442 rtfree(rt); 1443 error = EADDRNOTAVAIL; 1444 break; 1445 } 1446 } else { 1447 memset(&sin, 0, sizeof(sin)); 1448 sin.sin_len = sizeof(sin); 1449 sin.sin_family = AF_INET; 1450 sin.sin_addr = mreq->imr_interface; 1451 rt = rtalloc(sintosa(&sin), 0, rtableid); 1452 if (!rtisvalid(rt) || !ISSET(rt->rt_flags, RTF_LOCAL)) { 1453 rtfree(rt); 1454 error = EADDRNOTAVAIL; 1455 break; 1456 } 1457 } 1458 ifp = if_get(rt->rt_ifidx); 1459 rtfree(rt); 1460 1461 /* 1462 * See if we found an interface, and confirm that it 1463 * supports multicast. 1464 */ 1465 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1466 error = EADDRNOTAVAIL; 1467 if_put(ifp); 1468 break; 1469 } 1470 /* 1471 * See if the membership already exists or if all the 1472 * membership slots are full. 1473 */ 1474 for (i = 0; i < imo->imo_num_memberships; ++i) { 1475 if (imo->imo_membership[i]->inm_ifidx 1476 == ifp->if_index && 1477 imo->imo_membership[i]->inm_addr.s_addr 1478 == mreq->imr_multiaddr.s_addr) 1479 break; 1480 } 1481 if (i < imo->imo_num_memberships) { 1482 error = EADDRINUSE; 1483 if_put(ifp); 1484 break; 1485 } 1486 if (imo->imo_num_memberships == imo->imo_max_memberships) { 1487 struct in_multi **nmships, **omships; 1488 size_t newmax; 1489 /* 1490 * Resize the vector to next power-of-two minus 1. If the 1491 * size would exceed the maximum then we know we've really 1492 * run out of entries. Otherwise, we reallocate the vector. 1493 */ 1494 nmships = NULL; 1495 omships = imo->imo_membership; 1496 newmax = ((imo->imo_max_memberships + 1) * 2) - 1; 1497 if (newmax <= IP_MAX_MEMBERSHIPS) { 1498 nmships = (struct in_multi **)mallocarray( 1499 newmax, sizeof(*nmships), M_IPMOPTS, 1500 M_NOWAIT|M_ZERO); 1501 if (nmships != NULL) { 1502 memcpy(nmships, omships, 1503 sizeof(*omships) * 1504 imo->imo_max_memberships); 1505 free(omships, M_IPMOPTS, 1506 sizeof(*omships) * 1507 imo->imo_max_memberships); 1508 imo->imo_membership = nmships; 1509 imo->imo_max_memberships = newmax; 1510 } 1511 } 1512 if (nmships == NULL) { 1513 error = ENOBUFS; 1514 if_put(ifp); 1515 break; 1516 } 1517 } 1518 /* 1519 * Everything looks good; add a new record to the multicast 1520 * address list for the given interface. 1521 */ 1522 if ((imo->imo_membership[i] = 1523 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1524 error = ENOBUFS; 1525 if_put(ifp); 1526 break; 1527 } 1528 ++imo->imo_num_memberships; 1529 if_put(ifp); 1530 break; 1531 1532 case IP_DROP_MEMBERSHIP: 1533 /* 1534 * Drop a multicast group membership. 1535 * Group must be a valid IP multicast address. 1536 */ 1537 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1538 error = EINVAL; 1539 break; 1540 } 1541 mreq = mtod(m, struct ip_mreq *); 1542 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1543 error = EINVAL; 1544 break; 1545 } 1546 /* 1547 * If an interface address was specified, get a pointer 1548 * to its ifnet structure. 1549 */ 1550 if (mreq->imr_interface.s_addr == INADDR_ANY) 1551 ifp = NULL; 1552 else { 1553 memset(&sin, 0, sizeof(sin)); 1554 sin.sin_len = sizeof(sin); 1555 sin.sin_family = AF_INET; 1556 sin.sin_addr = mreq->imr_interface; 1557 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1558 if (ia == NULL) { 1559 error = EADDRNOTAVAIL; 1560 break; 1561 } 1562 ifp = ia->ia_ifp; 1563 } 1564 /* 1565 * Find the membership in the membership array. 1566 */ 1567 for (i = 0; i < imo->imo_num_memberships; ++i) { 1568 if ((ifp == NULL || 1569 imo->imo_membership[i]->inm_ifidx == 1570 ifp->if_index) && 1571 imo->imo_membership[i]->inm_addr.s_addr == 1572 mreq->imr_multiaddr.s_addr) 1573 break; 1574 } 1575 if (i == imo->imo_num_memberships) { 1576 error = EADDRNOTAVAIL; 1577 break; 1578 } 1579 /* 1580 * Give up the multicast address record to which the 1581 * membership points. 1582 */ 1583 in_delmulti(imo->imo_membership[i]); 1584 /* 1585 * Remove the gap in the membership array. 1586 */ 1587 for (++i; i < imo->imo_num_memberships; ++i) 1588 imo->imo_membership[i-1] = imo->imo_membership[i]; 1589 --imo->imo_num_memberships; 1590 break; 1591 1592 default: 1593 error = EOPNOTSUPP; 1594 break; 1595 } 1596 1597 /* 1598 * If all options have default values, no need to keep the data. 1599 */ 1600 if (imo->imo_ifidx == 0 && 1601 imo->imo_ttl == IP_DEFAULT_MULTICAST_TTL && 1602 imo->imo_loop == IP_DEFAULT_MULTICAST_LOOP && 1603 imo->imo_num_memberships == 0) { 1604 free(imo->imo_membership , M_IPMOPTS, 0); 1605 free(*imop, M_IPMOPTS, sizeof(**imop)); 1606 *imop = NULL; 1607 } 1608 1609 return (error); 1610 } 1611 1612 /* 1613 * Return the IP multicast options in response to user getsockopt(). 1614 */ 1615 int 1616 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf *m) 1617 { 1618 u_char *ttl; 1619 u_char *loop; 1620 struct in_addr *addr; 1621 struct in_ifaddr *ia; 1622 struct ifnet *ifp; 1623 1624 switch (optname) { 1625 1626 case IP_MULTICAST_IF: 1627 addr = mtod(m, struct in_addr *); 1628 m->m_len = sizeof(struct in_addr); 1629 if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL) 1630 addr->s_addr = INADDR_ANY; 1631 else { 1632 IFP_TO_IA(ifp, ia); 1633 if_put(ifp); 1634 addr->s_addr = (ia == NULL) ? INADDR_ANY 1635 : ia->ia_addr.sin_addr.s_addr; 1636 } 1637 return (0); 1638 1639 case IP_MULTICAST_TTL: 1640 ttl = mtod(m, u_char *); 1641 m->m_len = 1; 1642 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1643 : imo->imo_ttl; 1644 return (0); 1645 1646 case IP_MULTICAST_LOOP: 1647 loop = mtod(m, u_char *); 1648 m->m_len = 1; 1649 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1650 : imo->imo_loop; 1651 return (0); 1652 1653 default: 1654 return (EOPNOTSUPP); 1655 } 1656 } 1657 1658 /* 1659 * Discard the IP multicast options. 1660 */ 1661 void 1662 ip_freemoptions(struct ip_moptions *imo) 1663 { 1664 int i; 1665 1666 if (imo != NULL) { 1667 for (i = 0; i < imo->imo_num_memberships; ++i) 1668 in_delmulti(imo->imo_membership[i]); 1669 free(imo->imo_membership, M_IPMOPTS, 0); 1670 free(imo, M_IPMOPTS, sizeof(*imo)); 1671 } 1672 } 1673 1674 /* 1675 * Routine called from ip_output() to loop back a copy of an IP multicast 1676 * packet to the input queue of a specified interface. 1677 */ 1678 void 1679 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1680 { 1681 struct ip *ip; 1682 struct mbuf *copym; 1683 1684 copym = m_dup_pkt(m, max_linkhdr, M_DONTWAIT); 1685 if (copym != NULL) { 1686 /* 1687 * We don't bother to fragment if the IP length is greater 1688 * than the interface's MTU. Can this possibly matter? 1689 */ 1690 ip = mtod(copym, struct ip *); 1691 ip->ip_sum = 0; 1692 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1693 if_input_local(ifp, copym, dst->sin_family); 1694 } 1695 } 1696 1697 /* 1698 * Compute significant parts of the IPv4 checksum pseudo-header 1699 * for use in a delayed TCP/UDP checksum calculation. 1700 */ 1701 static __inline u_int16_t __attribute__((__unused__)) 1702 in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) 1703 { 1704 u_int32_t sum; 1705 1706 sum = lenproto + 1707 (u_int16_t)(src >> 16) + 1708 (u_int16_t)(src /*& 0xffff*/) + 1709 (u_int16_t)(dst >> 16) + 1710 (u_int16_t)(dst /*& 0xffff*/); 1711 1712 sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); 1713 1714 if (sum > 0xffff) 1715 sum -= 0xffff; 1716 1717 return (sum); 1718 } 1719 1720 /* 1721 * Process a delayed payload checksum calculation. 1722 */ 1723 void 1724 in_delayed_cksum(struct mbuf *m) 1725 { 1726 struct ip *ip; 1727 u_int16_t csum, offset; 1728 1729 ip = mtod(m, struct ip *); 1730 offset = ip->ip_hl << 2; 1731 csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset); 1732 if (csum == 0 && ip->ip_p == IPPROTO_UDP) 1733 csum = 0xffff; 1734 1735 switch (ip->ip_p) { 1736 case IPPROTO_TCP: 1737 offset += offsetof(struct tcphdr, th_sum); 1738 break; 1739 1740 case IPPROTO_UDP: 1741 offset += offsetof(struct udphdr, uh_sum); 1742 break; 1743 1744 case IPPROTO_ICMP: 1745 offset += offsetof(struct icmp, icmp_cksum); 1746 break; 1747 1748 default: 1749 return; 1750 } 1751 1752 if ((offset + sizeof(u_int16_t)) > m->m_len) 1753 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1754 else 1755 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1756 } 1757 1758 void 1759 in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp) 1760 { 1761 struct ip *ip = mtod(m, struct ip *); 1762 1763 /* some hw and in_delayed_cksum need the pseudo header cksum */ 1764 if (m->m_pkthdr.csum_flags & 1765 (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT|M_ICMP_CSUM_OUT)) { 1766 u_int16_t csum = 0, offset; 1767 1768 offset = ip->ip_hl << 2; 1769 if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) 1770 csum = in_cksum_phdr(ip->ip_src.s_addr, 1771 ip->ip_dst.s_addr, htonl(ntohs(ip->ip_len) - 1772 offset + ip->ip_p)); 1773 if (ip->ip_p == IPPROTO_TCP) 1774 offset += offsetof(struct tcphdr, th_sum); 1775 else if (ip->ip_p == IPPROTO_UDP) 1776 offset += offsetof(struct udphdr, uh_sum); 1777 else if (ip->ip_p == IPPROTO_ICMP) 1778 offset += offsetof(struct icmp, icmp_cksum); 1779 if ((offset + sizeof(u_int16_t)) > m->m_len) 1780 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1781 else 1782 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1783 } 1784 1785 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) { 1786 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || 1787 ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { 1788 tcpstat_inc(tcps_outswcsum); 1789 in_delayed_cksum(m); 1790 m->m_pkthdr.csum_flags &= ~M_TCP_CSUM_OUT; /* Clear */ 1791 } 1792 } else if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) { 1793 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || 1794 ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { 1795 udpstat_inc(udps_outswcsum); 1796 in_delayed_cksum(m); 1797 m->m_pkthdr.csum_flags &= ~M_UDP_CSUM_OUT; /* Clear */ 1798 } 1799 } else if (m->m_pkthdr.csum_flags & M_ICMP_CSUM_OUT) { 1800 in_delayed_cksum(m); 1801 m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */ 1802 } 1803 } 1804