1 /* $OpenBSD: ip_output.c,v 1.348 2018/08/28 15:15:02 mpi 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 int error; 568 569 #if NPF > 0 570 /* 571 * Packet filter 572 */ 573 if ((encif = enc_getif(tdb->tdb_rdomain, tdb->tdb_tap)) == NULL || 574 pf_test(AF_INET, fwd ? PF_FWD : PF_OUT, encif, &m) != PF_PASS) { 575 m_freem(m); 576 return EACCES; 577 } 578 if (m == NULL) 579 return 0; 580 /* 581 * PF_TAG_REROUTE handling or not... 582 * Packet is entering IPsec so the routing is 583 * already overruled by the IPsec policy. 584 * Until now the change was not reconsidered. 585 * What's the behaviour? 586 */ 587 in_proto_cksum_out(m, encif); 588 #endif 589 590 /* Check if we are allowed to fragment */ 591 ip = mtod(m, struct ip *); 592 if (ip_mtudisc && (ip->ip_off & htons(IP_DF)) && tdb->tdb_mtu && 593 ntohs(ip->ip_len) > tdb->tdb_mtu && 594 tdb->tdb_mtutimeout > time_second) { 595 struct rtentry *rt = NULL; 596 int rt_mtucloned = 0; 597 int transportmode = 0; 598 599 transportmode = (tdb->tdb_dst.sa.sa_family == AF_INET) && 600 (tdb->tdb_dst.sin.sin_addr.s_addr == ip->ip_dst.s_addr); 601 602 /* Find a host route to store the mtu in */ 603 if (ro != NULL) 604 rt = ro->ro_rt; 605 /* but don't add a PMTU route for transport mode SAs */ 606 if (transportmode) 607 rt = NULL; 608 else if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0) { 609 rt = icmp_mtudisc_clone(ip->ip_dst, 610 m->m_pkthdr.ph_rtableid); 611 rt_mtucloned = 1; 612 } 613 DPRINTF(("%s: spi %08x mtu %d rt %p cloned %d\n", __func__, 614 ntohl(tdb->tdb_spi), tdb->tdb_mtu, rt, rt_mtucloned)); 615 if (rt != NULL) { 616 rt->rt_mtu = tdb->tdb_mtu; 617 if (ro && ro->ro_rt != NULL) { 618 rtfree(ro->ro_rt); 619 ro->ro_rt = rtalloc(&ro->ro_dst, RT_RESOLVE, 620 m->m_pkthdr.ph_rtableid); 621 } 622 if (rt_mtucloned) 623 rtfree(rt); 624 } 625 ipsec_adjust_mtu(m, tdb->tdb_mtu); 626 m_freem(m); 627 return EMSGSIZE; 628 } 629 630 /* 631 * Clear these -- they'll be set in the recursive invocation 632 * as needed. 633 */ 634 m->m_flags &= ~(M_MCAST | M_BCAST); 635 636 /* Callee frees mbuf */ 637 error = ipsp_process_packet(m, tdb, AF_INET, 0); 638 if (error) { 639 ipsecstat_inc(ipsec_odrops); 640 tdb->tdb_odrops++; 641 } 642 return error; 643 } 644 #endif /* IPSEC */ 645 646 int 647 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 648 { 649 struct ip *ip, *mhip; 650 struct mbuf *m0; 651 int len, hlen, off; 652 int mhlen, firstlen; 653 struct mbuf **mnext; 654 int fragments = 0; 655 int error = 0; 656 657 ip = mtod(m, struct ip *); 658 hlen = ip->ip_hl << 2; 659 660 len = (mtu - hlen) &~ 7; 661 if (len < 8) { 662 m_freem(m); 663 return (EMSGSIZE); 664 } 665 666 /* 667 * If we are doing fragmentation, we can't defer TCP/UDP 668 * checksumming; compute the checksum and clear the flag. 669 */ 670 in_proto_cksum_out(m, NULL); 671 firstlen = len; 672 mnext = &m->m_nextpkt; 673 674 /* 675 * Loop through length of segment after first fragment, 676 * make new header and copy data of each part and link onto chain. 677 */ 678 m0 = m; 679 mhlen = sizeof (struct ip); 680 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 681 MGETHDR(m, M_DONTWAIT, MT_HEADER); 682 if (m == NULL) { 683 ipstat_inc(ips_odropped); 684 error = ENOBUFS; 685 goto sendorfree; 686 } 687 *mnext = m; 688 mnext = &m->m_nextpkt; 689 m->m_data += max_linkhdr; 690 mhip = mtod(m, struct ip *); 691 *mhip = *ip; 692 /* we must inherit MCAST/BCAST flags, routing table and prio */ 693 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 694 m->m_pkthdr.ph_rtableid = m0->m_pkthdr.ph_rtableid; 695 m->m_pkthdr.pf.prio = m0->m_pkthdr.pf.prio; 696 if (hlen > sizeof (struct ip)) { 697 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 698 mhip->ip_hl = mhlen >> 2; 699 } 700 m->m_len = mhlen; 701 mhip->ip_off = ((off - hlen) >> 3) + 702 (ntohs(ip->ip_off) & ~IP_MF); 703 if (ip->ip_off & htons(IP_MF)) 704 mhip->ip_off |= IP_MF; 705 if (off + len >= ntohs(ip->ip_len)) 706 len = ntohs(ip->ip_len) - off; 707 else 708 mhip->ip_off |= IP_MF; 709 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 710 m->m_next = m_copym(m0, off, len, M_NOWAIT); 711 if (m->m_next == 0) { 712 ipstat_inc(ips_odropped); 713 error = ENOBUFS; 714 goto sendorfree; 715 } 716 m->m_pkthdr.len = mhlen + len; 717 m->m_pkthdr.ph_ifidx = 0; 718 mhip->ip_off = htons((u_int16_t)mhip->ip_off); 719 mhip->ip_sum = 0; 720 if ((ifp != NULL) && 721 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 722 (ifp->if_bridgeport == NULL)) 723 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 724 else { 725 ipstat_inc(ips_outswcsum); 726 mhip->ip_sum = in_cksum(m, mhlen); 727 } 728 ipstat_inc(ips_ofragments); 729 fragments++; 730 } 731 /* 732 * Update first fragment by trimming what's been copied out 733 * and updating header, then send each fragment (in order). 734 */ 735 m = m0; 736 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 737 m->m_pkthdr.len = hlen + firstlen; 738 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 739 ip->ip_off |= htons(IP_MF); 740 ip->ip_sum = 0; 741 if ((ifp != NULL) && 742 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 743 (ifp->if_bridgeport == NULL)) 744 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 745 else { 746 ipstat_inc(ips_outswcsum); 747 ip->ip_sum = in_cksum(m, hlen); 748 } 749 sendorfree: 750 if (error) { 751 for (m = m0; m; m = m0) { 752 m0 = m->m_nextpkt; 753 m->m_nextpkt = NULL; 754 m_freem(m); 755 } 756 } 757 758 return (error); 759 } 760 761 /* 762 * Insert IP options into preformed packet. 763 * Adjust IP destination as required for IP source routing, 764 * as indicated by a non-zero in_addr at the start of the options. 765 */ 766 struct mbuf * 767 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 768 { 769 struct ipoption *p = mtod(opt, struct ipoption *); 770 struct mbuf *n; 771 struct ip *ip = mtod(m, struct ip *); 772 unsigned int optlen; 773 774 optlen = opt->m_len - sizeof(p->ipopt_dst); 775 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 776 return (m); /* XXX should fail */ 777 if (p->ipopt_dst.s_addr) 778 ip->ip_dst = p->ipopt_dst; 779 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 780 MGETHDR(n, M_DONTWAIT, MT_HEADER); 781 if (n == NULL) 782 return (m); 783 M_MOVE_HDR(n, m); 784 n->m_pkthdr.len += optlen; 785 m->m_len -= sizeof(struct ip); 786 m->m_data += sizeof(struct ip); 787 n->m_next = m; 788 m = n; 789 m->m_len = optlen + sizeof(struct ip); 790 m->m_data += max_linkhdr; 791 memcpy(mtod(m, caddr_t), ip, sizeof(struct ip)); 792 } else { 793 m->m_data -= optlen; 794 m->m_len += optlen; 795 m->m_pkthdr.len += optlen; 796 memmove(mtod(m, caddr_t), (caddr_t)ip, sizeof(struct ip)); 797 } 798 ip = mtod(m, struct ip *); 799 memcpy(ip + 1, p->ipopt_list, optlen); 800 *phlen = sizeof(struct ip) + optlen; 801 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 802 return (m); 803 } 804 805 /* 806 * Copy options from ip to jp, 807 * omitting those not copied during fragmentation. 808 */ 809 int 810 ip_optcopy(struct ip *ip, struct ip *jp) 811 { 812 u_char *cp, *dp; 813 int opt, optlen, cnt; 814 815 cp = (u_char *)(ip + 1); 816 dp = (u_char *)(jp + 1); 817 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 818 for (; cnt > 0; cnt -= optlen, cp += optlen) { 819 opt = cp[0]; 820 if (opt == IPOPT_EOL) 821 break; 822 if (opt == IPOPT_NOP) { 823 /* Preserve for IP mcast tunnel's LSRR alignment. */ 824 *dp++ = IPOPT_NOP; 825 optlen = 1; 826 continue; 827 } 828 #ifdef DIAGNOSTIC 829 if (cnt < IPOPT_OLEN + sizeof(*cp)) 830 panic("malformed IPv4 option passed to ip_optcopy"); 831 #endif 832 optlen = cp[IPOPT_OLEN]; 833 #ifdef DIAGNOSTIC 834 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 835 panic("malformed IPv4 option passed to ip_optcopy"); 836 #endif 837 /* bogus lengths should have been caught by ip_dooptions */ 838 if (optlen > cnt) 839 optlen = cnt; 840 if (IPOPT_COPIED(opt)) { 841 memcpy(dp, cp, optlen); 842 dp += optlen; 843 } 844 } 845 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 846 *dp++ = IPOPT_EOL; 847 return (optlen); 848 } 849 850 /* 851 * IP socket option processing. 852 */ 853 int 854 ip_ctloutput(int op, struct socket *so, int level, int optname, 855 struct mbuf *m) 856 { 857 struct inpcb *inp = sotoinpcb(so); 858 int optval = 0; 859 struct proc *p = curproc; /* XXX */ 860 int error = 0; 861 u_int rtid = 0; 862 863 if (level != IPPROTO_IP) { 864 error = EINVAL; 865 } else switch (op) { 866 case PRCO_SETOPT: 867 switch (optname) { 868 case IP_OPTIONS: 869 return (ip_pcbopts(&inp->inp_options, m)); 870 871 case IP_TOS: 872 case IP_TTL: 873 case IP_MINTTL: 874 case IP_RECVOPTS: 875 case IP_RECVRETOPTS: 876 case IP_RECVDSTADDR: 877 case IP_RECVIF: 878 case IP_RECVTTL: 879 case IP_RECVDSTPORT: 880 case IP_RECVRTABLE: 881 case IP_IPSECFLOWINFO: 882 if (m == NULL || m->m_len != sizeof(int)) 883 error = EINVAL; 884 else { 885 optval = *mtod(m, int *); 886 switch (optname) { 887 888 case IP_TOS: 889 inp->inp_ip.ip_tos = optval; 890 break; 891 892 case IP_TTL: 893 if (optval > 0 && optval <= MAXTTL) 894 inp->inp_ip.ip_ttl = optval; 895 else if (optval == -1) 896 inp->inp_ip.ip_ttl = ip_defttl; 897 else 898 error = EINVAL; 899 break; 900 901 case IP_MINTTL: 902 if (optval >= 0 && optval <= MAXTTL) 903 inp->inp_ip_minttl = optval; 904 else 905 error = EINVAL; 906 break; 907 #define OPTSET(bit) \ 908 if (optval) \ 909 inp->inp_flags |= bit; \ 910 else \ 911 inp->inp_flags &= ~bit; 912 913 case IP_RECVOPTS: 914 OPTSET(INP_RECVOPTS); 915 break; 916 917 case IP_RECVRETOPTS: 918 OPTSET(INP_RECVRETOPTS); 919 break; 920 921 case IP_RECVDSTADDR: 922 OPTSET(INP_RECVDSTADDR); 923 break; 924 case IP_RECVIF: 925 OPTSET(INP_RECVIF); 926 break; 927 case IP_RECVTTL: 928 OPTSET(INP_RECVTTL); 929 break; 930 case IP_RECVDSTPORT: 931 OPTSET(INP_RECVDSTPORT); 932 break; 933 case IP_RECVRTABLE: 934 OPTSET(INP_RECVRTABLE); 935 break; 936 case IP_IPSECFLOWINFO: 937 OPTSET(INP_IPSECFLOWINFO); 938 break; 939 } 940 } 941 break; 942 #undef OPTSET 943 944 case IP_MULTICAST_IF: 945 case IP_MULTICAST_TTL: 946 case IP_MULTICAST_LOOP: 947 case IP_ADD_MEMBERSHIP: 948 case IP_DROP_MEMBERSHIP: 949 error = ip_setmoptions(optname, &inp->inp_moptions, m, 950 inp->inp_rtableid); 951 break; 952 953 case IP_PORTRANGE: 954 if (m == NULL || m->m_len != sizeof(int)) 955 error = EINVAL; 956 else { 957 optval = *mtod(m, int *); 958 959 switch (optval) { 960 961 case IP_PORTRANGE_DEFAULT: 962 inp->inp_flags &= ~(INP_LOWPORT); 963 inp->inp_flags &= ~(INP_HIGHPORT); 964 break; 965 966 case IP_PORTRANGE_HIGH: 967 inp->inp_flags &= ~(INP_LOWPORT); 968 inp->inp_flags |= INP_HIGHPORT; 969 break; 970 971 case IP_PORTRANGE_LOW: 972 inp->inp_flags &= ~(INP_HIGHPORT); 973 inp->inp_flags |= INP_LOWPORT; 974 break; 975 976 default: 977 978 error = EINVAL; 979 break; 980 } 981 } 982 break; 983 case IP_AUTH_LEVEL: 984 case IP_ESP_TRANS_LEVEL: 985 case IP_ESP_NETWORK_LEVEL: 986 case IP_IPCOMP_LEVEL: 987 #ifndef IPSEC 988 error = EOPNOTSUPP; 989 #else 990 if (m == NULL || m->m_len != sizeof(int)) { 991 error = EINVAL; 992 break; 993 } 994 optval = *mtod(m, int *); 995 996 if (optval < IPSEC_LEVEL_BYPASS || 997 optval > IPSEC_LEVEL_UNIQUE) { 998 error = EINVAL; 999 break; 1000 } 1001 1002 switch (optname) { 1003 case IP_AUTH_LEVEL: 1004 if (optval < IPSEC_AUTH_LEVEL_DEFAULT && 1005 suser(p)) { 1006 error = EACCES; 1007 break; 1008 } 1009 inp->inp_seclevel[SL_AUTH] = optval; 1010 break; 1011 1012 case IP_ESP_TRANS_LEVEL: 1013 if (optval < IPSEC_ESP_TRANS_LEVEL_DEFAULT && 1014 suser(p)) { 1015 error = EACCES; 1016 break; 1017 } 1018 inp->inp_seclevel[SL_ESP_TRANS] = optval; 1019 break; 1020 1021 case IP_ESP_NETWORK_LEVEL: 1022 if (optval < IPSEC_ESP_NETWORK_LEVEL_DEFAULT && 1023 suser(p)) { 1024 error = EACCES; 1025 break; 1026 } 1027 inp->inp_seclevel[SL_ESP_NETWORK] = optval; 1028 break; 1029 case IP_IPCOMP_LEVEL: 1030 if (optval < IPSEC_IPCOMP_LEVEL_DEFAULT && 1031 suser(p)) { 1032 error = EACCES; 1033 break; 1034 } 1035 inp->inp_seclevel[SL_IPCOMP] = optval; 1036 break; 1037 } 1038 #endif 1039 break; 1040 1041 case IP_IPSEC_LOCAL_ID: 1042 case IP_IPSEC_REMOTE_ID: 1043 error = EOPNOTSUPP; 1044 break; 1045 case SO_RTABLE: 1046 if (m == NULL || m->m_len < sizeof(u_int)) { 1047 error = EINVAL; 1048 break; 1049 } 1050 rtid = *mtod(m, u_int *); 1051 if (inp->inp_rtableid == rtid) 1052 break; 1053 /* needs privileges to switch when already set */ 1054 if (p->p_p->ps_rtableid != rtid && 1055 p->p_p->ps_rtableid != 0 && 1056 (error = suser(p)) != 0) 1057 break; 1058 /* table must exist */ 1059 if (!rtable_exists(rtid)) { 1060 error = EINVAL; 1061 break; 1062 } 1063 if (inp->inp_lport) { 1064 error = EBUSY; 1065 break; 1066 } 1067 inp->inp_rtableid = rtid; 1068 in_pcbrehash(inp); 1069 break; 1070 case IP_PIPEX: 1071 if (m != NULL && m->m_len == sizeof(int)) 1072 inp->inp_pipex = *mtod(m, int *); 1073 else 1074 error = EINVAL; 1075 break; 1076 1077 default: 1078 error = ENOPROTOOPT; 1079 break; 1080 } 1081 break; 1082 1083 case PRCO_GETOPT: 1084 switch (optname) { 1085 case IP_OPTIONS: 1086 case IP_RETOPTS: 1087 if (inp->inp_options) { 1088 m->m_len = inp->inp_options->m_len; 1089 memcpy(mtod(m, caddr_t), 1090 mtod(inp->inp_options, caddr_t), m->m_len); 1091 } else 1092 m->m_len = 0; 1093 break; 1094 1095 case IP_TOS: 1096 case IP_TTL: 1097 case IP_MINTTL: 1098 case IP_RECVOPTS: 1099 case IP_RECVRETOPTS: 1100 case IP_RECVDSTADDR: 1101 case IP_RECVIF: 1102 case IP_RECVTTL: 1103 case IP_RECVDSTPORT: 1104 case IP_RECVRTABLE: 1105 case IP_IPSECFLOWINFO: 1106 case IP_IPDEFTTL: 1107 m->m_len = sizeof(int); 1108 switch (optname) { 1109 1110 case IP_TOS: 1111 optval = inp->inp_ip.ip_tos; 1112 break; 1113 1114 case IP_TTL: 1115 optval = inp->inp_ip.ip_ttl; 1116 break; 1117 1118 case IP_MINTTL: 1119 optval = inp->inp_ip_minttl; 1120 break; 1121 1122 case IP_IPDEFTTL: 1123 optval = ip_defttl; 1124 break; 1125 1126 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1127 1128 case IP_RECVOPTS: 1129 optval = OPTBIT(INP_RECVOPTS); 1130 break; 1131 1132 case IP_RECVRETOPTS: 1133 optval = OPTBIT(INP_RECVRETOPTS); 1134 break; 1135 1136 case IP_RECVDSTADDR: 1137 optval = OPTBIT(INP_RECVDSTADDR); 1138 break; 1139 case IP_RECVIF: 1140 optval = OPTBIT(INP_RECVIF); 1141 break; 1142 case IP_RECVTTL: 1143 optval = OPTBIT(INP_RECVTTL); 1144 break; 1145 case IP_RECVDSTPORT: 1146 optval = OPTBIT(INP_RECVDSTPORT); 1147 break; 1148 case IP_RECVRTABLE: 1149 optval = OPTBIT(INP_RECVRTABLE); 1150 break; 1151 case IP_IPSECFLOWINFO: 1152 optval = OPTBIT(INP_IPSECFLOWINFO); 1153 break; 1154 } 1155 *mtod(m, int *) = optval; 1156 break; 1157 1158 case IP_MULTICAST_IF: 1159 case IP_MULTICAST_TTL: 1160 case IP_MULTICAST_LOOP: 1161 case IP_ADD_MEMBERSHIP: 1162 case IP_DROP_MEMBERSHIP: 1163 error = ip_getmoptions(optname, inp->inp_moptions, m); 1164 break; 1165 1166 case IP_PORTRANGE: 1167 m->m_len = sizeof(int); 1168 1169 if (inp->inp_flags & INP_HIGHPORT) 1170 optval = IP_PORTRANGE_HIGH; 1171 else if (inp->inp_flags & INP_LOWPORT) 1172 optval = IP_PORTRANGE_LOW; 1173 else 1174 optval = 0; 1175 1176 *mtod(m, int *) = optval; 1177 break; 1178 1179 case IP_AUTH_LEVEL: 1180 case IP_ESP_TRANS_LEVEL: 1181 case IP_ESP_NETWORK_LEVEL: 1182 case IP_IPCOMP_LEVEL: 1183 #ifndef IPSEC 1184 m->m_len = sizeof(int); 1185 *mtod(m, int *) = IPSEC_LEVEL_NONE; 1186 #else 1187 m->m_len = sizeof(int); 1188 switch (optname) { 1189 case IP_AUTH_LEVEL: 1190 optval = inp->inp_seclevel[SL_AUTH]; 1191 break; 1192 1193 case IP_ESP_TRANS_LEVEL: 1194 optval = inp->inp_seclevel[SL_ESP_TRANS]; 1195 break; 1196 1197 case IP_ESP_NETWORK_LEVEL: 1198 optval = inp->inp_seclevel[SL_ESP_NETWORK]; 1199 break; 1200 case IP_IPCOMP_LEVEL: 1201 optval = inp->inp_seclevel[SL_IPCOMP]; 1202 break; 1203 } 1204 *mtod(m, int *) = optval; 1205 #endif 1206 break; 1207 case IP_IPSEC_LOCAL_ID: 1208 case IP_IPSEC_REMOTE_ID: 1209 error = EOPNOTSUPP; 1210 break; 1211 case SO_RTABLE: 1212 m->m_len = sizeof(u_int); 1213 *mtod(m, u_int *) = inp->inp_rtableid; 1214 break; 1215 case IP_PIPEX: 1216 m->m_len = sizeof(int); 1217 *mtod(m, int *) = inp->inp_pipex; 1218 break; 1219 default: 1220 error = ENOPROTOOPT; 1221 break; 1222 } 1223 break; 1224 } 1225 return (error); 1226 } 1227 1228 /* 1229 * Set up IP options in pcb for insertion in output packets. 1230 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1231 * with destination address if source routed. 1232 */ 1233 int 1234 ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) 1235 { 1236 int cnt, optlen; 1237 u_char *cp; 1238 u_char opt; 1239 1240 /* turn off any old options */ 1241 m_free(*pcbopt); 1242 *pcbopt = 0; 1243 if (m == NULL || m->m_len == 0) { 1244 /* 1245 * Only turning off any previous options. 1246 */ 1247 return (0); 1248 } 1249 1250 if (m->m_len % sizeof(int32_t)) 1251 return (EINVAL); 1252 1253 /* 1254 * IP first-hop destination address will be stored before 1255 * actual options; move other options back 1256 * and clear it when none present. 1257 */ 1258 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1259 return (EINVAL); 1260 cnt = m->m_len; 1261 m->m_len += sizeof(struct in_addr); 1262 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1263 memmove((caddr_t)cp, mtod(m, caddr_t), (unsigned)cnt); 1264 memset(mtod(m, caddr_t), 0, sizeof(struct in_addr)); 1265 1266 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1267 opt = cp[IPOPT_OPTVAL]; 1268 if (opt == IPOPT_EOL) 1269 break; 1270 if (opt == IPOPT_NOP) 1271 optlen = 1; 1272 else { 1273 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1274 return (EINVAL); 1275 optlen = cp[IPOPT_OLEN]; 1276 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1277 return (EINVAL); 1278 } 1279 switch (opt) { 1280 1281 default: 1282 break; 1283 1284 case IPOPT_LSRR: 1285 case IPOPT_SSRR: 1286 /* 1287 * user process specifies route as: 1288 * ->A->B->C->D 1289 * D must be our final destination (but we can't 1290 * check that since we may not have connected yet). 1291 * A is first hop destination, which doesn't appear in 1292 * actual IP option, but is stored before the options. 1293 */ 1294 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1295 return (EINVAL); 1296 m->m_len -= sizeof(struct in_addr); 1297 cnt -= sizeof(struct in_addr); 1298 optlen -= sizeof(struct in_addr); 1299 cp[IPOPT_OLEN] = optlen; 1300 /* 1301 * Move first hop before start of options. 1302 */ 1303 memcpy(mtod(m, caddr_t), &cp[IPOPT_OFFSET+1], 1304 sizeof(struct in_addr)); 1305 /* 1306 * Then copy rest of options back 1307 * to close up the deleted entry. 1308 */ 1309 memmove((caddr_t)&cp[IPOPT_OFFSET+1], 1310 (caddr_t)(&cp[IPOPT_OFFSET+1] + 1311 sizeof(struct in_addr)), 1312 (unsigned)cnt - (IPOPT_OFFSET+1)); 1313 break; 1314 } 1315 } 1316 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1317 return (EINVAL); 1318 *pcbopt = m_copym(m, 0, M_COPYALL, M_NOWAIT); 1319 if (*pcbopt == NULL) 1320 return (ENOBUFS); 1321 1322 return (0); 1323 } 1324 1325 /* 1326 * Set the IP multicast options in response to user setsockopt(). 1327 */ 1328 int 1329 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m, 1330 u_int rtableid) 1331 { 1332 struct in_addr addr; 1333 struct in_ifaddr *ia; 1334 struct ip_mreq *mreq; 1335 struct ifnet *ifp = NULL; 1336 struct ip_moptions *imo = *imop; 1337 struct in_multi **immp; 1338 struct rtentry *rt; 1339 struct sockaddr_in sin; 1340 int i, error = 0; 1341 u_char loop; 1342 1343 if (imo == NULL) { 1344 /* 1345 * No multicast option buffer attached to the pcb; 1346 * allocate one and initialize to default values. 1347 */ 1348 imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK|M_ZERO); 1349 immp = (struct in_multi **)malloc( 1350 (sizeof(*immp) * IP_MIN_MEMBERSHIPS), M_IPMOPTS, 1351 M_WAITOK|M_ZERO); 1352 *imop = imo; 1353 imo->imo_ifidx = 0; 1354 imo->imo_ttl = IP_DEFAULT_MULTICAST_TTL; 1355 imo->imo_loop = IP_DEFAULT_MULTICAST_LOOP; 1356 imo->imo_num_memberships = 0; 1357 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; 1358 imo->imo_membership = immp; 1359 } 1360 1361 switch (optname) { 1362 1363 case IP_MULTICAST_IF: 1364 /* 1365 * Select the interface for outgoing multicast packets. 1366 */ 1367 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1368 error = EINVAL; 1369 break; 1370 } 1371 addr = *(mtod(m, struct in_addr *)); 1372 /* 1373 * INADDR_ANY is used to remove a previous selection. 1374 * When no interface is selected, a default one is 1375 * chosen every time a multicast packet is sent. 1376 */ 1377 if (addr.s_addr == INADDR_ANY) { 1378 imo->imo_ifidx = 0; 1379 break; 1380 } 1381 /* 1382 * The selected interface is identified by its local 1383 * IP address. Find the interface and confirm that 1384 * it supports multicasting. 1385 */ 1386 memset(&sin, 0, sizeof(sin)); 1387 sin.sin_len = sizeof(sin); 1388 sin.sin_family = AF_INET; 1389 sin.sin_addr = addr; 1390 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1391 if (ia == NULL || 1392 (ia->ia_ifp->if_flags & IFF_MULTICAST) == 0) { 1393 error = EADDRNOTAVAIL; 1394 break; 1395 } 1396 imo->imo_ifidx = ia->ia_ifp->if_index; 1397 break; 1398 1399 case IP_MULTICAST_TTL: 1400 /* 1401 * Set the IP time-to-live for outgoing multicast packets. 1402 */ 1403 if (m == NULL || m->m_len != 1) { 1404 error = EINVAL; 1405 break; 1406 } 1407 imo->imo_ttl = *(mtod(m, u_char *)); 1408 break; 1409 1410 case IP_MULTICAST_LOOP: 1411 /* 1412 * Set the loopback flag for outgoing multicast packets. 1413 * Must be zero or one. 1414 */ 1415 if (m == NULL || m->m_len != 1 || 1416 (loop = *(mtod(m, u_char *))) > 1) { 1417 error = EINVAL; 1418 break; 1419 } 1420 imo->imo_loop = loop; 1421 break; 1422 1423 case IP_ADD_MEMBERSHIP: 1424 /* 1425 * Add a multicast group membership. 1426 * Group must be a valid IP multicast address. 1427 */ 1428 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1429 error = EINVAL; 1430 break; 1431 } 1432 mreq = mtod(m, struct ip_mreq *); 1433 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1434 error = EINVAL; 1435 break; 1436 } 1437 /* 1438 * If no interface address was provided, use the interface of 1439 * the route to the given multicast address. 1440 */ 1441 if (mreq->imr_interface.s_addr == INADDR_ANY) { 1442 memset(&sin, 0, sizeof(sin)); 1443 sin.sin_len = sizeof(sin); 1444 sin.sin_family = AF_INET; 1445 sin.sin_addr = mreq->imr_multiaddr; 1446 rt = rtalloc(sintosa(&sin), RT_RESOLVE, rtableid); 1447 if (!rtisvalid(rt)) { 1448 rtfree(rt); 1449 error = EADDRNOTAVAIL; 1450 break; 1451 } 1452 } else { 1453 memset(&sin, 0, sizeof(sin)); 1454 sin.sin_len = sizeof(sin); 1455 sin.sin_family = AF_INET; 1456 sin.sin_addr = mreq->imr_interface; 1457 rt = rtalloc(sintosa(&sin), 0, rtableid); 1458 if (!rtisvalid(rt) || !ISSET(rt->rt_flags, RTF_LOCAL)) { 1459 rtfree(rt); 1460 error = EADDRNOTAVAIL; 1461 break; 1462 } 1463 } 1464 ifp = if_get(rt->rt_ifidx); 1465 rtfree(rt); 1466 1467 /* 1468 * See if we found an interface, and confirm that it 1469 * supports multicast. 1470 */ 1471 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1472 error = EADDRNOTAVAIL; 1473 if_put(ifp); 1474 break; 1475 } 1476 /* 1477 * See if the membership already exists or if all the 1478 * membership slots are full. 1479 */ 1480 for (i = 0; i < imo->imo_num_memberships; ++i) { 1481 if (imo->imo_membership[i]->inm_ifidx 1482 == ifp->if_index && 1483 imo->imo_membership[i]->inm_addr.s_addr 1484 == mreq->imr_multiaddr.s_addr) 1485 break; 1486 } 1487 if (i < imo->imo_num_memberships) { 1488 error = EADDRINUSE; 1489 if_put(ifp); 1490 break; 1491 } 1492 if (imo->imo_num_memberships == imo->imo_max_memberships) { 1493 struct in_multi **nmships, **omships; 1494 size_t newmax; 1495 /* 1496 * Resize the vector to next power-of-two minus 1. If the 1497 * size would exceed the maximum then we know we've really 1498 * run out of entries. Otherwise, we reallocate the vector. 1499 */ 1500 nmships = NULL; 1501 omships = imo->imo_membership; 1502 newmax = ((imo->imo_max_memberships + 1) * 2) - 1; 1503 if (newmax <= IP_MAX_MEMBERSHIPS) { 1504 nmships = (struct in_multi **)mallocarray( 1505 newmax, sizeof(*nmships), M_IPMOPTS, 1506 M_NOWAIT|M_ZERO); 1507 if (nmships != NULL) { 1508 memcpy(nmships, omships, 1509 sizeof(*omships) * 1510 imo->imo_max_memberships); 1511 free(omships, M_IPMOPTS, 1512 sizeof(*omships) * 1513 imo->imo_max_memberships); 1514 imo->imo_membership = nmships; 1515 imo->imo_max_memberships = newmax; 1516 } 1517 } 1518 if (nmships == NULL) { 1519 error = ENOBUFS; 1520 if_put(ifp); 1521 break; 1522 } 1523 } 1524 /* 1525 * Everything looks good; add a new record to the multicast 1526 * address list for the given interface. 1527 */ 1528 if ((imo->imo_membership[i] = 1529 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1530 error = ENOBUFS; 1531 if_put(ifp); 1532 break; 1533 } 1534 ++imo->imo_num_memberships; 1535 if_put(ifp); 1536 break; 1537 1538 case IP_DROP_MEMBERSHIP: 1539 /* 1540 * Drop a multicast group membership. 1541 * Group must be a valid IP multicast address. 1542 */ 1543 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1544 error = EINVAL; 1545 break; 1546 } 1547 mreq = mtod(m, struct ip_mreq *); 1548 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1549 error = EINVAL; 1550 break; 1551 } 1552 /* 1553 * If an interface address was specified, get a pointer 1554 * to its ifnet structure. 1555 */ 1556 if (mreq->imr_interface.s_addr == INADDR_ANY) 1557 ifp = NULL; 1558 else { 1559 memset(&sin, 0, sizeof(sin)); 1560 sin.sin_len = sizeof(sin); 1561 sin.sin_family = AF_INET; 1562 sin.sin_addr = mreq->imr_interface; 1563 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1564 if (ia == NULL) { 1565 error = EADDRNOTAVAIL; 1566 break; 1567 } 1568 ifp = ia->ia_ifp; 1569 } 1570 /* 1571 * Find the membership in the membership array. 1572 */ 1573 for (i = 0; i < imo->imo_num_memberships; ++i) { 1574 if ((ifp == NULL || 1575 imo->imo_membership[i]->inm_ifidx == 1576 ifp->if_index) && 1577 imo->imo_membership[i]->inm_addr.s_addr == 1578 mreq->imr_multiaddr.s_addr) 1579 break; 1580 } 1581 if (i == imo->imo_num_memberships) { 1582 error = EADDRNOTAVAIL; 1583 break; 1584 } 1585 /* 1586 * Give up the multicast address record to which the 1587 * membership points. 1588 */ 1589 in_delmulti(imo->imo_membership[i]); 1590 /* 1591 * Remove the gap in the membership array. 1592 */ 1593 for (++i; i < imo->imo_num_memberships; ++i) 1594 imo->imo_membership[i-1] = imo->imo_membership[i]; 1595 --imo->imo_num_memberships; 1596 break; 1597 1598 default: 1599 error = EOPNOTSUPP; 1600 break; 1601 } 1602 1603 /* 1604 * If all options have default values, no need to keep the data. 1605 */ 1606 if (imo->imo_ifidx == 0 && 1607 imo->imo_ttl == IP_DEFAULT_MULTICAST_TTL && 1608 imo->imo_loop == IP_DEFAULT_MULTICAST_LOOP && 1609 imo->imo_num_memberships == 0) { 1610 free(imo->imo_membership , M_IPMOPTS, 0); 1611 free(*imop, M_IPMOPTS, sizeof(**imop)); 1612 *imop = NULL; 1613 } 1614 1615 return (error); 1616 } 1617 1618 /* 1619 * Return the IP multicast options in response to user getsockopt(). 1620 */ 1621 int 1622 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf *m) 1623 { 1624 u_char *ttl; 1625 u_char *loop; 1626 struct in_addr *addr; 1627 struct in_ifaddr *ia; 1628 struct ifnet *ifp; 1629 1630 switch (optname) { 1631 1632 case IP_MULTICAST_IF: 1633 addr = mtod(m, struct in_addr *); 1634 m->m_len = sizeof(struct in_addr); 1635 if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL) 1636 addr->s_addr = INADDR_ANY; 1637 else { 1638 IFP_TO_IA(ifp, ia); 1639 if_put(ifp); 1640 addr->s_addr = (ia == NULL) ? INADDR_ANY 1641 : ia->ia_addr.sin_addr.s_addr; 1642 } 1643 return (0); 1644 1645 case IP_MULTICAST_TTL: 1646 ttl = mtod(m, u_char *); 1647 m->m_len = 1; 1648 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1649 : imo->imo_ttl; 1650 return (0); 1651 1652 case IP_MULTICAST_LOOP: 1653 loop = mtod(m, u_char *); 1654 m->m_len = 1; 1655 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1656 : imo->imo_loop; 1657 return (0); 1658 1659 default: 1660 return (EOPNOTSUPP); 1661 } 1662 } 1663 1664 /* 1665 * Discard the IP multicast options. 1666 */ 1667 void 1668 ip_freemoptions(struct ip_moptions *imo) 1669 { 1670 int i; 1671 1672 if (imo != NULL) { 1673 for (i = 0; i < imo->imo_num_memberships; ++i) 1674 in_delmulti(imo->imo_membership[i]); 1675 free(imo->imo_membership, M_IPMOPTS, 0); 1676 free(imo, M_IPMOPTS, sizeof(*imo)); 1677 } 1678 } 1679 1680 /* 1681 * Routine called from ip_output() to loop back a copy of an IP multicast 1682 * packet to the input queue of a specified interface. 1683 */ 1684 void 1685 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1686 { 1687 struct ip *ip; 1688 struct mbuf *copym; 1689 1690 copym = m_dup_pkt(m, max_linkhdr, M_DONTWAIT); 1691 if (copym != NULL) { 1692 /* 1693 * We don't bother to fragment if the IP length is greater 1694 * than the interface's MTU. Can this possibly matter? 1695 */ 1696 ip = mtod(copym, struct ip *); 1697 ip->ip_sum = 0; 1698 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1699 if_input_local(ifp, copym, dst->sin_family); 1700 } 1701 } 1702 1703 /* 1704 * Compute significant parts of the IPv4 checksum pseudo-header 1705 * for use in a delayed TCP/UDP checksum calculation. 1706 */ 1707 static __inline u_int16_t __attribute__((__unused__)) 1708 in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) 1709 { 1710 u_int32_t sum; 1711 1712 sum = lenproto + 1713 (u_int16_t)(src >> 16) + 1714 (u_int16_t)(src /*& 0xffff*/) + 1715 (u_int16_t)(dst >> 16) + 1716 (u_int16_t)(dst /*& 0xffff*/); 1717 1718 sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); 1719 1720 if (sum > 0xffff) 1721 sum -= 0xffff; 1722 1723 return (sum); 1724 } 1725 1726 /* 1727 * Process a delayed payload checksum calculation. 1728 */ 1729 void 1730 in_delayed_cksum(struct mbuf *m) 1731 { 1732 struct ip *ip; 1733 u_int16_t csum, offset; 1734 1735 ip = mtod(m, struct ip *); 1736 offset = ip->ip_hl << 2; 1737 csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset); 1738 if (csum == 0 && ip->ip_p == IPPROTO_UDP) 1739 csum = 0xffff; 1740 1741 switch (ip->ip_p) { 1742 case IPPROTO_TCP: 1743 offset += offsetof(struct tcphdr, th_sum); 1744 break; 1745 1746 case IPPROTO_UDP: 1747 offset += offsetof(struct udphdr, uh_sum); 1748 break; 1749 1750 case IPPROTO_ICMP: 1751 offset += offsetof(struct icmp, icmp_cksum); 1752 break; 1753 1754 default: 1755 return; 1756 } 1757 1758 if ((offset + sizeof(u_int16_t)) > m->m_len) 1759 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1760 else 1761 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1762 } 1763 1764 void 1765 in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp) 1766 { 1767 struct ip *ip = mtod(m, struct ip *); 1768 1769 /* some hw and in_delayed_cksum need the pseudo header cksum */ 1770 if (m->m_pkthdr.csum_flags & 1771 (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT|M_ICMP_CSUM_OUT)) { 1772 u_int16_t csum = 0, offset; 1773 1774 offset = ip->ip_hl << 2; 1775 if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) 1776 csum = in_cksum_phdr(ip->ip_src.s_addr, 1777 ip->ip_dst.s_addr, htonl(ntohs(ip->ip_len) - 1778 offset + ip->ip_p)); 1779 if (ip->ip_p == IPPROTO_TCP) 1780 offset += offsetof(struct tcphdr, th_sum); 1781 else if (ip->ip_p == IPPROTO_UDP) 1782 offset += offsetof(struct udphdr, uh_sum); 1783 else if (ip->ip_p == IPPROTO_ICMP) 1784 offset += offsetof(struct icmp, icmp_cksum); 1785 if ((offset + sizeof(u_int16_t)) > m->m_len) 1786 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1787 else 1788 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1789 } 1790 1791 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) { 1792 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || 1793 ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { 1794 tcpstat_inc(tcps_outswcsum); 1795 in_delayed_cksum(m); 1796 m->m_pkthdr.csum_flags &= ~M_TCP_CSUM_OUT; /* Clear */ 1797 } 1798 } else if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) { 1799 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || 1800 ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { 1801 udpstat_inc(udps_outswcsum); 1802 in_delayed_cksum(m); 1803 m->m_pkthdr.csum_flags &= ~M_UDP_CSUM_OUT; /* Clear */ 1804 } 1805 } else if (m->m_pkthdr.csum_flags & M_ICMP_CSUM_OUT) { 1806 in_delayed_cksum(m); 1807 m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */ 1808 } 1809 } 1810