1 /* $OpenBSD: ip_output.c,v 1.359 2021/01/07 14:51:46 claudio 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_multicast_if(struct ip_mreqn *, u_int, unsigned int *); 77 int ip_setmoptions(int, struct ip_moptions **, struct mbuf *, u_int); 78 void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); 79 static __inline u_int16_t __attribute__((__unused__)) 80 in_cksum_phdr(u_int32_t, u_int32_t, u_int32_t); 81 void in_delayed_cksum(struct mbuf *); 82 83 #ifdef IPSEC 84 struct tdb * 85 ip_output_ipsec_lookup(struct mbuf *m, int hlen, int *error, struct inpcb *inp, 86 int ipsecflowinfo); 87 int 88 ip_output_ipsec_send(struct tdb *, struct mbuf *, struct route *, int); 89 #endif /* IPSEC */ 90 91 /* 92 * IP output. The packet in mbuf chain m contains a skeletal IP 93 * header (with len, off, ttl, proto, tos, src, dst). 94 * The mbuf chain containing the packet will be freed. 95 * The mbuf opt, if present, will not be freed. 96 */ 97 int 98 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 99 struct ip_moptions *imo, struct inpcb *inp, u_int32_t ipsecflowinfo) 100 { 101 struct ip *ip; 102 struct ifnet *ifp = NULL; 103 struct mbuf *m = m0; 104 int hlen = sizeof (struct ip); 105 int error = 0; 106 struct route iproute; 107 struct sockaddr_in *dst; 108 struct tdb *tdb = NULL; 109 u_long mtu; 110 #if defined(MROUTING) 111 int rv; 112 #endif 113 114 NET_ASSERT_LOCKED(); 115 116 #ifdef IPSEC 117 if (inp && (inp->inp_flags & INP_IPV6) != 0) 118 panic("ip_output: IPv6 pcb is passed"); 119 #endif /* IPSEC */ 120 121 #ifdef DIAGNOSTIC 122 if ((m->m_flags & M_PKTHDR) == 0) 123 panic("ip_output no HDR"); 124 #endif 125 if (opt) 126 m = ip_insertoptions(m, opt, &hlen); 127 128 ip = mtod(m, struct ip *); 129 130 /* 131 * Fill in IP header. 132 */ 133 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 134 ip->ip_v = IPVERSION; 135 ip->ip_off &= htons(IP_DF); 136 ip->ip_id = htons(ip_randomid()); 137 ip->ip_hl = hlen >> 2; 138 ipstat_inc(ips_localout); 139 } else { 140 hlen = ip->ip_hl << 2; 141 } 142 143 /* 144 * We should not send traffic to 0/8 say both Stevens and RFCs 145 * 5735 section 3 and 1122 sections 3.2.1.3 and 3.3.6. 146 */ 147 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == 0) { 148 error = ENETUNREACH; 149 goto bad; 150 } 151 152 #if NPF > 0 153 reroute: 154 #endif 155 156 /* 157 * Do a route lookup now in case we need the source address to 158 * do an SPD lookup in IPsec; for most packets, the source address 159 * is set at a higher level protocol. ICMPs and other packets 160 * though (e.g., traceroute) have a source address of zeroes. 161 */ 162 if (ro == NULL) { 163 ro = &iproute; 164 memset(ro, 0, sizeof(*ro)); 165 } 166 167 dst = satosin(&ro->ro_dst); 168 169 /* 170 * If there is a cached route, check that it is to the same 171 * destination and is still up. If not, free it and try again. 172 */ 173 if (!rtisvalid(ro->ro_rt) || 174 dst->sin_addr.s_addr != ip->ip_dst.s_addr || 175 ro->ro_tableid != m->m_pkthdr.ph_rtableid) { 176 rtfree(ro->ro_rt); 177 ro->ro_rt = NULL; 178 } 179 180 if (ro->ro_rt == NULL) { 181 dst->sin_family = AF_INET; 182 dst->sin_len = sizeof(*dst); 183 dst->sin_addr = ip->ip_dst; 184 ro->ro_tableid = m->m_pkthdr.ph_rtableid; 185 } 186 187 if ((IN_MULTICAST(ip->ip_dst.s_addr) || 188 (ip->ip_dst.s_addr == INADDR_BROADCAST)) && 189 imo != NULL && (ifp = if_get(imo->imo_ifidx)) != NULL) { 190 191 mtu = ifp->if_mtu; 192 if (ip->ip_src.s_addr == INADDR_ANY) { 193 struct in_ifaddr *ia; 194 195 IFP_TO_IA(ifp, ia); 196 if (ia != NULL) 197 ip->ip_src = ia->ia_addr.sin_addr; 198 } 199 } else { 200 struct in_ifaddr *ia; 201 202 if (ro->ro_rt == NULL) 203 ro->ro_rt = rtalloc_mpath(&ro->ro_dst, 204 &ip->ip_src.s_addr, ro->ro_tableid); 205 206 if (ro->ro_rt == NULL) { 207 ipstat_inc(ips_noroute); 208 error = EHOSTUNREACH; 209 goto bad; 210 } 211 212 ia = ifatoia(ro->ro_rt->rt_ifa); 213 if (ISSET(ro->ro_rt->rt_flags, RTF_LOCAL)) 214 ifp = if_get(rtable_loindex(m->m_pkthdr.ph_rtableid)); 215 else 216 ifp = if_get(ro->ro_rt->rt_ifidx); 217 /* 218 * We aren't using rtisvalid() here because the UP/DOWN state 219 * machine is broken with some Ethernet drivers like em(4). 220 * As a result we might try to use an invalid cached route 221 * entry while an interface is being detached. 222 */ 223 if (ifp == NULL) { 224 ipstat_inc(ips_noroute); 225 error = EHOSTUNREACH; 226 goto bad; 227 } 228 if ((mtu = ro->ro_rt->rt_mtu) == 0) 229 mtu = ifp->if_mtu; 230 231 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 232 dst = satosin(ro->ro_rt->rt_gateway); 233 234 /* Set the source IP address */ 235 if (ip->ip_src.s_addr == INADDR_ANY && ia) 236 ip->ip_src = ia->ia_addr.sin_addr; 237 } 238 239 #ifdef IPSEC 240 if (ipsec_in_use || inp != NULL) { 241 /* Do we have any pending SAs to apply ? */ 242 tdb = ip_output_ipsec_lookup(m, hlen, &error, inp, 243 ipsecflowinfo); 244 if (error != 0) { 245 /* Should silently drop packet */ 246 if (error == -EINVAL) 247 error = 0; 248 m_freem(m); 249 goto done; 250 } 251 if (tdb != NULL) { 252 /* 253 * If it needs TCP/UDP hardware-checksumming, do the 254 * computation now. 255 */ 256 in_proto_cksum_out(m, NULL); 257 } 258 } 259 #endif /* IPSEC */ 260 261 if (IN_MULTICAST(ip->ip_dst.s_addr) || 262 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 263 264 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 265 M_BCAST : M_MCAST; 266 267 /* 268 * IP destination address is multicast. Make sure "dst" 269 * still points to the address in "ro". (It may have been 270 * changed to point to a gateway address, above.) 271 */ 272 dst = satosin(&ro->ro_dst); 273 274 /* 275 * See if the caller provided any multicast options 276 */ 277 if (imo != NULL) 278 ip->ip_ttl = imo->imo_ttl; 279 else 280 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 281 282 /* 283 * if we don't know the outgoing ifp yet, we can't generate 284 * output 285 */ 286 if (!ifp) { 287 ipstat_inc(ips_noroute); 288 error = EHOSTUNREACH; 289 goto bad; 290 } 291 292 /* 293 * Confirm that the outgoing interface supports multicast, 294 * but only if the packet actually is going out on that 295 * interface (i.e., no IPsec is applied). 296 */ 297 if ((((m->m_flags & M_MCAST) && 298 (ifp->if_flags & IFF_MULTICAST) == 0) || 299 ((m->m_flags & M_BCAST) && 300 (ifp->if_flags & IFF_BROADCAST) == 0)) && (tdb == NULL)) { 301 ipstat_inc(ips_noroute); 302 error = ENETUNREACH; 303 goto bad; 304 } 305 306 /* 307 * If source address not specified yet, use address 308 * of outgoing interface. 309 */ 310 if (ip->ip_src.s_addr == INADDR_ANY) { 311 struct in_ifaddr *ia; 312 313 IFP_TO_IA(ifp, ia); 314 if (ia != NULL) 315 ip->ip_src = ia->ia_addr.sin_addr; 316 } 317 318 if ((imo == NULL || imo->imo_loop) && 319 in_hasmulti(&ip->ip_dst, ifp)) { 320 /* 321 * If we belong to the destination multicast group 322 * on the outgoing interface, and the caller did not 323 * forbid loopback, loop back a copy. 324 * Can't defer TCP/UDP checksumming, do the 325 * computation now. 326 */ 327 in_proto_cksum_out(m, NULL); 328 ip_mloopback(ifp, m, dst); 329 } 330 #ifdef MROUTING 331 else { 332 /* 333 * If we are acting as a multicast router, perform 334 * multicast forwarding as if the packet had just 335 * arrived on the interface to which we are about 336 * to send. The multicast forwarding function 337 * recursively calls this function, using the 338 * IP_FORWARDING flag to prevent infinite recursion. 339 * 340 * Multicasts that are looped back by ip_mloopback(), 341 * above, will be forwarded by the ip_input() routine, 342 * if necessary. 343 */ 344 if (ipmforwarding && ip_mrouter[ifp->if_rdomain] && 345 (flags & IP_FORWARDING) == 0) { 346 KERNEL_LOCK(); 347 rv = ip_mforward(m, ifp); 348 KERNEL_UNLOCK(); 349 if (rv != 0) { 350 m_freem(m); 351 goto done; 352 } 353 } 354 } 355 #endif 356 /* 357 * Multicasts with a time-to-live of zero may be looped- 358 * back, above, but must not be transmitted on a network. 359 * Also, multicasts addressed to the loopback interface 360 * are not sent -- the above call to ip_mloopback() will 361 * loop back a copy if this host actually belongs to the 362 * destination group on the loopback interface. 363 */ 364 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 365 m_freem(m); 366 goto done; 367 } 368 369 goto sendit; 370 } 371 372 /* 373 * Look for broadcast address and verify user is allowed to send 374 * such a packet; if the packet is going in an IPsec tunnel, skip 375 * this check. 376 */ 377 if ((tdb == NULL) && ((dst->sin_addr.s_addr == INADDR_BROADCAST) || 378 (ro && ro->ro_rt && ISSET(ro->ro_rt->rt_flags, RTF_BROADCAST)))) { 379 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 380 error = EADDRNOTAVAIL; 381 goto bad; 382 } 383 if ((flags & IP_ALLOWBROADCAST) == 0) { 384 error = EACCES; 385 goto bad; 386 } 387 388 /* Don't allow broadcast messages to be fragmented */ 389 if (ntohs(ip->ip_len) > ifp->if_mtu) { 390 error = EMSGSIZE; 391 goto bad; 392 } 393 m->m_flags |= M_BCAST; 394 } else 395 m->m_flags &= ~M_BCAST; 396 397 sendit: 398 /* 399 * If we're doing Path MTU discovery, we need to set DF unless 400 * the route's MTU is locked. 401 */ 402 if ((flags & IP_MTUDISC) && ro && ro->ro_rt && 403 (ro->ro_rt->rt_locks & RTV_MTU) == 0) 404 ip->ip_off |= htons(IP_DF); 405 406 #ifdef IPSEC 407 /* 408 * Check if the packet needs encapsulation. 409 */ 410 if (tdb != NULL) { 411 /* Callee frees mbuf */ 412 error = ip_output_ipsec_send(tdb, m, ro, 413 (flags & IP_FORWARDING) ? 1 : 0); 414 goto done; 415 } 416 #endif /* IPSEC */ 417 418 /* 419 * Packet filter 420 */ 421 #if NPF > 0 422 if (pf_test(AF_INET, (flags & IP_FORWARDING) ? PF_FWD : PF_OUT, 423 ifp, &m) != PF_PASS) { 424 error = EACCES; 425 m_freem(m); 426 goto done; 427 } 428 if (m == NULL) 429 goto done; 430 ip = mtod(m, struct ip *); 431 hlen = ip->ip_hl << 2; 432 if ((m->m_pkthdr.pf.flags & (PF_TAG_REROUTE | PF_TAG_GENERATED)) == 433 (PF_TAG_REROUTE | PF_TAG_GENERATED)) 434 /* already rerun the route lookup, go on */ 435 m->m_pkthdr.pf.flags &= ~(PF_TAG_GENERATED | PF_TAG_REROUTE); 436 else if (m->m_pkthdr.pf.flags & PF_TAG_REROUTE) { 437 /* tag as generated to skip over pf_test on rerun */ 438 m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 439 ro = NULL; 440 if_put(ifp); /* drop reference since target changed */ 441 ifp = NULL; 442 goto reroute; 443 } 444 #endif 445 in_proto_cksum_out(m, ifp); 446 447 #ifdef IPSEC 448 if (ipsec_in_use && (flags & IP_FORWARDING) && (ipforwarding == 2) && 449 (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) == NULL)) { 450 error = EHOSTUNREACH; 451 m_freem(m); 452 goto done; 453 } 454 #endif 455 456 /* 457 * If small enough for interface, can just send directly. 458 */ 459 if (ntohs(ip->ip_len) <= mtu) { 460 ip->ip_sum = 0; 461 if ((ifp->if_capabilities & IFCAP_CSUM_IPv4) && 462 (ifp->if_bridgeidx == 0)) 463 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 464 else { 465 ipstat_inc(ips_outswcsum); 466 ip->ip_sum = in_cksum(m, hlen); 467 } 468 469 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 470 goto done; 471 } 472 473 /* 474 * Too large for interface; fragment if possible. 475 * Must be able to put at least 8 bytes per fragment. 476 */ 477 if (ip->ip_off & htons(IP_DF)) { 478 #ifdef IPSEC 479 if (ip_mtudisc) 480 ipsec_adjust_mtu(m, ifp->if_mtu); 481 #endif 482 error = EMSGSIZE; 483 /* 484 * This case can happen if the user changed the MTU 485 * of an interface after enabling IP on it. Because 486 * most netifs don't keep track of routes pointing to 487 * them, there is no way for one to update all its 488 * routes when the MTU is changed. 489 */ 490 if (rtisvalid(ro->ro_rt) && 491 ISSET(ro->ro_rt->rt_flags, RTF_HOST) && 492 !(ro->ro_rt->rt_locks & RTV_MTU) && 493 (ro->ro_rt->rt_mtu > ifp->if_mtu)) { 494 ro->ro_rt->rt_mtu = ifp->if_mtu; 495 } 496 ipstat_inc(ips_cantfrag); 497 goto bad; 498 } 499 500 error = ip_fragment(m, ifp, mtu); 501 if (error) { 502 m = m0 = NULL; 503 goto bad; 504 } 505 506 for (; m; m = m0) { 507 m0 = m->m_nextpkt; 508 m->m_nextpkt = 0; 509 if (error == 0) 510 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 511 else 512 m_freem(m); 513 } 514 515 if (error == 0) 516 ipstat_inc(ips_fragmented); 517 518 done: 519 if (ro == &iproute && ro->ro_rt) 520 rtfree(ro->ro_rt); 521 if_put(ifp); 522 return (error); 523 bad: 524 m_freem(m0); 525 goto done; 526 } 527 528 #ifdef IPSEC 529 struct tdb * 530 ip_output_ipsec_lookup(struct mbuf *m, int hlen, int *error, struct inpcb *inp, 531 int ipsecflowinfo) 532 { 533 struct m_tag *mtag; 534 struct tdb_ident *tdbi; 535 struct tdb *tdb; 536 537 /* Do we have any pending SAs to apply ? */ 538 tdb = ipsp_spd_lookup(m, AF_INET, hlen, error, IPSP_DIRECTION_OUT, 539 NULL, inp, ipsecflowinfo); 540 if (tdb == NULL) 541 return NULL; 542 /* Loop detection */ 543 for (mtag = m_tag_first(m); mtag != NULL; mtag = m_tag_next(m, mtag)) { 544 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE) 545 continue; 546 tdbi = (struct tdb_ident *)(mtag + 1); 547 if (tdbi->spi == tdb->tdb_spi && 548 tdbi->proto == tdb->tdb_sproto && 549 tdbi->rdomain == tdb->tdb_rdomain && 550 !memcmp(&tdbi->dst, &tdb->tdb_dst, 551 sizeof(union sockaddr_union))) { 552 /* no IPsec needed */ 553 return NULL; 554 } 555 } 556 return tdb; 557 } 558 559 int 560 ip_output_ipsec_send(struct tdb *tdb, struct mbuf *m, struct route *ro, int fwd) 561 { 562 #if NPF > 0 563 struct ifnet *encif; 564 #endif 565 struct ip *ip; 566 int error; 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 > gettime()) { 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, 1); 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 error = ipsp_process_packet(m, tdb, AF_INET, 0); 637 if (error) { 638 ipsecstat_inc(ipsec_odrops); 639 tdb->tdb_odrops++; 640 } 641 return error; 642 } 643 #endif /* IPSEC */ 644 645 int 646 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 647 { 648 struct ip *ip, *mhip; 649 struct mbuf *m0; 650 int len, hlen, off; 651 int mhlen, firstlen; 652 struct mbuf **mnext; 653 int fragments = 0; 654 int error = 0; 655 656 ip = mtod(m, struct ip *); 657 hlen = ip->ip_hl << 2; 658 659 len = (mtu - hlen) &~ 7; 660 if (len < 8) { 661 m_freem(m); 662 return (EMSGSIZE); 663 } 664 665 /* 666 * If we are doing fragmentation, we can't defer TCP/UDP 667 * checksumming; compute the checksum and clear the flag. 668 */ 669 in_proto_cksum_out(m, NULL); 670 firstlen = len; 671 mnext = &m->m_nextpkt; 672 673 /* 674 * Loop through length of segment after first fragment, 675 * make new header and copy data of each part and link onto chain. 676 */ 677 m0 = m; 678 mhlen = sizeof (struct ip); 679 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 680 MGETHDR(m, M_DONTWAIT, MT_HEADER); 681 if (m == NULL) { 682 ipstat_inc(ips_odropped); 683 error = ENOBUFS; 684 goto sendorfree; 685 } 686 *mnext = m; 687 mnext = &m->m_nextpkt; 688 m->m_data += max_linkhdr; 689 mhip = mtod(m, struct ip *); 690 *mhip = *ip; 691 /* we must inherit MCAST/BCAST flags, routing table and prio */ 692 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 693 m->m_pkthdr.ph_rtableid = m0->m_pkthdr.ph_rtableid; 694 m->m_pkthdr.pf.prio = m0->m_pkthdr.pf.prio; 695 if (hlen > sizeof (struct ip)) { 696 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 697 mhip->ip_hl = mhlen >> 2; 698 } 699 m->m_len = mhlen; 700 mhip->ip_off = ((off - hlen) >> 3) + 701 (ntohs(ip->ip_off) & ~IP_MF); 702 if (ip->ip_off & htons(IP_MF)) 703 mhip->ip_off |= IP_MF; 704 if (off + len >= ntohs(ip->ip_len)) 705 len = ntohs(ip->ip_len) - off; 706 else 707 mhip->ip_off |= IP_MF; 708 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 709 m->m_next = m_copym(m0, off, len, M_NOWAIT); 710 if (m->m_next == 0) { 711 ipstat_inc(ips_odropped); 712 error = ENOBUFS; 713 goto sendorfree; 714 } 715 m->m_pkthdr.len = mhlen + len; 716 m->m_pkthdr.ph_ifidx = 0; 717 mhip->ip_off = htons((u_int16_t)mhip->ip_off); 718 mhip->ip_sum = 0; 719 if ((ifp != NULL) && 720 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 721 (ifp->if_bridgeidx == 0)) 722 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 723 else { 724 ipstat_inc(ips_outswcsum); 725 mhip->ip_sum = in_cksum(m, mhlen); 726 } 727 ipstat_inc(ips_ofragments); 728 fragments++; 729 } 730 /* 731 * Update first fragment by trimming what's been copied out 732 * and updating header, then send each fragment (in order). 733 */ 734 m = m0; 735 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 736 m->m_pkthdr.len = hlen + firstlen; 737 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 738 ip->ip_off |= htons(IP_MF); 739 ip->ip_sum = 0; 740 if ((ifp != NULL) && 741 (ifp->if_capabilities & IFCAP_CSUM_IPv4) && 742 (ifp->if_bridgeidx == 0)) 743 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 744 else { 745 ipstat_inc(ips_outswcsum); 746 ip->ip_sum = in_cksum(m, hlen); 747 } 748 sendorfree: 749 if (error) { 750 for (m = m0; m; m = m0) { 751 m0 = m->m_nextpkt; 752 m->m_nextpkt = NULL; 753 m_freem(m); 754 } 755 } 756 757 return (error); 758 } 759 760 /* 761 * Insert IP options into preformed packet. 762 * Adjust IP destination as required for IP source routing, 763 * as indicated by a non-zero in_addr at the start of the options. 764 */ 765 struct mbuf * 766 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 767 { 768 struct ipoption *p = mtod(opt, struct ipoption *); 769 struct mbuf *n; 770 struct ip *ip = mtod(m, struct ip *); 771 unsigned int optlen; 772 773 optlen = opt->m_len - sizeof(p->ipopt_dst); 774 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 775 return (m); /* XXX should fail */ 776 if (p->ipopt_dst.s_addr) 777 ip->ip_dst = p->ipopt_dst; 778 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 779 MGETHDR(n, M_DONTWAIT, MT_HEADER); 780 if (n == NULL) 781 return (m); 782 M_MOVE_HDR(n, m); 783 n->m_pkthdr.len += optlen; 784 m->m_len -= sizeof(struct ip); 785 m->m_data += sizeof(struct ip); 786 n->m_next = m; 787 m = n; 788 m->m_len = optlen + sizeof(struct ip); 789 m->m_data += max_linkhdr; 790 memcpy(mtod(m, caddr_t), ip, sizeof(struct ip)); 791 } else { 792 m->m_data -= optlen; 793 m->m_len += optlen; 794 m->m_pkthdr.len += optlen; 795 memmove(mtod(m, caddr_t), (caddr_t)ip, sizeof(struct ip)); 796 } 797 ip = mtod(m, struct ip *); 798 memcpy(ip + 1, p->ipopt_list, optlen); 799 *phlen = sizeof(struct ip) + optlen; 800 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 801 return (m); 802 } 803 804 /* 805 * Copy options from ip to jp, 806 * omitting those not copied during fragmentation. 807 */ 808 int 809 ip_optcopy(struct ip *ip, struct ip *jp) 810 { 811 u_char *cp, *dp; 812 int opt, optlen, cnt; 813 814 cp = (u_char *)(ip + 1); 815 dp = (u_char *)(jp + 1); 816 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 817 for (; cnt > 0; cnt -= optlen, cp += optlen) { 818 opt = cp[0]; 819 if (opt == IPOPT_EOL) 820 break; 821 if (opt == IPOPT_NOP) { 822 /* Preserve for IP mcast tunnel's LSRR alignment. */ 823 *dp++ = IPOPT_NOP; 824 optlen = 1; 825 continue; 826 } 827 #ifdef DIAGNOSTIC 828 if (cnt < IPOPT_OLEN + sizeof(*cp)) 829 panic("malformed IPv4 option passed to ip_optcopy"); 830 #endif 831 optlen = cp[IPOPT_OLEN]; 832 #ifdef DIAGNOSTIC 833 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 834 panic("malformed IPv4 option passed to ip_optcopy"); 835 #endif 836 /* bogus lengths should have been caught by ip_dooptions */ 837 if (optlen > cnt) 838 optlen = cnt; 839 if (IPOPT_COPIED(opt)) { 840 memcpy(dp, cp, optlen); 841 dp += optlen; 842 } 843 } 844 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 845 *dp++ = IPOPT_EOL; 846 return (optlen); 847 } 848 849 /* 850 * IP socket option processing. 851 */ 852 int 853 ip_ctloutput(int op, struct socket *so, int level, int optname, 854 struct mbuf *m) 855 { 856 struct inpcb *inp = sotoinpcb(so); 857 int optval = 0; 858 struct proc *p = curproc; /* XXX */ 859 int error = 0; 860 u_int rtid = 0; 861 862 if (level != IPPROTO_IP) 863 return (EINVAL); 864 865 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 struct mbuf *n; 1237 struct ipoption *p; 1238 int cnt, off, optlen; 1239 u_char *cp; 1240 u_char opt; 1241 1242 /* turn off any old options */ 1243 m_freem(*pcbopt); 1244 *pcbopt = NULL; 1245 if (m == NULL || m->m_len == 0) { 1246 /* 1247 * Only turning off any previous options. 1248 */ 1249 return (0); 1250 } 1251 1252 if (m->m_len % sizeof(int32_t) || 1253 m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1254 return (EINVAL); 1255 1256 /* Don't sleep because NET_LOCK() is hold. */ 1257 if ((n = m_get(M_NOWAIT, MT_SOOPTS)) == NULL) 1258 return (ENOBUFS); 1259 p = mtod(n, struct ipoption *); 1260 memset(p, 0, sizeof (*p)); /* 0 = IPOPT_EOL, needed for padding */ 1261 n->m_len = sizeof(struct in_addr); 1262 1263 off = 0; 1264 cnt = m->m_len; 1265 cp = mtod(m, u_char *); 1266 1267 while (cnt > 0) { 1268 opt = cp[IPOPT_OPTVAL]; 1269 1270 if (opt == IPOPT_NOP || opt == IPOPT_EOL) { 1271 optlen = 1; 1272 } else { 1273 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1274 goto bad; 1275 optlen = cp[IPOPT_OLEN]; 1276 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1277 goto bad; 1278 } 1279 switch (opt) { 1280 default: 1281 memcpy(p->ipopt_list + off, cp, optlen); 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 goto bad; 1296 1297 /* 1298 * Optlen is smaller because first address is popped. 1299 * Cnt and cp will be adjusted a bit later to reflect 1300 * this. 1301 */ 1302 optlen -= sizeof(struct in_addr); 1303 p->ipopt_list[off + IPOPT_OPTVAL] = opt; 1304 p->ipopt_list[off + IPOPT_OLEN] = optlen; 1305 1306 /* 1307 * Move first hop before start of options. 1308 */ 1309 memcpy(&p->ipopt_dst, cp + IPOPT_OFFSET, 1310 sizeof(struct in_addr)); 1311 cp += sizeof(struct in_addr); 1312 cnt -= sizeof(struct in_addr); 1313 /* 1314 * Then copy rest of options 1315 */ 1316 memcpy(p->ipopt_list + off + IPOPT_OFFSET, 1317 cp + IPOPT_OFFSET, optlen - IPOPT_OFFSET); 1318 break; 1319 } 1320 off += optlen; 1321 cp += optlen; 1322 cnt -= optlen; 1323 1324 if (opt == IPOPT_EOL) 1325 break; 1326 } 1327 /* pad options to next word, since p was zeroed just adjust off */ 1328 off = (off + sizeof(int32_t) - 1) & ~(sizeof(int32_t) - 1); 1329 n->m_len += off; 1330 if (n->m_len > sizeof(*p)) { 1331 bad: 1332 m_freem(n); 1333 return (EINVAL); 1334 } 1335 1336 *pcbopt = n; 1337 return (0); 1338 } 1339 1340 /* 1341 * Lookup the interface based on the information in the ip_mreqn struct. 1342 */ 1343 int 1344 ip_multicast_if(struct ip_mreqn *mreq, u_int rtableid, unsigned int *ifidx) 1345 { 1346 struct sockaddr_in sin; 1347 struct rtentry *rt; 1348 1349 /* 1350 * In case userland provides the imr_ifindex use this as interface. 1351 * If no interface address was provided, use the interface of 1352 * the route to the given multicast address. 1353 */ 1354 if (mreq->imr_ifindex != 0) { 1355 *ifidx = mreq->imr_ifindex; 1356 } else if (mreq->imr_address.s_addr == INADDR_ANY) { 1357 memset(&sin, 0, sizeof(sin)); 1358 sin.sin_len = sizeof(sin); 1359 sin.sin_family = AF_INET; 1360 sin.sin_addr = mreq->imr_multiaddr; 1361 rt = rtalloc(sintosa(&sin), RT_RESOLVE, rtableid); 1362 if (!rtisvalid(rt)) { 1363 rtfree(rt); 1364 return EADDRNOTAVAIL; 1365 } 1366 *ifidx = rt->rt_ifidx; 1367 rtfree(rt); 1368 } else { 1369 memset(&sin, 0, sizeof(sin)); 1370 sin.sin_len = sizeof(sin); 1371 sin.sin_family = AF_INET; 1372 sin.sin_addr = mreq->imr_address; 1373 rt = rtalloc(sintosa(&sin), 0, rtableid); 1374 if (!rtisvalid(rt) || !ISSET(rt->rt_flags, RTF_LOCAL)) { 1375 rtfree(rt); 1376 return EADDRNOTAVAIL; 1377 } 1378 *ifidx = rt->rt_ifidx; 1379 rtfree(rt); 1380 } 1381 1382 return 0; 1383 } 1384 1385 /* 1386 * Set the IP multicast options in response to user setsockopt(). 1387 */ 1388 int 1389 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m, 1390 u_int rtableid) 1391 { 1392 struct in_addr addr; 1393 struct in_ifaddr *ia; 1394 struct ip_mreqn mreqn; 1395 struct ifnet *ifp = NULL; 1396 struct ip_moptions *imo = *imop; 1397 struct in_multi **immp; 1398 struct sockaddr_in sin; 1399 unsigned int ifidx; 1400 int i, error = 0; 1401 u_char loop; 1402 1403 if (imo == NULL) { 1404 /* 1405 * No multicast option buffer attached to the pcb; 1406 * allocate one and initialize to default values. 1407 */ 1408 imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK|M_ZERO); 1409 immp = mallocarray(IP_MIN_MEMBERSHIPS, sizeof(*immp), M_IPMOPTS, 1410 M_WAITOK|M_ZERO); 1411 *imop = imo; 1412 imo->imo_ifidx = 0; 1413 imo->imo_ttl = IP_DEFAULT_MULTICAST_TTL; 1414 imo->imo_loop = IP_DEFAULT_MULTICAST_LOOP; 1415 imo->imo_num_memberships = 0; 1416 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; 1417 imo->imo_membership = immp; 1418 } 1419 1420 switch (optname) { 1421 1422 case IP_MULTICAST_IF: 1423 /* 1424 * Select the interface for outgoing multicast packets. 1425 */ 1426 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1427 error = EINVAL; 1428 break; 1429 } 1430 addr = *(mtod(m, struct in_addr *)); 1431 /* 1432 * INADDR_ANY is used to remove a previous selection. 1433 * When no interface is selected, a default one is 1434 * chosen every time a multicast packet is sent. 1435 */ 1436 if (addr.s_addr == INADDR_ANY) { 1437 imo->imo_ifidx = 0; 1438 break; 1439 } 1440 /* 1441 * The selected interface is identified by its local 1442 * IP address. Find the interface and confirm that 1443 * it supports multicasting. 1444 */ 1445 memset(&sin, 0, sizeof(sin)); 1446 sin.sin_len = sizeof(sin); 1447 sin.sin_family = AF_INET; 1448 sin.sin_addr = addr; 1449 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1450 if (ia == NULL || 1451 (ia->ia_ifp->if_flags & IFF_MULTICAST) == 0) { 1452 error = EADDRNOTAVAIL; 1453 break; 1454 } 1455 imo->imo_ifidx = ia->ia_ifp->if_index; 1456 break; 1457 1458 case IP_MULTICAST_TTL: 1459 /* 1460 * Set the IP time-to-live for outgoing multicast packets. 1461 */ 1462 if (m == NULL || m->m_len != 1) { 1463 error = EINVAL; 1464 break; 1465 } 1466 imo->imo_ttl = *(mtod(m, u_char *)); 1467 break; 1468 1469 case IP_MULTICAST_LOOP: 1470 /* 1471 * Set the loopback flag for outgoing multicast packets. 1472 * Must be zero or one. 1473 */ 1474 if (m == NULL || m->m_len != 1 || 1475 (loop = *(mtod(m, u_char *))) > 1) { 1476 error = EINVAL; 1477 break; 1478 } 1479 imo->imo_loop = loop; 1480 break; 1481 1482 case IP_ADD_MEMBERSHIP: 1483 /* 1484 * Add a multicast group membership. 1485 * Group must be a valid IP multicast address. 1486 */ 1487 if (m == NULL || !(m->m_len == sizeof(struct ip_mreq) || 1488 m->m_len == sizeof(struct ip_mreqn))) { 1489 error = EINVAL; 1490 break; 1491 } 1492 memset(&mreqn, 0, sizeof(mreqn)); 1493 memcpy(&mreqn, mtod(m, void *), m->m_len); 1494 if (!IN_MULTICAST(mreqn.imr_multiaddr.s_addr)) { 1495 error = EINVAL; 1496 break; 1497 } 1498 1499 error = ip_multicast_if(&mreqn, rtableid, &ifidx); 1500 if (error) 1501 break; 1502 1503 /* 1504 * See if we found an interface, and confirm that it 1505 * supports multicast. 1506 */ 1507 ifp = if_get(ifidx); 1508 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1509 error = EADDRNOTAVAIL; 1510 if_put(ifp); 1511 break; 1512 } 1513 1514 /* 1515 * See if the membership already exists or if all the 1516 * membership slots are full. 1517 */ 1518 for (i = 0; i < imo->imo_num_memberships; ++i) { 1519 if (imo->imo_membership[i]->inm_ifidx == ifidx && 1520 imo->imo_membership[i]->inm_addr.s_addr 1521 == mreqn.imr_multiaddr.s_addr) 1522 break; 1523 } 1524 if (i < imo->imo_num_memberships) { 1525 error = EADDRINUSE; 1526 if_put(ifp); 1527 break; 1528 } 1529 if (imo->imo_num_memberships == imo->imo_max_memberships) { 1530 struct in_multi **nmships, **omships; 1531 size_t newmax; 1532 /* 1533 * Resize the vector to next power-of-two minus 1. If 1534 * the size would exceed the maximum then we know we've 1535 * really run out of entries. Otherwise, we reallocate 1536 * the vector. 1537 */ 1538 nmships = NULL; 1539 omships = imo->imo_membership; 1540 newmax = ((imo->imo_max_memberships + 1) * 2) - 1; 1541 if (newmax <= IP_MAX_MEMBERSHIPS) { 1542 nmships = mallocarray(newmax, sizeof(*nmships), 1543 M_IPMOPTS, M_NOWAIT|M_ZERO); 1544 if (nmships != NULL) { 1545 memcpy(nmships, omships, 1546 sizeof(*omships) * 1547 imo->imo_max_memberships); 1548 free(omships, M_IPMOPTS, 1549 sizeof(*omships) * 1550 imo->imo_max_memberships); 1551 imo->imo_membership = nmships; 1552 imo->imo_max_memberships = newmax; 1553 } 1554 } 1555 if (nmships == NULL) { 1556 error = ENOBUFS; 1557 if_put(ifp); 1558 break; 1559 } 1560 } 1561 /* 1562 * Everything looks good; add a new record to the multicast 1563 * address list for the given interface. 1564 */ 1565 if ((imo->imo_membership[i] = 1566 in_addmulti(&mreqn.imr_multiaddr, ifp)) == NULL) { 1567 error = ENOBUFS; 1568 if_put(ifp); 1569 break; 1570 } 1571 ++imo->imo_num_memberships; 1572 if_put(ifp); 1573 break; 1574 1575 case IP_DROP_MEMBERSHIP: 1576 /* 1577 * Drop a multicast group membership. 1578 * Group must be a valid IP multicast address. 1579 */ 1580 if (m == NULL || !(m->m_len == sizeof(struct ip_mreq) || 1581 m->m_len == sizeof(struct ip_mreqn))) { 1582 error = EINVAL; 1583 break; 1584 } 1585 memset(&mreqn, 0, sizeof(mreqn)); 1586 memcpy(&mreqn, mtod(m, void *), m->m_len); 1587 if (!IN_MULTICAST(mreqn.imr_multiaddr.s_addr)) { 1588 error = EINVAL; 1589 break; 1590 } 1591 1592 /* 1593 * If an interface address was specified, get a pointer 1594 * to its ifnet structure. 1595 */ 1596 error = ip_multicast_if(&mreqn, rtableid, &ifidx); 1597 if (error) 1598 break; 1599 1600 /* 1601 * Find the membership in the membership array. 1602 */ 1603 for (i = 0; i < imo->imo_num_memberships; ++i) { 1604 if ((ifidx == 0 || 1605 imo->imo_membership[i]->inm_ifidx == ifidx) && 1606 imo->imo_membership[i]->inm_addr.s_addr == 1607 mreqn.imr_multiaddr.s_addr) 1608 break; 1609 } 1610 if (i == imo->imo_num_memberships) { 1611 error = EADDRNOTAVAIL; 1612 break; 1613 } 1614 /* 1615 * Give up the multicast address record to which the 1616 * membership points. 1617 */ 1618 in_delmulti(imo->imo_membership[i]); 1619 /* 1620 * Remove the gap in the membership array. 1621 */ 1622 for (++i; i < imo->imo_num_memberships; ++i) 1623 imo->imo_membership[i-1] = imo->imo_membership[i]; 1624 --imo->imo_num_memberships; 1625 break; 1626 1627 default: 1628 error = EOPNOTSUPP; 1629 break; 1630 } 1631 1632 /* 1633 * If all options have default values, no need to keep the data. 1634 */ 1635 if (imo->imo_ifidx == 0 && 1636 imo->imo_ttl == IP_DEFAULT_MULTICAST_TTL && 1637 imo->imo_loop == IP_DEFAULT_MULTICAST_LOOP && 1638 imo->imo_num_memberships == 0) { 1639 free(imo->imo_membership , M_IPMOPTS, 1640 imo->imo_max_memberships * sizeof(struct in_multi *)); 1641 free(*imop, M_IPMOPTS, sizeof(**imop)); 1642 *imop = NULL; 1643 } 1644 1645 return (error); 1646 } 1647 1648 /* 1649 * Return the IP multicast options in response to user getsockopt(). 1650 */ 1651 int 1652 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf *m) 1653 { 1654 u_char *ttl; 1655 u_char *loop; 1656 struct in_addr *addr; 1657 struct in_ifaddr *ia; 1658 struct ifnet *ifp; 1659 1660 switch (optname) { 1661 1662 case IP_MULTICAST_IF: 1663 addr = mtod(m, struct in_addr *); 1664 m->m_len = sizeof(struct in_addr); 1665 if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL) 1666 addr->s_addr = INADDR_ANY; 1667 else { 1668 IFP_TO_IA(ifp, ia); 1669 if_put(ifp); 1670 addr->s_addr = (ia == NULL) ? INADDR_ANY 1671 : ia->ia_addr.sin_addr.s_addr; 1672 } 1673 return (0); 1674 1675 case IP_MULTICAST_TTL: 1676 ttl = mtod(m, u_char *); 1677 m->m_len = 1; 1678 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1679 : imo->imo_ttl; 1680 return (0); 1681 1682 case IP_MULTICAST_LOOP: 1683 loop = mtod(m, u_char *); 1684 m->m_len = 1; 1685 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1686 : imo->imo_loop; 1687 return (0); 1688 1689 default: 1690 return (EOPNOTSUPP); 1691 } 1692 } 1693 1694 /* 1695 * Discard the IP multicast options. 1696 */ 1697 void 1698 ip_freemoptions(struct ip_moptions *imo) 1699 { 1700 int i; 1701 1702 if (imo != NULL) { 1703 for (i = 0; i < imo->imo_num_memberships; ++i) 1704 in_delmulti(imo->imo_membership[i]); 1705 free(imo->imo_membership, M_IPMOPTS, 1706 imo->imo_max_memberships * sizeof(struct in_multi *)); 1707 free(imo, M_IPMOPTS, sizeof(*imo)); 1708 } 1709 } 1710 1711 /* 1712 * Routine called from ip_output() to loop back a copy of an IP multicast 1713 * packet to the input queue of a specified interface. 1714 */ 1715 void 1716 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1717 { 1718 struct ip *ip; 1719 struct mbuf *copym; 1720 1721 copym = m_dup_pkt(m, max_linkhdr, M_DONTWAIT); 1722 if (copym != NULL) { 1723 /* 1724 * We don't bother to fragment if the IP length is greater 1725 * than the interface's MTU. Can this possibly matter? 1726 */ 1727 ip = mtod(copym, struct ip *); 1728 ip->ip_sum = 0; 1729 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1730 if_input_local(ifp, copym, dst->sin_family); 1731 } 1732 } 1733 1734 /* 1735 * Compute significant parts of the IPv4 checksum pseudo-header 1736 * for use in a delayed TCP/UDP checksum calculation. 1737 */ 1738 static __inline u_int16_t __attribute__((__unused__)) 1739 in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) 1740 { 1741 u_int32_t sum; 1742 1743 sum = lenproto + 1744 (u_int16_t)(src >> 16) + 1745 (u_int16_t)(src /*& 0xffff*/) + 1746 (u_int16_t)(dst >> 16) + 1747 (u_int16_t)(dst /*& 0xffff*/); 1748 1749 sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); 1750 1751 if (sum > 0xffff) 1752 sum -= 0xffff; 1753 1754 return (sum); 1755 } 1756 1757 /* 1758 * Process a delayed payload checksum calculation. 1759 */ 1760 void 1761 in_delayed_cksum(struct mbuf *m) 1762 { 1763 struct ip *ip; 1764 u_int16_t csum, offset; 1765 1766 ip = mtod(m, struct ip *); 1767 offset = ip->ip_hl << 2; 1768 csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset); 1769 if (csum == 0 && ip->ip_p == IPPROTO_UDP) 1770 csum = 0xffff; 1771 1772 switch (ip->ip_p) { 1773 case IPPROTO_TCP: 1774 offset += offsetof(struct tcphdr, th_sum); 1775 break; 1776 1777 case IPPROTO_UDP: 1778 offset += offsetof(struct udphdr, uh_sum); 1779 break; 1780 1781 case IPPROTO_ICMP: 1782 offset += offsetof(struct icmp, icmp_cksum); 1783 break; 1784 1785 default: 1786 return; 1787 } 1788 1789 if ((offset + sizeof(u_int16_t)) > m->m_len) 1790 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1791 else 1792 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1793 } 1794 1795 void 1796 in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp) 1797 { 1798 struct ip *ip = mtod(m, struct ip *); 1799 1800 /* some hw and in_delayed_cksum need the pseudo header cksum */ 1801 if (m->m_pkthdr.csum_flags & 1802 (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT|M_ICMP_CSUM_OUT)) { 1803 u_int16_t csum = 0, offset; 1804 1805 offset = ip->ip_hl << 2; 1806 if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) 1807 csum = in_cksum_phdr(ip->ip_src.s_addr, 1808 ip->ip_dst.s_addr, htonl(ntohs(ip->ip_len) - 1809 offset + ip->ip_p)); 1810 if (ip->ip_p == IPPROTO_TCP) 1811 offset += offsetof(struct tcphdr, th_sum); 1812 else if (ip->ip_p == IPPROTO_UDP) 1813 offset += offsetof(struct udphdr, uh_sum); 1814 else if (ip->ip_p == IPPROTO_ICMP) 1815 offset += offsetof(struct icmp, icmp_cksum); 1816 if ((offset + sizeof(u_int16_t)) > m->m_len) 1817 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1818 else 1819 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1820 } 1821 1822 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) { 1823 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || 1824 ip->ip_hl != 5 || ifp->if_bridgeidx != 0) { 1825 tcpstat_inc(tcps_outswcsum); 1826 in_delayed_cksum(m); 1827 m->m_pkthdr.csum_flags &= ~M_TCP_CSUM_OUT; /* Clear */ 1828 } 1829 } else if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) { 1830 if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || 1831 ip->ip_hl != 5 || ifp->if_bridgeidx != 0) { 1832 udpstat_inc(udps_outswcsum); 1833 in_delayed_cksum(m); 1834 m->m_pkthdr.csum_flags &= ~M_UDP_CSUM_OUT; /* Clear */ 1835 } 1836 } else if (m->m_pkthdr.csum_flags & M_ICMP_CSUM_OUT) { 1837 in_delayed_cksum(m); 1838 m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */ 1839 } 1840 } 1841