1 /* $OpenBSD: ip_output.c,v 1.382 2022/08/12 17:04:16 bluhm Exp $ */ 2 /* $NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1988, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 33 */ 34 35 #include "pf.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/mbuf.h> 40 #include <sys/protosw.h> 41 #include <sys/socket.h> 42 #include <sys/socketvar.h> 43 #include <sys/proc.h> 44 #include <sys/kernel.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_enc.h> 49 #include <net/route.h> 50 51 #include <netinet/in.h> 52 #include <netinet/ip.h> 53 #include <netinet/in_pcb.h> 54 #include <netinet/in_var.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/ip_icmp.h> 57 #include <netinet/tcp.h> 58 #include <netinet/udp.h> 59 #include <netinet/tcp_timer.h> 60 #include <netinet/tcp_var.h> 61 #include <netinet/udp_var.h> 62 63 #if NPF > 0 64 #include <net/pfvar.h> 65 #endif 66 67 #ifdef IPSEC 68 #ifdef ENCDEBUG 69 #define DPRINTF(fmt, args...) \ 70 do { \ 71 if (encdebug) \ 72 printf("%s: " fmt "\n", __func__, ## args); \ 73 } while (0) 74 #else 75 #define DPRINTF(fmt, args...) \ 76 do { } while (0) 77 #endif 78 #endif /* IPSEC */ 79 80 int ip_pcbopts(struct mbuf **, struct mbuf *); 81 int ip_multicast_if(struct ip_mreqn *, u_int, unsigned int *); 82 int ip_setmoptions(int, struct ip_moptions **, struct mbuf *, u_int); 83 void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); 84 static __inline u_int16_t __attribute__((__unused__)) 85 in_cksum_phdr(u_int32_t, u_int32_t, u_int32_t); 86 void in_delayed_cksum(struct mbuf *); 87 int in_ifcap_cksum(struct mbuf *, struct ifnet *, int); 88 89 int ip_output_ipsec_lookup(struct mbuf *m, int hlen, struct inpcb *inp, 90 struct tdb **, int ipsecflowinfo); 91 void ip_output_ipsec_pmtu_update(struct tdb *, struct route *, struct in_addr, 92 int, int); 93 int ip_output_ipsec_send(struct tdb *, struct mbuf *, struct route *, int); 94 95 /* 96 * IP output. The packet in mbuf chain m contains a skeletal IP 97 * header (with len, off, ttl, proto, tos, src, dst). 98 * The mbuf chain containing the packet will be freed. 99 * The mbuf opt, if present, will not be freed. 100 */ 101 int 102 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, 103 struct ip_moptions *imo, struct inpcb *inp, u_int32_t ipsecflowinfo) 104 { 105 struct ip *ip; 106 struct ifnet *ifp = NULL; 107 struct mbuf_list fml; 108 int hlen = sizeof (struct ip); 109 int error = 0; 110 struct route iproute; 111 struct sockaddr_in *dst; 112 struct tdb *tdb = NULL; 113 u_long mtu; 114 #if NPF > 0 115 u_int orig_rtableid; 116 #endif 117 118 NET_ASSERT_LOCKED(); 119 120 #ifdef IPSEC 121 if (inp && (inp->inp_flags & INP_IPV6) != 0) 122 panic("ip_output: IPv6 pcb is passed"); 123 #endif /* IPSEC */ 124 125 #ifdef DIAGNOSTIC 126 if ((m->m_flags & M_PKTHDR) == 0) 127 panic("ip_output no HDR"); 128 #endif 129 if (opt) 130 m = ip_insertoptions(m, opt, &hlen); 131 132 ip = mtod(m, struct ip *); 133 134 /* 135 * Fill in IP header. 136 */ 137 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 138 ip->ip_v = IPVERSION; 139 ip->ip_off &= htons(IP_DF); 140 ip->ip_id = htons(ip_randomid()); 141 ip->ip_hl = hlen >> 2; 142 ipstat_inc(ips_localout); 143 } else { 144 hlen = ip->ip_hl << 2; 145 } 146 147 /* 148 * We should not send traffic to 0/8 say both Stevens and RFCs 149 * 5735 section 3 and 1122 sections 3.2.1.3 and 3.3.6. 150 */ 151 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == 0) { 152 error = ENETUNREACH; 153 goto bad; 154 } 155 156 #if NPF > 0 157 orig_rtableid = m->m_pkthdr.ph_rtableid; 158 reroute: 159 #endif 160 161 /* 162 * Do a route lookup now in case we need the source address to 163 * do an SPD lookup in IPsec; for most packets, the source address 164 * is set at a higher level protocol. ICMPs and other packets 165 * though (e.g., traceroute) have a source address of zeroes. 166 */ 167 if (ro == NULL) { 168 ro = &iproute; 169 memset(ro, 0, sizeof(*ro)); 170 } 171 172 dst = satosin(&ro->ro_dst); 173 174 /* 175 * If there is a cached route, check that it is to the same 176 * destination and is still up. If not, free it and try again. 177 */ 178 if (!rtisvalid(ro->ro_rt) || 179 dst->sin_addr.s_addr != ip->ip_dst.s_addr || 180 ro->ro_tableid != m->m_pkthdr.ph_rtableid) { 181 rtfree(ro->ro_rt); 182 ro->ro_rt = NULL; 183 } 184 185 if (ro->ro_rt == NULL) { 186 dst->sin_family = AF_INET; 187 dst->sin_len = sizeof(*dst); 188 dst->sin_addr = ip->ip_dst; 189 ro->ro_tableid = m->m_pkthdr.ph_rtableid; 190 } 191 192 if ((IN_MULTICAST(ip->ip_dst.s_addr) || 193 (ip->ip_dst.s_addr == INADDR_BROADCAST)) && 194 imo != NULL && (ifp = if_get(imo->imo_ifidx)) != NULL) { 195 196 mtu = ifp->if_mtu; 197 if (ip->ip_src.s_addr == INADDR_ANY) { 198 struct in_ifaddr *ia; 199 200 IFP_TO_IA(ifp, ia); 201 if (ia != NULL) 202 ip->ip_src = ia->ia_addr.sin_addr; 203 } 204 } else { 205 struct in_ifaddr *ia; 206 207 if (ro->ro_rt == NULL) 208 ro->ro_rt = rtalloc_mpath(&ro->ro_dst, 209 &ip->ip_src.s_addr, ro->ro_tableid); 210 211 if (ro->ro_rt == NULL) { 212 ipstat_inc(ips_noroute); 213 error = EHOSTUNREACH; 214 goto bad; 215 } 216 217 ia = ifatoia(ro->ro_rt->rt_ifa); 218 if (ISSET(ro->ro_rt->rt_flags, RTF_LOCAL)) 219 ifp = if_get(rtable_loindex(m->m_pkthdr.ph_rtableid)); 220 else 221 ifp = if_get(ro->ro_rt->rt_ifidx); 222 /* 223 * We aren't using rtisvalid() here because the UP/DOWN state 224 * machine is broken with some Ethernet drivers like em(4). 225 * As a result we might try to use an invalid cached route 226 * entry while an interface is being detached. 227 */ 228 if (ifp == NULL) { 229 ipstat_inc(ips_noroute); 230 error = EHOSTUNREACH; 231 goto bad; 232 } 233 if ((mtu = ro->ro_rt->rt_mtu) == 0) 234 mtu = ifp->if_mtu; 235 236 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 237 dst = satosin(ro->ro_rt->rt_gateway); 238 239 /* Set the source IP address */ 240 if (ip->ip_src.s_addr == INADDR_ANY && ia) 241 ip->ip_src = ia->ia_addr.sin_addr; 242 } 243 244 #ifdef IPSEC 245 if (ipsec_in_use || inp != NULL) { 246 /* Do we have any pending SAs to apply ? */ 247 error = ip_output_ipsec_lookup(m, hlen, inp, &tdb, 248 ipsecflowinfo); 249 if (error) { 250 /* Should silently drop packet */ 251 if (error == -EINVAL) 252 error = 0; 253 goto bad; 254 } 255 if (tdb != NULL) { 256 /* 257 * If it needs TCP/UDP hardware-checksumming, do the 258 * computation now. 259 */ 260 in_proto_cksum_out(m, NULL); 261 } 262 } 263 #endif /* IPSEC */ 264 265 if (IN_MULTICAST(ip->ip_dst.s_addr) || 266 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 267 268 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 269 M_BCAST : M_MCAST; 270 271 /* 272 * IP destination address is multicast. Make sure "dst" 273 * still points to the address in "ro". (It may have been 274 * changed to point to a gateway address, above.) 275 */ 276 dst = satosin(&ro->ro_dst); 277 278 /* 279 * See if the caller provided any multicast options 280 */ 281 if (imo != NULL) 282 ip->ip_ttl = imo->imo_ttl; 283 else 284 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 285 286 /* 287 * if we don't know the outgoing ifp yet, we can't generate 288 * output 289 */ 290 if (!ifp) { 291 ipstat_inc(ips_noroute); 292 error = EHOSTUNREACH; 293 goto bad; 294 } 295 296 /* 297 * Confirm that the outgoing interface supports multicast, 298 * but only if the packet actually is going out on that 299 * interface (i.e., no IPsec is applied). 300 */ 301 if ((((m->m_flags & M_MCAST) && 302 (ifp->if_flags & IFF_MULTICAST) == 0) || 303 ((m->m_flags & M_BCAST) && 304 (ifp->if_flags & IFF_BROADCAST) == 0)) && (tdb == NULL)) { 305 ipstat_inc(ips_noroute); 306 error = ENETUNREACH; 307 goto bad; 308 } 309 310 /* 311 * If source address not specified yet, use address 312 * of outgoing interface. 313 */ 314 if (ip->ip_src.s_addr == INADDR_ANY) { 315 struct in_ifaddr *ia; 316 317 IFP_TO_IA(ifp, ia); 318 if (ia != NULL) 319 ip->ip_src = ia->ia_addr.sin_addr; 320 } 321 322 if ((imo == NULL || imo->imo_loop) && 323 in_hasmulti(&ip->ip_dst, ifp)) { 324 /* 325 * If we belong to the destination multicast group 326 * on the outgoing interface, and the caller did not 327 * forbid loopback, loop back a copy. 328 * Can't defer TCP/UDP checksumming, do the 329 * computation now. 330 */ 331 in_proto_cksum_out(m, NULL); 332 ip_mloopback(ifp, m, dst); 333 } 334 #ifdef MROUTING 335 else { 336 /* 337 * If we are acting as a multicast router, perform 338 * multicast forwarding as if the packet had just 339 * arrived on the interface to which we are about 340 * to send. The multicast forwarding function 341 * recursively calls this function, using the 342 * IP_FORWARDING flag to prevent infinite recursion. 343 * 344 * Multicasts that are looped back by ip_mloopback(), 345 * above, will be forwarded by the ip_input() routine, 346 * if necessary. 347 */ 348 if (ipmforwarding && ip_mrouter[ifp->if_rdomain] && 349 (flags & IP_FORWARDING) == 0) { 350 int rv; 351 352 KERNEL_LOCK(); 353 rv = ip_mforward(m, ifp); 354 KERNEL_UNLOCK(); 355 if (rv != 0) 356 goto bad; 357 } 358 } 359 #endif 360 /* 361 * Multicasts with a time-to-live of zero may be looped- 362 * back, above, but must not be transmitted on a network. 363 * Also, multicasts addressed to the loopback interface 364 * are not sent -- the above call to ip_mloopback() will 365 * loop back a copy if this host actually belongs to the 366 * destination group on the loopback interface. 367 */ 368 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) 369 goto bad; 370 371 goto sendit; 372 } 373 374 /* 375 * Look for broadcast address and verify user is allowed to send 376 * such a packet; if the packet is going in an IPsec tunnel, skip 377 * this check. 378 */ 379 if ((tdb == NULL) && ((dst->sin_addr.s_addr == INADDR_BROADCAST) || 380 (ro && ro->ro_rt && ISSET(ro->ro_rt->rt_flags, RTF_BROADCAST)))) { 381 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 382 error = EADDRNOTAVAIL; 383 goto bad; 384 } 385 if ((flags & IP_ALLOWBROADCAST) == 0) { 386 error = EACCES; 387 goto bad; 388 } 389 390 /* Don't allow broadcast messages to be fragmented */ 391 if (ntohs(ip->ip_len) > ifp->if_mtu) { 392 error = EMSGSIZE; 393 goto bad; 394 } 395 m->m_flags |= M_BCAST; 396 } else 397 m->m_flags &= ~M_BCAST; 398 399 sendit: 400 /* 401 * If we're doing Path MTU discovery, we need to set DF unless 402 * the route's MTU is locked. 403 */ 404 if ((flags & IP_MTUDISC) && ro && ro->ro_rt && 405 (ro->ro_rt->rt_locks & RTV_MTU) == 0) 406 ip->ip_off |= htons(IP_DF); 407 408 #ifdef IPSEC 409 /* 410 * Check if the packet needs encapsulation. 411 */ 412 if (tdb != NULL) { 413 /* Callee frees mbuf */ 414 error = ip_output_ipsec_send(tdb, m, ro, 415 (flags & IP_FORWARDING) ? 1 : 0); 416 goto done; 417 } 418 #endif /* IPSEC */ 419 420 /* 421 * Packet filter 422 */ 423 #if NPF > 0 424 if (pf_test(AF_INET, (flags & IP_FORWARDING) ? PF_FWD : PF_OUT, 425 ifp, &m) != PF_PASS) { 426 error = EACCES; 427 goto bad; 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 goto bad; 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 (in_ifcap_cksum(m, ifp, IFCAP_CSUM_IPv4)) 462 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 463 else { 464 ipstat_inc(ips_outswcsum); 465 ip->ip_sum = in_cksum(m, hlen); 466 } 467 468 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 469 goto done; 470 } 471 472 /* 473 * Too large for interface; fragment if possible. 474 * Must be able to put at least 8 bytes per fragment. 475 */ 476 if (ip->ip_off & htons(IP_DF)) { 477 #ifdef IPSEC 478 if (ip_mtudisc) 479 ipsec_adjust_mtu(m, ifp->if_mtu); 480 #endif 481 error = EMSGSIZE; 482 #if NPF > 0 483 /* pf changed routing table, use orig rtable for path MTU */ 484 if (ro->ro_tableid != orig_rtableid) { 485 rtfree(ro->ro_rt); 486 ro->ro_tableid = orig_rtableid; 487 ro->ro_rt = icmp_mtudisc_clone( 488 satosin(&ro->ro_dst)->sin_addr, ro->ro_tableid, 0); 489 } 490 #endif 491 /* 492 * This case can happen if the user changed the MTU 493 * of an interface after enabling IP on it. Because 494 * most netifs don't keep track of routes pointing to 495 * them, there is no way for one to update all its 496 * routes when the MTU is changed. 497 */ 498 if (rtisvalid(ro->ro_rt) && 499 ISSET(ro->ro_rt->rt_flags, RTF_HOST) && 500 !(ro->ro_rt->rt_locks & RTV_MTU) && 501 (ro->ro_rt->rt_mtu > ifp->if_mtu)) { 502 ro->ro_rt->rt_mtu = ifp->if_mtu; 503 } 504 ipstat_inc(ips_cantfrag); 505 goto bad; 506 } 507 508 error = ip_fragment(m, &fml, ifp, mtu); 509 if (error) 510 goto done; 511 512 while ((m = ml_dequeue(&fml)) != NULL) { 513 error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); 514 if (error) 515 break; 516 } 517 if (error) 518 ml_purge(&fml); 519 else 520 ipstat_inc(ips_fragmented); 521 522 done: 523 if (ro == &iproute && ro->ro_rt) 524 rtfree(ro->ro_rt); 525 if_put(ifp); 526 #ifdef IPSEC 527 tdb_unref(tdb); 528 #endif /* IPSEC */ 529 return (error); 530 531 bad: 532 m_freem(m); 533 goto done; 534 } 535 536 #ifdef IPSEC 537 int 538 ip_output_ipsec_lookup(struct mbuf *m, int hlen, struct inpcb *inp, 539 struct tdb **tdbout, int ipsecflowinfo) 540 { 541 struct m_tag *mtag; 542 struct tdb_ident *tdbi; 543 struct tdb *tdb; 544 struct ipsec_ids *ids = NULL; 545 int error; 546 547 /* Do we have any pending SAs to apply ? */ 548 if (ipsecflowinfo) 549 ids = ipsp_ids_lookup(ipsecflowinfo); 550 error = ipsp_spd_lookup(m, AF_INET, hlen, IPSP_DIRECTION_OUT, 551 NULL, inp, &tdb, ids); 552 ipsp_ids_free(ids); 553 if (error || tdb == NULL) { 554 *tdbout = NULL; 555 return error; 556 } 557 /* Loop detection */ 558 for (mtag = m_tag_first(m); mtag != NULL; mtag = m_tag_next(m, mtag)) { 559 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE) 560 continue; 561 tdbi = (struct tdb_ident *)(mtag + 1); 562 if (tdbi->spi == tdb->tdb_spi && 563 tdbi->proto == tdb->tdb_sproto && 564 tdbi->rdomain == tdb->tdb_rdomain && 565 !memcmp(&tdbi->dst, &tdb->tdb_dst, 566 sizeof(union sockaddr_union))) { 567 /* no IPsec needed */ 568 tdb_unref(tdb); 569 *tdbout = NULL; 570 return 0; 571 } 572 } 573 *tdbout = tdb; 574 return 0; 575 } 576 577 void 578 ip_output_ipsec_pmtu_update(struct tdb *tdb, struct route *ro, 579 struct in_addr dst, int rtableid, int transportmode) 580 { 581 struct rtentry *rt = NULL; 582 int rt_mtucloned = 0; 583 584 /* Find a host route to store the mtu in */ 585 if (ro != NULL) 586 rt = ro->ro_rt; 587 /* but don't add a PMTU route for transport mode SAs */ 588 if (transportmode) 589 rt = NULL; 590 else if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0) { 591 rt = icmp_mtudisc_clone(dst, rtableid, 1); 592 rt_mtucloned = 1; 593 } 594 DPRINTF("spi %08x mtu %d rt %p cloned %d", 595 ntohl(tdb->tdb_spi), tdb->tdb_mtu, rt, rt_mtucloned); 596 if (rt != NULL) { 597 rt->rt_mtu = tdb->tdb_mtu; 598 if (ro != NULL && ro->ro_rt != NULL) { 599 rtfree(ro->ro_rt); 600 ro->ro_rt = rtalloc(&ro->ro_dst, RT_RESOLVE, rtableid); 601 } 602 if (rt_mtucloned) 603 rtfree(rt); 604 } 605 } 606 607 int 608 ip_output_ipsec_send(struct tdb *tdb, struct mbuf *m, struct route *ro, int fwd) 609 { 610 #if NPF > 0 611 struct ifnet *encif; 612 #endif 613 struct ip *ip; 614 struct in_addr dst; 615 int error, rtableid; 616 617 #if NPF > 0 618 /* 619 * Packet filter 620 */ 621 if ((encif = enc_getif(tdb->tdb_rdomain, tdb->tdb_tap)) == NULL || 622 pf_test(AF_INET, fwd ? PF_FWD : PF_OUT, encif, &m) != PF_PASS) { 623 m_freem(m); 624 return EACCES; 625 } 626 if (m == NULL) 627 return 0; 628 /* 629 * PF_TAG_REROUTE handling or not... 630 * Packet is entering IPsec so the routing is 631 * already overruled by the IPsec policy. 632 * Until now the change was not reconsidered. 633 * What's the behaviour? 634 */ 635 in_proto_cksum_out(m, encif); 636 #endif 637 638 /* Check if we are allowed to fragment */ 639 ip = mtod(m, struct ip *); 640 dst = ip->ip_dst; 641 rtableid = m->m_pkthdr.ph_rtableid; 642 if (ip_mtudisc && (ip->ip_off & htons(IP_DF)) && tdb->tdb_mtu && 643 ntohs(ip->ip_len) > tdb->tdb_mtu && 644 tdb->tdb_mtutimeout > gettime()) { 645 int transportmode; 646 647 transportmode = (tdb->tdb_dst.sa.sa_family == AF_INET) && 648 (tdb->tdb_dst.sin.sin_addr.s_addr == dst.s_addr); 649 ip_output_ipsec_pmtu_update(tdb, ro, dst, rtableid, 650 transportmode); 651 ipsec_adjust_mtu(m, tdb->tdb_mtu); 652 m_freem(m); 653 return EMSGSIZE; 654 } 655 /* propagate IP_DF for v4-over-v6 */ 656 if (ip_mtudisc && ip->ip_off & htons(IP_DF)) 657 SET(m->m_pkthdr.csum_flags, M_IPV6_DF_OUT); 658 659 /* 660 * Clear these -- they'll be set in the recursive invocation 661 * as needed. 662 */ 663 m->m_flags &= ~(M_MCAST | M_BCAST); 664 665 /* Callee frees mbuf */ 666 KERNEL_LOCK(); 667 error = ipsp_process_packet(m, tdb, AF_INET, 0); 668 KERNEL_UNLOCK(); 669 if (error) { 670 ipsecstat_inc(ipsec_odrops); 671 tdbstat_inc(tdb, tdb_odrops); 672 } 673 if (ip_mtudisc && error == EMSGSIZE) 674 ip_output_ipsec_pmtu_update(tdb, ro, dst, rtableid, 0); 675 return error; 676 } 677 #endif /* IPSEC */ 678 679 int 680 ip_fragment(struct mbuf *m0, struct mbuf_list *fml, struct ifnet *ifp, 681 u_long mtu) 682 { 683 struct mbuf *m; 684 struct ip *ip; 685 int firstlen, hlen, tlen, len, off; 686 int error; 687 688 ml_init(fml); 689 ml_enqueue(fml, m0); 690 691 ip = mtod(m0, struct ip *); 692 hlen = ip->ip_hl << 2; 693 tlen = m0->m_pkthdr.len; 694 len = (mtu - hlen) &~ 7; 695 if (len < 8) { 696 error = EMSGSIZE; 697 goto bad; 698 } 699 firstlen = len; 700 701 /* 702 * If we are doing fragmentation, we can't defer TCP/UDP 703 * checksumming; compute the checksum and clear the flag. 704 */ 705 in_proto_cksum_out(m0, NULL); 706 707 /* 708 * Loop through length of segment after first fragment, 709 * make new header and copy data of each part and link onto chain. 710 */ 711 for (off = hlen + firstlen; off < tlen; off += len) { 712 struct ip *mhip; 713 int mhlen; 714 715 MGETHDR(m, M_DONTWAIT, MT_HEADER); 716 if (m == NULL) { 717 error = ENOBUFS; 718 goto bad; 719 } 720 ml_enqueue(fml, m); 721 722 if ((error = m_dup_pkthdr(m, m0, M_DONTWAIT)) != 0) 723 goto bad; 724 m->m_data += max_linkhdr; 725 mhip = mtod(m, struct ip *); 726 *mhip = *ip; 727 if (hlen > sizeof(struct ip)) { 728 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 729 mhip->ip_hl = mhlen >> 2; 730 } else 731 mhlen = sizeof(struct ip); 732 m->m_len = mhlen; 733 734 mhip->ip_off = ((off - hlen) >> 3) + 735 (ntohs(ip->ip_off) & ~IP_MF); 736 if (ip->ip_off & htons(IP_MF)) 737 mhip->ip_off |= IP_MF; 738 if (off + len >= tlen) 739 len = tlen - off; 740 else 741 mhip->ip_off |= IP_MF; 742 mhip->ip_off = htons(mhip->ip_off); 743 744 m->m_pkthdr.len = mhlen + len; 745 mhip->ip_len = htons(m->m_pkthdr.len); 746 m->m_next = m_copym(m0, off, len, M_NOWAIT); 747 if (m->m_next == NULL) { 748 error = ENOBUFS; 749 goto bad; 750 } 751 752 mhip->ip_sum = 0; 753 if (in_ifcap_cksum(m, ifp, IFCAP_CSUM_IPv4)) 754 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 755 else { 756 ipstat_inc(ips_outswcsum); 757 mhip->ip_sum = in_cksum(m, mhlen); 758 } 759 } 760 761 /* 762 * Update first fragment by trimming what's been copied out 763 * and updating header, then send each fragment (in order). 764 */ 765 m = m0; 766 m_adj(m, hlen + firstlen - tlen); 767 ip->ip_off |= htons(IP_MF); 768 ip->ip_len = htons(m->m_pkthdr.len); 769 770 ip->ip_sum = 0; 771 if (in_ifcap_cksum(m, ifp, IFCAP_CSUM_IPv4)) 772 m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 773 else { 774 ipstat_inc(ips_outswcsum); 775 ip->ip_sum = in_cksum(m, hlen); 776 } 777 778 ipstat_add(ips_ofragments, ml_len(fml)); 779 return (0); 780 781 bad: 782 ipstat_inc(ips_odropped); 783 ml_purge(fml); 784 return (error); 785 } 786 787 /* 788 * Insert IP options into preformed packet. 789 * Adjust IP destination as required for IP source routing, 790 * as indicated by a non-zero in_addr at the start of the options. 791 */ 792 struct mbuf * 793 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 794 { 795 struct ipoption *p = mtod(opt, struct ipoption *); 796 struct mbuf *n; 797 struct ip *ip = mtod(m, struct ip *); 798 unsigned int optlen; 799 800 optlen = opt->m_len - sizeof(p->ipopt_dst); 801 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 802 return (m); /* XXX should fail */ 803 804 /* check if options will fit to IP header */ 805 if ((optlen + sizeof(struct ip)) > (0x0f << 2)) { 806 *phlen = sizeof(struct ip); 807 return (m); 808 } 809 810 if (p->ipopt_dst.s_addr) 811 ip->ip_dst = p->ipopt_dst; 812 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 813 MGETHDR(n, M_DONTWAIT, MT_HEADER); 814 if (n == NULL) 815 return (m); 816 M_MOVE_HDR(n, m); 817 n->m_pkthdr.len += optlen; 818 m->m_len -= sizeof(struct ip); 819 m->m_data += sizeof(struct ip); 820 n->m_next = m; 821 m = n; 822 m->m_len = optlen + sizeof(struct ip); 823 m->m_data += max_linkhdr; 824 memcpy(mtod(m, caddr_t), ip, sizeof(struct ip)); 825 } else { 826 m->m_data -= optlen; 827 m->m_len += optlen; 828 m->m_pkthdr.len += optlen; 829 memmove(mtod(m, caddr_t), (caddr_t)ip, sizeof(struct ip)); 830 } 831 ip = mtod(m, struct ip *); 832 memcpy(ip + 1, p->ipopt_list, optlen); 833 *phlen = sizeof(struct ip) + optlen; 834 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 835 return (m); 836 } 837 838 /* 839 * Copy options from ip to jp, 840 * omitting those not copied during fragmentation. 841 */ 842 int 843 ip_optcopy(struct ip *ip, struct ip *jp) 844 { 845 u_char *cp, *dp; 846 int opt, optlen, cnt; 847 848 cp = (u_char *)(ip + 1); 849 dp = (u_char *)(jp + 1); 850 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 851 for (; cnt > 0; cnt -= optlen, cp += optlen) { 852 opt = cp[0]; 853 if (opt == IPOPT_EOL) 854 break; 855 if (opt == IPOPT_NOP) { 856 /* Preserve for IP mcast tunnel's LSRR alignment. */ 857 *dp++ = IPOPT_NOP; 858 optlen = 1; 859 continue; 860 } 861 #ifdef DIAGNOSTIC 862 if (cnt < IPOPT_OLEN + sizeof(*cp)) 863 panic("malformed IPv4 option passed to ip_optcopy"); 864 #endif 865 optlen = cp[IPOPT_OLEN]; 866 #ifdef DIAGNOSTIC 867 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 868 panic("malformed IPv4 option passed to ip_optcopy"); 869 #endif 870 /* bogus lengths should have been caught by ip_dooptions */ 871 if (optlen > cnt) 872 optlen = cnt; 873 if (IPOPT_COPIED(opt)) { 874 memcpy(dp, cp, optlen); 875 dp += optlen; 876 } 877 } 878 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 879 *dp++ = IPOPT_EOL; 880 return (optlen); 881 } 882 883 /* 884 * IP socket option processing. 885 */ 886 int 887 ip_ctloutput(int op, struct socket *so, int level, int optname, 888 struct mbuf *m) 889 { 890 struct inpcb *inp = sotoinpcb(so); 891 int optval = 0; 892 struct proc *p = curproc; /* XXX */ 893 int error = 0; 894 u_int rtableid, rtid = 0; 895 896 if (level != IPPROTO_IP) 897 return (EINVAL); 898 899 rtableid = p->p_p->ps_rtableid; 900 901 switch (op) { 902 case PRCO_SETOPT: 903 switch (optname) { 904 case IP_OPTIONS: 905 return (ip_pcbopts(&inp->inp_options, m)); 906 907 case IP_TOS: 908 case IP_TTL: 909 case IP_MINTTL: 910 case IP_RECVOPTS: 911 case IP_RECVRETOPTS: 912 case IP_RECVDSTADDR: 913 case IP_RECVIF: 914 case IP_RECVTTL: 915 case IP_RECVDSTPORT: 916 case IP_RECVRTABLE: 917 case IP_IPSECFLOWINFO: 918 if (m == NULL || m->m_len != sizeof(int)) 919 error = EINVAL; 920 else { 921 optval = *mtod(m, int *); 922 switch (optname) { 923 924 case IP_TOS: 925 inp->inp_ip.ip_tos = optval; 926 break; 927 928 case IP_TTL: 929 if (optval > 0 && optval <= MAXTTL) 930 inp->inp_ip.ip_ttl = optval; 931 else if (optval == -1) 932 inp->inp_ip.ip_ttl = ip_defttl; 933 else 934 error = EINVAL; 935 break; 936 937 case IP_MINTTL: 938 if (optval >= 0 && optval <= MAXTTL) 939 inp->inp_ip_minttl = optval; 940 else 941 error = EINVAL; 942 break; 943 #define OPTSET(bit) \ 944 if (optval) \ 945 inp->inp_flags |= bit; \ 946 else \ 947 inp->inp_flags &= ~bit; 948 949 case IP_RECVOPTS: 950 OPTSET(INP_RECVOPTS); 951 break; 952 953 case IP_RECVRETOPTS: 954 OPTSET(INP_RECVRETOPTS); 955 break; 956 957 case IP_RECVDSTADDR: 958 OPTSET(INP_RECVDSTADDR); 959 break; 960 case IP_RECVIF: 961 OPTSET(INP_RECVIF); 962 break; 963 case IP_RECVTTL: 964 OPTSET(INP_RECVTTL); 965 break; 966 case IP_RECVDSTPORT: 967 OPTSET(INP_RECVDSTPORT); 968 break; 969 case IP_RECVRTABLE: 970 OPTSET(INP_RECVRTABLE); 971 break; 972 case IP_IPSECFLOWINFO: 973 OPTSET(INP_IPSECFLOWINFO); 974 break; 975 } 976 } 977 break; 978 #undef OPTSET 979 980 case IP_MULTICAST_IF: 981 case IP_MULTICAST_TTL: 982 case IP_MULTICAST_LOOP: 983 case IP_ADD_MEMBERSHIP: 984 case IP_DROP_MEMBERSHIP: 985 error = ip_setmoptions(optname, &inp->inp_moptions, m, 986 inp->inp_rtableid); 987 break; 988 989 case IP_PORTRANGE: 990 if (m == NULL || m->m_len != sizeof(int)) 991 error = EINVAL; 992 else { 993 optval = *mtod(m, int *); 994 995 switch (optval) { 996 997 case IP_PORTRANGE_DEFAULT: 998 inp->inp_flags &= ~(INP_LOWPORT); 999 inp->inp_flags &= ~(INP_HIGHPORT); 1000 break; 1001 1002 case IP_PORTRANGE_HIGH: 1003 inp->inp_flags &= ~(INP_LOWPORT); 1004 inp->inp_flags |= INP_HIGHPORT; 1005 break; 1006 1007 case IP_PORTRANGE_LOW: 1008 inp->inp_flags &= ~(INP_HIGHPORT); 1009 inp->inp_flags |= INP_LOWPORT; 1010 break; 1011 1012 default: 1013 1014 error = EINVAL; 1015 break; 1016 } 1017 } 1018 break; 1019 case IP_AUTH_LEVEL: 1020 case IP_ESP_TRANS_LEVEL: 1021 case IP_ESP_NETWORK_LEVEL: 1022 case IP_IPCOMP_LEVEL: 1023 #ifndef IPSEC 1024 error = EOPNOTSUPP; 1025 #else 1026 if (m == NULL || m->m_len != sizeof(int)) { 1027 error = EINVAL; 1028 break; 1029 } 1030 optval = *mtod(m, int *); 1031 1032 if (optval < IPSEC_LEVEL_BYPASS || 1033 optval > IPSEC_LEVEL_UNIQUE) { 1034 error = EINVAL; 1035 break; 1036 } 1037 1038 switch (optname) { 1039 case IP_AUTH_LEVEL: 1040 if (optval < IPSEC_AUTH_LEVEL_DEFAULT && 1041 suser(p)) { 1042 error = EACCES; 1043 break; 1044 } 1045 inp->inp_seclevel[SL_AUTH] = optval; 1046 break; 1047 1048 case IP_ESP_TRANS_LEVEL: 1049 if (optval < IPSEC_ESP_TRANS_LEVEL_DEFAULT && 1050 suser(p)) { 1051 error = EACCES; 1052 break; 1053 } 1054 inp->inp_seclevel[SL_ESP_TRANS] = optval; 1055 break; 1056 1057 case IP_ESP_NETWORK_LEVEL: 1058 if (optval < IPSEC_ESP_NETWORK_LEVEL_DEFAULT && 1059 suser(p)) { 1060 error = EACCES; 1061 break; 1062 } 1063 inp->inp_seclevel[SL_ESP_NETWORK] = optval; 1064 break; 1065 case IP_IPCOMP_LEVEL: 1066 if (optval < IPSEC_IPCOMP_LEVEL_DEFAULT && 1067 suser(p)) { 1068 error = EACCES; 1069 break; 1070 } 1071 inp->inp_seclevel[SL_IPCOMP] = optval; 1072 break; 1073 } 1074 #endif 1075 break; 1076 1077 case IP_IPSEC_LOCAL_ID: 1078 case IP_IPSEC_REMOTE_ID: 1079 error = EOPNOTSUPP; 1080 break; 1081 case SO_RTABLE: 1082 if (m == NULL || m->m_len < sizeof(u_int)) { 1083 error = EINVAL; 1084 break; 1085 } 1086 rtid = *mtod(m, u_int *); 1087 if (inp->inp_rtableid == rtid) 1088 break; 1089 /* needs privileges to switch when already set */ 1090 if (rtableid != rtid && rtableid != 0 && 1091 (error = suser(p)) != 0) 1092 break; 1093 /* table must exist */ 1094 if (!rtable_exists(rtid)) { 1095 error = EINVAL; 1096 break; 1097 } 1098 if (inp->inp_lport) { 1099 error = EBUSY; 1100 break; 1101 } 1102 inp->inp_rtableid = rtid; 1103 in_pcbrehash(inp); 1104 break; 1105 case IP_PIPEX: 1106 if (m != NULL && m->m_len == sizeof(int)) 1107 inp->inp_pipex = *mtod(m, int *); 1108 else 1109 error = EINVAL; 1110 break; 1111 1112 default: 1113 error = ENOPROTOOPT; 1114 break; 1115 } 1116 break; 1117 1118 case PRCO_GETOPT: 1119 switch (optname) { 1120 case IP_OPTIONS: 1121 case IP_RETOPTS: 1122 if (inp->inp_options) { 1123 m->m_len = inp->inp_options->m_len; 1124 memcpy(mtod(m, caddr_t), 1125 mtod(inp->inp_options, caddr_t), m->m_len); 1126 } else 1127 m->m_len = 0; 1128 break; 1129 1130 case IP_TOS: 1131 case IP_TTL: 1132 case IP_MINTTL: 1133 case IP_RECVOPTS: 1134 case IP_RECVRETOPTS: 1135 case IP_RECVDSTADDR: 1136 case IP_RECVIF: 1137 case IP_RECVTTL: 1138 case IP_RECVDSTPORT: 1139 case IP_RECVRTABLE: 1140 case IP_IPSECFLOWINFO: 1141 case IP_IPDEFTTL: 1142 m->m_len = sizeof(int); 1143 switch (optname) { 1144 1145 case IP_TOS: 1146 optval = inp->inp_ip.ip_tos; 1147 break; 1148 1149 case IP_TTL: 1150 optval = inp->inp_ip.ip_ttl; 1151 break; 1152 1153 case IP_MINTTL: 1154 optval = inp->inp_ip_minttl; 1155 break; 1156 1157 case IP_IPDEFTTL: 1158 optval = ip_defttl; 1159 break; 1160 1161 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1162 1163 case IP_RECVOPTS: 1164 optval = OPTBIT(INP_RECVOPTS); 1165 break; 1166 1167 case IP_RECVRETOPTS: 1168 optval = OPTBIT(INP_RECVRETOPTS); 1169 break; 1170 1171 case IP_RECVDSTADDR: 1172 optval = OPTBIT(INP_RECVDSTADDR); 1173 break; 1174 case IP_RECVIF: 1175 optval = OPTBIT(INP_RECVIF); 1176 break; 1177 case IP_RECVTTL: 1178 optval = OPTBIT(INP_RECVTTL); 1179 break; 1180 case IP_RECVDSTPORT: 1181 optval = OPTBIT(INP_RECVDSTPORT); 1182 break; 1183 case IP_RECVRTABLE: 1184 optval = OPTBIT(INP_RECVRTABLE); 1185 break; 1186 case IP_IPSECFLOWINFO: 1187 optval = OPTBIT(INP_IPSECFLOWINFO); 1188 break; 1189 } 1190 *mtod(m, int *) = optval; 1191 break; 1192 1193 case IP_MULTICAST_IF: 1194 case IP_MULTICAST_TTL: 1195 case IP_MULTICAST_LOOP: 1196 case IP_ADD_MEMBERSHIP: 1197 case IP_DROP_MEMBERSHIP: 1198 error = ip_getmoptions(optname, inp->inp_moptions, m); 1199 break; 1200 1201 case IP_PORTRANGE: 1202 m->m_len = sizeof(int); 1203 1204 if (inp->inp_flags & INP_HIGHPORT) 1205 optval = IP_PORTRANGE_HIGH; 1206 else if (inp->inp_flags & INP_LOWPORT) 1207 optval = IP_PORTRANGE_LOW; 1208 else 1209 optval = 0; 1210 1211 *mtod(m, int *) = optval; 1212 break; 1213 1214 case IP_AUTH_LEVEL: 1215 case IP_ESP_TRANS_LEVEL: 1216 case IP_ESP_NETWORK_LEVEL: 1217 case IP_IPCOMP_LEVEL: 1218 #ifndef IPSEC 1219 m->m_len = sizeof(int); 1220 *mtod(m, int *) = IPSEC_LEVEL_NONE; 1221 #else 1222 m->m_len = sizeof(int); 1223 switch (optname) { 1224 case IP_AUTH_LEVEL: 1225 optval = inp->inp_seclevel[SL_AUTH]; 1226 break; 1227 1228 case IP_ESP_TRANS_LEVEL: 1229 optval = inp->inp_seclevel[SL_ESP_TRANS]; 1230 break; 1231 1232 case IP_ESP_NETWORK_LEVEL: 1233 optval = inp->inp_seclevel[SL_ESP_NETWORK]; 1234 break; 1235 case IP_IPCOMP_LEVEL: 1236 optval = inp->inp_seclevel[SL_IPCOMP]; 1237 break; 1238 } 1239 *mtod(m, int *) = optval; 1240 #endif 1241 break; 1242 case IP_IPSEC_LOCAL_ID: 1243 case IP_IPSEC_REMOTE_ID: 1244 error = EOPNOTSUPP; 1245 break; 1246 case SO_RTABLE: 1247 m->m_len = sizeof(u_int); 1248 *mtod(m, u_int *) = inp->inp_rtableid; 1249 break; 1250 case IP_PIPEX: 1251 m->m_len = sizeof(int); 1252 *mtod(m, int *) = inp->inp_pipex; 1253 break; 1254 default: 1255 error = ENOPROTOOPT; 1256 break; 1257 } 1258 break; 1259 } 1260 return (error); 1261 } 1262 1263 /* 1264 * Set up IP options in pcb for insertion in output packets. 1265 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1266 * with destination address if source routed. 1267 */ 1268 int 1269 ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) 1270 { 1271 struct mbuf *n; 1272 struct ipoption *p; 1273 int cnt, off, optlen; 1274 u_char *cp; 1275 u_char opt; 1276 1277 /* turn off any old options */ 1278 m_freem(*pcbopt); 1279 *pcbopt = NULL; 1280 if (m == NULL || m->m_len == 0) { 1281 /* 1282 * Only turning off any previous options. 1283 */ 1284 return (0); 1285 } 1286 1287 if (m->m_len % sizeof(int32_t) || 1288 m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1289 return (EINVAL); 1290 1291 /* Don't sleep because NET_LOCK() is hold. */ 1292 if ((n = m_get(M_NOWAIT, MT_SOOPTS)) == NULL) 1293 return (ENOBUFS); 1294 p = mtod(n, struct ipoption *); 1295 memset(p, 0, sizeof (*p)); /* 0 = IPOPT_EOL, needed for padding */ 1296 n->m_len = sizeof(struct in_addr); 1297 1298 off = 0; 1299 cnt = m->m_len; 1300 cp = mtod(m, u_char *); 1301 1302 while (cnt > 0) { 1303 opt = cp[IPOPT_OPTVAL]; 1304 1305 if (opt == IPOPT_NOP || opt == IPOPT_EOL) { 1306 optlen = 1; 1307 } else { 1308 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1309 goto bad; 1310 optlen = cp[IPOPT_OLEN]; 1311 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1312 goto bad; 1313 } 1314 switch (opt) { 1315 default: 1316 memcpy(p->ipopt_list + off, cp, optlen); 1317 break; 1318 1319 case IPOPT_LSRR: 1320 case IPOPT_SSRR: 1321 /* 1322 * user process specifies route as: 1323 * ->A->B->C->D 1324 * D must be our final destination (but we can't 1325 * check that since we may not have connected yet). 1326 * A is first hop destination, which doesn't appear in 1327 * actual IP option, but is stored before the options. 1328 */ 1329 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1330 goto bad; 1331 1332 /* 1333 * Optlen is smaller because first address is popped. 1334 * Cnt and cp will be adjusted a bit later to reflect 1335 * this. 1336 */ 1337 optlen -= sizeof(struct in_addr); 1338 p->ipopt_list[off + IPOPT_OPTVAL] = opt; 1339 p->ipopt_list[off + IPOPT_OLEN] = optlen; 1340 1341 /* 1342 * Move first hop before start of options. 1343 */ 1344 memcpy(&p->ipopt_dst, cp + IPOPT_OFFSET, 1345 sizeof(struct in_addr)); 1346 cp += sizeof(struct in_addr); 1347 cnt -= sizeof(struct in_addr); 1348 /* 1349 * Then copy rest of options 1350 */ 1351 memcpy(p->ipopt_list + off + IPOPT_OFFSET, 1352 cp + IPOPT_OFFSET, optlen - IPOPT_OFFSET); 1353 break; 1354 } 1355 off += optlen; 1356 cp += optlen; 1357 cnt -= optlen; 1358 1359 if (opt == IPOPT_EOL) 1360 break; 1361 } 1362 /* pad options to next word, since p was zeroed just adjust off */ 1363 off = (off + sizeof(int32_t) - 1) & ~(sizeof(int32_t) - 1); 1364 n->m_len += off; 1365 if (n->m_len > sizeof(*p)) { 1366 bad: 1367 m_freem(n); 1368 return (EINVAL); 1369 } 1370 1371 *pcbopt = n; 1372 return (0); 1373 } 1374 1375 /* 1376 * Lookup the interface based on the information in the ip_mreqn struct. 1377 */ 1378 int 1379 ip_multicast_if(struct ip_mreqn *mreq, u_int rtableid, unsigned int *ifidx) 1380 { 1381 struct sockaddr_in sin; 1382 struct rtentry *rt; 1383 1384 /* 1385 * In case userland provides the imr_ifindex use this as interface. 1386 * If no interface address was provided, use the interface of 1387 * the route to the given multicast address. 1388 */ 1389 if (mreq->imr_ifindex != 0) { 1390 *ifidx = mreq->imr_ifindex; 1391 } else if (mreq->imr_address.s_addr == INADDR_ANY) { 1392 memset(&sin, 0, sizeof(sin)); 1393 sin.sin_len = sizeof(sin); 1394 sin.sin_family = AF_INET; 1395 sin.sin_addr = mreq->imr_multiaddr; 1396 rt = rtalloc(sintosa(&sin), RT_RESOLVE, rtableid); 1397 if (!rtisvalid(rt)) { 1398 rtfree(rt); 1399 return EADDRNOTAVAIL; 1400 } 1401 *ifidx = rt->rt_ifidx; 1402 rtfree(rt); 1403 } else { 1404 memset(&sin, 0, sizeof(sin)); 1405 sin.sin_len = sizeof(sin); 1406 sin.sin_family = AF_INET; 1407 sin.sin_addr = mreq->imr_address; 1408 rt = rtalloc(sintosa(&sin), 0, rtableid); 1409 if (!rtisvalid(rt) || !ISSET(rt->rt_flags, RTF_LOCAL)) { 1410 rtfree(rt); 1411 return EADDRNOTAVAIL; 1412 } 1413 *ifidx = rt->rt_ifidx; 1414 rtfree(rt); 1415 } 1416 1417 return 0; 1418 } 1419 1420 /* 1421 * Set the IP multicast options in response to user setsockopt(). 1422 */ 1423 int 1424 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m, 1425 u_int rtableid) 1426 { 1427 struct in_addr addr; 1428 struct in_ifaddr *ia; 1429 struct ip_mreqn mreqn; 1430 struct ifnet *ifp = NULL; 1431 struct ip_moptions *imo = *imop; 1432 struct in_multi **immp; 1433 struct sockaddr_in sin; 1434 unsigned int ifidx; 1435 int i, error = 0; 1436 u_char loop; 1437 1438 if (imo == NULL) { 1439 /* 1440 * No multicast option buffer attached to the pcb; 1441 * allocate one and initialize to default values. 1442 */ 1443 imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK|M_ZERO); 1444 immp = mallocarray(IP_MIN_MEMBERSHIPS, sizeof(*immp), M_IPMOPTS, 1445 M_WAITOK|M_ZERO); 1446 *imop = imo; 1447 imo->imo_ifidx = 0; 1448 imo->imo_ttl = IP_DEFAULT_MULTICAST_TTL; 1449 imo->imo_loop = IP_DEFAULT_MULTICAST_LOOP; 1450 imo->imo_num_memberships = 0; 1451 imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; 1452 imo->imo_membership = immp; 1453 } 1454 1455 switch (optname) { 1456 1457 case IP_MULTICAST_IF: 1458 /* 1459 * Select the interface for outgoing multicast packets. 1460 */ 1461 if (m == NULL) { 1462 error = EINVAL; 1463 break; 1464 } 1465 if (m->m_len == sizeof(struct in_addr)) { 1466 addr = *(mtod(m, struct in_addr *)); 1467 } else if (m->m_len == sizeof(struct ip_mreq) || 1468 m->m_len == sizeof(struct ip_mreqn)) { 1469 memset(&mreqn, 0, sizeof(mreqn)); 1470 memcpy(&mreqn, mtod(m, void *), m->m_len); 1471 1472 /* 1473 * If an interface index is given use this 1474 * index to set the imo_ifidx but check first 1475 * that the interface actually exists. 1476 * In the other case just set the addr to 1477 * the imr_address and fall through to the 1478 * regular code. 1479 */ 1480 if (mreqn.imr_ifindex != 0) { 1481 ifp = if_get(mreqn.imr_ifindex); 1482 if (ifp == NULL || 1483 ifp->if_rdomain != rtable_l2(rtableid)) { 1484 error = EADDRNOTAVAIL; 1485 if_put(ifp); 1486 break; 1487 } 1488 imo->imo_ifidx = ifp->if_index; 1489 if_put(ifp); 1490 break; 1491 } else 1492 addr = mreqn.imr_address; 1493 } else { 1494 error = EINVAL; 1495 break; 1496 } 1497 /* 1498 * INADDR_ANY is used to remove a previous selection. 1499 * When no interface is selected, a default one is 1500 * chosen every time a multicast packet is sent. 1501 */ 1502 if (addr.s_addr == INADDR_ANY) { 1503 imo->imo_ifidx = 0; 1504 break; 1505 } 1506 /* 1507 * The selected interface is identified by its local 1508 * IP address. Find the interface and confirm that 1509 * it supports multicasting. 1510 */ 1511 memset(&sin, 0, sizeof(sin)); 1512 sin.sin_len = sizeof(sin); 1513 sin.sin_family = AF_INET; 1514 sin.sin_addr = addr; 1515 ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); 1516 if (ia == NULL || 1517 (ia->ia_ifp->if_flags & IFF_MULTICAST) == 0) { 1518 error = EADDRNOTAVAIL; 1519 break; 1520 } 1521 imo->imo_ifidx = ia->ia_ifp->if_index; 1522 break; 1523 1524 case IP_MULTICAST_TTL: 1525 /* 1526 * Set the IP time-to-live for outgoing multicast packets. 1527 */ 1528 if (m == NULL || m->m_len != 1) { 1529 error = EINVAL; 1530 break; 1531 } 1532 imo->imo_ttl = *(mtod(m, u_char *)); 1533 break; 1534 1535 case IP_MULTICAST_LOOP: 1536 /* 1537 * Set the loopback flag for outgoing multicast packets. 1538 * Must be zero or one. 1539 */ 1540 if (m == NULL || m->m_len != 1 || 1541 (loop = *(mtod(m, u_char *))) > 1) { 1542 error = EINVAL; 1543 break; 1544 } 1545 imo->imo_loop = loop; 1546 break; 1547 1548 case IP_ADD_MEMBERSHIP: 1549 /* 1550 * Add a multicast group membership. 1551 * Group must be a valid IP multicast address. 1552 */ 1553 if (m == NULL || !(m->m_len == sizeof(struct ip_mreq) || 1554 m->m_len == sizeof(struct ip_mreqn))) { 1555 error = EINVAL; 1556 break; 1557 } 1558 memset(&mreqn, 0, sizeof(mreqn)); 1559 memcpy(&mreqn, mtod(m, void *), m->m_len); 1560 if (!IN_MULTICAST(mreqn.imr_multiaddr.s_addr)) { 1561 error = EINVAL; 1562 break; 1563 } 1564 1565 error = ip_multicast_if(&mreqn, rtableid, &ifidx); 1566 if (error) 1567 break; 1568 1569 /* 1570 * See if we found an interface, and confirm that it 1571 * supports multicast. 1572 */ 1573 ifp = if_get(ifidx); 1574 if (ifp == NULL || ifp->if_rdomain != rtable_l2(rtableid) || 1575 (ifp->if_flags & IFF_MULTICAST) == 0) { 1576 error = EADDRNOTAVAIL; 1577 if_put(ifp); 1578 break; 1579 } 1580 1581 /* 1582 * See if the membership already exists or if all the 1583 * membership slots are full. 1584 */ 1585 for (i = 0; i < imo->imo_num_memberships; ++i) { 1586 if (imo->imo_membership[i]->inm_ifidx == ifidx && 1587 imo->imo_membership[i]->inm_addr.s_addr 1588 == mreqn.imr_multiaddr.s_addr) 1589 break; 1590 } 1591 if (i < imo->imo_num_memberships) { 1592 error = EADDRINUSE; 1593 if_put(ifp); 1594 break; 1595 } 1596 if (imo->imo_num_memberships == imo->imo_max_memberships) { 1597 struct in_multi **nmships, **omships; 1598 size_t newmax; 1599 /* 1600 * Resize the vector to next power-of-two minus 1. If 1601 * the size would exceed the maximum then we know we've 1602 * really run out of entries. Otherwise, we reallocate 1603 * the vector. 1604 */ 1605 nmships = NULL; 1606 omships = imo->imo_membership; 1607 newmax = ((imo->imo_max_memberships + 1) * 2) - 1; 1608 if (newmax <= IP_MAX_MEMBERSHIPS) { 1609 nmships = mallocarray(newmax, sizeof(*nmships), 1610 M_IPMOPTS, M_NOWAIT|M_ZERO); 1611 if (nmships != NULL) { 1612 memcpy(nmships, omships, 1613 sizeof(*omships) * 1614 imo->imo_max_memberships); 1615 free(omships, M_IPMOPTS, 1616 sizeof(*omships) * 1617 imo->imo_max_memberships); 1618 imo->imo_membership = nmships; 1619 imo->imo_max_memberships = newmax; 1620 } 1621 } 1622 if (nmships == NULL) { 1623 error = ENOBUFS; 1624 if_put(ifp); 1625 break; 1626 } 1627 } 1628 /* 1629 * Everything looks good; add a new record to the multicast 1630 * address list for the given interface. 1631 */ 1632 if ((imo->imo_membership[i] = 1633 in_addmulti(&mreqn.imr_multiaddr, ifp)) == NULL) { 1634 error = ENOBUFS; 1635 if_put(ifp); 1636 break; 1637 } 1638 ++imo->imo_num_memberships; 1639 if_put(ifp); 1640 break; 1641 1642 case IP_DROP_MEMBERSHIP: 1643 /* 1644 * Drop a multicast group membership. 1645 * Group must be a valid IP multicast address. 1646 */ 1647 if (m == NULL || !(m->m_len == sizeof(struct ip_mreq) || 1648 m->m_len == sizeof(struct ip_mreqn))) { 1649 error = EINVAL; 1650 break; 1651 } 1652 memset(&mreqn, 0, sizeof(mreqn)); 1653 memcpy(&mreqn, mtod(m, void *), m->m_len); 1654 if (!IN_MULTICAST(mreqn.imr_multiaddr.s_addr)) { 1655 error = EINVAL; 1656 break; 1657 } 1658 1659 /* 1660 * If an interface address was specified, get a pointer 1661 * to its ifnet structure. 1662 */ 1663 error = ip_multicast_if(&mreqn, rtableid, &ifidx); 1664 if (error) 1665 break; 1666 1667 /* 1668 * Find the membership in the membership array. 1669 */ 1670 for (i = 0; i < imo->imo_num_memberships; ++i) { 1671 if ((ifidx == 0 || 1672 imo->imo_membership[i]->inm_ifidx == ifidx) && 1673 imo->imo_membership[i]->inm_addr.s_addr == 1674 mreqn.imr_multiaddr.s_addr) 1675 break; 1676 } 1677 if (i == imo->imo_num_memberships) { 1678 error = EADDRNOTAVAIL; 1679 break; 1680 } 1681 /* 1682 * Give up the multicast address record to which the 1683 * membership points. 1684 */ 1685 in_delmulti(imo->imo_membership[i]); 1686 /* 1687 * Remove the gap in the membership array. 1688 */ 1689 for (++i; i < imo->imo_num_memberships; ++i) 1690 imo->imo_membership[i-1] = imo->imo_membership[i]; 1691 --imo->imo_num_memberships; 1692 break; 1693 1694 default: 1695 error = EOPNOTSUPP; 1696 break; 1697 } 1698 1699 /* 1700 * If all options have default values, no need to keep the data. 1701 */ 1702 if (imo->imo_ifidx == 0 && 1703 imo->imo_ttl == IP_DEFAULT_MULTICAST_TTL && 1704 imo->imo_loop == IP_DEFAULT_MULTICAST_LOOP && 1705 imo->imo_num_memberships == 0) { 1706 free(imo->imo_membership , M_IPMOPTS, 1707 imo->imo_max_memberships * sizeof(struct in_multi *)); 1708 free(*imop, M_IPMOPTS, sizeof(**imop)); 1709 *imop = NULL; 1710 } 1711 1712 return (error); 1713 } 1714 1715 /* 1716 * Return the IP multicast options in response to user getsockopt(). 1717 */ 1718 int 1719 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf *m) 1720 { 1721 u_char *ttl; 1722 u_char *loop; 1723 struct in_addr *addr; 1724 struct in_ifaddr *ia; 1725 struct ifnet *ifp; 1726 1727 switch (optname) { 1728 1729 case IP_MULTICAST_IF: 1730 addr = mtod(m, struct in_addr *); 1731 m->m_len = sizeof(struct in_addr); 1732 if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL) 1733 addr->s_addr = INADDR_ANY; 1734 else { 1735 IFP_TO_IA(ifp, ia); 1736 addr->s_addr = (ia == NULL) ? INADDR_ANY 1737 : ia->ia_addr.sin_addr.s_addr; 1738 if_put(ifp); 1739 } 1740 return (0); 1741 1742 case IP_MULTICAST_TTL: 1743 ttl = mtod(m, u_char *); 1744 m->m_len = 1; 1745 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1746 : imo->imo_ttl; 1747 return (0); 1748 1749 case IP_MULTICAST_LOOP: 1750 loop = mtod(m, u_char *); 1751 m->m_len = 1; 1752 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1753 : imo->imo_loop; 1754 return (0); 1755 1756 default: 1757 return (EOPNOTSUPP); 1758 } 1759 } 1760 1761 /* 1762 * Discard the IP multicast options. 1763 */ 1764 void 1765 ip_freemoptions(struct ip_moptions *imo) 1766 { 1767 int i; 1768 1769 if (imo != NULL) { 1770 for (i = 0; i < imo->imo_num_memberships; ++i) 1771 in_delmulti(imo->imo_membership[i]); 1772 free(imo->imo_membership, M_IPMOPTS, 1773 imo->imo_max_memberships * sizeof(struct in_multi *)); 1774 free(imo, M_IPMOPTS, sizeof(*imo)); 1775 } 1776 } 1777 1778 /* 1779 * Routine called from ip_output() to loop back a copy of an IP multicast 1780 * packet to the input queue of a specified interface. 1781 */ 1782 void 1783 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1784 { 1785 struct ip *ip; 1786 struct mbuf *copym; 1787 1788 copym = m_dup_pkt(m, max_linkhdr, M_DONTWAIT); 1789 if (copym != NULL) { 1790 /* 1791 * We don't bother to fragment if the IP length is greater 1792 * than the interface's MTU. Can this possibly matter? 1793 */ 1794 ip = mtod(copym, struct ip *); 1795 ip->ip_sum = 0; 1796 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1797 if_input_local(ifp, copym, dst->sin_family); 1798 } 1799 } 1800 1801 /* 1802 * Compute significant parts of the IPv4 checksum pseudo-header 1803 * for use in a delayed TCP/UDP checksum calculation. 1804 */ 1805 static __inline u_int16_t __attribute__((__unused__)) 1806 in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) 1807 { 1808 u_int32_t sum; 1809 1810 sum = lenproto + 1811 (u_int16_t)(src >> 16) + 1812 (u_int16_t)(src /*& 0xffff*/) + 1813 (u_int16_t)(dst >> 16) + 1814 (u_int16_t)(dst /*& 0xffff*/); 1815 1816 sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); 1817 1818 if (sum > 0xffff) 1819 sum -= 0xffff; 1820 1821 return (sum); 1822 } 1823 1824 /* 1825 * Process a delayed payload checksum calculation. 1826 */ 1827 void 1828 in_delayed_cksum(struct mbuf *m) 1829 { 1830 struct ip *ip; 1831 u_int16_t csum, offset; 1832 1833 ip = mtod(m, struct ip *); 1834 offset = ip->ip_hl << 2; 1835 csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset); 1836 if (csum == 0 && ip->ip_p == IPPROTO_UDP) 1837 csum = 0xffff; 1838 1839 switch (ip->ip_p) { 1840 case IPPROTO_TCP: 1841 offset += offsetof(struct tcphdr, th_sum); 1842 break; 1843 1844 case IPPROTO_UDP: 1845 offset += offsetof(struct udphdr, uh_sum); 1846 break; 1847 1848 case IPPROTO_ICMP: 1849 offset += offsetof(struct icmp, icmp_cksum); 1850 break; 1851 1852 default: 1853 return; 1854 } 1855 1856 if ((offset + sizeof(u_int16_t)) > m->m_len) 1857 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1858 else 1859 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1860 } 1861 1862 void 1863 in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp) 1864 { 1865 struct ip *ip = mtod(m, struct ip *); 1866 1867 /* some hw and in_delayed_cksum need the pseudo header cksum */ 1868 if (m->m_pkthdr.csum_flags & 1869 (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT|M_ICMP_CSUM_OUT)) { 1870 u_int16_t csum = 0, offset; 1871 1872 offset = ip->ip_hl << 2; 1873 if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) 1874 csum = in_cksum_phdr(ip->ip_src.s_addr, 1875 ip->ip_dst.s_addr, htonl(ntohs(ip->ip_len) - 1876 offset + ip->ip_p)); 1877 if (ip->ip_p == IPPROTO_TCP) 1878 offset += offsetof(struct tcphdr, th_sum); 1879 else if (ip->ip_p == IPPROTO_UDP) 1880 offset += offsetof(struct udphdr, uh_sum); 1881 else if (ip->ip_p == IPPROTO_ICMP) 1882 offset += offsetof(struct icmp, icmp_cksum); 1883 if ((offset + sizeof(u_int16_t)) > m->m_len) 1884 m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); 1885 else 1886 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1887 } 1888 1889 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) { 1890 if (!in_ifcap_cksum(m, ifp, IFCAP_CSUM_TCPv4) || 1891 ip->ip_hl != 5) { 1892 tcpstat_inc(tcps_outswcsum); 1893 in_delayed_cksum(m); 1894 m->m_pkthdr.csum_flags &= ~M_TCP_CSUM_OUT; /* Clear */ 1895 } 1896 } else if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) { 1897 if (!in_ifcap_cksum(m, ifp, IFCAP_CSUM_UDPv4) || 1898 ip->ip_hl != 5) { 1899 udpstat_inc(udps_outswcsum); 1900 in_delayed_cksum(m); 1901 m->m_pkthdr.csum_flags &= ~M_UDP_CSUM_OUT; /* Clear */ 1902 } 1903 } else if (m->m_pkthdr.csum_flags & M_ICMP_CSUM_OUT) { 1904 in_delayed_cksum(m); 1905 m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */ 1906 } 1907 } 1908 1909 int 1910 in_ifcap_cksum(struct mbuf *m, struct ifnet *ifp, int ifcap) 1911 { 1912 if ((ifp == NULL) || 1913 !ISSET(ifp->if_capabilities, ifcap) || 1914 (ifp->if_bridgeidx != 0)) 1915 return (0); 1916 /* 1917 * Simplex interface sends packet back without hardware cksum. 1918 * Keep this check in sync with the condition where ether_resolve() 1919 * calls if_input_local(). 1920 */ 1921 if (ISSET(m->m_flags, M_BCAST) && 1922 ISSET(ifp->if_flags, IFF_SIMPLEX) && 1923 !m->m_pkthdr.pf.routed) 1924 return (0); 1925 return (1); 1926 } 1927