1 /* $NetBSD: ip_output.c,v 1.314 2019/06/05 01:31:04 knakahara Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1998 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Public Access Networks Corporation ("Panix"). It was developed under 38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 /* 63 * Copyright (c) 1982, 1986, 1988, 1990, 1993 64 * The Regents of the University of California. All rights reserved. 65 * 66 * Redistribution and use in source and binary forms, with or without 67 * modification, are permitted provided that the following conditions 68 * are met: 69 * 1. Redistributions of source code must retain the above copyright 70 * notice, this list of conditions and the following disclaimer. 71 * 2. Redistributions in binary form must reproduce the above copyright 72 * notice, this list of conditions and the following disclaimer in the 73 * documentation and/or other materials provided with the distribution. 74 * 3. Neither the name of the University nor the names of its contributors 75 * may be used to endorse or promote products derived from this software 76 * without specific prior written permission. 77 * 78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 88 * SUCH DAMAGE. 89 * 90 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 91 */ 92 93 #include <sys/cdefs.h> 94 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.314 2019/06/05 01:31:04 knakahara Exp $"); 95 96 #ifdef _KERNEL_OPT 97 #include "opt_inet.h" 98 #include "opt_ipsec.h" 99 #include "opt_mrouting.h" 100 #include "opt_net_mpsafe.h" 101 #include "opt_mpls.h" 102 #endif 103 104 #include "arp.h" 105 106 #include <sys/param.h> 107 #include <sys/kmem.h> 108 #include <sys/mbuf.h> 109 #include <sys/socket.h> 110 #include <sys/socketvar.h> 111 #include <sys/kauth.h> 112 #include <sys/systm.h> 113 #include <sys/syslog.h> 114 115 #include <net/if.h> 116 #include <net/if_types.h> 117 #include <net/route.h> 118 #include <net/pfil.h> 119 120 #include <netinet/in.h> 121 #include <netinet/in_systm.h> 122 #include <netinet/ip.h> 123 #include <netinet/in_pcb.h> 124 #include <netinet/in_var.h> 125 #include <netinet/ip_var.h> 126 #include <netinet/ip_private.h> 127 #include <netinet/in_offload.h> 128 #include <netinet/portalgo.h> 129 #include <netinet/udp.h> 130 #include <netinet/udp_var.h> 131 132 #ifdef INET6 133 #include <netinet6/ip6_var.h> 134 #endif 135 136 #ifdef MROUTING 137 #include <netinet/ip_mroute.h> 138 #endif 139 140 #ifdef IPSEC 141 #include <netipsec/ipsec.h> 142 #include <netipsec/key.h> 143 #endif 144 145 #ifdef MPLS 146 #include <netmpls/mpls.h> 147 #include <netmpls/mpls_var.h> 148 #endif 149 150 static int ip_pcbopts(struct inpcb *, const struct sockopt *); 151 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 152 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 153 static void ip_mloopback(struct ifnet *, struct mbuf *, 154 const struct sockaddr_in *); 155 static int ip_ifaddrvalid(const struct in_ifaddr *); 156 157 extern pfil_head_t *inet_pfil_hook; /* XXX */ 158 159 int ip_do_loopback_cksum = 0; 160 161 static int 162 ip_mark_mpls(struct ifnet * const ifp, struct mbuf * const m, 163 const struct rtentry *rt) 164 { 165 int error = 0; 166 #ifdef MPLS 167 union mpls_shim msh; 168 169 if (rt == NULL || rt_gettag(rt) == NULL || 170 rt_gettag(rt)->sa_family != AF_MPLS || 171 (m->m_flags & (M_MCAST | M_BCAST)) != 0 || 172 ifp->if_type != IFT_ETHER) 173 return 0; 174 175 msh.s_addr = MPLS_GETSADDR(rt); 176 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 177 struct m_tag *mtag; 178 /* 179 * XXX tentative solution to tell ether_output 180 * it's MPLS. Need some more efficient solution. 181 */ 182 mtag = m_tag_get(PACKET_TAG_MPLS, 183 sizeof(int) /* dummy */, 184 M_NOWAIT); 185 if (mtag == NULL) 186 return ENOMEM; 187 m_tag_prepend(m, mtag); 188 } 189 #endif 190 return error; 191 } 192 193 /* 194 * Send an IP packet to a host. 195 */ 196 int 197 ip_if_output(struct ifnet * const ifp, struct mbuf * const m, 198 const struct sockaddr * const dst, const struct rtentry *rt) 199 { 200 int error = 0; 201 202 if (rt != NULL) { 203 error = rt_check_reject_route(rt, ifp); 204 if (error != 0) { 205 m_freem(m); 206 return error; 207 } 208 } 209 210 error = ip_mark_mpls(ifp, m, rt); 211 if (error != 0) { 212 m_freem(m); 213 return error; 214 } 215 216 error = if_output_lock(ifp, ifp, m, dst, rt); 217 218 return error; 219 } 220 221 /* 222 * IP output. The packet in mbuf chain m contains a skeletal IP 223 * header (with len, off, ttl, proto, tos, src, dst). 224 * The mbuf chain containing the packet will be freed. 225 * The mbuf opt, if present, will not be freed. 226 */ 227 int 228 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 229 struct ip_moptions *imo, struct inpcb *inp) 230 { 231 struct rtentry *rt; 232 struct ip *ip; 233 struct ifnet *ifp, *mifp = NULL; 234 struct mbuf *m = m0; 235 int len, hlen, error = 0; 236 struct route iproute; 237 const struct sockaddr_in *dst; 238 struct in_ifaddr *ia = NULL; 239 struct ifaddr *ifa; 240 int isbroadcast; 241 int sw_csum; 242 u_long mtu; 243 bool natt_frag = false; 244 bool rtmtu_nolock; 245 union { 246 struct sockaddr sa; 247 struct sockaddr_in sin; 248 } udst, usrc; 249 struct sockaddr *rdst = &udst.sa; /* real IP destination, as 250 * opposed to the nexthop 251 */ 252 struct psref psref, psref_ia; 253 int bound; 254 bool bind_need_restore = false; 255 256 len = 0; 257 258 MCLAIM(m, &ip_tx_mowner); 259 260 KASSERT((m->m_flags & M_PKTHDR) != 0); 261 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 262 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 263 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 264 KASSERT(m->m_len >= sizeof(struct ip)); 265 266 hlen = sizeof(struct ip); 267 if (opt) { 268 m = ip_insertoptions(m, opt, &len); 269 hlen = len; 270 } 271 ip = mtod(m, struct ip *); 272 273 /* 274 * Fill in IP header. 275 */ 276 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 277 ip->ip_v = IPVERSION; 278 ip->ip_off = htons(0); 279 /* ip->ip_id filled in after we find out source ia */ 280 ip->ip_hl = hlen >> 2; 281 IP_STATINC(IP_STAT_LOCALOUT); 282 } else { 283 hlen = ip->ip_hl << 2; 284 } 285 286 /* 287 * Route packet. 288 */ 289 if (ro == NULL) { 290 memset(&iproute, 0, sizeof(iproute)); 291 ro = &iproute; 292 } 293 sockaddr_in_init(&udst.sin, &ip->ip_dst, 0); 294 dst = satocsin(rtcache_getdst(ro)); 295 296 /* 297 * If there is a cached route, check that it is to the same 298 * destination and is still up. If not, free it and try again. 299 * The address family should also be checked in case of sharing 300 * the cache with IPv6. 301 */ 302 if (dst && (dst->sin_family != AF_INET || 303 !in_hosteq(dst->sin_addr, ip->ip_dst))) 304 rtcache_free(ro); 305 306 /* XXX must be before rtcache operations */ 307 bound = curlwp_bind(); 308 bind_need_restore = true; 309 310 if ((rt = rtcache_validate(ro)) == NULL && 311 (rt = rtcache_update(ro, 1)) == NULL) { 312 dst = &udst.sin; 313 error = rtcache_setdst(ro, &udst.sa); 314 if (error != 0) 315 goto bad; 316 } 317 318 /* 319 * If routing to interface only, short circuit routing lookup. 320 */ 321 if (flags & IP_ROUTETOIF) { 322 ifa = ifa_ifwithladdr_psref(sintocsa(dst), &psref_ia); 323 if (ifa == NULL) { 324 IP_STATINC(IP_STAT_NOROUTE); 325 error = ENETUNREACH; 326 goto bad; 327 } 328 /* ia is already referenced by psref_ia */ 329 ia = ifatoia(ifa); 330 331 ifp = ia->ia_ifp; 332 mtu = ifp->if_mtu; 333 ip->ip_ttl = 1; 334 isbroadcast = in_broadcast(dst->sin_addr, ifp); 335 } else if (((IN_MULTICAST(ip->ip_dst.s_addr) || 336 ip->ip_dst.s_addr == INADDR_BROADCAST) || 337 (flags & IP_ROUTETOIFINDEX)) && 338 imo != NULL && imo->imo_multicast_if_index != 0) { 339 ifp = mifp = if_get_byindex(imo->imo_multicast_if_index, &psref); 340 if (ifp == NULL) { 341 IP_STATINC(IP_STAT_NOROUTE); 342 error = ENETUNREACH; 343 goto bad; 344 } 345 mtu = ifp->if_mtu; 346 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 347 if (ia == NULL) { 348 error = EADDRNOTAVAIL; 349 goto bad; 350 } 351 if (IN_MULTICAST(ip->ip_dst.s_addr) || 352 ip->ip_dst.s_addr == INADDR_BROADCAST) { 353 isbroadcast = 0; 354 } else { 355 /* IP_ROUTETOIFINDEX */ 356 isbroadcast = in_broadcast(dst->sin_addr, ifp); 357 if ((isbroadcast == 0) && ((ifp->if_flags & 358 (IFF_LOOPBACK | IFF_POINTOPOINT)) == 0) && 359 (in_direct(dst->sin_addr, ifp) == 0)) { 360 /* gateway address required */ 361 if (rt == NULL) 362 rt = rtcache_init(ro); 363 if (rt == NULL || rt->rt_ifp != ifp) { 364 IP_STATINC(IP_STAT_NOROUTE); 365 error = EHOSTUNREACH; 366 goto bad; 367 } 368 rt->rt_use++; 369 if (rt->rt_flags & RTF_GATEWAY) 370 dst = satosin(rt->rt_gateway); 371 if (rt->rt_flags & RTF_HOST) 372 isbroadcast = 373 rt->rt_flags & RTF_BROADCAST; 374 } 375 } 376 } else { 377 if (rt == NULL) 378 rt = rtcache_init(ro); 379 if (rt == NULL) { 380 IP_STATINC(IP_STAT_NOROUTE); 381 error = EHOSTUNREACH; 382 goto bad; 383 } 384 if (ifa_is_destroying(rt->rt_ifa)) { 385 rtcache_unref(rt, ro); 386 rt = NULL; 387 IP_STATINC(IP_STAT_NOROUTE); 388 error = EHOSTUNREACH; 389 goto bad; 390 } 391 ifa_acquire(rt->rt_ifa, &psref_ia); 392 ia = ifatoia(rt->rt_ifa); 393 ifp = rt->rt_ifp; 394 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 395 mtu = ifp->if_mtu; 396 rt->rt_use++; 397 if (rt->rt_flags & RTF_GATEWAY) 398 dst = satosin(rt->rt_gateway); 399 if (rt->rt_flags & RTF_HOST) 400 isbroadcast = rt->rt_flags & RTF_BROADCAST; 401 else 402 isbroadcast = in_broadcast(dst->sin_addr, ifp); 403 } 404 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 405 406 if (IN_MULTICAST(ip->ip_dst.s_addr) || 407 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 408 bool inmgroup; 409 410 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 411 M_BCAST : M_MCAST; 412 /* 413 * See if the caller provided any multicast options 414 */ 415 if (imo != NULL) 416 ip->ip_ttl = imo->imo_multicast_ttl; 417 else 418 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 419 420 /* 421 * if we don't know the outgoing ifp yet, we can't generate 422 * output 423 */ 424 if (!ifp) { 425 IP_STATINC(IP_STAT_NOROUTE); 426 error = ENETUNREACH; 427 goto bad; 428 } 429 430 /* 431 * If the packet is multicast or broadcast, confirm that 432 * the outgoing interface can transmit it. 433 */ 434 if (((m->m_flags & M_MCAST) && 435 (ifp->if_flags & IFF_MULTICAST) == 0) || 436 ((m->m_flags & M_BCAST) && 437 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 438 IP_STATINC(IP_STAT_NOROUTE); 439 error = ENETUNREACH; 440 goto bad; 441 } 442 /* 443 * If source address not specified yet, use an address 444 * of outgoing interface. 445 */ 446 if (in_nullhost(ip->ip_src)) { 447 struct in_ifaddr *xia; 448 struct ifaddr *xifa; 449 struct psref _psref; 450 451 xia = in_get_ia_from_ifp_psref(ifp, &_psref); 452 if (!xia) { 453 error = EADDRNOTAVAIL; 454 goto bad; 455 } 456 xifa = &xia->ia_ifa; 457 if (xifa->ifa_getifa != NULL) { 458 ia4_release(xia, &_psref); 459 /* FIXME ifa_getifa is NOMPSAFE */ 460 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 461 if (xia == NULL) { 462 error = EADDRNOTAVAIL; 463 goto bad; 464 } 465 ia4_acquire(xia, &_psref); 466 } 467 ip->ip_src = xia->ia_addr.sin_addr; 468 ia4_release(xia, &_psref); 469 } 470 471 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 472 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 473 /* 474 * If we belong to the destination multicast group 475 * on the outgoing interface, and the caller did not 476 * forbid loopback, loop back a copy. 477 */ 478 ip_mloopback(ifp, m, &udst.sin); 479 } 480 #ifdef MROUTING 481 else { 482 /* 483 * If we are acting as a multicast router, perform 484 * multicast forwarding as if the packet had just 485 * arrived on the interface to which we are about 486 * to send. The multicast forwarding function 487 * recursively calls this function, using the 488 * IP_FORWARDING flag to prevent infinite recursion. 489 * 490 * Multicasts that are looped back by ip_mloopback(), 491 * above, will be forwarded by the ip_input() routine, 492 * if necessary. 493 */ 494 extern struct socket *ip_mrouter; 495 496 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 497 if (ip_mforward(m, ifp) != 0) { 498 m_freem(m); 499 goto done; 500 } 501 } 502 } 503 #endif 504 /* 505 * Multicasts with a time-to-live of zero may be looped- 506 * back, above, but must not be transmitted on a network. 507 * Also, multicasts addressed to the loopback interface 508 * are not sent -- the above call to ip_mloopback() will 509 * loop back a copy if this host actually belongs to the 510 * destination group on the loopback interface. 511 */ 512 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 513 m_freem(m); 514 goto done; 515 } 516 goto sendit; 517 } 518 519 /* 520 * If source address not specified yet, use address 521 * of outgoing interface. 522 */ 523 if (in_nullhost(ip->ip_src)) { 524 struct ifaddr *xifa; 525 526 xifa = &ia->ia_ifa; 527 if (xifa->ifa_getifa != NULL) { 528 ia4_release(ia, &psref_ia); 529 /* FIXME ifa_getifa is NOMPSAFE */ 530 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 531 if (ia == NULL) { 532 error = EADDRNOTAVAIL; 533 goto bad; 534 } 535 ia4_acquire(ia, &psref_ia); 536 } 537 ip->ip_src = ia->ia_addr.sin_addr; 538 } 539 540 /* 541 * Packets with Class-D address as source are not valid per 542 * RFC1112. 543 */ 544 if (IN_MULTICAST(ip->ip_src.s_addr)) { 545 IP_STATINC(IP_STAT_ODROPPED); 546 error = EADDRNOTAVAIL; 547 goto bad; 548 } 549 550 /* 551 * Look for broadcast address and verify user is allowed to 552 * send such a packet. 553 */ 554 if (isbroadcast) { 555 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 556 error = EADDRNOTAVAIL; 557 goto bad; 558 } 559 if ((flags & IP_ALLOWBROADCAST) == 0) { 560 error = EACCES; 561 goto bad; 562 } 563 /* don't allow broadcast messages to be fragmented */ 564 if (ntohs(ip->ip_len) > ifp->if_mtu) { 565 error = EMSGSIZE; 566 goto bad; 567 } 568 m->m_flags |= M_BCAST; 569 } else 570 m->m_flags &= ~M_BCAST; 571 572 sendit: 573 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 574 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 575 ip->ip_id = 0; 576 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 577 ip->ip_id = ip_newid(ia); 578 } else { 579 /* 580 * TSO capable interfaces (typically?) increment 581 * ip_id for each segment. 582 * "allocate" enough ids here to increase the chance 583 * for them to be unique. 584 * 585 * note that the following calculation is not 586 * needed to be precise. wasting some ip_id is fine. 587 */ 588 589 unsigned int segsz = m->m_pkthdr.segsz; 590 unsigned int datasz = ntohs(ip->ip_len) - hlen; 591 unsigned int num = howmany(datasz, segsz); 592 593 ip->ip_id = ip_newid_range(ia, num); 594 } 595 } 596 if (ia != NULL) { 597 ia4_release(ia, &psref_ia); 598 ia = NULL; 599 } 600 601 /* 602 * If we're doing Path MTU Discovery, we need to set DF unless 603 * the route's MTU is locked. 604 */ 605 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 606 ip->ip_off |= htons(IP_DF); 607 } 608 609 #ifdef IPSEC 610 if (ipsec_used) { 611 bool ipsec_done = false; 612 613 /* Perform IPsec processing, if any. */ 614 error = ipsec4_output(m, inp, flags, &mtu, &natt_frag, 615 &ipsec_done); 616 if (error || ipsec_done) 617 goto done; 618 } 619 620 if (!ipsec_used || !natt_frag) 621 #endif 622 { 623 /* 624 * Run through list of hooks for output packets. 625 */ 626 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 627 if (error || m == NULL) { 628 IP_STATINC(IP_STAT_PFILDROP_OUT); 629 goto done; 630 } 631 } 632 633 ip = mtod(m, struct ip *); 634 hlen = ip->ip_hl << 2; 635 636 m->m_pkthdr.csum_data |= hlen << 16; 637 638 /* 639 * search for the source address structure to 640 * maintain output statistics, and verify address 641 * validity 642 */ 643 KASSERT(ia == NULL); 644 sockaddr_in_init(&usrc.sin, &ip->ip_src, 0); 645 ifa = ifaof_ifpforaddr_psref(&usrc.sa, ifp, &psref_ia); 646 if (ifa != NULL) 647 ia = ifatoia(ifa); 648 649 /* 650 * Ensure we only send from a valid address. 651 * A NULL address is valid because the packet could be 652 * generated from a packet filter. 653 */ 654 if (ia != NULL && (flags & IP_FORWARDING) == 0 && 655 (error = ip_ifaddrvalid(ia)) != 0) 656 { 657 ARPLOG(LOG_ERR, 658 "refusing to send from invalid address %s (pid %d)\n", 659 ARPLOGADDR(&ip->ip_src), curproc->p_pid); 660 IP_STATINC(IP_STAT_ODROPPED); 661 if (error == 1) 662 /* 663 * Address exists, but is tentative or detached. 664 * We can't send from it because it's invalid, 665 * so we drop the packet. 666 */ 667 error = 0; 668 else 669 error = EADDRNOTAVAIL; 670 goto bad; 671 } 672 673 /* Maybe skip checksums on loopback interfaces. */ 674 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 675 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 676 } 677 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 678 679 /* 680 * If small enough for mtu of path, or if using TCP segmentation 681 * offload, can just send directly. 682 */ 683 if (ntohs(ip->ip_len) <= mtu || 684 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 685 const struct sockaddr *sa; 686 687 #if IFA_STATS 688 if (ia) 689 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 690 #endif 691 /* 692 * Always initialize the sum to 0! Some HW assisted 693 * checksumming requires this. 694 */ 695 ip->ip_sum = 0; 696 697 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 698 /* 699 * Perform any checksums that the hardware can't do 700 * for us. 701 * 702 * XXX Does any hardware require the {th,uh}_sum 703 * XXX fields to be 0? 704 */ 705 if (sw_csum & M_CSUM_IPv4) { 706 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 707 ip->ip_sum = in_cksum(m, hlen); 708 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 709 } 710 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 711 if (IN_NEED_CHECKSUM(ifp, 712 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 713 in_undefer_cksum_tcpudp(m); 714 } 715 m->m_pkthdr.csum_flags &= 716 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 717 } 718 } 719 720 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 721 if (__predict_false(sw_csum & M_CSUM_TSOv4)) { 722 /* 723 * TSO4 is required by a packet, but disabled for 724 * the interface. 725 */ 726 error = ip_tso_output(ifp, m, sa, rt); 727 } else 728 error = ip_if_output(ifp, m, sa, rt); 729 goto done; 730 } 731 732 /* 733 * We can't use HW checksumming if we're about to fragment the packet. 734 * 735 * XXX Some hardware can do this. 736 */ 737 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 738 if (IN_NEED_CHECKSUM(ifp, 739 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 740 in_undefer_cksum_tcpudp(m); 741 } 742 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 743 } 744 745 /* 746 * Too large for interface; fragment if possible. 747 * Must be able to put at least 8 bytes per fragment. 748 */ 749 if (ntohs(ip->ip_off) & IP_DF) { 750 if (flags & IP_RETURNMTU) { 751 KASSERT(inp != NULL); 752 inp->inp_errormtu = mtu; 753 } 754 error = EMSGSIZE; 755 IP_STATINC(IP_STAT_CANTFRAG); 756 goto bad; 757 } 758 759 error = ip_fragment(m, ifp, mtu); 760 if (error) { 761 m = NULL; 762 goto bad; 763 } 764 765 for (; m; m = m0) { 766 m0 = m->m_nextpkt; 767 m->m_nextpkt = NULL; 768 if (error) { 769 m_freem(m); 770 continue; 771 } 772 #if IFA_STATS 773 if (ia) 774 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 775 #endif 776 /* 777 * If we get there, the packet has not been handled by 778 * IPsec whereas it should have. Now that it has been 779 * fragmented, re-inject it in ip_output so that IPsec 780 * processing can occur. 781 */ 782 if (natt_frag) { 783 error = ip_output(m, opt, NULL, 784 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 785 imo, inp); 786 } else { 787 KASSERT((m->m_pkthdr.csum_flags & 788 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 789 error = ip_if_output(ifp, m, 790 (m->m_flags & M_MCAST) ? 791 sintocsa(rdst) : sintocsa(dst), rt); 792 } 793 } 794 if (error == 0) { 795 IP_STATINC(IP_STAT_FRAGMENTED); 796 } 797 798 done: 799 ia4_release(ia, &psref_ia); 800 rtcache_unref(rt, ro); 801 if (ro == &iproute) { 802 rtcache_free(&iproute); 803 } 804 if (mifp != NULL) { 805 if_put(mifp, &psref); 806 } 807 if (bind_need_restore) 808 curlwp_bindx(bound); 809 return error; 810 811 bad: 812 m_freem(m); 813 goto done; 814 } 815 816 int 817 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 818 { 819 struct ip *ip, *mhip; 820 struct mbuf *m0; 821 int len, hlen, off; 822 int mhlen, firstlen; 823 struct mbuf **mnext; 824 int sw_csum = m->m_pkthdr.csum_flags; 825 int fragments = 0; 826 int error = 0; 827 int ipoff, ipflg; 828 829 ip = mtod(m, struct ip *); 830 hlen = ip->ip_hl << 2; 831 832 /* Preserve the offset and flags. */ 833 ipoff = ntohs(ip->ip_off) & IP_OFFMASK; 834 ipflg = ntohs(ip->ip_off) & (IP_RF|IP_DF|IP_MF); 835 836 if (ifp != NULL) 837 sw_csum &= ~ifp->if_csum_flags_tx; 838 839 len = (mtu - hlen) &~ 7; 840 if (len < 8) { 841 m_freem(m); 842 return EMSGSIZE; 843 } 844 845 firstlen = len; 846 mnext = &m->m_nextpkt; 847 848 /* 849 * Loop through length of segment after first fragment, 850 * make new header and copy data of each part and link onto chain. 851 */ 852 m0 = m; 853 mhlen = sizeof(struct ip); 854 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 855 MGETHDR(m, M_DONTWAIT, MT_HEADER); 856 if (m == NULL) { 857 error = ENOBUFS; 858 IP_STATINC(IP_STAT_ODROPPED); 859 goto sendorfree; 860 } 861 MCLAIM(m, m0->m_owner); 862 863 *mnext = m; 864 mnext = &m->m_nextpkt; 865 866 m->m_data += max_linkhdr; 867 mhip = mtod(m, struct ip *); 868 *mhip = *ip; 869 870 /* we must inherit the flags */ 871 m->m_flags |= m0->m_flags & M_COPYFLAGS; 872 873 if (hlen > sizeof(struct ip)) { 874 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 875 mhip->ip_hl = mhlen >> 2; 876 } 877 m->m_len = mhlen; 878 879 mhip->ip_off = ((off - hlen) >> 3) + ipoff; 880 mhip->ip_off |= ipflg; 881 if (off + len >= ntohs(ip->ip_len)) 882 len = ntohs(ip->ip_len) - off; 883 else 884 mhip->ip_off |= IP_MF; 885 HTONS(mhip->ip_off); 886 887 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 888 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 889 if (m->m_next == NULL) { 890 error = ENOBUFS; 891 IP_STATINC(IP_STAT_ODROPPED); 892 goto sendorfree; 893 } 894 895 m->m_pkthdr.len = mhlen + len; 896 m_reset_rcvif(m); 897 898 mhip->ip_sum = 0; 899 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 900 if (sw_csum & M_CSUM_IPv4) { 901 mhip->ip_sum = in_cksum(m, mhlen); 902 } else { 903 /* 904 * checksum is hw-offloaded or not necessary. 905 */ 906 m->m_pkthdr.csum_flags |= 907 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 908 m->m_pkthdr.csum_data |= mhlen << 16; 909 KASSERT(!(ifp != NULL && 910 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 911 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 912 } 913 IP_STATINC(IP_STAT_OFRAGMENTS); 914 fragments++; 915 } 916 917 /* 918 * Update first fragment by trimming what's been copied out 919 * and updating header, then send each fragment (in order). 920 */ 921 m = m0; 922 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 923 m->m_pkthdr.len = hlen + firstlen; 924 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 925 ip->ip_off |= htons(IP_MF); 926 ip->ip_sum = 0; 927 if (sw_csum & M_CSUM_IPv4) { 928 ip->ip_sum = in_cksum(m, hlen); 929 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 930 } else { 931 /* 932 * checksum is hw-offloaded or not necessary. 933 */ 934 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 935 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 936 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 937 sizeof(struct ip)); 938 } 939 940 sendorfree: 941 /* 942 * If there is no room for all the fragments, don't queue 943 * any of them. 944 */ 945 if (ifp != NULL) { 946 IFQ_LOCK(&ifp->if_snd); 947 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 948 error == 0) { 949 error = ENOBUFS; 950 IP_STATINC(IP_STAT_ODROPPED); 951 IFQ_INC_DROPS(&ifp->if_snd); 952 } 953 IFQ_UNLOCK(&ifp->if_snd); 954 } 955 if (error) { 956 for (m = m0; m; m = m0) { 957 m0 = m->m_nextpkt; 958 m->m_nextpkt = NULL; 959 m_freem(m); 960 } 961 } 962 963 return error; 964 } 965 966 /* 967 * Determine the maximum length of the options to be inserted; 968 * we would far rather allocate too much space rather than too little. 969 */ 970 u_int 971 ip_optlen(struct inpcb *inp) 972 { 973 struct mbuf *m = inp->inp_options; 974 975 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 976 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 977 } 978 return 0; 979 } 980 981 /* 982 * Insert IP options into preformed packet. 983 * Adjust IP destination as required for IP source routing, 984 * as indicated by a non-zero in_addr at the start of the options. 985 */ 986 static struct mbuf * 987 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 988 { 989 struct ipoption *p = mtod(opt, struct ipoption *); 990 struct mbuf *n; 991 struct ip *ip = mtod(m, struct ip *); 992 unsigned optlen; 993 994 optlen = opt->m_len - sizeof(p->ipopt_dst); 995 KASSERT(optlen % 4 == 0); 996 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 997 return m; /* XXX should fail */ 998 if (!in_nullhost(p->ipopt_dst)) 999 ip->ip_dst = p->ipopt_dst; 1000 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1001 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1002 if (n == NULL) 1003 return m; 1004 MCLAIM(n, m->m_owner); 1005 m_move_pkthdr(n, m); 1006 m->m_len -= sizeof(struct ip); 1007 m->m_data += sizeof(struct ip); 1008 n->m_next = m; 1009 n->m_len = optlen + sizeof(struct ip); 1010 n->m_data += max_linkhdr; 1011 memcpy(mtod(n, void *), ip, sizeof(struct ip)); 1012 m = n; 1013 } else { 1014 m->m_data -= optlen; 1015 m->m_len += optlen; 1016 memmove(mtod(m, void *), ip, sizeof(struct ip)); 1017 } 1018 m->m_pkthdr.len += optlen; 1019 ip = mtod(m, struct ip *); 1020 memcpy(ip + 1, p->ipopt_list, optlen); 1021 *phlen = sizeof(struct ip) + optlen; 1022 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1023 return m; 1024 } 1025 1026 /* 1027 * Copy options from ipsrc to ipdst, omitting those not copied during 1028 * fragmentation. 1029 */ 1030 int 1031 ip_optcopy(struct ip *ipsrc, struct ip *ipdst) 1032 { 1033 u_char *cp, *dp; 1034 int opt, optlen, cnt; 1035 1036 cp = (u_char *)(ipsrc + 1); 1037 dp = (u_char *)(ipdst + 1); 1038 cnt = (ipsrc->ip_hl << 2) - sizeof(struct ip); 1039 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1040 opt = cp[0]; 1041 if (opt == IPOPT_EOL) 1042 break; 1043 if (opt == IPOPT_NOP) { 1044 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1045 *dp++ = IPOPT_NOP; 1046 optlen = 1; 1047 continue; 1048 } 1049 1050 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 1051 optlen = cp[IPOPT_OLEN]; 1052 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 1053 1054 /* Invalid lengths should have been caught by ip_dooptions. */ 1055 if (optlen > cnt) 1056 optlen = cnt; 1057 if (IPOPT_COPIED(opt)) { 1058 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 1059 dp += optlen; 1060 } 1061 } 1062 1063 for (optlen = dp - (u_char *)(ipdst+1); optlen & 0x3; optlen++) { 1064 *dp++ = IPOPT_EOL; 1065 } 1066 1067 return optlen; 1068 } 1069 1070 /* 1071 * IP socket option processing. 1072 */ 1073 int 1074 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 1075 { 1076 struct inpcb *inp = sotoinpcb(so); 1077 struct ip *ip = &inp->inp_ip; 1078 int inpflags = inp->inp_flags; 1079 int optval = 0, error = 0; 1080 struct in_pktinfo pktinfo; 1081 1082 KASSERT(solocked(so)); 1083 1084 if (sopt->sopt_level != IPPROTO_IP) { 1085 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1086 return 0; 1087 return ENOPROTOOPT; 1088 } 1089 1090 switch (op) { 1091 case PRCO_SETOPT: 1092 switch (sopt->sopt_name) { 1093 case IP_OPTIONS: 1094 #ifdef notyet 1095 case IP_RETOPTS: 1096 #endif 1097 error = ip_pcbopts(inp, sopt); 1098 break; 1099 1100 case IP_TOS: 1101 case IP_TTL: 1102 case IP_MINTTL: 1103 case IP_RECVOPTS: 1104 case IP_RECVRETOPTS: 1105 case IP_RECVDSTADDR: 1106 case IP_RECVIF: 1107 case IP_RECVPKTINFO: 1108 case IP_RECVTTL: 1109 error = sockopt_getint(sopt, &optval); 1110 if (error) 1111 break; 1112 1113 switch (sopt->sopt_name) { 1114 case IP_TOS: 1115 ip->ip_tos = optval; 1116 break; 1117 1118 case IP_TTL: 1119 ip->ip_ttl = optval; 1120 break; 1121 1122 case IP_MINTTL: 1123 if (optval > 0 && optval <= MAXTTL) 1124 inp->inp_ip_minttl = optval; 1125 else 1126 error = EINVAL; 1127 break; 1128 #define OPTSET(bit) \ 1129 if (optval) \ 1130 inpflags |= bit; \ 1131 else \ 1132 inpflags &= ~bit; 1133 1134 case IP_RECVOPTS: 1135 OPTSET(INP_RECVOPTS); 1136 break; 1137 1138 case IP_RECVPKTINFO: 1139 OPTSET(INP_RECVPKTINFO); 1140 break; 1141 1142 case IP_RECVRETOPTS: 1143 OPTSET(INP_RECVRETOPTS); 1144 break; 1145 1146 case IP_RECVDSTADDR: 1147 OPTSET(INP_RECVDSTADDR); 1148 break; 1149 1150 case IP_RECVIF: 1151 OPTSET(INP_RECVIF); 1152 break; 1153 1154 case IP_RECVTTL: 1155 OPTSET(INP_RECVTTL); 1156 break; 1157 } 1158 break; 1159 case IP_PKTINFO: 1160 error = sockopt_getint(sopt, &optval); 1161 if (!error) { 1162 /* Linux compatibility */ 1163 OPTSET(INP_RECVPKTINFO); 1164 break; 1165 } 1166 error = sockopt_get(sopt, &pktinfo, sizeof(pktinfo)); 1167 if (error) 1168 break; 1169 1170 if (pktinfo.ipi_ifindex == 0) { 1171 inp->inp_prefsrcip = pktinfo.ipi_addr; 1172 break; 1173 } 1174 1175 /* Solaris compatibility */ 1176 struct ifnet *ifp; 1177 struct in_ifaddr *ia; 1178 int s; 1179 1180 /* pick up primary address */ 1181 s = pserialize_read_enter(); 1182 ifp = if_byindex(pktinfo.ipi_ifindex); 1183 if (ifp == NULL) { 1184 pserialize_read_exit(s); 1185 error = EADDRNOTAVAIL; 1186 break; 1187 } 1188 ia = in_get_ia_from_ifp(ifp); 1189 if (ia == NULL) { 1190 pserialize_read_exit(s); 1191 error = EADDRNOTAVAIL; 1192 break; 1193 } 1194 inp->inp_prefsrcip = IA_SIN(ia)->sin_addr; 1195 pserialize_read_exit(s); 1196 break; 1197 break; 1198 #undef OPTSET 1199 1200 case IP_MULTICAST_IF: 1201 case IP_MULTICAST_TTL: 1202 case IP_MULTICAST_LOOP: 1203 case IP_ADD_MEMBERSHIP: 1204 case IP_DROP_MEMBERSHIP: 1205 error = ip_setmoptions(&inp->inp_moptions, sopt); 1206 break; 1207 1208 case IP_PORTRANGE: 1209 error = sockopt_getint(sopt, &optval); 1210 if (error) 1211 break; 1212 1213 switch (optval) { 1214 case IP_PORTRANGE_DEFAULT: 1215 case IP_PORTRANGE_HIGH: 1216 inpflags &= ~(INP_LOWPORT); 1217 break; 1218 1219 case IP_PORTRANGE_LOW: 1220 inpflags |= INP_LOWPORT; 1221 break; 1222 1223 default: 1224 error = EINVAL; 1225 break; 1226 } 1227 break; 1228 1229 case IP_PORTALGO: 1230 error = sockopt_getint(sopt, &optval); 1231 if (error) 1232 break; 1233 1234 error = portalgo_algo_index_select( 1235 (struct inpcb_hdr *)inp, optval); 1236 break; 1237 1238 #if defined(IPSEC) 1239 case IP_IPSEC_POLICY: 1240 if (ipsec_enabled) { 1241 error = ipsec_set_policy(inp, 1242 sopt->sopt_data, sopt->sopt_size, 1243 curlwp->l_cred); 1244 } else 1245 error = ENOPROTOOPT; 1246 break; 1247 #endif /* IPSEC */ 1248 1249 default: 1250 error = ENOPROTOOPT; 1251 break; 1252 } 1253 break; 1254 1255 case PRCO_GETOPT: 1256 switch (sopt->sopt_name) { 1257 case IP_OPTIONS: 1258 case IP_RETOPTS: { 1259 struct mbuf *mopts = inp->inp_options; 1260 1261 if (mopts) { 1262 struct mbuf *m; 1263 1264 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1265 if (m == NULL) { 1266 error = ENOBUFS; 1267 break; 1268 } 1269 error = sockopt_setmbuf(sopt, m); 1270 } 1271 break; 1272 } 1273 case IP_TOS: 1274 case IP_TTL: 1275 case IP_MINTTL: 1276 case IP_RECVOPTS: 1277 case IP_RECVRETOPTS: 1278 case IP_RECVDSTADDR: 1279 case IP_RECVIF: 1280 case IP_RECVPKTINFO: 1281 case IP_RECVTTL: 1282 case IP_ERRORMTU: 1283 switch (sopt->sopt_name) { 1284 case IP_TOS: 1285 optval = ip->ip_tos; 1286 break; 1287 1288 case IP_TTL: 1289 optval = ip->ip_ttl; 1290 break; 1291 1292 case IP_MINTTL: 1293 optval = inp->inp_ip_minttl; 1294 break; 1295 1296 case IP_ERRORMTU: 1297 optval = inp->inp_errormtu; 1298 break; 1299 1300 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1301 1302 case IP_RECVOPTS: 1303 optval = OPTBIT(INP_RECVOPTS); 1304 break; 1305 1306 case IP_RECVPKTINFO: 1307 optval = OPTBIT(INP_RECVPKTINFO); 1308 break; 1309 1310 case IP_RECVRETOPTS: 1311 optval = OPTBIT(INP_RECVRETOPTS); 1312 break; 1313 1314 case IP_RECVDSTADDR: 1315 optval = OPTBIT(INP_RECVDSTADDR); 1316 break; 1317 1318 case IP_RECVIF: 1319 optval = OPTBIT(INP_RECVIF); 1320 break; 1321 1322 case IP_RECVTTL: 1323 optval = OPTBIT(INP_RECVTTL); 1324 break; 1325 } 1326 error = sockopt_setint(sopt, optval); 1327 break; 1328 1329 case IP_PKTINFO: 1330 switch (sopt->sopt_size) { 1331 case sizeof(int): 1332 /* Linux compatibility */ 1333 optval = OPTBIT(INP_RECVPKTINFO); 1334 error = sockopt_setint(sopt, optval); 1335 break; 1336 case sizeof(struct in_pktinfo): 1337 /* Solaris compatibility */ 1338 pktinfo.ipi_ifindex = 0; 1339 pktinfo.ipi_addr = inp->inp_prefsrcip; 1340 error = sockopt_set(sopt, &pktinfo, 1341 sizeof(pktinfo)); 1342 break; 1343 default: 1344 /* 1345 * While size is stuck at 0, and, later, if 1346 * the caller doesn't use an exactly sized 1347 * recipient for the data, default to Linux 1348 * compatibility 1349 */ 1350 optval = OPTBIT(INP_RECVPKTINFO); 1351 error = sockopt_setint(sopt, optval); 1352 break; 1353 } 1354 break; 1355 1356 #if 0 /* defined(IPSEC) */ 1357 case IP_IPSEC_POLICY: 1358 { 1359 struct mbuf *m = NULL; 1360 1361 /* XXX this will return EINVAL as sopt is empty */ 1362 error = ipsec_get_policy(inp, sopt->sopt_data, 1363 sopt->sopt_size, &m); 1364 if (error == 0) 1365 error = sockopt_setmbuf(sopt, m); 1366 break; 1367 } 1368 #endif /*IPSEC*/ 1369 1370 case IP_MULTICAST_IF: 1371 case IP_MULTICAST_TTL: 1372 case IP_MULTICAST_LOOP: 1373 case IP_ADD_MEMBERSHIP: 1374 case IP_DROP_MEMBERSHIP: 1375 error = ip_getmoptions(inp->inp_moptions, sopt); 1376 break; 1377 1378 case IP_PORTRANGE: 1379 if (inpflags & INP_LOWPORT) 1380 optval = IP_PORTRANGE_LOW; 1381 else 1382 optval = IP_PORTRANGE_DEFAULT; 1383 error = sockopt_setint(sopt, optval); 1384 break; 1385 1386 case IP_PORTALGO: 1387 optval = inp->inp_portalgo; 1388 error = sockopt_setint(sopt, optval); 1389 break; 1390 1391 default: 1392 error = ENOPROTOOPT; 1393 break; 1394 } 1395 break; 1396 } 1397 1398 if (!error) { 1399 inp->inp_flags = inpflags; 1400 } 1401 return error; 1402 } 1403 1404 static int 1405 ip_pktinfo_prepare(const struct in_pktinfo *pktinfo, struct ip_pktopts *pktopts, 1406 int *flags, kauth_cred_t cred) 1407 { 1408 struct ip_moptions *imo; 1409 int error = 0; 1410 bool addrset = false; 1411 1412 if (!in_nullhost(pktinfo->ipi_addr)) { 1413 pktopts->ippo_laddr.sin_addr = pktinfo->ipi_addr; 1414 /* EADDRNOTAVAIL? */ 1415 error = in_pcbbindableaddr(&pktopts->ippo_laddr, cred); 1416 if (error != 0) 1417 return error; 1418 addrset = true; 1419 } 1420 1421 if (pktinfo->ipi_ifindex != 0) { 1422 if (!addrset) { 1423 struct ifnet *ifp; 1424 struct in_ifaddr *ia; 1425 int s; 1426 1427 /* pick up primary address */ 1428 s = pserialize_read_enter(); 1429 ifp = if_byindex(pktinfo->ipi_ifindex); 1430 if (ifp == NULL) { 1431 pserialize_read_exit(s); 1432 return EADDRNOTAVAIL; 1433 } 1434 ia = in_get_ia_from_ifp(ifp); 1435 if (ia == NULL) { 1436 pserialize_read_exit(s); 1437 return EADDRNOTAVAIL; 1438 } 1439 pktopts->ippo_laddr.sin_addr = IA_SIN(ia)->sin_addr; 1440 pserialize_read_exit(s); 1441 } 1442 1443 /* 1444 * If specified ipi_ifindex, 1445 * use copied or locally initialized ip_moptions. 1446 * Original ip_moptions must not be modified. 1447 */ 1448 imo = &pktopts->ippo_imobuf; /* local buf in pktopts */ 1449 if (pktopts->ippo_imo != NULL) { 1450 memcpy(imo, pktopts->ippo_imo, sizeof(*imo)); 1451 } else { 1452 memset(imo, 0, sizeof(*imo)); 1453 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1454 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1455 } 1456 imo->imo_multicast_if_index = pktinfo->ipi_ifindex; 1457 pktopts->ippo_imo = imo; 1458 *flags |= IP_ROUTETOIFINDEX; 1459 } 1460 return error; 1461 } 1462 1463 /* 1464 * Set up IP outgoing packet options. Even if control is NULL, 1465 * pktopts->ippo_laddr and pktopts->ippo_imo are set and used. 1466 */ 1467 int 1468 ip_setpktopts(struct mbuf *control, struct ip_pktopts *pktopts, int *flags, 1469 struct inpcb *inp, kauth_cred_t cred) 1470 { 1471 struct cmsghdr *cm; 1472 struct in_pktinfo pktinfo; 1473 int error; 1474 1475 pktopts->ippo_imo = inp->inp_moptions; 1476 1477 struct in_addr *ia = in_nullhost(inp->inp_prefsrcip) ? &inp->inp_laddr : 1478 &inp->inp_prefsrcip; 1479 sockaddr_in_init(&pktopts->ippo_laddr, ia, 0); 1480 1481 if (control == NULL) 1482 return 0; 1483 1484 /* 1485 * XXX: Currently, we assume all the optional information is 1486 * stored in a single mbuf. 1487 */ 1488 if (control->m_next) 1489 return EINVAL; 1490 1491 for (; control->m_len > 0; 1492 control->m_data += CMSG_ALIGN(cm->cmsg_len), 1493 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) { 1494 cm = mtod(control, struct cmsghdr *); 1495 if ((control->m_len < sizeof(*cm)) || 1496 (cm->cmsg_len == 0) || 1497 (cm->cmsg_len > control->m_len)) { 1498 return EINVAL; 1499 } 1500 if (cm->cmsg_level != IPPROTO_IP) 1501 continue; 1502 1503 switch (cm->cmsg_type) { 1504 case IP_PKTINFO: 1505 if (cm->cmsg_len != CMSG_LEN(sizeof(pktinfo))) 1506 return EINVAL; 1507 memcpy(&pktinfo, CMSG_DATA(cm), sizeof(pktinfo)); 1508 error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, 1509 cred); 1510 if (error) 1511 return error; 1512 break; 1513 case IP_SENDSRCADDR: /* FreeBSD compatibility */ 1514 if (cm->cmsg_len != CMSG_LEN(sizeof(struct in_addr))) 1515 return EINVAL; 1516 pktinfo.ipi_ifindex = 0; 1517 pktinfo.ipi_addr = 1518 ((struct in_pktinfo *)CMSG_DATA(cm))->ipi_addr; 1519 error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, 1520 cred); 1521 if (error) 1522 return error; 1523 break; 1524 default: 1525 return ENOPROTOOPT; 1526 } 1527 } 1528 return 0; 1529 } 1530 1531 /* 1532 * Set up IP options in pcb for insertion in output packets. 1533 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1534 * with destination address if source routed. 1535 */ 1536 static int 1537 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1538 { 1539 struct mbuf *m; 1540 const u_char *cp; 1541 u_char *dp; 1542 int cnt; 1543 1544 KASSERT(inp_locked(inp)); 1545 1546 /* Turn off any old options. */ 1547 if (inp->inp_options) { 1548 m_free(inp->inp_options); 1549 } 1550 inp->inp_options = NULL; 1551 if ((cnt = sopt->sopt_size) == 0) { 1552 /* Only turning off any previous options. */ 1553 return 0; 1554 } 1555 cp = sopt->sopt_data; 1556 1557 if (cnt % 4) { 1558 /* Must be 4-byte aligned, because there's no padding. */ 1559 return EINVAL; 1560 } 1561 1562 m = m_get(M_DONTWAIT, MT_SOOPTS); 1563 if (m == NULL) 1564 return ENOBUFS; 1565 1566 dp = mtod(m, u_char *); 1567 memset(dp, 0, sizeof(struct in_addr)); 1568 dp += sizeof(struct in_addr); 1569 m->m_len = sizeof(struct in_addr); 1570 1571 /* 1572 * IP option list according to RFC791. Each option is of the form 1573 * 1574 * [optval] [olen] [(olen - 2) data bytes] 1575 * 1576 * We validate the list and copy options to an mbuf for prepending 1577 * to data packets. The IP first-hop destination address will be 1578 * stored before actual options and is zero if unset. 1579 */ 1580 while (cnt > 0) { 1581 uint8_t optval, olen, offset; 1582 1583 optval = cp[IPOPT_OPTVAL]; 1584 1585 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1586 olen = 1; 1587 } else { 1588 if (cnt < IPOPT_OLEN + 1) 1589 goto bad; 1590 1591 olen = cp[IPOPT_OLEN]; 1592 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1593 goto bad; 1594 } 1595 1596 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1597 /* 1598 * user process specifies route as: 1599 * ->A->B->C->D 1600 * D must be our final destination (but we can't 1601 * check that since we may not have connected yet). 1602 * A is first hop destination, which doesn't appear in 1603 * actual IP option, but is stored before the options. 1604 */ 1605 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1606 goto bad; 1607 1608 offset = cp[IPOPT_OFFSET]; 1609 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1610 sizeof(struct in_addr)); 1611 1612 cp += sizeof(struct in_addr); 1613 cnt -= sizeof(struct in_addr); 1614 olen -= sizeof(struct in_addr); 1615 1616 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1617 goto bad; 1618 1619 memcpy(dp, cp, olen); 1620 dp[IPOPT_OPTVAL] = optval; 1621 dp[IPOPT_OLEN] = olen; 1622 dp[IPOPT_OFFSET] = offset; 1623 break; 1624 } else { 1625 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1626 goto bad; 1627 1628 memcpy(dp, cp, olen); 1629 break; 1630 } 1631 1632 dp += olen; 1633 m->m_len += olen; 1634 1635 if (optval == IPOPT_EOL) 1636 break; 1637 1638 cp += olen; 1639 cnt -= olen; 1640 } 1641 1642 inp->inp_options = m; 1643 return 0; 1644 1645 bad: 1646 (void)m_free(m); 1647 return EINVAL; 1648 } 1649 1650 /* 1651 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1652 * Must be called in a pserialize critical section. 1653 */ 1654 static struct ifnet * 1655 ip_multicast_if(struct in_addr *a, int *ifindexp) 1656 { 1657 int ifindex; 1658 struct ifnet *ifp = NULL; 1659 struct in_ifaddr *ia; 1660 1661 if (ifindexp) 1662 *ifindexp = 0; 1663 if (ntohl(a->s_addr) >> 24 == 0) { 1664 ifindex = ntohl(a->s_addr) & 0xffffff; 1665 ifp = if_byindex(ifindex); 1666 if (!ifp) 1667 return NULL; 1668 if (ifindexp) 1669 *ifindexp = ifindex; 1670 } else { 1671 IN_ADDRHASH_READER_FOREACH(ia, a->s_addr) { 1672 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1673 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1674 ifp = ia->ia_ifp; 1675 if (if_is_deactivated(ifp)) 1676 ifp = NULL; 1677 break; 1678 } 1679 } 1680 } 1681 return ifp; 1682 } 1683 1684 static int 1685 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1686 { 1687 u_int tval; 1688 u_char cval; 1689 int error; 1690 1691 if (sopt == NULL) 1692 return EINVAL; 1693 1694 switch (sopt->sopt_size) { 1695 case sizeof(u_char): 1696 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1697 tval = cval; 1698 break; 1699 1700 case sizeof(u_int): 1701 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1702 break; 1703 1704 default: 1705 error = EINVAL; 1706 } 1707 1708 if (error) 1709 return error; 1710 1711 if (tval > maxval) 1712 return EINVAL; 1713 1714 *val = tval; 1715 return 0; 1716 } 1717 1718 static int 1719 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1720 struct psref *psref, struct in_addr *ia, bool add) 1721 { 1722 int error; 1723 struct ip_mreq mreq; 1724 1725 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1726 if (error) 1727 return error; 1728 1729 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1730 return EINVAL; 1731 1732 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1733 1734 if (in_nullhost(mreq.imr_interface)) { 1735 union { 1736 struct sockaddr dst; 1737 struct sockaddr_in dst4; 1738 } u; 1739 struct route ro; 1740 1741 if (!add) { 1742 *ifp = NULL; 1743 return 0; 1744 } 1745 /* 1746 * If no interface address was provided, use the interface of 1747 * the route to the given multicast address. 1748 */ 1749 struct rtentry *rt; 1750 memset(&ro, 0, sizeof(ro)); 1751 1752 sockaddr_in_init(&u.dst4, ia, 0); 1753 error = rtcache_setdst(&ro, &u.dst); 1754 if (error != 0) 1755 return error; 1756 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1757 if (*ifp != NULL) { 1758 if (if_is_deactivated(*ifp)) 1759 *ifp = NULL; 1760 else 1761 if_acquire(*ifp, psref); 1762 } 1763 rtcache_unref(rt, &ro); 1764 rtcache_free(&ro); 1765 } else { 1766 int s = pserialize_read_enter(); 1767 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1768 if (!add && *ifp == NULL) { 1769 pserialize_read_exit(s); 1770 return EADDRNOTAVAIL; 1771 } 1772 if (*ifp != NULL) { 1773 if (if_is_deactivated(*ifp)) 1774 *ifp = NULL; 1775 else 1776 if_acquire(*ifp, psref); 1777 } 1778 pserialize_read_exit(s); 1779 } 1780 return 0; 1781 } 1782 1783 /* 1784 * Add a multicast group membership. 1785 * Group must be a valid IP multicast address. 1786 */ 1787 static int 1788 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1789 { 1790 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1791 struct in_addr ia; 1792 int i, error, bound; 1793 struct psref psref; 1794 1795 /* imo is protected by solock or referenced only by the caller */ 1796 1797 bound = curlwp_bind(); 1798 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1799 error = ip_get_membership(sopt, &ifp, &psref, &ia, true); 1800 else { 1801 #ifdef INET6 1802 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); 1803 #else 1804 error = EINVAL; 1805 #endif 1806 } 1807 1808 if (error) 1809 goto out; 1810 1811 /* 1812 * See if we found an interface, and confirm that it 1813 * supports multicast. 1814 */ 1815 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1816 error = EADDRNOTAVAIL; 1817 goto out; 1818 } 1819 1820 /* 1821 * See if the membership already exists or if all the 1822 * membership slots are full. 1823 */ 1824 for (i = 0; i < imo->imo_num_memberships; ++i) { 1825 if (imo->imo_membership[i]->inm_ifp == ifp && 1826 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1827 break; 1828 } 1829 if (i < imo->imo_num_memberships) { 1830 error = EADDRINUSE; 1831 goto out; 1832 } 1833 1834 if (i == IP_MAX_MEMBERSHIPS) { 1835 error = ETOOMANYREFS; 1836 goto out; 1837 } 1838 1839 /* 1840 * Everything looks good; add a new record to the multicast 1841 * address list for the given interface. 1842 */ 1843 imo->imo_membership[i] = in_addmulti(&ia, ifp); 1844 if (imo->imo_membership[i] == NULL) { 1845 error = ENOBUFS; 1846 goto out; 1847 } 1848 1849 ++imo->imo_num_memberships; 1850 error = 0; 1851 out: 1852 if_put(ifp, &psref); 1853 curlwp_bindx(bound); 1854 return error; 1855 } 1856 1857 /* 1858 * Drop a multicast group membership. 1859 * Group must be a valid IP multicast address. 1860 */ 1861 static int 1862 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1863 { 1864 struct in_addr ia = { .s_addr = 0 }; // XXX: gcc [ppc] 1865 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1866 int i, error, bound; 1867 struct psref psref; 1868 1869 /* imo is protected by solock or referenced only by the caller */ 1870 1871 bound = curlwp_bind(); 1872 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1873 error = ip_get_membership(sopt, &ifp, &psref, &ia, false); 1874 else { 1875 #ifdef INET6 1876 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); 1877 #else 1878 error = EINVAL; 1879 #endif 1880 } 1881 1882 if (error) 1883 goto out; 1884 1885 /* 1886 * Find the membership in the membership array. 1887 */ 1888 for (i = 0; i < imo->imo_num_memberships; ++i) { 1889 if ((ifp == NULL || 1890 imo->imo_membership[i]->inm_ifp == ifp) && 1891 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1892 break; 1893 } 1894 if (i == imo->imo_num_memberships) { 1895 error = EADDRNOTAVAIL; 1896 goto out; 1897 } 1898 1899 /* 1900 * Give up the multicast address record to which the 1901 * membership points. 1902 */ 1903 in_delmulti(imo->imo_membership[i]); 1904 1905 /* 1906 * Remove the gap in the membership array. 1907 */ 1908 for (++i; i < imo->imo_num_memberships; ++i) 1909 imo->imo_membership[i-1] = imo->imo_membership[i]; 1910 --imo->imo_num_memberships; 1911 error = 0; 1912 out: 1913 if_put(ifp, &psref); 1914 curlwp_bindx(bound); 1915 return error; 1916 } 1917 1918 /* 1919 * Set the IP multicast options in response to user setsockopt(). 1920 */ 1921 int 1922 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1923 { 1924 struct ip_moptions *imo = *pimo; 1925 struct in_addr addr; 1926 struct ifnet *ifp; 1927 int ifindex, error = 0; 1928 1929 /* The passed imo isn't NULL, it should be protected by solock */ 1930 1931 if (!imo) { 1932 /* 1933 * No multicast option buffer attached to the pcb; 1934 * allocate one and initialize to default values. 1935 */ 1936 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1937 if (imo == NULL) 1938 return ENOBUFS; 1939 1940 imo->imo_multicast_if_index = 0; 1941 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1942 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1943 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1944 imo->imo_num_memberships = 0; 1945 *pimo = imo; 1946 } 1947 1948 switch (sopt->sopt_name) { 1949 case IP_MULTICAST_IF: { 1950 int s; 1951 /* 1952 * Select the interface for outgoing multicast packets. 1953 */ 1954 error = sockopt_get(sopt, &addr, sizeof(addr)); 1955 if (error) 1956 break; 1957 1958 /* 1959 * INADDR_ANY is used to remove a previous selection. 1960 * When no interface is selected, a default one is 1961 * chosen every time a multicast packet is sent. 1962 */ 1963 if (in_nullhost(addr)) { 1964 imo->imo_multicast_if_index = 0; 1965 break; 1966 } 1967 /* 1968 * The selected interface is identified by its local 1969 * IP address. Find the interface and confirm that 1970 * it supports multicasting. 1971 */ 1972 s = pserialize_read_enter(); 1973 ifp = ip_multicast_if(&addr, &ifindex); 1974 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1975 pserialize_read_exit(s); 1976 error = EADDRNOTAVAIL; 1977 break; 1978 } 1979 imo->imo_multicast_if_index = ifp->if_index; 1980 pserialize_read_exit(s); 1981 if (ifindex) 1982 imo->imo_multicast_addr = addr; 1983 else 1984 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1985 break; 1986 } 1987 1988 case IP_MULTICAST_TTL: 1989 /* 1990 * Set the IP time-to-live for outgoing multicast packets. 1991 */ 1992 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1993 break; 1994 1995 case IP_MULTICAST_LOOP: 1996 /* 1997 * Set the loopback flag for outgoing multicast packets. 1998 * Must be zero or one. 1999 */ 2000 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 2001 break; 2002 2003 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 2004 error = ip_add_membership(imo, sopt); 2005 break; 2006 2007 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 2008 error = ip_drop_membership(imo, sopt); 2009 break; 2010 2011 default: 2012 error = EOPNOTSUPP; 2013 break; 2014 } 2015 2016 /* 2017 * If all options have default values, no need to keep the mbuf. 2018 */ 2019 if (imo->imo_multicast_if_index == 0 && 2020 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2021 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2022 imo->imo_num_memberships == 0) { 2023 kmem_intr_free(imo, sizeof(*imo)); 2024 *pimo = NULL; 2025 } 2026 2027 return error; 2028 } 2029 2030 /* 2031 * Return the IP multicast options in response to user getsockopt(). 2032 */ 2033 int 2034 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 2035 { 2036 struct in_addr addr; 2037 uint8_t optval; 2038 int error = 0; 2039 2040 /* imo is protected by solock or refereced only by the caller */ 2041 2042 switch (sopt->sopt_name) { 2043 case IP_MULTICAST_IF: 2044 if (imo == NULL || imo->imo_multicast_if_index == 0) 2045 addr = zeroin_addr; 2046 else if (imo->imo_multicast_addr.s_addr) { 2047 /* return the value user has set */ 2048 addr = imo->imo_multicast_addr; 2049 } else { 2050 struct ifnet *ifp; 2051 struct in_ifaddr *ia = NULL; 2052 int s = pserialize_read_enter(); 2053 2054 ifp = if_byindex(imo->imo_multicast_if_index); 2055 if (ifp != NULL) { 2056 ia = in_get_ia_from_ifp(ifp); 2057 } 2058 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 2059 pserialize_read_exit(s); 2060 } 2061 error = sockopt_set(sopt, &addr, sizeof(addr)); 2062 break; 2063 2064 case IP_MULTICAST_TTL: 2065 optval = imo ? imo->imo_multicast_ttl 2066 : IP_DEFAULT_MULTICAST_TTL; 2067 2068 error = sockopt_set(sopt, &optval, sizeof(optval)); 2069 break; 2070 2071 case IP_MULTICAST_LOOP: 2072 optval = imo ? imo->imo_multicast_loop 2073 : IP_DEFAULT_MULTICAST_LOOP; 2074 2075 error = sockopt_set(sopt, &optval, sizeof(optval)); 2076 break; 2077 2078 default: 2079 error = EOPNOTSUPP; 2080 } 2081 2082 return error; 2083 } 2084 2085 /* 2086 * Discard the IP multicast options. 2087 */ 2088 void 2089 ip_freemoptions(struct ip_moptions *imo) 2090 { 2091 int i; 2092 2093 /* The owner of imo (inp) should be protected by solock */ 2094 2095 if (imo != NULL) { 2096 for (i = 0; i < imo->imo_num_memberships; ++i) { 2097 struct in_multi *inm = imo->imo_membership[i]; 2098 in_delmulti(inm); 2099 /* ifp should not leave thanks to solock */ 2100 } 2101 2102 kmem_intr_free(imo, sizeof(*imo)); 2103 } 2104 } 2105 2106 /* 2107 * Routine called from ip_output() to loop back a copy of an IP multicast 2108 * packet to the input queue of a specified interface. Note that this 2109 * calls the output routine of the loopback "driver", but with an interface 2110 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 2111 */ 2112 static void 2113 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 2114 { 2115 struct ip *ip; 2116 struct mbuf *copym; 2117 2118 copym = m_copypacket(m, M_DONTWAIT); 2119 if (copym != NULL && 2120 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 2121 copym = m_pullup(copym, sizeof(struct ip)); 2122 if (copym == NULL) 2123 return; 2124 /* 2125 * We don't bother to fragment if the IP length is greater 2126 * than the interface's MTU. Can this possibly matter? 2127 */ 2128 ip = mtod(copym, struct ip *); 2129 2130 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 2131 in_undefer_cksum_tcpudp(copym); 2132 copym->m_pkthdr.csum_flags &= 2133 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 2134 } 2135 2136 ip->ip_sum = 0; 2137 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 2138 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 2139 (void)looutput(ifp, copym, sintocsa(dst), NULL); 2140 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 2141 } 2142 2143 /* 2144 * Ensure sending address is valid. 2145 * Returns 0 on success, -1 if an error should be sent back or 1 2146 * if the packet could be dropped without error (protocol dependent). 2147 */ 2148 static int 2149 ip_ifaddrvalid(const struct in_ifaddr *ia) 2150 { 2151 2152 if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY) 2153 return 0; 2154 2155 if (ia->ia4_flags & IN_IFF_DUPLICATED) 2156 return -1; 2157 else if (ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DETACHED)) 2158 return 1; 2159 2160 return 0; 2161 } 2162