1 /* $NetBSD: ip_output.c,v 1.319 2020/08/28 17:01:48 christos 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 1.319 2020/08/28 17:01:48 christos 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 IP_STATINC(IP_STAT_RTREJECT); 206 m_freem(m); 207 return error; 208 } 209 } 210 211 error = ip_mark_mpls(ifp, m, rt); 212 if (error != 0) { 213 m_freem(m); 214 return error; 215 } 216 217 error = if_output_lock(ifp, ifp, m, dst, rt); 218 219 return error; 220 } 221 222 /* 223 * IP output. The packet in mbuf chain m contains a skeletal IP 224 * header (with len, off, ttl, proto, tos, src, dst). 225 * The mbuf chain containing the packet will be freed. 226 * The mbuf opt, if present, will not be freed. 227 */ 228 int 229 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 230 struct ip_moptions *imo, struct inpcb *inp) 231 { 232 struct rtentry *rt; 233 struct ip *ip; 234 struct ifnet *ifp, *mifp = NULL; 235 struct mbuf *m = m0; 236 int len, hlen, error = 0; 237 struct route iproute; 238 const struct sockaddr_in *dst; 239 struct in_ifaddr *ia = NULL; 240 struct ifaddr *ifa; 241 int isbroadcast; 242 int sw_csum; 243 u_long mtu; 244 bool natt_frag = false; 245 bool rtmtu_nolock; 246 union { 247 struct sockaddr sa; 248 struct sockaddr_in sin; 249 } udst, usrc; 250 struct sockaddr *rdst = &udst.sa; /* real IP destination, as 251 * opposed to the nexthop 252 */ 253 struct psref psref, psref_ia; 254 int bound; 255 bool bind_need_restore = false; 256 const struct sockaddr *sa; 257 258 len = 0; 259 260 MCLAIM(m, &ip_tx_mowner); 261 262 KASSERT((m->m_flags & M_PKTHDR) != 0); 263 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 264 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 265 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 266 KASSERT(m->m_len >= sizeof(struct ip)); 267 268 hlen = sizeof(struct ip); 269 if (opt) { 270 m = ip_insertoptions(m, opt, &len); 271 hlen = len; 272 } 273 ip = mtod(m, struct ip *); 274 275 /* 276 * Fill in IP header. 277 */ 278 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 279 ip->ip_v = IPVERSION; 280 ip->ip_off = htons(0); 281 /* ip->ip_id filled in after we find out source ia */ 282 ip->ip_hl = hlen >> 2; 283 IP_STATINC(IP_STAT_LOCALOUT); 284 } else { 285 hlen = ip->ip_hl << 2; 286 } 287 288 /* 289 * Route packet. 290 */ 291 if (ro == NULL) { 292 memset(&iproute, 0, sizeof(iproute)); 293 ro = &iproute; 294 } 295 sockaddr_in_init(&udst.sin, &ip->ip_dst, 0); 296 dst = satocsin(rtcache_getdst(ro)); 297 298 /* 299 * If there is a cached route, check that it is to the same 300 * destination and is still up. If not, free it and try again. 301 * The address family should also be checked in case of sharing 302 * the cache with IPv6. 303 */ 304 if (dst && (dst->sin_family != AF_INET || 305 !in_hosteq(dst->sin_addr, ip->ip_dst))) 306 rtcache_free(ro); 307 308 /* XXX must be before rtcache operations */ 309 bound = curlwp_bind(); 310 bind_need_restore = true; 311 312 if ((rt = rtcache_validate(ro)) == NULL && 313 (rt = rtcache_update(ro, 1)) == NULL) { 314 dst = &udst.sin; 315 error = rtcache_setdst(ro, &udst.sa); 316 if (error != 0) { 317 IP_STATINC(IP_STAT_ODROPPED); 318 goto bad; 319 } 320 } 321 322 /* 323 * If routing to interface only, short circuit routing lookup. 324 */ 325 if (flags & IP_ROUTETOIF) { 326 ifa = ifa_ifwithladdr_psref(sintocsa(dst), &psref_ia); 327 if (ifa == NULL) { 328 IP_STATINC(IP_STAT_NOROUTE); 329 error = ENETUNREACH; 330 goto bad; 331 } 332 /* ia is already referenced by psref_ia */ 333 ia = ifatoia(ifa); 334 335 ifp = ia->ia_ifp; 336 mtu = ifp->if_mtu; 337 ip->ip_ttl = 1; 338 isbroadcast = in_broadcast(dst->sin_addr, ifp); 339 } else if (((IN_MULTICAST(ip->ip_dst.s_addr) || 340 ip->ip_dst.s_addr == INADDR_BROADCAST) || 341 (flags & IP_ROUTETOIFINDEX)) && 342 imo != NULL && imo->imo_multicast_if_index != 0) { 343 ifp = mifp = if_get_byindex(imo->imo_multicast_if_index, &psref); 344 if (ifp == NULL) { 345 IP_STATINC(IP_STAT_NOROUTE); 346 error = ENETUNREACH; 347 goto bad; 348 } 349 mtu = ifp->if_mtu; 350 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 351 if (ia == NULL) { 352 IP_STATINC(IP_STAT_IFNOADDR); 353 error = EADDRNOTAVAIL; 354 goto bad; 355 } 356 if (IN_MULTICAST(ip->ip_dst.s_addr) || 357 ip->ip_dst.s_addr == INADDR_BROADCAST) { 358 isbroadcast = 0; 359 } else { 360 /* IP_ROUTETOIFINDEX */ 361 isbroadcast = in_broadcast(dst->sin_addr, ifp); 362 if ((isbroadcast == 0) && ((ifp->if_flags & 363 (IFF_LOOPBACK | IFF_POINTOPOINT)) == 0) && 364 (in_direct(dst->sin_addr, ifp) == 0)) { 365 /* gateway address required */ 366 if (rt == NULL) 367 rt = rtcache_init(ro); 368 if (rt == NULL || rt->rt_ifp != ifp) { 369 IP_STATINC(IP_STAT_NOROUTE); 370 error = EHOSTUNREACH; 371 goto bad; 372 } 373 rt->rt_use++; 374 if (rt->rt_flags & RTF_GATEWAY) 375 dst = satosin(rt->rt_gateway); 376 if (rt->rt_flags & RTF_HOST) 377 isbroadcast = 378 rt->rt_flags & RTF_BROADCAST; 379 } 380 } 381 } else { 382 if (rt == NULL) 383 rt = rtcache_init(ro); 384 if (rt == NULL) { 385 IP_STATINC(IP_STAT_NOROUTE); 386 error = EHOSTUNREACH; 387 goto bad; 388 } 389 if (ifa_is_destroying(rt->rt_ifa)) { 390 rtcache_unref(rt, ro); 391 rt = NULL; 392 IP_STATINC(IP_STAT_NOROUTE); 393 error = EHOSTUNREACH; 394 goto bad; 395 } 396 ifa_acquire(rt->rt_ifa, &psref_ia); 397 ia = ifatoia(rt->rt_ifa); 398 ifp = rt->rt_ifp; 399 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 400 mtu = ifp->if_mtu; 401 rt->rt_use++; 402 if (rt->rt_flags & RTF_GATEWAY) 403 dst = satosin(rt->rt_gateway); 404 if (rt->rt_flags & RTF_HOST) 405 isbroadcast = rt->rt_flags & RTF_BROADCAST; 406 else 407 isbroadcast = in_broadcast(dst->sin_addr, ifp); 408 } 409 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 410 411 if (IN_MULTICAST(ip->ip_dst.s_addr) || 412 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 413 bool inmgroup; 414 415 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 416 M_BCAST : M_MCAST; 417 /* 418 * See if the caller provided any multicast options 419 */ 420 if (imo != NULL) 421 ip->ip_ttl = imo->imo_multicast_ttl; 422 else 423 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 424 425 /* 426 * if we don't know the outgoing ifp yet, we can't generate 427 * output 428 */ 429 if (!ifp) { 430 IP_STATINC(IP_STAT_NOROUTE); 431 error = ENETUNREACH; 432 goto bad; 433 } 434 435 /* 436 * If the packet is multicast or broadcast, confirm that 437 * the outgoing interface can transmit it. 438 */ 439 if (((m->m_flags & M_MCAST) && 440 (ifp->if_flags & IFF_MULTICAST) == 0) || 441 ((m->m_flags & M_BCAST) && 442 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 443 IP_STATINC(IP_STAT_NOROUTE); 444 error = ENETUNREACH; 445 goto bad; 446 } 447 /* 448 * If source address not specified yet, use an address 449 * of outgoing interface. 450 */ 451 if (in_nullhost(ip->ip_src)) { 452 struct in_ifaddr *xia; 453 struct ifaddr *xifa; 454 struct psref _psref; 455 456 xia = in_get_ia_from_ifp_psref(ifp, &_psref); 457 if (!xia) { 458 IP_STATINC(IP_STAT_IFNOADDR); 459 error = EADDRNOTAVAIL; 460 goto bad; 461 } 462 xifa = &xia->ia_ifa; 463 if (xifa->ifa_getifa != NULL) { 464 ia4_release(xia, &_psref); 465 /* FIXME ifa_getifa is NOMPSAFE */ 466 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 467 if (xia == NULL) { 468 IP_STATINC(IP_STAT_IFNOADDR); 469 error = EADDRNOTAVAIL; 470 goto bad; 471 } 472 ia4_acquire(xia, &_psref); 473 } 474 ip->ip_src = xia->ia_addr.sin_addr; 475 ia4_release(xia, &_psref); 476 } 477 478 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 479 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 480 /* 481 * If we belong to the destination multicast group 482 * on the outgoing interface, and the caller did not 483 * forbid loopback, loop back a copy. 484 */ 485 ip_mloopback(ifp, m, &udst.sin); 486 } 487 #ifdef MROUTING 488 else { 489 /* 490 * If we are acting as a multicast router, perform 491 * multicast forwarding as if the packet had just 492 * arrived on the interface to which we are about 493 * to send. The multicast forwarding function 494 * recursively calls this function, using the 495 * IP_FORWARDING flag to prevent infinite recursion. 496 * 497 * Multicasts that are looped back by ip_mloopback(), 498 * above, will be forwarded by the ip_input() routine, 499 * if necessary. 500 */ 501 extern struct socket *ip_mrouter; 502 503 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 504 if (ip_mforward(m, ifp) != 0) { 505 m_freem(m); 506 goto done; 507 } 508 } 509 } 510 #endif 511 /* 512 * Multicasts with a time-to-live of zero may be looped- 513 * back, above, but must not be transmitted on a network. 514 * Also, multicasts addressed to the loopback interface 515 * are not sent -- the above call to ip_mloopback() will 516 * loop back a copy if this host actually belongs to the 517 * destination group on the loopback interface. 518 */ 519 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 520 IP_STATINC(IP_STAT_ODROPPED); 521 m_freem(m); 522 goto done; 523 } 524 goto sendit; 525 } 526 527 /* 528 * If source address not specified yet, use address 529 * of outgoing interface. 530 */ 531 if (in_nullhost(ip->ip_src)) { 532 struct ifaddr *xifa; 533 534 xifa = &ia->ia_ifa; 535 if (xifa->ifa_getifa != NULL) { 536 ia4_release(ia, &psref_ia); 537 /* FIXME ifa_getifa is NOMPSAFE */ 538 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 539 if (ia == NULL) { 540 error = EADDRNOTAVAIL; 541 goto bad; 542 } 543 ia4_acquire(ia, &psref_ia); 544 } 545 ip->ip_src = ia->ia_addr.sin_addr; 546 } 547 548 /* 549 * Packets with Class-D address as source are not valid per 550 * RFC1112. 551 */ 552 if (IN_MULTICAST(ip->ip_src.s_addr)) { 553 IP_STATINC(IP_STAT_ODROPPED); 554 error = EADDRNOTAVAIL; 555 goto bad; 556 } 557 558 /* 559 * Look for broadcast address and verify user is allowed to 560 * send such a packet. 561 */ 562 if (isbroadcast) { 563 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 564 IP_STATINC(IP_STAT_BCASTDENIED); 565 error = EADDRNOTAVAIL; 566 goto bad; 567 } 568 if ((flags & IP_ALLOWBROADCAST) == 0) { 569 IP_STATINC(IP_STAT_BCASTDENIED); 570 error = EACCES; 571 goto bad; 572 } 573 /* don't allow broadcast messages to be fragmented */ 574 if (ntohs(ip->ip_len) > ifp->if_mtu) { 575 IP_STATINC(IP_STAT_BCASTDENIED); 576 error = EMSGSIZE; 577 goto bad; 578 } 579 m->m_flags |= M_BCAST; 580 } else 581 m->m_flags &= ~M_BCAST; 582 583 sendit: 584 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 585 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 586 ip->ip_id = 0; 587 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 588 ip->ip_id = ip_newid(ia); 589 } else { 590 /* 591 * TSO capable interfaces (typically?) increment 592 * ip_id for each segment. 593 * "allocate" enough ids here to increase the chance 594 * for them to be unique. 595 * 596 * note that the following calculation is not 597 * needed to be precise. wasting some ip_id is fine. 598 */ 599 600 unsigned int segsz = m->m_pkthdr.segsz; 601 unsigned int datasz = ntohs(ip->ip_len) - hlen; 602 unsigned int num = howmany(datasz, segsz); 603 604 ip->ip_id = ip_newid_range(ia, num); 605 } 606 } 607 if (ia != NULL) { 608 ia4_release(ia, &psref_ia); 609 ia = NULL; 610 } 611 612 /* 613 * If we're doing Path MTU Discovery, we need to set DF unless 614 * the route's MTU is locked. 615 */ 616 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 617 ip->ip_off |= htons(IP_DF); 618 } 619 620 #ifdef IPSEC 621 if (ipsec_used) { 622 bool ipsec_done = false; 623 bool count_drop = false; 624 625 /* Perform IPsec processing, if any. */ 626 error = ipsec4_output(m, inp, flags, &mtu, &natt_frag, 627 &ipsec_done, &count_drop); 628 if (count_drop) 629 IP_STATINC(IP_STAT_IPSECDROP_OUT); 630 if (error || ipsec_done) 631 goto done; 632 } 633 634 if (!ipsec_used || !natt_frag) 635 #endif 636 { 637 /* 638 * Run through list of hooks for output packets. 639 */ 640 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 641 if (error || m == NULL) { 642 IP_STATINC(IP_STAT_PFILDROP_OUT); 643 goto done; 644 } 645 } 646 647 ip = mtod(m, struct ip *); 648 hlen = ip->ip_hl << 2; 649 650 m->m_pkthdr.csum_data |= hlen << 16; 651 652 /* 653 * search for the source address structure to 654 * maintain output statistics, and verify address 655 * validity 656 */ 657 KASSERT(ia == NULL); 658 sockaddr_in_init(&usrc.sin, &ip->ip_src, 0); 659 ifa = ifaof_ifpforaddr_psref(&usrc.sa, ifp, &psref_ia); 660 if (ifa != NULL) 661 ia = ifatoia(ifa); 662 663 /* 664 * Ensure we only send from a valid address. 665 * A NULL address is valid because the packet could be 666 * generated from a packet filter. 667 */ 668 if (ia != NULL && (flags & IP_FORWARDING) == 0 && 669 (error = ip_ifaddrvalid(ia)) != 0) 670 { 671 ARPLOG(LOG_ERR, 672 "refusing to send from invalid address %s (pid %d)\n", 673 ARPLOGADDR(&ip->ip_src), curproc->p_pid); 674 IP_STATINC(IP_STAT_ODROPPED); 675 if (error == 1) 676 /* 677 * Address exists, but is tentative or detached. 678 * We can't send from it because it's invalid, 679 * so we drop the packet. 680 */ 681 error = 0; 682 else 683 error = EADDRNOTAVAIL; 684 goto bad; 685 } 686 687 /* Maybe skip checksums on loopback interfaces. */ 688 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 689 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 690 } 691 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 692 693 /* Need to fragment the packet */ 694 if (ntohs(ip->ip_len) > mtu && 695 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 696 goto fragment; 697 } 698 699 #if IFA_STATS 700 if (ia) 701 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 702 #endif 703 /* 704 * Always initialize the sum to 0! Some HW assisted 705 * checksumming requires this. 706 */ 707 ip->ip_sum = 0; 708 709 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 710 /* 711 * Perform any checksums that the hardware can't do 712 * for us. 713 * 714 * XXX Does any hardware require the {th,uh}_sum 715 * XXX fields to be 0? 716 */ 717 if (sw_csum & M_CSUM_IPv4) { 718 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 719 ip->ip_sum = in_cksum(m, hlen); 720 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 721 } 722 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 723 if (IN_NEED_CHECKSUM(ifp, 724 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 725 in_undefer_cksum_tcpudp(m); 726 } 727 m->m_pkthdr.csum_flags &= 728 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 729 } 730 } 731 732 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 733 734 /* Send it */ 735 if (__predict_false(sw_csum & M_CSUM_TSOv4)) { 736 /* 737 * TSO4 is required by a packet, but disabled for 738 * the interface. 739 */ 740 error = ip_tso_output(ifp, m, sa, rt); 741 } else 742 error = ip_if_output(ifp, m, sa, rt); 743 goto done; 744 745 fragment: 746 /* 747 * We can't use HW checksumming if we're about to fragment the packet. 748 * 749 * XXX Some hardware can do this. 750 */ 751 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 752 if (IN_NEED_CHECKSUM(ifp, 753 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 754 in_undefer_cksum_tcpudp(m); 755 } 756 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 757 } 758 759 /* 760 * Too large for interface; fragment if possible. 761 * Must be able to put at least 8 bytes per fragment. 762 */ 763 if (ntohs(ip->ip_off) & IP_DF) { 764 if (flags & IP_RETURNMTU) { 765 KASSERT(inp != NULL); 766 inp->inp_errormtu = mtu; 767 } 768 error = EMSGSIZE; 769 IP_STATINC(IP_STAT_CANTFRAG); 770 goto bad; 771 } 772 773 error = ip_fragment(m, ifp, mtu); 774 if (error) { 775 m = NULL; 776 goto bad; 777 } 778 779 for (; m; m = m0) { 780 m0 = m->m_nextpkt; 781 m->m_nextpkt = NULL; 782 if (error) { 783 m_freem(m); 784 continue; 785 } 786 #if IFA_STATS 787 if (ia) 788 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 789 #endif 790 /* 791 * If we get there, the packet has not been handled by 792 * IPsec whereas it should have. Now that it has been 793 * fragmented, re-inject it in ip_output so that IPsec 794 * processing can occur. 795 */ 796 if (natt_frag) { 797 error = ip_output(m, opt, NULL, 798 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 799 imo, inp); 800 } else { 801 KASSERT((m->m_pkthdr.csum_flags & 802 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 803 error = ip_if_output(ifp, m, (m->m_flags & M_MCAST) ? 804 sintocsa(rdst) : sintocsa(dst), rt); 805 } 806 } 807 if (error == 0) { 808 IP_STATINC(IP_STAT_FRAGMENTED); 809 } 810 811 done: 812 ia4_release(ia, &psref_ia); 813 rtcache_unref(rt, ro); 814 if (ro == &iproute) { 815 rtcache_free(&iproute); 816 } 817 if (mifp != NULL) { 818 if_put(mifp, &psref); 819 } 820 if (bind_need_restore) 821 curlwp_bindx(bound); 822 return error; 823 824 bad: 825 m_freem(m); 826 goto done; 827 } 828 829 int 830 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 831 { 832 struct ip *ip, *mhip; 833 struct mbuf *m0; 834 int len, hlen, off; 835 int mhlen, firstlen; 836 struct mbuf **mnext; 837 int sw_csum = m->m_pkthdr.csum_flags; 838 int fragments = 0; 839 int error = 0; 840 int ipoff, ipflg; 841 842 ip = mtod(m, struct ip *); 843 hlen = ip->ip_hl << 2; 844 845 /* Preserve the offset and flags. */ 846 ipoff = ntohs(ip->ip_off) & IP_OFFMASK; 847 ipflg = ntohs(ip->ip_off) & (IP_RF|IP_DF|IP_MF); 848 849 if (ifp != NULL) 850 sw_csum &= ~ifp->if_csum_flags_tx; 851 852 len = (mtu - hlen) &~ 7; 853 if (len < 8) { 854 IP_STATINC(IP_STAT_CANTFRAG); 855 m_freem(m); 856 return EMSGSIZE; 857 } 858 859 firstlen = len; 860 mnext = &m->m_nextpkt; 861 862 /* 863 * Loop through length of segment after first fragment, 864 * make new header and copy data of each part and link onto chain. 865 */ 866 m0 = m; 867 mhlen = sizeof(struct ip); 868 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 869 MGETHDR(m, M_DONTWAIT, MT_HEADER); 870 if (m == NULL) { 871 error = ENOBUFS; 872 IP_STATINC(IP_STAT_ODROPPED); 873 goto sendorfree; 874 } 875 MCLAIM(m, m0->m_owner); 876 877 *mnext = m; 878 mnext = &m->m_nextpkt; 879 880 m->m_data += max_linkhdr; 881 mhip = mtod(m, struct ip *); 882 *mhip = *ip; 883 884 /* we must inherit the flags */ 885 m->m_flags |= m0->m_flags & M_COPYFLAGS; 886 887 if (hlen > sizeof(struct ip)) { 888 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip); 889 mhip->ip_hl = mhlen >> 2; 890 } 891 m->m_len = mhlen; 892 893 mhip->ip_off = ((off - hlen) >> 3) + ipoff; 894 mhip->ip_off |= ipflg; 895 if (off + len >= ntohs(ip->ip_len)) 896 len = ntohs(ip->ip_len) - off; 897 else 898 mhip->ip_off |= IP_MF; 899 HTONS(mhip->ip_off); 900 901 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 902 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 903 if (m->m_next == NULL) { 904 error = ENOBUFS; 905 IP_STATINC(IP_STAT_ODROPPED); 906 goto sendorfree; 907 } 908 909 m->m_pkthdr.len = mhlen + len; 910 m_reset_rcvif(m); 911 912 mhip->ip_sum = 0; 913 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 914 if (sw_csum & M_CSUM_IPv4) { 915 mhip->ip_sum = in_cksum(m, mhlen); 916 } else { 917 /* 918 * checksum is hw-offloaded or not necessary. 919 */ 920 m->m_pkthdr.csum_flags |= 921 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 922 m->m_pkthdr.csum_data |= mhlen << 16; 923 KASSERT(!(ifp != NULL && 924 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 925 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 926 } 927 IP_STATINC(IP_STAT_OFRAGMENTS); 928 fragments++; 929 } 930 931 /* 932 * Update first fragment by trimming what's been copied out 933 * and updating header, then send each fragment (in order). 934 */ 935 m = m0; 936 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 937 m->m_pkthdr.len = hlen + firstlen; 938 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 939 ip->ip_off |= htons(IP_MF); 940 ip->ip_sum = 0; 941 if (sw_csum & M_CSUM_IPv4) { 942 ip->ip_sum = in_cksum(m, hlen); 943 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 944 } else { 945 /* 946 * checksum is hw-offloaded or not necessary. 947 */ 948 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 949 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 950 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 951 sizeof(struct ip)); 952 } 953 954 sendorfree: 955 /* 956 * If there is no room for all the fragments, don't queue 957 * any of them. 958 */ 959 if (ifp != NULL) { 960 IFQ_LOCK(&ifp->if_snd); 961 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 962 error == 0) { 963 error = ENOBUFS; 964 IP_STATINC(IP_STAT_ODROPPED); 965 IFQ_INC_DROPS(&ifp->if_snd); 966 } 967 IFQ_UNLOCK(&ifp->if_snd); 968 } 969 if (error) { 970 for (m = m0; m; m = m0) { 971 m0 = m->m_nextpkt; 972 m->m_nextpkt = NULL; 973 m_freem(m); 974 } 975 } 976 977 return error; 978 } 979 980 /* 981 * Determine the maximum length of the options to be inserted; 982 * we would far rather allocate too much space rather than too little. 983 */ 984 u_int 985 ip_optlen(struct inpcb *inp) 986 { 987 struct mbuf *m = inp->inp_options; 988 989 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 990 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 991 } 992 return 0; 993 } 994 995 /* 996 * Insert IP options into preformed packet. 997 * Adjust IP destination as required for IP source routing, 998 * as indicated by a non-zero in_addr at the start of the options. 999 */ 1000 static struct mbuf * 1001 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1002 { 1003 struct ipoption *p = mtod(opt, struct ipoption *); 1004 struct mbuf *n; 1005 struct ip *ip = mtod(m, struct ip *); 1006 unsigned optlen; 1007 1008 optlen = opt->m_len - sizeof(p->ipopt_dst); 1009 KASSERT(optlen % 4 == 0); 1010 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 1011 return m; /* XXX should fail */ 1012 if (!in_nullhost(p->ipopt_dst)) 1013 ip->ip_dst = p->ipopt_dst; 1014 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1015 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1016 if (n == NULL) 1017 return m; 1018 MCLAIM(n, m->m_owner); 1019 m_move_pkthdr(n, m); 1020 m->m_len -= sizeof(struct ip); 1021 m->m_data += sizeof(struct ip); 1022 n->m_next = m; 1023 n->m_len = optlen + sizeof(struct ip); 1024 n->m_data += max_linkhdr; 1025 memcpy(mtod(n, void *), ip, sizeof(struct ip)); 1026 m = n; 1027 } else { 1028 m->m_data -= optlen; 1029 m->m_len += optlen; 1030 memmove(mtod(m, void *), ip, sizeof(struct ip)); 1031 } 1032 m->m_pkthdr.len += optlen; 1033 ip = mtod(m, struct ip *); 1034 memcpy(ip + 1, p->ipopt_list, optlen); 1035 *phlen = sizeof(struct ip) + optlen; 1036 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1037 return m; 1038 } 1039 1040 /* 1041 * Copy options from ipsrc to ipdst, omitting those not copied during 1042 * fragmentation. 1043 */ 1044 int 1045 ip_optcopy(struct ip *ipsrc, struct ip *ipdst) 1046 { 1047 u_char *cp, *dp; 1048 int opt, optlen, cnt; 1049 1050 cp = (u_char *)(ipsrc + 1); 1051 dp = (u_char *)(ipdst + 1); 1052 cnt = (ipsrc->ip_hl << 2) - sizeof(struct ip); 1053 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1054 opt = cp[0]; 1055 if (opt == IPOPT_EOL) 1056 break; 1057 if (opt == IPOPT_NOP) { 1058 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1059 *dp++ = IPOPT_NOP; 1060 optlen = 1; 1061 continue; 1062 } 1063 1064 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 1065 optlen = cp[IPOPT_OLEN]; 1066 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 1067 1068 /* Invalid lengths should have been caught by ip_dooptions. */ 1069 if (optlen > cnt) 1070 optlen = cnt; 1071 if (IPOPT_COPIED(opt)) { 1072 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 1073 dp += optlen; 1074 } 1075 } 1076 1077 for (optlen = dp - (u_char *)(ipdst+1); optlen & 0x3; optlen++) { 1078 *dp++ = IPOPT_EOL; 1079 } 1080 1081 return optlen; 1082 } 1083 1084 /* 1085 * IP socket option processing. 1086 */ 1087 int 1088 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 1089 { 1090 struct inpcb *inp = sotoinpcb(so); 1091 struct ip *ip = &inp->inp_ip; 1092 int inpflags = inp->inp_flags; 1093 int optval = 0, error = 0; 1094 struct in_pktinfo pktinfo; 1095 1096 KASSERT(solocked(so)); 1097 1098 if (sopt->sopt_level != IPPROTO_IP) { 1099 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1100 return 0; 1101 return ENOPROTOOPT; 1102 } 1103 1104 switch (op) { 1105 case PRCO_SETOPT: 1106 switch (sopt->sopt_name) { 1107 case IP_OPTIONS: 1108 #ifdef notyet 1109 case IP_RETOPTS: 1110 #endif 1111 error = ip_pcbopts(inp, sopt); 1112 break; 1113 1114 case IP_TOS: 1115 case IP_TTL: 1116 case IP_MINTTL: 1117 case IP_RECVOPTS: 1118 case IP_RECVRETOPTS: 1119 case IP_RECVDSTADDR: 1120 case IP_RECVIF: 1121 case IP_RECVPKTINFO: 1122 case IP_RECVTTL: 1123 error = sockopt_getint(sopt, &optval); 1124 if (error) 1125 break; 1126 1127 switch (sopt->sopt_name) { 1128 case IP_TOS: 1129 ip->ip_tos = optval; 1130 break; 1131 1132 case IP_TTL: 1133 ip->ip_ttl = optval; 1134 break; 1135 1136 case IP_MINTTL: 1137 if (optval > 0 && optval <= MAXTTL) 1138 inp->inp_ip_minttl = optval; 1139 else 1140 error = EINVAL; 1141 break; 1142 #define OPTSET(bit) \ 1143 if (optval) \ 1144 inpflags |= bit; \ 1145 else \ 1146 inpflags &= ~bit; 1147 1148 case IP_RECVOPTS: 1149 OPTSET(INP_RECVOPTS); 1150 break; 1151 1152 case IP_RECVPKTINFO: 1153 OPTSET(INP_RECVPKTINFO); 1154 break; 1155 1156 case IP_RECVRETOPTS: 1157 OPTSET(INP_RECVRETOPTS); 1158 break; 1159 1160 case IP_RECVDSTADDR: 1161 OPTSET(INP_RECVDSTADDR); 1162 break; 1163 1164 case IP_RECVIF: 1165 OPTSET(INP_RECVIF); 1166 break; 1167 1168 case IP_RECVTTL: 1169 OPTSET(INP_RECVTTL); 1170 break; 1171 } 1172 break; 1173 case IP_PKTINFO: 1174 error = sockopt_getint(sopt, &optval); 1175 if (!error) { 1176 /* Linux compatibility */ 1177 OPTSET(INP_RECVPKTINFO); 1178 break; 1179 } 1180 error = sockopt_get(sopt, &pktinfo, sizeof(pktinfo)); 1181 if (error) 1182 break; 1183 1184 if (pktinfo.ipi_ifindex == 0) { 1185 inp->inp_prefsrcip = pktinfo.ipi_addr; 1186 break; 1187 } 1188 1189 /* Solaris compatibility */ 1190 struct ifnet *ifp; 1191 struct in_ifaddr *ia; 1192 int s; 1193 1194 /* pick up primary address */ 1195 s = pserialize_read_enter(); 1196 ifp = if_byindex(pktinfo.ipi_ifindex); 1197 if (ifp == NULL) { 1198 pserialize_read_exit(s); 1199 error = EADDRNOTAVAIL; 1200 break; 1201 } 1202 ia = in_get_ia_from_ifp(ifp); 1203 if (ia == NULL) { 1204 pserialize_read_exit(s); 1205 error = EADDRNOTAVAIL; 1206 break; 1207 } 1208 inp->inp_prefsrcip = IA_SIN(ia)->sin_addr; 1209 pserialize_read_exit(s); 1210 break; 1211 break; 1212 #undef OPTSET 1213 1214 case IP_MULTICAST_IF: 1215 case IP_MULTICAST_TTL: 1216 case IP_MULTICAST_LOOP: 1217 case IP_ADD_MEMBERSHIP: 1218 case IP_DROP_MEMBERSHIP: 1219 error = ip_setmoptions(&inp->inp_moptions, sopt); 1220 break; 1221 1222 case IP_PORTRANGE: 1223 error = sockopt_getint(sopt, &optval); 1224 if (error) 1225 break; 1226 1227 switch (optval) { 1228 case IP_PORTRANGE_DEFAULT: 1229 case IP_PORTRANGE_HIGH: 1230 inpflags &= ~(INP_LOWPORT); 1231 break; 1232 1233 case IP_PORTRANGE_LOW: 1234 inpflags |= INP_LOWPORT; 1235 break; 1236 1237 default: 1238 error = EINVAL; 1239 break; 1240 } 1241 break; 1242 1243 case IP_PORTALGO: 1244 error = sockopt_getint(sopt, &optval); 1245 if (error) 1246 break; 1247 1248 error = portalgo_algo_index_select( 1249 (struct inpcb_hdr *)inp, optval); 1250 break; 1251 1252 #if defined(IPSEC) 1253 case IP_IPSEC_POLICY: 1254 if (ipsec_enabled) { 1255 error = ipsec_set_policy(inp, 1256 sopt->sopt_data, sopt->sopt_size, 1257 curlwp->l_cred); 1258 } else 1259 error = ENOPROTOOPT; 1260 break; 1261 #endif /* IPSEC */ 1262 1263 default: 1264 error = ENOPROTOOPT; 1265 break; 1266 } 1267 break; 1268 1269 case PRCO_GETOPT: 1270 switch (sopt->sopt_name) { 1271 case IP_OPTIONS: 1272 case IP_RETOPTS: { 1273 struct mbuf *mopts = inp->inp_options; 1274 1275 if (mopts) { 1276 struct mbuf *m; 1277 1278 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1279 if (m == NULL) { 1280 error = ENOBUFS; 1281 break; 1282 } 1283 error = sockopt_setmbuf(sopt, m); 1284 } 1285 break; 1286 } 1287 case IP_TOS: 1288 case IP_TTL: 1289 case IP_MINTTL: 1290 case IP_RECVOPTS: 1291 case IP_RECVRETOPTS: 1292 case IP_RECVDSTADDR: 1293 case IP_RECVIF: 1294 case IP_RECVPKTINFO: 1295 case IP_RECVTTL: 1296 case IP_ERRORMTU: 1297 switch (sopt->sopt_name) { 1298 case IP_TOS: 1299 optval = ip->ip_tos; 1300 break; 1301 1302 case IP_TTL: 1303 optval = ip->ip_ttl; 1304 break; 1305 1306 case IP_MINTTL: 1307 optval = inp->inp_ip_minttl; 1308 break; 1309 1310 case IP_ERRORMTU: 1311 optval = inp->inp_errormtu; 1312 break; 1313 1314 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1315 1316 case IP_RECVOPTS: 1317 optval = OPTBIT(INP_RECVOPTS); 1318 break; 1319 1320 case IP_RECVPKTINFO: 1321 optval = OPTBIT(INP_RECVPKTINFO); 1322 break; 1323 1324 case IP_RECVRETOPTS: 1325 optval = OPTBIT(INP_RECVRETOPTS); 1326 break; 1327 1328 case IP_RECVDSTADDR: 1329 optval = OPTBIT(INP_RECVDSTADDR); 1330 break; 1331 1332 case IP_RECVIF: 1333 optval = OPTBIT(INP_RECVIF); 1334 break; 1335 1336 case IP_RECVTTL: 1337 optval = OPTBIT(INP_RECVTTL); 1338 break; 1339 } 1340 error = sockopt_setint(sopt, optval); 1341 break; 1342 1343 case IP_PKTINFO: 1344 switch (sopt->sopt_size) { 1345 case sizeof(int): 1346 /* Linux compatibility */ 1347 optval = OPTBIT(INP_RECVPKTINFO); 1348 error = sockopt_setint(sopt, optval); 1349 break; 1350 case sizeof(struct in_pktinfo): 1351 /* Solaris compatibility */ 1352 pktinfo.ipi_ifindex = 0; 1353 pktinfo.ipi_addr = inp->inp_prefsrcip; 1354 error = sockopt_set(sopt, &pktinfo, 1355 sizeof(pktinfo)); 1356 break; 1357 default: 1358 /* 1359 * While size is stuck at 0, and, later, if 1360 * the caller doesn't use an exactly sized 1361 * recipient for the data, default to Linux 1362 * compatibility 1363 */ 1364 optval = OPTBIT(INP_RECVPKTINFO); 1365 error = sockopt_setint(sopt, optval); 1366 break; 1367 } 1368 break; 1369 1370 #if 0 /* defined(IPSEC) */ 1371 case IP_IPSEC_POLICY: 1372 { 1373 struct mbuf *m = NULL; 1374 1375 /* XXX this will return EINVAL as sopt is empty */ 1376 error = ipsec_get_policy(inp, sopt->sopt_data, 1377 sopt->sopt_size, &m); 1378 if (error == 0) 1379 error = sockopt_setmbuf(sopt, m); 1380 break; 1381 } 1382 #endif /*IPSEC*/ 1383 1384 case IP_MULTICAST_IF: 1385 case IP_MULTICAST_TTL: 1386 case IP_MULTICAST_LOOP: 1387 case IP_ADD_MEMBERSHIP: 1388 case IP_DROP_MEMBERSHIP: 1389 error = ip_getmoptions(inp->inp_moptions, sopt); 1390 break; 1391 1392 case IP_PORTRANGE: 1393 if (inpflags & INP_LOWPORT) 1394 optval = IP_PORTRANGE_LOW; 1395 else 1396 optval = IP_PORTRANGE_DEFAULT; 1397 error = sockopt_setint(sopt, optval); 1398 break; 1399 1400 case IP_PORTALGO: 1401 optval = inp->inp_portalgo; 1402 error = sockopt_setint(sopt, optval); 1403 break; 1404 1405 default: 1406 error = ENOPROTOOPT; 1407 break; 1408 } 1409 break; 1410 } 1411 1412 if (!error) { 1413 inp->inp_flags = inpflags; 1414 } 1415 return error; 1416 } 1417 1418 static int 1419 ip_pktinfo_prepare(const struct in_pktinfo *pktinfo, struct ip_pktopts *pktopts, 1420 int *flags, kauth_cred_t cred) 1421 { 1422 struct ip_moptions *imo; 1423 int error = 0; 1424 bool addrset = false; 1425 1426 if (!in_nullhost(pktinfo->ipi_addr)) { 1427 pktopts->ippo_laddr.sin_addr = pktinfo->ipi_addr; 1428 /* EADDRNOTAVAIL? */ 1429 error = in_pcbbindableaddr(&pktopts->ippo_laddr, cred); 1430 if (error != 0) 1431 return error; 1432 addrset = true; 1433 } 1434 1435 if (pktinfo->ipi_ifindex != 0) { 1436 if (!addrset) { 1437 struct ifnet *ifp; 1438 struct in_ifaddr *ia; 1439 int s; 1440 1441 /* pick up primary address */ 1442 s = pserialize_read_enter(); 1443 ifp = if_byindex(pktinfo->ipi_ifindex); 1444 if (ifp == NULL) { 1445 pserialize_read_exit(s); 1446 return EADDRNOTAVAIL; 1447 } 1448 ia = in_get_ia_from_ifp(ifp); 1449 if (ia == NULL) { 1450 pserialize_read_exit(s); 1451 return EADDRNOTAVAIL; 1452 } 1453 pktopts->ippo_laddr.sin_addr = IA_SIN(ia)->sin_addr; 1454 pserialize_read_exit(s); 1455 } 1456 1457 /* 1458 * If specified ipi_ifindex, 1459 * use copied or locally initialized ip_moptions. 1460 * Original ip_moptions must not be modified. 1461 */ 1462 imo = &pktopts->ippo_imobuf; /* local buf in pktopts */ 1463 if (pktopts->ippo_imo != NULL) { 1464 memcpy(imo, pktopts->ippo_imo, sizeof(*imo)); 1465 } else { 1466 memset(imo, 0, sizeof(*imo)); 1467 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1468 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1469 } 1470 imo->imo_multicast_if_index = pktinfo->ipi_ifindex; 1471 pktopts->ippo_imo = imo; 1472 *flags |= IP_ROUTETOIFINDEX; 1473 } 1474 return error; 1475 } 1476 1477 /* 1478 * Set up IP outgoing packet options. Even if control is NULL, 1479 * pktopts->ippo_laddr and pktopts->ippo_imo are set and used. 1480 */ 1481 int 1482 ip_setpktopts(struct mbuf *control, struct ip_pktopts *pktopts, int *flags, 1483 struct inpcb *inp, kauth_cred_t cred) 1484 { 1485 struct cmsghdr *cm; 1486 struct in_pktinfo pktinfo; 1487 int error; 1488 1489 pktopts->ippo_imo = inp->inp_moptions; 1490 1491 struct in_addr *ia = in_nullhost(inp->inp_prefsrcip) ? &inp->inp_laddr : 1492 &inp->inp_prefsrcip; 1493 sockaddr_in_init(&pktopts->ippo_laddr, ia, 0); 1494 1495 if (control == NULL) 1496 return 0; 1497 1498 /* 1499 * XXX: Currently, we assume all the optional information is 1500 * stored in a single mbuf. 1501 */ 1502 if (control->m_next) 1503 return EINVAL; 1504 1505 for (; control->m_len > 0; 1506 control->m_data += CMSG_ALIGN(cm->cmsg_len), 1507 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) { 1508 cm = mtod(control, struct cmsghdr *); 1509 if ((control->m_len < sizeof(*cm)) || 1510 (cm->cmsg_len == 0) || 1511 (cm->cmsg_len > control->m_len)) { 1512 return EINVAL; 1513 } 1514 if (cm->cmsg_level != IPPROTO_IP) 1515 continue; 1516 1517 switch (cm->cmsg_type) { 1518 case IP_PKTINFO: 1519 if (cm->cmsg_len != CMSG_LEN(sizeof(pktinfo))) 1520 return EINVAL; 1521 memcpy(&pktinfo, CMSG_DATA(cm), sizeof(pktinfo)); 1522 error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, 1523 cred); 1524 if (error) 1525 return error; 1526 break; 1527 case IP_SENDSRCADDR: /* FreeBSD compatibility */ 1528 if (cm->cmsg_len != CMSG_LEN(sizeof(struct in_addr))) 1529 return EINVAL; 1530 pktinfo.ipi_ifindex = 0; 1531 pktinfo.ipi_addr = 1532 ((struct in_pktinfo *)CMSG_DATA(cm))->ipi_addr; 1533 error = ip_pktinfo_prepare(&pktinfo, pktopts, flags, 1534 cred); 1535 if (error) 1536 return error; 1537 break; 1538 default: 1539 return ENOPROTOOPT; 1540 } 1541 } 1542 return 0; 1543 } 1544 1545 /* 1546 * Set up IP options in pcb for insertion in output packets. 1547 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1548 * with destination address if source routed. 1549 */ 1550 static int 1551 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1552 { 1553 struct mbuf *m; 1554 const u_char *cp; 1555 u_char *dp; 1556 int cnt; 1557 1558 KASSERT(inp_locked(inp)); 1559 1560 /* Turn off any old options. */ 1561 if (inp->inp_options) { 1562 m_free(inp->inp_options); 1563 } 1564 inp->inp_options = NULL; 1565 if ((cnt = sopt->sopt_size) == 0) { 1566 /* Only turning off any previous options. */ 1567 return 0; 1568 } 1569 cp = sopt->sopt_data; 1570 1571 if (cnt % 4) { 1572 /* Must be 4-byte aligned, because there's no padding. */ 1573 return EINVAL; 1574 } 1575 1576 m = m_get(M_DONTWAIT, MT_SOOPTS); 1577 if (m == NULL) 1578 return ENOBUFS; 1579 1580 dp = mtod(m, u_char *); 1581 memset(dp, 0, sizeof(struct in_addr)); 1582 dp += sizeof(struct in_addr); 1583 m->m_len = sizeof(struct in_addr); 1584 1585 /* 1586 * IP option list according to RFC791. Each option is of the form 1587 * 1588 * [optval] [olen] [(olen - 2) data bytes] 1589 * 1590 * We validate the list and copy options to an mbuf for prepending 1591 * to data packets. The IP first-hop destination address will be 1592 * stored before actual options and is zero if unset. 1593 */ 1594 while (cnt > 0) { 1595 uint8_t optval, olen, offset; 1596 1597 optval = cp[IPOPT_OPTVAL]; 1598 1599 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1600 olen = 1; 1601 } else { 1602 if (cnt < IPOPT_OLEN + 1) 1603 goto bad; 1604 1605 olen = cp[IPOPT_OLEN]; 1606 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1607 goto bad; 1608 } 1609 1610 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1611 /* 1612 * user process specifies route as: 1613 * ->A->B->C->D 1614 * D must be our final destination (but we can't 1615 * check that since we may not have connected yet). 1616 * A is first hop destination, which doesn't appear in 1617 * actual IP option, but is stored before the options. 1618 */ 1619 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1620 goto bad; 1621 1622 offset = cp[IPOPT_OFFSET]; 1623 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1624 sizeof(struct in_addr)); 1625 1626 cp += sizeof(struct in_addr); 1627 cnt -= sizeof(struct in_addr); 1628 olen -= sizeof(struct in_addr); 1629 1630 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1631 goto bad; 1632 1633 memcpy(dp, cp, olen); 1634 dp[IPOPT_OPTVAL] = optval; 1635 dp[IPOPT_OLEN] = olen; 1636 dp[IPOPT_OFFSET] = offset; 1637 break; 1638 } else { 1639 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1640 goto bad; 1641 1642 memcpy(dp, cp, olen); 1643 break; 1644 } 1645 1646 dp += olen; 1647 m->m_len += olen; 1648 1649 if (optval == IPOPT_EOL) 1650 break; 1651 1652 cp += olen; 1653 cnt -= olen; 1654 } 1655 1656 inp->inp_options = m; 1657 return 0; 1658 1659 bad: 1660 (void)m_free(m); 1661 return EINVAL; 1662 } 1663 1664 /* 1665 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1666 * Must be called in a pserialize critical section. 1667 */ 1668 static struct ifnet * 1669 ip_multicast_if(struct in_addr *a, int *ifindexp) 1670 { 1671 int ifindex; 1672 struct ifnet *ifp = NULL; 1673 struct in_ifaddr *ia; 1674 1675 if (ifindexp) 1676 *ifindexp = 0; 1677 if (ntohl(a->s_addr) >> 24 == 0) { 1678 ifindex = ntohl(a->s_addr) & 0xffffff; 1679 ifp = if_byindex(ifindex); 1680 if (!ifp) 1681 return NULL; 1682 if (ifindexp) 1683 *ifindexp = ifindex; 1684 } else { 1685 IN_ADDRHASH_READER_FOREACH(ia, a->s_addr) { 1686 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1687 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1688 ifp = ia->ia_ifp; 1689 if (if_is_deactivated(ifp)) 1690 ifp = NULL; 1691 break; 1692 } 1693 } 1694 } 1695 return ifp; 1696 } 1697 1698 static int 1699 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1700 { 1701 u_int tval; 1702 u_char cval; 1703 int error; 1704 1705 if (sopt == NULL) 1706 return EINVAL; 1707 1708 switch (sopt->sopt_size) { 1709 case sizeof(u_char): 1710 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1711 tval = cval; 1712 break; 1713 1714 case sizeof(u_int): 1715 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1716 break; 1717 1718 default: 1719 error = EINVAL; 1720 } 1721 1722 if (error) 1723 return error; 1724 1725 if (tval > maxval) 1726 return EINVAL; 1727 1728 *val = tval; 1729 return 0; 1730 } 1731 1732 static int 1733 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1734 struct psref *psref, struct in_addr *ia, bool add) 1735 { 1736 int error; 1737 struct ip_mreq mreq; 1738 1739 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1740 if (error) 1741 return error; 1742 1743 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1744 return EINVAL; 1745 1746 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1747 1748 if (in_nullhost(mreq.imr_interface)) { 1749 union { 1750 struct sockaddr dst; 1751 struct sockaddr_in dst4; 1752 } u; 1753 struct route ro; 1754 1755 if (!add) { 1756 *ifp = NULL; 1757 return 0; 1758 } 1759 /* 1760 * If no interface address was provided, use the interface of 1761 * the route to the given multicast address. 1762 */ 1763 struct rtentry *rt; 1764 memset(&ro, 0, sizeof(ro)); 1765 1766 sockaddr_in_init(&u.dst4, ia, 0); 1767 error = rtcache_setdst(&ro, &u.dst); 1768 if (error != 0) 1769 return error; 1770 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1771 if (*ifp != NULL) { 1772 if (if_is_deactivated(*ifp)) 1773 *ifp = NULL; 1774 else 1775 if_acquire(*ifp, psref); 1776 } 1777 rtcache_unref(rt, &ro); 1778 rtcache_free(&ro); 1779 } else { 1780 int s = pserialize_read_enter(); 1781 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1782 if (!add && *ifp == NULL) { 1783 pserialize_read_exit(s); 1784 return EADDRNOTAVAIL; 1785 } 1786 if (*ifp != NULL) { 1787 if (if_is_deactivated(*ifp)) 1788 *ifp = NULL; 1789 else 1790 if_acquire(*ifp, psref); 1791 } 1792 pserialize_read_exit(s); 1793 } 1794 return 0; 1795 } 1796 1797 /* 1798 * Add a multicast group membership. 1799 * Group must be a valid IP multicast address. 1800 */ 1801 static int 1802 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1803 { 1804 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1805 struct in_addr ia; 1806 int i, error, bound; 1807 struct psref psref; 1808 1809 /* imo is protected by solock or referenced only by the caller */ 1810 1811 bound = curlwp_bind(); 1812 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1813 error = ip_get_membership(sopt, &ifp, &psref, &ia, true); 1814 else { 1815 #ifdef INET6 1816 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); 1817 #else 1818 error = EINVAL; 1819 #endif 1820 } 1821 1822 if (error) 1823 goto out; 1824 1825 /* 1826 * See if we found an interface, and confirm that it 1827 * supports multicast. 1828 */ 1829 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1830 error = EADDRNOTAVAIL; 1831 goto out; 1832 } 1833 1834 /* 1835 * See if the membership already exists or if all the 1836 * membership slots are full. 1837 */ 1838 for (i = 0; i < imo->imo_num_memberships; ++i) { 1839 if (imo->imo_membership[i]->inm_ifp == ifp && 1840 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1841 break; 1842 } 1843 if (i < imo->imo_num_memberships) { 1844 error = EADDRINUSE; 1845 goto out; 1846 } 1847 1848 if (i == IP_MAX_MEMBERSHIPS) { 1849 error = ETOOMANYREFS; 1850 goto out; 1851 } 1852 1853 /* 1854 * Everything looks good; add a new record to the multicast 1855 * address list for the given interface. 1856 */ 1857 imo->imo_membership[i] = in_addmulti(&ia, ifp); 1858 if (imo->imo_membership[i] == NULL) { 1859 error = ENOBUFS; 1860 goto out; 1861 } 1862 1863 ++imo->imo_num_memberships; 1864 error = 0; 1865 out: 1866 if_put(ifp, &psref); 1867 curlwp_bindx(bound); 1868 return error; 1869 } 1870 1871 /* 1872 * Drop a multicast group membership. 1873 * Group must be a valid IP multicast address. 1874 */ 1875 static int 1876 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1877 { 1878 struct in_addr ia = { .s_addr = 0 }; // XXX: gcc [ppc] 1879 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1880 int i, error, bound; 1881 struct psref psref; 1882 1883 /* imo is protected by solock or referenced only by the caller */ 1884 1885 bound = curlwp_bind(); 1886 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1887 error = ip_get_membership(sopt, &ifp, &psref, &ia, false); 1888 else { 1889 #ifdef INET6 1890 error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia)); 1891 #else 1892 error = EINVAL; 1893 #endif 1894 } 1895 1896 if (error) 1897 goto out; 1898 1899 /* 1900 * Find the membership in the membership array. 1901 */ 1902 for (i = 0; i < imo->imo_num_memberships; ++i) { 1903 if ((ifp == NULL || 1904 imo->imo_membership[i]->inm_ifp == ifp) && 1905 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1906 break; 1907 } 1908 if (i == imo->imo_num_memberships) { 1909 error = EADDRNOTAVAIL; 1910 goto out; 1911 } 1912 1913 /* 1914 * Give up the multicast address record to which the 1915 * membership points. 1916 */ 1917 in_delmulti(imo->imo_membership[i]); 1918 1919 /* 1920 * Remove the gap in the membership array. 1921 */ 1922 for (++i; i < imo->imo_num_memberships; ++i) 1923 imo->imo_membership[i-1] = imo->imo_membership[i]; 1924 --imo->imo_num_memberships; 1925 error = 0; 1926 out: 1927 if_put(ifp, &psref); 1928 curlwp_bindx(bound); 1929 return error; 1930 } 1931 1932 /* 1933 * Set the IP multicast options in response to user setsockopt(). 1934 */ 1935 int 1936 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1937 { 1938 struct ip_moptions *imo = *pimo; 1939 struct in_addr addr; 1940 struct ifnet *ifp; 1941 int ifindex, error = 0; 1942 1943 /* The passed imo isn't NULL, it should be protected by solock */ 1944 1945 if (!imo) { 1946 /* 1947 * No multicast option buffer attached to the pcb; 1948 * allocate one and initialize to default values. 1949 */ 1950 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1951 if (imo == NULL) 1952 return ENOBUFS; 1953 1954 imo->imo_multicast_if_index = 0; 1955 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1956 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1957 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1958 imo->imo_num_memberships = 0; 1959 *pimo = imo; 1960 } 1961 1962 switch (sopt->sopt_name) { 1963 case IP_MULTICAST_IF: { 1964 int s; 1965 /* 1966 * Select the interface for outgoing multicast packets. 1967 */ 1968 error = sockopt_get(sopt, &addr, sizeof(addr)); 1969 if (error) 1970 break; 1971 1972 /* 1973 * INADDR_ANY is used to remove a previous selection. 1974 * When no interface is selected, a default one is 1975 * chosen every time a multicast packet is sent. 1976 */ 1977 if (in_nullhost(addr)) { 1978 imo->imo_multicast_if_index = 0; 1979 break; 1980 } 1981 /* 1982 * The selected interface is identified by its local 1983 * IP address. Find the interface and confirm that 1984 * it supports multicasting. 1985 */ 1986 s = pserialize_read_enter(); 1987 ifp = ip_multicast_if(&addr, &ifindex); 1988 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1989 pserialize_read_exit(s); 1990 error = EADDRNOTAVAIL; 1991 break; 1992 } 1993 imo->imo_multicast_if_index = ifp->if_index; 1994 pserialize_read_exit(s); 1995 if (ifindex) 1996 imo->imo_multicast_addr = addr; 1997 else 1998 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1999 break; 2000 } 2001 2002 case IP_MULTICAST_TTL: 2003 /* 2004 * Set the IP time-to-live for outgoing multicast packets. 2005 */ 2006 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 2007 break; 2008 2009 case IP_MULTICAST_LOOP: 2010 /* 2011 * Set the loopback flag for outgoing multicast packets. 2012 * Must be zero or one. 2013 */ 2014 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 2015 break; 2016 2017 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 2018 error = ip_add_membership(imo, sopt); 2019 break; 2020 2021 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 2022 error = ip_drop_membership(imo, sopt); 2023 break; 2024 2025 default: 2026 error = EOPNOTSUPP; 2027 break; 2028 } 2029 2030 /* 2031 * If all options have default values, no need to keep the mbuf. 2032 */ 2033 if (imo->imo_multicast_if_index == 0 && 2034 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 2035 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 2036 imo->imo_num_memberships == 0) { 2037 kmem_intr_free(imo, sizeof(*imo)); 2038 *pimo = NULL; 2039 } 2040 2041 return error; 2042 } 2043 2044 /* 2045 * Return the IP multicast options in response to user getsockopt(). 2046 */ 2047 int 2048 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 2049 { 2050 struct in_addr addr; 2051 uint8_t optval; 2052 int error = 0; 2053 2054 /* imo is protected by solock or referenced only by the caller */ 2055 2056 switch (sopt->sopt_name) { 2057 case IP_MULTICAST_IF: 2058 if (imo == NULL || imo->imo_multicast_if_index == 0) 2059 addr = zeroin_addr; 2060 else if (imo->imo_multicast_addr.s_addr) { 2061 /* return the value user has set */ 2062 addr = imo->imo_multicast_addr; 2063 } else { 2064 struct ifnet *ifp; 2065 struct in_ifaddr *ia = NULL; 2066 int s = pserialize_read_enter(); 2067 2068 ifp = if_byindex(imo->imo_multicast_if_index); 2069 if (ifp != NULL) { 2070 ia = in_get_ia_from_ifp(ifp); 2071 } 2072 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 2073 pserialize_read_exit(s); 2074 } 2075 error = sockopt_set(sopt, &addr, sizeof(addr)); 2076 break; 2077 2078 case IP_MULTICAST_TTL: 2079 optval = imo ? imo->imo_multicast_ttl 2080 : IP_DEFAULT_MULTICAST_TTL; 2081 2082 error = sockopt_set(sopt, &optval, sizeof(optval)); 2083 break; 2084 2085 case IP_MULTICAST_LOOP: 2086 optval = imo ? imo->imo_multicast_loop 2087 : IP_DEFAULT_MULTICAST_LOOP; 2088 2089 error = sockopt_set(sopt, &optval, sizeof(optval)); 2090 break; 2091 2092 default: 2093 error = EOPNOTSUPP; 2094 } 2095 2096 return error; 2097 } 2098 2099 /* 2100 * Discard the IP multicast options. 2101 */ 2102 void 2103 ip_freemoptions(struct ip_moptions *imo) 2104 { 2105 int i; 2106 2107 /* The owner of imo (inp) should be protected by solock */ 2108 2109 if (imo != NULL) { 2110 for (i = 0; i < imo->imo_num_memberships; ++i) { 2111 struct in_multi *inm = imo->imo_membership[i]; 2112 in_delmulti(inm); 2113 /* ifp should not leave thanks to solock */ 2114 } 2115 2116 kmem_intr_free(imo, sizeof(*imo)); 2117 } 2118 } 2119 2120 /* 2121 * Routine called from ip_output() to loop back a copy of an IP multicast 2122 * packet to the input queue of a specified interface. Note that this 2123 * calls the output routine of the loopback "driver", but with an interface 2124 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 2125 */ 2126 static void 2127 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 2128 { 2129 struct ip *ip; 2130 struct mbuf *copym; 2131 2132 copym = m_copypacket(m, M_DONTWAIT); 2133 if (copym != NULL && 2134 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 2135 copym = m_pullup(copym, sizeof(struct ip)); 2136 if (copym == NULL) 2137 return; 2138 /* 2139 * We don't bother to fragment if the IP length is greater 2140 * than the interface's MTU. Can this possibly matter? 2141 */ 2142 ip = mtod(copym, struct ip *); 2143 2144 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 2145 in_undefer_cksum_tcpudp(copym); 2146 copym->m_pkthdr.csum_flags &= 2147 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 2148 } 2149 2150 ip->ip_sum = 0; 2151 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 2152 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 2153 (void)looutput(ifp, copym, sintocsa(dst), NULL); 2154 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 2155 } 2156 2157 /* 2158 * Ensure sending address is valid. 2159 * Returns 0 on success, -1 if an error should be sent back or 1 2160 * if the packet could be dropped without error (protocol dependent). 2161 */ 2162 static int 2163 ip_ifaddrvalid(const struct in_ifaddr *ia) 2164 { 2165 2166 if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY) 2167 return 0; 2168 2169 if (ia->ia4_flags & IN_IFF_DUPLICATED) 2170 return -1; 2171 else if (ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DETACHED)) 2172 return 1; 2173 2174 return 0; 2175 } 2176