1 /* $NetBSD: ip_output.c,v 1.224 2013/06/29 21:06:58 rmind 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 1.224 2013/06/29 21:06:58 rmind Exp $"); 95 96 #include "opt_inet.h" 97 #include "opt_ipsec.h" 98 #include "opt_mrouting.h" 99 100 #include <sys/param.h> 101 #include <sys/malloc.h> 102 #include <sys/kmem.h> 103 #include <sys/mbuf.h> 104 #include <sys/errno.h> 105 #include <sys/protosw.h> 106 #include <sys/socket.h> 107 #include <sys/socketvar.h> 108 #include <sys/kauth.h> 109 #ifdef IPSEC 110 #include <sys/domain.h> 111 #endif 112 #include <sys/systm.h> 113 #include <sys/proc.h> 114 115 #include <net/if.h> 116 #include <net/route.h> 117 #include <net/pfil.h> 118 119 #include <netinet/in.h> 120 #include <netinet/in_systm.h> 121 #include <netinet/ip.h> 122 #include <netinet/in_pcb.h> 123 #include <netinet/in_var.h> 124 #include <netinet/ip_var.h> 125 #include <netinet/ip_private.h> 126 #include <netinet/in_offload.h> 127 #include <netinet/portalgo.h> 128 #include <netinet/udp.h> 129 130 #ifdef MROUTING 131 #include <netinet/ip_mroute.h> 132 #endif 133 134 #include <netipsec/ipsec.h> 135 #include <netipsec/key.h> 136 137 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 138 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 139 static void ip_mloopback(struct ifnet *, struct mbuf *, 140 const struct sockaddr_in *); 141 142 extern pfil_head_t *inet_pfil_hook; /* XXX */ 143 144 int ip_do_loopback_cksum = 0; 145 146 /* 147 * IP output. The packet in mbuf chain m contains a skeletal IP 148 * header (with len, off, ttl, proto, tos, src, dst). 149 * The mbuf chain containing the packet will be freed. 150 * The mbuf opt, if present, will not be freed. 151 */ 152 int 153 ip_output(struct mbuf *m0, ...) 154 { 155 struct rtentry *rt; 156 struct ip *ip; 157 struct ifnet *ifp; 158 struct mbuf *m = m0; 159 int hlen = sizeof (struct ip); 160 int len, error = 0; 161 struct route iproute; 162 const struct sockaddr_in *dst; 163 struct in_ifaddr *ia; 164 struct ifaddr *xifa; 165 struct mbuf *opt; 166 struct route *ro; 167 int flags, sw_csum, *mtu_p; 168 u_long mtu; 169 struct ip_moptions *imo; 170 struct socket *so; 171 va_list ap; 172 struct secpolicy *sp = NULL; 173 bool natt_frag = false; 174 bool __unused done = false; 175 union { 176 struct sockaddr dst; 177 struct sockaddr_in dst4; 178 } u; 179 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 180 * to the nexthop 181 */ 182 183 len = 0; 184 va_start(ap, m0); 185 opt = va_arg(ap, struct mbuf *); 186 ro = va_arg(ap, struct route *); 187 flags = va_arg(ap, int); 188 imo = va_arg(ap, struct ip_moptions *); 189 so = va_arg(ap, struct socket *); 190 if (flags & IP_RETURNMTU) 191 mtu_p = va_arg(ap, int *); 192 else 193 mtu_p = NULL; 194 va_end(ap); 195 196 MCLAIM(m, &ip_tx_mowner); 197 198 #ifdef DIAGNOSTIC 199 if ((m->m_flags & M_PKTHDR) == 0) 200 panic("ip_output: no HDR"); 201 202 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) != 0) { 203 panic("ip_output: IPv6 checksum offload flags: %d", 204 m->m_pkthdr.csum_flags); 205 } 206 207 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) == 208 (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 209 panic("ip_output: conflicting checksum offload flags: %d", 210 m->m_pkthdr.csum_flags); 211 } 212 #endif 213 if (opt) { 214 m = ip_insertoptions(m, opt, &len); 215 if (len >= sizeof(struct ip)) 216 hlen = len; 217 } 218 ip = mtod(m, struct ip *); 219 /* 220 * Fill in IP header. 221 */ 222 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 223 ip->ip_v = IPVERSION; 224 ip->ip_off = htons(0); 225 /* ip->ip_id filled in after we find out source ia */ 226 ip->ip_hl = hlen >> 2; 227 IP_STATINC(IP_STAT_LOCALOUT); 228 } else { 229 hlen = ip->ip_hl << 2; 230 } 231 /* 232 * Route packet. 233 */ 234 memset(&iproute, 0, sizeof(iproute)); 235 if (ro == NULL) 236 ro = &iproute; 237 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 238 dst = satocsin(rtcache_getdst(ro)); 239 /* 240 * If there is a cached route, 241 * check that it is to the same destination 242 * and is still up. If not, free it and try again. 243 * The address family should also be checked in case of sharing the 244 * cache with IPv6. 245 */ 246 if (dst == NULL) 247 ; 248 else if (dst->sin_family != AF_INET || 249 !in_hosteq(dst->sin_addr, ip->ip_dst)) 250 rtcache_free(ro); 251 252 if ((rt = rtcache_validate(ro)) == NULL && 253 (rt = rtcache_update(ro, 1)) == NULL) { 254 dst = &u.dst4; 255 rtcache_setdst(ro, &u.dst); 256 } 257 /* 258 * If routing to interface only, 259 * short circuit routing lookup. 260 */ 261 if (flags & IP_ROUTETOIF) { 262 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 263 IP_STATINC(IP_STAT_NOROUTE); 264 error = ENETUNREACH; 265 goto bad; 266 } 267 ifp = ia->ia_ifp; 268 mtu = ifp->if_mtu; 269 ip->ip_ttl = 1; 270 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 271 ip->ip_dst.s_addr == INADDR_BROADCAST) && 272 imo != NULL && imo->imo_multicast_ifp != NULL) { 273 ifp = imo->imo_multicast_ifp; 274 mtu = ifp->if_mtu; 275 IFP_TO_IA(ifp, ia); 276 } else { 277 if (rt == NULL) 278 rt = rtcache_init(ro); 279 if (rt == NULL) { 280 IP_STATINC(IP_STAT_NOROUTE); 281 error = EHOSTUNREACH; 282 goto bad; 283 } 284 ia = ifatoia(rt->rt_ifa); 285 ifp = rt->rt_ifp; 286 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 287 mtu = ifp->if_mtu; 288 rt->rt_use++; 289 if (rt->rt_flags & RTF_GATEWAY) 290 dst = satosin(rt->rt_gateway); 291 } 292 if (IN_MULTICAST(ip->ip_dst.s_addr) || 293 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 294 struct in_multi *inm; 295 296 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 297 M_BCAST : M_MCAST; 298 /* 299 * See if the caller provided any multicast options 300 */ 301 if (imo != NULL) 302 ip->ip_ttl = imo->imo_multicast_ttl; 303 else 304 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 305 306 /* 307 * if we don't know the outgoing ifp yet, we can't generate 308 * output 309 */ 310 if (!ifp) { 311 IP_STATINC(IP_STAT_NOROUTE); 312 error = ENETUNREACH; 313 goto bad; 314 } 315 316 /* 317 * If the packet is multicast or broadcast, confirm that 318 * the outgoing interface can transmit it. 319 */ 320 if (((m->m_flags & M_MCAST) && 321 (ifp->if_flags & IFF_MULTICAST) == 0) || 322 ((m->m_flags & M_BCAST) && 323 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 324 IP_STATINC(IP_STAT_NOROUTE); 325 error = ENETUNREACH; 326 goto bad; 327 } 328 /* 329 * If source address not specified yet, use an address 330 * of outgoing interface. 331 */ 332 if (in_nullhost(ip->ip_src)) { 333 struct in_ifaddr *xia; 334 335 IFP_TO_IA(ifp, xia); 336 if (!xia) { 337 error = EADDRNOTAVAIL; 338 goto bad; 339 } 340 xifa = &xia->ia_ifa; 341 if (xifa->ifa_getifa != NULL) { 342 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 343 } 344 ip->ip_src = xia->ia_addr.sin_addr; 345 } 346 347 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 348 if (inm != NULL && 349 (imo == NULL || imo->imo_multicast_loop)) { 350 /* 351 * If we belong to the destination multicast group 352 * on the outgoing interface, and the caller did not 353 * forbid loopback, loop back a copy. 354 */ 355 ip_mloopback(ifp, m, &u.dst4); 356 } 357 #ifdef MROUTING 358 else { 359 /* 360 * If we are acting as a multicast router, perform 361 * multicast forwarding as if the packet had just 362 * arrived on the interface to which we are about 363 * to send. The multicast forwarding function 364 * recursively calls this function, using the 365 * IP_FORWARDING flag to prevent infinite recursion. 366 * 367 * Multicasts that are looped back by ip_mloopback(), 368 * above, will be forwarded by the ip_input() routine, 369 * if necessary. 370 */ 371 extern struct socket *ip_mrouter; 372 373 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 374 if (ip_mforward(m, ifp) != 0) { 375 m_freem(m); 376 goto done; 377 } 378 } 379 } 380 #endif 381 /* 382 * Multicasts with a time-to-live of zero may be looped- 383 * back, above, but must not be transmitted on a network. 384 * Also, multicasts addressed to the loopback interface 385 * are not sent -- the above call to ip_mloopback() will 386 * loop back a copy if this host actually belongs to the 387 * destination group on the loopback interface. 388 */ 389 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 390 m_freem(m); 391 goto done; 392 } 393 394 goto sendit; 395 } 396 /* 397 * If source address not specified yet, use address 398 * of outgoing interface. 399 */ 400 if (in_nullhost(ip->ip_src)) { 401 xifa = &ia->ia_ifa; 402 if (xifa->ifa_getifa != NULL) 403 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 404 ip->ip_src = ia->ia_addr.sin_addr; 405 } 406 407 /* 408 * packets with Class-D address as source are not valid per 409 * RFC 1112 410 */ 411 if (IN_MULTICAST(ip->ip_src.s_addr)) { 412 IP_STATINC(IP_STAT_ODROPPED); 413 error = EADDRNOTAVAIL; 414 goto bad; 415 } 416 417 /* 418 * Look for broadcast address and 419 * and verify user is allowed to send 420 * such a packet. 421 */ 422 if (in_broadcast(dst->sin_addr, ifp)) { 423 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 424 error = EADDRNOTAVAIL; 425 goto bad; 426 } 427 if ((flags & IP_ALLOWBROADCAST) == 0) { 428 error = EACCES; 429 goto bad; 430 } 431 /* don't allow broadcast messages to be fragmented */ 432 if (ntohs(ip->ip_len) > ifp->if_mtu) { 433 error = EMSGSIZE; 434 goto bad; 435 } 436 m->m_flags |= M_BCAST; 437 } else 438 m->m_flags &= ~M_BCAST; 439 440 sendit: 441 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 442 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 443 ip->ip_id = 0; 444 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 445 ip->ip_id = ip_newid(ia); 446 } else { 447 448 /* 449 * TSO capable interfaces (typically?) increment 450 * ip_id for each segment. 451 * "allocate" enough ids here to increase the chance 452 * for them to be unique. 453 * 454 * note that the following calculation is not 455 * needed to be precise. wasting some ip_id is fine. 456 */ 457 458 unsigned int segsz = m->m_pkthdr.segsz; 459 unsigned int datasz = ntohs(ip->ip_len) - hlen; 460 unsigned int num = howmany(datasz, segsz); 461 462 ip->ip_id = ip_newid_range(ia, num); 463 } 464 } 465 /* 466 * If we're doing Path MTU Discovery, we need to set DF unless 467 * the route's MTU is locked. 468 */ 469 if ((flags & IP_MTUDISC) != 0 && rt != NULL && 470 (rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 471 ip->ip_off |= htons(IP_DF); 472 473 #ifdef IPSEC 474 /* Perform IPsec processing, if any. */ 475 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, &done); 476 if (error || done) { 477 goto done; 478 } 479 #endif 480 481 /* 482 * Run through list of hooks for output packets. 483 */ 484 if ((error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) 485 goto done; 486 if (m == NULL) 487 goto done; 488 489 ip = mtod(m, struct ip *); 490 hlen = ip->ip_hl << 2; 491 492 m->m_pkthdr.csum_data |= hlen << 16; 493 494 #if IFA_STATS 495 /* 496 * search for the source address structure to 497 * maintain output statistics. 498 */ 499 INADDR_TO_IA(ip->ip_src, ia); 500 #endif 501 502 /* Maybe skip checksums on loopback interfaces. */ 503 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 504 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 505 } 506 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 507 /* 508 * If small enough for mtu of path, or if using TCP segmentation 509 * offload, can just send directly. 510 */ 511 if (ntohs(ip->ip_len) <= mtu || 512 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 513 #if IFA_STATS 514 if (ia) 515 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 516 #endif 517 /* 518 * Always initialize the sum to 0! Some HW assisted 519 * checksumming requires this. 520 */ 521 ip->ip_sum = 0; 522 523 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 524 /* 525 * Perform any checksums that the hardware can't do 526 * for us. 527 * 528 * XXX Does any hardware require the {th,uh}_sum 529 * XXX fields to be 0? 530 */ 531 if (sw_csum & M_CSUM_IPv4) { 532 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 533 ip->ip_sum = in_cksum(m, hlen); 534 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 535 } 536 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 537 if (IN_NEED_CHECKSUM(ifp, 538 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 539 in_delayed_cksum(m); 540 } 541 m->m_pkthdr.csum_flags &= 542 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 543 } 544 } 545 546 if (__predict_true( 547 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 548 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 549 KERNEL_LOCK(1, NULL); 550 error = 551 (*ifp->if_output)(ifp, m, 552 (m->m_flags & M_MCAST) ? 553 sintocsa(rdst) : sintocsa(dst), 554 rt); 555 KERNEL_UNLOCK_ONE(NULL); 556 } else { 557 error = 558 ip_tso_output(ifp, m, 559 (m->m_flags & M_MCAST) ? 560 sintocsa(rdst) : sintocsa(dst), 561 rt); 562 } 563 goto done; 564 } 565 566 /* 567 * We can't use HW checksumming if we're about to 568 * to fragment the packet. 569 * 570 * XXX Some hardware can do this. 571 */ 572 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 573 if (IN_NEED_CHECKSUM(ifp, 574 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 575 in_delayed_cksum(m); 576 } 577 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 578 } 579 580 /* 581 * Too large for interface; fragment if possible. 582 * Must be able to put at least 8 bytes per fragment. 583 */ 584 if (ntohs(ip->ip_off) & IP_DF) { 585 if (flags & IP_RETURNMTU) 586 *mtu_p = mtu; 587 error = EMSGSIZE; 588 IP_STATINC(IP_STAT_CANTFRAG); 589 goto bad; 590 } 591 592 error = ip_fragment(m, ifp, mtu); 593 if (error) { 594 m = NULL; 595 goto bad; 596 } 597 598 for (; m; m = m0) { 599 m0 = m->m_nextpkt; 600 m->m_nextpkt = 0; 601 if (error == 0) { 602 #if IFA_STATS 603 if (ia) 604 ia->ia_ifa.ifa_data.ifad_outbytes += 605 ntohs(ip->ip_len); 606 #endif 607 /* 608 * If we get there, the packet has not been handled by 609 * IPsec whereas it should have. Now that it has been 610 * fragmented, re-inject it in ip_output so that IPsec 611 * processing can occur. 612 */ 613 if (natt_frag) { 614 error = ip_output(m, opt, ro, 615 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 616 imo, so, mtu_p); 617 } else { 618 KASSERT((m->m_pkthdr.csum_flags & 619 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 620 KERNEL_LOCK(1, NULL); 621 error = (*ifp->if_output)(ifp, m, 622 (m->m_flags & M_MCAST) ? 623 sintocsa(rdst) : sintocsa(dst), 624 rt); 625 KERNEL_UNLOCK_ONE(NULL); 626 } 627 } else 628 m_freem(m); 629 } 630 631 if (error == 0) 632 IP_STATINC(IP_STAT_FRAGMENTED); 633 done: 634 rtcache_free(&iproute); 635 if (sp) { 636 #ifdef IPSEC 637 KEY_FREESP(&sp); 638 #endif 639 } 640 return error; 641 bad: 642 m_freem(m); 643 goto done; 644 } 645 646 int 647 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 648 { 649 struct ip *ip, *mhip; 650 struct mbuf *m0; 651 int len, hlen, off; 652 int mhlen, firstlen; 653 struct mbuf **mnext; 654 int sw_csum = m->m_pkthdr.csum_flags; 655 int fragments = 0; 656 int s; 657 int error = 0; 658 659 ip = mtod(m, struct ip *); 660 hlen = ip->ip_hl << 2; 661 if (ifp != NULL) 662 sw_csum &= ~ifp->if_csum_flags_tx; 663 664 len = (mtu - hlen) &~ 7; 665 if (len < 8) { 666 m_freem(m); 667 return (EMSGSIZE); 668 } 669 670 firstlen = len; 671 mnext = &m->m_nextpkt; 672 673 /* 674 * Loop through length of segment after first fragment, 675 * make new header and copy data of each part and link onto chain. 676 */ 677 m0 = m; 678 mhlen = sizeof (struct ip); 679 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 680 MGETHDR(m, M_DONTWAIT, MT_HEADER); 681 if (m == 0) { 682 error = ENOBUFS; 683 IP_STATINC(IP_STAT_ODROPPED); 684 goto sendorfree; 685 } 686 MCLAIM(m, m0->m_owner); 687 *mnext = m; 688 mnext = &m->m_nextpkt; 689 m->m_data += max_linkhdr; 690 mhip = mtod(m, struct ip *); 691 *mhip = *ip; 692 /* we must inherit MCAST and BCAST flags */ 693 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 694 if (hlen > sizeof (struct ip)) { 695 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 696 mhip->ip_hl = mhlen >> 2; 697 } 698 m->m_len = mhlen; 699 mhip->ip_off = ((off - hlen) >> 3) + 700 (ntohs(ip->ip_off) & ~IP_MF); 701 if (ip->ip_off & htons(IP_MF)) 702 mhip->ip_off |= IP_MF; 703 if (off + len >= ntohs(ip->ip_len)) 704 len = ntohs(ip->ip_len) - off; 705 else 706 mhip->ip_off |= IP_MF; 707 HTONS(mhip->ip_off); 708 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 709 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 710 if (m->m_next == 0) { 711 error = ENOBUFS; /* ??? */ 712 IP_STATINC(IP_STAT_ODROPPED); 713 goto sendorfree; 714 } 715 m->m_pkthdr.len = mhlen + len; 716 m->m_pkthdr.rcvif = NULL; 717 mhip->ip_sum = 0; 718 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 719 if (sw_csum & M_CSUM_IPv4) { 720 mhip->ip_sum = in_cksum(m, mhlen); 721 } else { 722 /* 723 * checksum is hw-offloaded or not necessary. 724 */ 725 m->m_pkthdr.csum_flags |= 726 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 727 m->m_pkthdr.csum_data |= mhlen << 16; 728 KASSERT(!(ifp != NULL && 729 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 730 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 731 } 732 IP_STATINC(IP_STAT_OFRAGMENTS); 733 fragments++; 734 } 735 /* 736 * Update first fragment by trimming what's been copied out 737 * and updating header, then send each fragment (in order). 738 */ 739 m = m0; 740 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 741 m->m_pkthdr.len = hlen + firstlen; 742 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 743 ip->ip_off |= htons(IP_MF); 744 ip->ip_sum = 0; 745 if (sw_csum & M_CSUM_IPv4) { 746 ip->ip_sum = in_cksum(m, hlen); 747 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 748 } else { 749 /* 750 * checksum is hw-offloaded or not necessary. 751 */ 752 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 753 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 754 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 755 sizeof(struct ip)); 756 } 757 sendorfree: 758 /* 759 * If there is no room for all the fragments, don't queue 760 * any of them. 761 */ 762 if (ifp != NULL) { 763 s = splnet(); 764 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 765 error == 0) { 766 error = ENOBUFS; 767 IP_STATINC(IP_STAT_ODROPPED); 768 IFQ_INC_DROPS(&ifp->if_snd); 769 } 770 splx(s); 771 } 772 if (error) { 773 for (m = m0; m; m = m0) { 774 m0 = m->m_nextpkt; 775 m->m_nextpkt = NULL; 776 m_freem(m); 777 } 778 } 779 return (error); 780 } 781 782 /* 783 * Process a delayed payload checksum calculation. 784 */ 785 void 786 in_delayed_cksum(struct mbuf *m) 787 { 788 struct ip *ip; 789 u_int16_t csum, offset; 790 791 ip = mtod(m, struct ip *); 792 offset = ip->ip_hl << 2; 793 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 794 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 795 csum = 0xffff; 796 797 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 798 799 if ((offset + sizeof(u_int16_t)) > m->m_len) { 800 /* This happen when ip options were inserted 801 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 802 m->m_len, offset, ip->ip_p); 803 */ 804 m_copyback(m, offset, sizeof(csum), (void *) &csum); 805 } else 806 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 807 } 808 809 /* 810 * Determine the maximum length of the options to be inserted; 811 * we would far rather allocate too much space rather than too little. 812 */ 813 814 u_int 815 ip_optlen(struct inpcb *inp) 816 { 817 struct mbuf *m = inp->inp_options; 818 819 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 820 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 821 else 822 return 0; 823 } 824 825 826 /* 827 * Insert IP options into preformed packet. 828 * Adjust IP destination as required for IP source routing, 829 * as indicated by a non-zero in_addr at the start of the options. 830 */ 831 static struct mbuf * 832 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 833 { 834 struct ipoption *p = mtod(opt, struct ipoption *); 835 struct mbuf *n; 836 struct ip *ip = mtod(m, struct ip *); 837 unsigned optlen; 838 839 optlen = opt->m_len - sizeof(p->ipopt_dst); 840 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 841 return (m); /* XXX should fail */ 842 if (!in_nullhost(p->ipopt_dst)) 843 ip->ip_dst = p->ipopt_dst; 844 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 845 MGETHDR(n, M_DONTWAIT, MT_HEADER); 846 if (n == 0) 847 return (m); 848 MCLAIM(n, m->m_owner); 849 M_MOVE_PKTHDR(n, m); 850 m->m_len -= sizeof(struct ip); 851 m->m_data += sizeof(struct ip); 852 n->m_next = m; 853 m = n; 854 m->m_len = optlen + sizeof(struct ip); 855 m->m_data += max_linkhdr; 856 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 857 } else { 858 m->m_data -= optlen; 859 m->m_len += optlen; 860 memmove(mtod(m, void *), ip, sizeof(struct ip)); 861 } 862 m->m_pkthdr.len += optlen; 863 ip = mtod(m, struct ip *); 864 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 865 *phlen = sizeof(struct ip) + optlen; 866 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 867 return (m); 868 } 869 870 /* 871 * Copy options from ip to jp, 872 * omitting those not copied during fragmentation. 873 */ 874 int 875 ip_optcopy(struct ip *ip, struct ip *jp) 876 { 877 u_char *cp, *dp; 878 int opt, optlen, cnt; 879 880 cp = (u_char *)(ip + 1); 881 dp = (u_char *)(jp + 1); 882 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 883 for (; cnt > 0; cnt -= optlen, cp += optlen) { 884 opt = cp[0]; 885 if (opt == IPOPT_EOL) 886 break; 887 if (opt == IPOPT_NOP) { 888 /* Preserve for IP mcast tunnel's LSRR alignment. */ 889 *dp++ = IPOPT_NOP; 890 optlen = 1; 891 continue; 892 } 893 #ifdef DIAGNOSTIC 894 if (cnt < IPOPT_OLEN + sizeof(*cp)) 895 panic("malformed IPv4 option passed to ip_optcopy"); 896 #endif 897 optlen = cp[IPOPT_OLEN]; 898 #ifdef DIAGNOSTIC 899 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 900 panic("malformed IPv4 option passed to ip_optcopy"); 901 #endif 902 /* bogus lengths should have been caught by ip_dooptions */ 903 if (optlen > cnt) 904 optlen = cnt; 905 if (IPOPT_COPIED(opt)) { 906 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 907 dp += optlen; 908 } 909 } 910 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 911 *dp++ = IPOPT_EOL; 912 return (optlen); 913 } 914 915 /* 916 * IP socket option processing. 917 */ 918 int 919 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 920 { 921 struct inpcb *inp = sotoinpcb(so); 922 int optval = 0; 923 int error = 0; 924 #if defined(IPSEC) 925 struct lwp *l = curlwp; /*XXX*/ 926 #endif 927 928 if (sopt->sopt_level != IPPROTO_IP) { 929 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 930 return 0; 931 return ENOPROTOOPT; 932 } 933 934 switch (op) { 935 case PRCO_SETOPT: 936 switch (sopt->sopt_name) { 937 case IP_OPTIONS: 938 #ifdef notyet 939 case IP_RETOPTS: 940 #endif 941 error = ip_pcbopts(&inp->inp_options, sopt); 942 break; 943 944 case IP_TOS: 945 case IP_TTL: 946 case IP_MINTTL: 947 case IP_PKTINFO: 948 case IP_RECVOPTS: 949 case IP_RECVRETOPTS: 950 case IP_RECVDSTADDR: 951 case IP_RECVIF: 952 case IP_RECVPKTINFO: 953 case IP_RECVTTL: 954 error = sockopt_getint(sopt, &optval); 955 if (error) 956 break; 957 958 switch (sopt->sopt_name) { 959 case IP_TOS: 960 inp->inp_ip.ip_tos = optval; 961 break; 962 963 case IP_TTL: 964 inp->inp_ip.ip_ttl = optval; 965 break; 966 967 case IP_MINTTL: 968 if (optval > 0 && optval <= MAXTTL) 969 inp->inp_ip_minttl = optval; 970 else 971 error = EINVAL; 972 break; 973 #define OPTSET(bit) \ 974 if (optval) \ 975 inp->inp_flags |= bit; \ 976 else \ 977 inp->inp_flags &= ~bit; 978 979 case IP_PKTINFO: 980 OPTSET(INP_PKTINFO); 981 break; 982 983 case IP_RECVOPTS: 984 OPTSET(INP_RECVOPTS); 985 break; 986 987 case IP_RECVPKTINFO: 988 OPTSET(INP_RECVPKTINFO); 989 break; 990 991 case IP_RECVRETOPTS: 992 OPTSET(INP_RECVRETOPTS); 993 break; 994 995 case IP_RECVDSTADDR: 996 OPTSET(INP_RECVDSTADDR); 997 break; 998 999 case IP_RECVIF: 1000 OPTSET(INP_RECVIF); 1001 break; 1002 1003 case IP_RECVTTL: 1004 OPTSET(INP_RECVTTL); 1005 break; 1006 } 1007 break; 1008 #undef OPTSET 1009 1010 case IP_MULTICAST_IF: 1011 case IP_MULTICAST_TTL: 1012 case IP_MULTICAST_LOOP: 1013 case IP_ADD_MEMBERSHIP: 1014 case IP_DROP_MEMBERSHIP: 1015 error = ip_setmoptions(&inp->inp_moptions, sopt); 1016 break; 1017 1018 case IP_PORTRANGE: 1019 error = sockopt_getint(sopt, &optval); 1020 if (error) 1021 break; 1022 1023 /* INP_LOCK(inp); */ 1024 switch (optval) { 1025 case IP_PORTRANGE_DEFAULT: 1026 case IP_PORTRANGE_HIGH: 1027 inp->inp_flags &= ~(INP_LOWPORT); 1028 break; 1029 1030 case IP_PORTRANGE_LOW: 1031 inp->inp_flags |= INP_LOWPORT; 1032 break; 1033 1034 default: 1035 error = EINVAL; 1036 break; 1037 } 1038 /* INP_UNLOCK(inp); */ 1039 break; 1040 1041 case IP_PORTALGO: 1042 error = sockopt_getint(sopt, &optval); 1043 if (error) 1044 break; 1045 1046 error = portalgo_algo_index_select( 1047 (struct inpcb_hdr *)inp, optval); 1048 break; 1049 1050 #if defined(IPSEC) 1051 case IP_IPSEC_POLICY: 1052 error = ipsec4_set_policy(inp, sopt->sopt_name, 1053 sopt->sopt_data, sopt->sopt_size, l->l_cred); 1054 break; 1055 #endif /*IPSEC*/ 1056 1057 default: 1058 error = ENOPROTOOPT; 1059 break; 1060 } 1061 break; 1062 1063 case PRCO_GETOPT: 1064 switch (sopt->sopt_name) { 1065 case IP_OPTIONS: 1066 case IP_RETOPTS: 1067 if (inp->inp_options) { 1068 struct mbuf *m; 1069 1070 m = m_copym(inp->inp_options, 0, M_COPYALL, 1071 M_DONTWAIT); 1072 if (m == NULL) { 1073 error = ENOBUFS; 1074 break; 1075 } 1076 1077 error = sockopt_setmbuf(sopt, m); 1078 } 1079 break; 1080 1081 case IP_PKTINFO: 1082 case IP_TOS: 1083 case IP_TTL: 1084 case IP_MINTTL: 1085 case IP_RECVOPTS: 1086 case IP_RECVRETOPTS: 1087 case IP_RECVDSTADDR: 1088 case IP_RECVIF: 1089 case IP_RECVPKTINFO: 1090 case IP_RECVTTL: 1091 case IP_ERRORMTU: 1092 switch (sopt->sopt_name) { 1093 case IP_TOS: 1094 optval = inp->inp_ip.ip_tos; 1095 break; 1096 1097 case IP_TTL: 1098 optval = inp->inp_ip.ip_ttl; 1099 break; 1100 1101 case IP_MINTTL: 1102 optval = inp->inp_ip_minttl; 1103 break; 1104 1105 case IP_ERRORMTU: 1106 optval = inp->inp_errormtu; 1107 break; 1108 1109 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1110 1111 case IP_PKTINFO: 1112 optval = OPTBIT(INP_PKTINFO); 1113 break; 1114 1115 case IP_RECVOPTS: 1116 optval = OPTBIT(INP_RECVOPTS); 1117 break; 1118 1119 case IP_RECVPKTINFO: 1120 optval = OPTBIT(INP_RECVPKTINFO); 1121 break; 1122 1123 case IP_RECVRETOPTS: 1124 optval = OPTBIT(INP_RECVRETOPTS); 1125 break; 1126 1127 case IP_RECVDSTADDR: 1128 optval = OPTBIT(INP_RECVDSTADDR); 1129 break; 1130 1131 case IP_RECVIF: 1132 optval = OPTBIT(INP_RECVIF); 1133 break; 1134 1135 case IP_RECVTTL: 1136 optval = OPTBIT(INP_RECVTTL); 1137 break; 1138 } 1139 error = sockopt_setint(sopt, optval); 1140 break; 1141 1142 #if 0 /* defined(IPSEC) */ 1143 case IP_IPSEC_POLICY: 1144 { 1145 struct mbuf *m = NULL; 1146 1147 /* XXX this will return EINVAL as sopt is empty */ 1148 error = ipsec4_get_policy(inp, sopt->sopt_data, 1149 sopt->sopt_size, &m); 1150 if (error == 0) 1151 error = sockopt_setmbuf(sopt, m); 1152 break; 1153 } 1154 #endif /*IPSEC*/ 1155 1156 case IP_MULTICAST_IF: 1157 case IP_MULTICAST_TTL: 1158 case IP_MULTICAST_LOOP: 1159 case IP_ADD_MEMBERSHIP: 1160 case IP_DROP_MEMBERSHIP: 1161 error = ip_getmoptions(inp->inp_moptions, sopt); 1162 break; 1163 1164 case IP_PORTRANGE: 1165 if (inp->inp_flags & INP_LOWPORT) 1166 optval = IP_PORTRANGE_LOW; 1167 else 1168 optval = IP_PORTRANGE_DEFAULT; 1169 1170 error = sockopt_setint(sopt, optval); 1171 1172 break; 1173 1174 case IP_PORTALGO: 1175 optval = ((struct inpcb_hdr *)inp)->inph_portalgo; 1176 error = sockopt_setint(sopt, optval); 1177 break; 1178 1179 default: 1180 error = ENOPROTOOPT; 1181 break; 1182 } 1183 break; 1184 } 1185 return (error); 1186 } 1187 1188 /* 1189 * Set up IP options in pcb for insertion in output packets. 1190 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1191 * with destination address if source routed. 1192 */ 1193 int 1194 ip_pcbopts(struct mbuf **pcbopt, const struct sockopt *sopt) 1195 { 1196 struct mbuf *m; 1197 const u_char *cp; 1198 u_char *dp; 1199 int cnt; 1200 uint8_t optval, olen, offset; 1201 1202 /* turn off any old options */ 1203 if (*pcbopt) 1204 (void)m_free(*pcbopt); 1205 *pcbopt = NULL; 1206 1207 cp = sopt->sopt_data; 1208 cnt = sopt->sopt_size; 1209 1210 if (cnt == 0) 1211 return (0); /* Only turning off any previous options */ 1212 1213 #ifndef __vax__ 1214 if (cnt % sizeof(int32_t)) 1215 return (EINVAL); 1216 #endif 1217 1218 m = m_get(M_DONTWAIT, MT_SOOPTS); 1219 if (m == NULL) 1220 return (ENOBUFS); 1221 1222 dp = mtod(m, u_char *); 1223 memset(dp, 0, sizeof(struct in_addr)); 1224 dp += sizeof(struct in_addr); 1225 m->m_len = sizeof(struct in_addr); 1226 1227 /* 1228 * IP option list according to RFC791. Each option is of the form 1229 * 1230 * [optval] [olen] [(olen - 2) data bytes] 1231 * 1232 * we validate the list and copy options to an mbuf for prepending 1233 * to data packets. The IP first-hop destination address will be 1234 * stored before actual options and is zero if unset. 1235 */ 1236 while (cnt > 0) { 1237 optval = cp[IPOPT_OPTVAL]; 1238 1239 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1240 olen = 1; 1241 } else { 1242 if (cnt < IPOPT_OLEN + 1) 1243 goto bad; 1244 1245 olen = cp[IPOPT_OLEN]; 1246 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1247 goto bad; 1248 } 1249 1250 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1251 /* 1252 * user process specifies route as: 1253 * ->A->B->C->D 1254 * D must be our final destination (but we can't 1255 * check that since we may not have connected yet). 1256 * A is first hop destination, which doesn't appear in 1257 * actual IP option, but is stored before the options. 1258 */ 1259 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1260 goto bad; 1261 1262 offset = cp[IPOPT_OFFSET]; 1263 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1264 sizeof(struct in_addr)); 1265 1266 cp += sizeof(struct in_addr); 1267 cnt -= sizeof(struct in_addr); 1268 olen -= sizeof(struct in_addr); 1269 1270 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1271 goto bad; 1272 1273 memcpy(dp, cp, olen); 1274 dp[IPOPT_OPTVAL] = optval; 1275 dp[IPOPT_OLEN] = olen; 1276 dp[IPOPT_OFFSET] = offset; 1277 break; 1278 } else { 1279 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1280 goto bad; 1281 1282 memcpy(dp, cp, olen); 1283 break; 1284 } 1285 1286 dp += olen; 1287 m->m_len += olen; 1288 1289 if (optval == IPOPT_EOL) 1290 break; 1291 1292 cp += olen; 1293 cnt -= olen; 1294 } 1295 1296 *pcbopt = m; 1297 return (0); 1298 1299 bad: 1300 (void)m_free(m); 1301 return (EINVAL); 1302 } 1303 1304 /* 1305 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1306 */ 1307 static struct ifnet * 1308 ip_multicast_if(struct in_addr *a, int *ifindexp) 1309 { 1310 int ifindex; 1311 struct ifnet *ifp = NULL; 1312 struct in_ifaddr *ia; 1313 1314 if (ifindexp) 1315 *ifindexp = 0; 1316 if (ntohl(a->s_addr) >> 24 == 0) { 1317 ifindex = ntohl(a->s_addr) & 0xffffff; 1318 if (ifindex < 0 || if_indexlim <= ifindex) 1319 return NULL; 1320 ifp = ifindex2ifnet[ifindex]; 1321 if (!ifp) 1322 return NULL; 1323 if (ifindexp) 1324 *ifindexp = ifindex; 1325 } else { 1326 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1327 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1328 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1329 ifp = ia->ia_ifp; 1330 break; 1331 } 1332 } 1333 } 1334 return ifp; 1335 } 1336 1337 static int 1338 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1339 { 1340 u_int tval; 1341 u_char cval; 1342 int error; 1343 1344 if (sopt == NULL) 1345 return EINVAL; 1346 1347 switch (sopt->sopt_size) { 1348 case sizeof(u_char): 1349 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1350 tval = cval; 1351 break; 1352 1353 case sizeof(u_int): 1354 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1355 break; 1356 1357 default: 1358 error = EINVAL; 1359 } 1360 1361 if (error) 1362 return error; 1363 1364 if (tval > maxval) 1365 return EINVAL; 1366 1367 *val = tval; 1368 return 0; 1369 } 1370 1371 /* 1372 * Set the IP multicast options in response to user setsockopt(). 1373 */ 1374 int 1375 ip_setmoptions(struct ip_moptions **imop, const struct sockopt *sopt) 1376 { 1377 struct in_addr addr; 1378 struct ip_mreq lmreq, *mreq; 1379 struct ifnet *ifp; 1380 struct ip_moptions *imo = *imop; 1381 int i, ifindex, error = 0; 1382 1383 if (imo == NULL) { 1384 /* 1385 * No multicast option buffer attached to the pcb; 1386 * allocate one and initialize to default values. 1387 */ 1388 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1389 if (imo == NULL) 1390 return ENOBUFS; 1391 1392 imo->imo_multicast_ifp = NULL; 1393 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1394 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1395 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1396 imo->imo_num_memberships = 0; 1397 *imop = imo; 1398 } 1399 1400 switch (sopt->sopt_name) { 1401 case IP_MULTICAST_IF: 1402 /* 1403 * Select the interface for outgoing multicast packets. 1404 */ 1405 error = sockopt_get(sopt, &addr, sizeof(addr)); 1406 if (error) 1407 break; 1408 1409 /* 1410 * INADDR_ANY is used to remove a previous selection. 1411 * When no interface is selected, a default one is 1412 * chosen every time a multicast packet is sent. 1413 */ 1414 if (in_nullhost(addr)) { 1415 imo->imo_multicast_ifp = NULL; 1416 break; 1417 } 1418 /* 1419 * The selected interface is identified by its local 1420 * IP address. Find the interface and confirm that 1421 * it supports multicasting. 1422 */ 1423 ifp = ip_multicast_if(&addr, &ifindex); 1424 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1425 error = EADDRNOTAVAIL; 1426 break; 1427 } 1428 imo->imo_multicast_ifp = ifp; 1429 if (ifindex) 1430 imo->imo_multicast_addr = addr; 1431 else 1432 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1433 break; 1434 1435 case IP_MULTICAST_TTL: 1436 /* 1437 * Set the IP time-to-live for outgoing multicast packets. 1438 */ 1439 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1440 break; 1441 1442 case IP_MULTICAST_LOOP: 1443 /* 1444 * Set the loopback flag for outgoing multicast packets. 1445 * Must be zero or one. 1446 */ 1447 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1448 break; 1449 1450 case IP_ADD_MEMBERSHIP: 1451 /* 1452 * Add a multicast group membership. 1453 * Group must be a valid IP multicast address. 1454 */ 1455 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1456 if (error) 1457 break; 1458 1459 mreq = &lmreq; 1460 1461 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1462 error = EINVAL; 1463 break; 1464 } 1465 /* 1466 * If no interface address was provided, use the interface of 1467 * the route to the given multicast address. 1468 */ 1469 if (in_nullhost(mreq->imr_interface)) { 1470 struct rtentry *rt; 1471 union { 1472 struct sockaddr dst; 1473 struct sockaddr_in dst4; 1474 } u; 1475 struct route ro; 1476 1477 memset(&ro, 0, sizeof(ro)); 1478 1479 sockaddr_in_init(&u.dst4, &mreq->imr_multiaddr, 0); 1480 rtcache_setdst(&ro, &u.dst); 1481 ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp 1482 : NULL; 1483 rtcache_free(&ro); 1484 } else { 1485 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1486 } 1487 /* 1488 * See if we found an interface, and confirm that it 1489 * supports multicast. 1490 */ 1491 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1492 error = EADDRNOTAVAIL; 1493 break; 1494 } 1495 /* 1496 * See if the membership already exists or if all the 1497 * membership slots are full. 1498 */ 1499 for (i = 0; i < imo->imo_num_memberships; ++i) { 1500 if (imo->imo_membership[i]->inm_ifp == ifp && 1501 in_hosteq(imo->imo_membership[i]->inm_addr, 1502 mreq->imr_multiaddr)) 1503 break; 1504 } 1505 if (i < imo->imo_num_memberships) { 1506 error = EADDRINUSE; 1507 break; 1508 } 1509 if (i == IP_MAX_MEMBERSHIPS) { 1510 error = ETOOMANYREFS; 1511 break; 1512 } 1513 /* 1514 * Everything looks good; add a new record to the multicast 1515 * address list for the given interface. 1516 */ 1517 if ((imo->imo_membership[i] = 1518 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1519 error = ENOBUFS; 1520 break; 1521 } 1522 ++imo->imo_num_memberships; 1523 break; 1524 1525 case IP_DROP_MEMBERSHIP: 1526 /* 1527 * Drop a multicast group membership. 1528 * Group must be a valid IP multicast address. 1529 */ 1530 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1531 if (error) 1532 break; 1533 1534 mreq = &lmreq; 1535 1536 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1537 error = EINVAL; 1538 break; 1539 } 1540 /* 1541 * If an interface address was specified, get a pointer 1542 * to its ifnet structure. 1543 */ 1544 if (in_nullhost(mreq->imr_interface)) 1545 ifp = NULL; 1546 else { 1547 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1548 if (ifp == NULL) { 1549 error = EADDRNOTAVAIL; 1550 break; 1551 } 1552 } 1553 /* 1554 * Find the membership in the membership array. 1555 */ 1556 for (i = 0; i < imo->imo_num_memberships; ++i) { 1557 if ((ifp == NULL || 1558 imo->imo_membership[i]->inm_ifp == ifp) && 1559 in_hosteq(imo->imo_membership[i]->inm_addr, 1560 mreq->imr_multiaddr)) 1561 break; 1562 } 1563 if (i == imo->imo_num_memberships) { 1564 error = EADDRNOTAVAIL; 1565 break; 1566 } 1567 /* 1568 * Give up the multicast address record to which the 1569 * membership points. 1570 */ 1571 in_delmulti(imo->imo_membership[i]); 1572 /* 1573 * Remove the gap in the membership array. 1574 */ 1575 for (++i; i < imo->imo_num_memberships; ++i) 1576 imo->imo_membership[i-1] = imo->imo_membership[i]; 1577 --imo->imo_num_memberships; 1578 break; 1579 1580 default: 1581 error = EOPNOTSUPP; 1582 break; 1583 } 1584 1585 /* 1586 * If all options have default values, no need to keep the mbuf. 1587 */ 1588 if (imo->imo_multicast_ifp == NULL && 1589 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1590 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1591 imo->imo_num_memberships == 0) { 1592 kmem_free(imo, sizeof(*imo)); 1593 *imop = NULL; 1594 } 1595 1596 return error; 1597 } 1598 1599 /* 1600 * Return the IP multicast options in response to user getsockopt(). 1601 */ 1602 int 1603 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 1604 { 1605 struct in_addr addr; 1606 struct in_ifaddr *ia; 1607 int error; 1608 uint8_t optval; 1609 1610 error = 0; 1611 1612 switch (sopt->sopt_name) { 1613 case IP_MULTICAST_IF: 1614 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1615 addr = zeroin_addr; 1616 else if (imo->imo_multicast_addr.s_addr) { 1617 /* return the value user has set */ 1618 addr = imo->imo_multicast_addr; 1619 } else { 1620 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1621 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1622 } 1623 error = sockopt_set(sopt, &addr, sizeof(addr)); 1624 break; 1625 1626 case IP_MULTICAST_TTL: 1627 optval = imo ? imo->imo_multicast_ttl 1628 : IP_DEFAULT_MULTICAST_TTL; 1629 1630 error = sockopt_set(sopt, &optval, sizeof(optval)); 1631 break; 1632 1633 case IP_MULTICAST_LOOP: 1634 optval = imo ? imo->imo_multicast_loop 1635 : IP_DEFAULT_MULTICAST_LOOP; 1636 1637 error = sockopt_set(sopt, &optval, sizeof(optval)); 1638 break; 1639 1640 default: 1641 error = EOPNOTSUPP; 1642 } 1643 1644 return (error); 1645 } 1646 1647 /* 1648 * Discard the IP multicast options. 1649 */ 1650 void 1651 ip_freemoptions(struct ip_moptions *imo) 1652 { 1653 int i; 1654 1655 if (imo != NULL) { 1656 for (i = 0; i < imo->imo_num_memberships; ++i) 1657 in_delmulti(imo->imo_membership[i]); 1658 kmem_free(imo, sizeof(*imo)); 1659 } 1660 } 1661 1662 /* 1663 * Routine called from ip_output() to loop back a copy of an IP multicast 1664 * packet to the input queue of a specified interface. Note that this 1665 * calls the output routine of the loopback "driver", but with an interface 1666 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1667 */ 1668 static void 1669 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1670 { 1671 struct ip *ip; 1672 struct mbuf *copym; 1673 1674 copym = m_copypacket(m, M_DONTWAIT); 1675 if (copym != NULL 1676 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1677 copym = m_pullup(copym, sizeof(struct ip)); 1678 if (copym == NULL) 1679 return; 1680 /* 1681 * We don't bother to fragment if the IP length is greater 1682 * than the interface's MTU. Can this possibly matter? 1683 */ 1684 ip = mtod(copym, struct ip *); 1685 1686 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1687 in_delayed_cksum(copym); 1688 copym->m_pkthdr.csum_flags &= 1689 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1690 } 1691 1692 ip->ip_sum = 0; 1693 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1694 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1695 } 1696