1 /* $NetBSD: ip_output.c,v 1.230 2014/06/06 00:11:19 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 1.230 2014/06/06 00:11:19 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/kmem.h> 102 #include <sys/mbuf.h> 103 #include <sys/protosw.h> 104 #include <sys/socket.h> 105 #include <sys/socketvar.h> 106 #include <sys/kauth.h> 107 #ifdef IPSEC 108 #include <sys/domain.h> 109 #endif 110 #include <sys/systm.h> 111 112 #include <net/if.h> 113 #include <net/route.h> 114 #include <net/pfil.h> 115 116 #include <netinet/in.h> 117 #include <netinet/in_systm.h> 118 #include <netinet/ip.h> 119 #include <netinet/in_pcb.h> 120 #include <netinet/in_var.h> 121 #include <netinet/ip_var.h> 122 #include <netinet/ip_private.h> 123 #include <netinet/in_offload.h> 124 #include <netinet/portalgo.h> 125 #include <netinet/udp.h> 126 127 #ifdef MROUTING 128 #include <netinet/ip_mroute.h> 129 #endif 130 131 #include <netipsec/ipsec.h> 132 #include <netipsec/key.h> 133 134 static int ip_pcbopts(struct inpcb *, const struct sockopt *); 135 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 136 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 137 static void ip_mloopback(struct ifnet *, struct mbuf *, 138 const struct sockaddr_in *); 139 static int ip_setmoptions(struct inpcb *, const struct sockopt *); 140 static int ip_getmoptions(struct inpcb *, struct sockopt *); 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 mbuf *opt; 165 struct route *ro; 166 int flags, sw_csum; 167 u_long mtu; 168 struct ip_moptions *imo; 169 struct socket *so; 170 va_list ap; 171 #ifdef IPSEC 172 struct secpolicy *sp = NULL; 173 #endif 174 bool natt_frag = false; 175 bool rtmtu_nolock; 176 union { 177 struct sockaddr dst; 178 struct sockaddr_in dst4; 179 } u; 180 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 181 * to the nexthop 182 */ 183 184 len = 0; 185 va_start(ap, m0); 186 opt = va_arg(ap, struct mbuf *); 187 ro = va_arg(ap, struct route *); 188 flags = va_arg(ap, int); 189 imo = va_arg(ap, struct ip_moptions *); 190 so = va_arg(ap, struct socket *); 191 va_end(ap); 192 193 MCLAIM(m, &ip_tx_mowner); 194 195 KASSERT((m->m_flags & M_PKTHDR) != 0); 196 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 197 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 198 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 199 200 if (opt) { 201 m = ip_insertoptions(m, opt, &len); 202 if (len >= sizeof(struct ip)) 203 hlen = len; 204 } 205 ip = mtod(m, struct ip *); 206 207 /* 208 * Fill in IP header. 209 */ 210 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 211 ip->ip_v = IPVERSION; 212 ip->ip_off = htons(0); 213 /* ip->ip_id filled in after we find out source ia */ 214 ip->ip_hl = hlen >> 2; 215 IP_STATINC(IP_STAT_LOCALOUT); 216 } else { 217 hlen = ip->ip_hl << 2; 218 } 219 220 /* 221 * Route packet. 222 */ 223 if (ro == NULL) { 224 memset(&iproute, 0, sizeof(iproute)); 225 ro = &iproute; 226 } 227 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 228 dst = satocsin(rtcache_getdst(ro)); 229 230 /* 231 * If there is a cached route, check that it is to the same 232 * destination and is still up. If not, free it and try again. 233 * The address family should also be checked in case of sharing 234 * the cache with IPv6. 235 */ 236 if (dst && (dst->sin_family != AF_INET || 237 !in_hosteq(dst->sin_addr, ip->ip_dst))) 238 rtcache_free(ro); 239 240 if ((rt = rtcache_validate(ro)) == NULL && 241 (rt = rtcache_update(ro, 1)) == NULL) { 242 dst = &u.dst4; 243 rtcache_setdst(ro, &u.dst); 244 } 245 246 /* 247 * If routing to interface only, short circuit routing lookup. 248 */ 249 if (flags & IP_ROUTETOIF) { 250 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 251 IP_STATINC(IP_STAT_NOROUTE); 252 error = ENETUNREACH; 253 goto bad; 254 } 255 ifp = ia->ia_ifp; 256 mtu = ifp->if_mtu; 257 ip->ip_ttl = 1; 258 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 259 ip->ip_dst.s_addr == INADDR_BROADCAST) && 260 imo != NULL && imo->imo_multicast_ifp != NULL) { 261 ifp = imo->imo_multicast_ifp; 262 mtu = ifp->if_mtu; 263 IFP_TO_IA(ifp, ia); 264 } else { 265 if (rt == NULL) 266 rt = rtcache_init(ro); 267 if (rt == NULL) { 268 IP_STATINC(IP_STAT_NOROUTE); 269 error = EHOSTUNREACH; 270 goto bad; 271 } 272 ia = ifatoia(rt->rt_ifa); 273 ifp = rt->rt_ifp; 274 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 275 mtu = ifp->if_mtu; 276 rt->rt_use++; 277 if (rt->rt_flags & RTF_GATEWAY) 278 dst = satosin(rt->rt_gateway); 279 } 280 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 281 282 if (IN_MULTICAST(ip->ip_dst.s_addr) || 283 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 284 bool inmgroup; 285 286 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 287 M_BCAST : M_MCAST; 288 /* 289 * See if the caller provided any multicast options 290 */ 291 if (imo != NULL) 292 ip->ip_ttl = imo->imo_multicast_ttl; 293 else 294 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 295 296 /* 297 * if we don't know the outgoing ifp yet, we can't generate 298 * output 299 */ 300 if (!ifp) { 301 IP_STATINC(IP_STAT_NOROUTE); 302 error = ENETUNREACH; 303 goto bad; 304 } 305 306 /* 307 * If the packet is multicast or broadcast, confirm that 308 * the outgoing interface can transmit it. 309 */ 310 if (((m->m_flags & M_MCAST) && 311 (ifp->if_flags & IFF_MULTICAST) == 0) || 312 ((m->m_flags & M_BCAST) && 313 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 314 IP_STATINC(IP_STAT_NOROUTE); 315 error = ENETUNREACH; 316 goto bad; 317 } 318 /* 319 * If source address not specified yet, use an address 320 * of outgoing interface. 321 */ 322 if (in_nullhost(ip->ip_src)) { 323 struct in_ifaddr *xia; 324 struct ifaddr *xifa; 325 326 IFP_TO_IA(ifp, xia); 327 if (!xia) { 328 error = EADDRNOTAVAIL; 329 goto bad; 330 } 331 xifa = &xia->ia_ifa; 332 if (xifa->ifa_getifa != NULL) { 333 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 334 } 335 ip->ip_src = xia->ia_addr.sin_addr; 336 } 337 338 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 339 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 340 /* 341 * If we belong to the destination multicast group 342 * on the outgoing interface, and the caller did not 343 * forbid loopback, loop back a copy. 344 */ 345 ip_mloopback(ifp, m, &u.dst4); 346 } 347 #ifdef MROUTING 348 else { 349 /* 350 * If we are acting as a multicast router, perform 351 * multicast forwarding as if the packet had just 352 * arrived on the interface to which we are about 353 * to send. The multicast forwarding function 354 * recursively calls this function, using the 355 * IP_FORWARDING flag to prevent infinite recursion. 356 * 357 * Multicasts that are looped back by ip_mloopback(), 358 * above, will be forwarded by the ip_input() routine, 359 * if necessary. 360 */ 361 extern struct socket *ip_mrouter; 362 363 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 364 if (ip_mforward(m, ifp) != 0) { 365 m_freem(m); 366 goto done; 367 } 368 } 369 } 370 #endif 371 /* 372 * Multicasts with a time-to-live of zero may be looped- 373 * back, above, but must not be transmitted on a network. 374 * Also, multicasts addressed to the loopback interface 375 * are not sent -- the above call to ip_mloopback() will 376 * loop back a copy if this host actually belongs to the 377 * destination group on the loopback interface. 378 */ 379 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 380 m_freem(m); 381 goto done; 382 } 383 goto sendit; 384 } 385 386 /* 387 * If source address not specified yet, use address 388 * of outgoing interface. 389 */ 390 if (in_nullhost(ip->ip_src)) { 391 struct ifaddr *xifa; 392 393 xifa = &ia->ia_ifa; 394 if (xifa->ifa_getifa != NULL) 395 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 396 ip->ip_src = ia->ia_addr.sin_addr; 397 } 398 399 /* 400 * packets with Class-D address as source are not valid per 401 * RFC 1112 402 */ 403 if (IN_MULTICAST(ip->ip_src.s_addr)) { 404 IP_STATINC(IP_STAT_ODROPPED); 405 error = EADDRNOTAVAIL; 406 goto bad; 407 } 408 409 /* 410 * Look for broadcast address and and verify user is allowed to 411 * send such a packet. 412 */ 413 if (in_broadcast(dst->sin_addr, ifp)) { 414 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 415 error = EADDRNOTAVAIL; 416 goto bad; 417 } 418 if ((flags & IP_ALLOWBROADCAST) == 0) { 419 error = EACCES; 420 goto bad; 421 } 422 /* don't allow broadcast messages to be fragmented */ 423 if (ntohs(ip->ip_len) > ifp->if_mtu) { 424 error = EMSGSIZE; 425 goto bad; 426 } 427 m->m_flags |= M_BCAST; 428 } else 429 m->m_flags &= ~M_BCAST; 430 431 sendit: 432 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 433 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 434 ip->ip_id = 0; 435 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 436 ip->ip_id = ip_newid(ia); 437 } else { 438 439 /* 440 * TSO capable interfaces (typically?) increment 441 * ip_id for each segment. 442 * "allocate" enough ids here to increase the chance 443 * for them to be unique. 444 * 445 * note that the following calculation is not 446 * needed to be precise. wasting some ip_id is fine. 447 */ 448 449 unsigned int segsz = m->m_pkthdr.segsz; 450 unsigned int datasz = ntohs(ip->ip_len) - hlen; 451 unsigned int num = howmany(datasz, segsz); 452 453 ip->ip_id = ip_newid_range(ia, num); 454 } 455 } 456 457 /* 458 * If we're doing Path MTU Discovery, we need to set DF unless 459 * the route's MTU is locked. 460 */ 461 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 462 ip->ip_off |= htons(IP_DF); 463 } 464 465 #ifdef IPSEC 466 if (ipsec_used) { 467 bool ipsec_done = false; 468 469 /* Perform IPsec processing, if any. */ 470 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, 471 &ipsec_done); 472 if (error || ipsec_done) 473 goto done; 474 } 475 #endif 476 477 /* 478 * Run through list of hooks for output packets. 479 */ 480 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 481 if (error) 482 goto done; 483 if (m == NULL) 484 goto done; 485 486 ip = mtod(m, struct ip *); 487 hlen = ip->ip_hl << 2; 488 489 m->m_pkthdr.csum_data |= hlen << 16; 490 491 #if IFA_STATS 492 /* 493 * search for the source address structure to 494 * maintain output statistics. 495 */ 496 INADDR_TO_IA(ip->ip_src, ia); 497 #endif 498 499 /* Maybe skip checksums on loopback interfaces. */ 500 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 501 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 502 } 503 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 504 /* 505 * If small enough for mtu of path, or if using TCP segmentation 506 * offload, can just send directly. 507 */ 508 if (ntohs(ip->ip_len) <= mtu || 509 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 510 const struct sockaddr *sa; 511 512 #if IFA_STATS 513 if (ia) 514 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 515 #endif 516 /* 517 * Always initialize the sum to 0! Some HW assisted 518 * checksumming requires this. 519 */ 520 ip->ip_sum = 0; 521 522 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 523 /* 524 * Perform any checksums that the hardware can't do 525 * for us. 526 * 527 * XXX Does any hardware require the {th,uh}_sum 528 * XXX fields to be 0? 529 */ 530 if (sw_csum & M_CSUM_IPv4) { 531 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 532 ip->ip_sum = in_cksum(m, hlen); 533 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 534 } 535 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 536 if (IN_NEED_CHECKSUM(ifp, 537 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 538 in_delayed_cksum(m); 539 } 540 m->m_pkthdr.csum_flags &= 541 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 542 } 543 } 544 545 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 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 = (*ifp->if_output)(ifp, m, sa, rt); 551 KERNEL_UNLOCK_ONE(NULL); 552 } else { 553 error = ip_tso_output(ifp, m, sa, rt); 554 } 555 goto done; 556 } 557 558 /* 559 * We can't use HW checksumming if we're about to 560 * to fragment the packet. 561 * 562 * XXX Some hardware can do this. 563 */ 564 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 565 if (IN_NEED_CHECKSUM(ifp, 566 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 567 in_delayed_cksum(m); 568 } 569 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 570 } 571 572 /* 573 * Too large for interface; fragment if possible. 574 * Must be able to put at least 8 bytes per fragment. 575 */ 576 if (ntohs(ip->ip_off) & IP_DF) { 577 if (flags & IP_RETURNMTU) { 578 struct inpcb *inp; 579 580 KASSERT(so && solocked(so)); 581 inp = sotoinpcb(so); 582 inp->inp_errormtu = mtu; 583 } 584 error = EMSGSIZE; 585 IP_STATINC(IP_STAT_CANTFRAG); 586 goto bad; 587 } 588 589 error = ip_fragment(m, ifp, mtu); 590 if (error) { 591 m = NULL; 592 goto bad; 593 } 594 595 for (; m; m = m0) { 596 m0 = m->m_nextpkt; 597 m->m_nextpkt = 0; 598 if (error) { 599 m_freem(m); 600 continue; 601 } 602 #if IFA_STATS 603 if (ia) 604 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 605 #endif 606 /* 607 * If we get there, the packet has not been handled by 608 * IPsec whereas it should have. Now that it has been 609 * fragmented, re-inject it in ip_output so that IPsec 610 * processing can occur. 611 */ 612 if (natt_frag) { 613 error = ip_output(m, opt, ro, 614 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 615 imo, so); 616 } else { 617 KASSERT((m->m_pkthdr.csum_flags & 618 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 619 KERNEL_LOCK(1, NULL); 620 error = (*ifp->if_output)(ifp, m, 621 (m->m_flags & M_MCAST) ? 622 sintocsa(rdst) : sintocsa(dst), rt); 623 KERNEL_UNLOCK_ONE(NULL); 624 } 625 } 626 if (error == 0) { 627 IP_STATINC(IP_STAT_FRAGMENTED); 628 } 629 done: 630 if (ro == &iproute) { 631 rtcache_free(&iproute); 632 } 633 #ifdef IPSEC 634 if (sp) { 635 KEY_FREESP(&sp); 636 } 637 #endif 638 return error; 639 bad: 640 m_freem(m); 641 goto done; 642 } 643 644 int 645 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 646 { 647 struct ip *ip, *mhip; 648 struct mbuf *m0; 649 int len, hlen, off; 650 int mhlen, firstlen; 651 struct mbuf **mnext; 652 int sw_csum = m->m_pkthdr.csum_flags; 653 int fragments = 0; 654 int s; 655 int error = 0; 656 657 ip = mtod(m, struct ip *); 658 hlen = ip->ip_hl << 2; 659 if (ifp != NULL) 660 sw_csum &= ~ifp->if_csum_flags_tx; 661 662 len = (mtu - hlen) &~ 7; 663 if (len < 8) { 664 m_freem(m); 665 return (EMSGSIZE); 666 } 667 668 firstlen = len; 669 mnext = &m->m_nextpkt; 670 671 /* 672 * Loop through length of segment after first fragment, 673 * make new header and copy data of each part and link onto chain. 674 */ 675 m0 = m; 676 mhlen = sizeof (struct ip); 677 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 678 MGETHDR(m, M_DONTWAIT, MT_HEADER); 679 if (m == 0) { 680 error = ENOBUFS; 681 IP_STATINC(IP_STAT_ODROPPED); 682 goto sendorfree; 683 } 684 MCLAIM(m, m0->m_owner); 685 *mnext = m; 686 mnext = &m->m_nextpkt; 687 m->m_data += max_linkhdr; 688 mhip = mtod(m, struct ip *); 689 *mhip = *ip; 690 /* we must inherit MCAST and BCAST flags */ 691 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 692 if (hlen > sizeof (struct ip)) { 693 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 694 mhip->ip_hl = mhlen >> 2; 695 } 696 m->m_len = mhlen; 697 mhip->ip_off = ((off - hlen) >> 3) + 698 (ntohs(ip->ip_off) & ~IP_MF); 699 if (ip->ip_off & htons(IP_MF)) 700 mhip->ip_off |= IP_MF; 701 if (off + len >= ntohs(ip->ip_len)) 702 len = ntohs(ip->ip_len) - off; 703 else 704 mhip->ip_off |= IP_MF; 705 HTONS(mhip->ip_off); 706 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 707 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 708 if (m->m_next == 0) { 709 error = ENOBUFS; /* ??? */ 710 IP_STATINC(IP_STAT_ODROPPED); 711 goto sendorfree; 712 } 713 m->m_pkthdr.len = mhlen + len; 714 m->m_pkthdr.rcvif = NULL; 715 mhip->ip_sum = 0; 716 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 717 if (sw_csum & M_CSUM_IPv4) { 718 mhip->ip_sum = in_cksum(m, mhlen); 719 } else { 720 /* 721 * checksum is hw-offloaded or not necessary. 722 */ 723 m->m_pkthdr.csum_flags |= 724 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 725 m->m_pkthdr.csum_data |= mhlen << 16; 726 KASSERT(!(ifp != NULL && 727 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 728 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 729 } 730 IP_STATINC(IP_STAT_OFRAGMENTS); 731 fragments++; 732 } 733 /* 734 * Update first fragment by trimming what's been copied out 735 * and updating header, then send each fragment (in order). 736 */ 737 m = m0; 738 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 739 m->m_pkthdr.len = hlen + firstlen; 740 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 741 ip->ip_off |= htons(IP_MF); 742 ip->ip_sum = 0; 743 if (sw_csum & M_CSUM_IPv4) { 744 ip->ip_sum = in_cksum(m, hlen); 745 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 746 } else { 747 /* 748 * checksum is hw-offloaded or not necessary. 749 */ 750 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 751 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 752 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 753 sizeof(struct ip)); 754 } 755 sendorfree: 756 /* 757 * If there is no room for all the fragments, don't queue 758 * any of them. 759 */ 760 if (ifp != NULL) { 761 s = splnet(); 762 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 763 error == 0) { 764 error = ENOBUFS; 765 IP_STATINC(IP_STAT_ODROPPED); 766 IFQ_INC_DROPS(&ifp->if_snd); 767 } 768 splx(s); 769 } 770 if (error) { 771 for (m = m0; m; m = m0) { 772 m0 = m->m_nextpkt; 773 m->m_nextpkt = NULL; 774 m_freem(m); 775 } 776 } 777 return (error); 778 } 779 780 /* 781 * Process a delayed payload checksum calculation. 782 */ 783 void 784 in_delayed_cksum(struct mbuf *m) 785 { 786 struct ip *ip; 787 u_int16_t csum, offset; 788 789 ip = mtod(m, struct ip *); 790 offset = ip->ip_hl << 2; 791 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 792 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 793 csum = 0xffff; 794 795 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 796 797 if ((offset + sizeof(u_int16_t)) > m->m_len) { 798 /* This happen when ip options were inserted 799 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 800 m->m_len, offset, ip->ip_p); 801 */ 802 m_copyback(m, offset, sizeof(csum), (void *) &csum); 803 } else 804 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 805 } 806 807 /* 808 * Determine the maximum length of the options to be inserted; 809 * we would far rather allocate too much space rather than too little. 810 */ 811 812 u_int 813 ip_optlen(struct inpcb *inp) 814 { 815 struct mbuf *m = inp->inp_options; 816 817 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 818 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 819 } 820 return 0; 821 } 822 823 /* 824 * Insert IP options into preformed packet. 825 * Adjust IP destination as required for IP source routing, 826 * as indicated by a non-zero in_addr at the start of the options. 827 */ 828 static struct mbuf * 829 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 830 { 831 struct ipoption *p = mtod(opt, struct ipoption *); 832 struct mbuf *n; 833 struct ip *ip = mtod(m, struct ip *); 834 unsigned optlen; 835 836 optlen = opt->m_len - sizeof(p->ipopt_dst); 837 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 838 return (m); /* XXX should fail */ 839 if (!in_nullhost(p->ipopt_dst)) 840 ip->ip_dst = p->ipopt_dst; 841 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 842 MGETHDR(n, M_DONTWAIT, MT_HEADER); 843 if (n == 0) 844 return (m); 845 MCLAIM(n, m->m_owner); 846 M_MOVE_PKTHDR(n, m); 847 m->m_len -= sizeof(struct ip); 848 m->m_data += sizeof(struct ip); 849 n->m_next = m; 850 m = n; 851 m->m_len = optlen + sizeof(struct ip); 852 m->m_data += max_linkhdr; 853 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 854 } else { 855 m->m_data -= optlen; 856 m->m_len += optlen; 857 memmove(mtod(m, void *), ip, sizeof(struct ip)); 858 } 859 m->m_pkthdr.len += optlen; 860 ip = mtod(m, struct ip *); 861 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 862 *phlen = sizeof(struct ip) + optlen; 863 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 864 return (m); 865 } 866 867 /* 868 * Copy options from ip to jp, 869 * omitting those not copied during fragmentation. 870 */ 871 int 872 ip_optcopy(struct ip *ip, struct ip *jp) 873 { 874 u_char *cp, *dp; 875 int opt, optlen, cnt; 876 877 cp = (u_char *)(ip + 1); 878 dp = (u_char *)(jp + 1); 879 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 880 for (; cnt > 0; cnt -= optlen, cp += optlen) { 881 opt = cp[0]; 882 if (opt == IPOPT_EOL) 883 break; 884 if (opt == IPOPT_NOP) { 885 /* Preserve for IP mcast tunnel's LSRR alignment. */ 886 *dp++ = IPOPT_NOP; 887 optlen = 1; 888 continue; 889 } 890 891 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 892 optlen = cp[IPOPT_OLEN]; 893 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 894 895 /* Invalid lengths should have been caught by ip_dooptions. */ 896 if (optlen > cnt) 897 optlen = cnt; 898 if (IPOPT_COPIED(opt)) { 899 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 900 dp += optlen; 901 } 902 } 903 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 904 *dp++ = IPOPT_EOL; 905 return (optlen); 906 } 907 908 /* 909 * IP socket option processing. 910 */ 911 int 912 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 913 { 914 struct inpcb *inp = sotoinpcb(so); 915 struct ip *ip = &inp->inp_ip; 916 int inpflags = inp->inp_flags; 917 int optval = 0, error = 0; 918 919 if (sopt->sopt_level != IPPROTO_IP) { 920 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 921 return 0; 922 return ENOPROTOOPT; 923 } 924 925 switch (op) { 926 case PRCO_SETOPT: 927 switch (sopt->sopt_name) { 928 case IP_OPTIONS: 929 #ifdef notyet 930 case IP_RETOPTS: 931 #endif 932 error = ip_pcbopts(inp, sopt); 933 break; 934 935 case IP_TOS: 936 case IP_TTL: 937 case IP_MINTTL: 938 case IP_PKTINFO: 939 case IP_RECVOPTS: 940 case IP_RECVRETOPTS: 941 case IP_RECVDSTADDR: 942 case IP_RECVIF: 943 case IP_RECVPKTINFO: 944 case IP_RECVTTL: 945 error = sockopt_getint(sopt, &optval); 946 if (error) 947 break; 948 949 switch (sopt->sopt_name) { 950 case IP_TOS: 951 ip->ip_tos = optval; 952 break; 953 954 case IP_TTL: 955 ip->ip_ttl = optval; 956 break; 957 958 case IP_MINTTL: 959 if (optval > 0 && optval <= MAXTTL) 960 inp->inp_ip_minttl = optval; 961 else 962 error = EINVAL; 963 break; 964 #define OPTSET(bit) \ 965 if (optval) \ 966 inpflags |= bit; \ 967 else \ 968 inpflags &= ~bit; 969 970 case IP_PKTINFO: 971 OPTSET(INP_PKTINFO); 972 break; 973 974 case IP_RECVOPTS: 975 OPTSET(INP_RECVOPTS); 976 break; 977 978 case IP_RECVPKTINFO: 979 OPTSET(INP_RECVPKTINFO); 980 break; 981 982 case IP_RECVRETOPTS: 983 OPTSET(INP_RECVRETOPTS); 984 break; 985 986 case IP_RECVDSTADDR: 987 OPTSET(INP_RECVDSTADDR); 988 break; 989 990 case IP_RECVIF: 991 OPTSET(INP_RECVIF); 992 break; 993 994 case IP_RECVTTL: 995 OPTSET(INP_RECVTTL); 996 break; 997 } 998 break; 999 #undef OPTSET 1000 1001 case IP_MULTICAST_IF: 1002 case IP_MULTICAST_TTL: 1003 case IP_MULTICAST_LOOP: 1004 case IP_ADD_MEMBERSHIP: 1005 case IP_DROP_MEMBERSHIP: 1006 error = ip_setmoptions(inp, sopt); 1007 break; 1008 1009 case IP_PORTRANGE: 1010 error = sockopt_getint(sopt, &optval); 1011 if (error) 1012 break; 1013 1014 switch (optval) { 1015 case IP_PORTRANGE_DEFAULT: 1016 case IP_PORTRANGE_HIGH: 1017 inpflags &= ~(INP_LOWPORT); 1018 break; 1019 1020 case IP_PORTRANGE_LOW: 1021 inpflags |= INP_LOWPORT; 1022 break; 1023 1024 default: 1025 error = EINVAL; 1026 break; 1027 } 1028 break; 1029 1030 case IP_PORTALGO: 1031 error = sockopt_getint(sopt, &optval); 1032 if (error) 1033 break; 1034 1035 error = portalgo_algo_index_select( 1036 (struct inpcb_hdr *)inp, optval); 1037 break; 1038 1039 #if defined(IPSEC) 1040 case IP_IPSEC_POLICY: 1041 if (ipsec_enabled) { 1042 error = ipsec4_set_policy(inp, sopt->sopt_name, 1043 sopt->sopt_data, sopt->sopt_size, 1044 curlwp->l_cred); 1045 break; 1046 } 1047 /*FALLTHROUGH*/ 1048 #endif /* IPSEC */ 1049 1050 default: 1051 error = ENOPROTOOPT; 1052 break; 1053 } 1054 break; 1055 1056 case PRCO_GETOPT: 1057 switch (sopt->sopt_name) { 1058 case IP_OPTIONS: 1059 case IP_RETOPTS: { 1060 struct mbuf *mopts = inp->inp_options; 1061 1062 if (mopts) { 1063 struct mbuf *m; 1064 1065 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1066 if (m == NULL) { 1067 error = ENOBUFS; 1068 break; 1069 } 1070 error = sockopt_setmbuf(sopt, m); 1071 } 1072 break; 1073 } 1074 case IP_PKTINFO: 1075 case IP_TOS: 1076 case IP_TTL: 1077 case IP_MINTTL: 1078 case IP_RECVOPTS: 1079 case IP_RECVRETOPTS: 1080 case IP_RECVDSTADDR: 1081 case IP_RECVIF: 1082 case IP_RECVPKTINFO: 1083 case IP_RECVTTL: 1084 case IP_ERRORMTU: 1085 switch (sopt->sopt_name) { 1086 case IP_TOS: 1087 optval = ip->ip_tos; 1088 break; 1089 1090 case IP_TTL: 1091 optval = ip->ip_ttl; 1092 break; 1093 1094 case IP_MINTTL: 1095 optval = inp->inp_ip_minttl; 1096 break; 1097 1098 case IP_ERRORMTU: 1099 optval = inp->inp_errormtu; 1100 break; 1101 1102 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1103 1104 case IP_PKTINFO: 1105 optval = OPTBIT(INP_PKTINFO); 1106 break; 1107 1108 case IP_RECVOPTS: 1109 optval = OPTBIT(INP_RECVOPTS); 1110 break; 1111 1112 case IP_RECVPKTINFO: 1113 optval = OPTBIT(INP_RECVPKTINFO); 1114 break; 1115 1116 case IP_RECVRETOPTS: 1117 optval = OPTBIT(INP_RECVRETOPTS); 1118 break; 1119 1120 case IP_RECVDSTADDR: 1121 optval = OPTBIT(INP_RECVDSTADDR); 1122 break; 1123 1124 case IP_RECVIF: 1125 optval = OPTBIT(INP_RECVIF); 1126 break; 1127 1128 case IP_RECVTTL: 1129 optval = OPTBIT(INP_RECVTTL); 1130 break; 1131 } 1132 error = sockopt_setint(sopt, optval); 1133 break; 1134 1135 #if 0 /* defined(IPSEC) */ 1136 case IP_IPSEC_POLICY: 1137 { 1138 struct mbuf *m = NULL; 1139 1140 /* XXX this will return EINVAL as sopt is empty */ 1141 error = ipsec4_get_policy(inp, sopt->sopt_data, 1142 sopt->sopt_size, &m); 1143 if (error == 0) 1144 error = sockopt_setmbuf(sopt, m); 1145 break; 1146 } 1147 #endif /*IPSEC*/ 1148 1149 case IP_MULTICAST_IF: 1150 case IP_MULTICAST_TTL: 1151 case IP_MULTICAST_LOOP: 1152 case IP_ADD_MEMBERSHIP: 1153 case IP_DROP_MEMBERSHIP: 1154 error = ip_getmoptions(inp, sopt); 1155 break; 1156 1157 case IP_PORTRANGE: 1158 if (inpflags & INP_LOWPORT) 1159 optval = IP_PORTRANGE_LOW; 1160 else 1161 optval = IP_PORTRANGE_DEFAULT; 1162 error = sockopt_setint(sopt, optval); 1163 break; 1164 1165 case IP_PORTALGO: 1166 optval = inp->inp_portalgo; 1167 error = sockopt_setint(sopt, optval); 1168 break; 1169 1170 default: 1171 error = ENOPROTOOPT; 1172 break; 1173 } 1174 break; 1175 } 1176 1177 if (!error) { 1178 inp->inp_flags = inpflags; 1179 } 1180 return error; 1181 } 1182 1183 /* 1184 * Set up IP options in pcb for insertion in output packets. 1185 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1186 * with destination address if source routed. 1187 */ 1188 static int 1189 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1190 { 1191 struct mbuf *m; 1192 const u_char *cp; 1193 u_char *dp; 1194 int cnt; 1195 1196 /* Turn off any old options. */ 1197 if (inp->inp_options) { 1198 m_free(inp->inp_options); 1199 } 1200 inp->inp_options = NULL; 1201 if ((cnt = sopt->sopt_size) == 0) { 1202 /* Only turning off any previous options. */ 1203 return 0; 1204 } 1205 cp = sopt->sopt_data; 1206 1207 #ifndef __vax__ 1208 if (cnt % sizeof(int32_t)) 1209 return (EINVAL); 1210 #endif 1211 1212 m = m_get(M_DONTWAIT, MT_SOOPTS); 1213 if (m == NULL) 1214 return (ENOBUFS); 1215 1216 dp = mtod(m, u_char *); 1217 memset(dp, 0, sizeof(struct in_addr)); 1218 dp += sizeof(struct in_addr); 1219 m->m_len = sizeof(struct in_addr); 1220 1221 /* 1222 * IP option list according to RFC791. Each option is of the form 1223 * 1224 * [optval] [olen] [(olen - 2) data bytes] 1225 * 1226 * We validate the list and copy options to an mbuf for prepending 1227 * to data packets. The IP first-hop destination address will be 1228 * stored before actual options and is zero if unset. 1229 */ 1230 while (cnt > 0) { 1231 uint8_t optval, olen, offset; 1232 1233 optval = cp[IPOPT_OPTVAL]; 1234 1235 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1236 olen = 1; 1237 } else { 1238 if (cnt < IPOPT_OLEN + 1) 1239 goto bad; 1240 1241 olen = cp[IPOPT_OLEN]; 1242 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1243 goto bad; 1244 } 1245 1246 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1247 /* 1248 * user process specifies route as: 1249 * ->A->B->C->D 1250 * D must be our final destination (but we can't 1251 * check that since we may not have connected yet). 1252 * A is first hop destination, which doesn't appear in 1253 * actual IP option, but is stored before the options. 1254 */ 1255 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1256 goto bad; 1257 1258 offset = cp[IPOPT_OFFSET]; 1259 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1260 sizeof(struct in_addr)); 1261 1262 cp += sizeof(struct in_addr); 1263 cnt -= sizeof(struct in_addr); 1264 olen -= sizeof(struct in_addr); 1265 1266 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1267 goto bad; 1268 1269 memcpy(dp, cp, olen); 1270 dp[IPOPT_OPTVAL] = optval; 1271 dp[IPOPT_OLEN] = olen; 1272 dp[IPOPT_OFFSET] = offset; 1273 break; 1274 } else { 1275 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1276 goto bad; 1277 1278 memcpy(dp, cp, olen); 1279 break; 1280 } 1281 1282 dp += olen; 1283 m->m_len += olen; 1284 1285 if (optval == IPOPT_EOL) 1286 break; 1287 1288 cp += olen; 1289 cnt -= olen; 1290 } 1291 1292 inp->inp_options = m; 1293 return 0; 1294 bad: 1295 (void)m_free(m); 1296 return EINVAL; 1297 } 1298 1299 /* 1300 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1301 */ 1302 static struct ifnet * 1303 ip_multicast_if(struct in_addr *a, int *ifindexp) 1304 { 1305 int ifindex; 1306 struct ifnet *ifp = NULL; 1307 struct in_ifaddr *ia; 1308 1309 if (ifindexp) 1310 *ifindexp = 0; 1311 if (ntohl(a->s_addr) >> 24 == 0) { 1312 ifindex = ntohl(a->s_addr) & 0xffffff; 1313 ifp = if_byindex(ifindex); 1314 if (!ifp) 1315 return NULL; 1316 if (ifindexp) 1317 *ifindexp = ifindex; 1318 } else { 1319 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1320 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1321 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1322 ifp = ia->ia_ifp; 1323 break; 1324 } 1325 } 1326 } 1327 return ifp; 1328 } 1329 1330 static int 1331 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1332 { 1333 u_int tval; 1334 u_char cval; 1335 int error; 1336 1337 if (sopt == NULL) 1338 return EINVAL; 1339 1340 switch (sopt->sopt_size) { 1341 case sizeof(u_char): 1342 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1343 tval = cval; 1344 break; 1345 1346 case sizeof(u_int): 1347 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1348 break; 1349 1350 default: 1351 error = EINVAL; 1352 } 1353 1354 if (error) 1355 return error; 1356 1357 if (tval > maxval) 1358 return EINVAL; 1359 1360 *val = tval; 1361 return 0; 1362 } 1363 1364 /* 1365 * Set the IP multicast options in response to user setsockopt(). 1366 */ 1367 static int 1368 ip_setmoptions(struct inpcb *inp, const struct sockopt *sopt) 1369 { 1370 struct ip_moptions *imo = inp->inp_moptions; 1371 struct in_addr addr; 1372 struct ip_mreq lmreq, *mreq; 1373 struct ifnet *ifp; 1374 int i, ifindex, error = 0; 1375 1376 if (!imo) { 1377 /* 1378 * No multicast option buffer attached to the pcb; 1379 * allocate one and initialize to default values. 1380 */ 1381 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1382 if (imo == NULL) 1383 return ENOBUFS; 1384 1385 imo->imo_multicast_ifp = NULL; 1386 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1387 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1388 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1389 imo->imo_num_memberships = 0; 1390 inp->inp_moptions = imo; 1391 } 1392 1393 switch (sopt->sopt_name) { 1394 case IP_MULTICAST_IF: 1395 /* 1396 * Select the interface for outgoing multicast packets. 1397 */ 1398 error = sockopt_get(sopt, &addr, sizeof(addr)); 1399 if (error) 1400 break; 1401 1402 /* 1403 * INADDR_ANY is used to remove a previous selection. 1404 * When no interface is selected, a default one is 1405 * chosen every time a multicast packet is sent. 1406 */ 1407 if (in_nullhost(addr)) { 1408 imo->imo_multicast_ifp = NULL; 1409 break; 1410 } 1411 /* 1412 * The selected interface is identified by its local 1413 * IP address. Find the interface and confirm that 1414 * it supports multicasting. 1415 */ 1416 ifp = ip_multicast_if(&addr, &ifindex); 1417 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1418 error = EADDRNOTAVAIL; 1419 break; 1420 } 1421 imo->imo_multicast_ifp = ifp; 1422 if (ifindex) 1423 imo->imo_multicast_addr = addr; 1424 else 1425 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1426 break; 1427 1428 case IP_MULTICAST_TTL: 1429 /* 1430 * Set the IP time-to-live for outgoing multicast packets. 1431 */ 1432 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1433 break; 1434 1435 case IP_MULTICAST_LOOP: 1436 /* 1437 * Set the loopback flag for outgoing multicast packets. 1438 * Must be zero or one. 1439 */ 1440 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1441 break; 1442 1443 case IP_ADD_MEMBERSHIP: 1444 /* 1445 * Add a multicast group membership. 1446 * Group must be a valid IP multicast address. 1447 */ 1448 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1449 if (error) 1450 break; 1451 1452 mreq = &lmreq; 1453 1454 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1455 error = EINVAL; 1456 break; 1457 } 1458 /* 1459 * If no interface address was provided, use the interface of 1460 * the route to the given multicast address. 1461 */ 1462 if (in_nullhost(mreq->imr_interface)) { 1463 struct rtentry *rt; 1464 union { 1465 struct sockaddr dst; 1466 struct sockaddr_in dst4; 1467 } u; 1468 struct route ro; 1469 1470 memset(&ro, 0, sizeof(ro)); 1471 1472 sockaddr_in_init(&u.dst4, &mreq->imr_multiaddr, 0); 1473 rtcache_setdst(&ro, &u.dst); 1474 ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp 1475 : NULL; 1476 rtcache_free(&ro); 1477 } else { 1478 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1479 } 1480 /* 1481 * See if we found an interface, and confirm that it 1482 * supports multicast. 1483 */ 1484 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1485 error = EADDRNOTAVAIL; 1486 break; 1487 } 1488 /* 1489 * See if the membership already exists or if all the 1490 * membership slots are full. 1491 */ 1492 for (i = 0; i < imo->imo_num_memberships; ++i) { 1493 if (imo->imo_membership[i]->inm_ifp == ifp && 1494 in_hosteq(imo->imo_membership[i]->inm_addr, 1495 mreq->imr_multiaddr)) 1496 break; 1497 } 1498 if (i < imo->imo_num_memberships) { 1499 error = EADDRINUSE; 1500 break; 1501 } 1502 if (i == IP_MAX_MEMBERSHIPS) { 1503 error = ETOOMANYREFS; 1504 break; 1505 } 1506 /* 1507 * Everything looks good; add a new record to the multicast 1508 * address list for the given interface. 1509 */ 1510 if ((imo->imo_membership[i] = 1511 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1512 error = ENOBUFS; 1513 break; 1514 } 1515 ++imo->imo_num_memberships; 1516 break; 1517 1518 case IP_DROP_MEMBERSHIP: 1519 /* 1520 * Drop a multicast group membership. 1521 * Group must be a valid IP multicast address. 1522 */ 1523 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1524 if (error) 1525 break; 1526 1527 mreq = &lmreq; 1528 1529 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1530 error = EINVAL; 1531 break; 1532 } 1533 /* 1534 * If an interface address was specified, get a pointer 1535 * to its ifnet structure. 1536 */ 1537 if (in_nullhost(mreq->imr_interface)) 1538 ifp = NULL; 1539 else { 1540 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1541 if (ifp == NULL) { 1542 error = EADDRNOTAVAIL; 1543 break; 1544 } 1545 } 1546 /* 1547 * Find the membership in the membership array. 1548 */ 1549 for (i = 0; i < imo->imo_num_memberships; ++i) { 1550 if ((ifp == NULL || 1551 imo->imo_membership[i]->inm_ifp == ifp) && 1552 in_hosteq(imo->imo_membership[i]->inm_addr, 1553 mreq->imr_multiaddr)) 1554 break; 1555 } 1556 if (i == imo->imo_num_memberships) { 1557 error = EADDRNOTAVAIL; 1558 break; 1559 } 1560 /* 1561 * Give up the multicast address record to which the 1562 * membership points. 1563 */ 1564 in_delmulti(imo->imo_membership[i]); 1565 /* 1566 * Remove the gap in the membership array. 1567 */ 1568 for (++i; i < imo->imo_num_memberships; ++i) 1569 imo->imo_membership[i-1] = imo->imo_membership[i]; 1570 --imo->imo_num_memberships; 1571 break; 1572 1573 default: 1574 error = EOPNOTSUPP; 1575 break; 1576 } 1577 1578 /* 1579 * If all options have default values, no need to keep the mbuf. 1580 */ 1581 if (imo->imo_multicast_ifp == NULL && 1582 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1583 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1584 imo->imo_num_memberships == 0) { 1585 kmem_free(imo, sizeof(*imo)); 1586 inp->inp_moptions = NULL; 1587 } 1588 1589 return error; 1590 } 1591 1592 /* 1593 * Return the IP multicast options in response to user getsockopt(). 1594 */ 1595 static int 1596 ip_getmoptions(struct inpcb *inp, struct sockopt *sopt) 1597 { 1598 struct ip_moptions *imo = inp->inp_moptions; 1599 struct in_addr addr; 1600 struct in_ifaddr *ia; 1601 uint8_t optval; 1602 int error = 0; 1603 1604 switch (sopt->sopt_name) { 1605 case IP_MULTICAST_IF: 1606 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1607 addr = zeroin_addr; 1608 else if (imo->imo_multicast_addr.s_addr) { 1609 /* return the value user has set */ 1610 addr = imo->imo_multicast_addr; 1611 } else { 1612 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1613 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1614 } 1615 error = sockopt_set(sopt, &addr, sizeof(addr)); 1616 break; 1617 1618 case IP_MULTICAST_TTL: 1619 optval = imo ? imo->imo_multicast_ttl 1620 : IP_DEFAULT_MULTICAST_TTL; 1621 1622 error = sockopt_set(sopt, &optval, sizeof(optval)); 1623 break; 1624 1625 case IP_MULTICAST_LOOP: 1626 optval = imo ? imo->imo_multicast_loop 1627 : IP_DEFAULT_MULTICAST_LOOP; 1628 1629 error = sockopt_set(sopt, &optval, sizeof(optval)); 1630 break; 1631 1632 default: 1633 error = EOPNOTSUPP; 1634 } 1635 1636 return error; 1637 } 1638 1639 /* 1640 * Discard the IP multicast options. 1641 */ 1642 void 1643 ip_freemoptions(struct ip_moptions *imo) 1644 { 1645 int i; 1646 1647 if (imo != NULL) { 1648 for (i = 0; i < imo->imo_num_memberships; ++i) 1649 in_delmulti(imo->imo_membership[i]); 1650 kmem_free(imo, sizeof(*imo)); 1651 } 1652 } 1653 1654 /* 1655 * Routine called from ip_output() to loop back a copy of an IP multicast 1656 * packet to the input queue of a specified interface. Note that this 1657 * calls the output routine of the loopback "driver", but with an interface 1658 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1659 */ 1660 static void 1661 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1662 { 1663 struct ip *ip; 1664 struct mbuf *copym; 1665 1666 copym = m_copypacket(m, M_DONTWAIT); 1667 if (copym != NULL 1668 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1669 copym = m_pullup(copym, sizeof(struct ip)); 1670 if (copym == NULL) 1671 return; 1672 /* 1673 * We don't bother to fragment if the IP length is greater 1674 * than the interface's MTU. Can this possibly matter? 1675 */ 1676 ip = mtod(copym, struct ip *); 1677 1678 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1679 in_delayed_cksum(copym); 1680 copym->m_pkthdr.csum_flags &= 1681 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1682 } 1683 1684 ip->ip_sum = 0; 1685 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1686 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1687 } 1688