1 /* $NetBSD: ip_output.c,v 1.89 2001/11/13 00:32:39 lukem 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 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the NetBSD 51 * Foundation, Inc. and its contributors. 52 * 4. Neither the name of The NetBSD Foundation nor the names of its 53 * contributors may be used to endorse or promote products derived 54 * from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 /* 70 * Copyright (c) 1982, 1986, 1988, 1990, 1993 71 * The Regents of the University of California. All rights reserved. 72 * 73 * Redistribution and use in source and binary forms, with or without 74 * modification, are permitted provided that the following conditions 75 * are met: 76 * 1. Redistributions of source code must retain the above copyright 77 * notice, this list of conditions and the following disclaimer. 78 * 2. Redistributions in binary form must reproduce the above copyright 79 * notice, this list of conditions and the following disclaimer in the 80 * documentation and/or other materials provided with the distribution. 81 * 3. All advertising materials mentioning features or use of this software 82 * must display the following acknowledgement: 83 * This product includes software developed by the University of 84 * California, Berkeley and its contributors. 85 * 4. Neither the name of the University nor the names of its contributors 86 * may be used to endorse or promote products derived from this software 87 * without specific prior written permission. 88 * 89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 99 * SUCH DAMAGE. 100 * 101 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 102 */ 103 104 #include <sys/cdefs.h> 105 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.89 2001/11/13 00:32:39 lukem Exp $"); 106 107 #include "opt_pfil_hooks.h" 108 #include "opt_ipsec.h" 109 #include "opt_mrouting.h" 110 111 #include <sys/param.h> 112 #include <sys/malloc.h> 113 #include <sys/mbuf.h> 114 #include <sys/errno.h> 115 #include <sys/protosw.h> 116 #include <sys/socket.h> 117 #include <sys/socketvar.h> 118 #include <sys/systm.h> 119 #include <sys/proc.h> 120 121 #include <net/if.h> 122 #include <net/route.h> 123 #include <net/pfil.h> 124 125 #include <netinet/in.h> 126 #include <netinet/in_systm.h> 127 #include <netinet/ip.h> 128 #include <netinet/in_pcb.h> 129 #include <netinet/in_var.h> 130 #include <netinet/ip_var.h> 131 132 #ifdef MROUTING 133 #include <netinet/ip_mroute.h> 134 #endif 135 136 #include <machine/stdarg.h> 137 138 #ifdef IPSEC 139 #include <netinet6/ipsec.h> 140 #include <netkey/key.h> 141 #include <netkey/key_debug.h> 142 #endif /*IPSEC*/ 143 144 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 145 static struct ifnet *ip_multicast_if __P((struct in_addr *, int *)); 146 static void ip_mloopback 147 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); 148 149 #ifdef PFIL_HOOKS 150 extern struct pfil_head inet_pfil_hook; /* XXX */ 151 #endif 152 153 /* 154 * IP output. The packet in mbuf chain m contains a skeletal IP 155 * header (with len, off, ttl, proto, tos, src, dst). 156 * The mbuf chain containing the packet will be freed. 157 * The mbuf opt, if present, will not be freed. 158 */ 159 int 160 #if __STDC__ 161 ip_output(struct mbuf *m0, ...) 162 #else 163 ip_output(m0, va_alist) 164 struct mbuf *m0; 165 va_dcl 166 #endif 167 { 168 struct ip *ip, *mhip; 169 struct ifnet *ifp; 170 struct mbuf *m = m0; 171 int hlen = sizeof (struct ip); 172 int len, off, error = 0; 173 struct route iproute; 174 struct sockaddr_in *dst; 175 struct in_ifaddr *ia; 176 struct mbuf *opt; 177 struct route *ro; 178 int flags, sw_csum; 179 int *mtu_p; 180 int mtu; 181 struct ip_moptions *imo; 182 va_list ap; 183 #ifdef IPSEC 184 struct socket *so; 185 struct secpolicy *sp = NULL; 186 #endif /*IPSEC*/ 187 u_int16_t ip_len; 188 189 va_start(ap, m0); 190 opt = va_arg(ap, struct mbuf *); 191 ro = va_arg(ap, struct route *); 192 flags = va_arg(ap, int); 193 imo = va_arg(ap, struct ip_moptions *); 194 if (flags & IP_RETURNMTU) 195 mtu_p = va_arg(ap, int *); 196 else 197 mtu_p = NULL; 198 va_end(ap); 199 200 #ifdef IPSEC 201 so = ipsec_getsocket(m); 202 (void)ipsec_setsocket(m, NULL); 203 #endif /*IPSEC*/ 204 205 #ifdef DIAGNOSTIC 206 if ((m->m_flags & M_PKTHDR) == 0) 207 panic("ip_output no HDR"); 208 #endif 209 if (opt) { 210 m = ip_insertoptions(m, opt, &len); 211 hlen = len; 212 } 213 ip = mtod(m, struct ip *); 214 /* 215 * Fill in IP header. 216 */ 217 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 218 ip->ip_v = IPVERSION; 219 ip->ip_off = 0; 220 ip->ip_id = htons(ip_id++); 221 ip->ip_hl = hlen >> 2; 222 ipstat.ips_localout++; 223 } else { 224 hlen = ip->ip_hl << 2; 225 } 226 /* 227 * Route packet. 228 */ 229 if (ro == 0) { 230 ro = &iproute; 231 bzero((caddr_t)ro, sizeof (*ro)); 232 } 233 dst = satosin(&ro->ro_dst); 234 /* 235 * If there is a cached route, 236 * check that it is to the same destination 237 * and is still up. If not, free it and try again. 238 */ 239 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 240 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 241 RTFREE(ro->ro_rt); 242 ro->ro_rt = (struct rtentry *)0; 243 } 244 if (ro->ro_rt == 0) { 245 dst->sin_family = AF_INET; 246 dst->sin_len = sizeof(*dst); 247 dst->sin_addr = ip->ip_dst; 248 } 249 /* 250 * If routing to interface only, 251 * short circuit routing lookup. 252 */ 253 if (flags & IP_ROUTETOIF) { 254 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 255 ipstat.ips_noroute++; 256 error = ENETUNREACH; 257 goto bad; 258 } 259 ifp = ia->ia_ifp; 260 mtu = ifp->if_mtu; 261 ip->ip_ttl = 1; 262 } else { 263 if (ro->ro_rt == 0) 264 rtalloc(ro); 265 if (ro->ro_rt == 0) { 266 ipstat.ips_noroute++; 267 error = EHOSTUNREACH; 268 goto bad; 269 } 270 ia = ifatoia(ro->ro_rt->rt_ifa); 271 ifp = ro->ro_rt->rt_ifp; 272 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 273 mtu = ifp->if_mtu; 274 ro->ro_rt->rt_use++; 275 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 276 dst = satosin(ro->ro_rt->rt_gateway); 277 } 278 if (IN_MULTICAST(ip->ip_dst.s_addr) || 279 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 280 struct in_multi *inm; 281 282 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 283 M_BCAST : M_MCAST; 284 /* 285 * IP destination address is multicast. Make sure "dst" 286 * still points to the address in "ro". (It may have been 287 * changed to point to a gateway address, above.) 288 */ 289 dst = satosin(&ro->ro_dst); 290 /* 291 * See if the caller provided any multicast options 292 */ 293 if (imo != NULL) { 294 ip->ip_ttl = imo->imo_multicast_ttl; 295 if (imo->imo_multicast_ifp != NULL) { 296 ifp = imo->imo_multicast_ifp; 297 mtu = ifp->if_mtu; 298 } 299 } else 300 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 301 /* 302 * Confirm that the outgoing interface supports multicast. 303 */ 304 if (((m->m_flags & M_MCAST) && 305 (ifp->if_flags & IFF_MULTICAST) == 0) || 306 ((m->m_flags & M_BCAST) && 307 (ifp->if_flags & IFF_BROADCAST) == 0)) { 308 ipstat.ips_noroute++; 309 error = ENETUNREACH; 310 goto bad; 311 } 312 /* 313 * If source address not specified yet, use an address 314 * of outgoing interface. 315 */ 316 if (in_nullhost(ip->ip_src)) { 317 struct in_ifaddr *ia; 318 319 IFP_TO_IA(ifp, ia); 320 ip->ip_src = ia->ia_addr.sin_addr; 321 } 322 323 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 324 if (inm != NULL && 325 (imo == NULL || imo->imo_multicast_loop)) { 326 /* 327 * If we belong to the destination multicast group 328 * on the outgoing interface, and the caller did not 329 * forbid loopback, loop back a copy. 330 */ 331 ip_mloopback(ifp, m, dst); 332 } 333 #ifdef MROUTING 334 else { 335 /* 336 * If we are acting as a multicast router, perform 337 * multicast forwarding as if the packet had just 338 * arrived on the interface to which we are about 339 * to send. The multicast forwarding function 340 * recursively calls this function, using the 341 * IP_FORWARDING flag to prevent infinite recursion. 342 * 343 * Multicasts that are looped back by ip_mloopback(), 344 * above, will be forwarded by the ip_input() routine, 345 * if necessary. 346 */ 347 extern struct socket *ip_mrouter; 348 349 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 350 if (ip_mforward(m, ifp) != 0) { 351 m_freem(m); 352 goto done; 353 } 354 } 355 } 356 #endif 357 /* 358 * Multicasts with a time-to-live of zero may be looped- 359 * back, above, but must not be transmitted on a network. 360 * Also, multicasts addressed to the loopback interface 361 * are not sent -- the above call to ip_mloopback() will 362 * loop back a copy if this host actually belongs to the 363 * destination group on the loopback interface. 364 */ 365 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 366 m_freem(m); 367 goto done; 368 } 369 370 goto sendit; 371 } 372 #ifndef notdef 373 /* 374 * If source address not specified yet, use address 375 * of outgoing interface. 376 */ 377 if (in_nullhost(ip->ip_src)) 378 ip->ip_src = ia->ia_addr.sin_addr; 379 #endif 380 381 /* 382 * packets with Class-D address as source are not valid per 383 * RFC 1112 384 */ 385 if (IN_MULTICAST(ip->ip_src.s_addr)) { 386 ipstat.ips_odropped++; 387 error = EADDRNOTAVAIL; 388 goto bad; 389 } 390 391 /* 392 * Look for broadcast address and 393 * and verify user is allowed to send 394 * such a packet. 395 */ 396 if (in_broadcast(dst->sin_addr, ifp)) { 397 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 398 error = EADDRNOTAVAIL; 399 goto bad; 400 } 401 if ((flags & IP_ALLOWBROADCAST) == 0) { 402 error = EACCES; 403 goto bad; 404 } 405 /* don't allow broadcast messages to be fragmented */ 406 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 407 error = EMSGSIZE; 408 goto bad; 409 } 410 m->m_flags |= M_BCAST; 411 } else 412 m->m_flags &= ~M_BCAST; 413 414 sendit: 415 /* 416 * If we're doing Path MTU Discovery, we need to set DF unless 417 * the route's MTU is locked. 418 */ 419 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 420 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 421 ip->ip_off |= IP_DF; 422 423 /* 424 * Remember the current ip_len and ip_off, and swap them into 425 * network order. 426 */ 427 ip_len = ip->ip_len; 428 429 HTONS(ip->ip_len); 430 HTONS(ip->ip_off); 431 432 #ifdef IPSEC 433 /* get SP for this packet */ 434 if (so == NULL) 435 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 436 else 437 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 438 439 if (sp == NULL) { 440 ipsecstat.out_inval++; 441 goto bad; 442 } 443 444 error = 0; 445 446 /* check policy */ 447 switch (sp->policy) { 448 case IPSEC_POLICY_DISCARD: 449 /* 450 * This packet is just discarded. 451 */ 452 ipsecstat.out_polvio++; 453 goto bad; 454 455 case IPSEC_POLICY_BYPASS: 456 case IPSEC_POLICY_NONE: 457 /* no need to do IPsec. */ 458 goto skip_ipsec; 459 460 case IPSEC_POLICY_IPSEC: 461 if (sp->req == NULL) { 462 /* XXX should be panic ? */ 463 printf("ip_output: No IPsec request specified.\n"); 464 error = EINVAL; 465 goto bad; 466 } 467 break; 468 469 case IPSEC_POLICY_ENTRUST: 470 default: 471 printf("ip_output: Invalid policy found. %d\n", sp->policy); 472 } 473 474 /* 475 * ipsec4_output() expects ip_len and ip_off in network 476 * order. They have been set to network order above. 477 */ 478 479 { 480 struct ipsec_output_state state; 481 bzero(&state, sizeof(state)); 482 state.m = m; 483 if (flags & IP_ROUTETOIF) { 484 state.ro = &iproute; 485 bzero(&iproute, sizeof(iproute)); 486 } else 487 state.ro = ro; 488 state.dst = (struct sockaddr *)dst; 489 490 /* 491 * We can't defer the checksum of payload data if 492 * we're about to encrypt/authenticate it. 493 * 494 * XXX When we support crypto offloading functions of 495 * XXX network interfaces, we need to reconsider this, 496 * XXX since it's likely that they'll support checksumming, 497 * XXX as well. 498 */ 499 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 500 in_delayed_cksum(m); 501 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 502 } 503 504 error = ipsec4_output(&state, sp, flags); 505 506 m = state.m; 507 if (flags & IP_ROUTETOIF) { 508 /* 509 * if we have tunnel mode SA, we may need to ignore 510 * IP_ROUTETOIF. 511 */ 512 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 513 flags &= ~IP_ROUTETOIF; 514 ro = state.ro; 515 } 516 } else 517 ro = state.ro; 518 dst = (struct sockaddr_in *)state.dst; 519 if (error) { 520 /* mbuf is already reclaimed in ipsec4_output. */ 521 m0 = NULL; 522 switch (error) { 523 case EHOSTUNREACH: 524 case ENETUNREACH: 525 case EMSGSIZE: 526 case ENOBUFS: 527 case ENOMEM: 528 break; 529 default: 530 printf("ip4_output (ipsec): error code %d\n", error); 531 /*fall through*/ 532 case ENOENT: 533 /* don't show these error codes to the user */ 534 error = 0; 535 break; 536 } 537 goto bad; 538 } 539 } 540 541 /* be sure to update variables that are affected by ipsec4_output() */ 542 ip = mtod(m, struct ip *); 543 #ifdef _IP_VHL 544 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 545 #else 546 hlen = ip->ip_hl << 2; 547 #endif 548 ip_len = ntohs(ip->ip_len); 549 550 if (ro->ro_rt == NULL) { 551 if ((flags & IP_ROUTETOIF) == 0) { 552 printf("ip_output: " 553 "can't update route after IPsec processing\n"); 554 error = EHOSTUNREACH; /*XXX*/ 555 goto bad; 556 } 557 } else { 558 /* nobody uses ia beyond here */ 559 ifp = ro->ro_rt->rt_ifp; 560 } 561 562 skip_ipsec: 563 #endif /*IPSEC*/ 564 565 #ifdef PFIL_HOOKS 566 /* 567 * Run through list of hooks for output packets. 568 */ 569 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 570 PFIL_OUT)) != 0) 571 goto done; 572 if (m == NULL) 573 goto done; 574 575 ip = mtod(m, struct ip *); 576 #endif /* PFIL_HOOKS */ 577 578 /* 579 * If small enough for mtu of path, can just send directly. 580 */ 581 if (ip_len <= mtu) { 582 #if IFA_STATS 583 /* 584 * search for the source address structure to 585 * maintain output statistics. 586 */ 587 INADDR_TO_IA(ip->ip_src, ia); 588 if (ia) 589 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 590 #endif 591 /* 592 * Always initialize the sum to 0! Some HW assisted 593 * checksumming requires this. 594 */ 595 ip->ip_sum = 0; 596 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 597 598 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 599 600 /* 601 * Perform any checksums that the hardware can't do 602 * for us. 603 * 604 * XXX Does any hardware require the {th,uh}_sum 605 * XXX fields to be 0? 606 */ 607 if (sw_csum & M_CSUM_IPv4) 608 ip->ip_sum = in_cksum(m, hlen); 609 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 610 in_delayed_cksum(m); 611 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 612 } 613 m->m_pkthdr.csum_flags &= ifp->if_csum_flags_tx; 614 615 #ifdef IPSEC 616 /* clean ipsec history once it goes out of the node */ 617 ipsec_delaux(m); 618 #endif 619 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 620 goto done; 621 } 622 623 /* 624 * We can't use HW checksumming if we're about to 625 * to fragment the packet. 626 * 627 * XXX Some hardware can do this. 628 */ 629 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 630 in_delayed_cksum(m); 631 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 632 } 633 634 /* 635 * Too large for interface; fragment if possible. 636 * Must be able to put at least 8 bytes per fragment. 637 * 638 * Note we swap ip_len and ip_off into host order to make 639 * the logic below a little simpler. 640 */ 641 642 NTOHS(ip->ip_len); 643 NTOHS(ip->ip_off); 644 645 if (ip->ip_off & IP_DF) { 646 if (flags & IP_RETURNMTU) 647 *mtu_p = mtu; 648 error = EMSGSIZE; 649 ipstat.ips_cantfrag++; 650 goto bad; 651 } 652 len = (mtu - hlen) &~ 7; 653 if (len < 8) { 654 error = EMSGSIZE; 655 goto bad; 656 } 657 658 { 659 int mhlen, firstlen = len; 660 struct mbuf **mnext = &m->m_nextpkt; 661 int fragments = 0; 662 int s; 663 664 /* 665 * Loop through length of segment after first fragment, 666 * make new header and copy data of each part and link onto chain. 667 */ 668 m0 = m; 669 mhlen = sizeof (struct ip); 670 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 671 MGETHDR(m, M_DONTWAIT, MT_HEADER); 672 if (m == 0) { 673 error = ENOBUFS; 674 ipstat.ips_odropped++; 675 goto sendorfree; 676 } 677 *mnext = m; 678 mnext = &m->m_nextpkt; 679 m->m_data += max_linkhdr; 680 mhip = mtod(m, struct ip *); 681 *mhip = *ip; 682 /* we must inherit MCAST and BCAST flags */ 683 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 684 if (hlen > sizeof (struct ip)) { 685 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 686 mhip->ip_hl = mhlen >> 2; 687 } 688 m->m_len = mhlen; 689 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 690 if (ip->ip_off & IP_MF) 691 mhip->ip_off |= IP_MF; 692 if (off + len >= (u_int16_t)ip->ip_len) 693 len = (u_int16_t)ip->ip_len - off; 694 else 695 mhip->ip_off |= IP_MF; 696 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 697 m->m_next = m_copy(m0, off, len); 698 if (m->m_next == 0) { 699 error = ENOBUFS; /* ??? */ 700 ipstat.ips_odropped++; 701 goto sendorfree; 702 } 703 m->m_pkthdr.len = mhlen + len; 704 m->m_pkthdr.rcvif = (struct ifnet *)0; 705 HTONS(mhip->ip_off); 706 mhip->ip_sum = 0; 707 mhip->ip_sum = in_cksum(m, mhlen); 708 ipstat.ips_ofragments++; 709 fragments++; 710 } 711 /* 712 * Update first fragment by trimming what's been copied out 713 * and updating header, then send each fragment (in order). 714 */ 715 m = m0; 716 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 717 m->m_pkthdr.len = hlen + firstlen; 718 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 719 ip->ip_off |= IP_MF; 720 HTONS(ip->ip_off); 721 ip->ip_sum = 0; 722 ip->ip_sum = in_cksum(m, hlen); 723 sendorfree: 724 /* 725 * If there is no room for all the fragments, don't queue 726 * any of them. 727 */ 728 s = splnet(); 729 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 730 error = ENOBUFS; 731 splx(s); 732 for (m = m0; m; m = m0) { 733 m0 = m->m_nextpkt; 734 m->m_nextpkt = 0; 735 if (error == 0) { 736 #if IFA_STATS 737 /* 738 * search for the source address structure to 739 * maintain output statistics. 740 */ 741 INADDR_TO_IA(ip->ip_src, ia); 742 if (ia) { 743 ia->ia_ifa.ifa_data.ifad_outbytes += 744 ntohs(ip->ip_len); 745 } 746 #endif 747 #ifdef IPSEC 748 /* clean ipsec history once it goes out of the node */ 749 ipsec_delaux(m); 750 #endif 751 error = (*ifp->if_output)(ifp, m, sintosa(dst), 752 ro->ro_rt); 753 } else 754 m_freem(m); 755 } 756 757 if (error == 0) 758 ipstat.ips_fragmented++; 759 } 760 done: 761 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 762 RTFREE(ro->ro_rt); 763 ro->ro_rt = 0; 764 } 765 766 #ifdef IPSEC 767 if (sp != NULL) { 768 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 769 printf("DP ip_output call free SP:%p\n", sp)); 770 key_freesp(sp); 771 } 772 #endif /* IPSEC */ 773 774 return (error); 775 bad: 776 m_freem(m); 777 goto done; 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->m_pkthdr.csum_data; /* checksum offset */ 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), (caddr_t) &csum); 803 } else 804 *(u_int16_t *)(mtod(m, caddr_t) + 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(inp) 814 struct inpcb *inp; 815 { 816 struct mbuf *m = inp->inp_options; 817 818 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 819 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 820 else 821 return 0; 822 } 823 824 825 /* 826 * Insert IP options into preformed packet. 827 * Adjust IP destination as required for IP source routing, 828 * as indicated by a non-zero in_addr at the start of the options. 829 */ 830 static struct mbuf * 831 ip_insertoptions(m, opt, phlen) 832 struct mbuf *m; 833 struct mbuf *opt; 834 int *phlen; 835 { 836 struct ipoption *p = mtod(opt, struct ipoption *); 837 struct mbuf *n; 838 struct ip *ip = mtod(m, struct ip *); 839 unsigned optlen; 840 841 optlen = opt->m_len - sizeof(p->ipopt_dst); 842 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 843 return (m); /* XXX should fail */ 844 if (!in_nullhost(p->ipopt_dst)) 845 ip->ip_dst = p->ipopt_dst; 846 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 847 MGETHDR(n, M_DONTWAIT, MT_HEADER); 848 if (n == 0) 849 return (m); 850 M_COPY_PKTHDR(n, m); 851 m->m_flags &= ~M_PKTHDR; 852 m->m_len -= sizeof(struct ip); 853 m->m_data += sizeof(struct ip); 854 n->m_next = m; 855 m = n; 856 m->m_len = optlen + sizeof(struct ip); 857 m->m_data += max_linkhdr; 858 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 859 } else { 860 m->m_data -= optlen; 861 m->m_len += optlen; 862 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 863 } 864 m->m_pkthdr.len += optlen; 865 ip = mtod(m, struct ip *); 866 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 867 *phlen = sizeof(struct ip) + optlen; 868 ip->ip_len += optlen; 869 return (m); 870 } 871 872 /* 873 * Copy options from ip to jp, 874 * omitting those not copied during fragmentation. 875 */ 876 int 877 ip_optcopy(ip, jp) 878 struct ip *ip, *jp; 879 { 880 u_char *cp, *dp; 881 int opt, optlen, cnt; 882 883 cp = (u_char *)(ip + 1); 884 dp = (u_char *)(jp + 1); 885 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 886 for (; cnt > 0; cnt -= optlen, cp += optlen) { 887 opt = cp[0]; 888 if (opt == IPOPT_EOL) 889 break; 890 if (opt == IPOPT_NOP) { 891 /* Preserve for IP mcast tunnel's LSRR alignment. */ 892 *dp++ = IPOPT_NOP; 893 optlen = 1; 894 continue; 895 } 896 #ifdef DIAGNOSTIC 897 if (cnt < IPOPT_OLEN + sizeof(*cp)) 898 panic("malformed IPv4 option passed to ip_optcopy"); 899 #endif 900 optlen = cp[IPOPT_OLEN]; 901 #ifdef DIAGNOSTIC 902 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 903 panic("malformed IPv4 option passed to ip_optcopy"); 904 #endif 905 /* bogus lengths should have been caught by ip_dooptions */ 906 if (optlen > cnt) 907 optlen = cnt; 908 if (IPOPT_COPIED(opt)) { 909 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 910 dp += optlen; 911 } 912 } 913 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 914 *dp++ = IPOPT_EOL; 915 return (optlen); 916 } 917 918 /* 919 * IP socket option processing. 920 */ 921 int 922 ip_ctloutput(op, so, level, optname, mp) 923 int op; 924 struct socket *so; 925 int level, optname; 926 struct mbuf **mp; 927 { 928 struct inpcb *inp = sotoinpcb(so); 929 struct mbuf *m = *mp; 930 int optval = 0; 931 int error = 0; 932 #ifdef IPSEC 933 #ifdef __NetBSD__ 934 struct proc *p = curproc; /*XXX*/ 935 #endif 936 #endif 937 938 if (level != IPPROTO_IP) { 939 error = EINVAL; 940 if (op == PRCO_SETOPT && *mp) 941 (void) m_free(*mp); 942 } else switch (op) { 943 944 case PRCO_SETOPT: 945 switch (optname) { 946 case IP_OPTIONS: 947 #ifdef notyet 948 case IP_RETOPTS: 949 return (ip_pcbopts(optname, &inp->inp_options, m)); 950 #else 951 return (ip_pcbopts(&inp->inp_options, m)); 952 #endif 953 954 case IP_TOS: 955 case IP_TTL: 956 case IP_RECVOPTS: 957 case IP_RECVRETOPTS: 958 case IP_RECVDSTADDR: 959 case IP_RECVIF: 960 if (m == NULL || m->m_len != sizeof(int)) 961 error = EINVAL; 962 else { 963 optval = *mtod(m, int *); 964 switch (optname) { 965 966 case IP_TOS: 967 inp->inp_ip.ip_tos = optval; 968 break; 969 970 case IP_TTL: 971 inp->inp_ip.ip_ttl = optval; 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_RECVOPTS: 980 OPTSET(INP_RECVOPTS); 981 break; 982 983 case IP_RECVRETOPTS: 984 OPTSET(INP_RECVRETOPTS); 985 break; 986 987 case IP_RECVDSTADDR: 988 OPTSET(INP_RECVDSTADDR); 989 break; 990 991 case IP_RECVIF: 992 OPTSET(INP_RECVIF); 993 break; 994 } 995 } 996 break; 997 #undef OPTSET 998 999 case IP_MULTICAST_IF: 1000 case IP_MULTICAST_TTL: 1001 case IP_MULTICAST_LOOP: 1002 case IP_ADD_MEMBERSHIP: 1003 case IP_DROP_MEMBERSHIP: 1004 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1005 break; 1006 1007 case IP_PORTRANGE: 1008 if (m == 0 || m->m_len != sizeof(int)) 1009 error = EINVAL; 1010 else { 1011 optval = *mtod(m, int *); 1012 1013 switch (optval) { 1014 1015 case IP_PORTRANGE_DEFAULT: 1016 case IP_PORTRANGE_HIGH: 1017 inp->inp_flags &= ~(INP_LOWPORT); 1018 break; 1019 1020 case IP_PORTRANGE_LOW: 1021 inp->inp_flags |= INP_LOWPORT; 1022 break; 1023 1024 default: 1025 error = EINVAL; 1026 break; 1027 } 1028 } 1029 break; 1030 1031 #ifdef IPSEC 1032 case IP_IPSEC_POLICY: 1033 { 1034 caddr_t req = NULL; 1035 size_t len = 0; 1036 int priv = 0; 1037 1038 #ifdef __NetBSD__ 1039 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1040 priv = 0; 1041 else 1042 priv = 1; 1043 #else 1044 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1045 #endif 1046 if (m) { 1047 req = mtod(m, caddr_t); 1048 len = m->m_len; 1049 } 1050 error = ipsec4_set_policy(inp, optname, req, len, priv); 1051 break; 1052 } 1053 #endif /*IPSEC*/ 1054 1055 default: 1056 error = ENOPROTOOPT; 1057 break; 1058 } 1059 if (m) 1060 (void)m_free(m); 1061 break; 1062 1063 case PRCO_GETOPT: 1064 switch (optname) { 1065 case IP_OPTIONS: 1066 case IP_RETOPTS: 1067 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1068 if (inp->inp_options) { 1069 m->m_len = inp->inp_options->m_len; 1070 bcopy(mtod(inp->inp_options, caddr_t), 1071 mtod(m, caddr_t), (unsigned)m->m_len); 1072 } else 1073 m->m_len = 0; 1074 break; 1075 1076 case IP_TOS: 1077 case IP_TTL: 1078 case IP_RECVOPTS: 1079 case IP_RECVRETOPTS: 1080 case IP_RECVDSTADDR: 1081 case IP_RECVIF: 1082 case IP_ERRORMTU: 1083 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1084 m->m_len = sizeof(int); 1085 switch (optname) { 1086 1087 case IP_TOS: 1088 optval = inp->inp_ip.ip_tos; 1089 break; 1090 1091 case IP_TTL: 1092 optval = inp->inp_ip.ip_ttl; 1093 break; 1094 1095 case IP_ERRORMTU: 1096 optval = inp->inp_errormtu; 1097 break; 1098 1099 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1100 1101 case IP_RECVOPTS: 1102 optval = OPTBIT(INP_RECVOPTS); 1103 break; 1104 1105 case IP_RECVRETOPTS: 1106 optval = OPTBIT(INP_RECVRETOPTS); 1107 break; 1108 1109 case IP_RECVDSTADDR: 1110 optval = OPTBIT(INP_RECVDSTADDR); 1111 break; 1112 1113 case IP_RECVIF: 1114 optval = OPTBIT(INP_RECVIF); 1115 break; 1116 } 1117 *mtod(m, int *) = optval; 1118 break; 1119 1120 #ifdef IPSEC 1121 case IP_IPSEC_POLICY: 1122 { 1123 caddr_t req = NULL; 1124 size_t len = 0; 1125 1126 if (m) { 1127 req = mtod(m, caddr_t); 1128 len = m->m_len; 1129 } 1130 error = ipsec4_get_policy(inp, req, len, mp); 1131 break; 1132 } 1133 #endif /*IPSEC*/ 1134 1135 case IP_MULTICAST_IF: 1136 case IP_MULTICAST_TTL: 1137 case IP_MULTICAST_LOOP: 1138 case IP_ADD_MEMBERSHIP: 1139 case IP_DROP_MEMBERSHIP: 1140 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1141 break; 1142 1143 case IP_PORTRANGE: 1144 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1145 m->m_len = sizeof(int); 1146 1147 if (inp->inp_flags & INP_LOWPORT) 1148 optval = IP_PORTRANGE_LOW; 1149 else 1150 optval = IP_PORTRANGE_DEFAULT; 1151 1152 *mtod(m, int *) = optval; 1153 break; 1154 1155 default: 1156 error = ENOPROTOOPT; 1157 break; 1158 } 1159 break; 1160 } 1161 return (error); 1162 } 1163 1164 /* 1165 * Set up IP options in pcb for insertion in output packets. 1166 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1167 * with destination address if source routed. 1168 */ 1169 int 1170 #ifdef notyet 1171 ip_pcbopts(optname, pcbopt, m) 1172 int optname; 1173 #else 1174 ip_pcbopts(pcbopt, m) 1175 #endif 1176 struct mbuf **pcbopt; 1177 struct mbuf *m; 1178 { 1179 int cnt, optlen; 1180 u_char *cp; 1181 u_char opt; 1182 1183 /* turn off any old options */ 1184 if (*pcbopt) 1185 (void)m_free(*pcbopt); 1186 *pcbopt = 0; 1187 if (m == (struct mbuf *)0 || m->m_len == 0) { 1188 /* 1189 * Only turning off any previous options. 1190 */ 1191 if (m) 1192 (void)m_free(m); 1193 return (0); 1194 } 1195 1196 #ifndef __vax__ 1197 if (m->m_len % sizeof(int32_t)) 1198 goto bad; 1199 #endif 1200 /* 1201 * IP first-hop destination address will be stored before 1202 * actual options; move other options back 1203 * and clear it when none present. 1204 */ 1205 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1206 goto bad; 1207 cnt = m->m_len; 1208 m->m_len += sizeof(struct in_addr); 1209 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1210 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1211 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1212 1213 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1214 opt = cp[IPOPT_OPTVAL]; 1215 if (opt == IPOPT_EOL) 1216 break; 1217 if (opt == IPOPT_NOP) 1218 optlen = 1; 1219 else { 1220 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1221 goto bad; 1222 optlen = cp[IPOPT_OLEN]; 1223 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1224 goto bad; 1225 } 1226 switch (opt) { 1227 1228 default: 1229 break; 1230 1231 case IPOPT_LSRR: 1232 case IPOPT_SSRR: 1233 /* 1234 * user process specifies route as: 1235 * ->A->B->C->D 1236 * D must be our final destination (but we can't 1237 * check that since we may not have connected yet). 1238 * A is first hop destination, which doesn't appear in 1239 * actual IP option, but is stored before the options. 1240 */ 1241 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1242 goto bad; 1243 m->m_len -= sizeof(struct in_addr); 1244 cnt -= sizeof(struct in_addr); 1245 optlen -= sizeof(struct in_addr); 1246 cp[IPOPT_OLEN] = optlen; 1247 /* 1248 * Move first hop before start of options. 1249 */ 1250 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1251 sizeof(struct in_addr)); 1252 /* 1253 * Then copy rest of options back 1254 * to close up the deleted entry. 1255 */ 1256 memmove(&cp[IPOPT_OFFSET+1], 1257 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1258 (unsigned)cnt + sizeof(struct in_addr)); 1259 break; 1260 } 1261 } 1262 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1263 goto bad; 1264 *pcbopt = m; 1265 return (0); 1266 1267 bad: 1268 (void)m_free(m); 1269 return (EINVAL); 1270 } 1271 1272 /* 1273 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1274 */ 1275 static struct ifnet * 1276 ip_multicast_if(a, ifindexp) 1277 struct in_addr *a; 1278 int *ifindexp; 1279 { 1280 int ifindex; 1281 struct ifnet *ifp; 1282 1283 if (ifindexp) 1284 *ifindexp = 0; 1285 if (ntohl(a->s_addr) >> 24 == 0) { 1286 ifindex = ntohl(a->s_addr) & 0xffffff; 1287 if (ifindex < 0 || if_index < ifindex) 1288 return NULL; 1289 ifp = ifindex2ifnet[ifindex]; 1290 if (ifindexp) 1291 *ifindexp = ifindex; 1292 } else { 1293 INADDR_TO_IFP(*a, ifp); 1294 } 1295 return ifp; 1296 } 1297 1298 /* 1299 * Set the IP multicast options in response to user setsockopt(). 1300 */ 1301 int 1302 ip_setmoptions(optname, imop, m) 1303 int optname; 1304 struct ip_moptions **imop; 1305 struct mbuf *m; 1306 { 1307 int error = 0; 1308 u_char loop; 1309 int i; 1310 struct in_addr addr; 1311 struct ip_mreq *mreq; 1312 struct ifnet *ifp; 1313 struct ip_moptions *imo = *imop; 1314 struct route ro; 1315 struct sockaddr_in *dst; 1316 int ifindex; 1317 1318 if (imo == NULL) { 1319 /* 1320 * No multicast option buffer attached to the pcb; 1321 * allocate one and initialize to default values. 1322 */ 1323 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1324 M_WAITOK); 1325 1326 if (imo == NULL) 1327 return (ENOBUFS); 1328 *imop = imo; 1329 imo->imo_multicast_ifp = NULL; 1330 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1331 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1332 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1333 imo->imo_num_memberships = 0; 1334 } 1335 1336 switch (optname) { 1337 1338 case IP_MULTICAST_IF: 1339 /* 1340 * Select the interface for outgoing multicast packets. 1341 */ 1342 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1343 error = EINVAL; 1344 break; 1345 } 1346 addr = *(mtod(m, struct in_addr *)); 1347 /* 1348 * INADDR_ANY is used to remove a previous selection. 1349 * When no interface is selected, a default one is 1350 * chosen every time a multicast packet is sent. 1351 */ 1352 if (in_nullhost(addr)) { 1353 imo->imo_multicast_ifp = NULL; 1354 break; 1355 } 1356 /* 1357 * The selected interface is identified by its local 1358 * IP address. Find the interface and confirm that 1359 * it supports multicasting. 1360 */ 1361 ifp = ip_multicast_if(&addr, &ifindex); 1362 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1363 error = EADDRNOTAVAIL; 1364 break; 1365 } 1366 imo->imo_multicast_ifp = ifp; 1367 if (ifindex) 1368 imo->imo_multicast_addr = addr; 1369 else 1370 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1371 break; 1372 1373 case IP_MULTICAST_TTL: 1374 /* 1375 * Set the IP time-to-live for outgoing multicast packets. 1376 */ 1377 if (m == NULL || m->m_len != 1) { 1378 error = EINVAL; 1379 break; 1380 } 1381 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1382 break; 1383 1384 case IP_MULTICAST_LOOP: 1385 /* 1386 * Set the loopback flag for outgoing multicast packets. 1387 * Must be zero or one. 1388 */ 1389 if (m == NULL || m->m_len != 1 || 1390 (loop = *(mtod(m, u_char *))) > 1) { 1391 error = EINVAL; 1392 break; 1393 } 1394 imo->imo_multicast_loop = loop; 1395 break; 1396 1397 case IP_ADD_MEMBERSHIP: 1398 /* 1399 * Add a multicast group membership. 1400 * Group must be a valid IP multicast address. 1401 */ 1402 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1403 error = EINVAL; 1404 break; 1405 } 1406 mreq = mtod(m, struct ip_mreq *); 1407 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1408 error = EINVAL; 1409 break; 1410 } 1411 /* 1412 * If no interface address was provided, use the interface of 1413 * the route to the given multicast address. 1414 */ 1415 if (in_nullhost(mreq->imr_interface)) { 1416 bzero((caddr_t)&ro, sizeof(ro)); 1417 ro.ro_rt = NULL; 1418 dst = satosin(&ro.ro_dst); 1419 dst->sin_len = sizeof(*dst); 1420 dst->sin_family = AF_INET; 1421 dst->sin_addr = mreq->imr_multiaddr; 1422 rtalloc(&ro); 1423 if (ro.ro_rt == NULL) { 1424 error = EADDRNOTAVAIL; 1425 break; 1426 } 1427 ifp = ro.ro_rt->rt_ifp; 1428 rtfree(ro.ro_rt); 1429 } else { 1430 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1431 } 1432 /* 1433 * See if we found an interface, and confirm that it 1434 * supports multicast. 1435 */ 1436 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1437 error = EADDRNOTAVAIL; 1438 break; 1439 } 1440 /* 1441 * See if the membership already exists or if all the 1442 * membership slots are full. 1443 */ 1444 for (i = 0; i < imo->imo_num_memberships; ++i) { 1445 if (imo->imo_membership[i]->inm_ifp == ifp && 1446 in_hosteq(imo->imo_membership[i]->inm_addr, 1447 mreq->imr_multiaddr)) 1448 break; 1449 } 1450 if (i < imo->imo_num_memberships) { 1451 error = EADDRINUSE; 1452 break; 1453 } 1454 if (i == IP_MAX_MEMBERSHIPS) { 1455 error = ETOOMANYREFS; 1456 break; 1457 } 1458 /* 1459 * Everything looks good; add a new record to the multicast 1460 * address list for the given interface. 1461 */ 1462 if ((imo->imo_membership[i] = 1463 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1464 error = ENOBUFS; 1465 break; 1466 } 1467 ++imo->imo_num_memberships; 1468 break; 1469 1470 case IP_DROP_MEMBERSHIP: 1471 /* 1472 * Drop a multicast group membership. 1473 * Group must be a valid IP multicast address. 1474 */ 1475 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1476 error = EINVAL; 1477 break; 1478 } 1479 mreq = mtod(m, struct ip_mreq *); 1480 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1481 error = EINVAL; 1482 break; 1483 } 1484 /* 1485 * If an interface address was specified, get a pointer 1486 * to its ifnet structure. 1487 */ 1488 if (in_nullhost(mreq->imr_interface)) 1489 ifp = NULL; 1490 else { 1491 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1492 if (ifp == NULL) { 1493 error = EADDRNOTAVAIL; 1494 break; 1495 } 1496 } 1497 /* 1498 * Find the membership in the membership array. 1499 */ 1500 for (i = 0; i < imo->imo_num_memberships; ++i) { 1501 if ((ifp == NULL || 1502 imo->imo_membership[i]->inm_ifp == ifp) && 1503 in_hosteq(imo->imo_membership[i]->inm_addr, 1504 mreq->imr_multiaddr)) 1505 break; 1506 } 1507 if (i == imo->imo_num_memberships) { 1508 error = EADDRNOTAVAIL; 1509 break; 1510 } 1511 /* 1512 * Give up the multicast address record to which the 1513 * membership points. 1514 */ 1515 in_delmulti(imo->imo_membership[i]); 1516 /* 1517 * Remove the gap in the membership array. 1518 */ 1519 for (++i; i < imo->imo_num_memberships; ++i) 1520 imo->imo_membership[i-1] = imo->imo_membership[i]; 1521 --imo->imo_num_memberships; 1522 break; 1523 1524 default: 1525 error = EOPNOTSUPP; 1526 break; 1527 } 1528 1529 /* 1530 * If all options have default values, no need to keep the mbuf. 1531 */ 1532 if (imo->imo_multicast_ifp == NULL && 1533 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1534 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1535 imo->imo_num_memberships == 0) { 1536 free(*imop, M_IPMOPTS); 1537 *imop = NULL; 1538 } 1539 1540 return (error); 1541 } 1542 1543 /* 1544 * Return the IP multicast options in response to user getsockopt(). 1545 */ 1546 int 1547 ip_getmoptions(optname, imo, mp) 1548 int optname; 1549 struct ip_moptions *imo; 1550 struct mbuf **mp; 1551 { 1552 u_char *ttl; 1553 u_char *loop; 1554 struct in_addr *addr; 1555 struct in_ifaddr *ia; 1556 1557 *mp = m_get(M_WAIT, MT_SOOPTS); 1558 1559 switch (optname) { 1560 1561 case IP_MULTICAST_IF: 1562 addr = mtod(*mp, struct in_addr *); 1563 (*mp)->m_len = sizeof(struct in_addr); 1564 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1565 *addr = zeroin_addr; 1566 else if (imo->imo_multicast_addr.s_addr) { 1567 /* return the value user has set */ 1568 *addr = imo->imo_multicast_addr; 1569 } else { 1570 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1571 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1572 } 1573 return (0); 1574 1575 case IP_MULTICAST_TTL: 1576 ttl = mtod(*mp, u_char *); 1577 (*mp)->m_len = 1; 1578 *ttl = imo ? imo->imo_multicast_ttl 1579 : IP_DEFAULT_MULTICAST_TTL; 1580 return (0); 1581 1582 case IP_MULTICAST_LOOP: 1583 loop = mtod(*mp, u_char *); 1584 (*mp)->m_len = 1; 1585 *loop = imo ? imo->imo_multicast_loop 1586 : IP_DEFAULT_MULTICAST_LOOP; 1587 return (0); 1588 1589 default: 1590 return (EOPNOTSUPP); 1591 } 1592 } 1593 1594 /* 1595 * Discard the IP multicast options. 1596 */ 1597 void 1598 ip_freemoptions(imo) 1599 struct ip_moptions *imo; 1600 { 1601 int i; 1602 1603 if (imo != NULL) { 1604 for (i = 0; i < imo->imo_num_memberships; ++i) 1605 in_delmulti(imo->imo_membership[i]); 1606 free(imo, M_IPMOPTS); 1607 } 1608 } 1609 1610 /* 1611 * Routine called from ip_output() to loop back a copy of an IP multicast 1612 * packet to the input queue of a specified interface. Note that this 1613 * calls the output routine of the loopback "driver", but with an interface 1614 * pointer that might NOT be &loif -- easier than replicating that code here. 1615 */ 1616 static void 1617 ip_mloopback(ifp, m, dst) 1618 struct ifnet *ifp; 1619 struct mbuf *m; 1620 struct sockaddr_in *dst; 1621 { 1622 struct ip *ip; 1623 struct mbuf *copym; 1624 1625 copym = m_copy(m, 0, M_COPYALL); 1626 if (copym != NULL 1627 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1628 copym = m_pullup(copym, sizeof(struct ip)); 1629 if (copym != NULL) { 1630 /* 1631 * We don't bother to fragment if the IP length is greater 1632 * than the interface's MTU. Can this possibly matter? 1633 */ 1634 ip = mtod(copym, struct ip *); 1635 HTONS(ip->ip_len); 1636 HTONS(ip->ip_off); 1637 ip->ip_sum = 0; 1638 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1639 (void) looutput(ifp, copym, sintosa(dst), NULL); 1640 } 1641 } 1642