1 /* $NetBSD: ip_output.c,v 1.79 2000/11/11 00:55:51 thorpej 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 "opt_pfil_hooks.h" 105 #include "opt_ipsec.h" 106 #include "opt_mrouting.h" 107 108 #include <sys/param.h> 109 #include <sys/malloc.h> 110 #include <sys/mbuf.h> 111 #include <sys/errno.h> 112 #include <sys/protosw.h> 113 #include <sys/socket.h> 114 #include <sys/socketvar.h> 115 #include <sys/systm.h> 116 #include <sys/proc.h> 117 118 #include <net/if.h> 119 #include <net/route.h> 120 #include <net/pfil.h> 121 122 #include <netinet/in.h> 123 #include <netinet/in_systm.h> 124 #include <netinet/ip.h> 125 #include <netinet/in_pcb.h> 126 #include <netinet/in_var.h> 127 #include <netinet/ip_var.h> 128 129 #ifdef MROUTING 130 #include <netinet/ip_mroute.h> 131 #endif 132 133 #ifdef __vax__ 134 #include <machine/mtpr.h> 135 #endif 136 137 #include <machine/stdarg.h> 138 139 #ifdef IPSEC 140 #include <netinet6/ipsec.h> 141 #include <netkey/key.h> 142 #include <netkey/key_debug.h> 143 #endif /*IPSEC*/ 144 145 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, 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; 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 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 &= IP_DF; 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 PFIL_HOOKS 433 /* 434 * Run through list of hooks for output packets. 435 */ 436 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 437 PFIL_OUT)) != 0) 438 goto done; 439 if (m == NULL) 440 goto done; 441 442 ip = mtod(m, struct ip *); 443 #endif /* PFIL_HOOKS */ 444 445 #ifdef IPSEC 446 /* get SP for this packet */ 447 if (so == NULL) 448 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 449 else 450 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 451 452 if (sp == NULL) { 453 ipsecstat.out_inval++; 454 goto bad; 455 } 456 457 error = 0; 458 459 /* check policy */ 460 switch (sp->policy) { 461 case IPSEC_POLICY_DISCARD: 462 /* 463 * This packet is just discarded. 464 */ 465 ipsecstat.out_polvio++; 466 goto bad; 467 468 case IPSEC_POLICY_BYPASS: 469 case IPSEC_POLICY_NONE: 470 /* no need to do IPsec. */ 471 goto skip_ipsec; 472 473 case IPSEC_POLICY_IPSEC: 474 if (sp->req == NULL) { 475 /* XXX should be panic ? */ 476 printf("ip_output: No IPsec request specified.\n"); 477 error = EINVAL; 478 goto bad; 479 } 480 break; 481 482 case IPSEC_POLICY_ENTRUST: 483 default: 484 printf("ip_output: Invalid policy found. %d\n", sp->policy); 485 } 486 487 /* 488 * ipsec4_output() expects ip_len and ip_off in network 489 * order. They have been set to network order above. 490 */ 491 492 { 493 struct ipsec_output_state state; 494 bzero(&state, sizeof(state)); 495 state.m = m; 496 if (flags & IP_ROUTETOIF) { 497 state.ro = &iproute; 498 bzero(&iproute, sizeof(iproute)); 499 } else 500 state.ro = ro; 501 state.dst = (struct sockaddr *)dst; 502 503 error = ipsec4_output(&state, sp, flags); 504 505 m = state.m; 506 if (flags & IP_ROUTETOIF) { 507 /* 508 * if we have tunnel mode SA, we may need to ignore 509 * IP_ROUTETOIF. 510 */ 511 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 512 flags &= ~IP_ROUTETOIF; 513 ro = state.ro; 514 } 515 } else 516 ro = state.ro; 517 dst = (struct sockaddr_in *)state.dst; 518 if (error) { 519 /* mbuf is already reclaimed in ipsec4_output. */ 520 m0 = NULL; 521 switch (error) { 522 case EHOSTUNREACH: 523 case ENETUNREACH: 524 case EMSGSIZE: 525 case ENOBUFS: 526 case ENOMEM: 527 break; 528 default: 529 printf("ip4_output (ipsec): error code %d\n", error); 530 /*fall through*/ 531 case ENOENT: 532 /* don't show these error codes to the user */ 533 error = 0; 534 break; 535 } 536 goto bad; 537 } 538 } 539 540 /* be sure to update variables that are affected by ipsec4_output() */ 541 ip = mtod(m, struct ip *); 542 #ifdef _IP_VHL 543 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 544 #else 545 hlen = ip->ip_hl << 2; 546 #endif 547 ip_len = ntohs(ip->ip_len); 548 549 if (ro->ro_rt == NULL) { 550 if ((flags & IP_ROUTETOIF) == 0) { 551 printf("ip_output: " 552 "can't update route after IPsec processing\n"); 553 error = EHOSTUNREACH; /*XXX*/ 554 goto bad; 555 } 556 } else { 557 /* nobody uses ia beyond here */ 558 ifp = ro->ro_rt->rt_ifp; 559 } 560 561 skip_ipsec: 562 #endif /*IPSEC*/ 563 564 /* 565 * If small enough for mtu of path, can just send directly. 566 */ 567 if (ip_len <= mtu) { 568 #if IFA_STATS 569 /* 570 * search for the source address structure to 571 * maintain output statistics. 572 */ 573 INADDR_TO_IA(ip->ip_src, ia); 574 if (ia) 575 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 576 #endif 577 ip->ip_sum = 0; 578 ip->ip_sum = in_cksum(m, hlen); 579 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 580 goto done; 581 } 582 583 /* 584 * Too large for interface; fragment if possible. 585 * Must be able to put at least 8 bytes per fragment. 586 * 587 * Note we swap ip_len and ip_off into host order to make 588 * the logic below a little simpler. 589 */ 590 591 NTOHS(ip->ip_len); 592 NTOHS(ip->ip_off); 593 594 #if 0 595 /* 596 * If IPsec packet is too big for the interface, try fragment it. 597 * XXX This really is a quickhack. May be inappropriate. 598 * XXX fails if somebody is sending AH'ed packet, with: 599 * sizeof(packet without AH) < mtu < sizeof(packet with AH) 600 */ 601 if (sab && ip->ip_p != IPPROTO_AH && (flags & IP_FORWARDING) == 0) 602 ip->ip_off &= ~IP_DF; 603 #endif /*IPSEC*/ 604 if (ip->ip_off & IP_DF) { 605 if (flags & IP_RETURNMTU) 606 *mtu_p = mtu; 607 error = EMSGSIZE; 608 ipstat.ips_cantfrag++; 609 goto bad; 610 } 611 len = (mtu - hlen) &~ 7; 612 if (len < 8) { 613 error = EMSGSIZE; 614 goto bad; 615 } 616 617 { 618 int mhlen, firstlen = len; 619 struct mbuf **mnext = &m->m_nextpkt; 620 int fragments = 0; 621 int s; 622 623 /* 624 * Loop through length of segment after first fragment, 625 * make new header and copy data of each part and link onto chain. 626 */ 627 m0 = m; 628 mhlen = sizeof (struct ip); 629 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 630 MGETHDR(m, M_DONTWAIT, MT_HEADER); 631 if (m == 0) { 632 error = ENOBUFS; 633 ipstat.ips_odropped++; 634 goto sendorfree; 635 } 636 *mnext = m; 637 mnext = &m->m_nextpkt; 638 m->m_data += max_linkhdr; 639 mhip = mtod(m, struct ip *); 640 *mhip = *ip; 641 /* we must inherit MCAST and BCAST flags */ 642 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 643 if (hlen > sizeof (struct ip)) { 644 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 645 mhip->ip_hl = mhlen >> 2; 646 } 647 m->m_len = mhlen; 648 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 649 if (ip->ip_off & IP_MF) 650 mhip->ip_off |= IP_MF; 651 if (off + len >= (u_int16_t)ip->ip_len) 652 len = (u_int16_t)ip->ip_len - off; 653 else 654 mhip->ip_off |= IP_MF; 655 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 656 m->m_next = m_copy(m0, off, len); 657 if (m->m_next == 0) { 658 error = ENOBUFS; /* ??? */ 659 ipstat.ips_odropped++; 660 goto sendorfree; 661 } 662 m->m_pkthdr.len = mhlen + len; 663 m->m_pkthdr.rcvif = (struct ifnet *)0; 664 HTONS(mhip->ip_off); 665 mhip->ip_sum = 0; 666 mhip->ip_sum = in_cksum(m, mhlen); 667 ipstat.ips_ofragments++; 668 fragments++; 669 } 670 /* 671 * Update first fragment by trimming what's been copied out 672 * and updating header, then send each fragment (in order). 673 */ 674 m = m0; 675 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 676 m->m_pkthdr.len = hlen + firstlen; 677 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 678 ip->ip_off |= IP_MF; 679 HTONS(ip->ip_off); 680 ip->ip_sum = 0; 681 ip->ip_sum = in_cksum(m, hlen); 682 sendorfree: 683 /* 684 * If there is no room for all the fragments, don't queue 685 * any of them. 686 */ 687 s = splimp(); 688 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 689 error = ENOBUFS; 690 splx(s); 691 for (m = m0; m; m = m0) { 692 m0 = m->m_nextpkt; 693 m->m_nextpkt = 0; 694 if (error == 0) { 695 #if IFA_STATS 696 /* 697 * search for the source address structure to 698 * maintain output statistics. 699 */ 700 INADDR_TO_IA(ip->ip_src, ia); 701 if (ia) { 702 ia->ia_ifa.ifa_data.ifad_outbytes += 703 ntohs(ip->ip_len); 704 } 705 #endif 706 error = (*ifp->if_output)(ifp, m, sintosa(dst), 707 ro->ro_rt); 708 } else 709 m_freem(m); 710 } 711 712 if (error == 0) 713 ipstat.ips_fragmented++; 714 } 715 done: 716 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 717 RTFREE(ro->ro_rt); 718 ro->ro_rt = 0; 719 } 720 721 #ifdef IPSEC 722 if (sp != NULL) { 723 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 724 printf("DP ip_output call free SP:%p\n", sp)); 725 key_freesp(sp); 726 } 727 #endif /* IPSEC */ 728 729 return (error); 730 bad: 731 m_freem(m); 732 goto done; 733 } 734 735 /* 736 * Determine the maximum length of the options to be inserted; 737 * we would far rather allocate too much space rather than too little. 738 */ 739 740 u_int 741 ip_optlen(inp) 742 struct inpcb *inp; 743 { 744 struct mbuf *m = inp->inp_options; 745 746 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 747 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 748 else 749 return 0; 750 } 751 752 753 /* 754 * Insert IP options into preformed packet. 755 * Adjust IP destination as required for IP source routing, 756 * as indicated by a non-zero in_addr at the start of the options. 757 */ 758 static struct mbuf * 759 ip_insertoptions(m, opt, phlen) 760 struct mbuf *m; 761 struct mbuf *opt; 762 int *phlen; 763 { 764 struct ipoption *p = mtod(opt, struct ipoption *); 765 struct mbuf *n; 766 struct ip *ip = mtod(m, struct ip *); 767 unsigned optlen; 768 769 optlen = opt->m_len - sizeof(p->ipopt_dst); 770 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 771 return (m); /* XXX should fail */ 772 if (!in_nullhost(p->ipopt_dst)) 773 ip->ip_dst = p->ipopt_dst; 774 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 775 MGETHDR(n, M_DONTWAIT, MT_HEADER); 776 if (n == 0) 777 return (m); 778 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 779 m->m_len -= sizeof(struct ip); 780 m->m_data += sizeof(struct ip); 781 n->m_next = m; 782 m = n; 783 m->m_len = optlen + sizeof(struct ip); 784 m->m_data += max_linkhdr; 785 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 786 } else { 787 m->m_data -= optlen; 788 m->m_len += optlen; 789 m->m_pkthdr.len += optlen; 790 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 791 } 792 ip = mtod(m, struct ip *); 793 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 794 *phlen = sizeof(struct ip) + optlen; 795 ip->ip_len += optlen; 796 return (m); 797 } 798 799 /* 800 * Copy options from ip to jp, 801 * omitting those not copied during fragmentation. 802 */ 803 int 804 ip_optcopy(ip, jp) 805 struct ip *ip, *jp; 806 { 807 u_char *cp, *dp; 808 int opt, optlen, cnt; 809 810 cp = (u_char *)(ip + 1); 811 dp = (u_char *)(jp + 1); 812 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 813 for (; cnt > 0; cnt -= optlen, cp += optlen) { 814 opt = cp[0]; 815 if (opt == IPOPT_EOL) 816 break; 817 if (opt == IPOPT_NOP) { 818 /* Preserve for IP mcast tunnel's LSRR alignment. */ 819 *dp++ = IPOPT_NOP; 820 optlen = 1; 821 continue; 822 } 823 #ifdef DIAGNOSTIC 824 if (cnt < IPOPT_OLEN + sizeof(*cp)) 825 panic("malformed IPv4 option passed to ip_optcopy"); 826 #endif 827 optlen = cp[IPOPT_OLEN]; 828 #ifdef DIAGNOSTIC 829 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 830 panic("malformed IPv4 option passed to ip_optcopy"); 831 #endif 832 /* bogus lengths should have been caught by ip_dooptions */ 833 if (optlen > cnt) 834 optlen = cnt; 835 if (IPOPT_COPIED(opt)) { 836 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 837 dp += optlen; 838 } 839 } 840 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 841 *dp++ = IPOPT_EOL; 842 return (optlen); 843 } 844 845 /* 846 * IP socket option processing. 847 */ 848 int 849 ip_ctloutput(op, so, level, optname, mp) 850 int op; 851 struct socket *so; 852 int level, optname; 853 struct mbuf **mp; 854 { 855 struct inpcb *inp = sotoinpcb(so); 856 struct mbuf *m = *mp; 857 int optval = 0; 858 int error = 0; 859 #ifdef IPSEC 860 #ifdef __NetBSD__ 861 struct proc *p = curproc; /*XXX*/ 862 #endif 863 #endif 864 865 if (level != IPPROTO_IP) { 866 error = EINVAL; 867 if (op == PRCO_SETOPT && *mp) 868 (void) m_free(*mp); 869 } else switch (op) { 870 871 case PRCO_SETOPT: 872 switch (optname) { 873 case IP_OPTIONS: 874 #ifdef notyet 875 case IP_RETOPTS: 876 return (ip_pcbopts(optname, &inp->inp_options, m)); 877 #else 878 return (ip_pcbopts(&inp->inp_options, m)); 879 #endif 880 881 case IP_TOS: 882 case IP_TTL: 883 case IP_RECVOPTS: 884 case IP_RECVRETOPTS: 885 case IP_RECVDSTADDR: 886 case IP_RECVIF: 887 if (m == NULL || m->m_len != sizeof(int)) 888 error = EINVAL; 889 else { 890 optval = *mtod(m, int *); 891 switch (optname) { 892 893 case IP_TOS: 894 inp->inp_ip.ip_tos = optval; 895 break; 896 897 case IP_TTL: 898 inp->inp_ip.ip_ttl = optval; 899 break; 900 #define OPTSET(bit) \ 901 if (optval) \ 902 inp->inp_flags |= bit; \ 903 else \ 904 inp->inp_flags &= ~bit; 905 906 case IP_RECVOPTS: 907 OPTSET(INP_RECVOPTS); 908 break; 909 910 case IP_RECVRETOPTS: 911 OPTSET(INP_RECVRETOPTS); 912 break; 913 914 case IP_RECVDSTADDR: 915 OPTSET(INP_RECVDSTADDR); 916 break; 917 918 case IP_RECVIF: 919 OPTSET(INP_RECVIF); 920 break; 921 } 922 } 923 break; 924 #undef OPTSET 925 926 case IP_MULTICAST_IF: 927 case IP_MULTICAST_TTL: 928 case IP_MULTICAST_LOOP: 929 case IP_ADD_MEMBERSHIP: 930 case IP_DROP_MEMBERSHIP: 931 error = ip_setmoptions(optname, &inp->inp_moptions, m); 932 break; 933 934 case IP_PORTRANGE: 935 if (m == 0 || m->m_len != sizeof(int)) 936 error = EINVAL; 937 else { 938 optval = *mtod(m, int *); 939 940 switch (optval) { 941 942 case IP_PORTRANGE_DEFAULT: 943 case IP_PORTRANGE_HIGH: 944 inp->inp_flags &= ~(INP_LOWPORT); 945 break; 946 947 case IP_PORTRANGE_LOW: 948 inp->inp_flags |= INP_LOWPORT; 949 break; 950 951 default: 952 error = EINVAL; 953 break; 954 } 955 } 956 break; 957 958 #ifdef IPSEC 959 case IP_IPSEC_POLICY: 960 { 961 caddr_t req = NULL; 962 size_t len = 0; 963 int priv = 0; 964 965 #ifdef __NetBSD__ 966 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 967 priv = 0; 968 else 969 priv = 1; 970 #else 971 priv = (in6p->in6p_socket->so_state & SS_PRIV); 972 #endif 973 if (m) { 974 req = mtod(m, caddr_t); 975 len = m->m_len; 976 } 977 error = ipsec4_set_policy(inp, optname, req, len, priv); 978 break; 979 } 980 #endif /*IPSEC*/ 981 982 default: 983 error = ENOPROTOOPT; 984 break; 985 } 986 if (m) 987 (void)m_free(m); 988 break; 989 990 case PRCO_GETOPT: 991 switch (optname) { 992 case IP_OPTIONS: 993 case IP_RETOPTS: 994 *mp = m = m_get(M_WAIT, MT_SOOPTS); 995 if (inp->inp_options) { 996 m->m_len = inp->inp_options->m_len; 997 bcopy(mtod(inp->inp_options, caddr_t), 998 mtod(m, caddr_t), (unsigned)m->m_len); 999 } else 1000 m->m_len = 0; 1001 break; 1002 1003 case IP_TOS: 1004 case IP_TTL: 1005 case IP_RECVOPTS: 1006 case IP_RECVRETOPTS: 1007 case IP_RECVDSTADDR: 1008 case IP_RECVIF: 1009 case IP_ERRORMTU: 1010 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1011 m->m_len = sizeof(int); 1012 switch (optname) { 1013 1014 case IP_TOS: 1015 optval = inp->inp_ip.ip_tos; 1016 break; 1017 1018 case IP_TTL: 1019 optval = inp->inp_ip.ip_ttl; 1020 break; 1021 1022 case IP_ERRORMTU: 1023 optval = inp->inp_errormtu; 1024 break; 1025 1026 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1027 1028 case IP_RECVOPTS: 1029 optval = OPTBIT(INP_RECVOPTS); 1030 break; 1031 1032 case IP_RECVRETOPTS: 1033 optval = OPTBIT(INP_RECVRETOPTS); 1034 break; 1035 1036 case IP_RECVDSTADDR: 1037 optval = OPTBIT(INP_RECVDSTADDR); 1038 break; 1039 1040 case IP_RECVIF: 1041 optval = OPTBIT(INP_RECVIF); 1042 break; 1043 } 1044 *mtod(m, int *) = optval; 1045 break; 1046 1047 #ifdef IPSEC 1048 case IP_IPSEC_POLICY: 1049 { 1050 caddr_t req = NULL; 1051 size_t len; 1052 1053 if (m) { 1054 req = mtod(m, caddr_t); 1055 len = m->m_len; 1056 } 1057 error = ipsec4_get_policy(inp, req, len, mp); 1058 break; 1059 } 1060 #endif /*IPSEC*/ 1061 1062 case IP_MULTICAST_IF: 1063 case IP_MULTICAST_TTL: 1064 case IP_MULTICAST_LOOP: 1065 case IP_ADD_MEMBERSHIP: 1066 case IP_DROP_MEMBERSHIP: 1067 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1068 break; 1069 1070 case IP_PORTRANGE: 1071 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1072 m->m_len = sizeof(int); 1073 1074 if (inp->inp_flags & INP_LOWPORT) 1075 optval = IP_PORTRANGE_LOW; 1076 else 1077 optval = IP_PORTRANGE_DEFAULT; 1078 1079 *mtod(m, int *) = optval; 1080 break; 1081 1082 default: 1083 error = ENOPROTOOPT; 1084 break; 1085 } 1086 break; 1087 } 1088 return (error); 1089 } 1090 1091 /* 1092 * Set up IP options in pcb for insertion in output packets. 1093 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1094 * with destination address if source routed. 1095 */ 1096 int 1097 #ifdef notyet 1098 ip_pcbopts(optname, pcbopt, m) 1099 int optname; 1100 #else 1101 ip_pcbopts(pcbopt, m) 1102 #endif 1103 struct mbuf **pcbopt; 1104 struct mbuf *m; 1105 { 1106 int cnt, optlen; 1107 u_char *cp; 1108 u_char opt; 1109 1110 /* turn off any old options */ 1111 if (*pcbopt) 1112 (void)m_free(*pcbopt); 1113 *pcbopt = 0; 1114 if (m == (struct mbuf *)0 || m->m_len == 0) { 1115 /* 1116 * Only turning off any previous options. 1117 */ 1118 if (m) 1119 (void)m_free(m); 1120 return (0); 1121 } 1122 1123 #ifndef vax 1124 if (m->m_len % sizeof(int32_t)) 1125 goto bad; 1126 #endif 1127 /* 1128 * IP first-hop destination address will be stored before 1129 * actual options; move other options back 1130 * and clear it when none present. 1131 */ 1132 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1133 goto bad; 1134 cnt = m->m_len; 1135 m->m_len += sizeof(struct in_addr); 1136 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1137 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1138 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1139 1140 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1141 opt = cp[IPOPT_OPTVAL]; 1142 if (opt == IPOPT_EOL) 1143 break; 1144 if (opt == IPOPT_NOP) 1145 optlen = 1; 1146 else { 1147 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1148 goto bad; 1149 optlen = cp[IPOPT_OLEN]; 1150 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1151 goto bad; 1152 } 1153 switch (opt) { 1154 1155 default: 1156 break; 1157 1158 case IPOPT_LSRR: 1159 case IPOPT_SSRR: 1160 /* 1161 * user process specifies route as: 1162 * ->A->B->C->D 1163 * D must be our final destination (but we can't 1164 * check that since we may not have connected yet). 1165 * A is first hop destination, which doesn't appear in 1166 * actual IP option, but is stored before the options. 1167 */ 1168 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1169 goto bad; 1170 m->m_len -= sizeof(struct in_addr); 1171 cnt -= sizeof(struct in_addr); 1172 optlen -= sizeof(struct in_addr); 1173 cp[IPOPT_OLEN] = optlen; 1174 /* 1175 * Move first hop before start of options. 1176 */ 1177 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1178 sizeof(struct in_addr)); 1179 /* 1180 * Then copy rest of options back 1181 * to close up the deleted entry. 1182 */ 1183 memmove(&cp[IPOPT_OFFSET+1], 1184 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1185 (unsigned)cnt + sizeof(struct in_addr)); 1186 break; 1187 } 1188 } 1189 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1190 goto bad; 1191 *pcbopt = m; 1192 return (0); 1193 1194 bad: 1195 (void)m_free(m); 1196 return (EINVAL); 1197 } 1198 1199 /* 1200 * Set the IP multicast options in response to user setsockopt(). 1201 */ 1202 int 1203 ip_setmoptions(optname, imop, m) 1204 int optname; 1205 struct ip_moptions **imop; 1206 struct mbuf *m; 1207 { 1208 int error = 0; 1209 u_char loop; 1210 int i; 1211 struct in_addr addr; 1212 struct ip_mreq *mreq; 1213 struct ifnet *ifp; 1214 struct ip_moptions *imo = *imop; 1215 struct route ro; 1216 struct sockaddr_in *dst; 1217 1218 if (imo == NULL) { 1219 /* 1220 * No multicast option buffer attached to the pcb; 1221 * allocate one and initialize to default values. 1222 */ 1223 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1224 M_WAITOK); 1225 1226 if (imo == NULL) 1227 return (ENOBUFS); 1228 *imop = imo; 1229 imo->imo_multicast_ifp = NULL; 1230 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1231 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1232 imo->imo_num_memberships = 0; 1233 } 1234 1235 switch (optname) { 1236 1237 case IP_MULTICAST_IF: 1238 /* 1239 * Select the interface for outgoing multicast packets. 1240 */ 1241 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1242 error = EINVAL; 1243 break; 1244 } 1245 addr = *(mtod(m, struct in_addr *)); 1246 /* 1247 * INADDR_ANY is used to remove a previous selection. 1248 * When no interface is selected, a default one is 1249 * chosen every time a multicast packet is sent. 1250 */ 1251 if (in_nullhost(addr)) { 1252 imo->imo_multicast_ifp = NULL; 1253 break; 1254 } 1255 /* 1256 * The selected interface is identified by its local 1257 * IP address. Find the interface and confirm that 1258 * it supports multicasting. 1259 */ 1260 INADDR_TO_IFP(addr, ifp); 1261 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1262 error = EADDRNOTAVAIL; 1263 break; 1264 } 1265 imo->imo_multicast_ifp = ifp; 1266 break; 1267 1268 case IP_MULTICAST_TTL: 1269 /* 1270 * Set the IP time-to-live for outgoing multicast packets. 1271 */ 1272 if (m == NULL || m->m_len != 1) { 1273 error = EINVAL; 1274 break; 1275 } 1276 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1277 break; 1278 1279 case IP_MULTICAST_LOOP: 1280 /* 1281 * Set the loopback flag for outgoing multicast packets. 1282 * Must be zero or one. 1283 */ 1284 if (m == NULL || m->m_len != 1 || 1285 (loop = *(mtod(m, u_char *))) > 1) { 1286 error = EINVAL; 1287 break; 1288 } 1289 imo->imo_multicast_loop = loop; 1290 break; 1291 1292 case IP_ADD_MEMBERSHIP: 1293 /* 1294 * Add a multicast group membership. 1295 * Group must be a valid IP multicast address. 1296 */ 1297 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1298 error = EINVAL; 1299 break; 1300 } 1301 mreq = mtod(m, struct ip_mreq *); 1302 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1303 error = EINVAL; 1304 break; 1305 } 1306 /* 1307 * If no interface address was provided, use the interface of 1308 * the route to the given multicast address. 1309 */ 1310 if (in_nullhost(mreq->imr_interface)) { 1311 bzero((caddr_t)&ro, sizeof(ro)); 1312 ro.ro_rt = NULL; 1313 dst = satosin(&ro.ro_dst); 1314 dst->sin_len = sizeof(*dst); 1315 dst->sin_family = AF_INET; 1316 dst->sin_addr = mreq->imr_multiaddr; 1317 rtalloc(&ro); 1318 if (ro.ro_rt == NULL) { 1319 error = EADDRNOTAVAIL; 1320 break; 1321 } 1322 ifp = ro.ro_rt->rt_ifp; 1323 rtfree(ro.ro_rt); 1324 } else { 1325 INADDR_TO_IFP(mreq->imr_interface, ifp); 1326 } 1327 /* 1328 * See if we found an interface, and confirm that it 1329 * supports multicast. 1330 */ 1331 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1332 error = EADDRNOTAVAIL; 1333 break; 1334 } 1335 /* 1336 * See if the membership already exists or if all the 1337 * membership slots are full. 1338 */ 1339 for (i = 0; i < imo->imo_num_memberships; ++i) { 1340 if (imo->imo_membership[i]->inm_ifp == ifp && 1341 in_hosteq(imo->imo_membership[i]->inm_addr, 1342 mreq->imr_multiaddr)) 1343 break; 1344 } 1345 if (i < imo->imo_num_memberships) { 1346 error = EADDRINUSE; 1347 break; 1348 } 1349 if (i == IP_MAX_MEMBERSHIPS) { 1350 error = ETOOMANYREFS; 1351 break; 1352 } 1353 /* 1354 * Everything looks good; add a new record to the multicast 1355 * address list for the given interface. 1356 */ 1357 if ((imo->imo_membership[i] = 1358 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1359 error = ENOBUFS; 1360 break; 1361 } 1362 ++imo->imo_num_memberships; 1363 break; 1364 1365 case IP_DROP_MEMBERSHIP: 1366 /* 1367 * Drop a multicast group membership. 1368 * Group must be a valid IP multicast address. 1369 */ 1370 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1371 error = EINVAL; 1372 break; 1373 } 1374 mreq = mtod(m, struct ip_mreq *); 1375 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1376 error = EINVAL; 1377 break; 1378 } 1379 /* 1380 * If an interface address was specified, get a pointer 1381 * to its ifnet structure. 1382 */ 1383 if (in_nullhost(mreq->imr_interface)) 1384 ifp = NULL; 1385 else { 1386 INADDR_TO_IFP(mreq->imr_interface, ifp); 1387 if (ifp == NULL) { 1388 error = EADDRNOTAVAIL; 1389 break; 1390 } 1391 } 1392 /* 1393 * Find the membership in the membership array. 1394 */ 1395 for (i = 0; i < imo->imo_num_memberships; ++i) { 1396 if ((ifp == NULL || 1397 imo->imo_membership[i]->inm_ifp == ifp) && 1398 in_hosteq(imo->imo_membership[i]->inm_addr, 1399 mreq->imr_multiaddr)) 1400 break; 1401 } 1402 if (i == imo->imo_num_memberships) { 1403 error = EADDRNOTAVAIL; 1404 break; 1405 } 1406 /* 1407 * Give up the multicast address record to which the 1408 * membership points. 1409 */ 1410 in_delmulti(imo->imo_membership[i]); 1411 /* 1412 * Remove the gap in the membership array. 1413 */ 1414 for (++i; i < imo->imo_num_memberships; ++i) 1415 imo->imo_membership[i-1] = imo->imo_membership[i]; 1416 --imo->imo_num_memberships; 1417 break; 1418 1419 default: 1420 error = EOPNOTSUPP; 1421 break; 1422 } 1423 1424 /* 1425 * If all options have default values, no need to keep the mbuf. 1426 */ 1427 if (imo->imo_multicast_ifp == NULL && 1428 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1429 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1430 imo->imo_num_memberships == 0) { 1431 free(*imop, M_IPMOPTS); 1432 *imop = NULL; 1433 } 1434 1435 return (error); 1436 } 1437 1438 /* 1439 * Return the IP multicast options in response to user getsockopt(). 1440 */ 1441 int 1442 ip_getmoptions(optname, imo, mp) 1443 int optname; 1444 struct ip_moptions *imo; 1445 struct mbuf **mp; 1446 { 1447 u_char *ttl; 1448 u_char *loop; 1449 struct in_addr *addr; 1450 struct in_ifaddr *ia; 1451 1452 *mp = m_get(M_WAIT, MT_SOOPTS); 1453 1454 switch (optname) { 1455 1456 case IP_MULTICAST_IF: 1457 addr = mtod(*mp, struct in_addr *); 1458 (*mp)->m_len = sizeof(struct in_addr); 1459 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1460 *addr = zeroin_addr; 1461 else { 1462 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1463 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1464 } 1465 return (0); 1466 1467 case IP_MULTICAST_TTL: 1468 ttl = mtod(*mp, u_char *); 1469 (*mp)->m_len = 1; 1470 *ttl = imo ? imo->imo_multicast_ttl 1471 : IP_DEFAULT_MULTICAST_TTL; 1472 return (0); 1473 1474 case IP_MULTICAST_LOOP: 1475 loop = mtod(*mp, u_char *); 1476 (*mp)->m_len = 1; 1477 *loop = imo ? imo->imo_multicast_loop 1478 : IP_DEFAULT_MULTICAST_LOOP; 1479 return (0); 1480 1481 default: 1482 return (EOPNOTSUPP); 1483 } 1484 } 1485 1486 /* 1487 * Discard the IP multicast options. 1488 */ 1489 void 1490 ip_freemoptions(imo) 1491 struct ip_moptions *imo; 1492 { 1493 int i; 1494 1495 if (imo != NULL) { 1496 for (i = 0; i < imo->imo_num_memberships; ++i) 1497 in_delmulti(imo->imo_membership[i]); 1498 free(imo, M_IPMOPTS); 1499 } 1500 } 1501 1502 /* 1503 * Routine called from ip_output() to loop back a copy of an IP multicast 1504 * packet to the input queue of a specified interface. Note that this 1505 * calls the output routine of the loopback "driver", but with an interface 1506 * pointer that might NOT be &loif -- easier than replicating that code here. 1507 */ 1508 static void 1509 ip_mloopback(ifp, m, dst) 1510 struct ifnet *ifp; 1511 struct mbuf *m; 1512 struct sockaddr_in *dst; 1513 { 1514 struct ip *ip; 1515 struct mbuf *copym; 1516 1517 copym = m_copy(m, 0, M_COPYALL); 1518 if (copym != NULL 1519 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1520 copym = m_pullup(copym, sizeof(struct ip)); 1521 if (copym != NULL) { 1522 /* 1523 * We don't bother to fragment if the IP length is greater 1524 * than the interface's MTU. Can this possibly matter? 1525 */ 1526 ip = mtod(copym, struct ip *); 1527 HTONS(ip->ip_len); 1528 HTONS(ip->ip_off); 1529 ip->ip_sum = 0; 1530 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1531 (void) looutput(ifp, copym, sintosa(dst), NULL); 1532 } 1533 } 1534