1 /* $NetBSD: ip_output.c,v 1.84 2001/04/13 23:30:24 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 struct ifnet *ip_multicast_if __P((struct in_addr *, int *)); 147 static void ip_mloopback 148 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); 149 150 #ifdef PFIL_HOOKS 151 extern struct pfil_head inet_pfil_hook; /* XXX */ 152 #endif 153 154 /* 155 * IP output. The packet in mbuf chain m contains a skeletal IP 156 * header (with len, off, ttl, proto, tos, src, dst). 157 * The mbuf chain containing the packet will be freed. 158 * The mbuf opt, if present, will not be freed. 159 */ 160 int 161 #if __STDC__ 162 ip_output(struct mbuf *m0, ...) 163 #else 164 ip_output(m0, va_alist) 165 struct mbuf *m0; 166 va_dcl 167 #endif 168 { 169 struct ip *ip, *mhip; 170 struct ifnet *ifp; 171 struct mbuf *m = m0; 172 int hlen = sizeof (struct ip); 173 int len, off, error = 0; 174 struct route iproute; 175 struct sockaddr_in *dst; 176 struct in_ifaddr *ia; 177 struct mbuf *opt; 178 struct route *ro; 179 int flags; 180 int *mtu_p; 181 int mtu; 182 struct ip_moptions *imo; 183 va_list ap; 184 #ifdef IPSEC 185 struct socket *so; 186 struct secpolicy *sp = NULL; 187 #endif /*IPSEC*/ 188 u_int16_t ip_len; 189 190 va_start(ap, m0); 191 opt = va_arg(ap, struct mbuf *); 192 ro = va_arg(ap, struct route *); 193 flags = va_arg(ap, int); 194 imo = va_arg(ap, struct ip_moptions *); 195 if (flags & IP_RETURNMTU) 196 mtu_p = va_arg(ap, int *); 197 else 198 mtu_p = NULL; 199 va_end(ap); 200 201 #ifdef IPSEC 202 so = ipsec_getsocket(m); 203 (void)ipsec_setsocket(m, NULL); 204 #endif /*IPSEC*/ 205 206 #ifdef DIAGNOSTIC 207 if ((m->m_flags & M_PKTHDR) == 0) 208 panic("ip_output no HDR"); 209 #endif 210 if (opt) { 211 m = ip_insertoptions(m, opt, &len); 212 hlen = len; 213 } 214 ip = mtod(m, struct ip *); 215 /* 216 * Fill in IP header. 217 */ 218 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 219 ip->ip_v = IPVERSION; 220 ip->ip_off &= IP_DF; 221 ip->ip_id = htons(ip_id++); 222 ip->ip_hl = hlen >> 2; 223 ipstat.ips_localout++; 224 } else { 225 hlen = ip->ip_hl << 2; 226 } 227 /* 228 * Route packet. 229 */ 230 if (ro == 0) { 231 ro = &iproute; 232 bzero((caddr_t)ro, sizeof (*ro)); 233 } 234 dst = satosin(&ro->ro_dst); 235 /* 236 * If there is a cached route, 237 * check that it is to the same destination 238 * and is still up. If not, free it and try again. 239 */ 240 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 241 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 242 RTFREE(ro->ro_rt); 243 ro->ro_rt = (struct rtentry *)0; 244 } 245 if (ro->ro_rt == 0) { 246 dst->sin_family = AF_INET; 247 dst->sin_len = sizeof(*dst); 248 dst->sin_addr = ip->ip_dst; 249 } 250 /* 251 * If routing to interface only, 252 * short circuit routing lookup. 253 */ 254 if (flags & IP_ROUTETOIF) { 255 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 256 ipstat.ips_noroute++; 257 error = ENETUNREACH; 258 goto bad; 259 } 260 ifp = ia->ia_ifp; 261 mtu = ifp->if_mtu; 262 ip->ip_ttl = 1; 263 } else { 264 if (ro->ro_rt == 0) 265 rtalloc(ro); 266 if (ro->ro_rt == 0) { 267 ipstat.ips_noroute++; 268 error = EHOSTUNREACH; 269 goto bad; 270 } 271 ia = ifatoia(ro->ro_rt->rt_ifa); 272 ifp = ro->ro_rt->rt_ifp; 273 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 274 mtu = ifp->if_mtu; 275 ro->ro_rt->rt_use++; 276 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 277 dst = satosin(ro->ro_rt->rt_gateway); 278 } 279 if (IN_MULTICAST(ip->ip_dst.s_addr) || 280 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 281 struct in_multi *inm; 282 283 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 284 M_BCAST : M_MCAST; 285 /* 286 * IP destination address is multicast. Make sure "dst" 287 * still points to the address in "ro". (It may have been 288 * changed to point to a gateway address, above.) 289 */ 290 dst = satosin(&ro->ro_dst); 291 /* 292 * See if the caller provided any multicast options 293 */ 294 if (imo != NULL) { 295 ip->ip_ttl = imo->imo_multicast_ttl; 296 if (imo->imo_multicast_ifp != NULL) { 297 ifp = imo->imo_multicast_ifp; 298 mtu = ifp->if_mtu; 299 } 300 } else 301 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 302 /* 303 * Confirm that the outgoing interface supports multicast. 304 */ 305 if (((m->m_flags & M_MCAST) && 306 (ifp->if_flags & IFF_MULTICAST) == 0) || 307 ((m->m_flags & M_BCAST) && 308 (ifp->if_flags & IFF_BROADCAST) == 0)) { 309 ipstat.ips_noroute++; 310 error = ENETUNREACH; 311 goto bad; 312 } 313 /* 314 * If source address not specified yet, use an address 315 * of outgoing interface. 316 */ 317 if (in_nullhost(ip->ip_src)) { 318 struct in_ifaddr *ia; 319 320 IFP_TO_IA(ifp, ia); 321 ip->ip_src = ia->ia_addr.sin_addr; 322 } 323 324 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 325 if (inm != NULL && 326 (imo == NULL || imo->imo_multicast_loop)) { 327 /* 328 * If we belong to the destination multicast group 329 * on the outgoing interface, and the caller did not 330 * forbid loopback, loop back a copy. 331 */ 332 ip_mloopback(ifp, m, dst); 333 } 334 #ifdef MROUTING 335 else { 336 /* 337 * If we are acting as a multicast router, perform 338 * multicast forwarding as if the packet had just 339 * arrived on the interface to which we are about 340 * to send. The multicast forwarding function 341 * recursively calls this function, using the 342 * IP_FORWARDING flag to prevent infinite recursion. 343 * 344 * Multicasts that are looped back by ip_mloopback(), 345 * above, will be forwarded by the ip_input() routine, 346 * if necessary. 347 */ 348 extern struct socket *ip_mrouter; 349 350 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 351 if (ip_mforward(m, ifp) != 0) { 352 m_freem(m); 353 goto done; 354 } 355 } 356 } 357 #endif 358 /* 359 * Multicasts with a time-to-live of zero may be looped- 360 * back, above, but must not be transmitted on a network. 361 * Also, multicasts addressed to the loopback interface 362 * are not sent -- the above call to ip_mloopback() will 363 * loop back a copy if this host actually belongs to the 364 * destination group on the loopback interface. 365 */ 366 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 367 m_freem(m); 368 goto done; 369 } 370 371 goto sendit; 372 } 373 #ifndef notdef 374 /* 375 * If source address not specified yet, use address 376 * of outgoing interface. 377 */ 378 if (in_nullhost(ip->ip_src)) 379 ip->ip_src = ia->ia_addr.sin_addr; 380 #endif 381 382 /* 383 * packets with Class-D address as source are not valid per 384 * RFC 1112 385 */ 386 if (IN_MULTICAST(ip->ip_src.s_addr)) { 387 ipstat.ips_odropped++; 388 error = EADDRNOTAVAIL; 389 goto bad; 390 } 391 392 /* 393 * Look for broadcast address and 394 * and verify user is allowed to send 395 * such a packet. 396 */ 397 if (in_broadcast(dst->sin_addr, ifp)) { 398 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 399 error = EADDRNOTAVAIL; 400 goto bad; 401 } 402 if ((flags & IP_ALLOWBROADCAST) == 0) { 403 error = EACCES; 404 goto bad; 405 } 406 /* don't allow broadcast messages to be fragmented */ 407 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 408 error = EMSGSIZE; 409 goto bad; 410 } 411 m->m_flags |= M_BCAST; 412 } else 413 m->m_flags &= ~M_BCAST; 414 415 sendit: 416 /* 417 * If we're doing Path MTU Discovery, we need to set DF unless 418 * the route's MTU is locked. 419 */ 420 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 421 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 422 ip->ip_off |= IP_DF; 423 424 /* 425 * Remember the current ip_len and ip_off, and swap them into 426 * network order. 427 */ 428 ip_len = ip->ip_len; 429 430 HTONS(ip->ip_len); 431 HTONS(ip->ip_off); 432 433 #ifdef IPSEC 434 /* get SP for this packet */ 435 if (so == NULL) 436 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 437 else 438 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 439 440 if (sp == NULL) { 441 ipsecstat.out_inval++; 442 goto bad; 443 } 444 445 error = 0; 446 447 /* check policy */ 448 switch (sp->policy) { 449 case IPSEC_POLICY_DISCARD: 450 /* 451 * This packet is just discarded. 452 */ 453 ipsecstat.out_polvio++; 454 goto bad; 455 456 case IPSEC_POLICY_BYPASS: 457 case IPSEC_POLICY_NONE: 458 /* no need to do IPsec. */ 459 goto skip_ipsec; 460 461 case IPSEC_POLICY_IPSEC: 462 if (sp->req == NULL) { 463 /* XXX should be panic ? */ 464 printf("ip_output: No IPsec request specified.\n"); 465 error = EINVAL; 466 goto bad; 467 } 468 break; 469 470 case IPSEC_POLICY_ENTRUST: 471 default: 472 printf("ip_output: Invalid policy found. %d\n", sp->policy); 473 } 474 475 /* 476 * ipsec4_output() expects ip_len and ip_off in network 477 * order. They have been set to network order above. 478 */ 479 480 { 481 struct ipsec_output_state state; 482 bzero(&state, sizeof(state)); 483 state.m = m; 484 if (flags & IP_ROUTETOIF) { 485 state.ro = &iproute; 486 bzero(&iproute, sizeof(iproute)); 487 } else 488 state.ro = ro; 489 state.dst = (struct sockaddr *)dst; 490 491 error = ipsec4_output(&state, sp, flags); 492 493 m = state.m; 494 if (flags & IP_ROUTETOIF) { 495 /* 496 * if we have tunnel mode SA, we may need to ignore 497 * IP_ROUTETOIF. 498 */ 499 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 500 flags &= ~IP_ROUTETOIF; 501 ro = state.ro; 502 } 503 } else 504 ro = state.ro; 505 dst = (struct sockaddr_in *)state.dst; 506 if (error) { 507 /* mbuf is already reclaimed in ipsec4_output. */ 508 m0 = NULL; 509 switch (error) { 510 case EHOSTUNREACH: 511 case ENETUNREACH: 512 case EMSGSIZE: 513 case ENOBUFS: 514 case ENOMEM: 515 break; 516 default: 517 printf("ip4_output (ipsec): error code %d\n", error); 518 /*fall through*/ 519 case ENOENT: 520 /* don't show these error codes to the user */ 521 error = 0; 522 break; 523 } 524 goto bad; 525 } 526 } 527 528 /* be sure to update variables that are affected by ipsec4_output() */ 529 ip = mtod(m, struct ip *); 530 #ifdef _IP_VHL 531 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 532 #else 533 hlen = ip->ip_hl << 2; 534 #endif 535 ip_len = ntohs(ip->ip_len); 536 537 if (ro->ro_rt == NULL) { 538 if ((flags & IP_ROUTETOIF) == 0) { 539 printf("ip_output: " 540 "can't update route after IPsec processing\n"); 541 error = EHOSTUNREACH; /*XXX*/ 542 goto bad; 543 } 544 } else { 545 /* nobody uses ia beyond here */ 546 ifp = ro->ro_rt->rt_ifp; 547 } 548 549 skip_ipsec: 550 #endif /*IPSEC*/ 551 552 #ifdef PFIL_HOOKS 553 /* 554 * Run through list of hooks for output packets. 555 */ 556 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 557 PFIL_OUT)) != 0) 558 goto done; 559 if (m == NULL) 560 goto done; 561 562 ip = mtod(m, struct ip *); 563 #endif /* PFIL_HOOKS */ 564 565 /* 566 * If small enough for mtu of path, can just send directly. 567 */ 568 if (ip_len <= mtu) { 569 #if IFA_STATS 570 /* 571 * search for the source address structure to 572 * maintain output statistics. 573 */ 574 INADDR_TO_IA(ip->ip_src, ia); 575 if (ia) 576 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 577 #endif 578 ip->ip_sum = 0; 579 ip->ip_sum = in_cksum(m, hlen); 580 #ifdef IPSEC 581 /* clean ipsec history once it goes out of the node */ 582 ipsec_delaux(m); 583 #endif 584 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 585 goto done; 586 } 587 588 /* 589 * Too large for interface; fragment if possible. 590 * Must be able to put at least 8 bytes per fragment. 591 * 592 * Note we swap ip_len and ip_off into host order to make 593 * the logic below a little simpler. 594 */ 595 596 NTOHS(ip->ip_len); 597 NTOHS(ip->ip_off); 598 599 if (ip->ip_off & IP_DF) { 600 if (flags & IP_RETURNMTU) 601 *mtu_p = mtu; 602 error = EMSGSIZE; 603 ipstat.ips_cantfrag++; 604 goto bad; 605 } 606 len = (mtu - hlen) &~ 7; 607 if (len < 8) { 608 error = EMSGSIZE; 609 goto bad; 610 } 611 612 { 613 int mhlen, firstlen = len; 614 struct mbuf **mnext = &m->m_nextpkt; 615 int fragments = 0; 616 int s; 617 618 /* 619 * Loop through length of segment after first fragment, 620 * make new header and copy data of each part and link onto chain. 621 */ 622 m0 = m; 623 mhlen = sizeof (struct ip); 624 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 625 MGETHDR(m, M_DONTWAIT, MT_HEADER); 626 if (m == 0) { 627 error = ENOBUFS; 628 ipstat.ips_odropped++; 629 goto sendorfree; 630 } 631 *mnext = m; 632 mnext = &m->m_nextpkt; 633 m->m_data += max_linkhdr; 634 mhip = mtod(m, struct ip *); 635 *mhip = *ip; 636 /* we must inherit MCAST and BCAST flags */ 637 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 638 if (hlen > sizeof (struct ip)) { 639 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 640 mhip->ip_hl = mhlen >> 2; 641 } 642 m->m_len = mhlen; 643 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 644 if (ip->ip_off & IP_MF) 645 mhip->ip_off |= IP_MF; 646 if (off + len >= (u_int16_t)ip->ip_len) 647 len = (u_int16_t)ip->ip_len - off; 648 else 649 mhip->ip_off |= IP_MF; 650 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 651 m->m_next = m_copy(m0, off, len); 652 if (m->m_next == 0) { 653 error = ENOBUFS; /* ??? */ 654 ipstat.ips_odropped++; 655 goto sendorfree; 656 } 657 m->m_pkthdr.len = mhlen + len; 658 m->m_pkthdr.rcvif = (struct ifnet *)0; 659 HTONS(mhip->ip_off); 660 mhip->ip_sum = 0; 661 mhip->ip_sum = in_cksum(m, mhlen); 662 ipstat.ips_ofragments++; 663 fragments++; 664 } 665 /* 666 * Update first fragment by trimming what's been copied out 667 * and updating header, then send each fragment (in order). 668 */ 669 m = m0; 670 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 671 m->m_pkthdr.len = hlen + firstlen; 672 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 673 ip->ip_off |= IP_MF; 674 HTONS(ip->ip_off); 675 ip->ip_sum = 0; 676 ip->ip_sum = in_cksum(m, hlen); 677 sendorfree: 678 /* 679 * If there is no room for all the fragments, don't queue 680 * any of them. 681 */ 682 s = splnet(); 683 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 684 error = ENOBUFS; 685 splx(s); 686 for (m = m0; m; m = m0) { 687 m0 = m->m_nextpkt; 688 m->m_nextpkt = 0; 689 if (error == 0) { 690 #if IFA_STATS 691 /* 692 * search for the source address structure to 693 * maintain output statistics. 694 */ 695 INADDR_TO_IA(ip->ip_src, ia); 696 if (ia) { 697 ia->ia_ifa.ifa_data.ifad_outbytes += 698 ntohs(ip->ip_len); 699 } 700 #endif 701 #ifdef IPSEC 702 /* clean ipsec history once it goes out of the node */ 703 ipsec_delaux(m); 704 #endif 705 error = (*ifp->if_output)(ifp, m, sintosa(dst), 706 ro->ro_rt); 707 } else 708 m_freem(m); 709 } 710 711 if (error == 0) 712 ipstat.ips_fragmented++; 713 } 714 done: 715 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 716 RTFREE(ro->ro_rt); 717 ro->ro_rt = 0; 718 } 719 720 #ifdef IPSEC 721 if (sp != NULL) { 722 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 723 printf("DP ip_output call free SP:%p\n", sp)); 724 key_freesp(sp); 725 } 726 #endif /* IPSEC */ 727 728 return (error); 729 bad: 730 m_freem(m); 731 goto done; 732 } 733 734 /* 735 * Determine the maximum length of the options to be inserted; 736 * we would far rather allocate too much space rather than too little. 737 */ 738 739 u_int 740 ip_optlen(inp) 741 struct inpcb *inp; 742 { 743 struct mbuf *m = inp->inp_options; 744 745 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 746 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 747 else 748 return 0; 749 } 750 751 752 /* 753 * Insert IP options into preformed packet. 754 * Adjust IP destination as required for IP source routing, 755 * as indicated by a non-zero in_addr at the start of the options. 756 */ 757 static struct mbuf * 758 ip_insertoptions(m, opt, phlen) 759 struct mbuf *m; 760 struct mbuf *opt; 761 int *phlen; 762 { 763 struct ipoption *p = mtod(opt, struct ipoption *); 764 struct mbuf *n; 765 struct ip *ip = mtod(m, struct ip *); 766 unsigned optlen; 767 768 optlen = opt->m_len - sizeof(p->ipopt_dst); 769 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 770 return (m); /* XXX should fail */ 771 if (!in_nullhost(p->ipopt_dst)) 772 ip->ip_dst = p->ipopt_dst; 773 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 774 MGETHDR(n, M_DONTWAIT, MT_HEADER); 775 if (n == 0) 776 return (m); 777 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 778 m->m_len -= sizeof(struct ip); 779 m->m_data += sizeof(struct ip); 780 n->m_next = m; 781 m = n; 782 m->m_len = optlen + sizeof(struct ip); 783 m->m_data += max_linkhdr; 784 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 785 } else { 786 m->m_data -= optlen; 787 m->m_len += optlen; 788 m->m_pkthdr.len += optlen; 789 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 790 } 791 ip = mtod(m, struct ip *); 792 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 793 *phlen = sizeof(struct ip) + optlen; 794 ip->ip_len += optlen; 795 return (m); 796 } 797 798 /* 799 * Copy options from ip to jp, 800 * omitting those not copied during fragmentation. 801 */ 802 int 803 ip_optcopy(ip, jp) 804 struct ip *ip, *jp; 805 { 806 u_char *cp, *dp; 807 int opt, optlen, cnt; 808 809 cp = (u_char *)(ip + 1); 810 dp = (u_char *)(jp + 1); 811 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 812 for (; cnt > 0; cnt -= optlen, cp += optlen) { 813 opt = cp[0]; 814 if (opt == IPOPT_EOL) 815 break; 816 if (opt == IPOPT_NOP) { 817 /* Preserve for IP mcast tunnel's LSRR alignment. */ 818 *dp++ = IPOPT_NOP; 819 optlen = 1; 820 continue; 821 } 822 #ifdef DIAGNOSTIC 823 if (cnt < IPOPT_OLEN + sizeof(*cp)) 824 panic("malformed IPv4 option passed to ip_optcopy"); 825 #endif 826 optlen = cp[IPOPT_OLEN]; 827 #ifdef DIAGNOSTIC 828 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 829 panic("malformed IPv4 option passed to ip_optcopy"); 830 #endif 831 /* bogus lengths should have been caught by ip_dooptions */ 832 if (optlen > cnt) 833 optlen = cnt; 834 if (IPOPT_COPIED(opt)) { 835 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 836 dp += optlen; 837 } 838 } 839 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 840 *dp++ = IPOPT_EOL; 841 return (optlen); 842 } 843 844 /* 845 * IP socket option processing. 846 */ 847 int 848 ip_ctloutput(op, so, level, optname, mp) 849 int op; 850 struct socket *so; 851 int level, optname; 852 struct mbuf **mp; 853 { 854 struct inpcb *inp = sotoinpcb(so); 855 struct mbuf *m = *mp; 856 int optval = 0; 857 int error = 0; 858 #ifdef IPSEC 859 #ifdef __NetBSD__ 860 struct proc *p = curproc; /*XXX*/ 861 #endif 862 #endif 863 864 if (level != IPPROTO_IP) { 865 error = EINVAL; 866 if (op == PRCO_SETOPT && *mp) 867 (void) m_free(*mp); 868 } else switch (op) { 869 870 case PRCO_SETOPT: 871 switch (optname) { 872 case IP_OPTIONS: 873 #ifdef notyet 874 case IP_RETOPTS: 875 return (ip_pcbopts(optname, &inp->inp_options, m)); 876 #else 877 return (ip_pcbopts(&inp->inp_options, m)); 878 #endif 879 880 case IP_TOS: 881 case IP_TTL: 882 case IP_RECVOPTS: 883 case IP_RECVRETOPTS: 884 case IP_RECVDSTADDR: 885 case IP_RECVIF: 886 if (m == NULL || m->m_len != sizeof(int)) 887 error = EINVAL; 888 else { 889 optval = *mtod(m, int *); 890 switch (optname) { 891 892 case IP_TOS: 893 inp->inp_ip.ip_tos = optval; 894 break; 895 896 case IP_TTL: 897 inp->inp_ip.ip_ttl = optval; 898 break; 899 #define OPTSET(bit) \ 900 if (optval) \ 901 inp->inp_flags |= bit; \ 902 else \ 903 inp->inp_flags &= ~bit; 904 905 case IP_RECVOPTS: 906 OPTSET(INP_RECVOPTS); 907 break; 908 909 case IP_RECVRETOPTS: 910 OPTSET(INP_RECVRETOPTS); 911 break; 912 913 case IP_RECVDSTADDR: 914 OPTSET(INP_RECVDSTADDR); 915 break; 916 917 case IP_RECVIF: 918 OPTSET(INP_RECVIF); 919 break; 920 } 921 } 922 break; 923 #undef OPTSET 924 925 case IP_MULTICAST_IF: 926 case IP_MULTICAST_TTL: 927 case IP_MULTICAST_LOOP: 928 case IP_ADD_MEMBERSHIP: 929 case IP_DROP_MEMBERSHIP: 930 error = ip_setmoptions(optname, &inp->inp_moptions, m); 931 break; 932 933 case IP_PORTRANGE: 934 if (m == 0 || m->m_len != sizeof(int)) 935 error = EINVAL; 936 else { 937 optval = *mtod(m, int *); 938 939 switch (optval) { 940 941 case IP_PORTRANGE_DEFAULT: 942 case IP_PORTRANGE_HIGH: 943 inp->inp_flags &= ~(INP_LOWPORT); 944 break; 945 946 case IP_PORTRANGE_LOW: 947 inp->inp_flags |= INP_LOWPORT; 948 break; 949 950 default: 951 error = EINVAL; 952 break; 953 } 954 } 955 break; 956 957 #ifdef IPSEC 958 case IP_IPSEC_POLICY: 959 { 960 caddr_t req = NULL; 961 size_t len = 0; 962 int priv = 0; 963 964 #ifdef __NetBSD__ 965 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 966 priv = 0; 967 else 968 priv = 1; 969 #else 970 priv = (in6p->in6p_socket->so_state & SS_PRIV); 971 #endif 972 if (m) { 973 req = mtod(m, caddr_t); 974 len = m->m_len; 975 } 976 error = ipsec4_set_policy(inp, optname, req, len, priv); 977 break; 978 } 979 #endif /*IPSEC*/ 980 981 default: 982 error = ENOPROTOOPT; 983 break; 984 } 985 if (m) 986 (void)m_free(m); 987 break; 988 989 case PRCO_GETOPT: 990 switch (optname) { 991 case IP_OPTIONS: 992 case IP_RETOPTS: 993 *mp = m = m_get(M_WAIT, MT_SOOPTS); 994 if (inp->inp_options) { 995 m->m_len = inp->inp_options->m_len; 996 bcopy(mtod(inp->inp_options, caddr_t), 997 mtod(m, caddr_t), (unsigned)m->m_len); 998 } else 999 m->m_len = 0; 1000 break; 1001 1002 case IP_TOS: 1003 case IP_TTL: 1004 case IP_RECVOPTS: 1005 case IP_RECVRETOPTS: 1006 case IP_RECVDSTADDR: 1007 case IP_RECVIF: 1008 case IP_ERRORMTU: 1009 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1010 m->m_len = sizeof(int); 1011 switch (optname) { 1012 1013 case IP_TOS: 1014 optval = inp->inp_ip.ip_tos; 1015 break; 1016 1017 case IP_TTL: 1018 optval = inp->inp_ip.ip_ttl; 1019 break; 1020 1021 case IP_ERRORMTU: 1022 optval = inp->inp_errormtu; 1023 break; 1024 1025 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1026 1027 case IP_RECVOPTS: 1028 optval = OPTBIT(INP_RECVOPTS); 1029 break; 1030 1031 case IP_RECVRETOPTS: 1032 optval = OPTBIT(INP_RECVRETOPTS); 1033 break; 1034 1035 case IP_RECVDSTADDR: 1036 optval = OPTBIT(INP_RECVDSTADDR); 1037 break; 1038 1039 case IP_RECVIF: 1040 optval = OPTBIT(INP_RECVIF); 1041 break; 1042 } 1043 *mtod(m, int *) = optval; 1044 break; 1045 1046 #ifdef IPSEC 1047 case IP_IPSEC_POLICY: 1048 { 1049 caddr_t req = NULL; 1050 size_t len = 0; 1051 1052 if (m) { 1053 req = mtod(m, caddr_t); 1054 len = m->m_len; 1055 } 1056 error = ipsec4_get_policy(inp, req, len, mp); 1057 break; 1058 } 1059 #endif /*IPSEC*/ 1060 1061 case IP_MULTICAST_IF: 1062 case IP_MULTICAST_TTL: 1063 case IP_MULTICAST_LOOP: 1064 case IP_ADD_MEMBERSHIP: 1065 case IP_DROP_MEMBERSHIP: 1066 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1067 break; 1068 1069 case IP_PORTRANGE: 1070 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1071 m->m_len = sizeof(int); 1072 1073 if (inp->inp_flags & INP_LOWPORT) 1074 optval = IP_PORTRANGE_LOW; 1075 else 1076 optval = IP_PORTRANGE_DEFAULT; 1077 1078 *mtod(m, int *) = optval; 1079 break; 1080 1081 default: 1082 error = ENOPROTOOPT; 1083 break; 1084 } 1085 break; 1086 } 1087 return (error); 1088 } 1089 1090 /* 1091 * Set up IP options in pcb for insertion in output packets. 1092 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1093 * with destination address if source routed. 1094 */ 1095 int 1096 #ifdef notyet 1097 ip_pcbopts(optname, pcbopt, m) 1098 int optname; 1099 #else 1100 ip_pcbopts(pcbopt, m) 1101 #endif 1102 struct mbuf **pcbopt; 1103 struct mbuf *m; 1104 { 1105 int cnt, optlen; 1106 u_char *cp; 1107 u_char opt; 1108 1109 /* turn off any old options */ 1110 if (*pcbopt) 1111 (void)m_free(*pcbopt); 1112 *pcbopt = 0; 1113 if (m == (struct mbuf *)0 || m->m_len == 0) { 1114 /* 1115 * Only turning off any previous options. 1116 */ 1117 if (m) 1118 (void)m_free(m); 1119 return (0); 1120 } 1121 1122 #ifndef vax 1123 if (m->m_len % sizeof(int32_t)) 1124 goto bad; 1125 #endif 1126 /* 1127 * IP first-hop destination address will be stored before 1128 * actual options; move other options back 1129 * and clear it when none present. 1130 */ 1131 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1132 goto bad; 1133 cnt = m->m_len; 1134 m->m_len += sizeof(struct in_addr); 1135 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1136 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1137 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1138 1139 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1140 opt = cp[IPOPT_OPTVAL]; 1141 if (opt == IPOPT_EOL) 1142 break; 1143 if (opt == IPOPT_NOP) 1144 optlen = 1; 1145 else { 1146 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1147 goto bad; 1148 optlen = cp[IPOPT_OLEN]; 1149 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1150 goto bad; 1151 } 1152 switch (opt) { 1153 1154 default: 1155 break; 1156 1157 case IPOPT_LSRR: 1158 case IPOPT_SSRR: 1159 /* 1160 * user process specifies route as: 1161 * ->A->B->C->D 1162 * D must be our final destination (but we can't 1163 * check that since we may not have connected yet). 1164 * A is first hop destination, which doesn't appear in 1165 * actual IP option, but is stored before the options. 1166 */ 1167 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1168 goto bad; 1169 m->m_len -= sizeof(struct in_addr); 1170 cnt -= sizeof(struct in_addr); 1171 optlen -= sizeof(struct in_addr); 1172 cp[IPOPT_OLEN] = optlen; 1173 /* 1174 * Move first hop before start of options. 1175 */ 1176 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1177 sizeof(struct in_addr)); 1178 /* 1179 * Then copy rest of options back 1180 * to close up the deleted entry. 1181 */ 1182 memmove(&cp[IPOPT_OFFSET+1], 1183 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1184 (unsigned)cnt + sizeof(struct in_addr)); 1185 break; 1186 } 1187 } 1188 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1189 goto bad; 1190 *pcbopt = m; 1191 return (0); 1192 1193 bad: 1194 (void)m_free(m); 1195 return (EINVAL); 1196 } 1197 1198 /* 1199 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1200 */ 1201 static struct ifnet * 1202 ip_multicast_if(a, ifindexp) 1203 struct in_addr *a; 1204 int *ifindexp; 1205 { 1206 int ifindex; 1207 struct ifnet *ifp; 1208 1209 if (ifindexp) 1210 *ifindexp = 0; 1211 if (ntohl(a->s_addr) >> 24 == 0) { 1212 ifindex = ntohl(a->s_addr) & 0xffffff; 1213 if (ifindex < 0 || if_index < ifindex) 1214 return NULL; 1215 ifp = ifindex2ifnet[ifindex]; 1216 if (ifindexp) 1217 *ifindexp = ifindex; 1218 } else { 1219 INADDR_TO_IFP(*a, ifp); 1220 } 1221 return ifp; 1222 } 1223 1224 /* 1225 * Set the IP multicast options in response to user setsockopt(). 1226 */ 1227 int 1228 ip_setmoptions(optname, imop, m) 1229 int optname; 1230 struct ip_moptions **imop; 1231 struct mbuf *m; 1232 { 1233 int error = 0; 1234 u_char loop; 1235 int i; 1236 struct in_addr addr; 1237 struct ip_mreq *mreq; 1238 struct ifnet *ifp; 1239 struct ip_moptions *imo = *imop; 1240 struct route ro; 1241 struct sockaddr_in *dst; 1242 int ifindex; 1243 1244 if (imo == NULL) { 1245 /* 1246 * No multicast option buffer attached to the pcb; 1247 * allocate one and initialize to default values. 1248 */ 1249 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1250 M_WAITOK); 1251 1252 if (imo == NULL) 1253 return (ENOBUFS); 1254 *imop = imo; 1255 imo->imo_multicast_ifp = NULL; 1256 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1257 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1258 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1259 imo->imo_num_memberships = 0; 1260 } 1261 1262 switch (optname) { 1263 1264 case IP_MULTICAST_IF: 1265 /* 1266 * Select the interface for outgoing multicast packets. 1267 */ 1268 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1269 error = EINVAL; 1270 break; 1271 } 1272 addr = *(mtod(m, struct in_addr *)); 1273 /* 1274 * INADDR_ANY is used to remove a previous selection. 1275 * When no interface is selected, a default one is 1276 * chosen every time a multicast packet is sent. 1277 */ 1278 if (in_nullhost(addr)) { 1279 imo->imo_multicast_ifp = NULL; 1280 break; 1281 } 1282 /* 1283 * The selected interface is identified by its local 1284 * IP address. Find the interface and confirm that 1285 * it supports multicasting. 1286 */ 1287 ifp = ip_multicast_if(&addr, &ifindex); 1288 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1289 error = EADDRNOTAVAIL; 1290 break; 1291 } 1292 imo->imo_multicast_ifp = ifp; 1293 if (ifindex) 1294 imo->imo_multicast_addr = addr; 1295 else 1296 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1297 break; 1298 1299 case IP_MULTICAST_TTL: 1300 /* 1301 * Set the IP time-to-live for outgoing multicast packets. 1302 */ 1303 if (m == NULL || m->m_len != 1) { 1304 error = EINVAL; 1305 break; 1306 } 1307 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1308 break; 1309 1310 case IP_MULTICAST_LOOP: 1311 /* 1312 * Set the loopback flag for outgoing multicast packets. 1313 * Must be zero or one. 1314 */ 1315 if (m == NULL || m->m_len != 1 || 1316 (loop = *(mtod(m, u_char *))) > 1) { 1317 error = EINVAL; 1318 break; 1319 } 1320 imo->imo_multicast_loop = loop; 1321 break; 1322 1323 case IP_ADD_MEMBERSHIP: 1324 /* 1325 * Add a multicast group membership. 1326 * Group must be a valid IP multicast address. 1327 */ 1328 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1329 error = EINVAL; 1330 break; 1331 } 1332 mreq = mtod(m, struct ip_mreq *); 1333 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1334 error = EINVAL; 1335 break; 1336 } 1337 /* 1338 * If no interface address was provided, use the interface of 1339 * the route to the given multicast address. 1340 */ 1341 if (in_nullhost(mreq->imr_interface)) { 1342 bzero((caddr_t)&ro, sizeof(ro)); 1343 ro.ro_rt = NULL; 1344 dst = satosin(&ro.ro_dst); 1345 dst->sin_len = sizeof(*dst); 1346 dst->sin_family = AF_INET; 1347 dst->sin_addr = mreq->imr_multiaddr; 1348 rtalloc(&ro); 1349 if (ro.ro_rt == NULL) { 1350 error = EADDRNOTAVAIL; 1351 break; 1352 } 1353 ifp = ro.ro_rt->rt_ifp; 1354 rtfree(ro.ro_rt); 1355 } else { 1356 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1357 } 1358 /* 1359 * See if we found an interface, and confirm that it 1360 * supports multicast. 1361 */ 1362 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1363 error = EADDRNOTAVAIL; 1364 break; 1365 } 1366 /* 1367 * See if the membership already exists or if all the 1368 * membership slots are full. 1369 */ 1370 for (i = 0; i < imo->imo_num_memberships; ++i) { 1371 if (imo->imo_membership[i]->inm_ifp == ifp && 1372 in_hosteq(imo->imo_membership[i]->inm_addr, 1373 mreq->imr_multiaddr)) 1374 break; 1375 } 1376 if (i < imo->imo_num_memberships) { 1377 error = EADDRINUSE; 1378 break; 1379 } 1380 if (i == IP_MAX_MEMBERSHIPS) { 1381 error = ETOOMANYREFS; 1382 break; 1383 } 1384 /* 1385 * Everything looks good; add a new record to the multicast 1386 * address list for the given interface. 1387 */ 1388 if ((imo->imo_membership[i] = 1389 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1390 error = ENOBUFS; 1391 break; 1392 } 1393 ++imo->imo_num_memberships; 1394 break; 1395 1396 case IP_DROP_MEMBERSHIP: 1397 /* 1398 * Drop a multicast group membership. 1399 * Group must be a valid IP multicast address. 1400 */ 1401 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1402 error = EINVAL; 1403 break; 1404 } 1405 mreq = mtod(m, struct ip_mreq *); 1406 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1407 error = EINVAL; 1408 break; 1409 } 1410 /* 1411 * If an interface address was specified, get a pointer 1412 * to its ifnet structure. 1413 */ 1414 if (in_nullhost(mreq->imr_interface)) 1415 ifp = NULL; 1416 else { 1417 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1418 if (ifp == NULL) { 1419 error = EADDRNOTAVAIL; 1420 break; 1421 } 1422 } 1423 /* 1424 * Find the membership in the membership array. 1425 */ 1426 for (i = 0; i < imo->imo_num_memberships; ++i) { 1427 if ((ifp == NULL || 1428 imo->imo_membership[i]->inm_ifp == ifp) && 1429 in_hosteq(imo->imo_membership[i]->inm_addr, 1430 mreq->imr_multiaddr)) 1431 break; 1432 } 1433 if (i == imo->imo_num_memberships) { 1434 error = EADDRNOTAVAIL; 1435 break; 1436 } 1437 /* 1438 * Give up the multicast address record to which the 1439 * membership points. 1440 */ 1441 in_delmulti(imo->imo_membership[i]); 1442 /* 1443 * Remove the gap in the membership array. 1444 */ 1445 for (++i; i < imo->imo_num_memberships; ++i) 1446 imo->imo_membership[i-1] = imo->imo_membership[i]; 1447 --imo->imo_num_memberships; 1448 break; 1449 1450 default: 1451 error = EOPNOTSUPP; 1452 break; 1453 } 1454 1455 /* 1456 * If all options have default values, no need to keep the mbuf. 1457 */ 1458 if (imo->imo_multicast_ifp == NULL && 1459 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1460 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1461 imo->imo_num_memberships == 0) { 1462 free(*imop, M_IPMOPTS); 1463 *imop = NULL; 1464 } 1465 1466 return (error); 1467 } 1468 1469 /* 1470 * Return the IP multicast options in response to user getsockopt(). 1471 */ 1472 int 1473 ip_getmoptions(optname, imo, mp) 1474 int optname; 1475 struct ip_moptions *imo; 1476 struct mbuf **mp; 1477 { 1478 u_char *ttl; 1479 u_char *loop; 1480 struct in_addr *addr; 1481 struct in_ifaddr *ia; 1482 1483 *mp = m_get(M_WAIT, MT_SOOPTS); 1484 1485 switch (optname) { 1486 1487 case IP_MULTICAST_IF: 1488 addr = mtod(*mp, struct in_addr *); 1489 (*mp)->m_len = sizeof(struct in_addr); 1490 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1491 *addr = zeroin_addr; 1492 else if (imo->imo_multicast_addr.s_addr) { 1493 /* return the value user has set */ 1494 *addr = imo->imo_multicast_addr; 1495 } else { 1496 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1497 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1498 } 1499 return (0); 1500 1501 case IP_MULTICAST_TTL: 1502 ttl = mtod(*mp, u_char *); 1503 (*mp)->m_len = 1; 1504 *ttl = imo ? imo->imo_multicast_ttl 1505 : IP_DEFAULT_MULTICAST_TTL; 1506 return (0); 1507 1508 case IP_MULTICAST_LOOP: 1509 loop = mtod(*mp, u_char *); 1510 (*mp)->m_len = 1; 1511 *loop = imo ? imo->imo_multicast_loop 1512 : IP_DEFAULT_MULTICAST_LOOP; 1513 return (0); 1514 1515 default: 1516 return (EOPNOTSUPP); 1517 } 1518 } 1519 1520 /* 1521 * Discard the IP multicast options. 1522 */ 1523 void 1524 ip_freemoptions(imo) 1525 struct ip_moptions *imo; 1526 { 1527 int i; 1528 1529 if (imo != NULL) { 1530 for (i = 0; i < imo->imo_num_memberships; ++i) 1531 in_delmulti(imo->imo_membership[i]); 1532 free(imo, M_IPMOPTS); 1533 } 1534 } 1535 1536 /* 1537 * Routine called from ip_output() to loop back a copy of an IP multicast 1538 * packet to the input queue of a specified interface. Note that this 1539 * calls the output routine of the loopback "driver", but with an interface 1540 * pointer that might NOT be &loif -- easier than replicating that code here. 1541 */ 1542 static void 1543 ip_mloopback(ifp, m, dst) 1544 struct ifnet *ifp; 1545 struct mbuf *m; 1546 struct sockaddr_in *dst; 1547 { 1548 struct ip *ip; 1549 struct mbuf *copym; 1550 1551 copym = m_copy(m, 0, M_COPYALL); 1552 if (copym != NULL 1553 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1554 copym = m_pullup(copym, sizeof(struct ip)); 1555 if (copym != NULL) { 1556 /* 1557 * We don't bother to fragment if the IP length is greater 1558 * than the interface's MTU. Can this possibly matter? 1559 */ 1560 ip = mtod(copym, struct ip *); 1561 HTONS(ip->ip_len); 1562 HTONS(ip->ip_off); 1563 ip->ip_sum = 0; 1564 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1565 (void) looutput(ifp, copym, sintosa(dst), NULL); 1566 } 1567 } 1568