1 /* $NetBSD: ip_output.c,v 1.74 2000/05/10 03:31:30 itojun 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> 116 117 #include <vm/vm.h> 118 #include <sys/proc.h> 119 120 #include <net/if.h> 121 #include <net/route.h> 122 #include <net/pfil.h> 123 124 #include <netinet/in.h> 125 #include <netinet/in_systm.h> 126 #include <netinet/ip.h> 127 #include <netinet/in_pcb.h> 128 #include <netinet/in_var.h> 129 #include <netinet/ip_var.h> 130 131 #ifdef MROUTING 132 #include <netinet/ip_mroute.h> 133 #endif 134 135 #ifdef __vax__ 136 #include <machine/mtpr.h> 137 #endif 138 139 #include <machine/stdarg.h> 140 141 #ifdef IPSEC 142 #include <netinet6/ipsec.h> 143 #include <netkey/key.h> 144 #include <netkey/key_debug.h> 145 #endif /*IPSEC*/ 146 147 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 148 static void ip_mloopback 149 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); 150 151 /* 152 * IP output. The packet in mbuf chain m contains a skeletal IP 153 * header (with len, off, ttl, proto, tos, src, dst). 154 * The mbuf chain containing the packet will be freed. 155 * The mbuf opt, if present, will not be freed. 156 */ 157 int 158 #if __STDC__ 159 ip_output(struct mbuf *m0, ...) 160 #else 161 ip_output(m0, va_alist) 162 struct mbuf *m0; 163 va_dcl 164 #endif 165 { 166 struct ip *ip, *mhip; 167 struct ifnet *ifp; 168 struct mbuf *m = m0; 169 int hlen = sizeof (struct ip); 170 int len, off, error = 0; 171 struct route iproute; 172 struct sockaddr_in *dst; 173 #if IFA_STATS 174 struct sockaddr_in src; 175 #endif 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 PFIL_HOOKS 185 struct packet_filter_hook *pfh; 186 struct mbuf *m1; 187 int rv; 188 #endif /* PFIL_HOOKS */ 189 #ifdef IPSEC 190 struct socket *so; 191 struct secpolicy *sp = NULL; 192 #endif /*IPSEC*/ 193 194 va_start(ap, m0); 195 opt = va_arg(ap, struct mbuf *); 196 ro = va_arg(ap, struct route *); 197 flags = va_arg(ap, int); 198 imo = va_arg(ap, struct ip_moptions *); 199 if (flags & IP_RETURNMTU) 200 mtu_p = va_arg(ap, int *); 201 else 202 mtu_p = NULL; 203 va_end(ap); 204 205 #ifdef IPSEC 206 so = ipsec_getsocket(m); 207 ipsec_setsocket(m, NULL); 208 #endif /*IPSEC*/ 209 210 #ifdef DIAGNOSTIC 211 if ((m->m_flags & M_PKTHDR) == 0) 212 panic("ip_output no HDR"); 213 #endif 214 if (opt) { 215 m = ip_insertoptions(m, opt, &len); 216 hlen = len; 217 } 218 ip = mtod(m, struct ip *); 219 /* 220 * Fill in IP header. 221 */ 222 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 223 ip->ip_v = IPVERSION; 224 ip->ip_off &= IP_DF; 225 ip->ip_id = htons(ip_id++); 226 ip->ip_hl = hlen >> 2; 227 ipstat.ips_localout++; 228 } else { 229 hlen = ip->ip_hl << 2; 230 } 231 /* 232 * Route packet. 233 */ 234 if (ro == 0) { 235 ro = &iproute; 236 bzero((caddr_t)ro, sizeof (*ro)); 237 } 238 dst = satosin(&ro->ro_dst); 239 /* 240 * If there is a cached route, 241 * check that it is to the same destination 242 * and is still up. If not, free it and try again. 243 */ 244 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 245 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 246 RTFREE(ro->ro_rt); 247 ro->ro_rt = (struct rtentry *)0; 248 } 249 if (ro->ro_rt == 0) { 250 dst->sin_family = AF_INET; 251 dst->sin_len = sizeof(*dst); 252 dst->sin_addr = ip->ip_dst; 253 } 254 /* 255 * If routing to interface only, 256 * short circuit routing lookup. 257 */ 258 if (flags & IP_ROUTETOIF) { 259 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 260 ipstat.ips_noroute++; 261 error = ENETUNREACH; 262 goto bad; 263 } 264 ifp = ia->ia_ifp; 265 mtu = ifp->if_mtu; 266 ip->ip_ttl = 1; 267 } else { 268 if (ro->ro_rt == 0) 269 rtalloc(ro); 270 if (ro->ro_rt == 0) { 271 ipstat.ips_noroute++; 272 error = EHOSTUNREACH; 273 goto bad; 274 } 275 ia = ifatoia(ro->ro_rt->rt_ifa); 276 ifp = ro->ro_rt->rt_ifp; 277 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 278 mtu = ifp->if_mtu; 279 ro->ro_rt->rt_use++; 280 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 281 dst = satosin(ro->ro_rt->rt_gateway); 282 } 283 if (IN_MULTICAST(ip->ip_dst.s_addr) || 284 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 285 struct in_multi *inm; 286 287 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 288 M_BCAST : M_MCAST; 289 /* 290 * IP destination address is multicast. Make sure "dst" 291 * still points to the address in "ro". (It may have been 292 * changed to point to a gateway address, above.) 293 */ 294 dst = satosin(&ro->ro_dst); 295 /* 296 * See if the caller provided any multicast options 297 */ 298 if (imo != NULL) { 299 ip->ip_ttl = imo->imo_multicast_ttl; 300 if (imo->imo_multicast_ifp != NULL) { 301 ifp = imo->imo_multicast_ifp; 302 mtu = ifp->if_mtu; 303 } 304 } else 305 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 306 /* 307 * Confirm that the outgoing interface supports multicast. 308 */ 309 if (((m->m_flags & M_MCAST) && 310 (ifp->if_flags & IFF_MULTICAST) == 0) || 311 ((m->m_flags & M_BCAST) && 312 (ifp->if_flags & IFF_BROADCAST) == 0)) { 313 ipstat.ips_noroute++; 314 error = ENETUNREACH; 315 goto bad; 316 } 317 /* 318 * If source address not specified yet, use an address 319 * of outgoing interface. 320 */ 321 if (in_nullhost(ip->ip_src)) { 322 struct in_ifaddr *ia; 323 324 IFP_TO_IA(ifp, ia); 325 ip->ip_src = ia->ia_addr.sin_addr; 326 } 327 328 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 329 if (inm != NULL && 330 (imo == NULL || imo->imo_multicast_loop)) { 331 /* 332 * If we belong to the destination multicast group 333 * on the outgoing interface, and the caller did not 334 * forbid loopback, loop back a copy. 335 */ 336 ip_mloopback(ifp, m, dst); 337 } 338 #ifdef MROUTING 339 else { 340 /* 341 * If we are acting as a multicast router, perform 342 * multicast forwarding as if the packet had just 343 * arrived on the interface to which we are about 344 * to send. The multicast forwarding function 345 * recursively calls this function, using the 346 * IP_FORWARDING flag to prevent infinite recursion. 347 * 348 * Multicasts that are looped back by ip_mloopback(), 349 * above, will be forwarded by the ip_input() routine, 350 * if necessary. 351 */ 352 extern struct socket *ip_mrouter; 353 354 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 355 if (ip_mforward(m, ifp) != 0) { 356 m_freem(m); 357 goto done; 358 } 359 } 360 } 361 #endif 362 /* 363 * Multicasts with a time-to-live of zero may be looped- 364 * back, above, but must not be transmitted on a network. 365 * Also, multicasts addressed to the loopback interface 366 * are not sent -- the above call to ip_mloopback() will 367 * loop back a copy if this host actually belongs to the 368 * destination group on the loopback interface. 369 */ 370 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 371 m_freem(m); 372 goto done; 373 } 374 375 goto sendit; 376 } 377 #ifndef notdef 378 /* 379 * If source address not specified yet, use address 380 * of outgoing interface. 381 */ 382 if (in_nullhost(ip->ip_src)) 383 ip->ip_src = ia->ia_addr.sin_addr; 384 #endif 385 386 /* 387 * packets with Class-D address as source are not valid per 388 * RFC 1112 389 */ 390 if (IN_MULTICAST(ip->ip_src.s_addr)) { 391 ipstat.ips_odropped++; 392 error = EADDRNOTAVAIL; 393 goto bad; 394 } 395 396 /* 397 * Look for broadcast address and 398 * and verify user is allowed to send 399 * such a packet. 400 */ 401 if (in_broadcast(dst->sin_addr, ifp)) { 402 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 403 error = EADDRNOTAVAIL; 404 goto bad; 405 } 406 if ((flags & IP_ALLOWBROADCAST) == 0) { 407 error = EACCES; 408 goto bad; 409 } 410 /* don't allow broadcast messages to be fragmented */ 411 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 412 error = EMSGSIZE; 413 goto bad; 414 } 415 m->m_flags |= M_BCAST; 416 } else 417 m->m_flags &= ~M_BCAST; 418 419 sendit: 420 #ifdef PFIL_HOOKS 421 /* 422 * Run through list of hooks for output packets. 423 */ 424 m1 = m; 425 pfh = pfil_hook_get(PFIL_OUT, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh); 426 for (; pfh; pfh = pfh->pfil_link.tqe_next) 427 if (pfh->pfil_func) { 428 rv = pfh->pfil_func(ip, hlen, ifp, 1, &m1); 429 if (rv) { 430 error = EHOSTUNREACH; 431 goto done; 432 } 433 m = m1; 434 if (m == NULL) 435 goto done; 436 ip = mtod(m, struct ip *); 437 } 438 #endif /* PFIL_HOOKS */ 439 440 #ifdef IPSEC 441 /* get SP for this packet */ 442 if (so == NULL) 443 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 444 else 445 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 446 447 if (sp == NULL) { 448 ipsecstat.out_inval++; 449 goto bad; 450 } 451 452 error = 0; 453 454 /* check policy */ 455 switch (sp->policy) { 456 case IPSEC_POLICY_DISCARD: 457 /* 458 * This packet is just discarded. 459 */ 460 ipsecstat.out_polvio++; 461 goto bad; 462 463 case IPSEC_POLICY_BYPASS: 464 case IPSEC_POLICY_NONE: 465 /* no need to do IPsec. */ 466 goto skip_ipsec; 467 468 case IPSEC_POLICY_IPSEC: 469 if (sp->req == NULL) { 470 /* XXX should be panic ? */ 471 printf("ip_output: No IPsec request specified.\n"); 472 error = EINVAL; 473 goto bad; 474 } 475 break; 476 477 case IPSEC_POLICY_ENTRUST: 478 default: 479 printf("ip_output: Invalid policy found. %d\n", sp->policy); 480 } 481 482 ip->ip_len = htons((u_short)ip->ip_len); 483 ip->ip_off = htons((u_short)ip->ip_off); 484 ip->ip_sum = 0; 485 486 { 487 struct ipsec_output_state state; 488 bzero(&state, sizeof(state)); 489 state.m = m; 490 if (flags & IP_ROUTETOIF) { 491 state.ro = &iproute; 492 bzero(&iproute, sizeof(iproute)); 493 } else 494 state.ro = ro; 495 state.dst = (struct sockaddr *)dst; 496 497 error = ipsec4_output(&state, sp, flags); 498 499 m = state.m; 500 if (flags & IP_ROUTETOIF) { 501 /* 502 * if we have tunnel mode SA, we may need to ignore 503 * IP_ROUTETOIF. 504 */ 505 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 506 flags &= ~IP_ROUTETOIF; 507 ro = state.ro; 508 } 509 } else 510 ro = state.ro; 511 dst = (struct sockaddr_in *)state.dst; 512 if (error) { 513 /* mbuf is already reclaimed in ipsec4_output. */ 514 m0 = NULL; 515 switch (error) { 516 case EHOSTUNREACH: 517 case ENETUNREACH: 518 case EMSGSIZE: 519 case ENOBUFS: 520 case ENOMEM: 521 break; 522 default: 523 printf("ip4_output (ipsec): error code %d\n", error); 524 /*fall through*/ 525 case ENOENT: 526 /* don't show these error codes to the user */ 527 error = 0; 528 break; 529 } 530 goto bad; 531 } 532 } 533 534 /* be sure to update variables that are affected by ipsec4_output() */ 535 ip = mtod(m, struct ip *); 536 #ifdef _IP_VHL 537 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 538 #else 539 hlen = ip->ip_hl << 2; 540 #endif 541 if (ro->ro_rt == NULL) { 542 if ((flags & IP_ROUTETOIF) == 0) { 543 printf("ip_output: " 544 "can't update route after IPsec processing\n"); 545 error = EHOSTUNREACH; /*XXX*/ 546 goto bad; 547 } 548 } else { 549 /* nobody uses ia beyond here */ 550 ifp = ro->ro_rt->rt_ifp; 551 } 552 553 /* make it flipped, again. */ 554 ip->ip_len = ntohs((u_short)ip->ip_len); 555 ip->ip_off = ntohs((u_short)ip->ip_off); 556 skip_ipsec: 557 #endif /*IPSEC*/ 558 559 /* 560 * If small enough for mtu of path, can just send directly. 561 */ 562 if ((u_int16_t)ip->ip_len <= mtu) { 563 #if IFA_STATS 564 /* 565 * search for the source address structure to 566 * maintain output statistics. 567 */ 568 bzero((caddr_t*) &src, sizeof(src)); 569 src.sin_family = AF_INET; 570 src.sin_addr.s_addr = ip->ip_src.s_addr; 571 src.sin_len = sizeof(src); 572 ia = ifatoia(ifa_ifwithladdr(sintosa(&src))); 573 if (ia) 574 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 575 #endif 576 HTONS(ip->ip_len); 577 HTONS(ip->ip_off); 578 ip->ip_sum = 0; 579 ip->ip_sum = in_cksum(m, hlen); 580 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 581 goto done; 582 } 583 584 /* 585 * Too large for interface; fragment if possible. 586 * Must be able to put at least 8 bytes per fragment. 587 */ 588 #if 0 589 /* 590 * If IPsec packet is too big for the interface, try fragment it. 591 * XXX This really is a quickhack. May be inappropriate. 592 * XXX fails if somebody is sending AH'ed packet, with: 593 * sizeof(packet without AH) < mtu < sizeof(packet with AH) 594 */ 595 if (sab && ip->ip_p != IPPROTO_AH && (flags & IP_FORWARDING) == 0) 596 ip->ip_off &= ~IP_DF; 597 #endif /*IPSEC*/ 598 if (ip->ip_off & IP_DF) { 599 if (flags & IP_RETURNMTU) 600 *mtu_p = mtu; 601 error = EMSGSIZE; 602 ipstat.ips_cantfrag++; 603 goto bad; 604 } 605 len = (mtu - hlen) &~ 7; 606 if (len < 8) { 607 error = EMSGSIZE; 608 goto bad; 609 } 610 611 { 612 int mhlen, firstlen = len; 613 struct mbuf **mnext = &m->m_nextpkt; 614 int fragments = 0; 615 int s; 616 617 /* 618 * Loop through length of segment after first fragment, 619 * make new header and copy data of each part and link onto chain. 620 */ 621 m0 = m; 622 mhlen = sizeof (struct ip); 623 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 624 MGETHDR(m, M_DONTWAIT, MT_HEADER); 625 if (m == 0) { 626 error = ENOBUFS; 627 ipstat.ips_odropped++; 628 goto sendorfree; 629 } 630 *mnext = m; 631 mnext = &m->m_nextpkt; 632 m->m_data += max_linkhdr; 633 mhip = mtod(m, struct ip *); 634 *mhip = *ip; 635 /* we must inherit MCAST and BCAST flags */ 636 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 637 if (hlen > sizeof (struct ip)) { 638 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 639 mhip->ip_hl = mhlen >> 2; 640 } 641 m->m_len = mhlen; 642 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 643 if (ip->ip_off & IP_MF) 644 mhip->ip_off |= IP_MF; 645 if (off + len >= (u_int16_t)ip->ip_len) 646 len = (u_int16_t)ip->ip_len - off; 647 else 648 mhip->ip_off |= IP_MF; 649 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 650 m->m_next = m_copy(m0, off, len); 651 if (m->m_next == 0) { 652 error = ENOBUFS; /* ??? */ 653 ipstat.ips_odropped++; 654 goto sendorfree; 655 } 656 m->m_pkthdr.len = mhlen + len; 657 m->m_pkthdr.rcvif = (struct ifnet *)0; 658 HTONS(mhip->ip_off); 659 mhip->ip_sum = 0; 660 mhip->ip_sum = in_cksum(m, mhlen); 661 ipstat.ips_ofragments++; 662 fragments++; 663 } 664 /* 665 * Update first fragment by trimming what's been copied out 666 * and updating header, then send each fragment (in order). 667 */ 668 m = m0; 669 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 670 m->m_pkthdr.len = hlen + firstlen; 671 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 672 ip->ip_off |= IP_MF; 673 HTONS(ip->ip_off); 674 ip->ip_sum = 0; 675 ip->ip_sum = in_cksum(m, hlen); 676 sendorfree: 677 /* 678 * If there is no room for all the fragments, don't queue 679 * any of them. 680 */ 681 s = splimp(); 682 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 683 error = ENOBUFS; 684 splx(s); 685 for (m = m0; m; m = m0) { 686 m0 = m->m_nextpkt; 687 m->m_nextpkt = 0; 688 if (error == 0) { 689 #if IFA_STATS 690 /* 691 * search for the source address structure to 692 * maintain output statistics. 693 */ 694 bzero((caddr_t*) &src, sizeof(src)); 695 src.sin_family = AF_INET; 696 src.sin_addr.s_addr = ip->ip_src.s_addr; 697 src.sin_len = sizeof(src); 698 ia = ifatoia(ifa_ifwithladdr(sintosa(&src))); 699 if (ia) { 700 ia->ia_ifa.ifa_data.ifad_outbytes += 701 ntohs(ip->ip_len); 702 } 703 #endif 704 error = (*ifp->if_output)(ifp, m, sintosa(dst), 705 ro->ro_rt); 706 } else 707 m_freem(m); 708 } 709 710 if (error == 0) 711 ipstat.ips_fragmented++; 712 } 713 done: 714 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 715 RTFREE(ro->ro_rt); 716 ro->ro_rt = 0; 717 } 718 719 #ifdef IPSEC 720 if (sp != NULL) { 721 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 722 printf("DP ip_output call free SP:%p\n", sp)); 723 key_freesp(sp); 724 } 725 #endif /* IPSEC */ 726 727 return (error); 728 bad: 729 m_freem(m); 730 goto done; 731 } 732 733 /* 734 * Determine the maximum length of the options to be inserted; 735 * we would far rather allocate too much space rather than too little. 736 */ 737 738 u_int 739 ip_optlen(inp) 740 struct inpcb *inp; 741 { 742 struct mbuf *m = inp->inp_options; 743 744 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 745 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 746 else 747 return 0; 748 } 749 750 751 /* 752 * Insert IP options into preformed packet. 753 * Adjust IP destination as required for IP source routing, 754 * as indicated by a non-zero in_addr at the start of the options. 755 */ 756 static struct mbuf * 757 ip_insertoptions(m, opt, phlen) 758 struct mbuf *m; 759 struct mbuf *opt; 760 int *phlen; 761 { 762 struct ipoption *p = mtod(opt, struct ipoption *); 763 struct mbuf *n; 764 struct ip *ip = mtod(m, struct ip *); 765 unsigned optlen; 766 767 optlen = opt->m_len - sizeof(p->ipopt_dst); 768 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 769 return (m); /* XXX should fail */ 770 if (!in_nullhost(p->ipopt_dst)) 771 ip->ip_dst = p->ipopt_dst; 772 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 773 MGETHDR(n, M_DONTWAIT, MT_HEADER); 774 if (n == 0) 775 return (m); 776 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 777 m->m_len -= sizeof(struct ip); 778 m->m_data += sizeof(struct ip); 779 n->m_next = m; 780 m = n; 781 m->m_len = optlen + sizeof(struct ip); 782 m->m_data += max_linkhdr; 783 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 784 } else { 785 m->m_data -= optlen; 786 m->m_len += optlen; 787 m->m_pkthdr.len += optlen; 788 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 789 } 790 ip = mtod(m, struct ip *); 791 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 792 *phlen = sizeof(struct ip) + optlen; 793 ip->ip_len += optlen; 794 return (m); 795 } 796 797 /* 798 * Copy options from ip to jp, 799 * omitting those not copied during fragmentation. 800 */ 801 int 802 ip_optcopy(ip, jp) 803 struct ip *ip, *jp; 804 { 805 u_char *cp, *dp; 806 int opt, optlen, cnt; 807 808 cp = (u_char *)(ip + 1); 809 dp = (u_char *)(jp + 1); 810 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 811 for (; cnt > 0; cnt -= optlen, cp += optlen) { 812 opt = cp[0]; 813 if (opt == IPOPT_EOL) 814 break; 815 if (opt == IPOPT_NOP) { 816 /* Preserve for IP mcast tunnel's LSRR alignment. */ 817 *dp++ = IPOPT_NOP; 818 optlen = 1; 819 continue; 820 } 821 #ifdef DIAGNOSTIC 822 if (cnt < IPOPT_OLEN + sizeof(*cp)) 823 panic("malformed IPv4 option passed to ip_optcopy"); 824 #endif 825 optlen = cp[IPOPT_OLEN]; 826 #ifdef DIAGNOSTIC 827 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 828 panic("malformed IPv4 option passed to ip_optcopy"); 829 #endif 830 /* bogus lengths should have been caught by ip_dooptions */ 831 if (optlen > cnt) 832 optlen = cnt; 833 if (IPOPT_COPIED(opt)) { 834 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 835 dp += optlen; 836 } 837 } 838 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 839 *dp++ = IPOPT_EOL; 840 return (optlen); 841 } 842 843 /* 844 * IP socket option processing. 845 */ 846 int 847 ip_ctloutput(op, so, level, optname, mp) 848 int op; 849 struct socket *so; 850 int level, optname; 851 struct mbuf **mp; 852 { 853 struct inpcb *inp = sotoinpcb(so); 854 struct mbuf *m = *mp; 855 int optval = 0; 856 int error = 0; 857 #ifdef IPSEC 858 #ifdef __NetBSD__ 859 struct proc *p = curproc; /*XXX*/ 860 #endif 861 #endif 862 863 if (level != IPPROTO_IP) { 864 error = EINVAL; 865 if (op == PRCO_SETOPT && *mp) 866 (void) m_free(*mp); 867 } else switch (op) { 868 869 case PRCO_SETOPT: 870 switch (optname) { 871 case IP_OPTIONS: 872 #ifdef notyet 873 case IP_RETOPTS: 874 return (ip_pcbopts(optname, &inp->inp_options, m)); 875 #else 876 return (ip_pcbopts(&inp->inp_options, m)); 877 #endif 878 879 case IP_TOS: 880 case IP_TTL: 881 case IP_RECVOPTS: 882 case IP_RECVRETOPTS: 883 case IP_RECVDSTADDR: 884 case IP_RECVIF: 885 if (m == NULL || m->m_len != sizeof(int)) 886 error = EINVAL; 887 else { 888 optval = *mtod(m, int *); 889 switch (optname) { 890 891 case IP_TOS: 892 inp->inp_ip.ip_tos = optval; 893 break; 894 895 case IP_TTL: 896 inp->inp_ip.ip_ttl = optval; 897 break; 898 #define OPTSET(bit) \ 899 if (optval) \ 900 inp->inp_flags |= bit; \ 901 else \ 902 inp->inp_flags &= ~bit; 903 904 case IP_RECVOPTS: 905 OPTSET(INP_RECVOPTS); 906 break; 907 908 case IP_RECVRETOPTS: 909 OPTSET(INP_RECVRETOPTS); 910 break; 911 912 case IP_RECVDSTADDR: 913 OPTSET(INP_RECVDSTADDR); 914 break; 915 916 case IP_RECVIF: 917 OPTSET(INP_RECVIF); 918 break; 919 } 920 } 921 break; 922 #undef OPTSET 923 924 case IP_MULTICAST_IF: 925 case IP_MULTICAST_TTL: 926 case IP_MULTICAST_LOOP: 927 case IP_ADD_MEMBERSHIP: 928 case IP_DROP_MEMBERSHIP: 929 error = ip_setmoptions(optname, &inp->inp_moptions, m); 930 break; 931 932 case IP_PORTRANGE: 933 if (m == 0 || m->m_len != sizeof(int)) 934 error = EINVAL; 935 else { 936 optval = *mtod(m, int *); 937 938 switch (optval) { 939 940 case IP_PORTRANGE_DEFAULT: 941 case IP_PORTRANGE_HIGH: 942 inp->inp_flags &= ~(INP_LOWPORT); 943 break; 944 945 case IP_PORTRANGE_LOW: 946 inp->inp_flags |= INP_LOWPORT; 947 break; 948 949 default: 950 error = EINVAL; 951 break; 952 } 953 } 954 break; 955 956 #ifdef IPSEC 957 case IP_IPSEC_POLICY: 958 { 959 caddr_t req = NULL; 960 size_t len = 0; 961 int priv = 0; 962 963 #ifdef __NetBSD__ 964 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 965 priv = 0; 966 else 967 priv = 1; 968 #else 969 priv = (in6p->in6p_socket->so_state & SS_PRIV); 970 #endif 971 if (m) { 972 req = mtod(m, caddr_t); 973 len = m->m_len; 974 } 975 error = ipsec4_set_policy(inp, optname, req, len, priv); 976 break; 977 } 978 #endif /*IPSEC*/ 979 980 default: 981 error = ENOPROTOOPT; 982 break; 983 } 984 if (m) 985 (void)m_free(m); 986 break; 987 988 case PRCO_GETOPT: 989 switch (optname) { 990 case IP_OPTIONS: 991 case IP_RETOPTS: 992 *mp = m = m_get(M_WAIT, MT_SOOPTS); 993 if (inp->inp_options) { 994 m->m_len = inp->inp_options->m_len; 995 bcopy(mtod(inp->inp_options, caddr_t), 996 mtod(m, caddr_t), (unsigned)m->m_len); 997 } else 998 m->m_len = 0; 999 break; 1000 1001 case IP_TOS: 1002 case IP_TTL: 1003 case IP_RECVOPTS: 1004 case IP_RECVRETOPTS: 1005 case IP_RECVDSTADDR: 1006 case IP_RECVIF: 1007 case IP_ERRORMTU: 1008 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1009 m->m_len = sizeof(int); 1010 switch (optname) { 1011 1012 case IP_TOS: 1013 optval = inp->inp_ip.ip_tos; 1014 break; 1015 1016 case IP_TTL: 1017 optval = inp->inp_ip.ip_ttl; 1018 break; 1019 1020 case IP_ERRORMTU: 1021 optval = inp->inp_errormtu; 1022 break; 1023 1024 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1025 1026 case IP_RECVOPTS: 1027 optval = OPTBIT(INP_RECVOPTS); 1028 break; 1029 1030 case IP_RECVRETOPTS: 1031 optval = OPTBIT(INP_RECVRETOPTS); 1032 break; 1033 1034 case IP_RECVDSTADDR: 1035 optval = OPTBIT(INP_RECVDSTADDR); 1036 break; 1037 1038 case IP_RECVIF: 1039 optval = OPTBIT(INP_RECVIF); 1040 break; 1041 } 1042 *mtod(m, int *) = optval; 1043 break; 1044 1045 #ifdef IPSEC 1046 case IP_IPSEC_POLICY: 1047 { 1048 caddr_t req = NULL; 1049 size_t len; 1050 1051 if (m) { 1052 req = mtod(m, caddr_t); 1053 len = m->m_len; 1054 } 1055 error = ipsec4_get_policy(inp, req, len, mp); 1056 break; 1057 } 1058 #endif /*IPSEC*/ 1059 1060 case IP_MULTICAST_IF: 1061 case IP_MULTICAST_TTL: 1062 case IP_MULTICAST_LOOP: 1063 case IP_ADD_MEMBERSHIP: 1064 case IP_DROP_MEMBERSHIP: 1065 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1066 break; 1067 1068 case IP_PORTRANGE: 1069 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1070 m->m_len = sizeof(int); 1071 1072 if (inp->inp_flags & INP_LOWPORT) 1073 optval = IP_PORTRANGE_LOW; 1074 else 1075 optval = IP_PORTRANGE_DEFAULT; 1076 1077 *mtod(m, int *) = optval; 1078 break; 1079 1080 default: 1081 error = ENOPROTOOPT; 1082 break; 1083 } 1084 break; 1085 } 1086 return (error); 1087 } 1088 1089 /* 1090 * Set up IP options in pcb for insertion in output packets. 1091 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1092 * with destination address if source routed. 1093 */ 1094 int 1095 #ifdef notyet 1096 ip_pcbopts(optname, pcbopt, m) 1097 int optname; 1098 #else 1099 ip_pcbopts(pcbopt, m) 1100 #endif 1101 struct mbuf **pcbopt; 1102 struct mbuf *m; 1103 { 1104 int cnt, optlen; 1105 u_char *cp; 1106 u_char opt; 1107 1108 /* turn off any old options */ 1109 if (*pcbopt) 1110 (void)m_free(*pcbopt); 1111 *pcbopt = 0; 1112 if (m == (struct mbuf *)0 || m->m_len == 0) { 1113 /* 1114 * Only turning off any previous options. 1115 */ 1116 if (m) 1117 (void)m_free(m); 1118 return (0); 1119 } 1120 1121 #ifndef vax 1122 if (m->m_len % sizeof(int32_t)) 1123 goto bad; 1124 #endif 1125 /* 1126 * IP first-hop destination address will be stored before 1127 * actual options; move other options back 1128 * and clear it when none present. 1129 */ 1130 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1131 goto bad; 1132 cnt = m->m_len; 1133 m->m_len += sizeof(struct in_addr); 1134 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1135 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1136 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1137 1138 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1139 opt = cp[IPOPT_OPTVAL]; 1140 if (opt == IPOPT_EOL) 1141 break; 1142 if (opt == IPOPT_NOP) 1143 optlen = 1; 1144 else { 1145 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1146 goto bad; 1147 optlen = cp[IPOPT_OLEN]; 1148 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1149 goto bad; 1150 } 1151 switch (opt) { 1152 1153 default: 1154 break; 1155 1156 case IPOPT_LSRR: 1157 case IPOPT_SSRR: 1158 /* 1159 * user process specifies route as: 1160 * ->A->B->C->D 1161 * D must be our final destination (but we can't 1162 * check that since we may not have connected yet). 1163 * A is first hop destination, which doesn't appear in 1164 * actual IP option, but is stored before the options. 1165 */ 1166 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1167 goto bad; 1168 m->m_len -= sizeof(struct in_addr); 1169 cnt -= sizeof(struct in_addr); 1170 optlen -= sizeof(struct in_addr); 1171 cp[IPOPT_OLEN] = optlen; 1172 /* 1173 * Move first hop before start of options. 1174 */ 1175 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1176 sizeof(struct in_addr)); 1177 /* 1178 * Then copy rest of options back 1179 * to close up the deleted entry. 1180 */ 1181 memmove(&cp[IPOPT_OFFSET+1], 1182 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1183 (unsigned)cnt + sizeof(struct in_addr)); 1184 break; 1185 } 1186 } 1187 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1188 goto bad; 1189 *pcbopt = m; 1190 return (0); 1191 1192 bad: 1193 (void)m_free(m); 1194 return (EINVAL); 1195 } 1196 1197 /* 1198 * Set the IP multicast options in response to user setsockopt(). 1199 */ 1200 int 1201 ip_setmoptions(optname, imop, m) 1202 int optname; 1203 struct ip_moptions **imop; 1204 struct mbuf *m; 1205 { 1206 int error = 0; 1207 u_char loop; 1208 int i; 1209 struct in_addr addr; 1210 struct ip_mreq *mreq; 1211 struct ifnet *ifp; 1212 struct ip_moptions *imo = *imop; 1213 struct route ro; 1214 struct sockaddr_in *dst; 1215 1216 if (imo == NULL) { 1217 /* 1218 * No multicast option buffer attached to the pcb; 1219 * allocate one and initialize to default values. 1220 */ 1221 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1222 M_WAITOK); 1223 1224 if (imo == NULL) 1225 return (ENOBUFS); 1226 *imop = imo; 1227 imo->imo_multicast_ifp = NULL; 1228 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1229 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1230 imo->imo_num_memberships = 0; 1231 } 1232 1233 switch (optname) { 1234 1235 case IP_MULTICAST_IF: 1236 /* 1237 * Select the interface for outgoing multicast packets. 1238 */ 1239 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1240 error = EINVAL; 1241 break; 1242 } 1243 addr = *(mtod(m, struct in_addr *)); 1244 /* 1245 * INADDR_ANY is used to remove a previous selection. 1246 * When no interface is selected, a default one is 1247 * chosen every time a multicast packet is sent. 1248 */ 1249 if (in_nullhost(addr)) { 1250 imo->imo_multicast_ifp = NULL; 1251 break; 1252 } 1253 /* 1254 * The selected interface is identified by its local 1255 * IP address. Find the interface and confirm that 1256 * it supports multicasting. 1257 */ 1258 INADDR_TO_IFP(addr, ifp); 1259 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1260 error = EADDRNOTAVAIL; 1261 break; 1262 } 1263 imo->imo_multicast_ifp = ifp; 1264 break; 1265 1266 case IP_MULTICAST_TTL: 1267 /* 1268 * Set the IP time-to-live for outgoing multicast packets. 1269 */ 1270 if (m == NULL || m->m_len != 1) { 1271 error = EINVAL; 1272 break; 1273 } 1274 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1275 break; 1276 1277 case IP_MULTICAST_LOOP: 1278 /* 1279 * Set the loopback flag for outgoing multicast packets. 1280 * Must be zero or one. 1281 */ 1282 if (m == NULL || m->m_len != 1 || 1283 (loop = *(mtod(m, u_char *))) > 1) { 1284 error = EINVAL; 1285 break; 1286 } 1287 imo->imo_multicast_loop = loop; 1288 break; 1289 1290 case IP_ADD_MEMBERSHIP: 1291 /* 1292 * Add a multicast group membership. 1293 * Group must be a valid IP multicast address. 1294 */ 1295 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1296 error = EINVAL; 1297 break; 1298 } 1299 mreq = mtod(m, struct ip_mreq *); 1300 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1301 error = EINVAL; 1302 break; 1303 } 1304 /* 1305 * If no interface address was provided, use the interface of 1306 * the route to the given multicast address. 1307 */ 1308 if (in_nullhost(mreq->imr_interface)) { 1309 bzero((caddr_t)&ro, sizeof(ro)); 1310 ro.ro_rt = NULL; 1311 dst = satosin(&ro.ro_dst); 1312 dst->sin_len = sizeof(*dst); 1313 dst->sin_family = AF_INET; 1314 dst->sin_addr = mreq->imr_multiaddr; 1315 rtalloc(&ro); 1316 if (ro.ro_rt == NULL) { 1317 error = EADDRNOTAVAIL; 1318 break; 1319 } 1320 ifp = ro.ro_rt->rt_ifp; 1321 rtfree(ro.ro_rt); 1322 } else { 1323 INADDR_TO_IFP(mreq->imr_interface, ifp); 1324 } 1325 /* 1326 * See if we found an interface, and confirm that it 1327 * supports multicast. 1328 */ 1329 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1330 error = EADDRNOTAVAIL; 1331 break; 1332 } 1333 /* 1334 * See if the membership already exists or if all the 1335 * membership slots are full. 1336 */ 1337 for (i = 0; i < imo->imo_num_memberships; ++i) { 1338 if (imo->imo_membership[i]->inm_ifp == ifp && 1339 in_hosteq(imo->imo_membership[i]->inm_addr, 1340 mreq->imr_multiaddr)) 1341 break; 1342 } 1343 if (i < imo->imo_num_memberships) { 1344 error = EADDRINUSE; 1345 break; 1346 } 1347 if (i == IP_MAX_MEMBERSHIPS) { 1348 error = ETOOMANYREFS; 1349 break; 1350 } 1351 /* 1352 * Everything looks good; add a new record to the multicast 1353 * address list for the given interface. 1354 */ 1355 if ((imo->imo_membership[i] = 1356 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1357 error = ENOBUFS; 1358 break; 1359 } 1360 ++imo->imo_num_memberships; 1361 break; 1362 1363 case IP_DROP_MEMBERSHIP: 1364 /* 1365 * Drop a multicast group membership. 1366 * Group must be a valid IP multicast address. 1367 */ 1368 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1369 error = EINVAL; 1370 break; 1371 } 1372 mreq = mtod(m, struct ip_mreq *); 1373 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1374 error = EINVAL; 1375 break; 1376 } 1377 /* 1378 * If an interface address was specified, get a pointer 1379 * to its ifnet structure. 1380 */ 1381 if (in_nullhost(mreq->imr_interface)) 1382 ifp = NULL; 1383 else { 1384 INADDR_TO_IFP(mreq->imr_interface, ifp); 1385 if (ifp == NULL) { 1386 error = EADDRNOTAVAIL; 1387 break; 1388 } 1389 } 1390 /* 1391 * Find the membership in the membership array. 1392 */ 1393 for (i = 0; i < imo->imo_num_memberships; ++i) { 1394 if ((ifp == NULL || 1395 imo->imo_membership[i]->inm_ifp == ifp) && 1396 in_hosteq(imo->imo_membership[i]->inm_addr, 1397 mreq->imr_multiaddr)) 1398 break; 1399 } 1400 if (i == imo->imo_num_memberships) { 1401 error = EADDRNOTAVAIL; 1402 break; 1403 } 1404 /* 1405 * Give up the multicast address record to which the 1406 * membership points. 1407 */ 1408 in_delmulti(imo->imo_membership[i]); 1409 /* 1410 * Remove the gap in the membership array. 1411 */ 1412 for (++i; i < imo->imo_num_memberships; ++i) 1413 imo->imo_membership[i-1] = imo->imo_membership[i]; 1414 --imo->imo_num_memberships; 1415 break; 1416 1417 default: 1418 error = EOPNOTSUPP; 1419 break; 1420 } 1421 1422 /* 1423 * If all options have default values, no need to keep the mbuf. 1424 */ 1425 if (imo->imo_multicast_ifp == NULL && 1426 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1427 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1428 imo->imo_num_memberships == 0) { 1429 free(*imop, M_IPMOPTS); 1430 *imop = NULL; 1431 } 1432 1433 return (error); 1434 } 1435 1436 /* 1437 * Return the IP multicast options in response to user getsockopt(). 1438 */ 1439 int 1440 ip_getmoptions(optname, imo, mp) 1441 int optname; 1442 struct ip_moptions *imo; 1443 struct mbuf **mp; 1444 { 1445 u_char *ttl; 1446 u_char *loop; 1447 struct in_addr *addr; 1448 struct in_ifaddr *ia; 1449 1450 *mp = m_get(M_WAIT, MT_SOOPTS); 1451 1452 switch (optname) { 1453 1454 case IP_MULTICAST_IF: 1455 addr = mtod(*mp, struct in_addr *); 1456 (*mp)->m_len = sizeof(struct in_addr); 1457 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1458 *addr = zeroin_addr; 1459 else { 1460 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1461 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1462 } 1463 return (0); 1464 1465 case IP_MULTICAST_TTL: 1466 ttl = mtod(*mp, u_char *); 1467 (*mp)->m_len = 1; 1468 *ttl = imo ? imo->imo_multicast_ttl 1469 : IP_DEFAULT_MULTICAST_TTL; 1470 return (0); 1471 1472 case IP_MULTICAST_LOOP: 1473 loop = mtod(*mp, u_char *); 1474 (*mp)->m_len = 1; 1475 *loop = imo ? imo->imo_multicast_loop 1476 : IP_DEFAULT_MULTICAST_LOOP; 1477 return (0); 1478 1479 default: 1480 return (EOPNOTSUPP); 1481 } 1482 } 1483 1484 /* 1485 * Discard the IP multicast options. 1486 */ 1487 void 1488 ip_freemoptions(imo) 1489 struct ip_moptions *imo; 1490 { 1491 int i; 1492 1493 if (imo != NULL) { 1494 for (i = 0; i < imo->imo_num_memberships; ++i) 1495 in_delmulti(imo->imo_membership[i]); 1496 free(imo, M_IPMOPTS); 1497 } 1498 } 1499 1500 /* 1501 * Routine called from ip_output() to loop back a copy of an IP multicast 1502 * packet to the input queue of a specified interface. Note that this 1503 * calls the output routine of the loopback "driver", but with an interface 1504 * pointer that might NOT be &loif -- easier than replicating that code here. 1505 */ 1506 static void 1507 ip_mloopback(ifp, m, dst) 1508 struct ifnet *ifp; 1509 struct mbuf *m; 1510 struct sockaddr_in *dst; 1511 { 1512 struct ip *ip; 1513 struct mbuf *copym; 1514 1515 copym = m_copy(m, 0, M_COPYALL); 1516 if (copym != NULL 1517 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1518 copym = m_pullup(copym, sizeof(struct ip)); 1519 if (copym != NULL) { 1520 /* 1521 * We don't bother to fragment if the IP length is greater 1522 * than the interface's MTU. Can this possibly matter? 1523 */ 1524 ip = mtod(copym, struct ip *); 1525 HTONS(ip->ip_len); 1526 HTONS(ip->ip_off); 1527 ip->ip_sum = 0; 1528 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1529 (void) looutput(ifp, copym, sintosa(dst), NULL); 1530 } 1531 } 1532