1 /* $NetBSD: ip_output.c,v 1.90 2001/11/21 06:28:08 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 <sys/cdefs.h> 105 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.90 2001/11/21 06:28:08 itojun Exp $"); 106 107 #include "opt_pfil_hooks.h" 108 #include "opt_ipsec.h" 109 #include "opt_mrouting.h" 110 111 #include <sys/param.h> 112 #include <sys/malloc.h> 113 #include <sys/mbuf.h> 114 #include <sys/errno.h> 115 #include <sys/protosw.h> 116 #include <sys/socket.h> 117 #include <sys/socketvar.h> 118 #include <sys/systm.h> 119 #include <sys/proc.h> 120 121 #include <net/if.h> 122 #include <net/route.h> 123 #include <net/pfil.h> 124 125 #include <netinet/in.h> 126 #include <netinet/in_systm.h> 127 #include <netinet/ip.h> 128 #include <netinet/in_pcb.h> 129 #include <netinet/in_var.h> 130 #include <netinet/ip_var.h> 131 132 #ifdef MROUTING 133 #include <netinet/ip_mroute.h> 134 #endif 135 136 #include <machine/stdarg.h> 137 138 #ifdef IPSEC 139 #include <netinet6/ipsec.h> 140 #include <netkey/key.h> 141 #include <netkey/key_debug.h> 142 #endif /*IPSEC*/ 143 144 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 145 static struct ifnet *ip_multicast_if __P((struct in_addr *, int *)); 146 static void ip_mloopback 147 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); 148 149 #ifdef PFIL_HOOKS 150 extern struct pfil_head inet_pfil_hook; /* XXX */ 151 #endif 152 153 /* 154 * IP output. The packet in mbuf chain m contains a skeletal IP 155 * header (with len, off, ttl, proto, tos, src, dst). 156 * The mbuf chain containing the packet will be freed. 157 * The mbuf opt, if present, will not be freed. 158 */ 159 int 160 #if __STDC__ 161 ip_output(struct mbuf *m0, ...) 162 #else 163 ip_output(m0, va_alist) 164 struct mbuf *m0; 165 va_dcl 166 #endif 167 { 168 struct ip *ip, *mhip; 169 struct ifnet *ifp; 170 struct mbuf *m = m0; 171 int hlen = sizeof (struct ip); 172 int len, off, error = 0; 173 struct route iproute; 174 struct sockaddr_in *dst; 175 struct in_ifaddr *ia; 176 struct mbuf *opt; 177 struct route *ro; 178 int flags, sw_csum; 179 int *mtu_p; 180 int mtu; 181 struct ip_moptions *imo; 182 va_list ap; 183 #ifdef IPSEC 184 struct socket *so; 185 struct secpolicy *sp = NULL; 186 #endif /*IPSEC*/ 187 u_int16_t ip_len; 188 189 va_start(ap, m0); 190 opt = va_arg(ap, struct mbuf *); 191 ro = va_arg(ap, struct route *); 192 flags = va_arg(ap, int); 193 imo = va_arg(ap, struct ip_moptions *); 194 if (flags & IP_RETURNMTU) 195 mtu_p = va_arg(ap, int *); 196 else 197 mtu_p = NULL; 198 va_end(ap); 199 200 #ifdef IPSEC 201 so = ipsec_getsocket(m); 202 (void)ipsec_setsocket(m, NULL); 203 #endif /*IPSEC*/ 204 205 #ifdef DIAGNOSTIC 206 if ((m->m_flags & M_PKTHDR) == 0) 207 panic("ip_output no HDR"); 208 #endif 209 if (opt) { 210 m = ip_insertoptions(m, opt, &len); 211 hlen = len; 212 } 213 ip = mtod(m, struct ip *); 214 /* 215 * Fill in IP header. 216 */ 217 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 218 ip->ip_v = IPVERSION; 219 ip->ip_off = 0; 220 ip->ip_id = htons(ip_id++); 221 ip->ip_hl = hlen >> 2; 222 ipstat.ips_localout++; 223 } else { 224 hlen = ip->ip_hl << 2; 225 } 226 /* 227 * Route packet. 228 */ 229 if (ro == 0) { 230 ro = &iproute; 231 bzero((caddr_t)ro, sizeof (*ro)); 232 } 233 dst = satosin(&ro->ro_dst); 234 /* 235 * If there is a cached route, 236 * check that it is to the same destination 237 * and is still up. If not, free it and try again. 238 */ 239 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 240 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 241 RTFREE(ro->ro_rt); 242 ro->ro_rt = (struct rtentry *)0; 243 } 244 if (ro->ro_rt == 0) { 245 dst->sin_family = AF_INET; 246 dst->sin_len = sizeof(*dst); 247 dst->sin_addr = ip->ip_dst; 248 } 249 /* 250 * If routing to interface only, 251 * short circuit routing lookup. 252 */ 253 if (flags & IP_ROUTETOIF) { 254 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 255 ipstat.ips_noroute++; 256 error = ENETUNREACH; 257 goto bad; 258 } 259 ifp = ia->ia_ifp; 260 mtu = ifp->if_mtu; 261 ip->ip_ttl = 1; 262 } else { 263 if (ro->ro_rt == 0) 264 rtalloc(ro); 265 if (ro->ro_rt == 0) { 266 ipstat.ips_noroute++; 267 error = EHOSTUNREACH; 268 goto bad; 269 } 270 ia = ifatoia(ro->ro_rt->rt_ifa); 271 ifp = ro->ro_rt->rt_ifp; 272 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 273 mtu = ifp->if_mtu; 274 ro->ro_rt->rt_use++; 275 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 276 dst = satosin(ro->ro_rt->rt_gateway); 277 } 278 if (IN_MULTICAST(ip->ip_dst.s_addr) || 279 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 280 struct in_multi *inm; 281 282 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 283 M_BCAST : M_MCAST; 284 /* 285 * IP destination address is multicast. Make sure "dst" 286 * still points to the address in "ro". (It may have been 287 * changed to point to a gateway address, above.) 288 */ 289 dst = satosin(&ro->ro_dst); 290 /* 291 * See if the caller provided any multicast options 292 */ 293 if (imo != NULL) { 294 ip->ip_ttl = imo->imo_multicast_ttl; 295 if (imo->imo_multicast_ifp != NULL) { 296 ifp = imo->imo_multicast_ifp; 297 mtu = ifp->if_mtu; 298 } 299 } else 300 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 301 /* 302 * Confirm that the outgoing interface supports multicast. 303 */ 304 if (((m->m_flags & M_MCAST) && 305 (ifp->if_flags & IFF_MULTICAST) == 0) || 306 ((m->m_flags & M_BCAST) && 307 (ifp->if_flags & IFF_BROADCAST) == 0)) { 308 ipstat.ips_noroute++; 309 error = ENETUNREACH; 310 goto bad; 311 } 312 /* 313 * If source address not specified yet, use an address 314 * of outgoing interface. 315 */ 316 if (in_nullhost(ip->ip_src)) { 317 struct in_ifaddr *ia; 318 319 IFP_TO_IA(ifp, ia); 320 ip->ip_src = ia->ia_addr.sin_addr; 321 } 322 323 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 324 if (inm != NULL && 325 (imo == NULL || imo->imo_multicast_loop)) { 326 /* 327 * If we belong to the destination multicast group 328 * on the outgoing interface, and the caller did not 329 * forbid loopback, loop back a copy. 330 */ 331 ip_mloopback(ifp, m, dst); 332 } 333 #ifdef MROUTING 334 else { 335 /* 336 * If we are acting as a multicast router, perform 337 * multicast forwarding as if the packet had just 338 * arrived on the interface to which we are about 339 * to send. The multicast forwarding function 340 * recursively calls this function, using the 341 * IP_FORWARDING flag to prevent infinite recursion. 342 * 343 * Multicasts that are looped back by ip_mloopback(), 344 * above, will be forwarded by the ip_input() routine, 345 * if necessary. 346 */ 347 extern struct socket *ip_mrouter; 348 349 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 350 if (ip_mforward(m, ifp) != 0) { 351 m_freem(m); 352 goto done; 353 } 354 } 355 } 356 #endif 357 /* 358 * Multicasts with a time-to-live of zero may be looped- 359 * back, above, but must not be transmitted on a network. 360 * Also, multicasts addressed to the loopback interface 361 * are not sent -- the above call to ip_mloopback() will 362 * loop back a copy if this host actually belongs to the 363 * destination group on the loopback interface. 364 */ 365 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 366 m_freem(m); 367 goto done; 368 } 369 370 goto sendit; 371 } 372 #ifndef notdef 373 /* 374 * If source address not specified yet, use address 375 * of outgoing interface. 376 */ 377 if (in_nullhost(ip->ip_src)) 378 ip->ip_src = ia->ia_addr.sin_addr; 379 #endif 380 381 /* 382 * packets with Class-D address as source are not valid per 383 * RFC 1112 384 */ 385 if (IN_MULTICAST(ip->ip_src.s_addr)) { 386 ipstat.ips_odropped++; 387 error = EADDRNOTAVAIL; 388 goto bad; 389 } 390 391 /* 392 * Look for broadcast address and 393 * and verify user is allowed to send 394 * such a packet. 395 */ 396 if (in_broadcast(dst->sin_addr, ifp)) { 397 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 398 error = EADDRNOTAVAIL; 399 goto bad; 400 } 401 if ((flags & IP_ALLOWBROADCAST) == 0) { 402 error = EACCES; 403 goto bad; 404 } 405 /* don't allow broadcast messages to be fragmented */ 406 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 407 error = EMSGSIZE; 408 goto bad; 409 } 410 m->m_flags |= M_BCAST; 411 } else 412 m->m_flags &= ~M_BCAST; 413 414 sendit: 415 /* 416 * If we're doing Path MTU Discovery, we need to set DF unless 417 * the route's MTU is locked. 418 */ 419 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 420 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 421 ip->ip_off |= IP_DF; 422 423 /* 424 * Remember the current ip_len and ip_off, and swap them into 425 * network order. 426 */ 427 ip_len = ip->ip_len; 428 429 HTONS(ip->ip_len); 430 HTONS(ip->ip_off); 431 432 #ifdef IPSEC 433 /* get SP for this packet */ 434 if (so == NULL) 435 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 436 else 437 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 438 439 if (sp == NULL) { 440 ipsecstat.out_inval++; 441 goto bad; 442 } 443 444 error = 0; 445 446 /* check policy */ 447 switch (sp->policy) { 448 case IPSEC_POLICY_DISCARD: 449 /* 450 * This packet is just discarded. 451 */ 452 ipsecstat.out_polvio++; 453 goto bad; 454 455 case IPSEC_POLICY_BYPASS: 456 case IPSEC_POLICY_NONE: 457 /* no need to do IPsec. */ 458 goto skip_ipsec; 459 460 case IPSEC_POLICY_IPSEC: 461 if (sp->req == NULL) { 462 /* XXX should be panic ? */ 463 printf("ip_output: No IPsec request specified.\n"); 464 error = EINVAL; 465 goto bad; 466 } 467 break; 468 469 case IPSEC_POLICY_ENTRUST: 470 default: 471 printf("ip_output: Invalid policy found. %d\n", sp->policy); 472 } 473 474 /* 475 * ipsec4_output() expects ip_len and ip_off in network 476 * order. They have been set to network order above. 477 */ 478 479 { 480 struct ipsec_output_state state; 481 bzero(&state, sizeof(state)); 482 state.m = m; 483 if (flags & IP_ROUTETOIF) { 484 state.ro = &iproute; 485 bzero(&iproute, sizeof(iproute)); 486 } else 487 state.ro = ro; 488 state.dst = (struct sockaddr *)dst; 489 490 /* 491 * We can't defer the checksum of payload data if 492 * we're about to encrypt/authenticate it. 493 * 494 * XXX When we support crypto offloading functions of 495 * XXX network interfaces, we need to reconsider this, 496 * XXX since it's likely that they'll support checksumming, 497 * XXX as well. 498 */ 499 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 500 in_delayed_cksum(m); 501 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 502 } 503 504 error = ipsec4_output(&state, sp, flags); 505 506 m = state.m; 507 if (flags & IP_ROUTETOIF) { 508 /* 509 * if we have tunnel mode SA, we may need to ignore 510 * IP_ROUTETOIF. 511 */ 512 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 513 flags &= ~IP_ROUTETOIF; 514 ro = state.ro; 515 } 516 } else 517 ro = state.ro; 518 dst = (struct sockaddr_in *)state.dst; 519 if (error) { 520 /* mbuf is already reclaimed in ipsec4_output. */ 521 m0 = NULL; 522 switch (error) { 523 case EHOSTUNREACH: 524 case ENETUNREACH: 525 case EMSGSIZE: 526 case ENOBUFS: 527 case ENOMEM: 528 break; 529 default: 530 printf("ip4_output (ipsec): error code %d\n", error); 531 /*fall through*/ 532 case ENOENT: 533 /* don't show these error codes to the user */ 534 error = 0; 535 break; 536 } 537 goto bad; 538 } 539 540 /* 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 if (state.encap) 559 ifp = ro->ro_rt->rt_ifp; 560 } 561 } 562 563 skip_ipsec: 564 #endif /*IPSEC*/ 565 566 #ifdef PFIL_HOOKS 567 /* 568 * Run through list of hooks for output packets. 569 */ 570 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 571 PFIL_OUT)) != 0) 572 goto done; 573 if (m == NULL) 574 goto done; 575 576 ip = mtod(m, struct ip *); 577 #endif /* PFIL_HOOKS */ 578 579 /* 580 * If small enough for mtu of path, can just send directly. 581 */ 582 if (ip_len <= mtu) { 583 #if IFA_STATS 584 /* 585 * search for the source address structure to 586 * maintain output statistics. 587 */ 588 INADDR_TO_IA(ip->ip_src, ia); 589 if (ia) 590 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 591 #endif 592 /* 593 * Always initialize the sum to 0! Some HW assisted 594 * checksumming requires this. 595 */ 596 ip->ip_sum = 0; 597 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 598 599 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 600 601 /* 602 * Perform any checksums that the hardware can't do 603 * for us. 604 * 605 * XXX Does any hardware require the {th,uh}_sum 606 * XXX fields to be 0? 607 */ 608 if (sw_csum & M_CSUM_IPv4) 609 ip->ip_sum = in_cksum(m, hlen); 610 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 611 in_delayed_cksum(m); 612 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 613 } 614 m->m_pkthdr.csum_flags &= ifp->if_csum_flags_tx; 615 616 #ifdef IPSEC 617 /* clean ipsec history once it goes out of the node */ 618 ipsec_delaux(m); 619 #endif 620 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 621 goto done; 622 } 623 624 /* 625 * We can't use HW checksumming if we're about to 626 * to fragment the packet. 627 * 628 * XXX Some hardware can do this. 629 */ 630 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 631 in_delayed_cksum(m); 632 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 633 } 634 635 /* 636 * Too large for interface; fragment if possible. 637 * Must be able to put at least 8 bytes per fragment. 638 * 639 * Note we swap ip_len and ip_off into host order to make 640 * the logic below a little simpler. 641 */ 642 643 NTOHS(ip->ip_len); 644 NTOHS(ip->ip_off); 645 646 if (ip->ip_off & IP_DF) { 647 if (flags & IP_RETURNMTU) 648 *mtu_p = mtu; 649 error = EMSGSIZE; 650 ipstat.ips_cantfrag++; 651 goto bad; 652 } 653 len = (mtu - hlen) &~ 7; 654 if (len < 8) { 655 error = EMSGSIZE; 656 goto bad; 657 } 658 659 { 660 int mhlen, firstlen = len; 661 struct mbuf **mnext = &m->m_nextpkt; 662 int fragments = 0; 663 int s; 664 665 /* 666 * Loop through length of segment after first fragment, 667 * make new header and copy data of each part and link onto chain. 668 */ 669 m0 = m; 670 mhlen = sizeof (struct ip); 671 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 672 MGETHDR(m, M_DONTWAIT, MT_HEADER); 673 if (m == 0) { 674 error = ENOBUFS; 675 ipstat.ips_odropped++; 676 goto sendorfree; 677 } 678 *mnext = m; 679 mnext = &m->m_nextpkt; 680 m->m_data += max_linkhdr; 681 mhip = mtod(m, struct ip *); 682 *mhip = *ip; 683 /* we must inherit MCAST and BCAST flags */ 684 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 685 if (hlen > sizeof (struct ip)) { 686 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 687 mhip->ip_hl = mhlen >> 2; 688 } 689 m->m_len = mhlen; 690 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 691 if (ip->ip_off & IP_MF) 692 mhip->ip_off |= IP_MF; 693 if (off + len >= (u_int16_t)ip->ip_len) 694 len = (u_int16_t)ip->ip_len - off; 695 else 696 mhip->ip_off |= IP_MF; 697 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 698 m->m_next = m_copy(m0, off, len); 699 if (m->m_next == 0) { 700 error = ENOBUFS; /* ??? */ 701 ipstat.ips_odropped++; 702 goto sendorfree; 703 } 704 m->m_pkthdr.len = mhlen + len; 705 m->m_pkthdr.rcvif = (struct ifnet *)0; 706 HTONS(mhip->ip_off); 707 mhip->ip_sum = 0; 708 mhip->ip_sum = in_cksum(m, mhlen); 709 ipstat.ips_ofragments++; 710 fragments++; 711 } 712 /* 713 * Update first fragment by trimming what's been copied out 714 * and updating header, then send each fragment (in order). 715 */ 716 m = m0; 717 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 718 m->m_pkthdr.len = hlen + firstlen; 719 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 720 ip->ip_off |= IP_MF; 721 HTONS(ip->ip_off); 722 ip->ip_sum = 0; 723 ip->ip_sum = in_cksum(m, hlen); 724 sendorfree: 725 /* 726 * If there is no room for all the fragments, don't queue 727 * any of them. 728 */ 729 s = splnet(); 730 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 731 error = ENOBUFS; 732 splx(s); 733 for (m = m0; m; m = m0) { 734 m0 = m->m_nextpkt; 735 m->m_nextpkt = 0; 736 if (error == 0) { 737 #if IFA_STATS 738 /* 739 * search for the source address structure to 740 * maintain output statistics. 741 */ 742 INADDR_TO_IA(ip->ip_src, ia); 743 if (ia) { 744 ia->ia_ifa.ifa_data.ifad_outbytes += 745 ntohs(ip->ip_len); 746 } 747 #endif 748 #ifdef IPSEC 749 /* clean ipsec history once it goes out of the node */ 750 ipsec_delaux(m); 751 #endif 752 error = (*ifp->if_output)(ifp, m, sintosa(dst), 753 ro->ro_rt); 754 } else 755 m_freem(m); 756 } 757 758 if (error == 0) 759 ipstat.ips_fragmented++; 760 } 761 done: 762 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 763 RTFREE(ro->ro_rt); 764 ro->ro_rt = 0; 765 } 766 767 #ifdef IPSEC 768 if (sp != NULL) { 769 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 770 printf("DP ip_output call free SP:%p\n", sp)); 771 key_freesp(sp); 772 } 773 #endif /* IPSEC */ 774 775 return (error); 776 bad: 777 m_freem(m); 778 goto done; 779 } 780 781 /* 782 * Process a delayed payload checksum calculation. 783 */ 784 void 785 in_delayed_cksum(struct mbuf *m) 786 { 787 struct ip *ip; 788 u_int16_t csum, offset; 789 790 ip = mtod(m, struct ip *); 791 offset = ip->ip_hl << 2; 792 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 793 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 794 csum = 0xffff; 795 796 offset += m->m_pkthdr.csum_data; /* checksum offset */ 797 798 if ((offset + sizeof(u_int16_t)) > m->m_len) { 799 /* This happen when ip options were inserted 800 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 801 m->m_len, offset, ip->ip_p); 802 */ 803 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 804 } else 805 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 806 } 807 808 /* 809 * Determine the maximum length of the options to be inserted; 810 * we would far rather allocate too much space rather than too little. 811 */ 812 813 u_int 814 ip_optlen(inp) 815 struct inpcb *inp; 816 { 817 struct mbuf *m = inp->inp_options; 818 819 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 820 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 821 else 822 return 0; 823 } 824 825 826 /* 827 * Insert IP options into preformed packet. 828 * Adjust IP destination as required for IP source routing, 829 * as indicated by a non-zero in_addr at the start of the options. 830 */ 831 static struct mbuf * 832 ip_insertoptions(m, opt, phlen) 833 struct mbuf *m; 834 struct mbuf *opt; 835 int *phlen; 836 { 837 struct ipoption *p = mtod(opt, struct ipoption *); 838 struct mbuf *n; 839 struct ip *ip = mtod(m, struct ip *); 840 unsigned optlen; 841 842 optlen = opt->m_len - sizeof(p->ipopt_dst); 843 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 844 return (m); /* XXX should fail */ 845 if (!in_nullhost(p->ipopt_dst)) 846 ip->ip_dst = p->ipopt_dst; 847 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 848 MGETHDR(n, M_DONTWAIT, MT_HEADER); 849 if (n == 0) 850 return (m); 851 M_COPY_PKTHDR(n, m); 852 m->m_flags &= ~M_PKTHDR; 853 m->m_len -= sizeof(struct ip); 854 m->m_data += sizeof(struct ip); 855 n->m_next = m; 856 m = n; 857 m->m_len = optlen + sizeof(struct ip); 858 m->m_data += max_linkhdr; 859 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 860 } else { 861 m->m_data -= optlen; 862 m->m_len += optlen; 863 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 864 } 865 m->m_pkthdr.len += optlen; 866 ip = mtod(m, struct ip *); 867 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 868 *phlen = sizeof(struct ip) + optlen; 869 ip->ip_len += optlen; 870 return (m); 871 } 872 873 /* 874 * Copy options from ip to jp, 875 * omitting those not copied during fragmentation. 876 */ 877 int 878 ip_optcopy(ip, jp) 879 struct ip *ip, *jp; 880 { 881 u_char *cp, *dp; 882 int opt, optlen, cnt; 883 884 cp = (u_char *)(ip + 1); 885 dp = (u_char *)(jp + 1); 886 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 887 for (; cnt > 0; cnt -= optlen, cp += optlen) { 888 opt = cp[0]; 889 if (opt == IPOPT_EOL) 890 break; 891 if (opt == IPOPT_NOP) { 892 /* Preserve for IP mcast tunnel's LSRR alignment. */ 893 *dp++ = IPOPT_NOP; 894 optlen = 1; 895 continue; 896 } 897 #ifdef DIAGNOSTIC 898 if (cnt < IPOPT_OLEN + sizeof(*cp)) 899 panic("malformed IPv4 option passed to ip_optcopy"); 900 #endif 901 optlen = cp[IPOPT_OLEN]; 902 #ifdef DIAGNOSTIC 903 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 904 panic("malformed IPv4 option passed to ip_optcopy"); 905 #endif 906 /* bogus lengths should have been caught by ip_dooptions */ 907 if (optlen > cnt) 908 optlen = cnt; 909 if (IPOPT_COPIED(opt)) { 910 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 911 dp += optlen; 912 } 913 } 914 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 915 *dp++ = IPOPT_EOL; 916 return (optlen); 917 } 918 919 /* 920 * IP socket option processing. 921 */ 922 int 923 ip_ctloutput(op, so, level, optname, mp) 924 int op; 925 struct socket *so; 926 int level, optname; 927 struct mbuf **mp; 928 { 929 struct inpcb *inp = sotoinpcb(so); 930 struct mbuf *m = *mp; 931 int optval = 0; 932 int error = 0; 933 #ifdef IPSEC 934 #ifdef __NetBSD__ 935 struct proc *p = curproc; /*XXX*/ 936 #endif 937 #endif 938 939 if (level != IPPROTO_IP) { 940 error = EINVAL; 941 if (op == PRCO_SETOPT && *mp) 942 (void) m_free(*mp); 943 } else switch (op) { 944 945 case PRCO_SETOPT: 946 switch (optname) { 947 case IP_OPTIONS: 948 #ifdef notyet 949 case IP_RETOPTS: 950 return (ip_pcbopts(optname, &inp->inp_options, m)); 951 #else 952 return (ip_pcbopts(&inp->inp_options, m)); 953 #endif 954 955 case IP_TOS: 956 case IP_TTL: 957 case IP_RECVOPTS: 958 case IP_RECVRETOPTS: 959 case IP_RECVDSTADDR: 960 case IP_RECVIF: 961 if (m == NULL || m->m_len != sizeof(int)) 962 error = EINVAL; 963 else { 964 optval = *mtod(m, int *); 965 switch (optname) { 966 967 case IP_TOS: 968 inp->inp_ip.ip_tos = optval; 969 break; 970 971 case IP_TTL: 972 inp->inp_ip.ip_ttl = optval; 973 break; 974 #define OPTSET(bit) \ 975 if (optval) \ 976 inp->inp_flags |= bit; \ 977 else \ 978 inp->inp_flags &= ~bit; 979 980 case IP_RECVOPTS: 981 OPTSET(INP_RECVOPTS); 982 break; 983 984 case IP_RECVRETOPTS: 985 OPTSET(INP_RECVRETOPTS); 986 break; 987 988 case IP_RECVDSTADDR: 989 OPTSET(INP_RECVDSTADDR); 990 break; 991 992 case IP_RECVIF: 993 OPTSET(INP_RECVIF); 994 break; 995 } 996 } 997 break; 998 #undef OPTSET 999 1000 case IP_MULTICAST_IF: 1001 case IP_MULTICAST_TTL: 1002 case IP_MULTICAST_LOOP: 1003 case IP_ADD_MEMBERSHIP: 1004 case IP_DROP_MEMBERSHIP: 1005 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1006 break; 1007 1008 case IP_PORTRANGE: 1009 if (m == 0 || m->m_len != sizeof(int)) 1010 error = EINVAL; 1011 else { 1012 optval = *mtod(m, int *); 1013 1014 switch (optval) { 1015 1016 case IP_PORTRANGE_DEFAULT: 1017 case IP_PORTRANGE_HIGH: 1018 inp->inp_flags &= ~(INP_LOWPORT); 1019 break; 1020 1021 case IP_PORTRANGE_LOW: 1022 inp->inp_flags |= INP_LOWPORT; 1023 break; 1024 1025 default: 1026 error = EINVAL; 1027 break; 1028 } 1029 } 1030 break; 1031 1032 #ifdef IPSEC 1033 case IP_IPSEC_POLICY: 1034 { 1035 caddr_t req = NULL; 1036 size_t len = 0; 1037 int priv = 0; 1038 1039 #ifdef __NetBSD__ 1040 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1041 priv = 0; 1042 else 1043 priv = 1; 1044 #else 1045 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1046 #endif 1047 if (m) { 1048 req = mtod(m, caddr_t); 1049 len = m->m_len; 1050 } 1051 error = ipsec4_set_policy(inp, optname, req, len, priv); 1052 break; 1053 } 1054 #endif /*IPSEC*/ 1055 1056 default: 1057 error = ENOPROTOOPT; 1058 break; 1059 } 1060 if (m) 1061 (void)m_free(m); 1062 break; 1063 1064 case PRCO_GETOPT: 1065 switch (optname) { 1066 case IP_OPTIONS: 1067 case IP_RETOPTS: 1068 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1069 if (inp->inp_options) { 1070 m->m_len = inp->inp_options->m_len; 1071 bcopy(mtod(inp->inp_options, caddr_t), 1072 mtod(m, caddr_t), (unsigned)m->m_len); 1073 } else 1074 m->m_len = 0; 1075 break; 1076 1077 case IP_TOS: 1078 case IP_TTL: 1079 case IP_RECVOPTS: 1080 case IP_RECVRETOPTS: 1081 case IP_RECVDSTADDR: 1082 case IP_RECVIF: 1083 case IP_ERRORMTU: 1084 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1085 m->m_len = sizeof(int); 1086 switch (optname) { 1087 1088 case IP_TOS: 1089 optval = inp->inp_ip.ip_tos; 1090 break; 1091 1092 case IP_TTL: 1093 optval = inp->inp_ip.ip_ttl; 1094 break; 1095 1096 case IP_ERRORMTU: 1097 optval = inp->inp_errormtu; 1098 break; 1099 1100 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1101 1102 case IP_RECVOPTS: 1103 optval = OPTBIT(INP_RECVOPTS); 1104 break; 1105 1106 case IP_RECVRETOPTS: 1107 optval = OPTBIT(INP_RECVRETOPTS); 1108 break; 1109 1110 case IP_RECVDSTADDR: 1111 optval = OPTBIT(INP_RECVDSTADDR); 1112 break; 1113 1114 case IP_RECVIF: 1115 optval = OPTBIT(INP_RECVIF); 1116 break; 1117 } 1118 *mtod(m, int *) = optval; 1119 break; 1120 1121 #ifdef IPSEC 1122 case IP_IPSEC_POLICY: 1123 { 1124 caddr_t req = NULL; 1125 size_t len = 0; 1126 1127 if (m) { 1128 req = mtod(m, caddr_t); 1129 len = m->m_len; 1130 } 1131 error = ipsec4_get_policy(inp, req, len, mp); 1132 break; 1133 } 1134 #endif /*IPSEC*/ 1135 1136 case IP_MULTICAST_IF: 1137 case IP_MULTICAST_TTL: 1138 case IP_MULTICAST_LOOP: 1139 case IP_ADD_MEMBERSHIP: 1140 case IP_DROP_MEMBERSHIP: 1141 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1142 break; 1143 1144 case IP_PORTRANGE: 1145 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1146 m->m_len = sizeof(int); 1147 1148 if (inp->inp_flags & INP_LOWPORT) 1149 optval = IP_PORTRANGE_LOW; 1150 else 1151 optval = IP_PORTRANGE_DEFAULT; 1152 1153 *mtod(m, int *) = optval; 1154 break; 1155 1156 default: 1157 error = ENOPROTOOPT; 1158 break; 1159 } 1160 break; 1161 } 1162 return (error); 1163 } 1164 1165 /* 1166 * Set up IP options in pcb for insertion in output packets. 1167 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1168 * with destination address if source routed. 1169 */ 1170 int 1171 #ifdef notyet 1172 ip_pcbopts(optname, pcbopt, m) 1173 int optname; 1174 #else 1175 ip_pcbopts(pcbopt, m) 1176 #endif 1177 struct mbuf **pcbopt; 1178 struct mbuf *m; 1179 { 1180 int cnt, optlen; 1181 u_char *cp; 1182 u_char opt; 1183 1184 /* turn off any old options */ 1185 if (*pcbopt) 1186 (void)m_free(*pcbopt); 1187 *pcbopt = 0; 1188 if (m == (struct mbuf *)0 || m->m_len == 0) { 1189 /* 1190 * Only turning off any previous options. 1191 */ 1192 if (m) 1193 (void)m_free(m); 1194 return (0); 1195 } 1196 1197 #ifndef __vax__ 1198 if (m->m_len % sizeof(int32_t)) 1199 goto bad; 1200 #endif 1201 /* 1202 * IP first-hop destination address will be stored before 1203 * actual options; move other options back 1204 * and clear it when none present. 1205 */ 1206 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1207 goto bad; 1208 cnt = m->m_len; 1209 m->m_len += sizeof(struct in_addr); 1210 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1211 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1212 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1213 1214 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1215 opt = cp[IPOPT_OPTVAL]; 1216 if (opt == IPOPT_EOL) 1217 break; 1218 if (opt == IPOPT_NOP) 1219 optlen = 1; 1220 else { 1221 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1222 goto bad; 1223 optlen = cp[IPOPT_OLEN]; 1224 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1225 goto bad; 1226 } 1227 switch (opt) { 1228 1229 default: 1230 break; 1231 1232 case IPOPT_LSRR: 1233 case IPOPT_SSRR: 1234 /* 1235 * user process specifies route as: 1236 * ->A->B->C->D 1237 * D must be our final destination (but we can't 1238 * check that since we may not have connected yet). 1239 * A is first hop destination, which doesn't appear in 1240 * actual IP option, but is stored before the options. 1241 */ 1242 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1243 goto bad; 1244 m->m_len -= sizeof(struct in_addr); 1245 cnt -= sizeof(struct in_addr); 1246 optlen -= sizeof(struct in_addr); 1247 cp[IPOPT_OLEN] = optlen; 1248 /* 1249 * Move first hop before start of options. 1250 */ 1251 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1252 sizeof(struct in_addr)); 1253 /* 1254 * Then copy rest of options back 1255 * to close up the deleted entry. 1256 */ 1257 memmove(&cp[IPOPT_OFFSET+1], 1258 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1259 (unsigned)cnt + sizeof(struct in_addr)); 1260 break; 1261 } 1262 } 1263 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1264 goto bad; 1265 *pcbopt = m; 1266 return (0); 1267 1268 bad: 1269 (void)m_free(m); 1270 return (EINVAL); 1271 } 1272 1273 /* 1274 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1275 */ 1276 static struct ifnet * 1277 ip_multicast_if(a, ifindexp) 1278 struct in_addr *a; 1279 int *ifindexp; 1280 { 1281 int ifindex; 1282 struct ifnet *ifp; 1283 1284 if (ifindexp) 1285 *ifindexp = 0; 1286 if (ntohl(a->s_addr) >> 24 == 0) { 1287 ifindex = ntohl(a->s_addr) & 0xffffff; 1288 if (ifindex < 0 || if_index < ifindex) 1289 return NULL; 1290 ifp = ifindex2ifnet[ifindex]; 1291 if (ifindexp) 1292 *ifindexp = ifindex; 1293 } else { 1294 INADDR_TO_IFP(*a, ifp); 1295 } 1296 return ifp; 1297 } 1298 1299 /* 1300 * Set the IP multicast options in response to user setsockopt(). 1301 */ 1302 int 1303 ip_setmoptions(optname, imop, m) 1304 int optname; 1305 struct ip_moptions **imop; 1306 struct mbuf *m; 1307 { 1308 int error = 0; 1309 u_char loop; 1310 int i; 1311 struct in_addr addr; 1312 struct ip_mreq *mreq; 1313 struct ifnet *ifp; 1314 struct ip_moptions *imo = *imop; 1315 struct route ro; 1316 struct sockaddr_in *dst; 1317 int ifindex; 1318 1319 if (imo == NULL) { 1320 /* 1321 * No multicast option buffer attached to the pcb; 1322 * allocate one and initialize to default values. 1323 */ 1324 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1325 M_WAITOK); 1326 1327 if (imo == NULL) 1328 return (ENOBUFS); 1329 *imop = imo; 1330 imo->imo_multicast_ifp = NULL; 1331 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1332 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1333 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1334 imo->imo_num_memberships = 0; 1335 } 1336 1337 switch (optname) { 1338 1339 case IP_MULTICAST_IF: 1340 /* 1341 * Select the interface for outgoing multicast packets. 1342 */ 1343 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1344 error = EINVAL; 1345 break; 1346 } 1347 addr = *(mtod(m, struct in_addr *)); 1348 /* 1349 * INADDR_ANY is used to remove a previous selection. 1350 * When no interface is selected, a default one is 1351 * chosen every time a multicast packet is sent. 1352 */ 1353 if (in_nullhost(addr)) { 1354 imo->imo_multicast_ifp = NULL; 1355 break; 1356 } 1357 /* 1358 * The selected interface is identified by its local 1359 * IP address. Find the interface and confirm that 1360 * it supports multicasting. 1361 */ 1362 ifp = ip_multicast_if(&addr, &ifindex); 1363 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1364 error = EADDRNOTAVAIL; 1365 break; 1366 } 1367 imo->imo_multicast_ifp = ifp; 1368 if (ifindex) 1369 imo->imo_multicast_addr = addr; 1370 else 1371 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1372 break; 1373 1374 case IP_MULTICAST_TTL: 1375 /* 1376 * Set the IP time-to-live for outgoing multicast packets. 1377 */ 1378 if (m == NULL || m->m_len != 1) { 1379 error = EINVAL; 1380 break; 1381 } 1382 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1383 break; 1384 1385 case IP_MULTICAST_LOOP: 1386 /* 1387 * Set the loopback flag for outgoing multicast packets. 1388 * Must be zero or one. 1389 */ 1390 if (m == NULL || m->m_len != 1 || 1391 (loop = *(mtod(m, u_char *))) > 1) { 1392 error = EINVAL; 1393 break; 1394 } 1395 imo->imo_multicast_loop = loop; 1396 break; 1397 1398 case IP_ADD_MEMBERSHIP: 1399 /* 1400 * Add a multicast group membership. 1401 * Group must be a valid IP multicast address. 1402 */ 1403 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1404 error = EINVAL; 1405 break; 1406 } 1407 mreq = mtod(m, struct ip_mreq *); 1408 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1409 error = EINVAL; 1410 break; 1411 } 1412 /* 1413 * If no interface address was provided, use the interface of 1414 * the route to the given multicast address. 1415 */ 1416 if (in_nullhost(mreq->imr_interface)) { 1417 bzero((caddr_t)&ro, sizeof(ro)); 1418 ro.ro_rt = NULL; 1419 dst = satosin(&ro.ro_dst); 1420 dst->sin_len = sizeof(*dst); 1421 dst->sin_family = AF_INET; 1422 dst->sin_addr = mreq->imr_multiaddr; 1423 rtalloc(&ro); 1424 if (ro.ro_rt == NULL) { 1425 error = EADDRNOTAVAIL; 1426 break; 1427 } 1428 ifp = ro.ro_rt->rt_ifp; 1429 rtfree(ro.ro_rt); 1430 } else { 1431 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1432 } 1433 /* 1434 * See if we found an interface, and confirm that it 1435 * supports multicast. 1436 */ 1437 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1438 error = EADDRNOTAVAIL; 1439 break; 1440 } 1441 /* 1442 * See if the membership already exists or if all the 1443 * membership slots are full. 1444 */ 1445 for (i = 0; i < imo->imo_num_memberships; ++i) { 1446 if (imo->imo_membership[i]->inm_ifp == ifp && 1447 in_hosteq(imo->imo_membership[i]->inm_addr, 1448 mreq->imr_multiaddr)) 1449 break; 1450 } 1451 if (i < imo->imo_num_memberships) { 1452 error = EADDRINUSE; 1453 break; 1454 } 1455 if (i == IP_MAX_MEMBERSHIPS) { 1456 error = ETOOMANYREFS; 1457 break; 1458 } 1459 /* 1460 * Everything looks good; add a new record to the multicast 1461 * address list for the given interface. 1462 */ 1463 if ((imo->imo_membership[i] = 1464 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1465 error = ENOBUFS; 1466 break; 1467 } 1468 ++imo->imo_num_memberships; 1469 break; 1470 1471 case IP_DROP_MEMBERSHIP: 1472 /* 1473 * Drop a multicast group membership. 1474 * Group must be a valid IP multicast address. 1475 */ 1476 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1477 error = EINVAL; 1478 break; 1479 } 1480 mreq = mtod(m, struct ip_mreq *); 1481 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1482 error = EINVAL; 1483 break; 1484 } 1485 /* 1486 * If an interface address was specified, get a pointer 1487 * to its ifnet structure. 1488 */ 1489 if (in_nullhost(mreq->imr_interface)) 1490 ifp = NULL; 1491 else { 1492 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1493 if (ifp == NULL) { 1494 error = EADDRNOTAVAIL; 1495 break; 1496 } 1497 } 1498 /* 1499 * Find the membership in the membership array. 1500 */ 1501 for (i = 0; i < imo->imo_num_memberships; ++i) { 1502 if ((ifp == NULL || 1503 imo->imo_membership[i]->inm_ifp == ifp) && 1504 in_hosteq(imo->imo_membership[i]->inm_addr, 1505 mreq->imr_multiaddr)) 1506 break; 1507 } 1508 if (i == imo->imo_num_memberships) { 1509 error = EADDRNOTAVAIL; 1510 break; 1511 } 1512 /* 1513 * Give up the multicast address record to which the 1514 * membership points. 1515 */ 1516 in_delmulti(imo->imo_membership[i]); 1517 /* 1518 * Remove the gap in the membership array. 1519 */ 1520 for (++i; i < imo->imo_num_memberships; ++i) 1521 imo->imo_membership[i-1] = imo->imo_membership[i]; 1522 --imo->imo_num_memberships; 1523 break; 1524 1525 default: 1526 error = EOPNOTSUPP; 1527 break; 1528 } 1529 1530 /* 1531 * If all options have default values, no need to keep the mbuf. 1532 */ 1533 if (imo->imo_multicast_ifp == NULL && 1534 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1535 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1536 imo->imo_num_memberships == 0) { 1537 free(*imop, M_IPMOPTS); 1538 *imop = NULL; 1539 } 1540 1541 return (error); 1542 } 1543 1544 /* 1545 * Return the IP multicast options in response to user getsockopt(). 1546 */ 1547 int 1548 ip_getmoptions(optname, imo, mp) 1549 int optname; 1550 struct ip_moptions *imo; 1551 struct mbuf **mp; 1552 { 1553 u_char *ttl; 1554 u_char *loop; 1555 struct in_addr *addr; 1556 struct in_ifaddr *ia; 1557 1558 *mp = m_get(M_WAIT, MT_SOOPTS); 1559 1560 switch (optname) { 1561 1562 case IP_MULTICAST_IF: 1563 addr = mtod(*mp, struct in_addr *); 1564 (*mp)->m_len = sizeof(struct in_addr); 1565 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1566 *addr = zeroin_addr; 1567 else if (imo->imo_multicast_addr.s_addr) { 1568 /* return the value user has set */ 1569 *addr = imo->imo_multicast_addr; 1570 } else { 1571 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1572 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1573 } 1574 return (0); 1575 1576 case IP_MULTICAST_TTL: 1577 ttl = mtod(*mp, u_char *); 1578 (*mp)->m_len = 1; 1579 *ttl = imo ? imo->imo_multicast_ttl 1580 : IP_DEFAULT_MULTICAST_TTL; 1581 return (0); 1582 1583 case IP_MULTICAST_LOOP: 1584 loop = mtod(*mp, u_char *); 1585 (*mp)->m_len = 1; 1586 *loop = imo ? imo->imo_multicast_loop 1587 : IP_DEFAULT_MULTICAST_LOOP; 1588 return (0); 1589 1590 default: 1591 return (EOPNOTSUPP); 1592 } 1593 } 1594 1595 /* 1596 * Discard the IP multicast options. 1597 */ 1598 void 1599 ip_freemoptions(imo) 1600 struct ip_moptions *imo; 1601 { 1602 int i; 1603 1604 if (imo != NULL) { 1605 for (i = 0; i < imo->imo_num_memberships; ++i) 1606 in_delmulti(imo->imo_membership[i]); 1607 free(imo, M_IPMOPTS); 1608 } 1609 } 1610 1611 /* 1612 * Routine called from ip_output() to loop back a copy of an IP multicast 1613 * packet to the input queue of a specified interface. Note that this 1614 * calls the output routine of the loopback "driver", but with an interface 1615 * pointer that might NOT be &loif -- easier than replicating that code here. 1616 */ 1617 static void 1618 ip_mloopback(ifp, m, dst) 1619 struct ifnet *ifp; 1620 struct mbuf *m; 1621 struct sockaddr_in *dst; 1622 { 1623 struct ip *ip; 1624 struct mbuf *copym; 1625 1626 copym = m_copy(m, 0, M_COPYALL); 1627 if (copym != NULL 1628 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1629 copym = m_pullup(copym, sizeof(struct ip)); 1630 if (copym != NULL) { 1631 /* 1632 * We don't bother to fragment if the IP length is greater 1633 * than the interface's MTU. Can this possibly matter? 1634 */ 1635 ip = mtod(copym, struct ip *); 1636 HTONS(ip->ip_len); 1637 HTONS(ip->ip_off); 1638 ip->ip_sum = 0; 1639 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1640 (void) looutput(ifp, copym, sintosa(dst), NULL); 1641 } 1642 } 1643