1 /* $NetBSD: ip_output.c,v 1.86 2001/06/02 16:17:10 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 #include <machine/stdarg.h> 134 135 #ifdef IPSEC 136 #include <netinet6/ipsec.h> 137 #include <netkey/key.h> 138 #include <netkey/key_debug.h> 139 #endif /*IPSEC*/ 140 141 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 142 static struct ifnet *ip_multicast_if __P((struct in_addr *, int *)); 143 static void ip_mloopback 144 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); 145 146 #ifdef PFIL_HOOKS 147 extern struct pfil_head inet_pfil_hook; /* XXX */ 148 #endif 149 150 /* 151 * IP output. The packet in mbuf chain m contains a skeletal IP 152 * header (with len, off, ttl, proto, tos, src, dst). 153 * The mbuf chain containing the packet will be freed. 154 * The mbuf opt, if present, will not be freed. 155 */ 156 int 157 #if __STDC__ 158 ip_output(struct mbuf *m0, ...) 159 #else 160 ip_output(m0, va_alist) 161 struct mbuf *m0; 162 va_dcl 163 #endif 164 { 165 struct ip *ip, *mhip; 166 struct ifnet *ifp; 167 struct mbuf *m = m0; 168 int hlen = sizeof (struct ip); 169 int len, off, error = 0; 170 struct route iproute; 171 struct sockaddr_in *dst; 172 struct in_ifaddr *ia; 173 struct mbuf *opt; 174 struct route *ro; 175 int flags, sw_csum; 176 int *mtu_p; 177 int mtu; 178 struct ip_moptions *imo; 179 va_list ap; 180 #ifdef IPSEC 181 struct socket *so; 182 struct secpolicy *sp = NULL; 183 #endif /*IPSEC*/ 184 u_int16_t ip_len; 185 186 va_start(ap, m0); 187 opt = va_arg(ap, struct mbuf *); 188 ro = va_arg(ap, struct route *); 189 flags = va_arg(ap, int); 190 imo = va_arg(ap, struct ip_moptions *); 191 if (flags & IP_RETURNMTU) 192 mtu_p = va_arg(ap, int *); 193 else 194 mtu_p = NULL; 195 va_end(ap); 196 197 #ifdef IPSEC 198 so = ipsec_getsocket(m); 199 (void)ipsec_setsocket(m, NULL); 200 #endif /*IPSEC*/ 201 202 #ifdef DIAGNOSTIC 203 if ((m->m_flags & M_PKTHDR) == 0) 204 panic("ip_output no HDR"); 205 #endif 206 if (opt) { 207 m = ip_insertoptions(m, opt, &len); 208 hlen = len; 209 } 210 ip = mtod(m, struct ip *); 211 /* 212 * Fill in IP header. 213 */ 214 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 215 ip->ip_v = IPVERSION; 216 ip->ip_off = 0; 217 ip->ip_id = htons(ip_id++); 218 ip->ip_hl = hlen >> 2; 219 ipstat.ips_localout++; 220 } else { 221 hlen = ip->ip_hl << 2; 222 } 223 /* 224 * Route packet. 225 */ 226 if (ro == 0) { 227 ro = &iproute; 228 bzero((caddr_t)ro, sizeof (*ro)); 229 } 230 dst = satosin(&ro->ro_dst); 231 /* 232 * If there is a cached route, 233 * check that it is to the same destination 234 * and is still up. If not, free it and try again. 235 */ 236 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 237 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 238 RTFREE(ro->ro_rt); 239 ro->ro_rt = (struct rtentry *)0; 240 } 241 if (ro->ro_rt == 0) { 242 dst->sin_family = AF_INET; 243 dst->sin_len = sizeof(*dst); 244 dst->sin_addr = ip->ip_dst; 245 } 246 /* 247 * If routing to interface only, 248 * short circuit routing lookup. 249 */ 250 if (flags & IP_ROUTETOIF) { 251 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 252 ipstat.ips_noroute++; 253 error = ENETUNREACH; 254 goto bad; 255 } 256 ifp = ia->ia_ifp; 257 mtu = ifp->if_mtu; 258 ip->ip_ttl = 1; 259 } else { 260 if (ro->ro_rt == 0) 261 rtalloc(ro); 262 if (ro->ro_rt == 0) { 263 ipstat.ips_noroute++; 264 error = EHOSTUNREACH; 265 goto bad; 266 } 267 ia = ifatoia(ro->ro_rt->rt_ifa); 268 ifp = ro->ro_rt->rt_ifp; 269 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 270 mtu = ifp->if_mtu; 271 ro->ro_rt->rt_use++; 272 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 273 dst = satosin(ro->ro_rt->rt_gateway); 274 } 275 if (IN_MULTICAST(ip->ip_dst.s_addr) || 276 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 277 struct in_multi *inm; 278 279 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 280 M_BCAST : M_MCAST; 281 /* 282 * IP destination address is multicast. Make sure "dst" 283 * still points to the address in "ro". (It may have been 284 * changed to point to a gateway address, above.) 285 */ 286 dst = satosin(&ro->ro_dst); 287 /* 288 * See if the caller provided any multicast options 289 */ 290 if (imo != NULL) { 291 ip->ip_ttl = imo->imo_multicast_ttl; 292 if (imo->imo_multicast_ifp != NULL) { 293 ifp = imo->imo_multicast_ifp; 294 mtu = ifp->if_mtu; 295 } 296 } else 297 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 298 /* 299 * Confirm that the outgoing interface supports multicast. 300 */ 301 if (((m->m_flags & M_MCAST) && 302 (ifp->if_flags & IFF_MULTICAST) == 0) || 303 ((m->m_flags & M_BCAST) && 304 (ifp->if_flags & IFF_BROADCAST) == 0)) { 305 ipstat.ips_noroute++; 306 error = ENETUNREACH; 307 goto bad; 308 } 309 /* 310 * If source address not specified yet, use an address 311 * of outgoing interface. 312 */ 313 if (in_nullhost(ip->ip_src)) { 314 struct in_ifaddr *ia; 315 316 IFP_TO_IA(ifp, ia); 317 ip->ip_src = ia->ia_addr.sin_addr; 318 } 319 320 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 321 if (inm != NULL && 322 (imo == NULL || imo->imo_multicast_loop)) { 323 /* 324 * If we belong to the destination multicast group 325 * on the outgoing interface, and the caller did not 326 * forbid loopback, loop back a copy. 327 */ 328 ip_mloopback(ifp, m, dst); 329 } 330 #ifdef MROUTING 331 else { 332 /* 333 * If we are acting as a multicast router, perform 334 * multicast forwarding as if the packet had just 335 * arrived on the interface to which we are about 336 * to send. The multicast forwarding function 337 * recursively calls this function, using the 338 * IP_FORWARDING flag to prevent infinite recursion. 339 * 340 * Multicasts that are looped back by ip_mloopback(), 341 * above, will be forwarded by the ip_input() routine, 342 * if necessary. 343 */ 344 extern struct socket *ip_mrouter; 345 346 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 347 if (ip_mforward(m, ifp) != 0) { 348 m_freem(m); 349 goto done; 350 } 351 } 352 } 353 #endif 354 /* 355 * Multicasts with a time-to-live of zero may be looped- 356 * back, above, but must not be transmitted on a network. 357 * Also, multicasts addressed to the loopback interface 358 * are not sent -- the above call to ip_mloopback() will 359 * loop back a copy if this host actually belongs to the 360 * destination group on the loopback interface. 361 */ 362 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 363 m_freem(m); 364 goto done; 365 } 366 367 goto sendit; 368 } 369 #ifndef notdef 370 /* 371 * If source address not specified yet, use address 372 * of outgoing interface. 373 */ 374 if (in_nullhost(ip->ip_src)) 375 ip->ip_src = ia->ia_addr.sin_addr; 376 #endif 377 378 /* 379 * packets with Class-D address as source are not valid per 380 * RFC 1112 381 */ 382 if (IN_MULTICAST(ip->ip_src.s_addr)) { 383 ipstat.ips_odropped++; 384 error = EADDRNOTAVAIL; 385 goto bad; 386 } 387 388 /* 389 * Look for broadcast address and 390 * and verify user is allowed to send 391 * such a packet. 392 */ 393 if (in_broadcast(dst->sin_addr, ifp)) { 394 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 395 error = EADDRNOTAVAIL; 396 goto bad; 397 } 398 if ((flags & IP_ALLOWBROADCAST) == 0) { 399 error = EACCES; 400 goto bad; 401 } 402 /* don't allow broadcast messages to be fragmented */ 403 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 404 error = EMSGSIZE; 405 goto bad; 406 } 407 m->m_flags |= M_BCAST; 408 } else 409 m->m_flags &= ~M_BCAST; 410 411 sendit: 412 /* 413 * If we're doing Path MTU Discovery, we need to set DF unless 414 * the route's MTU is locked. 415 */ 416 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 417 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 418 ip->ip_off |= IP_DF; 419 420 /* 421 * Remember the current ip_len and ip_off, and swap them into 422 * network order. 423 */ 424 ip_len = ip->ip_len; 425 426 HTONS(ip->ip_len); 427 HTONS(ip->ip_off); 428 429 #ifdef IPSEC 430 /* get SP for this packet */ 431 if (so == NULL) 432 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 433 else 434 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 435 436 if (sp == NULL) { 437 ipsecstat.out_inval++; 438 goto bad; 439 } 440 441 error = 0; 442 443 /* check policy */ 444 switch (sp->policy) { 445 case IPSEC_POLICY_DISCARD: 446 /* 447 * This packet is just discarded. 448 */ 449 ipsecstat.out_polvio++; 450 goto bad; 451 452 case IPSEC_POLICY_BYPASS: 453 case IPSEC_POLICY_NONE: 454 /* no need to do IPsec. */ 455 goto skip_ipsec; 456 457 case IPSEC_POLICY_IPSEC: 458 if (sp->req == NULL) { 459 /* XXX should be panic ? */ 460 printf("ip_output: No IPsec request specified.\n"); 461 error = EINVAL; 462 goto bad; 463 } 464 break; 465 466 case IPSEC_POLICY_ENTRUST: 467 default: 468 printf("ip_output: Invalid policy found. %d\n", sp->policy); 469 } 470 471 /* 472 * ipsec4_output() expects ip_len and ip_off in network 473 * order. They have been set to network order above. 474 */ 475 476 { 477 struct ipsec_output_state state; 478 bzero(&state, sizeof(state)); 479 state.m = m; 480 if (flags & IP_ROUTETOIF) { 481 state.ro = &iproute; 482 bzero(&iproute, sizeof(iproute)); 483 } else 484 state.ro = ro; 485 state.dst = (struct sockaddr *)dst; 486 487 /* 488 * We can't defer the checksum of payload data if 489 * we're about to encrypt/authenticate it. 490 * 491 * XXX When we support crypto offloading functions of 492 * XXX network interfaces, we need to reconsider this, 493 * XXX since it's likely that they'll support checksumming, 494 * XXX as well. 495 */ 496 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 497 in_delayed_cksum(m); 498 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 499 } 500 501 error = ipsec4_output(&state, sp, flags); 502 503 m = state.m; 504 if (flags & IP_ROUTETOIF) { 505 /* 506 * if we have tunnel mode SA, we may need to ignore 507 * IP_ROUTETOIF. 508 */ 509 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 510 flags &= ~IP_ROUTETOIF; 511 ro = state.ro; 512 } 513 } else 514 ro = state.ro; 515 dst = (struct sockaddr_in *)state.dst; 516 if (error) { 517 /* mbuf is already reclaimed in ipsec4_output. */ 518 m0 = NULL; 519 switch (error) { 520 case EHOSTUNREACH: 521 case ENETUNREACH: 522 case EMSGSIZE: 523 case ENOBUFS: 524 case ENOMEM: 525 break; 526 default: 527 printf("ip4_output (ipsec): error code %d\n", error); 528 /*fall through*/ 529 case ENOENT: 530 /* don't show these error codes to the user */ 531 error = 0; 532 break; 533 } 534 goto bad; 535 } 536 } 537 538 /* be sure to update variables that are affected by ipsec4_output() */ 539 ip = mtod(m, struct ip *); 540 #ifdef _IP_VHL 541 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 542 #else 543 hlen = ip->ip_hl << 2; 544 #endif 545 ip_len = ntohs(ip->ip_len); 546 547 if (ro->ro_rt == NULL) { 548 if ((flags & IP_ROUTETOIF) == 0) { 549 printf("ip_output: " 550 "can't update route after IPsec processing\n"); 551 error = EHOSTUNREACH; /*XXX*/ 552 goto bad; 553 } 554 } else { 555 /* nobody uses ia beyond here */ 556 ifp = ro->ro_rt->rt_ifp; 557 } 558 559 skip_ipsec: 560 #endif /*IPSEC*/ 561 562 #ifdef PFIL_HOOKS 563 /* 564 * Run through list of hooks for output packets. 565 */ 566 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 567 PFIL_OUT)) != 0) 568 goto done; 569 if (m == NULL) 570 goto done; 571 572 ip = mtod(m, struct ip *); 573 #endif /* PFIL_HOOKS */ 574 575 /* 576 * If small enough for mtu of path, can just send directly. 577 */ 578 if (ip_len <= mtu) { 579 #if IFA_STATS 580 /* 581 * search for the source address structure to 582 * maintain output statistics. 583 */ 584 INADDR_TO_IA(ip->ip_src, ia); 585 if (ia) 586 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 587 #endif 588 /* 589 * Always initialize the sum to 0! Some HW assisted 590 * checksumming requires this. 591 */ 592 ip->ip_sum = 0; 593 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 594 595 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags; 596 597 /* 598 * Perform any checksums that the hardware can't do 599 * for us. 600 * 601 * XXX Does any hardware require the {th,uh}_sum 602 * XXX fields to be 0? 603 */ 604 if (sw_csum & M_CSUM_IPv4) 605 ip->ip_sum = in_cksum(m, hlen); 606 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 607 in_delayed_cksum(m); 608 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 609 } 610 m->m_pkthdr.csum_flags &= ifp->if_csum_flags; 611 612 #ifdef IPSEC 613 /* clean ipsec history once it goes out of the node */ 614 ipsec_delaux(m); 615 #endif 616 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 617 goto done; 618 } 619 620 /* 621 * We can't use HW checksumming if we're about to 622 * to fragment the packet. 623 * 624 * XXX Some hardware can do this. 625 */ 626 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 627 in_delayed_cksum(m); 628 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 629 } 630 631 /* 632 * Too large for interface; fragment if possible. 633 * Must be able to put at least 8 bytes per fragment. 634 * 635 * Note we swap ip_len and ip_off into host order to make 636 * the logic below a little simpler. 637 */ 638 639 NTOHS(ip->ip_len); 640 NTOHS(ip->ip_off); 641 642 if (ip->ip_off & IP_DF) { 643 if (flags & IP_RETURNMTU) 644 *mtu_p = mtu; 645 error = EMSGSIZE; 646 ipstat.ips_cantfrag++; 647 goto bad; 648 } 649 len = (mtu - hlen) &~ 7; 650 if (len < 8) { 651 error = EMSGSIZE; 652 goto bad; 653 } 654 655 { 656 int mhlen, firstlen = len; 657 struct mbuf **mnext = &m->m_nextpkt; 658 int fragments = 0; 659 int s; 660 661 /* 662 * Loop through length of segment after first fragment, 663 * make new header and copy data of each part and link onto chain. 664 */ 665 m0 = m; 666 mhlen = sizeof (struct ip); 667 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 668 MGETHDR(m, M_DONTWAIT, MT_HEADER); 669 if (m == 0) { 670 error = ENOBUFS; 671 ipstat.ips_odropped++; 672 goto sendorfree; 673 } 674 *mnext = m; 675 mnext = &m->m_nextpkt; 676 m->m_data += max_linkhdr; 677 mhip = mtod(m, struct ip *); 678 *mhip = *ip; 679 /* we must inherit MCAST and BCAST flags */ 680 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 681 if (hlen > sizeof (struct ip)) { 682 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 683 mhip->ip_hl = mhlen >> 2; 684 } 685 m->m_len = mhlen; 686 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 687 if (ip->ip_off & IP_MF) 688 mhip->ip_off |= IP_MF; 689 if (off + len >= (u_int16_t)ip->ip_len) 690 len = (u_int16_t)ip->ip_len - off; 691 else 692 mhip->ip_off |= IP_MF; 693 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 694 m->m_next = m_copy(m0, off, len); 695 if (m->m_next == 0) { 696 error = ENOBUFS; /* ??? */ 697 ipstat.ips_odropped++; 698 goto sendorfree; 699 } 700 m->m_pkthdr.len = mhlen + len; 701 m->m_pkthdr.rcvif = (struct ifnet *)0; 702 HTONS(mhip->ip_off); 703 mhip->ip_sum = 0; 704 mhip->ip_sum = in_cksum(m, mhlen); 705 ipstat.ips_ofragments++; 706 fragments++; 707 } 708 /* 709 * Update first fragment by trimming what's been copied out 710 * and updating header, then send each fragment (in order). 711 */ 712 m = m0; 713 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 714 m->m_pkthdr.len = hlen + firstlen; 715 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 716 ip->ip_off |= IP_MF; 717 HTONS(ip->ip_off); 718 ip->ip_sum = 0; 719 ip->ip_sum = in_cksum(m, hlen); 720 sendorfree: 721 /* 722 * If there is no room for all the fragments, don't queue 723 * any of them. 724 */ 725 s = splnet(); 726 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 727 error = ENOBUFS; 728 splx(s); 729 for (m = m0; m; m = m0) { 730 m0 = m->m_nextpkt; 731 m->m_nextpkt = 0; 732 if (error == 0) { 733 #if IFA_STATS 734 /* 735 * search for the source address structure to 736 * maintain output statistics. 737 */ 738 INADDR_TO_IA(ip->ip_src, ia); 739 if (ia) { 740 ia->ia_ifa.ifa_data.ifad_outbytes += 741 ntohs(ip->ip_len); 742 } 743 #endif 744 #ifdef IPSEC 745 /* clean ipsec history once it goes out of the node */ 746 ipsec_delaux(m); 747 #endif 748 error = (*ifp->if_output)(ifp, m, sintosa(dst), 749 ro->ro_rt); 750 } else 751 m_freem(m); 752 } 753 754 if (error == 0) 755 ipstat.ips_fragmented++; 756 } 757 done: 758 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 759 RTFREE(ro->ro_rt); 760 ro->ro_rt = 0; 761 } 762 763 #ifdef IPSEC 764 if (sp != NULL) { 765 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 766 printf("DP ip_output call free SP:%p\n", sp)); 767 key_freesp(sp); 768 } 769 #endif /* IPSEC */ 770 771 return (error); 772 bad: 773 m_freem(m); 774 goto done; 775 } 776 777 /* 778 * Process a delayed payload checksum calculation. 779 */ 780 void 781 in_delayed_cksum(struct mbuf *m) 782 { 783 struct ip *ip; 784 u_int16_t csum, offset; 785 786 ip = mtod(m, struct ip *); 787 offset = ip->ip_hl << 2; 788 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 789 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 790 csum = 0xffff; 791 792 offset += m->m_pkthdr.csum_data; /* checksum offset */ 793 794 if ((offset + sizeof(u_int16_t)) > m->m_len) { 795 /* XXX This should basically never happen. */ 796 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 797 m->m_len, offset, ip->ip_p); 798 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 799 } else 800 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 801 } 802 803 /* 804 * Determine the maximum length of the options to be inserted; 805 * we would far rather allocate too much space rather than too little. 806 */ 807 808 u_int 809 ip_optlen(inp) 810 struct inpcb *inp; 811 { 812 struct mbuf *m = inp->inp_options; 813 814 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 815 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 816 else 817 return 0; 818 } 819 820 821 /* 822 * Insert IP options into preformed packet. 823 * Adjust IP destination as required for IP source routing, 824 * as indicated by a non-zero in_addr at the start of the options. 825 */ 826 static struct mbuf * 827 ip_insertoptions(m, opt, phlen) 828 struct mbuf *m; 829 struct mbuf *opt; 830 int *phlen; 831 { 832 struct ipoption *p = mtod(opt, struct ipoption *); 833 struct mbuf *n; 834 struct ip *ip = mtod(m, struct ip *); 835 unsigned optlen; 836 837 optlen = opt->m_len - sizeof(p->ipopt_dst); 838 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 839 return (m); /* XXX should fail */ 840 if (!in_nullhost(p->ipopt_dst)) 841 ip->ip_dst = p->ipopt_dst; 842 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 843 MGETHDR(n, M_DONTWAIT, MT_HEADER); 844 if (n == 0) 845 return (m); 846 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 847 m->m_len -= sizeof(struct ip); 848 m->m_data += sizeof(struct ip); 849 n->m_next = m; 850 m = n; 851 m->m_len = optlen + sizeof(struct ip); 852 m->m_data += max_linkhdr; 853 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 854 } else { 855 m->m_data -= optlen; 856 m->m_len += optlen; 857 m->m_pkthdr.len += optlen; 858 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 859 } 860 ip = mtod(m, struct ip *); 861 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 862 *phlen = sizeof(struct ip) + optlen; 863 ip->ip_len += optlen; 864 return (m); 865 } 866 867 /* 868 * Copy options from ip to jp, 869 * omitting those not copied during fragmentation. 870 */ 871 int 872 ip_optcopy(ip, jp) 873 struct ip *ip, *jp; 874 { 875 u_char *cp, *dp; 876 int opt, optlen, cnt; 877 878 cp = (u_char *)(ip + 1); 879 dp = (u_char *)(jp + 1); 880 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 881 for (; cnt > 0; cnt -= optlen, cp += optlen) { 882 opt = cp[0]; 883 if (opt == IPOPT_EOL) 884 break; 885 if (opt == IPOPT_NOP) { 886 /* Preserve for IP mcast tunnel's LSRR alignment. */ 887 *dp++ = IPOPT_NOP; 888 optlen = 1; 889 continue; 890 } 891 #ifdef DIAGNOSTIC 892 if (cnt < IPOPT_OLEN + sizeof(*cp)) 893 panic("malformed IPv4 option passed to ip_optcopy"); 894 #endif 895 optlen = cp[IPOPT_OLEN]; 896 #ifdef DIAGNOSTIC 897 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 898 panic("malformed IPv4 option passed to ip_optcopy"); 899 #endif 900 /* bogus lengths should have been caught by ip_dooptions */ 901 if (optlen > cnt) 902 optlen = cnt; 903 if (IPOPT_COPIED(opt)) { 904 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 905 dp += optlen; 906 } 907 } 908 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 909 *dp++ = IPOPT_EOL; 910 return (optlen); 911 } 912 913 /* 914 * IP socket option processing. 915 */ 916 int 917 ip_ctloutput(op, so, level, optname, mp) 918 int op; 919 struct socket *so; 920 int level, optname; 921 struct mbuf **mp; 922 { 923 struct inpcb *inp = sotoinpcb(so); 924 struct mbuf *m = *mp; 925 int optval = 0; 926 int error = 0; 927 #ifdef IPSEC 928 #ifdef __NetBSD__ 929 struct proc *p = curproc; /*XXX*/ 930 #endif 931 #endif 932 933 if (level != IPPROTO_IP) { 934 error = EINVAL; 935 if (op == PRCO_SETOPT && *mp) 936 (void) m_free(*mp); 937 } else switch (op) { 938 939 case PRCO_SETOPT: 940 switch (optname) { 941 case IP_OPTIONS: 942 #ifdef notyet 943 case IP_RETOPTS: 944 return (ip_pcbopts(optname, &inp->inp_options, m)); 945 #else 946 return (ip_pcbopts(&inp->inp_options, m)); 947 #endif 948 949 case IP_TOS: 950 case IP_TTL: 951 case IP_RECVOPTS: 952 case IP_RECVRETOPTS: 953 case IP_RECVDSTADDR: 954 case IP_RECVIF: 955 if (m == NULL || m->m_len != sizeof(int)) 956 error = EINVAL; 957 else { 958 optval = *mtod(m, int *); 959 switch (optname) { 960 961 case IP_TOS: 962 inp->inp_ip.ip_tos = optval; 963 break; 964 965 case IP_TTL: 966 inp->inp_ip.ip_ttl = optval; 967 break; 968 #define OPTSET(bit) \ 969 if (optval) \ 970 inp->inp_flags |= bit; \ 971 else \ 972 inp->inp_flags &= ~bit; 973 974 case IP_RECVOPTS: 975 OPTSET(INP_RECVOPTS); 976 break; 977 978 case IP_RECVRETOPTS: 979 OPTSET(INP_RECVRETOPTS); 980 break; 981 982 case IP_RECVDSTADDR: 983 OPTSET(INP_RECVDSTADDR); 984 break; 985 986 case IP_RECVIF: 987 OPTSET(INP_RECVIF); 988 break; 989 } 990 } 991 break; 992 #undef OPTSET 993 994 case IP_MULTICAST_IF: 995 case IP_MULTICAST_TTL: 996 case IP_MULTICAST_LOOP: 997 case IP_ADD_MEMBERSHIP: 998 case IP_DROP_MEMBERSHIP: 999 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1000 break; 1001 1002 case IP_PORTRANGE: 1003 if (m == 0 || m->m_len != sizeof(int)) 1004 error = EINVAL; 1005 else { 1006 optval = *mtod(m, int *); 1007 1008 switch (optval) { 1009 1010 case IP_PORTRANGE_DEFAULT: 1011 case IP_PORTRANGE_HIGH: 1012 inp->inp_flags &= ~(INP_LOWPORT); 1013 break; 1014 1015 case IP_PORTRANGE_LOW: 1016 inp->inp_flags |= INP_LOWPORT; 1017 break; 1018 1019 default: 1020 error = EINVAL; 1021 break; 1022 } 1023 } 1024 break; 1025 1026 #ifdef IPSEC 1027 case IP_IPSEC_POLICY: 1028 { 1029 caddr_t req = NULL; 1030 size_t len = 0; 1031 int priv = 0; 1032 1033 #ifdef __NetBSD__ 1034 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1035 priv = 0; 1036 else 1037 priv = 1; 1038 #else 1039 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1040 #endif 1041 if (m) { 1042 req = mtod(m, caddr_t); 1043 len = m->m_len; 1044 } 1045 error = ipsec4_set_policy(inp, optname, req, len, priv); 1046 break; 1047 } 1048 #endif /*IPSEC*/ 1049 1050 default: 1051 error = ENOPROTOOPT; 1052 break; 1053 } 1054 if (m) 1055 (void)m_free(m); 1056 break; 1057 1058 case PRCO_GETOPT: 1059 switch (optname) { 1060 case IP_OPTIONS: 1061 case IP_RETOPTS: 1062 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1063 if (inp->inp_options) { 1064 m->m_len = inp->inp_options->m_len; 1065 bcopy(mtod(inp->inp_options, caddr_t), 1066 mtod(m, caddr_t), (unsigned)m->m_len); 1067 } else 1068 m->m_len = 0; 1069 break; 1070 1071 case IP_TOS: 1072 case IP_TTL: 1073 case IP_RECVOPTS: 1074 case IP_RECVRETOPTS: 1075 case IP_RECVDSTADDR: 1076 case IP_RECVIF: 1077 case IP_ERRORMTU: 1078 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1079 m->m_len = sizeof(int); 1080 switch (optname) { 1081 1082 case IP_TOS: 1083 optval = inp->inp_ip.ip_tos; 1084 break; 1085 1086 case IP_TTL: 1087 optval = inp->inp_ip.ip_ttl; 1088 break; 1089 1090 case IP_ERRORMTU: 1091 optval = inp->inp_errormtu; 1092 break; 1093 1094 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1095 1096 case IP_RECVOPTS: 1097 optval = OPTBIT(INP_RECVOPTS); 1098 break; 1099 1100 case IP_RECVRETOPTS: 1101 optval = OPTBIT(INP_RECVRETOPTS); 1102 break; 1103 1104 case IP_RECVDSTADDR: 1105 optval = OPTBIT(INP_RECVDSTADDR); 1106 break; 1107 1108 case IP_RECVIF: 1109 optval = OPTBIT(INP_RECVIF); 1110 break; 1111 } 1112 *mtod(m, int *) = optval; 1113 break; 1114 1115 #ifdef IPSEC 1116 case IP_IPSEC_POLICY: 1117 { 1118 caddr_t req = NULL; 1119 size_t len = 0; 1120 1121 if (m) { 1122 req = mtod(m, caddr_t); 1123 len = m->m_len; 1124 } 1125 error = ipsec4_get_policy(inp, req, len, mp); 1126 break; 1127 } 1128 #endif /*IPSEC*/ 1129 1130 case IP_MULTICAST_IF: 1131 case IP_MULTICAST_TTL: 1132 case IP_MULTICAST_LOOP: 1133 case IP_ADD_MEMBERSHIP: 1134 case IP_DROP_MEMBERSHIP: 1135 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1136 break; 1137 1138 case IP_PORTRANGE: 1139 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1140 m->m_len = sizeof(int); 1141 1142 if (inp->inp_flags & INP_LOWPORT) 1143 optval = IP_PORTRANGE_LOW; 1144 else 1145 optval = IP_PORTRANGE_DEFAULT; 1146 1147 *mtod(m, int *) = optval; 1148 break; 1149 1150 default: 1151 error = ENOPROTOOPT; 1152 break; 1153 } 1154 break; 1155 } 1156 return (error); 1157 } 1158 1159 /* 1160 * Set up IP options in pcb for insertion in output packets. 1161 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1162 * with destination address if source routed. 1163 */ 1164 int 1165 #ifdef notyet 1166 ip_pcbopts(optname, pcbopt, m) 1167 int optname; 1168 #else 1169 ip_pcbopts(pcbopt, m) 1170 #endif 1171 struct mbuf **pcbopt; 1172 struct mbuf *m; 1173 { 1174 int cnt, optlen; 1175 u_char *cp; 1176 u_char opt; 1177 1178 /* turn off any old options */ 1179 if (*pcbopt) 1180 (void)m_free(*pcbopt); 1181 *pcbopt = 0; 1182 if (m == (struct mbuf *)0 || m->m_len == 0) { 1183 /* 1184 * Only turning off any previous options. 1185 */ 1186 if (m) 1187 (void)m_free(m); 1188 return (0); 1189 } 1190 1191 #ifndef __vax__ 1192 if (m->m_len % sizeof(int32_t)) 1193 goto bad; 1194 #endif 1195 /* 1196 * IP first-hop destination address will be stored before 1197 * actual options; move other options back 1198 * and clear it when none present. 1199 */ 1200 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1201 goto bad; 1202 cnt = m->m_len; 1203 m->m_len += sizeof(struct in_addr); 1204 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1205 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1206 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1207 1208 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1209 opt = cp[IPOPT_OPTVAL]; 1210 if (opt == IPOPT_EOL) 1211 break; 1212 if (opt == IPOPT_NOP) 1213 optlen = 1; 1214 else { 1215 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1216 goto bad; 1217 optlen = cp[IPOPT_OLEN]; 1218 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1219 goto bad; 1220 } 1221 switch (opt) { 1222 1223 default: 1224 break; 1225 1226 case IPOPT_LSRR: 1227 case IPOPT_SSRR: 1228 /* 1229 * user process specifies route as: 1230 * ->A->B->C->D 1231 * D must be our final destination (but we can't 1232 * check that since we may not have connected yet). 1233 * A is first hop destination, which doesn't appear in 1234 * actual IP option, but is stored before the options. 1235 */ 1236 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1237 goto bad; 1238 m->m_len -= sizeof(struct in_addr); 1239 cnt -= sizeof(struct in_addr); 1240 optlen -= sizeof(struct in_addr); 1241 cp[IPOPT_OLEN] = optlen; 1242 /* 1243 * Move first hop before start of options. 1244 */ 1245 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1246 sizeof(struct in_addr)); 1247 /* 1248 * Then copy rest of options back 1249 * to close up the deleted entry. 1250 */ 1251 memmove(&cp[IPOPT_OFFSET+1], 1252 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1253 (unsigned)cnt + sizeof(struct in_addr)); 1254 break; 1255 } 1256 } 1257 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1258 goto bad; 1259 *pcbopt = m; 1260 return (0); 1261 1262 bad: 1263 (void)m_free(m); 1264 return (EINVAL); 1265 } 1266 1267 /* 1268 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1269 */ 1270 static struct ifnet * 1271 ip_multicast_if(a, ifindexp) 1272 struct in_addr *a; 1273 int *ifindexp; 1274 { 1275 int ifindex; 1276 struct ifnet *ifp; 1277 1278 if (ifindexp) 1279 *ifindexp = 0; 1280 if (ntohl(a->s_addr) >> 24 == 0) { 1281 ifindex = ntohl(a->s_addr) & 0xffffff; 1282 if (ifindex < 0 || if_index < ifindex) 1283 return NULL; 1284 ifp = ifindex2ifnet[ifindex]; 1285 if (ifindexp) 1286 *ifindexp = ifindex; 1287 } else { 1288 INADDR_TO_IFP(*a, ifp); 1289 } 1290 return ifp; 1291 } 1292 1293 /* 1294 * Set the IP multicast options in response to user setsockopt(). 1295 */ 1296 int 1297 ip_setmoptions(optname, imop, m) 1298 int optname; 1299 struct ip_moptions **imop; 1300 struct mbuf *m; 1301 { 1302 int error = 0; 1303 u_char loop; 1304 int i; 1305 struct in_addr addr; 1306 struct ip_mreq *mreq; 1307 struct ifnet *ifp; 1308 struct ip_moptions *imo = *imop; 1309 struct route ro; 1310 struct sockaddr_in *dst; 1311 int ifindex; 1312 1313 if (imo == NULL) { 1314 /* 1315 * No multicast option buffer attached to the pcb; 1316 * allocate one and initialize to default values. 1317 */ 1318 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1319 M_WAITOK); 1320 1321 if (imo == NULL) 1322 return (ENOBUFS); 1323 *imop = imo; 1324 imo->imo_multicast_ifp = NULL; 1325 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1326 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1327 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1328 imo->imo_num_memberships = 0; 1329 } 1330 1331 switch (optname) { 1332 1333 case IP_MULTICAST_IF: 1334 /* 1335 * Select the interface for outgoing multicast packets. 1336 */ 1337 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1338 error = EINVAL; 1339 break; 1340 } 1341 addr = *(mtod(m, struct in_addr *)); 1342 /* 1343 * INADDR_ANY is used to remove a previous selection. 1344 * When no interface is selected, a default one is 1345 * chosen every time a multicast packet is sent. 1346 */ 1347 if (in_nullhost(addr)) { 1348 imo->imo_multicast_ifp = NULL; 1349 break; 1350 } 1351 /* 1352 * The selected interface is identified by its local 1353 * IP address. Find the interface and confirm that 1354 * it supports multicasting. 1355 */ 1356 ifp = ip_multicast_if(&addr, &ifindex); 1357 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1358 error = EADDRNOTAVAIL; 1359 break; 1360 } 1361 imo->imo_multicast_ifp = ifp; 1362 if (ifindex) 1363 imo->imo_multicast_addr = addr; 1364 else 1365 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1366 break; 1367 1368 case IP_MULTICAST_TTL: 1369 /* 1370 * Set the IP time-to-live for outgoing multicast packets. 1371 */ 1372 if (m == NULL || m->m_len != 1) { 1373 error = EINVAL; 1374 break; 1375 } 1376 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1377 break; 1378 1379 case IP_MULTICAST_LOOP: 1380 /* 1381 * Set the loopback flag for outgoing multicast packets. 1382 * Must be zero or one. 1383 */ 1384 if (m == NULL || m->m_len != 1 || 1385 (loop = *(mtod(m, u_char *))) > 1) { 1386 error = EINVAL; 1387 break; 1388 } 1389 imo->imo_multicast_loop = loop; 1390 break; 1391 1392 case IP_ADD_MEMBERSHIP: 1393 /* 1394 * Add a multicast group membership. 1395 * Group must be a valid IP multicast address. 1396 */ 1397 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1398 error = EINVAL; 1399 break; 1400 } 1401 mreq = mtod(m, struct ip_mreq *); 1402 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1403 error = EINVAL; 1404 break; 1405 } 1406 /* 1407 * If no interface address was provided, use the interface of 1408 * the route to the given multicast address. 1409 */ 1410 if (in_nullhost(mreq->imr_interface)) { 1411 bzero((caddr_t)&ro, sizeof(ro)); 1412 ro.ro_rt = NULL; 1413 dst = satosin(&ro.ro_dst); 1414 dst->sin_len = sizeof(*dst); 1415 dst->sin_family = AF_INET; 1416 dst->sin_addr = mreq->imr_multiaddr; 1417 rtalloc(&ro); 1418 if (ro.ro_rt == NULL) { 1419 error = EADDRNOTAVAIL; 1420 break; 1421 } 1422 ifp = ro.ro_rt->rt_ifp; 1423 rtfree(ro.ro_rt); 1424 } else { 1425 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1426 } 1427 /* 1428 * See if we found an interface, and confirm that it 1429 * supports multicast. 1430 */ 1431 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1432 error = EADDRNOTAVAIL; 1433 break; 1434 } 1435 /* 1436 * See if the membership already exists or if all the 1437 * membership slots are full. 1438 */ 1439 for (i = 0; i < imo->imo_num_memberships; ++i) { 1440 if (imo->imo_membership[i]->inm_ifp == ifp && 1441 in_hosteq(imo->imo_membership[i]->inm_addr, 1442 mreq->imr_multiaddr)) 1443 break; 1444 } 1445 if (i < imo->imo_num_memberships) { 1446 error = EADDRINUSE; 1447 break; 1448 } 1449 if (i == IP_MAX_MEMBERSHIPS) { 1450 error = ETOOMANYREFS; 1451 break; 1452 } 1453 /* 1454 * Everything looks good; add a new record to the multicast 1455 * address list for the given interface. 1456 */ 1457 if ((imo->imo_membership[i] = 1458 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1459 error = ENOBUFS; 1460 break; 1461 } 1462 ++imo->imo_num_memberships; 1463 break; 1464 1465 case IP_DROP_MEMBERSHIP: 1466 /* 1467 * Drop a multicast group membership. 1468 * Group must be a valid IP multicast address. 1469 */ 1470 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1471 error = EINVAL; 1472 break; 1473 } 1474 mreq = mtod(m, struct ip_mreq *); 1475 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1476 error = EINVAL; 1477 break; 1478 } 1479 /* 1480 * If an interface address was specified, get a pointer 1481 * to its ifnet structure. 1482 */ 1483 if (in_nullhost(mreq->imr_interface)) 1484 ifp = NULL; 1485 else { 1486 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1487 if (ifp == NULL) { 1488 error = EADDRNOTAVAIL; 1489 break; 1490 } 1491 } 1492 /* 1493 * Find the membership in the membership array. 1494 */ 1495 for (i = 0; i < imo->imo_num_memberships; ++i) { 1496 if ((ifp == NULL || 1497 imo->imo_membership[i]->inm_ifp == ifp) && 1498 in_hosteq(imo->imo_membership[i]->inm_addr, 1499 mreq->imr_multiaddr)) 1500 break; 1501 } 1502 if (i == imo->imo_num_memberships) { 1503 error = EADDRNOTAVAIL; 1504 break; 1505 } 1506 /* 1507 * Give up the multicast address record to which the 1508 * membership points. 1509 */ 1510 in_delmulti(imo->imo_membership[i]); 1511 /* 1512 * Remove the gap in the membership array. 1513 */ 1514 for (++i; i < imo->imo_num_memberships; ++i) 1515 imo->imo_membership[i-1] = imo->imo_membership[i]; 1516 --imo->imo_num_memberships; 1517 break; 1518 1519 default: 1520 error = EOPNOTSUPP; 1521 break; 1522 } 1523 1524 /* 1525 * If all options have default values, no need to keep the mbuf. 1526 */ 1527 if (imo->imo_multicast_ifp == NULL && 1528 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1529 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1530 imo->imo_num_memberships == 0) { 1531 free(*imop, M_IPMOPTS); 1532 *imop = NULL; 1533 } 1534 1535 return (error); 1536 } 1537 1538 /* 1539 * Return the IP multicast options in response to user getsockopt(). 1540 */ 1541 int 1542 ip_getmoptions(optname, imo, mp) 1543 int optname; 1544 struct ip_moptions *imo; 1545 struct mbuf **mp; 1546 { 1547 u_char *ttl; 1548 u_char *loop; 1549 struct in_addr *addr; 1550 struct in_ifaddr *ia; 1551 1552 *mp = m_get(M_WAIT, MT_SOOPTS); 1553 1554 switch (optname) { 1555 1556 case IP_MULTICAST_IF: 1557 addr = mtod(*mp, struct in_addr *); 1558 (*mp)->m_len = sizeof(struct in_addr); 1559 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1560 *addr = zeroin_addr; 1561 else if (imo->imo_multicast_addr.s_addr) { 1562 /* return the value user has set */ 1563 *addr = imo->imo_multicast_addr; 1564 } else { 1565 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1566 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1567 } 1568 return (0); 1569 1570 case IP_MULTICAST_TTL: 1571 ttl = mtod(*mp, u_char *); 1572 (*mp)->m_len = 1; 1573 *ttl = imo ? imo->imo_multicast_ttl 1574 : IP_DEFAULT_MULTICAST_TTL; 1575 return (0); 1576 1577 case IP_MULTICAST_LOOP: 1578 loop = mtod(*mp, u_char *); 1579 (*mp)->m_len = 1; 1580 *loop = imo ? imo->imo_multicast_loop 1581 : IP_DEFAULT_MULTICAST_LOOP; 1582 return (0); 1583 1584 default: 1585 return (EOPNOTSUPP); 1586 } 1587 } 1588 1589 /* 1590 * Discard the IP multicast options. 1591 */ 1592 void 1593 ip_freemoptions(imo) 1594 struct ip_moptions *imo; 1595 { 1596 int i; 1597 1598 if (imo != NULL) { 1599 for (i = 0; i < imo->imo_num_memberships; ++i) 1600 in_delmulti(imo->imo_membership[i]); 1601 free(imo, M_IPMOPTS); 1602 } 1603 } 1604 1605 /* 1606 * Routine called from ip_output() to loop back a copy of an IP multicast 1607 * packet to the input queue of a specified interface. Note that this 1608 * calls the output routine of the loopback "driver", but with an interface 1609 * pointer that might NOT be &loif -- easier than replicating that code here. 1610 */ 1611 static void 1612 ip_mloopback(ifp, m, dst) 1613 struct ifnet *ifp; 1614 struct mbuf *m; 1615 struct sockaddr_in *dst; 1616 { 1617 struct ip *ip; 1618 struct mbuf *copym; 1619 1620 copym = m_copy(m, 0, M_COPYALL); 1621 if (copym != NULL 1622 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1623 copym = m_pullup(copym, sizeof(struct ip)); 1624 if (copym != NULL) { 1625 /* 1626 * We don't bother to fragment if the IP length is greater 1627 * than the interface's MTU. Can this possibly matter? 1628 */ 1629 ip = mtod(copym, struct ip *); 1630 HTONS(ip->ip_len); 1631 HTONS(ip->ip_off); 1632 ip->ip_sum = 0; 1633 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1634 (void) looutput(ifp, copym, sintosa(dst), NULL); 1635 } 1636 } 1637