1 /* $NetBSD: ip_output.c,v 1.91 2002/01/08 10:05:13 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 1.91 2002/01/08 10:05:13 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 if (!ia) { 321 error = EADDRNOTAVAIL; 322 goto bad; 323 } 324 ip->ip_src = ia->ia_addr.sin_addr; 325 } 326 327 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 328 if (inm != NULL && 329 (imo == NULL || imo->imo_multicast_loop)) { 330 /* 331 * If we belong to the destination multicast group 332 * on the outgoing interface, and the caller did not 333 * forbid loopback, loop back a copy. 334 */ 335 ip_mloopback(ifp, m, dst); 336 } 337 #ifdef MROUTING 338 else { 339 /* 340 * If we are acting as a multicast router, perform 341 * multicast forwarding as if the packet had just 342 * arrived on the interface to which we are about 343 * to send. The multicast forwarding function 344 * recursively calls this function, using the 345 * IP_FORWARDING flag to prevent infinite recursion. 346 * 347 * Multicasts that are looped back by ip_mloopback(), 348 * above, will be forwarded by the ip_input() routine, 349 * if necessary. 350 */ 351 extern struct socket *ip_mrouter; 352 353 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 354 if (ip_mforward(m, ifp) != 0) { 355 m_freem(m); 356 goto done; 357 } 358 } 359 } 360 #endif 361 /* 362 * Multicasts with a time-to-live of zero may be looped- 363 * back, above, but must not be transmitted on a network. 364 * Also, multicasts addressed to the loopback interface 365 * are not sent -- the above call to ip_mloopback() will 366 * loop back a copy if this host actually belongs to the 367 * destination group on the loopback interface. 368 */ 369 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 370 m_freem(m); 371 goto done; 372 } 373 374 goto sendit; 375 } 376 #ifndef notdef 377 /* 378 * If source address not specified yet, use address 379 * of outgoing interface. 380 */ 381 if (in_nullhost(ip->ip_src)) 382 ip->ip_src = ia->ia_addr.sin_addr; 383 #endif 384 385 /* 386 * packets with Class-D address as source are not valid per 387 * RFC 1112 388 */ 389 if (IN_MULTICAST(ip->ip_src.s_addr)) { 390 ipstat.ips_odropped++; 391 error = EADDRNOTAVAIL; 392 goto bad; 393 } 394 395 /* 396 * Look for broadcast address and 397 * and verify user is allowed to send 398 * such a packet. 399 */ 400 if (in_broadcast(dst->sin_addr, ifp)) { 401 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 402 error = EADDRNOTAVAIL; 403 goto bad; 404 } 405 if ((flags & IP_ALLOWBROADCAST) == 0) { 406 error = EACCES; 407 goto bad; 408 } 409 /* don't allow broadcast messages to be fragmented */ 410 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 411 error = EMSGSIZE; 412 goto bad; 413 } 414 m->m_flags |= M_BCAST; 415 } else 416 m->m_flags &= ~M_BCAST; 417 418 sendit: 419 /* 420 * If we're doing Path MTU Discovery, we need to set DF unless 421 * the route's MTU is locked. 422 */ 423 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 424 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 425 ip->ip_off |= IP_DF; 426 427 /* 428 * Remember the current ip_len and ip_off, and swap them into 429 * network order. 430 */ 431 ip_len = ip->ip_len; 432 433 HTONS(ip->ip_len); 434 HTONS(ip->ip_off); 435 436 #ifdef IPSEC 437 /* get SP for this packet */ 438 if (so == NULL) 439 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 440 else 441 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 442 443 if (sp == NULL) { 444 ipsecstat.out_inval++; 445 goto bad; 446 } 447 448 error = 0; 449 450 /* check policy */ 451 switch (sp->policy) { 452 case IPSEC_POLICY_DISCARD: 453 /* 454 * This packet is just discarded. 455 */ 456 ipsecstat.out_polvio++; 457 goto bad; 458 459 case IPSEC_POLICY_BYPASS: 460 case IPSEC_POLICY_NONE: 461 /* no need to do IPsec. */ 462 goto skip_ipsec; 463 464 case IPSEC_POLICY_IPSEC: 465 if (sp->req == NULL) { 466 /* XXX should be panic ? */ 467 printf("ip_output: No IPsec request specified.\n"); 468 error = EINVAL; 469 goto bad; 470 } 471 break; 472 473 case IPSEC_POLICY_ENTRUST: 474 default: 475 printf("ip_output: Invalid policy found. %d\n", sp->policy); 476 } 477 478 /* 479 * ipsec4_output() expects ip_len and ip_off in network 480 * order. They have been set to network order above. 481 */ 482 483 { 484 struct ipsec_output_state state; 485 bzero(&state, sizeof(state)); 486 state.m = m; 487 if (flags & IP_ROUTETOIF) { 488 state.ro = &iproute; 489 bzero(&iproute, sizeof(iproute)); 490 } else 491 state.ro = ro; 492 state.dst = (struct sockaddr *)dst; 493 494 /* 495 * We can't defer the checksum of payload data if 496 * we're about to encrypt/authenticate it. 497 * 498 * XXX When we support crypto offloading functions of 499 * XXX network interfaces, we need to reconsider this, 500 * XXX since it's likely that they'll support checksumming, 501 * XXX as well. 502 */ 503 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 504 in_delayed_cksum(m); 505 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 506 } 507 508 error = ipsec4_output(&state, sp, flags); 509 510 m = state.m; 511 if (flags & IP_ROUTETOIF) { 512 /* 513 * if we have tunnel mode SA, we may need to ignore 514 * IP_ROUTETOIF. 515 */ 516 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 517 flags &= ~IP_ROUTETOIF; 518 ro = state.ro; 519 } 520 } else 521 ro = state.ro; 522 dst = (struct sockaddr_in *)state.dst; 523 if (error) { 524 /* mbuf is already reclaimed in ipsec4_output. */ 525 m0 = NULL; 526 switch (error) { 527 case EHOSTUNREACH: 528 case ENETUNREACH: 529 case EMSGSIZE: 530 case ENOBUFS: 531 case ENOMEM: 532 break; 533 default: 534 printf("ip4_output (ipsec): error code %d\n", error); 535 /*fall through*/ 536 case ENOENT: 537 /* don't show these error codes to the user */ 538 error = 0; 539 break; 540 } 541 goto bad; 542 } 543 544 /* be sure to update variables that are affected by ipsec4_output() */ 545 ip = mtod(m, struct ip *); 546 #ifdef _IP_VHL 547 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 548 #else 549 hlen = ip->ip_hl << 2; 550 #endif 551 ip_len = ntohs(ip->ip_len); 552 553 if (ro->ro_rt == NULL) { 554 if ((flags & IP_ROUTETOIF) == 0) { 555 printf("ip_output: " 556 "can't update route after IPsec processing\n"); 557 error = EHOSTUNREACH; /*XXX*/ 558 goto bad; 559 } 560 } else { 561 /* nobody uses ia beyond here */ 562 if (state.encap) 563 ifp = ro->ro_rt->rt_ifp; 564 } 565 } 566 567 skip_ipsec: 568 #endif /*IPSEC*/ 569 570 #ifdef PFIL_HOOKS 571 /* 572 * Run through list of hooks for output packets. 573 */ 574 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 575 PFIL_OUT)) != 0) 576 goto done; 577 if (m == NULL) 578 goto done; 579 580 ip = mtod(m, struct ip *); 581 #endif /* PFIL_HOOKS */ 582 583 /* 584 * If small enough for mtu of path, can just send directly. 585 */ 586 if (ip_len <= mtu) { 587 #if IFA_STATS 588 /* 589 * search for the source address structure to 590 * maintain output statistics. 591 */ 592 INADDR_TO_IA(ip->ip_src, ia); 593 if (ia) 594 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 595 #endif 596 /* 597 * Always initialize the sum to 0! Some HW assisted 598 * checksumming requires this. 599 */ 600 ip->ip_sum = 0; 601 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 602 603 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 604 605 /* 606 * Perform any checksums that the hardware can't do 607 * for us. 608 * 609 * XXX Does any hardware require the {th,uh}_sum 610 * XXX fields to be 0? 611 */ 612 if (sw_csum & M_CSUM_IPv4) 613 ip->ip_sum = in_cksum(m, hlen); 614 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 615 in_delayed_cksum(m); 616 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 617 } 618 m->m_pkthdr.csum_flags &= ifp->if_csum_flags_tx; 619 620 #ifdef IPSEC 621 /* clean ipsec history once it goes out of the node */ 622 ipsec_delaux(m); 623 #endif 624 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 625 goto done; 626 } 627 628 /* 629 * We can't use HW checksumming if we're about to 630 * to fragment the packet. 631 * 632 * XXX Some hardware can do this. 633 */ 634 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 635 in_delayed_cksum(m); 636 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 637 } 638 639 /* 640 * Too large for interface; fragment if possible. 641 * Must be able to put at least 8 bytes per fragment. 642 * 643 * Note we swap ip_len and ip_off into host order to make 644 * the logic below a little simpler. 645 */ 646 647 NTOHS(ip->ip_len); 648 NTOHS(ip->ip_off); 649 650 if (ip->ip_off & IP_DF) { 651 if (flags & IP_RETURNMTU) 652 *mtu_p = mtu; 653 error = EMSGSIZE; 654 ipstat.ips_cantfrag++; 655 goto bad; 656 } 657 len = (mtu - hlen) &~ 7; 658 if (len < 8) { 659 error = EMSGSIZE; 660 goto bad; 661 } 662 663 { 664 int mhlen, firstlen = len; 665 struct mbuf **mnext = &m->m_nextpkt; 666 int fragments = 0; 667 int s; 668 669 /* 670 * Loop through length of segment after first fragment, 671 * make new header and copy data of each part and link onto chain. 672 */ 673 m0 = m; 674 mhlen = sizeof (struct ip); 675 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 676 MGETHDR(m, M_DONTWAIT, MT_HEADER); 677 if (m == 0) { 678 error = ENOBUFS; 679 ipstat.ips_odropped++; 680 goto sendorfree; 681 } 682 *mnext = m; 683 mnext = &m->m_nextpkt; 684 m->m_data += max_linkhdr; 685 mhip = mtod(m, struct ip *); 686 *mhip = *ip; 687 /* we must inherit MCAST and BCAST flags */ 688 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 689 if (hlen > sizeof (struct ip)) { 690 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 691 mhip->ip_hl = mhlen >> 2; 692 } 693 m->m_len = mhlen; 694 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 695 if (ip->ip_off & IP_MF) 696 mhip->ip_off |= IP_MF; 697 if (off + len >= (u_int16_t)ip->ip_len) 698 len = (u_int16_t)ip->ip_len - off; 699 else 700 mhip->ip_off |= IP_MF; 701 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 702 m->m_next = m_copy(m0, off, len); 703 if (m->m_next == 0) { 704 error = ENOBUFS; /* ??? */ 705 ipstat.ips_odropped++; 706 goto sendorfree; 707 } 708 m->m_pkthdr.len = mhlen + len; 709 m->m_pkthdr.rcvif = (struct ifnet *)0; 710 HTONS(mhip->ip_off); 711 mhip->ip_sum = 0; 712 mhip->ip_sum = in_cksum(m, mhlen); 713 ipstat.ips_ofragments++; 714 fragments++; 715 } 716 /* 717 * Update first fragment by trimming what's been copied out 718 * and updating header, then send each fragment (in order). 719 */ 720 m = m0; 721 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 722 m->m_pkthdr.len = hlen + firstlen; 723 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 724 ip->ip_off |= IP_MF; 725 HTONS(ip->ip_off); 726 ip->ip_sum = 0; 727 ip->ip_sum = in_cksum(m, hlen); 728 sendorfree: 729 /* 730 * If there is no room for all the fragments, don't queue 731 * any of them. 732 */ 733 s = splnet(); 734 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 735 error = ENOBUFS; 736 splx(s); 737 for (m = m0; m; m = m0) { 738 m0 = m->m_nextpkt; 739 m->m_nextpkt = 0; 740 if (error == 0) { 741 #if IFA_STATS 742 /* 743 * search for the source address structure to 744 * maintain output statistics. 745 */ 746 INADDR_TO_IA(ip->ip_src, ia); 747 if (ia) { 748 ia->ia_ifa.ifa_data.ifad_outbytes += 749 ntohs(ip->ip_len); 750 } 751 #endif 752 #ifdef IPSEC 753 /* clean ipsec history once it goes out of the node */ 754 ipsec_delaux(m); 755 #endif 756 error = (*ifp->if_output)(ifp, m, sintosa(dst), 757 ro->ro_rt); 758 } else 759 m_freem(m); 760 } 761 762 if (error == 0) 763 ipstat.ips_fragmented++; 764 } 765 done: 766 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 767 RTFREE(ro->ro_rt); 768 ro->ro_rt = 0; 769 } 770 771 #ifdef IPSEC 772 if (sp != NULL) { 773 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 774 printf("DP ip_output call free SP:%p\n", sp)); 775 key_freesp(sp); 776 } 777 #endif /* IPSEC */ 778 779 return (error); 780 bad: 781 m_freem(m); 782 goto done; 783 } 784 785 /* 786 * Process a delayed payload checksum calculation. 787 */ 788 void 789 in_delayed_cksum(struct mbuf *m) 790 { 791 struct ip *ip; 792 u_int16_t csum, offset; 793 794 ip = mtod(m, struct ip *); 795 offset = ip->ip_hl << 2; 796 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 797 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 798 csum = 0xffff; 799 800 offset += m->m_pkthdr.csum_data; /* checksum offset */ 801 802 if ((offset + sizeof(u_int16_t)) > m->m_len) { 803 /* This happen when ip options were inserted 804 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 805 m->m_len, offset, ip->ip_p); 806 */ 807 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 808 } else 809 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 810 } 811 812 /* 813 * Determine the maximum length of the options to be inserted; 814 * we would far rather allocate too much space rather than too little. 815 */ 816 817 u_int 818 ip_optlen(inp) 819 struct inpcb *inp; 820 { 821 struct mbuf *m = inp->inp_options; 822 823 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 824 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 825 else 826 return 0; 827 } 828 829 830 /* 831 * Insert IP options into preformed packet. 832 * Adjust IP destination as required for IP source routing, 833 * as indicated by a non-zero in_addr at the start of the options. 834 */ 835 static struct mbuf * 836 ip_insertoptions(m, opt, phlen) 837 struct mbuf *m; 838 struct mbuf *opt; 839 int *phlen; 840 { 841 struct ipoption *p = mtod(opt, struct ipoption *); 842 struct mbuf *n; 843 struct ip *ip = mtod(m, struct ip *); 844 unsigned optlen; 845 846 optlen = opt->m_len - sizeof(p->ipopt_dst); 847 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 848 return (m); /* XXX should fail */ 849 if (!in_nullhost(p->ipopt_dst)) 850 ip->ip_dst = p->ipopt_dst; 851 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 852 MGETHDR(n, M_DONTWAIT, MT_HEADER); 853 if (n == 0) 854 return (m); 855 M_COPY_PKTHDR(n, m); 856 m->m_flags &= ~M_PKTHDR; 857 m->m_len -= sizeof(struct ip); 858 m->m_data += sizeof(struct ip); 859 n->m_next = m; 860 m = n; 861 m->m_len = optlen + sizeof(struct ip); 862 m->m_data += max_linkhdr; 863 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 864 } else { 865 m->m_data -= optlen; 866 m->m_len += optlen; 867 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 868 } 869 m->m_pkthdr.len += optlen; 870 ip = mtod(m, struct ip *); 871 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 872 *phlen = sizeof(struct ip) + optlen; 873 ip->ip_len += optlen; 874 return (m); 875 } 876 877 /* 878 * Copy options from ip to jp, 879 * omitting those not copied during fragmentation. 880 */ 881 int 882 ip_optcopy(ip, jp) 883 struct ip *ip, *jp; 884 { 885 u_char *cp, *dp; 886 int opt, optlen, cnt; 887 888 cp = (u_char *)(ip + 1); 889 dp = (u_char *)(jp + 1); 890 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 891 for (; cnt > 0; cnt -= optlen, cp += optlen) { 892 opt = cp[0]; 893 if (opt == IPOPT_EOL) 894 break; 895 if (opt == IPOPT_NOP) { 896 /* Preserve for IP mcast tunnel's LSRR alignment. */ 897 *dp++ = IPOPT_NOP; 898 optlen = 1; 899 continue; 900 } 901 #ifdef DIAGNOSTIC 902 if (cnt < IPOPT_OLEN + sizeof(*cp)) 903 panic("malformed IPv4 option passed to ip_optcopy"); 904 #endif 905 optlen = cp[IPOPT_OLEN]; 906 #ifdef DIAGNOSTIC 907 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 908 panic("malformed IPv4 option passed to ip_optcopy"); 909 #endif 910 /* bogus lengths should have been caught by ip_dooptions */ 911 if (optlen > cnt) 912 optlen = cnt; 913 if (IPOPT_COPIED(opt)) { 914 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 915 dp += optlen; 916 } 917 } 918 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 919 *dp++ = IPOPT_EOL; 920 return (optlen); 921 } 922 923 /* 924 * IP socket option processing. 925 */ 926 int 927 ip_ctloutput(op, so, level, optname, mp) 928 int op; 929 struct socket *so; 930 int level, optname; 931 struct mbuf **mp; 932 { 933 struct inpcb *inp = sotoinpcb(so); 934 struct mbuf *m = *mp; 935 int optval = 0; 936 int error = 0; 937 #ifdef IPSEC 938 #ifdef __NetBSD__ 939 struct proc *p = curproc; /*XXX*/ 940 #endif 941 #endif 942 943 if (level != IPPROTO_IP) { 944 error = EINVAL; 945 if (op == PRCO_SETOPT && *mp) 946 (void) m_free(*mp); 947 } else switch (op) { 948 949 case PRCO_SETOPT: 950 switch (optname) { 951 case IP_OPTIONS: 952 #ifdef notyet 953 case IP_RETOPTS: 954 return (ip_pcbopts(optname, &inp->inp_options, m)); 955 #else 956 return (ip_pcbopts(&inp->inp_options, m)); 957 #endif 958 959 case IP_TOS: 960 case IP_TTL: 961 case IP_RECVOPTS: 962 case IP_RECVRETOPTS: 963 case IP_RECVDSTADDR: 964 case IP_RECVIF: 965 if (m == NULL || m->m_len != sizeof(int)) 966 error = EINVAL; 967 else { 968 optval = *mtod(m, int *); 969 switch (optname) { 970 971 case IP_TOS: 972 inp->inp_ip.ip_tos = optval; 973 break; 974 975 case IP_TTL: 976 inp->inp_ip.ip_ttl = optval; 977 break; 978 #define OPTSET(bit) \ 979 if (optval) \ 980 inp->inp_flags |= bit; \ 981 else \ 982 inp->inp_flags &= ~bit; 983 984 case IP_RECVOPTS: 985 OPTSET(INP_RECVOPTS); 986 break; 987 988 case IP_RECVRETOPTS: 989 OPTSET(INP_RECVRETOPTS); 990 break; 991 992 case IP_RECVDSTADDR: 993 OPTSET(INP_RECVDSTADDR); 994 break; 995 996 case IP_RECVIF: 997 OPTSET(INP_RECVIF); 998 break; 999 } 1000 } 1001 break; 1002 #undef OPTSET 1003 1004 case IP_MULTICAST_IF: 1005 case IP_MULTICAST_TTL: 1006 case IP_MULTICAST_LOOP: 1007 case IP_ADD_MEMBERSHIP: 1008 case IP_DROP_MEMBERSHIP: 1009 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1010 break; 1011 1012 case IP_PORTRANGE: 1013 if (m == 0 || m->m_len != sizeof(int)) 1014 error = EINVAL; 1015 else { 1016 optval = *mtod(m, int *); 1017 1018 switch (optval) { 1019 1020 case IP_PORTRANGE_DEFAULT: 1021 case IP_PORTRANGE_HIGH: 1022 inp->inp_flags &= ~(INP_LOWPORT); 1023 break; 1024 1025 case IP_PORTRANGE_LOW: 1026 inp->inp_flags |= INP_LOWPORT; 1027 break; 1028 1029 default: 1030 error = EINVAL; 1031 break; 1032 } 1033 } 1034 break; 1035 1036 #ifdef IPSEC 1037 case IP_IPSEC_POLICY: 1038 { 1039 caddr_t req = NULL; 1040 size_t len = 0; 1041 int priv = 0; 1042 1043 #ifdef __NetBSD__ 1044 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1045 priv = 0; 1046 else 1047 priv = 1; 1048 #else 1049 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1050 #endif 1051 if (m) { 1052 req = mtod(m, caddr_t); 1053 len = m->m_len; 1054 } 1055 error = ipsec4_set_policy(inp, optname, req, len, priv); 1056 break; 1057 } 1058 #endif /*IPSEC*/ 1059 1060 default: 1061 error = ENOPROTOOPT; 1062 break; 1063 } 1064 if (m) 1065 (void)m_free(m); 1066 break; 1067 1068 case PRCO_GETOPT: 1069 switch (optname) { 1070 case IP_OPTIONS: 1071 case IP_RETOPTS: 1072 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1073 if (inp->inp_options) { 1074 m->m_len = inp->inp_options->m_len; 1075 bcopy(mtod(inp->inp_options, caddr_t), 1076 mtod(m, caddr_t), (unsigned)m->m_len); 1077 } else 1078 m->m_len = 0; 1079 break; 1080 1081 case IP_TOS: 1082 case IP_TTL: 1083 case IP_RECVOPTS: 1084 case IP_RECVRETOPTS: 1085 case IP_RECVDSTADDR: 1086 case IP_RECVIF: 1087 case IP_ERRORMTU: 1088 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1089 m->m_len = sizeof(int); 1090 switch (optname) { 1091 1092 case IP_TOS: 1093 optval = inp->inp_ip.ip_tos; 1094 break; 1095 1096 case IP_TTL: 1097 optval = inp->inp_ip.ip_ttl; 1098 break; 1099 1100 case IP_ERRORMTU: 1101 optval = inp->inp_errormtu; 1102 break; 1103 1104 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1105 1106 case IP_RECVOPTS: 1107 optval = OPTBIT(INP_RECVOPTS); 1108 break; 1109 1110 case IP_RECVRETOPTS: 1111 optval = OPTBIT(INP_RECVRETOPTS); 1112 break; 1113 1114 case IP_RECVDSTADDR: 1115 optval = OPTBIT(INP_RECVDSTADDR); 1116 break; 1117 1118 case IP_RECVIF: 1119 optval = OPTBIT(INP_RECVIF); 1120 break; 1121 } 1122 *mtod(m, int *) = optval; 1123 break; 1124 1125 #ifdef IPSEC 1126 case IP_IPSEC_POLICY: 1127 { 1128 caddr_t req = NULL; 1129 size_t len = 0; 1130 1131 if (m) { 1132 req = mtod(m, caddr_t); 1133 len = m->m_len; 1134 } 1135 error = ipsec4_get_policy(inp, req, len, mp); 1136 break; 1137 } 1138 #endif /*IPSEC*/ 1139 1140 case IP_MULTICAST_IF: 1141 case IP_MULTICAST_TTL: 1142 case IP_MULTICAST_LOOP: 1143 case IP_ADD_MEMBERSHIP: 1144 case IP_DROP_MEMBERSHIP: 1145 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1146 break; 1147 1148 case IP_PORTRANGE: 1149 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1150 m->m_len = sizeof(int); 1151 1152 if (inp->inp_flags & INP_LOWPORT) 1153 optval = IP_PORTRANGE_LOW; 1154 else 1155 optval = IP_PORTRANGE_DEFAULT; 1156 1157 *mtod(m, int *) = optval; 1158 break; 1159 1160 default: 1161 error = ENOPROTOOPT; 1162 break; 1163 } 1164 break; 1165 } 1166 return (error); 1167 } 1168 1169 /* 1170 * Set up IP options in pcb for insertion in output packets. 1171 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1172 * with destination address if source routed. 1173 */ 1174 int 1175 #ifdef notyet 1176 ip_pcbopts(optname, pcbopt, m) 1177 int optname; 1178 #else 1179 ip_pcbopts(pcbopt, m) 1180 #endif 1181 struct mbuf **pcbopt; 1182 struct mbuf *m; 1183 { 1184 int cnt, optlen; 1185 u_char *cp; 1186 u_char opt; 1187 1188 /* turn off any old options */ 1189 if (*pcbopt) 1190 (void)m_free(*pcbopt); 1191 *pcbopt = 0; 1192 if (m == (struct mbuf *)0 || m->m_len == 0) { 1193 /* 1194 * Only turning off any previous options. 1195 */ 1196 if (m) 1197 (void)m_free(m); 1198 return (0); 1199 } 1200 1201 #ifndef __vax__ 1202 if (m->m_len % sizeof(int32_t)) 1203 goto bad; 1204 #endif 1205 /* 1206 * IP first-hop destination address will be stored before 1207 * actual options; move other options back 1208 * and clear it when none present. 1209 */ 1210 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1211 goto bad; 1212 cnt = m->m_len; 1213 m->m_len += sizeof(struct in_addr); 1214 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1215 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1216 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1217 1218 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1219 opt = cp[IPOPT_OPTVAL]; 1220 if (opt == IPOPT_EOL) 1221 break; 1222 if (opt == IPOPT_NOP) 1223 optlen = 1; 1224 else { 1225 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1226 goto bad; 1227 optlen = cp[IPOPT_OLEN]; 1228 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1229 goto bad; 1230 } 1231 switch (opt) { 1232 1233 default: 1234 break; 1235 1236 case IPOPT_LSRR: 1237 case IPOPT_SSRR: 1238 /* 1239 * user process specifies route as: 1240 * ->A->B->C->D 1241 * D must be our final destination (but we can't 1242 * check that since we may not have connected yet). 1243 * A is first hop destination, which doesn't appear in 1244 * actual IP option, but is stored before the options. 1245 */ 1246 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1247 goto bad; 1248 m->m_len -= sizeof(struct in_addr); 1249 cnt -= sizeof(struct in_addr); 1250 optlen -= sizeof(struct in_addr); 1251 cp[IPOPT_OLEN] = optlen; 1252 /* 1253 * Move first hop before start of options. 1254 */ 1255 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1256 sizeof(struct in_addr)); 1257 /* 1258 * Then copy rest of options back 1259 * to close up the deleted entry. 1260 */ 1261 memmove(&cp[IPOPT_OFFSET+1], 1262 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1263 (unsigned)cnt + sizeof(struct in_addr)); 1264 break; 1265 } 1266 } 1267 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1268 goto bad; 1269 *pcbopt = m; 1270 return (0); 1271 1272 bad: 1273 (void)m_free(m); 1274 return (EINVAL); 1275 } 1276 1277 /* 1278 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1279 */ 1280 static struct ifnet * 1281 ip_multicast_if(a, ifindexp) 1282 struct in_addr *a; 1283 int *ifindexp; 1284 { 1285 int ifindex; 1286 struct ifnet *ifp; 1287 1288 if (ifindexp) 1289 *ifindexp = 0; 1290 if (ntohl(a->s_addr) >> 24 == 0) { 1291 ifindex = ntohl(a->s_addr) & 0xffffff; 1292 if (ifindex < 0 || if_index < ifindex) 1293 return NULL; 1294 ifp = ifindex2ifnet[ifindex]; 1295 if (ifindexp) 1296 *ifindexp = ifindex; 1297 } else { 1298 INADDR_TO_IFP(*a, ifp); 1299 } 1300 return ifp; 1301 } 1302 1303 /* 1304 * Set the IP multicast options in response to user setsockopt(). 1305 */ 1306 int 1307 ip_setmoptions(optname, imop, m) 1308 int optname; 1309 struct ip_moptions **imop; 1310 struct mbuf *m; 1311 { 1312 int error = 0; 1313 u_char loop; 1314 int i; 1315 struct in_addr addr; 1316 struct ip_mreq *mreq; 1317 struct ifnet *ifp; 1318 struct ip_moptions *imo = *imop; 1319 struct route ro; 1320 struct sockaddr_in *dst; 1321 int ifindex; 1322 1323 if (imo == NULL) { 1324 /* 1325 * No multicast option buffer attached to the pcb; 1326 * allocate one and initialize to default values. 1327 */ 1328 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1329 M_WAITOK); 1330 1331 if (imo == NULL) 1332 return (ENOBUFS); 1333 *imop = imo; 1334 imo->imo_multicast_ifp = NULL; 1335 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1336 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1337 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1338 imo->imo_num_memberships = 0; 1339 } 1340 1341 switch (optname) { 1342 1343 case IP_MULTICAST_IF: 1344 /* 1345 * Select the interface for outgoing multicast packets. 1346 */ 1347 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1348 error = EINVAL; 1349 break; 1350 } 1351 addr = *(mtod(m, struct in_addr *)); 1352 /* 1353 * INADDR_ANY is used to remove a previous selection. 1354 * When no interface is selected, a default one is 1355 * chosen every time a multicast packet is sent. 1356 */ 1357 if (in_nullhost(addr)) { 1358 imo->imo_multicast_ifp = NULL; 1359 break; 1360 } 1361 /* 1362 * The selected interface is identified by its local 1363 * IP address. Find the interface and confirm that 1364 * it supports multicasting. 1365 */ 1366 ifp = ip_multicast_if(&addr, &ifindex); 1367 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1368 error = EADDRNOTAVAIL; 1369 break; 1370 } 1371 imo->imo_multicast_ifp = ifp; 1372 if (ifindex) 1373 imo->imo_multicast_addr = addr; 1374 else 1375 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1376 break; 1377 1378 case IP_MULTICAST_TTL: 1379 /* 1380 * Set the IP time-to-live for outgoing multicast packets. 1381 */ 1382 if (m == NULL || m->m_len != 1) { 1383 error = EINVAL; 1384 break; 1385 } 1386 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1387 break; 1388 1389 case IP_MULTICAST_LOOP: 1390 /* 1391 * Set the loopback flag for outgoing multicast packets. 1392 * Must be zero or one. 1393 */ 1394 if (m == NULL || m->m_len != 1 || 1395 (loop = *(mtod(m, u_char *))) > 1) { 1396 error = EINVAL; 1397 break; 1398 } 1399 imo->imo_multicast_loop = loop; 1400 break; 1401 1402 case IP_ADD_MEMBERSHIP: 1403 /* 1404 * Add a multicast group membership. 1405 * Group must be a valid IP multicast address. 1406 */ 1407 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1408 error = EINVAL; 1409 break; 1410 } 1411 mreq = mtod(m, struct ip_mreq *); 1412 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1413 error = EINVAL; 1414 break; 1415 } 1416 /* 1417 * If no interface address was provided, use the interface of 1418 * the route to the given multicast address. 1419 */ 1420 if (in_nullhost(mreq->imr_interface)) { 1421 bzero((caddr_t)&ro, sizeof(ro)); 1422 ro.ro_rt = NULL; 1423 dst = satosin(&ro.ro_dst); 1424 dst->sin_len = sizeof(*dst); 1425 dst->sin_family = AF_INET; 1426 dst->sin_addr = mreq->imr_multiaddr; 1427 rtalloc(&ro); 1428 if (ro.ro_rt == NULL) { 1429 error = EADDRNOTAVAIL; 1430 break; 1431 } 1432 ifp = ro.ro_rt->rt_ifp; 1433 rtfree(ro.ro_rt); 1434 } else { 1435 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1436 } 1437 /* 1438 * See if we found an interface, and confirm that it 1439 * supports multicast. 1440 */ 1441 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1442 error = EADDRNOTAVAIL; 1443 break; 1444 } 1445 /* 1446 * See if the membership already exists or if all the 1447 * membership slots are full. 1448 */ 1449 for (i = 0; i < imo->imo_num_memberships; ++i) { 1450 if (imo->imo_membership[i]->inm_ifp == ifp && 1451 in_hosteq(imo->imo_membership[i]->inm_addr, 1452 mreq->imr_multiaddr)) 1453 break; 1454 } 1455 if (i < imo->imo_num_memberships) { 1456 error = EADDRINUSE; 1457 break; 1458 } 1459 if (i == IP_MAX_MEMBERSHIPS) { 1460 error = ETOOMANYREFS; 1461 break; 1462 } 1463 /* 1464 * Everything looks good; add a new record to the multicast 1465 * address list for the given interface. 1466 */ 1467 if ((imo->imo_membership[i] = 1468 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1469 error = ENOBUFS; 1470 break; 1471 } 1472 ++imo->imo_num_memberships; 1473 break; 1474 1475 case IP_DROP_MEMBERSHIP: 1476 /* 1477 * Drop a multicast group membership. 1478 * Group must be a valid IP multicast address. 1479 */ 1480 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1481 error = EINVAL; 1482 break; 1483 } 1484 mreq = mtod(m, struct ip_mreq *); 1485 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1486 error = EINVAL; 1487 break; 1488 } 1489 /* 1490 * If an interface address was specified, get a pointer 1491 * to its ifnet structure. 1492 */ 1493 if (in_nullhost(mreq->imr_interface)) 1494 ifp = NULL; 1495 else { 1496 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1497 if (ifp == NULL) { 1498 error = EADDRNOTAVAIL; 1499 break; 1500 } 1501 } 1502 /* 1503 * Find the membership in the membership array. 1504 */ 1505 for (i = 0; i < imo->imo_num_memberships; ++i) { 1506 if ((ifp == NULL || 1507 imo->imo_membership[i]->inm_ifp == ifp) && 1508 in_hosteq(imo->imo_membership[i]->inm_addr, 1509 mreq->imr_multiaddr)) 1510 break; 1511 } 1512 if (i == imo->imo_num_memberships) { 1513 error = EADDRNOTAVAIL; 1514 break; 1515 } 1516 /* 1517 * Give up the multicast address record to which the 1518 * membership points. 1519 */ 1520 in_delmulti(imo->imo_membership[i]); 1521 /* 1522 * Remove the gap in the membership array. 1523 */ 1524 for (++i; i < imo->imo_num_memberships; ++i) 1525 imo->imo_membership[i-1] = imo->imo_membership[i]; 1526 --imo->imo_num_memberships; 1527 break; 1528 1529 default: 1530 error = EOPNOTSUPP; 1531 break; 1532 } 1533 1534 /* 1535 * If all options have default values, no need to keep the mbuf. 1536 */ 1537 if (imo->imo_multicast_ifp == NULL && 1538 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1539 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1540 imo->imo_num_memberships == 0) { 1541 free(*imop, M_IPMOPTS); 1542 *imop = NULL; 1543 } 1544 1545 return (error); 1546 } 1547 1548 /* 1549 * Return the IP multicast options in response to user getsockopt(). 1550 */ 1551 int 1552 ip_getmoptions(optname, imo, mp) 1553 int optname; 1554 struct ip_moptions *imo; 1555 struct mbuf **mp; 1556 { 1557 u_char *ttl; 1558 u_char *loop; 1559 struct in_addr *addr; 1560 struct in_ifaddr *ia; 1561 1562 *mp = m_get(M_WAIT, MT_SOOPTS); 1563 1564 switch (optname) { 1565 1566 case IP_MULTICAST_IF: 1567 addr = mtod(*mp, struct in_addr *); 1568 (*mp)->m_len = sizeof(struct in_addr); 1569 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1570 *addr = zeroin_addr; 1571 else if (imo->imo_multicast_addr.s_addr) { 1572 /* return the value user has set */ 1573 *addr = imo->imo_multicast_addr; 1574 } else { 1575 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1576 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1577 } 1578 return (0); 1579 1580 case IP_MULTICAST_TTL: 1581 ttl = mtod(*mp, u_char *); 1582 (*mp)->m_len = 1; 1583 *ttl = imo ? imo->imo_multicast_ttl 1584 : IP_DEFAULT_MULTICAST_TTL; 1585 return (0); 1586 1587 case IP_MULTICAST_LOOP: 1588 loop = mtod(*mp, u_char *); 1589 (*mp)->m_len = 1; 1590 *loop = imo ? imo->imo_multicast_loop 1591 : IP_DEFAULT_MULTICAST_LOOP; 1592 return (0); 1593 1594 default: 1595 return (EOPNOTSUPP); 1596 } 1597 } 1598 1599 /* 1600 * Discard the IP multicast options. 1601 */ 1602 void 1603 ip_freemoptions(imo) 1604 struct ip_moptions *imo; 1605 { 1606 int i; 1607 1608 if (imo != NULL) { 1609 for (i = 0; i < imo->imo_num_memberships; ++i) 1610 in_delmulti(imo->imo_membership[i]); 1611 free(imo, M_IPMOPTS); 1612 } 1613 } 1614 1615 /* 1616 * Routine called from ip_output() to loop back a copy of an IP multicast 1617 * packet to the input queue of a specified interface. Note that this 1618 * calls the output routine of the loopback "driver", but with an interface 1619 * pointer that might NOT be &loif -- easier than replicating that code here. 1620 */ 1621 static void 1622 ip_mloopback(ifp, m, dst) 1623 struct ifnet *ifp; 1624 struct mbuf *m; 1625 struct sockaddr_in *dst; 1626 { 1627 struct ip *ip; 1628 struct mbuf *copym; 1629 1630 copym = m_copy(m, 0, M_COPYALL); 1631 if (copym != NULL 1632 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1633 copym = m_pullup(copym, sizeof(struct ip)); 1634 if (copym != NULL) { 1635 /* 1636 * We don't bother to fragment if the IP length is greater 1637 * than the interface's MTU. Can this possibly matter? 1638 */ 1639 ip = mtod(copym, struct ip *); 1640 HTONS(ip->ip_len); 1641 HTONS(ip->ip_off); 1642 ip->ip_sum = 0; 1643 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1644 (void) looutput(ifp, copym, sintosa(dst), NULL); 1645 } 1646 } 1647