1 /* $NetBSD: ip_output.c,v 1.93 2002/01/31 07:45:22 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 1.93 2002/01/31 07:45:22 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 * The address family should also be checked in case of sharing the 239 * cache with IPv6. 240 */ 241 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 242 dst->sin_family != AF_INET || 243 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 244 RTFREE(ro->ro_rt); 245 ro->ro_rt = (struct rtentry *)0; 246 } 247 if (ro->ro_rt == 0) { 248 bzero(dst, sizeof(*dst)); 249 dst->sin_family = AF_INET; 250 dst->sin_len = sizeof(*dst); 251 dst->sin_addr = ip->ip_dst; 252 } 253 /* 254 * If routing to interface only, 255 * short circuit routing lookup. 256 */ 257 if (flags & IP_ROUTETOIF) { 258 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 259 ipstat.ips_noroute++; 260 error = ENETUNREACH; 261 goto bad; 262 } 263 ifp = ia->ia_ifp; 264 mtu = ifp->if_mtu; 265 ip->ip_ttl = 1; 266 } else { 267 if (ro->ro_rt == 0) 268 rtalloc(ro); 269 if (ro->ro_rt == 0) { 270 ipstat.ips_noroute++; 271 error = EHOSTUNREACH; 272 goto bad; 273 } 274 ia = ifatoia(ro->ro_rt->rt_ifa); 275 ifp = ro->ro_rt->rt_ifp; 276 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 277 mtu = ifp->if_mtu; 278 ro->ro_rt->rt_use++; 279 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 280 dst = satosin(ro->ro_rt->rt_gateway); 281 } 282 if (IN_MULTICAST(ip->ip_dst.s_addr) || 283 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 284 struct in_multi *inm; 285 286 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 287 M_BCAST : M_MCAST; 288 /* 289 * IP destination address is multicast. Make sure "dst" 290 * still points to the address in "ro". (It may have been 291 * changed to point to a gateway address, above.) 292 */ 293 dst = satosin(&ro->ro_dst); 294 /* 295 * See if the caller provided any multicast options 296 */ 297 if (imo != NULL) { 298 ip->ip_ttl = imo->imo_multicast_ttl; 299 if (imo->imo_multicast_ifp != NULL) { 300 ifp = imo->imo_multicast_ifp; 301 mtu = ifp->if_mtu; 302 } 303 } else 304 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 305 /* 306 * Confirm that the outgoing interface supports multicast. 307 */ 308 if (((m->m_flags & M_MCAST) && 309 (ifp->if_flags & IFF_MULTICAST) == 0) || 310 ((m->m_flags & M_BCAST) && 311 (ifp->if_flags & IFF_BROADCAST) == 0)) { 312 ipstat.ips_noroute++; 313 error = ENETUNREACH; 314 goto bad; 315 } 316 /* 317 * If source address not specified yet, use an address 318 * of outgoing interface. 319 */ 320 if (in_nullhost(ip->ip_src)) { 321 struct in_ifaddr *ia; 322 323 IFP_TO_IA(ifp, ia); 324 if (!ia) { 325 error = EADDRNOTAVAIL; 326 goto bad; 327 } 328 ip->ip_src = ia->ia_addr.sin_addr; 329 } 330 331 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 332 if (inm != NULL && 333 (imo == NULL || imo->imo_multicast_loop)) { 334 /* 335 * If we belong to the destination multicast group 336 * on the outgoing interface, and the caller did not 337 * forbid loopback, loop back a copy. 338 */ 339 ip_mloopback(ifp, m, dst); 340 } 341 #ifdef MROUTING 342 else { 343 /* 344 * If we are acting as a multicast router, perform 345 * multicast forwarding as if the packet had just 346 * arrived on the interface to which we are about 347 * to send. The multicast forwarding function 348 * recursively calls this function, using the 349 * IP_FORWARDING flag to prevent infinite recursion. 350 * 351 * Multicasts that are looped back by ip_mloopback(), 352 * above, will be forwarded by the ip_input() routine, 353 * if necessary. 354 */ 355 extern struct socket *ip_mrouter; 356 357 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 358 if (ip_mforward(m, ifp) != 0) { 359 m_freem(m); 360 goto done; 361 } 362 } 363 } 364 #endif 365 /* 366 * Multicasts with a time-to-live of zero may be looped- 367 * back, above, but must not be transmitted on a network. 368 * Also, multicasts addressed to the loopback interface 369 * are not sent -- the above call to ip_mloopback() will 370 * loop back a copy if this host actually belongs to the 371 * destination group on the loopback interface. 372 */ 373 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 374 m_freem(m); 375 goto done; 376 } 377 378 goto sendit; 379 } 380 #ifndef notdef 381 /* 382 * If source address not specified yet, use address 383 * of outgoing interface. 384 */ 385 if (in_nullhost(ip->ip_src)) 386 ip->ip_src = ia->ia_addr.sin_addr; 387 #endif 388 389 /* 390 * packets with Class-D address as source are not valid per 391 * RFC 1112 392 */ 393 if (IN_MULTICAST(ip->ip_src.s_addr)) { 394 ipstat.ips_odropped++; 395 error = EADDRNOTAVAIL; 396 goto bad; 397 } 398 399 /* 400 * Look for broadcast address and 401 * and verify user is allowed to send 402 * such a packet. 403 */ 404 if (in_broadcast(dst->sin_addr, ifp)) { 405 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 406 error = EADDRNOTAVAIL; 407 goto bad; 408 } 409 if ((flags & IP_ALLOWBROADCAST) == 0) { 410 error = EACCES; 411 goto bad; 412 } 413 /* don't allow broadcast messages to be fragmented */ 414 if ((u_int16_t)ip->ip_len > ifp->if_mtu) { 415 error = EMSGSIZE; 416 goto bad; 417 } 418 m->m_flags |= M_BCAST; 419 } else 420 m->m_flags &= ~M_BCAST; 421 422 sendit: 423 /* 424 * If we're doing Path MTU Discovery, we need to set DF unless 425 * the route's MTU is locked. 426 */ 427 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 428 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 429 ip->ip_off |= IP_DF; 430 431 /* 432 * Remember the current ip_len and ip_off, and swap them into 433 * network order. 434 */ 435 ip_len = ip->ip_len; 436 437 HTONS(ip->ip_len); 438 HTONS(ip->ip_off); 439 440 #ifdef IPSEC 441 /* get SP for this packet */ 442 if (so == NULL) 443 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 444 else 445 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 446 447 if (sp == NULL) { 448 ipsecstat.out_inval++; 449 goto bad; 450 } 451 452 error = 0; 453 454 /* check policy */ 455 switch (sp->policy) { 456 case IPSEC_POLICY_DISCARD: 457 /* 458 * This packet is just discarded. 459 */ 460 ipsecstat.out_polvio++; 461 goto bad; 462 463 case IPSEC_POLICY_BYPASS: 464 case IPSEC_POLICY_NONE: 465 /* no need to do IPsec. */ 466 goto skip_ipsec; 467 468 case IPSEC_POLICY_IPSEC: 469 if (sp->req == NULL) { 470 /* XXX should be panic ? */ 471 printf("ip_output: No IPsec request specified.\n"); 472 error = EINVAL; 473 goto bad; 474 } 475 break; 476 477 case IPSEC_POLICY_ENTRUST: 478 default: 479 printf("ip_output: Invalid policy found. %d\n", sp->policy); 480 } 481 482 /* 483 * ipsec4_output() expects ip_len and ip_off in network 484 * order. They have been set to network order above. 485 */ 486 487 { 488 struct ipsec_output_state state; 489 bzero(&state, sizeof(state)); 490 state.m = m; 491 if (flags & IP_ROUTETOIF) { 492 state.ro = &iproute; 493 bzero(&iproute, sizeof(iproute)); 494 } else 495 state.ro = ro; 496 state.dst = (struct sockaddr *)dst; 497 498 /* 499 * We can't defer the checksum of payload data if 500 * we're about to encrypt/authenticate it. 501 * 502 * XXX When we support crypto offloading functions of 503 * XXX network interfaces, we need to reconsider this, 504 * XXX since it's likely that they'll support checksumming, 505 * XXX as well. 506 */ 507 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 508 in_delayed_cksum(m); 509 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 510 } 511 512 error = ipsec4_output(&state, sp, flags); 513 514 m = state.m; 515 if (flags & IP_ROUTETOIF) { 516 /* 517 * if we have tunnel mode SA, we may need to ignore 518 * IP_ROUTETOIF. 519 */ 520 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 521 flags &= ~IP_ROUTETOIF; 522 ro = state.ro; 523 } 524 } else 525 ro = state.ro; 526 dst = (struct sockaddr_in *)state.dst; 527 if (error) { 528 /* mbuf is already reclaimed in ipsec4_output. */ 529 m0 = NULL; 530 switch (error) { 531 case EHOSTUNREACH: 532 case ENETUNREACH: 533 case EMSGSIZE: 534 case ENOBUFS: 535 case ENOMEM: 536 break; 537 default: 538 printf("ip4_output (ipsec): error code %d\n", error); 539 /*fall through*/ 540 case ENOENT: 541 /* don't show these error codes to the user */ 542 error = 0; 543 break; 544 } 545 goto bad; 546 } 547 548 /* be sure to update variables that are affected by ipsec4_output() */ 549 ip = mtod(m, struct ip *); 550 #ifdef _IP_VHL 551 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 552 #else 553 hlen = ip->ip_hl << 2; 554 #endif 555 ip_len = ntohs(ip->ip_len); 556 557 if (ro->ro_rt == NULL) { 558 if ((flags & IP_ROUTETOIF) == 0) { 559 printf("ip_output: " 560 "can't update route after IPsec processing\n"); 561 error = EHOSTUNREACH; /*XXX*/ 562 goto bad; 563 } 564 } else { 565 /* nobody uses ia beyond here */ 566 if (state.encap) 567 ifp = ro->ro_rt->rt_ifp; 568 } 569 } 570 571 skip_ipsec: 572 #endif /*IPSEC*/ 573 574 #ifdef PFIL_HOOKS 575 /* 576 * Run through list of hooks for output packets. 577 */ 578 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 579 PFIL_OUT)) != 0) 580 goto done; 581 if (m == NULL) 582 goto done; 583 584 ip = mtod(m, struct ip *); 585 #endif /* PFIL_HOOKS */ 586 587 /* 588 * If small enough for mtu of path, can just send directly. 589 */ 590 if (ip_len <= mtu) { 591 #if IFA_STATS 592 /* 593 * search for the source address structure to 594 * maintain output statistics. 595 */ 596 INADDR_TO_IA(ip->ip_src, ia); 597 if (ia) 598 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 599 #endif 600 /* 601 * Always initialize the sum to 0! Some HW assisted 602 * checksumming requires this. 603 */ 604 ip->ip_sum = 0; 605 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 606 607 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 608 609 /* 610 * Perform any checksums that the hardware can't do 611 * for us. 612 * 613 * XXX Does any hardware require the {th,uh}_sum 614 * XXX fields to be 0? 615 */ 616 if (sw_csum & M_CSUM_IPv4) 617 ip->ip_sum = in_cksum(m, hlen); 618 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 619 in_delayed_cksum(m); 620 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 621 } 622 m->m_pkthdr.csum_flags &= ifp->if_csum_flags_tx; 623 624 #ifdef IPSEC 625 /* clean ipsec history once it goes out of the node */ 626 ipsec_delaux(m); 627 #endif 628 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 629 goto done; 630 } 631 632 /* 633 * We can't use HW checksumming if we're about to 634 * to fragment the packet. 635 * 636 * XXX Some hardware can do this. 637 */ 638 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 639 in_delayed_cksum(m); 640 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 641 } 642 643 /* 644 * Too large for interface; fragment if possible. 645 * Must be able to put at least 8 bytes per fragment. 646 * 647 * Note we swap ip_len and ip_off into host order to make 648 * the logic below a little simpler. 649 */ 650 651 NTOHS(ip->ip_len); 652 NTOHS(ip->ip_off); 653 654 if (ip->ip_off & IP_DF) { 655 if (flags & IP_RETURNMTU) 656 *mtu_p = mtu; 657 error = EMSGSIZE; 658 ipstat.ips_cantfrag++; 659 goto bad; 660 } 661 len = (mtu - hlen) &~ 7; 662 if (len < 8) { 663 error = EMSGSIZE; 664 goto bad; 665 } 666 667 { 668 int mhlen, firstlen = len; 669 struct mbuf **mnext = &m->m_nextpkt; 670 int fragments = 0; 671 int s; 672 673 /* 674 * Loop through length of segment after first fragment, 675 * make new header and copy data of each part and link onto chain. 676 */ 677 m0 = m; 678 mhlen = sizeof (struct ip); 679 for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len) { 680 MGETHDR(m, M_DONTWAIT, MT_HEADER); 681 if (m == 0) { 682 error = ENOBUFS; 683 ipstat.ips_odropped++; 684 goto sendorfree; 685 } 686 *mnext = m; 687 mnext = &m->m_nextpkt; 688 m->m_data += max_linkhdr; 689 mhip = mtod(m, struct ip *); 690 *mhip = *ip; 691 /* we must inherit MCAST and BCAST flags */ 692 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 693 if (hlen > sizeof (struct ip)) { 694 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 695 mhip->ip_hl = mhlen >> 2; 696 } 697 m->m_len = mhlen; 698 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 699 if (ip->ip_off & IP_MF) 700 mhip->ip_off |= IP_MF; 701 if (off + len >= (u_int16_t)ip->ip_len) 702 len = (u_int16_t)ip->ip_len - off; 703 else 704 mhip->ip_off |= IP_MF; 705 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 706 m->m_next = m_copy(m0, off, len); 707 if (m->m_next == 0) { 708 error = ENOBUFS; /* ??? */ 709 ipstat.ips_odropped++; 710 goto sendorfree; 711 } 712 m->m_pkthdr.len = mhlen + len; 713 m->m_pkthdr.rcvif = (struct ifnet *)0; 714 HTONS(mhip->ip_off); 715 mhip->ip_sum = 0; 716 mhip->ip_sum = in_cksum(m, mhlen); 717 ipstat.ips_ofragments++; 718 fragments++; 719 } 720 /* 721 * Update first fragment by trimming what's been copied out 722 * and updating header, then send each fragment (in order). 723 */ 724 m = m0; 725 m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len); 726 m->m_pkthdr.len = hlen + firstlen; 727 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 728 ip->ip_off |= IP_MF; 729 HTONS(ip->ip_off); 730 ip->ip_sum = 0; 731 ip->ip_sum = in_cksum(m, hlen); 732 sendorfree: 733 /* 734 * If there is no room for all the fragments, don't queue 735 * any of them. 736 */ 737 s = splnet(); 738 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 739 error = ENOBUFS; 740 splx(s); 741 for (m = m0; m; m = m0) { 742 m0 = m->m_nextpkt; 743 m->m_nextpkt = 0; 744 if (error == 0) { 745 #if IFA_STATS 746 /* 747 * search for the source address structure to 748 * maintain output statistics. 749 */ 750 INADDR_TO_IA(ip->ip_src, ia); 751 if (ia) { 752 ia->ia_ifa.ifa_data.ifad_outbytes += 753 ntohs(ip->ip_len); 754 } 755 #endif 756 #ifdef IPSEC 757 /* clean ipsec history once it goes out of the node */ 758 ipsec_delaux(m); 759 #endif 760 error = (*ifp->if_output)(ifp, m, sintosa(dst), 761 ro->ro_rt); 762 } else 763 m_freem(m); 764 } 765 766 if (error == 0) 767 ipstat.ips_fragmented++; 768 } 769 done: 770 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 771 RTFREE(ro->ro_rt); 772 ro->ro_rt = 0; 773 } 774 775 #ifdef IPSEC 776 if (sp != NULL) { 777 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 778 printf("DP ip_output call free SP:%p\n", sp)); 779 key_freesp(sp); 780 } 781 #endif /* IPSEC */ 782 783 return (error); 784 bad: 785 m_freem(m); 786 goto done; 787 } 788 789 /* 790 * Process a delayed payload checksum calculation. 791 */ 792 void 793 in_delayed_cksum(struct mbuf *m) 794 { 795 struct ip *ip; 796 u_int16_t csum, offset; 797 798 ip = mtod(m, struct ip *); 799 offset = ip->ip_hl << 2; 800 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 801 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 802 csum = 0xffff; 803 804 offset += m->m_pkthdr.csum_data; /* checksum offset */ 805 806 if ((offset + sizeof(u_int16_t)) > m->m_len) { 807 /* This happen when ip options were inserted 808 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 809 m->m_len, offset, ip->ip_p); 810 */ 811 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 812 } else 813 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 814 } 815 816 /* 817 * Determine the maximum length of the options to be inserted; 818 * we would far rather allocate too much space rather than too little. 819 */ 820 821 u_int 822 ip_optlen(inp) 823 struct inpcb *inp; 824 { 825 struct mbuf *m = inp->inp_options; 826 827 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 828 return(m->m_len - offsetof(struct ipoption, ipopt_dst)); 829 else 830 return 0; 831 } 832 833 834 /* 835 * Insert IP options into preformed packet. 836 * Adjust IP destination as required for IP source routing, 837 * as indicated by a non-zero in_addr at the start of the options. 838 */ 839 static struct mbuf * 840 ip_insertoptions(m, opt, phlen) 841 struct mbuf *m; 842 struct mbuf *opt; 843 int *phlen; 844 { 845 struct ipoption *p = mtod(opt, struct ipoption *); 846 struct mbuf *n; 847 struct ip *ip = mtod(m, struct ip *); 848 unsigned optlen; 849 850 optlen = opt->m_len - sizeof(p->ipopt_dst); 851 if (optlen + (u_int16_t)ip->ip_len > IP_MAXPACKET) 852 return (m); /* XXX should fail */ 853 if (!in_nullhost(p->ipopt_dst)) 854 ip->ip_dst = p->ipopt_dst; 855 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 856 MGETHDR(n, M_DONTWAIT, MT_HEADER); 857 if (n == 0) 858 return (m); 859 M_COPY_PKTHDR(n, m); 860 m->m_flags &= ~M_PKTHDR; 861 m->m_len -= sizeof(struct ip); 862 m->m_data += sizeof(struct ip); 863 n->m_next = m; 864 m = n; 865 m->m_len = optlen + sizeof(struct ip); 866 m->m_data += max_linkhdr; 867 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 868 } else { 869 m->m_data -= optlen; 870 m->m_len += optlen; 871 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 872 } 873 m->m_pkthdr.len += optlen; 874 ip = mtod(m, struct ip *); 875 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 876 *phlen = sizeof(struct ip) + optlen; 877 ip->ip_len += optlen; 878 return (m); 879 } 880 881 /* 882 * Copy options from ip to jp, 883 * omitting those not copied during fragmentation. 884 */ 885 int 886 ip_optcopy(ip, jp) 887 struct ip *ip, *jp; 888 { 889 u_char *cp, *dp; 890 int opt, optlen, cnt; 891 892 cp = (u_char *)(ip + 1); 893 dp = (u_char *)(jp + 1); 894 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 895 for (; cnt > 0; cnt -= optlen, cp += optlen) { 896 opt = cp[0]; 897 if (opt == IPOPT_EOL) 898 break; 899 if (opt == IPOPT_NOP) { 900 /* Preserve for IP mcast tunnel's LSRR alignment. */ 901 *dp++ = IPOPT_NOP; 902 optlen = 1; 903 continue; 904 } 905 #ifdef DIAGNOSTIC 906 if (cnt < IPOPT_OLEN + sizeof(*cp)) 907 panic("malformed IPv4 option passed to ip_optcopy"); 908 #endif 909 optlen = cp[IPOPT_OLEN]; 910 #ifdef DIAGNOSTIC 911 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 912 panic("malformed IPv4 option passed to ip_optcopy"); 913 #endif 914 /* bogus lengths should have been caught by ip_dooptions */ 915 if (optlen > cnt) 916 optlen = cnt; 917 if (IPOPT_COPIED(opt)) { 918 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 919 dp += optlen; 920 } 921 } 922 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 923 *dp++ = IPOPT_EOL; 924 return (optlen); 925 } 926 927 /* 928 * IP socket option processing. 929 */ 930 int 931 ip_ctloutput(op, so, level, optname, mp) 932 int op; 933 struct socket *so; 934 int level, optname; 935 struct mbuf **mp; 936 { 937 struct inpcb *inp = sotoinpcb(so); 938 struct mbuf *m = *mp; 939 int optval = 0; 940 int error = 0; 941 #ifdef IPSEC 942 #ifdef __NetBSD__ 943 struct proc *p = curproc; /*XXX*/ 944 #endif 945 #endif 946 947 if (level != IPPROTO_IP) { 948 error = EINVAL; 949 if (op == PRCO_SETOPT && *mp) 950 (void) m_free(*mp); 951 } else switch (op) { 952 953 case PRCO_SETOPT: 954 switch (optname) { 955 case IP_OPTIONS: 956 #ifdef notyet 957 case IP_RETOPTS: 958 return (ip_pcbopts(optname, &inp->inp_options, m)); 959 #else 960 return (ip_pcbopts(&inp->inp_options, m)); 961 #endif 962 963 case IP_TOS: 964 case IP_TTL: 965 case IP_RECVOPTS: 966 case IP_RECVRETOPTS: 967 case IP_RECVDSTADDR: 968 case IP_RECVIF: 969 if (m == NULL || m->m_len != sizeof(int)) 970 error = EINVAL; 971 else { 972 optval = *mtod(m, int *); 973 switch (optname) { 974 975 case IP_TOS: 976 inp->inp_ip.ip_tos = optval; 977 break; 978 979 case IP_TTL: 980 inp->inp_ip.ip_ttl = optval; 981 break; 982 #define OPTSET(bit) \ 983 if (optval) \ 984 inp->inp_flags |= bit; \ 985 else \ 986 inp->inp_flags &= ~bit; 987 988 case IP_RECVOPTS: 989 OPTSET(INP_RECVOPTS); 990 break; 991 992 case IP_RECVRETOPTS: 993 OPTSET(INP_RECVRETOPTS); 994 break; 995 996 case IP_RECVDSTADDR: 997 OPTSET(INP_RECVDSTADDR); 998 break; 999 1000 case IP_RECVIF: 1001 OPTSET(INP_RECVIF); 1002 break; 1003 } 1004 } 1005 break; 1006 #undef OPTSET 1007 1008 case IP_MULTICAST_IF: 1009 case IP_MULTICAST_TTL: 1010 case IP_MULTICAST_LOOP: 1011 case IP_ADD_MEMBERSHIP: 1012 case IP_DROP_MEMBERSHIP: 1013 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1014 break; 1015 1016 case IP_PORTRANGE: 1017 if (m == 0 || m->m_len != sizeof(int)) 1018 error = EINVAL; 1019 else { 1020 optval = *mtod(m, int *); 1021 1022 switch (optval) { 1023 1024 case IP_PORTRANGE_DEFAULT: 1025 case IP_PORTRANGE_HIGH: 1026 inp->inp_flags &= ~(INP_LOWPORT); 1027 break; 1028 1029 case IP_PORTRANGE_LOW: 1030 inp->inp_flags |= INP_LOWPORT; 1031 break; 1032 1033 default: 1034 error = EINVAL; 1035 break; 1036 } 1037 } 1038 break; 1039 1040 #ifdef IPSEC 1041 case IP_IPSEC_POLICY: 1042 { 1043 caddr_t req = NULL; 1044 size_t len = 0; 1045 int priv = 0; 1046 1047 #ifdef __NetBSD__ 1048 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1049 priv = 0; 1050 else 1051 priv = 1; 1052 #else 1053 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1054 #endif 1055 if (m) { 1056 req = mtod(m, caddr_t); 1057 len = m->m_len; 1058 } 1059 error = ipsec4_set_policy(inp, optname, req, len, priv); 1060 break; 1061 } 1062 #endif /*IPSEC*/ 1063 1064 default: 1065 error = ENOPROTOOPT; 1066 break; 1067 } 1068 if (m) 1069 (void)m_free(m); 1070 break; 1071 1072 case PRCO_GETOPT: 1073 switch (optname) { 1074 case IP_OPTIONS: 1075 case IP_RETOPTS: 1076 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1077 if (inp->inp_options) { 1078 m->m_len = inp->inp_options->m_len; 1079 bcopy(mtod(inp->inp_options, caddr_t), 1080 mtod(m, caddr_t), (unsigned)m->m_len); 1081 } else 1082 m->m_len = 0; 1083 break; 1084 1085 case IP_TOS: 1086 case IP_TTL: 1087 case IP_RECVOPTS: 1088 case IP_RECVRETOPTS: 1089 case IP_RECVDSTADDR: 1090 case IP_RECVIF: 1091 case IP_ERRORMTU: 1092 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1093 m->m_len = sizeof(int); 1094 switch (optname) { 1095 1096 case IP_TOS: 1097 optval = inp->inp_ip.ip_tos; 1098 break; 1099 1100 case IP_TTL: 1101 optval = inp->inp_ip.ip_ttl; 1102 break; 1103 1104 case IP_ERRORMTU: 1105 optval = inp->inp_errormtu; 1106 break; 1107 1108 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1109 1110 case IP_RECVOPTS: 1111 optval = OPTBIT(INP_RECVOPTS); 1112 break; 1113 1114 case IP_RECVRETOPTS: 1115 optval = OPTBIT(INP_RECVRETOPTS); 1116 break; 1117 1118 case IP_RECVDSTADDR: 1119 optval = OPTBIT(INP_RECVDSTADDR); 1120 break; 1121 1122 case IP_RECVIF: 1123 optval = OPTBIT(INP_RECVIF); 1124 break; 1125 } 1126 *mtod(m, int *) = optval; 1127 break; 1128 1129 #ifdef IPSEC 1130 case IP_IPSEC_POLICY: 1131 { 1132 caddr_t req = NULL; 1133 size_t len = 0; 1134 1135 if (m) { 1136 req = mtod(m, caddr_t); 1137 len = m->m_len; 1138 } 1139 error = ipsec4_get_policy(inp, req, len, mp); 1140 break; 1141 } 1142 #endif /*IPSEC*/ 1143 1144 case IP_MULTICAST_IF: 1145 case IP_MULTICAST_TTL: 1146 case IP_MULTICAST_LOOP: 1147 case IP_ADD_MEMBERSHIP: 1148 case IP_DROP_MEMBERSHIP: 1149 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1150 break; 1151 1152 case IP_PORTRANGE: 1153 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1154 m->m_len = sizeof(int); 1155 1156 if (inp->inp_flags & INP_LOWPORT) 1157 optval = IP_PORTRANGE_LOW; 1158 else 1159 optval = IP_PORTRANGE_DEFAULT; 1160 1161 *mtod(m, int *) = optval; 1162 break; 1163 1164 default: 1165 error = ENOPROTOOPT; 1166 break; 1167 } 1168 break; 1169 } 1170 return (error); 1171 } 1172 1173 /* 1174 * Set up IP options in pcb for insertion in output packets. 1175 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1176 * with destination address if source routed. 1177 */ 1178 int 1179 #ifdef notyet 1180 ip_pcbopts(optname, pcbopt, m) 1181 int optname; 1182 #else 1183 ip_pcbopts(pcbopt, m) 1184 #endif 1185 struct mbuf **pcbopt; 1186 struct mbuf *m; 1187 { 1188 int cnt, optlen; 1189 u_char *cp; 1190 u_char opt; 1191 1192 /* turn off any old options */ 1193 if (*pcbopt) 1194 (void)m_free(*pcbopt); 1195 *pcbopt = 0; 1196 if (m == (struct mbuf *)0 || m->m_len == 0) { 1197 /* 1198 * Only turning off any previous options. 1199 */ 1200 if (m) 1201 (void)m_free(m); 1202 return (0); 1203 } 1204 1205 #ifndef __vax__ 1206 if (m->m_len % sizeof(int32_t)) 1207 goto bad; 1208 #endif 1209 /* 1210 * IP first-hop destination address will be stored before 1211 * actual options; move other options back 1212 * and clear it when none present. 1213 */ 1214 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1215 goto bad; 1216 cnt = m->m_len; 1217 m->m_len += sizeof(struct in_addr); 1218 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1219 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1220 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1221 1222 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1223 opt = cp[IPOPT_OPTVAL]; 1224 if (opt == IPOPT_EOL) 1225 break; 1226 if (opt == IPOPT_NOP) 1227 optlen = 1; 1228 else { 1229 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1230 goto bad; 1231 optlen = cp[IPOPT_OLEN]; 1232 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1233 goto bad; 1234 } 1235 switch (opt) { 1236 1237 default: 1238 break; 1239 1240 case IPOPT_LSRR: 1241 case IPOPT_SSRR: 1242 /* 1243 * user process specifies route as: 1244 * ->A->B->C->D 1245 * D must be our final destination (but we can't 1246 * check that since we may not have connected yet). 1247 * A is first hop destination, which doesn't appear in 1248 * actual IP option, but is stored before the options. 1249 */ 1250 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1251 goto bad; 1252 m->m_len -= sizeof(struct in_addr); 1253 cnt -= sizeof(struct in_addr); 1254 optlen -= sizeof(struct in_addr); 1255 cp[IPOPT_OLEN] = optlen; 1256 /* 1257 * Move first hop before start of options. 1258 */ 1259 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1260 sizeof(struct in_addr)); 1261 /* 1262 * Then copy rest of options back 1263 * to close up the deleted entry. 1264 */ 1265 memmove(&cp[IPOPT_OFFSET+1], 1266 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1267 (unsigned)cnt + sizeof(struct in_addr)); 1268 break; 1269 } 1270 } 1271 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1272 goto bad; 1273 *pcbopt = m; 1274 return (0); 1275 1276 bad: 1277 (void)m_free(m); 1278 return (EINVAL); 1279 } 1280 1281 /* 1282 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1283 */ 1284 static struct ifnet * 1285 ip_multicast_if(a, ifindexp) 1286 struct in_addr *a; 1287 int *ifindexp; 1288 { 1289 int ifindex; 1290 struct ifnet *ifp; 1291 1292 if (ifindexp) 1293 *ifindexp = 0; 1294 if (ntohl(a->s_addr) >> 24 == 0) { 1295 ifindex = ntohl(a->s_addr) & 0xffffff; 1296 if (ifindex < 0 || if_index < ifindex) 1297 return NULL; 1298 ifp = ifindex2ifnet[ifindex]; 1299 if (ifindexp) 1300 *ifindexp = ifindex; 1301 } else { 1302 INADDR_TO_IFP(*a, ifp); 1303 } 1304 return ifp; 1305 } 1306 1307 /* 1308 * Set the IP multicast options in response to user setsockopt(). 1309 */ 1310 int 1311 ip_setmoptions(optname, imop, m) 1312 int optname; 1313 struct ip_moptions **imop; 1314 struct mbuf *m; 1315 { 1316 int error = 0; 1317 u_char loop; 1318 int i; 1319 struct in_addr addr; 1320 struct ip_mreq *mreq; 1321 struct ifnet *ifp; 1322 struct ip_moptions *imo = *imop; 1323 struct route ro; 1324 struct sockaddr_in *dst; 1325 int ifindex; 1326 1327 if (imo == NULL) { 1328 /* 1329 * No multicast option buffer attached to the pcb; 1330 * allocate one and initialize to default values. 1331 */ 1332 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1333 M_WAITOK); 1334 1335 if (imo == NULL) 1336 return (ENOBUFS); 1337 *imop = imo; 1338 imo->imo_multicast_ifp = NULL; 1339 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1340 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1341 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1342 imo->imo_num_memberships = 0; 1343 } 1344 1345 switch (optname) { 1346 1347 case IP_MULTICAST_IF: 1348 /* 1349 * Select the interface for outgoing multicast packets. 1350 */ 1351 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1352 error = EINVAL; 1353 break; 1354 } 1355 addr = *(mtod(m, struct in_addr *)); 1356 /* 1357 * INADDR_ANY is used to remove a previous selection. 1358 * When no interface is selected, a default one is 1359 * chosen every time a multicast packet is sent. 1360 */ 1361 if (in_nullhost(addr)) { 1362 imo->imo_multicast_ifp = NULL; 1363 break; 1364 } 1365 /* 1366 * The selected interface is identified by its local 1367 * IP address. Find the interface and confirm that 1368 * it supports multicasting. 1369 */ 1370 ifp = ip_multicast_if(&addr, &ifindex); 1371 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1372 error = EADDRNOTAVAIL; 1373 break; 1374 } 1375 imo->imo_multicast_ifp = ifp; 1376 if (ifindex) 1377 imo->imo_multicast_addr = addr; 1378 else 1379 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1380 break; 1381 1382 case IP_MULTICAST_TTL: 1383 /* 1384 * Set the IP time-to-live for outgoing multicast packets. 1385 */ 1386 if (m == NULL || m->m_len != 1) { 1387 error = EINVAL; 1388 break; 1389 } 1390 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1391 break; 1392 1393 case IP_MULTICAST_LOOP: 1394 /* 1395 * Set the loopback flag for outgoing multicast packets. 1396 * Must be zero or one. 1397 */ 1398 if (m == NULL || m->m_len != 1 || 1399 (loop = *(mtod(m, u_char *))) > 1) { 1400 error = EINVAL; 1401 break; 1402 } 1403 imo->imo_multicast_loop = loop; 1404 break; 1405 1406 case IP_ADD_MEMBERSHIP: 1407 /* 1408 * Add a multicast group membership. 1409 * Group must be a valid IP multicast address. 1410 */ 1411 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1412 error = EINVAL; 1413 break; 1414 } 1415 mreq = mtod(m, struct ip_mreq *); 1416 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1417 error = EINVAL; 1418 break; 1419 } 1420 /* 1421 * If no interface address was provided, use the interface of 1422 * the route to the given multicast address. 1423 */ 1424 if (in_nullhost(mreq->imr_interface)) { 1425 bzero((caddr_t)&ro, sizeof(ro)); 1426 ro.ro_rt = NULL; 1427 dst = satosin(&ro.ro_dst); 1428 dst->sin_len = sizeof(*dst); 1429 dst->sin_family = AF_INET; 1430 dst->sin_addr = mreq->imr_multiaddr; 1431 rtalloc(&ro); 1432 if (ro.ro_rt == NULL) { 1433 error = EADDRNOTAVAIL; 1434 break; 1435 } 1436 ifp = ro.ro_rt->rt_ifp; 1437 rtfree(ro.ro_rt); 1438 } else { 1439 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1440 } 1441 /* 1442 * See if we found an interface, and confirm that it 1443 * supports multicast. 1444 */ 1445 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1446 error = EADDRNOTAVAIL; 1447 break; 1448 } 1449 /* 1450 * See if the membership already exists or if all the 1451 * membership slots are full. 1452 */ 1453 for (i = 0; i < imo->imo_num_memberships; ++i) { 1454 if (imo->imo_membership[i]->inm_ifp == ifp && 1455 in_hosteq(imo->imo_membership[i]->inm_addr, 1456 mreq->imr_multiaddr)) 1457 break; 1458 } 1459 if (i < imo->imo_num_memberships) { 1460 error = EADDRINUSE; 1461 break; 1462 } 1463 if (i == IP_MAX_MEMBERSHIPS) { 1464 error = ETOOMANYREFS; 1465 break; 1466 } 1467 /* 1468 * Everything looks good; add a new record to the multicast 1469 * address list for the given interface. 1470 */ 1471 if ((imo->imo_membership[i] = 1472 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1473 error = ENOBUFS; 1474 break; 1475 } 1476 ++imo->imo_num_memberships; 1477 break; 1478 1479 case IP_DROP_MEMBERSHIP: 1480 /* 1481 * Drop a multicast group membership. 1482 * Group must be a valid IP multicast address. 1483 */ 1484 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1485 error = EINVAL; 1486 break; 1487 } 1488 mreq = mtod(m, struct ip_mreq *); 1489 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1490 error = EINVAL; 1491 break; 1492 } 1493 /* 1494 * If an interface address was specified, get a pointer 1495 * to its ifnet structure. 1496 */ 1497 if (in_nullhost(mreq->imr_interface)) 1498 ifp = NULL; 1499 else { 1500 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1501 if (ifp == NULL) { 1502 error = EADDRNOTAVAIL; 1503 break; 1504 } 1505 } 1506 /* 1507 * Find the membership in the membership array. 1508 */ 1509 for (i = 0; i < imo->imo_num_memberships; ++i) { 1510 if ((ifp == NULL || 1511 imo->imo_membership[i]->inm_ifp == ifp) && 1512 in_hosteq(imo->imo_membership[i]->inm_addr, 1513 mreq->imr_multiaddr)) 1514 break; 1515 } 1516 if (i == imo->imo_num_memberships) { 1517 error = EADDRNOTAVAIL; 1518 break; 1519 } 1520 /* 1521 * Give up the multicast address record to which the 1522 * membership points. 1523 */ 1524 in_delmulti(imo->imo_membership[i]); 1525 /* 1526 * Remove the gap in the membership array. 1527 */ 1528 for (++i; i < imo->imo_num_memberships; ++i) 1529 imo->imo_membership[i-1] = imo->imo_membership[i]; 1530 --imo->imo_num_memberships; 1531 break; 1532 1533 default: 1534 error = EOPNOTSUPP; 1535 break; 1536 } 1537 1538 /* 1539 * If all options have default values, no need to keep the mbuf. 1540 */ 1541 if (imo->imo_multicast_ifp == NULL && 1542 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1543 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1544 imo->imo_num_memberships == 0) { 1545 free(*imop, M_IPMOPTS); 1546 *imop = NULL; 1547 } 1548 1549 return (error); 1550 } 1551 1552 /* 1553 * Return the IP multicast options in response to user getsockopt(). 1554 */ 1555 int 1556 ip_getmoptions(optname, imo, mp) 1557 int optname; 1558 struct ip_moptions *imo; 1559 struct mbuf **mp; 1560 { 1561 u_char *ttl; 1562 u_char *loop; 1563 struct in_addr *addr; 1564 struct in_ifaddr *ia; 1565 1566 *mp = m_get(M_WAIT, MT_SOOPTS); 1567 1568 switch (optname) { 1569 1570 case IP_MULTICAST_IF: 1571 addr = mtod(*mp, struct in_addr *); 1572 (*mp)->m_len = sizeof(struct in_addr); 1573 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1574 *addr = zeroin_addr; 1575 else if (imo->imo_multicast_addr.s_addr) { 1576 /* return the value user has set */ 1577 *addr = imo->imo_multicast_addr; 1578 } else { 1579 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1580 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1581 } 1582 return (0); 1583 1584 case IP_MULTICAST_TTL: 1585 ttl = mtod(*mp, u_char *); 1586 (*mp)->m_len = 1; 1587 *ttl = imo ? imo->imo_multicast_ttl 1588 : IP_DEFAULT_MULTICAST_TTL; 1589 return (0); 1590 1591 case IP_MULTICAST_LOOP: 1592 loop = mtod(*mp, u_char *); 1593 (*mp)->m_len = 1; 1594 *loop = imo ? imo->imo_multicast_loop 1595 : IP_DEFAULT_MULTICAST_LOOP; 1596 return (0); 1597 1598 default: 1599 return (EOPNOTSUPP); 1600 } 1601 } 1602 1603 /* 1604 * Discard the IP multicast options. 1605 */ 1606 void 1607 ip_freemoptions(imo) 1608 struct ip_moptions *imo; 1609 { 1610 int i; 1611 1612 if (imo != NULL) { 1613 for (i = 0; i < imo->imo_num_memberships; ++i) 1614 in_delmulti(imo->imo_membership[i]); 1615 free(imo, M_IPMOPTS); 1616 } 1617 } 1618 1619 /* 1620 * Routine called from ip_output() to loop back a copy of an IP multicast 1621 * packet to the input queue of a specified interface. Note that this 1622 * calls the output routine of the loopback "driver", but with an interface 1623 * pointer that might NOT be &loif -- easier than replicating that code here. 1624 */ 1625 static void 1626 ip_mloopback(ifp, m, dst) 1627 struct ifnet *ifp; 1628 struct mbuf *m; 1629 struct sockaddr_in *dst; 1630 { 1631 struct ip *ip; 1632 struct mbuf *copym; 1633 1634 copym = m_copy(m, 0, M_COPYALL); 1635 if (copym != NULL 1636 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1637 copym = m_pullup(copym, sizeof(struct ip)); 1638 if (copym != NULL) { 1639 /* 1640 * We don't bother to fragment if the IP length is greater 1641 * than the interface's MTU. Can this possibly matter? 1642 */ 1643 ip = mtod(copym, struct ip *); 1644 HTONS(ip->ip_len); 1645 HTONS(ip->ip_off); 1646 1647 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1648 in_delayed_cksum(m); 1649 copym->m_pkthdr.csum_flags &= 1650 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1651 } 1652 1653 ip->ip_sum = 0; 1654 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1655 (void) looutput(ifp, copym, sintosa(dst), NULL); 1656 } 1657 } 1658