1 /* $NetBSD: ip_output.c,v 1.103 2003/02/26 06:31:15 matt 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 1.103 2003/02/26 06:31:15 matt 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 u_long 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 len = 0; 190 va_start(ap, m0); 191 opt = va_arg(ap, struct mbuf *); 192 ro = va_arg(ap, struct route *); 193 flags = va_arg(ap, int); 194 imo = va_arg(ap, struct ip_moptions *); 195 if (flags & IP_RETURNMTU) 196 mtu_p = va_arg(ap, int *); 197 else 198 mtu_p = NULL; 199 va_end(ap); 200 201 MCLAIM(m, &ip_tx_mowner); 202 #ifdef IPSEC 203 so = ipsec_getsocket(m); 204 (void)ipsec_setsocket(m, NULL); 205 #endif /*IPSEC*/ 206 207 #ifdef DIAGNOSTIC 208 if ((m->m_flags & M_PKTHDR) == 0) 209 panic("ip_output no HDR"); 210 #endif 211 if (opt) { 212 m = ip_insertoptions(m, opt, &len); 213 if (len >= sizeof(struct ip)) 214 hlen = len; 215 } 216 ip = mtod(m, struct ip *); 217 /* 218 * Fill in IP header. 219 */ 220 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 221 ip->ip_v = IPVERSION; 222 ip->ip_off = htons(0); 223 ip->ip_id = htons(ip_id++); 224 ip->ip_hl = hlen >> 2; 225 ipstat.ips_localout++; 226 } else { 227 hlen = ip->ip_hl << 2; 228 } 229 /* 230 * Route packet. 231 */ 232 if (ro == 0) { 233 ro = &iproute; 234 bzero((caddr_t)ro, sizeof (*ro)); 235 } 236 dst = satosin(&ro->ro_dst); 237 /* 238 * If there is a cached route, 239 * check that it is to the same destination 240 * and is still up. If not, free it and try again. 241 * The address family should also be checked in case of sharing the 242 * cache with IPv6. 243 */ 244 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 245 dst->sin_family != AF_INET || 246 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 247 RTFREE(ro->ro_rt); 248 ro->ro_rt = (struct rtentry *)0; 249 } 250 if (ro->ro_rt == 0) { 251 bzero(dst, sizeof(*dst)); 252 dst->sin_family = AF_INET; 253 dst->sin_len = sizeof(*dst); 254 dst->sin_addr = ip->ip_dst; 255 } 256 /* 257 * If routing to interface only, 258 * short circuit routing lookup. 259 */ 260 if (flags & IP_ROUTETOIF) { 261 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 262 ipstat.ips_noroute++; 263 error = ENETUNREACH; 264 goto bad; 265 } 266 ifp = ia->ia_ifp; 267 mtu = ifp->if_mtu; 268 ip->ip_ttl = 1; 269 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 270 ip->ip_dst.s_addr == INADDR_BROADCAST) && 271 imo != NULL && imo->imo_multicast_ifp != NULL) { 272 ifp = imo->imo_multicast_ifp; 273 mtu = ifp->if_mtu; 274 IFP_TO_IA(ifp, ia); 275 } else { 276 if (ro->ro_rt == 0) 277 rtalloc(ro); 278 if (ro->ro_rt == 0) { 279 ipstat.ips_noroute++; 280 error = EHOSTUNREACH; 281 goto bad; 282 } 283 ia = ifatoia(ro->ro_rt->rt_ifa); 284 ifp = ro->ro_rt->rt_ifp; 285 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 286 mtu = ifp->if_mtu; 287 ro->ro_rt->rt_use++; 288 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 289 dst = satosin(ro->ro_rt->rt_gateway); 290 } 291 if (IN_MULTICAST(ip->ip_dst.s_addr) || 292 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 293 struct in_multi *inm; 294 295 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 296 M_BCAST : M_MCAST; 297 /* 298 * IP destination address is multicast. Make sure "dst" 299 * still points to the address in "ro". (It may have been 300 * changed to point to a gateway address, above.) 301 */ 302 dst = satosin(&ro->ro_dst); 303 /* 304 * See if the caller provided any multicast options 305 */ 306 if (imo != NULL) 307 ip->ip_ttl = imo->imo_multicast_ttl; 308 else 309 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 310 311 /* 312 * if we don't know the outgoing ifp yet, we can't generate 313 * output 314 */ 315 if (!ifp) { 316 ipstat.ips_noroute++; 317 error = ENETUNREACH; 318 goto bad; 319 } 320 321 /* 322 * If the packet is multicast or broadcast, confirm that 323 * the outgoing interface can transmit it. 324 */ 325 if (((m->m_flags & M_MCAST) && 326 (ifp->if_flags & IFF_MULTICAST) == 0) || 327 ((m->m_flags & M_BCAST) && 328 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 329 ipstat.ips_noroute++; 330 error = ENETUNREACH; 331 goto bad; 332 } 333 /* 334 * If source address not specified yet, use an address 335 * of outgoing interface. 336 */ 337 if (in_nullhost(ip->ip_src)) { 338 struct in_ifaddr *ia; 339 340 IFP_TO_IA(ifp, ia); 341 if (!ia) { 342 error = EADDRNOTAVAIL; 343 goto bad; 344 } 345 ip->ip_src = ia->ia_addr.sin_addr; 346 } 347 348 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 349 if (inm != NULL && 350 (imo == NULL || imo->imo_multicast_loop)) { 351 /* 352 * If we belong to the destination multicast group 353 * on the outgoing interface, and the caller did not 354 * forbid loopback, loop back a copy. 355 */ 356 ip_mloopback(ifp, m, dst); 357 } 358 #ifdef MROUTING 359 else { 360 /* 361 * If we are acting as a multicast router, perform 362 * multicast forwarding as if the packet had just 363 * arrived on the interface to which we are about 364 * to send. The multicast forwarding function 365 * recursively calls this function, using the 366 * IP_FORWARDING flag to prevent infinite recursion. 367 * 368 * Multicasts that are looped back by ip_mloopback(), 369 * above, will be forwarded by the ip_input() routine, 370 * if necessary. 371 */ 372 extern struct socket *ip_mrouter; 373 374 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 375 if (ip_mforward(m, ifp) != 0) { 376 m_freem(m); 377 goto done; 378 } 379 } 380 } 381 #endif 382 /* 383 * Multicasts with a time-to-live of zero may be looped- 384 * back, above, but must not be transmitted on a network. 385 * Also, multicasts addressed to the loopback interface 386 * are not sent -- the above call to ip_mloopback() will 387 * loop back a copy if this host actually belongs to the 388 * destination group on the loopback interface. 389 */ 390 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 391 m_freem(m); 392 goto done; 393 } 394 395 goto sendit; 396 } 397 #ifndef notdef 398 /* 399 * If source address not specified yet, use address 400 * of outgoing interface. 401 */ 402 if (in_nullhost(ip->ip_src)) 403 ip->ip_src = ia->ia_addr.sin_addr; 404 #endif 405 406 /* 407 * packets with Class-D address as source are not valid per 408 * RFC 1112 409 */ 410 if (IN_MULTICAST(ip->ip_src.s_addr)) { 411 ipstat.ips_odropped++; 412 error = EADDRNOTAVAIL; 413 goto bad; 414 } 415 416 /* 417 * Look for broadcast address and 418 * and verify user is allowed to send 419 * such a packet. 420 */ 421 if (in_broadcast(dst->sin_addr, ifp)) { 422 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 423 error = EADDRNOTAVAIL; 424 goto bad; 425 } 426 if ((flags & IP_ALLOWBROADCAST) == 0) { 427 error = EACCES; 428 goto bad; 429 } 430 /* don't allow broadcast messages to be fragmented */ 431 if (ntohs(ip->ip_len) > ifp->if_mtu) { 432 error = EMSGSIZE; 433 goto bad; 434 } 435 m->m_flags |= M_BCAST; 436 } else 437 m->m_flags &= ~M_BCAST; 438 439 sendit: 440 /* 441 * If we're doing Path MTU Discovery, we need to set DF unless 442 * the route's MTU is locked. 443 */ 444 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 445 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 446 ip->ip_off |= htons(IP_DF); 447 448 /* Remember the current ip_len */ 449 ip_len = ntohs(ip->ip_len); 450 451 #ifdef IPSEC 452 /* get SP for this packet */ 453 if (so == NULL) 454 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); 455 else 456 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 457 458 if (sp == NULL) { 459 ipsecstat.out_inval++; 460 goto bad; 461 } 462 463 error = 0; 464 465 /* check policy */ 466 switch (sp->policy) { 467 case IPSEC_POLICY_DISCARD: 468 /* 469 * This packet is just discarded. 470 */ 471 ipsecstat.out_polvio++; 472 goto bad; 473 474 case IPSEC_POLICY_BYPASS: 475 case IPSEC_POLICY_NONE: 476 /* no need to do IPsec. */ 477 goto skip_ipsec; 478 479 case IPSEC_POLICY_IPSEC: 480 if (sp->req == NULL) { 481 /* XXX should be panic ? */ 482 printf("ip_output: No IPsec request specified.\n"); 483 error = EINVAL; 484 goto bad; 485 } 486 break; 487 488 case IPSEC_POLICY_ENTRUST: 489 default: 490 printf("ip_output: Invalid policy found. %d\n", sp->policy); 491 } 492 493 /* 494 * ipsec4_output() expects ip_len and ip_off in network 495 * order. They have been set to network order above. 496 */ 497 498 { 499 struct ipsec_output_state state; 500 bzero(&state, sizeof(state)); 501 state.m = m; 502 if (flags & IP_ROUTETOIF) { 503 state.ro = &iproute; 504 bzero(&iproute, sizeof(iproute)); 505 } else 506 state.ro = ro; 507 state.dst = (struct sockaddr *)dst; 508 509 /* 510 * We can't defer the checksum of payload data if 511 * we're about to encrypt/authenticate it. 512 * 513 * XXX When we support crypto offloading functions of 514 * XXX network interfaces, we need to reconsider this, 515 * XXX since it's likely that they'll support checksumming, 516 * XXX as well. 517 */ 518 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 519 in_delayed_cksum(m); 520 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 521 } 522 523 error = ipsec4_output(&state, sp, flags); 524 525 m = state.m; 526 if (flags & IP_ROUTETOIF) { 527 /* 528 * if we have tunnel mode SA, we may need to ignore 529 * IP_ROUTETOIF. 530 */ 531 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 532 flags &= ~IP_ROUTETOIF; 533 ro = state.ro; 534 } 535 } else 536 ro = state.ro; 537 dst = (struct sockaddr_in *)state.dst; 538 if (error) { 539 /* mbuf is already reclaimed in ipsec4_output. */ 540 m0 = NULL; 541 switch (error) { 542 case EHOSTUNREACH: 543 case ENETUNREACH: 544 case EMSGSIZE: 545 case ENOBUFS: 546 case ENOMEM: 547 break; 548 default: 549 printf("ip4_output (ipsec): error code %d\n", error); 550 /*fall through*/ 551 case ENOENT: 552 /* don't show these error codes to the user */ 553 error = 0; 554 break; 555 } 556 goto bad; 557 } 558 559 /* be sure to update variables that are affected by ipsec4_output() */ 560 ip = mtod(m, struct ip *); 561 #ifdef _IP_VHL 562 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 563 #else 564 hlen = ip->ip_hl << 2; 565 #endif 566 ip_len = ntohs(ip->ip_len); 567 568 if (ro->ro_rt == NULL) { 569 if ((flags & IP_ROUTETOIF) == 0) { 570 printf("ip_output: " 571 "can't update route after IPsec processing\n"); 572 error = EHOSTUNREACH; /*XXX*/ 573 goto bad; 574 } 575 } else { 576 /* nobody uses ia beyond here */ 577 if (state.encap) 578 ifp = ro->ro_rt->rt_ifp; 579 } 580 } 581 582 skip_ipsec: 583 #endif /*IPSEC*/ 584 585 #ifdef PFIL_HOOKS 586 /* 587 * Run through list of hooks for output packets. 588 */ 589 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, 590 PFIL_OUT)) != 0) 591 goto done; 592 if (m == NULL) 593 goto done; 594 595 ip = mtod(m, struct ip *); 596 #endif /* PFIL_HOOKS */ 597 598 /* 599 * If small enough for mtu of path, can just send directly. 600 */ 601 if (ip_len <= mtu) { 602 #if IFA_STATS 603 /* 604 * search for the source address structure to 605 * maintain output statistics. 606 */ 607 INADDR_TO_IA(ip->ip_src, ia); 608 if (ia) 609 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 610 #endif 611 /* 612 * Always initialize the sum to 0! Some HW assisted 613 * checksumming requires this. 614 */ 615 ip->ip_sum = 0; 616 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 617 618 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 619 620 /* 621 * Perform any checksums that the hardware can't do 622 * for us. 623 * 624 * XXX Does any hardware require the {th,uh}_sum 625 * XXX fields to be 0? 626 */ 627 if (sw_csum & M_CSUM_IPv4) 628 ip->ip_sum = in_cksum(m, hlen); 629 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 630 in_delayed_cksum(m); 631 sw_csum &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 632 } 633 m->m_pkthdr.csum_flags &= ifp->if_csum_flags_tx; 634 635 #ifdef IPSEC 636 /* clean ipsec history once it goes out of the node */ 637 ipsec_delaux(m); 638 #endif 639 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 640 goto done; 641 } 642 643 /* 644 * We can't use HW checksumming if we're about to 645 * to fragment the packet. 646 * 647 * XXX Some hardware can do this. 648 */ 649 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 650 in_delayed_cksum(m); 651 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 652 } 653 654 /* 655 * Too large for interface; fragment if possible. 656 * Must be able to put at least 8 bytes per fragment. 657 */ 658 if (ntohs(ip->ip_off) & IP_DF) { 659 if (flags & IP_RETURNMTU) 660 *mtu_p = mtu; 661 error = EMSGSIZE; 662 ipstat.ips_cantfrag++; 663 goto bad; 664 } 665 len = (mtu - hlen) &~ 7; 666 if (len < 8) { 667 error = EMSGSIZE; 668 goto bad; 669 } 670 671 { 672 int mhlen, firstlen = len; 673 struct mbuf **mnext = &m->m_nextpkt; 674 int fragments = 0; 675 int s; 676 677 /* 678 * Loop through length of segment after first fragment, 679 * make new header and copy data of each part and link onto chain. 680 */ 681 m0 = m; 682 mhlen = sizeof (struct ip); 683 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 684 MGETHDR(m, M_DONTWAIT, MT_HEADER); 685 if (m == 0) { 686 error = ENOBUFS; 687 ipstat.ips_odropped++; 688 goto sendorfree; 689 } 690 MCLAIM(m, m0->m_owner); 691 *mnext = m; 692 mnext = &m->m_nextpkt; 693 m->m_data += max_linkhdr; 694 mhip = mtod(m, struct ip *); 695 *mhip = *ip; 696 /* we must inherit MCAST and BCAST flags */ 697 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 698 if (hlen > sizeof (struct ip)) { 699 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 700 mhip->ip_hl = mhlen >> 2; 701 } 702 m->m_len = mhlen; 703 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 704 if (ip->ip_off & IP_MF) 705 mhip->ip_off |= IP_MF; 706 if (off + len >= ntohs(ip->ip_len)) 707 len = ntohs(ip->ip_len) - off; 708 else 709 mhip->ip_off |= IP_MF; 710 HTONS(mhip->ip_off); 711 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 712 m->m_next = m_copy(m0, off, len); 713 if (m->m_next == 0) { 714 error = ENOBUFS; /* ??? */ 715 ipstat.ips_odropped++; 716 goto sendorfree; 717 } 718 m->m_pkthdr.len = mhlen + len; 719 m->m_pkthdr.rcvif = (struct ifnet *)0; 720 mhip->ip_sum = 0; 721 mhip->ip_sum = in_cksum(m, mhlen); 722 ipstat.ips_ofragments++; 723 fragments++; 724 } 725 /* 726 * Update first fragment by trimming what's been copied out 727 * and updating header, then send each fragment (in order). 728 */ 729 m = m0; 730 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 731 m->m_pkthdr.len = hlen + firstlen; 732 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 733 ip->ip_off |= htons(IP_MF); 734 ip->ip_sum = 0; 735 ip->ip_sum = in_cksum(m, hlen); 736 sendorfree: 737 /* 738 * If there is no room for all the fragments, don't queue 739 * any of them. 740 */ 741 s = splnet(); 742 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 743 error = ENOBUFS; 744 splx(s); 745 for (m = m0; m; m = m0) { 746 m0 = m->m_nextpkt; 747 m->m_nextpkt = 0; 748 if (error == 0) { 749 #if IFA_STATS 750 /* 751 * search for the source address structure to 752 * maintain output statistics. 753 */ 754 INADDR_TO_IA(ip->ip_src, ia); 755 if (ia) { 756 ia->ia_ifa.ifa_data.ifad_outbytes += 757 ntohs(ip->ip_len); 758 } 759 #endif 760 #ifdef IPSEC 761 /* clean ipsec history once it goes out of the node */ 762 ipsec_delaux(m); 763 #endif 764 error = (*ifp->if_output)(ifp, m, sintosa(dst), 765 ro->ro_rt); 766 } else 767 m_freem(m); 768 } 769 770 if (error == 0) 771 ipstat.ips_fragmented++; 772 } 773 done: 774 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 775 RTFREE(ro->ro_rt); 776 ro->ro_rt = 0; 777 } 778 779 #ifdef IPSEC 780 if (sp != NULL) { 781 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 782 printf("DP ip_output call free SP:%p\n", sp)); 783 key_freesp(sp); 784 } 785 #endif /* IPSEC */ 786 787 return (error); 788 bad: 789 m_freem(m); 790 goto done; 791 } 792 793 /* 794 * Process a delayed payload checksum calculation. 795 */ 796 void 797 in_delayed_cksum(struct mbuf *m) 798 { 799 struct ip *ip; 800 u_int16_t csum, offset; 801 802 ip = mtod(m, struct ip *); 803 offset = ip->ip_hl << 2; 804 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 805 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 806 csum = 0xffff; 807 808 offset += m->m_pkthdr.csum_data; /* checksum offset */ 809 810 if ((offset + sizeof(u_int16_t)) > m->m_len) { 811 /* This happen when ip options were inserted 812 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 813 m->m_len, offset, ip->ip_p); 814 */ 815 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 816 } else 817 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 818 } 819 820 /* 821 * Determine the maximum length of the options to be inserted; 822 * we would far rather allocate too much space rather than too little. 823 */ 824 825 u_int 826 ip_optlen(inp) 827 struct inpcb *inp; 828 { 829 struct mbuf *m = inp->inp_options; 830 831 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 832 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 833 else 834 return 0; 835 } 836 837 838 /* 839 * Insert IP options into preformed packet. 840 * Adjust IP destination as required for IP source routing, 841 * as indicated by a non-zero in_addr at the start of the options. 842 */ 843 static struct mbuf * 844 ip_insertoptions(m, opt, phlen) 845 struct mbuf *m; 846 struct mbuf *opt; 847 int *phlen; 848 { 849 struct ipoption *p = mtod(opt, struct ipoption *); 850 struct mbuf *n; 851 struct ip *ip = mtod(m, struct ip *); 852 unsigned optlen; 853 854 optlen = opt->m_len - sizeof(p->ipopt_dst); 855 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 856 return (m); /* XXX should fail */ 857 if (!in_nullhost(p->ipopt_dst)) 858 ip->ip_dst = p->ipopt_dst; 859 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 860 MGETHDR(n, M_DONTWAIT, MT_HEADER); 861 if (n == 0) 862 return (m); 863 MCLAIM(n, m->m_owner); 864 M_COPY_PKTHDR(n, m); 865 m->m_flags &= ~M_PKTHDR; 866 m->m_len -= sizeof(struct ip); 867 m->m_data += sizeof(struct ip); 868 n->m_next = m; 869 m = n; 870 m->m_len = optlen + sizeof(struct ip); 871 m->m_data += max_linkhdr; 872 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 873 } else { 874 m->m_data -= optlen; 875 m->m_len += optlen; 876 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 877 } 878 m->m_pkthdr.len += optlen; 879 ip = mtod(m, struct ip *); 880 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 881 *phlen = sizeof(struct ip) + optlen; 882 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 883 return (m); 884 } 885 886 /* 887 * Copy options from ip to jp, 888 * omitting those not copied during fragmentation. 889 */ 890 int 891 ip_optcopy(ip, jp) 892 struct ip *ip, *jp; 893 { 894 u_char *cp, *dp; 895 int opt, optlen, cnt; 896 897 cp = (u_char *)(ip + 1); 898 dp = (u_char *)(jp + 1); 899 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 900 for (; cnt > 0; cnt -= optlen, cp += optlen) { 901 opt = cp[0]; 902 if (opt == IPOPT_EOL) 903 break; 904 if (opt == IPOPT_NOP) { 905 /* Preserve for IP mcast tunnel's LSRR alignment. */ 906 *dp++ = IPOPT_NOP; 907 optlen = 1; 908 continue; 909 } 910 #ifdef DIAGNOSTIC 911 if (cnt < IPOPT_OLEN + sizeof(*cp)) 912 panic("malformed IPv4 option passed to ip_optcopy"); 913 #endif 914 optlen = cp[IPOPT_OLEN]; 915 #ifdef DIAGNOSTIC 916 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 917 panic("malformed IPv4 option passed to ip_optcopy"); 918 #endif 919 /* bogus lengths should have been caught by ip_dooptions */ 920 if (optlen > cnt) 921 optlen = cnt; 922 if (IPOPT_COPIED(opt)) { 923 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 924 dp += optlen; 925 } 926 } 927 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 928 *dp++ = IPOPT_EOL; 929 return (optlen); 930 } 931 932 /* 933 * IP socket option processing. 934 */ 935 int 936 ip_ctloutput(op, so, level, optname, mp) 937 int op; 938 struct socket *so; 939 int level, optname; 940 struct mbuf **mp; 941 { 942 struct inpcb *inp = sotoinpcb(so); 943 struct mbuf *m = *mp; 944 int optval = 0; 945 int error = 0; 946 #ifdef IPSEC 947 #ifdef __NetBSD__ 948 struct proc *p = curproc; /*XXX*/ 949 #endif 950 #endif 951 952 if (level != IPPROTO_IP) { 953 error = EINVAL; 954 if (op == PRCO_SETOPT && *mp) 955 (void) m_free(*mp); 956 } else switch (op) { 957 958 case PRCO_SETOPT: 959 switch (optname) { 960 case IP_OPTIONS: 961 #ifdef notyet 962 case IP_RETOPTS: 963 return (ip_pcbopts(optname, &inp->inp_options, m)); 964 #else 965 return (ip_pcbopts(&inp->inp_options, m)); 966 #endif 967 968 case IP_TOS: 969 case IP_TTL: 970 case IP_RECVOPTS: 971 case IP_RECVRETOPTS: 972 case IP_RECVDSTADDR: 973 case IP_RECVIF: 974 if (m == NULL || m->m_len != sizeof(int)) 975 error = EINVAL; 976 else { 977 optval = *mtod(m, int *); 978 switch (optname) { 979 980 case IP_TOS: 981 inp->inp_ip.ip_tos = optval; 982 break; 983 984 case IP_TTL: 985 inp->inp_ip.ip_ttl = optval; 986 break; 987 #define OPTSET(bit) \ 988 if (optval) \ 989 inp->inp_flags |= bit; \ 990 else \ 991 inp->inp_flags &= ~bit; 992 993 case IP_RECVOPTS: 994 OPTSET(INP_RECVOPTS); 995 break; 996 997 case IP_RECVRETOPTS: 998 OPTSET(INP_RECVRETOPTS); 999 break; 1000 1001 case IP_RECVDSTADDR: 1002 OPTSET(INP_RECVDSTADDR); 1003 break; 1004 1005 case IP_RECVIF: 1006 OPTSET(INP_RECVIF); 1007 break; 1008 } 1009 } 1010 break; 1011 #undef OPTSET 1012 1013 case IP_MULTICAST_IF: 1014 case IP_MULTICAST_TTL: 1015 case IP_MULTICAST_LOOP: 1016 case IP_ADD_MEMBERSHIP: 1017 case IP_DROP_MEMBERSHIP: 1018 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1019 break; 1020 1021 case IP_PORTRANGE: 1022 if (m == 0 || m->m_len != sizeof(int)) 1023 error = EINVAL; 1024 else { 1025 optval = *mtod(m, int *); 1026 1027 switch (optval) { 1028 1029 case IP_PORTRANGE_DEFAULT: 1030 case IP_PORTRANGE_HIGH: 1031 inp->inp_flags &= ~(INP_LOWPORT); 1032 break; 1033 1034 case IP_PORTRANGE_LOW: 1035 inp->inp_flags |= INP_LOWPORT; 1036 break; 1037 1038 default: 1039 error = EINVAL; 1040 break; 1041 } 1042 } 1043 break; 1044 1045 #ifdef IPSEC 1046 case IP_IPSEC_POLICY: 1047 { 1048 caddr_t req = NULL; 1049 size_t len = 0; 1050 int priv = 0; 1051 1052 #ifdef __NetBSD__ 1053 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1054 priv = 0; 1055 else 1056 priv = 1; 1057 #else 1058 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1059 #endif 1060 if (m) { 1061 req = mtod(m, caddr_t); 1062 len = m->m_len; 1063 } 1064 error = ipsec4_set_policy(inp, optname, req, len, priv); 1065 break; 1066 } 1067 #endif /*IPSEC*/ 1068 1069 default: 1070 error = ENOPROTOOPT; 1071 break; 1072 } 1073 if (m) 1074 (void)m_free(m); 1075 break; 1076 1077 case PRCO_GETOPT: 1078 switch (optname) { 1079 case IP_OPTIONS: 1080 case IP_RETOPTS: 1081 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1082 MCLAIM(m, so->so_mowner); 1083 if (inp->inp_options) { 1084 m->m_len = inp->inp_options->m_len; 1085 bcopy(mtod(inp->inp_options, caddr_t), 1086 mtod(m, caddr_t), (unsigned)m->m_len); 1087 } else 1088 m->m_len = 0; 1089 break; 1090 1091 case IP_TOS: 1092 case IP_TTL: 1093 case IP_RECVOPTS: 1094 case IP_RECVRETOPTS: 1095 case IP_RECVDSTADDR: 1096 case IP_RECVIF: 1097 case IP_ERRORMTU: 1098 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1099 MCLAIM(m, so->so_mowner); 1100 m->m_len = sizeof(int); 1101 switch (optname) { 1102 1103 case IP_TOS: 1104 optval = inp->inp_ip.ip_tos; 1105 break; 1106 1107 case IP_TTL: 1108 optval = inp->inp_ip.ip_ttl; 1109 break; 1110 1111 case IP_ERRORMTU: 1112 optval = inp->inp_errormtu; 1113 break; 1114 1115 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1116 1117 case IP_RECVOPTS: 1118 optval = OPTBIT(INP_RECVOPTS); 1119 break; 1120 1121 case IP_RECVRETOPTS: 1122 optval = OPTBIT(INP_RECVRETOPTS); 1123 break; 1124 1125 case IP_RECVDSTADDR: 1126 optval = OPTBIT(INP_RECVDSTADDR); 1127 break; 1128 1129 case IP_RECVIF: 1130 optval = OPTBIT(INP_RECVIF); 1131 break; 1132 } 1133 *mtod(m, int *) = optval; 1134 break; 1135 1136 #ifdef IPSEC 1137 case IP_IPSEC_POLICY: 1138 { 1139 caddr_t req = NULL; 1140 size_t len = 0; 1141 1142 if (m) { 1143 req = mtod(m, caddr_t); 1144 len = m->m_len; 1145 } 1146 error = ipsec4_get_policy(inp, req, len, mp); 1147 break; 1148 } 1149 #endif /*IPSEC*/ 1150 1151 case IP_MULTICAST_IF: 1152 case IP_MULTICAST_TTL: 1153 case IP_MULTICAST_LOOP: 1154 case IP_ADD_MEMBERSHIP: 1155 case IP_DROP_MEMBERSHIP: 1156 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1157 if (*mp) 1158 MCLAIM(*mp, so->so_mowner); 1159 break; 1160 1161 case IP_PORTRANGE: 1162 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1163 MCLAIM(m, so->so_mowner); 1164 m->m_len = sizeof(int); 1165 1166 if (inp->inp_flags & INP_LOWPORT) 1167 optval = IP_PORTRANGE_LOW; 1168 else 1169 optval = IP_PORTRANGE_DEFAULT; 1170 1171 *mtod(m, int *) = optval; 1172 break; 1173 1174 default: 1175 error = ENOPROTOOPT; 1176 break; 1177 } 1178 break; 1179 } 1180 return (error); 1181 } 1182 1183 /* 1184 * Set up IP options in pcb for insertion in output packets. 1185 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1186 * with destination address if source routed. 1187 */ 1188 int 1189 #ifdef notyet 1190 ip_pcbopts(optname, pcbopt, m) 1191 int optname; 1192 #else 1193 ip_pcbopts(pcbopt, m) 1194 #endif 1195 struct mbuf **pcbopt; 1196 struct mbuf *m; 1197 { 1198 int cnt, optlen; 1199 u_char *cp; 1200 u_char opt; 1201 1202 /* turn off any old options */ 1203 if (*pcbopt) 1204 (void)m_free(*pcbopt); 1205 *pcbopt = 0; 1206 if (m == (struct mbuf *)0 || m->m_len == 0) { 1207 /* 1208 * Only turning off any previous options. 1209 */ 1210 if (m) 1211 (void)m_free(m); 1212 return (0); 1213 } 1214 1215 #ifndef __vax__ 1216 if (m->m_len % sizeof(int32_t)) 1217 goto bad; 1218 #endif 1219 /* 1220 * IP first-hop destination address will be stored before 1221 * actual options; move other options back 1222 * and clear it when none present. 1223 */ 1224 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1225 goto bad; 1226 cnt = m->m_len; 1227 m->m_len += sizeof(struct in_addr); 1228 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1229 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1230 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1231 1232 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1233 opt = cp[IPOPT_OPTVAL]; 1234 if (opt == IPOPT_EOL) 1235 break; 1236 if (opt == IPOPT_NOP) 1237 optlen = 1; 1238 else { 1239 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1240 goto bad; 1241 optlen = cp[IPOPT_OLEN]; 1242 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1243 goto bad; 1244 } 1245 switch (opt) { 1246 1247 default: 1248 break; 1249 1250 case IPOPT_LSRR: 1251 case IPOPT_SSRR: 1252 /* 1253 * user process specifies route as: 1254 * ->A->B->C->D 1255 * D must be our final destination (but we can't 1256 * check that since we may not have connected yet). 1257 * A is first hop destination, which doesn't appear in 1258 * actual IP option, but is stored before the options. 1259 */ 1260 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1261 goto bad; 1262 m->m_len -= sizeof(struct in_addr); 1263 cnt -= sizeof(struct in_addr); 1264 optlen -= sizeof(struct in_addr); 1265 cp[IPOPT_OLEN] = optlen; 1266 /* 1267 * Move first hop before start of options. 1268 */ 1269 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1270 sizeof(struct in_addr)); 1271 /* 1272 * Then copy rest of options back 1273 * to close up the deleted entry. 1274 */ 1275 memmove(&cp[IPOPT_OFFSET+1], 1276 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1277 (unsigned)cnt + sizeof(struct in_addr)); 1278 break; 1279 } 1280 } 1281 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1282 goto bad; 1283 *pcbopt = m; 1284 return (0); 1285 1286 bad: 1287 (void)m_free(m); 1288 return (EINVAL); 1289 } 1290 1291 /* 1292 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1293 */ 1294 static struct ifnet * 1295 ip_multicast_if(a, ifindexp) 1296 struct in_addr *a; 1297 int *ifindexp; 1298 { 1299 int ifindex; 1300 struct ifnet *ifp; 1301 1302 if (ifindexp) 1303 *ifindexp = 0; 1304 if (ntohl(a->s_addr) >> 24 == 0) { 1305 ifindex = ntohl(a->s_addr) & 0xffffff; 1306 if (ifindex < 0 || if_index < ifindex) 1307 return NULL; 1308 ifp = ifindex2ifnet[ifindex]; 1309 if (ifindexp) 1310 *ifindexp = ifindex; 1311 } else { 1312 INADDR_TO_IFP(*a, ifp); 1313 } 1314 return ifp; 1315 } 1316 1317 /* 1318 * Set the IP multicast options in response to user setsockopt(). 1319 */ 1320 int 1321 ip_setmoptions(optname, imop, m) 1322 int optname; 1323 struct ip_moptions **imop; 1324 struct mbuf *m; 1325 { 1326 int error = 0; 1327 u_char loop; 1328 int i; 1329 struct in_addr addr; 1330 struct ip_mreq *mreq; 1331 struct ifnet *ifp; 1332 struct ip_moptions *imo = *imop; 1333 struct route ro; 1334 struct sockaddr_in *dst; 1335 int ifindex; 1336 1337 if (imo == NULL) { 1338 /* 1339 * No multicast option buffer attached to the pcb; 1340 * allocate one and initialize to default values. 1341 */ 1342 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1343 M_WAITOK); 1344 1345 if (imo == NULL) 1346 return (ENOBUFS); 1347 *imop = imo; 1348 imo->imo_multicast_ifp = NULL; 1349 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1350 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1351 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1352 imo->imo_num_memberships = 0; 1353 } 1354 1355 switch (optname) { 1356 1357 case IP_MULTICAST_IF: 1358 /* 1359 * Select the interface for outgoing multicast packets. 1360 */ 1361 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1362 error = EINVAL; 1363 break; 1364 } 1365 addr = *(mtod(m, struct in_addr *)); 1366 /* 1367 * INADDR_ANY is used to remove a previous selection. 1368 * When no interface is selected, a default one is 1369 * chosen every time a multicast packet is sent. 1370 */ 1371 if (in_nullhost(addr)) { 1372 imo->imo_multicast_ifp = NULL; 1373 break; 1374 } 1375 /* 1376 * The selected interface is identified by its local 1377 * IP address. Find the interface and confirm that 1378 * it supports multicasting. 1379 */ 1380 ifp = ip_multicast_if(&addr, &ifindex); 1381 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1382 error = EADDRNOTAVAIL; 1383 break; 1384 } 1385 imo->imo_multicast_ifp = ifp; 1386 if (ifindex) 1387 imo->imo_multicast_addr = addr; 1388 else 1389 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1390 break; 1391 1392 case IP_MULTICAST_TTL: 1393 /* 1394 * Set the IP time-to-live for outgoing multicast packets. 1395 */ 1396 if (m == NULL || m->m_len != 1) { 1397 error = EINVAL; 1398 break; 1399 } 1400 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1401 break; 1402 1403 case IP_MULTICAST_LOOP: 1404 /* 1405 * Set the loopback flag for outgoing multicast packets. 1406 * Must be zero or one. 1407 */ 1408 if (m == NULL || m->m_len != 1 || 1409 (loop = *(mtod(m, u_char *))) > 1) { 1410 error = EINVAL; 1411 break; 1412 } 1413 imo->imo_multicast_loop = loop; 1414 break; 1415 1416 case IP_ADD_MEMBERSHIP: 1417 /* 1418 * Add a multicast group membership. 1419 * Group must be a valid IP multicast address. 1420 */ 1421 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1422 error = EINVAL; 1423 break; 1424 } 1425 mreq = mtod(m, struct ip_mreq *); 1426 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1427 error = EINVAL; 1428 break; 1429 } 1430 /* 1431 * If no interface address was provided, use the interface of 1432 * the route to the given multicast address. 1433 */ 1434 if (in_nullhost(mreq->imr_interface)) { 1435 bzero((caddr_t)&ro, sizeof(ro)); 1436 ro.ro_rt = NULL; 1437 dst = satosin(&ro.ro_dst); 1438 dst->sin_len = sizeof(*dst); 1439 dst->sin_family = AF_INET; 1440 dst->sin_addr = mreq->imr_multiaddr; 1441 rtalloc(&ro); 1442 if (ro.ro_rt == NULL) { 1443 error = EADDRNOTAVAIL; 1444 break; 1445 } 1446 ifp = ro.ro_rt->rt_ifp; 1447 rtfree(ro.ro_rt); 1448 } else { 1449 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1450 } 1451 /* 1452 * See if we found an interface, and confirm that it 1453 * supports multicast. 1454 */ 1455 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1456 error = EADDRNOTAVAIL; 1457 break; 1458 } 1459 /* 1460 * See if the membership already exists or if all the 1461 * membership slots are full. 1462 */ 1463 for (i = 0; i < imo->imo_num_memberships; ++i) { 1464 if (imo->imo_membership[i]->inm_ifp == ifp && 1465 in_hosteq(imo->imo_membership[i]->inm_addr, 1466 mreq->imr_multiaddr)) 1467 break; 1468 } 1469 if (i < imo->imo_num_memberships) { 1470 error = EADDRINUSE; 1471 break; 1472 } 1473 if (i == IP_MAX_MEMBERSHIPS) { 1474 error = ETOOMANYREFS; 1475 break; 1476 } 1477 /* 1478 * Everything looks good; add a new record to the multicast 1479 * address list for the given interface. 1480 */ 1481 if ((imo->imo_membership[i] = 1482 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1483 error = ENOBUFS; 1484 break; 1485 } 1486 ++imo->imo_num_memberships; 1487 break; 1488 1489 case IP_DROP_MEMBERSHIP: 1490 /* 1491 * Drop a multicast group membership. 1492 * Group must be a valid IP multicast address. 1493 */ 1494 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1495 error = EINVAL; 1496 break; 1497 } 1498 mreq = mtod(m, struct ip_mreq *); 1499 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1500 error = EINVAL; 1501 break; 1502 } 1503 /* 1504 * If an interface address was specified, get a pointer 1505 * to its ifnet structure. 1506 */ 1507 if (in_nullhost(mreq->imr_interface)) 1508 ifp = NULL; 1509 else { 1510 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1511 if (ifp == NULL) { 1512 error = EADDRNOTAVAIL; 1513 break; 1514 } 1515 } 1516 /* 1517 * Find the membership in the membership array. 1518 */ 1519 for (i = 0; i < imo->imo_num_memberships; ++i) { 1520 if ((ifp == NULL || 1521 imo->imo_membership[i]->inm_ifp == ifp) && 1522 in_hosteq(imo->imo_membership[i]->inm_addr, 1523 mreq->imr_multiaddr)) 1524 break; 1525 } 1526 if (i == imo->imo_num_memberships) { 1527 error = EADDRNOTAVAIL; 1528 break; 1529 } 1530 /* 1531 * Give up the multicast address record to which the 1532 * membership points. 1533 */ 1534 in_delmulti(imo->imo_membership[i]); 1535 /* 1536 * Remove the gap in the membership array. 1537 */ 1538 for (++i; i < imo->imo_num_memberships; ++i) 1539 imo->imo_membership[i-1] = imo->imo_membership[i]; 1540 --imo->imo_num_memberships; 1541 break; 1542 1543 default: 1544 error = EOPNOTSUPP; 1545 break; 1546 } 1547 1548 /* 1549 * If all options have default values, no need to keep the mbuf. 1550 */ 1551 if (imo->imo_multicast_ifp == NULL && 1552 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1553 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1554 imo->imo_num_memberships == 0) { 1555 free(*imop, M_IPMOPTS); 1556 *imop = NULL; 1557 } 1558 1559 return (error); 1560 } 1561 1562 /* 1563 * Return the IP multicast options in response to user getsockopt(). 1564 */ 1565 int 1566 ip_getmoptions(optname, imo, mp) 1567 int optname; 1568 struct ip_moptions *imo; 1569 struct mbuf **mp; 1570 { 1571 u_char *ttl; 1572 u_char *loop; 1573 struct in_addr *addr; 1574 struct in_ifaddr *ia; 1575 1576 *mp = m_get(M_WAIT, MT_SOOPTS); 1577 1578 switch (optname) { 1579 1580 case IP_MULTICAST_IF: 1581 addr = mtod(*mp, struct in_addr *); 1582 (*mp)->m_len = sizeof(struct in_addr); 1583 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1584 *addr = zeroin_addr; 1585 else if (imo->imo_multicast_addr.s_addr) { 1586 /* return the value user has set */ 1587 *addr = imo->imo_multicast_addr; 1588 } else { 1589 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1590 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1591 } 1592 return (0); 1593 1594 case IP_MULTICAST_TTL: 1595 ttl = mtod(*mp, u_char *); 1596 (*mp)->m_len = 1; 1597 *ttl = imo ? imo->imo_multicast_ttl 1598 : IP_DEFAULT_MULTICAST_TTL; 1599 return (0); 1600 1601 case IP_MULTICAST_LOOP: 1602 loop = mtod(*mp, u_char *); 1603 (*mp)->m_len = 1; 1604 *loop = imo ? imo->imo_multicast_loop 1605 : IP_DEFAULT_MULTICAST_LOOP; 1606 return (0); 1607 1608 default: 1609 return (EOPNOTSUPP); 1610 } 1611 } 1612 1613 /* 1614 * Discard the IP multicast options. 1615 */ 1616 void 1617 ip_freemoptions(imo) 1618 struct ip_moptions *imo; 1619 { 1620 int i; 1621 1622 if (imo != NULL) { 1623 for (i = 0; i < imo->imo_num_memberships; ++i) 1624 in_delmulti(imo->imo_membership[i]); 1625 free(imo, M_IPMOPTS); 1626 } 1627 } 1628 1629 /* 1630 * Routine called from ip_output() to loop back a copy of an IP multicast 1631 * packet to the input queue of a specified interface. Note that this 1632 * calls the output routine of the loopback "driver", but with an interface 1633 * pointer that might NOT be &loif -- easier than replicating that code here. 1634 */ 1635 static void 1636 ip_mloopback(ifp, m, dst) 1637 struct ifnet *ifp; 1638 struct mbuf *m; 1639 struct sockaddr_in *dst; 1640 { 1641 struct ip *ip; 1642 struct mbuf *copym; 1643 1644 copym = m_copy(m, 0, M_COPYALL); 1645 if (copym != NULL 1646 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1647 copym = m_pullup(copym, sizeof(struct ip)); 1648 if (copym != NULL) { 1649 /* 1650 * We don't bother to fragment if the IP length is greater 1651 * than the interface's MTU. Can this possibly matter? 1652 */ 1653 ip = mtod(copym, struct ip *); 1654 1655 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1656 in_delayed_cksum(copym); 1657 copym->m_pkthdr.csum_flags &= 1658 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1659 } 1660 1661 ip->ip_sum = 0; 1662 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1663 (void) looutput(ifp, copym, sintosa(dst), NULL); 1664 } 1665 } 1666