1 /* $NetBSD: ip_output.c,v 1.107 2003/06/30 02:08:28 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 1.107 2003/06/30 02:08:28 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 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 hlen = ip->ip_hl << 2; 562 ip_len = ntohs(ip->ip_len); 563 564 if (ro->ro_rt == NULL) { 565 if ((flags & IP_ROUTETOIF) == 0) { 566 printf("ip_output: " 567 "can't update route after IPsec processing\n"); 568 error = EHOSTUNREACH; /*XXX*/ 569 goto bad; 570 } 571 } else { 572 /* nobody uses ia beyond here */ 573 if (state.encap) 574 ifp = ro->ro_rt->rt_ifp; 575 } 576 } 577 578 skip_ipsec: 579 #endif /*IPSEC*/ 580 581 #ifdef PFIL_HOOKS 582 /* 583 * Run through list of hooks for output packets. 584 */ 585 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) 586 goto done; 587 if (m == NULL) 588 goto done; 589 590 ip = mtod(m, struct ip *); 591 hlen = ip->ip_hl << 2; 592 #endif /* PFIL_HOOKS */ 593 594 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 595 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 596 /* 597 * If small enough for mtu of path, can just send directly. 598 */ 599 if (ip_len <= mtu) { 600 #if IFA_STATS 601 /* 602 * search for the source address structure to 603 * maintain output statistics. 604 */ 605 INADDR_TO_IA(ip->ip_src, ia); 606 if (ia) 607 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 608 #endif 609 /* 610 * Always initialize the sum to 0! Some HW assisted 611 * checksumming requires this. 612 */ 613 ip->ip_sum = 0; 614 615 /* 616 * Perform any checksums that the hardware can't do 617 * for us. 618 * 619 * XXX Does any hardware require the {th,uh}_sum 620 * XXX fields to be 0? 621 */ 622 if (sw_csum & M_CSUM_IPv4) { 623 ip->ip_sum = in_cksum(m, hlen); 624 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 625 } 626 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 627 in_delayed_cksum(m); 628 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 629 } 630 631 #ifdef IPSEC 632 /* clean ipsec history once it goes out of the node */ 633 ipsec_delaux(m); 634 #endif 635 error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 636 goto done; 637 } 638 639 /* 640 * We can't use HW checksumming if we're about to 641 * to fragment the packet. 642 * 643 * XXX Some hardware can do this. 644 */ 645 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 646 in_delayed_cksum(m); 647 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 648 } 649 650 /* 651 * Too large for interface; fragment if possible. 652 * Must be able to put at least 8 bytes per fragment. 653 */ 654 if (ntohs(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 < ntohs(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 MCLAIM(m, m0->m_owner); 687 *mnext = m; 688 mnext = &m->m_nextpkt; 689 m->m_data += max_linkhdr; 690 mhip = mtod(m, struct ip *); 691 *mhip = *ip; 692 /* we must inherit MCAST and BCAST flags */ 693 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 694 if (hlen > sizeof (struct ip)) { 695 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 696 mhip->ip_hl = mhlen >> 2; 697 } 698 m->m_len = mhlen; 699 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 700 if (ip->ip_off & IP_MF) 701 mhip->ip_off |= IP_MF; 702 if (off + len >= ntohs(ip->ip_len)) 703 len = ntohs(ip->ip_len) - off; 704 else 705 mhip->ip_off |= IP_MF; 706 HTONS(mhip->ip_off); 707 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 708 m->m_next = m_copy(m0, off, len); 709 if (m->m_next == 0) { 710 error = ENOBUFS; /* ??? */ 711 ipstat.ips_odropped++; 712 goto sendorfree; 713 } 714 m->m_pkthdr.len = mhlen + len; 715 m->m_pkthdr.rcvif = (struct ifnet *)0; 716 mhip->ip_sum = 0; 717 if (sw_csum & M_CSUM_IPv4) { 718 mhip->ip_sum = in_cksum(m, mhlen); 719 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 720 } else { 721 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 722 } 723 ipstat.ips_ofragments++; 724 fragments++; 725 } 726 /* 727 * Update first fragment by trimming what's been copied out 728 * and updating header, then send each fragment (in order). 729 */ 730 m = m0; 731 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 732 m->m_pkthdr.len = hlen + firstlen; 733 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 734 ip->ip_off |= htons(IP_MF); 735 ip->ip_sum = 0; 736 if (sw_csum & M_CSUM_IPv4) { 737 ip->ip_sum = in_cksum(m, hlen); 738 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 739 } else { 740 KASSERT(m->m_pkthdr.csum_flags & M_CSUM_IPv4); 741 } 742 sendorfree: 743 /* 744 * If there is no room for all the fragments, don't queue 745 * any of them. 746 */ 747 s = splnet(); 748 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments) 749 error = ENOBUFS; 750 splx(s); 751 for (m = m0; m; m = m0) { 752 m0 = m->m_nextpkt; 753 m->m_nextpkt = 0; 754 if (error == 0) { 755 #if IFA_STATS 756 /* 757 * search for the source address structure to 758 * maintain output statistics. 759 */ 760 INADDR_TO_IA(ip->ip_src, ia); 761 if (ia) { 762 ia->ia_ifa.ifa_data.ifad_outbytes += 763 ntohs(ip->ip_len); 764 } 765 #endif 766 #ifdef IPSEC 767 /* clean ipsec history once it goes out of the node */ 768 ipsec_delaux(m); 769 #endif 770 KASSERT((m->m_pkthdr.csum_flags & 771 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 772 error = (*ifp->if_output)(ifp, m, sintosa(dst), 773 ro->ro_rt); 774 } else 775 m_freem(m); 776 } 777 778 if (error == 0) 779 ipstat.ips_fragmented++; 780 } 781 done: 782 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 783 RTFREE(ro->ro_rt); 784 ro->ro_rt = 0; 785 } 786 787 #ifdef IPSEC 788 if (sp != NULL) { 789 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 790 printf("DP ip_output call free SP:%p\n", sp)); 791 key_freesp(sp); 792 } 793 #endif /* IPSEC */ 794 795 return (error); 796 bad: 797 m_freem(m); 798 goto done; 799 } 800 801 /* 802 * Process a delayed payload checksum calculation. 803 */ 804 void 805 in_delayed_cksum(struct mbuf *m) 806 { 807 struct ip *ip; 808 u_int16_t csum, offset; 809 810 ip = mtod(m, struct ip *); 811 offset = ip->ip_hl << 2; 812 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 813 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 814 csum = 0xffff; 815 816 offset += m->m_pkthdr.csum_data; /* checksum offset */ 817 818 if ((offset + sizeof(u_int16_t)) > m->m_len) { 819 /* This happen when ip options were inserted 820 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 821 m->m_len, offset, ip->ip_p); 822 */ 823 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 824 } else 825 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 826 } 827 828 /* 829 * Determine the maximum length of the options to be inserted; 830 * we would far rather allocate too much space rather than too little. 831 */ 832 833 u_int 834 ip_optlen(inp) 835 struct inpcb *inp; 836 { 837 struct mbuf *m = inp->inp_options; 838 839 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 840 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 841 else 842 return 0; 843 } 844 845 846 /* 847 * Insert IP options into preformed packet. 848 * Adjust IP destination as required for IP source routing, 849 * as indicated by a non-zero in_addr at the start of the options. 850 */ 851 static struct mbuf * 852 ip_insertoptions(m, opt, phlen) 853 struct mbuf *m; 854 struct mbuf *opt; 855 int *phlen; 856 { 857 struct ipoption *p = mtod(opt, struct ipoption *); 858 struct mbuf *n; 859 struct ip *ip = mtod(m, struct ip *); 860 unsigned optlen; 861 862 optlen = opt->m_len - sizeof(p->ipopt_dst); 863 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 864 return (m); /* XXX should fail */ 865 if (!in_nullhost(p->ipopt_dst)) 866 ip->ip_dst = p->ipopt_dst; 867 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 868 MGETHDR(n, M_DONTWAIT, MT_HEADER); 869 if (n == 0) 870 return (m); 871 MCLAIM(n, m->m_owner); 872 M_COPY_PKTHDR(n, m); 873 m->m_flags &= ~M_PKTHDR; 874 m->m_len -= sizeof(struct ip); 875 m->m_data += sizeof(struct ip); 876 n->m_next = m; 877 m = n; 878 m->m_len = optlen + sizeof(struct ip); 879 m->m_data += max_linkhdr; 880 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 881 } else { 882 m->m_data -= optlen; 883 m->m_len += optlen; 884 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 885 } 886 m->m_pkthdr.len += optlen; 887 ip = mtod(m, struct ip *); 888 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 889 *phlen = sizeof(struct ip) + optlen; 890 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 891 return (m); 892 } 893 894 /* 895 * Copy options from ip to jp, 896 * omitting those not copied during fragmentation. 897 */ 898 int 899 ip_optcopy(ip, jp) 900 struct ip *ip, *jp; 901 { 902 u_char *cp, *dp; 903 int opt, optlen, cnt; 904 905 cp = (u_char *)(ip + 1); 906 dp = (u_char *)(jp + 1); 907 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 908 for (; cnt > 0; cnt -= optlen, cp += optlen) { 909 opt = cp[0]; 910 if (opt == IPOPT_EOL) 911 break; 912 if (opt == IPOPT_NOP) { 913 /* Preserve for IP mcast tunnel's LSRR alignment. */ 914 *dp++ = IPOPT_NOP; 915 optlen = 1; 916 continue; 917 } 918 #ifdef DIAGNOSTIC 919 if (cnt < IPOPT_OLEN + sizeof(*cp)) 920 panic("malformed IPv4 option passed to ip_optcopy"); 921 #endif 922 optlen = cp[IPOPT_OLEN]; 923 #ifdef DIAGNOSTIC 924 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 925 panic("malformed IPv4 option passed to ip_optcopy"); 926 #endif 927 /* bogus lengths should have been caught by ip_dooptions */ 928 if (optlen > cnt) 929 optlen = cnt; 930 if (IPOPT_COPIED(opt)) { 931 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 932 dp += optlen; 933 } 934 } 935 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 936 *dp++ = IPOPT_EOL; 937 return (optlen); 938 } 939 940 /* 941 * IP socket option processing. 942 */ 943 int 944 ip_ctloutput(op, so, level, optname, mp) 945 int op; 946 struct socket *so; 947 int level, optname; 948 struct mbuf **mp; 949 { 950 struct inpcb *inp = sotoinpcb(so); 951 struct mbuf *m = *mp; 952 int optval = 0; 953 int error = 0; 954 #ifdef IPSEC 955 #ifdef __NetBSD__ 956 struct proc *p = curproc; /*XXX*/ 957 #endif 958 #endif 959 960 if (level != IPPROTO_IP) { 961 error = EINVAL; 962 if (op == PRCO_SETOPT && *mp) 963 (void) m_free(*mp); 964 } else switch (op) { 965 966 case PRCO_SETOPT: 967 switch (optname) { 968 case IP_OPTIONS: 969 #ifdef notyet 970 case IP_RETOPTS: 971 return (ip_pcbopts(optname, &inp->inp_options, m)); 972 #else 973 return (ip_pcbopts(&inp->inp_options, m)); 974 #endif 975 976 case IP_TOS: 977 case IP_TTL: 978 case IP_RECVOPTS: 979 case IP_RECVRETOPTS: 980 case IP_RECVDSTADDR: 981 case IP_RECVIF: 982 if (m == NULL || m->m_len != sizeof(int)) 983 error = EINVAL; 984 else { 985 optval = *mtod(m, int *); 986 switch (optname) { 987 988 case IP_TOS: 989 inp->inp_ip.ip_tos = optval; 990 break; 991 992 case IP_TTL: 993 inp->inp_ip.ip_ttl = optval; 994 break; 995 #define OPTSET(bit) \ 996 if (optval) \ 997 inp->inp_flags |= bit; \ 998 else \ 999 inp->inp_flags &= ~bit; 1000 1001 case IP_RECVOPTS: 1002 OPTSET(INP_RECVOPTS); 1003 break; 1004 1005 case IP_RECVRETOPTS: 1006 OPTSET(INP_RECVRETOPTS); 1007 break; 1008 1009 case IP_RECVDSTADDR: 1010 OPTSET(INP_RECVDSTADDR); 1011 break; 1012 1013 case IP_RECVIF: 1014 OPTSET(INP_RECVIF); 1015 break; 1016 } 1017 } 1018 break; 1019 #undef OPTSET 1020 1021 case IP_MULTICAST_IF: 1022 case IP_MULTICAST_TTL: 1023 case IP_MULTICAST_LOOP: 1024 case IP_ADD_MEMBERSHIP: 1025 case IP_DROP_MEMBERSHIP: 1026 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1027 break; 1028 1029 case IP_PORTRANGE: 1030 if (m == 0 || m->m_len != sizeof(int)) 1031 error = EINVAL; 1032 else { 1033 optval = *mtod(m, int *); 1034 1035 switch (optval) { 1036 1037 case IP_PORTRANGE_DEFAULT: 1038 case IP_PORTRANGE_HIGH: 1039 inp->inp_flags &= ~(INP_LOWPORT); 1040 break; 1041 1042 case IP_PORTRANGE_LOW: 1043 inp->inp_flags |= INP_LOWPORT; 1044 break; 1045 1046 default: 1047 error = EINVAL; 1048 break; 1049 } 1050 } 1051 break; 1052 1053 #ifdef IPSEC 1054 case IP_IPSEC_POLICY: 1055 { 1056 caddr_t req = NULL; 1057 size_t len = 0; 1058 int priv = 0; 1059 1060 #ifdef __NetBSD__ 1061 if (p == 0 || suser(p->p_ucred, &p->p_acflag)) 1062 priv = 0; 1063 else 1064 priv = 1; 1065 #else 1066 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1067 #endif 1068 if (m) { 1069 req = mtod(m, caddr_t); 1070 len = m->m_len; 1071 } 1072 error = ipsec4_set_policy(inp, optname, req, len, priv); 1073 break; 1074 } 1075 #endif /*IPSEC*/ 1076 1077 default: 1078 error = ENOPROTOOPT; 1079 break; 1080 } 1081 if (m) 1082 (void)m_free(m); 1083 break; 1084 1085 case PRCO_GETOPT: 1086 switch (optname) { 1087 case IP_OPTIONS: 1088 case IP_RETOPTS: 1089 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1090 MCLAIM(m, so->so_mowner); 1091 if (inp->inp_options) { 1092 m->m_len = inp->inp_options->m_len; 1093 bcopy(mtod(inp->inp_options, caddr_t), 1094 mtod(m, caddr_t), (unsigned)m->m_len); 1095 } else 1096 m->m_len = 0; 1097 break; 1098 1099 case IP_TOS: 1100 case IP_TTL: 1101 case IP_RECVOPTS: 1102 case IP_RECVRETOPTS: 1103 case IP_RECVDSTADDR: 1104 case IP_RECVIF: 1105 case IP_ERRORMTU: 1106 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1107 MCLAIM(m, so->so_mowner); 1108 m->m_len = sizeof(int); 1109 switch (optname) { 1110 1111 case IP_TOS: 1112 optval = inp->inp_ip.ip_tos; 1113 break; 1114 1115 case IP_TTL: 1116 optval = inp->inp_ip.ip_ttl; 1117 break; 1118 1119 case IP_ERRORMTU: 1120 optval = inp->inp_errormtu; 1121 break; 1122 1123 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1124 1125 case IP_RECVOPTS: 1126 optval = OPTBIT(INP_RECVOPTS); 1127 break; 1128 1129 case IP_RECVRETOPTS: 1130 optval = OPTBIT(INP_RECVRETOPTS); 1131 break; 1132 1133 case IP_RECVDSTADDR: 1134 optval = OPTBIT(INP_RECVDSTADDR); 1135 break; 1136 1137 case IP_RECVIF: 1138 optval = OPTBIT(INP_RECVIF); 1139 break; 1140 } 1141 *mtod(m, int *) = optval; 1142 break; 1143 1144 #ifdef IPSEC 1145 case IP_IPSEC_POLICY: 1146 { 1147 caddr_t req = NULL; 1148 size_t len = 0; 1149 1150 if (m) { 1151 req = mtod(m, caddr_t); 1152 len = m->m_len; 1153 } 1154 error = ipsec4_get_policy(inp, req, len, mp); 1155 break; 1156 } 1157 #endif /*IPSEC*/ 1158 1159 case IP_MULTICAST_IF: 1160 case IP_MULTICAST_TTL: 1161 case IP_MULTICAST_LOOP: 1162 case IP_ADD_MEMBERSHIP: 1163 case IP_DROP_MEMBERSHIP: 1164 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1165 if (*mp) 1166 MCLAIM(*mp, so->so_mowner); 1167 break; 1168 1169 case IP_PORTRANGE: 1170 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1171 MCLAIM(m, so->so_mowner); 1172 m->m_len = sizeof(int); 1173 1174 if (inp->inp_flags & INP_LOWPORT) 1175 optval = IP_PORTRANGE_LOW; 1176 else 1177 optval = IP_PORTRANGE_DEFAULT; 1178 1179 *mtod(m, int *) = optval; 1180 break; 1181 1182 default: 1183 error = ENOPROTOOPT; 1184 break; 1185 } 1186 break; 1187 } 1188 return (error); 1189 } 1190 1191 /* 1192 * Set up IP options in pcb for insertion in output packets. 1193 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1194 * with destination address if source routed. 1195 */ 1196 int 1197 #ifdef notyet 1198 ip_pcbopts(optname, pcbopt, m) 1199 int optname; 1200 #else 1201 ip_pcbopts(pcbopt, m) 1202 #endif 1203 struct mbuf **pcbopt; 1204 struct mbuf *m; 1205 { 1206 int cnt, optlen; 1207 u_char *cp; 1208 u_char opt; 1209 1210 /* turn off any old options */ 1211 if (*pcbopt) 1212 (void)m_free(*pcbopt); 1213 *pcbopt = 0; 1214 if (m == (struct mbuf *)0 || m->m_len == 0) { 1215 /* 1216 * Only turning off any previous options. 1217 */ 1218 if (m) 1219 (void)m_free(m); 1220 return (0); 1221 } 1222 1223 #ifndef __vax__ 1224 if (m->m_len % sizeof(int32_t)) 1225 goto bad; 1226 #endif 1227 /* 1228 * IP first-hop destination address will be stored before 1229 * actual options; move other options back 1230 * and clear it when none present. 1231 */ 1232 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1233 goto bad; 1234 cnt = m->m_len; 1235 m->m_len += sizeof(struct in_addr); 1236 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1237 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1238 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1239 1240 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1241 opt = cp[IPOPT_OPTVAL]; 1242 if (opt == IPOPT_EOL) 1243 break; 1244 if (opt == IPOPT_NOP) 1245 optlen = 1; 1246 else { 1247 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1248 goto bad; 1249 optlen = cp[IPOPT_OLEN]; 1250 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1251 goto bad; 1252 } 1253 switch (opt) { 1254 1255 default: 1256 break; 1257 1258 case IPOPT_LSRR: 1259 case IPOPT_SSRR: 1260 /* 1261 * user process specifies route as: 1262 * ->A->B->C->D 1263 * D must be our final destination (but we can't 1264 * check that since we may not have connected yet). 1265 * A is first hop destination, which doesn't appear in 1266 * actual IP option, but is stored before the options. 1267 */ 1268 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1269 goto bad; 1270 m->m_len -= sizeof(struct in_addr); 1271 cnt -= sizeof(struct in_addr); 1272 optlen -= sizeof(struct in_addr); 1273 cp[IPOPT_OLEN] = optlen; 1274 /* 1275 * Move first hop before start of options. 1276 */ 1277 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1278 sizeof(struct in_addr)); 1279 /* 1280 * Then copy rest of options back 1281 * to close up the deleted entry. 1282 */ 1283 memmove(&cp[IPOPT_OFFSET+1], 1284 (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 1285 (unsigned)cnt + sizeof(struct in_addr)); 1286 break; 1287 } 1288 } 1289 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1290 goto bad; 1291 *pcbopt = m; 1292 return (0); 1293 1294 bad: 1295 (void)m_free(m); 1296 return (EINVAL); 1297 } 1298 1299 /* 1300 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1301 */ 1302 static struct ifnet * 1303 ip_multicast_if(a, ifindexp) 1304 struct in_addr *a; 1305 int *ifindexp; 1306 { 1307 int ifindex; 1308 struct ifnet *ifp; 1309 1310 if (ifindexp) 1311 *ifindexp = 0; 1312 if (ntohl(a->s_addr) >> 24 == 0) { 1313 ifindex = ntohl(a->s_addr) & 0xffffff; 1314 if (ifindex < 0 || if_index < ifindex) 1315 return NULL; 1316 ifp = ifindex2ifnet[ifindex]; 1317 if (ifindexp) 1318 *ifindexp = ifindex; 1319 } else { 1320 INADDR_TO_IFP(*a, ifp); 1321 } 1322 return ifp; 1323 } 1324 1325 /* 1326 * Set the IP multicast options in response to user setsockopt(). 1327 */ 1328 int 1329 ip_setmoptions(optname, imop, m) 1330 int optname; 1331 struct ip_moptions **imop; 1332 struct mbuf *m; 1333 { 1334 int error = 0; 1335 u_char loop; 1336 int i; 1337 struct in_addr addr; 1338 struct ip_mreq *mreq; 1339 struct ifnet *ifp; 1340 struct ip_moptions *imo = *imop; 1341 struct route ro; 1342 struct sockaddr_in *dst; 1343 int ifindex; 1344 1345 if (imo == NULL) { 1346 /* 1347 * No multicast option buffer attached to the pcb; 1348 * allocate one and initialize to default values. 1349 */ 1350 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1351 M_WAITOK); 1352 1353 if (imo == NULL) 1354 return (ENOBUFS); 1355 *imop = imo; 1356 imo->imo_multicast_ifp = NULL; 1357 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1358 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1359 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1360 imo->imo_num_memberships = 0; 1361 } 1362 1363 switch (optname) { 1364 1365 case IP_MULTICAST_IF: 1366 /* 1367 * Select the interface for outgoing multicast packets. 1368 */ 1369 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1370 error = EINVAL; 1371 break; 1372 } 1373 addr = *(mtod(m, struct in_addr *)); 1374 /* 1375 * INADDR_ANY is used to remove a previous selection. 1376 * When no interface is selected, a default one is 1377 * chosen every time a multicast packet is sent. 1378 */ 1379 if (in_nullhost(addr)) { 1380 imo->imo_multicast_ifp = NULL; 1381 break; 1382 } 1383 /* 1384 * The selected interface is identified by its local 1385 * IP address. Find the interface and confirm that 1386 * it supports multicasting. 1387 */ 1388 ifp = ip_multicast_if(&addr, &ifindex); 1389 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1390 error = EADDRNOTAVAIL; 1391 break; 1392 } 1393 imo->imo_multicast_ifp = ifp; 1394 if (ifindex) 1395 imo->imo_multicast_addr = addr; 1396 else 1397 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1398 break; 1399 1400 case IP_MULTICAST_TTL: 1401 /* 1402 * Set the IP time-to-live for outgoing multicast packets. 1403 */ 1404 if (m == NULL || m->m_len != 1) { 1405 error = EINVAL; 1406 break; 1407 } 1408 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1409 break; 1410 1411 case IP_MULTICAST_LOOP: 1412 /* 1413 * Set the loopback flag for outgoing multicast packets. 1414 * Must be zero or one. 1415 */ 1416 if (m == NULL || m->m_len != 1 || 1417 (loop = *(mtod(m, u_char *))) > 1) { 1418 error = EINVAL; 1419 break; 1420 } 1421 imo->imo_multicast_loop = loop; 1422 break; 1423 1424 case IP_ADD_MEMBERSHIP: 1425 /* 1426 * Add a multicast group membership. 1427 * Group must be a valid IP multicast address. 1428 */ 1429 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1430 error = EINVAL; 1431 break; 1432 } 1433 mreq = mtod(m, struct ip_mreq *); 1434 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1435 error = EINVAL; 1436 break; 1437 } 1438 /* 1439 * If no interface address was provided, use the interface of 1440 * the route to the given multicast address. 1441 */ 1442 if (in_nullhost(mreq->imr_interface)) { 1443 bzero((caddr_t)&ro, sizeof(ro)); 1444 ro.ro_rt = NULL; 1445 dst = satosin(&ro.ro_dst); 1446 dst->sin_len = sizeof(*dst); 1447 dst->sin_family = AF_INET; 1448 dst->sin_addr = mreq->imr_multiaddr; 1449 rtalloc(&ro); 1450 if (ro.ro_rt == NULL) { 1451 error = EADDRNOTAVAIL; 1452 break; 1453 } 1454 ifp = ro.ro_rt->rt_ifp; 1455 rtfree(ro.ro_rt); 1456 } else { 1457 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1458 } 1459 /* 1460 * See if we found an interface, and confirm that it 1461 * supports multicast. 1462 */ 1463 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1464 error = EADDRNOTAVAIL; 1465 break; 1466 } 1467 /* 1468 * See if the membership already exists or if all the 1469 * membership slots are full. 1470 */ 1471 for (i = 0; i < imo->imo_num_memberships; ++i) { 1472 if (imo->imo_membership[i]->inm_ifp == ifp && 1473 in_hosteq(imo->imo_membership[i]->inm_addr, 1474 mreq->imr_multiaddr)) 1475 break; 1476 } 1477 if (i < imo->imo_num_memberships) { 1478 error = EADDRINUSE; 1479 break; 1480 } 1481 if (i == IP_MAX_MEMBERSHIPS) { 1482 error = ETOOMANYREFS; 1483 break; 1484 } 1485 /* 1486 * Everything looks good; add a new record to the multicast 1487 * address list for the given interface. 1488 */ 1489 if ((imo->imo_membership[i] = 1490 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1491 error = ENOBUFS; 1492 break; 1493 } 1494 ++imo->imo_num_memberships; 1495 break; 1496 1497 case IP_DROP_MEMBERSHIP: 1498 /* 1499 * Drop a multicast group membership. 1500 * Group must be a valid IP multicast address. 1501 */ 1502 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1503 error = EINVAL; 1504 break; 1505 } 1506 mreq = mtod(m, struct ip_mreq *); 1507 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1508 error = EINVAL; 1509 break; 1510 } 1511 /* 1512 * If an interface address was specified, get a pointer 1513 * to its ifnet structure. 1514 */ 1515 if (in_nullhost(mreq->imr_interface)) 1516 ifp = NULL; 1517 else { 1518 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1519 if (ifp == NULL) { 1520 error = EADDRNOTAVAIL; 1521 break; 1522 } 1523 } 1524 /* 1525 * Find the membership in the membership array. 1526 */ 1527 for (i = 0; i < imo->imo_num_memberships; ++i) { 1528 if ((ifp == NULL || 1529 imo->imo_membership[i]->inm_ifp == ifp) && 1530 in_hosteq(imo->imo_membership[i]->inm_addr, 1531 mreq->imr_multiaddr)) 1532 break; 1533 } 1534 if (i == imo->imo_num_memberships) { 1535 error = EADDRNOTAVAIL; 1536 break; 1537 } 1538 /* 1539 * Give up the multicast address record to which the 1540 * membership points. 1541 */ 1542 in_delmulti(imo->imo_membership[i]); 1543 /* 1544 * Remove the gap in the membership array. 1545 */ 1546 for (++i; i < imo->imo_num_memberships; ++i) 1547 imo->imo_membership[i-1] = imo->imo_membership[i]; 1548 --imo->imo_num_memberships; 1549 break; 1550 1551 default: 1552 error = EOPNOTSUPP; 1553 break; 1554 } 1555 1556 /* 1557 * If all options have default values, no need to keep the mbuf. 1558 */ 1559 if (imo->imo_multicast_ifp == NULL && 1560 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1561 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1562 imo->imo_num_memberships == 0) { 1563 free(*imop, M_IPMOPTS); 1564 *imop = NULL; 1565 } 1566 1567 return (error); 1568 } 1569 1570 /* 1571 * Return the IP multicast options in response to user getsockopt(). 1572 */ 1573 int 1574 ip_getmoptions(optname, imo, mp) 1575 int optname; 1576 struct ip_moptions *imo; 1577 struct mbuf **mp; 1578 { 1579 u_char *ttl; 1580 u_char *loop; 1581 struct in_addr *addr; 1582 struct in_ifaddr *ia; 1583 1584 *mp = m_get(M_WAIT, MT_SOOPTS); 1585 1586 switch (optname) { 1587 1588 case IP_MULTICAST_IF: 1589 addr = mtod(*mp, struct in_addr *); 1590 (*mp)->m_len = sizeof(struct in_addr); 1591 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1592 *addr = zeroin_addr; 1593 else if (imo->imo_multicast_addr.s_addr) { 1594 /* return the value user has set */ 1595 *addr = imo->imo_multicast_addr; 1596 } else { 1597 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1598 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1599 } 1600 return (0); 1601 1602 case IP_MULTICAST_TTL: 1603 ttl = mtod(*mp, u_char *); 1604 (*mp)->m_len = 1; 1605 *ttl = imo ? imo->imo_multicast_ttl 1606 : IP_DEFAULT_MULTICAST_TTL; 1607 return (0); 1608 1609 case IP_MULTICAST_LOOP: 1610 loop = mtod(*mp, u_char *); 1611 (*mp)->m_len = 1; 1612 *loop = imo ? imo->imo_multicast_loop 1613 : IP_DEFAULT_MULTICAST_LOOP; 1614 return (0); 1615 1616 default: 1617 return (EOPNOTSUPP); 1618 } 1619 } 1620 1621 /* 1622 * Discard the IP multicast options. 1623 */ 1624 void 1625 ip_freemoptions(imo) 1626 struct ip_moptions *imo; 1627 { 1628 int i; 1629 1630 if (imo != NULL) { 1631 for (i = 0; i < imo->imo_num_memberships; ++i) 1632 in_delmulti(imo->imo_membership[i]); 1633 free(imo, M_IPMOPTS); 1634 } 1635 } 1636 1637 /* 1638 * Routine called from ip_output() to loop back a copy of an IP multicast 1639 * packet to the input queue of a specified interface. Note that this 1640 * calls the output routine of the loopback "driver", but with an interface 1641 * pointer that might NOT be &loif -- easier than replicating that code here. 1642 */ 1643 static void 1644 ip_mloopback(ifp, m, dst) 1645 struct ifnet *ifp; 1646 struct mbuf *m; 1647 struct sockaddr_in *dst; 1648 { 1649 struct ip *ip; 1650 struct mbuf *copym; 1651 1652 copym = m_copy(m, 0, M_COPYALL); 1653 if (copym != NULL 1654 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1655 copym = m_pullup(copym, sizeof(struct ip)); 1656 if (copym != NULL) { 1657 /* 1658 * We don't bother to fragment if the IP length is greater 1659 * than the interface's MTU. Can this possibly matter? 1660 */ 1661 ip = mtod(copym, struct ip *); 1662 1663 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1664 in_delayed_cksum(copym); 1665 copym->m_pkthdr.csum_flags &= 1666 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1667 } 1668 1669 ip->ip_sum = 0; 1670 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1671 (void) looutput(ifp, copym, sintosa(dst), NULL); 1672 } 1673 } 1674