1 /* $NetBSD: ip_output.c,v 1.165 2006/07/23 22:06:13 ad 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. Neither the name of the University nor the names of its contributors 82 * may be used to endorse or promote products derived from this software 83 * without specific prior written permission. 84 * 85 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 86 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 87 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 88 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 89 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 90 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 91 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 92 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 93 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 94 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 95 * SUCH DAMAGE. 96 * 97 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 98 */ 99 100 #include <sys/cdefs.h> 101 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.165 2006/07/23 22:06:13 ad Exp $"); 102 103 #include "opt_pfil_hooks.h" 104 #include "opt_inet.h" 105 #include "opt_ipsec.h" 106 #include "opt_mrouting.h" 107 108 #include <sys/param.h> 109 #include <sys/malloc.h> 110 #include <sys/mbuf.h> 111 #include <sys/errno.h> 112 #include <sys/protosw.h> 113 #include <sys/socket.h> 114 #include <sys/socketvar.h> 115 #include <sys/kauth.h> 116 #ifdef FAST_IPSEC 117 #include <sys/domain.h> 118 #endif 119 #include <sys/systm.h> 120 #include <sys/proc.h> 121 122 #include <net/if.h> 123 #include <net/route.h> 124 #include <net/pfil.h> 125 126 #include <netinet/in.h> 127 #include <netinet/in_systm.h> 128 #include <netinet/ip.h> 129 #include <netinet/in_pcb.h> 130 #include <netinet/in_var.h> 131 #include <netinet/ip_var.h> 132 #include <netinet/in_offload.h> 133 134 #ifdef MROUTING 135 #include <netinet/ip_mroute.h> 136 #endif 137 138 #include <machine/stdarg.h> 139 140 #ifdef IPSEC 141 #include <netinet6/ipsec.h> 142 #include <netkey/key.h> 143 #include <netkey/key_debug.h> 144 #endif /*IPSEC*/ 145 146 #ifdef FAST_IPSEC 147 #include <netipsec/ipsec.h> 148 #include <netipsec/key.h> 149 #include <netipsec/xform.h> 150 #endif /* FAST_IPSEC*/ 151 152 #ifdef IPSEC_NAT_T 153 #include <netinet/udp.h> 154 #endif 155 156 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 157 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 158 static void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); 159 static int ip_getoptval(struct mbuf *, u_int8_t *, u_int); 160 161 #ifdef PFIL_HOOKS 162 extern struct pfil_head inet_pfil_hook; /* XXX */ 163 #endif 164 165 int ip_do_loopback_cksum = 0; 166 167 #define IN_NEED_CHECKSUM(ifp, csum_flags) \ 168 (__predict_true(((ifp)->if_flags & IFF_LOOPBACK) == 0 || \ 169 (((csum_flags) & M_CSUM_UDPv4) != 0 && udp_do_loopback_cksum) || \ 170 (((csum_flags) & M_CSUM_TCPv4) != 0 && tcp_do_loopback_cksum) || \ 171 (((csum_flags) & M_CSUM_IPv4) != 0 && ip_do_loopback_cksum))) 172 173 struct ip_tso_output_args { 174 struct ifnet *ifp; 175 struct sockaddr *sa; 176 struct rtentry *rt; 177 }; 178 179 static int ip_tso_output_callback(void *, struct mbuf *); 180 static int ip_tso_output(struct ifnet *, struct mbuf *, struct sockaddr *, 181 struct rtentry *); 182 183 static int 184 ip_tso_output_callback(void *vp, struct mbuf *m) 185 { 186 struct ip_tso_output_args *args = vp; 187 struct ifnet *ifp = args->ifp; 188 189 return (*ifp->if_output)(ifp, m, args->sa, args->rt); 190 } 191 192 static int 193 ip_tso_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa, 194 struct rtentry *rt) 195 { 196 struct ip_tso_output_args args; 197 198 args.ifp = ifp; 199 args.sa = sa; 200 args.rt = rt; 201 202 return tcp4_segment(m, ip_tso_output_callback, &args); 203 } 204 205 /* 206 * IP output. The packet in mbuf chain m contains a skeletal IP 207 * header (with len, off, ttl, proto, tos, src, dst). 208 * The mbuf chain containing the packet will be freed. 209 * The mbuf opt, if present, will not be freed. 210 */ 211 int 212 ip_output(struct mbuf *m0, ...) 213 { 214 struct ip *ip; 215 struct ifnet *ifp; 216 struct mbuf *m = m0; 217 int hlen = sizeof (struct ip); 218 int len, error = 0; 219 struct route iproute; 220 struct sockaddr_in *dst; 221 struct in_ifaddr *ia; 222 struct mbuf *opt; 223 struct route *ro; 224 int flags, sw_csum; 225 int *mtu_p; 226 u_long mtu; 227 struct ip_moptions *imo; 228 struct socket *so; 229 va_list ap; 230 #ifdef IPSEC_NAT_T 231 int natt_frag = 0; 232 #endif 233 #ifdef IPSEC 234 struct secpolicy *sp = NULL; 235 #endif /*IPSEC*/ 236 #ifdef FAST_IPSEC 237 struct inpcb *inp; 238 struct m_tag *mtag; 239 struct secpolicy *sp = NULL; 240 struct tdb_ident *tdbi; 241 int s; 242 #endif 243 u_int16_t ip_len; 244 245 len = 0; 246 va_start(ap, m0); 247 opt = va_arg(ap, struct mbuf *); 248 ro = va_arg(ap, struct route *); 249 flags = va_arg(ap, int); 250 imo = va_arg(ap, struct ip_moptions *); 251 so = va_arg(ap, struct socket *); 252 if (flags & IP_RETURNMTU) 253 mtu_p = va_arg(ap, int *); 254 else 255 mtu_p = NULL; 256 va_end(ap); 257 258 MCLAIM(m, &ip_tx_mowner); 259 #ifdef FAST_IPSEC 260 if (so != NULL && so->so_proto->pr_domain->dom_family == AF_INET) 261 inp = (struct inpcb *)so->so_pcb; 262 else 263 inp = NULL; 264 #endif /* FAST_IPSEC */ 265 266 #ifdef DIAGNOSTIC 267 if ((m->m_flags & M_PKTHDR) == 0) 268 panic("ip_output: no HDR"); 269 270 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) != 0) { 271 panic("ip_output: IPv6 checksum offload flags: %d", 272 m->m_pkthdr.csum_flags); 273 } 274 275 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) == 276 (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 277 panic("ip_output: conflicting checksum offload flags: %d", 278 m->m_pkthdr.csum_flags); 279 } 280 #endif 281 if (opt) { 282 m = ip_insertoptions(m, opt, &len); 283 if (len >= sizeof(struct ip)) 284 hlen = len; 285 } 286 ip = mtod(m, struct ip *); 287 /* 288 * Fill in IP header. 289 */ 290 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 291 ip->ip_v = IPVERSION; 292 ip->ip_off = htons(0); 293 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 294 ip->ip_id = ip_newid(); 295 } else { 296 297 /* 298 * TSO capable interfaces (typically?) increment 299 * ip_id for each segment. 300 * "allocate" enough ids here to increase the chance 301 * for them to be unique. 302 * 303 * note that the following calculation is not 304 * needed to be precise. wasting some ip_id is fine. 305 */ 306 307 unsigned int segsz = m->m_pkthdr.segsz; 308 unsigned int datasz = ntohs(ip->ip_len) - hlen; 309 unsigned int num = howmany(datasz, segsz); 310 311 ip->ip_id = ip_newid_range(num); 312 } 313 ip->ip_hl = hlen >> 2; 314 ipstat.ips_localout++; 315 } else { 316 hlen = ip->ip_hl << 2; 317 } 318 /* 319 * Route packet. 320 */ 321 if (ro == 0) { 322 ro = &iproute; 323 bzero((caddr_t)ro, sizeof (*ro)); 324 } 325 dst = satosin(&ro->ro_dst); 326 /* 327 * If there is a cached route, 328 * check that it is to the same destination 329 * and is still up. If not, free it and try again. 330 * The address family should also be checked in case of sharing the 331 * cache with IPv6. 332 */ 333 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 334 dst->sin_family != AF_INET || 335 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 336 RTFREE(ro->ro_rt); 337 ro->ro_rt = (struct rtentry *)0; 338 } 339 if (ro->ro_rt == 0) { 340 bzero(dst, sizeof(*dst)); 341 dst->sin_family = AF_INET; 342 dst->sin_len = sizeof(*dst); 343 dst->sin_addr = ip->ip_dst; 344 } 345 /* 346 * If routing to interface only, 347 * short circuit routing lookup. 348 */ 349 if (flags & IP_ROUTETOIF) { 350 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 351 ipstat.ips_noroute++; 352 error = ENETUNREACH; 353 goto bad; 354 } 355 ifp = ia->ia_ifp; 356 mtu = ifp->if_mtu; 357 ip->ip_ttl = 1; 358 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 359 ip->ip_dst.s_addr == INADDR_BROADCAST) && 360 imo != NULL && imo->imo_multicast_ifp != NULL) { 361 ifp = imo->imo_multicast_ifp; 362 mtu = ifp->if_mtu; 363 IFP_TO_IA(ifp, ia); 364 } else { 365 if (ro->ro_rt == 0) 366 rtalloc(ro); 367 if (ro->ro_rt == 0) { 368 ipstat.ips_noroute++; 369 error = EHOSTUNREACH; 370 goto bad; 371 } 372 ia = ifatoia(ro->ro_rt->rt_ifa); 373 ifp = ro->ro_rt->rt_ifp; 374 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 375 mtu = ifp->if_mtu; 376 ro->ro_rt->rt_use++; 377 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 378 dst = satosin(ro->ro_rt->rt_gateway); 379 } 380 if (IN_MULTICAST(ip->ip_dst.s_addr) || 381 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 382 struct in_multi *inm; 383 384 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 385 M_BCAST : M_MCAST; 386 /* 387 * IP destination address is multicast. Make sure "dst" 388 * still points to the address in "ro". (It may have been 389 * changed to point to a gateway address, above.) 390 */ 391 dst = satosin(&ro->ro_dst); 392 /* 393 * See if the caller provided any multicast options 394 */ 395 if (imo != NULL) 396 ip->ip_ttl = imo->imo_multicast_ttl; 397 else 398 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 399 400 /* 401 * if we don't know the outgoing ifp yet, we can't generate 402 * output 403 */ 404 if (!ifp) { 405 ipstat.ips_noroute++; 406 error = ENETUNREACH; 407 goto bad; 408 } 409 410 /* 411 * If the packet is multicast or broadcast, confirm that 412 * the outgoing interface can transmit it. 413 */ 414 if (((m->m_flags & M_MCAST) && 415 (ifp->if_flags & IFF_MULTICAST) == 0) || 416 ((m->m_flags & M_BCAST) && 417 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 418 ipstat.ips_noroute++; 419 error = ENETUNREACH; 420 goto bad; 421 } 422 /* 423 * If source address not specified yet, use an address 424 * of outgoing interface. 425 */ 426 if (in_nullhost(ip->ip_src)) { 427 struct in_ifaddr *xia; 428 429 IFP_TO_IA(ifp, xia); 430 if (!xia) { 431 error = EADDRNOTAVAIL; 432 goto bad; 433 } 434 ip->ip_src = xia->ia_addr.sin_addr; 435 } 436 437 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 438 if (inm != NULL && 439 (imo == NULL || imo->imo_multicast_loop)) { 440 /* 441 * If we belong to the destination multicast group 442 * on the outgoing interface, and the caller did not 443 * forbid loopback, loop back a copy. 444 */ 445 ip_mloopback(ifp, m, dst); 446 } 447 #ifdef MROUTING 448 else { 449 /* 450 * If we are acting as a multicast router, perform 451 * multicast forwarding as if the packet had just 452 * arrived on the interface to which we are about 453 * to send. The multicast forwarding function 454 * recursively calls this function, using the 455 * IP_FORWARDING flag to prevent infinite recursion. 456 * 457 * Multicasts that are looped back by ip_mloopback(), 458 * above, will be forwarded by the ip_input() routine, 459 * if necessary. 460 */ 461 extern struct socket *ip_mrouter; 462 463 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 464 if (ip_mforward(m, ifp) != 0) { 465 m_freem(m); 466 goto done; 467 } 468 } 469 } 470 #endif 471 /* 472 * Multicasts with a time-to-live of zero may be looped- 473 * back, above, but must not be transmitted on a network. 474 * Also, multicasts addressed to the loopback interface 475 * are not sent -- the above call to ip_mloopback() will 476 * loop back a copy if this host actually belongs to the 477 * destination group on the loopback interface. 478 */ 479 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 480 m_freem(m); 481 goto done; 482 } 483 484 goto sendit; 485 } 486 /* 487 * If source address not specified yet, use address 488 * of outgoing interface. 489 */ 490 if (in_nullhost(ip->ip_src)) 491 ip->ip_src = ia->ia_addr.sin_addr; 492 493 /* 494 * packets with Class-D address as source are not valid per 495 * RFC 1112 496 */ 497 if (IN_MULTICAST(ip->ip_src.s_addr)) { 498 ipstat.ips_odropped++; 499 error = EADDRNOTAVAIL; 500 goto bad; 501 } 502 503 /* 504 * Look for broadcast address and 505 * and verify user is allowed to send 506 * such a packet. 507 */ 508 if (in_broadcast(dst->sin_addr, ifp)) { 509 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 510 error = EADDRNOTAVAIL; 511 goto bad; 512 } 513 if ((flags & IP_ALLOWBROADCAST) == 0) { 514 error = EACCES; 515 goto bad; 516 } 517 /* don't allow broadcast messages to be fragmented */ 518 if (ntohs(ip->ip_len) > ifp->if_mtu) { 519 error = EMSGSIZE; 520 goto bad; 521 } 522 m->m_flags |= M_BCAST; 523 } else 524 m->m_flags &= ~M_BCAST; 525 526 sendit: 527 /* 528 * If we're doing Path MTU Discovery, we need to set DF unless 529 * the route's MTU is locked. 530 */ 531 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 532 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 533 ip->ip_off |= htons(IP_DF); 534 535 /* Remember the current ip_len */ 536 ip_len = ntohs(ip->ip_len); 537 538 #ifdef IPSEC 539 /* get SP for this packet */ 540 if (so == NULL) 541 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 542 flags, &error); 543 else { 544 if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp, 545 IPSEC_DIR_OUTBOUND)) 546 goto skip_ipsec; 547 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 548 } 549 550 if (sp == NULL) { 551 ipsecstat.out_inval++; 552 goto bad; 553 } 554 555 error = 0; 556 557 /* check policy */ 558 switch (sp->policy) { 559 case IPSEC_POLICY_DISCARD: 560 /* 561 * This packet is just discarded. 562 */ 563 ipsecstat.out_polvio++; 564 goto bad; 565 566 case IPSEC_POLICY_BYPASS: 567 case IPSEC_POLICY_NONE: 568 /* no need to do IPsec. */ 569 goto skip_ipsec; 570 571 case IPSEC_POLICY_IPSEC: 572 if (sp->req == NULL) { 573 /* XXX should be panic ? */ 574 printf("ip_output: No IPsec request specified.\n"); 575 error = EINVAL; 576 goto bad; 577 } 578 break; 579 580 case IPSEC_POLICY_ENTRUST: 581 default: 582 printf("ip_output: Invalid policy found. %d\n", sp->policy); 583 } 584 585 #ifdef IPSEC_NAT_T 586 /* 587 * NAT-T ESP fragmentation: don't do IPSec processing now, 588 * we'll do it on each fragmented packet. 589 */ 590 if (sp->req->sav && 591 ((sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP) || 592 (sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP_NON_IKE))) { 593 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 594 natt_frag = 1; 595 mtu = sp->req->sav->esp_frag; 596 goto skip_ipsec; 597 } 598 } 599 #endif /* IPSEC_NAT_T */ 600 601 /* 602 * ipsec4_output() expects ip_len and ip_off in network 603 * order. They have been set to network order above. 604 */ 605 606 { 607 struct ipsec_output_state state; 608 bzero(&state, sizeof(state)); 609 state.m = m; 610 if (flags & IP_ROUTETOIF) { 611 state.ro = &iproute; 612 bzero(&iproute, sizeof(iproute)); 613 } else 614 state.ro = ro; 615 state.dst = (struct sockaddr *)dst; 616 617 /* 618 * We can't defer the checksum of payload data if 619 * we're about to encrypt/authenticate it. 620 * 621 * XXX When we support crypto offloading functions of 622 * XXX network interfaces, we need to reconsider this, 623 * XXX since it's likely that they'll support checksumming, 624 * XXX as well. 625 */ 626 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 627 in_delayed_cksum(m); 628 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 629 } 630 631 error = ipsec4_output(&state, sp, flags); 632 633 m = state.m; 634 if (flags & IP_ROUTETOIF) { 635 /* 636 * if we have tunnel mode SA, we may need to ignore 637 * IP_ROUTETOIF. 638 */ 639 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 640 flags &= ~IP_ROUTETOIF; 641 ro = state.ro; 642 } 643 } else 644 ro = state.ro; 645 dst = (struct sockaddr_in *)state.dst; 646 if (error) { 647 /* mbuf is already reclaimed in ipsec4_output. */ 648 m0 = NULL; 649 switch (error) { 650 case EHOSTUNREACH: 651 case ENETUNREACH: 652 case EMSGSIZE: 653 case ENOBUFS: 654 case ENOMEM: 655 break; 656 default: 657 printf("ip4_output (ipsec): error code %d\n", error); 658 /*fall through*/ 659 case ENOENT: 660 /* don't show these error codes to the user */ 661 error = 0; 662 break; 663 } 664 goto bad; 665 } 666 667 /* be sure to update variables that are affected by ipsec4_output() */ 668 ip = mtod(m, struct ip *); 669 hlen = ip->ip_hl << 2; 670 ip_len = ntohs(ip->ip_len); 671 672 if (ro->ro_rt == NULL) { 673 if ((flags & IP_ROUTETOIF) == 0) { 674 printf("ip_output: " 675 "can't update route after IPsec processing\n"); 676 error = EHOSTUNREACH; /*XXX*/ 677 goto bad; 678 } 679 } else { 680 /* nobody uses ia beyond here */ 681 if (state.encap) { 682 ifp = ro->ro_rt->rt_ifp; 683 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 684 mtu = ifp->if_mtu; 685 } 686 } 687 } 688 skip_ipsec: 689 #endif /*IPSEC*/ 690 #ifdef FAST_IPSEC 691 /* 692 * Check the security policy (SP) for the packet and, if 693 * required, do IPsec-related processing. There are two 694 * cases here; the first time a packet is sent through 695 * it will be untagged and handled by ipsec4_checkpolicy. 696 * If the packet is resubmitted to ip_output (e.g. after 697 * AH, ESP, etc. processing), there will be a tag to bypass 698 * the lookup and related policy checking. 699 */ 700 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 701 s = splsoftnet(); 702 if (mtag != NULL) { 703 tdbi = (struct tdb_ident *)(mtag + 1); 704 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 705 if (sp == NULL) 706 error = -EINVAL; /* force silent drop */ 707 m_tag_delete(m, mtag); 708 } else { 709 if (inp != NULL && 710 IPSEC_PCB_SKIP_IPSEC(inp->inp_sp, IPSEC_DIR_OUTBOUND)) 711 goto spd_done; 712 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 713 &error, inp); 714 } 715 /* 716 * There are four return cases: 717 * sp != NULL apply IPsec policy 718 * sp == NULL, error == 0 no IPsec handling needed 719 * sp == NULL, error == -EINVAL discard packet w/o error 720 * sp == NULL, error != 0 discard packet, report error 721 */ 722 if (sp != NULL) { 723 #ifdef IPSEC_NAT_T 724 /* 725 * NAT-T ESP fragmentation: don't do IPSec processing now, 726 * we'll do it on each fragmented packet. 727 */ 728 if (sp->req->sav && 729 ((sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP) || 730 (sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP_NON_IKE))) { 731 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 732 natt_frag = 1; 733 mtu = sp->req->sav->esp_frag; 734 goto spd_done; 735 } 736 } 737 #endif /* IPSEC_NAT_T */ 738 /* Loop detection, check if ipsec processing already done */ 739 IPSEC_ASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 740 for (mtag = m_tag_first(m); mtag != NULL; 741 mtag = m_tag_next(m, mtag)) { 742 #ifdef MTAG_ABI_COMPAT 743 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 744 continue; 745 #endif 746 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 747 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 748 continue; 749 /* 750 * Check if policy has an SA associated with it. 751 * This can happen when an SP has yet to acquire 752 * an SA; e.g. on first reference. If it occurs, 753 * then we let ipsec4_process_packet do its thing. 754 */ 755 if (sp->req->sav == NULL) 756 break; 757 tdbi = (struct tdb_ident *)(mtag + 1); 758 if (tdbi->spi == sp->req->sav->spi && 759 tdbi->proto == sp->req->sav->sah->saidx.proto && 760 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 761 sizeof (union sockaddr_union)) == 0) { 762 /* 763 * No IPsec processing is needed, free 764 * reference to SP. 765 * 766 * NB: null pointer to avoid free at 767 * done: below. 768 */ 769 KEY_FREESP(&sp), sp = NULL; 770 splx(s); 771 goto spd_done; 772 } 773 } 774 775 /* 776 * Do delayed checksums now because we send before 777 * this is done in the normal processing path. 778 */ 779 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 780 in_delayed_cksum(m); 781 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 782 } 783 784 #ifdef __FreeBSD__ 785 ip->ip_len = htons(ip->ip_len); 786 ip->ip_off = htons(ip->ip_off); 787 #endif 788 789 /* NB: callee frees mbuf */ 790 error = ipsec4_process_packet(m, sp->req, flags, 0); 791 /* 792 * Preserve KAME behaviour: ENOENT can be returned 793 * when an SA acquire is in progress. Don't propagate 794 * this to user-level; it confuses applications. 795 * 796 * XXX this will go away when the SADB is redone. 797 */ 798 if (error == ENOENT) 799 error = 0; 800 splx(s); 801 goto done; 802 } else { 803 splx(s); 804 805 if (error != 0) { 806 /* 807 * Hack: -EINVAL is used to signal that a packet 808 * should be silently discarded. This is typically 809 * because we asked key management for an SA and 810 * it was delayed (e.g. kicked up to IKE). 811 */ 812 if (error == -EINVAL) 813 error = 0; 814 goto bad; 815 } else { 816 /* No IPsec processing for this packet. */ 817 } 818 #ifdef notyet 819 /* 820 * If deferred crypto processing is needed, check that 821 * the interface supports it. 822 */ 823 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 824 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 825 /* notify IPsec to do its own crypto */ 826 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 827 error = EHOSTUNREACH; 828 goto bad; 829 } 830 #endif 831 } 832 spd_done: 833 #endif /* FAST_IPSEC */ 834 835 #ifdef PFIL_HOOKS 836 /* 837 * Run through list of hooks for output packets. 838 */ 839 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) 840 goto done; 841 if (m == NULL) 842 goto done; 843 844 ip = mtod(m, struct ip *); 845 hlen = ip->ip_hl << 2; 846 #endif /* PFIL_HOOKS */ 847 848 m->m_pkthdr.csum_data |= hlen << 16; 849 850 #if IFA_STATS 851 /* 852 * search for the source address structure to 853 * maintain output statistics. 854 */ 855 INADDR_TO_IA(ip->ip_src, ia); 856 #endif 857 858 /* Maybe skip checksums on loopback interfaces. */ 859 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 860 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 861 } 862 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 863 /* 864 * If small enough for mtu of path, or if using TCP segmentation 865 * offload, can just send directly. 866 */ 867 if (ip_len <= mtu || 868 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 869 #if IFA_STATS 870 if (ia) 871 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 872 #endif 873 /* 874 * Always initialize the sum to 0! Some HW assisted 875 * checksumming requires this. 876 */ 877 ip->ip_sum = 0; 878 879 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 880 /* 881 * Perform any checksums that the hardware can't do 882 * for us. 883 * 884 * XXX Does any hardware require the {th,uh}_sum 885 * XXX fields to be 0? 886 */ 887 if (sw_csum & M_CSUM_IPv4) { 888 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 889 ip->ip_sum = in_cksum(m, hlen); 890 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 891 } 892 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 893 if (IN_NEED_CHECKSUM(ifp, 894 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 895 in_delayed_cksum(m); 896 } 897 m->m_pkthdr.csum_flags &= 898 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 899 } 900 } 901 902 #ifdef IPSEC 903 /* clean ipsec history once it goes out of the node */ 904 ipsec_delaux(m); 905 #endif 906 907 if (__predict_true( 908 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 909 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 910 error = 911 (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 912 } else { 913 error = 914 ip_tso_output(ifp, m, sintosa(dst), ro->ro_rt); 915 } 916 goto done; 917 } 918 919 /* 920 * We can't use HW checksumming if we're about to 921 * to fragment the packet. 922 * 923 * XXX Some hardware can do this. 924 */ 925 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 926 if (IN_NEED_CHECKSUM(ifp, 927 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 928 in_delayed_cksum(m); 929 } 930 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 931 } 932 933 /* 934 * Too large for interface; fragment if possible. 935 * Must be able to put at least 8 bytes per fragment. 936 */ 937 if (ntohs(ip->ip_off) & IP_DF) { 938 if (flags & IP_RETURNMTU) 939 *mtu_p = mtu; 940 error = EMSGSIZE; 941 ipstat.ips_cantfrag++; 942 goto bad; 943 } 944 945 error = ip_fragment(m, ifp, mtu); 946 if (error) { 947 m = NULL; 948 goto bad; 949 } 950 951 for (; m; m = m0) { 952 m0 = m->m_nextpkt; 953 m->m_nextpkt = 0; 954 if (error == 0) { 955 #if IFA_STATS 956 if (ia) 957 ia->ia_ifa.ifa_data.ifad_outbytes += 958 ntohs(ip->ip_len); 959 #endif 960 #ifdef IPSEC 961 /* clean ipsec history once it goes out of the node */ 962 ipsec_delaux(m); 963 #endif /* IPSEC */ 964 965 #ifdef IPSEC_NAT_T 966 /* 967 * If we get there, the packet has not been handeld by 968 * IPSec whereas it should have. Now that it has been 969 * fragmented, re-inject it in ip_output so that IPsec 970 * processing can occur. 971 */ 972 if (natt_frag) { 973 error = ip_output(m, opt, 974 ro, flags, imo, so, mtu_p); 975 } else 976 #endif /* IPSEC_NAT_T */ 977 { 978 KASSERT((m->m_pkthdr.csum_flags & 979 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 980 error = (*ifp->if_output)(ifp, m, sintosa(dst), 981 ro->ro_rt); 982 } 983 } else 984 m_freem(m); 985 } 986 987 if (error == 0) 988 ipstat.ips_fragmented++; 989 done: 990 if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) { 991 RTFREE(ro->ro_rt); 992 ro->ro_rt = 0; 993 } 994 995 #ifdef IPSEC 996 if (sp != NULL) { 997 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 998 printf("DP ip_output call free SP:%p\n", sp)); 999 key_freesp(sp); 1000 } 1001 #endif /* IPSEC */ 1002 #ifdef FAST_IPSEC 1003 if (sp != NULL) 1004 KEY_FREESP(&sp); 1005 #endif /* FAST_IPSEC */ 1006 1007 return (error); 1008 bad: 1009 m_freem(m); 1010 goto done; 1011 } 1012 1013 int 1014 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 1015 { 1016 struct ip *ip, *mhip; 1017 struct mbuf *m0; 1018 int len, hlen, off; 1019 int mhlen, firstlen; 1020 struct mbuf **mnext; 1021 int sw_csum = m->m_pkthdr.csum_flags; 1022 int fragments = 0; 1023 int s; 1024 int error = 0; 1025 1026 ip = mtod(m, struct ip *); 1027 hlen = ip->ip_hl << 2; 1028 if (ifp != NULL) 1029 sw_csum &= ~ifp->if_csum_flags_tx; 1030 1031 len = (mtu - hlen) &~ 7; 1032 if (len < 8) { 1033 m_freem(m); 1034 return (EMSGSIZE); 1035 } 1036 1037 firstlen = len; 1038 mnext = &m->m_nextpkt; 1039 1040 /* 1041 * Loop through length of segment after first fragment, 1042 * make new header and copy data of each part and link onto chain. 1043 */ 1044 m0 = m; 1045 mhlen = sizeof (struct ip); 1046 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 1047 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1048 if (m == 0) { 1049 error = ENOBUFS; 1050 ipstat.ips_odropped++; 1051 goto sendorfree; 1052 } 1053 MCLAIM(m, m0->m_owner); 1054 *mnext = m; 1055 mnext = &m->m_nextpkt; 1056 m->m_data += max_linkhdr; 1057 mhip = mtod(m, struct ip *); 1058 *mhip = *ip; 1059 /* we must inherit MCAST and BCAST flags */ 1060 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 1061 if (hlen > sizeof (struct ip)) { 1062 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1063 mhip->ip_hl = mhlen >> 2; 1064 } 1065 m->m_len = mhlen; 1066 mhip->ip_off = ((off - hlen) >> 3) + 1067 (ntohs(ip->ip_off) & ~IP_MF); 1068 if (ip->ip_off & htons(IP_MF)) 1069 mhip->ip_off |= IP_MF; 1070 if (off + len >= ntohs(ip->ip_len)) 1071 len = ntohs(ip->ip_len) - off; 1072 else 1073 mhip->ip_off |= IP_MF; 1074 HTONS(mhip->ip_off); 1075 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 1076 m->m_next = m_copy(m0, off, len); 1077 if (m->m_next == 0) { 1078 error = ENOBUFS; /* ??? */ 1079 ipstat.ips_odropped++; 1080 goto sendorfree; 1081 } 1082 m->m_pkthdr.len = mhlen + len; 1083 m->m_pkthdr.rcvif = (struct ifnet *)0; 1084 mhip->ip_sum = 0; 1085 if (sw_csum & M_CSUM_IPv4) { 1086 mhip->ip_sum = in_cksum(m, mhlen); 1087 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 1088 } else { 1089 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 1090 m->m_pkthdr.csum_data |= mhlen << 16; 1091 } 1092 ipstat.ips_ofragments++; 1093 fragments++; 1094 } 1095 /* 1096 * Update first fragment by trimming what's been copied out 1097 * and updating header, then send each fragment (in order). 1098 */ 1099 m = m0; 1100 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 1101 m->m_pkthdr.len = hlen + firstlen; 1102 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 1103 ip->ip_off |= htons(IP_MF); 1104 ip->ip_sum = 0; 1105 if (sw_csum & M_CSUM_IPv4) { 1106 ip->ip_sum = in_cksum(m, hlen); 1107 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 1108 } else { 1109 KASSERT(m->m_pkthdr.csum_flags & M_CSUM_IPv4); 1110 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 1111 sizeof(struct ip)); 1112 } 1113 sendorfree: 1114 /* 1115 * If there is no room for all the fragments, don't queue 1116 * any of them. 1117 */ 1118 if (ifp != NULL) { 1119 s = splnet(); 1120 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 1121 error == 0) { 1122 error = ENOBUFS; 1123 ipstat.ips_odropped++; 1124 IFQ_INC_DROPS(&ifp->if_snd); 1125 } 1126 splx(s); 1127 } 1128 if (error) { 1129 for (m = m0; m; m = m0) { 1130 m0 = m->m_nextpkt; 1131 m->m_nextpkt = NULL; 1132 m_freem(m); 1133 } 1134 } 1135 return (error); 1136 } 1137 1138 /* 1139 * Process a delayed payload checksum calculation. 1140 */ 1141 void 1142 in_delayed_cksum(struct mbuf *m) 1143 { 1144 struct ip *ip; 1145 u_int16_t csum, offset; 1146 1147 ip = mtod(m, struct ip *); 1148 offset = ip->ip_hl << 2; 1149 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 1150 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 1151 csum = 0xffff; 1152 1153 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 1154 1155 if ((offset + sizeof(u_int16_t)) > m->m_len) { 1156 /* This happen when ip options were inserted 1157 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 1158 m->m_len, offset, ip->ip_p); 1159 */ 1160 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 1161 } else 1162 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1163 } 1164 1165 /* 1166 * Determine the maximum length of the options to be inserted; 1167 * we would far rather allocate too much space rather than too little. 1168 */ 1169 1170 u_int 1171 ip_optlen(struct inpcb *inp) 1172 { 1173 struct mbuf *m = inp->inp_options; 1174 1175 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 1176 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 1177 else 1178 return 0; 1179 } 1180 1181 1182 /* 1183 * Insert IP options into preformed packet. 1184 * Adjust IP destination as required for IP source routing, 1185 * as indicated by a non-zero in_addr at the start of the options. 1186 */ 1187 static struct mbuf * 1188 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1189 { 1190 struct ipoption *p = mtod(opt, struct ipoption *); 1191 struct mbuf *n; 1192 struct ip *ip = mtod(m, struct ip *); 1193 unsigned optlen; 1194 1195 optlen = opt->m_len - sizeof(p->ipopt_dst); 1196 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 1197 return (m); /* XXX should fail */ 1198 if (!in_nullhost(p->ipopt_dst)) 1199 ip->ip_dst = p->ipopt_dst; 1200 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1201 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1202 if (n == 0) 1203 return (m); 1204 MCLAIM(n, m->m_owner); 1205 M_MOVE_PKTHDR(n, m); 1206 m->m_len -= sizeof(struct ip); 1207 m->m_data += sizeof(struct ip); 1208 n->m_next = m; 1209 m = n; 1210 m->m_len = optlen + sizeof(struct ip); 1211 m->m_data += max_linkhdr; 1212 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1213 } else { 1214 m->m_data -= optlen; 1215 m->m_len += optlen; 1216 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 1217 } 1218 m->m_pkthdr.len += optlen; 1219 ip = mtod(m, struct ip *); 1220 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 1221 *phlen = sizeof(struct ip) + optlen; 1222 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1223 return (m); 1224 } 1225 1226 /* 1227 * Copy options from ip to jp, 1228 * omitting those not copied during fragmentation. 1229 */ 1230 int 1231 ip_optcopy(struct ip *ip, struct ip *jp) 1232 { 1233 u_char *cp, *dp; 1234 int opt, optlen, cnt; 1235 1236 cp = (u_char *)(ip + 1); 1237 dp = (u_char *)(jp + 1); 1238 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1239 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1240 opt = cp[0]; 1241 if (opt == IPOPT_EOL) 1242 break; 1243 if (opt == IPOPT_NOP) { 1244 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1245 *dp++ = IPOPT_NOP; 1246 optlen = 1; 1247 continue; 1248 } 1249 #ifdef DIAGNOSTIC 1250 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1251 panic("malformed IPv4 option passed to ip_optcopy"); 1252 #endif 1253 optlen = cp[IPOPT_OLEN]; 1254 #ifdef DIAGNOSTIC 1255 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1256 panic("malformed IPv4 option passed to ip_optcopy"); 1257 #endif 1258 /* bogus lengths should have been caught by ip_dooptions */ 1259 if (optlen > cnt) 1260 optlen = cnt; 1261 if (IPOPT_COPIED(opt)) { 1262 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 1263 dp += optlen; 1264 } 1265 } 1266 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1267 *dp++ = IPOPT_EOL; 1268 return (optlen); 1269 } 1270 1271 /* 1272 * IP socket option processing. 1273 */ 1274 int 1275 ip_ctloutput(int op, struct socket *so, int level, int optname, 1276 struct mbuf **mp) 1277 { 1278 struct inpcb *inp = sotoinpcb(so); 1279 struct mbuf *m = *mp; 1280 int optval = 0; 1281 int error = 0; 1282 #if defined(IPSEC) || defined(FAST_IPSEC) 1283 struct lwp *l = curlwp; /*XXX*/ 1284 #endif 1285 1286 if (level != IPPROTO_IP) { 1287 error = EINVAL; 1288 if (op == PRCO_SETOPT && *mp) 1289 (void) m_free(*mp); 1290 } else switch (op) { 1291 1292 case PRCO_SETOPT: 1293 switch (optname) { 1294 case IP_OPTIONS: 1295 #ifdef notyet 1296 case IP_RETOPTS: 1297 return (ip_pcbopts(optname, &inp->inp_options, m)); 1298 #else 1299 return (ip_pcbopts(&inp->inp_options, m)); 1300 #endif 1301 1302 case IP_TOS: 1303 case IP_TTL: 1304 case IP_RECVOPTS: 1305 case IP_RECVRETOPTS: 1306 case IP_RECVDSTADDR: 1307 case IP_RECVIF: 1308 if (m == NULL || m->m_len != sizeof(int)) 1309 error = EINVAL; 1310 else { 1311 optval = *mtod(m, int *); 1312 switch (optname) { 1313 1314 case IP_TOS: 1315 inp->inp_ip.ip_tos = optval; 1316 break; 1317 1318 case IP_TTL: 1319 inp->inp_ip.ip_ttl = optval; 1320 break; 1321 #define OPTSET(bit) \ 1322 if (optval) \ 1323 inp->inp_flags |= bit; \ 1324 else \ 1325 inp->inp_flags &= ~bit; 1326 1327 case IP_RECVOPTS: 1328 OPTSET(INP_RECVOPTS); 1329 break; 1330 1331 case IP_RECVRETOPTS: 1332 OPTSET(INP_RECVRETOPTS); 1333 break; 1334 1335 case IP_RECVDSTADDR: 1336 OPTSET(INP_RECVDSTADDR); 1337 break; 1338 1339 case IP_RECVIF: 1340 OPTSET(INP_RECVIF); 1341 break; 1342 } 1343 } 1344 break; 1345 #undef OPTSET 1346 1347 case IP_MULTICAST_IF: 1348 case IP_MULTICAST_TTL: 1349 case IP_MULTICAST_LOOP: 1350 case IP_ADD_MEMBERSHIP: 1351 case IP_DROP_MEMBERSHIP: 1352 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1353 break; 1354 1355 case IP_PORTRANGE: 1356 if (m == 0 || m->m_len != sizeof(int)) 1357 error = EINVAL; 1358 else { 1359 optval = *mtod(m, int *); 1360 1361 switch (optval) { 1362 1363 case IP_PORTRANGE_DEFAULT: 1364 case IP_PORTRANGE_HIGH: 1365 inp->inp_flags &= ~(INP_LOWPORT); 1366 break; 1367 1368 case IP_PORTRANGE_LOW: 1369 inp->inp_flags |= INP_LOWPORT; 1370 break; 1371 1372 default: 1373 error = EINVAL; 1374 break; 1375 } 1376 } 1377 break; 1378 1379 #if defined(IPSEC) || defined(FAST_IPSEC) 1380 case IP_IPSEC_POLICY: 1381 { 1382 caddr_t req = NULL; 1383 size_t len = 0; 1384 int priv = 0; 1385 1386 #ifdef __NetBSD__ 1387 if (l == 0 || kauth_authorize_generic(l->l_cred, 1388 KAUTH_GENERIC_ISSUSER, &l->l_acflag)) 1389 priv = 0; 1390 else 1391 priv = 1; 1392 #else 1393 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1394 #endif 1395 if (m) { 1396 req = mtod(m, caddr_t); 1397 len = m->m_len; 1398 } 1399 error = ipsec4_set_policy(inp, optname, req, len, priv); 1400 break; 1401 } 1402 #endif /*IPSEC*/ 1403 1404 default: 1405 error = ENOPROTOOPT; 1406 break; 1407 } 1408 if (m) 1409 (void)m_free(m); 1410 break; 1411 1412 case PRCO_GETOPT: 1413 switch (optname) { 1414 case IP_OPTIONS: 1415 case IP_RETOPTS: 1416 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1417 MCLAIM(m, so->so_mowner); 1418 if (inp->inp_options) { 1419 m->m_len = inp->inp_options->m_len; 1420 bcopy(mtod(inp->inp_options, caddr_t), 1421 mtod(m, caddr_t), (unsigned)m->m_len); 1422 } else 1423 m->m_len = 0; 1424 break; 1425 1426 case IP_TOS: 1427 case IP_TTL: 1428 case IP_RECVOPTS: 1429 case IP_RECVRETOPTS: 1430 case IP_RECVDSTADDR: 1431 case IP_RECVIF: 1432 case IP_ERRORMTU: 1433 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1434 MCLAIM(m, so->so_mowner); 1435 m->m_len = sizeof(int); 1436 switch (optname) { 1437 1438 case IP_TOS: 1439 optval = inp->inp_ip.ip_tos; 1440 break; 1441 1442 case IP_TTL: 1443 optval = inp->inp_ip.ip_ttl; 1444 break; 1445 1446 case IP_ERRORMTU: 1447 optval = inp->inp_errormtu; 1448 break; 1449 1450 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1451 1452 case IP_RECVOPTS: 1453 optval = OPTBIT(INP_RECVOPTS); 1454 break; 1455 1456 case IP_RECVRETOPTS: 1457 optval = OPTBIT(INP_RECVRETOPTS); 1458 break; 1459 1460 case IP_RECVDSTADDR: 1461 optval = OPTBIT(INP_RECVDSTADDR); 1462 break; 1463 1464 case IP_RECVIF: 1465 optval = OPTBIT(INP_RECVIF); 1466 break; 1467 } 1468 *mtod(m, int *) = optval; 1469 break; 1470 1471 #if 0 /* defined(IPSEC) || defined(FAST_IPSEC) */ 1472 /* XXX: code broken */ 1473 case IP_IPSEC_POLICY: 1474 { 1475 caddr_t req = NULL; 1476 size_t len = 0; 1477 1478 if (m) { 1479 req = mtod(m, caddr_t); 1480 len = m->m_len; 1481 } 1482 error = ipsec4_get_policy(inp, req, len, mp); 1483 break; 1484 } 1485 #endif /*IPSEC*/ 1486 1487 case IP_MULTICAST_IF: 1488 case IP_MULTICAST_TTL: 1489 case IP_MULTICAST_LOOP: 1490 case IP_ADD_MEMBERSHIP: 1491 case IP_DROP_MEMBERSHIP: 1492 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1493 if (*mp) 1494 MCLAIM(*mp, so->so_mowner); 1495 break; 1496 1497 case IP_PORTRANGE: 1498 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1499 MCLAIM(m, so->so_mowner); 1500 m->m_len = sizeof(int); 1501 1502 if (inp->inp_flags & INP_LOWPORT) 1503 optval = IP_PORTRANGE_LOW; 1504 else 1505 optval = IP_PORTRANGE_DEFAULT; 1506 1507 *mtod(m, int *) = optval; 1508 break; 1509 1510 default: 1511 error = ENOPROTOOPT; 1512 break; 1513 } 1514 break; 1515 } 1516 return (error); 1517 } 1518 1519 /* 1520 * Set up IP options in pcb for insertion in output packets. 1521 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1522 * with destination address if source routed. 1523 */ 1524 int 1525 #ifdef notyet 1526 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1527 #else 1528 ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) 1529 #endif 1530 { 1531 int cnt, optlen; 1532 u_char *cp; 1533 u_char opt; 1534 1535 /* turn off any old options */ 1536 if (*pcbopt) 1537 (void)m_free(*pcbopt); 1538 *pcbopt = 0; 1539 if (m == (struct mbuf *)0 || m->m_len == 0) { 1540 /* 1541 * Only turning off any previous options. 1542 */ 1543 if (m) 1544 (void)m_free(m); 1545 return (0); 1546 } 1547 1548 #ifndef __vax__ 1549 if (m->m_len % sizeof(int32_t)) 1550 goto bad; 1551 #endif 1552 /* 1553 * IP first-hop destination address will be stored before 1554 * actual options; move other options back 1555 * and clear it when none present. 1556 */ 1557 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1558 goto bad; 1559 cnt = m->m_len; 1560 m->m_len += sizeof(struct in_addr); 1561 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1562 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1563 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1564 1565 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1566 opt = cp[IPOPT_OPTVAL]; 1567 if (opt == IPOPT_EOL) 1568 break; 1569 if (opt == IPOPT_NOP) 1570 optlen = 1; 1571 else { 1572 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1573 goto bad; 1574 optlen = cp[IPOPT_OLEN]; 1575 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1576 goto bad; 1577 } 1578 switch (opt) { 1579 1580 default: 1581 break; 1582 1583 case IPOPT_LSRR: 1584 case IPOPT_SSRR: 1585 /* 1586 * user process specifies route as: 1587 * ->A->B->C->D 1588 * D must be our final destination (but we can't 1589 * check that since we may not have connected yet). 1590 * A is first hop destination, which doesn't appear in 1591 * actual IP option, but is stored before the options. 1592 */ 1593 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1594 goto bad; 1595 m->m_len -= sizeof(struct in_addr); 1596 cnt -= sizeof(struct in_addr); 1597 optlen -= sizeof(struct in_addr); 1598 cp[IPOPT_OLEN] = optlen; 1599 /* 1600 * Move first hop before start of options. 1601 */ 1602 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1603 sizeof(struct in_addr)); 1604 /* 1605 * Then copy rest of options back 1606 * to close up the deleted entry. 1607 */ 1608 (void)memmove(&cp[IPOPT_OFFSET+1], 1609 &cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1610 (unsigned)cnt - (IPOPT_MINOFF - 1)); 1611 break; 1612 } 1613 } 1614 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1615 goto bad; 1616 *pcbopt = m; 1617 return (0); 1618 1619 bad: 1620 (void)m_free(m); 1621 return (EINVAL); 1622 } 1623 1624 /* 1625 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1626 */ 1627 static struct ifnet * 1628 ip_multicast_if(struct in_addr *a, int *ifindexp) 1629 { 1630 int ifindex; 1631 struct ifnet *ifp = NULL; 1632 struct in_ifaddr *ia; 1633 1634 if (ifindexp) 1635 *ifindexp = 0; 1636 if (ntohl(a->s_addr) >> 24 == 0) { 1637 ifindex = ntohl(a->s_addr) & 0xffffff; 1638 if (ifindex < 0 || if_indexlim <= ifindex) 1639 return NULL; 1640 ifp = ifindex2ifnet[ifindex]; 1641 if (!ifp) 1642 return NULL; 1643 if (ifindexp) 1644 *ifindexp = ifindex; 1645 } else { 1646 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1647 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1648 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1649 ifp = ia->ia_ifp; 1650 break; 1651 } 1652 } 1653 } 1654 return ifp; 1655 } 1656 1657 static int 1658 ip_getoptval(struct mbuf *m, u_int8_t *val, u_int maxval) 1659 { 1660 u_int tval; 1661 1662 if (m == NULL) 1663 return EINVAL; 1664 1665 switch (m->m_len) { 1666 case sizeof(u_char): 1667 tval = *(mtod(m, u_char *)); 1668 break; 1669 case sizeof(u_int): 1670 tval = *(mtod(m, u_int *)); 1671 break; 1672 default: 1673 return EINVAL; 1674 } 1675 1676 if (tval > maxval) 1677 return EINVAL; 1678 1679 *val = tval; 1680 return 0; 1681 } 1682 1683 /* 1684 * Set the IP multicast options in response to user setsockopt(). 1685 */ 1686 int 1687 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m) 1688 { 1689 int error = 0; 1690 int i; 1691 struct in_addr addr; 1692 struct ip_mreq *mreq; 1693 struct ifnet *ifp; 1694 struct ip_moptions *imo = *imop; 1695 struct route ro; 1696 struct sockaddr_in *dst; 1697 int ifindex; 1698 1699 if (imo == NULL) { 1700 /* 1701 * No multicast option buffer attached to the pcb; 1702 * allocate one and initialize to default values. 1703 */ 1704 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1705 M_WAITOK); 1706 1707 if (imo == NULL) 1708 return (ENOBUFS); 1709 *imop = imo; 1710 imo->imo_multicast_ifp = NULL; 1711 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1712 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1713 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1714 imo->imo_num_memberships = 0; 1715 } 1716 1717 switch (optname) { 1718 1719 case IP_MULTICAST_IF: 1720 /* 1721 * Select the interface for outgoing multicast packets. 1722 */ 1723 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1724 error = EINVAL; 1725 break; 1726 } 1727 addr = *(mtod(m, struct in_addr *)); 1728 /* 1729 * INADDR_ANY is used to remove a previous selection. 1730 * When no interface is selected, a default one is 1731 * chosen every time a multicast packet is sent. 1732 */ 1733 if (in_nullhost(addr)) { 1734 imo->imo_multicast_ifp = NULL; 1735 break; 1736 } 1737 /* 1738 * The selected interface is identified by its local 1739 * IP address. Find the interface and confirm that 1740 * it supports multicasting. 1741 */ 1742 ifp = ip_multicast_if(&addr, &ifindex); 1743 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1744 error = EADDRNOTAVAIL; 1745 break; 1746 } 1747 imo->imo_multicast_ifp = ifp; 1748 if (ifindex) 1749 imo->imo_multicast_addr = addr; 1750 else 1751 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1752 break; 1753 1754 case IP_MULTICAST_TTL: 1755 /* 1756 * Set the IP time-to-live for outgoing multicast packets. 1757 */ 1758 error = ip_getoptval(m, &imo->imo_multicast_ttl, MAXTTL); 1759 break; 1760 1761 case IP_MULTICAST_LOOP: 1762 /* 1763 * Set the loopback flag for outgoing multicast packets. 1764 * Must be zero or one. 1765 */ 1766 error = ip_getoptval(m, &imo->imo_multicast_loop, 1); 1767 break; 1768 1769 case IP_ADD_MEMBERSHIP: 1770 /* 1771 * Add a multicast group membership. 1772 * Group must be a valid IP multicast address. 1773 */ 1774 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1775 error = EINVAL; 1776 break; 1777 } 1778 mreq = mtod(m, struct ip_mreq *); 1779 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1780 error = EINVAL; 1781 break; 1782 } 1783 /* 1784 * If no interface address was provided, use the interface of 1785 * the route to the given multicast address. 1786 */ 1787 if (in_nullhost(mreq->imr_interface)) { 1788 bzero((caddr_t)&ro, sizeof(ro)); 1789 ro.ro_rt = NULL; 1790 dst = satosin(&ro.ro_dst); 1791 dst->sin_len = sizeof(*dst); 1792 dst->sin_family = AF_INET; 1793 dst->sin_addr = mreq->imr_multiaddr; 1794 rtalloc(&ro); 1795 if (ro.ro_rt == NULL) { 1796 error = EADDRNOTAVAIL; 1797 break; 1798 } 1799 ifp = ro.ro_rt->rt_ifp; 1800 rtfree(ro.ro_rt); 1801 } else { 1802 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1803 } 1804 /* 1805 * See if we found an interface, and confirm that it 1806 * supports multicast. 1807 */ 1808 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1809 error = EADDRNOTAVAIL; 1810 break; 1811 } 1812 /* 1813 * See if the membership already exists or if all the 1814 * membership slots are full. 1815 */ 1816 for (i = 0; i < imo->imo_num_memberships; ++i) { 1817 if (imo->imo_membership[i]->inm_ifp == ifp && 1818 in_hosteq(imo->imo_membership[i]->inm_addr, 1819 mreq->imr_multiaddr)) 1820 break; 1821 } 1822 if (i < imo->imo_num_memberships) { 1823 error = EADDRINUSE; 1824 break; 1825 } 1826 if (i == IP_MAX_MEMBERSHIPS) { 1827 error = ETOOMANYREFS; 1828 break; 1829 } 1830 /* 1831 * Everything looks good; add a new record to the multicast 1832 * address list for the given interface. 1833 */ 1834 if ((imo->imo_membership[i] = 1835 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1836 error = ENOBUFS; 1837 break; 1838 } 1839 ++imo->imo_num_memberships; 1840 break; 1841 1842 case IP_DROP_MEMBERSHIP: 1843 /* 1844 * Drop a multicast group membership. 1845 * Group must be a valid IP multicast address. 1846 */ 1847 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1848 error = EINVAL; 1849 break; 1850 } 1851 mreq = mtod(m, struct ip_mreq *); 1852 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1853 error = EINVAL; 1854 break; 1855 } 1856 /* 1857 * If an interface address was specified, get a pointer 1858 * to its ifnet structure. 1859 */ 1860 if (in_nullhost(mreq->imr_interface)) 1861 ifp = NULL; 1862 else { 1863 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1864 if (ifp == NULL) { 1865 error = EADDRNOTAVAIL; 1866 break; 1867 } 1868 } 1869 /* 1870 * Find the membership in the membership array. 1871 */ 1872 for (i = 0; i < imo->imo_num_memberships; ++i) { 1873 if ((ifp == NULL || 1874 imo->imo_membership[i]->inm_ifp == ifp) && 1875 in_hosteq(imo->imo_membership[i]->inm_addr, 1876 mreq->imr_multiaddr)) 1877 break; 1878 } 1879 if (i == imo->imo_num_memberships) { 1880 error = EADDRNOTAVAIL; 1881 break; 1882 } 1883 /* 1884 * Give up the multicast address record to which the 1885 * membership points. 1886 */ 1887 in_delmulti(imo->imo_membership[i]); 1888 /* 1889 * Remove the gap in the membership array. 1890 */ 1891 for (++i; i < imo->imo_num_memberships; ++i) 1892 imo->imo_membership[i-1] = imo->imo_membership[i]; 1893 --imo->imo_num_memberships; 1894 break; 1895 1896 default: 1897 error = EOPNOTSUPP; 1898 break; 1899 } 1900 1901 /* 1902 * If all options have default values, no need to keep the mbuf. 1903 */ 1904 if (imo->imo_multicast_ifp == NULL && 1905 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1906 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1907 imo->imo_num_memberships == 0) { 1908 free(*imop, M_IPMOPTS); 1909 *imop = NULL; 1910 } 1911 1912 return (error); 1913 } 1914 1915 /* 1916 * Return the IP multicast options in response to user getsockopt(). 1917 */ 1918 int 1919 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf **mp) 1920 { 1921 u_char *ttl; 1922 u_char *loop; 1923 struct in_addr *addr; 1924 struct in_ifaddr *ia; 1925 1926 *mp = m_get(M_WAIT, MT_SOOPTS); 1927 1928 switch (optname) { 1929 1930 case IP_MULTICAST_IF: 1931 addr = mtod(*mp, struct in_addr *); 1932 (*mp)->m_len = sizeof(struct in_addr); 1933 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1934 *addr = zeroin_addr; 1935 else if (imo->imo_multicast_addr.s_addr) { 1936 /* return the value user has set */ 1937 *addr = imo->imo_multicast_addr; 1938 } else { 1939 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1940 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1941 } 1942 return (0); 1943 1944 case IP_MULTICAST_TTL: 1945 ttl = mtod(*mp, u_char *); 1946 (*mp)->m_len = 1; 1947 *ttl = imo ? imo->imo_multicast_ttl 1948 : IP_DEFAULT_MULTICAST_TTL; 1949 return (0); 1950 1951 case IP_MULTICAST_LOOP: 1952 loop = mtod(*mp, u_char *); 1953 (*mp)->m_len = 1; 1954 *loop = imo ? imo->imo_multicast_loop 1955 : IP_DEFAULT_MULTICAST_LOOP; 1956 return (0); 1957 1958 default: 1959 return (EOPNOTSUPP); 1960 } 1961 } 1962 1963 /* 1964 * Discard the IP multicast options. 1965 */ 1966 void 1967 ip_freemoptions(struct ip_moptions *imo) 1968 { 1969 int i; 1970 1971 if (imo != NULL) { 1972 for (i = 0; i < imo->imo_num_memberships; ++i) 1973 in_delmulti(imo->imo_membership[i]); 1974 free(imo, M_IPMOPTS); 1975 } 1976 } 1977 1978 /* 1979 * Routine called from ip_output() to loop back a copy of an IP multicast 1980 * packet to the input queue of a specified interface. Note that this 1981 * calls the output routine of the loopback "driver", but with an interface 1982 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1983 */ 1984 static void 1985 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1986 { 1987 struct ip *ip; 1988 struct mbuf *copym; 1989 1990 copym = m_copy(m, 0, M_COPYALL); 1991 if (copym != NULL 1992 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1993 copym = m_pullup(copym, sizeof(struct ip)); 1994 if (copym != NULL) { 1995 /* 1996 * We don't bother to fragment if the IP length is greater 1997 * than the interface's MTU. Can this possibly matter? 1998 */ 1999 ip = mtod(copym, struct ip *); 2000 2001 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 2002 in_delayed_cksum(copym); 2003 copym->m_pkthdr.csum_flags &= 2004 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 2005 } 2006 2007 ip->ip_sum = 0; 2008 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 2009 (void) looutput(ifp, copym, sintosa(dst), NULL); 2010 } 2011 } 2012