1 /* $OpenBSD: in6_src.c,v 1.51 2015/06/08 22:19:28 krw Exp $ */ 2 /* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1991, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/mbuf.h> 67 #include <sys/protosw.h> 68 #include <sys/socket.h> 69 #include <sys/socketvar.h> 70 #include <sys/ioctl.h> 71 #include <sys/errno.h> 72 #include <sys/time.h> 73 74 #include <net/if.h> 75 #include <net/if_var.h> 76 #include <net/route.h> 77 78 #include <netinet/in.h> 79 #include <netinet/ip.h> 80 #include <netinet/in_pcb.h> 81 #include <netinet6/in6_var.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/ip6_var.h> 84 #include <netinet6/nd6.h> 85 86 int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 87 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 88 int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 89 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 90 struct rtentry **, int, u_int); 91 92 /* 93 * Return an IPv6 address, which is the most appropriate for a given 94 * destination and user specified options. 95 * If necessary, this function lookups the routing table and returns 96 * an entry to the caller for later use. 97 */ 98 int 99 in6_selectsrc(struct in6_addr **in6src, struct sockaddr_in6 *dstsock, 100 struct ip6_pktopts *opts, struct ip6_moptions *mopts, 101 struct route_in6 *ro, struct in6_addr *laddr, u_int rtableid) 102 { 103 struct ifnet *ifp = NULL; 104 struct in6_addr *dst; 105 struct in6_ifaddr *ia6 = NULL; 106 struct in6_pktinfo *pi = NULL; 107 int error; 108 109 dst = &dstsock->sin6_addr; 110 111 /* 112 * If the source address is explicitly specified by the caller, 113 * check if the requested source address is indeed a unicast address 114 * assigned to the node, and can be used as the packet's source 115 * address. If everything is okay, use the address as source. 116 */ 117 if (opts && (pi = opts->ip6po_pktinfo) && 118 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 119 struct sockaddr_in6 sa6; 120 121 /* get the outgoing interface */ 122 error = in6_selectif(dstsock, opts, mopts, ro, &ifp, rtableid); 123 if (error) 124 return (error); 125 126 bzero(&sa6, sizeof(sa6)); 127 sa6.sin6_family = AF_INET6; 128 sa6.sin6_len = sizeof(sa6); 129 sa6.sin6_addr = pi->ipi6_addr; 130 131 if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr)) 132 sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 133 134 ia6 = ifatoia6(ifa_ifwithaddr(sin6tosa(&sa6), rtableid)); 135 if (ia6 == NULL || 136 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) 137 return (EADDRNOTAVAIL); 138 139 pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */ 140 141 *in6src = &pi->ipi6_addr; 142 return (0); 143 } 144 145 /* 146 * If the source address is not specified but the socket(if any) 147 * is already bound, use the bound address. 148 */ 149 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { 150 *in6src = laddr; 151 return (0); 152 } 153 154 /* 155 * If the caller doesn't specify the source address but 156 * the outgoing interface, use an address associated with 157 * the interface. 158 */ 159 if (pi && pi->ipi6_ifindex) { 160 ifp = if_get(pi->ipi6_ifindex); 161 if (ifp == NULL) 162 return (ENXIO); /* XXX: better error? */ 163 164 ia6 = in6_ifawithscope(ifp, dst, rtableid); 165 if (ia6 == NULL) 166 return (EADDRNOTAVAIL); 167 168 *in6src = &ia6->ia_addr.sin6_addr; 169 return (0); 170 } 171 172 /* 173 * If the destination address is a link-local unicast address or 174 * a link/interface-local multicast address, and if the outgoing 175 * interface is specified by the sin6_scope_id filed, use an address 176 * associated with the interface. 177 * XXX: We're now trying to define more specific semantics of 178 * sin6_scope_id field, so this part will be rewritten in 179 * the near future. 180 */ 181 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) || 182 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) { 183 ifp = if_get(dstsock->sin6_scope_id); 184 if (ifp == NULL) 185 return (ENXIO); /* XXX: better error? */ 186 187 ia6 = in6_ifawithscope(ifp, dst, rtableid); 188 if (ia6 == NULL) 189 return (EADDRNOTAVAIL); 190 191 *in6src = &ia6->ia_addr.sin6_addr; 192 return (0); 193 } 194 195 /* 196 * If the destination address is a multicast address and 197 * the outgoing interface for the address is specified 198 * by the caller, use an address associated with the interface. 199 * Even if the outgoing interface is not specified, we also 200 * choose a loopback interface as the outgoing interface. 201 */ 202 if (IN6_IS_ADDR_MULTICAST(dst)) { 203 ifp = mopts ? if_get(mopts->im6o_ifidx) : NULL; 204 205 if (!ifp && dstsock->sin6_scope_id) 206 ifp = if_get(htons(dstsock->sin6_scope_id)); 207 208 if (ifp) { 209 ia6 = in6_ifawithscope(ifp, dst, rtableid); 210 if (ia6 == NULL) 211 return (EADDRNOTAVAIL); 212 213 *in6src = &ia6->ia_addr.sin6_addr; 214 return (0); 215 } 216 } 217 218 /* 219 * If the next hop address for the packet is specified 220 * by caller, use an address associated with the route 221 * to the next hop. 222 */ 223 { 224 struct sockaddr_in6 *sin6_next; 225 struct rtentry *rt; 226 227 if (opts && opts->ip6po_nexthop) { 228 sin6_next = satosin6(opts->ip6po_nexthop); 229 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL, 230 rtableid); 231 if (rt) { 232 ia6 = in6_ifawithscope(rt->rt_ifp, dst, 233 rtableid); 234 if (ia6 == NULL) 235 ia6 = ifatoia6(rt->rt_ifa); 236 } 237 if (ia6 == NULL) 238 return (EADDRNOTAVAIL); 239 240 *in6src = &ia6->ia_addr.sin6_addr; 241 return (0); 242 } 243 } 244 245 /* 246 * If route is known or can be allocated now, 247 * our src addr is taken from the i/f, else punt. 248 */ 249 if (ro) { 250 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 251 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 252 rtfree(ro->ro_rt); 253 ro->ro_rt = NULL; 254 } 255 if (ro->ro_rt == (struct rtentry *)0 || 256 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 257 struct sockaddr_in6 *sa6; 258 259 /* No route yet, so try to acquire one */ 260 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 261 ro->ro_tableid = rtableid; 262 sa6 = &ro->ro_dst; 263 sa6->sin6_family = AF_INET6; 264 sa6->sin6_len = sizeof(struct sockaddr_in6); 265 sa6->sin6_addr = *dst; 266 sa6->sin6_scope_id = dstsock->sin6_scope_id; 267 if (IN6_IS_ADDR_MULTICAST(dst)) { 268 ro->ro_rt = rtalloc(sin6tosa(&ro->ro_dst), 269 RT_REPORT|RT_RESOLVE, ro->ro_tableid); 270 } else { 271 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 272 NULL, ro->ro_tableid); 273 } 274 } 275 276 /* 277 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 278 * the address. But we don't know why it does so. 279 * It is necessary to ensure the scope even for lo0 280 * so doesn't check out IFF_LOOPBACK. 281 */ 282 283 if (ro->ro_rt) { 284 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, 285 rtableid); 286 if (ia6 == NULL) /* xxx scope error ?*/ 287 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 288 } 289 if (ia6 == NULL) 290 return (EHOSTUNREACH); /* no route */ 291 292 *in6src = &ia6->ia_addr.sin6_addr; 293 return (0); 294 } 295 296 return (EADDRNOTAVAIL); 297 } 298 299 int 300 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 301 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 302 struct rtentry **retrt, int norouteok, u_int rtableid) 303 { 304 int error = 0; 305 struct ifnet *ifp = NULL; 306 struct rtentry *rt = NULL; 307 struct sockaddr_in6 *sin6_next; 308 struct in6_pktinfo *pi = NULL; 309 struct in6_addr *dst; 310 311 dst = &dstsock->sin6_addr; 312 313 #if 0 314 char ip[INET6_ADDRSTRLEN]; 315 316 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 317 dstsock->sin6_addr.s6_addr32[1] == 0 && 318 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 319 printf("in6_selectroute: strange destination %s\n", 320 inet_ntop(AF_INET6, &dstsock->sin6_addr, ip, sizeof(ip))); 321 } else { 322 printf("in6_selectroute: destination = %s%%%d\n", 323 inet_ntop(AF_INET6, &dstsock->sin6_addr, ip, sizeof(ip)), 324 dstsock->sin6_scope_id); /* for debug */ 325 } 326 #endif 327 328 /* If the caller specify the outgoing interface explicitly, use it. */ 329 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 330 ifp = if_get(pi->ipi6_ifindex); 331 if (ifp != NULL && 332 (norouteok || retrt == NULL || 333 IN6_IS_ADDR_MULTICAST(dst))) { 334 /* 335 * we do not have to check or get the route for 336 * multicast. 337 */ 338 goto done; 339 } else 340 goto getroute; 341 } 342 343 /* 344 * If the destination address is a multicast address and the outgoing 345 * interface for the address is specified by the caller, use it. 346 */ 347 if (IN6_IS_ADDR_MULTICAST(dst) && 348 mopts != NULL && (ifp = if_get(mopts->im6o_ifidx)) != NULL) { 349 goto done; /* we do not need a route for multicast. */ 350 } 351 352 getroute: 353 /* 354 * If the next hop address for the packet is specified by the caller, 355 * use it as the gateway. 356 */ 357 if (opts && opts->ip6po_nexthop) { 358 struct route_in6 *ron; 359 360 sin6_next = satosin6(opts->ip6po_nexthop); 361 362 /* at this moment, we only support AF_INET6 next hops */ 363 if (sin6_next->sin6_family != AF_INET6) { 364 error = EAFNOSUPPORT; /* or should we proceed? */ 365 goto done; 366 } 367 368 /* 369 * If the next hop is an IPv6 address, then the node identified 370 * by that address must be a neighbor of the sending host. 371 */ 372 ron = &opts->ip6po_nextroute; 373 if ((ron->ro_rt && 374 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 375 RTF_UP) || 376 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 377 &sin6_next->sin6_addr)) { 378 if (ron->ro_rt) { 379 rtfree(ron->ro_rt); 380 ron->ro_rt = NULL; 381 } 382 ron->ro_dst = *sin6_next; 383 ron->ro_tableid = rtableid; 384 } 385 if (ron->ro_rt == NULL) { 386 /* multi path case? */ 387 ron->ro_rt = rtalloc(sin6tosa(&ron->ro_dst), 388 RT_REPORT|RT_RESOLVE, ron->ro_tableid); 389 if (ron->ro_rt == NULL || 390 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 391 if (ron->ro_rt) { 392 rtfree(ron->ro_rt); 393 ron->ro_rt = NULL; 394 } 395 error = EHOSTUNREACH; 396 goto done; 397 } 398 } 399 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 400 rtfree(ron->ro_rt); 401 ron->ro_rt = NULL; 402 error = EHOSTUNREACH; 403 goto done; 404 } 405 rt = ron->ro_rt; 406 ifp = rt->rt_ifp; 407 408 /* 409 * When cloning is required, try to allocate a route to the 410 * destination so that the caller can store path MTU 411 * information. 412 */ 413 goto done; 414 } 415 416 /* 417 * Use a cached route if it exists and is valid, else try to allocate 418 * a new one. Note that we should check the address family of the 419 * cached destination, in case of sharing the cache with IPv4. 420 */ 421 if (ro) { 422 if (ro->ro_rt && 423 (!(ro->ro_rt->rt_flags & RTF_UP) || 424 sin6tosa(&ro->ro_dst)->sa_family != AF_INET6 || 425 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 426 rtfree(ro->ro_rt); 427 ro->ro_rt = NULL; 428 } 429 if (ro->ro_rt == NULL) { 430 struct sockaddr_in6 *sa6; 431 432 /* No route yet, so try to acquire one */ 433 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 434 ro->ro_tableid = rtableid; 435 sa6 = &ro->ro_dst; 436 *sa6 = *dstsock; 437 sa6->sin6_scope_id = 0; 438 ro->ro_tableid = rtableid; 439 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 440 NULL, ro->ro_tableid); 441 } 442 443 /* 444 * do not care about the result if we have the nexthop 445 * explicitly specified. 446 */ 447 if (opts && opts->ip6po_nexthop) 448 goto done; 449 450 if (ro->ro_rt) { 451 ifp = ro->ro_rt->rt_ifp; 452 453 if (ifp == NULL) { /* can this really happen? */ 454 rtfree(ro->ro_rt); 455 ro->ro_rt = NULL; 456 } 457 } 458 if (ro->ro_rt == NULL) 459 error = EHOSTUNREACH; 460 rt = ro->ro_rt; 461 462 /* 463 * Check if the outgoing interface conflicts with 464 * the interface specified by ipi6_ifindex (if specified). 465 * Note that loopback interface is always okay. 466 * (this may happen when we are sending a packet to one of 467 * our own addresses.) 468 */ 469 if (opts && opts->ip6po_pktinfo && 470 opts->ip6po_pktinfo->ipi6_ifindex) { 471 if (!(ifp->if_flags & IFF_LOOPBACK) && 472 ifp->if_index != 473 opts->ip6po_pktinfo->ipi6_ifindex) { 474 error = EHOSTUNREACH; 475 goto done; 476 } 477 } 478 } 479 480 done: 481 if (ifp == NULL && rt == NULL) { 482 /* 483 * This can happen if the caller did not pass a cached route 484 * nor any other hints. We treat this case an error. 485 */ 486 error = EHOSTUNREACH; 487 } 488 if (error == EHOSTUNREACH) 489 ip6stat.ip6s_noroute++; 490 491 if (retifp != NULL) 492 *retifp = ifp; 493 if (retrt != NULL) 494 *retrt = rt; /* rt may be NULL */ 495 496 return (error); 497 } 498 499 int 500 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 501 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 502 u_int rtableid) 503 { 504 struct rtentry *rt = NULL; 505 int error; 506 507 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 508 &rt, 1, rtableid)) != 0) 509 return (error); 510 511 /* 512 * do not use a rejected or black hole route. 513 * XXX: this check should be done in the L2 output routine. 514 * However, if we skipped this check here, we'd see the following 515 * scenario: 516 * - install a rejected route for a scoped address prefix 517 * (like fe80::/10) 518 * - send a packet to a destination that matches the scoped prefix, 519 * with ambiguity about the scope zone. 520 * - pick the outgoing interface from the route, and disambiguate the 521 * scope zone with the interface. 522 * - ip6_output() would try to get another route with the "new" 523 * destination, which may be valid. 524 * - we'd see no error on output. 525 * Although this may not be very harmful, it should still be confusing. 526 * We thus reject the case here. 527 */ 528 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 529 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 530 531 /* 532 * Adjust the "outgoing" interface. If we're going to loop the packet 533 * back to ourselves, the ifp would be the loopback interface. 534 * However, we'd rather know the interface associated to the 535 * destination address (which should probably be one of our own 536 * addresses.) 537 */ 538 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 539 *retifp = rt->rt_ifa->ifa_ifp; 540 541 return (0); 542 } 543 544 int 545 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 546 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 547 struct rtentry **retrt, u_int rtableid) 548 { 549 550 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 551 rtableid)); 552 } 553 554 /* 555 * Default hop limit selection. The precedence is as follows: 556 * 1. Hoplimit value specified via ioctl. 557 * 2. (If the outgoing interface is detected) the current 558 * hop limit of the interface specified by router advertisement. 559 * 3. The system default hoplimit. 560 */ 561 int 562 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 563 { 564 if (in6p && in6p->inp_hops >= 0) 565 return (in6p->inp_hops); 566 else if (ifp) 567 return (ND_IFINFO(ifp)->chlim); 568 else 569 return (ip6_defhlim); 570 } 571 572 /* 573 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 574 * If the address scope of is link-local, embed the interface index in the 575 * address. The routine determines our precedence 576 * between advanced API scope/interface specification and basic API 577 * specification. 578 * 579 * this function should be nuked in the future, when we get rid of 580 * embedded scopeid thing. 581 * 582 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 583 * there can be multiple interfaces that belong to a particular scope zone 584 * (in specification, we have 1:N mapping between a scope zone and interfaces). 585 * we may want to change the function to return something other than ifp. 586 */ 587 int 588 in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, 589 struct inpcb *in6p, struct ifnet **ifpp) 590 { 591 struct ifnet *ifp = NULL; 592 u_int32_t scopeid; 593 594 *in6 = sin6->sin6_addr; 595 scopeid = sin6->sin6_scope_id; 596 if (ifpp) 597 *ifpp = NULL; 598 599 /* 600 * don't try to read sin6->sin6_addr beyond here, since the caller may 601 * ask us to overwrite existing sockaddr_in6 602 */ 603 604 if (IN6_IS_SCOPE_EMBED(in6)) { 605 struct in6_pktinfo *pi; 606 607 /* 608 * KAME assumption: link id == interface id 609 */ 610 611 if (in6p && in6p->inp_outputopts6 && 612 (pi = in6p->inp_outputopts6->ip6po_pktinfo) && 613 pi->ipi6_ifindex) { 614 ifp = if_get(pi->ipi6_ifindex); 615 if (ifp == NULL) 616 return ENXIO; /* XXX EINVAL? */ 617 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 618 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 619 in6p->inp_moptions6 && 620 (ifp = if_get(in6p->inp_moptions6->im6o_ifidx))) { 621 in6->s6_addr16[1] = htons(ifp->if_index); 622 } else if (scopeid) { 623 ifp = if_get(scopeid); 624 if (ifp == NULL) 625 return ENXIO; /* XXX EINVAL? */ 626 /*XXX assignment to 16bit from 32bit variable */ 627 in6->s6_addr16[1] = htons(scopeid & 0xffff); 628 } 629 630 if (ifpp) 631 *ifpp = ifp; 632 } 633 634 return 0; 635 } 636 637 /* 638 * generate standard sockaddr_in6 from embedded form. 639 * touches sin6_addr and sin6_scope_id only. 640 * 641 * this function should be nuked in the future, when we get rid of 642 * embedded scopeid thing. 643 */ 644 int 645 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 646 struct ifnet *ifp) 647 { 648 u_int32_t scopeid; 649 650 sin6->sin6_addr = *in6; 651 652 /* 653 * don't try to read *in6 beyond here, since the caller may 654 * ask us to overwrite existing sockaddr_in6 655 */ 656 657 sin6->sin6_scope_id = 0; 658 if (IN6_IS_SCOPE_EMBED(in6)) { 659 /* 660 * KAME assumption: link id == interface id 661 */ 662 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 663 if (scopeid) { 664 /* sanity check */ 665 if (if_get(scopeid) == NULL) 666 return ENXIO; 667 if (ifp && ifp->if_index != scopeid) 668 return ENXIO; 669 sin6->sin6_addr.s6_addr16[1] = 0; 670 sin6->sin6_scope_id = scopeid; 671 } 672 } 673 674 return 0; 675 } 676 677 /* 678 * just clear the embedded scope identifer. 679 */ 680 void 681 in6_clearscope(struct in6_addr *addr) 682 { 683 if (IN6_IS_SCOPE_EMBED(addr)) 684 addr->s6_addr16[1] = 0; 685 } 686