in6_src.c revision 1.54
1/* $OpenBSD: in6_src.c,v 1.54 2015/09/03 09:59:59 mpi 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 86int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 87 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 88int 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 */ 98int 99in6_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 (!rtisvalid(ro->ro_rt) || 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 == NULL) { 256 struct sockaddr_in6 *sa6; 257 258 /* No route yet, so try to acquire one */ 259 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 260 ro->ro_tableid = rtableid; 261 sa6 = &ro->ro_dst; 262 sa6->sin6_family = AF_INET6; 263 sa6->sin6_len = sizeof(struct sockaddr_in6); 264 sa6->sin6_addr = *dst; 265 sa6->sin6_scope_id = dstsock->sin6_scope_id; 266 if (IN6_IS_ADDR_MULTICAST(dst)) { 267 ro->ro_rt = rtalloc(sin6tosa(&ro->ro_dst), 268 RT_REPORT|RT_RESOLVE, ro->ro_tableid); 269 } else { 270 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 271 NULL, ro->ro_tableid); 272 } 273 } 274 275 /* 276 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 277 * the address. But we don't know why it does so. 278 * It is necessary to ensure the scope even for lo0 279 * so doesn't check out IFF_LOOPBACK. 280 */ 281 282 if (ro->ro_rt) { 283 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, 284 rtableid); 285 if (ia6 == NULL) /* xxx scope error ?*/ 286 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 287 } 288 if (ia6 == NULL) 289 return (EHOSTUNREACH); /* no route */ 290 291 *in6src = &ia6->ia_addr.sin6_addr; 292 return (0); 293 } 294 295 return (EADDRNOTAVAIL); 296} 297 298int 299selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 300 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 301 struct rtentry **retrt, int norouteok, u_int rtableid) 302{ 303 int error = 0; 304 struct ifnet *ifp = NULL; 305 struct rtentry *rt = NULL; 306 struct sockaddr_in6 *sin6_next; 307 struct in6_pktinfo *pi = NULL; 308 struct in6_addr *dst; 309 310 dst = &dstsock->sin6_addr; 311 312#if 0 313 char ip[INET6_ADDRSTRLEN]; 314 315 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 316 dstsock->sin6_addr.s6_addr32[1] == 0 && 317 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 318 printf("in6_selectroute: strange destination %s\n", 319 inet_ntop(AF_INET6, &dstsock->sin6_addr, ip, sizeof(ip))); 320 } else { 321 printf("in6_selectroute: destination = %s%%%d\n", 322 inet_ntop(AF_INET6, &dstsock->sin6_addr, ip, sizeof(ip)), 323 dstsock->sin6_scope_id); /* for debug */ 324 } 325#endif 326 327 /* If the caller specify the outgoing interface explicitly, use it. */ 328 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 329 ifp = if_get(pi->ipi6_ifindex); 330 if (ifp != NULL && 331 (norouteok || retrt == NULL || 332 IN6_IS_ADDR_MULTICAST(dst))) { 333 /* 334 * we do not have to check or get the route for 335 * multicast. 336 */ 337 goto done; 338 } else 339 goto getroute; 340 } 341 342 /* 343 * If the destination address is a multicast address and the outgoing 344 * interface for the address is specified by the caller, use it. 345 */ 346 if (IN6_IS_ADDR_MULTICAST(dst) && 347 mopts != NULL && (ifp = if_get(mopts->im6o_ifidx)) != NULL) { 348 goto done; /* we do not need a route for multicast. */ 349 } 350 351 getroute: 352 /* 353 * If the next hop address for the packet is specified by the caller, 354 * use it as the gateway. 355 */ 356 if (opts && opts->ip6po_nexthop) { 357 struct route_in6 *ron; 358 359 sin6_next = satosin6(opts->ip6po_nexthop); 360 361 /* at this moment, we only support AF_INET6 next hops */ 362 if (sin6_next->sin6_family != AF_INET6) { 363 error = EAFNOSUPPORT; /* or should we proceed? */ 364 goto done; 365 } 366 367 /* 368 * If the next hop is an IPv6 address, then the node identified 369 * by that address must be a neighbor of the sending host. 370 */ 371 ron = &opts->ip6po_nextroute; 372 if ((ron->ro_rt && 373 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 374 RTF_UP) || 375 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 376 &sin6_next->sin6_addr)) { 377 if (ron->ro_rt) { 378 rtfree(ron->ro_rt); 379 ron->ro_rt = NULL; 380 } 381 ron->ro_dst = *sin6_next; 382 ron->ro_tableid = rtableid; 383 } 384 if (ron->ro_rt == NULL) { 385 /* multi path case? */ 386 ron->ro_rt = rtalloc(sin6tosa(&ron->ro_dst), 387 RT_REPORT|RT_RESOLVE, ron->ro_tableid); 388 if (ron->ro_rt == NULL || 389 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 390 if (ron->ro_rt) { 391 rtfree(ron->ro_rt); 392 ron->ro_rt = NULL; 393 } 394 error = EHOSTUNREACH; 395 goto done; 396 } 397 } 398 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 399 rtfree(ron->ro_rt); 400 ron->ro_rt = NULL; 401 error = EHOSTUNREACH; 402 goto done; 403 } 404 rt = ron->ro_rt; 405 ifp = rt->rt_ifp; 406 407 /* 408 * When cloning is required, try to allocate a route to the 409 * destination so that the caller can store path MTU 410 * information. 411 */ 412 goto done; 413 } 414 415 /* 416 * Use a cached route if it exists and is valid, else try to allocate 417 * a new one. Note that we should check the address family of the 418 * cached destination, in case of sharing the cache with IPv4. 419 */ 420 if (ro) { 421 if (!rtisvalid(ro->ro_rt) || 422 sin6tosa(&ro->ro_dst)->sa_family != AF_INET6 || 423 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst)) { 424 rtfree(ro->ro_rt); 425 ro->ro_rt = NULL; 426 } 427 if (ro->ro_rt == NULL) { 428 struct sockaddr_in6 *sa6; 429 430 /* No route yet, so try to acquire one */ 431 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 432 ro->ro_tableid = rtableid; 433 sa6 = &ro->ro_dst; 434 *sa6 = *dstsock; 435 sa6->sin6_scope_id = 0; 436 ro->ro_tableid = rtableid; 437 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 438 NULL, ro->ro_tableid); 439 } 440 441 /* 442 * do not care about the result if we have the nexthop 443 * explicitly specified. 444 */ 445 if (opts && opts->ip6po_nexthop) 446 goto done; 447 448 if (ro->ro_rt) { 449 ifp = ro->ro_rt->rt_ifp; 450 451 if (ifp == NULL) { /* can this really happen? */ 452 rtfree(ro->ro_rt); 453 ro->ro_rt = NULL; 454 } 455 } 456 if (ro->ro_rt == NULL) 457 error = EHOSTUNREACH; 458 rt = ro->ro_rt; 459 460 /* 461 * Check if the outgoing interface conflicts with 462 * the interface specified by ipi6_ifindex (if specified). 463 * Note that loopback interface is always okay. 464 * (this may happen when we are sending a packet to one of 465 * our own addresses.) 466 */ 467 if (opts && opts->ip6po_pktinfo && 468 opts->ip6po_pktinfo->ipi6_ifindex) { 469 if (!(ifp->if_flags & IFF_LOOPBACK) && 470 ifp->if_index != 471 opts->ip6po_pktinfo->ipi6_ifindex) { 472 error = EHOSTUNREACH; 473 goto done; 474 } 475 } 476 } 477 478 done: 479 if (ifp == NULL && rt == NULL) { 480 /* 481 * This can happen if the caller did not pass a cached route 482 * nor any other hints. We treat this case an error. 483 */ 484 error = EHOSTUNREACH; 485 } 486 if (error == EHOSTUNREACH) 487 ip6stat.ip6s_noroute++; 488 489 if (retifp != NULL) 490 *retifp = ifp; 491 if (retrt != NULL) 492 *retrt = rt; /* rt may be NULL */ 493 494 return (error); 495} 496 497int 498in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 499 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 500 u_int rtableid) 501{ 502 struct rtentry *rt = NULL; 503 int error; 504 505 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 506 &rt, 1, rtableid)) != 0) 507 return (error); 508 509 /* 510 * do not use a rejected or black hole route. 511 * XXX: this check should be done in the L2 output routine. 512 * However, if we skipped this check here, we'd see the following 513 * scenario: 514 * - install a rejected route for a scoped address prefix 515 * (like fe80::/10) 516 * - send a packet to a destination that matches the scoped prefix, 517 * with ambiguity about the scope zone. 518 * - pick the outgoing interface from the route, and disambiguate the 519 * scope zone with the interface. 520 * - ip6_output() would try to get another route with the "new" 521 * destination, which may be valid. 522 * - we'd see no error on output. 523 * Although this may not be very harmful, it should still be confusing. 524 * We thus reject the case here. 525 */ 526 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 527 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 528 529 /* 530 * Adjust the "outgoing" interface. If we're going to loop the packet 531 * back to ourselves, the ifp would be the loopback interface. 532 * However, we'd rather know the interface associated to the 533 * destination address (which should probably be one of our own 534 * addresses.) 535 */ 536 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 537 *retifp = rt->rt_ifa->ifa_ifp; 538 539 return (0); 540} 541 542int 543in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 544 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 545 struct rtentry **retrt, u_int rtableid) 546{ 547 548 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 549 rtableid)); 550} 551 552/* 553 * Default hop limit selection. The precedence is as follows: 554 * 1. Hoplimit value specified via ioctl. 555 * 2. (If the outgoing interface is detected) the current 556 * hop limit of the interface specified by router advertisement. 557 * 3. The system default hoplimit. 558*/ 559int 560in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 561{ 562 if (in6p && in6p->inp_hops >= 0) 563 return (in6p->inp_hops); 564 else if (ifp) 565 return (ND_IFINFO(ifp)->chlim); 566 else 567 return (ip6_defhlim); 568} 569 570/* 571 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 572 * If the address scope of is link-local, embed the interface index in the 573 * address. The routine determines our precedence 574 * between advanced API scope/interface specification and basic API 575 * specification. 576 * 577 * this function should be nuked in the future, when we get rid of 578 * embedded scopeid thing. 579 * 580 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 581 * there can be multiple interfaces that belong to a particular scope zone 582 * (in specification, we have 1:N mapping between a scope zone and interfaces). 583 * we may want to change the function to return something other than ifp. 584 */ 585int 586in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, 587 struct inpcb *in6p, struct ifnet **ifpp) 588{ 589 struct ifnet *ifp = NULL; 590 u_int32_t scopeid; 591 592 *in6 = sin6->sin6_addr; 593 scopeid = sin6->sin6_scope_id; 594 if (ifpp) 595 *ifpp = NULL; 596 597 /* 598 * don't try to read sin6->sin6_addr beyond here, since the caller may 599 * ask us to overwrite existing sockaddr_in6 600 */ 601 602 if (IN6_IS_SCOPE_EMBED(in6)) { 603 struct in6_pktinfo *pi; 604 605 /* 606 * KAME assumption: link id == interface id 607 */ 608 609 if (in6p && in6p->inp_outputopts6 && 610 (pi = in6p->inp_outputopts6->ip6po_pktinfo) && 611 pi->ipi6_ifindex) { 612 ifp = if_get(pi->ipi6_ifindex); 613 if (ifp == NULL) 614 return ENXIO; /* XXX EINVAL? */ 615 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 616 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 617 in6p->inp_moptions6 && 618 (ifp = if_get(in6p->inp_moptions6->im6o_ifidx))) { 619 in6->s6_addr16[1] = htons(ifp->if_index); 620 } else if (scopeid) { 621 ifp = if_get(scopeid); 622 if (ifp == NULL) 623 return ENXIO; /* XXX EINVAL? */ 624 /*XXX assignment to 16bit from 32bit variable */ 625 in6->s6_addr16[1] = htons(scopeid & 0xffff); 626 } 627 628 if (ifpp) 629 *ifpp = ifp; 630 } 631 632 return 0; 633} 634 635/* 636 * generate standard sockaddr_in6 from embedded form. 637 * touches sin6_addr and sin6_scope_id only. 638 * 639 * this function should be nuked in the future, when we get rid of 640 * embedded scopeid thing. 641 */ 642int 643in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 644 struct ifnet *ifp) 645{ 646 u_int32_t scopeid; 647 648 sin6->sin6_addr = *in6; 649 650 /* 651 * don't try to read *in6 beyond here, since the caller may 652 * ask us to overwrite existing sockaddr_in6 653 */ 654 655 sin6->sin6_scope_id = 0; 656 if (IN6_IS_SCOPE_EMBED(in6)) { 657 /* 658 * KAME assumption: link id == interface id 659 */ 660 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 661 if (scopeid) { 662 /* sanity check */ 663 if (if_get(scopeid) == NULL) 664 return ENXIO; 665 if (ifp && ifp->if_index != scopeid) 666 return ENXIO; 667 sin6->sin6_addr.s6_addr16[1] = 0; 668 sin6->sin6_scope_id = scopeid; 669 } 670 } 671 672 return 0; 673} 674 675/* 676 * just clear the embedded scope identifer. 677 */ 678void 679in6_clearscope(struct in6_addr *addr) 680{ 681 if (IN6_IS_SCOPE_EMBED(addr)) 682 addr->s6_addr16[1] = 0; 683} 684