in6_src.c revision 1.59
1/* $OpenBSD: in6_src.c,v 1.59 2015/09/11 13:53:04 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); 88 89/* 90 * Return an IPv6 address, which is the most appropriate for a given 91 * destination and user specified options. 92 * If necessary, this function lookups the routing table and returns 93 * an entry to the caller for later use. 94 */ 95int 96in6_selectsrc(struct in6_addr **in6src, struct sockaddr_in6 *dstsock, 97 struct ip6_pktopts *opts, struct ip6_moptions *mopts, 98 struct route_in6 *ro, struct in6_addr *laddr, u_int rtableid) 99{ 100 struct ifnet *ifp = NULL; 101 struct in6_addr *dst; 102 struct in6_ifaddr *ia6 = NULL; 103 struct in6_pktinfo *pi = NULL; 104 int error; 105 106 dst = &dstsock->sin6_addr; 107 108 /* 109 * If the source address is explicitly specified by the caller, 110 * check if the requested source address is indeed a unicast address 111 * assigned to the node, and can be used as the packet's source 112 * address. If everything is okay, use the address as source. 113 */ 114 if (opts && (pi = opts->ip6po_pktinfo) && 115 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 116 struct sockaddr_in6 sa6; 117 118 /* get the outgoing interface */ 119 error = in6_selectif(dstsock, opts, mopts, ro, &ifp, rtableid); 120 if (error) 121 return (error); 122 123 bzero(&sa6, sizeof(sa6)); 124 sa6.sin6_family = AF_INET6; 125 sa6.sin6_len = sizeof(sa6); 126 sa6.sin6_addr = pi->ipi6_addr; 127 128 if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr)) 129 sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 130 131 ia6 = ifatoia6(ifa_ifwithaddr(sin6tosa(&sa6), rtableid)); 132 if (ia6 == NULL || 133 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) 134 return (EADDRNOTAVAIL); 135 136 pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */ 137 138 *in6src = &pi->ipi6_addr; 139 return (0); 140 } 141 142 /* 143 * If the source address is not specified but the socket(if any) 144 * is already bound, use the bound address. 145 */ 146 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { 147 *in6src = laddr; 148 return (0); 149 } 150 151 /* 152 * If the caller doesn't specify the source address but 153 * the outgoing interface, use an address associated with 154 * the interface. 155 */ 156 if (pi && pi->ipi6_ifindex) { 157 ifp = if_get(pi->ipi6_ifindex); 158 if (ifp == NULL) 159 return (ENXIO); /* XXX: better error? */ 160 161 ia6 = in6_ifawithscope(ifp, dst, rtableid); 162 if (ia6 == NULL) 163 return (EADDRNOTAVAIL); 164 165 *in6src = &ia6->ia_addr.sin6_addr; 166 return (0); 167 } 168 169 /* 170 * If the destination address is a link-local unicast address or 171 * a link/interface-local multicast address, and if the outgoing 172 * interface is specified by the sin6_scope_id filed, use an address 173 * associated with the interface. 174 * XXX: We're now trying to define more specific semantics of 175 * sin6_scope_id field, so this part will be rewritten in 176 * the near future. 177 */ 178 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) || 179 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) { 180 ifp = if_get(dstsock->sin6_scope_id); 181 if (ifp == NULL) 182 return (ENXIO); /* XXX: better error? */ 183 184 ia6 = in6_ifawithscope(ifp, dst, rtableid); 185 if (ia6 == NULL) 186 return (EADDRNOTAVAIL); 187 188 *in6src = &ia6->ia_addr.sin6_addr; 189 return (0); 190 } 191 192 /* 193 * If the destination address is a multicast address and 194 * the outgoing interface for the address is specified 195 * by the caller, use an address associated with the interface. 196 * Even if the outgoing interface is not specified, we also 197 * choose a loopback interface as the outgoing interface. 198 */ 199 if (IN6_IS_ADDR_MULTICAST(dst)) { 200 ifp = mopts ? if_get(mopts->im6o_ifidx) : NULL; 201 202 if (!ifp && dstsock->sin6_scope_id) 203 ifp = if_get(htons(dstsock->sin6_scope_id)); 204 205 if (ifp) { 206 ia6 = in6_ifawithscope(ifp, dst, rtableid); 207 if (ia6 == NULL) 208 return (EADDRNOTAVAIL); 209 210 *in6src = &ia6->ia_addr.sin6_addr; 211 return (0); 212 } 213 } 214 215 /* 216 * If the next hop address for the packet is specified 217 * by caller, use an address associated with the route 218 * to the next hop. 219 */ 220 { 221 struct sockaddr_in6 *sin6_next; 222 struct rtentry *rt; 223 224 if (opts && opts->ip6po_nexthop) { 225 sin6_next = satosin6(opts->ip6po_nexthop); 226 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL, 227 rtableid); 228 if (rt) { 229 ia6 = in6_ifawithscope(rt->rt_ifp, dst, 230 rtableid); 231 if (ia6 == NULL) 232 ia6 = ifatoia6(rt->rt_ifa); 233 } 234 if (ia6 == NULL) 235 return (EADDRNOTAVAIL); 236 237 *in6src = &ia6->ia_addr.sin6_addr; 238 return (0); 239 } 240 } 241 242 /* 243 * If route is known or can be allocated now, 244 * our src addr is taken from the i/f, else punt. 245 */ 246 if (ro) { 247 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 248 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 249 rtfree(ro->ro_rt); 250 ro->ro_rt = NULL; 251 } 252 if (ro->ro_rt == (struct rtentry *)0 || 253 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 254 struct sockaddr_in6 *sa6; 255 256 /* No route yet, so try to acquire one */ 257 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 258 ro->ro_tableid = rtableid; 259 sa6 = &ro->ro_dst; 260 sa6->sin6_family = AF_INET6; 261 sa6->sin6_len = sizeof(struct sockaddr_in6); 262 sa6->sin6_addr = *dst; 263 sa6->sin6_scope_id = dstsock->sin6_scope_id; 264 if (IN6_IS_ADDR_MULTICAST(dst)) { 265 ro->ro_rt = rtalloc(sin6tosa(&ro->ro_dst), 266 RT_REPORT|RT_RESOLVE, ro->ro_tableid); 267 } else { 268 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 269 NULL, ro->ro_tableid); 270 } 271 } 272 273 /* 274 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 275 * the address. But we don't know why it does so. 276 * It is necessary to ensure the scope even for lo0 277 * so doesn't check out IFF_LOOPBACK. 278 */ 279 280 if (ro->ro_rt) { 281 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, 282 rtableid); 283 if (ia6 == NULL) /* xxx scope error ?*/ 284 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 285 } 286 if (ia6 == NULL) 287 return (EHOSTUNREACH); /* no route */ 288 289 *in6src = &ia6->ia_addr.sin6_addr; 290 return (0); 291 } 292 293 return (EADDRNOTAVAIL); 294} 295 296int 297in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 298 struct route_in6 *ro, struct ifnet **retifp, 299 struct rtentry **retrt, unsigned int rtableid) 300{ 301 int error = 0; 302 struct ifnet *ifp = NULL; 303 struct rtentry *rt = NULL; 304 struct sockaddr_in6 *sin6_next; 305 struct in6_addr *dst; 306 307 dst = &dstsock->sin6_addr; 308 309 /* 310 * If the next hop address for the packet is specified by the caller, 311 * use it as the gateway. 312 */ 313 if (opts && opts->ip6po_nexthop) { 314 struct route_in6 *ron; 315 316 sin6_next = satosin6(opts->ip6po_nexthop); 317 318 /* at this moment, we only support AF_INET6 next hops */ 319 if (sin6_next->sin6_family != AF_INET6) { 320 error = EAFNOSUPPORT; /* or should we proceed? */ 321 goto done; 322 } 323 324 /* 325 * If the next hop is an IPv6 address, then the node identified 326 * by that address must be a neighbor of the sending host. 327 */ 328 ron = &opts->ip6po_nextroute; 329 if ((ron->ro_rt && 330 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 331 RTF_UP) || 332 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 333 &sin6_next->sin6_addr)) { 334 if (ron->ro_rt) { 335 rtfree(ron->ro_rt); 336 ron->ro_rt = NULL; 337 } 338 ron->ro_dst = *sin6_next; 339 ron->ro_tableid = rtableid; 340 } 341 if (ron->ro_rt == NULL) { 342 /* multi path case? */ 343 ron->ro_rt = rtalloc(sin6tosa(&ron->ro_dst), 344 RT_REPORT|RT_RESOLVE, ron->ro_tableid); 345 if (ron->ro_rt == NULL || 346 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 347 if (ron->ro_rt) { 348 rtfree(ron->ro_rt); 349 ron->ro_rt = NULL; 350 } 351 error = EHOSTUNREACH; 352 goto done; 353 } 354 } 355 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 356 rtfree(ron->ro_rt); 357 ron->ro_rt = NULL; 358 error = EHOSTUNREACH; 359 goto done; 360 } 361 rt = ron->ro_rt; 362 ifp = rt->rt_ifp; 363 364 /* 365 * When cloning is required, try to allocate a route to the 366 * destination so that the caller can store path MTU 367 * information. 368 */ 369 goto done; 370 } 371 372 /* 373 * Use a cached route if it exists and is valid, else try to allocate 374 * a new one. Note that we should check the address family of the 375 * cached destination, in case of sharing the cache with IPv4. 376 */ 377 if (ro) { 378 if (ro->ro_rt && 379 (!(ro->ro_rt->rt_flags & RTF_UP) || 380 sin6tosa(&ro->ro_dst)->sa_family != AF_INET6 || 381 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 382 rtfree(ro->ro_rt); 383 ro->ro_rt = NULL; 384 } 385 if (ro->ro_rt == NULL) { 386 struct sockaddr_in6 *sa6; 387 388 /* No route yet, so try to acquire one */ 389 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 390 ro->ro_tableid = rtableid; 391 sa6 = &ro->ro_dst; 392 *sa6 = *dstsock; 393 sa6->sin6_scope_id = 0; 394 ro->ro_tableid = rtableid; 395 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 396 NULL, ro->ro_tableid); 397 } 398 399 /* 400 * do not care about the result if we have the nexthop 401 * explicitly specified. 402 */ 403 if (opts && opts->ip6po_nexthop) 404 goto done; 405 406 if (ro->ro_rt) { 407 ifp = ro->ro_rt->rt_ifp; 408 409 if (ifp == NULL) { /* can this really happen? */ 410 rtfree(ro->ro_rt); 411 ro->ro_rt = NULL; 412 } 413 } 414 if (ro->ro_rt == NULL) 415 error = EHOSTUNREACH; 416 rt = ro->ro_rt; 417 418 /* 419 * Check if the outgoing interface conflicts with 420 * the interface specified by ipi6_ifindex (if specified). 421 * Note that loopback interface is always okay. 422 * (this may happen when we are sending a packet to one of 423 * our own addresses.) 424 */ 425 if (opts && opts->ip6po_pktinfo && 426 opts->ip6po_pktinfo->ipi6_ifindex) { 427 if (!(ifp->if_flags & IFF_LOOPBACK) && 428 ifp->if_index != 429 opts->ip6po_pktinfo->ipi6_ifindex) { 430 error = EHOSTUNREACH; 431 goto done; 432 } 433 } 434 } 435 436 done: 437 if (ifp == NULL && rt == NULL) { 438 /* 439 * This can happen if the caller did not pass a cached route 440 * nor any other hints. We treat this case an error. 441 */ 442 error = EHOSTUNREACH; 443 } 444 445 if (retifp != NULL) 446 *retifp = ifp; 447 if (retrt != NULL) 448 *retrt = rt; /* rt may be NULL */ 449 450 return (error); 451} 452 453int 454in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 455 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 456 u_int rtableid) 457{ 458 struct rtentry *rt = NULL; 459 struct in6_pktinfo *pi = NULL; 460 int error; 461 462 /* If the caller specify the outgoing interface explicitly, use it. */ 463 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 464 *retifp = if_get(pi->ipi6_ifindex); 465 if (*retifp != NULL) 466 return (0); 467 } 468 469 /* 470 * If the destination address is a multicast address and the outgoing 471 * interface for the address is specified by the caller, use it. 472 */ 473 if (IN6_IS_ADDR_MULTICAST(&dstsock->sin6_addr) && 474 mopts != NULL && (*retifp = if_get(mopts->im6o_ifidx)) != NULL) 475 return (0); 476 477 if ((error = in6_selectroute(dstsock, opts, ro, retifp, 478 &rt, rtableid)) != 0) 479 return (error); 480 481 /* 482 * do not use a rejected or black hole route. 483 * XXX: this check should be done in the L2 output routine. 484 * However, if we skipped this check here, we'd see the following 485 * scenario: 486 * - install a rejected route for a scoped address prefix 487 * (like fe80::/10) 488 * - send a packet to a destination that matches the scoped prefix, 489 * with ambiguity about the scope zone. 490 * - pick the outgoing interface from the route, and disambiguate the 491 * scope zone with the interface. 492 * - ip6_output() would try to get another route with the "new" 493 * destination, which may be valid. 494 * - we'd see no error on output. 495 * Although this may not be very harmful, it should still be confusing. 496 * We thus reject the case here. 497 */ 498 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 499 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 500 501 /* 502 * Adjust the "outgoing" interface. If we're going to loop the packet 503 * back to ourselves, the ifp would be the loopback interface. 504 * However, we'd rather know the interface associated to the 505 * destination address (which should probably be one of our own 506 * addresses.) 507 */ 508 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 509 *retifp = rt->rt_ifa->ifa_ifp; 510 511 return (0); 512} 513 514/* 515 * Default hop limit selection. The precedence is as follows: 516 * 1. Hoplimit value specified via ioctl. 517 * 2. (If the outgoing interface is detected) the current 518 * hop limit of the interface specified by router advertisement. 519 * 3. The system default hoplimit. 520*/ 521int 522in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 523{ 524 if (in6p && in6p->inp_hops >= 0) 525 return (in6p->inp_hops); 526 else if (ifp) 527 return (ND_IFINFO(ifp)->chlim); 528 else 529 return (ip6_defhlim); 530} 531 532/* 533 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 534 * If the address scope of is link-local, embed the interface index in the 535 * address. The routine determines our precedence 536 * between advanced API scope/interface specification and basic API 537 * specification. 538 * 539 * this function should be nuked in the future, when we get rid of 540 * embedded scopeid thing. 541 * 542 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 543 * there can be multiple interfaces that belong to a particular scope zone 544 * (in specification, we have 1:N mapping between a scope zone and interfaces). 545 * we may want to change the function to return something other than ifp. 546 */ 547int 548in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, 549 struct inpcb *in6p) 550{ 551 struct ifnet *ifp = NULL; 552 u_int32_t scopeid; 553 554 *in6 = sin6->sin6_addr; 555 scopeid = sin6->sin6_scope_id; 556 557 /* 558 * don't try to read sin6->sin6_addr beyond here, since the caller may 559 * ask us to overwrite existing sockaddr_in6 560 */ 561 562 if (IN6_IS_SCOPE_EMBED(in6)) { 563 struct in6_pktinfo *pi; 564 565 /* 566 * KAME assumption: link id == interface id 567 */ 568 569 if (in6p && in6p->inp_outputopts6 && 570 (pi = in6p->inp_outputopts6->ip6po_pktinfo) && 571 pi->ipi6_ifindex) { 572 ifp = if_get(pi->ipi6_ifindex); 573 if (ifp == NULL) 574 return ENXIO; /* XXX EINVAL? */ 575 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 576 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 577 in6p->inp_moptions6 && 578 (ifp = if_get(in6p->inp_moptions6->im6o_ifidx))) { 579 in6->s6_addr16[1] = htons(ifp->if_index); 580 } else if (scopeid) { 581 ifp = if_get(scopeid); 582 if (ifp == NULL) 583 return ENXIO; /* XXX EINVAL? */ 584 /*XXX assignment to 16bit from 32bit variable */ 585 in6->s6_addr16[1] = htons(scopeid & 0xffff); 586 } 587 if_put(ifp); 588 } 589 590 return 0; 591} 592 593/* 594 * generate standard sockaddr_in6 from embedded form. 595 * touches sin6_addr and sin6_scope_id only. 596 * 597 * this function should be nuked in the future, when we get rid of 598 * embedded scopeid thing. 599 */ 600void 601in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6) 602{ 603 u_int32_t scopeid; 604 605 sin6->sin6_addr = *in6; 606 607 /* 608 * don't try to read *in6 beyond here, since the caller may 609 * ask us to overwrite existing sockaddr_in6 610 */ 611 612 sin6->sin6_scope_id = 0; 613 if (IN6_IS_SCOPE_EMBED(in6)) { 614 /* 615 * KAME assumption: link id == interface id 616 */ 617 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 618 if (scopeid) { 619 sin6->sin6_addr.s6_addr16[1] = 0; 620 sin6->sin6_scope_id = scopeid; 621 } 622 } 623} 624 625/* 626 * just clear the embedded scope identifer. 627 */ 628void 629in6_clearscope(struct in6_addr *addr) 630{ 631 if (IN6_IS_SCOPE_EMBED(addr)) 632 addr->s6_addr16[1] = 0; 633} 634