in6_src.c revision 1.42
1/* $OpenBSD: in6_src.c,v 1.42 2014/04/18 10:48:30 jca 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/malloc.h> 67#include <sys/mbuf.h> 68#include <sys/protosw.h> 69#include <sys/socket.h> 70#include <sys/socketvar.h> 71#include <sys/ioctl.h> 72#include <sys/errno.h> 73#include <sys/time.h> 74 75#include <net/if.h> 76#include <net/route.h> 77 78#include <netinet/in.h> 79#include <netinet/in_systm.h> 80#include <netinet/ip.h> 81#include <netinet/in_pcb.h> 82#include <netinet6/in6_var.h> 83#include <netinet/ip6.h> 84#include <netinet6/ip6_var.h> 85#include <netinet6/nd6.h> 86 87int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 88 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 89int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 90 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 91 struct rtentry **, int, u_int); 92 93/* 94 * Return an IPv6 address, which is the most appropriate for a given 95 * destination and user specified options. 96 * If necessary, this function lookups the routing table and returns 97 * an entry to the caller for later use. 98 */ 99int 100in6_selectsrc(struct in6_addr **in6src, struct sockaddr_in6 *dstsock, 101 struct ip6_pktopts *opts, struct ip6_moptions *mopts, 102 struct route_in6 *ro, struct in6_addr *laddr, u_int rtableid) 103{ 104 struct ifnet *ifp = NULL; 105 struct in6_addr *dst; 106 struct in6_ifaddr *ia6 = NULL; 107 struct in6_pktinfo *pi = NULL; 108 int error; 109 110 dst = &dstsock->sin6_addr; 111 112 /* 113 * If the source address is explicitly specified by the caller, 114 * check if the requested source address is indeed a unicast address 115 * assigned to the node, and can be used as the packet's source 116 * address. If everything is okay, use the address as source. 117 */ 118 if (opts && (pi = opts->ip6po_pktinfo) && 119 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 120 struct sockaddr_in6 sa6; 121 122 /* get the outgoing interface */ 123 error = in6_selectif(dstsock, opts, mopts, ro, &ifp, rtableid); 124 if (error) 125 return (error); 126 127 bzero(&sa6, sizeof(sa6)); 128 sa6.sin6_family = AF_INET6; 129 sa6.sin6_len = sizeof(sa6); 130 sa6.sin6_addr = pi->ipi6_addr; 131 132 if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr)) 133 sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 134 135 ia6 = ifatoia6(ifa_ifwithaddr(sin6tosa(&sa6), rtableid)); 136 if (ia6 == NULL || 137 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) 138 return (EADDRNOTAVAIL); 139 140 pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */ 141 142 *in6src = &pi->ipi6_addr; 143 return (0); 144 } 145 146 /* 147 * If the source address is not specified but the socket(if any) 148 * is already bound, use the bound address. 149 */ 150 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { 151 *in6src = laddr; 152 return (0); 153 } 154 155 /* 156 * If the caller doesn't specify the source address but 157 * the outgoing interface, use an address associated with 158 * the interface. 159 */ 160 if (pi && pi->ipi6_ifindex) { 161 ifp = if_get(pi->ipi6_ifindex); 162 if (ifp == NULL) 163 return (ENXIO); /* XXX: better error? */ 164 165 ia6 = in6_ifawithscope(ifp, dst, rtableid); 166 if (ia6 == NULL) 167 return (EADDRNOTAVAIL); 168 169 *in6src = &ia6->ia_addr.sin6_addr; 170 return (0); 171 } 172 173 /* 174 * If the destination address is a link-local unicast address or 175 * a link/interface-local multicast address, and if the outgoing 176 * interface is specified by the sin6_scope_id filed, use an address 177 * associated with the interface. 178 * XXX: We're now trying to define more specific semantics of 179 * sin6_scope_id field, so this part will be rewritten in 180 * the near future. 181 */ 182 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) || 183 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) { 184 ifp = if_get(dstsock->sin6_scope_id); 185 if (ifp == NULL) 186 return (ENXIO); /* XXX: better error? */ 187 188 ia6 = in6_ifawithscope(ifp, dst, rtableid); 189 if (ia6 == NULL) 190 return (EADDRNOTAVAIL); 191 192 *in6src = &ia6->ia_addr.sin6_addr; 193 return (0); 194 } 195 196 /* 197 * If the destination address is a multicast address and 198 * the outgoing interface for the address is specified 199 * by the caller, use an address associated with the interface. 200 * Even if the outgoing interface is not specified, we also 201 * choose a loopback interface as the outgoing interface. 202 */ 203 if (IN6_IS_ADDR_MULTICAST(dst)) { 204 ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 205 206 if (!ifp && dstsock->sin6_scope_id) 207 ifp = if_get(htons(dstsock->sin6_scope_id)); 208 209 if (ifp) { 210 ia6 = in6_ifawithscope(ifp, dst, rtableid); 211 if (ia6 == NULL) 212 return (EADDRNOTAVAIL); 213 214 *in6src = &ia6->ia_addr.sin6_addr; 215 return (0); 216 } 217 } 218 219 /* 220 * If the next hop address for the packet is specified 221 * by caller, use an address associated with the route 222 * to the next hop. 223 */ 224 { 225 struct sockaddr_in6 *sin6_next; 226 struct rtentry *rt; 227 228 if (opts && opts->ip6po_nexthop) { 229 sin6_next = satosin6(opts->ip6po_nexthop); 230 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL, 231 rtableid); 232 if (rt) { 233 ia6 = in6_ifawithscope(rt->rt_ifp, dst, 234 rtableid); 235 if (ia6 == 0) 236 ia6 = ifatoia6(rt->rt_ifa); 237 } 238 if (ia6 == NULL) 239 return (EADDRNOTAVAIL); 240 241 *in6src = &ia6->ia_addr.sin6_addr; 242 return (0); 243 } 244 } 245 246 /* 247 * If route is known or can be allocated now, 248 * our src addr is taken from the i/f, else punt. 249 */ 250 if (ro) { 251 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 252 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 253 RTFREE(ro->ro_rt); 254 ro->ro_rt = (struct rtentry *)0; 255 } 256 if (ro->ro_rt == (struct rtentry *)0 || 257 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 258 struct sockaddr_in6 *sa6; 259 260 /* No route yet, so try to acquire one */ 261 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 262 ro->ro_tableid = rtableid; 263 sa6 = &ro->ro_dst; 264 sa6->sin6_family = AF_INET6; 265 sa6->sin6_len = sizeof(struct sockaddr_in6); 266 sa6->sin6_addr = *dst; 267 sa6->sin6_scope_id = dstsock->sin6_scope_id; 268 if (IN6_IS_ADDR_MULTICAST(dst)) { 269 rtalloc((struct route *)ro); 270 } else { 271 rtalloc_mpath((struct route *)ro, NULL); 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 == 0) /* 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 = mopts->im6o_multicast_ifp) != 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 rtalloc((struct route *)ron); /* multi path case? */ 386 if (ron->ro_rt == NULL || 387 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 388 if (ron->ro_rt) { 389 RTFREE(ron->ro_rt); 390 ron->ro_rt = NULL; 391 } 392 error = EHOSTUNREACH; 393 goto done; 394 } 395 } 396 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 397 RTFREE(ron->ro_rt); 398 ron->ro_rt = NULL; 399 error = EHOSTUNREACH; 400 goto done; 401 } 402 rt = ron->ro_rt; 403 ifp = rt->rt_ifp; 404 405 /* 406 * When cloning is required, try to allocate a route to the 407 * destination so that the caller can store path MTU 408 * information. 409 */ 410 goto done; 411 } 412 413 /* 414 * Use a cached route if it exists and is valid, else try to allocate 415 * a new one. Note that we should check the address family of the 416 * cached destination, in case of sharing the cache with IPv4. 417 */ 418 if (ro) { 419 if (ro->ro_rt && 420 (!(ro->ro_rt->rt_flags & RTF_UP) || 421 sin6tosa(&ro->ro_dst)->sa_family != AF_INET6 || 422 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 423 RTFREE(ro->ro_rt); 424 ro->ro_rt = (struct rtentry *)NULL; 425 } 426 if (ro->ro_rt == (struct rtentry *)NULL) { 427 struct sockaddr_in6 *sa6; 428 429 /* No route yet, so try to acquire one */ 430 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 431 ro->ro_tableid = rtableid; 432 sa6 = &ro->ro_dst; 433 *sa6 = *dstsock; 434 sa6->sin6_scope_id = 0; 435 ro->ro_tableid = rtableid; 436 rtalloc_mpath((struct route *)ro, NULL); 437 } 438 439 /* 440 * do not care about the result if we have the nexthop 441 * explicitly specified. 442 */ 443 if (opts && opts->ip6po_nexthop) 444 goto done; 445 446 if (ro->ro_rt) { 447 ifp = ro->ro_rt->rt_ifp; 448 449 if (ifp == NULL) { /* can this really happen? */ 450 RTFREE(ro->ro_rt); 451 ro->ro_rt = NULL; 452 } 453 } 454 if (ro->ro_rt == NULL) 455 error = EHOSTUNREACH; 456 rt = ro->ro_rt; 457 458 /* 459 * Check if the outgoing interface conflicts with 460 * the interface specified by ipi6_ifindex (if specified). 461 * Note that loopback interface is always okay. 462 * (this may happen when we are sending a packet to one of 463 * our own addresses.) 464 */ 465 if (opts && opts->ip6po_pktinfo && 466 opts->ip6po_pktinfo->ipi6_ifindex) { 467 if (!(ifp->if_flags & IFF_LOOPBACK) && 468 ifp->if_index != 469 opts->ip6po_pktinfo->ipi6_ifindex) { 470 error = EHOSTUNREACH; 471 goto done; 472 } 473 } 474 } 475 476 done: 477 if (ifp == NULL && rt == NULL) { 478 /* 479 * This can happen if the caller did not pass a cached route 480 * nor any other hints. We treat this case an error. 481 */ 482 error = EHOSTUNREACH; 483 } 484 if (error == EHOSTUNREACH) 485 ip6stat.ip6s_noroute++; 486 487 if (retifp != NULL) 488 *retifp = ifp; 489 if (retrt != NULL) 490 *retrt = rt; /* rt may be NULL */ 491 492 return (error); 493} 494 495int 496in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 497 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 498 u_int rtableid) 499{ 500 struct rtentry *rt = NULL; 501 int error; 502 503 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 504 &rt, 1, rtableid)) != 0) 505 return (error); 506 507 /* 508 * do not use a rejected or black hole route. 509 * XXX: this check should be done in the L2 output routine. 510 * However, if we skipped this check here, we'd see the following 511 * scenario: 512 * - install a rejected route for a scoped address prefix 513 * (like fe80::/10) 514 * - send a packet to a destination that matches the scoped prefix, 515 * with ambiguity about the scope zone. 516 * - pick the outgoing interface from the route, and disambiguate the 517 * scope zone with the interface. 518 * - ip6_output() would try to get another route with the "new" 519 * destination, which may be valid. 520 * - we'd see no error on output. 521 * Although this may not be very harmful, it should still be confusing. 522 * We thus reject the case here. 523 */ 524 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 525 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 526 527 /* 528 * Adjust the "outgoing" interface. If we're going to loop the packet 529 * back to ourselves, the ifp would be the loopback interface. 530 * However, we'd rather know the interface associated to the 531 * destination address (which should probably be one of our own 532 * addresses.) 533 */ 534 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 535 *retifp = rt->rt_ifa->ifa_ifp; 536 537 return (0); 538} 539 540int 541in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 542 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 543 struct rtentry **retrt, u_int rtableid) 544{ 545 546 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 547 rtableid)); 548} 549 550/* 551 * Default hop limit selection. The precedence is as follows: 552 * 1. Hoplimit value specified via ioctl. 553 * 2. (If the outgoing interface is detected) the current 554 * hop limit of the interface specified by router advertisement. 555 * 3. The system default hoplimit. 556*/ 557int 558in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 559{ 560 if (in6p && in6p->inp_hops >= 0) 561 return (in6p->inp_hops); 562 else if (ifp) 563 return (ND_IFINFO(ifp)->chlim); 564 else 565 return (ip6_defhlim); 566} 567 568/* 569 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 570 * If the address scope of is link-local, embed the interface index in the 571 * address. The routine determines our precedence 572 * between advanced API scope/interface specification and basic API 573 * specification. 574 * 575 * this function should be nuked in the future, when we get rid of 576 * embedded scopeid thing. 577 * 578 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 579 * there can be multiple interfaces that belong to a particular scope zone 580 * (in specification, we have 1:N mapping between a scope zone and interfaces). 581 * we may want to change the function to return something other than ifp. 582 */ 583int 584in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, 585 struct inpcb *in6p, struct ifnet **ifpp) 586{ 587 struct ifnet *ifp = NULL; 588 u_int32_t scopeid; 589 590 *in6 = sin6->sin6_addr; 591 scopeid = sin6->sin6_scope_id; 592 if (ifpp) 593 *ifpp = NULL; 594 595 /* 596 * don't try to read sin6->sin6_addr beyond here, since the caller may 597 * ask us to overwrite existing sockaddr_in6 598 */ 599 600 if (IN6_IS_SCOPE_EMBED(in6)) { 601 struct in6_pktinfo *pi; 602 603 /* 604 * KAME assumption: link id == interface id 605 */ 606 607 if (in6p && in6p->inp_outputopts6 && 608 (pi = in6p->inp_outputopts6->ip6po_pktinfo) && 609 pi->ipi6_ifindex) { 610 ifp = if_get(pi->ipi6_ifindex); 611 if (ifp == NULL) 612 return ENXIO; /* XXX EINVAL? */ 613 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 614 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 615 in6p->inp_moptions6 && 616 in6p->inp_moptions6->im6o_multicast_ifp) { 617 ifp = in6p->inp_moptions6->im6o_multicast_ifp; 618 in6->s6_addr16[1] = htons(ifp->if_index); 619 } else if (scopeid) { 620 ifp = if_get(scopeid); 621 if (ifp == NULL) 622 return ENXIO; /* XXX EINVAL? */ 623 /*XXX assignment to 16bit from 32bit variable */ 624 in6->s6_addr16[1] = htons(scopeid & 0xffff); 625 } 626 627 if (ifpp) 628 *ifpp = ifp; 629 } 630 631 return 0; 632} 633 634/* 635 * generate standard sockaddr_in6 from embedded form. 636 * touches sin6_addr and sin6_scope_id only. 637 * 638 * this function should be nuked in the future, when we get rid of 639 * embedded scopeid thing. 640 */ 641int 642in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 643 struct ifnet *ifp) 644{ 645 u_int32_t scopeid; 646 647 sin6->sin6_addr = *in6; 648 649 /* 650 * don't try to read *in6 beyond here, since the caller may 651 * ask us to overwrite existing sockaddr_in6 652 */ 653 654 sin6->sin6_scope_id = 0; 655 if (IN6_IS_SCOPE_EMBED(in6)) { 656 /* 657 * KAME assumption: link id == interface id 658 */ 659 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 660 if (scopeid) { 661 /* sanity check */ 662 if (if_get(scopeid) == NULL) 663 return ENXIO; 664 if (ifp && ifp->if_index != scopeid) 665 return ENXIO; 666 sin6->sin6_addr.s6_addr16[1] = 0; 667 sin6->sin6_scope_id = scopeid; 668 } 669 } 670 671 return 0; 672} 673 674/* 675 * just clear the embedded scope identifer. 676 */ 677void 678in6_clearscope(struct in6_addr *addr) 679{ 680 if (IN6_IS_SCOPE_EMBED(addr)) 681 addr->s6_addr16[1] = 0; 682} 683