in6_src.c revision 1.29
1/* $OpenBSD: in6_src.c,v 1.29 2013/03/20 10:34:12 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/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#include <sys/proc.h> 75 76#include <net/if.h> 77#include <net/route.h> 78 79#include <netinet/in.h> 80#include <netinet/in_var.h> 81#include <netinet/in_systm.h> 82#include <netinet/ip.h> 83#include <netinet/in_pcb.h> 84#include <netinet6/in6_var.h> 85#include <netinet/ip6.h> 86#include <netinet6/ip6_var.h> 87#include <netinet6/nd6.h> 88 89int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 90 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 91int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 92 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 93 struct rtentry **, int, u_int); 94 95/* 96 * Return an IPv6 address, which is the most appropriate for a given 97 * destination and user specified options. 98 * If necessary, this function lookups the routing table and returns 99 * an entry to the caller for later use. 100 */ 101struct in6_addr * 102in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 103 struct ip6_moptions *mopts, struct route_in6 *ro, struct in6_addr *laddr, 104 int *errorp, u_int rtableid) 105{ 106 struct ifnet *ifp = NULL; 107 struct in6_addr *dst; 108 struct in6_ifaddr *ia6 = NULL; 109 struct in6_pktinfo *pi = NULL; 110 111 dst = &dstsock->sin6_addr; 112 *errorp = 0; 113 114 /* 115 * If the source address is explicitly specified by the caller, 116 * check if the requested source address is indeed a unicast address 117 * assigned to the node, and can be used as the packet's source 118 * address. If everything is okay, use the address as source. 119 */ 120 if (opts && (pi = opts->ip6po_pktinfo) && 121 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 122 struct sockaddr_in6 sa6; 123 124 /* get the outgoing interface */ 125 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, 126 &ifp, rtableid)) != 0) 127 return (NULL); 128 129 bzero(&sa6, sizeof(sa6)); 130 sa6.sin6_family = AF_INET6; 131 sa6.sin6_len = sizeof(sa6); 132 sa6.sin6_addr = pi->ipi6_addr; 133 134 if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr)) 135 sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 136 137 ia6 = ifatoia6( 138 ifa_ifwithaddr((struct sockaddr *)&sa6, rtableid)); 139 if (ia6 == NULL || 140 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 141 *errorp = EADDRNOTAVAIL; 142 return (NULL); 143 } 144 145 pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */ 146 147 return (&pi->ipi6_addr); 148 } 149 150 /* 151 * If the source address is not specified but the socket(if any) 152 * is already bound, use the bound address. 153 */ 154 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 155 return (laddr); 156 157 /* 158 * If the caller doesn't specify the source address but 159 * the outgoing interface, use an address associated with 160 * the interface. 161 */ 162 if (pi && pi->ipi6_ifindex) { 163 ifp = if_get(pi->ipi6_ifindex); 164 if (ifp == NULL) { 165 *errorp = ENXIO; /* XXX: better error? */ 166 return (0); 167 } 168 ia6 = in6_ifawithscope(ifp, dst, rtableid); 169 if (ia6 == 0) { 170 *errorp = EADDRNOTAVAIL; 171 return (0); 172 } 173 return (&satosin6(&ia6->ia_addr)->sin6_addr); 174 } 175 176 /* 177 * If the destination address is a link-local unicast address or 178 * a link/interface-local multicast address, and if the outgoing 179 * interface is specified by the sin6_scope_id filed, use an address 180 * associated with the interface. 181 * XXX: We're now trying to define more specific semantics of 182 * sin6_scope_id field, so this part will be rewritten in 183 * the near future. 184 */ 185 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) || 186 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) { 187 ifp = if_get(dstsock->sin6_scope_id); 188 if (ifp == NULL) { 189 *errorp = ENXIO; /* XXX: better error? */ 190 return (0); 191 } 192 ia6 = in6_ifawithscope(ifp, dst, rtableid); 193 if (ia6 == 0) { 194 *errorp = EADDRNOTAVAIL; 195 return (0); 196 } 197 return (&satosin6(&ia6->ia_addr)->sin6_addr); 198 } 199 200 /* 201 * If the destination address is a multicast address and 202 * the outgoing interface for the address is specified 203 * by the caller, use an address associated with the interface. 204 * Even if the outgoing interface is not specified, we also 205 * choose a loopback interface as the outgoing interface. 206 */ 207 if (IN6_IS_ADDR_MULTICAST(dst)) { 208 ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 209 210 if (!ifp && dstsock->sin6_scope_id) 211 ifp = if_get(htons(dstsock->sin6_scope_id)); 212 213 if (ifp) { 214 ia6 = in6_ifawithscope(ifp, dst, rtableid); 215 if (ia6 == 0) { 216 *errorp = EADDRNOTAVAIL; 217 return (0); 218 } 219 return (&satosin6(&ia6->ia_addr)->sin6_addr); 220 } 221 } 222 223 /* 224 * If the next hop address for the packet is specified 225 * by caller, use an address associated with the route 226 * to the next hop. 227 */ 228 { 229 struct sockaddr_in6 *sin6_next; 230 struct rtentry *rt; 231 232 if (opts && opts->ip6po_nexthop) { 233 sin6_next = satosin6(opts->ip6po_nexthop); 234 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 235 if (rt) { 236 ia6 = in6_ifawithscope(rt->rt_ifp, dst, 237 rtableid); 238 if (ia6 == 0) 239 ia6 = ifatoia6(rt->rt_ifa); 240 } 241 if (ia6 == 0) { 242 *errorp = EADDRNOTAVAIL; 243 return (0); 244 } 245 return (&satosin6(&ia6->ia_addr)->sin6_addr); 246 } 247 } 248 249 /* 250 * If route is known or can be allocated now, 251 * our src addr is taken from the i/f, else punt. 252 */ 253 if (ro) { 254 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 255 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 256 RTFREE(ro->ro_rt); 257 ro->ro_rt = (struct rtentry *)0; 258 } 259 if (ro->ro_rt == (struct rtentry *)0 || 260 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 261 struct sockaddr_in6 *sa6; 262 263 /* No route yet, so try to acquire one */ 264 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 265 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 266 sa6->sin6_family = AF_INET6; 267 sa6->sin6_len = sizeof(struct sockaddr_in6); 268 sa6->sin6_addr = *dst; 269 sa6->sin6_scope_id = dstsock->sin6_scope_id; 270 if (IN6_IS_ADDR_MULTICAST(dst)) { 271 rtalloc((struct route *)ro); 272 } else { 273 rtalloc_mpath((struct route *)ro, NULL); 274 } 275 } 276 277 /* 278 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 279 * the address. But we don't know why it does so. 280 * It is necessary to ensure the scope even for lo0 281 * so doesn't check out IFF_LOOPBACK. 282 */ 283 284 if (ro->ro_rt) { 285 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, 286 rtableid); 287 if (ia6 == 0) /* xxx scope error ?*/ 288 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 289 } 290#if 0 291 /* 292 * xxx The followings are necessary? (kazu) 293 * I don't think so. 294 * It's for SO_DONTROUTE option in IPv4.(jinmei) 295 */ 296 if (ia6 == 0) { 297 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 298 299 sin6->sin6_addr = *dst; 300 301 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 302 if (ia6 == 0) 303 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 304 if (ia6 == 0) 305 return (0); 306 return (&satosin6(&ia6->ia_addr)->sin6_addr); 307 } 308#endif /* 0 */ 309 if (ia6 == 0) { 310 *errorp = EHOSTUNREACH; /* no route */ 311 return (0); 312 } 313 return (&satosin6(&ia6->ia_addr)->sin6_addr); 314 } 315 316 *errorp = EADDRNOTAVAIL; 317 return (0); 318} 319 320int 321selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 322 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 323 struct rtentry **retrt, int norouteok, u_int rtableid) 324{ 325 int error = 0; 326 struct ifnet *ifp = NULL; 327 struct rtentry *rt = NULL; 328 struct sockaddr_in6 *sin6_next; 329 struct in6_pktinfo *pi = NULL; 330 struct in6_addr *dst; 331 332 dst = &dstsock->sin6_addr; 333 334#if 0 335 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 336 dstsock->sin6_addr.s6_addr32[1] == 0 && 337 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 338 printf("in6_selectroute: strange destination %s\n", 339 ip6_sprintf(&dstsock->sin6_addr)); 340 } else { 341 printf("in6_selectroute: destination = %s%%%d\n", 342 ip6_sprintf(&dstsock->sin6_addr), 343 dstsock->sin6_scope_id); /* for debug */ 344 } 345#endif 346 347 /* If the caller specify the outgoing interface explicitly, use it. */ 348 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 349 ifp = if_get(pi->ipi6_ifindex); 350 if (ifp != NULL && 351 (norouteok || retrt == NULL || 352 IN6_IS_ADDR_MULTICAST(dst))) { 353 /* 354 * we do not have to check or get the route for 355 * multicast. 356 */ 357 goto done; 358 } else 359 goto getroute; 360 } 361 362 /* 363 * If the destination address is a multicast address and the outgoing 364 * interface for the address is specified by the caller, use it. 365 */ 366 if (IN6_IS_ADDR_MULTICAST(dst) && 367 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 368 goto done; /* we do not need a route for multicast. */ 369 } 370 371 getroute: 372 /* 373 * If the next hop address for the packet is specified by the caller, 374 * use it as the gateway. 375 */ 376 if (opts && opts->ip6po_nexthop) { 377 struct route_in6 *ron; 378 379 sin6_next = satosin6(opts->ip6po_nexthop); 380 381 /* at this moment, we only support AF_INET6 next hops */ 382 if (sin6_next->sin6_family != AF_INET6) { 383 error = EAFNOSUPPORT; /* or should we proceed? */ 384 goto done; 385 } 386 387 /* 388 * If the next hop is an IPv6 address, then the node identified 389 * by that address must be a neighbor of the sending host. 390 */ 391 ron = &opts->ip6po_nextroute; 392 if ((ron->ro_rt && 393 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 394 RTF_UP) || 395 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 396 &sin6_next->sin6_addr)) { 397 if (ron->ro_rt) { 398 RTFREE(ron->ro_rt); 399 ron->ro_rt = NULL; 400 } 401 *satosin6(&ron->ro_dst) = *sin6_next; 402 ron->ro_tableid = rtableid; 403 } 404 if (ron->ro_rt == NULL) { 405 rtalloc((struct route *)ron); /* multi path case? */ 406 if (ron->ro_rt == NULL || 407 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 408 if (ron->ro_rt) { 409 RTFREE(ron->ro_rt); 410 ron->ro_rt = NULL; 411 } 412 error = EHOSTUNREACH; 413 goto done; 414 } 415 } 416 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 417 RTFREE(ron->ro_rt); 418 ron->ro_rt = NULL; 419 error = EHOSTUNREACH; 420 goto done; 421 } 422 rt = ron->ro_rt; 423 ifp = rt->rt_ifp; 424 425 /* 426 * When cloning is required, try to allocate a route to the 427 * destination so that the caller can store path MTU 428 * information. 429 */ 430 goto done; 431 } 432 433 /* 434 * Use a cached route if it exists and is valid, else try to allocate 435 * a new one. Note that we should check the address family of the 436 * cached destination, in case of sharing the cache with IPv4. 437 */ 438 if (ro) { 439 if (ro->ro_rt && 440 (!(ro->ro_rt->rt_flags & RTF_UP) || 441 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 442 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 443 dst))) { 444 RTFREE(ro->ro_rt); 445 ro->ro_rt = (struct rtentry *)NULL; 446 } 447 if (ro->ro_rt == (struct rtentry *)NULL) { 448 struct sockaddr_in6 *sa6; 449 450 /* No route yet, so try to acquire one */ 451 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 452 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 453 *sa6 = *dstsock; 454 sa6->sin6_scope_id = 0; 455 ro->ro_tableid = rtableid; 456 rtalloc_mpath((struct route *)ro, NULL); 457 } 458 459 /* 460 * do not care about the result if we have the nexthop 461 * explicitly specified. 462 */ 463 if (opts && opts->ip6po_nexthop) 464 goto done; 465 466 if (ro->ro_rt) { 467 ifp = ro->ro_rt->rt_ifp; 468 469 if (ifp == NULL) { /* can this really happen? */ 470 RTFREE(ro->ro_rt); 471 ro->ro_rt = NULL; 472 } 473 } 474 if (ro->ro_rt == NULL) 475 error = EHOSTUNREACH; 476 rt = ro->ro_rt; 477 478 /* 479 * Check if the outgoing interface conflicts with 480 * the interface specified by ipi6_ifindex (if specified). 481 * Note that loopback interface is always okay. 482 * (this may happen when we are sending a packet to one of 483 * our own addresses.) 484 */ 485 if (opts && opts->ip6po_pktinfo && 486 opts->ip6po_pktinfo->ipi6_ifindex) { 487 if (!(ifp->if_flags & IFF_LOOPBACK) && 488 ifp->if_index != 489 opts->ip6po_pktinfo->ipi6_ifindex) { 490 error = EHOSTUNREACH; 491 goto done; 492 } 493 } 494 } 495 496 done: 497 if (ifp == NULL && rt == NULL) { 498 /* 499 * This can happen if the caller did not pass a cached route 500 * nor any other hints. We treat this case an error. 501 */ 502 error = EHOSTUNREACH; 503 } 504 if (error == EHOSTUNREACH) 505 ip6stat.ip6s_noroute++; 506 507 if (retifp != NULL) 508 *retifp = ifp; 509 if (retrt != NULL) 510 *retrt = rt; /* rt may be NULL */ 511 512 return (error); 513} 514 515int 516in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 517 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 518 u_int rtableid) 519{ 520 struct rtentry *rt = NULL; 521 int error; 522 523 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 524 &rt, 1, rtableid)) != 0) 525 return (error); 526 527 /* 528 * do not use a rejected or black hole route. 529 * XXX: this check should be done in the L2 output routine. 530 * However, if we skipped this check here, we'd see the following 531 * scenario: 532 * - install a rejected route for a scoped address prefix 533 * (like fe80::/10) 534 * - send a packet to a destination that matches the scoped prefix, 535 * with ambiguity about the scope zone. 536 * - pick the outgoing interface from the route, and disambiguate the 537 * scope zone with the interface. 538 * - ip6_output() would try to get another route with the "new" 539 * destination, which may be valid. 540 * - we'd see no error on output. 541 * Although this may not be very harmful, it should still be confusing. 542 * We thus reject the case here. 543 */ 544 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 545 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 546 547 /* 548 * Adjust the "outgoing" interface. If we're going to loop the packet 549 * back to ourselves, the ifp would be the loopback interface. 550 * However, we'd rather know the interface associated to the 551 * destination address (which should probably be one of our own 552 * addresses.) 553 */ 554 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 555 *retifp = rt->rt_ifa->ifa_ifp; 556 557 return (0); 558} 559 560int 561in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 562 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 563 struct rtentry **retrt, u_int rtableid) 564{ 565 566 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 567 rtableid)); 568} 569 570/* 571 * Default hop limit selection. The precedence is as follows: 572 * 1. Hoplimit value specified via ioctl. 573 * 2. (If the outgoing interface is detected) the current 574 * hop limit of the interface specified by router advertisement. 575 * 3. The system default hoplimit. 576*/ 577#define in6pcb inpcb 578#define in6p_hops inp_hops 579int 580in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 581{ 582 if (in6p && in6p->in6p_hops >= 0) 583 return (in6p->in6p_hops); 584 else if (ifp) 585 return (ND_IFINFO(ifp)->chlim); 586 else 587 return (ip6_defhlim); 588} 589#undef in6pcb 590#undef in6p_hops 591 592/* 593 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 594 * If the address scope of is link-local, embed the interface index in the 595 * address. The routine determines our precedence 596 * between advanced API scope/interface specification and basic API 597 * specification. 598 * 599 * this function should be nuked in the future, when we get rid of 600 * embedded scopeid thing. 601 * 602 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 603 * there can be multiple interfaces that belong to a particular scope zone 604 * (in specification, we have 1:N mapping between a scope zone and interfaces). 605 * we may want to change the function to return something other than ifp. 606 */ 607int 608in6_embedscope(in6, sin6, in6p, ifpp) 609 struct in6_addr *in6; 610 const struct sockaddr_in6 *sin6; 611 struct inpcb *in6p; 612#define in6p_outputopts inp_outputopts6 613#define in6p_moptions inp_moptions6 614 struct ifnet **ifpp; 615{ 616 struct ifnet *ifp = NULL; 617 u_int32_t scopeid; 618 619 *in6 = sin6->sin6_addr; 620 scopeid = sin6->sin6_scope_id; 621 if (ifpp) 622 *ifpp = NULL; 623 624 /* 625 * don't try to read sin6->sin6_addr beyond here, since the caller may 626 * ask us to overwrite existing sockaddr_in6 627 */ 628 629 if (IN6_IS_SCOPE_EMBED(in6)) { 630 struct in6_pktinfo *pi; 631 632 /* 633 * KAME assumption: link id == interface id 634 */ 635 636 if (in6p && in6p->in6p_outputopts && 637 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 638 pi->ipi6_ifindex) { 639 ifp = if_get(pi->ipi6_ifindex); 640 if (ifp == NULL) 641 return ENXIO; /* XXX EINVAL? */ 642 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 643 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 644 in6p->in6p_moptions && 645 in6p->in6p_moptions->im6o_multicast_ifp) { 646 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 647 in6->s6_addr16[1] = htons(ifp->if_index); 648 } else if (scopeid) { 649 ifp = if_get(scopeid); 650 if (ifp == NULL) 651 return ENXIO; /* XXX EINVAL? */ 652 /*XXX assignment to 16bit from 32bit variable */ 653 in6->s6_addr16[1] = htons(scopeid & 0xffff); 654 } 655 656 if (ifpp) 657 *ifpp = ifp; 658 } 659 660 return 0; 661} 662#undef in6p_outputopts 663#undef in6p_moptions 664 665/* 666 * generate standard sockaddr_in6 from embedded form. 667 * touches sin6_addr and sin6_scope_id only. 668 * 669 * this function should be nuked in the future, when we get rid of 670 * embedded scopeid thing. 671 */ 672int 673in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 674 struct ifnet *ifp) 675{ 676 u_int32_t scopeid; 677 678 sin6->sin6_addr = *in6; 679 680 /* 681 * don't try to read *in6 beyond here, since the caller may 682 * ask us to overwrite existing sockaddr_in6 683 */ 684 685 sin6->sin6_scope_id = 0; 686 if (IN6_IS_SCOPE_EMBED(in6)) { 687 /* 688 * KAME assumption: link id == interface id 689 */ 690 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 691 if (scopeid) { 692 /* sanity check */ 693 if (if_get(scopeid) == NULL) 694 return ENXIO; 695 if (ifp && ifp->if_index != scopeid) 696 return ENXIO; 697 sin6->sin6_addr.s6_addr16[1] = 0; 698 sin6->sin6_scope_id = scopeid; 699 } 700 } 701 702 return 0; 703} 704 705/* 706 * just clear the embedded scope identifer. 707 */ 708void 709in6_clearscope(struct in6_addr *addr) 710{ 711 if (IN6_IS_SCOPE_EMBED(addr)) 712 addr->s6_addr16[1] = 0; 713} 714