in6_src.c revision 1.26
1/* $OpenBSD: in6_src.c,v 1.26 2011/08/07 18:49:50 mikeb 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 **); 91int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 92 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 93 struct rtentry **, 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) 105{ 106 struct in6_addr *dst; 107 struct in6_ifaddr *ia6 = 0; 108 struct in6_pktinfo *pi = NULL; 109 110 dst = &dstsock->sin6_addr; 111 *errorp = 0; 112 113 /* 114 * If the source address is explicitly specified by the caller, 115 * check if the requested source address is indeed a unicast address 116 * assigned to the node, and can be used as the packet's source 117 * address. If everything is okay, use the address as source. 118 */ 119 if (opts && (pi = opts->ip6po_pktinfo) && 120 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 121 struct ifnet *ifp = NULL; 122 struct sockaddr_in6 sa6; 123 124 /* get the outgoing interface */ 125 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, 126 &ifp)) != 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 = (struct in6_ifaddr *) 138 ifa_ifwithaddr((struct sockaddr *)&sa6, 0); 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 /* XXX boundary check is assumed to be already done. */ 164 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 165 dst); 166 if (ia6 == 0) { 167 *errorp = EADDRNOTAVAIL; 168 return (0); 169 } 170 return (&satosin6(&ia6->ia_addr)->sin6_addr); 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 /* 185 * I'm not sure if boundary check for scope_id is done 186 * somewhere... 187 */ 188 if (dstsock->sin6_scope_id < 0 || 189 if_indexlim <= dstsock->sin6_scope_id || 190 !ifindex2ifnet[dstsock->sin6_scope_id]) { 191 *errorp = ENXIO; /* XXX: better error? */ 192 return (0); 193 } 194 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 195 dst); 196 if (ia6 == 0) { 197 *errorp = EADDRNOTAVAIL; 198 return (0); 199 } 200 return (&satosin6(&ia6->ia_addr)->sin6_addr); 201 } 202 203 /* 204 * If the destination address is a multicast address and 205 * the outgoing interface for the address is specified 206 * by the caller, use an address associated with the interface. 207 * Even if the outgoing interface is not specified, we also 208 * choose a loopback interface as the outgoing interface. 209 */ 210 if (IN6_IS_ADDR_MULTICAST(dst)) { 211 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 212 213 if (!ifp && dstsock->sin6_scope_id) 214 ifp = ifindex2ifnet[htons(dstsock->sin6_scope_id)]; 215 216 if (ifp) { 217 ia6 = in6_ifawithscope(ifp, dst); 218 if (ia6 == 0) { 219 *errorp = EADDRNOTAVAIL; 220 return (0); 221 } 222 return (&satosin6(&ia6->ia_addr)->sin6_addr); 223 } 224 } 225 226 /* 227 * If the next hop address for the packet is specified 228 * by caller, use an address associated with the route 229 * to the next hop. 230 */ 231 { 232 struct sockaddr_in6 *sin6_next; 233 struct rtentry *rt; 234 235 if (opts && opts->ip6po_nexthop) { 236 sin6_next = satosin6(opts->ip6po_nexthop); 237 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 238 if (rt) { 239 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 240 if (ia6 == 0) 241 ia6 = ifatoia6(rt->rt_ifa); 242 } 243 if (ia6 == 0) { 244 *errorp = EADDRNOTAVAIL; 245 return (0); 246 } 247 return (&satosin6(&ia6->ia_addr)->sin6_addr); 248 } 249 } 250 251 /* 252 * If route is known or can be allocated now, 253 * our src addr is taken from the i/f, else punt. 254 */ 255 if (ro) { 256 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 257 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 258 RTFREE(ro->ro_rt); 259 ro->ro_rt = (struct rtentry *)0; 260 } 261 if (ro->ro_rt == (struct rtentry *)0 || 262 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 263 struct sockaddr_in6 *sa6; 264 265 /* No route yet, so try to acquire one */ 266 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 267 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 268 sa6->sin6_family = AF_INET6; 269 sa6->sin6_len = sizeof(struct sockaddr_in6); 270 sa6->sin6_addr = *dst; 271 sa6->sin6_scope_id = dstsock->sin6_scope_id; 272 if (IN6_IS_ADDR_MULTICAST(dst)) { 273 rtalloc((struct route *)ro); 274 } else { 275 rtalloc_mpath((struct route *)ro, NULL); 276 } 277 } 278 279 /* 280 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 281 * the address. But we don't know why it does so. 282 * It is necessary to ensure the scope even for lo0 283 * so doesn't check out IFF_LOOPBACK. 284 */ 285 286 if (ro->ro_rt) { 287 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 288 if (ia6 == 0) /* xxx scope error ?*/ 289 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 290 } 291#if 0 292 /* 293 * xxx The followings are necessary? (kazu) 294 * I don't think so. 295 * It's for SO_DONTROUTE option in IPv4.(jinmei) 296 */ 297 if (ia6 == 0) { 298 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 299 300 sin6->sin6_addr = *dst; 301 302 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 303 if (ia6 == 0) 304 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 305 if (ia6 == 0) 306 return (0); 307 return (&satosin6(&ia6->ia_addr)->sin6_addr); 308 } 309#endif /* 0 */ 310 if (ia6 == 0) { 311 *errorp = EHOSTUNREACH; /* no route */ 312 return (0); 313 } 314 return (&satosin6(&ia6->ia_addr)->sin6_addr); 315 } 316 317 *errorp = EADDRNOTAVAIL; 318 return (0); 319} 320 321int 322selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 323 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 324 struct rtentry **retrt, int norouteok) 325{ 326 int error = 0; 327 struct ifnet *ifp = NULL; 328 struct rtentry *rt = NULL; 329 struct sockaddr_in6 *sin6_next; 330 struct in6_pktinfo *pi = NULL; 331 struct in6_addr *dst; 332 333 dst = &dstsock->sin6_addr; 334 335#if 0 336 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 337 dstsock->sin6_addr.s6_addr32[1] == 0 && 338 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 339 printf("in6_selectroute: strange destination %s\n", 340 ip6_sprintf(&dstsock->sin6_addr)); 341 } else { 342 printf("in6_selectroute: destination = %s%%%d\n", 343 ip6_sprintf(&dstsock->sin6_addr), 344 dstsock->sin6_scope_id); /* for debug */ 345 } 346#endif 347 348 /* If the caller specify the outgoing interface explicitly, use it. */ 349 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 350 /* XXX boundary check is assumed to be already done. */ 351 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 352 if (ifp != NULL && 353 (norouteok || retrt == NULL || 354 IN6_IS_ADDR_MULTICAST(dst))) { 355 /* 356 * we do not have to check or get the route for 357 * multicast. 358 */ 359 goto done; 360 } else 361 goto getroute; 362 } 363 364 /* 365 * If the destination address is a multicast address and the outgoing 366 * interface for the address is specified by the caller, use it. 367 */ 368 if (IN6_IS_ADDR_MULTICAST(dst) && 369 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 370 goto done; /* we do not need a route for multicast. */ 371 } 372 373 getroute: 374 /* 375 * If the next hop address for the packet is specified by the caller, 376 * use it as the gateway. 377 */ 378 if (opts && opts->ip6po_nexthop) { 379 struct route_in6 *ron; 380 381 sin6_next = satosin6(opts->ip6po_nexthop); 382 383 /* at this moment, we only support AF_INET6 next hops */ 384 if (sin6_next->sin6_family != AF_INET6) { 385 error = EAFNOSUPPORT; /* or should we proceed? */ 386 goto done; 387 } 388 389 /* 390 * If the next hop is an IPv6 address, then the node identified 391 * by that address must be a neighbor of the sending host. 392 */ 393 ron = &opts->ip6po_nextroute; 394 if ((ron->ro_rt && 395 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 396 RTF_UP) || 397 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 398 &sin6_next->sin6_addr)) { 399 if (ron->ro_rt) { 400 RTFREE(ron->ro_rt); 401 ron->ro_rt = NULL; 402 } 403 *satosin6(&ron->ro_dst) = *sin6_next; 404 ron->ro_tableid = 0; /* XXX rtableid */ 405 } 406 if (ron->ro_rt == NULL) { 407 rtalloc((struct route *)ron); /* multi path case? */ 408 if (ron->ro_rt == NULL || 409 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 410 if (ron->ro_rt) { 411 RTFREE(ron->ro_rt); 412 ron->ro_rt = NULL; 413 } 414 error = EHOSTUNREACH; 415 goto done; 416 } 417 } 418 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 419 RTFREE(ron->ro_rt); 420 ron->ro_rt = NULL; 421 error = EHOSTUNREACH; 422 goto done; 423 } 424 rt = ron->ro_rt; 425 ifp = rt->rt_ifp; 426 427 /* 428 * When cloning is required, try to allocate a route to the 429 * destination so that the caller can store path MTU 430 * information. 431 */ 432 goto done; 433 } 434 435 /* 436 * Use a cached route if it exists and is valid, else try to allocate 437 * a new one. Note that we should check the address family of the 438 * cached destination, in case of sharing the cache with IPv4. 439 */ 440 if (ro) { 441 if (ro->ro_rt && 442 (!(ro->ro_rt->rt_flags & RTF_UP) || 443 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 444 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 445 dst))) { 446 RTFREE(ro->ro_rt); 447 ro->ro_rt = (struct rtentry *)NULL; 448 } 449 if (ro->ro_rt == (struct rtentry *)NULL) { 450 struct sockaddr_in6 *sa6; 451 452 /* No route yet, so try to acquire one */ 453 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 454 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 455 *sa6 = *dstsock; 456 sa6->sin6_scope_id = 0; 457 rtalloc_mpath((struct route *)ro, NULL); 458 } 459 460 /* 461 * do not care about the result if we have the nexthop 462 * explicitly specified. 463 */ 464 if (opts && opts->ip6po_nexthop) 465 goto done; 466 467 if (ro->ro_rt) { 468 ifp = ro->ro_rt->rt_ifp; 469 470 if (ifp == NULL) { /* can this really happen? */ 471 RTFREE(ro->ro_rt); 472 ro->ro_rt = NULL; 473 } 474 } 475 if (ro->ro_rt == NULL) 476 error = EHOSTUNREACH; 477 rt = ro->ro_rt; 478 479 /* 480 * Check if the outgoing interface conflicts with 481 * the interface specified by ipi6_ifindex (if specified). 482 * Note that loopback interface is always okay. 483 * (this may happen when we are sending a packet to one of 484 * our own addresses.) 485 */ 486 if (opts && opts->ip6po_pktinfo && 487 opts->ip6po_pktinfo->ipi6_ifindex) { 488 if (!(ifp->if_flags & IFF_LOOPBACK) && 489 ifp->if_index != 490 opts->ip6po_pktinfo->ipi6_ifindex) { 491 error = EHOSTUNREACH; 492 goto done; 493 } 494 } 495 } 496 497 done: 498 if (ifp == NULL && rt == NULL) { 499 /* 500 * This can happen if the caller did not pass a cached route 501 * nor any other hints. We treat this case an error. 502 */ 503 error = EHOSTUNREACH; 504 } 505 if (error == EHOSTUNREACH) 506 ip6stat.ip6s_noroute++; 507 508 if (retifp != NULL) 509 *retifp = ifp; 510 if (retrt != NULL) 511 *retrt = rt; /* rt may be NULL */ 512 513 return (error); 514} 515 516int 517in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 518 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp) 519{ 520 struct rtentry *rt = NULL; 521 int error; 522 523 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 524 &rt, 1)) != 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) 564{ 565 566 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0)); 567} 568 569/* 570 * Default hop limit selection. The precedence is as follows: 571 * 1. Hoplimit value specified via ioctl. 572 * 2. (If the outgoing interface is detected) the current 573 * hop limit of the interface specified by router advertisement. 574 * 3. The system default hoplimit. 575*/ 576#define in6pcb inpcb 577#define in6p_hops inp_hops 578int 579in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 580{ 581 if (in6p && in6p->in6p_hops >= 0) 582 return (in6p->in6p_hops); 583 else if (ifp) 584 return (ND_IFINFO(ifp)->chlim); 585 else 586 return (ip6_defhlim); 587} 588#undef in6pcb 589#undef in6p_hops 590 591/* 592 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 593 * If the address scope of is link-local, embed the interface index in the 594 * address. The routine determines our precedence 595 * between advanced API scope/interface specification and basic API 596 * specification. 597 * 598 * this function should be nuked in the future, when we get rid of 599 * embedded scopeid thing. 600 * 601 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 602 * there can be multiple interfaces that belong to a particular scope zone 603 * (in specification, we have 1:N mapping between a scope zone and interfaces). 604 * we may want to change the function to return something other than ifp. 605 */ 606int 607in6_embedscope(in6, sin6, in6p, ifpp) 608 struct in6_addr *in6; 609 const struct sockaddr_in6 *sin6; 610 struct inpcb *in6p; 611#define in6p_outputopts inp_outputopts6 612#define in6p_moptions inp_moptions6 613 struct ifnet **ifpp; 614{ 615 struct ifnet *ifp = NULL; 616 u_int32_t scopeid; 617 618 *in6 = sin6->sin6_addr; 619 scopeid = sin6->sin6_scope_id; 620 if (ifpp) 621 *ifpp = NULL; 622 623 /* 624 * don't try to read sin6->sin6_addr beyond here, since the caller may 625 * ask us to overwrite existing sockaddr_in6 626 */ 627 628 if (IN6_IS_SCOPE_EMBED(in6)) { 629 struct in6_pktinfo *pi; 630 631 /* 632 * KAME assumption: link id == interface id 633 */ 634 635 if (in6p && in6p->in6p_outputopts && 636 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 637 pi->ipi6_ifindex) { 638 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 639 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 640 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 641 in6p->in6p_moptions && 642 in6p->in6p_moptions->im6o_multicast_ifp) { 643 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 644 in6->s6_addr16[1] = htons(ifp->if_index); 645 } else if (scopeid) { 646 /* boundary check */ 647 if (scopeid < 0 || if_indexlim <= scopeid || 648 !ifindex2ifnet[scopeid]) 649 return ENXIO; /* XXX EINVAL? */ 650 ifp = ifindex2ifnet[scopeid]; 651 /*XXX assignment to 16bit from 32bit variable */ 652 in6->s6_addr16[1] = htons(scopeid & 0xffff); 653 } 654 655 if (ifpp) 656 *ifpp = ifp; 657 } 658 659 return 0; 660} 661#undef in6p_outputopts 662#undef in6p_moptions 663 664/* 665 * generate standard sockaddr_in6 from embedded form. 666 * touches sin6_addr and sin6_scope_id only. 667 * 668 * this function should be nuked in the future, when we get rid of 669 * embedded scopeid thing. 670 */ 671int 672in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 673 struct ifnet *ifp) 674{ 675 u_int32_t scopeid; 676 677 sin6->sin6_addr = *in6; 678 679 /* 680 * don't try to read *in6 beyond here, since the caller may 681 * ask us to overwrite existing sockaddr_in6 682 */ 683 684 sin6->sin6_scope_id = 0; 685 if (IN6_IS_SCOPE_EMBED(in6)) { 686 /* 687 * KAME assumption: link id == interface id 688 */ 689 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 690 if (scopeid) { 691 /* sanity check */ 692 if (scopeid < 0 || if_indexlim <= scopeid || 693 !ifindex2ifnet[scopeid]) 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