1 /* $OpenBSD: in6_src.c,v 1.48 2014/11/01 21:40:39 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/route.h> 76 77 #include <netinet/in.h> 78 #include <netinet/ip.h> 79 #include <netinet/in_pcb.h> 80 #include <netinet6/in6_var.h> 81 #include <netinet/ip6.h> 82 #include <netinet6/ip6_var.h> 83 #include <netinet6/nd6.h> 84 85 int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 86 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 87 int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 88 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 89 struct rtentry **, int, u_int); 90 91 /* 92 * Return an IPv6 address, which is the most appropriate for a given 93 * destination and user specified options. 94 * If necessary, this function lookups the routing table and returns 95 * an entry to the caller for later use. 96 */ 97 int 98 in6_selectsrc(struct in6_addr **in6src, struct sockaddr_in6 *dstsock, 99 struct ip6_pktopts *opts, struct ip6_moptions *mopts, 100 struct route_in6 *ro, struct in6_addr *laddr, u_int rtableid) 101 { 102 struct ifnet *ifp = NULL; 103 struct in6_addr *dst; 104 struct in6_ifaddr *ia6 = NULL; 105 struct in6_pktinfo *pi = NULL; 106 int error; 107 108 dst = &dstsock->sin6_addr; 109 110 /* 111 * If the source address is explicitly specified by the caller, 112 * check if the requested source address is indeed a unicast address 113 * assigned to the node, and can be used as the packet's source 114 * address. If everything is okay, use the address as source. 115 */ 116 if (opts && (pi = opts->ip6po_pktinfo) && 117 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 118 struct sockaddr_in6 sa6; 119 120 /* get the outgoing interface */ 121 error = in6_selectif(dstsock, opts, mopts, ro, &ifp, rtableid); 122 if (error) 123 return (error); 124 125 bzero(&sa6, sizeof(sa6)); 126 sa6.sin6_family = AF_INET6; 127 sa6.sin6_len = sizeof(sa6); 128 sa6.sin6_addr = pi->ipi6_addr; 129 130 if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr)) 131 sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 132 133 ia6 = ifatoia6(ifa_ifwithaddr(sin6tosa(&sa6), rtableid)); 134 if (ia6 == NULL || 135 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) 136 return (EADDRNOTAVAIL); 137 138 pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */ 139 140 *in6src = &pi->ipi6_addr; 141 return (0); 142 } 143 144 /* 145 * If the source address is not specified but the socket(if any) 146 * is already bound, use the bound address. 147 */ 148 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { 149 *in6src = laddr; 150 return (0); 151 } 152 153 /* 154 * If the caller doesn't specify the source address but 155 * the outgoing interface, use an address associated with 156 * the interface. 157 */ 158 if (pi && pi->ipi6_ifindex) { 159 ifp = if_get(pi->ipi6_ifindex); 160 if (ifp == NULL) 161 return (ENXIO); /* XXX: better error? */ 162 163 ia6 = in6_ifawithscope(ifp, dst, rtableid); 164 if (ia6 == NULL) 165 return (EADDRNOTAVAIL); 166 167 *in6src = &ia6->ia_addr.sin6_addr; 168 return (0); 169 } 170 171 /* 172 * If the destination address is a link-local unicast address or 173 * a link/interface-local multicast address, and if the outgoing 174 * interface is specified by the sin6_scope_id filed, use an address 175 * associated with the interface. 176 * XXX: We're now trying to define more specific semantics of 177 * sin6_scope_id field, so this part will be rewritten in 178 * the near future. 179 */ 180 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) || 181 IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) { 182 ifp = if_get(dstsock->sin6_scope_id); 183 if (ifp == NULL) 184 return (ENXIO); /* XXX: better error? */ 185 186 ia6 = in6_ifawithscope(ifp, dst, rtableid); 187 if (ia6 == NULL) 188 return (EADDRNOTAVAIL); 189 190 *in6src = &ia6->ia_addr.sin6_addr; 191 return (0); 192 } 193 194 /* 195 * If the destination address is a multicast address and 196 * the outgoing interface for the address is specified 197 * by the caller, use an address associated with the interface. 198 * Even if the outgoing interface is not specified, we also 199 * choose a loopback interface as the outgoing interface. 200 */ 201 if (IN6_IS_ADDR_MULTICAST(dst)) { 202 ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 203 204 if (!ifp && dstsock->sin6_scope_id) 205 ifp = if_get(htons(dstsock->sin6_scope_id)); 206 207 if (ifp) { 208 ia6 = in6_ifawithscope(ifp, dst, rtableid); 209 if (ia6 == NULL) 210 return (EADDRNOTAVAIL); 211 212 *in6src = &ia6->ia_addr.sin6_addr; 213 return (0); 214 } 215 } 216 217 /* 218 * If the next hop address for the packet is specified 219 * by caller, use an address associated with the route 220 * to the next hop. 221 */ 222 { 223 struct sockaddr_in6 *sin6_next; 224 struct rtentry *rt; 225 226 if (opts && opts->ip6po_nexthop) { 227 sin6_next = satosin6(opts->ip6po_nexthop); 228 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL, 229 rtableid); 230 if (rt) { 231 ia6 = in6_ifawithscope(rt->rt_ifp, dst, 232 rtableid); 233 if (ia6 == 0) 234 ia6 = ifatoia6(rt->rt_ifa); 235 } 236 if (ia6 == NULL) 237 return (EADDRNOTAVAIL); 238 239 *in6src = &ia6->ia_addr.sin6_addr; 240 return (0); 241 } 242 } 243 244 /* 245 * If route is known or can be allocated now, 246 * our src addr is taken from the i/f, else punt. 247 */ 248 if (ro) { 249 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 250 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 251 rtfree(ro->ro_rt); 252 ro->ro_rt = NULL; 253 } 254 if (ro->ro_rt == (struct rtentry *)0 || 255 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 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 == 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 } 297 298 int 299 selectroute(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 /* 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 (ro->ro_rt && 422 (!(ro->ro_rt->rt_flags & RTF_UP) || 423 sin6tosa(&ro->ro_dst)->sa_family != AF_INET6 || 424 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, dst))) { 425 rtfree(ro->ro_rt); 426 ro->ro_rt = NULL; 427 } 428 if (ro->ro_rt == NULL) { 429 struct sockaddr_in6 *sa6; 430 431 /* No route yet, so try to acquire one */ 432 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 433 ro->ro_tableid = rtableid; 434 sa6 = &ro->ro_dst; 435 *sa6 = *dstsock; 436 sa6->sin6_scope_id = 0; 437 ro->ro_tableid = rtableid; 438 ro->ro_rt = rtalloc_mpath(sin6tosa(&ro->ro_dst), 439 NULL, ro->ro_tableid); 440 } 441 442 /* 443 * do not care about the result if we have the nexthop 444 * explicitly specified. 445 */ 446 if (opts && opts->ip6po_nexthop) 447 goto done; 448 449 if (ro->ro_rt) { 450 ifp = ro->ro_rt->rt_ifp; 451 452 if (ifp == NULL) { /* can this really happen? */ 453 rtfree(ro->ro_rt); 454 ro->ro_rt = NULL; 455 } 456 } 457 if (ro->ro_rt == NULL) 458 error = EHOSTUNREACH; 459 rt = ro->ro_rt; 460 461 /* 462 * Check if the outgoing interface conflicts with 463 * the interface specified by ipi6_ifindex (if specified). 464 * Note that loopback interface is always okay. 465 * (this may happen when we are sending a packet to one of 466 * our own addresses.) 467 */ 468 if (opts && opts->ip6po_pktinfo && 469 opts->ip6po_pktinfo->ipi6_ifindex) { 470 if (!(ifp->if_flags & IFF_LOOPBACK) && 471 ifp->if_index != 472 opts->ip6po_pktinfo->ipi6_ifindex) { 473 error = EHOSTUNREACH; 474 goto done; 475 } 476 } 477 } 478 479 done: 480 if (ifp == NULL && rt == NULL) { 481 /* 482 * This can happen if the caller did not pass a cached route 483 * nor any other hints. We treat this case an error. 484 */ 485 error = EHOSTUNREACH; 486 } 487 if (error == EHOSTUNREACH) 488 ip6stat.ip6s_noroute++; 489 490 if (retifp != NULL) 491 *retifp = ifp; 492 if (retrt != NULL) 493 *retrt = rt; /* rt may be NULL */ 494 495 return (error); 496 } 497 498 int 499 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 500 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 501 u_int rtableid) 502 { 503 struct rtentry *rt = NULL; 504 int error; 505 506 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 507 &rt, 1, rtableid)) != 0) 508 return (error); 509 510 /* 511 * do not use a rejected or black hole route. 512 * XXX: this check should be done in the L2 output routine. 513 * However, if we skipped this check here, we'd see the following 514 * scenario: 515 * - install a rejected route for a scoped address prefix 516 * (like fe80::/10) 517 * - send a packet to a destination that matches the scoped prefix, 518 * with ambiguity about the scope zone. 519 * - pick the outgoing interface from the route, and disambiguate the 520 * scope zone with the interface. 521 * - ip6_output() would try to get another route with the "new" 522 * destination, which may be valid. 523 * - we'd see no error on output. 524 * Although this may not be very harmful, it should still be confusing. 525 * We thus reject the case here. 526 */ 527 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 528 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 529 530 /* 531 * Adjust the "outgoing" interface. If we're going to loop the packet 532 * back to ourselves, the ifp would be the loopback interface. 533 * However, we'd rather know the interface associated to the 534 * destination address (which should probably be one of our own 535 * addresses.) 536 */ 537 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 538 *retifp = rt->rt_ifa->ifa_ifp; 539 540 return (0); 541 } 542 543 int 544 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 545 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 546 struct rtentry **retrt, u_int rtableid) 547 { 548 549 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 550 rtableid)); 551 } 552 553 /* 554 * Default hop limit selection. The precedence is as follows: 555 * 1. Hoplimit value specified via ioctl. 556 * 2. (If the outgoing interface is detected) the current 557 * hop limit of the interface specified by router advertisement. 558 * 3. The system default hoplimit. 559 */ 560 int 561 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 562 { 563 if (in6p && in6p->inp_hops >= 0) 564 return (in6p->inp_hops); 565 else if (ifp) 566 return (ND_IFINFO(ifp)->chlim); 567 else 568 return (ip6_defhlim); 569 } 570 571 /* 572 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 573 * If the address scope of is link-local, embed the interface index in the 574 * address. The routine determines our precedence 575 * between advanced API scope/interface specification and basic API 576 * specification. 577 * 578 * this function should be nuked in the future, when we get rid of 579 * embedded scopeid thing. 580 * 581 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 582 * there can be multiple interfaces that belong to a particular scope zone 583 * (in specification, we have 1:N mapping between a scope zone and interfaces). 584 * we may want to change the function to return something other than ifp. 585 */ 586 int 587 in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, 588 struct inpcb *in6p, struct ifnet **ifpp) 589 { 590 struct ifnet *ifp = NULL; 591 u_int32_t scopeid; 592 593 *in6 = sin6->sin6_addr; 594 scopeid = sin6->sin6_scope_id; 595 if (ifpp) 596 *ifpp = NULL; 597 598 /* 599 * don't try to read sin6->sin6_addr beyond here, since the caller may 600 * ask us to overwrite existing sockaddr_in6 601 */ 602 603 if (IN6_IS_SCOPE_EMBED(in6)) { 604 struct in6_pktinfo *pi; 605 606 /* 607 * KAME assumption: link id == interface id 608 */ 609 610 if (in6p && in6p->inp_outputopts6 && 611 (pi = in6p->inp_outputopts6->ip6po_pktinfo) && 612 pi->ipi6_ifindex) { 613 ifp = if_get(pi->ipi6_ifindex); 614 if (ifp == NULL) 615 return ENXIO; /* XXX EINVAL? */ 616 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 617 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 618 in6p->inp_moptions6 && 619 in6p->inp_moptions6->im6o_multicast_ifp) { 620 ifp = in6p->inp_moptions6->im6o_multicast_ifp; 621 in6->s6_addr16[1] = htons(ifp->if_index); 622 } else if (scopeid) { 623 ifp = if_get(scopeid); 624 if (ifp == NULL) 625 return ENXIO; /* XXX EINVAL? */ 626 /*XXX assignment to 16bit from 32bit variable */ 627 in6->s6_addr16[1] = htons(scopeid & 0xffff); 628 } 629 630 if (ifpp) 631 *ifpp = ifp; 632 } 633 634 return 0; 635 } 636 637 /* 638 * generate standard sockaddr_in6 from embedded form. 639 * touches sin6_addr and sin6_scope_id only. 640 * 641 * this function should be nuked in the future, when we get rid of 642 * embedded scopeid thing. 643 */ 644 int 645 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 646 struct ifnet *ifp) 647 { 648 u_int32_t scopeid; 649 650 sin6->sin6_addr = *in6; 651 652 /* 653 * don't try to read *in6 beyond here, since the caller may 654 * ask us to overwrite existing sockaddr_in6 655 */ 656 657 sin6->sin6_scope_id = 0; 658 if (IN6_IS_SCOPE_EMBED(in6)) { 659 /* 660 * KAME assumption: link id == interface id 661 */ 662 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 663 if (scopeid) { 664 /* sanity check */ 665 if (if_get(scopeid) == NULL) 666 return ENXIO; 667 if (ifp && ifp->if_index != scopeid) 668 return ENXIO; 669 sin6->sin6_addr.s6_addr16[1] = 0; 670 sin6->sin6_scope_id = scopeid; 671 } 672 } 673 674 return 0; 675 } 676 677 /* 678 * just clear the embedded scope identifer. 679 */ 680 void 681 in6_clearscope(struct in6_addr *addr) 682 { 683 if (IN6_IS_SCOPE_EMBED(addr)) 684 addr->s6_addr16[1] = 0; 685 } 686