1 /* $OpenBSD: in6_src.c,v 1.27 2011/11/24 17:39:55 sperreault 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 89 int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 90 struct ip6_moptions *, struct route_in6 *, struct ifnet **, u_int); 91 int 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 */ 101 struct in6_addr * 102 in6_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 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, 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 = (struct in6_ifaddr *) 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 /* XXX boundary check is assumed to be already done. */ 164 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 165 dst, rtableid); 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, rtableid); 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, rtableid); 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 rtableid); 241 if (ia6 == 0) 242 ia6 = ifatoia6(rt->rt_ifa); 243 } 244 if (ia6 == 0) { 245 *errorp = EADDRNOTAVAIL; 246 return (0); 247 } 248 return (&satosin6(&ia6->ia_addr)->sin6_addr); 249 } 250 } 251 252 /* 253 * If route is known or can be allocated now, 254 * our src addr is taken from the i/f, else punt. 255 */ 256 if (ro) { 257 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 258 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 259 RTFREE(ro->ro_rt); 260 ro->ro_rt = (struct rtentry *)0; 261 } 262 if (ro->ro_rt == (struct rtentry *)0 || 263 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 264 struct sockaddr_in6 *sa6; 265 266 /* No route yet, so try to acquire one */ 267 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 268 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 269 sa6->sin6_family = AF_INET6; 270 sa6->sin6_len = sizeof(struct sockaddr_in6); 271 sa6->sin6_addr = *dst; 272 sa6->sin6_scope_id = dstsock->sin6_scope_id; 273 if (IN6_IS_ADDR_MULTICAST(dst)) { 274 rtalloc((struct route *)ro); 275 } else { 276 rtalloc_mpath((struct route *)ro, NULL); 277 } 278 } 279 280 /* 281 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 282 * the address. But we don't know why it does so. 283 * It is necessary to ensure the scope even for lo0 284 * so doesn't check out IFF_LOOPBACK. 285 */ 286 287 if (ro->ro_rt) { 288 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, 289 rtableid); 290 if (ia6 == 0) /* xxx scope error ?*/ 291 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 292 } 293 #if 0 294 /* 295 * xxx The followings are necessary? (kazu) 296 * I don't think so. 297 * It's for SO_DONTROUTE option in IPv4.(jinmei) 298 */ 299 if (ia6 == 0) { 300 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 301 302 sin6->sin6_addr = *dst; 303 304 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 305 if (ia6 == 0) 306 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 307 if (ia6 == 0) 308 return (0); 309 return (&satosin6(&ia6->ia_addr)->sin6_addr); 310 } 311 #endif /* 0 */ 312 if (ia6 == 0) { 313 *errorp = EHOSTUNREACH; /* no route */ 314 return (0); 315 } 316 return (&satosin6(&ia6->ia_addr)->sin6_addr); 317 } 318 319 *errorp = EADDRNOTAVAIL; 320 return (0); 321 } 322 323 int 324 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 325 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 326 struct rtentry **retrt, int norouteok, u_int rtableid) 327 { 328 int error = 0; 329 struct ifnet *ifp = NULL; 330 struct rtentry *rt = NULL; 331 struct sockaddr_in6 *sin6_next; 332 struct in6_pktinfo *pi = NULL; 333 struct in6_addr *dst; 334 335 dst = &dstsock->sin6_addr; 336 337 #if 0 338 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 339 dstsock->sin6_addr.s6_addr32[1] == 0 && 340 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 341 printf("in6_selectroute: strange destination %s\n", 342 ip6_sprintf(&dstsock->sin6_addr)); 343 } else { 344 printf("in6_selectroute: destination = %s%%%d\n", 345 ip6_sprintf(&dstsock->sin6_addr), 346 dstsock->sin6_scope_id); /* for debug */ 347 } 348 #endif 349 350 /* If the caller specify the outgoing interface explicitly, use it. */ 351 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 352 /* XXX boundary check is assumed to be already done. */ 353 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 354 if (ifp != NULL && 355 (norouteok || retrt == NULL || 356 IN6_IS_ADDR_MULTICAST(dst))) { 357 /* 358 * we do not have to check or get the route for 359 * multicast. 360 */ 361 goto done; 362 } else 363 goto getroute; 364 } 365 366 /* 367 * If the destination address is a multicast address and the outgoing 368 * interface for the address is specified by the caller, use it. 369 */ 370 if (IN6_IS_ADDR_MULTICAST(dst) && 371 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 372 goto done; /* we do not need a route for multicast. */ 373 } 374 375 getroute: 376 /* 377 * If the next hop address for the packet is specified by the caller, 378 * use it as the gateway. 379 */ 380 if (opts && opts->ip6po_nexthop) { 381 struct route_in6 *ron; 382 383 sin6_next = satosin6(opts->ip6po_nexthop); 384 385 /* at this moment, we only support AF_INET6 next hops */ 386 if (sin6_next->sin6_family != AF_INET6) { 387 error = EAFNOSUPPORT; /* or should we proceed? */ 388 goto done; 389 } 390 391 /* 392 * If the next hop is an IPv6 address, then the node identified 393 * by that address must be a neighbor of the sending host. 394 */ 395 ron = &opts->ip6po_nextroute; 396 if ((ron->ro_rt && 397 (ron->ro_rt->rt_flags & (RTF_UP | RTF_GATEWAY)) != 398 RTF_UP) || 399 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 400 &sin6_next->sin6_addr)) { 401 if (ron->ro_rt) { 402 RTFREE(ron->ro_rt); 403 ron->ro_rt = NULL; 404 } 405 *satosin6(&ron->ro_dst) = *sin6_next; 406 ron->ro_tableid = rtableid; 407 } 408 if (ron->ro_rt == NULL) { 409 rtalloc((struct route *)ron); /* multi path case? */ 410 if (ron->ro_rt == NULL || 411 (ron->ro_rt->rt_flags & RTF_GATEWAY)) { 412 if (ron->ro_rt) { 413 RTFREE(ron->ro_rt); 414 ron->ro_rt = NULL; 415 } 416 error = EHOSTUNREACH; 417 goto done; 418 } 419 } 420 if (!nd6_is_addr_neighbor(sin6_next, ron->ro_rt->rt_ifp)) { 421 RTFREE(ron->ro_rt); 422 ron->ro_rt = NULL; 423 error = EHOSTUNREACH; 424 goto done; 425 } 426 rt = ron->ro_rt; 427 ifp = rt->rt_ifp; 428 429 /* 430 * When cloning is required, try to allocate a route to the 431 * destination so that the caller can store path MTU 432 * information. 433 */ 434 goto done; 435 } 436 437 /* 438 * Use a cached route if it exists and is valid, else try to allocate 439 * a new one. Note that we should check the address family of the 440 * cached destination, in case of sharing the cache with IPv4. 441 */ 442 if (ro) { 443 if (ro->ro_rt && 444 (!(ro->ro_rt->rt_flags & RTF_UP) || 445 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 446 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 447 dst))) { 448 RTFREE(ro->ro_rt); 449 ro->ro_rt = (struct rtentry *)NULL; 450 } 451 if (ro->ro_rt == (struct rtentry *)NULL) { 452 struct sockaddr_in6 *sa6; 453 454 /* No route yet, so try to acquire one */ 455 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 456 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 457 *sa6 = *dstsock; 458 sa6->sin6_scope_id = 0; 459 ro->ro_tableid = rtableid; 460 rtalloc_mpath((struct route *)ro, NULL); 461 } 462 463 /* 464 * do not care about the result if we have the nexthop 465 * explicitly specified. 466 */ 467 if (opts && opts->ip6po_nexthop) 468 goto done; 469 470 if (ro->ro_rt) { 471 ifp = ro->ro_rt->rt_ifp; 472 473 if (ifp == NULL) { /* can this really happen? */ 474 RTFREE(ro->ro_rt); 475 ro->ro_rt = NULL; 476 } 477 } 478 if (ro->ro_rt == NULL) 479 error = EHOSTUNREACH; 480 rt = ro->ro_rt; 481 482 /* 483 * Check if the outgoing interface conflicts with 484 * the interface specified by ipi6_ifindex (if specified). 485 * Note that loopback interface is always okay. 486 * (this may happen when we are sending a packet to one of 487 * our own addresses.) 488 */ 489 if (opts && opts->ip6po_pktinfo && 490 opts->ip6po_pktinfo->ipi6_ifindex) { 491 if (!(ifp->if_flags & IFF_LOOPBACK) && 492 ifp->if_index != 493 opts->ip6po_pktinfo->ipi6_ifindex) { 494 error = EHOSTUNREACH; 495 goto done; 496 } 497 } 498 } 499 500 done: 501 if (ifp == NULL && rt == NULL) { 502 /* 503 * This can happen if the caller did not pass a cached route 504 * nor any other hints. We treat this case an error. 505 */ 506 error = EHOSTUNREACH; 507 } 508 if (error == EHOSTUNREACH) 509 ip6stat.ip6s_noroute++; 510 511 if (retifp != NULL) 512 *retifp = ifp; 513 if (retrt != NULL) 514 *retrt = rt; /* rt may be NULL */ 515 516 return (error); 517 } 518 519 int 520 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 521 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 522 u_int rtableid) 523 { 524 struct rtentry *rt = NULL; 525 int error; 526 527 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 528 &rt, 1, rtableid)) != 0) 529 return (error); 530 531 /* 532 * do not use a rejected or black hole route. 533 * XXX: this check should be done in the L2 output routine. 534 * However, if we skipped this check here, we'd see the following 535 * scenario: 536 * - install a rejected route for a scoped address prefix 537 * (like fe80::/10) 538 * - send a packet to a destination that matches the scoped prefix, 539 * with ambiguity about the scope zone. 540 * - pick the outgoing interface from the route, and disambiguate the 541 * scope zone with the interface. 542 * - ip6_output() would try to get another route with the "new" 543 * destination, which may be valid. 544 * - we'd see no error on output. 545 * Although this may not be very harmful, it should still be confusing. 546 * We thus reject the case here. 547 */ 548 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) 549 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 550 551 /* 552 * Adjust the "outgoing" interface. If we're going to loop the packet 553 * back to ourselves, the ifp would be the loopback interface. 554 * However, we'd rather know the interface associated to the 555 * destination address (which should probably be one of our own 556 * addresses.) 557 */ 558 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 559 *retifp = rt->rt_ifa->ifa_ifp; 560 561 return (0); 562 } 563 564 int 565 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 566 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 567 struct rtentry **retrt, u_int rtableid) 568 { 569 570 return (selectroute(dstsock, opts, mopts, ro, retifp, retrt, 0, 571 rtableid)); 572 } 573 574 /* 575 * Default hop limit selection. The precedence is as follows: 576 * 1. Hoplimit value specified via ioctl. 577 * 2. (If the outgoing interface is detected) the current 578 * hop limit of the interface specified by router advertisement. 579 * 3. The system default hoplimit. 580 */ 581 #define in6pcb inpcb 582 #define in6p_hops inp_hops 583 int 584 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 585 { 586 if (in6p && in6p->in6p_hops >= 0) 587 return (in6p->in6p_hops); 588 else if (ifp) 589 return (ND_IFINFO(ifp)->chlim); 590 else 591 return (ip6_defhlim); 592 } 593 #undef in6pcb 594 #undef in6p_hops 595 596 /* 597 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 598 * If the address scope of is link-local, embed the interface index in the 599 * address. The routine determines our precedence 600 * between advanced API scope/interface specification and basic API 601 * specification. 602 * 603 * this function should be nuked in the future, when we get rid of 604 * embedded scopeid thing. 605 * 606 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 607 * there can be multiple interfaces that belong to a particular scope zone 608 * (in specification, we have 1:N mapping between a scope zone and interfaces). 609 * we may want to change the function to return something other than ifp. 610 */ 611 int 612 in6_embedscope(in6, sin6, in6p, ifpp) 613 struct in6_addr *in6; 614 const struct sockaddr_in6 *sin6; 615 struct inpcb *in6p; 616 #define in6p_outputopts inp_outputopts6 617 #define in6p_moptions inp_moptions6 618 struct ifnet **ifpp; 619 { 620 struct ifnet *ifp = NULL; 621 u_int32_t scopeid; 622 623 *in6 = sin6->sin6_addr; 624 scopeid = sin6->sin6_scope_id; 625 if (ifpp) 626 *ifpp = NULL; 627 628 /* 629 * don't try to read sin6->sin6_addr beyond here, since the caller may 630 * ask us to overwrite existing sockaddr_in6 631 */ 632 633 if (IN6_IS_SCOPE_EMBED(in6)) { 634 struct in6_pktinfo *pi; 635 636 /* 637 * KAME assumption: link id == interface id 638 */ 639 640 if (in6p && in6p->in6p_outputopts && 641 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 642 pi->ipi6_ifindex) { 643 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 644 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 645 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 646 in6p->in6p_moptions && 647 in6p->in6p_moptions->im6o_multicast_ifp) { 648 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 649 in6->s6_addr16[1] = htons(ifp->if_index); 650 } else if (scopeid) { 651 /* boundary check */ 652 if (scopeid < 0 || if_indexlim <= scopeid || 653 !ifindex2ifnet[scopeid]) 654 return ENXIO; /* XXX EINVAL? */ 655 ifp = ifindex2ifnet[scopeid]; 656 /*XXX assignment to 16bit from 32bit variable */ 657 in6->s6_addr16[1] = htons(scopeid & 0xffff); 658 } 659 660 if (ifpp) 661 *ifpp = ifp; 662 } 663 664 return 0; 665 } 666 #undef in6p_outputopts 667 #undef in6p_moptions 668 669 /* 670 * generate standard sockaddr_in6 from embedded form. 671 * touches sin6_addr and sin6_scope_id only. 672 * 673 * this function should be nuked in the future, when we get rid of 674 * embedded scopeid thing. 675 */ 676 int 677 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 678 struct ifnet *ifp) 679 { 680 u_int32_t scopeid; 681 682 sin6->sin6_addr = *in6; 683 684 /* 685 * don't try to read *in6 beyond here, since the caller may 686 * ask us to overwrite existing sockaddr_in6 687 */ 688 689 sin6->sin6_scope_id = 0; 690 if (IN6_IS_SCOPE_EMBED(in6)) { 691 /* 692 * KAME assumption: link id == interface id 693 */ 694 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 695 if (scopeid) { 696 /* sanity check */ 697 if (scopeid < 0 || if_indexlim <= scopeid || 698 !ifindex2ifnet[scopeid]) 699 return ENXIO; 700 if (ifp && ifp->if_index != scopeid) 701 return ENXIO; 702 sin6->sin6_addr.s6_addr16[1] = 0; 703 sin6->sin6_scope_id = scopeid; 704 } 705 } 706 707 return 0; 708 } 709 710 /* 711 * just clear the embedded scope identifer. 712 */ 713 void 714 in6_clearscope(struct in6_addr *addr) 715 { 716 if (IN6_IS_SCOPE_EMBED(addr)) 717 addr->s6_addr16[1] = 0; 718 } 719