sys/netinet6/scope6.c

   1 /*      $NetBSD: scope6.c,v 1.7 2009/03/15 21:26:09 cegger Exp $        */
   2 /*      $KAME$  */
   3
   4 /*-
   5  * Copyright (C) 2000 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 #include <sys/cdefs.h>
  34 __KERNEL_RCSID(0, "$NetBSD: scope6.c,v 1.7 2009/03/15 21:26:09 cegger Exp $");
  35
  36 #include <sys/param.h>
  37 #include <sys/malloc.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/socket.h>
  40 #include <sys/systm.h>
  41 #include <sys/queue.h>
  42 #include <sys/syslog.h>
  43
  44 #include <net/route.h>
  45 #include <net/if.h>
  46
  47 #include <netinet/in.h>
  48
  49 #include <netinet6/in6_var.h>
  50 #include <netinet6/scope6_var.h>
  51
  52 #ifdef ENABLE_DEFAULT_SCOPE
  53 int ip6_use_defzone = 1;
  54 #else
  55 int ip6_use_defzone = 0;
  56 #endif
  57
  58 static struct scope6_id sid_default;
  59 #define SID(ifp) \
  60         (((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
  61
  62 void
  63 scope6_init(void)
  64 {
  65
  66         memset(&sid_default, 0, sizeof(sid_default));
  67 }
  68
  69 struct scope6_id *
  70 scope6_ifattach(struct ifnet *ifp)
  71 {
  72         struct scope6_id *sid;
  73
  74         sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
  75         memset(sid, 0, sizeof(*sid));
  76
  77         /*
  78          * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
  79          * Should we rather hardcode here?
  80          */
  81         sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
  82         sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
  83 #ifdef MULTI_SCOPE
  84         /* by default, we don't care about scope boundary for these scopes. */
  85         sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
  86         sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
  87 #endif
  88
  89         return sid;
  90 }
  91
  92 void
  93 scope6_ifdetach(struct scope6_id *sid)
  94 {
  95
  96         free(sid, M_IFADDR);
  97 }
  98
  99 int
 100 scope6_set(struct ifnet *ifp, const struct scope6_id *idlist)
 101 {
 102         int i;
 103         int error = 0;
 104         struct scope6_id *sid = NULL;
 105
 106         sid = SID(ifp);
 107
 108         if (!sid)       /* paranoid? */
 109                 return (EINVAL);
 110
 111         /*
 112          * XXX: We need more consistency checks of the relationship among
 113          * scopes (e.g. an organization should be larger than a site).
 114          */
 115
 116         /*
 117          * TODO(XXX): after setting, we should reflect the changes to
 118          * interface addresses, routing table entries, PCB entries...
 119          */
 120
 121         for (i = 0; i < 16; i++) {
 122                 if (idlist->s6id_list[i] &&
 123                     idlist->s6id_list[i] != sid->s6id_list[i]) {
 124                         /*
 125                          * An interface zone ID must be the corresponding
 126                          * interface index by definition.
 127                          */
 128                         if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
 129                             idlist->s6id_list[i] != ifp->if_index)
 130                                 return (EINVAL);
 131
 132                         if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
 133                             idlist->s6id_list[i] >= if_indexlim) {
 134                                 /*
 135                                  * XXX: theoretically, there should be no
 136                                  * relationship between link IDs and interface
 137                                  * IDs, but we check the consistency for
 138                                  * safety in later use.
 139                                  */
 140                                 return (EINVAL);
 141                         }
 142
 143                         /*
 144                          * XXX: we must need lots of work in this case,
 145                          * but we simply set the new value in this initial
 146                          * implementation.
 147                          */
 148                         sid->s6id_list[i] = idlist->s6id_list[i];
 149                 }
 150         }
 151
 152         return (error);
 153 }
 154
 155 int
 156 scope6_get(const struct ifnet *ifp, struct scope6_id *idlist)
 157 {
 158         /* We only need to lock the interface's afdata for SID() to work. */
 159         const struct scope6_id *sid = SID(ifp);
 160
 161         if (sid == NULL)        /* paranoid? */
 162                 return EINVAL;
 163
 164         *idlist = *sid;
 165
 166         return 0;
 167 }
 168
 169 /*
 170  * Get a scope of the address. Interface-local, link-local, site-local
 171  * or global.
 172  */
 173 int
 174 in6_addrscope(const struct in6_addr *addr)
 175 {
 176         int scope;
 177
 178         if (addr->s6_addr[0] == 0xfe) {
 179                 scope = addr->s6_addr[1] & 0xc0;
 180
 181                 switch (scope) {
 182                 case 0x80:
 183                         return IPV6_ADDR_SCOPE_LINKLOCAL;
 184                         break;
 185                 case 0xc0:
 186                         return IPV6_ADDR_SCOPE_SITELOCAL;
 187                         break;
 188                 default:
 189                         return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
 190                         break;
 191                 }
 192         }
 193
 194
 195         if (addr->s6_addr[0] == 0xff) {
 196                 scope = addr->s6_addr[1] & 0x0f;
 197
 198                 /*
 199                  * due to other scope such as reserved,
 200                  * return scope doesn't work.
 201                  */
 202                 switch (scope) {
 203                 case IPV6_ADDR_SCOPE_INTFACELOCAL:
 204                         return IPV6_ADDR_SCOPE_INTFACELOCAL;
 205                         break;
 206                 case IPV6_ADDR_SCOPE_LINKLOCAL:
 207                         return IPV6_ADDR_SCOPE_LINKLOCAL;
 208                         break;
 209                 case IPV6_ADDR_SCOPE_SITELOCAL:
 210                         return IPV6_ADDR_SCOPE_SITELOCAL;
 211                         break;
 212                 default:
 213                         return IPV6_ADDR_SCOPE_GLOBAL;
 214                         break;
 215                 }
 216         }
 217
 218         if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
 219                 if (addr->s6_addr[15] == 1) /* loopback */
 220                         return IPV6_ADDR_SCOPE_LINKLOCAL;
 221                 if (addr->s6_addr[15] == 0) {
 222                         /*
 223                          * Regard the unspecified addresses as global,
 224                          * since it has no ambiguity.
 225                          * XXX: not sure if it's correct...
 226                          */
 227                         return IPV6_ADDR_SCOPE_GLOBAL;
 228                 }
 229         }
 230
 231         return IPV6_ADDR_SCOPE_GLOBAL;
 232 }
 233
 234 /* note that ifp argument might be NULL */
 235 void
 236 scope6_setdefault(struct ifnet *ifp)
 237 {
 238
 239         /*
 240          * Currently, this function just sets the default "interfaces"
 241          * and "links" according to the given interface.
 242          * We might eventually have to separate the notion of "link" from
 243          * "interface" and provide a user interface to set the default.
 244          */
 245         if (ifp) {
 246                 sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
 247                         ifp->if_index;
 248                 sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
 249                         ifp->if_index;
 250         } else {
 251                 sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
 252                 sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
 253         }
 254 }
 255
 256 int
 257 scope6_get_default(struct scope6_id *idlist)
 258 {
 259
 260         *idlist = sid_default;
 261
 262         return (0);
 263 }
 264
 265 uint32_t
 266 scope6_addr2default(const struct in6_addr *addr)
 267 {
 268         uint32_t id;
 269
 270         /*
 271          * special case: The loopback address should be considered as
 272          * link-local, but there's no ambiguity in the syntax.
 273          */
 274         if (IN6_IS_ADDR_LOOPBACK(addr))
 275                 return (0);
 276
 277         /*
 278          * XXX: 32-bit read is atomic on all our platforms, is it OK
 279          * not to lock here?
 280          */
 281         id = sid_default.s6id_list[in6_addrscope(addr)];
 282
 283         return (id);
 284 }
 285
 286 /*
 287  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
 288  * is unspecified (=0), needs to be specified, and the default zone ID can be
 289  * used, the default value will be used.
 290  * This routine then generates the kernel-internal form: if the address scope
 291  * of is interface-local or link-local, embed the interface index in the
 292  * address.
 293  */
 294 int
 295 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
 296 {
 297         struct ifnet *ifp;
 298         uint32_t zoneid;
 299
 300         if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
 301                 zoneid = scope6_addr2default(&sin6->sin6_addr);
 302
 303         if (zoneid != 0 &&
 304             (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
 305             IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
 306                 /*
 307                  * At this moment, we only check interface-local and
 308                  * link-local scope IDs, and use interface indices as the
 309                  * zone IDs assuming a one-to-one mapping between interfaces
 310                  * and links.
 311                  */
 312                 if (if_indexlim <= zoneid)
 313                         return (ENXIO);
 314 #ifdef __FreeBSD__
 315                 ifp = ifnet_byindex(zoneid);
 316 #else
 317                 ifp = ifindex2ifnet[zoneid];
 318 #endif
 319                 if (ifp == NULL) /* XXX: this can happen for some OS */
 320                         return (ENXIO);
 321
 322                 /* XXX assignment to 16bit from 32bit variable */
 323                 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
 324
 325                 sin6->sin6_scope_id = 0;
 326         }
 327
 328         return 0;
 329 }
 330
 331 struct sockaddr *
 332 sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
 333     const struct sockaddr *src)
 334 {
 335         struct sockaddr_in6 *sin6;
 336
 337         sin6 = satosin6(sockaddr_copy(dst, socklen, src));
 338
 339         if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
 340                 return NULL;
 341
 342         return dst;
 343 }
 344
 345 /*
 346  * generate standard sockaddr_in6 from embedded form.
 347  */
 348 int
 349 sa6_recoverscope(struct sockaddr_in6 *sin6)
 350 {
 351         uint32_t zoneid;
 352
 353         if (sin6->sin6_scope_id != 0) {
 354                 log(LOG_NOTICE,
 355                     "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
 356                     ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
 357                 /* XXX: proceed anyway... */
 358         }
 359         if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
 360             IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
 361                 /*
 362                  * KAME assumption: link id == interface id
 363                  */
 364                 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
 365                 if (zoneid) {
 366                         /* sanity check */
 367                         if (/* zoneid < 0 || */ if_indexlim <= zoneid)
 368                                 return (ENXIO);
 369 #ifdef __FreeBSD__
 370                         if (!ifnet_byindex(zoneid))
 371 #else
 372                         if (!ifindex2ifnet[zoneid])
 373 #endif
 374                                 return (ENXIO);
 375                         sin6->sin6_addr.s6_addr16[1] = 0;
 376                         sin6->sin6_scope_id = zoneid;
 377                 }
 378         }
 379
 380         return 0;
 381 }
 382
 383 int
 384 in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
 385 {
 386         if (IN6_IS_SCOPE_EMBEDDABLE(in6))
 387                 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
 388
 389         return 0;
 390 }
 391
 392 /*
 393  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
 394  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
 395  * in the in6_addr structure, in6 will be modified.
 396  */
 397 int
 398 in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
 399 {
 400         int scope;
 401         uint32_t zoneid = 0;
 402         const struct scope6_id *sid = SID(ifp);
 403
 404 #ifdef DIAGNOSTIC
 405         if (sid == NULL) { /* should not happen */
 406                 panic("in6_setscope: scope array is NULL");
 407                 /* NOTREACHED */
 408         }
 409 #endif
 410
 411         /*
 412          * special case: the loopback address can only belong to a loopback
 413          * interface.
 414          */
 415         if (IN6_IS_ADDR_LOOPBACK(in6)) {
 416                 if (!(ifp->if_flags & IFF_LOOPBACK))
 417                         return (EINVAL);
 418                 else {
 419                         if (ret_id != NULL)
 420                                 *ret_id = 0; /* there's no ambiguity */
 421                         return (0);
 422                 }
 423         }
 424
 425         scope = in6_addrscope(in6);
 426
 427         if (!sid->s6id_list)
 428                 return 0;
 429
 430         switch (scope) {
 431         case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
 432                 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
 433                 break;
 434
 435         case IPV6_ADDR_SCOPE_LINKLOCAL:
 436                 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
 437                 break;
 438
 439         case IPV6_ADDR_SCOPE_SITELOCAL:
 440                 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
 441                 break;
 442
 443         case IPV6_ADDR_SCOPE_ORGLOCAL:
 444                 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
 445                 break;
 446
 447         default:
 448                 zoneid = 0;     /* XXX: treat as global. */
 449                 break;
 450         }
 451
 452         if (ret_id != NULL)
 453                 *ret_id = zoneid;
 454
 455         return in6_setzoneid(in6, zoneid);
 456 }
 457
 458 /*
 459  * Just clear the embedded scope identifier.  Return 0 if the original address
 460  * is intact; return non 0 if the address is modified.
 461  */
 462 int
 463 in6_clearscope(struct in6_addr *in6)
 464 {
 465         int modified = 0;
 466
 467         if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
 468                 if (in6->s6_addr16[1] != 0)
 469                         modified = 1;
 470                 in6->s6_addr16[1] = 0;
 471         }
 472
 473         return (modified);
 474 }