Home | History | Annotate | Line # | Download | only in netinet6
scope6.c revision 1.6
      1 /*	$NetBSD: scope6.c,v 1.6 2007/12/11 12:30:20 lukem 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 1.6 2007/12/11 12:30:20 lukem 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()
     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 /*
    332  * generate standard sockaddr_in6 from embedded form.
    333  */
    334 int
    335 sa6_recoverscope(struct sockaddr_in6 *sin6)
    336 {
    337 	uint32_t zoneid;
    338 
    339 	if (sin6->sin6_scope_id != 0) {
    340 		log(LOG_NOTICE,
    341 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
    342 		    ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
    343 		/* XXX: proceed anyway... */
    344 	}
    345 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
    346 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
    347 		/*
    348 		 * KAME assumption: link id == interface id
    349 		 */
    350 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
    351 		if (zoneid) {
    352 			/* sanity check */
    353 			if (/* zoneid < 0 || */ if_indexlim <= zoneid)
    354 				return (ENXIO);
    355 #ifdef __FreeBSD__
    356 			if (!ifnet_byindex(zoneid))
    357 #else
    358 			if (!ifindex2ifnet[zoneid])
    359 #endif
    360 				return (ENXIO);
    361 			sin6->sin6_addr.s6_addr16[1] = 0;
    362 			sin6->sin6_scope_id = zoneid;
    363 		}
    364 	}
    365 
    366 	return 0;
    367 }
    368 
    369 int
    370 in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
    371 {
    372 	if (IN6_IS_SCOPE_EMBEDDABLE(in6))
    373 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
    374 
    375 	return 0;
    376 }
    377 
    378 /*
    379  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
    380  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
    381  * in the in6_addr structure, in6 will be modified.
    382  */
    383 int
    384 in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
    385 {
    386 	int scope;
    387 	uint32_t zoneid = 0;
    388 	const struct scope6_id *sid = SID(ifp);
    389 
    390 #ifdef DIAGNOSTIC
    391 	if (sid == NULL) { /* should not happen */
    392 		panic("in6_setscope: scope array is NULL");
    393 		/* NOTREACHED */
    394 	}
    395 #endif
    396 
    397 	/*
    398 	 * special case: the loopback address can only belong to a loopback
    399 	 * interface.
    400 	 */
    401 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
    402 		if (!(ifp->if_flags & IFF_LOOPBACK))
    403 			return (EINVAL);
    404 		else {
    405 			if (ret_id != NULL)
    406 				*ret_id = 0; /* there's no ambiguity */
    407 			return (0);
    408 		}
    409 	}
    410 
    411 	scope = in6_addrscope(in6);
    412 
    413 	if (!sid->s6id_list)
    414 		return 0;
    415 
    416 	switch (scope) {
    417 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
    418 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
    419 		break;
    420 
    421 	case IPV6_ADDR_SCOPE_LINKLOCAL:
    422 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
    423 		break;
    424 
    425 	case IPV6_ADDR_SCOPE_SITELOCAL:
    426 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
    427 		break;
    428 
    429 	case IPV6_ADDR_SCOPE_ORGLOCAL:
    430 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
    431 		break;
    432 
    433 	default:
    434 		zoneid = 0;	/* XXX: treat as global. */
    435 		break;
    436 	}
    437 
    438 	if (ret_id != NULL)
    439 		*ret_id = zoneid;
    440 
    441 	return in6_setzoneid(in6, zoneid);
    442 }
    443 
    444 /*
    445  * Just clear the embedded scope identifier.  Return 0 if the original address
    446  * is intact; return non 0 if the address is modified.
    447  */
    448 int
    449 in6_clearscope(struct in6_addr *in6)
    450 {
    451 	int modified = 0;
    452 
    453 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
    454 		if (in6->s6_addr16[1] != 0)
    455 			modified = 1;
    456 		in6->s6_addr16[1] = 0;
    457 	}
    458 
    459 	return (modified);
    460 }
    461