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ieee80211_acl.c revision 1.9.54.1
      1 /*-
      2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      3  *
      4  * Copyright (c) 2004-2008 Sam Leffler, Errno Consulting
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __FBSDID("$FreeBSD$");
     30 
     31 /*
     32  * IEEE 802.11 MAC ACL support.
     33  *
     34  * When this module is loaded the sender address of each auth mgt
     35  * frame is passed to the iac_check method and the module indicates
     36  * if the frame should be accepted or rejected.  If the policy is
     37  * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
     38  * the address.  Otherwise, the address is looked up in the database
     39  * and if found the frame is either accepted (ACL_POLICY_ALLOW)
     40  * or rejected (ACL_POLICY_DENT).
     41  */
     42 #include "opt_wlan.h"
     43 
     44 #include <sys/param.h>
     45 #include <sys/kernel.h>
     46 #include <sys/systm.h>
     47 #include <sys/malloc.h>
     48 #include <sys/mbuf.h>
     49 #include <sys/module.h>
     50 #include <sys/queue.h>
     51 
     52 #include <sys/socket.h>
     53 
     54 #include <net/if.h>
     55 #include <net/if_media.h>
     56 #include <net/ethernet.h>
     57 #include <net/route.h>
     58 
     59 #include <net80211/ieee80211_var.h>
     60 
     61 enum {
     62 	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
     63 	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
     64 	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
     65 	/*
     66 	 * NB: ACL_POLICY_RADIUS must be the same value as
     67 	 *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
     68 	 *     acl_getpolicy() works.
     69 	 */
     70 	ACL_POLICY_RADIUS	= 7,	/* defer to RADIUS ACL server */
     71 };
     72 
     73 #define	ACL_HASHSIZE	32
     74 
     75 struct acl {
     76 	TAILQ_ENTRY(acl)	acl_list;
     77 	LIST_ENTRY(acl)		acl_hash;
     78 	uint8_t			acl_macaddr[IEEE80211_ADDR_LEN];
     79 };
     80 struct aclstate {
     81 	acl_lock_t		as_lock;
     82 	int			as_policy;
     83 	uint32_t		as_nacls;
     84 	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
     85 	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
     86 	struct ieee80211vap	*as_vap;
     87 };
     88 
     89 /* simple hash is enough for variation of macaddr */
     90 #define	ACL_HASH(addr)	\
     91 	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
     92 
     93 static MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
     94 
     95 static	int acl_free_all(struct ieee80211vap *);
     96 
     97 /* number of references from net80211 layer */
     98 static	int nrefs = 0;
     99 
    100 static int
    101 acl_attach(struct ieee80211vap *vap)
    102 {
    103 	struct aclstate *as;
    104 
    105 	as = (struct aclstate *) IEEE80211_MALLOC(sizeof(struct aclstate),
    106 		M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
    107 	if (as == NULL)
    108 		return 0;
    109 	ACL_LOCK_INIT(as, "acl");
    110 	TAILQ_INIT(&as->as_list);
    111 	as->as_policy = ACL_POLICY_OPEN;
    112 	as->as_vap = vap;
    113 	vap->iv_as = as;
    114 	nrefs++;			/* NB: we assume caller locking */
    115 	return 1;
    116 }
    117 
    118 static void
    119 acl_detach(struct ieee80211vap *vap)
    120 {
    121 	struct aclstate *as = vap->iv_as;
    122 
    123 	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
    124 	nrefs--;			/* NB: we assume caller locking */
    125 
    126 	acl_free_all(vap);
    127 	vap->iv_as = NULL;
    128 	ACL_LOCK_DESTROY(as);
    129 	IEEE80211_FREE(as, M_80211_ACL);
    130 }
    131 
    132 static __inline struct acl *
    133 _find_acl(struct aclstate *as, const uint8_t *macaddr)
    134 {
    135 	struct acl *acl;
    136 	int hash;
    137 
    138 	hash = ACL_HASH(macaddr);
    139 	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
    140 		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
    141 			return acl;
    142 	}
    143 	return NULL;
    144 }
    145 
    146 static void
    147 _acl_free(struct aclstate *as, struct acl *acl)
    148 {
    149 	ACL_LOCK_ASSERT(as);
    150 
    151 	TAILQ_REMOVE(&as->as_list, acl, acl_list);
    152 	LIST_REMOVE(acl, acl_hash);
    153 	IEEE80211_FREE(acl, M_80211_ACL);
    154 	as->as_nacls--;
    155 }
    156 
    157 static int
    158 acl_check(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
    159 {
    160 	struct aclstate *as = vap->iv_as;
    161 
    162 	switch (as->as_policy) {
    163 	case ACL_POLICY_OPEN:
    164 	case ACL_POLICY_RADIUS:
    165 		return 1;
    166 	case ACL_POLICY_ALLOW:
    167 		return _find_acl(as, wh->i_addr2) != NULL;
    168 	case ACL_POLICY_DENY:
    169 		return _find_acl(as, wh->i_addr2) == NULL;
    170 	}
    171 	return 0;		/* should not happen */
    172 }
    173 
    174 static int
    175 acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
    176 {
    177 	struct aclstate *as = vap->iv_as;
    178 	struct acl *acl, *new;
    179 	int hash;
    180 
    181 	new = (struct acl *) IEEE80211_MALLOC(sizeof(struct acl),
    182 	    M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
    183 	if (new == NULL) {
    184 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
    185 			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
    186 		/* XXX statistic */
    187 		return ENOMEM;
    188 	}
    189 
    190 	ACL_LOCK(as);
    191 	hash = ACL_HASH(mac);
    192 	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
    193 		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
    194 			ACL_UNLOCK(as);
    195 			IEEE80211_FREE(new, M_80211_ACL);
    196 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
    197 				"ACL: add %s failed, already present\n",
    198 				ether_sprintf(mac));
    199 			return EEXIST;
    200 		}
    201 	}
    202 	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
    203 	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
    204 	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
    205 	as->as_nacls++;
    206 	ACL_UNLOCK(as);
    207 
    208 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
    209 		"ACL: add %s\n", ether_sprintf(mac));
    210 	return 0;
    211 }
    212 
    213 static int
    214 acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
    215 {
    216 	struct aclstate *as = vap->iv_as;
    217 	struct acl *acl;
    218 
    219 	ACL_LOCK(as);
    220 	acl = _find_acl(as, mac);
    221 	if (acl != NULL)
    222 		_acl_free(as, acl);
    223 	ACL_UNLOCK(as);
    224 
    225 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
    226 		"ACL: remove %s%s\n", ether_sprintf(mac),
    227 		acl == NULL ? ", not present" : "");
    228 
    229 	return (acl == NULL ? ENOENT : 0);
    230 }
    231 
    232 static int
    233 acl_free_all(struct ieee80211vap *vap)
    234 {
    235 	struct aclstate *as = vap->iv_as;
    236 	struct acl *acl;
    237 
    238 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
    239 
    240 	ACL_LOCK(as);
    241 	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
    242 		_acl_free(as, acl);
    243 	ACL_UNLOCK(as);
    244 
    245 	return 0;
    246 }
    247 
    248 static int
    249 acl_setpolicy(struct ieee80211vap *vap, int policy)
    250 {
    251 	struct aclstate *as = vap->iv_as;
    252 
    253 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
    254 		"ACL: set policy to %u\n", policy);
    255 
    256 	switch (policy) {
    257 	case IEEE80211_MACCMD_POLICY_OPEN:
    258 		as->as_policy = ACL_POLICY_OPEN;
    259 		break;
    260 	case IEEE80211_MACCMD_POLICY_ALLOW:
    261 		as->as_policy = ACL_POLICY_ALLOW;
    262 		break;
    263 	case IEEE80211_MACCMD_POLICY_DENY:
    264 		as->as_policy = ACL_POLICY_DENY;
    265 		break;
    266 	case IEEE80211_MACCMD_POLICY_RADIUS:
    267 		as->as_policy = ACL_POLICY_RADIUS;
    268 		break;
    269 	default:
    270 		return EINVAL;
    271 	}
    272 	return 0;
    273 }
    274 
    275 static int
    276 acl_getpolicy(struct ieee80211vap *vap)
    277 {
    278 	struct aclstate *as = vap->iv_as;
    279 
    280 	return as->as_policy;
    281 }
    282 
    283 static int
    284 acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
    285 {
    286 
    287 	return EINVAL;
    288 }
    289 
    290 static int
    291 acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
    292 {
    293 	struct aclstate *as = vap->iv_as;
    294 	struct acl *acl;
    295 	struct ieee80211req_maclist *ap;
    296 	int error;
    297 	uint32_t i, space;
    298 
    299 	switch (ireq->i_val) {
    300 	case IEEE80211_MACCMD_POLICY:
    301 		ireq->i_val = as->as_policy;
    302 		return 0;
    303 	case IEEE80211_MACCMD_LIST:
    304 		space = as->as_nacls * IEEE80211_ADDR_LEN;
    305 		if (ireq->i_len == 0) {
    306 			ireq->i_len = space;	/* return required space */
    307 			return 0;		/* NB: must not error */
    308 		}
    309 		ap = (struct ieee80211req_maclist *) IEEE80211_MALLOC(space,
    310 		    M_TEMP, IEEE80211_M_NOWAIT);
    311 		if (ap == NULL)
    312 			return ENOMEM;
    313 		i = 0;
    314 		ACL_LOCK(as);
    315 		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
    316 			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
    317 			i++;
    318 		}
    319 		ACL_UNLOCK(as);
    320 		if (ireq->i_len >= space) {
    321 			error = copyout(ap, ireq->i_data, space);
    322 			ireq->i_len = space;
    323 		} else
    324 			error = copyout(ap, ireq->i_data, ireq->i_len);
    325 		IEEE80211_FREE(ap, M_TEMP);
    326 		return error;
    327 	}
    328 	return EINVAL;
    329 }
    330 
    331 static const struct ieee80211_aclator mac = {
    332 	.iac_name	= "mac",
    333 	.iac_attach	= acl_attach,
    334 	.iac_detach	= acl_detach,
    335 	.iac_check	= acl_check,
    336 	.iac_add	= acl_add,
    337 	.iac_remove	= acl_remove,
    338 	.iac_flush	= acl_free_all,
    339 	.iac_setpolicy	= acl_setpolicy,
    340 	.iac_getpolicy	= acl_getpolicy,
    341 	.iac_setioctl	= acl_setioctl,
    342 	.iac_getioctl	= acl_getioctl,
    343 };
    344 IEEE80211_ACL_MODULE(wlan_acl, mac, 1);
    345