sys/net80211/ieee80211_acl.c

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