sys/netproto/802_11/wlan_acl/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_var.h>
  54 #include <net/if_media.h>
  55 #include <net/ethernet.h>
  56 #include <net/route.h>
  57
  58 #include <netproto/802_11/ieee80211_var.h>
  59
  60 enum {
  61         ACL_POLICY_OPEN         = 0,    /* open, don't check ACL's */
  62         ACL_POLICY_ALLOW        = 1,    /* allow traffic from MAC */
  63         ACL_POLICY_DENY         = 2,    /* deny traffic from MAC */
  64         /*
  65          * NB: ACL_POLICY_RADIUS must be the same value as
  66          *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
  67          *     acl_getpolicy() works.
  68          */
  69         ACL_POLICY_RADIUS       = 7,    /* defer to RADIUS ACL server */
  70 };
  71
  72 #define ACL_HASHSIZE    32
  73
  74 struct acl {
  75         TAILQ_ENTRY(acl)        acl_list;
  76         LIST_ENTRY(acl)         acl_hash;
  77         uint8_t                 acl_macaddr[IEEE80211_ADDR_LEN];
  78 };
  79 struct aclstate {
  80         acl_lock_t              as_lock;
  81         int                     as_policy;
  82         uint32_t                as_nacls;
  83         TAILQ_HEAD(, acl)       as_list;        /* list of all ACL's */
  84         LIST_HEAD(, acl)        as_hash[ACL_HASHSIZE];
  85         struct ieee80211vap     *as_vap;
  86 };
  87
  88 /* simple hash is enough for variation of macaddr */
  89 #define ACL_HASH(addr)  \
  90         (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
  91
  92 static MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
  93
  94 static  int acl_free_all(struct ieee80211vap *);
  95
  96 /* number of references from net80211 layer */
  97 static  int nrefs = 0;
  98
  99 static int
 100 acl_attach(struct ieee80211vap *vap)
 101 {
 102         struct aclstate *as;
 103
 104 #if defined(__DragonFly__)
 105         as = (struct aclstate *) kmalloc(sizeof(struct aclstate),
 106                 M_80211_ACL, M_INTWAIT | M_ZERO);
 107 #else
 108         as = (struct aclstate *) IEEE80211_MALLOC(sizeof(struct aclstate),
 109                 M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
 110 #endif
 111         if (as == NULL)
 112                 return 0;
 113         ACL_LOCK_INIT(as, "acl");
 114         TAILQ_INIT(&as->as_list);
 115         as->as_policy = ACL_POLICY_OPEN;
 116         as->as_vap = vap;
 117         vap->iv_as = as;
 118         nrefs++;                        /* NB: we assume caller locking */
 119         return 1;
 120 }
 121
 122 static void
 123 acl_detach(struct ieee80211vap *vap)
 124 {
 125         struct aclstate *as = vap->iv_as;
 126
 127         KASSERT(nrefs > 0, ("imbalanced attach/detach"));
 128         nrefs--;                        /* NB: we assume caller locking */
 129
 130         acl_free_all(vap);
 131         vap->iv_as = NULL;
 132         ACL_LOCK_DESTROY(as);
 133         IEEE80211_FREE(as, M_80211_ACL);
 134 }
 135
 136 static __inline struct acl *
 137 _find_acl(struct aclstate *as, const uint8_t *macaddr)
 138 {
 139         struct acl *acl;
 140         int hash;
 141
 142         hash = ACL_HASH(macaddr);
 143         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 144                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
 145                         return acl;
 146         }
 147         return NULL;
 148 }
 149
 150 static void
 151 _acl_free(struct aclstate *as, struct acl *acl)
 152 {
 153         ACL_LOCK_ASSERT(as);
 154
 155         TAILQ_REMOVE(&as->as_list, acl, acl_list);
 156         LIST_REMOVE(acl, acl_hash);
 157         IEEE80211_FREE(acl, M_80211_ACL);
 158         as->as_nacls--;
 159 }
 160
 161 static int
 162 acl_check(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
 163 {
 164         struct aclstate *as = vap->iv_as;
 165
 166         switch (as->as_policy) {
 167         case ACL_POLICY_OPEN:
 168         case ACL_POLICY_RADIUS:
 169                 return 1;
 170         case ACL_POLICY_ALLOW:
 171                 return _find_acl(as, wh->i_addr2) != NULL;
 172         case ACL_POLICY_DENY:
 173                 return _find_acl(as, wh->i_addr2) == NULL;
 174         }
 175         return 0;               /* should not happen */
 176 }
 177
 178 static int
 179 acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
 180 {
 181         struct aclstate *as = vap->iv_as;
 182         struct acl *acl, *new;
 183         int hash;
 184
 185 #if defined(__DragonFly__)
 186         new = (struct acl *) kmalloc(sizeof(struct acl),
 187                 M_80211_ACL, M_INTWAIT | M_ZERO);
 188 #else
 189         new = (struct acl *) IEEE80211_MALLOC(sizeof(struct acl),
 190                 M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
 191 #endif
 192         if (new == NULL) {
 193                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 194                         "ACL: add %s failed, no memory\n", ether_sprintf(mac));
 195                 /* XXX statistic */
 196                 return ENOMEM;
 197         }
 198
 199         ACL_LOCK(as);
 200         hash = ACL_HASH(mac);
 201         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 202                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
 203                         ACL_UNLOCK(as);
 204                         IEEE80211_FREE(new, M_80211_ACL);
 205                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 206                                 "ACL: add %s failed, already present\n",
 207                                 ether_sprintf(mac));
 208                         return EEXIST;
 209                 }
 210         }
 211         IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
 212         TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
 213         LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
 214         as->as_nacls++;
 215         ACL_UNLOCK(as);
 216
 217         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 218                 "ACL: add %s\n", ether_sprintf(mac));
 219         return 0;
 220 }
 221
 222 static int
 223 acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
 224 {
 225         struct aclstate *as = vap->iv_as;
 226         struct acl *acl;
 227
 228         ACL_LOCK(as);
 229         acl = _find_acl(as, mac);
 230         if (acl != NULL)
 231                 _acl_free(as, acl);
 232         ACL_UNLOCK(as);
 233
 234         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 235                 "ACL: remove %s%s\n", ether_sprintf(mac),
 236                 acl == NULL ? ", not present" : "");
 237
 238         return (acl == NULL ? ENOENT : 0);
 239 }
 240
 241 static int
 242 acl_free_all(struct ieee80211vap *vap)
 243 {
 244         struct aclstate *as = vap->iv_as;
 245         struct acl *acl;
 246
 247         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
 248
 249         ACL_LOCK(as);
 250         while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
 251                 _acl_free(as, acl);
 252         ACL_UNLOCK(as);
 253
 254         return 0;
 255 }
 256
 257 static int
 258 acl_setpolicy(struct ieee80211vap *vap, int policy)
 259 {
 260         struct aclstate *as = vap->iv_as;
 261
 262         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 263                 "ACL: set policy to %u\n", policy);
 264
 265         switch (policy) {
 266         case IEEE80211_MACCMD_POLICY_OPEN:
 267                 as->as_policy = ACL_POLICY_OPEN;
 268                 break;
 269         case IEEE80211_MACCMD_POLICY_ALLOW:
 270                 as->as_policy = ACL_POLICY_ALLOW;
 271                 break;
 272         case IEEE80211_MACCMD_POLICY_DENY:
 273                 as->as_policy = ACL_POLICY_DENY;
 274                 break;
 275         case IEEE80211_MACCMD_POLICY_RADIUS:
 276                 as->as_policy = ACL_POLICY_RADIUS;
 277                 break;
 278         default:
 279                 return EINVAL;
 280         }
 281         return 0;
 282 }
 283
 284 static int
 285 acl_getpolicy(struct ieee80211vap *vap)
 286 {
 287         struct aclstate *as = vap->iv_as;
 288
 289         return as->as_policy;
 290 }
 291
 292 static int
 293 acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
 294 {
 295
 296         return EINVAL;
 297 }
 298
 299 static int
 300 acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
 301 {
 302         struct aclstate *as = vap->iv_as;
 303         struct acl *acl;
 304         struct ieee80211req_maclist *ap;
 305         int error;
 306         uint32_t i, space;
 307
 308         switch (ireq->i_val) {
 309         case IEEE80211_MACCMD_POLICY:
 310                 ireq->i_val = as->as_policy;
 311                 return 0;
 312         case IEEE80211_MACCMD_LIST:
 313                 space = as->as_nacls * IEEE80211_ADDR_LEN;
 314                 if (ireq->i_len == 0) {
 315                         ireq->i_len = space;    /* return required space */
 316                         return 0;               /* NB: must not error */
 317                 }
 318 #if defined(__DragonFly__)
 319                 ap = (struct ieee80211req_maclist *) kmalloc(space,
 320                     M_TEMP, M_INTWAIT);
 321 #else
 322                 ap = (struct ieee80211req_maclist *) IEEE80211_MALLOC(space,
 323                     M_TEMP, IEEE80211_M_NOWAIT);
 324 #endif
 325                 if (ap == NULL)
 326                         return ENOMEM;
 327                 i = 0;
 328                 ACL_LOCK(as);
 329                 TAILQ_FOREACH(acl, &as->as_list, acl_list) {
 330                         IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
 331                         i++;
 332                 }
 333                 ACL_UNLOCK(as);
 334                 if (ireq->i_len >= space) {
 335                         error = copyout(ap, ireq->i_data, space);
 336                         ireq->i_len = space;
 337                 } else
 338                         error = copyout(ap, ireq->i_data, ireq->i_len);
 339                 IEEE80211_FREE(ap, M_TEMP);
 340                 return error;
 341         }
 342         return EINVAL;
 343 }
 344
 345 static const struct ieee80211_aclator mac = {
 346         .iac_name       = "mac",
 347         .iac_attach     = acl_attach,
 348         .iac_detach     = acl_detach,
 349         .iac_check      = acl_check,
 350         .iac_add        = acl_add,
 351         .iac_remove     = acl_remove,
 352         .iac_flush      = acl_free_all,
 353         .iac_setpolicy  = acl_setpolicy,
 354         .iac_getpolicy  = acl_getpolicy,
 355         .iac_setioctl   = acl_setioctl,
 356         .iac_getioctl   = acl_getioctl,
 357 };
 358 IEEE80211_ACL_MODULE(wlan_acl, mac, 1);