sys/netproto/802_11/wlan_acl/ieee80211_acl.c

   1 /*
   2  * Copyright (c) 2004-2005 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  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * Alternatively, this software may be distributed under the terms of the
  17  * GNU General Public License ("GPL") version 2 as published by the Free
  18  * Software Foundation.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/sys/net80211/ieee80211_acl.c,v 1.3.2.1 2005/09/03 22:40:02 sam Exp $
  32  * $DragonFly: src/sys/netproto/802_11/wlan_acl/ieee80211_acl.c,v 1.3 2006/12/22 23:57:53 swildner Exp $
  33  */
  34
  35 /*
  36  * IEEE 802.11 MAC ACL support.
  37  *
  38  * When this module is loaded the sender address of each received
  39  * frame is passed to the iac_check method and the module indicates
  40  * if the frame should be accepted or rejected.  If the policy is
  41  * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
  42  * the address.  Otherwise, the address is looked up in the database
  43  * and if found the frame is either accepted (ACL_POLICY_ALLOW)
  44  * or rejected (ACL_POLICY_DENT).
  45  */
  46 #include <sys/param.h>
  47 #include <sys/kernel.h>
  48 #include <sys/systm.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/module.h>
  51 #include <sys/queue.h>
  52 #include <sys/serialize.h>
  53
  54 #include <sys/socket.h>
  55
  56 #include <net/if.h>
  57 #include <net/if_arp.h>
  58 #include <net/if_media.h>
  59 #include <net/ethernet.h>
  60 #include <net/route.h>
  61
  62 #include <netproto/802_11/ieee80211_var.h>
  63
  64 enum {
  65         ACL_POLICY_OPEN         = 0,    /* open, don't check ACL's */
  66         ACL_POLICY_ALLOW        = 1,    /* allow traffic from MAC */
  67         ACL_POLICY_DENY         = 2,    /* deny traffic from MAC */
  68 };
  69
  70 #define ACL_HASHSIZE    32
  71
  72 struct acl {
  73         TAILQ_ENTRY(acl)        acl_list;
  74         LIST_ENTRY(acl)         acl_hash;
  75         uint8_t                 acl_macaddr[IEEE80211_ADDR_LEN];
  76 };
  77 struct aclstate {
  78 #if 0
  79         acl_lock_t              as_lock;
  80 #endif
  81         int                     as_policy;
  82         int                     as_nacls;
  83         TAILQ_HEAD(, acl)       as_list;        /* list of all ACL's */
  84         LIST_HEAD(, acl)        as_hash[ACL_HASHSIZE];
  85         struct ieee80211com     *as_ic;
  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 MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
  93
  94 static  int acl_free_all(struct ieee80211com *);
  95
  96 static int
  97 acl_attach(struct ieee80211com *ic)
  98 {
  99         struct aclstate *as;
 100
 101         as = kmalloc(sizeof(struct aclstate), M_80211_ACL, M_NOWAIT | M_ZERO);
 102         if (as == NULL)
 103                 return 0;
 104         TAILQ_INIT(&as->as_list);
 105         as->as_policy = ACL_POLICY_OPEN;
 106         as->as_ic = ic;
 107         ic->ic_as = as;
 108         return 1;
 109 }
 110
 111 static void
 112 acl_detach(struct ieee80211com *ic)
 113 {
 114         struct aclstate *as = ic->ic_as;
 115
 116         acl_free_all(ic);
 117         ic->ic_as = NULL;
 118         kfree(as, M_DEVBUF);
 119 }
 120
 121 static __inline struct acl *
 122 _find_acl(struct aclstate *as, const uint8_t *macaddr)
 123 {
 124         struct acl *acl;
 125         int hash;
 126
 127         hash = ACL_HASH(macaddr);
 128         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 129                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
 130                         return acl;
 131         }
 132         return NULL;
 133 }
 134
 135 static void
 136 _acl_free(struct aclstate *as, struct acl *acl)
 137 {
 138         ASSERT_SERIALIZED(as->as_ic->ic_ifp->if_serializer);
 139
 140         TAILQ_REMOVE(&as->as_list, acl, acl_list);
 141         LIST_REMOVE(acl, acl_hash);
 142         kfree(acl, M_80211_ACL);
 143         as->as_nacls--;
 144 }
 145
 146 static int
 147 acl_check(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
 148 {
 149         struct aclstate *as = ic->ic_as;
 150
 151         switch (as->as_policy) {
 152         case ACL_POLICY_OPEN:
 153                 return 1;
 154         case ACL_POLICY_ALLOW:
 155                 return _find_acl(as, mac) != NULL;
 156         case ACL_POLICY_DENY:
 157                 return _find_acl(as, mac) == NULL;
 158         }
 159         return 0;               /* should not happen */
 160 }
 161
 162 static int
 163 acl_add(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
 164 {
 165         struct aclstate *as = ic->ic_as;
 166         struct acl *acl, *new;
 167         int hash;
 168
 169         ASSERT_SERIALIZED(ic->ic_ifp->if_serializer);
 170
 171         new = kmalloc(sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
 172         if (new == NULL) {
 173                 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 174                         "ACL: add %6D failed, no memory\n", mac, ":");
 175                 /* XXX statistic */
 176                 return ENOMEM;
 177         }
 178
 179         hash = ACL_HASH(mac);
 180         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 181                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
 182                         FREE(new, M_80211_ACL);
 183                         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 184                                 "ACL: add %6D failed, already present\n",
 185                                 mac, ":");
 186                         return EEXIST;
 187                 }
 188         }
 189         IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
 190         TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
 191         LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
 192         as->as_nacls++;
 193
 194         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 195                 "ACL: add %6D\n", mac, ":");
 196         return 0;
 197 }
 198
 199 static int
 200 acl_remove(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
 201 {
 202         struct aclstate *as = ic->ic_as;
 203         struct acl *acl;
 204
 205         ASSERT_SERIALIZED(ic->ic_ifp->if_serializer);
 206
 207         acl = _find_acl(as, mac);
 208         if (acl != NULL)
 209                 _acl_free(as, acl);
 210
 211         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 212                 "ACL: remove %6D%s\n", mac, ":",
 213                 acl == NULL ? ", not present" : "");
 214
 215         return (acl == NULL ? ENOENT : 0);
 216 }
 217
 218 static int
 219 acl_free_all(struct ieee80211com *ic)
 220 {
 221         struct aclstate *as = ic->ic_as;
 222         struct acl *acl;
 223
 224         ASSERT_SERIALIZED(ic->ic_ifp->if_serializer);
 225
 226         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
 227
 228         while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
 229                 _acl_free(as, acl);
 230
 231         return 0;
 232 }
 233
 234 static int
 235 acl_setpolicy(struct ieee80211com *ic, int policy)
 236 {
 237         struct aclstate *as = ic->ic_as;
 238
 239         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 240                 "ACL: set policy to %u\n", policy);
 241
 242         switch (policy) {
 243         case IEEE80211_MACCMD_POLICY_OPEN:
 244                 as->as_policy = ACL_POLICY_OPEN;
 245                 break;
 246         case IEEE80211_MACCMD_POLICY_ALLOW:
 247                 as->as_policy = ACL_POLICY_ALLOW;
 248                 break;
 249         case IEEE80211_MACCMD_POLICY_DENY:
 250                 as->as_policy = ACL_POLICY_DENY;
 251                 break;
 252         default:
 253                 return EINVAL;
 254         }
 255         return 0;
 256 }
 257
 258 static int
 259 acl_getpolicy(struct ieee80211com *ic)
 260 {
 261         return ((struct aclstate *)(ic->ic_as))->as_policy;
 262 }
 263
 264 static int
 265 acl_setioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
 266 {
 267         return EINVAL;
 268 }
 269
 270 static int
 271 acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
 272 {
 273         struct aclstate *as = ic->ic_as;
 274         struct acl *acl;
 275         struct ieee80211req_maclist *ap;
 276         int error, space, i;
 277
 278         ASSERT_SERIALIZED(ic->ic_ifp->if_serializer);
 279
 280         switch (ireq->i_val) {
 281         case IEEE80211_MACCMD_POLICY:
 282                 ireq->i_val = as->as_policy;
 283                 return 0;
 284         case IEEE80211_MACCMD_LIST:
 285                 space = as->as_nacls * IEEE80211_ADDR_LEN;
 286                 if (ireq->i_len == 0) {
 287                         ireq->i_len = space;    /* return required space */
 288                         return 0;               /* NB: must not error */
 289                 }
 290                 ap = kmalloc(space, M_TEMP, M_NOWAIT);
 291                 if (ap == NULL)
 292                         return ENOMEM;
 293                 i = 0;
 294                 TAILQ_FOREACH(acl, &as->as_list, acl_list) {
 295                         IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
 296                         i++;
 297                 }
 298                 if (ireq->i_len >= space) {
 299                         error = copyout(ap, ireq->i_data, space);
 300                         ireq->i_len = space;
 301                 } else
 302                         error = copyout(ap, ireq->i_data, ireq->i_len);
 303                 kfree(ap, M_TEMP);
 304                 return error;
 305         }
 306         return EINVAL;
 307 }
 308
 309 static const struct ieee80211_aclator mac = {
 310         .iac_name       = "mac",
 311         .iac_attach     = acl_attach,
 312         .iac_detach     = acl_detach,
 313         .iac_check      = acl_check,
 314         .iac_add        = acl_add,
 315         .iac_remove     = acl_remove,
 316         .iac_flush      = acl_free_all,
 317         .iac_setpolicy  = acl_setpolicy,
 318         .iac_getpolicy  = acl_getpolicy,
 319         .iac_setioctl   = acl_setioctl,
 320         .iac_getioctl   = acl_getioctl,
 321 };
 322
 323 /*
 324  * Module glue.
 325  */
 326 static int
 327 wlan_acl_modevent(module_t mod, int type, void *unused)
 328 {
 329         switch (type) {
 330         case MOD_LOAD:
 331                 if (bootverbose)
 332                         kprintf("wlan: <802.11 MAC ACL support>\n");
 333                 ieee80211_aclator_register(&mac);
 334                 return 0;
 335         case MOD_UNLOAD:
 336                 ieee80211_aclator_unregister(&mac);
 337                 return 0;
 338         }
 339         return EINVAL;
 340 }
 341
 342 static moduledata_t wlan_acl_mod = {
 343         "wlan_acl",
 344         wlan_acl_modevent,
 345         0
 346 };
 347 DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
 348 MODULE_VERSION(wlan_acl, 1);
 349 MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1);