sys/net80211/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
  32 #include <sys/cdefs.h>
  33 #ifdef __FreeBSD__
  34 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_acl.c,v 1.4 2005/08/13 17:31:48 sam Exp $");
  35 #endif
  36 #ifdef __NetBSD__
  37 __KERNEL_RCSID(0, "$NetBSD: ieee80211_acl.c,v 1.7 2006/11/16 01:33:40 christos Exp $");
  38 #endif
  39
  40 /*
  41  * IEEE 802.11 MAC ACL support.
  42  *
  43  * When this module is loaded the sender address of each received
  44  * frame is passed to the iac_check method and the module indicates
  45  * if the frame should be accepted or rejected.  If the policy is
  46  * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
  47  * the address.  Otherwise, the address is looked up in the database
  48  * and if found the frame is either accepted (ACL_POLICY_ALLOW)
  49  * or rejected (ACL_POLICY_DENT).
  50  */
  51 #include <sys/param.h>
  52 #include <sys/kernel.h>
  53 #include <sys/systm.h>
  54 #include <sys/mbuf.h>
  55 #include <sys/queue.h>
  56
  57 #include <sys/socket.h>
  58
  59 #include <net/if.h>
  60 #include <net/if_media.h>
  61 #include <net/if_ether.h>
  62 #include <net/route.h>
  63
  64 #include <net80211/ieee80211_var.h>
  65
  66 enum {
  67         ACL_POLICY_OPEN         = 0,    /* open, don't check ACL's */
  68         ACL_POLICY_ALLOW        = 1,    /* allow traffic from MAC */
  69         ACL_POLICY_DENY         = 2,    /* deny traffic from MAC */
  70 };
  71
  72 #define ACL_HASHSIZE    32
  73
  74 struct acl {
  75         TAILQ_ENTRY(acl)        acl_list;
  76         LIST_ENTRY(acl)         acl_hash;
  77         u_int8_t                acl_macaddr[IEEE80211_ADDR_LEN];
  78 };
  79 struct aclstate {
  80         acl_lock_t              as_lock;
  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 u_int8_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 = malloc(sizeof(struct aclstate),
 102                 M_80211_ACL, M_NOWAIT | M_ZERO);
 103         if (as == NULL)
 104                 return 0;
 105         ACL_LOCK_INIT(as, "acl");
 106         TAILQ_INIT(&as->as_list);
 107         as->as_policy = ACL_POLICY_OPEN;
 108         as->as_ic = ic;
 109         ic->ic_as = as;
 110         return 1;
 111 }
 112
 113 static void
 114 acl_detach(struct ieee80211com *ic)
 115 {
 116         struct aclstate *as = ic->ic_as;
 117
 118         acl_free_all(ic);
 119         ic->ic_as = NULL;
 120         ACL_LOCK_DESTROY(as);
 121         free(as, M_DEVBUF);
 122 }
 123
 124 static __inline struct acl *
 125 _find_acl(struct aclstate *as, const u_int8_t *macaddr)
 126 {
 127         struct acl *acl;
 128         int hash;
 129
 130         hash = ACL_HASH(macaddr);
 131         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 132                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
 133                         return acl;
 134         }
 135         return NULL;
 136 }
 137
 138 static void
 139 _acl_free(struct aclstate *as, struct acl *acl)
 140 {
 141         ACL_LOCK_ASSERT(as);
 142
 143         TAILQ_REMOVE(&as->as_list, acl, acl_list);
 144         LIST_REMOVE(acl, acl_hash);
 145         free(acl, M_80211_ACL);
 146         as->as_nacls--;
 147 }
 148
 149 static int
 150 acl_check(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
 151 {
 152         struct aclstate *as = ic->ic_as;
 153
 154         switch (as->as_policy) {
 155         case ACL_POLICY_OPEN:
 156                 return 1;
 157         case ACL_POLICY_ALLOW:
 158                 return _find_acl(as, mac) != NULL;
 159         case ACL_POLICY_DENY:
 160                 return _find_acl(as, mac) == NULL;
 161         }
 162         return 0;               /* should not happen */
 163 }
 164
 165 static int
 166 acl_add(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
 167 {
 168         struct aclstate *as = ic->ic_as;
 169         struct acl *acl, *new;
 170         int hash;
 171
 172         new = malloc(sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
 173         if (new == NULL) {
 174                 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 175                         "ACL: add %s failed, no memory\n", ether_sprintf(mac));
 176                 /* XXX statistic */
 177                 return ENOMEM;
 178         }
 179
 180         ACL_LOCK(as);
 181         hash = ACL_HASH(mac);
 182         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 183                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
 184                         ACL_UNLOCK(as);
 185                         free(new, M_80211_ACL);
 186                         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 187                                 "ACL: add %s failed, already present\n",
 188                                 ether_sprintf(mac));
 189                         return EEXIST;
 190                 }
 191         }
 192         IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
 193         TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
 194         LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
 195         as->as_nacls++;
 196         ACL_UNLOCK(as);
 197
 198         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 199                 "ACL: add %s\n", ether_sprintf(mac));
 200         return 0;
 201 }
 202
 203 static int
 204 acl_remove(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
 205 {
 206         struct aclstate *as = ic->ic_as;
 207         struct acl *acl;
 208
 209         ACL_LOCK(as);
 210         acl = _find_acl(as, mac);
 211         if (acl != NULL)
 212                 _acl_free(as, acl);
 213         ACL_UNLOCK(as);
 214
 215         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 216                 "ACL: remove %s%s\n", ether_sprintf(mac),
 217                 acl == NULL ? ", not present" : "");
 218
 219         return (acl == NULL ? ENOENT : 0);
 220 }
 221
 222 static int
 223 acl_free_all(struct ieee80211com *ic)
 224 {
 225         struct aclstate *as = ic->ic_as;
 226         struct acl *acl;
 227
 228         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
 229
 230         ACL_LOCK(as);
 231         while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
 232                 _acl_free(as, acl);
 233         ACL_UNLOCK(as);
 234
 235         return 0;
 236 }
 237
 238 static int
 239 acl_setpolicy(struct ieee80211com *ic, int policy)
 240 {
 241         struct aclstate *as = ic->ic_as;
 242
 243         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
 244                 "ACL: set policy to %u\n", policy);
 245
 246         switch (policy) {
 247         case IEEE80211_MACCMD_POLICY_OPEN:
 248                 as->as_policy = ACL_POLICY_OPEN;
 249                 break;
 250         case IEEE80211_MACCMD_POLICY_ALLOW:
 251                 as->as_policy = ACL_POLICY_ALLOW;
 252                 break;
 253         case IEEE80211_MACCMD_POLICY_DENY:
 254                 as->as_policy = ACL_POLICY_DENY;
 255                 break;
 256         default:
 257                 return EINVAL;
 258         }
 259         return 0;
 260 }
 261
 262 static int
 263 acl_getpolicy(struct ieee80211com *ic)
 264 {
 265         struct aclstate *as = ic->ic_as;
 266
 267         return as->as_policy;
 268 }
 269
 270 static int
 271 acl_setioctl(struct ieee80211com *ic,
 272     struct ieee80211req *ireq)
 273 {
 274
 275         return EINVAL;
 276 }
 277
 278 static int
 279 acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
 280 {
 281         struct aclstate *as = ic->ic_as;
 282         struct acl *acl;
 283         struct ieee80211req_maclist *ap;
 284         int error, space, i;
 285
 286         switch (ireq->i_val) {
 287         case IEEE80211_MACCMD_POLICY:
 288                 ireq->i_val = as->as_policy;
 289                 return 0;
 290         case IEEE80211_MACCMD_LIST:
 291                 space = as->as_nacls * IEEE80211_ADDR_LEN;
 292                 if (ireq->i_len == 0) {
 293                         ireq->i_len = space;    /* return required space */
 294                         return 0;               /* NB: must not error */
 295                 }
 296                 ap = malloc(space, M_TEMP, M_NOWAIT);
 297                 if (ap == NULL)
 298                         return ENOMEM;
 299                 i = 0;
 300                 ACL_LOCK(as);
 301                 TAILQ_FOREACH(acl, &as->as_list, acl_list) {
 302                         IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
 303                         i++;
 304                 }
 305                 ACL_UNLOCK(as);
 306                 if (ireq->i_len >= space) {
 307                         error = copyout(ap, ireq->i_data, space);
 308                         ireq->i_len = space;
 309                 } else
 310                         error = copyout(ap, ireq->i_data, ireq->i_len);
 311                 free(ap, M_TEMP);
 312                 return error;
 313         }
 314         return EINVAL;
 315 }
 316
 317 static const struct ieee80211_aclator mac = {
 318         .iac_name       = "mac",
 319         .iac_attach     = acl_attach,
 320         .iac_detach     = acl_detach,
 321         .iac_check      = acl_check,
 322         .iac_add        = acl_add,
 323         .iac_remove     = acl_remove,
 324         .iac_flush      = acl_free_all,
 325         .iac_setpolicy  = acl_setpolicy,
 326         .iac_getpolicy  = acl_getpolicy,
 327         .iac_setioctl   = acl_setioctl,
 328         .iac_getioctl   = acl_getioctl,
 329 };