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 __FBSDID("$FreeBSD$"); 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 53 #include <sys/socket.h> 54 55 #include <net/if.h> 56 #include <net/if_media.h> 57 #include <net/ethernet.h> 58 #include <net/route.h> 59 60 #include <net80211/ieee80211_var.h> 61 62 enum { 63 ACL_POLICY_OPEN = 0, /* open, don't check ACL's */ 64 ACL_POLICY_ALLOW = 1, /* allow traffic from MAC */ 65 ACL_POLICY_DENY = 2, /* deny traffic from MAC */ 66 }; 67 68 #define ACL_HASHSIZE 32 69 70 struct acl { 71 TAILQ_ENTRY(acl) acl_list; 72 LIST_ENTRY(acl) acl_hash; 73 u_int8_t acl_macaddr[IEEE80211_ADDR_LEN]; 74 }; 75 struct aclstate { 76 acl_lock_t as_lock; 77 int as_policy; 78 TAILQ_HEAD(, acl) as_list; /* list of all ACL's */ 79 LIST_HEAD(, acl) as_hash[ACL_HASHSIZE]; 80 struct ieee80211com *as_ic; 81 }; 82 83 /* simple hash is enough for variation of macaddr */ 84 #define ACL_HASH(addr) \ 85 (((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE) 86 87 MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl"); 88 89 static int acl_free_all(struct ieee80211com *); 90 91 static int 92 acl_attach(struct ieee80211com *ic) 93 { 94 struct aclstate *as; 95 96 MALLOC(as, struct aclstate *, sizeof(struct aclstate), 97 M_DEVBUF, M_NOWAIT | M_ZERO); 98 if (as == NULL) 99 return 0; 100 ACL_LOCK_INIT(as, "acl"); 101 TAILQ_INIT(&as->as_list); 102 as->as_policy = ACL_POLICY_OPEN; 103 as->as_ic = ic; 104 ic->ic_as = as; 105 return 1; 106 } 107 108 static void 109 acl_detach(struct ieee80211com *ic) 110 { 111 struct aclstate *as = ic->ic_as; 112 113 acl_free_all(ic); 114 ic->ic_as = NULL; 115 ACL_LOCK_DESTROY(as); 116 FREE(as, M_DEVBUF); 117 } 118 119 static __inline struct acl * 120 _find_acl(struct aclstate *as, const u_int8_t *macaddr) 121 { 122 struct acl *acl; 123 int hash; 124 125 hash = ACL_HASH(macaddr); 126 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 127 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr)) 128 return acl; 129 } 130 return NULL; 131 } 132 133 static void 134 _acl_free(struct aclstate *as, struct acl *acl) 135 { 136 ACL_LOCK_ASSERT(as); 137 138 TAILQ_REMOVE(&as->as_list, acl, acl_list); 139 LIST_REMOVE(acl, acl_hash); 140 FREE(acl, M_80211_ACL); 141 } 142 143 static int 144 acl_check(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 145 { 146 struct aclstate *as = ic->ic_as; 147 148 switch (as->as_policy) { 149 case ACL_POLICY_OPEN: 150 return 1; 151 case ACL_POLICY_ALLOW: 152 return _find_acl(as, mac) != NULL; 153 case ACL_POLICY_DENY: 154 return _find_acl(as, mac) == NULL; 155 } 156 return 0; /* should not happen */ 157 } 158 159 static int 160 acl_add(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 161 { 162 struct aclstate *as = ic->ic_as; 163 struct acl *acl, *new; 164 int hash; 165 166 MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO); 167 if (new == NULL) { 168 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 169 "ACL: add %s failed, no memory\n", ether_sprintf(mac)); 170 /* XXX statistic */ 171 return ENOMEM; 172 } 173 174 ACL_LOCK(as); 175 hash = ACL_HASH(mac); 176 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 177 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) { 178 ACL_UNLOCK(as); 179 FREE(new, M_80211_ACL); 180 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 181 "ACL: add %s failed, already present\n", 182 ether_sprintf(mac)); 183 return EEXIST; 184 } 185 } 186 IEEE80211_ADDR_COPY(new->acl_macaddr, mac); 187 TAILQ_INSERT_TAIL(&as->as_list, new, acl_list); 188 LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash); 189 ACL_UNLOCK(as); 190 191 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 192 "ACL: add %s\n", ether_sprintf(mac)); 193 return 0; 194 } 195 196 static int 197 acl_remove(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 198 { 199 struct aclstate *as = ic->ic_as; 200 struct acl *acl; 201 202 ACL_LOCK(as); 203 acl = _find_acl(as, mac); 204 if (acl != NULL) 205 _acl_free(as, acl); 206 ACL_UNLOCK(as); 207 208 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 209 "ACL: remove %s%s\n", ether_sprintf(mac), 210 acl == NULL ? ", not present" : ""); 211 212 return (acl == NULL ? ENOENT : 0); 213 } 214 215 static int 216 acl_free_all(struct ieee80211com *ic) 217 { 218 struct aclstate *as = ic->ic_as; 219 struct acl *acl; 220 221 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all"); 222 223 ACL_LOCK(as); 224 while ((acl = TAILQ_FIRST(&as->as_list)) != NULL) 225 _acl_free(as, acl); 226 ACL_UNLOCK(as); 227 228 return 0; 229 } 230 231 static int 232 acl_setpolicy(struct ieee80211com *ic, int policy) 233 { 234 struct aclstate *as = ic->ic_as; 235 236 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 237 "ACL: set policy to %u\n", policy); 238 239 switch (policy) { 240 case IEEE80211_MACCMD_POLICY_OPEN: 241 as->as_policy = ACL_POLICY_OPEN; 242 break; 243 case IEEE80211_MACCMD_POLICY_ALLOW: 244 as->as_policy = ACL_POLICY_ALLOW; 245 break; 246 case IEEE80211_MACCMD_POLICY_DENY: 247 as->as_policy = ACL_POLICY_DENY; 248 break; 249 default: 250 return EINVAL; 251 } 252 return 0; 253 } 254 255 static int 256 acl_getpolicy(struct ieee80211com *ic) 257 { 258 struct aclstate *as = ic->ic_as; 259 260 return as->as_policy; 261 } 262 263 static const struct ieee80211_aclator mac = { 264 .iac_name = "mac", 265 .iac_attach = acl_attach, 266 .iac_detach = acl_detach, 267 .iac_check = acl_check, 268 .iac_add = acl_add, 269 .iac_remove = acl_remove, 270 .iac_flush = acl_free_all, 271 .iac_setpolicy = acl_setpolicy, 272 .iac_getpolicy = acl_getpolicy, 273 }; 274 275 /* 276 * Module glue. 277 */ 278 static int 279 wlan_acl_modevent(module_t mod, int type, void *unused) 280 { 281 switch (type) { 282 case MOD_LOAD: 283 if (bootverbose) 284 printf("wlan: <802.11 MAC ACL support>\n"); 285 ieee80211_aclator_register(&mac); 286 return 0; 287 case MOD_UNLOAD: 288 ieee80211_aclator_unregister(&mac); 289 return 0; 290 } 291 return EINVAL; 292 } 293 294 static moduledata_t wlan_acl_mod = { 295 "wlan_acl", 296 wlan_acl_modevent, 297 0 298 }; 299 DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 300 MODULE_VERSION(wlan_acl, 1); 301 MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1); 302