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 int as_nacls; 79 TAILQ_HEAD(, acl) as_list; /* list of all ACL's */ 80 LIST_HEAD(, acl) as_hash[ACL_HASHSIZE]; 81 struct ieee80211com *as_ic; 82 }; 83 84 /* simple hash is enough for variation of macaddr */ 85 #define ACL_HASH(addr) \ 86 (((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE) 87 88 MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl"); 89 90 static int acl_free_all(struct ieee80211com *); 91 92 static int 93 acl_attach(struct ieee80211com *ic) 94 { 95 struct aclstate *as; 96 97 MALLOC(as, struct aclstate *, sizeof(struct aclstate), 98 M_80211_ACL, M_NOWAIT | M_ZERO); 99 if (as == NULL) 100 return 0; 101 ACL_LOCK_INIT(as, "acl"); 102 TAILQ_INIT(&as->as_list); 103 as->as_policy = ACL_POLICY_OPEN; 104 as->as_ic = ic; 105 ic->ic_as = as; 106 return 1; 107 } 108 109 static void 110 acl_detach(struct ieee80211com *ic) 111 { 112 struct aclstate *as = ic->ic_as; 113 114 acl_free_all(ic); 115 ic->ic_as = NULL; 116 ACL_LOCK_DESTROY(as); 117 FREE(as, M_DEVBUF); 118 } 119 120 static __inline struct acl * 121 _find_acl(struct aclstate *as, const u_int8_t *macaddr) 122 { 123 struct acl *acl; 124 int hash; 125 126 hash = ACL_HASH(macaddr); 127 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 128 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr)) 129 return acl; 130 } 131 return NULL; 132 } 133 134 static void 135 _acl_free(struct aclstate *as, struct acl *acl) 136 { 137 ACL_LOCK_ASSERT(as); 138 139 TAILQ_REMOVE(&as->as_list, acl, acl_list); 140 LIST_REMOVE(acl, acl_hash); 141 FREE(acl, M_80211_ACL); 142 as->as_nacls--; 143 } 144 145 static int 146 acl_check(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 147 { 148 struct aclstate *as = ic->ic_as; 149 150 switch (as->as_policy) { 151 case ACL_POLICY_OPEN: 152 return 1; 153 case ACL_POLICY_ALLOW: 154 return _find_acl(as, mac) != NULL; 155 case ACL_POLICY_DENY: 156 return _find_acl(as, mac) == NULL; 157 } 158 return 0; /* should not happen */ 159 } 160 161 static int 162 acl_add(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 163 { 164 struct aclstate *as = ic->ic_as; 165 struct acl *acl, *new; 166 int hash; 167 168 MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO); 169 if (new == NULL) { 170 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 171 "ACL: add %s failed, no memory\n", ether_sprintf(mac)); 172 /* XXX statistic */ 173 return ENOMEM; 174 } 175 176 ACL_LOCK(as); 177 hash = ACL_HASH(mac); 178 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 179 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) { 180 ACL_UNLOCK(as); 181 FREE(new, M_80211_ACL); 182 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 183 "ACL: add %s failed, already present\n", 184 ether_sprintf(mac)); 185 return EEXIST; 186 } 187 } 188 IEEE80211_ADDR_COPY(new->acl_macaddr, mac); 189 TAILQ_INSERT_TAIL(&as->as_list, new, acl_list); 190 LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash); 191 as->as_nacls++; 192 ACL_UNLOCK(as); 193 194 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 195 "ACL: add %s\n", ether_sprintf(mac)); 196 return 0; 197 } 198 199 static int 200 acl_remove(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN]) 201 { 202 struct aclstate *as = ic->ic_as; 203 struct acl *acl; 204 205 ACL_LOCK(as); 206 acl = _find_acl(as, mac); 207 if (acl != NULL) 208 _acl_free(as, acl); 209 ACL_UNLOCK(as); 210 211 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 212 "ACL: remove %s%s\n", ether_sprintf(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 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all"); 225 226 ACL_LOCK(as); 227 while ((acl = TAILQ_FIRST(&as->as_list)) != NULL) 228 _acl_free(as, acl); 229 ACL_UNLOCK(as); 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 struct aclstate *as = ic->ic_as; 262 263 return as->as_policy; 264 } 265 266 static int 267 acl_setioctl(struct ieee80211com *ic, struct ieee80211req *ireq) 268 { 269 270 return EINVAL; 271 } 272 273 static int 274 acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq) 275 { 276 struct aclstate *as = ic->ic_as; 277 struct acl *acl; 278 struct ieee80211req_maclist *ap; 279 int error, space, i; 280 281 switch (ireq->i_val) { 282 case IEEE80211_MACCMD_POLICY: 283 ireq->i_val = as->as_policy; 284 return 0; 285 case IEEE80211_MACCMD_LIST: 286 space = as->as_nacls * IEEE80211_ADDR_LEN; 287 if (ireq->i_len == 0) { 288 ireq->i_len = space; /* return required space */ 289 return 0; /* NB: must not error */ 290 } 291 MALLOC(ap, struct ieee80211req_maclist *, space, 292 M_TEMP, M_NOWAIT); 293 if (ap == NULL) 294 return ENOMEM; 295 i = 0; 296 ACL_LOCK(as); 297 TAILQ_FOREACH(acl, &as->as_list, acl_list) { 298 IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr); 299 i++; 300 } 301 ACL_UNLOCK(as); 302 if (ireq->i_len >= space) { 303 error = copyout(ap, ireq->i_data, space); 304 ireq->i_len = space; 305 } else 306 error = copyout(ap, ireq->i_data, ireq->i_len); 307 FREE(ap, M_TEMP); 308 return error; 309 } 310 return EINVAL; 311 } 312 313 static const struct ieee80211_aclator mac = { 314 .iac_name = "mac", 315 .iac_attach = acl_attach, 316 .iac_detach = acl_detach, 317 .iac_check = acl_check, 318 .iac_add = acl_add, 319 .iac_remove = acl_remove, 320 .iac_flush = acl_free_all, 321 .iac_setpolicy = acl_setpolicy, 322 .iac_getpolicy = acl_getpolicy, 323 .iac_setioctl = acl_setioctl, 324 .iac_getioctl = acl_getioctl, 325 }; 326 327 /* 328 * Module glue. 329 */ 330 static int 331 wlan_acl_modevent(module_t mod, int type, void *unused) 332 { 333 switch (type) { 334 case MOD_LOAD: 335 if (bootverbose) 336 printf("wlan: <802.11 MAC ACL support>\n"); 337 ieee80211_aclator_register(&mac); 338 return 0; 339 case MOD_UNLOAD: 340 ieee80211_aclator_unregister(&mac); 341 return 0; 342 } 343 return EINVAL; 344 } 345 346 static moduledata_t wlan_acl_mod = { 347 "wlan_acl", 348 wlan_acl_modevent, 349 0 350 }; 351 DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 352 MODULE_VERSION(wlan_acl, 1); 353 MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1); 354