1 /*- 2 * Copyright (c) 2004-2007 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 received 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 <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/systm.h> 43 #include <sys/mbuf.h> 44 #include <sys/module.h> 45 #include <sys/queue.h> 46 47 #include <sys/socket.h> 48 49 #include <net/if.h> 50 #include <net/if_media.h> 51 #include <net/ethernet.h> 52 #include <net/route.h> 53 54 #include <net80211/ieee80211_var.h> 55 56 enum { 57 ACL_POLICY_OPEN = 0, /* open, don't check ACL's */ 58 ACL_POLICY_ALLOW = 1, /* allow traffic from MAC */ 59 ACL_POLICY_DENY = 2, /* deny traffic from MAC */ 60 }; 61 62 #define ACL_HASHSIZE 32 63 64 struct acl { 65 TAILQ_ENTRY(acl) acl_list; 66 LIST_ENTRY(acl) acl_hash; 67 uint8_t acl_macaddr[IEEE80211_ADDR_LEN]; 68 }; 69 struct aclstate { 70 acl_lock_t as_lock; 71 int as_policy; 72 int as_nacls; 73 TAILQ_HEAD(, acl) as_list; /* list of all ACL's */ 74 LIST_HEAD(, acl) as_hash[ACL_HASHSIZE]; 75 struct ieee80211com *as_ic; 76 }; 77 78 /* simple hash is enough for variation of macaddr */ 79 #define ACL_HASH(addr) \ 80 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE) 81 82 MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl"); 83 84 static int acl_free_all(struct ieee80211com *); 85 86 static int 87 acl_attach(struct ieee80211com *ic) 88 { 89 struct aclstate *as; 90 91 MALLOC(as, struct aclstate *, sizeof(struct aclstate), 92 M_80211_ACL, M_NOWAIT | M_ZERO); 93 if (as == NULL) 94 return 0; 95 ACL_LOCK_INIT(as, "acl"); 96 TAILQ_INIT(&as->as_list); 97 as->as_policy = ACL_POLICY_OPEN; 98 as->as_ic = ic; 99 ic->ic_as = as; 100 return 1; 101 } 102 103 static void 104 acl_detach(struct ieee80211com *ic) 105 { 106 struct aclstate *as = ic->ic_as; 107 108 acl_free_all(ic); 109 ic->ic_as = NULL; 110 ACL_LOCK_DESTROY(as); 111 FREE(as, M_DEVBUF); 112 } 113 114 static __inline struct acl * 115 _find_acl(struct aclstate *as, const uint8_t *macaddr) 116 { 117 struct acl *acl; 118 int hash; 119 120 hash = ACL_HASH(macaddr); 121 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 122 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr)) 123 return acl; 124 } 125 return NULL; 126 } 127 128 static void 129 _acl_free(struct aclstate *as, struct acl *acl) 130 { 131 ACL_LOCK_ASSERT(as); 132 133 TAILQ_REMOVE(&as->as_list, acl, acl_list); 134 LIST_REMOVE(acl, acl_hash); 135 FREE(acl, M_80211_ACL); 136 as->as_nacls--; 137 } 138 139 static int 140 acl_check(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN]) 141 { 142 struct aclstate *as = ic->ic_as; 143 144 switch (as->as_policy) { 145 case ACL_POLICY_OPEN: 146 return 1; 147 case ACL_POLICY_ALLOW: 148 return _find_acl(as, mac) != NULL; 149 case ACL_POLICY_DENY: 150 return _find_acl(as, mac) == NULL; 151 } 152 return 0; /* should not happen */ 153 } 154 155 static int 156 acl_add(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN]) 157 { 158 struct aclstate *as = ic->ic_as; 159 struct acl *acl, *new; 160 int hash; 161 162 MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO); 163 if (new == NULL) { 164 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 165 "ACL: add %s failed, no memory\n", ether_sprintf(mac)); 166 /* XXX statistic */ 167 return ENOMEM; 168 } 169 170 ACL_LOCK(as); 171 hash = ACL_HASH(mac); 172 LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) { 173 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) { 174 ACL_UNLOCK(as); 175 FREE(new, M_80211_ACL); 176 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 177 "ACL: add %s failed, already present\n", 178 ether_sprintf(mac)); 179 return EEXIST; 180 } 181 } 182 IEEE80211_ADDR_COPY(new->acl_macaddr, mac); 183 TAILQ_INSERT_TAIL(&as->as_list, new, acl_list); 184 LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash); 185 as->as_nacls++; 186 ACL_UNLOCK(as); 187 188 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 189 "ACL: add %s\n", ether_sprintf(mac)); 190 return 0; 191 } 192 193 static int 194 acl_remove(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN]) 195 { 196 struct aclstate *as = ic->ic_as; 197 struct acl *acl; 198 199 ACL_LOCK(as); 200 acl = _find_acl(as, mac); 201 if (acl != NULL) 202 _acl_free(as, acl); 203 ACL_UNLOCK(as); 204 205 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 206 "ACL: remove %s%s\n", ether_sprintf(mac), 207 acl == NULL ? ", not present" : ""); 208 209 return (acl == NULL ? ENOENT : 0); 210 } 211 212 static int 213 acl_free_all(struct ieee80211com *ic) 214 { 215 struct aclstate *as = ic->ic_as; 216 struct acl *acl; 217 218 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all"); 219 220 ACL_LOCK(as); 221 while ((acl = TAILQ_FIRST(&as->as_list)) != NULL) 222 _acl_free(as, acl); 223 ACL_UNLOCK(as); 224 225 return 0; 226 } 227 228 static int 229 acl_setpolicy(struct ieee80211com *ic, int policy) 230 { 231 struct aclstate *as = ic->ic_as; 232 233 IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, 234 "ACL: set policy to %u\n", policy); 235 236 switch (policy) { 237 case IEEE80211_MACCMD_POLICY_OPEN: 238 as->as_policy = ACL_POLICY_OPEN; 239 break; 240 case IEEE80211_MACCMD_POLICY_ALLOW: 241 as->as_policy = ACL_POLICY_ALLOW; 242 break; 243 case IEEE80211_MACCMD_POLICY_DENY: 244 as->as_policy = ACL_POLICY_DENY; 245 break; 246 default: 247 return EINVAL; 248 } 249 return 0; 250 } 251 252 static int 253 acl_getpolicy(struct ieee80211com *ic) 254 { 255 struct aclstate *as = ic->ic_as; 256 257 return as->as_policy; 258 } 259 260 static int 261 acl_setioctl(struct ieee80211com *ic, struct ieee80211req *ireq) 262 { 263 264 return EINVAL; 265 } 266 267 static int 268 acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq) 269 { 270 struct aclstate *as = ic->ic_as; 271 struct acl *acl; 272 struct ieee80211req_maclist *ap; 273 int error, space, i; 274 275 switch (ireq->i_val) { 276 case IEEE80211_MACCMD_POLICY: 277 ireq->i_val = as->as_policy; 278 return 0; 279 case IEEE80211_MACCMD_LIST: 280 space = as->as_nacls * IEEE80211_ADDR_LEN; 281 if (ireq->i_len == 0) { 282 ireq->i_len = space; /* return required space */ 283 return 0; /* NB: must not error */ 284 } 285 MALLOC(ap, struct ieee80211req_maclist *, space, 286 M_TEMP, M_NOWAIT); 287 if (ap == NULL) 288 return ENOMEM; 289 i = 0; 290 ACL_LOCK(as); 291 TAILQ_FOREACH(acl, &as->as_list, acl_list) { 292 IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr); 293 i++; 294 } 295 ACL_UNLOCK(as); 296 if (ireq->i_len >= space) { 297 error = copyout(ap, ireq->i_data, space); 298 ireq->i_len = space; 299 } else 300 error = copyout(ap, ireq->i_data, ireq->i_len); 301 FREE(ap, M_TEMP); 302 return error; 303 } 304 return EINVAL; 305 } 306 307 static const struct ieee80211_aclator mac = { 308 .iac_name = "mac", 309 .iac_attach = acl_attach, 310 .iac_detach = acl_detach, 311 .iac_check = acl_check, 312 .iac_add = acl_add, 313 .iac_remove = acl_remove, 314 .iac_flush = acl_free_all, 315 .iac_setpolicy = acl_setpolicy, 316 .iac_getpolicy = acl_getpolicy, 317 .iac_setioctl = acl_setioctl, 318 .iac_getioctl = acl_getioctl, 319 }; 320 321 /* 322 * Module glue. 323 */ 324 static int 325 wlan_acl_modevent(module_t mod, int type, void *unused) 326 { 327 switch (type) { 328 case MOD_LOAD: 329 if (bootverbose) 330 printf("wlan: <802.11 MAC ACL support>\n"); 331 ieee80211_aclator_register(&mac); 332 return 0; 333 case MOD_UNLOAD: 334 ieee80211_aclator_unregister(&mac); 335 return 0; 336 } 337 return EINVAL; 338 } 339 340 static moduledata_t wlan_acl_mod = { 341 "wlan_acl", 342 wlan_acl_modevent, 343 0 344 }; 345 DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 346 MODULE_VERSION(wlan_acl, 1); 347 MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1); 348