1 /* 2 * hostapd / AP table 3 * Copyright (c) 2002-2009, Jouni Malinen <j (at) w1.fi> 4 * Copyright (c) 2003-2004, Instant802 Networks, Inc. 5 * Copyright (c) 2006, Devicescape Software, Inc. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * Alternatively, this software may be distributed under the terms of BSD 12 * license. 13 * 14 * See README and COPYING for more details. 15 */ 16 17 #include "utils/includes.h" 18 19 #include "utils/common.h" 20 #include "utils/eloop.h" 21 #include "common/ieee802_11_defs.h" 22 #include "common/ieee802_11_common.h" 23 #include "drivers/driver.h" 24 #include "hostapd.h" 25 #include "ap_config.h" 26 #include "ieee802_11.h" 27 #include "sta_info.h" 28 #include "beacon.h" 29 #include "ap_list.h" 30 31 32 /* AP list is a double linked list with head->prev pointing to the end of the 33 * list and tail->next = NULL. Entries are moved to the head of the list 34 * whenever a beacon has been received from the AP in question. The tail entry 35 * in this link will thus be the least recently used entry. */ 36 37 38 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap) 39 { 40 int i; 41 42 if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G || 43 iface->conf->channel != ap->channel) 44 return 0; 45 46 if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT)) 47 return 1; 48 49 for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) { 50 int rate = (ap->supported_rates[i] & 0x7f) * 5; 51 if (rate == 60 || rate == 90 || rate > 110) 52 return 0; 53 } 54 55 return 1; 56 } 57 58 59 struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap) 60 { 61 struct ap_info *s; 62 63 s = iface->ap_hash[STA_HASH(ap)]; 64 while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0) 65 s = s->hnext; 66 return s; 67 } 68 69 70 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap) 71 { 72 if (iface->ap_list) { 73 ap->prev = iface->ap_list->prev; 74 iface->ap_list->prev = ap; 75 } else 76 ap->prev = ap; 77 ap->next = iface->ap_list; 78 iface->ap_list = ap; 79 } 80 81 82 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap) 83 { 84 if (iface->ap_list == ap) 85 iface->ap_list = ap->next; 86 else 87 ap->prev->next = ap->next; 88 89 if (ap->next) 90 ap->next->prev = ap->prev; 91 else if (iface->ap_list) 92 iface->ap_list->prev = ap->prev; 93 } 94 95 96 static void ap_ap_iter_list_add(struct hostapd_iface *iface, 97 struct ap_info *ap) 98 { 99 if (iface->ap_iter_list) { 100 ap->iter_prev = iface->ap_iter_list->iter_prev; 101 iface->ap_iter_list->iter_prev = ap; 102 } else 103 ap->iter_prev = ap; 104 ap->iter_next = iface->ap_iter_list; 105 iface->ap_iter_list = ap; 106 } 107 108 109 static void ap_ap_iter_list_del(struct hostapd_iface *iface, 110 struct ap_info *ap) 111 { 112 if (iface->ap_iter_list == ap) 113 iface->ap_iter_list = ap->iter_next; 114 else 115 ap->iter_prev->iter_next = ap->iter_next; 116 117 if (ap->iter_next) 118 ap->iter_next->iter_prev = ap->iter_prev; 119 else if (iface->ap_iter_list) 120 iface->ap_iter_list->iter_prev = ap->iter_prev; 121 } 122 123 124 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap) 125 { 126 ap->hnext = iface->ap_hash[STA_HASH(ap->addr)]; 127 iface->ap_hash[STA_HASH(ap->addr)] = ap; 128 } 129 130 131 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap) 132 { 133 struct ap_info *s; 134 135 s = iface->ap_hash[STA_HASH(ap->addr)]; 136 if (s == NULL) return; 137 if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) { 138 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext; 139 return; 140 } 141 142 while (s->hnext != NULL && 143 os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0) 144 s = s->hnext; 145 if (s->hnext != NULL) 146 s->hnext = s->hnext->hnext; 147 else 148 printf("AP: could not remove AP " MACSTR " from hash table\n", 149 MAC2STR(ap->addr)); 150 } 151 152 153 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap) 154 { 155 ap_ap_hash_del(iface, ap); 156 ap_ap_list_del(iface, ap); 157 ap_ap_iter_list_del(iface, ap); 158 159 iface->num_ap--; 160 os_free(ap); 161 } 162 163 164 static void hostapd_free_aps(struct hostapd_iface *iface) 165 { 166 struct ap_info *ap, *prev; 167 168 ap = iface->ap_list; 169 170 while (ap) { 171 prev = ap; 172 ap = ap->next; 173 ap_free_ap(iface, prev); 174 } 175 176 iface->ap_list = NULL; 177 } 178 179 180 int ap_ap_for_each(struct hostapd_iface *iface, 181 int (*func)(struct ap_info *s, void *data), void *data) 182 { 183 struct ap_info *s; 184 int ret = 0; 185 186 s = iface->ap_list; 187 188 while (s) { 189 ret = func(s, data); 190 if (ret) 191 break; 192 s = s->next; 193 } 194 195 return ret; 196 } 197 198 199 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr) 200 { 201 struct ap_info *ap; 202 203 ap = os_zalloc(sizeof(struct ap_info)); 204 if (ap == NULL) 205 return NULL; 206 207 /* initialize AP info data */ 208 os_memcpy(ap->addr, addr, ETH_ALEN); 209 ap_ap_list_add(iface, ap); 210 iface->num_ap++; 211 ap_ap_hash_add(iface, ap); 212 ap_ap_iter_list_add(iface, ap); 213 214 if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) { 215 wpa_printf(MSG_DEBUG, "Removing the least recently used AP " 216 MACSTR " from AP table", MAC2STR(ap->prev->addr)); 217 ap_free_ap(iface, ap->prev); 218 } 219 220 return ap; 221 } 222 223 224 void ap_list_process_beacon(struct hostapd_iface *iface, 225 const struct ieee80211_mgmt *mgmt, 226 struct ieee802_11_elems *elems, 227 struct hostapd_frame_info *fi) 228 { 229 struct ap_info *ap; 230 struct os_time now; 231 int new_ap = 0; 232 size_t len; 233 int set_beacon = 0; 234 235 if (iface->conf->ap_table_max_size < 1) 236 return; 237 238 ap = ap_get_ap(iface, mgmt->bssid); 239 if (!ap) { 240 ap = ap_ap_add(iface, mgmt->bssid); 241 if (!ap) { 242 printf("Failed to allocate AP information entry\n"); 243 return; 244 } 245 new_ap = 1; 246 } 247 248 ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int); 249 ap->capability = le_to_host16(mgmt->u.beacon.capab_info); 250 251 if (elems->ssid) { 252 len = elems->ssid_len; 253 if (len >= sizeof(ap->ssid)) 254 len = sizeof(ap->ssid) - 1; 255 os_memcpy(ap->ssid, elems->ssid, len); 256 ap->ssid[len] = '\0'; 257 ap->ssid_len = len; 258 } 259 260 os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX); 261 len = 0; 262 if (elems->supp_rates) { 263 len = elems->supp_rates_len; 264 if (len > WLAN_SUPP_RATES_MAX) 265 len = WLAN_SUPP_RATES_MAX; 266 os_memcpy(ap->supported_rates, elems->supp_rates, len); 267 } 268 if (elems->ext_supp_rates) { 269 int len2; 270 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX) 271 len2 = WLAN_SUPP_RATES_MAX - len; 272 else 273 len2 = elems->ext_supp_rates_len; 274 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates, 275 len2); 276 } 277 278 ap->wpa = elems->wpa_ie != NULL; 279 280 if (elems->erp_info && elems->erp_info_len == 1) 281 ap->erp = elems->erp_info[0]; 282 else 283 ap->erp = -1; 284 285 if (elems->ds_params && elems->ds_params_len == 1) 286 ap->channel = elems->ds_params[0]; 287 else if (fi) 288 ap->channel = fi->channel; 289 290 if (elems->ht_capabilities) 291 ap->ht_support = 1; 292 else 293 ap->ht_support = 0; 294 295 ap->num_beacons++; 296 os_get_time(&now); 297 ap->last_beacon = now.sec; 298 if (fi) { 299 ap->ssi_signal = fi->ssi_signal; 300 ap->datarate = fi->datarate; 301 } 302 303 if (!new_ap && ap != iface->ap_list) { 304 /* move AP entry into the beginning of the list so that the 305 * oldest entry is always in the end of the list */ 306 ap_ap_list_del(iface, ap); 307 ap_ap_list_add(iface, ap); 308 } 309 310 if (!iface->olbc && 311 ap_list_beacon_olbc(iface, ap)) { 312 iface->olbc = 1; 313 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable " 314 "protection", MAC2STR(ap->addr)); 315 set_beacon++; 316 } 317 318 #ifdef CONFIG_IEEE80211N 319 if (!iface->olbc_ht && !ap->ht_support) { 320 iface->olbc_ht = 1; 321 hostapd_ht_operation_update(iface); 322 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR 323 " - enable protection", MAC2STR(ap->addr)); 324 set_beacon++; 325 } 326 #endif /* CONFIG_IEEE80211N */ 327 328 if (set_beacon) 329 ieee802_11_set_beacons(iface); 330 } 331 332 333 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx) 334 { 335 struct hostapd_iface *iface = eloop_ctx; 336 struct os_time now; 337 struct ap_info *ap; 338 int set_beacon = 0; 339 340 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL); 341 342 if (!iface->ap_list) 343 return; 344 345 os_get_time(&now); 346 347 while (iface->ap_list) { 348 ap = iface->ap_list->prev; 349 if (ap->last_beacon + iface->conf->ap_table_expiration_time >= 350 now.sec) 351 break; 352 353 ap_free_ap(iface, ap); 354 } 355 356 if (iface->olbc || iface->olbc_ht) { 357 int olbc = 0; 358 int olbc_ht = 0; 359 360 ap = iface->ap_list; 361 while (ap && (olbc == 0 || olbc_ht == 0)) { 362 if (ap_list_beacon_olbc(iface, ap)) 363 olbc = 1; 364 if (!ap->ht_support) 365 olbc_ht = 1; 366 ap = ap->next; 367 } 368 if (!olbc && iface->olbc) { 369 wpa_printf(MSG_DEBUG, "OLBC not detected anymore"); 370 iface->olbc = 0; 371 set_beacon++; 372 } 373 #ifdef CONFIG_IEEE80211N 374 if (!olbc_ht && iface->olbc_ht) { 375 wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore"); 376 iface->olbc_ht = 0; 377 hostapd_ht_operation_update(iface); 378 set_beacon++; 379 } 380 #endif /* CONFIG_IEEE80211N */ 381 } 382 383 if (set_beacon) 384 ieee802_11_set_beacons(iface); 385 } 386 387 388 int ap_list_init(struct hostapd_iface *iface) 389 { 390 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL); 391 return 0; 392 } 393 394 395 void ap_list_deinit(struct hostapd_iface *iface) 396 { 397 eloop_cancel_timeout(ap_list_timer, iface, NULL); 398 hostapd_free_aps(iface); 399 } 400
