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 software may be distributed under the terms of the BSD license. 8 * See README for more details. 9 */ 10 11 #include "utils/includes.h" 12 13 #include "utils/common.h" 14 #include "utils/eloop.h" 15 #include "common/ieee802_11_defs.h" 16 #include "common/ieee802_11_common.h" 17 #include "drivers/driver.h" 18 #include "hostapd.h" 19 #include "ap_config.h" 20 #include "ieee802_11.h" 21 #include "sta_info.h" 22 #include "beacon.h" 23 #include "ap_list.h" 24 25 26 /* AP list is a double linked list with head->prev pointing to the end of the 27 * list and tail->next = NULL. Entries are moved to the head of the list 28 * whenever a beacon has been received from the AP in question. The tail entry 29 * in this link will thus be the least recently used entry. */ 30 31 32 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap) 33 { 34 int i; 35 36 if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G || 37 iface->conf->channel != ap->channel) 38 return 0; 39 40 if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT)) 41 return 1; 42 43 for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) { 44 int rate = (ap->supported_rates[i] & 0x7f) * 5; 45 if (rate == 60 || rate == 90 || rate > 110) 46 return 0; 47 } 48 49 return 1; 50 } 51 52 53 static struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap) 54 { 55 struct ap_info *s; 56 57 s = iface->ap_hash[STA_HASH(ap)]; 58 while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0) 59 s = s->hnext; 60 return s; 61 } 62 63 64 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap) 65 { 66 if (iface->ap_list) { 67 ap->prev = iface->ap_list->prev; 68 iface->ap_list->prev = ap; 69 } else 70 ap->prev = ap; 71 ap->next = iface->ap_list; 72 iface->ap_list = ap; 73 } 74 75 76 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap) 77 { 78 if (iface->ap_list == ap) 79 iface->ap_list = ap->next; 80 else 81 ap->prev->next = ap->next; 82 83 if (ap->next) 84 ap->next->prev = ap->prev; 85 else if (iface->ap_list) 86 iface->ap_list->prev = ap->prev; 87 } 88 89 90 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap) 91 { 92 ap->hnext = iface->ap_hash[STA_HASH(ap->addr)]; 93 iface->ap_hash[STA_HASH(ap->addr)] = ap; 94 } 95 96 97 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap) 98 { 99 struct ap_info *s; 100 101 s = iface->ap_hash[STA_HASH(ap->addr)]; 102 if (s == NULL) return; 103 if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) { 104 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext; 105 return; 106 } 107 108 while (s->hnext != NULL && 109 os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0) 110 s = s->hnext; 111 if (s->hnext != NULL) 112 s->hnext = s->hnext->hnext; 113 else 114 printf("AP: could not remove AP " MACSTR " from hash table\n", 115 MAC2STR(ap->addr)); 116 } 117 118 119 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap) 120 { 121 ap_ap_hash_del(iface, ap); 122 ap_ap_list_del(iface, ap); 123 124 iface->num_ap--; 125 os_free(ap); 126 } 127 128 129 static void hostapd_free_aps(struct hostapd_iface *iface) 130 { 131 struct ap_info *ap, *prev; 132 133 ap = iface->ap_list; 134 135 while (ap) { 136 prev = ap; 137 ap = ap->next; 138 ap_free_ap(iface, prev); 139 } 140 141 iface->ap_list = NULL; 142 } 143 144 145 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr) 146 { 147 struct ap_info *ap; 148 149 ap = os_zalloc(sizeof(struct ap_info)); 150 if (ap == NULL) 151 return NULL; 152 153 /* initialize AP info data */ 154 os_memcpy(ap->addr, addr, ETH_ALEN); 155 ap_ap_list_add(iface, ap); 156 iface->num_ap++; 157 ap_ap_hash_add(iface, ap); 158 159 if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) { 160 wpa_printf(MSG_DEBUG, "Removing the least recently used AP " 161 MACSTR " from AP table", MAC2STR(ap->prev->addr)); 162 ap_free_ap(iface, ap->prev); 163 } 164 165 return ap; 166 } 167 168 169 void ap_list_process_beacon(struct hostapd_iface *iface, 170 const struct ieee80211_mgmt *mgmt, 171 struct ieee802_11_elems *elems, 172 struct hostapd_frame_info *fi) 173 { 174 struct ap_info *ap; 175 struct os_time now; 176 int new_ap = 0; 177 int set_beacon = 0; 178 179 if (iface->conf->ap_table_max_size < 1) 180 return; 181 182 ap = ap_get_ap(iface, mgmt->bssid); 183 if (!ap) { 184 ap = ap_ap_add(iface, mgmt->bssid); 185 if (!ap) { 186 printf("Failed to allocate AP information entry\n"); 187 return; 188 } 189 new_ap = 1; 190 } 191 192 merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX, 193 elems->supp_rates, elems->supp_rates_len, 194 elems->ext_supp_rates, elems->ext_supp_rates_len); 195 196 if (elems->erp_info && elems->erp_info_len == 1) 197 ap->erp = elems->erp_info[0]; 198 else 199 ap->erp = -1; 200 201 if (elems->ds_params && elems->ds_params_len == 1) 202 ap->channel = elems->ds_params[0]; 203 else if (elems->ht_operation && elems->ht_operation_len >= 1) 204 ap->channel = elems->ht_operation[0]; 205 else if (fi) 206 ap->channel = fi->channel; 207 208 if (elems->ht_capabilities) 209 ap->ht_support = 1; 210 else 211 ap->ht_support = 0; 212 213 os_get_time(&now); 214 ap->last_beacon = now.sec; 215 216 if (!new_ap && ap != iface->ap_list) { 217 /* move AP entry into the beginning of the list so that the 218 * oldest entry is always in the end of the list */ 219 ap_ap_list_del(iface, ap); 220 ap_ap_list_add(iface, ap); 221 } 222 223 if (!iface->olbc && 224 ap_list_beacon_olbc(iface, ap)) { 225 iface->olbc = 1; 226 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR 227 " (channel %d) - enable protection", 228 MAC2STR(ap->addr), ap->channel); 229 set_beacon++; 230 } 231 232 #ifdef CONFIG_IEEE80211N 233 if (!iface->olbc_ht && !ap->ht_support && 234 (ap->channel == 0 || 235 ap->channel == iface->conf->channel || 236 ap->channel == iface->conf->channel + 237 iface->conf->secondary_channel * 4)) { 238 iface->olbc_ht = 1; 239 hostapd_ht_operation_update(iface); 240 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR 241 " (channel %d) - enable protection", 242 MAC2STR(ap->addr), ap->channel); 243 set_beacon++; 244 } 245 #endif /* CONFIG_IEEE80211N */ 246 247 if (set_beacon) 248 ieee802_11_update_beacons(iface); 249 } 250 251 252 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx) 253 { 254 struct hostapd_iface *iface = eloop_ctx; 255 struct os_time now; 256 struct ap_info *ap; 257 int set_beacon = 0; 258 259 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL); 260 261 if (!iface->ap_list) 262 return; 263 264 os_get_time(&now); 265 266 while (iface->ap_list) { 267 ap = iface->ap_list->prev; 268 if (ap->last_beacon + iface->conf->ap_table_expiration_time >= 269 now.sec) 270 break; 271 272 ap_free_ap(iface, ap); 273 } 274 275 if (iface->olbc || iface->olbc_ht) { 276 int olbc = 0; 277 int olbc_ht = 0; 278 279 ap = iface->ap_list; 280 while (ap && (olbc == 0 || olbc_ht == 0)) { 281 if (ap_list_beacon_olbc(iface, ap)) 282 olbc = 1; 283 if (!ap->ht_support) 284 olbc_ht = 1; 285 ap = ap->next; 286 } 287 if (!olbc && iface->olbc) { 288 wpa_printf(MSG_DEBUG, "OLBC not detected anymore"); 289 iface->olbc = 0; 290 set_beacon++; 291 } 292 #ifdef CONFIG_IEEE80211N 293 if (!olbc_ht && iface->olbc_ht) { 294 wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore"); 295 iface->olbc_ht = 0; 296 hostapd_ht_operation_update(iface); 297 set_beacon++; 298 } 299 #endif /* CONFIG_IEEE80211N */ 300 } 301 302 if (set_beacon) 303 ieee802_11_update_beacons(iface); 304 } 305 306 307 int ap_list_init(struct hostapd_iface *iface) 308 { 309 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL); 310 return 0; 311 } 312 313 314 void ap_list_deinit(struct hostapd_iface *iface) 315 { 316 eloop_cancel_timeout(ap_list_timer, iface, NULL); 317 hostapd_free_aps(iface); 318 } 319
