1 /* 2 * hostapd / AP table 3 * Copyright (c) 2002-2009, Jouni Malinen <j@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 "hostapd.h" 18 #include "ap_config.h" 19 #include "ieee802_11.h" 20 #include "sta_info.h" 21 #include "beacon.h" 22 #include "ap_list.h" 23 24 25 /* AP list is a double linked list with head->prev pointing to the end of the 26 * list and tail->next = NULL. Entries are moved to the head of the list 27 * whenever a beacon has been received from the AP in question. The tail entry 28 * in this link will thus be the least recently used entry. */ 29 30 31 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap) 32 { 33 int i; 34 35 if (iface->current_mode == NULL || 36 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 wpa_printf(MSG_INFO, "AP: could not remove AP " MACSTR 115 " from hash table", 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 int new_ap = 0; 176 int set_beacon = 0; 177 178 if (iface->conf->ap_table_max_size < 1) 179 return; 180 181 ap = ap_get_ap(iface, mgmt->bssid); 182 if (!ap) { 183 ap = ap_ap_add(iface, mgmt->bssid); 184 if (!ap) { 185 wpa_printf(MSG_INFO, 186 "Failed to allocate AP information entry"); 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) 197 ap->erp = elems->erp_info[0]; 198 else 199 ap->erp = -1; 200 201 if (elems->ds_params) 202 ap->channel = elems->ds_params[0]; 203 else if (elems->ht_operation) 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_reltime(&ap->last_beacon); 214 215 if (!new_ap && ap != iface->ap_list) { 216 /* move AP entry into the beginning of the list so that the 217 * oldest entry is always in the end of the list */ 218 ap_ap_list_del(iface, ap); 219 ap_ap_list_add(iface, ap); 220 } 221 222 if (!iface->olbc && 223 ap_list_beacon_olbc(iface, ap)) { 224 iface->olbc = 1; 225 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR 226 " (channel %d) - enable protection", 227 MAC2STR(ap->addr), ap->channel); 228 set_beacon++; 229 } 230 231 if (!iface->olbc_ht && !ap->ht_support && 232 (ap->channel == 0 || 233 ap->channel == iface->conf->channel || 234 ap->channel == iface->conf->channel + 235 iface->conf->secondary_channel * 4)) { 236 iface->olbc_ht = 1; 237 hostapd_ht_operation_update(iface); 238 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR 239 " (channel %d) - enable protection", 240 MAC2STR(ap->addr), ap->channel); 241 set_beacon++; 242 } 243 244 if (set_beacon) 245 ieee802_11_update_beacons(iface); 246 } 247 248 249 void ap_list_timer(struct hostapd_iface *iface) 250 { 251 struct os_reltime now; 252 struct ap_info *ap; 253 int set_beacon = 0; 254 255 if (!iface->ap_list) 256 return; 257 258 os_get_reltime(&now); 259 260 while (iface->ap_list) { 261 ap = iface->ap_list->prev; 262 if (!os_reltime_expired(&now, &ap->last_beacon, 263 iface->conf->ap_table_expiration_time)) 264 break; 265 266 ap_free_ap(iface, ap); 267 } 268 269 if (iface->olbc || iface->olbc_ht) { 270 int olbc = 0; 271 int olbc_ht = 0; 272 273 ap = iface->ap_list; 274 while (ap && (olbc == 0 || olbc_ht == 0)) { 275 if (ap_list_beacon_olbc(iface, ap)) 276 olbc = 1; 277 if (!ap->ht_support) 278 olbc_ht = 1; 279 ap = ap->next; 280 } 281 if (!olbc && iface->olbc) { 282 wpa_printf(MSG_DEBUG, "OLBC not detected anymore"); 283 iface->olbc = 0; 284 set_beacon++; 285 } 286 if (!olbc_ht && iface->olbc_ht) { 287 wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore"); 288 iface->olbc_ht = 0; 289 hostapd_ht_operation_update(iface); 290 set_beacon++; 291 } 292 } 293 294 if (set_beacon) 295 ieee802_11_update_beacons(iface); 296 } 297 298 299 int ap_list_init(struct hostapd_iface *iface) 300 { 301 return 0; 302 } 303 304 305 void ap_list_deinit(struct hostapd_iface *iface) 306 { 307 hostapd_free_aps(iface); 308 } 309