contrib/wpa/src/ap/ap_list.c

   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 "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 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_iter_list_add(struct hostapd_iface *iface,
  91                                 struct ap_info *ap)
  92 {
  93         if (iface->ap_iter_list) {
  94                 ap->iter_prev = iface->ap_iter_list->iter_prev;
  95                 iface->ap_iter_list->iter_prev = ap;
  96         } else
  97                 ap->iter_prev = ap;
  98         ap->iter_next = iface->ap_iter_list;
  99         iface->ap_iter_list = ap;
 100 }
 101
 102
 103 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 104                                 struct ap_info *ap)
 105 {
 106         if (iface->ap_iter_list == ap)
 107                 iface->ap_iter_list = ap->iter_next;
 108         else
 109                 ap->iter_prev->iter_next = ap->iter_next;
 110
 111         if (ap->iter_next)
 112                 ap->iter_next->iter_prev = ap->iter_prev;
 113         else if (iface->ap_iter_list)
 114                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 115 }
 116
 117
 118 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 119 {
 120         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 121         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 122 }
 123
 124
 125 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 126 {
 127         struct ap_info *s;
 128
 129         s = iface->ap_hash[STA_HASH(ap->addr)];
 130         if (s == NULL) return;
 131         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 132                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 133                 return;
 134         }
 135
 136         while (s->hnext != NULL &&
 137                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 138                 s = s->hnext;
 139         if (s->hnext != NULL)
 140                 s->hnext = s->hnext->hnext;
 141         else
 142                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 143                        MAC2STR(ap->addr));
 144 }
 145
 146
 147 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 148 {
 149         ap_ap_hash_del(iface, ap);
 150         ap_ap_list_del(iface, ap);
 151         ap_ap_iter_list_del(iface, ap);
 152
 153         iface->num_ap--;
 154         os_free(ap);
 155 }
 156
 157
 158 static void hostapd_free_aps(struct hostapd_iface *iface)
 159 {
 160         struct ap_info *ap, *prev;
 161
 162         ap = iface->ap_list;
 163
 164         while (ap) {
 165                 prev = ap;
 166                 ap = ap->next;
 167                 ap_free_ap(iface, prev);
 168         }
 169
 170         iface->ap_list = NULL;
 171 }
 172
 173
 174 int ap_ap_for_each(struct hostapd_iface *iface,
 175                    int (*func)(struct ap_info *s, void *data), void *data)
 176 {
 177         struct ap_info *s;
 178         int ret = 0;
 179
 180         s = iface->ap_list;
 181
 182         while (s) {
 183                 ret = func(s, data);
 184                 if (ret)
 185                         break;
 186                 s = s->next;
 187         }
 188
 189         return ret;
 190 }
 191
 192
 193 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
 194 {
 195         struct ap_info *ap;
 196
 197         ap = os_zalloc(sizeof(struct ap_info));
 198         if (ap == NULL)
 199                 return NULL;
 200
 201         /* initialize AP info data */
 202         os_memcpy(ap->addr, addr, ETH_ALEN);
 203         ap_ap_list_add(iface, ap);
 204         iface->num_ap++;
 205         ap_ap_hash_add(iface, ap);
 206         ap_ap_iter_list_add(iface, ap);
 207
 208         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 209                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 210                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 211                 ap_free_ap(iface, ap->prev);
 212         }
 213
 214         return ap;
 215 }
 216
 217
 218 void ap_list_process_beacon(struct hostapd_iface *iface,
 219                             const struct ieee80211_mgmt *mgmt,
 220                             struct ieee802_11_elems *elems,
 221                             struct hostapd_frame_info *fi)
 222 {
 223         struct ap_info *ap;
 224         struct os_time now;
 225         int new_ap = 0;
 226         size_t len;
 227         int set_beacon = 0;
 228
 229         if (iface->conf->ap_table_max_size < 1)
 230                 return;
 231
 232         ap = ap_get_ap(iface, mgmt->bssid);
 233         if (!ap) {
 234                 ap = ap_ap_add(iface, mgmt->bssid);
 235                 if (!ap) {
 236                         printf("Failed to allocate AP information entry\n");
 237                         return;
 238                 }
 239                 new_ap = 1;
 240         }
 241
 242         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 243         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 244
 245         if (elems->ssid) {
 246                 len = elems->ssid_len;
 247                 if (len >= sizeof(ap->ssid))
 248                         len = sizeof(ap->ssid) - 1;
 249                 os_memcpy(ap->ssid, elems->ssid, len);
 250                 ap->ssid[len] = '\0';
 251                 ap->ssid_len = len;
 252         }
 253
 254         merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
 255                           elems->supp_rates, elems->supp_rates_len,
 256                           elems->ext_supp_rates, elems->ext_supp_rates_len);
 257
 258         ap->wpa = elems->wpa_ie != NULL;
 259
 260         if (elems->erp_info && elems->erp_info_len == 1)
 261                 ap->erp = elems->erp_info[0];
 262         else
 263                 ap->erp = -1;
 264
 265         if (elems->ds_params && elems->ds_params_len == 1)
 266                 ap->channel = elems->ds_params[0];
 267         else if (fi)
 268                 ap->channel = fi->channel;
 269
 270         if (elems->ht_capabilities)
 271                 ap->ht_support = 1;
 272         else
 273                 ap->ht_support = 0;
 274
 275         ap->num_beacons++;
 276         os_get_time(&now);
 277         ap->last_beacon = now.sec;
 278         if (fi)
 279                 ap->datarate = fi->datarate;
 280
 281         if (!new_ap && ap != iface->ap_list) {
 282                 /* move AP entry into the beginning of the list so that the
 283                  * oldest entry is always in the end of the list */
 284                 ap_ap_list_del(iface, ap);
 285                 ap_ap_list_add(iface, ap);
 286         }
 287
 288         if (!iface->olbc &&
 289             ap_list_beacon_olbc(iface, ap)) {
 290                 iface->olbc = 1;
 291                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 292                            "protection", MAC2STR(ap->addr));
 293                 set_beacon++;
 294         }
 295
 296 #ifdef CONFIG_IEEE80211N
 297         if (!iface->olbc_ht && !ap->ht_support) {
 298                 iface->olbc_ht = 1;
 299                 hostapd_ht_operation_update(iface);
 300                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 301                            " - enable protection", MAC2STR(ap->addr));
 302                 set_beacon++;
 303         }
 304 #endif /* CONFIG_IEEE80211N */
 305
 306         if (set_beacon)
 307                 ieee802_11_update_beacons(iface);
 308 }
 309
 310
 311 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 312 {
 313         struct hostapd_iface *iface = eloop_ctx;
 314         struct os_time now;
 315         struct ap_info *ap;
 316         int set_beacon = 0;
 317
 318         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 319
 320         if (!iface->ap_list)
 321                 return;
 322
 323         os_get_time(&now);
 324
 325         while (iface->ap_list) {
 326                 ap = iface->ap_list->prev;
 327                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 328                     now.sec)
 329                         break;
 330
 331                 ap_free_ap(iface, ap);
 332         }
 333
 334         if (iface->olbc || iface->olbc_ht) {
 335                 int olbc = 0;
 336                 int olbc_ht = 0;
 337
 338                 ap = iface->ap_list;
 339                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 340                         if (ap_list_beacon_olbc(iface, ap))
 341                                 olbc = 1;
 342                         if (!ap->ht_support)
 343                                 olbc_ht = 1;
 344                         ap = ap->next;
 345                 }
 346                 if (!olbc && iface->olbc) {
 347                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 348                         iface->olbc = 0;
 349                         set_beacon++;
 350                 }
 351 #ifdef CONFIG_IEEE80211N
 352                 if (!olbc_ht && iface->olbc_ht) {
 353                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 354                         iface->olbc_ht = 0;
 355                         hostapd_ht_operation_update(iface);
 356                         set_beacon++;
 357                 }
 358 #endif /* CONFIG_IEEE80211N */
 359         }
 360
 361         if (set_beacon)
 362                 ieee802_11_update_beacons(iface);
 363 }
 364
 365
 366 int ap_list_init(struct hostapd_iface *iface)
 367 {
 368         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 369         return 0;
 370 }
 371
 372
 373 void ap_list_deinit(struct hostapd_iface *iface)
 374 {
 375         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 376         hostapd_free_aps(iface);
 377 }