hostapd/ap_list.c

   1 /*
   2  * hostapd / AP table
   3  * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 2003-2004, Instant802 Networks, Inc.
   5  * Copyright (c) 2006, Devicescape Software, Inc.
   6  * Copyright (c) 2007-2008, Intel Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Alternatively, this software may be distributed under the terms of BSD
  13  * license.
  14  *
  15  * See README and COPYING for more details.
  16  */
  17
  18 #include "includes.h"
  19
  20 #include "common.h"
  21 #include "hostapd.h"
  22 #include "config.h"
  23 #include "ieee802_11.h"
  24 #include "eloop.h"
  25 #include "sta_info.h"
  26 #include "ap_list.h"
  27 #include "hw_features.h"
  28 #include "beacon.h"
  29 #include "drivers/driver.h"
  30
  31
  32 struct ieee80211_frame_info {
  33         u32 version;
  34         u32 length;
  35         u64 mactime;
  36         u64 hosttime;
  37         u32 phytype;
  38         u32 channel;
  39         u32 datarate;
  40         u32 antenna;
  41         u32 priority;
  42         u32 ssi_type;
  43         u32 ssi_signal;
  44         u32 ssi_noise;
  45         u32 preamble;
  46         u32 encoding;
  47
  48         /* Note: this structure is otherwise identical to capture format used
  49          * in linux-wlan-ng, but this additional field is used to provide meta
  50          * data about the frame to hostapd. This was the easiest method for
  51          * providing this information, but this might change in the future. */
  52         u32 msg_type;
  53 } __attribute__ ((packed));
  54
  55
  56 enum ieee80211_phytype {
  57         ieee80211_phytype_fhss_dot11_97  = 1,
  58         ieee80211_phytype_dsss_dot11_97  = 2,
  59         ieee80211_phytype_irbaseband     = 3,
  60         ieee80211_phytype_dsss_dot11_b   = 4,
  61         ieee80211_phytype_pbcc_dot11_b   = 5,
  62         ieee80211_phytype_ofdm_dot11_g   = 6,
  63         ieee80211_phytype_pbcc_dot11_g   = 7,
  64         ieee80211_phytype_ofdm_dot11_a   = 8,
  65         ieee80211_phytype_dsss_dot11_turbog = 255,
  66         ieee80211_phytype_dsss_dot11_turbo = 256,
  67 };
  68
  69
  70 /* AP list is a double linked list with head->prev pointing to the end of the
  71  * list and tail->next = NULL. Entries are moved to the head of the list
  72  * whenever a beacon has been received from the AP in question. The tail entry
  73  * in this link will thus be the least recently used entry. */
  74
  75
  76 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  77 {
  78         int i;
  79
  80         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  81             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  82             iface->conf->channel != ap->channel)
  83                 return 0;
  84
  85         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
  86                 return 1;
  87
  88         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
  89                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
  90                 if (rate == 60 || rate == 90 || rate > 110)
  91                         return 0;
  92         }
  93
  94         return 1;
  95 }
  96
  97
  98 #ifdef CONFIG_IEEE80211N
  99 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 100                                   struct ap_info *ap)
 101 {
 102         return !ap->ht_support;
 103 }
 104 #endif /* CONFIG_IEEE80211N */
 105
 106
 107 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 108 {
 109         struct ap_info *s;
 110
 111         s = iface->ap_hash[STA_HASH(ap)];
 112         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 113                 s = s->hnext;
 114         return s;
 115 }
 116
 117
 118 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 119 {
 120         if (iface->ap_list) {
 121                 ap->prev = iface->ap_list->prev;
 122                 iface->ap_list->prev = ap;
 123         } else
 124                 ap->prev = ap;
 125         ap->next = iface->ap_list;
 126         iface->ap_list = ap;
 127 }
 128
 129
 130 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 131 {
 132         if (iface->ap_list == ap)
 133                 iface->ap_list = ap->next;
 134         else
 135                 ap->prev->next = ap->next;
 136
 137         if (ap->next)
 138                 ap->next->prev = ap->prev;
 139         else if (iface->ap_list)
 140                 iface->ap_list->prev = ap->prev;
 141 }
 142
 143
 144 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 145                                 struct ap_info *ap)
 146 {
 147         if (iface->ap_iter_list) {
 148                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 149                 iface->ap_iter_list->iter_prev = ap;
 150         } else
 151                 ap->iter_prev = ap;
 152         ap->iter_next = iface->ap_iter_list;
 153         iface->ap_iter_list = ap;
 154 }
 155
 156
 157 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 158                                 struct ap_info *ap)
 159 {
 160         if (iface->ap_iter_list == ap)
 161                 iface->ap_iter_list = ap->iter_next;
 162         else
 163                 ap->iter_prev->iter_next = ap->iter_next;
 164
 165         if (ap->iter_next)
 166                 ap->iter_next->iter_prev = ap->iter_prev;
 167         else if (iface->ap_iter_list)
 168                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 169 }
 170
 171
 172 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 173 {
 174         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 175         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 176 }
 177
 178
 179 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 180 {
 181         struct ap_info *s;
 182
 183         s = iface->ap_hash[STA_HASH(ap->addr)];
 184         if (s == NULL) return;
 185         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 186                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 187                 return;
 188         }
 189
 190         while (s->hnext != NULL &&
 191                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 192                 s = s->hnext;
 193         if (s->hnext != NULL)
 194                 s->hnext = s->hnext->hnext;
 195         else
 196                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 197                        MAC2STR(ap->addr));
 198 }
 199
 200
 201 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 202 {
 203         ap_ap_hash_del(iface, ap);
 204         ap_ap_list_del(iface, ap);
 205         ap_ap_iter_list_del(iface, ap);
 206
 207         iface->num_ap--;
 208         os_free(ap);
 209 }
 210
 211
 212 static void hostapd_free_aps(struct hostapd_iface *iface)
 213 {
 214         struct ap_info *ap, *prev;
 215
 216         ap = iface->ap_list;
 217
 218         while (ap) {
 219                 prev = ap;
 220                 ap = ap->next;
 221                 ap_free_ap(iface, prev);
 222         }
 223
 224         iface->ap_list = NULL;
 225 }
 226
 227
 228 int ap_ap_for_each(struct hostapd_iface *iface,
 229                    int (*func)(struct ap_info *s, void *data), void *data)
 230 {
 231         struct ap_info *s;
 232         int ret = 0;
 233
 234         s = iface->ap_list;
 235
 236         while (s) {
 237                 ret = func(s, data);
 238                 if (ret)
 239                         break;
 240                 s = s->next;
 241         }
 242
 243         return ret;
 244 }
 245
 246
 247 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 248 {
 249         struct ap_info *ap;
 250
 251         ap = os_zalloc(sizeof(struct ap_info));
 252         if (ap == NULL)
 253                 return NULL;
 254
 255         /* initialize AP info data */
 256         os_memcpy(ap->addr, addr, ETH_ALEN);
 257         ap_ap_list_add(iface, ap);
 258         iface->num_ap++;
 259         ap_ap_hash_add(iface, ap);
 260         ap_ap_iter_list_add(iface, ap);
 261
 262         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 263                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 264                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 265                 ap_free_ap(iface, ap->prev);
 266         }
 267
 268         return ap;
 269 }
 270
 271
 272 void ap_list_process_beacon(struct hostapd_iface *iface,
 273                             struct ieee80211_mgmt *mgmt,
 274                             struct ieee802_11_elems *elems,
 275                             struct hostapd_frame_info *fi)
 276 {
 277         struct ap_info *ap;
 278         int new_ap = 0;
 279         size_t len;
 280         int set_beacon = 0;
 281
 282         if (iface->conf->ap_table_max_size < 1)
 283                 return;
 284
 285         ap = ap_get_ap(iface, mgmt->bssid);
 286         if (!ap) {
 287                 ap = ap_ap_add(iface, mgmt->bssid);
 288                 if (!ap) {
 289                         printf("Failed to allocate AP information entry\n");
 290                         return;
 291                 }
 292                 new_ap = 1;
 293         }
 294
 295         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 296         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 297
 298         if (elems->ssid) {
 299                 len = elems->ssid_len;
 300                 if (len >= sizeof(ap->ssid))
 301                         len = sizeof(ap->ssid) - 1;
 302                 os_memcpy(ap->ssid, elems->ssid, len);
 303                 ap->ssid[len] = '\0';
 304                 ap->ssid_len = len;
 305         }
 306
 307         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 308         len = 0;
 309         if (elems->supp_rates) {
 310                 len = elems->supp_rates_len;
 311                 if (len > WLAN_SUPP_RATES_MAX)
 312                         len = WLAN_SUPP_RATES_MAX;
 313                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 314         }
 315         if (elems->ext_supp_rates) {
 316                 int len2;
 317                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 318                         len2 = WLAN_SUPP_RATES_MAX - len;
 319                 else
 320                         len2 = elems->ext_supp_rates_len;
 321                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 322                           len2);
 323         }
 324
 325         ap->wpa = elems->wpa_ie != NULL;
 326
 327         if (elems->erp_info && elems->erp_info_len == 1)
 328                 ap->erp = elems->erp_info[0];
 329         else
 330                 ap->erp = -1;
 331
 332         if (elems->ds_params && elems->ds_params_len == 1)
 333                 ap->channel = elems->ds_params[0];
 334         else if (fi)
 335                 ap->channel = fi->channel;
 336
 337         if (elems->ht_capabilities)
 338                 ap->ht_support = 1;
 339         else
 340                 ap->ht_support = 0;
 341
 342         ap->num_beacons++;
 343         time(&ap->last_beacon);
 344         if (fi) {
 345                 ap->phytype = fi->phytype;
 346                 ap->ssi_signal = fi->ssi_signal;
 347                 ap->datarate = fi->datarate;
 348         }
 349
 350         if (!new_ap && ap != iface->ap_list) {
 351                 /* move AP entry into the beginning of the list so that the
 352                  * oldest entry is always in the end of the list */
 353                 ap_ap_list_del(iface, ap);
 354                 ap_ap_list_add(iface, ap);
 355         }
 356
 357         if (!iface->olbc &&
 358             ap_list_beacon_olbc(iface, ap)) {
 359                 iface->olbc = 1;
 360                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 361                            "protection", MAC2STR(ap->addr));
 362                 set_beacon++;
 363         }
 364
 365 #ifdef CONFIG_IEEE80211N
 366         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 367                 iface->olbc_ht = 1;
 368                 hostapd_ht_operation_update(iface);
 369                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 370                            " - enable protection", MAC2STR(ap->addr));
 371                 set_beacon++;
 372         }
 373 #endif /* CONFIG_IEEE80211N */
 374
 375         if (set_beacon)
 376                 ieee802_11_set_beacons(iface);
 377 }
 378
 379
 380 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 381 {
 382         struct hostapd_iface *iface = eloop_ctx;
 383         time_t now;
 384         struct ap_info *ap;
 385         int set_beacon = 0;
 386
 387         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 388
 389         if (!iface->ap_list)
 390                 return;
 391
 392         time(&now);
 393
 394         while (iface->ap_list) {
 395                 ap = iface->ap_list->prev;
 396                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 397                     now)
 398                         break;
 399
 400                 ap_free_ap(iface, ap);
 401         }
 402
 403         if (iface->olbc || iface->olbc_ht) {
 404                 int olbc = 0;
 405                 int olbc_ht = 0;
 406
 407                 ap = iface->ap_list;
 408                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 409                         if (ap_list_beacon_olbc(iface, ap))
 410                                 olbc = 1;
 411 #ifdef CONFIG_IEEE80211N
 412                         if (ap_list_beacon_olbc_ht(iface, ap))
 413                                 olbc_ht = 1;
 414 #endif /* CONFIG_IEEE80211N */
 415                         ap = ap->next;
 416                 }
 417                 if (!olbc && iface->olbc) {
 418                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 419                         iface->olbc = 0;
 420                         set_beacon++;
 421                 }
 422 #ifdef CONFIG_IEEE80211N
 423                 if (!olbc_ht && iface->olbc_ht) {
 424                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 425                         iface->olbc_ht = 0;
 426                         hostapd_ht_operation_update(iface);
 427                         set_beacon++;
 428                 }
 429 #endif /* CONFIG_IEEE80211N */
 430         }
 431
 432         if (set_beacon)
 433                 ieee802_11_set_beacons(iface);
 434 }
 435
 436
 437 int ap_list_init(struct hostapd_iface *iface)
 438 {
 439         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 440         return 0;
 441 }
 442
 443
 444 void ap_list_deinit(struct hostapd_iface *iface)
 445 {
 446         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 447         hostapd_free_aps(iface);
 448 }