git.maemo.org Git - wpasupplicant/blob - 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 "hostapd.h"
  21 #include "config.h"
  22 #include "ieee802_11.h"
  23 #include "eloop.h"
  24 #include "sta_info.h"
  25 #include "ap_list.h"
  26 #include "hw_features.h"
  27 #include "beacon.h"
  28 #include "drivers/driver.h"
  29
  30
  31 struct ieee80211_frame_info {
  32         u32 version;
  33         u32 length;
  34         u64 mactime;
  35         u64 hosttime;
  36         u32 phytype;
  37         u32 channel;
  38         u32 datarate;
  39         u32 antenna;
  40         u32 priority;
  41         u32 ssi_type;
  42         u32 ssi_signal;
  43         u32 ssi_noise;
  44         u32 preamble;
  45         u32 encoding;
  46
  47         /* Note: this structure is otherwise identical to capture format used
  48          * in linux-wlan-ng, but this additional field is used to provide meta
  49          * data about the frame to hostapd. This was the easiest method for
  50          * providing this information, but this might change in the future. */
  51         u32 msg_type;
  52 } __attribute__ ((packed));
  53
  54
  55 enum ieee80211_phytype {
  56         ieee80211_phytype_fhss_dot11_97  = 1,
  57         ieee80211_phytype_dsss_dot11_97  = 2,
  58         ieee80211_phytype_irbaseband     = 3,
  59         ieee80211_phytype_dsss_dot11_b   = 4,
  60         ieee80211_phytype_pbcc_dot11_b   = 5,
  61         ieee80211_phytype_ofdm_dot11_g   = 6,
  62         ieee80211_phytype_pbcc_dot11_g   = 7,
  63         ieee80211_phytype_ofdm_dot11_a   = 8,
  64         ieee80211_phytype_dsss_dot11_turbog = 255,
  65         ieee80211_phytype_dsss_dot11_turbo = 256,
  66 };
  67
  68
  69 /* AP list is a double linked list with head->prev pointing to the end of the
  70  * list and tail->next = NULL. Entries are moved to the head of the list
  71  * whenever a beacon has been received from the AP in question. The tail entry
  72  * in this link will thus be the least recently used entry. */
  73
  74
  75 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  76 {
  77         int i;
  78
  79         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  80             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  81             iface->conf->channel != ap->channel)
  82                 return 0;
  83
  84         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
  85                 return 1;
  86
  87         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
  88                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
  89                 if (rate == 60 || rate == 90 || rate > 110)
  90                         return 0;
  91         }
  92
  93         return 1;
  94 }
  95
  96
  97 #ifdef CONFIG_IEEE80211N
  98 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
  99                                   struct ap_info *ap)
 100 {
 101         return !ap->ht_support;
 102 }
 103 #endif /* CONFIG_IEEE80211N */
 104
 105
 106 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 107 {
 108         struct ap_info *s;
 109
 110         s = iface->ap_hash[STA_HASH(ap)];
 111         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 112                 s = s->hnext;
 113         return s;
 114 }
 115
 116
 117 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 118 {
 119         if (iface->ap_list) {
 120                 ap->prev = iface->ap_list->prev;
 121                 iface->ap_list->prev = ap;
 122         } else
 123                 ap->prev = ap;
 124         ap->next = iface->ap_list;
 125         iface->ap_list = ap;
 126 }
 127
 128
 129 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 130 {
 131         if (iface->ap_list == ap)
 132                 iface->ap_list = ap->next;
 133         else
 134                 ap->prev->next = ap->next;
 135
 136         if (ap->next)
 137                 ap->next->prev = ap->prev;
 138         else if (iface->ap_list)
 139                 iface->ap_list->prev = ap->prev;
 140 }
 141
 142
 143 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 144                                 struct ap_info *ap)
 145 {
 146         if (iface->ap_iter_list) {
 147                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 148                 iface->ap_iter_list->iter_prev = ap;
 149         } else
 150                 ap->iter_prev = ap;
 151         ap->iter_next = iface->ap_iter_list;
 152         iface->ap_iter_list = ap;
 153 }
 154
 155
 156 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 157                                 struct ap_info *ap)
 158 {
 159         if (iface->ap_iter_list == ap)
 160                 iface->ap_iter_list = ap->iter_next;
 161         else
 162                 ap->iter_prev->iter_next = ap->iter_next;
 163
 164         if (ap->iter_next)
 165                 ap->iter_next->iter_prev = ap->iter_prev;
 166         else if (iface->ap_iter_list)
 167                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 168 }
 169
 170
 171 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 172 {
 173         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 174         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 175 }
 176
 177
 178 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 179 {
 180         struct ap_info *s;
 181
 182         s = iface->ap_hash[STA_HASH(ap->addr)];
 183         if (s == NULL) return;
 184         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 185                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 186                 return;
 187         }
 188
 189         while (s->hnext != NULL &&
 190                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 191                 s = s->hnext;
 192         if (s->hnext != NULL)
 193                 s->hnext = s->hnext->hnext;
 194         else
 195                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 196                        MAC2STR(ap->addr));
 197 }
 198
 199
 200 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 201 {
 202         ap_ap_hash_del(iface, ap);
 203         ap_ap_list_del(iface, ap);
 204         ap_ap_iter_list_del(iface, ap);
 205
 206         iface->num_ap--;
 207         os_free(ap);
 208 }
 209
 210
 211 static void hostapd_free_aps(struct hostapd_iface *iface)
 212 {
 213         struct ap_info *ap, *prev;
 214
 215         ap = iface->ap_list;
 216
 217         while (ap) {
 218                 prev = ap;
 219                 ap = ap->next;
 220                 ap_free_ap(iface, prev);
 221         }
 222
 223         iface->ap_list = NULL;
 224 }
 225
 226
 227 int ap_ap_for_each(struct hostapd_iface *iface,
 228                    int (*func)(struct ap_info *s, void *data), void *data)
 229 {
 230         struct ap_info *s;
 231         int ret = 0;
 232
 233         s = iface->ap_list;
 234
 235         while (s) {
 236                 ret = func(s, data);
 237                 if (ret)
 238                         break;
 239                 s = s->next;
 240         }
 241
 242         return ret;
 243 }
 244
 245
 246 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 247 {
 248         struct ap_info *ap;
 249
 250         ap = os_zalloc(sizeof(struct ap_info));
 251         if (ap == NULL)
 252                 return NULL;
 253
 254         /* initialize AP info data */
 255         os_memcpy(ap->addr, addr, ETH_ALEN);
 256         ap_ap_list_add(iface, ap);
 257         iface->num_ap++;
 258         ap_ap_hash_add(iface, ap);
 259         ap_ap_iter_list_add(iface, ap);
 260
 261         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 262                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 263                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 264                 ap_free_ap(iface, ap->prev);
 265         }
 266
 267         return ap;
 268 }
 269
 270
 271 void ap_list_process_beacon(struct hostapd_iface *iface,
 272                             struct ieee80211_mgmt *mgmt,
 273                             struct ieee802_11_elems *elems,
 274                             struct hostapd_frame_info *fi)
 275 {
 276         struct ap_info *ap;
 277         int new_ap = 0;
 278         size_t len;
 279         int set_beacon = 0;
 280
 281         if (iface->conf->ap_table_max_size < 1)
 282                 return;
 283
 284         ap = ap_get_ap(iface, mgmt->bssid);
 285         if (!ap) {
 286                 ap = ap_ap_add(iface, mgmt->bssid);
 287                 if (!ap) {
 288                         printf("Failed to allocate AP information entry\n");
 289                         return;
 290                 }
 291                 new_ap = 1;
 292         }
 293
 294         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 295         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 296
 297         if (elems->ssid) {
 298                 len = elems->ssid_len;
 299                 if (len >= sizeof(ap->ssid))
 300                         len = sizeof(ap->ssid) - 1;
 301                 os_memcpy(ap->ssid, elems->ssid, len);
 302                 ap->ssid[len] = '\0';
 303                 ap->ssid_len = len;
 304         }
 305
 306         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 307         len = 0;
 308         if (elems->supp_rates) {
 309                 len = elems->supp_rates_len;
 310                 if (len > WLAN_SUPP_RATES_MAX)
 311                         len = WLAN_SUPP_RATES_MAX;
 312                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 313         }
 314         if (elems->ext_supp_rates) {
 315                 int len2;
 316                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 317                         len2 = WLAN_SUPP_RATES_MAX - len;
 318                 else
 319                         len2 = elems->ext_supp_rates_len;
 320                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 321                           len2);
 322         }
 323
 324         ap->wpa = elems->wpa_ie != NULL;
 325
 326         if (elems->erp_info && elems->erp_info_len == 1)
 327                 ap->erp = elems->erp_info[0];
 328         else
 329                 ap->erp = -1;
 330
 331         if (elems->ds_params && elems->ds_params_len == 1)
 332                 ap->channel = elems->ds_params[0];
 333         else if (fi)
 334                 ap->channel = fi->channel;
 335
 336         if (elems->ht_capabilities)
 337                 ap->ht_support = 1;
 338         else
 339                 ap->ht_support = 0;
 340
 341         ap->num_beacons++;
 342         time(&ap->last_beacon);
 343         if (fi) {
 344                 ap->phytype = fi->phytype;
 345                 ap->ssi_signal = fi->ssi_signal;
 346                 ap->datarate = fi->datarate;
 347         }
 348
 349         if (!new_ap && ap != iface->ap_list) {
 350                 /* move AP entry into the beginning of the list so that the
 351                  * oldest entry is always in the end of the list */
 352                 ap_ap_list_del(iface, ap);
 353                 ap_ap_list_add(iface, ap);
 354         }
 355
 356         if (!iface->olbc &&
 357             ap_list_beacon_olbc(iface, ap)) {
 358                 iface->olbc = 1;
 359                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 360                            "protection", MAC2STR(ap->addr));
 361                 set_beacon++;
 362         }
 363
 364 #ifdef CONFIG_IEEE80211N
 365         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 366                 iface->olbc_ht = 1;
 367                 hostapd_ht_operation_update(iface);
 368                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 369                            " - enable protection", MAC2STR(ap->addr));
 370                 set_beacon++;
 371         }
 372 #endif /* CONFIG_IEEE80211N */
 373
 374         if (set_beacon)
 375                 ieee802_11_set_beacons(iface);
 376 }
 377
 378
 379 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 380 {
 381         struct hostapd_iface *iface = eloop_ctx;
 382         time_t now;
 383         struct ap_info *ap;
 384         int set_beacon = 0;
 385
 386         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 387
 388         if (!iface->ap_list)
 389                 return;
 390
 391         time(&now);
 392
 393         while (iface->ap_list) {
 394                 ap = iface->ap_list->prev;
 395                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 396                     now)
 397                         break;
 398
 399                 ap_free_ap(iface, ap);
 400         }
 401
 402         if (iface->olbc || iface->olbc_ht) {
 403                 int olbc = 0;
 404                 int olbc_ht = 0;
 405
 406                 ap = iface->ap_list;
 407                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 408                         if (ap_list_beacon_olbc(iface, ap))
 409                                 olbc = 1;
 410 #ifdef CONFIG_IEEE80211N
 411                         if (ap_list_beacon_olbc_ht(iface, ap))
 412                                 olbc_ht = 1;
 413 #endif /* CONFIG_IEEE80211N */
 414                         ap = ap->next;
 415                 }
 416                 if (!olbc && iface->olbc) {
 417                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 418                         iface->olbc = 0;
 419                         set_beacon++;
 420                 }
 421 #ifdef CONFIG_IEEE80211N
 422                 if (!olbc_ht && iface->olbc_ht) {
 423                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 424                         iface->olbc_ht = 0;
 425                         hostapd_ht_operation_update(iface);
 426                         set_beacon++;
 427                 }
 428 #endif /* CONFIG_IEEE80211N */
 429         }
 430
 431         if (set_beacon)
 432                 ieee802_11_set_beacons(iface);
 433 }
 434
 435
 436 int ap_list_init(struct hostapd_iface *iface)
 437 {
 438         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 439         return 0;
 440 }
 441
 442
 443 void ap_list_deinit(struct hostapd_iface *iface)
 444 {
 445         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 446         hostapd_free_aps(iface);
 447 }
 448
 449
 450 int ap_list_reconfig(struct hostapd_iface *iface,
 451                      struct hostapd_config *oldconf)
 452 {
 453         time_t now;
 454         struct ap_info *ap;
 455
 456         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 457             iface->conf->ap_table_expiration_time ==
 458             oldconf->ap_table_expiration_time)
 459                 return 0;
 460
 461         time(&now);
 462
 463         while (iface->ap_list) {
 464                 ap = iface->ap_list->prev;
 465                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 466                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 467                     now)
 468                         break;
 469
 470                 ap_free_ap(iface, iface->ap_list->prev);
 471         }
 472
 473         return 0;
 474 }