vcs.maemo.org Git - wpasupplicant/blob - hostapd/ap_list.c

   1 /*
   2  * hostapd / AP table
   3  * Copyright 2002-2003, Jouni Malinen <j@w1.fi>
   4  * Copyright 2003-2004, Instant802 Networks, Inc.
   5  * Copyright 2006, Devicescape Software, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * Alternatively, this software may be distributed under the terms of BSD
  12  * license.
  13  *
  14  * See README and COPYING for more details.
  15  */
  16
  17 #include "includes.h"
  18
  19 #include "hostapd.h"
  20 #include "ieee802_11.h"
  21 #include "eloop.h"
  22 #include "ap_list.h"
  23 #include "hw_features.h"
  24 #include "beacon.h"
  25
  26
  27 struct ieee80211_frame_info {
  28         u32 version;
  29         u32 length;
  30         u64 mactime;
  31         u64 hosttime;
  32         u32 phytype;
  33         u32 channel;
  34         u32 datarate;
  35         u32 antenna;
  36         u32 priority;
  37         u32 ssi_type;
  38         u32 ssi_signal;
  39         u32 ssi_noise;
  40         u32 preamble;
  41         u32 encoding;
  42
  43         /* Note: this structure is otherwise identical to capture format used
  44          * in linux-wlan-ng, but this additional field is used to provide meta
  45          * data about the frame to hostapd. This was the easiest method for
  46          * providing this information, but this might change in the future. */
  47         u32 msg_type;
  48 } __attribute__ ((packed));
  49
  50
  51 enum ieee80211_phytype {
  52         ieee80211_phytype_fhss_dot11_97  = 1,
  53         ieee80211_phytype_dsss_dot11_97  = 2,
  54         ieee80211_phytype_irbaseband     = 3,
  55         ieee80211_phytype_dsss_dot11_b   = 4,
  56         ieee80211_phytype_pbcc_dot11_b   = 5,
  57         ieee80211_phytype_ofdm_dot11_g   = 6,
  58         ieee80211_phytype_pbcc_dot11_g   = 7,
  59         ieee80211_phytype_ofdm_dot11_a   = 8,
  60         ieee80211_phytype_dsss_dot11_turbog = 255,
  61         ieee80211_phytype_dsss_dot11_turbo = 256,
  62 };
  63
  64
  65 /* AP list is a double linked list with head->prev pointing to the end of the
  66  * list and tail->next = NULL. Entries are moved to the head of the list
  67  * whenever a beacon has been received from the AP in question. The tail entry
  68  * in this link will thus be the least recently used entry. */
  69
  70
  71 static void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
  72 {
  73         wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
  74
  75         /* TODO: could send a notification message to an external program that
  76          * would then determine whether a rogue AP has been detected */
  77 }
  78
  79
  80 static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
  81 {
  82         wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
  83
  84         /* TODO: could send a notification message to an external program */
  85 }
  86
  87
  88 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  89 {
  90         int i;
  91
  92         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  93             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  94             iface->conf->channel != ap->channel)
  95                 return 0;
  96
  97         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
  98                 return 1;
  99
 100         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
 101                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
 102                 if (rate == 60 || rate == 90 || rate > 110)
 103                         return 0;
 104         }
 105
 106         return 1;
 107 }
 108
 109
 110 #ifdef CONFIG_IEEE80211N
 111 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 112                                   struct ap_info *ap)
 113 {
 114         return !ap->ht_support;
 115 }
 116 #endif /* CONFIG_IEEE80211N */
 117
 118
 119 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 120 {
 121         struct ap_info *s;
 122
 123         s = iface->ap_hash[STA_HASH(ap)];
 124         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 125                 s = s->hnext;
 126         return s;
 127 }
 128
 129
 130 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 131 {
 132         if (iface->ap_list) {
 133                 ap->prev = iface->ap_list->prev;
 134                 iface->ap_list->prev = ap;
 135         } else
 136                 ap->prev = ap;
 137         ap->next = iface->ap_list;
 138         iface->ap_list = ap;
 139 }
 140
 141
 142 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 143 {
 144         if (iface->ap_list == ap)
 145                 iface->ap_list = ap->next;
 146         else
 147                 ap->prev->next = ap->next;
 148
 149         if (ap->next)
 150                 ap->next->prev = ap->prev;
 151         else if (iface->ap_list)
 152                 iface->ap_list->prev = ap->prev;
 153 }
 154
 155
 156 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 157                                 struct ap_info *ap)
 158 {
 159         if (iface->ap_iter_list) {
 160                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 161                 iface->ap_iter_list->iter_prev = ap;
 162         } else
 163                 ap->iter_prev = ap;
 164         ap->iter_next = iface->ap_iter_list;
 165         iface->ap_iter_list = ap;
 166 }
 167
 168
 169 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 170                                 struct ap_info *ap)
 171 {
 172         if (iface->ap_iter_list == ap)
 173                 iface->ap_iter_list = ap->iter_next;
 174         else
 175                 ap->iter_prev->iter_next = ap->iter_next;
 176
 177         if (ap->iter_next)
 178                 ap->iter_next->iter_prev = ap->iter_prev;
 179         else if (iface->ap_iter_list)
 180                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 181 }
 182
 183
 184 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 185 {
 186         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 187         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 188 }
 189
 190
 191 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 192 {
 193         struct ap_info *s;
 194
 195         s = iface->ap_hash[STA_HASH(ap->addr)];
 196         if (s == NULL) return;
 197         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 198                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 199                 return;
 200         }
 201
 202         while (s->hnext != NULL &&
 203                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 204                 s = s->hnext;
 205         if (s->hnext != NULL)
 206                 s->hnext = s->hnext->hnext;
 207         else
 208                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 209                        MAC2STR(ap->addr));
 210 }
 211
 212
 213 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 214 {
 215         ap_ap_hash_del(iface, ap);
 216         ap_ap_list_del(iface, ap);
 217         ap_ap_iter_list_del(iface, ap);
 218
 219         iface->num_ap--;
 220         os_free(ap);
 221 }
 222
 223
 224 static void hostapd_free_aps(struct hostapd_iface *iface)
 225 {
 226         struct ap_info *ap, *prev;
 227
 228         ap = iface->ap_list;
 229
 230         while (ap) {
 231                 prev = ap;
 232                 ap = ap->next;
 233                 ap_free_ap(iface, prev);
 234         }
 235
 236         iface->ap_list = NULL;
 237 }
 238
 239
 240 int ap_ap_for_each(struct hostapd_iface *iface,
 241                    int (*func)(struct ap_info *s, void *data), void *data)
 242 {
 243         struct ap_info *s;
 244         int ret = 0;
 245
 246         s = iface->ap_list;
 247
 248         while (s) {
 249                 ret = func(s, data);
 250                 if (ret)
 251                         break;
 252                 s = s->next;
 253         }
 254
 255         return ret;
 256 }
 257
 258
 259 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 260 {
 261         struct ap_info *ap;
 262
 263         ap = os_zalloc(sizeof(struct ap_info));
 264         if (ap == NULL)
 265                 return NULL;
 266
 267         /* initialize AP info data */
 268         os_memcpy(ap->addr, addr, ETH_ALEN);
 269         ap_ap_list_add(iface, ap);
 270         iface->num_ap++;
 271         ap_ap_hash_add(iface, ap);
 272         ap_ap_iter_list_add(iface, ap);
 273
 274         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 275                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 276                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 277                 if (iface->conf->passive_scan_interval > 0)
 278                         ap_list_expired_ap(iface, ap->prev);
 279                 ap_free_ap(iface, ap->prev);
 280         }
 281
 282         return ap;
 283 }
 284
 285
 286 void ap_list_process_beacon(struct hostapd_iface *iface,
 287                             struct ieee80211_mgmt *mgmt,
 288                             struct ieee802_11_elems *elems,
 289                             struct hostapd_frame_info *fi)
 290 {
 291         struct ap_info *ap;
 292         int new_ap = 0;
 293         size_t len;
 294         int set_beacon = 0;
 295
 296         if (iface->conf->ap_table_max_size < 1)
 297                 return;
 298
 299         ap = ap_get_ap(iface, mgmt->bssid);
 300         if (!ap) {
 301                 ap = ap_ap_add(iface, mgmt->bssid);
 302                 if (!ap) {
 303                         printf("Failed to allocate AP information entry\n");
 304                         return;
 305                 }
 306                 new_ap = 1;
 307         }
 308
 309         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 310         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 311
 312         if (elems->ssid) {
 313                 len = elems->ssid_len;
 314                 if (len >= sizeof(ap->ssid))
 315                         len = sizeof(ap->ssid) - 1;
 316                 os_memcpy(ap->ssid, elems->ssid, len);
 317                 ap->ssid[len] = '\0';
 318                 ap->ssid_len = len;
 319         }
 320
 321         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 322         len = 0;
 323         if (elems->supp_rates) {
 324                 len = elems->supp_rates_len;
 325                 if (len > WLAN_SUPP_RATES_MAX)
 326                         len = WLAN_SUPP_RATES_MAX;
 327                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 328         }
 329         if (elems->ext_supp_rates) {
 330                 int len2;
 331                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 332                         len2 = WLAN_SUPP_RATES_MAX - len;
 333                 else
 334                         len2 = elems->ext_supp_rates_len;
 335                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 336                           len2);
 337         }
 338
 339         ap->wpa = elems->wpa_ie != NULL;
 340
 341         if (elems->erp_info && elems->erp_info_len == 1)
 342                 ap->erp = elems->erp_info[0];
 343         else
 344                 ap->erp = -1;
 345
 346         if (elems->ds_params && elems->ds_params_len == 1)
 347                 ap->channel = elems->ds_params[0];
 348         else if (fi)
 349                 ap->channel = fi->channel;
 350
 351         if (elems->ht_capabilities)
 352                 ap->ht_support = 1;
 353         else
 354                 ap->ht_support = 0;
 355
 356         ap->num_beacons++;
 357         time(&ap->last_beacon);
 358         if (fi) {
 359                 ap->phytype = fi->phytype;
 360                 ap->ssi_signal = fi->ssi_signal;
 361                 ap->datarate = fi->datarate;
 362         }
 363
 364         if (new_ap) {
 365                 if (iface->conf->passive_scan_interval > 0)
 366                         ap_list_new_ap(iface, ap);
 367         } else if (ap != iface->ap_list) {
 368                 /* move AP entry into the beginning of the list so that the
 369                  * oldest entry is always in the end of the list */
 370                 ap_ap_list_del(iface, ap);
 371                 ap_ap_list_add(iface, ap);
 372         }
 373
 374         if (!iface->olbc &&
 375             ap_list_beacon_olbc(iface, ap)) {
 376                 iface->olbc = 1;
 377                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 378                            "protection", MAC2STR(ap->addr));
 379                 set_beacon++;
 380         }
 381
 382 #ifdef CONFIG_IEEE80211N
 383         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 384                 iface->olbc_ht = 1;
 385                 hostapd_ht_operation_update(iface);
 386                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 387                            " - enable protection", MAC2STR(ap->addr));
 388                 set_beacon++;
 389         }
 390 #endif /* CONFIG_IEEE80211N */
 391
 392         if (set_beacon)
 393                 ieee802_11_set_beacons(iface);
 394 }
 395
 396
 397 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 398 {
 399         struct hostapd_iface *iface = eloop_ctx;
 400         time_t now;
 401         struct ap_info *ap;
 402         int set_beacon = 0;
 403
 404         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 405
 406         if (!iface->ap_list)
 407                 return;
 408
 409         time(&now);
 410
 411         /* FIX: it looks like jkm-Purina ended up in busy loop in this
 412          * function. Apparently, something can still cause a loop in the AP
 413          * list.. */
 414
 415         while (iface->ap_list) {
 416                 ap = iface->ap_list->prev;
 417                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 418                     now)
 419                         break;
 420
 421                 if (iface->conf->passive_scan_interval > 0)
 422                         ap_list_expired_ap(iface, ap);
 423                 ap_free_ap(iface, ap);
 424         }
 425
 426         if (iface->olbc || iface->olbc_ht) {
 427                 int olbc = 0;
 428                 int olbc_ht = 0;
 429
 430                 ap = iface->ap_list;
 431                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 432                         if (ap_list_beacon_olbc(iface, ap))
 433                                 olbc = 1;
 434 #ifdef CONFIG_IEEE80211N
 435                         if (ap_list_beacon_olbc_ht(iface, ap))
 436                                 olbc_ht = 1;
 437 #endif /* CONFIG_IEEE80211N */
 438                         ap = ap->next;
 439                 }
 440                 if (!olbc && iface->olbc) {
 441                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 442                         iface->olbc = 0;
 443                         set_beacon++;
 444                 }
 445 #ifdef CONFIG_IEEE80211N
 446                 if (!olbc_ht && iface->olbc_ht) {
 447                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 448                         iface->olbc_ht = 0;
 449                         hostapd_ht_operation_update(iface);
 450                         set_beacon++;
 451                 }
 452 #endif /* CONFIG_IEEE80211N */
 453         }
 454
 455         if (set_beacon)
 456                 ieee802_11_set_beacons(iface);
 457 }
 458
 459
 460 int ap_list_init(struct hostapd_iface *iface)
 461 {
 462         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 463         return 0;
 464 }
 465
 466
 467 void ap_list_deinit(struct hostapd_iface *iface)
 468 {
 469         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 470         hostapd_free_aps(iface);
 471 }
 472
 473
 474 int ap_list_reconfig(struct hostapd_iface *iface,
 475                      struct hostapd_config *oldconf)
 476 {
 477         time_t now;
 478         struct ap_info *ap;
 479
 480         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 481             iface->conf->ap_table_expiration_time ==
 482             oldconf->ap_table_expiration_time)
 483                 return 0;
 484
 485         time(&now);
 486
 487         while (iface->ap_list) {
 488                 ap = iface->ap_list->prev;
 489                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 490                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 491                     now)
 492                         break;
 493
 494                 if (iface->conf->passive_scan_interval > 0)
 495                         ap_list_expired_ap(iface, iface->ap_list->prev);
 496                 ap_free_ap(iface, iface->ap_list->prev);
 497         }
 498
 499         return 0;
 500 }