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 "ieee802_11.h"
  22 #include "eloop.h"
  23 #include "ap_list.h"
  24 #include "hw_features.h"
  25 #include "beacon.h"
  26 #include "driver.h"
  27
  28
  29 struct ieee80211_frame_info {
  30         u32 version;
  31         u32 length;
  32         u64 mactime;
  33         u64 hosttime;
  34         u32 phytype;
  35         u32 channel;
  36         u32 datarate;
  37         u32 antenna;
  38         u32 priority;
  39         u32 ssi_type;
  40         u32 ssi_signal;
  41         u32 ssi_noise;
  42         u32 preamble;
  43         u32 encoding;
  44
  45         /* Note: this structure is otherwise identical to capture format used
  46          * in linux-wlan-ng, but this additional field is used to provide meta
  47          * data about the frame to hostapd. This was the easiest method for
  48          * providing this information, but this might change in the future. */
  49         u32 msg_type;
  50 } __attribute__ ((packed));
  51
  52
  53 enum ieee80211_phytype {
  54         ieee80211_phytype_fhss_dot11_97  = 1,
  55         ieee80211_phytype_dsss_dot11_97  = 2,
  56         ieee80211_phytype_irbaseband     = 3,
  57         ieee80211_phytype_dsss_dot11_b   = 4,
  58         ieee80211_phytype_pbcc_dot11_b   = 5,
  59         ieee80211_phytype_ofdm_dot11_g   = 6,
  60         ieee80211_phytype_pbcc_dot11_g   = 7,
  61         ieee80211_phytype_ofdm_dot11_a   = 8,
  62         ieee80211_phytype_dsss_dot11_turbog = 255,
  63         ieee80211_phytype_dsss_dot11_turbo = 256,
  64 };
  65
  66
  67 /* AP list is a double linked list with head->prev pointing to the end of the
  68  * list and tail->next = NULL. Entries are moved to the head of the list
  69  * whenever a beacon has been received from the AP in question. The tail entry
  70  * in this link will thus be the least recently used entry. */
  71
  72
  73 static void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
  74 {
  75         wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
  76
  77         /* TODO: could send a notification message to an external program that
  78          * would then determine whether a rogue AP has been detected */
  79 }
  80
  81
  82 static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
  83 {
  84         wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
  85
  86         /* TODO: could send a notification message to an external program */
  87 }
  88
  89
  90 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  91 {
  92         int i;
  93
  94         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  95             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  96             iface->conf->channel != ap->channel)
  97                 return 0;
  98
  99         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
 100                 return 1;
 101
 102         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
 103                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
 104                 if (rate == 60 || rate == 90 || rate > 110)
 105                         return 0;
 106         }
 107
 108         return 1;
 109 }
 110
 111
 112 #ifdef CONFIG_IEEE80211N
 113 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 114                                   struct ap_info *ap)
 115 {
 116         return !ap->ht_support;
 117 }
 118 #endif /* CONFIG_IEEE80211N */
 119
 120
 121 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 122 {
 123         struct ap_info *s;
 124
 125         s = iface->ap_hash[STA_HASH(ap)];
 126         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 127                 s = s->hnext;
 128         return s;
 129 }
 130
 131
 132 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 133 {
 134         if (iface->ap_list) {
 135                 ap->prev = iface->ap_list->prev;
 136                 iface->ap_list->prev = ap;
 137         } else
 138                 ap->prev = ap;
 139         ap->next = iface->ap_list;
 140         iface->ap_list = ap;
 141 }
 142
 143
 144 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 145 {
 146         if (iface->ap_list == ap)
 147                 iface->ap_list = ap->next;
 148         else
 149                 ap->prev->next = ap->next;
 150
 151         if (ap->next)
 152                 ap->next->prev = ap->prev;
 153         else if (iface->ap_list)
 154                 iface->ap_list->prev = ap->prev;
 155 }
 156
 157
 158 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 159                                 struct ap_info *ap)
 160 {
 161         if (iface->ap_iter_list) {
 162                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 163                 iface->ap_iter_list->iter_prev = ap;
 164         } else
 165                 ap->iter_prev = ap;
 166         ap->iter_next = iface->ap_iter_list;
 167         iface->ap_iter_list = ap;
 168 }
 169
 170
 171 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 172                                 struct ap_info *ap)
 173 {
 174         if (iface->ap_iter_list == ap)
 175                 iface->ap_iter_list = ap->iter_next;
 176         else
 177                 ap->iter_prev->iter_next = ap->iter_next;
 178
 179         if (ap->iter_next)
 180                 ap->iter_next->iter_prev = ap->iter_prev;
 181         else if (iface->ap_iter_list)
 182                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 183 }
 184
 185
 186 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 187 {
 188         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 189         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 190 }
 191
 192
 193 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 194 {
 195         struct ap_info *s;
 196
 197         s = iface->ap_hash[STA_HASH(ap->addr)];
 198         if (s == NULL) return;
 199         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 200                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 201                 return;
 202         }
 203
 204         while (s->hnext != NULL &&
 205                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 206                 s = s->hnext;
 207         if (s->hnext != NULL)
 208                 s->hnext = s->hnext->hnext;
 209         else
 210                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 211                        MAC2STR(ap->addr));
 212 }
 213
 214
 215 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 216 {
 217         ap_ap_hash_del(iface, ap);
 218         ap_ap_list_del(iface, ap);
 219         ap_ap_iter_list_del(iface, ap);
 220
 221         iface->num_ap--;
 222         os_free(ap);
 223 }
 224
 225
 226 static void hostapd_free_aps(struct hostapd_iface *iface)
 227 {
 228         struct ap_info *ap, *prev;
 229
 230         ap = iface->ap_list;
 231
 232         while (ap) {
 233                 prev = ap;
 234                 ap = ap->next;
 235                 ap_free_ap(iface, prev);
 236         }
 237
 238         iface->ap_list = NULL;
 239 }
 240
 241
 242 int ap_ap_for_each(struct hostapd_iface *iface,
 243                    int (*func)(struct ap_info *s, void *data), void *data)
 244 {
 245         struct ap_info *s;
 246         int ret = 0;
 247
 248         s = iface->ap_list;
 249
 250         while (s) {
 251                 ret = func(s, data);
 252                 if (ret)
 253                         break;
 254                 s = s->next;
 255         }
 256
 257         return ret;
 258 }
 259
 260
 261 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 262 {
 263         struct ap_info *ap;
 264
 265         ap = os_zalloc(sizeof(struct ap_info));
 266         if (ap == NULL)
 267                 return NULL;
 268
 269         /* initialize AP info data */
 270         os_memcpy(ap->addr, addr, ETH_ALEN);
 271         ap_ap_list_add(iface, ap);
 272         iface->num_ap++;
 273         ap_ap_hash_add(iface, ap);
 274         ap_ap_iter_list_add(iface, ap);
 275
 276         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 277                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 278                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 279                 if (iface->conf->passive_scan_interval > 0)
 280                         ap_list_expired_ap(iface, ap->prev);
 281                 ap_free_ap(iface, ap->prev);
 282         }
 283
 284         return ap;
 285 }
 286
 287
 288 void ap_list_process_beacon(struct hostapd_iface *iface,
 289                             struct ieee80211_mgmt *mgmt,
 290                             struct ieee802_11_elems *elems,
 291                             struct hostapd_frame_info *fi)
 292 {
 293         struct ap_info *ap;
 294         int new_ap = 0;
 295         size_t len;
 296         int set_beacon = 0;
 297
 298         if (iface->conf->ap_table_max_size < 1)
 299                 return;
 300
 301         ap = ap_get_ap(iface, mgmt->bssid);
 302         if (!ap) {
 303                 ap = ap_ap_add(iface, mgmt->bssid);
 304                 if (!ap) {
 305                         printf("Failed to allocate AP information entry\n");
 306                         return;
 307                 }
 308                 new_ap = 1;
 309         }
 310
 311         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 312         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 313
 314         if (elems->ssid) {
 315                 len = elems->ssid_len;
 316                 if (len >= sizeof(ap->ssid))
 317                         len = sizeof(ap->ssid) - 1;
 318                 os_memcpy(ap->ssid, elems->ssid, len);
 319                 ap->ssid[len] = '\0';
 320                 ap->ssid_len = len;
 321         }
 322
 323         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 324         len = 0;
 325         if (elems->supp_rates) {
 326                 len = elems->supp_rates_len;
 327                 if (len > WLAN_SUPP_RATES_MAX)
 328                         len = WLAN_SUPP_RATES_MAX;
 329                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 330         }
 331         if (elems->ext_supp_rates) {
 332                 int len2;
 333                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 334                         len2 = WLAN_SUPP_RATES_MAX - len;
 335                 else
 336                         len2 = elems->ext_supp_rates_len;
 337                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 338                           len2);
 339         }
 340
 341         ap->wpa = elems->wpa_ie != NULL;
 342
 343         if (elems->erp_info && elems->erp_info_len == 1)
 344                 ap->erp = elems->erp_info[0];
 345         else
 346                 ap->erp = -1;
 347
 348         if (elems->ds_params && elems->ds_params_len == 1)
 349                 ap->channel = elems->ds_params[0];
 350         else if (fi)
 351                 ap->channel = fi->channel;
 352
 353         if (elems->ht_capabilities)
 354                 ap->ht_support = 1;
 355         else
 356                 ap->ht_support = 0;
 357
 358         ap->num_beacons++;
 359         time(&ap->last_beacon);
 360         if (fi) {
 361                 ap->phytype = fi->phytype;
 362                 ap->ssi_signal = fi->ssi_signal;
 363                 ap->datarate = fi->datarate;
 364         }
 365
 366         if (new_ap) {
 367                 if (iface->conf->passive_scan_interval > 0)
 368                         ap_list_new_ap(iface, ap);
 369         } else if (ap != iface->ap_list) {
 370                 /* move AP entry into the beginning of the list so that the
 371                  * oldest entry is always in the end of the list */
 372                 ap_ap_list_del(iface, ap);
 373                 ap_ap_list_add(iface, ap);
 374         }
 375
 376         if (!iface->olbc &&
 377             ap_list_beacon_olbc(iface, ap)) {
 378                 iface->olbc = 1;
 379                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 380                            "protection", MAC2STR(ap->addr));
 381                 set_beacon++;
 382         }
 383
 384 #ifdef CONFIG_IEEE80211N
 385         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 386                 iface->olbc_ht = 1;
 387                 hostapd_ht_operation_update(iface);
 388                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 389                            " - enable protection", MAC2STR(ap->addr));
 390                 set_beacon++;
 391         }
 392 #endif /* CONFIG_IEEE80211N */
 393
 394         if (set_beacon)
 395                 ieee802_11_set_beacons(iface);
 396 }
 397
 398
 399 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 400 {
 401         struct hostapd_iface *iface = eloop_ctx;
 402         time_t now;
 403         struct ap_info *ap;
 404         int set_beacon = 0;
 405
 406         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 407
 408         if (!iface->ap_list)
 409                 return;
 410
 411         time(&now);
 412
 413         /* FIX: it looks like jkm-Purina ended up in busy loop in this
 414          * function. Apparently, something can still cause a loop in the AP
 415          * list.. */
 416
 417         while (iface->ap_list) {
 418                 ap = iface->ap_list->prev;
 419                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 420                     now)
 421                         break;
 422
 423                 if (iface->conf->passive_scan_interval > 0)
 424                         ap_list_expired_ap(iface, ap);
 425                 ap_free_ap(iface, ap);
 426         }
 427
 428         if (iface->olbc || iface->olbc_ht) {
 429                 int olbc = 0;
 430                 int olbc_ht = 0;
 431
 432                 ap = iface->ap_list;
 433                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 434                         if (ap_list_beacon_olbc(iface, ap))
 435                                 olbc = 1;
 436 #ifdef CONFIG_IEEE80211N
 437                         if (ap_list_beacon_olbc_ht(iface, ap))
 438                                 olbc_ht = 1;
 439 #endif /* CONFIG_IEEE80211N */
 440                         ap = ap->next;
 441                 }
 442                 if (!olbc && iface->olbc) {
 443                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 444                         iface->olbc = 0;
 445                         set_beacon++;
 446                 }
 447 #ifdef CONFIG_IEEE80211N
 448                 if (!olbc_ht && iface->olbc_ht) {
 449                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 450                         iface->olbc_ht = 0;
 451                         hostapd_ht_operation_update(iface);
 452                         set_beacon++;
 453                 }
 454 #endif /* CONFIG_IEEE80211N */
 455         }
 456
 457         if (set_beacon)
 458                 ieee802_11_set_beacons(iface);
 459 }
 460
 461
 462 int ap_list_init(struct hostapd_iface *iface)
 463 {
 464         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 465         return 0;
 466 }
 467
 468
 469 void ap_list_deinit(struct hostapd_iface *iface)
 470 {
 471         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 472         hostapd_free_aps(iface);
 473 }
 474
 475
 476 int ap_list_reconfig(struct hostapd_iface *iface,
 477                      struct hostapd_config *oldconf)
 478 {
 479         time_t now;
 480         struct ap_info *ap;
 481
 482         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 483             iface->conf->ap_table_expiration_time ==
 484             oldconf->ap_table_expiration_time)
 485                 return 0;
 486
 487         time(&now);
 488
 489         while (iface->ap_list) {
 490                 ap = iface->ap_list->prev;
 491                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 492                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 493                     now)
 494                         break;
 495
 496                 if (iface->conf->passive_scan_interval > 0)
 497                         ap_list_expired_ap(iface, iface->ap_list->prev);
 498                 ap_free_ap(iface, iface->ap_list->prev);
 499         }
 500
 501         return 0;
 502 }