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 void ap_list_new_ap(struct hostapd_iface *iface, struct ap_info *ap)
  76 {
  77         wpa_printf(MSG_DEBUG, "New AP detected: " MACSTR, MAC2STR(ap->addr));
  78
  79         /* TODO: could send a notification message to an external program that
  80          * would then determine whether a rogue AP has been detected */
  81 }
  82
  83
  84 static void ap_list_expired_ap(struct hostapd_iface *iface, struct ap_info *ap)
  85 {
  86         wpa_printf(MSG_DEBUG, "AP info expired: " MACSTR, MAC2STR(ap->addr));
  87
  88         /* TODO: could send a notification message to an external program */
  89 }
  90
  91
  92 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
  93 {
  94         int i;
  95
  96         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
  97             ap->phytype != ieee80211_phytype_pbcc_dot11_g ||
  98             iface->conf->channel != ap->channel)
  99                 return 0;
 100
 101         if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
 102                 return 1;
 103
 104         for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
 105                 int rate = (ap->supported_rates[i] & 0x7f) * 5;
 106                 if (rate == 60 || rate == 90 || rate > 110)
 107                         return 0;
 108         }
 109
 110         return 1;
 111 }
 112
 113
 114 #ifdef CONFIG_IEEE80211N
 115 static int ap_list_beacon_olbc_ht(struct hostapd_iface *iface,
 116                                   struct ap_info *ap)
 117 {
 118         return !ap->ht_support;
 119 }
 120 #endif /* CONFIG_IEEE80211N */
 121
 122
 123 struct ap_info * ap_get_ap(struct hostapd_iface *iface, u8 *ap)
 124 {
 125         struct ap_info *s;
 126
 127         s = iface->ap_hash[STA_HASH(ap)];
 128         while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
 129                 s = s->hnext;
 130         return s;
 131 }
 132
 133
 134 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
 135 {
 136         if (iface->ap_list) {
 137                 ap->prev = iface->ap_list->prev;
 138                 iface->ap_list->prev = ap;
 139         } else
 140                 ap->prev = ap;
 141         ap->next = iface->ap_list;
 142         iface->ap_list = ap;
 143 }
 144
 145
 146 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
 147 {
 148         if (iface->ap_list == ap)
 149                 iface->ap_list = ap->next;
 150         else
 151                 ap->prev->next = ap->next;
 152
 153         if (ap->next)
 154                 ap->next->prev = ap->prev;
 155         else if (iface->ap_list)
 156                 iface->ap_list->prev = ap->prev;
 157 }
 158
 159
 160 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
 161                                 struct ap_info *ap)
 162 {
 163         if (iface->ap_iter_list) {
 164                 ap->iter_prev = iface->ap_iter_list->iter_prev;
 165                 iface->ap_iter_list->iter_prev = ap;
 166         } else
 167                 ap->iter_prev = ap;
 168         ap->iter_next = iface->ap_iter_list;
 169         iface->ap_iter_list = ap;
 170 }
 171
 172
 173 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
 174                                 struct ap_info *ap)
 175 {
 176         if (iface->ap_iter_list == ap)
 177                 iface->ap_iter_list = ap->iter_next;
 178         else
 179                 ap->iter_prev->iter_next = ap->iter_next;
 180
 181         if (ap->iter_next)
 182                 ap->iter_next->iter_prev = ap->iter_prev;
 183         else if (iface->ap_iter_list)
 184                 iface->ap_iter_list->iter_prev = ap->iter_prev;
 185 }
 186
 187
 188 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
 189 {
 190         ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
 191         iface->ap_hash[STA_HASH(ap->addr)] = ap;
 192 }
 193
 194
 195 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
 196 {
 197         struct ap_info *s;
 198
 199         s = iface->ap_hash[STA_HASH(ap->addr)];
 200         if (s == NULL) return;
 201         if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
 202                 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
 203                 return;
 204         }
 205
 206         while (s->hnext != NULL &&
 207                os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
 208                 s = s->hnext;
 209         if (s->hnext != NULL)
 210                 s->hnext = s->hnext->hnext;
 211         else
 212                 printf("AP: could not remove AP " MACSTR " from hash table\n",
 213                        MAC2STR(ap->addr));
 214 }
 215
 216
 217 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
 218 {
 219         ap_ap_hash_del(iface, ap);
 220         ap_ap_list_del(iface, ap);
 221         ap_ap_iter_list_del(iface, ap);
 222
 223         iface->num_ap--;
 224         os_free(ap);
 225 }
 226
 227
 228 static void hostapd_free_aps(struct hostapd_iface *iface)
 229 {
 230         struct ap_info *ap, *prev;
 231
 232         ap = iface->ap_list;
 233
 234         while (ap) {
 235                 prev = ap;
 236                 ap = ap->next;
 237                 ap_free_ap(iface, prev);
 238         }
 239
 240         iface->ap_list = NULL;
 241 }
 242
 243
 244 int ap_ap_for_each(struct hostapd_iface *iface,
 245                    int (*func)(struct ap_info *s, void *data), void *data)
 246 {
 247         struct ap_info *s;
 248         int ret = 0;
 249
 250         s = iface->ap_list;
 251
 252         while (s) {
 253                 ret = func(s, data);
 254                 if (ret)
 255                         break;
 256                 s = s->next;
 257         }
 258
 259         return ret;
 260 }
 261
 262
 263 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, u8 *addr)
 264 {
 265         struct ap_info *ap;
 266
 267         ap = os_zalloc(sizeof(struct ap_info));
 268         if (ap == NULL)
 269                 return NULL;
 270
 271         /* initialize AP info data */
 272         os_memcpy(ap->addr, addr, ETH_ALEN);
 273         ap_ap_list_add(iface, ap);
 274         iface->num_ap++;
 275         ap_ap_hash_add(iface, ap);
 276         ap_ap_iter_list_add(iface, ap);
 277
 278         if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
 279                 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
 280                            MACSTR " from AP table", MAC2STR(ap->prev->addr));
 281                 if (iface->conf->passive_scan_interval > 0)
 282                         ap_list_expired_ap(iface, ap->prev);
 283                 ap_free_ap(iface, ap->prev);
 284         }
 285
 286         return ap;
 287 }
 288
 289
 290 void ap_list_process_beacon(struct hostapd_iface *iface,
 291                             struct ieee80211_mgmt *mgmt,
 292                             struct ieee802_11_elems *elems,
 293                             struct hostapd_frame_info *fi)
 294 {
 295         struct ap_info *ap;
 296         int new_ap = 0;
 297         size_t len;
 298         int set_beacon = 0;
 299
 300         if (iface->conf->ap_table_max_size < 1)
 301                 return;
 302
 303         ap = ap_get_ap(iface, mgmt->bssid);
 304         if (!ap) {
 305                 ap = ap_ap_add(iface, mgmt->bssid);
 306                 if (!ap) {
 307                         printf("Failed to allocate AP information entry\n");
 308                         return;
 309                 }
 310                 new_ap = 1;
 311         }
 312
 313         ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
 314         ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
 315
 316         if (elems->ssid) {
 317                 len = elems->ssid_len;
 318                 if (len >= sizeof(ap->ssid))
 319                         len = sizeof(ap->ssid) - 1;
 320                 os_memcpy(ap->ssid, elems->ssid, len);
 321                 ap->ssid[len] = '\0';
 322                 ap->ssid_len = len;
 323         }
 324
 325         os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
 326         len = 0;
 327         if (elems->supp_rates) {
 328                 len = elems->supp_rates_len;
 329                 if (len > WLAN_SUPP_RATES_MAX)
 330                         len = WLAN_SUPP_RATES_MAX;
 331                 os_memcpy(ap->supported_rates, elems->supp_rates, len);
 332         }
 333         if (elems->ext_supp_rates) {
 334                 int len2;
 335                 if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
 336                         len2 = WLAN_SUPP_RATES_MAX - len;
 337                 else
 338                         len2 = elems->ext_supp_rates_len;
 339                 os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
 340                           len2);
 341         }
 342
 343         ap->wpa = elems->wpa_ie != NULL;
 344
 345         if (elems->erp_info && elems->erp_info_len == 1)
 346                 ap->erp = elems->erp_info[0];
 347         else
 348                 ap->erp = -1;
 349
 350         if (elems->ds_params && elems->ds_params_len == 1)
 351                 ap->channel = elems->ds_params[0];
 352         else if (fi)
 353                 ap->channel = fi->channel;
 354
 355         if (elems->ht_capabilities)
 356                 ap->ht_support = 1;
 357         else
 358                 ap->ht_support = 0;
 359
 360         ap->num_beacons++;
 361         time(&ap->last_beacon);
 362         if (fi) {
 363                 ap->phytype = fi->phytype;
 364                 ap->ssi_signal = fi->ssi_signal;
 365                 ap->datarate = fi->datarate;
 366         }
 367
 368         if (new_ap) {
 369                 if (iface->conf->passive_scan_interval > 0)
 370                         ap_list_new_ap(iface, ap);
 371         } else if (ap != iface->ap_list) {
 372                 /* move AP entry into the beginning of the list so that the
 373                  * oldest entry is always in the end of the list */
 374                 ap_ap_list_del(iface, ap);
 375                 ap_ap_list_add(iface, ap);
 376         }
 377
 378         if (!iface->olbc &&
 379             ap_list_beacon_olbc(iface, ap)) {
 380                 iface->olbc = 1;
 381                 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
 382                            "protection", MAC2STR(ap->addr));
 383                 set_beacon++;
 384         }
 385
 386 #ifdef CONFIG_IEEE80211N
 387         if (!iface->olbc_ht && ap_list_beacon_olbc_ht(iface, ap)) {
 388                 iface->olbc_ht = 1;
 389                 hostapd_ht_operation_update(iface);
 390                 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
 391                            " - enable protection", MAC2STR(ap->addr));
 392                 set_beacon++;
 393         }
 394 #endif /* CONFIG_IEEE80211N */
 395
 396         if (set_beacon)
 397                 ieee802_11_set_beacons(iface);
 398 }
 399
 400
 401 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
 402 {
 403         struct hostapd_iface *iface = eloop_ctx;
 404         time_t now;
 405         struct ap_info *ap;
 406         int set_beacon = 0;
 407
 408         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 409
 410         if (!iface->ap_list)
 411                 return;
 412
 413         time(&now);
 414
 415         /* FIX: it looks like jkm-Purina ended up in busy loop in this
 416          * function. Apparently, something can still cause a loop in the AP
 417          * list.. */
 418
 419         while (iface->ap_list) {
 420                 ap = iface->ap_list->prev;
 421                 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
 422                     now)
 423                         break;
 424
 425                 if (iface->conf->passive_scan_interval > 0)
 426                         ap_list_expired_ap(iface, ap);
 427                 ap_free_ap(iface, ap);
 428         }
 429
 430         if (iface->olbc || iface->olbc_ht) {
 431                 int olbc = 0;
 432                 int olbc_ht = 0;
 433
 434                 ap = iface->ap_list;
 435                 while (ap && (olbc == 0 || olbc_ht == 0)) {
 436                         if (ap_list_beacon_olbc(iface, ap))
 437                                 olbc = 1;
 438 #ifdef CONFIG_IEEE80211N
 439                         if (ap_list_beacon_olbc_ht(iface, ap))
 440                                 olbc_ht = 1;
 441 #endif /* CONFIG_IEEE80211N */
 442                         ap = ap->next;
 443                 }
 444                 if (!olbc && iface->olbc) {
 445                         wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
 446                         iface->olbc = 0;
 447                         set_beacon++;
 448                 }
 449 #ifdef CONFIG_IEEE80211N
 450                 if (!olbc_ht && iface->olbc_ht) {
 451                         wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
 452                         iface->olbc_ht = 0;
 453                         hostapd_ht_operation_update(iface);
 454                         set_beacon++;
 455                 }
 456 #endif /* CONFIG_IEEE80211N */
 457         }
 458
 459         if (set_beacon)
 460                 ieee802_11_set_beacons(iface);
 461 }
 462
 463
 464 int ap_list_init(struct hostapd_iface *iface)
 465 {
 466         eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
 467         return 0;
 468 }
 469
 470
 471 void ap_list_deinit(struct hostapd_iface *iface)
 472 {
 473         eloop_cancel_timeout(ap_list_timer, iface, NULL);
 474         hostapd_free_aps(iface);
 475 }
 476
 477
 478 int ap_list_reconfig(struct hostapd_iface *iface,
 479                      struct hostapd_config *oldconf)
 480 {
 481         time_t now;
 482         struct ap_info *ap;
 483
 484         if (iface->conf->ap_table_max_size == oldconf->ap_table_max_size &&
 485             iface->conf->ap_table_expiration_time ==
 486             oldconf->ap_table_expiration_time)
 487                 return 0;
 488
 489         time(&now);
 490
 491         while (iface->ap_list) {
 492                 ap = iface->ap_list->prev;
 493                 if (iface->num_ap <= iface->conf->ap_table_max_size &&
 494                     ap->last_beacon + iface->conf->ap_table_expiration_time >=
 495                     now)
 496                         break;
 497
 498                 if (iface->conf->passive_scan_interval > 0)
 499                         ap_list_expired_ap(iface, iface->ap_list->prev);
 500                 ap_free_ap(iface, iface->ap_list->prev);
 501         }
 502
 503         return 0;
 504 }