wpa_supplicant/bss.c

   1 /*
   2  * BSS table
   3  * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "drivers/driver.h"
  15 #include "wpa_supplicant_i.h"
  16 #include "config.h"
  17 #include "notify.h"
  18 #include "scan.h"
  19 #include "bss.h"
  20
  21
  22 /**
  23  * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
  24  */
  25 #define WPA_BSS_EXPIRATION_PERIOD 10
  26
  27 #define WPA_BSS_FREQ_CHANGED_FLAG       BIT(0)
  28 #define WPA_BSS_SIGNAL_CHANGED_FLAG     BIT(1)
  29 #define WPA_BSS_PRIVACY_CHANGED_FLAG    BIT(2)
  30 #define WPA_BSS_MODE_CHANGED_FLAG       BIT(3)
  31 #define WPA_BSS_WPAIE_CHANGED_FLAG      BIT(4)
  32 #define WPA_BSS_RSNIE_CHANGED_FLAG      BIT(5)
  33 #define WPA_BSS_WPS_CHANGED_FLAG        BIT(6)
  34 #define WPA_BSS_RATES_CHANGED_FLAG      BIT(7)
  35 #define WPA_BSS_IES_CHANGED_FLAG        BIT(8)
  36
  37
  38 static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
  39 {
  40         dl_list_del(&bss->list);
  41         dl_list_del(&bss->list_id);
  42         wpa_s->num_bss--;
  43         wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR
  44                 " SSID '%s'", bss->id, MAC2STR(bss->bssid),
  45                 wpa_ssid_txt(bss->ssid, bss->ssid_len));
  46         wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id);
  47 #ifdef CONFIG_INTERWORKING
  48         wpabuf_free(bss->anqp_venue_name);
  49         wpabuf_free(bss->anqp_network_auth_type);
  50         wpabuf_free(bss->anqp_roaming_consortium);
  51         wpabuf_free(bss->anqp_ip_addr_type_availability);
  52         wpabuf_free(bss->anqp_nai_realm);
  53         wpabuf_free(bss->anqp_3gpp);
  54         wpabuf_free(bss->anqp_domain_name);
  55 #endif /* CONFIG_INTERWORKING */
  56         os_free(bss);
  57 }
  58
  59
  60 struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,
  61                              const u8 *ssid, size_t ssid_len)
  62 {
  63         struct wpa_bss *bss;
  64         if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
  65                 return NULL;
  66         dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
  67                 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
  68                     bss->ssid_len == ssid_len &&
  69                     os_memcmp(bss->ssid, ssid, ssid_len) == 0)
  70                         return bss;
  71         }
  72         return NULL;
  73 }
  74
  75
  76 static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src)
  77 {
  78         os_time_t usec;
  79
  80         dst->flags = src->flags;
  81         os_memcpy(dst->bssid, src->bssid, ETH_ALEN);
  82         dst->freq = src->freq;
  83         dst->beacon_int = src->beacon_int;
  84         dst->caps = src->caps;
  85         dst->qual = src->qual;
  86         dst->noise = src->noise;
  87         dst->level = src->level;
  88         dst->tsf = src->tsf;
  89
  90         os_get_time(&dst->last_update);
  91         dst->last_update.sec -= src->age / 1000;
  92         usec = (src->age % 1000) * 1000;
  93         if (dst->last_update.usec < usec) {
  94                 dst->last_update.sec--;
  95                 dst->last_update.usec += 1000000;
  96         }
  97         dst->last_update.usec -= usec;
  98 }
  99
 100
 101 static int wpa_bss_known(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
 102 {
 103         struct wpa_ssid *ssid;
 104
 105         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 106                 if (ssid->ssid == NULL || ssid->ssid_len == 0)
 107                         continue;
 108                 if (ssid->ssid_len == bss->ssid_len &&
 109                     os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) == 0)
 110                         return 1;
 111         }
 112
 113         return 0;
 114 }
 115
 116
 117 static int wpa_bss_remove_oldest_unknown(struct wpa_supplicant *wpa_s)
 118 {
 119         struct wpa_bss *bss;
 120
 121         dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
 122                 if (!wpa_bss_known(wpa_s, bss)) {
 123                         wpa_bss_remove(wpa_s, bss);
 124                         return 0;
 125                 }
 126         }
 127
 128         return -1;
 129 }
 130
 131
 132 static void wpa_bss_remove_oldest(struct wpa_supplicant *wpa_s)
 133 {
 134         /*
 135          * Remove the oldest entry that does not match with any configured
 136          * network.
 137          */
 138         if (wpa_bss_remove_oldest_unknown(wpa_s) == 0)
 139                 return;
 140
 141         /*
 142          * Remove the oldest entry since no better candidate for removal was
 143          * found.
 144          */
 145         wpa_bss_remove(wpa_s, dl_list_first(&wpa_s->bss,
 146                                             struct wpa_bss, list));
 147 }
 148
 149
 150 static void wpa_bss_add(struct wpa_supplicant *wpa_s,
 151                         const u8 *ssid, size_t ssid_len,
 152                         struct wpa_scan_res *res)
 153 {
 154         struct wpa_bss *bss;
 155
 156         bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len);
 157         if (bss == NULL)
 158                 return;
 159         bss->id = wpa_s->bss_next_id++;
 160         bss->last_update_idx = wpa_s->bss_update_idx;
 161         wpa_bss_copy_res(bss, res);
 162         os_memcpy(bss->ssid, ssid, ssid_len);
 163         bss->ssid_len = ssid_len;
 164         bss->ie_len = res->ie_len;
 165         bss->beacon_ie_len = res->beacon_ie_len;
 166         os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len);
 167
 168         dl_list_add_tail(&wpa_s->bss, &bss->list);
 169         dl_list_add_tail(&wpa_s->bss_id, &bss->list_id);
 170         wpa_s->num_bss++;
 171         wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR
 172                 " SSID '%s'",
 173                 bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len));
 174         wpas_notify_bss_added(wpa_s, bss->bssid, bss->id);
 175         if (wpa_s->num_bss > wpa_s->conf->bss_max_count)
 176                 wpa_bss_remove_oldest(wpa_s);
 177 }
 178
 179
 180 static int are_ies_equal(const struct wpa_bss *old,
 181                          const struct wpa_scan_res *new, u32 ie)
 182 {
 183         const u8 *old_ie, *new_ie;
 184         struct wpabuf *old_ie_buff = NULL;
 185         struct wpabuf *new_ie_buff = NULL;
 186         int new_ie_len, old_ie_len, ret, is_multi;
 187
 188         switch (ie) {
 189         case WPA_IE_VENDOR_TYPE:
 190                 old_ie = wpa_bss_get_vendor_ie(old, ie);
 191                 new_ie = wpa_scan_get_vendor_ie(new, ie);
 192                 is_multi = 0;
 193                 break;
 194         case WPS_IE_VENDOR_TYPE:
 195                 old_ie_buff = wpa_bss_get_vendor_ie_multi(old, ie);
 196                 new_ie_buff = wpa_scan_get_vendor_ie_multi(new, ie);
 197                 is_multi = 1;
 198                 break;
 199         case WLAN_EID_RSN:
 200         case WLAN_EID_SUPP_RATES:
 201         case WLAN_EID_EXT_SUPP_RATES:
 202                 old_ie = wpa_bss_get_ie(old, ie);
 203                 new_ie = wpa_scan_get_ie(new, ie);
 204                 is_multi = 0;
 205                 break;
 206         default:
 207                 wpa_printf(MSG_DEBUG, "bss: %s: cannot compare IEs", __func__);
 208                 return 0;
 209         }
 210
 211         if (is_multi) {
 212                 /* in case of multiple IEs stored in buffer */
 213                 old_ie = old_ie_buff ? wpabuf_head_u8(old_ie_buff) : NULL;
 214                 new_ie = new_ie_buff ? wpabuf_head_u8(new_ie_buff) : NULL;
 215                 old_ie_len = old_ie_buff ? wpabuf_len(old_ie_buff) : 0;
 216                 new_ie_len = new_ie_buff ? wpabuf_len(new_ie_buff) : 0;
 217         } else {
 218                 /* in case of single IE */
 219                 old_ie_len = old_ie ? old_ie[1] + 2 : 0;
 220                 new_ie_len = new_ie ? new_ie[1] + 2 : 0;
 221         }
 222
 223         if (!old_ie || !new_ie)
 224                 ret = !old_ie && !new_ie;
 225         else
 226                 ret = (old_ie_len == new_ie_len &&
 227                        os_memcmp(old_ie, new_ie, old_ie_len) == 0);
 228
 229         wpabuf_free(old_ie_buff);
 230         wpabuf_free(new_ie_buff);
 231
 232         return ret;
 233 }
 234
 235
 236 static u32 wpa_bss_compare_res(const struct wpa_bss *old,
 237                                const struct wpa_scan_res *new)
 238 {
 239         u32 changes = 0;
 240         int caps_diff = old->caps ^ new->caps;
 241
 242         if (old->freq != new->freq)
 243                 changes |= WPA_BSS_FREQ_CHANGED_FLAG;
 244
 245         if (old->level != new->level)
 246                 changes |= WPA_BSS_SIGNAL_CHANGED_FLAG;
 247
 248         if (caps_diff & IEEE80211_CAP_PRIVACY)
 249                 changes |= WPA_BSS_PRIVACY_CHANGED_FLAG;
 250
 251         if (caps_diff & IEEE80211_CAP_IBSS)
 252                 changes |= WPA_BSS_MODE_CHANGED_FLAG;
 253
 254         if (old->ie_len == new->ie_len &&
 255             os_memcmp(old + 1, new + 1, old->ie_len) == 0)
 256                 return changes;
 257         changes |= WPA_BSS_IES_CHANGED_FLAG;
 258
 259         if (!are_ies_equal(old, new, WPA_IE_VENDOR_TYPE))
 260                 changes |= WPA_BSS_WPAIE_CHANGED_FLAG;
 261
 262         if (!are_ies_equal(old, new, WLAN_EID_RSN))
 263                 changes |= WPA_BSS_RSNIE_CHANGED_FLAG;
 264
 265         if (!are_ies_equal(old, new, WPS_IE_VENDOR_TYPE))
 266                 changes |= WPA_BSS_WPS_CHANGED_FLAG;
 267
 268         if (!are_ies_equal(old, new, WLAN_EID_SUPP_RATES) ||
 269             !are_ies_equal(old, new, WLAN_EID_EXT_SUPP_RATES))
 270                 changes |= WPA_BSS_RATES_CHANGED_FLAG;
 271
 272         return changes;
 273 }
 274
 275
 276 static void notify_bss_changes(struct wpa_supplicant *wpa_s, u32 changes,
 277                                const struct wpa_bss *bss)
 278 {
 279         if (changes & WPA_BSS_FREQ_CHANGED_FLAG)
 280                 wpas_notify_bss_freq_changed(wpa_s, bss->id);
 281
 282         if (changes & WPA_BSS_SIGNAL_CHANGED_FLAG)
 283                 wpas_notify_bss_signal_changed(wpa_s, bss->id);
 284
 285         if (changes & WPA_BSS_PRIVACY_CHANGED_FLAG)
 286                 wpas_notify_bss_privacy_changed(wpa_s, bss->id);
 287
 288         if (changes & WPA_BSS_MODE_CHANGED_FLAG)
 289                 wpas_notify_bss_mode_changed(wpa_s, bss->id);
 290
 291         if (changes & WPA_BSS_WPAIE_CHANGED_FLAG)
 292                 wpas_notify_bss_wpaie_changed(wpa_s, bss->id);
 293
 294         if (changes & WPA_BSS_RSNIE_CHANGED_FLAG)
 295                 wpas_notify_bss_rsnie_changed(wpa_s, bss->id);
 296
 297         if (changes & WPA_BSS_WPS_CHANGED_FLAG)
 298                 wpas_notify_bss_wps_changed(wpa_s, bss->id);
 299
 300         if (changes & WPA_BSS_IES_CHANGED_FLAG)
 301                 wpas_notify_bss_ies_changed(wpa_s, bss->id);
 302
 303         if (changes & WPA_BSS_RATES_CHANGED_FLAG)
 304                 wpas_notify_bss_rates_changed(wpa_s, bss->id);
 305 }
 306
 307
 308 static void wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 309                            struct wpa_scan_res *res)
 310 {
 311         u32 changes;
 312
 313         changes = wpa_bss_compare_res(bss, res);
 314         bss->scan_miss_count = 0;
 315         bss->last_update_idx = wpa_s->bss_update_idx;
 316         wpa_bss_copy_res(bss, res);
 317         /* Move the entry to the end of the list */
 318         dl_list_del(&bss->list);
 319         if (bss->ie_len + bss->beacon_ie_len >=
 320             res->ie_len + res->beacon_ie_len) {
 321                 os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len);
 322                 bss->ie_len = res->ie_len;
 323                 bss->beacon_ie_len = res->beacon_ie_len;
 324         } else {
 325                 struct wpa_bss *nbss;
 326                 struct dl_list *prev = bss->list_id.prev;
 327                 dl_list_del(&bss->list_id);
 328                 nbss = os_realloc(bss, sizeof(*bss) + res->ie_len +
 329                                   res->beacon_ie_len);
 330                 if (nbss) {
 331                         if (wpa_s->current_bss == bss)
 332                                 wpa_s->current_bss = nbss;
 333                         bss = nbss;
 334                         os_memcpy(bss + 1, res + 1,
 335                                   res->ie_len + res->beacon_ie_len);
 336                         bss->ie_len = res->ie_len;
 337                         bss->beacon_ie_len = res->beacon_ie_len;
 338                 }
 339                 dl_list_add(prev, &bss->list_id);
 340         }
 341         dl_list_add_tail(&wpa_s->bss, &bss->list);
 342
 343         notify_bss_changes(wpa_s, changes, bss);
 344 }
 345
 346
 347 static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
 348 {
 349         return bss == wpa_s->current_bss ||
 350                 os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
 351                 os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0;
 352 }
 353
 354
 355 void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
 356 {
 357         wpa_s->bss_update_idx++;
 358         wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Start scan result update %u",
 359                 wpa_s->bss_update_idx);
 360 }
 361
 362
 363 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
 364                              struct wpa_scan_res *res)
 365 {
 366         const u8 *ssid, *p2p;
 367         struct wpa_bss *bss;
 368
 369         ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
 370         if (ssid == NULL) {
 371                 wpa_dbg(wpa_s, MSG_DEBUG, "BSS: No SSID IE included for "
 372                         MACSTR, MAC2STR(res->bssid));
 373                 return;
 374         }
 375         if (ssid[1] > 32) {
 376                 wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Too long SSID IE included for "
 377                         MACSTR, MAC2STR(res->bssid));
 378                 return;
 379         }
 380
 381         p2p = wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE);
 382 #ifdef CONFIG_P2P
 383         if (p2p == NULL &&
 384             wpa_s->p2p_group_interface != NOT_P2P_GROUP_INTERFACE) {
 385                 /*
 386                  * If it's a P2P specific interface, then don't update
 387                  * the scan result without a P2P IE.
 388                  */
 389                 wpa_printf(MSG_DEBUG, "BSS: No P2P IE - skipping BSS " MACSTR
 390                            " update for P2P interface", MAC2STR(res->bssid));
 391                 return;
 392         }
 393 #endif /* CONFIG_P2P */
 394         if (p2p && ssid[1] == P2P_WILDCARD_SSID_LEN &&
 395             os_memcmp(ssid + 2, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) == 0)
 396                 return; /* Skip P2P listen discovery results here */
 397
 398         /* TODO: add option for ignoring BSSes we are not interested in
 399          * (to save memory) */
 400         bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
 401         if (bss == NULL)
 402                 wpa_bss_add(wpa_s, ssid + 2, ssid[1], res);
 403         else
 404                 wpa_bss_update(wpa_s, bss, res);
 405 }
 406
 407
 408 static int wpa_bss_included_in_scan(const struct wpa_bss *bss,
 409                                     const struct scan_info *info)
 410 {
 411         int found;
 412         size_t i;
 413
 414         if (info == NULL)
 415                 return 1;
 416
 417         if (info->num_freqs) {
 418                 found = 0;
 419                 for (i = 0; i < info->num_freqs; i++) {
 420                         if (bss->freq == info->freqs[i]) {
 421                                 found = 1;
 422                                 break;
 423                         }
 424                 }
 425                 if (!found)
 426                         return 0;
 427         }
 428
 429         if (info->num_ssids) {
 430                 found = 0;
 431                 for (i = 0; i < info->num_ssids; i++) {
 432                         const struct wpa_driver_scan_ssid *s = &info->ssids[i];
 433                         if ((s->ssid == NULL || s->ssid_len == 0) ||
 434                             (s->ssid_len == bss->ssid_len &&
 435                              os_memcmp(s->ssid, bss->ssid, bss->ssid_len) ==
 436                              0)) {
 437                                 found = 1;
 438                                 break;
 439                         }
 440                 }
 441                 if (!found)
 442                         return 0;
 443         }
 444
 445         return 1;
 446 }
 447
 448
 449 void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
 450                         int new_scan)
 451 {
 452         struct wpa_bss *bss, *n;
 453
 454         if (!new_scan)
 455                 return; /* do not expire entries without new scan */
 456
 457         dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
 458                 if (wpa_bss_in_use(wpa_s, bss))
 459                         continue;
 460                 if (!wpa_bss_included_in_scan(bss, info))
 461                         continue; /* expire only BSSes that were scanned */
 462                 if (bss->last_update_idx < wpa_s->bss_update_idx)
 463                         bss->scan_miss_count++;
 464                 if (bss->scan_miss_count >=
 465                     wpa_s->conf->bss_expiration_scan_count) {
 466                         wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Expire BSS %u due to "
 467                                 "no match in scan", bss->id);
 468                         wpa_bss_remove(wpa_s, bss);
 469                 }
 470         }
 471 }
 472
 473
 474 void wpa_bss_flush_by_age(struct wpa_supplicant *wpa_s, int age)
 475 {
 476         struct wpa_bss *bss, *n;
 477         struct os_time t;
 478
 479         if (dl_list_empty(&wpa_s->bss))
 480                 return;
 481
 482         os_get_time(&t);
 483         t.sec -= age;
 484
 485         dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
 486                 if (wpa_bss_in_use(wpa_s, bss))
 487                         continue;
 488
 489                 if (os_time_before(&bss->last_update, &t)) {
 490                         wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Expire BSS %u due to "
 491                                 "age", bss->id);
 492                         wpa_bss_remove(wpa_s, bss);
 493                 } else
 494                         break;
 495         }
 496 }
 497
 498
 499 static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx)
 500 {
 501         struct wpa_supplicant *wpa_s = eloop_ctx;
 502
 503         wpa_bss_flush_by_age(wpa_s, wpa_s->conf->bss_expiration_age);
 504         eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
 505                                wpa_bss_timeout, wpa_s, NULL);
 506 }
 507
 508
 509 int wpa_bss_init(struct wpa_supplicant *wpa_s)
 510 {
 511         dl_list_init(&wpa_s->bss);
 512         dl_list_init(&wpa_s->bss_id);
 513         eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
 514                                wpa_bss_timeout, wpa_s, NULL);
 515         return 0;
 516 }
 517
 518
 519 void wpa_bss_flush(struct wpa_supplicant *wpa_s)
 520 {
 521         struct wpa_bss *bss, *n;
 522
 523         if (wpa_s->bss.next == NULL)
 524                 return; /* BSS table not yet initialized */
 525
 526         dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
 527                 if (wpa_bss_in_use(wpa_s, bss))
 528                         continue;
 529                 wpa_bss_remove(wpa_s, bss);
 530         }
 531 }
 532
 533
 534 void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
 535 {
 536         eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL);
 537         wpa_bss_flush(wpa_s);
 538 }
 539
 540
 541 struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
 542                                    const u8 *bssid)
 543 {
 544         struct wpa_bss *bss;
 545         if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
 546                 return NULL;
 547         dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
 548                 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
 549                         return bss;
 550         }
 551         return NULL;
 552 }
 553
 554
 555 #ifdef CONFIG_P2P
 556 struct wpa_bss * wpa_bss_get_p2p_dev_addr(struct wpa_supplicant *wpa_s,
 557                                           const u8 *dev_addr)
 558 {
 559         struct wpa_bss *bss;
 560         dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
 561                 u8 addr[ETH_ALEN];
 562                 if (p2p_parse_dev_addr((const u8 *) (bss + 1), bss->ie_len,
 563                                        addr) == 0 &&
 564                     os_memcmp(addr, dev_addr, ETH_ALEN) == 0)
 565                         return bss;
 566         }
 567         return NULL;
 568 }
 569 #endif /* CONFIG_P2P */
 570
 571
 572 struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
 573 {
 574         struct wpa_bss *bss;
 575         dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
 576                 if (bss->id == id)
 577                         return bss;
 578         }
 579         return NULL;
 580 }
 581
 582
 583 const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
 584 {
 585         const u8 *end, *pos;
 586
 587         pos = (const u8 *) (bss + 1);
 588         end = pos + bss->ie_len;
 589
 590         while (pos + 1 < end) {
 591                 if (pos + 2 + pos[1] > end)
 592                         break;
 593                 if (pos[0] == ie)
 594                         return pos;
 595                 pos += 2 + pos[1];
 596         }
 597
 598         return NULL;
 599 }
 600
 601
 602 const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type)
 603 {
 604         const u8 *end, *pos;
 605
 606         pos = (const u8 *) (bss + 1);
 607         end = pos + bss->ie_len;
 608
 609         while (pos + 1 < end) {
 610                 if (pos + 2 + pos[1] > end)
 611                         break;
 612                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 613                     vendor_type == WPA_GET_BE32(&pos[2]))
 614                         return pos;
 615                 pos += 2 + pos[1];
 616         }
 617
 618         return NULL;
 619 }
 620
 621
 622 struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss,
 623                                             u32 vendor_type)
 624 {
 625         struct wpabuf *buf;
 626         const u8 *end, *pos;
 627
 628         buf = wpabuf_alloc(bss->ie_len);
 629         if (buf == NULL)
 630                 return NULL;
 631
 632         pos = (const u8 *) (bss + 1);
 633         end = pos + bss->ie_len;
 634
 635         while (pos + 1 < end) {
 636                 if (pos + 2 + pos[1] > end)
 637                         break;
 638                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 639                     vendor_type == WPA_GET_BE32(&pos[2]))
 640                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 641                 pos += 2 + pos[1];
 642         }
 643
 644         if (wpabuf_len(buf) == 0) {
 645                 wpabuf_free(buf);
 646                 buf = NULL;
 647         }
 648
 649         return buf;
 650 }
 651
 652
 653 int wpa_bss_get_max_rate(const struct wpa_bss *bss)
 654 {
 655         int rate = 0;
 656         const u8 *ie;
 657         int i;
 658
 659         ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
 660         for (i = 0; ie && i < ie[1]; i++) {
 661                 if ((ie[i + 2] & 0x7f) > rate)
 662                         rate = ie[i + 2] & 0x7f;
 663         }
 664
 665         ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
 666         for (i = 0; ie && i < ie[1]; i++) {
 667                 if ((ie[i + 2] & 0x7f) > rate)
 668                         rate = ie[i + 2] & 0x7f;
 669         }
 670
 671         return rate;
 672 }
 673
 674
 675 int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates)
 676 {
 677         const u8 *ie, *ie2;
 678         int i, j;
 679         unsigned int len;
 680         u8 *r;
 681
 682         ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
 683         ie2 = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
 684
 685         len = (ie ? ie[1] : 0) + (ie2 ? ie2[1] : 0);
 686
 687         r = os_malloc(len);
 688         if (!r)
 689                 return -1;
 690
 691         for (i = 0; ie && i < ie[1]; i++)
 692                 r[i] = ie[i + 2] & 0x7f;
 693
 694         for (j = 0; ie2 && j < ie2[1]; j++)
 695                 r[i + j] = ie2[j + 2] & 0x7f;
 696
 697         *rates = r;
 698         return len;
 699 }