wpa_supplicant/bss.c

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