wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, 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 "config.h"
  21 #include "wpa_supplicant_i.h"
  22 #include "driver_i.h"
  23 #include "mlme.h"
  24 #include "wps_supplicant.h"
  25 #include "notify.h"
  26 #include "bss.h"
  27 #include "scan.h"
  28
  29
  30 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  31 {
  32         struct wpa_ssid *ssid;
  33         union wpa_event_data data;
  34
  35         ssid = wpa_supplicant_get_ssid(wpa_s);
  36         if (ssid == NULL)
  37                 return;
  38
  39         if (wpa_s->current_ssid == NULL) {
  40                 wpa_s->current_ssid = ssid;
  41                 if (wpa_s->current_ssid != NULL)
  42                         wpas_notify_network_changed(wpa_s);
  43         }
  44         wpa_supplicant_initiate_eapol(wpa_s);
  45         wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
  46                    "generating associated event");
  47         os_memset(&data, 0, sizeof(data));
  48         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  49 }
  50
  51
  52 #ifdef CONFIG_WPS
  53 static int wpas_wps_in_use(struct wpa_config *conf,
  54                            enum wps_request_type *req_type)
  55 {
  56         struct wpa_ssid *ssid;
  57         int wps = 0;
  58
  59         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
  60                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  61                         continue;
  62
  63                 wps = 1;
  64                 *req_type = wpas_wps_get_req_type(ssid);
  65                 if (!ssid->eap.phase1)
  66                         continue;
  67
  68                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  69                         return 2;
  70         }
  71
  72         return wps;
  73 }
  74 #endif /* CONFIG_WPS */
  75
  76
  77 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  78 {
  79         struct wpa_ssid *ssid = conf->ssid;
  80         while (ssid) {
  81                 if (!ssid->disabled)
  82                         return 1;
  83                 ssid = ssid->next;
  84         }
  85         return 0;
  86 }
  87
  88
  89 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
  90                                      struct wpa_ssid *ssid)
  91 {
  92         while (ssid) {
  93                 if (!ssid->disabled)
  94                         break;
  95                 ssid = ssid->next;
  96         }
  97
  98         /* ap_scan=2 mode - try to associate with each SSID. */
  99         if (ssid == NULL) {
 100                 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
 101                            "end of scan list - go back to beginning");
 102                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 103                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 104                 return;
 105         }
 106         if (ssid->next) {
 107                 /* Continue from the next SSID on the next attempt. */
 108                 wpa_s->prev_scan_ssid = ssid;
 109         } else {
 110                 /* Start from the beginning of the SSID list. */
 111                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 112         }
 113         wpa_supplicant_associate(wpa_s, NULL, ssid);
 114 }
 115
 116
 117 static int int_array_len(const int *a)
 118 {
 119         int i;
 120         for (i = 0; a && a[i]; i++)
 121                 ;
 122         return i;
 123 }
 124
 125
 126 static void int_array_concat(int **res, const int *a)
 127 {
 128         int reslen, alen, i;
 129         int *n;
 130
 131         reslen = int_array_len(*res);
 132         alen = int_array_len(a);
 133
 134         n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 135         if (n == NULL) {
 136                 os_free(*res);
 137                 *res = NULL;
 138                 return;
 139         }
 140         for (i = 0; i <= alen; i++)
 141                 n[reslen + i] = a[i];
 142         *res = n;
 143 }
 144
 145
 146 static int freq_cmp(const void *a, const void *b)
 147 {
 148         int _a = *(int *) a;
 149         int _b = *(int *) b;
 150
 151         if (_a == 0)
 152                 return 1;
 153         if (_b == 0)
 154                 return -1;
 155         return _a - _b;
 156 }
 157
 158
 159 static void int_array_sort_unique(int *a)
 160 {
 161         int alen;
 162         int i, j;
 163
 164         if (a == NULL)
 165                 return;
 166
 167         alen = int_array_len(a);
 168         qsort(a, alen, sizeof(int), freq_cmp);
 169
 170         i = 0;
 171         j = 1;
 172         while (a[i] && a[j]) {
 173                 if (a[i] == a[j]) {
 174                         j++;
 175                         continue;
 176                 }
 177                 a[++i] = a[j++];
 178         }
 179         if (a[i])
 180                 i++;
 181         a[i] = 0;
 182 }
 183
 184
 185 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 186                                 struct wpa_driver_scan_params *params)
 187 {
 188         int ret;
 189
 190         wpa_supplicant_notify_scanning(wpa_s, 1);
 191
 192         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 193                 ret = ieee80211_sta_req_scan(wpa_s, params);
 194         else
 195                 ret = wpa_drv_scan(wpa_s, params);
 196
 197         if (ret) {
 198                 wpa_supplicant_notify_scanning(wpa_s, 0);
 199                 wpas_notify_scan_done(wpa_s, 0);
 200         } else
 201                 wpa_s->scan_runs++;
 202
 203         return ret;
 204 }
 205
 206
 207 static struct wpa_driver_scan_filter *
 208 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 209 {
 210         struct wpa_driver_scan_filter *ssids;
 211         struct wpa_ssid *ssid;
 212         size_t count;
 213
 214         *num_ssids = 0;
 215         if (!conf->filter_ssids)
 216                 return NULL;
 217
 218         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 219                 if (ssid->ssid && ssid->ssid_len)
 220                         count++;
 221         }
 222         if (count == 0)
 223                 return NULL;
 224         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 225         if (ssids == NULL)
 226                 return NULL;
 227
 228         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 229                 if (!ssid->ssid || !ssid->ssid_len)
 230                         continue;
 231                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 232                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 233                 (*num_ssids)++;
 234         }
 235
 236         return ssids;
 237 }
 238
 239
 240 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 241 {
 242         struct wpa_supplicant *wpa_s = eloop_ctx;
 243         struct wpa_ssid *ssid;
 244         int scan_req = 0, ret;
 245         struct wpabuf *wps_ie = NULL;
 246 #ifdef CONFIG_WPS
 247         int wps = 0;
 248         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 249 #endif /* CONFIG_WPS */
 250         struct wpa_driver_scan_params params;
 251         size_t max_ssids;
 252         enum wpa_states prev_state;
 253
 254         if (wpa_s->disconnected && !wpa_s->scan_req) {
 255                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 256         /*
 257          * Oct, 26th. 2011. TIZEN
 258          * If scan after auth timeout is failed, wpa_s->associate_num should be initialized.
 259          */
 260                 wpa_s->associate_num = 2;
 261                 return;
 262         }
 263
 264         wpa_printf(MSG_DEBUG,"Current scan req is [%d]",wpa_s->scan_req);
 265         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 266             !wpa_s->scan_req) {
 267                 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
 268                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 269                 /*
 270                  * Oct, 26th. 2011. TIZEN
 271                  * If scan after auth timeout is failed, wpa_s->associate_num should be initialized.
 272                  */
 273                 wpa_s->associate_num = 2;
 274                 return;
 275         }
 276
 277         if (wpa_s->conf->ap_scan != 0 &&
 278             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 279                 wpa_printf(MSG_DEBUG, "Using wired authentication - "
 280                            "overriding ap_scan configuration");
 281                 wpa_s->conf->ap_scan = 0;
 282                 wpas_notify_ap_scan_changed(wpa_s);
 283         }
 284
 285         if (wpa_s->conf->ap_scan == 0) {
 286                 wpa_supplicant_gen_assoc_event(wpa_s);
 287                 return;
 288         }
 289
 290         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 291             wpa_s->conf->ap_scan == 2)
 292                 max_ssids = 1;
 293         else {
 294                 max_ssids = wpa_s->max_scan_ssids;
 295                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 296                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 297         }
 298
 299 #ifdef CONFIG_WPS
 300         wps = wpas_wps_in_use(wpa_s->conf, &req_type);
 301 #endif /* CONFIG_WPS */
 302
 303         scan_req = wpa_s->scan_req;
 304         wpa_s->scan_req = 0;
 305
 306         os_memset(&params, 0, sizeof(params));
 307
 308         prev_state = wpa_s->wpa_state;
 309         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 310             wpa_s->wpa_state == WPA_INACTIVE)
 311                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 312
 313         /* Find the starting point from which to continue scanning */
 314         ssid = wpa_s->conf->ssid;
 315         if(ssid != NULL)
 316         {
 317                 wpa_printf(MSG_DEBUG, "==============================");
 318                 wpa_printf(MSG_DEBUG, "Check 1 wildcard ssid [%s]",ssid->ssid);
 319                 wpa_printf(MSG_DEBUG, "==============================");
 320         }
 321         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 322                 while (ssid) {
 323                         if (ssid == wpa_s->prev_scan_ssid) {
 324                                 ssid = ssid->next;
 325                                 break;
 326                         }
 327                         ssid = ssid->next;
 328                         if(ssid != NULL)
 329                         {
 330                                 wpa_printf(MSG_DEBUG, "==============================");
 331                                 wpa_printf(MSG_DEBUG, "Check 2 wildcard ssid [%s]",ssid->ssid);
 332                                 wpa_printf(MSG_DEBUG, "==============================");
 333                         }
 334                 }
 335         }
 336
 337         if (scan_req != 2 && (wpa_s->conf->ap_scan == 2 ||
 338                               wpa_s->connect_without_scan)) {
 339                 wpa_s->connect_without_scan = 0;
 340                 wpa_supplicant_assoc_try(wpa_s, ssid);
 341                 return;
 342         } else if (wpa_s->conf->ap_scan == 2) {
 343                 /*
 344                  * User-initiated scan request in ap_scan == 2; scan with
 345                  * wildcard SSID.
 346                  */
 347                 ssid = NULL;
 348                 wpa_printf(MSG_DEBUG, "==============================");
 349                 wpa_printf(MSG_DEBUG, "Check 3 wildcard ssid is NULL");
 350                 wpa_printf(MSG_DEBUG, "==============================");
 351         } else {
 352                 struct wpa_ssid *start = ssid, *tssid;
 353                 int freqs_set = 0;
 354                 if (ssid == NULL && max_ssids > 1)
 355                 {
 356                         ssid = wpa_s->conf->ssid;
 357                         if(ssid != NULL)
 358                         {
 359                         wpa_printf(MSG_DEBUG, "==============================");
 360                         wpa_printf(MSG_DEBUG, "Check 4 wildcard ssid [%s]",ssid->ssid);
 361                         wpa_printf(MSG_DEBUG, "==============================");
 362                         }
 363                 }
 364                 while (ssid) {
 365                         if (!ssid->disabled && ssid->scan_ssid) {
 366                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 367                                                   ssid->ssid, ssid->ssid_len);
 368                                 params.ssids[params.num_ssids].ssid =
 369                                         ssid->ssid;
 370                                 params.ssids[params.num_ssids].ssid_len =
 371                                         ssid->ssid_len;
 372                                 params.num_ssids++;
 373                                 if (params.num_ssids + 1 >= max_ssids)
 374                                         break;
 375                         }
 376                         ssid = ssid->next;
 377                         if (ssid == start)
 378                                 break;
 379                         if (ssid == NULL && max_ssids > 1 &&
 380                             start != wpa_s->conf->ssid)
 381                                 ssid = wpa_s->conf->ssid;
 382                 }
 383                 if(ssid != NULL)
 384                 {
 385                         wpa_printf(MSG_DEBUG, "==============================");
 386                         wpa_printf(MSG_DEBUG, "Check 5 wildcard ssid [%s]",ssid->ssid);
 387                         wpa_printf(MSG_DEBUG, "==============================");
 388                 }
 389                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 390                         if (tssid->disabled)
 391                                 continue;
 392                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 393                                 int_array_concat(&params.freqs,
 394                                                  tssid->scan_freq);
 395                         } else {
 396                                 os_free(params.freqs);
 397                                 params.freqs = NULL;
 398                         }
 399                         freqs_set = 1;
 400                 }
 401                 int_array_sort_unique(params.freqs);
 402         }
 403         if(ssid != NULL)
 404         {
 405                 wpa_printf(MSG_DEBUG, "==============================");
 406                 wpa_printf(MSG_DEBUG, "Check 6 wildcard ssid [%s]",ssid->ssid);
 407                 wpa_printf(MSG_DEBUG, "==============================");
 408         }
 409         if (ssid) {
 410                 wpa_s->prev_scan_ssid = ssid;
 411                 if (max_ssids > 1) {
 412                         wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
 413                                    "scan request");
 414                         params.num_ssids++;
 415                 }
 416                 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
 417         } else {
 418                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 419                 params.num_ssids++;
 420                 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
 421         }
 422
 423 #ifdef CONFIG_WPS
 424         if (params.freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 425                 /*
 426                  * Optimize post-provisioning scan based on channel used
 427                  * during provisioning.
 428                  */
 429                 wpa_printf(MSG_DEBUG, "WPS: Scan only frequency %u MHz that "
 430                            "was used during provisioning", wpa_s->wps_freq);
 431                 params.freqs = os_zalloc(2 * sizeof(int));
 432                 if (params.freqs)
 433                         params.freqs[0] = wpa_s->wps_freq;
 434                 wpa_s->after_wps--;
 435         }
 436
 437         if (wps) {
 438                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 439                                                 wpa_s->wps->uuid, req_type);
 440                 if (wps_ie) {
 441                         params.extra_ies = wpabuf_head(wps_ie);
 442                         params.extra_ies_len = wpabuf_len(wps_ie);
 443                 }
 444         }
 445 #endif /* CONFIG_WPS */
 446
 447         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 448                 wpa_s->conf, &params.num_filter_ssids);
 449
 450         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 451
 452         wpabuf_free(wps_ie);
 453         os_free(params.freqs);
 454         os_free(params.filter_ssids);
 455
 456         if (ret) {
 457                 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
 458                 if (prev_state != wpa_s->wpa_state)
 459                         wpa_supplicant_set_state(wpa_s, prev_state);
 460                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 461         }
 462 }
 463
 464
 465 /**
 466  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 467  * @wpa_s: Pointer to wpa_supplicant data
 468  * @sec: Number of seconds after which to scan
 469  * @usec: Number of microseconds after which to scan
 470  *
 471  * This function is used to schedule a scan for neighboring access points after
 472  * the specified time.
 473  */
 474 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 475 {
 476         /* If there's at least one network that should be specifically scanned
 477          * then don't cancel the scan and reschedule.  Some drivers do
 478          * background scanning which generates frequent scan results, and that
 479          * causes the specific SSID scan to get continually pushed back and
 480          * never happen, which causes hidden APs to never get probe-scanned.
 481          */
 482         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 483             wpa_s->conf->ap_scan == 1) {
 484                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 485
 486                 while (ssid) {
 487                         if (!ssid->disabled && ssid->scan_ssid)
 488                                 break;
 489                         ssid = ssid->next;
 490                 }
 491                 if (ssid) {
 492                         wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 493                                 "ensure that specific SSID scans occur");
 494                         return;
 495                 }
 496         }
 497
 498         wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 499                 sec, usec);
 500         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 501         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 502 }
 503
 504
 505 /**
 506  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 507  * @wpa_s: Pointer to wpa_supplicant data
 508  *
 509  * This function is used to cancel a scan request scheduled with
 510  * wpa_supplicant_req_scan().
 511  */
 512 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 513 {
 514         wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 515         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 516 }
 517
 518
 519 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 520                                     int scanning)
 521 {
 522         if (wpa_s->scanning != scanning) {
 523                 wpa_s->scanning = scanning;
 524                 wpas_notify_scanning(wpa_s);
 525         }
 526 }
 527
 528
 529 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 530 {
 531         int rate = 0;
 532         const u8 *ie;
 533         int i;
 534
 535         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 536         for (i = 0; ie && i < ie[1]; i++) {
 537                 if ((ie[i + 2] & 0x7f) > rate)
 538                         rate = ie[i + 2] & 0x7f;
 539         }
 540
 541         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 542         for (i = 0; ie && i < ie[1]; i++) {
 543                 if ((ie[i + 2] & 0x7f) > rate)
 544                         rate = ie[i + 2] & 0x7f;
 545         }
 546
 547         return rate;
 548 }
 549
 550
 551 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 552 {
 553         const u8 *end, *pos;
 554
 555         pos = (const u8 *) (res + 1);
 556         end = pos + res->ie_len;
 557
 558         while (pos + 1 < end) {
 559                 if (pos + 2 + pos[1] > end)
 560                         break;
 561                 if (pos[0] == ie)
 562                         return pos;
 563                 pos += 2 + pos[1];
 564         }
 565
 566         return NULL;
 567 }
 568
 569
 570 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 571                                   u32 vendor_type)
 572 {
 573         const u8 *end, *pos;
 574
 575         pos = (const u8 *) (res + 1);
 576         end = pos + res->ie_len;
 577
 578         while (pos + 1 < end) {
 579                 if (pos + 2 + pos[1] > end)
 580                         break;
 581                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 582                     vendor_type == WPA_GET_BE32(&pos[2]))
 583                         return pos;
 584                 pos += 2 + pos[1];
 585         }
 586
 587         return NULL;
 588 }
 589
 590
 591 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 592                                              u32 vendor_type)
 593 {
 594         struct wpabuf *buf;
 595         const u8 *end, *pos;
 596
 597         buf = wpabuf_alloc(res->ie_len);
 598         if (buf == NULL)
 599                 return NULL;
 600
 601         pos = (const u8 *) (res + 1);
 602         end = pos + res->ie_len;
 603
 604         while (pos + 1 < end) {
 605                 if (pos + 2 + pos[1] > end)
 606                         break;
 607                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 608                     vendor_type == WPA_GET_BE32(&pos[2]))
 609                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 610                 pos += 2 + pos[1];
 611         }
 612
 613         if (wpabuf_len(buf) == 0) {
 614                 wpabuf_free(buf);
 615                 buf = NULL;
 616         }
 617
 618         return buf;
 619 }
 620
 621
 622 /* Compare function for sorting scan results. Return >0 if @b is considered
 623  * better. */
 624 static int wpa_scan_result_compar(const void *a, const void *b)
 625 {
 626         struct wpa_scan_res **_wa = (void *) a;
 627         struct wpa_scan_res **_wb = (void *) b;
 628         struct wpa_scan_res *wa = *_wa;
 629         struct wpa_scan_res *wb = *_wb;
 630         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 631
 632         /* WPA/WPA2 support preferred */
 633         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 634                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 635         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 636                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
 637
 638         if (wpa_b && !wpa_a)
 639                 return 1;
 640         if (!wpa_b && wpa_a)
 641                 return -1;
 642
 643         /* privacy support preferred */
 644         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
 645             (wb->caps & IEEE80211_CAP_PRIVACY))
 646                 return 1;
 647         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
 648             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
 649                 return -1;
 650
 651         /* best/max rate preferred if signal level close enough XXX */
 652         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
 653             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
 654                 maxrate_a = wpa_scan_get_max_rate(wa);
 655                 maxrate_b = wpa_scan_get_max_rate(wb);
 656                 if (maxrate_a != maxrate_b)
 657                         return maxrate_b - maxrate_a;
 658         }
 659
 660         /* use freq for channel preference */
 661
 662         /* all things being equal, use signal level; if signal levels are
 663          * identical, use quality values since some drivers may only report
 664          * that value and leave the signal level zero */
 665         if (wb->level == wa->level)
 666                 return wb->qual - wa->qual;
 667         return wb->level - wa->level;
 668 }
 669
 670
 671 /**
 672  * wpa_supplicant_get_scan_results - Get scan results
 673  * @wpa_s: Pointer to wpa_supplicant data
 674  * @info: Information about what was scanned or %NULL if not available
 675  * @new_scan: Whether a new scan was performed
 676  * Returns: Scan results, %NULL on failure
 677  *
 678  * This function request the current scan results from the driver and updates
 679  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
 680  * results with wpa_scan_results_free().
 681  */
 682 struct wpa_scan_results *
 683 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
 684                                 struct scan_info *info, int new_scan)
 685 {
 686         struct wpa_scan_results *scan_res;
 687         size_t i;
 688
 689         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 690                 scan_res = ieee80211_sta_get_scan_results(wpa_s);
 691         else
 692                 scan_res = wpa_drv_get_scan_results2(wpa_s);
 693         if (scan_res == NULL) {
 694                 wpa_printf(MSG_DEBUG, "Failed to get scan results");
 695                 return NULL;
 696         }
 697
 698         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
 699               wpa_scan_result_compar);
 700         wpa_printf(MSG_DEBUG,"current scan num is [%d]", scan_res->num);
 701         wpa_bss_update_start(wpa_s);
 702         for (i = 0; i < scan_res->num; i++)
 703         {
 704         /*
 705          * September, 30th 2011. TIZEN
 706          *
 707          * TIZEN doesn't want to get scan results
 708          * which are under signal level -85dbm.
 709          * Therefore, scan results are filtered by signal level under -85dbm
 710          */
 711                 if( scan_res->res[i]->level < 170)
 712                         continue;
 713                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
 714         }
 715         wpa_bss_update_end(wpa_s, info, new_scan);
 716
 717         return scan_res;
 718 }
 719
 720
 721 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
 722 {
 723         struct wpa_scan_results *scan_res;
 724         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
 725         if (scan_res == NULL)
 726                 return -1;
 727         wpa_scan_results_free(scan_res);
 728
 729         return 0;
 730 }
 731
 732
 733 void wpa_scan_results_free(struct wpa_scan_results *res)
 734 {
 735         size_t i;
 736
 737         if (res == NULL)
 738                 return;
 739
 740         for (i = 0; i < res->num; i++)
 741                 os_free(res->res[i]);
 742         os_free(res->res);
 743         os_free(res);
 744 }