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         int wps = 0;
 247 #ifdef CONFIG_WPS
 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                 return;
 257         }
 258
 259         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 260             !wpa_s->scan_req) {
 261                 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
 262                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 263                 return;
 264         }
 265
 266         if (wpa_s->conf->ap_scan != 0 &&
 267             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 268                 wpa_printf(MSG_DEBUG, "Using wired authentication - "
 269                            "overriding ap_scan configuration");
 270                 wpa_s->conf->ap_scan = 0;
 271                 wpas_notify_ap_scan_changed(wpa_s);
 272         }
 273
 274         if (wpa_s->conf->ap_scan == 0) {
 275                 wpa_supplicant_gen_assoc_event(wpa_s);
 276                 return;
 277         }
 278
 279         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 280             wpa_s->conf->ap_scan == 2)
 281                 max_ssids = 1;
 282         else {
 283                 max_ssids = wpa_s->max_scan_ssids;
 284                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 285                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 286         }
 287
 288 #ifdef CONFIG_WPS
 289         wps = wpas_wps_in_use(wpa_s->conf, &req_type);
 290 #endif /* CONFIG_WPS */
 291
 292         if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
 293             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
 294             wps != 2 && !wpa_s->conf->filter_ssids &&
 295             !wpa_s->connect_without_scan) {
 296                 wpa_s->scan_res_tried++;
 297                 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
 298                            "first without requesting a new scan to speed up "
 299                            "initial association");
 300                 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
 301                 return;
 302         }
 303
 304         scan_req = wpa_s->scan_req;
 305         wpa_s->scan_req = 0;
 306
 307         os_memset(&params, 0, sizeof(params));
 308
 309         prev_state = wpa_s->wpa_state;
 310         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 311             wpa_s->wpa_state == WPA_INACTIVE)
 312                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 313
 314         /* Find the starting point from which to continue scanning */
 315         ssid = wpa_s->conf->ssid;
 316         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 317                 while (ssid) {
 318                         if (ssid == wpa_s->prev_scan_ssid) {
 319                                 ssid = ssid->next;
 320                                 break;
 321                         }
 322                         ssid = ssid->next;
 323                 }
 324         }
 325
 326         if (scan_req != 2 && (wpa_s->conf->ap_scan == 2 ||
 327                               wpa_s->connect_without_scan)) {
 328                 wpa_s->connect_without_scan = 0;
 329                 wpa_supplicant_assoc_try(wpa_s, ssid);
 330                 return;
 331         } else if (wpa_s->conf->ap_scan == 2) {
 332                 /*
 333                  * User-initiated scan request in ap_scan == 2; scan with
 334                  * wildcard SSID.
 335                  */
 336                 ssid = NULL;
 337         } else {
 338                 struct wpa_ssid *start = ssid, *tssid;
 339                 int freqs_set = 0;
 340                 if (ssid == NULL && max_ssids > 1)
 341                         ssid = wpa_s->conf->ssid;
 342                 while (ssid) {
 343                         if (!ssid->disabled && ssid->scan_ssid) {
 344                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 345                                                   ssid->ssid, ssid->ssid_len);
 346                                 params.ssids[params.num_ssids].ssid =
 347                                         ssid->ssid;
 348                                 params.ssids[params.num_ssids].ssid_len =
 349                                         ssid->ssid_len;
 350                                 params.num_ssids++;
 351                                 if (params.num_ssids + 1 >= max_ssids)
 352                                         break;
 353                         }
 354                         ssid = ssid->next;
 355                         if (ssid == start)
 356                                 break;
 357                         if (ssid == NULL && max_ssids > 1 &&
 358                             start != wpa_s->conf->ssid)
 359                                 ssid = wpa_s->conf->ssid;
 360                 }
 361
 362                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 363                         if (tssid->disabled)
 364                                 continue;
 365                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 366                                 int_array_concat(&params.freqs,
 367                                                  tssid->scan_freq);
 368                         } else {
 369                                 os_free(params.freqs);
 370                                 params.freqs = NULL;
 371                         }
 372                         freqs_set = 1;
 373                 }
 374                 int_array_sort_unique(params.freqs);
 375         }
 376
 377         if (ssid) {
 378                 wpa_s->prev_scan_ssid = ssid;
 379                 if (max_ssids > 1) {
 380                         wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
 381                                    "scan request");
 382                         params.num_ssids++;
 383                 }
 384                 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
 385         } else {
 386                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 387                 params.num_ssids++;
 388                 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
 389         }
 390
 391 #ifdef CONFIG_WPS
 392         if (params.freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 393                 /*
 394                  * Optimize post-provisioning scan based on channel used
 395                  * during provisioning.
 396                  */
 397                 wpa_printf(MSG_DEBUG, "WPS: Scan only frequency %u MHz that "
 398                            "was used during provisioning", wpa_s->wps_freq);
 399                 params.freqs = os_zalloc(2 * sizeof(int));
 400                 if (params.freqs)
 401                         params.freqs[0] = wpa_s->wps_freq;
 402                 wpa_s->after_wps--;
 403         }
 404
 405         if (wps) {
 406                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 407                                                 wpa_s->wps->uuid, req_type);
 408                 if (wps_ie) {
 409                         params.extra_ies = wpabuf_head(wps_ie);
 410                         params.extra_ies_len = wpabuf_len(wps_ie);
 411                 }
 412         }
 413 #endif /* CONFIG_WPS */
 414
 415         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 416                 wpa_s->conf, &params.num_filter_ssids);
 417
 418         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 419
 420         wpabuf_free(wps_ie);
 421         os_free(params.freqs);
 422         os_free(params.filter_ssids);
 423
 424         if (ret) {
 425                 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
 426                 if (prev_state != wpa_s->wpa_state)
 427                         wpa_supplicant_set_state(wpa_s, prev_state);
 428                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 429         } else
 430                 wpa_s->scan_runs++;
 431 }
 432
 433
 434 /**
 435  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 436  * @wpa_s: Pointer to wpa_supplicant data
 437  * @sec: Number of seconds after which to scan
 438  * @usec: Number of microseconds after which to scan
 439  *
 440  * This function is used to schedule a scan for neighboring access points after
 441  * the specified time.
 442  */
 443 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 444 {
 445         /* If there's at least one network that should be specifically scanned
 446          * then don't cancel the scan and reschedule.  Some drivers do
 447          * background scanning which generates frequent scan results, and that
 448          * causes the specific SSID scan to get continually pushed back and
 449          * never happen, which causes hidden APs to never get probe-scanned.
 450          */
 451         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 452             wpa_s->conf->ap_scan == 1) {
 453                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 454
 455                 while (ssid) {
 456                         if (!ssid->disabled && ssid->scan_ssid)
 457                                 break;
 458                         ssid = ssid->next;
 459                 }
 460                 if (ssid) {
 461                         wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 462                                 "ensure that specific SSID scans occur");
 463                         return;
 464                 }
 465         }
 466
 467         wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 468                 sec, usec);
 469         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 470         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 471 }
 472
 473
 474 /**
 475  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 476  * @wpa_s: Pointer to wpa_supplicant data
 477  *
 478  * This function is used to cancel a scan request scheduled with
 479  * wpa_supplicant_req_scan().
 480  */
 481 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 482 {
 483         wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 484         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 485 }
 486
 487
 488 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 489                                     int scanning)
 490 {
 491         if (wpa_s->scanning != scanning) {
 492                 wpa_s->scanning = scanning;
 493                 wpas_notify_scanning(wpa_s);
 494         }
 495 }
 496
 497
 498 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 499 {
 500         int rate = 0;
 501         const u8 *ie;
 502         int i;
 503
 504         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 505         for (i = 0; ie && i < ie[1]; i++) {
 506                 if ((ie[i + 2] & 0x7f) > rate)
 507                         rate = ie[i + 2] & 0x7f;
 508         }
 509
 510         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 511         for (i = 0; ie && i < ie[1]; i++) {
 512                 if ((ie[i + 2] & 0x7f) > rate)
 513                         rate = ie[i + 2] & 0x7f;
 514         }
 515
 516         return rate;
 517 }
 518
 519
 520 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 521 {
 522         const u8 *end, *pos;
 523
 524         pos = (const u8 *) (res + 1);
 525         end = pos + res->ie_len;
 526
 527         while (pos + 1 < end) {
 528                 if (pos + 2 + pos[1] > end)
 529                         break;
 530                 if (pos[0] == ie)
 531                         return pos;
 532                 pos += 2 + pos[1];
 533         }
 534
 535         return NULL;
 536 }
 537
 538
 539 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 540                                   u32 vendor_type)
 541 {
 542         const u8 *end, *pos;
 543
 544         pos = (const u8 *) (res + 1);
 545         end = pos + res->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                         return pos;
 553                 pos += 2 + pos[1];
 554         }
 555
 556         return NULL;
 557 }
 558
 559
 560 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 561                                              u32 vendor_type)
 562 {
 563         struct wpabuf *buf;
 564         const u8 *end, *pos;
 565
 566         buf = wpabuf_alloc(res->ie_len);
 567         if (buf == NULL)
 568                 return NULL;
 569
 570         pos = (const u8 *) (res + 1);
 571         end = pos + res->ie_len;
 572
 573         while (pos + 1 < end) {
 574                 if (pos + 2 + pos[1] > end)
 575                         break;
 576                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 577                     vendor_type == WPA_GET_BE32(&pos[2]))
 578                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 579                 pos += 2 + pos[1];
 580         }
 581
 582         if (wpabuf_len(buf) == 0) {
 583                 wpabuf_free(buf);
 584                 buf = NULL;
 585         }
 586
 587         return buf;
 588 }
 589
 590
 591 /* Compare function for sorting scan results. Return >0 if @b is considered
 592  * better. */
 593 static int wpa_scan_result_compar(const void *a, const void *b)
 594 {
 595         struct wpa_scan_res **_wa = (void *) a;
 596         struct wpa_scan_res **_wb = (void *) b;
 597         struct wpa_scan_res *wa = *_wa;
 598         struct wpa_scan_res *wb = *_wb;
 599         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 600
 601         /* WPA/WPA2 support preferred */
 602         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 603                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 604         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 605                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
 606
 607         if (wpa_b && !wpa_a)
 608                 return 1;
 609         if (!wpa_b && wpa_a)
 610                 return -1;
 611
 612         /* privacy support preferred */
 613         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
 614             (wb->caps & IEEE80211_CAP_PRIVACY))
 615                 return 1;
 616         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
 617             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
 618                 return -1;
 619
 620         /* best/max rate preferred if signal level close enough XXX */
 621         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
 622             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
 623                 maxrate_a = wpa_scan_get_max_rate(wa);
 624                 maxrate_b = wpa_scan_get_max_rate(wb);
 625                 if (maxrate_a != maxrate_b)
 626                         return maxrate_b - maxrate_a;
 627         }
 628
 629         /* use freq for channel preference */
 630
 631         /* all things being equal, use signal level; if signal levels are
 632          * identical, use quality values since some drivers may only report
 633          * that value and leave the signal level zero */
 634         if (wb->level == wa->level)
 635                 return wb->qual - wa->qual;
 636         return wb->level - wa->level;
 637 }
 638
 639
 640 /**
 641  * wpa_supplicant_get_scan_results - Get scan results
 642  * @wpa_s: Pointer to wpa_supplicant data
 643  * @info: Information about what was scanned or %NULL if not available
 644  * @new_scan: Whether a new scan was performed
 645  * Returns: Scan results, %NULL on failure
 646  *
 647  * This function request the current scan results from the driver and updates
 648  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
 649  * results with wpa_scan_results_free().
 650  */
 651 struct wpa_scan_results *
 652 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
 653                                 struct scan_info *info, int new_scan)
 654 {
 655         struct wpa_scan_results *scan_res;
 656         size_t i;
 657
 658         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 659                 scan_res = ieee80211_sta_get_scan_results(wpa_s);
 660         else
 661                 scan_res = wpa_drv_get_scan_results2(wpa_s);
 662         if (scan_res == NULL) {
 663                 wpa_printf(MSG_DEBUG, "Failed to get scan results");
 664                 return NULL;
 665         }
 666
 667         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
 668               wpa_scan_result_compar);
 669
 670         wpa_bss_update_start(wpa_s);
 671         for (i = 0; i < scan_res->num; i++)
 672                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
 673         wpa_bss_update_end(wpa_s, info, new_scan);
 674
 675         return scan_res;
 676 }
 677
 678
 679 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
 680 {
 681         struct wpa_scan_results *scan_res;
 682         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
 683         if (scan_res == NULL)
 684                 return -1;
 685         wpa_scan_results_free(scan_res);
 686
 687         return 0;
 688 }
 689
 690
 691 void wpa_scan_results_free(struct wpa_scan_results *res)
 692 {
 693         size_t i;
 694
 695         if (res == NULL)
 696                 return;
 697
 698         for (i = 0; i < res->num; i++)
 699                 os_free(res->res[i]);
 700         os_free(res->res);
 701         os_free(res);
 702 }