wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2012, 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 "common/wpa_ctrl.h"
  15 #include "config.h"
  16 #include "wpa_supplicant_i.h"
  17 #include "driver_i.h"
  18 #include "wps_supplicant.h"
  19 #include "p2p_supplicant.h"
  20 #include "p2p/p2p.h"
  21 #include "hs20_supplicant.h"
  22 #include "notify.h"
  23 #include "bss.h"
  24 #include "gas_query.h"
  25 #include "scan.h"
  26
  27
  28 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  29 {
  30         struct wpa_ssid *ssid;
  31         union wpa_event_data data;
  32
  33         ssid = wpa_supplicant_get_ssid(wpa_s);
  34         if (ssid == NULL)
  35                 return;
  36
  37         if (wpa_s->current_ssid == NULL) {
  38                 wpa_s->current_ssid = ssid;
  39                 if (wpa_s->current_ssid != NULL)
  40                         wpas_notify_network_changed(wpa_s);
  41         }
  42         wpa_supplicant_initiate_eapol(wpa_s);
  43         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  44                 "network - generating associated event");
  45         os_memset(&data, 0, sizeof(data));
  46         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  47 }
  48
  49
  50 #ifdef CONFIG_WPS
  51 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  52                            enum wps_request_type *req_type)
  53 {
  54         struct wpa_ssid *ssid;
  55         int wps = 0;
  56
  57         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  58                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  59                         continue;
  60
  61                 wps = 1;
  62                 *req_type = wpas_wps_get_req_type(ssid);
  63                 if (!ssid->eap.phase1)
  64                         continue;
  65
  66                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  67                         return 2;
  68         }
  69
  70 #ifdef CONFIG_P2P
  71         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
  72             !wpa_s->conf->p2p_disabled) {
  73                 wpa_s->wps->dev.p2p = 1;
  74                 if (!wps) {
  75                         wps = 1;
  76                         *req_type = WPS_REQ_ENROLLEE_INFO;
  77                 }
  78         }
  79 #endif /* CONFIG_P2P */
  80
  81         return wps;
  82 }
  83 #endif /* CONFIG_WPS */
  84
  85
  86 /**
  87  * wpa_supplicant_enabled_networks - Check whether there are enabled networks
  88  * @wpa_s: Pointer to wpa_supplicant data
  89  * Returns: 0 if no networks are enabled, >0 if networks are enabled
  90  *
  91  * This function is used to figure out whether any networks (or Interworking
  92  * with enabled credentials and auto_interworking) are present in the current
  93  * configuration.
  94  */
  95 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  96 {
  97         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  98         int count = 0, disabled = 0;
  99         while (ssid) {
 100                 if (!wpas_network_disabled(wpa_s, ssid))
 101                         count++;
 102                 else
 103                         disabled++;
 104                 ssid = ssid->next;
 105         }
 106         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 107             wpa_s->conf->auto_interworking)
 108                 count++;
 109         if (count == 0 && disabled > 0) {
 110                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
 111                         "networks)", disabled);
 112         }
 113         return count;
 114 }
 115
 116
 117 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 118                                      struct wpa_ssid *ssid)
 119 {
 120         while (ssid) {
 121                 if (!wpas_network_disabled(wpa_s, ssid))
 122                         break;
 123                 ssid = ssid->next;
 124         }
 125
 126         /* ap_scan=2 mode - try to associate with each SSID. */
 127         if (ssid == NULL) {
 128                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 129                         "end of scan list - go back to beginning");
 130                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 131                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 132                 return;
 133         }
 134         if (ssid->next) {
 135                 /* Continue from the next SSID on the next attempt. */
 136                 wpa_s->prev_scan_ssid = ssid;
 137         } else {
 138                 /* Start from the beginning of the SSID list. */
 139                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 140         }
 141         wpa_supplicant_associate(wpa_s, NULL, ssid);
 142 }
 143
 144
 145 /**
 146  * wpa_supplicant_trigger_scan - Request driver to start a scan
 147  * @wpa_s: Pointer to wpa_supplicant data
 148  * @params: Scan parameters
 149  * Returns: 0 on success, -1 on failure
 150  */
 151 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 152                                 struct wpa_driver_scan_params *params)
 153 {
 154         int ret;
 155
 156         wpa_supplicant_notify_scanning(wpa_s, 1);
 157
 158         if (wpa_s->clear_driver_scan_cache)
 159                 params->only_new_results = 1;
 160         ret = wpa_drv_scan(wpa_s, params);
 161         if (ret) {
 162                 wpa_supplicant_notify_scanning(wpa_s, 0);
 163                 wpas_notify_scan_done(wpa_s, 0);
 164         } else {
 165                 os_get_reltime(&wpa_s->scan_trigger_time);
 166                 wpa_s->scan_runs++;
 167                 wpa_s->normal_scans++;
 168                 wpa_s->own_scan_requested = 1;
 169                 params->only_new_results = 0;
 170         }
 171
 172         return ret;
 173 }
 174
 175
 176 static void
 177 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 178 {
 179         struct wpa_supplicant *wpa_s = eloop_ctx;
 180
 181         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 182
 183         if (wpa_supplicant_req_sched_scan(wpa_s))
 184                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 185 }
 186
 187
 188 static void
 189 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 190 {
 191         struct wpa_supplicant *wpa_s = eloop_ctx;
 192
 193         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 194
 195         wpa_s->sched_scan_timed_out = 1;
 196         wpa_supplicant_cancel_sched_scan(wpa_s);
 197 }
 198
 199
 200 int wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 201                                     struct wpa_driver_scan_params *params,
 202                                     int interval)
 203 {
 204         int ret;
 205
 206         wpa_supplicant_notify_scanning(wpa_s, 1);
 207         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 208         if (ret)
 209                 wpa_supplicant_notify_scanning(wpa_s, 0);
 210         else
 211                 wpa_s->sched_scanning = 1;
 212
 213         return ret;
 214 }
 215
 216
 217 int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 218 {
 219         int ret;
 220
 221         ret = wpa_drv_stop_sched_scan(wpa_s);
 222         if (ret) {
 223                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 224                 /* TODO: what to do if stopping fails? */
 225                 return -1;
 226         }
 227
 228         return ret;
 229 }
 230
 231
 232 static struct wpa_driver_scan_filter *
 233 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 234 {
 235         struct wpa_driver_scan_filter *ssids;
 236         struct wpa_ssid *ssid;
 237         size_t count;
 238
 239         *num_ssids = 0;
 240         if (!conf->filter_ssids)
 241                 return NULL;
 242
 243         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 244                 if (ssid->ssid && ssid->ssid_len)
 245                         count++;
 246         }
 247         if (count == 0)
 248                 return NULL;
 249         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 250         if (ssids == NULL)
 251                 return NULL;
 252
 253         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 254                 if (!ssid->ssid || !ssid->ssid_len)
 255                         continue;
 256                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 257                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 258                 (*num_ssids)++;
 259         }
 260
 261         return ssids;
 262 }
 263
 264
 265 static void wpa_supplicant_optimize_freqs(
 266         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 267 {
 268 #ifdef CONFIG_P2P
 269         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 270             wpa_s->go_params) {
 271                 /* Optimize provisioning state scan based on GO information */
 272                 if (wpa_s->p2p_in_provisioning < 5 &&
 273                     wpa_s->go_params->freq > 0) {
 274                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 275                                 "preferred frequency %d MHz",
 276                                 wpa_s->go_params->freq);
 277                         params->freqs = os_zalloc(2 * sizeof(int));
 278                         if (params->freqs)
 279                                 params->freqs[0] = wpa_s->go_params->freq;
 280                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 281                            wpa_s->go_params->freq_list[0]) {
 282                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 283                                 "channels");
 284                         int_array_concat(&params->freqs,
 285                                          wpa_s->go_params->freq_list);
 286                         if (params->freqs)
 287                                 int_array_sort_unique(params->freqs);
 288                 }
 289                 wpa_s->p2p_in_provisioning++;
 290         }
 291 #endif /* CONFIG_P2P */
 292
 293 #ifdef CONFIG_WPS
 294         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 295                 /*
 296                  * Optimize post-provisioning scan based on channel used
 297                  * during provisioning.
 298                  */
 299                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 300                         "that was used during provisioning", wpa_s->wps_freq);
 301                 params->freqs = os_zalloc(2 * sizeof(int));
 302                 if (params->freqs)
 303                         params->freqs[0] = wpa_s->wps_freq;
 304                 wpa_s->after_wps--;
 305         } else if (wpa_s->after_wps)
 306                 wpa_s->after_wps--;
 307
 308         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 309         {
 310                 /* Optimize provisioning scan based on already known channel */
 311                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 312                         wpa_s->wps_freq);
 313                 params->freqs = os_zalloc(2 * sizeof(int));
 314                 if (params->freqs)
 315                         params->freqs[0] = wpa_s->wps_freq;
 316                 wpa_s->known_wps_freq = 0; /* only do this once */
 317         }
 318 #endif /* CONFIG_WPS */
 319 }
 320
 321
 322 #ifdef CONFIG_INTERWORKING
 323 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 324                                            struct wpabuf *buf)
 325 {
 326         if (wpa_s->conf->interworking == 0)
 327                 return;
 328
 329         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 330         wpabuf_put_u8(buf, 4);
 331         wpabuf_put_u8(buf, 0x00);
 332         wpabuf_put_u8(buf, 0x00);
 333         wpabuf_put_u8(buf, 0x00);
 334         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 335
 336         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 337         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 338                       1 + ETH_ALEN);
 339         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 340         /* No Venue Info */
 341         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 342                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 343 }
 344 #endif /* CONFIG_INTERWORKING */
 345
 346
 347 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 348 {
 349         struct wpabuf *extra_ie = NULL;
 350 #ifdef CONFIG_WPS
 351         int wps = 0;
 352         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 353 #endif /* CONFIG_WPS */
 354
 355 #ifdef CONFIG_INTERWORKING
 356         if (wpa_s->conf->interworking &&
 357             wpabuf_resize(&extra_ie, 100) == 0)
 358                 wpas_add_interworking_elements(wpa_s, extra_ie);
 359 #endif /* CONFIG_INTERWORKING */
 360
 361 #ifdef CONFIG_WPS
 362         wps = wpas_wps_in_use(wpa_s, &req_type);
 363
 364         if (wps) {
 365                 struct wpabuf *wps_ie;
 366                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 367                                                 DEV_PW_DEFAULT,
 368                                                 &wpa_s->wps->dev,
 369                                                 wpa_s->wps->uuid, req_type,
 370                                                 0, NULL);
 371                 if (wps_ie) {
 372                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 373                                 wpabuf_put_buf(extra_ie, wps_ie);
 374                         wpabuf_free(wps_ie);
 375                 }
 376         }
 377
 378 #ifdef CONFIG_P2P
 379         if (wps) {
 380                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 381                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 382                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 383         }
 384 #endif /* CONFIG_P2P */
 385
 386 #endif /* CONFIG_WPS */
 387
 388 #ifdef CONFIG_HS20
 389         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 390                 wpas_hs20_add_indication(extra_ie);
 391 #endif /* CONFIG_HS20 */
 392
 393         return extra_ie;
 394 }
 395
 396
 397 #ifdef CONFIG_P2P
 398
 399 /*
 400  * Check whether there are any enabled networks or credentials that could be
 401  * used for a non-P2P connection.
 402  */
 403 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 404 {
 405         struct wpa_ssid *ssid;
 406
 407         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 408                 if (wpas_network_disabled(wpa_s, ssid))
 409                         continue;
 410                 if (!ssid->p2p_group)
 411                         return 1;
 412         }
 413
 414         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 415             wpa_s->conf->auto_interworking)
 416                 return 1;
 417
 418         return 0;
 419 }
 420
 421 #endif /* CONFIG_P2P */
 422
 423
 424 static struct hostapd_hw_modes * get_mode(struct hostapd_hw_modes *modes,
 425                                           u16 num_modes,
 426                                           enum hostapd_hw_mode mode)
 427 {
 428         u16 i;
 429
 430         for (i = 0; i < num_modes; i++) {
 431                 if (modes[i].mode == mode)
 432                         return &modes[i];
 433         }
 434
 435         return NULL;
 436 }
 437
 438
 439 static void wpa_setband_scan_freqs_list(struct wpa_supplicant *wpa_s,
 440                                         enum hostapd_hw_mode band,
 441                                         struct wpa_driver_scan_params *params)
 442 {
 443         /* Include only supported channels for the specified band */
 444         struct hostapd_hw_modes *mode;
 445         int count, i;
 446
 447         mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, band);
 448         if (mode == NULL) {
 449                 /* No channels supported in this band - use empty list */
 450                 params->freqs = os_zalloc(sizeof(int));
 451                 return;
 452         }
 453
 454         params->freqs = os_zalloc((mode->num_channels + 1) * sizeof(int));
 455         if (params->freqs == NULL)
 456                 return;
 457         for (count = 0, i = 0; i < mode->num_channels; i++) {
 458                 if (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED)
 459                         continue;
 460                 params->freqs[count++] = mode->channels[i].freq;
 461         }
 462 }
 463
 464
 465 static void wpa_setband_scan_freqs(struct wpa_supplicant *wpa_s,
 466                                    struct wpa_driver_scan_params *params)
 467 {
 468         if (wpa_s->hw.modes == NULL)
 469                 return; /* unknown what channels the driver supports */
 470         if (params->freqs)
 471                 return; /* already using a limited channel set */
 472         if (wpa_s->setband == WPA_SETBAND_5G)
 473                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211A,
 474                                             params);
 475         else if (wpa_s->setband == WPA_SETBAND_2G)
 476                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211G,
 477                                             params);
 478 }
 479
 480
 481 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 482 {
 483         struct wpa_supplicant *wpa_s = eloop_ctx;
 484         struct wpa_ssid *ssid;
 485         int ret;
 486         struct wpabuf *extra_ie = NULL;
 487         struct wpa_driver_scan_params params;
 488         struct wpa_driver_scan_params *scan_params;
 489         size_t max_ssids;
 490         enum wpa_states prev_state;
 491
 492         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 493                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 494                 wpas_p2p_continue_after_scan(wpa_s);
 495                 return;
 496         }
 497
 498         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 499                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 500                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 501                 wpas_p2p_continue_after_scan(wpa_s);
 502                 return;
 503         }
 504
 505         if (wpa_s->scanning) {
 506                 /*
 507                  * If we are already in scanning state, we shall reschedule the
 508                  * the incoming scan request.
 509                  */
 510                 wpa_dbg(wpa_s, MSG_DEBUG, "Already scanning - Reschedule the incoming scan req");
 511                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 512                 return;
 513         }
 514
 515         if (wpa_s->external_scan_running) {
 516                 struct os_reltime now, diff;
 517                 os_get_reltime(&now);
 518                 os_reltime_sub(&now, &wpa_s->scan_start_time, &diff);
 519                 if (diff.sec < 30) {
 520                         wpa_dbg(wpa_s, MSG_DEBUG, "Externally triggered scan running - Reschedule the incoming scan req");
 521                         wpa_supplicant_req_scan(wpa_s, 1, 0);
 522                         return;
 523                 }
 524         }
 525
 526         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 527             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 528                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 529                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 530                 wpas_p2p_continue_after_scan(wpa_s);
 531                 return;
 532         }
 533
 534         if (wpa_s->conf->ap_scan != 0 &&
 535             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 536                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 537                         "overriding ap_scan configuration");
 538                 wpa_s->conf->ap_scan = 0;
 539                 wpas_notify_ap_scan_changed(wpa_s);
 540         }
 541
 542         if (wpa_s->conf->ap_scan == 0) {
 543                 wpa_supplicant_gen_assoc_event(wpa_s);
 544                 return;
 545         }
 546
 547 #ifdef CONFIG_P2P
 548         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
 549                 if (wpa_s->sta_scan_pending &&
 550                     wpas_p2p_in_progress(wpa_s) == 2 &&
 551                     wpa_s->global->p2p_cb_on_scan_complete) {
 552                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 553                                 "mode scan during P2P search");
 554                 } else {
 555                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 556                                 "while P2P operation is in progress");
 557                         wpa_s->sta_scan_pending = 1;
 558                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 559                         return;
 560                 }
 561         }
 562 #endif /* CONFIG_P2P */
 563
 564 #ifdef CONFIG_GAS
 565         if (gas_query_in_progress(wpa_s->gas)) {
 566                 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
 567                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 568                 return;
 569         }
 570 #endif /* CONFIG_GAS */
 571
 572         if (wpa_s->conf->ap_scan == 2)
 573                 max_ssids = 1;
 574         else {
 575                 max_ssids = wpa_s->max_scan_ssids;
 576                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 577                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 578         }
 579
 580         wpa_s->last_scan_req = wpa_s->scan_req;
 581         wpa_s->scan_req = NORMAL_SCAN_REQ;
 582
 583         os_memset(&params, 0, sizeof(params));
 584
 585         prev_state = wpa_s->wpa_state;
 586         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 587             wpa_s->wpa_state == WPA_INACTIVE)
 588                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 589
 590         /*
 591          * If autoscan has set its own scanning parameters
 592          */
 593         if (wpa_s->autoscan_params != NULL) {
 594                 scan_params = wpa_s->autoscan_params;
 595                 goto scan;
 596         }
 597
 598         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 599             wpa_s->connect_without_scan) {
 600                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 601                         if (ssid == wpa_s->connect_without_scan)
 602                                 break;
 603                 }
 604                 wpa_s->connect_without_scan = NULL;
 605                 if (ssid) {
 606                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 607                                    "without scan step");
 608                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 609                         return;
 610                 }
 611         }
 612
 613 #ifdef CONFIG_P2P
 614         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 615             wpa_s->go_params) {
 616                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during P2P group formation (p2p_in_provisioning=%d show_group_started=%d)",
 617                            wpa_s->p2p_in_provisioning,
 618                            wpa_s->show_group_started);
 619                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 620                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 621                 params.num_ssids = 1;
 622                 goto ssid_list_set;
 623         }
 624 #endif /* CONFIG_P2P */
 625
 626         /* Find the starting point from which to continue scanning */
 627         ssid = wpa_s->conf->ssid;
 628         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 629                 while (ssid) {
 630                         if (ssid == wpa_s->prev_scan_ssid) {
 631                                 ssid = ssid->next;
 632                                 break;
 633                         }
 634                         ssid = ssid->next;
 635                 }
 636         }
 637
 638         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 639             wpa_s->conf->ap_scan == 2) {
 640                 wpa_s->connect_without_scan = NULL;
 641                 wpa_s->prev_scan_wildcard = 0;
 642                 wpa_supplicant_assoc_try(wpa_s, ssid);
 643                 return;
 644         } else if (wpa_s->conf->ap_scan == 2) {
 645                 /*
 646                  * User-initiated scan request in ap_scan == 2; scan with
 647                  * wildcard SSID.
 648                  */
 649                 ssid = NULL;
 650         } else {
 651                 struct wpa_ssid *start = ssid, *tssid;
 652                 int freqs_set = 0;
 653                 if (ssid == NULL && max_ssids > 1)
 654                         ssid = wpa_s->conf->ssid;
 655                 while (ssid) {
 656                         if (!wpas_network_disabled(wpa_s, ssid) &&
 657                             ssid->scan_ssid) {
 658                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 659                                                   ssid->ssid, ssid->ssid_len);
 660                                 params.ssids[params.num_ssids].ssid =
 661                                         ssid->ssid;
 662                                 params.ssids[params.num_ssids].ssid_len =
 663                                         ssid->ssid_len;
 664                                 params.num_ssids++;
 665                                 if (params.num_ssids + 1 >= max_ssids)
 666                                         break;
 667                         }
 668                         ssid = ssid->next;
 669                         if (ssid == start)
 670                                 break;
 671                         if (ssid == NULL && max_ssids > 1 &&
 672                             start != wpa_s->conf->ssid)
 673                                 ssid = wpa_s->conf->ssid;
 674                 }
 675
 676                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 677                         if (wpas_network_disabled(wpa_s, tssid))
 678                                 continue;
 679                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 680                                 int_array_concat(&params.freqs,
 681                                                  tssid->scan_freq);
 682                         } else {
 683                                 os_free(params.freqs);
 684                                 params.freqs = NULL;
 685                         }
 686                         freqs_set = 1;
 687                 }
 688                 int_array_sort_unique(params.freqs);
 689         }
 690
 691         if (ssid && max_ssids == 1) {
 692                 /*
 693                  * If the driver is limited to 1 SSID at a time interleave
 694                  * wildcard SSID scans with specific SSID scans to avoid
 695                  * waiting a long time for a wildcard scan.
 696                  */
 697                 if (!wpa_s->prev_scan_wildcard) {
 698                         params.ssids[0].ssid = NULL;
 699                         params.ssids[0].ssid_len = 0;
 700                         wpa_s->prev_scan_wildcard = 1;
 701                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 702                                 "wildcard SSID (Interleave with specific)");
 703                 } else {
 704                         wpa_s->prev_scan_ssid = ssid;
 705                         wpa_s->prev_scan_wildcard = 0;
 706                         wpa_dbg(wpa_s, MSG_DEBUG,
 707                                 "Starting AP scan for specific SSID: %s",
 708                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 709                 }
 710         } else if (ssid) {
 711                 /* max_ssids > 1 */
 712
 713                 wpa_s->prev_scan_ssid = ssid;
 714                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 715                         "the scan request");
 716                 params.num_ssids++;
 717         } else if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
 718                    wpa_s->manual_scan_passive && params.num_ssids == 0) {
 719                 wpa_dbg(wpa_s, MSG_DEBUG, "Use passive scan based on manual request");
 720         } else {
 721                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 722                 params.num_ssids++;
 723                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 724                         "SSID");
 725         }
 726 #ifdef CONFIG_P2P
 727 ssid_list_set:
 728 #endif /* CONFIG_P2P */
 729
 730         wpa_supplicant_optimize_freqs(wpa_s, &params);
 731         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 732
 733         if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
 734             wpa_s->manual_scan_only_new)
 735                 params.only_new_results = 1;
 736
 737         if (wpa_s->last_scan_req == MANUAL_SCAN_REQ && params.freqs == NULL &&
 738             wpa_s->manual_scan_freqs) {
 739                 wpa_dbg(wpa_s, MSG_DEBUG, "Limit manual scan to specified channels");
 740                 params.freqs = wpa_s->manual_scan_freqs;
 741                 wpa_s->manual_scan_freqs = NULL;
 742         }
 743
 744         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 745                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 746                         "generated frequency list");
 747                 params.freqs = wpa_s->next_scan_freqs;
 748         } else
 749                 os_free(wpa_s->next_scan_freqs);
 750         wpa_s->next_scan_freqs = NULL;
 751         wpa_setband_scan_freqs(wpa_s, &params);
 752
 753         /* See if user specified frequencies. If so, scan only those. */
 754         if (wpa_s->conf->freq_list && !params.freqs) {
 755                 wpa_dbg(wpa_s, MSG_DEBUG,
 756                         "Optimize scan based on conf->freq_list");
 757                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 758         }
 759
 760         /* Use current associated channel? */
 761         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 762                 unsigned int num = wpa_s->num_multichan_concurrent;
 763
 764                 params.freqs = os_calloc(num + 1, sizeof(int));
 765                 if (params.freqs) {
 766                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 767                         if (num > 0) {
 768                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
 769                                         "current operating channels since "
 770                                         "scan_cur_freq is enabled");
 771                         } else {
 772                                 os_free(params.freqs);
 773                                 params.freqs = NULL;
 774                         }
 775                 }
 776         }
 777
 778         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 779                 wpa_s->conf, &params.num_filter_ssids);
 780         if (extra_ie) {
 781                 params.extra_ies = wpabuf_head(extra_ie);
 782                 params.extra_ies_len = wpabuf_len(extra_ie);
 783         }
 784
 785 #ifdef CONFIG_P2P
 786         if (wpa_s->p2p_in_provisioning ||
 787             (wpa_s->show_group_started && wpa_s->go_params)) {
 788                 /*
 789                  * The interface may not yet be in P2P mode, so we have to
 790                  * explicitly request P2P probe to disable CCK rates.
 791                  */
 792                 params.p2p_probe = 1;
 793         }
 794 #endif /* CONFIG_P2P */
 795
 796         scan_params = &params;
 797
 798 scan:
 799 #ifdef CONFIG_P2P
 800         /*
 801          * If the driver does not support multi-channel concurrency and a
 802          * virtual interface that shares the same radio with the wpa_s interface
 803          * is operating there may not be need to scan other channels apart from
 804          * the current operating channel on the other virtual interface. Filter
 805          * out other channels in case we are trying to find a connection for a
 806          * station interface when we are not configured to prefer station
 807          * connection and a concurrent operation is already in process.
 808          */
 809         if (wpa_s->scan_for_connection &&
 810             wpa_s->last_scan_req == NORMAL_SCAN_REQ &&
 811             !scan_params->freqs && !params.freqs &&
 812             wpas_is_p2p_prioritized(wpa_s) &&
 813             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 814             non_p2p_network_enabled(wpa_s)) {
 815                 unsigned int num = wpa_s->num_multichan_concurrent;
 816
 817                 params.freqs = os_calloc(num + 1, sizeof(int));
 818                 if (params.freqs) {
 819                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 820                         if (num > 0 && num == wpa_s->num_multichan_concurrent) {
 821                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
 822                         } else {
 823                                 os_free(params.freqs);
 824                                 params.freqs = NULL;
 825                         }
 826                 }
 827         }
 828 #endif /* CONFIG_P2P */
 829
 830         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 831
 832         if (ret && wpa_s->last_scan_req == MANUAL_SCAN_REQ && params.freqs &&
 833             !wpa_s->manual_scan_freqs) {
 834                 /* Restore manual_scan_freqs for the next attempt */
 835                 wpa_s->manual_scan_freqs = params.freqs;
 836                 params.freqs = NULL;
 837         }
 838
 839         wpabuf_free(extra_ie);
 840         os_free(params.freqs);
 841         os_free(params.filter_ssids);
 842
 843         if (ret) {
 844                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 845                 if (prev_state != wpa_s->wpa_state)
 846                         wpa_supplicant_set_state(wpa_s, prev_state);
 847                 /* Restore scan_req since we will try to scan again */
 848                 wpa_s->scan_req = wpa_s->last_scan_req;
 849                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 850         } else {
 851                 wpa_s->scan_for_connection = 0;
 852         }
 853 }
 854
 855
 856 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 857 {
 858         struct os_reltime remaining, new_int;
 859         int cancelled;
 860
 861         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 862                                              &remaining);
 863
 864         new_int.sec = sec;
 865         new_int.usec = 0;
 866         if (cancelled && os_reltime_before(&remaining, &new_int)) {
 867                 new_int.sec = remaining.sec;
 868                 new_int.usec = remaining.usec;
 869         }
 870
 871         if (cancelled) {
 872                 eloop_register_timeout(new_int.sec, new_int.usec,
 873                                        wpa_supplicant_scan, wpa_s, NULL);
 874         }
 875         wpa_s->scan_interval = sec;
 876 }
 877
 878
 879 /**
 880  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 881  * @wpa_s: Pointer to wpa_supplicant data
 882  * @sec: Number of seconds after which to scan
 883  * @usec: Number of microseconds after which to scan
 884  *
 885  * This function is used to schedule a scan for neighboring access points after
 886  * the specified time.
 887  */
 888 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 889 {
 890         if (eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL))
 891         {
 892                 wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d sec %d usec",
 893                         sec, usec);
 894                 return;
 895         }
 896
 897         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 898                 sec, usec);
 899         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 900         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 901 }
 902
 903
 904 /**
 905  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 906  * @wpa_s: Pointer to wpa_supplicant data
 907  * @sec: Number of seconds after which to scan
 908  * @usec: Number of microseconds after which to scan
 909  * Returns: 0 on success or -1 otherwise
 910  *
 911  * This function is used to schedule periodic scans for neighboring
 912  * access points after the specified time.
 913  */
 914 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 915                                       int sec, int usec)
 916 {
 917         if (!wpa_s->sched_scan_supported)
 918                 return -1;
 919
 920         eloop_register_timeout(sec, usec,
 921                                wpa_supplicant_delayed_sched_scan_timeout,
 922                                wpa_s, NULL);
 923
 924         return 0;
 925 }
 926
 927
 928 /**
 929  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 930  * @wpa_s: Pointer to wpa_supplicant data
 931  * Returns: 0 is sched_scan was started or -1 otherwise
 932  *
 933  * This function is used to schedule periodic scans for neighboring
 934  * access points repeating the scan continuously.
 935  */
 936 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 937 {
 938         struct wpa_driver_scan_params params;
 939         struct wpa_driver_scan_params *scan_params;
 940         enum wpa_states prev_state;
 941         struct wpa_ssid *ssid = NULL;
 942         struct wpabuf *extra_ie = NULL;
 943         int ret;
 944         unsigned int max_sched_scan_ssids;
 945         int wildcard = 0;
 946         int need_ssids;
 947
 948         if (!wpa_s->sched_scan_supported)
 949                 return -1;
 950
 951         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 952                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 953         else
 954                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 955         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 956                 return -1;
 957
 958         if (wpa_s->sched_scanning) {
 959                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 960                 return 0;
 961         }
 962
 963         need_ssids = 0;
 964         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 965                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 966                         /* Use wildcard SSID to find this network */
 967                         wildcard = 1;
 968                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 969                            ssid->ssid_len)
 970                         need_ssids++;
 971
 972 #ifdef CONFIG_WPS
 973                 if (!wpas_network_disabled(wpa_s, ssid) &&
 974                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 975                         /*
 976                          * Normal scan is more reliable and faster for WPS
 977                          * operations and since these are for short periods of
 978                          * time, the benefit of trying to use sched_scan would
 979                          * be limited.
 980                          */
 981                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 982                                 "sched_scan for WPS");
 983                         return -1;
 984                 }
 985 #endif /* CONFIG_WPS */
 986         }
 987         if (wildcard)
 988                 need_ssids++;
 989
 990         if (wpa_s->normal_scans < 3 &&
 991             (need_ssids <= wpa_s->max_scan_ssids ||
 992              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 993                 /*
 994                  * When normal scan can speed up operations, use that for the
 995                  * first operations before starting the sched_scan to allow
 996                  * user space sleep more. We do this only if the normal scan
 997                  * has functionality that is suitable for this or if the
 998                  * sched_scan does not have better support for multiple SSIDs.
 999                  */
1000                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1001                         "sched_scan for initial scans (normal_scans=%d)",
1002                         wpa_s->normal_scans);
1003                 return -1;
1004         }
1005
1006         os_memset(&params, 0, sizeof(params));
1007
1008         /* If we can't allocate space for the filters, we just don't filter */
1009         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1010                                         sizeof(struct wpa_driver_scan_filter));
1011
1012         prev_state = wpa_s->wpa_state;
1013         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1014             wpa_s->wpa_state == WPA_INACTIVE)
1015                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1016
1017         if (wpa_s->autoscan_params != NULL) {
1018                 scan_params = wpa_s->autoscan_params;
1019                 goto scan;
1020         }
1021
1022         /* Find the starting point from which to continue scanning */
1023         ssid = wpa_s->conf->ssid;
1024         if (wpa_s->prev_sched_ssid) {
1025                 while (ssid) {
1026                         if (ssid == wpa_s->prev_sched_ssid) {
1027                                 ssid = ssid->next;
1028                                 break;
1029                         }
1030                         ssid = ssid->next;
1031                 }
1032         }
1033
1034         if (!ssid || !wpa_s->prev_sched_ssid) {
1035                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1036                 if (wpa_s->conf->sched_scan_interval)
1037                         wpa_s->sched_scan_interval =
1038                                 wpa_s->conf->sched_scan_interval;
1039                 if (wpa_s->sched_scan_interval == 0)
1040                         wpa_s->sched_scan_interval = 10;
1041                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1042                 wpa_s->first_sched_scan = 1;
1043                 ssid = wpa_s->conf->ssid;
1044                 wpa_s->prev_sched_ssid = ssid;
1045         }
1046
1047         if (wildcard) {
1048                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1049                 params.num_ssids++;
1050         }
1051
1052         while (ssid) {
1053                 if (wpas_network_disabled(wpa_s, ssid))
1054                         goto next;
1055
1056                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1057                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1058                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1059                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1060                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1061                                   ssid->ssid, ssid->ssid_len);
1062                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1063                                 ssid->ssid_len;
1064                         params.num_filter_ssids++;
1065                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1066                 {
1067                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1068                                 "filter for sched_scan - drop filter");
1069                         os_free(params.filter_ssids);
1070                         params.filter_ssids = NULL;
1071                         params.num_filter_ssids = 0;
1072                 }
1073
1074                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1075                         if (params.num_ssids == max_sched_scan_ssids)
1076                                 break; /* only room for broadcast SSID */
1077                         wpa_dbg(wpa_s, MSG_DEBUG,
1078                                 "add to active scan ssid: %s",
1079                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1080                         params.ssids[params.num_ssids].ssid =
1081                                 ssid->ssid;
1082                         params.ssids[params.num_ssids].ssid_len =
1083                                 ssid->ssid_len;
1084                         params.num_ssids++;
1085                         if (params.num_ssids >= max_sched_scan_ssids) {
1086                                 wpa_s->prev_sched_ssid = ssid;
1087                                 do {
1088                                         ssid = ssid->next;
1089                                 } while (ssid &&
1090                                          (wpas_network_disabled(wpa_s, ssid) ||
1091                                           !ssid->scan_ssid));
1092                                 break;
1093                         }
1094                 }
1095
1096         next:
1097                 wpa_s->prev_sched_ssid = ssid;
1098                 ssid = ssid->next;
1099         }
1100
1101         if (params.num_filter_ssids == 0) {
1102                 os_free(params.filter_ssids);
1103                 params.filter_ssids = NULL;
1104         }
1105
1106         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1107         if (extra_ie) {
1108                 params.extra_ies = wpabuf_head(extra_ie);
1109                 params.extra_ies_len = wpabuf_len(extra_ie);
1110         }
1111
1112         scan_params = &params;
1113
1114 scan:
1115         if (ssid || !wpa_s->first_sched_scan) {
1116                 wpa_dbg(wpa_s, MSG_DEBUG,
1117                         "Starting sched scan: interval %d timeout %d",
1118                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1119         } else {
1120                 wpa_dbg(wpa_s, MSG_DEBUG,
1121                         "Starting sched scan: interval %d (no timeout)",
1122                         wpa_s->sched_scan_interval);
1123         }
1124
1125         wpa_setband_scan_freqs(wpa_s, scan_params);
1126
1127         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1128                                               wpa_s->sched_scan_interval);
1129         wpabuf_free(extra_ie);
1130         os_free(params.filter_ssids);
1131         if (ret) {
1132                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1133                 if (prev_state != wpa_s->wpa_state)
1134                         wpa_supplicant_set_state(wpa_s, prev_state);
1135                 return ret;
1136         }
1137
1138         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1139         if (ssid || !wpa_s->first_sched_scan) {
1140                 wpa_s->sched_scan_timed_out = 0;
1141                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1142                                        wpa_supplicant_sched_scan_timeout,
1143                                        wpa_s, NULL);
1144                 wpa_s->first_sched_scan = 0;
1145                 wpa_s->sched_scan_timeout /= 2;
1146                 wpa_s->sched_scan_interval *= 2;
1147                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1148                         wpa_s->sched_scan_interval = 10;
1149                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1150                 }
1151         }
1152
1153         /* If there is no more ssids, start next time from the beginning */
1154         if (!ssid)
1155                 wpa_s->prev_sched_ssid = NULL;
1156
1157         return 0;
1158 }
1159
1160
1161 /**
1162  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1163  * @wpa_s: Pointer to wpa_supplicant data
1164  *
1165  * This function is used to cancel a scan request scheduled with
1166  * wpa_supplicant_req_scan().
1167  */
1168 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1169 {
1170         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1171         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1172         wpas_p2p_continue_after_scan(wpa_s);
1173 }
1174
1175
1176 /**
1177  * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1178  * @wpa_s: Pointer to wpa_supplicant data
1179  *
1180  * This function is used to stop a delayed scheduled scan.
1181  */
1182 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1183 {
1184         if (!wpa_s->sched_scan_supported)
1185                 return;
1186
1187         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1188         eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1189                              wpa_s, NULL);
1190 }
1191
1192
1193 /**
1194  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1195  * @wpa_s: Pointer to wpa_supplicant data
1196  *
1197  * This function is used to stop a periodic scheduled scan.
1198  */
1199 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1200 {
1201         if (!wpa_s->sched_scanning)
1202                 return;
1203
1204         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1205         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1206         wpa_supplicant_stop_sched_scan(wpa_s);
1207 }
1208
1209
1210 /**
1211  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1212  * @wpa_s: Pointer to wpa_supplicant data
1213  * @scanning: Whether scanning is currently in progress
1214  *
1215  * This function is to generate scanning notifycations. It is called whenever
1216  * there may have been a change in scanning (scan started, completed, stopped).
1217  * wpas_notify_scanning() is called whenever the scanning state changed from the
1218  * previously notified state.
1219  */
1220 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1221                                     int scanning)
1222 {
1223         if (wpa_s->scanning != scanning) {
1224                 wpa_s->scanning = scanning;
1225                 wpas_notify_scanning(wpa_s);
1226         }
1227 }
1228
1229
1230 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1231 {
1232         int rate = 0;
1233         const u8 *ie;
1234         int i;
1235
1236         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1237         for (i = 0; ie && i < ie[1]; i++) {
1238                 if ((ie[i + 2] & 0x7f) > rate)
1239                         rate = ie[i + 2] & 0x7f;
1240         }
1241
1242         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1243         for (i = 0; ie && i < ie[1]; i++) {
1244                 if ((ie[i + 2] & 0x7f) > rate)
1245                         rate = ie[i + 2] & 0x7f;
1246         }
1247
1248         return rate;
1249 }
1250
1251
1252 /**
1253  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1254  * @res: Scan result entry
1255  * @ie: Information element identitifier (WLAN_EID_*)
1256  * Returns: Pointer to the information element (id field) or %NULL if not found
1257  *
1258  * This function returns the first matching information element in the scan
1259  * result.
1260  */
1261 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1262 {
1263         const u8 *end, *pos;
1264
1265         pos = (const u8 *) (res + 1);
1266         end = pos + res->ie_len;
1267
1268         while (pos + 1 < end) {
1269                 if (pos + 2 + pos[1] > end)
1270                         break;
1271                 if (pos[0] == ie)
1272                         return pos;
1273                 pos += 2 + pos[1];
1274         }
1275
1276         return NULL;
1277 }
1278
1279
1280 /**
1281  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1282  * @res: Scan result entry
1283  * @vendor_type: Vendor type (four octets starting the IE payload)
1284  * Returns: Pointer to the information element (id field) or %NULL if not found
1285  *
1286  * This function returns the first matching information element in the scan
1287  * result.
1288  */
1289 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1290                                   u32 vendor_type)
1291 {
1292         const u8 *end, *pos;
1293
1294         pos = (const u8 *) (res + 1);
1295         end = pos + res->ie_len;
1296
1297         while (pos + 1 < end) {
1298                 if (pos + 2 + pos[1] > end)
1299                         break;
1300                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1301                     vendor_type == WPA_GET_BE32(&pos[2]))
1302                         return pos;
1303                 pos += 2 + pos[1];
1304         }
1305
1306         return NULL;
1307 }
1308
1309
1310 /**
1311  * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1312  * @res: Scan result entry
1313  * @vendor_type: Vendor type (four octets starting the IE payload)
1314  * Returns: Pointer to the information element (id field) or %NULL if not found
1315  *
1316  * This function returns the first matching information element in the scan
1317  * result.
1318  *
1319  * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1320  * from Beacon frames instead of either Beacon or Probe Response frames.
1321  */
1322 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1323                                          u32 vendor_type)
1324 {
1325         const u8 *end, *pos;
1326
1327         if (res->beacon_ie_len == 0)
1328                 return NULL;
1329
1330         pos = (const u8 *) (res + 1);
1331         pos += res->ie_len;
1332         end = pos + res->beacon_ie_len;
1333
1334         while (pos + 1 < end) {
1335                 if (pos + 2 + pos[1] > end)
1336                         break;
1337                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1338                     vendor_type == WPA_GET_BE32(&pos[2]))
1339                         return pos;
1340                 pos += 2 + pos[1];
1341         }
1342
1343         return NULL;
1344 }
1345
1346
1347 /**
1348  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1349  * @res: Scan result entry
1350  * @vendor_type: Vendor type (four octets starting the IE payload)
1351  * Returns: Pointer to the information element payload or %NULL if not found
1352  *
1353  * This function returns concatenated payload of possibly fragmented vendor
1354  * specific information elements in the scan result. The caller is responsible
1355  * for freeing the returned buffer.
1356  */
1357 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1358                                              u32 vendor_type)
1359 {
1360         struct wpabuf *buf;
1361         const u8 *end, *pos;
1362
1363         buf = wpabuf_alloc(res->ie_len);
1364         if (buf == NULL)
1365                 return NULL;
1366
1367         pos = (const u8 *) (res + 1);
1368         end = pos + res->ie_len;
1369
1370         while (pos + 1 < end) {
1371                 if (pos + 2 + pos[1] > end)
1372                         break;
1373                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1374                     vendor_type == WPA_GET_BE32(&pos[2]))
1375                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1376                 pos += 2 + pos[1];
1377         }
1378
1379         if (wpabuf_len(buf) == 0) {
1380                 wpabuf_free(buf);
1381                 buf = NULL;
1382         }
1383
1384         return buf;
1385 }
1386
1387
1388 /*
1389  * Channels with a great SNR can operate at full rate. What is a great SNR?
1390  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1391  * rule of thumb is that any SNR above 20 is good." This one
1392  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1393  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1394  * conservative value.
1395  */
1396 #define GREAT_SNR 30
1397
1398 /* Compare function for sorting scan results. Return >0 if @b is considered
1399  * better. */
1400 static int wpa_scan_result_compar(const void *a, const void *b)
1401 {
1402 #define IS_5GHZ(n) (n > 4000)
1403 #define MIN(a,b) a < b ? a : b
1404         struct wpa_scan_res **_wa = (void *) a;
1405         struct wpa_scan_res **_wb = (void *) b;
1406         struct wpa_scan_res *wa = *_wa;
1407         struct wpa_scan_res *wb = *_wb;
1408         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1409         int snr_a, snr_b;
1410
1411         /* WPA/WPA2 support preferred */
1412         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1413                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1414         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1415                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1416
1417         if (wpa_b && !wpa_a)
1418                 return 1;
1419         if (!wpa_b && wpa_a)
1420                 return -1;
1421
1422         /* privacy support preferred */
1423         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1424             (wb->caps & IEEE80211_CAP_PRIVACY))
1425                 return 1;
1426         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1427             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1428                 return -1;
1429
1430         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1431             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1432                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1433                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1434         } else {
1435                 /* Not suitable information to calculate SNR, so use level */
1436                 snr_a = wa->level;
1437                 snr_b = wb->level;
1438         }
1439
1440         /* best/max rate preferred if SNR close enough */
1441         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1442             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1443                 maxrate_a = wpa_scan_get_max_rate(wa);
1444                 maxrate_b = wpa_scan_get_max_rate(wb);
1445                 if (maxrate_a != maxrate_b)
1446                         return maxrate_b - maxrate_a;
1447                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1448                         return IS_5GHZ(wa->freq) ? -1 : 1;
1449         }
1450
1451         /* use freq for channel preference */
1452
1453         /* all things being equal, use SNR; if SNRs are
1454          * identical, use quality values since some drivers may only report
1455          * that value and leave the signal level zero */
1456         if (snr_b == snr_a)
1457                 return wb->qual - wa->qual;
1458         return snr_b - snr_a;
1459 #undef MIN
1460 #undef IS_5GHZ
1461 }
1462
1463
1464 #ifdef CONFIG_WPS
1465 /* Compare function for sorting scan results when searching a WPS AP for
1466  * provisioning. Return >0 if @b is considered better. */
1467 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1468 {
1469         struct wpa_scan_res **_wa = (void *) a;
1470         struct wpa_scan_res **_wb = (void *) b;
1471         struct wpa_scan_res *wa = *_wa;
1472         struct wpa_scan_res *wb = *_wb;
1473         int uses_wps_a, uses_wps_b;
1474         struct wpabuf *wps_a, *wps_b;
1475         int res;
1476
1477         /* Optimization - check WPS IE existence before allocated memory and
1478          * doing full reassembly. */
1479         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1480         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1481         if (uses_wps_a && !uses_wps_b)
1482                 return -1;
1483         if (!uses_wps_a && uses_wps_b)
1484                 return 1;
1485
1486         if (uses_wps_a && uses_wps_b) {
1487                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1488                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1489                 res = wps_ap_priority_compar(wps_a, wps_b);
1490                 wpabuf_free(wps_a);
1491                 wpabuf_free(wps_b);
1492                 if (res)
1493                         return res;
1494         }
1495
1496         /*
1497          * Do not use current AP security policy as a sorting criteria during
1498          * WPS provisioning step since the AP may get reconfigured at the
1499          * completion of provisioning.
1500          */
1501
1502         /* all things being equal, use signal level; if signal levels are
1503          * identical, use quality values since some drivers may only report
1504          * that value and leave the signal level zero */
1505         if (wb->level == wa->level)
1506                 return wb->qual - wa->qual;
1507         return wb->level - wa->level;
1508 }
1509 #endif /* CONFIG_WPS */
1510
1511
1512 static void dump_scan_res(struct wpa_scan_results *scan_res)
1513 {
1514 #ifndef CONFIG_NO_STDOUT_DEBUG
1515         size_t i;
1516
1517         if (scan_res->res == NULL || scan_res->num == 0)
1518                 return;
1519
1520         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1521
1522         for (i = 0; i < scan_res->num; i++) {
1523                 struct wpa_scan_res *r = scan_res->res[i];
1524                 u8 *pos;
1525                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1526                     == WPA_SCAN_LEVEL_DBM) {
1527                         int snr = r->level - r->noise;
1528                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1529                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1530                                    "age=%u",
1531                                    MAC2STR(r->bssid), r->freq, r->qual,
1532                                    r->noise, r->level, snr,
1533                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1534                                    r->age);
1535                 } else {
1536                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1537                                    "noise=%d level=%d flags=0x%x age=%u",
1538                                    MAC2STR(r->bssid), r->freq, r->qual,
1539                                    r->noise, r->level, r->flags, r->age);
1540                 }
1541                 pos = (u8 *) (r + 1);
1542                 if (r->ie_len)
1543                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1544                 pos += r->ie_len;
1545                 if (r->beacon_ie_len)
1546                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1547                                     pos, r->beacon_ie_len);
1548         }
1549 #endif /* CONFIG_NO_STDOUT_DEBUG */
1550 }
1551
1552
1553 /**
1554  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1555  * @wpa_s: Pointer to wpa_supplicant data
1556  * @bssid: BSSID to check
1557  * Returns: 0 if the BSSID is filtered or 1 if not
1558  *
1559  * This function is used to filter out specific BSSIDs from scan reslts mainly
1560  * for testing purposes (SET bssid_filter ctrl_iface command).
1561  */
1562 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1563                                       const u8 *bssid)
1564 {
1565         size_t i;
1566
1567         if (wpa_s->bssid_filter == NULL)
1568                 return 1;
1569
1570         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1571                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1572                               ETH_ALEN) == 0)
1573                         return 1;
1574         }
1575
1576         return 0;
1577 }
1578
1579
1580 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1581                             struct wpa_scan_results *res)
1582 {
1583         size_t i, j;
1584
1585         if (wpa_s->bssid_filter == NULL)
1586                 return;
1587
1588         for (i = 0, j = 0; i < res->num; i++) {
1589                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1590                                                       res->res[i]->bssid)) {
1591                         res->res[j++] = res->res[i];
1592                 } else {
1593                         os_free(res->res[i]);
1594                         res->res[i] = NULL;
1595                 }
1596         }
1597
1598         if (res->num != j) {
1599                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1600                            (int) (res->num - j));
1601                 res->num = j;
1602         }
1603 }
1604
1605
1606 /**
1607  * wpa_supplicant_get_scan_results - Get scan results
1608  * @wpa_s: Pointer to wpa_supplicant data
1609  * @info: Information about what was scanned or %NULL if not available
1610  * @new_scan: Whether a new scan was performed
1611  * Returns: Scan results, %NULL on failure
1612  *
1613  * This function request the current scan results from the driver and updates
1614  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1615  * results with wpa_scan_results_free().
1616  */
1617 struct wpa_scan_results *
1618 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1619                                 struct scan_info *info, int new_scan)
1620 {
1621         struct wpa_scan_results *scan_res;
1622         size_t i;
1623         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1624
1625         scan_res = wpa_drv_get_scan_results2(wpa_s);
1626         if (scan_res == NULL) {
1627                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1628                 return NULL;
1629         }
1630         if (scan_res->fetch_time.sec == 0) {
1631                 /*
1632                  * Make sure we have a valid timestamp if the driver wrapper
1633                  * does not set this.
1634                  */
1635                 os_get_reltime(&scan_res->fetch_time);
1636         }
1637         filter_scan_res(wpa_s, scan_res);
1638
1639 #ifdef CONFIG_WPS
1640         if (wpas_wps_searching(wpa_s)) {
1641                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1642                         "provisioning rules");
1643                 compar = wpa_scan_result_wps_compar;
1644         }
1645 #endif /* CONFIG_WPS */
1646
1647         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1648               compar);
1649         dump_scan_res(scan_res);
1650
1651         wpa_bss_update_start(wpa_s);
1652         for (i = 0; i < scan_res->num; i++)
1653                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1654                                         &scan_res->fetch_time);
1655         wpa_bss_update_end(wpa_s, info, new_scan);
1656
1657         return scan_res;
1658 }
1659
1660
1661 /**
1662  * wpa_supplicant_update_scan_results - Update scan results from the driver
1663  * @wpa_s: Pointer to wpa_supplicant data
1664  * Returns: 0 on success, -1 on failure
1665  *
1666  * This function updates the BSS table within wpa_supplicant based on the
1667  * currently available scan results from the driver without requesting a new
1668  * scan. This is used in cases where the driver indicates an association
1669  * (including roaming within ESS) and wpa_supplicant does not yet have the
1670  * needed information to complete the connection (e.g., to perform validation
1671  * steps in 4-way handshake).
1672  */
1673 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1674 {
1675         struct wpa_scan_results *scan_res;
1676         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1677         if (scan_res == NULL)
1678                 return -1;
1679         wpa_scan_results_free(scan_res);
1680
1681         return 0;
1682 }
1683
1684
1685 /**
1686  * scan_only_handler - Reports scan results
1687  */
1688 void scan_only_handler(struct wpa_supplicant *wpa_s,
1689                        struct wpa_scan_results *scan_res)
1690 {
1691         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1692         if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
1693             wpa_s->manual_scan_use_id && wpa_s->own_scan_running) {
1694                 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS "id=%u",
1695                              wpa_s->manual_scan_id);
1696                 wpa_s->manual_scan_use_id = 0;
1697         } else {
1698                 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1699         }
1700         wpas_notify_scan_results(wpa_s);
1701         wpas_notify_scan_done(wpa_s, 1);
1702 }
1703
1704
1705 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1706 {
1707         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1708 }