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 static int int_array_len(const int *a)
 146 {
 147         int i;
 148         for (i = 0; a && a[i]; i++)
 149                 ;
 150         return i;
 151 }
 152
 153
 154 static void int_array_concat(int **res, const int *a)
 155 {
 156         int reslen, alen, i;
 157         int *n;
 158
 159         reslen = int_array_len(*res);
 160         alen = int_array_len(a);
 161
 162         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 163         if (n == NULL) {
 164                 os_free(*res);
 165                 *res = NULL;
 166                 return;
 167         }
 168         for (i = 0; i <= alen; i++)
 169                 n[reslen + i] = a[i];
 170         *res = n;
 171 }
 172
 173
 174 static int freq_cmp(const void *a, const void *b)
 175 {
 176         int _a = *(int *) a;
 177         int _b = *(int *) b;
 178
 179         if (_a == 0)
 180                 return 1;
 181         if (_b == 0)
 182                 return -1;
 183         return _a - _b;
 184 }
 185
 186
 187 static void int_array_sort_unique(int *a)
 188 {
 189         int alen;
 190         int i, j;
 191
 192         if (a == NULL)
 193                 return;
 194
 195         alen = int_array_len(a);
 196         qsort(a, alen, sizeof(int), freq_cmp);
 197
 198         i = 0;
 199         j = 1;
 200         while (a[i] && a[j]) {
 201                 if (a[i] == a[j]) {
 202                         j++;
 203                         continue;
 204                 }
 205                 a[++i] = a[j++];
 206         }
 207         if (a[i])
 208                 i++;
 209         a[i] = 0;
 210 }
 211
 212
 213 /**
 214  * wpa_supplicant_trigger_scan - Request driver to start a scan
 215  * @wpa_s: Pointer to wpa_supplicant data
 216  * @params: Scan parameters
 217  * Returns: 0 on success, -1 on failure
 218  */
 219 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 220                                 struct wpa_driver_scan_params *params)
 221 {
 222         int ret;
 223
 224         wpa_supplicant_notify_scanning(wpa_s, 1);
 225
 226         ret = wpa_drv_scan(wpa_s, params);
 227         if (ret) {
 228                 wpa_supplicant_notify_scanning(wpa_s, 0);
 229                 wpas_notify_scan_done(wpa_s, 0);
 230         } else {
 231                 os_get_time(&wpa_s->scan_trigger_time);
 232                 wpa_s->scan_runs++;
 233                 wpa_s->normal_scans++;
 234         }
 235
 236         return ret;
 237 }
 238
 239
 240 static void
 241 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 242 {
 243         struct wpa_supplicant *wpa_s = eloop_ctx;
 244
 245         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 246
 247         if (wpa_supplicant_req_sched_scan(wpa_s))
 248                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 249 }
 250
 251
 252 static void
 253 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 254 {
 255         struct wpa_supplicant *wpa_s = eloop_ctx;
 256
 257         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 258
 259         wpa_s->sched_scan_timed_out = 1;
 260         wpa_supplicant_cancel_sched_scan(wpa_s);
 261 }
 262
 263
 264 int wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 265                                     struct wpa_driver_scan_params *params,
 266                                     int interval)
 267 {
 268         int ret;
 269
 270         wpa_supplicant_notify_scanning(wpa_s, 1);
 271         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 272         if (ret)
 273                 wpa_supplicant_notify_scanning(wpa_s, 0);
 274         else
 275                 wpa_s->sched_scanning = 1;
 276
 277         return ret;
 278 }
 279
 280
 281 int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 282 {
 283         int ret;
 284
 285         ret = wpa_drv_stop_sched_scan(wpa_s);
 286         if (ret) {
 287                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 288                 /* TODO: what to do if stopping fails? */
 289                 return -1;
 290         }
 291
 292         return ret;
 293 }
 294
 295
 296 static struct wpa_driver_scan_filter *
 297 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 298 {
 299         struct wpa_driver_scan_filter *ssids;
 300         struct wpa_ssid *ssid;
 301         size_t count;
 302
 303         *num_ssids = 0;
 304         if (!conf->filter_ssids)
 305                 return NULL;
 306
 307         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 308                 if (ssid->ssid && ssid->ssid_len)
 309                         count++;
 310         }
 311         if (count == 0)
 312                 return NULL;
 313         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 314         if (ssids == NULL)
 315                 return NULL;
 316
 317         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 318                 if (!ssid->ssid || !ssid->ssid_len)
 319                         continue;
 320                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 321                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 322                 (*num_ssids)++;
 323         }
 324
 325         return ssids;
 326 }
 327
 328
 329 static void wpa_supplicant_optimize_freqs(
 330         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 331 {
 332 #ifdef CONFIG_P2P
 333         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 334             wpa_s->go_params) {
 335                 /* Optimize provisioning state scan based on GO information */
 336                 if (wpa_s->p2p_in_provisioning < 5 &&
 337                     wpa_s->go_params->freq > 0) {
 338                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 339                                 "preferred frequency %d MHz",
 340                                 wpa_s->go_params->freq);
 341                         params->freqs = os_zalloc(2 * sizeof(int));
 342                         if (params->freqs)
 343                                 params->freqs[0] = wpa_s->go_params->freq;
 344                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 345                            wpa_s->go_params->freq_list[0]) {
 346                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 347                                 "channels");
 348                         int_array_concat(&params->freqs,
 349                                          wpa_s->go_params->freq_list);
 350                         if (params->freqs)
 351                                 int_array_sort_unique(params->freqs);
 352                 }
 353                 wpa_s->p2p_in_provisioning++;
 354         }
 355 #endif /* CONFIG_P2P */
 356
 357 #ifdef CONFIG_WPS
 358         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 359                 /*
 360                  * Optimize post-provisioning scan based on channel used
 361                  * during provisioning.
 362                  */
 363                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 364                         "that was used during provisioning", wpa_s->wps_freq);
 365                 params->freqs = os_zalloc(2 * sizeof(int));
 366                 if (params->freqs)
 367                         params->freqs[0] = wpa_s->wps_freq;
 368                 wpa_s->after_wps--;
 369         }
 370
 371         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 372         {
 373                 /* Optimize provisioning scan based on already known channel */
 374                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 375                         wpa_s->wps_freq);
 376                 params->freqs = os_zalloc(2 * sizeof(int));
 377                 if (params->freqs)
 378                         params->freqs[0] = wpa_s->wps_freq;
 379                 wpa_s->known_wps_freq = 0; /* only do this once */
 380         }
 381 #endif /* CONFIG_WPS */
 382 }
 383
 384
 385 #ifdef CONFIG_INTERWORKING
 386 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 387                                            struct wpabuf *buf)
 388 {
 389         if (wpa_s->conf->interworking == 0)
 390                 return;
 391
 392         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 393         wpabuf_put_u8(buf, 4);
 394         wpabuf_put_u8(buf, 0x00);
 395         wpabuf_put_u8(buf, 0x00);
 396         wpabuf_put_u8(buf, 0x00);
 397         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 398
 399         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 400         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 401                       1 + ETH_ALEN);
 402         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 403         /* No Venue Info */
 404         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 405                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 406 }
 407 #endif /* CONFIG_INTERWORKING */
 408
 409
 410 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 411 {
 412         struct wpabuf *extra_ie = NULL;
 413 #ifdef CONFIG_WPS
 414         int wps = 0;
 415         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 416 #endif /* CONFIG_WPS */
 417
 418 #ifdef CONFIG_INTERWORKING
 419         if (wpa_s->conf->interworking &&
 420             wpabuf_resize(&extra_ie, 100) == 0)
 421                 wpas_add_interworking_elements(wpa_s, extra_ie);
 422 #endif /* CONFIG_INTERWORKING */
 423
 424 #ifdef CONFIG_WPS
 425         wps = wpas_wps_in_use(wpa_s, &req_type);
 426
 427         if (wps) {
 428                 struct wpabuf *wps_ie;
 429                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 430                                                 DEV_PW_DEFAULT,
 431                                                 &wpa_s->wps->dev,
 432                                                 wpa_s->wps->uuid, req_type,
 433                                                 0, NULL);
 434                 if (wps_ie) {
 435                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 436                                 wpabuf_put_buf(extra_ie, wps_ie);
 437                         wpabuf_free(wps_ie);
 438                 }
 439         }
 440
 441 #ifdef CONFIG_P2P
 442         if (wps) {
 443                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 444                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 445                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 446         }
 447 #endif /* CONFIG_P2P */
 448
 449 #endif /* CONFIG_WPS */
 450
 451 #ifdef CONFIG_HS20
 452         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 453                 wpas_hs20_add_indication(extra_ie);
 454 #endif /* CONFIG_HS20 */
 455
 456         return extra_ie;
 457 }
 458
 459
 460 #ifdef CONFIG_P2P
 461
 462 /*
 463  * Check whether there are any enabled networks or credentials that could be
 464  * used for a non-P2P connection.
 465  */
 466 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 467 {
 468         struct wpa_ssid *ssid;
 469
 470         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 471                 if (wpas_network_disabled(wpa_s, ssid))
 472                         continue;
 473                 if (!ssid->p2p_group)
 474                         return 1;
 475         }
 476
 477         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 478             wpa_s->conf->auto_interworking)
 479                 return 1;
 480
 481         return 0;
 482 }
 483
 484 #endif /* CONFIG_P2P */
 485
 486
 487 static struct hostapd_hw_modes * get_mode(struct hostapd_hw_modes *modes,
 488                                           u16 num_modes,
 489                                           enum hostapd_hw_mode mode)
 490 {
 491         u16 i;
 492
 493         for (i = 0; i < num_modes; i++) {
 494                 if (modes[i].mode == mode)
 495                         return &modes[i];
 496         }
 497
 498         return NULL;
 499 }
 500
 501
 502 static void wpa_setband_scan_freqs_list(struct wpa_supplicant *wpa_s,
 503                                         enum hostapd_hw_mode band,
 504                                         struct wpa_driver_scan_params *params)
 505 {
 506         /* Include only supported channels for the specified band */
 507         struct hostapd_hw_modes *mode;
 508         int count, i;
 509
 510         mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, band);
 511         if (mode == NULL) {
 512                 /* No channels supported in this band - use empty list */
 513                 params->freqs = os_zalloc(sizeof(int));
 514                 return;
 515         }
 516
 517         params->freqs = os_zalloc((mode->num_channels + 1) * sizeof(int));
 518         if (params->freqs == NULL)
 519                 return;
 520         for (count = 0, i = 0; i < mode->num_channels; i++) {
 521                 if (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED)
 522                         continue;
 523                 params->freqs[count++] = mode->channels[i].freq;
 524         }
 525 }
 526
 527
 528 static void wpa_setband_scan_freqs(struct wpa_supplicant *wpa_s,
 529                                    struct wpa_driver_scan_params *params)
 530 {
 531         if (wpa_s->hw.modes == NULL)
 532                 return; /* unknown what channels the driver supports */
 533         if (params->freqs)
 534                 return; /* already using a limited channel set */
 535         if (wpa_s->setband == WPA_SETBAND_5G)
 536                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211A,
 537                                             params);
 538         else if (wpa_s->setband == WPA_SETBAND_2G)
 539                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211G,
 540                                             params);
 541 }
 542
 543
 544 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 545 {
 546         struct wpa_supplicant *wpa_s = eloop_ctx;
 547         struct wpa_ssid *ssid;
 548         int ret;
 549         struct wpabuf *extra_ie = NULL;
 550         struct wpa_driver_scan_params params;
 551         struct wpa_driver_scan_params *scan_params;
 552         size_t max_ssids;
 553         enum wpa_states prev_state;
 554
 555         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 556                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 557                 wpas_p2p_continue_after_scan(wpa_s);
 558                 return;
 559         }
 560
 561         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 562                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 563                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 564                 wpas_p2p_continue_after_scan(wpa_s);
 565                 return;
 566         }
 567
 568         if (wpa_s->scanning) {
 569                 /*
 570                  * If we are already in scanning state, we shall reschedule the
 571                  * the incoming scan request.
 572                  */
 573                 wpa_dbg(wpa_s, MSG_DEBUG, "Already scanning - Reschedule the incoming scan req");
 574                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 575                 return;
 576         }
 577
 578         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 579             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 580                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 581                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 582                 wpas_p2p_continue_after_scan(wpa_s);
 583                 return;
 584         }
 585
 586         if (wpa_s->conf->ap_scan != 0 &&
 587             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 588                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 589                         "overriding ap_scan configuration");
 590                 wpa_s->conf->ap_scan = 0;
 591                 wpas_notify_ap_scan_changed(wpa_s);
 592         }
 593
 594         if (wpa_s->conf->ap_scan == 0) {
 595                 wpa_supplicant_gen_assoc_event(wpa_s);
 596                 return;
 597         }
 598
 599 #ifdef CONFIG_P2P
 600         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
 601                 if (wpa_s->sta_scan_pending &&
 602                     wpas_p2p_in_progress(wpa_s) == 2 &&
 603                     wpa_s->global->p2p_cb_on_scan_complete) {
 604                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 605                                 "mode scan during P2P search");
 606                 } else {
 607                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 608                                 "while P2P operation is in progress");
 609                         wpa_s->sta_scan_pending = 1;
 610                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 611                         return;
 612                 }
 613         }
 614 #endif /* CONFIG_P2P */
 615
 616 #ifdef CONFIG_GAS
 617         if (gas_query_in_progress(wpa_s->gas)) {
 618                 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
 619                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 620                 return;
 621         }
 622 #endif /* CONFIG_GAS */
 623
 624         if (wpa_s->conf->ap_scan == 2)
 625                 max_ssids = 1;
 626         else {
 627                 max_ssids = wpa_s->max_scan_ssids;
 628                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 629                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 630         }
 631
 632         wpa_s->last_scan_req = wpa_s->scan_req;
 633         wpa_s->scan_req = NORMAL_SCAN_REQ;
 634
 635         os_memset(&params, 0, sizeof(params));
 636
 637         prev_state = wpa_s->wpa_state;
 638         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 639             wpa_s->wpa_state == WPA_INACTIVE)
 640                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 641
 642         /*
 643          * If autoscan has set its own scanning parameters
 644          */
 645         if (wpa_s->autoscan_params != NULL) {
 646                 scan_params = wpa_s->autoscan_params;
 647                 goto scan;
 648         }
 649
 650         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 651             wpa_s->connect_without_scan) {
 652                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 653                         if (ssid == wpa_s->connect_without_scan)
 654                                 break;
 655                 }
 656                 wpa_s->connect_without_scan = NULL;
 657                 if (ssid) {
 658                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 659                                    "without scan step");
 660                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 661                         return;
 662                 }
 663         }
 664
 665 #ifdef CONFIG_P2P
 666         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 667             wpa_s->go_params) {
 668                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during P2P group formation (p2p_in_provisioning=%d show_group_started=%d)",
 669                            wpa_s->p2p_in_provisioning,
 670                            wpa_s->show_group_started);
 671                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 672                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 673                 params.num_ssids = 1;
 674                 goto ssid_list_set;
 675         }
 676 #endif /* CONFIG_P2P */
 677
 678         /* Find the starting point from which to continue scanning */
 679         ssid = wpa_s->conf->ssid;
 680         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 681                 while (ssid) {
 682                         if (ssid == wpa_s->prev_scan_ssid) {
 683                                 ssid = ssid->next;
 684                                 break;
 685                         }
 686                         ssid = ssid->next;
 687                 }
 688         }
 689
 690         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 691             wpa_s->conf->ap_scan == 2) {
 692                 wpa_s->connect_without_scan = NULL;
 693                 wpa_s->prev_scan_wildcard = 0;
 694                 wpa_supplicant_assoc_try(wpa_s, ssid);
 695                 return;
 696         } else if (wpa_s->conf->ap_scan == 2) {
 697                 /*
 698                  * User-initiated scan request in ap_scan == 2; scan with
 699                  * wildcard SSID.
 700                  */
 701                 ssid = NULL;
 702         } else {
 703                 struct wpa_ssid *start = ssid, *tssid;
 704                 int freqs_set = 0;
 705                 if (ssid == NULL && max_ssids > 1)
 706                         ssid = wpa_s->conf->ssid;
 707                 while (ssid) {
 708                         if (!wpas_network_disabled(wpa_s, ssid) &&
 709                             ssid->scan_ssid) {
 710                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 711                                                   ssid->ssid, ssid->ssid_len);
 712                                 params.ssids[params.num_ssids].ssid =
 713                                         ssid->ssid;
 714                                 params.ssids[params.num_ssids].ssid_len =
 715                                         ssid->ssid_len;
 716                                 params.num_ssids++;
 717                                 if (params.num_ssids + 1 >= max_ssids)
 718                                         break;
 719                         }
 720                         ssid = ssid->next;
 721                         if (ssid == start)
 722                                 break;
 723                         if (ssid == NULL && max_ssids > 1 &&
 724                             start != wpa_s->conf->ssid)
 725                                 ssid = wpa_s->conf->ssid;
 726                 }
 727
 728                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 729                         if (wpas_network_disabled(wpa_s, tssid))
 730                                 continue;
 731                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 732                                 int_array_concat(&params.freqs,
 733                                                  tssid->scan_freq);
 734                         } else {
 735                                 os_free(params.freqs);
 736                                 params.freqs = NULL;
 737                         }
 738                         freqs_set = 1;
 739                 }
 740                 int_array_sort_unique(params.freqs);
 741         }
 742
 743         if (ssid && max_ssids == 1) {
 744                 /*
 745                  * If the driver is limited to 1 SSID at a time interleave
 746                  * wildcard SSID scans with specific SSID scans to avoid
 747                  * waiting a long time for a wildcard scan.
 748                  */
 749                 if (!wpa_s->prev_scan_wildcard) {
 750                         params.ssids[0].ssid = NULL;
 751                         params.ssids[0].ssid_len = 0;
 752                         wpa_s->prev_scan_wildcard = 1;
 753                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 754                                 "wildcard SSID (Interleave with specific)");
 755                 } else {
 756                         wpa_s->prev_scan_ssid = ssid;
 757                         wpa_s->prev_scan_wildcard = 0;
 758                         wpa_dbg(wpa_s, MSG_DEBUG,
 759                                 "Starting AP scan for specific SSID: %s",
 760                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 761                 }
 762         } else if (ssid) {
 763                 /* max_ssids > 1 */
 764
 765                 wpa_s->prev_scan_ssid = ssid;
 766                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 767                         "the scan request");
 768                 params.num_ssids++;
 769         } else {
 770                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 771                 params.num_ssids++;
 772                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 773                         "SSID");
 774         }
 775 #ifdef CONFIG_P2P
 776 ssid_list_set:
 777 #endif /* CONFIG_P2P */
 778
 779         wpa_supplicant_optimize_freqs(wpa_s, &params);
 780         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 781
 782         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 783                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 784                         "generated frequency list");
 785                 params.freqs = wpa_s->next_scan_freqs;
 786         } else
 787                 os_free(wpa_s->next_scan_freqs);
 788         wpa_s->next_scan_freqs = NULL;
 789         wpa_setband_scan_freqs(wpa_s, &params);
 790
 791         /* See if user specified frequencies. If so, scan only those. */
 792         if (wpa_s->conf->freq_list && !params.freqs) {
 793                 wpa_dbg(wpa_s, MSG_DEBUG,
 794                         "Optimize scan based on conf->freq_list");
 795                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 796         }
 797
 798         /* Use current associated channel? */
 799         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 800                 unsigned int num = wpa_s->num_multichan_concurrent;
 801
 802                 params.freqs = os_calloc(num + 1, sizeof(int));
 803                 if (params.freqs) {
 804                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 805                         if (num > 0) {
 806                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
 807                                         "current operating channels since "
 808                                         "scan_cur_freq is enabled");
 809                         } else {
 810                                 os_free(params.freqs);
 811                                 params.freqs = NULL;
 812                         }
 813                 }
 814         }
 815
 816         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 817                 wpa_s->conf, &params.num_filter_ssids);
 818         if (extra_ie) {
 819                 params.extra_ies = wpabuf_head(extra_ie);
 820                 params.extra_ies_len = wpabuf_len(extra_ie);
 821         }
 822
 823 #ifdef CONFIG_P2P
 824         if (wpa_s->p2p_in_provisioning ||
 825             (wpa_s->show_group_started && wpa_s->go_params)) {
 826                 /*
 827                  * The interface may not yet be in P2P mode, so we have to
 828                  * explicitly request P2P probe to disable CCK rates.
 829                  */
 830                 params.p2p_probe = 1;
 831         }
 832 #endif /* CONFIG_P2P */
 833
 834         scan_params = &params;
 835
 836 scan:
 837 #ifdef CONFIG_P2P
 838         /*
 839          * If the driver does not support multi-channel concurrency and a
 840          * virtual interface that shares the same radio with the wpa_s interface
 841          * is operating there may not be need to scan other channels apart from
 842          * the current operating channel on the other virtual interface. Filter
 843          * out other channels in case we are trying to find a connection for a
 844          * station interface when we are not configured to prefer station
 845          * connection and a concurrent operation is already in process.
 846          */
 847         if (wpa_s->scan_for_connection &&
 848             wpa_s->last_scan_req == NORMAL_SCAN_REQ &&
 849             !scan_params->freqs && !params.freqs &&
 850             wpas_is_p2p_prioritized(wpa_s) &&
 851             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 852             non_p2p_network_enabled(wpa_s)) {
 853                 unsigned int num = wpa_s->num_multichan_concurrent;
 854
 855                 params.freqs = os_calloc(num + 1, sizeof(int));
 856                 if (params.freqs) {
 857                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 858                         if (num > 0 && num == wpa_s->num_multichan_concurrent) {
 859                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
 860                         } else {
 861                                 os_free(params.freqs);
 862                                 params.freqs = NULL;
 863                         }
 864                 }
 865         }
 866 #endif /* CONFIG_P2P */
 867
 868         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 869
 870         wpabuf_free(extra_ie);
 871         os_free(params.freqs);
 872         os_free(params.filter_ssids);
 873
 874         if (ret) {
 875                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 876                 if (prev_state != wpa_s->wpa_state)
 877                         wpa_supplicant_set_state(wpa_s, prev_state);
 878                 /* Restore scan_req since we will try to scan again */
 879                 wpa_s->scan_req = wpa_s->last_scan_req;
 880                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 881         } else {
 882                 wpa_s->scan_for_connection = 0;
 883         }
 884 }
 885
 886
 887 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 888 {
 889         struct os_reltime remaining, new_int;
 890         int cancelled;
 891
 892         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 893                                              &remaining);
 894
 895         new_int.sec = sec;
 896         new_int.usec = 0;
 897         if (cancelled && os_reltime_before(&remaining, &new_int)) {
 898                 new_int.sec = remaining.sec;
 899                 new_int.usec = remaining.usec;
 900         }
 901
 902         if (cancelled) {
 903                 eloop_register_timeout(new_int.sec, new_int.usec,
 904                                        wpa_supplicant_scan, wpa_s, NULL);
 905         }
 906         wpa_s->scan_interval = sec;
 907 }
 908
 909
 910 /**
 911  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 912  * @wpa_s: Pointer to wpa_supplicant data
 913  * @sec: Number of seconds after which to scan
 914  * @usec: Number of microseconds after which to scan
 915  *
 916  * This function is used to schedule a scan for neighboring access points after
 917  * the specified time.
 918  */
 919 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 920 {
 921         if (eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL))
 922         {
 923                 wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d sec %d usec",
 924                         sec, usec);
 925                 return;
 926         }
 927
 928         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 929                 sec, usec);
 930         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 931         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 932 }
 933
 934
 935 /**
 936  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 937  * @wpa_s: Pointer to wpa_supplicant data
 938  * @sec: Number of seconds after which to scan
 939  * @usec: Number of microseconds after which to scan
 940  * Returns: 0 on success or -1 otherwise
 941  *
 942  * This function is used to schedule periodic scans for neighboring
 943  * access points after the specified time.
 944  */
 945 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 946                                       int sec, int usec)
 947 {
 948         if (!wpa_s->sched_scan_supported)
 949                 return -1;
 950
 951         eloop_register_timeout(sec, usec,
 952                                wpa_supplicant_delayed_sched_scan_timeout,
 953                                wpa_s, NULL);
 954
 955         return 0;
 956 }
 957
 958
 959 /**
 960  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 961  * @wpa_s: Pointer to wpa_supplicant data
 962  * Returns: 0 is sched_scan was started or -1 otherwise
 963  *
 964  * This function is used to schedule periodic scans for neighboring
 965  * access points repeating the scan continuously.
 966  */
 967 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 968 {
 969         struct wpa_driver_scan_params params;
 970         struct wpa_driver_scan_params *scan_params;
 971         enum wpa_states prev_state;
 972         struct wpa_ssid *ssid = NULL;
 973         struct wpabuf *extra_ie = NULL;
 974         int ret;
 975         unsigned int max_sched_scan_ssids;
 976         int wildcard = 0;
 977         int need_ssids;
 978
 979         if (!wpa_s->sched_scan_supported)
 980                 return -1;
 981
 982         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 983                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 984         else
 985                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 986         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 987                 return -1;
 988
 989         if (wpa_s->sched_scanning) {
 990                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 991                 return 0;
 992         }
 993
 994         need_ssids = 0;
 995         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 996                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 997                         /* Use wildcard SSID to find this network */
 998                         wildcard = 1;
 999                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
1000                            ssid->ssid_len)
1001                         need_ssids++;
1002
1003 #ifdef CONFIG_WPS
1004                 if (!wpas_network_disabled(wpa_s, ssid) &&
1005                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
1006                         /*
1007                          * Normal scan is more reliable and faster for WPS
1008                          * operations and since these are for short periods of
1009                          * time, the benefit of trying to use sched_scan would
1010                          * be limited.
1011                          */
1012                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1013                                 "sched_scan for WPS");
1014                         return -1;
1015                 }
1016 #endif /* CONFIG_WPS */
1017         }
1018         if (wildcard)
1019                 need_ssids++;
1020
1021         if (wpa_s->normal_scans < 3 &&
1022             (need_ssids <= wpa_s->max_scan_ssids ||
1023              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
1024                 /*
1025                  * When normal scan can speed up operations, use that for the
1026                  * first operations before starting the sched_scan to allow
1027                  * user space sleep more. We do this only if the normal scan
1028                  * has functionality that is suitable for this or if the
1029                  * sched_scan does not have better support for multiple SSIDs.
1030                  */
1031                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1032                         "sched_scan for initial scans (normal_scans=%d)",
1033                         wpa_s->normal_scans);
1034                 return -1;
1035         }
1036
1037         os_memset(&params, 0, sizeof(params));
1038
1039         /* If we can't allocate space for the filters, we just don't filter */
1040         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1041                                         sizeof(struct wpa_driver_scan_filter));
1042
1043         prev_state = wpa_s->wpa_state;
1044         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1045             wpa_s->wpa_state == WPA_INACTIVE)
1046                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1047
1048         if (wpa_s->autoscan_params != NULL) {
1049                 scan_params = wpa_s->autoscan_params;
1050                 goto scan;
1051         }
1052
1053         /* Find the starting point from which to continue scanning */
1054         ssid = wpa_s->conf->ssid;
1055         if (wpa_s->prev_sched_ssid) {
1056                 while (ssid) {
1057                         if (ssid == wpa_s->prev_sched_ssid) {
1058                                 ssid = ssid->next;
1059                                 break;
1060                         }
1061                         ssid = ssid->next;
1062                 }
1063         }
1064
1065         if (!ssid || !wpa_s->prev_sched_ssid) {
1066                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1067                 if (wpa_s->conf->sched_scan_interval)
1068                         wpa_s->sched_scan_interval =
1069                                 wpa_s->conf->sched_scan_interval;
1070                 if (wpa_s->sched_scan_interval == 0)
1071                         wpa_s->sched_scan_interval = 10;
1072                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1073                 wpa_s->first_sched_scan = 1;
1074                 ssid = wpa_s->conf->ssid;
1075                 wpa_s->prev_sched_ssid = ssid;
1076         }
1077
1078         if (wildcard) {
1079                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1080                 params.num_ssids++;
1081         }
1082
1083         while (ssid) {
1084                 if (wpas_network_disabled(wpa_s, ssid))
1085                         goto next;
1086
1087                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1088                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1089                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1090                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1091                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1092                                   ssid->ssid, ssid->ssid_len);
1093                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1094                                 ssid->ssid_len;
1095                         params.num_filter_ssids++;
1096                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1097                 {
1098                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1099                                 "filter for sched_scan - drop filter");
1100                         os_free(params.filter_ssids);
1101                         params.filter_ssids = NULL;
1102                         params.num_filter_ssids = 0;
1103                 }
1104
1105                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1106                         if (params.num_ssids == max_sched_scan_ssids)
1107                                 break; /* only room for broadcast SSID */
1108                         wpa_dbg(wpa_s, MSG_DEBUG,
1109                                 "add to active scan ssid: %s",
1110                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1111                         params.ssids[params.num_ssids].ssid =
1112                                 ssid->ssid;
1113                         params.ssids[params.num_ssids].ssid_len =
1114                                 ssid->ssid_len;
1115                         params.num_ssids++;
1116                         if (params.num_ssids >= max_sched_scan_ssids) {
1117                                 wpa_s->prev_sched_ssid = ssid;
1118                                 do {
1119                                         ssid = ssid->next;
1120                                 } while (ssid &&
1121                                          (wpas_network_disabled(wpa_s, ssid) ||
1122                                           !ssid->scan_ssid));
1123                                 break;
1124                         }
1125                 }
1126
1127         next:
1128                 wpa_s->prev_sched_ssid = ssid;
1129                 ssid = ssid->next;
1130         }
1131
1132         if (params.num_filter_ssids == 0) {
1133                 os_free(params.filter_ssids);
1134                 params.filter_ssids = NULL;
1135         }
1136
1137         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1138         if (extra_ie) {
1139                 params.extra_ies = wpabuf_head(extra_ie);
1140                 params.extra_ies_len = wpabuf_len(extra_ie);
1141         }
1142
1143         scan_params = &params;
1144
1145 scan:
1146         if (ssid || !wpa_s->first_sched_scan) {
1147                 wpa_dbg(wpa_s, MSG_DEBUG,
1148                         "Starting sched scan: interval %d timeout %d",
1149                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1150         } else {
1151                 wpa_dbg(wpa_s, MSG_DEBUG,
1152                         "Starting sched scan: interval %d (no timeout)",
1153                         wpa_s->sched_scan_interval);
1154         }
1155
1156         wpa_setband_scan_freqs(wpa_s, scan_params);
1157
1158         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1159                                               wpa_s->sched_scan_interval);
1160         wpabuf_free(extra_ie);
1161         os_free(params.filter_ssids);
1162         if (ret) {
1163                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1164                 if (prev_state != wpa_s->wpa_state)
1165                         wpa_supplicant_set_state(wpa_s, prev_state);
1166                 return ret;
1167         }
1168
1169         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1170         if (ssid || !wpa_s->first_sched_scan) {
1171                 wpa_s->sched_scan_timed_out = 0;
1172                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1173                                        wpa_supplicant_sched_scan_timeout,
1174                                        wpa_s, NULL);
1175                 wpa_s->first_sched_scan = 0;
1176                 wpa_s->sched_scan_timeout /= 2;
1177                 wpa_s->sched_scan_interval *= 2;
1178                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1179                         wpa_s->sched_scan_interval = 10;
1180                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1181                 }
1182         }
1183
1184         /* If there is no more ssids, start next time from the beginning */
1185         if (!ssid)
1186                 wpa_s->prev_sched_ssid = NULL;
1187
1188         return 0;
1189 }
1190
1191
1192 /**
1193  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1194  * @wpa_s: Pointer to wpa_supplicant data
1195  *
1196  * This function is used to cancel a scan request scheduled with
1197  * wpa_supplicant_req_scan().
1198  */
1199 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1200 {
1201         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1202         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1203         wpas_p2p_continue_after_scan(wpa_s);
1204 }
1205
1206
1207 /**
1208  * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1209  * @wpa_s: Pointer to wpa_supplicant data
1210  *
1211  * This function is used to stop a delayed scheduled scan.
1212  */
1213 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1214 {
1215         if (!wpa_s->sched_scan_supported)
1216                 return;
1217
1218         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1219         eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1220                              wpa_s, NULL);
1221 }
1222
1223
1224 /**
1225  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1226  * @wpa_s: Pointer to wpa_supplicant data
1227  *
1228  * This function is used to stop a periodic scheduled scan.
1229  */
1230 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1231 {
1232         if (!wpa_s->sched_scanning)
1233                 return;
1234
1235         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1236         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1237         wpa_supplicant_stop_sched_scan(wpa_s);
1238 }
1239
1240
1241 /**
1242  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1243  * @wpa_s: Pointer to wpa_supplicant data
1244  * @scanning: Whether scanning is currently in progress
1245  *
1246  * This function is to generate scanning notifycations. It is called whenever
1247  * there may have been a change in scanning (scan started, completed, stopped).
1248  * wpas_notify_scanning() is called whenever the scanning state changed from the
1249  * previously notified state.
1250  */
1251 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1252                                     int scanning)
1253 {
1254         if (wpa_s->scanning != scanning) {
1255                 wpa_s->scanning = scanning;
1256                 wpas_notify_scanning(wpa_s);
1257         }
1258 }
1259
1260
1261 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1262 {
1263         int rate = 0;
1264         const u8 *ie;
1265         int i;
1266
1267         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1268         for (i = 0; ie && i < ie[1]; i++) {
1269                 if ((ie[i + 2] & 0x7f) > rate)
1270                         rate = ie[i + 2] & 0x7f;
1271         }
1272
1273         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1274         for (i = 0; ie && i < ie[1]; i++) {
1275                 if ((ie[i + 2] & 0x7f) > rate)
1276                         rate = ie[i + 2] & 0x7f;
1277         }
1278
1279         return rate;
1280 }
1281
1282
1283 /**
1284  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1285  * @res: Scan result entry
1286  * @ie: Information element identitifier (WLAN_EID_*)
1287  * Returns: Pointer to the information element (id field) or %NULL if not found
1288  *
1289  * This function returns the first matching information element in the scan
1290  * result.
1291  */
1292 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1293 {
1294         const u8 *end, *pos;
1295
1296         pos = (const u8 *) (res + 1);
1297         end = pos + res->ie_len;
1298
1299         while (pos + 1 < end) {
1300                 if (pos + 2 + pos[1] > end)
1301                         break;
1302                 if (pos[0] == ie)
1303                         return pos;
1304                 pos += 2 + pos[1];
1305         }
1306
1307         return NULL;
1308 }
1309
1310
1311 /**
1312  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1313  * @res: Scan result entry
1314  * @vendor_type: Vendor type (four octets starting the IE payload)
1315  * Returns: Pointer to the information element (id field) or %NULL if not found
1316  *
1317  * This function returns the first matching information element in the scan
1318  * result.
1319  */
1320 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1321                                   u32 vendor_type)
1322 {
1323         const u8 *end, *pos;
1324
1325         pos = (const u8 *) (res + 1);
1326         end = pos + res->ie_len;
1327
1328         while (pos + 1 < end) {
1329                 if (pos + 2 + pos[1] > end)
1330                         break;
1331                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1332                     vendor_type == WPA_GET_BE32(&pos[2]))
1333                         return pos;
1334                 pos += 2 + pos[1];
1335         }
1336
1337         return NULL;
1338 }
1339
1340
1341 /**
1342  * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1343  * @res: Scan result entry
1344  * @vendor_type: Vendor type (four octets starting the IE payload)
1345  * Returns: Pointer to the information element (id field) or %NULL if not found
1346  *
1347  * This function returns the first matching information element in the scan
1348  * result.
1349  *
1350  * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1351  * from Beacon frames instead of either Beacon or Probe Response frames.
1352  */
1353 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1354                                          u32 vendor_type)
1355 {
1356         const u8 *end, *pos;
1357
1358         if (res->beacon_ie_len == 0)
1359                 return NULL;
1360
1361         pos = (const u8 *) (res + 1);
1362         pos += res->ie_len;
1363         end = pos + res->beacon_ie_len;
1364
1365         while (pos + 1 < end) {
1366                 if (pos + 2 + pos[1] > end)
1367                         break;
1368                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1369                     vendor_type == WPA_GET_BE32(&pos[2]))
1370                         return pos;
1371                 pos += 2 + pos[1];
1372         }
1373
1374         return NULL;
1375 }
1376
1377
1378 /**
1379  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1380  * @res: Scan result entry
1381  * @vendor_type: Vendor type (four octets starting the IE payload)
1382  * Returns: Pointer to the information element payload or %NULL if not found
1383  *
1384  * This function returns concatenated payload of possibly fragmented vendor
1385  * specific information elements in the scan result. The caller is responsible
1386  * for freeing the returned buffer.
1387  */
1388 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1389                                              u32 vendor_type)
1390 {
1391         struct wpabuf *buf;
1392         const u8 *end, *pos;
1393
1394         buf = wpabuf_alloc(res->ie_len);
1395         if (buf == NULL)
1396                 return NULL;
1397
1398         pos = (const u8 *) (res + 1);
1399         end = pos + res->ie_len;
1400
1401         while (pos + 1 < end) {
1402                 if (pos + 2 + pos[1] > end)
1403                         break;
1404                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1405                     vendor_type == WPA_GET_BE32(&pos[2]))
1406                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1407                 pos += 2 + pos[1];
1408         }
1409
1410         if (wpabuf_len(buf) == 0) {
1411                 wpabuf_free(buf);
1412                 buf = NULL;
1413         }
1414
1415         return buf;
1416 }
1417
1418
1419 /*
1420  * Channels with a great SNR can operate at full rate. What is a great SNR?
1421  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1422  * rule of thumb is that any SNR above 20 is good." This one
1423  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1424  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1425  * conservative value.
1426  */
1427 #define GREAT_SNR 30
1428
1429 /* Compare function for sorting scan results. Return >0 if @b is considered
1430  * better. */
1431 static int wpa_scan_result_compar(const void *a, const void *b)
1432 {
1433 #define IS_5GHZ(n) (n > 4000)
1434 #define MIN(a,b) a < b ? a : b
1435         struct wpa_scan_res **_wa = (void *) a;
1436         struct wpa_scan_res **_wb = (void *) b;
1437         struct wpa_scan_res *wa = *_wa;
1438         struct wpa_scan_res *wb = *_wb;
1439         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1440         int snr_a, snr_b;
1441
1442         /* WPA/WPA2 support preferred */
1443         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1444                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1445         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1446                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1447
1448         if (wpa_b && !wpa_a)
1449                 return 1;
1450         if (!wpa_b && wpa_a)
1451                 return -1;
1452
1453         /* privacy support preferred */
1454         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1455             (wb->caps & IEEE80211_CAP_PRIVACY))
1456                 return 1;
1457         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1458             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1459                 return -1;
1460
1461         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1462             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1463                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1464                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1465         } else {
1466                 /* Not suitable information to calculate SNR, so use level */
1467                 snr_a = wa->level;
1468                 snr_b = wb->level;
1469         }
1470
1471         /* best/max rate preferred if SNR close enough */
1472         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1473             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1474                 maxrate_a = wpa_scan_get_max_rate(wa);
1475                 maxrate_b = wpa_scan_get_max_rate(wb);
1476                 if (maxrate_a != maxrate_b)
1477                         return maxrate_b - maxrate_a;
1478                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1479                         return IS_5GHZ(wa->freq) ? -1 : 1;
1480         }
1481
1482         /* use freq for channel preference */
1483
1484         /* all things being equal, use SNR; if SNRs are
1485          * identical, use quality values since some drivers may only report
1486          * that value and leave the signal level zero */
1487         if (snr_b == snr_a)
1488                 return wb->qual - wa->qual;
1489         return snr_b - snr_a;
1490 #undef MIN
1491 #undef IS_5GHZ
1492 }
1493
1494
1495 #ifdef CONFIG_WPS
1496 /* Compare function for sorting scan results when searching a WPS AP for
1497  * provisioning. Return >0 if @b is considered better. */
1498 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1499 {
1500         struct wpa_scan_res **_wa = (void *) a;
1501         struct wpa_scan_res **_wb = (void *) b;
1502         struct wpa_scan_res *wa = *_wa;
1503         struct wpa_scan_res *wb = *_wb;
1504         int uses_wps_a, uses_wps_b;
1505         struct wpabuf *wps_a, *wps_b;
1506         int res;
1507
1508         /* Optimization - check WPS IE existence before allocated memory and
1509          * doing full reassembly. */
1510         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1511         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1512         if (uses_wps_a && !uses_wps_b)
1513                 return -1;
1514         if (!uses_wps_a && uses_wps_b)
1515                 return 1;
1516
1517         if (uses_wps_a && uses_wps_b) {
1518                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1519                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1520                 res = wps_ap_priority_compar(wps_a, wps_b);
1521                 wpabuf_free(wps_a);
1522                 wpabuf_free(wps_b);
1523                 if (res)
1524                         return res;
1525         }
1526
1527         /*
1528          * Do not use current AP security policy as a sorting criteria during
1529          * WPS provisioning step since the AP may get reconfigured at the
1530          * completion of provisioning.
1531          */
1532
1533         /* all things being equal, use signal level; if signal levels are
1534          * identical, use quality values since some drivers may only report
1535          * that value and leave the signal level zero */
1536         if (wb->level == wa->level)
1537                 return wb->qual - wa->qual;
1538         return wb->level - wa->level;
1539 }
1540 #endif /* CONFIG_WPS */
1541
1542
1543 static void dump_scan_res(struct wpa_scan_results *scan_res)
1544 {
1545 #ifndef CONFIG_NO_STDOUT_DEBUG
1546         size_t i;
1547
1548         if (scan_res->res == NULL || scan_res->num == 0)
1549                 return;
1550
1551         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1552
1553         for (i = 0; i < scan_res->num; i++) {
1554                 struct wpa_scan_res *r = scan_res->res[i];
1555                 u8 *pos;
1556                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1557                     == WPA_SCAN_LEVEL_DBM) {
1558                         int snr = r->level - r->noise;
1559                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1560                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1561                                    "age=%u",
1562                                    MAC2STR(r->bssid), r->freq, r->qual,
1563                                    r->noise, r->level, snr,
1564                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1565                                    r->age);
1566                 } else {
1567                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1568                                    "noise=%d level=%d flags=0x%x age=%u",
1569                                    MAC2STR(r->bssid), r->freq, r->qual,
1570                                    r->noise, r->level, r->flags, r->age);
1571                 }
1572                 pos = (u8 *) (r + 1);
1573                 if (r->ie_len)
1574                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1575                 pos += r->ie_len;
1576                 if (r->beacon_ie_len)
1577                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1578                                     pos, r->beacon_ie_len);
1579         }
1580 #endif /* CONFIG_NO_STDOUT_DEBUG */
1581 }
1582
1583
1584 /**
1585  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1586  * @wpa_s: Pointer to wpa_supplicant data
1587  * @bssid: BSSID to check
1588  * Returns: 0 if the BSSID is filtered or 1 if not
1589  *
1590  * This function is used to filter out specific BSSIDs from scan reslts mainly
1591  * for testing purposes (SET bssid_filter ctrl_iface command).
1592  */
1593 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1594                                       const u8 *bssid)
1595 {
1596         size_t i;
1597
1598         if (wpa_s->bssid_filter == NULL)
1599                 return 1;
1600
1601         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1602                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1603                               ETH_ALEN) == 0)
1604                         return 1;
1605         }
1606
1607         return 0;
1608 }
1609
1610
1611 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1612                             struct wpa_scan_results *res)
1613 {
1614         size_t i, j;
1615
1616         if (wpa_s->bssid_filter == NULL)
1617                 return;
1618
1619         for (i = 0, j = 0; i < res->num; i++) {
1620                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1621                                                       res->res[i]->bssid)) {
1622                         res->res[j++] = res->res[i];
1623                 } else {
1624                         os_free(res->res[i]);
1625                         res->res[i] = NULL;
1626                 }
1627         }
1628
1629         if (res->num != j) {
1630                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1631                            (int) (res->num - j));
1632                 res->num = j;
1633         }
1634 }
1635
1636
1637 /**
1638  * wpa_supplicant_get_scan_results - Get scan results
1639  * @wpa_s: Pointer to wpa_supplicant data
1640  * @info: Information about what was scanned or %NULL if not available
1641  * @new_scan: Whether a new scan was performed
1642  * Returns: Scan results, %NULL on failure
1643  *
1644  * This function request the current scan results from the driver and updates
1645  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1646  * results with wpa_scan_results_free().
1647  */
1648 struct wpa_scan_results *
1649 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1650                                 struct scan_info *info, int new_scan)
1651 {
1652         struct wpa_scan_results *scan_res;
1653         size_t i;
1654         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1655
1656         scan_res = wpa_drv_get_scan_results2(wpa_s);
1657         if (scan_res == NULL) {
1658                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1659                 return NULL;
1660         }
1661         if (scan_res->fetch_time.sec == 0) {
1662                 /*
1663                  * Make sure we have a valid timestamp if the driver wrapper
1664                  * does not set this.
1665                  */
1666                 os_get_time(&scan_res->fetch_time);
1667         }
1668         filter_scan_res(wpa_s, scan_res);
1669
1670 #ifdef CONFIG_WPS
1671         if (wpas_wps_in_progress(wpa_s)) {
1672                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1673                         "provisioning rules");
1674                 compar = wpa_scan_result_wps_compar;
1675         }
1676 #endif /* CONFIG_WPS */
1677
1678         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1679               compar);
1680         dump_scan_res(scan_res);
1681
1682         wpa_bss_update_start(wpa_s);
1683         for (i = 0; i < scan_res->num; i++)
1684                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1685                                         &scan_res->fetch_time);
1686         wpa_bss_update_end(wpa_s, info, new_scan);
1687
1688         return scan_res;
1689 }
1690
1691
1692 /**
1693  * wpa_supplicant_update_scan_results - Update scan results from the driver
1694  * @wpa_s: Pointer to wpa_supplicant data
1695  * Returns: 0 on success, -1 on failure
1696  *
1697  * This function updates the BSS table within wpa_supplicant based on the
1698  * currently available scan results from the driver without requesting a new
1699  * scan. This is used in cases where the driver indicates an association
1700  * (including roaming within ESS) and wpa_supplicant does not yet have the
1701  * needed information to complete the connection (e.g., to perform validation
1702  * steps in 4-way handshake).
1703  */
1704 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1705 {
1706         struct wpa_scan_results *scan_res;
1707         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1708         if (scan_res == NULL)
1709                 return -1;
1710         wpa_scan_results_free(scan_res);
1711
1712         return 0;
1713 }
1714
1715
1716 /**
1717  * scan_only_handler - Reports scan results
1718  */
1719 void scan_only_handler(struct wpa_supplicant *wpa_s,
1720                        struct wpa_scan_results *scan_res)
1721 {
1722         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1723         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1724         wpas_notify_scan_results(wpa_s);
1725         wpas_notify_scan_done(wpa_s, 1);
1726 }
1727
1728
1729 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1730 {
1731         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1732 }