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         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 549         int ret;
 550         struct wpabuf *extra_ie = NULL;
 551         struct wpa_driver_scan_params params;
 552         struct wpa_driver_scan_params *scan_params;
 553         size_t max_ssids;
 554         enum wpa_states prev_state;
 555
 556         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 557                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 558                 wpas_p2p_continue_after_scan(wpa_s);
 559                 return;
 560         }
 561
 562         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 563                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 564                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 565                 wpas_p2p_continue_after_scan(wpa_s);
 566                 return;
 567         }
 568
 569         if (wpa_s->scanning) {
 570                 /*
 571                  * If we are already in scanning state, we shall reschedule the
 572                  * the incoming scan request.
 573                  */
 574                 wpa_dbg(wpa_s, MSG_DEBUG, "Already scanning - Reschedule the incoming scan req");
 575                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 576                 return;
 577         }
 578
 579         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 580             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 581                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 582                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 583                 wpas_p2p_continue_after_scan(wpa_s);
 584                 return;
 585         }
 586
 587         if (wpa_s->conf->ap_scan != 0 &&
 588             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 589                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 590                         "overriding ap_scan configuration");
 591                 wpa_s->conf->ap_scan = 0;
 592                 wpas_notify_ap_scan_changed(wpa_s);
 593         }
 594
 595         if (wpa_s->conf->ap_scan == 0) {
 596                 wpa_supplicant_gen_assoc_event(wpa_s);
 597                 return;
 598         }
 599
 600 #ifdef CONFIG_P2P
 601         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
 602                 if (wpa_s->sta_scan_pending &&
 603                     wpas_p2p_in_progress(wpa_s) == 2 &&
 604                     wpa_s->global->p2p_cb_on_scan_complete) {
 605                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 606                                 "mode scan during P2P search");
 607                 } else {
 608                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 609                                 "while P2P operation is in progress");
 610                         wpa_s->sta_scan_pending = 1;
 611                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 612                         return;
 613                 }
 614         }
 615 #endif /* CONFIG_P2P */
 616
 617 #ifdef CONFIG_GAS
 618         if (gas_query_in_progress(wpa_s->gas)) {
 619                 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
 620                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 621                 return;
 622         }
 623 #endif /* CONFIG_GAS */
 624
 625         if (wpa_s->conf->ap_scan == 2)
 626                 max_ssids = 1;
 627         else {
 628                 max_ssids = wpa_s->max_scan_ssids;
 629                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 630                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 631         }
 632
 633         scan_req = wpa_s->scan_req;
 634         wpa_s->scan_req = NORMAL_SCAN_REQ;
 635
 636         os_memset(&params, 0, sizeof(params));
 637
 638         prev_state = wpa_s->wpa_state;
 639         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 640             wpa_s->wpa_state == WPA_INACTIVE)
 641                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 642
 643         /*
 644          * If autoscan has set its own scanning parameters
 645          */
 646         if (wpa_s->autoscan_params != NULL) {
 647                 scan_params = wpa_s->autoscan_params;
 648                 goto scan;
 649         }
 650
 651         if (scan_req != MANUAL_SCAN_REQ && 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 (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 691                 wpa_s->connect_without_scan = NULL;
 692                 wpa_s->prev_scan_wildcard = 0;
 693                 wpa_supplicant_assoc_try(wpa_s, ssid);
 694                 return;
 695         } else if (wpa_s->conf->ap_scan == 2) {
 696                 /*
 697                  * User-initiated scan request in ap_scan == 2; scan with
 698                  * wildcard SSID.
 699                  */
 700                 ssid = NULL;
 701         } else {
 702                 struct wpa_ssid *start = ssid, *tssid;
 703                 int freqs_set = 0;
 704                 if (ssid == NULL && max_ssids > 1)
 705                         ssid = wpa_s->conf->ssid;
 706                 while (ssid) {
 707                         if (!wpas_network_disabled(wpa_s, ssid) &&
 708                             ssid->scan_ssid) {
 709                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 710                                                   ssid->ssid, ssid->ssid_len);
 711                                 params.ssids[params.num_ssids].ssid =
 712                                         ssid->ssid;
 713                                 params.ssids[params.num_ssids].ssid_len =
 714                                         ssid->ssid_len;
 715                                 params.num_ssids++;
 716                                 if (params.num_ssids + 1 >= max_ssids)
 717                                         break;
 718                         }
 719                         ssid = ssid->next;
 720                         if (ssid == start)
 721                                 break;
 722                         if (ssid == NULL && max_ssids > 1 &&
 723                             start != wpa_s->conf->ssid)
 724                                 ssid = wpa_s->conf->ssid;
 725                 }
 726
 727                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 728                         if (wpas_network_disabled(wpa_s, tssid))
 729                                 continue;
 730                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 731                                 int_array_concat(&params.freqs,
 732                                                  tssid->scan_freq);
 733                         } else {
 734                                 os_free(params.freqs);
 735                                 params.freqs = NULL;
 736                         }
 737                         freqs_set = 1;
 738                 }
 739                 int_array_sort_unique(params.freqs);
 740         }
 741
 742         if (ssid && max_ssids == 1) {
 743                 /*
 744                  * If the driver is limited to 1 SSID at a time interleave
 745                  * wildcard SSID scans with specific SSID scans to avoid
 746                  * waiting a long time for a wildcard scan.
 747                  */
 748                 if (!wpa_s->prev_scan_wildcard) {
 749                         params.ssids[0].ssid = NULL;
 750                         params.ssids[0].ssid_len = 0;
 751                         wpa_s->prev_scan_wildcard = 1;
 752                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 753                                 "wildcard SSID (Interleave with specific)");
 754                 } else {
 755                         wpa_s->prev_scan_ssid = ssid;
 756                         wpa_s->prev_scan_wildcard = 0;
 757                         wpa_dbg(wpa_s, MSG_DEBUG,
 758                                 "Starting AP scan for specific SSID: %s",
 759                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 760                 }
 761         } else if (ssid) {
 762                 /* max_ssids > 1 */
 763
 764                 wpa_s->prev_scan_ssid = ssid;
 765                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 766                         "the scan request");
 767                 params.num_ssids++;
 768         } else {
 769                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 770                 params.num_ssids++;
 771                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 772                         "SSID");
 773         }
 774 #ifdef CONFIG_P2P
 775 ssid_list_set:
 776 #endif /* CONFIG_P2P */
 777
 778         wpa_supplicant_optimize_freqs(wpa_s, &params);
 779         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 780
 781         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 782                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 783                         "generated frequency list");
 784                 params.freqs = wpa_s->next_scan_freqs;
 785         } else
 786                 os_free(wpa_s->next_scan_freqs);
 787         wpa_s->next_scan_freqs = NULL;
 788         wpa_setband_scan_freqs(wpa_s, &params);
 789
 790         /* See if user specified frequencies. If so, scan only those. */
 791         if (wpa_s->conf->freq_list && !params.freqs) {
 792                 wpa_dbg(wpa_s, MSG_DEBUG,
 793                         "Optimize scan based on conf->freq_list");
 794                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 795         }
 796
 797         /* Use current associated channel? */
 798         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 799                 unsigned int num = wpa_s->num_multichan_concurrent;
 800
 801                 params.freqs = os_calloc(num + 1, sizeof(int));
 802                 if (params.freqs) {
 803                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 804                         if (num > 0) {
 805                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
 806                                         "current operating channels since "
 807                                         "scan_cur_freq is enabled");
 808                         } else {
 809                                 os_free(params.freqs);
 810                                 params.freqs = NULL;
 811                         }
 812                 }
 813         }
 814
 815         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 816                 wpa_s->conf, &params.num_filter_ssids);
 817         if (extra_ie) {
 818                 params.extra_ies = wpabuf_head(extra_ie);
 819                 params.extra_ies_len = wpabuf_len(extra_ie);
 820         }
 821
 822 #ifdef CONFIG_P2P
 823         if (wpa_s->p2p_in_provisioning ||
 824             (wpa_s->show_group_started && wpa_s->go_params)) {
 825                 /*
 826                  * The interface may not yet be in P2P mode, so we have to
 827                  * explicitly request P2P probe to disable CCK rates.
 828                  */
 829                 params.p2p_probe = 1;
 830         }
 831 #endif /* CONFIG_P2P */
 832
 833         scan_params = &params;
 834
 835 scan:
 836 #ifdef CONFIG_P2P
 837         /*
 838          * If the driver does not support multi-channel concurrency and a
 839          * virtual interface that shares the same radio with the wpa_s interface
 840          * is operating there may not be need to scan other channels apart from
 841          * the current operating channel on the other virtual interface. Filter
 842          * out other channels in case we are trying to find a connection for a
 843          * station interface when we are not configured to prefer station
 844          * connection and a concurrent operation is already in process.
 845          */
 846         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 847             !scan_params->freqs && !params.freqs &&
 848             wpas_is_p2p_prioritized(wpa_s) &&
 849             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 850             non_p2p_network_enabled(wpa_s)) {
 851                 unsigned int num = wpa_s->num_multichan_concurrent;
 852
 853                 params.freqs = os_calloc(num + 1, sizeof(int));
 854                 if (params.freqs) {
 855                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 856                         if (num > 0 && num == wpa_s->num_multichan_concurrent) {
 857                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
 858                         } else {
 859                                 os_free(params.freqs);
 860                                 params.freqs = NULL;
 861                         }
 862                 }
 863         }
 864 #endif /* CONFIG_P2P */
 865
 866         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 867
 868         wpabuf_free(extra_ie);
 869         os_free(params.freqs);
 870         os_free(params.filter_ssids);
 871
 872         if (ret) {
 873                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 874                 if (prev_state != wpa_s->wpa_state)
 875                         wpa_supplicant_set_state(wpa_s, prev_state);
 876                 /* Restore scan_req since we will try to scan again */
 877                 wpa_s->scan_req = scan_req;
 878                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 879         } else {
 880                 wpa_s->scan_for_connection = 0;
 881         }
 882 }
 883
 884
 885 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 886 {
 887         struct os_time remaining, new_int;
 888         int cancelled;
 889
 890         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 891                                              &remaining);
 892
 893         new_int.sec = sec;
 894         new_int.usec = 0;
 895         if (cancelled && os_time_before(&remaining, &new_int)) {
 896                 new_int.sec = remaining.sec;
 897                 new_int.usec = remaining.usec;
 898         }
 899
 900         if (cancelled) {
 901                 eloop_register_timeout(new_int.sec, new_int.usec,
 902                                        wpa_supplicant_scan, wpa_s, NULL);
 903         }
 904         wpa_s->scan_interval = sec;
 905 }
 906
 907
 908 /**
 909  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 910  * @wpa_s: Pointer to wpa_supplicant data
 911  * @sec: Number of seconds after which to scan
 912  * @usec: Number of microseconds after which to scan
 913  *
 914  * This function is used to schedule a scan for neighboring access points after
 915  * the specified time.
 916  */
 917 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 918 {
 919         if (eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL))
 920         {
 921                 wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d sec %d usec",
 922                         sec, usec);
 923                 return;
 924         }
 925
 926         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 927                 sec, usec);
 928         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 929         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 930 }
 931
 932
 933 /**
 934  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 935  * @wpa_s: Pointer to wpa_supplicant data
 936  * @sec: Number of seconds after which to scan
 937  * @usec: Number of microseconds after which to scan
 938  * Returns: 0 on success or -1 otherwise
 939  *
 940  * This function is used to schedule periodic scans for neighboring
 941  * access points after the specified time.
 942  */
 943 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 944                                       int sec, int usec)
 945 {
 946         if (!wpa_s->sched_scan_supported)
 947                 return -1;
 948
 949         eloop_register_timeout(sec, usec,
 950                                wpa_supplicant_delayed_sched_scan_timeout,
 951                                wpa_s, NULL);
 952
 953         return 0;
 954 }
 955
 956
 957 /**
 958  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 959  * @wpa_s: Pointer to wpa_supplicant data
 960  * Returns: 0 is sched_scan was started or -1 otherwise
 961  *
 962  * This function is used to schedule periodic scans for neighboring
 963  * access points repeating the scan continuously.
 964  */
 965 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 966 {
 967         struct wpa_driver_scan_params params;
 968         struct wpa_driver_scan_params *scan_params;
 969         enum wpa_states prev_state;
 970         struct wpa_ssid *ssid = NULL;
 971         struct wpabuf *extra_ie = NULL;
 972         int ret;
 973         unsigned int max_sched_scan_ssids;
 974         int wildcard = 0;
 975         int need_ssids;
 976
 977         if (!wpa_s->sched_scan_supported)
 978                 return -1;
 979
 980         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 981                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 982         else
 983                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 984         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 985                 return -1;
 986
 987         if (wpa_s->sched_scanning) {
 988                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 989                 return 0;
 990         }
 991
 992         need_ssids = 0;
 993         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 994                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 995                         /* Use wildcard SSID to find this network */
 996                         wildcard = 1;
 997                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 998                            ssid->ssid_len)
 999                         need_ssids++;
1000
1001 #ifdef CONFIG_WPS
1002                 if (!wpas_network_disabled(wpa_s, ssid) &&
1003                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
1004                         /*
1005                          * Normal scan is more reliable and faster for WPS
1006                          * operations and since these are for short periods of
1007                          * time, the benefit of trying to use sched_scan would
1008                          * be limited.
1009                          */
1010                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1011                                 "sched_scan for WPS");
1012                         return -1;
1013                 }
1014 #endif /* CONFIG_WPS */
1015         }
1016         if (wildcard)
1017                 need_ssids++;
1018
1019         if (wpa_s->normal_scans < 3 &&
1020             (need_ssids <= wpa_s->max_scan_ssids ||
1021              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
1022                 /*
1023                  * When normal scan can speed up operations, use that for the
1024                  * first operations before starting the sched_scan to allow
1025                  * user space sleep more. We do this only if the normal scan
1026                  * has functionality that is suitable for this or if the
1027                  * sched_scan does not have better support for multiple SSIDs.
1028                  */
1029                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1030                         "sched_scan for initial scans (normal_scans=%d)",
1031                         wpa_s->normal_scans);
1032                 return -1;
1033         }
1034
1035         os_memset(&params, 0, sizeof(params));
1036
1037         /* If we can't allocate space for the filters, we just don't filter */
1038         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1039                                         sizeof(struct wpa_driver_scan_filter));
1040
1041         prev_state = wpa_s->wpa_state;
1042         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1043             wpa_s->wpa_state == WPA_INACTIVE)
1044                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1045
1046         if (wpa_s->autoscan_params != NULL) {
1047                 scan_params = wpa_s->autoscan_params;
1048                 goto scan;
1049         }
1050
1051         /* Find the starting point from which to continue scanning */
1052         ssid = wpa_s->conf->ssid;
1053         if (wpa_s->prev_sched_ssid) {
1054                 while (ssid) {
1055                         if (ssid == wpa_s->prev_sched_ssid) {
1056                                 ssid = ssid->next;
1057                                 break;
1058                         }
1059                         ssid = ssid->next;
1060                 }
1061         }
1062
1063         if (!ssid || !wpa_s->prev_sched_ssid) {
1064                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1065                 if (wpa_s->conf->sched_scan_interval)
1066                         wpa_s->sched_scan_interval =
1067                                 wpa_s->conf->sched_scan_interval;
1068                 if (wpa_s->sched_scan_interval == 0)
1069                         wpa_s->sched_scan_interval = 10;
1070                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1071                 wpa_s->first_sched_scan = 1;
1072                 ssid = wpa_s->conf->ssid;
1073                 wpa_s->prev_sched_ssid = ssid;
1074         }
1075
1076         if (wildcard) {
1077                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1078                 params.num_ssids++;
1079         }
1080
1081         while (ssid) {
1082                 if (wpas_network_disabled(wpa_s, ssid))
1083                         goto next;
1084
1085                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1086                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1087                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1088                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1089                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1090                                   ssid->ssid, ssid->ssid_len);
1091                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1092                                 ssid->ssid_len;
1093                         params.num_filter_ssids++;
1094                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1095                 {
1096                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1097                                 "filter for sched_scan - drop filter");
1098                         os_free(params.filter_ssids);
1099                         params.filter_ssids = NULL;
1100                         params.num_filter_ssids = 0;
1101                 }
1102
1103                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1104                         if (params.num_ssids == max_sched_scan_ssids)
1105                                 break; /* only room for broadcast SSID */
1106                         wpa_dbg(wpa_s, MSG_DEBUG,
1107                                 "add to active scan ssid: %s",
1108                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1109                         params.ssids[params.num_ssids].ssid =
1110                                 ssid->ssid;
1111                         params.ssids[params.num_ssids].ssid_len =
1112                                 ssid->ssid_len;
1113                         params.num_ssids++;
1114                         if (params.num_ssids >= max_sched_scan_ssids) {
1115                                 wpa_s->prev_sched_ssid = ssid;
1116                                 do {
1117                                         ssid = ssid->next;
1118                                 } while (ssid &&
1119                                          (wpas_network_disabled(wpa_s, ssid) ||
1120                                           !ssid->scan_ssid));
1121                                 break;
1122                         }
1123                 }
1124
1125         next:
1126                 wpa_s->prev_sched_ssid = ssid;
1127                 ssid = ssid->next;
1128         }
1129
1130         if (params.num_filter_ssids == 0) {
1131                 os_free(params.filter_ssids);
1132                 params.filter_ssids = NULL;
1133         }
1134
1135         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1136         if (extra_ie) {
1137                 params.extra_ies = wpabuf_head(extra_ie);
1138                 params.extra_ies_len = wpabuf_len(extra_ie);
1139         }
1140
1141         scan_params = &params;
1142
1143 scan:
1144         if (ssid || !wpa_s->first_sched_scan) {
1145                 wpa_dbg(wpa_s, MSG_DEBUG,
1146                         "Starting sched scan: interval %d timeout %d",
1147                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1148         } else {
1149                 wpa_dbg(wpa_s, MSG_DEBUG,
1150                         "Starting sched scan: interval %d (no timeout)",
1151                         wpa_s->sched_scan_interval);
1152         }
1153
1154         wpa_setband_scan_freqs(wpa_s, scan_params);
1155
1156         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1157                                               wpa_s->sched_scan_interval);
1158         wpabuf_free(extra_ie);
1159         os_free(params.filter_ssids);
1160         if (ret) {
1161                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1162                 if (prev_state != wpa_s->wpa_state)
1163                         wpa_supplicant_set_state(wpa_s, prev_state);
1164                 return ret;
1165         }
1166
1167         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1168         if (ssid || !wpa_s->first_sched_scan) {
1169                 wpa_s->sched_scan_timed_out = 0;
1170                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1171                                        wpa_supplicant_sched_scan_timeout,
1172                                        wpa_s, NULL);
1173                 wpa_s->first_sched_scan = 0;
1174                 wpa_s->sched_scan_timeout /= 2;
1175                 wpa_s->sched_scan_interval *= 2;
1176                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1177                         wpa_s->sched_scan_interval = 10;
1178                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1179                 }
1180         }
1181
1182         /* If there is no more ssids, start next time from the beginning */
1183         if (!ssid)
1184                 wpa_s->prev_sched_ssid = NULL;
1185
1186         return 0;
1187 }
1188
1189
1190 /**
1191  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1192  * @wpa_s: Pointer to wpa_supplicant data
1193  *
1194  * This function is used to cancel a scan request scheduled with
1195  * wpa_supplicant_req_scan().
1196  */
1197 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1198 {
1199         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1200         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1201         wpas_p2p_continue_after_scan(wpa_s);
1202 }
1203
1204
1205 /**
1206  * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1207  * @wpa_s: Pointer to wpa_supplicant data
1208  *
1209  * This function is used to stop a delayed scheduled scan.
1210  */
1211 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1212 {
1213         if (!wpa_s->sched_scan_supported)
1214                 return;
1215
1216         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1217         eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1218                              wpa_s, NULL);
1219 }
1220
1221
1222 /**
1223  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1224  * @wpa_s: Pointer to wpa_supplicant data
1225  *
1226  * This function is used to stop a periodic scheduled scan.
1227  */
1228 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1229 {
1230         if (!wpa_s->sched_scanning)
1231                 return;
1232
1233         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1234         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1235         wpa_supplicant_stop_sched_scan(wpa_s);
1236 }
1237
1238
1239 /**
1240  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1241  * @wpa_s: Pointer to wpa_supplicant data
1242  * @scanning: Whether scanning is currently in progress
1243  *
1244  * This function is to generate scanning notifycations. It is called whenever
1245  * there may have been a change in scanning (scan started, completed, stopped).
1246  * wpas_notify_scanning() is called whenever the scanning state changed from the
1247  * previously notified state.
1248  */
1249 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1250                                     int scanning)
1251 {
1252         if (wpa_s->scanning != scanning) {
1253                 wpa_s->scanning = scanning;
1254                 wpas_notify_scanning(wpa_s);
1255         }
1256 }
1257
1258
1259 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1260 {
1261         int rate = 0;
1262         const u8 *ie;
1263         int i;
1264
1265         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1266         for (i = 0; ie && i < ie[1]; i++) {
1267                 if ((ie[i + 2] & 0x7f) > rate)
1268                         rate = ie[i + 2] & 0x7f;
1269         }
1270
1271         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1272         for (i = 0; ie && i < ie[1]; i++) {
1273                 if ((ie[i + 2] & 0x7f) > rate)
1274                         rate = ie[i + 2] & 0x7f;
1275         }
1276
1277         return rate;
1278 }
1279
1280
1281 /**
1282  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1283  * @res: Scan result entry
1284  * @ie: Information element identitifier (WLAN_EID_*)
1285  * Returns: Pointer to the information element (id field) or %NULL if not found
1286  *
1287  * This function returns the first matching information element in the scan
1288  * result.
1289  */
1290 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
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] == ie)
1301                         return pos;
1302                 pos += 2 + pos[1];
1303         }
1304
1305         return NULL;
1306 }
1307
1308
1309 /**
1310  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1311  * @res: Scan result entry
1312  * @vendor_type: Vendor type (four octets starting the IE payload)
1313  * Returns: Pointer to the information element (id field) or %NULL if not found
1314  *
1315  * This function returns the first matching information element in the scan
1316  * result.
1317  */
1318 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1319                                   u32 vendor_type)
1320 {
1321         const u8 *end, *pos;
1322
1323         pos = (const u8 *) (res + 1);
1324         end = pos + res->ie_len;
1325
1326         while (pos + 1 < end) {
1327                 if (pos + 2 + pos[1] > end)
1328                         break;
1329                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1330                     vendor_type == WPA_GET_BE32(&pos[2]))
1331                         return pos;
1332                 pos += 2 + pos[1];
1333         }
1334
1335         return NULL;
1336 }
1337
1338
1339 /**
1340  * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1341  * @res: Scan result entry
1342  * @vendor_type: Vendor type (four octets starting the IE payload)
1343  * Returns: Pointer to the information element (id field) or %NULL if not found
1344  *
1345  * This function returns the first matching information element in the scan
1346  * result.
1347  *
1348  * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1349  * from Beacon frames instead of either Beacon or Probe Response frames.
1350  */
1351 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1352                                          u32 vendor_type)
1353 {
1354         const u8 *end, *pos;
1355
1356         if (res->beacon_ie_len == 0)
1357                 return NULL;
1358
1359         pos = (const u8 *) (res + 1);
1360         pos += res->ie_len;
1361         end = pos + res->beacon_ie_len;
1362
1363         while (pos + 1 < end) {
1364                 if (pos + 2 + pos[1] > end)
1365                         break;
1366                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1367                     vendor_type == WPA_GET_BE32(&pos[2]))
1368                         return pos;
1369                 pos += 2 + pos[1];
1370         }
1371
1372         return NULL;
1373 }
1374
1375
1376 /**
1377  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1378  * @res: Scan result entry
1379  * @vendor_type: Vendor type (four octets starting the IE payload)
1380  * Returns: Pointer to the information element payload or %NULL if not found
1381  *
1382  * This function returns concatenated payload of possibly fragmented vendor
1383  * specific information elements in the scan result. The caller is responsible
1384  * for freeing the returned buffer.
1385  */
1386 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1387                                              u32 vendor_type)
1388 {
1389         struct wpabuf *buf;
1390         const u8 *end, *pos;
1391
1392         buf = wpabuf_alloc(res->ie_len);
1393         if (buf == NULL)
1394                 return NULL;
1395
1396         pos = (const u8 *) (res + 1);
1397         end = pos + res->ie_len;
1398
1399         while (pos + 1 < end) {
1400                 if (pos + 2 + pos[1] > end)
1401                         break;
1402                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1403                     vendor_type == WPA_GET_BE32(&pos[2]))
1404                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1405                 pos += 2 + pos[1];
1406         }
1407
1408         if (wpabuf_len(buf) == 0) {
1409                 wpabuf_free(buf);
1410                 buf = NULL;
1411         }
1412
1413         return buf;
1414 }
1415
1416
1417 /*
1418  * Channels with a great SNR can operate at full rate. What is a great SNR?
1419  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1420  * rule of thumb is that any SNR above 20 is good." This one
1421  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1422  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1423  * conservative value.
1424  */
1425 #define GREAT_SNR 30
1426
1427 /* Compare function for sorting scan results. Return >0 if @b is considered
1428  * better. */
1429 static int wpa_scan_result_compar(const void *a, const void *b)
1430 {
1431 #define IS_5GHZ(n) (n > 4000)
1432 #define MIN(a,b) a < b ? a : b
1433         struct wpa_scan_res **_wa = (void *) a;
1434         struct wpa_scan_res **_wb = (void *) b;
1435         struct wpa_scan_res *wa = *_wa;
1436         struct wpa_scan_res *wb = *_wb;
1437         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1438         int snr_a, snr_b;
1439
1440         /* WPA/WPA2 support preferred */
1441         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1442                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1443         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1444                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1445
1446         if (wpa_b && !wpa_a)
1447                 return 1;
1448         if (!wpa_b && wpa_a)
1449                 return -1;
1450
1451         /* privacy support preferred */
1452         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1453             (wb->caps & IEEE80211_CAP_PRIVACY))
1454                 return 1;
1455         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1456             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1457                 return -1;
1458
1459         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1460             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1461                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1462                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1463         } else {
1464                 /* Not suitable information to calculate SNR, so use level */
1465                 snr_a = wa->level;
1466                 snr_b = wb->level;
1467         }
1468
1469         /* best/max rate preferred if SNR close enough */
1470         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1471             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1472                 maxrate_a = wpa_scan_get_max_rate(wa);
1473                 maxrate_b = wpa_scan_get_max_rate(wb);
1474                 if (maxrate_a != maxrate_b)
1475                         return maxrate_b - maxrate_a;
1476                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1477                         return IS_5GHZ(wa->freq) ? -1 : 1;
1478         }
1479
1480         /* use freq for channel preference */
1481
1482         /* all things being equal, use SNR; if SNRs are
1483          * identical, use quality values since some drivers may only report
1484          * that value and leave the signal level zero */
1485         if (snr_b == snr_a)
1486                 return wb->qual - wa->qual;
1487         return snr_b - snr_a;
1488 #undef MIN
1489 #undef IS_5GHZ
1490 }
1491
1492
1493 #ifdef CONFIG_WPS
1494 /* Compare function for sorting scan results when searching a WPS AP for
1495  * provisioning. Return >0 if @b is considered better. */
1496 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1497 {
1498         struct wpa_scan_res **_wa = (void *) a;
1499         struct wpa_scan_res **_wb = (void *) b;
1500         struct wpa_scan_res *wa = *_wa;
1501         struct wpa_scan_res *wb = *_wb;
1502         int uses_wps_a, uses_wps_b;
1503         struct wpabuf *wps_a, *wps_b;
1504         int res;
1505
1506         /* Optimization - check WPS IE existence before allocated memory and
1507          * doing full reassembly. */
1508         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1509         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1510         if (uses_wps_a && !uses_wps_b)
1511                 return -1;
1512         if (!uses_wps_a && uses_wps_b)
1513                 return 1;
1514
1515         if (uses_wps_a && uses_wps_b) {
1516                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1517                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1518                 res = wps_ap_priority_compar(wps_a, wps_b);
1519                 wpabuf_free(wps_a);
1520                 wpabuf_free(wps_b);
1521                 if (res)
1522                         return res;
1523         }
1524
1525         /*
1526          * Do not use current AP security policy as a sorting criteria during
1527          * WPS provisioning step since the AP may get reconfigured at the
1528          * completion of provisioning.
1529          */
1530
1531         /* all things being equal, use signal level; if signal levels are
1532          * identical, use quality values since some drivers may only report
1533          * that value and leave the signal level zero */
1534         if (wb->level == wa->level)
1535                 return wb->qual - wa->qual;
1536         return wb->level - wa->level;
1537 }
1538 #endif /* CONFIG_WPS */
1539
1540
1541 static void dump_scan_res(struct wpa_scan_results *scan_res)
1542 {
1543 #ifndef CONFIG_NO_STDOUT_DEBUG
1544         size_t i;
1545
1546         if (scan_res->res == NULL || scan_res->num == 0)
1547                 return;
1548
1549         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1550
1551         for (i = 0; i < scan_res->num; i++) {
1552                 struct wpa_scan_res *r = scan_res->res[i];
1553                 u8 *pos;
1554                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1555                     == WPA_SCAN_LEVEL_DBM) {
1556                         int snr = r->level - r->noise;
1557                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1558                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1559                                    "age=%u",
1560                                    MAC2STR(r->bssid), r->freq, r->qual,
1561                                    r->noise, r->level, snr,
1562                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1563                                    r->age);
1564                 } else {
1565                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1566                                    "noise=%d level=%d flags=0x%x age=%u",
1567                                    MAC2STR(r->bssid), r->freq, r->qual,
1568                                    r->noise, r->level, r->flags, r->age);
1569                 }
1570                 pos = (u8 *) (r + 1);
1571                 if (r->ie_len)
1572                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1573                 pos += r->ie_len;
1574                 if (r->beacon_ie_len)
1575                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1576                                     pos, r->beacon_ie_len);
1577         }
1578 #endif /* CONFIG_NO_STDOUT_DEBUG */
1579 }
1580
1581
1582 /**
1583  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1584  * @wpa_s: Pointer to wpa_supplicant data
1585  * @bssid: BSSID to check
1586  * Returns: 0 if the BSSID is filtered or 1 if not
1587  *
1588  * This function is used to filter out specific BSSIDs from scan reslts mainly
1589  * for testing purposes (SET bssid_filter ctrl_iface command).
1590  */
1591 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1592                                       const u8 *bssid)
1593 {
1594         size_t i;
1595
1596         if (wpa_s->bssid_filter == NULL)
1597                 return 1;
1598
1599         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1600                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1601                               ETH_ALEN) == 0)
1602                         return 1;
1603         }
1604
1605         return 0;
1606 }
1607
1608
1609 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1610                             struct wpa_scan_results *res)
1611 {
1612         size_t i, j;
1613
1614         if (wpa_s->bssid_filter == NULL)
1615                 return;
1616
1617         for (i = 0, j = 0; i < res->num; i++) {
1618                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1619                                                       res->res[i]->bssid)) {
1620                         res->res[j++] = res->res[i];
1621                 } else {
1622                         os_free(res->res[i]);
1623                         res->res[i] = NULL;
1624                 }
1625         }
1626
1627         if (res->num != j) {
1628                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1629                            (int) (res->num - j));
1630                 res->num = j;
1631         }
1632 }
1633
1634
1635 /**
1636  * wpa_supplicant_get_scan_results - Get scan results
1637  * @wpa_s: Pointer to wpa_supplicant data
1638  * @info: Information about what was scanned or %NULL if not available
1639  * @new_scan: Whether a new scan was performed
1640  * Returns: Scan results, %NULL on failure
1641  *
1642  * This function request the current scan results from the driver and updates
1643  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1644  * results with wpa_scan_results_free().
1645  */
1646 struct wpa_scan_results *
1647 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1648                                 struct scan_info *info, int new_scan)
1649 {
1650         struct wpa_scan_results *scan_res;
1651         size_t i;
1652         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1653
1654         scan_res = wpa_drv_get_scan_results2(wpa_s);
1655         if (scan_res == NULL) {
1656                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1657                 return NULL;
1658         }
1659         if (scan_res->fetch_time.sec == 0) {
1660                 /*
1661                  * Make sure we have a valid timestamp if the driver wrapper
1662                  * does not set this.
1663                  */
1664                 os_get_time(&scan_res->fetch_time);
1665         }
1666         filter_scan_res(wpa_s, scan_res);
1667
1668 #ifdef CONFIG_WPS
1669         if (wpas_wps_in_progress(wpa_s)) {
1670                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1671                         "provisioning rules");
1672                 compar = wpa_scan_result_wps_compar;
1673         }
1674 #endif /* CONFIG_WPS */
1675
1676         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1677               compar);
1678         dump_scan_res(scan_res);
1679
1680         wpa_bss_update_start(wpa_s);
1681         for (i = 0; i < scan_res->num; i++)
1682                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1683                                         &scan_res->fetch_time);
1684         wpa_bss_update_end(wpa_s, info, new_scan);
1685
1686         return scan_res;
1687 }
1688
1689
1690 /**
1691  * wpa_supplicant_update_scan_results - Update scan results from the driver
1692  * @wpa_s: Pointer to wpa_supplicant data
1693  * Returns: 0 on success, -1 on failure
1694  *
1695  * This function updates the BSS table within wpa_supplicant based on the
1696  * currently available scan results from the driver without requesting a new
1697  * scan. This is used in cases where the driver indicates an association
1698  * (including roaming within ESS) and wpa_supplicant does not yet have the
1699  * needed information to complete the connection (e.g., to perform validation
1700  * steps in 4-way handshake).
1701  */
1702 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1703 {
1704         struct wpa_scan_results *scan_res;
1705         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1706         if (scan_res == NULL)
1707                 return -1;
1708         wpa_scan_results_free(scan_res);
1709
1710         return 0;
1711 }
1712
1713
1714 /**
1715  * scan_only_handler - Reports scan results
1716  */
1717 void scan_only_handler(struct wpa_supplicant *wpa_s,
1718                        struct wpa_scan_results *scan_res)
1719 {
1720         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1721         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1722         wpas_notify_scan_results(wpa_s);
1723         wpas_notify_scan_done(wpa_s, 1);
1724 }
1725
1726
1727 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1728 {
1729         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1730 }