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 "scan.h"
  25
  26
  27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  28 {
  29         struct wpa_ssid *ssid;
  30         union wpa_event_data data;
  31
  32         ssid = wpa_supplicant_get_ssid(wpa_s);
  33         if (ssid == NULL)
  34                 return;
  35
  36         if (wpa_s->current_ssid == NULL) {
  37                 wpa_s->current_ssid = ssid;
  38                 if (wpa_s->current_ssid != NULL)
  39                         wpas_notify_network_changed(wpa_s);
  40         }
  41         wpa_supplicant_initiate_eapol(wpa_s);
  42         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  43                 "network - generating associated event");
  44         os_memset(&data, 0, sizeof(data));
  45         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  46 }
  47
  48
  49 #ifdef CONFIG_WPS
  50 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  51                            enum wps_request_type *req_type)
  52 {
  53         struct wpa_ssid *ssid;
  54         int wps = 0;
  55
  56         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  57                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  58                         continue;
  59
  60                 wps = 1;
  61                 *req_type = wpas_wps_get_req_type(ssid);
  62                 if (!ssid->eap.phase1)
  63                         continue;
  64
  65                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  66                         return 2;
  67         }
  68
  69 #ifdef CONFIG_P2P
  70         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
  71             !wpa_s->conf->p2p_disabled) {
  72                 wpa_s->wps->dev.p2p = 1;
  73                 if (!wps) {
  74                         wps = 1;
  75                         *req_type = WPS_REQ_ENROLLEE_INFO;
  76                 }
  77         }
  78 #endif /* CONFIG_P2P */
  79
  80         return wps;
  81 }
  82 #endif /* CONFIG_WPS */
  83
  84
  85 /**
  86  * wpa_supplicant_enabled_networks - Check whether there are enabled networks
  87  * @wpa_s: Pointer to wpa_supplicant data
  88  * Returns: 0 if no networks are enabled, >0 if networks are enabled
  89  *
  90  * This function is used to figure out whether any networks (or Interworking
  91  * with enabled credentials and auto_interworking) are present in the current
  92  * configuration.
  93  */
  94 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  95 {
  96         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  97         int count = 0, disabled = 0;
  98         while (ssid) {
  99                 if (!wpas_network_disabled(wpa_s, ssid))
 100                         count++;
 101                 else
 102                         disabled++;
 103                 ssid = ssid->next;
 104         }
 105         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 106             wpa_s->conf->auto_interworking)
 107                 count++;
 108         if (count == 0 && disabled > 0) {
 109                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
 110                         "networks)", disabled);
 111         }
 112         return count;
 113 }
 114
 115
 116 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 117                                      struct wpa_ssid *ssid)
 118 {
 119         while (ssid) {
 120                 if (!wpas_network_disabled(wpa_s, ssid))
 121                         break;
 122                 ssid = ssid->next;
 123         }
 124
 125         /* ap_scan=2 mode - try to associate with each SSID. */
 126         if (ssid == NULL) {
 127                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 128                         "end of scan list - go back to beginning");
 129                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 130                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 131                 return;
 132         }
 133         if (ssid->next) {
 134                 /* Continue from the next SSID on the next attempt. */
 135                 wpa_s->prev_scan_ssid = ssid;
 136         } else {
 137                 /* Start from the beginning of the SSID list. */
 138                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 139         }
 140         wpa_supplicant_associate(wpa_s, NULL, ssid);
 141 }
 142
 143
 144 static int int_array_len(const int *a)
 145 {
 146         int i;
 147         for (i = 0; a && a[i]; i++)
 148                 ;
 149         return i;
 150 }
 151
 152
 153 static void int_array_concat(int **res, const int *a)
 154 {
 155         int reslen, alen, i;
 156         int *n;
 157
 158         reslen = int_array_len(*res);
 159         alen = int_array_len(a);
 160
 161         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 162         if (n == NULL) {
 163                 os_free(*res);
 164                 *res = NULL;
 165                 return;
 166         }
 167         for (i = 0; i <= alen; i++)
 168                 n[reslen + i] = a[i];
 169         *res = n;
 170 }
 171
 172
 173 static int freq_cmp(const void *a, const void *b)
 174 {
 175         int _a = *(int *) a;
 176         int _b = *(int *) b;
 177
 178         if (_a == 0)
 179                 return 1;
 180         if (_b == 0)
 181                 return -1;
 182         return _a - _b;
 183 }
 184
 185
 186 static void int_array_sort_unique(int *a)
 187 {
 188         int alen;
 189         int i, j;
 190
 191         if (a == NULL)
 192                 return;
 193
 194         alen = int_array_len(a);
 195         qsort(a, alen, sizeof(int), freq_cmp);
 196
 197         i = 0;
 198         j = 1;
 199         while (a[i] && a[j]) {
 200                 if (a[i] == a[j]) {
 201                         j++;
 202                         continue;
 203                 }
 204                 a[++i] = a[j++];
 205         }
 206         if (a[i])
 207                 i++;
 208         a[i] = 0;
 209 }
 210
 211
 212 /**
 213  * wpa_supplicant_trigger_scan - Request driver to start a scan
 214  * @wpa_s: Pointer to wpa_supplicant data
 215  * @params: Scan parameters
 216  * Returns: 0 on success, -1 on failure
 217  */
 218 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 219                                 struct wpa_driver_scan_params *params)
 220 {
 221         int ret;
 222
 223         wpa_supplicant_notify_scanning(wpa_s, 1);
 224
 225         ret = wpa_drv_scan(wpa_s, params);
 226         if (ret) {
 227                 wpa_supplicant_notify_scanning(wpa_s, 0);
 228                 wpas_notify_scan_done(wpa_s, 0);
 229         } else {
 230                 os_get_time(&wpa_s->scan_trigger_time);
 231                 wpa_s->scan_runs++;
 232                 wpa_s->normal_scans++;
 233         }
 234
 235         return ret;
 236 }
 237
 238
 239 static void
 240 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 241 {
 242         struct wpa_supplicant *wpa_s = eloop_ctx;
 243
 244         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 245
 246         if (wpa_supplicant_req_sched_scan(wpa_s))
 247                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 248 }
 249
 250
 251 static void
 252 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 253 {
 254         struct wpa_supplicant *wpa_s = eloop_ctx;
 255
 256         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 257
 258         wpa_s->sched_scan_timed_out = 1;
 259         wpa_supplicant_cancel_sched_scan(wpa_s);
 260 }
 261
 262
 263 static int
 264 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 static 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  * Find the operating frequency of any other virtual interface that is using
 488  * the same radio concurrently.
 489  */
 490 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
 491 {
 492         const char *rn, *rn2;
 493         struct wpa_supplicant *ifs;
 494         u8 bssid[ETH_ALEN];
 495
 496         if (!wpa_s->driver->get_radio_name)
 497                 return -1;
 498
 499         rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
 500         if (rn == NULL || rn[0] == '\0')
 501                 return -1;
 502
 503         for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
 504                 if (ifs == wpa_s || !ifs->driver->get_radio_name)
 505                         continue;
 506
 507                 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
 508                 if (!rn2 || os_strcmp(rn, rn2) != 0)
 509                         continue;
 510
 511                 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
 512                         continue;
 513
 514                 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
 515                     ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
 516                         return ifs->current_ssid->frequency;
 517                 if (wpa_drv_get_bssid(ifs, bssid) == 0)
 518                         return ifs->assoc_freq;
 519         }
 520
 521         return 0;
 522 }
 523
 524
 525 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 526 {
 527         struct wpa_supplicant *wpa_s = eloop_ctx;
 528         struct wpa_ssid *ssid;
 529         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 530         int ret;
 531         struct wpabuf *extra_ie = NULL;
 532         struct wpa_driver_scan_params params;
 533         struct wpa_driver_scan_params *scan_params;
 534         size_t max_ssids;
 535         enum wpa_states prev_state;
 536
 537         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 538                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 539                 wpas_p2p_continue_after_scan(wpa_s);
 540                 return;
 541         }
 542
 543         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 544                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 545                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 546                 wpas_p2p_continue_after_scan(wpa_s);
 547                 return;
 548         }
 549
 550         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 551             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 552                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 553                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 554                 wpas_p2p_continue_after_scan(wpa_s);
 555                 return;
 556         }
 557
 558         if (wpa_s->conf->ap_scan != 0 &&
 559             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 560                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 561                         "overriding ap_scan configuration");
 562                 wpa_s->conf->ap_scan = 0;
 563                 wpas_notify_ap_scan_changed(wpa_s);
 564         }
 565
 566         if (wpa_s->conf->ap_scan == 0) {
 567                 wpa_supplicant_gen_assoc_event(wpa_s);
 568                 return;
 569         }
 570
 571 #ifdef CONFIG_P2P
 572         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s)) {
 573                 if (wpa_s->sta_scan_pending &&
 574                     wpas_p2p_in_progress(wpa_s) == 2 &&
 575                     wpa_s->global->p2p_cb_on_scan_complete) {
 576                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 577                                 "mode scan during P2P search");
 578                 } else {
 579                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 580                                 "while P2P operation is in progress");
 581                         wpa_s->sta_scan_pending = 1;
 582                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 583                         return;
 584                 }
 585         }
 586 #endif /* CONFIG_P2P */
 587
 588         if (wpa_s->conf->ap_scan == 2)
 589                 max_ssids = 1;
 590         else {
 591                 max_ssids = wpa_s->max_scan_ssids;
 592                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 593                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 594         }
 595
 596         scan_req = wpa_s->scan_req;
 597         wpa_s->scan_req = NORMAL_SCAN_REQ;
 598
 599         os_memset(&params, 0, sizeof(params));
 600
 601         prev_state = wpa_s->wpa_state;
 602         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 603             wpa_s->wpa_state == WPA_INACTIVE)
 604                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 605
 606         /*
 607          * If autoscan has set its own scanning parameters
 608          */
 609         if (wpa_s->autoscan_params != NULL) {
 610                 scan_params = wpa_s->autoscan_params;
 611                 goto scan;
 612         }
 613
 614         if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
 615                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 616                         if (ssid == wpa_s->connect_without_scan)
 617                                 break;
 618                 }
 619                 wpa_s->connect_without_scan = NULL;
 620                 if (ssid) {
 621                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 622                                    "without scan step");
 623                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 624                         return;
 625                 }
 626         }
 627
 628 #ifdef CONFIG_P2P
 629         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 630             wpa_s->go_params) {
 631                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 632                            "P2P group formation");
 633                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 634                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 635                 params.num_ssids = 1;
 636                 goto ssid_list_set;
 637         }
 638 #endif /* CONFIG_P2P */
 639
 640         /* Find the starting point from which to continue scanning */
 641         ssid = wpa_s->conf->ssid;
 642         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 643                 while (ssid) {
 644                         if (ssid == wpa_s->prev_scan_ssid) {
 645                                 ssid = ssid->next;
 646                                 break;
 647                         }
 648                         ssid = ssid->next;
 649                 }
 650         }
 651
 652         if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 653                 wpa_s->connect_without_scan = NULL;
 654                 wpa_s->prev_scan_wildcard = 0;
 655                 wpa_supplicant_assoc_try(wpa_s, ssid);
 656                 return;
 657         } else if (wpa_s->conf->ap_scan == 2) {
 658                 /*
 659                  * User-initiated scan request in ap_scan == 2; scan with
 660                  * wildcard SSID.
 661                  */
 662                 ssid = NULL;
 663         } else {
 664                 struct wpa_ssid *start = ssid, *tssid;
 665                 int freqs_set = 0;
 666                 if (ssid == NULL && max_ssids > 1)
 667                         ssid = wpa_s->conf->ssid;
 668                 while (ssid) {
 669                         if (!wpas_network_disabled(wpa_s, ssid) &&
 670                             ssid->scan_ssid) {
 671                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 672                                                   ssid->ssid, ssid->ssid_len);
 673                                 params.ssids[params.num_ssids].ssid =
 674                                         ssid->ssid;
 675                                 params.ssids[params.num_ssids].ssid_len =
 676                                         ssid->ssid_len;
 677                                 params.num_ssids++;
 678                                 if (params.num_ssids + 1 >= max_ssids)
 679                                         break;
 680                         }
 681                         ssid = ssid->next;
 682                         if (ssid == start)
 683                                 break;
 684                         if (ssid == NULL && max_ssids > 1 &&
 685                             start != wpa_s->conf->ssid)
 686                                 ssid = wpa_s->conf->ssid;
 687                 }
 688
 689                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 690                         if (wpas_network_disabled(wpa_s, tssid))
 691                                 continue;
 692                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 693                                 int_array_concat(&params.freqs,
 694                                                  tssid->scan_freq);
 695                         } else {
 696                                 os_free(params.freqs);
 697                                 params.freqs = NULL;
 698                         }
 699                         freqs_set = 1;
 700                 }
 701                 int_array_sort_unique(params.freqs);
 702         }
 703
 704         if (ssid && max_ssids == 1) {
 705                 /*
 706                  * If the driver is limited to 1 SSID at a time interleave
 707                  * wildcard SSID scans with specific SSID scans to avoid
 708                  * waiting a long time for a wildcard scan.
 709                  */
 710                 if (!wpa_s->prev_scan_wildcard) {
 711                         params.ssids[0].ssid = NULL;
 712                         params.ssids[0].ssid_len = 0;
 713                         wpa_s->prev_scan_wildcard = 1;
 714                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 715                                 "wildcard SSID (Interleave with specific)");
 716                 } else {
 717                         wpa_s->prev_scan_ssid = ssid;
 718                         wpa_s->prev_scan_wildcard = 0;
 719                         wpa_dbg(wpa_s, MSG_DEBUG,
 720                                 "Starting AP scan for specific SSID: %s",
 721                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 722                 }
 723         } else if (ssid) {
 724                 /* max_ssids > 1 */
 725
 726                 wpa_s->prev_scan_ssid = ssid;
 727                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 728                         "the scan request");
 729                 params.num_ssids++;
 730         } else {
 731                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 732                 params.num_ssids++;
 733                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 734                         "SSID");
 735         }
 736 #ifdef CONFIG_P2P
 737 ssid_list_set:
 738 #endif /* CONFIG_P2P */
 739
 740         wpa_supplicant_optimize_freqs(wpa_s, &params);
 741         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 742
 743         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 744                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 745                         "generated frequency list");
 746                 params.freqs = wpa_s->next_scan_freqs;
 747         } else
 748                 os_free(wpa_s->next_scan_freqs);
 749         wpa_s->next_scan_freqs = NULL;
 750
 751         /* See if user specified frequencies. If so, scan only those. */
 752         if (wpa_s->conf->freq_list && !params.freqs) {
 753                 wpa_dbg(wpa_s, MSG_DEBUG,
 754                         "Optimize scan based on conf->freq_list");
 755                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 756         }
 757
 758         /* Use current associated channel? */
 759         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 760                 int freq = shared_vif_oper_freq(wpa_s);
 761                 if (freq > 0) {
 762                         wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current "
 763                                 "operating channel (%d MHz) since "
 764                                 "scan_cur_freq is enabled", freq);
 765                         params.freqs = os_zalloc(sizeof(int) * 2);
 766                         if (params.freqs)
 767                                 params.freqs[0] = freq;
 768                 }
 769         }
 770
 771         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 772                 wpa_s->conf, &params.num_filter_ssids);
 773         if (extra_ie) {
 774                 params.extra_ies = wpabuf_head(extra_ie);
 775                 params.extra_ies_len = wpabuf_len(extra_ie);
 776         }
 777
 778 #ifdef CONFIG_P2P
 779         if (wpa_s->p2p_in_provisioning ||
 780             (wpa_s->show_group_started && wpa_s->go_params)) {
 781                 /*
 782                  * The interface may not yet be in P2P mode, so we have to
 783                  * explicitly request P2P probe to disable CCK rates.
 784                  */
 785                 params.p2p_probe = 1;
 786         }
 787 #endif /* CONFIG_P2P */
 788
 789         scan_params = &params;
 790
 791 scan:
 792 #ifdef CONFIG_P2P
 793         /*
 794          * If the driver does not support multi-channel concurrency and a
 795          * virtual interface that shares the same radio with the wpa_s interface
 796          * is operating there may not be need to scan other channels apart from
 797          * the current operating channel on the other virtual interface. Filter
 798          * out other channels in case we are trying to find a connection for a
 799          * station interface when we are not configured to prefer station
 800          * connection and a concurrent operation is already in process.
 801          */
 802         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 803             !scan_params->freqs && !params.freqs &&
 804             wpas_is_p2p_prioritized(wpa_s) &&
 805             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
 806             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 807             non_p2p_network_enabled(wpa_s)) {
 808                 int freq = shared_vif_oper_freq(wpa_s);
 809                 if (freq > 0) {
 810                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
 811                                 "operating channel (%d MHz) since driver does "
 812                                 "not support multi-channel concurrency", freq);
 813                         params.freqs = os_zalloc(sizeof(int) * 2);
 814                         if (params.freqs)
 815                                 params.freqs[0] = freq;
 816                         scan_params->freqs = params.freqs;
 817                 }
 818         }
 819 #endif /* CONFIG_P2P */
 820
 821         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 822
 823         wpabuf_free(extra_ie);
 824         os_free(params.freqs);
 825         os_free(params.filter_ssids);
 826
 827         if (ret) {
 828                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 829                 if (prev_state != wpa_s->wpa_state)
 830                         wpa_supplicant_set_state(wpa_s, prev_state);
 831                 /* Restore scan_req since we will try to scan again */
 832                 wpa_s->scan_req = scan_req;
 833                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 834         } else {
 835                 wpa_s->scan_for_connection = 0;
 836         }
 837 }
 838
 839
 840 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 841 {
 842         struct os_time remaining, new_int;
 843         int cancelled;
 844
 845         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 846                                              &remaining);
 847
 848         new_int.sec = sec;
 849         new_int.usec = 0;
 850         if (cancelled && os_time_before(&remaining, &new_int)) {
 851                 new_int.sec = remaining.sec;
 852                 new_int.usec = remaining.usec;
 853         }
 854
 855         eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
 856                                wpa_s, NULL);
 857         wpa_s->scan_interval = sec;
 858 }
 859
 860
 861 /**
 862  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 863  * @wpa_s: Pointer to wpa_supplicant data
 864  * @sec: Number of seconds after which to scan
 865  * @usec: Number of microseconds after which to scan
 866  *
 867  * This function is used to schedule a scan for neighboring access points after
 868  * the specified time.
 869  */
 870 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 871 {
 872         /* If there's at least one network that should be specifically scanned
 873          * then don't cancel the scan and reschedule.  Some drivers do
 874          * background scanning which generates frequent scan results, and that
 875          * causes the specific SSID scan to get continually pushed back and
 876          * never happen, which causes hidden APs to never get probe-scanned.
 877          */
 878         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 879             wpa_s->conf->ap_scan == 1) {
 880                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 881
 882                 while (ssid) {
 883                         if (!wpas_network_disabled(wpa_s, ssid) &&
 884                             ssid->scan_ssid)
 885                                 break;
 886                         ssid = ssid->next;
 887                 }
 888                 if (ssid) {
 889                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 890                                 "ensure that specific SSID scans occur");
 891                         return;
 892                 }
 893         }
 894
 895         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 896                 sec, usec);
 897         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 898         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 899 }
 900
 901
 902 /**
 903  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 904  * @wpa_s: Pointer to wpa_supplicant data
 905  * @sec: Number of seconds after which to scan
 906  * @usec: Number of microseconds after which to scan
 907  * Returns: 0 on success or -1 otherwise
 908  *
 909  * This function is used to schedule periodic scans for neighboring
 910  * access points after the specified time.
 911  */
 912 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 913                                       int sec, int usec)
 914 {
 915         if (!wpa_s->sched_scan_supported)
 916                 return -1;
 917
 918         eloop_register_timeout(sec, usec,
 919                                wpa_supplicant_delayed_sched_scan_timeout,
 920                                wpa_s, NULL);
 921
 922         return 0;
 923 }
 924
 925
 926 /**
 927  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 928  * @wpa_s: Pointer to wpa_supplicant data
 929  * Returns: 0 is sched_scan was started or -1 otherwise
 930  *
 931  * This function is used to schedule periodic scans for neighboring
 932  * access points repeating the scan continuously.
 933  */
 934 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 935 {
 936         struct wpa_driver_scan_params params;
 937         struct wpa_driver_scan_params *scan_params;
 938         enum wpa_states prev_state;
 939         struct wpa_ssid *ssid = NULL;
 940         struct wpabuf *extra_ie = NULL;
 941         int ret;
 942         unsigned int max_sched_scan_ssids;
 943         int wildcard = 0;
 944         int need_ssids;
 945
 946         if (!wpa_s->sched_scan_supported)
 947                 return -1;
 948
 949         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 950                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 951         else
 952                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 953         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 954                 return -1;
 955
 956         if (wpa_s->sched_scanning) {
 957                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 958                 return 0;
 959         }
 960
 961         need_ssids = 0;
 962         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 963                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 964                         /* Use wildcard SSID to find this network */
 965                         wildcard = 1;
 966                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 967                            ssid->ssid_len)
 968                         need_ssids++;
 969
 970 #ifdef CONFIG_WPS
 971                 if (!wpas_network_disabled(wpa_s, ssid) &&
 972                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 973                         /*
 974                          * Normal scan is more reliable and faster for WPS
 975                          * operations and since these are for short periods of
 976                          * time, the benefit of trying to use sched_scan would
 977                          * be limited.
 978                          */
 979                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 980                                 "sched_scan for WPS");
 981                         return -1;
 982                 }
 983 #endif /* CONFIG_WPS */
 984         }
 985         if (wildcard)
 986                 need_ssids++;
 987
 988         if (wpa_s->normal_scans < 3 &&
 989             (need_ssids <= wpa_s->max_scan_ssids ||
 990              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 991                 /*
 992                  * When normal scan can speed up operations, use that for the
 993                  * first operations before starting the sched_scan to allow
 994                  * user space sleep more. We do this only if the normal scan
 995                  * has functionality that is suitable for this or if the
 996                  * sched_scan does not have better support for multiple SSIDs.
 997                  */
 998                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 999                         "sched_scan for initial scans (normal_scans=%d)",
1000                         wpa_s->normal_scans);
1001                 return -1;
1002         }
1003
1004         os_memset(&params, 0, sizeof(params));
1005
1006         /* If we can't allocate space for the filters, we just don't filter */
1007         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1008                                         sizeof(struct wpa_driver_scan_filter));
1009
1010         prev_state = wpa_s->wpa_state;
1011         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1012             wpa_s->wpa_state == WPA_INACTIVE)
1013                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1014
1015         if (wpa_s->autoscan_params != NULL) {
1016                 scan_params = wpa_s->autoscan_params;
1017                 goto scan;
1018         }
1019
1020         /* Find the starting point from which to continue scanning */
1021         ssid = wpa_s->conf->ssid;
1022         if (wpa_s->prev_sched_ssid) {
1023                 while (ssid) {
1024                         if (ssid == wpa_s->prev_sched_ssid) {
1025                                 ssid = ssid->next;
1026                                 break;
1027                         }
1028                         ssid = ssid->next;
1029                 }
1030         }
1031
1032         if (!ssid || !wpa_s->prev_sched_ssid) {
1033                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1034                 if (wpa_s->conf->sched_scan_interval)
1035                         wpa_s->sched_scan_interval =
1036                                 wpa_s->conf->sched_scan_interval;
1037                 if (wpa_s->sched_scan_interval == 0)
1038                         wpa_s->sched_scan_interval = 10;
1039                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1040                 wpa_s->first_sched_scan = 1;
1041                 ssid = wpa_s->conf->ssid;
1042                 wpa_s->prev_sched_ssid = ssid;
1043         }
1044
1045         if (wildcard) {
1046                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1047                 params.num_ssids++;
1048         }
1049
1050         while (ssid) {
1051                 if (wpas_network_disabled(wpa_s, ssid))
1052                         goto next;
1053
1054                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1055                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1056                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1057                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1058                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1059                                   ssid->ssid, ssid->ssid_len);
1060                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1061                                 ssid->ssid_len;
1062                         params.num_filter_ssids++;
1063                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1064                 {
1065                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1066                                 "filter for sched_scan - drop filter");
1067                         os_free(params.filter_ssids);
1068                         params.filter_ssids = NULL;
1069                         params.num_filter_ssids = 0;
1070                 }
1071
1072                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1073                         if (params.num_ssids == max_sched_scan_ssids)
1074                                 break; /* only room for broadcast SSID */
1075                         wpa_dbg(wpa_s, MSG_DEBUG,
1076                                 "add to active scan ssid: %s",
1077                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1078                         params.ssids[params.num_ssids].ssid =
1079                                 ssid->ssid;
1080                         params.ssids[params.num_ssids].ssid_len =
1081                                 ssid->ssid_len;
1082                         params.num_ssids++;
1083                         if (params.num_ssids >= max_sched_scan_ssids) {
1084                                 wpa_s->prev_sched_ssid = ssid;
1085                                 do {
1086                                         ssid = ssid->next;
1087                                 } while (ssid &&
1088                                          (wpas_network_disabled(wpa_s, ssid) ||
1089                                           !ssid->scan_ssid));
1090                                 break;
1091                         }
1092                 }
1093
1094         next:
1095                 wpa_s->prev_sched_ssid = ssid;
1096                 ssid = ssid->next;
1097         }
1098
1099         if (params.num_filter_ssids == 0) {
1100                 os_free(params.filter_ssids);
1101                 params.filter_ssids = NULL;
1102         }
1103
1104         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1105         if (extra_ie) {
1106                 params.extra_ies = wpabuf_head(extra_ie);
1107                 params.extra_ies_len = wpabuf_len(extra_ie);
1108         }
1109
1110         scan_params = &params;
1111
1112 scan:
1113         if (ssid || !wpa_s->first_sched_scan) {
1114                 wpa_dbg(wpa_s, MSG_DEBUG,
1115                         "Starting sched scan: interval %d timeout %d",
1116                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1117         } else {
1118                 wpa_dbg(wpa_s, MSG_DEBUG,
1119                         "Starting sched scan: interval %d (no timeout)",
1120                         wpa_s->sched_scan_interval);
1121         }
1122
1123         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1124                                               wpa_s->sched_scan_interval);
1125         wpabuf_free(extra_ie);
1126         os_free(params.filter_ssids);
1127         if (ret) {
1128                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1129                 if (prev_state != wpa_s->wpa_state)
1130                         wpa_supplicant_set_state(wpa_s, prev_state);
1131                 return ret;
1132         }
1133
1134         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1135         if (ssid || !wpa_s->first_sched_scan) {
1136                 wpa_s->sched_scan_timed_out = 0;
1137                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1138                                        wpa_supplicant_sched_scan_timeout,
1139                                        wpa_s, NULL);
1140                 wpa_s->first_sched_scan = 0;
1141                 wpa_s->sched_scan_timeout /= 2;
1142                 wpa_s->sched_scan_interval *= 2;
1143                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1144                         wpa_s->sched_scan_interval = 10;
1145                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1146                 }
1147         }
1148
1149         /* If there is no more ssids, start next time from the beginning */
1150         if (!ssid)
1151                 wpa_s->prev_sched_ssid = NULL;
1152
1153         return 0;
1154 }
1155
1156
1157 /**
1158  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1159  * @wpa_s: Pointer to wpa_supplicant data
1160  *
1161  * This function is used to cancel a scan request scheduled with
1162  * wpa_supplicant_req_scan().
1163  */
1164 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1165 {
1166         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1167         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1168         wpas_p2p_continue_after_scan(wpa_s);
1169 }
1170
1171
1172 /**
1173  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1174  * @wpa_s: Pointer to wpa_supplicant data
1175  *
1176  * This function is used to stop a periodic scheduled scan.
1177  */
1178 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1179 {
1180         if (!wpa_s->sched_scanning)
1181                 return;
1182
1183         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1184         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1185         wpa_supplicant_stop_sched_scan(wpa_s);
1186 }
1187
1188
1189 /**
1190  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1191  * @wpa_s: Pointer to wpa_supplicant data
1192  * @scanning: Whether scanning is currently in progress
1193  *
1194  * This function is to generate scanning notifycations. It is called whenever
1195  * there may have been a change in scanning (scan started, completed, stopped).
1196  * wpas_notify_scanning() is called whenever the scanning state changed from the
1197  * previously notified state.
1198  */
1199 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1200                                     int scanning)
1201 {
1202         if (wpa_s->scanning != scanning) {
1203                 wpa_s->scanning = scanning;
1204                 wpas_notify_scanning(wpa_s);
1205         }
1206 }
1207
1208
1209 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1210 {
1211         int rate = 0;
1212         const u8 *ie;
1213         int i;
1214
1215         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1216         for (i = 0; ie && i < ie[1]; i++) {
1217                 if ((ie[i + 2] & 0x7f) > rate)
1218                         rate = ie[i + 2] & 0x7f;
1219         }
1220
1221         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1222         for (i = 0; ie && i < ie[1]; i++) {
1223                 if ((ie[i + 2] & 0x7f) > rate)
1224                         rate = ie[i + 2] & 0x7f;
1225         }
1226
1227         return rate;
1228 }
1229
1230
1231 /**
1232  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1233  * @res: Scan result entry
1234  * @ie: Information element identitifier (WLAN_EID_*)
1235  * Returns: Pointer to the information element (id field) or %NULL if not found
1236  *
1237  * This function returns the first matching information element in the scan
1238  * result.
1239  */
1240 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1241 {
1242         const u8 *end, *pos;
1243
1244         pos = (const u8 *) (res + 1);
1245         end = pos + res->ie_len;
1246
1247         while (pos + 1 < end) {
1248                 if (pos + 2 + pos[1] > end)
1249                         break;
1250                 if (pos[0] == ie)
1251                         return pos;
1252                 pos += 2 + pos[1];
1253         }
1254
1255         return NULL;
1256 }
1257
1258
1259 /**
1260  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1261  * @res: Scan result entry
1262  * @vendor_type: Vendor type (four octets starting the IE payload)
1263  * Returns: Pointer to the information element (id field) or %NULL if not found
1264  *
1265  * This function returns the first matching information element in the scan
1266  * result.
1267  */
1268 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1269                                   u32 vendor_type)
1270 {
1271         const u8 *end, *pos;
1272
1273         pos = (const u8 *) (res + 1);
1274         end = pos + res->ie_len;
1275
1276         while (pos + 1 < end) {
1277                 if (pos + 2 + pos[1] > end)
1278                         break;
1279                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1280                     vendor_type == WPA_GET_BE32(&pos[2]))
1281                         return pos;
1282                 pos += 2 + pos[1];
1283         }
1284
1285         return NULL;
1286 }
1287
1288
1289 /**
1290  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1291  * @res: Scan result entry
1292  * @vendor_type: Vendor type (four octets starting the IE payload)
1293  * Returns: Pointer to the information element payload or %NULL if not found
1294  *
1295  * This function returns concatenated payload of possibly fragmented vendor
1296  * specific information elements in the scan result. The caller is responsible
1297  * for freeing the returned buffer.
1298  */
1299 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1300                                              u32 vendor_type)
1301 {
1302         struct wpabuf *buf;
1303         const u8 *end, *pos;
1304
1305         buf = wpabuf_alloc(res->ie_len);
1306         if (buf == NULL)
1307                 return NULL;
1308
1309         pos = (const u8 *) (res + 1);
1310         end = pos + res->ie_len;
1311
1312         while (pos + 1 < end) {
1313                 if (pos + 2 + pos[1] > end)
1314                         break;
1315                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1316                     vendor_type == WPA_GET_BE32(&pos[2]))
1317                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1318                 pos += 2 + pos[1];
1319         }
1320
1321         if (wpabuf_len(buf) == 0) {
1322                 wpabuf_free(buf);
1323                 buf = NULL;
1324         }
1325
1326         return buf;
1327 }
1328
1329
1330 /*
1331  * Channels with a great SNR can operate at full rate. What is a great SNR?
1332  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1333  * rule of thumb is that any SNR above 20 is good." This one
1334  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1335  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1336  * conservative value.
1337  */
1338 #define GREAT_SNR 30
1339
1340 /* Compare function for sorting scan results. Return >0 if @b is considered
1341  * better. */
1342 static int wpa_scan_result_compar(const void *a, const void *b)
1343 {
1344 #define IS_5GHZ(n) (n > 4000)
1345 #define MIN(a,b) a < b ? a : b
1346         struct wpa_scan_res **_wa = (void *) a;
1347         struct wpa_scan_res **_wb = (void *) b;
1348         struct wpa_scan_res *wa = *_wa;
1349         struct wpa_scan_res *wb = *_wb;
1350         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1351         int snr_a, snr_b;
1352
1353         /* WPA/WPA2 support preferred */
1354         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1355                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1356         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1357                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1358
1359         if (wpa_b && !wpa_a)
1360                 return 1;
1361         if (!wpa_b && wpa_a)
1362                 return -1;
1363
1364         /* privacy support preferred */
1365         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1366             (wb->caps & IEEE80211_CAP_PRIVACY))
1367                 return 1;
1368         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1369             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1370                 return -1;
1371
1372         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1373             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1374                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1375                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1376         } else {
1377                 /* Not suitable information to calculate SNR, so use level */
1378                 snr_a = wa->level;
1379                 snr_b = wb->level;
1380         }
1381
1382         /* best/max rate preferred if SNR close enough */
1383         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1384             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1385                 maxrate_a = wpa_scan_get_max_rate(wa);
1386                 maxrate_b = wpa_scan_get_max_rate(wb);
1387                 if (maxrate_a != maxrate_b)
1388                         return maxrate_b - maxrate_a;
1389                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1390                         return IS_5GHZ(wa->freq) ? -1 : 1;
1391         }
1392
1393         /* use freq for channel preference */
1394
1395         /* all things being equal, use SNR; if SNRs are
1396          * identical, use quality values since some drivers may only report
1397          * that value and leave the signal level zero */
1398         if (snr_b == snr_a)
1399                 return wb->qual - wa->qual;
1400         return snr_b - snr_a;
1401 #undef MIN
1402 #undef IS_5GHZ
1403 }
1404
1405
1406 #ifdef CONFIG_WPS
1407 /* Compare function for sorting scan results when searching a WPS AP for
1408  * provisioning. Return >0 if @b is considered better. */
1409 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1410 {
1411         struct wpa_scan_res **_wa = (void *) a;
1412         struct wpa_scan_res **_wb = (void *) b;
1413         struct wpa_scan_res *wa = *_wa;
1414         struct wpa_scan_res *wb = *_wb;
1415         int uses_wps_a, uses_wps_b;
1416         struct wpabuf *wps_a, *wps_b;
1417         int res;
1418
1419         /* Optimization - check WPS IE existence before allocated memory and
1420          * doing full reassembly. */
1421         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1422         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1423         if (uses_wps_a && !uses_wps_b)
1424                 return -1;
1425         if (!uses_wps_a && uses_wps_b)
1426                 return 1;
1427
1428         if (uses_wps_a && uses_wps_b) {
1429                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1430                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1431                 res = wps_ap_priority_compar(wps_a, wps_b);
1432                 wpabuf_free(wps_a);
1433                 wpabuf_free(wps_b);
1434                 if (res)
1435                         return res;
1436         }
1437
1438         /*
1439          * Do not use current AP security policy as a sorting criteria during
1440          * WPS provisioning step since the AP may get reconfigured at the
1441          * completion of provisioning.
1442          */
1443
1444         /* all things being equal, use signal level; if signal levels are
1445          * identical, use quality values since some drivers may only report
1446          * that value and leave the signal level zero */
1447         if (wb->level == wa->level)
1448                 return wb->qual - wa->qual;
1449         return wb->level - wa->level;
1450 }
1451 #endif /* CONFIG_WPS */
1452
1453
1454 static void dump_scan_res(struct wpa_scan_results *scan_res)
1455 {
1456 #ifndef CONFIG_NO_STDOUT_DEBUG
1457         size_t i;
1458
1459         if (scan_res->res == NULL || scan_res->num == 0)
1460                 return;
1461
1462         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1463
1464         for (i = 0; i < scan_res->num; i++) {
1465                 struct wpa_scan_res *r = scan_res->res[i];
1466                 u8 *pos;
1467                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1468                     == WPA_SCAN_LEVEL_DBM) {
1469                         int snr = r->level - r->noise;
1470                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1471                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1472                                    "age=%u",
1473                                    MAC2STR(r->bssid), r->freq, r->qual,
1474                                    r->noise, r->level, snr,
1475                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1476                                    r->age);
1477                 } else {
1478                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1479                                    "noise=%d level=%d flags=0x%x age=%u",
1480                                    MAC2STR(r->bssid), r->freq, r->qual,
1481                                    r->noise, r->level, r->flags, r->age);
1482                 }
1483                 pos = (u8 *) (r + 1);
1484                 if (r->ie_len)
1485                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1486                 pos += r->ie_len;
1487                 if (r->beacon_ie_len)
1488                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1489                                     pos, r->beacon_ie_len);
1490         }
1491 #endif /* CONFIG_NO_STDOUT_DEBUG */
1492 }
1493
1494
1495 /**
1496  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1497  * @wpa_s: Pointer to wpa_supplicant data
1498  * @bssid: BSSID to check
1499  * Returns: 0 if the BSSID is filtered or 1 if not
1500  *
1501  * This function is used to filter out specific BSSIDs from scan reslts mainly
1502  * for testing purposes (SET bssid_filter ctrl_iface command).
1503  */
1504 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1505                                       const u8 *bssid)
1506 {
1507         size_t i;
1508
1509         if (wpa_s->bssid_filter == NULL)
1510                 return 1;
1511
1512         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1513                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1514                               ETH_ALEN) == 0)
1515                         return 1;
1516         }
1517
1518         return 0;
1519 }
1520
1521
1522 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1523                             struct wpa_scan_results *res)
1524 {
1525         size_t i, j;
1526
1527         if (wpa_s->bssid_filter == NULL)
1528                 return;
1529
1530         for (i = 0, j = 0; i < res->num; i++) {
1531                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1532                                                       res->res[i]->bssid)) {
1533                         res->res[j++] = res->res[i];
1534                 } else {
1535                         os_free(res->res[i]);
1536                         res->res[i] = NULL;
1537                 }
1538         }
1539
1540         if (res->num != j) {
1541                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1542                            (int) (res->num - j));
1543                 res->num = j;
1544         }
1545 }
1546
1547
1548 /**
1549  * wpa_supplicant_get_scan_results - Get scan results
1550  * @wpa_s: Pointer to wpa_supplicant data
1551  * @info: Information about what was scanned or %NULL if not available
1552  * @new_scan: Whether a new scan was performed
1553  * Returns: Scan results, %NULL on failure
1554  *
1555  * This function request the current scan results from the driver and updates
1556  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1557  * results with wpa_scan_results_free().
1558  */
1559 struct wpa_scan_results *
1560 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1561                                 struct scan_info *info, int new_scan)
1562 {
1563         struct wpa_scan_results *scan_res;
1564         size_t i;
1565         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1566
1567         scan_res = wpa_drv_get_scan_results2(wpa_s);
1568         if (scan_res == NULL) {
1569                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1570                 return NULL;
1571         }
1572         if (scan_res->fetch_time.sec == 0) {
1573                 /*
1574                  * Make sure we have a valid timestamp if the driver wrapper
1575                  * does not set this.
1576                  */
1577                 os_get_time(&scan_res->fetch_time);
1578         }
1579         filter_scan_res(wpa_s, scan_res);
1580
1581 #ifdef CONFIG_WPS
1582         if (wpas_wps_in_progress(wpa_s)) {
1583                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1584                         "provisioning rules");
1585                 compar = wpa_scan_result_wps_compar;
1586         }
1587 #endif /* CONFIG_WPS */
1588
1589         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1590               compar);
1591         dump_scan_res(scan_res);
1592
1593         wpa_bss_update_start(wpa_s);
1594         for (i = 0; i < scan_res->num; i++)
1595                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1596                                         &scan_res->fetch_time);
1597         wpa_bss_update_end(wpa_s, info, new_scan);
1598
1599         return scan_res;
1600 }
1601
1602
1603 /**
1604  * wpa_supplicant_update_scan_results - Update scan results from the driver
1605  * @wpa_s: Pointer to wpa_supplicant data
1606  * Returns: 0 on success, -1 on failure
1607  *
1608  * This function updates the BSS table within wpa_supplicant based on the
1609  * currently available scan results from the driver without requesting a new
1610  * scan. This is used in cases where the driver indicates an association
1611  * (including roaming within ESS) and wpa_supplicant does not yet have the
1612  * needed information to complete the connection (e.g., to perform validation
1613  * steps in 4-way handshake).
1614  */
1615 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1616 {
1617         struct wpa_scan_results *scan_res;
1618         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1619         if (scan_res == NULL)
1620                 return -1;
1621         wpa_scan_results_free(scan_res);
1622
1623         return 0;
1624 }
1625
1626
1627 /**
1628  * scan_only_handler - Reports scan results
1629  */
1630 void scan_only_handler(struct wpa_supplicant *wpa_s,
1631                        struct wpa_scan_results *scan_res)
1632 {
1633         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1634         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1635         wpas_notify_scan_results(wpa_s);
1636         wpas_notify_scan_done(wpa_s, 1);
1637 }
1638
1639
1640 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1641 {
1642         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1643 }