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 static int
 265 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 266                                 struct wpa_driver_scan_params *params,
 267                                 int interval)
 268 {
 269         int ret;
 270
 271         wpa_supplicant_notify_scanning(wpa_s, 1);
 272         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 273         if (ret)
 274                 wpa_supplicant_notify_scanning(wpa_s, 0);
 275         else
 276                 wpa_s->sched_scanning = 1;
 277
 278         return ret;
 279 }
 280
 281
 282 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 283 {
 284         int ret;
 285
 286         ret = wpa_drv_stop_sched_scan(wpa_s);
 287         if (ret) {
 288                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 289                 /* TODO: what to do if stopping fails? */
 290                 return -1;
 291         }
 292
 293         return ret;
 294 }
 295
 296
 297 static struct wpa_driver_scan_filter *
 298 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 299 {
 300         struct wpa_driver_scan_filter *ssids;
 301         struct wpa_ssid *ssid;
 302         size_t count;
 303
 304         *num_ssids = 0;
 305         if (!conf->filter_ssids)
 306                 return NULL;
 307
 308         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 309                 if (ssid->ssid && ssid->ssid_len)
 310                         count++;
 311         }
 312         if (count == 0)
 313                 return NULL;
 314         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 315         if (ssids == NULL)
 316                 return NULL;
 317
 318         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 319                 if (!ssid->ssid || !ssid->ssid_len)
 320                         continue;
 321                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 322                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 323                 (*num_ssids)++;
 324         }
 325
 326         return ssids;
 327 }
 328
 329
 330 static void wpa_supplicant_optimize_freqs(
 331         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 332 {
 333 #ifdef CONFIG_P2P
 334         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 335             wpa_s->go_params) {
 336                 /* Optimize provisioning state scan based on GO information */
 337                 if (wpa_s->p2p_in_provisioning < 5 &&
 338                     wpa_s->go_params->freq > 0) {
 339                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 340                                 "preferred frequency %d MHz",
 341                                 wpa_s->go_params->freq);
 342                         params->freqs = os_zalloc(2 * sizeof(int));
 343                         if (params->freqs)
 344                                 params->freqs[0] = wpa_s->go_params->freq;
 345                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 346                            wpa_s->go_params->freq_list[0]) {
 347                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 348                                 "channels");
 349                         int_array_concat(&params->freqs,
 350                                          wpa_s->go_params->freq_list);
 351                         if (params->freqs)
 352                                 int_array_sort_unique(params->freqs);
 353                 }
 354                 wpa_s->p2p_in_provisioning++;
 355         }
 356 #endif /* CONFIG_P2P */
 357
 358 #ifdef CONFIG_WPS
 359         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 360                 /*
 361                  * Optimize post-provisioning scan based on channel used
 362                  * during provisioning.
 363                  */
 364                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 365                         "that was used during provisioning", wpa_s->wps_freq);
 366                 params->freqs = os_zalloc(2 * sizeof(int));
 367                 if (params->freqs)
 368                         params->freqs[0] = wpa_s->wps_freq;
 369                 wpa_s->after_wps--;
 370         }
 371
 372         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 373         {
 374                 /* Optimize provisioning scan based on already known channel */
 375                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 376                         wpa_s->wps_freq);
 377                 params->freqs = os_zalloc(2 * sizeof(int));
 378                 if (params->freqs)
 379                         params->freqs[0] = wpa_s->wps_freq;
 380                 wpa_s->known_wps_freq = 0; /* only do this once */
 381         }
 382 #endif /* CONFIG_WPS */
 383 }
 384
 385
 386 #ifdef CONFIG_INTERWORKING
 387 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 388                                            struct wpabuf *buf)
 389 {
 390         if (wpa_s->conf->interworking == 0)
 391                 return;
 392
 393         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 394         wpabuf_put_u8(buf, 4);
 395         wpabuf_put_u8(buf, 0x00);
 396         wpabuf_put_u8(buf, 0x00);
 397         wpabuf_put_u8(buf, 0x00);
 398         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 399
 400         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 401         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 402                       1 + ETH_ALEN);
 403         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 404         /* No Venue Info */
 405         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 406                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 407 }
 408 #endif /* CONFIG_INTERWORKING */
 409
 410
 411 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 412 {
 413         struct wpabuf *extra_ie = NULL;
 414 #ifdef CONFIG_WPS
 415         int wps = 0;
 416         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 417 #endif /* CONFIG_WPS */
 418
 419 #ifdef CONFIG_INTERWORKING
 420         if (wpa_s->conf->interworking &&
 421             wpabuf_resize(&extra_ie, 100) == 0)
 422                 wpas_add_interworking_elements(wpa_s, extra_ie);
 423 #endif /* CONFIG_INTERWORKING */
 424
 425 #ifdef CONFIG_WPS
 426         wps = wpas_wps_in_use(wpa_s, &req_type);
 427
 428         if (wps) {
 429                 struct wpabuf *wps_ie;
 430                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 431                                                 DEV_PW_DEFAULT,
 432                                                 &wpa_s->wps->dev,
 433                                                 wpa_s->wps->uuid, req_type,
 434                                                 0, NULL);
 435                 if (wps_ie) {
 436                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 437                                 wpabuf_put_buf(extra_ie, wps_ie);
 438                         wpabuf_free(wps_ie);
 439                 }
 440         }
 441
 442 #ifdef CONFIG_P2P
 443         if (wps) {
 444                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 445                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 446                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 447         }
 448 #endif /* CONFIG_P2P */
 449
 450 #endif /* CONFIG_WPS */
 451
 452 #ifdef CONFIG_HS20
 453         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 454                 wpas_hs20_add_indication(extra_ie);
 455 #endif /* CONFIG_HS20 */
 456
 457         return extra_ie;
 458 }
 459
 460
 461 #ifdef CONFIG_P2P
 462
 463 /*
 464  * Check whether there are any enabled networks or credentials that could be
 465  * used for a non-P2P connection.
 466  */
 467 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 468 {
 469         struct wpa_ssid *ssid;
 470
 471         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 472                 if (wpas_network_disabled(wpa_s, ssid))
 473                         continue;
 474                 if (!ssid->p2p_group)
 475                         return 1;
 476         }
 477
 478         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 479             wpa_s->conf->auto_interworking)
 480                 return 1;
 481
 482         return 0;
 483 }
 484
 485 #endif /* CONFIG_P2P */
 486
 487
 488 static struct hostapd_hw_modes * get_mode(struct hostapd_hw_modes *modes,
 489                                           u16 num_modes,
 490                                           enum hostapd_hw_mode mode)
 491 {
 492         u16 i;
 493
 494         for (i = 0; i < num_modes; i++) {
 495                 if (modes[i].mode == mode)
 496                         return &modes[i];
 497         }
 498
 499         return NULL;
 500 }
 501
 502
 503 static void wpa_setband_scan_freqs_list(struct wpa_supplicant *wpa_s,
 504                                         enum hostapd_hw_mode band,
 505                                         struct wpa_driver_scan_params *params)
 506 {
 507         /* Include only supported channels for the specified band */
 508         struct hostapd_hw_modes *mode;
 509         int count, i;
 510
 511         mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, band);
 512         if (mode == NULL) {
 513                 /* No channels supported in this band - use empty list */
 514                 params->freqs = os_zalloc(sizeof(int));
 515                 return;
 516         }
 517
 518         params->freqs = os_zalloc((mode->num_channels + 1) * sizeof(int));
 519         if (params->freqs == NULL)
 520                 return;
 521         for (count = 0, i = 0; i < mode->num_channels; i++) {
 522                 if (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED)
 523                         continue;
 524                 params->freqs[count++] = mode->channels[i].freq;
 525         }
 526 }
 527
 528
 529 static void wpa_setband_scan_freqs(struct wpa_supplicant *wpa_s,
 530                                    struct wpa_driver_scan_params *params)
 531 {
 532         if (wpa_s->hw.modes == NULL)
 533                 return; /* unknown what channels the driver supports */
 534         if (params->freqs)
 535                 return; /* already using a limited channel set */
 536         if (wpa_s->setband == WPA_SETBAND_5G)
 537                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211A,
 538                                             params);
 539         else if (wpa_s->setband == WPA_SETBAND_2G)
 540                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211G,
 541                                             params);
 542 }
 543
 544
 545 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 546 {
 547         struct wpa_supplicant *wpa_s = eloop_ctx;
 548         struct wpa_ssid *ssid;
 549         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 550         int ret;
 551         struct wpabuf *extra_ie = NULL;
 552         struct wpa_driver_scan_params params;
 553         struct wpa_driver_scan_params *scan_params;
 554         size_t max_ssids;
 555         enum wpa_states prev_state;
 556
 557         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 558                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 559                 wpas_p2p_continue_after_scan(wpa_s);
 560                 return;
 561         }
 562
 563         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 564                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 565                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 566                 wpas_p2p_continue_after_scan(wpa_s);
 567                 return;
 568         }
 569
 570         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 571             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 572                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 573                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 574                 wpas_p2p_continue_after_scan(wpa_s);
 575                 return;
 576         }
 577
 578         if (wpa_s->conf->ap_scan != 0 &&
 579             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 580                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 581                         "overriding ap_scan configuration");
 582                 wpa_s->conf->ap_scan = 0;
 583                 wpas_notify_ap_scan_changed(wpa_s);
 584         }
 585
 586         if (wpa_s->conf->ap_scan == 0) {
 587                 wpa_supplicant_gen_assoc_event(wpa_s);
 588                 return;
 589         }
 590
 591 #ifdef CONFIG_P2P
 592         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
 593                 if (wpa_s->sta_scan_pending &&
 594                     wpas_p2p_in_progress(wpa_s) == 2 &&
 595                     wpa_s->global->p2p_cb_on_scan_complete) {
 596                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 597                                 "mode scan during P2P search");
 598                 } else {
 599                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 600                                 "while P2P operation is in progress");
 601                         wpa_s->sta_scan_pending = 1;
 602                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 603                         return;
 604                 }
 605         }
 606 #endif /* CONFIG_P2P */
 607
 608 #ifdef CONFIG_GAS
 609         if (gas_query_in_progress(wpa_s->gas)) {
 610                 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
 611                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 612                 return;
 613         }
 614 #endif /* CONFIG_GAS */
 615
 616         if (wpa_s->conf->ap_scan == 2)
 617                 max_ssids = 1;
 618         else {
 619                 max_ssids = wpa_s->max_scan_ssids;
 620                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 621                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 622         }
 623
 624         scan_req = wpa_s->scan_req;
 625         wpa_s->scan_req = NORMAL_SCAN_REQ;
 626
 627         os_memset(&params, 0, sizeof(params));
 628
 629         prev_state = wpa_s->wpa_state;
 630         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 631             wpa_s->wpa_state == WPA_INACTIVE)
 632                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 633
 634         /*
 635          * If autoscan has set its own scanning parameters
 636          */
 637         if (wpa_s->autoscan_params != NULL) {
 638                 scan_params = wpa_s->autoscan_params;
 639                 goto scan;
 640         }
 641
 642         if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
 643                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 644                         if (ssid == wpa_s->connect_without_scan)
 645                                 break;
 646                 }
 647                 wpa_s->connect_without_scan = NULL;
 648                 if (ssid) {
 649                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 650                                    "without scan step");
 651                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 652                         return;
 653                 }
 654         }
 655
 656 #ifdef CONFIG_P2P
 657         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 658             wpa_s->go_params) {
 659                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during P2P group formation (p2p_in_provisioning=%d show_group_started=%d)",
 660                            wpa_s->p2p_in_provisioning,
 661                            wpa_s->show_group_started);
 662                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 663                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 664                 params.num_ssids = 1;
 665                 goto ssid_list_set;
 666         }
 667 #endif /* CONFIG_P2P */
 668
 669         /* Find the starting point from which to continue scanning */
 670         ssid = wpa_s->conf->ssid;
 671         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 672                 while (ssid) {
 673                         if (ssid == wpa_s->prev_scan_ssid) {
 674                                 ssid = ssid->next;
 675                                 break;
 676                         }
 677                         ssid = ssid->next;
 678                 }
 679         }
 680
 681         if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 682                 wpa_s->connect_without_scan = NULL;
 683                 wpa_s->prev_scan_wildcard = 0;
 684                 wpa_supplicant_assoc_try(wpa_s, ssid);
 685                 return;
 686         } else if (wpa_s->conf->ap_scan == 2) {
 687                 /*
 688                  * User-initiated scan request in ap_scan == 2; scan with
 689                  * wildcard SSID.
 690                  */
 691                 ssid = NULL;
 692         } else {
 693                 struct wpa_ssid *start = ssid, *tssid;
 694                 int freqs_set = 0;
 695                 if (ssid == NULL && max_ssids > 1)
 696                         ssid = wpa_s->conf->ssid;
 697                 while (ssid) {
 698                         if (!wpas_network_disabled(wpa_s, ssid) &&
 699                             ssid->scan_ssid) {
 700                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 701                                                   ssid->ssid, ssid->ssid_len);
 702                                 params.ssids[params.num_ssids].ssid =
 703                                         ssid->ssid;
 704                                 params.ssids[params.num_ssids].ssid_len =
 705                                         ssid->ssid_len;
 706                                 params.num_ssids++;
 707                                 if (params.num_ssids + 1 >= max_ssids)
 708                                         break;
 709                         }
 710                         ssid = ssid->next;
 711                         if (ssid == start)
 712                                 break;
 713                         if (ssid == NULL && max_ssids > 1 &&
 714                             start != wpa_s->conf->ssid)
 715                                 ssid = wpa_s->conf->ssid;
 716                 }
 717
 718                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 719                         if (wpas_network_disabled(wpa_s, tssid))
 720                                 continue;
 721                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 722                                 int_array_concat(&params.freqs,
 723                                                  tssid->scan_freq);
 724                         } else {
 725                                 os_free(params.freqs);
 726                                 params.freqs = NULL;
 727                         }
 728                         freqs_set = 1;
 729                 }
 730                 int_array_sort_unique(params.freqs);
 731         }
 732
 733         if (ssid && max_ssids == 1) {
 734                 /*
 735                  * If the driver is limited to 1 SSID at a time interleave
 736                  * wildcard SSID scans with specific SSID scans to avoid
 737                  * waiting a long time for a wildcard scan.
 738                  */
 739                 if (!wpa_s->prev_scan_wildcard) {
 740                         params.ssids[0].ssid = NULL;
 741                         params.ssids[0].ssid_len = 0;
 742                         wpa_s->prev_scan_wildcard = 1;
 743                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 744                                 "wildcard SSID (Interleave with specific)");
 745                 } else {
 746                         wpa_s->prev_scan_ssid = ssid;
 747                         wpa_s->prev_scan_wildcard = 0;
 748                         wpa_dbg(wpa_s, MSG_DEBUG,
 749                                 "Starting AP scan for specific SSID: %s",
 750                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 751                 }
 752         } else if (ssid) {
 753                 /* max_ssids > 1 */
 754
 755                 wpa_s->prev_scan_ssid = ssid;
 756                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 757                         "the scan request");
 758                 params.num_ssids++;
 759         } else {
 760                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 761                 params.num_ssids++;
 762                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 763                         "SSID");
 764         }
 765 #ifdef CONFIG_P2P
 766 ssid_list_set:
 767 #endif /* CONFIG_P2P */
 768
 769         wpa_supplicant_optimize_freqs(wpa_s, &params);
 770         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 771
 772         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 773                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 774                         "generated frequency list");
 775                 params.freqs = wpa_s->next_scan_freqs;
 776         } else
 777                 os_free(wpa_s->next_scan_freqs);
 778         wpa_s->next_scan_freqs = NULL;
 779         wpa_setband_scan_freqs(wpa_s, &params);
 780
 781         /* See if user specified frequencies. If so, scan only those. */
 782         if (wpa_s->conf->freq_list && !params.freqs) {
 783                 wpa_dbg(wpa_s, MSG_DEBUG,
 784                         "Optimize scan based on conf->freq_list");
 785                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 786         }
 787
 788         /* Use current associated channel? */
 789         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 790                 unsigned int num = wpa_s->num_multichan_concurrent;
 791
 792                 params.freqs = os_calloc(num + 1, sizeof(int));
 793                 if (params.freqs) {
 794                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 795                         if (num > 0) {
 796                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
 797                                         "current operating channels since "
 798                                         "scan_cur_freq is enabled");
 799                         } else {
 800                                 os_free(params.freqs);
 801                                 params.freqs = NULL;
 802                         }
 803                 }
 804         }
 805
 806         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 807                 wpa_s->conf, &params.num_filter_ssids);
 808         if (extra_ie) {
 809                 params.extra_ies = wpabuf_head(extra_ie);
 810                 params.extra_ies_len = wpabuf_len(extra_ie);
 811         }
 812
 813 #ifdef CONFIG_P2P
 814         if (wpa_s->p2p_in_provisioning ||
 815             (wpa_s->show_group_started && wpa_s->go_params)) {
 816                 /*
 817                  * The interface may not yet be in P2P mode, so we have to
 818                  * explicitly request P2P probe to disable CCK rates.
 819                  */
 820                 params.p2p_probe = 1;
 821         }
 822 #endif /* CONFIG_P2P */
 823
 824         scan_params = &params;
 825
 826 scan:
 827 #ifdef CONFIG_P2P
 828         /*
 829          * If the driver does not support multi-channel concurrency and a
 830          * virtual interface that shares the same radio with the wpa_s interface
 831          * is operating there may not be need to scan other channels apart from
 832          * the current operating channel on the other virtual interface. Filter
 833          * out other channels in case we are trying to find a connection for a
 834          * station interface when we are not configured to prefer station
 835          * connection and a concurrent operation is already in process.
 836          */
 837         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 838             !scan_params->freqs && !params.freqs &&
 839             wpas_is_p2p_prioritized(wpa_s) &&
 840             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 841             non_p2p_network_enabled(wpa_s)) {
 842                 unsigned int num = wpa_s->num_multichan_concurrent;
 843
 844                 params.freqs = os_calloc(num + 1, sizeof(int));
 845                 if (params.freqs) {
 846                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 847                         if (num > 0 && num == wpa_s->num_multichan_concurrent) {
 848                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
 849                         } else {
 850                                 os_free(params.freqs);
 851                                 params.freqs = NULL;
 852                         }
 853                 }
 854         }
 855 #endif /* CONFIG_P2P */
 856
 857         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 858
 859         wpabuf_free(extra_ie);
 860         os_free(params.freqs);
 861         os_free(params.filter_ssids);
 862
 863         if (ret) {
 864                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 865                 if (prev_state != wpa_s->wpa_state)
 866                         wpa_supplicant_set_state(wpa_s, prev_state);
 867                 /* Restore scan_req since we will try to scan again */
 868                 wpa_s->scan_req = scan_req;
 869                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 870         } else {
 871                 wpa_s->scan_for_connection = 0;
 872         }
 873 }
 874
 875
 876 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 877 {
 878         struct os_time remaining, new_int;
 879         int cancelled;
 880
 881         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 882                                              &remaining);
 883
 884         new_int.sec = sec;
 885         new_int.usec = 0;
 886         if (cancelled && os_time_before(&remaining, &new_int)) {
 887                 new_int.sec = remaining.sec;
 888                 new_int.usec = remaining.usec;
 889         }
 890
 891         if (cancelled) {
 892                 eloop_register_timeout(new_int.sec, new_int.usec,
 893                                        wpa_supplicant_scan, wpa_s, NULL);
 894         }
 895         wpa_s->scan_interval = sec;
 896 }
 897
 898
 899 /**
 900  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 901  * @wpa_s: Pointer to wpa_supplicant data
 902  * @sec: Number of seconds after which to scan
 903  * @usec: Number of microseconds after which to scan
 904  *
 905  * This function is used to schedule a scan for neighboring access points after
 906  * the specified time.
 907  */
 908 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 909 {
 910         /* If there's at least one network that should be specifically scanned
 911          * then don't cancel the scan and reschedule.  Some drivers do
 912          * background scanning which generates frequent scan results, and that
 913          * causes the specific SSID scan to get continually pushed back and
 914          * never happen, which causes hidden APs to never get probe-scanned.
 915          */
 916         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 917             wpa_s->conf->ap_scan == 1) {
 918                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 919
 920                 while (ssid) {
 921                         if (!wpas_network_disabled(wpa_s, ssid) &&
 922                             ssid->scan_ssid)
 923                                 break;
 924                         ssid = ssid->next;
 925                 }
 926                 if (ssid) {
 927                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 928                                 "ensure that specific SSID scans occur");
 929                         return;
 930                 }
 931         }
 932
 933         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 934                 sec, usec);
 935         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 936         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 937 }
 938
 939
 940 /**
 941  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 942  * @wpa_s: Pointer to wpa_supplicant data
 943  * @sec: Number of seconds after which to scan
 944  * @usec: Number of microseconds after which to scan
 945  * Returns: 0 on success or -1 otherwise
 946  *
 947  * This function is used to schedule periodic scans for neighboring
 948  * access points after the specified time.
 949  */
 950 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 951                                       int sec, int usec)
 952 {
 953         if (!wpa_s->sched_scan_supported)
 954                 return -1;
 955
 956         eloop_register_timeout(sec, usec,
 957                                wpa_supplicant_delayed_sched_scan_timeout,
 958                                wpa_s, NULL);
 959
 960         return 0;
 961 }
 962
 963
 964 /**
 965  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 966  * @wpa_s: Pointer to wpa_supplicant data
 967  * Returns: 0 is sched_scan was started or -1 otherwise
 968  *
 969  * This function is used to schedule periodic scans for neighboring
 970  * access points repeating the scan continuously.
 971  */
 972 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 973 {
 974         struct wpa_driver_scan_params params;
 975         struct wpa_driver_scan_params *scan_params;
 976         enum wpa_states prev_state;
 977         struct wpa_ssid *ssid = NULL;
 978         struct wpabuf *extra_ie = NULL;
 979         int ret;
 980         unsigned int max_sched_scan_ssids;
 981         int wildcard = 0;
 982         int need_ssids;
 983
 984         if (!wpa_s->sched_scan_supported)
 985                 return -1;
 986
 987         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 988                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 989         else
 990                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 991         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 992                 return -1;
 993
 994         if (wpa_s->sched_scanning) {
 995                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 996                 return 0;
 997         }
 998
 999         need_ssids = 0;
1000         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
1001                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
1002                         /* Use wildcard SSID to find this network */
1003                         wildcard = 1;
1004                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
1005                            ssid->ssid_len)
1006                         need_ssids++;
1007
1008 #ifdef CONFIG_WPS
1009                 if (!wpas_network_disabled(wpa_s, ssid) &&
1010                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
1011                         /*
1012                          * Normal scan is more reliable and faster for WPS
1013                          * operations and since these are for short periods of
1014                          * time, the benefit of trying to use sched_scan would
1015                          * be limited.
1016                          */
1017                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1018                                 "sched_scan for WPS");
1019                         return -1;
1020                 }
1021 #endif /* CONFIG_WPS */
1022         }
1023         if (wildcard)
1024                 need_ssids++;
1025
1026         if (wpa_s->normal_scans < 3 &&
1027             (need_ssids <= wpa_s->max_scan_ssids ||
1028              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
1029                 /*
1030                  * When normal scan can speed up operations, use that for the
1031                  * first operations before starting the sched_scan to allow
1032                  * user space sleep more. We do this only if the normal scan
1033                  * has functionality that is suitable for this or if the
1034                  * sched_scan does not have better support for multiple SSIDs.
1035                  */
1036                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1037                         "sched_scan for initial scans (normal_scans=%d)",
1038                         wpa_s->normal_scans);
1039                 return -1;
1040         }
1041
1042         os_memset(&params, 0, sizeof(params));
1043
1044         /* If we can't allocate space for the filters, we just don't filter */
1045         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1046                                         sizeof(struct wpa_driver_scan_filter));
1047
1048         prev_state = wpa_s->wpa_state;
1049         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1050             wpa_s->wpa_state == WPA_INACTIVE)
1051                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1052
1053         if (wpa_s->autoscan_params != NULL) {
1054                 scan_params = wpa_s->autoscan_params;
1055                 goto scan;
1056         }
1057
1058         /* Find the starting point from which to continue scanning */
1059         ssid = wpa_s->conf->ssid;
1060         if (wpa_s->prev_sched_ssid) {
1061                 while (ssid) {
1062                         if (ssid == wpa_s->prev_sched_ssid) {
1063                                 ssid = ssid->next;
1064                                 break;
1065                         }
1066                         ssid = ssid->next;
1067                 }
1068         }
1069
1070         if (!ssid || !wpa_s->prev_sched_ssid) {
1071                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1072                 if (wpa_s->conf->sched_scan_interval)
1073                         wpa_s->sched_scan_interval =
1074                                 wpa_s->conf->sched_scan_interval;
1075                 if (wpa_s->sched_scan_interval == 0)
1076                         wpa_s->sched_scan_interval = 10;
1077                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1078                 wpa_s->first_sched_scan = 1;
1079                 ssid = wpa_s->conf->ssid;
1080                 wpa_s->prev_sched_ssid = ssid;
1081         }
1082
1083         if (wildcard) {
1084                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1085                 params.num_ssids++;
1086         }
1087
1088         while (ssid) {
1089                 if (wpas_network_disabled(wpa_s, ssid))
1090                         goto next;
1091
1092                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1093                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1094                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1095                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1096                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1097                                   ssid->ssid, ssid->ssid_len);
1098                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1099                                 ssid->ssid_len;
1100                         params.num_filter_ssids++;
1101                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1102                 {
1103                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1104                                 "filter for sched_scan - drop filter");
1105                         os_free(params.filter_ssids);
1106                         params.filter_ssids = NULL;
1107                         params.num_filter_ssids = 0;
1108                 }
1109
1110                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1111                         if (params.num_ssids == max_sched_scan_ssids)
1112                                 break; /* only room for broadcast SSID */
1113                         wpa_dbg(wpa_s, MSG_DEBUG,
1114                                 "add to active scan ssid: %s",
1115                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1116                         params.ssids[params.num_ssids].ssid =
1117                                 ssid->ssid;
1118                         params.ssids[params.num_ssids].ssid_len =
1119                                 ssid->ssid_len;
1120                         params.num_ssids++;
1121                         if (params.num_ssids >= max_sched_scan_ssids) {
1122                                 wpa_s->prev_sched_ssid = ssid;
1123                                 do {
1124                                         ssid = ssid->next;
1125                                 } while (ssid &&
1126                                          (wpas_network_disabled(wpa_s, ssid) ||
1127                                           !ssid->scan_ssid));
1128                                 break;
1129                         }
1130                 }
1131
1132         next:
1133                 wpa_s->prev_sched_ssid = ssid;
1134                 ssid = ssid->next;
1135         }
1136
1137         if (params.num_filter_ssids == 0) {
1138                 os_free(params.filter_ssids);
1139                 params.filter_ssids = NULL;
1140         }
1141
1142         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1143         if (extra_ie) {
1144                 params.extra_ies = wpabuf_head(extra_ie);
1145                 params.extra_ies_len = wpabuf_len(extra_ie);
1146         }
1147
1148         scan_params = &params;
1149
1150 scan:
1151         if (ssid || !wpa_s->first_sched_scan) {
1152                 wpa_dbg(wpa_s, MSG_DEBUG,
1153                         "Starting sched scan: interval %d timeout %d",
1154                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1155         } else {
1156                 wpa_dbg(wpa_s, MSG_DEBUG,
1157                         "Starting sched scan: interval %d (no timeout)",
1158                         wpa_s->sched_scan_interval);
1159         }
1160
1161         wpa_setband_scan_freqs(wpa_s, scan_params);
1162
1163         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1164                                               wpa_s->sched_scan_interval);
1165         wpabuf_free(extra_ie);
1166         os_free(params.filter_ssids);
1167         if (ret) {
1168                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1169                 if (prev_state != wpa_s->wpa_state)
1170                         wpa_supplicant_set_state(wpa_s, prev_state);
1171                 return ret;
1172         }
1173
1174         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1175         if (ssid || !wpa_s->first_sched_scan) {
1176                 wpa_s->sched_scan_timed_out = 0;
1177                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1178                                        wpa_supplicant_sched_scan_timeout,
1179                                        wpa_s, NULL);
1180                 wpa_s->first_sched_scan = 0;
1181                 wpa_s->sched_scan_timeout /= 2;
1182                 wpa_s->sched_scan_interval *= 2;
1183                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1184                         wpa_s->sched_scan_interval = 10;
1185                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1186                 }
1187         }
1188
1189         /* If there is no more ssids, start next time from the beginning */
1190         if (!ssid)
1191                 wpa_s->prev_sched_ssid = NULL;
1192
1193         return 0;
1194 }
1195
1196
1197 /**
1198  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1199  * @wpa_s: Pointer to wpa_supplicant data
1200  *
1201  * This function is used to cancel a scan request scheduled with
1202  * wpa_supplicant_req_scan().
1203  */
1204 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1205 {
1206         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1207         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1208         wpas_p2p_continue_after_scan(wpa_s);
1209 }
1210
1211
1212 /**
1213  * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1214  * @wpa_s: Pointer to wpa_supplicant data
1215  *
1216  * This function is used to stop a delayed scheduled scan.
1217  */
1218 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1219 {
1220         if (!wpa_s->sched_scan_supported)
1221                 return;
1222
1223         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1224         eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1225                              wpa_s, NULL);
1226 }
1227
1228
1229 /**
1230  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1231  * @wpa_s: Pointer to wpa_supplicant data
1232  *
1233  * This function is used to stop a periodic scheduled scan.
1234  */
1235 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1236 {
1237         if (!wpa_s->sched_scanning)
1238                 return;
1239
1240         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1241         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1242         wpa_supplicant_stop_sched_scan(wpa_s);
1243 }
1244
1245
1246 /**
1247  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1248  * @wpa_s: Pointer to wpa_supplicant data
1249  * @scanning: Whether scanning is currently in progress
1250  *
1251  * This function is to generate scanning notifycations. It is called whenever
1252  * there may have been a change in scanning (scan started, completed, stopped).
1253  * wpas_notify_scanning() is called whenever the scanning state changed from the
1254  * previously notified state.
1255  */
1256 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1257                                     int scanning)
1258 {
1259         if (wpa_s->scanning != scanning) {
1260                 wpa_s->scanning = scanning;
1261                 wpas_notify_scanning(wpa_s);
1262         }
1263 }
1264
1265
1266 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1267 {
1268         int rate = 0;
1269         const u8 *ie;
1270         int i;
1271
1272         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1273         for (i = 0; ie && i < ie[1]; i++) {
1274                 if ((ie[i + 2] & 0x7f) > rate)
1275                         rate = ie[i + 2] & 0x7f;
1276         }
1277
1278         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1279         for (i = 0; ie && i < ie[1]; i++) {
1280                 if ((ie[i + 2] & 0x7f) > rate)
1281                         rate = ie[i + 2] & 0x7f;
1282         }
1283
1284         return rate;
1285 }
1286
1287
1288 /**
1289  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1290  * @res: Scan result entry
1291  * @ie: Information element identitifier (WLAN_EID_*)
1292  * Returns: Pointer to the information element (id field) or %NULL if not found
1293  *
1294  * This function returns the first matching information element in the scan
1295  * result.
1296  */
1297 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1298 {
1299         const u8 *end, *pos;
1300
1301         pos = (const u8 *) (res + 1);
1302         end = pos + res->ie_len;
1303
1304         while (pos + 1 < end) {
1305                 if (pos + 2 + pos[1] > end)
1306                         break;
1307                 if (pos[0] == ie)
1308                         return pos;
1309                 pos += 2 + pos[1];
1310         }
1311
1312         return NULL;
1313 }
1314
1315
1316 /**
1317  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1318  * @res: Scan result entry
1319  * @vendor_type: Vendor type (four octets starting the IE payload)
1320  * Returns: Pointer to the information element (id field) or %NULL if not found
1321  *
1322  * This function returns the first matching information element in the scan
1323  * result.
1324  */
1325 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1326                                   u32 vendor_type)
1327 {
1328         const u8 *end, *pos;
1329
1330         pos = (const u8 *) (res + 1);
1331         end = pos + res->ie_len;
1332
1333         while (pos + 1 < end) {
1334                 if (pos + 2 + pos[1] > end)
1335                         break;
1336                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1337                     vendor_type == WPA_GET_BE32(&pos[2]))
1338                         return pos;
1339                 pos += 2 + pos[1];
1340         }
1341
1342         return NULL;
1343 }
1344
1345
1346 /**
1347  * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1348  * @res: Scan result entry
1349  * @vendor_type: Vendor type (four octets starting the IE payload)
1350  * Returns: Pointer to the information element (id field) or %NULL if not found
1351  *
1352  * This function returns the first matching information element in the scan
1353  * result.
1354  *
1355  * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1356  * from Beacon frames instead of either Beacon or Probe Response frames.
1357  */
1358 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1359                                          u32 vendor_type)
1360 {
1361         const u8 *end, *pos;
1362
1363         if (res->beacon_ie_len == 0)
1364                 return NULL;
1365
1366         pos = (const u8 *) (res + 1);
1367         pos += res->ie_len;
1368         end = pos + res->beacon_ie_len;
1369
1370         while (pos + 1 < end) {
1371                 if (pos + 2 + pos[1] > end)
1372                         break;
1373                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1374                     vendor_type == WPA_GET_BE32(&pos[2]))
1375                         return pos;
1376                 pos += 2 + pos[1];
1377         }
1378
1379         return NULL;
1380 }
1381
1382
1383 /**
1384  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1385  * @res: Scan result entry
1386  * @vendor_type: Vendor type (four octets starting the IE payload)
1387  * Returns: Pointer to the information element payload or %NULL if not found
1388  *
1389  * This function returns concatenated payload of possibly fragmented vendor
1390  * specific information elements in the scan result. The caller is responsible
1391  * for freeing the returned buffer.
1392  */
1393 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1394                                              u32 vendor_type)
1395 {
1396         struct wpabuf *buf;
1397         const u8 *end, *pos;
1398
1399         buf = wpabuf_alloc(res->ie_len);
1400         if (buf == NULL)
1401                 return NULL;
1402
1403         pos = (const u8 *) (res + 1);
1404         end = pos + res->ie_len;
1405
1406         while (pos + 1 < end) {
1407                 if (pos + 2 + pos[1] > end)
1408                         break;
1409                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1410                     vendor_type == WPA_GET_BE32(&pos[2]))
1411                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1412                 pos += 2 + pos[1];
1413         }
1414
1415         if (wpabuf_len(buf) == 0) {
1416                 wpabuf_free(buf);
1417                 buf = NULL;
1418         }
1419
1420         return buf;
1421 }
1422
1423
1424 /*
1425  * Channels with a great SNR can operate at full rate. What is a great SNR?
1426  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1427  * rule of thumb is that any SNR above 20 is good." This one
1428  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1429  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1430  * conservative value.
1431  */
1432 #define GREAT_SNR 30
1433
1434 /* Compare function for sorting scan results. Return >0 if @b is considered
1435  * better. */
1436 static int wpa_scan_result_compar(const void *a, const void *b)
1437 {
1438 #define IS_5GHZ(n) (n > 4000)
1439 #define MIN(a,b) a < b ? a : b
1440         struct wpa_scan_res **_wa = (void *) a;
1441         struct wpa_scan_res **_wb = (void *) b;
1442         struct wpa_scan_res *wa = *_wa;
1443         struct wpa_scan_res *wb = *_wb;
1444         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1445         int snr_a, snr_b;
1446
1447         /* WPA/WPA2 support preferred */
1448         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1449                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1450         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1451                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1452
1453         if (wpa_b && !wpa_a)
1454                 return 1;
1455         if (!wpa_b && wpa_a)
1456                 return -1;
1457
1458         /* privacy support preferred */
1459         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1460             (wb->caps & IEEE80211_CAP_PRIVACY))
1461                 return 1;
1462         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1463             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1464                 return -1;
1465
1466         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1467             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1468                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1469                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1470         } else {
1471                 /* Not suitable information to calculate SNR, so use level */
1472                 snr_a = wa->level;
1473                 snr_b = wb->level;
1474         }
1475
1476         /* best/max rate preferred if SNR close enough */
1477         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1478             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1479                 maxrate_a = wpa_scan_get_max_rate(wa);
1480                 maxrate_b = wpa_scan_get_max_rate(wb);
1481                 if (maxrate_a != maxrate_b)
1482                         return maxrate_b - maxrate_a;
1483                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1484                         return IS_5GHZ(wa->freq) ? -1 : 1;
1485         }
1486
1487         /* use freq for channel preference */
1488
1489         /* all things being equal, use SNR; if SNRs are
1490          * identical, use quality values since some drivers may only report
1491          * that value and leave the signal level zero */
1492         if (snr_b == snr_a)
1493                 return wb->qual - wa->qual;
1494         return snr_b - snr_a;
1495 #undef MIN
1496 #undef IS_5GHZ
1497 }
1498
1499
1500 #ifdef CONFIG_WPS
1501 /* Compare function for sorting scan results when searching a WPS AP for
1502  * provisioning. Return >0 if @b is considered better. */
1503 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1504 {
1505         struct wpa_scan_res **_wa = (void *) a;
1506         struct wpa_scan_res **_wb = (void *) b;
1507         struct wpa_scan_res *wa = *_wa;
1508         struct wpa_scan_res *wb = *_wb;
1509         int uses_wps_a, uses_wps_b;
1510         struct wpabuf *wps_a, *wps_b;
1511         int res;
1512
1513         /* Optimization - check WPS IE existence before allocated memory and
1514          * doing full reassembly. */
1515         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1516         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1517         if (uses_wps_a && !uses_wps_b)
1518                 return -1;
1519         if (!uses_wps_a && uses_wps_b)
1520                 return 1;
1521
1522         if (uses_wps_a && uses_wps_b) {
1523                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1524                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1525                 res = wps_ap_priority_compar(wps_a, wps_b);
1526                 wpabuf_free(wps_a);
1527                 wpabuf_free(wps_b);
1528                 if (res)
1529                         return res;
1530         }
1531
1532         /*
1533          * Do not use current AP security policy as a sorting criteria during
1534          * WPS provisioning step since the AP may get reconfigured at the
1535          * completion of provisioning.
1536          */
1537
1538         /* all things being equal, use signal level; if signal levels are
1539          * identical, use quality values since some drivers may only report
1540          * that value and leave the signal level zero */
1541         if (wb->level == wa->level)
1542                 return wb->qual - wa->qual;
1543         return wb->level - wa->level;
1544 }
1545 #endif /* CONFIG_WPS */
1546
1547
1548 static void dump_scan_res(struct wpa_scan_results *scan_res)
1549 {
1550 #ifndef CONFIG_NO_STDOUT_DEBUG
1551         size_t i;
1552
1553         if (scan_res->res == NULL || scan_res->num == 0)
1554                 return;
1555
1556         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1557
1558         for (i = 0; i < scan_res->num; i++) {
1559                 struct wpa_scan_res *r = scan_res->res[i];
1560                 u8 *pos;
1561                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1562                     == WPA_SCAN_LEVEL_DBM) {
1563                         int snr = r->level - r->noise;
1564                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1565                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1566                                    "age=%u",
1567                                    MAC2STR(r->bssid), r->freq, r->qual,
1568                                    r->noise, r->level, snr,
1569                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1570                                    r->age);
1571                 } else {
1572                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1573                                    "noise=%d level=%d flags=0x%x age=%u",
1574                                    MAC2STR(r->bssid), r->freq, r->qual,
1575                                    r->noise, r->level, r->flags, r->age);
1576                 }
1577                 pos = (u8 *) (r + 1);
1578                 if (r->ie_len)
1579                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1580                 pos += r->ie_len;
1581                 if (r->beacon_ie_len)
1582                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1583                                     pos, r->beacon_ie_len);
1584         }
1585 #endif /* CONFIG_NO_STDOUT_DEBUG */
1586 }
1587
1588
1589 /**
1590  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1591  * @wpa_s: Pointer to wpa_supplicant data
1592  * @bssid: BSSID to check
1593  * Returns: 0 if the BSSID is filtered or 1 if not
1594  *
1595  * This function is used to filter out specific BSSIDs from scan reslts mainly
1596  * for testing purposes (SET bssid_filter ctrl_iface command).
1597  */
1598 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1599                                       const u8 *bssid)
1600 {
1601         size_t i;
1602
1603         if (wpa_s->bssid_filter == NULL)
1604                 return 1;
1605
1606         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1607                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1608                               ETH_ALEN) == 0)
1609                         return 1;
1610         }
1611
1612         return 0;
1613 }
1614
1615
1616 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1617                             struct wpa_scan_results *res)
1618 {
1619         size_t i, j;
1620
1621         if (wpa_s->bssid_filter == NULL)
1622                 return;
1623
1624         for (i = 0, j = 0; i < res->num; i++) {
1625                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1626                                                       res->res[i]->bssid)) {
1627                         res->res[j++] = res->res[i];
1628                 } else {
1629                         os_free(res->res[i]);
1630                         res->res[i] = NULL;
1631                 }
1632         }
1633
1634         if (res->num != j) {
1635                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1636                            (int) (res->num - j));
1637                 res->num = j;
1638         }
1639 }
1640
1641
1642 /**
1643  * wpa_supplicant_get_scan_results - Get scan results
1644  * @wpa_s: Pointer to wpa_supplicant data
1645  * @info: Information about what was scanned or %NULL if not available
1646  * @new_scan: Whether a new scan was performed
1647  * Returns: Scan results, %NULL on failure
1648  *
1649  * This function request the current scan results from the driver and updates
1650  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1651  * results with wpa_scan_results_free().
1652  */
1653 struct wpa_scan_results *
1654 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1655                                 struct scan_info *info, int new_scan)
1656 {
1657         struct wpa_scan_results *scan_res;
1658         size_t i;
1659         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1660
1661         scan_res = wpa_drv_get_scan_results2(wpa_s);
1662         if (scan_res == NULL) {
1663                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1664                 return NULL;
1665         }
1666         if (scan_res->fetch_time.sec == 0) {
1667                 /*
1668                  * Make sure we have a valid timestamp if the driver wrapper
1669                  * does not set this.
1670                  */
1671                 os_get_time(&scan_res->fetch_time);
1672         }
1673         filter_scan_res(wpa_s, scan_res);
1674
1675 #ifdef CONFIG_WPS
1676         if (wpas_wps_in_progress(wpa_s)) {
1677                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1678                         "provisioning rules");
1679                 compar = wpa_scan_result_wps_compar;
1680         }
1681 #endif /* CONFIG_WPS */
1682
1683         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1684               compar);
1685         dump_scan_res(scan_res);
1686
1687         wpa_bss_update_start(wpa_s);
1688         for (i = 0; i < scan_res->num; i++)
1689                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1690                                         &scan_res->fetch_time);
1691         wpa_bss_update_end(wpa_s, info, new_scan);
1692
1693         return scan_res;
1694 }
1695
1696
1697 /**
1698  * wpa_supplicant_update_scan_results - Update scan results from the driver
1699  * @wpa_s: Pointer to wpa_supplicant data
1700  * Returns: 0 on success, -1 on failure
1701  *
1702  * This function updates the BSS table within wpa_supplicant based on the
1703  * currently available scan results from the driver without requesting a new
1704  * scan. This is used in cases where the driver indicates an association
1705  * (including roaming within ESS) and wpa_supplicant does not yet have the
1706  * needed information to complete the connection (e.g., to perform validation
1707  * steps in 4-way handshake).
1708  */
1709 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1710 {
1711         struct wpa_scan_results *scan_res;
1712         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1713         if (scan_res == NULL)
1714                 return -1;
1715         wpa_scan_results_free(scan_res);
1716
1717         return 0;
1718 }
1719
1720
1721 /**
1722  * scan_only_handler - Reports scan results
1723  */
1724 void scan_only_handler(struct wpa_supplicant *wpa_s,
1725                        struct wpa_scan_results *scan_res)
1726 {
1727         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1728         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1729         wpas_notify_scan_results(wpa_s);
1730         wpas_notify_scan_done(wpa_s, 1);
1731 }
1732
1733
1734 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1735 {
1736         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1737 }