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
 485 /*
 486  * Find the operating frequency of any other virtual interface that is using
 487  * the same radio concurrently.
 488  */
 489 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
 490 {
 491         const char *rn, *rn2;
 492         struct wpa_supplicant *ifs;
 493         u8 bssid[ETH_ALEN];
 494
 495         if (!wpa_s->driver->get_radio_name)
 496                 return -1;
 497
 498         rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
 499         if (rn == NULL || rn[0] == '\0')
 500                 return -1;
 501
 502         for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
 503                 if (ifs == wpa_s || !ifs->driver->get_radio_name)
 504                         continue;
 505
 506                 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
 507                 if (!rn2 || os_strcmp(rn, rn2) != 0)
 508                         continue;
 509
 510                 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
 511                         continue;
 512
 513                 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
 514                     ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
 515                         return ifs->current_ssid->frequency;
 516                 if (wpa_drv_get_bssid(ifs, bssid) == 0)
 517                         return ifs->assoc_freq;
 518         }
 519
 520         return 0;
 521 }
 522
 523 #endif /* CONFIG_P2P */
 524
 525
 526 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 527 {
 528         struct wpa_supplicant *wpa_s = eloop_ctx;
 529         struct wpa_ssid *ssid;
 530         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 531         int ret;
 532         struct wpabuf *extra_ie = NULL;
 533         struct wpa_driver_scan_params params;
 534         struct wpa_driver_scan_params *scan_params;
 535         size_t max_ssids;
 536         enum wpa_states prev_state;
 537
 538         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 539                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 540                 wpas_p2p_continue_after_scan(wpa_s);
 541                 return;
 542         }
 543
 544         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 545                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 546                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 547                 wpas_p2p_continue_after_scan(wpa_s);
 548                 return;
 549         }
 550
 551         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 552             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 553                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 554                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 555                 wpas_p2p_continue_after_scan(wpa_s);
 556                 return;
 557         }
 558
 559         if (wpa_s->conf->ap_scan != 0 &&
 560             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 561                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 562                         "overriding ap_scan configuration");
 563                 wpa_s->conf->ap_scan = 0;
 564                 wpas_notify_ap_scan_changed(wpa_s);
 565         }
 566
 567         if (wpa_s->conf->ap_scan == 0) {
 568                 wpa_supplicant_gen_assoc_event(wpa_s);
 569                 return;
 570         }
 571
 572 #ifdef CONFIG_P2P
 573         if (wpas_p2p_in_progress(wpa_s)) {
 574                 if (wpa_s->sta_scan_pending &&
 575                     wpas_p2p_in_progress(wpa_s) == 2 &&
 576                     wpa_s->global->p2p_cb_on_scan_complete) {
 577                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 578                                 "mode scan during P2P search");
 579                 } else {
 580                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 581                                 "while P2P operation is in progress");
 582                         wpa_s->sta_scan_pending = 1;
 583                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 584                         return;
 585                 }
 586         }
 587 #endif /* CONFIG_P2P */
 588
 589         if (wpa_s->conf->ap_scan == 2)
 590                 max_ssids = 1;
 591         else {
 592                 max_ssids = wpa_s->max_scan_ssids;
 593                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 594                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 595         }
 596
 597         scan_req = wpa_s->scan_req;
 598         wpa_s->scan_req = NORMAL_SCAN_REQ;
 599
 600         os_memset(&params, 0, sizeof(params));
 601
 602         prev_state = wpa_s->wpa_state;
 603         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 604             wpa_s->wpa_state == WPA_INACTIVE)
 605                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 606
 607         /*
 608          * If autoscan has set its own scanning parameters
 609          */
 610         if (wpa_s->autoscan_params != NULL) {
 611                 scan_params = wpa_s->autoscan_params;
 612                 goto scan;
 613         }
 614
 615         if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
 616                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 617                         if (ssid == wpa_s->connect_without_scan)
 618                                 break;
 619                 }
 620                 wpa_s->connect_without_scan = NULL;
 621                 if (ssid) {
 622                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 623                                    "without scan step");
 624                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 625                         return;
 626                 }
 627         }
 628
 629 #ifdef CONFIG_P2P
 630         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 631             wpa_s->go_params) {
 632                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 633                            "P2P group formation");
 634                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 635                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 636                 params.num_ssids = 1;
 637                 goto ssid_list_set;
 638         }
 639 #endif /* CONFIG_P2P */
 640
 641         /* Find the starting point from which to continue scanning */
 642         ssid = wpa_s->conf->ssid;
 643         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 644                 while (ssid) {
 645                         if (ssid == wpa_s->prev_scan_ssid) {
 646                                 ssid = ssid->next;
 647                                 break;
 648                         }
 649                         ssid = ssid->next;
 650                 }
 651         }
 652
 653         if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 654                 wpa_s->connect_without_scan = NULL;
 655                 wpa_s->prev_scan_wildcard = 0;
 656                 wpa_supplicant_assoc_try(wpa_s, ssid);
 657                 return;
 658         } else if (wpa_s->conf->ap_scan == 2) {
 659                 /*
 660                  * User-initiated scan request in ap_scan == 2; scan with
 661                  * wildcard SSID.
 662                  */
 663                 ssid = NULL;
 664         } else {
 665                 struct wpa_ssid *start = ssid, *tssid;
 666                 int freqs_set = 0;
 667                 if (ssid == NULL && max_ssids > 1)
 668                         ssid = wpa_s->conf->ssid;
 669                 while (ssid) {
 670                         if (!wpas_network_disabled(wpa_s, ssid) &&
 671                             ssid->scan_ssid) {
 672                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 673                                                   ssid->ssid, ssid->ssid_len);
 674                                 params.ssids[params.num_ssids].ssid =
 675                                         ssid->ssid;
 676                                 params.ssids[params.num_ssids].ssid_len =
 677                                         ssid->ssid_len;
 678                                 params.num_ssids++;
 679                                 if (params.num_ssids + 1 >= max_ssids)
 680                                         break;
 681                         }
 682                         ssid = ssid->next;
 683                         if (ssid == start)
 684                                 break;
 685                         if (ssid == NULL && max_ssids > 1 &&
 686                             start != wpa_s->conf->ssid)
 687                                 ssid = wpa_s->conf->ssid;
 688                 }
 689
 690                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 691                         if (wpas_network_disabled(wpa_s, tssid))
 692                                 continue;
 693                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 694                                 int_array_concat(&params.freqs,
 695                                                  tssid->scan_freq);
 696                         } else {
 697                                 os_free(params.freqs);
 698                                 params.freqs = NULL;
 699                         }
 700                         freqs_set = 1;
 701                 }
 702                 int_array_sort_unique(params.freqs);
 703         }
 704
 705         if (ssid && max_ssids == 1) {
 706                 /*
 707                  * If the driver is limited to 1 SSID at a time interleave
 708                  * wildcard SSID scans with specific SSID scans to avoid
 709                  * waiting a long time for a wildcard scan.
 710                  */
 711                 if (!wpa_s->prev_scan_wildcard) {
 712                         params.ssids[0].ssid = NULL;
 713                         params.ssids[0].ssid_len = 0;
 714                         wpa_s->prev_scan_wildcard = 1;
 715                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 716                                 "wildcard SSID (Interleave with specific)");
 717                 } else {
 718                         wpa_s->prev_scan_ssid = ssid;
 719                         wpa_s->prev_scan_wildcard = 0;
 720                         wpa_dbg(wpa_s, MSG_DEBUG,
 721                                 "Starting AP scan for specific SSID: %s",
 722                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 723                 }
 724         } else if (ssid) {
 725                 /* max_ssids > 1 */
 726
 727                 wpa_s->prev_scan_ssid = ssid;
 728                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 729                         "the scan request");
 730                 params.num_ssids++;
 731         } else {
 732                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 733                 params.num_ssids++;
 734                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 735                         "SSID");
 736         }
 737 #ifdef CONFIG_P2P
 738 ssid_list_set:
 739 #endif /* CONFIG_P2P */
 740
 741         wpa_supplicant_optimize_freqs(wpa_s, &params);
 742         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 743
 744         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 745                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 746                         "generated frequency list");
 747                 params.freqs = wpa_s->next_scan_freqs;
 748         } else
 749                 os_free(wpa_s->next_scan_freqs);
 750         wpa_s->next_scan_freqs = NULL;
 751
 752         /* See if user specified frequencies. If so, scan only those. */
 753         if (wpa_s->conf->freq_list && !params.freqs) {
 754                 wpa_dbg(wpa_s, MSG_DEBUG,
 755                         "Optimize scan based on conf->freq_list");
 756                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 757         }
 758
 759         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 760                 wpa_s->conf, &params.num_filter_ssids);
 761         if (extra_ie) {
 762                 params.extra_ies = wpabuf_head(extra_ie);
 763                 params.extra_ies_len = wpabuf_len(extra_ie);
 764         }
 765
 766 #ifdef CONFIG_P2P
 767         if (wpa_s->p2p_in_provisioning ||
 768             (wpa_s->show_group_started && wpa_s->go_params)) {
 769                 /*
 770                  * The interface may not yet be in P2P mode, so we have to
 771                  * explicitly request P2P probe to disable CCK rates.
 772                  */
 773                 params.p2p_probe = 1;
 774         }
 775 #endif /* CONFIG_P2P */
 776
 777         scan_params = &params;
 778
 779 scan:
 780 #ifdef CONFIG_P2P
 781         /*
 782          * If the driver does not support multi-channel concurrency and a
 783          * virtual interface that shares the same radio with the wpa_s interface
 784          * is operating there may not be need to scan other channels apart from
 785          * the current operating channel on the other virtual interface. Filter
 786          * out other channels in case we are trying to find a connection for a
 787          * station interface when we are not configured to prefer station
 788          * connection and a concurrent operation is already in process.
 789          */
 790         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 791             !scan_params->freqs && !params.freqs &&
 792             wpas_is_p2p_prioritized(wpa_s) &&
 793             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
 794             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 795             non_p2p_network_enabled(wpa_s)) {
 796                 int freq = shared_vif_oper_freq(wpa_s);
 797                 if (freq > 0) {
 798                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
 799                                 "operating channel (%d MHz) since driver does "
 800                                 "not support multi-channel concurrency", freq);
 801                         params.freqs = os_zalloc(sizeof(int) * 2);
 802                         if (params.freqs)
 803                                 params.freqs[0] = freq;
 804                         scan_params->freqs = params.freqs;
 805                 }
 806         }
 807 #endif /* CONFIG_P2P */
 808
 809         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 810
 811         wpabuf_free(extra_ie);
 812         os_free(params.freqs);
 813         os_free(params.filter_ssids);
 814
 815         if (ret) {
 816                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 817                 if (prev_state != wpa_s->wpa_state)
 818                         wpa_supplicant_set_state(wpa_s, prev_state);
 819                 /* Restore scan_req since we will try to scan again */
 820                 wpa_s->scan_req = scan_req;
 821                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 822         } else {
 823                 wpa_s->scan_for_connection = 0;
 824         }
 825 }
 826
 827
 828 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 829 {
 830         struct os_time remaining, new_int;
 831         int cancelled;
 832
 833         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 834                                              &remaining);
 835
 836         new_int.sec = sec;
 837         new_int.usec = 0;
 838         if (cancelled && os_time_before(&remaining, &new_int)) {
 839                 new_int.sec = remaining.sec;
 840                 new_int.usec = remaining.usec;
 841         }
 842
 843         eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
 844                                wpa_s, NULL);
 845         wpa_s->scan_interval = sec;
 846 }
 847
 848
 849 /**
 850  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 851  * @wpa_s: Pointer to wpa_supplicant data
 852  * @sec: Number of seconds after which to scan
 853  * @usec: Number of microseconds after which to scan
 854  *
 855  * This function is used to schedule a scan for neighboring access points after
 856  * the specified time.
 857  */
 858 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 859 {
 860         /* If there's at least one network that should be specifically scanned
 861          * then don't cancel the scan and reschedule.  Some drivers do
 862          * background scanning which generates frequent scan results, and that
 863          * causes the specific SSID scan to get continually pushed back and
 864          * never happen, which causes hidden APs to never get probe-scanned.
 865          */
 866         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 867             wpa_s->conf->ap_scan == 1) {
 868                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 869
 870                 while (ssid) {
 871                         if (!wpas_network_disabled(wpa_s, ssid) &&
 872                             ssid->scan_ssid)
 873                                 break;
 874                         ssid = ssid->next;
 875                 }
 876                 if (ssid) {
 877                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 878                                 "ensure that specific SSID scans occur");
 879                         return;
 880                 }
 881         }
 882
 883         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 884                 sec, usec);
 885         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 886         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 887 }
 888
 889
 890 /**
 891  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 892  * @wpa_s: Pointer to wpa_supplicant data
 893  * @sec: Number of seconds after which to scan
 894  * @usec: Number of microseconds after which to scan
 895  * Returns: 0 on success or -1 otherwise
 896  *
 897  * This function is used to schedule periodic scans for neighboring
 898  * access points after the specified time.
 899  */
 900 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 901                                       int sec, int usec)
 902 {
 903         if (!wpa_s->sched_scan_supported)
 904                 return -1;
 905
 906         eloop_register_timeout(sec, usec,
 907                                wpa_supplicant_delayed_sched_scan_timeout,
 908                                wpa_s, NULL);
 909
 910         return 0;
 911 }
 912
 913
 914 /**
 915  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 916  * @wpa_s: Pointer to wpa_supplicant data
 917  * Returns: 0 is sched_scan was started or -1 otherwise
 918  *
 919  * This function is used to schedule periodic scans for neighboring
 920  * access points repeating the scan continuously.
 921  */
 922 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 923 {
 924         struct wpa_driver_scan_params params;
 925         struct wpa_driver_scan_params *scan_params;
 926         enum wpa_states prev_state;
 927         struct wpa_ssid *ssid = NULL;
 928         struct wpabuf *extra_ie = NULL;
 929         int ret;
 930         unsigned int max_sched_scan_ssids;
 931         int wildcard = 0;
 932         int need_ssids;
 933
 934         if (!wpa_s->sched_scan_supported)
 935                 return -1;
 936
 937         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 938                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 939         else
 940                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 941         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 942                 return -1;
 943
 944         if (wpa_s->sched_scanning) {
 945                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 946                 return 0;
 947         }
 948
 949         need_ssids = 0;
 950         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 951                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 952                         /* Use wildcard SSID to find this network */
 953                         wildcard = 1;
 954                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 955                            ssid->ssid_len)
 956                         need_ssids++;
 957
 958 #ifdef CONFIG_WPS
 959                 if (!wpas_network_disabled(wpa_s, ssid) &&
 960                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 961                         /*
 962                          * Normal scan is more reliable and faster for WPS
 963                          * operations and since these are for short periods of
 964                          * time, the benefit of trying to use sched_scan would
 965                          * be limited.
 966                          */
 967                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 968                                 "sched_scan for WPS");
 969                         return -1;
 970                 }
 971 #endif /* CONFIG_WPS */
 972         }
 973         if (wildcard)
 974                 need_ssids++;
 975
 976         if (wpa_s->normal_scans < 3 &&
 977             (need_ssids <= wpa_s->max_scan_ssids ||
 978              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 979                 /*
 980                  * When normal scan can speed up operations, use that for the
 981                  * first operations before starting the sched_scan to allow
 982                  * user space sleep more. We do this only if the normal scan
 983                  * has functionality that is suitable for this or if the
 984                  * sched_scan does not have better support for multiple SSIDs.
 985                  */
 986                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 987                         "sched_scan for initial scans (normal_scans=%d)",
 988                         wpa_s->normal_scans);
 989                 return -1;
 990         }
 991
 992         os_memset(&params, 0, sizeof(params));
 993
 994         /* If we can't allocate space for the filters, we just don't filter */
 995         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 996                                         sizeof(struct wpa_driver_scan_filter));
 997
 998         prev_state = wpa_s->wpa_state;
 999         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1000             wpa_s->wpa_state == WPA_INACTIVE)
1001                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1002
1003         if (wpa_s->autoscan_params != NULL) {
1004                 scan_params = wpa_s->autoscan_params;
1005                 goto scan;
1006         }
1007
1008         /* Find the starting point from which to continue scanning */
1009         ssid = wpa_s->conf->ssid;
1010         if (wpa_s->prev_sched_ssid) {
1011                 while (ssid) {
1012                         if (ssid == wpa_s->prev_sched_ssid) {
1013                                 ssid = ssid->next;
1014                                 break;
1015                         }
1016                         ssid = ssid->next;
1017                 }
1018         }
1019
1020         if (!ssid || !wpa_s->prev_sched_ssid) {
1021                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1022                 if (wpa_s->conf->sched_scan_interval)
1023                         wpa_s->sched_scan_interval =
1024                                 wpa_s->conf->sched_scan_interval;
1025                 if (wpa_s->sched_scan_interval == 0)
1026                         wpa_s->sched_scan_interval = 10;
1027                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1028                 wpa_s->first_sched_scan = 1;
1029                 ssid = wpa_s->conf->ssid;
1030                 wpa_s->prev_sched_ssid = ssid;
1031         }
1032
1033         if (wildcard) {
1034                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1035                 params.num_ssids++;
1036         }
1037
1038         while (ssid) {
1039                 if (wpas_network_disabled(wpa_s, ssid))
1040                         goto next;
1041
1042                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1043                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1044                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1045                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1046                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1047                                   ssid->ssid, ssid->ssid_len);
1048                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1049                                 ssid->ssid_len;
1050                         params.num_filter_ssids++;
1051                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1052                 {
1053                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1054                                 "filter for sched_scan - drop filter");
1055                         os_free(params.filter_ssids);
1056                         params.filter_ssids = NULL;
1057                         params.num_filter_ssids = 0;
1058                 }
1059
1060                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1061                         if (params.num_ssids == max_sched_scan_ssids)
1062                                 break; /* only room for broadcast SSID */
1063                         wpa_dbg(wpa_s, MSG_DEBUG,
1064                                 "add to active scan ssid: %s",
1065                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1066                         params.ssids[params.num_ssids].ssid =
1067                                 ssid->ssid;
1068                         params.ssids[params.num_ssids].ssid_len =
1069                                 ssid->ssid_len;
1070                         params.num_ssids++;
1071                         if (params.num_ssids >= max_sched_scan_ssids) {
1072                                 wpa_s->prev_sched_ssid = ssid;
1073                                 do {
1074                                         ssid = ssid->next;
1075                                 } while (ssid &&
1076                                          (wpas_network_disabled(wpa_s, ssid) ||
1077                                           !ssid->scan_ssid));
1078                                 break;
1079                         }
1080                 }
1081
1082         next:
1083                 wpa_s->prev_sched_ssid = ssid;
1084                 ssid = ssid->next;
1085         }
1086
1087         if (params.num_filter_ssids == 0) {
1088                 os_free(params.filter_ssids);
1089                 params.filter_ssids = NULL;
1090         }
1091
1092         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1093         if (extra_ie) {
1094                 params.extra_ies = wpabuf_head(extra_ie);
1095                 params.extra_ies_len = wpabuf_len(extra_ie);
1096         }
1097
1098         scan_params = &params;
1099
1100 scan:
1101         if (ssid || !wpa_s->first_sched_scan) {
1102                 wpa_dbg(wpa_s, MSG_DEBUG,
1103                         "Starting sched scan: interval %d timeout %d",
1104                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1105         } else {
1106                 wpa_dbg(wpa_s, MSG_DEBUG,
1107                         "Starting sched scan: interval %d (no timeout)",
1108                         wpa_s->sched_scan_interval);
1109         }
1110
1111         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1112                                               wpa_s->sched_scan_interval);
1113         wpabuf_free(extra_ie);
1114         os_free(params.filter_ssids);
1115         if (ret) {
1116                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1117                 if (prev_state != wpa_s->wpa_state)
1118                         wpa_supplicant_set_state(wpa_s, prev_state);
1119                 return ret;
1120         }
1121
1122         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1123         if (ssid || !wpa_s->first_sched_scan) {
1124                 wpa_s->sched_scan_timed_out = 0;
1125                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1126                                        wpa_supplicant_sched_scan_timeout,
1127                                        wpa_s, NULL);
1128                 wpa_s->first_sched_scan = 0;
1129                 wpa_s->sched_scan_timeout /= 2;
1130                 wpa_s->sched_scan_interval *= 2;
1131                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1132                         wpa_s->sched_scan_interval = 10;
1133                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1134                 }
1135         }
1136
1137         /* If there is no more ssids, start next time from the beginning */
1138         if (!ssid)
1139                 wpa_s->prev_sched_ssid = NULL;
1140
1141         return 0;
1142 }
1143
1144
1145 /**
1146  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1147  * @wpa_s: Pointer to wpa_supplicant data
1148  *
1149  * This function is used to cancel a scan request scheduled with
1150  * wpa_supplicant_req_scan().
1151  */
1152 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1153 {
1154         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1155         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1156         wpas_p2p_continue_after_scan(wpa_s);
1157 }
1158
1159
1160 /**
1161  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1162  * @wpa_s: Pointer to wpa_supplicant data
1163  *
1164  * This function is used to stop a periodic scheduled scan.
1165  */
1166 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1167 {
1168         if (!wpa_s->sched_scanning)
1169                 return;
1170
1171         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1172         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1173         wpa_supplicant_stop_sched_scan(wpa_s);
1174 }
1175
1176
1177 /**
1178  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1179  * @wpa_s: Pointer to wpa_supplicant data
1180  * @scanning: Whether scanning is currently in progress
1181  *
1182  * This function is to generate scanning notifycations. It is called whenever
1183  * there may have been a change in scanning (scan started, completed, stopped).
1184  * wpas_notify_scanning() is called whenever the scanning state changed from the
1185  * previously notified state.
1186  */
1187 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1188                                     int scanning)
1189 {
1190         if (wpa_s->scanning != scanning) {
1191                 wpa_s->scanning = scanning;
1192                 wpas_notify_scanning(wpa_s);
1193         }
1194 }
1195
1196
1197 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1198 {
1199         int rate = 0;
1200         const u8 *ie;
1201         int i;
1202
1203         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1204         for (i = 0; ie && i < ie[1]; i++) {
1205                 if ((ie[i + 2] & 0x7f) > rate)
1206                         rate = ie[i + 2] & 0x7f;
1207         }
1208
1209         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1210         for (i = 0; ie && i < ie[1]; i++) {
1211                 if ((ie[i + 2] & 0x7f) > rate)
1212                         rate = ie[i + 2] & 0x7f;
1213         }
1214
1215         return rate;
1216 }
1217
1218
1219 /**
1220  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1221  * @res: Scan result entry
1222  * @ie: Information element identitifier (WLAN_EID_*)
1223  * Returns: Pointer to the information element (id field) or %NULL if not found
1224  *
1225  * This function returns the first matching information element in the scan
1226  * result.
1227  */
1228 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1229 {
1230         const u8 *end, *pos;
1231
1232         pos = (const u8 *) (res + 1);
1233         end = pos + res->ie_len;
1234
1235         while (pos + 1 < end) {
1236                 if (pos + 2 + pos[1] > end)
1237                         break;
1238                 if (pos[0] == ie)
1239                         return pos;
1240                 pos += 2 + pos[1];
1241         }
1242
1243         return NULL;
1244 }
1245
1246
1247 /**
1248  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1249  * @res: Scan result entry
1250  * @vendor_type: Vendor type (four octets starting the IE payload)
1251  * Returns: Pointer to the information element (id field) or %NULL if not found
1252  *
1253  * This function returns the first matching information element in the scan
1254  * result.
1255  */
1256 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1257                                   u32 vendor_type)
1258 {
1259         const u8 *end, *pos;
1260
1261         pos = (const u8 *) (res + 1);
1262         end = pos + res->ie_len;
1263
1264         while (pos + 1 < end) {
1265                 if (pos + 2 + pos[1] > end)
1266                         break;
1267                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1268                     vendor_type == WPA_GET_BE32(&pos[2]))
1269                         return pos;
1270                 pos += 2 + pos[1];
1271         }
1272
1273         return NULL;
1274 }
1275
1276
1277 /**
1278  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1279  * @res: Scan result entry
1280  * @vendor_type: Vendor type (four octets starting the IE payload)
1281  * Returns: Pointer to the information element payload or %NULL if not found
1282  *
1283  * This function returns concatenated payload of possibly fragmented vendor
1284  * specific information elements in the scan result. The caller is responsible
1285  * for freeing the returned buffer.
1286  */
1287 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1288                                              u32 vendor_type)
1289 {
1290         struct wpabuf *buf;
1291         const u8 *end, *pos;
1292
1293         buf = wpabuf_alloc(res->ie_len);
1294         if (buf == NULL)
1295                 return NULL;
1296
1297         pos = (const u8 *) (res + 1);
1298         end = pos + res->ie_len;
1299
1300         while (pos + 1 < end) {
1301                 if (pos + 2 + pos[1] > end)
1302                         break;
1303                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1304                     vendor_type == WPA_GET_BE32(&pos[2]))
1305                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1306                 pos += 2 + pos[1];
1307         }
1308
1309         if (wpabuf_len(buf) == 0) {
1310                 wpabuf_free(buf);
1311                 buf = NULL;
1312         }
1313
1314         return buf;
1315 }
1316
1317
1318 /*
1319  * Channels with a great SNR can operate at full rate. What is a great SNR?
1320  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1321  * rule of thumb is that any SNR above 20 is good." This one
1322  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1323  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1324  * conservative value.
1325  */
1326 #define GREAT_SNR 30
1327
1328 /* Compare function for sorting scan results. Return >0 if @b is considered
1329  * better. */
1330 static int wpa_scan_result_compar(const void *a, const void *b)
1331 {
1332 #define IS_5GHZ(n) (n > 4000)
1333 #define MIN(a,b) a < b ? a : b
1334         struct wpa_scan_res **_wa = (void *) a;
1335         struct wpa_scan_res **_wb = (void *) b;
1336         struct wpa_scan_res *wa = *_wa;
1337         struct wpa_scan_res *wb = *_wb;
1338         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1339         int snr_a, snr_b;
1340
1341         /* WPA/WPA2 support preferred */
1342         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1343                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1344         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1345                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1346
1347         if (wpa_b && !wpa_a)
1348                 return 1;
1349         if (!wpa_b && wpa_a)
1350                 return -1;
1351
1352         /* privacy support preferred */
1353         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1354             (wb->caps & IEEE80211_CAP_PRIVACY))
1355                 return 1;
1356         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1357             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1358                 return -1;
1359
1360         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1361             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1362                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1363                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1364         } else {
1365                 /* Not suitable information to calculate SNR, so use level */
1366                 snr_a = wa->level;
1367                 snr_b = wb->level;
1368         }
1369
1370         /* best/max rate preferred if SNR close enough */
1371         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1372             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1373                 maxrate_a = wpa_scan_get_max_rate(wa);
1374                 maxrate_b = wpa_scan_get_max_rate(wb);
1375                 if (maxrate_a != maxrate_b)
1376                         return maxrate_b - maxrate_a;
1377                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1378                         return IS_5GHZ(wa->freq) ? -1 : 1;
1379         }
1380
1381         /* use freq for channel preference */
1382
1383         /* all things being equal, use SNR; if SNRs are
1384          * identical, use quality values since some drivers may only report
1385          * that value and leave the signal level zero */
1386         if (snr_b == snr_a)
1387                 return wb->qual - wa->qual;
1388         return snr_b - snr_a;
1389 #undef MIN
1390 #undef IS_5GHZ
1391 }
1392
1393
1394 #ifdef CONFIG_WPS
1395 /* Compare function for sorting scan results when searching a WPS AP for
1396  * provisioning. Return >0 if @b is considered better. */
1397 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1398 {
1399         struct wpa_scan_res **_wa = (void *) a;
1400         struct wpa_scan_res **_wb = (void *) b;
1401         struct wpa_scan_res *wa = *_wa;
1402         struct wpa_scan_res *wb = *_wb;
1403         int uses_wps_a, uses_wps_b;
1404         struct wpabuf *wps_a, *wps_b;
1405         int res;
1406
1407         /* Optimization - check WPS IE existence before allocated memory and
1408          * doing full reassembly. */
1409         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1410         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1411         if (uses_wps_a && !uses_wps_b)
1412                 return -1;
1413         if (!uses_wps_a && uses_wps_b)
1414                 return 1;
1415
1416         if (uses_wps_a && uses_wps_b) {
1417                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1418                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1419                 res = wps_ap_priority_compar(wps_a, wps_b);
1420                 wpabuf_free(wps_a);
1421                 wpabuf_free(wps_b);
1422                 if (res)
1423                         return res;
1424         }
1425
1426         /*
1427          * Do not use current AP security policy as a sorting criteria during
1428          * WPS provisioning step since the AP may get reconfigured at the
1429          * completion of provisioning.
1430          */
1431
1432         /* all things being equal, use signal level; if signal levels are
1433          * identical, use quality values since some drivers may only report
1434          * that value and leave the signal level zero */
1435         if (wb->level == wa->level)
1436                 return wb->qual - wa->qual;
1437         return wb->level - wa->level;
1438 }
1439 #endif /* CONFIG_WPS */
1440
1441
1442 static void dump_scan_res(struct wpa_scan_results *scan_res)
1443 {
1444 #ifndef CONFIG_NO_STDOUT_DEBUG
1445         size_t i;
1446
1447         if (scan_res->res == NULL || scan_res->num == 0)
1448                 return;
1449
1450         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1451
1452         for (i = 0; i < scan_res->num; i++) {
1453                 struct wpa_scan_res *r = scan_res->res[i];
1454                 u8 *pos;
1455                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1456                     == WPA_SCAN_LEVEL_DBM) {
1457                         int snr = r->level - r->noise;
1458                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1459                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1460                                    "age=%u",
1461                                    MAC2STR(r->bssid), r->freq, r->qual,
1462                                    r->noise, r->level, snr,
1463                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1464                                    r->age);
1465                 } else {
1466                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1467                                    "noise=%d level=%d flags=0x%x age=%u",
1468                                    MAC2STR(r->bssid), r->freq, r->qual,
1469                                    r->noise, r->level, r->flags, r->age);
1470                 }
1471                 pos = (u8 *) (r + 1);
1472                 if (r->ie_len)
1473                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1474                 pos += r->ie_len;
1475                 if (r->beacon_ie_len)
1476                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1477                                     pos, r->beacon_ie_len);
1478         }
1479 #endif /* CONFIG_NO_STDOUT_DEBUG */
1480 }
1481
1482
1483 /**
1484  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1485  * @wpa_s: Pointer to wpa_supplicant data
1486  * @bssid: BSSID to check
1487  * Returns: 0 if the BSSID is filtered or 1 if not
1488  *
1489  * This function is used to filter out specific BSSIDs from scan reslts mainly
1490  * for testing purposes (SET bssid_filter ctrl_iface command).
1491  */
1492 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1493                                       const u8 *bssid)
1494 {
1495         size_t i;
1496
1497         if (wpa_s->bssid_filter == NULL)
1498                 return 1;
1499
1500         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1501                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1502                               ETH_ALEN) == 0)
1503                         return 1;
1504         }
1505
1506         return 0;
1507 }
1508
1509
1510 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1511                             struct wpa_scan_results *res)
1512 {
1513         size_t i, j;
1514
1515         if (wpa_s->bssid_filter == NULL)
1516                 return;
1517
1518         for (i = 0, j = 0; i < res->num; i++) {
1519                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1520                                                       res->res[i]->bssid)) {
1521                         res->res[j++] = res->res[i];
1522                 } else {
1523                         os_free(res->res[i]);
1524                         res->res[i] = NULL;
1525                 }
1526         }
1527
1528         if (res->num != j) {
1529                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1530                            (int) (res->num - j));
1531                 res->num = j;
1532         }
1533 }
1534
1535
1536 /**
1537  * wpa_supplicant_get_scan_results - Get scan results
1538  * @wpa_s: Pointer to wpa_supplicant data
1539  * @info: Information about what was scanned or %NULL if not available
1540  * @new_scan: Whether a new scan was performed
1541  * Returns: Scan results, %NULL on failure
1542  *
1543  * This function request the current scan results from the driver and updates
1544  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1545  * results with wpa_scan_results_free().
1546  */
1547 struct wpa_scan_results *
1548 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1549                                 struct scan_info *info, int new_scan)
1550 {
1551         struct wpa_scan_results *scan_res;
1552         size_t i;
1553         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1554
1555         scan_res = wpa_drv_get_scan_results2(wpa_s);
1556         if (scan_res == NULL) {
1557                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1558                 return NULL;
1559         }
1560         if (scan_res->fetch_time.sec == 0) {
1561                 /*
1562                  * Make sure we have a valid timestamp if the driver wrapper
1563                  * does not set this.
1564                  */
1565                 os_get_time(&scan_res->fetch_time);
1566         }
1567         filter_scan_res(wpa_s, scan_res);
1568
1569 #ifdef CONFIG_WPS
1570         if (wpas_wps_in_progress(wpa_s)) {
1571                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1572                         "provisioning rules");
1573                 compar = wpa_scan_result_wps_compar;
1574         }
1575 #endif /* CONFIG_WPS */
1576
1577         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1578               compar);
1579         dump_scan_res(scan_res);
1580
1581         wpa_bss_update_start(wpa_s);
1582         for (i = 0; i < scan_res->num; i++)
1583                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1584                                         &scan_res->fetch_time);
1585         wpa_bss_update_end(wpa_s, info, new_scan);
1586
1587         return scan_res;
1588 }
1589
1590
1591 /**
1592  * wpa_supplicant_update_scan_results - Update scan results from the driver
1593  * @wpa_s: Pointer to wpa_supplicant data
1594  * Returns: 0 on success, -1 on failure
1595  *
1596  * This function updates the BSS table within wpa_supplicant based on the
1597  * currently available scan results from the driver without requesting a new
1598  * scan. This is used in cases where the driver indicates an association
1599  * (including roaming within ESS) and wpa_supplicant does not yet have the
1600  * needed information to complete the connection (e.g., to perform validation
1601  * steps in 4-way handshake).
1602  */
1603 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1604 {
1605         struct wpa_scan_results *scan_res;
1606         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1607         if (scan_res == NULL)
1608                 return -1;
1609         wpa_scan_results_free(scan_res);
1610
1611         return 0;
1612 }
1613
1614
1615 /**
1616  * scan_only_handler - Reports scan results
1617  */
1618 void scan_only_handler(struct wpa_supplicant *wpa_s,
1619                        struct wpa_scan_results *scan_res)
1620 {
1621         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1622         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1623         wpas_notify_scan_results(wpa_s);
1624         wpas_notify_scan_done(wpa_s, 1);
1625 }
1626
1627
1628 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1629 {
1630         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1631 }