wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, 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 "config.h"
  15 #include "wpa_supplicant_i.h"
  16 #include "driver_i.h"
  17 #include "wps_supplicant.h"
  18 #include "p2p_supplicant.h"
  19 #include "p2p/p2p.h"
  20 #include "hs20_supplicant.h"
  21 #include "notify.h"
  22 #include "bss.h"
  23 #include "scan.h"
  24
  25
  26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  27 {
  28         struct wpa_ssid *ssid;
  29         union wpa_event_data data;
  30
  31         ssid = wpa_supplicant_get_ssid(wpa_s);
  32         if (ssid == NULL)
  33                 return;
  34
  35         if (wpa_s->current_ssid == NULL) {
  36                 wpa_s->current_ssid = ssid;
  37                 if (wpa_s->current_ssid != NULL)
  38                         wpas_notify_network_changed(wpa_s);
  39         }
  40         wpa_supplicant_initiate_eapol(wpa_s);
  41         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  42                 "network - generating associated event");
  43         os_memset(&data, 0, sizeof(data));
  44         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  45 }
  46
  47
  48 #ifdef CONFIG_WPS
  49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  50                            enum wps_request_type *req_type)
  51 {
  52         struct wpa_ssid *ssid;
  53         int wps = 0;
  54
  55         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  56                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  57                         continue;
  58
  59                 wps = 1;
  60                 *req_type = wpas_wps_get_req_type(ssid);
  61                 if (!ssid->eap.phase1)
  62                         continue;
  63
  64                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  65                         return 2;
  66         }
  67
  68 #ifdef CONFIG_P2P
  69         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
  70             !wpa_s->conf->p2p_disabled) {
  71                 wpa_s->wps->dev.p2p = 1;
  72                 if (!wps) {
  73                         wps = 1;
  74                         *req_type = WPS_REQ_ENROLLEE_INFO;
  75                 }
  76         }
  77 #endif /* CONFIG_P2P */
  78
  79         return wps;
  80 }
  81 #endif /* CONFIG_WPS */
  82
  83
  84 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  85 {
  86         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  87         int count = 0, disabled = 0;
  88         while (ssid) {
  89                 if (!wpas_network_disabled(wpa_s, ssid))
  90                         count++;
  91                 else
  92                         disabled++;
  93                 ssid = ssid->next;
  94         }
  95         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
  96             wpa_s->conf->auto_interworking)
  97                 count++;
  98         if (count == 0 && disabled > 0) {
  99                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
 100                         "networks)", disabled);
 101         }
 102         return count;
 103 }
 104
 105
 106 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 107                                      struct wpa_ssid *ssid)
 108 {
 109         while (ssid) {
 110                 if (!wpas_network_disabled(wpa_s, ssid))
 111                         break;
 112                 ssid = ssid->next;
 113         }
 114
 115         /* ap_scan=2 mode - try to associate with each SSID. */
 116         if (ssid == NULL) {
 117                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 118                         "end of scan list - go back to beginning");
 119                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 120                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 121                 return;
 122         }
 123         if (ssid->next) {
 124                 /* Continue from the next SSID on the next attempt. */
 125                 wpa_s->prev_scan_ssid = ssid;
 126         } else {
 127                 /* Start from the beginning of the SSID list. */
 128                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 129         }
 130         wpa_supplicant_associate(wpa_s, NULL, ssid);
 131 }
 132
 133
 134 static int int_array_len(const int *a)
 135 {
 136         int i;
 137         for (i = 0; a && a[i]; i++)
 138                 ;
 139         return i;
 140 }
 141
 142
 143 static void int_array_concat(int **res, const int *a)
 144 {
 145         int reslen, alen, i;
 146         int *n;
 147
 148         reslen = int_array_len(*res);
 149         alen = int_array_len(a);
 150
 151         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 152         if (n == NULL) {
 153                 os_free(*res);
 154                 *res = NULL;
 155                 return;
 156         }
 157         for (i = 0; i <= alen; i++)
 158                 n[reslen + i] = a[i];
 159         *res = n;
 160 }
 161
 162
 163 static int freq_cmp(const void *a, const void *b)
 164 {
 165         int _a = *(int *) a;
 166         int _b = *(int *) b;
 167
 168         if (_a == 0)
 169                 return 1;
 170         if (_b == 0)
 171                 return -1;
 172         return _a - _b;
 173 }
 174
 175
 176 static void int_array_sort_unique(int *a)
 177 {
 178         int alen;
 179         int i, j;
 180
 181         if (a == NULL)
 182                 return;
 183
 184         alen = int_array_len(a);
 185         qsort(a, alen, sizeof(int), freq_cmp);
 186
 187         i = 0;
 188         j = 1;
 189         while (a[i] && a[j]) {
 190                 if (a[i] == a[j]) {
 191                         j++;
 192                         continue;
 193                 }
 194                 a[++i] = a[j++];
 195         }
 196         if (a[i])
 197                 i++;
 198         a[i] = 0;
 199 }
 200
 201
 202 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 203                                 struct wpa_driver_scan_params *params)
 204 {
 205         int ret;
 206
 207         wpa_supplicant_notify_scanning(wpa_s, 1);
 208
 209         ret = wpa_drv_scan(wpa_s, params);
 210         if (ret) {
 211                 wpa_supplicant_notify_scanning(wpa_s, 0);
 212                 wpas_notify_scan_done(wpa_s, 0);
 213         } else {
 214                 wpa_s->scan_runs++;
 215                 wpa_s->normal_scans++;
 216         }
 217
 218         return ret;
 219 }
 220
 221
 222 static void
 223 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 224 {
 225         struct wpa_supplicant *wpa_s = eloop_ctx;
 226
 227         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 228
 229         if (wpa_supplicant_req_sched_scan(wpa_s))
 230                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 231 }
 232
 233
 234 static void
 235 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 236 {
 237         struct wpa_supplicant *wpa_s = eloop_ctx;
 238
 239         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 240
 241         wpa_s->sched_scan_timed_out = 1;
 242         wpa_supplicant_cancel_sched_scan(wpa_s);
 243 }
 244
 245
 246 static int
 247 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 248                                 struct wpa_driver_scan_params *params,
 249                                 int interval)
 250 {
 251         int ret;
 252
 253         wpa_supplicant_notify_scanning(wpa_s, 1);
 254         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 255         if (ret)
 256                 wpa_supplicant_notify_scanning(wpa_s, 0);
 257         else
 258                 wpa_s->sched_scanning = 1;
 259
 260         return ret;
 261 }
 262
 263
 264 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 265 {
 266         int ret;
 267
 268         ret = wpa_drv_stop_sched_scan(wpa_s);
 269         if (ret) {
 270                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 271                 /* TODO: what to do if stopping fails? */
 272                 return -1;
 273         }
 274
 275         return ret;
 276 }
 277
 278
 279 static struct wpa_driver_scan_filter *
 280 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 281 {
 282         struct wpa_driver_scan_filter *ssids;
 283         struct wpa_ssid *ssid;
 284         size_t count;
 285
 286         *num_ssids = 0;
 287         if (!conf->filter_ssids)
 288                 return NULL;
 289
 290         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 291                 if (ssid->ssid && ssid->ssid_len)
 292                         count++;
 293         }
 294         if (count == 0)
 295                 return NULL;
 296         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 297         if (ssids == NULL)
 298                 return NULL;
 299
 300         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 301                 if (!ssid->ssid || !ssid->ssid_len)
 302                         continue;
 303                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 304                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 305                 (*num_ssids)++;
 306         }
 307
 308         return ssids;
 309 }
 310
 311
 312 static void wpa_supplicant_optimize_freqs(
 313         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 314 {
 315 #ifdef CONFIG_P2P
 316         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 317             wpa_s->go_params) {
 318                 /* Optimize provisioning state scan based on GO information */
 319                 if (wpa_s->p2p_in_provisioning < 5 &&
 320                     wpa_s->go_params->freq > 0) {
 321                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 322                                 "preferred frequency %d MHz",
 323                                 wpa_s->go_params->freq);
 324                         params->freqs = os_zalloc(2 * sizeof(int));
 325                         if (params->freqs)
 326                                 params->freqs[0] = wpa_s->go_params->freq;
 327                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 328                            wpa_s->go_params->freq_list[0]) {
 329                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 330                                 "channels");
 331                         int_array_concat(&params->freqs,
 332                                          wpa_s->go_params->freq_list);
 333                         if (params->freqs)
 334                                 int_array_sort_unique(params->freqs);
 335                 }
 336                 wpa_s->p2p_in_provisioning++;
 337         }
 338 #endif /* CONFIG_P2P */
 339
 340 #ifdef CONFIG_WPS
 341         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 342                 /*
 343                  * Optimize post-provisioning scan based on channel used
 344                  * during provisioning.
 345                  */
 346                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 347                         "that was used during provisioning", wpa_s->wps_freq);
 348                 params->freqs = os_zalloc(2 * sizeof(int));
 349                 if (params->freqs)
 350                         params->freqs[0] = wpa_s->wps_freq;
 351                 wpa_s->after_wps--;
 352         }
 353
 354         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 355         {
 356                 /* Optimize provisioning scan based on already known channel */
 357                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 358                         wpa_s->wps_freq);
 359                 params->freqs = os_zalloc(2 * sizeof(int));
 360                 if (params->freqs)
 361                         params->freqs[0] = wpa_s->wps_freq;
 362                 wpa_s->known_wps_freq = 0; /* only do this once */
 363         }
 364 #endif /* CONFIG_WPS */
 365 }
 366
 367
 368 #ifdef CONFIG_INTERWORKING
 369 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 370                                            struct wpabuf *buf)
 371 {
 372         if (wpa_s->conf->interworking == 0)
 373                 return;
 374
 375         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 376         wpabuf_put_u8(buf, 4);
 377         wpabuf_put_u8(buf, 0x00);
 378         wpabuf_put_u8(buf, 0x00);
 379         wpabuf_put_u8(buf, 0x00);
 380         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 381
 382         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 383         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 384                       1 + ETH_ALEN);
 385         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 386         /* No Venue Info */
 387         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 388                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 389 }
 390 #endif /* CONFIG_INTERWORKING */
 391
 392
 393 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 394 {
 395         struct wpabuf *extra_ie = NULL;
 396 #ifdef CONFIG_WPS
 397         int wps = 0;
 398         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 399 #endif /* CONFIG_WPS */
 400
 401 #ifdef CONFIG_INTERWORKING
 402         if (wpa_s->conf->interworking &&
 403             wpabuf_resize(&extra_ie, 100) == 0)
 404                 wpas_add_interworking_elements(wpa_s, extra_ie);
 405 #endif /* CONFIG_INTERWORKING */
 406
 407 #ifdef CONFIG_WPS
 408         wps = wpas_wps_in_use(wpa_s, &req_type);
 409
 410         if (wps) {
 411                 struct wpabuf *wps_ie;
 412                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 413                                                 DEV_PW_DEFAULT,
 414                                                 &wpa_s->wps->dev,
 415                                                 wpa_s->wps->uuid, req_type,
 416                                                 0, NULL);
 417                 if (wps_ie) {
 418                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 419                                 wpabuf_put_buf(extra_ie, wps_ie);
 420                         wpabuf_free(wps_ie);
 421                 }
 422         }
 423
 424 #ifdef CONFIG_P2P
 425         if (wps) {
 426                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 427                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 428                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 429         }
 430 #endif /* CONFIG_P2P */
 431
 432 #endif /* CONFIG_WPS */
 433
 434         return extra_ie;
 435 }
 436
 437
 438 #ifdef CONFIG_P2P
 439
 440 /*
 441  * Check whether there are any enabled networks or credentials that could be
 442  * used for a non-P2P connection.
 443  */
 444 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 445 {
 446         struct wpa_ssid *ssid;
 447
 448         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 449                 if (wpas_network_disabled(wpa_s, ssid))
 450                         continue;
 451                 if (!ssid->p2p_group)
 452                         return 1;
 453         }
 454
 455         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 456             wpa_s->conf->auto_interworking)
 457                 return 1;
 458
 459         return 0;
 460 }
 461
 462
 463 /*
 464  * Find the operating frequency of any other virtual interface that is using
 465  * the same radio concurrently.
 466  */
 467 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
 468 {
 469         const char *rn, *rn2;
 470         struct wpa_supplicant *ifs;
 471         u8 bssid[ETH_ALEN];
 472
 473         if (!wpa_s->driver->get_radio_name)
 474                 return -1;
 475
 476         rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
 477         if (rn == NULL || rn[0] == '\0')
 478                 return -1;
 479
 480         for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
 481                 if (ifs == wpa_s || !ifs->driver->get_radio_name)
 482                         continue;
 483
 484                 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
 485                 if (!rn2 || os_strcmp(rn, rn2) != 0)
 486                         continue;
 487
 488                 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
 489                         continue;
 490
 491                 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
 492                     ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
 493                         return ifs->current_ssid->frequency;
 494                 if (wpa_drv_get_bssid(ifs, bssid) == 0)
 495                         return ifs->assoc_freq;
 496         }
 497
 498         return 0;
 499 }
 500
 501 #endif /* CONFIG_P2P */
 502
 503
 504 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 505 {
 506         struct wpa_supplicant *wpa_s = eloop_ctx;
 507         struct wpa_ssid *ssid;
 508         int scan_req = 0, ret;
 509         struct wpabuf *extra_ie = NULL;
 510         struct wpa_driver_scan_params params;
 511         struct wpa_driver_scan_params *scan_params;
 512         size_t max_ssids;
 513         enum wpa_states prev_state;
 514
 515         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 516                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 517                 return;
 518         }
 519
 520         if (wpa_s->disconnected && !wpa_s->scan_req) {
 521                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 522                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 523                 return;
 524         }
 525
 526         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 527             !wpa_s->scan_req) {
 528                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 529                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 530 #ifdef CONFIG_P2P
 531                 wpa_s->sta_scan_pending = 0;
 532 #endif /* CONFIG_P2P */
 533                 return;
 534         }
 535
 536         if (wpa_s->conf->ap_scan != 0 &&
 537             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 538                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 539                         "overriding ap_scan configuration");
 540                 wpa_s->conf->ap_scan = 0;
 541                 wpas_notify_ap_scan_changed(wpa_s);
 542         }
 543
 544         if (wpa_s->conf->ap_scan == 0) {
 545                 wpa_supplicant_gen_assoc_event(wpa_s);
 546                 return;
 547         }
 548
 549 #ifdef CONFIG_P2P
 550         if (wpas_p2p_in_progress(wpa_s)) {
 551                 if (wpa_s->sta_scan_pending &&
 552                     wpas_p2p_in_progress(wpa_s) == 2 &&
 553                     wpa_s->global->p2p_cb_on_scan_complete) {
 554                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 555                                 "mode scan during P2P search");
 556                 } else {
 557                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 558                                 "while P2P operation is in progress");
 559                         wpa_s->sta_scan_pending = 1;
 560                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 561                         return;
 562                 }
 563         }
 564 #endif /* CONFIG_P2P */
 565
 566         if (wpa_s->conf->ap_scan == 2)
 567                 max_ssids = 1;
 568         else {
 569                 max_ssids = wpa_s->max_scan_ssids;
 570                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 571                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 572         }
 573
 574         scan_req = wpa_s->scan_req;
 575         wpa_s->scan_req = 0;
 576
 577         os_memset(&params, 0, sizeof(params));
 578
 579         prev_state = wpa_s->wpa_state;
 580         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 581             wpa_s->wpa_state == WPA_INACTIVE)
 582                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 583
 584         /*
 585          * If autoscan has set its own scanning parameters
 586          */
 587         if (wpa_s->autoscan_params != NULL) {
 588                 scan_params = wpa_s->autoscan_params;
 589                 goto scan;
 590         }
 591
 592         if (scan_req != 2 && wpa_s->connect_without_scan) {
 593                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 594                         if (ssid == wpa_s->connect_without_scan)
 595                                 break;
 596                 }
 597                 wpa_s->connect_without_scan = NULL;
 598                 if (ssid) {
 599                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 600                                    "without scan step");
 601                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 602                         return;
 603                 }
 604         }
 605
 606 #ifdef CONFIG_P2P
 607         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 608             wpa_s->go_params) {
 609                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 610                            "P2P group formation");
 611                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 612                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 613                 params.num_ssids = 1;
 614                 goto ssid_list_set;
 615         }
 616 #endif /* CONFIG_P2P */
 617
 618         /* Find the starting point from which to continue scanning */
 619         ssid = wpa_s->conf->ssid;
 620         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 621                 while (ssid) {
 622                         if (ssid == wpa_s->prev_scan_ssid) {
 623                                 ssid = ssid->next;
 624                                 break;
 625                         }
 626                         ssid = ssid->next;
 627                 }
 628         }
 629
 630         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 631                 wpa_s->connect_without_scan = NULL;
 632                 wpa_s->prev_scan_wildcard = 0;
 633                 wpa_supplicant_assoc_try(wpa_s, ssid);
 634                 return;
 635         } else if (wpa_s->conf->ap_scan == 2) {
 636                 /*
 637                  * User-initiated scan request in ap_scan == 2; scan with
 638                  * wildcard SSID.
 639                  */
 640                 ssid = NULL;
 641         } else {
 642                 struct wpa_ssid *start = ssid, *tssid;
 643                 int freqs_set = 0;
 644                 if (ssid == NULL && max_ssids > 1)
 645                         ssid = wpa_s->conf->ssid;
 646                 while (ssid) {
 647                         if (!wpas_network_disabled(wpa_s, ssid) &&
 648                             ssid->scan_ssid) {
 649                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 650                                                   ssid->ssid, ssid->ssid_len);
 651                                 params.ssids[params.num_ssids].ssid =
 652                                         ssid->ssid;
 653                                 params.ssids[params.num_ssids].ssid_len =
 654                                         ssid->ssid_len;
 655                                 params.num_ssids++;
 656                                 if (params.num_ssids + 1 >= max_ssids)
 657                                         break;
 658                         }
 659                         ssid = ssid->next;
 660                         if (ssid == start)
 661                                 break;
 662                         if (ssid == NULL && max_ssids > 1 &&
 663                             start != wpa_s->conf->ssid)
 664                                 ssid = wpa_s->conf->ssid;
 665                 }
 666
 667                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 668                         if (wpas_network_disabled(wpa_s, tssid))
 669                                 continue;
 670                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 671                                 int_array_concat(&params.freqs,
 672                                                  tssid->scan_freq);
 673                         } else {
 674                                 os_free(params.freqs);
 675                                 params.freqs = NULL;
 676                         }
 677                         freqs_set = 1;
 678                 }
 679                 int_array_sort_unique(params.freqs);
 680         }
 681
 682         if (ssid && max_ssids == 1) {
 683                 /*
 684                  * If the driver is limited to 1 SSID at a time interleave
 685                  * wildcard SSID scans with specific SSID scans to avoid
 686                  * waiting a long time for a wildcard scan.
 687                  */
 688                 if (!wpa_s->prev_scan_wildcard) {
 689                         params.ssids[0].ssid = NULL;
 690                         params.ssids[0].ssid_len = 0;
 691                         wpa_s->prev_scan_wildcard = 1;
 692                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 693                                 "wildcard SSID (Interleave with specific)");
 694                 } else {
 695                         wpa_s->prev_scan_ssid = ssid;
 696                         wpa_s->prev_scan_wildcard = 0;
 697                         wpa_dbg(wpa_s, MSG_DEBUG,
 698                                 "Starting AP scan for specific SSID: %s",
 699                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 700                 }
 701         } else if (ssid) {
 702                 /* max_ssids > 1 */
 703
 704                 wpa_s->prev_scan_ssid = ssid;
 705                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 706                         "the scan request");
 707                 params.num_ssids++;
 708         } else {
 709                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 710                 params.num_ssids++;
 711                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 712                         "SSID");
 713         }
 714 #ifdef CONFIG_P2P
 715 ssid_list_set:
 716 #endif /* CONFIG_P2P */
 717
 718         wpa_supplicant_optimize_freqs(wpa_s, &params);
 719         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 720
 721 #ifdef CONFIG_HS20
 722         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 723                 wpas_hs20_add_indication(extra_ie);
 724 #endif /* CONFIG_HS20 */
 725
 726         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 727                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 728                         "generated frequency list");
 729                 params.freqs = wpa_s->next_scan_freqs;
 730         } else
 731                 os_free(wpa_s->next_scan_freqs);
 732         wpa_s->next_scan_freqs = NULL;
 733
 734         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 735                 wpa_s->conf, &params.num_filter_ssids);
 736         if (extra_ie) {
 737                 params.extra_ies = wpabuf_head(extra_ie);
 738                 params.extra_ies_len = wpabuf_len(extra_ie);
 739         }
 740
 741 #ifdef CONFIG_P2P
 742         if (wpa_s->p2p_in_provisioning ||
 743             (wpa_s->show_group_started && wpa_s->go_params)) {
 744                 /*
 745                  * The interface may not yet be in P2P mode, so we have to
 746                  * explicitly request P2P probe to disable CCK rates.
 747                  */
 748                 params.p2p_probe = 1;
 749         }
 750 #endif /* CONFIG_P2P */
 751
 752         scan_params = &params;
 753
 754 scan:
 755 #ifdef CONFIG_P2P
 756         /*
 757          * If the driver does not support multi-channel concurrency and a
 758          * virtual interface that shares the same radio with the wpa_s interface
 759          * is operating there may not be need to scan other channels apart from
 760          * the current operating channel on the other virtual interface. Filter
 761          * out other channels in case we are trying to find a connection for a
 762          * station interface when we are not configured to prefer station
 763          * connection and a concurrent operation is already in process.
 764          */
 765         if (wpa_s->scan_for_connection && !scan_req &&
 766             !scan_params->freqs && !params.freqs &&
 767             wpas_is_p2p_prioritized(wpa_s) &&
 768             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
 769             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 770             non_p2p_network_enabled(wpa_s)) {
 771                 int freq = shared_vif_oper_freq(wpa_s);
 772                 if (freq > 0) {
 773                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
 774                                 "operating channel (%d MHz) since driver does "
 775                                 "not support multi-channel concurrency", freq);
 776                         params.freqs = os_zalloc(sizeof(int) * 2);
 777                         if (params.freqs)
 778                                 params.freqs[0] = freq;
 779                         scan_params->freqs = params.freqs;
 780                 }
 781         }
 782 #endif /* CONFIG_P2P */
 783
 784         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 785
 786         wpabuf_free(extra_ie);
 787         os_free(params.freqs);
 788         os_free(params.filter_ssids);
 789
 790         if (ret) {
 791                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 792                 if (prev_state != wpa_s->wpa_state)
 793                         wpa_supplicant_set_state(wpa_s, prev_state);
 794                 /* Restore scan_req since we will try to scan again */
 795                 wpa_s->scan_req = scan_req;
 796                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 797         } else {
 798                 wpa_s->scan_for_connection = 0;
 799         }
 800 }
 801
 802
 803 /**
 804  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 805  * @wpa_s: Pointer to wpa_supplicant data
 806  * @sec: Number of seconds after which to scan
 807  * @usec: Number of microseconds after which to scan
 808  *
 809  * This function is used to schedule a scan for neighboring access points after
 810  * the specified time.
 811  */
 812 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 813 {
 814         /* If there's at least one network that should be specifically scanned
 815          * then don't cancel the scan and reschedule.  Some drivers do
 816          * background scanning which generates frequent scan results, and that
 817          * causes the specific SSID scan to get continually pushed back and
 818          * never happen, which causes hidden APs to never get probe-scanned.
 819          */
 820         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 821             wpa_s->conf->ap_scan == 1) {
 822                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 823
 824                 while (ssid) {
 825                         if (!wpas_network_disabled(wpa_s, ssid) &&
 826                             ssid->scan_ssid)
 827                                 break;
 828                         ssid = ssid->next;
 829                 }
 830                 if (ssid) {
 831                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 832                                 "ensure that specific SSID scans occur");
 833                         return;
 834                 }
 835         }
 836
 837         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 838                 sec, usec);
 839         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 840         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 841 }
 842
 843
 844 /**
 845  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 846  * @wpa_s: Pointer to wpa_supplicant data
 847  * @sec: Number of seconds after which to scan
 848  * @usec: Number of microseconds after which to scan
 849  *
 850  * This function is used to schedule periodic scans for neighboring
 851  * access points after the specified time.
 852  */
 853 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 854                                       int sec, int usec)
 855 {
 856         if (!wpa_s->sched_scan_supported)
 857                 return -1;
 858
 859         eloop_register_timeout(sec, usec,
 860                                wpa_supplicant_delayed_sched_scan_timeout,
 861                                wpa_s, NULL);
 862
 863         return 0;
 864 }
 865
 866
 867 /**
 868  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 869  * @wpa_s: Pointer to wpa_supplicant data
 870  *
 871  * This function is used to schedule periodic scans for neighboring
 872  * access points repeating the scan continuously.
 873  */
 874 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 875 {
 876         struct wpa_driver_scan_params params;
 877         struct wpa_driver_scan_params *scan_params;
 878         enum wpa_states prev_state;
 879         struct wpa_ssid *ssid = NULL;
 880         struct wpabuf *extra_ie = NULL;
 881         int ret;
 882         unsigned int max_sched_scan_ssids;
 883         int wildcard = 0;
 884         int need_ssids;
 885
 886         if (!wpa_s->sched_scan_supported)
 887                 return -1;
 888
 889         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 890                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 891         else
 892                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 893         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 894                 return -1;
 895
 896         if (wpa_s->sched_scanning) {
 897                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 898                 return 0;
 899         }
 900
 901         need_ssids = 0;
 902         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 903                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 904                         /* Use wildcard SSID to find this network */
 905                         wildcard = 1;
 906                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 907                            ssid->ssid_len)
 908                         need_ssids++;
 909
 910 #ifdef CONFIG_WPS
 911                 if (!wpas_network_disabled(wpa_s, ssid) &&
 912                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 913                         /*
 914                          * Normal scan is more reliable and faster for WPS
 915                          * operations and since these are for short periods of
 916                          * time, the benefit of trying to use sched_scan would
 917                          * be limited.
 918                          */
 919                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 920                                 "sched_scan for WPS");
 921                         return -1;
 922                 }
 923 #endif /* CONFIG_WPS */
 924         }
 925         if (wildcard)
 926                 need_ssids++;
 927
 928         if (wpa_s->normal_scans < 3 &&
 929             (need_ssids <= wpa_s->max_scan_ssids ||
 930              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 931                 /*
 932                  * When normal scan can speed up operations, use that for the
 933                  * first operations before starting the sched_scan to allow
 934                  * user space sleep more. We do this only if the normal scan
 935                  * has functionality that is suitable for this or if the
 936                  * sched_scan does not have better support for multiple SSIDs.
 937                  */
 938                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 939                         "sched_scan for initial scans (normal_scans=%d)",
 940                         wpa_s->normal_scans);
 941                 return -1;
 942         }
 943
 944         os_memset(&params, 0, sizeof(params));
 945
 946         /* If we can't allocate space for the filters, we just don't filter */
 947         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 948                                         sizeof(struct wpa_driver_scan_filter));
 949
 950         prev_state = wpa_s->wpa_state;
 951         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 952             wpa_s->wpa_state == WPA_INACTIVE)
 953                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 954
 955         if (wpa_s->autoscan_params != NULL) {
 956                 scan_params = wpa_s->autoscan_params;
 957                 goto scan;
 958         }
 959
 960         /* Find the starting point from which to continue scanning */
 961         ssid = wpa_s->conf->ssid;
 962         if (wpa_s->prev_sched_ssid) {
 963                 while (ssid) {
 964                         if (ssid == wpa_s->prev_sched_ssid) {
 965                                 ssid = ssid->next;
 966                                 break;
 967                         }
 968                         ssid = ssid->next;
 969                 }
 970         }
 971
 972         if (!ssid || !wpa_s->prev_sched_ssid) {
 973                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 974
 975                 if (wpa_s->sched_scan_interval == 0)
 976                         wpa_s->sched_scan_interval = 10;
 977                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 978                 wpa_s->first_sched_scan = 1;
 979                 ssid = wpa_s->conf->ssid;
 980                 wpa_s->prev_sched_ssid = ssid;
 981         }
 982
 983         if (wildcard) {
 984                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 985                 params.num_ssids++;
 986         }
 987
 988         while (ssid) {
 989                 if (wpas_network_disabled(wpa_s, ssid))
 990                         goto next;
 991
 992                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 993                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 994                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 995                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 996                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 997                                   ssid->ssid, ssid->ssid_len);
 998                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 999                                 ssid->ssid_len;
1000                         params.num_filter_ssids++;
1001                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1002                 {
1003                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1004                                 "filter for sched_scan - drop filter");
1005                         os_free(params.filter_ssids);
1006                         params.filter_ssids = NULL;
1007                         params.num_filter_ssids = 0;
1008                 }
1009
1010                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1011                         if (params.num_ssids == max_sched_scan_ssids)
1012                                 break; /* only room for broadcast SSID */
1013                         wpa_dbg(wpa_s, MSG_DEBUG,
1014                                 "add to active scan ssid: %s",
1015                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1016                         params.ssids[params.num_ssids].ssid =
1017                                 ssid->ssid;
1018                         params.ssids[params.num_ssids].ssid_len =
1019                                 ssid->ssid_len;
1020                         params.num_ssids++;
1021                         if (params.num_ssids >= max_sched_scan_ssids) {
1022                                 wpa_s->prev_sched_ssid = ssid;
1023                                 do {
1024                                         ssid = ssid->next;
1025                                 } while (ssid &&
1026                                          (wpas_network_disabled(wpa_s, ssid) ||
1027                                           !ssid->scan_ssid));
1028                                 break;
1029                         }
1030                 }
1031
1032         next:
1033                 wpa_s->prev_sched_ssid = ssid;
1034                 ssid = ssid->next;
1035         }
1036
1037         if (params.num_filter_ssids == 0) {
1038                 os_free(params.filter_ssids);
1039                 params.filter_ssids = NULL;
1040         }
1041
1042         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1043         if (extra_ie) {
1044                 params.extra_ies = wpabuf_head(extra_ie);
1045                 params.extra_ies_len = wpabuf_len(extra_ie);
1046         }
1047
1048         scan_params = &params;
1049
1050 scan:
1051         if (ssid || !wpa_s->first_sched_scan) {
1052                 wpa_dbg(wpa_s, MSG_DEBUG,
1053                         "Starting sched scan: interval %d timeout %d",
1054                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1055         } else {
1056                 wpa_dbg(wpa_s, MSG_DEBUG,
1057                         "Starting sched scan: interval %d (no timeout)",
1058                         wpa_s->sched_scan_interval);
1059         }
1060
1061         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1062                                               wpa_s->sched_scan_interval);
1063         wpabuf_free(extra_ie);
1064         os_free(params.filter_ssids);
1065         if (ret) {
1066                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1067                 if (prev_state != wpa_s->wpa_state)
1068                         wpa_supplicant_set_state(wpa_s, prev_state);
1069                 return ret;
1070         }
1071
1072         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1073         if (ssid || !wpa_s->first_sched_scan) {
1074                 wpa_s->sched_scan_timed_out = 0;
1075                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1076                                        wpa_supplicant_sched_scan_timeout,
1077                                        wpa_s, NULL);
1078                 wpa_s->first_sched_scan = 0;
1079                 wpa_s->sched_scan_timeout /= 2;
1080                 wpa_s->sched_scan_interval *= 2;
1081         }
1082
1083         return 0;
1084 }
1085
1086
1087 /**
1088  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1089  * @wpa_s: Pointer to wpa_supplicant data
1090  *
1091  * This function is used to cancel a scan request scheduled with
1092  * wpa_supplicant_req_scan().
1093  */
1094 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1095 {
1096         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1097         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1098 }
1099
1100
1101 /**
1102  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1103  * @wpa_s: Pointer to wpa_supplicant data
1104  *
1105  * This function is used to stop a periodic scheduled scan.
1106  */
1107 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1108 {
1109         if (!wpa_s->sched_scanning)
1110                 return;
1111
1112         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1113         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1114         wpa_supplicant_stop_sched_scan(wpa_s);
1115 }
1116
1117
1118 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1119                                     int scanning)
1120 {
1121         if (wpa_s->scanning != scanning) {
1122                 wpa_s->scanning = scanning;
1123                 wpas_notify_scanning(wpa_s);
1124         }
1125 }
1126
1127
1128 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1129 {
1130         int rate = 0;
1131         const u8 *ie;
1132         int i;
1133
1134         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1135         for (i = 0; ie && i < ie[1]; i++) {
1136                 if ((ie[i + 2] & 0x7f) > rate)
1137                         rate = ie[i + 2] & 0x7f;
1138         }
1139
1140         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1141         for (i = 0; ie && i < ie[1]; i++) {
1142                 if ((ie[i + 2] & 0x7f) > rate)
1143                         rate = ie[i + 2] & 0x7f;
1144         }
1145
1146         return rate;
1147 }
1148
1149
1150 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1151 {
1152         const u8 *end, *pos;
1153
1154         pos = (const u8 *) (res + 1);
1155         end = pos + res->ie_len;
1156
1157         while (pos + 1 < end) {
1158                 if (pos + 2 + pos[1] > end)
1159                         break;
1160                 if (pos[0] == ie)
1161                         return pos;
1162                 pos += 2 + pos[1];
1163         }
1164
1165         return NULL;
1166 }
1167
1168
1169 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1170                                   u32 vendor_type)
1171 {
1172         const u8 *end, *pos;
1173
1174         pos = (const u8 *) (res + 1);
1175         end = pos + res->ie_len;
1176
1177         while (pos + 1 < end) {
1178                 if (pos + 2 + pos[1] > end)
1179                         break;
1180                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1181                     vendor_type == WPA_GET_BE32(&pos[2]))
1182                         return pos;
1183                 pos += 2 + pos[1];
1184         }
1185
1186         return NULL;
1187 }
1188
1189
1190 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1191                                              u32 vendor_type)
1192 {
1193         struct wpabuf *buf;
1194         const u8 *end, *pos;
1195
1196         buf = wpabuf_alloc(res->ie_len);
1197         if (buf == NULL)
1198                 return NULL;
1199
1200         pos = (const u8 *) (res + 1);
1201         end = pos + res->ie_len;
1202
1203         while (pos + 1 < end) {
1204                 if (pos + 2 + pos[1] > end)
1205                         break;
1206                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1207                     vendor_type == WPA_GET_BE32(&pos[2]))
1208                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1209                 pos += 2 + pos[1];
1210         }
1211
1212         if (wpabuf_len(buf) == 0) {
1213                 wpabuf_free(buf);
1214                 buf = NULL;
1215         }
1216
1217         return buf;
1218 }
1219
1220
1221 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1222         const struct wpa_scan_res *res, u32 vendor_type)
1223 {
1224         struct wpabuf *buf;
1225         const u8 *end, *pos;
1226
1227         if (res->beacon_ie_len == 0)
1228                 return NULL;
1229         buf = wpabuf_alloc(res->beacon_ie_len);
1230         if (buf == NULL)
1231                 return NULL;
1232
1233         pos = (const u8 *) (res + 1);
1234         pos += res->ie_len;
1235         end = pos + res->beacon_ie_len;
1236
1237         while (pos + 1 < end) {
1238                 if (pos + 2 + pos[1] > end)
1239                         break;
1240                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1241                     vendor_type == WPA_GET_BE32(&pos[2]))
1242                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1243                 pos += 2 + pos[1];
1244         }
1245
1246         if (wpabuf_len(buf) == 0) {
1247                 wpabuf_free(buf);
1248                 buf = NULL;
1249         }
1250
1251         return buf;
1252 }
1253
1254
1255 /*
1256  * Channels with a great SNR can operate at full rate. What is a great SNR?
1257  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1258  * rule of thumb is that any SNR above 20 is good." This one
1259  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1260  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1261  * conservative value.
1262  */
1263 #define GREAT_SNR 30
1264
1265 /* Compare function for sorting scan results. Return >0 if @b is considered
1266  * better. */
1267 static int wpa_scan_result_compar(const void *a, const void *b)
1268 {
1269 #define IS_5GHZ(n) (n > 4000)
1270 #define MIN(a,b) a < b ? a : b
1271         struct wpa_scan_res **_wa = (void *) a;
1272         struct wpa_scan_res **_wb = (void *) b;
1273         struct wpa_scan_res *wa = *_wa;
1274         struct wpa_scan_res *wb = *_wb;
1275         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1276         int snr_a, snr_b;
1277
1278         /* WPA/WPA2 support preferred */
1279         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1280                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1281         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1282                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1283
1284         if (wpa_b && !wpa_a)
1285                 return 1;
1286         if (!wpa_b && wpa_a)
1287                 return -1;
1288
1289         /* privacy support preferred */
1290         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1291             (wb->caps & IEEE80211_CAP_PRIVACY))
1292                 return 1;
1293         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1294             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1295                 return -1;
1296
1297         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1298             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1299                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1300                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1301         } else {
1302                 /* Not suitable information to calculate SNR, so use level */
1303                 snr_a = wa->level;
1304                 snr_b = wb->level;
1305         }
1306
1307         /* best/max rate preferred if SNR close enough */
1308         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1309             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1310                 maxrate_a = wpa_scan_get_max_rate(wa);
1311                 maxrate_b = wpa_scan_get_max_rate(wb);
1312                 if (maxrate_a != maxrate_b)
1313                         return maxrate_b - maxrate_a;
1314                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1315                         return IS_5GHZ(wa->freq) ? -1 : 1;
1316         }
1317
1318         /* use freq for channel preference */
1319
1320         /* all things being equal, use SNR; if SNRs are
1321          * identical, use quality values since some drivers may only report
1322          * that value and leave the signal level zero */
1323         if (snr_b == snr_a)
1324                 return wb->qual - wa->qual;
1325         return snr_b - snr_a;
1326 #undef MIN
1327 #undef IS_5GHZ
1328 }
1329
1330
1331 #ifdef CONFIG_WPS
1332 /* Compare function for sorting scan results when searching a WPS AP for
1333  * provisioning. Return >0 if @b is considered better. */
1334 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1335 {
1336         struct wpa_scan_res **_wa = (void *) a;
1337         struct wpa_scan_res **_wb = (void *) b;
1338         struct wpa_scan_res *wa = *_wa;
1339         struct wpa_scan_res *wb = *_wb;
1340         int uses_wps_a, uses_wps_b;
1341         struct wpabuf *wps_a, *wps_b;
1342         int res;
1343
1344         /* Optimization - check WPS IE existence before allocated memory and
1345          * doing full reassembly. */
1346         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1347         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1348         if (uses_wps_a && !uses_wps_b)
1349                 return -1;
1350         if (!uses_wps_a && uses_wps_b)
1351                 return 1;
1352
1353         if (uses_wps_a && uses_wps_b) {
1354                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1355                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1356                 res = wps_ap_priority_compar(wps_a, wps_b);
1357                 wpabuf_free(wps_a);
1358                 wpabuf_free(wps_b);
1359                 if (res)
1360                         return res;
1361         }
1362
1363         /*
1364          * Do not use current AP security policy as a sorting criteria during
1365          * WPS provisioning step since the AP may get reconfigured at the
1366          * completion of provisioning.
1367          */
1368
1369         /* all things being equal, use signal level; if signal levels are
1370          * identical, use quality values since some drivers may only report
1371          * that value and leave the signal level zero */
1372         if (wb->level == wa->level)
1373                 return wb->qual - wa->qual;
1374         return wb->level - wa->level;
1375 }
1376 #endif /* CONFIG_WPS */
1377
1378
1379 static void dump_scan_res(struct wpa_scan_results *scan_res)
1380 {
1381 #ifndef CONFIG_NO_STDOUT_DEBUG
1382         size_t i;
1383
1384         if (scan_res->res == NULL || scan_res->num == 0)
1385                 return;
1386
1387         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1388
1389         for (i = 0; i < scan_res->num; i++) {
1390                 struct wpa_scan_res *r = scan_res->res[i];
1391                 u8 *pos;
1392                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1393                     == WPA_SCAN_LEVEL_DBM) {
1394                         int snr = r->level - r->noise;
1395                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1396                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1397                                    MAC2STR(r->bssid), r->freq, r->qual,
1398                                    r->noise, r->level, snr,
1399                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1400                 } else {
1401                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1402                                    "noise=%d level=%d flags=0x%x",
1403                                    MAC2STR(r->bssid), r->freq, r->qual,
1404                                    r->noise, r->level, r->flags);
1405                 }
1406                 pos = (u8 *) (r + 1);
1407                 if (r->ie_len)
1408                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1409                 pos += r->ie_len;
1410                 if (r->beacon_ie_len)
1411                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1412                                     pos, r->beacon_ie_len);
1413         }
1414 #endif /* CONFIG_NO_STDOUT_DEBUG */
1415 }
1416
1417
1418 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1419                                       const u8 *bssid)
1420 {
1421         size_t i;
1422
1423         if (wpa_s->bssid_filter == NULL)
1424                 return 1;
1425
1426         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1427                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1428                               ETH_ALEN) == 0)
1429                         return 1;
1430         }
1431
1432         return 0;
1433 }
1434
1435
1436 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1437                             struct wpa_scan_results *res)
1438 {
1439         size_t i, j;
1440
1441         if (wpa_s->bssid_filter == NULL)
1442                 return;
1443
1444         for (i = 0, j = 0; i < res->num; i++) {
1445                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1446                                                       res->res[i]->bssid)) {
1447                         res->res[j++] = res->res[i];
1448                 } else {
1449                         os_free(res->res[i]);
1450                         res->res[i] = NULL;
1451                 }
1452         }
1453
1454         if (res->num != j) {
1455                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1456                            (int) (res->num - j));
1457                 res->num = j;
1458         }
1459 }
1460
1461
1462 /**
1463  * wpa_supplicant_get_scan_results - Get scan results
1464  * @wpa_s: Pointer to wpa_supplicant data
1465  * @info: Information about what was scanned or %NULL if not available
1466  * @new_scan: Whether a new scan was performed
1467  * Returns: Scan results, %NULL on failure
1468  *
1469  * This function request the current scan results from the driver and updates
1470  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1471  * results with wpa_scan_results_free().
1472  */
1473 struct wpa_scan_results *
1474 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1475                                 struct scan_info *info, int new_scan)
1476 {
1477         struct wpa_scan_results *scan_res;
1478         size_t i;
1479         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1480
1481         scan_res = wpa_drv_get_scan_results2(wpa_s);
1482         if (scan_res == NULL) {
1483                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1484                 return NULL;
1485         }
1486         filter_scan_res(wpa_s, scan_res);
1487
1488 #ifdef CONFIG_WPS
1489         if (wpas_wps_in_progress(wpa_s)) {
1490                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1491                         "provisioning rules");
1492                 compar = wpa_scan_result_wps_compar;
1493         }
1494 #endif /* CONFIG_WPS */
1495
1496         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1497               compar);
1498         dump_scan_res(scan_res);
1499
1500         wpa_bss_update_start(wpa_s);
1501         for (i = 0; i < scan_res->num; i++)
1502                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1503         wpa_bss_update_end(wpa_s, info, new_scan);
1504
1505         return scan_res;
1506 }
1507
1508
1509 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1510 {
1511         struct wpa_scan_results *scan_res;
1512         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1513         if (scan_res == NULL)
1514                 return -1;
1515         wpa_scan_results_free(scan_res);
1516
1517         return 0;
1518 }