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->wps->dev.p2p = 1;
  71                 if (!wps) {
  72                         wps = 1;
  73                         *req_type = WPS_REQ_ENROLLEE_INFO;
  74                 }
  75         }
  76 #endif /* CONFIG_P2P */
  77
  78         return wps;
  79 }
  80 #endif /* CONFIG_WPS */
  81
  82
  83 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  84 {
  85         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  86         int count = 0;
  87         while (ssid) {
  88                 if (!wpas_network_disabled(wpa_s, ssid))
  89                         count++;
  90                 ssid = ssid->next;
  91         }
  92         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
  93             wpa_s->conf->auto_interworking)
  94                 count++;
  95         return count;
  96 }
  97
  98
  99 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 100                                      struct wpa_ssid *ssid)
 101 {
 102         while (ssid) {
 103                 if (!wpas_network_disabled(wpa_s, ssid))
 104                         break;
 105                 ssid = ssid->next;
 106         }
 107
 108         /* ap_scan=2 mode - try to associate with each SSID. */
 109         if (ssid == NULL) {
 110                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 111                         "end of scan list - go back to beginning");
 112                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 113                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 114                 return;
 115         }
 116         if (ssid->next) {
 117                 /* Continue from the next SSID on the next attempt. */
 118                 wpa_s->prev_scan_ssid = ssid;
 119         } else {
 120                 /* Start from the beginning of the SSID list. */
 121                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 122         }
 123         wpa_supplicant_associate(wpa_s, NULL, ssid);
 124 }
 125
 126
 127 static int int_array_len(const int *a)
 128 {
 129         int i;
 130         for (i = 0; a && a[i]; i++)
 131                 ;
 132         return i;
 133 }
 134
 135
 136 static void int_array_concat(int **res, const int *a)
 137 {
 138         int reslen, alen, i;
 139         int *n;
 140
 141         reslen = int_array_len(*res);
 142         alen = int_array_len(a);
 143
 144         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 145         if (n == NULL) {
 146                 os_free(*res);
 147                 *res = NULL;
 148                 return;
 149         }
 150         for (i = 0; i <= alen; i++)
 151                 n[reslen + i] = a[i];
 152         *res = n;
 153 }
 154
 155
 156 static int freq_cmp(const void *a, const void *b)
 157 {
 158         int _a = *(int *) a;
 159         int _b = *(int *) b;
 160
 161         if (_a == 0)
 162                 return 1;
 163         if (_b == 0)
 164                 return -1;
 165         return _a - _b;
 166 }
 167
 168
 169 static void int_array_sort_unique(int *a)
 170 {
 171         int alen;
 172         int i, j;
 173
 174         if (a == NULL)
 175                 return;
 176
 177         alen = int_array_len(a);
 178         qsort(a, alen, sizeof(int), freq_cmp);
 179
 180         i = 0;
 181         j = 1;
 182         while (a[i] && a[j]) {
 183                 if (a[i] == a[j]) {
 184                         j++;
 185                         continue;
 186                 }
 187                 a[++i] = a[j++];
 188         }
 189         if (a[i])
 190                 i++;
 191         a[i] = 0;
 192 }
 193
 194
 195 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 196                                 struct wpa_driver_scan_params *params)
 197 {
 198         int ret;
 199
 200         wpa_supplicant_notify_scanning(wpa_s, 1);
 201
 202         ret = wpa_drv_scan(wpa_s, params);
 203         if (ret) {
 204                 wpa_supplicant_notify_scanning(wpa_s, 0);
 205                 wpas_notify_scan_done(wpa_s, 0);
 206         } else {
 207                 wpa_s->scan_runs++;
 208                 wpa_s->normal_scans++;
 209         }
 210
 211         return ret;
 212 }
 213
 214
 215 static void
 216 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 217 {
 218         struct wpa_supplicant *wpa_s = eloop_ctx;
 219
 220         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 221
 222         if (wpa_supplicant_req_sched_scan(wpa_s))
 223                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 224 }
 225
 226
 227 static void
 228 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 229 {
 230         struct wpa_supplicant *wpa_s = eloop_ctx;
 231
 232         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 233
 234         wpa_s->sched_scan_timed_out = 1;
 235         wpa_supplicant_cancel_sched_scan(wpa_s);
 236 }
 237
 238
 239 static int
 240 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 241                                 struct wpa_driver_scan_params *params,
 242                                 int interval)
 243 {
 244         int ret;
 245 #ifndef ANDROID_P2P
 246         wpa_supplicant_notify_scanning(wpa_s, 1);
 247 #endif
 248         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 249         if (ret)
 250                 wpa_supplicant_notify_scanning(wpa_s, 0);
 251         else {
 252                 wpa_s->sched_scanning = 1;
 253 #ifdef ANDROID_P2P
 254                 wpa_supplicant_notify_scanning(wpa_s, 1);
 255 #endif
 256         }
 257
 258         return ret;
 259 }
 260
 261
 262 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 263 {
 264         int ret;
 265
 266         ret = wpa_drv_stop_sched_scan(wpa_s);
 267         if (ret) {
 268                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 269                 /* TODO: what to do if stopping fails? */
 270                 return -1;
 271         }
 272
 273         return ret;
 274 }
 275
 276
 277 static struct wpa_driver_scan_filter *
 278 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 279 {
 280         struct wpa_driver_scan_filter *ssids;
 281         struct wpa_ssid *ssid;
 282         size_t count;
 283
 284         *num_ssids = 0;
 285         if (!conf->filter_ssids)
 286                 return NULL;
 287
 288         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 289                 if (ssid->ssid && ssid->ssid_len)
 290                         count++;
 291         }
 292         if (count == 0)
 293                 return NULL;
 294         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 295         if (ssids == NULL)
 296                 return NULL;
 297
 298         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 299                 if (!ssid->ssid || !ssid->ssid_len)
 300                         continue;
 301                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 302                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 303                 (*num_ssids)++;
 304         }
 305
 306         return ssids;
 307 }
 308
 309
 310 static void wpa_supplicant_optimize_freqs(
 311         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 312 {
 313 #ifdef CONFIG_P2P
 314         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 315             wpa_s->go_params) {
 316                 /* Optimize provisioning state scan based on GO information */
 317                 if (wpa_s->p2p_in_provisioning < 5 &&
 318                     wpa_s->go_params->freq > 0) {
 319                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 320                                 "preferred frequency %d MHz",
 321                                 wpa_s->go_params->freq);
 322                         params->freqs = os_zalloc(2 * sizeof(int));
 323                         if (params->freqs)
 324                                 params->freqs[0] = wpa_s->go_params->freq;
 325                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 326                            wpa_s->go_params->freq_list[0]) {
 327                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 328                                 "channels");
 329                         int_array_concat(&params->freqs,
 330                                          wpa_s->go_params->freq_list);
 331                         if (params->freqs)
 332                                 int_array_sort_unique(params->freqs);
 333                 }
 334                 wpa_s->p2p_in_provisioning++;
 335         }
 336 #endif /* CONFIG_P2P */
 337
 338 #ifdef CONFIG_WPS
 339         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 340                 /*
 341                  * Optimize post-provisioning scan based on channel used
 342                  * during provisioning.
 343                  */
 344                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 345                         "that was used during provisioning", wpa_s->wps_freq);
 346                 params->freqs = os_zalloc(2 * sizeof(int));
 347                 if (params->freqs)
 348                         params->freqs[0] = wpa_s->wps_freq;
 349                 wpa_s->after_wps--;
 350         }
 351
 352         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 353         {
 354                 /* Optimize provisioning scan based on already known channel */
 355                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 356                         wpa_s->wps_freq);
 357                 params->freqs = os_zalloc(2 * sizeof(int));
 358                 if (params->freqs)
 359                         params->freqs[0] = wpa_s->wps_freq;
 360                 wpa_s->known_wps_freq = 0; /* only do this once */
 361         }
 362 #endif /* CONFIG_WPS */
 363 }
 364
 365
 366 #ifdef CONFIG_INTERWORKING
 367 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 368                                            struct wpabuf *buf)
 369 {
 370         if (wpa_s->conf->interworking == 0)
 371                 return;
 372
 373         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 374         wpabuf_put_u8(buf, 4);
 375         wpabuf_put_u8(buf, 0x00);
 376         wpabuf_put_u8(buf, 0x00);
 377         wpabuf_put_u8(buf, 0x00);
 378         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 379
 380         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 381         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 382                       1 + ETH_ALEN);
 383         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 384         /* No Venue Info */
 385         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 386                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 387 }
 388 #endif /* CONFIG_INTERWORKING */
 389
 390
 391 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 392 {
 393         struct wpabuf *extra_ie = NULL;
 394 #ifdef CONFIG_WPS
 395         int wps = 0;
 396         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 397 #endif /* CONFIG_WPS */
 398
 399 #ifdef CONFIG_INTERWORKING
 400         if (wpa_s->conf->interworking &&
 401             wpabuf_resize(&extra_ie, 100) == 0)
 402                 wpas_add_interworking_elements(wpa_s, extra_ie);
 403 #endif /* CONFIG_INTERWORKING */
 404
 405 #ifdef CONFIG_WPS
 406         wps = wpas_wps_in_use(wpa_s, &req_type);
 407
 408         if (wps) {
 409                 struct wpabuf *wps_ie;
 410                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 411                                                 DEV_PW_DEFAULT,
 412                                                 &wpa_s->wps->dev,
 413                                                 wpa_s->wps->uuid, req_type,
 414                                                 0, NULL);
 415                 if (wps_ie) {
 416                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 417                                 wpabuf_put_buf(extra_ie, wps_ie);
 418                         wpabuf_free(wps_ie);
 419                 }
 420         }
 421
 422 #ifdef CONFIG_P2P
 423         if (wps) {
 424                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 425                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 426                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 427         }
 428 #endif /* CONFIG_P2P */
 429
 430 #endif /* CONFIG_WPS */
 431
 432         return extra_ie;
 433 }
 434
 435
 436 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 437 {
 438         struct wpa_supplicant *wpa_s = eloop_ctx;
 439         struct wpa_ssid *ssid;
 440         int scan_req = 0, ret;
 441         struct wpabuf *extra_ie = NULL;
 442         struct wpa_driver_scan_params params;
 443         struct wpa_driver_scan_params *scan_params;
 444         size_t max_ssids;
 445         enum wpa_states prev_state;
 446
 447         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 448                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 449                 return;
 450         }
 451
 452         if (wpa_s->disconnected && !wpa_s->scan_req) {
 453                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 454                 return;
 455         }
 456 #ifdef ANDROID
 457         if (wpa_s->scanning) {
 458                 /* If we are already in scanning state, we shall ignore this new scan request*/
 459                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - already scanning");
 460                 return;
 461         }
 462 #endif
 463         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 464             !wpa_s->scan_req) {
 465                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 466                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 467                 return;
 468         }
 469
 470         if (wpa_s->conf->ap_scan != 0 &&
 471             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 472                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 473                         "overriding ap_scan configuration");
 474                 wpa_s->conf->ap_scan = 0;
 475                 wpas_notify_ap_scan_changed(wpa_s);
 476         }
 477
 478         if (wpa_s->conf->ap_scan == 0) {
 479                 wpa_supplicant_gen_assoc_event(wpa_s);
 480                 return;
 481         }
 482
 483 #ifdef CONFIG_P2P
 484         if (wpas_p2p_in_progress(wpa_s)) {
 485                 if (wpa_s->sta_scan_pending &&
 486                     wpas_p2p_in_progress(wpa_s) == 2 &&
 487                     wpa_s->global->p2p_cb_on_scan_complete) {
 488                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 489                                 "mode scan during P2P search");
 490                 } else {
 491                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 492                                 "while P2P operation is in progress");
 493                         wpa_s->sta_scan_pending = 1;
 494                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 495                         return;
 496                 }
 497         }
 498 #endif /* CONFIG_P2P */
 499
 500         if (wpa_s->conf->ap_scan == 2)
 501                 max_ssids = 1;
 502         else {
 503                 max_ssids = wpa_s->max_scan_ssids;
 504                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 505                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 506         }
 507
 508         scan_req = wpa_s->scan_req;
 509         wpa_s->scan_req = 0;
 510
 511         os_memset(&params, 0, sizeof(params));
 512
 513         prev_state = wpa_s->wpa_state;
 514         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 515             wpa_s->wpa_state == WPA_INACTIVE)
 516                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 517
 518         /*
 519          * If autoscan has set its own scanning parameters
 520          */
 521         if (wpa_s->autoscan_params != NULL) {
 522                 scan_params = wpa_s->autoscan_params;
 523                 goto scan;
 524         }
 525
 526         if (scan_req != 2 && wpa_s->connect_without_scan) {
 527                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 528                         if (ssid == wpa_s->connect_without_scan)
 529                                 break;
 530                 }
 531                 wpa_s->connect_without_scan = NULL;
 532                 if (ssid) {
 533                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 534                                    "without scan step");
 535                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 536                         return;
 537                 }
 538         }
 539
 540 #ifdef CONFIG_P2P
 541         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 542             wpa_s->go_params) {
 543                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 544                            "P2P group formation");
 545                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 546                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 547                 params.num_ssids = 1;
 548                 goto ssid_list_set;
 549         }
 550 #endif /* CONFIG_P2P */
 551
 552         /* Find the starting point from which to continue scanning */
 553         ssid = wpa_s->conf->ssid;
 554         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 555                 while (ssid) {
 556                         if (ssid == wpa_s->prev_scan_ssid) {
 557                                 ssid = ssid->next;
 558                                 break;
 559                         }
 560                         ssid = ssid->next;
 561                 }
 562         }
 563
 564         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 565                 wpa_s->connect_without_scan = NULL;
 566                 wpa_s->prev_scan_wildcard = 0;
 567                 wpa_supplicant_assoc_try(wpa_s, ssid);
 568                 return;
 569 #ifndef ANDROID
 570         } else if (wpa_s->conf->ap_scan == 2) {
 571                 /*
 572                  * User-initiated scan request in ap_scan == 2; scan with
 573                  * wildcard SSID.
 574                  */
 575                 ssid = NULL;
 576 #endif
 577         } else {
 578                 struct wpa_ssid *start = ssid, *tssid;
 579                 int freqs_set = 0;
 580                 if (ssid == NULL && max_ssids > 1)
 581                         ssid = wpa_s->conf->ssid;
 582                 while (ssid) {
 583                         if (!wpas_network_disabled(wpa_s, ssid) &&
 584                             ssid->scan_ssid) {
 585                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 586                                                   ssid->ssid, ssid->ssid_len);
 587                                 params.ssids[params.num_ssids].ssid =
 588                                         ssid->ssid;
 589                                 params.ssids[params.num_ssids].ssid_len =
 590                                         ssid->ssid_len;
 591                                 params.num_ssids++;
 592                                 if (params.num_ssids + 1 >= max_ssids)
 593                                         break;
 594                         }
 595                         ssid = ssid->next;
 596                         if (ssid == start)
 597                                 break;
 598                         if (ssid == NULL && max_ssids > 1 &&
 599                             start != wpa_s->conf->ssid)
 600                                 ssid = wpa_s->conf->ssid;
 601                 }
 602
 603                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 604                         if (wpas_network_disabled(wpa_s, tssid))
 605                                 continue;
 606                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 607                                 int_array_concat(&params.freqs,
 608                                                  tssid->scan_freq);
 609                         } else {
 610                                 os_free(params.freqs);
 611                                 params.freqs = NULL;
 612                         }
 613                         freqs_set = 1;
 614                 }
 615                 int_array_sort_unique(params.freqs);
 616         }
 617
 618         if (ssid && max_ssids == 1) {
 619                 /*
 620                  * If the driver is limited to 1 SSID at a time interleave
 621                  * wildcard SSID scans with specific SSID scans to avoid
 622                  * waiting a long time for a wildcard scan.
 623                  */
 624                 if (!wpa_s->prev_scan_wildcard) {
 625                         params.ssids[0].ssid = NULL;
 626                         params.ssids[0].ssid_len = 0;
 627                         wpa_s->prev_scan_wildcard = 1;
 628                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 629                                 "wildcard SSID (Interleave with specific)");
 630                 } else {
 631                         wpa_s->prev_scan_ssid = ssid;
 632                         wpa_s->prev_scan_wildcard = 0;
 633                         wpa_dbg(wpa_s, MSG_DEBUG,
 634                                 "Starting AP scan for specific SSID: %s",
 635                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 636                 }
 637         } else if (ssid) {
 638                 /* max_ssids > 1 */
 639
 640                 wpa_s->prev_scan_ssid = ssid;
 641                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 642                         "the scan request");
 643                 params.num_ssids++;
 644         } else {
 645                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 646                 params.num_ssids++;
 647                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 648                         "SSID");
 649         }
 650 #ifdef CONFIG_P2P
 651 ssid_list_set:
 652 #endif /* CONFIG_P2P */
 653
 654         wpa_supplicant_optimize_freqs(wpa_s, &params);
 655         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 656
 657 #ifdef CONFIG_HS20
 658         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 659                 wpas_hs20_add_indication(extra_ie);
 660 #endif /* CONFIG_HS20 */
 661
 662         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 663                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 664                         "generated frequency list");
 665                 params.freqs = wpa_s->next_scan_freqs;
 666         } else
 667                 os_free(wpa_s->next_scan_freqs);
 668         wpa_s->next_scan_freqs = NULL;
 669
 670         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 671                 wpa_s->conf, &params.num_filter_ssids);
 672         if (extra_ie) {
 673                 params.extra_ies = wpabuf_head(extra_ie);
 674                 params.extra_ies_len = wpabuf_len(extra_ie);
 675         }
 676
 677 #ifdef CONFIG_P2P
 678         if (wpa_s->p2p_in_provisioning ||
 679             (wpa_s->show_group_started && wpa_s->go_params)) {
 680                 /*
 681                  * The interface may not yet be in P2P mode, so we have to
 682                  * explicitly request P2P probe to disable CCK rates.
 683                  */
 684                 params.p2p_probe = 1;
 685         }
 686 #endif /* CONFIG_P2P */
 687
 688         scan_params = &params;
 689
 690 scan:
 691         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 692
 693         wpabuf_free(extra_ie);
 694         os_free(params.freqs);
 695         os_free(params.filter_ssids);
 696
 697         if (ret) {
 698                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 699 #ifdef ANDROID_P2P
 700                 /* Restore back the wpa_s->scan_req if we failed the scan because of any reason */
 701                 wpa_msg(wpa_s, MSG_DEBUG, "Restoring back the wpa_s->scan_req "
 702                         "to the original value %d", scan_req);
 703                 wpa_s->scan_req = scan_req;
 704 #endif
 705                 if (prev_state != wpa_s->wpa_state)
 706                         wpa_supplicant_set_state(wpa_s, prev_state);
 707                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 708         }
 709 }
 710
 711
 712 /**
 713  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 714  * @wpa_s: Pointer to wpa_supplicant data
 715  * @sec: Number of seconds after which to scan
 716  * @usec: Number of microseconds after which to scan
 717  *
 718  * This function is used to schedule a scan for neighboring access points after
 719  * the specified time.
 720  */
 721 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 722 {
 723 #ifndef ANDROID
 724         /* If there's at least one network that should be specifically scanned
 725          * then don't cancel the scan and reschedule.  Some drivers do
 726          * background scanning which generates frequent scan results, and that
 727          * causes the specific SSID scan to get continually pushed back and
 728          * never happen, which causes hidden APs to never get probe-scanned.
 729          */
 730         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 731             wpa_s->conf->ap_scan == 1) {
 732                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 733
 734                 while (ssid) {
 735                         if (!wpas_network_disabled(wpa_s, ssid) &&
 736                             ssid->scan_ssid)
 737                                 break;
 738                         ssid = ssid->next;
 739                 }
 740                 if (ssid) {
 741                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 742                                 "ensure that specific SSID scans occur");
 743                         return;
 744                 }
 745         }
 746 #endif
 747         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 748                 sec, usec);
 749         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 750         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 751 }
 752
 753
 754 /**
 755  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 756  * @wpa_s: Pointer to wpa_supplicant data
 757  * @sec: Number of seconds after which to scan
 758  * @usec: Number of microseconds after which to scan
 759  *
 760  * This function is used to schedule periodic scans for neighboring
 761  * access points after the specified time.
 762  */
 763 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 764                                       int sec, int usec)
 765 {
 766         if (!wpa_s->sched_scan_supported)
 767                 return -1;
 768
 769         eloop_register_timeout(sec, usec,
 770                                wpa_supplicant_delayed_sched_scan_timeout,
 771                                wpa_s, NULL);
 772
 773         return 0;
 774 }
 775
 776
 777 /**
 778  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 779  * @wpa_s: Pointer to wpa_supplicant data
 780  *
 781  * This function is used to schedule periodic scans for neighboring
 782  * access points repeating the scan continuously.
 783  */
 784 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 785 {
 786         struct wpa_driver_scan_params params;
 787         struct wpa_driver_scan_params *scan_params;
 788         enum wpa_states prev_state;
 789         struct wpa_ssid *ssid = NULL;
 790         struct wpabuf *extra_ie = NULL;
 791         int ret;
 792         unsigned int max_sched_scan_ssids;
 793         int wildcard = 0;
 794         int need_ssids;
 795
 796         if (!wpa_s->sched_scan_supported)
 797                 return -1;
 798
 799         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 800                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 801         else
 802                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 803         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 804                 return -1;
 805
 806         if (wpa_s->sched_scanning) {
 807                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 808                 return 0;
 809         }
 810
 811         need_ssids = 0;
 812         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 813                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 814                         /* Use wildcard SSID to find this network */
 815                         wildcard = 1;
 816                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 817                            ssid->ssid_len)
 818                         need_ssids++;
 819
 820 #ifdef CONFIG_WPS
 821                 if (!wpas_network_disabled(wpa_s, ssid) &&
 822                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 823                         /*
 824                          * Normal scan is more reliable and faster for WPS
 825                          * operations and since these are for short periods of
 826                          * time, the benefit of trying to use sched_scan would
 827                          * be limited.
 828                          */
 829                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 830                                 "sched_scan for WPS");
 831                         return -1;
 832                 }
 833 #endif /* CONFIG_WPS */
 834         }
 835         if (wildcard)
 836                 need_ssids++;
 837
 838         if (wpa_s->normal_scans < 3 &&
 839             (need_ssids <= wpa_s->max_scan_ssids ||
 840              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 841                 /*
 842                  * When normal scan can speed up operations, use that for the
 843                  * first operations before starting the sched_scan to allow
 844                  * user space sleep more. We do this only if the normal scan
 845                  * has functionality that is suitable for this or if the
 846                  * sched_scan does not have better support for multiple SSIDs.
 847                  */
 848                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 849                         "sched_scan for initial scans (normal_scans=%d)",
 850                         wpa_s->normal_scans);
 851                 return -1;
 852         }
 853
 854         os_memset(&params, 0, sizeof(params));
 855
 856         /* If we can't allocate space for the filters, we just don't filter */
 857         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 858                                         sizeof(struct wpa_driver_scan_filter));
 859
 860         prev_state = wpa_s->wpa_state;
 861 #ifndef ANDROID_P2P
 862         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 863             wpa_s->wpa_state == WPA_INACTIVE)
 864                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 865 #endif
 866
 867         if (wpa_s->autoscan_params != NULL) {
 868                 scan_params = wpa_s->autoscan_params;
 869                 goto scan;
 870         }
 871
 872         /* Find the starting point from which to continue scanning */
 873         ssid = wpa_s->conf->ssid;
 874         if (wpa_s->prev_sched_ssid) {
 875                 while (ssid) {
 876                         if (ssid == wpa_s->prev_sched_ssid) {
 877                                 ssid = ssid->next;
 878                                 break;
 879                         }
 880                         ssid = ssid->next;
 881                 }
 882         }
 883
 884         if (!ssid || !wpa_s->prev_sched_ssid) {
 885                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 886
 887                 if (wpa_s->sched_scan_interval == 0)
 888                         wpa_s->sched_scan_interval = 10;
 889                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 890                 wpa_s->first_sched_scan = 1;
 891                 ssid = wpa_s->conf->ssid;
 892                 wpa_s->prev_sched_ssid = ssid;
 893         }
 894
 895         if (wildcard) {
 896                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 897                 params.num_ssids++;
 898         }
 899
 900         while (ssid) {
 901                 if (wpas_network_disabled(wpa_s, ssid))
 902                         goto next;
 903
 904                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 905                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 906                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 907                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 908                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 909                                   ssid->ssid, ssid->ssid_len);
 910                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 911                                 ssid->ssid_len;
 912                         params.num_filter_ssids++;
 913                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 914                 {
 915                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 916                                 "filter for sched_scan - drop filter");
 917                         os_free(params.filter_ssids);
 918                         params.filter_ssids = NULL;
 919                         params.num_filter_ssids = 0;
 920                 }
 921
 922                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 923                         if (params.num_ssids == max_sched_scan_ssids)
 924                                 break; /* only room for broadcast SSID */
 925                         wpa_dbg(wpa_s, MSG_DEBUG,
 926                                 "add to active scan ssid: %s",
 927                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 928                         params.ssids[params.num_ssids].ssid =
 929                                 ssid->ssid;
 930                         params.ssids[params.num_ssids].ssid_len =
 931                                 ssid->ssid_len;
 932                         params.num_ssids++;
 933                         if (params.num_ssids >= max_sched_scan_ssids) {
 934                                 wpa_s->prev_sched_ssid = ssid;
 935                                 do {
 936                                         ssid = ssid->next;
 937                                 } while (ssid &&
 938                                          (wpas_network_disabled(wpa_s, ssid) ||
 939                                           !ssid->scan_ssid));
 940                                 break;
 941                         }
 942                 }
 943
 944         next:
 945                 wpa_s->prev_sched_ssid = ssid;
 946                 ssid = ssid->next;
 947         }
 948
 949         if (params.num_filter_ssids == 0) {
 950                 os_free(params.filter_ssids);
 951                 params.filter_ssids = NULL;
 952         }
 953
 954         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 955         if (extra_ie) {
 956                 params.extra_ies = wpabuf_head(extra_ie);
 957                 params.extra_ies_len = wpabuf_len(extra_ie);
 958         }
 959
 960         scan_params = &params;
 961
 962 scan:
 963         if (ssid || !wpa_s->first_sched_scan) {
 964                 wpa_dbg(wpa_s, MSG_DEBUG,
 965                         "Starting sched scan: interval %d timeout %d",
 966                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 967         } else {
 968                 wpa_dbg(wpa_s, MSG_DEBUG,
 969                         "Starting sched scan: interval %d (no timeout)",
 970                         wpa_s->sched_scan_interval);
 971         }
 972
 973         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 974                                               wpa_s->sched_scan_interval);
 975         wpabuf_free(extra_ie);
 976         os_free(params.filter_ssids);
 977         if (ret) {
 978                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 979                 if (prev_state != wpa_s->wpa_state)
 980                         wpa_supplicant_set_state(wpa_s, prev_state);
 981                 return ret;
 982         }
 983
 984         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 985         if (ssid || !wpa_s->first_sched_scan) {
 986                 wpa_s->sched_scan_timed_out = 0;
 987                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 988                                        wpa_supplicant_sched_scan_timeout,
 989                                        wpa_s, NULL);
 990                 wpa_s->first_sched_scan = 0;
 991                 wpa_s->sched_scan_timeout /= 2;
 992                 wpa_s->sched_scan_interval *= 2;
 993         }
 994
 995         return 0;
 996 }
 997
 998
 999 /**
1000  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1001  * @wpa_s: Pointer to wpa_supplicant data
1002  *
1003  * This function is used to cancel a scan request scheduled with
1004  * wpa_supplicant_req_scan().
1005  */
1006 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1007 {
1008         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1009         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1010 #ifdef ANDROID
1011         wpa_supplicant_notify_scanning(wpa_s, 0);
1012 #endif
1013 }
1014
1015
1016 /**
1017  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1018  * @wpa_s: Pointer to wpa_supplicant data
1019  *
1020  * This function is used to stop a periodic scheduled scan.
1021  */
1022 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1023 {
1024         if (!wpa_s->sched_scanning)
1025                 return;
1026
1027         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1028         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1029         wpa_supplicant_stop_sched_scan(wpa_s);
1030 }
1031
1032
1033 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1034                                     int scanning)
1035 {
1036         if (wpa_s->scanning != scanning) {
1037 #ifdef ANDROID_P2P
1038                 if(!wpa_s->sched_scanning)
1039                         wpa_s->scanning = scanning;
1040 #else
1041                 wpa_s->scanning = scanning;
1042 #endif
1043                 wpas_notify_scanning(wpa_s);
1044         }
1045 }
1046
1047
1048 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1049 {
1050         int rate = 0;
1051         const u8 *ie;
1052         int i;
1053
1054         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1055         for (i = 0; ie && i < ie[1]; i++) {
1056                 if ((ie[i + 2] & 0x7f) > rate)
1057                         rate = ie[i + 2] & 0x7f;
1058         }
1059
1060         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1061         for (i = 0; ie && i < ie[1]; i++) {
1062                 if ((ie[i + 2] & 0x7f) > rate)
1063                         rate = ie[i + 2] & 0x7f;
1064         }
1065
1066         return rate;
1067 }
1068
1069
1070 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1071 {
1072         const u8 *end, *pos;
1073
1074         pos = (const u8 *) (res + 1);
1075         end = pos + res->ie_len;
1076
1077         while (pos + 1 < end) {
1078                 if (pos + 2 + pos[1] > end)
1079                         break;
1080                 if (pos[0] == ie)
1081                         return pos;
1082                 pos += 2 + pos[1];
1083         }
1084
1085         return NULL;
1086 }
1087
1088
1089 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1090                                   u32 vendor_type)
1091 {
1092         const u8 *end, *pos;
1093
1094         pos = (const u8 *) (res + 1);
1095         end = pos + res->ie_len;
1096
1097         while (pos + 1 < end) {
1098                 if (pos + 2 + pos[1] > end)
1099                         break;
1100                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1101                     vendor_type == WPA_GET_BE32(&pos[2]))
1102                         return pos;
1103                 pos += 2 + pos[1];
1104         }
1105
1106         return NULL;
1107 }
1108
1109
1110 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1111                                              u32 vendor_type)
1112 {
1113         struct wpabuf *buf;
1114         const u8 *end, *pos;
1115
1116         buf = wpabuf_alloc(res->ie_len);
1117         if (buf == NULL)
1118                 return NULL;
1119
1120         pos = (const u8 *) (res + 1);
1121         end = pos + res->ie_len;
1122
1123         while (pos + 1 < end) {
1124                 if (pos + 2 + pos[1] > end)
1125                         break;
1126                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1127                     vendor_type == WPA_GET_BE32(&pos[2]))
1128                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1129                 pos += 2 + pos[1];
1130         }
1131
1132         if (wpabuf_len(buf) == 0) {
1133                 wpabuf_free(buf);
1134                 buf = NULL;
1135         }
1136
1137         return buf;
1138 }
1139
1140
1141 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1142         const struct wpa_scan_res *res, u32 vendor_type)
1143 {
1144         struct wpabuf *buf;
1145         const u8 *end, *pos;
1146
1147         if (res->beacon_ie_len == 0)
1148                 return NULL;
1149         buf = wpabuf_alloc(res->beacon_ie_len);
1150         if (buf == NULL)
1151                 return NULL;
1152
1153         pos = (const u8 *) (res + 1);
1154         pos += res->ie_len;
1155         end = pos + res->beacon_ie_len;
1156
1157         while (pos + 1 < end) {
1158                 if (pos + 2 + pos[1] > end)
1159                         break;
1160                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1161                     vendor_type == WPA_GET_BE32(&pos[2]))
1162                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1163                 pos += 2 + pos[1];
1164         }
1165
1166         if (wpabuf_len(buf) == 0) {
1167                 wpabuf_free(buf);
1168                 buf = NULL;
1169         }
1170
1171         return buf;
1172 }
1173
1174
1175 /*
1176  * Channels with a great SNR can operate at full rate. What is a great SNR?
1177  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1178  * rule of thumb is that any SNR above 20 is good." This one
1179  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1180  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1181  * conservative value.
1182  */
1183 #define GREAT_SNR 30
1184
1185 /* Compare function for sorting scan results. Return >0 if @b is considered
1186  * better. */
1187 static int wpa_scan_result_compar(const void *a, const void *b)
1188 {
1189 #define IS_5GHZ(n) (n > 4000)
1190 #define MIN(a,b) a < b ? a : b
1191         struct wpa_scan_res **_wa = (void *) a;
1192         struct wpa_scan_res **_wb = (void *) b;
1193         struct wpa_scan_res *wa = *_wa;
1194         struct wpa_scan_res *wb = *_wb;
1195         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1196         int snr_a, snr_b;
1197
1198         /* WPA/WPA2 support preferred */
1199         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1200                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1201         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1202                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1203
1204         if (wpa_b && !wpa_a)
1205                 return 1;
1206         if (!wpa_b && wpa_a)
1207                 return -1;
1208
1209         /* privacy support preferred */
1210         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1211             (wb->caps & IEEE80211_CAP_PRIVACY))
1212                 return 1;
1213         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1214             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1215                 return -1;
1216
1217         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1218             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1219                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1220                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1221         } else {
1222                 /* Not suitable information to calculate SNR, so use level */
1223                 snr_a = wa->level;
1224                 snr_b = wb->level;
1225         }
1226
1227         /* best/max rate preferred if SNR close enough */
1228         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1229             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1230                 maxrate_a = wpa_scan_get_max_rate(wa);
1231                 maxrate_b = wpa_scan_get_max_rate(wb);
1232                 if (maxrate_a != maxrate_b)
1233                         return maxrate_b - maxrate_a;
1234                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1235                         return IS_5GHZ(wa->freq) ? -1 : 1;
1236         }
1237
1238         /* use freq for channel preference */
1239
1240         /* all things being equal, use SNR; if SNRs are
1241          * identical, use quality values since some drivers may only report
1242          * that value and leave the signal level zero */
1243         if (snr_b == snr_a)
1244                 return wb->qual - wa->qual;
1245         return snr_b - snr_a;
1246 #undef MIN
1247 #undef IS_5GHZ
1248 }
1249
1250
1251 #ifdef CONFIG_WPS
1252 /* Compare function for sorting scan results when searching a WPS AP for
1253  * provisioning. Return >0 if @b is considered better. */
1254 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1255 {
1256         struct wpa_scan_res **_wa = (void *) a;
1257         struct wpa_scan_res **_wb = (void *) b;
1258         struct wpa_scan_res *wa = *_wa;
1259         struct wpa_scan_res *wb = *_wb;
1260         int uses_wps_a, uses_wps_b;
1261         struct wpabuf *wps_a, *wps_b;
1262         int res;
1263
1264         /* Optimization - check WPS IE existence before allocated memory and
1265          * doing full reassembly. */
1266         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1267         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1268         if (uses_wps_a && !uses_wps_b)
1269                 return -1;
1270         if (!uses_wps_a && uses_wps_b)
1271                 return 1;
1272
1273         if (uses_wps_a && uses_wps_b) {
1274                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1275                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1276                 res = wps_ap_priority_compar(wps_a, wps_b);
1277                 wpabuf_free(wps_a);
1278                 wpabuf_free(wps_b);
1279                 if (res)
1280                         return res;
1281         }
1282
1283         /*
1284          * Do not use current AP security policy as a sorting criteria during
1285          * WPS provisioning step since the AP may get reconfigured at the
1286          * completion of provisioning.
1287          */
1288
1289         /* all things being equal, use signal level; if signal levels are
1290          * identical, use quality values since some drivers may only report
1291          * that value and leave the signal level zero */
1292         if (wb->level == wa->level)
1293                 return wb->qual - wa->qual;
1294         return wb->level - wa->level;
1295 }
1296 #endif /* CONFIG_WPS */
1297
1298
1299 static void dump_scan_res(struct wpa_scan_results *scan_res)
1300 {
1301 #ifndef CONFIG_NO_STDOUT_DEBUG
1302         size_t i;
1303
1304         if (scan_res->res == NULL || scan_res->num == 0)
1305                 return;
1306
1307         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1308
1309         for (i = 0; i < scan_res->num; i++) {
1310                 struct wpa_scan_res *r = scan_res->res[i];
1311                 u8 *pos;
1312                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1313                     == WPA_SCAN_LEVEL_DBM) {
1314                         int snr = r->level - r->noise;
1315                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1316                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1317                                    MAC2STR(r->bssid), r->freq, r->qual,
1318                                    r->noise, r->level, snr,
1319                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1320                 } else {
1321                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1322                                    "noise=%d level=%d flags=0x%x",
1323                                    MAC2STR(r->bssid), r->freq, r->qual,
1324                                    r->noise, r->level, r->flags);
1325                 }
1326                 pos = (u8 *) (r + 1);
1327                 if (r->ie_len)
1328                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1329                 pos += r->ie_len;
1330                 if (r->beacon_ie_len)
1331                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1332                                     pos, r->beacon_ie_len);
1333         }
1334 #endif /* CONFIG_NO_STDOUT_DEBUG */
1335 }
1336
1337
1338 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1339                                       const u8 *bssid)
1340 {
1341         size_t i;
1342
1343         if (wpa_s->bssid_filter == NULL)
1344                 return 1;
1345
1346         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1347                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1348                               ETH_ALEN) == 0)
1349                         return 1;
1350         }
1351
1352         return 0;
1353 }
1354
1355
1356 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1357                             struct wpa_scan_results *res)
1358 {
1359         size_t i, j;
1360
1361         if (wpa_s->bssid_filter == NULL)
1362                 return;
1363
1364         for (i = 0, j = 0; i < res->num; i++) {
1365                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1366                                                       res->res[i]->bssid)) {
1367                         res->res[j++] = res->res[i];
1368                 } else {
1369                         os_free(res->res[i]);
1370                         res->res[i] = NULL;
1371                 }
1372         }
1373
1374         if (res->num != j) {
1375                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1376                            (int) (res->num - j));
1377                 res->num = j;
1378         }
1379 }
1380
1381
1382 /**
1383  * wpa_supplicant_get_scan_results - Get scan results
1384  * @wpa_s: Pointer to wpa_supplicant data
1385  * @info: Information about what was scanned or %NULL if not available
1386  * @new_scan: Whether a new scan was performed
1387  * Returns: Scan results, %NULL on failure
1388  *
1389  * This function request the current scan results from the driver and updates
1390  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1391  * results with wpa_scan_results_free().
1392  */
1393 struct wpa_scan_results *
1394 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1395                                 struct scan_info *info, int new_scan)
1396 {
1397         struct wpa_scan_results *scan_res;
1398         size_t i;
1399         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1400
1401         scan_res = wpa_drv_get_scan_results2(wpa_s);
1402         if (scan_res == NULL) {
1403                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1404                 return NULL;
1405         }
1406         filter_scan_res(wpa_s, scan_res);
1407
1408 #ifdef CONFIG_WPS
1409         if (wpas_wps_in_progress(wpa_s)) {
1410                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1411                         "provisioning rules");
1412                 compar = wpa_scan_result_wps_compar;
1413         }
1414 #endif /* CONFIG_WPS */
1415
1416         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1417               compar);
1418         dump_scan_res(scan_res);
1419
1420         wpa_bss_update_start(wpa_s);
1421         for (i = 0; i < scan_res->num; i++)
1422                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1423         wpa_bss_update_end(wpa_s, info, new_scan);
1424
1425         return scan_res;
1426 }
1427
1428
1429 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1430 {
1431         struct wpa_scan_results *scan_res;
1432         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1433         if (scan_res == NULL)
1434                 return -1;
1435         wpa_scan_results_free(scan_res);
1436
1437         return 0;
1438 }